Biomedical subjects

J Patrie

Publications and source records attributed to J Patrie.

9 recordsLinked to original sources

PubMed2004

Are men at greater risk for Parkinson's disease than women?

Parkinson's disease seems to occur more commonly in men than women based primarily on studies of death rates and prevalence. In recent years, several population based incidence studies of Parkinson's disease that included sex data have been conducted in a variety of populations around the world. To investigate whether these incidence studies suggest an increased risk of Parkinson's disease in men, a meta-analysis was performed of the differences in incidence of Parkinson's disease between men and women reported in seven studies that met the inclusion criteria. A significantly higher incidence rate of Parkinson's disease was found among men with the relative risk being 1.5 times greater in men than women. Possible reasons for this increased risk of Parkinson's disease in men are toxicant exposure, head trauma, neuroprotection by oestrogen, mitochondrial dysfunction, or X linkage of genetic risk factors.

Cross-Cultural Comparison↗

PubMed2002

Unequal impact of short-term testosterone repletion on the somatotropic axis of young and older men.

The present clinical study compares the impact of low- and high-dose parenteral testosterone (T) supplementation on daily GH secretory patterns and serum IGF-I, IGFBP-1, and IGFBP-3 concentrations in healthy older (60-82 yr) and young (20-40 yr) men. To this end, we administered three consecutive weekly injections of randomly ordered saline and either a low (100 mg) or a high (200 mg) dose of testosterone enanthate im; namely, saline (n = 17, young and n = 16, older), a low dose (n = 8 young, n = 8 older) and a high dose (n = 9 young, and n = 8 older) of androgen. To monitor somatotropic-axis responses, blood was sampled every 10 min for 24 h for later chemiluminescence-based assay of serum GH, RIA of serum IGF-I, and immunoradiometric assay of serum IGFBP-1 and IGFBP-3 concentrations. Data were analyzed via a nested analysis of covariance statistical design. At baseline (saline injection), older, compared with young, men maintained: 1) similar serum total T, IGFBP-1, and IGFBP-3 but reduced IGF-I concentrations, namely, mean (+/- SEM) IGF-I 160 plus or minus 15 vs. 280 plus or minus 18 microg/liter, (P < 0.001); 2) reduced GH secretory burst mass (0.68 +/- 0.09 vs. 1.2 +/- 0.20 microg/liter, P = 0.031); 3) more disorderly GH release patterns (approximate entropy 0.501 +/- 0.058 vs. 0.288 +/- 0.021, P < 0.001); and 4) blunted 24-h rhythmic GH output (nyctohemeral amplitude 0.25 +/- 0.05 vs. 0.47 +/- 0.08 microg/liter, P = 0.025). Serum T concentrations (ng/dl) did not differ in the two age groups supplemented with either a low dose [550 +/- 50 (young) and 544 +/- 128 (older)] and high [1320 +/- 92 (young) and 1570 +/- 140 (older)] dose of T. The 100-mg dose of androgen exerted no detectable effect on GH secretion in either age cohort but increased the serum IGF-I concentration in young men by 20% (P = 0.00098). The 200-mg dose of T failed to alter daily GH production in young volunteers but in older men stimulated: 1) a 2.03-fold rise in the mean (24-h) serum GH concentration (P = 0.0053, compared with the response to saline); 2) a 1.20-fold increase in basal (nonpulsatile) GH production (P = 0.039); 3) a 2.15-fold amplification of GH secretory burst mass (P = 0.0020); 4) a 2.17-fold elevation of the Mesor of nyctohemeral GH output (P = 0.025); 5) a 1.79-fold enhancement in GH approximate entropy (P = 0.0003); and 6) a 40% increase in the fasting serum IGF-I concentration (P = 0.000005). Multivariate statistical analysis indicated that following high-dose T administration, the E2 increment significantly predicted the IGF-I increment in both age groups combined (P = 0.003); T dose positively forecast the serum total IGF-I concentration (P = 0.0031); and age and T dose jointly determined serum LH concentrations (P = 0.031). In summary, neither a physiological nor a pharmacological dose of T administered parenterally for 3 wk augments daily GH secretion in eugonadal young men. In contrast, a high dose of aromatizable androgen significantly amplifies 24-h basal, pulsatile, entropic, and nyctohemerally rhythmic GH production and elevates the serum IGF-I concentration in older men. The mechanistic basis for the foregoing age-related distinction in GH/IGF-I axis responsivity to T is not known.

