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Biomedical subjects

K Morimoto

Publications and source records attributed to K Morimoto.

At least 145 records · Page 8Linked to original sources
PubMed1999

[Follow-up of children with early neonatal surgery of fetal hydrocephalus].

This is a retrospective study of patients with surgically treated antenatal diagnosed hydrocephalus. We conducted the study to elucidate the outcomes of the patients, as well as potential pitfalls in their care. A series of 51 patients underwent surgical intervention between 1987 and 1997. All lesions were diagnosed by antenatal ultrasound sonography. After the estimation of their lung maturation, they were delivered in early pregnancy stage and the operation had performed for hydrocephalus. 43 children could be followed-up. To estimate the morphological improvement from radiological examinations objectively, we compared cerebroventricular index (CVI) of pre-operation with that of post-operation. The result was that excellent improvement group was 18 cases, good improvement group was 13 cases, fair improvement group was 8 cases and poor improvement group was 4 cases. In 43 cases, 20 children also had myelomeningocele and in them the improvement of hydrocephalus was that excellent improvement group was 10 cases, good improvement group was 5 cases and fair improvement group was 5 cases. About motor function of 20 children with myelomeningocele, only 5 children were ambulatory with brace. Attending to the rest 23 children without myelomeningocele, 6 children in 8 excellent improvement cases and 6 children in 8 good improvement cases were ambulatory by themselves. But all 7 children belonging to fair and poor improvement groups were unambulatory. We concluded that it was necessary to improve dilated ventricle on the radiological examinations with surgical procedure in order to get better motor function, even semilobar and lobar holoprosencephaly.

Child Development↗
PubMed1999

[Urodynamic studies on the untethering of spinal lipoma in the children].

We performed conus untethering on 44 children with spinal lipoma. In this retrospective study, we studied urological examinations obtained in 36 consecutive patients. Urological examinations were ultrasonography of bladder and kidney, voiding cystourethrography (VCG), and urodynamic cystometry. In those of them, 6 patients had already had urinary dysfunction at preoperative stage, but 4 patients' spinal lipoma was one complication of cloaca exstrophy and 2 patients' spinal lipoma after repairment of their myelomeningocele. In the remaining 30 cases, 18 patients (60.0%) as the group 1 did not have urinary dysfunction and abnormality in any urological examinations. Another 7 patients (23.3%) as group 2 also did not have urinary dysfunction, but abnormal vesicoureteral reflux (VUR) was found out in their VCG examination. At postoperative stage, abnormal VUR resolved or improved in all these 7 cases, but one of them showed transient urinary retention. Two patients of 18 in the group 1 had to require clean intermittent self-catheterization at postoperative stage. These observations confirmed that children with spinal lipoma were more likely to present with urological findings, and so it was imperative that a diagnosis be made and treatment be instituted as early as possible.

Child, Preschool↗
PubMed1999

Effects of alcohol intake and low Km aldehyde dehydrogenase on hepatic function in a high hepatitis C virus-prevalent Japanese island population.

In Asians from the Pacific rim countries, alcohol sensitivity has been attributed mainly to a highly prevalent polymorphism in low Km aldehyde dehydrogenase (ALDH2). Chronic alcohol abuse may accelerate or aggravate the liver injury in chronic hepatitis C virus (HCV)-infected subjects. In this study, we examined the relationships among alcohol intake, ALDH2 genotypes, and liver injury in a high HCV-prevalent Japanese native island population. The ALDH2 genotypes are significantly associated with drinking habits. In HCV RNA positive subjects, serum alanine aminotransferase (ALT), as well as aspartate transaminase (AST) and gamma-glutamyl transpeptidase (GGT), were significantly higher in habitual drinkers than in nonhabitual drinkers. In male habitual drinkers, the ALDH2*1/*1 subjects had higher liver necroinflammatory scores than the ALDH2*1/*2 subjects in all groups classified as: I, anti-HCV-seronegative; II, anti-HCV-seropositive with negative HCV RNA; and III, HCV RNA positive, although scores for the latter two groups were not statistically significant because of limited sample size. It was suggested that the liver function might be affected by the interaction between the ALDH2 genotypes and alcohol intake. These findings indicate that HCV-infected ALDH2*1/*1 habitual drinkers are the major target for the prevention of alcoholic liver diseases.

