Search PubMed⌕ Search

Biomedical subjects

K Nakata

Publications and source records attributed to K Nakata.

At least 163 records · Page 9Linked to original sources
PubMed1999

Bronchiolitis in Kartagener's syndrome.

The association of diffuse bronchiolitis in patients with Kartagener's syndrome (KS) has not been reported previously. The aim of this study was to present the morphological characteristics of bronchiolitis in patients with KS. Eight patients (four males, four females; mean age 37.9+/-18.7 yrs), clinically diagnosed as KS with the classical triad of chronic pansinusitis, bronchiectasis and situs in versus with dextrocardia, were evaluated. Routine chest radiography showed bronchiectasis and dextrocardia in all patients. Chest computed tomography (CT) showed diffuse centrilobular small nodules up to 2 mm in diameter throughout both lungs in six out of eight patients. Pulmonary function tests revealed marked obstructive impairment in all patients (forced expiratory volume in one second 57.0+/-11.3%, residual volume/total lung capacity 45.+/-12.7%, maximum midexpiratory flow 0.92+/-0.72 L x s(-1), forced vital capacity 74.1+/-12.2% (all mean +/- SD)). The examination of cilial movement of the bronchus revealed immotility in all of the five patients examined. The ultrastructure showed ciliary dynein arm defects in all patients. Histopathological examination of lung specimens obtained at autopsy or by video-assisted thoracoscopic surgery showed obliterative thickening of the walls of the membranous bronchioli with infiltration of lymphocytes, plasma cells and neutrophils, but most of the distal respiratory bronchioli were spared and alveolar spaces were overinflated. Pathologically, the diffuse centrilobular small nodules on the chest CT mainly corresponded to membranous bronchiolitis. This is the first report demonstrating that the association of diffuse bronchiolitis might be one of the characteristic features of the lung in Kartagener's syndrome.

Adolescent↗
PubMed1999

Phase II study of area under the plasma-concentration-versus-time curve-based carboplatin plus standard-dose intravenous etoposide in elderly patients with small-cell lung cancer.

PURPOSE: The target area under the plasma-concentration-versus-time curve (AUC)-based dosing of carboplatin using Calvert's formula is expected to result in more acceptable toxicity and greater efficacy in elderly patients with small-cell lung cancer (SCLC) than the body surface area-based dosing strategy. This phase II study was designed to determine the toxicity and efficacy of carboplatin based on Calvert's formula plus the standard dose of intravenous etoposide for elderly patients with SCLC. PATIENTS AND METHODS: Carboplatin, dosed to a target AUC of 5 x (24-hour creatinine clearance + 25), was given intravenously on day 1 and etoposide 100 mg/m(2) was given intravenously on days 1, 2, and 3. Patients aged >/= 70 years old with a performance status of 0 to 2 were eligible. RESULTS: Thirty-six patients were enrolled onto the study. The patient characteristics were as follows: median age, 73 years; limited disease (LD), 16 patients; and extensive disease (ED), 20 patients. Grades 3 and 4 leukopenia occurred in 57% and 3% of patients, and grades 3 and 4 thrombocytopenia occurred in 40% and 11% of patients, respectively. There was one treatment-related death due to hemoptysis. Other toxicities were relatively mild. There were two complete responses and 25 partial responses, for a response rate of 75%. The median survival time was 10.8 months (LD, 11.6 months; ED, 10.1 months), and the 1-year survival rate was 47%. CONCLUSION: This carboplatin/etoposide combination chemotherapy is an active and relatively nontoxic regimen in elderly patients with SCLC, which suggests that the combination may be suitable for randomized controlled trials.

Aged↗
PubMed1999

Production of an extracellular polysaccharide bioflocculant by Klebsiella pneumoniae.

Klebsiella pneumoniae H12 produced a newly identified extracellular polysaccharide in an ethanol medium with a yield of 3.0 g/l. The molar composition of the polysaccharide was 56.04% galactose, 25.92% glucose, 10.92% galacturonic acid, 3.71% mannose, and 3.37% glucuronic acid. The addition of 0.5%-1.5% NaCl increased production. The polysaccharide flocculated with kaolin clay in suspension at the concentration of 1 ppm in a 300-ppm solution of CaCl2. Almost all bacterial species cells aggregated in the polysaccharide solution. The ability to flocculate with kaolin clay changed with the pH and with the concentrations of coexisting cation and anion species. The polysaccharide flocculant may participate in in vivo bacterial aggregation or adherence to host organisms.

