Showing papers by "Virginia Commonwealth University published in 1993"

The role of secondary brain injury in determining outcome from severe head injury.

Abstract: As triage and resuscitation protocols evolve, it is critical to determine the major extracranial variables influencing outcome in the setting of severe head injury. We prospectively studied the outcome from severe head injury (GCS score < or = 8) in 717 cases in the Traumatic Coma Data Bank. We investigated the impact on outcome of hypotension (SBP < 90 mm Hg) and hypoxia (Pao2 < or = 60 mm Hg or apnea or cyanosis in the field) as secondary brain insults, occurring from injury through resuscitation. Hypoxia and hypotension were independently associated with significant increases in morbidity and mortality from severe head injury. Hypotension was profoundly detrimental, occurring in 34.6% of these patients and associated with a 150% increase in mortality. The increased morbidity and mortality related to severe trauma to an extracranial organ system appeared primarily attributable to associated hypotension. Improvements in trauma care delivery over the past decade have not markedly altered the adverse influence of hypotension. Hypoxia and hypotension are common and detrimental secondary brain insults. Hypotension, particularly, is a major determinant of outcome from severe head injury. Resuscitation protocols for brain injured patients should assiduously avoid hypovolemic shock on an absolute basis.

Smoking and Major Depression: A Causal Analysis

Abstract: • Among 1566 personally evaluated female twins from a population-based register, average lifetime daily cigarette consumption was strongly related to lifetime prevalence and to prospectively assessed 1-year prevalence of major depression (MD). Using the cotwin control method, we evaluated whether the association between smoking and lifetime MD was causal or noncausal. While the relative risk (95% confidence interval) for ever smoking given a lifetime history of MD was 1.48 (1.30 to 1.65) in the entire sample, it was 1.18 (0.88 to 1.47) and 0.98 (0.71 to 1.26), respectively, in dizygotic and monozygotic twin pairs discordant for a history of MD. The relative risk for a history of MD given ever smoking was 1.60 (1.39 to 1.83) in the entire sample, while in dizygotic and monozygotic twins discordant for smoking, it was 1.29 (0.87 to 1.74) and 0.96 (0.59 to 1.42), respectively. Controlling for personal smoking history, family history of smoking predicted risk for MD; controlling for the personal history of MD, family history of MD predicted smoking. The best-fitting bivariate twin model suggested that the relationship between lifetime smoking and lifetime MD resulted solely from genes that predispose to both conditions. These results suggest that the association between smoking and MD in women is not a causal one but arises largely from familial factors, which are probably genetic, that predispose to both smoking and MD.

A Phase II Study of Moderate Hypothermia in Severe Brain Injury

Abstract: Forty-six patients with severe nonpenetrating brain injury [Glasgow Coma Scale (GCS) 4–7] were randomized to standard management at 37°C (n = 22) and to standard management with systemic hypothermia to 32 to 33°C (n = 24). The two groups were balanced in terms of age (Wilcoxon's rank sum test, p > 0.95), randomizing GCS (chi-square test, p = 0.54), and primary diagnosis. Cooling was begun within 6 h of injury by use of cooling blankets. Metocurine and morphine were given hourly during induction and maintenance of hypothermia. Rewarming was at a rate of 1°C per 4 h beginning 48 h after intravascular temperature had reached 33°C. Muscle relaxants and sedation were continued until core temperature reached 35°C. There were no cardiac or coagulopathy-related complications. Seizure incidence was lower in the hypothermia group (Fisher's exact text, p = 0.019). Sepsis was seen more commonly in the hypthermia group, but difference was not statistically significant (chi-square test). Mean Glasgow Outcome S...

Molecular characterization of an operon required for pertussis toxin secretion

Abstract: Mutants of Bordetella pertussis which are defective in secretion of pertussis toxin were isolated and characterized. The region of the B. pertussis chromosome identified by mutagenesis as playing a role in transport of pertussis toxin was sequenced. Analysis of this region revealed eight open reading frames, seven of which predict a protein exhibiting homology with one of the VirB proteins of Agrobacterium tumefaciens, which are involved in the transport of the T-DNA molecule across bacterial and plant membranes. Thus a set of accessory proteins are most likely involved in the secretion of pertussis toxin, and these proteins appear to be members of a family of proteins involved in the secretion of macromolecules from bacteria.

