Biomedical subjects

R F Raubertas

Publications and source records attributed to R F Raubertas.

63 records · Page 4Linked to original sources

PubMed1987

Seizures during barbiturate withdrawal: relation to blood level.

We studied 21 patients with complex partial seizures during phenobarbital (PB) or primidone withdrawal. Blood levels were measured daily, and seizure frequency was monitored by nursing staff and EEG-video telemetry. Patients were monitored for one week of baseline and for five weeks after PB tapering was initiated (withdrawal). Most were observed for at least one week after levels were undetectable. When ranked seizure counts were averaged, there was a tendency for seizure rates to be highest as PB levels passed through the range 15 to 20 mg/l, compared with rates at higher or lower PB levels. There was little or no relation between the rate of PB withdrawal, other drug therapy, or initial PB level and the ratio of highest seizure frequency to mean seizure frequency. Patients withdrawing from PB may be most likely to experience an increase in seizure frequency when their PB blood level falls below 20 mg/l.

Humans↗

PubMed1987

The epidemiology of Creutzfeldt-Jakob disease: conclusion of a 15-year investigation in France and review of the world literature.

During the 15-year period 1968-1982, a total of 329 patients dying of Creutzfeldt-Jakob disease (CJD) were identified in continental France. Annual mortality rates stabilized at 0.5 to 0.6 cases per million (1.1 to 1.2 cases per million in Paris). Six percent of cases were familial. Although the frequency of CJD was related to population density, no contacts could be established among the great majority of patients. No association with socioeconomic factors, preceding trauma or surgery (excepting one iatrogenic neurosurgical case), or exposure to animal sources of infection was identified. Evidence from this and other epidemiologic studies suggests that CJD is a minimally contagious disease that may be principally acquired in early life from presymptomatic patients, asymptomatic carriers, or chance contamination by environmental sources. It is possible that CJD could also occur sporadically as a noncontagious disease by a mechanism akin to oncogenes in carcinogenesis.

Adolescent↗

PubMed1983

Emotional states and pain: intraindividual and interindividual measures of association.

The present study investigated the correlation between cancer pain severity and mood states, and addressed methodological issues involved in measuring the association between these groups of variables. Five monthly interviews were administered to 95 cancer pain patients; each interview contained four measures of pain severity and the Profile of Mood States (POMS). The relationships between the two sets of variables were assessed using both interindividual (cross-sectional) and intraindividual (within-subject) methods of correlational analysis. Both types of analyses suggested small but significant positive correlations between the pain measures and negative mood states, and inverse correlations between pain and positive mood. The data also indicated that patients reported high levels of pain but reported little mood disturbance. In addressing methodological issues, the study clarified conceptual and computational differences between the two types of correlational analyses and indicated the appropriate applications of each method.

Affective Symptoms↗

PubMed1982

Maternal serum diamine oxidase in fetal death and low-birth-weight infants.

Serum diamine oxidase was measured at different gestational ages in 681 pregnancies resulting in live births and 102 pregnancies resulting in fetal deaths. Statistical analysis revealed that gestational age-adjusted diamine oxidase levels in the fetal-death group were significantly lower (P less than 0.001) than those in the live-birth group. Moreover, the relative risk associated with a low diamine oxidase level, compared with a normal level, increased from 3.7 at 8 weeks to 16.6 at 12 weeks. Pregnancies resulting in low-birth-weight infants exhibited normal serum diamine oxidase levels. The association between low diamine oxidase and subsequent fetal death is discussed in view of the hypothesis that polyamines and polyamine-degrading enzymes interact to protect the fetoplacental unit from immune rejection.

Amine Oxidase (Copper-Containing)↗

PubMedDate not supplied

Felbamate: a clinical trial for complex partial seizures.

We performed a randomized, double-blind, three-period cross-over study of felbamate (FBM, 2-phenyl-1,3-propanediol dicarbamate: Carter-Wallace 554) in patients with complex partial seizures. Patients continued carbamazepine (CBZ) throughout the study and were observed in the hospital for the entire trial period. The entry criteria required at least six seizures in a 3-week baseline period (and no more than 1 week with a single seizure) with CBZ alone. Thirty subjects were randomized. Two left the study after randomization, 1 owing to seizure exacerbation, and 1 owing to hyponatremia, which may have been related to CBZ therapy. The daily dosage of 50 mg/kg (maximum 3,000 mg) FBM per day was well tolerated by all 28 patients who completed the study. Only mild adverse experience were observed during the trial. FBM reduced CBZ level (p less than 0.0001; 95% confidence interval -28%, -20%). There was no significant difference in seizure frequency between placebo and FBM periods (one-sided p = 0.172), but when a correction was made for the lower CBZ level noted during FBM periods, the data suggested a strong antiseizure effect of FBM.

