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Biomedical subjects

K Imai

Publications and source records attributed to K Imai.

At least 739 records · Page 41Linked to original sources

Diagnostic significance of prostate specific antigen and the development of a mass screening system for prostate cancer.

PURPOSE: The significance of prostate specific antigen (PSA) in the mass screening for prostate cancer was investigated. MATERIALS AND METHODS: A total of 4,375 PSA, digital rectal and transrectal ultrasonographic examinations was performed on 3,526 subjects. RESULTS: Among the 3 modalities, PSA had the highest sensitivity (80.4%) and positive predictive value (45.1%). We established age-specific reference PSA ranges for normal Japanese men, and demonstrated the significance of PSA density and PSA velocity. CONCLUSIONS: The significance of PSA as a prostate cancer screening modality should be evaluated across multiple age ranges and in combination with previous PSA data and/or prostate volume.

Adult↗

Differential effects of the immunosuppressants cyclosporin A, FK506 and KM2210 on cytokine gene expression.

Cyclosporin A (CsA) inhibited interleukin 2 (IL-2), IL-3, interferon gamma (IFN gamma), GM-CSF and tumor necrosis factor alpha (TNF alpha) mRNA expression in spleen cells stimulated with concavalin A (Con A) when determined by the semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) method. FK506 which has a similar immunosuppressive mechanism to that of CsA also showed the same inhibitory effects except for decreased IL-5 and IL-6 mRNA expression. In contrast, both CsA and FK506 enhanced transforming growth factor beta (TGF beta) and IL-1 beta mRNA expression. Another immunosuppressant KM2210 did not show any inhibitory effects on cytokine gene expression but rather enhanced IL-10, IL-6, TGF beta and IL-1 mRNA expression, thus suggesting that KM2210 has a completely different immunosuppressive mechanism from that of CsA and FK506. Anti-TFG beta 1 antibody abrogated the suppression by KM2210 of BALB/c anti-3H/He mixed lymphocyte reaction (MLR) whereas this antibody did not abrogate the suppression by CsA and FK506 of BALB/c anti-C3H/He MLR. These results indicate that TGF beta is one of the major cytokines in KM2210 immunosuppression, in addition to IL-10, but not in immunosuppression by CsA and FK506.

Animals↗

[Pericardial effusion following surgery using cardiopulmonary bypass].

Of 156 patients who underwent cardiac or aortic surgery using cardiopulmonary bypass, postoperative pericardial effusion was detected in 89 patients (57%). They were divided into four groups according to the size of pericardial effusion: No effusion (group N, n = 66), small effusion (group S, n = 42), moderate effusion (group M, n = 22) and large effusion (group L, n = 25). In group L, 68% of patients had symptoms and 44% had complications such as subxiphoid drainage and constrictive pericarditis. Fewer patients with perioperative pleurotomy were found in group L than group N (p < 0.05). Postoperative anticoagulation did not affect the size of pericardial effusion. Postoperative amount of drainage were larger in groups, S, M, L than group N (p < 0.05, p < 0.05, p < 0.005). The CRP reelevation rate of each group was equal but the maximum CRP value was higher in group L than group N (p > 0.05). These results suggest that some relationship exists among postoperative drainage, inflammatory response and postoperative pericardial effusion. Since large pericardial effusion is often symptomatic and accompanied by various complications, earlier detection of pericardial effusion and appropriate treatment seems to be essential.

Adult↗

[A case of surgical treatment of acute aortic dissection without an intimal tear].

We experienced a case of acute aortic dissection without an intimal tear. A 55-year-old woman with SLE presented with acute chest pain. TEE study showed dissection of the ascending aorta, and accompanied by pericardial effusion. An emergency operation was performed four hours after onset. Intraoperatively, thrombus was encountered in the false lumen of the ascending aorta and the proximal arch. However, intimal tear was not found. She underwent graft replacement of the ascending aorta and the total aortic arch, and had an uneventful postoperative course. Histological examination of a segment of ascending aorta showed no evidence of mucinous degeneration and pathological rupture of the elastic fiber.

Acute Disease↗

A case of isolated acute DeBakey II redissection occurring in a postoperative survivor who underwent an arch replacement for acute DeBakey IIIb dissection.

