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Yasuyuki Yoshizawa

Publications and source records attributed to Yasuyuki Yoshizawa.

At least 19 recordsLinked to original sources
PubMed2006

Study of nasopharyngeal bacterial flora. Second report. Variations in nasopharyngeal bacterial flora in children aged 6 years or younger when administered antimicrobial agents. Part 1.

In our first report, we investigated nasopharyngeal bacterial flora related to penicillin-resistant Streptococcus pneumoniae (PRSP) and beta-lactamase-negative ampicillin-resistant Haemophilus influenzae (BLNAR) and their relation to acute upper respiratory tract infection (AURTI). This report analyzes the results of a study of nasopharyngeal bacterial flora before the administration of antimicrobial agents in 172 AURTI patients aged 6 years or younger. In addition to Gram staining, microscopic observation, and culturing, a polymerase chain reaction (PCR) method was used to identify PRSP (gPRSP) and BLNAR (gBLNAR) drug-resistant genes. Of the patients analyzed, 90% had acute otitis media (AOM) and were aged 2 years or younger. The antimicrobial agents administered were amoxicillin (34%), clavulanic acid/amoxicillin (11%), cefditren pivoxil (CDTR-PI) (43%), and others (12%). This was particularly true for patients administered CDTR-PI, among whom there were many who had already suffered one or more episodes of AOM by the age of 1 year or younger, and many in which gPRSP were detected (P < 0.01). There was a significant relation between the degree of nasopharyngeal inflammation indicated by leukocyte infiltration images and the amount of S. pneumoniae and H. influenzae detected, which are the main pathogenic bacteria causing AOM (P < 0.01). In addition to leukocyte infiltration images, there were cases in which shedding of ciliated cells was observed and/or giant monocytic cells. Both nasopharyngeal leukocyte infiltration images and/or shed cell findings observed in infant AURTI cases are important indices for the prompt detection of gPRSP and/or gBLNAR and appropriate doses of antimicrobial agents.

Age Factors↗
PubMed2006

Study of nasopharyngeal bacterial flora. Second report. Variations in nasopharyngeal bacterial flora in children aged 6 years or younger when administered antimicrobial agents. Part 2.

This report focuses on changes in the nasopharyngeal bacterial flora before and after administration of antimicrobial agents in 172 cases of acute upper respiratory infection in patients aged 6 years or younger. The antimicrobial agents administered were amoxicillin (AMPC) (34%), clavulanic acid/amoxicillin compound (11%), cefditren pivoxil (CDTR-PI) (43%), and others (12%). Changes in nasopharyngeal bacterial flora were investigated with reexaminations conducted after 2-5 days (day 2-5 subgroup), 6-10 days (day 6-10 subgroup), and 11 days and thereafter. There was a significant reduction in the Streptococcus pneumoniae detected in the group administered AMPC (AMPC group) in the day 2-5 subgroup and the day 6-10 subgroup. There was also a significant decrease in H. influenzae in the group administered CDTR-PI (CDTR-PI group) in the day 2-5 subgroup. From this it was inferred that for the most part significant changes in infectious nasopharyngeal bacteria occurred in the day 2-5 subgroups. However, a significant improvement in the degree of inflammation, as indicated by leukocyte infiltration images for the AMPC group, was observed in the day 2-5 subgroup, and for the CDTR-PI group in the day 6-10 subgroup. On the other hand, in both the antimicrobial agent groups, S. pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis were newly detected at reexamination. Furthermore, a difference in the incidence of these bacteria was observed between the 2 antimicrobial agent groups. It was suggested that such phenomena related to the survival of resistant strains or a recurrence otitis media.

Anti-Infective Agents↗
PubMed2006

Study of upper respiratory tract bacterial flora: first report. Variations in upper respiratory tract bacterial flora in patients with acute upper respiratory tract infection and healthy subjects and variations by subject age.

