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Biomedical subjects

I Sugawara

Publications and source records attributed to I Sugawara.

At least 37 records · Page 2Linked to original sources
PubMed2000

Secondary infections of AIDS autopsy cases in Japan with special emphasis on Mycobacterium avium-intracellulare complex infection.

In order to study the frequency of secondary infections of AIDS autopsy cases in Japan, especially the frequency of Mycobacterium aviumintracellulare complex (MAC) infection, retrospective autopsy study was conducted between 1986 and 1997 at the affiliated hospital of Institute of Medical Sciences, University of Tokyo. Secondary infections of various organs from 43 AIDS autopsy cases were examined using histopathology, genetic diagnosis of tuberculosis, Ziehl-Neelsen stain for acid-fast bacilli and immunohistochemistry. Nontuberculous mycobacterial infection (Mycobacterium avium) was observed in 17 cases (40%) out of 43 using polymerase chain reaction (PCR), but M. tuberculosis infection was not observed. Ziehl-Neelsen staining showed a positive reaction in lung and spleen tissues of 7 AIDS autopsy cases. Immunohistochemistry using anti-BCG antibody revealed positivity in 7 AIDS autopsy cases. CD4 counts of 17 AIDS patients with mycobacterial infection were less than 18.7/microl. Other opportunistic infections were also examined by histopathology. Secondary infections were present in every case, and these included cytomegalovirus infection (32 cases), Pneumocystis carinii (15 cases), Candida (16 cases), Aspergillus (12 cases), Cryptococcus (6 cases), Toxoplasma (6 cases), methicillin-resistant Staphylococcus aureus (3 cases), herpes virus (1 case) and Entamoeba histolytica (1 case). Malignant lymphoma was recognized in 14 cases and Kaposi's sarcoma in 6. This is the systemic report on secondary infections of AIDS autopsy cases in Japan. In diagnosis of mycobacterial infections, PCR was more useful than staining for acid-fast bacilli and immunohistochemistry. Secondary infections (especially mycobacterial infection) were closely associated with the low CD4 count.

AIDS-Related Opportunistic Infections↗
PubMed2000

[Optimal conditions for establishment of experimental tuberculosis model using an automated inhalation exposure apparatus and its application].

Animal (mouse and guinea pig) pulmonary tuberculosis models were established, using an automated inhalation exposure apparatus (Glas-Col Corp., USA, Model 099CA-4212). This apparatus includes four steps--preheating, nebulization, cloud decay and decontamination. The optimal conditions for M. tuberculosis H37Rv strain infection experiments were as follows: 10(5-6) colony forming unit (cfu) tubercle bacilli; preheating for 15 min.; nebulization for 90 min.; cloud decay for 15 min. and decontamination for 5 min. When 10(4) cfu M. tuberculosis H37Rv strain were introduced into the lungs of interferon (IFN)-gamma knockout mice, using the inhalation exposure apparatus and were followed up for 9 months, the primitive cavitary lesions were observed. This apparatus was also useful for inhalation exposure experiments of guinea pigs. This apparatus can also be utilized for animal inhalation experiments of allergens.

Animals↗
PubMed1999

Human monoclonal antibody 28K29 highly reactive with lung adenocarcinomas of all grades of differentiation and with large cell carcinomas.

Human monoclonal antibody (mAb) 28K29 was previously established by fusing regional lymphocytes from a lung adenocarcinoma patient with human-mouse heteromyeloma. This mAb was shown to have an antigen localized in the membrane and cytoplasm of lung cancer cells. This mAb was investigated for reaction with tissue sections from formalin-fixed paraffin-embedded blocks from 100 patients with lung cancer. The mAb 28K29 reacted with 83% (5/6) of the well-differentiated, 79% (22/28) of the moderately-differentiated, and 67% (4/6) of the poorly-differentiated lung adenocarcinoma sections. The mAb also reacted with 35% (14/40) of the squamous cell carcinoma sections, 70% (7/10) of the large cell carcinoma sections, and 20% (2/10) of the small cell carcinoma sections. In Western blot analyses, a broad band at a molecular weight of approximately 600 kDa was detected in extracts from the lung cancer tissues positive for immunohistostaining with the mAb 28K29. The results of the study suggest that the expression of the 28K29 antigen is independent of the histological differentiation grade in lung adenocarcinoma and that this antigen might be a useful marker for detection of both large cell carcinoma and adenocarcinoma of the lung as well as for investigation of the putative transition of large cell carcinoma to adenocarcinoma proposed by Yesner.

Adenocarcinoma↗
PubMed1999

Exposure to diesel exhaust affects the male reproductive system of mice.

