Biomedical subjects

Loring W Rue

Publications and source records attributed to Loring W Rue.

At least 37 records · Page 2Linked to original sources

PubMed2005

The financial impact of delayed discharge at a level I trauma center.

BACKGROUND: Delayed discharge is a costly phenomenon that takes place in every hospital system in the country, with significant operational consequences. The purpose of this study was to identify reasons for delayed discharge and evaluate the financial implications at a Level I trauma center. METHODS: Patients admitted to a Level I trauma center from September 2001 through June 2003 were classified with respect to those who did and did not experience a delay in discharge. RESULTS: For every 25 patients admitted to the trauma center, 1 experienced a delay in discharge, with an average delay of 6 days. The majority of the delays in discharge were attributable to difficulties in patient placement, such as lack of a rehabilitation or subacute hospital bed. Total hospital charges for excess days in the hospital for patients experiencing a delay in discharge were $2,455,703 per year and total costs were $715,403 per year. Patients with delayed discharge tended to be older, female, more severely injured, and more likely to have government-sponsored insurance. CONCLUSION: This study suggests that the main cause of delayed discharge from trauma centers is a consequence of limitations in posthospital care. Strategies must be identified to reduce the barriers to posthospital care to reduce these delays in discharge, lower unnecessary hospital costs, and ensure the financial viability of trauma centers and continuation of clinical services to the communities they serve.

Alabama↗

PubMed2004

Transgenic prolactin-/- mice: effect of trauma-hemorrhage on splenocyte functions.

Prolactin (PRL) is involved in the regulation of immune functions under normal and pathological conditions. Trauma-hemorrhage (T-H) produces profound immunosuppression in male mice but not in proestrus female mice. Administration of PRL in males after T-H, however, restores immune functions. In this study, PRL(+/+) and transgenic (PRL(-/-)) male and female mice were used to assess immune suppression after T-H and to determine the reasons for the hormone's beneficial effect. In vitro lymphoproliferation assay with Nb2 cells showed complete absence of PRL in the circulation of the transgenic PRL(-/-) mice of both sexes, whereas very high levels of the hormone were detected in the wild-type PRL(+/+) mice of both sexes. Moreover, T-H resulted in the appearance of significant levels of the hormone in circulation, but only in PRL(+/+) mice. Splenocyte proliferation in male PRL(-/-) mice was significantly lower than in PRL(+/+) mice after T-H. Marginal differences between PRL(+/+) and PRL(-/-) mice were observed in the release of IL-2 and IFN-gamma by splenocytes, while the release of IL-10 was significantly higher in PRL(-/-) than in PRL(+/+) mice. A significant observation of our study is the release of a approximately 25-kDa protein in the concanavalin A-stimulated splenocytes of male PRL(+/+) and PRL(-/-) mice that was active in the in vitro lymphoproliferation assay with Nb2 cells. It is unlikely that this protein is PRL because it is also present in the splenocyte extracts of PRL(-/-) transgenic mice. Nonetheless, because control of lymphoid cell proliferation is considered one of the characteristics of the immune system, the local release of this protein may be significant in the differences observed in splenocyte cytokine release after T-H in wild-type as well as transgenic mice.

Animals↗

PubMed2004

Splenectomy differentially influences immune responses in various tissue compartments of the body.

Patients without spleens have an increased risk of infection. Previous studies have shown that splenectomy (Spx) influences Kupffer cells (KC), peritoneal macrophages (pMphi) and alveolar macrophages (aMphi) phagocytosis and bactericidal activity. This study examined the effect of Spx on the cytokine production by peripheral blood monocular cells (PBMC), KC, aMphi, pMphi and cells from mesenteric lymph nodes (MLN). We also determined if Spx influences survival following sepsis induced by cecal ligation and puncture (CLP). C57BL/6J male mice (8-10 weeks old) underwent sham operation or Spx. Two weeks after sham or Spx, KC, pMphi, aMphi, PBMC and cells from MLN were isolated and stimulated with LPS. Cell-free supernatants were analyzed for TNF-alpha, IL-6, and IL-10. A significant increase in KC, pMphi and aMphi TNF-alpha and IL-6 release was observed following Spx. The production of IL-10 was also significantly higher in KC under those conditions. In contrast, the release of TNF-alpha, IL-6 and IL-10 was significantly decreased in PBMC after Spx. Similarly, TNF-alpha and IL-6 was also decreased in MLN after Spx. Overall survival after CLP was not different in mice subjected to either sham or Spx. However, the mean time to death was significantly decreased in mice subjected to Spx compared to sham injured mice. These findings suggest that Spx modulates immune cell functions in various tissue compartments of the body and results in early deaths following sepsis.

