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N Hashimoto

Publications and source records attributed to N Hashimoto.

At least 487 records · Page 27Linked to original sources
PubMed1991

Detection of burst-promoting activity in spleens of myeloproliferative sarcoma virus-infected mice using serum-free cultures.

Myeloproliferative syndrome was induced in adult DBA/2 mice by inoculation with myeloproliferative sarcoma virus (MPSV) and Friend murine leukemia virus (F-MuLV) as a helper virus. On day 26 after infection, the spleen weighed a maximum of 2.0 g (about 30 times the control weight). Assay of multipotent stem cells in vitro showed that the more enlarged spleens contained an increased number and concentration of mixed colony-forming units (CFU-mix) (at maximum, 11 times higher than the control). When the supernatant of cultured spleen cells was added to a serum-free bone marrow cell culture with or without erythropoietin (Epo) for detection of burst-promoting activity (BPA), it enhanced erythroid mixed colony (E-mix) formation only in the presence of Epo (p less than 0.05). Even when addition of Epo was delayed, it still induced a significant number of E-mix (p less than 0.05). These findings rule out a mimic effect of Epo resembling BPA and indicate the presence of BPA in the spleen. The culture supernatant also supported the proliferation of interleukin 3 (IL-3)-dependent 32Dcl cells. Therefore, although purification of the BPA substance has not yet been accomplished, BPA in the supernatant seems to depend on the presence of IL-3, which is known to be one of the factors stimulating multipotent hemopoietic stem cells. The presence of BPA- or CFU-mix-stimulating activity in the spleen after infection might be responsible for the development of panmyelosis, which is a characteristic of MPSV-induced myeloproliferative syndrome.

Animals↗
PubMed1991

Serological assessment of chlamydial infection in the koala by a slide EIA technique.

A rapid and simplified slide enzyme immunosorbent assay (EIA) was developed for the diagnosis of chlamydial infection in the koala. HeLa 229 cells infected with koala strain Chlamydia psittaci were fixed on the surface of multiwell slides and used as the antigen. The assay consisted of first reacting koala antiserum with the fixed C psittaci antigen, followed by reaction with biotinylated rabbit anti-koala IgG, ABC reagent and substrate. The chlamydial EIA antibody titres obtained were compared with those of a complement fixation (CF) test using koala strain C psittaci as antigen. Of 35 koala sera tested, 16 CF positive sera (greater than or equal to 1:8) also had a positive titre (greater than or equal to 1:200) in the slide EIA test (sensitivity 93.8%, 15/16). Nineteen CF negative sera were also negative in the slide EIA (specificity 100%, 19/19). Sixty-eight samples of koala blood were collected by ear-prick using a sampling paper method and were assayed by both tests. Sensitivity of the slide EIA was 100% (15/15) and specificity of the test was 96.2% (51/53). To simplify the slide EIA for use as a practical screening test, a 3-point serum dilution series (1:100, 1:200, 1:400) was used. This 3-point slide EIA was compared with the CF test using sheep strain chlamydial antigen. Thirty-nine sera were assayed by both tests. The sensitivity of the 3-point method was 85.7% (6/7) and the specificity was 71.9% (23/32) as compared with the sheep antigen CF test.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Kinetic studies on the appearance of antigens of Chlamydia psittaci during its developmental cycle.

The kinetics of the antigen production of Chlamydia psittaci strains Izawa-1 and Pigeon-1041 (P-1041) was examined every 6 hr after infection up to 48 hr, by the indirect immunofluorescent antibody technique using monoclonal antibodies (MAbs). All three genus-specific antigenic determinants on lipopolysaccharide (LPS) appeared during the whole growth cycle. Antigenic determinants on proteins were, on the other hand, detected at various time periods from the early to the late stages of infection. However, a cross-reactive antigenic determinant on protein recognized by a MAb 3E9 was also detected during the whole growth cycle, similar to that on LPS. The time of appearance of common antigenic determinants on proteins of Izawa-1 and P-1041 was examined using cross-reactive MAbs, and it varied depending on heterologous and homologous MAbs. From the relationship between the detection of antigenic determinants and the morphological changes of chlamydial particles revealed by electron microscopy during the growth cycle, the antigenic determinants on proteins of Chlamydia psittaci were divided into two groups; one was specific to the elementary body and the other was coexisting in both the elementary body and the reticulate body.

Animals↗
PubMed1991

Cerebral blood flow patterns at major vessel bifurcations and aneurysms in rats.

