Biomedical subjects

Y Takagi

Publications and source records attributed to Y Takagi.

At least 271 records · Page 15Linked to original sources

PubMed1996

Protective effect of Astragali Radix by intraperitoneal injection against Japanese encephalitis virus infection in mice.

We examined the protective effect of Astragali Radix extracts (AE) by intraperitoneal injection against Japanese encephalitis virus (JEV) infection in mice. A protective effect was observed by all four samples of AE used. However, the degree of effectiveness for each AE was different. The observed survival rates of the groups injected with sample A (from Shanhsi, Japanese name Sansei-syo) and sample D (from Hokkaido) extracts were higher than 80% at 21 d after JEV inoculation. The groups injected with sample B (from Hopei, Japanese name Kahoku-syo) and sample C (from Hsiahsi, Japanese name Sensei-syo) extracts had a 60% survival rate. The increase in hemagglutination inhibition antibody titer was negligible in mice that survived 21 d after JEV inoculation. The antiviral effect of AE was examined by plaque assay in vitro, but no antiviral effect was shown. In mice injected with AE, the peritoneal exudate cell (PEC) numbers increased significantly, compared to the control. In these PEC, active oxygen production was also high. Also the group as a whole displayed a high survival rate against JEV infection, these were so strong. From these results, we propose that the protective effect of AE is dependent on a non-specific mechanism during the early stage of infection, before it shifts to antibody production, and that PEC plays an important role.

Animals↗

PubMed1996

[Biological properties of the colony-promoting activity in extracts prepared from murine kidney].

Aqueous extracts prepared from the murine kidney (MKE) promoted colony formation derived from murine hematopoietic progenitor cells in serum-free cultures stimulated by interleukin-3 (IL-3) and erythropoietin (Epo). MKE itself did not stimulate any colony formation. MKE preferentially enhanced granulocyte-macrophage colony forming units (CFU-GM), but did not promote any erythroid colony formation. The CFU-GM colony promotion by MKE was observed at day 6 after the culture started, and the colony-promoting activity (CPA) was maintained at the same level until day 16. MKE showed no CPA in the cultures using cells obtained from 5-FU-injected mice and from c-kit(+)-enriched treatment. Furthermore, MKE acted synergistically with granulocyte-colony-stimulating factor (CSF), macrophage-CSF, IL-6 and IL-11 on colony formation, but did not act with GM-CSF, stem cell factor and Epo. From the results of various experiments and gel-filtration chromatography, it is estimated that the colony-promoting factor detected in MKE is a heat stable protein with about 20 KDa molecular weight. These results suggest that MKE promotes colony formation by murine myeloid progenitor cells, and that the target cell populations of MKE are relatively mature in the hematopoietic differentiation pathway.

Animals↗

PubMed1996

Regulation of cartilage glycosaminoglycan synthesis in the rainbow trout, Oncorhynchus mykiss, by 3,3',5-tri-iodo-L-thyronine and IGF-I.

The actions of 3,3',5-tri-iodo-L-thyronine (T3) and recombinant human IGF-I (rhIGF-I) as well as their interaction on cartilage growth in rainbow trout (Oncorhynchus mykiss) were examined. Uptake of 3H-methyl thymidine and 35S-sulfate by isolated branchial cartilage was measured as a marker for chondrocyte proliferation and sulfated glycosaminoglycan synthesis respectively. When T3 (1.0 microgram/g) was injected intraperitoneally, plasma T3 levels reached a transient peak after 1 day and decreased rapidly thereafter. Sulfate and thymidine uptake were not affected by T3 at 1 and 3 days post-injection, but at 6 days post-injection both were significantly higher in T3-injected fish than those in controls. The stimulatory effects of a T3 injection on sulfate and thymidine uptake were dose-dependent over the range of 0.01, 0.1 and 1.0 micrograms/g. In vitro exposure of cartilage to T3 (0.075, 0.75, 7.5, 75 and 750 nM) for 6 days resulted in dose-dependent stimulation of sulfate uptake, with a maximum response at 7.5 nM and higher. T3 exposure (7.5 nM) for 2 or 3 days also increased sulfate uptake, but only slightly. Thymidine uptake was not clearly affected by T3. In vitro addition of rhIGF-I (0.075, 0.75 and 7.5 nM) increased sulfate uptake, but not thymidine uptake, dose-dependently. Compared with T3, rhIGF-I induced a greater maximum level of sulfate uptake: at 7.5 nM rhIGF-I increased the uptake 17-fold whereas T3 increased the uptake fourfold. When T3 (0.075, 0.75 or 7.5 nM) and rhIGF-I (0.1 or 1.0 nM) were added together, stimulative actions of T3 on sulfate uptake were largely additive to those of rhIGF-I. The results indicate that T3 as well as IGF-I are important modulators of sulfated glycosaminoglycan synthesis in rainbow trout cartilage.