Animals↗

PubMed2004

Mechanism of salutary effects of androstenediol on hepatic function after trauma-hemorrhage: role of endothelial and inducible nitric oxide synthase.

Recent studies have shown that administration of dehydroepiandrosterone (DHEA) after trauma-hemorrhage (T-H) improves cardiovascular and hepatic function in male animals. Although androstenediol, one of the DHEA metabolites, has been recently reported to produce salutary effects on cardiac function and splanchnic perfusion after T-H, it remains unknown whether androstenediol per se has any salutary effects on hepatic function under those conditions. To study this, male Sprague-Dawley rats underwent laparotomy and approximately 90 min of hemorrhagic shock (35-40 mmHg), followed by resuscitation with four times the shed blood volume in the form of Ringer lactate. Androstenediol (1 mg/kg body wt iv) was administered at the end of resuscitation, and the animals were killed 24 h later. T-H significantly reduced portal blood flow, bile production, and serum albumin levels. Portal pressure, serum alanine aminotransferase, hepatic nitrate/nitrite, inducible nitric oxide synthase (iNOS), and endothelin-1 markedly increased after T-H. The alterations in these parameters induced by T-H were significantly attenuated in rats treated with androstenediol. Endothelial NOS (eNOS) expression, which was not different between T-H and sham, was found to be significantly elevated in T-H androstenediol-treated rats. These data suggest that improvement in hepatic perfusion by androstenediol after T-H is likely due to a decrease in endothelin-1 and induction of eNOS. Moreover, the decrease in hepatic damage after androstenediol administration is likely related to liver iNOS downregulation. Thus androstenediol appears to be a novel and useful adjunct for restoring hepatic function in male animals after adverse circulatory conditions.

Androstenediol↗

PubMed2004

Insights into the role of interleukin-6 in the induction of hepatic injury after trauma-hemorrhagic shock.

Although systemic interleukin-6 (IL-6) level is elevated, hepatocellular function is impaired and liver injury occurs after trauma-hemorrhage (T-H), it remains unknown whether a causal relationship exists between elevated IL-6 levels and liver injury after T-H. We hypothesized that IL-6 is causative in the development of hepatic dysfunction and injury after T-H. To examine this, adult male Sprague-Dawley rats underwent a 5-cm midline laparotomy and were subjected to hemorrhagic shock (blood pressure = 35 mmHg for approximately 90 min), followed by resuscitation (Ringer lactate, 4 times the shed blood volume). At 2, 5, and 24 h thereafter, blood samples were collected and the liver isolated and perfused for 60 min. Portal inflow pressure was measured, and perfusate samples were collected to measure IL-6, alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels. A significant positive correlation between plasma levels of IL-6 and ALT and perfusate levels of IL-6 and LDH levels was observed. In a second series of experiments, rats were treated with immunoglobulin G (IgG) or antibodies against rat IL-6 (anti-IL-6) at the onset of resuscitation. At 5 h after resuscitation, anti-IL-6 treatment attenuated the T-H induced increases in plasma ALT and thromboxane B(2) (a thromboxane A(2) metabolite) levels, and bile flow was normalized to sham levels. Perfusion of livers from normal rats with IL-6 did not alter portal pressure; however, perfusion of a stable thromboxane A(2) analog dose dependently increased portal pressure. Thus IL-6 plays a significant role in the induction of hepatic dysfunction and liver injury after T-H that appears to be in part mediated by increased thromboxane A(2) levels.

Alanine Transaminase↗

PubMed2004

Are the immune responses different in middle-aged and young mice following bone fracture, tissue trauma and hemorrhage?

