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Biomedical subjects

H Itoh

Publications and source records attributed to H Itoh.

At least 649 records · Page 36Linked to original sources
PubMed1996

[Relationship between ischemic ST depression and oxygen uptake kinetics during ramp exercise test in patients with effort angina].

The relationship between ischemic ST depression and oxygen uptake kinetics was examined during cardiopulmonary exercise test using the ramp protocol in 22 patients (17 males and 5 females, mean age 61.4 +/- 8.1 years) with ischemic ST change (horizontal or down sloping ST depression over 1 mm) during a previous multi-stage exercise test (Bruce method). Patients were classified into three groups according to coronary angiographic findings: absence of significant stenosis group (control, n = 7), single-vessel disease group (n = 7) and multivessel disease (MVD) group (n = 8). Peak exercise time, peak heart rate, peak systolic blood pressure, anaerobic threshold, peak oxygen uptake (peak Vo2), exercise time, heart rate, systolic blood pressure, and oxygen uptake at appearance of ischemic ST change were measured. The ratio of oxygen uptake increase at appearance of ischemic ST change was calculated. Peak Vo2 was lower in the MVD group than in the control group (20.9 +/- 6.2 vs 27.3 +/- 3.3 ml/min/kg, p < 0.05), and exercise time from the beginning of ramp exercise to the appearance of ischemic ST depression was shorter in the MVD group than in the control group (5.2 +/- 2.1 vs 8.2 +/- 1.9 ml/min/kg, p < 0.05). The ratio of oxygen uptake increase was smaller in the MVD group than in the control group (0.7 +/- 0.3 vs 1.2 +/- 0.2, p < 0.01). These results could be caused by impaired increase of cardiac output due to myocardial ischemia occurring during exercise. In the clinical setting, these phenomena could be used as a parameter for differentiating ischemic from non-ischemic ST depression or evaluating the sensitivity of ischemic heart disease.

Aged↗
PubMed1996

Endothelial constitutive nitric oxide synthase protein and mRNA increased in rabbit atherosclerotic aorta despite impaired endothelium-dependent vascular relaxation.

Atherosclerotic arteries are well known to exhibit impaired endothelium-dependent relaxation (EDR), but the exact mechanism of this impairment remains unclear. Recently, endothelial constitutive nitric oxide synthase (ECNOS), which generates nitric oxide and mediates EDR, was cloned, and ECNOS mRNA expression was reported to be modified by various cytokines, lipoproteins, and shear stress. To investigate the expression of ECNOS mRNA and protein in atherosclerotic arteries with impaired EDR, thoracic aortas isolated from Watanabe heritable hyperlipidemic (WHHL) rabbits were examined by using in situ hybridization and immunohistochemistry. Compared with thoracic aortas from Japanese White rabbits, WHHL aortas exhibited significantly impaired EDRs, although both in situ hybridization and immunohistochemistry exhibited enhanced expression of ECNOS mRNA and protein in WHHL aortas. There was no significant relationship between expression of ECNOS mRNA and protein of endothelial cells and age of the examined WHHL aortas. These data suggest that the mechanism of impaired EDR in atherosclerotic arteries is not due to the decrease in ECNOS mRNA and protein.

Acetylcholine↗
PubMed1996

Immunocytochemistry of perinatal rat livers with a special reference to the roles of mesenchymal cells in hepatic differentiation.

To investigate the roles of extracellular matrix produced by hepatic mesenchymal cells in the organization of hepatic cell cords, perinatal rat livers were examined with immunocytochemistry of fibronectin (FN) and laminin (LM). Some hepatocytes in a free state at prenatal day 15 actively produced FN and LM in the rough endoplasmic reticulum but lost this synthetic activity when such cells were incorporated into hepatic cell cords. On the other hand, hepatic mesenchymal cells, especially those associated with the perisinusoidal space, retained this synthetic activity throughout the stages examined. In the differentiating hepatic cell cords, positive immunoreactions for FN and LM were preferentially seen on the cell surface facing both sinusoidal space and differentiating bile canaliculus concomitant with the expression of the tight junction protein, ZO-1, from prenatal day 17. Since such hepatocytes have lost or reduced their synthetic activities of both glycoproteins in the rER, the immunoreactions appear to be mainly due to hepatic mesenchymal cells which seem to play a role in the formation of the hepatic cell cords and the bile canaliculi.

