Comparative analysis of different methods used for molecular characterization of Burkholderia cepacia complex isolated from noncystic fibrosis conditions

PurposeBurkholderia is a Gram-negative opportunistic bacterium capable of causing severe nosocomial infections. The aim of this study was to characterize Burkholderia cepacia complex and to compare different molecular methods used in its characterization.MethodsIn this study, 45 isolates of Burkholderia cepacia complex (Bcc) isolated from clinical cases were subjected to RAPD (Random amplified polymorphic DNA), recA-RFLP (Restriction fragment length polymorphism), 16SrDNA-RFLP, whole-cell protein analysis, recA DNA sequencing and biofilm assay.ResultsOf the 45 isolates tested, 97.7% were sensitive to ceftazidime, 82.2% were sensitive to Cotrimoxazole, 73.3% were sensitive to meropenem, 55.5% were sensitive to minocycline and 42.2% were sensitive to levofloxacin. Majority of the isolates harbored all the tested virulence genes except bpeA and cblA. The RAPD generated 11 groups (R1-R11), recA-RFLP 10 groups (A1-A10), 16SrRNA-RFLP 5 groups (S1–S5) and SDS-PAGE (Sodium Dodecyl Sulphate-Polyacrylamide gel electrophoresis) whole cell protein analysis revealed 12 groups (C1–C12). recA sequencing revealed that most of the isolates belonging to the genomovar III Burkholderia cenocepacia. Though all the methods are found to be efficient in differentiating Burkholderia spp., recA-RFLP was highly discriminatory at 96% similarity value. The study also identified a new strain Burkholderia pseudomultivorans for the first time in the country. Further, recA sequencing could identify the strains to species level. Majority of the multidrug-resistant strains also showed moderate to strong biofilm-forming ability, which further contributes to the virulence characteristics of the pathogens.ConclusionsThe study highlights the importance of combination of molecular methods to characterize Burkholderia cepacia complex. Molecular typing of these human pathogens yields important information for the clinicians in order to initiate the most appropriate therapy in the case of severe infections and to implement preventive measures for the effective control of transmission of Burkholderia spp.     

Diabetes mellitus in Asian Indian children and adolescents

AIM: To study the clinical and metabolic profile of type 1 and type 2 diabetes mellitus in children and adolescents in a South Asian population. RESEARCH DESIGN AND METHODS: Sixty children were recruited. They were divided into three groups: Group I--type 2 diabetes mellitus (DM2), Group II--type 1 diabetes mellitus (DM1), and Group III--healthy controls. The clinical history and biochemical parameters (HbA1c, serum insulin, C-peptide, triglycerides, total cholesterol and HDL-cholesterol) were recorded. Homeostasis model assessment for insulin resistance (HOMAIR) and quantitative insulin sensitivity check index (QUICKI) were calculated. RESULTS AND CONCLUSIONS: Children and adolescents with DM2 had a significant family history of DM and clinical features of insulin resistance, including increased body mass index, waist:hip ratio and acanthosis nigricans. They also had decreased insulin sensitivity together with dyslipidemia of metabolic syndrome, i.e. high triglyceride, high total cholesterol and low HDL-cholesterol. The presence of these predictors of cardiovascular disorders is known to contribute to morbidity and mortality. Hence, DM2 needs to be recognized early in Asian Indian children.     

In vitro leishmanicidal activity of 3-substituted isocoumarins: synthesis and structure activity relationship

Twenty-five 3-substituted isocoumarins were synthesized using cutting edge microwave-assisted technology in high yields. The syntheses of different isocoumarins were carried out in a single step by the direct condensation of homophthalic acid with aryol and acyl chlorides under the solvent-free conditions without any solid support. The structures of all the synthesized compounds were characterized using different spectroscopic techniques including UV, IR, (1)HNMR and EIMS and purity was confirmed by CHN analysis. All the synthesized compounds were tested for in vitro leishmanicidal activity. Compounds 3a, 3b, 3g, 3l, 3m, 3r, 3t, 3w, 3x, and 3y displayed potential in vitro leishmanicidal activity with IC(50) values in the range of 0.56-84.38 microg/ml, whereas standard inhibitors amphotericine B have IC(50) = 0.24 microg/ml. The compounds 3b, 3g, 3m, 3t, 3w, 3x, and 3y having IC(50) values 27.86, 28.88, 36.49, 34.37, 28.68, 0.89 and 0.56 microg/ml, respectively, were most active among the present series while remaining others were found less active. The compound 3x and 3y can act as potential lead molecules for further development of isocoumarin-based new drugs for the treatment of leishmaniasis.     

