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Biomedical subjects

S Jain

Publications and source records attributed to S Jain.

At least 271 records · Page 15Linked to original sources
PubMed1999

Electrocardiographic diagnosis of right ventricular infarction in the presence of left ventricular posterior infarction.

Conventional criteria of ST segment elevation in right sided chest leads or loss of initial 'r' wave in leads V3R or V4R have low sensitivity and specificity in diagnosing right ventricular involvement in the presence of left ventricular posterior infarction. Slurring of R wave either in right sided chest leads or in lead aVR can diagnose right ventricular involvement in such a setting with a sensitivity of 70% and specificity of 94%.

Echocardiography↗
PubMed1999

Electrical and lightning injuries.

Electricity and lightning can cause injury in a variety of ways, some of which may remain hidden from the unsuspecting physician until it is too late. Prompt and, if necessary, prolonged resuscitation are of proven benefit. Particular attention must be paid to the patient who suffers high-voltage injury, and deep electrothermal burns on damage to vital organs should be excluded. Uncommonly late sequelae are seen, and such patients require appropriate care.

Burns, Electric↗
PubMed1999

Phototherapeutic keratectomy for treatment of recurrent corneal erosion.

PURPOSE: To study the role of phototherapeutic keratectomy (PTK) in the management of recurrent corneal erosion (RCE) refractory to other forms of treatment. SETTING: The Eye Department of Leicester Royal Infirmary, a tertiary referral center, Leicester, England. METHOD: A retrospective analysis of all patients who had PTK for refractory RCE between July 1994 and October 1998 was performed. The patients were recalled to determine whether they had further symptoms and whether there had been a change in their refractive error or their best corrected visual acuity. RESULTS: Seventy-seven eyes of 68 patients were treated and divided into 3 etiologic groups: trauma, 40 eyes; corneal dystrophy, 24 eyes; and no established cause (idiopathic), 13 eyes. Phototherapeutic keratectomy was combined with photorefractive keratectomy (PRK) in 6 eyes with a good result. A single treatment was performed in 71 eyes (92.2%). No significant refractive change occurred in 67.5% of eyes; 22.1% developed hyperopia (range 0 to +2.0 diopters [D]), and 10.3% developed myopia (range 0 to -1.5 D). Best corrected visual acuity was unchanged in 72.7% of eyes; 11.7% lost 1 Snellen line and 15.5% gained 1 line. There were no symptoms in 68.8% of eyes; in 31.2%, minor symptoms were noted in the morning, and these patients continued to use ocular lubricants at night. CONCLUSION: Phototherapeutic keratectomy is a safe and effective treatment for refractory RCE and, where appropriate, can be combined with PRK.

Adult↗
PubMed1999

Mechanical properties of powders for compaction and tableting: an overview.

This review provides an insight into mechanical properties that are critical to understanding powder processing for tableting. Various parameters that reflect these basic fundamental properties of powder and their evaluation by different techniques are described. Some recent examples in which these techniques are used in drug substance selection, formulation optimization or scale-up are also provided.

Journal Article↗
PubMed1999

Prevalence and determinants of hypertension in an un-industrialised rural population of North India.

Recent studies have indicated a rising prevalence of hypertension in rural and urban areas of India. A population-based survey was carried out during 1994-1995 in seven rural and non-industrialised villages around RaipurRani block in the state of Haryana, India, to determine the prevalence of hypertension and its associated risk factors. A total of 2559 individuals (86% of the eligible population) in the 16 to 70-year age group were interviewed using a pre-tested structured questionnaire to find out the lifestyle characteristics. Three blood pressure (BP) readings were recorded with a random zero sphygmomanometer at three different times. One hundred and fourteen individuals (4.5%) were found to be hypertensive according to JNC V criteria (BP of > or = 140/90 mm Hg). Mean systolic and diastolic BPs were 116.9 and 71.7 mmHg in males and 119.1 and 72.7 mm Hg in female subjects respectively (P < 0.001). Females had significantly higher prevalence of hypertension than males (5.8% vs 3.0%, P < 0.05). Mean age of hypertensives (50.3 +/- 13.5 years) was higher than normotensives (34.9 +/- 14.5 years, P < 0.001). The prevalence of various risk factors among hypertensives as compared to normotensives were alcohol consumption (43.2% vs 23.1%, only among males, P < 0.001), higher economic status (P < 0.001) and smoking (43% vs 41.5%, P > 0.05). In addition hypertensives had higher mean weight (53.8 kg vs 48.4 kg, P < 0.001) and higher body mass index (21.5 vs 18.9 kg/m2, P < 0.001). Analysis showed that advancing age, sedentary lifestyle, higher alcohol consumption and higher body mass index are the risk factors for hypertension in the rural un-industrialised population of India.

