Search PubMed⌕ Search

Biomedical subjects

T Ishihara

Publications and source records attributed to T Ishihara.

At least 109 records · Page 6Linked to original sources

Improvement of exercise tolerance by single lead VDD pacemaker: evaluation using cardiopulmonary exercise test.

We used a cardiopulmonary test to assess the physiological benefit of single lead VDD pacing in ten patients (six men, four women; aged 32-84 years, mean 69 years) with atrioventricular block. Maximal symptom-limited treadmill exercise test using a ramp protocol was performed under VDD and VVIR or VVI pacing (VVI) in random sequence. The pacemaker was then programmed to the VDD mode, and Holter ECG was recorded in nine patients. Compared with findings during the VVI, the VDD mode had a greater chronotropic response (mean maximal heart rate, VDD 106 +/- 17 beats/min vs VVI 79 +/- 19 beats/min, P = 0.03), and was associated with prolongation of exercise duration (VDD 11.2 +/- 2.9 minute vs VVI 10.5 +/- 3.1 minute; P = 0.01), and the onset of anaerobic threshold at a higher oxygen uptake (VDD 12.4 +/- 3.4 mL/min per kilogram vs VVI 10.0 +/- 2.1 mL/min per kilogram; P < 0.01). Atrial sensing was recognized in almost all normal sinus P waves for all cases examined using Holter ECG. Thus, chronotropic response during exercise by VDD pacemaker improved exercise tolerance, indicating that a VDD pacemaker might be useful for patients requiring physical activity.

Adult↗

Increased migration in late G(1) phase in cultured smooth muscle cells.

Migration and proliferation of smooth muscle cells (SMC) contribute to neointimal formation after arterial injury. However, the relation between migration and proliferation in these cells is obscure. To discriminate between migration and proliferation, we employed a migration assay of SMC at different phases of the cell cycle. Serum-deprived SMC were synchronized in different phases of the cell cycle by addition of serum for various periods of time. Migration induced by platelet-derived growth factor B-chain homodimer was maximal in SMC that were predominantly in the late G(1) (G(1b)) phase. In addition, in nonsynchronized SMC, 65-75% of SMC that had migrated were in the G(1b) phase. Phosphorylated myosin light chain was enriched around the cell periphery in SMC in the G(1b) phase compared with SMC in the other cell cycle phases. Interestingly, the Triton X-100-insoluble fraction of myosin was remarkably decreased in G(1b)-enriched SMC. These findings suggest that migratory activity of SMC may be coupled with the G(1b) phase. The phosphorylation and retention of myosin might explain some of the properties responsible for increased migration.

Actins↗

Cardiac arrhythmias and left ventricular hypertrophy in dipper and nondipper patients with essential hypertension.

To evaluate the behavior of cardiac arrhythmias in dipper and nondipper hypertensive patients, 48-h ambulatory blood pressure monitoring, 24-h Holter electrocardiogram recording and echocardiographic studies were performed in 56 untreated outpatients with essential hypertension. These patients were divided into 2 groups according to the presence (dipper, n=33) or absence (nondipper, n=23) of reduction of both systolic and diastolic blood pressure during nighttime by an average of more than 10% of daytime blood pressure. Mean 48-h systolic and diastolic blood pressures did not differ between the 2 groups. Nondipper patients had a significantly larger left atrial dimension (31.9+/-3.8 vs 35.6+/-3.7 mm; p<0.01), left ventricular mass index (114+/-26 vs 136+/-36 g/m2; p<0.05), as well as a larger number of total supraventricular (16+/-19 vs 89+/-197 beats; p<0.05) and ventricular ectopic beats (7+/-14 vs 47+/-96 beats; p<0.05) during daytime as compared with dippers. In conclusion, nondipper hypertensive patients are likely to experience supraventricular and ventricular arrhythmias more frequently than dippers. A blunted nocturnal blood pressure fall may be involved in the appearance of cardiac arrhythmias in patients with essential hypertension.

Adult↗

Synthesis of regioselectively protected forms of cytidine based on enzyme-catalyzed deacetylation as the key step.

N4-Acetylcytidine (77%) and 2',3'-O, N4-triacetylcytidine (95%) were obtained from the hydrolysis of a common precursor, the peracetylated form of cytidine with Aspergillus niger lipase (Amano A) and Burkholderia cepacia esterase (SC esterase S), respectively, under very mild conditions. The experimental procedure for the conversion of triacetylcytidine to a corresponding phosphoramidite (82%), an intermediate for sugar nucleotide synthesis, is also elaborated.

Acetylation↗

A role of free insulin-like growth factor-I in dawn phenomenon in children and adolescents with type 1 diabetes mellitus.

