Characterization of horA and its flanking regions of Pediococcus damnosus ABBC478 and development of more specific and sensitive horA PCR method

AIMS: To characterize horA and its flanking regions of Pediococcus damnosus ABBC478 and, on the basis of this insight, to develop a more specific and sensitive horA PCR method. METHODS AND RESULTS: A plasmid harbouring the homologue of a hop-resistance gene, horA, was sequenced and designated pRH478. The nucleotide sequence and open reading frame structure of horA and its flanking regions of pRH478 were found to be highly similar to those of pRH45, a horA-harbouring plasmid previously identified in Lactobacillus brevis ABBC45. The nucleotide sequence of the horA homologue of P. damnosus ABBC478 was 99.6% identical with that of horA. Based on this insight, new primers specific to horA were designed and compared with the previously reported specific primer pair. As a consequence, it was demonstrated that the new primer pair is superior in specificity and sensitivity. CONCLUSIONS: The newly developed horA PCR method allows more specific and sensitive determination of the beer-spoilage ability of lactic acid bacteria (LAB). SIGNIFICANCE AND IMPACT OF THE STUDY: The nucleotide sequences of the horA homologues were found to be essentially identical among distinct species of LAB, indicating that horA-specific primers can be designed from almost any region of the horA gene.     

Direct comparison between ICSI-mediated DNA transfer and pronuclear DNA microinjection for producing transgenic rats.

Production efficiency of transgenic rats was compared directly between the routine pronuclear microinjection of exogenous DNA solution (PNMI-Tg method) and the ooplasmic injection of sperm cells exposed to exogenous DNA solution (ICSI-Tg method) using six DNA constructs. The overall production efficiency per treated oocyte in the ICSI-Tg method (mean 1.1%, range 0.2 to 3.1%) was similar to that in the PNMI-Tg method (mean 1.1%, range 0 to 2.4%). An advantage of the ICSI-Tg method in the production of transgenic rats is noted in cases in which a low yield of pronuclear zygotes is an inevitable fate of the rat strain.     

Serum free thyrotropin subunit in congenital isolated thyrotropin deficiency

In two patients with congenital isolated thyrotropin (TSH) deficiency, serum TSH determined by a sensitive immunoradiometric assay (IRMA) was consistently undetectable. The basal levels of serum free TSH-alpha subunit (TSH-alpha) determined by a specific radioimmunoassay (RIA) were elevated in the hypothyroid state, and decreased to the undectable level during displacement therapy with thyroid hormone. The serum free TSH-alpha significantly increased following intravenous administration of thyrotropin releasing hormone (TRH). Serum free TSH-beta subunit (TSH-beta) was undectable. These findings suggest that TSH deficiency in this disease is not due to absence of thyrotroph in the pituitary gland or deficiency of TSH-alpha, but to abnormalities of the TSH-beta gene.     

Effects of stereoregular poly(acrylic acid)s on hydrolysis rate of p-nitrophynyl acetate by α-chymotrypsin

The interaction of α-chymotrypsin with poly(acrylic acid)s (PAA) having different stereoregularities and molecular weights has been studied through the effects of α-chymotrypsin on enzymic hydrolysis of $\text{p-}\text{nitrophenyl}$ acetate (NpOAc). The results show that isotactic PAA inhibits the hydrolysis more strongly than do atactic and syndiotactic PAAs. The inhibition constant or the dissociation constant of the reactio-inhibiting PAA α-chymotrypsin complex decrease with increasing molecular weight of PAA.     

Studies on griseolic acid derivatives. III. Synthesis and biological activities of the adducts of griseolic acid and their base exchanged derivatives

Addition reactions across the double bond of griseolic acid were investigated. Dihydrogriseolic acid was obtained by a reduction of the adduct having halogen at 4' position. The ring juncture of the two five membered rings of the dihydro derivatives was all "cis" configuration. An acetolysis of the protected dihydro derivative gave corresponding 1'-acetoxy sugar. A glycosidation of this sugar derivative with silylated bases gave base exchanged derivatives of the dihydrogriseolic acid. The influence of the base moiety and the double bond to the PDE inhibitory activity was investigated. As a result, we found that this type of compounds had a weaker inhibitory activity than the corresponding compounds which had an original double bond or a dihydro bond that made the ring juncture of the two five membered ring "trans".     

