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Biomedical subjects

N Kajiwara

Publications and source records attributed to N Kajiwara.

At least 19 recordsLinked to original sources
PubMed1998

Left ventricular geometric patterns and QT dispersion in borderline and mild hypertension: their evolution and regression.

To investigate whether QT dispersion increases in borderline and mild hypertension during a longitudinal observation of > 3 years and whether it is improved with medications, left ventricular geometric patterns and QT dispersion were studied with special regard to their longitudinal changes in 85 male borderline and mild hypertensive subjects with left ventricular mass index < 125 g/m2. These subjects were followed for > 3 years without medication. Thirty-two patients with a left ventricular mass index > 125 g/m2 at the end of follow-up period were further observed using antihypertensive drugs for an additional 3 years. Echocardiograms and electrocardiograms were obtained at the beginning and end of the follow-up period. At the end of the follow-up period, subjects were classified into four groups based on ventricular geometric patterns determined by left ventricular mass index and relative wall thickness in diastole. The QT dispersion was greater in patients with concentric hypertrophy (56+/-18 msec) than in patients with normal geometry (41+/-17 msec) (P < .05) and increased significantly in the former group during the follow-up period. After medication, the left ventricular mass index regressed and the QT dispersion decreased (from 55+/-21 to 50+/-26 msec, P < .01) in these patients. Thus, these findings suggest that changes in the QT dispersion reflect both concentric evolution and regression of left ventricular hypertrophy.

Adult↗
PubMed1997

The relationship of hyperinsulinemic state to left ventricular hypertrophy, microalbuminuria, and physical fitness in borderline and mild hypertension.

The relationship of the hyperinsulinemic state to left ventricular hypertrophy, left ventricular geometric patterns, microalbuminuria, and physical fitness were studied in 52 middle-aged unmedicated men with borderline and mild hypertension. Left ventricular mass index and relative wall thickness were assessed by echocardiography. Physical fitness was determined by symptom-limited maximal treadmill stress testings. The urinary concentration of microalbumin and C-peptide was measured in 24-h urine samples by radioimmunoassey. The 24-h urinary C-peptide excretion rate was correlated with left ventricular mass index (r = 0.46), relative wall thickness (r = 0.41), treadmill time (r = -0.35), normalized treadmill time (r = -0.52), systolic blood pressure at peak exercise (r = 0.29), and 24-h urinary microalbumin excretion (r = 0.48). Stepwise multiple regression analysis identified the left ventricular mass index, the 24-h urinary albumin excretion, and the normalized treadmill time as variables in the equation for the 24-h urinary C-peptide excretion. Thus, the hyperinsulinemic state is related to left ventricular hypertrophy, microalbuminuria, and impaired physical fitness in patients with borderline and mild hypertension.

Adult↗
PubMed1997

Effects of long-term antihypertensive therapy on physical fitness of men with mild hypertension.

This study was conducted to investigate the effects of long-term administration of a calcium-channel antagonist (nifedipine) and a beta-blocker (acebutolol) on physical fitness in men with mild hypertension. All subjects underwent symptom-limited treadmill stress testing and routine echocardiographic studies. Twenty-two subjects who had either a causal diastolic blood pressure of more than 105 mmHg or a left ventricular mass index (LVMI) of 125 g/m2 or more during follow-up were assigned to receive medical therapy. The other 31 men who did not meet either criterion were continuously followed-up without medication. Among the 22 treated men, the age-adjusted treadmill time (normalized treadmill time, TMTn) significantly decreased before the initiation of medication, while 31 untreated men showed no change in TMTn throughout the study. The 22 treated subjects were subsequently divided into two groups; 13 were given nifedipine and 9 were given acebutolol. All treated subjects were followed-up for more than 3 years. After treatment, the two groups showed similar reductions in blood pressure and LVMI, but a different outcome for TMTn: TMTn increased from 104 +/- 8% to 115 +/- 16% in subjects given nifedipine (p < 0.05) and decreased from 106 +/- 12% to 99 +/- 10% (p < 0.01) in those given acebutolol. Thus, the physical fitness of subjects who required medication significantly deteriorated without medication; their physical fitness improved after treatment with a calcium-channel antagonist and deteriorated after treatment with a beta-blocker.

