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Biomedical subjects

S Pradhan

Publications and source records attributed to S Pradhan.

At least 19 recordsLinked to original sources
PubMed2007

Leiomyosarcoma of kidney: a case report with long term result after radiotherapy and chemotherapy.

Leiomyosarcoma of the kidney is a rare entity with poor prognosis. Among renal sarcomas, it is the most common histologic subtype amounting to 50-60% of all cases. The tumors usually arise from either the renal capsule or smooth muscle tissue in the renal pelvic wall. We describe a case of renal leiomyosarcoma that presented with history of left flank pain. Physical examination was normal. Abdominal ultrasound showed a solid lesion of 38 x 36 mm arising from the left kidney. Intravenous urography showed cut off of both major and minor calyces of the left kidney from its pelvis with a normal right kidney. Exploratory laparotomy revealed a well-encapsulated mass confined to the renal parenchyma for which radical nephrectomy was performed. Histopathology showed a Grade I leiomyosarcoma arising from the renal capsule. Adjuvant chemotherapy and sandwich radiotherapy was given and he is disease free after six and half years of follow up. The rarity of this disease, its severity and poor prognosis, uncommon form of presentation, resulting delay in diagnosis and difficulty in management is highlighted and reported.

Combined Modality Therapy↗
PubMed2006

Development of passive haemagglutination (PHA) and haemagglutination inhibition (HAI) technique for potency estimation of Cobra Antisnake Venom Serum (ASVS).

Antibodies against snake venom or antivenom potency are assayed quantitatively by in-vivo neutralization test in mice, which requires large number of laboratory animals. In potency assays of biological substances such as antivenoms, it is highly desirable to avoid suffering and death of animals by substituting in-vivo method with in-vitro methods, provided such methods measure life-saving capability with precision similar to that of in-vivo method. The in-vitro tests determine the neutralizing power of antivenom by permitting the evaluation of a particular biological activity of the venom and its neutralization after mixing the venom with the antivenom [Theakston RDG, Reid HA. Development of simple standard assay procedures for the characterization of snake venom. Bull WHO 1983;61:949-956; Gutierrez JM, Rojas G, Lomonte B, Gene JA, Chaves F, Alvarado J, et al. Standardizing of assays for testing the neutralizing ability of antivenoms. Toxicon 1990;28:1127-1129; Theakston R.D.G. Comments on letter of Gutierrez et al. on standardization of assays for testing the neutralizing ability of antivenoms. Toxicon 1990;28:1131-1132; Harvey AL, Barfaraz A, Thomson E, Faiz A, Preston S, Harris JB. Screening of snake venom for neurotoxic and myotoxic effects using simple in-vitro preparation from rodents and chicks. Toxicon 1994;32:257-265; World Health Organization Progress in characterization of venom and standardization of anti-venoms. Geneva: WHO offset publication; 1981. p. 58.]. Hence, the ideal requirements for an assay in detecting venom and venom antibody include high level of sensitivity, specificity (ability to differentiate between venom and venom antibody produced by closely related species of snakes), reproducibility and simplicity. A new in-vitro procedure for quantitative analysis of potency of ASVS by passive haemagglutination (PHA) and haemagglutination inhibition (HAI) has been explored. The methods described are simple, rapid, economical, reproducible and useful in replacing the more expensive in-vivo neutralization assays. Moreover, it also eliminates the use of laboratory animals.

Animals↗
PubMed2006

Viral oncoproteins target the DNA methyltransferases.

Small DNA tumour viruses have evolved a number of mechanisms to drive nondividing cells into S phase. Virally encoded oncoproteins such as adenovirus E1A and human papillomavirus (HPV) E7 can bind an array of cellular proteins to override proliferation arrest. The DNA methyltransferase Dnmt1 is the major mammalian enzyme responsible for maintaining CpG methylation patterns in the cell following replication. One of the hallmarks of tumour cells is disrupted DNA methylation patterns, highlighting the importance of the proper regulation of DNA methyltransferases in normal cell proliferation. Here, we show that adenovirus 5 E1A and HPV-16 E7 associate in vitro and in vivo with the DNA methyltransferase Dnmt1. Consistent with this interaction, we find that E1A and E7 can purify DNA methyltransferase activity from nuclear extracts. These associations are direct and mediated by the extreme N-terminus of E1A and the CR3 zinc-finger domain of E7. Furthermore, we find that a point mutant at leucine 20 of E1A, a residue known to be critical for its transformation functions, is unable to bind Dnmt1 and DNA methyltransferase activity. Finally, both E1A and E7 can stimulate the methyltransferase activity of Dnmt1 in vitro. Our results provide the first indication that viral oncoproteins bind and regulate Dnmt1 enzymatic activity. These observations open up the possibility that this association may be used to control cellular proliferation pathways and suggest a new mechanism by which small DNA tumour viruses can steer cells through the cell cycle.

