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Biomedical subjects

H Abe

Publications and source records attributed to H Abe.

At least 307 records · Page 17Linked to original sources

Results of the surgical treatment of perimedullary arteriovenous fistulas with special reference to embolization.

OBJECT: This retrospective study was performed to evaluate the results of surgical treatment and the use of preoperative embolization in managing patients with perimedullary arteriovenous fistulas (AVFs). METHODS: The authors studied 20 consecutive patients with perimedullary AVFs who underwent surgical treatment. Arteriovenous shunts were at the level of the cervical spine in five patients, the thoracic spine in 12, and the conus medullaris in three patients. Of the 20 AVFs, three were fed by the anterior spinal artery only, three by the posterior spinal artery, and 14 by both the anterior and posterior spinal arteries. Nine patients had varices that compressed the spinal cord. Eleven patients underwent surgery, and nine patients underwent surgery combined with adjuvant preoperative embolization. Preoperative embolization remarkably reduced blood flow through the AVFs and facilitated subsequent surgical procedures. Postoperative angiography revealed complete disappearance of the AVFs in 16 patients. However, small fistulas persisted in the other four patients, whose large lesions were fed by the anterior spinal artery. Postoperatively, neurological status was improved in 11 patients, unchanged in eight, and worse in one patient. CONCLUSIONS: Effective interruption of a spinal arteriovenous shunt was achieved by surgery in all cases, even when the anterior spinal artery was involved. For large and high-flow AVFs, embolization proved to be a useful adjunct to surgery.

Adolescent↗

Detection of a sequence involved in actin-binding and phosphoinositide-binding in the N-terminal side of cofilin.

Cofilin is an actin-binding protein of low molecular weight which is widely distributed in eukaryotes and is deeply involved in the dynamics of actin assembly in the cytoplasm. The actin-binding ability of cofilin is inhibited by inositol phosphates (PIP2), and the PIP2- and actin-binding site(s) has been localized in residues W104-M115 of the cofilin primary sequence (Yonezawa et al. 1991 ). In the present study, in order to further clarify the functional domains in cofilin molecule, we constructed expression vectors containing cDNAs of different size with deletion at the 3'-region of the open reading frame. The truncated cofilin molecules produced in E. coli were purified and examined for their actin-binding and PIP2-binding ability. We found that the truncated cofilin molecule without C-terminal residues #100-#166 including the previously-described actin-binding site could be cross-linked with actin by EDC, a zero-length cross-linker. In addition, these truncated peptides as well as synthetic peptides corresponding to the N-terminal sequence of cofilin suppressed the inhibitory action of PIP2 on actin-cofilin interaction. These results strongly suggest that additional actin- and PIP2-binding sites exist in the N-terminal region of cofilin.

Actin Depolymerizing Factors↗

[Changes in transforming growth factor-beta and platelet-derived growth factor in the optic nerve head in monkey experimental glaucoma].

PURPOSE: Remodeling of the extracellular matrix occurs in the lamina cribrosa in progressed glaucomatous optic nerve damage including disc cupping. We examined immunohistochemical changes in the transforming growth factor (TGF)-beta and platelet derived growth factor (PDGF) in the optic nerve heads in experimentally induced glaucoma. METHODS: We used 3 cynomolgus and 2 Japanese monkey eyes. Glaucoma was induced by repeated argon laser photocoagulation of the chamber angle. Eyes were enucleated after disc cupping had formed 3 to 5 months after treatment. The optic nerve head was examined for expression of TGF beta 1, beta 2, and beta 3, and PDGF A and B in frozen sections and by the biotin-ExtrAvidin-Alkali Phosphatase method. FINDINGS: Normal monkey eyes showed TGF beta 1, beta 2, and beta 3, and PDGF A, and B in the optic nerve head including the nerve fibers, glial cells, and vascular cells. Glaucomatous eyes showed stronger expression of TGF beta 1 and beta 2 in the glial cells around the lamina cribrosa. The staining intensities for TGF beta 3, PDGF A, and PDGF B were the same as in normal eyes. CONCLUSION: Eyes with experimental glaucoma showed higher expressions of TGF beta 1 and beta 2 around the lamina cribrosa. This finding may show upregulation of extracellular matrix production as related to remodeling of the lamina cribrosa in glaucoma.

Animals↗

[Multifocal electroretinograms in patients with branch retinal artery occlusion].

