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Biomedical subjects

H Abe

Publications and source records attributed to H Abe.

At least 469 records · Page 26Linked to original sources
PubMed1997

Differentiation of cerebral radiation necrosis from tumor recurrence by proton magnetic resonance spectroscopy.

Proton magnetic resonance spectroscopy (1H MRS) was evaluated for distinguishing between radiation necrosis and recurrent glioma in 11 patients after high-dose radiotherapy. Six patients had a histological diagnosis of recurrent glioma. Four patients had a histological diagnosis of radiation necrosis and one had a clinical course consistent with the diagnosis of radiation necrosis. 1H MRS showed cases of radiation necrosis had two characteristic 1H MRS patterns: markedly increased lactate/creatine and phosphocreatine (Cr) ratio and decreased choline-containing compounds/Cr ratio compared to that of recurrent glioma; or all the major metabolites were completely diminished. The N-acetyl aspartate signal was not helpful for differential diagnosis. 1H MRS is a potentially useful method for differentiating tumor recurrence from radiation necrosis in patients treated for malignant glioma.

Adult↗
PubMed1997

Basilar invagination associated with an intercarotid paraganglioma--case report.

A 24-year-old female presented with basilar invagination and kyphoscoliosis of the cervical spine associated with a large intercarotid paraganglioma. She had suffered from pharyngeal discomfort from the age of 9 years due to the tumor. The tumor had originated from the right carotid body and extended in the parapharyngeal space compressing the upper cervical spine. Presumably the slowly growing tumor had caused the kyphoscoliosis and disturbed osseous development of the occipito-atlanto-axial complex, resulting in anterior basilar invagination, hypoplasia of the clivus, and aplasia of the posterior arch of the atlas.

Adult↗
PubMed1997

Childhood ischemic stroke caused by fibromuscular dysplasia of the intracranial artery--case report.

An 8-year-old girl presented with fibromuscular dysplasia of the intracranial vessels manifesting as ischemic stroke. Neuroimaging showed infarction of the right putamen and ipsilateral frontal white matter. Angiography revealed "string of beads" sign involving the terminal portion of the right internal carotid artery and the horizontal segment of the ipsilateral middle cerebral artery. She was treated conservatively. Magnetic resonance angiography at 2 months post ictus showed similar findings in the middle cerebral artery but improvement of the stenosis of the internal carotid artery. Her neurological deficits had almost resolved. Fibromuscular dysplasia should be part of the differential diagnosis of ischemia in children.

Brain Ischemia↗
PubMed1997

Aneurysm of the anterior communicating artery associated with accessory middle cerebral artery--case report.

A 63-year-old female presented with an anterior cerebral artery aneurysm associated with accessory middle cerebral artery. The aneurysm was located on one of the duplicate anterior communicating arteries, and the accessory middle cerebral artery originated from the anterior cerebral artery adjacent to this aneurysm. The recurrent artery of Heubner was not recognized. The accessory middle cerebral artery may have been involved in the genesis of the aneurysm by changing the hemodynamics in the anterior cerebral arteries.

Cerebral Angiography↗
PubMed1997

Effectiveness of fibrin glue for preventing postoperative extradural fluid leakage.

Cerebrospinal fluid (CSF) leakage through dural sutures after craniotomy increases the risk of complications such as persistent CSF fistulas, meningitis, and subcutaneous, graft bone, or epidural infections. The effectiveness of fibrin glue for preventing CSF leakage through dural closure was investigated in 183 patients who underwent frontotemporal craniotomy for unruptured aneurysm. Fibrin glue was used in 138 patients, but not in the other 45. Computed tomography was used to evaluate postoperative extradural fluid collection as a minimal volume of low-density area. Postoperative computed tomography demonstrated transient increases in extradural fluid collection in 55 patients. However, none of these patients received a second surgery for dural repair. Fluid collection occurred in 19 of 45 patients (42%) in whom fibrin glue was not used, and in 36 of 138 patients (26%) in whom fibrin glue was used. The fibrin sealant on the dural suture was a significant factor in reducing the incidence of the fluid leakage (p < 0.05, chi-square test). Fibrin glue is a useful surgical tool for the prevention of postoperative extradural fluid collection through the dural sutures.