Several recent reports have suggested that sperm count and quality in normal men are declining. Various environmental chemical compounds may affect the male reproductive system. We propose here that diesel exhaust is an environmental pollutant with the potential to influence male reproductive function. Ultrastructural changes were observed in Leydig cells of mice exposed to diesel exhaust (0.3 mg diesel exhaust particles (DEP)/m3 through the airway, 12 h daily, up to 6 months) and reduction in LH receptor mRNA expression in Leydig cells was observed at a concentration of 1 mg DEP/m3. Daily sperm production per gram of testis dose-dependently decreased with exposure to DE for 6 months; 29%, 36%, and 53% reductions were observed at 0.3, 1.0, and 3.0 mg DEP/m3, respectively. A no-observed-adverse-effect level (NOAEL) was observed with approximately 30 micrograms DEP/m3, which is lower than the WHO-recommended limit.

Air Pollutants↗
PubMed1999

Pre-operative localization and tissue uptake study in parathyroid imaging with technetium-99m-sestamibi.

BACKGROUND: The diagnostic ability of 99mTc-sestamibi was compared with other techniques and the mechanism of parathyroid uptake was investigated. METHODS: Double-phase 99mTc-sestamibi scanning was performed in 52 primary and 28 renal hyperparathyroidism patients. Gene expressions of mdr1 and mrp were examined by reverse transcriptase polymerase chain reaction in parathyroid tissue. RESULTS: The sensitivity of 99Tc-sestamibi in primary and renal hyperparathyroidism was 91% and 75%, respectively, higher than for ultrasonography, T1/Tc subtraction scintigraphy, or computed tomography. Early 99mTc-sestamibi uptake was washed out in delayed images in 7% and 30% of glands in primary and renal hyperparathyroidism, respectively. Expression of mdr1 and mrp mRNA was found in 5 of 23 and 16 of 31 glands, respectively, and their expression correlated with washout in delayed images. CONCLUSION: 99mTc-sestamibi was the best localization test. mdr1 and mrp were associated with 99Tc-sestamibi washout, but their role in the parathyroid remains unclear.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Role of interleukin-18 (IL-18) in mycobacterial infection in IL-18-gene-disrupted mice.

Immunity to mycobacterial infection is closely linked to the emergence of T cells that secrete cytokines, gamma interferon (IFN-gamma), interleukin-12 (IL-12), and tumor necrosis factor alpha (TNF-alpha), resulting in macrophage activation and recruitment of circulating monocytes to initiate chronic granuloma formation. The cytokine that mediates macrophage activation is IFN-gamma, and, like IL-12, IL-18 was shown to activate Th1 cells and induce IFN-gamma production by these cells. In order to investigate the role of IL-18 in mycobacterial infection, IL-18-deficient mice were infected with Mycobacterium tuberculosis and Mycobacterium bovis BCG Pasteur, and their capacities to control bacterial growth, granuloma formation, cytokine secretion, and NO production were examined. These mice developed marked granulomatous, but not necrotic, lesions in their lungs and spleens. Compared with the levels in wild-type mice, the splenic IFN-gamma levels were low but the IL-12 levels were normal in IL-18-deficient mice. The reduced IFN-gamma production was not secondary to reduced induction of IL-12 production. The levels of NO production by peritoneal macrophages of IL-18-deficient and wild-type mice did not differ significantly. Granulomatous lesion development by IL-18-deficient mice was inhibited significantly by treatment with exogenous recombinant IL-18. Therefore, IL-18 is important for the generation of protective immunity to mycobacteria, and its main function is the induction of IFN-gamma expression.

Animals↗
PubMed1999

Role of tumor necrosis factor-alpha in Mycobacterium-induced granuloma formation in tumor necrosis factor-alpha-deficient mice.

To study the role of TNF-alpha in mycobacterial infection, we generated TNF-alpha-knockout (KO) mice, in which the third and fourth exons of the TNF-alpha gene were disrupted. The C57BL/6 KO mice were injected with virulent Mycobacterium tuberculosis strain Kurono or avirulent bacillus Calmette-Guérin (BCG) Pasteur (10(6) colony-forming units), through the tail veins. The major organs were removed at weekly intervals, and morphologic observation, assays of IL-1, IL-12, IFN-gamma, and inducible nitric oxide synthase mRNA expression, and colony counts in the lungs and spleen were performed. Peritoneal macrophages from BCG- and H37Rv strain-treated mice produced significant levels of nitric oxide after stimulation in vitro. Formation of abscesses was seen only in the Kurono-treated groups, and these abscesses contained large numbers of mycobacteria. The administration of recombinant TNF-alpha significantly ameliorated the mycobacterial lesions. IFN-gamma mRNA was expressed significantly in virulent H37Rv-treated groups with time, and the number of mycobacterial colonies per unit weight increased remarkably with time. Nitric oxide production was not observed in H37Rv-treated groups but was seen in BCG-treated groups. We concluded that TNF-alpha played an important role in protective immunity against virulent mycobacteria. Because avirulent mycobacteria did not induce granulomas in TNF-alpha-KO mice, TNF-alpha played an indirect role in granuloma formation.