Adolescent↗
PubMed1999

Comparison of the expression of fibrosis-associated genes in glomeruli after renal transplantation between conventional cadaveric and non-heart-beating donors.

BACKGROUND: The main difference between cadaveric heart-beating donors and non-heart-beating donors (NHBDs) is the degree of warm ischaemia to which the kidney is subjected. This study was designed to see if this affected the expression of fibrosis-associated genes in the early period after transplantation. METHODS: A series of 29 cadaveric and 19 NHBD renal transplants was studied. Patients underwent protocol needle-core renal transplant biopsies at 1 week, 3 months and 6 months after transplantation. At least two individual glomeruli were isolated from each biopsy. Messenger RNA was extracted and genes of interest were amplified by reverse transcriptase-polymerase chain reaction, then quantified in an enzyme-linked immunosorbent assay system. RESULTS: Delayed graft function was common in NHBD (17 of 19) compared with cadaveric transplants (six of 29) (P < 0.0001). Acute rejection rates were similar. The level of tissue inhibitor of metalloproteinase 1, an inhibitor of extracellular matrix degradation, was higher in kidneys from NHBDs at 1 week (P = 0.02). There were no other statistically significant differences in the expression of fibrosis-associated genes between the two groups. CONCLUSION: Although the increased ischaemic injury in kidneys retrieved from NHBDs leads to a higher rate of delayed graft function, this does not translate into increased expression of fibrosis-associated genes after the first week.

Adult↗
PubMed1999

Aluminum enhances iron uptake and expression of neurofibrillary tangle protein in neuroblastoma cells.

Aluminum (Al) and iron (Fe) have been implicated as playing a toxic role in the pathologic lesions of Alzheimer's disease. In the following report we describe the uptake and toxicity of Al, the effect of Al on Fe uptake, and the expression of neurofibrillary tangle (NFT) protein in murine neuroblastoma cells (Neuro 2A). Significant cell Al uptake and inhibition of cell growth were seen in Neuro 2A cells at 24, 48, 72, and 96 h after plating in medium containing Al transferrin (Al-Tf) and Al citrate. Al-loaded Neuro 2A cells showed increased rates of 59Fe and 125I-Tf uptake and total cellular Fe content at 24, 48, 72, and 96 h after plating compared with control cultures. Significant increases in NFT protein staining were detected in Al-exposed cells at 72 and 96 h in culture compared with controls. The intensity of NFT staining in Al-loaded cells was directly proportional to the time in culture. There was no difference in malonyldialdehyde levels measured in control versus Al-loaded Neuro 2A cells. These results suggest that the accumulation of Al in Neuro 2A cells resulted in increased uptake of Fe, inhibition of cell growth, and expression of NFT protein, partially mimicking the pathological hallmarks of Alzheimer's disease. This model system may also be applicable for Al-induced dialysis dementia, because the Al concentrations at which cell toxicity occurred can be found in dialysis patients.

Aluminum↗
PubMed1999

Subcutaneous fluid administration--better than the intravenous approach?

Hypodermoclysis is a method of subcutaneous fluid administration particularly useful in elderly patients and in palliative care settings where intravenous access may be difficult. Subcutaneous fluid delivery is an effective method of rehydration and of opioid administration, and can prevent the need for intravenous catheterization and consequently hospitalization. It is a simple procedure to initiate, safe, less distressing to the patient, and does not predispose to intravascular related infections. The reported incidence of infection at the delivery site is extremely low. However, local guidelines should be agreed so that a standardized protocol is operated and risks of localized infection are minimized.

Fluid Therapy↗
PubMed1999

Pheochromocytoma associated with pregnancy: case report and review of the literature.

UNLABELLED: We report on a young woman with pheochromocytoma associated with pregnancy and review 41 other cases reported in the literature from 1988 to 1997. This review reveals that the overall maternal mortality was 4 percent and the fetal loss 11 percent; antenatal diagnosis of pheochromocytoma reduced maternal mortality to 2 percent; however, fetal loss was 14 percent. Diagnosis of pheochromocytoma was made antepartum in 83 percent of the cases. Although pheochromocytoma associated with pregnancy is rare, a high index of clinical suspicion must be kept and all those at risk must be investigated to achieve an early diagnosis and improved outcome. Once the diagnosis is confirmed, alpha-adrenergic blockade is essential and beta-blockade may be required. Magnetic resonance imaging and computerized tomography scan may be used to localize the tumor during the antenatal period. In early pregnancy, i.e., before 24 weeks, both tumor resection and medical treatment are associated with good fetal outcome; in later pregnancy, elective cesarean delivery followed by tumor resection results in favorable maternal and fetal outcome. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to understand the clinical manifestations of a pheochromocytoma during pregnancy, how to make the diagnosis of a pheochromocytoma during pregnancy, and to know the medical and surgical management of a pheochromocytoma during pregnancy.

