Biomedical subjects

Y Akashi

Publications and source records attributed to Y Akashi.

At least 37 records · Page 2Linked to original sources

PubMed1995

Improved myocardial fatty acid utilization after percutaneous transluminal coronary angioplasty.

Exercise-reinjection 201Tl imaging and resting 20-min and 3-hr BMIPP imaging were performed before and 4 mo after percutaneous transluminal coronary angioplasty (PTCA) in a patient with effort angina. Before PTCA, exercise 201Tl imaging showed decreased 201Tl activity in the septal wall, with significant fill-in on the reinjection 201Tl image. The resting 20-min BMIPP image showed decreased activity in the septal wall, with a slight redistribution on the 3-hr BMIPP image. The 201Tl and BMIPP images 4 mo after PTCA showed significant improvement in the 201Tl pattern and BMIPP uptake in the septal wall with no abnormally decreased activities.

Aged↗

PubMed1995

[A comparison of the cerebrovascular responses to CO2 and Diamox in patients with unilateral occlusive cerebral arteries: a H2(15)O PET study].

We studied the relationship between the cerebrovascular responses to CO2 and Diamox in patients with chronic cerebrovascular diseases. The subjects consisted of 11 patients with unilateral occlusive or highly stenotic carotid artery. The cerebral blood flow was measured at the resting state, during the inhalation of 5% CO2, at both 5 and 20 min after Diamox i.v. (1 g). The rCBF ratios (occlusive/non-occlusive side) during the inhalation of CO2 and 20 min after Diamox i.v. closely correlated with each other. However, the ratio at 5 min after Diamox i.v. was slightly lower than that during the inhalation of CO2. The percent increases of rCBF also showed a significant correlation between 5% CO2 inhalation and 20 min after Diamox i.v. However, the rCBF decreased inversely at 5 min after Diamox i.v. in some regions on the occlusive side, which indicates the presence of a so-called "steal phenomenon". The percent increases in the rCBF after 1 g Diamox i.v. were more or equal to those during the inhalation of 5% CO2. The CO2 and Diamox were thus considered to be equally useful in the evaluation of the perfusion reserve capacity. However, these various characteristics as described above should be considered in the clinical practice.

Acetazolamide↗

PubMed1995

[The relationship between the cerebral blood flow, oxygen consumption and glucose metabolism in primary degenerative dementia].

The CBF, CMRO2 and CMRGlu were measured in patients with primary degenerative dementia including 5 patients with dementia of Alzheimer's type and 4 patients with Pick's disease, and then the correlation between the cerebral blood flow and energy metabolism was evaluated. The control subjects consisted of 5 age-matched normal volunteers. The CBF, CMRO2 and CMRGlu decreased in the bilateral frontal, temporal and parietal regions in the patients with Alzheimer's dementia, while they decreased in the bilateral frontal and temporal regions in the patients with Pick's disease. Both the CBF and CMRO2 were closely correlated with each other. However, the CMRGlu was more severely impaired than the CBF or CMRO2 in both pathological conditions. These results suggested that CMRGlu began to decrease before the reduction of the aerobic metabolism and thus measuring the CMRGlu is considered to be the most sensitive method for detecting abnormal regions in primary degenerative dementia.

Aged↗

PubMed1995

[Cerebral hemodynamics and metabolism in patients with Moyamoya disease not demonstrating either cerebral infarct or hemorrhage on MRI].

We evaluated the cerebral hemodynamics and metabolism in Moyamoya patients who did not demonstrate either cerebral infarct or hemorrhage on MRI. The subjects consisted of 5 patients with Moyamoya disease (4 females and one male, aged from 15 to 40 years). The CBF, OEF and CMRO2 of the Moyamoya patients did not differ from those of the normal control subjects. The CBV did increase significantly in the cerebral cortices and striatum, but not in the cerebellum. The TT was also significantly prolonged in the frontal and parietal regions. The cerebrovascular CO2 response was markedly impaired in the frontal, temporal and parietal cortices. However, it was relatively preserved in the occipital cortex, thalamus and cerebellum. Thus, the cerebral hemodynamic reserve capacity decreased even in the Moyamoya patients not demonstrating either cerebral infarct or hemorrhage on MRI, and it should be considered in the management of these patients.

Adolescent↗

PubMed1995

[Two cases of micrognathia caused by radiation therapy during infancy: an evaluation of their profilograms].

