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Biomedical subjects

Y Kameda

Publications and source records attributed to Y Kameda.

At least 55 records · Page 3Linked to original sources

Minimally invasive direct coronary artery bypass combined with abdominal aortic aneurysm repair.

BACKGROUND: For simultaneously combined coronary artery bypass surgery with infrarenal abdominal aortic aneurysm (AAA) repair, a relatively high operative mortality and morbidity have been reported. METHODS: From February 1998 to December 1998, simultaneous minimally invasive direct coronary artery bypass combined with the AAA repair was performed for 4 patients (3 males, 1 female; mean age, 74+/-7 years). Three were high-risk patients: 2 were over 75 years of age, 2 had respiratory insufficiency, and 1 had severe renal impairment. RESULTS: There were no mortalities. The endotracheal tube was removed within approximately 12 hours, and the postoperative courses were uneventful. During 4+/-4 months of follow-up, there was neither angina recurrence nor other morbidity. CONCLUSIONS: Minimally invasive direct coronary artery bypass combined with AAA repair was safe even for high-risk patients.

Aged↗

Basement membrane patterns, gelatinase A and tissue inhibitor of metalloproteinase-2 expressions, and stromal fibrosis during the development of peripheral lung adenocarcinoma.

To clarify the process and mechanisms of the development and progression of peripheral lung adenocarcinoma, we investigated the relationships among the patterns of basement membrane (BM), stromal fibrosis, and the expressions of gelatinase A and tissue inhibitor of metalloproteinases-2 (TIMP-2) in 33 lesions of atypical alveolar cell hyperplasia (AAH) and 48 lesions of lung adenocarcinoma, including 24 lesions of bronchioloalveolar carcinoma (BAC). We found that the architecture of alveolar BM was intact in all 33 AAH lesions and 11 nonsclerosing BAC lesions that formed no central scar, suggesting that these lesions are early-stage intraepithelial neoplasia. The preexistent BM of the lung was disrupted, and the BM components around the neoplastic glands were disrupted or absent in the area of the central scar of some sclerosing BAC lesions with collapse fibrosis alone (2 of 4) and in those of all of the adenocarcinoma lesions associated with desmoplastic stromal fibrosis (nine sclerosing BAC and 24 non-BAC tumors). These results suggested that, in lung adenocarcinomas, destruction of the BM was correlated with the formation of a central scar, particularly with desmoplasia. It is likely that adenocarcinomas with a central scar are advanced and invasive cancers potentially having metastatic activity. The expression of gelatinase A and TIMP-2 was associated with central scar formation as well as with destruction of the BM components. Both the neoplastic and stromal cells expressed gelatinase A and TIMP-2 and probably play a role in tumor cell invasion.

Adenocarcinoma↗

Atypical adenomatous hyperplasia of the lung. Implications for the pathogenesis of peripheral lung adenocarcinoma.

Bronchioloalveolar lung carcinoma (BAC) exhibits many features that distinguish it from bronchogenic carcinomas. For early detection, therapy, and prevention of BAC, it is essential to understand its pathogenesis. Development of BAC appears to be stepwise, and the earliest lesion to be recognized is atypical adenomatous hyperplasia (AAH), the proliferative lesion of atypical epithelial cells along the alveolar septa. Our review of the studies of AAH revealed that certain populations of AAH cells exhibit active proliferation, aneuploidy, 3p and 9p deletions, K-ras codon 12 mutation, and disruption of the cell cycle control, but p53 gene aberrations are rare and telomerase activation is absent. We emphasize that AAH is an alveolar intraepithelial neoplasia. This allows more precise analyses of the process and mechanism of the development of BAC. Furthermore, AAH could serve as a surrogate end-point biomarker in future chemoprevention trials. The criteria for the diagnosis of AAH and related lesions should be established as early as possible.

Adenocarcinoma↗

Immunohistochemical analysis for cell proliferation-related protein expression in small cell carcinoma of the esophagus; a comparative study with small cell carcinoma of the lung and squamous cell carcinoma of the esophagus.

