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Biomedical subjects

K Mori

Publications and source records attributed to K Mori.

At least 73 records · Page 4Linked to original sources
PubMed2002

Plasma levels of natriuretic peptide and echocardiographic parameters in patients with Duchenne's progressive muscular dystrophy.

We investigated the relationship between plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels and systolic and diastolic cardiac function, determined by echocardiography, in 63 patients with Duchenne's progressive muscular dystrophy (DMD) (age range 8-21 years). The relationship between shortening fraction of the left ventricle and ANP and BNP levels was curvilinear rather than linear: When the shortening fraction was >15%, increases in ANP and BNP levels were minimal. However, if the shortening fraction was <15%, both natriuretic peptide levels increased dramatically. Stepwise regression analysis revealed that only the deceleration time of the early diastolic filling wave predicted plasma BNP concentration among various diastolic echocardiographic parameters determined by mitral flow. Three patients died of cardiac dysfunction during a 2-year follow-up period. These patients had a severely decreased deceleration time (<65% of normal) in association with increases in both natriuretic peptide levels. In conclusion, plasma ANP and BNP levels are not sensitive markers for the early detection of cardiac systolic dysfunction in patients with DMD. However, in patients with systolic dysfunction, an increase in the concentrations of these peptides, associated with a decrease in the deceleration time of early diastolic filling, suggests poor prognosis.

Adolescent↗
PubMed2002

Semiquantitative dynamic computed tomography to predict response to anti-platelet therapy in acute cerebral infarction.

We investigated whether dynamic computed tomography (CT) in patients with acute cerebral infarction could identify patients likely to respond to anti-platelet therapy. Seventy patients underwent semiquantitative dynamic CT within 6 h as well as cerebral angiography. All then received anti-platelet therapy with a thromboxane A2 synthetase inhibitor. Peak value (pv) and time-to-peak (tp) (time-density curves) for the Sylvian fissure were extracted from dynamic CT data and standardizing interpatient data, two indices, PV/TP index and TP index, were prepared following a standard semiquantitative manner. Both PV/TP index and TP index were effective in discriminating between 48 responders (modified Rankin scale (mRS): 0 to 2) and 22 non-responders (mRS: 3 to 5, or death: 6; both P<0.0001). High PV/TP index (>or=0.8) was a strong indicator of favorable response. Most of these patients maintained regional cerebral blood flow (rCBF) via anterograde flow or collaterals, with a TP index 1.1) and non-compensated rCBF. Intermediate PV/TP values could not predict outcome. Dynamic CT prior to therapy can identify patients with acute cerebral infarction who are treatable with anti-platelet therapy alone.

Acute Disease↗
PubMed2002

A time-course study on the resistance of Penaeus japonicus induced by artificial infection with white spot syndrome virus.

The onset and duration of resistance in experimental survivors of Penaeus japonicus produced by an intramuscular injection with white spot syndrome virus (WSSV) were surveyed by re-challenge tests with the virus conducted at weeks 1-4 and months 1-3 post initial exposure (PIE) to the virus. Virus neutralising activity in the survivors' plasma was also examined. Plasma-treated WSSV was separated from the plasma by centrifugation and then injected into naïve shrimp, in parallel with each re-challenge test. Re-challenge tests of the survivors conducted at weeks 1-4 PIE revealed that the resistance commenced at week 3 (relative percent survival, RPS: 39%) and almost fully developed at week 4 (RPS: 58%), because statistically significant differences in survival rates were observed between the test (previously virus exposed) and control groups at weeks 3 and 4. Re-challenge at months 1-3 PIE resulted in RPS values of 67, 54 and 6%, respectively, indicating the resistance persisted until month 2. RPS values in neutralisation tests performed at weeks 1-4 and months 1-3 PIE were -5, 14, 36, 50, 100, 38 and 6%, respectively, which coincided with the RPS values in each re-challenge test conducted in parallel. The present results demonstrated that resistance of P. japonicus against the viral pathogen developed 3 or 4 weeks after an exposure to the virus, and it persisted for another month at 24 degrees C. The resistance was paralleled by a humoral neutralising factor(s) in the plasma of shrimp.

