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Biomedical subjects

H Yoshikawa

Publications and source records attributed to H Yoshikawa.

At least 19 recordsLinked to original sources
PubMed1992

Relationship of age at menarche and subsequent fertility.

We investigated retrospectively the relationship between the age at menarche and reproductive ability in 2278 married women. Those who had a pregnancy experienced menarche at a mean age (+/- SEM) of 13.7 +/- 0.1 years, and those who were infertile had menarche at a mean age of 14.0 +/- 0.2 years, difference in the times of onset of menarche being significant (P less than 0.05). Moreover, a group in whom menstruation started after the age of 18 years had a significantly higher rate of infertility (15.7%) than the others (5.0%). Irregular menstruations during the first few years after menarche was also related to decreased reproductive ability. These findings indicate the importance of menarche before the age of 18 for normal reproductive functioning.

Adolescent↗
PubMed1992

The medial dorsal nucleus is one of the thalamic relays of the cerebellocerebral responses to the frontal association cortex in the monkey: horseradish peroxidase and fluorescent dye double staining study.

To reveal the thalamic relay nucleus of the cerebellocerebral responses in the frontal association cortex, simultaneous labeling of the cerebellothalamic (C-T) terminals and the thalamocortical (T-Cx) neurons was performed in three monkeys. Horseradish peroxidase (HRP) was injected into the deep cerebellar nuclei and small doses of HRP or fluorescent dye were injected into the prefrontal cortex. The distribution of anterogradely labeled C-T terminals and retrogradely labeled T-Cx neurons was examined in the same sections. In addition to being distributed in the ventral thalamic nuclei and nucleus X, as previously reported, anterogradely labeled terminals were distributed in the ventrolateral part of the medial dorsal (MD) nucleus where retrogradely labeled thalamo-frontal projection neurons were localized. This study revealed that the ventrolateral parts of the MD together (MDmf, MDpc and MDdc) form one of the thalamic relays of the cerebelloprefrontal responses.

Animals↗
PubMed1992

IFN-gamma-producing ability as a possible marker for the protective T cells against Mycobacterium bovis BCG in mice.

We searched for a functional marker with which T cells mediating acquired cellular resistance (ACR) can be discriminated from those mediating delayed-type hypersensitivity (DTH) in mice immunized with Mycobacterium bovis BCG. Four wk after injection of the mice with 10(5) viable BCG (vBCG) cells emulsified in IFA, a passive transfer experiment revealed that T cells mediating DTH as well as ACR, which we designated TACR, were generated in the spleen. In contrast, T cells mediating only DTH (TDTH) were generated by immunization with 10(7) killed BCG cells along with IFA. The transferring ability of both TACR and TDTH was substantially reduced by treatment with anti-Thy-1.2 or anti-CD4 mAb plus complement, whereas anti-CD8 treatment had no effect. To determine the functional differences between TACR and TDTH, we assessed IL-2 and IFN-gamma production from TACR and TDTH after stimulation with PPD in vitro. Similar levels of enhanced IL-2 activity were detected in the culture supernatants of both groups of T cells. However, augmented production of IFN-gamma was observed only in TACR. This finding was confirmed by Northern blot analysis for detection of IFN-gamma-specific mRNA. In addition, a significant increase in the number of IFN-gamma-producing cells was observed only in T cells from mice immunized with vBCG. The production of IFN-gamma was also totally abolished by treatment with anti-Thy-1.2 and anti-CD4 mAb plus complement in vitro, whereas anti-CD8 mAb treatment had no effect. These results suggest that CD4+ protective T cells generated by immunization with vBCG are characterized by the ability to produce IFN-gamma after stimulation with specific Ag.

Animals↗
PubMed1992

Structure of the dnaA and DnaA-box region in the Mycoplasma capricolum chromosome: conservation and variations in the course of evolution.

