Biomedical subjects

Minoru Fukuda

Publications and source records attributed to Minoru Fukuda.

At least 55 records · Page 3Linked to original sources

PubMed2005

Electron microscopic observation of the invasion process of Cryptosporidium parvum in severe combined immunodeficiency mice.

Cryptosporidium parvum mainly invades the intestinal epithelium and causes watery diarrhea in humans and calves. However, the invasion process has not yet been clarified. In the present study, the invasion process of C. parvum in severe combined immunodeficiency (SCID) mice was examined. Infected mice were necropsied; the ilea were double-fixed routinely and observed by scanning and transmission electron microscopy. In addition, the microvillus membrane was observed by ruthenium red staining. Scanning electron micrographs showed elongation of the microvilli at the periphery of the parasite. The microvilli were shown to be along the surface of the parasite in higher magnification. Transmission electron microscopy confirmed that the invading parasites were located among microvilli. Parasites existed in the parasitophorous vacuole formed by the microvillus membrane. The parasite pellicle attached to the host cell membrane at the bottom of the parasite, and then the pellicle and host cell membrane became unclear. Subsequently, the pellicle became complicated and formed a feeder organelle. In addition, invasion of the parasite was not observed in either a microvillus or the cytoplasm of the host cell. Therefore, C. parvum invades among microvilli, is covered with membranes derived from numerous microvilli, and develops within the host cell.

Animals↗

PubMed2005

Self-limiting pneumonia due to Chlamydia pneumoniae.

A case of self-limiting pneumonia due to Chlamydia pneumoniae is described. A 39-year-old male visited our hospital complaining of a persistent cough. No antibiotics were administered to this patient because of the absence of fever and a mild positive inflammatory response, but an infiltrate on a chest radiograph improved. Finally, a diagnosis of C. pneumoniae pneumonia was made by seroconversion of the C. pneumoniae-specific antibody and detection of the C. pneumoniae gene in bronchoalveolar lavage fluid. Self-limiting C. pneumoniae pneumonia is rarely encountered, although self-limiting upper respiratory tract infections due to C. pneumoniae are common. Thus, most self-limiting C. pneumoniae pneumonia may be missed when symptoms are minimal.

Adult↗

PubMed2005

[A case of pulmonary adenosquamous cell carcinoma with thin-wall cavities].

A 68-year-old man was admitted to our hospital because of continuous cough of three months duration and for investigation of a thin-wall cavitary lesion (> 3 cm) in the right upper lung field. Thin-wall cavity (40 x 35 mm) with notch and spiculation was observed in the right S2 on chest CT. A histological diagnosis of pulmonary adenocarcinoma was obtained by bronchoscopic examination, and he was transferred to the Department of Thoracic Surgery where a right upper lobectomy was performed. Subsequently, cavity formation (45 x 40 x 35 mm) was disclosed in the right S2. Most of the surrounding cavity consisted of the components of a well differentiated squamous cell carcinoma with keratinization and slightly different components of a poorly differentiated adenocarcinoma with mucous production. The final diagnosis was pulmonary adenosquamous cell carcinoma and the postoperative histological classification was T2N2M0 (Stage 3A) because of metastasis to the lymph nodes (#4 and #11). A communicating bronchus was histologically identified and we presumed that the thin-wall cavity developed by a check valve mechanism. Although squamous cell carcinoma has been reported to be the histological type, tending to form thin-wall cavities among patients with lung cancer reported to be squamous cell carcinoma, recently an increasing number of such cavities have been reported among patients with pulmonary adenocarcinoma. Herein, we have reported a rare case of histological diagnosis of pulmonary adenosquamous cell carcinoma with cavity formation.

Aged↗

PubMed2005

[Anticancer drugs and ABC transporters].

