Biomedical subjects

H Abe

Publications and source records attributed to H Abe.

At least 271 records · Page 15Linked to original sources

PubMed1999

Collagen fibrillar network in the optic nerve head of normal monkey eyes and monkey eyes with laser-induced glaucoma--a scanning electron microscopic study.

PURPOSE: To examine the three-dimensional organization of collagen fibrils in the lamina cribrosa of normal monkey eyes and monkey eyes with laser-induced glaucoma. METHODS: Intraocular pressure elevation and glaucomatous optic discs were obtained in one eye of three adult monkeys by repeated applications of argon laser to the chamber angle. The monkey eyes were enucleated, and the collagen fibrillar network was investigated by scanning electron microscopy after cell maceration with 10% sodium hydroxide and conductive staining. RESULTS: In normal monkey eyes, round to oval shaped regular laminar pores through which axon bundles exited were observed in the lamina cribrosa. The straight, column-like pores or openings were formed by multilayered laminar plates that aligned vertically in parallel with the optic nerves. The surface of the laminar plates was covered by delicate, loosely arranged collagen fibrils. The inner surface of the pores was smooth, made up of well-packed collagen fibers. In glaucomatous eyes, the laminar pores were clogged by tightened collagen fibrils. The inner surface of the pores was irregular, and the pores were narrowed or distorted. CONCLUSIONS: Alterations in the three-dimensional organization of collagen fibrils were demonstrated in the optic nerve head of glaucomatous monkey eyes. The architectural changes may affect the flexibility and resilience required of the lamina cribrosa in supporting optic nerve fibers.

Animals↗

PubMed1999

Syringo-subarachnoid shunt for syringomyelia using partial hemilaminectomy.

Syringo-subarachnoid shunt (S-S shunt) is one of the established surgical procedures for syringomyelia. However, this procedure requires a laminectomy which may lead to spinal column complications. We present a modified form of S-S shunt using a partial hemilaminectomy; a S-S shunt is placed via the dorsal root entry zone into the anterior subarachnoid space which is considered to be an ideal site for the drainage of the syrinx fluid. This technique will decrease the incidence of neuronal and spinal complications after surgery and avoid subarachnoid adhesions around the shunt tube. Between 1992 and 1997, a total of 24 patients with syringomyelia have been treated with this surgical procedure without any complications. Collapse of the syrinx was achieved in all cases. The authors believe that the procedure is an effective surgical treatment for syringomyelia and can be applied safely to adolescent and child cases.

Adolescent↗

PubMed1999

Effects of propranolol on cardiovascular and neurohumoral actions of alcohol in hypertensive patients.

Alcohol ingestion acutely lowers blood pressure (BP) with vasodilation and sympathetic activation in Oriental subjects. We examined the effects of beta blockade on cardiovascular and neurohumoral actions of alcohol in Japanese men with mild-to-moderate essential hypertension. Ten hypertensive patients (54+/-5 years, mean+/-SE) were given 1 ml/kg of alcohol or isocaloric control drink with a light meal in the evening before and 5-7 days after treatment with propranolol (20 mg three times daily). BP and heart rate (HR) were measured every 30 min for 24 h in each period. Blood sampling and echocardiographic examination were carried out before (17.00 h) and after (19.00 h) intake of alcohol or control drink, Before treatment, alcohol ingestion caused significant decreases in BP, total peripheral resistance and serum potassium concentration, while it increased heart rate (HR), cardiac output (CO), plasma norepinephrine and plasma renin activity (PRA). Treatment with propranolol significantly decreased BP and HR for 24 h. Propranolol and alcohol showed an additive depressor effect on night-time BP, and the alcohol-induced hypotension was similar before and after propranolol treatment. The alcohol-induced changes in HR, CO, PRA and serum potassium were significantly attenuated by propranolol. These results suggest that activation of the sympathetic nervous system plays a role in alcohol-induced cardiac stimulation, renin release and hypokalemia through beta receptors. Moderate doses of beta-blockers may not modify alcohol-induced BP reduction in Oriental subjects with hypertension.

Adrenergic beta-Antagonists↗

PubMed1999

Retroperitoneal germ cell tumor treated by PVeBV chemotherapy: a case report.

