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Biomedical subjects

M Kato

Publications and source records attributed to M Kato.

At least 415 records · Page 23Linked to original sources
PubMed2000

Enzyme immunoassay for autoantibodies to human liver-type arginase and its clinical application.

BACKGROUND: Arginase is an enzyme of the urea cycle, and one of the two isoenzymes is the liver-type enzyme. We examined serum autoantibodies to this liver-type enzyme in patients with hepatitis. METHODS: Antibodies to recombinant human liver-type arginase were measured by ELISA in 95 patients and 55 healthy controls. RESULTS: The mean absorbance values in the ELISA assays of patients with definite autoimmune hepatitis (n = 11; P <0.0001), probable autoimmune hepatitis (n = 31; P <0.0001), and hepatitis C (HCV; n = 20; P <0.01) were significantly different from those of healthy controls, but the values in patients with hepatitis B (HBV; n = 23) and other autoimmune diseases (n = 10) were not significantly different from those of healthy controls. When the cutoff was fixed at the upper 95th percentile of the absorbance value in healthy controls, positive reactions were found in 18.2%, 32.3%, 20.0%, 13. 0%, and 10.0% of patients with definite autoimmune hepatitis, probable autoimmune hepatitis, HCV hepatitis, HBV hepatitis, and other autoimmune diseases, respectively. All of these positive reactions were abolished by inhibition of serum with recombinant antigen. The specificity and sensitivity of this ELISA were 96% and 29%, respectively. The intraassay and interassay coefficients of variation were 2.3-7.5% and 9.8-11%, respectively. There was no relationship between these antibodies and anti-nuclear, anti-smooth muscle, or anti-cytochrome P450IID6 antibodies. CONCLUSIONS: The ELISA for anti-liver-type arginase autoantibody improved the detectability of autoimmune hepatitis when compared with established assays for liver-specific autoantibodies.

Arginase↗
PubMed2000

Premorbid risk factors for alcohol dependence in antisocial personality disorder.

BACKGROUND: Many, but not all, types of antisocial personality disorders (ASP) are complicated by alcohol dependence. Therefore, some additional risk factors may exist for alcohol dependence co-occurring with ASP. We studied whether severe childhood conduct disorder and a family history of alcohol dependence are possible risk factors for the development of alcohol dependence in ASP. METHODS: The subjects were 81 male Japanese criminals diagnosed with DSM-III-R ASP. Relative risks of alcohol dependence for severe conduct disorder and for a positive family history were estimated by using a multiple logistic model. RESULTS: Forty-three subjects (53.0%) met criteria for DSM-III-R alcohol dependence. The relative risk of alcohol dependence for severe conduct disorder (n = 44), compared with mild conduct disorder, was 4.1; whereas the relative risk for a positive family history (n = 31), relative to a negative family history, was 1.9. Severe childhood conduct disorder was also associated with severe adulthood antisocial behavior and an earlier onset of alcohol dependence. CONCLUSIONS: The results suggest that severe childhood conduct disorder and a positive family history of alcohol dependence are independent premorbid risk factors for developing alcohol dependence among persons with ASP.

Adult↗
PubMed2000

Artocarpus (Moraceae)-gall midge pollination mutualism mediated by a male-flower parasitic fungus.

A previously undescribed pollination system involving a monoecious tree species, Artocarpus integer (Moraceae), pollinator gall midges, and fungi is reported from a mixed dipterocarp forest in Sarawak, Borneo. The fungus Choanephora sp. (Choanephoraceae, Mucorales, Zygomycetes) infects male inflorescences of A. integer, and gall midges (Contarinia spp., Cecidomyiinae, Diptera) feed on the fungal mycelia and oviposit on the inflorescence. Their larvae also feed on the mycelia and pupate in the inflorescence. The gall midges are also attracted by female inflorescences lacking mycelia, probably due to a floral fragrance similar to that of male inflorescences. Because of the sticky pollen, dominance of Contarinia spp. in flower visitors, and pollen load observed on Contarinia spp. collected on both male and female inflorescences, Artocarpus integer is thought to be pollinated by the gall midges. Although several pathogenic fungi have been reported to have interactions with pollinators, this is the first report on a pollination mutualism in which a fungus plays an indispensable role. The pollination system described here suggests that we should be more aware of the roles fungi can play in pollinations.

