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Biomedical subjects

S E Ross

Publications and source records attributed to S E Ross.

At least 109 records · Page 6Linked to original sources

Electrophoretic characterization of chromosomal DNA from two microsporidia.

Spores of two microsporidia, Nosema pyrausta (from the European corn borer, Ostrinia nubilalis) and N. furnacalis (from the Asian corn borer, O. furnacalis) were harvested from laboratory-reared O. nubilalis caterpillars and purified by centrifugation through Percoll. Conditions permitting in vitro germination were defined for both species and found to be different. N. pyrausta spores were incubated in 0.1 N KOH for 30 min, recovered by centrifugation, and resuspended in 1 ml of an equal mixture of 1% low melting point (LMP) agarose and L-15B medium at 37 degrees C to induce germination. N. furnacalis spores were first washed in 10 mM Na2EDTA in 1 mM Tris base, pH 7.5, exposed to 0.01 N KOH in 0.17 M KCl for 30 min, centrifuged, and germinated in 1 ml of an equal mixture of 1% LMP agarose and 0.17 M KCl in 10 mM Na2EDTA (pH 8), at 37 degrees C. Eighty to 90% of the spores of each species germinated. Germinated spores were pipetted into a casting mold. Before electrophoresis, agarose blocks were incubated 48 hr at 50 degrees C in 10 mM Tris base/100 mM Na2EDTA, pH 7.8, with 1 mg/ml proteinase K and 1% N-laurylsarcosine to release the chromosomal DNA from sporoplasms. After pulsed-field electrophoresis, ethidium bromide staining revealed 13 chromosomal bands ranging in size from 1390- to 440-kb pairs and 1360- to 440-kb pairs in N. pyrausta and N. furnacalis, respectively. The difference in size estimates of corresponding chromosomes in the two species was not more than 60-kb pairs.

Animals↗

Pulmonary embolism in major trauma patients.

In a 1-year retrospective review, 30 pulmonary emboli were diagnosed among 1,316 trauma patients who survived for at least 24 hours after admission to a Level I trauma center. Pelvic fractures, age over 55 years, severe single or multiple system trauma, and cannulation of central veins all appear to place injured patients at increased risk. Long bone fractures were not associated with an increased risk. The majority of pulmonary emboli were diagnosed during the first week of hospitalization with some as early as 24 hours and none later than 15 days postinjury. Although the etiology of these early emboli is uncertain, prolonged immobilization does not appear to play a role in placing these patients at increased risk for thromboembolic events. Pulmonary embolism should be suspected in any injured patient with respiratory compromise, and an aggressive approach to diagnosis is warranted.

Adult↗

Impact of a required request law on vital organ procurement.

"Mandatory" or required request for donation of the organs of patients dying in hospitals has been promulgated as a means of increasing the rate of organ harvest and alleviating the critical shortage of transplantable organs. Although the federal and many state governments have passed legislation to make such requests compulsory, the efficacy of this approach has not been demonstrated. Examination of the experience at our trauma center and in this region, before and after the enactment of a "strong" required request law by the State of New Jersey, did not reveal a statistically significant change in organ procurement. We conclude that such laws are unlikely to achieve the desired result in the absence of fundamental changes in the attitudes of the public and treating physicians.

Age Factors↗

Conservative management of duodenal trauma: a multicenter perspective.

