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Biomedical subjects

K Tamura

Publications and source records attributed to K Tamura.

At least 667 records · Page 37Linked to original sources
PubMed1994

Long-term prognosis of medically treated patients with acute myocardial infarction and one-vessel coronary artery disease.

Long-term prognosis was studied in 156 patients with acute myocardial infarction (AMI) with 1-vessel coronary artery disease (CAD). During a mean follow-up period of 110 months, 19 patients (14%) had reinfarction, 15 (9.6%) died (including 7 deaths of cardiac origin) and 15 (9.6%) were hospitalized for worsening of angina. A coronary arteriogram was obtained twice in 54 patients. The coronary arteriogram revealed multivessel CAD in all cases with reinfarction (n = 14). Ten percent of the patients with multivessel disease experienced a reinfarction during the initial 3 years after the onset of the first AMI. The recurrence rate of AMI in patients with 1-vessel disease increased gradually from the third year after the onset of their first AMI, reaching 10% in 6.7 years. The recurrence of AMI at the same region as the original infarction was detected in only 1 patient. Six of 19 patients (32%) with recurrence of AMI died and 13 survived after the reinfarction. It was difficult to predict future progression from the outcome of the comparison between the first and second coronary arteriograms. Thus, in patients with uncomplicated AMI with 1-vessel CAD, the prognosis is relatively good and the frequency of reinfarction is very low with conservative treatment.

Adult↗
PubMed1994

The effect of successful angioplasty on variables of signal-averaged electrocardiogram and ventricular wall motion in patients with a first myocardial infarction.

The correlation among three variables of late potentials (LPs) obtained by signal-averaged electrocardiography (SAECG) and improvement of ventricular wall motion estimated by echocardiography were studied in 66 patients with a first acute myocardial infarction (MI). Patients with bundle-branch block, intraventricular conduction delay, multi-vessel disease, previous MI, repeat percutaneous transluminal coronary angioplasty (PTCA), or evidence of reinfarction during a 6-month follow-up were excluded. A total of 66 patients was divided into two groups, with (Group 1: n = 27, age 56 +/- 11) or without (Group 2: n = 39, age 61 +/- 10) improvement of ventricular wall motion. Three variables of LPs and ventricular wall motion index (WMI) estimated and scored by echocardiography at admission (WMI 1) and at 6 months after MI (WMI 2) were compared in each group. In Group 1 (WMI 1 vs. WMI 2, p < 0.002), 20 of 27 patients underwent successful angioplasty; in Group 2 (WMI 1 vs. WMI 2, p = NS), 7 of 39 patients had successful emergency angioplasty. There were significant differences in three variables of LPs between the time of admission and at 6 months after MI in Group 1 but not in Group 2. Higher incidence of LPs and greater frequency of successful emergency PTCA were found in Group 1 compared with Group 2. These results suggest that because myocardial ischemia is reversed by successful angioplasty, ventricular wall motion is improved and the arrhythmogenic substrate that generates LPs is stabilized electrically. Stunned or hibernating myocardium may be the arrhythmogenic substrate that generates LPs.

Adult↗
PubMed1994

Chromosome 1q terminal deletion resulting from de novo translocation with an acrocentric chromosome.

Distal deletion of chromosome 1q has been reported in nearly 30 patients, all being associated with a deletion ranging from the 1q42 or q43 band to 1qter region. Here, we describe a girl with 1q terminal deletion resulting from an unbalanced de novo translocation t(1;D or G)(q44;p11), as revealed by the presence of a satellited feature and an NOR-stained region at the tip of 1q. We suggest that most of the phenotypic abnormalities seen in patients with 1q distal deletion are attributable to the monosomy for band 1q44.

Child, Preschool↗
PubMed1994

Elderly onset of adult Still's disease: report of a case.

Adult Still's disease is a variant of juvenile rheumatoid arthritis occurring most frequently in women 16-35 years of age, but rarely in elderly people. We describe a 75-year-old woman who was considered as having adult Still's disease.

Aged↗
PubMed1994

DNA fingerprint analysis of Dahl-Iwai salt-sensitive rats (S) and salt-resistant rats (R).

