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Biomedical subjects

K Ishikawa

Publications and source records attributed to K Ishikawa.

At least 163 records · Page 9Linked to original sources
PubMed2001

[Contrast agent improves diagnostic value of dobutamine stress echocardiography].

OBJECTIVES: Suboptimal endocardial definition reduces the diagnostic value of stress echocardiography for coronary artery disease, but intravenous infusion of a left ventricular contrast agent (Albunex) may enhance endocardial border delineation and improve the diagnostic value of dobutamine stress echocardiography. METHODS: Fifty-six patients, 38 with myocardial infarction, 16 with angina pectoris and two normal subjects, were enrolled in this study. Dobutamine was infused in scalar doses of 5 to 40 micrograms/kg/min. Intravenous infusion of Albunex (0.15 ml/kg) was administered at rest and during peak dobutamine stress during monitoring of the apical four-chamber view. The left ventricle in the apical four-chamber view was divided into six segments and an endocardial delineation score of 0 to 3 (none to excellent visualization) was given to each segment. RESULTS: Endocardial delineation score was increased after Albunex infusion from 2.0 to 2.3 in the basal-septal, 2.0 to 2.4 in the mid-septal, 1.1 to 1.8 in the apical-septal, 0.7 to 1.2 in the apical-lateral, 0.9 to 1.6 in the mid-lateral, and 1.2 to 1.9 in the basal-lateral segments during peak dobutamine administration. Endocardial border resolution in the lateral wall showed greater improvement than in the septal wall after Albunex infusion. Diagnostic values in the left anterior descending artery territory failed to improve with Albunex infusion (sensitivity 82% to 89%, specificity 94% to 89%, and accuracy 86% to 89%), whereas a higher diagnostic accuracy was noted in the left circumflex artery territory with Albunex compared to without Albunex (sensitivity 63% to 81%, specificity 88% to 98%, and accuracy 80% to 93%, p < 0.05). CONCLUSIONS: Contrast agent improves the diagnostic accuracy of dobutamine stress echocardiography in the left circumflex artery territory.

Aged↗
PubMed2001

[Development and evaluation of a QOL questionnaire for elderly subject living in a community].

A comprehensive, basic and simple QOL questionnaire for elderly subjects living in a community was developed, and its validity and reliability were examined. The subjects were 2944 individuals of 65 years or older living in 5 areas of metropolitan Tokyo and in a town of Aichi Prefecture. The QOL questionnaire with 19 questions was developed based on the component of QOL by Lawton and concept of QOL by Koyano. The questionnaire consisted of 6 subscales (daily activity, satisfaction with health, satisfaction with human support, satisfaction with economic state, symptom of depression and positive mental attitude). Factor analysis revealed that the 19 questions could be clearly separated into 6 components in Tokyo and Aichi districts with total variances of 70.8% and 78.4%, respectively. Scores of daily activity and positive mental attitude were significantly lower with older subjects in both men and women. However, scores for other subscales did not differ with age. Primary factors which are considered to affect QOL were compared with the 6 QOL subscales of this study. Being an outpatient had a significant relation to daily activity and satisfaction with health, presence of a spouse to satisfaction with human support, depressive state, positive mental attitude and possession of ones own room to satisfaction with economical state, and belief in religion to positive mental attitude. The results suggest that the present questionnaire include the basic components necessary for evaluation of QOL in elderly subjects living in a community. Further research is required to examine the validity of this questionnaire with correction of questions.

Aged↗
PubMed2001

[A case of benign schwannoma arising in the brachial plexus with intrathoracic extension].

A case of benign schwannoma originating from the lowest trunk of the left brachial plexus with intrathoracic extension was reported. Intrathoracic growth of a schwannoma of the brachial plexus has been reported in only five cases in the literature. The patient was a 35-year-old man and had been pointed out an abnormal shadow at the left lung apex on the roentgenogram since 20-year-old. The tumor shadow was increased to seven cm from four in size on recent chest X-ray. We performed a video-assisted thoracoscopic surgery with the oblique skin incision at the left neck and removed the tumor completely and safely.

Adult↗
PubMed2001

[Optimal lymph node dissection for colorectal cancer].

