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P C Sekharan

Publications and source records attributed to P C Sekharan.

18 recordsLinked to original sources
PubMed1994

Red cell enzymes and serum protein polymorphisms in three population groups of south India.

Blood and serum samples from random individuals of three populations in south India, the first being an endogamous group from the Nilgiri hills (Tamil Nadu), the second from the Shevroy hills (Tamil Nadu), and the third from a semi-urban area of Tamil Nadu, were screened for ESD, GLO1 and Hp polymorphisms. The allelic frequencies for these markers have been estimated. High GLO1*1 (0.379) frequency was observed in the tribal Malayalis, in contrast with other Indian population groups.

Alleles↗
PubMed1992

Novel solid-state fluorodensitometric method for the determination of haptens in protein-hapten conjugates. Demonstration with a toxic glycoside of Cleistanthus collinus.

A method is reported for the solid-state fluorodensitometric determination of haptens in hapten-protein conjugates. The applicability of the method is shown using the bovine serum albumin conjugate of cleistanthin B, a toxic glycoside of the plant Cleistanthus collinus. This non-destructive technique, which is relatively simple, sensitive, rapid and versatile, can be used for the determination of protein conjugates of fluorogenic haptens.

Chromatography, Thin Layer↗
PubMed1992

Remote control skull positioning device for superimposition studies.

The success of the superimposition technique requires positioning the skull in the same posture of the face as seen in the given photograph. A scientific method for positioning the skull has already been proposed by Sekharan. This paper deals with the simple remote control tilt and rotatory device developed in the Forensic Sciences Department, Madras. A pan and tilt arrangement usually utilized in surveillance cameras and two a.c. servomotors, one to tilt the pan and the other to rotate the pan are used.

Forensic Medicine↗
PubMed1992

Enzyme-linked immunosorbent assay (ELISA) for the determination of the toxic glycoside cleistanthin B.

Cleistanthus collinus is a highly toxic plant frequently implicated in suicidal and homicidal poisoning cases referred to our laboratory. An enzyme-linked immunosorbent assay (ELISA) is reported in this paper for the quantitation of the active principles of C. collinus. This method is highly reproducible and sensitive to detect as low as 2 ng/ml of cleistanthin B, a toxic constituent of C. collinus. The ELISA can be successfully applied for the specific identification of C. collinus poisoning in clinical and forensic toxicology.

Animals↗
PubMed1992

Enzyme-linked immunosorbent assay for the phytotoxin cleistanthin A.

Enzyme-linked immunosorbent assay is reported for the estimation of cleistanthin A, a major constituent of the toxic plant Cleistanthus collinus. Rabbit antibodies were obtained by immunisation with cleistanthin A hemisuccinate-BSA conjugate and the ELISA developed thereupon could detect cleistanthin A at as low a concentration as 3 ng/ml. Cross-reactivity studies with structural analogs as well as with other phytotoxins and drugs of common occurrence established the suitability of the ELISA to specifically monitor the C. collinus marker molecules in emergency clinical and forensic cases. The simplicity and specificity make the ELISA superior to the other available techniques.

Cross Reactions↗
PubMed1991

Polymorphism of esterase D and haptoglobin in the Madras City population.

Blood and serum samples from random individuals of Madras City, South India, were screened for ESD and HP polymorphisms using mixed starch agarose gel electrophoresis and polyacrylamide slab gel electrophoresis respectively. The allelic frequencies for HP*1 and HP*2 in Madras are 0.1240 and 0.8760 respectively, while ESD*1 and ESD*2 gene frequency estimates were 0.7680 and 0.2320 respectively. The results are compared with those available for other Indian and world populations.

Carboxylesterase↗
PubMed1990

Studies of association between some genetic systems (ABO, MN, EsD, GLO, C3 and Hp).

Using random population data on the ABO, MN, esterase D (EsD), glyoxalase I, complement (C3) and haptoglobin markers in the population of Madras City associations were studied between these genetic systems. Out of a total of fifteen comparisons one significant association (chi 2 = 11.0; d.f. 4; 0.05 greater than p greater than 0.02) was found between the EsD and C3 phenotypes.

ABO Blood-Group System↗
PubMed1989

Barbiturate analysis in tissue by enzymic digestion and high-performance liquid chromatography.