Journal Article↗
PubMed2000

Sonic hedgehog signal peptide mutation in a patient with holoprosencephaly.

We investigated the molecular basis of holoprosencephaly in a sporadic patient and identified a novel missense mutation in the signal sequence of the sonic hedgehog (Shh) gene. Magnetic resonance imaging of the head showed a lobar type of holoprosencephaly and partial agenesis of the anterior corpus callosum. He was treated for craniosynostosis at 7 months of age. All three exons of the Shh gene were amplified by polymerase chain reaction from genomic DNA of the patient and controls. Sequencing analysis of the polymerase chain reaction fragments, screened by single-strand conformation polymorphism analysis, revealed a heterozygous mutation of a T-to-C substitution at nucleotide position 50. This mutation predicted an amino acid replacement of leucine to proline at codon 17 located in the signal peptide of SHH protein. It probably disturbs the translocation of the protein into the endoplasmic reticulum and may lead to holoprosencephaly because of haploinsufficiency of Shh.

Adult↗
PubMed2000

Alcohol and aldehyde dehydrogenase genotypes in Korsakoff syndrome.

BACKGROUND: Previous studies have suggested a genetic predisposition to the development of Wernicke-Korsakoff syndrome (WKS), a neuropsychiatric syndrome commonly associated with alcoholism; however, little is known about this genetic risk factor. METHODS: To test the hypothesis that altered alcohol or aldehyde regulation is related to the development of WKS, the genetic polymorphisms of aldehyde dehydrogenase-2 (ALDH2) and alcohol dehydrogenase-2 (ADH2) were examined in 47 alcoholic subjects with WKS and compared with those of 342 alcoholic subjects without any WKS symptoms and 175 nonalcoholic controls. RESULTS: Although the frequencies of the ALDH2 genotypes and alleles did not differ significantly between alcoholic subjects with WKS and alcoholics without WKS, the ADH2*1/2*1 genotype and ADH2*1 allele were significantly increased in WKS. CONCLUSIONS: These findings suggest that the ADH2*1/2*1 genotype is a risk factor for the development of WKS in alcoholic patients.

Aged↗
PubMed2000

Nutritional pharmacotherapy of chronic liver disease: from support of liver failure to prevention of liver cancer.

Many patients with liver cirrhosis are in a state of protein and energy malnutrition and require careful nutritional support. Our research has revealed that approximately 30% of the patients have protein-energy malnutrition, 40% protein malnutrition, and 10% energy malnutrition; 20% are in a normal nutritional state. Supplementation with branched-chain amino acids alleviates chronic liver failure, improves the protein nutritional state, and subsequently prolongs survival. In contrast, therapeutic modalities for energy malnutrition have not yet been fully elucidated and await further studies. Improved survival of the cirrhotic patients essentially brings a higher incidence of hepatocellular carcinoma (HCC). A synthetic analogue of vitamin A (acyclic retinoid or 4,5-dehydrogeranyl geranoic acid) prevents at least the development of second primary tumors after curative treatment of preceding HCC. The mechanism of this cancer chemo-prevention is clonal deletion of premalignant and latent malignant cells by the retinoid. We describe our clinical experiences with these two nutritional pharmacotherapies of chronic liver diseases and review their basic mechanisms.

Amino Acids, Branched-Chain↗
PubMed2000

[Recent endoscopic treatment in gastroenterology].

Endoscopic diagnosis and treatment became to be necessary in gastroenterology for last two decades. Indication of endoscopic treatment is amazingly expanding because of developing new techniques and easy-to-use devices. Nowadays, the indication for endoscopic treatment includes the removal of foreign bodies in alimentary tract, the dilatation of stricture lesions by balloon or expandable metallic stent, the resection of polypoid and superficial tumors by polypectomy and EMR (endoscopic mucosal resection) techniques, the injection sclerotherapy and ligation method for gastroesophageal varices, the hemostasis of gastrointestinal hemorrhages by injection method or heat-burn method. In biliary and pancreatic area, there are some endoscopic treatments that are removal and destruction of stones in common bile duct, biliary and pancreatic drainage by tubing method. Our results of endoscopic resection for esophageal and gastric tumors are shown in this papers. In conclusion, complete resection that means histologically tumor negative of lateral and vertical margin of resected specimen is important to prevent recurrence of tumors after resection.

