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PubMedDate not supplied

[Annual and circadian rhythms in plasma testosterone of five healthy young male Parisians (author's transl)].

Every other month, during the course of 14 months, the circadian rhythm in plasma testosterone (among others variables) of 5 healthy males (26 to 32 years) was documented. Subjects' synchronization : light-on at 07 +/- 1 hr; light-off at 23hr +/- 1.5 hr all the year long. Blood sampling 4-hourly, at fixed clock hours during 28 hrs, for radioimmunologic testosterone determinations. The cosinor method was used for statistical analyses. An annual rhythm in the testosterone 24-hr mean is detected (p less than 0.025) with a peak in October (from 16 July to 26 December, with 95% confidence limits). Annual mean (+/- 1 SE) - 759 (+/- 26)ng/100 ml. Peak-through difference = 107 ng/100 ml (from 106 to 290 with 95% confidence limits). The timing of the testosterone circadian peak, in the 24 hr-scale varies also in the course of the year. The peak is found around 08(00) in May and around 14(00) in November, this phase-shift being statistically significant (p less than 0.05). The sexual activity (daily self-recording) also has an annual rhythm with a peak in October.

Adult↗
PubMed1990

Comparative demographic and autopsy findings in acquired immune deficiency syndrome in two Mexican populations.

In order to identify the characteristics of the acquired immune deficiency syndrome (AIDS) as it occurs in Mexico, a comparative study of the demographic and pathological findings of the first 58 patients who died of AIDS and were autopsied at two Mexican hospitals, Hospital General de Mexico (HG) and Instituto Nacional de la Nutricion (INN), was performed. The patient population consisted of 52 men and 6 women. Their socioeconomic status (SES) was estimated using the occupational prestige and level of education as indicators. As in the U.S.A., most patients (72%) were male homosexuals/bisexuals (HMS/BSX). However, nine patients (31%) at the HG could not be assigned to any of the currently known risk groups. Comparison of the SES of the two series revealed a significantly higher number of poor patients at HG (81 vs. 17%). For the whole group, the most frequent infections were caused by cytomegalovirus (CMV) (65%), Mycobacterium tuberculosis (28%), Pneumocystis carinii (24%), and Toxoplasma gondii (17%). Kaposi's sarcoma (KS) was found in 41% of the cases. The frequency of toxoplasmosis was higher in poor patients (30 vs. 8%, odds ratio of 5.5, 95% confidence limits of 0.83, 39.34, p = 0.04) while the reverse situation was true for KS (18 vs. 61%, odds ratio of 0.14, 95% confidence limits of 0.04, 0.55, p = 0.001). For KS, this difference persisted when only HMS/BSX patients were compared. In conclusion, dissimilarities observed in the frequency of some AIDS-associated diseases in different institutions appear to be mainly influenced by the SES of the patients.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Determining compliance with a dietary fiber supplement.

The purpose of this pilot study was to evaluate possible ways to determine compliance with a dietary fiber supplement. A wheat bran supplement (30 g daily) significantly increased mean daily wet and dry stool weights (SW) in 7 adults, when compared to SW during an ad libitum low-fiber diet (paired t-test, P less than .01). Because unpaired data would be used during a clinical trial, distribution of the 7 ad libitum low-fiber mean SW observations was used to establish a reference distribution and an upper confidence limit against which the bran supplement SW could be compared. Only one of the seven bran supplement mean SW was above the confidence limit of the low-fiber period, independent of the number of days of collection (2-10) used to calculate the individual mean daily SW. Total fecal output over varying periods of time (2-10 days) suffered the same intersubject and intrasubject variability. Most (5-6) of the bran mean daily SW were above the group mean SW of the low-fiber period. However, this dose of bran was large enough to significantly decrease calcium absorption, and differences in SW produced by lower doses of wheat bran would probably not be as great. The bulk (greater than or equal to 80%) of a single dose of a fecal marker, chromium sesquioxide, which could be incorporated into a specific day's fiber supplement, was recovered in 5 days of excretion during the control period and in 4 days during the bran period. However, the blue color of the chromium before ingestion is clearly a negative feature. Another marker, polyethylene glycol, could not be recovered in excreta when transient time was 4 days or more. In a separate study, demonstration of very little overlap in the concentration of fecal neutral detergent fiber between the control and bran periods suggests that fecal fiber may be a marker of compliance with a fiber supplement.

