Search PubMed⌕ Search

Biomedical subjects

K Oishi

Publications and source records attributed to K Oishi.

At least 73 records · Page 4Linked to original sources
PubMed2000

Oxidative cell damage in Kat-sod assay of oxyhalides as inorganic disinfection by-products and their occurrence by ozonation.

Nine oxyhalides as possible inorganic disinfection by-products were tested for oxidative cell damage by Kat-sod assay with E. coli mutant strains deficient in the active oxygen-scavenging enzymes. Chlorine dioxide, chlorite, and iodate were highly cytotoxic, whereas in the presence of cysteine, bromate (BrO3-) and metaperiodate (IO4-) showed more growth inhibition toward the superoxide dismutase-deficient strains than the wild strain. BrO3- also showed oxidative mutagenicity with cysteine or glutathione ethyl ester in S. typhimurium TA 100. To identify oxyhalides formed by ozonation of raw water containing sea water, the occurrence of ozonation by-products of bromide and iodide was investigated. The results indicate that BrO3- is toxicologically one of the most remarkable oxyhalides detectable in drinking water because IO4- was not detected in the ozonated solution of iodide, and the ozonation condition to lower BrO3- is to keep it neutral in the presence of ammonium ion.

Bromates↗
PubMed2000

Pulmonary infection caused by Rhodococcus equi in HIV-infected patients: report of four patients from northern Thailand.

We report four human immunodeficiency virus (HIV)-infected patients (3 men and one woman, average age, 34.3 years) with pulmonary infection (two with pneumonia and two with lung abscess) caused by Rhodococcus equi. These patients, who presented with fever and productive cough, were admitted to Nakornping Hospital in northern Thailand. Chest roentgenograms showed pulmonary infiltration and/or cavitary lesions. Their conditions were poor because of severe anemia, and transfusion was necessary in three of the four patients. Before culture results were available, the etiologic microorganisms identified in sputum smears were gram-positive and acid-fast coccobacilli. One of the four patients had a mixed infection with R. equi and Salmonella enteritidis. The mean CD4 lymphocyte count in the three tested patients was 10/mm3 (CD4/CD8 ratio = 0.057). Four isolates of R. equi were sensitive to imipenem, minocycline, erythromycin, vancomycin, and ciprofloxacin (minimum inhibitory concentrations; MICs, 100 microg/ml) to rifampicin. Two patients were treated with erythromycin plus rifampicin, while the other two were treated with anti-tuberculous drugs. However, treatment was ineffective; three patients subsequently died because of respiratory failure, and one patient did not improve and was transferred to another hospital in her hometown.

AIDS-Related Opportunistic Infections↗
PubMed2000

Vitellogenin of the cicada Graptopsaltria nigrofuscata (Homoptera): analysis of its primary structure.

We cloned and sequenced the cDNA of vitellogenin (Vg) from the cicada Graptopsaltria nigrofuscata (Homoptera). The deduced amino acid sequence of 1987 residues (including 16 residues for a putative signal peptide) was obtained. The pro-Vg was cleaved into two subunits between residues 379 and 380 following a consensus RXXR cleavage site sequence, secreted as S-Vg (apparent molecular weight 43 kDa) and L-Vg (200 kDa), sequestered, and stored in the egg as two vitellins (Vns), S-Vn and L-Vn, with similar respective molecular weights. There was a single long serine-rich stretch closely following the cleavage site. The entire amino acid sequences of the Vgs from the eight insects so far reported could be aligned confidently. The presence of subdomains I-V (areas of relatively high amino acid conservation) and of 10 cysteines at conserved locations at the C-terminus, noted previously among insect Vgs, were confirmed. Antisera raised against G. nigrofuscata S- and L-Vn cross-reacted with the S- and L-Vg/Vn, respectively, of all three other cicada species examined. Another major egg protein (170 kDa) unrelated to Vg/Vn, was also detected in all species examined.

Amino Acid Sequence↗
PubMed2000

A simple and rapid method for cloning insect vitellogenin cDNAs.

