Biomedical subjects

M Yoshida

Publications and source records attributed to M Yoshida.

At least 973 records · Page 54Linked to original sources

PubMed1997

Thrombopoietin-independent effect of interferon-gamma on the proliferation of human megakaryocyte progenitors.

Flow cytometric study revealed that almost all CD34+ cells in human umbilical cord blood expressed interferon-gamma receptor (IFN-gammaR). To clarify the precise functional roles of IFN-gammaR in human CD34+ cells, we examined the effect of IFN-gamma alone and in combination with various cytokines on the growth of haemopoietic progenitor cells in CD34+ cells using a serum-free clonal culture. Surprisingly, IFN-gamma alone supported only megakaryocyte (MK) colonies in a dose-dependent manner with a plateau level at 1000 U/ml of IFN-gamma. IFN-gamma at 1000 U/ml induced 10 +/- 1.2 MK colonies from 1 x 10(3) CD34+ cells, whereas thrombopoietin (TPO), interleukin (IL)-3, stem cell factor (SCF) or IL-6 alone induced 22 +/- 4.0, 22 +/- 4.2, 4 +/- 0.6 and 0 MK colonies, respectively. The addition of anti-IFN-gamma monoclonal antibody (mAb) to the IFN-gamma culture completely abrogated MK colony formation, whereas the mAb had no effect on TPO-dependent production of MK colonies. In contrast, although anti-TPO polyclonal Ab almost completely blocked TPO-dependent MK colony formation, it failed to inhibit the generation of MK colonies induced by IFN-gamma, suggesting that the observed effect of IFN-gamma on the proliferation of human MK progenitor cells is independent of TPO. The addition of IFN-gamma to culture with TPO or SCF significantly augmented the development of MK colonies, whereas it did not affect IL-3-dependent MK colony formation. Additionally, IFN-gamma induced the increase of DNA content of cultured glycoprotein IIb/IIIa-positive megakaryocytes. These results suggest that IFN-gamma may have regulatory roles in human megakaryocytopoiesis.

Antibodies, Monoclonal↗

PubMed1997

Novel autoantigens of perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCA) in ulcerative colitis: non-histone chromosomal proteins, HMG1 and HMG2.

Anti-neutrophil cytoplasmic antibodies (ANCA) in sera from ulcerative colitis (UC) patients have been described as reacting with proteins in the granules of human neutrophils such as cathepsin G and lactoferrin and with yet unidentified antigens. Here we report the existence of a new member of perinuclear ANCA (P-ANCA) in UC patients. In the previous study, we found that UC patients had a novel P-ANCA against neutrophil 28-kD protein. In this study, we purified the same antigens from HL-60 lysates by using reversed phase high-performance liquid chromatography, and revealed that the 28-kD antigen consisted of two different proteins. The N-terminus amino acids of these proteins are identical with those of high mobility group (HMG) non-histone chromosomal proteins HMG1 and HMG2. Immunoblotting analysis of human neutrophil lysates using rabbit anti-HMG1/2 antisera revealed a single band of 28 kD, and the 28-kD band detected by immunoblotting analysis using patient's serum IgG completely disappeared after preincubation with a mixture of HMG1 and HMG2. Furthermore, rabbit anti-HMG1/2 antisera showed a perinuclear staining pattern in indirect immunofluorescence studies using ethanol-fixed neutrophils. These data demonstrate that HMG1 and HMG2 are novel target antigens of P-ANCA. HMGI and HMG2 are distributed in the nuclei and cytoplasm of eukaryotic cells and act as transcription factors. Their intracellular localization and functions are distinct from those of the previously reported granular antigens of P-ANCA.

Amino Acid Sequence↗

PubMed1997

Expression of neurotrophic factors in cultured human retinal pigment epithelial cells.

PURPOSE: To see if cultured human retinal pigment epithelial (RPE) cells have the capacity to synthesize neurotrophins, including nerve growth factor (NGF), brain-derived growth factor (BDNF), and neurotrophin-3 (NT-3). METHODS: Expression of mRNAs for the neurotrophins was studied by the reverse transcription polymerase chain reaction (PCR) method. Quantitative analysis of the gene expression was done by using a semiquantitative PCR method. Secretion of NGF-like immunoreactivity (NGF-LI) into the culture medium was analyzed by enzyme immunoassay (EIA). RESULTS: Cultured human RPE cells were found to express mRNAs for NGF, BDNF and NT-3. In the conditioned culture medium of the human RPE, 9.44 +/- 0.62 pg/ml (mean +/- SEM, n = 6) NGF-LI was found. Pretreatment of human RPE cells with interleukin-l (IL-1) (20 ng/ml), phorbol myristate acetate (PMA) (100 ng/ml) or tumor necrosis factor-alpha (TNF-alpha) (40 ng/ml) was found to increase the mRNA expression of neurotrophins and also to increase secretion of NGF-LI into the culture medium. CONCLUSIONS: Our data demonstrate that cultured human RPE cells have the capacity to synthesize neurotrophins, and that various stimulations can up-regulate gene and protein expression of NGF by these cells.