Aged↗
PubMed1995

Relative bioavailability of different valproic acid formulations.

Relative bioavailability of valproic acid after oral administration of 2 Convulsofin (test) tablets each containing 300 mg calcium valproate (263.4 mg valproic acid) was studied versus 2 references (2 dragees each of 300 mg calcium valproate, ref.A, 600 mg sodium valproate in liquid form (258.7 mg valproic acid), ref.B). The controlled, randomized, clinical trial was performed in 16 healthy volunteers (12 males, 4 females, body weight 58-100 kg, Broca index 0.85-1.15) according to a 3-period changeover design with 7 days wash-out between 2 periods. Valproic acid was measured in serum with a GC method. Pharmacokinetic evaluation was done by compartment free methods. Test was considered bioequivalent with ref.A or ref.B with reference to extent of absorption if the 90% confidence interval of their AUC ratio was within the range of 0.80-1.25, and with respect to rate of absorption if the 90% confidence intervals of Cmax/AUC ratios were within 0.70-1.43. The point estimators (90% confidence limits) of the AUC ratios of test/ref.A and test/ref.B were 0.952 (0.882-1.028) and 1.063 (0.989-1.141), respectively. The point estimators (90% confidence limits) of Cmax/AUC ratios were 1.005 (0.923-1.094, test/ref.A) and 0.915 (0.845-0.991, test/ref.B). The following Cmax ratios were calculated: 0.957 (0.866-1.057, test/ref.A) and 0.972 (0.886-1.067, test/ref.B). No serious and unexpected adverse events were observed during the clinical trial. Test was bioequivalent with the 2 reference formulations ref.A and ref.B with respect to extent and rate of absorption. However, according to the secondary criterion tmax test tablets were more rapidly bioavailable than ref.A dragees (tmax-difference: -2.6 (-4.8 to -0.3 h) but more slowly (tmax-difference:+0.8 (-1.3 to +2.9 h) than ref.B juice.

Absorption↗
PubMed1996

Quantalization of continuous data for benchmark dose estimation.

Benchmark doses corresponding to low levels of noncancer disease risk have been proposed to replace the no-observed-adverse-effect level for establishing allowable daily intakes or reference doses. For quantal data each animal is classified with or without a disease. The proportion of animals with an adverse effect (risk) is observed as a function of dose of a toxic substance. The calculation of a benchmark dose is relatively straightforward. For continuous data a somewhat more complicated designation of risk is required. Because of the more direct procedures with quantal data, consideration could be given to converting continuous data to quantal data before estimating benchmark doses. The purpose of this paper is to compare the precision of the two approaches (use of continuous or quantalized data) for a number of sublinear dose-response curves ranging from low to high probabilities of risk at the highest dose. In these studies, five animals per dose were generally satisfactory to estimate the benchmark dose for continuous data, whereas the corresponding quantalized data generally do not perform as well even with 10 to 20 animals per dose. For quantalized data, the lower 95% confidence limits on the estimates of the benchmark dose were generally a factor of 3 to 4 below the true benchmark dose, whereas the confidence limits using the continuous data were generally within a factor of 2 of the true benchmark dose. Although the use of quantalized data for the estimation of risk is more direct, estimates of benchmark doses using the continuous data were more precise. Based on this study, converting continuous data to quantal data is not recommended.

Animals↗
PubMed1978

A stochastic locomotor control model for the nurse shark, Ginglymostoma cirratum.

