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Biomedical subjects

B Mukherjee

Publications and source records attributed to B Mukherjee.

At least 19 recordsLinked to original sources
PubMed2006

A case of sensorineural deafness following ingestion of sildenafil.

We report a case of bilateral profound unremitting sensorineural hearing loss, in a 44-year-old male patient occurring after ingestion of sildenafil citrate 50 mg/day for 15 days. Audiological evaluation documented the findings. Sildenafil is an effective oral treatment for erectile dysfunction syndrome. It is being used and abused by many people as availability is easy and it can even be bought over the internet. Many patients are unaware of the harmful effects of sildenafil and take the drug without medical supervision. We could not find any previously reported cases of sildenafil induced hearing loss and to the best of our knowledge, this is the first case report of sildenafil induced sensorineural hearing loss in the world literature.

Adult↗
PubMed2006

HPLC detection of plasma concentrations of diclofenac in human volunteers administered with povidone-ethylcellulose-based experimental transdermal matrix-type patches.

By developing a high-performance liquid chromatography (HPLC) method, we estimated the blood concentrations of diclofenac in human volunteers administered with the transdermal patches prepared with povidone-ethylcellulose and oral diclofenac tablets. Drug-excipient interaction studies were done using the FTIR technique. The external morphology of the prepared patch before and after application to human skin was analyzed with scanning electron microscopy. FTIR studies revealed that there was no predominant interaction between the drug and polymers. In vivo studies revealed that the average concentrations of drug in plasma were 376, 1562, 2953, 2902, 2864, and 2948 ng/ml after 2, 4, 8, 24, 30, and 48 h from patches each containing 50 mg of diclofenac diethylamine, respectively, and the mean concentrations of drug in plasma after the oral administration of marketed tablet containing 50 mg diclofenac sodium were 383.7, 2569, 3693.5, 162.5, and 55.3 ng/ml at 2, 4, 8, 24, and 30 h after oral administration. Values of Cmax were 3693.5 after oral administration and 2953.8 ng/ml in the case of transdermal application. From this study, we have achieved the sustained blood level of diclofenac from the experimental patches along with an analytical method based on HPLC to determine the diclofenac blood level.

Administration, Cutaneous↗
PubMed2005

A predictive model for cesarean section in low risk pregnancies.

OBJECTIVE: A small number of women with low risk pregnancies undergo cesarean section. A model that can predict this risk and therefore identify these women will be of help in several hospitals where personnel and resources are limited. METHODS: The study consisted of 2 parts. All charts of women with low risk singleton pregnancies admitted to labor room over a 5-month period were analyzed. Adjusted odds ratios were calculated to find out relative importance of each risk factor and likelihood ratios were obtained. These were prospectively applied to 1010 consecutive low risk women and the post test probability calculated. Finally the actual incidence of cesarean section was compared with posttest probability derived from predictors. RESULTS: A combination of maternal age >24 years, primiparity and height <150 cm or a combination of any 2 of the 3 variables is significantly associated with increased cesarean section rate. Individually, primiparity, height <150 cm or age >24 years also significantly increased the chances of cesarean section. CONCLUSIONS: A predictive model consisting of maternal age, parity and height can be used to identify low risk pregnant women who are likely to require cesarean section.

Adult↗
PubMed2004

Serosurveillance for Japanese encephalitis in children in several districts of West Bengal, India.