Cell Line↗
PubMed2006

Effect of prevailing local treatment options of breast cancer on survival outside controlled clinical trials: experience of a specialist breast unit in North India.

BACKGROUND: This study aimed at analyzing different treatments of breast cancer (BC) prevalent in the region, their effect on patients' survival, and discusses the most suitable method within available resources. METHODS: The study was set up at a tertiary care hospital in north India. We retrospectively reviewed data of 473 female BC patients who attended the departments of Surgical Oncology and Radiotherapy from January 1997 to December 1999. Patients with cTNM stage IV and inoperable stage III were included; those who defaulted or were lost to follow-up were excluded. Out of 473 patients, 372 were selected. The selected patients were divided into groups on the basis of place and type of local treatment they received: (1) local excision only, (2) standard breast conservation therapy (BCT), (3) total mastectomy (TM) + axillary lymph node dissection + radiotherapy (RT), and (4) modified radical mastectomy (MRM) + RT. Data regarding recurrence and survival were analyzed in December 2005. Minimum follow-up was 6 years. RESULTS: Overall recurrence rates were significantly higher in patients operated elsewhere (P <0.0001). Of 194 operated at our Breast Unit, 25 (14.6%) of 171 MRM patients and none of 23 BCT had recurrence. Of 178 patients operated elsewhere, 44 (100%), 6 (42.9%), 41 (41%), and 8 (40%) developed recurrence in groups 1, 2, 3, and 4 respectively. Overall survival was significantly better in patients with MRM at our unit versus TM outside (93.6% vs. 80%). CONCLUSIONS: Several types of treatment from improper local excision alone, BCT, TM, to a carefully done MRM are prevalent here. Properly done, MRM yields significant local control with survival benefit and appears to remain the gold standard in management of our BC patients.

Adult↗
PubMed2005

Interaction between the water soluble poly{1,4-phenylene-[9,9-bis(4-phenoxy butylsulfonate)]fluorene-2,7-diyl} copolymer and ionic surfactants followed by spectroscopic and conductivity measurements.

The interaction has been studied in aqueous solutions between a negatively charged conjugated polyelectrolyte poly{1,4-phenylene-[9,9-bis(4-phenoxybutylsulfonate)]fluorene-2,7-diyl} copolymer (PBS-PFP) and several cationic tetraalkylammonium surfactants with different structures (alkyl chain length, counterion, or double alkyl chain), with tetramethylammonium cations and with the anionic surfactant sodium dodecyl sulfate (SDS) by electronic absorption and emission spectroscopy and by conductivity measurements. The results are compared with those previously obtained on the interaction of the same polymer with the nonionic surfactant C12E5. The nature of the electrostatic or hydrophobic polymer-surfactant interactions leads to very different behavior. The polymer induces the aggregation with the cationic surfactants at concentrations well below the critical micelle concentration, while this is inhibited with the anionic SDS, as demonstrated from conductivity measurements. The interaction with cationic surfactants only shows a small dependence on alkyl chain length or counterion and is suggested to be dominated by electrostatic interactions. In contrast to previous studies with the nonionic C12E5, both the cationic and the anionic surfactants quench the PBS-PFP emission intensity, leading also to a decrease in the polymer emission lifetime. However, the interaction with these cationic surfactants leads to the appearance of a new emission band (approximately 525 nm), which may be due to energy hopping to defect sites due to the increase of PBS-PFP interchain interaction favored by charge neutralization of the anionic polymer by cationic surfactant and by hydrophobic interactions involving the surfactant alkyl chains, since the same green band is not observed by adding either tetramethylammonium hydroxide or chloride. This effect suggests that the cationic surfactants are changing the nature of PBS-PFP aggregates. The nature of the polymer and surfactant interactions can, thus, be used to control the spectroscopic and conductivity properties of the polymer, which may have implications in its applications.

