Specific insulin assays, insulin sensitivity and blood pressure

Serum insulin concentrations have been used as markers of insulin resistance in population studies examining the relationship between insulin resistance and blood pressure, but the relationship is variable among studies. We hypothesized that differences in cross-reactivity of insulin assays with proinsulin and its split/des-amino products might account for the variation. We therefore examined fasting and post- glucose load serum insulin concentrations (determined by both specific and conventional assays), insulin sensitivity (measured by the euglycaemic clamp technique), and blood pressure, in a group of 56 diabetic (NIDDM) and non-diabetic subjects. Insulin concentrations as measured by the two methods were highly correlated (r = 0.97, p < 0.0001), and the relationships among serum insulin concentrations, insulin sensitivity and blood pressure were independent of assay method; for example, in non-diabetic subjects the univariate correlation between log10AUC insulin and insulin sensitivity index was similar with both methods [r = -0.81 vs. r = -0.82, p < 0.0001 (specific vs. conventional assay)]. Discrepancies between studies in the relationship between serum insulin concentrations and blood pressure are unlikely to be due to cross-reactivity of conventional insulin assays with proinsulin-like molecules.      

Polymorphous light eruption

Polymorphous light eruption (PLE) is a common idiopathic photosensitivity disorder with an estimated prevalence of 10-20%. It is characterized by an intermittent skin reaction to ultraviolet (UV) radiation exposure, consisting of non-scarring pruritic erythematous papules, vesicles or plaques that develop on light-exposed skin. Despite the different morphology in different individuals, the eruption tends to have a monomorphous presentation in any single subject. The histopathological features of PLE are distinct and comprise a perivascular lymphocytic infiltrate in the dermis, subepidermal oedema and variable epidermal changes. The pathogenesis of PLE is not well known, but findings suggest that it is a delayed-type hypersensitivity reaction to one or more UV-modified cutaneous antigens. The principal action of PLE is mainly in the UVA region, although some subjects exhibit sensitivity to UVB alone or to both UVA and UVB radiation at the same time. Preventive measures in PLE include the regular use of photoprotective methods combined with graduated exposures to natural sunlight. The induction of immune tolerance by phototherapy and photochemotherapy are useful prophylactic methods in moderate to severe cases. The role of systemic agents in the management of PLE is under investigation. This article reviews the epidemiological, pathogenetic and clinical aspects of PLE and discusses recent advances in the diagnostic approach and management of this condition.     

Evaluation of antibacterial,antifungal and modulatory activity of methanol and ethanol extracts of Padina sanctae-crucis

Background

Multi-resistantmicroorganisms such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida tropicalis e Candida krusei are the main causes of microbial infections. Padina sanctae-crucis is a seaweed often used to check the contamination of ecosystems by materials such as heavy metals, but studies of the antimicrobial activity of the same seaweed were not found.

Methods

The tests for the minimum inhibitory concentration and modulation of microbial resistance, with the use of ethanolic and methanolic extracts of Padina Sanctae-cruces combined with drugs of the class of aminoglycosides and antifungal were used to evaluate the activity against the cited microorganisms.

Results

Was observed a modulation of antibiotic activity between the natural products and the E. coli and S. aureus strains, indicating a synergism and antagonism respectively.

Conclusions

The results showed a moderate modulatory effect against some microorganisms studied.     

Reemergence of Chloramphenicol Sensitivity in Enteric Fever

Background

Enteric fever is a global health problem and rapidly developing resistance to various drugs makes the situation more alarming. Drug sensitivity in Salmonella enterica serovar typhi and Salmonella enterica serovar paratyphi A isolated from 45 blood culture positive cases of enteric fever was tested to determine in-vitro susceptibility pattern of prevalent strains in northern India.

Methods

Strains isolated from 45 blood culture positive cases of typhoid and paratyphoid fever over a period of three years were studied and their sensitivity patterns to chloramphenicol, ampicillin, ciprofloxacin, ceftriaxone, nalidixic acid, amikacin and ofloxacin were analysed.

Results

Our results show a high sensitivity of both Salmonella enterica serovar typhi (96%) and Salmonella enterica serovar paratyphi A (100%) to chloramphenicol. Sensitivity to ciprofloxacin and amikacin was 88% and 84% respectively. All the isolates were sensitive to ofloxacin, nalidixic acid and ceftriaxone. Sensitivity of Salmonella enterica serovar paratyphi A was 100% to chloramphenicol, ciprofloxacin, ofloxacin, nalidixic acid and ceftriaxone, 95% to amikacin and 30% to ampicillin. Overall 44 out of 45 isolates of Salmonellae were sensitive to chloramphenicol.