Animals↗
PubMed1996

Macrophages and neutrophils infiltrating into the liver are responsible for tissue factor expression in a rabbit model of acute obstructive cholangitis.

Acute obstructive cholangitis (AOC) is one of the most fatal outcomes in sepsis, and frequently complicates disseminated intravascular coagulation (DIC). Recently we found that the plasma tissue factor (TF) level increased and changed in parallel with plasma markers of DIC in patients with AOC. To elucidate the role of TF in the pathogenesis of coagulopathy in AOC, we investigated the plasma levels of TF and its localization by immunohistochemical staining in rabbit models of AOC. Plasma TF activity significantly increased 3 h after the insult (0.63 +/- 0.1¿9 U/ml; p < 0.01) compared with that beforehand (0.05 +/- 0.02 U/ml), then reached a maximum level at 6 h (0.94 +/- 0.16 U/ml). The fluctuations in plasma TF activity correlated with those of the coagulation parameters including platelet count, fibrinogen, prothrombin time, and antithrombin III activity. Immunohistochemically, enhanced expression of TF was mainly detected in macrophages and neutrophils that had infiltrated into the liver sinusoids and around the bile duct, but not in the sinusoidal endothelial cells. A double immunofluorescence study revealed the concomitant presence of TF and fibrin at sites where macrophages and neutrophils had conglomerated. However, we could not detect an apparent change in TF expression in the lung or kidney. These data suggest that macrophages and neutrophils infiltrating into the liver sinusoids and around the bile duct play a pivotal role in TF expression, leading to coagulopathy in the acute phase of obstructive cholangitis in rabbits.

Acute Disease↗
PubMed1996

C-type natriuretic peptide in chronic renal failure and its action in humans.

We have previously reported that C-type natriuretic peptide (CNP), the third member of the natriuretic peptide family, is produced in vascular endothelial cells and acts as an endothelium-derived relaxing peptide. To clarify the clinical significance of CNP in renal disorders, we examined the plasma level of CNP in patients with various cardiovascular diseases, including chronic renal failure (CRF) patients who were under hemodialysis therapy. We also investigated biological effects of intravenously-administered CNP (0.43 nmol/kg) by bolus injection from the peripheral vein in healthy volunteers and measured systemic hemodynamic variables, plasma levels of CNP, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), cGMP, aldosterone and also urine volume, urinary excretions of sodium, potassium, chloride and cGMP. The plasma CNP levels in healthy humans (N = 13) was 1.4 +/- 0.6 fmol/ml. In CRF patients, the plasma CNP significantly increased up to 3.0 +/- 1.1 fmol/ml. The administration of CNP elicited significant increase of plasma cGMP level (from 4.77 +/- 1.25 to 8.33 +/- 1.59 pmol/ml 15 min after the administration) and of urinary cGMP excretion (from 30.7 +/- 4.3 to 74.9 +/- 13.4 nmol/30 min). Intravenously-administered CNP exerted significant diuretic (% increase: +117 +/- 85.0), natriuretic, kalliuretic and chloriuretic actions with the increase of endogenous creatinine clearance. CNP also elicited significant hypotensive actions (delta BPs/delta BPd: -4.3 +/- 1.3/-4.1 +/- 1.0 mm Hg) with the concomitant increase of heart rate (+7.6 +/- 2.6 bpm). Plasma aldosterone concentration significantly decreased from 45.4 +/- 2.3 to 35.4 +/- 4.9 pg/ml 30 minutes after the administration. Taken together, these results suggest a role for CNP in human renal function.

Adult↗
PubMed1996

[Significance of systemic inflammatory response syndrome at cardiopulmonary bypass].

