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Biomedical subjects

K Yamaguchi

Publications and source records attributed to K Yamaguchi.

At least 343 records · Page 19Linked to original sources
PubMed2000

An unusual case of mediastinal lymphadenopathy caused by amyloidosis.

A 71-year-old Japanese female Nagasaki-atomic-bomb survivor was admitted for evaluation of a mediastinal mass. She was infected with human T-cell leukemia virus type I. Histological examination of the biopsy specimen, obtained thoracoscopically from the mass, revealed amyloid lymphadenopathy confirmed by Congo-red staining and electron-microscopic examination. Amyloid deposits and the serum monoclonal peak consisted of immunoglobulin lambda light chains. No atypical cells were detected in bone marrow. The case was diagnosed as an unusual amyloidosis affecting the mediastinal lymph node. No other sites were found to be affected by amyloidosis, although systemic involvement could not be conclusively ruled out.

Aged↗
PubMed2000

MR cholangiopancreatographic differentiation of benign and malignant intraductal mucin-producing tumors of the pancreas.

OBJECTIVE: The purpose of this study was to establish MR cholangiopancreatographic criteria for discriminating benign from malignant intraductal mucin-producing tumors of the pancreas. MATERIALS AND METHODS: Thirty-one patients with 34 intraductal mucin-producing tumors underwent MR cholangiopancreatography. Tumors were classified as either main duct type (n = 10) or branch duct type (n = 24). In patients with the main duct type, the maximum diameter and the location of the main pancreatic duct, the extent of main pancreatic duct dilatation, and the presence of a filling defect were evaluated. For branch duct type, the location and maximum diameter of the cystic lesion, the presence of a filling defect, and the presence of associated main pancreatic duct dilatation were evaluated. RESULTS: In patients with the main duct type, the main pancreatic duct was significantly narrower when associated with benign rather than malignant tumors. All malignant tumors showed diffuse main pancreatic duct dilatation, whereas all benign tumors showed segmental dilatation. Among patients with branch duct type, the cyst was smaller when it was a benign rather than malignant tumor. All but one malignant tumor showed mild associated main pancreatic duct dilatation, whereas benign tumors were not associated with main pancreatic duct dilatation. Filling defects suggested malignancy, although half of the malignant tumors had no filling defects. CONCLUSION: In patients with intraductal mucin-producing tumors of the pancreas, filling defects are indicative of malignancy. Diffuse main pancreatic duct dilatation greater than 15 mm (main duct type), or any main pancreatic duct dilatation (branch duct type), is strongly associated with malignancy.

Adenocarcinoma↗
PubMed2000

Occupational dermatoses from one-component epoxy coatings containing a modified polyamine hardener.

In an electronics plant, 2 one-component epoxy coatings containing a modified polyamine hardener were used as covering materials for protecting important information on police radio circuit boards. The resinous parts of the coatings consisted of epoxy resins based on diglycidyl ether of bisphenol F. The hardener was a dimethylaminopropylamine (DMAPA)-epoxy adduct and contained about 0.16% free DMAPA. Of 105 workers, 17 (16%) were diagnosed to have work-related dermatitis but were not patch tested. The hands were the commonly affected region (13 out of 17 cases). The latent period of dermatitis was very short (mean 21.5 days). The work-related dermatoses were closely related to the type of work and working periods. In the present study, hand protection and the introduction of automation have been demonstrated to be useful for the prevention of epoxy coating dermatitis.

Adult↗
PubMed2000

A novel mouse model of Graves' disease: implications for a role of aberrant MHC class II expression in its pathogenesis.

Mice immunized with fibroblasts expressing an MHC class II molecule and human thyrotropin receptor (TSHR), but not either alone, develop major features characteristic of Graves' disease (GD), such as thyroid-stimulating autoantibodies directed against TSHR, increased serum thyroid hormone levels, and enlarged thyroid glands. The results indicate the need for the simultaneous expression of a class II molecule and the TSHR on the surface of the fibroblasts to develop stimulating anti-TSHR antibodies and full-blown GD in our model. A T cell line established from a mouse with hyperthyroidism proliferates in response to fibroblasts expressing a class II molecule and TSHR, but not to the fibroblasts expressing only TSHR, indicating that the class II molecules on the fibroblasts present TSHR-derived peptide(s) to T cells. These results strongly suggest that the acquisition of antigen-presenting ability by thyrocytes can lead to the induction or progression of GD. We identified a T cell epitope of TSHR by the proliferative response of spleen cells from mice immunized with fibroblasts expressing a class II molecule and TSHR to 80 overlapping peptides spanning the extracellular domain of human TSHR. The identification of a major T cell epitope provides an important clue to a novel therapy of GD.

