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Biomedical subjects

T Arima

Publications and source records attributed to T Arima.

At least 181 records · Page 10Linked to original sources
PubMed1993

Relationships between left ventricular mass, left ventricular work and coronary artery size in aortic regurgitation--possible mechanism of myocardial ischemia.

To investigate the relationships between coronary artery size, left ventricular (LV) mass, and LV stroke work in aortic regurgitation (AR), these values were measured in 19 patients with severe AR. Twenty normal subjects and 15 patients with mitral regurgitation (MR) were used as control groups. The coronary area index, i.e., the coronary cross-sectional area divided by body surface area (BSA), was larger in the AR group than in the control groups in all measured sites except for the peripheral left anterior descending coronary artery (LAD) and right coronary artery (RCA). However, the coronary area index divided by the LV mass was significantly smaller in AR and MR patients than in normal subjects. Furthermore, the coronary area index divided by LV stroke work was smaller in AR patients than in MR patients and normal subjects. These results suggest that the coronary blood flow associated with the increased LV mass and stroke work caused by regurgitation was insufficient in patients with severe AR, especially in the area of the LAD. Therefore, the occurrence of myocardial ischemia in patients with severe AR may involve inadequate enlargement of the coronary artery which perfuses the LV, in addition to factors such as decreased coronary perfusion pressure, increased coronary artery resistance and decreased coronary flow reserve.

Adult↗
PubMed1993

[HCV subtypes and their clinical significance].

We immunologically isolated a clone with a 177-bp DNA fragment, designated as #2-22, that had homology to the NS-5 region of a HCV genome. To classify this HCV isolate, we sequenced several clones (2028 bases in total) from a cDNA library constructed from a #2-22-positive patient's blood. They showed distinct similarity to the HC-J8 genome (type II b), among the known HCV subtypes. Using this #2-22 sequence for PCR, we screened the HCV-positive blood samples from Southern Kyushu, we could identify 27% of them as type II b. In another cDNA library, from a single blood donor, who did not have multiple infections of HCV, we found two clones that might have arisen from an ancestral (or previous or historical) intergenomic recombination. They had reversed orders of similarity to different HCV subtypes, that is, the first 149-bp clone had 94% identical bases with a segment of HC-J8 and 78% with the corresponding sequence of HC-J6, but the second 814-bp clone had 85% identical bases with a segment of HC-J8 and 94% to the corresponding sequence of HC-J6. The importance of subtype analysis is discussed in relation to its clinical application, such as diagnostics development.

Amino Acid Sequence↗
PubMed1993

[Laboratory diagnosis of left atrial thrombi in patients with mitral stenosis].

Left atrial (LA) thrombi sometimes occur in patients with mitral stenosis (MS) and may cause systemic embolization resulting in serious and fatal complications. Several clinical techniques are used to detect the presence of LA thrombi, but even echocardiography, the most widely used, has some drawbacks depending on the sizes and locations of the thrombi. This study evaluated D-dimer, fibrinopeptide A(FPA), and thrombin-antithrombin III complex (TAT) as molecular markers for diagnosing the presence of LA thrombi in 26 patients with MS who underwent cardiac surgery. Atrial fibrillation was detected in all patients. Patients with episodes of obvious thromboembolic diseases were excluded. Blood was obtained from the brachial vein before the surgery (3 +/- 1 days; mean +/- SD). The presence or absence of thrombi was confirmed at surgery in all patients. Levels of both D-dimer and TAT were significantly higher in patients with thrombi than in those without thrombi or in normal subjects. FPA levels did not differ significantly between the three groups. The levels of D-dimer and TAT correlated significantly with the weights of the LA thrombi. LA thrombi (ca > or = 2 g) were always confirmed at surgery in patients with levels of D-dimer higher than 200 ng/ml and/or levels of TAT higher than 4 ng/ml. These results indicate that D-dimer and TAT are simple and useful diagnostic markers for determining LA thrombi in patients with MS.

Antithrombin III↗
PubMed1993

Molecular cloning, sequencing and expression of core and NS3 fragments of HCV from patients with HCV infection.