With the appearance of penicillin-resistant Streptococcus pneumoniae, there has been increasing debate concerning antimicrobial treatments for acute upper respiratory tract infection (AURTI) and acute otitis media in children. This study compares the nasopharyngeal bacterial flora in patients with AURTI (AURTI group; 710 subjects) and healthy subjects (HS group; 380 subjects). The comparisons were made between subjects aged 6 years or younger (0-6 subgroup: 330 subjects), between 7 and 74 years (7-74 subgroup: 668 subjects), and 75 years and older (92 subjects), because the subjects were subgrouped as described above dependent on the maturity of the protective immunity. In the HS group 7-74 subgroup, viridans group streptococci, Staphylococcus aureus, coagulase-negative staphylococci, and Corynebacterium sp. with a detection rate of 10% or more were classified as normal nasal flora (NNF), and Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis were classified as drum cavity pathogens (DCP). In the 0-6 subgroup, although the detection rate for DCP bacteria in the AURTI group tended to be high, it did not reach a significant difference, whereas the detection rate for NNF bacteria was significantly lower. This trend was also observed to some degree in the other age subgroup. In the 0-6 subgroup, leukocyte infiltration observed with a microscope indicated the closest relationship between S. pneumoniae detection rate and detection quantity. These results suggest that in the 0-6 subgroup the tendency for patients with AURTI to have NNF bacteria as well as DCP bacteria should be taken into consideration.

Acute Disease↗
PubMed2006

A clinical study of hypersensitivity pneumonitis presumably caused by feather duvets.

BACKGROUND: Bird fancier's lung (BFL) is a type of hypersensitivity pneumonitis induced by the inhalation of bird-related antigens. The BFL induced by feathers is difficult to diagnose because feathers are generally unrecognized as a causative antigen. OBJECTIVE: To determine the clinical features of BFL presumably induced by feather duvets (feather duvet lung) to provide clues for diagnosis. METHODS: We performed a retrospective review of the medical records of patients with feather duvet lung evaluated between April 1, 2000, and June 30, 2003, at the Tokyo Medical and Dental University Hospital in Japan. RESULTS: Seven patients with feather duvet lung were included in this study; 4 patients had acute disease and 3 had chronic BFL. Duration of contact with feather duvets was 1 month to 10 years. Serum KL-6 and surfactant protein D levels were elevated in all the patients. Specific antibodies against avian antigens were positive in acute BFL but negative in chronic BFL. Antigen-induced lymphocyte proliferation in peripheral blood or bronchoalveolar lavage cells was positive in all the patients. The diagnosis was confirmed by an environmental or inhalation provocation test. CONCLUSIONS: Feather duvets can induce acute and chronic BFL. Physicians should be aware of feather duvets as a cause of BFL because feather duvets are becoming more prevalent.

Adult↗
PubMed2006

Proinflammatory and anti-inflammatory cytokine gene polymorphisms in hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HP) is an immunologically-mediated lung disease caused by repeated inhalation of dispersed antigen. Various cytokines have been reported to be involved in the immunopathogenesis of HP Recently, some reports suggested an association between the genetic control of cytokine production and disease susceptibility. To evaluate whether cytokine gene polymorphisms are associated with HP, we performed a case-control association study involving 61 patients with HP, consisting of summer-type HP (SHP) and bird fancier's lung (BFL, also named bird fancier's disease), as well as 101 healthy controls. Polymorphisms of the genes for tumor necrosis factor (TNF)-alpha (-308G/A, -857C/T, -863C/A, -1031T/C), interleukin (IL)-10 (-592C/A, -819C/T, -1082G/A), transforming growth factor (TGF)-beta1 (-509C/T, +869T/C), and IL-6 (-634C/G) were examined by restriction fragment length polymorphism analysis. There were no significant differences in allele frequency and genotype distribution among control, SHP, and BFL group. When HP group was divided into acute or chronic, no significant differences were detected between any groups. LPS-stimulated IL-6 secretion by whole blood cells was similar between subjects with GG genotype and non-GG genotype in IL-6 -634C/G polymorphism. In conclusion, the association between HP susceptibility and cytokine polymorphisms studied was not demonstrated.

Alveolitis, Extrinsic Allergic↗
PubMed2006

[Clinical evaluation of bird related hypersensitivity pneumonitis].

We retrospectively evaluated 8 cases of bird related hypersensitivity pneumonitis in Tenri hospital, all of whom underwent surgical lung biopsy. They had a history of contacting with birds and had serological studies using lymphocyte stimulation test to pigeon serum or antibody in serum and bronchoalveolar lavage fluid to pigeon dropping extracts yielded positive results. Computed tomography revealed a radiographic pattern unlike typical UIP. The result of pathological diagnosis of surgical lung biopsy was 'others' or NSIP pattern. Only one case had pathological findings of granuloma. Four cases had an improved or stable course only offer segregation from bird antigens. The other four cases needed corticosteroids and immunosuppressants, and two of the four cases had a progressive course and died of respiratory failure.