It has been hypothesized that a decreased amount of the free form of insulin-like growth factor-I (fIGF-I) results in morning hyperglycemia in patients with type 1 diabetes mellitus. In this study, we attempted to clarify the role of fIGF-I in relation to total IGF-I (tIGF-I) and its related peptides or proteins in type 1 diabetes. Forty-seven patients with type 1 diabetes, mean age 13.7 years, were evaluated. Blood samples were obtained for the measurement of BG at 0200, 0400 and 0700, and of insulin, total IGF-I (tIGF-I), fIGF-I, IGFBP-1 and IGFBP-3 at 0700. The SD scores (SDS) were determined for the levels of tIGF-I, flGF-I, IGFBP-1 and IGFBP-3 by using Japanese reference data. The morning increase in BG (deltaBG(4-7)) correlated significantly with fIGF-I SDS (r=-0.352, p=0.0152) and IGFBP-1 SDS (r=0.438, p=0.0021), but did not correlate significantly with the fIGF-I level itself or the ratio of fIGF-I to tIGF-I (f/t IGF-I ratio). Hereupon, the f/t IGF-I ratio correlated positively with fIGF-I SDS (r=0.541, p=0.0003). The mean+/-SD in the f/t IGF-I ratio was 0.94+/-0.43%, and that in fIGF-I SDS was -0.50+/-1.32. The level of IGFBP-I SDS correlated negatively with fIGF-I SDS (r=-0.472, p=0.0008) and insulin (r=-0.365, p=0.0116). We suggest that the morning level of fIGF-I SDS, rather than the fIGF-I level itself, may be a useful marker of decreased insulin-like bioactivity in the dawn phenomenon in type 1 diabetes mellitus.

Adolescent↗

Successfully treated complete atrioventricular block with corticosteroid in a patient with cardiac sarcoidosis: usefulness of gallium-67 and thallium-201 scintigraphy.

A 71-year-old male with sarcoidosis was followed for 6 years without steroid therapy. He was admitted because of complete atrioventricular block. Chest X-ray showed hilar lymphadenopathy. Echocardiogram showed mild left ventricular hypertrophy without local wall thinning. Cardiac sarcoidosis was diagnosed by a defect of Thallium-201 (Tl-201) imaging and abnormal uptake of Gallium-67 (Ga-67). After the start of corticosteroid therapy, complete atrioventricular block was recovered. Abnormal uptake of Ga-67 was improved. Tl-201 and Ga-67 are useful to diagnose cardiac sarcoidosis, to evaluate the lesion of cardiac involvement and to estimate the efficacy of corticosteroid therapy.

Aged↗

Hypertrophic cardiomyopathy complicated with cardiac amyloidosis.

The echocardiographic findings of hypertrophic cardiomyopathy (HCM) are very similar to those of cardiac amyloidosis. A 76-year-old Japanese man was admitted for treatment of early stage gastric cancer in July 1996. His electrocardiogram indicated left ventricular hypertrophy and echocardiography showed left ventricular hypertrophy with asymmetric septal hypertrophy. He was re-admitted complaining of dyspnea on effort and pretibial edema in October 1998. The amplitude of QRS complex on electrocardiogram was decreased. Echocardiogram showed left ventricular wall thickening with granular sparkling. He was diagnosed as HCM with cardiac amyloidosis.

Aged↗

An immunohistochemical study of cytokeratins in skin-limited amyloidosis.

The frequency of amyloid deposits in cases of seborrheic keratosis was investigated In addition, the origin of amyloid protein(s) in lichen amyloidosis, macular amyloidosis and seborrheic keratosis was studied by immunohistochemical staining using a panel of anti-cytokeratin (CK) monoclonal antibodies. Amyloid deposits were found in 41 of 327 specimens (12.5%) from 301 cases of seborrheic keratosis. Amyloid deposits in seborrheic keratosis reacted with 6 of 12 CK antibodies and in lichen and macular amyloidosis (20 specimens) reacted with 5 of 12 CK antibodies. In seborrheic keratosis, antibody DE-K10 (labeling CK10) reacted with amyloid in 17 of 36 cases, antibody 34betaE12 (labeling CK1, 5, 10, 14) reacted in 33 of 39 cases, and antibody MNF116 (labeling CK5, 6, 8, 17) reacted in 32 of 35 cases. Among 20 specimens from lichen and macular amyloidosis, the three antibodies reacted with amyloid in the following rates: 1 with antibody DE-K10, all 20 with antibody 34betaE12, and 6 with antibody MNF116. These results suggest that amyloid deposits in seborrheic keratosis and lichen and macular amyloidosis may derive from epidermal cytokeratins.

Adult↗

Analysis of plasma cell clonality in localized AL amyloidosis.

