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Biomedical subjects

C Smith

Publications and source records attributed to C Smith.

At least 1,009 records · Page 56Linked to original sources

Nutrient intake: relationships with lipids and lipoproteins in 6--19-year-old children--the Princeton School District study.

Relationships between nutrient intakes and plasma lipids and lipoproteins were studied in 949 randomly selected children, ages 6--19, in the biracial, suburban, Princeton School District. While nutrient intake increased with age in males, such age-associated increases in nutrient ingestion were much less consistent or were not significant for females. Primarily in the 6--9 and 10--12 yr age groups, white children ingested more total calories, more saturated fat, and a lower ratio of polyunsaturated to saturated (P/S) fat, more total carbohydrates, sucrose, starch, and other carbohydrates, and more protein than black children. After adjusting for age, race, sex, weight, and height, several nutrient-lipid and lipoprotein partial correlation coefficients were significant, but of relatively low magnitude. There were weak but significant inverse correlations between dietary P/S ratios and dietary carbohydrates with both total (r = -.07, -0.7) and low-density lipoprotein cholesterol (C-LDL), (r = -.07, -.08). Plasma high-density lipoprotein cholesterol (C-HDL) was inversely and significantly correlated with dietary sucrose (r = -.07); plasma triglyceride correlated positively with dietary sucrose (r = .08). Potential relationships between nutrients and lipids-lipoproteins were also examined in children at the extremes of, and in the middle of, lipid-lipoprotein distributions. After covariance adjustment for age, sex, race, and Quetelet index, children having the highest levels of C-HDL had the lowest intake of dietary carbohydrate and total calories. After further covariance adjustment for total calories, children at the highest end of the plasma cholesterol distribution had a greater intake of cholesterol and total protein than did children in the lowest end of the distribution. Nutrient intake may play a small but significant role relative to lipids and lipoproteins in children, and as such, may have importance relative to pediatric precursors of atherosclerosis.

Adolescent↗

Reversal of paradoxical sleep deprivation by amygdaloid stimulation during learning.

Rats were subjected to a partial, selective paradoxical sleep (PS) deprivation. Two groups were trained in a shuttle avoidance task, one receiving posttraining amygdaloid stimulations (AS). A third group received AS, but was not trained. Levels of PS in the AS trained group were higher than in the AS non-trained controls, while the reverse was true for the slow wave sleep (SWS) measure. Both AS groups had levels of PS and SWS superior to the non-AS trained rats. In a second experiment, a group of normally rested AS animals was trained in the same task with a non-AS control group. These groups did not differ in terms of learning performance. Results were believed to support the hypothesis of a close relationship between sleep and learning.

Amygdala↗

Creatine kinase isoenzyme patterns in normal smooth muscle and smooth muscle neoplasms.

The CK isoenzyme composition of leiomyoma tissue is predominantly CK-BB and similar to adjacent myometrium tissue, while the leiomyosarcoma revealed a lesser quantity of CK-BB, but a greater quantity of CK-MM. The reasons for the discrepancy between the two types of neoplasms is not clear, but may reflect the changes which occur when smooth muscle becomes malignant.

Ankle↗

Isolation of factors in linseed oil meal protective against chronic selenosis in rats.

Two new cyanogenic glycosides, linustatin and neolinustatin, were isolated from linseed oil meal. Each of the compounds was fed to rats in a corn-based diet at levels of 0.1 and 0.2%. At the 0.2% level, both substances gave significant protection against growth depression caused by 9 ppm selenium as sodium selenite. Both compounds also promoted a significant increase in liver and kidney weight over the selenium control animals. Linustatin and neolinustatin are closely related in structure to linamarin and lotaustralin and were found to be present in linseed oil meal at levels of 0.17 and 0.19%, respectively. Linamarin fed at the level of 0.2% also gave significant protection against growth depression and liver damage. A related cyanogenic glycoside, amygdalin, appeared to give a small but nonsignificant protective response. The isolation of the two new glycosides provides a probable explanation for the protective activity of linseed oil meal against selenium toxicity.

Amygdalin↗

Measurement of free glucose turnover in brain.

