[Isolation and properties of gamma-chains from human fetal hemoglobin].
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Biomedical subjects
Publications and source records attributed to K Taniguchi.
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Serum gamma-fetoprotein (AFP) and plasma des-gamma-carboxy prothrombin (DCP), a protein induced by vitamin K absence or antagonist II (PIVKA-II) levels, were measured in 197 patients with primary hepatocellular carcinoma (HCC). DCP levels were determined by conventional enzyme immunoassay kit (E-1023) and a newly developed high-sensitivity kit using the avidin-biotin complex method. Cut-off levels of AFP and DCP by the E-1023 kit and of DCP by the high-sensitivity kit were put at 100 ng/ml, 0.1 arbitrary unit (AU)/ml, and 0.004 AU/ml, respectively. Positive rate of AFP and DCP by the E-1023 kit and the high-sensitivity kit for HCC was 48%, 44%, and 57%, respectively. The positive rate by combination assay with AFP and DCP by the high-sensitivity kit increased up to 73%. There was no correlation between serum levels of AFP and those of plasma DCP. A significant correlation between tumor size and DCP levels was observed, but not with AFP. The postoperative disease-free survival rates of patients in the group with elevated levels of AFP and DCP were lower than those with normal levels of AFP and DCP. There were various patterns of change in the AFP and DCP levels at the time of recurrence compared with preoperative patterns. The combination assay of AFP and DCP levels is useful for the diagnosis, prognosis, and postoperative monitoring for recurrence of HCC.
A total of 154 clones of reassortants between rotavirus RRV and SA11 were isolated in vitro in order to compare the selection modes of each RNA segment in reassortant formation with those in the in vivo experiment (carried out by Gombold and Ramig) using the same parent strains in which the occurrence of non-random selection of gene segments 3 and 5 was observed. In reassortants isolated from a cross RRV x SA11-L2 (66 isolates) and a cross RRV x SA11-S1 (88 isolates), 36 and 57 different genotypes were identified, respectively. Segregation rates of SA11 RNA segments 1, 5, 8, 9 and 11 were significantly different as compared with those previously reported in the in vivo experiment. While RNA segment 3 was preferentially selected from an SA11 parent, the segregation rate of SA11 gene 5 was relatively low in vitro. Thus, the selection mode of rotavirus RNA segments was found to be different between in vivo and in vitro reassortments.
We previously reported non-random selections of human rotavirus (HRV) Wa genes 2 and 5 in reassortant formation between HRV strains Wa and HN126 under selection pressure with neutralizing monoclonal antibodies. In order to study whether or not these genes are preferentially selected in the genetic background of a parental strain HN126 in vitro without selection pressures, coinfection and multiple passage experiments were performed between HN126 and one of three reassortants, C1, C1T and C1F; C1 possessed genes 2 and 5 derived from Wa and the other genes derived from HN126, while C1T and C1F were single gene reassortants having Wa gene 2 or Wa gene 5 in the genetic background of HN126, respectively. When MA-104 cells were coinfected with the same infectious units of HN126 and C1, Wa genes 2 and 5 of reassortant C1 became predominant within 10 repeated passages, although Wa gene 5 was selected more preferably than Wa gene 2. Similar results were obtained under different experimental conditions in which different doses of parental strains or different type of cells were used. Also, in coinfections of MA-104 cells with HN126 and C1T, or HN126 and C1F, Wa gene 2 or Wa gene 5 became predominant at the sixth passage. Analysis of viral growth curves indicated that two reassortants, C1 and C1F, replicated to a titre higher than HN126, while no difference in viral growth was observed between C1T and HN126. These results indicated that in the genetic background of HN126, Wa gene 5 might provide viruses with a growth advantage compared with its HN126 counterpart, while Wa gene 2 might be preferentially selected into reassortant clones through its greater functional capacity for assortment during viral replication.
One difficulty involved in gene therapy for diabetes is a control of proinsulin production by the cells transfected with insulin cDNA. The introduction of a feedback mechanism to control the expression of the introduced gene based on the host's need for insulin is one possible treatment approach. To control proinsulin production at a transcriptional level, we introduced a glucocorticoid responsive promoter in the 3' region of insulin cDNA in reverse orientation (pBCMGS-neo-Ins-invMMTV) so that antisense insulin mRNA is produced in response to glucocorticoids. When fibroblasts transfected with pBCMGS-neo-Ins-invMMTV were cultured with 1 x 10(-5) M dexamethasone, two of nine clones showed a 10-20% reduction in proinsulin production. On the other hand, all clones of the cells transfected with a control vector containing human insulin cDNA (pBCMGS-neo-Ins) showed an 20-80% increase of proinsulin production when cultured with dexamethazone because of the increase of protein synthesis by glucocorticoids. These data indicated that antisense insulin mRNA effectively suppressed the transcription of insulin cDNA in response to glucocorticoids. This sense-antisense regulation system may make it feasible to induce a feedback mechanism to control proinsulin based on the blood glucose concentration.
Intrahepatic bile duct proliferation (ductular reaction) was examined histologically, immunohistochemically and ultrastructurally in four cases of canine liver disease, diagnosed as chronic hepatitis, liver fibrosis, cirrhosis and cholangiocellular carcinoma. Ductular reaction was a common finding in all cases. Most of the proliferated bile ducts were similar to normal bile ducts. In addition, duct-like structures occurred, consisting of hepatocytes and of intermediate cells that had phenotypic characteristics of both cholangiocytes and hepatocytes. The proliferated bile ducts were immunohistochemically negative for proliferating cell nuclear antigen (PCNA) and stem cell factor (SCF). The proliferated bile ducts in these four cases of canine liver disease thus showed both typical ductular reactions, such as elongation and tortuosity of the existing bile ducts, and atypical ductular reactions resulting from metaplasia of hepatocytes.
