Search PubMed⌕ Search

Biomedical subjects

T Iwase

Publications and source records attributed to T Iwase.

At least 127 records · Page 7Linked to original sources
PubMed1995

Long-term results of intertrochanteric varus osteotomy for arthrosis of the dysplastic hip (over 10 years' follow-up).

We performed a retrospective clinical and radiographic review of the long-term results of 64 hips in 53 patients who underwent intertrochanteric varus osteotomy for arthrosis of the hip at the pre- or early stage with acetabular dysplasia. Their average age at operation was 26 years. The average duration of follow-up was 18 years and 10 months. The mean Harris hip score was 77 +/- 9 points pre-operatively, and improved significantly to 84 +/- 13 points at the final follow-up. The acetabular coverage influenced the final outcome, and the postoperative prognosis was predictable from the acetabular head index (AHI) on a pre-operatively done hip maximum abduction radiograph (abd XP). We conclude that varus osteotomy for a dysplastic hip should be considered when the acetabular coverage is sufficient, and that a good prognosis can be expected when AHI on abd XP is greater than 60%.

Adolescent↗
PubMed1995

Experience of quadrantectomy with axillary dissection without radiotherapy sustained by serial pathological examination for stage I breast cancer.

Breast conserving treatment usually consists of lumpectomy and axillary dissection followed by a limited dose of irradiation so that no significant side-effects occur. However, the precision of lumpectomy depends on the surgical maneuver and pathological evaluation performed at each institution. For this reason, post-operative irradiation to the preserved breast and for the occult carcinoma in the same breast is absolutely mandatory, and effectively becomes a routine step. In 1986, we started to adopt the new breast-conservation method of quadranectomy with axillary dissection for restricted stage I breast cancer without using radiotherapy, at the Cancer Institute Hospital, Tokyo, Japan. As an alternative to irradiation to ensure safety, we chose to administer an elaborate pathological examination on serial sections. The pathological proof has saved troublesome post-operative irradiation, and the results have shown this method to be safe and clear-cut compared to the traditional breast-conserving treatment cited in the literature. From July 1986 to December 1994, we performed 321 cases of quadranectomy and axillary dissection (Q+Ax). If the detailed pathological examination of 5-mm serial sections revealed the stump to be negative, we did not treat the preserved breast with radiotherapy. Out of 321 cases, 247 were analyzed as being stump-negative and of these 235 did not receive radiotherapy at all. During a 5 year 4 month observation period, we have not yet encountered any local recurrence. However, we have experienced 4 cases (1.70%) in which a second cancer developed in the conserved breast. The annual incidence rate was 0.32%. These results are the best so far compared to other published world reports.

Aged↗
PubMed1995

Incidence of latent breast cancer in Japanese women.

Detection of small or early neoplastic lesions is essential for the secondary prevention of cancer, and for this purpose information concerning their incidence and characteristics is required. Although data for latent or early cancers are available for various organs, details are limited in the case of the breast. The present investigation was carried out to cast light on the incidence of latent cancers, considered as lesions, in women with no symptoms and no palpable mass of the breast. Out of 2126 women visiting our hospital for initial breast examination during July to December in 1987, 542 (25.5%) had no complaint and neither a detectable mass on careful palpation nor a tumor shadow on mammography. However, 21 (3.9%) demonstrated microcalcification, 7 giving the impression of a possible malignancy. Subsequent biopsy of the 7 cases revealed 3 carcinomas. The detection rate of breast cancer in this population was thus 0.6% (3/542). Adopting the frequency (36%) of microcalcification detectable on mammography in 185 breast cancers diagnosed in this period as a base, the incidence of latent breast cancer among women visiting our hospital was calculated to be 1.5%.

Adult↗
PubMed1995

Intrasellar neuronal choristoma associated with growth hormone-producing pituitary adenoma containing amyloid deposits.

The histological, immunocytochemical, and ultrastructural features of an intrasellar neuronal choristoma associated with pituitary growth hormone (GH)-producing adenoma are reported. Immunohistochemistry studies and electron microscopy examination showed the adenoma cells to be positive for GH but negative for prolactin, and the neurons of the choristoma to have GH-releasing factor (GRF) neurosecretory activity. The adenoma also had many amyloid deposits in its extracellular space immunoreactive to GRF. This is the first report of the tumor containing amyloid deposits.

Adenoma↗
PubMed1995

Association of genetic alterations on chromosome 17 and loss of hormone receptors in breast cancer.

To investigate possible relationships between genetic alterations and hormonal deregulation during breast cancer development and/or progression, we examined 616 primary breast cancers for loss of heterozygosity (LOH) at chromosomal regions 16q24, 17p13.3 and 17q21, and for amplifications of the ERBB2 and c-MYC loci. A comparison of oestrogen receptor (ER) and progesterone receptor (PgR) status in tumour cells with data concerning these genetic alterations revealed that LOH at 17q21 was significantly correlated with absence of oestrogen receptors (ER) (P < 0.0003) or progesterone receptors (PgR) (P < 0.0001), and with the absence of both (P < 0.0001). Similarly, a significant association was observed between amplification of ERBB2 and the absence of either ER or PgR. LOH at 17p13.3 was associated with the absence of PgR (P < 0.01). These data suggest a possible relationship between specific genetic changes on chromosome 17 and hormonal deregulation in the progression of breast cancer.