Dengue determinants: Necessities and challenges for universal dengue vaccine development

Dengue illness can range from mild illness to life-threatening haemorrhage. It is an Aedes-borne infectious disease caused by the dengue virus, which has four serotypes. Each serotype acts as an independent infectious agent. The antibodies against one serotype confer homotypic immunity but temporary protection against heterotypic infection. Dengue has become a growing health concern for up to one third of the world's population. Currently, there is no potent anti-dengue medicine, and treatment for severe dengue relies on intravenous fluid management and pain medications. The burden of dengue dramatically increases despite advances in vector control measures. These factors underscore the need for a vaccine. Various dengue vaccine strategies have been demonstrated, that is, live attenuated vaccine, inactivated vaccine, DNA vaccine, subunit vaccine, and viral-vector vaccines, some of which are at the stage of clinical testing. Unfortunately, the forefront candidate vaccine is less than satisfactory, and its performance depends on serostatus and age factors. The lessons from clinical studies depicted ambiguity concerning the efficacy of dengue vaccine. Our study highlighted that viral structural heterogeneity, epitope accessibility, autoimmune complications, genetic variants, genetic diversities, antigen competition, virulence variation, host-pathogen specific interaction, antibody-dependent enhancement, cross-reactive immunity among Flaviviruses, and host-susceptibility determinants not only influence infection outcomes but also hampered successful vaccine development. This review integrates dengue determinants allocated necessities and challenges, which would provide insight for universal dengue vaccine development.     

Sublingual misoprostol versus intravenous oxytocin in prevention of post-partum hemorrhage

Background

Post-partum hemorrhage (PPH) is the most common direct cause of maternal mortality and timely intervention can save many lives.

Objective

To compare the effectiveness of sublingual misoprostol to intravenous oxytocin in preventing post-partum hemorrhage in low risk vaginal birth.

Methods

One hundred patients with no risk factor for PPH were randomly allocated to receive 600 μg misoprostol administered sublingually or 10 IU of intravenous oxytocin immediately after the delivery of baby. Main outcome measures were post-partum blood loss, drop in hemoglobin in 24 h, duration of third stage of labor, and drug-related adverse effects.

Results

Mean age, parity and gestational age were similar in both groups. Mean blood loss was significantly lower in oxytocin group (114.28 ± 26.75 versus 149.50 ± 30.78 ml; p = 0.00). Drop in hemoglobin was 0.31 ± 0.16 versus 0.49 ± 0.21 g% (p = 0.01) in oxytocin and misoprostol group, respectively. Duration of third stage labor was shorter in oxytocin group (median 5 min, IQR: 4.5–5.5 versus 5.5 min, IQR: 5–6 min, p < 0.01). Although fever and shivering were common adverse effects with misoprostol but were not clinically significant.

Conclusion

Intravenous oxytocin is more efficacious than sublingual misoprostol in preventing PPH in institutional deliveries.     

A Study of Cervical Intraepithelial Neoplasia in Pregnancy

Objective

To find the incidence of human papillomavirus (HPV) infection and cervical intraepithelial neoplasia (CIN) in pregnant women and compare Pap smear with the HPV DNA test in detecting HPV infection.

Materials and Methods

Hundred antenatal women, irrespective of gestational age, were enrolled as subjects in this prospective pilot study for blood investigations, wet mount examination of cervical discharge, Pap smear, and high-risk HPV DNA detection of cervical scrape by PCR. Women showing abnormality in Pap smear and/or those who were high-risk HPV DNA positive were subjected to colposcopy.

Results

The incidence of HPV-positive pregnant women was 18 %. Koilocytosis on Pap smear was observed in six women. Three high-risk HPV DNA-positive women showed changes consistent with CIN 1 on colposcopy.

