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Biomedical subjects

S E Ross

Publications and source records attributed to S E Ross.

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

Reintubation as an outcome predictor in trauma patients.

STUDY OBJECTIVE: Determine reintubation rate, identify its cause, and detail adverse outcomes from reintubation. DESIGN: Retrospective review of extubation failures in the trauma ICU. SETTING: University hospital and regional trauma center. PATIENTS: Four hundred five patients arriving intubated or requiring intubation during hospitalization after 2,516 traumatic injury admissions over 18 months. INTERVENTIONS: None. RESULTS: Reintubation incidence was 7% (27 times per 405 patients). Comparative mortality of the reintubated group (2/24 = 8%) is similar to overall trauma center mortality (224/2516 = 6.5%), but less than the cohort of patients admitted to the hospital intubated (63/405 = 16%). Reintubated patients had an increased frequency of stridor than reported previously (33%), and an increased tracheostomy rate (62% vs 30%). Stridor was not predictable from injury severity score, Glasgow coma score, age, sex, length of intubation, or place of intubation. Pulmonary complications (atelectasis, tracheobronchitis, pneumonia) developed in half of reintubated patients; stridorous patients did not have an increased rate of pulmonary complications. CONCLUSION: Reintubation in trauma ICU patients does not predict poor outcome.

Adolescent↗
PubMed1995

Desensitization of Ras activation by a feedback disassociation of the SOS-Grb2 complex.

Activation of Ras by the exchange of bound GDP for GTP is predominantly catalyzed by the guanylnucleotide exchange factor SOS. Receptor tyrosine kinases increase Ras-GTP loading by targeting SOS to the plasma membrane location of Ras through the small adaptor protein Grb2. However, despite the continuous stimulation of receptor tyrosine kinase activity, Ras activation is transient and, in the case of insulin, begins returning to the GDP-bound state within 5 min. We report here that the cascade of serine kinases activated directly by Ras results in a mitogen-activated protein kinase kinase (MEK)-dependent phosphorylation of SOS and subsequent disassociation of the Grb2-SOS complex, thereby interrupting the ability of SOS to catalyze nucleotide exchange on Ras. These data demonstrate a molecular feedback mechanism accounting for the desensitization of Ras-GTP loading following insulin stimulation.

3T3 Cells↗
PubMed1995

Morbidity of negative coeliotomy in trauma.

Exploratory coeliotomy is essential in the care of abdominal trauma, but negative operation has a reported morbidity rate as high as 18 per cent. Ancillary studies such as computerized tomography, diagnostic peritoneal lavage and abdominal ultrasound have improved both sensitivity and specificity of evaluation in blunt and penetrating trauma, thus decreasing the rate of negative coeliotomy. A retrospective study of 50 consecutive negative laparotomies (10.5 per cent of all trauma laparotomies) at our Trauma Center revealed a morbidity rate of 22 per cent and mortality of 6 per cent. Although the negative coeliotomy rate was lower for blunt than penetrating trauma, morbidity was significantly higher for blunt trauma. Extra-abdominal injury alone could not account for this difference. We conclude that negative coeliotomy in penetrating trauma does not carry excessive morbidity. Negative coeliotomy in blunt trauma is accompanied by high morbidity and mortality, so adjunct diagnostic procedures should be utilized in this population in an effort to minimize negative laparotomies.

Abdomen↗
PubMed1995

Diagnosis of unsuspected facial fractures on routine head computerized tomographic scans in the unconscious multiply injured patient.

PURPOSE: This article assessed the value of routine head computerized axial tomographic (CT) scans for diagnosis of unsuspected facial fractures and its clinical implications in the multiply injured patient who is intubated, unconscious, or sedated at the time of initial assessment and requires a head CT scan to assess for brain injury. METHODS: At a level I trauma center from June 1, 1992 to June 1, 1993 all intubated blunt trauma patients who required routine CT scan evaluation at initial assessment were studied prospectively. Routine scanning started at the foramen magnum and included the maxilla. Patients who died within the first 24 hours were excluded. RESULTS: The study population included 116 patients (85 male, 21 female) aged 12 to 85 years (mean, 28 years) with injury severity scores ranging from 1 to 50 (mean, 23). The mechanism of injury was: motor vehicle accidents (n = 74), motorcycling (n = 5), pedestrians accidents (n = 13), falls (n = 10), bicycling (n = 5), assaults (n = 8), and boating accident (n = 1). There were 19 suspected facial fractures; 18 required surgical repair. There were 27 unsuspected facial fractures; 13 required surgical care. Three suspected fractures were ruled out. CONCLUSION: Routine head CT scans to assess for brain injury in the multiply injured patient are also very useful in the diagnosis of unsuspected facial fractures, almost half of which will require surgical intervention.