Alcohol Drinking↗
PubMed1999

[Vein of Galen aneurysmal malformation: multi-staged feeder clipping in two neonatal cases with intractable heart failure].

The authors reported the surgical experience of two cases of vein of Galen aneurysmal malformation in the newborn, whose congestive high-output cardiac failure was intractable. Along with the intensive care to clinical manifestations of the heart failure, multi-staged feeder clipping was carried out to decrease the high-flow shunt of the malformation. As stages going on, heart failure was relieved gradually and cathecolamines were weaned. Although certain retardation became apparent in both cases, they are showing satisfactory development in the long-term follow up. By the recent advancement of the embolization technique, the embolization appears to have already taken place the treatment of choice for this malformation. According to the neonatal evaluation score of Lasjaunias, the embolization would no longer be recommendation in neonates, whose general condition scored less than eight points. The authors believe, based on our two cases, that multi-staged feeder clipping is one of the effective modality of treatment in neonates of the vein of Galen aneurysmal malformation with severe multiorgan failure.

Cardiac Output, High↗
PubMed1999

[Benzodiazepine receptor imaging in the brain: recent developments and clinical validity].

Recent developments of benzodiazepine receptor imaging (123I-Iomazenil SPECT and 11C-Flumazenil PET) in neuropsychiatric disorders were reviewed. In focal epilepsy, a number of previous studies have reported a decreased benzodiazepine receptor binding in epileptic foci and greater sensitivity compared to regional cerebral blood flow imaging, especially for diagnosis of medial temporal lobe epilepsy. These findings indicate clinical validity of benzodiazepine receptor imaging in focal epilepsy and may be related to the "disinhibition mechanism" in GABA/benzodiazepine systems underlying epilepsy. In panic disorder, abnormal benzodiazepine receptor bindings are recently demonstrated in the temporal, parietal or frontal cortex. Further studies would clarify the "benzodiazepine dysfunction hypothesis" in panic disorder.

Brain↗
PubMed1999

Self-reported alcohol-associated symptoms and drinking behavior in three ALDH2 genotypes among Japanese university students.

BACKGROUND: Alcohol abuse is one of the most serious health problems among young adults. Nearly half of the Japanese population is sensitive to alcohol due to a genetic polymorphism in low K(m) aldehyde dehydrogenase (ALDH2). In the present study, we investigated the effects of the ALDH2 genotype on both self-reported alcohol-associated symptoms and alcohol drinking behavior among Japanese university students. METHODS: The study subjects were 423 (389 males and 34 females) university students in a medical university. The subjects completed a questionnaire regarding self-reported alcohol-associated symptoms and alcohol drinking behavior. The ALDH2 genotype was determined through digestion of polymerase chain reaction (PCR) products by a restriction enzyme Ksp632I. The frequency of alcohol-associated symptoms generally increased in the order ALDH2*1/*1, ALDH2*1/*2, ALDH2*2/*2 among males. The frequency of those who drink > or = 5 days/week was less than 10% in all genotype groups. However, the frequency of those who drink 1-4 days/week was significantly higher in ALDH2*1/*1 than that in ALDH2*1/*2 and in ALDH2*2/*2. A similar tendency also was observed in females. Mean amounts of alcohol consumption per occasion in the three ALDH2 genotypes stratified by drinking frequency generally increased significantly in the order ALDH2*2/*2, ALDH2*1/*2, ALDH2*1/*1 in both sexes. The proportion of binge drinkers defined by those who drink ethanol of > or = 75 ml per occasion on average also increased in the order ALDH2*2/*2 (0.0%), ALDH2*1/*2 (9.8%), ALDH2*1/*1 (22.1%) among male drinkers (> or = 1 day/month). CONCLUSIONS: We for the first time demonstrated clear associations between the ALDH2 genotype, self-reported alcohol-associated symptoms, and alcohol drinking behavior among Japanese university students.

Adult↗
PubMed1999

[Germinal matrix hemorrhage and hydrocephalus in premature infants].

