PubMed Health⌕ Search

Biomedical subjects

Y Niki

Publications and source records attributed to Y Niki.

At least 19 recordsLinked to original sources
PubMed2002

Seroepidemiology of Chlamydia pneumoniae in Japan between 1991 and 2000.

AIM: To clarify the endemic and epidemic status of Chlamydia pneumoniae in Japan, the incidence of anti-C pneumoniae antibody was evaluated over a period of 10 years. METHOD: Serum samples were collected from 4756 healthy individuals aged 6 months to 88 years (2488 male and 2268 female individuals) between 1991 and 2000. The antibody titre was determined by a microimmunofluorescence test. RESULTS: After stratification by age and sex in each year, distinct peaks with prevalences of 73.3% and 73.0% were noted in 1993 and 1999, respectively. The lowest prevalence rate was seen in 1996 (59.0%). The epidemic cycle has been estimated to be almost six years in this geographical area. CONCLUSIONS: Chlamydia pneumoniae infection is highly endemic in Japan, as it is in Western countries, and there is a year to year variability. Long term studies in Japan are needed to clarify the epidemic occurrence of C pneumoniae infection.

Adolescent↗
PubMed2001

Roles of the anterior cruciate ligament and the medial collateral ligament in preventing valgus instability.

Both the medial collateral ligament (MCL) and the anterior cruciate ligament (ACL) are reported to prevent valgus instability of the knee. In this study, the anatomical mechanisms by which these ligaments prevent valgus instability were experimentally investigated. The valgus rotation angle and the magnitude of the medial joint space opening were measured in six cadaveric knees, using biplanar photography before and after the MCL and/or the ACL were severed. A significant increase in the valgus rotation angle and a large medial joint space opening were observed when the MCL was severed. An increase in the valgus rotation angle was also observed when the ACL was severed, but only a small medial joint space opening was present. The increase in the valgus rotation angle after ACL severance was nearly parallel to the increase in the internal rotation of the tibia. Thus, we concluded that both ligaments function to prevent valgus instability, but that the anatomical reasons for their function are different. The MCL prevents valgus instability by stopping an opening in the medial joint space. The ACL, on the other hand, prevents the internal rotation of the tibia. When the ACL is severed, the internal rotation increases, and causes the valgus rotation angle to also increase, despite the presence of only a small medial joint space opening.

Adult↗
PubMed2001

The 7.5-kb common plasmid is unrelated to the drug susceptibility of Chlamydia trachomatis.

Using a new plaque cloning technique, we obtained unique Chlamydia trachomatis strains, which were confirmed to be free of the 7.5-kb common plasmid and glycogen in inclusions. The inclusions in plasmid-free and glycogen-negative strains were characterized by a target-like bull's eye morphology that appeared with the formation of a central translucent area that began to be seen clearly at 30 h postinoculation. The clear zone was composed of gel materials originating from reticulate bodies (RBs) that were abnormally large in size and irregular in shape, although one could not differentiate the aberrant RBs from normal RBs at early stages of development. The in-vitro susceptibility of these strains to various chemotherapeutic antibiotics was tested by comparison with their parent strains possessing the common plasmid. No difference was detected for any of the antibiotics tested, indicating that the 7.5-kb common plasmid is unrelated to the drug susceptibility of C. trachomatis.

Anti-Bacterial Agents↗
PubMed2001

Comparison of chest X-ray findings and other parameters in acute exacerbation of chronic bronchitis in Japan and the West.

One of the issues concerning harmonization in the development of pharmaceutical products, especially antimicrobials, is discrepancy in the indications to be studied clinically. In particular, it has been very much questioned whether the underlying disease in Western patients diagnosed with acute exacerbation of chronic bronchitis (AECB) is identical with chronic bronchitis in Japan. We assessed chest X-ray films from 105 AECB patients enrolled in a clinical study of SB265805 (a fluoroquinolone antibacterial agent under development) conducted in Europe, and then compared their clinical signs/symptoms and laboratory data with Japanese historical data. Five of the 105 patients did not meet the criteria of AECB; i.e., 2 of them were diagnosed with pneumonia, 1 with bronchiectasis, 1 with pneumoconiosis, and 1 with bronchiectasis plus pulmonary emphysema. In the remaining 100 patients, chest X-ray findings and laboratory test results were consistent with the concept of chronic bronchitis, although 23 of them had other cardiac or pulmonary diseases as well. There were significant imbalances in distribution between Western patients and Japanese historical data in terms of age, cough, WBC counts, and C-reactive protein (CRP) levels. Compared with Japanese historical data, Western patients were younger and had a more severe cough, although increases in WBC and CRP were less remarkable. For other variables, i.e., sex, fever, and volume of sputum, no significant difference was detected in distribution. Overall, there was no significant difference between the two groups in regard to disease severity, as assessed by fever, WBC, and CRP.