Previous studies on the distribution of positive lymph nodes have revealed that the colon should be resected 10 cm from the tumor on both sides and that the intermediate nodes along the main vessel should be dissected in patients with colon cancer. In rectal cancer, superior lymphatic spread along the inferior mesenteric artery (IMA) is the main metastatic route. The IMA should be dissected immediately after the bifurcation of the left colic artery, and the intermediate lymph nodes should be removed. The positive rate of the lateral lymph nodes is about 10%. The rate of local failure is high and the prognosis is poor in patients with positive lateral lymph nodes, even if the lateral lymph nodes have been dissected. However, it has been reported that lateral lymph node dissection combined with excision of the internal iliac vessels results in good disease-free survival in patients with positive lateral nodes. Therefore the indications for lateral node dissection remain controversial. Lymphatic spread into the mesorectum on the anal side has been shown to be an important factor in local failure. The mesorectum should be resected for up to 4 or 5 cm from the inferior tumor margin in middle rectal cancer, and the entire mesorectum should be removed in lower rectal cancer. Nerve tissue preserved in pelvic autonomic nerve-preserving surgery contains a small amount of lymphoid tissue and lymph nodes. Therefore the extent of lymph node dissection and the area of autonomic nerves to be preserved based on tumor site or tumor penetration remain controversial.

Colonic Neoplasms↗
PubMed2001

Relationship between morbidity and body mass index of mariners in the Japan Maritime Self-Defense Force Fleet Escort Force.

To establish a practical weight management program for mariners in the Japan Maritime Self-Defense Force (JMSDF) Fleet Escort Force, the relationship between morbidity and body mass index (BMI) was studied. To estimate morbidity, 10 medical problems were used as indices (hyperlipidemia, hyperuricemia, diabetes mellitus, lung disease, heart disease, upper gastrointestinal tract disease, hypertension, renal disease, liver disease, and anemia). A curvilinear relationship was found between morbidity and BMI, in which a BMI of 17.5 was associated with the lowest morbidity. This curvilinear pattern was more complex than a curve reported previously for Japanese civilians. Using the present curve and aiming for a BMI of 17.5 will help in the design and implementation of a practical management program for health promotion in the JMSDF.

Adipose Tissue↗
PubMed2001

[Complications of stress echocardiography].

BACKGROUND: Stress echocardiography is an established clinical testing method and is accurate for the detection of coronary artery disease. Despite its widespread use, the safety of stress echocardiography has not been sufficiently documented in Japanese laboratories. OBJECTIVES: The feasibility, safety, complications and side effects of stress echocardiography were assessed for detecting myocardial ischemia in patients with suspected coronary artery disease. METHODS: 1,866 patients who underwent dobutamine echocardiography(n = 897), exercise echocardiography(n = 722), and dipyridamole echocardiography(n = 247) were prospectively studied from November 1990 to April 2000. Dobutamine was administered intravenously at 5, 10, 20, 30, 40 micrograms/kg/min in 3-minute intervals. Exercise echocardiography used the supine ergometer, starting at 50 W and increasing gradually by 25 W at 3-minute intervals to the maximum of 150 W. Dipyridamole was administered intravenously at 0.14 mg/kg/min for 4 min. After a 4-minute observation period, the drug was re-administered at the same dose for 2 min. RESULTS: The most common side effects under each stress were ventricular premature beats in 34.1% (dobutamine echocardiography), ventricular premature beats in 14.4%(exercise), and headache in 24.3% (dipyridamole). Serious side effects occurred in one patient(0.05%). The case of acute myocardial infarction was caused by dipyridamole echocardiography, and the patient needed emergency coronary angioplasty. Seven patients needed other drug therapy for nonsustained ventricular tachycardia(one), paroxysmal supraventricular tachycardia(two), sinus bradycardia(three), and bronchial asthma(one). There was no incidence of death, shock, or ventricular fibrillation, sustained ventricular tachycardia or other conditions requiring inpatient observation during stress echocardiography. CONCLUSIONS: Stress echocardiography is a reasonable, safe method for determining myocardial ischemia, but may be associated with minor, self-limiting side effects.

Aged↗
PubMed2001

Molecular analysis of Salmonella Enteritidis isolates resistance to ampicillin and streptomycin from three outbreaks of food poisoning in Shiga prefecture.