Although immune responses following soft-tissue trauma-hemorrhage are markedly different in young (6-8 weeks) and aged (18-20 months) mice, it remains unknown if there are any differences in immune responses in middle-aged and young mice following bone fracture, soft-tissue trauma-hemorrhage (Fx-TH). To study this, young (6-8 weeks) and middle-aged (approximately 12 months) C3H/HeN male mice were subjected to sham operation or Fx-TH followed by resuscitation with Ringer's lactate. The mice were sacrificed 2 h thereafter and splenocytes, bone marrow cells (BM) and Kupffer cells (KC) were harvested, purified and stimulated with ConA (for splenocytes) or LPS (for BM and KC) in vitro. Splenocyte release of Th1 (IL-2 and IFN-gamma) cytokines was decreased and Th2 (IL-4 and IL-10) cytokine release was increased following Fx-TH in both young and middle-aged mice. However, the decrease in IL-2 and increase in IL-10 were significantly more in middle-aged mice compared to young mice (p < 0.05). Furthermore, splenocyte proliferation was decreased more in middle-aged mice compared to young mice following Fx-TH (p < 0.05). Additionally, TNF-alpha production was more in BM from middle-aged compared to BM from young mice after Fx-TH (p < 0.05). The production of IL-6 and IL-10 was also significantly higher in KC from middle-aged mice compared to young ones following Fx-TH. These results suggest that at middle age, the immune responses to Fx-TH are significantly different from those observed in young mice in different compartments of the body. Although the mechanism of the difference in various compartments in middle-aged vs. young mice following Fx-TH remains unknown, the decreased IL-2 production along with other altered T cell and macrophage functions may contribute to an increased susceptibility to sepsis in middle-aged vs. young individuals.

Age Factors↗

PubMed2004

Alpha1-acid-glycoprotein protects against trauma-hemorrhagic shock.

BACKGROUND: Recent studies have shown that the acute phase protein alpha(1)-acid-glycoprotein (AAG) directly modifies endothelial cell responsiveness and is a crucial factor for maintaining endothelial barrier function. We hypothesized that the addition of AAG to the resuscitation fluid will prevent edema formation, increases circulating blood volume, and reduces tissue inflammation following soft tissue trauma and hemorrhagic shock. MATERIALS AND METHODS: Male Sprague-Dawley rats (338 +/- 28 g) underwent a 5-cm midline laparotomy (i.e., induction of soft tissue trauma) and were bled to and maintained at a mean arterial pressure of 35 mm Hg for 90 min. The rats were then resuscitated with four times the shed blood volume with Ringer's lactate containing 200 mg/kg AAG or the same amount of albumin. At 6 h after resuscitation, organ wet-to-dry weight ratios and circulating blood volume (Evans blue dilution) were determined. Neutrophil accumulation (myeloperoxidase activity, MPO) and tissue lipid peroxidation (thiobarbituric acid reactive substances) were also measured in the lungs, liver, and intestine. RESULTS: Administration of AAG during the resuscitation significantly increased circulating blood volume and reduced edema formation, neutrophil accumulation, and lipid peroxidation. Interestingly, concomitant plasma IL-6 levels increased while TNF-alpha levels were not significantly affected. CONCLUSIONS: Since addition of AAG to the resuscitation fluid increased circulating blood volume, reduced edema formation, and neutrophil accumulation following trauma and hemorrhagic shock, supplementation of this acute phase protein appears to be a potential adjunct to prevent capillary leakage in patients undergoing major traumatic injury.

Animals↗

PubMed2004

Salutary effects of androstenediol on cardiac function and splanchnic perfusion after trauma-hemorrhage.

Recent studies have shown that dehydroepiandrosterone (DHEA) administration after trauma-hemorrhage (T-H) improves cardiovascular function and decreases cytokine production in male animals. Although androstenediol, one of the metabolites of DHEA, is reported to have estrogen-like activity, it remains unknown whether androstenediol per se has any salutary effects on cytokines and cardiovascular function after T-H. To examine this effect, male Sprague-Dawley rats underwent laparotomy and were bled to and maintained at a mean arterial blood pressure of 35-40 mmHg for approximately 90 min. The animals were resuscitated with four times the volume of maximal bleedout volume in the form of Ringer lactate. Androstenediol (1 mg/kg body wt i.v.) or vehicle was administered at the end of resuscitation. Twenty-four hours after resuscitation, cardiac function and organ blood flow were measured by using (85)Sr-microspheres. Circulating levels of nitrate/nitrite and IL-6 were also determined. Cardiovascular function and organ blood flow were significantly depressed after T-H. However, these parameters were restored by androstenediol treatment. The elevated plasma IL-6 levels after T-H were also lowered by androstenediol treatment. In contrast, plasma levels of nitrate/nitrite were the highest in the androstenediol-treated T-H animals. Because androstenediol administration after T-H decreases cytokine production and improves cardiovascular function, this agent appears to be a novel and useful adjunct for restoring the depressed cardiovascular function and for cytokine production in males after adverse circulatory conditions.

