Ultrastructure of L forms. IV. L forms of nonagglutinating vibrios]

A study was made of the ultrastructure of stable L-forms of Nag vibrios aged 24 hours. Cells of all types of the L-forms had cytoplasmic membranes, and a three-layered structure, which was found not everywhere. Externally of the cytoplasmic membrane, in some areas of the individual cells there were revealed a plastic layer of cell wall and a basal membrane. However, in difference to bacterial forms of the vibryos, rigidity of the cell wall was disturbed, and the links between the cell wall and the cytoplasmic membrane were indetectable. There were regularly revealed lamellar of myelin-like membranous structures in the cytoplasm, which did not occur in bacterial forms, and also lamellar mesosomes. The latter were found in the sites of cell division. Viability of small bodies as the minimal reproductive forms of the L-cultures is confirmed by the presence in them of a nucleoid and of the binary division.     

Immunity to exoerythrocytic forms of malaria. II. Passive transfer of immunity to exoerythrocytic forms

The passive transfer of heat-inactivated or nonheat-inactivated convalescent serum, from turkeys inoculated with Plasmodium fallax exoerythrocytic forms and treated with chloroquine to suppress the development of erythrocytic forms and the development of immunity to them, delayed the exoerythrocytic-form infection in turkeys inoculated intravenously with exoerythrocytic forms. The degree of exoerythrocyticform parasitization in cerebral tissue was significantly less in the experimental groups than the degree of parasitization in control groups, and the experimental birds continued gaining weight for a longer period than the control birds. The passive transfer of immune serum had an effect on the course of the exoerythrocytic-form infection equivalent to killing 90% of the exoerythrocytic-form inoculum. The immunity to exoerythrocytic forms is form-specific, since the infected, chloroquine-treated, serum donors were just as susceptible to an erythrocytic-form challenge infection as normal turkeys.In vitro studies demonstrated that heat-inactivated serum from turkeys immune to exoerythrocytic-form infections caused a precipitate to form at the small end of exoerythrocytic merozoites. This precipitate was not observed on merozoites mixed with control serum.     

Spectroscopic forms of carbonmonoxi-cytochrome oxidase.

A systematic study of the errors of low-temperature recording of kinetics of the cytochrome oxidase-CO reaction had identified the classic devitrification process of Keilin & Hartree [(1950) Nature (London)165, 504-505]. The methodology described here minimizes this effect, and the computation methods afford appropriate ways of detecting a residual effect. Thus it has been possible to identify that absorption difference spectra and kinetics of the reaction of fully reduced or half-reduced cytochrome oxidase with CO indicate only one spectroscopic form of the respective carbonmonoxi-cytochrome oxidase.     

Multiple molecular forms of phosphoprotein phosphatase. Separation of four forms of the rabbit skeletal muscle enzyme.

Phosphoprotein phosphatase [phosphoprotein phosphohydrolase EC 3.1.3.16] in the soluble fraction of rabbit skeletal muscle, when assayed with phosphorylase a[EC 2.4.1.1] from rabbit skeletal muscle and phosphohistone as substrates, was resolved into three active fractions (Fractions I, II, and III in order of elution) by DEAE-cellulose column chromatography. Sucrose density gradient centrifugation showed that these fractions were composed of subfractions of different molecular size (I: 7.3S and 4S; II: 8S and 4S; III; 6.7S). Components with larger molecular size in the major fractions, II and III, were dissociated to a molecular size similar to that of the smallest component on freezing in the presence of mercaptoethanol. These results indicate that phosphoprotein phosphatase from skeletal muscle occurs in multiple forms very similar to those of the liver enzyme reported previously (Kobayashi, Kato and Sato (1975) Biochim. Biophys. Acta. 373, 343-355).     

Two crystal forms of Azotobacter ferredoxin.

Two crystal forms of Azotobacter vinelandii (4Fe-4s)2 ferredoxin I (Fd I) have been grown which are suitable for high resolution x-ray diffraction studies. Tetragonal crystals grow as square bipyramids from ammonium sulfate and Tris buffer using a temperature gradient. The space group is P41212 (or P43212) with a = 55.3, c = 95.9 A and 1 molecule/asymmetric unit. Triclinic crystals grow as plates or laths from ammonium sulfate and phosphate buffer at constant temperature. The space group is P1 with a = 46.8, b = 58.7, c = 64.3 A, alpha = = 105 degrees 05 min, beta = 82 degrees 30 min, gamma = 110 degrees 30 min and 4 or 5 molecules/unit cell. Both crystal forms are stable to x-ray irradiation and diffract beyond 3.0 A resolution.     

Special forms of initial gastric cancer.

1. Fifty-five microscopic cancer foci from 11 gastric resection preparations have been examined. Each focus than 5 mm was less in diameter. They occurred mostly in regions showing chronic atrophic gastritis, less frequently in the margin of peptic ulcer or in a polyp located in the antrum along the lesser curve. The lesions were discovered at routine histologic examination of stomachs operated upon for other primary diseases. 2. Histologically differentiated and undifferentiated types could be distinguished. They were: well differentiated adenocarcinoma, tubular adenocarcinoma, "intraluminal papillary proliferation of the glandular neck", "glandular neck displasia" mucocellular and muconodular carcinoma, and carcinoma in situ. In some cases, different histologic types within the same focus, or more foci of diverse structure in the same patient could be observed. 3. A malignant process developing from the glandular neck region or the surface epithelium could be demonstrated in each type of initial cancer.     

Multiple forms of human phosphoglycerate kinase.

Phosphoglycerate kinase was isolated by affinity chromatography from human skeletal muscle and erythrocytes. As in the tissue extracts, the purified enzyme showed in Cellogel electrophoresis one major and two minor bands with phosphoglycerate kinase activity. The multiple forms were separated by chromatography on CM-Sepharose. From the three separated forms, A, B, and C, the latter was not detectable in electrophoresis of tissue extracts or in the purified unresolved phosphoglycerate kinase. The faintest, most anodically migrating form observed in the tissue extracts could not be isolated in pure form by chromatography on CM-Sepharose. The electrophoretic mobility of the phosphoglycerate kinase forms depended strongly on the buffer systems used. The different forms had identical molecular weight, substrate affinity, and heat stability and were inhibited to the same extent by antibody. They could also not be separated by column affinity chromatography. Small differences were found in thiol group content and in the specific activity, the latter being a consequence of diminished free sulfhydryl residues. Exposure to either reductive or oxidative conditions changed the specific activity, but did not result in interconversion among the pure forms. The multiple forms probably arise as a result of epigenetic factors occurring after the primary polypeptide chain has been synthesized.