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Biomedical subjects

Y Akashi

Publications and source records attributed to Y Akashi.

At least 19 recordsLinked to original sources
PubMed2003

Macroglobulinemia and membranoproliferative glomerulonephritis in a hepatitis C virus-positive patient.

A 72-year-old female was admitted to our hospital for massive proteinuria. She had previously been diagnosed with hepatitis C virus (HCV) infection and macroglobulinemia. Renal histological examination demonstrated membranoproliferative glomerulonephritis (MPGN), and type 2 cryoglobulinemia was positive in her serum. It is generally recognized that MPGN is the most common nephritis associated with HCV infection and cryoglobulinemia, but this is the first report of an HCV-infected patient with macroglobulinemia associated with MPGN. After treatment with prednisolone and melphalan, proteinuria disappeared, but macroglobulinemia and cryoglobulinemia were not improved.

Aged↗
PubMed2000

Physiological role of endothelin-1 in nonworking muscles during exercise in healthy subjects.

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide produced by vascular endothelial cells. However, the role of ET-1 in exercise-induced physiological responses is still to be investigated. The purpose of the present study was to investigate in healthy volunteers whether the ET-1 plasma concentration in nonworking muscles is changed by exercise and to investigate the physiological role of ET-1 during exercise. Bicycle ergometer cardiopulmonary exercise tests were performed in 36 healthy men (mean age, 22.5 years). Blood samples for measuring ET-1 were drawn from the cubital vein during rest and immediately after the exercise test. The ET-1 change ratio was calculated as ET-1 immediately following exercise/ET-1 during the resting state. Cardiac output (CO) was measured during the exercise test by the impedance method. Arterial venous oxygen difference (AVO2D) when CO reached 10L/min or 15L/min was calculated as AVO2D = VO2/CO. Results were as follows: (1) the ET-1 change ratio correlated inversely with exercise time at the anaerobic threshold (r = -0.37, p = 0.03) and peak exercise time (r = -0.35, p = 0.04); (2) the ET-1 change ratio tended toward an inverse correlation with deltaVO2/deltawork rate (r = -0.29, p = 0.09); (3) the ET-1 change ratio correlated positively with AVO2D when CO reached 10L/min (r = 0.42, p = 0.02) and tended toward a positive correlation with AVO2D when CO reached 15 L/min (r = 0.32, p = 0.08). These results indicate that an increase in ET-1 in nonworking muscles may participate in the exercise-induced redistribution of blood flow and in increasing the blood flow to working muscles.

Adult↗
PubMed2000

Purulent pericarditis due to group B streptococcus and mycotic aneurysm of the ascending aorta: case report.

A 61-year-old female, with a history of uterine and cervical cancer treated with radical hysterectomy and 2 years of postoperative chemotherapy, presented to the emergency department with dyspnea on exertion. Computed tomography of the chest revealed a large pericardial effusion and a sacciform aneurysm of the ascending aorta. The patient subsequently underwent emergency pericardiocentesis with drainage of approximately 330 ml of a bloody and turbid effusion. Cultures from the effusion yielded group B streptococcus. Multiple organ failure and disseminated intravascular coagulation syndrome occurred in the acute phase, but gradually improved with continuous antibiotic therapy. On the 194th hospital day, in situ reconstruction of the ascending aorta was successfully performed using a synthetic graft. Although rarely reported, both purulent bacterial pericarditis and mycotic aneurysm can be life-threatening.

Aneurysm, Infected↗
PubMed2000

[Effect of angiotensin converting enzyme inhibitor lisinopril on sympathetic heart rate response during exercise in the early phase of acute myocardial infarction].

