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Biomedical subjects

S Prasad

Publications and source records attributed to S Prasad.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Treatment of visceral leishmaniasis (kala-azar) with aminosidine (= paromomycin)-antimonial combinations, a pilot study in Bihar, India.

A 20 d drug regimen of aminosidine (= paromomycin) at 12 mg/kg/d in combination with sodium stibogluconate at 20 mg/kg/d proved efficacious and well-tolerated in patients with visceral leishmaniasis in the State of Bihar, India. Eighteen of 22 evaluable patients achieved an ultimate cure. The remaining 4 patients, although not cleared of parasites, had their parasite grade reduced and also improved clinically. This confirms prior findings in Kenyan patients with kala-azar, and indicates that this regimen is a valid alternative to antimonial compounds alone in the State of Bihar, where cases of kala-azar not responding to antimonial drugs and intolerant of pentamidine are increasingly recorded.

Adolescent↗
PubMedDate not supplied

Effects of spermine and sodium butyrate on the in vitro phosphorylation of HMG non-histone proteins of the liver of young and old rats.

The in vitro phosphorylation of high mobility group (HMG) proteins and its modulation by spermine and sodium butyrate were studied in the liver of young (15 week) and old (138 week) male rats. Except HMG 1 which remained unchanged, the phosphorylation of other proteins (HMG 2, 14 and 17) decreased drastically in old age. Spermine stimulated the phosphorylation of HMG 1 and 17 in young but HMG 1, 2 and 14 in old rats. The incorporation of (32)P into total HMG proteins was enhanced by butyrate in the liver of both ages. However, the degree of stimulation was higher in young rats. Particularly, the HMG 1 and 17 of young and HMG 2 and 17 of old rats showed increased phosphorylation. Furthermore, butyrate also inhibited the phosphorylation of HMG 2 in young and HMG 1 and 14 in old rats. Such alteration in the phosphorylation of major HMG proteins modulates their interaction with DNA and other components of chromatin. This may account for changes in the higher order organization of chromatin and expression of genes during aging.

Journal Article↗
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Preservation of vestibular nerves in surgery of the cerebellopontine angle: effect on hearing and balance function.

INTRODUCTION: Small tumors of the cerebellopontine angle (CPA) can frequently be removed with preservation of the auditory and the vestibular portion of the eighth cranial nerve. This study was undertaken to estimate the effect of vestibular nerve preservation on both balance and hearing following surgery. MATERIALS AND METHODS: A retrospective study of all cases of CPA lesions between 1987 and 1991 was undertaken. This identified 11 patients in whom either the superior and/or inferior vestibular nerves were preserved. This included eight acoustic neuromas and three meningiomas. The retrosigmoid approach and total tumor extirpation was undertaken in all cases. Patients undertook a vestibular questionnaire, audiometric testing, and evaluation of vestibulo-ocular responses preoperatively and postoperatively. Additionally, static and dynamic platform posturography was performed postoperatively in 9 of 11 patients. RESULTS: Follow-up ranged from 6 to 44 months. Of the eight patients with acoustic neuroma, four had a preoperative balance disorder that resolved postoperatively. One patient died of unrelated causes. Of the remaining seven patients with caloric testings, one maintained normal caloric responses. A persistent postoperative phase shift was noted in 4 of the 7 cases with rotatory testing. Three patients were treated for a meningioma. All had a preoperative balance disorder that resolved postoperatively. Two patients showed vestibular response indicative of residual but compromised function on the involved side. The third patient showed absent responses indicating an anatomically intact nerve that does not necessarily predict functional activity. Preservation of the vestibular nerve was associated with preservation of preoperative hearing in five of the patients. This included four of the eight acoustic patients and one of the three meningioma patients. CONCLUSIONS: Preservation of the vestibular nerve did not result in a chronic balance disorder in this patient population. This study does not allow the authors to conclude if vestibular nerve preservation improves overall hearing after CPA surgery; however, these data suggest that preservation of the inferior vestibular nerve may result in less damage to the cochlear nerve in some patients. Accordingly, preservation of the vestibular nerve in CPA meningioma surgery can be recommended.