Using DNA fingerprint analyses, extensive molecular heterogeneity has been found between spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY), suggesting a doubtful value of simply comparing these rats in the study of the pathogenesis of genetic hypertension. Therefore, we evaluated the genetic similarity between Dahl salt-sensitive and salt-resistant rats newly inbred by Dr.Iwai (Dahl-Iwai S and R rats), by use of DNA fingerprint analysis. Fingerprint patterns were generated by probing Hinf I- or Alu I-digested DNA with an oligonucleotide corresponded to the tandem repeat sequence of the human myoglobin 33.6 minisatellite. These fingerprint patterns were same within each strain. S and R rts shared 82 percent of the bands in Hinf I-digested DNA and 93 percent of those in Alu I-digested DNA. Although Dahl-Iwai S and R rats are more closely related than SHR and WKY rats, multiple genetic differences still exist between these Dahl strains.

Animals↗
PubMed1994

Chronic subdural hematoma associated with middle meningeal arteriovenous fistula treated by a combination of embolization and burr hole drainage.

A rare case of chronic subdural hematoma associated with a middle meningeal arteriovenous fistula was treated by a combination of embolization and burr hole drainage. This clinical situation might be missed in this era of computed tomography, when cerebral angiography is seldom indicated for the diagnosis of neuro-traumatic diseases. We should bear in mind the possibility of this clinical situation of a chronic subdural hematoma associated with a linear skull fracture crossing the middle meningeal groove in order to avoid possible hemorrhagic complications during surgery for chronic subdural hematoma.

Arteriovenous Fistula↗
PubMed1994

Expression of functional Fas antigen on adult T-cell leukemia.

The expression of Fas antigen was analyzed in the peripheral blood mononuclear cells of 12 patients with adult T-cell leukemia (ATL) by flow cytometry. The induction of apoptosis in these cells by adding an anti-Fas antibody and the expression of activated T-cell surface antigens, CD25 and CD26, were also studied. It appears that the cells in ATL expressed a significantly larger number of Fas antigens than those in normal subjects (p < 0.01) and their fluorescent intensity was also shown to be much stronger in ATL (p < 0.01). The large number of ATL cells showed apoptosis in a short-term culture in the presence of the anti-Fas antibody. There was no difference in the expression of Fas antigen among ATL cells with different phenotypes of CD4+/CD8-, CD4-/CD8- and CD4+/CD8+ as well as with clinical subtypes of ATL. Interestingly, the expression of Fas and CD26 antigens showed a negative correlation (p < 0.01, r = 0.78). The strong expression of functional Fas antigen in ATL leads to the impression that anti-Fas antibody could be one of the treatment modalities for ATL which is known to be a very difficult disease to cope with.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1994

Differential gene expression of fibroblast growth factor receptor isoforms in rat ovary.

The gene expression of four fibroblast growth factor receptors (flg, bek, FGFR-3, and FGFR-4) in rat ovary cells was studied. Northern blot hybridization revealed that flg and bek mRNAs were detectable during all stages except a diestrus stage, whereas FGFR-3 and FGFR-4 mRNAs were almost undetectable throughout the cycles. In situ hybridization also demonstrated that only flg and bek gene expression was detectable. A modest flg mRNA signal was detected in developing antral follicles and it was more prominent in the theca-interstitial cells than in the granulosa cells. A modest to weak flg mRNA signal was seen in the hypertrophied theca-interstitial cells of atretic follicles and a very weak flg mRNA signal was observed in the corpora lutea. On the other hand, a weak bek mRNA signal was seen in granulosa and theca-interstitial cells in developing follicles and also hypertrophied theca-interstitial cells of atretic follicles, but not in the corpora lutea. Intense signals for both flg and bek mRNAs were unexpectedly found in the epithelium of paroophoron at the hilus. These results demonstrate that the bFGF receptor isoforms are expressed differentially in the rat ovary cells.

Animals↗
PubMed1994

Hepatic changes of mice in the subacute phase of streptozotocin (SZ)-induced diabetes.

Hepatic changes of mice in the subacute phase of streptozotocin (SZ)-induced diabetes were investigated biochemically and pathologically. Biochemically, the contents of serum glucose and of serum and liver lipids increased while the content of liver glycogen decreased in SZ-induced diabetic mice. Histopathologically, hypertrophy of hepatocytes due to an increase in number of intracytoplasmic acidophilic granules was common to SZ-induced diabetic mice. Electron microscopically, these hepatocytes were characterized by a prominent increase in number of mitochondria showing normal structure, a marked decrease of glycogen granules and poorly developed rough endoplasmic reticulum, which were common to so-called oncocytic cells. In some SZ-induced diabetic mice, bile duct hyperplasia with an appearance of cytomegalic hepatocytes was also observed.