OBJECTIVES: Sympathetic heart rate response decreases in patients with left ventricular dysfunction. Angiotensin converting enzyme (ACE) inhibitors effectively prevent heart failure after myocardial infarction. However, the effect of ACE inhibitors on heart rate response is not well known. The present study investigated the effect of ACE inhibitors on sympathetic heart rate response in the early phase of acute myocardial infarction. METHODS: Sixty-five patients with acute myocardial infarction receiving no beta-blocking agents participated in the study. The subjects consisted of 25 patients (mean age 60.2 +/- 10.7 years) treated with ACE inhibitor lisinopril from the initial stage and 40 control subjects (mean age 57.7 +/- 7.6 years). Cardiopulmonary exercise testing with a treadmill was performed using the ramp protocol in the first month and the third month after the onset of the disease. Heart rate (HR) was measured in the resting state (rest) and immediately after peak exercise (peak). At the same time, blood samples were obtained to investigate the changes in the plasma level of norepinephrine (NE). The degree of sympathetic heart rate response was evaluated as follows: (peak HR - rest HR)/¿(peak NE - rest NE)/rest NE¿ x 100. RESULTS: There were no significant differences between the 2 groups in the first month in anaerobic threshold, peak oxygen uptake and plasma brain natriuretic peptide concentration. Though the change of heart rate was not significant, the change in the plasma level of norepinephrine was significantly lower in the lisinopril group (9.3 +/- 4.4 vs 5.7 +/- 2.8, p < 0.01). In the first month, the heart rate response in the control group was markedly lower than that in the lisinopril group (8.7 +/- 3.5 vs 15.2 +/- 8.5 beats/min/%, p < 0.01). In the third month, the significant difference between the 2 groups disappeared (10.7 +/- 7.9 vs 14.0 +/- 9.7 beats/min/%, NS) due to the increase of the value in the control subjects. CONCLUSIONS: From these results, we conclude that ACE inhibitors are effective to improve sympathetic heart rate response during exercise in the early phase of myocardial infarction.

Anaerobic Threshold↗
PubMed1999

Exercise-induced changes in plasma atrial natriuretic peptide and brain natriuretic peptide concentrations in healthy subjects with chronic sleep deprivation.

Recent observations have shown that plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) correlate with cardiac function or prognosis in heart failure patients. However, relatively little is known about changes in their plasma concentration during commonly occurring physiological states such as fatigue. Therefore, this study was designed to examine the physiological changes of plasma ANP and BNP concentrations using a chronic sleep-deprivation model. Bicycle ergometer cardiopulmonary exercise tests were performed in 10 healthy volunteers (mean age: 22.7 years). Blood samples for measuring ANP and BNP were drawn during the resting state and immediately after each exercise test. Cardiac output (CO) was measured during the exercise test by the impedance method. The study conditions were designed as follows: (A) a day following a period of normal sleep (control state) and (B) a day preceded by 1 month during which sleep lasted <60% of normal (chronic sleep-deprived state). Results were as follows. (1) Peak oxygen uptake and peak CO decreased during the sleep-deprived state compared with the control state. (2) There was no difference between peak heart rates measured during exercise under the 2 conditions. (3) Plasma ANP concentration during exercise increased significantly during the control state, whereas only a tendency toward increase was observed during the sleep-deprived state. (4) Plasma BNP concentration during exercise tended to increase in the control state compared with the resting state, whereas there was no difference in plasma BNP between after exercise and resting state in the sleep-deprived state. These results indicate that changes of ANP or BNP induced by exercise tended to be decreased by chronic sleep deprivation.

Adult↗
PubMed1999

Differential diagnosis of thymic tumors using a combination of 11C-methionine PET and FDG PET.

UNLABELLED: We assessed the usefulness of PET studies in making a differential diagnosis of thymic tumors by using 11C-methionine (MET) and 18F-fluorodeoxyglucose (FDG). METHODS: We examined 31 patients with thymic tumors, including 14 patients with thymic cancer, 9 with invasive thymoma, 5 with noninvasive thymoma and 3 with thymic cysts. The histological diagnosis was confirmed by either surgery or biopsy. MET PET and FDG PET were performed in 28 and 29 patients, respectively. Both the MET and FDG uptakes were evaluated by the standardized uptake value (SUV). RESULTS: MET uptake was not substantially different among thymic cancer (4.8 +/- 1.4), invasive thymoma (4.3 +/-1.1) and noninvasive thymoma (4.5 +/- 1.2), bat MET uptake in thymic cysts (0.9 +/- 0.1) was lower than that in the other three tumors (P < 0.01). The FDG uptake in thymic cancer (7.2 +/- 2.9) was higher than that in invasive thymoma (3.8 -/+ 1.3), noninvasive thymoma (3.0 +/- 1.0) and thymic cysts (0.9) (P < 0.01). MET uptake in thymic tumors correlated with the FDG uptake (r = 0.65), whereas MET uptake in thymic cancer was lower than FDG uptake (FDG/MET ratio = 1.52 +/- 0.52) but was higher than FDG uptake in both invasive and noninvasive thymoma (FDG/ MET ratio = 0.86 +/- 0.33). To differentiate thymic cancer from thymoma, a receiver operating characteristic (ROC) analysis was performed. The area under the curve of FDG PET was 0.90, whereas the FDG/MET ratio was 0.87. CONCLUSION: The MET PET, FDG PET and the FDG/MET ratios were unable to differentiate benign thymic tumors from malignant ones, although FDG PET was considered to be useful in the differential diagnosis between thymic cancer and thymoma. Although the difference in the uptake ratio between FDG and MET suggests a different origin of the tumors, the FDG/MET ratio is not considered to be useful as a complementary method for the differential diagnosis of thymic tumors.