We describe a simple and rapid method for cloning insect vitellogenin (Vg) cDNAs. The method relies on the facts that insect Vg amino acid sequences can be aligned confidently along their entire lengths and that a short, highly conserved GL/ICG motif and up to nine cysteine residues that follow at conserved locations are present near the C-termini. An adaptor-ligated double-strand cDNA library is constructed from poly(A)+ RNA prepared from vitellogenic female fat body tissues using a commercial kit, and subjected to PCR with each of the degenerate nucleotide sequences for the GL/ICG motif and the adaptor sequence as primers. The PCR products (0.7-0.9 kb, representing the 3' portion) are cloned, the nucleotide sequences are determined, and the deduced amino acid sequences are aligned with the known insect Vg sequences starting from the GL/ICG motif. Gene-specific primers corresponding to the sequences near the 5'-termini of the initial clones and the adaptor sequence are employed to obtain the remaining 5' portion of the Vg cDNAs. The method was successfully applied to the bean bug Plautia stali (Heteroptera), revealing three Vg genes.

Amino Acid Sequence↗
PubMed2000

Production and structural analysis of PP-V, a homologue of monascorubramine, produced by a new isolate of Penicillium sp.

A fungal strain newly isolated from soil has been found to produce a violet water-soluble pigment (PP-V) in high quantity when cultured in a medium consisting of soluble starch and citrate buffer. Glucose repressed the production of this pigment. PP-V has the molecular formula C23H25NO6 revealed by HR-FAB mass spectroscopy and has been shown to be composed of an isoquinoline skeleton, a n-octanoyl group, and a 2-propenoic acid group by NMR. In conclusion, PP-V is a novel compound, 3-(9a-methyl-3-octanoyl-2,9-dioxo-2,7,9,9a-tetrahydro-furo[3,2-g]isoquinolin-6-yl)acrylic acid; a homologue of monascorubramine in which the 1-propenyl group is converted to a 2-propenoic acid group.

Journal Article↗
PubMed2000

A comparative clinical study of pneumonia by penicillin-resistant and -sensitive Streptococcus pneumoniae in a community hospital.

OBJECTIVE: This study aimed to determine the clinical difference of pneumonia between penicillin-resistant and penicillin-sensitive Streptococcus pneumoniae. METHODOLOGY: Forty-nine cases in 46 patients of pneumococcal pneumonia were studied from December 1992 to May 1997. There were 24 cases (in 22 patients) of penicillin-resistant pneumococci (PRSP) pneumonia which were compared with 25 cases (in 24 patients) with penicillin-sensitive pneumococci (PSSP). RESULTS: Both the mean age and the underlying disease states did not differ between the two groups. However, hospital-acquired pneumonia and previous use of antibiotics were observed in eight (33.3%) and 12 (50.0%) patients in PRSP compared with three (12.0%) and two (8.0%) in PSSP, respectively. The clinical efficacy rate and bacteriological eradication rates were 87.5 and 87.5% in PRSP compared with 87.5 and 87.0% in PSSP, respectively. Minimum inhibitory concentration (MIC) of antibiotics against 30 pneumococcal isolates was examined, and 10 strains ranged from 0.10-0.78 microg/mL and five strains were more than 1.56 microg/mL against penicillin G, while the MIC showed higher resistance to other antibiotics except for the carbapenems. Serotyping of the isolates by antiserum revealed differences in the predominant types PRSP (19F) and PSSP (6A,9V) [corrected]. CONCLUSIONS: We must care for not only community-acquired infection but also nosocomial transmission of PRSP pneumonia. Most patients with infections due to PRSP tended to have a milder illness with a good outcome (no patient died). As such it appears that empiric therapy for pneumococcal pneumonia does not require modification from what is recommended at present. However, in patients with infection due to highly resistant strains, and who are not responding to conventional therapy should have their treatment modified according to subsequent susceptibility testing.

Anti-Bacterial Agents↗
PubMed2000

Expression of chemokine receptors on CD4+ T cells in peripheral blood from HIV-infected individuals in Uganda.

