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H Abe

Publications and source records attributed to H Abe.

At least 415 records · Page 23Linked to original sources
PubMed1997

Molecular evidence from retroposons that whales form a clade within even-toed ungulates.

The origin of whales and their transition from terrestrial life to a fully aquatic existence has been studied in depth. Palaeontological, morphological and molecular studies suggest that the order Cetacea (whales, dolphins and porpoises) is more closely related to the order Artiodactyla (even-toed ungulates, including cows, camels and pigs) than to other ungulate orders. The traditional view that the order Artiodactyla is monophyletic has been challenged by molecular analyses of variations in mitochondrial and nuclear DNA. We have characterized two families of short interspersed elements (SINEs) that were present exclusively in the genomes of whales, ruminants and hippopotamuses, but not in those of camels and pigs. We made an extensive survey of retropositional events that might have occurred during the divergence of whales and even-toed ungulates. We have characterized nine retropositional events of a SINE unit, each of which provides phylogenetic resolution of the relationships among whales, ruminants, hippopotamuses and pigs. Our data provide evidence that whales, ruminants and hippopotamuses form a monophyletic group.

Animals↗
PubMed1997

Leptin induces mitogen-activated protein kinase-dependent proliferation of C3H10T1/2 cells.

Leptin, secreted by adipocytes, regulates satiety and energy expenditure. Several forms of leptin receptors produced by alternative mRNA splicing are found in many tissues, including the hypothalamus, liver, lung, kidney, hematopoietic cells, and gonads, suggesting that leptin exerts effects in these tissues. In accordance with the distribution of leptin receptors, there is accumulating evidence that leptin plays various roles in reproduction, hematopoiesis, and the immune systems in addition to the regulation of food intake and energy expenditure. In the present study, we examined the in vitro effects of leptin on proliferation of a mouse embryonic cell line, C3H10T1/2, and its mechanism of action. Leptin caused a dose- and time-dependent increase in mitogen-activated protein kinase (MAPK) activity that was accompanied by an increase in C3H10T1/2 cell number. The MAPK kinase-1-specific inhibitor PD98059 completely blocked the increases in both MAPK activity and cell proliferation caused by leptin. These findings indicate that leptin stimulates the proliferation of C3H10T1/2 cells via the MAPK cascade.

Animals↗
PubMed1997

Xenopus actin depolymerizing factor/cofilin (XAC) is responsible for the turnover of actin filaments in Listeria monocytogenes tails.

In contrast to the slow rate of depolymerization of pure actin in vitro, populations of actin filaments in vivo turn over rapidly. Therefore, the rate of actin depolymerization must be accelerated by one or more factors in the cell. Since the actin dynamics in Listeria monocytogenes tails bear many similarities to those in the lamellipodia of moving cells, we have used Listeria as a model system to isolate factors required for regulating the rapid actin filament turnover involved in cell migration. Using a cell-free Xenopus egg extract system to reproduce the Listeria movement seen in a cell, we depleted candidate depolymerizing proteins and analyzed the effect that their removal had on the morphology of Listeria tails. Immunodepletion of Xenopus actin depolymerizing factor (ADF)/cofilin (XAC) from Xenopus egg extracts resulted in Listeria tails that were approximately five times longer than the tails from undepleted extracts. Depletion of XAC did not affect the tail assembly rate, suggesting that the increased tail length was caused by an inhibition of actin filament depolymerization. Immunodepletion of Xenopus gelsolin had no effect on either tail length or assembly rate. Addition of recombinant wild-type XAC or chick ADF protein to XAC-depleted extracts restored the tail length to that of control extracts, while addition of mutant ADF S3E that mimics the phosphorylated, inactive form of ADF did not reduce the tail length. Addition of excess wild-type XAC to Xenopus egg extracts reduced the length of Listeria tails to a limited extent. These observations show that XAC but not gelsolin is essential for depolymerizing actin filaments that rapidly turn over in Xenopus extracts. We also show that while the depolymerizing activities of XAC and Xenopus extract are effective at depolymerizing normal filaments containing ADP, they are unable to completely depolymerize actin filaments containing AMPPNP, a slowly hydrolyzible ATP analog. This observation suggests that the substrate for XAC is the ADP-bound subunit of actin and that the lifetime of a filament is controlled by its nucleotide content.

Actin Cytoskeleton↗
PubMed1997

Analysis of long-term treatment of intracranial germinoma.

