Biomedical subjects

Kunio Hiwada

Publications and source records attributed to Kunio Hiwada.

27 records · Page 2Linked to original sources

PubMed2002

Circulating levels of insulin-like growth factor-1 and its binding proteins in patients with hypertrophic cardiomyopathy.

Insulin-like growth factor-1 (IGF-1) is important in the hypertrophic response of the myocardium, so the present study was designed to elucidate whether the circulating levels of IGF-1 and its binding proteins (IGFBPs) are related to the disease condition of patients with hypertrophic cardiomyopathy (HCM), in particular the occurrence of congestive heart failure (CHF). The study group comprised 124 patients with HCM and 15 healthy control subjects. The HCM patients were subdivided into 3 groups: 39 with hypertrophic obstructive cardiomyopathy (HOCM), 67 with hypertrophic non-obstructive cardiomyopathy (HNCM), and 18 with HCM and a history of CHF (HF-HCM, n=18). Serum levels of IGF-1 and IGFBPs (IGFBP-1 and -3) were compared between groups. IGF-1 levels were significantly higher in patients with HOCM and HNCM, and lower in patients with HF-HCM than in control subjects (p<0.0001, p<0.005, and p<0.05, respectively). IGFBP-1 levels were significantly higher in patients with HF-HCM than in the other 3 groups (p<0.0001 for all). The findings suggest that circulating levels of IGF-1 and IGFBP-1 are related to the extent of myocardial injury in patients with HCM.

Adult↗

PubMed2002

A case of metastatic extra-adrenal pheochromocytoma 12 years after surgery.

At the age of 53, a 65-year-old man had been diagnosed with extra-adrenal pheochromocytoma in the retroperitoneum and underwent total tumorectomy. Afterward, he had his serum catecholamine periodically measured in an outpatient clinic. In February 1999, 12 years after surgery, he complained of lower left abdominal pain. Computed tomography and magnetic resonance imaging revealed an osteolytic lesion in thoracic vertebrae 11Th (Th 11). Although his basal serum and urine catecholamines were at normal levels, glucagon injection increased blood pressure and plasma catecholamine levels. 131I-metaiodobenzylguanidine (MIBG) scintigraphy was specifically taken up to Th 11. By bone biopsy, the osteolytic lesion in Th 11 was finally diagnosed with metastasis of pheochromocytoma. For post-operative pheochromocytoma, long-term follow-up involving biochemical tests, including serum catecholamines, and MIBG is needed.

3-Iodobenzylguanidine↗

PubMed2002

Brain natriuretic peptide as a risk marker for incident hypertensive cardiovascular events.

We examined the effects of aging and hypertensive left ventricular hypertrophy on the plasma level of brain natriuretic peptide (BNP), and assessed BNP as a risk marker for incident hypertensive cardiovascular events. One hundred and eighty-five hypertensive patients were echocardiographically divided into a hypertensive group with normal left ventricular mass (n=96; age range, 37-86 years; left ventricular mass, 97+/-14 g/m2) and a hypertensive group with left ventricular hypertrophy (n=89; 37-90 years; 140+/-20 g/m2). Forty-four normotensive subjects served as the normotensive group (32-84 years; 91+/-15 g/m2). We examined the association of age with BNP in the three groups and also evaluated BNP as a risk marker for incident cardiovascular events by following up all patients for 40 months. All three groups demonstrated a significant positive relationship between age and BNP. The slope of the relation between age and BNP was steepest in the hypertensive group with left ventricular hypertrophy (p<0.0001 vs. the other two groups). Multiple regression analysis revealed that age, pulse pressure and left ventricular mass index were significantly associated with the increase in BNP. Multivariate Cox proportional hazards regression analysis, which was used to assess the potential association of age, pulse pressure, left ventricular mass index and BNP with the cardiovascular events during follow-up, revealed the highest correlation between BNP and incident cardiovascular events (risk ratio=1.011; p=0.0011). BNP, which is synergistically increased with aging and left ventricular hypertrophy, may be an important risk marker for hypertensive cardiovascular events.