Anabolic Agents↗

PubMed2004

Cervical spine injury and restraint system use in motor vehicle collisions.

CONTEXT: Cervical spine injury related to motor vehicle collision (MVC) is a severe and often permanently disabling injury. Although advances in automobile crashworthiness have reduced both fatalities and some severe injuries, the impact of varying occupant restraint systems (seatbelts and airbags) on cervical spine injury is unknown. OBJECTIVE: To investigate the relationship between the occurrence of cervical spine injury and occupant restraint systems among front seat occupants involved in frontal MVCs. DESIGN, SETTING, AND PATIENTS: A case-control study among subjects obtained from the 1995 to 2001 National Automotive Sampling System (NASS). Cases were identified based on having sustained a cervical spine injury score of 2 or more on the Abbreviated Injury Scale, 1990 Revision. RESULTS: Approximately half (44.7%) of 8,412 cases of cervical spine injury were unrestrained occupants while belted only, airbag only, and both restraint systems represented 38.2%, 8.8%, and 8.4% of cases, respectively. Overall, the combined use of airbag and seatbelt had the greatest protective effect, relative to unrestrained occupants, with an odds ratio (OR) of 0.19 and a 95% confidence interval (CI) of 0.12 to 0.30. Use of a seatbelt only also had a protective effect (OR: 0.40; 95% CI: 0.23-0.70). Occupant use of an airbag only neither increased nor decreased the risk of cervical spine injuries relative to unrestrained occupants (OR: 1.02; 95% CI: 0.57-2.13). CONCLUSIONS: The results of this study suggest that there is an increase in overall protection against cervical spine injury by combining airbag and seatbelt restraint systems relative to seatbelt alone.

Accidents, Traffic↗

PubMed2004

Sex steroid-mediated regulation of macrophage/monocyte function in a two-hit model of trauma-hemorrhage and sepsis.

Studies have shown that 17beta-estradiol has salutary effects on immune functions after trauma-hemorrhage (TH). It remains unknown, however, whether 17beta-estradiol has a similar effect in a double-hit model of TH and subsequent sepsis. It is also unknown if under those conditions the circulating immune cells accurately represent immunological responses occurring in fixed tissues, such as the spleen. To study this, pre-castrated mice were hormonally treated and then subjected to soft-tissue trauma (i.e. midline laporatomy), hemorrhagic shock (MAP 35+/-5mmHg for 90 min followed by resuscitation) and 24 h later sepsis was induced by cecal ligation and puncture (CLP). Splenic macrophages (SMphi) and peripheral blood mononuclear cells (PBMC) were isolated and cultured with LPS. 5alpha-Dihydrotestosterone-treated mice showed a depressed pro-inflammatory cytokine production after TH-sepsis in both SMphi and PBMC. In contrast, the 17beta-estradiol treated groups showed suppressed pro-inflammatory cytokine production in the PBMC population under those conditions. In summary, 17beta-estradiol was able to prevent immune dysfunction after TH and subsequent sepsis. However, the beneficial effects of 17beta-estradiol were limited to tissue-fixed Mphi, suggesting compartmentalization of the response. Thus, events occurring in the tissue-fixed cells are not necessarily reflected in the circulating PBMC population.

Animals↗

PubMed2004

Role of IL-10 in regulating proinflammatory cytokine release by Kupffer cells following trauma-hemorrhage.