Ethanol↗
PubMed1999

Promotion of antibiotic production by high ethanol, high NaCl concentration, or heat shock in Pseudomonas fluorescens S272.

A stress imposed by a continuous feed of high ethanol, high NaCl concentration, or a high temperature shock increased antibiotic production by several times in Pseudomonas fluorescens S272. A tentative bioassay showed that the stress caused about 40-fold elevation in the autoinducer activity. Addition of synthetic autoinducers, N-(3-oxododecanoyl)-L-homoserine lactone or N-(3-oxohexanoyl)-L-homoserine lactone at a concentration of more than 100 micrograms/l to a non-stressed culture also increased the antibiotic production by several times. These results suggested that the antibiotic production in P. fluorescens S272 was regulated by N-acyl-homoserine lactone and the promotive effect by stress occurred through any function that increased the autoinducer production.

4-Butyrolactone↗
PubMed1999

Serotypes and virulence factors of Escherichia coli strains isolated from dogs and cats.

E. coli strains isolated from urine of dogs and cats with urinary tract infections (UTI) and from feces of healthy one's were serotyped, and the serotypes were correlated with uropathogenic virulence factors. The most prevalent O-serotypes, O4 and O6, were isolated from dogs and cats with UTI. In contrast, O11 and O102 strains were the most frequently found from feces of healthy dogs and cats. Most of type O4 and O6 strains possessed such virulence factors as pil, pap, sfa, hly, and cnf1, while most type O11 and O102 strains pil only or pil and aer. All strains of type O75 possessed afaI and aer. K1 antigen was negative in all strains obtained from UTI.

Animals↗
PubMed1999

Successful treatment of refractory bronchorrhea by inhaled indomethacin in two patients with bronchioloalveolar carcinoma.

Bronchorrhea in patients with bronchioloalveolar carcinoma is not uncommon. However, to our knowledge, an effective treatment for bronchorrhea in these patients has not been established. Recently, we have confirmed the efficacy of inhaled indomethacin in severe refractory bronchorrhea in comparison to that of other medications in two patients with bronchioloalveolar carcinoma. Despite the administration of a macrolide and corticosteroid, sputum volume increased to 700 mL/d in case 1 and to 200 mL/d in case 2 and hypoxemia and dyspnea deteriorated. Within a few days after the initiation of treatment with inhaled nebulized indomethacin (75 mg/d), sputum volume started to decrease and was controlled to < 100 mL/d, associated with alleviation of dyspnea and hypoxemia. To our knowledge, this is the first report of successfully treated refractory bronchorrhea associated with bronchioloalveolar carcinoma by inhaled indomethacin, resulting in markedly reduced sputum volume, improved quality of life, and prolonged survival.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1999

Prevalence and characterization of hepatitis C virus in hemodialysis patients.

OBJECT: Chronic hepatitis C virus (HCV) infection is common in hemodialysis (HD) patients. In the present study, the prevalence and properties of HCV in HD patients were analyzed. METHODS AND RESULTS: Of 125 HD patients, 34 (27%) were positive for antibody to HCV, and HCV-RNA was detected in 23 (68%) of the 34 patients using reverse transcription polymerase chain reaction. The HCV-RNA sequence analysis did not identify the alterations specific to HD patients with HCV, although one patient had a variant virus containing the deletion of the core gene sequence. When serial changes in the levels of HCV-RNA were evaluated in 15 patients by a branched DNA assay, the values decreased immediately after HD procedure, but returned to the baseline values 2 days after the procedure. CONCLUSION: These results indicate that HCV in HD patients is replication-competent, although a transient reduction in the levels of HCV-RNA occurs during HD.

Adult↗
PubMed1999

Epidermal growth factor-mediated cell maturation and apoptosis in RGM-1 rat gastric mucosal cells.

Epidermal growth factor (EGF) and heparin-binding EGF-like growth factor (HB-EGF) exert their activities through the same cell surface receptor. In the present study, the role of EGF in cell kinetics of rat gastric epithelial cell line, RGM-1, in which HB-EGF is known to function in an autocrine fashion, was investigated. EGF stimulated the mucus glycoprotein synthesis which is characterized with cell maturation, but competed with HB-EGF for cell proliferation. By flow cytometric analysis, EGF inhibited G2/M transition by 48 h after stimulation and induced apoptosis manifested by hypodiploid DNA by 72 h after stimulation. Consistent with this, DNA ladder formation together with the histone-associated DNA fragments was found in EGF-treated cells. These results indicate that EGF and HB-EGF possess different functions in RGM-1 cells and that EGF acts as a mediator of both cell maturation and apoptosis in these cells.

