Search PubMed⌕ Search

Biomedical subjects

N Goto

Publications and source records attributed to N Goto.

At least 217 records · Page 12Linked to original sources
PubMed1993

[Adrenocortical zonation in the laboratory Japanese field vole (Microtus montebelli)].

Adrenocortical zonation in the laboratory Japanese field vole (Microtus montebelli) was investigated histologically with special attention to the sex and species specific differences. The whole cortex and zona reticularis showed clear sex differences. They were thicker in females than in males. In this respect the vole was similar to the mouse and rat, but different from the Syrian hamster and mastomys. Male cortices were characterized by thick z. fasciculata and meagre z. reticularis, while both zones were thick in females. The z. fasciculata in both sexes and z. reticularis in females seemed to be divided into two sublayers by the cellular arrangement. No distinctive additional zones were identified. The histological observations indicated that the Japanese field vole might have interesting endocrinological characteristics and serve for studying the mechanism of the zone formation in the mammalian adrenal cortex.

Adrenal Cortex↗
PubMed1993

[Application of DNA fingerprinting to investigation of genetic relationships between laboratory rabbit strains].

It is well known that laboratory rabbits are not controlled genetically like laboratory mice and rats. In order to test the usefulness of DNA fingerprinting in investigation of genetic uniformity of the laboratory rabbits strains and their relationships, we applied DNA fingerprinting using bacteriophage M13 probe to five strains (2 inbreds (JWY-NIBS and DuY-NIBS) and 3 outbreds (JW-NIBS, Icl:JW and WHHL)). DNA fingerprints of 2 inbred strains showed the same banding patterns within each strain but the strain-specific patterns. Although there were no rabbits showing the same banding patterns in 3 outbred strains, average percent differences (APD) were 13.7 to 18.6. A dendrogram based on APD of DNA fingerprints was constructed by 2 large clusters, JW group and DuY. The dendrogram was essentially similar to that based on rabbit mandible measurements. These results suggest that DNA fingerprinting is available not only for the genetic monitoring of the laboratory rabbit strains but also for the investigation of their genetic relationships.

Animals↗
PubMed1993

Establishment of inbred strain of long-haired golden hamster.

Features of a long-haired mutant and inheritance of mutation were investigated in the golden hamster (Mesocricetus auratus). The hair of adult long-haired hamsters was longest at the rump and flanks (approximately 70 mm) and was also unusually long at the neck (45 to 50mm). The hair length of males was more striking than that of females. Mating experiments indicated that an autosomal recessive gene is responsible for the inheritance of long hair. An albino long-haired hamster strain was established by continuous full-sib mating from F2 hybrids, descendants of (acromelanic albino x agouti long-haired) F1 progeny, and genetic homogeneity was confirmed by DNA fingerprinting. The long-haired strain was characterised by the fact that males grew larger than females, in contrast to the other strains of hamsters.

Animals↗
PubMed1993

[Relative growth of physiques in laboratory-bred cynomolgus monkeys: a longitudinal study during the first 6 years of life].

Physical growth was studied longitudinally in laboratory-bred cynomolgus monkeys (Macaca fascicularis) aged from birth to 6.0 years in females and to 6.5 years in males. An allometric formula was applied to morphometrical growth data and the relative growth of each morphological site to anterior trunk length was analyzed. The growth patterns of all of the measurement sites in females and most of the sites in males showed monophasic allometry; while those of head length, head breadth and morphological upper face length in males were judged to show diphasic allometry. The growth patterns of morphological total face length, upper arm length and lower arm length in some males showed diphasic allometry. Morphological measurements with negative allometry were head length, head breadth, morphological total face length, total head height, biacrominal breadth hand length and foot length, while the other morphological measurements revealed isometry in both sexes. However, the values of the relative growth coefficient to anterior trunk length were larger in males than in females, except for in the case of biiliac breadth. These differences in growth patterns may cause the morphological differences between genders after sexual maturation in this primate species.

Age Factors↗
PubMed1993

[An autopsy case of brain candidiasis in premature infant: morphology and intraparenchymal distribution of Candida foci].

