Biomedical subjects
Publications and source records attributed to Y Okuno.
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Although it is well established that the addition of 1,25-dihydroxyvitamin D3 (D3) to the culture of normal human granulocyte/macrophage progenitors induces monocyte/macrophage (Mo/M phi) colonies, the target cells of D3 in the Mo/M phi differentiation have not been identified. We examined whether neutrophilic promyelocytes are the target cells. As a source of the promyelocyte fraction, we used colonies after 5 days of culture (5-day colonies) of colony-forming unit-granulocyte. The culture contained granulocyte colony-stimulating factor (G-CSF) as the growth factor and generated only neutrophilic colonies. The promyelocytic nature of the 5-day colonies was confirmed morphologically, cytochemically, and ultrastructurally. After morphological evaluation on part of the individual colonies, they were transferred into new semisolid cultures with or without D3 (10(-7) mol/L) in the presence of G-CSF, then incubated for the subsequent 7 days. With D3, the colonies were loose, and all the constituent cells were morphologically small macrophages, which were positive for alpha-naphthyl butyrate (alpha NB) esterase, strongly positive for CD14 antigen, and plastic-adherent. While without D3, the colonies were rather compact, and all the constituent cells were morphologically mature neutrophils, which were positive for naphthol ASD-chloroacetate esterase and weakly positive for CD14 antigen. Secondary culture of the 8- or 10-day colonies with D3 induced a lower number of alpha NB-positive cells, in proportion to the percentage of promyelocytes at the time of transfer in each colony. Four days of secondary culture with D3 was sufficient to induce alpha NB-positive cells. G-CSF was not an essential factor to induce alpha NB-positive cells. These findings indicate that D3 differentiates normal human neutrophilic promyelocytes into the Mo/M phi lineage in vitro.
We describe the isolation of human LH-2, a putative transcription factor containing two cysteine-rich regions (LIM domains) and a homeobox (Hox) DNA-binding domain. High levels of hLH-2 expression were observed in all cases of chronic myelogenous leukaemia (CML) tested, regardless of disease status. hLH-2 was mapped to chromosome 9Q33-34.1, in the same region as the reciprocal translocation that creates the BCR-ABL chimera of the Philadelphia chromosome (Ph'), the hallmark of CML; hLH-2 was retained on the derivative 9 chromosome and is therefore centromeric of c-ABL. The proximity of hLH-2 to the breakpoint on chromosome 9 raises the possibility of cis-activation by the t(9;22)(q34;q11) translocation. In addition to finding hLH-2 expression in all cases of CML, expression was observed in lymphoid malignancies and myeloid cell lines, but not in primary cases of acute myelogenous leukaemia. The role of hLH-2 in the development or progression of leukaemia is not known. However, hLH-2 may prove useful as a marker of CML for monitoring residual disease.
Between 1985 and 1995, mass outbreaks of acute gastroenteritis caused by small round-structured virus (SRSV), occurred in eight prefectures in Japan. Fecal samples from 59 patients ill during these outbreaks were recently examined in our laboratory by electron microscopy (EM) and by reverse transcription-polymerase chain reaction (RT-PCR). For RT-PCR, we prepared two sets of primers, a set corresponding to the polymerase region of open reading frame 1 (ORF-1) and a set corresponding to the capsid region of ORF-2 of Norwalk virus (NV). The SRSV nucleic acid detection rate with these primers was more than double that achieved with EM. Most samples found by EM to contain virus particles were also positive by PCR. When the two sets of primers were used separately, the virus detection rate differed depending on the primer used, suggesting that the viral strains examined were not genetically not homogeneous. We then selected nine strains of the virus, cloned their PCR products and analyzed their base sequences. The base sequences of these strains were compared with those of reference strains including prototype NV and Snow Mountain agent (SMA). This comparison yielded the following findings: (1) SRSVs that cause mass outbreaks of gastroenteritis in Japan are genetically variable; (2) SRSV strains that are genetically similar to SMA and SRSV-OTH 25/89/J(OTH25) are dominant in Japan, but strains similar to NV are also present in this country; and (3) a strain (MI1/94) which is genetically identical to Southampton virus (SHV) was detected. Detection of SRSV using sensitive RT-PCR and analysis of the sequences of the amplification products seems to provide a useful means of studying the molecular epidemiology of SRSV.