Conclusions

The HPV DNA test is the most sensitive and reliable in detecting HPV infection as compared to Pap smear, but considering the cost of PCR, Pap smear screening of all antenatal women was recommended.     

Amiodarone effects on thyrotropin receptors and responses stimulated by thyrotropin and carbachol in cultured dog thyroid cells

Amiodarone is an antiarrhythmic drug that often induces thyroid disorders. Its effects on several aspects of thyroid function were studied using cultured dog thyroid cells. Within 5-60 min of incubation of cell membranes with amiodarone, there were profound changes in adenylate cyclase activity and TSH receptor binding. Amiodarone specifically decreased TSH-stimulated adenylate cyclase activity, but not the basal or forskolin-stimulated activities, while it increased the binding of 125I-labeled TSH to its receptors. Significant effects were seen with 5-10 microM amiodarone, with maximal effects at 50-100 microM, when TSH-stimulated adenylate cyclase activity was completely blocked and the labeled TSH binding increased 4- to 5-fold over control. These effects of amiodarone were reversible, since membranes exposed to 50 microM amiodarone for 1 h exhibited normal binding and cyclase activities, when amiodarone was removed by washing before the assay. The above effects of amiodarone were also observed when cells, instead of membranes, were treated with the drug, although the magnitude of changes was less than in membranes. Lower concentrations of amiodarone (10-25 microM) caused significant inhibition of iodide organification, without affecting iodide uptake, while higher concentrations (50-100 microM) inhibited organification by nearly 75% and uptake by about 20%. Amiodarone (10-100 microM) also inhibited [3H]2-deoxy-glucose uptake and the increase in intracellular calcium concentration in response to TSH and carbachol. In contrast to membranes, treatment of cells with amiodarone caused persistent inhibition of TSH-stimulated cAMP formation and iodide organification even 24-48 h after removal of the drug. However, amiodarone had no effect on cell viability, as judged by trypan blue exclusion and ability to remain attached to the culture dishes. These results suggest that amiodarone has specific inhibitory effects on agonist-stimulated functions in thyroid cells, possibly by interfering with TSH-receptor interactions and also at the level of cholinergic receptors.     

Problems of Psychological Monitoring in Astronaut Training

在进行职业训练时，对受训者的心理变化趋势进行监视是必要的。航天员心理因素的发展水平可通过心理测试来检测，以便能对其重要的心理指标进行评价，并给出综合评价。文中列出应进行测试的心理指标，并根据大量的样本统计给出了经验加权因子。测试结果的积累可以预测航天员将来飞行任务中处理复杂问题的能力，并能帮助改进训练过程及暴露缺点。     

On the measurement of absolute cerebral blood volume (CBV) using vascular‐space‐occupancy (VASO) MRI

Recently, a vascular‐space‐occupancy (VASO) MRI technique was developed for quantitative assessment of cerebral blood volume (CBV). This method uses the T₁‐shortening effect of gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA) with imaging parameters chosen that null the precontrast blood magnetization but allow the postcontrast blood magnetization to recover to equilibrium. A key advantage of VASO CBV estimation is that it provides a straightforward procedure for converting MR signals to absolute physiologic values. However, as with other T₁‐based steady‐state approaches, several important factors need to be considered that influence the accuracy of CBV values obtained with VASO MRI. Here, the transverse relaxation (T₂/T) effect in VASO MRI was investigated using multiecho spin‐echo and gradient‐echo experiments, resulting in underestimation of CBV by 14.9% ± 1.1% and 16.0% ± 2.5% for spin echo (TE = 10 ms) and gradient echo (TE = 6 ms), respectively. In addition, the influence of contrast agent clearance was studied by acquiring multiple postcontrast VASO images at 2.2‐min intervals, which showed that the concentration of Gd‐DTPA in the first 14 min (single dose) was sufficient for the blood magnetization to fully recover to equilibrium. Finally, the effect of vascular Gd‐DTPA leakage was assessed for scalp tissue, and signal extrapolation as a function of postinjection time was demonstrated to be useful in minimizing the associated errors. Specific recommendations for VASO MRI acquisition and processing strategies are provided. Magn Reson Med, 2009. © 2008 Wiley‐Liss, Inc.