AIM: To evaluate the prevalence of antibodies to flaviviruses, particularly Japanese encephalitis (JE) in children. METHODS: Virological and serological investigations were conducted into JE, along with dengue 2 (Den2) and West Nile viruses, in the Flavivirus group. The paediatric age group (up to 10 y), in the districts of Burdwan, Bankura, Midnapore and Purulia of West Bengal, India, was assessed for recent activity of these viruses, for 4 consecutive years from 1996 to 1999. In total, 2260 sera samples were collected, of which 204 were from acute fever cases; only 72 paired sera were available. There was a significantly higher incidence of fever cases in children belonging to the schedule caste and schedule tribes. These communities occupy the lowest level in the society and are closely associated with pigs. RESULTS: No virus could be isolated from the sera collected from fever cases. The results of the serological survey showed the presence of antibodies to JE virus in only 13.3% of the contact sera, 33.3% of acute sera and 22.1% of convalescent sera investigated. Only 3.1% of the contact sera had antibodies to Den2 and no antibodies were found against West Nile virus. This indicates that the JE virus is in recent circulation in the population of these four districts, and as the majority of children lack substantial immunity to JE virus, they may be affected by an epidemic. CONCLUSION: Children up to 10 y of age in the four districts of West Bengal are mostly non-immune to JE virus. If an outbreak occurs, the majority of these populations may be affected.

Antibodies, Viral↗
PubMed2003

A new flavonoid from Limnophila rugosa.

A minor flavonoid constituent of Limnophila rugosa has been isolated from its petrol extract and identified as 5,7-dihydroxy-8,3',5'-trimethoxyflavone (1).

Flavonoids↗
PubMed2003

Screening of antioxidant activity of three Indian medicinal plants, traditionally used for the management of neurodegenerative diseases.

A number of Indian medicinal plants have been used for thousands of years in the traditional system of medicine (Ayurveda). Amongst these are plants used for the management of neurodegenerative diseases such as Parkinson's, Alzheimer's, loss of memory, degeneration of nerves and other neuronal disorders by the Ayurvedic practitioners. Though the etiology of neurodegenerative diseases remains enigmatic, there is evidence, which indicates that defective energy metabolism, excitotoxicity and oxidative damage may be crucial factors (Ann. Neurol. 38 (3) (1995) 357). The part of the Ayurvedic system that provides an approach to prevention and treatment of degenerative diseases is known as Rasayana, and plants used for this purpose are classed as rejuvenators. This group of plants generally possesses strong antioxidant activity (Pharmacol. Biochem. Behav. 43 (1992) 1175), but only a few have been investigated in detail. In the present study, three such rasayana plants were tested for the first time for their toxicity and free radical scavenging activity both in vitro and ex vivo. All the three plant infusions (up to 1 mg/ml) showed no toxic effects on the viability of PC12 cell line as judged by MTT-test. Both ethanolic extracts and water infusions of the plants were tested for their antioxidant activity in the 2,2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS*(+)) radical cation decolorization assay; inhibition of lipid peroxidation by plant infusions was carried out using spontaneous lipid peroxidation of rat brain homogenate, and IC50 values were determined. The results from the ABTS assay showed that the ethanolic extract of Sida cordifolia was found to be most potent (IC50 16.07 microg/ml), followed by Evolvulus alsinoides (IC50 33.39 microg/ml) and Cynodon dactylon (IC50 78.62 microg/ml). The relative antioxidant capacity for the water infusions was observed in the following order: E. alsinoides (IC50 172.25 microg/ml)>C. dactylon (IC50 273.64 microg/ml)>S. cordifolia (IC50 342.82 microg/ml). The results of water infusions of the plants on lipid peroxidation were as follows: E. alsinoides (IC50 89.23 microg/ml)>S. cordifolia) (IC50 126.78 microg/ml)>C. dactylon (IC50 608.31 microg/ml).

Animals↗
PubMed2002

Evaluation of chemical constituents and free-radical scavenging activity of Swarnabhasma (gold ash), an ayurvedic drug.

