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Biomedical subjects

T Inui

Publications and source records attributed to T Inui.

At least 19 recordsLinked to original sources

Biosensor-based control of nitrification inhibitor in municipal wastewater treatment plants.

The effect of potassium cyanide (KCN) on nitrification processes in municipal wastewater treatment plants was studied by batch nitrification tests, which indicated that nitrification processes tend to be inhibited at a lower KCN concentration than the present discharge standard to sewerage. The experiment of the biosensor using nitrifying bacteria was also conducted for continuous monitoring of nitrification inhibitor in influent wastewater, and demonstrated that the biosensor can detect KCN at as low as EC10 of the abovementioned batch nitrification test. Moreover, to determine the effectiveness of application of the biosensor to avoid the impact of KCN due to an accidental spillage in a sewerage system, KCN was intentionally injected into the experimental models of activated sludge process equipped both with and without the biosensor. The model with the biosensor that could detect KCN could divert the wastewater including KCN to a refuge tank, which resulted in the avoidance of upset of the activated sludge process. On the other hand, the model without the biosensor was upset in the nitrification process due to KCN. Such differences demonstrate the effectiveness of the biosensor applied to countermeasures of an accidental spillage of toxic chemicals to avoid upset of nitrification in municipal wastewater treatment plants.

Bioreactors↗

A newly designed disposable introducer sheath for a ventricular fiberscope.

We have developed a disposable plastic introducer sheath for use with a flexible endoscope during intraventricular procedures. The sheath is composed of a thin polypropylene tube passing through the center of a plastic stopper. The tube serves as a sheath through which the fiberscope is introduced into the ventricle. The stopper seats in the burr hole and prevents downward and lateral movement of the tube. The sheath can be placed safely in the ventricle with a drainage catheter used as an introducing guide. We used this sheath system in 10 patients and found it very useful. Manipulation of the fiberscope was not hindered, copious irrigation was allowed, and the sheath remained stable on the skull. This new introducer sheath may contribute to the increased use of a flexible endoscope in neuroendoscopic procedures.

Cerebral Ventricles↗

Orexin reverses cholecystokinin-induced reduction in feeding.

AIM: This study was designed to investigate the effect of orexin on anorexia induced by cholecystokinin (CCK),a peripheral satiety signal. METHODS: We administered orexin A (0.01-1 nmol/mouse) and CCK-8 (3 nmol/mouse) to mice. Food intake was measured at different time-points: 20 min, 1, 2 and 4 h post-intracerebroventricular (i.c.v.) or intraperitoneal (i.p.) administrations. RESULTS: Intracerebroventricular-administered orexin significantly increased food intake in a dose-dependent manner. The inhibitory effect of i.p.-administered CCK-8 on food intake was significantly negated by the simultaneous i.c.v. injection of orexin in a dose-dependent manner. CONCLUSIONS: Orexin reversed the CCK-induced loss of appetite. Our results indicate that orexin might be a promising target for pharmacological intervention in the treatment of anorexia and cachexia induced by various diseases.

Analysis of Variance↗

Application of toxicity monitor using nitrifying bacteria biosensor to sewerage systems.

Toxic substances may be included in wastewater influent and can damage biological processing of wastewater treatment, therefore continuous toxic-monitoring of wastewater influent is needed. This paper describes the potential toxic-monitoring applications of the toxicity monitor using a nitrifying bacteria biosensor to sewerage systems. The results of sensitivity tests show that aspects of wastewater do not affect the sensor sensitivity and confirm that the sensor can be applied to wastewater monitoring as it is. The monitor with a prototype of filtration system installed in a wastewater treatment plant is able to operate continuously for one month at least after the modification of filtration system and the optimization of operation conditions.

Biosensing Techniques↗

Brefeldin A inhibits osteoclastic bone resorption through induction of apoptosis.

Brefeldin A (BFA), a fungal metabolite with a macrocyclic lactone structure, has been developed for the treatment of cancer, and its major biological activity is the inhibition of intracellular protein transport from the endoplasmic reticulum to the cis-Golgi apparatus. In this study, we investigated the effect of BFA on osteoclastic pit formation in vitro. BFA reduced pit formation in a concentration-dependent manner, and the IC50 values on the pit number and the pit volume were 11.3 +/- 2.2 and 13.3 +/- 2.0 nM, respectively. In parallel with the inhibitory effect on pit formation, BFA also reduced the cell viability of osteoclasts-enriched bone cells with an IC50 value of 13.9 +/- 2.2 nM. These results suggest that the inhibition of bone resorption by BFA is caused by the induction of osteoclast cell death. BFA at a concentration of 100 nM induced DNA fragmentation in purified osteoclasts, assessed by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and DNA ladder formation, demonstrating that BFA induces cell death of osteoclasts in an apoptotic manner. In addition, the accumulation of p53 proteins to the nuclei was observed in the osteoclasts treated with 100 nM BFA. These results, taken together, suggest that BFA inhibits osteoclastic bone resorption by inducing apoptosis in osteoclasts through a p53-dependent mechanism.