Cerebrospinal Fluid↗
PubMed1997

Molecular cloning and mRNA expression of the bovine insulin-responsive glucose transporter (GLUT4).

Insulin-response glucose transporter GLUT4 is a member of the glucose transporter family (GLUT) and is present exclusively in muscle and adipose tissue. It is a target of insulin action in humans and rodents. To clarify the molecular structure of bovine GLUT4, its GLUT4 cDNA was cloned by the RT-PCR method. Several cDNA clones corresponding to the different regions of GLUT4 were obtained by amplifying reverse-transcriptase products of RNA extracted from Holstein cattle skeletal muscle. Nucleotide sequence analysis of the cDNA clones revealed that bovine GLUT4 cDNA was composed of 2,656 base pairs with a coding region for a 509 amino acid protein. The deduced amino acid sequence was 64% and 92% identical with bovine GLUT1 (GLUT ubiquitously expressed in all tissues) and rat GLUT4, respectively. Although the amino acid sequence of the GLUT4 COOH-terminal region is highly conserved among the species so far reported, one amino acid (Asp) of the region was replaced by His in bovine GLUT4. The tissue distribution of GLUT4 was also examined by Northern blot analysis using a probe prepared from the bovine cDNA. GLUT4 mRNA was detected in skeletal muscle, heart, and adipose tissue, but not in liver, kidney, lung, brain, or spleen. Such a distribution is essentially the same as in humans and rodents, suggesting that GLUT4 is an insulin-responsive glucose transporter in cattle.

Adipose Tissue↗
PubMed1997

Hypoglossal-facial nerve side-to-end anastomosis for preservation of hypoglossal function: results of delayed treatment with a new technique.

This report describes a new surgical technique to improve the results of conventional hypoglossal-facial nerve anastomosis that does not necessitate the use of nerve grafts or hemihypoglossal nerve splitting. Using this technique, the mastoid process is partially resected to open the stylomastoid foramen and the descending portion of the facial nerve in the mastoid cavity is exposed by drilling to the level of the external genu and then sectioning its most proximal portion. The hypoglossal nerve beneath the internal jugular vein is exposed at the level of the axis and dissected as proximally as possible. One-half of the hypoglossal nerve is transected: use of less than one-half of the hypoglossal nerve is adequate for approximation to the distal stump of the atrophic facial nerve. The nerve endings, the proximally cut end of the hypoglossal nerve, and the distal stump of the facial nerve are approximated and anastomosed without tension. This technique was used in four patients with long-standing facial paralysis (greater than 24 months), and it provided satisfactory facial reanimation, with no evidence of hemitongue atrophy or dysfunction. Because it completely preserves glossal function, the hemihypoglossal-facial nerve anastomosis described here constitutes a successful approach in patients with long-standing facial paralysis who do not wish to have tongue function compromised.

Adult↗
PubMed1997

Cerebral abscess as an unusual complication of coil embolization in a dural arteriovenous fistula. Case report.

This 63-year-old man presented with a right temporoparietal cortical infarction. A dural arteriovenous fistula involving the right transverse sinus was diagnosed on cerebral angiography. Transvenous embolization using detachable coils was performed; however, postembolization angiograms demonstrated retrograde filling of a cortical draining vein that was not seen on initial angiography. The patient subsequently developed a cerebral abscess in the region of the previous cortical infarction 2 months after the embolization. The abscess was successfully treated with drainage and antibiotic therapy. The authors report this case to illustrate an unusual complication associated with this procedure and the possible contribution of the cortical draining vein in the pathogenesis of the cerebral abscess.

Angiography, Digital Subtraction↗
PubMed1997

Management of primary intracranial germinomas: diagnostic surgery or radical resection?