Systemic Inflammatory Response Syndrome (SIRS) is a new concept of entry criteria for sepsis. This concept, when applied to area of Multiple Organ Failure (MOF), is considered to be a preparatory state for MOF. To study the significance of SIRS state at cardiac surgery, we measured the body temperature, white blood cell count, respiratory rate and heart rate of 18 patients who underwent elective cardiac surgery, from the 1st post-operative day to the 7th post-operative day. We also measured Interleukin-6 and 8 (IL-6 and IL-8) to understand the relationship between the SIRS state and inflammatory cytokines just after cardiopulmonary bypass (CPB), at the 1st, 3rd and 6th postoperative day. The result was as follows: Patients with CPB more than 120 minutes have more frequency and longer duration of SIRS than patients with CPB less than 120 minutes. Serum levels of IL-8 at SIRS state were revealed statistically higher than at non-SIRS case. Duration of SIRS state was related to CPB time and serum levels of IL-6 and IL-8 just after CPB. We concluded that SIRS state is an indication for anti-cytokine therapy to prevent MOF, and it is important to shorten CPB time in order to decrease the duration of SIRS.

Cardiopulmonary Bypass↗
PubMed1996

Blood pressure at health screening as a predictor of coronary heart disease in Kyoto.

AIM: Most epidemiologic studies that have evaluated coronary risk factors have measured either mortality or morbidity of coronary artery disease (CAD) as endpoints. However, earlier detection and elimination of coronary risk factors are crucial. We therefore performed Master's double (i.e. 1.5 min x 2 = 3 min) two-step exercise electrocardiograph (ECG) test in apparently healthy asymptomatic subjects (men, n = 2274; women, n = 959) to elucidate the risk factors for early-stage CAD or silent myocardial ischemia. METHODS: We examined the possible association of blood pressure at health screening and other suspected risk factors with exercise ECG test performance. The ischemic ECG response was determined by (1) > or = 0.5 mm horizontal or sagging S-T segment depression, (2) > or = 2.0 mm J-shaped S-T segment depression, or (3) T inversion in post-exercise ECG. RESULTS: We found that 4.7% of men and 10.6% of women exhibited ischemic responses. Among males, the ischemic responders to the exercise ECG test had higher systolic and diastolic blood pressure. In addition, the male ischemic responders were older, had a higher obesity index, higher serum cholesterol, triglyceride, low-density lipoprotein (LDL)-cholesterol, protein, glucose, and uric acid levels, and a lower serum potassium level than normal responders. In contrast, the female ischemic responders to the exercise ECG test had higher systolic pressure, and higher serum cholesterol, LDL-cholesterol, and protein levels than normal responders. Mean blood pressure was correlated positively with most of the other coronary risk factors, and mild hypertensives and hypertensives had abnormal lipid, glucose, and uric acid levels in both sexes. A comparison of risk factors by age group revealed that only younger and middle-aged ischemic responders had higher blood pressure, serum cholesterol, and glucose levels than normal responders of both sexes, and that in older subjects all the differences between normal and ischemic responders became insignificant. CONCLUSIONS: Elevated blood pressure at health screening, together with abnormal lipid and glucose metabolism, might be risk factors predicting early-stage or silent CAD. The elimination of these risk factors in younger men and women seems to be important.

Adult↗
PubMed1996

[Benign infantile mitochondrial myopathy caused by reversible cytochrome c oxidase deficiency].

A 2-month-old girl had generalized weakness, profound muscular hypotonia, hepatomegaly and severe lactic acidosis. She needed ventilatory support. Muscle specimen taken at 2 months showed ragged-red fibers, abnormal mitochondria, and reduced cytochrome c oxidase (CCO) staining Biochemical analysis showed CCO activity to be reduced to about 16% of the normal mean. She received carnitine and coenzyme Q10 supplementation from the age of 3 months and abnormal blood lactate values declined to near normal values during the first three weeks. Gradually her condition started to improved: she held her head at 9 months, and walked alone at 15 months. The second biopsy specimen at 3 years and 8 months showed almost normal CCO staining and she was free of clinical signs. This case is an example of a rare benign infantile mitochondrial myopathy caused by CCO deficiency. Early diagnosis is crucial to provide intensive treatment until spontaneous clinical improvement appears. We concluded that carnitine and coenzyme Q10 supplementation was a useful treatment for clinical improvement in patients with a benign infantile mitochondrial myopathy caused by CCO deficiency.