Animals↗
PubMed2002

Appropriate cerebral perfusion pressure during rewarming after therapeutic hypothermia.

This study evaluated the cerebral ischemic parameters during the rewarming period after therapeutic hypothermia to determine the critical cerebral perfusion pressure (CPP) threshold to avoid ischemic deterioration. Cat experimental head injury was induced by inflation of an epidural rubber balloon to maintain intracranial pressure at 30 mmHg under hypothermia. During the rewarming period, CPP was maintained at > or = 120 mmHg, 90 mmHg, and 60 mmHg by controlling the blood pressure. CBF, CMRO2, AVDO2, and cerebral venous oxygen saturation (ScvO2) were measured. Brain extracellular glutamate concentrations were also measured by a dialysis electrode. Histological preparations of all brains were examined under an electron microscope. The cerebral metabolic parameters in animals with CPP of more than 90 mmHg returned to the base values after rewarming. However, ScvO2 was significantly lower (27 +/- 6%) and AVDO2 was significantly higher (9.4 +/- 1.8 ml/100 g/min) after rewarming in the animals with CPP = 60 mmHg, which indicated misery perfusion. Animals with CPP = 60 mmHg also showed increased extracellular glutamate concentration and histological ischemic damage (mitochondrial swelling). CPP of 60 mmHg during the rewarming period is associated with irreversible ischemia, which indicates continuation of cerebral vasoconstriction. Therefore, a CPP of greater than 90 mmHg is required to avoid cerebral ischemia.

Animals↗
PubMed2002

Quantitative local cerebral blood flow change after cerebrospinal fluid removal in patients with normal pressure hydrocephalus measured by a double injection method with N-isopropyl-p-[(123)I] iodoamphetamine.

The efficacy of cerebrospinal fluid (CSF) shunting surgery for normal pressure hydrocephalus (NPH) is difficult to predict. The CSF removal test is useful but quantification of the results is difficult. A method to quantitatively measure cerebral blood flow (CBF) by single photon emission computed tomography twice within 30 min after double injection of N-isopropyl-p-[(123)I] iodoamphetamine using a background subtraction method to correct for the temporal profile was utilized in tandem with CSF removal via a lumbar spinal tube in 22 patients of NPH to produce maps of baseline CBF and quantitative CBF change after CSF removal. All 22 patients with NPH underwent ventriculoperitoneal shunting surgery and were divided into two groups according to improvement in clinical symptoms and signs (responder group, N=15; nonresponder group, N=7). Baseline clinical characteristics and baseline CBF values were not significantly different between the two groups. Regional and whole brain CBF changes in the responder group (range 98-105%, whole brain 101+/-39%) were significantly higher than those in the nonresponder group (range 41-48%, whole brain 46+/-40%) (P<0.01). Discrimination analysis showed that an increase of more than 80% in CBF after CSF removal was predictive of response to shunt surgery with 77% accuracy. This new quantitative CSF removal test could be useful for selecting good candidates for CSF shunting surgery among patients with NPH.

Aged↗
PubMed2002

Tracking of a bronchoscope using epipolar geometry analysis and intensity-based image registration of real and virtual endoscopic images.

