Search PubMed⌕ Search

Biomedical subjects

S Kaur

Publications and source records attributed to S Kaur.

At least 235 records · Page 13Linked to original sources

Characterization of structural xenobiotic modifications in proteins by high sensitivity tandem mass spectrometry. Human hemoglobin treated in vitro with styrene 7,8-oxide.

Alkylation of DNA by xenobiotic agents, or their electrophilic metabolites, is believed to be the major initiating process that may result ultimately in carcinogenesis. The study of hemoglobin alkylated in vivo by chemical carcinogens has previously been proposed as an indicator for DNA alkylation. Xenobiotically modified proteins, however, are not readily amenable to conventional methods for amino acid sequencing. Tandem mass spectrometry allows unambiguous structural elucidation of chemically modified proteins. Styrene is a widely used chemical in the plastics industry and its major metabolite, styrene 7,8-oxide, is both mutagenic and carcinogenic in rodents. Human hemoglobin was modified in vitro with styrene 7,8-oxide and digested with trypsin. Tryptic peptides from unmodified hemoglobin were isolated by high performance liquid chromatography, and their molecular weights were determined by liquid secondary ion mass spectrometry. This allowed confirmation of the known sequence of the protein and provided a reference for the identification of modified peptides. High performance tandem mass spectrometry of modified peptides allowed unambiguous assignment of specific residues modified. The externally accessible histidines were found to be the dominant sites for alkylation at high modification levels of the protein.

Alkylation↗

Pemphigus in pregnancy.

The clinical course and favorable fetal outcome in a primigravid woman with pemphigus vulgaris are reported.

Adult↗

Lead and cadmium in maternal blood, umbilical cord blood, amniotic fluid and placenta of cows and buffaloes after foetal death (abortion) and after normal parturition.

The cause of abortion in dairy animals is not yet exactly known. Concentrations of lead and cadmium in maternal blood, umbilical cord blood, amniotic fluid and placenta under foetal death (abortion) conditions and after normal parturition has demonstrated that these tissues in aborting cows and buffaloes accumulate much more lead and cadmium as compared to the normally delivering cows and buffaloes. It is believed that the toxic metals cause damage to the placenta and thus foetal death.

Abortion, Spontaneous↗

O6-substituted-2'-deoxyguanosine-3'-phosphate adducts detected by 32P post-labeling of styrene oxide treated DNA.

32P post-labeling of DNA reacted with styrene oxide resulted in the detection of six adducts. In order to determine which of these corresponded to modification at the O6 position of guanine, O6-substituted styrene oxide-deoxyguanosine-3'-monophosphate derivatives were synthesized. The two synthetic isomers were purified by HPLC and the structures were confirmed by mass spectrometry and 1H NMR. 32P post-labeling and co-chromatography with the DNA-styrene-7,8-oxide reaction products resulted in the assignment of adduct number 4 as O6-(2-hydroxy-2-phenylethyl)-2'--deoxyguanosine-3',5'-bisphosphate and adduct number 5 as O6-(2-hydroxy-1-phenylethyl)-2'-deoxyguanosine-3',5'-bisphosphate.

Chemical Phenomena↗

Reticulate acropigmentation of Kitamura.

Reticulate acropigmentation of Kitamura in a mother and her daughter is reported. Both demonstrated peri-orbital involvement in addition to involvement of acral areas, face and eyelids which has not been recorded before.

Adolescent↗

Effect of gossypol on the concentration of sodium and potassium in the rat epididymis.

The effects of administration of gossypol acetic acid (7.5 mg/kg daily for 4 weeks) on the concentration of Na+ and K+ in the rat epididymis was assessed. Epididymal fluid samples, collected by micropuncture, from the caput, corpus, proximal cauda and distal cauda epididymis from gossypol-treated and control animals were analysed for Na+ and K+ concentrations. Gossypol-treated males failed to impregnate healthy females, presumably because their sperm were immotile. In gossypol-treated rats, Na+ levels decreased significantly (P less than 0.01) in the caput, corpus, proximal and distal cauda epididymis. In contrast, the K+ concentration was increased significantly (P less than 0.05) only in the caput and corpus epididymis. This altered electrolyte milieu may be responsible, to some extent, for immotility and hence infertility.

Animals↗

Survey of cutaneous lesions in Indian newborns.

A total of 900 consecutive newborns delivered at the Nehru Hospital, Chandigarh, India, over a period of 7 months were examined for presence of skin lesions within 48 hours of birth. Commonly observed skin lesions were Epstein pearls (88.7%), mongolian spots (62.2%), milia (34.9%), sebaceous hyperplasia (31.8%), salmon patches (28.4%), and erythema toxicum neonatorum (20.6%). These figures are comparable with earlier reports. Impetigo neonatorum occurred in 11.3% of infants, and was frequent in our hot and humid climate from May to August. Traumatic skin lesions were most often present in babies who had forceps deliveries. Three hundred ten (34%) babies were available for follow-up up to six weeks. Additional skin lesions observed were omphalitis (16 babies), oral thrush (9) and postinflammatory hypomelanosis (8). Three infants had atopic dermatitis, two each had seborrheic dermatitis, diaper dermatitis, pityriasis versicolor, and nevus achromicus. One each had vitiligo, ichthyosis vulgaris, urticaria, and strawberry hemangioma. These observations highlight the importance of repeat examination for the appearance of skin lesions during the neonatal period.

Female↗

Rothmund-Thomson syndrome in two siblings.

Rothmund-Thomson syndrome, a rare autosomal recessive disorder, is characterized by photosensitivity; specific skin changes including poikiloderma, atrophy, and telangiectases; juvenile cataracts; short stature; and bone defects. We describe two siblings with this syndrome.

Bone Diseases, Developmental↗

Fetal hydantoin syndrome: a case report.

An infant with features of fetal hydantoin syndrome, born to an epileptic mother, was followed from birth to 20 months of age. Physical findings included gum hypertrophy, digitalization of the thumbs, hypoplasia of the distal phalanges and nails, epicanthal folds, pseudohypertelorism, epidermoid cyst, and geographic tongue. Available literature about the disorder is reviewed.

Abnormalities, Drug-Induced↗