In 1998 and 1999, there were three outbreaks caused by Salmonella Enteritidis in Shiga Prefecture. One outbreak was suspected to be a diffuse outbreak, caused by frozen cream puffs that had been sold in chain stores throughout Shiga Prefecture between the beginning of September and the beginning of October, 1998. The other outbreaks occurred in May and in August, 1999. All isolates of the three outbreaks showed an identical lysis pattern against the typing phage, though this pattern did not conform to the current scheme, so-called RDNC. In addition all isolates were resistant to ampicillin and streptomycin. However, the patterns of pulsed-field gel electrophoresis strongly indicated that the three outbreaks were actually independent.

Ampicillin↗
PubMed2001

A case of duodenal involvement of multiple myeloma imaged by positron emission tomography with 18F-fluorodeoxyglucose.

A 61-year-old woman had been treated for multiple myeloma for 4 years when she developed abdominal pain. Ultrasonography and computed tomography revealed a tumor in the abdomen. Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) showed increased FDG uptake in the tumor. In previous bone marrow lesions, which were in clinical remission after chemotherapy and radiotherapy, abnormal FDG uptake was not recognized. Pathological examination after surgery revealed the tumor to be a plasmacytoma of the duodenum. Plasmacytoma of the duodenum is rare but can be seen during the clinical course of multiple myeloma. A few reports have described FDG PET findings of plasmacytoma. Those previous reports and our present case suggest a potential value of FDG PET in the evaluation of multiple myeloma.

Duodenal Neoplasms↗
PubMed2001

[Autosomal dominant cortical cerebellar atrophy (ADCCA) linked to chromosome 16q].

Clinical features of and genetic approach identifying the gene for autosomal dominant cortical cerebellar atrophy linked to chromosome 16q (16q-ADCCA) are presented. The clinical characteristics of our 6 families with 16q-ADCCA were slowly progressive pure cerebellar syndrome with late age of onset (average +/- SD years: 55.9 +/- 10.0), which contrasts with more earlier onset, prominent sensory neuropathy and pyramidal tract signs seen in spinocerebellar ataxia type 4 (SCA4) linked to the same chromosomal region. To identify the gene responsible for 16q-ADCCA, we refined the previously mapped region and found that all of our 6 families share haplotype for markers lying in about 3-cM region in 16q31-q22, indicating that the founder effect is present in this disease. We next constructed a BAC contig spanning this 3-cM region. The maximum size of this contig was estimated 5 megabase (Mb). By searching public genome databases, we first examined for the presence for expansion of tandem repeat sequences in our patients. We found more than 50 tandem repeats including 8 CAG repeats. However, we have not detected any expansion in our patients so far. We are currently examining remaining repeat sequences for expansion and also several genes that appear potential candidates from their expression and functional profiles.

Cerebellar Ataxia↗
PubMed2001

[Spinocerebellar ataxia type 6].

Spinocerebellar ataxia type 6 (SCA6) is an autosomal dominant cerebellar ataxia caused by a CAG repeat expansion in the human alpha1A-calcium channel gene. In this section, recent advances regarding pathogenic mechanism underlying in SCA6 is presented. When human alpha1A-calcium channel gene with expanded CAG repeat is transfected into HEK cells, the voltage dependence of inactivation shifting negatively 6 to 11 mV was observed, indicating that calcium influx across plasma membrane is reduced. When alpha1A-calcium channel protein and polyglutamine stretch are examined in SCA6 brain by immunohistochemistry, formations of aggregations within the cytoplasm of SCA6 Purkinje cells were seen. These findings may indicate that both alteration of calcium channel function and formation of protein aggregation are involved in the pathogenic mechanism of SCA6.

English Abstract↗
PubMed2000

Usefulness of QT dispersion immediately after exercise as an indicator of coronary stenosis independent of gender or exercise-induced ST-segment depression.