This paper describes a method for tracking the camera motion of a flexible endoscope, in particular a bronchoscope, using epipolar geometry analysis and intensity-based image registration. The method proposed here does not use a positional sensor attached to the endoscope. Instead, it tracks camera motion using real endoscopic (RE) video images obtained at the time of the procedure and X-ray CT images acquired before the endoscopic examination. A virtual endoscope system (VES) is used for generating virtual endoscopic (VE) images. The basic idea of this tracking method is to find the viewpoint and view direction of the VES that maximizes a similarity measure between the VE and RE images. To assist the parameter search process, camera motion is also computed directly from epipolar geometry analysis of the RE video images. The complete method consists of two steps: (a) rough estimation using epipolar geometry analysis and (b) precise estimation using intensity-based image registration. In the rough registration process, the method computes camera motion from optical flow patterns between two consecutive RE video image frames using epipolar geometry analysis. In the image registration stage, we search for the VES viewing parameters that generate the VE image that is most similar to the current RE image. The correlation coefficient and the mean square intensity difference are used for measuring image similarity. The result obtained in the rough estimation process is used for restricting the parameter search area. We applied the method to bronchoscopic video image data from three patients who had chest CT images. The method successfully tracked camera motion for about 600 consecutive frames in the best case. Visual inspection suggests that the tracking is sufficiently accurate for clinical use. Tracking results obtained by performing the method without the epipolar geometry analysis step were substantially worse. Although the method required about 20 s to process one frame, the results demonstrate the potential of image-based tracking for use in an endoscope navigation system.

Algorithms↗
PubMed2002

Right stereoisomers for sex pheromone components of the apple leafminer, Lyonetia prunifoliella, in Korea.

The sex pheromone of the American population of Lyonetia prunifoliella (Lepidoptera: Lyonetiidae) was reported to be composed of three components, 10,14-dimethyloctadec-1-ene (10me14me-1-ene-18Hy), 5,9-dimethyloctadecane (5me9me-18Hy), and 5,9-dimethylheptadecane (5me9me-17Hy). Studies with a Korean population showed that the 10S, 14S isomer of the major compound was the major electrophysiologically by active stereoisomer. The 5S,9S isomers of the minar constituents also elicited electrophysiological responses. In field trappings, among the three components, the racemic mixture of 10me14me-1-ene-18Hy attracted L. prunifoliella males strongly, and the binary or tertiary combinations with racemic mixtures of the other two components did not increase trap catches. Among the four stereoisomers of 10me14me-1-ene-18Hy, only the 10S,14S isomer attracted L. prunifoliella males, as suggested by the EAG test, and attraction to the other three isomers was not observed. All stereoisomers of each minor component, as well as their racemic components, did not seem to have any additional effect on male attraction in Korea.

Animals↗
PubMed2002

Interferon retreatment reduces or delays the incidence of hepatocellular carcinoma in patients with chronic hepatitis C.

Inhibition of hepatocarcinogenesis is a crucial issue in treating chronic hepatitis C patients, especially those who do not respond completely to interferon therapy. Interferon has been reported to reduce the incidence of hepatocellular carcinoma (HCC) not only in sustained virological responders but also in transient biochemical responders. However, the incidence of HCC increases in 5 years or more after interferon therapy in transient biochemical responders. The aim of this study is to assess whether interferon retreatment reduces the incidence of HCC in chronic hepatitis C patients in whom hepatitis C virus was not eradicated during initial interferon therapy. We enrolled 309 patients who were not sustained virological responders after initial interferon treatment consisting of a total dose of more than 250 megaunits of interferon and were followed for more than 2 years after treatment. Ninety-nine patients received interferon retreatment and 210 did not. Two courses of interferon therapy were administered in 84, three courses in 14 and five courses in one. The incidence of HCC was compared between patients with retreatment and those without. In the clinical characteristics, retreated patients were younger and followed up for a longer time period. The cumulative incidence of HCC was significantly lower in retreated patients. In multivariate analysis, patients' age (P=0.018) and the number of courses of interferon therapy (P=0.022) were independently associated with HCC incidence. These results suggest that interferon retreatment reduces or delays the incidence of HCC in chronic hepatitis C patients who did not completely respond to initial therapy.

Adult↗
PubMed2002

Effects of anticholinergic drug withdrawal on memory, regional cerebral blood flow and extrapyramidal side effects in schizophrenic patients.

