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Biomedical subjects

K Hatakeyama

Publications and source records attributed to K Hatakeyama.

At least 235 records · Page 13Linked to original sources
PubMed1997

Localization and activity of tissue factor in human aortic atherosclerotic lesions.

Tissue factor (TF) is a transmembrane protein that serves as the major initiator of the blood coagulation cascade. The overexpression of TF antigen and mRNA has previously been reported in advanced atherosclerotic lesions. Recently TF procoagulant activity has also been identified in these lesions. However, localization and activity of TF in various stages of atherosclerosis have not yet been reported. We studied TF localization and its activity in three stages of the human atherosclerotic lesions (diffuse intimal thickening, fatty streak, and atheromatous plaque). The thoracic aortas were obtained from 23 autopsy cases and were examined immunohistochemically using an anti-human TF polyclonal antibody and biotinylated factor VIIa (FVIIa) as a probe to test the FVIIa-binding ability of TF. In addition, the TF-mediated activation of factor X (FX) was quantitatively assessed using a chromogenic assay. In lesions of the diffuse intimal thickening and the fatty streak, almost all of intimal smooth muscle cells (SMCs), macrophages, and endothelial cells were positive for TF. In the atheromatous plaques, TF antigen was detected extensively in the extracellular matrix as well as in the intimal cells. TF in all stages of atherosclerotic lesions had the ability to bind biotinylated FVIIa. TF activity was detected in each lesion and was more prominent in fatty streaks and atheromatous plaques than in the diffuse intimal thickening. These results indicate that active TF is expressed in the early stage of atherosclerotic lesions as well as in the advanced stage, and it contributes to the thrombotic property of human atherosclerotic lesions.

Adolescent↗
PubMed1997

Obstructive ileus caused by a swallowed foreign body (a "press-through" package) and preexisting adhesions.

A "press-through" package (PTP), because it is large and square-shaped, tends to be caught in the esophagus when swallowed. A rare case of obstructive ileus induced by a PTP that was swallowed by 54-year-old man with a history of diabetes mellitus and acute appendectomy is reported. The PTP was 19 mm x 18 mm and was lodged in the cecum, which was stenosed because of preexisting intestinal adhesions; consequently, the PTP obstructed the ileus. The PTP was surgically removed.

Constriction, Pathologic↗
PubMed1997

Lymph node recurrence of gallbladder carcinoma successfully managed by systemic chemotherapy with 5-fluorouracil and mitomycin C: report of a 5-year survivor.

Although gallbladder cancer (GBC) is believed to be chemoresistant, the effectiveness of chemotherapy against lymph node metastasis has been reported. We report a 70-year-old woman with advanced GBC in whom isolated, widespread lymph nodal recurrence after a radical resection responded completely to systemic chemotherapy with mitomycin C and 5-fluorouracil. This patient remains symptom-free with no evidence of disease at 6 years after surgery (5 years after the initiation of chemotherapy). Both our case and a literature review suggest that nodal disease appears more chemosensitive than the primary lesion in GBC. Chemotherapy may provide long-term palliation for selected patients with isolated nodal recurrence.

Aged↗
PubMed1997

Serial changes in contribution of substrates to energy expenditure after transthoracic esophagectomy for cancer.

This study was designed to examine the metabolic response of patients following transthoracic esophagectomy for carcinoma of the esophagus during the administration of total parenteral nutrition. Thirty-five patients underwent a right thoracotomy and transthoracic esophagectomy with nodal dissection in the neck, mediastinum, and abdomen. The resting energy expenditure (REE) was measured preoperatively, and on the 1st, 3rd, 5th, and 7th postoperative days (PODs) using indirect calorimetry. The REE was significantly higher following transthoracic esophagectomy on PODs 1, 3, 5, and 7 than preoperatively. The caloric contribution of fat was significantly less on 3rd, 5th, and 7th PODs than on the 1st POD. In contrast, carbohydrate oxidation increased significantly on the 3rd, 5th, and 7th PODs compared to that of the 1st POD. These results may help optimize the nutritional support regimen for post-esophagectomy patients.

Adult↗
PubMed1997

Intraoperative ultrasonography versus cholangiography during laparoscopic cholecystectomy: a prospective comparative study.

