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Biomedical subjects

H Gen

Publications and source records attributed to H Gen.

At least 19 recordsLinked to original sources
PubMed2001

p53 and H-ras mutations and microsatellite instability in renal pelvic carcinomas of NON / Shi mice treated with N-butyl-N-(4-hydroxybutyl)-nitrosamine: different genetic alteration from urinary bladder carcinoma.

We previously reported p53 mutations to be frequent (greater than 70%), whereas both H-ras mutations and microsatellite instability (MSI) were infrequent (about 10%), in urinary bladder carcinomas (UBCs) and their metastatic foci in the N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced mouse urothelial carcinogenesis model. In the present study, an analysis of p53 and H-ras mutations as well as MSI was performed on 12 renal pelvic carcinomas (RPCs) and 8 metastatic or invading foci produced by the same experimental procedure. Histologically, 10 of the RPCs were transitional cell carcinomas and the remaining 2 were squamous cell carcinomas. p53 mutations were infrequent and only found in one primary RPC (8%), its metastatic foci and an invading lesion in another animal (in a total 2 of 12; 17%). H-ras mutations were slightly more frequent (found in 3 of 12 animals; 25%), 4 of 5 involving codon 44, GTG to GCG, not a hot-spot reported for human cancers. In two cases, H-ras mutations were confined to lung metastasis and not detectable in their primary RPCs. MSI analysis was available for 6 pairs of primary RPCs and their metastatic foci, and 4 animals (67%) had MSI at one or more microsatellite loci. Overall, the distribution of genetic alterations differed from that in UBCs produced by the same experimental protocol. The results thus suggest that different genetic pathways may participate in carcinogenesis of the upper and lower urinary tract due to BBN.

Animals↗
PubMed2001

Primary cardiac angiosarcoma detected by magnetic resonance imaging but not by computed tomography.

A 51-year-old man with a primary angiosarcoma of the right atrium is reported. The angiosarcoma was not detected by transthoracic echocardiography or computed tomography, but magnetic resonance imaging and transesophageal echocardiography did show the tumor of the right atrial free wall. We performed a transvenous endomyocardial biopsy of the tumor under the guidance of transesophageal echocardiography and made the pathological diagnosis. This case demonstrates the advantage of magnetic resonance imaging and transesophageal echocardiography for tumor detection over transthoracic echocardiography and computed tomography and the usefulness of transesophageal echocardiography for guiding the right atrial endomyocardial biopsy procedure.

Biopsy↗
PubMed2001

Relationship between papillary muscle size and benefit to cardiac function in mitral valve replacement with chordal preservation.

BACKGROUND AND AIM OF THE STUDY: Mitral valve replacement (MVR) with chordal preservation in patients with chronic mitral regurgitation (MR) has been reported to maintain systolic function of the left ventricle. However, the benefits of MVR with chordal preservation are not always predictable. The study aim was to ascertain the influence that papillary muscle (PM) size has on cardiac function after MVR with chordal preservation. METHODS: Postoperative regional shortening and its relationship with PM size were investigated by two-dimensional echocardiography in 18 patients who underwent MVR with chordal preservation, and nine patients without chordal preservation between 1986 and 1998 at Tenri Hospital. The PM cross-sectional area was measured in each patient, as well as postoperative fractional shortening (FS) of the septolateral, anteroposterior and vertical dimensions of the left ventricle. The technique of preserving all chordae tendineae involved reattaching the anterior leaflet chordae to the mitral annulus near each commissure. RESULTS: Postoperative FS of the septolateral and anteroposterior dimensions was better in patients with chordal preservation than in those without. In the former subgroup, a larger PM was associated with better FS of the left ventricle in the septolateral dimension (anterior PM, p <0.001, r = 0.78; posterior PM, p = 0.0010, r = 0.69), but not in the anteroposterior or vertical dimensions. This discrepancy in the relationship between PM size and functional benefits among the three dimensions may be related to the direction in which the PMs are suspended in our technique, or its effect on regional left ventricular function. CONCLUSION: The present study indicated that PM size may be used as a factor to better predict the outcome of MVR with chordal preservation.

