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Biomedical subjects

S R Rao

Publications and source records attributed to S R Rao.

At least 19 recordsLinked to original sources
PubMed1996

Pollution and its control in asbestos milling processes in India.

An intervention study has been conducted in chrysotile asbestos milling processes with an interval of one year. The 'Membrane Filter Method' adopted in the former study for fiber concentration estimation has been followed in the present study, to estimate the environmental samples under the same experimental conditions. Though very high fiber levels compared to the prescribed permissible limit in India, have also been obtained in this study, a general reduction trend in the values of mills common to the both studies are observed. A further suitable control measure has been recommended in the paper to reduce fiber levels in the milling processes.

Air Pollution, Indoor↗
PubMed1994

Pilot study of sequential combination chemotherapy in advanced and recurrent retinoblastoma.

Eight patients with advanced/recurrent retinoblastomas were treated with sequential combination chemotherapy incorporating cyclophosphamide, cisplatin, adriamycin, and etoposide. All patients achieved complete clinical response (CR) at the end of the first 75 day cycle. Three patients developed recurrence of which 2 patients had recurrence in the central nervous system and 1 patient had local recurrence. Median time to treatment failure was 30 weeks. Two patients succumbed to chemotherapy related neutropenic sepsis. One patient is alive and disease free for 72 weeks from start of treatment. This combination chemotherapy shows promise in patients with advanced/recurrent retinoblastoma and merits further study.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Lactate dehydrogenase allozyme differentiation of species in the Anopheles culicifacies complex.

Genetically controlled enzyme variation exists within and between four sibling species of the Anopheles culicifacies complex of malaria vectors in India. A study on electrophoretic variation of nine enzymes in An. culicifacies sibling species revealed that the lactate dehydrogenase (Ldh) locus has Fast (F) and Slow (S) allozymes distinguishing species A+D from species B+C with a probability of c. 95%.

Animals↗
PubMed1993

Ewing's sarcoma.

Between 1984-1987, 50 patients with Ewing's sarcoma of the bone were entered on combined modality protocol at Tata Memorial Hospital. Protocol treatment involved induction therapy consisting of 6-week therapy with vincristine, Adriamycin (doxorubicin), and cyclophosphamide (VDC) followed by local radiotherapy 50 Gy to the involved bone. This was followed for six more cycles of VDC. Five patients had metastatic disease at presentation. Seventy-six percent (38/50) of patients had disease either at axial or proximal site. With a median follow-up of 48 months (range 14-87) 21 patients remained alive with disease-free survival of 38.0% +/- 2.5% at 5 years and overall survival of 36.0% +/- 2.6% at 5 years. Twenty-five patients relapsed with five patients developing local failure and four local and distant metastasis. Using Lee-Desu statistical methods, only response to therapy was a significant factor for survival. We conclude that more aggressive therapy with proper selection of local treatment modality including surgery and/or radiotherapy is required to produce more long-term survival in high-risk Ewing's sarcoma.

Actuarial Analysis↗
PubMed1993

Response with combined modality treatment in childhood rhabdomyosarcoma.

Children diagnosed with rhabdomyosarcoma at the Tata Memorial Hospital during the period January 1986-December 1988 were studied. All were treated with combination chemotherapy incorporating vincristine, Adriamycin, and cyclophosphamide given sequentially in repeated cycles over 18 months, along with local radiotherapy. Of 24 patients, 18 patients had advanced-stage disease at onset. All patients have been followed up for 18 months or more. Of the 11 patients with group III disease, six are in complete remission; of the six patients with group IV disease, two patients are in complete remission. These results are clearly better than those achieved in the past, where surgery was employed as the primary modality of therapy with chemoradiotherapy given only for patients with group IV disease.

Adolescent↗
PubMed1993

Rhabdomyosarcoma. A cytogenetically interesting case report.

Chromosomal analysis was performed on the tumor tissue in a case of ocular rhabdomyosarcoma. Cytogenetic analysis revealed multiple clonal abnormalities. Derivative(5)t(1;5)(q21;q35) and t(2;11) (q21;q23) were present in all the metaphases analyzed (100%). Translocation(1;19)(q21;q13) was observed in 61% of the metaphases. Other clonal abnormalities present included +i(6p)(85%),i(17q)(38%),18q+(57%), 4p+ (38%), loss of the Y chromosome (33%), and presence of double minutes (12.8%).