Animals↗
PubMed1994

Plasma alpha 1-acid glycoprotein concentration in broilers: influence of age, sex and injection of Escherichia coli lipopolysaccharide.

1. The influence of age, sex and injection of Escherichia coli lipopolysaccharide (LPS) on the plasma concentration of alpha-1 acid glycoprotein (AGP) was determined in broilers using the single radial immunodiffusion method. 2. Plasma AGP concentration increased in the 3 d after hatching, and then stabilised at 240 +/- 33 micrograms/ml up to 14 d of age. 3. No sex-related differences in plasma AGP concentration were observed up to 6 weeks of age. 4. A single injection of 900 micrograms LPS per chick resulted in a 5-fold increase in AGP concentration compared with that in saline-injected chicks. Multiple injections of LPS (200 micrograms/chick every 2 d for 14 d) caused only a 50% increase in AGP concentration.

Aging↗
PubMed1994

MEGA: Molecular Evolutionary Genetics Analysis software for microcomputers.

A computer program package called MEGA has been developed for estimating evolutionary distances, reconstructing phylogenetic trees and computing basic statistical quantities from molecular data. It is written in C++ and is intended to be used on IBM and IBM-compatible personal computers. In this program, various methods for estimating evolutionary distances from nucleotide and amino acid sequence data, three different methods of phylogenetic inference (UPGMA, neighbor-joining and maximum parsimony) and two statistical tests of topological differences are included. For the maximum parsimony method, new algorithms of branch-and-bound and heuristic searches are implemented. In addition, MEGA computes statistical quantities such as nucleotide and amino acid frequencies, transition/transversion biases, codon frequencies (codon usage tables), and the number of variable sites in specified segments in nucleotide and amino acid sequences. Advanced on-screen sequence data and phylogenetic-tree editors facilitate publication-quality outputs with a wide range of printers. Integrated and interactive designs, on-line context-sensitive helps, and a text-file editor make MEGA easy to use.

Algorithms↗
PubMed1994

Etiology of diarrhea in a rural community in western Thailand: importance of enteric viruses and enterovirulent Escherichia coli.

The etiology of gastroenteritis was determined in children and adults with diarrhea seen at a district hospital and three government health clinics in Suan Phung, western Thailand, in 1991. Enteric viruses (rotavirus and astrovirus) were identified in 40%, shigellae in 18%, attaching and effacing Escherichia coli in 13%, Campylobacter jejuni in 9%, and enterotoxigenic E. coli in 7% of children < 5 years old with diarrhea seen at the hospital. Enteric viruses were detected in 15% (24/156) of patients with diarrhea > or = 5 years old and were the only enteric pathogens identified in 12 patients ages 7-79 years (2 astrovirus, 10 rotavirus infections). Attaching and effacing E. coli, rotavirus, and astrovirus were potential causes of diarrhea in children and adults in this population.

Adenoviruses, Human↗
PubMed1994

The role of human factor X activation peptide in activation of factor X by factor IXa.

We studied the interaction of factor X activation peptide (XAP) with factor IXa and factor Xa and the effect of XAP on factor IXa-catalyzed activation of factor X. XAP associated with factor Xa in the presence of 5 mM Ca2+ was dissociated from factor Xa by gel chromatography using Ultrogel AcA54 in 5 mM EDTA, or in 8 M urea-0.1% SDS. An exogenous isolated XAP inhibited the factor IXa-catalyzed factor X activation both in the presence and absence of factor VIIIa. 4-Amidinophenylmethylsulfonyl (aPMS)-factor Xa independent of XAP also inhibited the factor X activation more effectively than XAP alone in the presence of factor VIIIa. However, aPMS-factor Xa independent of XAP hardly inhibited the factor X activation in the absence of factor VIIIa. The binding of 125I-labeled factor X to the aPMS-factor IXa fixed to a microwell plate was inhibited by unlabeled factor X or XAP, but not by aPMS-factor Xa with or without XAP. Factor IXa directly bound to XAP and aPMS-factor Xa with XAP, but did not bind to aPMS-factor Xa without XAP. These findings suggest that the region of XAP in factor X directly interacts with factor IXa, and factor Xa region other than XAP interacts with factor VIIIa. Desialation or deletion of N-linked carbohydrates of XAP reduced the inhibitory activity of XAP for the factor X activation by factor IXa to approximately 50% of that of the intact XAP. This suggests that the sialic acids in the carbohydrate chains of the XAP region partly contribute to the interaction with factor IXa during its activation.