Fragments of core and NS3 of hepatitis C virus-Hunan (HCV-Hun) were cloned by RT-PCR and gene recombinant techniques from blood samples collected in Hunan Province, China. In comparison with sequences of our samples with those of HCV-US and HCV-J, the homologies of nucleotides and amino acids were about 90%, indicating that fragments of core and NS3 of HCV-Hun were in a relative conserved region of HCV. Two fusion proteins containing the peptides coded by HCV core (MBP-HCV core) and HCV. NS3 (MBP-HCV. NS3-Gal) were expressed by Escherichia Coli with recombinant plasmids. The specific HCV antigenicity of the two fusion proteins were identified by western blotting. Therefore, MBP-HCV. core and MBP-HCV.NS3-Gal were found useful for anti-HCV assay.

Amino Acid Sequence↗
PubMed1993

[A case of refractory multiple myeloma effectively treated with long-term oral etoposide].

A sixty-two-year-old man was admitted to our hospital for diarrhea and fatigue on September 1, 1988. Laboratory examination revealed anemia and a high serum protein level with increased gamma-globulin. Although he had no apparent bony lesions, the bone marrow picture showing an increase of abnormal plasma cells and serum immunoelectrophoresis indicating the presence of monoclonal protein of IgG-gamma type were compatible with multiple myeloma, stage IIIA. None of the following combinations of interferon alpha and ranimustine, cyclophosphamide and prednisolone, or melphalan and prednisolone were effective in reducing the level of serum M-protein. Therefore, we started daily oral administration of etoposide (25 mg/day) on February 21, 1989. Then the serum M-protein level was gradually reduced, and partial remission was achieved after 9 months' administration. After 27 months treatment the regimen was changed from daily to every second day administration, and finally stopped after 40 months. The patient has been in remission without etoposide to date.

Administration, Oral↗
PubMed1993

[An experimental study on the correction of scoliotic deformity--an application of the short segmental fixation system].

The purpose of this experimental study is to seek a possibility if we could apply a short segmental fixation system for the correction of spinal deformity and keeping the moveability of the spine. We used 40 scoliotic rabbits in the experiment which were made after the Piggot's procedure. Apex of the curvature could be observed around T8 or T9. Ten of 40 rabbits were observed as a control group. On the other hand, the remaining 30 were used for an instrumentation group utilizing the short segmental fixation. Two complexes of T10-T11 and T12-L1 were made by mamillary process fixatives, bilateral small rods, wires and bone cement. The final magnitude of Cobb angle was 46.8 degrees on the average in the control group, and 14.8 degrees in the instrumentation group. In conclusion, short segmental fixation around the caudal area of the apex of the scoliotic curvature plays a major role in the correction of spinal deformity.

Animals↗
PubMed1993

[Macroscopic and histological studies on the gastric carcinoma having arisen from the cardiac gland mucosa--concerning to the esophageal invasion and the reliable surgical cut-line].

Cardiac carcinoma is defined as the carcinoma whose center of the mucosal lesion is located at the area of the stomach within 2.0cm from the esophago-gastric junction. Histological and macroscopical examination was performed concerning to the frequency of macroscopic type, the direction of the mucosal invasion, the tendency of the submucosal invasion and the esophageal invasion by using these cardiac carcinomas. The objects of this study are a hundred and thirty-nine cases of cardiac carcinomas. The conclusions are as follows: 1) Depressed type (Type II c) in early carcinoma, Type Borrmann 2 and Borrmann 3 in advanced carcinoma are the most frequent form of macroscopic types. 2) The majority (87.7%) of the early carcinomas was situated at the lesser curvature and the posterior wall of the cardiac mucosa (Figure 1). 3) The early cardiac carcinoma had a tendency to invade in the mucosal layer along the esophago-gastric junction (Table 2). 4) The cardiac carcinoma was thought to invade into the submucosa in its early phase, comparing to the carcinoma on the other area of the stomach (Table 3). Twenty-four out of thirty-five (68.6%) cases of cardiac carcinoma ranged from 11 to 20mm in diameter invaded into the submucosa (Table 3). 5) Twelve out of seventy-three (16.4%) of early cases and fifty-seven out of sixty-six (86.4%) of advanced cases showed the infiltration into the esophagus (Table 4, Figure 6). The reliable and surgical cut-line of the oral site can be established at the area over 11 mm in the distance from the oral margin of the mucosal invasion in the cases of early cardiac carcinoma, over 25mm in the cases of advanced differentiated type, and over 30mm in the cases of advanced undifferentiated type (Figure 6).

