Biomedical subjects
F O Adebonojo
Publications and source records attributed to F O Adebonojo.
Plasma-vitamin E and low plasma lipoprotein levels in sickle cell anemia patients.
Increasing evidence suggests that in vivo lipid peroxidation may be an important factor in sickle cell anemia (HbSS). Vitamin E is the major lipid-soluble antioxidant in plasma, and this vitamin, as well as cholesterol, is transported in plasma almost exclusively by lipoproteins. The purpose of this investigation was to determine if vitamin E and plasma lipoprotein-cholesterol levels in sickle cell anemia (SCA) patients are interrelated. We found that low plasma-vitamin E levels in SCA patients were accompanied by low levels of plasma-cholesterol. The mean plasma-vitamin E/plasma-cholesterol ratio was similar in 12 SCA patients (6.1 +/- 0.7 micrograms vitamin E per mg plasma-cholesterol) and 21 controls (6.5 +/- 0.7 micrograms/mg). Our results suggest that the low levels of plasma-vitamin E in SCA patients may be related to decreased levels of lipoprotein carriers. The low plasma-cholesterol levels in SCA patients (139.1 +/- 9.9 mg/dL) were due to low levels of both high density lipoprotein-cholesterol (HDL-cholesterol of 35.0 +/- 1.0 mg/dL) and low density lipoprotein-cholesterol (LDL-cholesterol of 97.8 +/- 9.2 mg/dL). The "atherogenic index," defined as LDL-cholesterol/HDL-cholesterol, was similar in the SCA patients (2.9 +/- 0.2) and the controls (3.0 +/- 0.4).
A novel spectrophotometric assay for lipase activity utilizing cis-parinaric acid.
A new spectrophotometric assay for determining the activity of acylglycerol hydrolases (lipases, E.C. 3.1.1.3) was developed and optimized for yeast lipase (Candida cylindracea). Studies with porcine pancreatic lipase were also conducted and the influence of various detergents and divalent cations on the assay was evaluated. The assay uses cis-parinaric acid (PnA), a naturally occurring fatty acid that has unique spectroscopic properties, and takes advantage of the reversible binding of fatty acids to bovine serum albumin (BSA). Free PnA has an ultraviolet absorption peak at 321.2 nm. When PnA is bound to BSA, however, the peak shifts to 324.2 nm. The assay mixture contains 6 microM PnA, 1 microM BSA, 75 microM triolein, and 0.3 mM taurocholate in a 50 mM tris-HCl buffer with 1 microM EDTA. The release of oleic acid from triolein is monitored over time by measuring the ratio of optical densities (OD) at 319.0 and 329.0 nm. Initially, there is maximum binding of PnA to BSA, and the OD ratio is approximately 1.0. Upon addition of lipase, PnA is displaced from the BSA by oleic acid released from triolein, and the OD ratio increases to a maximum of about 1.8. However, when calcium is present in the reaction mixture an insoluble calcium-PnA complex forms, resulting in a progressive decrease in OD at both 319.0 and 329.0 nm. The kinetic assay described here is simple, rapid, sensitive, reproducible, inexpensive, and it can be adapted to measure the activity of a variety of calcium-independent lipases. Under similar assay conditions, activities for Candida cylindracea lipase obtained with this assay are similar to those obtained with 14C-labelled triolein.
Nutrition in the management of renal failure in black children.
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Catechol effect on the lysosomal enzymes in the adipose tissues of obese and obese-diabetic monkeys.
The activities of three lysosomal hydrolases were assayed in the basal and isoproterenol-stimulated states in the adipose tissues of lean, obese and obese-diabetic monkeys. The basal activity of acid lipase appeared higher in the obese tissues with or without diabetes than in the lean tissue. Isoproterenol stimulation did not affect these activities. The basal activity of beta-galactosidase (beta-Gal) was similar in all tissues and unaffected by isoproterenol stimulation. Although basal activity of hexosaminidase (Hex) was comparable in all tissues, activity increased significantly in the stimulated diabetic-obese tissue but not in the stimulated tissues from lean animals or animals with simple obesity.
Lysosomal acid hydrolases of normal adipose tissues of man, monkey and rat.
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Acid and neutral lipases of cultured adipocytes of infants and children.
In order to determine whether the mobilization of intracellular triglycerides observed in cultured human adipocytes is associated with changes in the activities of acid and neutral lipases, the activities of both enzymes were measured weekly on cultured adipocytes for several months. The activity of acid lipase was initially very low, but rose to levels 40 times the original activity within 3 months. The activity of neutral lipase decreased rapidly within the first 2-4 weeks and remained at approximately 25% of original levels thereafter.
Neutral and acid lipase of mouse 3T3 fibroblasts with increased adipose conversion.