Acebutolol↗
PubMed1996

Primary pulmonary lymphoma diagnosed by gene rearrangement: report of a case.

We report herein the case of a 59-year-old asymptomatic man who was referred to our department for investigation of an abnormal shadow detected on a routine chest roentogenogram. Computed tomography (CT) showed an infiltrative shadow and air bronchogram in the right middle lobe without mediastinal lymphadenopathy, and a right middle lobectomy was performed with hilar and interlobar lymph node excision. Microscopically, the tumor consisted of small lymphoid cells without atypia, admixed with neutrophils and other mononuclear cells, but there was no invasion of the bronchial cartilage or visceral pleura, or any lymph node involvement. Most of the tumor cells were positive for L26 and some for UCHL-1. Although a germinal center was not seen, pseudolymphoma could not be ruled out. Southern blot analysis of the frozen tissues revealed clonal rearrangements of the immunoglobulin heavy-chain JH and light-chain J kappa, whereby the tumor was diagnosed as malignant lymphoma of the small lymphocytic B-cell type. Thus, when such lymphoproliferative diseases which are difficult to diagnose are encountered, frozen tissue should be preserved for genetic analysis.

Blotting, Southern↗
PubMed1996

Evaluation of a new solution containing trehalose for twenty-hour canine lung preservation.

We examined the efficacy of two new preservation solutions containing trehalose--an extracellular type (ET-K) of solution and an intracellular type (IT-K) of solution--in relation to that of Euro-Collins (EC) solution in 20-h canine lung preservation. Canine lungs were flushed with one of the three solutions (n = 5 for each solution) after pretreatment with PGE1 (20 micrograms/kg) and were stored for 20 h at 4 degrees C. The left lungs were transplanted and evaluated to 6 h post transplant. In the ET-K group, the arterial oxygen tension after reperfusion was significantly higher than in the IT-K and EC groups. The pulmonary vascular resistance, wet/dry weight ratio, and histological evaluation of each transplanted lung in the ET-K group were also better than in the IT-K and EC groups. This indicates that ET-K solution is useful for 20-h preservation of canine lung grafts.

Analysis of Variance↗
PubMed1996

Prospective studies on left ventricular geometric patterns and exercise tolerance in unmedicated men with borderline and mild hypertension.

OBJECTIVE: This study was designed and conducted to assess the clinical significance of left ventricular geometric patterns and physical fitness in subjects with untreated borderline and mild hypertension. METHODS: Symptom-limited maximal treadmill stress testings and echocardiographic examinations were administered to 192 previously unmedicated men. Left ventricular geometric patterns were determined by the combined criteria of left ventricular mass index and relative wall thickness. Subjects whose left ventricular mass index was < 125 g/m2 were followed up for more than 3 years. RESULTS: Normalized treadmill time was lower and pressure rate products at peak exercise were higher in patients with concentric hypertrophy than in those with normal geometry. Of the 77 patients who revealed left ventricular mass index at baseline < 125 g/m2 and who were successfully followed without medication for more than 3 years, 18 demonstrated concentric hypertrophy at the final follow-up examination. During the follow-up period, these 18 patients had significant further augmentation of concentric geometric features, significant decreases in both cardiac output and normalized treadmill time, and significant increases in casual blood pressure and total peripheral resistance compared with those at baseline. CONCLUSION: Patients with concentric hypertrophy exhibited slightly but significantly impaired levels of physical fitness and cardiac work efficiency, and the progression of concentric hypertrophy demonstrated further impairments of these conditions. Therefore, not only lowering blood pressure, but also improving left ventricular hypertrophy, cardiovascular hemodynamics, and physical fitness might be required in patients with concentric hypertrophy.

Adult↗
PubMed1996

Vertical transmission to embryo and fetus in maternal infection with rat virus (RV).

