PubMed Health⌕ Search

Biomedical subjects

S Gabriel

Publications and source records attributed to S Gabriel.

At least 37 records · Page 2Linked to original sources
PubMed2000

Isolated acute knee injuries in the general population.

OBJECTIVE: Knee injuries are common in the general population, yet most studies have concentrated on special populations. The purpose of this study was to describe the types of injuries, injury events, age, and sex distributions in a community population. METHODS: The medical records of all residents of Olmsted County, Minnesota, 17 years of age or older who had a first visit for an isolated acute knee (acute was defined as occurring within 60 days of the physician visit) injury between January 1, 1993, and January 1, 1996, were abstracted. RESULTS: A total of 664 patients (4/1,000 community adults, 46% women and 54% men) presented to a physician for evaluation and treatment of an isolated acute knee injury. Injured men were on average younger than women and more likely to have an injury during a sports activity, whereas women's injuries were more likely to be the result of non-sports-related falls. Knee sprain or strain was the most common final diagnosis (36%). Approximately half (49%) of the patients had a single visit. The likelihood of orthopedic surgeon's care (37% overall) increased with injury severity and age of the patient. Overall, 12% of subjects had surgical treatment recommended. CONCLUSION: Knee injuries are common, often result in a single visit, seldom receive surgical intervention, and the majority are cared for entirely by generalist physicians.

Accidental Falls↗
PubMed2000

Sadness and susceptibility to judgmental bias: the case of anchoring.

In a wide range of empirical paradigms, sadness has been associated with more extensive and detail-oriented thinking than happiness, resulting in reductions in judgmental bias that arise from reliance on stereotypes and other simple decision heuristics. It was hypothesized that anchoring would constitute a significant exception to this general pattern. Recent research on anchoring indicates that an active thought process underlies the emergence of this bias. If sad people are likely to think more actively about the judgmental anchor than their neutral-mood counterparts, their subsequent judgments should be more likely to be assimilated toward this reference point. This prediction was confirmed in two experiments demonstrating that sad people are indeed more susceptible to anchoring bias than are people in a neutral mood. Moreover, this effect generalized over judgments in positive, neutral, and negative content domains.

Adult↗
PubMed2000

Alterations of glial cell function in temporal lobe epilepsy.

PURPOSE: Comparison of extracellular K+ regulation in sclerotic and nonsclerotic epileptic hippocampus. METHODS: Measurements of K+ signals with double-barreled K+-selective reference microelectrodes in area CAI of slices from human and rat hippocampus, induction of increases in extracellular potassium concentration by repetitive alvear stimulation or iontophoresis. and block of inward-rectifying and background K+ channels in astrocytes by barium. RESULTS: In the CA1 pyramidal layer from normal rat hippocampus, barium augmented extracellular K+ accumulation induced by iontophoresis or antidromic stimulation in a dose-dependent manner. Similarly, barium augmented stimulus-induced K+ signals from nonsclerotic hippocampi (human mesial temporal lobe epilepsy). In contrast, barium failed to do so in sclerotic hippocampi (human mesial temporal lobe epilepsy, rat pilocarpine model). CONCLUSIONS: Our findings suggest that in areas of reduced neuronal density (hippocampal sclerosis), glial cells adapt to permit rather large increases in extracellular potassium accumulation. Such increases might be involved in the transmission of activity through the sclerotic area.

Animals↗
PubMed2000

Alterations of neuronal connectivity in area CA1 of hippocampal slices from temporal lobe epilepsy patients and from pilocarpine-treated epileptic rats.

