Sliding friction on ice

We study the friction when rectangular blocks made from rubber, polyethylene, and silica glass are sliding on ice surfaces at different temperatures ranging from -40 to 0 °C, and sliding speeds ranging from 3 μm/s to 1 cm s-1. We consider a winter tire rubber compound both in the form of a compact block and as a foam with ∼10% void volume. We find that both rubber compounds exhibit a similar friction on ice for all studied temperatures. As in a previous study at low temperatures and low sliding speeds, we propose that an important contribution to the friction force is due to slip between the ice surface and ice fragments attached to the rubber surface. At temperatures around 0 °C (or for high enough sliding speeds), a thin pre-melted water film will occur at the rubber-ice interface, and the contribution to the friction from shearing the area of real contact is small. In this case, the dominant contribution to the friction force is due to viscoelastic deformations of the rubber by the ice asperities. The sliding friction for polyethylene (PE) and silica glass (SG) blocks on ice differs strongly from that of rubber. The friction coefficient for PE is ∼0.04-0.15 and is relatively weakly velocity dependent except close to the ice melting temperature where the friction coefficient increases toward low sliding speeds. Silica glass exhibits a similarly low friction as PE for T > -10 °C but very large friction coefficients (of order unity) at low temperatures. For both PE and SG, unless the ice track is very smooth, the friction force depends on the position x along the sliding track. This is due to bumps on the ice surface, which are sheared off by the elastically stiff PE and SG blocks, resulting in a plowing-type of contribution to the friction force. This results in friction coefficients, which locally can be very large ∼1, and visual inspection of the ice surface after the sliding acts show ice wear particles (white powder) in regions where ice bumps occur. Similar effects can be expected for rubber blocks below the rubber glass transition temperature, and the rubber is in the (elastically stiff) glassy state.

Effect of High β-glucan Barley on Postprandial Blood Glucose and Insulin Levels in Type 2 Diabetic Patients

The aim of our study was to investigate whether high β-glucan-containing barley (7.2 g per 100 g) improves postprandial plasma glucose levels and suppresses postprandial insulin levels during a meal tolerance test in type 2 diabetic patients. A meal tolerance test (500 kcal) was conducted using two types of test meals: a test meal with white rice (WR) alone (WR diet) and a test meal with WR mixed with 50% barley (BR diet) as staple food. The side dish was the same in the both meals. The changes in plasma glucose and serum C-peptide immunoreactivity (CPR) levels for 180 minutes after ingestion of the test meals were compared. Ten patients with type 2 diabetes (age 52.5 ± 15.1 years, and 7 males and 3 females) were included in this study. The mean HbA1c level and body mass index were 8.8 ± 1.4%, and 29.7 ± 4.5 kg/m², respectively. Plasma glucose levels after ingestion of the WR diet or BR diet peaked at 60 minutes, which showed no significant differences between the two types of test meals. However, the incremental area under the curve (IAUC) of plasma glucose levels after ingestion of BR diet was significantly lower than that of WR diet. The serum CPR levels at 180 min and their IAUC over 180 minutes after ingestion of BR diet were significantly lower than those of WR diet. Conclusion: Increase in postprandial plasma glucose and insulin levels was suppressed by mixing high-β-glucan barley with WR in type 2 diabetic patients.

Rolling friction of elastomers: role of strain softening

We study the temperature and velocity dependency of rolling friction. Steel and PMMA cylinders are rolled on sheets of nitrile butadiene rubber (NBR), with and without filler, and fluoroelastomer (FKM) with filler. Measurements of the rolling friction are performed for temperatures between -40 °C and 20 °C, and for velocities between 5 μm s^-1 and 0.5 cm s^-1. For the unfilled NBR, a smooth rolling friction master curve is obtained using the bulk viscoelastic frequency-temperature shift factor a_T. For the filled rubber compounds, a small deviation from the bulk viscoelastic shift factor is observed at low temperatures. The experimental data are analyzed using an analytical theory of rolling friction. For the filled compounds, good agreement with theory is obtained when strain softening is included, which increases the rolling friction by a factor ∼2 for the filled FKM and ∼3 for the filled NBR compounds. For the unfilled NBR, the maximum of the rolling friction occurs at higher sliding speeds than predicted by the theory. We discuss the role of the adhesive (crack-opening) contribution to the rolling friction, and the role of frozen-in elastic deformations as the rubber is cooled down below the rubber glass transition temperature.

