[Angiocardiography with axial projections in the study of various types of intraventricular septal defects]

The exact site of an interventricular septal defect (VSD) is important mainly to program surgical treatment. The present study takes into consideration the possibility of the axial angiocardiographic method to identify the site of the interventricular septal defect. With this goal 126 cases of VSD in infancy were retrospectively studied with left ventriculograms using angled "long-axial" and "four chambers" views. In 62 cases the anatomic-angiographic correlation of the VSD site was reached, and was confirmed at surgery. The most frequent localization of the VSD was perimembranous (89 cases, 70%). The rarest localizations were the sub-arterial and the multiple VSD. The personal experience agrees with the data found in literature, namely that angiocardiography performed with axial views has an elevated diagnostic reliability in the various types of VSD.

Insulin effects on human red blood cells

The effect of insulin on human red blood cells was investigated, both on intact cells and on isolated plasma membranes, testing the responsiveness of membrane-bound enzymes--such as (Na+-K+)-ATPase and 5'-nucleotidase--as well as the ouabain binding and ionic fluxes. It appears that insulin stimulates Na-pumping mechanisms increasing (Na+-K+)-ATPase activity through an enhanced availability of pumping sites, as can be inferred from the increased ouabain binding. The apparent unresponsiveness of fluorescence polarization parameters, following insulin treatment of isolated plasma membranes and intact cells, rules out--at present--an involvement of membrane lipid fluidity in the mechanism of action of insulin on human erythrocytes.

PGE restores the immune response in chemotherapy-treated, tumor-bearing mice

Two hundred seventy-one B-16 melanoma-bearing mice were randomized and treated for 4 days with either control diluent, 10 micrograms of 16,16-dimethyl-PGE2-methyl-ester (di-M-PGE2), chemotherapy, or chemotherapy plus di-M-PGE2. The chemotherapeutic regimens included adriamycin (7.5 mg/kg), 5-fluorouracil (250 mg/kg), nitrogen mustard (5 mg/kg), and vincristine (0.5 mg/kg). The number of plaque-forming cells and hemagglutinin titers in response to sheep erythrocytes were used as measures of humoral immunity while cellular immunity was assessed by evaluation of delayed hypersensitivity. As we previously reported, the presence of subcutaneous B-16 tumors induced substantial immunosuppression and this suppression was reversed by treatment with di-M-PGE2. Treatment with all four chemotherapeutic agents induced profound immunosuppression. Similarly, the addition of di-M-PGE2 to the chemotherapy protocols resulted in significant augmentation of cellular and humoral immunity.

Impairment of in vitro generation of cytotoxic or T suppressor lymphocytes by Friend leukemia virus infection in mice

Spleen cells collected from DBA/2 (H-2d) mice inoculated with the polycythemic variant of Friend-Leukemia Virus Complex (FLV-P) were tested for T-dependent immune functions, such as the in vitro generation of cytotoxic T lymphocytes (CTL) and of non-specific T suppressor lymphocytes (STL). CTL were generated against H-2b splenocytes, and STL were obtained following a 5-day lymphocyte culture without stimulator cells. A progressive and severe impairment of the generation of both CLT and STL was found from 2 weeks onward after infection, being almost totally abolished 3-4 weeks after virus challenge. Suppressor cells (SC) capable of inhibiting CTL generation was detected in FLV-P bearing mice. Suppressor activity was unaffected by anti-Thy 1.2 serum and complement but was removed following iron-magnet depletion or passage through nylon-wool column. Moreover complete recovery of the competence of CTL generation was attained when FLV-P infected splenocytes were passed through nylon-wool column. It is concluded that FLV-P infection depresses T-dependent cytotoxic and suppressor responses in mice, by the appearance of non-T adherent phagocytic cells, capable of impairing CTL generation in vitro.

[The immunity of senescence. Study of lymphocytes in vitro. I: Rosette forming lymphocytes]

E and EAC rosettes forming lymphocytes were evaluated in 25 elderly subjects (mean age 84.76 years) without manifestations of neoplastic or infectious diseases. The percentage of E rosettes appeared within the normal range in about 50 per cent of cases and below normal in remaining 50 per cent. No evident sex-related differences were observed. The percentage of EAC rosettes showed a larger distribution of values. In fact, 56 per cent of cases fell within normal limits, 26 per cent was higher and 20 per cent lower than normal. Our results are in agreement with the data reported in the most recent literature, which indicates that the main target of immune system senescence is the T-cell population, while B cells do not show significant age-related variations. The significant number of cases with percentages of EAC rosettes higher than normal may be attributed to the failure of immune homeostatic mechanisms normally exerted by T cell subpopulations. Further studies on several immune system functions in advanced age are in progress.

[Characterization of the convoluted seminiferous tubule wall. II. Ultrastructural alteration after testis retention in the abdominal cavity]

An ultrastructural analysis has been carried out on the seminiferous tubules after different periods of stay of the rat testis in the abdominal cavity. With respect to control rats, no changes are detectable after 5 days, while after 15 and 30 days considerable modifications take place. A number of cellular features are modified, such as the nuclear shape and the perinuclear vesicles, while the cytoplasmic filaments show a less ordered appearance. In addition, the extracellular amorphous matrix undergoes a large increase, due either to an enhanced production or to a reduced turnover related with a lowered cell activity.

[Characterization of the convoluted seminiferous tubule wall. I. Ultrastructural aspects after the ligation of the vas deferens and the efferent tubules]

The structure of the wall of the rat seminiferous tubules has been studied by electron microscopy. No significant modifications have been revealed after the ligature of the vas deferens while on the contrary the ligature of the efferent ductules produces a reduction of the contractile filaments and of the pinocytosis vesicles, as well as an increase of the amount of collagen fibers in the basal membrane.

[Effects of PGA 1 on immune response in mice with melanoma B 16]

This study evaluated the effects of PGA1 on B 16 melanoma bearing mice. PGA1 was observed to inhibit the rate of melanoma growth, both as delay in the rate of appearance and decrease in tumor volume. Furthermore PGA1 stimulated humoral but not cellular immune response in melanoma bearing mice, while it was ineffective in normal mice.

[Preliminary study on the effects induced by an anemic strain of Friend leukemia virus in DBA/2 mice]

Serum thymic factor (STF) and azathioprine (AZ) inhibition test were assayed in sera and spleen cells from DBA/2 and BALB/c mice, inoculated with the anemic strain of Friend leukemia virus. The observed decrease of STF levels appears to be related to the LLV (Lymphatic Leukemia Virus) component of FLV-A.