Cytochrome P450 3A4 (CYP3A4) is a major drug‐metabolizing enzyme that is widely investigated. So far, no homozygous inactive variant has been described. We report on a 19‐year‐old kidney transplant ...patient suffering from Alport syndrome, who experienced unexpected high tacrolimus plasma trough levels during immunosuppressant therapy. Because nonadherence, liver failure, or drug–drug interactions could be excluded, we hypothesized a diminished metabolism of the drug caused by mutations in the main detoxification enzyme, CYP3A4. Exome sequencing revealed a novel single‐nucleotide polymorphism (c.802C>T) resulting in a premature stop codon in CYP3A4 exon 5. Accordingly, no CYP3A4 protein could be detected in kidney biopsy tissue, and there was lack of expression in HepG2 cells transiently transfected with the mutated CYP3A4. In addition, the patient harbored inactive CYP3A5*3, resulting in loss of function of the entire CYP3A locus, explaining the deteriorated tacrolimus clearance. This is, to our knowledge, the first case of a complete failure of CYP3A4 in humans.
Clinical Pharmacology & Therapeutics (2014); 95 4, 416–422. doi:10.1038/clpt.2013.210
The nature of the micro-flora present in sputa of six different cystic fibrosis (CF) patients was assessed using routine microbiological culture and molecular methods. Bacterial genes for the small ...subunit ribosomal RNA (ssu rDNA) were specifically amplified from DNA extracted from the sputum samples, cloned and characterised by hybridisation and DNA sequencing. A large number of clones from six sputa were screened. Initially, oligonucleotide hybridisation was performed with five probes, specific for Gram-positives and Gram-negatives in general and the main pathogens for the CF patient (
Staphylococcus aureus,
Pseudomonas aeruginosa and
Haemophilus influenzae). For a single sputum sample, the results were fully congruent when culture and molecular methods were compared. In the other five sputa, discrepancies for
S. aureus and/or
H. influenzae were documented. Although
S. aureus DNA and
H. influenzae DNA was detected in three and four sputa, respectively, strains could not be cultured. Although the PCR approach is not capable of distinguishing viable from dead bacteria, all of the CF patients had a history of
S. aureus infections, while one of the CF patients once had cultivable
H. influenzae in the sputum as well. A number of clones for probe-unidentified Gram-negative or Gram-positive bacterial species were further analysed by sequencing and additional potential pathogens were identified. Although routine culture of sputum frequently points to mono-specific exacerbations, our molecular data indicate that the other CF-related pathogens appear to be persistently present as well. We conclude that routine culture for bacterial pathogens from CF sputa yields limited microbiological information since it frequently fails to identify a number of pathogenic bacterial species that are potentially present in a viable status in the lungs of these patients.
Objective To evaluate the effect of different treatment strategies on enterohaemorrhagic Escherichia coli O104:H4 induced haemolytic uraemic syndrome.Design Multicentre retrospective case-control ...study.Setting 23 hospitals in northern Germany.Participants 298 adults with enterohaemorrhagic E coli induced haemolytic uraemic syndrome.Main outcome measures Dialysis, seizures, mechanical ventilation, abdominal surgery owing to perforation of the bowel or bowel necrosis, and death.Results 160 of the 298 patients (54%) temporarily required dialysis, with only three needing treatment long term. 37 patients (12%) had seizures, 54 (18%) required mechanical ventilation, and 12 (4%) died. No clear benefit was found from use of plasmapheresis or plasmapheresis with glucocorticoids. 67 of the patients were treated with eculizumab, a monoclonal antibody directed against the complement cascade. No short term benefit was detected that could be attributed to this treatment. 52 patients in one centre that used a strategy of aggressive treatment with combined antibiotics had fewer seizures (2% v 15%, P=0.03), fewer deaths (0% v 5%, p=0.029), required no abdominal surgery, and excreted E coli for a shorter duration.Conclusions Enterohaemorrhagic E coli induced haemolytic uraemic syndrome is a severe self limiting acute condition. Our findings question the benefit of eculizumab and of plasmapheresis with or without glucocorticoids. Patients with established haemolytic uraemic syndrome seemed to benefit from antibiotic treatment and this should be investigated in a controlled trial.
