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Biomedical subjects

H Yoshitomi

Publications and source records attributed to H Yoshitomi.

At least 55 records · Page 3Linked to original sources
PubMed1997

A prospective study of prognostic value of type IV collagenase activity in colorectal cancer tissue.

The purpose of this prospective study was to evaluate the prognostic value of the type IV collagenase (IVase) activity in colorectal cancer tissue on disease-free and overall survival in 31 colorectal cancer patients. The clinicopathologic factors studied for prognostic value were age, tumor location, tumor differentiation, preoperative serum levels of carcinoembryonic antigen, Dukes' stage, and IVase activity in colorectal cancer tissue. IVase activities in colorectal cancer tissue were significantly higher in the group of patients with recurrences than in the group without recurrences (P = 0.019). Patients with high IVase activity in colorectal cancer tissue had a significantly shorter disease-free survival (P = 0.0016) and overall survival (P = 0.022) time than those with low IVase activity. Univariate and multivariate analysis showed that significant prognostic factors for disease-free survival were Dukes' stage (P = 0.029, P = 0.046, respectively) and IVase activity status (P = 0.0016, P = 0.0026, respectively). With respect to overall survival, only IVase activity status provided significant predictive value in multivariate analysis (P = 0.041). This prospective study suggests that IVase activity is a valuable prognostic factor in colorectal cancer patients.

Adult↗
PubMed1997

Involvement of MAP kinase and c-fos signaling in the inhibition of cell growth by somatostatin.

Somatostatin significantly suppressed cell growth of the mouse insulinoma-derived cell line MIN6. MIN6 cells exhibited high-affinity binding of somatostatin with 50% inhibitory concentration value of 0.9 nM. RNA blot analysis revealed that MIN6 cells expressed only SSTR3 among the five somatostatin receptors so far identified. Treatment of MIN6 cells with somatostatin significantly reduced the serum-induced c-fos expression levels. On the other hand, somatostatin (100 nM) treatment of MIN6 cells cultured in medium containing 10% serum transiently increased c-fos expression levels to 282 +/- 4.7% and then significantly decreased them to 27 +/- 7.6% of the levels before treatment. Mitogen-activated protein (MAP) kinase activity transiently increased to 656 +/- 91.2% and decreased thereafter to 39 +/- 13.3% of the activity before the addition of somatostatin (100 nM) into the medium. In addition, the stimulatory effect of somatostatin on c-fos expression and MAP kinase activity (early effect) was not altered by pertussis toxin (PTX), whereas the suppressive effect of somatostatin on c-fos expression and MAP kinase activity (late effect) was mitigated by PTX. These findings suggest that an inhibition of c-fos expression mediated by cross talk between PTX-sensitive G protein signaling and receptor tyrosine kinase signaling is one of the mechanisms by which somatostatin inhibits cell growth in MIN6 cells.

Animals↗
PubMed1997

Prediction of outcome of electrical cardioversion by left atrial appendage flow velocities in atrial fibrillation.

We evaluated the usefulness of left atrial appendage (LAA) flow velocity during atrial fibrillation as an objective measure for prediction of the outcome of electrical cardioversion. Left atrial appendage peak velocities were measured by transesophageal echocardiography before cardioversion in 56 patients. Left atrial thrombus was demonstrated in 6 (11%) of these patients. Cardioversion was then performed in the 50 patients who did not have a thrombus and in 1 patient whose left atrial thrombus disappeared after anticoagulant therapy (n = 51). Thirty-eight patients converted to sinus rhythm which remained stable until discharge (initial success group). Of these, long-term (> 6 months) maintenance of sinus rhythm was achieved in 31 patients (82%). Five patients with almost no detectable appendage contractions during atrial fibrillation were classified in the initial failure group. The peak LAA flow velocity was significantly higher in patients with the initial success group compared with the patients in the initial failure group (25.6 +/- 12.0 vs 15.3 +/- 10.7 cm/s, respectively; p < 0.01). Left atrial appendage flow velocity during atrial fibrillation may be useful for identifying candidates for electrical cardioversion.

