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Biomedical subjects

R A Cowley

Publications and source records attributed to R A Cowley.

At least 19 recordsLinked to original sources
PubMed2001

Multiparticle states in the S = 1 chain system CsNiCl3.

A continuum of magnetic states has been observed by neutron scattering from the spin-1 chain compound CsNiCl3 in its disordered gapped one-dimensional phase. Results using both triple-axis and time-of-flight spectrometers show that around the antiferromagnetic point Qc = pi, the continuum lies higher in energy than the Haldane gapped excitations. At 6 K the integrated intensity of the continuum is about 12(2)% of the total spectral weight. This result is considerably larger than the 1%-3% weight predicted by the nonlinear sigma model for the three-particle continuum.

Journal Article↗
PubMed1992

Trauma center closures: a national assessment.

A 1990 national survey of 66 closed trauma centers across 14 states was conducted to ascertain the factors that prompted closure. Data from 44 facilities, or 67% of the centers identified, indicate that inadequate financing and physician participation were commonplace. The findings support the work of other investigators and demonstrate that uncompensated care, inadequate reimbursement, high operating costs, and lack of physician support all adversely affect trauma care in both urban and suburban settings.

Catchment Area, Health↗
PubMed1991

Seatbelt effectiveness and cost of noncompliance among drivers admitted to a trauma center.

Enactment of seatbelt legislation in Maryland presented the opportunity to compare seatbelt compliance among seriously injured drivers admitted to a Level I trauma center and to establish levels of severity, length of stay, and hospital cost differences among the study population. Fifty-five randomly selected drivers were examined from a total surgical population of 689. Seatbelt compliance rate was 41.8%, reflecting the rate in the community. Seatbelts reduced the total number of injuries by 34%, major injuries by 57%, and minor injuries by 20%. No deaths occurred among the belted group. The unbelted group had a mean Injury Severity Score two times as great as the belted group and were hospitalized 1.6 times longer at double the cost. Major injuries to the face, chest, and pelvic regions were prevented by the seatbelt. Among the belted group, severe injuries did occur to the head, neck, and abdominal regions. It is recommended that both air bags and automatic restraining devices be required for all drivers if the trauma occurring daily on highways is to be eliminated and acute hospital cost minimized.

Accidents, Traffic↗
PubMed1991

Blunt traumatic rupture of the heart and pericardium: a ten-year experience (1979-1989).

Blunt traumatic rupture of the heart and pericardium, rarely diagnosed preoperatively, carries a high mortality rate. From 1979 to 1989, more than 20,000 patients were admitted to a Level I trauma center. A retrospective review identified 59 patients requiring emergency surgery for this condition. Injuries resulted from vehicular accidents (68%), motorcycle crashes (10%), pedestrians being struck by vehicles (7%), falls (5%), crushing (7%), and being struck by a horse (2%) or crane (2%). Seventeen patients (29%) had isolated rupture of the pericardium; 37 (63%) had ruptures of one or more cardiac chambers. All patients had signs of life at the scene or during transportation, but only 29 (49%) had vital signs on admission: 15 with chamber injury, 12 with pericardial rupture, and two with combined injuries. Diagnosis was established by emergency thoracotomy in the 30 patients who arrived in cardiac arrest. In the remaining 29 patients, diagnosis was made by urgent thoracotomy (41%), by subxiphoid pericardial window (34%), during laparotomy (21%), or by chest radiography (3%). The overall mortality rate was 76% (45 patients), but only 52% for those with vital signs on admission. Rapid transportation and expeditious surgical treatment can save many patients with these injuries.

Adolescent↗
PubMed1990

Rupture of thoracic aorta caused by blunt trauma. A fifteen-year experience.

