Exosome-mediated small interfering RNA delivery inhibits aberrant osteoblast differentiation in Apert syndrome model mice

OBJECTIVE

Apert syndrome, an autosomal dominant congenital disorder characterized by craniosynostosis, is caused by a missense mutation (S252W or P253R) in fibroblast growth factor receptor 2 (FGFR2). Exosomes are naturally occurring carriers that deliver nucleic acids, including small interfering RNA (siRNA), to induce gene silencing. This study aimed to develop siRNA-loaded exosomes (Ex-siRNA^Fgfr2S252W) to silence the Fgfr2^S252W gain-of-function mutation, thereby inhibiting the increased osteoblastic differentiation caused by the constitutive activation of FGFR2 signaling in calvarial osteoblastic cells isolated from Apert syndrome model mice.

DESIGN

Primary calvarial osteoblast-like cells were isolated from the embryonic calvarial sutures of the Apert syndrome model (Fgfr2^S252W/+) and littermate wild-type mice (Ap-Ob and Wt-Ob, respectively). Exosomes were extracted from the serum of wild-type mice, validated using biomarkers, and used to encapsulate siRNAs. After exosome-mediated siRNA transfection, cells were analyzed under a fluorescence microscope to validate the delivery of Ex-siRNA^Fgfr2S252W, followed by western blot and real-time reverse transcription polymerase chain reaction analyses.

RESULTS

After 24 h of Ex-siRNA^Fgfr2S252W delivery in both Ap-Ob and Wt-Ob, siRNA-loaded exosome delivery was validated. Moreover, p44/42 mitogen-activated protein kinase (MAPK) phosphorylation, runt-related transcription factor 2 (Runx2), and collagen type 1 alpha 1 (Col1a1) mRNA expression, and alkaline phosphatase (ALP) activity were significantly increased in Ap-Ob. The levels of phospho-p44/42 protein, Runx2, Col1a1, and ALP were significantly decreased after Ex-siRNA^Fgfr2S252W transfection but did not affect Wt-Ob.

CONCLUSIONS

These results indicate that exosome-mediated delivery of siRNA targeting Fgfr2^S252W is a potential non-invasive treatment for aberrant FGF/FGFR signaling.

Changes in superoxide dismutase 3 (SOD3) expression in periodontal tissue during orthodontic tooth movement of rat molars and the effect of SOD3 on in vitro hypoxia-exposed rat periodontal ligament cells

BACKGROUND/OBJECTIVES

Hypoxia during orthodontic tooth movement (OTM) induces reactive oxygen species (ROS) production in periodontal tissues. Superoxide dismutase 3 (SOD3) is an anti-inflammatory enzyme that protects cells from ROS. This study investigated the expression and function of SOD3 during rat OTM and in hypoxia-exposed rat periodontal ligament (PDL) cells.

MATERIALS/METHODS

OTM of right maxillary first molars were performed in 8-week-old male Sprague-Dawley rats using closed-coil spring for 1 and 14 days (n = 6 per group). SOD3 and hypoxia-inducible factor 1-alpha (HIF-1α) protein expression was evaluated by immunohistochemistry. The effects of SOD3 on cell viability and proliferation, ROS production, and mRNA expression of Hif1-α, receptor activator of nuclear factor kappa-Β ligand (Rankl), and osteoprotegerin (Opg) in PDL cells and osteoclast differentiation were investigated under normal and hypoxic conditions.

RESULTS

SOD3 expression in PDL tissues significantly decreased on the compression side on day 1 and on both sides on day 14 of OTM. HIF-1α levels significantly increased on the compression side on day 14. Cell viability, cell proliferation, and Opg mRNA expression decreased, whereas ROS production and Hif1-α and Rankl mRNA expression increased in the PDL cells upon SOD3 silencing. Hypoxia reduced Sod3 and Opg mRNA expression and increased ROS, Rankl mRNA expression, and osteoclast formation; SOD3 treatment attenuated these effects.

CONCLUSION/IMPLICATIONS

SOD3 plays a role in periodontal tissue remodelling during OTM and in hypoxia-exposed PDL cells through ROS, HIF-1α, and RANKL/OPG pathways. Moreover, SOD3 treatment could attenuate the negative effects of hypoxia on the PDL cells.

