Smooth muscle cells growing in the primary culture derived from outgrowths of the intimal-medial explants of both rat and human arteries were used. The 72-hr sequential glucose uptake by the cells of both species in culture dishes was enhanced only slightly with time by the addition of insulin to culture medium, and this enhancement was statistically not significant. The glucose conversions to CO2 and lipids by the rat and human cells dissociated for tracer study were not affected significantly during the 2-hr incubation by the insulin addition in vitro. The smooth muscle cells of both species cultured for a week in medium enriched with insulin and then dissociated revealed the significantly increased glucose conversion to lipids, while the increase in the glucose conversion to CO2 was not significant in these cells. Thus, the smooth muscle cells of both rat and human seem to show significant metabolic response to chronic, but not acute, exposure to insulin. Therefore, it is likely that the persistent change in the insulin level may lead to abnormal metabolic state in the artery.
A patient with steroid hormones or androgen producing bronchogenic adenocarcinoma was presented. Clinically he had a mediastinal mass and bilateral multiple pulmonary nodules which showed a rapid growth despite cancer chemotherapy. At postmortem examination, radioimmunoassay of the tumor tissue revealed androgen and their precursors. The mitochondria of the tumor cells resembled those of cells in the zona reticularis of the adrenal cortex.
A screening method for new antimicrobial agents from streptomyces culture filtrates was developed. Three different types of test organisms were used for determining the antimicrobial activities of the culture filtrates: they were (a) an antibacterial activity test against Staphylococcus aureus, (b) an antimycoplasmal activity test against Acholeplasma laidlawii, and (c) a cytotoxicity test against HeLa-S3 cells. The active filtrates showing antimicrobial spectra (anticellogram) which did not match those of known antimicrobial agents were used for further purification to obtain new antimicrobial agents. Of these screening methods, antimycoplasmal activity against Acholeplasma laidlawii was the most sensitive for discriminating new compounds contained in the filtrates of known antibiotics.
A new separation method of two populations of liposomes and the use of the method in an assay of phospholipid exchange activities are described. The major constituents of these liposomes were rat liver total phospholipids and cholesterol in molar ratio of 2:1. One population of the liposomes was made reactive to concanavalin A by the incorporation of either 1.8 mole% α-D-mannosyl-(1→3)-α-D-mannosyl-sn-1, 2-diglyceride from Micrococcus lysodeikticus or 0.77 mole% α-D-mannosyl-(1→4)-β-D-mannosyl-(1→4)-D-glucosyl-ceramide from Corbicula japonica. The other population of the liposomes was concanavalin A-nonreactive. The two liposomal populations were separated by addition of concanavalin A to agglutinate the reactive liposomes. In the assay of phospholipid exchange activities, these two populations of the liposomes were incubated with either the cytosol protein of rat liver or partially purified phospholipid exchange proteins from rat liver in a total volume of 0.2 ml. Either the concanavalin A-reactive liposomes or the nonreactive liposomes were used as a phospholipid donor. The phospholipid donor was doubly labeled with [3H]lactosyl ceramide and that class of [32P] phospholipids whose exchange was being measured. The [3H]glycolipid served as a nonexchangeable reference marker. After the incubation, the two liposomal populations were separated. The amount of phospholipid transferred from the donor to the acceptor liposomes was calculated from the decrease of 32P to 3H ratio of the donor liposomes during the incubation.
Mastocytoma cells, a rapidly growing tumor derived from mast cells of DBA/2 mice initially injected with methylcholanthrene, were used as a source of cellular and cell-free extracts for immunizing rabbits. Antisera prepared in rabbits against intact tumor cells, grown either in vivo or in vitro, as well as against cell-free tumor extracts, ascitic fluid, and culture fluids were examined for their ability to neutralize the immunosuppressive activity of cell-free ascitic fluid from mastocytoma-bearing mice and the effects of antisera on the in vivo susceptibility of mice were also tested. The antisera prepared against tumor cells, cell-free extracts or culture fluids neutralized the immunosuppressive activity of cell-free ascitic fluid from tumor-bearing mice. On the other hand, none of the sera passively protected mice upon challenge with living tumor cells. Furthermore, some mice treated with sera from rabbits immunized with intact tumor cells succumbed more rapidly to the tumor upon challenge, but this seemed due to a serum sickness-like reaction. Direct immunization of mice with either cell-free extracts or culture fluids did not protect the animals from direct challenge with mastocytoma cells. Thus, the presence of similar antigens in intact tumor cells, cell-free extracts and culture fluids, which stimulated antibodies readily detected by in vitro serologic assays, did not necessarily result in antibody activity which directly or indirectly protected mice in vivo.
Aconitine (AC), mesaconitine (MA), hypaconitine (HA) (50 μg/kg i.v.), benzoylaconine (BA), benzoylmesaconine (BM) and benzoylhypaconine (BH) (5 mg/kg i.v.) produced a weak temporary hypotension in rats which was blocked to some extent by atropine. In the isolated guinea pig right atria, MA and HA (3×10-8 g/ml) mediated a positive inotropic action and a positive chronotropic action. At the higher concentration of 10-7 g/ml, AC, MA and HA exhibited the above actions followed by inhibition of contractions and disorder of the beating rate. In the isolated guinea pig ileum, AC, MA and HA (>10-6 g/ml) caused a contraction which was completely blocked by atropine. In the isolated guinea pig vas deferens, AC, MA and HA (>10-5 g/ml) elicited a contraction which was completely obliterated by phentolamine. In the isolated guinea pig hypogastric nerve-vas deferens, the isolated rabbit mesenteric nerve-jejunum and the isolated rat phrenic nerve-diaphragm, responses induced by the electrical stimulation of the corresponding nerves were inhibited by AC, MA and HA (10-6-10-5 g/ml). Some of the mechanisms of the above actions induced by these alkaloids are discussed. These alkaloids more or less potentiated the hexobarbital anesthesia, inhibited the revolution of the wheel cage, and reduced the rectal temperature in mice, indicating that they have a depressant activity on the central nervous system.
Disintegration of urinary calculi was attempted by the use of laser beam. As a first step, drilling of extracted urinary stones was attempted using a continuous wave CO2 laser and a pulse ruby laser. Stones were drilled easily by either laser beam. The power around 10 W of continuous CO2 laser beam was sufficient to drill through the stone.
To reveal the recurrent inhibitory circuit in the visual cortex, a depolarizing current was applied through a glass microelectrode to an impaled cell in an in vitro slice of the visual cortex obtained from a cat anesthetized with pentobarbital. The cell reported here produced inhibitory postsynaptic potentials (IPSPs) following single spikes or bursts of spikes which were elicited by intracellularly applied current. This observation indicates that IPSPs have been mediated by the recurrent inhibitory circuit via axon collaterals of the impaled cell.
The effect of Ca-antagonist on the contractile apparatus was investigated in glycerinated cardiac papillary muscle preparations obtained from canine hearts. The results showed that maximal developed tension (P0) was enhanced significantly by 5 mg/liter of verapamil, and the augmentation of contractility was dependent on the concentrations of verapamil. As a conclusion, Ca-antagonist appeared to be a potentiating agent of the contractile force on the contractile apparatus.