Aged↗
PubMed2005

A molecule that is associated with Toll-like receptor 4 and regulates its cell surface expression.

Toll-like receptors (TLRs) recognize microbial products and induce immune responses. Their subcellular distribution is believed to be optimized for their pathogen recognition. Little is known, however, about molecular mechanisms regulating the subcellular distribution of TLR. Lipopolysaccharide, a principal membrane component of the Gram-negative bacteria, is recognized by the receptor complex consisting of Toll-like receptor 4 (TLR4) and MD-2. We here show that a novel molecule, a PRotein Associated with Tlr4 (PRAT4B), regulates cell surface expression of TLR4. PRAT4B has a signal peptide followed by a mature peptide. PRAT4B is associated with the hypoglycosylated, immature form of TLR4 but not with MD-2 or TLR2. Downregulation of PRAT4B mRNA with small interfering RNA decreased cell surface TLR4 on HEK293 cells. These results suggest a novel mechanism regulating the subcellular distribution of TLR4.

Amino Acid Sequence↗
PubMed2005

Needs and opportunities for research in hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HP) develops after inhalation of many different environmental antigens, causing variable clinical symptoms that often make diagnosis uncertain. The prevalence of HP is higher than recognized, especially its chronic form. Mechanisms of disease are still incompletely known. Strategies to improve detection and diagnosis are needed, and treatment options, principally avoidance, are limited. A workshop recommended: a population-based study to more accurately document the incidence and prevalence of HP; better classification of disease stages, including natural history; evaluation of diagnostic tests and biomarkers used to detect disease; better correlation of computerized tomography lung imaging and pathologic changes; more study of inflammatory and immune mechanisms; and improvement of animal models that are more relevant for human disease.

Adult↗
PubMed2005

Pulmonary exercise testing predicts prognosis in patients with chronic obstructive pulmonary disease.

OBJECTIVE: In patients with chronic obstructive pulmonary disease (COPD), patient age and initial value of forced expiratory volume in 1 second (FEV1) have been considered the most accurate predictors of mortality among the parameters obtained from pulmonary exercise tests. However, few studies have examined the predictive variables of prognosis among exercise parameters in COPD. We therefore attempted to identify the best index for predicting long-term survival in patients with COPD among the cardiopulmonary variables obtained during exercise testing. PATIENTS AND METHODS: Fifty-eight patients with COPD (50 men and 8 women) without hypoxemia at rest or other serious complications performed resting pulmonary function tests followed by a symptom-limited ramp exercise test on a cycle ergometer with breath-by-breath gas analysis and arterial blood gas sampling. RESULTS: After 3,570+/-1,373 days follow-up (mean+/-SD), 21 died because of deaths by respiratory failure. The overall survival rates calculated by the Kaplan-Meier method were 92.9% and 75.8% at 5 years and 10 years, respectively. In univariate Cox hazards analysis, age, FEV1, VC, RV/TLC, VEmax, VO2max, VCO2max, PaO2max, PacO2max, and PaO2 at rest were found to be significant prognostic indices of survival. However, multivariate analysis revealed only FEV1, PaO2max, and age as independent predictors of mortality. In severe COPD patients (FEV1 <50% predicted, n=35), PaO2max and age also correlated with prognosis, whereas FEV1 did not. CONCLUSION: Pulmonary exercise testing is useful in predicting prognosis in patients with COPD.

Aged↗
PubMed2005

[Five cases of female pneumothorax with endometriosis on the blebs].

A part of catamenial pneumothorax is associated with endometriosis. Several cases were reported where CA125 levels were high in blood or pleural effusion. A case of female pneumothorax, the bleb and diaphragm showed positive for CA125, was reported. Additionally in the 5 cases of 6 female pneumothorax, the blebs showed positive for CA125, CD30, progesterone receptor and estrogen receptor. Endometriosis on the blebs was found in 4 of 6 cases by hematoxylin-eosin staining and in 5 of 6 cases by immunostaining. It is suggested that endometriosis on blebs is an origin of female pneumothorax.

