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H Sakai

Publications and source records attributed to H Sakai.

At least 1,045 records · Page 58Linked to original sources
PubMed1988

A runaway-replication plasmid pSY343 contains two ssi signals.

Taking advantage of the plaque morphology method, we detected two single-stranded initiation (ssi) signals in the plasmid pSY343; one was in the 170-nucleotide (nt) EcoRV-ThaI segment (170P), and the other was in the 93-nt DraI-FnuDII segment (93F), which were designated as ssiA and ssiB, respectively. We cloned the two ssi signals in the filamentous phage vectors M13 delta lac184 and flR199. A conserved 7-nt consensus sequence involved in the n' recognition site for priming DNA initiation on single-stranded (ss) DNA templates (A. Van der Ende, R. Teerstra, H. Van der Avoort, and P.J. Weisbeek, 1983, Nucleic Acids Res. 11, 4957-4975) was found, three copies in 170P and one in 93F. These two ssi signals contain possible stem and loop structures. The 170P overlapped partly with the origin (ori) region of pSY343 and the 93F was away from the ori region. Growth of chimera phages such as M13 delta lac184/ssiA and M13 delta lac184/ssiB was 38- and 71-fold greater, respectively, than that of M13 delta lac184, 8 h after phage infection. The conversion efficiency in vivo of ss to replicative form (RF) DNA of these chimera phages carrying ssiA and ssiB was 1.9- and 2.2-fold greater, respectively, than that of M13 delta lac184, 50 min after infection.

Base Sequence↗
PubMed1988

Cellular immunoregulatory aspects of IgA nephropathy.

Polyclonal activation of IgA-producing B cells has been observed in the majority of patients with IgA nephropathy (IgAN) and some of their family members. The precise mechanism of such activation is presently unknown. However, abnormalities of T and B cell interactions have recently been observed in this disease. These abnormalities include the decrease of IgA-specific suppressor T cell activity and the increase of IgA-specific helper T cell activity. A T cell subpopulation with receptors for the Fc portion of IgA and with CD4 antigens (ie, T alpha 4 cells) has been proposed as a candidate of IgA-specific switch T cells that convert IgM-producing B cells to IgA-producing B cells. Further analysis of the immunogenetic mechanism and the clinical correlates of the cellular immunoregulatory aspects of IgAN is necessary to elucidate the pathogenesis of this disease.

B-Lymphocytes↗
PubMed1988

Gingival pigmentation beneath a metallic crown: light and electron microscopic observations and energy dispersive X-ray analysis.

Light and electron microscopic studies and energy dispersive X-ray analysis disclosed that the essential cause of gingival discoloration following the placement of a metallic crown, was marked deposition of melanin pigment. Deposition of melanin pigment was observed in epithelial cells, on basement membranes, and in fibroblasts, macrophages and among intercellular ground substance of the proprial layer. Brown or dark brown colored granules were observed in the deep portion of the proprial layer. Some metallic elements as silver and sulfur were detected. It was presumed that these materials were dental metals accidentally implanted in gingival tissues during the therapeutic procedure. The deposition of melanin pigment closely corresponded with mucosal tissue where these materials were present in the deep portion of the proprial layer. These findings suggested that these materials influenced the physiological metabolism of melanin and induced its pathological deposition in the proprial tissue.

Adult↗
PubMed1988

Detection of glomerular sialic acids in patients with diabetic nephropathy.

A study on immunofluorescence of sialic acids in glomeruli from patients with diabetic nephropathy is described. Measurement of sialic acid in sera from 25 patients with diabetes mellitus was also performed. Renal biopsy specimens from 12 patients with diabetic nephropathy were stained with FITC-labeled antihuman IgG antiserum and rhodamine-labeled Triticum vulgaris (WGA) or Limulus polyphemus (LPA). These specimens were also stained with such reagents after treatment with neuraminidase, trypsin or citrate buffer. Both deposition of IgG and binding of WGA in the glomerular capillary walls were observed in all patients with diabetic nephropathy. The binding of WGA in the glomerular capillary walls in diabetic nephropathy was significantly increased compared with that in four normal renal tissues. However, the binding of LPA was hardly observed in the glomerular capillary walls of patients with diabetic nephropathy. The binding of WGA in the glomeruli was markedly decreased after treatment with neuraminidase although it was hardly decreased after treatment with trypsin or citrate buffer. The levels of sialic acid in sera from patients with diabetic nephropathy were markedly increased. It is suggested that accumulated substances in the glomerular capillary walls with an affinity for WGA are mainly composed of N-acetyl glucosamine and/or N-acetyl neuraminic acid in patients with diabetic nephropathy.

Adult↗
PubMed1988

Levels of circulating IgA immune complexes after gluten-rich diet in patients with IgA nephropathy.