A Twin Study of Recent Life Events and Difficulties

Abstract: Objectives: To examine the role of genetic and familialenvironmental factors in the origin of stressful life events. Design: Self-report questionnaires describing stressful life events in the last year. Participants: Both members of 2315 twin pairs ascertained from the population-based Virginia Twin Registry. Results: Life events were modestly but significantly correlated in twin pairs, and correlations in monozygotic (MZ) twins consistently exceeded those in dizygotic (DZ) twins. For total life events, the best-fitting twin model indicated that familial-environmental and genetic factors each accounted for around 20% of the total variance. Individual life events could be best divided into "network events" (directly affecting individuals in the respondent's socialnetwork) where twin resemblance was due solely to the familial environment, and "personal" events (directly affecting the response) where most twin resemblance was the result of genetic factors. Conclusions: While neither genes nor familial environment is likely to directly produce life events, personal and social factors that predispose to life events are substantially influenced by an individual's genetic and family background. These results, which suggest that stressful life events reflect more than random influences, may have important implications for our understanding of the relationship between stressful life events and psychopathology.

Complications of transjugular intrahepatic portosystemic shunt: a comprehensive review.

Abstract: It is generally accepted that the transjugular intrahepatic portosystemic shunt (TIPS) procedure has lower morbidity and mortality rates than those of surgical shunting. Nevertheless, complications occur. The authors have reviewed their experience and that of other institutions in compiling an extensive list of complications. Complications are categorized according to those related to transhepatic needle puncture, transvenous access to the portal vein, portal venous cannulation, the stent, the puncture site, portosystemic shunting, and contrast material. Excluding hepatic encephalopathy and delayed stenosis or occlusion of the shunt, an overall complication rate of less than 10% can be expected for TIPS. The prevalence of aggravated or new cases of encephalopathy is 5%-35%, and over the long term, up to 75% of shunts may undergo stenosis or occlusion. The direct procedural mortality rate is less than 2%, and the 30-day mortality rate ranges from 4% to 45%, depending on several factors. The role to which TIPS is relegated will be influenced by the long-term success rate in the prevention of recurrent variceal hemorrhage.

Giant magnetic moments in 4d clusters.

Abstract: Electronic structure of 13-atom clusters of 4d nonmagnetic solids Pd, Rh, and Ru has been studied using a linear combination of atomic orbitals molecular-orbital approach within the density functional formalism. ${\mathrm{Pd}}_{13}$, ${\mathrm{Rh}}_{13}$, and ${\mathrm{Ru}}_{13}$ are all found to have nonzero magnetic moments. Unexpectedly, the ground state of ${\mathrm{Rh}}_{13}$ is found to have 21 unpaired electrons and thus a magnetic moment of 21${\mathrm{\ensuremath{\mu}}}_{\mathit{B}}$. These 4d-element magnetic moments are a result of the reduced dimensionality and the enhanced electronic degeneracy due to the symmetry of the cluster. The effect of impurities on the moments is examined through calculations on ${\mathrm{FePd}}_{12}$, ${\mathrm{FeRh}}_{12}$, ${\mathrm{RhPd}}_{12}$, and ${\mathrm{RuPd}}_{12}$ clusters.

Life Development Intervention for Athletes Life Skills through Sports

Abstract: The purpose of this article is to describe sport psychology and a model for its practice that is consistent with the training of counseling psychologists as teachers of life skills. Following an examination of the role that sport plays in our society and its importance for the development of identity and personal competence, what is meant by sport psychology and why it is a relevant area of study for counseling psychologists will be specified. A psychoeducational model for the practice of sport psychology, life development intervention (LDI), will be delineated and some examples of sport psychology consistent with the LDI model proposed. Using LDI as a base, dilemmas that counseling psychologists face when doing sport psychology will be considered Finally, some of the training issues for counseling psychologists doing sport psychology will be presented.

Development of human mast cells from umbilical cord blood cells by recombinant human and murine c-kit ligand.

Abstract: Both human and mouse c-kit ligand induced differentiation of human mast cells in a long-term culture of the mononuclear cells of umbilical cord blood. Growth factor activity for human mast cells present in conditioned medium of BALB/3T3 fibroblasts was due to mouse c-kit ligand. Recombinant c-kit ligand induced differentiation and proliferation of mast cell progenitors in early stages of culture. However, apparent selective growth of mast cells by c-kit ligand in cord blood cell cultures is mainly due to the effect of the cytokine to selectively maintain survival of immature mast cells. Electron microscopic analysis indicated that human mast cells developed by c-kit ligand were similar to human mast cells in the lung and gut mucosa, while those developed in coculture of cord blood cells with Swiss albino/3T3 fibroblasts were similar to skin mast cells. This conclusion was supported by the fact that the majority of mast cells developed by c-kit ligand contained only tryptase in their granules, whereas those developed in the cocultures contained both tryptase and chymase. It was also found that mast cells developed by c-kit ligand were immature even after culture for 14 weeks. Nevertheless, these cells express Fc epsilon RI, and could be sensitized with human IgE for anti-IgE-induced release of histamine, prostaglandin D2, and leukotriene C4.