An autopsy case of brain candidiasis occurring in a premature infant is presented, and the morphology and intraparenchymal distribution of Candida foci are described in detail with the aid of serial sections of the affected brain. The patient was a boy, who was born after 25 weeks of gestation and died on day 15. Candida foci were composed of two infectious forms of Candida (yeasts and pseudohyphae) and various inflammatory reactions of the host. They were widely disseminated in the brain parenchyma, leptomeninges and ventricular system. In view of their morphology, they were classified into the acute and chronic inflammatory types. The acute type foci, characterized by microabscess of infiltration of neutrophils, were large and localized predominantly in the cerebral white matter, fiber tracts, central grey matter of the midbrain, reticular formation, floor of fourth ventricle and subependymal germinal layer; most of the acute type foci were found in the watershed zones where the blood supply was considered to be poorer than the other parts of the brain parenchyma. In contrast, the chronic type foci, characterized by nodular proliferation of astrocytes, were small and localized in the grey matter (the cerebral cortex, basal ganglia and brainstem nuclei) and the leptomeninges. This study suggests that Candida infection to the brain may occur by different two kinds of way correlating with the proper vasoarchitecture of brain. In addition, it is recommended to make a close examination of the maternal vagina, placenta and umbilical cord after delivery to detect the risk of Candida infection.

Brain↗
PubMed1992

Trace analysis of quinapril and its active metabolite, quinaprilat, in human plasma and urine by gas chromatography-negative-ion chemical ionization mass spectrometry.

A highly specific and sensitive method for the simultaneous determination of quinapril and its active metabolite, quinaprilat, in human plasma and urine by gas chromatography-negative-ion chemical ionization mass spectrometry is described. Quinapril and quinaprilat were extracted from human plasma and urine by using a Bond-Elut C18 cartridge. The plasma or urine extract was treated with pentafluorobenzyl bromide followed by trifluoroacetic anhydride to convert quinapril and quinaprilat into their pentafluorobenzyl-trifluoroacetyl derivatives, which were analysed by a selected-ion monitoring method using deuterium-labelled internal standards. The limits of quantitation for both quinapril and quinaprilat were 0.05 ng/ml in plasma and 0.5 ng/ml in urine. The proposed method is applicable to pharmacokinetic and clinical pharmacological studies with satisfactory reliability.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1992

Determination of dioxopiperazine metabolites of quinapril in biological fluids by gas chromatography-mass spectrometry.

The dioxopiperazine metabolites of quinapril in plasma and urine were extracted with hexane-dichloroethane (1:1) under acidic conditions. Following derivatization with pentafluorobenzyl bromide and purification of the desired reaction products using a column packed with silica gel, the metabolites were analysed separately by capillary column gas chromatography-electron-impact mass spectrometry with selected-ion monitoring. The limits of quantitation for the metabolites were 0.2 ng/ml in plasma and 1 ng/ml in urine. The limits of detection were 0.1 ng/ml in plasma and 0.5 ng/ml in urine, at a single-to-noise ratio of greater than 3 and greater than 5, respectively. The proposed method is applicable to pharmacokinetic studies.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1992

Development of the human pontine nuclei: a morphometric study.

The morphometric development of the pontine nuclei in the human fetus from 16 to 40 gestational weeks, in a 2-month-old infant and in a 63-year-old adult were examined employing a serial celloidin section method and computer assisted electronic planimeter. The results of our study can be summarized as follows: (1) the development of the human pontine nuclei accelerated in volume after 32 gestational weeks and continued after birth, (2) neuron numbers remained relatively constant after 27 gestational weeks. It was difficult to clearly distinguish neurons from glia before 27 gestational weeks. The total estimated neuronal numbers were not indicative of the gestational stages in infants 27 gestational weeks and older, (3) individual neurons appeared to continue to develop after 32 gestational weeks in accordance with size, distribution and circularity ratio, (4) many islet-shaped groups of large neurons appeared and were scattered throughout the pontine nuclei after 32 gestational weeks.

Cell Count↗
PubMed1992

Isolation of the avian transforming retrovirus, AS42, carrying the v-maf oncogene and initial characterization of its gene product.