Aged↗

PubMed2001

Abdominal visceral fat and fasting insulin are important predictors of 24-hour GH release independent of age, gender, and other physiological factors.

Numerous physiological factors modulate GH secretion, but these variables are not independent of one another. We studied 40 younger (20-29 yr.; 21 men and 19 women) and 62 older (57-80 yr.; 35 men and 27 women) adults to determine the contributions of several demographic and physiological factors to the variability in integrated 24-h GH concentrations. Serum GH was measured every 10 min for 24 h in an enhanced sensitivity chemiluminescence assay. The predictor variables included: age group (young or old), gender, abdominal visceral fat (by computed tomography), total body fat mass and percentage body fat by dual-energy x-ray absorptiometry, serum IGF-I, fasting serum insulin, 24-h mean estradiol and testosterone, and peak oxygen uptake by graded exercise (treadmill) testing. Multiple ordinary least squares regression analysis was used to quantitatively assess the individual contribution that each predictive measure made to explain the variability among values of integrated 24-h GH concentrations while in the presence of the remaining predictors. The model explained 65% of the variance in integrated 24-h GH concentrations. Abdominal visceral fat (P < 0.002) and fasting insulin (P < 0.008) were consistently important predictors of integrated 24-h GH concentrations independent of age group, gender, and all other predictor variables. Although serum IGF-I was an important overall predictor of integrated 24-h GH concentrations (P = 0.002), this relationship was present only in the young subjects and was modulated by gender. The remaining variables failed to contribute significantly to the model. We conclude that abdominal visceral fat and fasting insulin are important predictors of integrated 24-h GH concentrations in healthy adults, independent of age and gender. Serum IGF-I is an important predictor of integrated 24-h GH concentrations in young but not older subjects. Bidirectional feedback between each of these three factors and GH secretion may account for the strong relationships observed.

Abdomen↗

PubMed2000

Alterations in growth and body composition during puberty. IV. Energy intake estimated by the youth-adolescent food-frequency questionnaire: validation by the doubly labeled water method.

BACKGROUND: Estimates of energy intake are required for an understanding of growth and disease; however, few methods of energy intake in children have been validated. OBJECTIVE: Our objective was to validate energy intake estimated by the Youth-Adolescent Food-Frequency Questionnaire (YAQ) against the criterion total energy expenditure (TEE) by doubly labeled water (DLW). DESIGN: Twenty-three boys and 27 girls (8.6-16.2 y of age) completed the YAQ and TEE measurements in 1 y. RESULTS: Energy intake by the YAQ (10. 03 +/- 3.12 MJ) and energy expenditure by DLW (9.84 +/- 1.79 MJ) were similar (P: = 0.91) with large lower (-6.30 MJ) and upper (6.67 MJ) +/-2 SD limits of agreement. When within-subject CVs of repeated measures of the DLW and YAQ methods were used, 25 of the 50 subjects were deemed to have misreported their energy intake. The discrepancy in energy intake (YAQ - TEE) was related to body weight (r = -0.25, P: = 0.077) and percentage body fat (r = -0.24, P: = 0.09) but not to age (r = -0.07, P: = 0.63) or the time between measures. From logistic regression, fatter boys were more likely to underreport energy intake than were fatter girls. CONCLUSION: The YAQ provides an accurate estimation of mean energy intake for a group but not for an individual.

Adolescent↗

PubMed2000

Pathogenesis of primary R5 human immunodeficiency virus type 1 clones in SCID-hu mice.