Regenerative therapies offer attractive alternatives for the treatment of osteochondral defects. Adipose-derived stromal vascular fraction (SVF) cells allow the development of one-step surgical ...procedures by their abundant availability and high frequency. In this pilot study we evaluated the in vivo safety, feasibility, and efficacy of this concept using scaffolds seeded with freshly isolated (SVF) or cultured adipose stem cells (ASCs), and compared these to their acellular counterparts. Osteochondral defects were created in medial condyles and trochlear grooves in knees of eight goats. Defects were filled with acellular collagen I/III scaffolds or scaffolds seeded with SVF cells or cultured ASCs. Osteochondral regeneration was evaluated after 1 and 4 months by macroscopy, immunohistochemistry, biomechanical analysis, microCT analysis, and biochemistry. After 1 month, no adverse effects were noted. Microscopic, but not macroscopic evaluation showed considerable yet not significant differences, with cell-loaded constructs showing more extensive regeneration. After 4 months, acellular constructs displayed increased regeneration, however, to a lesser degree than cell-treated constructs. The latter exhibited more extensive collagen type II, hyaline-like cartilage, and higher elastic moduli, and their glycosaminoglycan content in the cartilaginous layer better approached native tissue values. Moreover, their defect regions contained higher levels of regenerated, mature subchondral bone with more intense collagen type I staining. SVF cells tended to perform best on all parameters. In summary, this pilot study demonstrated the preclinical safety and feasibility of a one-step surgical procedure for osteochondral defect regeneration. Similar regeneration was found between freshly isolated SVF cells and cultured ASCs. Larger studies with longer follow-up are required to substantiate these findings.
The objective of this study was to determine time trends in the rate of Gram-positive cocci in 42 Dutch ICUs that continuously used or did not use selective oropharyngeal decontamination (SOD) or ...selective decontamination of the digestive tract (SDD) and ICUs that introduced SOD/SDD.
The Dutch Surveillance System on Antibiotic Resistance was used to determine monthly rates of Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium isolates, including resistant phenotypes, in blood and respiratory tract specimens from 2008 to 2013. Per patient, the last isolate per species per month was selected, and cumulative rates per 100 beds per month were determined. Time trends were analysed by multilevel Poisson regression.
Eighteen ICUs used SOD/SDD (1296 months), 13 did not use SOD/SDD (936 months) and 11 introduced SOD/SDD (373 months before and 419 months after introduction). There was no significant increase in the rate of Gram-positive cocci in ICUs that used SOD/SDD. Introduction of SOD/SDD was associated with increased rates of S. aureus (β = 0.018, 95% CI 0.006-0.030) and E. faecalis isolates (β = 0.028, 95% CI 0.006-0.051) in respiratory tract specimens. Numbers of resistant phenotypes remained low, and an observed increase in E. faecium isolates (β = 0.033, 95% CI 0.012-0.054), 97% of which were resistant to ampicillin, in the absence of SOD/SDD disappeared after the introduction of SOD/SDD.
In ICUs with a low endemicity of resistance, introduction of SOD/SDD was associated with increased rates of S. aureus and E. faecalis isolates, but not with resistant phenotypes. Continuous 5 year use of SOD/SDD was not associated with increased isolation of Gram-positive cocci.
Varicella universal vaccination (UV) has been implemented in many countries for several years. Nevertheless, varicella UV remains debated in Europe and few data are available on the real burden of ...infection. We assessed the burden of varicella in Belgium through analysis of hospitalised cases during a 1-year period.
Data on children admitted to hospital with varicella were collected through a national network from November 2011 to October 2012. Inclusion criteria were either acute varicella or related complications up to 3 weeks after the rash.
Participation of 101 hospitals was obtained, covering 97.7% of the total paediatric beds in Belgium. 552 children were included with a median age of 2.1 years. Incidence of paediatric varicella hospitalisations reached 29.5/10(5) person-years, with the highest impact among those 0-4 years old (global incidence and odds of hospitalisation: 79/10(5) person-years and 1.6/100 varicella cases, respectively). Only 14% (79/552) of the cohort had an underlying chronic condition. 65% (357/552) of children had ≥1 complication justifying their admission, 49% were bacterial superinfections and 10% neurological disorders. Only a quarter of children (141/552) received acyclovir. Incidence of complicated hospitalised cases was 19/10(5) person-years. Paediatric intensive care unit admission and surgery were required in 4% and 3% of hospitalised cases, respectively. Mortality among Belgian paediatric population was 0.5/10(6) and fatality ratio 0.2% among our cohort.
Varicella demonstrated a substantial burden of disease in Belgian children, especially among the youngest. Our thorough nationwide study, run in a country without varicella UV, offers data to support varicella UV in Belgium.
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