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Y Kameda

Publications and source records attributed to Y Kameda.

At least 73 records · Page 4Linked to original sources
PubMed1997

Molecular cloning and characterization of a novel putative STE20-like kinase in guinea pigs.

Protein kinases play a key role in cell growth and differentiation. We have isolated the cDNA of a novel protein serine/threonine kinase (referred to as STE20-like kinase (SLK) from a guinea pig liver cDNA library with a probe generated by a cloning approach based on the polymerase chain reaction. The encoded polypeptide (1231 amino acids, M(r) 141,079) contains all conserved subdomains characteristic of the protein serine threonine kinase family. A hemagglutinin-tagged SLK expressed artificially in COS7 cells was hyperphosphorylated by anisomycin. By Northern blot analysis, SLK mRNA was detected in all organs examined: brain, lung heart, liver, kidney, spleen, testis, and eosinophils. Sequence comparisons of its catalytic domain related SLK to p21-activated kinase family of protein serine/threonine kinases. Its noncatalytic domain comprises several intriguing structural features, including the acidic region and the nuclear targeting sequence. This noncatalytic domain exhibited no extended similarity with other proteins. Thus, SLK is a protein serine/threonine kinase which contains an unknown regulatory domain(s).

Amino Acid Sequence↗
PubMed1997

Cytodifferentiation of atypical adenomatous hyperplasia and bronchioloalveolar lung carcinoma: immunohistochemical and ultrastructural studies.

We used immunohistochemistry and electron microscopy to evaluate the differentiation of cells comprising atypical adenomatous hyperplasia (AAH; n = 26), early bronchioloalveolar lung carcinoma (BAC; n = 11), and overt BAC (n = 16), which are assumed to constitute a continuous spectrum of developmental steps of BAC. Surfactant apoprotein (SAP), a marker for type 2 alveolar cells, was expressed in cells from all the lesions of AAH, early BAC, and overt BAC. However, the proportion of SAP-positive cells decreased and their distribution became more heterogeneous with advancing lesion grade. Urine protein 1, which is identical to the Clara cell-specific 10 kDa protein, was expressed in 70% of overt BAC, whereas only 20% of early BAC showed weak reactivity and none of AAH lesions showed any reactivity at all. Ultrastructurally, type 2 alveolar cell differentiation was predominant among cells from AAH and early BAC. Our results suggest that precursor cells of BAC differentiate predominantly towards type 2 alveolar cells. Cells comprising overt BAC retain this differentiation phenotype, but to a reduced extent. In contrast, concomitantly with progression, cells with Clara cell differentiation emerge and their proportion increases. Such phenotypic changes may reflect metaplasia occurring in tumour cells during the development of BAC.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1997

Comparative rest and exercise hemodynamics of allograft and prosthetic valves in the aortic position.

BACKGROUND: Allograft aortic valve replacement has gained widespread acceptance. However, there is little information about in vivo allograft valve function at rest and during exercise. METHODS: Cardiac catheterization was performed to measure hemodynamic variables at rest and during supine bicycle exercise in 44 patients who had had aortic valve replacement using allograft valves or Bicer or St. Jude Medical prosthetic valves 19 to 27 mm in diameter. Sixteen patients received an allograft valve; 17, a Bicer valve; and 11, a St. Jude Medical valve. There were no significant differences between the three groups in age, body surface area, left ventricular end-systolic and end-diastolic volume indices, exercise cardiac index, exercise heart rate, or work load achieved. Left ventricular and ascending aortic pressures were measured simultaneously according to the transseptal method. RESULTS: The mean pressure gradient was generally higher for the Bicer and St. Jude Medical valves than for the allograft valves, both at rest and during exercise. Significant differences were obtained in patients with small-sized valves (21 and 23 mm); pressure gradients were higher in the prosthetic valve groups. In patients with large-sized prosthetic valves (25 mm), there were no significant differences between the three groups at rest and during exercise. However, there was no pressure gradient at all for allograft valves. CONCLUSIONS: Exercise cardiac catheterization confirms that the allograft aortic valve is an ideal substitute from the hemodynamic aspect, particularly in patients with a small aortic root and in those who perform strenuous exercise.

Aortic Valve↗
PubMed1997

Laparoscopic prediction of hepatocellular carcinoma in cirrhosis patients.

