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Biomedical subjects

V Ramesh

Publications and source records attributed to V Ramesh.

At least 199 records · Page 11Linked to original sources
PubMed1993

Deletions in the ligand for CD40 in X-linked immunoglobulin deficiency with normal or elevated IgM (HIGMX-1).

Patients with X-linked Ig deficiency with normal or elevated IgM (HIGMX-1) fail to switch from IgM/IgD to other Ig isotypes. Interaction between the B cell antigen CD40 and the CD40 ligand expressed on activated T cells is critical for T cell driven isotype switching. We have reported that T lymphocytes from three unrelated male patients with HIGMX-1 failed to express CD40 ligand on their surface, but the mRNA for CD40 ligand was of an apparently normal size and level. Analysis of CD40 ligand cDNA from two of the patients revealed deletions that alter the reading frame. Patient 1 displayed two mutations: a C-->A transversion at nucleotide 590 and the deletion of an adjacent C nucleotide. The second patient had a 58 bp deletion from nucleotides 289-346. Furthermore, neither patient expressed a protein product detectable by the CD40L mAb, 5c8.

Antibodies, Monoclonal↗
PubMed1993

Treatment of paucibacillary leprosy.

BACKGROUND: When multidrug therapy was introduced a decade ago to shorten the duration of treatment, paucibacillary leprosy was advocated 6 months of treatment. The diagnosis is based mainly on clinical and histopathologic examination, negative slit-skin smear examination, and positive lepromin test. METHODS: The case records of 508 paucibacillary leprosy patients attending our urban leprosy center have been analyzed with reference to regularity of therapy, response to multidrug regimen, follow-up, and relapse. RESULTS: The incidence of paucibacillary leprosy was found to be 37%. Defaulter rate was 45%. Nine percent of the cases attended the center with deformities emphasizing the need for corrective surgery and early case detection to prevent them. CONCLUSIONS: The main problem that we faced was the optimum duration of treatment, which is as yet an unsettled question. The opinions of other workers have been given, and a slight modification in current WHO regimen has been suggested without significantly affecting the cost of therapy.

Drug Therapy, Combination↗
PubMed1993

Post-kala-azar dermal leishmaniasis: a clinical and therapeutic study.

BACKGROUND: Post-kala-azar dermal leishmaniasis is a condition peculiarly confined to the Indian subcontinent. METHODS: The clinical features and investigations in 18 patients of post-kala-azar dermal leishmaniasis were studied. RESULTS: There was a polymorphic picture from hypopigmented macules to nodules and plaques. Mucous membranes were affected in five, the lips and glans penis being the most frequent sites. Histopathologically, a rich dermal infiltrate was seen in indurated lesions and in macules; it was confined to perivascular foci in the upper dermis. Leishman-Donovan bodies were seen in 16. CONCLUSIONS: The lesions cleared in 4 to 5 months after treatment with sodium antimony gluconate intramuscularly 20 mg/kg/day up to a maximum of 1 g/day. The drug was well tolerated.

Adolescent↗
PubMed1993

Post-kala-azar dermal leishmaniasis: a light and electron microscopic study of 18 cases.

Post-kala-azar dermal leishmaniasis (PKDL) is caused by the protozoan parasite, Leishmania donovani, and is seen in patients with history of having been treated earlier for the visceral disease form, kala-azar, caused by the same organism. The findings from 18 patients with PKDL are described in this study. The skin manifestations ranged from hypopigmented macules to infiltrated plaques and nodules. Histopathologic examination revealed a cellular infiltrate of lymphocytes, plasma cells, and macrophages. The macrophages were scattered amidst the infiltrate without any localization. In hypopigmented lesions, the infiltrate was confined to the perivascular region in the superficial dermis and was composed mainly of lymphocytes and few plasma cells. In the nodular lesions, the infiltrate occupied the entire thickness of the dermis. Leishman-Donovan bodies were scarce and identified in 16 cases after a prolonged search of Weigert's iron hematoxylin-stained sections. In 2 cases, Leishman-Donovan bodies were not demonstrable. Electronmicroscopic study revealed parasitized macrophages which showed no structural evidence of activation despite the active cellular response around them. The fine structure of the parasites in the histiocytes was also well maintained. This unusual tropical dermatosis is a unique example of change in organotropism of a parasite associated with a change in the host response.

Adolescent↗
PubMed1993

Occurrence of Duchenne dystrophy in Klinefelter's syndrome.

A boy with Duchenne muscular dystrophy and facial dysmorphism in conjunction with Klinefelter's genotype 47XXY is presented; this is an unusual situation with two genetic errors evolving over two generations. Karyotyping should be considered in boys with Duchenne muscular dystrophy who have unusual features.