Several recent studies suggest that QT dispersion on a standard 12-lead electrocardiogram is a clinically useful indicator of significant coronary stenosis. In this study, we compared the diagnostic accuracy of QT dispersion immediately after exercise as an indicator of coronary stenosis in men and women, and in the presence or absence of exercise-induced significant ST-segment depression. The subjects were 273 consecutive patients (mean age 56 +/- 9 years; 190 men and 83 women) without a history of myocardial infarction who underwent treadmill exercise electrocardiography and coronary angiography for evaluation of angina. Of these, 146 patients had no significant coronary stenosis, 61 had single-vessel disease, 56 had multivessel disease, and 10 had left main coronary artery disease. QT dispersion immediately after exercise was significantly greater in patients with significant coronary stenosis than in those without (64 +/- 14 vs 39 +/- 14 ms, p <0.01). QT dispersion immediately after exercise was significantly more sensitive in men (sensitivity 75%; specificity 85%) and significantly more specific in women (sensitivity 77%, specificity 88%) than exercise-induced significant ST-segment depression (men: sensitivity 62%, specificity 74%; women: sensitivity 81%, specificity 68%) as an indicator of significant coronary stenosis. The addition of factors such as gender and the presence or absence of exercise-induced significant ST-segment depression did not significantly alter the sensitivity and specificity of QT dispersion immediately after exercise for detecting significant coronary stenosis (patients with significant ST-segment depression: sensitivity 77%, specificity 88%; patients without significant ST-segment depression: sensitivity 72%, specificity 86%). In conclusion, QT dispersion immediately after exercise is a clinically useful indicator of significant coronary stenosis independent of gender or the presence or absence of exercise-induced significant ST-segment depression.

Angina Pectoris↗
PubMed2000

Neuronal expression of the fukutin gene.

Fukuyama-type congenital muscular dystrophy (FCMD), a relatively common autosomal recessive disorder in Japan, is characterized by severe congenital muscular dystrophy in combination with cortical dysgenesis (polymicrogyria). The gene responsible for FCMD encodes a novel protein, fukutin, which is likely to be an extracellular protein. Pathological study of brain tissue from FCMD fetuses revealed frequent breaks in the glia limitans and basement membrane complex. Disruption of the basal lamina in FCMD muscle was also seen. Thus, structural alteration of the basal lamina appears to play a key role in the pathophysiology of FCMD. To investigate the role of fukutin in brain anomalies, we examined fukutin mRNA expression in the human brain. Northern blot and RT-PCR analysis revealed that the fukutin gene is expressed at similar levels in fetal and adult brain, whereas its expression is much reduced in FCMD brains. Tissue in situ hybridization analysis revealed fukutin mRNA expression in the migrating neurons, including Cajar-Retzius cells and adult cortical neurons, as well as in hippocampal pyramidal cells and cerebellar Purkinje cells. However, we observed no expression in the glia limitans, the subpial astrocytes (which contribute to basement membrane formation) or other glial cells. In the FCMD brain, neurons in regions with no dysplasia showed fair expression, whereas transcripts were nearly undetectable in the overmigrated dysplastic region. These observations suggest that fukutin function may influence neuronal migration itself rather than formation of the basement membrane. Furthermore, differences in mRNA levels among neurons in early developmental stages may partially differentiate normal and abnormal regions.

Adult↗
PubMed2000

Nine polymorphisms of angiotensinogen gene in the susceptibility to essential hypertension.

Even if the importance of angiotensinogen (AGT) gene has been known in gene targeting animals and humans genetic studies, its precise mechanism and the interaction among AGT gene variants, plasma AGT concentration and risk for hypertension remain uncertain. We examined whether AGT gene variants predispose to hypertension via an increase of plasma AGT concentration. Plasma AGT concentration was estimated from plasma angiotensin I which was cleaved by an excess amount of human renin and measured by RIA. Using 9 AGT gene variants which included new polymorphisms (G-152A and T+31C), we examined the association with hypertension and with plasma concentration by a case-control study. Haplotype analysis revealed that G-6A, T+31C and M235T polymorphisms were in absolute linkage disequilibrium and were associated with hypertension but not with plasma AGT level. On the other hand, -1074t;T235 haplotype was associated with an increase of AGT level but not with hypertension. In the haplotype analysis, only H3 haplotype frequency, which contained G-6, T+31 and M235 alleles, was significantly increased in normotensive subjects, suggesting that this haplotype is associated with a hypotensive effect. According to combined haplotype analysis of diallele and microsatellite markers, it remains a possibility that M235T, T+31C, G-6A, A-20C and G-1074T polymorphisms may play an important role in increased risk for essential hypertension. Our results suggest that the positive association between AGT polymorphism and hypertension is not simply explained by an increase of plasma AGT concentration.

Alleles↗
PubMed2000

Crystal structure of red sea bream transglutaminase.