AL amyloidosis is characterized by fibrillar tissue deposits composed of monoclonal immunoglobulin light chains(IgLs). It has been speculated that clonal expansion of plasma cells may occur locally and produce amyloidogenic IgLs. Both immunohistochemistry and molecular genetics are useful for examining plasma cell clonality from paraffin-embedded tissue sections, which are easy to obtain. We evaluated plasma cell clonality in 16 biopsy cases of localized AL amyloidosis using these two methods. A clonal excess of plasma cells was detected in 6 (37.5%) cases immunohistochemically, in 10 (62.5%) cases molecularly, and in 13 (81.3%) cases by at least one of the two methods. These results support local synthesis of the light chain proteins in localized AL amyloidosis.

Adult↗

Novel assay for measuring serum conjugated bilirubin and its clinical relevance.

We have developed a new enzymatic assay for the determination of conjugated bilirubin (Bc) using stable liquid reagents. In this assay, only Bc is selectively oxidized by bilirubin oxidase at pH 5. 0 in the presence of nitrilotris (methylenephosphonic acid) trisodium salt, ethylenediaminetetraacetic acid disodium manganese (II) salt, and 4-hydroxy-2,2,6,6,-tetramethylpiperidine 1-oxyl. Bc is quantitatively determined from a decrease in the absorbance at 450 nm caused by Bc oxidization. The reagent solutions of the assay were developed so that they could be stably stored for one year together with bilirubin oxidase, in order to eliminate the need to prepare working solutions every time they are required. The assay has good reactivity, differentiability, measurability, and precision. Neither ascorbic acid nor hemoglobin interfered with the measurement. Bc values determined by the assay reflected more clearly the pathophysiological condition of hepatobiliary disease patients with jaundice than the values of total bilirubin or direct bilirubin determined by conventional methods. From these observations, we concluded that this Bc assay is valuable for the evaluation of jaundice.

Bilirubin↗

Angiographically demonstrated coronary collaterals predict residual viable myocardium in patients with chronic myocardial infarction: a regional metabolic study.

Angiographical demonstration of coronary collateral circulation may suggest the presence of residual viable myocardium. The development of coronary collaterals was judged according to Rentrop's classification in 37 patients with old anteroseptal myocardial infarction and 13 control patients with chest pain syndrome. The subjects with myocardial infarction were divided into 2 groups: 17 patients with the main branch of the left coronary artery clearly identified by collateral blood flow from the contralateral coronary artery [Coll(+)group, male/female 10/7, mean age 56.6 years]and 20 patients with obscure coronary trunk [Coll(-)group, male/female 16/4, mean age 54.9 years]. Thallium-201 myocardial scintigraphy and examination of local myocardial metabolism were carried out by measuring the flux of lactic acid under dipyridamole infusion load. Coronary stenosis of 99% or total occlusion was found in only 5 of 20 patients (25%)in the Coll(-)group but in 16 of 17 patients(94%)in the Coll(+)group(p < 0.001). Redistribution of myocardial scintigraphy was found in 11 of 15 patients(73%)in the Coll(+)group, but only 3 of 18 patients (17%)in the Coll(-)group(p < 0.01). The myocardial lactic acid extraction rate was--13.2 +/- 17.0% in the Coll(+)group, but 9.1 +/- 13.2% in the Coll(-)group(p < 0.001). These results suggest that coronary collateral may contribute to minimizing the infarct area and to prediction of the presence of viable myocardium.

Adult↗

[Video assisted thoracic surgery for the treatment of catamenial pneumothorax].

Video assisted thoracic surgery (VATS) was applied in 3 cases of pneumothorax combined with pathologic changes in the diaphragm (two cases of catamenial pneumothorax and one case of suspected catamenial pneumothorax). Case 1, 39-year-old woman, was preoperatively diagnosed as catamenial pneumothorax in the right lung. Thoracoscope was inserted through the 5th intercostal anterior axillary line and the lesion with the pathologic changes in the central tendon of the diaphragm was incised and sutured with Endo-GIA and Endo-STAPELAR. Case 2, 42-year-old woman, was confirmed to have pathologic changes in the central tendon after insertion of thoracoscope through the 5th intercostal anterior axillary line. Minithoracotomy of 50 mm in size was added close to the center of the diaphragm and direct incision and suture of that part were performed. Case 3, 47-year-old woman, underwent thoracoscopy through the 5th intercostal mid-axillary line and bulla in the S2 interlobar surface was incised with Endo-GIA. In this case, the diaphragm was partially incised through additional minithoracotomy because some lesions were detected on that part. VATS can fully be carried out for pathologic changes in the diaphragm in catamenial pneumothorax. Since catamenial pneumothorax may be complicated with another pathologic changes in the diaphragm (Case 1) or in the visceral pleura (Case 3), the whole thoracic cavity, including diaphragm and visceral pleura, should be carefully observed under thoracoscopy. Application of minithoracotomy-associated thoracoscopic surgery is a useful method in the case to whom catamenial pneumothorax is definite or suspected.

