Biomedical subjects
K Nagel
Publications and source records attributed to K Nagel.
[Perfusion of the extremities in malignant melanoma. Indication, technic and results].
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Miniature equipment for the perfusion of rat limbs.
A simple, reliable and efficient miniaturized extracorporeal circulation system for the use in small animals, especially for the perfusion of rat hind limbs, has been described. The system consists of a newly devised bubble oxygenator and heat exchanger and of commercially available roller pumps, polyethylene cannulas and silicone tubes. The minimal and maximal priming volume of the entire system is 4.7 and 16.7 ml, respectively. The efficiency of the system is reflected in a high value of oxygen uptake in the range of 0.061 ml O2 X min-1 X ml-1 blood, a heat transfer coefficient ranging from 0.96 to 0.31 at flow rates between 1 and 20 ml X min-1, a low pulsation amplitude of the roller pump, a constant flow resistance at the arterial cannula, which implies optimal flow conditions, and in a low blood trauma with plasma hemoglobin concentrations of 47.5 +/- 5 mg dl-1 after 60 min of in vitro perfusion.
[Liver CT with portal vein administration of a contrast medium].
Contrast administration through the superior mesenteric or splenic arteries provided additional information in 22 out of 31 patients, when compared with intravenous contrast bolus for CT of the liver. In 11 patients, the demonstration of a tumour lead to a change in treatment. False positive findings occurred in four of the 31 patients. In 2 patients intrahepatic lesions were overlooked, but were found during angiography carried out at the same examination. The diagnosis of intrahepatic space-occupying lesions is discussed as well as the CT appearances of portal-venous liver perfusion.
[A new model for the regional perfusion of the extremities in rats: metabolism and hemodynamics].
A pelvic extremity of the rat was recirculatorily perfused by means of a self-developed perfusion equipment in a perfusion pressure of 65 +/- 6 mmHg and a blood temperature of 35 degrees C during one hour. Tissue specimens were taken away in the end of the perfusion and 3 weeks later and the metabolite contents was determined in comparison with control groups. No change of the metabolite status was provable by the perfusion. The technical practicability of the perfusion of rat extremities could be shown, therefore, contrary to hitherto existing assumptions.
[Crohn disease and squamous cell carcinoma of the anorectal transition].
Squamous cell carcinoma of the anorectal junction originated from anal fistulas in two female patients with Crohn's disease which have been suffering from anal and rectovaginal fistulas for many years. In addition one tumour showed paraneoplastic parathyroid hormone synthesis. This findings point out Crohn's disease as a premalignant lesion. Chronic fistulas associated with Crohn's disease must be followed up carefully by clinical examination, endoscopy and biopsy. To prevent malignancy and to cure the anal region and the origin of such fistulas, resective surgical technics should be taken into consideration early.
[Technic of surgery of soft tissue tumors of the lower extremities].
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[Malignant melanoma of the anorectum].
Malignant melanoma of the anal canal in stages I, II and III, respectively, was diagnosed in a 58-year-old woman and two men, aged 69 and 73 years. The patients' age was thus above the average reported age of manifestation (60 years) of this tumour. In two patient the tumours had been incorrectly diagnosed because of their proximity to the linea dentata and their similarity to haemorrhoids: operation had been delayed for four and about six months, respectively. Treatment of choice for stages I and II was abdominoperineal amputation of the rectum, while in the patient with stage III a colostomy was performed as a local palliative measure. The patients with stage II and III tumour died after six and 12 months, respectively, a survival time which corresponds to that expected from published series. Radiotherapy did not influence tumour growth in the patient in stage III. The patient in stage I has been free of tumour for six months.
An automated fluorescence assay for subnanogram quantities of protein in the presence of interfering material.
An automated assay for measuring nanogram and subnanogram quantities of protein in microliter samples was developed with the fluorometric reagent omicron-phthaldialdehyde/mercaptoethanol. Low molecular weight interfering substances were separated within the analysis by gel filtration. The technique allowed measurement of biological fluids without any sample pretreatment. The method presented proved to be linear within the range 1.2 ng to 1.4 microgram with a standard deviation of +/- 4.2%. The minimum detectable protein concentration was 1 microgram/liter. Special care was taken to prevent any determination errors caused by losses of protein during adsorption to surfaces. The simple analytical apparatus constructed can be used for field studies and ran several weeks when continuously used for seawater analysis aboard ship.
