Role of the prepositus hypoglossi nucleus on primary position upbeat nystagmus

Electrolytical destruction of the floor of the fourth ventricle was performed on 10 cats in order to produce primary position upbeat nystagmus (PPUN). In 5 cats who had unilateral lesions of the floor of the fourth ventricle, PPUN was never seen. Two of the remaining 5 cats, who had bilateral lesions, showed PPUN. In 2 cats with PPUN, the oculomotor level of the caudal fourth ventricle, in order that PPUN may be developed, it is necessary that the prepositus hypoglossi nucleus (PH) be destroyed bilaterally. The present experiment suggests that bilateral PH lesions could result in a tonic imbalance for eye positions and eye movements of the vertical axis, resulting in a downward drift with a corrective saccade; PPUN.

Hemolytic toxin produced by Porphyromonas gingivalis

Porphyromonas gingivalis no. 381 and ATCC 33277 produced an extracellular hemolytic toxin which was heat-labile, trypsin-sensitive, and lytic to human, horse, sheep and rabbit erythrocytes. The hemolytic toxin is a 'hot-cold', thiol-independent toxin. The production of the hemolytic toxin was greatly enhanced by addition of hemoglobin to the culture medium.

Molecular cloning and cDNA sequencing of endoxyloglucan transferase, a novel class of glycosyltransferase that mediates molecular grafting between matrix polysaccharides in plant cell walls

Endoxyloglucan transferase is a novel class of glycosyltransferase recently purified from Vigna angularis (Nishitani, K,, and Tominaga, R. (1992) J. Biol. Chem. 267, 21058-21064). This enzyme is the first transferase identified that catalyzes molecular grafting between polysaccharide cross-links in the cell wall matrix and participates in reconstruction of the network structure in the cell wall. Based on the NH2-terminal amino acid sequence information of the purified transferase, we have here cloned and sequenced cDNAs derived from five different plant species, V. angularis, Triticum aestivum, Arabidopsis thaliana, Lycopersicon esculentum, and Glycine max. In the five plant species, the amino acid sequence of the mature proteins is conserved in the range of 71-90% throughout their length. The consensus sequence for N-linked glycosylation, and four cysteine residues are all conserved in the five species. Thus, the endoxyloglucan transferase protein is ubiquitous among higher plants. The highly conserved DNA sequence will serve as a promising tool for exploring the molecular process by which cell wall construction, and hence cell growth, is regulated.

Improved method for expression of Kunitz-type serine proteinase inhibitor domain of beta-amyloid protein precursor in Escherichia coli and characterization of disulfide bonds of the product

Kunitz-type serine proteinase inhibitor (KPI) domain of Alzheimer's disease-related beta-amyloid protein precursor (APP) was expressed in Escherichia coli as a fusion protein with a truncated form of Staphylococcus protein A. The fusion protein was purified from the cell culture medium using an IgG Sepharose column. The KPI domain was separated from the protein A portion by cleavage with human alpha-thrombin at the engineered recognition sequence, followed by purification on IgG Sepharose and reversed-phase HPLC columns. The recombinant KPI domain strongly inhibited trypsin; the inhibition constant (Ki) for bovine trypsin was 2.5 x 10(-11) M, comparable to those of the secreted forms of APP with the KPI domain. The recombinant protein contained three intramolecular disulfide bonds, which were determined to be located between Cys-6 (C1) and Cys-56 (C6), Cys-15 (C2) and Cys-39 (C4), and Cys-31 (C3) and Cys-52 (C5) of the recombinant KPI domain, respectively. These positions are highly homologous to those of disulfide bonds in bovine pancreatic trypsin inhibitor. The trypsin-inhibitory activity of the recombinant protein was abolished by preincubation with 0.4 mM dithiothreitol under non-denaturing conditions. By this mild reduction, all the disulfide bonds were completely cleaved. These results clearly indicate that the disulfide bonds play an important role in the function of the KPI domain of APP.