Adult↗
PubMed1998

Brain potentials associated with eye fixations during visual tasks under different lighting systems.

The variations of eye fixation related potentials (EFRPs) were examined in two tasks under three lighting conditions for assessment of lighting environments. Sixteen subjects participated in two tasks; a difficult and an easy reading task under three lighting conditions: Spot light (S), General light (G) and Mixed light (M). EEG (Oz) and EOG were recorded. EEG epochs time-locked to onset of eye fixations were collected at random and averaged separately in two arrays to obtain a pair of EFRPs. Two wave forms under the S were similar, although those under the G showed the disparity, the largest disparity being in the easy task under the G. Under the S, wave forms of EFRPs were stable in the difficult task. The amplitude changed with the task load. The results suggested that EFRPs might be an index of the work load under lighting conditions.

Adult↗
PubMed1997

An evaluation of FDG-PET in the detection and differentiation of thyroid tumours.

We evaluated the usefulness of FDG-PET for the detection of thyroid tumours and the differentiation between benign and malignant tumours. The subjects consisted of 5 normal volunteers and 22 patients, including 3 with follicular adenoma, 16 with papillary carcinoma and 3 with follicular carcinoma. The results were then evaluated both visually and semi-quantitatively using the standardized uptake value (SUV). All 22 tumours were seen as areas of high FDG uptake. FDG uptake in the normal thyroid gland, follicular adenoma, papillary carcinoma and follicular carcinoma was 1.0 +/- 0.2, 2.1 +/- 0.4, 4.7 +/- 3.2 and 4.6 +/- 2.9, respectively. Significant differences were observed between papillary carcinoma and both follicular adenoma (P < 0.05) and the normal thyroid gland (P < 0.001), and between follicular adenoma and the normal thyroid gland (P < 0.001). For the diagnosis of carcinoma, 58% sensitivity, 100% specificity and 73% accuracy were obtained when the highest FDG uptake value in adenoma was taken as the threshold. Our results thus indicate that high FDG uptake in a thyroid tumour suggests malignancy even though low levels of FDG uptake cannot completely rule out malignancy.

Adenoma↗
PubMed1996

Cerebellar vascular response to acetazolamide in crossed cerebellar diaschisis: a comparison of 99mTc-HMPAO single-photon emission tomography with 15O-H2O positron emission tomography.

Various observations on the cerebellar vasoreactivity in crossed cerebellar diaschisis (CCD) have previously been reported. The purpose of this study is to clarify the difference between oxygen-15 H2O positron emission tomographic (PET) and technetium-99m hexamethylpropylene amine oxime (HMPAO) single-photon emission tomograph (SPET) findings in CCD and to evaluate the effect of the absolute values of the cerebellar blood flow as measured by 15O-H2O PET on the 99mTc-HMPAO SPET findings. The subjects comprised 15 patients with a supratentorial infarct and CCD. The cerebellar blood flow increased by about 40% at 5 and 20 min after acetazolamide i.v. on both the CCD and the non-CCD side, as measured by 15O-H2O PET. The percentage differences in cerebellar blood flow between the CCD and the non-CCD side were -22.3%+/-5.7% in the resting state, -19. 6%+/-6.4% at 5 min after acetazolamide i.v. and 21.5%+/-6.7% at 20 min after acetazolamide i.v., as measured by 15O-H2O PET, while they were -10.6%+/-5.5% in the resting state and -5.6%+/-5.1% at 5 min after acetazolamide i.v., as measured by 99mTc-HMPAO SPET. After Lassen's linearization correction, the latter two measurements were -16.2%+/-7.7% and -9.6%+/-8.9%, respectively. The effect of acetazolamide did not differ between the CCD and the non-CCD side in 15O-H2O PET, while a greater response on the CCD side was observed in 99mTc-HMPAO SPET, even after Lassen's linearization correction. It is concluded that acetazolamide HMPAO SPET may overestimate the cerebellar vascular response on the CCD side (or underestimate it on the non-CCD side).