Animals↗

PubMed1996

A substance secreted from Tetrahymena and mammalian sera act as mitogens on Paramecium tetraurelia.

We previously isolated and purified Paramecium growth factor (ParGF) from a cell-free fluid of an early stationary mass culture of Paramecium tetraurelia (Tanabe et al., 1990). The mitogenic activity of the purified ParGF and of the crude sample (ca. a 100-fold concentrate obtained by ultrafiltration of cell-free fluid) has been assessed based on restoration of the fission rate of the jumyo mutant of P. tetraurelia in daily reisolation cultures. With this assay system, we found that crude samples of Tetrahymena pyriformis and T. thermophila showed mitogenic activity. This suggests that Tetrahymena cells secrete a mitogenic factor(s) like ParGF. To some extent, fetal bovine serum (FBS) and calf serum (CS) also acted as mitogens on the jumyo mutant. Of nine mammalian growth factors assayed for their mitogenic effects on the jumyo mutant, epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) were slightly and occasionally effective. These results support the idea of actual use of similar kind of growth factors to control cell divisions from protozoa to mammals.

Animals↗

PubMed1996

[A clinical study of radial prostatectomy].

BACKGROUND: The objective of this study is to evaluate the efficacy of radical prostatectomy for patients with organ-confined prostate cancer. METHODS: From 1990 to 1994, a total of 50 patients with prostate cancer underwent radical retropubic prostatectomy. RESULTS: Eleven patients were in state A2, 34 in stage B and 5 in stage C according to clinical stage. Extended disease was observed pathologically in 45%, and 59% of patients in clinical stages A2 and B, respectively. Preoperative serum PSA levels were closely correlated with pathological extension of the disease. The disease-free rates for organ-confined disease, extended disease without lymph node metastasis and stage D1 disease were 75% (3 years), 82% (2 years) and 80% (3 years), respectively. Four patients had rectal injuries, and three of these underwent temporary colostomy diversion. Two patients had bladder neck contracture and received internal urethrotomy. Urinary incontinence improved in 60% of patients during the first 6 post-operative and in 90% of patients within 12 post-operative months. Urinary incontinence tended to improve earlier in patients with nerve-sparing than those without it. The erectile capacity in nerve sparing patients recovered good. CONCLUSION: Our results indicate that radical prostatectomy is a safe and temporarily satisfactory treatment for the patient with organ-confined prostate cancer.

Adenocarcinoma↗

PubMed1996

[Cut-off values and grey-zone of tumor markers in blood].

Cut-off values and grey-zone of tumor markers in blood were described. Cut-off values are a little different from reference intervals, and can discriminate tumor status from non-tumor status. Cut-off values are commonly determined by ROC (receiver operating characteristic) curve, that can show us the diagnostic efficiency of the test. The patients of control group used in ROC curve must be selected from benign diseases whose conditions are similar to those of tumors. Grey-zone is defined as the range between cut-off value from healthy subjects and that from benign diseases. Cost-efficiency must be considered when cut-off values and grey-zone of tumor markers in blood were set up.

Biomarkers, Tumor↗

PubMed1996

A case of strangulated transomental hernia diagnosed preoperatively.

A patient with an unusual case of internal hernia was treated successfully with surgery for strangulated transomental hernia, diagnosed preoperatively by abdominal computed tomographic examination (CT). The herniation occurred through congenital defects in the gastrocolic omentum. Herniation of this nature is extremely rare, and abdominal CT examination is very useful for preoperative diagnosis.