Anticancer drugs interact directly with their molecular targets in cancer cells for effective cancer chemotherapy. The direct interaction between drug and cancer cell depends on the pharmacokinetics, which consists of absorption, distribution, metabolism, and excretion phases. In the excretion phase, ATP-binding cassette (ABC) transporters are the most important proteins in cell membranes. The ABC transporters export drugs out of cells by ATP-dependent energy, leading to drug resistance with reduced concentrations of intracellular drugs. In addition, the transporters sequestrate intracellular drugs into membrane vesicles in cytoplasm, also resulting in drug resistance. On the other hand, they are also involved in drug absorption. To date, 48 ABC genes have been isolated and classified into the seven groups of ABCA to ABCG. Among them, P-glycoprotein/ABCB 1, MRP 1/ ABCC 1, MRP 2/ABCC 2, MRP 3/ABCC 3, and BCRP/ABCG 2 strongly confer anticancer drug resistance, and they have different substrate drugs. Interestingly, recent molecular-targeted drugs, such as imatinib and gefitinib, were very recently found to be substrates for P-glycoprotein and/or BCRP. Additionally, polymorphism of ABC genes affects pharmacokinetics, drug effectiveness, and adverse events. Thus, ABC transporters are clinically important molecules, and much information is needed in the clinic.

ATP-Binding Cassette Transporters↗

PubMed2005

[Current status of patients discharging Mycobacterium tuberculosis after admission to Kawasaki Medical School Hospital].

OBJECTIVES: To investigate the current status of patients with tuberculosis in Kawasaki Medical School Hospital which has closed tuberculosis isolation ward and review the nosocomial tuberculosis infection control. MATERIALS AND METHODS: Clinical analysis was performed and nosocomial tuberculosis infection control were examined in 39 patients from whom Mycobacterium tuberculosis was isolated in Kawasaki Medical School Hospital between January 2001 and August 2004. RESULTS: Mycobacterium tuberculosis was isolated in 16 patients in the Respiratory Division of the Department of Internal Medicine and in 23 patients in non-respiratory divisions. Thirty-four patients had underlying diseases and of these 14 patients had malignant diseases. The final diagnosis was pulmonary tuberculosis in 23 patients, and pulmonary tuberculosis was suspected in 13 patients on admission. The remaining 10 patients were treated for pneumonia on admission. M. tuberculosis was isolated most frequently from the sputum in 21 patients and 13 of them were smear positive who needs nosocomial infection control measures. Health examinations of the families and hospital staff in contact with these 13 patients with smear positive sputum after the diagnosis of tuberculosis revealed no active case of tuberculosis. CONCLUSIONS: This study has shown that there are many cases with an atypical pattern for pulmonary tuberculosis among patients with underlying diseases, especially malignant diseases. There are still many tuberculosis patients who were diagnosed pneumonia after the admission and were administered antibiotics. We believe that more educational guidance regarding tuberculosis is needed for the hospital staff.

Adolescent↗

PubMed2005

[Oral administration of arsenic trioxide induced molecular remission in relapsed acute promyelocytic leukemia].

I report on a 21-year-old man with acute promyelocytic leukemia (APL) which relapsed after a therapeutic regimen consisting of tretinoin, daunorubicin, enocitabine, mitoxantrone, and cytarabine. The patient also had severe mental retardation caused by a congenital central nervous system malformation. Administration of arsenic trioxide (As2O3) is indicated for patients with APL, however, daily intravenous infusion of As2O3 presented problems because of the patient's violent resistance to venous access. Accordingly, 10mg of an oral solution of As2O3 was given once daily for 70 days. No adverse events were observed with the exception of transient hyperleukocytosis and fever. The patient achieved molecular remission 103 days after the start of oral As2O3, and remains in remission after an additional 2 courses of oral As2O3 as consolidation chemotherapy. Oral As2O3 may be useful in the treatment of relapsed APL as an alternative to intravenous As2O3.

Administration, Oral↗

PubMed2004

Induction of peripheral lymph node addressin in human gastric mucosa infected by Helicobacter pylori.

