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Biomedical subjects

G P McCabe

Publications and source records attributed to G P McCabe.

At least 37 records · Page 2Linked to original sources
PubMed1995

Determination of structure-activity relationships of Annonaceous acetogenins by inhibition of oxygen uptake in rat liver mitochondria.

A new group of natural compounds, the Annonaceous acetogenins, have recently been determined to inhibit ATP production at a similar site of action and higher levels of potency as rotenone, i.e., at NADH-ubiquinone oxido-reductase, complex I of the mitochondrial electron-transport chain. The acetogenins had earlier been determined to be pesticidal, antimalarial, antimicrobial, anti-parasitic, cytotoxic, and in vivo active as potentially new antitumor agents. In order to determine structural activity relationships (SARs) among these compounds, at the subcellular level, several available acetogenins have been tested. Data obtained, from the inhibition of oxygen consumption by rat liver mitochondria, demonstrated that all of the twenty acetogenins tested are active with IC50 values in the range of 15-800 nM/mg protein. The IC50 value of rotenone was 17 nM/mg protein. The bis-adjacent THF ring acetogenins and the bis-nonadjacent THF ring compounds are about ten times more active than the mono-THF ring acetogenins. Overall, 30-OH and 31-OH-bullatacinone were the most active and were slightly more active than rotenone. The least active were the 4-deoxy bis-adjacent THF ring compounds followed by the mono-THF ring group. There was some variation between the groups, e.g., within the bis-adjacent and mono-THF ring groups, the alpha, beta-unsaturated-gamma-lactones were less active than the keto-lactones, but this observation was reversed for one of the pairs of bis-nonadjacent THF ring acetogenins. Additional hydroxylations, to a maximum of three, seemed to increase activity within all of the groups. Before final decisions on SARs can be made, additional comparisons of the results of this subcellular assay (as an in vitro assay) with the results of in vivo assays should be made. Also, future investigations into the exact site of action within complex I and other possible sites of action (such as the NADH oxidase of plasma membranes) need to be conducted for a more. complete understanding of the utility and potential of this new group of very potent compounds.

Acetylation↗
PubMed1995

Peak bone mass in young women.

Increasing peak bone mineral density (BMD) or content (BMC) in young women may help to reduce the incidence of osteoporosis. Identifying the age when peak bone content or density is attained is essential to develop strategies aimed at optimizing peak BMD and BMC. Total body bone mineral density (TBBMD) and content (TBBMC) were measured by a dual X-ray absorptiometer in healthy females (n = 247, aged 11-32 years). TBBMD and TBBMC were modeled separately as a nonlinear function of age. By age 22.1 +/- 2.5 years, 99% of peak BMD is attained, and by age 26.2 +/- 3.7 years, 99% of peak BMC is attained. Nonlinear relationships between weight and TBBMD or TBBMC were also modeled. In this model, the influence of several parameters, including age, weight, and height, on BMC and BMD were simultaneously assessed. A model with age and weight described the best fit for TBBMD, whereas age, weight, and height described the best fit for total body TBBMC.

Absorptiometry, Photon↗
PubMed1994

Relation of maternal zinc nutriture to pregnancy outcome and infant development in an Egyptian village.

Zinc nutriture of women living in a periurban Egyptian village was examined over the last 6 mo of pregnancy and the first 6 mo of lactation as one of several potential determinants of pregnancy outcome and infant development. Estimated bioavailable zinc intake was approximately 2 mg/d from diets high in phytate and fiber. Among numerous variables analyzed by multiple regression, early pregnancy weight (3 mo) and plasma zinc concentrations in the second trimester formed the best predictor model of birth weight, accounting for 39% of the variance. Bioavailable zinc intake during pregnancy was part of a profile of micronutrient intakes related to neonatal habituation behavior, a measure of early information processing. Performance on the Bayley motor test at 6 mo of age was negatively related to maternal intakes of plant zinc, phytate, and fiber, suggesting that zinc bioavailability was involved. Maternal dietary intake explained most of the variance observed in infant motor performance; however, predictive variance was amplified by the psychosocial context.

Adolescent↗
PubMed1994

Evaluation of resistance of four strains of commercial laying hens to experimental infection with Salmonella enteritidis phage type eight.

Four different strains of White Leghorn hens were orally infected with 1 x 10(8) cfu of Salmonella enteritidis phage Type 8 per bird. The birds were monitored for 10 wk postinfection for colonization of internal organs, fecal shedding of S. enteritidis, and the production of S. enteritidis-contaminated eggs. There was no difference among the four hen strains in regards to the probability of S. enteritidis isolation from liver and spleen, ovary, and cecal tissue within the first 30 d postinfection. However, during the first 14 d postinfection, S. enteritidis organisms were isolated in significantly higher rates from eggs and fecal samples of Strain A than from samples obtained from the other three hen strains. Results suggest that there may be inherent differences between strains of laying hens with regard to their response to infection with S. enteritidis.