Adult↗

PubMed1996

[Analysis of cyclin dependent kinase inhibitors, p16INK4a and p15INK4b gene, in acute lymphoblastic leukemias].

We examined the abnormality of p16INK4a and p15INK4b genes in 14 cases of human acute lymphoblastic leukemias (L1; 8 sample from 6 cases, L2; 10 samples from 7 cases, L3; 1 sample from 1 case) using DNA from bone marrow cells. The frequency of homozygous deletion of p16INK4a was 21.4% (3/14) and that of p15INK4b was 7.1% (1/14) and both genes were deleted in 7.1% (1/14) according to Southern blot and PCR analysis. The deletion of p16INK4a and/or p15INK4b was detected in 50% (3/6) of L1, 28.6% (2/7) of L2. The frequency of deletion was 33.3% (3/9) of B cell origin, 66.7% (2/3) of T cell origin and 0% (0/2) of nonBnonT cell origin. By PCR-SSCP analysis on exon 1 and exon 2 of p16INK4a and p15INK4b genes, we detected one case of unusual migrated band in L1 B cell origin. The base substitution, C to G, located in intron 1 of p15INK4b, 9 base upstream of intron 1-exon 2 boundary, was determined by DNA sequencing analysis. Deletion of p16INK4a and/or p15INK4b gene may contribute to etiology of ALL.

Adolescent↗

PubMed1996

The effect of a hematopoietic-promoting factor (HPF) extracted from porcine kidney on the proliferation of human hematopoietic progenitor cells.

Hematopoietic-promoting factor (HPF), which was found in porcine kidney, has been demonstrated to act synergistically with colony-stimulating factor and erythropoietin on murine myeloid colony formation. We investigated the effect of HPF on the proliferation of human hematopoietic progenitor cells prepared from cord blood cells (CB) and peripheral blood cells (PB). HPF enhanced granulocyte colony-stimulating factor plus interleukin-3 and erythropoietin-induced colony formation, where the number of colonies were increased by 7.9-fold in CB and by 1.8-fold in PB, respectively. When we compared the effect of HPF with stem cell factor (SCF) on the colony formation derived from PB in serum-free cultures, HPF enhanced the number of erythroid burst-forming units (BFU-E) to the same extent as SCF. But the effect of HPF on promoting the growth of granulocyte-macrophage colony-forming units (CFU-GM) was less than SCF. When the enriched CD34+ cells from CB and PB were incubated in liquid culture with HPF and IL-3 for 7 days, CFU-GM was increased by 48-fold in CB, and by 25-fold in PB, respectively. The data demonstrate that HPF can potentiate expansion of hematopoietic stem cells to the same extent as SCF, and that the effects of HPF on hematopoitic stem cells differ from that of SCF.

Adult↗

PubMed1996

[Multi-drug resistance of serovar E strains in clinically isolated Pseudomonas aeruginosa and analysis of genome pattern].

We analyzed the in vitro antibiotic susceptible pattern and serovar for 132 strains of pseudomonas aeruginosa (98 from inpatients and 34 from outpatients) isolated at Showa University hospital from September to December of 1993. The ratio of resistant strains was 38.6% for carbenicillin, 12.1% for piperacillin, 12.9% for ceftazidime, 12.1% for cefsulodin, 17.4% for cefoperazone, 9.1% for cefclidin, 24.2% for cefpirome, 7.6% for imipenem, 17.4% for amikacin, 16.7% for aztreonam, 89.4% for minocycline and 33.3% for ofloxacin. The incidence of resistance against minocycline, carbenicillin, ofloxacin was markedly high. Among the 132 tested strains of Pseudomonas aeruginosa, 16 were multi-drug resistant strains (i.e., resistant to more than 8 drugs out of 12 drugs), and 14 of the multi-drug resistant strains (87.5%) were isolated from inpatients. Multi-drug resistant strains were isolated most frequently from urine specimens. The antibiotics that remained effective against the multi-drug resistant strains included amikacin, imipenem, cefclidin and cefsulodin. The serovar of 116 strains (resistant to up to 7 drugs) was 27 for G, 24 for B, and 19 for E, and 15 of the 16 multi-drug resistant strains showed serovar E. Restriction enzyme SpeI digestion analysis (using pulse field electrophoresis) of P. aeruginosa having serovar E revealed common 650kb and 540kb bands in multi-drug resistant strains. The genome pattern was quoted for serovar E strain according to the restriction enzyme digestion pattern and was shown to be useful for tracing the route of infection.

