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Biomedical subjects

A Matsui

Publications and source records attributed to A Matsui.

At least 127 records · Page 7Linked to original sources
PubMed1997

Molecular analysis of minimally differentiated acute myeloid leukemia with chromosome 16 inversion.

We report a 3-year-old girl with minimally differentiated acute myeloid leukemia and chromosome 16 inversion (inv 16). Inv 16 is generally associated with acute myelomonocytic leukemia with dysplastic eosinophils in the bone marrow (AML-M4Eo). Recently, molecular analysis showed that a fusion gene is generated by this inversion between the CBFB gene on the q arm and the MYH11 gene on the p arm. Using reverse transcriptase-polymerase chain reaction analysis, we tried to detect CBFB/MYH11 chimeric mRNA in blasts from our patients, however, were unable to detect any chimeric mRNA in the blasts: The absence of CBFB/MYH11 transcripts in this case suggests that rare chimeric products might be formed as a result of inv 16 that could not be detected by the primer sets used in this study. Another possibility is that different genes are rearranged on the chromosome 16 with the inv 16. More detailed molecular analysis of this case might be necessary in order to elucidate these possibility. Analyzing leukemias with inv 16 which do not have a typical CBFB/MYH11 chimeric mRNA might lead to understanding an alternative pathogenesis for acute leukemia with inv 16.

Acute Disease↗
PubMed1996

Geographic population structure and sequence divergence in the mitochondrial DNA control region of the Japanese wild boar (Sus scrofa leucomystax), with reference to those of domestic pigs.

Mitochondrial DNA (mtDNA) control regions from 40 Japanese wild boars were examined by direct sequencing after amplification by PCR. From the DNA sequences obtained, we found eight haplotypes, whose differences arose via transitions. The geographical distribution of these different haplotypes indicated that wild boar populations inhabited limited areas and that there was some restricted gene flow between local populations. Eight mtDNA haplotypes from Eastern and Western domestic pigs and the Ryukyu wild boar were also analyzed as references to those from Japanese wild boars. The cluster analyses of the control-region sequences showed that those from Japanese wild boars belong to the Asian type as do those from Eastern domestic pigs and the Ryukyu wild boar, which differed from the European type (Western domestic pigs).

Animals↗
PubMed1996

Somatosensory afferent inputs release 5-HT and NA from the spinal cord.

Endogenous serotonin (5-HT) and noradrenaline (NA) release by somatosensory afferent inputs was investigated at the level of the spinal cord using in vivo microdialysis technique combined with high performance liquid chromatography and electrochemical detection (HPLC-ECD). Selective stimulation of large myelinated A beta afferent fibers significantly increased 5-HT release to 151.1 +/- 10.1% of the control, but did not affect NA release. However, selective stimulation of small myelinated A delta fibers released NA rather than 5-HT. The NA level enhanced to 128.8 +/- 6.4% of the control after A delta fibers were stimulated with the intensity of 6 times threshold. Stimulation of unmyelinated C fibers unavoidably excited the A beta and A delta afferent fibers, causing both 5-HT and NA release from the spinal cord. The results suggest that both innocuous and noxious information may activate serotonergic descending pathways. The noradrenergic descending pathways are only triggered by noxious inputs transmitted by small afferent fibers.

Afferent Pathways↗
PubMed1996

Painless thyroiditis occurring during long-term treatment with interferon alfa in a patient with chronic active hepatitis C.

We describe here painless thyroiditis during interferon (IFN) therapy in a 65-year-old man with chronic active hepatitis C. The patient had hypothyroidism in the late stage of a 24-week course of treatment with IFN-alpha. After cessation of the treatment a small, firm goiter was noticed, and chronic focal thyroiditis was diagnosed histologically. Analyses of the stock serum samples drawn before, during, and after IFN-alpha therapy revealed transient hyperthyroidism followed by transient hypothyroid states with aggravation of antithyroid hormone antibody titers. These findings suggest that long-term IFN-alpha therapy caused painless thyroiditis with aggravation of autoimmunity in our patient with preexisting chronic thyroiditis.

Aged↗
PubMed1996

Intra- and interbreed genetic variations of mitochondrial DNA major non-coding regions in Japanese native dog breeds (Canis familiaris).

Mitochondrial DNA (mtDNA) major non-coding regions were amplified from 73 dogs of eight Japanese native dog breeds and from 21 dogs of 16 non-Japanese dog breeds by the polymerase chain reaction and their DNA sequences were determined. A total of 51 nucleotide positions within the non-coding region (969-972 base pairs) showed nucleotide variations of which 48 were caused by transition. These nucleotide substitutions were abundant in the region proximate to tRNA(Pro). In addition to the nucleotide substitutions, the dog mtDNA D-loop sequences had a heteroplasmic repetitive sequence (TACACGTAGCG) involving size variation. The DNA sequences of the non-coding region were classified into four different groups by phylogenetic analysis and the deepest branchpoints of this dog phylogeny was calculated to about 100,000 years before the present. Phylogenetic analysis showed that Japanese native dog breeds could not be clearly delimited as distinct breeds. Many haplotypes found in members of some clustering groups were seen in each dog breed, and interbreed nucleotide differences between Japanese dog breeds were almost the same as the intrabreed nucleotide diversities.