Cardia↗
PubMed1993

Response dynamics and directional properties of nonspiking local interneurons in the cockroach cercal system.

The response properties and directional receptive fields of nonspiking local interneurons in the cercal system of the cockroach are described. Wind-evoked responses were recorded intracellularly, and then analyzed by means of the Wiener kernel method in which a Gaussian white noise signal was used as a stimulus. Cross-correlation between the response and the white noise signal produced first- (linear) and second-order (nonlinear) kernels that were used to define input-output characteristics of the interneurons. Three sets of interneurons were distinguished on the basis of kernel analysis. First, responses in interneurons 101, 107, 111, and 203 were characterized predominantly by a differentiating first-order kernel, which suggests a linear relationship to the stimulus. The amplitude and waveform of the kernel changed with the change in stimulus angle, indicating that these four cells are directionally sensitive. Second, responses in interneurons 102 and 103 were also directionally sensitive but highly nonlinear. The first-order kernel was biphasic, whereas the second-order kernel had an elongated depolarizing peak on the diagonal. The response dynamics were accounted for by a cascade of two filters, a linear band-pass filter and a static nonlinear filter, in which the nonlinearity is a signal compression (or a rectification). Third, responses in interneurons 104 and 201 consist largely of the second-order nonlinear component. The second-order kernel, which had an elongated depolarizing peak or a hyperpolarizing valley on the diagonal, did not show any directional preference. The second-order nonlinearity was dynamic, and could be modeled by a band-pass linear filter-static nonlinearity-low-pass linear filter cascade, where the static nonlinearity is a full-wave rectification. The band-pass filter would simply reflect the mechanical property of cercal hair sensilla, whereas the low-pass filter represents the transfer at synapses between the cercal afferents and the interneurons. The nonlinear response thus explains the difference in the directional sensitivity while the differentiating first-order kernel explains the velocity sensitivity of the interneurons. We show that 101 and 107 respond most preferentially to wind from the left versus right, whereas 102, 103, 111, and 203 respond to wind from the front versus rear. Thus, it is suggested that there are two subsystems responding maximally to wind displacement along two coordinate directions, one for the longitudinal direction and the other for the transverse direction. On the other hand, the full-wave-rectifier nonlinear interneurons are omnidirectional, and thus suggested to code simply the power of the wind displacement.

Abdomen↗
PubMed1992

Chromosomal deletions and K-ras gene mutations in human endometrial carcinomas.

Forty-two endometrial carcinomas of various stages of progression were analyzed to search for loss of chromosomal regions and for point mutations of ras genes and amplification of Int-2 gene. This approach is particularly favorable for observation of genetic events and their significance in the process of neoplastic conversion by considering the clinico-pathological characteristics of each tumor. At least 3 genetic events, including 18q, 17p deletions, and point mutations at codon 12 of the K-ras gene, are implicated in the development of endometrial carcinomas. Likely targets for allelic losses on chromosomes 18q and 17p are the DCC gene and the p53 gene sequences, respectively. Overall numbers of allelic losses in individual tumors appeared to increase in case of advanced stage tumors, thereby indicating the association of allelic loss accumulation with tumor progression. The genetic features seen in 2 juvenile-type adenocarcinomas and 2 clear-cell carcinomas suggested the possibility that etiological factors providing selective pressure for particular mutation sub-sets during carcinogenesis are probably heterogeneous.

Adult↗
PubMed1992

Verapamil attenuates postischemic oxidative injury in the rat liver.