Abbreviated Injury Scale↗
PubMed1995

Selective indications for thoracic and lumbar radiography in blunt trauma.

STUDY OBJECTIVE: To determine indications for thoracolumbar radiography. DESIGN: Case series with prospective data collection. SETTING: Level I trauma center. PARTICIPANTS: Blunt-trauma victims more than 12 years old who underwent routine thoracic and lumbar radiography according to institutional protocol. Patients were classified as group 1, not able to be evaluated clinically (Glasgow Coma Scale score of less than 13, intoxication, intubation, or cervical neurologic deficit); and group 2, able to be evaluated clinically. RESULTS: Twenty-four of 319 patients sustained 25 thoracic or lumbar fractures. Seven of 136 group 1 patients and 17 of 183 group 2 patients had fractures. Eight of 17 patients with pain and 9 of 17 with tenderness had fractures (P = .001). No group 2 patients without pain, tenderness, thoracic or lumbar neuro-deficit, or major distracting injury, including cervical fracture, had fractures. The negative predictive value of pain and tenderness was 95%. Five of 46 patients with spinal fractures at any level had multiple fractures. CONCLUSION: Blunt-trauma victims who cannot be evaluated clinically should undergo thoracolumbar radiography. Routine radiography may be unnecessary in asymptomatic patients who can be evaluated clinically and who do not have neurologic deficits or distracting injuries. Spinal fracture at any level mandates complete spinal radiography.

Adolescent↗
PubMed1995

Syncope as etiology of road crashes involving elderly drivers.

A significant number of elderly drivers present without discernible external cause for their road crash. We hypothesize that syncope may contribute to their crash etiology and prospectively evaluated drivers older than 60 years with unexplained crash, presenting to our trauma center during a 1-year period. Prehospital data and prior medical history were obtained on all, followed by a standard syncope work-up. Of 79 drivers ages 60-98, 58 (73%) were at fault in the crash. In 33 (57%), the crash etiology could not be determined. Thirteen had prior syncope history. Workup was negative in two patients, and six died or were transferred before evaluation. Twenty-five of 33 (76%) had positive workups for syncope: cardiac causes in 10; neurologic in seven; psychiatric in five, endocrine in two; one indeterminant. Ten of 18 who survived had license revocation for medical reasons. Syncopal episodes are a frequent contributor to unexplained crashes among elderly drivers and should be suspected whenever external causes are not apparent.

Accidents, Traffic↗
PubMed1995

Elderly drivers involved in road crashes: a profile.

The ability of elderly citizens to drive safely has been the subject of ongoing debate. To identify the type of elderly driver who becomes involved in an injury-producing road crash, we profiled all drivers over 39 years of age admitted to our Level I Trauma Center over a 1-year period. Data were prospectively collected and drivers age 40-59 years were compared with those over 60 years. Eighty-four drivers age > or = 60 and 130 drivers age 40-59 were studied. Of the 84 elderly drivers, 67 were deemed at fault. Twenty-four of those crashes were due to driving errors, 12 due to syncopes, and in 20 no crash cause was determined. Fifty-three of the 67 at fault drivers had significant underlying medical problems, compared to 9 of 17 deemed not at fault. Only four were legally intoxicated. Of the 130 drivers in the comparison group, only 19 had significant underlying medical problems; in three syncope was suspected; 18 were legally intoxicated. We conclude from our data that underlying medical disorders occur frequently in elderly drivers and may contribute to their incidence of road crashes.

Accidents, Traffic↗
PubMed1994

In vivo association of Grb2 with pp116, a substrate of the T cell antigen receptor-activated protein tyrosine kinase.