Adult↗
PubMed2001

Proper use of MR imaging in internal derangement of the knee (orthopedic surgeon's view).

MR imaging of the knee is a highly accurate examination in terms of the detection of meniscal tears and cruciate ligament ruptures among internal derangement of the knee. The overall accuracy in more than 2000 published cases reached nearly as high as 90% in meniscal tears, and 94% in anterior cruciate ligament (ACL) and 99% in posterior cruciate ligament (PCL) ruptures. Furthermore, the negative predictive value of the knee MR imaging, the number of true negative examination results divided by the numbers of true negative plus false-negative examination results, reaches almost 100% because of its very low false-negative rate. Therefore, from the orthopedic surgeon's point of view, even though the medical cost becomes a great concern, MR imaging has prime importance in the diagnosis of the internal derangement of the knee.

Anterior Cruciate Ligament Injuries↗
PubMed2001

In vitro activity of telithromycin, a new ketolide, against Chlamydia pneumoniae.

The in vitro activity of telithromycin, a new ketolide, was compared with those of roxithromycin, azithromycin, clarithromycin and erythromycin A against 20 strains of Chlamydia pneumoniae. The MICs and minimal chlamydiacidal concentrations of telithromycin for the 20 C. pneumoniae strains both ranged between 0.031 and 0.25 mg/L. Telithromycin was twice as active as roxithromycin, azithromycin and erythromycin A, but less active than clarithromycin. These results appear to indicate that telithromycin is an effective antibiotic that should play some role in the treatment of respiratory tract infections caused by C. pneumoniae.

Anti-Bacterial Agents↗
PubMed2001

A nested PCR assay to detect DNA in sera for the diagnosis of deep-seated trichosporonosis.

Deep-seated trichosporonosis caused by Trichosporon asahii has a high mortality rate and a very poor prognosis. New species-specific oligonucleotide primers for T. asahii were developed from a sequence analysis of rRNA genes that included the internal transcribed spacer regions. A nested PCR assay with specific primers was used to examine 11 serum samples from 7 patients, who were diagnosed with deep-seated trichosporonosis histologically at autopsy. In addition, Trichosporon cell wall polysaccharide (PS) was detected by a latex agglutination (LA) test. Of 11 samples, seven had a positive LA test, and T. asahii DNA was also detected with the nested PCR assay. Of the four samples in which PS antigen was not detected, the nested PCR of two samples was positive. Our new nested PCR assay may be used as an adjunct to conventional methods for diagnosing T. asahii infection.

Adolescent↗
PubMed2001

[Outbreak of measles in a hospital and measures taken against hospital infection--evidence of cost and benefits].

In Japan, an isolated vaccine of measles is used because MMR vaccines have been suspended due to the frequent occurrence of aseptic meningitis after their use. It is administered only once with the cover rate having been approximately 70%. An outbreak of measles was experienced in eight of our health care workers (three doctors, three nurses and two clerks of our hospital) and in seven of our medical students, accompanying local outbreaks. Their condition was severe enough to require admission to our school hospital. One of medical students developed encephalitis, but he has recovered completely. The social cost including medical cost per worker was approximately yen 500,000 (about $4,500). We measured antibodies against measles, rubella, chickenpox and mumps using the ELISA assay in 1048 health care workers less than 40 years of age and 99 medical students before their clinical practice two or three months after the outbreak. The cost including the measuring of antibodies and vaccination for these workers and students was approximately yen 2,800,000 and it will be yen 700,000 for new workers each year. The negative rates for workers were 1.2% for measles, 8.8% for rubella, 10.0% for mumps and 2.0% for chickenpox and those for the medical students were 1.0%, 22.0%, 9.0% and 5.0%, respectively. Of the workers, 9.6% who had more than the defined very high tiaer were thought to have subclinical reinfection because they were non-symptomatic. The rates were 1.2% for rubella, 0.5% for chickenpox and 0.0% for mumps for more than the defined high titers among the workers, suggesting a risk of outbreaks in the future. Therefore, the antibodies of health care workers and medical students should be measured at the hospital and the antibody-negative person should be vaccinated to prevent infection not only from their patients but also prevent other patients from becoming infected by contracted health care workers or students.

