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H Yamabe

Publications and source records attributed to H Yamabe.

At least 55 records · Page 3Linked to original sources

Hemodynamic characteristics during treadmill and bicycle exercise in chronic heart failure: mechanism for different responses of peak oxygen uptake.

The exercise capacity of patients with chronic heart failure (CHF) is greater when assessed by the treadmill rather than the bicycle ergometer, but the mechanism of this difference has not been clarified. The present study aimed to determine the difference between the hemodynamics of these exercise modes and the mechanism underlying the different peak oxygen uptake (VO2). Patients (n = 18) underwent a bicycle test and treadmill test using individual ramp protocols. Respiratory gas analysis and hemodynamic measurements with an opti-catheter were performed during both exercise tests. The peak VO2 was significantly larger in the treadmill test than the bicycle test (1410+/-292 vs. 1630+/-331 ml/min, p<0.001). Both the peak cardiac output (Q; 10.2+/-2.2 vs. 10.9+/-2.1 L/min, p<0.001) and the peak arteriovenous oxygen difference (a-v 02 diff; 13.9+/-1.5 vs. 15.0+/-1.2 vol%, p<0.001) were also significantly higher in the treadmill test. The relative contribution of Q and a-v O2 diff to the increased peak VO2 was equivalent, which suggests that both Q and a-v O2 diff. Contribute equally to the different peak VO2 responses in CHF.

Bicycling↗

Thrombin stimulates synthesis of type IV collagen and tissue inhibitor of metalloproteinases-1 by cultured human mesangial cells.

Glomerular accumulation of extracellular matrix (ECM) is the common pathologic feature following glomerular injury, and the alteration in the synthesis and degradation of ECM may be involved in the glomerular accumulation of ECM. Glomerular fibrin formation occurs in various forms of human and experimental glomerulonephritis, and it may play an important role in progressive glomerular injury. Thrombin, a multifunctional serine proteinase that is generated at the site of vascular injury, has central functions in hemostasis and it also shows various biologic effects. In this study, it is hypothesized that thrombin may alter the production and the degradation of type IV collagen, which is an important component of ECM in the glomeruli. Human mesangial cells (HMC) were cultured, and the levels of type IV collagen, tissue inhibitor of metalloproteinase-1 (TIMP-1), and matrix metalloproteinase-2 (MMP-2) in the culture supernatants were measured by enzyme immunoassay using specific antibodies. MMP-2 activity was also evaluated by zymography using polyacrylamide/ sodium dodecyl sulfate gel-containing gelatin. Thrombin increased the production of type IV collagen and TIMP-1 in a dose-and time-dependent manner, but it did not increase MMP-2. Thrombin also stimulated the gene expressions of the type IV collagen and TIMP-1 in HMC in a dose- and time-dependent manner. Thrombin treated with diisopropylfluorophosphate, a serine proteinase inhibitor, did not show any of these effects. Hirudin, a natural thrombin inhibitor, and anti-transforming growth factor-beta-neutralizing antibody inhibited the stimulating effect of thrombin. These findings suggest that thrombin may contribute to the excessive accumulation of ECM and progression of glomerulosclerosis through an increase of type IV collagen production and a decreased matrix degradation presumably via a transforming growth factor-beta-dependent mechanism.

Cells, Cultured↗

Prognostic factors in uterine carcinosarcoma: a clinicopathologic study of 25 patients.

BACKGROUND: Carcinosarcoma (malignant mixed mullerian tumor) of the female genital tract is a highly malignant neoplasm. The tumor stage and histologic grade of the carcinomatous component are among the important prognostic indicators cited in the literature for this tumor. METHODS: Twenty-five patients with uterine carcinosarcoma at 4 hospitals in the Kyoto and Nara areas of Japan were studied retrospectively. The clinicopathologic and immunohistochemical data including p53, bcl-2, Ki-67, and proliferating cell nuclear antigen (PCNA) staining were analyzed using univariate and multivariate analysis with the Cox proportional hazards model to investigate potential prognostic indicators for this neoplasm. RESULTS: The 5-year survival rate was 36.4% for all stages, 62.3% for Stage I, and 0% for Stages II-IV. From the univariate analysis, stage (P = 0.0001), endometrioid adenocarcinoma as a carcinomatous component (P = 0.0006), age (P = 0.0355), and a heterologous sarcomatous component (P = 0.0421) were found to be prognostically significant for patient survival. Stage was the only independent significant factor in the multivariate analysis (t = 2.212). None of the other factors (history of pregnancy and gestation, gross appearance of the tumors, grade of the carcinomatous component, mitotic count of the sarcomatous component, Ki-67 and PCNA reactivity, or p53 or bcl-2 positive staining) was found to be a significant prognostic indicator. CONCLUSIONS: Stage appears to be the only definite independent prognostic indicator of survival in patients with uterine carcinosarcoma. It is uncertain whether age, endometrioid adenocarcinoma as a carcinomatous component, or absence of a heterologous component in the sarcomatous area are prognostic factors. Immunohistochemical expression of p53, bcl-2, Ki-67, or PCNA is not a prognostic indicator. The immunohistochemical results of the current study may support the hypothesis of a common stem cell origin of this tumor.