The extragonadal germ cell tumor are uncommon neoplasms which account for only 1-5% of germ cell tumors, and its prognosis is poor. We report here the use of combination chemotherapy with cisplatin, etoposide, bleomycin, and vinblastine (PVeBV) for the treatment of retroperitoneal germ cell tumor. A 28-year-old male with complaints of abdominal pain and lumbago, without any abnormality in both testes by physical and ultrasonographic examination, showed retroperitoneal tumor by abdominal computed tomography. The serum alpha-fetoprotein and lactate dehydrogenase were elevated. The retroperitoneal tumor was treated surgically. The pathological diagnosis was mixed germ cell tumor. The lung and supraclavicular lymph node metastases disappeared completely after 3 courses of PVeBV chemotherapy with cisplatin (40 mg/m2 per day) and etoposide (100 mg/m2 per day) for 5 consecutive days, with vinblastine (0.2 mg/kg) on day 1, and bleomycin (30 mg/body) given on days 1, 8, and 15. Granulocyte colony-stimulating factor and serotonin receptor antagonist application were available on acute phase toxic effects. The patient is now alive and well, without recurrence, more than 26 months after the operation.

Adult↗

PubMed1999

Metachronous bile duct cancer in a patient surviving for a decade and undergoing curative surgery twice.

We report a 75-year-old woman with metachronous bile duct cancer who underwent curative resection twice and has survived for a decade. In 1989, she was admitted because her serum alkaline phosphatase level was elevated. Computed tomography (CT) showed a low-density mass, 2 cm in diameter, at the left hepatic duct and intrahepatic bile duct dilatation in the left lobe. We diagnosed the lesion as an intrahepatic bile duct cancer and performed extended left hepatic lobectomy with systematic lymph node dissection. The histological diagnosis was a well differentiated cholangiocellular carcinoma with hepatic hilar and celiac lymph node metastases (T1N2M0, Stage IVB). In 1996, she was re-admitted with obstructive jaundice. CT showed a slightly enhanced mass, 4 cm in diameter, in the pancreatic head. After reducing the jaundice by percutaneous transhepatic biliary drainage, pancreatoduodenectomy was performed. The histological diagnosis of this lesion was a moderately differentiated adenocarcinoma originating from the intrapancreatic bile duct. Ten years after the first operation, she is leading a normal daily life with no cancer recurrence. These findings suggest that repeated curative surgery can result in a long-term survival of patients with metachronous bile duct cancer.

Adenocarcinoma↗

PubMed1999

Synthesis of novel nucleotide analogues possessing a difluoromethylenephosphonato group. Evaluation of the inhibitory activity for purine nucleoside phosphorylase.

Novel nucleotide analogues 1-6 were prepared as "multi-substrate" analogue inhibitors for purine nucleoside phosphorylases (PNPs). The cyclopropane and the tetrahydrofuran moieties of the alkyl spacer connecting a nucleobase and difluoromethylene phosphonic acid were found to be effective for good inhibition of PNPs.

Actinomycetales↗

PubMed1999

DNA analysis by microfabricated capillary electrophoresis device.

The LIGA (Lithographie Galvanoformung Abformung) process using synchrotron radiation lithography is applied to the microfabrication of capillary array electrophoresis (CAE) device. Laser-induced fluorescence detection system for the CAE device has been constructed by the modification of laser confocal fluorescence microscopy. DNA molecules were detected during migrating in the microchannels filled with polymer separation matrices under electric field to optimize the separation conditions for DNA analysis. Based on this observation, we demonstrated that microfabricated CAE device is realized the fast separation of DNA.

DNA↗

PubMed1999

Roles of the functional loss of p53 and other genes in astrocytoma tumorigenesis and progression.