CXCR4, a coreceptor for T cell (T)-tropic HIV-1, is preferentially expressed on naive T cells, whereas CCR5, a coreceptor for macrophage (M)-tropic HIV-1, is preferentially expressed on previously activated memory T cells and the Th1 subset of CD4+ T cells. CCR4 is preferentially expressed on the Th2 subset of CD4+ T cells. A cross-sectional flow cytometry study was conducted to evaluate the expression of CXCR4, CCR5, and CCR4 on the peripheral blood CD4+ T cells from African HIV-1-infected and uninfected Ugandan adults. The plasma viral load in HIV-1-infected individuals was also examined. Upregulation of CCR4 and CCR5 expression but no decrease in CXCR4 expression on CD4+ T cells were obtained in peripheral blood from African adults with progression of the disease. Plasma HIV-1 viremia significantly and inversely correlated with the peripheral CD4+ T cell count but did not correlate with the degree of CCR4 and CCR5 expression on the peripheral CD4+ T cells in HIV-1-infected individuals. Our present data suggest an increase in percentage of activated memory CD4+ T cells in the advanced stage of HIV-1 infection among African adults. There was no evidence of a Th1 to Th2 shift in terms of chemokine receptor expression profile with advancing disease in the peripheral blood of these subjects.

Adult↗
PubMed2000

The significance of serum homocysteine levels in diabetic patients on haemodialysis.

BACKGROUND: Atherosclerotic diseases are the major cause of mortality and morbidity in patients on haemodialysis (HD). Furthermore, the prognosis of diabetic patients on HD is especially poor due to atherosclerotic complications. Because homocysteine (Hcy), a sulfur-containing amino acid, is emerging as an important risk factor for atherosclerosis in patients with end-stage renal disease, we examined the significance of serum Hcy levels in diabetic patients on HD. METHODS: We measured total serum Hcy levels (tHcy) in 31 patients with diabetes mellitus on HD (DM group) and 37 non-diabetic patients on HD (N group), adjusting for age and HD duration. Linear regression analysis was used to assess the correlation of multiple variables to tHcy. RESULTS: The proportion of atherosclerotic disease in the DM group was significantly higher than in the N group. However, serum tHcy, serum creatinine and per cent creatinine generation rate in the DM group were significantly lower than in the N group. In the DM group, serum tHcy was positively correlated with creatinine, albumin and per cent creatinine generation rate, respectively. This was not the case in the N group. CONCLUSIONS: The demethylation pathway in methionine metabolism in the liver, which is linked directly to the creatinine generation system, may be disturbed in diabetic patients on HD. This may be the reason why serum tHcy and creatinine in diabetic patients on HD are lower than in non-diabetic patients on HD. Therefore, it is necessary to consider the possibility of an altered relation between serum tHcy and vessel disease when evaluating the atherogenic risk in diabetic patients on HD.

Aged↗
PubMed2000

Antibacterial properties of Pseudomonas aeruginosa immunotype 1 lipopolysaccharide-specific monoclonal antibody (MAb) in a murine thigh infection model: combined effects of MAb and ceftazidime.

A murine monoclonal antibody (MAb) specific for the Pseudomonas aeruginosa immunotype 1 (It-1) lipopolysaccharide (LPS) O-side chain was evaluated in terms of its in vitro bactericidal opsonophagocytic activity and in vivo bacterial killing in a mouse thigh infection model. An immunoglobulin (Ig) G2a MAb Ld3-2F2, specific for It-1 LPS, mediated in vitro complement-dependent opsonophagocytic killing at a concentration of 10 microg/ml. MAb-mediated, complement-dependent killing also occurred in the absence of neutrophils at serum concentrations in excess of 20%. A remarkable synergy was observed in opsonophagocytic assays between MAb Ld3-2F2 (0.5 microg/ml) and ceftazidime (1/4 MIC). The administration of MAb Ld3-2F2 at a level of 1 microg resulted in a significant decrease in the number of bacteria in the thigh muscles of normal mice, while 100 microg of the same MAb was required for one log of reduction in the number of bacteria at the same site in neutropenic mice. The combined therapy with MAb Ld3-2F2 and ceftazidime provided a significant reduction in the density of bacteria in the thigh muscle at 9 hr post-infection in normal and neutropenic mice as compared with those after treatment alone or with no treatment (P< 0.01). These favorable in vitro and in vivo interactions of an LPS-specific IgG MAb and ceftazidime strongly support their potential for use in therapy, combined with an LPS-reactive MAb and parenteral antipseudomonas beta-lactam antibiotics in the therapy of systemic Pseudomonas infections in normal and neutropenic hosts.

