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Biomedical subjects

H Imai

Publications and source records attributed to H Imai.

At least 379 records · Page 21Linked to original sources
PubMed1991

Human autoantibody to RNA polymerase I transcription factor hUBF. Molecular identity of nucleolus organizer region autoantigen NOR-90 and ribosomal RNA transcription upstream binding factor.

In dividing eukaryotic cells, nucleoli disperse before mitosis and reform in daughter cells at sites of ribosomal RNA (rRNA) gene clusters that are at the secondary constrictions of chromosomes, called nucleolus organizer regions (NORs). In this study, cDNA clones for a NOR autoantigen (NOR-90) were selected using a specific human autoantibody probe and were subsequently identified to encode an alternative form of the reported human upstream binding factor (hUBF). Results from immunoprecipitation showed that anti-NOR-90 antibodies recognized both forms of hUBF/NOR-90. Our data therefore showed that UBF, a critical factor in the regulation of rRNA transcription, was tightly bound to NOR during mitosis even when rRNA synthesis was thought to be minimal. Furthermore, we identified a nucleolar transcription factor as a novel target for human autoimmune response.

Amino Acid Sequence↗
PubMed1991

Production of infectious particles from defective human immunodeficiency virus type 1 (HIV-1)-producing cell clones by superinfection with infectious HIV-1.

A total of 81 cell clones persistently infected with the LAV-1 or HTLV-IIIB strain of human immunodeficiency virus type 1 (HIV-1) was isolated from cells which were obtained by serial passage of some proliferating MT-4 cells after a drastic cytolysis of most cells by HIV-1-infection. These cell clones were classified into 8 types (I to VIII) in terms of the expression of HIV-1 antigens, syncytium formation capacity, and reverse transcriptase activity and infectivity of virus particles in the culture fluid. Type I cell clones were producers of infectious HIV-1 particles, while types II to VIII cell clones did not produce infectious HIV-1 or were producers of uninfectious defective HIV-1 particles. Immunoprecipitation followed by SDS-polyacrylamide gel electrophoresis (PAGE) showed that the gag precursor protein in L-2 cell clone (type IV) was not cleaved to mature gag proteins, while the env precursor protein on L-3 cell clone (type III) was not cleaved to mature env protein. H-7 cell clone (type VIII) did not express any HIV-1 antigen. All these cell clones after the superinfection with infectious HIV-1 synthesized intact gag and env proteins, which were, at least in part, related to the HIV-1 genome persistently present in the cell clones before the superinfection, resulting in production of infectious HIV-1. For example, it was found that L-2 cell clone contained a single copy of the LAV-1 genome per haploid cell and produced doughnut-shaped particles. On the other hand, the cell clone isolated from the L-2 cell clone superinfected with infectious HTLV-IIIB contained the integrated HTLV-IIIB genome in addition to the LAV-1 genome present before the superinfection, and produced intact HIV-1 particles in addition to doughnut-shaped particles from a single cell. These results indicate that complementation and/or genetic recombination events in the superinfected cells may account for the production of infectious intact HIV-1 virions.

Animals↗
PubMed1991

Successful reeducation of functional sensibility after median nerve repair at the wrist.

The effect of sensory reeducation was evaluated in a group of twenty-two adult patients who had a repair of a clean-cut median nerve at the wrist. These results were compared with the sensibility in a group of twenty-four adults with repair of clean-cut median nerve at the wrist who had never received sensory reeducation. The reeducation group were evaluated between one and two years from the time of their median nerve repair. The control patients were retrospectively evaluated between one and sixteen years after their nerve repair. The effect of reeducation on improving the paresthesias that accompany neural regeneration was also evaluated. Sensibility was determined by an object recognition test and by measurement of static and moving two-point discrimination. The results demonstrated that sensory reeducation significantly (p less than 0.01) diminished the severity of postoperative paresthesias. It also gave significantly better improvement in moving two-point discrimination than in static two-point discrimination within the timeframe evaluated (p less than 0.002). Excellent recovery of sensibility, as determined by ability to recognize nine or more objects out of twelve, was significantly greater (p less than 0.005) for the sensory reeducation group than at any time interval beginning after six months after nerve repair. It is concluded that a program of sensory reeducation after median nerve repair at the wrist in adults minimizes discomfort and improves sensibility in the postoperative period.

Adult↗
PubMed1991

GABAergic innervation in cerebral blood vessels: an immunohistochemical demonstration of L-glutamic acid decarboxylase and GABA transaminase.