Loss of function of the p53 tumor suppressor gene due to mutation occurs early in astrocytoma tumorigenesis in about 30-40% of cases. This is believed to confer a growth advantage to the cells, allowing them to clonally expand due to loss of the p53-controlled G1 checkpoint and apoptosis. Genetic instability due to the impaired ability of p53 to mediate DNA damage repair further facilitates the acquisition of new genetic abnormalities, leading to malignant progression of an astrocytoma into anaplastic astrocytoma. This is reflected by a high rate of p53 mutation (60-70%) in anaplastic astrocytomas. The cell cycle control gets further compromised in astrocytoma by alterations in one of the G1/S transition control genes, either loss of the p16/CDKN2 or RB genes or amplification of the cyclin D gene. The final progression process leading to glioblastoma multiforme seems to need additional genetic abnormalities in the long arm of chromosome 10; one of which is deletion and/or functional loss of the PTEN/MMAC1 gene. Glioblastomas also occur as primary (de novo) lesions in patients of older age, without p53 gene loss but with amplification of the epidermal growth factor receptor (EGFR) genes. In contrast to the secondary glioblastomas that evolve from astrocytoma cells with p53 mutations in younger patients, primary glioblastomas seem to be resistant to radiation therapy and thus show a poorer prognosis. The evaluation and design of therapeutic modalities aimed at preventing malignant progression of astrocytomas and glioblastomas should now be based on stratifying patients with astrocytic tumors according to their genetic diagnosis.

Alleles↗

PubMed1999

Genealogy of families of SINEs in cetaceans and artiodactyls: the presence of a huge superfamily of tRNA(Glu)-derived families of SINEs.

Several novel (sub)families of SINEs were isolated from the genomes of cetaceans and artiodactyls, and their sequences were determined. From comparisons of diagnostic nucleotides among the short interspersed repetitive elements (SINEs) in these (sub)families, we were able to draw the following conclusions. (1) After the divergence of the suborder Tylopoda (camels), the CHRS family of SINEs was newly created from tRNA(Glu) in a common ancestor of the lineages of the Suina (pigs and peccaries), Ruminantia (cows and deer), and Cetacea (whales and dolphins). (2) After divergence of the Suina lineage, the CHR-1 SINE and the CHR-2 SINE were generated successively in a common ancestor of ruminants, hippopotamuses, and cetaceans. (3) In the Ruminantia lineage, the Bov-tA SINE was generated by recombination between the CHR-2 SINE and Bov-A. (4) In the Suina lineage, the CHRS-S SINE was generated from the CHRS SINE. (5) In this latter lineage, the PRE-1 family of SINEs was created by insertion of part of the gene for tRNA(Arg) into the 5' region of the CHRS-S family. The distribution of a particular family of SINEs among species of artiodactyls and cetaceans confirmed the most recent conclusion for paraphyly of the order Artiodactyla. The present study also revealed that a newly created tRNA(Glu)-derived family of SINEs was subjected both to recombination with different units and to duplication of an internal sequence within a SINE unit to generate, during evolution, a huge superfamily of tRNA(Glu)-related families of SINEs that are now found in the genomes of artiodactyls and cetaceans.

Animals↗

PubMed1999

Analysis of optical signals evoked by peripheral nerve stimulation in rat somatosensory cortex: dynamic changes in hemoglobin concentration and oxygenation.

The origins of reflected light changes associated with neuronal activity (optical signals) were investigated in rat somatosensory cortex with optical imaging, microspectrophotometry, and laser-Doppler flowmetry, and dynamic changes in local hemoglobin concentration and oxygenation were focused on. Functional activation was carried out by 2-second, 5-Hz electrical stimulation of the hind limb under chloralose anesthesia. These measurements were performed at the contralateral parietal cortex through a thinned skull. Regional cortical blood flow (rCBF) started to rise 1.5 seconds after the stimulus onset, peaked at 3.5 seconds (26.7% +/- 9.7% increase over baseline), and returned to near baseline by 10 seconds. Optical signal responses at 577, 586, and 805 nm showed a monophasic increase in absorbance coincident with the increase in rCBF; however, the signal responses at 605 and 760 nm were biphasic (an early increase and late decrease in absorbance) and microanatomically heterogeneous. The spectral changes of absorbance indicated that the concentrations of both total hemoglobin and oxyhemoglobin increased together with rCBF; deoxyhemoglobin, increased slightly but distinctly (P = 0.016 at 1.0 seconds, P = 0.00038 at 1.5 seconds) just before rCBF increases, then decreased. The authors conclude that activity-related optical signals are greatly associated with a moment-to-moment adjustment of rCBF and metabolism to neuronal activity.