Previously, laparoscopic studies have not been successful in predicting the occurrence of small hepatocellular carcinoma because cirrhotic patients had not been separated into groups of those who developed small hepatocellular carcinoma under 3 cm in diameter, and those who did not. Retrospective examination with better separation of the two groups gave improved results. Of the 26 laparoscopic findings, only the presence of large complex regenerative nodules was closely associated with the occurrence of subclinical small hepatocellular carcinoma. The study of other cirrhotic patients with and without large complex regenerative nodules gave a cumulative hepatocellular carcinoma occurrence rate of 73% for patients who had these nodules by the third year after laparoscopy. In contrast, the rate for patients without such nodules was 6%, showing a significant difference (P < 0.05) between the two groups. We concluded that the laparoscopic finding of large complex regenerative nodules of liver cirrhosis can be used to predict the occurrence, or a complication, of subclinical small hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1997

[CT-guided localization for thoracoscopic pulmonary wedge resection].

Recently the identification of small-sized peripheral lung lesions has rapidly increased due to advancements in roentgenology. But for smaller lesions, definitive diagnoses by means of transbronchial or percutaneous biopsy have become more difficult. So we must resort to thoractomic or thoracoscopic biopsy. However, for thoracoscopic surgery palpation is inadequate, so the identification of deep or small lesions is difficult. Thoracotomy seems to be too invasive when used only for examination and not for therapy. Therefore, we tried CT-guided localization for thoracoscopic pulmonary wedge resection. Thus far we have performed CT-guided localization in 24 cases. Immediately prior to thoracoscopic surgery we placed marking devices in or beside the lesions after percutaneous puncture. As marking devices we used Kopans spring hook wire or a Naruke point marker. Pathological diagnoses of these lesions indicated 13 primary lung cancers (11 adenocarcinomas, 1 carcinoid, 1 squamous cell carcinoma), 4 focal fibroses, 2 metastases of renal cell carcinoma, 1 hamartoma, 1 tuberculoma, 1 cryptococcosis, 1 interstitial pneumonia, and 1 subpleural lymph node. The tumor diameters at their greatest dimension ranged from 3 to 33 mm (9.0 +/- 6.6 mm). The distance from the viceral pleura to the tumor surface ranged from 0 to 24 mm (10.9 +/- 6.7 mm). In one case pneumothorax occurred due to the shallow position of the tumor and the loss of the marking device. If these problems (pneumothorax, bleeding, loss of marking devices and others) are prevented, CT-guided localization should be performed as soon as possible before surgery. The identification of small peripheral lesions can almost be determined by CT now, so such identification may be the most reliable technique to employ during surgery.

Endoscopy↗
PubMed1997

Analysis of p21Waf1/Cip1 expression in normal, premalignant, and malignant cells during the development of human lung adenocarcinoma.

Our studies suggested that adenocarcinoma of the peripheral lung mostly develops by several steps from atypical adenomatous hyperplasia through early adenocarcinoma to overt adenocarcinoma, and that some p53 abnormalities play an important role in this progression. In the present study, we examined by immunohistochemistry the expression of p53-inducible cyclin-dependent kinase inhibitor p21Waf1/Cip1 (p21) in the cells at various developmental stages of lung adenocarcinoma (32 lesions of adenomatous hyperplasia, 14 of early adenocarcinoma, 23 of well differentiated adenocarcinoma, and 17 of moderately or poorly differentiated adenocarcinoma) in comparison with 19 reactive proliferative lesions and analyzed the relationship between p53 and p21 expression. Bronchioalveolar cells in the normal lung expressed very little or no p21 and no p53 expression. In not only reactive but also neoplastic lesions regardless of their developmental stage, the cells expressed p21 at various frequencies. The average labeling indices ranged from 5.4 to 13.8%, and there was no significant difference between any of these categories. The expression of p21, however, tended to be relatively low in moderately and poorly differentiated adenocarcinomas (5.5%) compared to well differentiated adenocarcinomas (12.2%), and high-level p21 expressors (10% < or = positive cells) were more frequent in the latter group (1 of 17 (6%) versus 3 of 23 (35%), P < 0.05), suggesting that p21 expression is affected by the degree of differentiation of the neoplastic cells. Although the correlation was positive between the expression of p21 and p53 in reactive lesions (r = 0.88; P < 0.001), none was found in neoplastic lesions at any step or grade (-0.12 < or = r < or = 0.26). These results indicated that p21 expression depends upon p53 expression in reactive lung cells, whereas p21 expression is at least in part independent of that of p53 from the earliest to the most fully developed step of lung adenocarcinoma tumorigenesis. We concluded that disruption of the p53-dependent cell cycle regulation is a very early event in the tumorigenesis of lung adenocarcinoma.