During the 15 years from 1971 through 1985, 114 patients with rupture of the thoracic aorta caused by blunt trauma were admitted to the Shock Trauma Center of the Maryland Institute for Emergency Medical Services Systems. Mean age was 31.3 years (range, 15 to 80). Ninety were male and 24 were female, a 3.75:1 ratio. Of the 114, 89 (78.1%) survived initial resuscitation in the admitting area. Twenty five of the 89 initial survivors (28.1%) died during or after surgical repair. Paraplegia occurred in 11 of the 78 operating room survivors (14.1%). Further analysis was done of the 83 patients admitted in the 10-year period from 1976 through 1985. Mean Injury Severity Score, excluding aortic injury, was 18.2. Twenty-five of the 83 (30.1%) died during resuscitation in the admitting area or operating room. Seven others died during surgical repair and 12 died postoperatively, leaving 39 survivors (39/83 [47%] of total admissions and 39/58 [67.2%] of survivors of resuscitation). Paraplegia/paresis developed postoperatively in six of 34 (17.6%) cases involving shunt and four of 17 (23.5%) without shunt. Other major complications occurred in 21 of the operating room survivors. Statistically significant risk of death or major complication was associated with female sex, higher Injury Severity Score, lower admission blood pressure, larger hemothorax on admission, less qualified surgeon, major operation before aortic repair, use of shunt, and transfer directly from scene of injury. There was no advantage in this series to using or not using a shunt in preventing paraplegia. Mortality rates are realistic for a highly developed trauma system. Better techniques are needed to manage exsanguination and prevent paraplegia.

Adolescent↗
PubMed1989

Blunt chest trauma in the elderly.

Significant differences were identified between a group of elderly patients (65 years and older) and a nonelderly group both with blunt thoracic trauma. There was a lower incidence of elderly patients presenting in shock; however, cardiopulmonary arrest at arrival was more frequent in this group. Although the types of complications were similar in both populations, the morbidity and mortality rates were higher in the elderly. A high index of suspicion must be generated for an elderly patient who has sustained blunt chest trauma. An aggressive diagnostic and therapeutic approach may lead to a decrease in the high morbidity and mortality rates in the elderly.

Age Factors↗
PubMed1989

HIV infection rates in a trauma center treating predominantly rural blunt trauma victims.

Human immunodeficiency virus (HIV) infection rates among 1,497 consecutive adult trauma victims triaged from rural and urban sectors to a statewide trauma center in Baltimore were studied. Those studied were 71.7% men, 77.4% whites, 63.2% vehicular trauma victims, 11.2% assault victims, and 25.7% other trauma victims. Non-Baltimoreans predominated (86.0%) and 32.7% were 25 to 39 years of age. Overall, 1.67% of the victims were HIV antibody positive. Significantly higher infection rates were seen in men (1.96% vs. 0.95%; p less than 0.02), non-whites (4.13% vs. 0.95; p less than 0.005), assault victims compared with vehicular and other trauma victims (5.99% vs. 1.06% vs. 1.30%, respectively; p less than 0.001), and Baltimore City residents (3.81% vs. 1.32%; p less than 0.03). Among those 25 to 39 years of age, 68.0% of the HIV infections were noted. Results suggest that HIV infection rates among trauma center patients are a reflection of the patient population served.

Adolescent↗
PubMed1988

Marijuana and alcohol use among 1023 trauma patients. A prospective study.

Marijuana use prior to injury was determined prospectively in 1023 patients injured as the result of vehicular (67.6%) and nonvehicular (32.4%) trauma. Most were men (72.8%); most were 30 years of age or younger (58.4%). All were admitted directly from the scene of injury. Serum delta-9-tetrahydrocannabinol activity was ascertained using a radioimmunoassay. Activity of 2 ng/mL or more was detected in 34.7% of subjects. Blood alcohol determinations were made in 1006 patients; 33.5% were positive. Marijuana use among vehicular and nonvehicular trauma victims was not significantly different. Marijuana use was higher among those 30 years of age or younger and among men. Vehicular crash victims consumed alcohol more frequently. Use of marijuana and alcohol in combination (16.5%) was highly significant compared with marijuana alone (18.3%), alcohol alone (16.1%), or neither drug (49.1%).

Accidents↗
PubMed1987

A national alcohol and trauma center survey. Missed opportunities, failures of responsibility.