Cerebral arterial bifurcations in rats were treated to induce cerebral aneurysms experimentally, and flow patterns of latex particles introduced under a constant flow rate were analyzed with a 16-mm cine-camera and videocassette recorder. Cerebral aneurysms were produced by ligating one common carotid artery, inducing experimental hypertension, and feeding the animals beta-aminopropionitrile. After perfusion and fixation, samples of cerebral arterial bifurcations with shallow invaginations and with small aneurysms were obtained and used for analysis. Bifurcations in rats without experimental treatment were used as control specimens. Flow studies in the control bifurcations showed that the apical intimal pad, not the apex itself, acted as the flow divider. Small particles tended to accumulate at the region just distal to the apical intimal pad, where the initial aneurysmal changes are known to occur. This indicates stagnation of flow at that site. In the bifurcations with shallow invaginations and small aneurysms, a marked pressure gradient was present at the proximal end of the aneurysm orifice. A tendency for stagnation of small particles near the aneurysm wall was also observed. The wall shear stress was highest at the distal end of the aneurysmal orifice, which may be responsible for the development of these lesions.

Animals↗
PubMed1991

Susceptibility of laboratory and wild rodents to Rattus or Apodemus-type hantaviruses.

Adult Wistar rats (Rattus norvegicus), Apodemus agrarius, Meriones unguiculatus, Clethrionomys rufocanus, and Apodemus argenteus were inoculated with Rattus-type (SR-11, KI-262, and TB-314) or Apodemus-type (Hantaan 76-118) hantaviruses. Production of serum antibody to the inoculated virus (IAHA titres of 1:32 to 1:4 096) was obsersved in all rodent species 10 weeks after virus inoculation. Rattus-type virus was detected in some organs of all the rodent species employed except of Apodemus agrarius. Apodemus-type virus was found only in some organs of Apodemus agrarius. Newborn Wistar rats induced antibody in high titres to both Rattus- and Apodemus-type hantaviruses. Rattus-type virus was detected in all the organs examined for up to 6 weeks after inoculation, whereas Apodemus-type virus disappeared from all organs except of brain and lung tissues. The virulence of the three Rattus-type viruses to newborn rats was different. These findings indicate that the susceptibility of rodents may vary depending on the combination of rodent species and virus strains; they also suggest that the various species of rodents may be the reservoir animals of hantavirus infection in nature.

Animals↗
PubMed1991

Nucleotide sequence of a gene encoding a new genus specific protein of Chlamydia psittaci.

DNA fragment No. 13 from the C. psittaci pigeon strain, has been cloned in the plasmid pUC19. Hybridization analysis revealed that the fragment maintained a chlamydial common sequence. Furthermore, nucleotide sequencing identified two partial open reading frames (ORF), 675b. p. and 530b. p. Expression of ORFs revealed that the second ORF encoded 25KD polypeptide, whereas the first ORF did not produce any antigenic product. The 25KD beta-galactosidase fusion protein reacted strongly with chlamydia-specific antibodies elicited against a number of different chlamydial strains. Gene Bank analysis showed that this cloned gene is not highly homologous with chlamydia or other organisms for which nucleotide sequences have already been published. This 25KD polypeptide may be an additional genus-specific antigen of Chlamydiae.

Amino Acid Sequence↗
PubMed1991

Characterization of DNA fragment from Chlamydia psittaci avian strain which shows high homology with hypB gene of Chlamydia.

A study was performed to characterize DNA fragment No. 17 of C. psittaci strain P-1041 which encoded 42 KD beta-galactosidase fusion protein with type-specific antigenicity. Sequence determination identified a partial open reading frame that spanned about 1,200b. p. nucleotides. Screening the literatures for the nucleotide and deduced amino acid sequences revealed extensive similarity between the DNA fragment of P-1041 and two chlamydial hypB genes. This DNA showed 91.5% homology with C. psittaci GPIC hypB gene in nucleotide sequence and 96.4% homology in deduced amino acid sequence. The hypB gene of C. trachomatis serovar A and the P-1041 DNA fragment showed 81.2% and 91.3% homology in nucleotide and amino acid sequences, respectively. Dot enzyme-linked immunosorbent assay, for the products of deleted DNA fragments defined the coding region for type-specific antigenic polypeptide. In addition, the P-1041 DNA fragment carried a sequence highly homologous (greater than 49%) with other bacterial and plant genes called chaperonin which responds to various stress in cells. From these results, the P-1041 DNA fragment was found to be a part of hypB gene and to encode the region critical for type-specific antigenicity.

Amino Acid Sequence↗
PubMed1991

Accumulation of quinolinic acid in uremic serum and its removal by hemodialysis.

