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Intravenous and Intraperitoneal Pharmacokinetics of Dalbavancin in Peritoneal Dialysis Patients [Pharmacology]

Dalbavancin offers a possible treatment option for infectious peritonitis associated with peritoneal dialysis (PD) due to its coverage of Gram-positive bacteria and pharmacokinetic properties. We aimed to evaluate the clinical pharmacokinetics (PK) and pharmacodynamics of dalbavancin in a prospective, randomized, open-label, crossover PK study of adult patients with end-stage renal disease ESRD who were receiving PD. Sampling occurred prior to a single 30-min infusion of dalbavancin at 1,500 mg and at 1, 2, 3, 4, and 6 h and 7 and 14 days postadministration. Concentration-time data were analyzed via noncompartmental analysis. Pharmacodynamic parameters against common infectious peritonitis-causing pathogens were evaluated. Ten patients were enrolled. Patients were a median of 55 years old and had a median weight of 78.2 kg, 50% were female, and 70% were Caucasian. The terminal plasma half-life of dalbavancin was 181.4 ± 35.5 h. The day 0 to day 14 dalbavancin mean area under the curve (AUC) was 40,573.2 ± 9,800.3 mg·h/liter. The terminal-phase half-life of dalbavancin within the peritoneal fluid was 4.309 x 108 ± 1.140 x 109 h. The day 0 to day 14 dalbavancin mean peritoneal fluid AUC was 2,125.0 ± 1,794.3 mg·h/liter. The target plasma AUC/MIC was attained with the intravenous dose in all 10 patients for all Staphylococcus and Streptococcus species at the recommended MIC breakpoints. The intraperitoneal arm of the study was stopped early, because the first 3 patients experienced moderate to severe pain and bloating within 1 h following the administration of dalbavancin. Dalbavancin at 1,500 mg administered intravenously can be utilized without dose adjustment in peritoneal dialysis patients and will likely achieve the necessary peritoneal fluid concentrations to treat peritonitis caused by typical Gram-positive pathogens.




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Impact of Daptomycin Dose Exposure Alone or in Combination with {beta}-Lactams or Rifampin against Vancomycin-Resistant Enterococci in an In Vitro Biofilm Model [Susceptibility]

Enterococcus faecium strains are commonly resistant to vancomycin and β-lactams. In addition, E. faecium often causes biofilm-associated infections and these infections are difficult to treat. In this context, we investigated the activity of dosing regimens using daptomycin (DAP) (8, 10, 12, and 14 mg/kg of body weight/day) alone and in combination with ceftaroline (CPT), ampicillin (AMP), ertapenem (ERT), and rifampin (RIF) against 2 clinical strains of biofilm-producing vancomycin-resistant Enterococcus faecium (VREfm), namely, strains S447 and HOU503, in an in vitro biofilm model. HOU503 harbors common LiaS and LiaR substitutions, whereas S447 lacks mutations associated with the LiaFSR pathway. MIC results demonstrated that both strains were susceptible to DAP and resistant to CPT, AMP, ERT, and RIF. The 168-h pharmacokinetic/pharmacodynamic (PK/PD) CDC biofilm reactor models (simulating human antibiotic exposures) were used with titanium and polyurethane coupons to evaluate the efficacy of antibiotic combinations. DAP 12 and 14 achieved bactericidal activity against S447 but lacked such effect against HOU503. Addition of ERT and RIF enhanced DAP activity, allowing DAP 8 and 10 plus ERT or RIF to produce bactericidal activity against both strains at 168 h. While DAP 8 and 10 plus CPT improved killing, they did not reach bactericidal reduction against S447. Combination of AMP, CPT, ERT, or RIF resulted in enhanced and bactericidal activity for DAP against HOU503 at 168 h. Our data provide further support for the use of combinations of DAP with AMP, ERT, CPT, and RIF in infections caused by biofilm producing VREfm. Further research involving DAP combinations against biofilm-producing enterococci is warranted.




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Comparison of Commensal and Clinical Isolates for Diversity of Plasmids in Escherichia coli and Klebsiella pneumoniae [Epidemiology and Surveillance]

In this study, the plasmid content of clinical and commensal strains was analyzed and compared. The replicon profile was similar in both populations, except for L, M, A/C, and N (detected only in clinical strains) and HI1 (only in commensal strains). Although I1 and F were the most frequent replicons, only IncI1, sequence type 12 (ST12) was associated with blaCMY-2 in both populations. In contrast, the widespread resistant IncF plasmids were not linked to a single epidemic plasmid.




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Novel Insights into Plasmodium vivax Therapeutic Failure: CYP2D6 Activity and Time of Exposure to Malaria Modulate the Risk of Recurrence [Epidemiology and Surveillance]