Adult↗

PubMedDate not supplied

The effects of benzoate and fluoride on dental caries in intact and desalivated rats.

The decline in prevalence of dental caries in some segments of the population has been attributed mainly to extensive exposure to fluoride. Over the past decades, the use of fluoridated products has increased. During the same period, the consumption of food preservatives such as benzoates and sorbates has also increased substantially. Benzoates, in vitro, possess antibacterial properties similar to those of fluoride and in combination with fluoride could affect caries development. In the present study we explored the effects of sodium benzoate and fluoride in combination and alone on dental caries in our animal model. The results showed a combination of benzoate and fluoride reduced caries activity more effectively in rodents fed a cariogenic diet ad libitum than fluoride alone (p = 0.038).

Animals↗

PubMedDate not supplied

ROC curves for classification trees.

A common problem in medical diagnosis is to combine information from several tests or patient characteristics into a decision rule to distinguish diseased from healthy patients. Among the statistical procedures proposed to solve this problem, recursive partitioning is appealing for the easily-used and intuitive nature of the rules it produces. The rules have the form of classification trees, in which each node of the tree represents a simple question about one of the predictor variables, and the branch taken depends on the answer. The authors consider the role of misclassification costs in developing classification trees. By varying the ratio of costs assigned to false negatives and false positives, a series of classification trees are generated, each optimal for some range of cost ratios, and each with a different sensitivity and specificity. The set of sensitivity-specificity combinations define a curve that can be used like an ROC curve.

Child, Preschool↗

PubMedDate not supplied

Cryopreservation of human semen. Comparison of cryopreservatives, sources of variability, and prediction of post-thaw survival.

Human semen was cryopreserved using Human Sperm Preservation Medium, TEST-Yolk buffer, or glycerol alone. Sperm characteristics for each specimen were measured before and after freezing to determine which cryopreservative resulted in better cryosurvival and recovery of motile sperm. Sperm frozen in Human Sperm Preservation Medium had a significantly better recovery of all semen parameters (motility, velocity, and recovery) than either TEST-Yolk or glycerol alone. Statistical analyses also were done to examine the variability between and within donor semen specimens. Differences between donors, between specimens, and measurements within donors all contributed to variability of sperm characteristics. Specimen-to-specimen variability for a given donor represented 12% to 47% of the total variability, whereas processing and measurement variability represented 12% to 41%. Donors also varied in the ability of their sperm to tolerate freezing. There was a relationship between motile count after dilution with cryopreservative and post-thaw motile count. This relationship allows the prediction of poor-thaw survival before freezing a specimen.

Cell Survival↗

PubMedDate not supplied

A performance-based incentive program for influenza immunization in the elderly.

Our objective was to implement and evaluate performance-based reimbursement for influenza immunization of the elderly in physician offices. We performed a community-based quasi-experiment with historic and concurrent comparisons, using primary care physician offices in Monroe County, New York. Participants in the intervention group included 53 primary care physicians admitting to one hospital, and the comparison group included 82 primary care physicians admitting to other hospitals. All physicians participated in a Medicare-sponsored demonstration to increase influenza immunization rates, and, during the 1990-1991 immunization season, used a target-based poster to track immunization rates. Physicians in the intervention group were enrolled in a performance-based financial incentive program that rewarded immunization rates above 70%. A survey concerning influenza immunization practices and opinions was sent to all physicians. The average physician-specific immunization rate in the incentive group was 73.1% versus 55.7% in the comparison practices (P < .001). Eligibility for incentives, practice size, sex of physician, medical specialty, reminder postcards, and practice populations including medically indigent patients were associated with immunization level. Controlling for the above variables, we completed a regression analysis showing that eligibility for the incentive was still significant (P = .003). The survey responses were not predictive of performance or significantly different between the two groups, except for the negative influence of sending postcards. This study in a community setting suggests that linking reimbursement to performance may be a successful strategy to increase influenza immunization levels for the elderly.

Aged↗