We have identified specific nucleotide sequences involved in autonomous replication of human chromosomal fragments in human cells. Nested deletion analysis of a 10.2-kb long human chromosomal fragment showed that replication efficiency of the fragment was reduced to about 50% by loss of a short specific segment. Deletions outside the segment reduced the replication efficiency depending on their lengths. By introducing linker substitutions, we found that the distinct segment required for the efficient replication consisted of an 18-bp sequence, named REE1 (Replication Enhancing Element 1). Single or tandem copies of REE1 alone had no significant replication activity, but they stimulated replication of human chromosomal DNA fragments. We found, in addition, that the REE1 sequence inserted at a site 2.7 kb upstream of the SV40 early promoter caused repression of transcription from the promoter, suggesting that REE1 had a transcriptional silencer activity. Introduction of linker substitutions into the REE1 indicated that the nucleotide sequences required for the repression of transcription were the same as those for enhancement of replication. Thus, REE1 is responsible for both enhancement of replication and repression of transcription.
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A restriction fragment library representing 89.3% of the genome of Trichoplusia ni granulosis virus (TnGV) was constructed. The library consisted of 13 of the 16 BamHI fragments, 18 of the 22 EcoRI fragments, and 6 of the 27 PstI fragments. By restriction endonuclease and Southern blot analysis of cloned or genomic viral DNA fragments, a complete physical map of TnGV was constructed for BamHI, EcoRI, PstI and XhoI. Three interspersed homologous regions (ihs1-ihs3) were identified from hybridization experiments and sequenced. Each TnGV ihs has an approximate size of 400 bp and shows homology to the other two. The orientation of ihs2 is inverted relative to ihs1 and ihs3. TnGV ihs regions do not have repetitive motifs or palindromic sequences, in contrast to homologous regions (hrs) of nuclear polyhedrosis viruses (NPVs). The genomic locations of TnGV ihs1-ihs3, represented in percentage map units, were very similar to those of ihs sequences previously reported in Bombyx mori NPV, suggesting that the ihs may be a novel type of cis-acting element common among baculoviruses. Additionally, an inverted repeat sequence, having overlapping, multiple inverted repeats of 400 bp, was identified to the left of ihs3 on the linearized genome map of TnGV.
A deletion mutant of influenza virus haemagglutinin (HA; headless HA) lacking the globular region was expressed in CV-1 cells and detected with a monoclonal antibody, C179, which recognizes a conformational epitope in the middle of the stem region of HA and neutralizes all H1 and H2 subtypes. The cDNA coding for the headless HA was constructed from influenza virus A/Okuda/57 (H2N2), which was also used to select C179. The conformational epitope recognized by C179 was highly stable even after removal of the globular region. The survival rate of mice immunized with the headless HA and challenged with lethal influenza virus A/FM/l/47 (H1N1) was significantly higher than that of the control mice. The headless HA has the potential to induce cross-protection against influenza virus infection.
Trends in the incidence of female breast and cervical cancers were examined, using the cancer registry data in Miyagi Prefecture, Japan, during 1959-1987. The age-standardized incidence rate of breast cancer has been increasing, while that of cervical cancer has been decreasing. Age-period-cohort models were applied to clarify the trends in incidence. For breast cancer incidence, the age-period model adequately represented the data, and demonstrated that the risk of developing breast cancer has been increasing in recent time periods. The effect of cohort on breast cancer incidence was insignificant and the full model containing age, period and cohort showed irregularities in the cohort effect. For cervical cancer incidence, the effect of period was significant, while the effect of cohort was marginal. The full model containing age, period and cohort showed that cervical cancer risk has been decreasing in recent time periods and younger birth cohorts. Using published reports, we investigated the trends in the prevalence of various risk factors and compared them with the trends in the incidence at both sites. It is suggested that the effects of period and cohort might be related to the changes in the prevalence of these risk factors as well as to improvements of the diagnostic procedures.
To clone and express the genes encoding major antigens of Entamoeba histolytica, we constructed a lambda gt11 cDNA library for E. histolytica HM1:IMSS and screened it with pooled sera from patients with amoebiasis. A 1,223-bp cDNA was cloned (clone 1223), and its nucleotide sequence was determined. The amino acid sequence predicted to be encoded by the open reading frame of clone 1223 consisted of 396 residues and showed 32.5 and 32.3% homology to the NADH-dependent butanol dehydrogenases I and II (bdhA and bdhB) of Clostridium acetobutylicum, respectively. In addition, 29 of the 34 consensus positions of bdhA and bdhB were also well conserved in clone 1223. The recombinant protein expressed from clone 1223 had an estimated molecular mass of 43.5 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The antigenicity and specificity of the recombinant protein were evaluated by an enzyme-linked immunosorbent assay using sera obtained from two clinical groups of patients with amoebiasis and a group of healthy controls. The recombinant protein had potent and specific antigenicity. In all, 53 serum samples (88.3%) from 60 patients with amoebiasis were positive for immunoglobulin G antibody against the recombinant protein, with a mean optical density value of 0.42. In contrast, 53 of 54 healthy control serum samples were negative, with only 1 positive serum sample showing the lower optical density value. These results suggested that clone 1223 is promising in terms of providing a useful antigen for the accurate serodiagnosis of amoebiasis and that the gene encodes a putative alcohol dehydrogenase of E. histolytica.
