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Protein kinase C (PKC), a family of closely related enzymes, has been implicated in molecular processes involved in differentiation in a variety of cells, including neuronal cells. We studied the presence and distribution of four PKC isozymes immunocytochemically in primary neuronal cultures of the rat cerebellum. We employed four anti-PKC antisera raised against synthetic peptides predicted from the cDNA sequence of the C-terminal portion of four PKC isozymes, alpha, beta I, beta II, and gamma. The majority of neurons were PKC(beta II) immunoreactive both in the early and late (14 days) stage of culture, whereas PKC(alpha)-, (beta I)-, and (gamma)-immunoreactive neurons were most abundant in the late stage of culture. Immunoreactivity of each PKC was high in the cytoplasm, processes, and growth cones. Prominent nuclear staining was observed with anti-PKC(gamma) antibody. These results are in contrast with in vivo results where each PKC isozyme is localized in a distinct population of neurons and subcellular compartment, suggesting the presence of regulatory mechanisms for PKC expression and compartmentalization in vivo.

The time course of NADPH-diaphorase expression was examined in primary cultures of rat central nervous system and in embryonic or neonatal rat brains using a histochemical method. In cerebral and brainstem cultures from 17-day-old embryonic rats, neuronal cells moderately expressing NADPH-diaphorase were first detected on about the 5th to 7th day of culturing. Both the density of positive cells and the staining intensity increased with age of cultures. The density of positive cells, calculated as a percent of the total number of cells, increased up to day 21 in cultures from both the cerebrum and the brainstem, indicating that NADPH-diaphorase is preferentially expressed in neurons with longer viability. On the other hand, virtually no intensely positive cells were detectable in cerebellar cultures at any period examined up to 21 days. In the in vivo study, moderately stained NADPH-diaphorase-positive neurons were first detected, mainly in the laterodorsal-pedunculopontine tegmental nuclei complex and partly in the striatum, in 16-day-old embryonic rat brain. At 2 days postnatal, intensely stained neurons were detectable in the cerebral cortex as well as in the tegmental nuclei complex and the striatum, indicating some delay in the in vitro, as compared to the in vivo, expression of neuronal NADPH-diaphorase.

The braZ gene for a novel branched-chain amino acid transport system in Pseudomonas aeruginosa PAO was isolated and characterized. Determination of the nucleotide sequence showed that the braZ gene comprises 1,311 nucleotides specifying a protein of 437 amino acids. Hydropathy analysis suggested that the product is an integral membrane protein with 12 membrane-spanning segments. The amino acid sequence showed extensive homology to those of the braB and brnQ gene products, branched-chain amino acid carriers of P. aeruginosa and Salmonella typhimurium, respectively. By using the T7 RNA polymerase-promoter system, the braZ gene product was identified as a protein of an apparent Mr of 34,000 on a sodium dodecyl sulfate-polyacrylamide gel. Properties of the transport system encoded by braZ were studied by using P. aeruginosa PAO3537, defective in both the high- and low-affinity branched-chain amino acid transport systems (LIV-I and LIV-II, respectively). The transport system encoded by braZ was found to be another effective branched-chain amino acid transport system in P. aeruginosa PAO and was thus designated as LIV-III. This system is specific for isoleucine and valine, giving the same Km value of 12 microM for these amino acids. The system was found, however, to have a very low affinity for leucine, with a Km value of 150 microM, which contrasts with the substrate specificities of LIV-I and LIV-II.

During the aerobic digestion process, the nitrogen which had been embedded in the activated sludge is solubilized to form ammoniacal and nitric nitrogen which are in turn transferred to the liquor and cause the increase of nitrogen loading in the sewage treatment plant. In this study, the anoxic-aerobic sludge digestion system which is a modified form of the conventional aerobic sludge digestion is made up of aerobic and anoxic tanks and are designed to remove both the volatile suspended solids and the total nitrogen (TN) simultaneously. The removal efficiencies of both VSS and TN were investigated by feeding waste-activated sludge continuously and semicontinuously. The maximum percent reduction of both VSS and TN was achieved at a Q(r)/Q(s) ratio of 2 in the continuous process. The semicontinuous process was used to improve the nitrogen removal efficiency further. In the semicontinuous process, the VSS reduction efficiency as well as the nitrogen removal efficiency increased remarkably under a constant Q(r)/Q(s) ratio of 2. This process also achieved a VSS reduction efficiency higher than the aerobic digestion process (control). It was suggested that the additional anoxic tank enhanced the sludge digestion. Furthermore, the anoxic-aerobic digestion system can be applied to other treatment media like the primary sludge, industrial sludge, animal manure, etc.

The optical-wavelength-division multiplexer reported here is composed of three multimode fiber pieces with dielectric multilayers evaporated on the ends of the fibers, which have been polished obliquely or squarely. The working faces of these fibers are bonded together in a crossed V groove to duplex two wavelengths (lambda = 0.82 and 1.2 microm). The far ends of the joined fiber pieces are left intact for splicing with fiber cables or are terminated with connector ferrules for connection. The multiplexer is small (1 cm square) and lightweight (1.5-3 g). It also shows low insertion loss (1 dB) and cross-talk level (below -40 dB). We have estimated that the cost of this type of component can be reduced to I order of magnitude lower than that of conventional lens and mirror types.