PURPOSE: To determine an appropriate treatment policy for intracranial germinoma. METHODS AND MATERIALS: From 1976 to 1992, 51 patients with germinoma (18 with pathologically verified germinoma and 33 diagnosed as having germinoma by neuroimagings) were treated by radiation therapy. Various radiation doses and treatment fields were used. RESULTS: The 10-year cause-specific survival rate for pathologically verified and unverified germinoma was 100% and 96%, respectively. Relapses were noted in four patients, three of whom died from the disease. Two of the four patients with a tumor larger than 4 cm in gross diameter experienced relapse. Two relapses occurred in a nonirradiated spinal canal and two occurred in the irradiation area treated by 25 Gy in 10 fractions and 30 Gy in 20 fractions. No relapse was noted in patients in whom the whole ventricle field was determined precisely using three-dimensional treatment planning. Five patients who were followed at an outpatient clinic experienced significant late neurocognitive dysfunction, which set in after radiotherapy. CONCLUSION: After pathological confirmation, 40 Gy whole-ventricle irradiation using precise three-dimensional treatment planning is appropriate as a standard treatment for most intracranial germinoma.

Adolescent↗
PubMed1997

Stereotactic irradiation without whole-brain irradiation for single brain metastasis.

PURPOSE: The effectiveness of stereotactic irradiation (STI) alone without whole-brain irradiation (WBI) for a single metastatic brain tumor was analyzed retrospectively. METHODS AND MATERIALS: Forty-four patients with this condition were treated using radiosurgery (RS) alone or fractionated stereotactic radiotherapy (FSR) without WBI. RESULTS: The initial response rate was 92% and the overall local control rate was 84% (37 of 44 patients). A total of 39% (18 of 44) of patients experienced intracranial relapse outside the initial target area. Forty-eight percent (21 of 44) of patients required salvage treatment for intracranial relapse. All 7 patients who received WBI as salvage treatment required no further salvage treatment, but 5 of the 14 patients who received salvage STI without WBI required three to four treatments for brain metastasis. Late radiation damage was not seen with initial treatment but was observed with retreatment. The overall median survival time was 261 days, with a standard error of 64 days. Actuarial survival at 12 and 24 months was 34% and 9%, respectively. The actuarial survival rate was significantly affected by the existence of active extracranial disease (p = 0.041). CONCLUSION: The high response rate and short treatment period of STI alone are advantageous in the treatment of single brain metastasis in patients with active extracranial disease with WBI reserved for relapse. Because of the low complication rate, STI alone may be also useful in patients with good prognosis, without extracranial disease.

Aged↗
PubMed1997

Up-regulation of glial fibrillary acidic protein in the retina of primate eyes with experimental glaucoma.

OBJECTIVE: To identify molecular mechanisms of retinal responses to intraocular pressure elevation in primate experimental glaucoma. METHODS: An experimental glaucoma model was created by repeated laser trabeculophotocoagulation. After the preparation of complementary DNAs from extracted total RNAs in the retinas, polymerase chain reaction (PCR) experiments were performed for the following screening target genes: beta-tubulin beta 2 and beta 5 and glial fibrillary acidic protein (GFAP). To investigate the amplified sequences derived from the PCR experiments, sequencing, subcloning, and Southern blot analysis of PCR products were performed. In addition, an immunohistochemical analysis was performed in an attempt to show the distribution of the target gene products in the retinas. RESULTS: A series of PCR experiments suggested up-regulation of gene expression for GFAP but not for beta-tubulins. Sequencing of the PCR products and results of the Southern blot analysis showed that the amplified sequences were derived mainly from the target gene, GFAP, and that increased expression of GFAP was found despite the severity of glaucoma. Immunohistochemical studies also demonstrated increased expression of GFAP proteins in Müller cells and astrocytes in the retinas of primate eyes with experimental glaucoma. CONCLUSIONS: Our study showed up-regulation of GFAP at gene and protein levels, which suggests that glial components in the retina may contribute to the pathologic processes induced by elevated intraocular pressure.

Animals↗
PubMed1997

Effects of mitomycin C on the expression of proliferating cell nuclear antigen after filtering surgery in rabbits.