Helicobacter pylori infects over half the world's population and is a leading cause of peptic ulcer and gastric cancer. H. pylori infection results in chronic inflammation of the gastric mucosa, and progression of chronic inflammation leads to glandular atrophy and intestinal metaplasia. However, how this chronic inflammation is induced or maintained is not well known. Here, we show that chronic inflammation caused by H. pylori infection is highly correlated with de novo synthesis of peripheral lymph node addressin (PNAd) presented on high-endothelial venule (HEV)-like vessels. The number of HEV-like vessels dramatically increases as chronic inflammation progresses. We found that the PNAd is bound by L-selectin.IgM chimeric protein, and decorated by NCC-ST-439 antibody, which is suggested to recognize both nonsulfated and 6-sulfated sialyl Lewis X on core 2 branched O-glycans, and MECA-79 antibody, which reacts with 6-sulfo N-acetyllactosamine on extended core 1 O-glycans. These results indicate that PNAd on HEV-like vessels present in the gastric mucosa subsequent to H. pylori infection is similar to those on HEVs present in the secondary lymphoid organs, which are essential for lymphocyte circulation. Moreover, eradication of H. pylori is associated with the disappearance of HEV-like vessels in the gastric mucosa. By contrast, very few PNAd were found in the gastric mucosa of patients with chemical gastritis caused by nonsteroidal antiinflammatory drugs. These results strongly suggest that PNAd in HEV-like vessels plays a critical role in lymphocyte recruitment during chronic inflammation induced by H. pylori infection.

Animals↗

PubMed2004

HMMC-1: a humanized monoclonal antibody with therapeutic potential against Müllerian duct-related carcinomas.

PURPOSE: The purpose of this research was to generate a human monoclonal antibody specific to gynecological cancers and to evaluate such an antibody as therapy for gynecological cancers. EXPERIMENTAL DESIGN: Transchromosomal KM mice were immunized with the human uterine endometrial cancer cell line SNG-S. Hybridomas were constructed between spleen cells from KM mice and mouse myeloma cells. Reactivity of the antibody was evaluated by immunohistochemistry of pathological specimens of gynecological cancers. Cytotoxicity of HMMC-1 against SNG-S cells was tested by in vitro cytotoxicity assays. The epitope of HMMC-1 was determined by transfection with a panel of glycosyltransferase cDNAs and by inhibition assays with chemically synthesized oligosaccharides. RESULTS: HMMC-1 is a human IgM monoclonal antibody that reacts positively with mullerian duct-related carcinomas with positive rates of 54.6% against uterine endometrial adenocarcinoma, 76.9% against uterine cervical adenocarcinoma, and 75.0% against epithelial ovarian cancer. HMMC-1 does not react with normal endometrium at proliferative or secretory phases, normal uterine cervix, or normal and malignant tissue from other organs, whereas it reacts weakly with the epithelium of the gall bladder and the collecting duct of the kidney. HMMC-1 exhibits antigen-dependent and complement-mediated cytotoxicity. Upon cotransfection with cDNAs encoding two glycosyltransferases required for fucosylated extended core 1 O-glycan, mammalian cells express HMMC-1 antigen. Finally, binding of HMMC-1 to SNG-S cells is inhibited by synthetic Fucalpha1-->2Galbeta1-->4GlcNAcbeta1-->3Galbeta1-->3GalNAcalpha1-octyl. CONCLUSIONS: These results indicate that HMMC-1 specifically recognizes a novel O-glycan structure. The unique specificity and cytotoxicity of HMMC-1 strongly suggest a therapeutic potential of this antibody.

Animals↗

PubMed2004

Human P-selectin glycoprotein ligand-1 (PSGL-1) interacts with the skin-associated chemokine CCL27 via sulfated tyrosines at the PSGL-1 amino terminus.

P-selectin glycoprotein ligand-1 (PSGL-1), a sialomucin expressed on leukocytes, is a major ligand for P-selectin and mediates leukocyte rolling on the endothelium. Here we show that human PSGL-1 interacts with CCL27 (CTACK/ILC/ESkine), a skin-associated chemokine that attracts skin-homing T lymphocytes. A recombinant soluble form of PSGL-1 (rPSGL-Ig) preferentially bound CCL27 among several chemokines tested. This interaction was abrogated by arylsulfatase treatment of rPSGL-Ig, suggesting that sulfated tyrosines play a critical role. In contrast, removal of either N-glycans or O-glycans by glycosidase treatment of rPSGL-Ig did not affect the interaction. The binding of CCL27 to a recombinant PSGL-1 synthesized in the presence of a sulfation inhibitor was lower than that produced in normal medium. Moreover, mutation of the tyrosines at the amino terminus of PSGL-1 to phenylalanine abolished the binding, further supporting the role of sulfated tyrosines in the CCL27-PSGL-1 interaction. Functionally, rPSGL-Ig reduced the chemotaxis of L1.2 cells expressing CCR10, the receptor for CCL27. In addition, the expression of human PSGL-1 on CCR10-expressing L1.2 cells resulted in reduced chemotaxis to CCL27. These findings suggest a role for PSGL-1 in regulating chemokine-mediated responses, in addition to its role as a selectin ligand.

