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Biomedical subjects

S Ross

Publications and source records attributed to S Ross.

At least 127 records · Page 7Linked to original sources
PubMed1996

Interleukin-1 receptor antagonist: characterisation of its gene expression in rabbit tissues and large-scale expression in eucaryotic cells using a baculovirus expression system.

The gene expression of rabbit interleukin-1 receptor antagonist (RbIL-lra) was examined in rabbit tissues. RNA was isolated from heart, lung, kidney, muscle, liver, spleen, brain, and peripheral blood monocytes (PBMs), and RbIL-lra mRNA was identified as a single species by Northern analysis using a RbIL-lra probe. RbIL-lra was abundantly expressed in lung, brain, heart, and liver, expressed at low levels in spleen, and undetectable in kidney and unstimulated PBMs. Expression of large scale recombinant production of RbIL-lra was achieved by subcloning the cDNA into a baculovirus expression vector. Recombination of this vector was completed with the BacPAK6 baculovirus genome. The recombinant virus, containing the RbIL-lra cDNA, was used to infect Spodoptera frugiperda (Sf21) insect cells in a spinner flask system and in monolayers in cell culture flasks. Recombinant rabbit IL-lra (rRbIL-lra) was secreted into the culture medium in this system at very high levels (35 mg/l). The protein was identified by reducing SDS-PAGE electrophoresis, was variably glycosylated and had a molecular weight between 19-25 kDa. It was then purified by size exclusion HPLC on a Du Pont Gf-250 column. The rRbIL-lra was demonstrated to be functionally active by inhibiting recombinant human IL-1 alpha in a mouse thymocyte proliferation assay. 20 ng/ml (6.7 U/ml) of rRbIL-lra inhibited 95% of the activity of 2 ng/ml IL-1 alpha.

Animals↗
PubMed1996

Association of radionuclide bone scan and serum alkaline phosphatase in patients with metastatic renal cell carcinoma.

OBJECTIVES: We assessed the frequency of bone metastases, their association with serum alkaline phosphatase (AP), and prognostic capabilities of AP in patients with renal cell carcinoma (RCC), using bone scan as the reference standard for diagnosis. METHODS: We conducted a retrospective review of patients with metastatic RCC treated with either autologous ex vivo activated T-lymphocytes and cimetidine (ALT) or cimetidine alone. RESULTS: Twenty-eight of 90 patients (31%) had evidence of bone metastases by bone scan. With 100 mg/ dL as the upper limit of normal, 11 of 28 (39%) patients with bone metastases had normal AP levels. Of these 11 patients, 8 had bone pain. Of the 3 asymptomatic patients with bone metastasis and normal AP levels, only 1 had bone as the only site of metastasis and would have been incorrectly staged without the scan. Patients with bone metastases had a significantly shorter median survival than those without bone metastases (13.8 versus 25.3 months; P < 0.05). Among patients without bone metastases who had elevated AP levels, those treated with ALT had significantly longer median survivals than those treated with cimetidine alone (27.6 versus 14.5 months; P < 0.05). Overall, patients treated with ALT had a significantly longer median survival than the ones treated only with cimetidine (21 versus 8.5 months; P < 0.05). Overall, the median survival for patients with elevated AP levels (10 months) was not significantly different from that of those with normal AP levels (13 months). CONCLUSIONS: In a high-risk group of patients with metastatic RCC, 31% had bone metastases. Elevated AP levels, the presence of bone pain, or the presence of other metastases correctly predicted bone metastasis in all but 1 patient. A bone scan may safely be omitted in patients with RCC, normal AP levels, and no bone pain. However, AP elevation itself had little prognostic capability in these patients.

Alkaline Phosphatase↗
PubMed1996

An unusual case of spinal metastasis from a liposarcoma.

A 58-year-old man presented with spinal cord compression due to a metastatic liposarcoma of the thoracic spine. There was no evidence of vertebral bone involvement radiographically. This rare case is presented and its clinical features and diagnosis are discussed.

Epidural Neoplasms↗
PubMed1996

Severe systemic cholesterol embolization after open heart surgery.

