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Biomedical subjects

M S Jacobson

Publications and source records attributed to M S Jacobson.

At least 55 records · Page 3Linked to original sources
PubMed1990

Human blood cells at microgravity: the NASA Initial Blood Storage Experiment.

The Initial Blood Storage Experiment (IBSE) probed the behavior of human red cells, white cells, and platelets during exposure to microgravity for 6 days and 2 hours on a National Aeronautics and Space Administration (NASA) shuttle mission, named STS 61-C, which was launched on January 12, 1986. IBSE involved carefully controlled comparisons between two identical sets of blood cells, one exposed to microgravity and the other held on the ground. Specially designed and fabricated, electrically powered environmental chambers provided appropriate environmental temperatures and air flow to support cell metabolism throughout the experiment. To circumvent the need for constant agitation of platelets during storage, a new thin-layer compression method for platelet preservation was developed. Blood cell samples were allocated to the two arms of the experiment, microgravity and earth gravity, by blind assignment. Moreover, to ensure unbiased assessment of the experiment's findings, postexperiment samples for measurement were identified by code. To optimize the chances of detecting possible gravitational effects, a wide array of measurements of cellular function, morphology, metabolism, and immunology were made. Analysis of variance was used in analyzing the data. The most striking finding was that platelets displayed markedly superior structural and functional integrity at microgravity. Granulocytes held on the ground were preserved slightly better than those that orbited in the shuttle, whereas red cells displayed few effects that were attributable to the gravitational variable. Polyvinylchloride-di-(2-ethylhexyl)phthalate (PVC-DEHP) was the plastic of choice for storage of red cells, while PVC-trioctyltrimellitate (TOTM) was superior to PVC-DEHP and polyolefin (PO) for platelets.

Aerospace Medicine↗
PubMed1990

Nonradioactive chromium technique for red cell labeling.

Following transfusion, red cells labeled with nonradioactive chromium (52Cr) can be detected in the circulation using atomic absorption spectrophotometry. Both in rhesus monkeys and in human subjects, the survival of red cells labeled with 52Cr was found to be insignificantly different from that of cells labeled with 51Cr. Nonradioactive chromium can be used to label a second population of red cells, when 51Cr is used for the first population, or can be used on its own when the use of radioactivity is contraindicated.

Animals↗
PubMed1989

Dyslipoproteinemia in murine systemic lupus erythematosus.

Dyslipoproteinemia, a feature of systemic lupus erythematosus may contribute to premature atherosclerosis. In order to develop an experimental model for this dyslipoproteinemia we measured plasma concentrations of lipoproteins in juvenile NZB/W (lupus) and NZB/B (control) mice. Additionally to evaluate the effects of a diet rich in n - 3 fatty acids we measured lipoprotein concentrations in mice on normal or menhaden oil-enriched diets. The lupus mice had elevated triglycerides compared to the controls, similar to that seen in human SLE patients (161 +/- 31 vs 113 +/- 13 mg/dl, P less than 0.003). In contrast, the menhaden oil diet fed NZB/W mice had triglycerides similar to the NZB/B control fed group. In the NZB/W murine SLE model, dyslipoproteinemia is an early sign of disease as has been shown in man, therefore this model will be useful in elucidating the mechanism of dyslipoproteinemia in SLE.

Animals↗
PubMed1989

Storage of platelets in earth orbit. Effect of gravity and the formulation of plastic storage containers on platelet IgG and C3.

We investigated the effects of gravitational force and three different plastic formulations of the storage bags on the quality of stored platelets by measuring the changes in platelet-associated immunoglobulin G (IgG) and two antigenic markers of the third component of human complement (C3), C3d and C3c. Pooled platelets were stored in parallel at microgravity (MG) and on the ground (1 g) using three different plastic polymers: (1) polyvinylchloride (PVC) plasticized with di-2-ethylhexyl phthalate (DEHP); (2) PVC plasticized with trioctyl trimellitate (TOTM), and (3) unplasticized polyolefin (PO). The IgG and C3 were quantified by an automated antiglobulin consumption test in freeze/thaw disrupted platelets (total IgG or C3). The baseline values for platelet associated IgG and C3, measured after 2.5 days of storage at 1 g just prior to the launch, fell within the normal range. Following an additional 6.5 day storage, platelets stored at MG had accumulated significantly less C3d than those stored at 1 g, suggesting that MG storage was beneficial. Specific plastic formulations also exerted a significant effect on the accumulation of these immunoproteins, the effect being particularly pronounced at MG. The smallest increases of IgG and C3 were seen in platelets stored in TOTM and the largest in those stored in DEHP. It is possible that further studies at MG would permit a clear characterization of the effects of other independent storage variables.