Amino Acid Sequence↗

PubMed2004

Phase II study of irinotecan combined with carboplatin in previously untreated non-small-cell lung cancer.

PURPOSE: Irinotecan, a topoisomerase I inhibitor, is an effective agent for non-small-cell lung cancer (NSCLC). To determine the efficacy and toxicity of irinotecan and carboplatin, we conducted a phase II study in 61 patients with advanced NSCLC. METHODS: Every 4 weeks, the patients received irinotecan 50 mg/m2 (days 1, 8 and 15) and carboplatin (day 1) with a target AUC of 5 mg min/ml using the Chatelut formula. RESULTS: All patients were evaluable for toxicity, and of 59 patients evaluable for response, 20 achieved a partial response and 26 showed no change. The overall response rate was 34% (95% confidence interval 23-48%). Grade 3 or 4 anemia, leukopenia, neutropenia, thrombocytopenia and diarrhea occurred in 32%, 32%, 60%, 25%, and 7%, respectively. The median survival time and 1-year, and 2-year survival rates were 10.0 months, 37.6%, and 15.2%, respectively. CONCLUSIONS: Irinotecan with carboplatin is effective for advanced NSCLC and safe.

Adult↗

PubMed2004

Natural antibiotic function of a human gastric mucin against Helicobacter pylori infection.

Helicobacter pylori infects the stomachs of nearly a half the human population, yet most infected individuals remain asymptomatic, which suggests that there is a host defense against this bacterium. Because H. pylori is rarely found in deeper portions of the gastric mucosa, where O-glycans are expressed that have terminal alpha1,4-linked N-acetylglucosamine, we tested whether these O-glycans might affect H. pylori growth. Here, we report that these O-glycans have antimicrobial activity against H. pylori, inhibiting its biosynthesis of cholesteryl-alpha-D-glucopyranoside, a major cell wall component. Thus, the unique O-glycans in gastric mucin appeared to function as a natural antibiotic, protecting the host from H. pylori infection.

Acetylglucosamine↗

PubMed2004

Endomucin, a sialomucin expressed in high endothelial venules, supports L-selectin-mediated rolling.

Lymphocyte homing to lymph nodes is regulated by transient but specific interactions between lymphocytes and high endothelial venules (HEVs), the initial phase of which is mainly governed by the leukocyte adhesion molecule L-selectin, which recognizes sulfated and sialylated O-linked oligosaccharides displayed on sialomucin core proteins. One of the sialomucin proteins, endomucin, is predominantly expressed in vascular endothelial cells of a variety of tissues including the HEVs of lymph nodes; however, whether it functions as a ligand for L-selectin remains to be formally proven. Here we show that the endomucin splice isoform a is predominantly expressed in PNAd+ HEVs and MAdCAM-1+ HEVs, as seen in non-HEV-type vascular endothelial cells. Using affinity purification with soluble L-selectin, we found that HEV endomucin is specifically modified with L-selectin-reactive oligosaccharides and can bind L-selectin as well as an HEV-specific mAb, MECA-79. Our results also indicated that a 90-100 kDa endomucin species is preferentially decorated with L-selectin-reactive sugar chains, whereas an 80 kDa species represents conventional forms expressed in non-HEV-type vascular endothelial cells in lymph nodes. Furthermore, a CHO cell line expressing endomucin together with a specific combination of carbohydrate-modifying enzymes [core-2 beta-1,6-N-acetylglucosaminyltransferase (C2GnT), alpha-1,3-fucosyltransferase VII (FucTVII) and L-selectin ligand sulfotransferase (LSST)] showed L-selectin-dependent rolling under flow conditions in vitro. These results suggest that when endomucin is appropriately modified by a specific set of glycosyltransferases and a sulfotransferase, it can function as a ligand for L-selectin, and that the endomucin expressed in HEVs may represent another sialomucin ligand for L-selectin.

Animals↗

PubMed2004

Sialyltransferase ST8Sia-II assembles a subset of polysialic acid that directs hippocampal axonal targeting and promotes fear behavior.

