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Biomedical subjects

I Brown

Publications and source records attributed to I Brown.

At least 127 records · Page 7Linked to original sources
PubMed1980

Vitamin D binding globulin levels and affinity in various clinical conditions.

The approximate association constants of the plasma vitamin D binding globulin (Gc-globulin) for 25-hydroxycholecalciferol (25(OH)D3) and the plasma 25(OH)D3 binding capacities were measured in samples from 123 patients with a variety of disorders. No gross differences in binding affinities were observed between different groups of patients and controls. Many patients, however, had moderately reduced, and several had grossly reduced, plasma binding capacities. The changes in Gc-globulin relative to some other proteins are also described in detail in three patients during the course of their illness. Gc-globulin concentration and hence plasma vitamin D binding capacity can undergo rapid and marked changes during illness.

Adolescent↗
PubMed1979

Factors affecting the hydrolysis of ceramide-3 by alpha-galactosidase A from human liver.

1. The effect of detergents on the catalytic properties of alpha-galactosidase from human liver was studied using p-nitrophenyl-alpha-galactoside and galactosyl-alpha(1 leads to 4)-galactosyl-beta(1 leads to 4)-glucosylceramide (ceramide-3) as substrates. 2. The hydrolysis of p-nitrophenyl-alpha-galactoside by alpha-galactosidase was inhibited by commercial preparations of sodium taurocholate and by taurocholate purified from these preparations by thin-layer chromatography. The extent of inhibition was dependent on the concentration of the detergent and on the amount of protein present. The impurities present in the preparation also inhibited the hydrolysis. 3. The inhibition of taurocholate preparations of p-nitrophenyl-alpha-galactoside hydrolysis was pH-dependent. 4. The inhibition by taurocholate of p-nitrophenyl-alpha-galactoside hydrolysis can be partly overcome by adding glycosphingolipids. 5. No significant hydrolysis of ceramide-3 occurs in the absence of detergent. Upon adding increasing concentrations of taurocholate, the rate of hydrolysis increases to a maximum value. At still higher taurocholate concentrations the activity decreases. 6. The concentrations of taurocholate giving a maximal rate of hydrolysis of ceramide-3 is dependent on the amount of protein present and independent of the ceramide-3 concentration. 7. When the pH dependence of the rate of hydrolysis of ceramide-3 was measured in the presence of a commercially available preparation of pure taurocholate or of crude taurocholate, curves with different shapes were obtained.

Ceramides↗
PubMed1978

Therapeutic consequences of antitumour drug interactions: methotrexate and 5-fluorouracil in the chemotherapy of C3H mice with transplanted mammary adenocarcinoma.

Methotrexate and 5-fluorouracil at fixed dosages of 1.5 mg/kg and 50 mg/kg, respectively, were employed in combination chemotherapy for transplanted mammary adenocarcinoma in C3H mice. Tumour regression analyses demonstrated the importance of drug sequence and scheduling. Significantly, a drug synergism and antagonism was exhibited under certain conditions. Results indicated a superior therapeutic efficacy when methotrexate was administered 6-12 h before 5-fluorouracil; the reverse proved antagonistic. However, at longer intervals a commutative additivity was apparent. Judicious scheduling of methotrexate and 5-fluorouracil would seem appropriate, as both drugs are widely employed in the current management of neoplasms, such as breast carcinoma.

Adenocarcinoma↗
PubMed1977

Organization and transcriptional activity of brain chromatin subunits.

Digestion of brain nuclei with micrococcal nuclease produces 11.2-S chromatin subunits which comprise up to 80% of the total nuclear DNA. Hybridization studies with excess subunit DNA demonstrate that subunits are distributed throughout the repeated and nonrepeated sequences of the genome. No class of nonrepeated DNA appears to be excluded from subunits. Transcribed DNA is present in chromatin subunits since in vitro labelled poly(A+)-mRNA hybridizes to excess subunit DNA with kinetics identical to that for total DNA.

Animals↗
PubMed1977

The comparative toxicity and therapeutic efficacy of adriamycin and the adriamycin-DNA complex in the chemotherapy of C3H mice with transplanted mammary adenocarcinoma.

Tissue analyses and tumour regression studies using the oncolytic antibiotic, adriamycin (14-hydroxydaunomycin), and its DNA complex at adriamycin dosages of 5 mg/kg and 10 mg/kg were made on C3H mice with transplanted mammary adenocarcinoma. Chemical analysis indicated a significantly lower (P < 0.05) uptake of adriamycin into cardiac tissue for the adriamycin-DNA complex. Tumour regression was comparable for both the complex and free adriamycin. Results suggest an advantageous role for the adriamycin DNA complex in the chemotherapy of metastatic breast carcinoma.

Adenocarcinoma↗
PubMed1976

Synthesis of the brain-specific S-100 protein in a cell-free system from wheat embryo programmed with poly(A)-containing RNA from rabbit brain.

Polyadenylated polysomal RNA was prepared from rabbit cerebral hemispheres using phenol extraction and chromatography on oligo(dT)-cellulose. This RNA directed the synthesis of the brain-specific S-100 protein in cell-free extracts from wheat embryo. S-100 protein was absent from the products of endogenous incorporation and from a reaction programmed with kidney mRNA. These results suggest that S-100 protein mRNA contains a poly(adenylic acid) sequence and rule out the necessity of a brain-specific factor for translation of -S100 protein mRNA.

Animals↗
PubMed1975

A study of the "capsular" shadow in disorders of the hip in children.

Displacement and blurring of the soft-tissue shadows about the hip has been described in several conditions, particularly in transient synovitis. A study was made between such displacements and the posture commonly adopted by an "irritable hip". Examination of radiographs of normal hips, and of those in cases of transient synovitis and Perthes' disease showed that the appearance of "capsular swelling" is related to the position of lateral rotation and abduction. This was confirmed by anatomical dissections of the lateral plane, which appears to be an intermuscular plane lying anterior to the hip, and an explantation is given for the blurring which may accompany its lateral displacement. "Capsular swelling" appears to be a radiological artefact.

Child↗