Two patients with micrognathia of the mandible caused by radiation therapy during infancy are reported herein. The first patient was a 25-year-old man with hemangioma of the tongue. He had previously received radiation therapy totaling 51 Gy at 1 and 2 years of age. The other patient was a 54-year-old woman who had received radiation therapy for an oral tumor during infancy. These two patients demonstrated micrognathia, and the former patient showed developmental anomaly of the teeth. In addition, the latter patient suffered from thyroid cancer at 45 years of age, and this was also thought to be radiation-related. Although reports of micrognathia caused by radiation are rare, such late effects should be taken into account when radiation therapy is planned for head and neck tumors in infants.

Adult↗

PubMed1994

Striatal 18F-dopa uptake and brain glucose metabolism by PET in patients with syndrome of progressive ataxia.

Striatal 18F-Dopa uptake and brain glucose metabolism were studied by PET with 6-L-[18F]flurodopa and [18F]fluorodeoxyglucose in 11 patients with syndrome of progressive ataxia. Five of the 11 patients were diagnosed as having cerebellar cortical degeneration (CCD), including 3 with late cerebellar cortical atrophy and 2 with Holmes type hereditary ataxia while 6 demonstrated olivopontocerebellar atrophy (OPCA). The caudate and putaminal 18F-Dopa uptake ratios to the occipital cortex in CCD showed no significant difference from those in the controls. On the other hand, those with OPCA decreased as compared to the controls. In addition, the cerebellar glucose metabolism in CCD decreased as compared to the controls, while that in the brainstem showed no significant decrease from the controls. The glucose metabolic rates both in the cerebellar hemisphere and in the brainstem in the OPCA patients decreased compared to the controls. The cerebral cortical, striatal and thalamic glucose metabolisms were normal in both the CCD and OPCA in groups. The appearance of a decreased glucose metabolism in the cerebellum is considered to be relevant in the genesis of cerebellar ataxia, even though their underlying diseases were different from each other. The differences in the glucose metabolism of the brainstem and in the nigrostriatal presynaptic dopaminergic function between CCD and OPCA as assessed by PET may be caused by differences in the pathophysiological mechanism between CCD and OPCA, and those differences appear to be useful when making a differential diagnosis of CCD and OPCA.

Adult↗

PubMed1994

Relationship between various parameters derived from 123I-labelled beta-methyl-branched fatty acid whole-body scintigraphy and left ventricular ejection fraction in patients with ischaemic heart disease.

Heart uptake and clearance of 123I-15-(p-iodophenyl)-3(R,S)-methyl- pentadecanoic acid (BMIPP) by whole-body scintigraphy in relation to left ventricular ejection fraction (LVEF) was evaluated in 34 patients with ischaemic heart disease. At 45 and 210 min after injection, anterior whole-body images were obtained. In each patient, multigated blood pool scintigraphy was also performed, and LVEF was calculated. The percentage heart uptake of BMIPP did not have a significant correlation with LVEF (R = -0.299, NS). In contrast, there was a positive correlation between LVEF measured by multigated blood pool scintigraphy and BMIPP count density of the heart (R = 0.467, P = 0.005). Myocardial BMIPP washout rate also positively correlated with LVEF (R = 0.472, P = 0.005). In addition to these observations, there was a positive correlation between the BMIPP count density of the heart and myocardial BMIPP washout rate (R = 0.0543, P = 0.001). Thus, the BMIPP count density of the heart and myocardial BMIPP washout rate derived from BMIPP whole-body scintigraphy directly correlated with LVEF. However, the correlations between these parameters and LVEF were not strong enough to allow left ventricular dysfunction to be assessed precisely.

Adult↗

PubMed1994

[A longitudinal study of CMRGlu in dementia of Alzheimer type].

We studied the serial changes of CMRGlu in 6 patients with dementia of Alzheimer type. All patients demonstrated moderately severe dementia at the initial PET scan. Serial PET scans were performed at an interval of 12 to 24 months. Five of the 6 patients showed a deterioration of clinical symptoms at the second scan. The global CMRGlu serially decreased in all patients. An asymmetry of CMRGlu in both the frontal and parietal regions was observed at the initial PET scan, while the direction of asymmetry was preserved at the second PET scan. The ratios (frontal/parietal and parietal/striatum) of CMRGlu showed no interval change. Therefore, CMRGlu was considered to decrease progressively throughout the entire brain in patients with moderately severe dementia of Alzheimer type.