Adult↗

Refinement of the BCL2/immunoglobulin heavy chain fusion gene in t(14;18)(q32;q21) by polymerase chain reaction amplification for long targets.

The t(14;18)(q32;q21) translocation, involving the BCL2 gene and junctional segments (JH) of the immunoglobulin heavy chain gene (IGH), constitutes the most common chromosomal translocation in non-Hodgkin's lymphoma of B-cell type. Although the breakpoints in BCL2 are largely clustered within the major breakpoint region (MBR) and minor cluster region (mcr), it is known that some breakpoints map away from these regions, resulting in negative amplification of the junctional sequence by polymerase chain reaction (PCR) for < 1 kb targets. To circumvent this problem, we applied a novel PCR technology for long DNA targets, long-distance (LD-) PCR, to the detection of t(14;18) in clinical materials. Oligonucleotide primers were designed to be quite distant from the two known cluster regions in BCL2, and those for the corresponding IGH were complementary to the enhancer and constant regions. In all 52 cases identified as carrying BCL2/JH fusion by conventional Southern blot analysis, LD-PCR successfully amplified fragments encompassing the junctions, which were readily identifiable on ethidium bromide-stained gel. The size of the LD-PCR products ranged from 3.9 kb to 10.7 kb in MBR/IGH fusion and 1.9 kb to 16 kb in mcr/IGH fusion. Furthermore, we established an LD-PCR protocol for > 20 kb targets, which covered the intervening region between the MBR and mcr. Restriction analysis of the LD-PCR products revealed that breakpoints in 33 cases fell within the 150 bp-MBR region, and in 3 cases were within the mcr determined previously by others. In contrast, the breakpoints of the remaining 16 cases were distributed over a large region from the MBR through mcr. Nucleotide sequence analysis of a potential cluster region revealed the presence of an Alu repeat sequence. Restriction analysis of LD-PCR products with BstEII demonstrated a predominant usage of the JH6 segment (71%) at the BCL2/JH junctions. LD-PCR using primers for the constant region genes showed that class switch recombination occurred in more than 80% of the IGH genes on the der(14) chromosome. Our study showed that LD-PCR was capable of detecting virtually any t(14;18) that occurred within the approximately 30 kb region downstream of the MBR, and thus is suitable for initial diagnosis of lymphoma tissues. Furthermore, as amplified fragments obtained by the LD-PCR contained distinctive regions of BCL2 and IGH, restriction analysis and nucleotide sequencing of the products refined the characteristics of t(14;18).

Base Sequence↗

Fulminant hepatic failure secondary to herpes simplex virus infection in a neonate: A case report of successful treatment with liver transplantation and perioperative acyclovir.

Neonatal disseminated herpes simplex virus (HSV) infection, including fulminant hepatic failure (FHF), is lethal, and the patients rarely have a chance for liver transplantation because of the rapid development of the disease. We describe of a case of FHF secondary to HSV infection in a neonate successfully treated by aggressive intensive care followed by liver transplantation.

Acyclovir↗

Resting 123I-BMIPP scintigraphy in diagnosis of effort angina pectoris with reference to subsets of the disease.