Aged↗

PubMed2002

Questionnaire survey on the Japanese guidelines for treatment of hypertension in the elderly: 1999 revised version.

A questionnaire survey was administered to Japanese clinical specialists in hypertension in order to gauge their opinions on the 1999 revised version of the Guidelines for Hypertension in the Elderly prepared by the Comprehensive Research Project on Aging and Health of the Ministry of Health and Welfare. Out of 162 council members of the Japanese Society of Hypertension, 122 (75%) replied. The majority (93%) of respondents approved of the guidelines in general, and 72% of them approved of the age-related setting of a therapeutic goal for blood pressure. Sixty-five percent of respondents selected long-acting Ca antagonists, ACE inhibitors and low-dose diuretics as first-line agents for hypertension without complications in the elderly. The results of the questionnaire survey should be reflected in the next version of the guidelines.

Aged↗

PubMed2002

Occurrence of transient U-wave inversion during vasospastic anginal attack is not related to the direction of concurrent ST-segment shift.

STUDY OBJECTIVES: We sought to assess the incidence of transient U-wave inversion during vasospasm of the left anterior descending coronary artery (LAD) with ST-segment depression as opposed to that with ST-segment elevation. DESIGN: Retrospective study. SETTING: Cardiology division of acute-care hospitals. PATIENTS: We studied 49 patients with vasospastic angina whose vasospasm was induced in the LAD, not in the left circumflex coronary artery, by intracoronary injection of acetylcholine. MEASUREMENTS AND RESULTS: The ECG traces obtained during acetylcholine-induced vasospasm of the LAD were examined. Based on the direction of ST-segment shift, the patients were categorized into two groups: the ST-segment elevation group (n = 27) and the depression group (n = 22). There were no differences in age, gender, or cardiovascular risk factors between the two groups. The distribution of the spastic site in the LAD was also similar. A total reduction in luminal diameter during a provoked attack was more often observed in the ST-segment elevation group than in the ST-segment depression group (37% vs 9%, p = 0.02). Collateral circulation to the LAD was found in only one patient in each group. There were no differences between the two groups in heart rate, systolic BP, and double product of heart rate and systolic BP during the attack. The incidence of acetylcholine-induced anginal attack with U-wave inversion in the ST-segment depression group was nearly as high as that in the ST-segment elevation group (77% vs 78%, p > 0.99). CONCLUSIONS: The development of transient U-wave inversion during vasospasm of the LAD induced by intracoronary injection of acetylcholine does not depend on the magnitude of myocardial ischemia as judged by the direction of ST-segment shift.

Acetylcholine↗

PubMed2002

Relationship between cardiomyocyte cell death and cardiac function during hypertensive cardiac remodelling in Dahl rats.

The exact mechanisms responsible for the progression of heart failure remain unclear. We investigated the in vivo relationship between the incidence of apoptotic cell death and left ventricular function serially from the beginning of hypertension to decompensated heart failure in Dahl salt-sensitive rats. Dahl salt-resistant and Dahl salt-sensitive rats were fed on a high-salt diet from 6 weeks of age. Systolic blood pressure was recorded by the tail-cuff method every week. Cardiac function in vivo was evaluated by echocardiography and cardiac catheterization. Cardiomyocyte apoptosis was detected by the TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) method. The gene expression of Bax, Bcl-2 and Bcl-xL was analysed by Northern blotting. The TUNEL method revealed that the incidence of cardiomyocyte apoptosis was significantly increased in the hearts of 18-week-old Dahl salt-sensitive rats (apoptotic index 1.3 +/- 0.1%). Northern blot analysis revealed that the Bcl-xL mRNA level increased gradually during the progression towards heart failure. In conclusion, these data suggest that cardiomyocyte apoptosis is a terminal event, and plays a role as an aggravating factor in the vicious cycle of heart failure.