PURPOSE: The MR findings in patients with spastic diplegia were investigated and the role of MR imaging in assessing the extent of brain injury was evaluated. MATERIAL AND METHODS: 39 male and 24 female patients (preterm/term 43/20) were imaged using a 0.5 T MR system. RESULTS: The MR findings in term patients were quite different from those in preterm patients; 55% of the term patients showed normal and minimal changes on MR, whereas 90.7% of the 43 preterm children had periventricular leucomalacia. The deep cerebral white matter was the most frequently involved site. Objective measurements revealed significant reductions of the entire sagittal area of corpus callosum in diplegic patients in comparison with normal controls. The motor palsy severity correlated well with the extent of corpus callosum involvement. CONCLUSION: The corpus callosum appears to be a sensitive marker site for the assessment of the extent of white matter injury.
To clarify the changes of esophageal motility along with age, we performed esophageal manometry on 47 healthy volunteers, and compared the values of four groups under 49 years old (n = 11), 50 to 59 (n = 15), 60 to 69 (n = 11), and over 70 years old (n = 10). Resting lower esophageal sphincter (LES) pressure in the group over 70 years old showed the tendency of decrease, but not statistically significant. Nadir LES pressure on swallow-induced relaxation was not statistically different among 4 groups. On esophageal body testing, percentage of non-conduction sequence in the group 60 to 69 and over 70 years old was statistically higher compared with that of the group under 49 years old (p < 0.05) but spared in some elderly subjects. Percentage of simultaneous contractions was not statistically different among 4 groups. Peristaltic contraction amplitude in the group over 70 years old was significantly lower than that of the group under 49 years old both at the level of 5 cm above (p < 0.01) and 10 cm above LES (p < 0.05). We speculate that the influence of aging on esophageal motility is the reduced transmission sequence of peristalsis and contractility of esophageal body. This alteration along with age may differ from the pathological condition of scleroderma or diffuse esophageal spasm.
PURPOSE: To investigate changes in blood pressure during intracarotid injection of contrast material. METHODS: Two catheters were inserted into the ipsilateral common carotid artery of dogs. The proximal catheter was used for injection of contrast material and the other was positioned distally to monitor blood pressure. RESULTS: Distal intracarotid pressure rose significantly during injection of contrast material at all rates (5, 7, and 10 mL/s) and at all doses (0.2, 0.5, 0.7, and 1.0 mL/kg). In addition, these blood pressure elevations were shown to be correlated with injection rates and doses. Even when the pressure-monitoring coaxial catheter was advanced into smaller arteries, no decline in the impact of injection was observed. CONCLUSION: Intracarotid injection of contrast material causes a temporal elevation of cerebral blood pressure in dogs.
We examined whether the repeated oral administration with a high dose of L-3-(3,4-dihydroxyphenyl)-alanine (L-DOPA) in 0.5% carboxymethyl cellulose increases serum luteinizing hormone (LH) levels in male rats. Serum LH levels were increased 4 h after a single administration of 1000 mg/kg L-DOPA to male rats, and returned to control levels within 8 h after administration. Four hours after a single administration, serum LH levels were significantly increased by L-DOPA at 1000 mg/kg, but not at 20, 100 or 200 mg/kg. Decreases in body weight and relative weight of the prostate were observed after 7 and 14 days of administration of 1000 mg/kg per day L-DOPA, but no changes were observed in weight of the testis, epididymis or seminal vesicle. The administration of L-DOPA at 500 or 1000 mg/kg per day for 7 or 14 days resulted in increased basal serum LH levels and decreased basal serum prolactin levels 24 h after the last administration. Serum testosterone levels tended to be higher in treated than in control rats. The levels of two metabolites of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), in rats treated with 500 mg/kg per day tended to be slightly higher than those in control rats after 7 days of administration. Levels of DA, DOPAC and HVA were significantly increased after 7 and 14 days of administration of 1000 mg/kg per day and after 14 days of administration of 5000 mg/kg per day. The level of norepinephrine, but not its metabolite 3-methoxy-4-hydroxyphenylglycol, was significantly increased after only 7 days of administration of 1000 mg/kg per day. No significant changes were observed in levels of 5-hydroxytryptamine or its metabolite 5-hydroxyindole-3-acetic acid with administration of 500 or 1000 mg/kg per day. These findings suggest that a prolonged treatment with a high dose of L-DOPA in male rats induces release of LH from the pituitary, resulting in sustained elevation of LH levels in peripheral circulation.