A method has been developed for the measurement of the turnover rate constant or the half-life of the free glucose content of brain. It is based on an equation derived by the mathematical analysis of a kinetic model of the equilibration of the specific activity of the free glucose in brain with that of the plasma during an infusion of radioactive glucose. The method requires the measurement of the time course of the specific activity of glucose in the arterial plasma during an intravenous infusion of radioactive glucose for a period of 1 to 4 min and the specific activity of the free glucose in brain at the termination of the infusion. The turnover rate constant, or the half-life, is then calculated from these data by means of the operational equation of the method. The technique has been applied to conscious and anesthetized rats. In conscious rats the half-life of the free glucose content of brain was found to be 1.6 +/- 0.5 min (mean +/- S.D.) when the animals were killed by decapitation and 1.2 +/- 0.2 min (mean +/- S.D.) when they were killed by microwave irradiation; this difference is not statistically significant. In anesthetized rats, the half-life was found to be 2.6 +/- 0.8 min (mean +/- S.D.) in those killed by decapitation and 1.8 +/- 0.3 min (mean +/- S.D.) in those killed by microwave irradiation; this difference is statistically significant. The half-life of the glucose content of brain was found to be significantly prolonged during anesthesia and to be significantly and positively correlated with the plasma glucose concentration (r = 0.78; p < 0.001).

Animals↗

Effect of lecithin on disability and plasma free-choline levels in Friedreich's ataxia.

Four patients with Friedreich's ataxia took part in an open trial, in which they consumed 50-100g/day lecithin granules (containing approximately 22% phosphatidycholine) for 16 weeks, but no improvement resulted. Several unwanted effects including diarrhoea, nausea, depression, "hot flushes" and weakness were experienced. Resting levels of free-choline in plasma were within the range found in 19 normal subjects. Sixteen other patients with Friedreich's ataxia also had normal free-choline levels. Treatment with lecithin significantly increased plasma free-choline levels, but there was a trend for these to fall towards baseline levels, despite continued ingestion of lecithin.

Adolescent↗

Tympanoplasty.

Explore the source record for details and available documents.

Cholesteatoma↗

Psychiatric audits. The Ontario scene.

Results of a survey conducted early in 1978, about the state of psychiatric audits in Ontario, are presented and discussed. Of the facilities that responded 66% reported the existence of an audit system for psychiatric care. The picture that evolves from the survey shows that audits are comprehensive in only 52% of Ontario facilities, more so in the provincial psychiatric hospitals than in psychiatric units in general hospitals. The audits are multidisciplinary in 64% of all facilities. While only 50% of facilities involved in audits felt that audits have a positive impact on improvement of psychiatric care, 71% were positive that audits have contributed to continuing staff education. The authors report their experience in introducing a criteria audit system. Factors influencing the selection, as well as advantages and criticisms of this model are discussed.

Cost-Benefit Analysis↗

The use of physiological traits in genetic selection for litter size in sheep.

The objective was to quantify and compare the genetic responses by direct selection on litter size, by indirect selection through a physiological trait and by combined selection, combining litter size and the physiological trait in a selection index. Three kinds of physiological trait were considered, male sex-limited (e.g. testes size), female sex-limited (ovulation rate) and traits measurable in both sexes (gonadotrophin levels). The results are presented graphically and cover a wide range of possible situations and show the size of the responses for different parameters of the physiological trait. There is usually scope for improvement in the rate of response with combined selection, and also in special cases (high heritability and genetic correlation) with indirect selection. The increases in predicted response may range from zero to two or three times the direct response, depending on the genetic parameters. However, the need for reliable estimates of the genetic parameters is stressed, because the predicted responses might otherwise be overestimated and the selection effort misplaced.

Animals↗

Spotted fever group rickettsiae in Dermacentor variabilis from Cape Cod, Massachusetts.

Spotted fever group (SFG) rickettsiae were identified by indirect immunofluorescent antibody tests in 1.1% of 6,956 specimens of Dermacentor variabilis collected on Cape Cod, Massachusetts. Forty-one of 45 rickettsial isolates were serotyped as Rickettsia montana, one as Rickettsia rickettsii, and three were unidentified. Studies of canines and humans with clinical evidence of spotted fever, and of healthy dogs with antibody to SFG rickettsiae, indicated that exposure of the canine population to R. montana was common but that R. montana was not involved in the etiology of spotted fever.

Animals↗

Drosophila nuclei replicate in Xenopus eggs.

Nuclei isolated from a permanent cell line derived from Drosophila melanogaster embryos have been injected, along with a radioactive DNA precursor [3H]TTP, into Xenopus laevis eggs. In culture, less than 7% of the cells were in S phase. After a 90 min incubation, following injection into eggs, 99% of the nuclei were shown by autoradiography to have synthesized DNA. In a similar experiment, a density label BrdUTP was injected into eggs along with the nuclei. Subsequent analysis on caesium chloride gradients showed that this DNA synthesis was semi-conservative replication. Therefore we conclude that signals present in Xenopus egg cytoplasm can initiate and sustain true semi-conservative DNA replication in nuclei from an invertebrate organism.

