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Biomedical subjects

H D Becker

Publications and source records attributed to H D Becker.

At least 217 records · Page 12Linked to original sources
PubMed1990

The fibre Fabry Perot sensor. A long-term manometry sensor for quantitative intraluminal pressure measurement of the gastrointestinal tract.

Sensor dislocation of water perfused side-hole manometry catheters during longer periods of examination, as well as heavy expenditure on equipment and personal, are disadvantages of perfusion manometry. Such catheters have contributed substantially to the attempt to become independent of water as a transmitter medium in manometric pressure sensors for the upper gastrointestinal tract. Using the principle of the mirror interferometer of Fabry and Perot, we have developed and manufactured a fibre-optic Fabry Perot Sensor (FFP) which records local asymmetric pressure with constant sensitivity over the sensor surface area of 40 mm length. The FFP signal was compared with the pressure measured with a conventional four-side-hole perfusion catheter. The signal corresponding to long-term basal pressure of the lower oesophageal sphincter (LOS) varied over a normal range, and the signal presenting the pressure in the tubular oesophagus had a normal range determined from 15 healthy volunteers. Due to the phase modulation of its laser, the FFP is nearly independent of substantial artefacts.

Digestive System Physiological Phenomena↗
PubMed1990

[Minimally invasive surgery in tumors of the esophagus].

The endoscopic-microsurgical dissection of the esophagus (EMDE) was developed to reduce the operative risk of resecting tumor-bearing esophagus. Utilizing an operation-mediastinoscope, the esophagus is freed from surrounding tissues in a circular fashion. Blood vessels are coagulated and cut. Under good endoscopic view and minimal blood loss, the esophagus can be freed via a cervical incision and extracted caudally. Up to now the EMDE has been utilized in 7 patients. The intra- and postoperative course was without problems. In the future, we further expect to see a reduction in cardio-pulmonary postoperative complications.

Electrocoagulation↗
PubMed1990

[Insulinoma--diagnosis and therapy].

Insulin-producing tumors of the pancreas are characterised by clinical symptoms and the lack of correlation between serum insulin and blood glucose concentrations. CT and angiography are major diagnostic procedures. Surgical therapy prefers enucleation of the tumor together with the capsule. Today blind resections can be avoided.

Diagnosis, Differential↗
PubMed1990

Hypoxia/reoxygenation injury in liver: Kupffer cells are much more vulnerable to reoxygenation than to hypoxia.

Cell injury due to hypoxia and reoxygenation was studied in primary cultured rat Kupffer cells. Under hypoxic conditions only 20% of the cells had lost their viability after 12 h of incubation. In contrast, almost complete losses of cell viability were observed when reoxygenation was performed after 2, 4 or 6 h of hypoxia. The time-course of reoxygenation injury in Kupffer cells was characterized by a lag phase of 2 h during which no difference between reoxygenated and hypoxically incubated cells was apparent; during the next 4 h, there was an increase of up to 100% in the amount of nonviable cells in the reoxygenated cultures. These results indicate that Kupffer cells were much more vulnerable to reoxygenation than to hypoxia. The time-course of cell damage upon hypoxia/reoxygenation may indicate a self-destruction mechanism caused by an oxygen-triggered activation of these cells.

Animals↗
PubMed1989

[Surgical therapy of liver and bile duct tumors].

The most effective surgical therapy of primary liver cancer (HCC) or proximal bile duct cancer (BDC) is radical resection, but only 20% of the patients will undergo this procedure, because the remaining patients in the advanced tumour-stage or cirrhosis can be given palliative treatment only (chemo-embolisation for HCC, endoscopic or percutaneous draining with or without iridium-after-loading for BDC) or a liver transplantation (LTX), though under immunosuppression an early recurrence of the tumour is frequent. One-year survival after resection because of HCC without cirrhosis is represented by a figure of 80%, whereas with cirrhosis it is 18%; 3 years after LTX, 26% of patients are alive. Three-year survival in untreated BDC is 24%, after resection of the hilum 42%, after LTX 40%.