We have previously shown that the dnaA gene and the DnaA-box region were conserved in bacteria representative of all three major branches of the eubacterial phylogenic tree: high G + C Gram+, low-G + C Gram+ and Gram-. In the present work, we determined the structure of the dnaA region of Mycoplasma capricolum and found that the dnaA gene and at least two other genes, rpmH and dnaN, were conserved in this bacterium. An unusually high level of amino acid (aa) substitutions was observed in M. capricolum DnaA. It was the case even in those aa which were well conserved in other bacterial species. The nontranslatable region upstream from the dnaA gene was also conserved in this bacterium, as it was universally found in both Gram+ and Gram- bacteria. An additional nontranslatable region downstream from the dnaA gene, which is common to Gram+ bacteria, was also found in M. capricolum, consistent with the proposal that M. capricolum is Gram+ in origin. These regions were rich in A + T and contained ten DnaA-box-like sequences (9-mers that differ from TTATCCACA by one or two bases).

Amino Acid Sequence↗
PubMed1992

Alumina ceramic prostheses for bone tumor surgery.

Between 1979 and 1990 reconstruction using a ceramic prosthesis with a polycrystal alumina segment and a monocrystal alumina stem was carried out in 65 patients after the resection of malignant or benign aggressive bone tumors. Resection of 18 osteosarcomas, 5 chondrosarcomas, 9 other sarcomas, 10 giant cell tumors, 20 metastatic bone tumors, and 3 other bone tumors was followed by replacement of 17 proximal femurs, 12 distal femurs, 12 proximal tibia, 11 proximal humeri, 3 distal radii, 5 midshafts of the long bone, 2 pelvises, and 3 other parts. Results were rated excellent in 4 cases, good in 43, fair in 13, and poor in 4. In the cases with benignly aggressive or low-grade malignant tumors and those with tumors of the proximal femur, proximal tibia, or midshaft, satisfactory results can be obtained. Four skin ulcers, three dislocations, three loosenings, two infections, and two breaks were noted. Close interfacing between the ceramic prosthesis and the bone was observed radiologically in all cases with cementless fixation except in cases with high-grade malignancies in the knee joint. These results demonstrate that the ceramic prosthesis can be beneficial for the management of patients with benignly aggressive or low-grade malignant bone tumors who have retained adequate muscle strength around the joint even after tumor resection.

Adolescent↗
PubMed1992

Tay-Sachs disease: progression of changes on neuroimaging in four cases.

The neuroradiological findings in four patients with Tay-Sachs disease are described in three phases of the clinical course. The basal ganglia and cerebral white matter show low density on computed tomography and high signal intensity on T2-weighted magnetic resonance imaging in the initial phase. The caudate nuclei are characteristically enlarged and protrude into the lateral ventricles in the first and second phases. The cerebral white matter shows low density on the CT which varies in extent from the second to third phases, and the whole brain becomes atrophic in the last phase. Thus, central nervous system involvement in the disease may begin in basal ganglia as well as in cerebral white matter.

Atrophy↗
PubMed1992

Pathology of chemically induced chronic active hepatitis in mice.

Female Swiss mice were treated for 24 weeks, with 3-hydroxy-4-pyrone (Py) added to their powdered diet at 0.5% (wt/wt), and the effects of this agent on the liver were examined. Serum transaminases (especially GPT) rose continuously, while the GOT/GPT ratio remained at approximately 1.0 throughout the study period. The characteristic changes found from 8 weeks onward were piecemeal necrosis and bridging necrosis of the hepatocytes with dense lymphocytic infiltration. Proliferation of collagen fibers in the portal tracts and formation of narrow fibrous septa dividing the lobules into pseudolobules were also noted from 12 weeks onward. A large number of the infiltrating lymphocytes were identified as T cells by immunohistochemical and electron microscopic studies. These lymphocytes often surrounded or were closely attached to degenerating hepatocytes. Focal apoptosis and necrosis accompanied by a granulomatous reaction of the centrilobular hepatocytes were noted as early changes in the liver. Our findings indicate that the hepatic changes produced in mice by long-term Py administration have characteristics in common with those of human chronic active hepatitis. Immunological cytotoxic mechanisms, especially T cell-mediated ones, appear to play an essential role in the development of hepatic lesions in this murine model of chronic active hepatitis.