PURPOSE: Neuronal network reorganization might be involved in epileptogenesis in human and rat limbic epilepsy. Apart from aberrant mossy fiber sprouting, a more widespread fiber rearrangement in the hippocampal formation might occur. Therefore, we studied sprouting in area CA1 because this region is most affected in human temporal lobe epilepsy. METHODS: In slices from hippocampi of patients operated on for temporal lobe epilepsy (n = 134), from pilocarpine-treated rats (n = 74), and from control rats (n = 15), viable neurons were labeled with fluorescent dextran amines. RESULTS: In human hippocampi as well as in pilocarpine-treated rats, the degree of nerve cell loss varied. In 67 of 134 slices from human specimens with distinct Ammon's horn sclerosis and in 23 of 74 slices from pilocarpine-treated rats, a severe shrunken area CA1 presented with a similar picture: few damaged neurons were labeled, and aberrant fiber connections were not visible. This was in contrast to human resected hippocampi and hippocampi from pilocarpine-treated rats with no or moderate loss of neurons. In these cases, pyramidal cells remote from the injection site were labeled (human tissue, n = 59 of 134; pilocarpine-treated rats, n = 39 of 74). In human resected hippocampi without obvious pathology and in control animals, no pyramidal neurons were labeled apart from the injection site. CONCLUSIONS: Axon collaterals of CA1 pyramidal cells are increased in human temporal lobe epilepsy and in pilocarpine-treated rats. Adjacent CA1 pyramidal cells project via aberrant collaterals to the stratum pyramidale and the stratum radiatum of area CA1. This network reorganization can contribute to hyperexcitability via increased backward excitation.

Animals↗
PubMed1999

Acute cell damage after low Mg2+-induced epileptiform activity in organotypic hippocampal slice cultures.

Upon perfusion with Mg2+-free artificial cerebrospinal fluid (ACSF) organotypic hippocampal slice cultures develop seizure-like events and tonic recurrent discharges in which areas CA3 and CA1 and, in contrast to acute slices, also the dentate gyrus (DG) participate. Using the fluorescent dye propidium iodide (PI) we show that sustained epileptic activity causes cell death in the DG and pyramidal cell layer particularly evident in the granule cell layer of the DG. This correlates with the decrease of the electrophysiological responses to hilar stimulation. Interestingly, perfusion with carbogenated serum-free ACSF also induces some cell death which is, however, mild compared with low magnesium treated slice cultures.

Animals↗
PubMed1999

Cost-effectiveness of ursodeoxycholic acid therapy in primary biliary cirrhosis.

Ursodeoxycholic acid (UDCA) is a safe and effective treatment for patients with primary biliary cirrhosis (PBC), but the cost of this drug has raised concerns regarding cost-effectiveness. The aim of our study was to determine the cost-effectiveness of UDCA in PBC. We compared the costs and outcomes of managing PBC patients with and without UDCA. From two previously published trials, the effectiveness of UDCA was determined by comparing the annual reduction in the development of ascites, varices, variceal bleeding, encephalopathy, liver transplantation, and death between the treatment groups. Average annual costs for each of these events were estimated based on literature and institutional data. Approximately twice as many major events occurred in the placebo group compared with the UDCA group. The relative risk (RR) of liver transplantation (1.95; 95% CI: 1.14-3.68) and development of esophageal varices (3. 11; 95% CI: 1.57-10.65) were significantly higher in the placebo group compared with the UDCA group. There were no significant increases in the RR of ascites, variceal bleeding, encephalopathy, or death between the two groups. Based on the estimated annual cost of managing these events and the annual costs of UDCA ($2,500), there was an annual cost savings per patient of $1,372. Compared with the placebo group, patients receiving UDCA had a lower incidence of major complications and lower medical care costs.

Canada↗
PubMed1999

[Marchiafava-Bignami syndrome. Extrapontine myelinolysis in chronic alcoholism].

Until now, the pathogenesis of Marchiafava-Bignami disease, an extrapontine myelinolysis, is unknown. Accept an abuse of alcohol for many years additional metabolic and vascular disturbances are supposed. The early performance of magnetic resonance imaging in patients with a sudden encephalopathy and history of alcoholism is essential for an assessment of the diagnosis. The bilateral lack of transcallosal inhibition--a parameter for the integrity of the transcallosal connections between motor cortices--is the consequence of the axonal degeneration of transcallosal fibers. Clinical and neuroradiological features of three patients with extrapontine myelinolysis are reported and possible etiologies of the complex disease are discussed. In two cases a severe alcohol abuse was present with the typical picture of the Marchiafava-Bignami disease. In a third patient an intoxication with methanol was present with a similar clinical picture. Although severe neurological disturbances were initially apparent in the patients, during the follow-up there was a significant amelioration of the clinical course under a high-dose vitamin B supplementation.

Adult↗
PubMed1999

Are there "his" and "hers" types of interdependence? The implications of gender differences in collective versus relational interdependence for affect, behavior, and cognition.