The experience of eight trauma centers with duodenal injuries was analyzed to identify trends in operative management, sources of duodenal-related morbidity, and causes of mortality. During the 5-year period ending December 1988, 164 duodenal injuries were identified. Patient ages ranged from 5 to 78 years. There were 38 Class I, 70 Class II, 48 Class III, four Class IV, and four Class V injuries. Injury mechanism was penetrating in 102 (62%) patients and blunt in 62. Primary repair of the duodenal injury was performed in 117 (71%) patients, including 27 patients also managed with pyloric exclusion and 12 with tube duodenostomy. Duodenal resection with primary anastomosis was used in six (4%) patients and pancreatoduodenectomy was necessary in five (3%). There were 30 (18%) deaths. The cause of death was uncontrolled hemorrhage from severe hepatic or vascular injuries in 22 (73%) patients. In only two (1%) patients could death be attributed to the duodenal injury; each as the result of duodenal repair dehiscence and subsequent sepsis. Duodenal-related morbidity was documented in 29 (18%) patients, including 22 patients with intra-abdominal abscess, six with duodenal fistula, and five with frank duodenal dehiscence. In summary, this analysis demonstrated: 1) the great majority of duodenal injuries can be managed by simple repair; 2) tube duodenostomy is not a mandatory component of operative treatment; 3) pyloric exclusion is a useful adjunct for more complex injuries; 4) pancreatoduodenectomy is rarely necessary for civilian duodenal trauma; 5) morbidity following duodenal trauma is more dependent on associated intra-abdominal injuries than the extent of duodenal trauma; and 6) mortality following duodenal injuries is primarily related to associated vascular and hepatic trauma.

Abdominal Injuries↗

Dynamic computerized tomography of the occiput-atlas-axis complex in trauma patients with odontoid lateral mass asymmetry.

Over a 23-month period, 25 patients aged 11 to 74 years presented to our Level I trauma center with odontoid lateral mass asymmetry of 2 to 5 mm on properly centered AP open-mouth X-rays: 32% of patients were asymptomatic, 68% had cervical pain, and 32% had limited range of motion. Patients with cervical spine fractures or dislocations and those with fixed deformity were excluded. The clinical significance of asymmetry was determined utilizing dynamic axial CT scanning of the occiput (C0), atlas (C1) and axis (C2) with the head neutral and with 15 degrees to 30 degrees active rotation. Nineteen patients demonstrated greater than 5 degrees of relative motion of C1 on C2 bilaterally. Three patients had less than 5 degrees of relative motion bilaterally and three patients had less than 5 degrees relative motion with left rotation only. No patient had formal treatment and all had nearly normal cervical range of motion on clinical examination at the time of hospital discharge. The finding of an asymmetric odontoid-lateral mass interspace on properly centered open-mouth AP X-rays in the presence of otherwise normal cervical spine X-rays, in conscious patients without fixed deformity, appears to be incidental and requires no further evaluation or treatment.

Adolescent↗

The value of computed tomographic scans in patients with low-risk head injuries.

The determination that a particular head injury is "mild" or "low-risk" is usually made on clinical grounds. Observation at home or in the hospital has been the usual treatment for such patients. A recent report of excessive mortality among these patients with low-risk head injuries in some hospital settings suggests the need for improvement in diagnostic criteria. Our study included 658 patients admitted to Cooper Hospital for a mild head injury, who had a Glasgow Coma Scale score of 13 to 15 on admission, and who experienced a brief loss of consciousness or amnesia after the injury. Their records and cranial computed tomographic (CT) scans on admission were reviewed to determine their subsequent course. In 18% of patients abnormalities were seen on the initial CT scan and 5% required surgery. Among the 62 patients with a Glasgow Coma Scale score of 13, 40% had abnormalities on the CT scan and 10% required surgery. None of the 542 patients with normal CT scans on admission showed subsequent deterioration and none needed surgery. These figures suggest that history and physical examination alone are not adequate to assess head injury or severity of risk and that the addition of a CT scan greatly improves patient assessment. Abnormalities on CT scans are so common in patients with a Glasgow Coma Scale score of 13 that head injuries in these patients should be classified as "moderate" rather than "mild" in severity and risk. Patients with normal CT scans should be considered for observation at home, allowing hospital personnel to devote full attention to the more seriously injured patients.

Brain Injuries↗

Blunt aortic trauma following deceleration in a seven year old.

Aortic injury following deceleration is an uncommon clinical entity in the pediatric population. Flexibility of the thoracic cage and marked tissue elasticity have been hypothesized as critical factors. Unfortunately, the scarcity of this phenomenon can lead to a lowered suspicion. We describe a case of blunt aortic injury following deceleration to raise the index of suspicion for this injury in the pediatric population.