Adult↗
PubMed2001

In vitro and in vivo activities of sitafloxacin against Chlamydia spp.

The in vitro and in vivo antichlamydial activity of sitafloxacin was investigated. The MICs and minimal chlamydiacidal concentrations of sitafloxacin for various species of chlamydia ranged from 0.031 to 0.125 microg/ml. Sitafloxacin had an excellent therapeutic effect on experimental Chlamydia psittaci pneumonia and was more potent than tosufloxacin, ofloxacin, and ciproflxacin, although slightly less potent than sparfloxacin.

Animals↗
PubMed2001

Macrophage- and neutrophil-dominant arthritis in human IL-1 alpha transgenic mice.

To study the effects of IL-1 alpha in arthritis, we generated human IL-1 alpha (hIL-1 alpha). Transgenic mice expressed hIL-1 alpha mRNA in various organs, had high serum levels of hIL-1 alpha, and developed a severe polyarthritic phenotype at 4 weeks of age. Not only bone marrow cells but also synoviocytes from knee joints produced biologically active hIL-1 alpha. Synovitis started 2 weeks after birth, and 8-week-old mice showed hyperplasia of the synovial lining layer, the formation of hyperplastic synovium (pannus) and, ultimately, destruction of cartilage. Hyperplasia of the synovial lining was due to the accumulation of macrophage-like cells expressing F4/80 molecules. hIL-1 alpha was widely distributed in macrophage- and fibroblast-like cells of the synovial lining cells, as well as synovial fluid monocytes. T and B cells were rare in the synovial fluid, and analysis of marker expression suggests that synoviocytes were directly histolytic and did not act as antigen-presenting cells. In the joints of these mice, we found elevated levels of cells of the monocyte/macrophage and granulocyte lineages and of polymorphonuclear neutrophils (PMNs), most of which expressed Gr-1, indicating that they were mature, tissue-degrading PMNS: Cultured synoviocytes and PMNs from these animals overexpress GM-CSF, suggesting that the hematopoietic changes induced by IL-1 and the consequent PMN activation and joint destruction are mediated by this cytokine.

Animals↗
PubMed2001

Prevalence of asymptomatic infection with Chlamydia pneumoniae in subjectively healthy adults.

STUDY OBJECTIVE: To investigate the prevalence of asymptomatic infection with Chlamydia pneumoniae in subjectively healthy adults. DESIGN: Prospective study. SETTING: Kawasaki Medical School Hospital in Kurashiki, Japan. PARTICIPANTS: Total of 1,018 asymptomatic healthy adults (age range, 22 to 50 years; mean age, 32.4 years; 482 men and 536 women). MEASUREMENTS AND RESULTS: Nasopharyngeal swab specimens were obtained from all subjects and analyzed by isolation in cell cultures and polymerase chain reaction (PCR) test for C pneumoniae. Serum samples were also obtained and tested for C pneumoniae-specific antibodies by the microimmunofluorescence test. Of 1,018 specimens tested, 14 specimens (1.4%) were judged positive by culture and/or the PCR. Thirteen specimens were PCR positive, and 4 specimens were culture positive. There were three specimens positive by both tests and 11 specimens positive with discrepancies in culture and PCR results. None of the individuals met the serologic criteria for acute infection. Of 1,018 sera tested, 64.1% of men and 58.0% of women had antibody to C pneumoniae. The overall prevalence of antibody was 60.9%. Forty individuals (3.9%) had an IgG titer of > or = 1:512 or IgM titer of > or = 1:16. CONCLUSIONS: Our data suggest that asymptomatic infection with C pneumoniae may occur in subjectively healthy adults.

Adult↗
PubMed2001

[A discrepancy in the values of serum (1-3)-beta-D-glucan measured by two kits using different methods].

The measurement of serum (1-3)-beta-D-glucan (beta-glucan) in cases with deep seated mycosis is a useful diagnostic method. Beta-glucan has usually been measured using two different methods: by an alkali treatment, chromogenic automated kinetic assay (chromogenic assay), and by detergent dilution and heating methods, kinetic turbidimetric assay (turbidimetric assay). However, there are often large discrepancies in the beta-glucan values measured by these two methods. In this study, we reexamined the values of beta-glucan obtained by the two techniques, using 343 serum samples from 146 patients who had been treated in Kawasaki Medical School between January 1999 and May 1999, and then analyzed the reasons for the differences. Serum beta-glucan results measured were evaluated by segregating them into three clinical categories: cases with proven deep mycosis, cases with probable deep mycosis and cases without deep mycosis. In addition, the beta-glucan in the samples was suppressed by carboxy-methylated curdlan (CM-curdlan), and then was remeasured to find a non-specific reaction. Although a certain correlation was found between the serum beta-glucan results measured by the two methods, the values measured by the chromogenic assay were, in general, higher than those measured by the turbidimetric assay. There were also many samples in the cases without deep mycosis that showed positive values with the chromogenic assay, but not with the turbidimetric assay. With the turbidimetric assay, the addition of CM-curdlan suppressed the values of beta-glucan in all samples; however, when measured by the chromogenic assay the values in many samples remained high. These results suggest that a non-specific reaction which did not include beta-glucan was detected by the chromogenic assay. Further studies are needed to evaluate the characteristics and comparable usefulness of the two assays.