Animals↗
PubMed1998

A physiologic function for p-glycoprotein (MDR-1) during the migration of dendritic cells from skin via afferent lymphatic vessels.

P-glycoprotein (MDR-1) is a well-known transporter that mediates efflux of chemotherapeutic agents from the intracellular milieu and thereby contributes to drug resistance. MDR-1 also is expressed by nonmalignant cells, including leukocytes, but physiologic functions for MDR-1 are poorly defined. Using an initial screening assay that included >100 mAbs, we observed that neutralizing mAbs MRK16, UIC2, and 4E3 against MDR-1 specifically and potently blocked basal-to-apical transendothelial migration of mononuclear phagocytes, a process that may mimic their migration into lymphatic vessels. Antagonists of MDR-1 then were used in a model of authentic lymphatic clearance. In this model, antigen-presenting dendritic cells (DC) migrate out of explants of cultured human skin and into the culture medium via dermal lymphatic vessels. DC and T cells derived from skin expressed MDR-1 on their surfaces. Addition of anti-MDR-1 mAbs MRK16, UIC2, or the MDR-1 antagonist verapamil to skin explants at the onset of culture inhibited the appearance of DC, and accompanying T cells, in the culture medium by approximately 70%. Isotype-matched control mAbs against other DC molecules including CD18, CD31, and major histocompatibility complex I did not block. In the presence of MDR-1 antagonists, epidermal DC were retained in the epidermis, in contrast to control conditions. In summary, this work identifies a physiologic function for MDR-1 during the mobilization of DC and begins to elucidate how these critical antigen-presenting cells migrate from the periphery to lymph nodes to initiate T lymphocyte-mediated immunity.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Inhibition of P-glycoprotein and recovery of drug sensitivity of human acute leukemic blast cells by multidrug resistance gene (mdr1) antisense oligonucleotides.

To overcome the problem of multidrug resistance, we investigated the effectiveness of phosphrothioate antisense oligonucleotides (MDR1-AS) in suppressing multidrug resistance gene (mdr1) expression in drug-resistant acute myelogenous leukemia (AML) blast cells and the K562 adriamycin-resistant cell line K562/ADM. The percentage of cells with the mdr1 gene product P-glycoprotein (P-gp) was decreased from 100% to 26% by 20 micromol/L MDR1-AS in the K562/ADM cells, and from 48.1% to 10.2% by 2.5 micromol/L MDR1-AS in the AML blast cells. Western blot analysis also showed a decrease in the amount of P-gp in the MDR1-AS-treated K562/ADM cells. This effect was specific to MDR1-AS, and not observed with sense or random control oligonucleotides. The expression of mdr1 mRNA in K562/ADM and AML blast cells treated with MDR1-AS was decreased compared with the random control. Intracellular rhodamine retention and [3H]daunorubicin also increased after antisense treatment. Chemosensitivity to daunorubicin increased in MDR1-AS-treated blast cells up to 5.9-fold in the K562/ADM cells and 3.0- to 6.4-fold in the AML blast cells. The expression of mdr1 mRNA derived from colony cells decreased in the MDR1-AS-treated groups. No inhibitory effect of the oligonucleotides on normal bone marrow progenitors was observed. These findings suggest that MDR1-AS is useful to overcome multidrug resistance in the treatment of leukemia.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Primary uterine T-cell lymphoma.

A uterine CD8-positive, HTLV-1-negative T-cell lymphoma associated with atypical endometrial hyperplasia was found in a 63-year-old Japanese woman. Primary T-cell lymphoma of the uterus has not been previously reported.

Blotting, Southern↗
PubMed1998

Induction of granulomas in interferon-gamma gene-disrupted mice by avirulent but not by virulent strains of Mycobacterium tuberculosis.