Adult↗
PubMed1997

Ethanol sclerosis: one of the best treatments for thymic cyst in very elderly patients?

An 83-year-old female patient with a giant thymic cyst that was successfully treated by percutaneous aspiration and ethanol injection. The patient had complained of coughing and chest discomfort for several years. A chest X-ray film revealed the shadow of a large abnormal mass in the anterior mediastinum. We diagnosed it as a thymic cyst. The patient refused surgery because of her age. We chose a less invasive therapy, namely, ethanol sclerosis of the cyst. The cyst was successfully treated without any complications, and no recurrence was found at the one-year follow-up. This therapy may be one of the best treatments for thymic cysts, especially in very elderly patients.

Aged↗
PubMed1997

[Influence of atrioventricular delay on pulmonary capillary wedge pressure in two patients with hypertrophic obstructive cardiomyopathy during dual chamber pacing].

Recently, dual chamber pacing has been proposed as a new treatment for left ventricular outflow tract obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM). However, dual chamber pacing may be detrimental to both systolic and diastolic function of the left ventricle, particularly at short atrioventricular (AV) delay. A 45-year-old man and a 58-year-old woman with HOCM underwent transesophageal echocardiography and hemodynamic study at various AV delays (50-200 msec). In both patients, shortening of AV delay increased pulmonary capillary wedge pressure. The transesophageal echocardiographic study showed a remarkable shortening of the ventricular filling duration at atrial systole and an increase of pulmonary venous reversal at short AV delay (50-100 msec). Therefore, short AV delay was detrimental to diastolic filling and thus increased pulmonary capillary wedge pressure. Transesophageal echocardiographic study may be helpful for defining the optimal AV delay more precisely in HOCM during dual chamber pacing.

Blood Flow Velocity↗
PubMed1996

Doppler estimation of pulmonary artery end-diastolic pressure using contrast enhancement of pulmonary regurgitant signals.

Pulmonary artery (PA) end-diastolic pressure is used as an estimate of PA wedge pressure. We evaluated contrast enhanced pulmonary regurgitant signals in the assessment of PA end-diastolic pressure in 24 patients in a critical care unit. Right atrial pressure was estimated by the percent decrease of the inferior vena caval diameter with inspiration. Weak or absent pulmonary regurgitant signals were enhanced by sonicated albumin (Albunex) in 23 patients (96%). The Doppler-determined PA end-diastolic pressure (the sum of the pulmonary regurgitant pressure gradient at end-diastole and the right atrial pressure) was significantly correlated with the catheter-determined PA end-diastolic pressure (y = 0.85x + 1.72, r = 0.93). Compared with invasive hemodynamic monitoring, the contrast-enhanced Doppler technique using Albunex is effective for measuring PA end-diastolic pressure, even in critically ill patients.

Aged↗
PubMed1996

Effects of heart rate on coronary circulation and external mechanical efficiency in elderly hypertensive patients with left ventricular hypertrophy.

