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Biomedical subjects

H Kaur

Publications and source records attributed to H Kaur.

At least 109 records · Page 6Linked to original sources
PubMed1992

Detection of human papilloma virus types 16 & 18 DNA in cervical lesions of Indian women using in situ hybridization.

Fifty one biopsies from women with malignant lesions of the uterine cervix and 9 biopsies fron non-malignant lesions were examined for the presence of HPV 16 and 18 DNA sequences by in situ hybridization method using 35S-labelled DNA probes. HPV 16 DNA sequences were detected in 82.4 per cent biopsies from women with malignant lesions, whereas HPV 18 DNA was detected in only 3 biopsies which were also positive for HPV 16 DNA. Two biopsies from non-malignant lesions were positive for HPV 16 DNA only. Data were also analysed according to the histologic type of cancer. It was observed that no significant correlation existed between HPV types and different histologic types of cervical cancer.

DNA Probes, HPV↗
PubMed1992

3NTPT: a newly discovered antifertility agent. V. Ovarian dysfunction in Dysdercus koenigii.

A 4 h exposure to a residual film of 15 mg 1-(3-nitrophenyl)-4,4,6-trimethyl-1H,4H-pyrimidine-2-thiol (3NTPT) dissolved in 5 ml acetone significantly inhibited ovarian growth in Dysdercus koenigii. The ovaries of treated females remained small and the trophocytes, the trophic core, the prefollicular tissue and the oogonia completely degenerated. This was followed by degenerative changes in the follicular epithelium, the interfollicular tissue and the developing oocytes. Resorption of the oocytes reduced the vitellarium to an empty tube. The follicular epithelium of the resorbed oocytes protruded into the lumen, while the interfollicular tissue completely degenerated. By day 7 after treatment, the ovaries were completely dystrophic, and this state was not reversible.

Animals↗
PubMed1991

Hydroxylation of salicylate by microsomal fractions and cytochrome P-450. Lack of production of 2,3-dihydroxybenzoate unless hydroxyl radical formation is permitted.

Attack by hydroxyl radicals (.OH) upon salicylate (2-hydroxybenzoate) leads to formation of both 2,3-dihydroxybenzoate (2,3-DHB) and 2,5-dihydroxybenzoate (gentisate, 2,5-DHB). It has been suggested that formation of 2,3-DHB from salicylate is a means of monitoring .OH formation. Production of 2,3-DHB and 2,5-DHB by liver microsomal fractions and isoforms of cytochrome P-450 was investigated. Liver microsomes prepared from variously treated rats and rabbits catalysed the formation of 2,5-DHB but not 2,3-DHB. Formation of 2,5-DHB was inhibited by CO, metyrapone and SKF-525A, but not by the .OH scavengers mannitol and formate or by the iron chelator desferrioxamine. Purified P-450s IIE1, IIB4 or IA2 from rabbit liver microsomes, reconstituted together with NADPH-cytochrome P-450 reductase, led to formation of equal amounts of 2,3-DHB and 2,5-DHB in reactions that were almost completely inhibited by mannitol or formate. Addition of Fe3+/EDTA either to microsomes or to membranes containing reconstituted P-450 caused formation of approximately equal amounts of 2,3-DHB and 2,5-DHB, consistent with an .OH-dependent attack on salicylate. The data indicate that the microsomal P-450 system catalyses hydroxylation of salicylate to 2,5-DHB, but not formation of 2,3-DHB. Hence measurement of 2,3-DHB might provide a means of monitoring .OH formation. Care must be taken in studies of substrate hydroxylation by microsomes or reconstituted P-450 systems to avoid artefacts resulting from .OH generation.

Animals↗
PubMed1991

Brief communication: coracoclavicular joint in Northwest Indians.

The incidence of an articular facet on the conoid tubercle of the clavicle indicating the presence of a coracoclavicular joint was studied in paired clavicles obtained from 1,000 adult subjects aged 18 to 95 years (748 males, 252 females), and 75 children (45 males, 30 females) of known age on whom a medicolegal postmortem had been performed by the second author during 1972-90. The subjects were inhabitants of northwest India. In addition, paired clavicles from 50 neonates and 35 fetuses were also examined. The facet was absent in the fetuses, neonates, and young children. The youngest clavicle showing the facet was from a girl of 13 years, in which it was present bilaterally. In adults the incidence of the facet was 10.1% (bilateral 5.7%, unilateral 4.4%) in males and 8.3% (bilateral 3.6%, unilateral 4.8%) in females. Absence of the facet in the fetuses, neonates, and young children shows that it is not a congenital anomaly.