IL-6 and TNF-alpha production by Kupffer cells is markedly stimulated following trauma-hemorrhage (T-H). Because IL-10 is an anti-inflammatory cytokine, the aim of this study was to determine whether IL-10 regulates Kupffer cell proinflammatory cytokine release following T-H. To study this, we subjected adult male Sprague-Dawley rats to sham operation or T-H. The procedure involved a 5-cm midline laparotomy and approximately 90 min of hemorrhagic shock (35 mmHg), followed by resuscitation with four times the shed blood volume in the form of Ringer's lactate. At 2 h after the end of resuscitation, livers were perfused in vitro and perfusate was collected. In separate studies, Kupffer cells were isolated and incubated with different concentrations of anti-IL-10 MAb. IgG was used as control. After 16 h of incubation, IL-6 and TNF-alpha levels were measured by ELISA. Plasma IL-10 levels increased significantly following T-H. IL-10 levels in the perfusate and IL-10 production by cultured Kupffer cells were also significantly higher in the T-H group. When Kupffer cells were incubated with 10 microg/ml of anti-IL-10 MAb, IL-6 and TNF-alpha production were significantly increased in both sham and T-H groups compared with those not treated with anti-IL-10 MAb. However, these changes were not observed when the cells were incubated with irrelevant (control) IgG. These results indicate that IL-10 production by Kupffer cells early after T-H may play a pivotal role in attenuating the proinflammatory cytokine environment, possibly in an autocrine/paracrine manner.

Animals↗

PubMed2004

The effect of inhibition of a major cell signaling pathway following trauma hemorrhage on hepatic injury and interleukin 6 levels.

HYPOTHESIS: Recent studies have shown that intracellular signaling pathways, such as the mitogen-activated protein kinases, play a pivotal role in the activation of the inflammatory response. We hypothesized that administration of a specific mitogen-activated protein kinase inhibitor, PD 98059, at the end of resuscitation following severe hemorrhagic shock can reduce the plasma levels of interleukin 6 (IL-6) and hepatocellular damage. DESIGN: Prospective controlled animal study. SETTING: Medical school-affiliated university hospital. INTERVENTIONS: Male Sprague-Dawley (275-325 g) rats underwent laparotomy (ie, soft tissue trauma) and were then bled to a mean arterial pressure of 40 mm Hg for approximately 90 minutes. The animals were then resuscitated with 4 times the bleed-out volume using Ringer lactate solution for 60 minutes. PD 98059, an inhibitor of extracellular signal-regulated kinases (ERKs) 1 and 2 (750 mmol/L), or vehicle (dimethyl sulfoxide and isotonic sodium chloride solution) was administered intravenously as a bolus at the end of resuscitation. MAIN OUTCOME MEASURES: At 24 hours after resuscitation or sham operation, plasma levels of IL-6 and alpha-glutathione S-transferase were determined with enzyme-linked immunosorbent assay and enzyme immunoassay, respectively. Moreover liver sections were stained with monoclonal antibody against the phosphorylated form of ERKs. RESULTS: At 24 hours following trauma hemorrhage and resuscitation, plasma levels of IL-6 and alpha-glutathione S-transferase were markedly elevated. Administration of PD 98059, however, reduced levels to sham values. Moreover, liver expression of phosphorylated ERKs was found in the cytosol and nuclear compartment of hepatocytes only following trauma hemorrhage. CONCLUSION: Administration of PD 98059 (ie, inhibition of intracellular signaling pathways) may represent a feasible approach to blunt the inflammatory response and improve outcome following traumatic injuries and hemorrhagic shock.

Analysis of Variance↗

PubMed2004

Effect of restraint systems on maxillofacial injury in frontal motor vehicle collisions.

PURPOSE: Motor vehicle collisions (MVCs) are the leading cause of maxillofacial fractures. Additionally, maxillofacial injuries are the most common injury related to air bag deployment. We sought to characterize the occupant restraint system (seat belt and air bag) and collision characteristics associated with MVC-related maxillofacial injuries. MATERIALS AND METHODS: The 1991-2000 National (United States) Automotive Sampling System Crashworthiness Data System (CDS) data files were used. The CDS is a national probability sample of passenger vehicles involved in police-reported tow-away MVCs. Analysis was limited to front seat occupants involved in frontal collisions of delta-V (estimated change in velocity) of greater than 15 km/hr. The risk of facial injury was calculated according to occupants' restraint use (unrestrained, seat belt only, air bag only, and seat belt and air bag combined) and compared using risk ratios (RRs) and associated 95% confidence intervals (CIs). RESULTS: Occupants restrained with a seat belt only (RR, 0.48; 95% CI, 0.40 to 0.57) or a seat belt and an air bag (RR, 0.83; 95% CI, 0.73 to 0.94) had a significantly reduced risk of any facial injury compared with completely unrestrained occupants. There was no association for those restrained with an air bag only (RR, 1.19; 95% CI, 0.82 to 1.73). A similar pattern of results was observed for moderate to severe facial injuries and for facial fractures. CONCLUSION: Seat belt use significantly reduces the risk of facial injury in frontal MVCs. Air bag use was not associated with the risk of facial injury.

