Biomedical subjects

T Imamura

Publications and source records attributed to T Imamura.

755 records · Page 42Linked to original sources

PubMedDate not supplied

Occipital glucose metabolism in dementia with lewy bodies with and without Parkinsonism: a study using positron emission tomography.

Reduction of glucose metabolism in the occipital lobe is reported in dementia with Lewy bodies (DLB) and Parkinson's disease. If dysfunction of the nigrostriatal system is responsible for occipital hypometabolism, (1) DLB patients with parkinsonism would show a lower occipital metabolism than do patients without parkinsonism, and (2) DLB patients without parkinsonism would show an occipital metabolism comparable to those of normal subjects and patients with Alzheimer's disease (AD). To examine these hypotheses, we studied the regional cerebral metabolic rate of glucose (rCMRglc) in patients with a clinical diagnosis of DLB or AD, using (18)F-fluorodeoxyglucose and positron emission tomography. The subjects consisted of 15 DLB patients with parkinsonism, 7 DLB patients without parkinsonism and 7 AD patients without parkinsonism. The medial and lateral occipital rCMRglc was significantly lower in the DLB patients without parkinsonism than in the AD patients. There were no significant differences in occipital metabolic rates between the DLB groups with and without parkinsonism. DLB patients without parkinsonism showed a significant reduction of occipital glucose metabolism which is comparable with that of DLB patients with parkinsonism. The neurobiological bases of occipital hypometabolism in DLB may be pathological processes in the brainstem or basal forebrain structures other than the nigrostriatal system.

Aged↗

PubMedDate not supplied

Procedural memory in patients with mild Alzheimer's disease.

Motor, perceptual, and cognitive skill learning abilities of mild Alzheimer's disease (AD) patients were compared to sex-, age-, and education-matched controls. We excluded patients who were unable to perform each skill learning task with a predetermined criterion. In those who completed the task, skill learning was as good as in normal controls. On the cognitive and perceptual skill learnings, some of the AD patients, whose cognitive but not declarative memory functions were more severely impaired than in those who completed the whole session, failed to complete the task, while all patients could complete the motor task. These results support that view that patients with mild AD can acquire motor, perceptual, and cognitive skills and that the neural system subserving procedural skill is not related to the neural systems for declarative memory.

Aged↗

PubMedDate not supplied

The disturbances of object vision and spatial vision in Alzheimer's disease.

Thirty-one patients with mild-to-moderate Alzheimer's disease (AD) underwent a test battery of complex visual tasks. We assessed the scores using a principal-factor analysis to elucidate the underlying deficits. There were three independent factors: The first factor included the tasks of identifying and comparing forms of visual stimuli. The second factor consisted of digit span and digit symbol tasks, and the third factor consisted of a specified visual counting task. We considered these three factors as representing the dysfunctions of object recognition, general attention and spatial recognition, respectively. These results underline the disturbances of the two visual systems, object vision and spatial vision, in early-AD patients.

Aged↗

PubMedDate not supplied

Elevated serum c-erbB-2 protein levels in patients with pancreatic cancer: correlation to metastasis and shorter survival.

Overexpression of the c-erbB-2 proto-oncogene has been shown to correlate with relapse and poor prognosis in adenocarcinomas of the breast and stomach. In pancreatic cancer, c-erbB-2 overexpression has been demonstrated using immunohistochemistry, but the relationship between serum c-erbB-2 level and clinical data has not been fully evaluated. In this study, serum c-erbB-2 protein levels were measured in 100 patients with pancreatic adenocarcinomas and in 9 patients with mucin-producing tumors. Immunohistochemical studies for c-erbB-2 protein were performed in 36 patients and 4.0 U/ml in healthy controls (p < 0.001). The positive rate for serum c-erbB-2 was 34% (37/109) in patients with pancreatic cancer and 0% (0/66) in patients with gallstones and in healthy controls (p < 0.001). Immunohistochemical study disclosed that the positive staining rate was 28% (8/29) in common ductal adenocarcinoma specimens, 43% (3/7) in metastasis specimens, and 75% (3/4) in mucin-producing tumor specimens. Clinical evaluation revealed that 59% (22/37) of serum c-erbB-2-positive patients and 33% (24/72) of negative patients had liver or peritoneal metastases (p < 0.01). The mean survival time was 154 days in the c-erbB-2-positive group and 220 days in the negative group (p < 0.05). We suppose that c-erbB-2 is related to metastasis and progression of the disease in patients with advanced pancreatic cancer.

Adenocarcinoma, Mucinous↗

PubMedDate not supplied

The effects of oral RNA and intraperitoneal nucleoside-nucleotide administration on methicillin-resistant Staphylococcus aureus infection in mice.