Numerous recent studies have implicated the src homology 2 and 3 domain-containing protein, Grb2, in coupling protein tyrosine kinase signaling pathways with the Ras signaling pathway. Ligation of the T cell antigen receptor results in the activation of both a PTK, and Ras; therefore, we investigated whether Grb2 may serve a similar function in T cells. Here we report that a GST/Grb2 fusion protein associates with several tyrosine phosphoproteins from lysates of T cell antigen receptor-stimulated Jurkat T cells. Two of these proteins, pp36 and pp116, bind to the Grb2 fusion protein with high affinity. Through the use of mutated Grb2 fusion proteins, we demonstrate that pp116 binds the amino-terminal src homology 3 domain of Grb2, the same domain of Grb2 thought to be primarily responsible for its interaction with SOS. We demonstrate further that pp116 associates with Grb2 in vivo, and we provide evidence that in the Jurkat T cell line Grb2 may exist complexed with either pp116 or with SOS.

Adaptor Proteins, Signal Transducing↗
PubMed1994

The association between CD45 and lck does not require CD4 or CD8 and is independent of T cell receptor stimulation.

CD45, the major transmembrane tyrosine phosphatase of lymphoid cells, is required for optimal signaling via a number of receptors. A model for how CD45 regulates signaling is that it controls phosphorylation of the COOH-terminal tyrosine of src family kinases. We have shown that CD45 physically associates with lck, one src kinase. Others have shown that CD45 also interacts with the CD4 and CD8 surface antigens expressed on many T cells. In this report we examine further the relationship between CD45 and lck in a CD4+ T cell line and in peripheral T cells. We show now that CD45 associates with lck independently of both CD4 and CD8. We show also the time course of an association between CD45 and a form of lck that migrates at an apparent higher molecular mass. Finally, we demonstrate that the interaction between CD45, lck, and a previously reported 32-34 kD protein is stable after stimulation of T cells.

Antigens, CD↗
PubMed1994

Penetrating posterior abdominal trauma.

Wounds of the back and flank pose a risk of injury to retroperitoneal structures which may be missed on physical examination. Recently, a selective approach to these wounds has been advocated. In order to document the incidence, management, and outcome of patients with penetrating wounds of the back and flank, we undertook a retrospective review of patients admitted over the past 5 years. Twenty-nine patients with penetrating posterior abdominal wounds were reviewed. There were 17 stab wounds and 12 gunshot wounds. All six patients who exhibited haemodynamic instability or abnormalities on physical examination underwent emergency laparotomy. The remaining 23 patients were admitted for observation. All patients underwent physical examination, abdominal radiographs, and urinalysis. Nine underwent IVP. Eight patients had abdominal CTs. No peritoneal lavages were performed. There were no missed injuries, no deaths and no delayed operations. There were two complications in the operative group, and one liver abscess in the nonoperative group. We conclude that selective management is a safe approach in penetrating posterior abdominal trauma without obvious indications for laparotomy.

Abdominal Injuries↗
PubMed1994

Novel soluble, high-affinity gastrin-releasing peptide binding proteins in Swiss 3T3 fibroblasts.

Swiss 3T3 cells contained substantial amounts of soluble and specific [125I]GRP binders. Like the membrane-associated GRP receptor, they were of high affinity, saturable, bound to GRP(14-27) affinity gels, and exhibited specificity for GRP(14-27) binding. They differed in that acid or freezing destroyed specific binding, specific binding exhibited different time and temperature effects, no detergent was required for their solubilization, ammonium sulfate fractionation yielded different profiles, the M(rs) were lower, GRP(1-16) also blocked binding, and a polyclonal anti-GRP receptor antiserum did not bind on Western blots. The isolated, soluble GRP binding protein(s) rapidly degraded [125I]GRP. These soluble GRP binding proteins may play a role in the regulation of the mitogenic effects of GRP on these cells.

3T3 Cells↗
PubMed1994

The spectrum of blunt injury to the carotid artery: a multicenter perspective.