Expression pattern of transcriptional enhanced associate domain family member 1 (Tead1) in developing mouse molar tooth

The Hippo pathway is essential for determining organ size by regulating cell proliferation. Previous reports have shown that impairing this pathway causes abnormal tooth development. However, the precise expression profile of the members of the transcriptional enhanced associate domain family (Tead), which are key transcription factors mediating Yap function, during tooth development is unclear. In this study, among the four isoforms of Tead (Tead1 - 4), only the expression of Tead1 mRNA was observed using semiquantitative RT- PCR in murine developing tooth germ at E16.5. The expression level of Tead1 mRNA in the excised murine mandibular molar tooth germ was significantly higher at E16.5 than at other developmental stages, as determined using quantitative PCR. We found that the mRNA expression of connective tissue growth factor (Ctgf), which is one of the Yap target genes directly controlling cell growth, changed consistently with that of Tead1 in developing molars. Fluorescent immunostaining revealed that Tead1 protein was expressed in both epithelial cells and mesenchymal cells of the dental lamina and dental epithelium, including the primary enamel knot during the cap stage. During the early bell stage (E16.5), Tead1 was expressed intensely in the inner and outer enamel epithelium, including the secondary enamel knot and the neighboring mesenchymal cells. Tead1 then specifically localized to the inner and outer enamel epithelium, which is responsible for enamel formation during the bell stage. These expression patterns were consistent with those of Yap, Taz, and Ctgf protein in developing molars. These results suggest that Tead1 acts as a mediator of the biological functions of Yap, such as the morphogenesis of cusp formation, during tooth development.

Inhibitory effects of miRNAs in astrocytes on C6 glioma progression via connexin 43

In many types of tumor cells, cell communication via gap junction is decreased or missing. Therefore, cancer cells acquire unique cytosolic environments that differ from those of normal cells. This study assessed the differences in microRNA (miRNA) expression between cancer and normal cells. MicroRNA microarray analysis revealed five miRNAs that were highly expressed in normal astrocytes compared with that in C6 gliomas. To determine whether these miRNAs could pass through gap junctions, connexin 43 was expressed in C6 glioma cells and co-cultured with normal astrocytes. The co-culture experiment showed the possibility that miR-152-3p and miR-143-3p propagate from normal astrocytes to C6 glioma in connexin 43-dependent and -independent manners, respectively. Moreover, we established C6 glioma cells that expressed miR-152-3p or miR-143-3p. Although the proliferation of these miRNA-expressing C6 glioma cells did not differ from that of empty vectors introduced in C6 glioma cells, cell migration and invasion were significantly decreased in C6 glioma cells expressing miR-152-3p or miR-143-3p. These results suggest the possibility that miRNA produced by normal cells attenuates tumor progression through connexin 43-dependent and -independent mechanisms.

Is greater than 145{degrees} of deep knee flexion under weight-bearing conditions safe after total knee arthroplasty?: a fluoroscopic analysis of Japanese-style deep knee flexion

We investigated the characteristics of patients who achieved Japanese-style deep flexion (seiza-sitting) after total knee replacement (TKR) and measured three-dimensional positioning and the contact positions of the femoral and tibial components. Seiza-sitting was achieved after surgery by 23 patients (29 knees) of a series of 463 TKRs in 341 patients. Pre-operatively most of these patients were capable of seiza-sitting, had a lower body mass index and a favourable attitude towards the Japanese lifestyle (27 of 29 knees). According to two-/three-dimensional image registration analysis in the seiza-sitting position, flexion, varus and internal rotation angles of the tibial component relative to the femoral component had means of 148° (SD 8.0), 1.9° (SD 3.2) and 13.4° (SD 5.9), respectively. Femoral surface contact positions tended to be close to the posterior edge of the tibial polyethylene insert, particularly in the lateral compartment, but only 8.3% (two of 24) of knees showed femoral subluxation over the posterior edge. The mean contact positions of the femoral cam on the tibial post were located 7.8 mm (sd 1.5) proximal to the lowest point of the polyethylene surface and 5.5 mm (SD 0.9) medial to the centre of the post, indicating that the post-cam contact position translated medially during seiza-sitting, but not proximally. Collectively, the seiza-sitting position seems safe against component dislocation, but the risks of posterior edge loading and breakage of the tibial polyethylene post remain.

