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H Abe

Publications and source records attributed to H Abe.

At least 685 records · Page 38Linked to original sources
PubMed1994

Distribution of mRNA for CCK-B receptor in the brain of Mastomys natalensis: abundant expression in telencephalic neurons.

The distribution of cholecystokinin B (CCK-B) receptors in the Mastomys brain was studied using Northern blot analysis and in situ hybridization technique. By Northern blot analysis using 32P-labeled cDNA probe, the cortex had the highest hybridization signal of CCK-B receptor mRNA in the brain. The olfactory bulb and hippocampus showed a moderate level of signals. In situ hybridization using 35S-labeled cRNA probes revealed a wide and region-specific distribution of CCK-B receptor mRNA in the telencephalon. Throughout the cerebral cortex, labeled cells were found in all layers, with higher intensities in layers II, V and VI. Pyramidal cells of the layer II of the piriform cortex showed the highest level of signals in the brain. In the hippocampus, most of the pyramidal cells of the Ammon's horn were labeled, although labeled cells were not detected in other layers. Distinct signals were also detected in the various amygdaloid nuclei, caudate-putamen, reticular thalamic nucleus, hypothalamic ventromedial nucleus and inferior colliculus. This distribution pattern may further support the prominent existence of CCK-B receptors in the brain particularly in the telencephalon.

Animals↗
PubMed1994

Effect of type-1 plasminogen activator inhibitor on human leukocyte elastase.

When human leukocyte elastase (HLE) activity (1.0 microgram/ml) was analysed in the presence of PAI-1 (0.15.0 micrograms/ml), HLE activity, measured with the low molecular weight paranitroanilide substrate L-pyroglutamyl-prolyl-L-valine-p-nitroanilide was increased time and dose dependently (a plateau of stimulation was reached after 30 minutes) with a simultaneous decrease in PAI-1 inhibitory activity. This effect was neither influenced by the presence of vitronectin nor heparin. When PAI-1 was converted into its latent form by incubation for 48 hours at 37 degrees C or incubated with an excess of recombinant t-PA to convert free PAI-1 into t-PA-PAI-1 complexes, the stimulatory effect of both the latent and the complexed form of PAI-1 was significantly greater than that of the active form. Analysing HLE PAI-1 interaction on a molecular level using SDS-PAGE, no SDS stable complex formation between HLE and PAI-1 could be observed but lower molecular weight cleavage products of PAI-1 were generated. The stimulatory effect of PAI-1 on HLE activity was not restricted to the low molecular weight pNA-substrate but was also revealed using a natural substrate assay (bovine neck ligament elastin solubilization). Therefore interaction of HLE and PAI-1 seems not to be restricted just to decrease PAI-1 activity but would simultaneously also increase HLE activity, thereby supporting enzymatic activity necessary for migration of leukocytes, dissolution of blood clots and tissue remodelling.

Glycoproteins↗
PubMed1994

Disruption of neuronal migration in the neocortex of the dreher mutant mouse.

To analyze developmental abnormalities related to neuronal migration in the dreher mutant mouse, the neocortical cytoarchitecture of dreher and control mice were examined in Nissl-stained serial sections by light microscopy. In general, the dreher neocortex has six layers which are similar in size and thickness to those observed in normal mouse neocortex. However, in dreher neocortex, three types of abnormalities were found: (1) an increase in the number of diffusely distributed neurons in layer I, (2) small, ectopic collections of neurons in layer I, and (3) isolated disturbances of local cytoarchitecture characterized by neuron-free space distributed in areas between layer II to IV. The occurrence of small, punctate deficits in the dreher neocortex may be secondary to disruptions of the radial glial fiber system and neuronal migration. The fact that cytoarchitectonic abnormalities of several types were found in the dreher neocortex may be useful in analyzing the relationship between radial glial fibers and migrating young neurons, the synaptic connections which are formed by ectopically situated neurons, and the mechanism of formation of sporadically distributed neocortical abnormalities.

Animals↗
PubMed1994

Regional variations in the ultrastructural features of secretory cells in the rat oviductal epithelium.