The relative infrequency of blunt carotid artery trauma prompted a multicenter review to determine the spectrum of injuries, treatment strategies, and neurologic outcome. During a six-year period, 60 carotid artery injuries from blunt mechanisms in 49 patients were treated at 11 institutions. There were 11 bilateral injuries. Injury mechanisms were diverse but involved motor vehicles in 35 (72%) patients. In 14 (29%) patients, significant neurologic deficits developed more than 12 hours after a normal admission neurologic examination. The diagnosis was confirmed by angiography in 42 (86%). Duplex ultrasound accurately demonstrated the arterial injury in 12 (86%) of 14 patients. Documented injuries included arterial thrombosis in 20 arteries, arterial dissection alone in 19, dissection with pseudoaneurysm in six, pseudoaneurysm alone in five, frank arterial disruption in seven, and carotid-cavernous fistula in three. Arterial dissection was managed nonsurgically in 15 (79%) of 19 cases, the majority with systemic anticoagulation. Arterial thrombosis was managed with supportive therapy alone for 16 (80%) of 20 arteries; most associated with fixed neurologic deficits. Pseudoaneurysm repair was performed for six (55%) injuries. Carotid-cavernous fistulas were treated in all three instances with balloon occlusion. Overall mortality was 16 of 49 patients (43%). Good neurologic outcome was achieved in 22 (45%) patients. We conclude that: (1) Neurologic symptoms may develop in a delayed fashion; prior clinical suspicion and diagnostic testing are essential; (2) arterial dissection without complete occlusion may effectively be managed by anticoagulation; (3) pseudoaneurysms in accessible anatomic locations can be repaired with good results; and (4) injuries with complete arterial thrombosis are associated with high mortality and poor neurologic outcome in proportion to the initial degree of neurologic impairment.

Adolescent↗
PubMed1993

Rescue of signaling by a chimeric protein containing the cytoplasmic domain of CD45.

Surface expression of the CD45 tyrosine phosphatase is essential for the T cell antigen receptor (TCR) to couple optimally with its second messenger pathways. CD45 may be required to dephosphorylate a TCR-activated protein tyrosine kinase, which then transduces an activation signal from the TCR. A chimeric molecule that contained extracellular and transmembrane sequences from an allele of a major histocompatibility class I molecule and cytoplasmic sequences of CD45 restored TCR signaling in a CD45-deficient mutant T cell line. Thus, expression of the complex extracellular domain of CD45 is not required for the TCR to couple to its signaling machinery.

Base Sequence↗
PubMed1993

Colostomy in trauma surgery: friend or foe?

Twenty-five patients underwent a colostomy that came to closure. There were eight blunt, 15 penetrating and two impaling injuries. Colostomy-related complications occurred in four patients; two wound infections, one stoma prolapse, one loop obstruction. Closure was performed during a second hospital stay after a standard mechanical bowel preparation and enteral and parenteral broad-spectrum antibiotics perioperatively. The procedure performed by board certified/eligible surgeons, lasted an average of 2.5-3h. Incisional hernias occurred as the only complication in two patients. For certain injuries of the colon, rectum and perineum, diverting colostomy is still the procedure of choice. It can be performed without significant additional morbidity. Subsequent closure in experienced hands does not carry a significant complication rate.

Adolescent↗
PubMed1993

Failure of the legal system to enforce drunk driving legislation effectively.

STUDY OBJECTIVE: To evaluate the investigation and prosecution of drunk drivers and identify reasons for system failure. DESIGN: Prospective data collection on all drivers with an elevated blood alcohol level who were treated at a Level I trauma center between January 1 and June 30, 1991. SETTING: Level I trauma center/university medical center serving a population of 1.8 million. INTERVENTIONS: Prospective data collection, interviewing ambulance squad members, investigating police, and results of prosecution. MEASUREMENTS AND MAIN RESULTS: Of 321 drivers, 78 had ethanol levels of more than 100 mg/dL; nine were between 50 and 100 mg/dL. All drivers had rapid transport to a trauma center for severe injury or high-risk injury mechanism. Police reports were accessible for 84 of 87 drivers; all drivers were believed to be at fault. The crashes resulted in five deaths and 74 other victims requiring hospitalization. Six of the intoxicated drivers died. Police requests for blood alcohol levels were made for 28 drivers, one of whom died. The remaining 59 drivers had no legal blood alcohol level drawn. Although the greater the distance from our center (more rural), the less likely were requests for ethanol levels, but there were many "no requests" from nearby cities. Of the 28 drivers on whom legal alcohol levels were drawn, eight escaped central registration with the highway safety commission, which records any and every traffic violation within New Jersey. Of the remaining 20, eight were not prosecuted (excluding one death), including one repeat offender. One committed a later "driving while intoxicated" offense and was then prosecuted. The remaining 11 were all convicted; five were repeat offenders. CONCLUSION: Reasonable cause is required for legal blood alcohol requests. Our data demonstrated that this is difficult when the driver is unavailable for questioning. However, once legal blood alcohol levels have been obtained, inadequate legal follow-up leads to nonprosecution. Once officially charged, conviction appears certain, but even this punishment and re-education fail to change behavior in many of these drivers.

Accidents, Traffic↗