Animals↗
PubMed2000

Comparison of arthroscopic and open revision decompression for failed anterior acromioplasty.

Thirty-six consecutive patients who underwent revision decompression for refractory subacromial impingement were studied retrospectively. Average interval from the primary decompression procedure to revision was 29 months. Eighteen patients underwent arthroscopic and 18 underwent open revision. Six (33%) patients in the arthroscopic group and 12 (67%) patients in the open group were workers' compensation cases. At an average follow-up of 26 months, 17 (94%) patients in the arthroscopic group and 8 (44%) in the open group were satisfied with their procedure. Comparing workers' compensation patients, 5 of 6 in the arthroscopic group and 4 of 12 in the open group were satisfied. For nonworkers' compensation patients, all 12 patients in the arthroscopic group and 4 of 6 in the open group were satisfied. Average pain scores and postoperative range of motion was improved in both groups. Dense subacromial scarring with thick, fibrous adhesions was present in all patients. Residual, prominent bone, or an acromial spur was found in 20 (56%) patients. Overall, revision arthroscopic subacromial decompression was superior to open revision. However, there were more workers' compensation patients in the open group. Workers' compensation patients fared worse for both groups, but a significant proportion (83%) of the arthroscopic group was satisfied. Since subacromial scarring may be the most important pathology, arthroscopy is less invasive, allowing earlier, unrestricted postoperative rehabilitation and proving more effective.

Acromion↗
PubMed2000

Improvement of mannitol lysine crystal violet brilliant green agar for the selective isolation of H2S-positive Salmonella.

Mannitol lysine crystal violet brilliant green agar (MLCB) is widely used in Japan for Salmonella isolation because the medium has been commercially available. Colonies of Salmonella on MLCB appear colorless with black centers due to H2S gas production; however, most Citrobacter freundii also produce H2S gas. In order to distinguish H2S-positive Salmonella from C. freundii we have improved MLCB. To MLCB was added 1% lactose (L-MLCB). The relation for pH and black center colony formation was examined. The pH of MLCB and L-MLCB inoculated with Salmonella species was slightly acid after 7 h, but the pH of L-MLCB inoculated with C. freundii did not become acid for 24 h. The colony of C. freundii did not have a black center because the production of acid from lactose lowers the pH below 10 where it is needed for H2S to react with iron to produce black pigments. Of 99 Salmonella strains including 13 serotypes tested, all strains had the same colony morphologies on MLCB and L-MLCB. When MLCB and L-MLCB were evaluated with 36 C. freundii strains isolated from foods, only colonies on MLCB had black centers. We conclude that L-MLCB is useful for detection of nonlactose-fermenting, H2S-positive Salmonella in food samples.

Agar↗
PubMed2000

[Study on improvement of adaptation for inlay made by dental CAD/CAM CEREC 2 system].

The purpose of this study was to evaluate the effect of changes in the tapering angle of inlay casting, adhesive gap and cavosurface margin on the cavity wall adaptability of the inlay made by the dental CAD/CAM CEREC 2 system. Designed inlay castings were fabricated at three different tapering angles: 0, 3, and 6 degrees. Adhesive gap of 0, -50, -100 microns and adhesive gap of 0 micron combined with the adjustment of cavosurface margin at 2 and 4 pixels were also evaluated. The difference between the direct method with powder and the indirect method without powder were compared under all conditions. The gap between the castings and cavity walls were assessed under a telescopic microscope. Internal adaptation of castings was determined to measure the cement thickness on the surfaces sectioned in the central portion of the cavity. It was found that inlays fabricated at 3 or 6 degree taper exhibited less gap at the side wall of the cavity than those without taper. The indirect method without powder also showed less gap when compared with the direct method with powder. Marginal gap and the cement width at the side wall of the cavity were reduced when the adhesive gap was modified to -50 or -100 microns or the cavosurface margin was adjusted at 2 or 4 pixels in the outer margin. The results suggested that the indirect method with the taper of 3 or 6 degrees of inlay casting, or with adjustment of adhesive gap to -50 microns provided the best adaptability between the castings and cavity walls.