Small cell carcinoma is a rare neoplasm in the esophagus. To evaluate cell proliferation activity and its underlying mechanisms in this tumor, we examined immunohistochemically 5 cases of small cell carcinoma of the esophagus (SCCE) for expressions of tumor suppressor proteins, oncoproteins and cell proliferation markers including p53, p21WAF1/CIP1, retinoblastoma (Rb) protein, bcl-2, Ki-67 and PCNA, and compared the results with those of 5 cases of small cell carcinoma of the lung (SCCL) and 10 cases of squamous cell carcinoma of the esophagus (SQCE). The prevalence and labeling index of p53-immunoreactivity tended to be higher in SCCE (4/5; 56.6%) and SCCL (4/5; 79.9%) than in SQCE (6/10; 48.8%). Expression of p21WAF1/CIP1 was observed in 2 of 10 cases of SQCE. In contrast, its expression could not be detected in any cases of SCCE and SCCL examined. Expression of Rb protein was observed in 9 out of 10 cases of SQCE, but not in any cases of SCCE and SCCL. SCCE and SCCL showed more frequent and intense immunoreactivity for bcl-2 than SQCE. In expression of cell proliferation markers (Ki-67 and PCNA), no remarkable difference was observed among SCCE, SCCL and SQCE. These results suggest that SCCE and SCCL could share some genetic alternations including mutation of p53, loss of Rb gene and overexpression of bcl-2, and these may be related to the similar biological potentials between the two. Furthermore, SCCE was different from SQCE in expression of Rb protein and bcl-2, and these two types of esophageal carcinoma could arise through different molecular mechanisms.

Aged↗

Detection of noncarboxymethyllysine and carboxymethyllysine advanced glycation end products (AGE) in serum of diabetic patients.

BACKGROUND: The advanced stage of the Maillard reaction, which leads to the formation of advanced glycation end products (AGE), plays an important role in the pathogenesis of angiopathy in diabetic patients and in the aging process. N(epsilon)-(carboxymethyl)lysine (CML) is thought to be an important epitope for many of currently available AGE antibodies. However, recent findings have indicated that a major source of CML may be by pathways other than glycation. A distinction between CML and non-CML AGE may increase our understanding of AGE formation in vivo. In the present study, we prepared antibodies directed against CML and non-CML AGE. MATERIALS AND METHODS: AGE-rabbit serum albumin prepared by 4, 8, and 12 weeks of incubation with glucose was used to immunize rabbits, and a high-titer AGE-specific antiserum was obtained without affinity for the carrier protein. To separate CML and non-CML AGE antibodies, the anti-AGE antiserum was subjected to affinity chromatography on a column coupled with AGE-BSA and CML-BSA. Two different antibodies were obtained, one reacting specifically with CML and the other reacting with non-CML AGE. Circulating levels of CML and non-CML AGE were measured in 66 type 2 diabetic patients without uremia by means of the competitive ELISA. Size distribution and clearance by hemodialysis detected by non-CML AGE and CML were assessed in serum from diabetic patients on hemodialysis. RESULTS: The serum non-CML AGE level in type 2 diabetic patients was significantly correlated with the mean fasting blood glucose level over the previous 2 months (r = 0.498, p < 0.0001) or the previous 1 month (r = 0.446, p = 0. 0002) and with HbA(1c) (r = 0.375, p = 0.0019), but the CML AGE level was not correlated with these clinical parameters. The CML and non-CML AGE were detected as four peaks with apparent molecular weights of 200, 65, 1.15, and 0.85 kD. The hemodialysis treatment did not affect the high-molecular-weight protein fractions. Although the low-molecular-weight peptide fractions (absorbance at 280 nm and fluorescence) were decreased by hemodialysis, there was no difference before and after dialysis in the non-CML AGE- and CML-peptide fractions (1.15 and 0.85 kD fractions). CONCLUSIONS: We propose that both CML and non-CML AGE are present in the blood and that non-CML AGE rather than CML AGE should be more closely evaluated when investigating the pathophysiology of AGE-related diseases.

Animals↗

[Re-coronary artery bypass grafting using a MIDCAB technique in a patient with a patent RITA-LAD graft].

