Tribological Investigation of Textured Surfaces in Starved Lubrication Conditions.

The present work investigates the friction reduction capability of two types of micro-textures (grooves and dimples) created on steel surfaces using a vertical milling machine. The wear studies were conducted using a pin-on-disc tribometer, with the results indicating a better friction reduction capacity in the case of the dimple texture as compared to the grooved texture. The microscopic images of the pin surface revealed deep furrows and significant damage on the pin surfaces of the groove-textured disc. An optimization of the textured surfaces was performed using an artificial neural network (ANN) model, predicting the influence of the surface texture as a function of the load, depth of cut and distance between the micro-textures.

Evidence of sexual transfer of mycobacteria from male to female partners reporting to an IVF clinic.

Female genital tuberculosis (GTB) contributes significantly to infertility in low- and middle-income countries. Dissemination of infection from pulmonary and extrapulmonary sites is the major reason for causation of GTB. Additionally, sexual transmission of GTB from male partners has been reported. We selected 81 couples desiring babies from an in vitro fertilization clinic. We used multiplex-PCR for mycobacterial detection in semen of males, in the endometrium of their female counterparts and in the products of conception (POC) from miscarriage. Data interpretation shows that these pregnancies failed owing to sexual transmission of mycobacteria. We noticed by multiplex PCR that mycobacterial infestation in the female can take place in either endometrium or POC from asymptomatic males harbouring mycobacteria in their semen. Therefore, we propose sexual transfer of mycobacteria to be a probable cause of miscarriage. Thus, we suggest multiplex PCR based screening of semen for all males of the couples attempting successful childbirth.

Chronic inflammation in polycystic ovary syndrome: A case-control study using multiple markers.

BACKGROUND: Polycystic ovary syndrome (PCOS) is associated with insulin resistance and elevated risk of cardiovascular disease and diabetes. Chronic inflammation has been observed in PCOS in several studies but there is also opposing evidence and a dearth of research in Indians. OBJECTIVE: To estimate chronic inflammation in PCOS and find its relationship with appropriate anthropometric and biochemical parameters. MATERIALS AND METHODS: Chronic inflammation was assessed in 30 women with PCOS (Group A) and 30 healthy controls (Group B) with highly sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6), tumour necrosis factor alpha (TNFα), and platelet microparticles (PMP). In group A, the relationship of chronic inflammation with insulin resistance, waist hip ratio (WHR) serum testosterone, and serum glutamate pyruvate transaminase (SGPT) were examined. RESULTS: In group A, the hsCRP, TNFα, and PMP were significantly elevated compared to group B. However, IL-6 level was similar between the groups. In group A, PMP showed a significant positive correlation with waist-hip ratio and serum testosterone. IL-6 showed a significant positive correlation with insulin sensitivity and significant negative correlation with insulin resistance and serum glutamate pyruvate transaminase. CONCLUSION: PCOS is associated with chronic inflammation and PMP correlates positively with central adiposity and biochemical hyperandrogenism in women with PCOS.

Visual contrast sensitivity could be an early marker of diabetic retinopathy.

The present study aimed to explore the early predictive marker of diabetic retinopathy (DR) and to elucidate the associated demographic, metabolic, and ocular factors. We enrolled 43 type 2 diabetic subjects with mild non-proliferative retinopathy (MNPDR), 30 diabetic subjects with no retinopathy (DNR), and 35 healthy controls (HC). The study groups showed no significant alteration in central macular thickness (CMT) and visual acuity (VA). The contrast sensitivity (CS) score was found to be significantly lower among DNR and MNPDR subjects compared to HCs (p < 0.0001). Between MNPDR and DNR subjects, the CS score was significantly lower in the former (p = 0.0036). CS score discriminated DNR subjects from HC, with 74% accuracy for the optimal threshold 0.71. The associated area under the ROC curve (AUC) is 0.82 (p < 0.0001) while the discrimination rule has 66% sensitivity and 80% specificity. The CS score also discriminated MNPDR subjects from DNR with 64% accuracy for the optimal threshold 0.53. The associated AUC is 0.65 (p < 0.023) and the rule has 86% sensitivity and 33% specificity. According to best subset regression analysis, not only glycaemic parameters but also lipid parameters [low-density lipoprotein cholesterol (LDL-C) (p = 0.045) and triglycerides (TG) (p = 0.0005)] were found to be significant predictors of CS. CMT (p = 0.058) was another marginally significant predictor of CS. CS may be used as an early predictive marker for DR. So, not only hyperglycemia, but also hyperlipidemia seems to significantly affect retinal CS function in diabetes.