Because intracranial germinomas are readily curable with radiation and chemotherapy or radiation therapy alone, the role of radical surgery has become debatable. This study assesses the optimum degree of surgical resection for intracranial germinomas. Twenty-nine patients who underwent surgery for germinoma were retrospectively analyzed (male/female ratio 27:2, median age 18 years). Among these 29 patients there were 10 solitary pineal, seven solitary neurohypophyseal/hypothalamic, and 12 multifocal or disseminated tumors. Biopsy samples were obtained in 16 patients (stereotactically in eight, transsphenoidally in four, and via frontotemporal craniotomy in four). Partial resection was attained in five patients (via a frontotemporal approach in three and occipitotranstentorially in two). Gross-total resection was achieved via an occipitotranstentorial route in eight patients with pineal masses. After surgery, 10 patients were treated with radiotherapy alone, and 19 received radiation and chemotherapy; complete remission was achieved in all 29 patients. The overall tumor-free survival rate was 100% at a median follow-up period of 42 months. There was no significant difference in outcome related to the extent of surgical resection. Postoperative neurological improvement was seen in only two patients, whereas transient postoperative complications, mainly upgaze palsy, were observed in six. One patient experienced a slight hemiparesis, bringing the surgical morbidity rate to 3% (one of 29). It is concluded that radical resection of intracranial germinomas offers no benefit over biopsy. The primary goal of surgery should be to obtain a sufficient volume of tumor tissue for histological examination. If there is strong evidence of germinoma on radiological studies, biopsy samples should be obtained. When a perioperative histological diagnosis of pure germinoma is made during craniotomy, no risk should be taken in continuing the resection.

Adolescent↗
PubMed1997

[Distribution of cell adhesion glycoproteins in the human retrobulbar optic nerve].

We examined the immunohistochemical distribution of six types of cell adhesion glycoproteins in the human retrobulbar optic nerve. The pial septa had laminin and entactin on the surface at the border with the optic nerve fibers, and fibronectin and vitronectin were distributed in the stroma of the septa. Some tenastin was also detectable both on the surface and in the stroma of the septa. Thrombospondin was associated with capillaries within the stroma. The surface of the arachnoid membrane, the pia mater, and the dura mater was covered by laminin and entactin. Diffuse staining with antifibronectin antibody was seen in all these meningeal tissues, but vitronectin showed a fine fibrillar appearance in these tissues. No significant staining could be found for tenastin. Thrombospondin showed only faint staining on the capillaries of the pia mater and the dura mater. These findings can provide clues for the discussion of how the extracellular matrix works and what roles it plays in disorders involving the retrobulbar optic nerve, such as optic neuritis and glaucoma.

Cell Adhesion↗
PubMed1997

Severe hemolysis due to artificial chordae displacement.

Hemolytic anemia is a well-recognized complication of mechanical heart valve prosthesis but, as yet, has not been reported after mitral valve repair with chordal replacement. We report a case of severe hemolytic anemia after mitral valve repair with chordal replacement and Carpentier-Edwards annuloplasty ring insertion. Progressive prolapse of the anterior leaflet due to the artificial chordae being too long caused recurrent regurgitation which was responsible for the hemolysis. The patient also had idiopathic thrombocytopenic purpura, but successful second mitral valve repair was performed after high-dose gamma-globulin therapy.

Anemia, Hemolytic↗
PubMed1997

Full functional recovery after surgical repair of transected abducens nerve: case report.

OBJECTIVE AND IMPORTANCE: Results of surgical repair of the injured abducens nerve are rarely reported in the literature. A full functional recovery of a completely resected abducens root may be exceptional. We describe a patient who obtained normal ocular alignment and binocular vision after surgical reconstruction of a transected abducens nerve. CLINICAL PRESENTATION: A 56-year-old woman with a petroclival meningioma was presented. She underwent total removal of the tumor through a combined supra/infratentorial transpetrosal approach. The abducens nerve was tightly attenuated by the tumor and thickened dura. During dissection, the nerve was completely transected just behind the entrance to Dorello's canal. INTERVENTION: The abducens nerve was the single root type and inevitably required surgical repair. To obtain a sufficient length of the distal stump for trimming, part of the petrosphenoidal ligament was cut and the superior border of the petrous bone was exposed. The proximal stump of the nerve was also trimmed to obtain healthy tissue, and reconstruction was performed with five 10-0 nylon sutures. Five months later, esodeviation began to improve. Nine months after the surgery, the patient did not complain of diplopia and an objective assessment reported normal ocular alignment and estimated binocular function as "excellent" according to Biglan's system. Overcorrection of abduction did not occur. CONCLUSION: The result in our patient confirms the possibility of full functional recovery after surgical repair of a totally transected abducens nerve.

