PubMed Health⌕ Search

Biomedical subjects

B Hsi

Publications and source records attributed to B Hsi.

14 recordsLinked to original sources
PubMed1997

Prognostic Factors Related to Recovery from Diarrhea among U.S. Students with Diarrhea in Mexico.

Background: Medical charts of subjects treated with placebo from five double-blinded placebo-controlled clinical trials were reviewed to determine pre-enrollment prognostic factors related to later recovery from diarrhea. Method: Recovery or time from initiation of a placebo until passage of the last unformed stool after being declared well was calculated for each subject. Results: A longer duration of diarrhea was associated with presence of fever (rate ratio = 0.34; 95% CI = 0.2-0.9), presence of an invasive pathogen in the stool (rate ratio = 0.35; 95% CI = 0.2-0.7) or a noninvasive pathogen in stool (rate ratio = 0.7; 95% CI = 0.6-1.0), severe abdominal pain or cramps (rate ratio = 0.5; 95% CI = 0.3-0.9), passage of more than five watery stools per 24 hours (rate ratio = 0.58; 95% CI = 0.4-0.8). Severe vomiting predicted a shorter duration of post-enrollment diarrhea (rate ratio = 2.43; 95% CI = 1.1-5.6). Conclusion: A number of clinical and microbiologic factors found in travelers with diarrhea in the present study predicted duration of untreated diarrhea. The authors suggest the use of antimicrobial therapy in travelers with predictors of a long duration of diarrhea. Data developed in the present study may be used to create a historical control for clinical trials of antidiarrheal compounds using the same study criteria.

Journal Article↗
PubMed1994

Pharmacologic intervention can reestablish baseline hemodynamic parameters during laparoscopy.

BACKGROUND: Several studies in both animal models and human beings have shown that CO2 abdominal insufflation for laparoscopy can cause a variety of alterations in hemodynamic and pulmonary physiology. These physiologic changes could potentially have deleterious effects in patients with underlying cardiopulmonary disease. METHODS: We prospectively evaluated 15 patients with preexisting heart and/or lung disease to determine whether the use of invasive monitoring would allow early identification and treatment of these physiologic alterations and thus enable laparoscopy to be performed safely in this group of patients. RESULTS: CO2 abdominal insufflation caused statistically significant increases in systemic vascular resistance, mean arterial pressure, left ventricular stroke work index, and pulmonary capillary wedge pressure along with a concomitant decrease in cardiac index and oxygen delivery in these patients. The use of intravenous nitroglycerin resulted in a rapid return of the systemic vascular resistance, mean arterial pressure, pulmonary capillary wedge pressure, and cardiac index to baseline levels. No significant intraoperative or postoperative cardiac or pulmonary complications were noted. CONCLUSIONS: These results suggest that laparoscopy with CO2 pneumoperitoneum can be safely performed in high-risk patients if appropriate monitoring and pharmacologic interventions are used.

Aged↗
PubMed1990

Circadian variation in human performance evaluated by the Walter Reed performance assessment battery.

As part of a two clock-time (0830 versus 2030) evaluation of administration-time dependent effects of dexedrine (5 mg) and triazolam (0.25 mg) on human cognitive performance, placebo (control) studies were conducted on 12 diurnally active (0700-2300) male adults (23-38 yrs) using a double-blind, randomized crossover design. Testing was conducted hourly during a series of sleepless 13-hr spans commencing in the morning or evening, using the Walter Reed computer controlled and scored multi-task cognitive performance assessment battery. For the placebo condition, Single and Group Cosinor analyses documented circadian rhythms in performance for most tasks (reaction time, logical reasoning, serial add/subtract and spatial orientation) both for individuals and the group. Overall, performance was worse overnight, when sleepiness was greatest, and best between 1830 and 2030. It was most variable around 0600-0700. The day-night variation in performance over all cognitive tests amounted to 21% of the 24-hr mean.