[Indole melanogens--useful tumor markers in malignant melanoma?].
The concentrations of indole melanogens have been measured in 24-hour urine samples of 44 patients suffering from malignant melanoma, clinical stages I to IV, and 23 healthy test persons (control group). With regard to the controls, the urinary concentration of indole melanogens amounted to 3.8 +/- 1.329 micrograms/ml; the excretion was 5.41 +/- 1.941 mg daily. In patients with localized malignant melanoma, the concentration of indole melanogens did not differ from the control group. Highly significant levels, however, were measured in patients with generalized disease (7.76 micrograms/ml and 6.85 mg daily). Tyrosin orally given (7 g on the 2nd, 3rd, and 4th day of the collecting period) did not elevate the urinary excretion of indole melanogens in any of the test groups. These results indicate that the applied procedure does not present any fundamental advantage for clinical oncology.
[Current status of therapy of liver metastases of colorectal carcinoma].
Surgical removal of liver metastases stemming from colo-rectal carcinoma is the therapy of choice of this disease. Postoperative mortality is 8%, 5 years survival rate ranges between 22 and 52% and can be considered to be good. However in 85% of patients surgery is not possible because of widespread involvement of the liver. Systemic chemotherapy yields remission rates up to 23% without increase of survival time, and therefore is no real alternative. Infusion of cytostatic drug into the hepatic artery yields better results, e.g. remission rates up to 85% and average survival times up to 26 months.
A prospective randomized study of regional extremity perfusion in patients with malignant melanoma.
One hundred seven patients presenting with malignant melanoma of the extremities were included in a prospective randomized study, which was conducted to evaluate the effectiveness of adjuvant hyperthermic regional cytostatic perfusion. In a control group (A, N = 54) the tumors were excised widely and the regional lymph nodes were dissected. The patients in the second group (B, N = 53) received additional hyperthermic (42 C) perfusion with melphalan. The mean follow-up observation period was 554 days. We chose the disease-free survival time as the criterion for success. The study could be discontinued prematurely, since the intermediate evaluation revealed a highly significant difference between the groups (p = 0.0001). We observed 21 local recurrences in the control group and four recurrences in the perfusion group. The retrospective breakdown by clinical stages also showed significant differences. The recurrence rate in the control group was 27.8% in Stage I, 31.6% in Stage II, and 58.8% in Stage III. In the perfusion group we observed recurrences equaling 5.6% in Stage I, 5.5% in Stage II, and 12.5% in Stage III. The differences between the groups based on the target-criterion of disease-free survival represent significance levels of p = 0.09 in Stage I, p = 0.03 in Stage II, and p = 0.003 in Stage III. We feel that on the evidence provided by our study, shown in the above results, the adjuvant application of regional hyperthermic cytostatic perfusion has proven itself to be superior to conventional procedures alone.
[Regional hyperthermic cytostatic perfusion as an alternative in the treatment of malignant soft tissue tumors of the extremities].
From March 1979 through December 1983, 15 patients with soft-tissue sarcomas of the extremities were treated by a local excision and an adjuvant regional hyperthermic cytostatic perfusion. Reversible edema in two patients was the only post-operative complication. 14 patients were disease-free after a median follow-up period of 24.2 months. One female patient developed a local recurrence 10 months following surgery. Based on our results and long-term studies of several authors, the adjuvant regional perfusion appears capable of successfully treating patients with soft-tissue sarcomas of the extremities.
[Primary malignant melanoma of the esophagus].
Two case reports are given of patients suffering from malignant melanoma of the esophagus, which occurs very rarely. In both patients the leading clinical symptom was dysphagia. Diagnosis was confirmed by endoscopy and biopsy, and surgery was done. One patient died within 3 weeks from pneumonia, the second patient is alive 3 months after resection of the tumor and is free of symptoms.
[Surgical therapy of malignant soft tissue tumors].
Soft-tissue sarcomas are rare neoplasms originating from the extraskeletal connective tissues of the body. The GTNM-system is recommended for clinical staging. The most effective treatment are radical surgery and the combination of limited surgical removal and high-dose irradiation. In the management of soft-tissue sarcomas of the extremities the isolated hyperthermic perfusion is a successful adjuvant to excision for saving a tumour bearing limb.
Isolated liver perfusion in dogs.
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[Liver tumors caused by thorotrast. Case report].
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