Adult↗
PubMed2001

[Fundamental and clinical studies on beta-lactamase inhibitors].

Cluvulanic acid and sulbactam have been widely used in Japan as beta-lactamase inhibitors, and we will soon have tazobactam, the third beta-lactamase inhibitor. It will be available in combination with piperacillin(1:4), and expected excellent clinical efficacy in various infection, caused by class A, class D and class C beta-lactamase producing bacteria, including ESBLs producing gram negatives. The clinical usefulness of tazobactam/piperacillin might be exceeded those of drugs which combined with cluvulanic acid and sulbactam. However, it dose not inhibit class B beta-lactamase and large amount of class C beta-lactamase. There are some reports of newer beta-lactamase inhibitors, which show much more strong activities against class C or even against class B beta-lactamase in fundamental studies. Continuous studies will be needed to these agent for the future clinical use.

Adult↗
PubMed2001

[Atelectasis of the right lower lobe in association with bronchiolitis obliterans organizing pneumonia].

A 58-year-old woman with underlying rheumatoid arthritis was admitted to the hospital because of a dry cough and the presence of an abnormal shadow in the right lower lung field. Consolidation and volume loss in the right lower lobe with air bronchogram were recognized on a chest tomogram. Bronchofiberscopic examination disclosed neither stenosis nor tumors in the large bronchi. Organizing pneumonia was recognized pathologically in transbronchial lung biopsy (TBLB) specimens. The volume of the right lower lobe decreased rapidly, and new infiltration shadows appeared in the right upper and middle lobes. Another bronchofiberscope examination revealed organizing pneumonia, and macrophage infiltrations were seen in the alveoli on histopathological examination of the TBLB specimens. The diagnosis of RA-associated BOOP was made on the basis of agreement of the expansion of the shadows on chest radiographs, the RA symptoms and the RA factor. The patient was treated with prednisolone, and the clinical course was satisfactory, with no recurrence. This case was of interest because BOOP inducing lobar cicatricial atelectasis is very rare.

Anti-Inflammatory Agents↗
PubMed2001

[A case of Coxiella burnetii pneumonia in an adult].

A 49-year-old man visited our hospital complaining of a continuous high-grade fever and cough which had appeared during his stay in Indonesia. He was admitted on the same day because his laboratory data showed marked inflammatory changes and his chest radiograph revealed an infiltrative shadow in the right upper lung field. Initial treatment with beta-lactams was not effective and both his symptoms and his chest radiograph worsened. However, treatment with erythromycin clearly had an effect. Then, we carried out several tests for detection of atypical pathogens including Mycoplasma and Chlamydia. Finally, the case was diagnosed as one of Coxiella burnetii pneumonia because the DNA of C. burnetii was detected from his sera and seroconversion of C. burnetii--specific antibody was observed among paired serum samples. C. burnetii is one of the most commonly recognized pathogens among community-acquired pneumonias in Western countries, but in Japan, reports of community-acquired C. burnetii pneumonia have been rare. This difference may be due to the features of Q fever, in which there are large differences in frequency and form from country to country and among areas of the same country. Surveillance of C. burnetii pneumonia in Japan and different area will be required.

Anti-Bacterial Agents↗
PubMed2001

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1999)].