Plasmodium vivax relapse is one of the major causes of sustained global malaria transmission. Primaquine (PQ) is the only commercial drug available to prevent relapses, and its efficacy is dependent on metabolic activation by cytochrome P450 2D6 (CYP2D6). Impaired CYP2D6 function, caused by allelic polymorphisms, leads to the therapeutic failure of PQ as a radical cure for P. vivax malaria. Here, we hypothesized that the host immune response to malaria parasites modulates susceptibility to P. vivax recurrences in association with CYP2D6 activity. We performed a 10-year retrospective study by genotyping CYP2D6 polymorphisms in 261 malaria-exposed individuals from the Brazilian Amazon. The immune responses against a panel of P. vivax blood-stage antigens were evaluated by serological assays. We confirmed our previous findings, which indicated an association between impaired CYP2D6 activity and a higher risk of multiple episodes of P. vivax recurrence (risk ratio, 1.75; 95% confidence interval [CI], 1.2 to 2.6; P = 0.0035). An important finding was a reduction of 3% in the risk of recurrence (risk ratio, 0.97; 95% CI, 0.96 to 0.98; P < 0.0001) per year of malaria exposure, which was observed for individuals with both reduced and normal CYP2D6 activity. Accordingly, subjects with long-term malaria exposure and persistent antibody responses to various antigens showed fewer episodes of malaria recurrence. Our findings have direct implications for malaria control, since it was shown that nonimmune individuals who do not respond adequately to treatment due to reduced CYP2D6 activity may present a significant challenge for sustainable progress toward P. vivax malaria elimination.




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Synthesis and Biological Activity of Novel Zinc-Itraconazole Complexes in Protozoan Parasites and Sporothrix spp. [Susceptibility]

The new complexes Zn(ITZ)2Cl2 (1) and Zn(ITZ)2(OH)2 (2) were synthetized by a reaction of itraconazole with their respective zinc salts under reflux. These Zn-ITZ complexes were characterized by elemental analyses, molar conductivity, mass spectrometry, 1H and 13C{1H} nuclear magnetic resonance, and UV-vis and infrared spectroscopies. The antiparasitic and antifungal activity of Zn-ITZ complexes was evaluated against three protozoans of medical importance, namely, Leishmania amazonensis, Trypanosoma cruzi, and Toxoplasma gondii, and two fungi, namely, Sporothrix brasiliensis and Sporothrix schenckii. The Zn-ITZ complexes exhibited a broad spectrum of action, with antiparasitic and antifungal activity in low concentrations. The strategy of combining zinc with ITZ was efficient to enhance ITZ activity since Zn-ITZ-complexes were more active than the azole alone. This study opens perspectives for future applications of these Zn-ITZ complexes in the treatment of parasitic diseases and sporotrichosis.




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Early Bactericidal Activity Trial of Nitazoxanide for Pulmonary Tuberculosis [Clinical Therapeutics]

This study was conducted in treatment-naive adults with drug-susceptible pulmonary tuberculosis in Port-au-Prince, Haiti, to assess the safety, bactericidal activity, and pharmacokinetics of nitazoxanide (NTZ). This was a prospective phase II clinical trial in 30 adults with pulmonary tuberculosis. Twenty participants received 1 g of NTZ orally twice daily for 14 days. A control group of 10 participants received standard therapy over 14 days. The primary outcome was the change in time to culture positivity (TTP) in an automated liquid culture system. The most common adverse events seen in the NTZ group were gastrointestinal complaints and headache. The mean change in TTP in sputum over 14 days in the NTZ group was 3.2 h ± 22.6 h and was not statistically significant (P = 0.56). The mean change in TTP in the standard therapy group was significantly increased, at 134 h ± 45.2 h (P < 0.0001). The mean NTZ MIC for Mycobacterium tuberculosis isolates was 12.3 μg/ml; the mean NTZ maximum concentration (Cmax) in plasma was 10.2 μg/ml. Negligible NTZ levels were measured in sputum. At the doses used, NTZ did not show bactericidal activity against M. tuberculosis. Plasma concentrations of NTZ were below the MIC, and its negligible accumulation in pulmonary sites may explain the lack of bactericidal activity. (This study has been registered at ClinicalTrials.gov under identifier NCT02684240.)




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Activity of Cefiderocol and Comparators against Isolates from Cancer Patients [Susceptibility]

Cefiderocol inhibited 97.5% of 478 Gram-negative isolates from cancer patients at ≤4 mg/liter. It had potent activity against extended-spectrum β-lactamase-positive Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae (CRE), and nonfermenting Gram-negative bacilli, including Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter species isolates. Amikacin, ceftazidime-avibactam, and meropenem had appreciable activity against non-CRE Enterobacteriaceae. No comparators were active against multidrug-resistant P. aeruginosa isolates. Only trimethoprim-sulfamethoxazole had appreciable activity against S. maltophilia isolates. Overall, cefiderocol was associated with the lowest level of resistance.




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Abacavir Exposure in Children Cotreated for Tuberculosis with Rifampin and Superboosted Lopinavir-Ritonavir [Pharmacology]

In children requiring lopinavir coformulated with ritonavir in a 4:1 ratio (lopinavir-ritonavir-4:1) and rifampin, adding ritonavir to achieve a 4:4 ratio with lopinavir (LPV/r-4:4) overcomes the drug-drug interaction. Possible drug-drug interactions within this regimen may affect abacavir concentrations, but this has never been studied. Children weighing <15 kg needing rifampin and LPV/r-4:4 were enrolled in a pharmacokinetic study and underwent intensive pharmacokinetic sampling on 3 visits: (i) during the intensive and (ii) continuation phases of antituberculosis treatment with LPV/r-4:4 and (iii) 1 month after antituberculosis treatment completion on LPV/r-4:1. Pharmacometric modeling and simulation were used to compare exposures across weight bands with adult target exposures. Eighty-seven children with a median (interquartile range) age and weight of 19 (4 to 64) months and 8.7 (3.9 to 14.9) kg, respectively, were included in the abacavir analysis. Abacavir pharmacokinetics were best described by a two-compartment model with first-order elimination and transit compartment absorption. After allometric scaling adjusted for the effect of body size, maturation could be identified: clearance was predicted to be fully mature at about 2 years of age and to reach half of this mature value at about 2 months of age. Abacavir bioavailability decreased 36% during treatment with rifampin and LPV/r-4:4 but remained within the median adult recommended exposure, except for children in the 3- to 4.9-kg weight band, in which the exposures were higher. The observed predose morning trough concentrations were higher than the evening values. Though abacavir exposure significantly decreased during concomitant administration of rifampin and LPV/r-4:4, it remained within acceptable ranges. (This study is registered in ClinicalTrials.gov under identifier NCT02348177.)




