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Biomedical subjects

B Langer

Publications and source records attributed to B Langer.

At least 199 records · Page 11Linked to original sources

Radiologic diagnosis of nonsquamous tumors of the head and neck.

Nonsquamous cell tumors of the head and neck can be reliably identified and often accurately diagnosed by proper state of the art radiologic assessment. For optimal diagnostic and preoperative work-up of head and neck lesions, complete radiologic analysis is now essential.

Head and Neck Neoplasms↗

Small intestinal transplantation. A closer reality.

The purpose of this study was to determine whether small intestinal transplantation could be considered as an alternative in the treatment of patients suffering from the short-bowel syndrome. The site of absorption of oral cyclosporine A was determined as were the changes that follow small intestinal transplantation. The interactions between the lipophilic cyclosporine A molecule and fat emulsion solutions used for total parenteral nutrition were investigated. Finally, a technique for harvesting the entire small bowel in man was developed. The absorption of oral cyclosporine A in normal dogs, and in bowel-resected, autotransplanted, and allotransplanted dogs was determined. Cyclosporine A levels were monitored in all animals. This demonstrated that cyclosporine A is absorbed through the small bowel and carried through the lymphatics; that absorption is decreased to 40 percent of normal after autotransplantation or allotransplantation without rejection. Rejection further hampers cyclosporine A absorption. Administration of olive oil alone enhances absorption of cyclosporine A. We also administered cyclosporine A IV to five dogs, with and without a concomitant infusion of fat emulsion solution (Intralipid). No changes in plasma cyclosporine A levels, in the clearance of cyclosporine A, or in the in vivo distribution of cyclosporine A were noted. Finally, dissections in six cadavers and in four brain-dead organ donors were performed, and a reproducible technique for harvesting the small bowel in man was established. In selected patients with the short-bowel syndrome, small intestinal transplant may be considered as an alternative therapy to home total parenteral nutrition.

Animals↗

Further report of a prospective randomized trial comparing distal splenorenal shunt with end-to-side portacaval shunt. An analysis of encephalopathy, survival, and quality of life.

We electively compared the distal splenorenal ("selective") shunt with the end-to-side portacaval shunt in 80 prospectively randomized patients with variceal bleeding. Selective shunts required more operative time (3.9 vs. 2.8 h) and blood replacement (4.6 vs. 2.5 U) and postoperative mortality was slightly higher (5 of 38 selective vs. 0 of 40 portacaval). Postoperative complication rates were similar. After 65-mo mean follow-up, both shunts have protected well against late gastrointestinal bleeding (5 selective, 4 portacaval episodes). However, after selective shunts, spontaneous encephalopathy occurred less often (23% vs. 40% of patients), was severe in fewer patients (12% vs. 33%), and precipitated fewer hospital admissions (6 admissions in 4 selective patients vs. 26 admissions in 13 portacaval patients). Furthermore, selective shunt patients remained longer without functional disability (83% vs. 70% of postoperative patient months). Long-term survival was not significantly different in the two groups (5-yr survival: selective 51%, portacaval 56%).

Adult↗

Periampullary tumors: which ones should be resected?

Resection was carried out in 118 patients for periampullary lesions. Ninety-eight of these were adenocarcinomas and were treated by the Whipple operation, total pancreatectomy, or local resection (87 patients, 7 patients, and 4 patients, respectively). Diagnosis of pancreatic head carcinoma before resection was falsely positive in 27 percent of the patients. Mortality for radical resection was 4 percent. Five year survival for ampullary carcinoma was 32 percent, and for pancreatic head carcinoma it was 7 percent. Resection of all periampullary tumors is recommended, with the Whipple operation being the standard in most cases.

Actuarial Analysis↗

Serendipitous adrenal masses: prevalence, significance, and management.

Over a 2 year period, 63 of 1,459 patients examined by computerized tomography were found to have adrenal masses. In 19 patients (1.3 percent of patients examined and 30 percent of patients with adrenal masses), they were unexpected and did not give rise to symptoms or signs. Three patients were explored. Two of the patients had adrenocortical adenomas and a third, a ganglioneuroma. Adrenal function tests were performed in 14 patients and showed evidence of Cushing's syndrome in 1 patients and revealed no abnormalities in 13. The lesions in 10 of 11 nonsurgical patients followed by computerized tomography for 11 to 36 months showed no change. One lesion became significantly smaller. In a review of 988 autopsy reports, grossly visible adrenal masses were present in 73 patients (7.3 percent), including 19 adrenocortical adenomas (1.9 percent) and 50 metastases (5 percent). We conclude that serendipitous adrenal masses are usually small, nonfunctioning, and benign, the most common lesion being adrenocortical adenoma. A protocol has been suggested for management to identify the minority of patients with functioning or malignant lesions and to avoid unnecessary surgery in the others who have benign disease.