In a recent review, S. E. Cross and L. Madson (1997) forwarded that many gender differences in social experience and behavior may be better understood through consideration of gender differences in independence and interdependence. In the current studies an expansion of the model to include both relational and collective aspects of interdependence was investigated (see R. F. Baumeister & K. L. Sommer, 1997). On the basis of the literature regarding gender differences in affect, behavior, and cognition, it was hypothesized that women would focus more on the relational aspects of interdependence, whereas men would focus more on the collective aspects of interdependence. Five studies in which gender differences in self-construals, emotional experience, selective memory, and behavioral intentions were examined supported the expansion of the model to include both relational and collective aspects of interdependence.

Adult↗
PubMed1998

Epileptiform activity and changes in field potential responses induced by low [Mg2+]0 in a genetic rat model of absence epilepsy.

The genetic absence epilepsy rats of Strasbourg (GAERS) display alterations in cortical synaptic transmission possibly facilitating the generation of ictaform activity and the late development into convulsive epilepsy. We studied low Mg2+-induced epileptiform activities and their long term effects on field potentials (fp) evoked by paired pulse stimulation in hippocampal area CA1 (CA1), medial entorhinal cortex (EC) and frontal cortex (FC) in in-vitro-slice preparations from GAERS and control (NE) adult rats (6 months). Omitting Mg2+-ions from artificial cerebrospinal fluid (ACSF) caused recurrent short discharges (in CA1) and seizure-like events (in EC) in both GAERS and NE rats. Latency to onset of activity as well as discharge pattern, frequency and amplitude of such events did not differ between the two strains, neither in CA1 nor in EC. In the FC, however, epileptiform events occurred in NE rats, but not in GAERS. Field potentials in normal ACSF were similar in both strains in CA1 and FC, while they were smaller in the EC of GAERS. Low [Mg2+]0 caused long-term changes of fp only in area CA1 where the population spikes were depressed in GAERS and increased in NE rats. We concluded that susceptibility to low [Mg2+]0-induced epileptic activity in EC and hippocampal area CA1 is not higher in GAERS than in NE adult rats. However, some properties like synaptic coupling in EC and long-term changes in synaptic efficacy induced by epileptiform activity in CA1 differ from that in NE rats. Whether the particularities in GAERS may be related to kindling by absence epileptic activities will be studied in further experiments.

Animals↗
PubMed1998

Effects of barium on stimulus-induced rises in [K+]o in juvenile rat hippocampal area CA1.

Immature glia may not be able to buffer K+ ions released during neuronal activity. Therefore, we investigated entorhinal-hippocampal slices of juvenile rats (ages P15-18 and P22-26) using a perfusion medium containing 2 mM BaCl2 in order to block glial inward rectifying and leak potassium channels. In contrast to adult animals, rises in [K+]o in slices from juvenile animals elicited by repetitive alvear stimulation were not augmented by Ba2+. Ba2+ effects on fast field potentials, slow field potentials and the applied current sink source distribution were roughly similar as in adult rats. We conclude that the capacity to buffer large quantities of K+ ions by mechanisms involving Ba2+-sensitive K+ channels has not yet developed in juveniles.

Animals↗
PubMed1998

Hostility is associated with a heightened prolactin response to meta-chlorophenylpiperazine in abstinent cocaine addicts.

The prolactin (PRL) response to the administration of serotonin (5HT) agonists is an index of central nervous system 5HT activity. This index is blunted in association with hostile aggression in personality and depressive disorder patients without substance abuse. We tested whether the PRL response to the oral administration of the partial 5HT agonist meta-chlorophenylpiperazine (MCPP), 0.35 mg/kg, was associated with a measure of trait hostility, the Buss Durkee Hostility Inventory (BDHI), in cocaine addicts who were completing a 3-week detoxification and rehabilitation program. We also tested whether the cocaine addicts differed from healthy volunteers on their PRL, cortisol (CORT) or temperature responses to MCPP. The PRL response to MCPP was positively associated with the total score on the BDHI. There were, however, no differences in the neuroendocrine or temperature responses to MCPP between the cocaine-dependent group and the healthy volunteers once age effects were controlled for.