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Drug Effect of Clofazimine on Persisters Explains an Unexpected Increase in Bacterial Load in Patients [Pharmacology]

Antituberculosis (anti-TB) drug development is dependent on informative trials to secure the development of new antibiotics and combination regimens. Clofazimine (CLO) and pyrazinamide (PZA) are important components of recommended standard multidrug treatments of TB. Paradoxically, in a phase IIa trial aiming to define the early bactericidal activity (EBA) of CLO and PZA monotherapy over the first 14 days of treatment, no significant drug effect was demonstrated for the two drugs using traditional statistical analysis. Using a model-based analysis, we characterized the statistically significant exposure-response relationships for both drugs that could explain the original findings of an increase in the numbers of CFU with CLO treatment and no effect with PZA. Sensitive analyses are crucial for exploring drug effects in early clinical trials to make the right decisions for advancement to further development. We propose that this quantitative semimechanistic approach provides a rational framework for analyzing phase IIa EBA studies and can accelerate anti-TB drug development.




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Adduct Formation of Delamanid with NAD in Mycobacteria [Mechanisms of Action]

Delamanid (DLM), a nitro-dihydroimidazooxazole derivative currently approved for pulmonary multidrug-resistant tuberculosis (TB) therapy, is a prodrug activated by mycobacterial 7,8-didemethyl-8-hydroxy 5-deazaflavin electron transfer coenzyme (F420)-dependent nitroreductase (Ddn). Despite inhibiting the biosynthesis of a subclass of mycolic acids, the active DLM metabolite remained unknown. Comparative liquid chromatography-mass spectrometry (LC-MS) analysis of DLM metabolites revealed covalent binding of reduced DLM with a nicotinamide ring of NAD derivatives (oxidized form) in DLM-treated Mycobacterium tuberculosis var. Bacille de Calmette et Guérin. Isoniazid-resistant mutations in the type II NADH dehydrogenase gene (ndh) showed a higher intracellular NADH/NAD ratio and cross-resistance to DLM, which were restored by complementation of the mutants with wild-type ndh. Our data demonstrated for the first time the adduct formation of reduced DLM with NAD in mycobacterial cells and its importance in the action of DLM.




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Erratum for Asempa et al., "In Vitro Activity of Imipenem-Relebactam Alone or in Combination with Amikacin or Colistin against Pseudomonas aeruginosa" [Errata]




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Distinct Mechanisms of Dissemination of NDM-1 Metallo-{beta}-Lactamase in Acinetobacter Species in Argentina [Epidemiology and Surveillance]

A 4-year surveillance of carbapenem-resistant Acinetobacter spp. isolates in Argentina identified 40 strains carrying blaNDM-1. Genome sequencing revealed that most were Acinetobacter baumannii, whereas seven represented other Acinetobacter spp. The A. baumannii genomes were closely related, suggesting recent spread. blaNDM-1 was located in the chromosome of A. baumannii strains and on a plasmid in non-A. baumannii strains. A resistance gene island carrying blaPER-7 and other resistance determinants was found on a plasmid in some A. baumannii strains.




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Enhanced Efflux Pump Expression in Candida Mutants Results in Decreased Manogepix Susceptibility [Mechanisms of Resistance]

Manogepix is a broad-spectrum antifungal agent that inhibits glycosylphosphatidylinositol (GPI) anchor biosynthesis. Using whole-genome sequencing, we characterized two efflux-mediated mechanisms in the fungal pathogens Candida albicans and Candida parapsilosis that resulted in decreased manogepix susceptibility. In C. albicans, a gain-of-function mutation in the transcription factor gene ZCF29 activated expression of ATP-binding cassette transporter genes CDR11 and SNQ2. In C. parapsilosis, a mitochondrial deletion activated expression of the major facilitator superfamily transporter gene MDR1.




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Antimicrobial Activity of Ceftolozane-Tazobactam and Comparators against Clinical Isolates of Haemophilus influenzae from the United States and Europe [Susceptibility]

Nine hundred Haemophilus influenzae clinical isolates from 83 U.S. and European medical centers were tested for susceptibility by reference broth microdilution methods against ceftolozane-tazobactam and comparators. Results were stratified by β-lactamase production and infection type. Overall, ceftolozane-tazobactam MIC50/90 values were 0.12/0.25 mg/liter, and 99.0% of isolates were inhibited at the susceptible breakpoint of ≤0.5 mg/liter; the highest MIC value was only 2 mg/liter. Our results support using ceftolozane-tazobactam to treat H. influenzae infections.