Abducens Nerve↗
PubMed1997

[Expression of proteinase inhibitors in the human trabecular meshwork].

We examined the distribution and expression of three proteinase inhibitors, alpha 1-proteinase inhibitor (alpha 1-PI), alpha 1-antichymotrypsin (alpha 1-ACT), and alpha 2-macroglobulin (alpha 2-M) in the human trabecular meshwork. Immunohistochemistry, in situ hybridization, and reverse transcription-polymerase chain reaction (RT-PCR) were used. By immunostaining, all three inhibitors were identified in the human trabecular meshwork with enhanced staining in the uveal meshwork. In situ hybridization showed mild but positive accumulation of the silver grains on the trabecular meshwork cells, which indicates mRNA expression. Specific distribution or cell selectivity were not detectable probably due to weak expression of these inhibitors in this tissue. Instead mRNAs for alpha 1-PI, alpha 1-ACT, and alpha 2-M as well as antithrombin III, plasminogen activator inhibitor-1 could be identified by RT-PCR using trabecular meshwork culture cells. In this study, we concluded that some proteinase inhibitors were distributed in the human trabecular meshwork as well as in the cornea and the ciliary body. At least part of these were probably produced by the trabecular meshwork cells. The balance between proteinases and proteinase inhibitors might play an important role even in the human trabecular meshwork to maintain the outflow route. The alterations in the primary or secondary glaucomatous eyes are curious.

Adolescent↗
PubMed1997

[Anticancer drug-induced colitis--case report and review of the literature].

We encountered two chemotherapy cases related to anticancer drug-induced colitis. Case 1 was a 35-yo-female with a recurrence of ovarian cancer. She was treated with intraarterial infusion consisting of continuous 5-fluorouracil (250 mg/day 5 days/week x 4) following low-dose consecutive cisplatin (20 mg/day 5 days/ week x 1). The catheter was inserted into the abdominal aorta about 2 cm above the carina of the common iliac arteries. Six weeks after the start of chemotherapy, severe abdominal pain and melena occurred. Case 2 was a 68-yo-female with an endometrial cancer recurrence. The same intraarterial chemotherapy used in case 1 was was initiated. Four weeks after the start of chemotherapy, before intraarterial infusion of CDDP, she suffered from constipation and than diarrhea, abdominal pain and melena. Both cases were diagnosed as anticancer drug-induced colitis with the pathological findings from colon biopsy and the clinical course, and improved in about 1 month with the discontinuation of intraarterial infusion, fasting and TPN. Intraarterial infusion of only CDDP caused both patients no intestinal symptoms, so it is supposed that intraarterial infusion of 5-fluorouracil induced the colitis. Anticancer drug-induced colitis should be taken into consideration as a rare but possible course of chemotherapy-related complication with intraarterial infusion of 5-fluorouracil.

Adult↗
PubMed1997

Reappraisal of p53 mutations in human malignant astrocytic neoplasms by p53 functional assay: comparison with conventional structural analyses.