BACKGROUND: In mammals, the oviductal secretory cells and their secretions play important roles in reproductive and developmental events. Therefore, many electron microscopic studies of mammalian oviductal epithelial cells have been performed. METHODS: The secretory cells in various regions of the rat oviduct during the estrous cycle were examined by transmission electron microscopy. RESULTS: In the fimbriae, the secretory cells contained small secretory granules with moderately electron-dense matrices and many large bodies that resembled lipid droplets. In the ampullar cells, small secretory granules with moderately electron-dense matrices were observed in the apical cytoplasm. In the isthmus, the secretory cells contained numerous secretory granules with moderately electron-dense matrices. Electron-dense areas were frequently observed in many of the granules of the isthmic cells. Vesicles, partially filled with a dense substance, frequently were observed in the isthmic cells and occasionally in the ampullar cells. Very long stereocilia projected from the surfaces of the isthmic secretory cells into the lumen. Exocytosis of the secretory granules was observed. In addition, there was evidence to suggest the release of the bodies that resembled lipid droplet occurred. Cysts and ciliated vacuoles that appeared to be intraepithelial were frequently observed in the fimbrial and ampullar epithelia. No dramatic changes in the relative numbers of ciliated and secretory cells in any oviductal segment were observed during the estrous cycle. CONCLUSIONS: Our ultrastructural observations of the rat oviduct revealed marked regional variations in the morphological features of secretory cells. These results may provide insight into regional and cellular differences in the function of the rat oviduct.

Animals↗
PubMed1994

Analysis on heterogeneity of squamous cell carcinoma antigen by two-dimensional electrophoresis.

Squamous cell carcinoma (SCC) antigen was separated by two-dimensional electrophoresis combined with immunoblotting into four spots: spot 1 with pI 6.4 and 44.5 kDa, spot 2 with pI 6.3 and 44.5 kDa, spot 3 with pI 6.0 and 44.5 kDa, and spot 4 with pI 5.9 and 45 kDa. In cancer and noncancerous tissues, it was common that spot 1 was the largest spot. In noncancerous tissues, spot 3 was the smallest spot and spot 2 was stained as densely as spot 4. In cancer tissues, however, spot 4 was apparently smaller than spot 2 and 3. Also, spots 2 and 3 in cancer tissues were larger than those in noncancerous tissues. When SCC antigen was treated with alkaline phosphatase prior to isoelectric focusing (IEF), spot 4 disappeared from the immunoblotting pattern. When the SCC antigen was treated with alkaline phosphatase after IEF, spot 4 changed its molecular weight to the same weight as that of the other three spots. These results strongly suggest that spot 4 is phosphorylated SCC antigen.

Antigens, Neoplasm↗
PubMed1994

Localized proton spectroscopy of focal brain pathology in humans: significant effects of edema on spin-spin relaxation time.

Localized proton nuclear magnetic resonance (NMR) spectroscopy of human brain in two common focal pathologies producing brain edema (peritumor edema and acute edematous ischemic stroke) was performed utilizing point resolved spectroscopy (PRESS). The spectra obtained from the pathological tissues were characterized by a reduced N-acetyl-aspartate (NAA) to total creatine (Cr) ratio (NAA/Cr) and high level of lactate. While the spin lattice relaxation time (T1) of the main metabolite resonances, namely, those of NAA, Cr, and choline containing compounds (Cho), showed values similar to those of normal brain, the spin-spin relaxation time (T2) of these metabolites exhibited a dramatic shortening in pathological tissues. Serial postoperative measurements of T2 in two patients with peritumor edema showed a gradual recovery of the T2 shortening corresponding to improvement of the edema. The majority of localized spectroscopy studies in humans is performed using a sequence which utilizes spin echo signals with a fixed single echo time. Hence, the signal intensities of the metabolite resonances obtained are inherently T2 dependent. The current study underscores that cautious interpretation of clinical data with respect to metabolite quantification is warranted.

Adult↗
PubMed1994

A high-field magnetic resonance imaging study of experimental vasogenic brain edema and its response to AVS: 1,2-bis (nicotinamido)-propane.

We clearly represented brain structures of rats and permitted a rapid assessment of water gradient of the brain edema by cortical freezing utilizing a high-field (7T) proton magnetic resonance imaging (MRI). The typical time course of vasogenic edema and the efficacy of AVS; 1,2-bis (nicotinamide)-propane upon the edema were presented. Twelve rats with edema induced by cortical freezing were divided into two groups; one group of animals received 0.5 ml of physiological saline with 100 mg (/kg) AVS every eight hours intraperitoneally. The other group of untreated animals received only saline. One three, six, 12, and 24 hours after lesion production, the profiles of edema fluid spreading and the maximum signal intensity (MI) of some regions of interest (ROI) were assessed by T2 weighted images (TE = 70 ms, TR = 3500 ms). One hour after lesion production in the untreated group, a low heterogeneous intensity area was seen mainly in the primarily injured cortex. Two hours later, the margin of the lesion gradually increased in intensity and MI of ROIs around the lesion also gradually increased. Twenty-four h after lesion production edema extended contralaterally via corpus callosum. AVS reduced edema fluid spreading beginning from about six hours after lesion production. The MIs of the AVS treated group were significantly lower than in the untreated group (p < 0.01). We conclude that sequential observation of edema using MRI is a quite practical technique for evaluation of the efficacy of any therapeutic agent.

