Higher renal functional reserve in well-functioning renal grafts.
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Adult↗
Biomedical subjects
T Asano
Publications and source records attributed to T Asano.
Oligodendroglioma with cystic component in infant.
In this report, we examine the case of a 6-year-old girl with a mixed oligodendroglioma demonstrating uncommon neuroradiological images. CT and MR showed an intratemporal mass with multilocular cystic formation and intratumoral massive calcification, suggestive either of astrocytoma, dysembryoplastic neuroepithelial tumor, or ganglioglioma as a presumptive differential diagnosis. The tumor was almost completely removed. Post-operative histological examination revealed a mixed oligodendroglioma with a small component of astrocytoma. The combination of radiotherapy and chemical treatment was supplemented.
Antineoplastic Agents↗
Experimental evaluation of the beneficial effect of an antioxidant on cerebral vasospasm.
Based on the previously suggested hypothesis that generation of free radicals leading to lipid peroxidation is involved in the genesis of vasospasm following SAH, the therapeutic effect of an antioxidant on experimental vasospasm was examined. As an antioxidant suitable for this purpose, AVS(1,2-bis(nicotinamide)-propane) was used. Experimental SAH was induced in dogs by intracisternal injection of blood and subsequent changes in the basilar artery diameter was evaluated by angiography. First, intrathecal administration of AVS 3 days after SAH caused prompt resolution of pre-existing chronic vasospasm for 3-4 h. Next, the effect of continuous intravenous administration of saline (control) or AVS was started and continued for 4 days. In the control group, early and chronic spasm was observed on the daily angiography. In the AVS-treated group, early spasm was only moderately inhibited, but the occurrence of chronic spasm was remarkably suppressed in a dose-dependent manner. In these experiments, no adverse effect of AVS on the neurological or systemic conditions was observed. The data indicate that AVS may be beneficial in the treatment of vasospasm following SAH, thereby reinforcing the concept that generation of free radicals is involved in the genesis of vasospasm.
Animals↗
Localization of the histamine H(2) receptor, a target for antiulcer drugs, in gastric parietal cells.
BACKGROUND/AIMS: Histamine H(2) receptor antagonists are widely used for the treatment of peptic ulcer disorders. However, whether the H(2) receptor is present in parietal or immune cells in the lamina propria remains controversial. This study is designed to determine the H(2) receptor localization immunohistochemically using an antibody against the newly cloned mouse histamine H(2) receptor. METHODS: We cloned the mouse histamine H(2) receptor gene and generated a specific antipeptide antibody against the C terminus. Immunohistochemical studies were performed with this antibody and with a monoclonal antibody against H(+)/K(+) adenosine triphosphatase (ATPase). RESULTS: Histamine H(2) receptors were localized on the plasma membrane and on the cytoplasm just beneath the plasma membrane on the basolateral sides of gastric cells. Confocal microscopy of double-stained sections using the monoclonal antibody against H(+)/K(+) ATPase, a specific parietal cell marker, showed that histamine H(2) receptors colocalized with H(+)/K(+) ATPase. No specific histamine H(2) receptor immunoreactivities were observed in the submucosal regions. CONCLUSION: The H(2) receptor is localized in the gastric parietal cell.
Amino Acid Sequence↗
Long-term follow-up results of bilateral thalamotomy for parkinsonism.
27 patients who underwent bilateral thalamotomy for parkinsonism over the past 10 years have been clinically evaluated. Mean follow-up period was 6.2 years after second surgery. In these cases, 8 returned to full social life without any medication, 4 were capable of social life with medical treatment, 6 were self-sufficient and 3 were semi-self-sufficient in ADL, respectively. Therapeutic drug doses were reduced in all cases. L-Dopa-induced dyskinesia was not observed after second surgery. Speech disturbance, which was not severe, was recognized in 12 cases as a complication.
Adult↗
Readiness potentials recorded from the scalp and depth leads.
Readiness potentials on voluntary hand movements were recorded from the scalp (C3, C4), premotor cortex, subcortical white matter and VL nucleus of the thalamus. Subjects were healthy right-handed men and patients with involuntary movement disorders. We obtained a slow negative shift of brain electrical potentials from the scalp and cortex preceding voluntary hand movements. The mean time interval between the onset of the readiness potential and the onset of motor activity (mean T) was 0.8 sec on right hand movements and 1.0 sec on left hand movements in healthy men. In cases with parkinsonism, the mean T value was 1.4 sec in patients with akinesia, 1.1 sec in those without akinesia. The amplitude of readiness potentials was higher in the scalp contralateral to the hand movement. The readiness potentials recorded from the VL nucleus and white matter were reversed in polarity from those of scalp and cortex. Simultaneous recordings from cortex and VL nucleus showed early onset of readiness potentials from the cortex by approximately 0.1 sec compared with the VL nucleus.