Animals↗
PubMed2000

Impairment of endotoxin-induced macrophage inflammatory protein 2 gene expression in alveolar macrophages in streptozotocin-induced diabetes in mice.

To elucidate the mechanism of the high incidence of lower respiratory tract infections in patients with diabetes mellitus, we investigated the kinetics of production of macrophage inflammatory protein 2 (MIP-2), an important mediator of lung neutrophil recruitment, using mice with streptozotocin-induced diabetes. Intratracheal challenge with 1 mg of lipopolysaccharide (LPS), an endotoxin, per kg of body weight resulted in a time-dependent increase in the levels of MIP-2 protein in bronchoalveolar lavage (BAL) fluid, with the peak concentration (49.4 +/- 13 ng/ml) occurring at 3 h and significant neutrophil accumulation becoming apparent by 3 h in normal mice. In diabetic mice, the peak level of MIP-2 protein in BAL fluid did not occur until 6 h and was reduced to 21.9 +/- 10 ng/ml. Immunohistochemical studies using anti-MIP-2 antibody confirmed that the main cellular source of MIP-2 in the lung after LPS challenge was alveolar macrophages (AMs) in normal mice. The lungs in diabetic mice, however, showed no AMs staining for MIP-2 within 3 h after LPS challenge. PCR analysis using whole-lung RNA showed a time-dependent increase in MIP-2 mRNA levels after LPS instillation. The level of MIP-2 mRNA in diabetic mice was markedly decreased compared to that in normal mice. Our results indicate that impairment of MIP-2 mRNA expression in the AMs in diabetic mice resulted in delayed neutrophil recruitment in the lungs, and this may explain the development and progression of pulmonary infection in diabetes mellitus.

Animals↗
PubMed2000

Molecular analysis of methicillin-resistant Staphylococcus aureus as a causative agent of bronchopulmonary infection: relation to colonization in the upper respiratory tract.

Using five diagnostic markers, we compared the types of 72 strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated simultaneously from the nasal cavity, pharynx, and sputum from 24 patients. Almost identical MRSA types had colonized the nasal cavity and sputum from the same patient for 21 (88%) of the patients. We speculate that most MRSA organisms isolated in sputum are derived from the nasal cavity, while a few are derived from the pharynx.

Electrophoresis, Gel, Pulsed-Field↗
PubMed2000

Agonist-induced isometric contraction of smooth muscle cell-populated collagen gel fiber.

String-shaped reconstituted smooth muscle (SM) fibers were prepared in rectangular wells by thermal gelation of a mixed solution of collagen and cultured SM cells derived from guinea pig stomach. The cells in the fiber exhibited an elongated spindle shape and were aligned along the long axis. The fiber contracted in response to KCl (140 mM), norepinephrine (NE; 10(-7) M), epinephrine (10(-7) M), phenylephrine (10(-6) M), serotonin (10(-6) M), and histamine (10(-5) M), but not acetylcholine (10(-5) M). Phentolamine (10(-7) M) produced a parallel rightward shift of the NE dose-response curve. Moreover, NE-induced contraction was partially inhibited by nifedipine and completely abolished by the intracellular Ca(2+) chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester, the myosin light chain kinase inhibitor ML-9, the Rho kinase inhibitor Y-27632, and papaverine. A [(3)H]quinuclidinyl benzilate binding study revealed that the loss of response to acetylcholine was due to the loss of muscarinic receptor expression during culture. The expression of contractile proteins in the fibers was similar to that in cultured SM cells. These results suggest that, although the fiber is not a model for fully differentiated SM, contractile mechanisms are maintained.

Acetylcholine↗
PubMed2000

Biosynthesis of PP-V, a monascorubramine homologue, by Penicillium sp. AZ.

The biosynthetic pathway of PP-V, a new monascorubramine homologue, was elucidated by 13C-labeling studies. The [1-13C] of acetate was incorporated into 2-, 3a-, 4a-, 6-, 8-, 9-, 11-, 13-, 15-, 17-, and 19-Cs of PP-V, and the [2-13C], into 3-, 4-, 5-, 8a-, 9a-, 10-, 12-, 14-, 16-, 18-, and 20-Cs. These incorporation patterns coincide with those reported in the biosynthesis of a Monascus azaphilone pigment, monascorubrin.

