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Biomedical subjects

D R Smith

Publications and source records attributed to D R Smith.

At least 307 records · Page 17Linked to original sources
PubMed1978

Aluminum hydroxide: evaluation of two dosage forms and two dosing schedules in reducing intestinal phosphate absorption.

A crossover, randomized, eight-week trial using eight adult volunteers was undertaken to (1) determine the efficacy of aluminum hydroxide in decreasing gastrointestinal phosphate absorption, (2) compare the effectiveness of "with meal" and "between meal" dosing schedules, and (3) compare the effectiveness of the capsule and liquid dosage forms. Four treatments, each with a daily dose of approximately 6 g, were taken on a three-times-a-day regimen. The effectiveness of the treatment regimens was measured by using two variables: the decrease in total urinary phosphorus excretion, and the increase in the percent tubular reabsorption of phosphorus (TRP). Aluminum hydroxide treatment produced a significant change in urinary phosphorus excretion (p less than 0.0005) and in percent TRP (p less than 0.0005). For the study population, total urinary phosphorus excretion was the determining factor in changing the percent TRP. The increase in TRP and the decrease in total urinary phosphorus excretion was of the same degree regardless of dosage form or dosage schedule. Aluminum hydroxide was effective in decreasing phosphorus absorption as measured in this study. It appears that aluminum hydroxide capsules could be used with equal efficacy as the liquid dosage form in controlling hyperphosphatemia in patients with chronic renal failure who will not comply with a treatment program using the liquid.

Adult↗
PubMed1977

Blood flow in peripheral nerves. Normal and post severance flow rates.

Regional blood flow has been measured in the sciatic nerve of cats utilizing the method of hydrogen polarography. The mean baseline flow of the sciatic nerve in cats was found to be 43 ml/100 g/min +/- 1.6 SD. Flow rates were somewhat erratic in both the proximal and distal segments of the nerve following nerve severance. The erratic flows were observed over the first 30 min following nerve cutting and by 1 hr had essentially stabilized at approximately the pre-severance flow level.

Animals↗
PubMed1977

Absence of autoregulation in peripheral nerve blood flow.

Blood flow was measured in the sciatic nerve of cats utilizing the method of hydrogen polarography. The mean baseline blood flow for all animals was found to be 47.1 ml/100 g/min +/- 14.9 SD. The flow changes produced by lowering the blood pressure by exsanguination and elevation by the use of angiotensin were then evaluated. The highest (normal) levels of blood flow were observed between the mean blood pressures of 80-110 mm Hg. At mean systemic arterial pressures of less than 85, there was a marked decrease in peripheral nerve blood flow with no detectable flow being measured below mean systemic pressures of 50 mm Hg. Above 105 mm Hg mean arterial pressure, there was a very gradual and progressive decline in blood flow to the levels measured at 200 mm Hg. These findings indicate a complete absence of vascular autoregulation in the peripheral nerve trunks.

Animals↗
PubMed1977

Sequential hemodynamic studies in patients having aortic valve replacement with the Ionescu-Shiley pericardial xenograft.

Sequential hemodynamic studies were performed in 13 patients having aortic valve replacement with glutaraldehyde-stabilized pericardial xenografts. The investigation done preoperatively was repeated twice in all patients at mean intervals of 9.9 and 42.2 months following valve replacement. Annulus diameters of the valves were 19, 23, and 25 mm. Between the preoperative and the first postoperative investigation there was a significant increase in cardiac index (p less than 0.05) and a significant reduction in both pulmonary wedge and left ventricular end-diastolic pressures (p less than 0.01). At the first postoperative study the mean ejection systolic gradient across the three sizes of aortic pericardial xenograft was 7, 15.7, and 8.4 mm Hg at rest and 10, 19.6, and 13.7 mm Hg on exercise, respectively. The corresponding surface areas of the three valve sizes were 1.1, 1.5, and 1.62 cm2 at rest and 1.4, 2.1, and 2.03 cm2 on exercise. There was no significant change in any of these measurements between the first and the second postoperative study. The results have shown considerable postoperative hemodynamic improvement, insignificant transvalvular pressure gradients, and maintenance of the functional integrity of the pericardial xenograft up to 56 months following valve insertion.