The locomotor behavior of the nurse shark (Ginglymostoma cirratum) is characterized by 17 variables (frequency and ratios of left, right, and total turns; their radians; straight paths (steps); distance travelled; and velocity) Within each of these variables there is an internal time dependency the structure of which was elaborated together with an improved statistical model predicting their behavior within 90% confidence limits. The model allows for the sensitive detection of subtle locomotor response to sensory stimulation as values of variables may exceed the established confidence limits within minutes after onset of the stimulus. The locomotor activity is well described by an autoregression time series model and can be predicted by only seven variables. Six of these form two independently operating clusters. The first one consists of: the number of right turns, the distance travelled and the mean velocity; the second one of: the mean size of right turns, of left turns, and of all turns. The same clustering is obtained independently by a cluster analysis of cross-sections of the seven time series. It is apparent that, among a total of 17 locomotor variables, seven behave as individually independent agents, presumably controlled by seven separate and independent centers. The output of each center can only be predicted by its own behavior. In spite of the individual of the seven variables, their internal structure is similar in important aspects which may result from control by a common command center. The shark locomotor model differs in important aspects from the previously constructed for the goldfish. The interdependence of the locomotor variables in both species may be related to the control mechanisms postulated by von Holst for the coordination of rhythmic fin movements in fishes. A locomotor control model for the nurse shark is proposed.

Animals↗
PubMed1987

Large sample confidence intervals for regression standardized risks, risk ratios, and risk differences.

Several methods have been proposed for standardizing risks, risk ratios, and risk differences based on the results of logistic regression. These methods provide an alternative to direct standardization, a particularly useful approach when there are many covariates. In this paper, methods for calculating approximate confidence limits for these standardized measures are presented. A simple example, in which published data are used, illustrates the techniques and allows comparison with confidence limits calculated from the directly standardized risk ratio.

Aged↗
PubMed1986

Evaluation of liver weight changes following repeated administration of carbon tetrachloride in rats and body-liver weight relationship.

The proper method of evaluating liver weight changes resulting from the primary toxic effect of a chemical was studied. We used a pair-feeding method with carbon tetrachloride (CCl4), a chemical known to cause an increase in liver weight. Male rats were assigned to an untreated control group, CCl4-treated groups (daily dose of 10 microliter or 50 microliter of CCl4 in olive oil/100 g body wt), olive oil-treated plus feed-restricted groups, and feed-restricted groups. In the 2 types of feed-restricted groups the body weight changes of the CCl4-treated groups were duplicated by imposing restrictions on feeding. Absolute and relative liver weights were compared among the 4 types of groups after treatment for 14 or 25 days. Either absolute or relative liver weight of the treated group when compared to that of the feed-restricted group was the most reliable and sensitive toxicity indicator. In comparing the treated group with the untreated control group, relative liver weight was a more sensitive toxicity indicator than absolute liver weight. However, when liver weight data for about 200 normal male rats were plotted against body weight, and the 95% confidence limits of the regression line (y = ax) were estimated, most of the data for the feed-restricted rats were outside the lower confidence limit. This means that a comparison of the relative liver weights of the treated rats and untreated control rats is not strictly valid, because the body weight-liver weight relationships are not the same in the 2 groups.

Administration, Oral↗
PubMed2002

Use of alternative therapies for menopause symptoms: results of a population-based survey.

OBJECTIVE: To describe self-reported prevalence of the use of alternative therapies for menopause symptoms and subject characteristics associated with their use. METHODS: A telephone survey of 886 women aged 45-65 years (87.2% response rate) was conducted at Group Health Cooperative in Washington state. Women were asked about eight alternative therapies and their use for menopause symptoms. RESULTS: The proportion of women who used each therapy was 76.1% for any therapy, 43.1% for stress management, 37.0% for over-the-counter alternative remedies, 31.6% for chiropractic, 29.5% for massage therapy, 22.9% for dietary soy, 10.4% for acupuncture, 9.4% for naturopath or homeopath, and 4.6% for herbalists. The proportion of women who used it to manage menopause symptoms was 22.1% for any therapy, 9.1% for stress management, 13.1% for over-the-counter alternative remedies, 0.9% for chiropractic, 2.6% for massage therapy, 7.4% for dietary soy, 0.6% for acupuncture, 2.0% for naturopath or homeopath, and 1.2% for herbalists. Among women who used these therapies, 89-100% found them to be somewhat or very helpful. A history of breast cancer was associated with a six-fold increase in use of dietary soy for menopause symptoms (odds ratio 6.23, 95% confidence limits 2.54, 15.28). Current users of hormone replacement therapy were half as likely to use alternative remedies or providers (odds ratio 0.48, 95% confidence limits 0.29, 0.77) as were never users. Sleep disturbances were associated with a four-fold increase in the use of body work, a three-fold increase in the use of stress management, and more than doubled the use of dietary soy products to manage menopause symptoms. CONCLUSION: The use of alternative therapies for menopause symptoms is common, and women who use them generally find them to be beneficial. Physicians should routinely ascertain perimenopausal women's use of alternative therapies.