The effects of oral RNA and intraperitoneal nucleoside-nucleotide mixture administration on methicillin-resistant Staphylococcus aureus (MRSA) strain 8985N infection were studied in mice. BALB/c mice were fed a nucleic acid-free diet or nucleic acid-free diet supplemented with 0.5% or 2.5% ribonucleic acid (RNA) for 30 days. Nucleoside-nucleotide mixture or saline (control) was intraperitoneally administered daily to these rats except for the 2.5% RNA group, which received saline only. On the 10th day of this treatment, the mice were inoculated intravenously with the viable MRSA organisms. Susceptibility to the MRSA was determined by animal survival and recovery of the MRSA from the organs. The survival rates in the three groups that were administered saline were 29%, 35%, and 40% for nucleic acid-free diet, 0.5% RNA, and 2.5% RNA groups, respectively, whereas in the two groups that received the nucleoside-nucleotide mixture the rates were 69% for the nucleic acid-free diet group and 55% for 0.5% RNA group. The susceptibility of the mice to the MRSA challenge was not affected by dietary RNA, which indicates the ineffectiveness of oral RNA. The combined survival rate in the two nucleoside-nucleotide groups (64%) was statistically different (p < .01) from that in the three saline groups (34%). There was a greater reduction in viable organism recovery in the kidney and spleen of the surviving mice that had been administered the nucleoside-nucleotide mixture than in those administered saline.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMedDate not supplied

Distribution of the carbohydrate antigens, DU-PAN-2 and CA19-9, in tumors of the lung.

AIMS AND BACKGROUND: The carbohydrate chains of malignant cells appear to be related to oncofetal differentiation. The serum levels of CA19-9 have been reported to be evaluated in some patients with lung carcinomas, however, the distribution of carbohydrate antigens were not precisely described. We have investigated in this study the distribution of DU-PAN-2 and CA19-9 antigens in lung tumors. METHODS: Ninety five specimens of lung tumors were selected from surgical specimens. The expression of DU-PAN-2 and CA19-9 were studied by immunohystochemical techniques. The relationship between the expression of these antigens and the classification or the differentiation degree of the tumors were examined. RESULTS: DU-PAN-2 or CA19-9 antigens were detected in 41 (54%) and 45 (59%) cases of the 76 malignant epithelial tumors investigated. These antigens were detected in all types of malignant epithelial tumors, including squamous cell carcinomas, where they were mainly localized to the entire cell surface of malignant cells. In adenocarcinomas, large cell carcinomas and small cell carcinomas, however, these antigens were commonly detected both on the cell membrane and in the cytoplasm. There was positive correlation between the degree of differentiation and DU-PAN-2, but not CA19-9 expression. Among the non-epithelial tumors investigated, those antigens were detected in pulmonary blastomas but not in mesotheliomas. CONCLUSIONS: Immunohistochemical studies for DU-PAN-2 and CA19-9 are useful for defining characteristics of the lung tumors. DU-PAN-2 could be a marker for differentiating between malignant epithelial tumors and mesotheliomas.

Adenocarcinoma↗

PubMedDate not supplied

Intrapericardial instillation of OK-432 for the management of malignant pericardial effusion: report of three cases.

Three patients with cardiac tamponade caused by malignancy were treated by pericardiocentesis with intrapericardial OK-432 instillation. The underlying disease was adenocarcinoma of unknown origin, breast cancer and multiple myeloma. Under electrocardiographic monitoring, a polyethylene catheter with several side holes was inserted into the pericardial sac, and after a maximal volume of fluid was withdrawn, 5 KE of OK-432 diluted in 20 ml of saline was instilled through the catheter. All the patients who received intrapericardial OK-432 therapy obtained complete control of pericardial effusion for more than 30 days. The side effects were fever, chills and chest pain which were easily controlled by antipyretics.

Adenocarcinoma↗

PubMedDate not supplied

Role of functional brain imaging in the evaluation of vascular dementia.

There are various types of underlying damage to tissue and vessels in vascular dementia, including (1) single or multiple infarcts that involve association and limbic cortices, (2) small subcortical infarcts disrupting cortico-subcortical circuits, and (3) white matter lesions. The clinical picture of vascular dementia varies, and the role of functional brain imaging of cerebral blood flow and metabolism would be expected to be different among subtypes of vascular dementia. The role and value of functional brain imaging is limited for cortical infarcts; it is very valuable in assessing the impact on cortical function for small subcortical infarcts; and it is probably useful for evaluating white matter lesions, but this needs to be determined in further studies. At least in research of vascular dementia, functional brain imaging criteria should be included for proper patient selection. Careful studies using functional imaging tools in a well-characterized patient population will be needed.