From ancient times, Swarnabhasma (gold ash) has been used in several clinical manifestations including loss of memory, defective eyesight, infertility, overall body weakness and incidence of early aging. Swarnabhasma has been used by Ayurvedic physicians to treat different diseases like bronchial asthma, rheumatoid arthritis, diabetes mellitus, nervous disorders, etc. In the present investigation, Swarnabhasma was prepared after proper purification and calcination as per Ayurvedic pharmacy which consisted of Realger (As(2)S(2)), Lead oxide (Pb(3)O(4)), Pure gold (Au) and Latex of Calotropis gigantea. Qualitative analyses indicated that Swarnabhasma contained not only gold but also several microelements (Fe, Al, Cu, Zn, Co, Mg, Ca, As, Pb, etc.). Infrared spectroscopy showed that the material was free from any organic compound. The metal content in the bhasma was determined by atomic absorption spectrometry. Acute oral administration of Swarnabhasma showed no mortality in mice (up to 1 ml /20 g b.w. of Swarnabhasma suspension containing 1mg of drug). Chronic administration of Swarnabhasma also showed no toxicity as judged by SGPT, SGOT, serum creatinine and serum urea level and histological studies. In an experimental animal model, chronic Swarnabhasma-treated animals showed significantly increased superoxide dismutase and catalase activity, two enzymes that reduce free radical concentrations in the body.

Animals↗
PubMed2002

Measurement of the neutron and gamma doses accumulated during commercial jet flights from sydney to several major destinations in the northern and southern hemispheres.

As recommended by the ICRP, the European Union (EU) agreed to abide by mandatory monitoring of radiation doses to crew during civil aviation flights operated by the airlines of the EU member states. A large number of measured and theoretically predicted values for the in-flight radiation doses of northern hemisphere flight routes are available. On the other hand very few data have been published for the southern hemisphere. This paper will present the results of Australian domestic and intemational return flight routes originating from Sydney. The paper also presents results of trans-hemisphere air traffic routes. Neutron and gamma doses were measured using superheated bubble dosemeters and semiconductor detectors respectively. Based on our measurements a method is suggested whereby aircrew may share their personal radiation burden by flight crew hemisphere exchange.

Aerospace Medicine↗
PubMed2002

Relative thermoluminescence efficiency of TLD-600 and TLD-700 dosemeters irradiated with 59.8 MeV per nucleon krypton-86 ions.

A batch of LiF thermoluminescence dosemeters (TLDs), each containing five TLD-600 and TLD-700 thermoluminescence dosemeter chips, was irradiated with 59.85 MeV per nucleon 86Kr20+ ions from the K1200 superconducting cyclotron at the National Superconducting Cyclotron Laboratory (NSCL). Michigan State University, USA. The average linear energy transfer of the accelerated 86Kr ions and the resulting dose imparted to the TLD chips were calculated to be 3343 keV.microm(-1) per ion and 1.68 Gy respectively. A similar batch of TLD chips was irradiated with 1.3 MeV gamma rays from a 60Co source to 1.0 Gy. The TLD chips were evaluated at a ramp heating rate of 10 degrees C.s(-1) to 400 degrees C using a hot-finger type TLD reader. The thermoluminescence efficiency of the TLD-600 and TLD-700 dosemeters, relative to 60Co gamma rays was calculated to be 0.0025 and 0.0027 respectively

Fluorides↗
PubMed2001

Detection of pharmacologically mediated changes in cerebral activity by functional magnetic resonance imaging: the effects of sulpiride in the brain of the anaesthetised rat.

Blood oxygenation level dependent (BOLD) contrast functional magnetic resonance imaging (fMRI) was used to study the effects of the D(2)-like receptor selective antagonist, sulpiride, at 2 Tesla in the brain of the alpha-chloralose anaesthetised rat. Region of interest (ROI) analysis indicated significant (P<0.05) bilateral increases in BOLD signal intensity in the frontal cortex following a single administration of sulpiride (10 mg/kg i.v.). BOLD signal changes were slow in onset and increased gradually during the experiment, reaching 8.0+/-0.5% (mean+/-S.E.M.) above pre-injection control values 165 min after drug administration. Signal increases remained high at the experiment end (3 h post sulpiride administration). Sulpiride (30 mg/kg i.v.) had a similar effect in the frontal cortex, increasing signal 5.2+/-1.8% above control values by 174 min; its effects were, however, more variable between rats, and were not statistically significant. Sulpiride (3 mg/kg i.v.) had no significant effect upon BOLD signal intensity in any brain region. No dose of sulpiride resulted in any significant BOLD signal changes in the striatum or cerebellum. These data are supportive of the notion that sulpiride causes an increase in frontal dopaminergic function by antagonism of presynaptically located dopamine D(2) receptors in this brain region, consistent with its therapeutic action. Furthermore, the utility of BOLD contrast fMRI as a means of detecting changes in neuronal activity contingent upon the administration of a psychoactive pharmacological agent has been demonstrated.