Aged↗
PubMed1995

Oxygen desaturation on swallowing as a potential marker of aspiration in acute stroke.

We have assessed the measurement of oxygen saturation (SaO2) as a means of detecting aspiration in patients with stroke. For 10 weeks all acute stroke [AS] admissions were seen within 48 hours. Basal SaO2 was measured by pulse oximetry. Patients swallowed 10ml water while sitting up and SaO2 was noted for 2 minutes. Two control groups [young, fit (YF) and inpatient age- and sex-matched, non-neurological disease (IP)] underwent the same assessment. AS subjects underwent independent assessment of swallowing by a speech and language therapist (SLT). Exclusion criteria comprised impaired consciousness, other neurological disease and chest infection. Forty-nine AS subjects [20 men; aged 46-93 (mean 71) years], 55 YF [26 men; aged 18-55 (mean 32) years] and 65 IP [28 men; aged 53-96 (mean 71) years] were studied. Mean (SD) SaO2 fall in AS subjects [2.6 (2.9)%)] was significantly more than in YF [1.1 (0.8)%] or IP [1.1 (0.9)%]. The lower 95% confidence limit for variation in SaO2 did not differ between YF and IP (3.0% 'fall'); 19 (39%) AS subjects desaturated below this 95% lower confidence limit. Mean (SD) SaO2 fall was significantly more in SLT-graded 'aspirators' [4.6 (2.7)%] than 'nonaspirators' [1.4 (1.0)%]. We conclude that (1) a fall in SaO2 on swallowing fluid is common in patients with acute stroke; (2) the presence or absence of desaturation agrees statistically with SLT assessment of aspiration; (3) SaO2 measures may aid bedside assessment of swallowing.

Adolescent↗
PubMed1979

Assessment of protein nutrition in surgical patients--the value of anthropometrics.

In order to evaluate the reliability of anthropometry in assessing protein stores we have compared, in 10 normal adults and 82 surgical patients with varying degrees of weight loss, measurements of weight/height, arm circumference, arm muscle circumference, and arm muscle area with direct measurements of body nitrogen using in vivo neutron activation analysis. Anthropometry is reliable for the assessment of protein nutrition in groups of patients (for 100 patients 95% confidence limits are +/- 30 g nitrogen) but the magnitude of variance shown makes it inappropriate for assessing the individual as a single measurement (95% confidence limits are +/- 300 g nitrogen). Repeat measurements were made after 2 weeks on 35 patients and there was no correlation between changes in body nitrogen and changes in the anthropometric measurements. Anthropometry is not reliable in following changes in body nitrogen in individual patients over short periods of time.

Adult↗
PubMed1997

Type I diabetic pregnancy and subclinical human papillomavirus infection.

It has been suggested that diabetic pregnancy is an immunosuppressive state. To determine whether the possible immunosuppression in pregnant diabetics might result in an increased risk for human papillomavirus (HPV) infection, we studied exfoliated cells from the uterine cervix, vagina, and posterior commissure of the vulva by means of dot blot hybridization with use of a probe cocktail of HPV types 11, 16, and 18 under low stringency and by means of consensus primer-mediated polymerase chain reaction (PCR) targeted to the HPV L1 and E1 regions. For this study, samples from 31 pregnant diabetics whose glucose levels had been reasonably well controlled were analyzed during the first trimester; samples from 27 of these patients were analyzed again during the third trimester. Fifty-one healthy pregnant women were included as controls. Only one of the pregnant diabetics was positive for HPV DNA. The L1 PCR products of the first and third trimester samples from this patient were sequenced, and both were found to represent HPV 61. Three of the pregnant controls were positive for HPV: two were positive for HPV 16, and one was positive for HPV 6. The 95% confidence limits for the prevalence of HPV were calculated to be 0.1%-16.7% for the diabetics and 1.2%-16.2% for the controls. The 95% confidence limits for the difference between the groups were -11.6%-6.3%. These results suggest that pregnant diabetics do not have an increased risk of developing HPV infection, at least when their glucose levels remain well controlled.