Breast Neoplasms↗
PubMed1995

Cell proliferation and advancement of hepatocarcinogenesis in the rat are associated with a decrease in connexin 32 expression.

The expression of connexin 32 (Cx32), a major liver gap junction protein, after partial hepatectomy (PH) and during development and progression of hepatocarcinogenesis was studied in the rat. Cx32 was quantitatively analyzed by counting immunohistochemically demonstrated protein spots on the membranes of hepatocytes. Livers were sequentially examined after PH to assess the correlation with cell proliferation. For the analysis of different stages in carcinogenesis, Cx32 was assayed in N-ethyl-N-hydroxyethylnitrosamine-induced enzyme altered foci (EAF), hyperplastic nodules (HN), hepatocellular carcinomas (HCC), pulmonary metastatic HCC and transplanted HCC in relation to their degree of altered enzyme expression. Cx32 showed: (i) a rapid decrease after PH to its lowest levels during and 12 h after the S phase of cell proliferation when 5-bromo-2'-deoxyuridine (BrdU) labeling indices were examined; (ii) a progressive decrease from early preneoplasia EAF to HN and HCC, values for pulmonary metastatic and transplanted HCC being 0; (iii) clearly inverse correlations with increased BrdU index and degree of altered enzyme expression in HN, indicating that these, with the lowest Cx32 count, are closest to HCC. Therefore, the observed decrease appears linked to cell proliferation and progression of hepatocarcinogenesis, providing a reflection of cellular independence and growth advantage.

Animals↗
PubMed1995

CYP1A1 and CYP2E1 polymorphism and lung cancer, case-control study in Rio de Janeiro, Brazil.

Msp I polymorphism and exon 7 Ile-Val polymorphism of CYP1A1, and Rsa I polymorphism of CYP2E1 were studied in lung cancer patients and controls in Rio de Janeiro, Brazil. Of the three polymorphisms studied, only the exon 7 polymorphism of CYP1A1 (Val-containing genotypes) had a distribution which was statistically significant in the patients and controls. The contribution of Val containing genotypes of CYP1A1 exon 7 was greater in the subpopulation of squamous cell carcinoma patients with a lower life-time smoking consumption (OR, 2.92 vs 1.97). This association is consistent with the previous findings by Kawajiri et al. and the first observation of the positive association of this locus with lung cancer in a Western population (Kawajiri K, Nakachi K, Imai K, Yoshii A, Shimada N, Watanabe J. FEBS Let 1990; 263, 131-133). Furthermore, together with the lack of association of Msp I polymorphism in the non-coding region of CYP1A1, the locus truly responsible for lung cancer risk among pleural polymorphisms of CYP1A1 appeared to be exon 7 Ile-Val polymorphism. In the future, investigations of multiple markers in different ethnic populations may reveal cancer risk markers common to all mankind.

Base Sequence↗
PubMed1995

Ultrastructural change of enamel exposed to a normal pulsed Nd-YAG laser.

The ultrastructural changes of the enamel surface occurring due to normal pulsed Nd-YAG laser irradiation were examined by scanning electron microscopy. The melted and recrystallized enamel in the lased enamel surface was observed. A coalescence of enamel globules was caused by 10 pulses of laser irradiation. In the case of excessively repeated irradiation (3 applications of 10 pulses), new particles of enamel crystal were produced which had a larger size than the original and measured about 0.2-1.0 microns in diameter. In some portions, large-sized hexagonal particles were also observed. In fractured surfaces of enamel, the shapes of the new particles of enamel crystal varied and included granules, needles and columns. The column structure had various appearances such as being well packed, along with piled granules and hollow columns, as well as having intercrystal or intracrystal voids. It was suggested that a distinctive polygonal column shape of more than 2 microns in length might be formed in the process of homogeneous melting at high temperatures followed by uniform cooling and contraction. The recrystallized layer demonstrated significant acid resistance but was a little fragile. These results greatly support the hypothesis that a larger crystal size may cause acid resistance in enamel exposed to pulsed laser.

Crystallization↗
PubMed1995

Comparison of long-term efficacy of medical treatment versus percutaneous transluminal coronary angioplasty (PTCA) in single-vessel disease.

The long-term outcome of PTCA and medical therapy were compared in patients with SVD. All patients were confirmed to have > or - 75% stenosis of a major coronary artery by coronary arteriogram. The 5-year survival rates were 96.0% for medical therapy and 98.9% for successful angioplasty. Both therapies achieved an equally good long-term outcome for SVD. The incidence of nonfatal cardiac events during follow-up was higher in patients treated by PTCA than in those on medical therapy, but there was no difference between the two groups in the incidence of nonfatal MI at 5 years (2.5% vs 1.8%). The most common cardiac event in patients undergoing successful PTCA was repeat intervention associated with restenosis. In view of the long-term efficacy of PTCA, the high restenosis rate remains an important problem and it is necessary to elucidate the causes of restenosis and develop countermeasures as soon as possible.