Alpha-amylase from the hyperthermophilic archaebacterium Pyrococcus furiosus. Cloning and sequencing of the gene and expression in Escherichia coli

A gene encoding a highly thermostable alpha-amylase from the hyperthermophilic archaebacterium Pyrococcus furiosus was cloned and expressed in Escherichia coli. The nucleotide sequence of the gene predicts a 649-amino acid protein with a calculated molecular mass of 76.3 kDa, which corresponds well with the value obtained from purified enzyme using denaturing polyacrylamide gel electrophoresis. The NH2 terminus of the deduced amino acid sequence corresponds precisely to that obtained from the purified enzyme, excluding the NH2-terminal methionine. The amylase expressed in E. coli exhibits temperature-dependent activation characteristic of of the original enzyme from P. furiosus, but has a higher apparent molecular weight which is attributed to the improper formation of the native quaternary structure. No homology was found with previously characterized promotor or termination sequences. The deduced amino acid sequence displayed strong homology to the alpha-amylase A of Dictyoglomus thermophilum, an obligately anaerobic, extremely thermophilic bacterium. Evolutionary implications of this homology are discussed.

Prevalence of type 2 (non-insulin-dependent) diabetes mellitus and impaired glucose tolerance in the Japanese general population: the Hisayama Study

We determined the population-based prevalence of diabetes mellitus in members of the Japanese community, Hisayama aged 40-79 years old by a 75-g oral glucose tolerance test. The basic population used to calculate diabetic prevalence was 1,077 men (72.8% of the whole population in the same age range) and 1,413 women (80.8%) including ten diabetic patients on insulin therapy. In addition, we compared the prevalence of history of diabetes which was acquired by interview or questionnaire, between participants and non-participants in the 75-g oral glucose tolerance test, but they were not statistically different. The age-adjusted prevalence of diabetes to world population was 12.7% for men and 8.4% for women, and that of impaired glucose tolerance was 19.6% for men and 18.4% for women. These figures were much higher than those previously reported from several Japanese communities. The results obtained from the present study could reveal true prevalence of diabetes among the Japanese population. In addition, the reasons for the increasing prevalence of diabetes among the recent Japanese population are also discussed.

Purification and characterization of an enzyme releasing lacto-N-biose from oligosaccharides with type 1 chain

An enzyme specific for oligosaccharides with type 1 chain was purified 7,000-fold from the culture broth of Streptomyces sp. 142. The enzyme, lacto-N-biosidase, was induced and secreted into culture medium when the strain was cultured in the presence of porcine stomach mucin. The enzyme was purified by anion-exchange chromatography on Q Sepharose, cation-exchange chromatography on S Sepharose, fast protein liquid chromatography on a Mono S column, and gel filtration chromatography on TSK gel HW55S. To remove contaminating alpha-1,3/4-fucosidase and beta-N-acetylglucosaminidase, final purification was done by fast protein liquid chromatography on a Mono S column and affinity chromatography on N-acetylglucosamine agarose. The purified enzyme gave only one major protein band with an apparent M(r) of 60,000 on sodium dodesyl sulfate-polyacrylamide gel electrophoresis. The enzyme had maximum activity at pH 5.5 and was stable at the pH range of 4.0-10.0. Substrate specificity studies with oligosaccharides labeled with 2-aminopyridine showed that the enzyme specifically hydrolyzed lacto-N-tetraose and the N-acetyllactosamine type of triantennary sugar chain with the type 1 chain, but did not hydrolyze type 2 chain oligosaccharides or the type 1 chain oligosaccharides with fucose or sialic acid including lacto-N-fucopentaose I and II and alpha-2,3-sialyl lacto-N-tetraose. The enzyme released lacto-N-biose from asialofetuin, and almost all oligosaccharides in asialofetuin were found to have only type 2 chains. Sequential digestion of extended type 1 chain oligosaccharides with alpha-1,3/4-fucosidase and lacto-N-biosidase was possible.