Drug Resistance, Microbial↗

PubMed1996

Quantification of intestinal blood flow by ultrasonic transit time flowmetry in fed and endotoxaemic rats.

OBJECTIVE: To compare the dye dilution method with ultrasonic transit time flowmetry (UTTF) for quantifying intestinal blood flow in the same experimental animals. DESIGN: Open experimental study. SETTING: University hospital, Osaka, Japan. MATERIAL: 11 (experiment 1) and 25 (experiment 2) adult male Sprague-Dawley rats. INTERVENTIONS: In experiment 1, the rats were fasted overnight. In experiment 2, endotoxin, Escherichia coli lipopolysaccharide (endotoxin) or saline (sham) was injected intraperitoneally. MAIN OUTCOME MEASURES: Superior mesenteric venous and abdominal aortic blood flow. RESULTS: Experiment 1: intestinal blood flow measured by UTTF was significantly decreased by 17% (p < 0.05) and 56% (p < 0.05) after 30 minutes infusion through the tertiary branch of the mesenteric vein and during simultaneous drawing of blood samples from both the carotid artery and the superior mesenteric vein over a 1.5 minute period, respectively. The intestinal blood flow measurements obtained by UTTF at different intervals before simultaneous drawing of blood from the carotid artery and the superior mesenteric vein differed significantly (p < 0.05) from those obtained by the dye dilution method. Experiment 2: intestinal blood flow was also decreased by 21%-34% (p < 0.05) during similar simultaneous drawing of blood. Aortic blood flow in the endotoxin group was reduced by 66% (p < 0.05) compared with fed animals and 63% (p < 0.05) compared with sham animals. Simultaneously, intestinal blood flow in the endotoxin group was also reduced by 57% (p < 0.05) compared with fed or 48% (p < 0.05) compared with sham treated animals. CONCLUSION: Real intestinal blood flow might not be measured by the procedure of simultaneously drawing blood from the carotid artery and the superior mesenteric vein in rats as is usually done in the dye dilution method. Intraperitoneal endotoxin reduced aortic as well as intestinal blood flow. We propose that UTTF is an alternative method for quantifying intestinal blood flow in fed and endotoxaemic animals.

Animals↗

PubMed1995

Transcription of the rat liver uricase-encoding gene is regulated via a cis-acting element responsive to cAMP.

Glucagon was found to increase the mRNA level of the uricase-encoding gene (UOX), but not that of genes encoding other peroxisomal enzymes, such as catalase, acyl-CoA oxidase and enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase. The possible involvement of cAMP in the glucagon-induced transcription of rat UOX was studied by measuring the enhancer activity of the isolated 5'-untranslated region of the gene. An 84-bp sequence spanning positions -169 to -86 was found to be essential for cAMP-mediated expression of rat UOX, on deletional analysis of the upstream 1.4-kb portion by means of a transient transfection assay (CAT assay). The 30-mer oligodeoxyribonucleotide (positions from -169 to -140) was found to form a DNA-protein complex by an electrophoretic mobility shift assay. The core sequence for the DNA-protein complex formation, 5'-CAAAAATGTC-3', was found to be located in positions from -164 to -155. In addition, the binding assays suggested that the DNA-binding protein(s) was different from cAMP-response element binding protein (CREB). Thus, this report shows that a novel cis-acting element of rat UOX and the binding protein(s) possibly play an essential role in the glucagon-induced transcription via cAMP.

Animals↗

PubMed1995

Herniation and entrapment of a nerve root secondary to an unrepaired small dural laceration at lumbar hemilaminectomies.

