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Biomedical subjects

S K Das

Publications and source records attributed to S K Das.

At least 37 records · Page 2Linked to original sources
PubMed2005

Involuntary jerking of lower half of the body (spinal myoclonus).

A 55 years old, hypertensive, diabetic lady presented with sudden onset jerky movement of lower trunk and legs. It was present both in awake and sleep and got aggravated by mental stress as well as sensory stimulation. Examination revealed rhythmic jerks affecting muscles of lower abdomen and legs. The lower limbs had normal muscle bulk and power, increased tone, exaggerated deep tendon reflexes, bilateral flexor plantar response with normal sensory autonomic and cerebellar function. Investigations including CSF study, MRI of dorsal spine and NCV were normal. A combination therapy with tizanidine, baclofen and clonazepam induced gradual improvement within 6 weeks.

Baclofen↗
PubMed2005

Bilateral intracerebral haemorrhages: an atypical presentation of Japanese encephalitis.

Japanese encephalitis is common human endemic encephalitis seen over various parts of the world. Usual presenting features include an encephalitic syndrome, symptoms of frontal lobe, basal ganglia and thalamic involvement. Characteristic radiological picture is bilateral thalamic and basal ganglia hypo density in the CT scan and hypo-intensity in T1 and hyperintensity in T2 weighted image in MRI. Very rarely occurrence of bilateral hemorrhage may be seen in these regions. This radiological change may be early indicator of the disease before serological confirmation by the available diagnostic modalities. In this communication, we have reported a case of Japanese encephalitis presented with bilateral basal ganglia hemorrhages.

Adult↗
PubMed2005

A new method for isolation of leukocytes from the peripheral blood of amphibians [Bufo himalayanus, (Gunther)] and study of their surface morphology by scanning electron microscopy.

Using percoll as the density gradient, a new single step method to isolate leukocytes from the peripheral blood of amphibians (B. himalayanus) has been described. Isolated leukocytes were photographed under the scanning electron microscope and an attempt has been made to characterize the leukocyte population on the basis of surface morphology. Apart from regular blood cell types, B. himalayanus have slender, elongated and slightly curved leukocyte type cells in their peripheral blood. Such slender elongated cells were absent in the blood of a related species B. stomnaticus and hence could not be categorized under the known blood cell types.

Animals↗
PubMed2004

Natural radioactivity and radiation exposure in the high background area at Chhatrapur beach placer deposit of Orissa, India.

A high natural background radiation area is reported for the Chhatrapur beach placer deposit of Orissa state, on the southeastern coast of India, due to the presence of radiogenic heavy minerals. The average activity concentrations of radioactive elements 232Th, 238U and 40K were measured by gamma-ray spectrometry using a HPGe detector, and found to be 2500 +/-1850, 230 +/- 140 and 120 +/- 35 Bq kg-1, respectively, for the bulk sand samples. The absorbed gamma dose rates in air due to the naturally occurring radionuclides varied from 375 to 5000 nGy h-1, with an average value of 1625 +/- 1200 nGy h-1. The external annual effective dose rate of the region ranged from 0.46 to 6.12 mSv y-1, with an average value of 1625 +/- 1200 mSv y-1. The absorbed gamma dose rate levels of Chhatrapur beach area were similar to the monazite sand-bearing high background radiation areas of southern and southwestern coastal tracts of India and other similar areas of the world. The major contributors to the enhanced level of radiation are monazite and zircon sands.

Environmental Exposure↗
PubMed2004

Molecular analysis of GAA repeats and four linked bi-allelic markers in and around the frataxin gene in patients and normal populations from India.

