Measurements of radial profile of isotope density ratio using bulk charge exchange spectroscopy.

A bulk charge exchange spectroscopy (BCXS) system using a grism (grating prism) spectrometer has been applied to measure the profile of the deuterium (D) fraction in deuterium and hydrogen (H) mixture plasma in the Large Helical Device. The observed spectrum can be fitted with four Gaussian functions successfully by reduction of free parameters for the least-squares fit. The plasma flow velocity and ion temperature profile measured by charge exchange spectroscopy using carbon impurity are used for estimation of the wavelength shift of hot components to reduce the free parameter. The ion temperature is used to estimate the apparent wavelength shift due to the energy dependent emission cross section only and is not used to set the Doppler width for H and D in the fitting. The sensitivity of the evaluated D fraction on the velocity is increased for a higher D fraction. The error of the D fraction is calculated from the error in the fitted parameter and sensitivity on the velocity of the hot component. The difference in the profile and time trace of the D fraction with D pellet and H pellet injection was observed clearly by BCXS using a grism spectrometer.

Measurements of radial profile of hydrogen and deuterium density in isotope mixture plasmas using bulk charge exchange spectroscopy.

A bulk charge exchange spectroscopy system has been applied to measure the radial profiles of the hydrogen (H) and deuterium (D) density ratio in the isotope mixture plasma in a large helical device. Charge exchange lines of Hα and Dα are fitted by 4 Gaussian of H and D cold components and H and D hot components with 5 parameters by combining the measurement of plasma toroidal rotation velocity with carbon charge exchange spectroscopy. The radial profiles of the relative density of hydrogen and deuterium ions are derived from H and D hot components measured and the beam density calculated from beam attenuation calculation. A proof-of-principle experiment is performed by the H pellet and the D pellet injections into the H-D mixture plasma.

Measurement of radial profiles of density ratio of helium to hydrogen ion using charge exchange spectroscopy with two-wavelength spectrometer.

Radial profiles of density ratio of helium to hydrogen ions are measured using the charge exchange spectroscopy technique with the two-wavelength spectrometer system in the large helical device. The two-wavelength spectrometer system consists of a dichroic mirror box, a spectrometer with two grating and two camera lenses, and one CCD detector. The dichroic mirror box is used to divide the light of one fiber from the plasma to two fibers, one for HeII (λ = 468.6 nm) and the other for H(α) (λ = 656.3 nm), that are connected to the entrance slit of the spectrometer to eliminate the interference between the HeII and the H(α) spectra on the CCD. This system provides a simultaneous measurement of helium and hydrogen ion density ratio at 8 exact same locations (8 spatial channels) with a time resolution of >40 ms in the wide range of the density ratio of 0.05-5.

Neural basis of stable perception of an ambiguous apparent motion stimulus.

Although it has been shown that an alternative dominant percept induced by an ambiguous visual scene has neural correlates in various cortical areas, it is not known how such a dominant percept is maintained until it switches to another. We measured the primary visual response to the two-frame bistable apparent motion stimulus (stroboscopic alternative motion) when observers continuously perceived one motion and compared this with the response for another motion using magnetoencephalography. We observed a response component at around 160 ms after the frame change, the amplitude of which depended on the perceived motion. In contrast, brain responses to less ambiguous and physically unambiguous motions in both the horizontal and vertical directions did not evoke such a component. The differential response evoked by the bistable apparent motion is therefore distinct from directionally-selective visual responses. The results indicate the existence of neural activity related to establish and maintain one dominant percept, the magnitude of which is related to the ambiguity of the stimulus. This is in the line with the currently proposed idea that dominant percept is established in the distributed cortical areas including the early visual areas. Further, the existence of the neural activity induced only by the ambiguous image suggests that the competitive neural activities for the two possible percepts exist even when one dominant image is continuously perceived.

[Eliminating iodine deficiency disorders in Nepal through precede-proceed].

