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Biomedical subjects

H Abe

Publications and source records attributed to H Abe.

At least 847 records · Page 47Linked to original sources
PubMed1993

[Analysis of cerebral blood flow dynamics and evaluation of extracranial-intracranial arterial bypass function using magnetic resonance angiography with presaturation pulse sequence].

Magnetic resonance (MR) angiography was applied to the study of blood flow dynamics and evaluation of extracranial-intracranial arterial bypass function in patients who had received bypass surgery. Three-dimensional gradient-echo acquisitions with selective presaturation of individual vessels were used to determine the direction of blood flow. Presaturation causes signal loss within the territory supplied by the presaturated artery, without affecting vessels not coursing through the presaturation slab. The patency of arterial bypass graft could be demonstrated as properly with MR angiography as with conventional angiography. In addition to that, MR angiography with presaturation pulse clearly demonstrated the direction of blood flow and the territory supplied by arterial bypass graft. The results were correlated with those from transcranial Doppler sonography and conventional angiography. We concluded that MR angiography is a noninvasive useful method for the evaluation of dependency on post-surgical collaterals and bypass function.

Aged↗
PubMed1993

[A successful surgical treatment of traumatic dissecting aneurysm].

Dissecting thoracic aortic aneurysm caused by blunt trauma was reported. A 64-year-old woman involved in automobile accident was transported to our hospital. Chest X-ray showed multiple rib fractures and enlargement of mediastinal shadow. Emergent CT scan and angiography (DSA) revealed aortic dissection (DeBakey IIIb). She suffered from acute renal and respiratory failure soon after admission, but underwent operation 6 months after the trauma because of enlargement of false channel. Graft replacement was performed and postoperative course was uneventful. Histopathologic findings showed dissection of adventitia of the aorta.

Aortic Dissection↗
PubMed1993

Regio- and stereoselective propranolol metabolism by 15 forms of purified cytochromes P-450 from rat liver.

Regio- and stereoselectivity of cytochrome P-450-mediated propranolol metabolism (4-, 5- and 7-hydroxylations and N-desisopropylation) was studied using 15 purified cytochrome P-450 species. With each purified cytochrome P-450 species, the regioselectivity was distinct and different between the two optical isomers used as substrates. The stereoselectivity was different depending on the position of propranolol to be metabolized. The regio- and stereoselectivity was altered when substrate concentration was altered, suggesting that the kinetics of the reactions are different depending on the positions of propranolol to be metabolized. Furthermore, the selectivity and its manner of alterations with substrate concentrations were different among all cytochrome P-450 species used. Propranolol, with its multiple metabolic pathways and optical isomers, is an extremely interesting substrate for characterization of cytochrome P-450 species.

Amino Acid Sequence↗
PubMed1993

Purification from liver microsomes from untreated cynomolgus monkeys of cytochrome P450 closely related to human cytochrome P450 2B6.

A cytochrome P450 (P450) (referred to as P450CMLa) was purified and characterized from hepatic microsomes from untreated cynomolgus monkeys (Macaca irus). The final preparation was electrophoretically homogeneous and its estimated minimum molecular mass was 49.5 kDa. The amino-terminal amino acid sequence of the protein (first 34 residues) closely resembled that of the protein encoded by the 2B6 cDNA from humans (94%). This protein was cross-reactive with antibodies raised against P450 2B1 (P450 b), P450 2B11 (P450 PBD-2), and P450GP-1, which were purified from hepatic microsomes from phenobarbital-pretreated rats, beagle dogs, and guinea pigs, respectively. Also, the antibody raised against P450CMLa was able to cross-react with P450 2B1, P450 2B11, and P450GP-1. P450CMLa was capable of catalyzing benzphetamine N-demethylation and testosterone 16 beta-hydroxylation in a reconstituted system. Anti-P450CMLa antibody inhibited the activity of testosterone 16 beta-hydroxylase but not the activities of testosterone 2 beta- and 6 beta-hydroxylases in liver microsomes from cynomolgus monkeys. The content of P450CMLa, as estimated by immunoblot analysis, was 70 pmol/mg (about 5% of total P450). The protein immunoreactive with the anti-P450CMLa antibody was also present in liver microsomes from Japanese monkeys, baboons, common marmosets, and common squirrel monkeys. In liver microsomes from common squirrel monkeys, the content of protein immunoreactive with the anti-P450CMLa antibody and the activity of testosterone 16 beta-hydroxylase were effectively increased by pretreatment with phenobarbital. The antibody against P450CMLa strongly inhibited the activity of testosterone 16 beta-hydroxylase in liver microsomes not only from untreated cynomolgus monkeys but also from phenobarbital- and pregnenolone 16 alpha-carbonitrile-pretreated common squirrel monkeys. These results indicated that the P450CMLa purified here is very similar to the forms of P450 classified into the 2B subfamily, in its amino-terminal amino acid sequence, catalytic activities, and immunochemical properties.