Alanine Transaminase↗
PubMed1992

Morphological features of cat thalamo-parietal projection fibers investigated by PHA-L immunohistochemistry and electron microscopy.

Thalamo-parietal fibers originating from the ventroanterior-ventrolateral (VA-VL) complex in the cat were labeled with Phaseolus vulgaris leucoagglutinin (PHA-L) and examined by light and electron microscopy. PHA-L (2.5% aqueous solution) was injected iontophoretically through micropipets with anodal current pulses into the VA-VL complex. PHA-L-labeled terminals were distributed in the lateral and the suprasylvian gyri in the superficial and deep cortical layers. In layer I, horizontal varicose fibers and terminals were conspicuous in the upper one-third and were widely distributed. In the deeper cortical layers (layers III-V), varicose fibers and terminals were detected in moderate numbers. Electron microscopic examination revealed that the labeled terminals formed asymmetrical synapses on the dendritic spines of spiny neurons. These morphological findings appeared to be consistent with our previous intracellular recordings in this cortex.

Animals↗
PubMed1992

Amniotic tissue transplantation: clinical and biochemical evaluations for some lysosomal storage diseases.

Amniotic epithelial cells has been used for transplantation in patients with lysosomal storage diseases as an enzyme replacement therapy. But its clinical effect is still the question under debate. We performed amniotic tissue transplantation on patients with different lysosomal storage diseases: one with Tay-Sachs disease, one with juvenile Gaucher disease and one with juvenile metachromatic leukodystrophy. The patient having juvenile Gaucher disease received this grafting twice. Objective clinical improvement was observed in the first trial where this patient showed an increase of soluble beta-glucosidase one week after implantation. No clinical or biochemical changes were seen in the other patients. Although there are some advantages to amniotic tissue transplantation, original methods should be modified to cell transplantation in order to avoid graft-versus-host reaction which could happen in repeated implantation.

Adolescent↗
PubMed1992

Molecular weight-dependent lymphatic transfer of exogenous macromolecules from large intestine of renal insufficiency rats.

To study the lymphatic delivery of exogenous macromolecules via the enteral route in renal insufficiency, we determined the transfer selectivity to the systemic blood and lymph of fluorescein isothiocyanate-labeled dextrans of different average molecular weight (10, 18, 39, and 69kD). The compounds were administered into the large intestinal lumen of rats with occluded renal circulation, with the aid of lipid-surfactant mixed micelles as an absorption prometer. Whereas concentrations of the smaller dextrans (molecular weight under 18 kD) in the lymph of the thoracic duct and in the peripheral plasma were similar, levels of dextrans over 39 kD were significantly higher in the lymph than in the plasma. Further, dextran plasma concentrations decreased in inverse proportion to increasing molecular weight. The molecular weight threshold for a high lymph-to-blood level ratio (18-39 kD) was higher than that previously found in rats with normal renal function (10-18 kD). This difference was accounted for by reduced renal clearance of the low molecular weight dextrans in renal failure. These results are useful in the design of lymphotropic drug delivery in disease states.

Animals↗
PubMed1992

Intraarterial infusion chemotherapy with [Sar1,Ile8]angiotensin II for bladder cancer.

Thirty-three patients with primary bladder cancer (nine stage T1 with multifocal tumors and 24 stage T2-4) were treated with intraarterial infusion chemotherapy including cisplatin, doxorubicin, and [Sar1,Ile8]Angiotensin II(AT II). Of the 32 evaluable patients, 12 had pathologically proven complete response (CR), 19 showed partial response (PR), and one showed no change (NC); the overall response rate (CR + PR) was 97%. The blood pressure increased in response to the administration of [Sar1,Ile8]AT II in all the patients; the mean increase in the systolic blood pressure was 36 mmHg. Most of the side effects were mild to moderate in severity, transient in nature, and included nausea/vomiting (100%), alopecia (84%), leukopenia (66%), headache (9%), nephrotoxicity (6%), diarrhea (3%), skin pigmentation (3%), and neurotoxicity (3%). One patient who dropped out of the study developed hemiplegia as a result of cerebral infarction. The findings indicate that it is necessary to exercise caution in selecting the patients to be subjected to this therapy. We conclude that intraarterial infusion chemotherapy combined with a vasoconstrictor has a significant effect not only against multifocal superficial bladder cancer but also against invasive bladder cancer.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1992

Pharyngoconjunctival fever caused by adenovirus type 11.