Animals↗

PubMed1999

Anterior approach to intramedullary hemangioblastoma: case report.

OBJECTIVE AND IMPORTANCE: Intramedullary spinal cord tumors are generally operated on by using the posterior approach. However, the posterior approach may not be suitable for a tumor in the anterior part of the spinal cord. In this report, we describe a case of a cervical intramedullary tumor that was successfully removed by using the anterior approach. CLINICAL PRESENTATION: A 48-year-old woman presented with lower cranial nerve disturbance and motor weakness of the upper extremities. Magnetic resonance imaging revealed a large extensive syrinx and an intramedullary enhanced tumor at the C6 level. The tumor was located at the left of the anterior part of the spinal cord. INTERVENTION: Based on these findings, the anterior approach was used in performing a corpectomy of C5 and C6. The tumor was highly vascular and was resected without resulting in any operative deficits. The pathological diagnosis was hemangioblastoma. CONCLUSION: The present case suggests that the anterior approach is an important option among surgical approaches to the intramedullary tumor in cases in which the tumors are small in size and are located in the anterior part of the cervical cord.

Cervical Vertebrae↗

PubMed1999

Human T-cell leukemia virus type 1 can infect a wide variety of cells in mice.

Analysis of human T-cell leukemia virus type 1 (HTLV-1)-infected cell types and the interplay of these infected cells in vivo should provide valuable information to elucidate the pathogenesis of HTLV-1-associated diseases in humans and in animal models. In this study, HTLV-1-infected cell types were identified in HTLV-1-infected C3H/HeJ mice. Pan T, CD4+, CD8+, granulocyte and pan B cell fractions in the splenocytes of MT-2 cell-inoculated mice were sorted by use of their cell surface high-density expression of CD3e, CD4, CD8, Gr-1 and B220 antigens, respectively, with a fluorescence-activated cell sorter. The pX sequence of HTLV-1 provirus in the lysate of each fraction was amplified by polymerase chain reaction and detected by Southern hybridization. Interestingly, in addition to the CD4+ cell fraction, the pX sequence was also found in CD8+ cell, B cell and granulocyte fractions. The broad cell spectrum of HTLV-1 infection in mice is consistent with the situation in humans. Our finding indicate that HTLV-1 receptor or coreceptor is widely distributed among different cell types in mice.

Animals↗

PubMed1999

Treatment of advanced atrioventricular block with beta-adrenergic blockade therapy.

A 26-year old woman, who experienced syncope associated with advanced AV block, was referred for further evaluation. Electrophysiological study showed normal SA and AV node physiology. Syncope associated with advanced AV block on the electrocardiogram was induced by head-up tilt test. Oral propranolol therapy completely prevented the AV block and syncope induced by head-up tilt. The physician should be aware of advanced AV block associated with neurocardiogenic syncope, especially before permanent - pacemaker therapy is considered. The head-up tilt test is a useful diagnostic tool for an etiology of paroxysmal AV block.

Adrenergic beta-Antagonists↗

PubMed1999

Possible involvement of hypothyroidism as a cause of lithium-induced sinus node dysfunction.

Although several reports have stated that even therapeutic levels of lithium can induce sinus node dysfunction, the mechanism has not been fully elucidated. We present here two patients with sinus node dysfunction after long-term lithium therapy. Following lithium discontinuation, sinus node function recovered completely. After resuming lithium, however, irreversible sinus node dysfunction recurred and a permanent pacemaker was implanted in one patient. The serum concentration of lithium was within therapeutic levels. Nevertheless, hypothyroidism was associated with the sinus node dysfunction in both patients. Thus, thyroid function may play an important role in sinus node dysfunction induced by lithium.

Adult↗

PubMed1999

A rare combination consisting of primary hyperaldosteronism and glucagonoma.