Brain Mapping↗
Localization of GTP-binding protein Go in the enteric nervous system in rat ileum.
The localization of a GTP-binding protein G(o) was examined immunohistochemically in rat ileum using antibodies against the alpha-subunit of G(o) (G(o) alpha). G(o) alpha-positive fibers clearly demonstrated the topography and structure of the enteric nervous system of the ileum. G(o) alpha was present only in the nervous system and was generally distributed both in synapse-rich and in nonsynaptic areas. The distribution of G(o) alpha in a nonsynaptic area suggests the possibility that G(o) may be involved not only in neurotransmission mechanisms but also in other functions.
Animals↗
Antitumor effect of murine colon carcinoma cells retrovirally transduced with interleukin-4 and granulocyte macrophage-colony stimulating factor genes.
We have investigated the antitumor effect of murine colon carcinoma cells developed to produce cytokines. Retrovirally transduced cells were inoculated into syngeneic mice, and their survivals were examined. Inoculation of interleukin-4 (IL-4)- or granulocyte macrophage-colony stimulating factor (GM-CSF)-producing cells alone did not affect the survival of the mice. In the tumors derived from an admixture of IL-4 and GM-CSF producers, however, regression developed spontaneously, and prolonged survival of the challenged mice was consequently observed. Histological examination revealed predominant infiltration of neutrophils around the tumor of a mixed population of IL-4 and GM-CSF producers.
Animals↗
Protection from cerebral ischemia by a new imidazole derivative (Y-9179) and pentobarbital. A comparative study in chronic middle cerebral artery occlusion in cats.
For the purpose of investigating the protective action against cerebral ischemia by a new imidazole derivative (Y-9179) and pentobarbital, regional cerebral ischemia was produced in 53 cats by permanent occlusion of the middle cerebral artery (MCA) via the transorbital approach. In 20 cats, the clips were applied at the origin of the right MCA whereas in the remaining 33 they were applied laterally. The administration of Y-9179 (6.25 and 12.5 mg/kg/day), pentobarbital (25 mg/kg/day) and saline was started 30 min after MCA occlusion and continued for 3 days. The cats were observed for 7 days and then sacrificed. Since there was a remarkable difference in mortality between the medial (65%) and the lateral occlusion groups (15%), the evaluation of drug effects was based only on the results obtained with the lateral occlusion group. The brains were sliced at 4 fixed coronal planes, in which the ratios of the infarcted area in the 2 hemispheres were obtained by planimetry. A statistically significant decrease in the infarction rate was found both in Y-9179 and pentobarbital-treated groups compared to the control group. Since the CNS depressant action of Y-9179 is far less potent than that of pentobarbital, the present results indicate the potential usefulness of Y-9179 in the management of strokes.
Animals↗
Correlation between rCBF and histological changes following temporary middle cerebral artery occlusion.
Correlations between changes in regional, cortical, cerebral blood flow (rCBF) and histological changes in the corresponding brain regions were examined following middle cerebral arterial occlusion in 24 cats. In all animals, the duration of arterial occlusion was 2 hours followed by 2 hours of recirculation. The animals were divided into 2 groups according to the severity of the observed histological damage. Severe cortical damage was observed in 8 cats (Group A), and, in the remaining 16 cats, little or no cortical damage was seen (Group B). There was a statistically significant difference between these 2 groups in the average rCBF values during ischemia. During recirculation, there was a prompt and uniform recovery of rCBF in animals in group B but a marked diversity; of rCBF ranging from hyperemia to oligemia in animals in group A. This diversity of rCBF reflects inhomogenous blood flow. This study indicates potential hazards for surgical revascularization in the aute stage of stroke when brain damage has progressed beyond a certain level.
Animals↗
Mechanisms of cerebral protection by pentobarbital and nizofenone correlated with the course of local cerebral blood flow changes.
The effects of delayed administration of pentobarbital and a novel imidazole derivative (Nizofenone or Y-9179) on the infarction size following the regional cerebral ischemia were studied using the permanent middle cerebral artery (MCA) occlusion model in cats. The courses of local cerebral blood flow (lCBF) before and after drug administration were also studied using the hydrogen clearance method. The extent of infarction one week after MCA occlusion was significantly smaller in the drug-treated groups than in the control group. Regarding the time-course of lCBF, there was no significant differences between the control and the Y-9179 groups. On the other hand, pentobarbital administration caused a significant lCBF increase in low-flow areas where the lCBF following MCA occlusion was below 40 ml/100g/min. In spite of this flow increase, the corresponding cortical areas underwent infarction. Histological examination of the state of vasogenic edema revealed that the perivascular exudation of plasma fluid in the infarcted area was definitely less in the Y-9179 treated group than in the other groups. Results indicate that redistribution of lCBF may not be involved in the mechanism of cerebral protection by pentobarbital or Y-9179.