We studied the replication and cytopathicity in SCID-hu mice of R5 human immunodeficiency virus type 1 (HIV-1) biological clones from early and late stages of infection of three patients who never developed MT-2 cell syncytium-inducing (SI; R5X4 or X4) viruses. Several of the late-stage non-MT-2 cell syncytium-inducing (NSI; R5) viruses from these patients depleted human CD4(+) thymocytes from SCID-hu mice. Earlier clones from the same patients did not deplete CD4(+) thymocytes from SCID-hu mice as well as later clones. We studied three R5 HIV-1 clones from patient ACH142 in greater detail. Two of these clones were obtained prior to the onset of AIDS; the third was obtained following the AIDS diagnosis. In GHOST cell infection assays, all three ACH142 R5 HIV-1 clones could infect GHOST cells expressing CCR5 but not GHOST cells expressing any of nine other HIV coreceptors tested. Furthermore, these patient clones efficiently infected stimulated peripheral blood mononuclear cells from a normal donor but not those from a homozygous CCR5Delta32 individual. Statistical analyses of data obtained from infection of SCID-hu mice with patient ACH142 R5 clones revealed that only the AIDS-associated clone significantly depleted CD4(+) thymocytes from SCID-hu mice. This clone also replicated to higher levels in SCID-hu mice than the two earlier clones, and a significant correlation between viral replication and CD4(+) thymocyte depletion was observed. Our results indicate that an intrinsic property of AIDS-associated R5 patient clones causes their increased replication and cytopathic effects in SCID-hu mice and likely contributes to the development of AIDS in patients who harbor only R5 quasispecies of HIV-1.

Animals↗

PubMed2000

Pubertal alterations in growth and body composition. V. Energy expenditure, adiposity, and fat distribution.

We determined whether activity energy expenditure (AEE, from doubly labeled water and indirect calorimetry) or physical activity [7-day physical activity recall (PAR)] was more related to adiposity and the validity of PAR estimated total energy expenditure (TEE(PAR)) in prepubertal and pubertal boys (n = 14 and 15) and girls (n = 13 and 18). AEE, but not physical activity hours, was inversely related to fat mass (FM) after accounting for the fat-free mass, maturation, and age (partial r = -0.35, P < or = 0.01). From forward stepwise regression, pubertal maturation, AEE, and gender predicted FM (r(2) = 0.36). Abdominal visceral fat and subcutaneous fat were not related to AEE or activity hours after partial correlation with FM, maturation, and age. When assuming one metabolic equivalent (MET) equals 1 kcal. kg body wt(-1). h(-1), TEE(PAR) underestimated TEE from doubly labeled water (TEE bias) by 555 kcal/day +/- 2 SD limits of agreement of 913 kcal/day. The measured basal metabolic rate (BMR) was >1 kcal. kg body wt(-1). h(-1) and remained so until 16 yr of age. TEE bias was reduced when setting 1 MET equal to the measured (bias = 60 +/- 51 kcal/day) or predicted (bias = 53 +/- 50 kcal/day) BMR but was not consistent for an individual child (+/- 2 SD limits of agreement of 784 and 764 kcal/day, respectively) or across all maturation groups. After BMR was corrected, TEE bias remained greatest in the prepubertal girls. In conclusion, in children and adolescents, FM is more strongly related to AEE than activity time, and AEE, pubertal maturation, and gender explain 36% of the variance in FM. PAR should not be used to determine TEE of individual children and adolescents in a research setting but may have utility in large population-based pediatric studies, if an appropriate MET value is used to convert physical activity data to TEE data.

Adipose Tissue↗

PubMed2000

High-versus low-threshold surfactant retreatment for neonatal respiratory distress syndrome.