Quinolinic acid was first identified in uremic serum by use of gas chromatography/mass spectrometry. Quantification by selected ion monitoring revealed that the serum concentration of quinolinic acid was markedly increased in chronic hemodialysis patients, and that the acid could be removed by conventional hemodialysis. The serum concentration of quinolinic acid was weakly but significantly correlated with the serum uric acid concentration. Accumulation of quinolinic acid in uremic blood may be involved in the pathogenesis of anemia, suppressed immune system, and uremic encephalopathy.

Adult↗
PubMed1991

[A study of the determination of serum fucose concentrations].

We examined the biochemical properties of reaction products during the procedure for serum fucose determination (Dische & Shettles). The optical density at 396 nm (OD396) of the reaction products increased linearly with the increment of fucose concentrations, and was stable for at least 210-240 min at room temperature. The reaction products were destroyed with the addition of distilled water. Sephadex G-200 gel chromatography of the mixed serum samples revealed a single peak of fucose in the void volume fractions. Of interest was the presence of trace amounts of fucose detected in the low-molecular weight fractions less than 66,000, suggesting the presence of free fucose in the serum. Based on these observations, the method for serum fucose determination was modified so it was possible to use 100 microliters of the serum sample. The mean serum fucose concentration, measured by this modified method, was 561.0 +/- 191.1 mumol/l (9.1 +/- 3.1 mg/dl) in normal healthy children. In patients with idiopathic nephrotic syndrome, the values were significantly higher both at relapse and in remission than those in normal healthy children.

Chemical Fractionation↗
PubMed1991

Trolox protects rat hepatocytes against oxyradical damage and the ischemic rat liver from reperfusion injury.

Trolox, a hydrophilic analog of vitamin E, was reported to scavenge peroxyl radicals from artificial systems better than its parent compound. Here we examined the possible cytoprotective effect of Trolox in cultured hepatocytes and in the rat liver. In cultured rat hepatocytes, 0.5 to 16 mmol/L Trolox (with optimum between 1 to 2 mmol/L) was observed to prolong the survival of cells exposed to oxyradicals generated with xanthine oxidase-hypoxanthine. The protection by 1 mmol/L Trolox surpassed that provided by either ascorbate, mannitol, superoxide dismutase and/or catalase--each at a level giving its maximal protection in the same system. In both a global and partial model of hepatic ischemia-reperfusion in rats, infusion of Trolox (7.5 to 10 mumol/kg body weight) just before reflow reduced by greater than 80% the liver necrosis sustained in untreated (no Trolox) control rats. Such organ salvage was apparently accompanied by approximately 50% reduction in the amount of hepatic conjugated dienes, which were quantified by a highly specific radiochemical assay. Since conjugated dienes are presumed to be good "markers" of oxyradical damage, our data may have provided a semiquantitative link between free radical-induced necrosis and its chemical imprint in vivo. The data also indicated a relatively rapid and potent antioxidant-like action by Trolox on rat hepatocytes and on the postischemic reperfused rat liver.

Animals↗
PubMed1990

Insulin-resistant diabetes associated with partial deletion of insulin-receptor gene.

The insulin-receptor genes from a 16-year-old girl with type A insulin resistance, who presented with fasting hyperinsulinaemia, acanthosis nigricans, and reduced insulin binding, and from her family were examined. One allele of her insulin-receptor gene inherited from her mother contained a 1.2 kb deletion arising from a recombination between two Alu elements. The deletion removed the 14th exon in the beta subunit and altered the reading frame, to produce a stop codon after aminoacid 867. Pedigree analysis indicated that this mutation alone will not cause diabetes, and the proband is possibly a compound heterozygote. 4 other members of her family were heterozygous for the same mutation; all 4 had a decrease in insulin binding and slight impairment of glucose tolerance. Perhaps the same mutation is an underlying feature of some cases of non-insulin-dependent diabetes mellitus.

Adolescent↗
PubMed1990

Germ cell deficiency causes testis cord differentiation in reconstituted mouse fetal ovaries.

Sex-reversal in fetal ovaries was studied by using a dissociation-reconstitution technique. Gonads of 12.5 gestation-day male and female mouse fetuses were dissociated into single cells. To eliminate germ cells, the dissociated cells were cultured for 14 h, and then somatic cells attached to culture dishes were harvested and aggregated by gyratory culture for 24 h. The aggregates were then transplanted into ovarian bursa in ovary-ectomized nude mice. The recovered explants were examined histologically. Male somatic cells developed into testes containing Sertoli cells, Leidig cells, and tunica albuginea. Female somatic cells formed testis cords and differentiated into Sertoli cells, but they did not differentiate into other testis components or ovarian tissues. However, aggregates consisting of both female and male somatic cells differentiated into well-developed testes containing Leidig cells and tunica albuginea as well as Sertoli cells. Enzyme marker analysis showed significant contributions of female cells in these organized testes. In contrast, aggregates containing both female germ cells and somatic cells developed into ovaries and did not differentiate into any testicular tissues. The results indicate that female somatic cells in fetal gonads at 12.5 gestation day have the potency to form testis cords and differentiate into Sertoli cells. The subsequent steps in testis development require the contributions of male cells. The present study also suggests that testicular differentiation is independent of germ cells but ovarian development involves the interaction between germ cells and somatic cells.