Animals↗
PubMed1996

Apparently increased trough levels of tacrolimus caused by acute infantile diarrhea in two infants with biliary atresia after liver transplantation.

Two infants with biliary atresia who exhibited three-fold increased trough levels of tacrolimus and required reduced doses during episodes of acute infantile diarrhea within 5 months of liver transplantation are described. The cause of the increase was not explained simply by hemoconcentration as a result of significant loss of extracellular fluid during these episodes. It does highlight an important issue: that of the continuing need to carefully monitor the trough levels of tacrolimus in such infants.

Acute Disease↗
PubMed1996

Hyperreninemia, hypertension, and congestive heart failure in focal interstitial nephritis.

Hyperreninemia probably due to focal interstitial nephritis of the right kidney caused an acute onset of hypertension and cardiac dysfunction including valvular insufficiency in a 5-year-old boy. This congestive heart failure in association with valvular insufficiency and hypertension was dramatically improved following right nephrectomy. Abruptly activated renin-angiotensin II may lead to congestive heart failure and valvular dysfunction without myocardial hypertrophy in a young heart.

Aortic Valve Insufficiency↗
PubMed1995

Simultaneous determination of citalopram and its metabolites by high-performance liquid chromatography with column switching and fluorescence detection by direct plasma injection.

High-performance liquid chromatography with a successive column-switching technique was developed for simultaneous determination of citalopram and its four metabolites in plasma. Plasma samples were injected directly, and the target compounds were purified and concentrated with an inexpensive commercial octadecyl guard column. Then, the six-port valve was switched, and the compounds retained in the column were eluted by the back-flush method using 20 mM phosphate buffer (pH 4.6)-acetonitrile (70:30, v/v) containing 0.1% diethylamine and separated with an ODS column. The compounds were assayed with a fluorescence detector at an excitation wavelength of 249 nm and an emission wavelength of 302 nm. At least 30 plasma samples could be treated with an octadecyl guard column. The limits of quantitation of this method were 2.0 ng/ml for citalopram, desmethylcitalopram, didesmethylcitalopram, citalopram propionic acid and citalopram N-oxide. This method was applied to a pharmacokinetic study in dogs and a toxicokinetic study in rats.

Animals↗
PubMed1995

Use of prostaglandin I2 analog in treatment of massive hepatic necrosis associated with endothelial cell injury and diffuse sinusoidal fibrin deposition.

Endothelial cell damage causes massive hepatic necrosis as a result of fibrin deposition in the hepatic sinusoids. When a stable analog of prostaglandin I2, beraprost sodium, was administered to rats given either dimethylnitrosamine, carbon tetrachloride, or endotoxin following Corynebacterium parvum administration, the hepatic necrosis produced in each was attenuated, but to a greater extent in the dimethylnitrosamine and endotoxin/Corynebacterium parvum models, where fibrin deposition in the hepatic sinusoids occurs, as compared to the carbon tetrachloride model, where such fibrin deposition does not occur. Beraprost sodium reduced the expected increase of portal venous pressure in the endotoxin/Corynebacterium parvum model without affecting plasma thrombin-antithrombin III complex levels. Beraprost sodium also significantly reduced cell killing of both isolated rat hepatocytes and hepatic sinusoidal endothelial cells exposed to tert-butyl hydroperoxide when compared to controls. Beraprost sodium could prove to be a therapeutic candidate for the treatment of hepatic necrosis, particularly in cases associated with fibrin deposition in the hepatic sinusoids because of its fibrin clot-clearing action.

Animals↗
PubMed1995

Neuroendocrine tumors of the liver and pancreas associated with elevated serum prostatic acid phosphatase.

A 58-year-old man was revealed to have multiple liver tumors with elevated prostatic acid phosphatase (PAP) during a medical examination. The tumors were of neuroendocrine nature, but no abnormal findings were obtained in other organs in which neuroendocrine tumors develop frequently. Repeated transarterial embolization was partially effective. However, the tumors became resistant to the therapy three years later, continued growing and ruptured. Autopsy disclosed neuroendocrine tumors in the pancreas, which were immunohistologically positive for PAP. Neuroendocrine tumors of the pancreas and liver producing PAP are rare; this case is reported with a review of literature.

Acid Phosphatase↗
PubMed1995

Calculation models for average stress and plastic deformation zone size of bonding area in dentine bonding systems.