The relation between preoperative left ventricular (LV) systolic function at rest and postoperative LV response to exercise was assessed in 13 patients with aortic regurgitation (AR) and nine patients with aortic stenosis (AS). Preoperative end-systolic volume index (ESVI) and ejection fraction (EF) determined by LV angiography were compared with postoperative exercise-induced changes of LV fractional shortening (delta %FS) and mean velocity of fiber shortening (delta mVcf) assessed by echocardiography. Preoperative EF and ESVI in 13 patients with AR correlated well with postoperative delta %FS and delta mVcf. Similarly, preoperative EF and ESVI in nine patients with AS correlated well with postoperative delta %FS and delta mVcf. Our study demonstrated that preoperative LV systolic function in AR and AS patients closely reflected postoperative LV response to exercise. Preoperative smaller ESVI will be warranted to expect a favorably good postoperative LV response to exercise.
The reactivity of five anti-human rotavirus VP4 neutralizing monoclonal antibodies (N-mAb) with 20 animal rotavirus strains and three unusual human rotavirus (HRV) strains was investigated. Five N-mAb prepared previously by the immunization of mice with HRV were employed in this study. They were found to neutralize HRV belonging to P types 4, 6 and 8, which were designated according to P (or VP4) type nomenclature proposed by Estes and Cohen (1989). A porcine rotavirus strain Gottfried was reactive with four of the five mAb both in neutralization tests and in ELISA. However, no other animal rotaviruses were neutralized by any of the mAb. Fourteen animal strains were reactive with only one or two mAb in ELISA, and five animal strains were inactive with all. These results indicate that neutralization epitopes on VP4 are serologically considerably different between HRV (except for unusual Indonesian strains 57M and 69M) and animal rotaviruses (except for porcine rotavirus strain Gottfried).
A number of antigenic mosaic reassortants which have neutralization proteins VP4 and VP7 derived from different parental strains were analysed in order to study gene selection in reassortant formation between animal and human rotaviruses (HRV). These reassortants were isolated from mixed infection of MA-104 cells with canine rotavirus strain K9 (subgroup I and G serotype 3) and HRV strains (with subgroup I or II antigen and G serotype 1-4, 9 or 12 antigen), through repeated selections with anti-VP4 and anti-VP7 neutralizing monoclonal antibodies directed specifically at HRV and K9, respectively. By serological and genomic analyses, all the isolated clones were found to be antigenic mosaic reassortants possessing VP4 of K9 and VP7 of HRV. In the reassortants between strain K9 and one of the six strains of subgroup II HRV, a single or a few genotypes with particular constellations of RNA segments were predominant, with only a few RNA segments including gene 4 (encoding VP4) being derived from K9. In contrast, in the reassortants between strain K9 and any one of the subgroup I HRV, more than nine different genotypes were identified and various RNA segments, except for segments 8 and 10, were derived from K9. These findings indicated that the RNA segments of K9 might be reassorted more readily with those of subgroup I HRV than with those of subgroup II HRV, suggesting the possible existence of functional mechanisms which determine the extent of diversity of genome selection depending on the pairs of parent strains in the reassortant formation.
Overall genomic relatedness among five equine rotavirus strains and their relatedness to representative human and animal rotavirus strains were investigated by RNA-RNA hybridization tests. The genomes of strains FI-14, FI-23 and H2 were highly related to one another. Strain L338 had only a low degree of genomic relatedness to the other four equine rotavirus strains. Strain H1 also showed little genetic relatedness to the other equine strains. The genome of the strain H1, however, was highly related to those of porcine rotavirus strains OSU, Gottfried and YM. Genomic relatedness of four equine rotavirus strains (FI-14, FI-23, H2 and L338) to human and other animal rotavirus strains was low, whereas several RNA segments of strain H1 showed a relatedness to those of human strain Wa.
A total of 200 clones of reassortants were generated in vitro between simian rotavirus SA11 (SA11-L2 strain) and each of five human rotavirus (HRV) strains with different antigenic specificities and RNA patterns. When culture fluid coinfected with parent viruses was subjected to repeated selection with anti-HRV-VP4 and anti-SA11-VP7 neutralizing monoclonal antibodies, all yielded progenies were antigenic mosaic reassortants possessing VP4 and VP7 derived from SA11 and HRV, respectively. In genomic analysis of viral RNA by PAGE, two and five different genotypes were identified in 40 clones, generated between SA11 and HRV strain Hochi (G serotype 4, G4) and between SA11 and KU (G1), respectively. In contrast, 11 and 17 genotypes were found in progenies between SA11 and subgroup I G2 HRV strain HN126 or DS-1, respectively. Although SA11 genes, except for the VP7 gene, were predominant in most reassortants, gene 5 was preferentially selected from HRV. Incorporation of HRV segments 1, 3 and 10 into progenies was more frequent in SA11 x HN126 and SA11 x DS-1 reassortants than in other reassortants. These results indicated that the extent of diversity of reassortant genotypes differs between the two groups of the parental HRV strain; one has subgroup I specificity and a short RNA pattern (DS-1 genogroup), while the other has subgroup II specificity and a long RNA pattern (Wa genogroup).
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