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Biomedical subjects

M Mukherjee

Publications and source records attributed to M Mukherjee.

At least 19 recordsLinked to original sources
PubMed2006

Effects of garlic oil on postmenopausal osteoporosis using ovariectomized rats: comparison with the effects of lovastatin and 17beta-estradiol.

The purpose of this study was to examine the antiosteoporosis effects of garlic oil in an ovariectomized (Ovx) rat model of osteoporosis and to compare its efficacy with lovastatin (a synthetic hypocholesterolemic drug) and 17beta-estradiol (a potent antiosteoporotic agent). Animals were divided into five groups: sham-operated control, ovariectomized, ovariectomized supplemented with lovastatin, ovariectomized supplemented with garlic oil and ovariectomized supplemented with 17beta-estradiol. In our study, the development of a high rate of bone turnover and osteoporosis in the ovariectomized animals were confirmed by significant alterations of serum alkaline phosphatase activity, serum tartrate-resistant acid phosphatase activity, urinary excretion of calcium, phosphate, hydroxyproline and urinary calcium to creatinine ratio, when compared with the sham-operated control group. Supplementation of these animals with either garlic oil or lovastatin or 17beta-estradiol, in addition to their hypocholesterolemic effect, could counterbalance all these changes. The results revealed that all three compounds significantly protected the hypogonadal bone loss as reflected by higher bone densities and higher bone mineral contents than the ovariectomized group of animals. The results emphasize that, like 17beta-estradiol, the hypocholesterolemic compounds garlic oil and lovastatin are also effective in suppressing bone loss owing to estrogen deficiency and their efficacy in the order of lower to higher is garlic < lovastatin < 17beta-estradiol.

Acid Phosphatase↗
PubMed2006

Limitation of glucose oxidase method of glucose estimation in jaundiced neonates.

The most widely used method for estimation of plasma glucose is that adopted by Trinder's using glucose oxidase-peroxidase (GOD-POD) system. This method gives much lower blood glucose values with blood samples of neonatal jaundice (plasma bilirubin level > 10 mg/dL) of age 10 +/- 5 daysthan with samples of neonates of the same age group without jaundice or older children suffering from other diseases like acute respiratory distress, septicemia.

Glucose↗
PubMed2004

Discrete film thickness in polyacrylamide-CdS nanocomposite ultrathin films.

A nanocomposite of polyacrylamide, a water soluble polymer, and nanocrystalline CdS has been prepared using a chemical route. Transmission electron microscope observation shows that the particles are attached via the polymer coils. The reduction of viscosity for the composite, despite the increase in concentration, indicates a reduction of interchain entanglement between the composite coils. Ultrathin films were prepared from the nanocomposite and pure polyacrylamide using spin coating on a Si(100) substrate in the speed range of 500 to 5000 rpm. X-ray reflectivity studies of the pure polymer and composite films were carried out in vacuum. The thickness of the composite films varies nonmonotonically with spinning speed and is found to lie in discrete "bands" of thickness separated by "forbidden regions." The power law behavior of the thickness with the spinning speed was also found to be different for the composite films in comparison to the polymer ones. A model has been proposed in terms of discrete numbers of layers composed of CdS-attached polymer coils to explain the phenomena.

Journal Article↗
PubMed2004

The mass of 22Mg.

Mass measurements with a relative precision of better than 1.5 x 10(-8) were performed on 22Mg and its reaction partners 21Na and 22Na with the ISOLTRAP Penning trap mass spectrometer at CERN, yielding the mass excesses D(22Mg)=-399.92(27) keV, D(21Na)=-2184.71(21) keV, and D(22Na)=-5181.56(16) keV. The importance of these results is twofold. First, a comparative half-life (Ft value) has been obtained for the superallowed beta decay of 22Mg to further test the conserved-vector-current hypothesis. Second, the resonance energy for the 21Na proton capture reaction has been independently determined, allowing direct comparisons of observable gamma radiation in nova explosions with the yield expected from models.

Journal Article↗
PubMed2004

Prevention of bone loss by oil extract of garlic (Allium sativum Linn.) in an ovariectomized rat model of osteoporosis.