Alzheimer Disease↗

PubMed1994

[The partial volume effect correction for pulmonary mass lesions using a 68Ga/68Ge transmission scan in PET study].

We tried to correct the partial volume effect for pulmonary mass lesions using a 68Ga/68Ge transmission scan. Initially, a fundamental study was done using spherical phantoms and good results were obtained. Next, a clinical evaluation was performed on 28 pulmonary mass lesions ranging in diameter from 0.8 cm to 8.0 cm. The tissue fractions of the mass lesions were obtained by a 68Ga/68Ge transmission scan, where the tissue fraction in the back muscles was assumed to have a value of 1. The tissue fraction of the surrounding lung field was subtracted from that of each mass lesions, and the net tissue fraction was thereby obtained. When no correction was required, the tumor/muscle count ratio (TMR) became higher in proportion with an increase in the mass size. After performing a correction, however, no correlation was observed between them. This method was both easy to perform and reliable, and it is thus considered to be useful for overcoming the partial volume effect in pulmonary mass lesions, although an underestimation may still occur in cases with mass lesions either near the great vessels or the chest wall.

Gallium Radioisotopes↗

PubMed1994

[A useful method to evaluate 11C-methionine uptake using positron emission tomography: determination of the optimal scanning time for evaluation and a comparison between the tumor-to-muscle ratio and the distribution absorption ratio].

We determined the optimal scanning time for evaluating 11C-methionine uptake and then compared the usefulness of the tumor-to-muscle ratio (TMR) with the distribution absorption ratio (DAR) using positron emission tomography. Forty-two PET studies were performed to examine 42 tumorous lesions, 25 normal lung tissues, 23 normal bone marrow and 39 blood pool. In the 42 lesions examined, the TMR at 5, 10-20, 20-32 and 32-40 minutes after 11C-methionine injection, compared with that at 45-60 minutes, was 96 +/- 23%, 91 +/- 8.6%, 94 +/- 6.9% and 96 +/- 6.9%, respectively. A correlation study between the TMR and the DAR demonstrated good results in both the normal tissue (r = 0.96) and the tumorous lesions (r = 0.93). In conclusion, the 11C-methionine uptake can be evaluated at any time from 10 minutes after the injection of 11C-methionine and both the TMR and the DAR are considered to be useful methods for evaluating 11C-methionine uptake using positron emission tomography.

Absorption↗

PubMed1994

Hemolytic uremic syndrome without hemolytic anemia: a case report.

Hemolytic uremic syndrome (HUS) is characterized by microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. Most cases of HUS are caused by E. coli O157:H7 verotoxin. In the case reported here, diarrhea continued for twenty days after an E. coli 0157:H7 infection and was followed by acute renal failure and thrombocytopenia. Examination of percutaneous renal biopsy tissue showed typical HUS findings, e.g., mesangiolysis in glomeruli and thickening of capillary walls with prominent double outlines, but there was no indication of hemolytic anemia. LDH and haptoglobin, indications of hemolytic anemia, were in the normal range throughout the patient's clinical course. The patient's red blood cells had P1 antigen, which reportedly provides protection by adsorption of toxin into the red blood cells thereby preventing or limiting toxic damage to other organs. Therefore, we assumed that because of the expression of P1 antigen in this patient, the kidneys were not severely damaged and microangiopathic hemolytic anemia was thereby avoided.

Acute Kidney Injury↗

PubMed1994

[A case report of light and heavy chain deposition disease (IgG2 lambda)].

A 73-year-old male was admitted to the renal division of our hospital because of hypertension, proteinuria and bilateral pretibial edema. Eight years previously, he was diagnosed as being afflicted with interstitial pneumonia on the basis of a chest X-ray examination. Laboratory tests conducted during the current admission showed normocytic normochromic anemia, renal dysfunction and mild proteinuria. Total IgG was normal, but a high proportion of IgG2 was observed. M-protein in the serum was positive for both IgG lambda and Bence Jones protein (lambda type). A bone marrow biopsy showed the proportion of plasma cells to be 10.6%, but atypical cells were not found. We diagnosed the patient's condition as plasma cell dyscrasia. Light microscopy examination of a renal biopsy specimen showed moderate mesangial proliferation with a deposition of PAS-positive and Congo red negative materials in the mesangial area: nodular gomerulonephritis was seen in some glomeruli. Immunofluorescence revealed IgG and lambda light chains, strong linear staining along the glomerular basement membrane and tubular basement membrane and positivity in the mesangial area. Results of staining for IgA, IgM, fibrinogen and C3 were weakly positive in the mesangium area, while those for C4, Clq and free kappa were negative. Positive staining of IgG2 was seen by immunoperoxidase study, but the tissue was negative for IgG1, IgG3, IgG4. Electron microscopy demonstrated a dense granular deposition in the mesangial, subendothelial and peritubular area and a microfibrillar structure in the mesangial area. The diameter of the microfibrillar structure was 14 nm on the average.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