Adolescent↗
PubMed2004

CD4+ T cells migrate from airway to bone marrow after antigen inhalation in rats.

BACKGROUND: IL-5-producing T lymphocytes increase in rat bone marrow after inhalational challenge with allergen. OBJECTIVE: To test the hypothesis that T cells migrate from the airways to the marrow, we examined the trafficking of T cells in Brown Norway rats after sensitization and challenge with ovalbumin. METHODS: Purified CD4+ T cells, harvested from cervical lymph nodes of naive and ovalbumin-sensitized donors, were labeled with carboxy fluorescein diacetate succinimidyl ester; 20 x 10(6) cells were placed in the trachea of naive or sensitized recipients under anesthesia, and 18 hours later, animals were challenged with inhaled ovalbumin. Cells were harvested 24 hours later from the bone marrow, bronchoalveolar lavage fluid, lungs, the lung blood pool of cells, lung draining lymph nodes, peripheral blood, and spleen. RESULTS: The number of carboxy fluorescein diacetate succinimidyl ester-positive cells, measured by fluorescence-activated cell sorter, in the bone marrow of ovalbumin sensitized, primed T-cell recipients was higher than either the sham-sensitized, primed T-cell recipients or sham-sensitized, naive T-cell recipients (P < .05). The number of eosinophils in both bone marrow and bronchoalveolar lavage fluid was increased in ovalbumin-sensitized, primed T-cell recipients. The expression of the T-cell chemoattractants eotaxin and IL-16, evaluated by immunohistochemistry, was higher in the bone marrow of ovalbumin-sensitized, primed T-cell recipients. CONCLUSIONS: CD4+ T cells travel from airway to bone marrow after antigen inhalation. The homing of the CD4+ T cells might be facilitated by eotaxin and IL-16 expression in the bone marrow and might contribute to the stimulation of eosinophilopoiesis after airway allergen exposure.

Administration, Inhalation↗
PubMed2004

CD8+ alphabeta T cells can mediate late airway responses and airway eosinophilia in rats.

BACKGROUND: The function of CD8+ T-cell subsets in mediating late allergic responses is incompletely understood. OBJECTIVE: We sought to test the hypothesis that CD8+ alphabeta T cells are proinflammatory in the airways in vivo by using a well-characterized animal model and the technique of adoptive transfer. METHODS: Brown Norway rats were administered CD8 + alphabeta T cells (10 6 ) intraperitoneally purified from lymph node cells of either naive or ovalbumin (OVA)-sensitized rats and were challenged with aerosolized OVA 2 days later. Control rats were sensitized to 100 mug of OVA in Al(OH) 3 subcutaneously or sham sensitized to saline and were OVA challenged 2 weeks later. RESULTS: The OVA-sensitized and OVA-challenged group and the recipients of OVA-primed CD8+ alphabeta T cells had significant late airway responses calculated from lung resistance measured for an 8-hour period after challenge compared with the naive CD8 + alphabeta T cell-transferred group and the sham-sensitized control group. The number of eosinophils in bronchoalveolar lavage fluid increased in the OVA-sensitized group and the OVA-primed CD8+ alphabeta T-cell recipients compared with numbers in the naive CD8+ alphabeta T-cell recipients and the sham-sensitized control group. IL-4 and IL-5 cytokine mRNA expression in bronchoalveolar lavage fluid increased in the OVA-sensitized group and the OVA-primed CD8+ alphabeta T-cell recipients compared with that in the sham-sensitized group. CONCLUSION: We conclude that antigen-primed CD8 + alphabeta T cells might have a proinflammatory role in allergen-driven airway responses in the rat.

Adoptive Transfer↗
PubMed2004

Chronic bird fancier's lung presenting with acute exacerbation due to use of a feather duvet.

A 67-year-old man was admitted due to fever and exertional dyspnea. He used to raise budgerigars and hill mynahs from 1980 to 1988. He was diagnosed as having chronic bird fancier's lung (BFL) based on a positive peripheral lymphocyte proliferation to pigeon serum in 1994. His disease was stable until 2000. Three months before admission he became a daily user of a feather duvet. A chest CT showed newly-developed peribronchial ground-glass opacities and preexisting honeycombing. Inhalation provocation test was positive. Administration of steroids improved his condition. He has been well after refraining from the use of the feather duvet.

Aged↗