Animals↗
PubMed1999

Detection of hepatitis B virus X-region DNA in liver tissue from patients with hepatitis C virus-associated cirrhosis who subsequently developed hepatocellular carcinoma.

The risk of hepatocellular carcinoma (HCC) in patients chronically infected by hepatitis C virus (HCV) is relatively higher in Japan than in Western countries. The presence of hepatitis B virus X (HBX)-DNA in the liver tissue samples obtained on enrollment from 69 patients with HCV-associated cirrhosis who were subsequently followed in our hospital was analyzed by polymerase chain reaction (PCR). During the follow-up period of 5.7+/-3.2 years (mean +/- SD), 52 (75%) of 69 patients developed HCC. The PCR analysis indicated that the HBX-DNA sequence was detected in 25 (48%) of 52 patients who developed HCC during follow-up, but in only 3 (18%) of 17 patients who did not (P<0.05). These results suggest that HBX, a hepatitis B viral product relevant to hepatocarcinogenesis, is involved in development of HCC in some patients chronically infected by HCV in Japan.

Adult↗
PubMed1999

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1997)].

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and analyzed some characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In these 17 institutions around the entire Japan, 512 strains of presumably etiological bacteria were isolated mainly from the sputa of 440 patients with lower respiratory tract infections during the period from October in 1997 to September in 1998. MICs of various antibacterial agents and antibiotics were determined against 100 strains of Staphylococcus aureus, 81 strains of Streptococcus pneumoniae, 85 strains of Haemophilus influenzae. 71 strains of Pseudomonas aeruginosa (non-mucoid strains), 27 strains of Pseudomonas aeruginosa (mucoid strains), 33 strains of Moraxella subgenus Branhamella catarrhalis, 17 strains of Klebsiella pneumoniae etc., and the susceptibilities of these strains were assessed except for those strains that died during transportation. S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus: MRSA) accounted for 55.0%. The frequency of the drug resistant bacteria decreased comparing to the previous year's 67.3%. Arbekacin (ABK) and vancomycin (VCM) showed the most potent activities against MRSA. Imipenem (IPM) and panipenem (PAPM) of carbapenems showed the most potent activities with MIC80S of 0.063 microgram/ml against S. pneumoniae. The frequency of penicillin (PC)-intermediate S. pneumoniae (PISP)+PC-resistant S. pneumoniae (PRSP) had decreased gradually, that is, in 1995 the frequency of it was 40.3%, but that was 30.9% in 1997. Against H. influenzae and M.(B.) catarrhalis, all the drugs showed good activities. But the sensitive strains of them against ceftazidime (CAZ) had decreased in 1997, compared those in 1995 and 1996. Meropenem (MEPM), IPM and tobramycin (TOB) showed the most potent activity against P. aeruginosa (mucoid strains). And TOB and ciprofloxacin (CPFX) showed the most potent activities against P. aeruginosa (non-mucoid strains). All drugs except ampicillin (ABPC) were more active against K. pneumoniae in 1997 than that in 1996. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. The examination of age distribution indicated that the proportion of patients with ages over 70 years was 45.5% of all the patients showing a slight increase year by year. About the proportion of diagnosed diseases, not so particular changes were recognized as follows: Bacterial pneumonia and chronic bronchitis were the most frequent with 33.6% and 29.1%, respectively. Number of strains isolated from patients before administration of antibiotics were more than those after administration of them in chronic bronchitis, but these had reversed in bacterial pneumonia. The tendency in bacterial pneumonia had been acknowledged since 1995. The increase of S. aureus and P. aeruginosa (both mucoid and non-mucoid strains) isolated after administration of antibiotics, has suggested the decrease of the susceptibility of these strains against antibiotics. Administration of antibiotics has changed the results of the frequency of isolation of bacterial species. Bacterial isolations before administration of antibiotics were as follows: S. pneumoniae 24.5%, H. influenzae 21.4%, S. aureus 18.4% and P. aeruginosa 12.2%. The frequencies of S. aureus decreased after antibiotics administration over 15 days, but the frequencies of P. aeruginosa was not affected. The frequencies of P. aeruginosa was 47.8% after administration over 15 days. From patients administered antibiotics of penicillins and cephems. S. aureus was mainly detected with 31.7-58.3%, and from patients administere

Adult↗
PubMed1999

[Exogenous lipoid pneumonia induced by inhalation of insecticide].

