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Biomedical subjects

M Maekawa

Publications and source records attributed to M Maekawa.

At least 73 records · Page 4Linked to original sources
PubMed1999

Song-induced phosphorylation of cAMP response element-binding protein in the songbird brain.

We have investigated the participation of cAMP response element-binding protein (CREB) in the response of the songbird brain to a natural auditory stimulus, a conspecific song. The cells in the two song control nuclei, the higher vocal center (HVC) and area X of zebra finches (Taeniopygia guttata), were intensely stained with an anti-CREB monoclonal antibody. Double-labeling studies showed that CREB immunoreactivity was detected only in area X-projecting neurons in the HVC. The cloned CREB cDNA from zebra finches (zCREB) is highly homologous to mammalian delta CREB. Phosphorylation of zCREB at Ser119 in area X-projecting HVC neurons was induced by hearing tape-recorded conspecific songs of zebra finches, but not by birdsongs of another species or white noise. These results raise the possibility that zCREB plays a crucial role in the sensory process of song learning.

Amino Acid Sequence↗
PubMed1999

Analysis of synovial fluid components of hydrarthrosis in long-term hemodialysis patients.

The synovial fluid components in long-term hemodialysis patients (HD; 43 knees in 43 patients) were investigated and compared with those in patients with osteoarthritis (OA; 21 knees in 21 patients) and rheumatoid arthritis (RA; 26 knees in 26 patients). The average ages in the three groups were, respectively, 60.7 years (range, 34-79 years), 63.2 years (range, 48-88 years), and 59.7 years (range, 37-76 years). The duration of hemodialysis in the HD group averaged 14.0 years (range, 4-24 years). The concentrations of hyaluronic acid, protein, and isomers of chondroitin sulfate (chondroitin 6-sulfate [C6S] and chondroitin 4-sulfate [C4S]) in the synovial fluid, and its viscosity were measured. Differences in each of the parameters were investigated according to disease clinical stage, roentgenological grade, and periods of dialysis in the HD group. The viscosity of the synovial fluid and the concentration of hyaluronic acid in HD patients were similar to those in OA patients; however, the C6S/C4S ratio in the synovial fluid of HD patients was similar to that in RA patients. The latter finding suggests that synovitis may be present in the hydrarthrosis of HD patients. The cause of this synovitis in HD patients remains to be elucidated.

Adult↗
PubMed1999

A novel in-frame deletion mutation in a case of lactate dehydrogenase (LD) H subunit deficiency showing an atypical LD isoenzyme pattern in serum and erythrocytes.

OBJECTIVE: We report a case showing an atypical lactate dehydrogenase (LD) isoenzyme pattern involving deficiency only of LD-1 and LD-2 in serum and erythrocytes. LD activity in serum from this patient was extremely low, similar to complete LD-H deficiency, and also that in erythrocytes was low. DESIGN: The DNA fragment containing exon 1 through 7 of the LD-H gene were amplified by PCR and directly sequenced. Total RNA was prepared from venous blood and the proportion of LD-H cDNA to total LD cDNA was semiquantified. RESULTS: Genetic analysis by DNA sequencing detected a three base deletion (AAT) at codon 220 of exon 5, which caused a deletion of one asparagine. The present case did not show reduced LD-H expression at the mRNA level in whole blood. Residue 220 is involved in turning beta-J to alpha1-G and is not buried in the interior of the protein. The novel homozygous in-frame deletion mutation at codon 220 may cause a three-dimensional change of the subunit-binding domain.

Adult↗
PubMed1999

Effects of T-588, a novel cognitive enhancer, on ADP-ribosylation of G(s alpha) by cholera toxin and cyclic AMP accumulation in rat cerebral cortex.