Effect of High β-glucan Barley on Postprandial Blood Glucose Levels in Subjects with Normal Glucose Tolerance: Assessment by Meal Tolerance Test and Continuous Glucose Monitoring System

The effect of white rice (WR) mixed with high β-glucan-containing barley at 50% on improvement of postprandial blood glucose levels was assessed by meal tolerance test and continuous glucose monitoring (CGM) in 15 healthy subjects with normal glucose tolerance (age 31.6 ± 12.9 years old, 4 males and 11 females). A meal tolerance test (500 kcal) was conducted using 2 types of test meals: a test meal only with WR and a test meal WR mixed 50% barley, and the side dish was the same in both meals. Blood glucose levels of the subjects 180 minutes after ingestion of the test meals were compared. In addition, a CGM device was attached to the subjects for 2 days when the WR or barley as a staple food was provided 3 times a day for consecutive days, and the daily variation of glucose was investigated. The glucose levels 30 minutes after dietary loads and the area under the blood concentration-time curve over 180 minutes were significantly decreased in the barley consumption group. In CGM, 24-hour mean blood glucose and 24-hour standard deviation of blood glucose were also significantly decreased after ingestion of the barley. Postprandial glucose level elevation was suppressed by mixing high-β-glucan barley with WR in subjects with normal glucose tolerance.

Rubber friction: The contribution from the area of real contact

There are two contributions to the friction force when a rubber block is sliding on a hard and rough substrate surface, namely, a contribution F_ad = τ_f A from the area of real contact A and a viscoelastic contribution F_visc from the pulsating forces exerted by the substrate asperities on the rubber block. Here we present experimental results obtained at different sliding speeds and temperatures, and we show that the temperature dependency of the shear stress τ_f, for temperatures above the rubber glass transition temperature T_g, is weaker than that of the bulk viscoelastic modulus. The physical origin of τ_f for T > T_g is discussed, and we propose that its temperature dependency is determined by the rubber molecule segment mobility at the sliding interface, which is higher than in the bulk because of increased free-volume effect due to the short-wavelength surface roughness. This is consistent with the often observed reduction in the glass transition temperature in nanometer-thick surface layers of glassy polymers. For temperatures T < T_g, the shear stress τ_f is nearly velocity independent and of similar magnitude as observed for glassy polymers such as PMMA or polyethylene. In this case, the rubber undergoes plastic deformations in the asperity contact regions and the contact area is determined by the rubber penetration hardness. For this case, we propose that the frictional shear stress is due to slip at the interface between the rubber and a transfer film adsorbed on the concrete surface.

Visualization and automatic detection of defect distribution in GaN atomic structure from sampling Moiré phase

Quantitative detection of defects in atomic structures is of great significance to evaluating product quality and exploring quality improvement process. In this study, a Fourier transform filtered sampling Moiré technique was proposed to visualize and detect defects in atomic arrays in a large field of view. Defect distributions, defect numbers and defect densities could be visually and quantitatively determined from a single atomic structure image at low cost. The effectiveness of the proposed technique was verified from numerical simulations. As an application, the dislocation distributions in a GaN/AlGaN atomic structure in two directions were magnified and displayed in Moiré phase maps, and defect locations and densities were detected automatically. The proposed technique is able to provide valuable references to material scientists and engineers by checking the effect of various treatments for defect reduction.

Clinical evaluation of the QuantiFERON-TB Gold test in patients with non-tuberculous mycobacterial disease

OBJECTIVE

To evaluate the clinical usefulness of the QuantiFERON TB-2G (QFT-2G) test in patients with non-tuberculous mycobacterial (NTM) disease without a previous history of tuberculosis (TB).

METHODS

The study consisted of 214 patients with NTM disease who satisfied the diagnostic guidelines of the American Thoracic Society.