The influence of maternal rat virus (RV) infection on rat embryogenesis and fetus was examined by viral reisolation, immunostaining and PCR analysis. Vertical transmission caused by the UT-1 strain of RV depended on the stage of gestation when maternal infection occurred. When females were infected at the pre-mating point, the number of fetuses was smaller than that normally obtained, possibly due to infection at the stage of the hatched blastocyst, but almost all of the fetuses obtained were free from infection and developed normally. The incidence of transplacental infection was the highest when pregnant females were infected in the middle of the gestation stage, and some of the fetuses died. In pregnant females which were infected late in the gestation stage, all fetuses developed normally. Some of them were infected transplacentally and harbored the infectious virus. Much attention should be paid to performing reliable rederivation of RV-infected rat colonies by hysterectomy and embryo transfer.

Animals↗
PubMed1995

Changes in the E/A ratio induced by handgrip-exercise are related to changes in the plasma atrial natriuretic peptide level, but not to changes in brain natriuretic peptide in mild essential hypertension.

We investigated the relationship between changes in atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) and changes in cardiac function during mild exercise in patients with mild hypertension. The handgrip test (HGT) was performed by 21 untreated, mildly hypertensive patients, mean age 45 +/- 5 years. M-mode and pulse Doppler echocardiograms were recorded before and during HGT. In 7 patients (Group A), diastolic function, which was determined by the peak early velocity and peak atrial velocity (E/A) ratio using Doppler echocardiography was attenuated during HGT (1.19 +/- 0.21 TO 1.04 +/- 0.16, p < 0.05). There was no change in diastolic function in the remaining 14 patients, left atrial diameter, cardiac index, ejection fraction, plasma renin activity, plasma norepinephrine, blood pressure, nor heart rate were different between the two groups. While ANP was increased in Group A during HGT (from 41.0 +/- 18.2 to 54.0 +/- 24.1 pg/ml, p < 0.05) it was unchanged in Group B (36.8 +/- 16.3 to 33.5 +/- 11.9 pg/ml). BNP did not change in either Group (Group A: 2.9 +/- 3.1 to 3.0 +/- 3.4 pg/ml, Group B: 2.6 +/- 1.6 to 3.6 +/- 4.8 pg/ml). The percent change in ANP during HGT did not correlate with the percent change in BNP. Thus, the impairment of cardiac functional reserve appeared to influence ANP excretion in patients with mild hypertension.

Adult↗
PubMed1995

[Staged bilateral upper lobectomy of pathologically different synchronous double primary cancer].

A case of double primary lung cancer was reported, one of which was peripheral type of adenocarcinoma of the right lung and the other was central type of squamous cell carcinoma of the left. A 66-year-old male was referred to our hospital on Nov. 2 1991, because a coin lesion at the right S1 was pointed out on chest X-ray. On bronchoscopy, a nodular tumor at the orifice of the left B3 was unexpectedly found. Biopsy of the left B3 tumor and washing cytology of the right B1 led to a diagnosis of left moderately differentiated squamous cell carcinoma (clinical T1N0 M0) and right adenocarcinoma (clinical T1N0M0). A right upper lobectomy was first performed with R2 lymph node dissection on Nov. 25 1991. Post-operatively, it was confirmed that the lesion was histologically poorly differentiated adenocarcinoma of the right S1, and the pathological stage was T2N0M0. Two weeks after the operation, chemotherapy of CDDP, VDS and MMC was given because of suspicion of rapid metastasis to the left hilar lymph nodes. Left upper lobectomy with R2 dissection was performed 7 weeks after the initial operation. Pathological findings showed squamous cell carcinoma originating from B3 with inflammatory lymphadenopathy and pathological evaluation was T1N0M0. He was discharged after an uneventful course of 3 weeks after the second operation. There are many reports that limited operations are recommended for each lesion in double primary lung cancer to reserve the pulmonary function. However, limited interventions cause frequently local metastasis, especially in peripheral type adenocarcinoma more than 3 cm in diameter and central type squamous cell carcinoma with lymph node metastasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1994

The efficacy of monatepil, a new calcium antagonist, in the treatment of essential hypertension.

