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Biomedical subjects

K F O'Brien

Publications and source records attributed to K F O'Brien.

34 records · Page 2Linked to original sources

Comparison between two methods of hydrostatic weighing without head submersion in morbidly obese females.

This study compared two methods of hydrostatic weighing without head submersion to conventional hydrostatic weighting in morbidly obese females. We concluded that hydrostatic weighing without head submersion is a valid alternative to conventional hydrostatic weighing especially when subjects are apprehensive in the water. The use of anthropometric head measures (HWNS-A) did not significantly improve the accuracy of the body composition assessment; therefore, elimination of these time consuming measurements in favor of the direct correction of head above Db is recommended.

Body Composition↗

Sensitivity and specificity of current methods for classifying morbid obesity.

This study examined the sensitivity and specificity of current methods for classifying morbid obesity in females. Results suggest that current methods for classifying morbid obesity (greater than or equal to 45.5 kg over ideal weight or BMI greater than or equal to 45) do not provide acceptable specificity and sensitivity, respectively. We suggest that additional measurements such as total body fatness determined by hydrodensitometry be used to classify morbid obesity and determine eligibility for aggressive therapeutic interventions for weight loss.

Adult↗

Trend analysis for repeated measures designs.

This paper outlines a method of analysis that is well-suited to repeated measures designs. This method uses polynomial functions of time to characterize an outcome variable measured at several distinct time points on the same subjects. Profiles for different treatment groups may be compared using the appropriate interaction terms in an analysis of variance table. The method is illustrated with data from two recent studies.

Absenteeism↗

Liver pathology in morbidly obese patients with and without diabetes.

The contribution of obesity and/or diabetes to liver pathology in the morbidly obese patient is controversial. We studied the liver biopsies of 100 consecutive patients undergoing gastric bypass surgery for morbid obesity. Multiple morphologic parameters were analyzed and graded independently, without knowledge of the clinical history, liver function tests, and oral glucose tolerance results of the patients. Six percent of the entire group demonstrated no fat, 42% mild fat, 20% moderate fat, and 24% severe fatty metamorphosis of the liver. Twenty-three percent of the patients had central vein fibrosis, 23% sinusoidal fibrosis, 19% bridging fibrosis, and 4% cirrhosis. Thirty-six percent of the patients had some degree of steatohepatitis, 66% possessed so-called glycogen nuclei of hepatocytes, 6% had PAS-positive thickening of blood vessels in the portal tracts, and 1% had lipogranulomas. The degree of fatty metamorphosis and fibrosis was analyzed in three separate groups, categorized by the glycemic status of the patient: 46 patients with normal glucose tolerance (NGT), 23 patients with impaired glucose tolerance (IGT), and 31 patients with non-insulin-dependent diabetes mellitus (NIDDM). Increasing severity of fatty metamorphosis from the normoglycemic obese to the diabetic obese patients was found, which was statistically significant by chi 2 analysis. Four of the six patients showing no fatty metamorphosis were normoglycemic. Glycogen nuclei and PAS-positive blood vessels were significantly more prevalent in the diabetic obese than in the normal obese. In conclusion, the distribution of significant liver histopathology in the morbidly obese patient correlates in severity with the degree of impaired glycemic status.

Adult↗

White blood cell response to uphill walking and downhill jogging at similar metabolic loads.

The object of this study was to determine whether leukocytosis would occur in response to eccentric exercise, to concentric exercise, and/or to possible increases in serum cortisol levels. Eight men performed 2 bouts of exercise at 46% VO2max for 40 min. Subjects initially walked up a 10% grade (UW); 2 weeks later they jogged down a 10% grade (DJ), a form of eccentric exercise known to induce delayed onset muscle soreness (DOMS). Venous blood samples were drawn before and after each exercise bout (0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, and 5 h). Total and differential WBCc and serum cortisol levels were assessed. Results were analyzed using repeated measures ANOVA (2 x 11). Subjects experienced severe DOMS after DJ. There was a significant difference in TWBCc (p less than 0.0001) between UW and DJ. Post-hoc testing revealed no significant increase over baseline values for UW; after DJ there was a 46% increase over baseline values (p less than 0.05) initially seen at 1.0 h. These increases in TWBCc were predominantly a reflection of increases in neutrophils which were significant (p less than 0.0001) when compared to baseline values at 1.0, 1.5 and 2.0 h (approximately 60%). No significant neutrophil increases were seen after UW. Cortisol levels were similar for both groups pre-exercise (UW = 367.1 +/- 38.6, DJ = 320.2 +/- 44.16 nmol.L-1 means +/- SE) and decreased similarly for both groups after exercise, and thus were not related to the post-exercise neutrophilia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Hydrostatic weighing without head submersion in morbidly obese females.