Amino Acid Sequence↗
PubMed1993

[Syringomyelia secondary to adhesive arachnoiditis: clinical profiles and efficacy of shunt operations].

The authors report nine cases of syringomyelia secondary to adhesive arachnoiditis treated in our institute from 1982 to 1991. Neurological signs, radiological features, and results of surgical treatment were reviewed. Common initial manifestations in association with syringomyelia were spastic paraparesis in 8 patients (88.9%), regional sensory loss in 4 (44.4%), neurogenic bladder in 4 (44.4%), and somatic pain in 2 (22.2%). All the neurological symptoms or signs progressed gradually for years. All the patients were treated with various modes of shunt operations, including syringo-peritoneal shunt in seven patients, syringo-subarachnoid shunt in one, and ventriculo-peritoneal shunt in one, respectively. Three patients who failed to resolve their major complaints after the first surgery further received syringo-peritoneal shunts. Postsurgical follow-up periods ranged from 18 months to 10 years. Serial MR imaging revealed a significant reduction of the size of syringomyelia in 8 of 9 patients. However only 6 patients showed certain improvement of neurological deficits. Three patients who failed to improve clearly had a long (beyond 15 years) history of syringomyelia before the first surgical treatment. A total of 11 syringo-peritoneal shunts were done in 8 patients of whom 5 patients improved neurologically. It was noticed that 4 of 5 successful syringo-peritoneal shunts were placed in the caudal level of the syrinx. In conclusion, syringo-peritoneal shunt may be at present an optimal mode of surgical management for syringomyelia secondary to adhesive arachnoiditis. In addition, we would like to recommend that follow-up serial MR imaging be done for patients having adhesive arachnoiditis in order to detect syringomyelia as early as possible.

Arachnoiditis↗
PubMed1993

[Hygienic handling in cardiac surgery].

Some points regarding the hygienic handling in cardiac surgery are mentioned. The sternal infection or mediastinitis is still one of the most important complications after cardiac operation especially when ITA is used for CABG. After we paid much attention to these points, the postoperative sternal infection has decreased obviously.

Cardiac Surgical Procedures↗
PubMed1993

[Usefulness and limitation of MR imaging and MR angiography in diagnosis of juvenile moyamoya disease].

Magnetic resonance (MR) images and MR angiograms (MRA) were studied in 20 childhood cases of moyamoya disease. Both MRI and MRA successfully demonstrated moyamoya vessels in the basal ganglia in all cases, with a positive but not definite correlation to the conventional angiographic findings. MRI depicted the stenotic and occlusive lesions of the carotid fork and horizontal portion of the middle cerebral artery effectively. MRA demonstrated some lesions which even MRI failed to prove, but it tended to overestimate the lesions. Post-operative state of collateral flow and the patency of EC-IC bypass graft could be evaluated as accurately with MRA as with conventional angiography, although MRA was limited in spatial resolution and evaluation of flow direction. In conclusion, MRI and MRA were considered to be useful in the diagnosis of moyamoya disease in stage 3 and 4, but less effective in the evaluation of its angiographical stage.

Child↗
PubMed1993

[Diagnosis of intracranial occlusive vascular disease and evaluation of extracranial-intracranial (EC/IC) arterial bypass using three-dimensional magnetic resonance angiography].