It has been suggested that anticholinergic drugs impair immediate memory and working memory in patients with schizophrenia. Opinions remain divided as to the influence of anticholinergic drug withdrawal on the psychopathology and extrapyramidal side effects (EPS) in these patients. In our previous study, regional cerebral blood flow (rCBF) was reduced in all regions of patients taking anticholinergic drugs. Anticholinergic drugs were withdrawn in 21 schizophrenic inpatients. Immediate and verbal working memory, rCBF, psychopathology, and EPS were investigated before and after anticholinergic withdrawal. There was improvement in immediate memory, verbal working memory, and psychopathology, as well as an increase in rCBF after withdrawal from anticholinergic drugs. EPS showed no significant changes. Factors that may predict the improvement of immediate memory after withdrawal of anticholinergic drugs are more severe baseline psychopathology and use of a higher anticholinergic drug dose at baseline. Improvement of working memory may be predicted by a higher baseline rCBF in the left anterior cerebral artery region. Withdrawal from anticholinergics should be considered in schizophrenic patients, and it is important to taper these drugs over at least four weeks.

Adult↗
PubMed2002

Dissecting aneurysm confined to the anterior cerebral artery.

Dissecting aneurysm confined to the anterior cerebral artery (ACA) is extremely rare. Four patients presented with dissecting aneurysms confined to the ACA, two with cerebral infarctions in the territories of the ACA and two with subarachnoid haemorrhages. The two patients with infarction were treated by conservative therapy with anti-platelet therapy and the two patients with subarachnoid haemorrhage were treated by wrapping surgery in the early period after the ictus. Conservative treatment for patients with infarction and early wrapping surgery for patients with subarachnoid haemorrhage are recommended.

Adult↗
PubMed2002

Craniofacial morphology in preschool children with sleep-related breathing disorder and hypertrophy of tonsils.

UNLABELLED: The purpose of this study was to examine craniofacial morphology, pharyngeal airway space and hyoid bone position in preschool children with sleep-related breathing disorder associated with hypertrophy of tonsils (SBDT). Thirty-eight preschool children, mean age 4.7 y, with SBDT and with an apnoea index (AI) of 0 < AI < 5, were divided into two groups. One consisted of 15 children with sleep-related breathing disorder (SBD) and more than 75% of the tonsils visible (GIII) and the other of 23 children with SBD and 25-75% of the tonsils visible (GII). The control group consisted of 31 children without ear, nose and throat disease and with GI (barely visible) tonsils. Compared with the controls, GIII children had a retrognathic mandible, a large posterior facial height, a large interincisal angle with retroclined lower incisors, a narrow pharyngeal airway space, an anterior tongue base position and a long soft palate. Compared with the controls, GII children had a large anterior lower facial height and a short nasal floor. However, like the controls, GII children did not have a retrognathic mandible. CONCLUSION: The findings show that children with SBDT display a characteristic facial appearance at an early age. Since the condition has an effect on growth, it needs to be prevented by controlling morphology and function at the preschool age.

Case-Control Studies↗
PubMed2002

Effects of xenon on acetylcholine release in the rat cerebral cortex in vivo.

BACKGROUND: We have reported previously the effects of several anaesthetics on cholinergic activity in the central nervous system (CNS). In this study, we report the effects of xenon on cholinergic cell activity. METHODS: Using in vivo brain microdialysis, we measured acetylcholine (ACh) release in the rat cerebral cortex in vivo during xenon anaesthesia. RESULTS: Xenon induced an initial increase in ACh release, followed by a gradual decrease. The level of Ach release at 40 min of xenon administration was significantly higher than the control. CONCLUSIONS: Xenon activates CNS cholinergic cell activity followed by development of acute tolerance.

Acetylcholine↗
PubMed2002

Behavioural and pharmacological relevance of stroke-prone spontaneously hypertensive rats as an animal model of a developmental disorder.