Adult↗
PubMed1998

Effects of barium on stimulus-induced changes in [K+]o and field potentials in dentate gyrus and area CA1 of human epileptic hippocampus.

The effects of barium on stimulus-induced rises in [K+]o were studied in the dentate gyrus (DG) and area CA1 of human hippocampal slices. Rises in [K+]o elicited by repetitive stimulation of the hilus, stratum moleculare, alveus, or stratum radiatum were dependent on stimulus intensity and frequency. Barium augmented rises in [K+]o in the DG by about 120% but failed to do so in area CA1. In both DG and area CA1 barium had no effects on population spikes whereas stimulus-induced slow field potentials were reduced. Since barium interferes with K+ uptake and redistribution by blocking leak conductances and inwardly-rectifying currents in astrocytes, our findings suggest that glial cells in the sclerotic hippocampal area CA1 may contribute less to K+ regulation.

Adult↗
PubMed1998

Effects of barium on stimulus induced changes in extracellular potassium concentration in area CA1 of hippocampal slices from normal and pilocarpine-treated epileptic rats.

Laminar profiles of rises in [K+]o and slow field potentials induced by alvear stimulation were recorded in area CA1 of hippocampal slices from control and pilocarpine-treated rats in absence and presence of Ba2+. In control animals, Ba2+ augmented rises in [K+]o in stratum pyramidale (SP) as well as in stratum radiatum (SR). In pilocarpine-treated animals an augmentation of rises in [K+]o was restricted to SP and its immediate vicinity. Moreover, the effect of Ba2+ in SP was small or missing in eight out of 15 slices of pilocarpine-treated animals. In these slices laminar profiles of rises in [K+]o were not affected by Ba2+. It is suggested that spatial K+-buffering is reduced in area CA1 of epileptic animals.

Animals↗
PubMed1998

Cost-effectiveness of ultrasound-guided liver biopsy.

The risk of a major complication from "blind" percutaneous liver biopsy is reported to be in the range of 0.24% to 3.8%. In a recent randomized trial, patients whose liver biopsies were performed with ultrasonography had a significant reduction in complications requiring hospitalization compared with patients without ultrasound-guided biopsies (0.5% vs. 2.2%, P < .05). Despite this, routine use of ultrasonography for liver biopsies has not been implemented because of controversies with respect to cost-effectiveness. The aim of our study was to analyze the relative cost-effectiveness of performing ultrasound-guided liver biopsies using decision analysis. A decision tree was constructed to compare a strategy of liver biopsy using ultrasonography with a strategy without ultrasonography. The major outcomes included were minor complications such as pain requiring analgesics and major complications, which require hospitalization. Costs included were direct medical costs from the payer's perspective. In our baseline model, the cost from complications per patient with and without ultrasonography was $62 and $129, respectively. The marginal effectiveness expressed as the number of major complications avoided was 1.2/100 liver biopsies. The incremental cost to avoid one major complication was $2,731. The model was most sensitive to the frequency of major complications and the additional cost of ultrasonography. Our decision analysis model suggests that ultrasound-guided liver biopsy is cost-effective. Future studies assessing the efficacy of image-guided liver biopsies should be conducted.

Biopsy, Needle↗
PubMed1998

Serotonin function and risk for alcoholism in boys with attention-deficit hyperactivity disorder.

Data in animals and adults indicate that central serotonergic (5-HT) function may be involved in the development of alcohol abuse. Despite this, studies exploring this mechanism in individuals at risk for alcoholism are scant. This study used a fenfluramine (FEN) challenge procedure to investigate the relationship between risk for alcoholism and 5-HT function in 7- to 11-year-old boys with attention-deficit hyperactivity disorder (ADHD). The prolactin (PRL) and cortisol (CORT) responses to FEN were examined in 10 sons of alcoholic fathers (FA+) and 30 sons of nonalcoholic fathers (FA-). The FA+ group had a significantly greater CORT, but not PRL, response to FEN relative to the FA- group. The discrepancy between the CORT and PRL responses may be due to the different mechanisms that underlie their 5-HT stimulated release. This suggests that, among ADHD boys, those at familial risk for alcohol abuse may differ from those who are not at risk in 5-HT function.

Alcoholism↗