BACKGROUND: The aim of the study was to evaluate the effects of mitomycin C on the cell replication activity in wound healing following experimental filtration surgery. METHODS: Trabeculectomy with or without application of mitomycin C was performed on albino rabbit eyes. At 1, 4, 7, 14, and 28 days after surgery, the expression of proliferating cell nuclear antigen, a marker of cell proliferation, in the filtering site was examined immunohistochemically using a streptavidin-biotin complex method. RESULTS: In control eyes that underwent trabeculectomy but did not receive mitomycin C, the number of immunoreactive cells increased 4-7 days after operation and decreased markedly at around 14 days. The filtering site was obstructed histologically at 4-7 days after operation. In the mitomycin C-treated eyes, immunoreactive cells appeared 4 days after surgery but disappeared by 7 days at the surgical site. The number of immunoreactive cells in the treated eyes was much lower than that in control eyes. CONCLUSION: The cell replication activity was markedly inhibited by administration of mitomycin C. The filtering site remained open for 28 days after surgery, whereas it was completely obstructed within 7 days in control eyes. Immunocytochemistry for proliferating cell nuclear antigen, as used in this study, is a simple and reliable method for detection of cell replication activity.

Animals↗
PubMed1997

Osteoregenerative lateral suboccipital craniectomy using fibrin glue.

This report describes a simple technique of cranioplasty for suboccipital craniectomy and the results of a clinical study to assess the effects of fibrin glue on regeneration of the skull. Cranioplasty using a mixture of autologous bone chips and human allogenic fibrin glue was performed in 31 patients who received lateral suboccipital craniectomy. Long-term observations with three-dimensional CT showed satisfactory reconstruction of the mastoid-occipital bone plate in 25 patients (81%); among them, a nearly complete reconstruction of the occipital bone (plate) was found in 14 patients. Regeneration of the bone began 6 months after surgery on the inner surface, adjacent to the dura mater. In conclusion, the present technique provides a new simple method to restore an autologous bone plate in a cranial defect made by piecemeal craniectomy.

Adolescent↗
PubMed1997

Benign cervical teratoma in an adult: report of a case.

Cervical teratomas are rarely encountered in adults. We report herein the case of a 21-year-old woman who was admitted to our hospital for surgical treatment of a neck tumor, 7.5 x 4.5 x 2.7 cm in size, located in the left lower pole of the thyroid. Ultrasonography (US) and computed tomography (CT) revealed a multicystic tumor. The levels of carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and squamous cell carcinoma-related antigen (SCC) in the cystic fluid were extremely elevated in contrast to the normal levels found in the serum. The tumor was completely excised and histological examination revealed it to be composed of elements derived from the three germ layers, confirming a diagnosis of benign cystic teratoma.

Adult↗
PubMed1997

Metabolic and neurological patterns in chronic cerebral infarction: a single-voxel 1H-MR spectroscopy study.

The details of brain metabolism in chronic cerebral infarcts have not been clarified. Using proton MR spectroscopy (1H-MRS) at 1.5 T, we measured biochemical changes in 16 patients with large infarcts involving the motor cortex in the chronic phase (median 293.9 days) and related the findings to clinical data. Localised spectra were obtained using point-resolved spectroscopy, with an echo time of 270 ms. Regions of interest were placed on the frontal lobe, including the precentral gyrus and central sulcus. Motor function was assessed by the manual muscle power test at the time of the 1H-MRS study. Only three patients with severe paresis had no signal in the lesions and a lactate signal was obtained in 13 cases. N-acetyl aspartate (NAA) was observed in 4 cases with recanalisation of an occluded vessel. Motor function correlated strongly with the NAA/choline-containing compounds (Cho) ratio (P < 0.01) and lactate/Cho ratio (P < 0.01). We found various metabolic patterns, reflecting residual neurological function.

Adult↗
PubMed1997

Molecular mass of poly[(R)-3-hydroxybutyric acid] produced in a recombinant Escherichia coli.

Poly[(R)-3-hydroxybutyric acid] (PHB) was produced at 37 degrees C by a recombinant Escherichia coli harboring the Alcaligenes eutrophus biosynthesis phb-CAB genes in Luria-Bertani media containing glucose at 10-30 g/l at different pH values and the time-dependent changes in the molecular mass of PHB were studied. PHB polymers accumulated within cells while glucose was present in the medium. The number-average molecular mass of PHB decreased with time during the course of PHB accumulation, and the values for PHB were markedly dependent on the cultivation conditions of the E. coli, ranging from 0.5 MDa to 20 MDa. Under specific conditions (pH 6.0), E. coli produced PHB with an extremely high molecular mass (20 MDa). It has been suggested that a chain-transfer agent is generated in E. coli cells during the accumulation of PHB.

Acyltransferases↗
PubMed1997

Impact of intraoperative ultrasonography on surgery for cystic lesions of the pancreas.