Friedreich ataxia (FRDA), the most common type of ataxia worldwide, is an autosomal recessive disease. Homozygous expansion of GAA repeats in the first intron of the frataxin gene constitute the major type of mutation that causes the disease. The prevalence of FRDA in diverse ethnic populations of India has not been widely studied. We have studied the distribution of polymorphic GAA repeats in the frataxin gene among 6 clinically diagnosed patients and 160 ethnically matched normal individuals, to gather information on the prevalence of FRDA in the eastern part of India. Homozygous expansion in the range of 250-730 GAA repeats was detected among the patients. Among normal individuals, we observed a unimodal distribution of GAA repeats, consisting of 10 different alleles ranging from 7 to 16 GAA repeats, where the 9 repeat allele had maximal frequency. Only 5.9% of all chromosomes were found to harbour >12 GAA repeats. Haplotype analysis using closely linked four bi-allelic markers in and around the frataxin gene indicated that 66.7% of the expanded alleles harbour the ATCC haplotype that has been reported worldwide. This haplotype was present in 53.3% of the chromosomes with >12 GAA repeats, and accounted for only 3.8% of chromosomes with 7 to 12 GAA repeats. We found one novel haplotype, ACCT, among the expanded alleles as well as among normal individuals, though at low frequency; this haplotype may be characteristic of Indian populations.

Adolescent↗
PubMed2004

Feasibility of optimizing the dose distribution in lung tumors using fluorine-18-fluorodeoxyglucose positron emission tomography and single photon emission computed tomography guided dose prescriptions.

The information provided by functional images may be used to guide radiotherapy planning by identifying regions that require higher radiation dose. In this work we investigate the dosimetric feasibility of delivering dose to lung tumors in proportion to the fluorine-18-fluorodeoxyglucose activity distribution from positron emission tomography (FDG-PET). The rationale for delivering dose in proportion to the tumor FDG-PET activity distribution is based on studies showing that FDG uptake is correlated to tumor cell proliferation rate, which is shown to imply that this dose delivery strategy is theoretically capable of providing the same duration of local control at all voxels in tumor. Target dose delivery was constrained by single photon emission computed tomography (SPECT) maps of normal lung perfusion, which restricted irradiation of highly perfused lung and imposed dose-function constraints. Dose-volume constraints were imposed on all other critical structures. All dose-volume/function constraints were considered to be soft, i.e., critical structure doses corresponding to volume/function constraint levels were minimized while satisfying the target prescription, thus permitting critical structure doses to minimally exceed dose constraint levels. An intensity modulation optimization methodology was developed to deliver this radiation, and applied to two lung cancer patients. Dosimetric feasibility was assessed by comparing spatially normalized dose-volume histograms from the nonuniform dose prescription (FDG-PET proportional) to those from a uniform dose prescription with equivalent tumor integral dose. In both patients, the optimization was capable of delivering the nonuniform target prescription with the same ease as the uniform target prescription, despite SPECT restrictions that effectively diverted dose from high to low perfused normal lung. In one patient, both prescriptions incurred similar critical structure dosages, below dose-volume/function limits. However, in the other patient, critical structure dosage from the nonuniform dose prescription exceeded dose-volume/function limits, and greatly exceeded that from the uniform dose prescription. Strict compliance to dose-volume/ function limits would entail reducing dose proportionality to the FDG-PET activity distribution, thereby theoretically reducing the duration of local control. Thus, even though it appears feasible to tailor lung tumor dose to the FDG-PET activity distribution, despite SPECT restrictions, strict adherence to dose-volume/function limits could compromise the effectiveness of functional image guided radiotherapy.

Algorithms↗
PubMed2004

Acute intracerebral haematoma--an unusual presentation of herpes simplex encephalitis.

A young man presented with acute headache, behavioral abnormality and CT scan evidence of intracerebral hematoma. Detailed investigation established its infective origin due to herpes simplex virus type-I. The patient made an excellent recovery following a course of acyclovir. Frank intracerebral haematoma in the form of well defined mass on CT scan in patient with herpes simplex encephalitis is extremely rare.

Adult↗
PubMed2004

Arthropathic presentation of Wilson's disease.