We investigated the effects of R(-)-1-(benzo[b]thiophen-5-yl)-2-[2-(N,N-diethylamino)ethoxy]ethan ol hydrochloride (T-588), a novel cognitive enhancer, on trimeric GTP-binding proteins (G proteins) and cyclic AMP accumulation in rat cerebral cortex. T-588 (0.1-1.0 mM) inhibited the ADP-ribosylation of alpha subunit of Gs in a concentration-dependent manner. Auto-ADP-ribosylation of CTX was not inhibited by T-588. The stimulatory effect of guanosine 5'-(3-O-thio)triphosphate (GTPgammaS) on CTX-catalyzed ADP-ribosylation was attenuated by adding T-588 in assay mixture. ADP-ribosylation of Gi/Go by pertussis toxin was slightly inhibited by T-588. Isoproterenol-stimulated cyclic AMP accumulation was inhibited by adding 3 mM T-588 to rat cerebral cortical slices. Next, we investigated the effects of isoproterenol and T-588 on GTPgammaS binding. Membranes were first incubated with or without isoproterenol and T-588 in the presence of 0.2mM GTPgammaS, then cholate extract preparations were prepared from the washed membranes. Interestingly, the [32P]ADP-ribosylation of G(s alpha) was enhanced not only by isoproterenol but also by T-588. Although the obtained results are apparently inconsistent, T-588 seems to interact with G proteins, specifically Gs.

Adenosine Diphosphate Ribose↗
PubMed1999

Histological characterization of defective spermatogenesis in mice lacking the basigin gene.

Basigin is a transmembrane protein belonging to the immunoglobulin superfamily. In the light of the fact that knockout mice lacking the basigin gene (Bsg) are azoospermic, the phenotype in the male reproductive system was extensively examined in this study. Spermatogenesis in Bsg (-/-) mice was found to be disrupted, and arrested at the metaphase of the first meiotic division. A few germ cells differentiated into young spermatids, but they were exfoliated. The lumens of the male reproductive system were filled with round degenerated cells. Using the TUNEL method and electron microscopy, some of the degenerated cells in the testis and epididymal head were shown to be apoptotic. Crystalloids of fine tubules and unusual ectoplasmic specializations were also observed in the Sertoli cells of Bsg (-/-) mice. These specializations displayed unusual 'circular' structures. Furthermore, unusual ectoplasmic specializations covering the spermatocytes rather than the mature spermatids were found. These structures were formed as a result of the lack of mature spermatids in the Bsg (-/-) testis. Results from analyses of azoospermia in the Bsg (-/-) mice suggest that basigin, through the interactions between germ cells and Sertoli cells, is an essential factor in the growth and/or survival of spermatids.

Animals↗
PubMed1999

Multiple cardiovascular risk factors in obstructive sleep apnea syndrome patients and an attempt at lifestyle modification using telemedicine-based education.

Severe obstructive sleep apnea syndrome (OSAS) is a typical 'lifestyle-related disease' characterized by a high incidence of cardiovascular risk factors, such as obesity, smoking, hypertriglyceridemia, and diabetes mellitus. Patients with OSAS tend to have eating disorders as a result of efforts to overcome the intolerable sleepiness. Treatment of OSAS should therefore aim to improve the lifestyle through encouraging weight reduction, physical activity increase, and tobacco avoidance, in addition to direct therapy such as continuous positive airway pressure for upper airway obstruction. The telemedicine system we developed was considered to be effective for providing home-based education on nutrition and exercise aimed at correcting multiple risk factors in OSAS patients

Adult↗
PubMed1999

Survey of Japanese physicians' attitudes towards the care of adult patients in persistent vegetative state.

OBJECTIVES: Ethical issues have recently been raised regarding the appropriate care of patients in persistent vegetative state (PVS) in Japan. The purpose of our study is to study the attitudes and beliefs of Japanese physicians who have experience caring for patients in PVS. DESIGN AND SETTING: A postal questionnaire was sent to all 317 representative members of the Japan Society of Apoplexy working at university hospitals or designated teaching hospitals by the Ministry of Health and Welfare. The questionnaire asked subjects what they would recommend for three hypothetical vignettes that varied with respect to a PVS patient's previous wishes and the wishes of the family. RESULTS: The response rate was 65%. In the case of a PVS patient who had no previous expressed wishes and no family, 3% of the respondents would withdraw artificial nutrition and hydration (ANH) when the patient did not require any other life-sustaining treatments, 4% would discontinue ANH, and 30% would withhold antibiotics when the patient developed pneumonia. Significantly more respondents (17%) would withdraw ANH in the case of a PVS patient whose previous wishes and family agreed that all life support be discontinued. Most respondents thought that a patient's written advance directives would influence their decisions. Forty per cent of the respondents would want to have ANH stopped and 31% would not want antibiotics administered if they were in PVS. CONCLUSIONS: Japanese physicians tend not to withdraw ANH from PVS patients. Patients' written advance directives, however, would affect their decisions.