A multicenter, open-label trial in Japan examined the efficacy, safety, and optimal dose of monatepil (AJ-2615) as monotherapy and in combination therapy with angiotensin-converting enzyme (ACE) inhibitors or beta-blockers. Patients with essential hypertension who had never been treated or had been refractory to conventional antihypertensive agents were enrolled in the trial. During a 4-week control period patients assigned to monotherapy received placebo and those assigned to combination therapy received an ACE inhibitor or beta-blocker and placebo. Patients with systolic blood pressure (BP) > or = 160 mm Hg and diastolic BP > or = 95 mm Hg at the end of the control period were enrolled in the study. The initial dose of monatepil was 30 mg/day in monotherapy and 15 mg/day in combination therapy; the daily dose was titrated to 60 mg/day according to the antihypertensive response. The treatment period was 8 to 12 weeks. Blood pressure decreased from 168 +/- 8/100 +/- 6 to 142 +/- 9/85 +/- 7 mm Hg (SD) with monatepil monotherapy, from 171 +/- 11/102 +/- 6 to 141 +/- 9/84 +/- 6 mm Hg in combination with ACE inhibitors, and from 175 +/- 13/102 +/- 7 to 153 +/- 21/91 +/- 9 mm Hg in combination with beta-blockers (P < .001). When patients in whom mean BP decreased by > or = 13 mm Hg were defined as responders, the response rate was 80.4%, 78.1%, and 51.6% in the respective groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1994

Comparison of manual and computer-assisted automatic measurements of wall thickness of the left ventricle in two-dimensional echocardiography.

To investigate the clinical applicability of automatic analysis of wall thickness in two-dimensional echocardiography, computer-assisted and conventional manual methods were compared in 26 cases. An echo threshold was automatically set in short-axis echo images through a discriminatory variance analysis of the signal-to-noise ratio. A fixed standard was determined inside the left ventricle using the circle window method, which we developed previously. Two abrupt echo reflections were selected as candidate points for the borders, and an outward search was conducted in all directions from a fixed standard to separately delineate the endocardial and epicardial interfaces. Interpolation using a spline function was applied to these points to complete the border lines. Differentiation was also used to eliminate the anterior and posterior papillary muscles. Significant correlations of r = 0.98 were found between the computer and manual assessments of the epicardial and endocardial intraluminal ventricular areas (p < 0.01). A correlation of r = 0.87 was also obtained for myocardial wall thickness as determined by the 2 methods (p < 0.01). Variability of the reproducibility using the computer method was 0.22% for the epicardial area and 0.64% for the endocardial area. These results confirm that computer-aided automatic measurement of wall thickness is clinically applicable to two-dimensional echocardiography.

Adult↗
PubMed1994

Thrombolytic therapy for acute myocardial infarction-effects, problems and strategies.

The effects and problems of coronary thrombolysis (CT) were investigated in 652 patients with initial acute myocardial infraction (AMI). Nosocomial mortality obtained by matching factors which determined prognosis was significantly lower in patients treated by CT (8.3%) than in those who did not undergo CT (18.1%). Regardless of whether the treatment was intracoronary arterial (ICT) or intravenous (IVCT), the primary cause of the decreased mortality was reperfusion of the coronary artery responsible for infarction (mortality 6.1% in the reperfused group vs 21.5% in the ineffective group). CT therapy improved left ventricular ejection fraction (LVEF), the nosocomial mortality rate, and regional wall motion at the site of infarction in cases that were reperfused less than 3 h, 3-6 h, and even 6 or more hours after the therapy. The long-term prognosis was significantly better in the reperfused group than in the ineffective group for 5 years and 7 months after therapy. However, CT was accompanied by both (1) poor prognosis in the ineffective group; and (2) unfavorable effects on the prognosis and on the daily life of patients with severe stenosis even after treatment. Accordingly, supplemental ICT and rescue PTCA (strategy (A)) were performed to treat the first problem, and deferred PTCA (strategy (B)) was conducted to treat the second problem in 80 patients with initial AMI. As a result, strategy (A) increased the coronary reperfusion rate to 94.3%, and strategies (A) and (B) together decreased the nosocomial mortality rate of 8.5% to 3.8%, and reduced the risk of death by 55.3%.

Humans↗
PubMed1993

Chimeric renin-angiotensin system demonstrates sustained increase in blood pressure of transgenic mice carrying both human renin and human angiotensinogen genes.