Animals↗

Midkine binds to 37-kDa laminin binding protein precursor, leading to nuclear transport of the complex.

Midkine (MK) is a heparin binding multifunctional protein that promotes cell survival and cell migration. MK was found to bind to 37-kDa laminin binding protein precursor (LBP), a precursor of 67-kDa laminin receptor, with K(d) of 1.1 nM between MK and LBP-glutathione-S-transferase fusion protein. The binding was inhibited by laminin, anti-LBP, amyloid beta-peptide, and heparin; the latter two are known to bind to MK. In CMT-93 mouse rectal carcinoma cells, LBP was mostly located in the cytoplasm as revealed by immunostaining with anti-LBP antibody. That a portion of LBP or 67-kDa laminin receptor was located at the surface of these cells was verified by inhibition of cell attachment to laminin-coated dishes by anti-LBP antibody. When MK was added to culture medium of these cells, a part of LBP migrated to the nucleus. The movement occurred concomitantly with nuclear transport of biotin-labeled MK. These findings suggested that the binding of MK to LBP caused nuclear translocation of the molecular complex.

Active Transport, Cell Nucleus↗

The patient-physician relationship. Teaching the human dimensions of care in clinical settings.

Despite repeated calls to emphasize the humanistic dimensions of care during medical education, these are few known techniques for effective teaching of humanism. We describe the barriers that inhibit humanistic teaching and suggest pragmatic teaching methods to overcome such barriers and teach humanistic care in clinical settings. We began by asking participants at a conference on patient-physician communications sponsored by the American Academy on Physician and Patient in June 1998, "What can we do in the patient's presence to improve and teach the human dimensions of care? Please provide one or more examples of approaches you found to be effective." We augmented this information with suggestions from a number of colleagues in other settings. In a series of iterations, we analyzed all their suggestions to identify key teaching methods. We found that barriers to teaching humanism largely consist of elements of the informal and hidden curricula in medical schools. We then defined methods to help teachers overcome these barriers. Specific methods fall into the 3 categories of taking advantage of seminal events, role modeling, and using active learning skills. We believe that formal courses and other well-motivated endeavors that take place away from patients fail to foster humanistic care. In contrast, we present pragmatic teaching methods that can be used in the fast-paced setting of the clinical environment.

Education, Medical↗

Visual language and handwriting movement: functional magnetic resonance imaging at 3 tesla during generation of ideographic characters.

A functional magnetic resonance imaging experiment at 3 tesla was performed to investigate the collaborative mechanism between visuospatial processing and motor execution in performing visual language generation tasks. Japanese Kanji, ideographic characters, were utilized to design tasks. The bilateral border portions between the inferior parietal lobule and the occipital lobe were involved during a Kanji puzzle task, which required subjects to combine several parts into a Kanji. The higher motor areas, such as the premotor areas and the pre-supplementary motor areas, were also activated bilaterally during the puzzle task. The parieto-occipital activation may be related to analysis of configuration or segmentation/integration of Kanji figures. Activation in the higher motor areas may be induced by cognitive components related to motor function to perform the visuospatial language task, such as intense reference for displayed characters and finding a proper character for puzzle solution. A collaborative mechanism in these areas may explain the effectiveness of tactile reading in letter recognition by patients with pure alexia or kinesthetic facilitation by Kanji users when recalling difficult Kanji.

Adult↗

Neural substrates involved in imitating finger configurations: an fMRI study.

Imitation plays a very important role in human cognition. Because previous neuroimaging studies on human imitation used rather simple actions as target stimuli, some aspects of imitation such as perceiving target actions or manipulating one's own mental image could not be studied. We used complicated non-symbolic (S-) and symbolic (S+) finger configurations as target stimuli in order to study the neural substrates involved in the perception of target actions and mental image manipulation during imitation. Bilateral supramarginal gyrus activation was detected when the S- condition was compared with the S+ condition. Our result suggests the involvement of the supramarginal gyrus especially for the imitation of novel actions.