Brain-Derived Neurotrophic Factor↗

PubMed1997

Difference in affinity for DNA between HMG proteins 1 and 2 determined by surface plasmon resonance measurements.

High mobility group (HMG) proteins 1 and 2 contain two similar but non-identical repeats of DNA-binding domains and an acidic C-terminal. The proposed functions of HMG proteins 1 and 2 imply a probable difference in their DNA-binding abilities. The primary studies by gel retardation assay showed that HMG2 has higher affinity than HMG1 for supercoiled and linear DNA. The DNA-binding of HMG2 appeared strong enough to allow exchange with HMG1 molecule already bound to DNA, while the DNA-binding region of HMG1 showed higher affinity than that of HMG2. In order to compare more quantitatively the affinities, surface plasmon resonance (SPR) measurements using a BIAcore instrument were conducted. The kinetic data indicated that the Kd for the complex of HMG2 with DNA is smaller than that of HMG1, in contrast to the situation for the DNA-binding region of these proteins. The sequence between the second DNA-binding domain and the acidic C-terminal of HMG proteins is required for tight DNA-binding. Also, the acidic C-terminal strongly modulates the DNA-binding ability of each protein. The usefulness of SPR measurement for quantitative analysis of affinity and regions involved in DNA-binding under conditions nearly identical to those in solution is discussed.

Animals↗

PubMed1997

Alterations of lactate (+lipid) concentration in brain tumors with in vivo hydrogen magnetic resonance spectroscopy during radiotherapy.

RATIONALE AND OBJECTIVES: The authors determine whether assessment of the relative lactate(+lipid) concentration ([r-Lac(+lip)]) obtained from hydrogen magnetic resonance (MR) spectroscopy is useful for predicting the outcome of radiotherapy on brain tumors. METHODS: Fifty-one hydrogen MR spectroscopic studies were performed in eight patients with primary or metastatic brain tumor before and during radiotherapy. The r-Lac(+lip) calculated as the ratio of lactate(+lipid) peak area to total water was compared before and during radiotherapy in each case. The change of tumor volume measured on magnetic resonance images also was compared. RESULTS: The r-Lac(+lip) substantially decreased in the radiosensitive cases (three lymphomas and one brain cancer) but did not decrease, even at the end of therapy, in the radioresistant cases (two brain cancers and two glioblastomas). CONCLUSION: Assessment of r-Lac(+lip) may adjunctively contribute to the early prediction of the radiotherapeutic effect on brain tumors.

Adult↗

PubMed1997

Suppressed production of nitric oxide as a cause of irregular constriction of gastric venules induced by thermal injury in rats.

Microcirculatory disturbance is a crucial step in development of gastric mucosal lesions. In this study we investigated the influence of nitric oxide (NO) on the irregular constriction of gastric venules observed in rats subjected to thermal injury. Male Wistar rats were anesthetized and a 30% full skin thickness dorsal burn was inflicted. Microvascular images in the submucosal layer and basal region of the gastric mucosa were obtained through an intravital microscope. Distribution of constitutive-type nitric oxide synthase (cNOS) was observed by the immunofluorescence method. Venule walls were basically smooth in the control group (no injury), whereas irregular constrictions tended to be observed in the 5-h group (5 h after thermal injury). Venule diameter was significantly smaller in the 5-h group. In the control group, cNOS-associated fluorescence was found on the venule endothelium, whereas it was almost negligible after thermal injury. A NO donor, 3-morpholinosydnonimine hydrochloride, simultaneously diminished the thermal injury-associated venule constriction and irregularity of venule walls. Therefore, the present study suggests that venule constriction, which is observed 5 h after thermal injury, is related to decreased NO production by endothelial cNOS and is a cause of irregularity of the venule walls.

Animals↗

PubMed1997

Transmission of human herpesvirus 7 through multigenerational families in the same household.