A novel avian transforming retrovirus was isolated from a chicken musculoaponeurotic fibrosarcoma. This virus (called AS42) induces tumors histopathologically indistinguishable from the original sarcoma after a long latent period when inoculated into newborn chickens. AS42 also exhibits a weak transforming activity when infected into chicken embryo fibroblasts (CEF). This virus is replication-defective and associated with a helper virus of subgroup A (called ASAV). An AS42-specific protein of about 100 kDa was immunoprecipitated from lysates of AS42-transformed CEF with antiserum directed against avian retrovirus virion proteins. Molecular analysis of the genomic structure of the AS42 virus has revealed that this 100-kDa protein represents a novel oncogene, v-maf of cellular origin, which is fused with a part of the viral gag gene (Nishizawa et al., Proc. Natl. Acad. Sci. USA 86, 7711-7715, 1989). Interestingly, some size variation was observed among the gag-maf fusion proteins found in individual clones of transformed CEF. Consistent with this observation, Southern blot analyses and nucleotide sequence determination of several independent isolates of proviral DNA indicated that this virus segregates multiple forms of deletion mutants, probably through homologous recombinations among the repetitive sequences present within the v-maf coding region.

Animals↗
PubMed1992

Characterization of an exo-beta-D-fructosidase from Streptococcus mutans Ingbritt.

An extracellular enzyme beta-D-fructosidase was purified from the culture supernatant of Streptococcus mutans Ingbritt and characterized. The molecular weight of the enzyme was 127,000 as determined by SDS-polyacrylamide gel electrophoresis. The enzyme was specific for levan which mainly consists of beta-(2,6)-linked D-fructose and was also able to hydrolyze inulin, sucrose and raffinose at the activities of 13, 9 and 5% of that hydrolyzing levan, respectively. The pH optima for levan, inulin and sucrose were approximately 5.5, 6.0 and 5.0, respectively. The enzyme was optimally reactive at 55 C for levan. The enzyme was inhibited by Fe3+, Hg2+ and Zn2+ and not by either anionic or non-ionic detergents. Paper chromatographic analysis revealed that the enzyme attacked levan by an exo-type mechanism.

Chromatography, Gel↗
PubMed1992

Characterization of the dextranase purified from Streptococcus mutans Ingbritt.

We purified dextranase from the culture supernatant of Streptococcus mutans Ingbritt by procedures including ammonium sulfate precipitation, ion-exchange chromatography, and gel filtration. The molecular weight of the enzyme was estimated as 78 kDa by SDS-PAGE. The enzyme degraded dextran at the optimum pH of 5.5, but not other glucans and fructans at all. Paper chromatographic analysis revealed that the enzyme cleaved dextran by an endo-type mechanism. The enzyme was inhibited by Hg2+, Fe3+, Zn2+, and anionic detergents SDS and deoxycholic acid, but not inhibited by non-ionic detergents Triton X-100, Lubrol PX, Nonidet P-40, and Tween 80. SDS-blue dextran-PAGE analysis of the culture supernatant revealed that the enzyme activity detected in the 96 kDa band shifted gradually to the 78 kDa band during handling the supernatant. This shift was inhibited by phenylmethylsulfonyl fluoride, suggesting that the shift of the molecular size is due to proteolytic degradation of the enzyme by serine protease.

Detergents↗
PubMed1992

Effects of pulsing electromagnetic fields on the ligament healing in rabbits.

Effects of pulsing electromagnetic fields (PEMFs) on ligament healing were investigated using 80 rabbits. All animals received square resection (4 mm x 4 mm) of both patellar ligaments in full thickness at their center. They were divided into 4 groups of 20 rabbits each and stimulated with different electromagnetic intensity of 0 (control), 2, 10, and 50 gauss (G) for 6 hr daily. Pulse frequency and pulse width were 10 Hz and 25 microseconds, respectively. After PEMFs stimulations for 1, 2, 3 and 4 weeks, 5 animals of each group were euthanized and the regenerated tissue at the defective portion was investigated histologically and biomechanically. Histologically, the tissue stimulated by PEMFs showed an earlier increase in capillaries and fibroblasts and more matured, prominent longitudinal orientation of collagen fibers than those of control groups. Among the rabbits stimulated electromagnetically, those stimulated at 50 G revealed the earliest ligament healing. Tensile strength of regenerated ligament tissues of any PEMFs groups increased significantly at 1 and 2 weeks after operation, however, at 3 and 4 weeks after operation, there were no significant differences between groups. Among these values, those of 50 G group were the highest consistently during most of the experimental period. From the above results, PEMFs enhanced the earlier stage of ligament healings and 50 G gauss seemed to be the most effective among the 3 field intensities used. This promoting effect may potentiate the earlier recovery of the function after the ligament injury.