Animals↗
Ischemic brain edema following occlusion of the middle cerebral artery in the rat. I: The time courses of the brain water, sodium and potassium contents and blood-brain barrier permeability to 125I-albumin.
The present study was undertaken to analyze the roles of brain cations and of the blood-brain barrier (BBB) to albumin in the development of ischemic brain edema. Using the rat middle cerebral artery (MCA) occlusion model, changes in the brain water, sodium, and potassium contents were followed for a period of seven days. The permeability of the BBB to proteins was also followed by 125I-albumin transfer from the blood into the brain. A significant edema developed as early as three hours after MCA occlusion. This progressed rapidly to reach a maximum on the third day, gradually regressing thereafter. The increase in the brain water contents showed a parallel time course to the increase in the sodium and decrease in the potassium contents. A significant increase in the BBB permeability to albumin occurred 72 hours after MCA occlusion. However, there was no correlation between the brain water content and BBB permeability to albumin in the hemispheres studied 72 hours after MCA occlusion. The correlation between the brain water and sodium contents was not clear during the first six hours, but became highly significant thereafter. The data suggest that an increase in the BBB permeability to sodium occurred 12-48 hours after MCA occlusion, which, together with an antecedent intracellular shift of sodium, resulted in a massive influx of water and sodium into the brain. The BBB permeability change to sodium, not to proteins, seems to play a predominant role in the pathogenesis underlying ischemic brain edema.
Animals↗
Ischemic brain edema following occlusion of the middle cerebral artery in the rat. II: Alteration of the eicosanoid synthesis profile of brain microvessels.
Using the rat middle cerebral artery occlusion model, alterations in the eicosanoid synthetic capacity of brain microvessels following ischemia were studied by radiochromatography. Brain microvessels of normal rats predominantly produced hydroxyacids with relatively small amounts of PGD2 and PGE2 from exogenous arachidonic acid. Confirmation that hydroxyacids and prostaglandins were products respectively of lipoxygenase(s) and cyclooxygenase was obtained by experiments using indomethacin and eicosatetraynoic acid. The eicosanoid synthetic capacity of the brain microvessel, especially of hydroxyacids, was significantly enhanced 24 and 72 hours after the onset of ischemia. Because this is the phase of maximum edema in the present model, enhanced eicosanoid production in the brain microvessel may be involved in the mechanisms that underly ischemic brain edema.
Animals↗
Identification and quantitative analysis of hydroxy-eicosatetraenoic acids in rat brains exposed to regional ischemia.
To clarify possible roles in the pathogenesis of ischemic brain edema, identification and quantitative analysis of hydroxy-eicosatetraenoic acids (HETEs) in rat brains exposed to middle cerebral artery occlusion were carried out using high-performance liquid chromatography. Rat brain sampling was done by in situ freezing 24 and 72 hours after occlusion. Only a small amount of 15-HETE was found in control rat brains. Twenty-four hours after ischemia, 11-HETE appeared, and the amount of 15-HETE tended to increase. Seventy-two hours after ischemia, when brain edema reached its maximum, 5-, 8-, 9-, 11-, 12-, and 15-HETEs were identified, and the amounts of all HETEs except 8- and 12-HETE were significantly increased. The detection of 5-HETE in ischemic rat brain indicates the simultaneous production of leukotrienes in the same brain area. The above results support the view that lipoxygenase products may play significant roles in the formation of ischemic brain edema.
Animals↗
Combined therapy with radiofrequency thermal ablation and intra-arterial infusion chemotherapy for hepatic metastases from colorectal cancer.