Acetazolamide↗
PubMed1996

The usefulness of FDG positron emission tomography for the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer: a comparative study with X-ray computed tomography.

We evaluated the usefulness of fluorine-18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) in the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer and then compared the findings with the results of X-ray CT by region based on the histological diagnoses. We examined 29 patients with non-small cell lung cancer. One hundred and thirty-two mediastinal lymph nodes were surgically removed and the histological diagnoses were confirmed. FDG PET images, including 146 mediastinal regions, were visually analysed and the mediastinal lymph nodes were scored as positive when the FDG uptake was higher than that in the other mediastinal structures. On the X-ray CT scans, any mediastinal lymph nodes with a diameter of 10 mm or larger were scored as positive. All three examinations were successfully performed on 71 regions. For FDG PET, we found a sensitivity of 76%, a specificity of 98% and an accuracy of 93%. On the other hand, for X-ray CT a sensitivity of 65%, a specificity of 87% and an accuracy of 82% were observed. A significant difference was observed in respect of both specificity and accuracy (P<0.05). Based on the above findings, FDG PET is suggested to be superior to X-ray CT when used for the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer.

Aged↗
PubMed1996

FDG-PET in infectious lesions: The detection and assessment of lesion activity.

The usefulness of FDG-PET in the detection of infectious foci and the assessment of lesion activity was evaluated. The study covered 24 patients with 25 FDG-PET studies, including lesions of bacterial, tuberculous and fungal origins. The FDG uptake was determined by the lesion to muscle ratio (LMR) on the static images. The time activity curves (TACs) were classified into four patterns based on both the existence of an initial peak and a slope thereafter. A high FDG uptake was observed in 23 of 25 lesions (92%). Two lesions, in which no abnormal uptake was noted, included one in the healing stage and the other consisting of a cavity with a thin wall. The acute active lesions showed higher LMRs than the chronic active or healing lesions (mean +/- SD: 9.8 +/- 3.6, 3.6 +/- 1.8 and 4.3 +/- 1.7, respectively, p < 0.05), and they could be approximately distinguished by an LMR of 6. The patterns of the TACs in acute or chronic active lesions were either an increase without an initial peak or a plateau, while those in the healing lesions demonstrated predominantly an increase with an initial sharp peak. Our results indicated that FDG-PET is clinically useful in the detection of the infection of miscellaneous microorganisms as well as in the assessment of lesion activity.

Abscess↗
PubMed1996

A clinical evaluation of FDG-PET to assess the response in radiation therapy for bronchogenic carcinoma.

The clinical usefulness of FDG-PET in the prediction and assessment of response to radiation therapy in patients with bronchogenic carcinoma was evaluated. Thirty patients with untreated bronchogenic carcinoma were included in the study. All patients received FDG-PET before the initiation of radiation therapy, while 20 also received it after completing the therapy. The tumor to muscle ratio (TMR) was used as an index of the FDG uptake. The tumor response to therapy was classified as either a partial response (PR, n = 21) or no change (NC, n = 9) according to changes in the tumor size. Prognosis was made 6 months after the initiation of therapy, and was classified as either relapse (n = 19) or non-relapse (n = 9). The FDG uptakes both before and after therapy were compared with tumor response and prognosis. A high FDG uptake was noted in all 30 lesions before therapy. No significant differences in the uptake before therapy was observed according to the histological types nor T factors (UICC). The lesions with a higher uptake (TMR more than 7) responded better to therapy than those with a lower uptake (p < 0.05). The decrease in the uptake after therapy tended to be more prominent in the PR group than in the NC group. The rate of relapse was higher in lesions with a higher uptake before therapy (TMR more than 10) than in those with a lower uptake. The relapse group also showed a higher uptake after therapy than the non-relapse group. In addition, all 6 lesions showing a higher uptake (TMR more than 5) after therapy eventually relapsed (p < 0.05). Two lesions demonstrating a lower uptake both before and after therapy did not relapse, although no tumor regression due to the therapy was observed. These results indicate that FDG-PET plays a complementary role in both predicting and assessing the therapeutic response and prognosis in patients with bronchogenic carcinoma.

Adenocarcinoma↗
PubMed1995

[Identification and analysis of immune cells infiltrating into the glomerulus and interstitium in lupus nephritis].