Among a group of hospitalized children in Fukuoka, southern Japan, an epidemic of pharyngoconjunctival fever-like disease caused by adenovirus type 11 was observed in the autumn of 1988. Of the 47 children studied 38 were seronegative in neutralizing antibody for adenovirus type 11 before the epidemic, and seroconversion occurred in 16 (42%) including 5 subclinical cases. Of the 11 symptomatic patients the incidences of conjunctivitis, pharyngitis and fever were 91, 64 and 46%, respectively. Four patients (36%) had all three symptoms. Fifteen patients (94%) were boys. The sex predominance and high incidence of conjunctivitis suggested that infection may have been transmitted in the large bathroom where boys took baths together.

Adenovirus Infections, Human↗
PubMed1992

Short sequence in L1 region of human papillomaviruses correlates with clinical pictures and grouping by cross-hybridization.

A consensus primer-mediated polymerase chain reaction devised to amplify a short sequence in L1 region (L1-PCR) efficiently detected genital human papillomaviruses (HPVs) in clinical materials. Nucleotide sequencing of the amplified fragment showed that L1-PCR is also applicable to hitherto unsequenced HPVs. By comparing the amplified 210 nucleotides HPVs were classified into six groups, which are consistent with clinical pictures and a grouping based on cross-hybridization under the stringent condition.

Base Sequence↗
PubMed1992

Cloning of an autonomously replicating sequence (ars) from the Bacillus subtilis chromosome.

Cloning of an autonomously replicating sequence (ars) from the origin region of Bacillus subtilis was previously unsuccessful because of the strong incompatibility exerted by sequences located within the oriC region. Using an ars searching vector which would be selective for drug resistance even at one copy per cell, and by cloning large fragments covering as much as possible of the oriC region, we have succeeded in isolating ars fragments from the origin region of the chromosome. The minimum essential fragment contains two DnaA-box regions (non-translatable regions containing multiple repeats of DnaA-box) separated by the dnaA gene. Neither one of the DnaA-box regions by itself showed ars activity. When constructed as oriC plasmids, the dnaA coding region could be removed without affecting ars activity. The minimum distance between the two DnaA-box regions obtained so far is 274 bp. The copy number of the oriC plasmid is estimated as one per replicating chromosome. These plasmids are unstable and tend to be lost or integrated into chromosome.

Amino Acid Sequence↗
PubMed1992

Genes and their organization in the replication origin region of the bacterial chromosome.

Genes and their organization are conserved in the replication origin region of the bacterial chromosome. To determine the extent of the conserved region in Gram-positive and Gram-negative bacteria, which diverged 1.2 billion years ago, we have further sequenced the region upstream from the dnaA genes in Bacillus subtilis and Pseudomonas putida. Fifteen open reading frames (ORFs) and 11 ORFs were identified in the 13.6 kb and the 9.8 kb fragments in B. subtilis and P. putida, respectively. Eight consecutive P. putida genes, except for one small ORF (homologous to gene 9K of Escherichia coli) in between, are homologous in sequence and relative locations to genes in B. subtilis. Altogether, 12 genes and their organization are conserved in B. subtilis and P. putida in the origin region. We found that the conserved region terminated on one side after the orf290 in P. putida (orf282 in B. subtilis). In the B. subtilis chromosome, five additional ORFs were found in between the conserved genes, suggesting that they are added after Gram-positive bacteria were diverged from the Gram-negative bacteria. One of the ORFs is a duplicate of the conserved gene. The third non-translatable region containing multiple repeats of DnaA-box (second in the case of P. putida) was found flanking gidA in both organisms. This result shows clearly that E. coli oriC and flanking genes gidA and gidB have been translocated by the inversion of some 40 kb fragment.

Amino Acid Sequence↗