BACKGROUND: Human herpesvirus 7 (HHV-7) closely resembles HHV-6 and to a lesser degree cytomegalovirus. HHV-7 infection is usually acquired during early childhood. Primary infection can cause a roseola-like illness but in most cases it is only mildly symptomatic. The majority of adults are seropositive and in contrast to HHV-6 and cytomegalovirus infection, they continue to secrete the virus in their saliva for many years. The mode of intrafamilial transmission of this virus is not well-understood. METHODS: Saliva samples for virus isolation and DNA restriction analysis were obtained from all 47 members of 6 Japanese families, including 4 families with 3 generations living in the same household. RESULTS: HHV-7 was isolated from 43 of 47 saliva samples collected from children and adult members of the 6 families (91.5%). In one family the restriction patterns of the maternal grandmother, the mother and the children were similar, and the patterns of the paternal grandmother and the father were similar. In another family the patterns of the father and 5 of 6 children were similar, and those of the mother and the other child were similar. Altogether similar HHV-7 restriction profiles with his or her mother were found in 48% of offspring, and similar profiles with his or her father were found in 28% of offspring. CONCLUSIONS: The results strongly suggested horizontal transmission of HHV-7 from grandparents to parents to children through close contact within a household. Either parent could transmit HHV-7 to the children.

Adolescent↗

PubMed1997

In vitro selection of variants of herpes simplex virus type 1 which differ in cytopathic changes.

To analyze the mechanisms for in vitro emergence of the syncytial variants of herpes simplex virus type 1 (HSV-1), several cell lines were infected with a mixture of equal amounts of two HSV-1 variants, one syncytial and the other non-syncytial, and changes in their relative abundance were monitored during passage. With a combination of two variants of the Miyama strain of HSV-1, the syncytial variant became dominant during passage in Vero, RK-13 and FL cells. On the other hand, the ratios of the two variants remained around 1:1 during the passage in HEp-2, MGC and HEL cells. In another set of variants of the SKO strain of HSV-1, the outcomes were different from those of the Miyama strain in the FL, MGC and HEp-2 cells. The ratios of the two variants remained around 1:1 during passage in FL cells, while the non-syncytial variant became dominant during passage in MGC and HEp-2 cells. In addition, we examined the effects of a complement and interferon-beta (IFN-beta) on the outcome of the selection. As a result, the complement slowed the selection of a syncytial variant, whereas IFN-beta facilitated it.

Cell Line↗

PubMed1997

Psychiatric manifestations accompanying interferon therapy for patients with chronic hepatitis C: an overview of cases in Japan.

Thirty case reports published in Japan that refer to psychiatric symptoms accompanying interferon (IFN) therapy were examined. These papers covered a total of 49 cases. We categorized these 49 cases into 35 cases of mood disorder, 10 of delirium and four of psychotic disorder. The key findings of our study of these cases are as follows: (i) in total, 11 patients had psychiatric past histories: five patients in the mood disorders group were susceptible to the influence of social or psychological factors; (ii) whereas the symptoms of mood disorder or delirium appeared soon after IFN was administered, the symptoms of psychotic disorders appeared later. The patients with delirium displayed many neurological abnormalities, which were reduced by suspending IFN therapy. This suggests the neurological toxicity of IFN; (iii) the outcome of most patients was good; and (iv) we suspect that IFN-induced psychiatric symptoms other than delirium are connected with psychoneuroimmunological functions.

Delirium↗

PubMed1997

Correlation of p53 protein expression with gene mutation in gall-bladder carcinomas.

The correlation of p53 protein expression and p53 mutation of 33 gall-bladder carcinomas was studied according to the depth of invasion and grade of cytological atypia. Overexpression of p53 protein was detected by immunostaining in seven (70.0%) of 10 intramucosal and in 16 (69.6%) of 23 invasive carcinomas. p53 mutation was detected in five (71.4%) of the seven intramucosal carcinomas with overexpression and in eight (50.0%) of the 16 invasive cancers with overexpression and in one (10%) of the 10 non-overexpressing carcinomas at exons 5-8 by nested polymerase chain reaction-single-strand conformation polymorphism. The overexpression of p53 protein was present in nine (56.3%) of 16 low-grade carcinomas and in 14 (82.3%) of 17 high-grade carcinomas. In cases of overexpression, p53 mutation was detectable in four (44.4%) of nine low-grade and in nine (64.3%) of 14 high-grade carcinomas. In total, p53 mutation was verified in 56.5% (13/23) of cases involving protein overexpression and in 10% (1/10) of cases of non-overexpression. The sensitivity of p53 mutation was 56.5% (13/23), the specificity was 90.0% (9/10) and the validity was 1.47. In conclusion, our study indicates that p53 protein overexpression correlates well with gene mutation and that p53 alteration may be related to increasing grade of cytologic atypia of carcinomas.

