Search PubMed⌕ Search

Biomedical subjects

B Langer

Publications and source records attributed to B Langer.

At least 235 records · Page 13Linked to original sources

Hematogenous infection of peritoneovenous shunts after dental procedures.

In two patients who had peritoneovenous shunts inserted for the treatment of intractable ascites, the shunt became infected following dental procedures that were carried out without antibiotic prophylaxis. The organisms grown were alpha-hemolytic streptococcus in one patient, and alpha-hemolytic streptococcus and Klebsiella pneumoniae in the other. Alpha hemolytic streptococcus is commonly found in the oral cavity and has also been found, related to dental manipulations, in hematogenous infections at other sites. In both patients the infections were successfully managed by antibiotic treatment with removal of the infected shunt. Physicians caring for patients with peritoneovenous shunts should be aware of this potential complication; antibiotics should always be given prophylactically at the time of dental procedures.

Adult↗

Intermittent percutaneous infusion into the hepatic artery of cytotoxic drugs for hepatic tumours.

Between June 1, 1976 and Apr. 30, 1981, 157 patients were treated for inoperable cancer of the liver by intermittent percutaneous infusion of chemotherapeutic agents into the hepatic artery. The majority of these patients had metastatic colorectal cancer. The regimen of chemotherapeutic infusion evolved during the study and is described. The survival of the total group of patients is analysed according to type of cancer, extent of disease, dosage and combination of drugs. This therapeutic modality appears to benefit patients with metastases from colorectal cancer confined to the liver. The complication rate for this procedure is relatively low. The results from this study suggest that intermittent percutaneous infusion of cytotoxic agents into the hepatic artery is worthwhile for selected patients and should be studied further in combination with other forms of therapy.

Adult↗

Structure and function of small bowel allografts in the dog: immunosuppression with cyclosporin A.

Pairs of mongrel dogs received orthotopic total small bowel allografts. Half were treated with the immunosuppressive agent cyclosporin A and the other half were not. Ten untreated dogs survived a mean of 12.5 days (range from 7 to 25 days). They lost up to 30% of their initial body weight and rejection with hemorrhagic necrosis was usually the cause of graft failure. The mean survival of 11 dogs treated with cyclosporin A was 90.6 days (range 9 to 286 days) with early deaths being due to pneumonia or volvulus. Intestinal mucosa appeared normal, but there was some smooth muscle hypertrophy. Reconnection of lymph vessels was complete in all dogs examined more than 21 days after allografting. Two dogs survived for 203 and 221 days, respectively, and one dog remains alive and well 287 days after operation. The long-term survivors remained healthy, with steady body weights, formed stools, normal plasma protein values and xylose absorption curves that did not differ from those of autografted dogs. Roentgenography after a barium meal and follow-through study showed normal mucosa. The transit time was around 60 minutes (normal 150 minutes). Late, acute episodes of rejection occurred in two dogs, when blood levels of cyclosporin A were low (less than 400 ng/ml). Bowel mucosa showed ulceration and villous atrophy, with lymphoid infiltration, leading to malabsorption as a terminal event. Cyclosporin A is effective in increasing the duration of survival in dogs with small bowel allografts while maintaining essentially normal bowel structure and good function.

Animals↗

Iatrogenic bile-duct strictures.

Management of iatrogenic stricture of the bile ducts is difficult and is associated with substantial morbidity and mortality. At the Toronto General Hospital, 61 patients with strictures following operative trauma underwent a total of 75 repairs. The overall success rate was 80%. End-to-end duct repair is preferred when feasible; 8 of the 61 patients were treated this way, with success in 7. In the majority of patients, however, extensive duct scarring and shortening preclude its use, necessitating Roux-en-Y hepaticojejunostomy, done in 53 cases. If the anastomosis is adequate, with good mucosal approximation, a stent is not essential and of 12 such operations, 10 were successful. Even when the mucosa-to-mucosa apposition is less than optimal, the use of a straight-tube stent or changeable U-tube stent may produce a satisfactory end result. Of 41 such operations, 31 were successful. Since iatrogenic bile-duct strictures lead to high morbidity and frequent recurrence despite seemingly adequate repair, continued emphasis should be placed on prevention of injury, especially during routine cholecystectomy. Experience, careful dissection, knowledge of anatomic variations and good judgement concerning the performance of a cholecystostomy in difficult situations, should all reduce this complication to a minimum.