The three-dimensional time-of-flight (TOF) magnetic resonance angiograms (MRA) were studied to evaluate its accuracy in the assessment of the intracranial carotid occlusive lesions, collateral circulation and also the patency of extracranial-intracranial (EC/IC) arterial bypass surgery. All occlusive lesions of the intracranial major arteries seen in conventional angiograms were revealed clearly with MRA. However MRA had its practical limitation in the evaluation of the leptomeningeal anastomosis (collateral circulation) probably due to the deterioration of contrast in its slow flow and saturation effect of the magnetization. In addition to that, MRA often exaggerated the severity of the stenotic lesions, mostly in severe cases. The post-operative state of collateral flow and the patency of EC/IC bypass could be evaluated as properly with MRA as with conventional angiography, although MRA was limited in spatial resolution and evaluation of flow direction. In conclusion, MRA was considered t be a reliable non-invasive modality as a screening examination for the evaluation of the carotid occlusive disease and as the follow-up study of the post-operative patients with EC/IC bypass surgery.

Carotid Artery Diseases↗
PubMed1992

Stimulation of the hamster ventral lateral geniculate nucleus induces Fos-like immunoreactivity in suprachiasmatic nucleus cells.

The suprachiasmatic nucleus (SCN) functions as a pacemaker for circadian rhythms in rodents. Its activity and, therefore, circadian rhythms, are synchronized by light information from both a direct retinal projection and an indirect projection from the thalamic intergeniculate leaflet (IGL) and ventral lateral geniculate nucleus (vLGN) (geniculohypothalamic tract; GHT). The GHT also appears to be important for synchronizing circadian rhythms to non-photic cues. Light can activate expression of several immediate-early genes in the SCN, including c-fos. We examined whether electrical stimulation of the IGL/vLGN region would induce Fos-like immunoreactivity (lir) in the hamster SCN. Electrical stimulation was given for one hour during the dark period of the lighting cycle. Stimulation at night of the IGL and adjacent LGN regions induced Fos-lir in cells in the SCN. Labeled cells were found in the dorsolateral part of the caudal SCN, and not in rostral or central regions of the SCN, nor in the ventral part of the caudal SCN. These results indicate that activation of cells contributing to the hamster GHT can induce Fos-lir in a restricted region of the caudal SCN.

Animals↗
PubMed1992

Mouse mammary tumor virus gene expression is suppressed by oligomeric ellagitannins, novel inhibitors of poly(ADP-ribose) glycohydrolase.

Oligomeric ellagitannins (nobotanins B, E, and K) were found to be potent inhibitors of poly(ADP-ribose) glycohydrolase purified from mouse mammary tumor 34I cells. Kinetic analysis revealed that the inhibition of nobotanin B (dimer) was competitive with respect to the substrate poly(ADP-ribose), whereas nobotanin E (trimer) and nobotanin K (tetramer) exhibited mixed-type inhibition. These results suggest that the dimeric structure of ellagitannin may have a functional domain that competes with poly(ADP-ribose) on the poly(ADP-ribose) glycohydrolase molecule. To determine the inhibitory effects of oligomeric ellagitannins on poly(ADP-ribose) glycohydrolase in vivo, we examined their effects on de-poly(ADP-ribosyl)ation of some chromosomal proteins in intact 34I cells that was induced by glucocorticoid treatment. Nobotanin B caused concentration-dependent inhibition of glucocorticoid-induced de-poly(ADP-ribosyl)ation of HMG 14 and 17 and histone H1 in intact 34I cells. Interestingly, this inhibition was associated with suppression of the glucocorticoid-sensitive mouse mammary tumor virus (MMTV) mRNA synthesis. In contrast, nobotanin E and K had little inhibitory effect on either de-poly(ADP-ribosyl)ation of these proteins or induction of MMTV transcription after glucocorticoid treatment. Nobotanin B but not E and K was taken into 34I cells. These results may suggest that the suppression of glucocorticoid-sensitive MMTV transcription results from in vivo inhibition of poly(ADP-ribose) glycohydrolase by nobotanin B. These results also indicate the importance of de-poly(ADP-ribosyl)ation of HMG 14 and 17 and histone H1 in regulation of transcription of the glucocorticoid-sensitive MMTV gene.