PURPOSE: We recorded multifocal electroretinograms (m-ERGs) in patients with branch retinal artery occlusion (BRAO) and compared the waveform in the area of retinal artery occlusion with that in the normal area, to evaluate the influence of the damage of the inner retina on the m-ERG. SUBJECTS AND METHODS: Three patients who had normal visual acuity and visual field loss of more than one quadrant due to BRAO were examined. The waveform of first-order and second-order kernel responses of m-ERG in the area of retinal artery occlusion were compared with those of the vertically symmetrical, normally perfused area of the same eye. RESULTS: Prolongation of latency and decrease of amplitude were noted for the first negative wave (N 1), the first positive wave (P1), and the second negative wave (N2) in the first-order kernel responses in the area of retinal artery occlusion in comparison with the normally perfused area. Second-order kernel responses were not detected in the area of retinal artery occlusion. CONCLUSIONS: The damage to the inner retina affected portions N1, P1, and N2 of the first-order kernel responses, and N2 was the most seriously affected. Second-order kernel responses appear to reflect more strongly the function of the inner retina.

Child↗

[Cerebrospinal fluid analysis in Kirisawa-Urayama type uveitis].

PURPOSE: We investigated whether viral encephalitis could occur in patients with Kirisawa-Urayama type uveitis by analysing the cerebrospinal fluid (CSF). METHODS: CSF samples were aspirated from nine patients with Kirisawa-Urayama type uveitis and assayed for local antibody production and the presence of herpesvirus DNA. RESULTS: Seven cases had mild CSF pleocytosis. In six of seven cases who underwent CSF antibody analysis, we found intrathecal antibody production against herpes simplex virus or varicella-zoster virus which were the causative viruses diagnosed from intraocular fluid in each patients. Polymerase chain reaction (PCR) assay was used to search for virus DNA in the CSF of six patients, but all were negative. CONCLUSIONS: The results of this study suggest that Kirisawa-Urayama type uveitis is often accompanied with optic nerve involvement and intrathecal antibody production against causative viruses, but we could not find any viral encephalitis.

Adult↗

Embolization of cerebral arteriovenous malformations achieved with polyvinyl alcohol particles: angiographic reappearance and complications.

BACKGROUND AND PURPOSE: The appropriate choice of embolic materials with respect to the permanency of obliterated nidi after embolization and complications related to the procedure is essential for safe and effective embolization of cerebral arteriovenous malformations (AVMs). Our purpose was to ascertain the recanalization and complication rates after AVM treatment with polyvinyl alcohol (PVA) particles. METHODS: Between 1988 and 1994, 36 AVMs were embolized with PVA particles at our institution. Follow-up angiographic findings and occurrence of complications during the embolization procedures were analyzed retrospectively. RESULTS: Complete obliteration of the nidus immediately after embolization was achieved in five patients, and 80% to 99% obliteration was attained in 12 patients. Fifty-one follow-up angiographic examinations were performed 1 week to 60 months (mean, 7 months) after embolization in 31 patients. An increase in nidal size was seen on 15 follow-up angiograms (29%) and a decrease was seen in seven (14%). In 28 of the 51 angiograms obtained more than 1 month after follow up (mean, 13 months), 12 (43%) showed AVM enlargement. In four (80%) of five cases of complete obliteration, nidi reappeared on follow-up angiograms. Hemorrhagic complications occurred in three cases and ischemic ones in seven. One patient (3%) died and five (14%) suffered persistent neurologic deficits. CONCLUSION: Embolization with PVA particles can produce significant volume reduction in AVM nidal size, but recanalization is a distinct possibility.

Adolescent↗

The reticuloendothelial system and macrophage-monocyte system in thorotrast patients.

To evaluate the function of the reticuloendothelial system and macrophage-monocyte system, blood samples from Thorotrast patients and age-matched healthy controls were used to determine the titer of plasma antibodies to lipid A and the numbers of several lymphocyte subclasses in peripheral blood and for an autoradiographic study of peripheral blood monocytes. The titer of plasma IgM class antibodies to lipid A was significantly elevated in the Thorotrast patients. Counts of CD 11-positive lymphocytes and CD 57-positive lymphocytes, which correspond to monocytes and natural killer cells, respectively, were significantly increased in the Thorotrast patients. Autoradiography showed that alpha-particle tracks were emitted from the monocytes isolated from the peripheral blood of Thorotrast patients. Thus the depressed function of the reticuloendothelial system resulted in the activation of the macrophage-monocyte system in the Thorotrast patients.