Alzheimer Disease↗

PubMedDate not supplied

Gene knockout mice in the study of parturition.

OBJECTIVE: To review recent studies of parturition control in mice with relevance to understanding the control of human parturition. METHODS: Assimilation of published studies of gene knockout mice with mutations in neuropeptides, prostaglandin synthetic enzymes and receptors, and other molecules implicated in parturition. RESULTS: The central role of prostaglandins in murine labor is demonstrated by mice with gene mutations at multiple levels of the prostaglandin synthetic pathway. In addition, novel molecules such as steroid 5 alpha-reductase are found to play an essential role in the progression of labor. Surprisingly, deficiency of neuropeptides such as oxytocin and corticotropin-releasing hormone have little effect on parturition. CONCLUSION: Molecular genetic analyses in mice provide an efficient way to define molecules critical for murine parturition. Extrapolation of the importance of these molecules to human parturition provides the next challenge.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMedDate not supplied

Isolation, identification, and plaque titration of parvovirus from Muscovy ducks in Japan.

Muscovy ducks (Cairina moschata) showed abnormal feathering, leg weakness, and high mortality. A virus was isolated from these ducks after several blind passages in embryonating Muscovy duck eggs. The isolate was resistant to chloroform, to pH 3.2, and to 65 C for 30 min. Electron microscopy showed that the isolate was an icosahedral and nonenveloped virus 20-22 nm in diameter. The isolate reacted with an antiserum against a goose parvovirus in agar gel precipitation tests. After 15 passages of the isolate in embryonating eggs, the isolate was adapted to Muscovy duck embryo fibroblasts. The adapted virus developed cytopathic effects and made clear plaques on sheets of the fibroblasts. When 5-iodo-2-deoxyuridine was added to the culture medium, virus growth was inhibited. From the data shown above, the isolate was identified as a goose parvovirus.

Animals↗

PubMedDate not supplied

Expression and distribution of transforming growth factor-beta and decorin during fracture healing.

To study interactions between TGF-beta and decorin, we experimentally induced femoral fracture in rats and immunohistologically examined changes in the distribution of TGF-beta and decorin in the femur 3, 7 and 14 days after fracture. In the areas where endochondral ossification occurred, decorin was detected during differentiation of mesenchymal cells into proliferating chondrocytes, while no TGB-beta was observed during same period. Once chondrocytes had hypertrophied, decorin was no longer observed, while the matrix around the hypertrophic chondrocytes was positively stained for TGB-beta. The disappearance of decorin, almost simultaneously accompanied by the appearance of the active type TGB-beta, suggests that decorin regulates the actions of TGB-beta.

Animals↗

PubMedDate not supplied

Long-acting nicardipine for elderly hypertensive patients: effect on diurnal variation of blood pressure.

The effect of long-acting nicardipine tablets on diurnal variation of blood pressure was compared with that of standard nicardipine tablets and long-acting nifedipine tablets by 24-hour ambulatory blood pressure monitoring in 35 patients with hypertension. Long-acting nicardipine decreased systolic blood pressure in each age group, and there was no difference in its anti-hypertensive effect when compared with the other two drugs. All three drugs had no effect on the amplitude of daily blood pressure variation, and all three drugs decreased the baseline blood pressure in each age group when compared with untreated patients. In addition, no change was observed in the decrement of baseline blood pressure after switching from the other two drugs to long-acting nicardipine. Long-acting nicardipine had less effect on diurnal blood pressure variation than standard nicardipine tablets, which are administered three times daily. In each age group, long-acting nicardipine also more effectively inhibited the increase in cardiac work resulting from the morning rise phenomenon when compared with standard nicardipine tablets. These findings suggest that long-acting nicardipine may be a more useful preparation for the treatment of essential hypertension, particularly in elderly patients.

Aged↗

PubMedDate not supplied

Nucleoside-nucleotide mixture and its components and response to methicillin-resistant Staphylococcus aureus infection in mice.