Animals↗
PubMed2001

Mapping of brain activation in response to pharmacological agents using fMRI in the rat.

Functional MRI (fMRI) was used to investigate the effects of psychotropic compound activity in the rat brain in vivo. The effects of dizocilpine (MK-801) an N-methyl-D-aspartate receptor antagonist and m-chlorophenylpiperazine (mCPP), a 5-HT(2b/2c)-receptor agonist on rat brain activity were investigated over a time interval of about 1 h and the results were compared to published glucose utilisation and cerebral blood flow data. Signal magnitude increases were observed predominantly in limbic regions following MK-801 administration (0.5 mg/kg i.v) whereas signal decreases were restricted to neocortical areas; a characteristic, time dependent pattern of regional changes evolved from the thalamic nuclei to cortical regions. In contrast, mCPP (25 mg/kg i.p) produced gradual signal intensity increases in limbic and motor regions with signal decreases restricted to the visual, parietal and motor cortices. The results from both compounds show remarkable similarity with autoradiographic measurements of cerebral blood flow and glucose uptake. These experiments suggest that the spatio-temporal capabilities of fMRI may be applied to the in vivo investigation of psychoactive compound activity with potential for clinical applications.

Animals↗
PubMed2001

Effect of selenomethionine on N-methylnitronitrosoguanidine-induced colonic aberrant crypt foci in rats.

An association between low selenium intake and the incidence or prevalence of cancers is well known. Selenium in the form of selenomethionine supplemented in drinking water has been found to be highly effective in reducing tumour incidence and preneoplastic foci during the development of hepatocarcinogenesis in rats in our previous studies. Here, an attempt has been made to investigate whether the dose and form of selenium found to be effective during hepatocarcinogenesis is equally effective in N-methylnitronitrosoguanidine-induced colorectal carcinogenesis in terms of antioxidant defence enzyme systems, DNA chain breaks and incidences of aberrant crypt foci. Treatment with selenomethionine either on initiation or on selection/promotion, or during the entire experiment showed that selenomethionine was most effective in regulating the cellular antioxidant defence systems, DNA chain break control and reducing aberrant crypt foci in the colorectal tissues of rats. Our results also confirm that selenium is particularly effective in limiting the action of the carcinogen during the initiation phase of this colorectal carcinogenesis, just as we found with hepatocarcinogenesis in our previous studies.

Animals↗
PubMed2001

Wound healing activity of human placental extracts in rats.

AIM: To study wound healing activity of the human placental extract (HPE) in rats. METHODS: Full thickness wounds were inflicted on depilated dorsum of Charles foster rats with 8 mm Acu-punch biopsy. The HPE was applied both at topical and im routes (2.5 mL/kg). Effects were compared on the basis of physical criteria, biochemical criteria, and histopathological study with respect to untreated control, vehicle control (1.5 % benzyl alcohol), and framycetin topical treated groups. RESULTS: Significant lowering of wound size (P<0.05), wound index (P<0.05), and number of days required for complete healing (P<0.01); significant gain in tensile strength (P<0.01); appreciable increase of tissue DNA, total protein, and collagenesis were observed in HPE treated group. CONCLUSION: Human placental extract systematically helps collagenesis leading to potent healing of wounds.