A case of isolated acute DeBakey II redissection which occurred in a postoperative survivor who underwent an arch replacement for acute DeBakey IIIb dissection is reported. The operative findings revealed that there was an intimal tear above the left coronary cusp, that there was a false lumen in the native ascending aorta, and that a residual false lumen caused by the initial operation had not been detected. Redissection caused mainly by the operative procedure, such as the failure to include the site of the intimal tear in the original repair and the formation of a new dissection as a result of anastomotic failure, is frequently seen. However, isolated redissection is a rare condition. In this paper we discuss classification, diagnosis and treatment of redissection.

Aortic Dissection↗

[Artificial defect on myocardial SPECT image due to extra-cardiac MIBI accumulation].

If 99mTc-methoxy isobutylisonitrile (MIBI) myocardial scintigraphy was performed on the rest-stress protocol, MIBI accumulated in extra-cardiac area, gallbladder or liver, on rest image significantly. The purpose of this study was to evaluate whether extra-cardiac MIBI accumulation influences the quality of myocardial images. Rest-stress MIBI myocardial scintigraphy was performed in 90 patients. Fifteen patients showed defects on rest image in spite of normal findings on stress image. Before and after removing the area of extra-cardiac MIBI accumulation on projection images, SPECT was reconstructed in the 15 patients. Perfusion defect on rest image improved in 66% of patients (10/15) and 37% of total segments (33/89) by removing the area of extra-cardiac MIBI accumulation. Furthermore, it was 21% (4/19), 38% (11/29), 43% (16/37) and 50% (2/4) in anterior, septum, posterior and lateral segments respectively. Significant MIBI extra-cardiac accumulation, especially in the gallbladder, is one of the causes of artificial defects on rest image. Thus, reconstruction of SPECT after removing area of MIBI extra-cardiac accumulation will be an appropriate method to improve the quality of MIBI images.

Female↗

[Clinical study on 78 cases of testicular tumor].

Seventy eight patients with testicular tumor were treated in our hospital between 1982 and 1992. Of 78 patients, 74 had germinal cell tumor (seminoma in 47 patients and non-seminoma in 27), and the other 4 had 3 malignant lymphoma and 1 rhabdomyosarcoma. Ages ranged from 1 to 67 years with the average of 36.1. The age of the patients with seminoma was significantly higher than that of patients with non-seminoma. Most patients complained of painless swelling of the scrotal content, but some patients complained of testicular pain, fever, and so on. Those who complained of such symptoms had significantly worse prognosis than those who had only painless scrotal swelling. Patients with non-seminoma visited us about 4.9 months after the onset of their symptoms and 12.1 months in seminoma. Clinical stages were more progressive in non-seminoma than in seminoma. Inguinal orchiectomy was performed followed by irradiation, chemotherapy, retroperitoneal lymph node dissection or thoracotomy. Recurrence developed in 6 patients and the other 7 patients died of progressive disease within 2 years from the first attendance. The 2-year survival rate calculated by the Kaplan-Meier method was 81 and 70% in seminoma and non-seminoma, respectively, and 100, 88, 63, 75, and 22% in stage I, IIA, IIB, IIIO and IIIA, B, C, respectively.

Adult↗

Cardiac sympathetic denervation in transthyretin-related familial amyloidotic polyneuropathy: detection with iodine-123-MIBG.

In familial amyloidotic polyneuropathy (FAP), the peripheral nervous system is predominantly impaired. Cardiac sympathetic function has not been directly assessed. A 65-yr-old man with severe peripheral neuropathy due to primary systemic amyloidosis was studied. Echocardiograms and scintigraphic examinations with 20Tl and 99mTc-pyrophosphate demonstrated highly thickened but normally perfused left ventricular walls with intense diffuse amyloid deposits. No definite myocardial activity of [123I]metaiodobenzylguanidine (MIBG) was detected in any cardiac region, indicating lack of sympathetic nerve endings. Despite maintained cardiac contractility, left ventricular diastolic performance and heart rate variability assessed by power spectral analysis were markedly depressed. Thus, the myocardial defect of MIBG activity may provide direct evidence of impaired cardiac sympathetic nerve endings due to amyloid deposits in FAP.

3-Iodobenzylguanidine↗

[Efficacy of simultaneous function and perfusion imaging on 99mTc-tetrofosmin myocardial scintigraphy].