Animals↗
PubMed1992

Analysis of novel imidazoles from isolated perfused rabbit heart by two high-performance liquid chromatographic methods.

The paper reports two analytical high-performance liquid chromatographic methods to detect and quantify cardiac-derived histidyl derivatives. Method A relies on relative hydrophobicities as a basis of separation. Method B is an ion-pairing method in which the compounds are eluted in an entirely different order. Fractions collected from method A have been co-eluted in admixture in method B with authentic reference compounds. Thus the existence of the following imidazole ring-containing compounds derived from heart have been confirmed: N-acetylhistidine, N-acetyl-1-methylhistidine, N-acetylcarnosine, N-acetylhomocarnosine, homocarnosine, anserine, carnosine, balenine. Compounds were found in both tissue samples and perfusates.

Animals↗
PubMed1992

Immunological characterization of oviductal glycoproteins associated with the zona pellucida of the golden hamster egg.

Three monoclonal antibodies (MAbs) were produced against materials obtained from the golden hamster oviduct. The MAbs (C11E8, C8B11, and A3D5) selectively reacted with the zona pellucida (ZP) of oviductal eggs. An immunohistochemical study demonstrated that all MAbs bound strongly to the epithelial cells of the oviduct and, to a lesser extent, of the uterus, the cervix, and the vagina. Weak reactions were also observed with some other tissues. All immunohistochemical reactions were completely eliminated by treatment of tissues with periodic acid, suggesting that the antigenic determinants that react with the MAbs are carbohydrate in nature. Antigens that reacted with the MAbs were characterized by immunoblotting analyses of 1- or 2-dimensional polyacrylamide gels after electrophoresis to fractionate tissue extracts under reducing conditions. With the oviductal extract, C11E8 and A3D5 specifically bound to broad bands that corresponded to macromolecules of more than 200 and 160 kD, respectively, whereas C8B11 reacted with a broad range of macromolecules, with the strongest reactivity being detected at molecular weights (MWs) higher than 160 kD. The macromolecules that reacted with the MAbs had carbamilation trains, suggestive of extensive microheterogeneity with respect to charge and size. Similar substances of high MW were not detected in extracts of tissues from the other reproductive organs. In addition, one MAb-positive oviductal antigen bound to the ZP of ovarian eggs, but the others did not bind to the ZP of ovarian eggs. This result indicates that the binding activity is specific for the oviductal glycoproteins. We have thus established clones that produce 3 different MAbs with strong affinity for oviduct-specific glycoproteins, one of which is associated with the ZP of the golden hamster.

Animals↗
PubMed1992

Localization of gene expression of calbindin in the brain of adult rats.

Localization of gene expression of calbindin, a cytosolic calcium-binding protein, was examined throughout the adult rat brain by in situ hybridization with cDNA probes. The gene was expressed most intensely in the Purkinje cells in the cerebellum, intensely in the granule cells of the dentate gyrus, and moderately in the inferior olivary nucleus, in the nuclei of the trapezoid body, in the medial part of the lateral habenular nuclei, entorhinal cortex and in the mammillary nuclei. In addition, weak expression of the gene was widespread in the forebrain and brainstem gray matter, and also in small cells in the spinal posterior horn as well as the ependymal cells. The widespread and heterogeneous expression of the gene in the brain suggests that calbindin is differentially involved in calcium-regulated phenomena in different neurons.

Animals↗
PubMed1992

Examination by scanning electron microscopy of oviductal epithelium of the prolific Chinese Meishan pig at follicular and luteal phases.

