Search PubMed⌕ Search

Biomedical subjects

H D Becker

Publications and source records attributed to H D Becker.

At least 127 records · Page 7Linked to original sources
PubMed1997

[Surgery of Crohn disease in the course of time--a retrospective analysis of 1,044 operations].

In 591 patients with Crohn's disease, 1044 operations were performed within 16 years. The aim of this study was to evaluate the changes in treatment time, indication for surgery, surgical technique, and postoperative complications. There was a significant reduction in treatment time (in-patient), whereas the number of operations in general increased. The frequency of emergency operations has declined. The postoperative complication rate did not change, but there was a correlation between emergency operation and the complication rate. Surgery for perforating Crohn's disease, acute intestinal obstruction or intra-abdominal abscess also correlated with a significantly higher complication rate.

Colectomy↗
PubMed1996

Identity of prokaryotic and eukaryotic tRNA(Asp) for aminoacylation by aspartyl-tRNA synthetase from Thermus thermophilus.

The aspartate identity of tRNA for AspRS from Thermus thermophilus has been investigated by kinetic analysis of the aspartylation reaction of different tRNA molecules and their variants as well as of tRNAPhe variants with transplanted aspartate identity elements. It is shown that G10, G34, U35, C36, C38, and G73 determine recognition and aspartylation of yeast and T.thermophilus tRNA(Asp) by the thermophilic AspRS. This set of nucleotides specifies also tRNA aspartylation in the homologous yeast and Escherichia coli systems. Structural considerations indicate that the major aspartate identity elements interact with amino acids conserved in all AspRSs. It follows that the structural features of tRNA and synthetase specifying aspartylation are mainly conserved in various structural contexts and in organisms adapted to different life conditions. Mutations of tRNA identity elements provoke drastic losses of charging in the heterologous system involving yeast tRNA(Asp) and T. thermophilus AspRS. In the homologous systems, the mutational effects are less pronounced. However, effects in E. coli and T. thermophilus exceed those in yeast which are particularly moderate, indicating variations in the individual contributions of identity elements for aspartylation in prokaryotes and eukaryotes. Analysis of multiple tRNA mutants reveals cooperativity between the cluster of determinants of the anticodon loop and the additional determinants G10 and G73 for efficient aspartylation in the thermophilic system, suggesting that conformational changes trigger formation of the functional tRNA/synthetase complex.

Amino Acid Sequence↗
PubMed1996

Liposoluble antioxidants are not consumed in the pancreas after reperfusion in human simultaneous pancreas-kidney transplantation.

There is considerable evidence that under experimental conditions, oxygen free radicals (OFRs) are decisive in the pathogenesis of ischemia-reperfusion injury. Normally OFRs are scavenged by antioxidants such as alpha-tocopherol. Thus, in the following study we investigated whether antioxidants are consumed locally in human pancreatic grafts after reperfusion. A series of ten patients receiving bladder-drained pancreaticoduodenal and renal allografts were studied. Sequential blood samples were drawn locally from the venous outflow of the graft and simultaneously from the radial artery after reperfusion. alpha-Tocopherol, retinol, lycopene, and alpha- and beta-carotene levels were determined. After reperfusion these levels remained largely unchanged. Hence, in our study a consumption of antioxidants locally in the pancreatic graft after transplantation was not demonstrated. Therefore, the antioxidant capacity seems not to be exhausted at that time. This suggests that in clinical pancreatic transplantation oxidant stress in the initial reperfusion period might not have the relevance suggested by animal models.

Antioxidants↗
PubMed1996

[Therapy of carcinoids of the stomach].

Carcinoids of the stomach are rare but have gained importance since the introduction of acid secretion inhibitors. The most important type is the tumor occurring in patients with chronic atrophic gastritis with and without pernicious anemia. The tumors are benign and can be treated by local endoscopic or surgical methods. Antrectomy reduces hypergastrinemia and may cause regression of the tumor. Sporadic carcinoids of the gastric antrum are malignant, however, and require radical surgical treatment.

Adult↗
PubMed1996

Determinants of a normal (versus impaired) oral glucose tolerance after combined pancreas-kidney transplantation in IDDM patients.

After successful pancreas transplantation, insulin-dependent diabetic patients are characterized by a normal or at worst impaired oral glucose tolerance (World Health Organisation criteria). It is not known which pathophysiological mechanisms cause the difference between normal and impaired oral glucose tolerance. Therefore, we studied 41 patients after successful combined pancreas-kidney transplantation using stimulation in the fasting state with oral glucose (75 g), intravenous glucose (0.33 g/kg) and glucagon bolus injection (1 mg i.v.). Glucose (glucose oxidase), insulin and C-peptide (immunoassay) were measured. Repeated-measures analysis of variance and multiple regression analysis were used to analyse the results which showed: 28 patients had a normal, and 13 patients had an impaired oral glucose tolerance. Impaired oral glucose tolerance was associated with a greatly reduced early phase insulin secretory response (insulin p < 0.0001; C-peptide p = 0.037). Age (p = 0.65), body mass index (p = 0.94), immunosuppressive therapy (cyclosporin A p = 0.84; predniso(lo)ne p = 0.91; azathioprine p = 0.60) and additional clinical parameters were not different. Reduced insulin secretory responses in patients with impaired oral glucose tolerance were also found with intravenous glucose or glucagon stimulations. Exocrine secretion (alpha-amylase in 24-h urine collections) also demonstrated reduced pancreatic function in these patients (-46%; p = 0.04). Multiple regression analysis showed a significant correlation of 120-min glucose with ischaemia time (p = 0.003) and the number of HLA-DR mismatches (p = 0.026), but not with HLA-AB-mismatches (p = 0.084). In conclusion, the pathophysiological basis of impaired oral glucose tolerance after pancreas transplantation is a reduced insulin secretory capacity. Transplant damage is most likely caused by perioperative influences (ischaemia) and by the extent of rejection damage related, for example, to DR-mis-matches.