Accidents, Traffic↗

PubMed2004

Frequency of maxillofacial injuries in all-terrain vehicle collisions.

PURPOSE: We sought to evaluate the frequency and distribution of maxillofacial injuries associated with all-terrain vehicle (ATV) collisions and to compare this with patients involved in motorcycle accidents over the same 5-year period at the University of Alabama at Birmingham. Patients and methods The records of all patients involved in ATV collisions who were admitted to the University of Alabama at Birmingham Trauma Center from January 1998 to January 2003 were reviewed. Age, gender, mechanism of injury, length of stay, Glasgow Coma Scale (GCS) score, maxillofacial injuries, Injury Severity Score (ISS), and maxillofacial Abbreviated Injury Scale (AIS) score were the factors considered for the study. These variables were also analyzed for patients involved in motorcycle collisions who sustained maxillofacial trauma. RESULTS: There were a total of 72 ATV collisions; 23 patients (32%) sustained maxillofacial injuries. The mean age was 31, and there were 59 males (82%) and 13 females (18%). The most common mechanism of injury was an ATV rollover. The warmer seasons and weekend days had the highest frequency of ATV trauma. Of the 23 patients who sustained maxillofacial injuries, the average maxillofacial AIS score was 2. The length of stay and GCS score were 8 days and 12, respectively, compared to 5 days and 15 in the nonmaxillofacial injury group. The most common maxillofacial fracture seen was a zygomaticomaxillary complex fracture (n = 8), followed by mandibular fractures (n = 6), and orbital floor blowout fractures (n = 5). Eighty-three percent of patients with maxillofacial injuries required an operative intervention during their hospitalization. The distribution of maxillofacial fractures in the ATV group was similar to that of an equivalent motorcycle group, but the frequency for the ATV group was higher (32% versus 8%). The length of stay for the motorcycle group was 11 days versus 8 days for the ATV group. The GCS scores, maxillofacial AIS scores, and ISS were similar between the 2 groups (12, 2, and 18, respectively). In patients who sustained maxillofacial fractures, neurologic injuries were the most frequent concomitant injury in the ATV group, whereas orthopedic injuries occurred more often in the motorcycle group. CONCLUSIONS: Maxillofacial injuries are common findings in ATV collisions. ATV patients with maxillofacial fractures have more neurologic impairment at admission and longer hospitalizations than patients sustaining motorcycle injuries. There needs to be an increase in the public health effort to educate individuals about the dangers of ATVs and to provide proper safety guidelines before the purchase of a vehicle.

Accidents↗

PubMed2004

Estradiol's effect on portal response to endothelin-1 after trauma-hemorrhage.

BACKGROUND: The fine balance between vasoconstrictors and vasodilators maintains portal circulation. Studies have shown that portal response to endothelin-1 (ET-1), a potent vasoconstrictor, is enhanced following hemorrhagic-shock, which subsequently leads to the impaired hepatic circulation and hepatic damage. Although protective effects of 17beta-estradiol (E(2)) against hepatic damage following trauma-hemorrhage have been observed, it remains unknown whether E(2) directly improves hepatic circulation. We hypothesized that the salutary effects of E(2) are mediated, at least in part, by the attenuation of portal response to ET-1 following trauma-hemorrhage. MATERIALS AND METHODS: Male adult Sprague-Dawley rats were randomly assigned to sham operation or trauma-hemorrhage with or without in vivo E(2) treatment. Trauma-hemorrhage included midline laparotomy and approximately 90 min of hemorrhagic shock (35 mmHg), then resuscitation with four times the shed blood volume with Ringer's lactate solution over 60 min. For the E(2) treatment group, 1 mg/kg of E(2) was added to the Ringer's lactate solution. At 5 h after the end of resuscitation, the liver was isolated and perfused in vitro to measure portal pressure responses to exogenous ET-1 (60 pmol in 150 ml perfusate, bolus) with or without E(2) (1,500 pg/ml). RESULTS: Peak portal pressure after the administration of ET-1 was significantly higher in vehicle-treated trauma-hemorrhage group compared with the sham group. This effect was significantly attenuated in the E(2) treatment group. Furthermore, E(2) treatment restored bile production and prevented hepatic damage following trauma-hemorrhage. CONCLUSIONS: The beneficial effects of estradiol observed following trauma-hemorrhage, at least partly, are caused by the attenuation of portal pressure response to increased ET-1.