An analysis of 25 preterm infants with grade 3 or 4 intraventricular hemorrhage and surgically treated progressive hydrocephalus was undertaken to assess mortality, cognitive outcome and motor deficit. All patients underwent surgery at the author's institute since 1981 and represented 4.7% of all intraventricular hemorrhage in premature infants. Surgical procedure was initial placement of a miniature Ommaya's reservoir and conversion to a ventriculoperitoneal shunt diversion. Overall, outcomes were achieved in 64.7% of ambulatory and improvement of cerebroventricular index on follow-up CT image from 0.68 +/- 0.36% to 0.36 +/- 0.31%. The presence of intraventricular hemorrhage continues to be a major problem in low birth weight infants whose rate survival continues to increase as the major improvements in perinatal medicine. We feel that miniature Ommaya's reservoir is quite helpful in the treatment of posthemorrhagic hydrocephalus in the preterm infant who prove refractory to aggressive conservative therapy.

Cerebral Hemorrhage↗
PubMed1999

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents: special references to bacteria isolated between July 1996 and June 1997].

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in 20 facilities in Japan since July 1982. This paper describes the results obtained during period from July 1996 to June 1997. The number of cases investigated as objectives was 217 for one year. A total of 406 strains were isolated from 177 cases (81.6% of total cases). From primary infections 162 strains were isolated, and from postoperative infections 244 strains were isolated, respectively. From primary infections, anaerobic bacteria were predominant, while from postoperative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus spp. was the highest. In postoperative infections, the majority of them were Enterococcus faecalis, while in primary infections, many of them were Enterococcus avium. The isolation rate of Staphylococcus spp., especially from postoperative infections, followed that of Enterococcus spp. Among anaerobic Gram-positive bacteria, Peptostreptococcus spp. and Streptococcus spp. were commonly isolated from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by E. coli and Enterobacter cloacae. Among anaerobic Gram-negative bacteria, Bacteroides fragilis group was the majority of isolates from both types of infections. The isolation rate of aerobic Gram-negative bacillus has decreased with time, while those of anaerobes like B. fragilis group and of aerobic Gram-positive bacteria have gradually increased in both types of infections. We found vancomycin-resistant strains of neither Staphylacoccus aureus nor Enterococcus spp.; however, the MIC of arbekacin for one of strains of S. aureus was 100 micrograms/ml. Both the MIC90's of meropenem and imipenem/cilastatin against P. aeruginosa isolated in this term were 25 micrograms/ml, which were higher than those against the strains isolated in the previous years. Compared with the isolated strains in the year 1995, progress of resistance against carbapenem antibiotics was confirmed.

Anti-Bacterial Agents↗
PubMed1999

[Computed assisted area measurement using CT scans: clinical application for craniosynostosis in children].

This paper describes a method for obtaining intracranial area measurements using CT scans with a software for quantitative analysis of tracing data. A Toshiba CT 1010 scanner was used (120 kv, 10 mm slice thickness) to examine 13 children before and after cranioplastic surgery for craniosynostosis. Using Scion Image (Scion Corporation) with Intuos tablet system (WACOM), the intracranial space was measured at approximately same scanning level. Our findings show that the reverse pi and bilateral canthal advancement procedures usually carried out are associated with increased intracranial area, 4.5 +/- 2.1% and 12.0 +/- 8.3%, respectively. This measurement method should be further modified to intracranial volume gain by several surgical procedures.

Craniosynostoses↗
PubMed1999

[Spinal lipoma in children: analysis of magnetic resonance image for upward displacement of medullary-conus on 44 consecutive surgical cases].

Medullary conus-untethering operation was conducted on 52 infants with spinal lipoma. Magnetic resonance (MR) image was used in order to evaluate the untethering results in 44 out of these 52 patients who could be followed-up after Osaka Medical Center & Research Institute for Maternal & Child Health was opened. Talking into account the changes in vertebral body during the growth period of infants, the authors studied the upward displacement of the conus-lipoma interface by four fractional MR sagittal image, using the vertebral body-intervertebral disc space as the baseline. Upward displacement was confirmed in 27 of 44 (61.4%). The mean, median and trimmed mean of upward displacement were 1.78 +/- 0.80, 2.0, 1.70 fractions, respectively. Sixteen (59.3%) were caudal type, 10 (37.0%) were transitional type and 1 (3.7%) was dorsal type. By type of spinal lipoma, upward displacement was observed in 16 of 23 caudal type patients (69.6%), 10 of 16 transitional type patients (62.5%) and 1 of 5 dorsal type patients (20%). While the rate of upward displacement was almost equal between the caudal and transitional type, that of dorsal type was lower. However, statistical analysis for the difference in population percentage of the three groups showed that significant difference existed only in the caudal type group.