Bile Duct Neoplasms↗
PubMed1989

[Indications and results of using lasers in the trachea and bronchial system].

The Nd-YAG-laser is an ideal tool for surgery within the narrow bronchial system, provided indications, contraindications and a safe technique are observed. Complications of advanced tumors in the central bronchial system can be averted and patients can be treated by adjuvant therapy with reasonable median and long-term prognosis. In many cases of benign lesions patients can be spared the risks of major thoracic surgery. Complications are comparatively rare.

Airway Obstruction↗
PubMed1987

Role of cholecystokinin in the negative feedback control of pancreatic enzyme secretion in conscious rats.

Using a specific radioimmunoassay for cholecystokinin (CCK) we have studied the relation between circulating CCK concentrations and the feedback regulation of pancreatic enzyme secretion in conscious rats. Recirculation of diverted bile-pancreatic juice into the duodenum or intraduodenal perfusion of trypsin during biliary-pancreatic juice diversion produced basal output of amylase and trypsin and low portal CCK levels (less than 10 pmol/L). Biliary-pancreatic juice diversion or inactivation of trypsin caused increased CCK concentrations (peak values 50-100 pmol/L) and enzyme outputs. During biliary-pancreatic juice diversion, infusion of the CCK receptor antagonist proglumide suppressed the enzyme response without altering the increase in CCK. Measurement of portal and peripheral CCK during biliary-pancreatic juice diversion yielded values of 131 +/- 37 and 32 +/- 5 pmol/L, respectively. The peripheral CCK levels corresponded to concentrations achieved during exogenous CCK-8 infusion which resulted in similar enzyme outputs. Gel chromatography of portal plasma during diversion of biliary-pancreatic juice revealed one peak of CCK corresponding to CCK-8, and a larger peak eluted between CCK-33 and CCK-8, probably representing CCK-22. Similar CCK components were found in water extracts of jejunal mucosa, whereas the acetic acid extracts mainly contained CCK-33/39. We conclude that the negative feedback regulation of pancreatic enzyme secretion in rats is mediated by the release of CCK from the intestine and that the major molecular form of CCK in plasma is probably CCK-22.

Amylases↗
PubMed1987

Total denervation of the pancreas does not alter the pancreatic polypeptide response to food intake.

The secretion of pancreatic polypeptide (PP) seems to be controlled by vagal cholinergic mechanisms, since both vagotomy and atropine significantly inhibit the PP response to food intake, sham feeding or insulin hypoglycaemia. In the present study, we examined the PP response to a meal after orthotopic autotransplantation of the pancreas. Completeness of vagal pancreatic denervation was confirmed by the missing response of pancreatic protein and the PP response to insulin hypoglycaemia. Total vagal denervation of the pancreas did not alter the PP response to a meal (peak PP levels 402 +/- 41 pg/ml before transplantation compared to 510 +/- 98 pg/ml after operation). The secretion of PP after food intake seems not to be mediated by direct vagal innervation of the pancreas itself. Since pancreatic autotransplantation results in an interruption of gastropancreatic or enteropancreatic neural reflexes, our results confirm the findings of Debas et al. [Surgery 92:309-313, 1982] and strongly suggest that the PP response to nutrient stimuli is mediated by a humoral mechanism.

Animals↗
PubMed1987

Plasma cholecystokinin and pancreatic enzyme secretion in patients with coeliac sprue.