UNLABELLED: Surfactant therapy has become an effective standard therapy for infants with respiratory distress syndrome (RDS). The first dose may be given either as prophylaxis immediately after delivery, or as rescue after an infant has developed RDS. Second and subsequent doses are currently recommended by the manufacturers to be administered at minimal levels of respiratory support. PURPOSE: This study compared the relative efficacy of administering second and subsequent doses of Infasurf surfactant at a low threshold (FIO(2) >30%, still requiring endotracheal intubation) versus a high threshold (FIO(2) >40%, mean airway pressure >7 cm H(2)O) of respiratory support. METHODS: A total of 2484 neonates received a first dose of surfactant; 1267 reached conventional retreatment criteria and were randomized to be retreated according to low- or high-threshold criteria. They were then retreated at a minimum of 6-hour intervals each time they reached their assigned threshold until receiving a maximum of 4 total doses. Subjects were stratified by whether they received their first dose by prophylaxis or rescue and by whether their lung disease was considered complicated (evidence of perinatal compromise or sepsis) or uncomplicated. RESULTS: Among the patients randomized, 33% of prophylaxis and 23% of rescue subjects met criteria for the complicated stratum. Although infants allocated to the high-threshold strategy were receiving slightly more oxygen at 72 hours, there was no difference in the number receiving mechanical ventilation at 72 hours or in the secondary respiratory outcomes (requirement for supplemental oxygen or mechanical ventilation at 28 days, supplemental oxygen at 36 weeks' postconceptional age, inspired oxygen concentration >60% at any time). However, there was a significantly higher mortality for infants with complicated RDS who had received retreatment according to the high-threshold strategy. CONCLUSIONS: We conclude that equal efficacy can be realized by delaying surfactant retreatment of infants with uncomplicated RDS until they have reached a higher level of respiratory support than is the current standard. We speculate that this would result in a substantial cost-saving from less utilization of drug. Conversely, we believe that infants with complicated RDS should continue to be treated by the low-threshold retreatment strategy, which is currently recommended by the manufacturers of the commercially available surfactants.

Biological Products↗

PubMed2000

Rib fracture patterns and radiologic detection--a restraint-based comparison.

This paper presents a study of the rib fracture patterns generated in simulated frontal collisions and the visibility of the rib fractures on plain film radiographs. Using 29 cadaver subjects, rib fractures were identified on oblique, lateral, and anteroposterior chest films by five radiologists independently and were compared with fractures found during a detailed necropsy. Physical, geometric, and experimental factors demonstrated an influence on the ability of a radiologist to identify rib fractures on an x-ray. Specifically, the restraint system configuration, the total number of fractures, the circumferential location of the fracture, the rib number, and the aspect (right or left) affected fracture identification. The results verify that torso belt loading produces rib fractures generally located along the path of the belt whereas superimposed airbag loading results in a more distributed and posterolateral fracture pattern. A higher proportion of rib fractures was identified on x-ray for occupants restrained by only a belt (44% of fractures) than for occupants restrained by both a belt and an airbag (24% of fractures). Overall, less than 40% of the rib fractures were detected upon an initial examination of radiographs. After being provided with the location of all fractures, detection increased to 49%. On average, occult rib fractures resulted in an average underreporting of injury severity of more than one AIS level.

Acceleration↗

PubMedDate not supplied

A model for predicting motor urge urinary incontinence.

BACKGROUND: While the historical interview has been shown to diagnose stress urinary incontinence (UI) with reasonable accuracy, it is less accurate in the diagnosis of urge or mixed UI. OBJECTIVES: To construct an optimal model for the diagnosis of motor urge UI, and to refine this model into a simplified instrument that can be used to diagnose motor urge UI during a routine incontinence evaluation. METHODS: A model was constructed to allow a more accurate diagnosis of motor urge UI using historical data. Initially, an optimal model was developed that used three key symptoms, age, gender, a history of neurologic disorder, obstruction diagnosed via voiding pressure study, and the urethral resistance algorithm to diagnose motor urge UI. A simplified model was then constructed using factors such as symptoms of motor urge UI, age, and gender that were readily accessible to the nurse when completing a routine UI evaluation. This simplified model was used to develop an instrument for the clinical diagnosis of motor urge UI. RESULTS: While the agreement between clinical and urodynamic diagnosis was relatively high among patients with genuine stress UI (93% accuracy rate), it was considerably less among patients with urge and mixed UI, yielding accuracy rates of 63% and 35%, respectively. An optimal model for diagnosing motor urge UI was constructed and provided an overall accuracy rate of 91%. A simplified model was then constructed and evaluated for performance by least squares fit test. It revealed an R2 of 0.85 and an adjusted R2 of 0.84. CONCLUSIONS: A combination of age, gender, and three key symptoms (diurnal frequency, nocturia, and symptom of urge incontinence) provide an accurate and clinically useful model for the diagnosis of motor urge UI. Additional research is recommended to test the validity and reliability of the instrument derived from this model.

Adolescent↗