A double-blind comparative study of the safety and efficacy of caspofungin versus micafungin in the treatment of candidiasis and aspergillosis

The safety and efficacy profile of caspofungin and micafungin in Japanese patients with fungal infections were directly compared in this prospective, randomized, double-blind study. The proportion of patients who developed significant drug-related adverse event(s) (defined as a serious drug-related adverse event or a drug-related adverse event leading to study therapy discontinuation) was compared in 120 patients [caspofungin 50 mg, or 50 mg following a 70-mg loading dose on Day 1 (hereinafter, 70/50 mg) group: 60 patients; micafungin 150 mg: 60 patients]. The overall response rate was primarily evaluated in the per-protocol set (PPS) population. The proportion of patients who developed significant drug-related adverse events was 5.0 % (3/60) in the caspofungin group and 10.0 % (6/60) in the micafungin group [95 % confidence interval (CI) for the difference: -15.9 %, 5.2 %]. The favorable overall response in the PPS population for patients with esophageal candidiasis, invasive candidiasis, and chronic pulmonary aspergillosis including aspergilloma was 100.0 % (6/6), 100.0 % (3/3), and 46.7 % (14/30) in the caspofungin group, and 83.3 % (5/6), 100.0 % (1/1), and 42.4 % (14/33) in the micafungin group, respectively. In Japanese patients with Candida or Aspergillus infections, there was no statistical difference in the safety between caspofungin and micafungin. Consistent with other data on these two agents, the efficacy of caspofungin and micafungin was similar.

Linezolid versus vancomycin for the treatment of infections caused by methicillin-resistant Staphylococcus aureus in Japan

OBJECTIVES

To compare the efficacy and safety of linezolid and vancomycin for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in Japan.

METHODS

Patients with nosocomial pneumonia, complicated skin and soft-tissue infections or sepsis caused by MRSA were randomized to receive linezolid (600 mg every 12 h) or vancomycin (1 g every 12 h).

RESULTS

One hundred patients received linezolid and 51 received vancomycin with outcomes evaluated at the end of therapy (EOT) and at the follow-up (FU), 7-14 days later. At EOT, clinical success rates in the MRSA microbiologically evaluable population were 62.9% and 50.0% for the linezolid and vancomycin groups, respectively; and microbiological eradication rates were 79.0% and 30.0% in the two groups, respectively (P < 0.0001). At FU, the clinical success rates were 36.7% for both groups and the microbiological eradication rates were 46.8% and 36.7%, respectively. Reversible anaemia (13%) and thrombocytopenia (19%) were reported more frequently in linezolid patients; laboratory analysis showed mild decrease in platelet counts with full recovery by FU. The mean platelet count in linezolid patients with thrombocytopenia was 101,000/mm(3). Significantly low platelet counts (<50,000/mm(3)) were observed more frequently in patients receiving vancomycin than in linezolid patients (6% versus 3%). Mean changes in haemoglobin levels between the two groups were not different.

CONCLUSIONS

Linezolid is as effective as vancomycin for the treatment of MRSA infections and may be more effective than vancomycin in achieving microbiological eradication. Haematological adverse events were reported more frequently in linezolid-treated patients; analysis of laboratory data showed a mild reversible trend towards lower platelet counts.

[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.

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.

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.

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.

[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.

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.

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.

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.

[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%.

[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.

[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.

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.

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.

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.

[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.

[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.

Seroprevalence of antibodies to Chlamydia spp. in human immunodeficiency virus-infected subjects in Japan

To evaluate the seropositivity of Chlamydia spp. in human immunodeficiency virus (HIV)-infected subjects in Japan, Chlamydia-specific antibodies in sera collected from 106 HIV-infected subjects were measured by the microimmunofluorescence test. The prevalence of C. pneumoniae-specific IgA, C. trachomatis-specific IgG and IgA and mean titers were significantly higher in the homosexual and heterosexual HIV-infected subjects than in the hemophilic patients and HIV-negative controls. These data indicate that the higher C. pneumoniae and C. trachomatis seroprevalence among HIV-infected subjects is probably due to an HIV risk factor, such as promiscuous sexual behavior, rather than to HIV infection itself.

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.