Adolescent↗
PubMed1991

Oxygen free radicals and human diseases.

Free radicals and other reactive oxygen species are constantly formed in the human body. Many of them serve useful physiological functions, but they can be toxic when generated in excess and this toxicity is often aggravated by the presence of ions of such transition metals as iron or copper. Excess generation of reactive oxygen species within tissues can damage DNA, lipids, proteins and carbohydrates. Which of these is the most important target of damage depends upon the cell type subjected to the oxidative stress and upon how it is imposed.

Arthritis, Rheumatoid↗
PubMed1991

Dd-antigen-antibody system in five caste groups in north India.

Antigen Dd, a polymorphic antigen found in extracts of certain human dandruff specimens, was investigated in five caste groups of north India. The incidence of antigen Dd-positive type varied from 21.21 per cent in Brahmins to 29.08 per cent in the Jat Sikhs of Punjab. However, a high frequency (45%) was observed in the Sunni Muslims of Kashmir, which differed significantly, when compared with different caste groups of Punjab. Family studies on 44 families indicated its inherited nature, the mode of inheritance being autosomal dominant.

Antibodies↗
PubMed1990

Age estimation from cortical index of the human clavicle in northwest Indians.

The proportion of the cortical thickness to the total diameter of the bone (cortical index) was calculated in paired clavicles obtained from 128 male and 82 female medicolegal postmortem subjects who were apparently healthy prior to their accidental death. The ages of the subjects varied from 15 to 85 years. The clavicles were cut either horizontally or parasagittally, and measurements were taken at midclavicle. From the ages of 15 to 30 years, the cortical index increased. It decreased steadily thereafter, with an initial sharp decrease in the age group 31-40 years in both sexes. After the age of 40 years, this rapid decrease in the index continued in the females, but became slow and gradual in the males. Differences between left and right sides were statistically insignificant in both sexes (P greater than 0.05). However, the sexual differences were significant (P less than 0.01) in the age groups from 41 years onwards.

Adolescent↗
PubMed1990

Action of biologically-relevant oxidizing species upon uric acid. Identification of uric acid oxidation products.

Uric acid is an end-product of purine metabolism in Man, and has been suggested to act as an antioxidant in vivo. Products of attack upon uric acid by various oxidants were measured by high performance liquid chromatography. Hypochlorous acid rapidly oxidized uric acid, forming allantoin, oxonic/oxaluric and parabanic acids, as well as several unidentified products. HOCl could oxidize all these products further. Hydrogen peroxide did not oxidize uric acid at detectable rates, although it rapidly oxidized oxonic acid and slowly oxidized allantoin and parabanic acids. Hydroxyl radicals generated by hypoxanthine/xanthine oxidase or Fe2(+)-EDTA/H2O2 systems also oxidized uric acid to allantoin, oxonic/oxaluric acid and traces of parabanic acid. Addition of ascorbic acid to the Fe2(+)-EDTA/H2O2 system did not increase formation of oxidation products from uric acid, possibly because ascorbic acid can 'repair' the radicals resulting from initial attack of hydroxyl radicals upon uric acid. Mixtures of methaemoglobin or metmyoglobin and H2O2 also oxidized uric acid: allantoin was the major product, but some parabanic and oxonic/oxaluric acids were also produced. Caeruloplasmin did not oxidize uric acid under physiological conditions, although simple copper (Cu2+) ions could, but this was prevented by albumin or histidine. The possibility of using oxidation products of uric acid, such as allantoin, as an index of oxidant generation in vivo in humans is discussed.

Allantoin↗
PubMed1990

An evaluation of the antioxidant and potential pro-oxidant properties of food additives and of trolox C, vitamin E and probucol.

The food additives propyl gallate and vanillin inhibited iron ion-dependent lipid peroxidation in rat-liver microsomes, but stimulated formation of a deoxyribose degrading species, probably hydroxyl radical, from ferric-EDTA and hydrogen peroxide. Propyl gallate accelerated DNA damage by the anti-tumour antibiotic bleomycin, although vanillin did not. The water-soluble vitamin E analogue Trolox C also stimulated bleomycin-dependent DNA damage, but not hydroxyl radical generation from ferric-EDTA and H2O2. Indeed, Trolox C was found to be a powerful scavenger of hydroxyl radical (rate constant greater than 10(10) M-1s-1). Probucol did not stimulate oxidative damage in any of the systems tested, and is a powerful inhibitor of lipid peroxidation in rat liver microsomes. The ESR spectrum of the radical produced by one electron-oxidation of probucol in ethanol is described.