A patient is described who presented with polyarthritis involving small and large joints of limbs with later onset of tremors affecting all four extremities. Investigations including genetic study confirmed the diagnosis of Wilson's disease (WD). The case highlights the importance of considering the possibility of WD in young patient presenting with repetitive unexplained joint symptoms with or without tremor.

Adult↗
PubMed2004

Henoch-Schonlein purpura with intracerebral haemorrhage.

Henoch-Schonlein purpura is a leucocytoclastic vasculitis commonly seen among children and young adults. Neurological complications, though rare, include focal cerebral deficit, coma, convulsion, subarachnoid hemorrhage and chorea. We are reporting a 12 years boy with Henoch-Schonlein purpura who developed a large intracerebral hematoma in right occipital lobe. He made an uneventful recovery with conservative treatment and one year follow up revealed no major neurological sequelae.

Cerebral Hemorrhage↗
PubMed2003

Immunocytochemical detection of p21ras, Raf-1, ERK1/MAP kinase and PKC isoforms in a 20-methylcholanthrene-induced transformed murine embryonal fibroblast cells in culture.

An immunocytochemical study using antibodies against p21ras, Raf-1, MAP kinase/ERK1 and PKCalpha, beta, gamma, delta, epsilon, zeta, isoforms were performed on a 20-methylcholanthrene-induced transformed murine embryonal fibroblast cells in both in vitro and in vivo growth conditions. Altered expression of p21ras, Raf-1, MAP kinase in this particular cell line strongly supported the previous findings of the activation of one component of signal transduction under the influence of the other in the MAP kinase cascade of signal transduction during neoplastic transformation and which also seemed to be involved in CNCI-PM-20 cell line. The altered expression of PKCalpha, beta, and delta was thought to be an epigenetic event occurring under the indirect influence of other changes in these cells. Host physiology and metabolism did not have much impact on the expression of these gene products after biological incubation of these cells in syngenic host.

Animals↗
PubMed2003

Compressive myelopathy due to nocardiosis from dermal lesion.

Nocardiosis refers to locally invasive or disseminated infection associated with Nocardia species. Most infections enter through respiratory tract and then disseminate systemically. Rarely primary nocardial infection of the skin of the back may spread to contiguous structures including vertebrae. A 30 years male presented with indolent skin lesion in the upper dorsal region of the back for one year following an accident and subsequently developed features of spinal cord compression and parenchymal involvement of lung. The rarity of such type of spread in an immuno-competent individual has been highlighted.

Adult↗
PubMed2003

A prospective study on histochemical observation of thyroid gland at prepubertal Black Bengal goat.

In the present study, Period Acid Schiff (PAS), Verhoeff's and Van Gieson stains were used in the Department of Anatomy and Histology to observe the histochemical architecture of thyroid gland at prepubertal Black Bengal goat. Thyroid follicular cells were cuboidal in prepubertal goats. These cells showed moderate PAS-positive reaction in prepubertal group. PAS activity in the basement membrane of the thyroid follicles was mild in prepubertal Black Bengal goats. The lumen of the thyroid follicles contained homogenous intense PAS positive colloid materials in prepubertal goats. Parafollicular cells showed intense PAS positive reaction for glycogen in prepubertal goats. Capsule, connective tissue septa, interfollicular connective tissue of the thyroid gland mainly composed of collagen fiber. The wall of blood vessels in the capsule and interfollicular blood capillaries was composed of collagen fiber and elastic fiber. Elastic fiber formed the inner layer of the blood vessels showed blue black to black color. Inner layer of the capsule penetrated the gland parenchyma divided the gland into indistinct lobe and lobules. Collagen fiber distributed around the thyroid follicle formed the interfollicular stroma of the thyroid gland. The results of the present study can also be used to compare with that of human specially in AutoImmune Thyroiditis (AIT).

Animals↗
PubMed2003

Comparison of oil-in-water emulsions manufactured by microfluidization and homogenization.