Adenocarcinoma↗
PubMed1997

[Coronary artery bypass grafting in patients over 70 years old].

We examined the outcome of CABG in 157 patients aged over 70 years. The average age was 72.7 +/- 2.4 years: the number of the diseased vessels, 2.5 +/- 0.7/pt; the mean preoperative LVEF, 0.55 +/- 0.17 and the number of patients with left main trunk disease, 40 (26%). The mean number of bypass grafts was 2.8 +/- 0.8/pt. In 131 patients (83.4), left internal thoracic artery (LITA) was used to bypass the left anterior descending artery (LAD). The postoperative hospital mortality rate was 6.4%. After 10 years of follow-up, the actuarial survival rate and cardiac event-free rate were 73.6% and 88.9%, respectively calculated by the Kaplan-Meier method. A comparison of the long-term results of CABG with and without ITA grafting, showed no statistical difference with respect to actuarial survival rate. However, the cardiac event-free rate was improved by using an ITA graft (92.4% with an ITA vs 77.3% without an ITA, p = 0.047). This result suggested that the use of ITA in patients over 70 years old reduced the incidence of postoperative cardiac events without increasing the operative risk.

Age Factors↗
PubMed1997

Increased risk of coronary artery bypass grafting for left ventricular dysfunction with dilated left ventricle.

UNLABELLED: The operative mortality and morbidity in patients with severe left ventricular dysfunction who undergo coronary artery bypass grafting (CABG) remain high. The low ejection fraction is the major risk factor for operative mortality. However, ejection fraction (EF) alone may not necessarily be an accurate predictor of operative mortality. We studied the correlation between indices of left ventricular volume and operative mortality. One thousand patients undergoing isolated coronary bypass operations were divided into three groups according to their preoperative ejection fraction. Fifty patients (group I) had severe left ventricular dysfunction (EF < or = 0.3), 56 patients (group II) had moderately left ventricular dysfunction (0.3 < EF < or = 0.4) and 894 patients (group III) had good left ventricular function (EF > 0.4). We analyzed the relationship between hospital mortality and left ventricular volume in 106 patients with an EF < or = 0.4. RESULTS: Cardiac index was not significantly different among the three groups. The left ventricular end-diastolic pressure (LVEDP) and mean pulmonary artery pressure in groups I an II were higher than those in group III. The left ventricular end-diastolic volume (LVEDV) was 146 +/- 44 ml/m2 in Group I, 112 +/- 31 ml/m2 in Group II and 82 + 30 ml/m2 in Group III, respectively (Group I versus II, p < 0.05, Group I and II versus III, p < 0.01). The left ventricular end-systolic volume (LVESV) was 111 +/- 38 ml/m2 in Group I, 72 +/- 21 ml/m2 in Group II and 30 +/- 14 ml/m2 in Group III, respectively (Group I versus II, p < 0.05, Group I and II versus III, p < 0.01). The LVEDV and LVESV were higher in Group I than in Group II and both in Groups I and II were higher than in Group III. The hospital mortality of any cause before discharge was 8.0% (4/50) in Group I, 3.6% (2/56) in Group II, and 2.0% (18/894) in Group III. The mortality in Group I was higher than that in Group III, but the mortality between Groups I and II was not different. We assessed correlations between large left ventricle with left ventricular dysfunction and operative mortality in 106 patients with ejection fractions of < or = 0.4. The hospital mortality in patients with both under fraction 0.4 and an LVESV > or = 140 ml/m2 was 50% (4/8). This rate was higher than in patients with an LVESV between 80 and 140 ml/m2 (1.8%, 1/55) (p = 0.0006) and an LVESV less than 80 ml/m2 (2.3%, 1/43), (p = 0.0013). The hospital mortality in patients with an LVEDV > or = 200 ml/m2 was 67% (4/6). It was also higher than that in patients with an LVEDV between 200 and 120 ml/m2 (1.7%, 1/58), (p = 0.0001), and an LVEDV less than 120 ml/m2 (2.4%, 1/42), (p = 0.0004). We conclude that patients with a low ejection fraction and an elevated LVESV or LVEDV are at increased risk for hospital death following CABG.

Cardiac Volume↗
PubMed1996

Annuloplasty for severe mitral regurgitation due to dilated cardiomyopathy.

We present a 74-year-old woman who underwent corrective annuloplasty for severe mitral regurgitation due to dilated cardiomyopathy. Postoperatively, congestive heart failure improved, with her New York Heart Association status changing from IV to II, although her cardiac functional improvement was minimal. Severe mitral regurgitation may be the indication for annuloplasty in symptomatic patients with dilated cardiomyopathy when cardiac transplantation is not indicated.