Female↗
PubMed1998

A behavioral and immunohistochemical study on the development of perirhinal cortical kindling: a comparison with other types of limbic kindling.

We have previously reported that the perirhinal cortex (PRC) plays an important role in the generalization of kindled seizures. In the present study, we kindled the rat PRC and made a comparison with amygdala (AM) and dorsal hippocampal (dHIPP) kindling. In order to produce a functional map of the seizure generalization pathway from these limbic foci, we also stained for Fos protein in sections of the PRC-, AM- and dHIPP-kindled brains using an immunohistochemistry technique. In the generalized seizures of PRC kindling the duration of afterdischarges (ADs) and the latency to forelimb clonus were significantly shorter than those of AM kindling or dHIPP kindling. Typically, the PRC-kindled rats demonstrated moving arrest or exploratory behavior for about 10 days, and then a characteristic 'rapid backward moving' behavior for 1 day, followed by the sudden appearance of generalized motor seizures. Fos protein induction after a single stimulation of the PRC is more widely observed than after a single stimulation of the AM, in that the PRC stimulation produced Fos protein expression in the temporal and parietal neocortices. Following AM and PRC kindling, the Fos-positive areas were asymmetrically propagated from the ipsilateral to the contralateral hemisphere. The contralateral PRC was primarily activated at the generalization of epileptic activity in the contralateral hemisphere. In contrast, the Fos protein distribution of the dHIPP-kindled rats was restricted to the bilateral hippocampi during the early stages, followed by the symmetrical propagation from the limbic system to the neocortex during the generalized seizures. These results indicate that the PRC plays a characteristic role in the seizure generalization of kindling.

Amygdala↗
PubMed1998

Rabies virus quasispecies: implications for pathogenesis.

Passage of the mouse-adapted rabies virus strain CVS-24 (where CVS is challenge virus standard) in BHK cells results in the rapid selection of a dominant variant designated CVS-B2c that differs genotypically and phenotypically from the dominant variant CVS-N2c present in mouse-brain- or neuroblastoma-cell-passaged CVS-24. The glycoprotein of CVS-B2c has 10 amino acid substitutions compared with that of CVS-N2c. Because CVS-B2c can be reproducibly selected in BHK cells, it is likely to be a conserved minor subpopulation of CVS-24. CVS-N2c is more neurotropic in vitro and in vivo than CVS-B2c, which replicates more readily in nonneuronal cells in vitro and in vivo. These characteristics appear to be relevant to the pathogenicity of the two variants. CVS-N2c is more pathogenic for adult mice than CVS-B2c. In contrast, CVS-B2c is more pathogenic for neonatal mice. These differences in pathogenicity are reflected in the selection pattern when mixtures of CVS-N2c and CVS-B2c were used to infect neonatal and adult mice. Although CVS-N2c was highly selected in adult mice, no selection for either variant was seen in neonates, suggesting that certain aspects of development, such as maturation of the nervous and immune systems, may contribute to the selection process. We speculate that the existence of different variants within a rabies virus strain may facilitate the virus in overcoming barriers to its spread, both within the host and between species.

Age Factors↗
PubMed1998

Control of hemoglobin synthesis in erythroid differentiating K562 cells. II. Studies of iron mobilization in erythroid cells by high-performance liquid chromatography-electrochemical detection.