Benzoates↗
PubMed1989

Prevention of atherosclerosis in children.

Atherosclerosis, the most common cause of death in the U.S., is a process that begins in childhood. Conditions and behaviors that have been associated with increased risk of atherosclerosis can be modified, with resulting decreases in risk. All children should be screened for risk factors, which include hypercholesterolemia, hypertension, smoking, obesity, and lack of exercise. Treatment for hypercholesterolemia includes reassurance, modification of the diet and, in rare instances, medication.

Arteriosclerosis↗
PubMed1988

Dyslipoproteinemia in pediatric systemic lupus erythematosus.

Patients with systemic lupus erythematosus are at increased risk for premature atherosclerosis. We examined one possible etiologic factor, dyslipoproteinemia, both before and after corticosteroid therapy. We identified 2 distinct patterns of dyslipoproteinemia. One is attributable to active disease; the other is attributable, in part, to corticosteroid therapy. The dyslipoproteinemia of active disease consists of depressed high density lipoprotein cholesterol and apoprotein A-I with elevated very low density lipoprotein cholesterol and triglyceride, while the dyslipoproteinemia after corticosteroid therapy consists of increased total cholesterol, very low density lipoprotein cholesterol, and triglyceride. The possible pathophysiologic mechanisms responsible for these patterns, as well as the possible roles in premature atherosclerosis seen in systemic lupus erythematosus patients, are discussed.

Adolescent↗
PubMed1988

A new approach to neocyte transfusion: preliminary report.

A method has been developed using phthalate oils to quality control units of young red cells (neocytes). Neocytes prepared by the NEOCEL system have a mean young red cell enrichment of 90% with only 3.4% less than 80%. Neocytes prepared in a blood cell processor have an average enrichment of 81% with 27% less than 75%. Based on a 12 month period, the patients as a group have received an average of 14% fewer transfusions and an 18% decrease in red cells per kg/yr as compared to frozen red cells.

Blood Component Removal↗
PubMed1988

Anthropometric predictors of low birth weight outcome in teenage pregnancy.

The highest relative risks of low birth weight are found among births to teenage mothers. An analysis of anthropometrics (weight, mid-arm circumference, and triceps skinfold) among black teenagers attending an adolescent prenatal program was studied. The sample consisted of 100 girls under 17 years. Data were collected from 19 to 35 weeks gestation. Adolescent mothers who delivered low birth weight (LBW) infants demonstrated different patterns of anthropometric changes than teen mothers who delivered normal birth weight (NBW) infants. Mean mid-arm circumference increases in the LBW group (0.05 mm/wk) were significantly less than mean increases in the NBW group (0.80 mm/wk) (p less than 0.05). Arm fat area estimates of the LBW mothers demonstrated weekly depletion (-24.9 mm2/wk), which was significantly less than those of the NBW group, who accumulated fat (+15.3 mm2/wk) (p less than .05). Changes in maternal nutritional status may in part mediate the birthweight outcome in adolescent pregnancy. Anthropometrics may be useful in predicting those teens at highest risk of bearing LBW infants.

Adolescent↗
PubMed1988

The pediatrician's role in atherosclerosis prevention.

Prevention of atherosclerosis, a major cause of illness and death in our society, is a pediatric responsibility in 1988 and beyond. Significant cardiovascular risk factors are identifiable and alterable in children and adolescents, and are associated with arterial lesions. Cost-effective atherosclerosis prevention can be achieved by identification and treatment of high-risk children and adolescents. The pediatrician should record the family history of all patients at 2 years of age, with periodic updates. The serum cholesterol concentration can then be measured in the office if there is a commitment to quality control; otherwise, a monitored commercial laboratory must be used. It is not unreasonable to measure serum cholesterol concentrations once in all school-age patients. The majority of high-risk patients will respond to nutritional intervention and will not require pharmacotherapy. Until the efficacy and safety of the therapeutic diet are proved beyond doubt, its use should be limited to high-risk patients under pediatric supervision. Studies documenting the growth and development of children receiving dietary therapy must be a major priority of pediatric nutrition. Until that is accomplished, although some pediatricians may prefer to wait, most will use the extensive scientific evidence at hand and their clinical judgment to identify and treat their high-risk patients.

