Machining of circular micro holes by electrochemical micro-machining process     

Alok Kumar Das  P. Saha  AlokKumarDas·ParthaSaha 《上海大学学报(英文版)》2013,(4):314-319

Machining of micro holes with micro electro- chemical machining （micro ECM） process has been carried out with an indigenously developed set up. This paper describes relevant problems and solutions for the circular micro holes machining process on 304 stainless steel sheets with 60 μm thickness using high speed steel cylindrical tool of diameter 500 ~tm and using dilute I-I2SO4 as elec- trolyte. The taper angle variation of the machined hole is analyzed and reported for different experimental setting parameters. The minimum value of the taper angle of machined holes is achieved at the parameter setting of 0.4 mol/L H2504, 700 kHz, 600 ns and 21 V, for stainless steel sheets and HSS tool.  相似文献   

Role of Cytokines in the Pathogenesis of Non-Alcoholic Fatty Liver Disease     

Das SK  Balakrishnan V 《Indian journal of clinical biochemistry : IJCB》2011,26(2):202-209

A number of factors are linked with non-alcoholic fatty liver diseases (NAFLD), a condition that ranges from clinically benign fatty liver to its more severe form, non alcoholic steatohepatitis (NASH). In this study, we evaluated the role of cytokines secreted from adipose tissue in the pathogenesis and progression of NAFLD. We also compared anthropometric profile, lipid profile and insulin resistance data in 105 NAFLD patients with 77 normal subjects. These subjects showed a normal serum albumin level, prothrombin time and renal function but elevated aminotransferases. Predisposing factors were diabetes mellitus (35%), overweight (56%) and hyperlipidemia (44%). Insulin resistance (IR), determined by homeostasis model assessment (HOMA) was confirmed in 70% patients with NAFLD and 42% patients fulfilled the minimum criteria for insulin resistance syndrome (IRS). NAFLD patients showed elevated levels of pro-inflammatory cytokines tumor necrosis factor (TNF)-α, and interleukin (IL)-6, while anti-inflammatory cytokines IL-4 level decreased and IL-10 level remain unchanged; however, TGF-β1 level elevated significantly compared to normal subjects. While insulin level and HOMA-IR both were significantly positively correlated with BMI, waist-to-hip ratio, total cholesterol, VLDL-cholesterol, triglyceride and TGF-β1; glucose, IL-6 and TNF-α levels were significantly positively correlated with HOMA-IR only. In conclusion, pro-inflammatory cytokines play an important link between metabolic and liver disorders in the fat accumulation, and thereby cause IR, inflammation and liver fibrosis.  相似文献   

Cell Free Fetal DNA: Marker for Predicting Pregnancy Outcomes     

Subir Kumar Das  Mriganka Mouli Saha 《Indian journal of clinical biochemistry : IJCB》2017,32(3):251-252

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Association of Vitamin D Receptor (FokI and BsmI) Gene Polymorphism with Bone Mineral Density and Their Effect on 25-Hydroxyvitamin D Level in North Indian Postmenopausal Women with Osteoporosis     

Israr Ahmad  Tabrez Jafar  Farzana Mahdi  Md. Arshad  Siddharth Kumar Das  Shah Waliullah  Abbas Ali Mahdi 《Indian journal of clinical biochemistry : IJCB》2018,33(4):429-437

Osteoporosis is a systemic disease with a strong genetic component. Vitamin D receptor (VDR) has been suggested as a candidate gene for osteoporosis. Therefore the present study was aimed to investigate the pattern of allelic variants of VDR gene polymorphism (FokI and BsmI), its influence on vitamin D levels and bone mineral density (BMD) in North Indian postmenopausal women with osteoporosis for possible genetic association. 254 postmenopausal osteoporotic women and 254 postmenopausal non osteoporotic women were included in the study. VDR FokI and BsmI gene polymorphism gene were assessed by the PCR-RFLP method. Serum 25-hydroxyvitamin D was measured by the ELISA. BMD at the L₁–L₄ lumbar spine, hip, forearm and femoral neck was assessed by dual energy X-ray absorptiometry. The average BMD at spine and hip in postmenopausal women with bb and spine, hip, femoral neck and forearm with ff genotype had significantly low BMD. The frequency of ff genotype and f allele was significantly higher in postmenopausal osteoporotic women when compared with postmenopausal non osteoporotic women. However, no significant association was found between the genotypes and vitamin D levels. Our study reveals that VDR gene FokI and BsmI polymorphism is significantly associated with low bone mineral density. Therefore the ff genotype and f allele of VDR FokI gene may be used as an important risk factor for osteoporosis.  相似文献   