Cholesterol crystal embolization (CCE) may be triggered by various factors: intra-arterial angiographic procedures, aortic or vascular surgery, anticoagulant or thrombolytic treatments, or both. There are few previous reports of patients undergoing coronary artery bypass grafting (CABG) experiencing and therefore displaying severe systemic CCE. We describe four patients presenting, shortly after CABG, cutaneous, renal, neurological and hepatic signs related to severe CCE confirmed by skin biopsy. All patients died 11-92 days after surgery. As systemic CCE reveals severe atheromatous disease and is associated with a poor prognosis, it is advisable to avoid CABG in patients who present symptoms of CCE before surgery.

Aged↗
PubMed1996

Status of nonoperative management of blunt hepatic injuries in 1995: a multicenter experience with 404 patients.

INTRODUCTION: Nonoperative management is presently considered the treatment modality of choice in over 50% of adult patients sustaining blunt hepatic trauma who meet inclusion criteria. A multicenter study was retrospectively undertaken to assess whether the combined experiences at level I trauma centers could validate the currently reported high success rate, low morbidity, and virtually nonexistent mortality associated with this approach. Thirteen level I trauma centers accrued 404 adult patients sustaining blunt hepatic injuries managed nonoperatively over the last 5 years. Seventy-two percent of the injuries resulted from motor vehicle crashes. The mean injury severity score for the entire group was 20.2 (range, 4-75), and the American Association for the Surgery of Trauma-computerized axial tomography scan grading was as follows: grade I, 19% (n = 76); grade II, 31% (n = 124); grade III, 36% (n = 146); grade IV, 10% (n = 42); and grade V, 4% (n = 16). There were 27 deaths (7%) in the series, with 59% directly related to head trauma. Only two deaths (0.4%) could be attributed to hepatic injury. Twenty-one (5%) complications were documented, with the most common being hemorrhage, occurring in 14 (3.5%). Only 3 (0.7%) of these 14 patients required surgical intervention, 6 were treated by transfusions alone (0.5 to 5 U), 4 underwent angio-embolization, and 1 was further observed. Other complications included 2 bilomas and 3 perihepatic abscesses (all drained percutaneously). Two small bowel injuries were initially missed (0.5%), and diagnosed 2 and 3 days after admission. Overall, 6 patients required operative intervention: 3 for hemorrhage, 2 for missed enteric injuries, and 1 for persistent sepsis after unsuccessful percutaneous drainage. Average length of stay was 13 days. Nonoperative management of blunt hepatic injuries is clearly the treatment modality of choice in hemodynamically stable patients, irrespective of grade of injury or degree of hemoperitoneum. Current data would suggest that 50 to 80% (47% in this series) of all adult patients with blunt hepatic injuries are candidates for this form of therapy. Exactly 98.5% of patients analyzed in this study successfully avoided operative intervention. Bleeding complications are infrequently encountered (3.5%) and can often be managed nonoperatively. Although grades IV and V injuries composed 14% of the series, they represented 66.6% of the patients requiring operative intervention and thus merit constant re-evaluation and close observation in critical care units. The optimal time for follow-up computerized axial tomography scanning seems to be within 7 to 10 days after injury.

Adolescent↗
PubMed1996

A functional model of the hair cell-primary fiber complex.

A model is proposed containing three parallel systems; system 1 is a single channel consisting of an inhibitory circuit being fed by a fixed permeability responsible for spontaneous activity in parallel with a displacement-driven permeability, while systems 2 and 3 each consist of a number of identical permeability-volume-permeability channels with on/off switches activated at levels specific for each channel. The (continuous) output of each system drives a Poisson generator whose output "events" are delivered to a firing mechanism in the form of a "leaky integrator" delivering actual "firings" in simulated real time. The model quite accurately reproduces (1) stimulation and recovery phases of PST histograms obtained at six levels of stimulation for six auditory fibers (including "dead" period after stimulation), (2) single-exponential functions of recovery from adaptation for both onset and steady-state part of probe tone, (3) increments in response as independent of time of application of stimulus increment, (4) a specified hazard function for firings, (5) interval histograms of driven activity, (6) loss of phase locking with increasing frequency of stimulation, and (7) extended dynamic range for onset of response. The model fails in reproducing specific characteristics for response to decrements, and for response to AM.