Animals↗
PubMed1994

Effects of glycyrrhetinic acid on aminonucleoside nephrosis in rats.

The effects of glycyrrhetinic acid (GA), an aglycon of glycyrrhizin extracted from the roots of Glycyrrhizae radix, on puromycin aminonucleoside (PA) nephrosis were studied in rats. Urine protein excretion in female rats (130 g-150 g) receiving PA (50 mg/kg) alone was significantly elevated on the 2nd day after injection of PA and reached a peak on the 14th day. Urinary protein on the 14th day was reduced to 74% in animals treated with GA (20 mg/kg) starting on the 2nd day after injection of PA. The increase in serum cholesterol and the decrease in serum protein were also suppressed by GA. Observation by electron microscopy revealed that the degree of abnormality in glomerular epithelial cells, i.e. loss or fusion of foot processes, was lower in the rats treated with GA after PA injection than in the rat treated with PA alone. Moreover, pretreatment with GA did not suppress urinary protein excretion but when it was given at the same time as PA and after PA a significant decrease in urinary protein excretion was observed.

Animals↗
PubMed1994

Investigation of DNA synthesis in experimentally induced Long-Evans rat myeloschisis by the BrdU/antiBrdU technique.

The volume and DNA synthesis of the neuroepithelium in induced myeloschisis in Long-Evans rats as shown by hematoxylin-eosin and BrdU/antiBrdU immunohistochemical staining patterns were examined at different stages of embryonal development. On day 14 of gestation, control animals contained BrdU-incorporating cells mainly at the alar plate of the closed neural tube. On the same day, the everted neural plate of rats with myeloschisis showed active, diffuse uptake of BrdU in the cells of the matrix layer, although an increase in the volume of the everted neural plate was not yet identifiable. On day 21 of gestation, rats with myeloschisis showed a marked increase in the volume of the neuroepithelium compared with controls. Our investigations suggest that, in myeloschisis, more neuroepithelial cells than normal retain their capability for DNA synthesis on day 14 of gestation, and the overgrowth of the neuroepithelium found on day 21 is possibly a secondary effect of failure of neural tube closure.

Animals↗
PubMed1994

Importance of anti-siphon devices in the treatment of pediatric hydrocephalus.

The effects of an anti-siphon device (ASD) on shunt flow and intracranial pressure (ICP) in 16 children with hypertensive hydrocephalus were examined using quantitative radionuclide shuntography (99mTc) with the children in supine and sitting positions. The average age of these patients was 9.5 years. Results were compared with those recorded in 36 patients with adult normal-pressure hydrocephalus (NPH). The closing pressure levels of shunt valve used were low in 8 cases, medium in 7 and high in 1. Half the children (8) had shunt systems with, and the other 8 without, ASD. In the children who had the shunt system without ASD, sitting shunt flow was significantly greater than supine shunt flow, which indicated overdrainage. Conversely, in children who had the shunt system with ASD, supine shunt flow was greater than sitting shunt flow. Because ASD prevented overdrainage, ICP was higher with the shunt system with ASD than with the shunt system without ASD. Without ASD, sitting shunt flow of children was lower than that of adult patients with NPH because of the lower hydrostatic pressure, which correlated with their height. Conversely, in the presence of a shunt system with ASD, sitting shunt flow of children was greater than that of adults, because of the higher ICP and lower hydrostatic pressure. The effect of ASD was smaller in children than in adults, because positive pressure over the ASD was greater (hypertension vs normal pressure) and negative pressure under the ASD was less (short vs tall) in children than in adults. Thus, in children the ASD was effective in preventing overdrainage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Familial occurrence of moyamoya disease. Magnetic resonance angiography as a screening test for high-risk subjects.

The authors report four cases of familial occurrence of moyamoya disease. Although the pathogenesis of moyamoya disease is not clear, there is extensive evidence that this disease has a tendency to show multifactorial inheritance. Therefore, a screening test for those at high risk, i.e., who have a moyamoya patient among their blood relatives, is clinically important. Magnetic resonance angiography (MRA) successfully revealed abnormal findings specific to moyamoya disease in members of the four probands families. MRA is a powerful and noninvasive way of detecting individuals at high risk of developing moyamoya disease.