The aim of this study was to investigate simultaneously the endogenously stimulated exocrine pancreatic secretion and the cholecystokinin (CCK) response in patients suffering from coeliac sprue. A Lundh-test was performed in nine patients and twenty-six healthy volunteers. Basal plasma-CCK levels (3.4 +/- 0.5 pmol/l in sprue patients vs. 4.1 +/- 0.5 pmol/l in controls) and the integrated 120 min postprandial CCK values showed no differences in both groups. However, in controls the peak CCK value of 27.5 +/- 5.6 pmol/l appeared after 15 minutes whereas in sprue patients the peak of 18.9 +/- 4.5 pmol/l appeared after 60 minutes. CCK concentrations in duodenal biopsies of patients with coeliac sprue revealed significantly lower values compared to controls (123.4 +/- 37.4 versus 240.0 +/- 11.3 pmol/g wet weight). The stimulated lipase output was significantly lower throughout the whole sampling period in coeliac sprue patients whereas amylase output showed an inconstant reduction. The trypsin output was not altered. These results suggest that other mediators than CCK are responsible for the maintenance of trypsin output and for the reduction of lipase output in patients with coeliac sprue.

Adult↗
PubMed1986

Defense mechanism and macroscopic tumor growth in lung tissue.

A total of 126 resection specimens from malignant lung tumors were cut into serial sections, and tumor volume and macroscopic growth pattern were computed. Four characteristic tumor growth patterns could be separated: Tumors growing in bizarre, irregular shapes; Tumors growing in spheroid shapes; Tumors growing in ellipsoid shapes; Tumors growing in mixed growth pattern. The immunologic response of the host tissue was analyzed grading the number of lymphocytes, plasma cells, macrophages in and at the boundary of the tumor tissue. Lymphocytic subpopulations were analyzed in 46 cases using monoclonal antibodies (BS3/BS4; T3, OKT4, OKT8, OKT11, OKT14). The majority of lymphocytes were T-lymphocytes and monocytes in cases with inflammatory response of host tissue. The ratio of inducer/helper subset (OKT4+) compared to suppressor/cytotoxic subset (OKT8+) was similar in expression as reported for circulating peripheral T-lymphocytes. The different growth patterns depend upon cell type of tumor, immunologic response of the host tissue, and tumor volume. The findings indicate that tumor progression into lung tissue is partly due to "localized metastatic growth" of different tumor cell subpopulations.

Adenocarcinoma↗
PubMed1985

Iodine-induced thyrotoxicosis--a case for subtotal thyroidectomy in severely ill patients.

Iodine-induced thyrotoxicosis (IIT), due to iodine application in high amounts in patients with circumscript or disseminated thyroid autonomy, is complicated by a prolonged course, mainly due on the body's resistance to conservative therapy with thiourea derivates. Therefore, we decided to perform subtotal thyroidectomy in 16 thyrotoxic patients. This is in contrast to the common opinion that surgery should only be performed after normalization of thyroid hormones. In all 16 patients with severe IIT, including three patients with thyroid storm, hormone levels decreased within a few days after surgery to normal or subnormal values and the clinical picture of thyrotoxicosis disappeared. In the case of thyroid storm the signs of disorientation normalized within 1-3 days. One patient died 5 weeks after surgery due to severe concomitant diseases. One patient exhibited transitory respiration distress and another had postoperative hypocalcaemia. In nine patients L-thyroxine replacement became necessary because of subclinical or clinical hypothyroidism. Only by this procedure will the high intrathyroidal storage of iodine and performed hormone be extracted. Surgery as a treatment for thyrotoxicosis should be reserved for patients with severe IIT, where conservative treatment has been shown to be ineffective. Furthermore, in rare selected cases, when a rapid normalization is required, surgery without preoperative treatment seems to be justified. The effect of surgery was impressive in all our cases and there were only minor perioperative complications. Thus, it could be shown that subtotal thyroidectomy may be a rational and effective treatment in severe IIT which should be carefully considered and weighed against other types of therapy.

Adult↗
PubMed1985

[Maintenance of duodenal passage--yes or no?].

The importance of the duodenal passage in gastric surgery is still unknown. Most gastric procedures exclude the duodenum from food passage without severe postoperative problems. Based on our own studies we are able to demonstrate the importance of the duodenal passage for glucose homeostasis. Since most primary surgical procedures with duodenal anastomoses result in a higher operative risk, the procedures should not be used in primary gastric surgery. In dumping syndrome, however, restoration of the duodenal passage is a very effective surgical treatment.

Blood Glucose↗