Inlays↗
PubMed2000

[Microsurgical penile revascularization in patients with pure arteriogenic erectile dysfunction].

BACKGROUND: We report the results of microscopic penile revascularization in patients with arteriogenic erectile dysfunction. METHODS: One patient with localized obstruction of the common penile artery underwent the Michal II penile revascularization, 13 patients underwent the Furlow-Fisher procedure, and 5 patients underwent the Hauri procedure. The mean age was 33.0 years and the mean follow-up period was 32 months (4-80 months). Eight patients were tobacco smokers, one patient was over 50 years old. Surgery was considered successful when the patients had a permeable anastomosis and were able to achieve satisfactory erection resulting in normal sexual intercourse. RESULTS: All surgery was successful except for one patient who had undergone the Furlow-Fisher procedure. In Spite of antithrombotic therapy, graft occlusion occurred in two patients. Post operative glans hypervascularity occurred in two patients. CONCLUSION: Penile revascularization surgery is a highly effective treatment for selected patients. There is a need for further study of graft occlusion and glans hypervascularity.

Adult↗
PubMed2000

[Ischemic heart disease in patients with erectile dysfunction].

BACKGROUND: Erection is an hemodynamic event and accordingly, erectile dysfunction is closely related with ischemic heart diseases. Sufficient study has yet to be made of this relation. METHOD: Fifty-eight patients with erectile dysfunction participated in the present study. Intracavernous injection tests and color Doppler examination were conducted for assessment of erectile function. For patients with history of ischemic heart disease, we referred to their doctor for data from their examinations. For patients otherwise, chest X-rays and electrocardiograms in the resting position were obtained and also electrocardiograms following exercise. Echocardiograms, treadmill test results, thallium exercise scintigrams, and coronary angiograms were obtained as requires for diagnosis. RESULTS: Eighteen patients (31.0%) were diagnosed as ischemic heart disease or at high risk. Although 6 of them had been already diagnosed with ischemic heart disease, 12 were newly diagnosed by the exercise tests. Among these 18 patients 16 had one or more significant risk factors for ischemic heart disease such as age, hyperlipidemia, and diabetes mellitus. 3.7% of patients whose peak systolic velocity in the cavernous artery was equal to or exceeded 35 cm/sec had ischemic heart disease or were at high risk. 54.8% of patients with peak systolic velocity of less than 35 cm/sec had ischemic heart disease or were at high risk. CONCLUSIONS: In erectile dysfunctional patients, incidence of complications with symptomatic or asymptomatic ischemic heart disease was found to be high. Therefore, in patients with risk factors or low peak systolic velocity in the cavernous artery, exercise tests should be implemented prior to treatment of erectile dysfunction.

Aged↗
PubMed2000

Sonographic differences in the appearance of acute and chronic full-thickness rotator cuff tears.

This study was undertaken to identify differences in the sonographic appearance of acute and chronic full-thickness rotator cuff tears. The ultrasonograms of 24 patients with an acute rotator cuff tear and 20 with a chronic tear were reviewed for tear size (width), location, and the presence and distribution of fluid. Among these 24 patients, 75% with a midsubstance tear location had an acute tear; 64% of patients with joint or bursal fluid had an acute tear; 80% of patients with a nonvisualized rotator cuff due to a massive tear had a chronic tear; and 73% of patients with no sonographic evidence of bursal or joint fluid had a chronic tear. In conclusion, a midsubstance location and the presence of joint or bursal fluid were more commonly associated with an acute tear. A nonvisualized cuff and the absence of joint and bursal fluid were more commonly observed with a chronic tear.

Acute Disease↗
PubMed2000

[A case of squamous cell lung cancer in a nonsmoking female, successfully treated with docetaxel and cisplatin].

