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Biomedical subjects

H D Becker

Publications and source records attributed to H D Becker.

At least 181 records · Page 10Linked to original sources

[Minimally invasive surgery of the colon and rectum].

In the period from 1.8.89 to 1.7.92 140 adenomas and 63 carcinomas were locally resected from the rectosigmoid area with the instruments of TEM. The mortality was 0.5%, the rate of dehiscence of the suture 9.8%. 75% of these were treated conservatively. One of the 29 patients with locally resected pTl-low risk-carcinoma developed a recurrence so far. The rate of recurrent adenomas was 1.4%. From 7.1.1992 to 24.5.1993 21 procedures in colorectal surgery were performed laparoscopically or in a combined laparoscopic transanal operation. The mortality was zero. 1 case of suture dehiscence, 2 cases of crural phlebothrombosis and 1 lesion of the left ureter were observed. The use of TEM in the combined procedure means an extension of the range of minimally invasive colorectal surgery to the lower rectum.

Adenocarcinoma↗

[Hereditary thrombophilia as a cause of recurrent transplant thromboses].

We report a case of hereditary protein S and protein C deficiency which are a rare defects of the anti-coagulation-system. Protein S is a vitamin K dependent glycoprotein that functions as a cofactor to activated Protein C in the inactivation of coagulation factors V and VIIIa. A deficiency of these proteins caused by a genetic defect increase the risk of recurrent thrombosis at a younger age. Acquired decreases in protein S and C concentration have been reported in connection with age, sex, pregnancy and with oral anticonception. The higher risk for thrombotic diseases of patients with thrombophilia requires a sufficient treatment and prophylaxis, e.g. with fresh frozen plasma or a protein C concentrate.

Adult↗

[Endoscopic argon gas coagulation--initial clinical experiences].

Argon-gas-coagulation represents a new method of contact free electrocoagulation, where RF-energy is applied to the tissue by means of ionized argon-gas. In the operative field argon-gas-coagulation has been used with success for hemostasis in several parenchymatous organs and for devitalization of various tissues. Experimental studies have shown the superiority of argon-gas-coagulation over standard electrocoagulation and surgical techniques due to its high efficiency and limited tissue traumatization. Having developed and designed special endoscopic probes and after in-vitro-studies we could utilize the method in flexible endoscopy as well. From June 1991 to September 1992, 102 patients were treated in 189 sessions with argon-gas-coagulation in the upper and lower gastrointestinal tract as well as respiratory system. The indications were: malignant and benign tumors, diffuse hemorrhages of various origins and of various sites, tissue overgrowth after stent-implantation, remaining tissue after endoscopic adenomectomy and conditioning of fistulas prior to fibrin sealing. In all cases argon-gas-coagulation in flexible endoscopy has been shown to be a very effective and easy to perform technique with advantages in comparison to standard electrocoagulation. Problems and complications have not been observed. The limited depth of tissue penetration (2-3 mm) coincident with efficient tissue coagulation allows the application even in critical areas such as the duodenum or colon. In many indications argon-gas-coagulation has replaced the former widely used Nd-YAG-laser in our unit. Except vaporisation of extended tumors, the argon-gas-coagulator shows remarkable advantages for nearly all applications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenomatous Polyposis Coli↗

[The results of the endoluminal high-dose-rate irradiation of central non-small cell bronchial carcinomas].

Between November 1987 and July 1991 34 patients with a non-small-cell lung cancer were treated with an endobronchial iridium-192 high-dose-rate afterloading therapy. In 13 patients with relapses after percutaneous irradiation brachytherapy was the sole radiotherapy modality with 20 (5 to 29) Gy within 14 (one to 42) days in four (one to six) fractions in a palliative sense. Endoscopically controlled, seven remissions (four complete, three partial) could be achieved. The median duration to local progression was two months, the median survival of this group was nine months. In 21 patients with a medically or surgically unresectable tumor a combined percutaneous (51 [46 to 60] Gy within 4.5 to six weeks) and endobronchial irradiation was done. This patient group consisted of one stage IV, eight stage IIIb, 8 stage IIIa, 1 stage II, 1 stage I patients and two patients with tumor relapses after surgery. Patients were selected for combined therapy by a mostly endo/peribronchial tumor volume. The brachytherapy was applied after an interval of 16 (one to 48) days with 17.5 (9 to 20) Gy in three to four fractions. In 13 patients six to eight weeks after treatment a complete remission by endoscopy was found. Patients with a complete remission had a statistically better survival than the remaining patients. The median estimated survival of this group until local progression was 16 months, the median survival 20 months. In all patients there were two occurrences of hemorrhage (one group I, one group II) and one tracheo-mediastinal fistula (group II), but in no case of these fatal events a local tumor control had been reached. In three patients radiogenic bronchitis occurred up to a degree, which demanded endoscopic interventions. This study suggests, that there might be a subgroup of centrally located lung cancer with endo/peribronchial tumor mass, which gains by a combined radiation treatment with an acceptable risk of side effects. The results should be evaluated in further randomized studies.