Aged↗
PubMed1996

Atypical adenomatous hyperplasia and bronchoalveolar lung carcinoma. Analysis by morphometry and the expressions of p53 and carcinoembryonic antigen.

Atypical adenomatous hyperplasia (AAH) of the lung is a putative precursor of bronchoalveolar carcinoma (BAC). To define the steps in its development and to clarify at which stage critical cellular events occur, we studied 65 lesions of AAH, early BAC, and overt BAC by morphometric analysis and immunohistochemical evaluation of expression of p53 protein and carcinoembryonic antigen (CEA). Both the nuclear area and lesion size increased from AAH to early BAC and to overt BAC; the standardized variation of nuclear area was smallest in overt BAC. Discriminant analysis using these morphometric parameters revealed high accuracy rates for the respective categories. Analysis of distribution of lung lesions in terms of nuclear area and lesion size yielded effective, potentially diagnostic cutoff values for distinction between AAH and early BAC. Both p53 and CEA expression tended to increase with the advance of atypia grade. In particular, high-level p53 expression was strongly correlated with overt BAC. These findings indicate that our classification of lung lesions is reproducible and thus useful for analyzing the development of BAC. Furthermore, some kinds of p53 gene abnormalities that are correlated with high-level p53 expression likely play an important role in the progression of early to overt BAC.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1996

Immunoexpression of the alpha subunit of a guanine nucleotide-binding protein (Go) in pulmonary neuroendocrine cells and neoplasms.

The alpha subunit of a GTP-binding protein, Go, was investigated in pulmonary neuroendocrine neoplasms and fetal tissues of the lung by an immunohistochemical method. Positive immunostaining for the alpha subunit of Go (Go alpha) was found predominantly on the cell membrane and found occasionally in the cytoplasm. Typical carcinoids were all positively stained (9/9), and small cell carcinoma showed weaker and less frequent staining (5 positive cases in 10). Atypical carcinoids were variously stained (3/4). The tendency for obvious neuroendocrine differentiation to be immunohistochemically determined in typical carcinoids and not in small cell carcinoma is also true of staining for neuron specific enolase (NSE), chromogranin A (CG-A) and synaptophysin. In the lung, Go alpha-immunostaining was positive not only in nerve tissues but also in the airway epithelium. In the fetal lung, serial sections immunostained for NSE, CG-A and Go alpha confirmed that Go alpha-immunoreactive cells belong to the neuroendocrine cell population. The biological significance of Go alpha is unclear in normal and neoplastic lung tissues, but Go alpha is a useful marker of neuroendocrine cells and neoplasma of the lung.

Adult↗
PubMed1996

Immunoelectron microscopic localization of vimentin in sustentacular cells of the carotid body and the adrenal medulla of guinea pigs.

The sustentacular cells of the carotid body and the adrenal medulla of guinea pigs were studied by light and electron microscopic immunohistochemistry and compared with the Schwann or satellite cells of the peripheral nervous system. In the peripheral nervous system, neurons were immunoreactive for protein gene product (PGP) 9.5, whereas Schwann cells or satellite cells were immunoreactive for S-100 protein and vimentin. Vimentin immunoreactivity was detected on the intermediate filaments of the Schwann cells by post-embedding immunogold labeling. In the carotid body and the adrenal medulla, glomus cells or chromaffin cells were dosely enveloped by the sustentacular cells, which protruded long cytoplasmic processes and had some axons embedded in them, as in Schwann cells. The glomus cells or chromaffin cells expressed immunoreactivity for PGP 9.5, whereas the sustentacular cells expressed immunoreactivity for S-100 protein and vimentin. The sustentacular cells were characterized by the presence of abundant intermediate filaments on which immunogold particles for vimentin were densely located. From these results, it is concluded that the sustentacular cells closely resemble glial cells of the peripheral nervous system in immunohistochemical, ultrastructural, and also functional properties, and may belong to the glial lineage, originating from the neural crest.

Adrenal Medulla↗
PubMed1996

Differential distribution of S-100 protein and vimentin in the hypophyseal pars tuberalis of the guinea pig.