Adult↗
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The ovary as an immune target.

The ovary does not have a distinct morphologic barrier between the immune system and the developing gametes. This is in contrast to the testis in which the junctional complexes between the Sertoli cells form the blood-testis barrier. Whereas there are numerous factors, including genetic ones, associated with ovarian dysfunction, the immune factors have frequently been implicated in ovarian dysfunction. Much of our knowledge used to evaluate the immune system of the ovary has come from studies on the expression of the zona pellucida (ZP) proteins during ovarian development. Initial studies by Dunbar and colleagues demonstrated that immunization of rabbits with porcine ZP proteins (but not rabbit ZP proteins) would result in the generation of antibodies that inhibit sperm binding to the ZP and interfere with normal ovarian follicular development. In contrast to the rabbit and primate models, immunization of mice or rats with porcine ZP proteins does not have an effect on fertility or ovarian function although immunization of certain strains of mice with mouse ZP peptides and immune activator systems has been shown to result in ovarian pathology. Whereas immune inflammatory reactions have been observed in the mouse models, no such immune reactions have been observed in rabbit, guinea pig, or nonhuman primate models. Subsequent observations in nonhuman primates have shown that immunization of primates with ZP proteins expressed from cDNAs coding for the mouse and rabbit ZP2 (the mouse homologue has 60% amino acid identity with human ZP2) or the mouse ZP3 (the mouse protein has 67% amino acid identity with human ZP3) causes ovarian dysgenesis. In contrast, immunization of primates with recombinant rabbit ZP1 protein (the mouse homologue has 39% amino acid identity with human ZP1) does not affect nonhuman primate ovarian function or follicular development but will elicit antibodies that inhibit sperm binding to the primate ZP. These studies have collectively provided important information concerning the immunologic status of the ovary and demonstrate the species variations in immune responses to different ovarian immunogens.

Animals↗
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Craniovertebral junction tuberculosis: a review of 29 cases.

PURPOSE: The purpose of this work was to describe the various imaging findings in craniovertebral tuberculosis and the importance of imaging in treatment in these patients. METHOD: A retrospective review of MR and CT scans in 29 patients with craniovertebral tuberculosis was performed. The images were reviewed, paying special attention to both bony (skull base, atlas, and axis) and soft tissue involvement in addition to atlantoaxial dislocation, lateral subluxation of the dens, and compression of the spinal cord. RESULTS: Suboccipital pain with neck stiffness was the most common presenting symptom in our patients. The skull was involved in 19 of the 29 cases, clivus involvement was seen in 11 patients, and occipital condyle involvement was present in 14 patients. Detailed analysis of atlas involvement due to tuberculosis showed the lateral masses to be predominantly affected. The dens was involved in 18 cases (62%). Soft tissue masses in the prevertebral area were seen in 22 patients, paravertebral in 27 patients, and epidural involvement in 25 patients was identified. Atlantoaxial displacement was present in seven cases, lateral mass-dens subluxation in five, and superior subluxation of the dens through the foramen magnum compressing the medulla was seen in two cases. Spinal cord compression with intrinsic cord changes was noted in 12 cases. All patients received multidrug antituberculous therapy for 1 year. The presence of neurologic deficit and instability of the atlantoaxial complex was pivotal in further management in these patients. CONCLUSION: A high degree of clinical suspicion is necessary when confronted with patients with neck stiffness and tenderness over the upper cervical vertebrae. MRI in these patients provides a sensitive method for the diagnosis of craniovertebral tuberculosis.

Abscess↗
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Prevalence of Helicobacter pylori in southern Indian controls and patients with gastroduodenal disease.

