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Biomedical subjects

T Nakazawa

Publications and source records attributed to T Nakazawa.

At least 91 records · Page 5Linked to original sources
PubMed2000

Hemolytic uremic syndrome associated with influenza A virus infection in an adult renal allograft recipient: case report and review of the literature.

Hemolytic uremic syndrome (HUS) is a rare but serious complication following renal transplantation. It usually develops early after transplantation, and ciclosporin treatment is the most common triggering factor. We report the case of a 35-year-old male with posttransplant HUS which developed 1 year after renal transplantation. He became febrile 4 days before the onset of HUS, and the significant rise in viral titer confirmed the diagnosis of influenza A virus infection. The association of ciclosporin treatment with HUS was unlikely, because of the late onset of HUS and the low ciclosporin trough levels. The patient was treated successfully without a dose reduction of ciclosporin. An etiologic relationship between influenza A virus and HUS was highly probable in our patient. We also review a total of 156 adult cases with HUS after renal transplantation described in the literature. The prognosis of posttransplant HUS differs according to the cause. The advent of ciclosporin has improved the graft survival rate and mortality of patients with rejection-induced HUS.

Adult↗
PubMed2000

Regulation of CD69 expression on eosinophil precursors by interferon-gamma.

The purpose of this study was to determine whether interferon-gamma (IFN-gamma) induced CD69 expression by eosinophil precursors. Eosinophil precursors were induced from CD34+ cord blood cells using recombinant human interleukin-3 (IL-3) and interleukin-5 (IL-5). On day 14 of culture, cells constitutively expressed CD69 and the IFN-gamma receptor (IFN-gammaR). Stimulation with IFN-gamma for 24 h did not affect IFN-gammaR expression by the cells. On the other hand, IFN-gamma significantly upregulated CD69 expression by the precursors after 24 h of incubation. A specific JAK2 inhibitor (AG-490) caused a concentration-dependent suppression of IFN-gamma-induced CD69 expression by the precursors. In conclusion, these results indicate that IFN-gamma induces CD69 expression by eosinophil precursors via the activation of JAK2.

Antigens, CD↗
PubMed2000

Effects of N-acetylcysteine and ambroxol on the production of IL-12 and IL-10 in human alveolar macrophages.

BACKGROUND: N-acetylcysteine (NAC) and ambroxol (AMB) have recently been proposed as possible therapeutic agents in the treatment of pulmonary disorders. IL-12 plays an important role in host resistance to infection and the development of Th-1 cells. In contrast, IL-10 is involved in anti-inflammatory and immunoregulatory mechanisms. OBJECTIVE: We investigated the effects of NAC and AMB on secretions of IL-12 and IL-10 from human alveolar macrophages. METHODS: Alveolar macrophages were obtained from 7 healthy nonsmokers by bronchoalveolar lavage. The cells were first incubated with either NAC or AMB for 2 h and then cultured in lipopolysaccharide (LPS) solution for 24 h. IL-12 and IL-10 secretions were measured by ELISA. RESULT: Both NAC and AMB enhanced LPS-induced secretion of IL-12. NAC also enhanced LPS-induced IL-10 secretion, while AMB did not. The ratio IL-12/IL-10 secretion was increased by AMB, but NAC did not affect it. CONCLUSIONS: The results suggest that NAC enhances inflammatory and immune responses and prevents excessive responses reciprocally, through keeping local balance of IL-12 and IL-10 production in alveolar macrophages at inflammatory sites of bacterial pneumonia. AMB appears to strengthen inflammatory responses and cell-mediated immunity, facilitating the development of Th-1 cells, through shifting the local balance to IL-12 dominance.

Acetylcysteine↗
PubMed2000

Metabolites of orally administered Perilla frutescens extract in rats and humans.

As a part of our search for bioactive substances from the leaves of Perilla frutescens BRITTON var. acuta KUDO (Perillae Herba, Labiatae), the aqueous extract was orally administered to rats and humans, and metabolites in the urine, plasma, and/or bile were analyzed by a high-performance liquid chromatograph (HPLC) equipped with a photodiode array detector. When the extract was administered to rats, 10 metabolites, trans-caffeic acid-4-O-sulfate (1), trans-p-coumaric acid-4-O-sulfate (2), trans-ferulic acid-4-O-sulfate (3), trans-m-coumaric acid-3-O-sulfate (4), trans-caffeic acid (5), m-hydroxyphenylpropionic acid (6), trans-p-coumaric acid (7), trans-m-coumaric acid (8), luteolin (9), and apigenin (10) were detected in the urine, whereas four metabolites, scutellarein-6, 7-di-O-beta-glucuronide (11), apigenin-4'-O-sulfate-7-O-beta-glucuronide (12), apigenin-7-O-beta-glucuronide (13), and diosmetin-7-O-beta-glucuronide (14) were found in the bile. Compounds 1-8 and 11-14 were also found in the plasma. When the extract was given to humans, however, two metabolites, 1-O-(2,4,5-trimethoxycinnamoyl)-beta-glucuronic acid (15) and apigenin-4'-O-beta-glucuronide (16), were found in the urine and plasma. Thus, a species difference in the metabolism of the extract constituents was observed between rats and humans. Structures 1-16 were identified based on their chemical and spectral data.