Adult↗
PubMed2000

Clinical characteristics of patients with fresh left ventricular thrombus.

The present study analyzed the clinical backgrounds of 9 patients with fresh left ventricular thrombus (LVT) detected by two-dimensional echocardiography during the past 5 years. Patients with acute myocardial infarction were excluded. Left ventricular systolic function was disturbed either diffusely or segmentally in all patients with a mean ejection fraction of 33%. In 7 patients, echocardiography was performed shortly after furosemide therapy for New York Heart Association class IV congestive heart failure; echocardiography was also performed just before treatment in 4 of the 7 patients and LVT was not detected in any of them. Two patients died of underlying disorders within 2 months of detection of the thrombus. However, the LVT disappeared in the other 7 patients without any thromboembolic episodes during the 6 months after starting anticoagulant therapy. As fresh LVT developed shortly after diuretic therapy in patients with severe congestive heart failure associated with left ventricular systolic dysfunction, concomitant anticoagulant therapy is recommended.

Aged↗
PubMed2000

[Coronary flow after successful angioplasty in patients with acute myocardial infarction: comparison between coronary flow reserve by nicorandil and papaverine].

In order to evaluate coronary flow response to 2 different vasodilators, nicorandil and papaverine, in patients with myocardial infarction, we measured coronary flow reserve using a Doppler guide wire in infarct-related and non infarct-related arteries. The study group consisted of 28 patients with first acute myocardial infarction 3 weeks after successful coronary angioplasty within 6 hr after symptom onset. Twelve patients with atypical chest pain served as the control group. Coronary flow reserve induced by intracoronary papaverine(12 mg) was lower in infarct-related arteries than in non infarct-related arteries, but there were no differences in coronary flow reserve induced by intracoronary nicorandil(1 mg) between infarct-related and non infarct-related arteries. Coronary flow reserve induced by nicorandil was lower than that by papaverine in non infarct-related arteries and the control group. However, there were no differences between coronary flow reserve induced by nicorandil and papaverine in infarct-related arteries. Vasodilatory response induced by nicorandil was relatively preserved in infarct-related arteries compared with papaverine. These results suggest that impairment of coronary microvascular response in infarct myocardium varies in the different sites acted on by different vasodilator agents.

Angioplasty, Balloon, Coronary↗
PubMed1999

Influence of gravity on pulmonary venous flow velocity patterns: analysis of left and right pulmonary venous flow velocities in left and right decubitus positions.

BACKGROUND: The pulmonary venous flow signal measured by transesophageal echocardiography is generally recorded from the left upper pulmonary vein in the left lateral decubitus position, whereas that by transthoracic echocardiography is from the right upper pulmonary vein in the left semi-lateral decubitus position. The purpose of this study was to evaluate the influence of the postural change on the peak flow velocities of the left and right pulmonary veins and whether the parameters of the left and right pulmonary venous flow can be used interchangeably. METHODS AND RESULTS: The study group consisted of 37 patients with normal left ventricular filling pressure and in whom the systolic forward flow signals from both pulmonary veins recorded in the left and right lateral decubitus positions were clear enough to differentiate as biphasic. The peak early systolic (peak S1) and diastolic velocities were significantly increased when the pulmonary vein was on the recumbent subject's upper side, whereas the peak late systolic velocity (peak S2) was significantly increased when the pulmonary vein was on the recumbent subject's lower side. The peak S1 was higher than the peak S2 when the pulmonary vein was on the recumbent subject's upper side, whereas the reverse relation was seen when the pulmonary vein was on the recumbent subject's lower side. CONCLUSIONS: We should take into consideration the body position and the side on which the pulmonary vein is situated in evaluating the peak flow velocities of the pulmonary veins.

Adult↗
PubMed1999

Partial pressure of oxygen is lower in the left upper pulmonary vein than in the right in adults with atrial septal defect: difference in P(O2) between the right and left pulmonary veins.