Adult↗

Secretion of protein and epidermal growth factor (EGF) by transplanted human pancreas.

Epidermal growth factor (EGF) has been localized in human salivary and Brunner's glands and found to stimulate the proliferation of gastrointestinal and pancreatic tissues in animals, but little is known about EGF in human pancreas. This study was designed to determine the distribution and release of EGF in the pancreas and to assess the secretion of EGF and protein by the transplanted human pancreas. The peroxidase antiperoxidase (PAP) immunocytochemical method with anti-hEGF showed that EGF was restricted mainly to the excretory cells lining pancreatic ducts. The EGF immunoreactivity in the pancreatic tissue averaged about 15 +/- 0.5 micrograms/g of tissue wt. The concentration and output of EGF in the pancreatic juice were, respectively, about 3.4 +/- 0.7 ng/mL and 68 + 12 ng/h in basal secretion collected from the whole pancreatic transplant. A significant increase in EGF release from this transplant started about 2 h after its reperfusion and was accompanied by a parallel increase in protein output. Injection of iv secretion (1 U/kg) resulted in a transient rise in EGF output, probably as a result of washout by increased vol flow, whereas HCCK (1 U/kg) caused more prolonged release of EGF accompanied by a marked stimulation of protein secretion. Ingestion of a mixed meal caused an immediate and sustained increment in EGF output, and protein output showed a more protracted increase, reaching its peak in the second postprandial hour. Fractionation of an extract of pancreatic juice on G-5O Sephadex superfine column revealed that EGF immunoreactivity emerged as a major peak in the same position as authentic human EGF (hEGF).(ABSTRACT TRUNCATED AT 250 WORDS)

Cholecystokinin↗

Technique and results of transanal endoscopic microsurgery in early rectal cancer.

The anatomy of the pelvis makes it difficult to perform local excisions in the rectum when the tumor is some distance from the anal verge. We have, therefore, developed a new minimally invasive technique for tumor resection. A rectoscope with a 40-mm diameter permits tumor resection under stereoscopic control in the gas-dilated rectal cavity. Excisions in full-thickness technique up to segmental resections with end-to-end anastomosis can be performed. In selected cases, local excision of a small rectal cancer can be regarded as appropriate treatment. However, most local resections of carcinomas are performed when removal of an adenoma is planned, and the postoperative histology shows a carcinoma. Since 1983, we have operated on 326 patients, 274 who have been enrolled in a prospective clinical trial. Definitive histologic examination proved that 74 of these tumors were carcinomas. The rate of severe complications in patients with carcinomas was 9%, and the mortality rate was 0%. The advantages of this new technique are: The stereoscopic magnified view in the gas-dilated rectum allows precise surgery in an operative field that is otherwise difficult to reach. During the postoperative period, minimal discomfort and pain result in a short hospitalization.

Adenoma↗

In vitro fragmentation of gallstones with lithotriptors for use in laparoscopic cholecystotomy.

In preliminary in vitro experiments, five different lithotriptors for use in laparoscopic cholecystotomy were tested to determine the fragmentation time and rate of a defined group of gallstones. The Alexandrit laser and the ultrasonic lithotriptor were too ineffective to warrant further investigation. In phantom tests with pig gallbladders, the pulsed dye laser and the electrohydraulic lithotriptor had a fragmentation rate of 100%, but the rate of clearing of the gallbladder was 0% as stone debris always remained in the gallbladder. The clearing rate of the RotoLith mechanical lithotriptor was 84.6%. The RotoLith lithotriptor was the most effective device because the stones were ground into such small particles that they could easily be rinsed out of the gallbladder. As the RotoLith procedure does not need to be monitored optically, the opening of the gallbladder need not exceed 3 mm compared to 10 mm for the other lithotriptors. This makes closure of the gallbladder safer and it would seem feasible to perform the procedure using the RothoLith lithotriptor under local anaesthesia.

