Search PubMed⌕ Search

Biomedical subjects

M Tamura

Publications and source records attributed to M Tamura.

At least 415 records · Page 23Linked to original sources
PubMed1996

[Clinical evaluation of hepatitis C virus RNA quantification by competitive reverse-transcription PCR].

We have quantified the hepatitis C virus (HCV) RNA by competitive reverse-transcription PCR method (Amplicor) HCV quantification monitor kit) in sera with positive HCV antibody measured by means of the second generation HCV antibody assay. Among the visitors to PL Tokyo Health Control Center for their health examination and the patients to National Defense Medical College Hospital, 123 HCV antibody-positive cases were examined. A positive but low correlation between the amount of HCV-RNA and the titer of HCV antibody (r = 0.508, p value < 0.0001) was obtained. HCV-RNA was not detectable in 19 HCV antibody-positive cases. Among them, 10 cases showed normal ALT values. In the cases with more than 1000 copies/ml of HCV-RNA, the greater the amount of HCV-RNA the higher ALT values were observed, while the titer of HCV antibody was not correlated to ALT. This study demonstrated the dissociation and low correlation between HCV-RNA amount and antibody-titers in some patients, which may recommend direct quantification of RNA for clinical evaluation of the patients with positive-HCV antibody. The quantification of HCV-RNA by such rapid and simple methods can be applicable for the determination of HCV-RNA amount in routine laboratory works.

Hepacivirus↗
PubMed1996

Independent thallium-201 accumulation and fluorine-18-fluorodeoxyglucose metabolism in glioma.

UNLABELLED: SPECT with 201TI is an effective procedure for evaluating the malignancy of glioma. Our goal was to investigate the diagnostic relevance of both 201TI SPECT and [18F]fluorodeoxyglucose (FDG) PET and the relation between 201TI uptake and glucose metabolism in glioma using comparative SPECT and PET studies. METHODS: Thallium-201 SPECT and FDG dynamic PET studies were performed in 20 patients with untreated glioma (5 with glioblastoma, 5 with anaplastic glioma, 10 with low-grade glioma). Thallium-201 uptake in the tumor was estimated using the 201TI index, defined as the ratio of 201TI uptake in the tumor to that in the contralateral normal brain on SPECT images obtained 15 min after intravenous injection. We measured regional glucose metabolic parameters, including rate constants and regional cerebral metabolic rate of glucose utilization (rCMRgl), in the tumor. We then compared the regional 201TI index and glucose metabolic parameters with the histologic characteristics, malignancy and computed tomographic/ magnetic resonance imaging findings. In addition, we investigated the correlation between the 201TI index and glucose metabolic parameters. RESULTS: Thallium-201 SPECT showed abnormal 201TI uptake in all patients with glioblastoma and anaplastic glioma. Thallium-201 indices of glioblastoma (202.6 +/- 22.1%) and anaplastic glioma (176.6% +/- 26.6%) were significantly higher than that for low-grade glioma (106.7% +/- 13.8%). The rCMRgl value of glioblastoma (17.6 +/- 3.5 mumole/100 g/min) was also significantly higher than that for low-grade glioma (10.8 +/- 4.5 mumole/100 g/min), although rCMRgl showed a large variability in both high- and low-grade glioma. Rate constants of FDG kinetics had no correlation with histological grade of glioma. Some patients with high-grade glioma, however, showed false-negative results with FDG-PET because of high normal brain uptake of FDG. Conversely, most low-grade glioma could not be localized by 201TI SPECT. There was no correlation between the 201TI index and glucose metabolic parameters. CONCLUSION: Thallium-201 indices and rCMRgl values for glioblastoma were higher than those for low-grade glioma. Thallium-201 uptake in the tumor may be independent of increased glucose transport or metabolism. Thallium-201 SPECT and FDG-PET are complementary in the diagnosis of glioma, although 201TI SPECT is more significantly correlated with the malignancy of glioma.

Brain Neoplasms↗
PubMed1996

[Pathogenesis-screening tests for liver dysfunction in the asymptomatic patients with elevated ALT values and their diagnostic efficacies in primary care medicine].