Adult↗

Attractin/mahogany/zitter plays a critical role in myelination of the central nervous system.

The rat zitter (zi) mutation induces hypomyelination and vacuolation in the central nervous system (CNS), which result in early-onset tremor and progressive flaccid paresis. By positional cloning, we found a marked decrease in Attractin (Atrn) mRNA in the brain of the zi/zi rat and identified zi as an 8-bp deletion at a splice donor site of Atrn. Atrn has been known to play multiple roles in regulating physiological processes that are involved in monocyte-T cell interaction, agouti-related hair pigmentation, and control of energy homeostasis. Rat Atrn gene encoded two isoforms, a secreted and a membrane form, as a result of alternative splicing. The zi mutation at the Atrn locus darkened coat color when introduced into agouti rats, as also described in mahogany (mg) mice, carrying the homozygous mutation at the Atrn locus. Transgenic rescue experiments showed that the membrane-type Atrn complemented both neurological alteration and abnormal pigmentation in zi/zi rats, but that the secreted-type Atrn complemented neither mutant phenotype. Furthermore, we discovered that mg mice exhibited hypomyelination and vacuolation in the CNS associated with body tremor. We conclude from these results that the membrane Atrn has a critical role in normal myelination in the CNS and would provide insights into the physiology of myelination as well as the etiology of myelin diseases.

Agouti Signaling Protein↗

Quantification of the expression levels of lysosomal cysteine proteinases in purified human osteoclastic cells by competitive RT-PCR.

Cathepsin K is a lysosomal cysteine proteinase (LCP) predominantly expressed in osteoclasts. This study was conducted to evaluate the importance of human cathepsin K for osteoclastic bone resorption relative to that of other LCPs. To accomplish this, we quantitatively determined the expression levels of major LCPs (cathepsins B, K, L, and S) in human osteoclastic cells by using competitive RT-PCR. Giant cell tumor of bone (GCT) was used as a source of human osteoclastic cells, since the tissue was shown to contain a large number of cells satisfying the criteria for typical osteoclasts. The involvement of LCPs in the bone-resorption process by the GCT cells was confirmed by showing that trans-epoxysucciny-L-leucylamido-(4-guanidino) butane (E-64), a nonselective cysteine proteinase inhibitor, exerted an inhibitory effect on the pit formation. We isolated osteoclast-like cells (OLCs) positive for tartrate-resistant acid phosphatase (TRAP) and cathepsin K from the GCT tissue to a degree of almost 95% purity. In these cells, the expression of cathepsin K was shown to be approximately 20-, 130-, and 410-fold stronger than that of cathepsins B, L, and S, respectively. A similar result was obtained when human bone marrow cells in culture were used as another source of OLCs. Further, we found that cathepsin K was expressed in OLCs far more strongly than in several human nonosteoclastic cells including osteoblastic cell lines. The abundant and selective expression of cathepsin K in OLCs relative to that of other LCPs suggests that cathepsin K is mainly responsible for osteoclastic degradation of human bone matrix.

Acid Phosphatase↗

Endoscopically demonstrable esophageal changes after Helicobacter pylori eradication in patients with gastric disease.

BACKGROUND AND AIMS: An increased prevalence of reflux esophagitis has been reported following Helicobacter pylori (H. pylori) eradication in patients with duodenal ulcers in Western countries. However, it has remained unknown whether this might also appertain to individuals with other diseases. We therefore carried out this study to determine the effect of eradicating H. pylori infection in a series of Japanese patients. METHODS: Of a total of 203 H. pylori-positive patients successfully cured of infection, 82 cases (58 males, 24 females) with gastric disease, but not duodenal ulcers, were included in the present study; median age 56 years (range 18-80) and median follow up of 24 months (range 6-65). The patients were investigated clinically and endoscopically at regular intervals. RESULTS: Mild reflux esophagitis developed after eradication in three of 55 (5.5%) patients formerly without this condition, while it improved after eradication in five of 27 (18.5%) patients, with the disease endoscopically diagnosed prior to eradication. The estimated incidence of esophagitis within 3 years was 4.8% after cure of infection. Short segment Barrett's esophagus developed after eradication in six of 58 (10.3%) patients who did not have it prior to the therapy, while the condition did not improve in 24 patients affected before eradication. CONCLUSIONS: Endoscopic esophageal changes after H. pylori eradication in the present series of Japanese patients were relatively infrequent and mild. This therapeutic approach thus appears to be safe and unproblematic.