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Characterization of blaCTX-M-27/F1:A2:B20 Plasmids Harbored by Escherichia coli Sequence Type 131 Sublineage C1/H30R Isolates Spreading among Elderly Japanese in Nonacute-Care Settings [Mechanisms of Resistance]

We characterized 29 blaCTX-M-27-harboring plasmids of Escherichia coli sequence type 131 (ST131) sublineage C1/H30R isolates from healthy individuals and long-term-care facility (LTCF) residents. Most (27/29) plasmids were of the FIA, FIB, and FII multireplicon type with the same plasmid multilocus sequence typing (pMLST). Several plasmids (7/23) from LTCF residents harbored only blaCTX-M-27 as the resistance gene; however, their fundamental structures were very similar to those of previously isolated blaCTX-M-27/F1:A2:B20 plasmids, suggesting their prevalence as a newly arising public health concern.




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Predominant Distribution of OXA-48-Like Carbapenemase in Fecal Colonization [Letters]




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Molecular and Clinical Characterization of Multidrug-Resistant and Hypervirulent Klebsiella pneumoniae Strains from Liver Abscess in Taiwan [Epidemiology and Surveillance]

Hypervirulent Klebsiella pneumoniae strains are the major cause of liver abscesses throughout East Asia, and these strains are usually antibiotic susceptible. Recently, multidrug-resistant and hypervirulent (MDR-HV) K. pneumoniae strains have emerged due to hypervirulent strains acquiring antimicrobial resistance determinants or the transfer of a virulence plasmid into a classic MDR strain. In this study, we characterized the clinical and microbiological properties of K. pneumoniae liver abscess (KPLA) caused by MDR-HV strains in Taiwan. Patients with community onset KPLA were retrospectively identified at Taipei Veterans General Hospital during January 2013 to May 2018. Antimicrobial resistance mechanisms, capsular types, and sequence types were determined. MDR-HV strains and their parental antimicrobial-susceptible strains further underwent whole-genome sequencing (WGS) and in vivo mice lethality tests. Thirteen MDR-HV strains were identified from a total of 218 KPLA episodes. MDR-HV strains resulted in similar outcomes to antimicrobial-susceptible strains. All MDR-HV strains were traditional hypervirulent clones carrying virulence capsular types. The major resistance mechanisms were the overexpression of efflux pumps and/or the acquisition of ESBL or AmpC β-lactamase genes. WGS revealed that two hypervirulent strains had evolved to an MDR phenotype due to mutation in the ramR gene and the acquisition of an SHV-12-bearing plasmid, respectively. Both these MDR-HV strains retained high virulence compared to their parental strains. The spread of MDR-HV K. pneumoniae strains in the community raises significant public concerns, and measures should be taken to prevent the further acquisition of carbapenemase and other resistance genes among these strains in order to avoid the occurrence of untreatable KPLA.




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Unorthodox Parenteral {beta}-Lactam and {beta}-Lactamase Inhibitor Combinations: Flouting Antimicrobial Stewardship and Compromising Patient Care [Commentary]

In India and China, indigenous drug manufacturers market arbitrarily combined parenteral β-lactam and β-lactamase inhibitors (BL-BLIs). In these fixed-dose combinations, sulbactam or tazobactam is indiscriminately combined with parenteral cephalosporins, with BLI doses kept in ratios similar to those for the approved BL-BLIs. Such combinations have been introduced into clinical practice without mandatory drug development studies involving pharmacokinetic/pharmacodynamic, safety, and efficacy assessments being undertaken. Such unorthodox combinations compromise clinical outcomes and also potentially contribute to resistance development.




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The Novel Macrolide Resistance Genes mef(D), msr(F), and msr(H) Are Present on Resistance Islands in Macrococcus canis, Macrococcus caseolyticus, and Staphylococcus aureus [Mechanisms of Resistance]

Chromosomal resistance islands containing the methicillin resistance gene mecD (McRImecD) have been reported in Macrococcus caseolyticus. Here, we identified novel macrolide resistance genes in Macrococcus canis on similar elements, called McRImsr. These elements were also integrated into the 3' end of the 30S ribosomal protein S9 gene (rpsI), delimited by characteristic attachment (att) sites, and carried a related site-specific integrase gene (int) at the 5' end. They carried novel macrolide resistance genes belonging to the msr family of ABC subfamily F (ABC-F)-type ribosomal protection protein [msr(F) and msr(H)] and the macrolide efflux mef family [mef(D)]. Highly related mef(D)-msr(F) fragments were found on diverse McRImsr elements in M. canis, M. caseolyticus, and Staphylococcus aureus. Another McRImsr-like element identified in an M. canis strain lacked the classical att site at the 3' end and carried the msr(H) gene but no neighboring mef gene. The expression of the novel resistance genes in S. aureus resulted in a low-to-moderate increase in the MIC of erythromycin but not streptogramin B. In the mef(D)-msr(F) operon, the msr(F) gene was shown to be the crucial determinant for macrolide resistance. The detection of circular forms of McRImsr and the mef(D)-msr(F) fragment suggested mobility of both the island and the resistance gene subunit. The discovery of McRImsr in different Macrococcus species and S. aureus indicates that these islands have a potential for dissemination of antibiotic resistance within the Staphylococcaceae family.




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ISEcp1-Mediated Transposition Leads to Fosfomycin and Broad-Spectrum Cephalosporin Resistance in Klebsiella pneumoniae [Mechanisms of Resistance]

A fosfomycin-resistant and carbapenemase (OXA-48)-producing Klebsiella pneumoniae isolate was recovered, and whole-genome sequencing revealed ISEcp1-blaCTX-M-14b tandemly inserted upstream of the chromosomally encoded lysR-fosA locus. Quantitative evaluation of the expression of lysR and fosA genes showed that this insertion brought a strong hybrid promoter leading to overexpression of the fosA gene, resulting in fosfomycin resistance. This work showed the concomitant acquisition of resistance to broad-spectrum cephalosporins and fosfomycin due to a single genetic event.