In a patient with a patent RITA-LAD (right internal thoracic artery-left anterior descending artery) graft, re-CABG (re-coronary artery bypass grafting) with re-median sternotomy has been a high risk procedure. A 56-year-old male underwent 4-CABG (RITA-LAD, LITA-Dx, SVG-PL, and SVG-RCA) nine years ago. Coronary angiography showed that the RITA-LAD graft was well patent, but there was 95% stenosis distal to RITA-LAD anastomosis site. We performed re-CABG (right gastroepiploic artery-LAD; RGEA-LAD), using MIDCAB (minimally invasive direct coronary artery bypass) technique with neither re-median sternotomy nor cardiopulmonary bypass. The right gastroepiploic artery was harvested through a small upper median laparotomy and anastomosed to LAD through a small left anterior thoracotomy. The postoperative course was uneventful. This technique seems to be useful for re-revascularization of the LAD in a patient with a patent RITA-LAD graft.

Coronary Artery Bypass↗

Substance P- and CGRP-immunoreactive fibers in the chicken carotid bodies after nodose ganglionectomy and midcervical vagotomy.

The chicken carotid body is richly innervated by branches from the vagus nerve immunostained with the monoclonal antibody TuJ1 to neuron-specific class III beta-tubulin. Furthermore, peptidergic nerve fibers are densely distributed in and around the carotid body. After transection of the vagus nerve proximal to the nodose ganglion, TuJ1-immunoreactive fibers did not change in density but substance P- and CGRP-immunoreactive fibers were conspicuously decreased in and around the carotid body. After removal of the nodose ganglion, TuJ1-immunoreactive fibers markedly diminished and substance P- and CGRP-immunoreactive fibers almost disappeared. These results indicate that the vast majority of substance P- and CGRP-immunoreactive fibers in the chicken carotid body originate from the vagal ganglia.

Animals↗

Different effects of prolonged isocapnic hypoxia on the carotid body and the glomus cells in the wall of the common carotid artery of the chicken.

In the chicken, glomus cells are widely distributed not only in the carotid body but also in the wall of the common carotid artery and around each artery arising from the common carotid artery. Effects of chronic isocapnic hypoxia on the chicken carotid body and the glomus cells in and around the arteries were examined by immunohistochemistry and electron microscopy. In chickens exposed to isocapnic hypoxia for 35 days, three- to four-fold increase of the carotid body volume was induced. Immunoreactivity for tyrosine hydroxylase of glomus cells almost completely disappeared. Dense networks of TuJ1-immunoreactive nerve fibers were unchanged, whereas peptidergic nerve fibers, i.e., substance P-, calcitonin gene-related peptide-, vasoactive intestinal peptide-, galanin- and neuropeptide Y-immunoreactive fibers, were decreased in and around the carotid body. At the electron microscopic level, increased secretory activity of the glomus cells was verified. Mature dense-cored vesicles were markedly decreased, although prosecretory granules were numerous around Golgi complexes. Many immature glomus cells filled with rough endoplasmic reticulum and free ribosomes, also appeared in the carotid bodies of hypoxic chickens. In contrast to the carotid body, the glomus cells located in the wall of the common carotid artery revealed no changes after long-term hypoxia. The cells in the hypoxic chickens, as well as normal controls, expressed intense immunoreactivity for neuropeptide Y, serotonin and chromogranin A. Furthermore, a large number of dense-cored vesicles were distributed throughout the cytoplasm. The glomus cells around each artery arising from the common carotid artery were affected by hypoxia, although the degree of their response to hypoxia varied depending on the locations.

Animals↗

Long-term benefits of internal thoracic artery-coronary artery bypass in Japanese patients.

OBJECTIVES: This study sought to determine the effects of grafting the internal thoracic artery (ITA) to the left anterior descending coronary artery (LAD) on long-term (10-year) survival, the cardiac death-free rate, and on the cardiac event-free rate in Japanese patients. BACKGROUND: The use of ITA grafts has been reported to enhance postoperative survival and to decrease the occurrence of cardiac events in the Western literature. However, the survival benefits in Japanese patients, who may have different prognoses with coronary artery disease and a different fate of a saphenous vein graft, have not yet been determined. SUBJECTS AND METHODS: A total of 954 consecutive patients who underwent coronary artery bypass graft operations (CABG) during the last 12 years at the Nara Medical University were followed and evaluated. Of these, 713 patients underwent ITA-CABG to at least the LAD (ITA group), and 241 patients received a saphenous vein graft (SVG) to the LAD (SVG group). At the time of operation, no significant difference was found between these two groups in age, sex ratio left ventricular ejection fraction, left ventricular end-diastolic pressure, cardiac index, incidence of unstable angina, or in the necessity for an emergency operation. However, those patients who received ITA-CABG had significantly higher incidences of diabetes mellitus, hyperlipidemia, and left main coronary artery disease. RESULTS: The 10-year cumulative graft patency rate for the LAD was 23% higher in the ITA group (90.3%) compared to the SVG group (67.0%), (p < .0001). Despite increased preoperative risk factors, patients in the ITA group showed significant improvements in their 5- and 10-year cumulative survival rates as well as in their cardiac death-free and event-free rates. Furthermore, this study demonstrated that ITA grafts improved the prognoses of patients with diabetes mellitus or left ventricular dysfunction and lowered both the long-term postoperative cardiac-death rate and the cardiac-event rate. CONCLUSIONS: The use of ITA grafts was effective in improving both the postoperative survival and cardiac event-free rates, and should be recommended in patients with diabetes mellitus or left ventricular dysfunction. ITA grafting to the LAD should be a routine operation in almost all categories of such patients.