Child, Preschool↗
PubMed1993

L-asparaginase related hyperglycemia.

L-asparaginase is a valuable chemotherapeutic agent used in the induction of remission and improvement of long term survival in patients with acute lymphoblastic leukemia. Hyperglycemia is a well known side effect of L-asparaginase. Fourteen patients developed hyperglycemia during induction therapy of acute lymphoblastic leukemia with L-asparaginase, prednisolone, vincristine and daunorubicin. Hyperglycemia was observed after a mean of five doses of L-asparaginase (range 2-10). Seven of fourteen patients had neutropenic related infective episodes. Hyperglycemia resolved in all patients within 12 days (range 4-25) and two patients died of neutropenic septicemia. During reinduction therapy with the same drugs, only one out of ten patients developed hyperglycemia E-coli-L-asparaginase was replaced by Erwinia asparaginase in two patients one of who had recrudescence on further therapy. Close monitoring during L-asparaginase therapy for hyperglycemia will enable prompt recognition and early correction and prevent delay in therapy of acute lymphoblastic leukemia.

Adolescent↗
PubMed1993

Infantile neuroblastoma: 10 year TMH experience.

The results of 19 children with neuroblastoma under one year of age treated at the Tata Memorial Hospital between 1981-1990 were analysed. Biologically, neuroblastomas in children under the age of 12 months have an entirely different prognosis as compared to older children. There were four children less than six months of age and 15 children between six and 12 months. All patients with stage II (2/2) disease are alive; 3/4 patients with stage IV-S disease are disease free; 3/5 stage III patients are disease free and 2/8 patients with stage IV disease are disease free. The survival of infants with stage II and IV-S is better than for those with stage III and IV disease.

Female↗
PubMed1992

An environmental survey in chrysotile asbestos milling processes in India.

Environmental monitoring to determine airborne asbestos fiber levels has been carried out in four different mills processing chrysotile asbestos in the Cuddapah District (Andhra Pradesh) of India. The "membrane filter method" comprising standard asbestos sampling techniques, acetone-triacetin method for sample preparation, fiber counting, and sizing using the phase contrast optical microscope were adopted in the study. Fiber concentrations both with respect to personal exposures and processing areas were found in most of the cases to be much higher than the prescribed Threshold Limit Value (TLVs) of the developed and developing countries for chrysotile asbestos. By optical microscopy, fiber length distribution showed 70% of fibers in the milling processes were in size range > 5-10 microns, whereas in > 10-20 and > 20 microns, 20% and 8%, respectively. Fiber identification for major elemental content, also done by using scanning electron microscope equipped with an energy dispersive X-ray analyzer, indicated the presence of tremolite along with chrysotile. The study stresses the urgent need to adopt suitable engineering controls at the dust generating sources to reduce the fiber level in the mill environment below the threshold limit.

Air Pollutants, Occupational↗
PubMed1992

Assignment of 6-phosphogluconate dehydrogenase and malate dehydrogenase to chromosome 3 of Anopheles stephensi.

Genetics and linkage analysis of 6-phosphogluconate dehydrogenase (6-PGD) and malate dehydrogenase (MDH) have been investigated in Anopheles stephensi. Both these markers were found to be autosomal and linked and have been assigned to linkage group III. Two mutant markers, Black larva (Bl) and golden-yellow larva (gy), were used to establish the map distances, and the current sequence of loci on chromosome 3 is as follows: Bl (3.75)-gy (14.53)-Mdh-2 (49.83)-6-pgd.

Animals↗
PubMed1992

Insect sex chromosomes, XI. 3H-TdR induces random aberrations in the X chromosome(s) of Gryllotalpa fossor (Orthoptera).

