Mario Montes

Effect of varying freezing and thawing rates in experimental cryosurgery

Six different freezing/thawing programs, which varied freezing rate, duration of freezing, and thawing rates, were used to investigate the effect of these factors on cell destruction in dog skin. The range of tissue temperatures produced was from -15 to -50 degrees C. The extent of destruction was evaluated by skin biopsies 3 days after cold injury. In single, short freezing/thawing cycles, the temperature reached in the tissue was the prime factor in cell death. Longer freezing time and slow thawing were also important lethal factors which increased destruction of cells. Cooling rate, whether slow or fast, made little difference in the outcome. The experiments suggested that present-day, commonly employed cryosurgical techniques, which feature fast cooling, slow thawing, and repetition of the freeze/thaw cycle, should be modified by the use of maintenance of the tissue in the frozen state for several minutes and slow thawing. Thawing should be complete before freezing is repeated. These modifications in technique will maximize tissue destruction, an important consideration in cancer cryosurgery.

Evolution of membranous nephropathy into anti-glomerular-basement-membrane glomerulonephritis.

Abstract In a patient with biopsy-proved membranous nephropathy (nephrotic syndrome) acute fatal renal failure suddenly developed. Autopsy revealed rapidly progressive glomerulonephritis superimposed on the previous membranous changes. IgG eluted from the kidney was shown by immunofluorescence technic to bind to the glomerular basement membrane of normal human and monkey kidneys, and was capable of producing an acute anti-glomerular-basement-membrane nephritis in two monkeys. The IgG antibody, by radioisotopic methods, was specifically directed against primate kidney. It is postulated that immune complexes responsible for the original membranous nephropathy induced release of antigenic glomerular-basement-membrane fragments into the circulation, stimulating formation of antibodies to the membrane and producing fatal acute glomerulonephritis. (N Engl J Med 290:1340–1344, 1974)

Ultrastructure of cerebellar hemangioblastoma.

Light and ultrastructural features of a cerebellar hemangioblastoma in a 56‐year‐old man are described in detail. The neoplasm was composed of three major cell types: endothelial cells, pericytes, and stromal cells. The endothelial cells lined the fenestrated vascular channels. The pericytes were ensheathed by their own basal lamina which separated them from the basal lamina covering the endothelium. The stromal cells contained, in addition to the conventional organelles, numerous membrane‐bound lipid inclusions, annulate lamellae, and nuclear bodies. There were also present transitional cells which shared the fine structure of all the three major cell types. Histogenetically, the tumor was considered to be of vascular origin. The stromal cells represented the stem cells which, under the neoplastic influence, continued to proliferate and differentiate into “vasoformative”elements (pericytes and endothelium) which formed new blood vessels. The transitional forms between the stromal cells and the “vasoformative”elements suggested that the cellular components of a hemangioblastoma shared a common ancestry, most likely of an angioblastic lineage. Cancer 42:1834‐1850, 1978.

Critical temperature for skin necrosis in experimental cryosurgery

Abstract To investigate the minimal lethal freezing temperature required to produce skin necrosis in dogs, multiple skin sites were frozen with cryosurgical equipment. Tissue temperatures were recorded from thermocouple sites placed at diverse distances, usually 5 mm from the edge of the freezing probe. In single freezing cycles of about 3 min duration, tissue temperatures in the range of 0 to −60 °C were produced. Punch biopsies of the skin at the thermocouple sites 3 days after freezing injury provided tissues for estimation of viability by histologic examination. The histologic findings permitted classification of the biopsy tissue into three groups, that is, viable, borderline, or necrotic. When classified as borderline, the division between the necrotic and viable tissue was evident on the histologic slide. The viable specimens were scattered through the 0 to −35 °C range. All specimens frozen to −10 °C or warmer were viable. In biopsies classified as borderline, the range of viability extended from −11 ° to −50 °C. The necrotic biopsies covered a range of −14 ° to −50 °C. Cell death was certain at temperatures colder than −50 °C. The data showed cryosurgical freezing conditions produced a range of temperatures in which viability or death of tissue may occur and that the ranges of viability and necrosis overlapped to a great extent. The wide range of temperatures at which cells were viable shows the need to achieve tissue temperatures in the range of −50 °C in the cryosurgical treatment of cancer.