We have demonstrated that iron controls hemoglobin (Hb) synthesis in erythroid differentiating K562 cells by enhancing the activity of a key enzyme of the Hb synthesis, delta-aminolevulinate synthase (ALAS). In the present study, we studied iron mobilization and the role of iron in erythroid differentiating cells by measuring the level of iron by means of high-performance liquid chromatography using electrochemical detection (HPLC-ED). After treatment of K562 cells with sodium butyrate, the expression of transferrin receptor (TfR) increased initially, followed by an increase in the levels of both total iron and Hb as well as the ALAS activity. However, no increase could be found in the levels of non-heme iron, low-molecular-mass iron (LMMFe) and ferritin. Addition of diferric transferrin (FeTf) enhanced both delta-aminolevulinic acid (ALA) and Hb synthesis. In contrast, addition of hemin elevated the levels of all iron species as well as the Hb synthesis but reduced the TfR expression and ALA contents in both butyrate treated and untreated cells. These results suggest that Hb synthesis is controlled by TfR expression, and that the ALA synthesis is suppressed by iron released from heme and/or Hb due to lowered expression of TfR.

Cell Differentiation↗
PubMed1998

Time-dependent changes in rat hippocampal synapsin I mRNA expression during long-term potentiation.

We studied the time-dependent changes in synapsin I mRNA levels after hippocampal long-term potentiation (LTP) in rats in vivo. Following LTP induction by stimulating the perforant path, synapsin I mRNA expression in the granule cell layer of the dentate gyrus ipsilateral to stimulation increased significantly in a time-dependent manner. From 2 to 8 h after stimulation, the synapsin I mRNA levels in the ipsilateral dentate gyrus were significantly higher than those of controls subjected to a sham procedure. The synapsin I mRNA level (157.4+/-7.1% of the control level, mean+/-SEM) was at a maximum 8 h after stimulation. The synapsin I mRNA level of animals that received only test pulses did not increase significantly, compared with the control level. These results suggest that the increased level of synapsin I mRNA is related to persistent enhancement of synaptic activity within the neural networks in which dentate granule cells participate in LTP.

Animals↗
PubMed1998

Activation of adenosine A2 receptors enhances high K(+)-evoked taurine release from rat hippocampus: a microdialysis study.

The present study was designed to examine which type of adenosine receptors was involved in enhancement of high K(+)-evoked taurine release from in vivo rat hippocampus using microdialysis. Perfusion with 0.5 or 5.0 mM adenosine enhanced high K(+)-evoked taurine release. Perfusion with 2 microM R(-)-N6-2-phenylisopropyladenosine (PIA), a selective adenosine A1 receptor agonist, did not modulate taurine release. Perfusion with 1 microM 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), a selective adenosine A1 receptor antagonist, increased taurine release. On the other hand, perfusion with 20 microM 2-[4-(2-carboxyethyl)phenethylamino]-5'-N-ethyl-carboxamide-adenos ine (CGS21680), a selective adenosine A2A receptor agonist, enhanced taurine release, while perfusion with 1 mM 3,7-dimethyl-propagylxanthine (DMPX), an adenosine A2 receptor antagonist, did not affect taurine release. These results demonstrate that adenosine enhances high K(+)-evoked taurine release via activation of adenosine A2A receptors from both neurons and glial cells of in vivo rat hippocampus.

Adenosine↗
PubMed1998

Perioperative changes in plasma brain natriuretic peptide concentrations in patients undergoing cardiac surgery.

The plasma concentrations of brain natriuretic peptide (BNP), a cardiac hormone, were measured in 30 consecutive adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) during the perioperative period. BNP concentrations remained unchanged until 6 h after the cessation of bypass, and were elevated 12, 24, and 48 h post-bypass (P < 0.0001 versus baseline). They had returned to the baseline values when measured 3 weeks postoperatively. The preoperative plasma BNP concentration correlated significantly with the left ventricular ejection fraction (r = -0.895). The peak plasma BNP concentration 24 h after bypass correlated with the cardiac index (r = -0.64), stroke volume index (r = -0.62), injection rate of dopamine hydrochloride (r = 0.65), and aortic crossclamp time (r = 0.57). There was also a significant correlation between the preoperative BNP concentration and the plasma BNP concentration 24 h post-CPB. These findings led us to conclude that the plasma concentrations of BNP become markedly and acutely elevated after cardiac surgery with CPB, and reflect the state of left ventricular function. Moreover, the severity of acute heart failure after cardiac surgery can be predicted by the preoperative plasma BNP concentration.

Cardiac Surgical Procedures↗