In the resting state, 3T3-L1 fibroblasts become adipose converted and increase their fatty acid and triglyceride synthetase. We have found that they contain four times the neutral lipase activity and 1.5 times the acid lipase activity of logarithmically dividing cells. The activities of lysosomal acid beta-galactosidase and N-acetyl-beta-D-glucosaminidase were the same in the adipose converted and logarithmically dividing cells. The data suggest a possible relation between the increased neutral lipase activity in 3T3-L1 cells and their adipose conversion and demonstrates that the adipose converted 3T3-L1 fibroblasts, unlike true adipose cells, contain high levels of lysosomal acid hydrolases.
Triglyceride mobilization in cultured adipocytes of human infants.
Cultured adipocytes of human infants, in the absence of known lipolytic agents, are capable of mobilizing their own stored triglycerides as showed by a decrease in the content of stored triglycerides with time. The medium used is synthetic, fortified with 20% fetal calf serum and contains adequate amount of glucose. It is suggested that lipolysis occurs because the metabolic balance favors lipolysis in the absence of adequate amount of free fatty acids in the medium. Conversely lipogenesis is favored in the presence of such fatty acids.
Congenital dislocation of the hip--diagnostic screening and treatment. A comparative study of two populations of infants and children.
To understand why congenital dislocated hip (CDH) was diagnosed late (mean age: nine months) in children admitted to the Children's Hospital of Philadelphia (CHOP), 714 consecutive CHOP admissions, aged zero to two years, and 947 consecutive newborns delivered at the Hospital, University of Pennsylvania (HUP) were examined for CDH. The expected frequency of CDH was found at HUP. At CHOP, the children had a higher incidence of CDH, many with associated congenital anomalies, their hips were more difficult to examine, the hospital records contained few references to hip examinations. Had these children's hips been formally examined at birth, the delay in diagnosis might have been eliminated and treatment might have been easier and more successful.
Tuberculosis among urban black children: failure of comprehensive health care services to influence incidence rates.
Over a three-year period, in 2,700 children aged two weeks to 19 years in a South Philadelphia ghetto, the new case rate for tuberculosis was 177 per 100,000 per year and the rate for new conversions was 673 per 100,000 per year. Children with recent conversions or with active disease were, on the average, slightly older and had older mothers and more adults and siblings at home than the rest of the child population. Parents or other residents of the home were the contacts. Children 10 to 14 years of age were the most frequently affected. Children who had been receiving continuous comprehensive health care for more than three years had the same attack rates as new children in the program.
Enzymatic adaptations by cultured adipocytes of human infants and children: effect of obese serum on the activities of lactate-, malate-, and glucose-6-phosphate dehydrogenases.
To determine whether there are any biochemical characteristics which distinguish human adipose cells from human skin fibroblasts, assays of lactate dehydrogenase with pyruvate as substrate (LDH-P), malate dehydrogenase (MDH), and glucose-6-phosphate dehydrogenase (G6PDH) were done on both cell types after they had been successfully adapted to artificial medium in tissue culture and also while they were growing temporarily in serum from an obese individual. After undergoing transformation to a fibroblast-like appearance, the adipose cells (adipofibroblasts) contained significantly more of each enzyme than did the initial adipose cell isolates. The level of activities of LDH-P and G6PDH increased to the same levels as in skin fibroblasts (Table 2); however, MDH activities rose to much higher levels than those found in skin fibroblasts (Table 2). In obese serum, activities of LDH-P did not significantly change but the activities of MDH and G6PDH dropped sharply in adipofibroblasts (P less than 0.005, Table 2 and Fig. 5), whereas in cultures of skin fibroblasts, only the activities of G6PDH dropped significantly (P less than 0.025 Table 2), the other enzyme activities being unchanged. It is concluded that, on the basis of the biochemical behaviors of these two cell lines in culture, adipose cells are biochemically different from skin fibroblasts and are not to be regarded as just fibroblasts with lipid-storing ability.
Subclinical lead burden: relation to hemoglobin and hematocrit values.
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Studies on human adipose cells in culture: relation of cell size and multiplication to donor age.
In an effort to test the adipose hyperplasia theory of obesity in humans, adipose cells, derived from anterior abdominal walls of human infants and children, were grown in synthetic medium (McCoy's 5A Medium) supplemented with 20% fetal calf serum. Adipose cells which became delipidinized in culture were found to be capable of division and the rate and number of cell divisions was age dependent. Cells of infants under 1 yr of age and cells derived from early adolescent children divided to varying degrees in culture. Adipose cells from children aged 1-10 yr showed no cell division. Cell division was never observed in a lipid-laden adipocyte. Measurements of cell diameter showed that after the first year of life, cell size increased progressively with age. During the first year adipose cell size appeared to reflect the rapid hyperplasia of the first 3 mo, reaching smallest size at 3-12 mo but increasing thereafter.
Vitamin nutriture in black, urban, day care children.
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Reducing the lead burden of urban ghetto children.
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Primary exogenous obesity. A conceptual classification.
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Hematologic status of urban black children in Philadelphia.
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