We report a case of exogenous lipoid pneumonia induced by insecticide. A 67-year-old man was admitted to our hospital with complaints of dyspnea cough, hemoptysis, and shivering 6 hours after inhaling an insecticide. A chest radiograph on admission disclosed consolidation in the right upper lobe. Chest computed tomography showed nodular infiltrates associated with ground-glass opacities. Bronchoalveolar lavage fluid was hemorrhagic and showed neutrophilia. Pathological examination of transbronchial lung biopsy specimens showed numerous vacuolated macrophages in alveolar spaces. Electron microscopy demonstrated lipid droplets in the cytoplasm of these macrophages. These findings together yielded a diagnosis of exogenous lipoid pneumonia induced by insecticide. In addition, we experimentally induced a similar form of lipoid pneumonia in rats by intratracheal instillation of the same insecticide.

Aged↗
PubMed1999

[An autopsy case of MPO-ANCA-positive microscopic polyangiitis with manifestations of pulmonary hemorrhage and diffuse alveolar damage].

A 68-year-old woman was admitted to our hospital because of fever of unknown origin and pain in the lower extremities. Six weeks after onset, diffuse infiltrative shadows were observed on chest X-ray films, and marked hypoxemia and progressive renal dysfunction suddenly developed. Corticosteroid therapy (2 courses of pulse therapy, each consisting of methylprednisolone at 500 mg/day for 3 days) was not effective, and the patient died 9 weeks after onset because of respiratory failure. Serologic tests were positive for MPO-ANCA. Histopathologic findings at autopsy disclosed arteriolar fibrinoid necrosis in tissues of the liver, spleen, lungs, and kidneys, thus yielding a diagnosis of microscopic polyangiitis. Lung specimens also demonstrated massive alveolar hemorrhaging in the mid-lung fields and diffuse alveolar damage (DAD) in all lobes. Pulmonary hemorrhage coexistent with DAD worsens the prognosis for microscopic polyangiitis in patients positive for MPO-ANCA.

Aged↗
PubMed1998

Stable transfection of retinoblastoma gene promotes contact inhibition of cell growth and hepatocyte nuclear factor-1-mediated transcription in human hepatoma cells.

The retinoblastoma (Rb) gene is a key factor involved in cell cycle regulation. In the present study, alterations in cell growth and expression of the alpha-fetoprotein and albumin genes by the stable transfection of the Rb gene were analyzed in HuH-7 human hepatoma cells. Cell growth was almost similar in the Rb gene-transfected and nontransfected cells at the sparse cell density. However, under a confluent condition, contact inhibition of cell growth was stimulated by the Rb gene transfection. By Northern blotting, the levels of the alpha-fetoprotein and albumin mRNA as well as the transcript of hepatocyte nuclear factor-1 (HNF-1), a liver-specific transcriptional factor regulating both genes, were apparently elevated in the Rb gene-transfected cells, compared with the nontransfected cells. These results suggest that the Rb gene transduction promotes contact growth inhibition in conjunction with the enhanced HNF-1-mediated liver-specific gene transcription in human hepatoma cells.

Carcinoma, Hepatocellular↗
PubMed1998

Type I interferon induces inhibitory 16-kD CCAAT/ enhancer binding protein (C/EBP)beta, repressing the HIV-1 long terminal repeat in macrophages: pulmonary tuberculosis alters C/EBP expression, enhancing HIV-1 replication.

We have previously observed that HIV-1 replication is suppressed in uninflamed lung and increased during tuberculosis. In vitro THP-1 cell-derived macrophages inhibited HIV-1 replication after infection with Mycobacterium tuberculosis. Suppression of HIV-1 replication was associated with inhibition of the HIV-1 long terminal repeat (LTR) and induction of ISGF-3, a type I interferon (IFN)-specific transcription factor. Repression of the HIV-1 LTR required intact CCAAT/enhancer binding protein (C/EBP) sites. THP-1 cell-derived macrophages infected with M. tuberculosis, lipopolysaccharide, or IFN-beta induced the 16-kD inhibitory C/EBPbeta isoform and coincidentally repressed HIV-1 LTR transcription. C/EBPbeta was the predominant C/EBP family member produced in THP-1 macrophages during HIV-1 LTR repression. In vivo, alveolar macrophages from uninflamed lung strongly expressed inhibitory 16-kD C/EBPbeta, but pulmonary tuberculosis abolished inhibitory C/EBPbeta expression and induced a novel C/EBP DNA binding protein. Therefore, in vitro, proinflammatory stimulation produces an IFN response inhibiting viral replication by induction of a C/EBPbeta transcriptional repressor. THP-1 cell-derived macrophages stimulated with type I IFN are similar to alveolar macrophages in the uninflamed lung in vivo. In contrast, the cellular immune response in active pulmonary tuberculosis disrupts this innate immunity, switching C/EBP expression and allowing high level viral replication.