The results of a national survey of trauma centers concerning their assessment and response to the problem of alcohol and trauma are reported. Surveys were returned from 154 trauma centers located in 43 states and the District of Columbia. The profile of the 125,000 patients treated at the centers is a 30-year-old man sustaining blunt trauma, usually in a vehicular crash. Two-thirds of centers estimated that the majority of their patients had abused alcohol. While acknowledging alcohol as a significant cause of trauma, only 55.2% of centers routinely obtain admitting blood alcohol levels. Less than a third of the centers employ alcoholism counselors. Most trauma centers are not providing services that allow them to fulfill their responsibility to detect and initiate treatment of alcohol abuse, a major cause of traumatic injury.

Accidents, Traffic↗
PubMed1987

Pathophysiology of acute renal failure following living Escherichia coli injection in rats: high-energy metabolism and renal functions.

The energy metabolism of kidney and renal function were studied in rats following an IV injection of living Escherichia coli. Energy charge (ATP + 0.5 ADP/ATP + ADP + AMP) decreased throughout the period studied. Total and ouabain-sensitive Na-K ATPase activity of renal cortex homogenate decreased markedly at 3 hr followed by gradual recovery. Polyulia was seen at 3 and 6 hr followed by oliguria at 12 hr after E. coli injection. PSP excretion test showed a marked decrease throughout the time course. In contrast, creatinine clearance decreased only at 12 hr. From these results, it was clarified that the renal insufficiency following bacteremia occurs in two different stages; the early stage with a high urinary output accompanied by decreased Na-K ATPase activity suggesting deterioration of proximal tubular functions and the late stage with oliguria in which glomerular filtration is severely depressed. In both stages, renal energy metabolism is markedly disturbed.

Acute Kidney Injury↗
PubMed1986

Orotracheal intubation in suspected laryngeal injuries.

Airway control in patients with suspected laryngotracheal injury following blunt trauma is a challenging problem. Tracheostomy remains the treatment of choice in most instances. This report describes a patient with a laryngotracheal injury in whom initial airway control was achieved using orotracheal intubation. The indications for this method are discussed, and an approach to initial airway management in these injuries is outlined.

Adult↗
PubMed1986

Massive transfusion without major complications after trauma.

A case of massive degloving injury of the trunk, with open pelvic fracture, and evisceration of abdominal contents from blunt trauma is presented. The most significant aspect of this case was the transfusion of 173 units of packed cells and 176 units of fresh frozen plasma in the first thirty hours. The patient ultimately recovered and returned to work.

Abdominal Injuries↗
PubMed1984

Metabolic studies of postischemic acute renal failure in the rat.

Postischemic acute renal failure was induced by 1 hr of clamping of the renal vasculature. Adenine nucleotide (ATP, ADP, AMP) and lactate (Lac) levels were measured after 0, 0.25, 1, 6, 24, and 48 hr of reflow to determine the time necessary for recovery to control levels. After 1 hr of ischemia with no reflow, [ATP] was 18% and [Lac] was 10-fold control levels. Control levels were restored after 24 hr of reflow. Variable ischemic times (5, 15, 30, 60, 90, and 120 min) followed by (1) no reflow or (2) 24 hr of reflow were also studied. [ATP] decreased to 25 and 13% of controls after 5 and 120 min of ischemia, respectively, and [Lac] increased to 5- and 13-fold controls after 5 and 120 min. Five to ninety minutes of ischemia followed by 24 hr of reflow resulted in a trend toward restoration of ATP and Lac levels; whereas, 120 min of ischemia followed by 24 hr of reflow resulted in death. The results indicate that: (1) In vivo ischemia results in a drastic and rapid shift in the ATP-ADP-AMP equilibrium; (2) the absolute concentration of ATP is not a reliable criterion of cell viability, but the ability to resynthesize ATP may be determinant in the reversibility of the lesion; (3) 1 hr of ischemia is reversible with respect to restoration of [ATP] and [Lac], but 24 hr of reflow are needed for restoration; and (4) ischemia for 90 min results in a metabolic derangement which is partially reversible in that metabolite levels are partially restored after 24 hr of reflow. However, 90 min of vascular clamping is not functionally reversible since the majority of animals exhibit severe azotemia and do not survive.

Acute Kidney Injury↗