The luminal surfaces of epithelial cells in the fimbriae, ampulla, isthmus, and utero-tubal junction of the oviducts of the prolific Chinese Meishan pig at follicular and luteal phases of the estrous cycle were examined by scanning electron microscopy. Marked cyclic changes were observed on the surfaces of cells in the fimbriae and ampulla, but little change was found in the isthmus and at the utero-tubal junction. The cells of the fimbrial epithelium in the follicular phase were densely ciliated, and the cilia partially concealed the bulbous processes of the secretory cells. In the luteal phase, the secretory cells predominated in the epithelium, and most of the ciliated cells were hidden by the processes of the secretory cells. The ampullar epithelium showed similar changes, but to a lesser extent. In the isthmus and at the utero-tubal junction, the secretory cells had many microvilli on their bulbous processes at the follicular phase, but they were flat and the microvilli were fewer in number and shorter in length during the luteal phase. Conspicuous solitary cilia protruded from the surfaces of secretory cells in the fimbriae and ampulla during the luteal phase. These results demonstrate that there are regional variations in the cyclic changes associated with the oviductal epithelial cells of the Chinese Meishan pig.

Animals↗
PubMed1992

Reconsideration of Bell's phenomenon using a magnetic search coil method.

The exact direction, amplitude and time course of Bell's phenomenon is still controversial. We evaluated the eye movements associated with spontaneous blinks, voluntary blinks and prolonged eyelid closure using a magnetic search coil method. Spontaneous blinks were accompanied by transient downward and nasalward eye movements, and similar movement accompanying voluntary blinks were often followed by upward movements. The eye positions occurring immediately after blinks often differed from the initial positions and were followed by corrective saccades, which disappeared when the subjects did not fixate. Prolonged eyelid closure was accompanied by tonic eye elevation and voluntary blinks were accompanied by marked transient eye elevation when eyelid closure was mechanically impeded. Under normal conditions Bell's phenomenon does not occur during blinks.

Adult↗
PubMed1992

Argyrophilic glial intracytoplasmic inclusions in multiple system atrophy: immunocytochemical and ultrastructural study.

Argyrophilic intracytoplasmic inclusions in oligodendrocytes (AGCIs) were seen in all of 15 cases of multiple system atrophy (MSA), and none in other neurodegenerative diseases, including 9 cases of Menzel-type olivopontocerebellar atrophy and 4 cases of Joseph's disease. The inclusions were widespread, not only in the olivopontocerebellar and striatonigral systems but also among fibers connecting their affecting lesions of MSA. Immunohistochemically, they were closely associated with tau, tubulins and microtubule-associated protein 5. Ultrastructurally, they consisted of 30- to 50-nm filaments (not tubules) and electron-dense granules, in varying proportions, and their formation is discussed. The specific occurrence of AGCIs could be a key to approach the pathogenesis of MSA.

Atrophy↗
PubMed1992

Transient appearance of Ca-binding protein (spot 35-calbindin) in bronchial epithelial cells, thyroid parafollicular cells and thymic epithelial cells during the development of rats.

Tracheobronchial epithelium, thyroid organ, thymus, of the developing rats were examined by immunohistochemistry using anti-spot 35 calbindin-antiserum. At E 14, weak to moderate immunoreactivity for spot 35-calbindin was detected in the airway epithelia of the distal half of the trachea and the extrapulmonary bronchus. The immunoreactive cells increased in intensity at E 16-E 21, but decreased markedly after birth. These cells were non-ciliated cells and comprised a majority of the epithelial cells especially in the ventral/cartilaginous portion of the airway. They were characterized by microvilli, vacuoles, granular and agranular endoplasmic reticulum. Typical ciliated cells, which were much less numerous than the immunopositive non-ciliated cells, were immunonegative. In thyroid gland, calbindin-immunoreactive cells first appeared at E 18. They increased in number at E 20-P 1 and decreased gradually after P 7. These cells were the parafollicular cells characterized by numerous secretory granules and situated in close proximity to the basal surface of the follicular cells. In the thymus, immunoreactive cells appeared in the thymic medulla at E 20. They increased in number at P 1, but decreased gradually after P 7. They were stellate in shape and had vesicles, vacuoles, intermediate filaments and represented a subpopulation of thymic reticular epithelial cells. Such a transient appearance of spot 35-calbindin in these cells suggests that this protein may be involved in the regulation of differentiation or may be involved in the process of secretion during the limited developmental period.

Animals↗