Amino Acid Sequence↗
PubMed1994

Residual left ventricular pump function following acute myocardial infarction in postmenopausal diabetic women.

BACKGROUND: The Framingham Study indicated that women with diabetes mellitus developed cardiac failure four times more often than those without diabetes mellitus after acute myocardial infarction. However, there is little information on residual left ventricular pump function after myocardial infarction in female diabetic patients. METHODS: To evaluate the difference between postmenopausal women and age-matched men in the impact of diabetes mellitus on left ventricular pump function during the first year after myocardial infarction, radionuclide angiography was performed during the third week after acute myocardial infarction and again 1 year later in 50 patients (21 women, 29 men) with diabetes mellitus and 62 patients (25 women, 37 men) without diabetes mellitus. RESULTS: Although the radionuclide angiographic indices did not change during the first year after myocardial infarction in non-diabetic patients, left ventricular end-diastolic volume increased, and the left ventricular ejection fraction, the regional ejection fraction of the non-infarcted area, and the ratio of arterial systolic blood pressure to left ventricular end-systolic volume (pressure:volume ratio) decreased in the diabetic patients. Furthermore, the degree of change in the left ventricular end-diastolic volume, the left ventricular ejection fraction, the regional ejection fraction of the non-infarcted area, and the pressure:volume ratio in diabetic women was larger than that in diabetic men. CONCLUSION: The increase in the left ventricular end-diastolic volume and the decrease in the regional ejection fraction of the non-infarcted area during the first year after myocardial infarction in postmenopausal women with diabetes mellitus indicate that female sex associated with diabetes mellitus may be important factors in left ventricular remodeling in postmenopausal women.

Aged↗
PubMed1994

Late potentials during left ventricular healing of acute myocardial infarction.

BACKGROUND: Late potentials and left ventricular remodeling are important factors in the prognosis of acute myocardial infarction. However, the relationship between late potentials and ventricular remodelling has not been fully evaluated. METHODS: We evaluated clinical characteristics, coronary angiographic findings and radionuclide angiographic measures about 1 month after an acute myocardial infarction in patients with and without late potentials. RESULTS: Although the left ventricular ejection fraction of patients with late potentials was not different from that of patients without late potentials, the left ventricular end-diastolic volume of patients with late potentials was larger than that of patients without late potentials (P < 0.05). There was a significant positive correlation between the left ventricular end-diastolic volume and the filtered QRS duration (r = 0.53, P < 0.001). The root mean square of the voltage in the terminal 40 ms and the low-amplitude signal duration of < 40 microV in the terminal QRS sequence were also correlated with the left ventricular end-diastolic volume (r = 0.40, P < 0.02, and r = 0.39, P < 0.02, respectively). Patency of the infarct-related vessel in the late phase of an acute myocardial infarction was an important factor associated with the occurrence of late potentials (P < 0.01). CONCLUSION: A larger left ventricular end-diastolic volume in patients with late potentials might be associated with left ventricular remodeling during the first month after an acute myocardial infarction.

Coronary Angiography↗
PubMed1994

The effect of platelet-activating-factor antagonist TCV-309 on arrhythmias and functional recovery during myocardial reperfusion.

BACKGROUND: We investigated the effects of a platelet-activating-factor antagonist TCV-309, an antagonist of metabolites of ischemia, on arrhythmias and functional recovery during in-situ reperfusion in dogs. METHODS: Open-chest anesthetized dogs were subjected to ligation of the left anterior coronary artery. Ischemia was maintained for 20 min after which reperfusion was allowed. A cardiac surface ECG was recorded continuously with the II limb lead. Monophasic action potential, left ventricular segment shortening measured by sonomicrometer, and left ventricular pressure were recorded simultaneously under atrial pacing (group A, n = 14). In a second group of dogs, TCV-309 (1 mg/kg) was administered before coronary artery occlusion (group B, n = 12). The hearts were constantly paced through the right atrium at 120 beats/min throughout all experiments. Measurements were continuously obtained from before drug administration to 30 min after reperfusion. RESULTS: The 90% repolarization time of monophasic action potentials in group B revealed significant recovery compared with group A until the fifth minute after reperfusion (P < 0.02). Reduction of severe ventricular arrhythmias was observed during reperfusion in group B (P < 0.05). The percentage segment shortening and left ventricular pressure did not differ significantly between the groups. CONCLUSION: The platelet-activating-factor antagonist had beneficial effects on arrhythmias but not on functional recovery during reperfusion after brief coronary artery occlusion in situ in dogs.

Action Potentials↗