Polysialic acid (PSA) is a post-translational protein modification that is widely expressed among neural cell types during development. Found predominantly on the neural cell adhesion molecule (NCAM), PSA becomes restricted to regions of neurogenesis and neuroplasticity in the adult. In the mammalian genome, two polysialyltransferases termed ST8Sia-II and ST8Sia-IV have been hypothesized to be responsible for the production of PSA in vivo. Approaches to discover PSA function have involved the application of endoneuraminidase-N to remove PSA and genetic manipulations in the mouse to deplete either NCAM or ST8Sia-IV. Here we report the production and characterization of mice deficient in the ST8Sia-II polysialyltransferase. We observed alterations in brain PSA expression unlike those observed in mice lacking ST8Sia-IV. This included a PSA deficit in regions of neurogenesis but without changes in the frequency of mitotic neural progenitor cells. In further contrast with ST8Sia-IV deficiency, loss of ST8Sia-II did not impair hippocampal synaptic plasticity but instead resulted in the misguidance of infrapyramidal mossy fibers and the formation of ectopic synapses in the hippocampus. Consistent with studies of animal models bearing these morphological changes, ST8Sia-II-deficient mice exhibited higher exploratory drive and reduced behavioral responses to Pavlovian fear conditioning. PSA produced by the ST8Sia-II polysialyltransferase modifies memory and behavior processes that are distinct from the neural roles reported for ST8Sia-IV. This genetic partitioning of PSA formation engenders discrete neurological processes and reveals that this post-translational modification forms the predominant basis for the multiple functions attributed to the NCAM glycoprotein.

Animals↗

PubMed2004

Molecular dissection of the ST8Sia IV polysialyltransferase. Distinct domains are required for neural cell adhesion molecule recognition and polysialylation.

Polysialic acid, a homopolymer of alpha2,8-linked sialic acid expressed on the neural cell adhesion molecule (NCAM), is thought to play critical roles in neural development. Two highly homologous polysialyltransferases, ST8Sia II and ST8Sia IV, which belong to the sialyltransferase gene family, synthesize polysialic acid on NCAM. By contrast, ST8Sia III, which is moderately homologous to ST8Sia II and ST8Sia IV, adds oligosialic acid to itself but very inefficiently to NCAM. Here, we report domains of polysialyltransferases required for NCAM recognition and polysialylation by generating chimeric enzymes between ST8Sia IV and ST8Sia III or ST8Sia II. We first determined the catalytic domain of ST8Sia IV by deletion mutants. To identify domains responsible for NCAM polysialylation, different segments of the ST8Sia IV catalytic domain, identified by the deletion experiments, were replaced with corresponding segments of ST8Sia II and ST8Sia III. We found that larger polysialic acid was formed on the enzymes themselves (autopolysialylation) when chimeric enzymes contained the carboxyl-terminal region of ST8Sia IV. However, chimeric enzymes that contain only the carboxyl-terminal segment of ST8Sia IV and the amino-terminal segment of ST8Sia III showed very weak activity toward NCAM, even though they had strong activity in polysialylating themselves. In fact, chimeric enzymes containing the amino-terminal portion of ST8Sia IV fused to downstream sequences of ST8Sia III inhibited NCAM polysialylation in vitro, although they did not polysialylate NCAM. These results suggest that in polysialyltransferases the NCAM recognition domain is distinct from the polysialylation domain and that some chimeric enzymes may act as a dominant negative enzyme for NCAM polysialylation.

Animals↗

PubMed2004

Carbohydrate structure and differential binding of prostate specific antigen to Maackia amurensis lectin between prostate cancer and benign prostate hypertrophy.