Conclusion

These findings suggest changing pattern of antibiotic resistance in enteric fever with reemergence of chloramphenicol sensitivity in northern India.Key Words: Enteric fever, Chloramphenicol, Salmonella enterica serovar typhi, Salmonella enterica serovar paratyphi A     

Steady‐state amprenavir and tenofovir pharmacokinetics after coadministration of unboosted or ritonavir‐boosted fosamprenavir with tenofovir disoproxil fumarate in healthy volunteers

Objective

An open‐label, three‐period pharmacokinetic study was conducted to investigate the drug interaction potential between fosamprenavir (FPV) and tenofovir disoproxil fumarate (TDF).

Methods

Thirty‐six healthy subjects received TDF 300 mg once daily (qd) for 7 days (period 1), and then were randomized to 14 days of either FPV 1400 mg twice daily (bid) or FPV/ritonavir (RTV) 700/100 mg bid alone or with TDF (period 2). Subjects continued their randomized dose of FPV for 14 more days, adding or removing TDF based upon its receipt in period 2 (period 3). Twenty‐four‐hour pharmacokinetic sampling was carried out on day 7 of period 1 and on day 14 of periods 2 and 3. Steady‐state plasma amprenavir (APV) and tenofovir (TFV) pharmacokinetics were assessed by noncompartmental analysis and parameter values observed with each regimen were compared using geometric mean ratios with 90% confidence intervals.

Results

After TDF coadministration, APV geometric mean minimum concentration (C_min), maximum concentration (C_max), and area under the plasma concentration–time curve (AUC) increased by 31, 3 and 7% above values observed with unboosted FPV alone; they also increased by 31, 4 and 16% above values observed with FPV/RTV alone. TFV C_min, C_max and AUC decreased by 12, 25 and 15% after FPV coadministration and by 9, 18 and 7% after FPV/RTV coadministration. No significant changes in RTV pharmacokinetics were observed. No differences were noted in adverse events among dosing periods.

Conclusions

In this evaluation of the interaction between FPV and TDF, increases in APV exposures and modest decreases in TFV exposures were observed. These were unlikely to be clinically significant.

     

Comparative evaluation of gustatory function between postmenopausal women and age‐matched men

Oral Diseases (2010) 16 , 469–475 Objective: The aim of the study was to compare the gustatory function between postmenopausal women and age‐matched men. Subjects and methods: During a period of 4 months, 30 postmenopausal women and 30 age‐matched men were prospectively evaluated for gustatory function. Each subject was given a symptoms questionnaire for self‐assessment of taste function. Then, whole mouth taste test was performed in which the quality identification and intensity ratings of taste solutions were measured. Results: Regarding correct quality identification, the results were statistically non‐significant (P > 0.05). As far as the intensity judgments are concerned, significant difference exists between postmenopausal women and age‐matched men. Intensity of taste perception for sucrose was significantly lower in postmenopausal women than intensity of taste perception for other tastes (P < 0.05). One of the noticeable findings is that 15 (50%) postmenopausal women reported a change in dietary habits; all expressed liking for sweeter food. Conclusion: Postmenopausal women appeared to have a reduced perception of sucrose, which can alter eating habits, such as intake of more sweet foods, whereas no significant difference is observed in taste perception of NaCl, citric acid and quinine hydrochloride between postmenopausal women and age‐matched men. Fifteen (50%) postmenopausal women stated fondness for sweet taste.     

Improved retroviral transfer of genes into canine hematopoietic progenitor cells kept in long-term marrow culture

Amphotropic helper-free retroviral vectors containing either the bacterial neomycin phosphotransferase gene (NEO) or a mutant dihydrofolate reductase gene (DHFR*) were used to infect canine hematopoietic progenitor cells. In previous experiments, successful transfer and expression of both genes in canine CFU-GM were achieved after 24-hour cocultivation with virus-producing cells. The average rate of gene expression was 10% (6% to 16%) as measured by the number of CFU-GM resistant to either the aminoglycoside G418 or methotrexate. In an attempt to increase the efficiency of gene transfer, marrow was cocultured for 24 hours with either NEO or DHFR* virus-producing packaging cells and then kept in long-term marrow culture fed three times with virus-containing supernatant (2 to 5 x 10(6) CFU/mL). After six days, cells were harvested and cultured in CFU-GM assay with and without a selective agent. The average rate of gene expression in CFU- GM in five independent experiments was 46% and ranged from 19% to 87%. In conclusion, the efficiency of gene transfer into canine hematopoietic progenitor cells has been increased fourfold by combining cocultivation with long-term marrow culture as compared with results obtained with cocultivation only.