Adult↗
PubMed1977

Regional cerebral blood flow with intracranial mass lesions. Part I: Local alterations in cerebral blood flow.

Focal changes in the cat cerebral blood flow were studied by the technique of H2 polarography. Areas studied included the caudate nuclei, thalami and midbrain. A unilateral mass effect was created by inflation of an epidural balloon. A rapid decrease in regional cerebral blood flow was noted ipsilateral to the mass at very small balloon volumes. This was followed closely by contralateral supratentorial decrease in regional cerebral blood flow. The normal midbrain blood flow was found to be preserved until total decompensation (herniation) occurred.

Animals↗
PubMed1977

Regional cerebral blood flow with intracranial mass lesions. Part II: Autoregulation in localized mass lesion.

Autoregulation of regional cerebral blood flow was evaluated in cats. In normal baseline situations autoregulation was invariably present. Concomitant to an enlarging mass, supratentorial loss of this protective mechanism was seen both ipsilateral and contralateral to the mass. There was relative preservation of midbrain autoregulation until very high balloon volumes were reached. There was no acute regulation upon balloon deflation.

Animals↗
PubMed1976

Radiculitis distress as a mimic of renal pain.

It is the experience of the urological author that radiculitis secondary to costovertebral joint derangement is the most common cause of lower abdominal pain. However, this pain is sometimes made worse when the patient is subjected to a flank incision for presumed renal disease, since the aftermath of a flank incision may be a downward pull on a rib owing to detachments of muscles attached to its superior surface. Emotional problems, too, befall many patients with radiculitis--despondency over delayed diagnoses or sensitivity at having been told their complaints are psychosomatic. Most often these difficulties disappear spontaneously once the pain is relieved. Definitive diagnosis requires orthopedic techniques. Unfortunately, few orthopedists are well versed or interested in the syndrome of renal pain. When they are, erroneous diagnosis can be corrected and a course of conservative or surgical treatment prescribed, with excellent results.

Abdomen↗
PubMed1975

Synthesis and microbiological activities of some monohalogenated analogs of tyrosine.

2-Chlorotyrosine and 2-bromotyrosine, as well as the previously reported 2-fluorotyrosine, were synthesized by hydrolysis of the condensation products from the appropriate benzyl bromide and ethyl acetamidomalonate and were compared with the corresponding 3-halotyrosines as growth inhibitors of Escherichia coli 9723, Streptococcus faecalis 8043 and Lactobacillus plantarum 8014. In contrast to the 2- and 3-fluorotyrosines which were equally effective as growth inhibitors, the 2-chloro- and 2-bromotyrosines were much more effective than the 3-chloro- and 3-bromotyrosines in inhibiting the growth of the three microorganisms. For each of the assay organisms, the growth inhibitions of all three 2-halotyrosines were reversed competitively in varying degrees by tyrosine.

Bromine↗
PubMed1975

Radiculitis distress as a mimic of renal pain.

It is the experience of the urological author that radiculitis secondary to costovertebral joint derangement is the most common cause of lower abdominal pain. However, this pain is sometimes made worse when the patient is subjected to a flank incision for presumed renal disease, since the aftermath of a flank incision may be a downward pull on a rib owing to detachments of muscles attached to its superior surface. Emotional problems, too, befall many patients with radiculitis-despondency over delayed diagnoses or sensitivity at having been told their complaints are psychosomatic. Most often theses difficulties disappear spontaneously once the pain is relived. Definitive diagnosis requires orthopedic techniques. Unfortunately, few orthopedists are well versed or interested in the syndrome of renal pain. When they are, erroneous diagnosis can be corrected and a course of conservative or surgical treatment prescribed, with excellent results.

Adult↗