We assessed the effects of the calcium channel blocker verapamil on postischemic oxidative injury in the rat liver. In the untreated rats, the values of tissue lipid peroxidation products (thiobarbituric acid-reactive substances) remained unchanged during 90 min of warm ischemia. However, the values increased significantly after the next 60 min of reperfusion compared with those in the sham-operated rats (P less than 0.01). Intravenous infusion of verapamil (5 micrograms.kg-1.min-1) significantly reduced the extent of lipid peroxidation during reperfusion compared with that in the untreated rats (P less than 0.02). The percentages of tissue water content and the serum lactate dehydrogenase activities after 60 min of reperfusion were significantly lower in the treated rats than in the untreated rats (P less than 0.02 and P less than 0.01, respectively). We also investigated the influence of verapamil on superoxide-generating activity determined by the superoxide-dependent cytochrome c reduction of peritoneal polymorphonuclear leukocytes (PMNs) harvested from normal, non-ischemic, and non-treated rats in vitro. This demonstrated that there was no apparent effect with the highest verapamil concentration level (8 microM) observed in the rat plasma during our experiment. These findings suggest that verapamil might reduce the postischemic oxidative injury in the rat liver by mechanisms perhaps not related to the suppression of rat PMNs superoxide-generating activity.

Animals↗
PubMed1992

Hepatitis C: basic and clinical studies.

The HCV, a single stranded RNA virus belonging to the family of flavivirus, has been identified as the probable cause of the majority of cases of transfusion-associated NANB hepatitis and community-acquired NANB hepatitis in Japan. The hepatitis virus is present in a least 2% of the blood donor population and is extremely common in high risk groups, such as hemophiliacs and hemodialysis patients. The contribution of HCV infection to sporadic, acute and chronic hepatitis, liver cirrhosis and primary liver cancer has been established. Furthermore anti-HCV in 20% of alcoholic patients with liver injury suggest that HCV may be etiologically associated with liver disease previously attributed to other causes. Therapy of acute and chronic liver disease associated with HCV infection is likely to be undertaken with recombinant IFN alpha in the future to prevent the progression of the disease from acute hepatitis to chronic hepatitis, and from chronic hepatitis to liver cirrhosis or primary liver cancer. However the prevention of HCV infection will be the goal, in addition to screening of donor blood and exclusion to a large degree of positive units likely to decrease the incidence of post-transfusion hepatitis.

Amino Acid Sequence↗
PubMed1992

Fate of infants with neonatal hepatitis: pediatric surgeons' dilemma.

Thirty-five cases of neonatal hepatitis (20 males and 15 females) were reviewed, 3 of whom were lost during the follow-up, leaving 32 patients for review. There were 10 late deaths and 22 patients survived, 18 of whom with a normal bilirubin level and 4 with a bilirubin level of greater than 1.0 mg/dL. In the 18, jaundice disappeared between the ages of 4 and 7 months. The current lifestyles of the patients include 4 adults aged 19 to 21 who are either working or at university, while the other 18 children are all making good progress at school. Except for moderate growth retardation in 3 children, all are growing well. In all 10 patients who died, liver failure persisted until the time of death. Three died of other causes and 7 died of neonatal hepatitis itself between 4 months and 7 years of age. Four patients ran a fulminating course resulting in death between the ages of 4 and 12 months. All 7 had growth and developmental retardation. A histological examination showed that in those who died, there was significantly more periportal fibrosis, inflammation in the periportal area, and diffuse giant cell transformation. These results indicate that some infants with neonatal hepatitis have a poor prognosis and, therefore, the identification of such a condition requires a careful, long-term follow-up.

Adolescent↗
PubMed1992

Cerebral infarction in a heterozygote with variant antithrombin III.

BACKGROUND: We report a heterozygous case of familial qualitative deficiency of antithrombin III associated with cerebral infarction. CASE DESCRIPTION: A 33-year-old man had a history of recurrent transient ischemic attacks from the age of 28. Cerebral computed tomography at age 29 disclosed a low-density area in the left frontal lobe, and an internal carotid angiogram showed branch occlusion of the right anterior cerebral artery and stenosis of the left middle cerebral artery. Occlusion of the right middle cerebral artery developed thereafter. The plasma antithrombin III antigen concentration and progressive antithrombin activity were normal, but plasma heparin cofactor activity was low in the patient and his father. Nucleotide sequence analysis of the proband's deoxyribonucleic acid showed no mutation in exons II and VI of antithrombin III. CONCLUSIONS: We conclude that abnormal antithrombin III with defective heparin binding, even though heterozygous, may cause ischemic stroke in young adults. We named this antithrombin III variant "Antithrombin III Nagasaki."

Adult↗