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Encephalitozoon cuniculi Genotype III Evinces a Resistance to Albendazole Treatment in both Immunodeficient and Immunocompetent Mice [Experimental Therapeutics]

Of four genotypes of Encephalitozoon cuniculi, E. cuniculi genotype II is considered to represent a parasite that occurs in many host species in a latent asymptomatic form, whereas E. cuniculi genotype III seems to be more aggressive, and infections caused by this strain can lead to the death of even immunocompetent hosts. Although albendazole has been considered suitable for treatment of Encephalitozoon species, its failure in control of E. cuniculi genotype III infection has been reported. This study determined the effect of a 100x recommended daily dose of albendazole on an Encephalitozoon cuniculi genotype III course of infection in immunocompetent and immunodeficient mice and compared the results with those from experiments performed with a lower dose of albendazole and E. cuniculi genotype II. The administration of the regular dose of abendazole during the acute phase of infection reduced the number of affected organs in all strains of mice and absolute counts of spores in screened organs. However, the effect on genotype III was minor. Surprisingly, no substantial effect was recorded after the use of a 100x dose of albendazole, with larger reductions seen only in the number of affected organs and absolute counts of spores in all strains of mice, implying variations in albendazole resistance between these Encephalitozoon cuniculi genotypes. These results imply that differences in the course of infection and the response to treatment depend not only on the immunological status of the host but also on the genotype causing the infection. Understanding how microsporidia survive in hosts despite targeted antimicrosporidial treatment could significantly contribute to research related to human health.




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ARGONAUT II Study of the In Vitro Activity of Plazomicin against Carbapenemase-Producing Klebsiella pneumoniae [Mechanisms of Resistance]

Plazomicin was tested against 697 recently acquired carbapenem-resistant Klebsiella pneumoniae isolates from the Great Lakes region of the United States. Plazomicin MIC50 and MIC90 values were 0.25 and 1 mg/liter, respectively; 680 isolates (97.6%) were susceptible (MICs of ≤2 mg/liter), 9 (1.3%) intermediate (MICs of 4 mg/liter), and 8 (1.1%) resistant (MICs of >32 mg/liter). Resistance was associated with rmtF-, rmtB-, or armA-encoded 16S rRNA methyltransferases in all except 1 isolate.




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Correction: Senescence Sensitivity of Breast Cancer Cells Is Defined by Positive Feedback Loop between CIP2A and E2F1 [Correction]




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Pemigatinib Is Active in Some FGFR2-Altered Cholangiocarcinomas [Clinical Trials]

Pemigatinib was effective in patients with cholangiocarcinomas with FGFR2 fusions or rearrangements.




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Somatic Copy-Number Alterations Contribute to Brain Metastasis [Metastasis]

In lung cancer, brain metastasis was associated with somatic amplification of MYC, YAP1, or MMP13.




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Bemarituzumab Is Active in FGFR2b-High Gastroesophageal Adenocarcinoma [Clinical Trials]

The FGFR2b inhibitor bemarituzumab was effective in high-FGFR2b gastroesophageal adenocarcinoma.




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New Drug-Discovery Assay Identifies Novel Mutant-EGFR Inhibitors [Drug Discovery]

The MaMTH-DS assay detected inhibitors of mutant EGFR in non–small cell lung cancer cells.




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In This Issue [In This Issue]




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Protein Instability Is Targetable in Mismatch Repair-Deficient Tumors [Research Watch]

Mismatch repair (MMR)–deficient tumors exhibit proteome-wide protein instability and aggregation.




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Epigenetic Therapy Can Suppress Premetastatic Changes in the Lung [Metastasis]

Low-dose adjuvant epigenetic therapy (AET) reduced metastasis and promoted survival in mouse models.




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Non-Stem Cells Seed Colorectal Cancer Metastases and Gain Stem Traits [Metastasis]

LGR5 cells seed colorectal cancer metastases and produce stemlike LGR5+ outgrowth-promoting cells.




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Gastrin Blocks Symmetric Stem-Cell Division and Gastric Tumorigenesis [Gastric Cancer]

Symmetric division of stem cells positive for gastrin receptor CCK2R is linked to gastric cancer.




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Comparative single-cell RNA sequencing (scRNA-seq) reveals liver metastasis-specific targets in a patient with small intestinal neuroendocrine cancer [RESEARCH REPORT]

Genomic analysis of a patient's tumor is the cornerstone of precision oncology, but it does not address whether metastases should be treated differently. Here we tested whether comparative single-cell RNA sequencing (scRNA-seq) of a primary small intestinal neuroendocrine tumor to a matched liver metastasis could guide the treatment of a patient's metastatic disease. Following surgery, the patient was put on maintenance treatment with a somatostatin analog. However, the scRNA-seq analysis revealed that the neuroendocrine epithelial cells in the liver metastasis were less differentiated and expressed relatively little SSTR2, the predominant somatostatin receptor. There were also differences in the tumor microenvironments. RNA expression of vascular endothelial growth factors was higher in the primary tumor cells, reflected by an increased number of endothelial cells. Interestingly, vascular expression of the major VEGF receptors was considerably higher in the liver metastasis, indicating that the metastatic vasculature may be primed for expansion and susceptible to treatment with angiogenesis inhibitors. The patient eventually progressed on Sandostatin, and although consideration was given to adding an angiogenesis inhibitor to her regimen, her disease progression involved non-liver metastases that had not been characterized. Although in this specific case comparative scRNA-seq did not alter treatment, its potential to help guide therapy of metastatic disease was clearly demonstrated.