Heritable Factors Influence Sexual Orientation in Women

Abstract: • Homosexual female probands with monozygotic cotwins, dizygotic cotwins, or adoptive sisters were recruited using homophile publications. Sexual orientation of relatives was assessed either by asking relatives directly, or, when this was impossible, by asking the probands. Of the relatives whose sexual orientation could be confidently rated, 34 (48%) of 71 monozygotic cotwins, six (16%) of 37 dizygotic cotwins, and two (6%) of 35 adoptive sisters were homosexual. Probands also reported 10(14%) nontwin biologic sisters to be homosexual, although those sisters were not contacted to confirm their orientations. Heritabilities were significant using a wide range of assumptions about both the base rate of homosexuality in the population and ascertainment bias. The likelihood that a monozygotic cotwin would also be homosexual was unrelated to measured characteristics of the proband such as self-reported history of childhood gender nonconformity. Concordant monozygotic twins reported similar levels of childhood gender nonconformity.

Improving the outcome of severe head injury with the oxygen radical scavenger polyethylene glycol-conjugated superoxide dismutase: a phase II trial.

Abstract: Formation of the oxygen radical superoxide anion is one of the final events of several metabolic pathways in the cascade that leads to delayed neuronal death after traumatic or ischemic brain injury. In the laboratory, scavenging of the superoxide anion with native superoxide dismutase (SOD) or polyethylene glycol (PEG)-conjugated SOD (PEG-SOD) has been shown to be beneficial in several types of traumatic and ischemic injury. Accordingly, PEG-SOD was utilized in a randomized controlled Phase II trial to evaluate its safety and efficacy in severely head-injured patients with a Glasgow Coma Scale score of 8 or less. At two institutions, 104 patients were randomly assigned to receive either placebo or PEG-SOD (2000, 5000, or 10,000 U/kg) intravenously as a bolus, an average of 4 hours after injury. Prognostic factors were evenly distributed in the four groups, except for mean age which was significantly higher in the group receiving 10,000 U/kg than in the placebo group (mean age 34 years vs. 25 years). No complications attributed to the study medication were noted. The average intracranial pressure (ICP) was similar in the four groups, but the percentage of time during which ICP was above 20 mm Hg was less in the groups receiving 5000 or 10,000 U/kg of PEG-SOD. Patients in the group receiving 10,000 U/kg also required less mannitol for ICP control than the placebo group. Outcome was assessed using the Glasgow Outcome Scale at 3 and 6 months postinjury in 91 and 93 patients, respectively, by blinded observers not involved in the clinical management of the patients. At 3 months, 44% of patients in the placebo group were vegetative or had died, while only 20% of patients in the group receiving 10,000 U/kg of PEG-SOD were in these outcome categories (p < 0.03, multiple logistic regression test); at 6 months, these figures were 36% and 21%, respectively (p = 0.04). Differences in outcome between the placebo group and either of the other two dosage groups were not statistically significant. It is concluded that PEG-SOD was generally well tolerated and appears promising in improving outcome after severe head injury. A larger, multicenter, Phase III trial, using a higher dose (20,000 U/kg) compared to placebo and to 10,000 U/kg of PEG-SOD is planned.

Fragmentation of protonated peptides: surface-induced dissociation in conjunction with a quantum mechanical approach.

Abstract: This paper describes the results of a systematic investigation designed to assess the utility of surface-induced dissociation in the structural analysis of small peptides (500-1800u). A number of different peptides, ranging in mass and amino acid sequence, are fragmented by collision with a surface in a tandem mass spectrometer and the spectra are compared with data obtained by gas-phase collisional activation. The surface-induced dissociation spectra provide ample sequence information for the peptides. Side-chain cleavage ions of type w, which are generally detected upon kiloelectronvolt collisions with gaseous targets but not upon electronvolt collisions with gaseous targets, are detected in the ion-surface collision experiments. A theoretical approach based on MNDO bond order calculations is suggested for the description of peptide fragmentation. This model, supplemented by ab initio calculations, serves as a complement to the experimental work described in the paper and explains (i) the easy cleavage of the amide bond, (ii) charge-remote backbone and side-chain cleavages, and (iii) the influence of intramolecular H-bonding.