Child, Preschool↗
PubMed1993

Effect of recombinant interferon gamma administration on lesional monocytes/macrophages in lepromatous leprosy patients.

Hydrogen peroxide (H2O2) and superoxide anion (O2-) were estimated in lesional cells from 10 lepromatous leprosy patients injected intralesionally with recombinant interferon-gamma (rIFN-gamma). Clinically similar contralateral lesions injected with excipient served as controls. Lesional esterase-positive cells (suggestive of monocytes/macrophages) from rIFN-gamma-injected sites of many subjects showed net increments in the H2O2 and O2 levels compared to controls. When these cells were exposed to Mycobacterium leprae in vitro, there was a down-regulation of O2- in 4 of 5 subjects. Such inhibition was not observed in rIFN-gamma-injected sites. From the present studies it was not possible to determine whether the above effects of rIFN-gamma were primarily on lesional mature macrophages or on newly migrated young monocytes. Erythema and induration were observed at the cytokine-injected site but not at the control site between 24 and 72 hr. A monthly slit-skin smear examination of the former site showed a bacterial index (BI) reduction compared to the controls in 4 of 10 patients, this reduction occurring as early as 4 to 8 weeks. Histopathology of the biopsies of 6 of 10 subjects between 9 and 10 months showed a further BI decrease attributable to rIFN-gamma and not to the subsequently instituted chemotherapy.

Adolescent↗
PubMed1992

A 15-bp deletion in exon 5 of the ornithine aminotransferase (OAT) locus associated with gyrate atrophy.

Gyrate atrophy of the choroid and retina (GA) is an autosomal recessive disorder in which a deficiency of the mitochondrial matrix enzyme ornithine aminotransferase (OAT) leads to progressive blindness. Previously, we and others have reported a number of missense mutations and splice defects in the OAT gene associated with GA. In the present case, through sequencing of the PCR amplified cDNA products, we have detected a novel 15-bp deletion within exon 5 of the OAT gene which retains the original reading frame. The deleted PCR product is the only one produced from the patient's mRNA, while mRNA from the patient's mother yields both deleted and normal length PCR products. The alternate, apparently nonexpressing OAT allele in this patient was inherited from the father, who displays only the normal length PCR product. The codon at the deletion joint remains unaltered, predicting the loss of the pentapeptide Tyr-Thr-Val-Lys-Gly without any other amino acid change. The breakpoints are adjacent to or within two copies of a 4-bp direct repeat, which may have implications for the mechanism of deletion.

Amino Acid Sequence↗
PubMed1992

Mapping of ornithine aminotransferase gene sequences to mouse chromosomes 7, X, and 3.

Ornithine aminotransferase (OAT), a mitochondrial matrix enzyme, is deficient in patients with gyrate atrophy of the choroid and retina. In human, the OAT structural gene maps to Chromosome (Chr) 10q26 and several OAT-related sequences, some of which are known to be processed pseudogenes, which map to Xp11.3-11.21. Here, we report chromosomal localization in the mouse of the OAT gene and related sequences. Genomic DNA blot analysis of a well-characterized panel of Chinese hamster x mouse somatic cell hybrids using a human OAT probe revealed two murine loci, one on mouse Chr 7 and the other on Chr X. In addition, segregation of restriction fragment length polymorphisms (RFLPs) detected by the OAT probe in recombinant inbred (RI) strains detected a third locus on Chr 3 and positioned the X locus near Cf-8 and Rsvp. Progeny of an intersubspecific backcross were used to map the Chr 7 locus between Tyr and Int-2, near Cyp2e-1.

Alleles↗
PubMed1992

Serodiagnostic value of the 19 kilodalton antigen of Mycobacterium tuberculosis in Indian patients.

Previous studies in UK subjects suggested that the 19 kDa protein antigen of Mycobacterium tuberculosis might be valuable in the serodiagnosis of paucibacillary tuberculosis. In this study, antibody titres for the 19 kDa antigen were higher in healthy controls in India than in the UK. Consequently, the diagnostic sensitivity of this antigen and its TB23 epitope was negligible in Indian patients with tuberculosis. However, a diagnostic sensitivity of 50% was achieved in patients with skin tuberculosis on the basis of a high ratio between antibody titres for the whole antigen and its TB23 epitope.

Antibodies, Bacterial↗
PubMed1992

Chronic suppression of testicular function by constant infusion of gonadotropin-releasing hormone agonist and testosterone supplementation in the bonnet monkey (Macaca radiata).