[Pre and post operative evaluation of the perfusion reserve by acetazolamide 99mTc-HMPAO SPECT in patients with chronic occlusive cerebral arteries: a comparative study with PET].

We studied the pre and post-operative perfusion reserve using Diamox 99mTc-HMPAO SPECT in 7 patients with chronic occlusive cerebral arteries and then compared the results with PET. STA-MCA anastomosis was performed on 5 patients, while a carotid endarterectomy was done on 2 patients. The cerebral blood flow, the vascular response to CO2 or Diamox, the oxygen extraction fraction and transit time (CBV/CBF) were measured by PET. In the pre-operative state, the visual evaluations for hypoperfusion area at rest were agreed in 5 out of 7 patients in HMPAO SPECT and PET studies. In the remaining 2 patients, hypoperfusion areas were only detected in the PET study. The pre-operative evaluation of perfusion reserve was agreed in 2 patients. In the remaining 5 patients, 3 patients showed definite positive(++) in PET and positive(+) in HMPAO SPECT, and one patient showed positive (+) in PET and negative (-) in HMPAO SPECT. The post-operative change of hypoperfusion areas was well agreed in HMPAO SPECT and PET studies. However, the change of perfusion reserve was underestimated in HMPAO SPECT compared with PET. In the semiquantitative and quantitative analyses, the count rate ratios (affected/unaffected side) in HMPAO SPECT were apparently higher than those of CBF in PET. The postoperative change of the count rate ratios in HMPAO SPECT were smaller than those of CBF in PET. There was no significant correlation between the change in the ratio of the HMPAO SPECT after the administration of Diamox and the oxygen extraction fraction, and it was thus thought to be impossible to predict the areas with an increased oxygen extraction fraction. Thus, Diamox HMPAO SPECT may underestimate the areas of hypoperfusion or decrease in perfusion reserve when compared with PET. We should consider these limitations in the evaluation of pre and post operative cerebral hemodynamics.

Acetazolamide↗

PubMed1994

Cell-mediated immune response in acute poststreptococcal glomerulonephritis.

To evaluate the role of cell-mediated immunity in acute poststreptococcal glomerulonephritis (APSGN), we identified the immune cell population infiltrating the glomeruli. Renal biopsies were obtained from 22 patients with APSGN, 16 with overt and 6 with asymptomatic disease, one to 30 days after onset. Samples of normal renal tissue were used as controls. Frozen sections were examined using monoclonal antibodies that recognize various leukocyte surface markers. Double staining for granulocytes and monocyte/macrophages (M phi) was performed using chloro-esterase staining and indirect immuno-alkaline-phosphatase staining with Leu M-5 sequentially. In overt APSGN, there was a substantial increase in the total number of granulocytes and M phi with a slight increase in T cells. Numbers correlated with time after onset, as more leukocytic infiltration was observed when the tissue was taken earlier. Furthermore, a significant positive linear correlation was seen between helper/inducer T cells and M phi (r = 0.86, p < 0.01). Helper T cells tended to be increased to a higher proportion during the early stage, while suppressor T cells remained constant throughout the course. Analysis with anti-proliferating cell nuclear antigen antibody revealed increased glomerular cell proliferation in the early phase of APSGN. In asymptomatic patients, the total number of leukocytes was less than in the overt patients, but the proportions of infiltrating cells were similar. These data suggest that M phi are important effector cells causing endothelial and mesangial cell proliferation in APSGN. M phi infiltration in the glomeruli appears to be mediated by complement-induced chemotaxis and probably be an antigen-specific event related to the delayed type hypersensitivity mediated by helper/inducer T cells.

Acute Disease↗

PubMed1994

[A case of advanced breast cancer with multiple lung metastases responding well to postoperative combined administration of doxifluridine (5'-DFUR) and tamoxifen].