The aim of this study was to determine whether the diagnosis for coronary artery disease (CAD) with 99mTc-tetrofosmin (Tf) myocardial scintigraphy was improved by the combination of function image and perfusion image as compared with perfusion alone. Tf myocardial scintigraphy was performed with one-day protocol (stress/rest) in 51 patients (CAD: 32, Non-CAD: 19) without previous myocardial infarction. Function image was obtained by first pass method, and perfusion image by SPECT. Number of diseased vessels was 14 in right coronary artery (RCA), 18 in left anterior descending (LAD), and 12 in left circumflex (LCX). Ischemia was diagnosed by 2 different parameters 1) perfusion image alone, 2) combination of perfusion image and regional ejection fraction (rEF). On perfusion image, accuracy was 53%, 94% and 86% in RCA, LAD, and LCX respectively. On perfusion + rEF, accuracy was 76%, 90% and 84% in RCA, LAD, and LCX respectively. Specificity in RCA was 45% on perfusion, 84% on perfusion + rEF. Sensitivity in RCA was 77% on perfusion, 54% on perfusion + rEF. LAD and LCX did not change by the addition of function image. By addition of function image, accuracy and specificity of diagnosis in area of RCA improved significantly (p < 0.01). Thus the addition of function image in Tf myocardial scintigraphy would be useful to improve the diagnosis, especially in region of RCA.

Aged↗

[Atrophic gastritis in Sjögren's syndrome].

In patients with Sjögren's syndrome (SJS), it has been found that chronic atrophic gastritis is often associated with low HCl secretion or achlorhydria. However, the role of autoimmune injuring mechanism in the pathogenesis of the atrophic gastritis in SJS is unclear. In recent studies, Helicobacter pylori (HP) infection is accepted as the major cause of chronic gastritis. In our studies, HP infection was present in the half of SJS patients with atrophic gastritis. We also determined HP specific IgG antibody levels by enzyme-linked immunosorbent assay (ELISA). In SJS patients with gastric inflammatory cell infiltration, the IgG levels were high. We determined gastric parietal cell antibody (PCA) levels by ELISA, using a recombinant fusion protein of the alpha subunit of gastric H+, K(+)-ATPase. Our observation suggests that atrophic gastritis in SJS is caused by HP infection associated with gastric mucosal injury due to PCA.

Autoantibodies↗

Carboplatin-based combination chemotherapy for testicular cancer: relationship among administration dose of carboplatin, renal function and myelosuppression.

Carboplatin (CBDCA), a derivative of cis-diamminedichloroplatinum, has low renal and neural toxicity. The dose-limiting factor of this agent is myelosuppression. We experienced various degrees of myelosuppression, when the dose of CBDCA was determined by the body surface area (BSA) in CBDCA-based combination chemotherapy for testicular cancer. Calvert demonstrated that the dose of CBDCA administered should be adjusted by renal function, because CBDCA was excreted through the glomerulus. We report the relationship among 3 factors; the administration dose of CBDCA, renal function and the degree of myelosuppression. We treated 6 patients with testicular cancer. A total of 22 courses of CBDCA-based combination chemotherapy was performed. The area under the curve (AUC) was calculated by the following formula, which was demonstrated in Calvert's study. CBDCA dose = AUC x (GFR + 25), GFR; glomerular filtration rate. The degree of myelosuppression was examined. All chemotherapy courses were divided into 2 and 3 groups according to BSA and AUC, respectively. WBC and Plt reduction rates and nadir counts were significantly correlated with AUC, and showed no significant relationship to the dose determined by BSA. This study revealed that the degree of myelosuppression was closely related with AUC, which reflects the renal function.

Adult↗

Production of matrix metalloproteinases at the bone-implant interface in loose total hip replacements.

BACKGROUND: Incidence of aseptic loosening of hip prostheses is increasing in recent years. Previous studies suggested involvement of proteinases and cytokines in the accelerated bone lysis associated with loosening. EXPERIMENTAL DESIGN: To investigate the role of matrix metalloproteinases (MMPs) in the loosening we immunolocalized MMP-1 (tissue collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin-1), MMP-9 (gelatinase B) and their common inhibitors, tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2), in the bone-prosthesis interface membranes. In situ hybridization was performed for the detection of MMP-9 mRNA in the membranes. The amounts of these MMPs and TIMPs in the tissue were measured by the sandwich enzyme immunoassays and enzyme activities assayed using radiolabeled collagen, gelatin, and carboxymethylated transferrin substrates. We also examined the ability of the cells from interface membranes to resorb mouse calvaria bone. RESULTS: The membranes obtained from the loose bone-implant interface were composed of fibrous granulation tissue containing numerous multinucleated giant cells with high density polyethylene debris. Immunohistochemical examination revealed that the giant cells were strongly positive for MMP-9 and weakly for MMP-1. Expression of MMP-9 mRNA in the cells was demonstrated by in situ hybridization. MMP-2 and TIMP-2 were immunolocalized mainly in the fibroblasts. TIMP-1 was localized in the endothelial cells of the blood vessels and weakly in fibroblasts. However, MMP-3 was almost negative in the membrane tissue. Sandwich enzyme immunoassays showed that MMP-9 levels are significantly higher in both homogenates and culture media of the cup and stem interface membranes than the control pseudocapsule. Gelatinolytic activity was also remarkably higher in the membrane samples than the control. The cells isolated from the membranes had no ability to resorb calvaria bone. CONCLUSIONS: These data demonstrate that MMP-9 is produced by the multinucleated giant cells appeared by the reaction to polyethylene debris in the interface membranes. This proteinase may play a role in degradation of the extracellular matrix macromolecules present around and on the surface of the bone trabeculae, facilitating the osteoclastic bone resorption.