Aged↗

Localization and development of chromogranin A and luteinizing hormone immunoreactivities in the secretory-specific cells of the hypophyseal pars tuberalis of the chicken.

The pars tuberalis mainly consists of the secretory cells specific to this portion of the pituitary. We examined the localization and development of luteinizing hormone (LH) and chromogranin A in the chicken pars tuberalis by immunohistochemistry. The vast majority of the chicken pars tuberalis was occupied by cells immunoreactive for both LH and chromogranin A. Furthermore, immunoblot analysis of chicken pars tuberalis extracts with LH antiserum demonstrated that two bands, the large alpha-subunit and small beta-subunit of the LH molecule, were expressed in this tissue as well as in the pars distalis. A band for chromogranin A was also detected in pars tuberalis extracts with chromogranin A antiserum. In contrast to the cells of mammalian species that contain only a few small secretory granules, the specific cells of the chicken pars tuberalis were characterized by the presence of many secretory granules ranging from 90 to 400 nm in diameter. Postembedding immunogold labeling showed that gold particles representing immunoreactivity for LH were densely located on all secretory granules of the secretory-specific cells. Many secretory granules, especially the large ones, of the cells were also loaded with immunogold particles for chromogranin A. Double immunogold labeling confirmed that LH and chromogranin A were colocalized on the same secretory granules. During embryonic development, the primordium of the pars tuberalis was first detected at 8 days of incubation as a small group of cells containing LH- and chromogranin-immunoreactive cells. In the pars distalis, the onset of LH and chromogranin expression occurred earlier, at 6 days of incubation. At 10 days of incubation, the pars tuberalis primordium became large cell masses consisting of LH- and chromogranin-immunoreactive cells, which were located close to the median eminence. Subsequently, the primordium extended along the median eminence progressively with age. At 14 days of incubation, it reached to the rostral end and surrounded the median eminence as slender cell cords. These results indicate that specific cells of the chicken pars tuberalis synthesize a glycoprotein hormone related to the LH molecule, which is stored in the secretory granules together with chromogranin A. The pars tuberalis may be involved in the regulation of gonadal function in a different way from that of the pars distalis.

Animals↗

Expression of cyclin D1, retinoblastoma gene protein, and p16 MTS1 protein in atypical adenomatous hyperplasia and adenocarcinoma of the lung. An immunohistochemical analysis.

To clarify the events leading to the disruption of cell growth control that occurs during the development of pulmonary adenocarcinoma (AC), we used immunohistochemistry to evaluate the expression of G1 cycle regulators, cyclin D1, Rb protein (pRb), and p16 MTS1 protein and the tumour proliferation marker, Ki 67, both in AC of the lung and in its precursor lesion, atypical adenomatous hyperplasia (AAH). The frequency of lesions with cyclin D1 overexpression was relatively high in AAH (47-89%), but was decreased in early AC (28%) and overt AC (35%). The loss of pRb expression was rare in both AAH (0-18%) and early AC (0%), and was infrequent even in overt AC (13%). The loss of p16 expression was also relatively infrequent in both the premalignant and the malignant lesions (11-25%). Our results suggest that overexpression of cyclin D1 is an early event and plays an important part in tumorigenesis in the case of lung AC. However, cyclin D1 overexpression is not required for the development and maintenance of a malignant phenotype. It is likely that some cyclin D1-independent pathways other than Rb and p16 abnormalities have an important role in the malignant transformation from AAH to early AC.