The effects of oil extract of garlic (Allium sativum Linn.) on different primary and secondary osteoporotic marker changes were tested in an ovariectomized rat model of osteoporosis. Experiments were performed on three different rat models: sham-operated control, ovariectomized and ovariectomized supplemented with garlic oil. In ovariectomized group, there has been a significant increase in different relative organ weights compared to sham-operated control, while the uterine weight was found to be decreased. Supplementation with oil extract of garlic could effectively reverse these changes. Also low bone densities that developed in the ovariectomized group were significantly recovered in the garlic oil supplemented group. In our study, the development of high rate of bone turnover and osteoporosis in the ovariectomized animals were confirmed by significant alteration of serum alkaline phosphatase activity, serum tartrate resistant acid phosphatase activity, urinary excretion of calcium, phosphate, hydroxyproline and urinary calcium to creatinine ratio, when compared with the sham-operated control group. Garlic oil extract supplementation, apart from its unique influence in lowering blood cholesterol, could also prevent ovariectomy-induced rise in all the above-mentioned marker changes. The results of this study emphasize that oil extract of garlic possibly has a positive role in suppressing ovariectomy-induced bone resorption.

Alkaline Phosphatase↗
PubMed2004

Variations in high-density lipoprotein cholesterol in relation to physical activity and Taq 1B polymorphism of the cholesteryl ester transfer protein gene.

The aim of the study was to determine any association of physical activity and Taq 1B polymorphism in the cholesteryl ester transfer protein gene on high-density lipoprotein (HDL) cholesterol. Five hundred and four subjects, 390 males and 114 females consisting of an equal number of age- and sex-matched healthy controls and patients with coronary artery disease, were included. The mean age (+/-SD) of the patients and controls were 57.5 +/- 10.6 years and 56.8 +/- 11.0 years, respectively. All the patients underwent coronary angiography; 33, 58, 63, and 98 patients had normal coronaries, single-, two-, or triple-vessel disease, respectively. A third of the patients had suffered from a myocardial infarction. The genotype distribution conforming to Hardy-Weinberg equilibrium was similar for cases and controls. The mean HDL cholesterol increased from B1B1 through B2B2 genotype in controls and sedentary male patients. Self-reported leisure time physical activity, consisting mostly of an hour of morning walk daily, was associated with a rise in mean HDL cholesterol in male controls (33.6 +/- 7.9 mg/dl to 36.2 +/- 8.9 mg/dl, p = 0.037) and patients (32.4 +/- 7.9 mg/dl to 35.7 +/- 11.0 mg/dl; p = 0.018). The exercise-associated rise in HDL cholesterol was most pronounced in controls (32.1 +/- 9.1 mg/dl to 36.8 +/- 9.3 mg/dl, p = 0.05) and male patients (30.5 +/- 7.4 mg/dl to 37.2 +/- 9.7 mg/dl, p = 0.007) with B1B1 rather than B1B2 or B2B2 genotype. The results suggest a possible gene-environment interaction in the regulation of HDL cholesterol that needs to be confirmed in other populations and larger samples to rule out a chance occurrence.

Adult↗
PubMed2003

Homologous expression of a mutated beta-tubulin gene does not confer benomyl resistance on Trichoderma virens.

AIMS: To clone the beta-tubulins and to induce resistance to benzimidazoles in the biocontrol fungus Trichoderma virens through site-directed mutagenesis. METHODS AND RESULTS: Two beta-tubulin genes have been cloned using PCR amplification followed by the screening of a T. virens cDNA library. The full-length cDNA clones, coding for 445 and 446 amino acids, have been designated as T. virens tub1 and T. virens tub2. A sequence alignment of these two tubulins with tubulins from other filamentous fungi has shown the presence of some unique amino acid sequences not found in those positions in other beta-tubulins. Constitutive expression of the tub2 gene with a histidine to tyrosine substitution at position 6 (known to impart benomyl/methyl benzimadazol-2-yl carbamate resistance in other fungi), under the Pgpd promoter of Aspergillus nidulans, did not impart resistance to benomyl. CONCLUSIONS: The homologous expression of tub2 gene with a histidine to tyrosine mutation at position +6, which is known to impart benomyl tolerance in other fungi, does not impart resistance in T. virens. SIGNIFICANCE AND IMPACT OF THE STUDY: Unlike other Trichoderma spp., T. virens, has been difficult to mutate for benomyl tolerance. The present study, through site-directed mutagenesis, shows that a mutation known to impart benomyl tolerance in T. viride and other fungi does not impart resistance in this fungus. Understanding the mechanisms of this phenomenon will have a profound impact in plant-disease management, as many plant pathogenic fungi develop resistance to this group of fungicides forcing its withdrawal after a short period of use.

Amino Acid Sequence↗
PubMed2003

Re-evaluation of reading frame-shift hypothesis in Duchenne and Becker muscular dystrophy.