The effects of a nucleoside-nucleotide mixture and its individual components on response to methicillin-resistant Staphylococcus aureus (MRSA) strain 8985N were studied in mice. BALB/c mice were fed a nucleic-acid-free 20% casein diet and intraperitoneally administered a nucleoside-nucleotide mixture, its individual components (inosine, GMP2Na, uridine, thymidine, cytidine), or saline for 30 days. On the 10th day of this treatment, the mice were inoculated intravenously with the viable MRSA organisms. By the 20th day after inoculation, mice in the saline group showed 33% survival, whereas mice in the nucleoside-nucleotide mixture group showed 75% survival. The survival rates in the inosine (62%), GMP2Na (57%), uridine (54%), cytidine (50%), and thymidine (46%) groups were not significantly different. The survival rates of the individual-component groups tended to be higher than that of the saline group, but this was not statistically different. Furthermore, there was a greater reduction in viable organism recovery in the spleen and kidney of the surviving mice in the component groups than in the saline group. However, the survival rates in the individual-component groups did not exceed that of the nucleoside-nucleotide mixture group. This study suggests that intraperitoneal administration of a nucleoside-nucleotide mixture appears to be important in producing a high survival rate after challenge with MRSA. The effect cannot be achieved with the specific components of the mixture administered individually.

Animals↗

PubMedDate not supplied

Histochemical and immunohistochemical study on the skin of patients with ossification of the posterior longitudinal ligament in the cervical spine.

We present an immunohistochemical study on extracellular matrix (ECM), decorin, in the epidermis and dermis of patients with ossification of the posterior longitudinal ligament (OPLL) to clarify the abnormality in the extracellular matrix of the skin of OPLL. Localization of decorin and TGF-beta in the skin was studied. All patients with OPLL showed a diffuse strong staining of decorin in the entire epidermal layer. The epidermis was also positive for TGF-beta antibody staining. Patients with cervical spondylotic myelopathy showed weak or no staining of decorin. Abnormality in the regulating system of TGF-beta may be involved in the precipitation of extracellular matrix.

Aged↗

PubMedDate not supplied

Effect of transforming growth factor-beta on fibroblasts in ossification of the posterior longitudinal ligament.

We studied the immunohistochemical localization of TGF-beta in the ligament tissue of patients with ossification of the posterior longitudinal ligament (OPLL), and the effects of TGF-beta on cultured cells derived from the spinal ligament of patients with OPLL. ALP activity in the cultured cells was also examined. TGF-beta was present in the ossified matrix and in the chondrocytes in cartilaginous areas adjacent to OPLL. ALP activity was high in the cultured cells of OPLL patients. Exogenous TGF-beta inhibited proliferation in the OPLL cells but promoted proliferation in control cells. These results suggest that the spinal ligaments of OPLL patients have an osteogenetic predisposition and that TFG-beta may play a role in the ossification.

Animals↗

PubMedDate not supplied

Immunohistochemical localization of bone morphogenetic proteins and the receptors in epiphyseal growth plate.

The expression of bone morphogenetic proteins (BMPs) and BMP receptors (BMPRs) in the epiphyseal growth plate has not been clarified. In this study, we studied immunohistochemically the spatial and temporal localization of BMP-2/4, osteogenic protein-1 (OP-1, or BMP-7), and BMP receptors (BMPR-IA, BMPR-IB, and BMPR-II) in the epiphyseal plate of growing rats. The proximal parts of tibia in growing rats were observed. At 12 weeks after birth, BMP-2/4 and OP-1 were expressed markedly in proliferating and maturing chondrocytes. BMPR-IA, IB and II were clearly co-expressed in proliferating and maturing chondrocytes, and the expression was decreased in hypertrophic chondrocytes. At 24 weeks, the expression of BMP-2/4 and OP-1 was decreased, but BMPRs were still well-expressed in proliferating chondrocytes. The temporal and spatial expression of BMP and BMPR suggests that BMP and BMP receptors play roles in the multistep cascade of enchondral ossification in the epiphyseal growth plate.

Aging↗

PubMedDate not supplied

Intensive preoperative chemotherapy for osteosarcoma in the lower extremity.

BACKGROUND: The aims of this study were to investigate the effect, if any, of preoperative chemotherapy and to investigate the adaptation and the limits for achieving a more functional limb in our limb-salvaging procedure. MATERIALS AND METHODS: Since 1983 to 1997 we have treated 53 cases of osteosarcoma in an upper or lower limb at our Institute. According to surgical staging by Enneking, there were 37 cases at stage II B, and 16 cases at stage III. Neoadjuvant chemotherapy was performed according to one or other of our four protocols. RESULTS: The 5-year-survival rate was 68% for those cases at stage II B, and was 13% for those at stage III. In particular, we adopted the protocol involving hyperthermic isolated regional perfusion (HIRP) for those cases in which the lesion affected the knee joint. CONCLUSION: The various protocols of chemotherapy including HIRP were effective to permit reduction in the surgical margin and were also effective to achieve an increase in the limb-salvaging rate and especially effective for increasing the salvaged limb-functionality.

Adolescent↗