Immunohistochemical studies on GABAergic neurons in the rat locus coeruleus, with special reference to their relationship to astrocytes

Purified antisera against GABA were prepared. A few small GABAergic neurons in the rat locus coeruleus were immunohistochemically demonstrated by both the unlabeled peroxidase-antiperoxidase method and the avidin-biotin peroxidase complex method using affinity-purified GABA antibodies. The glial fibrillary acidic protein immunoreactivity in this nucleus was localized by the latter method in the astrocytal framework encircling medium-sized and small neurons as well as in straight processes. Astrocytes may play a role as energy donors to these neurons.     

Colocalization of glucagon-like peptide and glucagon immunoreactivities in pancreatic islets and intestine of salmonids

Summary Pancreatic islets of salmon contain at least two peptides of the glucagon family: 29-amino acid glucagon and 31-amino acid glucagon-like peptide (GLP). Both peptides were recently isolated from the pancreatic islets of coho salmon and sequenced (Plisetskaya et al. 1986). Antibodies generated against these two peptides and against human glucagon were used as immunocytochemical probes to investigate whether glucagon and GLP are processed in the same, or in different cell types in the pancreatic islets and the gut of salmon. Two salmonid species, rainbow trout and coho salmon, were studied. All islet A-cells in the two species were immunoreactive toward both anti-salmon (s)-glucagon and anti-s-GLP. Similar colocalization of glucagon and GLP immunoreactivities was found in open-type endocrine cells in mucosae of the small intestine (including the pyloric coecae) and the large intestine close to the vent of rainbow trout. None of the antibodies stained mucosal cells of the body of the stomach. These results suggest that in the pancreas and the gut of salmonid fish the same cells produce both glucagon and GLP. These peptides are most likely the products of a single gene coding for the preproglucagon sequence.     

Relationship between specific leaf area of aCryptomeria japonica foliage shoot segment and its diameter

Dependency of specific leaf area (SLA) on shoot diameter (x) was studied forCryptomeria japonica foliage shoot segments about 5 cm in length taken from 18 branches at different height levels on 3 trees in August 1987. The leaf area of a shoot segment (S) was defined as half the sum of the needle area (s) estimated by the allometric relationship betweens and needle length. The dry weight of woody tissue (W _w) and needles (W _n) of a segment and itsS were divided by the segment length (L) to give linear densities asW _w/L,W _n/L andS/L, respectively. The densities were related tox by power-form equations.S/L values tended to be constant around 1.2 [cm² cm⁻¹] within the discussed range ofx, whileW _w/L andW _n/L values clearly increased withx. The approximately reciprocal relationship between average needle area (s) and linear density of the number of needles supported the fact thatS/L values were roughly constant regardless ofx.SLA andSNA were defined asS/(W _w+W _n) andS/W _n, respectively. TheSLA-x relationship expected from the average value ofS/L and theW _w/L-x and theW _n/L-x relationships was well fitted to the observed decrease inSLA with increasingx. SNA also decreased asx increased. Variations inSLA andSNA among the shoot segments with similarx were not systematically related to their height levels. An empirical equation with a maximum value ofx (Xmax) was also proposed in order to formulate theSLA-x relationship.     

On-off regulation of gene expression from tryptophan promoter with cross-flow filtration

Summary Recombinant plasmid containing β-galactosidase gene fused to trp promoter (pMCT98) and that containing cloned trp repressor gene (pRLK13) were introduced into Escherichia coli C600. The bacterium was cultivated in a jar-fermetor equipped with a cross-flow filtration apparatus to attain the on-off regulation of the gene expression by controlling tryptophan concentration in the medium. In logarithmic growth phase, the cross-flow filtration was started. Tryptophan concentration dropped to a low level within 1 h and an efficient expression of β-galactosidase gene was started. By this twostage cultivation, very high biomass was achieved (final OD₅₇₀: 150) and the amount of produced β-galactosidase was about 10% of total cellular proteins.     

Mortality and survival for Down syndrome in Japan.

Mortality and survival data for 1,052 Japanese patients with Down syndrome who were born between 1966 and 1975 were analyzed. The survival rate at age 10 was estimated to be about 86%. Mortality in each age group for Down syndrome was elevated over that of the general population. In the survival rate at age 10, there was no significant difference between males and females, but the difference between cases with and without congenital heart disease was highly significant. Using data from this study-for mortality up to age 10-and from the study of institutionalized cases for mortality over age 10, a hypothetical life table was constructed; it shows that the life expectancy at birth for cases with Down syndrome is nearly 50 years.