Genomic Reduction at TTC Repeats in the Bacterial Genome of Treated Cases of Hansen's Disease: A Possible Survival Mechanism of Mycobacterium leprae.

INTRODUCTION: Mycobacterium leprae has a small genome and a tendency of persisting as a very low-grade infection. The authors have shown earlier, that the changes in TTC repeats, in M. leprae genome may contribute to the restriction of the pathogenicity of the bacterium and its survival strategy in case of pure neural Hansen's disease. We suspect, that a similar genomic reduction if happens in treated cases of Hansen's disease, can be a determining factor for developing persisters and relapse. AIM: The present study aimed to find out if there was any evidence of genomic reduction in treated cases of Hansen's disease that showed microbiological nonresponse. METHODS: Skin biopsies were taken from treated cases of Hansen's disease at tertiary centers in Kolkata and at Raipur who had bacterial index (BI) unchanged or increased compared to their pretreatment BI. Analysis for the mutation in rpoB gene and folP1 gene were done to rule out rifampicin and dapsone resistance, respectively. The entire TTC repeat region of the bacteria was amplified by polymerase chain reaction and was subjected to sequencing. The obtained sequences were then analyzed by CLUSTALW. RESULTS: A total of 127 patients were included in the study of which in 52 the BI remained same and 75 had an increase in BI, even after 6 months of completion of multidrug therapy. Among the samples, 2 had positive rpoB gene mutation. No mutation was found in the folP1 gene. The TTC repeat of both the rpoB-resistant samples was found to have 17 copies, which matched their pretreatment copy number. In other 125 cases, 60 cases showed no change from their pretreatment TTC number. Of those 65 samples that showed evidence of genomic reduction, 11 samples showed one copy, 41 showed 2 copies, and 13 showed 3 copies deletion. We also observed a significant regional variation. CONCLUSION: We concluded that there was evidence of genomic reduction, which might lead to microbiological nonresponse in treated cases of Hansen's disease. This indicated a possibility of future persistence and relapse.

Multiplex PCR from Menstrual Blood: A Non-Invasive Cost-Effective Approach to Reduce Diagnostic Dilemma for Genital Tuberculosis.

AIM: Genital tuberculosis (GTB) is a potent contributor to irreversible damage to the reproductive system and infertility in females. As no gold standard diagnostic tool is yet available, clinical suspicion and relatively insensitive approaches such as histopathology, laparoscopy and hysterosalpingogram are currently critical determinants in the diagnosis of GTB. Although a polymerase chain reaction (PCR)-based assay using endometrial tissue seems promising, sampling does require an invasive procedure. OBJECTIVE: We hypothesized that menstrual blood may provide an alternate non-invasive source of samples for PCR-based GTB diagnosis. METHODS: We enrolled 195 women with primary infertility in whom GTB was suspected. We obtained ethics committee approval from our institution and written informed consent from subjects. Endometrial tissue and menstrual blood was collected from the subjects and culture, histopathology, and multiplex PCR with both sample type was performed for each subject. RESULTS: The sensitivity and specificity of multiplex PCR was, respectively, 90.2 and 86.1% for menstrual blood, 95.8 and 84.3% for endometrial tissue, and 64.8 and 93.2% for histopathology staining. CONCLUSIONS: A strong clinical suspicion aided with multiplex PCR using menstrual blood may significantly reduce the diagnostic dilemma for GTB diagnosis in a non-invasive, sensitive, rapid, and cost-effective manner.

Biochemical scenario behind initiation of diabetic retinopathy in type 2 diabetes mellitus.