NADP(+)-dependent D-threonine dehydrogenase from Pseudomonas cruciviae IFO 12047

NADP(+)-dependent D-threonine dehydrogenase (EC 1.1.1.-), which catalyzes the oxidation of the 3-hydroxyl group of D-threonine, was purified to homogeneity from a crude extract of Pseudomonas cruciviae IFO 12047. The enzyme had a molecular mass of about 60,000 Da and consisted of two identical subunits. In addition to D-threonine, D-threo-3-phenylserine, D-threo-3-thienylserine, and D-threo-3-hydroxynorvaline were also substrates. However, the other isomers of threonine and 3-phenylserine were inert. The enzyme showed maximal activity at pH 10.5 for the oxidation of D-threonine. The enzyme required NADP+. NAD+ showed only slight activity. The enzyme was not inhibited by EDTA, o-phenanthroline, alpha,alpha'-dipyridyl, HgCl2, or p-chloromercuribenzoate but was inhibited by tartronate, malonate, pyruvate, and DL-2-hydroxybutyrate. The inhibition by these organic acids was competitive against D-threonine. Initial-velocity and product inhibition studies suggested that the oxidation proceeded through a sequential ordered Bi Bi mechanism. The Michaelis constants for D-threonine and NADP+ were 13 and 0.12 mM, respectively.

Biological properties of aureobasidin A, a cyclic depsipeptide antifungal antibiotic

Aureobasidin A (AbA) is a novel cyclic depsipeptide antifungal antibiotic. The antifungal activity of AbA was studied in vitro and in vivo in comparison with clinically effective antifungal agents, amphotericin B and fluconazole. AbA was highly active in vitro against many pathogenic fungi, including Candida albicans, Cryptococcus neoformans, Blastomyces dermatitidis and Histoplasma capsulatum. The activity was superior to amphotericin B in most cases. AbA exhibited fungicidal action toward growing cultures of C. albicans. It was highly tolerated by mice and showed good efficacy in the treatment of murine systemic candidiasis when given orally or subcutaneously. AbA's fungicidal action in mice with candidiasis was more effective than fluconazole and amphotericin B.

Direct projection from the nucleus of the optic tract to the medial vestibular nucleus in the cat

The nucleus of the optic tract (NOT) serves as an important visuo-motor relay between the retina and preoculomotor structures that mediate optokinetic nystagmus. In the present study, the efferent targets of NOT were investigated using biocytin as an anterograde tracer. Following biocytin injections into NOT, labeled fibers were observed in each of the following efferent pathways: (1) those that project to the contralateral NOT via the posterior commissure; (2) those that course through the nucleus reticularis pontis oralis to terminate in the nucleus reticularis tegmenti pontis; and (3) those that descend via the medial lemniscus to the level of the medulla to terminate in the dorsolateral pontine nucleus, nucleus prepositus hypoglossi, medial vestibular nucleus and the inferior olive. Direct projections from the NOT to the medial vestibular nucleus may contribute to the residual optokinetic responses of the vestibular nucleus neurons following cerebellar or inferior olivary lesions.

A cross-sectional study on osteocalcin levels in gingival crevicular fluid from periodontal patients

The purpose of the present study was to determine the levels of osteocalcin, a bone specific matrix protein, in gingival crevicular fluid (GCF) from periodontal disease patients and to investigate the relationship between GCF osteocalcin levels and clinical parameters. Nineteen initial visit patients, 5 patients with gingivitis and 14 patients with adult periodontitis, participated in this study. The clinical parameters including probing depth, attachment level, gingival index, and tooth mobility were recorded following careful sampling of GCF with a filter paper strip harvested for 3 minutes. Osteocalcin adsorbed on a strip was extracted in a plastic tube containing 150 microliters of 10 mM sodium phosphate buffer (pH 6.5). GCF osteocalcin was determined by a newly-developed, high sensitive enzyme immunoassay which could recognize the N-terminal 20 residue peptide. In gingivitis patients, no significant amounts of osteocalcin were detected. In periodontitis patients, on the other hand, osteocalcin levels were detected, ranging between 0 and 540 pg/tube and positively correlated with these clinical parameters (P < 0.01). Moreover, in several sites in GI = 3 group, extremely higher levels of GCF osteocalcin were detected. These results strongly suggest that in addition to the presence of GCF osteocalcin the levels of osteocalcin may reflect the degree of the periodontal inflammation at the sampled sites.