BACKGROUND AND HYPOTHESIS: Mechanisms of heart failure in elderly hypertensive patients with hypertrophy have not been studied sufficiently. We hypothesized that impaired increment of coronary blood flow in response to increases in heart rate could be responsible for the occurrence or aggravation of heart failure. METHODS: To test this hypothesis, we measured coronary hemodynamics and lactate balance during basal conditions and atrial pacing in 21 elderly patients aged > or = 65 years (mean 74 +/- 6 years) without coronary arterial disease: 7 normotensive control patients (Group 1), 7 hypertensive hypertrophic patients without a history of congestive heart failure (Group 2), and 7 patients with such history (Group 3). Coronary sinus blood flow (CSBF) was measured in coronary sinus using a thermodilution catheter. RESULTS: During basal conditions, heart rate did not differ among the three groups (67 +/- 3 in Group 1, 65 +/- 11 in Group 2, and 63 +/- 6 beats/ in Group 3). CSBF was significantly higher in the two hypertrophic groups than in the control group, but CSBF normalized by left ventricular mass was significantly lower in both hypertrophic groups. External mechanical efficiency (EME) obtained as left ventricular work divided by myocardial oxygen consumption did not differ among groups during basal conditions (36 +/- 9% in Group 1, 35 +/- 8% in Group 2, and 29 +/- 9% in Group 3, NS). During atrial pacing to increase heart rate by 25 +/- 5% (lower) and 54 +/- 6% (higher), the increases in CSBF were markedly limited in both hypertrophic groups, and the response in Group 3 was more depressed than that in Group 2. EME did not change in the control group or in Group 2, but did decrease to 21 +/- 5% in Group 3 during the higher pacing rate (p < 0.01 vs. basal conditions). In this group, the relationship between EME and heart rate showed a significant negative correlation (r = -0.56, p = 0.02). Lactate balance in coronary sinus blood showed a tendency to production in Group 3 during the higher pacing rate, suggesting myocardial ischemia. CONCLUSION: These findings suggest that in hypertensive hypertrophic patients with a history of heart failure, the coronary circulation system is vulnerable to increasing heart rate. In medical treatment of elderly hypertensive patients, control of heart rate in addition to blood pressure control should be considered to minimize the occurrence or aggravation of heart failure.

Aged↗
PubMed1996

Determination of total hydroxyproline and proline in human serum and urine by HPLC with fluorescence detection.

A method to measure total hydroxyproline (Hyp) and proline (Pro) in human serum and urine by HPLC was developed. Hyp and Pro in acid hydrolysates of serum and urine were derivatized with 4-(5,6-dimethoxy-2-phthalimidinyl)phenysulfonyl chloride after treatment with o-phthaladehyde and cleanup on Bond Elut C18 column. The derivatives of imino acids were separated on a reversed phase column by gradient elution with acetonitrile and phosphate buffer (1 mmol/l, pH 7) and detected by fluorescence measurement at 315 nm (excitation) and 385 nm (emission). Detection limits for both Hyp and Pro were 10 fmol per injection. The within-day and day-to-day relative standard deviations for Hyp and Pro in serum and urine were less than 3.19%. The recoveries of Hyp and Pro added to serum and urine were about 100%. The present method was applied to determine total Hyp and Pro in serum and urine from normal subjects and patients with chronic renal failure.

Adult↗
PubMed1995

Homooligopeptides composed of hydrophobic amino acid residues interact in a specific manner by taking alpha-helix or beta-structure toward lipid bilayers.

In order to investigate the role of each amino acid residue in determining the secondary structure of the transmembrane segment of membrane proteins in a lipid bilayer, we made a conformational analysis by CD for lipid-soluble homooligopeptides, benzyloxycarbonyl-(Z-)Aaan-OEt (n = 5 - 7), composed of Ala, Leu, Val, and Phe, in three media of trifluoroethanol, sodium dodecyl sulfate micelle, and phospholipid liposomes. The lipid-peptide interaction was also studied through the observation of bilayer phase transition by differential scanning calorimetry (DSC). The CD studies showed that peptides except for Phe oligomers are present as a mainly random structure in trifluoroethanol, as a mixture of alpha-helix, beta-sheet, beta-turn, and/or random in micelles above the critical micellization concentration and preferably as an extended structure of alpha-helical or beta-structure in dipalmitoyl-D,L-alpha-phosphatidylcholine (DPPC) liposomes of gel state. That the beta-structural content of Val oligomers in lipid bilayers is much higher than that in micelles and the oligopeptides of Leu (n = 7) and Ala (n = 6) can take an alpha-helical structure with one to two turns in lipid bilayers despite their short chain lengths indicates that lipid bilayers can stabilize the extended structures of both alpha-helical and beta-structures of the peptides. The DSC study for bilayer phase transition of DPPC/peptide mixtures showed that the Leu oligomer virtually affects neither the temperature nor the enthalpy of the transition, while Val and Ala oligomers slightly reduce the transition enthalpy without altering the transition temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1995

Application of curdlan to controlled drug delivery. III. Drug release from sustained release suppositories in vitro.