From October 1999 to September 2000, we collected the specimen from 430 patients with lower respiratory tract infections in 17 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and antibiotics and patients' characteristics. Of 515 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in inflammation, 506 strains were investigated. The breakdown of the isolated bacteria were: Staphylococcus aureus 78, Streptococcus pneumoniae 101, Haemophilus influenzae 104, Pseudomonas aeruginosa (non-mucoid) 58, P. aeruginosa (mucoid) 11, Moraxella subgenus Branhamella catarrhalis 41, Klebsiella pneumoniae 18, etc. Of 78 S. aureus strains, those with 4 micrograms/ml or above of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) occupied 57.7%. Vancomycin and arbekacin showed the most potent activities against MRSA without detection of ABK-resistant strain (MIC: 64 micrograms/ml) and decrease of VCM-sensitive strains those were found in 1998. The frequency of S. pneumoniae exhibiting low sensitivity to penicillin (penicillin-intermediate S. pneumoniae: PISP + penicillin-resistant S. pneumoniae: PRSP) decreased to 34.7% from 46.0% in 1998. The frequency of PRSP was 3.0%, being the least number after 1991. Carbapenems showed strong activities against S. pneumoniae. Especially, panipenem inhibited the growth of all 101 strains with MIC of 0.063 microgram/ml. Generally, all drugs showed strong activities against H. influenzae with MIC80s of 4 micrograms/ml or below. MICs of ofloxacin ranged between 0.063 microgram/ml and 4 micrograms/ml in 1998, however, those were 0.125 microgram/ml or below in all H. influenzae in 1999 showing the strongest activity. Tobramycin and ciprofloxacin showed strong activities against P. aeruginosa (both mucoid and non-mucoid) with MIC80s of 1 microgram/ml. Number of isolated P. aeruginosa (mucoid) was little as 11, however, the susceptibilities to all drugs were better than P. aeruginosa (non-mucoid). K. pneumoniae showed good susceptibilities to all drugs except for ampicillin with decreasing of low-sensitive strains compared to those detected in 1998. Also, all drugs generally showed strong activities against M. (B.) catarrhalis. MIC80s of all drugs were 2 micrograms/ml or below. The drug which showed the strongest activity was imipenem inhibiting all 41 strains with MIC of 0.063 microgram/ml. On the patients' characteristics, the number of patients aged 80 years or older who had been increased was decreased in 1999 in the distribution by age. The percentage of the elderly patients aged 70 years or older was 47.0%, which occupied almost a half number of the total patients as in the last year. As for the incidence by disease, bacterial pneumonia and chronic bronchitis were the highest. They were noted in 37.9% and 30.5% of the patients, respectively. In 1999, bronchial asthma was frequently observed as compared in recent years. It was noted in about 10% of the patients which is the same % as in bronchiectasis. We examined the number of strains from these patients with infections before and after administration of antibiotics. In patients with bacterial pneumonia, the number of isolated strains was almost the same between those before and after administration. However, in patients with chronic bronchitis, the number of strains remarkably decreased to less than the half of the total after administration of antibiotics in the last year, but it decreased to 2/3 of the total in 1999. On the administration of antibiotics and isolated bacteria by the day of administration, the bacteria which were isolated more before administration were H. influenzae in 28.4%, S. pneumoniae in 25.7%, M. (B.) catarrhalis in 12.0% and S. aureus in 10.6%. The frequency of S. aureus after administration over 15 days was almost the same as that before administration, but the frequency of P. aeruginosa (both mucoid and non-mucoid) was 36.8% which was higher than that before administration. The frequency of isolated S. pneumoniae was decreased after administration and none of them was isolated after completion of administration. However, that of H. influenzae was decreased to 7.1% after administration within 3 days, and many H. influenzae were isolated after completion of administration as 21.4%.

Adolescent↗
PubMed2001

[A case of disseminated intravascular coagulopathy (DIC) and multiple organ failure (MOF) after ingestion of hydrochloric acid].

Ingestion of caustic materials causes systemic damages and requires treatment in an intensive care unit. This report presents a case of disseminated intravascular coagulopathy (DIC) and multiple organ failure after ingestion of hydrochloric acid in an attempted suicide. The patient was admitted to the emergency ward within 1 hr after ingestion of 60 ml of 35% hydrochloric acid. Initial blood examination suggested hemolysis without anemia or thrombocytopenia. Arterial blood gas analysis exhibited evident metabolic acidosis with hypoxia. Two hours after ingestion, severe hemolysis, anemia, thrombocytopenia emerged with abnormal results from clotting and fiblinolysis tests, and a diagnosis of DIC was made. Subsequently, conjugate deviation and severe bleeding diathesis appeared. No evidence for gastrointestinal bleeding and brain hemorrhage was obtained in our abdominal echography and brain computed tomography, respectively. In spite of vigorous suppurative therapy including transfusion of blood, fresh frozen plasma, and catecholamines, the patient expired 29 hrs after ingestion. Autopsy was not carried out. Rapid progressive DIC as an acute complication of acid ingestion must be born in mind.

Acidosis↗