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Biomedical subjects

J Schulte

Publications and source records attributed to J Schulte.

At least 55 records · Page 3Linked to original sources
PubMed1996

Natural history of human immunodeficiency virus disease in perinatally infected children: an analysis from the Pediatric Spectrum of Disease Project.

OBJECTIVE: To describe the progression of human immunodeficiency virus (HIV) disease through clinical stages from birth to death among a large number of perinatally infected children. METHODS: The Pediatric Spectrum of Disease (PSD) project, coordinated by the Centers for Disease Control and Prevention (CDC), has conducted active surveillance for HIV disease since 1988 in seven geographic regions. PSD data are collected from medical and social service records every 6 months through practitioners at each participating hospital clinic. We analyzed data from perinatally HIV-infected children born between 1982 and 1993. The natural history of HIV disease was divided into five progressive stages using the clinical categories in the CDC 1994 pediatric HIV classification system: stage N, no signs or symptoms; stage A, mild signs or symptoms; stage B, moderate signs or symptoms; stage C, severe signs or symptoms; and stage D, death. A five-stage Markov model was fitted to the PSD data. To compare the estimates from the PSD project with the published estimates, we also fitted an alternative Markov model using acquired immunodeficiency syndrome (AIDS; 1987 case definition) in place of stage C and also calculated standard Kaplan-Meier estimates. RESULTS: A total of 2148 perinatally HIV-infected children were included in the analysis. The estimated mean times spent in each stage were: N, 10 months; A, 4 months; B, 65 months; and C, 34 months. We estimated that a child born with HIV infection has a 50% (95% confidence interval [CI], 40%-60%) chance of severe signs or symptoms developing by 5 years of age and a 75% (95% CI, 68%-82%) chance of surviving to 5 years of age. For a child in stage B, there is a 60% (95% CI, 49%-71%) chance of severe signs or symptoms developing within the next 5 years and a 65% (95% CI, 56%-73%) chance of surviving 5 more years. The estimated mean time from birth to stage C was 6.6 (95% CI, 5.7-7.5) years, and the estimated mean survival time from birth was 9.4 (95% CI, 8.1-10.7) years. From the alternative Markov model, the estimated mean time from birth to AIDS was 4.8 (95% CI, 4.5-5.2) years. CONCLUSION: Markov modeling using the revised pediatric classification system allowed us to describe the natural history of HIV disease in children before diagnosis of AIDS. On average, children progress to moderate symptoms in the second year of life and then remain moderately symptomatic for more than half of their expected lives, underscoring their need for clinical care before the onset of AIDS. The results from the Markov model are useful in family counseling, health care planning, and clinical trial designs.

Acquired Immunodeficiency Syndrome↗
PubMed1996

[Comparison of sevoflurane and isoflurane in ambulatory surgery. Results of a multicenter study].

UNLABELLED: A multicenter, randomized, comparative phase III study evaluating the effect of sevoflurane versus isoflurane in adult outpatients was performed. The aim of the study was to compare (1) maintenance of anaesthesia and (2) how rapidly and easily the patients emerge from the anaesthetic and recover. METHODS: Outpatients were included who underwent scheduled surgical procedures of an anticipated duration of up to 3 h and an anticipated length of hospitalization of less than 24 h post-anaesthesia. Five hundred patients were randomly selected to receive either sevoflurane (n = 247) or isoflurane (n = 253), each administered with oxygen (30-50%) in nitrous oxide. Efficacy was evaluated through the measurement of times of recovery parameters and tests like the objective pain-discomfort scale, the visual analogue scale, and the digit symbol substitution test. Safety was evaluated by monitoring adverse experience, clinical laboratory and non-laboratory testing and physical assessments. RESULTS: No statistical differences were observed between the two treatment groups with respect to demographics and ASA class. All study drug concentrations during each anaesthetic phase were statistically lower in the sevoflurane (average concentration 0.61 MAC) compared to the isoflurane (average concentration 0.70 MAC) group. The mean time to emergence was statistically shorter in the sevoflurane group (8.2 min) than in the isoflurane group (9.3 min). The mean time to response to commands (8.5 min vs 9.8 min) and the mean time to orientation (10.6 min vs 13.0 min) were also statistically shorter in the sevoflurane than in the isoflurane group. The EEG results showed a faster decrease in delta activity and a faster increase in alpha activity in the sevoflurane group than in the isoflurane group, indicating faster awakening. No statistical differences were observed between the two treatment groups for the mean time to any of the remaining post-anaesthesia events. Bradycardia was observed in a statistcally higher percentage of patients in the sevoflurane group (6%) than in the isoflurane group (2%). No other statistical differences were observed between the two treatment groups concerning the incidence of study drug-related adverse experience. The most common adverse experiences were nausea and vomiting. At all post-anaesthesia time points, higher serum inorganic fluoride concentrations were observed in the sevoflurane (maximum 30.2 mumol/l) than in the isoflurane group. No clinical or laboratory renal insufficiency was noted. Eighty-seven percent of patients in the sevoflurane group would request the same anaesthetic technique compared to only 79% of patients in the isoflurane group. CONCLUSIONS: Sevoflurane was as safe as isoflurane for anaesthesia in adult outpatients. Patients who received sevoflurane had statistically significantly shorter recovery parameters than isoflurane patients.