Digestive System Diseases↗
PubMed2000

A novel human multiple myeloma-derived cell line, NCU-MM-1, carrying t(2;11)(q11;q23) and t(8;22)(q24;q11) chromosomal translocations with overexpression of c-Myc protein.

A novel cell line, designated as NCU-MM-1, was established from a 66-year-old female patient with multiple myeloma (MM) that had shown rapid progression from solitary plasmacytoma to plasma cell leukemia. Interestingly, cytogenetic analysis including fluorescence in situ hybridization analysis disclosed that this cell line carried 2 kinds of chromosomal translocations involving immunoglobulin light chain (IgL) gene loci without the presence of 14q32 translocations (14q+). The Ig lambda locus juxtaposed to the c-MYC locus at 8q24 on the derivative (8) chromosome and a concomitant overexpression of the c-Myc protein was observed. On the derivative (11) chromosome, the Ig kappa locus was also fused to the chromosome 11q23 locus, which is known to be a nonrandom translocation breakpoint in mature B-cell malignancies. The NCU-MM-1 cell line may thus be useful not only for the identification of the responsible proto-oncogene(s) mapped to 11q23, deregulated by the Ig kappa enhancer sequences, but also for clarification of the molecular origin of MM lacking 14q+ chromosomes because IgL rearrangements can physiologically begin to occur in the pre-B-cell stage.

Aged↗
PubMed2000

[Helicobacter pylori infection and eradication].

H. pylori infection is associated with various gastroduodenal diseases such as gastritis, peptic ulcer, gastric cancer, gastric MALT lymphoma. H. pylori infection is suggested that it plays a role as protective factor not promoting factor for reflux esophagitis and GERD. Epidemiological studies showed lower prevalence of H. pylori infection in reflux esophagitis and Barrett's esophagus comparing the control. Increased occurrence of reflux esophagitis after curing of H. pylori infection was reported. However, the relationship between H. pylori infection and reflux esophagitis has not been actually made clear. Also the mechanism of reflux esophagitis occurrence after H. pylori eradication is not obscure.

Gastroesophageal Reflux↗
PubMed2000

[Severe lightning pain during spinal anesthesia in a patient with diabetic neuropathy].

A 71-year-old woman with diabetic neuropathy who had undergone amputation of the right lower leg for diabetic gangrene 4 years previously, experienced severe lightning pain in both legs during spinal anesthesia. She was scheduled for skin grafting for a burn ulcer on her left foot. Her preoperative physical examination revealed hypesthesia in both legs due to diabetic neuropathy. Spinal anesthesia was performed with a combined spinal-epidural needle at the L 4-5 interspace using 2.0 ml of 0.3% hyperbaric dibucaine in the left lateral position. The region of hypesthesia was spread below Th 4. Ten minutes later, she complained of severe lightning pain in both legs and midazolam 1 mg was administered intravenously against agitation. The severe lightning pain diminished after the administration of pentazocine 7.5 mg intravenously in the recovery room. There was no worsening of neurological findings 5 hours later when the effect of spinal anesthesia disappeared. This clinical picture seems to be different from that of reported cases of phantom limb pain during spinal anesthesia in which severe lightning pain occurred in both legs. This case suggests that patients with diabetic neuropathy might develop severe lightning pain during spinal anesthesia using dibucaine.

Aged↗
PubMed2000

Whole-bladder irradiation and doxorubicin-containing chemotherapy as successful treatment for a primary mucosa-associated lymphoid tissue lymphoma of the bladder.

Primary bladder lymphoma, a rare disease, is usually of the low-grade mucosa-associated lymphoid tissue (MALT) type. The best treatment approach for this disease remains unknown. We encountered a case of localized MALT lymphoma with a partial high-grade component in a 27-year-old Japanese man. Taking therapeutic efficacy and the quality of life of the patient into consideration, we treated him with a combination of doxorubicin-containing chemotherapy and 30-Gy whole-bladder irradiation. The patient had a complete remission and has been disease-free without serious adverse effects or sequelae for a year and a half since completion of the treatment. These observations suggest that a combination of systemic chemotherapy and relatively low-dose irradiation without a total cystectomy is effective for a MALT lymphoma of the bladder, even with a high-grade component.

Adult↗
PubMed2000

[A case of moyamoya disease presenting with geographic mislocation, person misidentification and fantastic confabulation].