The reading frame hypothesis has been proposed to explain the molecular basis of two allelic forms of muscular dystrophies, Duchenne/Becker muscular dystrophy (D/BMD). To evaluate the hypothesis in Indian D/BMD patients, we analyzed deletion of dystrophin exons in 147 DMD and 19 BMD patients. Our studies showed deviation of more than 30% from the reading frame hypothesis in DMD patients (47/147). The present results implicate a need to reevaluate the reading frame hypothesis.

Child↗
PubMed2003

Diagnostic evaluation of extrapulmonary tuberculosis by fine needle aspiraton (FNA) supplemented with AFB smear and culture.

One hundred forty-three patients, 72 males and 71 females, with extrapulmonary tuberculosis were aspirated and subjected to cytological (Ziehl-Neelsen stain) examination and culture in Lowenstein-Jensen media. Routine haematological examination and Mantoux test were done in all the cases, x-ray chest in 112, skeletal x-ray in 3 relevant cases and sputum was examined for AFB in 16 cases where pulmonary tuberculosis was associated/suspected with extrapulmonary tuberculosis. HIV status was evaluated in 51 cases and 9 (7.64%) were seropositive. FNA cytology in 102 cases (71.3%) had caseating epithelioid granulomas while smear for AFB was positive in 57 cases (39.8%). Both culture and smear were positive in 29 (20.2%) cases. Combining both smear and culture yielded positive results in 47.5% cases. It was observed that AFB positivity was higher in untreated patients and with HIV positive cases. Further more, the triad of FNAC, AFB smear and culture were cheaper, foolproof and confirmatory than costlier tests like TB IgG, IgM, RTPCR and BACTEC.

Adolescent↗
PubMed2002

Reversible negative thermal expansion of polymer films.

A basic understanding of the properties of thin polymer films is of fundamental importance for developing applications in nanotechnology. Results of energy and angle dispersive x-ray reflectivity measurements on polymer thin films as a function of temperature exhibit reversible negative thermal expansion below the glass transition temperature T(g). Above T(g), the thickness expansion becomes almost equal to the expected bulk volume expansion. These results could be explained on the basis of evolution of disorder with temperature at the interfaces, chain entanglement and associated entropy changes.

Journal Article↗
PubMed2002

Role of Oxalobacter formigenes in calcium oxalate stone disease: a study from North India.

OBJECTIVE: The present study was performed to detect the presence of an oxalate degrading bacteria Oxalobacter formigenes in the GI tract of calcium oxalate stone patients and normal individuals from North India. Furthermore, the possible relationship of this bacterium with number of stone episodes in this part of the world was also studied. The correlation of the presence or absence of O. formigenes with the urinary oxalate levels was evaluated. METHODS: DNA was extracted from the stool samples of 63 calcium oxalate stone formers and 40 normal individuals. Polymerase chain reaction (PCR) was performed using genus specific primers for O. formigenes. The presence of which was confirmed by Southern blotting. Urinary oxalate levels were tested in each patient. RESULTS: As shown by PCR and Southern blotting, O. formigenes was present in 65% of normal individuals and in 30% of calcium oxalate stone formers. In patients with three or greater than three stone episodes colonies were present only in 5.6% of patients. Oxalate excretion was less in patients colonized with O. formigenes as compared to those with no colonization. CONCLUSION: In North Indian population the absence of O. formigenes can lead to a significant increase in the risk of absorptive hyperoxaluria and resultant recurrent calcium oxalate stone episodes.

Adolescent↗
PubMed2002

A low prevalence of the C677T mutation in the methylenetetrahydrofolate reductase gene in Asian Indians.

The prevalence of the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene in Asian Indians from India was determined and the association of the mutant allele with coronary artery disease (CAD) was evaluated in a case-control study. The case group consisted of 251 patients with CAD; 195 male and 56 female aged from 29 to 82 years (mean age +/- SD, 57.5 +/- 10.6 years). The control group consisted of 216 apparently healthy individuals without evidence of CAD; 161 male and 55 female aged from 30 to 83 years (mean age +/- SD, 54.9 +/- 10.4 years). All the patients were assessed by coronary angiography. While 33 patients had normal coronaries, 23, 25 and 39 patients had single-vessel, two-vessel and triple-vessel disease, respectively. Eighty-three patients (33%) had suffered myocardial infarction less than a year to five years earlier. The C677T polymorphism in the MTHFR gene was assessed. While 31% of the controls and 38% of the patients had the heterozygous genotype, 2% of the control group and none of the patients had the mutant homozygous genotype. The overall 'T' allelic frequencies were comparable in control and patient groups (0.18 and 0.19, respectively), but the association of the sum of heterozygous and homozygous genotypes with CAD (1, 2 or 3-vessel disease) was statistically significant for females only [Odds ratio (95% confidence intervals), 2.8 (1.1-6.9), p = 0.023]. No association was found between genotype distribution and previous myocardial infarction or severity of atherosclerosis.

