Transplantation of embryonic retina to the subretinal space in rabbits.

Embryonic rabbit retina can be transplanted to the subretinal space of adult rabbit with a new method, which gives a high rate of successful short-term transplants. Embryonic (stage E 15) neural retina cells were injected through an incision just behind the sclerocorneal border with a thin (inner diameter 0.15-0.4 mm, outer diameter 0.3-0.5 mm) plastic tube attached to a specially designed instrument, by which the length of the protruding plastic tip could be controlled. The retina was penetrated from the vitreous side and the donor tissue was injected into the subretinal space. The cells survived in the host for at least 5 months, although the long-term survival rate tended to decrease. The transplanted cells matured and differentiated, forming an approximation of the layered, retinal structure with some anomalies (e.g. rosettes). The subretinal location offers an interesting and convenient way of studying the development of retinal cell transplants in rabbits. Large transplants can be produced, and the risk for failures due to erroneous vitreous placement is small.     

The effect of physical training on rat calf muscle, oxygen tension, blood flow, metabolism and function in an animal model of chronic occlusive peripheral vascular disease.

The effect of treadmill physical training (PT) on rat gastrocnemius/plantaris muscle after bilateral femoral artery ligation was investigated. To enable a comparison to be made between the susceptibility of muscles with restricted blood flow and normally perfused skeletal muscle to PT, animals without ligated femoral arteries also underwent PT. PT increased the oxidative capacity of the gastrocnemius/plantaris muscle, as judged by the activity of citrate synthase, and reduced muscle fatigue in both groups of animals. Exercise also tended to lower the activity of a marker enzyme for glycolysis, glyceraldehyde-phosphate dehydrogenase in all animals, although this only reached the level of statistical significance in the animals with ligated femoral arteries. In the animals with restricted muscle blood flow, PT increased gastrocnemius skeletal muscle blood flow and pO2 and prolonged the time taken to attain maximum muscle twitch tension. The results indicate a great susceptibility of hindlimb skeletal muscles of rats with ligated femoral arteries to PT. They also suggest that the beneficial effect of PT observed in man with chronic occlusive arterial disease (COAD) may result both from an increase in muscle blood flow and from an enhanced mitochondrial respiratory activity in the afflicted muscle.     

Quantification of aortic valvular insufficiency by MRI

Flow-encoded MRI sequences nowadays allow a quantitative evaluation of blood flow in any slice position. For the first time there is the possibility of determining quantitatively the volumes of both left ventricular ejection and regurgitation over the aortic valve in a non-invasive ways, thus obtaining the regurgitation fraction as a reliable measure for the evaluation of aortic valvular insufficiencies. The quantitative assessment of aortic valvular insufficiencies was carried out by MRI and compared with the diagnosis by means of Doppler ultrasound and in some cases by cardiac catheter also. The new MRI method is characterized by a good correlation with the clinical grading of aortic valvular insufficiencies. It should be possible to develop a new non-invasive standard for quantifying aortic valvular insufficiencies. Correspondence to: G. Engels     

Quality assessment and assurance in diagnostic imaging. Theoretical and practical considerations and a quality audit of the excretory urogram

Concepts necessary to an understanding of the basics of quality assurance audits are presented. Included are specific examples that bridged theory and practice by applying the protocol to a real-life diagnostic imaging situation. This method meets the present requirements of the Joint Commission of the Accrediation of Hospitals.     

Papierchromatographische histaminbestimmung im tonsillengewebe

Zusammenfassung Es wird über den papierchromatographischen Histaminnachweis im Tonsillengewebe berichtet. Die hier angewandte Untersuchungsmethode stellt eine Modifikation des von Yamanishi u. Mitarb. angegeben freshness-test dar. Nach Erörterung der Schwierigkeiten des Histaminnachweises im Gewebe, werden die eigenen Ergebnisse in zwei Versuchsreihen dargestellt, wobei jede Versuchsreihe einem anderen Papierausschnitt entsprach. Das gesamte Tonsillenmaterial wurde in drei Gruppen eingeteilt: Der Durchschnittswert an Histamin pro 2 g Tonsillengewebe betrug danach für die Gruppe der hyperplastischen Tonsillen von Kindern und Jugendlichen 15,8 g, für die Gruppe der chronisch entzündeten Erwachsenen-Tonsillen ohne Focusverdacht 13,0 g und für die Gruppe der chronisch entzündeten Tonsillen von Erwachsenen und Kindern mit Focusverdacht 17,1 g Im Anschluß an die Ergebnisse wird noch auf die Problematik des Histaminstoffwechsels in der Tonsille eingegangen.