Animals↗
PubMed2000

An unusual seven-bond H-H spin coupling

A through-space, seven-bond (1)H-(1)H coupling has been observed in tiliacorinine (1) caused by the close spacial proximity of two aromatic protons that are located in different benzene rings which are separated by two sp(3) carbons. Results from DQF-COSY and NOESY NMR experiments, as well as molecular modeling, reveal that the two protons are unusually close to one another in space.

Journal Article↗
PubMed2000

On-demand electrochemical release of DNA from gold surfaces.

Electrochemical quartz crystal microbalance (EQCM) is used to probe the electrochemically triggered release of nucleic acids from gold surfaces to solutions of physiological pH. The immobilization of nonthiolated DNA onto the gold surface is followed by an electrostatic desorption at -1.0 V (vs. Ag/AgCl). Steady-state frequency signals, corresponding to the removal of 261- and 644-ng/cm2 single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA), respectively, were attained within 75 and 330 s. As expected for electrostatic repulsion, the amount released can be manipulated by tuning the potential. The small nonsteady-state frequency signals observed at lower potentials indicate promise for a sustained DNA release. Applicability to gold ultramicroelectrodes (12.5-microm radius) is demonstrated in connection with voltammetric blocking experiments. We expect that such on-demand electrochemical release would be a useful addition to the arsenal of nonviral gene delivery routes.

DNA↗
PubMed2000

Mapping of the cerebral response to hypoxia measured using graded asymmetric spin echo EPI.

Graded asymmetric spin echo-echo planar imaging (ASE-EPI) was used to measure transient alterations in cerebral oxygenation resulting from 60 seconds of anoxia in alpha-chloralose anaesthetised rats. The anoxic period induced a transient fall ( approximately 1 min) in signal intensity followed by a prolonged signal overshoot consistent with an autoregulatory response to oxygen deprivation. The magnitude of signal response, integrated over the entire brain, increased linearly with the echo asymmetry (t(ge)). However, that increase in sensitivity was offset by a reduced signal to noise ratio and quality of the image data. The responses of four regions of interest within the brain to the anoxic stimulus, and the effect of increasing the echo asymmetry, were compared. A comparable magnitude of signal decrease was observed in all brain regions except the superficial cortex that included pial vessels. As t(ge) was incremented differences in signal attenuation between regions became more pronounced. The signal overshoot observed upon restoration of normal breathing gases showed similar trends, producing similar normalised vascular responses for all regions of interest studied. Different regions of interest showed comparable time courses of the signal overshoot suggesting that similar autoregulatory vascular mechanisms operate in all brain regions. These findings additionally show that the use of graded ASE-EPI produced a characteristic profile of maximum signal change measured during and following the anoxic period for each brain region. They suggest that the shape of this profile was determined by the local vasculature within each region of interest; this feature could be exploited in activation studies to eliminate regions with significant signal changes originating from large draining vessels. Finally, the consistent physiological response observed, when the overshoot was compared to the magnitude of the signal drop, demonstrated that modification of the spin echo offset parameter did not mask or detrimentally alter the signal change resulting from the underlying physiological perturbation.

Animals↗
PubMed1999

Chemical and pharmacological evaluation of different ayurvedic preparations of iron.

Ayurvedic preparations of metallic iron commonly categorised as different 'putas' of 'Louha Bhasma' was chemically analysed and pharmacologically investigated in iron deficiency anemia. Atomic absorption spectral (AAS) study of different putas of Louha Bhasma revealed the presence of various proportions of important metals along with varied concentration of iron in it. The effect of a representative puta viz. 50 puta of Louha Bhasma in the management of agar gel diet and phlebotomy induced iron deficiency anemia in animal model was found to be statistically highly significant (P < 0.001) in comparison to the control and standard drug Fefol treated groups.

Anemia, Iron-Deficiency↗