This study was undertaken to assess the diagnostic value of resting 123I-BMIPP scintigraphy in patients with effort angina pectoris. One hundred and four patients underwent scintigraphic and angiographic examinations. The subsets of the patients were stable effort angina pectoris (stable type) in 27 cases, new onset of effort angina pectoris (new onset type) in 21 cases, and worsening effort angina pectoris (worsening type) in 35 cases. The remaining 21 cases were subjects without evidences of coronary artery disease (non-CAD). 123I-BMIPP was injected under resting and pain free condition, then data for single photon emission tomography (SPECT) were acquired. The positive regional 123I-BMIPP defects in three coronary territories were visually judged on the tomographic images. The overall sensitivity to diagnose the patients was 62.6% (52/83) and the overall specificity to exclude non-CAD subjects was 95.2% (20/21). The detection rate in each subset of the disease was 48.1% (13/27) in stable type, 47.6% (10/21) in new onset type and 77.1% (27/35) in worsening type (p < 0.05 versus two other types). For detection of stenosed vessels, the overall sensitivity was 41.4% (56/148) and the overall specificity was 93.8% (152/164). The rate of detection of stenosed vessels was 31.7% (13/41) in stable type, 31.4% (11/35) in new onset type, and 55.6% (40/72) in worsening type (p < 0.05 versus two other types). Vessels with 75% stenosis were more sensitively detected in the worsening type (33.3%; 4/12) compared to the remaining two types (8.3%; 1/12) even though the difference was not significant. The resting 123I-BMIPP scintigraphy was therefore valuable in diagnosing patients with effort angina pectoris and involved coronary arteries especially in the subset of patients with worsening type.

Aged↗

Telomerase activity in adrenal cortical tumors and pheochromocytomas with reference to clinicopathologic features.

Telomeres consist of short repeated sequences that are shortened on continuous cell proliferations and synthesized by telomerase, an RNA-dependent DNA polymerase. Recent molecular studies have reported that telomerase is activated in most human cancers, whereas it is not detected in most somatic cells. These findings indicate that the positive telomerase activity is closely related to the malignant potential of human tumors. In several types of human tumors, including adrenal cortical tumors and pheochromocytomas, it is very difficult to predict the malignant potential using conventional histopathologic examination. To determine whether telomerase activity is useful as a diagnostic marker, we examined telomerase activity in adrenal cortical tumors and pheochromocytomas with special reference to their clinicopathologic features. Using a highly sensitive polymerase chain reaction (PCR)-based detection method, telomerase activity was demonstrated in one of 13 adrenal cortical tumors and two of seven pheochromocytomas, whereas all seven normal portions of adrenal gland failed to showed any telomerase activity. Although none of the tumors examined in this study was associated with metastasis, these three telomerase-positive tumors were accompanied by clinicopathologic features suggesting malignant potential. Telomerase activity might be a potential marker for estimating the biologic characteristics of adrenal cortical tumors and pheochromocytomas.

Adolescent↗

Heterogeneous distribution of K-ras-mutated epithelia in mucinous ovarian tumors with special reference to histopathology.

The carcinogenic process of epithelial ovarian carcinomas is still unknown, and both pathways of de novo carcinogenesis from the surface epithelium and malignant transformation of benign cystadenoma have been suggested. Especially in mucinous ovarian tumors, the transition from benign cystadenomas to tumors of low malignant potential (LMP) or carcinomas has been implicated. To elucidate this possibility, we analyzed the presence or absence of heterogeneity of the K-ras mutation corresponding to the histological heterogeneity in 71 epithelial ovarian tumors, including 31 mucinous tumors. K-ras mutation was identified in nine mucinous tumors (4 of 10 carcinomas, 4 of 14 LMP tumors, and 1 of 7 cystadenomas) and in two nonmucinous carcinomas. Microdissection of multiple sites with reference to their histological appearance showed the heterogeneous distribution of K-ras-mutated epithelia in two of the nine mucinous tumors. One mucinous carcinoma showed K-ras mutation in all of the histologically LMP and malignant portions, but not in benign portions. In another LMP tumor, all of the LMP portions and one of the benign portions showed K-ras mutation, whereas the other two benign portions had no mutation. In the remaining seven mucinous tumors with K-ras mutation, however, there was a homogeneous distribution of K-ras-mutated epithelia irrespective of their histological appearance. These findings suggest that the K-ras mutation occurs during the transformation from benign cystadenomas to LMP or malignant lesions, providing molecular genetic support for the hypothesis of the "adenoma-carcinoma sequence" in some mucinous ovarian tumors, but in other cases an alternative pathway may also be possible.