Administration, Oral↗
PubMed2000

Cloning and characterization of EPD2, a gene required for efficient pseudohyphal formation of a dimorphic yeast, Candida maltosa.

Candida maltosa is a dimorphic fungus and its pseudohyphal growth is partly induced by additional copies of the centromeric DNA (CEN) region1) or n-alkane. In the course of analyzing the induction mechanism of pseudohyphal growth, we isolated EPD1, which is similar in sequence to PHR1 and PHR2 of Candida albicans. Epdlp could be involved in cell wall maintenance and is essential for pseudohyphal growth induced by CEN and n-hexadecane at pH 4 and by n-hexadecane at pH 7.) In this paper, we cloned EPD2 of C. maltosa, which is highly similar to EPD1, PHR1, and PHR2. The transcription of EPD2 is induced strongly when cells are grown in SD medium of higher pH (pH 7), but not in SD medium of lower pH (pH 4). This pattern of expression was an inverse of that of EPD1. This alternate expression is similar to that between PHR1 and PHR2. The expression of EPD2 was much higher when C. maltosa was grown on the n-hexadecane solid medium than grown in the n-hexadecane liquid medium. The efficiency of pseudohyphal formation of an epd2 null mutant on n-hexadecane medium at pH 7 or 7.5 was lower than that of the wild-type strain. These results suggest that Epd2p is required for efficient pseudohyphal formation induced by n-hexadecane in the medium at pH 7.

Amino Acid Sequence↗
PubMed2000

Mixed carcinoid-adenocarcinoma of the liver.

A 61-year-old man with a mixed carcinoid-adenocarcinoma of the liver is described. Microscopic examination of the lesion showed a differentiated adenocarcinoma with distinct carcinoid components that stained positively for argyrophil. The tumor cells contained serotonin granules on immunohistochemical studies. Detailed examination disclosed no primary tumor in the gastrointestinal tract or in any other organ. Resection was considered impractical because there were multiple tumors. The patient received chemotherapy six times (cisplatin 60 mg/m2, epirubicin 40 mg/ m2 per month). The multiple tumors gradually shrank. At the time of this writing, the patient is still alive. To our knowledge, this is the first reported case of mixed carcinoid-adenocarcinoma of the liver.

Adenocarcinoma↗
PubMed2000

[Efficacy of preventive treatment for complications in percutaneous endoscopic gastrostomy in elderly].

From September 1995 through May 1999, percutaneous endoscopic gastrostomy (PEG) was performed in 47 elderly patients, aged 65 to 93 (average 78.9). Several treatments were additionally performed to prevent serious complications in these cases, and their usefulness and problems were investigated. Gastropexy was performed to prevent peritonitis in cases of self-removal of tubes in the acute stage. Intraoperative fluoroscopy was used prevent perforation of the intestines. However, re-insertion of the endoscopic, which was necessary with the push method, was omitted to reduce the burden on the patients. In patients with tube troubles in the chronic stage such as the buried bumper syndrome or self-removal, the existing fistula was preserved and the gastrostomy was reconstructed using a narrow polyvinyl chloride tube and a flexible guide wire to prevent peritonitis by erroneous insertion of the tube. In terms of results, gastropexy was useful to prevent peritonitis in one patient with early self-removal of the tube. Data to evaluate the usefulness of fluoroscopy in preventing perforation of the intestine were insufficient, so more patients need to be studied in the future. Even when confirmation of the location of the internal bumper by endoscopy was omitted, there was no case of poor traction of the bumper, so this procedure seems unnecessary. Review of tube troubles, in the chronic stage revealed no case of peritonitis caused by erroneous insertion of tubes or erroneous injection of nutrients with our reconstruction methods, and complete reconstruction of the gastrostomy with preservation of the existing fistula appeared to be possible. However, those additional treatments require extension of the operation time and rise in cost with increased use of medical instruments, so the indications should be carefully considered.