Purpose: Despite the disease having similar glycemic status and duration microangiopathy in some patients develop within few years whereas it doesn't appear as a health complication in some diabetics for a considerable period. This study is undertaken to assess the hyperglycemia-induced biochemical background behind the development of diabetic retinopathy (DR) in type 2 diabetes mellitus (DM). Methods: Following proper diagnosis, 100 patients of type 2 DM of 10-12 years duration having no DR, and 42 patients of type 2 DM of the same duration and glycemic status as the second group, with mild retinopathy were recruited in the study. Lactic acid, glutamate, malondialdehyde (MDA), nitrate, advanced glycation end-products (AGEs), peripheral blood mononuclear cell reactive oxygen species (ROS), vascular endothelial growth factor (VEGF), and its receptor 2 (VEGFR2) in these two groups were produced in an assay following standard methodology. Results: Biochemical markers of anaerobic glycolysis, lipid peroxidation, AGEs, glutamate concentration, oxidative stress, and expression of VEGF and its VEGFR2 with significantly elevated markings were found in them who developed earliest stage of DR rather than them who had not. Conclusion: Hyperglycemia-induced anomalous glucose metabolism, lipid peroxidation, advanced glycation, glutamate toxicity, and oxidative stress create a background where apoptosis of retinal capillary endothelial cells invite increased expression of VEGF and VEGFR2, these being the crucial factors behind the development of diabetic microangiopathy.

Use of Fine Needle Aspirate from Peripheral Nerves of Pure-neural Leprosy for Cytology and Polymerase Chain Reaction to Confirm the Diagnosis: A Follow-up Study of 4 Years.

BACKGROUND: Pure neural leprosy (PNL) still remains a diagnostic challenge because of the absence of sine qua non skin lesions of leprosy and a confirmatory diagnostic method. The authors had earlier described a simple yet objective technique of combining fine needle aspiration cytology (FNAC) coupled with a multiplex polymerase chain reaction (PCR) in a pilot study, wherein the technique showed promise of a reliable diagnostic tool. In the pursuit of further evidence, the authors carried out a 4-year study with PNL cases to find the efficacy and reliability of the said method in a larger sample size. AIM: This study was conducted to find the efficacy, reliability, and reproducibility of FNAC coupled with multiplex PCR and Ziehl-Neelsen (ZN) staining in identifying the cases of PNL. MATERIALS AND METHODS: All cases that were suspected to be suffering from PNL, following evaluation by two independent observers were included in the study and were subjected to FNAC from the affected nerve, and the aspirates were evaluated for cytology, ZN staining, and multiplex PCR for Mycobacterium leprae genome. In addition, serum anti-PGL1 levels were also performed in all the study subjects. Fifteen non-PNL cases were also included in the control arm. RESULTS: A total of 47 cases were included in the test arm and subjected to FNAC. Conventional ZN staining could demonstrate acid-fast bacilli (AFB) in only 15 out of 47 cases (31.91%) while M. leprae DNA could be elicited in 37 (78.72%) cases by the multiplex PCR. Only 13 (27.65%) out of 47 cases showed anti-PGLI-1 antibody positivity. On cytological examination of the nerve aspirates, only 11 (23.40%) cases showed epithelioid cells whereas nonspecific inflammation was seen in 26 (75.60%) cases. CONCLUSION: The results of this study conducted over a larger sample size corroborate with the findings of our pilot study. In a resource poor set up, FNAC in combination with ZN staining and multiplex PCR is a rapid, simple, and easily performed test, which can give a reproducible and objective diagnosis in cases of PNL.

Molecular characterization and evaluation of the emerging antibiotic-resistant Streptococcus pyogenes from eastern India.

BACKGROUND: Group A Streptococcus strains causing wide variety of diseases, recently became noticeable in eastern India, are not amenable to standard treatment protocol thus enhancing the possibility of disease morbidity by becoming antibiotic resistance. METHODS: The association of Lancefield group A Streptococcal variation with degree of vir architectural diversity was evaluated using emm typing and restriction fragment length polymorphism analyses. The antibiotic sensitivity patterns were examined by modified Kirby-Bauer method of disk diffusion. Percentage calculations, 95% confidence interval and one-way ANOVA were used to assess differences in proportions. RESULTS: Our observations revealed 20 different emm types and 13 different HaeIII vir typing patterns. A 1.2 kb fragment was found in all HaeIII typing pattern. Fragments of 1.2 kb and 550 bp were conserved in majority of the isolates. HinfI digestion was found proficient in differentiating the strains of same vir typing patterns. Strong predominance of speC (85%) and speF (80%) genes have been observed encoding exotoxins production. 4 isolates were found to be erythromycin resistant and were of genotype emm49. High degree of tetracycline resistance was shown by 53.57% isolates which belonged to 12 different emm genotypes. CONCLUSIONS: These findings suggested that in addition to emm typing, sequential application of HaeIII and HinfI restriction enzymes in vir typing analysis is an effective tool for group A streptococcal molecular characterization associated with antibiotic resistance.