D-Galactosamine Liver Injury: Absorption of Endotoxin and Protective Effect of Small Bowel and Colon Resection in Rabbits

Abstract D-Galactosamine is an amino sugar with unique hepatotoxic properties in animals. Although the mechanism of liver injury by galactosamine remains controversial, a role for bacterial endotoxin has been suggested. In the present study, using New Zealand rabbits, we show that the significant increase in serum glutamic oxaloacetic transaminase which followed the injection of 4.25 mmole/kg of D-galactosamine was completely prevented in animals subjected to resection of small bowel and colon. Using an immunoradiometric assay specific for E. coli 026 endotoxin we showed that after instillation of 50 mg of E. coli into the colon, serum levels of this endotoxin were higher in the animals injected with galactosamine than the controls injected with saline. However, the differences in endotoxin concentration between the two groups of animals was statistically significant only at 30 and 60 min. The role of endotoxin in the pathogenesis of galactosamine liver injury is reviewed and discussed.

Large volume freezing in experimental hepatic cryosurgery. Avoidance of bleeding in hepatic freezing by an improvement in the technique.

Abstract In experiments on the dogs liver, large volumes of tissue were frozen by pouring liquid nitrogen onto the liver surface. There were no complications and no death from the procedure. Safety was produced by covering the liver surface with one to three layers of dacron velour cloth impregnated with a water-soluble jelly. The protective action of the gel-cloth was due to splinting of the liver capsule and to a more uniform and slower rate of freezing. The tissue became necrotic and over several months was replaced by dense fibrous tissue and ultimately resorbed. Although bleeding has been prevented, the problem of limitation of depth penetration remains as a hindrance to utilization in the treatment of hepatic tumors.

Recurrence of Henoch-Schönlein purpura glomerulonephritis in transplanted kidneys.

An 8-year-old boy developed a skin rash, gastrointestinal symptoms, and acute glomerulonephritis with immunopathological findings characteristic of Henoch-Schönlein purpura. After renal transplantation the skin rash, gastrointestinal symptoms, and glomerulonephritis recurred. The similarity between the immunopathological changes found in the hosts kidneys and those observed in the graft are consistent with the interpretation of a transmission of Henoch-Schönlein purpura to the renal transplant.

Experimental hepatic cryosurgery

Abstract In 28 dogs, a major portion of a lobe of the liver was frozen, either by contact with a cryoprobe or by spraying liquid nitrogen (−196 °C) over the exposed liver or by pouring liquid nitrogen into a plastic barrel placed on the lobe of the liver, which was wrapped in a Dacron velour cloth. With the probe technique, the amount of tissue that could he frozen was not as great as with direct application of liquid nitrogen to the liver. The spray technique allowed freezing of a larger area but with cracking of the liver substance with considerable mortality from bleeding. With the pour technique, even a larger area of liver could be frozen and bleeding was much less because of the protection afforded by the Dacron cloth. There were no toxic effects from the devitalized liver which was left to be resorbed. These techniques are applicable for treating localized lesions in the liver in humans, but the experiments demonstrate the difficulty of achieving great depth of freezing with any currently available technique of freezing tissue in situ . Clearly, advances in cryosurgical equipment are needed.

Destruction of hepatic and splenic tissue by freezing and heating

Abstract Penetrating wounds of the spleen and liver were treated by either freezing or heating, or both, using special instrumentation which could be cooled to − 190 °C or heated to 200 °C. The hemostatic and destructive effects were evaluated. Freezing produced maximal destruction while heating produced maximal hemostasis. Combined freezing/heating techniques produce maximal destruction while maintaining hemostatic control. The results of these experiments suggest that further investigation of the combined technique is warranted with the view toward application to the treatment of visceral tumors.

Eosinophilic cystitis: A therapeutic challenge

Eosinophilic cystitis is a rare disease with only 42 cases reported since first described in 1960. We report a case in a twenty-four-year-old woman and present the different therapeutic alternatives. A review of all reported cases shows that except for children and male adults with benign prostatic hypertrophy, this is a chronic inflammatory process of unknown causation for which no specific therapy is available.