Accidents, Traffic↗

Traumatic disruptions of the thoracic aorta: treatment and outcome.

Of 27 patients admitted to our level I trauma center with acute disruption of the thoracic aorta, two patients died of exsanguination before aortic repair. One patient had massive leakage from the aneurysm after aortography and died during surgery. All patients suffered from multiple injuries. Eighty-three percent of the patients had major operations in addition to the aortic repair. "Clamp and sew" technique was used in 18 patients (75%), two of whom had multiple tears of the aortic arch. Heparin-coated shunts were used in five patients (20.8%), and a cardiopulmonary bypass was performed in one patient who had multiple tears. Three postoperative deaths were related to polytrauma, cardiogenic shock, and sepsis. Paraplegia developed in three patients, two of whom had multiple aortic lesions necessitating longer ischemia time during the repair. Only one patient had complete neurologic deficit at the 1-year follow-up. In our series, neither surgical procedure proved superior. We conclude that the "clamp and sew" technique for repair of the disrupted thoracic aorta may allow for a more favorable outcome.

Adult↗

Interpretation of the cervical spine X-ray: a simplified approach.

Because many nursing interventions require mobilization of the patient, cervical spine film interpretation should be a necessary tool of the critical care nurse. This article provides the fundamentals necessary for initial interpretation of the cervical spine, plus a review of the common radiographic views of the cervical spine, abnormalities, and a systematic approach to the interpretation of these studies.

Cervical Vertebrae↗

Injury severity scoring: a comparison of early clinical versus discharge diagnosis.

The Abbreviated Injury Scale (AIS) and the Injury Severity Score (ISS) are objective means of assessing injury. Accepted methodology involves retrospective scoring of injury based on discharge diagnoses. Recently, early clinical scoring, supplemented by review at discharge, has been introduced. A prospective study was instituted to compare these methodologies. Four hundred sixty consecutive victims of blunt trauma were scored using both clinical and retrospective methodologies by independent, blinded observers. Of these, 333 patients had a change in ISS, 174 with a change of greater than four points. The population mean ISS remained unchanged; however, paired values were significantly different (p less than .03). We conclude that either methodology is applicable for studies of large populations of trauma victims. When accurate individual AIS or ISS scoring is required, the clinical method combined with discharge review is most appropriate.

Accidents, Traffic↗

Computed tomography in the initial evaluation of the cervical spine.

Unstable injury of the cervical spine must be considered in all victims of blunt trauma. To evaluate the role of limited, directed computed tomography (CT) in the initial evaluation of the cervical spine, a one-year study involving 104 high-risk patients was undertaken. Sensitivity was 0.78 overall, but in the group of patients scanned after inadequate plain radiographs, CT had a sensitivity of 1.0 for unstable cervical injury. All false-negative studies involved atlantoaxial rotary subluxation. We conclude that limited, directed CT of the cervical spine is appropriate in the initial evaluation of patients at risk, particularly if plain radiographs are inadequate, but is of limited value in the evaluation of ligamentous injury of the upper cervical spine.

Adolescent↗

Delayed identification of skeletal injury in multisystem trauma: the 'missed' fracture.

Delay in diagnosis of musculoskeletal injury in multiply injured patients may potentially lead to functional or cosmetic disability in survivors. In an 18-month prospective study to determine the incidence and spectrum of delayed recognition of skeletal injury at our Level I trauma center, delayed diagnosis of 39 fractures was made in 26 of 1,006 consecutive blunt trauma patients. The delay in recognition ranged from 1-91 days. Twenty-one (55%) of the fractures were not X-rayed at the time of admission, but nine (23%) fractures were clearly visible on admission films. Four (10%) fractures were missed because of technically inadequate X-rays, and five (13%) had adequate X-rays but could not be identified on admission films. In only two instances was a second anesthetic exposure required for operative therapy. For the patients in this series, the delay of fracture identification was not felt to contribute to additional long-term cosmetic, functional, or neurologic problems. Continued clinical and radiologic surveillance is required in multiply injured patients to prevent musculoskeletal diagnostic failure.