The relative efficiencies of four enzymic digestion procedures and two conventional methods in releasing barbiturates from spiked liver tissue have been compared. The recoveries of these acidic drugs obtained by using papain and neutrase (neutral proteinase from Bacillus subtilis) digestion methods reported now for the first time are higher than those by other enzymatic and conventional methods. These observations are similar to our earlier data on the applicability of these two enzymes to the release of some basic drugs from tissue. Papain digestion gives the maximum recovery of drugs as monitored by HPLC and is the method of choice. The enzymic digestion procedures are relatively simple, inexpensive and yield reproducible results. Analytical procedures for use in routine forensic toxicological analysis are presented.

Barbiturates↗
PubMed1988

Isolation of alkaloids and glycosides from tissue following enzymic digestion.

Four enzymic digestion methods have been evaluated for their efficiency in releasing certain alkaloids and glycosides from spiked liver tissue. Enzymic digestion gives better recoveries of all the plant poisons studied than those obtained by conventional methods. A flow diagram for the enzymic methods of drug isolation and quantitation by HPLC is presented. Enzymic digestion for the release of glycosides is reported for the first time. It is concluded that papain digestion is the most suitable method for the analysis of broad spectrum of compounds of forensic and clinical importance.

Alkaloids↗
PubMed1988

Distribution of HLA antigens in the native South Indian Tamil Hindus.

Blood samples from 240 unrelated healthy Tamil-speaking South Indian Hindus residing in Madras (capital city of Tamil Nadu, India) were screened for HLA-A and -B antigen profiles. Antigen, gene and haplotype frequencies were calculated and compared with the literature. Tamil Hindus lack A31, A32, Aw33, B16, B21 and Bw41. However, except for minor differences (low occurrence of Aw19 antigen), the South Indians show similarity to North Indian and other Indian groups. The data confirm once more that the haplotype A1-B17 is characteristic of Indians.

Ethnicity↗
PubMed1988

C3 polymorphism in Kotas and Badagas of Nilgiri Hills, south India.

Blood serum samples from Kota (n = 95) and Badaga (n = 113) groups of the Nilgiri Hills, South India, were screened for C3 polymorphism using polyacrylamide slab gel electrophoresis. The distribution of the three common phenotypes F, FS and S and a variant phenotype is reported. Two deficient individuals, one per subsample, have been found. The allelic frequencies for C3*F and C3*S in Kotas and Badagas are 0.1075, 0.8925 and 0.0982, 0.9018 respectively. The results are discussed in the light of available literature on C3 polymorphism in other Indian populations.

Alleles↗
PubMed1987

Polymorphism of human salivary amylase in the Madras city population.

Polymorphism of human salivary amylase has been studied in the Madras city (South India) population using discontinuous polyacrylamide slab gel electrophoresis. Screening of random (n = 307) and family (n = 51) samples has revealed the presence and distribution of common and variant phenotypes of this enzyme. The occurrence of electrophoretic and isoelectric focusing phenotypes is compared with those of other populations.

Adolescent↗
PubMed1987

Glyoxalase-I and esterase D polymorphisms in Kotas and Badagas of Nilgiri Hills, south India.

Blood samples from 217 unrelated individuals belonging to two endogamous populations, Kotas and Badagas of the Nilgiri Hills, South India, were screened for glyoxalase I and esterase D polymorphisms using mixed starch-agarose gel electrophoresis. The GLO1*1 gene frequency estimates were 0.1887 and 0.1982 for Kotas and Badagas. The ESD*1 gene frequency estimates were 0.7123 and 0.7568 for Kotas and Badagas, respectively. The results are compared with those available for other Indian populations.

Carboxylesterase↗
PubMedDate not supplied

Comparative evaluation of some enzymic digestion procedures in the release of basic drugs from tissue.

The relative efficiency of four enzymic-digestion procedures in the release of eight basic drugs from tissue has been studied. Enzymes employed include: subtilisin Carlsberg, trypsin, papain, and neutrase. The results obtained on recovery show that papain digestion gives highest recovery for most of the drugs studied. Papain is suggested as the enzyme of choice. The application of neutrase, a neutral proteinase from B. subtilis, is reported for the first time.

Animals↗
PubMedDate not supplied

Spectrofluorometric determination of the toxic constituents of Cleistanthus collinus.

Spectrofluorometric quantitation of a lignan lactone, diphyllin, and its glycosides cleistanthin A and cleistanthin B, the active principles of the poisonous plant Cleistanthus collinus, is reported for the first time. Thin layer chromatographic resolution of the components precedes the fluorometric measurements. The method is highly reproducible and sensitive to 0.1 microgram/mL for diphyllin and to 1 microgram/mL for cleistanthins A and B in ethanol. The technique is employed for the assay of several biospecimens of forensic and clinical importance.

Animals↗