Adolescent↗
PubMed1987

Cholesterol oxides in Indian ghee: possible cause of unexplained high risk of atherosclerosis in Indian immigrant populations.

Two populations of immigrants to London and to the West Indies from the Indian subcontinent have higher than expected morbidity and mortality from atherosclerosis but do not show the commonly accepted major risk factors. This study investigated the hypothesis that ghee, a clarified butter product prized in Indian cooking, contains cholesterol oxides and could therefore be an important source of dietary exposure to cholesterol oxides and an explanation for the high atherosclerosis risk. Substantial amounts of cholesterol oxides were found in ghee (12.3% of sterols), but not in fresh butter, by thin-layer and high-performance-liquid chromatography. Dietary exposure to cholesterol oxides from ghee may offer a logical explanation for the high frequency of atherosclerotic complications in these Indian populations.

Arteriosclerosis↗
PubMed1987

Reduction in pulmonary function and increased frequency of cough associated with passive smoking in teenage athletes.

Previous studies have suggested that passive smoking (involuntary inhalation of tobacco smoke by nonsmokers) reduces small airways function. We evaluated the exposure to passive smoking and its effects on pulmonary function and symptoms in a group of 12- to 17-year-old high school athletes (N = 209; 119 boys and 90 girls) at their annual presport participation physical examinations. A structured interview was used to assess pulmonary symptoms, personal smoking habits, and passive cigarette smoke exposure. All athletes performed forced expiratory maneuvers on a portable spirometer. We measured forced vital capacity, forced expiratory volume in 1 second, and forced expiratory flow 25% to 75% (FEF25-75). The best of three FEF25-75 measured was used. Less than 70% of predicted FEF25-75 was considered abnormal. Of the 209 athletes, 7.7% were active smokers and were excluded. Of the remaining 193 athletes, 68.4% were currently exposed to passive smoking. We found a fourfold increase in incidence of low FEF25-75 and/or cough in athletes exposed to passive smoking compared with athletes not exposed: 18 of 132 exposed athletes (13.6%) had low FEF25-75 and/or cough compared with two of 61 unexposed athletes (3.3%) who had low FEF25-75 and cough (P = .02). Boys were more frequently exposed to passive smoking than girls (74% of boys [80/108] v 61% of girls [52/85] ), but the effects were more pronounced in girls. These data show a relationship between exposure to passive smoking and early pulmonary dysfunction in young athletes. The frequent exposure to passive smoke and the high prevalence of dysfunction in this population, generally considered to be healthy, is of particular concern.

Adolescent↗
PubMed1986

Follow-up of adolescent trauma victims: a new model of care.

A comprehensive model of service delivery for the rehabilitative care of adolescents with closed head injuries is presented. Our data show that the Glasgow Coma Scale score on hospital admission correlates with the length of time required for follow-up. Adolescents with mild closed head injuries require more follow-up than adults with comparable injuries because of adolescent developmental stages that complicate the recovery process. Anticipatory guidance has helped the patient and family cope with stresses. Finally, we have identified a typical pattern of difficulties during the recovery process including: impaired judgment, reduced attention span, irritability, short-term memory loss, and ongoing memory deficits.

Adaptation, Psychological↗
PubMed1985

Atherogenesis in white carneau pigeons. Effects of low-level cholestane-triol feeding.