Measurement of IgA circulating immune complexes (IgA-CIC) in sera from patients with IgA nephropathy after a gluten-poor diet, an unrestricted diet and a gluten-rich diet is described. High levels of IgA-CIC in sera were detected in patients after these diets. However, the levels of IgA-CIC in sera 2 weeks after the gluten-rich diet were not significantly increased compared with those after the other diets. It is suggested that, for a short duration, the gluten-rich diet might not increase the levels of IgA-CIC in sera from Japanese patients with IgA nephropathy.

Adolescent↗
PubMed1988

Instability of eye position in the dark in cerebellar degeneration.

Fourteen cases of spinocerebellar degeneration were examined. While the patients attempted to keep their eyes in the primary position, horizontal eye movements were recorded for 1 min in total darkness by infrared reflection oculography. Instability of eye position in the dark was observed in 10 patients. The range of the eye position error was 3-6 degrees in 6 patients, 6-10 degrees in 3 patients and over 10 degrees in 1 patient. These results indicate that the cerebellum plays an important role in extraretinal (nonvisual) eye position control.

Adult↗
PubMed1988

Dual effect of antimitotic drugs on steroid secretion in mouse adrenocortical Y-1 tumor cells.

Mouse adrenocortical Y-1 tumor cells were examined in a monolayer culture and their steroid secretion was measured. The Y-1 cells constantly released a small amount of steroids in the absence of adrenocorticotropin (ACTH). When synthetic ACTH (tetracosactide acetate) was added to the medium, an increase in the steroid secretion of approximately 5-fold was observed. The Y-1 cells also showed a typical cytoplasmic retraction in response to ACTH. Incubation of the cells with an antimitotic drug, colchicine, prior to ACTH-stimulation resulted in a 30-50% reduction in ACTH-induced steroid secretion. Under the conditions used in these experiments, viable numbers of cell and of total amount of protein per dish were not measurably changed, indicating that the condition was not lethal. Another antimitotic drug, colcemid, caused similar reactions, while lumicolchicine showed no effect. This suggests that the disruption of the microtubular system is the main cause of the inhibition. On the other hand, the ACTH-independent secretion was slightly enhanced by colchicine. The enhancement was also observed in prolonged incubation with colchicine, a condition which caused death in some of the cells.

Adrenal Cortex Neoplasms↗
PubMed1988

A novel 53 kDa actin binding protein from porcine brain--further biochemical and immunological characterization.

We have previously described some of the characteristics of an actin binding protein, 53 K protein, purified from porcine brains. The purification procedure was revised in order to investigate of this actin binding protein further. A Scatchard plot analysis showed that the association constant between actin and the 53 K protein has around the same value as those reported for the fascin-actin and for the filamin-actin interactions. The binding experiments also demonstrated the occurrence of competitive binding with other actin binding proteins such as filamin, alpha-actinin, caldesmon and tropomyosin for the actin filament. Antibody was produced against brain 53 K protein and further purified on an affinity column. Immunoblot analysis using the antibody showed that this protein is localized in both the soluble and membraneous fraction of the brain. Other tissues such as liver and lung also contain 53 K protein. The immunoblot analysis also revealed that the gelation product of rat brain extract described by Palmer et al. contains immunoreactive polypeptides having slightly lower molecular weights and more basic isoelectric points than porcine brain 53 K protein. Immunological localization of the 53 K protein within HeLa and BS-C-1 cells showed that this protein is distributed throughout the cell in small granules, and in some regions of the cell, these granules were aggregated into much larger granules.

Actins↗
PubMed1988

Stimulation of the phosphorylation of cytoskeletal 350-kDa and 300-kDa proteins by insulin-like growth factor-I, platelet-derived growth factor and phorbol ester in rat 3Y1 cells.

Insulin-like growth factor-I (IGF-I) stimulated the phosphorylation of cytoskeletal 350-kDa and 300-kDa proteins which were immunoprecipitated with antibodies against brain high molecular weight microtubule-associated proteins in quiescent rat 3Y1 cells. The data on the effective concentrations of IGF-I and 125I-labeled IGF-I binding indicated that type I IGF receptors mediate this IGF-I effect. Platelet-derived growth factor (PDGF) as well as phorbol ester (TPA) also stimulated the phosphorylation of these proteins. These proteins, whether immunoprecipitated from cells stimulated by insulin, IGF-I, TPA, PDGF, or epidermal growth factor, produced very similar phosphopeptide mapping patterns irrespective of the stimulant. The results suggest the possibility that these growth factors and phorbol esters may activate a common protein kinase which is responsible for the phosphorylation of the 350-kDa and 300-kDa proteins in cells.

Animals↗
PubMed1988

The amino acid sequence, immunofluorescence and microinjection studies on the 15 kDa calcium-binding protein from sea urchin egg.