To gain a better understanding of the pathological role of interferon-gamma (IFN-gamma) in specific granuloma formation, IFN-gamma gene-deficient mice (BALB/c and C57BL/6) were produced. The IFN-gamma gene in embryonic stem (ES) cells was disrupted by inserting the beta-galactosidase gene (lacZ) and the neomycin resistance gene (neo) at the translation initiation site in exon 1 by homologous recombination. Six-week-old IFN-gamma-deficient and wild-type mice were inoculated with 10(3)-10(7) bacilli of various strains of Mycobacterium tuberculosis (Kurono, H37Rv, H37Ra and BCG Pasteur) through their tail veins. The mice were examined 7 weeks later for granuloma formation. The avirulent BCG Pasteur and H37Ra strains (10(3)-10(4) bacilli/ml) induced granulomas in the spleen, liver and lungs of IFN-gamma-deficient mice. The granulomas consisted of epithelioid macrophages and Langhans multinucleate giant cells, but lacked caseous necrosis. The virulent Kurono and H37Rv strains induced disseminated abscesses but not granulomas in various organs of IFN-gamma-deficient mice and Mac-3-positive macrophages were not detected in the abscess lesions. These results suggest that IFN-gamma may be primarily responsible for macrophage activation and that other factor(s) may be involved in the granuloma formation mechanism.

Animals↗
PubMed1998

Effect of dibromochloropropane (DBCP) on the hormone receptors of the male rat reproductive system.

The effects of dibromochloropropane (DBCP), a pesticide, on the male rat reproductive system were examined at morphological and hormonal expression levels. Changes of Leydig cells and seminiferous tubules were examined in rats treated with one subcutaneous (s.c.) injection of DBCP at doses of 10, 50, 75 and 100 mg/kg of body weight. The Leydig cells degenerated and decreased in number in those rats with an s.c. injection of DBCP at a dose of 50 mg/kg of body weight. However, these morphological changes were not significant in those rats that were treated with four separate s.c. injections of DBCP at 10 mg/kg of body weight. The expression of luteinizing hormone receptor mRNA, which is specifically expressed in Leydig cells, was decreased significantly in the DBCP-treated rats as compared with the normal-control rats. The expression of follicle-stimulating hormone receptor mRNA was decreased to a mild degree in DBCP-treated rats. At a dose of 75 mg/kg of body weight, seminiferous tubules as well as Leydig cells were severely damaged morphologically and at hormonal receptor expression levels. Multinucleated giant cells appeared at a dose of 75 mg/kg of body weight. All the rats died at a dose of 100 mg/kg of body weight. Our data indicate that DBCP had a cytotoxic effect on the male rat reproductive system in a dose-dependent manner.

Animals↗
PubMed1997

Lack of a point mutation of human DNA topoisomerase II in multidrug-resistant anaplastic thyroid carcinoma cell lines.

DNA topoisomerases are major defined targets for a large variety of clinically important anticancer agents, including etoposide, adriamycin, and mitoxantrone. Mutations at amino acids 439, 450 and 803 of DNA topoisomerase II were examined in multiple anticancer drug-resistant anaplastic thyroid carcinomas (ten cell lines and three cancerous tissues) by reverse transcriptase-polymerase chain reaction (RT-PCR) and subsequent DNA sequencing. No mutation was found in these cell lines and tissues, but mdr1, mrp and/or lrp mRNA were expressed to a varying degree, and there was no significant difference in DNA topoisomerase IIalpha content among the cell lines and tissues as evaluated by Western blotting. Our experimental data indicate that overexpression of multidrug resistance-related mRNA is sufficient to confer drug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Lung resistance protein (LRP) expression in human normal tissues in comparison with that of MDR1 and MRP.

MDR1 (P-glycoprotein), multidrug resistance-associated protein (MRP) and lung resistance protein (LRP) are associated with multidrug resistance in various cancer cells. It is known that P-glycoprotein and MRP are also expressed in several normal tissues. However, the exact location of LRP in normal tissues is still unclear. In order to obtain more insight into the physiological role of LRP, its expression in human normal tissues was examined by an immunohistochemical technique, using one monoclonal antibody, LRP-56. Reverse transcriptase-polymerase chain reaction (RT-PCR) was also utilized for several cell lines and fresh-frozen tissues. P-glycoprotein was found to be expressed in the kidney, adrenal, brain vessels, muscle, lung, pancreas, liver, intestine, placenta and testis. MRP was expressed in the kidney, adrenal, lung, pancreas, muscle, intestine, thyroid and prostate, and its distribution mostly overlapped with that of P-glycoprotein. Interestingly, MRP was not expressed in the liver. LRP at 110 kDa was expressed in the kidney, adrenal, heart, lung, muscle, thyroid, prostate, bone marrow and testis. These findings suggest that LRP as well as P-glycoprotein and MRP plays distinct roles in the physiology of various organs.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Expression of the MDR1 and MDR3 gene products in acute and chronic leukemias.