OBJECTIVES: Assess the PRECEDE-PROCEED model's suitability for developing countries. Analyze the Iodine Deficiency Disorders (IDD) control program in Nepal according to PRECEDE-PROCEED. METHODS: Primary and secondary data analysis within the framework of PRECEDE-PROCEED's first five steps. Key informant interviews. Qualitative data from Nepal's IDD control program participants were assessed according to PRECEDE-PROCEED's third through fifth steps. RESULTS: According to the first and second steps of PRECEDE-PROCEED for social and epidemiological assessment, Nepal's IDD control program needs improvement. Limited data were available for the assessment, making it difficult to execute the first two steps with certainty. Social and epidemiological assessments can be problematic in any developing country since the necessary data are typically not available. Behavioral and environmental assessments (step three) showed that: Most people are unaware of IDD and manage iodized salt poorly. The environment within which iodized salt is managed is insufficient for maintaining proper salt iodination at the consumer level. Educational and ecological assessments (step four) pointed out several problems, including: Inadequate understanding of IDD Incorrect beliefs about refined salt Poor supply of refined salt in markets Weak regulation of non-iodized salt importation and sales Finally, administrative and policy assessments (step five) emphasized the need for an active role of the Salt Trading Corporation in Nepal, with a significant manpower and budget, in improving the IDD program. Data for completing PRECEDE-PROCEED steps three through five were readily available. In addition to providing a framework within which to assess Nepal's IDD control program, the model helped highlight specific action goals for behavioral and environmental objectives (consume more iodized salt, improve quality of salt warehouses and increase iodized salt's market availability). DISCUSSION: Though it was difficult to obtain data for social and epidemiological assessments, the PRECEDE-PROCEED model proved useful in analyzing IDD control in Nepal. The model can comprehensively analyze ongoing interventions and assess the status of various nation-wide health programs, highlighting areas of modification needed to help programs achieve their goals.

A flash-lag effect in random motion.

The flash-lag effect refers to the phenomenon in which a flash adjacent to a continuously moving object is perceived to lag behind it. To test three previously proposed hypotheses (motion extrapolation, positional averaging, and differential latency), a new stimulus configuration, to which the three hypotheses give different predictions, was introduced. Instead of continuous motion, a randomly jumping bar was used as the moving stimulus, relative to which the position of the flash was judged. The results were visualized as a spatiotemporal correlogram, in which the response to a flash was plotted at the space-time relative to the position and onset of the jumping bar. The actual human performance was not consistent with any of the original hypotheses. However, all the results were explained well if the differential latency was assumed to fluctuate considerably, its probability density function being approximated by Gaussian. Also, the model fit well with previously published data on the flash-lag effect.

Penetrating colon ulcer of polyarteritis nodosa: report of a case.

A 54-year-old Japanese female with polyarteritis nodosa was admitted to the hospital. She developed lower abdominal pain accompanied by melena. A penetrating ulcer and extensive hemorrhaging were endoscopically observed in the sigmoid colon, and a sigmoidectomy was performed. The pathologic findings were a granuloma formation with lymphocytic infiltration and luminal occlusion of branches of the mesenteric arteries. Although the gastrointestinal tract is frequently involved in polyarteritis nodosa, the colon is rarely affected. To our knowledge, this is the first report of polyarteritis nodosa causing a penetrating ulcer of the colon.

Progesterone inhibits apolipoprotein-mediated cellular lipid release: a putative mechanism for the decrease of high-density lipoprotein.

In order to investigate the mechanism for female gonadal hormones to regulate the plasma high-density lipoprotein (HDL) level, the effect of 17 beta-estradiol and progestogens was examined in vitro on the assembly of HDL by free apolipoprotein A-I (apoA-I) with cellular cholesterol and phospholipid. ApoA-I generated HDL particles by removing cholesterol and phospholipid from human fibroblasts, MRC-5. While 17 beta-estradiol did not influence this reaction, progesterone suppressed the removal by apoA-I of both cholesterol and phospholipid, with the extent of the inhibition more for cholesterol than phospholipid. Three other synthetic progestogens showed the similar inhibitory effect on the cellular cholesterol release. Cellular cholesterol de novo-synthesized from mevalonolactone entered more into the acyl-esterified cholesterol compartment and less to the unesterified compartment in the presence of progesterone. On the other hand, progesterone did not influence the overall mass ratio of free and esterified cholesterol in the cell. Cell-surface cholesterol was also uninfluenced by progesterone when probed by extracellular cholesterol oxidase reaction or by diffusion-mediated cellular cholesterol release to cyclodextrin. Neither caveolin-1 nor ABCA1 expression was influenced by progesterone. Progesterone thus seems primarily to alter the specific intracellular cholesterol compartment that is related to the apoA-I-mediated HDL assembly. This mechanism might contribute to the decrease of plasma HDL by administration of progestogen in women under hormone replacement therapy.

[A case of drug-resistant pulmonary tuberculosis treated successfully following disappearance of rifampicin resistance after 17 years' chemotherapy].