A 72-year-old female with right breast cancer having multiple lung metastases was treated by combined administration of 5'-DFUR at 800 mg/day, and tamoxifen, at 20 mg/day, after standard radical mastectomy. Plain chest X-ray and computed tomography examinations have shown complete disappearance of the multiple lung tumor since the therapy. No serious side effects have been observed during the treatment course, and there has been no definite evidence of tumor recurrence.

Adenocarcinoma, Papillary↗

PubMed1994

Kinetics of iodine-123-BMIPP in patients with prior myocardial infarction: assessment with dynamic rest and stress images compared with stress thallium-201 SPECT.

UNLABELLED: Myocardial kinetics of 123I-labeled 15-(p-iodophenyl)3R, S-methylpentadecanoic acid (BMIPP) were evaluated with dynamic SPECT, and stress and rest BMIPP images were directly compared in conjunction with stress 201Tl. METHODS: We studied 26 patients with prior myocardial infarction. Two minutes after injection of BMIPP, dynamic data acquisition with a three-headed SPECT was started and continued for 12 min. Conventional SPECT images were obtained at 20 min and 3 hr after injection. On a separate day, exercise, stress 201Tl SPECT was performed at 10 min and 3 hr after injection. Exercise stress-BMIPP imaging was performed in 15 of the patients, and static SPECT images were obtained. RESULTS: With dynamic SPECT, early clearance of BMIPP from the myocardium was observed in the segments with reversible 201Tl defects, suggesting enhanced contribution of backdiffusion from BMIPP. In myocardial segments with reversible 201Tl defects, 20-min BMIPP images showed a higher frequency of reduced uptake when compared to 3-hr 201Tl (90/163) imaging. CONCLUSION: With BMIPP dynamic SPECT, an enhanced contribution of backdiffusion in the early phase from ischemic myocardium was suggested. When exercise stress BMIPP images were obtained, a more severe defect was observed than on rest BMIPP and stress 201Tl imaging, possibly due to decreased coronary blood flow and impaired fatty acid uptake induced by ischemia during exercise.

Exercise Test↗

PubMed1994

[Linealization correction for acetazolamide (Diamox) 99mTc-HMPAO SPECT image--a comparative study with PET].

We attempted to make a linearization correction for the acetazolamide 99mTc-HMPAO SPECT image. These results were compared to those by PET using the H2(15)O-bolus injection method. The subjects consisted of eleven patients with cerebrovascular diseases. The SPECT images were obtained by the double injection method in the resting state and after an administration of acetazolamide (1 g). Linearization correction was performed according to the Lassen's method. In this study, three different methods were compared, namely fixed Fr and alpha (70 ml/min/100 ml and 1.08), individual determination of Fr and alpha based on PET data, and finally the normalization of the two scan for administered dose, fixed Fr and alpha (50 ml/min/100 ml and 1.5). The corrected count rate ratios of the 99mTc-HMPAO SPECT images were correlated well with the values of regional cerebral blood flow measured by PET in all methods. Therefore, the first method was considered to be a simple and reliable one. In the last method, the relative change of cerebral blood flow after the administration of acetazolamide was calculated. The means of the percentage increase of cerebral blood flow were in good accord between 99mTc-HMPAO SPECT and PET. However, they showed much discrepancy when individually compared.

Acetazolamide↗

PubMed1993

Malignant duodenocolic fistula: report of a case and considerations for operative management.

Malignant duodenocolic fistula is a rare complication of gastrointestinal malignancy. We present herein the case of a 34-year-old female in whom a large duodenocolic fistula was caused by advanced transverse colonic carcinoma. Right hemicolectomy combined with pancreaticoduodenectomy enabled en bloc resection of the tumor, and the patient has been free of disease for 1 year and 8 months postoperatively. A review of the international literature, including 33 cases reported in Japan, indicates that if the disease is curable, the treatment of choice is right hemicolectomy with pancreaticoduodenectomy, whereas if it is not curable but locally resectable, the best palliation appears to be right hemicolectomy with partial duodenectomy to include the fistulous tract. Dehiscence of the duodenal wound closure associated with partial duodenectomy can be prevented by using the mucosal or serosal patch techniques with intestinal loops. These therapeutic principles are also applicable for colonic carcinoma which massively involves the duodenum without fistula formation.

Adenocarcinoma↗