Adolescent↗
PubMed1995

Development of a propidium iodide fluorescence assay for proliferation and cytotoxicity assays.

A propidium iodide fluorescence assay (PIA) was developed to characterize the in vitro growth of human tumor cell lines as well as to test the cytotoxic activity of standard compounds. Propidium iodide (PI) was used as a dye which penetrates only damaged cellular membranes. Intercalation complexes are formed by PI with double-stranded DNA which effect an amplification of the fluorescence. Incubation of the total cell population with PI and subsequent fluorescence detection allowed assessment of the number of non-vital cells (first measurement). After freezing the cells at -20 degrees C for 24 h PI had access to total DNA leading to total cell population counts (second measurement). The number of viable cells was calculated by the difference between these two measurements. In the proliferation and cytotoxicity assays 5 x 10(3) cells per well were plated in 96 multiwells and finally stained with 50 micrograms/ml PI in 25 microliters for 10 min. A correlation between the log of cell number and the log of fluorescence units could be demonstrated over a 2.5-3 log range (r = 0.97). The lower limit of cell detection was 150-500 cells/wells. In cytotoxicity assays eight clinically used cytostatics were tested which effected a clear dose-response relationship (r = 0.93-0.98) and high reproducibility (r = 0.92). In conclusion, this assay is a simple and rapid test system, the main advantages are the absence of any washing steps and the small number of tumor cells necessary for drug testing. The PIA can easily be used for cell number determinations in biological and pharmacological studies.

Antimetabolites, Antineoplastic↗
PubMed1995

A randomized clinical trial of intraoral soft splints and palliative treatment for masticatory muscle pain.

Thirty subjects seeking treatment for masticatory muscle pain at a university-based TMJ clinic were randomly assigned to soft-splint, palliative-treatment, and no-treatment groups. After 4 to 11 weeks of treatment, subjects were evaluated for changes from their baseline levels of symptoms, maximum pain-free opening, pain thresholds measured by a pressure algometer, and occlusal contacts. With the use of the multivariate analysis of variance and analysis of covariance, the results suggest that the soft-splint group had statistically significant improvement (P < .01), the palliative-treatment group had improvement that was not statistically significant, and the no-treatment group had a slight aggravation of symptoms. The soft-splint group had fewer occlusal contact changes assessed with shimstock compared to the palliative-treatment and no-treatment groups. The findings of this study suggest that the soft splint is an effective short-term treatment for reducing the signs and symptoms of masticatory muscle pain in patients, and the soft splint does not cause occlusal changes.

Adolescent↗
PubMed1994

The effect of highly diluted agitated thyroxine on the climbing activity of frogs.

We studied the influence of specially prepared highly diluted thyroxine on the spontaneous tendency of juvenile frogs, which were at the end of thyroxine-controlled metamorphosis, to leave the water and climb onto land. The test dilution with a thyroxine concentration beyond Avogadro's value (dilution thyroxine D30) and the reference (dilution water D30) were prepared according to directions from the literature on homeopathy. A few drops of these solutions were added to tap water of basins containing the frogs. The frogs' climbing activities were monitored immediately after adding the solutions. The hypothesis derived from a preliminary study was that there is less climbing activity in frogs treated with dilution thyroxine D30 than in a reference group. This hypothesis was proven. Climbing activity diminished under the influence of dilution thyroxine D30, with statistical significance both in comparison to the effect of the analogously prepared solvent (dilution water D30) as well as in comparison to control observations before the start of treatment. When in a later step of observation the dilution water D30-control group was treated with dilution thyroxine D30, the diminishing effect on activity also occurred.

Animals↗
PubMed1991

Effects of sufentanil on cerebral blood flow, cerebral blood flow velocity, and metabolism in dogs.

The intracranial and systemic hemodynamic effects of sufentanil (20 micrograms/kg) were studied in 10 mongrel dogs. Baseline anesthesia was maintained with 0.7% end-tidal isoflurane and 50% nitrous oxide in oxygen. Catheters were inserted for blood pressure measurement, arterial and sagittal sinus blood sampling, radioactive microsphere injections, and intracranial pressure monitoring. Blood flow velocity was measured continuously in the middle cerebral artery using a transtemporal approach through a cranial window with a pulsed 8 MHz transcranial Doppler system (TCD). Cardiac output was measured using an electromagnetic flow probe on the pulmonary artery. After baseline measurements, sufentanil was injected and data were recorded at 5, 15, and 30 min. In group 1 (n = 5) blood pressure was not controlled, whereas in group 2 (n = 5) blood pressure was maintained at baseline levels with a phenylephrine infusion. Sufentanil decreased blood pressure from 120 +/- 10 mm Hg (mean +/- SEM) to 82 +/- 11 mm Hg in group 1. Cardiac output decreased 40%-50% in both groups. Intracranial pressure did not change. Cerebral blood flow (CBF) and TCD blood flow velocity decreased significantly (35%-40%) with no difference between groups. Relative decreases in CBF and TCD blood flow velocity were closely correlated (r = 0.82). The cerebral hemodynamic changes were associated with a 35%-40% decrease in cerebral oxygen consumption. We conclude that sufentanil decreases CBF in response to decreased metabolic demand without significantly affecting intracranial pressure. Relative changes in CBF can be reproducibly monitored using TCD.

Anesthesia, Inhalation↗