Adult↗
PubMed1999

[Dibucaine number (DN) and fluoride number (FN) of L330 I mutant recombinant cholinesterase by use of various substrates].

Dibucaine number (DN) and fluoride number (FN) of the recombinant 330 I mutant ChE (r330 I) expressed in human kidney cells (293 cell) were compared with recombinant usual ChE (rUU), by several assay kits and substrates. All of them showed lower the values compared with rUU. However, the r330 I/rUU ratios about FN determined by several substrates were higher than that determined by propionyl thiocholoneiodide (PTCI), which was recommended by American Association for Clinical Chemistry. In conclusion, commercially available assay kits may not be suitable for the determination of L330 I.

Butyrylcholinesterase↗
PubMed1999

[Efficacy of three dimensional CT angiography (3D-CTA) for a first diagnosis of occlusive cerebrovascular disorders].

Patients with cerebrovascular disorders generally undergo computerized tomography (CT), even though magnetic resonance imaging (MRI) is available. We investigated the efficacy of three dimensional CT angiography (3D-CTA) for a first diagnosis of occlusive cerebrovascular disorders. Sixty-two patients, who were suspected of occlusive cerebrovascular disorder on the basis of neurological findings or initial plain CT findings, were reviewed. 3D-CTA was performed at the first medical examination. As a result, two patients were diagnosed with ICA (internal carotid artery) occlusion, nine with MCA (middle cerebral artery) occlusion, and one with BA (basilar artery) occlusion. All twelve patients underwent cerebral angiography immediately after those 3D-CTA in every case. Angiographical findings were the same as 3D-CTA. Interventional superselective thrombolytic therapy was performed in ten of the twelve patients, and recanalization resulted in four of them. 3D-CTA may also be able to determine whether the occlusive vessel is the chief cerebral artery or the perforating artery.

Adult↗
PubMed1999

[Cerebral blood flow (CBF) before and after cranioplasty performed during the chronic stage after decompressive craniectomy evaluated by xenon-enhanced computerized tomography (Xe-CT) CBF scanning].

Patients who undergo decompressive craniectomy for the purpose of prevention of cerebral herniation sometimes improve neurologically or increase activity of daily life after cranioplasty during the chronic stage. We studied the effect which cranioplasty at the chronic stage had on intracranial environment by means of xenon-enhanced computerized tomography (Xe-CT) CBF scanning. Eight patients underwent decompressive craniectomy at the acute stage and cranioplasty at the chronic stage was reviewed. Xe-CT CBF scanning was performed before and after cranioplasty. On the slice of the basal ganglia. CBF of the symptomatic hemisphere increased in five patients and CBF of the other hemisphere increased in three patients after cranioplasty. On the slice 20 mm above the basal ganglia, CBF of the symptomatic hemisphere increased in five patients and CBF of the other hemisphere increased in four patients after cranioplasty. Cranioplasty after decompressive craniectomy may increase CBF of not only the symptomatic hemisphere but also the other hemisphere.

Aged↗
PubMed1999

[Moyamoya disease with intraventricular hemorrhage due to rupture of lateral posterior choroidal artery aneurysm: case report].

Intracranial aneurysms associated with moyamoya disease are often reviewed. Aneurysms not around the circle of Willis but on the collateral vessels are rare. A 71-year-old woman presented with sudden onset of severe headache and vomiting. CT scan showed an intraventricular hemorrhage from bilateral lateral ventricle to fourth ventricle. Cerebral angiography showed the occlusion of the terminal portion of the bilateral internal carotid artery with moyamoya vessels and three aneurysms at the distal portion of the left lateral posterior choroidal artery. Clinical symptoms improved day by day, but 17 days later, due to rebleeding of the aneurysms the patient fell into coma. The day after rebleeding, endovascular embolization was performed using liquid particle, and the left lateral posterior choroidal artery and the aneurysm were occluded. Brain infarction with massive brain edema of the left cerebral hemisphere resulted in the patient's death. The management of the aneurysms in the basal ganglia and on the collateral vessels associated with moyamoya disease is controversial. We suggest positive intervention during the acute stage for the peripheral artery aneurysms taking endovascular embolization into consideration to prevent rupture or rebleeding.