This study tests the validity of hydrostatic weighing without head submersion (HWNS) for determining the body density (Db) of morbidly obese (MO) females. Eighty MO females who were able to perform traditional hydrostatic weighing at residual volume (HW) underwent four counterbalanced trials for each procedure (HW and HWNS) to determine Db. Residual volume was determined by oxygen dilution. Twenty subjects were randomly excluded from the experimental group (EG) and assigned to a cross-validation group (CV). Simple linear regression was performed on EG data (n = 60, means = 36.8 y, means % fat = 50.1) to predict Db from HWNS (Db = 0.569563 [Db HWNS] + 0.408621, SEE = 0.0066). Comparison of the predicted and actual Db for CV group yielded r = 0.69, SEE = 0.0066, E statistic = 0.0067, mean difference = 0.0013 kg/L. The SEE and E statistic for body fat were 3.31 and 3.39, respectively. Mean difference for percent fat was 0.66%. Results indicate that HWNS is a valid technique for assessing body composition in MO females.

Adult↗

Hydrostatic weighing without head submersion: description of a method.

Hydrostatic weighing (HW) was performed at residual volume (RV) and total lung capacity without head submersion (TLCNS). Ninety-five males (25.6 +/- 4.9 yr) and 87 females (22.6 +/- 5.2 yr) were studied at two laboratory sites using identical protocols. Twenty males and 20 females were separated from the original group and randomly assigned to cross-validation groups. RVs were determined by the oxygen dilution method. Vital capacity was determined with the subject submerged in water to the shoulders. Underwater weight was determined using 10 trials at RV and 5 trials at TLCNS, with the order of methods randomly assigned. Regression analysis provided an equation to predict body density (pDb) at RV from body density (Db) at TLCNS. The equation for males was pDb (HW at RV) = 0.5829 (DbHW at TLCNS) + 0.4059, r = 0.88, SEE = 0.0067. The equation for females was pDb (HW at RV) = 0.4745 (DbHW at TLCNS) + 0.5173, r = 0.85, SEE = 0.0061. Cross-validation showed no significant differences using Db from HW at RV (males = 1.0626 g.ml-1, females = 1.0493 g.ml-1 and pDb from HW at TLCNS (males = 1.0625 g.ml-1, females = 1.0479 g.ml-1). The correlation coefficient SEE and total error for males were r = 0.95, 0.0043, and 0.0041, respectively and for females r = 0.82, 0.0084, and 0.0085, respectively. Mean percent fat for RV and TLCNS was identical for males and differed by 0.7% for females. Test-re-test data indicated the TLCNS procedure was reliable (r = 0.98).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Note on the choice of statistic for testing hypotheses regarding seasonality.

The Kolmogorov-Smirnov one-sample test and the Pearson chi-square test are discussed regarding their application for testing hypotheses of seasonality in births. This paper addresses some points mentioned in an earlier paper by McCullough and argues that the chi-square procedure may be the better test.

Biometry↗

The effects of exercise on lipogenic enzyme activity and glyceride synthesis by liver homogenates of diabetic rats.

The purpose of this study was to determine if exercise ameliorates the elevated levels of triglycerides in diabetic rats and also to determine if the capacity of liver to synthesize glycerides correlates with changes in plasma triglyceride levels. Forty female rats were divided into four groups: sedentary control, sedentary diabetic, exercised control, and exercised diabetic. Diabetes was induced by intravenous injection of alloxan (40 mg/kg), and control rats were sham-dosed with physiologic saline. All rats remained sedentary in their cages for the first week after the injections. The exercised groups were exercised for seven consecutive days for 2 h/d at 20 m/min (0 grade). All rats were killed 24 hours after the last exercise bout. Blood glucose levels were significantly higher in the diabetic group than the nondiabetic counterparts, but exercise did not affect glucose levels in either the diabetic or nondiabetic groups. Exercise, however, significantly lowered plasma triglyceride and free fatty acid levels in both diabetic and nondiabetic rats. The activities of the five enzymes involved in fatty acid synthesis were all depressed in the diabetic rats compared to controls, and exercise had no effect on the activities of the enzymes. The capacity of liver to synthesize total lipids, diglycerides, or triglycerides was not different in the diabetic rats from that of nondiabetic rats, and exercise did not change that. Only phospholipid synthesis from glycerol-3-phosphate was affected by diabetes. It is concluded that exercise ameliorates the elevations in plasma triglyceride levels that result from diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Acute posttraumatic stress disorder in victims of a natural disaster.