Adolescent↗

Dose-related effects of the synthetic met-enkephalin analogue FK 33-824 on esophageal motor activity in healthy humans.

The effects of FK 33-824, a methionine enkephalin analogue, 313, 625, 1250, 2500, and 5000 ng/kg body wt intramuscularly, on esophageal motor activity and cardiovascular and central nervous functions were studied in 8 healthy men. In the lower one-third of the esophagus, amplitude and duration of swallow contractions increased dose-dependently within 15 min after administration. In the middle one-third, amplitudes increased only slightly, whereas no systematic changes occurred in the upper one-third. The propagation velocity of the deglutitive wave accelerated dose-dependently between 15 and 10 cm as well as between 10 and 5 cm above the lower esophageal sphincter, the acceleration being more pronounced in the distal segment. Heart rate and systolic and diastolic blood pressure increased dose-relatedly, while no effects were found on electroencephalogram and reaction time. These results, together with earlier findings, support the notion of a participation of enkephalins in the regulation of the smooth muscle esophagus.

Adult↗

Urinary excretion of N-acetyl-beta-D-glucosaminidase and alanine aminopeptidase in patients receiving amikacin or cis-platinum.

Urinary excretion of alanine aminopeptidase (EC 3.4.11.2) and N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30) was determined for 25-70 days in five patients receiving cis-platinum and for 8-53 days in six patients receiving amikacin. This study was performed to investigate if the excretion of urinary enzymes represents a sensitive parameter for the early detection of toxic kidney damage. The determination of N-acetyl-beta-D-glucosaminidase was carried out by the method of Knoll et al. [13]. The procedure of Mondorf et al. [14] for the estimation of alanine aminopeptidase activity was adapted to the Gemsaec Fast-Analyzer. In both patient groups an increase in the excretion of the two enzyme activities could be demonstrated. In patients receiving amikacin, the excretion of alanine aminopeptidase was always higher than that of N-acetyl-beta-D-glucosaminidase, whereas in three patients receiving cis-platinum it was the opposite. In two cis-platinum patients the excretion of both enzymes was of the same size. The changes during amikacin therapy seem to be reversible, whereas in four cis-platinum patients these changes seemed to be partly irreversible. Serum creatinine concentration was less sensitive than the urinary enzyme excretion for detection of kidney damage.

Acetylglucosaminidase↗

An evaluation of root resections. A ten-year study.

A study was undertaken to evaluate the long term results of root resections. Records of 100 patients who had undergone root resections 10 years prior to the study were reviewed. Although the immediate postoperative results were gratifying, they were not always lasting. Eighty-four per cent of the failures occurred after 5 years. Most failures were in the mandibular arch and derived from reasons other than inflammatory periodontal disease. Suggestions are made as to how to improve the prognosis of resected teeth.

Apicoectomy↗

Early re-entry procedure. Part II. A five year histologic evaluation.

The following study was carried out to assess the histologic integrity of a bone graft which had appeared clinically successful at early re-entry some 5 years previously. The tooth required extraction due to a labial root fracture and was subsequently extracted in modified block section, demineralized, sectioned, stained and evaluated histologically. Histologic evaluation revealed the presence of a functional periodontal membrane apparatus in active stages of both bone and cemental remodeling. Necrotic bone spicules within the areas of otherwise viable periodontium suggested residue from prior graft material. Histologic evaluation presented here supports the previous clinical impression that early re-entry of autogenous grafts for evaluation and physiologic recontouring, where indicated, appears justified without apparent adverse effects on local periodontal regeneration.