Serum KL-6 as a possible marker for amiodarone-induced pulmonary toxicity

Amiodarone is a useful drug for the treatment of life-threatening cardiac arrhythmias. However, amiodarone can induced pulmonary toxicity (APT) and may cause life-threatening lung damage. APT can be difficult to diagnose, but early diagnosis is important. Here, in a 51-year-old man with APT, the high serum KL-6 level was correlated with the severity of symptoms and chest X-ray findings, and it was inversely correlated with PaO2 and diffusion capacity for carbon monoxide levels. The findings suggest that the serum KL-6 level may be increased in APT and that therefore it's the determination of serum KL-6 may provide a useful indicator and/or monitoring marker of APT. KL-6 is believed to be produced and secreted by type II pneumocytes. Typical pathological findings of APT include proliferation of type II pneumocytes which may produce KL-6, and result in increased serum KL-6 levels.

[Pulmonary suppuration due to a mixed infection of anaerobic bacterium and Actinomyces]

We report a case of pulmonary suppuration due to a mixed infection of anaerobic bacterium and Actimomyces. A 49-year-old man was admitted to our hospital because of hemoptysis on March 30, 1999. A chest X-ray film showed a localized shadow in the right middle lobe, and a tumor shadow was recognized on chest CT. The anaerobic bacterium were isolated from specimens collected bronchofiberscopically. A diagnosis of pulmonary suppuration due to anaerobic bacterium was made, and treatment with sulbactam/ampicillin, followed by imipenem/cilastatin, was initiated. Although his clinical symptoms and laboratory data improved rapidly following this treatment, the abnormal finding on the chest radiographs remained, with only slight improvement. Accordingly, surgical resection of part of the right middle lobe was performed on June 29 using a video-associated thoracic surgery technique. Actinomycosis was recognized by pathological examination of the resected lesion. A revised diagnosis of pulmonary suppuration due to a mixed infection of anaerobic bacterium and Actinomyces was made. Anaerobic bacterium in the oral cavity are recognized as significant pathogens in pulmonary suppuration. In the present case, we considered anaerobic bacterium and Actinomyces aspirated from the oral cavity into the lung to have caused the pulmonary suppuration.

[Comparison of positivity rates for antibodies against measles, rubella, chickenpox and mumps by assays]

Our previous study found mistakes by some doctors in the choice of an assay for determining antibodies in Japan. To compare the positivity rates for antibodies by assays, we measured the antibodies of measles, rubella, chickenpox and mumps from the same sera using such methods as the EIA, HI and CF assays. The subjects were 175 nursing students. The positivity rates for measles, chickenpox and mumps by the EIA assay were 96.6%, 93.7%, and 83.3%, respectively. Those for rubella by the HI and CF assays were 92.0% and 10.1%. The sensitivity rates for measles, chickenpox and mumps by the HI and CF assays, based on the results of the EIA assay, were 75.1%, 102.4% and 69.2% in the HI assay, and 20.6%, 38.7% and 8.0% in the CF assay, respectively. Our previous study showed that the sensitivity of the HI assay for rubella antibody is same as that of the EIA assay in Japan. Currently an EIA assay should be chosen for these antibodies and the HI assay or IAHA assay should be possible selections for rubella and chickenpox. However, international comparison of the cutoff titers for these antibodies should be considered.

[Activities of antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. Levofloxacin--Surveillance Group]

The surveillance study was conducted to determine the antimicrobial activity of fluoroquinolones (ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin) and other 20 antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. The resistance to fluoroquinolones was remarkable in Enterococci, methicillin-resistant staphylococci and Pseudomonas aeruginosa from UTI. However, many of the common pathogens such as Streptococcus pneumoniae including penicillin-resistant isolates, methicillin-susceptible Stahylococcus aureus, Moraxella catarrhalis, the family of Enterobacteriaceae, Haemophilus influenzae including ampicillin-resistant isolates have been kept to be susceptible to fluoroquinolones. About 90% of P. aeruginosa isolates from RTI were susceptible to fluoroquinolones. In conclusion, the results from this surveillance study suggest that fluoroquinolones are useful in the treatment of various bacterial infections including respiratory infections.