In the hypophyseal pars tuberalis of guinea pigs, I examined immunohistochemical localization and development of vimentin and S-100 protein in comparison with those of the pars distalis. In the pars distalis, almost all folliculostellate cells expressed intense immunoreactivity for vimentin. A subpopulation of vimentin-immunoreactive folliculostellate cells was also immunoreactive for S-100 protein. During fetal development, vimentin-immunoreactive cells appeared at mid-gestation in the pars distalis and became numerous at late stages, whereas only a few S-100 immunoreactive cells were observed even at late stages. In the pars tuberalis, a large number of vimentin-immunoreactive cells were distributed in the cranial region surrounding the median eminence and the dorsocaudal region surrounding the infundibular stalk. These cells, however, were sparse in the ventrocaudal region in continuity with the pars distalis. Conversely, dense distribution of S-100 immunoreactive cells was restricted in the ventrocaudal region. Vimentin-immunoreactive cells were elongated and were mostly distributed as solitary cells, whereas S-100 immunoreactive cells were gathered in large or small cell groups and frequently formed colloid-containing follicles. During fetal development, large cell groups immunoreactive for S-100 protein were detected at late stages in the ventrocaudal region. Therefore, in the pars tuberalis S-100 immunoreactive cells are distinct from the vimentin cells and do not correspond to the folliculostellate cells of the pars distalis.

Animals↗
PubMed1996

Ultrastructural immunogold localization of vimentin and S-100 protein in guinea pig pars tuberalis.

Ultrastructural features of vimentin- and S-100 protein-positive cells in guinea pig pars tuberalis were examined by immunoelectron microscopy with the postembedding immunogold method. Interstitial cells that exhibited elongated cytoplasm and partly surrounded the specific secretory cells were filled with intermediate filament bundles on which immunogold particles for vimentin were densely located. Small colloid-containing follicles were occasionally distributed in the cranial region surrounding the median eminence. The follicular cells lining the luminal cavities contained considerable amounts of intermediate filaments immunoreactive for vimentin. Some specific secretory cells displayed various amounts of intermediate filaments immunoreactive for vimentin, which were scattered throughout the cytoplasm or concentrated around the nucleus. The specific secretory cells in which many parallel profiles of rough endoplasmic reticulum (RER) or a large number of mitochondria were dispersed throughout cytoplasm, i.e., being highly metabolically active, were devoid of intermediate filaments. The ventrocaudal region in continuity with the pars distalis was occupied by cells that were packed with vesicular inclusions, considered to be dilated cisternae of RER, and frequently formed colloid-containing follicles. Immunoreactivity for S-100 protein was located exclusively in this novel cell type. Immunogold particles for S-100 protein were distributed in the cytoplasmic matrix and were also associated with the membrane of vesicular inclusions. Gold particles were also detected on the tight junctions, desmosomes, and fibril materials at the apical cell regions of the colloid-containing follicles. The finding of two separate populations of cells containing vimentin and S-100 protein, respectively, supports the idea of functional separation in the pars tuberalis.

Animals↗
PubMed1996

[Ten-year survival and cardiac event-free rates in Japanese patients with the left anterior descending artery revascularized with internal thoracic artery or saphenous vein graft: a comparative study].

To evaluate the long-term results of surgical patients with coronary artery bypass grafting (CABG), we comparatively analyzed the 10-year survival and cardiac event-free rates between 713 patients group with at least one internal thoracic artery to the left anterior descending artery (LAD), (ITA-CABG) and 241 patients group revascularized with vein grafts alone (SVG-CABG). ITA-CABG patients had more progressed diseases with a higher incidence of risk factors than SVG-CABG patients: number of vessel diseased 2.5 +/- 0.7 vs 2.3 +/- 0.7, LMTD 20.2% vs 14.1%, diabetes mellitus 37.3% vs 27.0% and hyperlipidemia 38.0% vs 30.7%. The 10-year cumulative LAD graft patency and severe disease-free rate was 90.3 and 67.0% for ITAs and vein grafts in this series. The 10-year overall actuarial survival, cardiac death-free and cardiac event-free rates for ITA and SVG groups were 88.8 vs 79.5%, 97.4 vs 92.6% and 84.1 vs 73.1%, all with a statistical significance (generalized Wilcoxon or logrank method). For the patients with reduced ventricular systolic function (EF < or = 0.4), ITA-CABG offered a significantly better 10-year cardiac death free rate. Also, for the diabetic patients, ITA-LAD offered a significantly better 10-year cardiac event-free rate. In conclusion, the use of ITA graft can reduce postoperative cardiac events and enhance the long-term survival in Japanese patients. The ITA should be utilized at least for LAD in all CABG patients whenever feasible.

Coronary Artery Bypass↗