Liquid chromatography-tandem mass spectrometry methods for quantification of total and free antibiotic concentrations in serum and exudate from patients with post-sternotomy deep sternal wound infection receiving negative pressure wound therapy

BACKGROUND

Systemically administered antibiotics are thought to penetrate the wounds more effectively during negative pressure wound therapy (NPWT).To test this hypothesis total and free antibiotic concentrations were quantified in serum and wound exudate.

METHODS

UHPLC-MS/MS methods were developed and validated for the determination of ceftazidime, cefepime, cefotaxime, cefuroxime, cefazolin, meropenem, oxacillin, piperacillin with tazobactam, clindamycin, ciprofloxacin, sulfamethoxazole/trimethoprim (cotrimoxazole), gentamicin, vancomycin, and linezolid. The unbound antibiotic fraction was obtained by ultrafiltration using a Millipore Microcon-30kda Centrifugal Filter Unit. Analysis was performed on a 1.7-µm Acquity UPLC BEH C18 2.1 × 100-mm column with a gradient elution.

RESULTS

The validation was performed for serum, exudates and free fractions. For all matrices, requirements were met regarding linearity, precision, accuracy, limit of quantitation, and matrix effect. The coefficient of variation was in the range of 1.2-13.6%.and the recovery 87.6-115.6%, respectively. Among the 29 applications of antibiotics thus far, including vancomycin, clindamycin, ciprofloxacin, oxacillin, cefepime, cefotaxime, cotrimoxazole, and gentamicin, total and free antibiotic concentrations in serum and exudate were correlated.

CONCLUSION

This method can accurately quantify the total and free concentrations of 16 antibiotics. Comparison of concentration ratios between serum and exudates allows for monitoring individual antibiotics' penetration capacity in patients receiving NPWT.

[Pregnancy outcomes in women with gestational diabetes: specific subgroups might require increased attention]

OBJECTIVES

To compare peri-partal parameters between two groups of pregnant women - with and without gestational diabetes mellitus (GDM), to correlate degree of glucose abnormality with incidence of peri-partal morbidity and, finally, to analyse the potential effect of comorbidities (i.e. obesity, hypertension, thyreopathy, polycystic ovary syndrome, trombophylia, anemia, allergy, smoking) on pregnancy outcomes.

DESIGN

Epidemiological observational "case-control" study.

SETTING

Department of Obstetric and Gynaecology, Faculty Hospital Brno; Department of Internal Medicine, Diabetes Centre, Faculty Hospital Brno; Department of Pathophysiology, Faculty of Medicine, Masaryk University, Brno.

METHODS

The study comprised 432 pregnant women (364 with GDM diagnosis, 68 healthy controls) followed during a period 2011-2013. GDM was diagnosed by oral glucose tolerance test in 24-28th week of gestation (by fasting plasma glucose >5,6 mmol/l or >8,8 mmol/l in 60th min or >7,8 mmol/l in 120th min post-75g glucose load). Following peri-partal parameters were studied: ultrasonographic examination before delivery, a date of delivery, length of childbirth, induction, perinatal complications, post-delivery complications, section, abnormity in pH, base excess, Apgar score, birth weight.

RESULTS

Subjects with GDM had significantly increased rate of labour induction compared to healthy controls (P = 0.0035, chi-square test). Subgroup of GDM women classified as having a higher risk for adverse perinatal outcomes by a definition of Czech Obstetric and Gynaecology Society had significantly more labour inductions, more sections and instrumental deliveries. New-borns of those mothers had significantly more common worse perinatal outcomes (Apgar score and macrosomia).

CONCLUSION

Based on our data risk stratification of GDM subjects according to Czech Obstetric and Gynaecology Society appears relevant and justified.

Genetic and functional analyses of MRAS and HNF1A genes in diabetes and diabetic nephropathy

Evidence has recently indicated that the MRAS and HNF1A genetic polymorphisms are associated with coronary artery disease. The MRAS and HNF1A genes are located on chromosomes 3q and 12q within the regions where associations with diabetes and diabetic nephropathy occur. We thus performed genetic and functional analyses of these two genes to evaluate their impacts on diabetes and diabetic nephropathy. MRAS and HNF1A genetic polymorphisms were genotyped in 1399 Czech subjects including non-diabetic controls (339), type 1 (243) and type 2 (817) diabetic patients with and without diabetic nephropathy using TaqMan allelic discrimination. Gene expression levels in the kidneys of diabetic Goto-Kakizaki and Wistar rats were detected with real-time RT-PCR. Despite no significance in genetic analysis of diabetic subjects, SNP rs2259816 in the HNF1A gene tended to associate with diabetic nephropathy in type 1 diabetic patients. The hnf1a gene expression was significantly decreased in kidney tissues of Goto-Kakizaki rats compared to Wistar and insulin-treated Goto-Kakizaki rats. There was neither significant association in the MRAS genetic polymorphism with diabetic nephropathy nor variation of mras gene expression in the kidneys of Goto-Kakizaki and Wistar rats. Data from the present study have not proved any significant association of the MRAS and HNF1A genetic polymorphisms with diabetes and diabetic nephropathy in a cohort of Czech population. However, the functional analysis and the trend in genetic analysis suggest that the HNF1A gene may have primary genetic impact on the development of diabetic nephropathy.