RESULTS

The causative microorganism was Mycobacterium avium in 83 patients, M. intracellulare in 80, M. kansasii in 33, M. marinum in 12, M. szulgai in 3, M. abscessus in 2 and M. chelonei in 1. The positive response rate of QFT-2G test result was 2% in 163 patients with M. avium-intracellulare complex (MAIC) disease, 52% in 33 with M. kansasii disease, 58% in 12 with M. marinum disease, 33% in 3 with M. szulgai disease, 0% in two with M. abscessus disease and 0% in one with M. chelonei disease. The positivity of the QFT-2G test was 52% in patients with NTM disease, thought to be because NTM possesses common M. tuberculosis-specific antigens.

CONCLUSIONS

Although QFT-2G may be a useful diagnostic method to differentiate TB from MAIC disease, there are several problems to be resolved before it can be used as a diagnostic method for NTM disease (M. kansasii disease), including the determination of the positive cut-off level for QFT-2G test.

Clinical evaluation of QuantiFERON TB-2G test for immunocompromised patients

The usefulness of the tuberculin skin test (TST) and the QuantiFERON TB-2G (QFT-TB) test were compared in immunocompromised patients. The subjects consisted of 252 immunocompromised patients who were clinically suspected of tuberculosis (TB) infection between April 2005 and December 2006. Regarding the underlying diseases, 74 subjects had malignant diseases, 72 were undergoing immunosuppressive treatment, 52 had diabetes mellitus, 50 had chronic renal failure and four had HIV infection. While the positive rate of the QFT-TB test for the diagnosis of TB infection (TB disease or latent TB infection) was 78.1%, that of TST for TB infection was 50.0%. The QFT-TB test was significantly better than TST. However, 32 (13%) patients had an indeterminate QFT-TB result. Indeterminate findings were significantly more frequent in patients receiving immunosuppressive treatment (28%), especially with lymphocytopaenia in the peripheral blood, than in those who had other underlying diseases. While TST-positive and QFT-TB test-negative results were recognised in immunocompromised patients with bacille Calmette-Guérin vaccination or nontuberculous mycobacterial disease, TST-negative and QFT-TB test-positive results were recognised in immunocompromised patients with a past history of TB infection. It was concluded that the QuantiFERON TB-2G test is a more useful diagnostic method for tuberculosis infection than tuberculin skin test for immunocompromised patients suspected of tuberculosis disease. However, because the results of the QuantiFERON TB-2G test show an indeterminate response for patients receiving immunosuppressive treatment, especially for those with lymphocytopaenia due to severe underlying diseases, care must be taken in the interpretation of the QuantiFERON TB-2G test for these patients.

90 GERM-LINE TRANSMISSION OF DONOR MITOCHONDRIAL DNA IN NUCLEAR TRANSFER-DERIVED COWS

In embryos derived by nuclear transfer (NT), fusion, or injection of donor cells with recipient oocytes caused mitochondrial heteroplasmy. Previous studies have reported varying patterns of mitochondrial DNA (mtDNA) transmission in cloned calves. Distribution of donor mtDNA found in offspring of NT-derived founders may also vary from donor–host embryo heteroplasmy to host embryo homoplasmy. Here we examined the transmission of mtDNA from NT cows to their progeny. NT cows were originally produced by fusion of enucleated oocytes with Jersey (J) or Holstein (H1) oviduct epithelial cells, or Holstein (H2) or Japanese Black (B) cumulus cells, as previously reported (Goto et al. 1999 Anim. Sci. J. 70, 243–245; Yonai et al. 2005 J. Dairy Sci. 88, 4097–4110; Akagi et al. 2003 Mol. Reprod. Dev. 66, 264–272). Transmission of donor cell mtDNA was analyzed by PCR-mediated single-strand conformation polymorphism (PCR-SSCP) analysis of the mitochondrial D-loop region. Eleven NT founder cows were analyzed, 4 (2 = J-NT, and 2 = H1-NT) of them were heteroplasmic whereas 7 (1 = J-NT, 1 = H1-NT, 2 = H2-NT, and 3 = B-NT) were homoplasmic for the host embryo mitochondria. The proportions of donor mtDNA detected in one J-NT cow was 7.7%, and those of other cow lineages were &lt;2%. Heteroplasmic NT cows delivered a total of 9 progeny. Four of the 9 progeny exhibited heteroplasmy with high percentages of donor cell mtDNA populations (52%, 37%, 17%, and 43%). The other 5 progeny were obtained from heteroplasmic NT cows, and all samples of the 10 progeny obtained from the homoplasmic NT cows did not harbor detectable donor cell mtDNA. A genetic bottleneck in the female germ-line will generally favor the transmission of a single mitochondrial population, leading to a return to homoplasmy. Thus, some of progeny maintained heteroplasmy with a higher ratio than that of their NT mothers, which may also reflect a segregation distortion caused by the proposed mitochondrial bottleneck. These results demonstrated that donor mtDNA in NT cows could be transmitted to progeny with varying efficiencies, in a lineage-specific fashion.