The presence of GABAergic innervation in cerebral arteries of several species was investigated by an immunohistochemical method using antibodies against glutamic acid decarboxylase (GAD) and GABA transaminase (GABA-T). Both GAD and GABA-T immunoreactivities were found to be associated with large bundles and single fibers in the adventitial layer of arteries examined. The density and distribution pattern of both GAD- and GABA-T-immunoreactive fibers were found to be comparable at most regions examined. Both fibers were found to be most dense in the anterior cerebral artery and its adjacent part of the circle of Willis. Several peripheral arteries were found to receive very sparse or no GAD- and GABA-T-immunoreactive fibers. Superior cervical ganglionectomy did not appreciably affect the distribution of both fibers. Cold-storage denervation, however, resulted in a drastic decrease in both fibers. At ultrastructural levels, both GAD- and GABA-T-immunoreactive nerve profiles were found to be very close to the smooth muscle cells. These results demonstrate the presence of a potentially functional GABAergic innervation in cerebral circulation. On few occasions, GAD immunoreactivities were also found in some endothelial cells, suggesting that a nonneuronal GABA system may also be present in cerebral arteries.

4-Aminobutyrate Transaminase↗
PubMed1991

[Electrolyte abnormality and renal insufficiency in malignant lymphoma; clinical and pathological analysis in 123 cases].

The clinical studies about the electrolyte abnormality (EA) in patients with malignant lymphoma (ML) are rarely reported. We analyzed the EA and renal insufficiency in 123 patients with ML between June. 1976 and Jan. 1989; 8 patients with Hodgkin's disease, and 115 patients with non-Hodgkin's lymphoma (NHL). Before treatment, the incidence of the EA was 24.2% and hypercalcemia, hypocalcemia, and hyperkalemia were predominant. After treatment it became to 74.7% and the number of hyponatremia and hypokalemia increased. The incidence of proteinuria and renal insufficiency (serum creatinine above 1.5 mg/dl), were 7.3% and 2.4% before treatment, and became to 26.8% and 26.8% after treatment, respectively. There was a significant difference between two groups with and without the EA before treatment as for serum lactate dehydrogenase (LDH) levels (p less than 0.01), clinical stages (p less than 0.05) and the incidence of bone marrow involvement (p less than 0.01). In 34 autopsied cases, 3 cases showed massive renal involvement and about a half of cases showed various renal changes. The EA before treatment was caused by extrarenal factors, because the incidence of proteinuria and renal insufficiency were almost same to healthy controls. And renal factors play an important role on the E.A after treatment. Above results suggest that the EA before treatment indicates the progress of malignant lymphoma and the EA after treatment means not only the progress of the disease but also therapy-related renal damages.

Adult↗
PubMed1991

Physical growth of Aymara children in a herding community of the Bolivian Altiplano.

In a small agropastoral Aymara community called Wariscata in the Andean Altiplano of Bolivia, anthropometric measurements were made in 1988. In comparison with those of published data for the other rural and urban Andean populations (Aymara, Quechua and Mestizo at high and low altitudes), the Aymara children of Wariscata were taller and heavier than other rural high altitude native children, but similar in height to urban high altitude children. This is possibly due to secular change of growth accompanied with nutritional improvement that has taken place in recent years. Chest width and depth had similar values to those in other Aymara children. But, Aymara children in Wariscata of both sexes had smaller chest dimensions (depth and width) than those of Quechua children. However, these ethnic differences in chest dimensions were not reflected in the adult Aymara and Quechua, suggesting different process of chest growth in Aymara and Quechua populations.

Adolescent↗
PubMed1991

[Dynamics of extracellular acetylcholine of the gerbil striatum during cerebral ischemia monitored by intracerebral microdialysis].

Neurons in the hippocampus and striatum are vulnerable to the ischemic insult. In the present study we focused on the vulnerability of acetylcholine (ACh)-containing neurons in the striatum. To determine the change of ACh content in the striatum, we employed a simple sensitive brain microdialysis method with high performance liquid chromatography electrochemical detection. Morphological change of cholinergic neurons was studied by ACh-esterase staining during ischemic insult. After bilateral carotid artery occlusion, local cerebral flow decreased less than 5 ml/min/100 g in the striatum. Ach content in dialysate for 20 min after the occlusion was elevated to 135% of the control. ACh content decreased to 15% of the control 2hs after the ischemia. Density of Cholinergic fibers and cell bodies was reduced 10 min after the ischemia and further decreased 20 min after the occlusion. Our study suggests that the transient elevation of ACh content was probably due to diffusion of ACh from destruction cholinergic terminals after the ischemic insult. The increase of ACh immediately after arterial occlusion may affect severity of ischemic damage in the brain by its excitatory effect.