Animals↗
PubMed1989

Time of fusion of the human sternebrae with one another in northwest India.

The time of fusion of the sternebrae with one another was studied in sterna obtained from cadavers of 806 male and 212 female adults and 66 male and 29 female children, on whom medicolegal postmortem examinations had been conducted by the senior author. Sterna of 31 neonates were also studied. The bones were X-rayed in an anteroposterior view and later macerated, cleaned, and dried. The sternebrae fused with one another from below upwards. In both sexes, the third and fourth sternebrae showed partial or commencement of fusion in a majority of specimens in the 0-5 years age group. Although the earliest complete fusion was seen in the 6-10 years age group, 100% specimens exhibited complete fusion in the 15-17 years age group. The earliest complete fusion between second and third sternebrae was observed in the 11-14 years age group in both sexes; it was seen in 100% of specimens in males over 25 years and in females over 30 years. The first and second segments showed earliest complete fusion in a boy of 16 years and in a girl of 18 years; 100% of specimens showed complete fusion in the males over 60 years and in the females over 30 years. A mesosternum showing complete fusion of all the sternebrae must be from a subject over 16 years of age if male and over 18 years if female. These observations are at variance with those of workers in Western countries. There has been no other report from India on this subject.

Adolescent↗
PubMed1989

Effects of pyrimidine-2-thiol on the ovarian histology of Epilachna vigintioctopunctata (Fabr.) (Coleoptera: Coccinellidae).

The telotrophic ovary of Epilachna vigintioctopunctata is composed of 32-40 ovarioles, each with an apical germarium and a basal vitellarium. The germarium encloses mononucleate and binucleate trophocytes, prefollicular tissue and oogonia, while the vitellarium contains 2-5 oocytes arranged in order of maturity. Definite nutritive cords are absent. When females are exposed to 75 mg 4,4,6-trimethyl-1h, 4H-pyrimidine-2-thiol by contact, the trophocytes and the follicular epithelial cells disintegrate to form dark-staining clumps and thus fail to supply nourishment to the developing oocytes, which consequently remain yolk-less and are ultimately reduced to shrunken masses.

Animals↗
PubMed1988

Aromatic hydroxylation of phenylalanine as an assay for hydroxyl radicals: application to activated human neutrophils and to the heme protein leghemoglobin.

Attack of hydroxyl radical (.OH), generated by a Fenton system at physiological pH, upon L-phenylalanine produces three isomeric tyrosines, o-tyrosine (2-hydroxyphenylalanine), m-tyrosine (3-hydroxyphenylalanine), and p-tyrosine (4-hydroxyphenylalanine). These may be separated by high-performance liquid chromatography and measured using an electrochemical detector. Since L-phenylalanine is relatively nontoxic, it is proposed that generation of these three tyrosines from phenylalanine can be used as an assay for .OH in biological systems. The use of the assay to measure .OH production by leghemoglobin (plus H2O2) and by activated human neutrophils is described. No .OH production by activated human neutrophils was observed unless a source of iron ions was added to the reaction mixture, which suggests that these cells do not release an iron "promoter" of .OH generation from superoxide and hydrogen peroxide.

Chromatography, High Pressure Liquid↗
PubMed1988

Correlation of histologic types of carcinoma of the uterine cervix and human papillomavirus and herpes simplex virus type 2 DNA sequences in the uterine cervical biopsies.

Forty patients with invasive cancer of cervix from New Delhi were examined for the presence of human papillomavirus (HPV) and herpes simplex virus (HSV) type 2 DNA sequences in a Southern hybridization assay. Data were analysed according to the histologic type of cancer. HPV DNA sequences were detected in 82.5% biopsies and HSV-2 DNA sequences were found in 10% biopsies. HPV-16 DNA sequences were found either alone or together with HPV-18 and/or HSV-2 Bgl II N fragment in 55% biopsies from keratinizing squamous cell carcinoma, whereas HPV-18 sequences were found in 35% biopsies. Similarly, 50% biopsies from patients with non keratinizing squamous cell carcinoma contained HPV-16 DNA and 38.9% biopsies had HPV-18 DNA. HSV-2 Bgl II N DNA sequences were present in 10% biopsies which were also positive for HPV-16 and/or HPV-18 DNA sequences. Two biopsies from adenocarcinoma of uterine cervix contained HPV-18 and HPV-16 DNA sequences. Therefore, no significant correlation seems to exist between HPV-types and histologic types or grades of differentiation of tumor.

Adenocarcinoma↗