Adult↗
PubMed1992

An outbreak of hepatitis A associated with swimming in a public pool.

A multistate outbreak of hepatitis A was traced to a campground in Louisiana. Among 822 campers during one weekend, 20 developed hepatitis A. Case-patients ranged in age from 4 to 36 years; the highest attack rate (6.4%) was for children aged 5-9 years. A case-control study revealed that case-patients were more likely than controls to have swum in a public swimming pool on Saturday afternoon (19/19 vs. 26/38; odds ratio [OR], undefined; lower 95% confidence limit, 1.7). Case-patients were more likely than controls to have swum in the jacuzzi pool (16/19 vs. 10/26; OR, 8.0; 95% confidence interval, 1.5-47.1) or adult pool A (19/19 vs. 15/26; OR, undefined; lower 95% confidence limit, 2.6). Case-patients were also more likely to have swum for greater than 1 h and to have put their heads under the water. Because of the design of the filtering system of adult pool A, a cross-connection between a sewage line and the pool water intake line was possible. This outbreak may have been caused by transmission of hepatitis A through swimming; thus, swimming may serve as a mode of transmission of hepatitis A virus, especially among small children.

Adolescent↗
PubMed1987

Epicardial repolarization mapping in man.

A simple method was developed for recording epicardial monophasic action potentials intraoperatively in man. Potentials were recorded rapidly and reliably from multiple epicardial sites using a hand-held probe. The feasibility of repolarization mapping was assessed in 30 patients. It was possible to record technically adequate signals from most left ventricular and posterior right ventricular sites (success rates 72% and 61%, respectively), but it was more difficult to achieve satisfactory recordings over the free wall of the right ventricle (success rate 36%). The onset of cardiopulmonary bypass resulted in a transient rise in action potential duration of approximately 30-40 ms in the first minutes of bypass. An approximate steady state was achieved thereafter. Reproducibility of the method was assessed by mapping a small number of sites repeatedly. The 95% confidence limits for an estimate of repolarization time, based on a single potential, were +/- 21 ms. With 4 probe applications at each site, the confidence limits of the estimated site mean were reduced to +/- 8 ms. Based on this approach, statistically significant differences between sites were demonstrated in 9 of 10 patients, confirming that the method is sensitive enough to provide information on regional differences in repolarization. Intraoperative epicardial repolarization mapping has been shown to be a practical possibility. The technique holds promise as a means of assessing the role of dispersion of repolarization in arrhythmogenesis in man.

Action Potentials↗
PubMed1986

Measurement of axial rotation of vertebrae in scoliosis.

The authors report a radiographic method for measuring the axial rotation of vertebrae in degrees and its use in 99 patients with adolescent idiopathic scoliosis. The offset of the pedicle images from the vertebral body center and a "depth" estimate measured radiographically in a population of patients with scoliosis permitted calculation of axial rotation by means of a simple mathematical formula. It was found that measurements of vertebral rotation can be made clinically from single-plane radiographs with a standard deviation of 3.6 degrees (95% confidence limit +/- 7.1 degrees) based on a study of known rotations of a radiographic phantom, and with a standard deviation of 2.44 degrees (95% confidence limit +/- 4.8 degrees) based on comparisons with three-dimensional measurements of the orientation of each vertebra derived from low-dose stereo films of a group of patients. Measurements from clinical films are unlikely to be made more accurately than this, because of inherent geometric constraints.

Adolescent↗
PubMed2004

Quantitative risk assessment for developmental neurotoxic effects.