Aged↗
PubMed1999

[High creatine kinase MB concentration and activity in patients with rhabdomyosarcoma].

A 14-year-old boy with rhabdomyosarcoma (RMS) of the left palm showed increased concentration and activity of creatine kinase (CK; EC 2.7.3.2) MB in his serum. CK isoenzyme analysis revealed no extra band. Other laboratory data including high lactate dehydrogenase (LD) isoenzyme 2, CK isoenzyme BB and MB, neuron specific enolase (NSE), and clinical findings did not support the diagnosis of myocardial infarction. The high activity and concentration of CK-MB in serum is possibly originated from the tumor. We could follow his time-course and analyze laboratory data of him and other 6 patients with RMS. We concluded that CK-MB, both concentration and activity, was the more sensitive marker of disease states of RMS than NSE and LD to follow up the patients with RMS.

Adolescent↗
PubMed1998

[Two cases of traumatic-diaphragmatic hernia].

We report two cases of traumatic-diaphragmatic hernia caused by blunt injury. In case 1, abdominal findings were discovered on the 2nd day after the patient fell on the bottom from a horse, and in case 2, an emergency laparotomy was carried out due to the respiratory dysfunction which appeared immediately after a labor injury. The diaphragmatic ruptures at the left side observed in both cases, were closed directly. The prolapsed organs which shifted into the thoracic cavity were the stomach and colon in case 1, and the spleen and the tail part of the pancreas in case 2. In both cases, the organs were easily repositioned into the abdominal cavity without a hernial sac, but a splenectomy had to be performed because of splenic lacerations. In case 2, right rib fractures and lacerations of the left adrenal gland with retroperitoneal hematoma were observed. In the case of thoraco-abdominal blunt injuries, it is important to perform an early diagnosis and to consider the possibility of diaphragmatic hernia.

Adult↗
PubMed1998

Molecular dissection of the Rho-associated protein kinase (p160ROCK)-regulated neurite remodeling in neuroblastoma N1E-115 cells.

A critical role for the small GTPase Rho and one of its targets, p160ROCK (a Rho-associated coiled coil-forming protein kinase), in neurite remodeling was examined in neuroblastoma N1E-115 cells. Using wild-type and a dominant-negative form of p160ROCK and a p160ROCK-specific inhibitor, Y-27632, we show here that p160ROCK activation is necessary and sufficient for the agonist-induced neurite retraction and cell rounding. The neurite retraction was accompanied by elevated phosphorylation of myosin light chain and the disassembly of the intermediate filaments and microtubules. Y-27632 blocked both neurite retraction and the elevation of myosin light chain phosphorylation in a similar concentration-dependent manner. On the other hand, suppression of p160ROCK activity by expression of a dominant-negative form of p160ROCK induced neurites in the presence of serum by inducing the reassembly of the intermediate filaments and microtubules. The neurite outgrowth by the p160ROCK inhibition was blocked by coexpression of dominant-negative forms of Cdc42 and Rac, indicating that p160ROCK constitutively and negatively regulates neurite formation at least in part by inhibiting activation of Cdc42 and Rac. The assembly of microtubules and intermediate filaments to form extended processes by inhibitors of the Rho-ROCK pathway was also observed in Swiss 3T3 cells. These results indicate that Rho/ROCK-dependent tonic inhibition of cell process extension is exerted via activation of the actomysin-based contractility, in conjunction with a suppression of assembly of intermediate filaments and microtubules in many cell types including, but not exclusive to, neuronal cells.

3T3 Cells↗
PubMed1998

Large quantity production with extreme convenience of human SDF-1alpha and SDF-1beta by a Sendai virus vector.

We describe a robust expression of human stromal cell-derived factor-1alpha (SDF-1alpha) and SDF-1beta, the members of CXC-chemokine family, with a novel vector system based upon Sendai virus, a non-segmented negative strand RNA virus. Recombinant SDF-1alpha and SDF-1beta were detected as a major protein species in culture supernatants, reached as high as 10 microg/ ml. This remarkable enrichment of the products allowed us to use even the crude supernatants as the source for biological and antiviral assays without further concentration nor purification and will thus greatly facilitate to screen their genetically engineered derivatives.

Anti-HIV Agents↗