BACKGROUND: The right-to-left shunt at the atrial level is responsible for arterial hypoxemia in patients with atrial septal defect. OBJECTIVES: This study investigated the mechanism of arterial hypoxemia in patients with atrial septal defect by measuring the P(O2) in both the right and left upper pulmonary veins. SUBJECTS AND METHOD: We prospectively measured the P(O2) in the femoral artery and the right and left upper pulmonary veins during cardiac catheterization in 13 adults (median age, 53 years) and 7 children (median age, 7 years) with secundum atrial septal defect. The adults and children were studied consecutively. Contrast echocardiography was performed to evaluate right-to-left shunt in all adults. RESULTS: Among the children, there were no patients showing arterial hypoxemia, and there was no difference in the P(O2) (+/-SD) between the right and left upper pulmonary veins (right, 100+/-3.8 mm Hg vs left, 100+/-7.8 mm Hg; p = 0.92). However, arterial hypoxemia was present in 11 of the 13 adult patients, although contrast echocardiography showed more than a moderate degree of right-to-left shunt in only four adults. The P(O2) was lower in the left upper pulmonary vein than it was in the right upper pulmonary vein in all adult patients (right, 91.6+/-13.8 mm Hg vs left, 73.0+/-11.5 mm Hg; p < 0.0001). CONCLUSION: The P(O2) was lower in the left upper pulmonary vein than it was in the right upper pulmonary vein in adults with atrial septal defect. Care must be taken in measuring pulmonary blood flow if the P(O2) in the left upper pulmonary vein is low enough to influence oxygen content. The decreased P(O2) in the left upper pulmonary vein may contribute to arterial hypoxemia in addition to right-to-left shunt at the atrial level in adults with atrial septal defect.

Adult↗
PubMed1998

Increased thrombin-antithrombin III complex during an episode of paroxysmal atrial fibrillation.

Thrombin-antithrombin III complex (TAT) is a marker of thrombin generation, indicating increased coagulability. To investigate whether paroxysmal atrial fibrillation (PAf) is associated with an increased coagulation system, we measured TAT within 24 h after the documentation of PAf in 50 patients with structurally normal hearts. The mean age of the study population was 62 years old. In 32 patients, PAf was documented during routine physical examinations, electrocardiograms or echocardiograms and in the remaining 18 patients, it was reproducibly documented on more than two Holter electrocardiograms. Group I consisted of 38 TAT data sets from 38 patients who did not receive anticoagulant therapy during PAf episodes. At least one week after starting anticoagulant therapy, TAT was measured again in ten patients in whom there was evidence of PAf on the day of measurement. In the remaining 12 patients, PAf occurred while the patients were receiving anticoagulation. Group II consisted of 22 TAT data sets from 22 patients who received anticoagulation during PAf episodes. The average TAT value was 5.8 ng/ml in group I, while it was 2.8 ng/ml in group II (P<0.0001). TAT was greater than 5 ng/ml in 15 of the 38 patients in group I, and in four of the 22 patients in group II. In 20 symptomatic patients, we measured TAT again when the patients maintained sinus rhythm under the same anticoagulant therapy; four patients were receiving and 16 patients were not receiving anticoagulation therapy. TAT decreased from 6.4 to 2.3 ng/ml on average when PAf disappeared and sinus rhythm was maintained (P=0.0009). Increase in the coagulation system occurred transiently during or shortly after PAf episodes in about 40% of PAf patients. As patients with prior anticoagulation had a relatively low TAT value, anticoagulant therapy might be useful in patients with PAf.

Adolescent↗
PubMed1998

Infrequent involvement of microsatellite instability in urinary bladder carcinomas of the NON/Shi mouse treated with N-butyl-N-(4-hydroxybutyl)nitrosamine.

Variation in the frequency of microsatellite instability (MSI) has been reported in different kinds of human malignant tumors, with less than one-third of invasive urinary bladder carcinoma cases estimated to be affected. Here we investigated the MSI for 27 microsatellite sequences in invasive urinary bladder carcinomas of the NON/Shi mouse induced by N-butyl-N-(4-hydroxybutyl)nitrosamine. A total of 28 urinary bladder carcinomas of both transitional cell and squamous cell types were studied. All were invasive (greater than pT3) and high-grade and 10 of them had metastasis. Only two (11%) of 18 primary bladder carcinomas without metastasis foci showed alterations in one or two loci. None of 10 pairs of urinary bladder carcinomas and metastasis foci demonstrated any alterations. In conclusion, MSI which represents a defect in the DNA mismatch repair system is infrequent and therefore unlikely to be a critical step in genesis of invasive mouse urinary bladder carcinomas.

