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Biomedical subjects

R B Smith

Publications and source records attributed to R B Smith.

At least 253 records · Page 14Linked to original sources
PubMed1984

Congenital abdominal aortic aneurysms: report of a case and review of the literature.

Congenital abdominal aortic aneurysms are medical curiosities because of their rare occurrence even in groups with hereditary derangements of connective tissue metabolism (e.g., Marfan's syndrome and Ehlers- Danlos syndrome). We present the case of a 2 1/2-year-old boy with a congenital aneurysm of the aortoiliac bifurcation managed by excision and graft replacement. No associated disorder of connective tissue or other pathogenetic mechanism was discovered in this patient. The authors have summarized the existing literature regarding these rare but potentially lethal aneurysms.

Aorta, Abdominal↗
PubMed1984

Does contralateral carotid occlusion influence neurologic fate of carotid endarterectomy?

Divergent opinions regarding operative risks and late prognosis of patients undergoing endarterectomy for carotid stenosis with contralateral carotid occlusion have prompted a review of the experience at Emory University Hospital from Jan. 1, 1978, through Dec. 31, 1982. Fifty-four patients (37 men, 17 women; mean age 63 years) who underwent carotid endarterectomy (CEA) with contralateral carotid occlusion (group I) were compared with 410 demographically similar patients without contralateral carotid occlusion (group II) who underwent 503 CEAs during the same interval. CEA indications in group I were the following and were proportionately similar to those of group II: hemispheric transient ischemic attacks, 22 patients; asymptomatic stenosis, 12 patients; nonhemispheric symptoms, 11 patients; previous cerebral infarction, eight patients; and vascular tinnitus, one patient. General anesthesia, routine intraluminal shunting, systemic heparinization, and arteriotomy closure without patch were routinely employed in both groups. Three patients in group I suffered permanent neurologic deficits after operation (5.6%) and two had transient postoperative deficits with complete recovery. Ten patients (2.0%) in group II suffered permanent neurologic deficits and 10 patients experienced transient neurologic events after operation. Neither the transient nor the permanent neurologic deficit rates were statistically different (p greater than 0.05; Fisher exact test) in the two groups. Operative mortality rates for group I and group II were 0% and 0.8%, respectively, and were not significantly different (p greater than 0.10; Fisher exact test). Late postoperative ischemic brain infarctions occurred in two patients in group I (3.8%) and in 13 patients (3.6%) in group II (p greater than 0.10; Fisher exact test). Kaplan-Meier survival analyses were virtually identical in both groups, with the majority of deaths caused by cardiac occlusion may undergo CEA with morbidity and mortality rates similar to those without contralateral occlusions. Contralateral carotid occlusion does not necessarily portend an unfavorable early or late prognosis after CEA.

Adult↗
PubMed1984

Variceal hemorrhage in the veteran population. To shunt or not to shunt?

Portasystemic decompression remains the most definitive procedure in the control of portal hypertension (PHT) and bleeding gastroesophageal varices (BGEV). However, controversy prevails regarding shunt timing, type, and even propriety, especially in alcoholics. Analysis of a recent portal hypertension questionnaire submitted to 75 university-affiliated Veterans Administration Medical Centers (VAMC) reflected optimism regarding portasystemic shunts for the management of bleeding varices; disappointingly, however, on the average, only 20 to 25 per cent of variceal bleeders underwent definitive surgical management of any type. Ending in January 1980, a 14-year experience at the Atlanta VAMC with 72 portasystemic shunts was reviewed and demonstrates that shunt procedures may be extended to the veteran, predominantly alcoholic, population. Criteria for successful patient selection and operation are presented. While elective variceal decompression, preferably by the distal splenorenal shunt operation, may be performed with minimal morbidity and mortality, more efficient control of alcoholism is essential to prevent late deaths from hepatic failure.

Adult↗
PubMed1983

Human insulin.

Explore the source record for details and available documents.

Humans↗
PubMed1983

Alprazolam kinetics in the elderly. Relation to antipyrine disposition.

The pharmacokinetics of alprazolam, a triazolobenzodiazepine anxiolytic-antidepressant, were assessed in 32 healthy men and women aged 21 to 78 years after a single 1.0-mg oral dose. Peak alprazolam levels averaged 20.4 ng/mL and were reached a mean of 1.25 hours after dosage. Mean elimination half-life did not differ significantly between elderly and young women, nor did total metabolic clearance. However, half-life was significantly prolonged, and total clearance significantly reduced, in elderly v young men. Antipyrine oxidizing capacity was also evaluated, and half-life for the two drugs was highly correlated, as were their metabolic clearances. Thus, old age is associated with impaired capacity to oxidize alprazolam, but this effect is far more apparent in men than in women. A test of antipyrine half-life and clearance may help identify slow or rapid metabolizers of alprazolam.

Adult↗
PubMed1983

Dose-dependent pharmacokinetics and biliary excretion of bromophenol blue in the rat.

Concentrations of bromophenol blue (I) in plasma, urine, and bile were determined spectrophotometrically after intravenous bolus injections and infusions in rats. The plasma concentrations were found to decrease monoexponentially after all doses except the highest, where the decrease was biexponential. Although the disposition kinetics of I were apparently first-order at all doses, the half-life increased with increasing dose. The area under the plasma concentration-time curve (AUC0-infinity) increased disproportionately with increasing dose. The binding of I to rat plasma proteins, as determined by equilibrium dialysis, showed that the fraction bound (96%) remained constant in the concentration range of 10-300 micrograms/ml. Plasma concentrations were determined at time zero after intravenous administration and after a second dose administered 20 min later when plasma concentrations from the first dose were minimal. The apparent first-order elimination rate constant for the plasma concentration decline following the second dose was significantly less than after the first dose, indicating that the residual dye in the liver altered the elimination of I after the second dose. The fraction of the dose in the liver decreased with increasing dose, indicating a saturable uptake process. The biliary excretion profile reflected the uptake saturation that occurred in the liver and demonstrated that the biliary excretion of I depended on the amount present in the liver. When liver damage was induced by exposure to carbon tetrachloride, dye concentrations in the plasma, liver, and kidney increased markedly.