Analysis of Variance↗

PubMed2002

[A case of central diabetes insipidus caused by metastatic small cell lung cancer].

A 58-year-old man was admitted to our hospital because of cough, polydipsia and polyuria. Chest CT films showed mediastinal lymphadenopathy, nodules in the lung fields, and pleural effusion. Histopathologic examination of transbronchial biopsy specimens showed oat cell carcinoma. MRI films revealed tumorous swelling of the pituitary stalk. Central diabetes insipidus caused by pituitary metastasis of small cell lung cancer was diagnosed. After treatment with whole-brain irradiation and chemotherapy, the size of the swollen pituitary stalk was reduced and his urine volume decreased. He died of respiratory insufficiency 15 months after the initial diagnosis. No recurrence of pituitary metastasis was apparent. This was a rare case of central diabetes insipidus caused by pituitary metastasis of small cell lung cancer successfully treated with radiotherapy and chemotherapy.

Carcinoma, Small Cell↗

PubMed2001

A triad of serum response factor and the GATA and NK families governs the transcription of smooth and cardiac muscle genes.

Serum response factor and the (CC(A/T)(6)GG) (CArG) box interact to promote the transcription of c-fos and muscle genes; this tissue-specific activity may require co-regulators for serum response factor. The alpha(1) integrin promoter contains two cis-elements besides the CArG box: a TAAT sequence, a consensus binding site for homeoproteins, and a GATA-binding box. As a candidate TAAT-binding factor, we cloned an NK family homeobox gene, Nkx-3.2, which is expressed mainly in smooth muscle tissues and skeletal structures. Nkx-3.2, serum response factor, and GATA-6 were co-expressed only in the medial smooth muscle layer of arteries. These three transcription factors formed a complex with their corresponding cis-elements and cooperatively transactivated smooth muscle genes, including alpha(1) integrin, SM22alpha, and caldesmon. Cardiac muscle-specific members of the NK and GATA families exist, and the triad of Nkx-2.5, serum response factor, and GATA-4 also transactivated the cardiac atrial natriuretic factor gene, which contains a CArG-like box, a GATA-binding box, and an NK-binding element. Our findings demonstrate that smooth and cardiac muscle have a shared transcriptional machinery and that the GATA and NK families confer muscle specificity on the serum response factor/CArG interaction.

Amino Acid Sequence↗

PubMed1995

Beneficial Effect of a Long-Term Antihypertensive Therapy on Blood Pressure Response to Isometric Handgrip Exercise in Patients with Essential Hypertension.

To elucidate the effect of a long-term antihypertensive therapy on blood pressure (BP) response to isometric handgrip exercise (IHG) in patients with essential hypertension (EHT, n = 16), IHG was carried out at 30% maximal voluntary contraction of right hand for 3 min before therapy and after a long-term antihypertensive therapy. BP responsiveness to IHG was estimated by the difference between values obtained at rest and at 3 min during IHG (change of systolic BP = DeltaSBP, change of diastolic BP = DeltaDBP. Both DeltaSBP and DeltaDBP before therapy were markedly greater in EHT (DeltaSBP = 64 plus minus 18 mm Hg, DeltaDBP = 33 plus minus 9 mm Hg) than in age-mathced normotensive controls (NT, n = 8, 29 plus minus 4 mm Hg, 18 plus minus 4 mm Hg). By antihypertensive therapy, SBP and DBP in EHT were decreased from 152 plus minus 22 mm Hg to 136 plus minus 14 mm Hg and from 90 plus minus 18 mm Hg to 83 plus minus 10 mm Hg, respectively, but both SBP and DBP in EHT after antihypertensive therapy were still greater than those in NT. Both DeltaSBP and DeltaDBP in EHT after a long-term antihypertensive therapy were significantly smaller than those in EHT before therapy but were still significantly larger than those in NT. These results demonstrate that a long-term antihypertensive therapy reduces the exaggerated BP response to IHG in EHT.

Journal Article↗