Animals↗
PubMed1993

Diet during lactation associated with infant behavior and caregiver-infant interaction in a semirural Egyptian village.

Potential processes through which nutritional and non-nutritional factors can relate to infant state and behavior and mother-infant interactions were examined in 41 mother-infant pairs from semirural Egyptian households. All infants were breast-fed, and breast milk was the main source of their nutrient intake. Median birth weight was close to reference median; however, most infants showed growth faltering when they were 3-6 mo of age. Among the infant behavioral and state variables, only drowsiness (a proxy for activity and alertness) was significantly associated with the nutritional and non-nutritional factors examined. Among these factors, mothers' intakes of animal source foods and certain B vitamins were the strongest predictors of drowsiness. The nature of the association between maternal diet and drowsiness, examined by multiple regression analysis, showed clearly that inadequate diet of the mother was the major risk factor. Alertness of infants was further compromised when there were several children in the households. The small, less vocal and less alert infants received less vocalization from their mothers. In this environment, infants of undernourished mothers may not receive the extra care and stimulation needed and are at risk for subsequent developmental disabilities.

Behavior↗
PubMed1991

Determinants of pregnancy outcome and newborn behavior of a semirural Egyptian population.

Several potential determinants of birth weight and neonatal behavioral organization, ie, maternal anthropometry, food intake (energy, protein, and plant- and animal-source foods), morbidity, and household socioeconomic status, were followed systematically in a semirural Egyptian population during greater than or equal to 6 mo of pregnancy. In early pregnancy mothers were generally normal weight to moderately overweight. Their mean energy intake, largely from plant sources, was approximately 8.37 MJ/d (2000 kcal/d) during trimesters 2 and 3. Early (3 mo) pregnancy weight and weight gain during trimesters 2 and 3 were significantly positively related to birth weight Z scores. The best predictor model examined for birth weight included early pregnancy weight, weight gain, and length of gestation (R2 = 0.45). Early pregnancy weight and maternal intake of animal-source foods were significant positive predictors of the newborn's orientation and habituation behavior, respectively. Habituation and orientation measures assess the infant's early ability to process information.

Adult↗
PubMed1990

Vitamin B-6 status of Egyptian mothers: relation to infant behavior and maternal-infant interactions.

Functional consequences of marginal maternal vitamin B-6 status for behavior of the neonate and for mother-infant interactions at age 3-6 mo were assessed by a double-blind procedure. In 27 of 70 Egyptian village women studied, vitamin B-6 concentration of their milk was considered indicative of poor maternal vitamin B-6 nutriture. Neonatal behavior, quantified by the Brazelton Neonatal Behavioral Assessment Scale, showed that consolability, appropriate build-up to a crying state, and response to aversive stimuli were significantly correlated with maternal vitamin B-6 nutriture. Naturalistic observational procedures, used twice monthly with infants aged 3-6 mo, indicated that mothers assessed as having marginal vitamin B-6 status were less responsive to their infants' vocalizations, showed less effective intervention to infant distress, and were more likely to use older siblings as care-givers than were mothers of better vitamin status. We conclude that vitamin B-6 was a factor influencing both the behavior of the mother and her infant.

Adult↗
PubMed1990

Optimization of the under-agarose assay of porcine neutrophil migration.

Important procedural factors in the under-agarose assay for porcine neutrophil migration were identified, and optimal conditions were established. Three factors were tested: the concentration of zymosan-activated serum inoculated into the outer well; the number of neutrophils inoculated into the center well; and the time of incubation of the agarose plates. All factors had a significant (P less than 0.0001, 0.0001, and 0.01, respectively) effect on the chemotactic index of porcine neutrophils. The optimal combination of these 3 factors was undiluted zymosan-activated serum as the chemoattractant, 8 X 10(5) neutrophils inoculated into the center well, and 5 hours of incubation. The assay was validated, using standard conditions, and the data were used to predict the number of pigs and/or repetitive assays needed to identify differences among experimental groups.

Animals↗
PubMed1984

Non-work-related movements in machine-paced and self-paced work: an industrial study.

Non-work related movements (NWRM) of 10 experienced industrial workers performing light repetitive work were observed under a variety of conditions. More NWRM were observed for (1) machine-paced versus self-paced operations; and (2) a task with high mental load versus one with a low mental load. In addition, the age of the worker was found to be negatively correlated with NWRM.

Journal Article↗
PubMed1984

Reminders to physicians from an introspective computer medical record. A two-year randomized trial.