A female who first acquired pulmonary tuberculosis in 1962 when she was 25 years old, admitted to the National Hiroshima Hospital in 1982. Her sputum has been smear positive for acid-fast bacilli for 3 years before admission in spite of continuous antituberculous chemotherapy, and were resistant to isoniazid (INH) and rifampicin (RFP). She was treated with a regimen containing ethambutol (EB), prothionamide (TH) and enviomycin (EVM) but continued to be culture positive. Though she was treated with various regimens which include one to three sensitive drugs, her sputum continued to be positive for M. tuberculosis in the following 14 years. During the course, resistance to EB, TH, cycloserine (CS) and streptomycin (SM) emerged. Resistance to RFP temporarily retracted in 1988, but her sputum was bacilli negative only for 2 months after the addition of RFP to previous regimen, and followed by resurgence of RFP resistance. In 1992, data of drug sensitivity tests showed sensitivity to TH, CS and RFP in turn, which were not used for 3 to 5 years. In 1993, she was treated with RFP, TH and EVM successfully and continued to be bacteriologically negative for 7 years so far. Drug resistance to M. tuberculosis is induced by inappropriate chemotherapy as seen in this case. Regimens with less than three drugs without RFP and INH was not only insufficient to get cure but, what was worse, also induced additional resistance to used drugs. The reason of successful chemotherapy in this case was spontaneous disappearance of drug resistance to RFP and TH. This case suggests that the disappearance of drug resistance is possible, when drugs are not used for more than a few years, hence the successful treatment could be expected. However it must be emphasized that the drug resistance is produced by incorrect treatment as seen in this case, and its prevention is of the prime importance.

Mixed duct-acinar-islet cell tumor of the pancreas: report of a case.

A 72-year-old Japanese woman presented at our hospital complaining of altered consciousness on arising every morning. The laboratory findings showed hypoglycemia and hyperinsulinemia. Abdominal ultrasonography revealed a tumor in the body of the pancreas. With a diagnosis of insulinoma, a surgical excision of the tumor was performed. A light microscopic examination and an immunohistochemical study revealed the tumor to consist of duct, acinar, and islet cell components. Mixed tumors of the pancreas are rare, and their clinical features and pathogenesis remain unclear. A further accumulation of clinical cases as well as a large number of histopathological studies on these rare mixed tumors is needed.

Visual jitter: evidence for visual-motion-based compensation of retinal slip due to small eye movements.

When dynamic random noise is replaced by static noise after a period of adaptation, adjacent unadapted regions filled with static noise appear to 'jitter' coherently in random directions for several seconds, actually mirroring the observer's own eye movements of fixation [Murakami, I. & Cavanagh, P. (1998). Nature, 395, 798-801]. The present study aims at psychophysically locating two distinct stages underlying this visual jitter phenomenon: a monocular, adaptable stage that measures local retinal motion and a compensation stage that estimates a baseline motion minimum and subtracts it from motion vectors nearby. The first three experiments revealed that visual jitter has storage, directional selectivity, and spatial frequency selectivity, like the motion after-effect does. These results suggest some overlap in the adaptation mechanisms for the two effects, possibly at or below the level of primary visual cortex. The next two experiments revealed the transfer of the effect across the vertical meridian as well as the existence of a preferred stimulus size that is a linear increasing function of eccentricity, mimicking the RF size of the monkey MT neurons. These results suggest that some extrastriate motion area along the parietal pathway including MT mediates motion-based compensation of retinal slip.

A case of massive subchorionic thrombohematoma diagnosed by ultrasonography and magnetic resonance imaging.

Massive subchorionic thrombohematoma is uncommon but associated with a poor perinatal prognosis. Placental enlargement was detected in a 25-year-old Japanese primipara woman with fetal growth retardation and oligohydramnios at 23 weeks' gestation. Ultrasonography (USG) showed an abnormal sonolucency within the placenta at 28 weeks' gestation, but could not give an unequivocal differentiation from placental abnormalities such as hematomas, cysts and other tumors. Magnetic resonance imaging (MRI) pointed to a large hematoma in the subchorionic region. Simultaneously, the amniotic fluid was brownish colored. From these findings, it was possible to have prenatal diagnosis of massive subchorionic thrombohematoma. At 32 weeks' gestation, the fetus died in utero and was stillborn 3 days later. Pathological findings for the placenta revealed a large hematoma diffused between the villous chorion and the chorionic plate, with wide necrosis of placental tissue, likely due to formation of multiple thrombi. The clinical and pathological findings were compatible with massive subchorionic thrombohematoma. MRI might be useful for the detection of massive subchorionic thrombohematoma and help its clinical management in combination with USG and pulse Doppler imaging.

[Treatment outcomes of multidrug-resistant tuberculosis--comparison between success and failure cases].