A 59-yr-old man with multiple pancreatic tumors is presented. Previously, he had undergone left adrenalectomy for primary hyperaldosteronism and left nephrectomy for renal cell carcinoma at the ages of 39 and 55 yr, respectively. This time, 3 yr after removal of renal cancer, two solid lesions in the pancreas associated with hyperglucagonemia were detected. Under a diagnosis of pancreatic metastasis from renal cell carcinoma or islet cell tumor of the pancreas, distal pancreatectomy with splenectomy and enucleation of the tumor in the pancreas head were performed. Microscopically, a glucagonoma, measuring 2.3 mm in diameter, was detected among five pancreatic metastases from renal cell carcinoma. Four years after surgery, the patient remains well, without signs of recurrence despite multiple pancreatic metastases. This is the first report of such a rare combination consisting of aldosterone-secreting adrenal adenoma and glucagonoma.

Adrenal Cortex Neoplasms↗

PubMed1999

Genetic and epigenetic control of the proliferation and differentiation of mouse epidermal melanocytes in culture.

Serum-free culture of epidermal cell suspensions from neonatal skin of mice of strain C57BL/10JHir (B10) showed that alpha-melanocyte-stimulating hormone (alpha-MSH) was involved in regulating the differentiation of melanocytes by inducing tyrosinase activity, melanosome formation, and dendritogenesis. Dibutyryl adenosine 3':5'-cyclic monophosphate (DBcAMP) similarly induced the differentiation of melanocytes. On the other hand, DBcAMP induced the proliferation of epidermal melanocytes in culture in the presence of keratinocytes. Basic fibroblast growth factor (bFGF) was also shown to stimulate the sustained proliferation of undifferentiated melanoblasts in the presence of DBcAMP and keratinocytes. These results suggest that the proliferation and differentiation of mouse epidermal melanoblasts and melanocytes in culture are regulated by the three factors; namely, cAMP, bFGF, and keratinocyte-derived factors. Moreover, serum-free primary culture of mouse epidermal melanocytes derived from B10 congenic mice, which carry various coat color genes, showed that the coat color genes were involved in regulating the proliferation and differentiation of mouse epidermal melanocytes by controlling the proliferative rate, melanosome formation and maturation, and melanosome distribution.

Animals↗

PubMed1999

Poly(aspartic acid) degradation by a Sphingomonas sp. isolated from freshwater.

A poly(aspartic acid) degrading bacterium (strain KT-1 [JCM10459]) was isolated from river water and identified as a member of the genus Sphingomonas. The isolate degraded only poly(aspartic acid)s of low molecular masses (<5 kDa), while the cell extract hydrolyzed high-molecular-mass poly(aspartic acid)s of 5 to 150 kDa to yield aspartic acid monomer.

Alphaproteobacteria↗

PubMed1999

Measurement of retinal nerve fibre layer by scanning laser polarimetry and high pass resolution perimetry in normal tension glaucoma with relatively high or low intraocular pressure.

AIMS: To determine whether any differences may exist in the relation between the neural capacity as determined by high pass resolution perimetry and the thickness of the retinal nerve fibre layer (RNFL) in patients having normal tension glaucoma (NTG) with a relatively high intraocular pressure (IOP) between 16 and 21 mm Hg (HNTG) v those with a lower IOP below 15 mm Hg (LNTG). METHODS: Scanning laser polarimetry and high pass resolution perimetry were performed in 20 eyes of 20 patients with HNTG and 21 eyes of 21 patients with LNTG. The correlation between total and regional thickness of the peripapillary RNFL and the corresponding total and regional neural capacity with linear regression analysis were evaluated. RESULTS: Overall, although the total RNFL thickness was not significantly correlated with the total neural capacity, the RNFL thickness in each of the superior and inferior quadrants was significantly correlated with the corresponding regional neural capacity (r = 0.44, p = 0.0045; r = 0.39, p = 0.0126 for each). The RNFL thickness in each of the superior and inferior quadrants in the HNTG group was significantly correlated with the corresponding regional neural capacity (r = 0.52, p = 0.0196; r = 0.49, p = 0.0286 for each). No significant correlation between neural capacity and the RNFL thickness was observed either globally or regionally in the LNTG group. CONCLUSION: The degree of the correlation between neural capacity as determined by high pass resolution perimetry and thickness of the RNFL as measured by scanning laser polarimetry appeared to differ in NTG patients with an IOP higher than 15 mm Hg v those with a lower IOP.

Adult↗