Animals↗
PubMed1998

Aortic regurgitation in a patient with primary antiphospholipid syndrome--a case report.

We present the case of a 39-year-old woman with aortic regurgitation that may have been induced by primary antiphospholipid syndrome. The patient had suffered recurrent miscarriages, thrombocytopenia, and deep-vein thrombosis for the previous 16 years, and had been diagnosed as having primary antiphospholipid syndrome 9 years previously because of a high titer of anticardiolipin antibody. She had been receiving medication for moderate hypertension for 7 years. The patient was admitted to Tenri Hospital because of heart failure, which was thought to be caused by moderate aortic regurgitation, moderate hypertension, and mild chronic renal failure. Echocardiography revealed thickened aortic and mitral valves. Primary antiphospholipid syndrome might have induced valve regurgitation as a result of valvular thickening.

Adult↗
PubMed1998

Polymorphic ventricular tachycardia in a patient with adrenal insufficiency and hypothyroidism.

We describe a 60-year-old patient with adrenal insufficiency and hypothyroidism who experienced syncope as a result of polymorphic ventricular tachycardia associated with long QT intervals. The deep inverted T waves and long QT intervals were normalized about 8 weeks after starting steroid replacement therapy. Although there have been some reports on electrocardiographic abnormality or polymorphic ventricular tachycardia in patients with adrenal insufficiency, the pathogenesis remains unknown. Hormonal disorders should be considered as a cause of polymorphic ventricular tachycardia associated with long QT intervals, even if plasma electrolyte levels are normal, because life-threatening arrhythmia is treatable by supplementation of the hormone that is lacking.

Adrenal Insufficiency↗
PubMed1998

Two cases of hypertrophic cardiomyopathy with coronary vasospasm.

Chest pain in patients with hypertrophic cardiomyopathy seems to be caused by relative myocardial ischemia due to the left ventricular outflow pressure gradient and myocardial hypertrophy. However, in 2 cases of hypertrophic cardiomyopathy chest pain was associated with coronary vasospasm. Thus, chest pain in these cases was decreased not by a beta-blocker but by isosorbide dinitrate and a calcium antagonist. Because beta-blockers are commonly used for hypertrophic obstructive cardiomyopathy and chest pain may be aggravated by beta-blockers in patients with coronary vasospasm, a combination of beta-blocker, isosorbide dinitrate and calcium antagonist was necessary for this hypertrophic cardiomyopathy with variant angina.

Adrenergic beta-Antagonists↗
PubMed1998

Problems in pharmacological evaluation of patients with paroxysmal atrial fibrillation: clinical analysis of more than 100 consecutive patients.

To address the problems of pharmacological evaluation in paroxysmal atrial fibrillation (PAf), we interviewed 108 consecutive patients with documented PAf regarding symptoms, frequency and trigger factors of PAf and analyzed the 24-hour ambulatory electrocardiographic monitoring (Holter monitoring) records in relation to symptoms. Twenty-nine patients were totally asymptomatic, while 79 patients were symptomatic of which 49 patients had obvious trigger factors. PAf was documented by Holter monitoring in 22 of 79 symptomatic patients. On analysis of PAf-documented 25 Holter monitoring records, the patients checked event marks as PAf in only 20 of 155 PAf episodes. Six episodes of 26 event marks that patients thought to be PAf proved to be premature atrial or ventricular contractions. Nine patients in whom PAf persisted for more than 24 hours became asymptomatic. Patients suitable for pharmacological evaluation constituted about one-fifth of the PAf patients in our consecutive study. Even with the selection of these patients, pharmacological evaluation based on symptoms is difficult because disappearance of PAf may be associated with persistent atrial fibrillation.

Adolescent↗
PubMed1998

[Clinical evaluation of cholesterol embolization syndrome after cardiac catheterization].

