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Biomedical subjects

T Stein

Publications and source records attributed to T Stein.

At least 91 records · Page 5Linked to original sources
PubMed1975

Biliary and urinary calculi: pathogenesis following small bowel bypass for obesity.

Of 93 patients with small bowel bypass for massive exogenous obesity, three developed calcium oxalate urinary calculi, four stones in their gallbladder, and one developed both gallstones and urinary calculi during a mean follow-up period of 17.6 plus or minus 9.0 months. The urinary oxalate excretion increased from 21.6 to 67.8 mg/24 hours (P smaller than .001); simultaneously, the urinary output decreased from 1,775 to 1,101 ml/24 hours (P smaller than .001). Postoperatively, there was a significant increase in the rate of bile salt synthesis from 1.6 to 4.9 gm/day (P smaller than .02) and in the bile sale glycine/taurine ratio from 4.6 to 6.8 (P smaller than .05). It is suggested that the postbypass increase in the biliary glycine/taurine ratio, with its consequent decrease in the zeta potential of the micelles in bile, is at least partly responsible for the increased incidence of cholelithlasis. The pathogenic basis for the increased incidence of urinary calculi is hyperoxaluria, which is probably related to an increased bile salt and glycine synthesis.

Adult↗
PubMed1975

Studies on bile salt deconjugation following small bowel bypass procedures.

Using the glycine-l-14C-cholic acid (14C-GCA) test, bile salt deconjugation and excretion were studied in 26 subjects with morbid exogenous obesity before and at selected intervals after jejuno-ileal bypass. In the preoperative group there was no malabsorption or intestinal bacterial deconjugation of the bile salts. In the immediate postoperative period (with relative sterilization of the bowel) there was only a trace of 14C in the breath, but the fecal 14C was highly elevated, indicating severe malabsorption without bacterial activity. In the 8 to 10 day postoperative period both the breath and fecal 14C content were highly elevated, indicating malabsorption and normal bacterial activity. Five to 8 months postoperatively both the breath and fecal 14C content showed only moderate elevation, indicating adaptation. It is suggested that the 14C-GCA test is useful in evaluating the adequacy of small bowel bypass procedures and also in following the adaptive response after the bypass. A significant increase in the breath and fecal 14C soon after surgery followed by rapid decrease suggests an adequate bypass and unusually fast adaptation. If the increase in the breath and fecal 14C soon after the bypass is only moderate, then that suggests an inadequate bypass.

Bile Acids and Salts↗
PubMed1975

Studies on the healing of anastomoses of small and large intestines.

It is well known that large intestine anastomoses tend to leak much more frequently than do small intestine anastomoses. These studies were undertaken to elucidate the pathophysioplogic basis of this phenomenom. Single layer interrupted silk suture anastomoses were performed in both the distal part of the ileum and the distal part of the colon in 29 dogs. The anastomoses were resected at one through eight days and 19 to 31 days after operations. Collagen response, vascular response and bursting strength at the site of anastomoses were investigated. The results demonstrated a statistically significant decrease in the collagen and vascular response of the large versus the small intestine. This differential response may play a role in the mechanism of the relatively high incidence of suture line separations observed after colonic anastomoses.

Animals↗
PubMed1975

The effects of small-bowel resection or bypass on the rat skeleton.

The bones of adult rats became progressively osteopenic 1 to 5 weeks following jejunoileal bypass or resection. These changes were accompanied by increased levels of metaphyseal enzyme activities as well as by loss of histochemically identifiable osteoid. Osteoid tissue and the ability to mineralize skeletal collagen were recovered more rapidly and fully in the resection group than in the bypass group. Metaphyseal alkaline phosphatase concentrations increased in both groups coincident with the elevated lysosomal enzymes levels, and the skeletons showed a calcium deficit (low Ca/HOPr ratio) within the first 3 weeks. In resected rats the osteopenia and bone blood chemistry were consistent with hyperparathyroidism secondary to impared Ca absorption. In bypassed rats the results suggest that the osteopenia might be related to the release of a "resorptive factor" from the excluded intestinal segment.

Acid Phosphatase↗
PubMedDate not supplied

Improvement of pulmonary venous flow Doppler signal after intravenous injection of Levovist.

The analysis of the pulmonary venous flow Doppler pattern can assist in the determination of the severity of mitral regurgitation and, in conjunction with transmitral flow pattern, the assessment of left ventricular diastolic dysfunction. In approximately one third of the cases, however, transthoracic ultrasonography is not able to record an adequately analyzable pulmonary venous flow pattern. The aim of the study was to examine and compare the effect of the echo-enhancing agent Levovist on the pulsed-wave Doppler flow quality of the transthoracic (TTE) and transesophageal (TEE) recorded pulmonary venous flow. In 26 consecutive patients a qualitative (score system) and quantitative analysis of pulmonary venous flow pattern was obtained before and after peripheral venous injection of Levovist at concentrations of 200 mg/ml (low dose) and 400 mg/ml (high dose). The amount of measurable studies for the antegrade pulmonary venous flow increased after the injection of Levovist from 85% to 96% for TTE and from 96% to 100% for TEE. The retrograde flow as seen by TTE was adequately analyzable in only 46% before and in 73% after the injection of Levovist (p < 0.02). Before any contrast enhancement the retrograde pulmonary venous flow recorded by TEE could be analyzed in 77% of the patients, with the percentage increasing to 88% and 92% after the administration of a low and high dose of Levovist, respectively (p < 0.05). In particular, the quality score of the retrograde flow was significantly altered by the administration of Levovist (increase from 1.8 +/- 1.0 to 2.6 +/- 1.1 [low dose Levovist], p < 0.05 and to 2.7 +/- 1.3 [high dose Levovist], p < 0.05). The pulsed-wave Doppler interrogation by TTE without Levovist underestimated the velocities of the antegrade and retrograde pulmonary venous flow. After Levovist was administered, the recorded values were comparable to those obtained by TEE. An analogous pattern is encountered when quantifying the duration of the retrograde flow component. Thus the peripheral venous injection of Levovist leads to an improved quality of the pulmonary venous flow Doppler signal recorded by TTE. On qualitative and quantitative evaluation the values recorded by TTE after administration of Levovist are comparable to those of the TEE technique without an echo-enhancing agent.

Adult↗
PubMedDate not supplied

The renewable hospital.

While medical technology and reimbursement policies continue to change, the hospitals that are supposed to change with them are increasingly outdated. In recent years, hospital architects have begun adopting designs aimed at preventing obsolescence.

Hospital Design and Construction↗