A reaction between enzyme renin and its only natural substrate angiotensinogen is the initial and rate-limiting step for producing a potent vasoconstrictor angiotensin II as the final product of the renin-angiotensin system, a contributory factor in the pathogenesis of hypertension. In order to assess the role of the interaction of human renin with human angiotensinogen in the development of high blood pressure, we have constructed the chimeric renin-angiotensin cascade in mice comprising both human renin and human angiotensinogen as well as the endogenous angiotensin-converting enzyme and angiotensin II receptor by cross-mating separate lines of transgenic mice carrying either the human renin or human angiotensinogen genes. Although each single gene carrier did not develop hypertension despite the observed normal tissue-specific expression of the transgenes, dual gene strains exhibited a chronically sustained increase in blood pressure. Administration of a human renin-specific inhibitor (ES-8891) was effective in reducing the elevated blood pressure only against the cross-mated hybrid mice, but treatment of an angiotensin-converting enzyme inhibitor (captopril) and a selective antagonist (DuP 753) directed at the angiotensin II receptor decreased the basal level of blood pressure even in single gene carriers as well as in dual gene mice. These results clearly demonstrated that the sustained increase in blood pressure of the hybrid mice was initiated by the interaction between the products of the two human genes.

Angiotensin I↗
PubMed1993

Nipradilol inhibits rat mesangial cell mitogenesis through the activation of soluble guanylate cyclase.

Nipradilol is a beta-adrenoreceptor blocking agent, whose structure contains an NO2 group. Thus, it is possible that it modulates the function of glomerular mesangial cells through the activation of soluble guanylate cyclase. To prove this hypothesis, we examined the effect of nipradilol on soluble guanylate cyclase, intracellular cyclic guanosine monophosphate (cGMP) accumulation, and the mitogenesis of cultured rat glomerular mesangial cells. Nipradilol increased intracellular cGMP accumulation in a dose-dependent manner through the activation of soluble guanylate cyclase. Furthermore, nipradilol inhibited the incorporation of [3H]thymidine into the mesangial cells stimulated by 2.5% fetal bovine serum in a dose-dependent manner. These results indicate that nipradilol may modulate mesangial cell function through an increase in intracellular cGMP resulting from the activation of soluble guanylate cyclase.

Adrenergic beta-Antagonists↗
PubMed1993

Differential modulation of mitogenic and metabolic actions of insulin-like growth factor I in rat glomerular mesangial cells in high glucose culture.

In order to explore the possible contribution of insulin-like growth factor I to the development of diabetic nephropathy, the effect of glucose on the mitogenic and metabolic actions of insulin-like growth factor I in cultured rat glomerular mesangial cells was examined. The stimulation of [3H]-thymidine incorporation by insulin-like growth factor I in the cells exposed to high concentrations (55 mmol/l) of glucose (4.6 +/- 1.3 fold stimulation) was significantly suppressed as compared with that in the cells cultured in 11 mmol/l glucose (17.5 +/- 0.8 fold). In contrast, [3H]-amino-isobutylic acid uptake into the mesangial cells was significantly enhanced by glucose (2.03 +/- 0.03 nmol.mg protein-1. 15 min-1 at 55 mmol/l glucose vs 0.59 +/- 0.01 at 11 mmol/l glucose), while 2-deoxyglucose uptake remained unchanged. [125I]-insulin-like growth factor I binding was slightly but significantly increased in the cells exposed to high concentrations of glucose. Thus, glucose may modulate the mitogenic and metabolic actions of insulin-like growth factor I differently in cultured mesangial cells probably at the post-insulin-like growth factor I receptor level. These results may indicate that the differential modulation of the actions of insulin-like growth factor I by glucose could result in the increase in amino acid uptake and decrease in the cell proliferation in the mesangial cells, possibly leading to enhanced mesangial matrix synthesis with a relatively small increase in mesangial cell volume as seen in diabetic nephropathy.

Aminoisobutyric Acids↗
PubMed1993

Neurotropism of mouse-adapted haemagglutinating encephalomyelitis virus.

The propagation of a mouse-adapted strain (67N) of haemagglutinating encephalomyelitis virus in infected mice and murine cells was examined by viral re-isolation and immunostaining. Viral propagation was strictly limited to the neurons and to an established line of neuroblastoma cells in in-vivo and in-vitro experiments. These results provide adequate evidence that this virus is neurotropic.

Animals↗