Journal Article↗
PubMed2004

A central demyelinating disease with atypical features.

There are clinical, laboratory and imaging criteria to distinguish multiple sclerosis (MS) from neuromyelitis optica (NMO) and acute disseminated encephalomyelitis (ADEM). While MS has unknown aetiology, NMO is commonly associated with vasculitis and ADEM is supposed to be parainfectious in origin. In the present study, six patients are described from a group of 67 with a central demyelinating disorder whose clinical presentation did not conform to existing diagnostic criteria for ADEM, NMO or MS. Their clinical, laboratory and imaging characteristics were studied and analysed. Some features suggested a particular diagnosis but some other features favoured another diagnosis. The features included spinal cord involvement in a large vertical segment with cord swelling, optic neuritis, no lesions in the cerebral cortex, paraplegia with urinary retention during the acute phase, no oligoclonal band in cerebrospinal fluid, absence of any evidence of vasculitis, wide time-gap between spinal cord and optic nerve involvement, good recovery from acute phase of disease and a relatively benign course. We conclude that there exists a subpopulation of patients with central demyelinating disease in this region with mixed clinical features. Overall features suggested either a widened clinical spectrum of MS, NMO or ADEM or a possible overlap between them.

Adolescent↗
PubMed2004

Infectious meningitis: prospective evaluation with magnetization transfer MRI.

The study was performed with the aim of prospectively characterizing infectious meningitis of different aetiology using magnetization transfer (MT) MRI. Spin-echo (SE) T(1), T(2) and pre- and post-contrast T(1) weighted MT images in 100 patients with aetiologically proven meningitis were evaluated for the visibility and enhancement of the meninges on pre- and post-contrast T(1) weighted MT images, respectively. The MT ratio (MTR) was calculated from the thickened meninges in tuberculous meningitis. In addition, the percentage difference in the mean signal intensity (SI) of the meninges and adjacent brain parenchyma was calculated and compared between different groups using 2-tailed student's t-test. T(1) weighted MT images were highly sensitive (96%) in the detection of abnormal meningeal enhancement. Meninges were visible on pre-contrast T(1) weighted MT images only in patients with tuberculous meningitis. The MTR from meninges in tuberculous infection was 19.10+/-1.02, and the percentage difference in the mean SI of the meninges and the adjacent T(2) normal brain parenchyma was significantly higher (p<0.05) in the tuberculous group compared with that in the non-tuberculous group. MT MRI is an important technique for the detection and characterization of infectious meningitis of different aetiology. Visibility of the meninges on pre-contrast T(1) weighted MT images may be considered highly suggestive of tuberculous meningitis.

Adolescent↗
PubMed2003

Intermittent symptoms in neurocysticercosis: could they be epileptic?

OBJECTIVES: Some patients with neurocysticercosis (NCC) develop perilesional gliosis during the course of healing and carry poor prognosis for the seizure control. We evaluated the clinical status of these patients during complete control of their original seizures on anti-epileptic drugs (AED). MATERIAL AND METHODS: We studied 172 patients with solitary NCC, 45 with perilesional gliosis as visible on magnetization transfer spin echo (MTSE) magnetic resonance imaging and 127 without gliosis, for any abnormal symptom during the course of their "seizure-free" period. All of them received optimum doses of AED to control the original seizures. RESULTS: Patients with gliosis had high incidence of abnormal symptoms with or without corresponding abnormalities on surface electroencephalogram (EEG). These symptoms disappeared on increasing the dose or adding a new AED. The symptoms, which were transient episodic in nature, included heaviness, dystonic posturing, weightlessness, numbness and alien limb phenomenon on the side of the body contralateral to cerebral lesion, and headache. CONCLUSION: Patients with NCC who develop perilesional gliosis during the process of healing tend to suffer from disturbing intermittent symptoms during their apparent control of seizures. The symptoms are controllable with increased dosage of previously prescribed or addition of another AED. As these symptoms could possibly be epileptic in nature, their identification and treatment may have a bearing on long-term seizure control after stopping AED therapy.