Alveolar Process↗

Renal and hemodynamic effects of the peritoneovenous shunt. II. Long-term effects.

The long-term renal and hemodynamic effects of the peritoneovenous shunt for intractable ascites were studied in 11 patients to elucidate the mechanism of its persistent beneficial effect. Sodium balance studies were performed in 7 patients. All had patent shunts and no clinically detectable ascites. On a 20-mEq sodium diet, the mean sodium excretion was 17.2 +/- 5.3 mEq/day which was increased over the preoperative mean of 2.4 +/- 0.4 (p < 0.025) on the same diet. There was a 100% increase in creatinine clearance over the preoperative level (p < 0.0005). The mean plasma renin activity and serum aldosterone levels were within normal limits in most patients, and the sodium excretion correlated inversely with the levels of each. During 100-mEq sodium challenge diet, the sodium excretion ranged from 4 to 130 mEq/day with a mean of 56.1 +/- 16.5 and with 6 of the 7 patients displaying sodium retention. On this diet the mean creatinine clearance was 104.3 +/- 6.4 ml/min, and the mean plasma renin activity and serum aldosterone levels had decreased physiologically with the higher sodium intake. Again the sodium excretion correlated inversely with the serum aldosterone on the 100-mEq sodium diet. In 8 patients, the portal pressure, as reflected by the wedge hepatic vein pressure, had decreased by a mean of 37% (p < 0.0005). But, despite this, 2 of the 8 patients had major variceal hemorrhages postoperatively. There was a significant inverse correlation between the increase in sodium excretion and the fall in portal pressure in 4 patients. Thus, sodium retention in cirrhosis is multifactorial with the reninaldosterone system and, possibly, portal hypertension per se both playing a role. Peritoneovenous shunting in carefully selected patients partially reverses the sodium retention and renders patients more manageable over the long term.

Aldosterone↗

Studies into the mechanism of reversal of experimental acute hepatic failure by hepatocyte transplantation. 1.

The authors reported previously that single cell suspensions of syngeneic, allogeneic and xenogeneic hepatocytes can significantly improve survival in a rat model of acute hepatic failure induced by D-galactosamine. This report explores the mechanism by which hepatocyte transplantation reverses the toxin-induced hepatic necrosis. Radioautographic studies indicated that intraperitoneally administered hepatocytes labelled with tritiated thymidine did not repopulate the injured recipient liver. Hepatocytes irradiated with 10 000 rad (i.e., the cells were nonreplicating) also resulted in a significant (P less than 0.001) increase in animal survival when given to rats treated with D-galactosamine. Experiments with subcellular fractions of hepatocytes demonstrated that an intact cell was not required and that a heat stable "factor" (or factors) present in the cytosol fraction, which is not insulin or glucagon, is responsible for the increase in survival observed. This factor appears to increase the rate of endogenous regeneration of the injured recipient liver.

Animals↗

The acute effects of sustained volume expansion on the renin-aldosterone system and renal function in human hepatic ascites.

To investigate the acute effect of sustained volume expansion in patients with chronic hepatic ascites, renal and hemodynamic studies were performed on six patients receiving the peritoneovenous shunt. Within 1 hr of shunt insertion, the cardiac output rose by 20% to 60% above the preoperative level and the renal blood flow by 70% to 300%. At the same time both the plasma renin activity and serum aldosterone levels fell to a mean of 34% of the preoperative levels. The urine output increased from fourfold to 38-fold, but the sodium excretion increased in only two of the six patients. The data show that the acute effect of sustained volume expansion is predominantly on water rather than on sodium excretion. This manoeuver acutely suppressed circulating renin and aldosterone levels; however, the blunted natriuretic response suggests that other factors are involved in the sodium retention in these patients.

Aldosterone↗