Animals↗
PubMed1996

The usefulness of transesophageal echocardiography in diagnosing cardiac contusions.

OBJECTIVES: To assess the usefulness of transesophageal echocardiography in diagnosing cardiac contusions in patients with blunt trauma. BACKGROUND: For more than a decade, noninvasive tests, including ECGs, cardiac enzymes, nuclear studies, and transthoracic echocardiography have been utilized in an attempt to identify trauma patients with cardiac injuries. These tests have been imperfect in identifying the patients at high risk for mortality. METHODS: We retrospectively reviewed the charts in 22 patients with transesophageal echocardiographically diagnosed cardiac contusions noting age, race, sex, transthoracic echocardiographic examinations, study quality, and outcome. We also noted the Injury Severity Score, which is a measure of the severity of illness in trauma patients. Higher scores correlate more severe injury and higher mortality. We defined cardiac contusions as presence of wall motion abnormality, including either or both ventricles, in the absence of transmural myocardial infarction on ECG following nonpenetrating chest trauma. RESULTS: Over a 30-month period, 81 transesophageal echocardiographic examinations were performed on trauma patients. Among this group, 22 patients were diagnosed as having cardiac contusions. There were 15 patients with right ventricular contusions, 7 patients with left ventricular contusions, and 2 patients with both ventricles involved. We compared this group with all ICU trauma patients admitted to the hospital during this time period. Overall, the contusion patients had an average Injury Severity Score of 27 and a mortality of 27% compared with the overall trauma group with an Injury Severity Score of 33 and a corresponding mortality of 9% (p < 0.001). Corresponding ECGs were nondiagnostic in 73% of patients with cardiac contusion. There were no complications related to the transesophageal examinations. CONCLUSIONS: Transesophageal echocardiographically diagnosed cardiac contusion in trauma patients carries a high mortality rate. Transesophageal examinations are safe and provide excellent quality images where transthoracic examinations were inadequate. Right ventricular contusions are approximately twice as common as left ventricular contusions.

Adolescent↗
PubMed1995

Pharmacokinetic and therapeutic outcome in melanoma cells, of the administration of symmetric and asymmetric cationic photosensitizers.

The response of melanoma cell lines to a range of novel cationic photosensitizers based on either a protoporphyrin or a mesotetra(4-carboxylphenyl)porphine molecule, has been examined. The drugs varied in terms of either their symmetry or their side chain configuration. The effect of these variables on drug uptake and photodynamic cell kill were tested. The absorption wavelengths for the drugs were measured and a shift to the red was seen in the presence of cells. Drug uptake was measured and the cationic sensitizers had a relatively high uptake when compared to anionic HpD. The efficiency of the drugs in causing cell kill was expressed in terms of clonogenic cell survival. The asymmetric photosensitizers were more efficient in destroying mouse and human melanoma cells than the clinically used anionic HpD, which was in turn more efficient than the symmetric sensitizers tested.

Animals↗
PubMed1995

Optimum method for urinary drainage in major abdominal surgery: a prospective randomized trial of suprapubic versus urethral catheterization.

The outcome of suprapubic and urethral catheterization in abdominal surgery was compared in a prospective randomized trial. Twenty-eight patients received a suprapubic and 29 a urethral catheter. The groups were similar in terms of age, sex, operation performed and postoperative analgesia. There was no difference in the duration of catheterization (suprapubic: median 5 (range 4-10) days; urethral: median 4 (range 2-11) days). Urinary sepsis occurred in three patients in each group. Urethral catheters caused pain in significantly more patients (urethral 13; suprapubic two; chi 2 = 8.6, 1 d.f. P < 0.01), on more days (suprapubic: 6 of 142 catheter days; urethral: 37 of 126 catheter days; chi 2 = 29.5, 1 d.f. P < 0.001). Two men with urethral catheters and one with a suprapubic catheter failed to void urethrally when required to do so. Suprapubic catheterization is the method of choice for urinary drainage when this is required in abdominal surgery.

Abdomen↗