Adenocarcinoma↗

PubMed1997

Acute fulminant ulcerative colitis with toxic megacolon.

An 11-year-old boy with acute fulminant ulcerative colitis (UC) is presented. He had systemic deterioration with frequent diarrhea and lethargy. Acute fulminant UC associated with toxic megacolon was diagnosed by rectal endoscopy and biopsied specimen. He was treated with intensive intravenous administration of prednisolone and total parenteral nutrition. He recovered completely without any surgical intervention.

Acute Disease↗

PubMed1997

Testosterone replacement therapy for male hypogonadism with a radiation-polymerized testicular prosthesis.

BACKGROUND: The effect of an artificial testicular prosthesis on sexual disturbance in hypogonadal men was investigated. METHODS: Twelve hypogonadal men were treated with testosterone replacement therapy delivered via radiation-polymerized testicular prostheses surgically implanted in their scrotums. RESULTS: An average serum testosterone level of over 200 ng/dL was maintained for 48 months. Most patients treated with this prosthesis were satisfied with the improvement of their sexual activity. Moreover, the patients were psychologically more satisfied with the enlarged scrotum achieved with the implanted prosthesis. CONCLUSION: We recommend this prosthesis as the first choice among testosterone-replacement therapies for hypogonadal men.

Adolescent↗

PubMed1997

Prognostic factors of hemophagocytic syndrome in adults: analysis of 34 cases.

Hemophagocytic syndrome (HPS) presents with fever, pancytopenia, liver dysfunction and increase in hemophagocytic histiocytes in various organs. Although there are two major classifications of HPS in adults, malignant and reactive histiocytosis, it is often very difficult to distinguish between these disorders. We analyzed the laboratory data of patients with HPS to evaluate prognostic factors. Of 34 patients, 14 survived, and 20 died. The median age of survivors was 29.6+/-11.5 yr significantly younger than those who died (54.7+/-17.8 yr). Twenty patients had no obvious underlying disease, the other 13 had hematological malignancies or viral infections. Comparison of laboratory data revealed that nonsurvivors had significantly lower Hb and platelet values on admission. During treatment, worsening of anemia and thrombocytopenia, increase of transaminase and biliary enzymes were similarly more prominent. Risk factors associated with death were: age over 30 yr, presence of disseminated intravascular coagulation, increased ferritin and beta2-microglobulin, anemia accompanied by thrombocytopenia and jaundice. Our data suggests that patients with HPS and any of these risk factors should be treated aggressively with sufficient chemotherapy and supportive care.

Adolescent↗

PubMed1997

Treatment of experimental allergic encephalomyelitis by selective removal of CD4+ T cells.

Experimental allergic encephalomyelitis (EAE) is a major animal model of human multiple sclerosis (MS). The pathogenesis of both MS and EAE directly involves CD4+ helper T cells. To remove CD4+ T cells selectively from the circulation, we designed a new column in which anti-CD4 monoclonal antibody was immobilized on the activated substance. Most of the CD4+ T cells, including pathogenic T cells, were selectively adsorbed from whole blood with a direct perfusion through the column in vitro, resulting in depletion of the antigen-specific T cell responses. A preliminary trial of ex vivo treatment with the column in EAE rats lowered the percentages of CD4+ populations but failed to alter the course of the disease, suggesting repeated treatment would be necessary to suppress the development of the disease. We conclude that this new column is potentially useful, and repeated treatment would be beneficial in MS and other CD4+ T cell dependent autoimmune diseases.

Animals↗

PubMed1997

Clinical evaluation of the serodiagnostic value of enzyme-linked immunosorbent assay for Rhodococcus equi infection in foals.

An enzyme-linked immunosorbent assay (ELISA) for detection of serum IgG antibodies against Tween 20-extracted antigen of strain ATCC 6939 was applied in Hidaka, Japan to a total of 752 sick foals showing a variety of signs of infectious disease. An optical density (OD) value of more than 0.3 was tentatively fixed to be positive on the basis of readings made of healthy horse sera in previous studies. During a 2 year study, 138 of the 752 sick foals showed an OD value of 0.3 or higher and were designated as 'suspected of R. equi infection'. Age distribution during the initial medical examination of the 138 seropositive foals was significant in that most (64%) foals were age 31-60 days, with a sharp decrease in subjects beyond that age. Of the 138 foals suspected of having R. equi infection, 34 foals (25%) showed OD values of over 0.9 at the initial medical examination, in addition to high blood leucocyte counts and serum fibrinogen and alpha-globulin values. The infectious foals had been treated with antibiotics just before and after serodiagnosis and 126 foals (91%) recovered from the disease. However, no clinical improvement was observed in 12 foals (9%). At necropsy, these foals revealed suppurative pneumonia and lymphadenitis of gut associated lymph nodes accompanied by abdominal abscesses. All isolates from the pulmonary and abdominal abscesses revealed R. equi. These results suggest that OD readings in the high range are associated with severe disseminated infection with R. equi.