Acetylcholine↗
PubMed1991

[Post-hemiplegic dystonia with a discrete lesion in the postero-lateral part of the contralateral putamen].

We report a 56-year-old man with so-called post-hemiplegic dystonia in the right lower extremity. His cranial CT scans and MRI revealed a small discrete lesion in the postero-lateral part of the contra-lateral putamen. The location of his putaminal lesion did not seem to correspond exactly to the leg area according to the topographical mapping of the monkey putamen. The mechanism of his focal dystonia is discussed including the possibility of the development of dopaminergic hyperactivity in the remaining area of the putamen as an account for his dystonic movement.

Basal Ganglia Diseases↗
PubMed1991

[A case report of advanced gastric cancer responsive to radiotherapy and CDDP arterial injection].

A 48-year-old-male patient with advanced gastric cancer, which extended from corpus to antrum of the stomach and metastasized to the left lobe of the liver, was treated with radiotherapy combined with CDDP arterial injection. Total irradiation and CDDP dosage was 50 Gy/25 f and 150 mg (75 mg/mal/body), respectively. The regression of the tumor was remarkable. For inoperable advanced gastric cancer, radiotherapy combined with anticancer drugs proved a worthwhile therapy, and it was necessary to use the pharmacological characteristics of the drugs.

Adenocarcinoma↗
PubMed1991

[A case of pneumothorax which was operated with the axillary longitudinal small incision].

A pneumothorax usually occurs in young men. From the cosmetic point of view, the size of the skin incision should be considered to be minimal if surgery is applied for young pneumothorax patients. We reported a case of pneumothorax which was operated with a small longitudinal axillary skin incision, the size of which was 3.5 cm long. The patient was a 18-year-old high school student. He was admitted to our hospital with the diagnosis of spontaneous pneumothorax. His chest X-ray showed a moderate collapse of his left lung and bullae in his left apex. Tube drainage was performed and the collapsed lung re-expanded completely. Chest CT scan demonstrated that he had bullae in the apex of his left lung. No other lesions were found in the other part of both lungs. Surgery was indicated socially. Bullectomy was successfully performed with a small (3.5 cm) longitudinal axillary skin incision. We recommend this skin incision for young patients with pneumothorax if the chest CT scan confirms that the bullae or blebs are localized to the apex of superior segment of the lower lobe.

Adolescent↗
PubMed1990

Lack of significantly positive correlations between elemental concentrations in hair and in organs.

Elemental concentrations (Ca, Cu, Fe, Mg, P, Se and Zn) in the hair of Japanese were examined in relation to those in internal organs (cerebrum, cerebellum, heart, spleen, liver, kidney and rib). No significantly positive correlation was found between elemental concentration in hair and that in internal organ. This result indicates the restricted use of hair as a medium for the estimation of nutritional status of the essential elements examined in the present study, at least on an individual basis. The correlations between the concentrations in organs are also presented.

Bone and Bones↗
PubMed1990

Chiral separation and determination of propranolol enantiomers in rat or mouse blood and tissue by column switching high performance liquid chromatography with ovomucoid bonded stationary phase.

Resolution of propranolol (PL) enantiomers in biological samples was accomplished by column switching high performance liquid chromatography using a short precolumn and an analytical column of ovomucoid chiral phase. Plasma, whole blood or tissue homogenate sample was directly injected into the precolumn, and PL was adsorbed on Butyl Toyopearl 650-M. After column switching, the PL was backflushed and transferred to the analytical column (Ultron ES-OVM) by the eluant. Fluorometric detection was carried out at lambda ex = 297 nm and lambda em = 340 nm with a detection limit of 0.5 pmol (signal to noise ratio = 2). The recovery (98.8-103%), reproducibility (coefficient of variance less than 3%) and enantiomer resolution (separation factor 1.15) were satisfactory using as eluant 50 mM sodium dihydrogenphosphate (pH 4.6) containing 12% ethanol. The time course of elimination of PL enantiomers in rat or mouse blood and tissues was also studied.

Animals↗