Isolation, structures, and antifungal activities of new aureobasidins

Aureobasidins are a group of cyclic depsipeptides with antifungal activity and are produced by Aureobasidium pullulans. Aureobasidins are composed of eight amino acids and one hydroxy acid such as 2-hydroxy-3-methylpentanoic acid (Hmp), and highly lipophilic. Five new aureobasidins, S1, S2a, S2b, S3 and S4, which have higher hydrophilicity in reversed phase HPLC than the known aureobasidins A-R, were discovered in a fermentation broth of A. pullulans R106 by means of on-line liquid chromatography/mass spectrometry with electrospray ionization. We identified the structures of the compounds and studied their antifungal activities. Three of the new aureobasidins, S2b, S3 and S4, which have hydroxylated Hmp as the hydroxy acid, were highly active against Candida spp. and Cryptococcus neoformans.

Increased fragmentation of urinary fibronectin in cancer patients detected by immunoenzymometric assay using domain-specific monoclonal antibodies

Monoclonal antibodies (MoAbs) recognizing the distinct domains of human fibronectin had previously been established and they were used to construct several sandwich immunoenzymometric assays (IEMAs) for the structural analysis of fibronectin found in the urine of cancer patients. Urinary fibronectin (UFN) was immunodetectable only with FN12-8 and FN30-8 MoAbs against cell-binding domains and was less reactive with other IEMAs using MoAbs directed to terminal domains, indicating that UFN was almost completely fragmented and consisted mainly of cell-binding regions. The IEMA using MoAbs against cell-binding domains had sufficient immunoreactivities with the antigen fragmented by artificial proteolysis, but these fragments could hardly be detected by other IEMAs. UFN levels were significantly elevated in various cancer patients and extremely elevated in some patients with distant metastasis. It is presumed that UFN fragments which increase in cancer patients are generated by extracellular matrix destruction. Thus UFN levels and the ratio of the fragmented UFN level to the non-fragmented UFN level appear to be informative clinical indicators of tumor malignancy or metastatic ability in cancer patients.

The nucleotide sequence of human aminoacylase-1

The nucleotide sequence of a cDNA coding for human aminoacylase-1 (N-acylamino acid aminohydrolase, ACY-1, EC 3.5.1.14) subunit has been determined. The amino acid sequence of human ACY-1 subunit deduced from its cDNA nucleotide sequence showed a high degree of identity (87.7%) with the corresponding protein from porcine [1], although the former is one amino acid residue longer than the latter. Of 12 histidine and 3 cysteine residues, conserved between the proteins from two species, some are anticipated to form the active site of ACY-1 as either catalytic residues or ligands for an essential Zn2+ atom.

Cholera toxin directly stimulates pregnenolone generation with increasing Ca2+ efflux in bovine adrenocortical mitochondria

The present experiments demonstrated that the holotoxin as well as the A- and B-subunits of cholera toxin were able to directly enhance pregnenolone synthesis when isolated intact mitochondria, prepared from bovine adrenocortical tissue, were incubated; they were not, however, able to enhance pregnenolone synthesis when the inner mitochondrial fraction was similarly incubated, suggesting that the conformational structure of mitochondria is very important for activation of cholesterol side-chain cleavage by cholera toxin. Data are also presented demonstrating that cholera toxin can enhance Ca2+ release from isolated mitochondria, while pertussis toxin could activate neither pregnenolone generation nor increase Ca2+ efflux from mitochondria. Thus it is suggested that cholera toxin may activate pregnenolone synthesis by regulating Ca2+ movement in mitochondria.

Changes in the susceptibility of 12-O-tetradecanoylphorbol 13-acetate (TPA)-treated HL-60 cells to staphylococcal leukocidin

Susceptibility of human promyelocytic leukemia HL-60 cells to staphylococcal leukocidin following treatment of cells with 12-O-tetradecanoylphorbol 13-acetate (TPA) was examined. TPA treatment for 6 hr rendered the cells very resistant transiently to leukocidin. There was no change in binding of leukocidin to the cells, but leukocidin-induced 45CaCl2 influx, phospholipase A2 and C activities were inhibited. Further incubation with TPA rendered the cells sensitive again and then more sensitive than original HL-60 cells following increase of the binding, and leukocidin-induced activities described above appeared again. Those cells treated with TPA for more than 18 hr started to differentiate to macrophages morphologically and functionally. These data suggest that the differentiated cells were more sensitive than original HL-60 cells because of increased binding of leukocidin and that treatment of TPA for 6 hr may transiently impair the signal transduction system of leukocidin after binding of leukocidin to the specific receptor of the cell membrane. Using these TPA-treated cells, it was shown in this report that calcium influx, phospholipase A2 and C activities were important to induce cytotoxic action of leukocidin after binding of leukocidin to specific receptors on the cells.