Animals↗

PubMed2004

The effect of state motorcycle licensing laws on motorcycle driver mortality rates.

OBJECTIVE: The purpose of this study was to evaluate the association between motorcycle licensing and operation regulations and motorcycle mortality rates in the United States during 1997 through 1999. METHODS: A population-based ecologic study was used. RESULTS: Lower mortality rates were observed in states with the following motorcycling requirements: skill test for a motorcycle permit (rate ratio [RR], 0.76; 95% confidence interval [CI], 0.69-0.84), driver training (RR, 0.80; 95% CI, 0.74-0.86), longer duration of learner's permits (95-190 days [RR, 0.86; 95% CI, 0.79-0.95] and >190 days [RR, 0.87; 95% CI, 0.81-0.93], three or more learner's permit restrictions (RR, 0.78; 95% CI, 0.73-0.84), and a full helmet law (RR, 0.76; 95% CI, 0.71-0.81). CONCLUSION: Specific motorcycle licensure policies appear to be associated with lower mortality rates.

Accidents, Traffic↗

PubMed2004

The applicability of a computer model for predicting head injury incurred during actual motor vehicle collisions.

BACKGROUND: Head injury is a significant cause of both morbidity and mortality. Motor vehicle collisions (MVCs) are the most common source of head injury in the United States. No studies have conclusively determined the applicability of computer models for accurate prediction of head injuries sustained in actual MVCs. This study sought to determine the applicability of such models for predicting head injuries sustained by MVC occupants. METHODS: The Crash Injury Research and Engineering Network (CIREN) database was queried for restrained drivers who sustained a head injury. These collisions were modeled using occupant dynamic modeling (MADYMO) software, and head injury scores were generated. The computer-generated head injury scores then were evaluated with respect to the actual head injuries sustained by the occupants to determine the applicability of MADYMO computer modeling for predicting head injury. RESULTS: Five occupants meeting the selection criteria for the study were selected from the CIREN database. The head injury scores generated by MADYMO were lower than expected given the actual injuries sustained. In only one case did the computer analysis predict a head injury of a severity similar to that actually sustained by the occupant. CONCLUSION: Although computer modeling accurately simulates experimental crash tests, it may not be applicable for predicting head injury in actual MVCs. Many complicating factors surrounding actual MVCs make accurate computer modeling difficult. Future modeling efforts should consider variables such as age of the occupant and should account for a wider variety of crash scenarios.

Accidents, Traffic↗

PubMed2004

Preexisting conditions and mortality in older trauma patients.

BACKGROUND: Among older trauma patients, those with preexisting chronic medical conditions (CMCs) appear to have an elevated risk of death. Whether this association is dependent on the severity of injury or other occult factors remains unanswered. This study evaluated the association between preexisting CMCs and risk of death among older trauma patients according to injury severity. METHODS: This was a retrospective cohort study using data from the National Trauma Data Bank, a registry of trauma patients admitted to 131 trauma centers across the United States. The main outcome measure was in-hospital mortality. RESULTS: In patients 50 to 64 years of age who sustain severe (Injury Severity Score [ISS] of 26+) and moderate injuries (ISS of 16-25), the presence of one or more CMCs is not associated with an increased relative risk (RR) of death (RR, 0.80 and 95% confidence interval [CI], 0.71-0.90; RR, 1.09 and 95% CI, 0.95-1.24, respectively). Those with minor injuries (ISS < 16) have increased risk of death (RR, 2.80; 95% CI, 2.33-3.36). For those patients 65 years of age and older who sustain severe, moderate, and minor injuries, the pattern of results is similar (RR, 0.91 and 95% CI, 0.83-1.00; RR, 1.13 and 95% CI, 1.04-1.23; and RR, 1.88 and 95% CI, 1.73-2.05, respectively). CONCLUSION: Older trauma patients with CMCs who present with minor injuries should be considered to have an increased risk of death when compared with their nonchronically ill counterparts.

Aged↗