The use of curdlan, a natural beta-1,3-glucan, in the preparation of sustained release suppositories was studied in vitro. To prepare the suppositories, indomethacin, prednisolone or salbutamol sulfate was mixed with curdlan gel. Preparation conditions, including heating time and curdlan concentrations of 5 and 10%, had little effect on the drug release. The tonicity (hypotonic or isotonic) of the media for the suppository preparation and for in vitro drug release study also had little effect on drug release. However, the heating temperature during gel preparation, the drug amount in the suppository and the type of release media did affect drug release. It was found that drug release was sustained and diffusion-controlled in the three drugs. And finally, curdlan can be applicable for use in a sustained release suppository.

Albuterol↗
PubMed1995

[Five cases of ASD-PDA complex: a review of 38 cases reported in Japan].

Five cases of ASD-PDA complex were experienced. The incidence of ASD-PDA complex was 1.2% of CHD in our institution. The age at operation was ranged from 10 days after birth to 2 years of age. Four patient were male and 1 was female. Also, 4 patients had noncardiac anomalies, including Down syndrome, microcephaly, cleft palate, micrognathia, and cranioschisis. All patient had moderate or severe pulmonary hypertension. Three patients received ASD and DA closure under cardiopulmonary bypass, however, 2 patients were succeeded in decreasing CTR and pulmonary vascular shadow by ligation of DA. Operative and hospital mortality was none. We also studied concerning clinical features and surgical treatment by the review of 38 cases reported in Japan and our 5 cases.

Ductus Arteriosus, Patent↗
PubMed1994

Effects of supine and lateral recumbent positions on pulmonary venous flow in healthy subjects evaluated by transesophageal Doppler echocardiography.

OBJECTIVES: This study attempted to evaluate the effects of supine and lateral recumbent positions on pulmonary venous flow by transesophageal Doppler echocardiography in healthy subjects. BACKGROUND: Although transesophageal echocardiographic examination is usually performed with the patient lying in the left lateral decubitus or supine position, little attention has been paid to the effects of these positions on pulmonary venous flow. METHODS: We performed pulsed Doppler transesophageal echocardiography of the left and right pulmonary veins in 16 normal subjects as they lay in the left and right lateral decubitus and supine positions. RESULTS: Data are reported as mean value +/- SD. Adequate recordings were obtained in 12 subjects (75%). In the left pulmonary vein, peak systolic velocity and time-velocity integral of systolic flow increased significantly in the left compared with the right lateral decubitus position (56 +/- 12 vs. 44 +/- 13 cm/s, p < 0.05, and 15 +/- 4 vs. 9 +/- 4 cm, p < 0.05, respectively). In the right pulmonary vein, peak systolic velocity and time-velocity integral of systolic flow decreased significantly in the left compared with the right lateral decubitus position (38 +/- 10 vs. 48 +/- 9 cm/s, p < 0.05, and 9 +/- 2 vs. 12 +/- 2 cm, p < 0.05, respectively). There were no significant differences between positions in peak diastolic flow velocity, time-velocity integral of diastolic flow or peak velocity of flow reversal at atrial contraction. CONCLUSIONS: Pulmonary venous systolic peak velocities and time-velocity integrals of systolic flow increase when the pulmonary venous recording is from the recumbent subject's lower side. Therefore, the effects of position should be considered in evaluating left ventricular diastolic function by transesophageal Doppler echocardiography.

Adult↗
PubMed1994

[Cooley operation for hypertrophic obstructive cardiomyopathy associated with Noonan Syndrome following Morrow operation--a case report].

A 21-year-old female underwent ventricular septoplasty (Cooley operation) for severe left ventricular outflow tract obstruction (LVOTO), which had developed after performance of a Morrow operation at the age of 14. Diagnosis of Noonan syndrome and hypertrophic obstructive cardiomyopathy had been already established by clinical manifestations and a myocardial biopsy. The septoplasty technique and valve replacement could be successfully used to repair the residual LVOTO and aortic regurgitation. We found that this approach was one of the most convenient and provided effective management of LVOTO. Post-operative course has been uneventful and the patient remains completely well as of the 18th months after surgery.

Adult↗