The eye muscles and their innervation in the gobiid fishTridentiger trigonocephalus

The morphology and innervation of the six oculomotor muscles in the gobiid fishTridentiger trigonocephalus are described. Every rectus muscle is composed of two types of muscle fibres. Muscles attach onto the cartilaginous or fibrous sclerotica. Oblique muscles attach onto the ethmoidal plate; recti muscles attach onto the parasphenoid or a thick fibrous membrane. There is no myodome. The common oculomotor nerve is composed of four bundles, the trochlear and the externus of two. The two kinds of fibres of the lateral rectus and the two distinct bundles of the nerve VI suggest a possible homology between this muscle in fishes and the lateral rectus+retractor bulbi in mammals.     

Semen Characteristics of Purebred and Crossbred Male Rabbits

The aim of this investigation was to evaluate the semen quality traits of purebred male rabbits and their crosses under subtropical Egyptian conditions. A full 3 x 3 diallel crossing was performed for producing the first generation progeny of New Zealand White (N), Flander (F) and Rex (R) breeds. The highest ejaculate volume (p< 0.05) and percentage of live sperms (p<0.01) with the lowest percentage of sperm cell morphological abnormalities (p<0.05) had been recorded in the NF bucks. Moreover, they possessed positive estimates of direct heterosis for ejaculate volume, mass motility (Mm), individual motility (Im) and sperm cell concentration (SCC). On the contrary, pH had negative estimates of direct heterosis in all crosses and their reciprocal. Semen pH was negatively correlated with SCC (r = -0.18), Mm (r = -0.13) and Im (r = -0.23). In conclusion, the superiority of crossbreeding was particularly obvious in the New Zealand White x Flander males, which cumulated heterosis and favorable maternal effects of the Flander dams.     

Characterization and partial purification of <Emphasis Type="Italic">Candida albicans</Emphasis> Secretory IL-12 Inhibitory Factor

Background  

We have previously shown that supernatant from Candida albicans (CA) culture contains a Secretory Interleukin (IL)-12 Inhibitory Factor (CA-SIIF), which inhibits IL-12 production by human monocytes. However, the effect of CA-SIIF on secretion of other cytokines by monocytes is unknown, and detailed characterization of this factor has not been performed.     

Basement membrane protein and matrix metalloproteinase deregulation in engineered human oral mucosa following infection with Candida albicans.

A variety of morphological changes in the basement membrane (BM) are known to occur in inflammatory diseases. Modifications of the BM can be associated with significant changes in protein content. Candida albicans (C. albicans) is normally a commensal organism and is a member of the natural flora of a large number of healthy individuals. However, under certain conditions, C. albicans can invade host tissues, causing inflammation and tissue damage. The aim of this study was to investigate the effect of C. albicans on the expression and production of structural (laminin-5 and type IV collagen) and inflammatory [matrix metalloproteinases (MMPs) and their inhibitors] proteins by human oral epithelial cells. Using engineered normal human oral mucosa infected with 10(5) C. albicans/cm2 for different periods of time, we were able to demonstrate that this yeast promotes significant laminin-5 and type IV collagen gene activation and protein secretion. These effects were accompanied by MMP-2 and MMP-9 gene activation. Interestingly, only the levels of active MMP-9 rose. The increase in MMP levels was paralleled by a decrease in the secretion of type 2 matrix metalloproteinase tissue inhibitors (TIMP-2). Our results demonstrated that C. albicans has a significant effect on tissue structure through BM protein and MMP modulation. This might help C. albicans overcome the mechanical and biological defenses of the tissue and allow it to disseminate, causing severe infections. If C. albicans uses MMPs (mainly MMP-9) to disseminate, inhibition of this protease could be of interest in treating a variety of inflammatory disorders, including oral candidiasis.     

Semicontinuous penicillin production by two Penicillium chrysogenum strains immobilized in calcium alginate beads

Summary The growth rates of immobilized Penicillium chrysogenum strains are important in their application to semicontinuous penicillin production. Immobilized P. chrysogenum strains produced about 10–15% less biomass but about 1–2 times more penicillin than free suspended mycelia.In a chemically defined medium an industrial P. chrysogenum strain, S₁, produced about 10–12 times more penicillin than strain ATCC 12690. In a complex medium the immobilized P. chrysogenum S₁ produced about 12% penicillin more than in shaken cultures. In bubble column fermentations, penicillin production was 163% higher in the complex medium than in the chemically defined medium.     

Characterization of [3H]palmitate- and [3H]ethanolamine-labelled proteins in the multicellular parasitic trematode Schistosoma mansoni.

Biosynthetic labelling experiments with cercariae and schistosomula of the multicellular parasitic trematode Schistosoma mansoni were performed to determine whether [3H]palmitate or [3H]ethanolamine was incorporated into proteins. Parasites incorporated [3H]palmitate into numerous proteins, as judged by SDS/polyacrylamide-gel electrophoresis and fluorography. The radiolabel was resistant to extraction with chloroform, but sensitive to alkaline hydrolysis, indicating the presence of an ester bond. Further investigation of the major 22 kDa [3H]palmitate-labelled species showed that the label could be recovered in a Pronase fragment which bound detergent and had an apparent molecular mass of 1200 Da as determined by gel filtration on Sephadex LH-20. Schistosomula incubated with [3H]ethanolamine for up to 24 h incorporated this precursor into several proteins; labelled Pronase fragments recovered from the three most intensely labelled proteins were hydrophilic and had a molecular mass of approx. 200 Da. Furthermore, reductive methylation of such fragments showed that the [3H]ethanolamine bears a free amino group, indicating the lack of an amide linkage. We also evaluated the effect of phosphatidylinositol-specific phospholipase C from Staphylococcus aureus: [3H]palmitate-labelled proteins of schistosomula and surface-iodinated proteins were resistant to hydrolysis with this enzyme. In conclusion, [3H]palmitate and [3H]ethanolamine are incorporated into distinct proteins of cercariae and schistosomula which do not bear glycophospholipid anchors. The [3H]ethanolamine-labelled proteins represent a novel variety of protein modification.     

Studies on the effect of NAD(H) on nitrogenase activity in Rhodospirillum rubrum

The effect of NAD(P) and analogs of this nucleotide on nitrogenase activity in Rhodospirillum rubrum has been studied. Addition of NAD⁺ to nitrogen fixing Rsp. rubrum leads to inhibition of nitrogenase. NADP⁺ has the same effect but NADH or analogs modified in the nicotinamide portion do not cause inhibition. In contrast to ammonium ions, addition of NAD⁺ leads to inhibition of nitrogenase in cells that have been N-starved under argon. The inhibitory effect of NAD⁺ is more pronounced at lower light intensities. Addition of NAD⁺ also leads to inhibition of glutamine synthetase, a phenomenon also occurring when “switchoff” is produced by the addition of effectors such as ammonium ions or glutamine. It is also shown that NAD⁺ is taken up by Rsp. rubrum cells.     

Protoplasts from the cyanobacterium,Spirulina platensis

Protoplasts were obtained from the filamentous blue-green algaSpirulina platensis by treating the filaments with 0.05% (w/v) lysozyme in 0.03m phosphate buffer. The protoplasts regenerated cell walls and formed colonies when plated on a regeneration medium. The highest percentage of regeneration, 40% was obtained after 21 days.