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[Molecular Pathology] The Formation of Coronary Vessels in Cardiac Development and Disease

Understanding how coronary blood vessels form and regenerate during development and progression of cardiac diseases will shed light on the development of new treatment options targeting coronary artery diseases. Recent studies with the state-of-the-art technologies have identified novel origins of, as well as new, cellular and molecular mechanisms underlying the formation of coronary vessels in the postnatal heart, including collateral artery formation, endocardial-to-endothelial differentiation and mesenchymal-to-endothelial transition. These new mechanisms of coronary vessel formation and regeneration open up new possibilities targeting neovascularization for promoting cardiac repair and regeneration. Here, we highlight some recent studies on cellular mechanisms of coronary vessel formation, and discuss the potential impact and significance of the findings on basic research and clinical application for treating ischemic heart disease.




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[Cell Biology] Recent Insights on Inflammasomes, Gasdermin Pores, and Pyroptosis

Inflammasomes assemble in the cytosol of myeloid and epithelial cells on sensing of cellular stress and pathogen-associated molecular patterns and serve as scaffolds for recruitment and activation of inflammatory caspases. Inflammasomes play beneficial roles in host and immune responses against diverse pathogens but may also promote inflammatory tissue damage if uncontrolled. Gasdermin D (GSDMD) is a recently identified substrate of murine caspase-1 and caspase-11, and human caspases-1, -4, and -5 that mediates a regulated lytic cell death mode termed pyroptosis. Recent studies have identified pyroptosis as a critical inflammasome effector mechanism that controls inflammasome-dependent cytokine secretion and contributes to antimicrobial defense and inflammasome-mediated autoinflammatory diseases. Here, we review recent developments on inflammasome-associated effector functions with an emphasis on the emerging roles of gasdermin pores and pyroptosis.




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[Molecular Pathology] Pharmacologic Approaches for Adapting Proteostasis in the Secretory Pathway to Ameliorate Protein Conformational Diseases

Maintenance of the proteome, ensuring the proper locations, proper conformations, appropriate concentrations, etc., is essential to preserve the health of an organism in the face of environmental insults, infectious diseases, and the challenges associated with aging. Maintaining the proteome is even more difficult in the background of inherited mutations that render a given protein and others handled by the same proteostasis machinery misfolding prone and/or aggregation prone. Maintenance of the proteome or maintaining proteostasis requires the orchestration of protein synthesis, folding, trafficking, and degradation by way of highly conserved, interacting, and competitive proteostasis pathways. Each subcellular compartment has a unique proteostasis network compromising common and specialized proteostasis maintenance pathways. Stress-responsive signaling pathways detect the misfolding and/or aggregation of proteins in specific subcellular compartments using stress sensors and respond by generating an active transcription factor. Subsequent transcriptional programs up-regulate proteostasis network capacity (i.e., ability to fold and degrade proteins in that compartment). Stress-responsive signaling pathways can also be linked by way of signaling cascades to nontranscriptional means to reestablish proteostasis (e.g., by translational attenuation). Proteostasis is also strongly influenced by the inherent kinetics and thermodynamics of the folding, misfolding, and aggregation of individual proteins, and these sequence-based attributes in combination with proteostasis network capacity together influence proteostasis. In this review, we will focus on the growing body of evidence that proteostasis deficits leading to human pathology can be reversed by pharmacologic adaptation of proteostasis network capacity through stress-responsive signaling pathway activation. The power of this approach will be exemplified by focusing on the ATF6 arm of the unfolded protein response stress responsive-signaling pathway that regulates proteostasis network capacity of the secretory pathway.




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Erratum. Therapeutic Inertia Is a Problem for All of Us. Clinical Diabetes 2019;37:105-106 (DOI: 10.2337/cd19-0009)




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Erratum. Diabetes Is Primary: Timely News and Notes for Primary Care Providers. Clinical Diabetes 2020;38:4-8 (DOI: 10.2337/cd20-dp01)




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A Case of Euglycemic Diabetic Ketoacidosis Triggered by a Ketogenic Diet in a Patient With Type 2 Diabetes Using a Sodium-Glucose Cotransporter 2 Inhibitor




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Good to Know: Kidney Disease: Signs and Treatment




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Diabetes Technologies: We Are All in This Together




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Distribution of Highly Prevalent Musculoskeletal Disorders and Their Association With Diabetes Complications in a Population of 140 Individuals With Type 1 Diabetes: A Retrospective Study in a French Diabetes Center

Although they are usually not considered to be diabetes complications, musculoskeletal disorders (MSKDs) are common in individuals with type 1 or type 2 diabetes and can strongly interfere with daily diabetes care, especially in people using diabetes technologies. The authors of this retrospective study in a population of 140 patients with type 1 diabetes report the distribution of subtypes of MSKDs and speculate about the mechanisms involved. The authors emphasize the need for multidisciplinary care involving not only the diabetes care team but also orthopedic surgeons. This report should lead to large, prospective studies to increase knowledge about these under-studied complications.