The use of antibodies targeted against the neurofilament subunits for the detection of diffuse axonal injury in humans.

Abstract: Axonal injury is a common feature of human traumatic brain injury. Typically, damaged axons cannot be recognized unless a patient survives the injury by at least 10-12 hours (h). Limitations associated with the use of the traditional silver methods have been linked with this inability to recognize early posttraumatic reactive axonal change. Recently, we reported that antibodies targeting the neurofilament subunits proved useful in recognizing early traumatically induced axonal change in traumatically brain-injured animals. Accordingly, in the present communication, we employed antibodies to detect at the light microscopic level the 68 kD Nf-L and 170-200 kD Nf-H neurofilament subunits in head-injured patients who survived the traumatic event for periods ranging from 6 h to 59 days. Antibodies targeting all of the above-described subunits revealed a progression of reactive axonal change. Antibodies to the 68 kD subunit proved most useful, as they were not complicated by concomitant immunoreactivity in surrounding nuclei and/or dendritic and somatic elements. These immunocytochemical strategies revealed, at 6 h postinjury, focally swollen axons which appeared intact. By 12 h, this focal swelling had progressed to disconnection, with the immunoreactive swelling undergoing further expansion over 1 week postinjury. These findings demonstrate the utility of the previously described immunocytochemical strategies for detecting reactive axonal change in brain-injured humans, particularly in the early posttraumatic course. More importantly, these methods also demonstrate in humans that reactive axonal change is not necessarily caused by traumatically induced tearing.

Analysis of gender effects on pain perception and symptom presentation in temporomandibular pain

Abstract: Based on clinical populations, chronic orofacial pain of temporomandibular disorders (TMD) occurs more frequently (range: 2:1 to 9:1) in women than men. The reasons for this difference are not clear. The present study evaluated symptom presentation, sensitivity to pain, personality, and illness behavior in 2 samples of patients suffering with orofacial pain. Also, pain responses were studied in pain-free volunteers, controlling for experimenter-gender effects. The results showed few gender differences based on ratings of chronic or experimental pain, pain-related illness behavior, and personality. The higher ratio of women versus men seeking TMD care is consistent with greater health awareness or interest in symptoms by women than by men.

Experimental Economics: Methods, Problems, and Promise

Abstract: The purpose of this paper is to discuss the grow­ ing importance of experimentation in economic analysis. We present a variety of economic is­ sues that have been explored with laboratory techniques. We also address some common ob­ jections to experimentati on, as well as some of the principal lessons that have been learned.

A national study of the efficiency of hospitals in urban markets.

Abstract: Using a sample of 3,000 urban hospitals, this article examines the contributions of selected hospital characteristics to variations in hospital technical efficiencies, while it accounts for multiple products and inputs, and controls for local environmental variations. Four hospital characteristics are examined: hospital size, membership in a multihospital system, ownership, and payer mix (managed care contracts, percent Medicare, and percent Medicaid). Ownership and percent Medicare are consistently found to be related significantly to hospital efficiency. Within the ownership variable, government hospitals tend to be more efficient and for-profit hospitals less efficient than other hospitals. Higher percentages of Medicare payment are negatively related to efficiency. While not consistently significant across all five of the MSA size categories in which the analyses are conducted, possession of managed care contracts, membership in a multihospital system, and size all are consistently related positively to hospital technical efficiency. These variables are also all significant when the hospitals are examined in a combined analysis. Percent Medicaid was not significant in any of the analyses. Implications for policy and the need for methodological work are discussed.

Peeling Back the Onion: Personality, Problem Solving, and Career Decision-Making Style Correlates of Career Indecision:

Abstract: A model to predict affective and informational antecedents of career indecision was proposed. The model attempted to explicate paths between personality dispositions, appraisal of problem-solving skills, career decision-making styles, and antecedents of career indecision. Both personality and coping constructs were posited to examine the relative contribution of dispositional and perceived skill variables. Using a college student sample, results from a path analysis indicated that the disposition of neuroticism was a powerful predictor of perceived problem-solving skills, a dependent decision- making style, and both affective and informational antecedents of career indecision. The predicted effects of the coping constructs were of a much smaller magnitude. Directions for future research are discussed and several suggestions for career counseling assessment and intervention selection are made.