A 62-year-old nonsmoking female was admitted to our hospital in May, 1998 complaining of marked cough accompanied by repeated hemosputa. Chest X-ray and CT examinations revealed a large tumor, located adjacent to a cystic lesion in the left lower lung field, in association with a clearly recognizable swelling of the ipsilateral hilar as well as the mediastinal lymph nodes. Sputum cytology after bronchofiberscopy led to the diagnosis that the patient suffered from squamous cell lung cancer of Stage IIIA with bulky N2 (T2N2M0). Chemotherapy was selected as the most reasonable treatment for this patient. The new chemotherapeutic agent docetaxel (60 mg/m2) in combination with cisplatin (CDDP: 80 mg/m2) was tried, resulting in a remarkable reduction in tumor size by 60% after the initial course of chemotherapy was completed, which fulfilled the definition of a partial response (PR). Furthermore, after 4 courses of the chemotherapy, the hilar and mediastinal lymphadenopathy had conspicuously abated and only scar tissue was visible at the site where the lung cancer was thought to have originally developed. We herein report a case in which squamous cell lung cancer sprouted in a nonsmoking female, who was successfully treated by the combined chemotherapy of docetaxel and CDDP. The present case may suggest the efficacy of newly developed docetaxel in treating non-small cell lung cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Cardiac function in dialysis patients evaluated by Doppler echocardiography and its relation to intradialytic hypotension: a new index combining systolic and diastolic function.

AIM, PATIENTS AND METHODS: Cardiac function of 40 patients on maintenance dialysis was examined using a new Doppler index combining systolic and diastolic function. Immediately before dialysis, ultrasonic pulsed Doppler was used to measure right and left ventricular inflow and outflow waveforms. The sum of the isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT) was calculated by subtracting the ejection time from the interval between the end of an inflow waveform and the start of the next inflow waveform. The new index was obtained by dividing the sum of the two isovolumetric times by the ejection time. Cardiac function was evaluated in dialysis patients and healthy controls using new indices of the right and left heart systems. RESULT: Indices of the right and left heart systems in dialysis patients were significantly higher than those in healthy controls. With respect to hypotension during dialysis, patients were divided into two groups, a group with decreased blood pressure (group A: 27 patients) and a group with normal blood pressure (group B: 13 patients). Only the left heart system index in group A was significantly higher. There were no significant differences in other M-mode Doppler indices between the two groups. CONCLUSION: The new index was a more sensitive evaluator of cardiac function and predictor of hypotension during dialysis compared to standard echocardiographic indices.

Adult↗
PubMed2000

[In vitro activities of carbapenem antibiotics against the various clinical isolates].

The annual changes of antibacterial activities of beta-lactam antibiotics, mainly carbapenem antibiotics, were investigated against 5 bacterial species, S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa, which had been isolated from the clinical materials at Toho University Omori Hospital during the period of 1995 to 1997. In addition, antibacterial activities against other main bacterial strains isolated from the clinical materials during 1997 were also determined. The five bacterial species on which annual changes of the sensitivity were investigated did not show any remarkable trend to increase in resistance to the carbapenem antibiotics tested. The antibacterial activities of the carbapenem antibiotics against MRSA were weak, and MIC90 values were between 25 and 50 micrograms/ml. In S. marcescens and P. aeruginosa on which high resistance by the production of metallo-beta-lactamase has become a problem in recent years, there were no remarkable changes in annual changes of sensitivities. Especially, MIC90 valuses of the carbapenem antibiotics against P. aeruginosa were between 12.5 and 25 micrograms/ml, 4 to 8 times better than that of PIPC, like the case of CAZ. Furthermore, the carbapenem antibiotics showed strong antibacterial activities against clinically important 16 bacterial species, from Gram-positive to Gram-negative bacteria.

Carbapenems↗
PubMed2000

Response to percutaneous transhepatic portal embolization: new proposed parameters by 99mTc-GSA SPECT and their usefulness in prognostic estimation after hepatectomy.