Adult↗

[Anterior nerve roots enhancement on MRI in a case of Guillain-Barré syndrome].

A 4-year-old girl with Guillain-Barré syndrome (GBS) showed the abnormal enhancement on MRI in the anterior nerve roots corresponding to the region of her muscle weakness on the 26th day of illness. The enhancement on MRI almost disappeared on the 89th day of illness, when her symptoms had more improved. We think that enhanced spinal MRI is useful to reveal the involved nerve roots and the degree of the illness in GBS.

Child, Preschool↗

[Epidemiological study of risk factors for bladder cancer].

A case-control study was conducted on 303 male bladder cancer patients and controls. General population controls were chosen from 15 areas in Gunma Prefecture and were matched by age (+/- l y.o.) to the subjects. Age-adjusted and smoking-adjusted odds ratio (O.R.) and a 95% confidence interval (C.I.) were calculated for each item. Risk factors for bladder cancer in men were investigated. The O.R. tended to be significantly higher for those who had history of smoking, who smoked more per day, who had smoked longer, whose Brinkman index was higher, who began smoking younger and who inhaled deeper than it was for non-smokers. O.R.s of having a past history or complication of cystitis (age-adjusted) and benign prostatic hypertrophy (age- and smoking-adjusted) were significantly higher, but the difference was supposed to be caused by bias. There was a significantly lower age- and smoking-adjusted O.R. for bladder cancer in men who engaged in sales, whose blood type was O, who drank milk frequently, who ate grains frequently, who age vegetables frequently and who had a past history or complication of hypertension. The number of cases and controls with first degree family members who developed cancer respectively supposed to be highly related to smoking, were as follows; 16 and 8 for lung cancer, 3 and 0 for larynx cancer and 6 and 3 for bladder cancer. The following characteristics failed to show any significant difference between subjects with bladder cancer and the control group; height and weight now and 20 years ago, jobs which deal with dye, academic career, marriage, number of children, alcohol drinking and the use of hair dye or analgesics.

Adult↗

[Usefulness of myocardial T2-weighted MR imaging using the turbo spin echo technique].

Myocardial T2-weighted imaging using the turbo spin echo technique was superior to the conventional spin echo technique because of the shorter scan time and reduced artifacts. Furthermore, single cardiac phase images of all planes could be taken within a short scan time. T2-weighted imaging using the turbo spin echo technique was an effective method to evaluate myocardial abnormalities.

Humans↗

A case of traumatic pseudoaneurysm of the ascending aorta occurring in a postoperative patient who underwent arch replacement and Bentall's operation.

A case of traumatic pseudoaneurysm of the ascending aorta occurring in a postoperative patient who underwent an arch replacement and Bentall's operation was reported. A bleeding point was clear at the graft of the ascending aorta, and a pseudoaneurysmal formation was suspected following an echocardiogram. An aortogram demonstrated the presence of an aneurysm approximately 8 cm by 4 cm in size originating 5 cm above the right coronary ostia. An emergency operation was carried out. A Trans-femoral bypass was established before sternotomy. The Operative findings showed that adhesive connective tissue covered a pseudoaneurysm 8 cm by 4 cm in size, and that there was a tear in the anastomosis of the grafts between the ascending aorta and the arch 5 cm above the coronary ostia. Direct suture was performed, using hypothermic circulatory arrest. In this paper, We discuss the mechanism, classification, and operative strategy of traumatic pseudoaneurysm.

Adult↗