Animals↗

The laparoscopic approach to modified Taylor's procedure in the treatment of chronic duodenal ulcer: an improved technique.

Laparoscopic modified Taylor's procedure for chronic duodenal ulcer was performed in three patients. A new, specially developed combination instrument allowed the operation to be performed easily, sometimes using only four introduction sites. Coagulation, suction, and rinsing can be performed at the same time, and the hook knife, scissors, or different forceps can be introduced through the operating channel of the instrument. An overcast seam to approximate the seromyotomy was done using the technique developed for transanal endoscopic microsurgery. Instead of the silver clips, specially handmade steel and titanium clips were used to fix the PDS suture. No major postoperative complications occurred. The gastric acid output under basal condition and stimulation showed a decrease ranging from 47% to 79%. Endoscopic examination performed on the 4th postoperative week showed complete recovery in all cases.

Adult↗

[Endoscopic sonography of the anorectum in inflammatory rectal diseases].

213 patients, classified in 3 groups, were examined in a prospective trial using endorectal ultrasound. 80 patients (group A) had no anorectal disease, the endorectal ultrasound showed normal structures of the anorectum and the perirectal tissue. 80 patients (group B) suffered from Crohn's disease, 30 of them had no clinical signs, the rest of this group (50 patients) felt pain in the anal/perianal region. 83 patients (group C) had perianal abscesses or fistulas, Crohn's disease could be excluded. In all 64 perianal fistulas and 66 perianal abscesses were diagnosed. The results of the rectal-proctological examination were compared with endorectal ultrasound. 100% of the perianal abscesses could be recognized using endosonography. The digital-proctological examination revealed only 57% of perianal abscesses and 48% of perianal fistulas; the supralevatory abscesses couldn't be detected proctologically at all. By endorectal ultrasonography we obtained useful informations about localization and extension of the inflammatory process. From a therapeutic and prognostic view the endorectal ultrasound is a simple, practicable and useful method to investigate perianal and anorectal diseases.

Abscess↗

[The management of exocrine pancreatic secretion--a central problem of allogeneic pancreas transplantation].

In a consecutive series of 47 pancreatic transplantations, the duct occlusion technique and the bladder drainage technique are evaluated. Major problems, when using the duct occlusion technique are pancreatic fistulae with secondary infections and bleedings. Early postoperative graft thrombosis remains a crucial problem. Finally, graft rejection can not be diagnosed in time when using the duct occlusion technique. In contrast, the bladder drainage technique guarantees an absolutely safe management of the exocrine pancreas secretion. The risk of early postoperative graft thromboses reaches nearly zero. In addition, by monitoring urinary amylase and thereby the function of the exocrine pancreas, rejection episodes can be diagnosed very early. Early postoperative graft pancreatitis of the bladder drained pancreatic allografts remains a significant problem. In addition due to excessive bicarbonate loss via the urine oral bicarbonate substitution is necessary. A high incidence of urinary tract infections as well as unspecific irritations of the urinary tract are further drawbacks of the bladder drainage technique. They can be managed, however, relatively easily. Since using the bladder drainage technique, 1-year-graft-function rate of the pancreatic allografts increased by more than 40% and reaches now 88%. The new operative technique represents the best surgical procedure for control of the exocrine secretion of pancreatic allografts at the moment. Simultaneous pancreas-/kidney transplantation in the technique described can therefore be recommended a selected group of type-I diabetics with end-stage renal disease as the therapy of choice.

Adolescent↗

[Pancreatic transplantation: success and problems].