The purpose of this study was to compare drug-free model submicron oil-in-water (o/w) emulsions manufactured by high-speed homogenization and microfluidization. The study was aimed at evaluating the influence of these two manufacturing processes on the stability of the emulsions with respect to emulsifier concentration. Stability was defined in terms of dispersed droplet diameter growth over time. The study was also directed towards identifying the minimum emulsifier concentrations required by either processing method within the same model o/w systems to produce emulsions viable throughout the study period of three months. The Microfluidizer 110L was found to be more effective than the homogenizer in producing stable o/w submicron emulsions using triglycerides of caprylic/capric acid as the oil phase and combinations of emulsifiers (polyoxyethylene sorbitan oleate with high HLB and sorbitan monooleate with low HLB) at low emulsifier concentrations. Submicron emulsions prepared by the microfluidization process had smaller droplet diameters and exhibited less droplet diameter growth over time compared to high-speed homogenization. At emulsifier concentrations below 20% w/w, the droplet diameter or stability of the dispersed phase of the sub-micron emulsions prepared by either process was found to be dependent on the emulsifier content.

Drug Compounding↗
PubMed2003

Sequence analysis of segment a of a field virus isolate from an outbreak of Infectious bursal disease in India.

Sequence analysis of genome segment A of an Indian Infectious bursal disease virus (IBDV) field isolate (KT1/99) revealed total 95 nucleotide substitutions, resulting in 17 amino acid changes. Of these, five amino acid changes, namely F60S, T137I, I374V, V519I and E682D were unique to the KT1/99 isolate. The amino acid change P222A and the proposed hot mutation spot 680Y, reported to be present in very virulent IBDV isolates were also found in KT1/99. This isolate had nucleotide divergence of 1.1% to 4.95% from the other reported serotype 1 IBDV isolates and 19.6% from serotype 2 strain OH in polyprotein gene sequence, while divergence at amino acid level was 0.6% to 2.9% and 11.4%, respectively. Based on both nucleotide and amino acid sequence analysis, KT1/99 was grouped phylogenetically with the reported Bangladesh isolate BD3/99 in one cluster along with other reported very virulent isolates in same lineage.

Amino Acid Sequence↗
PubMed2003

Parkinsonism plus syndrome--a review.

Parkinsonism plus syndrome is a group of heterogeneous degenerative neurological disorders, which differ from the classical idiopathic Parkinson's disease in certain associated clinical features, poor response to levodopa, distinctive pathological characteristics and poor prognosis. Associated clinical features include symmetrical onset, infrequent or atypical tremor, prominent rigidity in axial musculature, bradykinesia, early postural instability, supranuclear gaze palsy, early autonomic failure, pyramidal affection, cerebellar involvement, alien limb phenomenon, apraxia and significant early cognitive dysfunction in some cases. Progressive supranuclear palsy (PSP), multiple system atrophy (MSA) and dementia with Lewy body disease (DLB) are commoner disorders. Less frequent disorders are cortico-basal ganglionic degeneration (CBGD), frontotemporal dementia with chromosome 17 (FTDP-17), Pick's disease, parkinsonian-dementia complex of Guam, Pallidonigral degeneration, Wilson's disease and a rigid variant of Huntington's disease. During the last 3 decades, major progress has been made in understanding PSP, CBGD and FTDP-17, which are tau disorders. MSA and DLB together with idiopathic Parkinson's disease are called alpha-synucleinopathies. Recent studies show that the diagnosis of these Parkinsonism plus syndromes improves when strict diagnostic criteria are used. However, unusual presentations may pose a diagnostic challenge. The shortcomings of the current studies demand the need for further research to identify biologic markers that may allow earlier diagnosis, and understanding of the factors leading to alpha-synuclein or tau aggregation. Identification of therapeutic strategies that may prevent the aggregation of these proteins and rescue dysfunctional cells has been stressed. This review focuses on the advances in the clinical, neuroimaging, pathologic, genetic and management aspects of these disorders.

Humans↗