Adult↗
PubMed1996

Local therapy of rectal tumors.

PURPOSE: The aim of the study is to outline the rising importance of local treatment of rectal tumors and a changing strategy in therapy of early rectal cancer. METHODS: As the surgical procedure, transanal endoscopic microsurgery was used. Indications for the local procedure were pT1 low-risk tumors and tumors of higher stages in patients with severe risk factors and of those who refused the operation according to oncologic guidelines. RESULTS: A total of 236 rectal adenomas and 98 carcinomas were locally excised using the transanal endoscopic microsurgery technique. Mortality rate was 0.3 percent, and rate of complications requiring surgical reintervention was 5.5 percent in adenomas and 8 percent in carcinomas. Final histology of removed carcinomas revealed 56 pT1, 27 pT2, and 15 pT3 stages. After an average follow-up time of 24 months, two recurrences were observed in the group of patients with pT1 low-risk carcinomas who only underwent local therapy. In both cases, a second intervention for cure was undertaken but for tumors in a late stage. CONCLUSIONS: In selected cases, local therapy of rectal carcinoma avoids high morbidity and mortality of the classical operation. Quality of life will be improved, especially if an artificial anus can be avoided. In case of recurrence, the chance of a secondary procedure for cure is not to be underestimated.

Adenoma↗
PubMed1996

Functional results after transanal endoscopic microsurgery.

PURPOSE: Compared with traditional operations, superior results after transanal endoscopic microsurgery (TEM) for rectal tumors have been demonstrated in terms of morbidity and mortality. However, no data were available on functional outcome after TEM. We, therefore, studied 42 patients who were undergoing TEM. METHODS: Patients were examined by anorectal manometry and participated in a standardized interview preoperatively and three months and one year after surgery. RESULTS: Anorectal function as assessed by manometry was impaired three months after surgery but improved again during the first postoperative year. In parallel, some patients complained of impaired continence or defecation disorders in the interview three months postoperatively. These functions improved during the first year after surgery, too. CONCLUSIONS: Correct comparison of our results with functional outcome after anterior rectal resection is impossible. We feel, however, that functional results after TEM are likely to be superior to those after anterior resection for rectal tumors.

Adenoma, Villous↗
PubMed1996

[Endobronchial ultrasound--a new perspective in bronchology].

AIM: Since the view of the endoscopist is restricted and radiological procedures are unreliable in the diagnosis of mediastinal disease, we investigated endobronchial ultrasound in a preliminary clinical study. METHODS: Two of the systems tested, Olympus and Sonotron (CVIS), proved to be applicable after some modifications. They were tested in a phantom, in resection specimens and in 500 bronchoscopies. RESULTS: In tumor staging infiltration of the bronchial wall and parabronchial structures could be assessed. Lymph nodes could be detected down to 3 mm, but not even by in vitro examination of 84 resected lymph nodes could we find reliable signs for malignancy. Infiltration of the bronchial wall and involvement of large vessels by mediastinal masses was frequently diagnosed. Involvement of the airways by vascular anomalies, pleural effusion or solid masses could be differentiated. CONCLUSIONS: In view of the fact that the procedure costs around $20, it seems feasible and we are currently examining its value in a prospective study.

Bronchi↗
PubMed1996

Prospective study of the proctographic and functional consequences of transanal endoscopic microsurgery.

A prospective study of clinical, manometric and proctographic results in 36 patients presenting for transanal endoscopic microsurgery was performed. Anorectal manometry showed no difference in maximal squeeze pressure before and 12 months after operation, but resting pressures were lower after surgery (mean(s.e.m.) preoperative 86.1(27.6) mmHg versus postoperative 67.2(23.2) mmHg, P < 0.05). The rectoanal inhibitory reflex was lost in a significant group of patients (reflex present in 34 of 36 patients before operation and in 27 of 36 12 months after operation, P < 0.05). Proctography, manometry and questionnaire showed preserved function of most modalities 12 months after operation such that if objective function was impaired clinical function was adequate.

Adult↗
PubMed1996

Future diagnostic procedures.