The spiral organism Helicobacter pylori has been causally implicated in the genesis of various gastroduodenal diseases. Since these diseases are common in southern India, this study was undertaken to determine the prevalence of H. pylori in the gastric mucosa of asymptomatic adults and patients with various gastroduodenal diseases. H. pylori was detected in the gastric mucosa of 25 of 30 (83.3%) normal volunteers. Prevalence rates in the disease groups were also high, and included 38 of 41 patients with duodenal ulcer (92.6%), 13/16 with gastric ulcer (81.3%), and 85/119 subjects (71.4%) with non-ulcer dyspepsia. Light microscopic examination of the gastric mucosa provided the best method of detecting H. pylori. H. pylori colonization was significantly associated with histological abnormalities, mainly chronic atrophic gastritis (147) and superficial gastritis (11), while only three of 161 H. pylori positive patients had histologically normal antral mucosa. Ultrastructural examination revealed changes in the apical complex of the gastric mucosal cells in response to bacterial adhesion, with mucus depletion and cellular damage. Bacteria were also noted disrupting the tight junctions and entering the intercellular spaces. The high prevalence of H. pylori infection may explain the high incidence of gastritis, duodenal ulceration and gastric carcinoma in this population. However, in this population, the prevalence of infection in asymptomatic individuals was nearly as high as that in duodenal ulcer, underlining the need for further study to identify the differences in host response or bacterial pathogenicity that lead to the development of ulcer in only some individuals.

Adolescent↗
PubMedDate not supplied

Congenital ranula. A report of two cases.

We report 2 unusual cases of congenital ranula in male Nigerian infants. Clinical examination could not discern the orifice of the submandibular duct on the affected sides, while a lower occlusal radiograph revealed no obvious calculi. Diagnosis was mainly by clinical presentation. The paper highlights possible aetiopathogenesis, clinical aspects and diagnostic features. Emphasis is laid on the need for careful evaluation of oral ranulas in order to discern their origin and provide appropriate treatment.

Child, Preschool↗
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Bilateral anterior ischaemic optic neuropathy due to optic disc drusen.

PURPOSE: To report a case of bilateral anterior ischaemic optic neuropathy due to buried optic disc drusen. METHODS: Case report. RESULTS: A 64-year-old man presented with swollen optic discs and features suggestive of anterior ischaemic optic neuropathy (AION) in the left and right eye on two separate occasions ten months apart. Detailed ocular examination at presentation and systemic investigations did not reveal an underlying cause for the AION. At a later follow-up, optic disc drusen were noted in both eyes as partial optic atrophy had set in. This was confirmed by ultrasound B scan and demonstration of autofluorescence. CONCLUSIONS: In patients presenting with AION uncommon underlying causes must be considered. Routine ultrasound B scan at presentation can easily establish or exclude optic disc drusen as an underlying cause.

Fluorescein Angiography↗
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Choroidal effusion and hypotony caused by severe anterior lens capsule contraction following cataract surgery.

PURPOSE: The case report describes a case of severe anterior capsular contraction associated with choroidal effusion. CASE REPORT: An 81 year old female with primary open angle glaucoma underwent routine phacoemulsification cataract surgery. Eight weeks following surgery the anterior capsule opening had reduced to 3 mm in size. Intraocular pressure was found to be 4 mmHg and B scan ultrasound revealed a large choroidal effusion. Anterior capsulotomy with Nd:YAG laser was performed. At review, two weeks later, the choroidal effusion had resolved and visual acuity had recovered. DISCUSSION: The Nd:YAG laser radial relaxing capsulotomies helped relieve the capsular contraction and associated traction on the ciliary body.

Aged↗
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Spontaneous isolated lesser sac hematoma in a patient with hemophilia.

In patients with hemophilia, hematomas in the mesentery and bowel wall have been described uncommonly. The lesser sac is a rare site of spontaneous hemorrhage even in patients with bleeding diathesis; only a single case of isolated lesser sac hemorrhage has been reported in a hemophiliac patient. We report a similar case with no history of trauma. He recovered with administration of factor VIII concentrate.

Child↗
PubMedDate not supplied

Primary linitis plastica of the rectosigmoid in a thirteen year old boy.

Childhood malignant neoplasms of the gut are extremely rare. The reported incidence of colorectal cancers in patients under 20 years of age is 1 in 10 million. The low index of suspicion for this tumour in children results in advanced disease at diagnosis and subsequently a poor prognosis. A rare case of a primary linitis plastica of the rectum occurring in a 13 year old boy is reported with review of pertinent literature.

Adolescent↗