We have evaluated the diagnostic efficacies of ultrasonography and hepatitis C virus (HCV) antibody measurement to differentiate pathogenesis of liver dysfunction in the asymptomatic adults with elevated ALT value. Among 4256 visitors to PL Tokyo Health Control Center for their health examination, 463 cases (11%) showed abnormal liver function including elevation of ALT value. Ultrasonography and HCV antibody measurement using the second generation reagent had been applied to 362 cases in order to screen the etiology of liver dysfunction. The ultrasonography succeeded to establish the diagnosis of fatty liver in 137 cases (38%) and 41 cases (11%) demonstrated positive HCV antibody. There were 4 cases with positive HBs antigen, however, it was found that their abnormal liver function was attributed to other etiology such as fatty liver and alcoholic liver dysfunction rather than chronic type B hepatitis. HCV antibody-positive cases showed higher levels of total protein, ZTT, AST, ALT, and lower levels of albumin, A/G, total cholesterol, triglyceride, gamma-GT and cholinesterase value than other cases. HCV antibody titers were not correlated to hepatic parenchymal damage estimated by ALT or cholinesterase value. Only a little correlation was observed between HCV antibody titers and HCV-RNA amounts determined by the competitive reverse transcription-polymerase chain reaction (RT-PCR) method. These results indicate sufficient diagnostic efficacies of ultrasonography and HCV antibody measurement for a pathogenesis differentiation in the asymptomatic patients with liver dysfunction, and these examinations should be employed as the first-step screening tests for the etiology determination of liver diseases in the primary care medicine.

Alanine Transaminase↗
PubMed1996

[Renovascular hypertension associated with antiphospholipid antibodies in a woman with systemic lupus erythematosus].

Systemic lupus erythematosus (SLE) patients, especially those with antiphospholipid antibodies, have a high incidence of arterial and venous thrombotic manifestations. However, renovascular hypertension (RVH) has been rarely reported in these patients. We describe here a 49-year-old female with antiphospholipid antibodies, complicated with RVH and presenting with sudden onset of severe hypertension, headache and nausea. She had experienced phlebitis and arterial thrombosis of the right leg. At the age of 38 years, she was diagnosed as SLE and steroid therapy was started, but she had poor drug compliance and irregularly visited our clinic. On admission, hypertension was recognized and abdominal bruit was audible on physical examination. Serological findings were compatible with SLE. She was also found to have IgG anti-cardiolipin antibody and lupus anticoagulant. Peripheral plasma renin activity (PRA) was elevated, and captopril test showed hyper-response of PRA with lowering of blood pressure. Renal echography and scintigram showed a small and poorly perfused right kidney. Selective angiography demonstrated a severe stenosis of the right renal artery at origin. A stenosis at the origin of both the superior mesenteric artery (SMA) and celiac trunk was also detected. Percutaneous transluminal angioplasty was performed, achieving successful dilatation of the right renal artery and SMA, whereas the attempt to insert the catheter into the celiac trunk was unsuccessful. After this procedure, abdominal bruit has not been audible. Following the initiation of steroid pulse therapy combined with heparin and dipyridamole, her blood pressure was gradually depressed and the test for lupus anticoagulant became negative. Therefore, RVH of this patient is thought to be associated with antiphospholipid antibodies.

Antibodies, Antiphospholipid↗
PubMed1996

[Impaired glucose tolerance and branch retinal vein obstruction].

Impaired glucose tolerance (IGT) has been one of the risk factors of Branch Retinal Vein Obstruction (BRVO). In order to study the contribution of IGT to the pathogenesis of BRVO, the 75 gram oral glucose tolerance test and immunoreactive insulin (IRI) measurement were investigated in 180 BRVO patients. IGT was found in 103 patients, and about 40% of these patients showed hyperinsulinemia and secondary insulin resistance. This result suggests that IGT with BRVO are in a state of hyperinsulinemia and hyperglycemia and hyperinsulinemia play an important role in thrombogenesis, such as injury to the venous endothelial cells.

Glucose Intolerance↗
PubMed1996

[Awareness of health and welfare planning for elderly and methods to increase awareness: based on social marketing].

To clarify the socio-psychological factors affecting awareness of health and welfare planning for the elderly, a survey of community residents was performed in the Tokyo metropolitan area. The results obtained were as follows: 1. There were three factors which affected awareness concern about health and welfare services for the elderly as a social issue: concern about the local community; and concern about the local government. 2. Two other factors which did not affect the level of awareness were: anxiety about the health and welfare services for the elderly as a personal issue; and having personal experience of nursing care. From these results, a method to increase awareness was studied based on social marketing methods. Two primary target groups for increasing awareness were identified. One target was people who have the socio-psychological factors described above. Another target was people who have the potential need for health and welfare services but who were not aware of it. That is, they have relatively high anxiety about health and welfare services for the elderly as a personal issue and have personally experienced nursing care. The method of approach for these targets were studied. For the first group, the amount of the information available seemed to be important because these persons are ready to recognize the need for planning. Therefore, efficient information channels should be selected. For the second group, approaches that generate greater consumer participation by presenting this as an efficient method for solution of the problem should be adopted.