Carnitine↗
PubMed1996

Acute appendicitis immediately after colonoscopy.

In a 69-yr-old man we treated, acute appendicitis occurred immediately after colonoscopy was performed. There were no signs or symptoms of appendicitis before colonoscopy, including in the colonoscopic findings around the cecal end and appendicular orifice. Because appendicitis is a rare complication of colonoscopy, prompt recognition should lead to early and effective treatment.

Acute Disease↗
PubMed1996

[Changes in plasma level of brain natriuretic peptide during exercise in recovery phase of myocardial infarction and the clinical significance].

Brain natriuretic peptide (BNP) plasma levels increase in patients with myocardial infarction and may reflect the degree of left ventricular dysfunction. The changes in plasma level of BNP during exercise in the recovery phase and the clinical significance were investigated in 60 patients (55 men and 5 women; mean age 62.3 +/- 9.8 years) with initial acute infarction. Cardiopulmonary exercise testing was performed with a treadmill using the ramp protocol in 60 patients in the first month and 46 in the third month after the onset of the disease. Blood samples for measuring BNP and atrial natriuretic peptide (ANP) were obtained in the resting control state and immediately after peak exercise. Plasma BNP in the first month had a significant negative correlation with anaerobic threshold (AT) and peak oxygen uptake (peak VO2), and the serial change in plasma BNP from the first to third month had a significant negative correlation with the serial change of AT (peak: r = -0.35, p < 0.05) and peak VO2 (rest: r = -0.35, p < 0.05; peak: r = -0.45, p < 0.01). The serial change of plasma ANP had no relationships with the serial change of AT or peak VO2. Because the serial change ratio of plasma BNP reflects the serial change of exercise tolerance in the recovery phase of myocardial infarction, we conclude that the serial measurement of plasma BNP level is a useful non-invasive parameter for predicting latent heart failure in patients with myocardial infarction.

Aged↗
PubMed1996

[Location of lesion on CT and motor functional outcome of the upper and lower limbs in patients with cerebral infarction].

The early diagnosis of the motor functional outcome of the upper and lower limbs in patient with cerebrovascular disease is important in establishing a treatment plan. The purpose of this study was to establish a method to evaluate the severity of low density areas on CT scans in patients with hemiparesis caused by cerebral infarction. The subjects were 186 patients who were admitted on the day of onset, showed a low density area on CT images within 5 days of onset. Of these patients, 111 had cerebral infarction, and the other 75 had reversible ischemic neurological deficit (RIND). On CT images, the low density area in the slice of corpus calosum splenium (S-1) and that of ventricular body (S-2) was measured, and its relationship with motor functional results at the time of discharge was evaluated. The motor functional level was evaluated using Brunnstrom's stage. The findings are as follows: 1) Discriminant analysis was performed using an explanatory variable of 1 and an error rates of 5% or less. The severity of the low density area could be classified into 4 major types in S-1: I-IV; and into 3 subtypes in S-2: a, b, c. The 186 patients were topographically classified using the major types and subtypes. 2) The 75 patients with type I a, b, c and II a motor function recovered within 3 weeks (RIND). Of 16 patients with type II b, 10 recovered after rehabilitation for 3 weeks or more, but the other 6 showed remaining of motor impairment in the upper limbs. Of 29 patients with type II c, 5 recovered, but the other 15 showed remaining of motor impairment in the upper limbs. 3) Of patients with type III, none recovered completely. All patients with III c had hemiparesis. 4) In 3 patients with type IV b, Stage 1.2 paresis remained in the upper limbs and Stage 4.3 in the lower limbs. Of 38 patients with type IV c, 23 showed remaining of Stage 1.2 paresis in both upper and lower limbs, and the other 10 showed Stage 1.2 paresis in the upper limbs. 5) The severity classification of the low density area on CT images was closely related to the motor functional outcome of the upper and lower limbs. Therefore, this classification is useful for determining the treatment method early after onset.