Adenocarcinoma↗

Difference in acetylcholine-induced nitric oxide release of arterial and venous grafts in patients after coronary bypass operations.

OBJECTIVES: In vivo investigation of nitric oxide release in coronary bypass grafts has not been reported. We studied acetylcholine-induced nitric oxide release in vivo of coronary bypass grafts and vasomotor responses to acetylcholine of grafted coronary arteries in patients after coronary bypass grafting. METHODS: We examined 24 internal thoracic artery grafts and 16 saphenous vein grafts in 39 patients. The mean ages of the patients were 65 years for the arterial grafts and 68 years for the venous grafts. Nitric oxide was measured as the plasma nitrite level by the Griess reaction. Before and after intragraft acetylcholine infusion (5 microg), blood was sampled from the distal end of the graft, and angiograms were taken and analyzed by cine-densitometry. RESULTS: The plasma nitrite concentration after stimulation with acetylcholine compared with the control value was 134%+/-52% at 4 minutes (p=0.05) and 184%+/-107% at 6 minutes (p=0.01) in the arterial grafts; in the venous grafts these values were 101%+/-24% at 4 minutes (p=0.96) and 108%+/-36% at 6 minutes (p=0.69). Low-dose acetylcholine dilated the coronary arteries supplied by arterial grafts by 6.3%+/-16.6% whereas coronary arteries supplied by venous grafts were reduced by 9.8%+/-11.8% in diameter and the vasoactive responses were different (p=0.01). CONCLUSIONS: In vivo internal thoracic artery grafts had more endothelium-derived nitric oxide release in response to acetylcholine than did saphenous vein grafts after coronary bypass grafting.

Acetylcholine↗

Nitrogen-containing furanose and pyranose analogues from Hyacinthus orientalis.

Aqueous methanol extracts from the bulbs of Hyacinthusorientalis were subjected to various ion-exchange column chromatographic steps to give 2(R),5(R)-bis(hydroxymethyl)-3(R),4(R)-dihydroxypyrrolidine (DMDP) (1), 2,5-dideoxy-2,5-imino-dl-glycero-d-manno-heptitol (homoDMDP) (2), 2,5-imino-2,5,6-trideoxy-d-manno-heptitol (6-deoxy-homoDMDP) (3), 2,5-imino-2,5,6-trideoxy-d-gulo-heptitol (4), 1-deoxynojirimycin (5), 1-deoxymannojirimycin (6), alpha-homonojirimycin (7), beta-homonojirimycin (8), alpha-homomannojirimycin (9), beta-homomannojirimycin (10), and 7-O-beta-d-glucopyranosyl-alpha-homonojirimycin (MDL 25,637) (11). The structures of the new natural products 3 and 4 were determined by spectroscopic analysis, including extensive 1D and 2D NMR studies. Compound 2 was found to be a potent inhibitor of bacterial beta-glucosidase, mammalian beta-galactosidases, and mammalian trehalases, while 3 was a potent inhibitor of rice alpha-glucosidase and rat intestinal maltase. Compound 4 was observed to be a good inhibitor of alpha-l-fucosidase.

Alkaloids↗

Effect of 26,26,26,27,27,27-Hexafluoro-1,25-dihydroxyvitamin D3 on the expression of vitamin-D-responsive genes in vitamin-D-deficient mice.

26,26,26,27,27,27-Hexafluoro-1,25-dihydroxyvitamin D3 (ST-630) is a newly developed agent to maintain the levels of calcium and phosphorus in blood. Herein, we investigated the effect of this compound on the expression of vitamin-D-responsive genes in vitamin-D-deficient mice. ST-630 was more effective than 1, 25-dihydroxyvitamin D3 [1,25(OH)2D3] with respect to the induction of Cyp24 and calbindin-D9k mRNAs in the kidney and in the small intestine. Moreover, the increase in mRNA levels of vitamin-D-responsive genes induced by ST-630 lasted longer than that induced by 1,25(OH)2D3. These results indicate that ST-630 was more effective in inducing Cyp24 and calbindin-D9k gene expression than 1, 25(OH)2D3 when both compounds were injected into vitamin-D-deficient mice.