We previously reported clonal expansion of p53 mutations in malignant astrocytic tumors detected with a yeast p53 functional assay that measures mutant p53 alleles quantitatively and loss of p53 transcriptional competence qualitatively (Tada et al., Int J Cancer 67:447-450, 1996). This method selectively detects inactivating mutations and is relatively insensitive to contamination of tumor samples with normal tissue. To determine whether the mutation frequency and spectrum detected in this way differ from those seen with conventional techniques, 54 malignant astrocytomas were tested with the yeast assay, and the abnormalities detected were characterized by DNA sequencing. Inactivating p53 mutations were found in 67% of anaplastic astrocytomas and 41% of glioblastomas. Overall, mutations were found in 48% of tumors, compared with only 29% in previous studies (P < 0.005), a difference that probably reflects the greater sensitivity of the yeast assay than of conventional techniques. The frequency of mutations in anaplastic astrocytomas (in our study plus published studies) was significantly higher than in glioblastomas (39% vs 29%; P < 0.05). This suggests that acquisition of p53 mutations is not rate limiting for progression to glioblastoma and that many glioblastomas develop by p53-independent pathways. Sequencing of mutant p53 cDNAs rescued from yeast showed that the mutation spectrum for functionally inactive mutants was nearly identical to the spectra from previous studies on structural mutants, indicating that transcriptional activity is the critical biological target of p53 mutation in malignant astrocytomas.

Adult↗
PubMed1997

Establishment of three monoclonal antibodies specific for prespermatogonia and intratubular malignant germ cells in humans.

Intratubular malignant germ cells (ITMGC), as assessed by clinicopathologic or cytogenetic studies, are regarded as a preinvasive lesion of all human testicular germ cell tumors with the exception of yolk sac tumors (in infants) and spermatocytic seminomas. To characterize specific surface molecules of ITMGC, we raised three mouse monoclonal antibodies (mAb) against NCR-G3 (G3), a multipotent, human embryonal carcinoma (EC) cell line, and screened cryostat sections of human testicular tissue containing ITMGC. These three mAb (HB5, IgG1; HF2, IgG1; HE11, IgG1) reacted to the surface of ITMGC, seminomas, and EC in vivo as well as to human EC cell lines in vitro. Expression of HB5 and HF2 antigens was down-regulated during cellular differentiation of G3 cells by retinoic acid or N,N'-hexamethylene-bis-acetamide treatment, whereas that of HE11 antigen was up-regulated with cellular differentiation by retinoic acid. Furthermore, these three mAb reacted to stage-specific prespermatogonia in the human fetus but not in human adults. HB5, HF2, and HE11 antigens were shown to be glycoproteins with molecular weights of approximately 80, 80, and 70 kd, respectively, and could be immunoprecipitated after deglycosylation treatment. Peptide mapping with Staphylococcus aureus V8 protease suggested that the HB5 and HF2 antigens were identical. We concluded that HB5/HF2 and HE11 antigens are oncodevelopmental antigens in testicular germ cell tumors and human spermatogenesis that may play a significant role in tumorigenesis and the development of human germ cells.

Adult↗
PubMed1997

[Posterior iris bowing after accommodation--elucidation of the etiology of pigment dispersion syndrome].

Recent advancements in imaging the anterior segment structures using the ultrasound biomicro scope (UBM) have proven the involvement of posterior iris bowing due to reverse pupillary block as the cause of pigment dispersion syndrome. In this report, we examined whether the posterior iris bowing occurs even in normal eyes following accommodation, and whether the degree of iris concavity tends to be greater in myopic eyes than in emmetropic eyes. The subjects were normal eyes with sufficient accommodation power, i.e. 5 myopic eyes with less than-5 diopter reflection, 5 emmetropic eyes within +/- 1 dioptor reflection, respectively. We obtained UBM images of the iris at 4 portions before and after accommodation, and measured the degree of posterior iris bowing. We found that almost all data shift posteriorly after accommodation, and that the iris concavity is more distinct in myopic eyes than in emmetropic eyes both before and after accommodation (before: p = 0.0004, after: p < 0.0001). From these results, we confirmed that iris concavity after accommodation occurs in normal eyes but not enough for iridozonular contact, and that pigment dispersion syndrome results from augmented iris concavity owing to pre-existing factors such as iris flexibility, myopia, and sufficient accommodation power.

Accommodation, Ocular↗