Journal Article↗
PubMed2000

A linkage map of the turnip sawfly Athalia rosae (Hymenoptera: Symphyta) based on random amplified polymorphic DNAs.

A linkage map was constructed for the sawfly, Athalia rosae (Hymenoptera), based on the segregation of random amplified polymorphic DNA (RAPD) markers and a visible mutation, yellow fat body (yfb). Forty haploid male progeny (20 yfb and 20+) from a single diploid female parent (yfb/+) were examined. Sixty-one of the 180 arbitrary primers tested by polymerase chain reaction (PCR) produced one or more RAPD bands. A total of 79 RAPD markers were detected. Of these, seven showed significant deviation from the expected 1:1 ratio, and were therefore excluded from further analysis. The remaining 72 RAPD markers and the marker mutation, yfb, were subjected to linkage analysis. Sixty RAPD markers and the yfb marker were organized into 16 linkage groups, spanning a distance of 517.2 cM. Twelve RAPD markers showed no linkage relationship to any group. Thirteen gel-purified RAPD bands were cloned and sequenced to generate the sequence-tagged sites (STSs). A single locus was represented by two markers, with one of them having a short internal deletion.

Animals↗
PubMed2000

Biphasic regulation of Fc-receptor mediated phagocytosis of rabbit alveolar macrophages by surfactant phospholipids.

Dipalmitoyl phosphatidylcholine (DPPC) is a major phospholipid constituent in the pulmonary surfactant, whereas lysophosphatidylcholine (Lyso-PC) is a minor constituent, this membrane phospholipid being produced at inflammatory sites in association with activation of phospholipase A2. To determine the role of these two different forms of phospholipids in the phagocytic function of alveolar macrophages (AM), we examined the effects of DPPC or Lyso-PC on Fc-mediated phagocytosis. We demonstrated a significant decrease of the ingestion activity of AM for anti-sheep erythrocyte immunoglobulin G-coated sheep erythrocytes (EA: IgG) by DPPC. On the other hand, Lyso-PC caused significantly increased ingestion of EA: IgG by AM. These data indicate that increase of Lyso-PC due to the hydrolysis of DPPC through activation of phospholipase A, may up-regulate AM-mediated phagocytic functions in the alveolar milieu associated with infections and inflammation. DPPC may suppress and stabilize the AM-mediated phagocytosis in the normal alveolar environment.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2000

Autonomic response specificity during motor imagery.

It has been reported that activation of autonomic effectors during mental simulation of voluntary motor actions (motor imagery: MI) may be explained by two different factors, i.e., functions of preparation or anticipation of actual exercise (motor anticipation) and the central motor programming/planning which acts during actual motor action (motor programming). This study was designed to clarify how these factors participate during MI, utilizing two mental tasks with high mental stress, i.e., MI and mental arithmetic (MA). Several autonomic effectors' responses were compared between MI of a 500 m speed skating sprint and MA. Subjects were eight 18 to 25 year old young male speed skate athletes, all of them could easily and vividly imagine a 500 m speed skating sprint. Duration of the MI ranged from 35 to 38 sec and these were very close to each subject's actual best record (means of absolute differences were less than 0.6 sec, i.e., less than 1.7% relatively). A significant decrease of skin resistance (SR), increases of heart rate (HR) and respiration rate were observed in both MI and MA when compared to each control resting level (excluding one subject for respiration rate during MI). SR decreased during MI (mean and SD of 8 subjects: 45.9 +/- 17.7%) and MA (39.7 +/- 16.8%), with no significant differences between MI and MA (t = 1.29, by paired t-test). HR increased significantly above control values in MA (10.3 +/- 4.3%) and MI (44.3 +/- 18.8%). However, the increase during MA was significantly smaller (t = 4.99, p < 0.001) than in MI. Respiratory rate increased significantly in both MI (46.5 +/- 30.9%) and MA (27.7 +/- 14.6%), with no significant difference between MI and MA (t = 1.82) due to the large individual variation in MI. The frequency of respiration was fairly regular during MA, but quite irregular during MI (similar to those during actual motor actions). The central nervous system which acts in MI may possess the function of activation of target effectors which play an important role in actual exercise, on the basis of incremental vigilance level induced by the function of motor anticipation.

Adolescent↗