Adolescent↗

Doctor discontent. A comparison of physician satisfaction in different delivery system settings, 1986 and 1997.

OBJECTIVE: To examine the differences in physician satisfaction associated with open- versus closed-model practice settings and to evaluate changes in physician satisfaction between 1986 and 1997. Open-model practices refer to those in which physicians accept patients from multiple health plans and insurers (i.e., do not have an exclusive arrangement with any single health plan). Closed-model practices refer to those wherein physicians have an exclusive relationship with a single health plan (i.e., staff- or group-model HMO). DESIGN: Two cross-sectional surveys of physicians; one conducted in 1986 (Medical Outcomes Study) and one conducted in 1997 (Study of Primary Care Performance in Massachusetts). SETTING: Primary care practices in Massachusetts. PARTICIPANTS: General internists and family practitioners in Massachusetts. MEASUREMENTS: Seven measures of physician satisfaction, including satisfaction with quality of care, the potential to achieve professional goals, time spent with individual patients, total earnings from practice, degree of personal autonomy, leisure time, and incentives for high quality. RESULTS: Physicians in open- versus closed-model practices differed significantly in several aspects of their professional satisfaction. In 1997, open-model physicians were less satisfied than closed-model physicians with their total earnings, leisure time, and incentives for high quality. Open-model physicians reported significantly more difficulty with authorization procedures and reported more denials for care. Overall, physicians in 1997 were less satisfied in every aspect of their professional life than 1986 physicians. Differences were significant in three areas: time spent with individual patients, autonomy, and leisure time (P < or =.05). Among open-model physicians, satisfaction with autonomy and time with individual patients were significantly lower in 1997 than 1986 (P < or =.01). Among closed-model physicians, satisfaction with total earnings and with potential to achieve professional goals were significantly lower in 1997 than in 1986 (P < or =.01). CONCLUSIONS: This study finds that the state of physician satisfaction in Massachusetts is extremely low, with the majority of physicians dissatisfied with the amount of time they have with individual patients, their leisure time, and their incentives for high quality. Satisfaction with most areas of practice declined significantly between 1986 and 1997. Open-model physicians were less satisfied than closed-model physicians in most aspects of practices.

Adult↗

Molecular and phenotypic analysis of Attractin mutant mice.

Mutations of the mouse Attractin (Atrn; formerly mahogany) gene were originally recognized because they suppress Agouti pigment type switching. More recently, effects independent of Agouti have been recognized: mice homozygous for the Atrn(mg-3J) allele are resistant to diet-induced obesity and also develop abnormal myelination and vacuolation in the central nervous system. To better understand the pathophysiology and relationship of these pleiotropic effects, we further characterized the molecular abnormalities responsible for two additional Atrn alleles, Atrn(mg) and Atrn(mg-L), and examined in parallel the phenotypes of homozygous and compound heterozygous animals. We find that the three alleles have similar effects on pigmentation and neurodegeneration, with a relative severity of Atrn(mg-3J) > Atrn(mg) > Atrn(mg-L), which also corresponds to the effects of the three alleles on levels of normal Atrn mRNA. Animals homozygous for Atrn(mg-3J) or Atrn(mg), but not Atrn(mg-L), show reduced body weight, reduced adiposity, and increased locomotor activity, all in the presence of normal food intake. These results confirm that the mechanism responsible for the neuropathological alteration is a loss--rather than gain--of function, indicate that abnormal body weight in Atrn mutant mice is caused by a central process leading to increased energy expenditure, and demonstrate that pigmentation is more sensitive to levels of Atrn mRNA than are nonpigmentary phenotypes.

Age Factors↗

[Effects of figural complexity and target-distracter similarity on decay rate in short-term visual memory].

We examined the effects of figural complexity and target-distracter similarity on decay rate in short-term visual memory (STVM) for closed contours. The subject's task was to compare two stimuli presented at different points in time. Experiment 1 showed that even a simple pattern with 6 convex parts cannot be handled in STVM for several seconds without loss. Experiments 1 and 2 indicated that decay rate tends to be higher for patterns with higher complexity and for patterns with higher target-distracter similarity regardless of pattern complexity. These results are interpreted that the value of each convex part represented in STVM is an independent Gaussian random variable and that memory noise increases with retention intervals for each convex part separately. Furthermore, they suggest that memory for local features in STVM decays faster. Yet visual rehearsal appears to operate effectively on memorizing even complex patterns. It is concluded that visually presented patterns can be retained in STVM with relatively high fidelity for prolonged periods of time, although some loss of precision occurs inevitably.

Form Perception↗