Aged↗
PubMed2000

[A case of pulmonary tuberculosis complicated with subcutaneous phaeohyphomycosis].

A 78-year-old male was admitted to our hospital because of fever, sputum and cough. Chest X-ray showed infiltrative shadows in the right lung field. Smears of his sputum were positive for acid-fast bacilli. We found multiple subcutaneous abscesses on the right distal forearm. Microscopic examination of skin biopsy specimens revealed granulation tissues with the proliferation of epitheloid cells with the scattering infiltrations of neurophils, giant cells and histiocytic cells. The examination of the PAS stained specimen revealed fungal elements and a black fungus, Exophiala jeanselmei, was isolated by the cultures of pus from the abscess. He was diagnosed as pulmonary tuberculosis complicated with subcutaneous phaeohyphomycosis caused by Exophiala jeanselmei and was successfully treated with anti-tuberculosis drugs and anti-fungal agent, 5-fluorocytosine.

Aged↗
PubMed2000

[The frequency profile of tuberculin skin testing among employees of a hospital].

The frequency profile of tuberculin skin testing among employees of a hospital was studied. In the analysis, tuberculin skin testing was defined as "negative" if skin rash is measured < or = 9 mm, and as "positive" if skin rash is measured > or = 10 mm, and as "strongly positive" if skin rash is measured > or = 10 mm, with induration, and double skin rash or bulla. Boosting was defined as initial skin rash was measured < or = 9 mm, with second skin rash measured > or = 10 mm and at least 6 mm increase of rash than the initial one. 544 employees were tested initially, and 81 were retested. Initial tuberculin positivity was associated with older age (p < 0.001); but boosting was not associated with age and occupation. Comparing pharmacists with other groups, the adjusted odds ratio of an initial strongly positive tuberculin reaction as significantly higher, namely 2.8 (95% confidence interval 1.2-6.7), but that of a booster reaction was 4.8 (0.7-32.1) which was insignificant.

Adult↗
PubMed2000

[Genome analysis of pathogenic bacteria--a review].

The whole genome information on pathogenic bacteria opened a new era of medical microbiology. Bacteria have a variety of strategies to survive in human body against host defense. Bacteria colonizing on the mucous cell surface and proliferate extracellularly have developed a number of paralogs of surface proteins for antigenic variation, while bacteria which proliferate intracellularly have acquired genes for invasion and anti-active oxygen. The obligate intracellular parasites, Rickettsiae and Chlamydiae, have developed a distinct energy metabolism depending on the intracellular localization; Rickettsia prowazekii has TCA cycle and oxidative phosphorylation to proliferate in the cytoplasm, while Chlamydiae have a glycolytic pathway and substrate-level phosphorylation to multiply within an organella called inclusion bodies.

Antigenic Variation↗
PubMed2000

Smooth muscle cell migration induced by shear-loaded platelets and endothelial cells. Enhanced platelet-derived growth factor production by shear-loaded platelets.

BACKGROUND: Uncontrolled migration and proliferation of smooth muscle cells (SMC) are the main mechanisms of development of atherosclerotic neointima. However, it has not yet been elucidated how mechanical stress is involved in this process. We investigated smooth muscle cell mitogenic activity induced by shear-loaded platelets and endothelial cells. METHODS EXPERIMENTAL DESIGN: in vitro experimental study. We devised four types of conditioned media; supernatant of mixed culture of platelets and endothelial cell (ST), supernatant of shear-loaded mixed culture of platelets and endothelial cell (SH), ST medium neutralised with anti-PDGF antibody (ST+), and SH medium neutralised with anti-PDGF antibody (SH+). Smooth muscle cells were cultured in each conditioned medium, and their spreading activity was determined under a microscope. RESULTS: Smooth muscle cells spreading activity in the SH group was significantly greater than that in the ST group. Their spreading activity was suppressed by anti-PDGF antibody under shear conditions (SH+), but it was not by anti-PDGF antibody under static conditions (ST+). CONCLUSIONS: Our results demonstrate that platelet-derived growth factor is produced by shear-loaded platelets and endothelial cells, and local mechanical forces may play an important role in cardiovascular disease.

Blood Platelets↗
PubMed2000

[Asthma death among adults in Japan 1995-1997. Analysis of 295 cases reported questionnaires sent to hospitals with more than 100 beds. Asthma Death Investigation Committee].