Adenocarcinoma, Mucinous↗

Absence of p53 overexpression and favorable response to cisplatin-based neoadjuvant chemotherapy in urothelial carcinomas.

It has been controversial whether cancer cells harboring loss or inactivation of the tumor suppressor p53 are resistant or sensitive to DNA-damaging agents including cisplatin and doxorubicin. Overexpression of mdm2 oncoprotein, a negative regulator of p53, is assumed to be an alternative to p53 dysfunction. Archival urothelial carcinoma specimens obtained from 60 patients prior to cisplatin-based chemotherapy were immunohistochemically studied for overexpression of p53 and mdm2. Thirty-two patients (group I) were treated with chemotherapy in the neoadjuvant setting, while 28 patients (group II) underwent chemotherapy for distant metastases or inoperable locoregional tumors. In group I, the responsiveness was correlated with staining status of p53 (P=0.0225) and the combination of p53 and mdm2 (P=0.0497). Negative staining of p53 and negative for both p53 and mdm2 could have predicted favorable response to chemotherapy in 16 of 18 (88.9%) and in 12 of 13 (92.3%) tumors, respectively. On the other hand, p53-positive and p53 and/or mdm2-positive staining could have predicted poor response only in 7 of 14 (50.0%) and 8 of 19 (42.1%) tumors, respectively. Disease-specific survival of the p53-negative group was significantly superior to that of the p53-positive group (P=0.0086). Difference in survival did not become more significant when overexpression of mdm2 was taken into consideration (P=0.0456). In contrast, in group II, there was no correlation of responsiveness to chemotherapy or survival with p53- or p53/mdm2-staining status. The patients with urothelial carcinomas negative for overexpression of p53 will benefit from neoadjuvant chemotherapy. From clinical viewpoint, however, p53 status alone or the combination of p53 and mdm2 status is not enough to identify those patients who will not benefit from the treatment.

Adult↗

Slow potential-guided radiofrequency catheter ablation in atrioventricular nodal reentrant tachycardia: characteristics of the potential associated with successful ablation.

To examine the characteristics of Haïssaguerre's slow potential (SP) specific to effective catheter ablation of the slow pathway in AV nodal reentrant tachycardia, the properties of SP and its recording site were analyzed in 52 patients who underwent successful SP-guided ablation. The properties of SP included the ratio of the amplitude of SP to that of atrial potential (A)(SP/A), the SP duration, the interval between His-bundle potential (HP) and SP (HP-SP), the interval between A and SP (A-SP), the interval between SP and ventricular potential (V) (SP-V), and the ratio of A-SP to the interval between A and the V (A-SP/A-V). The SP recording site was determined by the ratio of the amplitude of A to that of V (A/V) and by the relative position of the ablation catheter on X ray (right anterior oblique projection), expressed as the ratio of the distance between the coronary sinus ostium and SP site to that between the coronary sinus ostium and HP recording site (relative SP position). Twenty-eight slow pathways were ablated with a single energy application, while the other 24 required applications > or = 2. In all successful applications, SP/A, SP duration, HP-SP, A-SP, SP-V, A-SP/A-V, A/V, and relative SP position were 51% +/- 25%, 28 +/- 5 ms, -11 +/- 9 ms, 57 +/- 25 ms, 68 +/- 13 ms, 46% +/- 9%, 15% +/- 13%, and 51% +/- 13%, respectively. A significant correlation was observed between the relative SP position and A-SP, and between the relative SP position and A-SP/A-V (r = 0.60 and 0.37, respectively), while it was not between the relative SP position and HP-SP, nor between the relative SP position and SP-V. When the characteristics of SP were comparatively analyzed between the effective and ineffective applications in 24 patients in whom applications > or = 2 were required, there was no difference observed in HP-SP, A-SP, SP-V, A-SP/A-V, and A/V. However, SP/A, SP duration, and the relative SP position in the effective applications were all greater than those in the ineffective ones (56% +/- 20% vs 35% +/- 18%, P < 0.001; 29 +/- 4 vs 26 +/- 5 ms, P < 0.01; and 52% +/- 15% vs 33% +/- 11%, P < 0.001, respectively). These results indicate that SP with an amplitude over a half of A amplitude and recorded at the mid-septum of the tricuspid annulus can be a marker for successful slow pathway ablation. Although the local atrial electrogram appears late as the SP recording site shifts to the lower position, the timing of SP relative to HP and V remained unchanged, suggesting that SP is independent of the local atrial activation.