This study demonstrates unique reactivity of the C-1027 chromophore toward a tRNA(phe). In the presence of Mg2+ ions where the tRNA(phe) attains a stable three-dimensional structure, the enediyne chromophore exhibits high cleavage selectivity to the anticodon arm. The present reactivity of the C-1027 chromophore is useful in development of new chemical probes for mapping of tertiary RNA structure. Considering the paucity of RNA repair mechanisms, RNA may be also an important biological target for certain enediyne antibiotics.
Impaired bone formation due to defective osteoblast function, as reflected in a decreased serum osteocalcin (OC) concentration in the patients with diabetes, has been implicated in the development of diabetic osteopenia. The role of hyperglycemia in this decrease in serum OC concentration was investigated. 1,25-dihydroxyvitamin D3 (1,25[OH]2D3), an active form of vitamin D3, stimulated OC secretion from the human osteosarcoma cell line MG-63 in a dose-dependent manner. Exposure of the cells to high concentrations of glucose for 7 days significantly impaired 1,25(OH)2D3-induced OC secretion as compared with that observed with cells maintained under normal glucose (5.5 mM) or high mannitol conditions. The inhibitory effect of glucose was in a dose-dependent manner up to 55 mM. High glucose (55 mM) also attenuated the 1,25(OH)2D3-induced increase in OC mRNA abundance in MG-63 cells, suggesting that the inhibition of the 1,25(OH)2D3-induced increase in OC secretion by exposure to a high concentration of glucose was, at least in part, mediated at the transcriptional level. High glucose significantly decreased the number of 1,25(OH)2D3 receptors in MG-63 cells, without any change in the dissociation constant for 1,25(OH)2D3; this effect was not mimicked by high mannitol, indicating specificity for glucose. These observations suggest that a high glucose concentration significantly impairs the ability of osteoblastic cells to synthesize OC in response to 1,25(OH)2D3 by reducing 1,25(OH)2D3 receptor number, and that impaired cell function caused by sustained exposure to high glucose contributes to the defect in bone formation observed in the patients with diabetic osteopenia.
Oxolinic acid (1-ethyl-1,4-dihydro-6,7-methylenedioxy-4-oxo-3- quinolinecarboxylic acid), an antimicrobial agent, raises the serum levels of luteinizing hormone (LH) and increases the incidence of testicular Leydig cell tumors in male rats. In the present study the mechanism by which serum LH levels are raised in male rats receiving oxolinic acid was investigated. Aged Wistar rats were fed a diet containing oxolinic acid at 0 or 3000 ppm for more than 4 weeks. There was no effect of oxolinic acid on either the maximal levels of serum LH after castration nor on the serum levels of LH stimulated with 1 microgram/rat of luteinizing hormone-releasing hormone (LHRH). The concentrations of testosterone in serum and testis were not changed by the treatment of oxolinic acid. In the in vitro organ culture, the testes of rats receiving oxolinic acid released testosterone in the same manner as the controls, in the presence or the absence of human chorionic gonadotropin (100 mIU/ml). The oxolinic acid-stimulated serum LH was not increased further by the daily administration of L-dopa (500 mg/kg/day, po, 7 days) and was blocked by the injection of a dopamine antagonist, haloperidol (2 mg/kg, ip). In a microdialysis study, oxolinic acid increased the extracellular concentration of dopamine in the preoptic area of hypothalamus. These findings suggest that a high dietary level of oxolinic acid elevates LH release from the anterior pituitary with an increase in LHRH, in part, by the excitatory input of a dopaminergic system in the preoptic area of rat hypothalamus.
A generalized hypersensitivity reaction against human insulin was demonstrated in a non-insulin dependent diabetic man treated with only human insulin. The patient had no history of previous insulin exposure or atopy. Because of negative reactions to intracutaneous tests of constituents of the formulation and the presence of insulin-specific IgE antibody, this generalized allergic reaction seems to have been caused by the human insulin itself. Although desensitization was not effective, this allergic reaction was improved both by the treatment with oral antihistamines and desensitization. Cases of generalized and primary allergy against human insulin have been rarely reported making this a very rare case.