Animals↗

Impact of percutaneous transluminal coronary angioplasty on coronary bypass surgery--changes in the patient profile during the past decade.

As percutaneous transluminal coronary angioplasty has become an increasingly common procedure replacing coronary artery bypass grafting (CABG), the clinical profile of the patients referred for CABG has changed markedly. A retrospective study of the changes in the clinical profile and surgical outcome of patients who underwent CABG during the past 10 years was conducted. Between March 1982 and February 1996, 1010 patients underwent isolated CABG at Nara Medical University. The first 100 consecutive patients who underwent CABG in 1984-85 (group 1) were compared with the first 100 consecutive patients who underwent CABG in 1994-95 (group 2). Preoperative risk increased significantly during the decade with respect to patient age (p<0.001), the presence of diabetes mellitus (p=0.048), the number of diseased vessels (p<0.001), left main trunk disease (p=0.008), the presence of aortic or peripheral vascular disease (p=0.032),and the need for emergency surgery (p=0.013). Operative procedures have become more complicated with respect to the number of total and arterial grafts, duration of the aortic cross-clamp and cardiopulmonary bypass. Hospital mortality for elective CABG has not changed (2%) and the overall mortality has not increased significantly (from 2% to 3%) during the decade. In conclusion, although the preoperative risks have increased and more complicated procedures are required, CABG continues to be performed safely with low mortality rates.

Aged↗

[Effectiveness of surgical repair of mitral regurgitation concomitant with dilated cardiomyopathy].

Dilated cardiomyopathy (DCM) is often accompanied by severe mitral regurgitation (MR) which deteriorates the clinical course. Mitral reconstruction for severe MR may improve the symptoms and prognosis. Five patients with DCM and one patient with dilated phase of hypertrophic cardiomyopathy underwent mitral reconstruction for severe MR (4 males, 2 females, mean age 50 +/- 17 years) from 1983 to 1995. Their New York Heart Association (NYHA) functional class and findings of echocardiography and cardiac catheterization were compared before and after surgery. Five patients underwent annuloplasty and one patient underwent mechanical valve replacement. There was no operative or in-hospital death. NYHA class improved from 3.2 to 1.8 (p < 0.05). The degree of MR was reduced from 3.5 to 1.2 (p < 0.05), and left ventricular end-diastolic pressure decreased from 18 +/- 7 to 13 +/- 8 mmHg (p < 0.05). Left ventricular fractional shortening, ejection fraction and cardiac index (2.4 +/- 0.4 to 2.7 +/- 1.1 l/min/m2) did not change significantly. Two patients died within one year due to exacerbation of congestive heart failure (2.5 month later) or sudden death (6 months later). Three patients died at 21 months, 5 and 8 years after the operation (renal insufficiency, heart failure, sudden death, respectively). Mitral reconstruction improved the symptoms in patients with DCM and severe MR in the short term. However, 5 of 6 patients died in the intermediate or long-term. Mitral reconstruction may be a therapeutic option for early outcome in patients with refractory congestive heart failure due to DCM and severe MR.

Adult↗

Preparation and biological activity of manno- and galacto-validamines, new 5a-carba-glycosylamines as alpha-glycosidase inhibitors.

Manno- and galacto-validamines, which are epimers of validamine, were semi-synthesized by the configurational inversion of validamine, a pseudo-sugar analogue of alpha-D-gluco-pyranose that has inhibitory activity for alpha-glucosidases. The inhibitory activities of these analogues were determined against several mannosidases and galactosidase. Manno-validamine shows potent inhibition for the alpha-mannosidases (competitive. K(i) = 4.6 x 10(-5) M for jack beans, and competitive, Ki = 2.8 x 10(-5) M for almonds), and galacto-validamine shows weak inhibition for the alpha-galactosidases (coffee bean and E. coli). The inhibitory effect of the epimers on the N-linked oligosaccharide-processing mannosidases involved in glycoprotein biosynthesis and lysosomal mannosidase from rat liver were also examined. Mannovalidamine shows potent inhibition on the endoplasmic reticulumal alpha-mannosidase (competitive, K(i) = 1.2 x 10(-6) M), Golgi mannosidases IA, II (competitive, K(i) = 2.8 x 10(-5) M), and lysosomal alpha-mannosidase (competitive, Ki = 1.7 x 10(-5) M).

Animals↗