Action Potentials↗

Bilateral fistulas from the internal mammary arteries and the bronchial arteries to the pulmonary arteries--a case report.

A 78-year-old man was admitted to hospital with heart failure and chronic bronchitis. A computed tomographic scan of the chest incidentally demonstrated bilateral abnormal vessels near the left atrium. Selective angiography showed that both internal mammary arteries and bronchial arteries communicated with the pulmonary arteries bilaterally. The patient refused surgery and was discharged on medical therapy. This is the first reported case of bilateral fistulas between the internal mammary arteries and bronchial arteries and the pulmonary arteries.

Aged↗

Myocardial rest iodine-123-beta-methyl-iodophenyl-pentadecanoic acid scintigraphy compared with dipyridamole stress thallium-201 scintigraphy in unstable angina.

Twelve patients with stable angina and 12 patients with unstable angina underwent rest iodine-123-beta-methyl-iodophenyl-pentadecanoic acid (BMIPP), dipyridamole stress thallium scintigraphy and delayed thallium scintigraphy. In stable angina, sensitivity for detecting ischemic segments was higher in dipyridamole thallium (74%) than rest BMIPP (48%) images (p<0.05), but there was no significant difference between the 2 images in unstable angina. In unstable angina, the incidence of segments with higher defect scores on BMIPP images than on delayed thallium images and the opposite pattern was 27 and 5 (p<0.01). In stable angina, there was no difference. The mean defect score on BMIPP (6.3 +/- 5.6) was higher than that on delayed thallium scintigraphy (2.9 +/- 2.7) and it was almost the same as on the initial dipyridamole stress test (6.5 +/- 5.2). In conclusion, BMIPP scintigraphy is safer and may be as useful in detecting myocardial ischemia in patients with unstable angina as thallium scintigraphy.

Angina Pectoris↗

Dependence of peak oxygen uptake on oxygen transport capacity in chronic heart failure: comparison of graded protocol and fixed protocol.

Oxygen transport capacity is the most important determinant of maximum oxygen uptake (V(O2) max) in healthy subjects, however, its role is controversial in patients with chronic heart failure (CHF). The aim of this study was to clarify whether the oxygen transport capacity is an actual determinant of exercise capacity in CHF patients. Thirteen CHF patients underwent two maximum exercise tests, i.e., a graded protocol test and a fixed protocol test, measuring expiratory gases, leg blood flow (LBF), and arterial and venous blood gases. The workload of the fixed protocol was set to exceed the peak workload obtained by the graded protocol. Exercise with the fixed protocol caused significantly larger peak V(O2) compared to the graded protocol (813+/-194 to 971+/-203 ml/min, P<0.001). Peak LBF increased by 17%, while the peak leg arterio-venous oxygen difference increased by 5% from the graded protocol to the fixed protocol. The linear correlation between leg venous partial oxygen pressure and peak V(O2) was more clearly manifested in the fixed protocol (r=0.60, P<0.05) than in the graded protocol (r=0.47, NS). In conclusion, the exercise with graded protocol did not always conduct the upper limit of oxygen demand/supply relationship in CHF patients, whereas, the fixed protocol with a larger workload produced larger peak V(O2) and manifested the mechanism to limit V(O2) by oxygen transport capacity.

Arteries↗

Coexistence of a graft with the preserved native liver in auxiliary partial orthotopic liver transplantation from a living donor for ornithine transcarbamylase deficiency.

BACKGROUND: Auxiliary partial orthotopic liver transplantation (APOLT) has recently been performed in patients with noncirrhotic metabolic liver diseases. However, long-term outcomes for the preserved native liver and the transplanted liver graft have not been clearly established yet. METHODS: The recipient was a 36-month-old girl with ornithine transcarbamylase deficiency. She underwent APOLT, using her father's left lateral segment. RESULTS: Liver function was normalized soon after APOLT and the patient was able to ingest a normal diet without medication. Coexistence of the well-functioning native liver and graft was demonstrated in a computed tomography scan, Doppler ultrasonography, scintigraphy, and histological examination, during a relatively long-term follow-up period. CONCLUSIONS: APOLT seems to be most useful for the treatment of noncirrhotic metabolic liver diseases.