The thirty-two times of treatment in 27 patients with multidrug-resistant tuberculosis (MDR-TB) were analyzed retrospectively. In twenty-eight times of treatments cases had previous histories of antituberculosis chemotherapy. Drug sensitivity tests were performed by Microtiter method for isoniazid (INH), rifampicin (RFP), ethambutol, streptomycin, kanamycin, enviomycin, ethionamide, para-aminosalicylic acid and cycloserine. A drug is defined as 'active drug' when the drug was proved to be sensitive by the drug sensitivity tests or never used in the past or used for not more than 2 months in case of pyrazinamide (PZA) and less than one month for fluoroquinolones. Outcomes of treatments were grouped as follows; A: bacteriologically negative for more than 24 months, B: bacteriologically negative for more than 6 months but less than 24 months, C: bacteriologically relapsed after negative conversion, D: continuously bacilli positive for M. tuberculosis. Mean age of patients in each group were; 61.0 yrs for group A (n = 10), 61.0 yrs for group B (n = 7), 52.5 yrs for group C (n = 4), 57.9 yrs for group D (n = 11). All patients had cavitary disease and positive sputum smears for acid-fast bacilli. Mean numbers of 'active drugs' used per treatment in each group, were 3.6, 3.3, 2.5 and 1.8 respectively, while the mean number of resistant drug including INH and RFP were 2.8, 3.3, 2.5 and 3.7. The number of drugs, which was unable to use due to toxicity, were 0.20, 0.14, 0.50, and 0.73 per treatment respectively. All of 9 patients treated with four 'active drugs' were in group A or B and succeeded to achieve negative conversion. The duration of chemotherapy in group A was 13 to 44 months. Treatment had failed in 4 out of 11 patients treated with 3 'active drugs' and 11 out of 12 patients treated with less than 2 'active drugs'. Fluoroquinolones (ofloxacin, levofloxacin or sparfloxacin) were used in 7 out of 10 patients in group A and in 6 out of 9 patients treated with four-drug regimens while they were used only in 3 out of 11 patients in group D. Regimens with at least 4 sensitive drugs are mandatory for the successful treatment of MDR-TB and fluoroquinolones are needed in the majority of cases to ensure the four-drug regimen, because of frequent drug resistance or toxicity to other antituberculosis drugs.

Simple testicular cyst in infants: a case report and review of the literature.

We report a 5-month-old boy with testicular cyst. He presented with a right inguinal hernia and a scrotal mass. Ultrasonography showed a cystic mass in the right testicular parenchyma, suggesting a testicular cyst. He underwent right herniotomy and unroofing of the cyst. Simple testicular cyst is extremely rare with only 48 cases reported in the literature. Of these cases, 8 patients were less than two years old. The diagnosis of simple testicular cyst can be made preoperatively with ultrasonography. Testis-preserving excision or unroofing the cyst is the treatment of choice.

The flash-lag effect as a spatiotemporal correlation structure.

The flash-lag effect refers to the phenomenon in which a flash adjacent to a continuously moving object is perceived to lag behind it. Phenomenally, the flash appears to be spatially shifted relative to the moving stimulus, and the amount of lag has often been quantified as the flash's nulling position, which is the physical spatial offset needed to establish perceptual alignment. The present study offers a better way to summarize flash-lag data. Instead of plotting data in terms of space, the psychometric function of the observer's relative-position judgment is drawn on spatiotemporal plot. The psychological process underlying illusory lag is formulated as spatiotemporal bias and uncertainty and their estimate as a spatiotemporal convolution kernel that best explains the spatiotemporal psychometric function. Two empirical procedures of kernel estimation are described. One procedure is to fit the free parameters of the kernel to experimental data for continuous motion trajectory. The second is to give an analytical solution to the kernel using experimental data for random motion trajectory. The two procedures yield similar kernels, with negligible spatial bias and uncertainty and substantial temporal bias and uncertainty. In addition, it is demonstrated that an experimental manipulation of temporal predictability of the flash can change the temporal bias in the estimated kernel. The results of this novel analysis reveal that the flash-lag effect is viewed as a spatiotemporal correlation structure, which is largely characterized by the tendency to compare the position of the flash in the past with the position of the moving item in the present.

Temporal facilitation for moving stimuli is independent of changes in direction.