Adenoma↗

Cyclosporine absorption in intestinal transplantation.

The absorption of oral cyclosporine (CsA) was studied in a canine small intestinal transplantation model. Absorption of CsA was almost absent in bowel-resected dogs. Autotransplanted dogs showed a persisting malabsorption of CsA (mean peak of 687 +/- 348 ng/ml vs. 1683 +/- 154 ng/ml in control dogs). Allotransplanted dogs with normal graft histology showed a similar malabsorption (mean increase in CsA level: 833 ng/ml), whereas allotransplanted dogs with rejection of the graft showed a markedly decreased absorption (mean increase: 368 +/- 31 ng/ml). In two autotransplanted dogs pretreated with olive oil alone, CsA absorption increased over four weeks to a mean peak of 2215 +/- 5 ng/ml. We conclude that oral CsA is absorbed through the small intestine. Absorption of CsA is decreased after autotransplantation and allotransplantation, and rejection of the graft impedes it further. Regular administration of olive oil alone enhances absorption of oral CsA in a canine model.

Animals↗

Pharmacokinetic profiles of cyclosporine in rats. Influence of route of administration and dosage.

This study was performed to determine the influence of different routes of administration and of variable doses of cyclosporine (CsA) on the pharmacokinetics of CsA in the rat. Seven groups of 4 adult female Lewis rats were given CsA once daily for 5 days: group 1: 5 mg/kg of CsA p.o. (by gavage); group 2: 10 mg/kg of CsA p.o.; Group 3: 5 mg/kg of CsA i.m.; group 4: 10 mg/kg of CsA i.m.; Group 5: 5 mg/kg of CsA s.c.; group 6: 10 mg/kg of CsA s.c., group 7: 10 mg/kg CsA i.p. CsA plasma levels were determined by RIA at 0, 2, 4, 6, 8, and 24 hr on days 1 and 4. Ease of administration was greatest in the s.c. groups (3 and 4), in which no anesthesia, no restraining device, and no special skills were required. Peak CsA levels varied greatly from group to group, as did trough levels and CsA bioavailability, as determined by the total area under the plasma CsA concentration-time curve. All groups exhibited great variation of CsA plasma level in the 24-hr period following administration, except group 3, in which the peak-to-trough difference was only 26.8% of peak level, as opposed to values over 60% in all other groups. We conclude that: (1) CsA may be administered to rats through different routes to achieve adequate plasma levels; (2) the route and dosage will greatly influence the pharmacokinetic profile of CsA; and (3) the SC route, in addition to being the easiest, provides reproducible and steady CsA plasma levels, with little variation over a 24-hr period.

Administration, Oral↗

Subepithelial connective tissue graft technique for root coverage.

This article describes the use of the subepithelial connective tissue graft as a donor source for root coverage. The success of these grafts has been attributed to the double-blood supply at the recipient site from the underlying connective tissue base and the overlying recipient flap. Four cases have been illustrated to demonstrate the versatility of this procedure for areas of single or multiple root coverage especially in the maxillary arch, coverage of existing crown margins and areas requiring a combination of ridge augmentation and root coverage. An increase of 2 to 6 mm of root coverage has been achieved in 56 cases over 4 years with minimal sulcus depth and no recurrence of recession. The donor site is a closed wound which produces less postoperative discomfort.

Connective Tissue↗

Experimental and clinical intestinal transplantation.

Before 1972 several attempts were made to perform small intestinal transplantation in man for the treatment of diseases leading to major losses of the small intestine. No patient had survived for more than 76 days despite intensive conventional immunosuppressants. Small intestinal allotransplantation has been investigated, experimentally, since 1959. Lillehei initially reported the results of allotransplantation of various lengths of small intestine in the canine model. Surgical techniques for successful allogeneic small intestinal transplantation as well as the methods for graft preservation, were clarified. Autotransplants of the total small bowel in dogs survived indefinitely. However, in dogs receiving total small intestinal allotransplants the mean survival period was 8-15 days. Both rejection and graft-versus-host disease have been implicated in the short survival of experimental animals. With the advent of cyclosporine and its known action against both rejection and graft-versus-host disease, we studied the results of parenteral cyclosporine on the survival of dogs following total small intestinal allotransplantation. Cyclosporine greatly prolongs survival to a mean of 103 days, following transplantation of the small bowel, compared to only 12 days in dogs not receiving any immunosuppressive agent. Two of the treated dogs lived for longer than 200 days and one dog lived for more than 400 days. Following this, we have developed a method of histological monitoring of the allograft by making two exterior isolated pouches of the allograft, representing the histological events leading to rejection of the in-continuity bowel.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Colorectal cancer: managing distant metastases.