[Measures against hospital infection for students in medical schools in Japan--a survey by questionnaires]

We sent questionnaires to 80 medical schools in Japan to know what the problems in hospital infection for students in medical schools are. Seventy-one % were sent back to us. There have been hospital infection from patients to students in 12% of the medical schools, included 3 cases each of measles, chickenpox and mumps, 2 cases each of rubella, hepatitis B and tuberculosis. Fourteen % of the medical schools had reports about the past history of infection and vaccination from students, 70% of the schools determined their antibodies and the 28% did nothing. Ninety-three%, 25%, 23%, 18%, and 15%, of the schools determined antibodies for hepatitis B, rubella, measles, chickenpox and mumps, respectively. Some assays of the measurement were low in sensitivity. The cost for the determination was fully paid in 48% of the schools, but only partially supported in 35%. Tuberculin reaction was performed in 40% of the schools and then BCG was done in 57%. Vaccination was recommended in 40% of the schools. The cost of vaccination was all paid in 38% of them, which was only for hepatitis B, and partially supported in 15% of them.

Comparative tolerability of the newer fluoroquinolone antibacterials

The most common adverse effects of the fluoroquinolones involve the gastrointestinal tract, skin and CNS, and are mainly mild and reversible. Of the gastrointestinal events, nausea and vomiting are the most common. Mild hepatic reactions are a class effect, usually presenting as mild transaminase level increases without clinical symptoms. However, postmarketing surveillance has revealed significant hepatotoxicity with trovafloxacin. It is not currently known whether the severe reactions to trovafloxacin are specific to that agent or simply represent an extreme of an emerging class effect. The enormous worldwide usage of, and extensive published adverse effect data on the other fluoroquinolones and naphthyridones suggests the former. In perspective, rare but serious hepatotoxicity has been reported with other fluoroquinolones and the overall incidence of trovafloxacin hepatotoxicity is not dissimilar to that reported with flucloxacillin and amoxicillin-clavulanic acid. CNS reactions vary in severity and include dizziness, convulsions (notably with lomefloxacin) and psychoses. Fluoroquinolones differ in their pro-convulsive activity, relating to their differing potential as gamma-aminobutyric acid antagonists and binding to the N-methyl-D-aspartate receptor. The basis for the increased seizure potential following the coadministration of nonsteroidal anti-inflammatory drugs with certain fluoroquinolones is not fully understood. Fluoroquinolone phototoxicity, caused by the generation of toxic free oxygen species under exposure to UVA radiation, is significantly more common with 8-halogenated compounds. Certain patient groups, e.g. patients with cystic fibrosis, are predisposed to this adverse effect. Murine photocarcinogenicity has been demonstrated with lomefloxacin, but no such effects have been reported in humans. Prolongation of the QTc interval is also a class effect, although cardiac arrhythmias have only been linked with sparfloxacin. Among the newer fluoroquinolones, clinically significant cardiac events are rare or absent but possible interactions in patients receiving other drugs capable of causi ng QT prolongation should be anticipated. Tendinitis and rupture, usually of the Achilles tendon, are rare, class-effects of fluoroquinolones, most frequently reported with pefloxacin. Predisposing factors include aging, corticosteroid use, renal disease, haemodialysis and transplantation. Use of fluoroquinolones in paediatric patients remains contentious. However, accruing human data suggest that restrictions on paediatric use imposed because of fluoroquinolone-induced cartilage damage in juvenile animals, may soon be relaxed. Data from over 1700 children in the UK failed to disclose arthropathy and extensive paediatric use of norfloxacin in Japan and ciprofloxacin in developing countries has been free of articular effects.

Influence of gatifloxacin, a new quinolone antibacterial, on pharmacokinetics of theophylline

The influence of gatifloxacin, a new quinolone antibacterial, on the pharmacokinetics of theophylline (TP) was studied in five healthy adult male volunteers. After 200 mg of TP in sustained-release preparation was administered twice daily for 4 consecutive days, the same dose of TP and 200 mg of gatifloxacin were administered concurrently to the subjects twice daily for 5 consecutive days. Comparison of the pharmacokinetic parameters on day 4 of TP alone, and days 3 and 5 of co-administration revealed no significant differences in the maximum concentrations (Cmax), areas under the serum concentration-time curve (AUC0-12), total body clearances, and the amounts and proportions of TP and its metabolites in urine. One subject, however, showed 55% and 44% increases in Cmax and AUC0-12, respectively, on day 5 of co-administration relative to values on day 4 of TP alone. Thus, co-administration of gatifloxacin seemed to have little effect on the pharmacokinetics of TP. Further studies will be necessary to clarify the pharmacokinetic interaction between quinolones and TP, and it is recommended that, when both gatifloxacin and TP are administered, the background of the patients, such as their age, liver and cardiac functions, and other concomitant medications, be considered.