Adrenal Gland Neoplasms↗
PubMed1999

Persistence in the zero-temperature dynamics of the diluted Ising ferromagnet in two dimensions.

The nonequilibrium dynamics of the strongly diluted random-bond Ising model in two dimensions (2D) is investigated numerically. The persistence probability, P(t), of spins which do not flip by time t is found to decay to a nonzero, dilution-dependent value P(infinity). We find that p(t)=P(t)-P(infinity) decays exponentially to zero at large times. Furthermore, the fraction of spins which never flip is a monotonically increasing function over the range of bond-dilution considered. Our findings, which are consistent with a recent result of Newman and Stein [Phys. Rev. Lett. 82, 3944 (1999)], suggest that persistence in diluted and pure systems falls into different classes. Furthermore, its behavior would also appear to depend crucially on the strength of the dilution present.

Journal Article↗
PubMed1999

Solitary cellular schwannoma (neurilemmoma) showing malignant changes: evaluation through magnetic resonance imaging (M.R.I.), surgical intervention, and histopathology.

Schwannoma (neurilemmoma) are common benign tumors arising from the peripheral nerve sheath. Malignant transformation is uncommon. A unique case showing such a transformation is reported highlighting the roles of magnetic resonance imaging, surgical intervention, and histopathology. The case was thoroughly investigated by learning the details of the sequence of events leading to the current status. The evaluation was made through magnetic resonance imaging. In addition, computed tomography and conventional radiography were used to locate any foci of calcification. Subsequently, the tumor's gross and microscopic morphology was defined by surgical intervention and histopathology. Malignant schwannoma of the left leg occupying the entire calf is extremely uncommon. Only ten cases have been reported thus far, including the current one from the Indian subcontinent. Malignant transformation in a schwannoma differs significantly from malignant nerve sheath tumors (erroneously called malignant schwannomas). An endeavour has been made to differentiate malignant transformation in schwannoma from other malignant peripheral nerve sheath tumors. An innovation in this direction is magnetic resonance imaging. This investigate procedure is imperative in such situations, along with surgery and histopathology, which may also help in classifying the condition.

Humans↗
PubMed1999

Family studies and human leukocyte antigen class II typing in Indian probands with seizures in association with single small enhancing computed tomography lesions.

PURPOSE: To define the clinical features of the syndrome of seizures associated with single, small, enhancing computed tomography (CT) lesions (SSELs) in 235 Indian probands and seizure types among their family members. Human leukocyte antigen (HLA) class II genomic typing in randomly selected 41 probands was done to identify the role of hereditary factors in this syndrome. METHODS: The seizure types among 235 probands, their clinical outcome, and seizures in their family members were studied. Family data were collected on relatives of 212 additional probands with neurologic diseases other than epilepsy. HLA class II antigens were studied by using polymerase chain reaction (PCR) amplified DNA and sequence-specific oligonucleotide probe (PCR-SSOP) hybridization. RESULTS: The seizures in 86% were partial with or without generalization; 77% had fewer than five seizures before the first CT scan. Evanescent focal neurologic deficits after seizures were noted in 40%. Most patients (97%) were treated with a single antiepileptic drug (AED). Significant resolution of the CT scan lesion was noted within 6 months in 125 (53%) of 235 cases. Two thirds of patients had no seizures while taking a single AED, and an additional 18% had no seizures even after their AEDs were discontinued. Epilepsy among relatives of Indian probands having seizures in association with SSELs was more common as compared with relatives of probands with other neurologic diseases. A family history of seizures was noted in 21% probands, the ratio of affected first- to second-degree relatives was 4.3:1, and 60% of affected sibs had syndromic concordance with probands. There was a positive association of HLA-DRB1*13 (Pc = 0.036) with this syndrome. CONCLUSIONS: The syndrome of seizures in association with SSELs seems to be a benign localization-related epileptic syndrome. Our results of HLA studies point to an inherited susceptibility to an infective agent, which in most cases is of cysticercal etiology.

Adult↗
PubMed1999

Prognostic value of dipyridamole thallium imaging after acute myocardial infarction in older patients.