Cholesterol auto-oxides have been shown to be angiotoxic in vivo and in vitro. Whether this toxicity is itself an atherogenic risk factor has not been established. In this study White Carneau pigeons were gavage-fed either 0.05% pure cholesterol or 0.05% pure cholesterol with trace levels of cholestane-triol (cholestane-3 beta,5 alpha,6 beta-triol) for 3 months. These are amounts similar to estimated U.S. dietary intake levels. Aortic lipids, aortic calcium and coronary artery histopathology were assessed. Aortic total cholesterol, cholesterol ester, and cholesterol ester/cholesterol ratio were: 1.87 vs 1.70 mg/g, 1.23 vs 1.01 mg/g, and 25 vs 26% for the cholesterol vs cholesterol + triol groups, respectively. These values are similar to published values at this duration and level of cholesterol feeding and are not statistically significantly different from each other. Aortic accumulation of calcium in the cholesterol + triol group was 1.16 +/- 0.35 mg/g, whereas in the cholesterol-fed group it was 0.82 +/- 0.27 mg/g, an increase of 42% (P greater than 0.02). Coronary artery atherosclerosis, as measured by percent mean lumenal stenosis, was 5.23% +/- 5.4, in the cholesterol + triol group as compared to 2.80% +/- 1.4 in the cholesterol group, an increase of 87% (P less than 0.01). These results suggest that dietary exposure to low levels of cholestane-triol, is atherogenic to a greater degree than exposure to pure cholesterol alone.

Animals↗
PubMed1985

Cardiac sarcoplasmic reticulum. Effects of an atherogenic diet during the neonatal and juvenile period.

The effect on the cardiac sarcoplasmic reticulum of an atherogenic (1% cholesterol) diet fed during the neonatal vs the juvenile period of life was studied in Yorkshire swine. Male piglets were randomly assigned at birth to 1 of 4 groups: group I (control), group II (lactation feeding), group III (juvenile period feeding) and group IV (lactation and juvenile feeding). All animals were killed at 55 weeks of age and cardiac sarcoplasmic reticulum (SR) isolated for assay of calcium uptake, Ca2+-Mg2+ ATPase activity, and lipid analysis by thin-layer chromatography and gas chromatography. The amount of cholesterol/mg SR protein and the cholesterol/phospholipid ratio were higher in the animals fed during lactation (groups II and IV) and lower in those fed only during the juvenile period (group III). Phospholipid fatty acid patterns as measured by gas chromatography were unaltered in any group. Calcium uptake was markedly diminished in all experimental conditions: group II 47%, group III 65% and group IV 96%. Compared to the observed changes in calcium transport, the ATP hydrolytic activity was relatively less affected. Only in group IV a significant decrease (41%) was seen. Groups II and III show no change in ATP hydrolytic activity. The decrease in calcium uptake and altered cholesterol/phospholipid ratio without effect on ATP hydrolytic activity is consistent with an uncoupling of calcium transport related to the atherogenic diet in early life.

Age Factors↗
PubMed1985

Single-dose versus conventional therapy of urinary tract infections in female adolescents.

A randomized, prospective study was done to assess the efficacy of single-dose nu conventional treatment of acute urinary tract infection (UTI) in female adolescents. Thirty-one 12- to 18-year-old female adolescents with symptoms of an acute UTI and a urine culture with greater than 10(5) organisms were treated with amoxicillin, either as a 3.0-g single dose or 250-mg three times daily for ten days. Urine cultures obtained three days after completing therapy in each group, showed bacteriologic cure rate of 69% (11/16) with single-dose treatment compared with a cure rate of 87% (13/15) in the conventional treatment group (P = .23). When patients with resistant organisms were excluded, the cure rate was 85% in both groups. Complete symptom resolution in less than two days after commencing treatment occurred in 36% of single-dose group nu none of the patients in the conventional-dose group. The finding has not been previously reported in single-dose trials. Candida vaginitis occurred in 20% of the conventional-dose group nu none of the single-dose group. All patients in the single-dose group kept their first scheduled follow-up appointment, whereas 40% in the conventional group required reminders and rescheduling. Perfect compliance with the medication regimen was reported by 27% of the patients taking ten days of medicine. Although single-dose cure rates may not be superior to conventional-dose rates, the advantages of single-dose treatment include increased compliance with medication and follow-up, decreased side effects, and more rapid resolution of symptoms.

Adolescent↗
PubMed1984

Kwashiorkor in Baltimore.

Advanced cases of malnutrition are rare in the United States. Since it is rarely suspected, a correct diagnosis of malnutrition, even in extreme form, may easily be missed. We present a recent case of the kwashiorkor form of the syndrome of protein-energy malnutrition to emphasize its diagnostic features and to enhance early recognition and initiation of proper therapy. The misunderstanding of a physician's recommendations by a teen-aged mother may have initiated this illness.

Adolescent↗