Precision, accuracy, and data acceptance criteria in biopharmaceutical analysis

Abstract: Accuracy and precision are the most important criteria in the assessment of an analytical method, and monitoring quality control during sample analysis is essential to ensure the validity of reported results. Various approaches to testing accuracy, precision, and quality control were applied to 10 analytes from seven chromatographic bioanalytical methods. These methods include fixed interval bias and significance testing for accuracy; fixed interval percentage relative standard deviation (%RSD) and analysis of variance (ANOVA) approaches for precision; ±20% fixed range, 99% confidence interval, multiple rules, and range chart for individuals approaches for quality control acceptance criteria. Quality control approaches were also applied to the entire run and to a bracketed approach whereby results are considered valid only if bracketed by acceptable quality control. Accuracy and precision were assessed for six runs of each analyte at three concentrations established to represent the calibration range of the analytical method. Quality control acceptance criteria were evaluated using all data sets from each of the analytical methods collected during the course of running various numbers of real samples. The data suggest that the fixed interval bias criteria for accuracy was a more liberal method of accuracy assessment because three of the seven methods would have been rejected according to the significance testing criteria whereas all were acceptable by the fixed internal bias criteria. Precision can be effectively assessed for between- and within-run data by criteria set on unconfounded %RSD values or by separation of the sources of variation using an ANOVA approach applied to confounded data. The percentage of samples rejected for the 99% confidence interval applied to brackets, the multiple rules approach applied to the entire run, and the individual range chart approach applied to brackets were comparable and were found to be 7.0, 6.2 and 8.3 percent respectively. The ±20% fixed range criteria applied to the two-thirds of the run resulted in just 2.9% sample rejection and was not considered comparable to the other methods.

Beyond Section 504: Satisfaction and Empowerment of Students with Disabilities in Higher Education:

Abstract: College and university students with disabilities were surveyed to determine their levels of satisfaction with accessibility, special services, and accommodations at their schools. In addition, students were requested to identify barriers to postsecondary education, improvements in services, and other concerns. Respondents generally expressed satisfaction with the services that they had received. However, the majority indicated that they had encountered barriers to their education, including a lack of understanding and cooperation from administrators, faculty, staff, and other students; lack of adaptive aids and other resources; and inaccessibility of buildings and grounds. Recommendations were made for improving the delivery of services and self-advocacy of students with disabilities.

Potential risks and preventive measures for pulmonary aspiration: new concepts in preoperative fasting guidelines.

Abstract: he practice of safely preparing patients for anesthesia traditionally has included fasting for at T least 6 h preoperatively. This standard arose from concern for potential aspiration of gastric contents, a serious although infrequent complication. Although patient safety remains a paramount concern, patient comfort and logistical issues have led to continued attempts to define a minimally safe period of fasting. Many recent studies have examined the guideline of ”NPO after midnight” (NPO, nothing by mouth); they suggest that we may be able to safely liberalize the intake of clear fluids in selected patients, although this has by no means become routine clinical practice in all centers. Along with attempts to define a safe period of fasting for the healthy patient is the concern for reducing the potential for aspiration pneumonitis in high-risk patients. Our expanding pharmacopeia continues to be studied to define agents which will minimize risk and to establish rational guidelines for their use. This review discusses the pathophysiology of aspiration pneumonitis and the risk factors for its development as a background for examining the recent data regarding NPO status and its effect on gastric volume and pH. We will also present information on the use of pharmacologic adjuncts for reducing the risk of aspiration.

Peer drug associations and emotional restraint: causes or consequences of adolescents' drug use?