BACKGROUND/AIMS: In this preliminary study, we investigated the efficacy of combined radiofrequency thermal ablation therapy (RFA) with hepatic arterial infusion chemotherapy (HAI) in the treatment of multiple liver metastases from colorectal cancer. METHODOLOGY: Nine patients with bilobular multiple metastases was treated. The number of nodules was 6.0 +/- 3.9 (range: 2-13), and the size was 2.1 +/- 1.0 cm (range: 0.5-4.8 cm) in diameter. RFA was performed using a RF generator operating at 460 kHz with a 15-gauge, 4-prong custom RF needle. Treatment temperature was kept at 90-110 degrees C for 5 min. 5-Fluorouracil (5-FU) was administered by weekly 750-1250 mg/body/5 h as the regimen of HAI. RESULTS: During a 15.2-month follow-up period, 6 of 9 patients survived more than 1 year. Three of the 6 survived more than 2 years. Serum CEA level in 5 patients dropped from 24.5 +/- 9.5 ng/ml to 10.3 +/- 5.5 ng/ml. Local recurrence was observed in 5 patients and new lesions in 4. Extrahepatic recurrence was observed in 5 patients. There were no serious complications but one HAI-related cerebral thrombosis. CONCLUSIONS: Combined RFA with HAI would be effective and safe. This modality provides a new option for the treatment of multiple liver metastases from colorectal cancer.
Adult↗
Application of high energy shock waves to cancer treatment in combination with cisplatin and ATX-70.
BACKGROUND: The anti-tumor effects of high-energy shock waves (HESW) in combination with cisplatin (CDDP) and ATX-70, as a photosensitizer, were investigated in vitro and in vivo. METHODS: Active oxygen generation by HESW was studied by means of electron spin resonance (ESR) system. The anti-tumor effects of HESW in combination with cisplatin (CDDP) and ATX-70 was investigated in vitro and in vivo. RESULTS: HESW exposure induced singlet oxygen or hydroxyl radical. Adding ATX-70 enhanced the cell damage induced by HESW dose-dependently. Ascorbic acid inhibited the combined effect of HESW and ATX-70. Adding CDDP did not enhanced cell damage by HESW. The combined therapy of HESW, CDDP and ATX-70 showed further inhibition of tumor growth in vivo. CONCLUSIONS: These results indicate that HESW activated ATX-70, and that the anti-tumor effect of HESW and ATX-70 was caused by active oxygen generation. HESW is able to be utilized with any other cancer treatment.
Animals↗
Differential efficacy of suicide gene therapy by herpes simplex virus-thymidine kinase gene reflects the status of p53 gene in human esophageal cancer cells.
We examined the effect of herpes simplex virus-thymidine kinase gene (HSV-TK)-mediated suicide gene therapy on human esophageal cancer. Two human lines, T.Tn cells which bears truncated p53 and TE2 cells with wild-type p53, were transduced with the HSV-TK gene and tested for their sensitivities to a prodrug, ganciclovir (GCV). The transduced cells, T.Tn/TK and TE2/TK, increased in vitro sensitivity to GCV compared with that of respective wild-type cells. However, the growth suppression of T.Tn/TK tumors induced by GCV was marginal in nude mice and the tumors regrew thereafter. In contrast, the growth of TE2/TK tumors was significantly inhibited by GCV and all the tumors disappeared. The status of the p53 gene of tumor cells thereby may influence the efficacy of the HSV-TK/GCV system.
Animals↗
p53 protein expression in intraductal papillary mucinous tumors (IPMT) of the pancreas as an indicator of tumor malignancy.
BACKGROUND/AIMS: Intraductal papillary mucinous tumors, as a cystic disease in the pancreas, clinically has a more indolent and favorable course than invasive ductal pancreas carcinoma. However, some cases of intraductal papillary mucinous tumors show invasive and rapid progression like ductal pancreas carcinoma and the prognosis of such patients is sometimes poor. In the current study, we carried out immunohistochemical staining of intraductal papillary mucinous tumor tissues for p53 and investigated whether positive staining indicates tumor malignancies and has a prognostic value for intraductal papillary mucinous tumors. METHODOLOGY: Nineteen (19) patients who underwent pancreatic resection under the diagnosis of intraductal papillary mucinous tumors at the Chiba University Hospital between April 1992 and December 1996 were studied. We performed immunohistochemical staining of p53 as well as of PCNA, Ki-67 and Bcl-2 using their respective antibodies. Pathological findings revealed that 9 cases were intraductal papillary adenoma, 9 were intraductal papillary adenocarcinoma, and one was invasive ductal papillary adenocarcinoma. RESULTS: p53 expression could only be detected in the 1 case with invasive ductal papillary adenocarcinoma. Significant association could not be found between histological features and immunohistochemical staining of PCNA, Ki-67 and Bcl-2. CONCLUSIONS: p53 protein expression could be detected after progression to invasive type of intraductal papillary mucinous tumors. The present results demonstrate that p53 expression might be an indicator of invasive progression in intraductal papillary mucinous tumors, and might represent a surgical indicator of intraductal papillary mucinous tumors.
Adenocarcinoma, Papillary↗