Developmental neurotoxicity concerns the adverse health effects of exogenous agents acting on neurodevelopment. Because human brain development is a delicate process involving many cellular events, the developing fetus is rather susceptible to compounds that can alter the structure and function of the brain. Today, there is clear evidence that early exposure to many neurotoxicants can severely damage the developing nervous system. Although in recent years, there has been much attention given to model development and risk assessment procedures for developmental toxicants, the area of developmental neurotoxicity has been largely ignored. Here, we consider the problem of risk estimation for developmental neurotoxicants from animal bioassay data. Since most responses from developmental neurotoxicity experiments are nonquantal in nature, an adverse health effect will be defined as a response that occurs with very small probability in unexposed animals. Using a two-stage hierarchical normal dose-response model, upper confidence limits on the excess risk due to a given level of added exposure are derived. Equivalently, the model is used to obtain lower confidence limits on dose for a small negligible level of risk. Our method is based on the asymptotic distribution of the likelihood ratio statistic (cf. Crump, 1995). An example is used to provide further illustration.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed2001

A modified National Institutes of Health Stroke Scale for use in stroke clinical trials: preliminary reliability and validity.

BACKGROUND AND PURPOSE: The National Institutes of Health Stroke Scale (NIHSS) is accepted widely for measuring acute stroke deficits in clinical trials, but it contains items that exhibit poor reliability or do not contribute meaningful information. To improve the scale for use in clinical research, we used formal clinimetric analyses to derive a modified version, the mNIHSS. We then sought to demonstrate the validity and reliability of the new mNIHSS. METHODS: The mNIHSS was derived from our prior clinimetric studies of the NIHSS by deleting poorly reproducible or redundant items (level of consciousness, face weakness, ataxia, dysarthria) and collapsing the sensory item into 2 responses. Reliability of the mNIHSS was assessed with the certification data originally collected to assess the reliability of investigators in the National Institute of Neurological Disorders and Stroke (NINDS) rtPA (recombinant tissue plasminogen activator) Stroke TRIAL: Validity of the mNIHSS was assessed with the outcome results of the NINDS rtPA Stroke Trial: RESULTS: Reliability was improved with the mNIHSS: the number of scale items with poor kappa coefficients on either of the certification tapes decreased from 8 (20%) to 3 (14%) with the mNIHSS. With the use of factor analysis, the structure underlying the mNIHSS was found identical to the original scale. On serial use of the scale, goodness of fit coefficients were higher with the mNIHSS. With data from part I of the trial data, the proportion of patients who improved >/=4 points within 24 hours after treatment was statistically significantly increased by tPA (odds ratio, 1.3; 95% confidence limits, 1.0, 1.8; P=0.05). Likewise, the odds ratio for complete/nearly complete resolution of stroke symptoms 3 months after treatment was 1.7 (95% confidence limits, 1.2, 2.6) with the mNIHSS. Other outcomes showed the same agreement when the mNIHSS was compared with the original scale. The mNIHSS showed good responsiveness, ie, was useful in differentiating patients likely to hemorrhage or have a good outcome after stroke. CONCLUSIONS: The mNIHSS appears to be identical clinimetrically to the original NIHSS when the same data are used for validation and reliability. Power appears to be greater with the mNIHSS with the use of 24-hour end points, suggesting the need for fewer patients in trials designed to detect treatment effects comparable to rtPA. The mNIHSS contains fewer items and might be simpler to use in clinical research trials. Prospective analysis of reliability and validity, with the use of an independently collected cohort, must be obtained before the mNIHSS is used in a research setting.

Clinical Trials as Topic↗
PubMedDate not supplied

Lack of relationship between the Cleveland Health Quality Choice project and decreased inpatient mortality in Cleveland.

The Cleveland Health Quality Choice (CHQC) project was previously suggested to have been responsible for declines in inpatient mortality in Cleveland hospitals during the first years of the project (1992-1993). We sought to (a) verify this decline in mortality and (b) better understand its possible relationship to CHQC. We employed regression analysis to compare mortality rate trends for Cleveland versus the rest of Ohio using Ohio Hospital Association inpatient mortality data. We found that the rate of decline in mortality in Cleveland (-.218% per 6 months; 95% confidence limits, -.278% to -.159% per 6 months) was statistically indistinguishable from that in the rest of the state (-.188% per 6 months; 95% confidence limits, -.234% to -.143% per 6 months) (P = .35). We could not demonstrate a significant beneficial effect of the CHQC project on hospital mortality in Cleveland. Inpatient mortality was simultaneously declining at a statistically indistinguishable rate throughout the state.

Health Services Research↗