OBJECTIVE: To study the efficacy of long-term buserelin acetate infusion to desensitize pituitary and block testicular function in adult male monkeys (Macaca radiata). ANIMALS: Proven fertile male monkeys exhibiting normal testicular function. PROTOCOL: Each of the control (n = 5) and experimental monkeys (n = 10) received a fresh miniosmotic pump every 21 days, whereas pumps in controls delivered vehicle of experimentals released 50 micrograms buserelin acetate every 24 hours. On day 170 (renewed every 60 days) a silastic capsule containing crystalline testosterone (T) was implanted in the experimental monkeys. At the end of 3 years, treatment was stopped, and recovery of testicular function and fertility monitored. RESULTS: (1) Treatment resulted in marked reduction of nocturnal but not basal serum T; (2) the pituitary remained desensitized to buserelin acetate throughout the 3-year period; (3) animals were largely azoospermic with occasional oligospermia exhibited by two monkeys; and (4) withdrawal of treatment restored testicular function, with 70% of animals regaining fertility. CONCLUSION: Long-term infertility (but restorable) can be induced in male monkeys by constant infusion of buserelin acetate and T.

Animals↗
PubMed1992

Familial paroxysmal rhabdomyolysis: management of two cases of the non-exertional type.

Familial paroxysmal rhabdomyolysis with myoglobinuria is a rare and life-threatening disease of young children, of unknown aetiology. Attacks bear no relation to exercise, are usually triggered by intercurrent infections and are often severe. The authors describe two cases and suggest plans for the prevention and management of attacks. Fasting appears to be the crucial factor precipitating attacks, but is not associated with hypoglycaemia or with a defect in lactate production, ketogenesis or fatty acid mobilisation. The fatty acid-binding protein in a muscle biopsy from one case was normal.

Biopsy↗
PubMed1992

Pseudoainhum in porokeratosis of Mibelli.

Porokeratosis of Mibelli in an adult man with involvement of the skin and oral and genital mucous membranes is described. The unusual features in this case were the late onset and pseudoainhum resulting from a porokeratotic lesion in the right foot. The probable cause of pseudoainhum is reviewed.

Ainhum↗
PubMed1992

Multidrug therapy in multibacillary leprosy; experience in an urban leprosy center.

The article records the experience of treating multibacillary (BB, BL and LL) leprosy with multidrug therapy (MDT) in an urban leprosy center. The problem of leprosy is to be properly assessed throughout the Indian subcontinent because most of the epidemiological data from the areas labeled low-endemic have to be updated. The regularity of therapy must be ensured and monitored constantly, but in spite of our efforts to do so some factors were beyond our control, such as providing a means of livelihood for the migrants from other places. In addition, the intake of drugs also has to be periodically checked from the history and discoloration of skin and, most importantly, confirmed by performing random spot tests for dapsone in the urine. The main problems discussed are the difficulty in demonstrating acid-fast bacilli in slit-skin smears from the macular form of borderline leprosy (also called dimorphous macular) and, secondly, whether the duration of multibacillary therapy was adequate since only approximately 50% of our patients achieved smear negativity after taking MDT for the stipulated period of 24 months. Experiences from other centers have suggested that the duration of MDT should be prolonged in multibacillary patients to achieve smear-negative status. Yet another group notes that smear negativity is gradually achieved during the period of surveillance following stoppage of MDT after 24 months. These questions await more information from good centers with controlled field studies.

Dapsone↗
PubMed1992

Trypsin inhibitors of buffalo seminal plasma.

Two trypsin inhibitors from acid-treated buffalo seminal plasma were purified by gel filtration and affinity chromatography. These acid-stable trypsin inhibitors having charge heterogeneity were homogeneous with respect to size as revealed by gel filtration and SDS-PAGE. Gel filtration data suggest molecular weight value of 9,900 Da for inhibitor I and 10,900 Da for inhibitor II. Molecular weight estimated by SDS-PAGE was found to be 10,600 Da and 11,200 Da for inhibitors I and II, respectively. The hydrodynamic properties such as Stokes radii (1.58 nm and 1.62 nm); intrinsic viscosity (2.5725 ml/g and 2.5025 ml/g) and diffusion coefficient (13.499 x 10(-11) m2/sec. and 13.166X10(-11) m2/sec) respectively for inhibitor I and II were determined by analytical gel filtration. These inhibitors were fairly thermostable and could not be stained by PAS reagent. Both the inhibitors were found to inhibit buffalo acrosin but not bovine chymotrypsin.

Animals↗