Downregulation of tapasin expression in progressive human malignant melanoma.

Tumor cells with alterations in the MHC class I peptide-loading complex are unable to load peptide antigens onto MHC class I molecules. These alterations result in destabilization of MHC class I expression on the tumor cell surface and thus play a critical role in escape from immunological recognition by the acquired cellular immune system. By forming physical links between class I heavy chains and TAP molecules, a component of the class I peptide-loading complex, tapasin, plays an important role in the assembly of MHC class I molecules with peptides in the endoplasmic reticulum. In the present study, we compared 104 human melanoma lesions representing different stages of tumor progression for their expression of tapasin in tumor cells by immunohistochemistry. Tapasin downregulation was significantly associated with tumor progression. Whereas 100% of melanomata in situ and 96.2% of primary melanomas with a Breslow index of 0.75 mm as well as in 21.1% metastatic melanoma lesions. The downregulation of tapasin in advanced stages of human melanoma may reflect the accumulation of alterations in the antigen-presenting/processing machinery associated with neoplastic progression. These alterations may lead to failure of the acquired cellular immune system to control progression and metastatic spread of melanoma cells in vivo, and thus contribute to the immune escape phenotype of human melanoma cells.

[Sebaceous gland carcinoma of the neck]. / Zervikales Talgdrüsenkarzinom.

Extraocular sebaceous carcinoma is a rare skin neoplasm that resembles clinically pyogenic granuloma, hemangioma or squamous cell cancer. The clinical and histological findings are described. The differential diagnosis of common tumors of the face should include this rare malignancy.

[Lipoprotein and apolipoprotein electrophoresis in X-chromosome recessive ichthyosis]. / Lipoprotein- und Apolipoproteinelektrophorese bei X-chromosomalrezessiver Ichthyose.

BACKGROUND AND OBJECTIVE: The clinical differentiation of the hereditary ichthyosis forms is difficult and without laboratory markers hardly possible. Serum lipoprotein electrophoresis is one tool for detecting patients with recessive X-linked ichthyosis (XRI). Compared to controls, XRI patients show elevated electrophoretic mobilities of low density (LDL) and very low density lipoproteins (VLDL). This change in pattern is only partially explained by the increased LDL cholesterin sulfate concentration and is the subject of this study. PATIENTS/METHODS: Patients suffering from XRI and ichthyosis vulgaris, healthy controls. SDS-PAGE-electrophoresis and isoelectric focusing for detection of XRI-associated variations in apolipoproteins apo B-100, apo C-III and apo E. RESULTS: XRI-associated apolipoprotein variants were not found. In contrast to the literature, an increased electrophoretic mobility was also observed for HDL (high density lipoproteins) from XRI patients. CONCLUSIONS: The underlying cause of the increased electrophoretic mobility of VLDL and HDL in XRI patients remains unclear. Future studies should investigate other apolipoproteins and verify the cholesterin sulfate concentrations reported for VLDL and HDL from XRI patients.

Renal transplantation from donors aged < 6 years into children yields equal graft survival when compared to older donors.

Several articles have shown inferior renal allograft survival in patients receiving kidneys from young cadaver donors. We therefore assessed the survival and function of the first cadaveric graft from donors aged under 6 years of age, transplanted after 1983. The results were compared with the outcome of children receiving kidneys from older donors. Graft survival and serum creatinine were analyzed retrospectively at various time intervals after first cadaveric transplantation in 35 pediatric recipients of renal transplants grafted between 1983 and 1996 from donors < 6 years of age. Their data were compared with those of 167 pediatric recipients of renal transplants grafted from older donors. The proportion of young donors remained constant throughout the observation period. Mean recipient age was 10.4 years (range 3.2-17.5 years) in the patients grafted from donors < 6 years of age, not much different from the mean age of the donors in the 6+ years group (12.5 years, range 2.3-18.6 years). Five-year patient survival did not differ between the two groups (89 vs. 90%). In 1983-1996, graft survival rate of kidneys from donors aged < 6 years after one year was 77% (donors aged 6+ years=76%), after 2 years 66% (donors aged 6+ years=68%), after 3 years 62% (donors aged 6+ years=66%), and after 5 years 55% (donors aged 6+ years=60%, n.s., Log-rank test). In 1994-1996, 2-year graft survival was 88% (controls 91%, n.s.). In children receiving a cadaveric graft from a donor aged < 6 years, mean serum creatinine fell from 132+/-101 (SD) micromol/l after 3 months to 101+/-66 micromol/l after 12 months, and was 110+/-52 micromol/l after 5 years. This compared with a serum creatinine of 131+/-108 micromol/l after 3 months, 132+/-97 micromol/l after 12 months and 143+/-81 micromol/l after 5 years in children receiving grafts from older donors. When transplanting renal allografts from young donors into children, there was no significant difference in graft survival between donors aged < 6 years and older donors or in graft function. We conclude that good results from young donors can be obtained in a specialized center, and therefore the restriction of kidney selection to donors aged > 6 years may not be justified.