Adolescent↗
PubMed2003

Intensified treatment of type 2 diabetes--positive effects on blood pressure, but not glycaemic control.

BACKGROUND: Since publication of the UK Prospective Diabetes Study (UKPDS) in 1998, there has been a clear evidence base for tight glycaemic (HBA(1c) < 7.0%) and blood pressure (BP < 140/85 mmHg) control. AIM: To determine the effect of UKPDS-based intensified glycaemic and BP targets on the care of type 2 diabetic patients attending a routine diabetes clinic. DESIGN: Two surveys, each of 500 consecutively attending type 2 diabetic patients. METHODS: The first survey was in a 3-month period in 1999, shortly after publication of the UKPDS study. The second was identical, but 2 years later. Glycaemic control (by DCCT-aligned HBA(1c)), BP and treatment details were recorded in both. RESULTS: BP control was significantly improved in the second survey (mean +/- SD systolic BP from 151 +/- 25 to 146 +/- 26 mmHg, p = 0.001; diastolic from 77 +/- 13 to 72 +/- 12 mmHg, p < 0.0001) and the proportion of patients on anti-hypertensive treatment increased from 33% to 60% (p < 0.0001). Mean HbA(1c) however remained unchanged (8.7 +/- 1.8% in 1999 vs. 8.5 +/- 1.8% in 2001), although there was evidence of more intensive treatment patterns, with declining numbers on diet alone and more on oral agents and/or insulin. DISCUSSION: Intensified BP control may be achievable within the confines of routine diabetes care, but achievement of optimal glycaemic targets remains problematic.

Administration, Oral↗
PubMed2002

Dynamic critical behavior of failure and plastic deformation in the random fiber bundle model.

The random fiber bundle (RFB) model, with the strength of the fibers distributed uniformly within a finite interval, is studied under the assumption of global load sharing among all unbroken fibers of the bundle. At any fixed value of the applied stress sigma (load per fiber initially present in the bundle), the fraction U(t)(sigma) of fibers that remain unbroken at successive time steps t is shown to follow simple recurrence relations. The model is found to have stable fixed point U*, filled (sigma) for applied stress in the range 0 < or = sigma < or = sigma(c), beyond which total failure of the bundle takes place discontinuously [abruptly from U*, filled (sigma(c)) to 0]. The dynamic critical behavior near this sigma(c) has been studied for this model analyzing the recurrence relations. We also investigated the finite size scaling behavior near sigma(c). At the critical point sigma = sigma(c), one finds strict power law decay (with time t) of the fraction of unbroken fibers U(t)(sigma(c)) (as t--> infinity). The avalanche size distribution for this mean-field dynamics of failure at sigma < sigma(c) has been studied. The elastic response of the RFB model has also been studied analytically for a specific probability distribution of fiber strengths, where the bundle shows plastic behavior before complete failure, following an initial linear response.

Journal Article↗
PubMed2002

Multiparametric quantitation of the perilesional region in patients with healed or healing solitary cysticercus granuloma.

The purpose of this study was to compute T2 values and magnetization transfer (MT) ratios in the perilesional region of healing and healed cysticercus granulomas to determine if there are T2 abnormalities not apparent on conventional T2-weighted imaging and to determine the relationship between seizure control and the quantitative measures. Sixty-three patients were studied. T2 values and MT ratios were computed for the perilesional region and were compared with measurements from the contralateral normal-appearing region. A significantly increased T2 value was found for the perilesional region compared to the corresponding contralateral region despite the absence of qualitative abnormality on conventional T2-weighted magnetic resonance imaging. For patients showing normal-appearing perilesional regions on MT imaging, there was no significant difference in T2 and MT ratios between the perilesional and the normal contralateral regions. There was a statistically significant inverse correlation between perilesional T2 values and MT ratios, suggesting each was associated with perilesional gliosis. The study illustrates that quantitative evaluation of MT ratios and T2 augments the qualitative visual assessment of the perilesional region in healing or healed cysticercus granulomas.

Adult↗
PubMed2002

Utility of databases and information technology in pediatric neurology.