BACKGROUND: The purpose of this study was to compare the functional utility of intraoperative ultrasonography (IOUS) and cholangiography (IOC) during a laparoscopic cholecystectomy for the treatment of gallstone disease. STUDY DESIGN: A prospective study comparing IOUS and IOC was carried out in 65 patients. Intraoperative ultrasonography was conducted first using a 7.5-MHz linear array probe. After IOUS, IOC was then conducted in all patients. The respective usefulness of IOUS and IOC in the identification of gallstones, detection of hepatobiliary structures, and demonstration of congenital anomalies was then compared. RESULTS: Intraoperative ultrasonography was successful in all 65 patients, and IOC was successful only in 54. The time required for IOUS was significantly shorter (p < 0.0001) than for IOC. Intraoperative ultrasonography imaged the hepatic ducts and their confluence, the common hepatic duct, the common bile duct, and the ampulla of Vater in 97, 100, 97, and 51% of cases, respectively. Intraoperative cholangiography, on the other hand, depicted these structures in 85, 89, 100, and 94% of cases, respectively. Intraoperative ultrasonography demonstrated the cystic duct and its confluence in 94% of cases. Biliary anomalies were identified by IOUS in 12 patients and by IOC in 13. Intraoperative ultrasonography could detect the hilar vascular structures in most patients and visualized anomalies of the hepatic arteries in 5 patients. In this series, 5 patients had choledocholithiasis. The sensitivities, specificities, positive and negative predictive values, and accuracies in identifying these bile duct stones were 80, 98, 80, 98, and 97% by IOUS, and 80, 97, 67, 98, and 95% by IOC, respectively. CONCLUSIONS: Intraoperative ultrasonography is superior to cholangiography with respect to its safety, shorter examination period, and ease of administration in all patients. In addition, IOUS is also better for identifying subtle anatomic detail. Intraoperative ultrasonography compares favorably with IOC in terms of utility in exploring bile ducts for stones. Intraoperative ultrasonography is an effective procedure for biliary exploration during a laparoscopic cholecystectomy.

Cholangiography↗
PubMed1997

Circadian rhythm of leucocytes and lymphocytes subsets and its possible correlation with the function of the autonomic nervous system.

There are physiological variations in the levels of leucocytes. Among these, the circadian rhythm is very important in terms of the magnitude. Since newly identified lymphocyte subsets (i.e. extrathymic T cells) have recently been detected, a comprehensive study of the circadian rhythm was conducted. All leucocytes were found to vary in number or proportion with a circadian rhythm and were classified into two groups. One group--granulocytes, macrophages, natural killer (NK) cells, extrathymic T cells, gammadelta T cells, and CD8+ subset--showed an increase in the daytime (i.e. daytime rhythm). The other group--T cells, B cells, alphabeta T cells, and CD4+ subset--showed an increase at night. Humans are active and show sympathetic nerve dominance in the daytime. Interestingly, granulocytes and lymphocyte subsets with the daytime rhythm were found to carry a high density of adrenergic receptors. On the other hand, lymphocyte subsets with the night rhythm carried a high proportion of cholinergic receptors. Reflecting this situation, exercise prominently increased the number of cells with the daytime rhythm. These results suggest that the levels of leucocytes may be under the regulation of the autonomic nervous system.

Adult↗
PubMed1997

Self-reactive forbidden clones are confined to pathways of intermediate T-cell receptor cell differentiation even under immunosuppressive conditions.

It is believed that self-reactive forbidden T-cell clones are generated by 'failure' of the pathway of T-cell differentiation in the thymus, if it is disturbed. We examined how such forbidden clones are generated under immunosuppressive conditions. Mice were treated with an injection of deoxyspergualin, FK506, or cycloporin A. From day 3, the number of cells yielded by various organs decreased. Because of the resistance of intermediate (int) T-cell receptor (TCR) cells (i.e. TCRint cells), they became more prominent in proportion than TCRhigh cells. TCRhigh cells are conventional T cells generated through the mainstream in the thymus, whereas TCRint cells are primordial T cells generated by the extrathymic pathway or an alternative intrathymic pathway. Similar to untreated mice, forbidden V beta 3+ and V beta 11+ clones in C3H/He (Mls-1b2a) mice were confined to TCRint cells after treatment; there was no leakage of forbidden clones into TCRhigh cells in the thymus and periphery. In parallel with the increase in the proportion of TCRint cells, the proportion of forbidden clones also increased under immunosuppressive states, especially in the liver. Liver mononuclear cells isolated from treated mice still had the potential to mediate autologous killing. The present results suggest that the generation of self-reactive clones is highly restricted to the pathways of TCRint cell differentiation even under immunosuppressive conditions.

