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Data obtained in our experiments indicate that the microwave sterilization system utilized may be considered as a practical and rapid method for decontaminating steel surgical instruments. For the tested organisms (7 Gram- and 2 Gram+ genera) a 3' exposure time to microwaves provides successful sterilization. Microwave irradiation also had a killing action against Bacillus subtilis spores. A study by SEM of microwave treated spores shows typical morphological alterations of spore surfaces.

Microwave exposure (90 s) provides an effective, rapid sterilization for surgical scalpel blades which have been contaminated with Candida albicans. SEM analysis showed that microwave irradiation induced a morphological modification of the cells. The longer the exposure time the greater such alterations and this micro-organism in effect fractures after 9 min. No evidence was found of morphological alteration of the fungus after being submerged in boiling water for the same amount of time even though cell death was actually achieved.

Microwave irradiation provides a rapid and effective method for sterilization of stainless steel scalpel blades or cover glasses contaminated by B. stearothermophilus. A study by SEM of vegetative forms showed that microwave irradiation induce a progressive series of alterations and finally the complete destruction of the microorganism. On the contrary there were no significant morphological variations of the spores after lethal irradiation by microwaves.

A new method is described which makes it possible to treat metal materials with microwaves. In consequence scalpel blades as well as cover glasses contaminated with four species of bacteria (Salmonella typhi, Proteus mirabilis, Escherichia coli and Pseudomonas aeruginosa) were sterilized. With this method sterilization can be achieved quite rapidly (1.5-2 min). Scanning electron microscopy revealed a progressive alteration in the morphology of micro-organisms and this proved proportional to the microwave exposure time. Only in Proteus mirabilis were no modifications found, even after long periods of microwave exposure.

The morphology of differentiated and differentiating cells of the red and white series in Lutjanus herenbergi and in Lutjanus flaviflammus is described. Early stages of red and white blood cells may be found only in smears of hemopoietic organs. Polychromatic erythroblasts, myelocytes and lymphoblasts may also occasionally be found in blood smears. Mature blood cells may be found both in blood smears and in hemopoietic organs. Differential white cell counts seem to demonstrate that the granulocytic series elements are the most common leukocytes in blood smears. Almost all granulocytes may be classified in the first three Arneth classes. An analysis of hemopoietic organs in these species was also performed. It was found that the only organs carrying on a hemopoietic function are the kidney and the spleen. The kidney is essentially a site of granulocytic differentiation while the spleen is a lymphopoietic organ. An erythropoietic activity may generally be observed in the kidney although weak erythropoietic activity may at times be found in the spleen.

Vitamin A can transform, in vitro, keratinized, multilayered, non secretory epithelium of carcinoma of portio cervicis into a simple mucous-secreting epithelium in the 40% of explants. The different response of Vit. A action on carcinoma may be associated with a different sensibility to this substance.

A case of acute myelomonocytic leukemia terminating in histiocytic medullary reticulosis is reported. The evolution of a single cellular clone presenting with progressive change of the morphological features of the leukemic cells towards more anaplastic elements endowed with prominent phagocytic properties is suggested on the basis of both cytochemical and chromosomal data. The histiocytic nature of the malignant proliferating cells and platelet phagocytosis has been confirmed by electron microscopic investigation. The main pathogenetic explanations of the evolutionary patterns of the disease are discussed with relation to: a) involvement of a common stem cell giving rise to different proliferative patterns of cells in a multiphasic sequence; b) release of dysplastic platelets and defective erythrocytes with massive sequestration by histioid phagocytic cells; and c) coexistence of two different disorders.

Chromosomal studies have been performed in 2 patients with angio-immunoblastic lymphadenopathy. In both the cases the presence of abnormal cell lines characterized by marker chromosomes has been detected. Application of banding techniques allowed to detect the structural composition of the marker chromosome in 1 of the cases and to show a clonal evolutive pattern of the rearranged chromosomal set; In the same patient a consistent Y loss observed in the major fraction of the investigated metaphases did not appear to be related to any defined rearrangement of the karyotype. Longitudinal chromosomal studies are stressed in order to better correlate th cytogenetic abnormalities and the immunoreactive picture of the lymph nodes along the course of the disease.

Tetra benzamidine derivatives were found to inhibit proteinase activity, cell proliferation and accumulation of the Ha-ras-1 mRNA in the FHO6T1-1 Chinese Hamster cell line, transformed with the activated human T24-Ha-ras-1 oncogene. Di- and Tri-benzamidine derivatives were also found to be potent inhibitors of proliferation of FHO6T1-1 cells. These latter compounds could be proposed as useful substrates in the synthesis of drug-conjugated monoclonal antibodies or growth factors.