This study was performed to investigate the role of cell-mediated immunity in lupus nephritis (LN). Frozen sections from 38 patients with LN were examined by indirect immunoalkaline-phosphatase labeling using monoclonal antibodies to identify the immune cells infiltrating into the interstitium and glomerulus. 14 patients showed minor glomerular abnormality (MGA), 9 had mesangial LN (MesLN), 12 had diffuse proliferative LN (DPLN) and 3 had membranous LN (MLN). Monocyte/macrophage and helper/inducer T cells infiltrated in the interstitium predominantly, but intraglomerular infiltration of these cells was rare. Monocyte/macrophage and suppressor/cytotoxic T cell levels were significantly higher (p < 0.05) in the interstitium in DPLN patients and monocyte/macrophage level was significantly higher (p < 0.05) in MesLN patients than in MGA patients. In the interstitium, serum creatinine level was highly correlated with infiltrations of suppressor/cytotoxic T cell, monocyte/macrophage (p < 0.01), pan T cell and total leucocyte (p < 0.05). Clinical activity score was correlated with suppressor/cytotoxic T cell (p < 0.001), monocyte/macrophage and pan T cell (p < 0.01). These results suggest that suppressor/cytotoxic T cell and and monocyte/macrophage may play an important role in the progression of lupus nephritis.

Antibodies, Monoclonal↗
PubMed1995

Participation of histones and ubiquitin in lupus nephritis.

To evaluate the role of histones and ubiquitin in lupus nephritis, we searched for glomerular deposits of histones and ubiquitin in renal biopsy specimens from 53 patients with systemic lupus erythematosus (SLE) and 30 with non-lupus glomerulonephritis. Glomerular immunofluorescence staining revealed positive for histone H2A, H1 + H3, H4 and ubiquitin in 49.1% (26/53), 45.3% (24/53), 32.1% (17/53) and 22.6% (12/53) of the SLE patients, respectively. Non-SLE renal biopsies revealed absence of positive staining with histone H2A, H1 + H3, H4 and ubiquitin. The positive incidence of histone H1 + H3 and ubiquitin in diffuse proliferative lupus nephritis was significantly different (p < 0.01) from that in minor glomerular abnormality. Levels of CH50 in patients with glomerular deposition of histone H1 + H3 (p < 0.001) and ubiquitin (p < 0.01) were significantly lower than in patients without deposition. Levels of anti-DNA antibody in patients with glomerular deposition of histone H1 + H3 were significantly higher than in patients without deposition (p < 0.05). Only the positive incidence of glomerular deposition of ubiquitin was correlated with the histological activity index (p < 0.05). These results suggest that histones and ubiquitin may play an important role in the induction of lupus nephritis.

Histones↗
PubMed1995

[Detection of anti small nuclear ribonucleoprotein antibody in patients with collagen disease--a comparison of sensitivities of four methods].

OBJECTIVE: To compare the sensitivity of four techniques that can detect the presence of anti small nuclear ribonucleoprotein (snRNP) antibodies. MATERIAL AND METHOD: Sera from eighty three patients with connective tissue disease were positive for antinuclear antibody by indirect immunofluorescence test. Patients consisted of 30 cases of systemic lupus erythematosus, 19 of rheumatoid arthritis, 9 of mixed connective tissue disease, 8 of systemic sclerosis, 3 of polymyositis, 13 of Sjögren syndrome, 1 of unclassified connective tissue disease. Four methods including double immunodiffusion (DID), enzyme linked immunosorbent assay (EIA), immunoprecipitation (IP) and immunoblotting (IB) were compared concerning their sensitivities of detecting anti-Sm and anti-RNP antibodies in these sera. RESULTS: Overall sensitivities for detecting the presence of each antibody were similar among four methods (DID: 32/83, EIA: 43/83, IP: 44/83, IB: 35/83). Concordance ratio of positive patterns between DID and EIA was 63/83 (81.9%). However, both EIA and IP could detect anti-U1 RNP antibody with higher sensitivity than DID. Although EIA seemed to detect anti-Sm antibody most sensitively in all methods, a coincidental decrease of specificity might be considered. IB could not classify anti-snRNP antibodies into anti-Sm and/or anti-RNP antibody because these antibodies might share some antigenic peptides of snRNP. Analysis of RNA in immunoprecipitate could not discriminate anti-RNP antibodies from anti-Sm antibodies because of shared RNA epitopes (e.g., U1-RNA, U1U2-RNA). CONCLUSION: These results suggested that EIA might be the most suitable method for detecting anti-RNP antibody and that several methods should be combined for detecting anti-Sm antibody.

Antibodies, Antinuclear↗