Ophthalmic Presentation of Disseminated Tuberculosis with Relapse-Immunological Profile     

Bineeta Kashyap  Nisha Goyal  G. K. Das  N. P Singh  I. R. Kaur 《Indian journal of clinical biochemistry : IJCB》2018,33(4):483-486

TB as the cause of uveitis varies from 0.5 to 10.5%; low sensitivity of confirmatory laboratory investigations and inconsistency of diagnostic criteria leads to paucity of data. Diagnosis requires a high level of suspicion and is often presumptive based on indirect evidences. Interferon gamma, Interleukin-2 and Neopterin are key biomarkers in immuno-regulation of Mycobacterium tuberculosis infection. The relative shift from Interleukin-2 towards Interferon gamma (Interferon gamma/Interleukin-2) is more discriminatory for active tuberculosis. Protein carbonyl and Malondialdehyde, as oxidative stress markers, characterize active tuberculosis. A case of disseminated TB presenting with acute uveitis had a recurrent tubercular lymphadenitis after completing category I treatment under revised national tuberculosis control programme. The present study evaluates the potential utility of above mentioned biomarkers to predict atypical presentation in difficult cases of tuberculosis. Though tuberculous uveitis is amenable to treatment in early course of disease, the delay in diagnosis can have serious consequences for the patient.  相似文献   

Effect of lecithin in the treatment of ethanol mediated free radical induced hepatotoxicity     

Subir Kumar Das  D. M. Vasudevan 《Indian journal of clinical biochemistry : IJCB》2006,21(1):62-69

Alcoholic liver disease (ALD) develops as a consequence of priming and sensitizing mechanisms rendered by cross-interactions of primary mechanistic factors and secondary risk factors. Liver damage due to consumption of alcohol may be caused by oxygen radicals such as superoxide and hydroxyl radicals, generated during the metabolism of ethanol by the microsomal oxidizing system. Lecithin, an important class of phospholipids contains choline, which is considered as lipotropic factor. The effects of this lecithin as a hepatoprotective drug on body weight and antioxidant status of ethanol-exposed rats were studied. The results were compared with the effects of tocopheryl acetate. From the present study, it can be concluded that ethanol-induced stress can be partly prevented by tocopheryl acetate, and showed best result. Abstination from alcohol also involved for little hepatic regeneration. Supplementation of lecithin showed better effect compared to abstination from alcohol on reversing the effect of ethanol induced liver damage in the present study. Moreover, preventive measures were found to be better than curative treatment. Antioxidants are likely to provide beneficial effects on hepatocyes via desensitization against oxidant stress while inhibiting primary mechanism for expression of proinflammatory and cytotoxic mediators. However, abstinence from alcohol, proper nutrition, and supplementation of antioxidants, vitamins and hepatoprotective drugs are some of the therapeutic options.  相似文献   

Binding and degradation of native and acetylated low density lipoproteins by monocyte derived macrophages of normal and hypercholesterolemic rabbits     

Sabari Das  Snehlata  L M Srivastava 《Indian journal of clinical biochemistry : IJCB》1997,12(1):59-62

Low density lipoprotein (LDL) was isolated from normal rabbits and was modified with acetic anhydride. Blood monocyte derived macrophages from normal and hypercholesterolemic (HC) rabbits were cultured, and on the 8th day the cells were incubated with native and modified LDL to study their binding and degradation. Macrophages from both normal and hypercholesterolemic rabbits express a limited number of receptors for normal plasma LDL whereas they exhibit a large number of receptors for acetyl LDL. There was no significant difference between binding and degradation of acetyl LDL by normal or hypercholesterolemic cells. However, binding and degradation of native LDL by monocytes of hypercholesterolemic cells were significantly less (p<0.0001) in comparison to binding and degradation of native LDL by normal cells indicating that there is a feedback inhibitory pathway in the cell that inhibits the synthesis of LDL receptors in the presence of excess LDL.  相似文献   

Early detection of prostate cancer: evaluating the diagnostic performance of prostate specific antigen by comparing with histological technique among africans     

Emokpae  M. A.  Das  S. C.  Orok  T.  Mohammed  A. Z.  Hassan  S. A. 《Indian journal of clinical biochemistry : IJCB》2004,19(1):62-66