The impact of intraoperative ultrasonography (IUS) on surgery for cystic lesions of the pancreas (CLPs) has not been fully clarified. Twenty patients with CLPs, including 5 pseudocysts and 15 true cysts, were scanned intraoperatively to evaluate the utility and practicality of IUS for CLPs. In four of the five patients with pseudocysts and two with retention cysts, the operative procedures were performed under IUS guidance. In one with a pseudocyst, IUS showed that the cyst did not involve the pancreas, and subsequently cystectomy without pancreatic resection was necessary. In one of the two patients with mucin-producing cystadenocarcinomas, IUS demonstrated a skip lesion in the duct of the pancreatic tail, which contributed to changing the operative procedure from pancreatoduodenectomy to total pancreatectomy; in the other, IUS showed that the lesion was localized in the body of the pancreas, and subsequently segmental pancreatectomy was carried out instead of scheduled pancreatoduodenectomy or distal pancreatectomy. Thus in these three patients the operative procedures were changed in light of the IUS findings. In the remaining 11, although IUS visualized CLPs clearly, it added no new information relevant to the operations. We conclude that IUS contributes to performing surgery for certain types of CLP, such as pseudocysts with severe inflammation, retention cysts with nonpalpable or invisible small cysts, mucin-producing cystadenocarcinomas, and possibly other lesions.

Cystadenocarcinoma, Mucinous↗
PubMed1997

Combined revascularization surgery for childhood moyamoya disease: STA-MCA and encephalo-duro-arterio-myo-synangiosis.

We present surgical techniques for optimal revascularization in childhood moyamoya disease. During the past 10 years we performed revascularization surgery for childhood moyamoya disease using direct revascularization with superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and indirect revascularization of encephalo-duro-arterio-myo-synangiosis (EDAMS) 43 times. Points of this surgery are as follows: (1) craniotomy and dural opening for the most extensive possible exposure of the brain surface, (2) protective manipulation of the STA, temporal muscle and middle meningeal artery, (3) STA-MCA anastomosis to the frontal branch of the MCA to improve cerebral circulation of the frontal lobe using a small branch of the STA, and (4) a small opening in the arachnoid membrane and watertight closure.

Brain Ischemia↗
PubMed1997

Surgical treatment of syringomyelia associated with spinal dysraphism.

Clinical and radiological features of syringomyelia in 15 patients with spinal dysraphism are reported. There were 8 patients with occult spinal dysraphism (lumbosacral lipoma) and 7 with spina bifida aperta (meningomyelocele). Syringomyelia with spinal dysraphism can be radiologically divided into two types according to the dysraphic state. The syrinx in the patients with occult spinal dysraphism occurred immediately rostral to the lipoma and was localized to the lower thoracic to lumbar levels, while in the meningomyelocele patients the syrinx extended from the cervical to the thoracic level. Large syrinx formation was recognized in 1 of the 7 occult spinal dysraphism cases and 3 of the 8 meningomyelocele cases. For syringomyelia with occult spinal dysraphism, 4 patients underwent syringo-subarachnoid shunting (S-S shunt, 2 cases) or syringostomy (2 cases) during an untethering operation. In the case of meningomyelocele, S-S shunts were placed in 2 patients. Collapse of the syrinx was achieved in all 6 patients who underwent S-S shunting or syringostomy. Decreased size of the syrinx was also noted in 3 occult spinal dysraphism patients who underwent untethering operations alone. In conclusion, a large syrinx in the case of spinal dysraphism should be surgically treated. S-S shunting is effective in both types of syringomyelia. Foramen magnum decompression may be an alternative method of surgical treatment for syringomyelia in patients with meningomyelocele.

Child↗
PubMed1997

Surgical treatment supposed natural history of the tethered cord with occult spinal dysraphism.

We retrospectively evaluated the pre- and postoperative course of 34 tethered cord patients with occult spinal dysraphism in an attempt to infer the natural history of this disorder and to determine the effectiveness of the surgical treatment. There were 32 cases with lumbosacral lipoma and 2 with tight filum terminale. The age at surgery ranged from 1 month to 47 years old. Eight patients, aged 1 month to 4 years old, were asymptomatic; 26 had neurogenic bladder (26 cases) or motor problems affecting the legs (8 cases). None of the patients older than 5 years of age were asymptomatic. Untethering of the spinal cord was performed in all cases. The postoperative follow-up period ranged from 5 months to 11 years. During these periods, 7 (88%) of the 8 asymptomatic patients remained neurologically intact, 6 (23%) of the 26 symptomatic patients showed improved symptoms, and 15 patients (58%) remained unchanged. These results indicate that the neurological symptoms will appear progressively in the tethered cord patients, and that prophylactic surgery should be considered as early as possible.

Adolescent↗