Five months after a tornado devastated a rural community in eastern North Carolina, the authors surveyed the mental health status of 116 disaster victims, using the Hopkins Symptom Checklist (HSCL) expanded to include most of DSM-III criteria for posttraumatic stress disorder (PTSD). A total of 69 (59%) victims met the criteria for acute PTSD, 19 of whom had a severe form. Although an inadequate degree of social support was more often noted in victims with severe PTSD, other demographic factors and degree of injury or property damage did not appear to be related to the presence of PTSD. Severity or presence of PTSD was supported by high scores on all HSCL subscale factors. These findings suggest a high incidence of acute PTSD in victims of natural disasters and the potential value of HSCL in screening for PTSD in large populations.

Acute Disease↗

Faculty input in book selection: a comparison of alternative methods.

In an era of tight funding, academic medical center libraries need to determine their users' needs in order to provide cost-effective resource collections. Although faculty input is valuable, it is impractical to impose such ongoing responsibility on faculty members. This study tested an alternative method by comparing faculty preferences in discipline-specific subjects with faculty choices on corresponding discipline-specific, new-book approval slips from a vendor. Collection development librarian selections, based on formal selection criteria, were evaluated against both measures of faculty preferences. It was found that faculty members' subject ratings did not accurately predict their book choices. Implications of this and the other findings are discussed.

Book Selection↗

Foundation care: a treatment model for nonambulatory profoundly mentally retarded persons.

Two treatment models, Intermediate Care Facilities for the Mentally Retarded (ICF/MR) and Foundation Care, were compared with respect to their use in the institutional treatment of nonambulatory profoundly mentally retarded persons. Foundation Care is focused on physical and social environmental components of caregiving through emphases on health, nourishment, nurturance, stimulation, and play, with the goal of habilitation. Subjects were randomly assigned to the treatment models. We hypothesized that when compared to ICF/MR, the Foundation Care unit would use more resident-oriented management practices, have different caregiver resident interaction, and have residents who would exhibit more behavioral complexity. Baseline, 6-month, and 1-year measurements were made. Results supported the first and third hypotheses. Caregiver resident interaction was similar for both groups; however, Foundation Care staff used more tactile modalities and contingent interaction. We conclude that Foundation Care may be an appropriate alternative level of care for the nonambulatory profoundly retarded person.

Adult↗

Dystrophin and muscular dystrophy: past, present, and future.

Duchenne muscular dystrophy was described in the medical literature in the early 1850s but the molecular basis of the disease was not determined until the late 1980s. The cloning of dystrophin led to the identification of a large complex of proteins that plays an important, although not yet well understood, role in muscle biology. Concomitant with the elucidation of the function of dystrophin and its associated proteins has been the pursuit of therapeutic options for muscular dystrophy. Although there is still no cure for this disorder, great advances are being made in the areas of gene introduction and cell transplant therapy.

Animals↗

Diagnostic accuracy and role of immediate interpretation of fine needle aspiration biopsy specimens from various sites.

A statistical analysis of the accuracy of the immediate interpretation of 425 fine needle aspiration (FNA) biopsies from various sites was performed. Preliminary interpretation of Diff-Quik-stained smears was rendered within a few minutes after performing the FNA biopsy, using diagnostic terminology similar to that of a surgical pathology report. The immediate assessment was documented in the formal cytology report and compared to the final diagnosis. For the entire series, the immediate interpretation had a sensitivity of 96%, a specificity of 97%, a positive predictive value (PV) of 98%, a negative PV of 95% and an efficiency of the test of 96%. There were 14 false-negative or falsely insufficient immediate interpretations and one false-positive immediate diagnosis. The diagnostic accuracy of the immediate interpretation of FNA biopsies from specific sites was also calculated; FNA biopsies of the pancreas were the least accurate procedure, having a sensitivity of 60% but a specificity of 100%. The role of the immediate interpretation of FNA biopsies is similar to the use of frozen sections in surgical pathology. An immediate assessment can (1) determine whether an adequate specimen is present, (2) render a specific preliminary diagnosis, (3) guide further clinical investigations or treatment, and (4) determine whether ancillary studies are needed to make a more accurate or specific diagnosis from the FNA specimen. Our results indicate that the immediate interpretation of FNA biopsies is an accurate procedure that should be routinely employed.

Biopsy, Needle↗