Base Sequence↗
PubMed1998

Splicing patterns of type XI collagen transcripts act as molecular markers for osteochondrogenic tumors.

Primary transcripts for three distinct alpha chains of the type XI collagen molecule (alpha1(XI), alpha2(XI) and alpha3[XI]) undergo tissue-specific alternative splicing during the process of osteochondrogenesis. In the present study, we analyzed the splicing patterns of type XI collagen genes in osteochondrogenic tumors as well as in various normal tissues using the reverse transcription-polymerase chain reaction method. Analysis of normal subjects revealed the coordinated expression of short alpha1(XI), alpha2(XI) and alpha3(XI) transcripts in the normal differentiated cartilage. Osteochondroma followed this pattern, reflecting the highly chondrogenic phenotype of this benign tumor. Another benign tumor, chondroblastoma, exclusively expressed the long alpha1(XI) transcript, probably reflecting the lack of a chondrogenic nature. Among malignant chondrogenic tumors, the splicing patterns of type XI collagen transcripts were more complex, showing dissociated expression of long alpha1(XI) and short alpha2(XI) mRNAs. This expression pattern may reflect heterogeneous cell populations and may also reflect various levels of cell differentiation in malignant tumors. In addition, short alpha3(XI) expression switched to the long transcript as chondrosarcomas became more aggressive. Thus, the alternative splicing of type XI collagen genes seems to be oncodevelopmentally regulated and splicing analysis may therefore be a useful marker for chondrogenic tumors.

Alternative Splicing↗
PubMed1998

Dihydroheptaprenyl and dihydrodecaprenyl monophosphates induce apoptosis mediated by activation of caspase-3-like protease.

Dolichyl phosphate, an essential carrier lipid in the biosynthesis of N-linked glycoprotein, has been found to induce apoptosis in rat glioma C6 cells and human monoblastic leukemia U937 cells. In the present study, dolichyl phosphate and structurally related compounds were examined regarding their apoptosis-inducing activities in U937 cells. Dihydroheptaprenyl and dihydrodecaprenyl phosphates, of which isoprene units are shorter than that of dolichyl phosphate, induced apoptosis in U937 cells. This phenomenon occurred in a dose- and time-dependent manner, as seen with dolichyl phosphate-induced apoptosis. Derivatives of the same isoprene units of dolichyl phosphate, such as dolichol, dolichal or dolichoic acid, did not induce DNA fragmentation. Farnesyl phosphate and geranylgeranyl phosphate also failed to induce apoptosis. During apoptosis, the caspase family of cysteine proteases play important roles. We observed that apoptosis induced by dihydroprenyl phosphate was mediated by caspase-3-like (CPP32-like) activation but not by caspase-1-like (ICE-like) activation. This caspase-3-like activation was inhibited by a specific inhibitor of caspase-3, DEVD-CHO, but not by an caspase-1 inhibitor YVAD-CHO. We interpret these results to mean that dihydroprenyl phosphates with more than seven isoprene units have apoptosis-inducing activity and that their signal is mediated by caspase-3-like activation.

Apoptosis↗
PubMed1998

Effect of pentylenetetrazol treatment on cholecystokinin mRNA and peptide levels in rat hippocampus and cortex.

After treatment with pentylenetetrazol (PTZ), cholecystokinin (CCK) mRNA and CCK-like immunoreactivity (CCK-LI) levels were determined in rat hippocampus and cortex at different time points. In the temporal cortex treatment with 60 mg/kg PTZ, i.p., induced increases of CCK mRNA and CCK-LI levels at 2 days after the injection. In the hippocampus, a similar increase of CCK mRNA level was observed on the second day. By contrast, in the frontal cortex, CCK-LI level was increased at 10 days after the treatment with PTZ. These data show that PTZ increases both CCK mRNA and CCK-LI levels in these rat brain regions at different time.

Animals↗