OBJECTIVE: To assess the utility of intravenous dipyridamole thallium testing for predicting major cardiac events following acute myocardial infarction in older patients. DESIGN: Prospective cohort study with a median follow-up of 18 months. SETTING: A university teaching hospital. PARTICIPANTS: 73 patients aged 65 years and older with enzymatically confirmed acute myocardial infarction (mean age 75 years, 56% male, 71% white). MEASUREMENTS: All patients underwent a detailed clinical assessment, an echocardiogram, and an intravenous dipyridamole thallium stress test before hospital discharge. The study endpoint was death or nonfatal reinfarction during the follow-up period. RESULTS: Overall, 24 patients (33%) died or developed recurrent myocardial infarction during follow-up. Among 44 patients with a reversible thallium defect, 19 (43%) reached the study endpoint, compared with only five of 29 patients (17%) without reversible ischemia (P = .04). On multivariate analysis, independent prognostic variables included non-use of aspirin at hospital discharge (P = .002), decreased left ventricular systolic function (P = .009), non-use of a beta-blocker at hospital discharge (P = .013), and reversible ischemia on thallium scintigraphy (P = .025). The relative risks for death or reinfarction associated with non-use of aspirin, non-use of a beta-blocker, left ventricular dysfunction, and reversible ischemia were 2.65, 2.39, 2.01, and 2.51, respectively. Patients with three or four of these risk factors had an 83% probability of death or reinfarction, compared with 41% in patients with two risk factors and 6% in patients with one or no risk factor (P < .001). CONCLUSION: Intravenous dipyridamole thallium imaging provides independent prognostic information in older patients with acute myocardial infarction. Moreover, the combination of clinical, echocardiographic, and dipyridamole thallium variables effectively stratifies older postinfarction patients into high-, intermediate-, and low-risk categories for death or recurrent myocardial infarction.

Aged↗
PubMed1999

Characteristics of ischemic and peri-ischemic regions during ventricular fibrillation in the canine heart.

INTRODUCTION: Although premature beats originating in areas of ischemia have been shown to be important in initiating ventricular fibrillation (VF), the participation of the ischemic zone in maintenance of VF has not been investigated. METHODS AND RESULTS: Ten normal dogs underwent induction of two separate episodes of VF, before and 10 minutes after left anterior descending coronary artery ligation. Ischemic VF was allowed to occur spontaneously or was induced by burst pacing after 10 minutes of ischemia. Unipolar epicardial electrograms were recorded using an 8 x 14 plaque electrode array (interelectrode distance 2.5 mm) placed over the anterior wall. Activation during VF was characterized by VF cycle length (CL) and wavefront organization based on linking analysis of epicardial activation directions at adjacent sites. Individual plaque sites were separated into regions based on electrogram morphology during ischemia: R1 = no ischemia; R2 = mild-to-moderate ischemia (minor ST elevation and QRS widening); and R3 = severe ischemia (marked ST elevation and QRS widening). Percent conduction block was calculated based on the percent of cycles during which sites were not activated during VF. There were no significant differences noted in mean CL or mean percent conduction block in the peri-ischemic region R1 compared to the same region under nonischemic (control) conditions. During ischemia, the mean CL was noted to increase in R2 from 111+/-14 msec (control) to 128+/-29 msec (ischemia) and in R3 from 113+/-14 msec (control) to 150+/-42 msec (ischemia) (P < 0.05). The percentage conduction block in R2 increased from 6%+/-11% (control) to 14%+/-16% (ischemia) and in R3 from 4%+/-6% (control) to 44%+/-21% (ischemia) (P < 0.05). Linking analysis revealed no significant changes in VF organization at distances of 2.5 mm in regions R1 and R2 under both control and ischemic conditions. Premature beats initiating fibrillation originated at the border between the normal and mildly ischemic zones. CONCLUSIONS: (1) Some VF characteristics are altered in ischemic regions including a longer VFCL and greater percentage of functional block. (2) VF characteristics are unchanged in immediately adjacent nonischemic myocardium. (3) Although the ischemic zone may be involved in the initiation of VF and has unique activation characteristics during VF, it does not affect VF characteristics in the adjacent nonischemic zone, suggesting that it may not play a major role in VF maintenance.

Animals↗
PubMed1999

Staphylococcus capitis endocarditis: two cases and review of the literature.

Coagulase negative staphylococci are the principal cause of prosthetic valve endocarditis but are a rare cause of native valve infections. However, the incidence of native valve endocarditis is increasing. Staphylococcus capitis is a coagulase negative staphylococcus with the capacity to cause endocarditis on native heart valves. Two cases of native valve endocarditis caused by S capitis are presented; both in patients with aortic valve disease. The patients were cured with prolonged intravenous vancomycin and rifampicin and did not need surgery during the acute phase of the illness. Five of the six previously described cases of endocarditis caused by this organism occurred on native valves and responded to medical treatment alone.

Adult↗