[Hyperinsulinemia and hypertension in an elderly Japanese population--the Hisayama Study]

Hyperinsulinemia has been closely associated with hypertension in several epidemiological studies, but little is known about this condition in the elderly. The authors studied the relationship between serum insulin and blood pressure levels, and the prevalence of hypertension according to insulin levels in the elderly in a Japanese rural community, Hisayama. In 1988, 75 g oral glucose tolerance test was performed on 426 male and 567 female Hisayama residents aged 60 to 79 years. Fasting and 2 hr serum insulin values were measured by radioimmunoassay. In the subjects, excluding those receiving antihypertensive drugs, the sum of fasting and 2 hr postload insulin (sigma IRI) significantly correlated with systolic (r = 0.15 and 0.25 for males and females, respectively) and diastolic blood pressure (r = 0.20, 0.16). In multiple regression analyses, the correlation with systolic blood pressure remained significant in females after controlling for age, body mass index, alcohol intake, smoking habits, serum total cholesterol, HDL-cholesterol, triglycerides, and fasting plasma glucose. In contrast, sigma IRI did not remain as an independent variable relevant to blood pressure among males. The age-adjusted prevalence rates of hypertension (> or = 160/95 mmHg or receiving drug treatment) significantly increased with increasing quartiles of sigma IRI in females. The prevalence of hypertension which was not treated with drugs also increased significantly with increasing sigma IRI in females. However, no significant association was observed in males. In conclusion, the present study suggests that hyperinsulinemia can be related to hypertension in the female elderly in the general population of Japan.

Purification and characterization of beta-N-acetyl-D-hexosaminidase from the mid-gut gland of scallop (Patinopecten yessoensis)

beta-N-Acetyl-D-hexosaminidase was isolated from the mid-gut gland of Patinopecten yessoensis. The enzyme was purified by making an acetone-dried preparation of the mid-gut gland, extracting with 50 mM citrate-phosphate buffer (pH 4.0) (about 13% of the extracted proteins was beta-N-acetyl-D-hexosaminidase), ammonium sulfate fractionation, and column chromatographies on CM-Sepharose and DEAE-Sepharose. The purified beta-N-acetyl-D-hexosaminidase was homogeneous on SDS-PAGE, and sufficiently free from other exo-type glycosidases. The molecular weight was 56,000 by SDS-PAGE. The enzyme hydrolyzed both p-nitrophenyl beta-N-acetyl-D-glucosaminide and p-nitrophenyl beta-N-acetyl-D-galactosaminide. For p-nitrophenyl beta-N-acetyl-D-glucosaminide, the pH optimum was 3.7, the optimum temperature was 45 degrees C, and the Km was 0.24 mM. For p-nitrophenyl beta-N-acetyl-D-galactosaminide, these were pH 3.4, 45 degrees C, and 0.15 mM, respectively. The enzyme liberated non-reducing terminal beta-linked N-acetyl-D-glucosamine or N-acetyl-D-galactosamine from various 2-aminopyridyl derivatives of oligosaccharides of N-glycan or glycolipid type except of GM2-tetrasaccharide. As the enzyme was stable around pH 3.5-5.5, it may be useful for long time reactions around the optimum pH.

Practical application of fluorescence-based image analyzer for PCR single-stranded conformation polymorphism analysis used in detection of multiple point mutations

We present a practical application of polymerase chain reaction single-strand conformational polymorphism (PCR-SSCP) using a fluorescence-based image analyzer. Fluorescence-labeled primers were used to amplify target sequences. After nondenaturing polyacrylamide gel electrophoresis using a conventional sequencing gel apparatus, the glass plate was directly transferred from the gel box to the image analyzer. High-quality computer storage of the imaging data allowed the image intensity to be quantified over a wide range. Various data bases can be constructed on the basis of this imaging data. This system is suitable for use in clinical examination settings, and its application, to detect ras gene mutations in human pancreatic cancer specimens, is presented.