Adult↗
PubMed1996

Adhesion and endocytosis of calcium oxalate crystals on renal tubular cells.

The present investigation was designed to study interactions between Madin-Darby canine kidney (MDCK) cells and calcium oxalate monohydrate (COM) crystals and to clarify the significance of these crystal-cell interactions in stone pathogenesis. MDCK cells cultured in the presence of COM crystals showed a time-dependent uptake of crystals; this was specific for COM crystals. In the dynamic model system designed to study these phenomena under more physiological conditions, COM crystals adhered to the cell surface and were subsequently internalized. In this endocytotic process, the microvilli of the cell appeared to play an important role. The observation by scanning electron microscopy of complexes consisting of aggregated COM crystals and cell debris led us to speculate that adhesion and endocytosis of crystals might provide the calculus nidus for aggregation and retention of crystals in the renal tubule. Furthermore, glycosaminoglycans and the macromolecular fraction of human urine were shown to have the ability to inhibit the cellular uptake of crystals. Evidence that similar processes may also occur in vivo was obtained using an experimental stone model in rats. Our experiments revealed that most of the COM crystals adhered to the tubular cells and some crystals were endocytosed by the cell. Thus, these crystal-cell interactions might be one of the earliest processes in the formation of kidney stones. Further elucidation of the mechanism and the regulatory factors involved in this process may provide new insight into stone pathogenesis.

Adhesiveness↗
PubMed1995

Molecular cloning and expression of megakaryocyte potentiating factor cDNA.

The human megakaryocyte potentiating factor (hMPF) has been previously purified from a culture supernatant of human pancreatic cancer cells HPC-Y5 (Yamaguchi, N., Hattori, K., Oh-eda, M., Kojima, T., Imai, N., and Ochi, N. (1994) J. Biol. Chem. 269, 805-808). We have now isolated hMPF cDNA from a HPC-Y5 cDNA library using polymerase chain reaction and plaque hybridization methods. The hMPF cDNA encodes a polypeptide consisting of 622 amino acids, including a signal peptide of 33 amino acids, and with a deduced molecular mass of 68 kDa, although HPC-Y5 cells secrete a 33-kDa form of hMPF. Human MPF does not show any significant homology with other previously described sequences. The cDNA was expressed in COS-7 and Chinese hamster ovary (CHO) cells, and megakaryocyte potentiating activity was detected in their culture supernatant. The COS-7 cells secreted only a 33-kDa recombinant hMPF, whereas an additional 30-kDa form was detected in the culture medium of CHO cells. The 33-kDa rhMPF purified from CHO cells showed megakaryocyte potentiating activity, but not the purified 30-kDa rhMPF. The difference in structure and activity between the 33- and 30-kDa forms of hMPF was ascribed to the existence in the 33-kDa form of the C-terminal 25 amino acid residues.

Amino Acid Sequence↗
PubMed1995

Missense mutation of the beta-cardiac myosin heavy-chain gene in hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy occurs as an autosomal dominant familial disorder or as a sporadic disease without familial involvement. We describe a missense mutation of the beta-cardiac myosin heavy chain (MHC) gene, a G to T transversion (741 Gly-->Trp) identified by direct sequencing of exon 20 in four individuals affected with familial hypertrophic cardiomyopathy. Three individuals with sporadic hypertrophic cardiomyopathy, whose parents are clinically and genetically unaffected, had sequence variations of exon 34 of the alpha-cardiac MHC gene (a C to T transversion, 1658 Asp-->Asp, resulting in FokI site polymorphism), of intron 33 of the alpha-cardiac MHC gene (a G to A and an A to T transversion), and also of intron 14 of the beta-cardiac MHC gene (a C to T transversion in a patient with Noonan syndrome). Including our case, 30 missense mutations of the beta-cardiac MHC gene in 49 families have been reported thus far worldwide. Almost all are located in the region of the gene coding for the globular head of the molecule, and only one mutation was found in both Caucasian and Japanese families. Missense mutations of the beta-cardiac MHC gene in hypertrophic cardiomyopathy may therefore differ according to race.

Adolescent↗
PubMed1995

Role of age on transmitral flow velocity patterns in assessing left ventricular diastolic function in normal infants and children.

This study demonstrated that both peak E and flow velocity integral of early diastole increased to reach the older children's values by 36 months of age and leveled off thereafter, whereas both peak A and flow velocity integral of atrial contraction had little change. These results suggest that age-related changes in E wave reflect the maturational or developmental alterations in LV diastolic properties, especially in the relaxation process.