A 52-year-old woman presented with geographical mislocation (misidentification for place), person misidentification and fantastic confabulation as a result of cerebral infarction. Head MRI demonstrated a focal lesion in the right frontal lobe. Cerebral angiogram demonstrated occlusion in the circle of Willis with moyamoya vessels. The neuropsychological examination revealed memory impairment and frontal lobe dysfunction. The patient's misidentification for place and person as well as confabulation lasted for 1.5 months since admission, then gradually disappeared. We speculate that there existed a common mechanism for these three symptoms; i.e., misidentification and confabulation were based upon the impaired interpretation of the small events and partial objects in the surrounding circumstances, which might interfere with the appropriate integration and judgments of the outside information in general. The impaired monitoring and frontal dysfunction caused by the right frontal lesion appeared to be responsible for causing her deficits.

Brain↗
PubMed2000

[The advantages and limitations of brain function analyses by PET].

PET has been proved to be a powerful tool for exploring the brain function. We discussed the advantages and limitations of PET for analyzing the brain function on the basis of our clinical and experimental experiences of functional imaging. A multimodality PET study measuring cerebral energy metabolism (CMRO2 and CMRglc), cerebral blood flow (CBF), oxygen extraction fraction (OEF) and neurotransmitter function (presynaptic and postsynaptic) opens up a closer insight into a precise pathophysiology of the brain dysfunction: In cerebral infarction, it reveals a state of "misery perfusion" in the acute stage, "luxury perfusion" in the intermediate stage, and proportionately decreased CBF and CMRO2 in the chronic stage. Neurotransmitter function may identify specifically a neuronal subgroup of dysfunction. Owing to the low temporal resolution of PET, a neuronal activity may propagate transsynaptically to remote areas during the period of scanning, resulting in an obscured primary site of the neuronal activity. Uncoupling between neuronal activities and cerebral energy metabolism/CBF may occur under a certain state of brain pathology, particularly after an acute destructive lesion, according to our experimental studies. Neurotransmitter function may reveal the effect of drugs on the brain function, and may be useful for developing a new method of drug therapy for brain diseases in the future.

Animals↗
PubMed2000

Effects of microiontophoretically-applied opioid peptides on Purkinje cells in the cat cerebellum.

AIM: The purpose of the present study was to examine the effects of microiontophoretically-applied opioid peptides on Purkinje cell of the cerebellum. METHODS: The effects of microiontophoretically-applied morphine, leucine-enkephalin (Leu-Enk), methionine-enkephalin (Met-Enk), and dynorphin 1-13 (Dyn) on the spontaneous discharge of Purkinje cells in the cerebellum of the anesthetized cat were examined. RESULTS: Microiontophoretic applications of Leu-Enk and morphine produced inhibitory and excitatory responses, respectively in Purkinje cells. Application of both morphine and Leu-Enk induced dose-dependent responses. The excitatory responses were antagonized by naloxone, whereas the inhibitory responses were not. Bicuculline, a GABA-A antagonist, completely abolished both the Leu-Enk- and morphine-induced-inhibitory responses. Iontophoretic application of Met-Enk and dyn produced inhibitory responses only. Met-enk- and dyn-induced inhibition was antagonized by naloxone. CONCLUSION: In Purkinje cell activity, microiontophoretically applied Leu-Enk- and morphine-induced excitation is connected with opiate receptors, whereas inhibition is related to the GABA receptor. However, Met-Enk and dyn produced only inhibitory effects via an opiate receptor in the cerebellum of cats.

Action Potentials↗
PubMed2000

Inferring genetic networks from DNA microarray data by multiple regression analysis.

Inferring gene regulatory networks by differential equations from the time series data of a DNA microarray is one of the most challenging tasks in the post-genomic era. However, there have been no studies actually inferring gene regulatory networks by differential equations from genome-level data. The reason for this is that the number of parameters in the equations exceeds the number of measured time points. We here succeeded in executing the inference, not by directly determining parameters but by applying multiple regression analysis to our equations. We derived our differential equations and steady state equations from the rate equations of transcriptional reactions in an organism. Verification with a number of genes related to respiration indicated the validity and effectiveness of our method. Moreover, the steady state equations were more appropriate than the differential equations for the microarray data used.

Computational Biology↗