Animals↗
PubMed1992

Immunohistochemical analysis of constituents of senile plaques and cerebro-vascular amyloid in aged dogs.

Immunohistochemical analysis of constituents of senile plaques and cerebro-vascular amyloid in the brain of aged dogs was performed using antisera against beta protein, cystatin C, ubiquitin, tau, and neurofilament (NF). All types of senile plaques and cerebro-vascular amyloid in aged dogs were labeled by anti-beta protein serum. Cystatin C immunoreactivity was detected in neuronal cell bodies, primitive or classical plaques, and amyloid deposited around cerebral capillaries, but not in diffuse plaques and amyloid deposited in the media tunica of cerebro-meningeal arterioles. Ubiquitin-positive granules distributed widely in both gray and white matter of aged dogs, while they were very small in number in young dogs. Swollen neurites-like materials in primitive plaques or classical plaques were immunoreactive for anti-ubiquitin serum. Tau immunostaining labeled commonly axons and several neuronal or glial cells after hydrate autoclave pretreatment. Tau-positive components were observed very rarely in the corona of classical plaques. Most of swollen neurites-like structures of primitive or classical plaques were not reactive for anti-NF serum, and only a few plaques contained small numbers of NF-positive elements.

Aging↗
PubMed1992

Immunohistochemical studies on canine cerebral amyloid angiopathy and senile plaques.

Amyloid protein was isolated from the cerebral meninges of 4 aged dogs with cerebral amyloid angiopathy. By immunoblot analysis, antiserum against synthetic oligo-peptide consisting of 1-28 amino acid of amyloid beta protein recognized prominent wide band ranging from 14 to 18 kilodalton (kd). When amyloid samples were solubilized by formic acid, the antiserum recognized lower molecular weight band ranging from 3 to 4 kd. Immunohistochemical studies on cerebral amyloid angiopathy and senile plaques were performed in 17 aged dogs. Anti-amyloid beta protein serum labeled amyloid deposits in cerebral vessel walls and senile plaques. Compact deposits of beta protein were detected in primitive or classical plaques. After using formic acid pretreatment, diffuse deposits of beta protein in the neuropil representing diffuse plaques were detectable. Classical and primitive plaques reacted with antiserum against glial fibrillary acidic protein, while not with antisera against alpha 1-antichymotrypsin, IgG and IgM. Amyloid deposits in the intestines of aged dogs examined, did not react with anti-amyloid beta protein serum.

Aging↗
PubMed1992

Pathological studies on local tissue reactions in guinea pigs and rats caused by four different adjuvants.

We investigated pathological changes at the injection site in guinea pigs and rats for 16 weeks following a single intramuscular injection of one of the following oil adjuvant emulsions; oil adjuvant ISA-70, Freund's incomplete adjuvant, Freund's complete adjuvant, and aluminium phosphate gel. In the animals injected with ISA-70 emulsion prepared by manual shaking, grossly, there was partial thickening of subcutaneous tissue, discoloration of inter-muscular connective tissue, and swelling of the inguinal lymph nodes at 2 and 4 weeks post injection (PI). Histopathologically, ISA-70 injected sites revealed acute inflammatory changes at 72 hrs PI, and peak reactions consisting of macrophage accumulation around oil cysts and fibrosis were observed at 4 weeks PI. These changes were less severe and of shorter duration than those in the other three adjuvants. Guinea pigs and rats injected with materials containing inactivated Newcastle disease virus (NDV) antigen similarly showed an infiltration of plasma cells and lymphocytes in addition to the changes described above. ISA-70 containing NDV antigen induced similar hemagglutination-inhibition titer to that induced by Freund's incomplete adjuvant.

Adjuvants, Immunologic↗