Average stress during shear bond testing, and deformation behaviour during nano-indentation testing were calculated for the bonding area as a bonding site for copolymerization with resin composite in dentine bonding systems. First average stress was calculated in the bonding area between bovine dentine and composite resin. Secondly, the plastic deformation zone size was calculated using an elastic/plastic deformation zone model after a nano-indentation test. The result clearly showed that average stress depended upon the elasticity of the bonding area, the elasticity value ratio of the composite resin-to-bonding area, and interfacial stress between the dentine and the adhesive resin. In this bonding area, the elasticity/hardness ratio changed depending on the thickness of the bonding area as well as the plastic deformation zone size (b), expressed as a (b/2a)-value (indented triangular length (2a) at nano-indentation test) expanded with increasing the elasticity value.

Animals↗
PubMed1994

Transmission of hepatitis C virus from mothers to infants. The Vertical Transmission of Hepatitis C Virus Collaborative Study Group.

BACKGROUND: Although there are case reports of vertical transmission of hepatitis C virus (HCV), it remains uncertain to what extent infected mothers transmit this virus to their infants. METHODS: We investigated the transmission of HCV from infected mothers to their babies by analyzing HCV RNA in the blood. Three independent studies were performed. First, 7698 parturient women were tested for anti-HCV antibodies; 53 were positive. Their 54 infants (including one set of twins) were followed prospectively for at least six months and tested for HCV disease were prospectively studied. Third, the families of three HCV-infected infants were examined retrospectively. RESULTS: Of the 53 antibody-positive mothers, 31 were also positive for serum HCV RNA: Three of the 54 babies born to these mothers (5.6 percent) became positive for HCV RNA during the follow-up period. None of the babies of the 22 women who were antibody-positive but HCV RNA-negative became positive for HCV RNA: In the second study, HCV RNA was detected in one of the six infants of infected mothers. In the third study, HCV RNA was detected in the mothers of the three HCV-infected infants. In each of the seven infected infants we studied, the genomic sequence of HCV was almost identical to that from the mother. These seven mothers had significantly higher titers of HCV RNA than did the mothers of infants with no evidence of infection (mean [+/- SD], 10(6.4 +/- 0.5) vs. 10(4.4 +/- 1.5) per milliliter; P < 0.001). CONCLUSIONS: HCV is vertically transmitted from mother to infant, and the risk of transmission is correlated with the titer of HCV RNA in the mother.

Adult↗
PubMed1994

Reversible hyperkalemia during antihypertensive therapy in a hypertensive diabetic patient with latent hypoaldosteronism and mild renal failure.

A 66-year-old hypertensive diabetic patient with latent hypoaldosteronism and mild renal failure was treated by adding enalapril, an angiotensin converting enzyme inhibitor, to the furosemide and nifedipine regimen because of an insufficient antihypertensive response for 1 month. Seven days after enalapril addition, the blood pressure was significantly reduced, but frank hyperkalemia occurred with a marked rise in BUN and a slight increase in serum creatinine. Plasma renin activity (PRA) and plasma aldosterone (PA) values remained low before and during enalapril therapy. Transient treatment with sodium polystyrene sulfate after enalapril withdrawal improved the hyperkalemia and renal function, but PRA and PA levels were low. PA and its precursor steroids also responded poorly to graded angiotensin II infusion and rapid ACTH injection. Latent hypoaldosteronism probably predisposed this patient to frank hyperkalemia with progressive dehydration and slightly reduced renal function during antihypertensive therapy.

Aged↗
PubMed1994

Factor IX Bm Kiryu: a Val-313-to-Asp substitution in the catalytic domain results in loss of function due to a conformational change of the surface loop: evidence obtained by chimaeric modelling.

Factor IX Kiryu is a naturally occurring mutant of factor IX that has 2.5% coagulant activity, even though normal plasma levels of factor IX antigen are detected. Factor IX Kiryu was purified from a patient's plasma by immunoaffinity chromatography with a calcium-dependent anti-factor IX monoclonal antibody column. It was cleaved normally by factor XIa in the presence of Ca2+, yielding a two-chain factor IXa. However, the resulting factor IXa showed only 1.5% of the normal factor IXa in terms of factor X activation in the presence of factor VIII, phospholipids, and Ca2+, and had 20% of the normal esterase activity for Z-Arg-p-nitrobenzyl ester. Therefore factor IXa Kiryu showed the defect of the catalytic triad or primary substrate binding site as well as defective interaction with factors VIII/X. Single-strand conformational polymorphism analysis and DNA sequencing of the amplified DNA revealed a missense point mutation, a T-to-A substitution at nucleotide number 31,059 of the factor IX Kiryu gene. This mutation resulted in the amino acid substitution of Val-313 by Asp in the catalytic domain. Restriction enzyme analysis of the amplified DNA showed that the mutation was inherited from the patient's mother. The chimaeric method was employed to construct a model of the serine protease domain of factor IXa, and the resultant model suggested that the Val-313 to Asp substitution altered the conformation of the substrate-binding site. These data combined with our previous findings on a Gly-311-to-Glu mutant of factor IX suggest that the loop conformation from Gly-311 to ARg-318 is important for the expression of coagulant activity.

Amino Acid Sequence↗