Adolescent↗
PubMed1995

Changes in transmitral and pulmonary venous flow patterns in the first day of life.

The purpose of this study was to see the relationship between changes in pulmonary venous flow velocities and those in transmitral flow velocities during the first day of life. A serial Doppler echocardiography was performed in 24 normal neonates at 2, 12, and 24 hours of age. The size of the ductus arteriosus was 4.3 +/- 0.5 mm at 2 hours and 2.1 +/- 0.7 mm at 12 hours, and closed in 21 of 24 neonates at 24 hours. The peak systolic pulmonary venous flow (peak S), peak diastolic pulmonary venous flow (peak D), peak D/S, peak velocity at early diastolic filling (peak E), and peak E/A, which were high at 2 hours, decreased significantly at 12 hours but remained constant thereafter. The size of the ductus arteriosus was found to be correlated with peak S, peak D, and peak D/S. There was a direct correlation between peaks E and D (r: 0.64, p < 0.01) as well as a direct correlation between peaks E/A and D/S (r: 0.36, p < 0.05). These results indicate that the diastolic pulmonary venous flow is determined by the same factors that influence the transmitral flow. These waveforms may reflect the increase in pulmonary circulatory volume by left-to-right shunting through the ductus arteriosus.

Blood Flow Velocity↗
PubMed1995

Calcified astrocytoma of the amygdalo-hippocampal region in children.

Three pediatric cases of temporal lobe seizure due to calcified glioma of amygdalo-hippocampal region are described. Computed tomography and magnetic resonance imaging showed dense calcification with no postcontrast enhancement in the amygdalo-hippocampal region. Positron emission tomography showed low oxygen metabolism, low glucose metabolism, hypermetabolism of amino acids, and low regional cerebral blood flow in the tumors. Single photon emission computed tomography showed a high accumulation of 201Tl chloride and 123I-isopropyl iodoamphetamine in one tumor, but otherwise low radioisotope uptake. These studies indicated low-grade malignancies. The patients were treated by partial tumor removal and radiotherapy. Histological examination of the tumor specimens showed astrocytoma with interstitial calcification. One patient died due to tumor recurrence, while the others are doing well with minimal seizure. We recommended temporal lobectomy in similar cases to achieve complete remission.

Adolescent↗
PubMed1995

Laser vaporization of the ovarian surface in polycystic ovary disease results in reduced ovarian hyperstimulation and improved pregnancy rates.

OBJECTIVE: Our purpose was to examine the efficacy of laser vaporization of the ovarian surface in polycystic ovary disease to reduce repeated ovarian hyperstimulation syndrome and thereby improve pregnancy outcome. STUDY DESIGN: Twenty-six infertile patients with polycystic ovary disease who previously had ovarian hyperstimulation syndrome after stimulation with human menopausal gonadotropin and who failed to conceive were studied. All patients were treated by potassium titanyl phosphate and neodymium-yttrium-aluminum-garnet laser and evaluated. Patients not ovulating spontaneously after vaporization were treated with either clomiphene citrate or human menopausal gonadotropin. RESULTS: After vaporization spontaneous ovulation was confirmed in six patients. For ovulation induction three patients received clomiphene citrate and 17 received human menopausal gonadotropin. Of the patients treated with human menopausal gonadotropin, mild ovarian hyperstimulation syndrome was found in three patients, and the incidence of ovarian hyperstimulation syndrome decreased significantly. Pregnancy was confirmed in 19 of 26 patients. CONCLUSION: Laser vaporization is promising for the prevention of ovarian hyperstimulation syndrome and improving pregnancy outcome in patients with polycystic ovary disease who have previously had ovarian hyperstimulation syndrome.

Adult↗
PubMed1995

NS-3 (CG3703), an analog of thyrotropin-releasing hormone, ameliorates cognitive impairment in rats.

The effects of thyrotropin-releasing hormone (TRH) and its analog, N-[[(3R,6R)-6-methyl-5-oxo-thiomorpholinyl] carbonyl]-L-histidyl-L- prolinamide tetrahydrate (NS-3, CG3703) on disturbance of memory of a passive avoidance response (PAR) and an escape response in rats were investigated. NS-3 improved amnesia caused by scopolamine, electroconvulsive shock (ECS), and cycloheximide (CXM), but TRH improved only the ECS-induced amnesia. NS-3 reversed learning deficits caused by hypercapnia, but TRH had no effect. These differences in the effect between NS-3 and TRH may be due to their biological half-life in rat plasma. These results suggest that NS-3 possesses more potent antiamnestic effects than TRH in rats.

Amino Acid Sequence↗