Anastomosis, Surgical↗
PubMed1994

Cerebral metabolic changes in delayed carbon monoxide sequelae studied by proton MR spectroscopy.

The pathogenesis of delayed sequelae of carbon monoxide (CO) exposure is still unknown. We repeatedly examined a 55-year-old woman with the interval form of CO poisoning, using proton magnetic resonance spectroscopy (MRS). When the clinical picture was severe, MRS revealed markedly lowered N-acetyl-aspartate (NAA)/creatine and phosphocreatine (Cr) ratio and slightly increased choline containing compounds (Cho)/Cr ratio. Subsequently, NAA and Cho/Cr ratio tended to return to normal, reflecting clinical improvement. Proton MRS shows the previously unrecognised neuronal activity in CO poisoning and precisely reflects the severity of symptoms. We stress the superiority of proton MRS over the conventional radiological examinations in CO poisoning.

Brain↗
PubMed1994

Increased pulsatile movement of the hindbrain in syringomyelia associated with the Chiari malformation: cine-MRI with presaturation bolus tracking.

Cine-MRI with presaturation bolus tracking was used in patients with syringomyelia associated with a Chiari malformation to study pulsatile movement of the hindbrain, cervical spinal cord, cerebrospinal fluid and the fluid within the syrinx. Nine patients had 13 examinations, 6 preoperative, 3 after syringosubarachnoid shunting and 4 after posterior fossa decompression. Five controls were also examined. Dynamic display of the acquired images demonstrated downward displacement of the presaturation bolus on the cerebellar tonsils and medulla oblongata (or upper cervical cord) at the C1 level in all preoperative examinations and in two patients after syringosubarachnoid shunting but with residual foramen magnum obstruction. Downward displacement of the bolus on the cervical spinal cord was also demonstrated in 7 examinations, but not observed in the controls. Thus, the hind-brain-spinal cord axis showed larger pulsatile movements in patients with foramen magnum obstruction. Based on these observations and a review of the literature, a new theory on the mode of extension of syringomyelia, emphasising the role of increased pulsatile movement of the hind-brain-spinal cord axis is proposed: that the pulsatile movements, together with a one-way valve mechanism in the syrinx cavity act as a "vacuum-pump" to enlarge the syrinx.

Adolescent↗
PubMed1994

Primary central nervous system lymphoma in Japan--a retrospective, co-operative study by CNS-Lymphoma Study Group in Japan.

This manuscript reports the results of the first cooperative study on primary central nervous system lymphoma (PCNSL) in Japan. Of 196 patients registered, 170 were judged as having PCNSL. No patients were immunocompromised. Of the 170 patients with PCNSL, 93 were males and 77 were females. The mean was 56.7 years. One hundred and nineteen tumors were confirmed histopathologically, and 51 were diagnosed by neuroimaging alone. All the tumors were non-Hodgkin's lymphoma. According to the Working Formulation for Clinical Usage (WF), 96 out of 119 tumors were classifiable: 53 were diffuse large cell type (55.2%), 17 immunoblastic type (17.7%), 9 diffuse small cleaved type (9.4%), 6 diffuse mixed type (6.3%), 5 polymorphous type (5.2%), 5 small lymphocytic type (5.2%) and 1 small non-cleaved type (1.0%). Of 21 tumors studied immunohistochemically, 18 were B-cell type and 3 were T-cell type. Irradiated patients (144) survived significantly longer than non-irradiated patients, (median survival time, MST: 19.2 and 2.7 months, respectively; p < 0.001). There was a remarkable difference in survival among patients of the intermediate lymphomas; MST (18 months) of patients with large cell lymphoma was significantly shorter than MST (over 96 months) of patients with other intermediate grade lymphomas (small cleaved and mixed) (p < 0.001) and had no significant difference from MST (9 months) of patients with high grade lymphomas. If patients were irradiated with more than 40 Gy, higher doses and different modes of irradiation brought no further survival advantage. Chemotherapy was performed in 87 of 144 irradiated patients (60.4%). No regimens were effective in prolonging survival. Of 144 irradiated patients, a complete or partial response to initial treatment was demonstrated in 91 (63.2%) and 43 patients (29.9%), respectively. Improvement in performance status was confirmed in 82 patients (57.0%). Despite a good response to initial treatments, 88 out of 144 evaluatble patients have died of PCNSL (MST: 19 months). Multivariate analysis based on the Cox hazard model revealed that histology of tumor, age at onset, performance status, and radiotherapy were prognostic factors. Neither chemotherapy nor mode of surgery was a beneficial factor.