Animals↗

Efficacy of immunoserodiagnostic procedures in the recognition of canine immunologic diseases.

Six immunologic tests were conducted on a large population of dogs with a variety of diseases. The test results were analyzed retrospectively and correlated to the clinical and final pathologic diagnoses. The results indicated that rheumatoid factor and the direct antiglobulin (Coombs) test were both sensitive and specific for the diagnoses of canine rheumatoid arthritis and autoimmune hemolytic anemia. The antinuclear antibody test was useful in supporting the diagnosis of systemic lupus erythematosus (SLE) only when both antibody titer and the staining pattern were taken into consideration. The lupus erythematosus cell test was specific but not sensitive when used to confirm a diagnosis of canine SLE. Cellulose acetate serum electrophoresis and immunoelectrophoretic techniques were each useful in supporting the diagnosis of multiple myeloma. Epizootiologic data collected in this study indicated that dogs with primary immunologic disease had a poor prognosis. A female predisposition was observed in cases of canine autoimmune hemolytic anemia and SLE. Ovariectomy seemed to prevent the development of canine SLE.

Agammaglobulinemia↗

Interrelationships between nutrient intake and plasma lipids and lipoproteins in schoolchildren aged 6 to 19: the Princeton School District Study.

Relationships between nutrient intakes and plasma lipids and lipoproteins were studied in 1,669 schoolchildren, aged 6 to 19 years; 948 were selected by random recall and 721 because of elevated plasma cholesterol or triglyceride (hyperlipidemic recall). Nutrient intake data was collected by using a 24-hour dietary recall. Median dietary cholesterol intakes for 6 to 9-year-old boys and girls in the random recall group were 222 and 230 mg/day, with polyunsaturated/saturated fat ratios of 0.34 and 0.33. For boys and girls, aged 10 to 12 years, median dietary cholesterol intakes were 296 and 235 mg/day, for 13 to 15 year olds, 343 and 237, and for 16 to 19 year olds, 418 and 221 mg/day. The dietary polyunsaturated/saturated fat ratios did not change appreciably with age. Partial correlation coefficients describing relationships between lipids, lipoproteins, and nutrients after adjustment for age, sex, race, and Quetelet index (W/H2) were calculated for all children (random and hyperlipidemic recall) after excluding children having plasma cholesterol, triglycerides, and calories less than or equal to the first or greater than or equal to the 99th percentiles for the random recall children. Plasma cholesterol was inversely and triglyceride positively correlated with dietary sucrose. Plasma low density lipoprotein cholesterol was inversely and triglyceride positively correlated with the dietary polyunsaturated/saturated fat ratio, total carbohydrate, and sugar. Potential relationships between nutrients and lipids-lipoproteins were also examined in children having low (first to tenth percentile), intermediate (45th to 55th percentile), and high (90th to 99th percentile) nutrient intake, after covariance adjustment for age, race, sex, and Quetelet index. Total plasma cholesterol fell as sucrose intake increased. Triglyceride rose along with caloric intake, total carbohydrate intake, and sucrose intake, while high density lipoprotein cholesterol levels fell with increasing caloric and sucrose intake. As dietary polyunsaturate ingestion rose from low to intermediate to high, plasma low density lipoprotein cholesterol increased. Nutrient intake may play a small but significant role relative to lipids and lipoproteins in children and, as such, may have importance relative to pediatric precursors of atherosclerosis.

Adolescent↗

The prevention and treatment of swimmer's shoulder.

Specific stroke modifications may be of great advantage to reduce shoulder pain in front crawl swimmers. Shortening the stroke by staring arm recovery the end of the push-through reduces "wringing-out" of the supraspinatus tendon. Lifting the head at arm entry, leading recovery with the hand and encouraging body roll and alternate breathing all reduce impingement of the tendon against the coraco-acromial arch. Specific stretching exercises, with neuromuscular facilitatory techniques, have an important preventative value. Proper sleeping posture is to be encouraged, using pillows to support the arm and reduce direct pressure over the supraspinatus tendon. Physical modalities and medication have a very limited role to play. Surgical decompression of the coracoacromial arch may be curative in those cases not responding to conservative management.

Biomechanical Phenomena↗