A flash that is presented aligned with a moving stimulus appears to lag behind the position of the moving stimulus. This flash-lag phenomenon reflects a processing advantage for moving stimuli (Metzger, W. (1932) Psychologische Forschung 16, 176-200; MacKay, D. M. (1958) Nature 181, 507-508; Nijhawan, R. (1994) Nature 370, 256-257; Purushothaman, G., Patel, S.S., Bedell, H.E., & Ogmen, H. (1998) Nature 396, 424; Whitney, D. & Murakami, I. (1998) Nature Neuroscience 1, 656-657). The present study measures the sensitivity of the illusion to unpredictable changes in the direction of motion. A moving stimulus translated upwards and then made a 90 degrees turn leftward or rightward. The flash-lag illusion was measured and it was found that, although the change in direction was unpredictable, the flash was still perceived to lag behind the moving stimulus at all points along the trajectory, a finding that is at odds with the extrapolation hypothesis (Nijhawan, R. (1994) Nature 370, 256-257). The results suggest that there is a shorter latency of the neural response to motion even during unpredictable changes in direction. The latency facilitation therefore appears to be omnidirectional rather than specific to a predictable path of motion (Grzywacz, N. M. & Amthor, F. R. (1993) Journal of Neurophysiology 69, 2188-2199).

Neural selectivity for hue and saturation of colour in the primary visual cortex of the monkey.

In the inferior temporal (IT) cortex of monkeys, which has been shown to play a critical role in colour discrimination, there are neurons sensitive to a narrow range of hues and saturation. By contrast, neurons in the retina and the parvocellular layer of the lateral geniculate nucleus (pLGN) encode colours in a way that does not provide explicit representation of hue or saturation, and the process by which hue- and saturation-selectivity is elaborated remains unknown. We therefore tested the colour-selectivity of neurons in the primary visual cortex (V1) and compared it with those of pLGN and IT neurons. Quantitative analysis was performed using a standard set of colours, systematically distributed within the CIE (Commission Internationale de l'Eclairage)-xy chromaticity diagram. Selectivity for hue and saturation was characterized by analysing response contours reflecting the overall distribution of responses across the chromaticity diagram. We found that the response contours of almost all pLGN neurons were linear and broadly tuned for hue. Many V1 neurons behaved similarly; nonetheless, a considerable number of V1 neurons had clearly curved response contours and were selective for a narrow range of hues or saturation. The relative frequencies of neurons exhibiting various selectivities for hue and saturation were remarkably similar in the V1 and IT cortex, but were clearly different in the pLGN. Thus, V1 apparently plays a very important role in the conversion of colour signals necessary for generating the elaborate colour selectivity observed in the IT cortex.

Illusory spatial offset of a flash relative to a moving stimulus is caused by differential latencies for moving and flashed stimuli.

A flash that is presented adjacent to a continuously moving bar is perceived to lag behind the bar. One explanation for this phenomenon is that there is a difference in the persistence of the flash and the bar. Another explanation is that the visual system compensates for the neural delays of processing visual motion information, such as the moving bar, by spatially extrapolating the bar's perceived location forward in space along its expected trajectory. Two experiments demonstrate that neither of these models is tenable. The first experiment masked the flash one video frame after its presentation. The flash was still perceived to lag behind the bar, suggesting that a difference in the persistence of the flash and bar, does not cause the apparent offset. The second experiment employed unpredictable changes in the velocity of the bar including an abrupt reversal, disappearance, acceleration, and deceleration. If the extrapolation model held, the bar would continue to be extrapolated in accordance with its initial velocity until the moment of an abrupt velocity change. The results were inconsistent with this prediction, suggesting that there is little or no spatial compensation for the neural delays of processing moving objects. The results support a new model of temporal facilitation for moving objects whereby the apparent flash lag is due to a latency advantage for moving over flashed stimuli.

Sex chromosomal analysis of spermatozoa from infertile men using fluorescence in situ hybridization.

PURPOSE: To confirm an association between male infertility and chromosome aberrations of spermatozoa, we demonstrated the frequency of numerical abnormalities of spermatozoa from infertile men with abnormal semen parameters compared with fertile controls. METHOD: Sperm cells from 10 infertile patients were investigated for disomy rates of sex chromosomes and chromosome 18 and diploidy by fluorescence in situ hybridization (FISH). All patients showed oligoasthenozoospermia with sperm counts 3-20 x 10(6)/ml and motile rates 0-40%. RESULTS: Regarding XY disomy, a significantly higher frequency was found in 8 of 10 patients as compared to normal fertile men. The disomy rates of chromosome 18, XX, YY, and diploidy rate were not increased. CONCLUSIONS: There is an association between male infertility and embryo with aneuploidy of sex chromosomes. Counseling about possible genetic risks should be provided to the infertile couples planning assisted reproduction treatment.