The results of pancreatic transplantation could be improved markedly since using the bladder drainage technique. The best function rates can be achieved when transplanting simultaneously a kidney from the same donor. In our own series of 50 combined pancreas-/kidney transplantations (CPKT) the 1-year-graft function rate for both organs reaches 88%. The drainage of the exocrine pancreatic secretions into the urinary tract leads, however, to a high incidence of recurrent urinary tract infections. Diagnosis of rejections after combined pancreas-/kidney transplantation is mainly based on the function of the simultaneously transplanted kidney and the exocrine secretion of the pancreatic graft. In spite of triple drug therapy (prednisolone, azathioprine, cyclosporine A) and ATG (antithymocyte globulin) prophylaxis the incidence of acute rejection episodes is initially high. For rejection therapy monoclonal antibodies, such as OKT3, are most effective. Glucose metabolism is almost completely normalized after successful pancreatic transplantation. Considering late diabetic complications, however, only positive effects on diabetic neuropathy are confirmed. This is probably due to the very late onset of therapy by pancreatic transplantation. A significant improvement in other late diabetic complications can only be expected in long term follow up studies. The positive effect on physical and psychological rehabilitation, however, improves the quality of life in most of the patients after CPKT substantially. Even though the results of isolated pancreatic transplantation reaches 1-year-graft function rates of approximately 60% in single centers, the indication to this treatment should consider the disadvantages of long term immunosuppression and the uncertain results considering secondary complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined Modality Therapy↗

[Prognostic factors in Crohn's disease. Is the probability of a later operation assessable at the initial diagnosis?].

Data were retrospectively analysed of 492 patients (268 women, 224 men; mean age 27 [9-71] years) to find out what features present at time of first diagnosis (age, sex, site of disease, biochemical findings) will play a role in determining the probability of surgery ultimately becoming necessary. The probability of an operation ten years after first diagnosis was 55%, after 20 years it was 88%, significantly higher if the ileum rather than only the colon was affected. Age and sex had no influence. Patients with a haemoglobin content below 12 g/dl (women) or below 13.5 g/dl (men), or an albumin concentration under 4.0 g/dl, or a blood sedimentation rate over 30 mm in the first hour had a probability of operation after ten years nearly three times higher than those without one of these findings. A prognosis about the likely future course of the disease can be made from its localization and the biochemical values. Thus patients with an early ileocolitis and unfavourable biochemical findings apparently constitute a subgroup in which the disease takes a primarily aggressive course.

Age Factors↗

The development of osteosarcoma in four-fold selected group of patients.

Patients with osteosarcoma have been submitted to four-fold selection using parameters previously shown to be associated factors. These are sex, age at onset, haptoglobins and histological type. Further data have been added to the final resulting sequence of patients. In the four-fold selected group there is an age-dependent AB0 distribution which confirms the relevance of the criteria used and, consequently, the influence on sarcoma development. It can be assumed from these investigations that the occurrence of osteosarcoma is modified by several genetically fixed factors (HP type, sex, AB0 group).

ABO Blood-Group System↗

[Primary hepatocyte cultures as a model of experimental study of liver preservation].

Primary hepatocyte cultures have been used to evaluate data concerning hypoxic liver cell injury. To show the suitability of this method in liver preservation studies hepatocyte cultures were incubated under different conditions: warm normoxia (37 degrees C, pO2 greater than 70 mm Hg), warm hypoxia (37 degrees C, pO2 less than 0.1 mm Hg), cold normoxia (4 degrees C, pO2 greater than 70 mm Hg) and cold hypoxia (4 degrees C, pO2 less than 0.1 mm Hg). Incubations were performed in Euro Collins solution (EC), University of Wisconsin solution of Belzer (UW) and histidine ketoglutarat tryptophan solution of Bretschneider (HTK) as well as in Krebs Henseleit buffer (KH) for control incubations. During 12 h of incubation hepatocyte cultures under warm normoxia lost viability continuously in EC, UW and HTK while in KH they remained stable. Under warm normoxia all cultures lost 50% of their viability during 12 h of incubation while in cold normoxia loss of viability was mild but significant. Under cold anoxia which is the standard condition of liver preservation the cultured hepatocytes remained unchanged for 12 h in KH, UW and HTK, while in EC most of the cells were dead after 6 h. It is concluded that incubations of primary hepatocyte cultures under different pO2 and temperatures are well suited to contribute to liver preservation studies on a preclinical level and thus may help to save animal experiments.

Animals↗