Significant number of neurological patients in the pediatric age group have genetic and/or metabolic basis. It is difficult to remember details of each of them as their number is very large and the disorders are encountered infrequently. This impracticality necessitates the use of various websites and data base search. The internet has become a tool by which one can obtain and disseminate information. It has enhanced the medical person's ability to know at the earliest the developments in different medical specialities. Furthermore, these rare disorders are being recognized on the basis of specialized tests available only at selected centres which deal with few of these disorders. Our objective is to provide pediatric neurologists easy access to the expanding body of medical information and also to make them aware of the advancements in information technology, which is likely to facilitate telemedicine as a future consultancy service. Information about these diseases can also be facilitated by e-consultations.

Databases as Topic↗
PubMed2002

Valley sign in duchenne muscular dystrophy: importance in patients with inconspicuous calves.

Several patients of Duchenne muscular dystrophy (DMD) do not demonstrate clinically remarkable calf hypertrophy. A new clinical sign visible behind the shoulders, which may be called 'valley sign', was tested for its utility in such cases as clinical diagnosis becomes difficult in these patients. Out of 142 DMD patients seen in the last 7 years, 12 were found to have inconspicuous calves. All the 12 patients had clinical, biochemical and/or genetic evidence of DMD. The new sign was examined by 3 independent observers in these 12 DMD patients and in 10 patients with other neuromuscular diseases. Eight DMD patients and none of the others showed positive sign. This signifies importance of this sign in the clinical diagnosis of DMD in those children in whom the calf muscle bulk is apparently normal.

Adolescent↗
PubMed2002

Needle aspiration as a diagnostic tool and therapeutic modality in suppurative lymphadenitis following Bacillus Calmette Guerin vaccination.

OBJECTIVES: Outbreaks are known to occur after Bacillus Calmette Guerin (BCG) vaccination. An outbreak of suppurative lymphadenitis in 18 infants, following BCG vaccination is reported from Sikkim, with incidence of 8.6%. The outbreak occurred after a change of vaccine. METHODS: In a prospective study the cases of suppurative lymphadenitis were diagnosed by needle aspiration cytology and culture of the material aspirated and managed only with repeated needle aspiration and no antitubercular treatment was given. RESULTS: Cytomorphology revealed necrosis alone in 66.6% and necrotizing granulomas in 22.2%. Acid and alcohol fast bacilli were detected in 77.7% cases. Mycobacterium bovis was isolated in eight cases. One case of staphylococcal suppurative lymphadenitis was detected. Sixteen cases were managed with weekly aspiration with mean period of resolution in eight weeks. CONCLUSIONS: Needle aspiration is useful in the diagnosis and effective in the management of these cases. No antitubercular treatment is desired and required in the cases of suppurative lymphadenitis following BCG vaccination.

Adjuvants, Immunologic↗
PubMed2002

Demonstration of scolex in calcified cysticercus lesion using gradient echo with or without corrected phase imaging and its clinical implications.

AIM: This study was performed to determine the magnetic resonance imaging (MRI) sequence that was best suited to demonstrate the scolex in a calcified lesion and to seek the explanation for the appearance of a negative phase in a calcified scolex on corrected gradient refocused echo (GRE) phase imaging. MATERIALS AND METHODS: Forty-nine patients with single/multiple computed tomography (CT) documented homogeneous calcified lesions and/or calcified scolices in cysts were studied with conventional spin echo and corrected GRE phase imaging. Calcium and different paramagnetic substances from cysticerci scolices of a sample of infected swine muscle were quantified. RESULTS: The scolex could be demonstrated in 29/39 patients with single calcified lesion. GRE imaging with an echo time of 35ms was the only sequence that demonstrated scolex in all these 29 cases. 15/29 patients with a single calcified lesion, in all 10 patients with multiple calcified lesions and infected swine muscle with multiple cysts and calcified scolex, corrected GRE phase imaging showed negative phase in all these scolices. Estimation of minerals from the calcified scolices from the swine muscle showed by spectroscopic techniques 41.2% of the total mineral contents as paramagnetic substances. CONCLUSION: We conclude that GRE imaging is the imaging method of choice for demonstration of the scolex in a CT calcified lesion. The negative phase on corrected GRE phase imaging is due to the presence of large amount of paramagnetic substances.

Adolescent↗