The best opportunity for cure in colorectal cancer is early diagnosis and complete excision of the primary disease. Currently, metastatic disease develops in about 50% of patients, most often in the liver. Resection of solitary liver metastases is warranted, and a 5-year survival of at least 25% can be expected. Patients with limited unilobar multiple metastases may also benefit from resection. Extensive metastatic disease to the liver may respond to single or combination chemotherapy. Response rates are highest with hepatic artery infusion chemotherapy, but improvement in survival has not clearly been shown. Solitary or limited lung metastases, when unassociated with other metastatic disease, should also be resected. Multiorgan involvement may respond to systemic chemotherapy but results are generally poor. Palliation is an important objective of therapy, involving not only anticancer treatment (surgery, chemotherapy, radiotherapy) but also general supportive care.

Colonic Neoplasms↗

[Tocolysis using salbutamol in cases of cardiac rhythm disorders in the mother. Apropos of 4 cases].

Tocolysis was carried out in a case of paroxysmal junctional tachycardia (Bouveret) and there was an attack of paroxysmal tachycardia which resolved spontaneously. In a case of Wolff-Parkinson-White syndrome and in two cases of ventricular double extra-systoles, tocolysis was very well tolerated. A short discussion based on these four case histories is presented. The indication for the use of tocolytic drugs was discussed with the cardiologist. The cardiac state of these pregnant women under treatment was very closely monitored.

Adult↗

Carcinoma of the extrahepatic bile ducts: results of an aggressive surgical approach.

Ninety patients with adenocarcinoma of the extrahepatic bile ducts were treated between 1969 and 1984. Fifty-four tumors involved the upper third, 15 the middle third, and 21 the lower third of the common duct. Twenty-two patients had gallstones and five had inflammatory bowel disease. Forty-three patients had operations before definitive treatment; the diagnosis was made in only 18. Resection was accomplished in 30 patients (33%): 12 of 54 in the proximal third, six of 15 in the middle third, and 12 of 21 in the distal third. The mean survival in patients who underwent resection was 32 months (proximal third, 28 months; middle third, 32 months; lower third, 37 months). Surgical bypass was performed in 28 patients (mean survival 10 months) and intubation alone was performed in 24 patients (mean survival 8 months). Recurrent cholangitis occurred in 56% of intubated patients compared with 26% of patients treated without tubes. Radiation was used with resection and for palliation. Responses were observed, but the complication of radiation duodenitis has limited the dose. An aggressive approach to resection of bile duct tumors is possible with a low operative mortality rate and offers the best opportunity for cure as well as good palliation. Internal bypass is preferable to chronic intubation. The role of radiation therapy in this disease is still not clear.

Adenocarcinoma↗

Morphologic studies of intestinal allograft rejection. Immunosuppression with cyclosporine.

The usefulness of isolated intestinal pouches of an intestinal allograft for monitoring mucosal histology during rejection episodes was studied in a canine model. Total small intestinal autotransplantation was performed in four dogs, and allotransplantation in 18 dogs. Isolated pouches from the proximal and distal ends of the allografts were brought to the skin as stomas. Serial biopsies were obtained from these pouches. Nine allotransplants were treated with a suboptimal dose of cyclosporine. Nine allografted dogs were not immunosuppressed. Biopsies from all animals were normal the first two days postoperatively, and remained so in the autotransplants. Mononuclear cell infiltration in the lamina propria and submucosa was seen up to five days before death from rejection of the allograft in dogs on cyclosporine. At autopsy, all dogs had histologic findings in the transplanted bowel similar to those of simultaneously obtained pouch biopsies. The results show that histologic changes in isolated pouches from intestinal allotransplants reflect changes in the incontinuity segment of the graft and, therefore, such pouches can be used for histologic monitoring of the graft.

Administration, Oral↗

Functional monitors of rejection in small intestinal transplants.

Absorption of cyclosporine and uptake of radiolabelled glucose by the transplanted small intestine in the dog was investigated to develop physiologic markers of rejection. Cyclosporine in olive oil was given orally, and glucose-14C was instilled into an isolated pouch constructed from the transplanted jejunum. Biopsies were simultaneously obtained from an isolated pouch made from the transplanted ileum. The absorption data were correlated with the histologic findings. Absorption of cyclosporine was of the same magnitude in autotransplanted dogs as it was in allotransplanted dogs with a normal graft. Absorption of cyclosporine in allotransplanted dogs with histologic signs of rejection was significantly reduced. Peak uptake of glucose-14C was noted 5 to 10 minutes after instillation of the isotope in autotransplanted and allotransplanted dogs with a normal graft. Allotransplanted dogs undergoing rejection had a delayed appearance of peak uptake and significantly reduced absolute uptake. In conclusion, absorption of cyclosporine and uptake of radiolabelled glucose can be utilized as functional monitors of intestinal allograft rejection.

Animals↗