Adolescent↗

Recruiting and retaining competent clinical nurses. The Clinical Promotion Project Victoria General Hospital, Halifax, Nova Scotia.

A career advancement program for nurses has been developed and implemented at the Victoria General Hospital, Halifax, as part of a manpower planning strategy for recruitment and retention of clinical nurses. A competency based performance appraisal system was developed and implemented as part of the program. This system identifies four levels of clinical expertise. Progression through each level indicates that a nurse has achieved a certain level of skill, knowledge and abilities. Demonstrated competence in one level is a prerequisite to promotion to the next level of practice. Implementation of this system provides clinical career opportunities for nurses in direct patient care. This article will provide the nurse administrator with an insight into the development and implementation of a clinical career advancement program. Future articles will described the research evaluation of the Clinical Performance Appraisal System and clinical nurses' reactions to the new system.

Career Mobility↗

Effects of lipid-binding proteins apo A-I, apo A-IL, beta 2-glycoprotein I, and C-reactive protein on activation of factor X by tissue factor--factor VIIa.

Tissue factor is the membrane-associated protein which mediates activation of factors IX and X by factor VII. In a purified, reconstituted bovine system, factor X activation by the tissue factor-factor VIIa complex is inhibited by the mixed apoproteins from human high density lipoprotein (HDL) and by isolated apolipo-protein A-II (apo A-II). Other proteins found associated with plasma lipoproteins, apolipoprotein A-I (apo A-I), C-reactive protein (CRP), and beta 2-glycoprotein I (beta 2 GPI), have been examined for effects on the activation of factor X by tissue factor-factor VIIa. In these experiments, bovine tissue factor, reconstituted into phosphatidylserine-phosphatidylcholine (PS/PC; 30/70) vesicles, was used at a single concentration while factor X (the substrate), factor VIIa (the enzyme), and the potentially inhibitory proteins were varied in a continuous chromogenic assay. Apo A-II and CRP clearly inhibit tissue factor-factor VIIa activation of factor X, while apo A-I and beta 2 GPI have little or no effect. These results demonstrate that different lipid binding proteins vary in their effects on tissue factor activity.

Apolipoprotein A-I↗

Routine pelvic radiography in severe blunt trauma: is it necessary?

To evaluate the hypothesis that all victims of severe blunt trauma require a pelvic radiograph, we prospectively studied all such patients admitted to the Southern New Jersey Regional Trauma Center during a seven-month period. All patients were classified as unconscious; impaired; awake, alert, and symptomatic; or alert, oriented, and asymptomatic for pelvic fracture on admission. All underwent a plain anterior-posterior radiograph of the pelvis. A total of 265 patients were studied and 26 pelvic fractures were identified. These occurred in seven of 36 unconscious patients, 11 of 96 impaired patients, and eight of 23 symptomatic patients. No fractures were identified in 110 awake, alert, oriented, and asymptomatic patients (P less than .0001). We conclude that pelvic radiographs are required in unconscious or impaired victims of severe blunt trauma and those with signs or symptoms of pelvic fractures but are not required in the awake, alert, and asymptomatic patient.

Adult↗

The incidence of injury to the cervical spine in patients with craniocerebral injury.

Estimates of the incidence of injury to the cervical spine among patients suffering blunt trauma to the head vary widely, and have been reported to be as high as 20%. Since strict observation of cervical spine precautions may delay attempts to gain control of the airway in a patient with an intracranial injury, the risk involved needs more exact definition. In an attempt to quantify this risk, the records of 1,272 consecutive patients with blunt injuries admitted to a Level I regional trauma center were reviewed. Patients with serious craniocerebral injury were at no greater risk for injury to the cervical spine than patients without trauma to the head (1.8% vs. 3.5%, p = NS by Chi-square analysis). Although observance of cervical spine precautions is usually paramount, there may be times when this concern is superceded by the need to gain definitive airway control in a patient with injury to the brain.

Adult↗