Malignant tumours after renal transplantation.

In 1243 patients after renal transplantation, 39 malignant tumours were detected in 37 patients. The average latency period between transplantation and tumour disease was 72 months. Tumours included 8 malignant lymphomas, 7 dermatomas and 24 visceral tumours. The patients who developed a tumour had received fewer blood transfusions before transplantation than a tumour-free control group of 60 patients with renal transplants. Rejection crises occurred in a significantly smaller number of tumour patients compared with the control group.

[Complications of laparoscopic interventions in urology]. / Komplikationen laparoskopischer Eingriffe in der Urologie.

From April 1987 to November 1995, we performed 741 laparoscopic procedures, in which we observed 14 major complications (1.9% complication rate). The complication rate was 4% in the first 100 procedures--more than twice as many as in the following 631 procedures, which had a complication rate of 1.6%. Although between 1987 and 1990 laparoscopy was mainly used for the diagnosis of cryptorchidism, we then progressed to therapeutic measures with the help of the laparoscopic technique. After performing laparoscopic orchiectomy (1990), we introduced fenestration of lymphoceles (1991), varicocelectomy (1991), pelvic staging lymphadenectomy (1992), nephrectomy (1992), and adrenalectomy (1994) into clinical practice, in addition to other, more rarely occurring procedures. The complications we observed demonstrate a clear learning curve and show that critical, gradual practice of the laparoscopic technique is necessary.

Comparison of different methods of treating varicocele.

Varicocele treatment was performed in 331 patients. One hundred fifteen patients were operated upon according to the technique of Bernardi (1947), 80 patients underwent occlusion of the testicular vein by detachable balloons, 47 patients were treated with percutaneous sclerotherapy, and 89 patients underwent laparoscopic varicocele treatment. The laparoscopic occlusion of the testicular vessels was done in two different ways: (1) coagulation of the testicular veins with electrocoagulating tweezers, and (2) occlusion of the suprainguinal testicular vessel with metal clips and transection of the vessels. Laparoscopic Group 1 showed a clearly higher complication rate and recurrence rate in comparison with the other methods, whereas in Group 2 we observed the best results with only 4% complications and recurrences. Because of its higher complication rate and recurrence rate, laparoscopic electrocoagulation of the testicular veins proved to be inadequate.

Laparoscopic laser ureterolithotomy.

With the introduction of laparoscopic operating techniques in urology, this new minimally invasive method can now be used in the treatment of problematic calculi in the ureter. We report our first experience with laparoscopic laser ureterolithotomy.

Cranial granular-cell tumor of the trigeminal nerve. Case report.

Granular-cell tumors are exceedingly rare neoplasms in the central nervous system. Their histogenesis has been a subject of longstanding controversy but substantial findings support the current theory of a Schwann cell origin. Other recent histopathological studies point to an astrocytic origin in those tumors which arise from the cerebral hemispheres. A case of a granular-cell tumor arising from the trigeminal nerve is described. The origin, clinical course, radiological features, and treatment of such unusual intracerebral tumors are discussed.

[Basic research in cardiology]. / Grundlagenforschung in der Kardiologie.

Phosphorylation of phospholamban and troponin I of dog hearts was measured depending on the cardiac cycle. Myocardium biopsies were obtained with the help of an ECG-triggered cryobiopsy device. A standardized back phosphorylation technique was performed with (32P)ATP and an excess of exogenically applied c-AMP dependent protein kinase, which was followed by electrophoretic fractionation. This standardized method enables quantitative measuring especially of the c-AMP-stimulated protein phosphorylation. A dichotomous behaviour in the phosphorylation of troponin I and phospholamban was detected in the cardiac cycle. Like c-AMP and the c-AMP depended protein kinase troponin I reach a maximum phosphorylation in the systole. In contrast to this, phospholamban in vivo shows the highest degree of phosphorylation in the diastole and drops to a significant lower value (by approximately 25%) in the systole. The surprising dichotomy support the assumption that the Ca-detensivation of the contractile proteins by phosphorylation of troponin I was a dynamic counterregulation in the presence of a high Ca-level takes effect before the Ca-accumulation which can be stimulated by phospholamban. The results show that covalent modifications of regulatory proteins come to pass in the ms-range and have to be considered in distinctive conditions of myocardial function.