Cerebral Infarction↗
PubMed1996

[Prognosis in stage a prostate cancer].

In 39 hospitals in the Tokai region of Japan, 815 cases with prostatic cancer were registered between 1988 and 1991, 91 of which (13.3%) were diagnosed as stage A. Eighty cases of stage A cancer were subclassified into stage A1 (33 cases) or stage A2 (47 cases). A detailed investigation was performed on these 80 subclassified cases with respect to tumor markers, treatment methods and prognosis. The tumor marker, prostate specific antigen (PSA) was positive in 18.5% of the A1 cases and 53.8% of the A2 cases. Endocrine therapy was administered in 45.5% of the A1 and 78.7% of the A2 cases. There was 1 (3.0%) case of progression in the stage A1 group, and 2 cases in stage A2 group. The 5-year survival rate was 97.0% for stage A1 and 88.6% for stage A2. The prognosis of prostatic cancer in stage A was fairly good in both the A1 and A2 subclasses in our series.

Aged↗
PubMed1996

[Optimal time of the day for measuring peak expiratory flow rates in patients with asthma].

Regular measurement of peak expiratory flow rate (PEF) has been recommended as an aid in the management of asthma, but the time of the day when PEF should be measured remains unclear. We therefore sought to determine the optimal time for measuring PEF in untreated patients with mild to moderate asthma. PEF was measured in 11 patients four times daily: on waking, around noon, in the evening, and at bedtime. Significant (p < 0.05) rhythms were detected by single cosinor analysis in all patients. Analysis by the population mean cosinor method showed that the mesor was 381 +/- 120 l/m, the amplitude was 52 +/- 21 l/m, and the acrophase was at 16:28 +/- 0:55. These data indicate that, in general, PEF is lowest at 4:30 a.m. and highest at 4:30 p.m. in patients with mild to moderate asthma. We conclude that PEF should be measured early in the morning and at 4:30 p.m. in such patients.

Adolescent↗
PubMed1996

Retinoblastoma: clinical and immunocytochemical observations.

The clinical features of three cases of retinoblastoma and the histopathological and immunocytochemical findings of the retinoblastoma specimens of these patients are described. The other eye of each patient was normal. There was no family history of retinoblastoma. Fundal examination disclosed white masses in the posterior segments of the eyes. B-scan ultrasonography showed echo dense areas in the masses. Orbital tomograms showed no evidence of tissue densities. There was neither extraocular extension nor optic nerve involvement. Immunocytochemistry of paraffin-embedded tissues of the neoplasms revealed immunoreactivity with antibodies against S-100 protein, glial fibrillary acidic protein(GFAP), vimentin, neuron-specific enolase(NSE) and bcl-2. S-100, GFAP and vimentin were positive only for glial elements(reactive astrocytes) and, NSE and bcl-2 for almost all tumor cells. These findings support the previous reports that the majority of retinoblastomas are sporadic. The results of this study also support the views that retinoblastomas are composed of neuron-committed cells.

Child, Preschool↗
PubMed1996

Clinical and electron microscopic features of retinoblastoma.

A male child of 1-year, 6-month-old had a history of leukocoria of the left eye for approximately three months prior to admission into our facility. No abnormality was found in the right eye. There was negative family history of retinoblastoma. Ophthalmoscopy revealed a white mass extending from the supero-posterior part of the left globe to the posterior surface of the lens. Orbital tomograms showed no intraocular tissue densities in the mass but a B-scan ultrasound showed an echo dense area of the mass. Histopathologically areas of photoreceptor differentiation and Flexner-Wintersteiner rosettes were observed in the tumor mass by light microscope. Transmission electron microscopy disclosed the presence of prominent mitochondria on the luminal side of the cells forming rosettes and these were believed to be the component parts of the inner-segments of the photoreceptor cells. The results of this study indicate a predominant neuronal nature of the neoplastic cells with photoreceptor-like differentiation.