Abstract: A 3-wave longitudinal design was used to examine the relationships among emotional restraint, peer drug associations, and gateway drug use in a sample of 1,256 middle school students. Structural equation modeling was used to compare 3 models: (a) One model viewed drug use as a consequence of emotional restraint and peer variables; (b) 1 viewed drug use as a cause of restraint and peer variables, and (c) 1 included reciprocal effects. All 3 models fit the data fairly well. However, the reciprocal model fit the data significantly better than either of the others. Within this model, low emotional restraint was significantly related to subsequent increases in gateway drug use among boys. In contrast, peer drug models and peer pressure were not related to subsequent changes in gateway drug use. Changes in peer drug models were, however, predicted by previous levels of gateway drug use. Peer drug associations have been identified as one of the most important correlates of drug use in adolescents (Chassin, 1984; Hawkins, Lishner, Catalano, & Howard, 1986; Kandel, 1980). As such, peer variables play an important role in many models of adolescent drug use including Jessor and Jessor's (1977) problem behavior theory; the social learning model of Akers, Krohn, Lanza-Kaduce, and Radosevich (1979); and Kandel's (1980) socialization theory. Although various theories emphasize the role of peers in adolescents' drug use, the strongest position is taken by Getting and Beauvais's (1986, 1987) peer cluster theory, which states that peer variables not only dominate the prediction of drug use but mediate the effects of other variables. They argued that, whereas other psychosocial variables may create the potential for drug use, this potential is nearly always realized through interactions with peers. They contend that peers initiate youth into drugs, provide drugs, model drug-using behaviors, and shape attitudes about drugs. In a recent cross-sectional study, Swaim, Getting, and Beauvais (1989) used a model based on peer cluster theory to examine the relationships among emotional distress, peer variables, and drug use. Peer variables were hypothesized to have a direct effect on drug use; emotional distress variables including selfesteem, depression, anxiety, and blame-alienation were hy

A Multicenter Study on the Use of Pulsed Low-Intensity Direct Current for Healing Chronic Stage II and Stage III Decubitus Ulcers

Abstract: Background and Design: Pulsed low-intensity direct current (300 to 600 μA) has been used in a double-blind placebo multicenter study in the treatment of stage II and stage III chronic decubitus ulcers. Results: Seventy-four ulcers were treated in four centers. Forty-three patients were selected for the experimental group, and 31 control subjects used the sham instrument (placebo group). In the treated group, 25 ulcers (58%) healed in 8 weeks, whereas in the placebo group, only one ulcer (3%) healed and most ulcers increased in size. Statistical analysis, based on surface area and ulcer depth before and after treatment, showed that lowintensity direct current had a significant influence on the healing rates for these ulcers ( P Conclusions: Pulsed low-intensity direct current represents a useful approach for the treatment of stage II and stage III chronic decubitus ulcers by increasing the healing rate. The growth of fibroblasts and keratinocytes may be enhanced by pulsed low-intensity direct current due to changes in calcium homeostasis. ( Arch Dermatol. 1993;129:999-1009)

The efficacy and cost-effectiveness of adjuvant therapy of early breast cancer in premenopausal women.

Abstract: PURPOSE AND METHODSWe used decision analysis to model the natural history of breast cancer in hypothetical cohorts of 45-year-old women receiving tamoxifen, chemotherapy, or combined therapy. We used recurrence and efficacy data from the Early Breast Cancer Trialists' Collaborative Group (EBCTCG), utility values from focus groups, and costs from clinic charges and Medicare data.RESULTSTamoxifen alone provides minimal benefit in estrogen receptor-negative (ER-; 0.2 to 0.4 months) and modest benefit in receptor-positive (ER+; 3.5 to 5.2 months) cancer. Chemotherapy adds substantial benefit independent of receptor status (4.9 to 10.7 quality-adjusted months). In ER+ cancer, combined therapy adds an additional benefit (1.2 to 2.1 months) compared with chemotherapy alone. The incremental costs (United States dollars) necessary to add an additional year of life to the average woman ranged from $4,300 to $11,400 for tamoxifen alone for ER+ cancer, $4,900 to $11,400 for chemotherapy alone, and $14,800 to $33,100 ...

Behavioral Protection by Moderate Hypothermia Initiated After Experimental Traumatic Brain Injury

Abstract: The effects of postinjury hypothermia on behavioral outcome following moderate fluid percussion traumatic brain injury (TBI) were examined. In Experiment I, three groups of rats were examined. The first group was normothermic (37.5°C); and hypothermia (30°C) was initiated 15 min and 30 min postinjury in the second and third groups, respectively. Whole body cooling was achieved by ventral ice pack. Cooling of the brain to 30°C was achieved in 25 min and maintained for 60 min. Brain temperature was measured indirectly by a probe in the temporalis muscle. Behavioral outcome was assessed by beam-balance performance, beam-walking performance, and body weight loss measured daily for 5 days after TBI. Both the normothermic group and the 30-min postinjury hypothermic group exhibited significant (p < 0.05) beam-balance and beam-walking deficits on days 1 through 5 after TBI. In contrast, the 15-min postinjury hypothermic group exhibited significant (p < 0.05) beamwalking deficits only on day 1 after TBI a...