Animals↗
PubMed1990

Hepatobiliary and gastrointestinal imaging after pancreaticoduodenectomy--a comparative study on Billroth I and Billroth II reconstructions.

This study was conducted to compare the passage of bile and food through the remnant alimentary tract between 2 and 6 months following pancreaticoduodenectomy in patients undergoing Billroth I (Imanaga) and Billroth II (Child) reconstructions, using dual scintigraphy. In the patients who underwent Child's operation (n = 14), hepatobiliary scintigraphy showed a prominent stasis of bile tracer in the proximal jejunal loop and a significant time delay before the bile and food became mixed at the upper jejunum. On the other hand, in the patients who underwent Imanaga's operation (n = 9) no bile stasis in the proximal jejunal loop was found and the time taken before the two agents became mixed was similar to that of healthy controls (n = 7). The time taken for the two agents to mix at the upper jejunum was 65.8 +/- 7.9 min in the patients after Child's operation, 17.3 +/- 2.5 min in those after Imanaga's operation, and 18.5 +/- 2.8 min in the healthy controls, respectively. Continuous stasis of bile in the proximal loop and severe postcibal asynchronism in patients who undergo Child's operation can therefore cause reflux cholangitis and absorptive disturbances in the long postoperative term. The results of this study suggest that Imanaga's reconstruction is a more physiological procedure than Child's reconstruction following pancreaticoduodenectomy.

Anastomosis, Surgical↗
PubMed1990

A multi-center double-blind controlled trial of ursodeoxycholic acid for primary biliary cirrhosis.

A multi-center double-blind controlled trial of ursodeoxycholic acid (UDCA) for treatment of primary biliary cirrhosis (PBC) was carried out. Twenty two and 23 patients were treated with 600 mg/day UDCA and placebo, respectively, for 24 weeks. In UDCA-treated patients, fall of serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and gamma-glutamyltranspeptidase activities started within 4 weeks after start of the trial and continued throughout the trial period. The serum IgM level fell in 7 UDCA-treated patients examined but not in 10 placebo-treated patients examined. Serum bilirubin concentration showed no significant change at the end of the study in either of UDCA- and placebo-treated group of patients. There was no significant difference between these two groups with respect to the frequency of improvement of pruritus. In UDCA-treated patients, serum bile acid composition changed markedly, though its concentration showed no significant change. The percentage of total bile acid which ursodeoxycholic acid took up increased, whereas those which cholic acid, chenodeoxycholic acid and deoxycholic acid took up were decreased.

Alanine Transaminase↗
PubMed1990

Elevation of serum type IV collagen-degrading enzyme in hepatocellular carcinoma with metastasis.

The activity of serum type IV collagen-degrading enzyme was measured in 21 patients with hepatocellular carcinoma, and the changes in the enzyme activity were investigated with respect to metastasis. The activity of serum type IV collagen-degrading enzyme did not increase until tumor invasion to the portal vein and intrahepatic metastasis were clearly detected ultrasonographically. Activities did not increase during the observation period in patients whose tumor grew slowly and did not invade the portal vein. Thus, the enzyme activity increases in relation to the metastasis of hepatocellular carcinoma and may be useful to detect ongoing metastases.

Aged↗
PubMed1990

Malignant Sertoli and Leydig cell tumour in a boar.

A rare case of Sertoli and Leydig cell tumour was investigated in a 6-month-old boar. The neoplasm was found in the right testis and had metastasized to the liver, spleen, kidneys and diaphragmatic peritoneum. Metastatic nodules were also present in the tissues near the right testis and some neoplastic cells were present in the superficial inguinal lymph node. The neoplastic cells exhibiting severe pleomorphism were divided into Sertoli and Leydig cell types, although in some sites, it was not possible to classify tumour cells clearly as Sertoli or Leydig in type. In the metastatic lesions there were anaplastic Sertoli cells with abundant collagen fibres. Some neoplastic Sertoli cells and a few neoplastic Leydig cells revealed cytoplasmic reactivity for testosterone. Ultrastructurally, the neoplastic cells were characterized by mitochondria with tubulovesicular cristae, smooth endoplasmic reticulum, membranous structures, lysosomes, lipofuscin granules or lipid droplets.

Animals↗