Adult↗
PubMed1989

Circadian rhythms in hot flashes in natural and surgically-induced menopause.

The aim of this study was to investigate circadian and ultradian variations in menopausal hot flash. The number of hot flashes per 2-hr period was collected from 25 diurnally-active, perimenopausal women for 1 week in January or February of each year for 3 consecutive years. Fourteen women were experiencing natural menopause (NM) (mean age 51.9 years) and 11 were experiencing surgically-induced menopause (SIM) (mean age 52.0 years). The difference in the number of hot flashes between the two types of menopause at each clock time was not statistically significant; neither was the mean number of hot flashes per 24 hr different between the two groups (Student's t-test). Data when normalized for each woman and placed end-to-end revealed by cosinor analysis circadian rhythmicity in the SIM group (P = 0.02) but not in the NM group. A 12-hr periodicity was detected in both groups (P less than 0.001 for both). An 8-hr rhythm was detected only for the NM group (P = 0.04). Both groups combined exhibited statistically significant rhythmicities with periods of 24 hr (P = 0.003), 12 hr (P less than 0.001) and 8 hr (P = 0.005). Regardless of the type of menopause, the women could be separated into two groups based on the temporal pattern of hot flashes during the day. One group was defined by the occurrence of peak frequency of flashes during the morning (0400-0959), while the second group was defined by the occurrence of the peak in the evening (1600-2159).(ABSTRACT TRUNCATED AT 250 WORDS)

Activity Cycles↗
PubMed1987

Field survey of circadian rhythm in PEF of electronics workers suffering from colophony-induced asthma.

Twenty-two British electronics workers suffering from occupationally-induced asthma due to their exposure to colophony fumes self-recorded their peak expiratory flow (PEF) every 1-2 hr throughout the waking span for at least two weeks, both during work and vacation periods. Data were analyzed by a two-step procedure using the statistical techniques of Single and Population Mean Cosinor analyses. The objective endpoints of mesor (24-hr mean), amplitude (measure of 24-hr rhythmic variation) and acrophase (peak time along the scale of 24 hr) for the time-spans of the work-week (Monday-Friday), weekend after work (Saturday-Sunday) and vacation weekdays and vacation weekends were compared. The PEF data of four workers who participated in the study for nearly one year also were evaluated for seasonal variation. A statistically significant difference (P less than 0.04) was detected in the PEF amplitude between work and vacation weeks; the difference in the PEF mesor and acrophase between work-weekdays and work-weekends achieved near or statistical significance (P = 0.07 and 0.05, respectively). The at-work amplitude was higher and the acrophase earlier timed. There was no statistically significant difference between work-week and weekend-after-work PEF mesors. Winter PEF mesors were significantly lower than summer ones in the four subjects self-measuring their bronchial patency over the year. Overall, the findings indicate that data obtained through employee surveys, using lightweight portable and inexpensive PEF Wright meters and analyzed by statistical analyses used in the field of biological rhythm research, yield objective evidence of occupationally associated decrements in pulmonary function resulting from colophony fume exposure.

Adult↗
PubMed1987

Comparison of sustained-release theophylline scheduled conventionally (twice-daily, equal interval in equal amount) versus once-daily mornings or evenings on circadian pattern of bronchial patency in asthmatics.