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Beneficial Agents for Patients With Type 2 Diabetes and Cardiovascular Disease or Obesity: Utilization in an Era of Accumulating Evidence

This study was an analysis of a national sample of U.S. medical office visits from 2014 to 2016, a period when evidence of effectiveness was emerging for a variety of beneficial type 2 diabetes agents with regard to potential reduction in diabetes comorbidities. Ideal therapy was defined as an American Diabetes Association–identified beneficial agent plus metformin. The associations between atherosclerotic cardiovascular disease or obesity and use of these agents were explored.




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Establishment of the T1D Exchange Quality Improvement Collaborative (T1DX-QI)

The T1D Exchange established a learning platform by evaluating the current state of care and engaging 10 diabetes clinics in collaborative quality improvement (QI) activities. Participating clinics are sharing data and best practices to improve care delivery for people with type 1 diabetes. This article describes the design and initial implementation of this platform, known as the T1D Exchange Quality Improvement Collaborative. This effort has laid a foundation for learning from variation in type 1 diabetes care delivery via QI methodology and has demonstrated success in improving processes through iterative testing cycles and transparent sharing of data.




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Diabetic Kidney Disease: It Don&#x2019;t Get No Respect




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Lipid Trait Variants and the Risk of Non-Hodgkin Lymphoma Subtypes: A Mendelian Randomization Study

Background:

Lipid traits have been inconsistently linked to risk of non-Hodgkin lymphoma (NHL). We examined the association of genetically predicted lipid traits with risk of diffuse large B-cell lymphoma (DLBCL), chronic lymphocytic leukemia (CLL), follicular lymphoma (FL), and marginal zone lymphoma (MZL) using Mendelian randomization (MR) analysis.

Methods:

Genome-wide association study data from the InterLymph Consortium were available for 2,661 DLBCLs, 2,179 CLLs, 2,142 FLs, 824 MZLs, and 6,221 controls. SNPs associated (P < 5 x 10–8) with high-density lipoprotein (HDL, n = 164), low-density lipoprotein (LDL, n = 137), total cholesterol (TC, n = 161), and triglycerides (TG, n = 123) were used as instrumental variables (IV), explaining 14.6%, 27.7%, 16.8%, and 12.8% of phenotypic variation, respectively. Associations between each lipid trait and NHL subtype were calculated using the MR inverse variance–weighted method, estimating odds ratios (OR) per standard deviation and 95% confidence intervals (CI).

Results:

HDL was positively associated with DLBCL (OR = 1.14; 95% CI, 1.00–1.30) and MZL (OR = 1.09; 95% CI, 1.01–1.18), while TG was inversely associated with MZL risk (OR = 0.90; 95% CI, 0.83–0.99), all at nominal significance (P < 0.05). A positive trend was observed for HDL with FL risk (OR = 1.08; 95% CI, 0.99–1.19; P = 0.087). No associations were noteworthy after adjusting for multiple testing.

Conclusions:

We did not find evidence of a clear or strong association of these lipid traits with the most common NHL subtypes. While these IVs have been previously linked to other cancers, our findings do not support any causal associations with these NHL subtypes.

Impact:

Our results suggest that prior reported inverse associations of lipid traits are not likely to be causal and could represent reverse causality or confounding.




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Objectively-Measured Light-Intensity Physical Activity and Risk of Cancer Mortality: A Meta-analysis of Prospective Cohort Studies

Background:

The impact of light-intensity physical activity (LPA) in preventing cancer mortality has been questioned. To address this concern, the present meta-analysis aimed to quantify the association between objectively-measured LPA and risk of cancer mortality.

Methods:

We conducted a systematic literature search in PubMed and Scopus to January 2020. Prospective cohort studies reporting the association between objectively-measured LPA using activity monitors (e.g., accelerometers) and risk of cancer mortality in the general population were included. The summary hazard ratios (HR) per 30 min/day of LPA and 95% confidence intervals (CI) were obtained using a random-effects model. Dose–response analysis was used to plot their relationship.

Results:

Five prospective cohort studies were included, in which the definition of LPA based on accelerometer readings was mainly set within 100 to 2,100 counts/min. The summary HR for cancer mortality per 30 min/day of LPA was 0.86 (95% CI, 0.79–0.95; I2 < 1%), and the association between LPA and risk reduction in cancer mortality was linearly shaped (Pnonlinearity = 0.72). LPA exhibited a comparable magnitude of risk reduction in cancer mortality of moderate-to-vigorous physical activity regardless of equal time-length (0.87 per 30 min/day vs. 0.94 per 30 min/day, Pinteraction = 0.46) or equal amount (0.74 vs. 0.94 per 150 metabolic equivalents-min/day, Pinteraction = 0.11). Furthermore, replacing sedentary time by LPA of 30 min/day decreased the risk of cancer mortality by 9%.

Conclusions:

Objectively-measured LPA conferred benefits in decreasing the risk of cancer mortality.

Impact:

LPA should be considered in physical activity guidelines to decrease the risk of cancer mortality.




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Prediagnostic Circulating Levels of Sex Steroid Hormones and SHBG in Relation to Risk of Ductal Carcinoma In Situ of the Breast among UK Women

Background:

Sex steroid hormones and sex hormone–binding globulin (SHBG) have been implicated in the etiology of invasive breast cancer, but their associations with risk of the precursor lesion, ductal carcinoma in situ (DCIS) of the breast, remain unclear.