Aged↗

[Observation of human corneal and scleral collagen fibrils by atomic force microscopy].

PURPOSE: We attempted to analyze the three-dimensional ultrastructure of human corneal and scleral collagen fibrils with an atomic force microscope (AFM). METHODS: A normal eye removed from a 66-year-old male was used in the study. Suspended corneal and scleral collagen fibrils were individually attached to glass slides by centrifugation. These collagen fibrils were air-dried and observed with a non-contact mode AFM in air. RESULTS: AFM imaging provided information on the surface topography of both corneal and scleral collagen fibrils. The corneal collagen fibrils had a height of 11.9 +/- 1.0 (mean +/- standard deviation) nm and the scleral fibrils of 82.5 +/- 35.6 nm. A periodic banding pattern of grooves and ridges was clearly found in both types of fibrils; the D-periodicity and the groove depth were 65.7 +/- 0.8 nm and 1.46 +/- 0.50 nm in the corneal fibrils, and 67.3 +/- 1.1 nm and 6.16 +/- 1.23 nm in the scleral fibrils. CONCLUSIONS: Surface topographic images of human corneal and scleral collagen fibrils were clearly obtained with the AFM. This technique provides quantitative information on the surface morphology of the collagen fibrils at high resolution.

Aged↗

[Digital recording in neurosurgery].

The purpose of this study is to examine the image quality of multi-media for digital recording of surgical procedure using an operating microscope in neurosurgery. For video recording, high vision recording, digital video recording and analogue VHS recording were used. For still pictures, an analogue camera with 35 mm silver halide film and a micro-digital camera were used. The quality of photographs taken with a microdigital camera was superior to the quality of those taken with the conventional 35 mm film camera. The micro-digital camera system is superior to the conventional 35 mm camera in neurosurgery in its quality and success rate. In video recording, high vision analogue recording was superior to any other media as far as its image quality is concerned although its practical convenience is limited and cost performance is not always good. On the other hand, digital video can record high quality images, including still pictures, with satisfactory quality to the neurosurgeon. These digital recording media are also space saving for storing the huge amount of data obtained during surgery and the cost-performance is superior to that of the conventional method. In the near future, most of surgical procedures are supposed to be expected using digital media.

Humans↗

[Midterm achievement and problems of all municipal health and welfare plans for the elderly in Yamagata Prefecture].

PURPOSE: This study was made for providing information in the preparation of Social Welfare Systems in municipalities. METHODS: Based on seven official reports by Yamagata Prefecture, quantitative data on health and welfare services were analyzed. We investigated the midterm achievement and problems of a Municipal Health and Welfare Plan for the Elderly in all 44 municipalities by mail survey (response rate 100%). The questionnaire included the progress situation of the plan, the existence of an assessment organization, and the characteristics of the plan. RESULTS: Both health service and welfare service achieved targets level to a degree. Concerning the progress situation, "The midterm achievement is not satisfactory" for 65.9% (29 municipalities). The main reasons were "budgets" (93.1%, 27 municipalities) and "lack of manpower" (75.9%, 22 municipalities) all of which indicates "lack of home helpers". 58.6% of all 44 municipalities were reconsidering the plan. In assessment organization existed in 31.8% (14 municipalities) of all municipalities. CONCLUSION: It is necessary that analysis should consider not only use of quantitative data but also qualitative one. The major problems found are that community characteristics were not reflected and the opinion of inhabitants were not considered.

Health Planning↗

[An autopsy case of aortitis resulting in a tear of the aortic valve due to a rupture of the aneurysm of Valsalva's sinus].

A 43-year-old man was admitted to a hospital because of acute dyspnea and nocturnal orthopnea. Echocardiogram and chest CT showed the dilation of thoracic aorta from the root to ascending portion. On the third hospital day, he died suddenly. At autopsy, the cause of death was indicated to be a tear of an aortic valve due to a rupture of the aneurysm of Valsalva's sinus, followed by acute aortic regurgitation and acute cardiac insufficiency. Histopathological findings of thoracic aorta revealed mesoaortitis, characterized by patchy destruction of the media with a moth-eaten appearance of the medial elastic laminae and a microgranuloma formation, a perivascular mononuclear cell infiltration of the vasa vasorum, and a fibrous thickening of the intima and adventitia. However, there were no abnormalities in main branches of aorta and abdominal aorta, and no systemic vasculitis. This case is a rare one in the clinical course, and may be important to be differentiated from other cases with aortitis, especially Takayasu arteritis and syphilitic aortitis.