UNLABELLED: Accumulation of 99mTc-galactosyl human serum albumin (GSA) in the liver correlates well with the parameters of hepatic function tests. We performed 99mTC-GSA SPECT before and after percutaneous transhepatic portal embolization (PTPE) to induce compensatory hypertrophy of the remnant lobe before extensive hepatic resection and analyzed the responses of new proposed parameters in the future remnant lobe that showed hypertrophy. The aim of this study was to evaluate the usefulness of these parameters in prognostic estimation after hepatectomy. METHODS: We studied 10 patients with cholangiocarcinoma and 1 patient with metastatic liver tumor from sigmoid colon cancer. 99mTc-GSA SPECT was performed immediately before and 2 wk after PTPE. We analyzed the responses of the liver uptake ratio (LUR), functional volume (FV), and liver uptake density (LUD) in the future remnant lobe and evaluated their relationship with the prognosis after subsequent hepatic resection. RESULTS: LUR and FV increased slightly but were not associated with the prognosis after hepatic resection. LUD increased significantly after PTPE in the group showing a good outcome after hepatic resection but decreased after PTPE in the group showing a poor outcome (post-PTPE LUD, 0.064+/-0.017%/cm3 versus 0.035+/-0.006%/ cm3, P<0.05; response rate, 22.2%+/-11.9% versus -8.9%+/-17.6%, P<0.01). CONCLUSION: Responses of LUD to PTPE before hepatic resection in the future remnant lobe represent changes in asialoglycoprotein receptor activity per hepatocyte and predict responses to subsequent hepatic resection. LUD may be an important parameter for determining the outcome after hepatic resection.

Asialoglycoprotein Receptor↗
PubMed2000

Recovery of decreased local cerebral blood flow detected by the xenon/CT CBF method in a patient with eclampsia.

A 23-year-old woman presented in our hospital with toxemia, underwent cesarean section at about 36 weeks gestation, and became eclamptic in the immediate postpartum period. Following a complex partial seizure a few hours after the cesarean section, the patient experienced drowsiness, then cortical blindness. Cranial computed tomography (CT) performed at about 24 hours after the onset of the seizure showed low density areas in the bilateral occipital lobes. Intravenous magnesium sulfate was given, and the neurological symptoms disappeared within three weeks. Xenon/CT cerebral blood flow (CBF) was measured during the acute and chronic stages of the patient's eclampsia and compared with cranial magnetic resonance imaging (MRI) performed at about the same time. In the acute stage, MRI showed abnormal T2-hyperintensity signals in the head of the left caudate nucleus and in the bilateral occipital lobes, predominantly in the white matter. Xenon/CT CBF measurement showed decreased local cerebral blood flow (LCBF) in the area of the left anterior cerebral artery (ACA), the bilateral posterior cerebral arteries (PCAs), and the watershed areas of the left hemisphere. In the chronic stage, abnormal T2-hyperintensity signals remained in that part of the left occipital lobe where, in the acute stage, a marked decrease in LCBF had been detected. The main mechanism of eclampsia in this patient is thought to be a reactive vasoconstriction against hypertension rather than a vasodilatation.

Adult↗
PubMed2000

Local cerebral hemodynamic changes through the angiographic stages of moyamoya disease.

In order to elucidate the cerebral hemodynamic changes that occur in Suzuki's six angiographic stages of moyamoya disease, local cerebral blood flow (LCBF) during the stable state and CO2 responsiveness of LCBF (L-CO2R: delta %LCBF/delta PaCO2) were measured by the Xenon CT-CBF method. Nineteen patients with moyamoya disease (mean age: 36.8 +/- 11.6 years) and 11 age-matched normal volunteers were studied. The LCBF during the steady state at all stages was not significantly different from that in normal volunteers. At stage 6, however, the LCBF was slightly decreased in the anterior part of the brain, resulting in loss of "hyperfrontality." On the other hand, the L-CO2R in the anterior part of the brain tended to diminish with progression through the stages. Especially in the frontal cortex, the L-CO2R at stage 5 was significantly less than that in normal volunteers (p < 0.01) or at stage 3 (p < 0.05). In conclusion, the cerebrovascular reserve in the anterior circulation became insufficient after stage 4, although the posterior circulation was well maintained. Revascularization surgery involving the anterior circulation may be crucial to prevent ischemic events.

Adult↗