Methods:

We used Cox proportional hazards regression models to estimate the associations of serum levels of estradiol (premenopausal women only), testosterone, and/or SHBG with DCIS risk among 182,935 women. After a median follow-up of 7.1 years, 186 and 531 DCIS cases were ascertained in premenopausal and postmenopausal women, respectively.

Results:

Total and free estradiol were positively associated with risk of DCIS among premenopausal women. The HRs for the highest versus the lowest tertiles were 1.54 (1.06–2.23) and 1.72 [95% confidence interval (CI), 1.15–2.57], respectively. Among postmenopausal women, elevated levels of free testosterone (FT), and to a lesser extent, total testosterone, were positively associated with DCIS risk. The HRs for the highest versus the lowest quartiles were 1.42 (95% CI, 1.09–1.85) and 1.16 (95% CI, 0.91–1.48), respectively. Serum SHBG levels were inversely associated with risk of DCIS among postmenopausal women (HRq4 vs. q1: 0.75; 95% CI, 0.56–0.99).

Conclusions:

This study suggests that elevated levels of estradiol are associated with increased risk of DCIS among premenopausal women, and that among postmenopausal women, elevated levels of testosterone, and particularly those of FT, are associated with increased DCIS risk, while elevated levels of SHBG are associated with reduced risk.

Impact:

These findings may be helpful in developing prevention strategies aimed at reducing breast cancer risk among premenopausal and postmenopausal women.




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Red and Processed Meat, Poultry, Fish, and Egg Intakes and Cause-Specific and All-Cause Mortality among Men with Nonmetastatic Prostate Cancer in a U.S. Cohort

Background:

Research on the relationship of meat, fish, and egg consumption and mortality among prostate cancer survivors is limited.

Methods:

In the Cancer Prevention Study-II Nutrition Cohort, men diagnosed with nonmetastatic prostate cancer between baseline in 1992/1993 and 2015 were followed for mortality until 2016. Analyses of pre- and postdiagnosis intakes of red and processed meat, poultry, fish, and eggs included 9,286 and 4,882 survivors, respectively. Multivariable-adjusted RRs and 95% confidence intervals (CI) were estimated using Cox proportional hazards models.

Results:

A total of 4,682 and 2,768 deaths occurred during follow-up in pre- and postdiagnosis analyses, respectively. Both pre- and postdiagnosis intakes of total red and processed meat were positively associated with all-cause mortality (quartile 4 vs. 1: RR = 1.13; 95% CI, 1.03–1.25; Ptrend = 0.02; RR = 1.22; 95% CI, 1.07–1.39; Ptrend = 0.03, respectively), and both pre- and postdiagnosis poultry intakes were inversely associated with all-cause mortality (quartile 4 vs. 1 RR = 0.90; 95% CI, 0.82–0.98; Ptrend = 0.04; RR = 0.84; 95% CI, 0.75–0.95; Ptrend = 0.01, respectively). No associations were seen for prostate cancer–specific mortality, except that higher postdiagnosis unprocessed red meat intake was associated with lower risk.

Conclusions:

Higher red and processed meat, and lower poultry, intakes either before or after prostate cancer diagnosis were associated with higher risk of all-cause mortality.

Impact:

Our findings provide additional evidence that prostate cancer survivors should follow the nutrition guidelines limiting red and processed meat consumption to improve overall survival. Additional research on the relationship of specific meat types and mortality is needed.




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Pancreatic Cancer Risk in Relation to Lifetime Smoking Patterns, Tobacco Type, and Dose-Response Relationships

Background:

Despite smoking being a well-established risk factor for pancreatic cancer, there is a need to further characterize pancreatic cancer risk according to lifespan smoking patterns and other smoking features, such as tobacco type. Our aim was to deeply investigate them within a large European case–control study.

Methods:

Tobacco smoking habits and other relevant information were obtained from 2,009 cases and 1,532 controls recruited in the PanGenEU study using standardized tools. Multivariate logistic regression analysis was performed to evaluate pancreatic cancer risk by smoking characteristics and interactions with other pancreatic cancer risk factors. Fractional polynomials and restricted cubic splines were used to test for nonlinearity of the dose–response relationships and to analyze their shape.

Results:

Relative to never-smokers, current smokers [OR = 1.72; 95% confidence interval (95% CI), 1.39–2.12], those inhaling into the throat (OR = 1.48; 95% CI, 1.11–1.99) or chest (OR = 1.33; 95% CI, 1.12–1.58), and those using nonfiltered cigarettes (OR = 1.69; 95% CI, 1.10–2.61), were all at an increased pancreatic cancer risk. Pancreatic cancer risk was highest in current black tobacco smokers (OR = 2.09; 95% CI, 1.31–3.41), followed by blond tobacco smokers (OR = 1.43; 95% CI, 1.01–2.04). Childhood exposure to tobacco smoke relative to parental smoking was also associated with increased pancreatic cancer risk (OR = 1.24; 95% CI, 1.03–1.49). Dose–response relationships for smoking duration, intensity, cumulative dose, and smoking cessation were nonlinear and showed different shapes by tobacco type. Effect modification by family history of pancreatic cancer and diabetes was likely.

Conclusions:

This study reveals differences in pancreatic cancer risk by tobacco type and other habit characteristics, as well as nonlinear risk associations.

Impact:

This characterization of smoking-related pancreatic cancer risk profiles may help in defining pancreatic cancer high-risk populations.