Effects of amino acids and derivatives of cyclic adenosine 3′, 5′-monophosphate on the production of three exoenzymes by Staphylococcus, simulans biovar staphylolyticus

The extracellular protease, endopeptidase, and hexosaminidase produced by $\text{Staphylococcus}\text{,}\text{simulans}\text{biovar}\text{staphylolyticus}$ were neither induced nor repressed by amino acids but required a tryptic digest of casein for their production. Catabolite repression of exoenzyme production by glucose was not affected by exogenous cyclic adenosine 3′, 5′-monophosphate but was partially relieved by di- or monobutyryl derivatives of this compound.     

Derivatives of [3H]serotonin in organ cultures of hamster pineal gland

The purpose of this study was to determine the viability of the hamster pineal gland in organ culture and to test the effect of norepinephrine (NE) on [3H]serotonin derivatives. In this study, elevated levels of melatonin (7-fold, p less than .05), 5- hydroxytrytophol (5-fold, p less than .001), 5-methoxytryptophol (1.78-fold, p less than .05), and depressed levels of 5-hydroxyindoleacetic acid (3.8-fold, p less than .02) and methoxyindoleacetic acid (1.78-fold, p less than .05) were detected in the glands following the addition of NE to the medium. In a separate experiment, melatonin concentration in the media was also periodically measured by radioimmunoassay to determine the viability of the organ culture over a four-day period. The melatonin level on day 2 (2321 +/- 106 pg/gland) was significantly higher (p less than 0.01) than on day 3 (1542 +/- 86 pg/gland) or day 4 (805 +/- 39 pg/gland). The results of these experiments verify the viability of the hamster pineal organ culture and show that the gland responds to NE in vitro.     

Differential Expression of mRNA and Protein Encoding Retinal and Pineal S-Antigen During the Light/Dark Cycle

S-Antigen is a soluble cell protein unique to the retina and pineal gland. In the former, it is a well-characterized molecule that participates in light-induced signal transduction in photoreceptor cells. In the latter, the functional role is presently not known. The expression of S-antigen and its mRNA was examined in the rat retina and pineal gland throughout the diurnal cycle and with light interruption of the dark cycle. A cDNA for rat S-antigen was isolated from a pineal gland library to examine the mRNAs. A 1.7-kb mRNA for S-antigen was observed in both the pineal gland and the retina. Retinal S-antigen mRNA was expressed throughout the diurnal cycle and increased with light interruption of the dark cycle. In contrast, pineal gland S-antigen mRNA levels were detectable only during the dark and were absent preceding and during light. The phenotypic expression of immunoreactive S-antigen, identified with two S-antigen monoclonal antibodies (MAbs), MAb A9C6 and MAb C10C10, was analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel (PAGE) and isoelectric focusing (IEF) electrophoresis. Immunoblot analysis of gels after SDS-PAGE revealed a single 46-kDa protein in retina. In contrast, two bands of approximately 43 and 46 kDa were identified in the pineal gland. Immunoblots of the retinal extracts separated by IEF electrophoresis revealed five S-antigen isomers, which vary quantitatively throughout the diurnal cycle and when light interrupted the dark cycle. Immunoblots of the pineal gland samples separated by IEF electrophoresis indicated that the pineal gland possesses four pineal gland-specific forms of S-antigen in addition to the five forms present in the retina. The differences observed in the mRNA and protein analyses suggest tissue-specific structural components for S-antigen in the retina and pineal gland that are not regulated in the same manner.     

Rat pineal gland phosducin: cDNA isolation, nucleotide sequence, and chromosomal assignment in the mouse

The pineal gland contains a soluble phosphoprotein, phosducin, which is homologous to that of retinal photoreceptors. Phosducin has been shown to bind the beta, gamma subunits of the retinal G-protein transducin. Retinal phosducin has been cloned and now we report a rat pineal cDNA encoding phosducin. A 1217-nucleotide cDNA was isolated from a rat pineal library by DNA-DNA hybridization with a polymerase chain reaction-amplified cDNA of bovine retina mRNA for phosducin. Northern blot analysis demonstrates that the mRNA for phosducin is approximately 1.3 kb in both rat pineal and rat retina. The translated mRNA from rat pineal encodes a protein with 246 amino acids, compared to the 245 amino acids of bovine retina phosducin. The predicted molecular weight of rat pineal phosducin is 28,201. Immunoblot analysis with affinity-purified antibodies against bovine retina phosducin identify a single immunoreactive protein of approximately 33 kDa in both rat retina and rat pineal. The amino acid sequence of rat pineal phosducin is homologous to that of bovine retina phosducin, revealing 89% identity and another 5.7% similarity. Both rat pineal and bovine retina phosducins are acidic proteins with pIs of 4.3 and 4.5, respectively. The translated protein lacks hydrophobic domains that would suggest an integral membrane protein. Rat pineal phosducin has a single consensus phosphorylation domain for protein kinase A that is nearly identical to that of retinal phosducin, which is phosphorylated by protein kinase A in situ. Rat phosducin also contains three potential phosphorylation domains for protein kinase C and nine for casein kinase II as well as a predicted site for N-glycosylation. The cDNA encoding phosducin was used to localize the gene within a linkage group to a large segment of mouse chromosome 1 in a conserved region with the long arm of human chromosome 1 with a panel of DNA samples from an interspecific cross. In keeping with a proposed role of retinal phosducin in down-regulation of the photo-transduction cascade, a modulatory role in signal transduction is proposed for pineal phosducin.     

Versatile Method for Evaluating a Cell Culture by Various Morphological Techniques

Cellulose acetate is a versatile material for evaluating cells grown under identical conditions by various morphological techniques. This inexpensive material is transparent, easily cut to size and shape, nontoxic to cell cultures, and resistant to most chemicals used in histochemistry and in scanning and transmission electron microscopy. Samples may be obtained during and after the culture process. Cellulose acetate slides can be mounted directly over glass slides for direct observation and are easily peeled off plastic blocks for electron microscopy, leaving the cells behind. Relative disadvantages include its autofluorescence and a tendency to soften in strong acids or pure solutions of organic solvents such as xylene and propylene oxide.     

Evaluation of burn blister fluid

Although edema is evident immediately after a burn, the diffusion of nutrient chemical constituents of the body is not impaired. Blister fluid, not unlike plasma or serum, contained all substances found in the body, including parenterally administered penicillin. The elevation of potassium and the cation to anion imbalance is primarily due to the Na/K cellular pump malfunction, and the destruction of the permeability of the cell membrane is most likely a direct result of complement and other cellular enzymes, which include the prostaglandins and thromboxanes. The elevated SGOT, CPK, and LDH indicated severe trauma to the cells in the immediate area of burn and possibly to the skeletal muscle. The presence of immunoglobulins indicated that high-molecular-weight proteins diffuse equally well during this edematous phase (IgM, 900,000; IgG, 190,000). Evidence of this nature strongly suggests that the integrity of the burn blister by maintained.