The crystal structure of the tissue-type transglutaminase from red sea bream liver (fish-derived transglutaminase, FTG) has been determined at 2.5-A resolution using the molecular replacement method, based on the crystal structure of human blood coagulation factor XIII, which is a transglutaminase zymogen. The model contains 666 residues of a total of 695 residues, 382 water molecules, and 1 sulfate ion. FTG consists of four domains, and its overall and active site structures are similar to those of human factor XIII. However, significant structural differences are observed in both the acyl donor and acyl acceptor binding sites, which account for the difference in substrate preferences. The active site of the enzyme is inaccessible to the solvent, because the catalytic Cys-272 hydrogen-bonds to Tyr-515, which is thought to be displaced upon acyl donor binding to FTG. It is postulated that the binding of an inappropriate substrate to FTG would lead to inactivation of the enzyme because of the formation of a new disulfide bridge between Cys-272 and the adjacent Cys-333 immediately after the displacement of Tyr-515. Considering the mutational studies previously reported on the tissue-type transglutaminases, we propose that Cys-333 and Tyr-515 are important in strictly controlling the enzymatic activity of FTG.

Amino Acid Sequence↗
PubMed2000

Combined therapy with conservative surgery, radiotherapy, and regional chemotherapy for maxillary sinus carcinoma.

BACKGROUND: Current goals for the treatment of carcinoma of the maxillary sinus include the preservation of vision, ability to eat, ability to communicate, and appearance as well as cure. METHODS: Seventy-five Japanese patients who presented with maxillary sinus carcinoma between 1979 and 1997 were analyzed retrospectively. There were 48 males and 27 females with a median age of 62 years. The mean follow-up period was 73 months. All patients underwent multimodality therapy including surgery through a sublabial incision, radiotherapy, and regional chemotherapy. The regional lymph nodes were treated only in those patients with cervical lymph node involvement. RESULTS: The 5-year and 10-year overall survival rates were 76% and 66%, respectively. In 65 patients with squamous cell carcinoma, the 5-year and 10-year overall survival rates were 77% and 66%, respectively. All 23 patients with orbital involvement retained the orbital contents and 17 patients demonstrated adequate ocular function. There was no disease recurrence reported among patients with involvement of the foramen rotundum or the foramen ovale, whereas two of the three patients with invasion of the foramen lacerum developed disease recurrence. There were 12 complications in 12 patients, including double vision (4 patients), cataracts (3 patients), trismus (4 patients), and fistula formation (1 patient). CONCLUSIONS: Control of the primary tumor site is important in the curative treatment of patients with maxillary sinus carcinoma. Combined therapy with conservative surgery, radiotherapy, and regional chemotherapy appears to be an effective method for local control and the preservation of ocular function.

Antimetabolites, Antineoplastic↗
PubMed2000

Origin of anomalous lattice expansion in oxide nanoparticles

Anomalous lattice expansions have been measured for the first time in monodisperse CeO2-x nanoparticles and in BaTiO3 single nanoparticles by electron diffraction. X-ray photoelectron spectroscopy studies on CeO2-x nanoparticles and ab initio computer simulation on BaTiO3 clusters show that the origin of expansion is the decrease of electrostatic force caused by valence reduction of Ce ions and the increase in ionicity of Ti ions, respectively. The lattice constant change of oxide (ionic) nanoparticles with the increase in ionicity would depend on the structure of the particles. Hence, first-principles calculations of large ionic clusters are indispensable.

Journal Article↗
PubMed2000

Induced antiferroelectric smectic- C(*)(A) phase by doping ferroelectric- C* phase with bent-shaped molecules

Doping of the ferroelectric Sm-C(*) phase with bent-shaped molecules induces the antiferroelectric Sm-C(*)(A) phase. The effect was observed by means of electro-optic and dielectric measurements in systems with weak interlayer interactions in which the relative strength of anticlinic-synclinic order between molecules in adjacent layers is easily controlled by external factors. Fourier-transform infrared spectroscopy studies suggest that the bent-shaped molecules are not flat. They reorient upon the electric field-induced antiferroelectric-ferroelectric transition to adopt a position in which the average direction of the carbonyl groups is in the smectic plane and a bending tip along the C2 symmetry axis.

Journal Article↗