Biopsy↗

A case of Sjögren's syndrome associated with Sweet's syndrome.

We report a case of Sjögren's syndrome whose clinical course had been indolent until the patient presented with Sweet's syndrome (acute febrile neutrophilic dermatosis). This patient showed renal failure and renal tubular acidosis. Sweet's syndrome resolved within 3 weeks without corticosteroid therapy. Renal biopsy findings were consistent with interstitial nephritis. His renal manifestations responded to corticosteroid therapy and the renal function remained stable during 6 years follow-up without recurrence of Sweet's syndrome. Although close association of both syndromes is already known, in our case Sjögren's syndrome may have been exacerbated by occurrence of Sweet's syndrome.

Acute Kidney Injury↗

Impaired coronary circulation in acute myocardial infarction: a dipyridamole-thallium-201 study.

Coronary flow reserve is not fully restored immediately after revascularization of an occluded vessel. The present study examined the coronary flow impairment in patients with acute myocardial infarction (AMI) after successful balloon angioplasty or spontaneous recanalization (without residual epicardial coronary stenosis). Fourteen patients underwent thallium-201 dipyridamole scintigraphy in the acute phase (mean 5.9 days) and in the chronic phase (mean 24. 6 days) after AMI. A 201Tl reinjection study was carried out only in the acute phase of AMI. The fill-in phenomenon was assessed by the %201Tl uptake in the infarct region after 201Tl reinjection, and positive (n=8) and negative (n=6) fill-in groups were distinguished. The %201Tl uptake increased from the acute phase study to the chronic phase study in the positive fill-in group (56.1%+/-4.1% to 74.4%+/-13.6%, P<0.001), whereas it decreased in the negative fill-in group (54.0%+/-10.6% to 43.7%+/-9.9%, P<0.05). The change in %201Tl uptake following reinjection was significantly correlated with the improvement in regional ventricular wall motion in the chronic phase (r=0.85, P<0.001). We conclude that the impaired coronary flow reserve persisted after balloon angioplasty or spontaneous recanalization, which might indicate the presence of "microvascular stunning". The increase in %201Tl uptake predicted the change in ventricular wall motion.

Angioplasty, Balloon, Coronary↗

Immunohistochemical expression of nm23 gene product, nucleotide diphosphate kinase, in pancreatic neoplasms.

CONCLUSION: Our findings suggest that contrary to the proposed role for the nm23 protein as a tumor metastasis suppressor, in pancreatic tumors, the nm23 protein does not play an important role as a suppressor against tumor metastasis. BACKGROUND: The nm23 gene product, nucleotide diphosphate kinase, is believed to suppress tumor metastasis. Although a number of studies on many kinds of tumors have examined the relationship between nm23 expression and metastatic potential, the antimetastatic activity of nm23 remains controversial. The expression of the nm23 protein has not been examined in pancreatic tumors, except for a few reports on pancreatic duct cell carcinomas. METHODS: We have investigated nm23 expression in pancreatic duct cell carcinomas, islet cell tumors, and ampullary carcinomas by immunohistochemical methods. RESULTS: In 73 cases of pancreatic duct cell carcinomas, the nm23 expression was increased when compared with the adjacent normal pancreatic ducts; diffuse immunostaining was detected in 21 (29%) cases, focally positive immunostaining in 47 (64%) cases, and negative immunostaining in 5 cases (7%). All five negative samples were obtained from distant metastatic regions. However, there was no significant difference in the nm23 expression between primary tumors and regional lymph node metastases. Furthermore, there was no significant correlation between nm23 expression and the prognosis of the 55 resected cases. In the 15 cases of ampullary carcinomas, all 15 tumors were positive for nm23 protein (6 diffuse and 9 focal), and the staining intensity was stronger than in normal pancreatic ducts. There was no significant difference in the nm23 expression in the primary regions between patients with and without lymph node metastasis (2 diffuse and 5 focal out of 7 patients with lymph node metastasis, and 4 diffuse and 4 focal out of 8 patients without lymph node metastasis). All 12 islet cell tumors showed strong and diffuse staining for the nm23 protein.

Adenoma, Islet Cell↗