Immunoglobulin as the major low density lipoprotein binding protein in plasma.

Plasma from normal humans and Chinese hamsters was shown to contain material which binds to low density lipoproteins (LDL). The binding capacity of these plasmas was demonstrated by passive hemagglutination against human LDL-coated red blood cells. The plasmas were fractionated by affinity chromatography, gel filtration and electrophoresis. Immunologic analyses of these fractions showed that IgM and IgA were the major plasma proteins responsible for the LDL binding titers of human and hamster plasmas. The titer of binding protein in diabetic and non-diabetic humans and hamsters was also determined.

Microbiota Associated with the Gastrointestinal Tract of the Common House Cricket, Acheta domestica.

The location and morphology of the bacteria associated with the gastrointestinal tract of Acheta domestica were studied, and these bacteria were partially characterized. Bacteria were associated with the peritrophic membrane in the midgut and with the gut wall and cuticular structures of the hindgut. No bacteria were associated with the fat bodies. Colony-forming unit determinations indicated that there were three times more cultivatable bacteria in the hindgut than in the midgut. Of these bacteria, 40 to 85% cleared uric acid anaerobically, and 90 to 100% cleared uric acid aerobically. Of the 25 isolates obtained, 21 belonged to the genera Citrobacter, Klebsiella, Yersinia, Bacteroides, and Fusobacterium.

Electron microscope study of 1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid, an exfoliative antispermatogenic agent, in the rat testis.

We were interested in discovering whether the antifertility agent, DICA [1-(2,4-dichlorobenzyl)-1-H-indazole-3-carboxylic acid] induced Sertoli cell tight junction damage. Testis were fixed in 1% lanthanum nitrite cacodylate-buffered 2% gluteraldehyde at various times following a single oral 100 mg/kg dose of DICA. In control animals adluminal lanthanum was never seen. At one and ten days following DICA treatment adluminal lanthanum was seen. This suggests that the Sertoli cell tight junctions are more permeable to lanthanum following DICA treatment.

Fertilization of rabbit ova in vitro by sperm with adsorbed Sendai virus.

Fertilization occurs when rabbit ova are cultured in vitro with epididymal sperm to which Sendai virus is adsorbed. These sperm do not require capacitation in vivo in order to fertilize. Evidence for fertilization is penetration of sperm, the appearance of two polar bodies and pronuclei, and cleavage through the eight-blastomere stage. The viruses attach almost exclusively to the sperm acrosome, with resultant head-to-head agglutination of the sperm.

Centrifugal sedimentation of virus particles for electron microscopic counting.

Centrifuge cells with conical chambers were provided by using special inserts for the stainless-steel tubes that fit the Spinco SW-39 rotor. Particulate material, centrifuged in these cells, was collected on carbon-coated glass discs. These discs were exposed to OsO(4) vapor, dehydrated in graded alcohols, air-dried, and metal-shadowed. The metal-shadowed carbon film was floated from the glass, mounted on a grid, and examined. A knowledge of cell geometry and microscope magnification allowed correlation of the number of particles observed to a volume of the original suspension. A precision of +/-6% at the 95% confidence level was attained when counting approximately 100 particles per 10,000 x field. Applications and advantages of the method are discussed.