Animals↗
PubMed1983

Pharmacokinetics of triazolam in geriatric patients.

Serum triazolam levels were determined in eight geriatric patients (average age 80 years) on Days 1 and 7 of administration of triazolam 0.25 mg once daily, 1 h after a standard breakfast. Triazolam was rapidly absorbed reaching average peak concentrations of 2.0 and 2.04 ng/ml, 1.5 and 1.38 h after administration on Days 1 and 7, respectively. The mean apparent elimination half-life was 1.41 h (range 0.73-4.13 h) on Day 1 and 1.37 h (range 0.69-3.36 h) on Day 7. There was no significant difference between mean serum triazolam concentrations or pharmacokinetic parameters on Days 1 and 7 of the treatment. Serum samples were also assayed for alpha-hydroxytriazolam, an active metabolite of triazolam, but none could be detected in any of the samples from Days 1 or 7, assay sensitivity 0.09 ng/2 ml serum. The range of half-lives of triazolam in the patients in the present study is in close agreement with that previously reported in elderly subjects. The study provides further evidence of the lack of change in pharmacokinetic parameters on multiple dosing and that drug accumulation did not occur.

Aged↗
PubMed1983

The treatment of renal cell carcinoma with human leukocyte alpha-interferon.

An extended phase II trial of human leukocyte (alpha) interferon was done in 48 patients with measurable metastatic renal cell carcinoma, 43 of whom were evaluable. Of these patients 1 (2.5 per cent) had a complete response that was maintained after 19 months, 6 (14 per cent) had a partial response and an additional 23 per cent had either a minimal response or stabilization of previously growing metastases for greater than 3 months. Toxicity caused termination of treatment in only 1 patient and generally was tolerable. Major toxicity consisted of fever (80 per cent), fatigue (80 per cent) and hematologic toxicity (42 per cent), which was severe in only 2 patients. Characteristics of patients responding to therapy were good performance status, previous nephrectomy and metastases limited to the lungs. The results achieved with human leukocyte interferon were superior to those achieved by immunotherapy or chemotherapy at this and other institutions, and further trials are warranted.

Adenocarcinoma↗
PubMed1983

Treatment of advanced seminoma with pre-radiation chemotherapy.

Seminoma is one of the most radiosensitive of solid tumors. However, the survival rate of patients with clinically advanced stages B3 and C disease is poor. Because of this dismal prognosis we instituted a protocol of pre-radiation chemotherapy in an attempt to improve the survival rates. A chemotherapeutic regimen, consisting of 2 to 3 courses of vincristine, actinomycin D and cyclophosphamide, was administered before radiotherapy. Of 16 patients studied 15 (93.7 per cent) had a complete response to the combined treatment regimen. We believe that pre-radiation chemotherapy is indicated in all patients with advanced seminoma.

Adult↗
PubMed1983

Risk of urinary incontinence following radical prostatectomy.

Of 143 prostatic cancer patients treated with radical prostatectomy 38 had undergone transurethral resection of the prostate before the prostatectomy. After radical prostatectomy 5 per cent of the patients who did not have a resection and 8.1 per cent of those who did were severely incontinent. This difference is not statistically significant.

Adult↗
PubMed1983

Ibuprofen and sulindac kinetics in alcoholic liver disease.

Ibuprofen and sulindac kinetics after oral doses were compared in 15 patients with alcoholic liver disease and 29 normal subjects. The patients with alcoholic liver disease were divided into a group with fair hepatic function (FHF) and a group with poor hepatic function (PHF) based on elimination rates of indocyanine green. The effects of alcoholic liver disease on the ibuprofen kinetics were minimal. The absorption of the drug appeared to be delayed in some of the PHF patients, and slight differences were noted in the serum AUC and the elimination rate constant for ibuprofen. The absorption of sulindac was delayed in both PHF and FHF groups of patients, as was the appearance of the active metabolite, sulindac sulfide, and the inactive metabolite, sulindac sulfone. The plasma AUC for sulindac sulfide in patients with poor hepatic function was four times that in normal subjects. The kinetics of sulindac, a pro-drug that relies on the liver for conversion to an active metabolite, were markedly affected by alcoholic liver disease.

Administration, Oral↗
PubMed1983

Intermittent positive pressure ventilation and high frequency ventilation in dogs with experimental bronchopleural fistulae.

This study evaluated respiratory and cardiovascular responses of canines in whom bilateral bronchopleural fistulae were created surgically, and in whom ventilation was varied between intermittent positive pressure ventilation (IPPV) and high frequency ventilation (HFV). An Emerson prototype ventilator was used for HFV at rates of 300-1400/min at driving pressures of 2.5, 5.0, and 10 psi. Gas exchange was judged by arterial and mixed venous blood gases. Cardiac performance was measured by cardiac index, heart rate, stroke index, stroke work index, systemic and pulmonary vascular pressures and resistances. Ventilation during IPPV with the fistula open resulted in a statistically significant increase in PaCO2 and a decrease in PaO2 when compared to both HFV modes. Variations in cardiac function in these open-chested animals were insignificant for all variables tested except pulmonary artery pressures which rose significantly in the IPPV group.

Animals↗