Cell Differentiation↗
PubMed1996

[Progressive stroke during the acute state of cerebral infarction in the territory of the internal carotid artery].

Diagnosis of deterioration of neurological deficits in the early stage after hospital admission immediately after the onset of cerebral infarction is important in establishing a treatment plan. This study investigated the clinical characteristics of progressive stroke on admission. The subjects were 309 patients admitted on the day of the onset of symptoms and showed a low density area on CT images within 5 days. There were 202 with cerebral infarction in the territory of the deep perforate arteries, 77 with cerebral infarction in the territory of the cortical branch of the middle cerebral artery (MCA), and the remaining 36 had cerebral infarction in the territory of MCA. The results were as follows: 1) Progressive stroke was observed in 71 patients (23.0%): 60 with completed stroke and 11 with reversible ischemic neurological deficits (RIND). 2) The patients with progressive stroke were clearly older than those with non progressive stroke (p < 0.05: Cochran Cox's test). 3) Progressive stroke was seen more frequently in patients with cerebral infarction of the cortical branch of the MCA and patients with occlusion of the internal carotid artery and MCA trunk than patients with cerebral infarction of the deep perforate arteries (p < 0.001: chi 2 test). 4) All patients with progressive stroke had initial evidence of deterioration of neurological deficits within 5 days after the onset, with 39 patients showing deterioration on day 2 and 13 patients showing deterioration on day 3. 5) Deterioration of neurological deficits usually stopped the day after the start of progression. The maximum period from the beginning to the end of the deterioration of neurological deficits was 7 days. 6) Progressive stroke was not seen in 11 patients who were admitted with higher cortical dysfunction and without sensory or motor disturbances, and was seen in only 8 (4%) of the 187 patients with sensory or motor disturbances without higher cortical dysfunction. 7) Progressive stroke was seen in 63 (57%) patients with sensory or motor disturbances and higher cortical dysfunction. 8) Progressive stroke was seen frequently in patients with atrial fibrillation (Af) on the ECG [P < 0.001). 9) Fifty-six of 71 patients with progressive stroke showed persistent severe motor impairment in the upper limbs. Therefore, to diagnose progressive stroke, it is useful to assess the higher cortical dysfunction and examine for Af on admission.

Aged↗
PubMed1996

Human blood lactate and ammonia levels after supramaximal uphill and downhill running.

The purposes of this study were 1) to confirm whether there is a difference in the levels of blood lactate and ammonia after supramaximal uphill and downhill running for the same short duration and 2) to examine the relationship between peak blood lactate levels and work/lean body mass (LBM), as well as the relationship between peak blood ammonia levels and work/LBM following supramaximal uphill and downhill running. Eight healthy, untrained male subjects performed supramaximal uphill and downhill running on a motor-driven treadmill for about 70 sec. Though there was a significant difference (p < 0.05) in running speed and work/LBM between supramaximal uphill and downhill running, no significant difference was found in exhaustion time or heart rate. Both the peak blood lactate and ammonia concentrations were significantly lower after downhill running than after uphill running (p < 0.05). Although there was no significant relationship between peak blood ammonia levels and work/LBM following either uphill or downhill running, significant linear relationships between the peak blood lactate levels and work/LBM were observed following uphill running (r = 0.74, p < 0.05) and downhill running (r = 0.72, p < 0.05). These results suggest that the differences in the blood lactate and ammonia concentration between supramaximal downhill and uphill running of the same duration may be due to the total recruitable muscle mass during exercise, and that peak blood lactate can be used as an index of anaerobic work capacity for untrained subjects under these running conditions.

Adult↗