Serum prostate-specific antigen (PSA) assay is widely used for detection of prostate cancer. Because PSA is also synthesized from normal prostate, false positive diagnosis cannot be avoided by the conventional serum PSA test. To apply the cancer-associated carbohydrate alteration to the improvement of PSA assay, we first elucidated the structures of PSA purified from human seminal fluid. The predominant core structure of N-glycans of seminal fluid PSA was a complex type biantennary oligosaccharide and was consistent with the structure reported previously. However, we found the sialic acid alpha2-3 galactose linkage as an additional terminal carbohydrate structure on seminal fluid PSA. We then analyzed the carbohydrate moiety of serum PSA from the patients with prostate cancer and benign prostate hypertrophy using lectin affinity chromatography. Lectin binding was assessed by lectin affinity column chromatography followed by determining the amount of total and free PSA. Concanavalin A, Lens culinaris, Aleuria aurantia, Sambucus nigra, and Maackia amurensis lectins were tested for their binding to the carbohydrates on PSA. Among the lectins examined, the M. amurensis agglutinin-bound fraction of free serum PSA is increased in prostate cancer patients compared to benign prostate hypertrophy patients. The binding of PSA to M. amurensis agglutinin, which recognizes alpha2,3-linked sialic acid, was also confirmed by surface plasmon resonance analysis. These results suggest that the differential binding of free serum PSA to M. amurensis agglutinin lectin between prostate cancer and benign prostate hypertrophy could be a potential measure for diagnosis of prostate cancer.

Carbohydrates↗

PubMed2004

A mitochondrial protein, Bit1, mediates apoptosis regulated by integrins and Groucho/TLE corepressors.

A delicate balance of signals regulates cell survival. One set of these signals is derived from integrin-mediated cell adhesion to the extracellular matrix (ECM). Loss of cell attachment to the ECM causes apoptosis, a process known as anoikis. In searching for proteins involved in cell adhesion-dependent regulation of anoikis, we identified Bit1, a mitochondrial protein that is released into the cytoplasm during apoptosis. Cytoplasmic Bit1 forms a complex with AES, a small Groucho/transducin-like enhancer of split (TLE) protein, and induces cell death with characteristics of caspase-independent apoptosis. Cell attachment to fibronectin counteracts the apoptotic effect of Bit1 and AES. Increasing Bit1 expression enhances anoikis, while suppressing the expression reduces it. Thus, we have elucidated an integrin-controlled pathway that is, at least in part, responsible for the cell survival effects of cell-ECM interactions.

Animals↗

PubMed2004

High-risk populations for nasal carriage of methicillin-resistant Staphylococcus aureus.

To determine the population at high risk of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) on hospital patients admission, a nasal swab was taken from the following patients: (1) those aged 70 years or over (age >or= 70), (2) non ambulatory receiving regular home visits by nurses and physicians (visiting), (3) residents of nursing homes (nursing home), (4) patients from other hospitals (another Hp), and (5) those scheduled for surgery (presurgery). Between March and July 2000, a total of 412 patients were admitted and 136 were enrolled. MRSA was isolated from 12 (8.8%) patients. The number of patients positive for MRSA in the five groups, age >or=70, visiting, nursing home, another Hp, and presurgery, were 3 of 68, 3 of 21, 2 of 3, 3 of 9, and 1 of 35, respectively. Multivariate analysis revealed that living in a nursing home [odds ratio (OR) = 32.82, P = 0.010] or coming from another hospital (OR = 14.55, P = 0.0043) were high risk factors with for nasal carriage of MRSA. Furthermore, patients' ages were further divided into three categories, or=90, and regarded as independent high risk factors (OR = 3.08, P = 0.043). The results were that advanced living in a age (>or=80, >or=90), living in a nursing home or coming from another hospital are high risk factors of nasal carriage of MRSA on hospital admission.

Adult↗

PubMed2004

Migrating and myelinating potential of neural precursors engineered to overexpress PSA-NCAM.

Polysialic acid (PSA) on NCAM is an important modulator of cell-cell interactions during development and regeneration. Here we investigated whether PSA overexpression influences neural cell migration and myelination. We stably expressed a GFP-tagged polysialytransferase, PSTGFP, in mouse neurospheres and induced prolonged PSA synthesis. Using a chick xenograft assay for migration, we show that PSA can instruct precursor migration along the ventral pathway. PSA persistence did not change neural precursor multipotentiality in vitro but induced a delay in oligodendrocyte differentiation. PSTGFP+ precursors showed widespread engraftment in shiverer brain, closely similar to that observed with control precursors expressing a fluorescent protein. Initially, myelination by oligodendrocytes was delayed but, eventually, down-regulation of PSTGFP occurred, allowing myelination to proceed. Thus down-regulation of polysialyltransferases takes place even in cells where its RNA is under the control of a heterologous promoter and engineering PSA overexpression in neural precursors does not cause irreversible unphysiological effects.

3T3 Cells↗