Perfectly Straight Nanowires of Fullerenes Bearing Long Alkyl Chains on Graphite

Fullerene derivatives bearing long alkyl chains epitaxially adsorb on the basal plane of graphite forming well-ordered one-dimensional lamellae. Within the lamellae, the C60 moieties are organized in a zigzag-type fashion. The ordering is mainly governed by the substitution pattern and chain length of the alkyl chains. The electrochemical activity of the C60 groups is fully maintained in the surface-confined assemblies.

Growth, Reproduction, and Lactation in Somatic Cell Cloned Cows with Short Telomeres

We previously showed that telomere lengths of 10 somatic cell cloned cows were significantly shorter than normal. In this study, we investigated growth, reproduction, and lactation in these animals to determine if shortened telomeres have any effect on these characteristics. Six Holstein and 4 Jersey cloned cows, derived from oviduct cells, were reared under general group feeding. Body weights were recorded from birth to 48 mo of age. A number of reproductive characteristics were screened during the prepubertal, postpubertal, and postpartum periods. After parturition, milk yields were recorded daily and percentages of milk fat, proteins, and solids-not-fat were measured at monthly intervals. These data were used to estimate production of milk components over a 305-d period. Overall, the cloned heifers exceeded standard growth rates for each breed. The cows were inseminated at the first estrus after they reached 450 d of age, and delivered normal calves except for one stillbirth in the Holstein group. They were inseminated at postpartum estrus to provide second and third parturitions and, again, these pregnancies were normal. Gestational periods and birth weights of the calves were both within the normal range. The average total milk yield per cow in Holstein group clones was less than that of the original cow, whereas Jersey group clones showed a higher average milk yield than the original cow. In both groups of cloned cows, inter-individual variation in milk production was relatively large; however, the coefficient of variation was less than 10%. Our results suggest that the cloned cows have normal growth, reproductive, and lactation characteristics, and thus normal productivity, despite having reduced telomere lengths.

Highly ordered thin films prepared with octabutoxy copper phthalocyanine complexes

Langmuir-Blodgett (LB) films of copper (II) 1,4,8,11,15,18,22,25-octabutoxyphthalocyanine, nCuPc(OBu)(8), (non-peripheral substitution) and copper (II) 2,3,9,10,16,17,23,24-octabutoxyphthalocyanine, pCuPc(OBu)(8), (peripheral substitution), were fabricated and characterized by optical spectroscopy and scanning probe microscopy. The LB films were transferred onto hydrophilic substrates by vertical dipping. Although they posses relatively short polar substituents both compounds form smooth, uniform, dense, and highly stable LB monolayers composed of linear arrays of cofacial oligomers. The long range discotic assemblies of LB and spun cast films of pCuPc(OBu)(8) and nCuPc(OBu)(8) posses physical and chemical properties favorable for molecular electronic device application.

Chlamydia pneumoniae infection associated with enhanced MRI spinal lesions in multiple sclerosis