Although the exact proportion of patients with carcinoma in situ in whom disease will progress to invasive lung cancer is not known, and although there have been reports that some individuals may continue to show malignant cells in sputum for several years without symptoms or abnormality on chest radiograph, untreated or suboptimally treated carcinoma in situ has been shown to progress to invasive cancer or metastatic disease. A study by Frost and co-workers showed that cancer developed in approximately 10% of individuals with moderate atypia and 40% of those with severe atypia in sputum cytology. Therefore, the proportion of individuals with carcinoma in situ in whom invasive cancer will develop is likely to be greater than 40%. Lung cancer is almost uniformly fatal when untreated, and, if the disease is allowed to progress to the invasive stage, the results of currently available therapy are poor. A lesson must be learned from cervical cancer screening. As has been shown by Anderson and co-workers, if individuals harboring dysplasia or carcinoma in situ are actively sought for and treated by laser or cryotherapy, the incidence and mortality of invasive cervical cancer can be reduced to extremely low levels. If current work directed toward detecting early lung cancer in sputum cytology specimens in high-risk groups using quantitative image cytometry or molecular markers is successful, the ability to localize small preinvasive lesions with fluorescence bronchoscopy will become even more important for the pulmonologist or thoracic surgeon. Endoscopic ultrasound can be used to determine the depth of tumor infiltration into the bronchial wall or adjacent structures. Biopsy of mediastinal and peribronchial lymph nodes can be performed under sonographic guidance for more accurate staging. By coupling sensitive diagnostic tools to new treatment modalities, such as chemoprevention and various endobronchial therapies, it is hoped that the traditionally poor prognosis for patients with lung cancer can be altered in the near future.

Bronchoscopes↗
PubMed1996

[Evaluating elective surgical procedures in ulcer surgery].

Elective surgical treatment of peptic ulcers is less important after the introduction of effective conservative treatment. However, in a chronic recurrent disease all options of treatment have a place. In duodenal ulcer highly selective vagotomy is the procedure of choice despite the high recurrence rate, since it has a low operative risk and a low rate of early postoperative morbidity or late sequelae. In gastric ulcer distal partial gastrectomy (Billroth I) must be recommended using the same criteria. Laparoscopic techniques will not alter the indication for surgery; these procedures are still hampered by technical problems and the main problem of high recurrence rate after vagotomy is not solved by choosing a different approach to the abdomen. Surgical treatment of peptic ulcers must be revalidated in respect to health care reform.

Gastrectomy↗
PubMed1996

[Recurrent hematemesis and hemobilia in ruptured hepatic artery aneurysm--differential diagnostic aspects of acute, upper gastrointestinal hemorrhage].

Aneurysms of the hepatic artery are mostly localized extra hepatic (80%). Today atherosclerosis is the most prevalent etiology (32%), followed by trauma (22%) and inflammatory lesions (10%). Rupture or perforation of the aneurysm is the initial clinical manifestation (60-80%), and occurs with nearly equal frequency into the peritoneal cavity and into the hepatobiliary tract. Rupture into bile ducts is often responsible for characteristic findings of upper gastrointestinal bleedings with hematemesis. The case of a 38 year-old man is presented and the clinical manifestation, the diagnostic and therapeutic procedures are demonstrated.

Adult↗
PubMed1996

[Local therapy of rectum carcinoma. A prospective follow-up study].

Local therapy of rectal carcinoma with the method of TEM was performed in 98 patients during the period from August 1, 1989 to January 31, 1994. 56 of the patients had pT1, 27 pT2, and 15 pT3 tumours. There was no lethality. The rate of complications, which required operative intervention, was 8%. No lymph node metastases were found in the specimens of the patients with pT1 tumours, who were re-resected, because the margin of the primary specimen were judged to be not free of tumour. In the specimens of the re-resected patients with pT2 carcinomas, lymph node involvement was more common than remnants of the primary tumour. Two of the patients with local therapy of pT1 low-risk carcinomas developed a recurrence so far. A secondary procedure for cure according to oncologic criteria could be performed in both cases. In selected cases the local therapy of rectal carcinoma avoids the high morbidity and mortality of the classical operation. Live quality will be improved, especially if an artificial anus can be avoided. In case of a recurrence the chance of a secondary procedure for cure is not to be underestimated.

Adult↗
PubMed1996

[Does piggy-back liver transplantation have a detrimental effect on venous drainage?--A comparative duplex ultrasound study].

Venous drainage in "Piggy-back" Liver Transplantation "Piggy-back" orthotopic liver transplant (OLT) may offer some advantages (hemodynamic stability without veno-venous bypass) over standard OLT, but there is concern about the risk of venous outflow obstruction associated with this technique. In this study (n = 19 piggy-back, n = 12 standard OLT) it was possible to show, by means of duplex scanning, that flow velocity, resistance and flow of hepatic veins do not differ significantly.

Adult↗
PubMed1996

[Therapeutic effect of argon plasma coagulation on small malignant tumors of the gastrointestinal tract].

The use of argon plasma coagulation has proved to be an effective method of non-contact electrocoagulation with high efficiency in palliative treatment of gastrointestinal lesions. In this study there were 10 patients suffering from small oesophageal malignant tumors; in 5 patients no further tumor could be detected in biopsies during a period up to 34 months, in the other cases passage could kept open. These results suggest this treatment as an alternative therapy in selected patients.

Biopsy↗