The effects of differently timed, but equivalent TheoDur (Key Pharmaceutical Co.) dosage schedules--twice-daily equally divided 12 hr (BID), once-daily evening (OD-PM) and once-daily morning (OD-AM)--were compared under steady-state conditions in 10 adult asthmatics with a documented history of nocturnal dyspnea. Assessments of airways function by spirometry were done every 3-hr over one complete 24-hr dosing interval for each dosage schedule under carefully controlled conditions. The different TheoDur regimens did not affect the 24-hr group average FEV1.0, PEF, MMEF or FVC. However, statistically significant circadian variation in airways function existed irrespective of the drug dosing schedule. Airways patency and FVC were least overnight (0200-0500 hr) and best during the morning or afternoon. With regard to FEV1.0 and PEF, which evidenced group circadian change for BID and OD-PM regimen by Cosinor analysis, the peak-to-trough (double amplitude) difference expressed as a percentage of the 24-hr average was rather large, being greatest for the OD-PM schedule (20.5% for FEV1.0 and 24.3% for PEF). The data for the 10 participants revealed individual differences in the effectiveness of the 3 studied theophylline dosing regimens when assessed in terms of the mean level and stability of airways function over the 24 hr. Based on the findings, neither the BID, OD-PM nor the OD-AM regimen effectively moderated the nocturnal deterioration of pulmonary function suggesting theophylline as dosed and timed may not be as efficacious as desired for patients with a history of strictly nighttime dyspnea. Thus, the schedule and prescription of TheoDur must take into account differences between patients, including the time when asthma symptoms are most likely to be experienced by each.

Adult↗
PubMed1981

Immunological studies of the human placenta: functional and morphological analysis of pregnancy-associated plasma protein A (PAPP-A).

A blood protein, pregnancy-associated plasma protein A (PAPP-A), has been isolated from the plasma of pregnant women. An antiserum to this protein has been prepared and used to localize the protein within the placenta by immunofluorescence. It was found to be inconstantly present in the syncytiotrophoblast and intervillous fibrin. Neither antiserum nor antigen exerts a cytotoxic effect on peripheral blood lymphocytes, and neither affected blastogenic responses of lymphocytes to mitogens or in mixed lymphocyte culture reactions.

Cytotoxicity, Immunologic↗
PubMed1980

The human materno-foetal relationship in malaria. II. Histological, ultrastructural and immunopathological studies of the placenta.

Histological and ultrastructural studies of four placentae heavily infectd with Plasmodium falciparum revealed large intervillous accumulations of erythrocytes containing parasites together with monocytes which had ingested pigment. These appearances were associated with focal syncytial necrosis, loss of syncytial microvilli and proliferation of cytotrophoblastic cells. In addition, marked irregular thickening of trophoblastic basement membranes and protrusion of tongue-like projections of syncytiotrophoblast into the basement membrane were observed. In six other placentae which contained scanty amounts of pigment but no parasites, representing past or inactive infection, no large collections of monocytes or abnormalities of trophoblast were apparent but basement membrane thickening was evident. Immunohistological studies revealed no significant differences between placentae positive for parasites and those containing pigment only, although the amount of certain immunoproteins and clotting factors was clearly increased above normal. These findings establish that P. falciparum infection in the placenta may result in substantial damage although lesions within the villus are rare. Furthermore, previous infection, although adequately controlled, may leave a heritage of pigment deposition, basement membrane thickening and immunopathological lesions. These results may thus account for both the high frequency of intra-uterine growth retardation and the rarity of congenital malaria in the presence of P. falciparum malaria.

Female↗
PubMedDate not supplied

Chronobiometry with pocket calculators and computer systems.

Selected methods for the study of biologic time series are reviewed and their relative merits are discussed in the light of underlying assumptions. Their potential applications are exemplified in several fields of biology and medicine. The monitoring of environmental integrity, notably of pollution, is investigated. The need for specifying optimal sampling requirements is underlined. An individualized and time-qualified definition of health by the establishment of reference intervals is required for increasingly rational individualized program for the prevention and/or treatment of disease. With these reference intervals and rhythm characteristics available, one can better interpret with single samples or time series an increased risk of a certain disease or the inception of the disease. For all of these aims the monitoring of environmental and/or personal marker rhythms is essential--to obtain large data bases from which information can be more easily derived for monitoring personal health, to recognize risk as well as to diagnose disease early and to optimize treatment by timing according to rhythms.

Animals↗
PubMedDate not supplied

Statistical methods that distinguish between attributes of assessment: prolongation of life versus quality of life.