Adult↗
PubMed2001

Point mutation and polymorphism in Duchenne/Becker muscular dystrophy (D/BMD) patients.

Duchenne and Becker muscular dystrophies (D/BMD) are caused by mutations in the dystrophin gene. Two-thirds of patients have large intragenic deletions or duplications and the remaining one-third have point mutations, small deletions or insertions. Point mutations are more difficult to detect due to the enormous size (2.4 Mb) of the gene and its large transcript (14 kb). In the present study, a total of 50 DNA samples from unrelated D/BMD (38 DMD and 12 BMD) patients who did not show intragenic deletions by multiplex PCR, were analyzed for detection of point mutations. Single stranded conformation analysis and heteroduplex analysis observed electrophoretic mobility shifts in one (BMD) and two (DMD and BMD) patients, respectively. The mobility shift and heteroduplexes were observed in exon 17 in all of the three patients. Sequencing of the amplified PCR products revealed a nucleotide change (-37 g to t) in the intronic region in two of the patients while a C2268T substitution in the exonic region in one. Mutation database search for D/BMD mutations showed the nucleotide substitution in the exonic region as a novel change in the human dystrophin gene, which was not reported earlier. It resulted in an amino acid transition from threonine to methionine in the 687th position of the dystrophin protein. This novel substitution has been included in the mutation database of Leiden muscular dystrophy pages (http://www.dmd.nl) in the rare polymorphism/mutation category. The substituted nucleotide segregated with the disease phenotype in the family suggesting that it can be directly used for carrier detection and prenatal diagnosis without identification of disease causing mutation.

Amino Acid Sequence↗
PubMed2001

Effects of the cannabinoid receptor antagonist SR 141716, alone and in combination with dexfenfluramine or naloxone, on food intake in rats.

RATIONALE: Recent studies in animals have implicated endogenous cannabinoids in the regulation of palatable food intake, but it is not yet clear to what extent pharmacological agents acting on this system may have sustained actions and applicability to different feeding protocols. OBJECTIVES: In the present study, we examine the effects of the cannabinoid CB1 receptor antagonist SR 141716 on food intake of rats, and its behavioral specificity. We examine whether tolerance develops to the anorectic actions of SR 141716, and whether it has either additive or synergistic actions with dexfenfluramine or naloxone. METHODS: Undeprived rats were trained to eat a daily sweet milk dessert and on test days were administered single or combination drugs and intakes were recorded. In other studies, rats were deprived for 24 h of either food or water and intakes recorded after drug administration at the end of this time. In one study, rats were fed ad libitum chow with SR 141716 added. RESULTS: SR 141716 (1-3 mg/kg) suppressed both palatable food intake in undeprived rats and food, but not water, intake after deprivation. Using an isobolographic analysis, SR 141716 had an additive anorectic effect with dexfenfluramine. In contrast, SR 141716 in combination with naloxone had a significantly supra-additive anorectic action. SR 141716 was also effective orally and no tolerance to its anorectic effect developed over 3 days. CONCLUSIONS: These data show that SR 141716 is an effective anorectic agent using both palatable foods and bland chow, and is selective because water intake was unaffected. SR 141716 is also effective orally and has an effect sustained for at least several days. There appears to be a synergistic interaction between opioid and cannabinoid systems in the regulation of feeding, whereas the combination of a serotonin releasing agent and the CB1 antagonist is additive.

Animals↗
PubMed2001

A direct-method ab initio phasing of a protein, cupredoxin amicyanin, at 1.31 A resolution.

The direct-methods program MULTAN88 has been applied successfully to redetermine the structure of a protein, cupredoxin amicyanin, containing 808 non-H atom sites, one Cu atom and 132 ordered water molecules in the asymmetric unit using data at 1.31 A resolution. Starting with initially random phases, useful phase sets selected by figures of merit could be obtained from multiple trials. The E maps corresponding to the best eight phase sets in order of combined figures of merit (CFOM2) revealed a distorted tetrahedral geometry around the Cu site. The phase estimates from the metal and a few neighbouring atoms in the initial E map corresponding to the set with the highest CFOM2 could be improved by the density-modification procedure PERP and led to an interpretable electron-density map.

Azurin↗