This study was conducted to investigate the diagnostic performance characteristics of prostate specific antigen (PSA) by comparing serum PSA value with histological findings in patients suspevted of having prostate cancer in Aminu Kano Teaching Hospital. Nigeria. Clinical and Laboratory records were examined and collated for serum PSA values, together with histological findings of biopsy specimen, clinical diagnosis, age of patients, and mode of presentation. The serum PSA values were determined by ELECSYS 1010 autoanalysers Roche, Germany based on electrochemiluminescence immunoassay technique. The results show that serum PSA values increase with age in the assymptomatic non-cancer patients who came for medical check up but were within normal limit. In prostatic disease conditions PSA values were raised in benign prostatic hyperplasia 35.957± 4.0315ng/ml, in undifferentiated carcinoma 56.22±4.295ng/ml and adenocarcinoma >100ng/ml as compared to the normal range (0–4ng/ml). These cases were confirmed by histological diagnosis. It is concluded that PSA evaluations is a sensitive marker for prostate cancer but because of various other conditions that affect serum PSA concentration, other methods of investigations such as Digital Rectal examination, Trans Urethral Ultra-Sonography and histological examination should be combined to confirm diagnosis. Prognosis of patients will be better if early diagnosis is made.  相似文献   

Method Development and Validation of Liquid Chromatography-Tandem Mass Spectrometry for Angiotensin-II in Human Plasma: Application to Study Interaction Between Atorvastatin & Olmesartan Drug Combination     

Rakesh Das  Tapan Kumar Pal 《Indian journal of clinical biochemistry : IJCB》2015,30(3):334-344

Simple and sensitive Liquid Chromatography-Tandem Mass Spectrometry (LCMS/MS) method was developed and validated, then was implicated on hypertensive human subjects to study drug interaction of atorvastatin (ATVS) and Olmesartan (OLM) on status of Angiotensin-II (ANG-II). The ANG-II in plasma was extracted with 5 mL methanol containing 5 % formic acid through C₁₈ (cartridges) liquid–liquid extraction, dried and reconstituted with 1 mL of 16 % acetonitrile in 0.1 % formic acid in water. The chromatographic separation of ANG-II with a Agilent technology 6410 Triple quadrupole was carried multiple reaction monitoring scan mode with a Agilent 1290 Infinity LC system for UHPLC. The sample were separated on a (Thermo Scientific) Hy-Purity advance (50 × 4.6 mm, 5 μm) using Mobile Phase A: 16 % acetonitrile in 0.1 % formic acid in water and Mobile Phase B: 0.1 % formic acid in methanol at a flow rate of 0.3 mL/min, performed at ambient temperature. The mobile phase gradient of 16 % acetonitrile in water was linearly increased to 38 % acetonitrile over 10 min and subsequently the mobile-phase was increased to 100 % acetonitrile over 15 min. The developed method was validated for specificity, accuracy, precision, stability, linearity, sensitivity and recovery. The method was linear between peak area ratio of standard and internal standard over the range of 50–800 ng/mL. The method was successfully applied for the drug interaction study revealed levels of ANG-II were significantly higher in ATVS + OLM treatment condition as compared to individual treatment of OLM. This reflects the reason of low effectiveness of ATVS + OLM in combination instead of synergistic activity.

Electronic supplementary material

The online version of this article (doi:10.1007/s12291-014-0457-x) contains supplementary material, which is available to authorized users.  相似文献   

Comparing age-wise reference intervals for serum creatinine concentration in a “Reality check” of the recommended cut-off     

Mascha Verma  Rashmi Khadapkar  Priyadarshi Soumyaranjan Sahu  Bibhu Ranjan Das 《Indian journal of clinical biochemistry : IJCB》2006,21(2):90-94

An increase in the communication within the healthcare services, both nationally and internationally, has strengthened the need for harmonization of measurements and reference intervals in laboratory medicine. In the present report, the calculated reference interval for serum creatinine (sCr) levels of healthy normal individuals (n=1121) in different sex and age groups are compared with the established interval. The calculated reference interval for sCr level was 0.4–1.3 mg/dL and 0.6 to 1.3 mg/dL in the age groups of 21–40 and 41–60 years respectively. The difference between the mean sCr values in total males and total females (age range 21–60 years) was statistically significant (p<0.0001); When male and female subjects were analyzed age-group wise, the data showed a significant difference in mean sCr values (p<0.0001) in three age groups (21–30, 31–40 and 41–50 years) however, in older age group (51–60 years), the difference was non-significant (p=0.07). The reference ranges were 0.7–1.3 and 0.4–1.0 mg/dL for males and females respectively where the lower limit was 0.1–0.2 units less than that of standard limits. An increase in the mean value of sCr was observed particularly in females with an increase in age. Hence it is of interest to validate an age specific reference ranges for sCr in our population.  相似文献