The clinical features and outcomes of patients with cholesterol embolization syndrome after cardiac catheterization were evaluated. Among 4,920 patients undergoing cardiac catheterization during 1991 to 1996, the symptoms, signs, laboratory data, treatment and prognosis of eight (6 males and 2 females, mean age 69 years old) were reviewed who were pathologically or clinically diagnosed as having cholesterol embolization syndrome. All patients had more than two coronary risk factors. Mobile plaque of the aortic arch was detected in all five patients who underwent transesophageal echocardiography. All patients had one or more precipitating factors, including coronary angiography, percutaneous transluminal coronary angioplasty, cardiovascular surgery and cardiopulmonary resuscitation. The first symptom was renal dysfunction in four patients, skin findings of purple toes in two, muscle pain in one and new onset of refractory hypertension in one. The time after the precipitating factor to the onset of symptoms was 32 +/- 9 days on average. Eosinophilia was found in all patients and six patients revealed eosinophilia before the onset of symptoms. Four patients showed skin findings of purple toes which progressed in three of the four patients even after anticoagulant therapy was discontinued. Epidural anesthesia was markedly effective for skin findings of purple toes in two of the three patients. Diagnosis of cholesterol embolization syndrome is difficult because patients show various symptoms and there is an interval between the precipitating factor and the onset of symptoms. However, the conditions of the patients deteriorate rapidly and the prognosis is generally poor without supportive therapy in the early stage. Our study demonstrated that eosinophilia might be an important clue to early detection of cholesterol embolization syndrome. Furthermore, epidural anesthesia is effective for skin findings of purple toes in patients with cholesterol embolization syndrome. In conclusion, cholesterol embolization syndrome should be detected in the early stage based on eosinophilia or clinical symptoms after cardiac catheterization, and supportive therapy started as soon as possible, including discontinuance of anticoagulant therapy, hemodialysis for renal dysfunction and epidural anesthesia for skin findings of purple toes.

Aged↗
PubMed1998

[Hypertrophic obstructive cardiomyopathy in an elderly patient manifesting as refractory congestive heart failure of acute onset: a case report].

An 84-year-old woman was admitted to our hospital because of left heart failure of acute onset. Transthoracic echocardiography showed diffuse hypertrophy of the normal sized hyperkinetic left ventricle and chordae-like fluttering echoes attached to the mitral valve with severe mitral regurgitation signals. Mosaic flow signals were seen at the left ventricular outflow tract, but the velocity could not be measured. Emergent transesophageal echocardiography detected no obvious mitral valve prolapse. Cardiac catheterization showed greater than 100 mmHg pressure gradient between the left ventricle and femoral artery. Pressures in the femoral artery and pulmonary capillary wedge changed reciprocally in the intensive care unit; a bisferient narrow pulse pressure of the femoral artery was associated with increased v wave of the pulmonary capillary wedge pressure, and a wide pulse pressure of the femoral artery with absent v wave of the pulmonary capillary wedge pressure. Pressure monitoring in the intensive care unit, catheterization laboratory and transesophageal echocardiography were useful to understand the pathophysiology of the patient.

Aged↗
PubMed1997

Problems in the initial diagnosis of renal infarction.

We retrospectively analyzed 20 cases of renal infarction to identify the problems in tentatively diagnosing renal infarction. The subjects consisted of 12 outpatients and 8 inpatients whose diagnosis was confirmed by renal scintigram and/or contrast computed tomography. Renal infarction was tentatively diagnosed in only 4 of the 12 outpatients. Causes of hospitalization were cerebral emboli in 5 cases, peripheral emboli in the extremities in 2 cases and one case involved percutaneous transmitral commissurotomy. On initial urinalysis, 11 cases (55%) showed less than 2+ hematuria using dipsticks to test for occult blood. The mean lactic dehydrogenase value was as high as 2,096 IU while the mean aspartate aminotransferase and mean alanine aminotransferase were 83.1 IU and 78.6 IU. Abdominal ultrasonography revealed abnormalities in only one of 18 cases. In conclusion, since only a moderate degree of hematuria was seen in about half the cases and it was difficult to detect renal abnormalities by ultrasonography, a tentative diagnosis of renal infarction may be difficult in some cases.

Aged↗