Actinomycetales Infections↗

PubMed1997

[An autopsy case of chronic granulomatous disease diagnosed by biopsy].

This report concerns a male patient aged 25 years, diagnosed at the age of 12 years as suffering from chronic granulomatous disease. This patient had p47-phox deficiency. He was admitted to this hospital because of fever and dyspnea accompanied by right spontaneous pneumothorax. He failed to respond to medical treatment. He died from respiratory failure four months after admission. Autopsy demonstrated pigmented lipid histiocytes characteristic of CGD. These characteristic pigmented cells were distributed in the spleen, liver, lymph nodes and in the small intestine. As for the nature of the pigment, lipofuschin-like compound were identified. Granulomatous component was seen in the mucosa of the stomach obtained by operation. The presence and characteristic distribution of such pigmented macrophages in tissue in young adults may suggest the diagnosis of CGD.

Adult↗

PubMed1997

Cloning of genes coding for L-sorbose and L-sorbosone dehydrogenases from Gluconobacter oxydans and microbial production of 2-keto-L-gulonate, a precursor of L-ascorbic acid, in a recombinant G. oxydans strain.

We have purified L-sorbose dehydrogenase (SDH) and L-sorbosone dehydrogenase (SNDH) from Gluconobacter oxydans T-100 that showed an ability to convert D-sorbitol to 2-keto-L-gulonate (2-KLGA). A genomic library of Gluconobacter oxydans T-100 was screened with a probe, a 180-bp PCR product which was obtained from degenerate oligodeoxyribonucleotides based on the elucidated sequence of the purified SDH (used as primers) and the genomic DNA of G. oxydans T-100 (used as a template). From sequencing of the DNA from a clone positive to the probe, the SNDH and the SDH were estimated to be coded in sequential open reading frames with 1,497 and 1,599 nucleotides, respectively, which was confirmed by expression of the DNA in Escherichia coli that showed both enzymatic activities. The DNA was introduced to a shuttle vector which was prepared from a plasmid of G. oxydans T-100 and pHSG298 to obtain an expression vector designated pSDH155. The production of 2-KLGA by pSDH155 in G. oxydans G624, an L-sorbose-accumulating strain, was improved to 230% compared to that of G. oxydans T-100. Chemical mutation of the host strain to suppress the L-idonate pathway and replacement of the original promoter with that of E. coli tufB resulted in improving the production of 2-KLGA. Consequently, high-level production from D-sorbitol to 2-KLGA (130 mg/ml) was achieved by simple fermentation of the recombinant Gluconobacter.

Acetobacteraceae↗

PubMed1997

Hemoglobin increases mortality from bacterial endotoxin.

Cell-free hemoglobin (Hb) is being developed as an erythrocyte substitute. We have previously demonstrated that cell-free Hb is an endotoxin-binding protein which disaggregates endotoxin and subsequently increases the biological activity of endotoxin in several in vitro assays. Because much of the morbidity and mortality associated with gram-negative bacterial infection is the result of pathophysiologic responses to bacterial lipopolysaccharide (LPS; endotoxin), we studied the effect of Hb on LPS-mediated mortality. Hb infused intravenously into mice before, coincident with, or after intraperitoneal LPS injection substantially increased LPS-related mortality from <5% to 50 to 70% 24 h after administration of LPS and from 50% to 60 to 90% at 48 h. Enhanced mortality was observed over a range of doses of injected LPS. At a given LPS dose, enhancement of mortality was shown to be dependent on the dose of Hb administered. Unmodified native human Hb, alpha-alpha-cross-linked human Hb, and beta-beta-cross-linked human or bovine Hb all were shown to enhance LPS-mediated mortality. Depressed reticuloendothelial cell function may have contributed to the enhanced mortality from LPS in the presence of Hb. Therefore, Hb-based blood substitutes, which are currently undergoing clinical trials, may intensify the potentially fatal effects of the sepsis syndrome in patients with trauma, infection, or hypotension who receive Hb for erythrocyte replacement.

Animals↗