The pattern of titrated thymidine (3H-TdR), a direct precursor of DNA, induced aberrations on the X chromosome of Gryllotalpa fossor was examined. 3H-TdR produced aberrations randomly distributed over the entire length of the X chromosome; breaks were observed in both the eu- and the heterochromatic arms of the X chromosome in both the sexes. Since the eu- and the heterochromatic arms cannot be distinguished cytologically in this insect, the presence of aberrations on both arms of the same X chromosome in the male and damage to both X chromosomes in the female indicate that both euchromatic and heterochromatic regions (facultative or constitutive) are equally liable to aberrations induced by H-TdR. This is in contrast to the non-random induction of aberrations by 3H-UdR, which causes chromosome damage due to the proximity of the labeled RNA to the DNA template during transcription.

Animals↗
PubMed1992

Aniridia--Wilms' tumour association--a case with 11p 13-14.1 deletion and ventricular septal defect.

A two year old female child with bilateral wilms tumor (WT) along with multiple congenital anomalies like bilateral aniridia with congenital cataracts and nystagmus, microcephaly, mental retardation and ventricular septal defect has been described. The karyotype analysis revealed 46 xx, del 11p 13-14.1. Association of ventricular septal defect with the classical features of 'Aniridia-Wilms' tumor association' is an unusual feature in this case.

Aniridia↗
PubMed1991

Random/nonrandom X-chromosome inactivation in Nesokia indica: possible influence of heterochromatin.

Five types of X chromosomes with different amounts of heterochromatin have been observed in Nesokia indica, the Indian mole rat. They have been found in both mosaic and nonmosaic individuals. The influence, if any, of heterochromatin on the kinetics of X-chromosome DNA replication was evaluated in bone marrow cells and peripheral blood lymphocytes of Nesokia females with variant X chromosomes. In bone marrow cells of nonmosaic females a random X-chromosome inactivation (XCI) pattern was observed, except when there was a total loss of heterochromatin from the variant X chromosome, resulting in predominantly early replication. A nonrandom pattern was observed, however, in blood and bone marrow cells of all individuals with mosaic genotypes. In these females the X chromosome with the lesser amount of heterochromatin was predominantly the active one. The amount of heterochromatin per se or, more likely, specific sequences contained in the heterochromatic region seem to influence the XCI pattern in a cis-acting manner. The observations also seem to support a process of cell selection in individuals with variant X chromosomes.

Animals↗
PubMed1991

Replication status of the fragile X chromosome and its implications for reproductive performance in the Indian mole rat (Nesokia indica).

In all fertile females the fragile X chromosome was almost always late replicating (inactive) in an average 82% of cells whereas in infertile females, it was early replicating (active) in about the same percentage of cells. These observations strongly suggest a correlation between the replication (activity) status of the fragile X chromosome and reproductive performance.

Animals↗
PubMed1991

Cerebrospinal dehydrogenases in central nervous system infections.

Cerebrospinal fluid (CSF) dehydrogenases were studied in 42 controls, 23 children with pyogenic meningitis, 22 with tuberculous meningitis and 19 with encephalitis to assess their usefulness in differentiating between the different central nervous system infections. CSF-LDH and ICD activity was increased in CNS infections (p less than 0.0001), LDH being significantly higher (p less than 0.001) in pyogenic meningitis than in tuberculous meningitis or encephalitis. However, ICD activity was significantly different in each of these conditions (p less than 0.001). The dehydrogenase activity declined with subsequent clinical improvement, in all children with meningitis. A significant direct relationship was found between the enzyme activity and CSF protein content as well as total cell count. The 95% confidence interval confirms the utility of assaying CSF dehydrogenase activity to differentiate various CNS infections, thus improving the diagnostic ability.

Acute Disease↗
PubMed1991

Fanconi's anemia: a clinico-hematological and cytogenetic study.

Eleven patients with typical features of Fanconi's anemia with cytogenetic studies were evaluated. Cytogenetic abnormalities was seen in all but one patient. Two patients had acute non-lymphoblastic leukemia (ANLL) and nine had Fanconi's anemia (FA). All patients with FA responded to oxymetholone and are well with a median follow up of 38.6 months. Both patients with ANLL died. This study stresses the need of an accurate cytogenetic analysis in FA patients along with a clinicohematological correlation.

Abnormalities, Multiple↗