Acute Disease↗

Leptin stimulates basal and GHRH-induced GH release from cultured rat anterior pituitary cells in vitro.

Leptin, the product of ob gene, is secreted from adipocytes and appears to regulate food intake and energy expenditure through its receptor in the hypothalamus. In addition, leptin is reported to modulate pituitary hormones including LH, FSH and ACTH, probably via the hypothalamus. In obesity, growth hormone (GH) secretion is impaired, while serum leptin levels are elevated. To investigate the possibility that leptin serves as a metabolic signal that influences GH secretion from the pituitary, we studied the effect of leptin on GH secretion from primary monolayer cultures of rat anterior pituitary cells. Twenty micrograms/ml leptin increased GH secretion, but did not increase GH release at a physiological concentration up to 200 ng/ml. However, 200 ng/ml leptin stimulated GH release in the presence of GH-releasing hormone (GHRH) ranging from 10(-8) to 10(-7) M. Twenty ng/ml leptin tended to increase 10(-7) M GHRH-induced GH release, whereas 20 ng/ml leptin did not increase either 10(-9) or 10(-8) M GHRH-induced GH release. This result suggests that leptin has a direct effect on the pituitary to enhance GHRH-induced GH secretion.

Analysis of Variance↗

Circadian rhythm and light responsiveness of BMAL1 expression, a partner of mammalian clock gene Clock, in the suprachiasmatic nucleus of rats.

To clarify whether BMAL1 is involved in the photic signal transduction in the mammalian circadian clock, we examined the effects of a single light pulse on the level of BMAL1 mRNA in the suprachiasmatic nucleus (SCN) of rats by in situ hybridization. Rats were exposed to 30 min light of ca. 300 lux at six different phases in constant darkness and decapitated 60 min later. BMAL1 transcripts in the SCN of the control animals showed a robust circadian oscillation with the highest expression at ZT (Zeitgeber time) 18 and the lowest at ZT2. The light pulse slightly increased the level of BMAL1 transcripts in the SCN. However, the increment did not depend on the phase of light pulse. There was no significant change in the BMAL1 mRNA level up to 120 min after a light pulse at ZT14 and ZT22. These results indicate that BMAL1 transcription is not involved in the photic signal transduction responsible for non-parametric entrainment of the circadian clock in rats.

ARNTL Transcription Factors↗

Cloning and characterization of the 5'-flanking region of the human growth hormone secretagogue receptor gene.

Recently, the growth hormone secretagogue receptor (GHS-R) cDNA has been isolated from the pituitary and hypothalamus. To evaluate the regulation of human (h) GHS-R gene expression, we cloned the hGHS-R gene containing the 5'-flanking region of 0.6-2.9 kilobase pairs. Analysis of the hGHS-R transcripts with 5'-rapid amplification of cDNA ends suggested that the putative transcription initiation site was approximately -453 base pairs upstream of the translation initiation site (+1). There is no typical TATA, CAAT, or GC box but an initiator-like sequence and putative binding sites for several transcription factors around the putative transcription start site. The 5'-flanking region inserted into a luciferase reporter vector had promoter activity in GH3 cells but had activity indistinguishable from background in HeLa or EP1 cells. The hGHS-R promoter activity in GH3 cells increased by deletion of nucleotides from -1224 to -734, whereas it was decreased by further deletion from -734 to -608. Knowledge of the promoter region of the hGHS-R gene will facilitate elucidation of its transcriptional control.

Base Sequence↗

Pirmenol hydrochloride-induced QT prolongation and T wave inversion on electrocardiogram during treatment for symptomatic atrial fibrillation.

Pirmenol hydrochloride is a new orally effective, long-acting antiarrhythmic agent currently used in patients with supraventricular and ventricular tachyarrhythmias. We report on a 56-year-old female who exhibited drug refractory paroxysmal atrial fibrillation, in which marked prolongation of the QT interval and T wave inversion on electrocardiogram was demonstrated reproducibly shortly after the administration of oral pirmenol therapy. The plasma concentration of pirmenol was at a subtherapeutic level and the lymphocyte stimulation test was positive in this patient. Thus, an immunological mechanism might be involved in the mechanism of pirmenol-induced QT prolongation and T wave inversion on the electrocardiogram.

Anti-Arrhythmia Agents↗