No abstract

Selective breeding of miniature pigs bearing cutaneous tumours resulted in the establishment of the MeLiM strain with hereditary malignant melanoma. The inheritance of melanoma was tested in a two-generation kindred comprising 456 progeny from 78 li�ers. Melanomas were recognisable visually as black-pigmented lesions on the skin. Their size, shape, number, progression and metastatic spreading varied widely. All possible melanoma forms known in human melanoma, i.e. pigmented naevi, dysplastic naevi, superficial spreading melanoma and nodular malignant melanoma, were found in the MeLiM pigs. Because the occurrence of nodular malignant melanoma segregated in all recorded li�ers we have included only this form in the genetic analysis. The tumours were nodular with exophytic growth over the skin surface. All showed similar histopathological features, vertical growth to muscle fascia and high metastatic activity. We hypothesize, on the basis of segregation ratios obtained from various mating types, that the mode of inheritance of nodular melanoma in the MeLiM strain is probably controlled by three genes.

Total or partial renal ischaemia was studied in rats and pigs in a series of experiments, after total devascularization (ligature of renal vessels and ureter); ligature of isolated renal artery; experimental embolization of renal artery by non-resorbable material; devascularization of a specific renal segment by deep, strangulating sutures. Morphological studies showed that the resulting necrotization is represented most frequently by coagulation necrosis, less frequently by colliquating necrosis. Occlusion of the renal artery by embolization or ligature leads only to partial necrotization or atrophy. Total devascularization of the renal hilus or total devascularization of a specific renal segment by strangulating sutures leads to total destruction of the devascularized (devitalized) tissues. Within 8-12 weeks, the whole organ changes into a small residue of connective tissue. The possibility of the use of the devascularization technique in the treatment of tumours is discussed.

The first successful trial to stitch a perforated gastric ulcer was carried out by Ludwig Heusner in the year 1892 (cit. Lau and Leow, 1997;Martin, 1992). Gradually a number of authors increased the use of the ulcer stitching in one or more layers, some of them excised the ulcer and sutured the incurred defect. If narrowing-down took place, the situation was solved by means of pyloroplastic surgery or by formation of enteroanastomosis. Where the ulcer is closed with stitches some authors applied the tamponade with a tip of omentum major. The omentum inserted in the perforation opening was secured in this position by stitching through. Later on the stomachic resections approached the mentioned procedures, however, the implementation of such an intervention requires the early determination of perforation. In desperate situations when the ulcer could not be closed by either stitching or by resection of stomach, the gastrostomy was carried out at a point of perforation. In extraordinary situations we may consider the closing of perforation with stitching the gallbladder fundus in the perforation opening (cholecystogastrostomy) or the stitching of perforated stomach into the abdominal wall. The latter intervention, i.e. the stitching of perforation into the abdominal wall, was been described in an earlier book by Jirásek (1958). He attributed this method to Braun, however, Braun has not been included in the list of references. We searched for this type of operation in the literature available, however, with the exception of the mentioned incomplete reference nobody was dealing with this unusual intervention. We therefore decided to elucidate the problems in an experimental way.The experiments were carried out on 6 laboratory miniature pigs at the weight of 1530 kg and 10 rats of the Wistar strain at the weight of 270320 g. The technique of operation was uniform. In a complete anaesthesia we opened the peritoneal cavity on the middle line in the epigastrium. We established the model perforation on the gastric body in the region above the angle of stomach. Among four supporting stitches we excised the fore wall so obtaining an opening with a diameter 57 cm for pigs and 1.5 cm for rats. We seamed the opening around the whole periphery with single stitches. Then we stitched by degrees the fore stomach wall with a perforation point to the parietal peritoneum with single stitches. In the stomach we took the seromuscular layer, on the abdominal wall the serous membrane and the subserous fibres. Thus, we attached knotting stitches to the stomach wall over the periphery of perforation to the abdominal wall, namely the left part of the operation wound. The abdominal cavity was gradually closed in layers. For 23 days following the operation the animals were administered liquid food. We observed the animals clinically and by histology. After 8 weeks we excised from laparotomy a part of abdominal wall with the original perforation opening (biopsy in pigs). As for rats, we killed them and took the same part of stomach for the post...