Animals↗
PubMed1997

Autologous killing by a population of intermediate T-cell receptor cells and its NK1.1+ and NK1.1- subsets, using Fas ligand/Fas molecules.

Self-reactive clones, estimated by anti-V beta monoclonal antibodies (mAb) in conjunction with the Mls system, are confined to a population of intermediate (int) T-cell receptor (TCR) (or CD3) cells (i.e. TCRint cells), but are not found among TCRhigh cells. The next questions to be answered are whether autologous killing is confined to TCRint cells and how such killing is mediated. In this study, 51Cr-labelled thymocytes of syngeneic or allogeneic origin were used as target cells (4-hr assay). When liver and splenic mononuclear cells (MNC) obtained from B6 mice were used as effector cells, prominent autologous killing was seen in liver MNC, but not splenic MNC. Such killing was not seen when thymocytes from B6-lpr/lpr mice (i.e. Fas-) were used as target cells, nor when liver MNC from MRL-gld/gld mice (i.e. Fas ligand-) were used as effector cells (target thymocytes of MRL(-)+/+ mice). Cell separation experiments using a cell sorter revealed that autologous killing was mediated for the most part by CD3int cells, while allogeneic killing was mediated entirely by natural killer (NK) cells, TCRint cells and TCRhigh cells. Among CD3int cells, the NK1.1+ subset (i.e. NK1.1+ T cells) manifested a higher level of autologous killing than did the NK1.1- subset. Consistent with the results of a functional assay, it was found by reverse-transcription-polymerase chain reaction (RT-PCR) assay that CD3int cells among liver MNC showed the expression of Fas ligand mRNA, while thymocytes expressed Fas mRNA. When class I major histocompatibility complex (MHC)- thymocytes (from beta 2-microglobulin-deficient mice) were used as target cells, NK cells, but not CD3int cells, showed potent cytotoxicity. These results suggest that autologous killing is a major function of TCRint cells with self-reactivity, and that such killing is mediated by means of Fas ligand/Fas molecules.

Animals↗
PubMed1997

Telomerase activity and metastasis: expansion of cells having higher telomerase activity within culture lines and tumor tissues.

Tumor cells with metastatic potential may have a high telomerase activity that augments telomeric DNA repeats, allowing the cells to escape from the inhibition of cell proliferation due to shortened telomeres. We examined the expression level of telomerase activity using the telomeric repeat amplification protocol among a series of cell lines obtained by repeated transplantation of a mouse fibrosarcoma. The lines could be grouped into three; one has no metastatic potential, and the other two show metastatic abilities after intravenous or subcutaneous injection. Comparison of their telomerase activity indicated that more malignant lines had higher activity. A similar relation was seen in metastatic nodules formed through clonal expansion from the heterogeneous population of inoculated cells; clonality was monitored in terms of variable patterns of subtelomeric repeats. The results suggest that a high level of telomerase activity may not be requisite for metastasis, but may confer a propensity to dominate in a tumor tissue.

Animals↗
PubMed1997

Ictal EEG and single photon emission computed tomography in a patient with cortical dysplasia presenting with atonic seizures.

PURPOSE: Ictal studies of atonic seizures in children with epilepsy are rare. To clarify the neurophysiologic mechanism of such seizures, we describe a cluster of atonic seizures in a 6-year-old girl with cortical dysplasia. METHODS: Ictal activity was recorded as slow-wave bursts beginning over the right frontocentral regions, where the cortical dysplasia was detected by magnetic resonance imaging (MRI), and propagating to the left hemisphere. RESULTS: The polygraphic recording demonstrated that the atonia indicated by the sudden interruption of electromyogram (EMG) discharges corresponded to the bilaterally synchronous spike-and-wave complexes. An ictal single photon emission computed tomography (SPECT) study with 99mTc hexamethyl propylene amine oxime ([99mTc]HMPAO) simultaneously performed during EEG recording showed marked bilateral mesial frontal and right frontoparietal hyperperfusion. CONCLUSIONS: Our findings suggest that the neurophysiological mechanism of the atonic seizures may be produced by a strong inhibition in the bilateral motor cortexes. Ictal SPECT is valuable in demonstrating the pathophysiology of both atonic seizures and secondary bilaterally synchronous spike-and-wave complexes in the EEG.

Cerebral Cortex↗