The authors propose a method to generate information relevant to the decision tree that adds additional perspective to the characterization of health quality during survival. Their approach uses survival data to distinguish two attributes of utility: prolongation of life and quality of life (QOL). Health-state transition probabilities correspond to the prolongation of life and are modeled in a discrete-time transient semi-Markov process. Quality-of-life-state transition probabilities are derived from the assumptions of a simple recurrent Markov process. They reflect events within the health-state sojourn time that differentiate perceptions of pain and suffering over a short fixed time period. Outcomes for these two dimensions of utility are highly relevant to the assessment of medical technology that might prolong life at the cost of increased pain and suffering, implying a reduced QOL. The methods are demonstrated on a subset of follow-up data from the Beta-Blocker Heart Attack Trial (BHAT).

Adult↗
PubMedDate not supplied

Utilization of commercial laboratory results in management of hyperandrogenism in women.

OBJECTIVE: To compare results from testosterone radioimmunoassay kits commonly used by commercial laboratories as well as their reference ranges and to analyze the scientific literature for ranges of serum testosterone levels in normal women and those with hyperandrogenism. METHODS: We reviewed quality assurance reports of various testosterone ligand challenges from four groups of laboratories and summarized testosterone data from 17 published reports about normal women and 14 studies of hyperandrogenic women. RESULTS: A significant variability was demonstrated between the radioimmunoassay kits at all concentrations (for example, a sample with a mean testosterone level of 96.1 ng/dL was reported by some laboratories as containing 71.8 ng/dL and by others as 123.4 ng/dL). All laboratories provide essentially the same "reference range" (approximately 10 to 90 ng/dL) but do not report how the range was established. The scientific literature clearly shows a significant separation in serum testosterone levels between normal (that is, not hyperandrogenic) and hyperandrogenic women. Most hyperandrogenic women had testosterone levels >50 ng/dL, whereas most normal control subjects had levels <40 ng/dL. Thus, most of these women with hyperandrogenism would have been considered to have normal testosterone levels if the reference ranges of commercial laboratories were used. CONCLUSION: These data illustrate the difficulty that physicians face when they are required to use different commercial laboratories to measure serum testosterone levels. We propose that (1) reference ranges be established on a clinically defined population for each hormone and method used, (2) laboratory reports include information about method and reference range population, and (3) physicians be allowed to choose which laboratories are used for their patients' hormone determinations, for consistency of results.

Journal Article↗
PubMedDate not supplied

Higher corticosterone values at a fixed single timepoint in serum from mice "trained" by prior handling.

Results of "training" rodents for bioassay of synthetic corticosteroids are not consistent with expectations presumably based upon earlier implied claims stemming, perhaps, from over behavioral patterns displayed by handled as compared to nonhandled rodents (or the observer's wishful thinking?). At the timepoints investigated, "habituation" of mature mice and rats by exposure to handling, injection and killing procedures results in statistically significantly increased corticosterone concentrations. For younger animals the elevation in corticosterone concentration may also be applicable; although, it is not known to what extent we are dealing with an effect of "habituation" and/or age. Lowest hormone concentration occurred in the groups of mice housed undisturbed in an animal chamber separate from the room housing mice subjected to habituation. The results of this study suggest that for certain rodents kept in L from 0600 to 1800 "habituation" for 1 week, at least at the circadian stage corresponding to 0800, is not only ineffectual (in eliminating the rise in serum corticosterone associated with handling) but detrimental to the evaluation of synthetic corticosteroid potency by bioassay (to the extent that such a rise in exaggerated rather than reduced). In these acute experiments, methylprednisolone was more suppressive than dexamethasone and the water soluble ester-salts less suppressive than the 21-hydroxy bases. These results suggest the possibility of important differences in the distributive stage and/or the metabolism of these compounds--factors affecting the speed of onset of the desired as well as undesired effects.

Adrenal Cortex Hormones↗