The 15 kDa protein is the most abundant low molecular weight Ca2+-binding protein, different from calmodulin, in eggs of sea urchin, Hemicentrotus pulcherrimus. The data from the amino acid sequence demonstrated that the 15 kDa protein belonged to the troponin C superfamily. Based on immunofluorescent and immunomicroscopic observations, we showed that the 15 kDa protein localized in the nuclei of fertilized eggs and mitotic apparatus of dividing eggs. Microinjection of the antibody against 15 kDa protein into sea urchin blastomeres resulted in the arresting of cell division. These results suggest that the 15 kDa protein plays an important role in mitosis of sea urchin egg.

Amino Acid Sequence↗
PubMed1988

[Cardiohemodynamic and respiratory effects of eptazocine, a new analgesic agent, in anesthetized dogs].

Cardiohemodynamic and respiratory effects of eptazocine, a new analgesic agent, were studied and compared with those of pentazocine and butorphanol in anesthetized dogs. Eptazocine (1 mg/kg, i.v.) increased the heart rate (HR), left ventricular dP/dt (LVdP/dt) and cardiac output (CO), and scarcely affected the blood pressure (BP), left ventricular end-diastolic pressure (LVEDP), right atrial pressure, pulmonary arterial pressure (PAP) and pulmonary capillary wedge pressure. On the other hand, eptazocine (3 mg/kg, i.v.) decreased BP, LVdP/dt, CO and LVEDP and did not influence the pulmonary circulation. Pentazocine (1 mg/kg and 3 mg/kg, i.v.) increased BP, LVdP/dt and CO, while HR was not altered. Pentazocine also increased PAP. Butorphanol (0.1 mg/kg and 0.3 mg/kg, i.v.) decreased BP, HR and LVdP/dt, while other hemodynamic parameters were not changed. In spontaneously breathing anesthetized dogs, eptazocine (1 mg/kg and 3 mg/kg, i.v.) caused a decrease of respiratory minute volume. The fall in PO2 and pH, and a rise in PCO2 were simultaneously observed in blood gas analysis. These respiratory depressant effects of eptazocine were short-lasting, and they were less potent than those of pentazocine. Butorphanol scarcely affected the respiration. These results suggest that eptazocine has different cardiohemodynamic effects than other analgesics and produces mild respiratory depression.

Analgesics↗
PubMed1988

Mutagenicity of the ash of rice straws by Ames' test.

Mutagenicity of fly ashes and bottom ashes of rice straw and rice husk was assayed by Ames' test. With respect to rice-straw ash, the extract from the fly ash was found to be more mutagenic than that from the bottom ash. In the case of rice husk, the mutagenicity of extract from the bottom ash was stronger than that from the fly ash. The extract from rice-husk bottom ash showed the strongest mutagenic activity among the four.

Air Pollutants↗
PubMed1988

Serial changes in acute extradural hematoma size and associated changes in level of consciousness and intracranial pressure.

The authors report the cases of 37 patients encountered during the past 4 years who exhibited acute extradural hematoma but were initially treated conservatively because no or only small hematomas were observed on admission. The frequency of hematoma enlargement, hematoma size, and changes in the level of consciousness and intracranial pressure (ICP) were examined in these patients. The hematomas enlarged in 24 (64.9%) of the 37 patients, and attained a maximum thickness of 25 mm or greater in 19 patients (51.3%). The level of consciousness could be closely observed during enlargement of the hematomas in 13 patients: the level remained unchanged in eight, deteriorated in two, and improved in three, indicating relative stability in the state of consciousness despite the marked changes in hematoma size. The patients whose hematoma enlarged after the initial examination included three who underwent initial CT examination 5 hours after the injury. In five patients enlargement of extradural hematomas was observed unexpectedly during conservative treatment under ICP monitoring. The ICP also remained stable in three patients until the follow-up examination, but showed a rapid increase in two after a period of stability. However, there was no difference in the final size of the hematomas between the patients showing an increase in ICP and those who did not. These findings suggest that extradural hematomas enlarge progressively at rates varying with the condition of the source of hemorrhage. Moreover, a period of stability in the level of consciousness, such as the lucid interval seen in patients with extradural hematoma, is considered to be a period during which compensatory mechanisms can maintain the stability of the intracranial condition during progressive enlargement of the hematoma.

Adolescent↗
PubMed1988

Small cell carcinoma of the urinary bladder: a case of remarkable remission with combined chemotherapy.

A 67-year-old man presented with asymptomatic gross hematuria. Cystoscopy and radiographic studies revealed a large tumor on the left lateral wall of the urinary bladder. Also, computer tomographic (CT) scan of the pelvic cavity showed metastasis to the left external iliac node. The light microscopic appearance of cold punch biopsy specimens for the tumor was closely akin to small cell carcinoma of the lung. Ultrastructurally, the tumor cells exhibited small numbers of neurosecretory granules in the cytoplasm. After surgical treatment, the patient was treated with combined chemotherapy using cis-diamminedichloroplatinum (CDDP) and etoposide. On CT scan, a remarkable remission was shown to have been induced at the metastatic site after three cycles of the therapy. Though the morphology of bladder tumors has not received very much attention, this report emphasizes that detailed pathological examination is of therapeutic importance.

Aged↗