We performed immunocytochemistry to detect mdr1 and mdr3 P-glycoproteins (P-gps) in 81 patients with acute and chronic leukemia, using the mdr1 P-gp-specific monoclonal antibody (MoAb) MRK16, and the mdr3 P-gp-specific MDR3M. Immunoreactivity for the mdr1 gene product was positive in 27 out of 81 (33%) patients. Immunoreactivity with the anti-mdr3 P-gp MoAb was positive in 20 out of 81 (25%) patients. Of 54 patients with acute leukemia, 17 (31%) were positive for mdr1 P-gp and 8 (15%) for mdr3 P-gp. A high proportion (60%) of patients with chronic lymphocytic leukemia (CLL) were mdr3 P-gp positive. Of the patients with granular-lymphocyte proliferative disorder (GLPD), a chronic T-cell or natural killer cell leukemia, 8/17 (47%) were positive for mdr1 P-gp and 6/17 (35%) for mdr3 P-gp. Of 23 patients with chronic leukemia (CLL and GLPD), 10 (37%) were positive for mdr1 P-gp and 12 (44%) for mdr3 P-gp. To clarify the function of the mdr3 P-gp, we examined the intracellular rhodamine123 (Rh123) levels of mdr1 P-gp-negative and mdr3 P-gp-positive leukemic cells from patients with acute lymphocytic leukaemia, on the addition of 10 microM cyclosporin A (CyA). The addition of CyA led to significant increases in intracellular Rh123 levels in mdr1 P-gp-negative and mdr3 P-gp-positive leukemic cells. Results of the assay for dye efflux suggested that the mdr3 P-gp has a role in drug resistance, and functional drug-efflux capacity. In 31 acute leukemia patients at initial diagnosis, mdr1 or mdr3 P-gp expression correlated significantly to an outcome of complete remission (CR). In 54 acute leukemia patients, exposure to precytotoxic agents correlated significantly to expression, with a significant higher number of patients mdr1 or mdr3 P-gp positive than negative. In the 54 patients with acute leukemia, mdr1 P-gp expression correlated to mdr3 P-gp expression significantly (p=0.0007). In the 27 patients with chronic leukemia (CLL and GLPD), mdr1 and mdr3 P-gp expression did not correlate to exposure to precytotoxic agents, nor did mdr1 P-gp expression correlate to mdr3 P-gp expression. It may be speculated that precytotoxic agents induced mdr1 and mdr3 P-gp expression in acute leukemia; however, in chronic leukemia, both P-gps were expressed independently of exposure to precytotoxic agents.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed1997

Cytokeratin expression in normal human thymus at different ages.

Subsets of thymic epithelial cells were examined immunohistochemically to determine whether or not their phenotypes change during thymic growth and at early involution in terms of cytokeratin (CK) expression. Five monoclonal antibodies specific for CK4, CK8, CK13, CK18 and CK19 were used and applied to 16 neonatal, three infantile and one adult thymus specimen, which had been obtained at autopsy, that were normal macroscopically and microscopically. CK4, CK8, CK13, CK18 and CK19 were expressed simultaneously in the cortex, medulla and subcapsular area with the exception of CK4, which showed expression on the adult thymus. Light and electron microscopy showed that CK8 and CK19 expression was overlapped. Thus, it was thought that CK8 and CK19 formed complexes in the cytoplasm of thymic epithelial cells. The immunoreactivity to CK4, CK13 and CK18 were attenuated or disappeared in the subcapsular area during the early involution stage. Interestingly, two patterns of CK18 expression were observed in the neonatal and infantile thymus tissues, which indicated that the thymic microenvironment was changeable even under normal conditions.

Adult↗
PubMed1997

Anti-proliferative effect of toremifene and tamoxifen on estrogen receptor-lacking anaplastic thyroid carcinoma cell lines.

The antitumor effects of toremifene were studied in vitro using 10 anaplastic thyroid carcinoma cell lines and were compared with those of tamoxifen. The antitumor effect of toremifene was dose-dependent and the IC50 values for these cell lines ranged 20.1-58.5 microM. Although the cell lines expressed multidrug resistance gene mRNA, multidrug resistance-associated protein gene mRNA and insulin-like growth factor-1 (IGF-1) receptor mRNA to various degrees, nine of them lacked estrogen receptor expression as evaluated by immunocytochemistry. These data indicate that toremifene, as well as tamoxifen, is cytolytic at relatively high doses for multidrug-resistant anaplastic thyroid carcinoma cell lines.

Antineoplastic Agents, Hormonal↗