Adolescent↗
PubMed1994

Magnetic resonance angiography (MRA) of ruptured cerebral aneurysm.

The purpose of this study was to evaluate the high resolution magnetic resonance angiography (MRA) as pre-operative angiography for the detection of ruptured cerebral aneurysms. MRA was performed on 1.5 tesla system using the 3-dimensional time of flight (3D-TOF) method. The field of view was 16 cm or 20 cm and matrix size was 192 x 256 or 256 x 512. Twenty patients with ruptured cerebral aneurysms and 35 cases of non-ruptured aneurysms (incidental aneurysm) examined by both conventional angiography and MRA were included in this study. All the ruptured aneurysms were operated on based on the information obtained from conventional angiography and MRA. Aneurysms smaller than 3 mm in size were difficult to visualize on MRA. However, most ruptured aneurysms were clearly visualized because they were generally larger than 3 mm. The image quality of MRA was satisfactory for planning surgery. Screening for non-ruptured cerebral aneurysms using MRA is controversial. However, in ruptured aneurysms larger than 3 mm in size, MRA clearly revealed the aneurysm, and MRA findings were informative enough to plan surgery. It is concluded that this noninvasive examination can be selected as a first-choice examination especially in cases of ruptured aneurysm.

Aortic Dissection↗
PubMed1994

Cerebral haemodynamic changes after endovascular treatment of arteriovenous malformations: evaluation by single-photon emission CT.

Cerebral haemodynamic changes in 17 patients with cerebral arteriovenous malformations (AVMs), who showed hypoperfusion on single-photon emission computed tomography (SPECT) before endovascular treatment, were studied after embolization. Nine of them had non-haemorrhagic clinical manifestations and the other eight had a history of intracranial haemorrhage. Obliteration of AVMs was nearly total in six patients and partial in eleven. New low density lesions on X-ray computed tomography (CT) developed in 3 of 6 patients after nearly total obliteration and one of 11 patients after partial obliteration. The first SPECT after embolization showed diminished hypoperfusion in 11 of 13 patients without new low density lesions and one of 4 patients with new low density lesions. Diminution of hypoperfusion was seen even in two patients who underwent SPECT study immediately after the embolization. Cerebral circulation was improved in five of eight patients with low density lesions before embolization and in nine of eleven patients after partial obliteration. Hypoperfused state in the haemorrhagic group tended to remain unchanged compared with that in the non-haemorrhagic group. The hypoperfused area was expanded after embolization in three patients with new cerebral infarction. It is important for improvement of cerebral circulation to reduce the shunt flow without causing new infarction due to the embolization itself. In one of two patients who had a hyperperfused area surrounding the AVM after embolization, an unexpected and abnormal degree of brain swelling and haemorrhage occurred at the end of the surgery 20 days after the embolization. In the other patient, total extirpation was successfully performed after confirming disappearance of hyperperfusion in the follow-up SPECT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Long-term observations on morphological changes of choledochal epithelium after choledochoenterostomy in rats.

Morphological changes of the common bile duct were observed macroscopically and microscopically 20 months after choledochojejunostomy and choledochocolonostomy in rats. The common bile ducts were remarkably dilated in all rats of both experimental models. Choledochal stones consisting of fatty acid calcium and calcium bilirubinate were seen in two of six rats with choledochojejunostomy and two of five rats with choledochocolonostomy. The main pathological change observed in both the groups was remarkable hyperplasia of the choledochal epithelium. Only one rat with choledochojejunostomy revealed normal epithelium with choledochal stone formation. Intestinal metaplasia was seen in two rats with choledochojejunostomy and all with choledochocolonostomy. Squamous pseudostratification of the epithelium indicating atypism was observed in two rats with choledochojejunostomy. Sialomucin producing cells and sulfomucin producing cells were seen in the hyperplastic portion of the epithelium. No malignant alteration of the epithelium was detected. These findings indicate that long-lasting exposure to digestive enzymes and bacteria causes epithelial hyperplasia and further exposure to digestive enzymes plays a major role in appearance of the epithelial atypism. Carcinogenesis of the choledochal epithelium under such an environment will need much more time to be established.

Animals↗