Adult↗

[Seven cases of brain metastasis from papillary thyroid carcinoma].

Brain metastases from differentiated thyroid carcinoma are extremely rare and carry a poor prognosis. We describe here clinical details of 7 cases of brain metastases from papillary thyroid carcinoma. Of 153 patients with metastases from differentiated thyroid carcinoma (papillary in 123, follicular in 30) treated at our institution between 1981 and 1999, 7 patients (4.6%) had brain metastases. Histologically, the primary tumor was papillary carcinoma in all 7 cases. Four were males and 3 were females. The median age at first diagnosis of distant metastases was 63 yr (range, 47-76 yr). Of these patients, one had brain metastases only and six had metastases to the lungs as well. Five of these patients were treated with 131I. Three of these 5 patients had marked uptake in the metastases (131I positive) on post-therapy 131I scans and another 2 patients had no significant activity (131I negative) in both pulmonary and brain metastatic lesions. One of 3 patients with 131I positive lesions had intense activity in the brain tumor, but no uptake in multiple pulmonary metastatic tumors. In a patient with 131I positive brain metastases, the tumors progressed rapidly after 131I therapy. In another one patient, acute hemorrhage of the tumor occurred four days after 131I therapy, requiring surgical removal. Loner case of 131I negative 2 patients was treated with radiosurgery (gamma-knife) and complete reduction in tumor volume was observed. On the other hand, one of 2 patients receiving no 131I therapy had radiosurgery (x-knife) and remaining one received conventional external radiation and chemotherapy for small solitary brain and pulmonary metastatic tumors. These therapeutic interventions were useful in both cases. The mean length of survival after the development of brain metastases in the five patients who died of the disease was 30 months. One patient treated with x-knife has been alive at 21 months and another one who has 131I uptake in the brain tumor without uptake in lung lesions has been alive 15 months after diagnosis of brain metastasis. These results indicate that it is important to detect brain metastasis by imaging techniques and Tg measurements and give treatment as early as possible since the brain is the third most common distant metastatic site and the prognosis is poor.

Adolescent↗

Significance of brain natriuretic peptide measurement as a diagnostic indicator of cardiac function.

Brain natriuretic peptide (BNP) is increased in patients with heart failure due to myocardial infarction and cardiac hypertrophy, in proportion to the severity of left ventricular dysfunction. The aims of this study were to clarify the clinical features of BNP and to determine the diagnostic value of BNP for mass screening. The subjects were 818 office workers (565 males and 253 females; mean age 47 +/- 12 years) who participated in a 1996 routine health check at Kansai University All individuals were examined for blood pressure, serological findings, ECG and plasma BNP level. Thirty-three males underwent 2-D echocardiography. Plasma BNP levels were measured using IRMA (immunoradiometric assay). The results were as follows: (1) BNP levels in females were higher than those in males for healthy subjects (N = 551), in each age group from 20 to 60 years. (2) BNP levels increased with age. (3) There were significant correlations between BNP level and systolic blood pressure and creatinine level. (4) There were significant differences in BNP level between the hypertensive groups with and without hypertensive ECG changes and the age-matched healthy control group. (5) Marked correlations were observed between BNP level and left ventricular wall thickness, fractional shortening, deceleration time and peak early filling velocity. (6) A BNP cut-off-point of 25 pg/ml was best for detecting LV diastolic dysfunction and LV hypertrophy. Measurement of BNP is useful for detecting asymptomatic heart failure in the general population, and is a clinical marker useful in preventing symptomatic heart failure.

Adult↗

[Kallmann syndrome].

Explore the source record for details and available documents.

Cell Adhesion Molecules, Neuron-Glia↗

Laparoscopy with ultrasonographic guidance of intraamniotic methotrexate injection for ectopic pregnancy. A report of two cases.

BACKGROUND: The efficacy of laparoscopic intratubal injection of methotrexate is reportedly controversial. CASES: A 29-year-old woman with an interstitial-isthmic pregnancy and a 30-year-old woman with an ampullary pregnancy surrounded by dense adhesions were treated with intraamniotic injection of methotrexate with ultrasonographically guided laparoscopy (LUS). The ectopic pregnancies resolved quickly, without further intervention. The human chorionic gonadotropin concentrations were negligible by 18 and 25 days. CONCLUSION: Intraamniotic methotrexate injection with LUS is an effective treatment for unruptured interstitial and tubal pregnancies in patients with dense adhesions.

Abortifacient Agents, Nonsteroidal↗

Relation between QT interval dispersion and heart rate.

Because the relation between QT dispersion (QTd) and heart rate (HR) are different from that between QT interval and HR, QTd could be overadjusted at a high HR and be underadjusted at a slow HR if we use Bazett's formula to adjust QTd. HR adjustment of QTd is not needed to evaluate repolarization dispersion.

Aged↗