We developed a computer-stored medical record system containing a limited set of the total clinical data base--primarily diagnostic studies and treatments. This system responds to its own content according to physician-authored reminder rules. To determine the effect of the reminder messages generated by 1490 rules on physician behavior, we randomly assigned practitioners in a general medicine clinic to study or control groups. The computer found indications for six different actions per patient in 12 467 patients during a 2-year study: 61 study group residents who received computer reminders responded to 49% of these indications; 54 control group residents, to only 29% (p less than 0.0001). Preventive care (occult blood testing, mammographic screening, weight reduction diets, influenza and pneumococcal vaccines) was affected. The intentions of the study group to use a given action for an indication predicted their response to the indications (p less than 0.03, r2 = 0.33). The intentions of the control residents did not.

Computers↗
PubMed1982

Impact of personality and intelligence on job satisfaction of assembly line and bench work - an industrial study.

A study of the impact of machine-paced (M/P) and self-paced (S/P) work on job satisfaction of 28 female industrial assembly workers was evaluated in which M/P work was confounded with simplified work and the S/P job was confounded with enriched tasks. Results indicated the following: 1. Over three-quarters of workers were more satisfied in S/P jobs, while only less than one-quarter were more satisfied in M/P jobs. 2. The 16PF personality test effectively predicts (0.88 multiple correlation) the satisfaction ratios of M/P to S/P jobs.

Journal Article↗
PubMed1982

The effect of immediate access to a computerized medical record on physician test ordering: a controlled clinical trial in the emergency room.

We performed a randomized clinical trial of the effect of immediately printed summaries of a computerized medical record on physician test ordering rates in an Emergency Room setting. The computerized medical record contained medication history, the results of most diagnostic studies, an outpatient problem list, and inpatient and emergency room diagnoses. Physicians were presented with a printed summary of the patient's computerized record for study but not for control encounters. All other patient information was equally available to both kinds of encounters. All results were provided for one period of the study, designated T1. Due to a program error, summaries were printed without recent data during a period of the study, designated T2. Two-thirds of the visits were cared for by internists, one-third by surgeons. During T1, internists ordered an average of 3.2 tests, costing $34.91 for control visits, and 2.7 tests, costing $29.94 for study control visits (p less than .026). Surgeons also ordered fewer tests during study visits as compared to controls (1.32 vs 1.54) but the differences were not statistically significant. There was no significant effect on either medical or surgical test ordering during time period T2.

Clinical Laboratory Techniques↗
PubMed1980

Physician response to computer reminders.

A computerized medical record system was designed to detect and remind the responsible clinician about clinical events that might need corrective action. These reminders significantly increased the clinician response rate (in terms of test orders and treatment changes) to the events in question. The addition of relevant medical literature citations to the reminders did not significantly change the clinician response rate as compared with that with reminders alone, nor did it stimulate the physicians to read any of the cited articles kept in an immediately available "library" of reprints.

Clinical Competence↗
PubMed1977

Complexity of branching dendritic trees: dependence on number of trees per cell and effects of branch loss during sectioning.

We have investigated whether the complexity of dendritic trees is correlated with the number of primary dendrites per neuron (trees per cell). In estimating the average number of branches of centrifugal orders 1-5 per tree we used statistical methods to compensate for loss of parts of trees during sectioning. Limitations of these methods are discussed. Neurons from four populations, stained by the Golgi-Cox method, were examined: stellate cells from layer IV, area 17 of visual cortex, in normal and dark-reared cats; the pyramidal cells from layer V, somatosensory cortex, in two strains of rats. In all four groups of neurons the average number of branches of higher orders (3, 4, 5) per tree tended to be smaller in neurons bearing more trees. Thus all trees from a population of neurons should not be assumed to be equivalent. The decreasin high-order branches per tree tended to offset the increase in number of trees per cell. In three of the four groups these opposed tendencies maintained the average number of high-order branches per neuron nearly independent of the number of trees per cell. Natural selection may have favoured near-constancy in the number of high-order branches to reduce dispersion among neurons of one type in functional input-output rleations.

Animals↗
PubMed1977

Random censoring and dendritic trees.

The motivating problem is the estimation of the branching parameters of dendritic trees when some of the branches are cut. A primary element of this problem is the estimation of a bivariate discrete distribution when, because of partial censoring, some of the observations are incomplete. (This is similar to the problem of a multinomial cross-classification with supplemental partially cross-classified data.) Tests for randomness of censoring and estimators of parameters under random censoring are derived. The results on random censoring are applied in the dendritic tree context to obtain estimators for certain branching and cutting parameters. The testing and estimation procedures are applied to a set of dendritic tree data.

Dendrites↗