To clarify recent trends in adult asthma mortality, the Asthma Death Investigation Committee of Japan studied the clinical characteristics of 295 patients who died of asthma between 1995 and 1997. Males were slightly more than females among the death cases. Approximately half of the patients ranged in age from 60 to 79 years. Tendency to increase of death among young male adults continued. One third of the patient deaths involved the asphyxic type, while status asthmaticus was the cause death in 21.9%. Half of the asthmatics died in hospitals or emergency rooms, and places where the fatal attacks occurred were mainly patients' houses. The main cause fatal asthma attacks was respiratory infection, followed by fatigue, stress, and discontinuation of medication. Most of the patients were classified moderate or severe type of asthma 1 month before death. Histories of life-threatening attacks and hospitalization due to severe attacks, irregular visits to the hospital, low compliance, and insufficiency of corticosteroid treatment were suggested as the main risk factors in adult asthma deaths.

Adolescent↗
PubMed2000

Cerebral artery selective inhibition of protein kinase c-mediated contraction by hns-32, a novel azulene-1-carboxamidine derivative.

The vasorelaxant actions of a novel azulene-1-carboxamidine derivative, HNS-32, were investigated on the tension development evoked by phorbol 12, 13 dibutyrate (PDBu) in cerebral and femoral arteries isolated from the dogs. In basilar artery, HNS-32 inhibited almost completely PDBu-induced contraction in a concentration-dependent manner with potency about 10 times stronger than that of fasudil, a protein kinase inhibitor. In contrast, in femoral artery, HNS-32 failed to suppress the tension development in response to PDBu whereas fasudil inhibited it with a similar potency as in basilar artery. These findings indicate that HNS-32 selectively suppresses cerebral artery contraction mediated via an activation of protein kinase C.

Animals↗
PubMed1999

Activation of Helicobacter pylori ureA promoter by a hybrid Escherichia coli-H. pylori rpoD gene in E. coli.

We constructed and analyzed hybrid Escherichia coli-Helicobacter pylori rpoD genes in an E. coli rpoD mutant. It turned out that a hybrid consisting of E. coli rpoD with subdomain 4.2 of H. pylori rpoD (for -35 recognition) was functional. On the other hand, hybrids consisting of E. coli rpoD with domain 2 and the adjacent sequence of H. pylori rpoD (for core enzyme binding and -10 recognition) were non-functional. Intriguingly, a hybrid rpoD containing H. pylori subdomain 4.2 conferred higher activity for the H. pylori PureA as determined by xylE expression of PureA-xylE fusions, although the activity of the hybrid rpoD for the tac promoter was comparable to that of E. coli rpoD. The tsp of ureA in E. coli with the hybrid rpoD and E. coli rpoD were 15 and 17bp upstream from that in H. pylori, respectively. The comparison of PureA sequences in both E. coli and H. pylori indicated the existence of a -10 consensus sequence but little conservation of -35 sequences. Instead, the PureA in both H. pylori and E. coli contained an identical heptamer, GTTAATA, in the extended -35 region.

Amino Acid Sequence↗
PubMed1999

Primary chemically induced tumors induce profound immunosuppression concomitant with apoptosis and alterations in signal transduction in T cells and NK cells.

Whereas transplantable tumors can be readily cured with immunotherapeutic approaches, similar therapies in cancer patients have been less effective. This difference may be explained by an immunosuppression resulting from the presence of a slowly growing primary tumor in the patient, whereas the immune system in a mouse with a rapidly proliferating transplantable tumor would be less affected. As a more appropriate model to the immune dysfunction in patients, slowly progressing primary tumors were induced by the carcinogen methylcholanthrene (MC) in mice. Their ability to induce immunosuppression in T cells and natural killer (NK) cells was compared to that of rapidly growing transplanted MC-induced tumors. The results demonstrate that mice bearing primary MC tumors had significantly diminished T-cell and NK-cell functions, impaired capacity to produce Th1 cytokines, and markedly reduced levels of the signal-transducing zeta chain in T cells and NK cells, similar to that described in cancer patients. Moreover, a substantial number of CD8+ T cells in mice with large primary MC tumors were undergoing apoptosis, correlating with alterations in CD4/CD8 ratios. In contrast, T cells and NK cells from mice bearing rapidly growing transplanted tumors were only marginally affected. These findings could explain the apparent discrepancy between the consistent findings of a diminished immune response and alterations in signal transduction in cancer patients as compared to the less reproducible observations in murine transplantable tumors. In addition, they could explain the differences in the high efficacy of immunotherapy in mice with transplantable tumors and the low therapeutic results in cancer patients.

Animals↗