Adult↗
PubMed1995

Comparison of long-term efficacy of medical treatment versus coronary artery bypass grafting (CABG) in multivessel coronary artery disease.

The long-term results of medical therapy and coronary artery bypass grafting (CABG) were compared in patients with multivessel disease. All patients were confirmed to have > or = 75% luminal narrowing of major coronary arteries by coronary arteriogram. When multivessel disease was stratified into double- and triple- vessel disease, the outcomes varied. In triple-vessel disease, the outcome with CABG was good, but the outcome was unfavorable in those employing medical therapy, particularly in patients with decreased left ventricular (LV) function. In patients with double-vessel disease with good LV function, the long-term results with medical therapy were just as favorable as those with CABG. However, double-vessel disease complicated by reduced LV function (ejection faction < or = 40%) had a clearly less favorable outcome when treated with medical therapy than with CABG. Thus, it is important for patients with multivessel disease to undergo revascularization if indicated, to improve their prognosis. On the other hand, the incidence of cardiac events arising from vein graft occlusions tended to increase in CABG patients after 5 years or more following surgery.

Aged↗
PubMed1995

Male reproductive toxicity of ethinylestradiol associated with 4 weeks daily dosing prior to mating in rats.

Parameters of male reproductive toxicity of ethinylestradiol were assessed by conducting a mating test, sperm assay, organ weight determination and histopathological examination. Male Sprague Dawley rats were orally administered 0.1, 0.3, 3 or 10 mg/kg/day ethinylestradiol for 4 weeks prior to mating. Body weight gain and food consumption were suppressed in all treated groups. Reproductive ability of the 3 and 10 mg/kg/day males disappeared. Slightly low copulation indices were observed in the 0.1 and 0.3 mg/kg/day groups, although fertility indices were not affected. Sperm could hardly be found in the epididymis of 3 and 10 mg/kg/day males. Sperm counts were also decreased in the other treated groups, but sperm motility was not affected. Decreased absolute and/or relative weights of testes, epididymides, prostate and seminal vesicles were observed in all treated groups along with testis, epididymis, seminal vesicle and prostate atrophy, and degenerative changes of spermatocytes, spermatids, Sertoli cells and Leydig cells. These results suggest that sperm quantification and histopathological assessment are more appropriate for assessing male reproductive toxicity of ethinylestradiol than performance of copulation and fertility tests.

Animals↗
PubMed1995

Transtrochanteric anterior rotational osteotomy for Gaucher's disease. A case report.

Avascular necrosis of the femoral head is 1 of the skeletal manifestations of Gaucher's disease, for which hip arthroplasties are performed in many cases. Because many patients are young, total hip arthroplasty in this condition has been reported to result in aseptic loosening of the components soon after operation. Osteotomy can prevent such a problem. The authors present a successful case of a 17-year-old boy who underwent transtrochanteric anterior rotational osteotomy for avascular necrosis of the femoral head in Gaucher's disease. This procedure is an effective and safe surgical treatment for this disease if performed before the onset of significant femoral head collapse or acetabular deformity.

Adolescent↗
PubMed1995

[Therapeutic efficacy of hepatectomy in the treatment of hepatic metastases from breast cancer].

This study was performed to evaluate whether or not surgical excision of hepatic metastases from breast cancer has any effect on the prognosis. Between September 1985 and April 1993, eight patients with hepatic metastases (solitary in four cases, multiple in four cases) underwent hepatectomy. Two patients among them had other remote recurrence besides that arising in the liver. Right hepatectomy in two cases, left hepatectomy in one, extended left hepatectomy in one and partial hepatectomy in four were done. No postoperative complications developed. Four patients incurred liver recurrence within an average period of 11.5 months after hepatectomy, with three of average period of 11.5 months after hepatectomy, with three of them dying from the disease within 16 to 36 months after hepatectomy. The other four were free of liver recurrence and remained alive for 3 to 65 months post-operatively. The 50% survival time was 36 months after hepatectomy and 40 months after the discovery of hepatic metastases. Although hepatectomy could only be applied to a restricted number of patients and these results are obviously insufficient, we believe that surgical procedure for liver metastases from breast cancer, if possible, is undoubtedly beneficial in prolonging the survival in such patients.

Breast Neoplasms↗
PubMed1994

Enhanced neoplastic lesion development with adenine-induced experimental multicystic nephropathy by adenine--a model system for the analysis of renal tumor generation in long-term hemodialysis patients.

To cast light on the high incidence of renal cell tumors (RCT) in long-term hemodialysis patients, the role of background multicystic nephropathy was studied in a rat model. Group 1 animals were initially given N-ethyl-N-hydroryethylnitrosamine (EHEN) then subjected to adenine feeding until killing during weeks 20-27. Groups 2 and 3 received EHEN and adenine, respectively. All rats receiving adenine developed multicystic nephropathy. The incidence of renal cell hyperplasias (RCH) and multiplicities of both RCH and RCT in Group 1 were significantly increased as compared with Group 2, suggesting multicystic nephropathy provides favorable environment for tumor development.

Adenine↗