The present study evaluates juvenile stroke-prone spontaneously hypertensive rats (SHRSP) as an animal model of a developmental disorder, which is diagnosed according to hyperactivity-impulsivity and/or inattention. To characterize behavioural alterations, we studied motor activity, as well as emotional and cognitive behaviours in juvenile SHRSP, with and without methylphenidate, a psychostimulant. Ambulatory and rearing activities in the open-field environment were significantly higher in SHRSP than in Wistar-Kyoto rats (WKY). In the elevated plus maze task, the entries into open arms, as an index of impulsivity, were significantly increased in SHRSP. In the Y-maze task, spontaneous alternation behaviour, as an index of attention, was significantly lowered in the male SHRSP, but not in the female SHRSP, indicating that spontaneous alternation deficit is gender specific. Methylphenidate (0.01-1 mg/kg, i.p.) significantly attenuated locomotor hyperactivity at low doses and dose-dependently improved the spontaneous alternation deficit in SHRSP. Our findings reveal that juvenile SHRSP manifest problematic behaviours resembling a developmental disorder, attention-deficit/hyperactivity disorder (ADHD), namely hyperactivity-impulsivity and/or inattention. Methylphenidate alleviated the behavioural symptoms of hyperactivity and inattention. We propose that juvenile SHRSP are an appropriate animal model of a developmental disorder resembling ADHD, from behavioural and pharmacological perspectives.

Animals↗
PubMed2002

[Synchronous tumors consisted of bronchial carcinoid and adenocarcinoma of the lung].

We report a case of synchronous tumors consisted of bronchial carcinoid and adenocarcinoma of the lung. A 58-year-old female was referred to our hospital after screening, because an abnormal shadow was noted in the right lung on her computed tomography (CT) of the chest. CT scans showed a peripheral pulmonary mass in the right middle lobe and a nodule around the right lower lobe bronchus. The nodular lesion like swollen lymph node was diagnosed as bronchial carcinoid originated in B6 by bronchoscopy. The pulmonary mass was diagnosed as adenocarcinoma by using core needle biopsy during operation. Right middle and lower bilobectomy and mediastinal lymph node dissection were performed. Coincidence of a bronchial carcinoid and an adenocarcinoma of the same side of the lung is a rare occurrence.

Adenocarcinoma↗
PubMed2002

Characterization of type 1851 organism isolated from activated sludge samples.

Five orange pigmented filamentous strains of Eikelboom's type 1851 were isolated from bulking activated sludge, and were examined for their phylogenetic lineage, morphology, and physiology. The analysis of 16S rDNA sequence revealed that the isolates belong to Chloroflexus subdivision in green non sulfur bacteria. They shared most common features with type 1851, but the result of gram stain was negative. Furthermore, they showed polymorphic nature and gliding motility, which could not be seen in activated sludge samples. General physiological tests were conducted under aerobic conditions although they could also grow by fermentation. Good growth was generally seen on sugars. The extremely slow growth rate (0.48-0.93 day(-1)) suggests the stimulation of this type exclusively in long SRT systems fed with sugars.

Biomass↗
PubMed2001

XBP1 mRNA is induced by ATF6 and spliced by IRE1 in response to ER stress to produce a highly active transcription factor.

In yeast, the transmembrane protein kinase/endoribonuclease Ire1p activated by endoplasmic reticulum stress cleaves HAC1 mRNA, leading to production of the transcription factor Hac1p that activates the unfolded protein response (UPR). In mammals, no Hac1p counterpart has yet been discovered despite the presence of Ire1p homologs in the endoplasmic reticulum. Instead, the transcription factor ATF6 specific to the mammalian UPR is regulated by intramembrane proteolysis. Here, we identified the transcription factor XBP1, a target of ATF6, as a mammalian substrate of such an unconventional mRNA splicing system and showed that only the spliced form of XBP1 can activate the UPR efficiently. Our results reveal features of the UPR conserved during evolution and clarify the relationship between IRE1- and ATF6-dependent pathways.

Activating Transcription Factor 6↗