Cerebrospinal fluid (CSF) from 66 patients with multiple sclerosis (MS) and 25 patients with other neurological diseases (OND) were examined for the infection of Chlamydia pneumoniae by culture, polymerase chain reaction (PCR) assay, and determination of antibodies to C. pneumoniae. PCR was positive not only in 9 of 28 (32%) patients with MS but also in 2 patents with inflammatory disorders in 15 (13%) OND controls (p = 0.18). Viable C. pneumoniae was isolated from one patient with MS and one with paraneoplastic encephalomyelitis. C. pneumoniae could be detected only in cell-containing CSF. In MS, enhanced spinal magnetic resonance imaging (MRI) lesions were detected in all of four PCR-positive patents but none of five PCR-negative patients, and the difference was significant (p = 0.0079). However, no correlation was found between enhanced brain MRI lesions and CSF C. pneumoniae DNA. Elevated titers of anti-C. pneumoniae IgG were detected in CSF in 13 of 66 (20%) patients with MS and 1 of 25 (4%) OND controls (p = 0.064). CNS C. pneumoniae infection is not uncommon in MS as well as in other inflammatory disorders of the nervous system. The association of active spinal lesions with Chlamydia in CSF collected by lumber puncture suggests the detection of a recent infection. On the other hand, the lack of association of active MS brain lesions with CSF Chlamydia and the presence of PCR-positive patents who are clinically stable and have no enhancing MRI lesions imply the existence of a chronic infectious process.

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.

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.

[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.

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.

[Clinical features of myelitis in patients with atopic symptoms]

It is rare to see atopic symptoms in patients with multiple sclerosis(MS). However, it has been reported that in atopic patients, particularly in patients with atopic dermatitis, a benign myelitis occasionally occurs. In the present report, three atopic patients with myelitis were studied clinically and neuroradiologically. All the patients were adult men(Case 1, 2, and 3 were 41-year-old, 31-year-old, and 34-year-old, respectively), and all of them had bronchial asthma without histories of atopic dermatitis. Their manifestations were not severe and were only numbness of upper and/or lower extremities. There was no motor weakness, ataxia, or urinary incontinence. MRI studies revealed a T2-high intensity lesion in the high cervical spinal cord in the two patients(Case 2 and 3) and a T2-high intensity lesion in the lumber spinal cord in the remaining patient(Case 1). Their clinical courses were essentially all benign and well responsive to steroid therapy. Although myelitis of these patients may be a first attack of MS, their findings appear to support a recently emerging concept of the atopic myelitis.

[Anosognosia for hemiplegia in a patient with pontine infarction]

We report a patient with anosognosia for hemiplegia associated with a right pontine infarction. A 51-year-old woman with histories of hypertension and diabetes mellitus was admitted because of weakness of her left upper and lower extremities. On neurologic examination, she was alert and oriented without dementia. Visuospatial hemineglect was not present. Hemiparesis of her left upper and lower extremities was noted. Her brain MRIs showed a large infarction in the right pons. On admission, she could recognize her illness but was indifferent to her hemiplegia, so she said that there was not well-off for her life. Two weeks after the onset, her neurological symptoms gradually improved. Simultaneously, her interest in her hemiparesis increased. We proposed that, in the present patient, anosognosia for hemiplegia was caused by the pontine infarction. Since pontine anosognosia for hemiplegia has been rarely reported to date, it is expected that the findings of the present patient will be useful to the better understanding of mechanisms underlying anosognosia.

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.

[Clinical pathophysiology of parkinsonian symptoms: from experiences of stereotaxic surgery]

Pathophysiological mechanisms of major symptoms of Parkinson's disease are discussed from experiences of stereotaxic surgery. Tremor completely disappears by a lesion in the ventral intermediate nucleus(Vim) which receives proprioceptive sense from the periphery. Rigidity is alleviated by a lesion in the globus pallidus(GP) and the ventral lateral nucleus(VL) equally. Since GP projects to the prefrontal motor cortex via VL, surgery to either of those structures causes the same result. Akinesia is classified into three types: secondary akinesia, primary akinesia, and akinesia due to psychomotor dysfunction. Gradual spread of neuronal degeneration within the substantia nigra pars compacta may explain the progression of akinesia. Psychological or psychiatric disorder becomes major symptom in the late stage. Posteroventral pallidotomy may change emotional state in some cases by influencing the limbic motor circuit.

In vitro susceptibility of 7.5-kb common plasmid-free Chlamydia trachomatis strains

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 in vitro susceptibility of these strains to various chemotherapeutic agents was tested by comparison with their parent strains and clinical isolates possessing the common plasmid. No difference was detected for any of the agents tested, indicating that the 7.5-kb common plasmid is unrelated to the drug resistance of C. trachomatis.

[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.