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Determination of histamine in tonsils by paper chromatography

Summary A modified method given by Yamanishi and his co-workers to determin the presence of histamine in tonsil tissues was described. Results were depicted into two series of tests, each series corresponds to another paper chromatography section.The average value of histamine per 2 g of tonsil tissues amounted to 15.8 g for the first group of hyperplastic tonsils of children and young people, to the second group 13.0 g of chronically inflamed tonsil of adults without suspicion of focus, and 17.1 g for the third group of chronically inflamed tonsils of adults and children with suspicion of focus.An account of histamine metabolism in tonsil is also discussed.

     

Application of adjuvant chemotherapy in colorectal cancer -- a survey in the region of Essen, Germany

BACKGROUND: The value of adjuvant chemotherapy (AC) in colorectal carcinoma (CRC) is definitely proven and its application is clearly recommended by the German Cancer Society (GCS). The goal of this study was to investigate whether these findings and recommendations have been introduced in daily practice and whether this might depend on the specialization of the treating physicians. PATIENTS AND METHODS: Patients presenting with CRC in the department of oncology of the Kliniken Essen-Mitte between 1997 and 2002 who had started AC until the end of 2001 were evaluated. Data on AC were collected retrospectively from patients' records and prospectively by patient interviews. We investigated whether the guidelines of the GCS were followed and whether 5-fluorouracil (5-FU) was applied properly and we correlated the results with the treating institution. RESULTS: 133 patients were analyzed for correlation of their treatment with the guidelines of the GCS. In 81% the AC met these guidelines. This was significantly more frequent in oncologic institutions than in non-specialized ones (96 vs. 9%, p < 0.001). Regarding dose and infusion time chemotherapy was properly administered to 83% of the patients (109/132) treated with 5-FU. Again, correct treatment was significantly correlated with specialization of the physicians (98 vs. 9%, medical oncology vs. other, p < 0.001). CONCLUSIONS: The results of our random search in the region of Essen, Germany, lead to the hypothesis that a quality-assured chemotherapy is best provided by specialized oncologic institutions, even if the treatment has been established for years. This should be proven by a large epidemiologic study.     

Vasopressin-independent regulation of collecting duct aquaporin-2 in food deprivation

BACKGROUND: Humans and animals are frequently subjected to food deprivation or starvation. However, the adaptation of the kidney to this condition is not well understood. The purpose of these studies was to examine the effects of food deprivation on water handling by the kidney, the expression levels of collecting duct (CD) water channel aquaporin-2 (AQP2), and to determine the role of vasopressin in the adaptation of AQP2 to food deprivation. METHODS: Sprague-Dawley (SD) and Brattleboro rats were placed in metabolic cages and deprived of food but had free access to water for 72 hours. Water balance and urine osmolality were measured daily. Kidney tissues were isolated and examined for the expression of AQP2 using semiquantitative immunoblotting and Northern hybridization. The circulating level of vasopressin and the mRNA expression levels of its precursor were determined by radioimmunoassay and Northern hybridization, respectively. RESULTS: In SD rats, the first 24 hours of food deprivation is associated with a significant polyuria and decreased urine osmolality (Uosm). This correlated with a significant down-regulation of AQP2 in the cortex and outer medulla. After 72 hours of food deprivation, Uosm increased above baseline, and urine volume dropped to a lower value. This was associated with a rebound increase in AQP2 expression in the cortex and OM and its up-regulation in the inner medulla. Interestingly, vasopressin mRNA expression and plasma levels were unchanged during food deprivation. Further, in homozygous Brattleboro rats, in which endogenous vasopressin is absent, food deprivation caused changes in urine volume, urine osmolality, and AQP2 expression, which are qualitatively similar to those observed in normal rats. CONCLUSION: Food deprivation impairs water handling by the kidney by causing dual changes in urine volume and urine osmolality. This effect is associated with parallel alterations in the expression of AQP2 and is independent of vasopressin activity. It is concluded that the increase in water reabsorption in the CD is an adaptive response of the kidney to a long period of food deprivation and is mediated via a vasopressin-independent mechanism.     

Colon perforation following percutaneous nephrostomy and renal calculus removal

Two patients had colonic perforation as a result of percutaneous nephrostomy placement followed by track dilatation and renal calculus removal. We present the technical aspects of nephrostomy placement and stone removal, as well as the clinical diagnosis and management of these cases. Both patients recovered well with conservative therapy and required no surgical intervention. This report reviews the anatomic considerations for percutaneous nephrostomy in patients undergoing renal stone removal.