Neuronal activity in GP and Vim of parkinsonian patients and clinical changes of tremor through surgical interventions

Microrecordings were performed during pallidotomy and thalamotomy for Parkinson's disease (PD). Neuronal activity in globus pallidus (GP) was in general agreement with previous studies of human and primate models of PD. Neuronal activity, where frequency of tremor appeared to oscillate independently from peripheral input, was encountered in GPi. In contrast, neuronal activity in Vim regarding frequency of firing also correlated with tremor and was passively driven by kinesthetic stimuli with a somatotopic arrangement. Pallidal lesions based on microrecording induced relative reductions of tremor, while small Vim lesions immediately alleviated tremor. Basal ganglia pathology due to dopamine depletion could generate oscillatory neuronal activity in GPi, which may cause tremor. However, peripheral feedback to the motor cortex via Vim is also significant for tremorgenesis, because Vim may be an excitatory driving source for motor cortical neurons. Thus, a Vim lesion could reduce excitability of the motor cortical neurons and abolish tremor.

[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.

Expression and immunogenicity of hemagglutinin A from Porphyromonas gingivalis in an avirulent Salmonella enterica serovar typhimurium vaccine strain

Porphyromonas gingivalis is a major etiologic agent of periodontitis, a chronic inflammatory disease that ultimately results in the loss of the supporting tissues of the teeth. Previous work has demonstrated the usefulness of avirulent Salmonella enterica serovar Typhimurium strains as antigen delivery systems for protective antigens of pathogens that colonize or cross mucosal surfaces. In this study, we constructed and characterized a recombinant S. enterica serovar Typhimurium avirulent vaccine strain which expresses hemagglutinin A and carries no antibiotic resistance markers. HagA, a major virulence-associated surface protein, is a potentially useful immunogen that contains an antigenic epitope which, in humans, elicits an immune response that is protective against subsequent colonization by P. gingivalis. The hagA gene, including its promoter, was cloned into a balanced-lethal Salmonella vector and transferred to the vaccine strain. Heterologous expression of HagA was demonstrated in both Escherichia coli JM109 and S. enterica serovar Typhimurium vaccine strain chi4072. The HagA epitope was present in its native configuration as determined by immunochemistry and immunoelectron microscopy. Purified recombinant HagA was recognized by sera from mice immunized with the S. enterica serovar Typhimurium vaccine strain. The HagA-specific antigen of the vaccine was also found to be recognized by serum from a periodontal patient. This vaccine strain, which expresses the functional hemagglutinin protein, induces a humoral immune response against HagA and may be useful for developing a protective vaccine against periodontal diseases associated with P. gingivalis.

[A patient with marked immunodeficiency in an HTLV-I carrier: a case report]

We report a 49-year-old man who was an HTLV-I carrier with an immunodeficiency state and intracranial pyramidal tract lesion revealed by MRI. He was born in Hokkaido and was admitted to our hospital because of fluminant hepatitis. On admission, neurologic examination revealed exaggerated deep tendon reflexes including the jaw jerk; the plantar response was flexor. Laboratory examination revealed decrease in the number of lymphocytes and CD4-positive lymphocytes in the peripheral blood and CD4/CD8 ratio was consistently low, indicating the presence of cellular immunodeficiency state. Serum anti-HTLV-I antibody was markedly increased but he did not have HTLV-I associated myelopathy (HAM). He had no underlying disease which would cause immunodeficiency state such as adult T-cell leukemia (ATL) or HIV infection. We concluded that the HTLV-I carrier state induced his immunodeficiency. During the course, he developed retrobulbar neuritis. T2 weighted cranial MRI revealed high signal lesions in the bilateral corona radiata, posterior limb of the internal capsule, and the pontine base, corresponding to the location of the pyramidal tracts. His hospital course was complicated by opportunistic infections such as Pneumocystis carinii pneumonia, cytomegalovirus infections, and meningitis, and died of multiple organ failure 7 months after the admission. Cellular immunodeficiencies in ATL patients are well known. Intracranial central nervous system (CNS) lesions in HAM patients are also mentioned. Recently coincidence of ATL and HAM in the same patients has also been reported. Asymptomatic HTLV-I carriers may have a latent immunodeficiency state and/or CNS lesions. We shall have to be alert about the presence of such carriers.