STUDY DESIGN: The authors encountered a unique case of nerve root herniation 9 days after multiple lumbar partial hemilaminectomies with discectomy were performed for lumbar canal stenosis combined with lumbar disc hernia. OBJECTIVE: The treatment of this patient involved surgical repair even though the dural laceration was small and the arachnoid was intact. SUMMARY OF BACKGROUND DATA: There have been no reports of nerve root herniation into the facet joint through the arachnoid space after laminectomy, except in cases of extradural distention of the arachnoid membrane. METHODS: The patient presented with weakness of the right lower extremity and underwent partial hemilaminectomies and discectomy for lumbar canal stenosis. Nine days after surgery, he suddenly experience severe pain in the left S1 region. Neither myelography nor computed tomography-myelography revealed pathologic findings before the second operation. At surgery, herniation of the S1 nerve root was found. Surgical correction of the herniated nerve root at the level of the left L5 vertebra was performed. RESULTS: This correction completely relieved the pain in the left S1 region. CONCLUSION: This herniation resulted from an unrepaired minor dural laceration. The arachnoid membrane was intact during the first operation. Even a small tear in the spinal dura requires surgical closure to prevent herniation and entrapment of a nerve root. It is necessary to repair even small dural lacerations with no spinal fluid leakage during spinal surgery.

Diskectomy↗

PubMed1995

Distinct mutational spectrum of the p53 gene in lung cancers from Chinese women in Hong Kong.

Accumulating evidence suggests that the p53 gene is a good target for molecular epidemiological studies to search for risk factors in carcinogenic events. The lung cancer incidence for females in Hong Kong is unusually high, ranking among the highest in the world despite a low percentage with a history of smoking. To gain insights into possible etiological risk factors responsible for this high incidence, we examined p53 mutations in 35 lung cancer specimens from Chinese females living in Hong Kong and compared them with 35 matched cases from Japanese women as well as previously reported p53 mutations in the world literature. p53 mutations in exons 5-8 were present in 20 and 31% of the Hong Kong and Japanese cases, respectively. Notably, single-base deletions within runs of identical bases were observed in 3 (43%) of the 7 mutations in the Hong Kong cases, in contrast to the absence of such mutations in the controls and the extreme scarcity in the literature, suggesting that distinct environmental and/or genetic factor(s) might be involved. Although the frequent occurrence of characteristic single-base deletions could be a reflection of mutator mutations leading to inefficient mismatch repair of slipped strand mispairings, none of the lung cancer specimens exhibited such microsatellite instabilities.

Adult↗

PubMed1995

Results of revascularization in patients with severe left ventricular dysfunction.

BACKGROUND: In patients with coronary artery disease and poor ventricular function (ejection fraction, < 20%), bypass grafting remains a surgical challenge. This study evaluates experience with isolated revascularization in such patients. METHODS AND RESULTS: In 79 consecutive patients (69 men, 10 women; average age, 59 +/- 9 years), preoperative ejection fraction was 18 +/- 5%. Indications for surgery were congestive heart failure (CHF) in 5 of 79 patients (6%), CHF and angina in 19 (24%), angina in 41 (52%), ventricular arrhythmias (VAs) in 8 (10%), and critical anatomy in 6 (8%). Some patients had prior VAs (23 of 79; 29%) or mitral regurgitation (18; 23%) and required emergent surgery (25; 32%). At surgery, temperature mapping ensured adequate distribution of antegrade cold cardioplegia, with 3.6 +/- 0.7 grafts per patient, including left internal mammary artery graft in 60 of 79 (76%) and endarterectomy in 14 (18%). Hospital mortality was 3.8%. Perioperative support included intra-aortic balloon pump in 18 of 79 (23%) and drugs for VAs in 28 (35%). Morbidity included myocardial infarction in 2 of 79 (2.5%) and stroke in 2 (2.5%). During follow-up, there were 19 late deaths. Actuarial survival was 94%, 82%, and 68% at 1, 2, and 5 years, respectively, and was similar in patients with severe angina, CHF, mitral regurgitation, or VAs. Freedom from sudden death was 100%, 98%, and 91% at 1, 2, and 5 years, respectively. Among survivors, angina improved in 84% and heart failure improved in 26%. CONCLUSIONS: These data support bypass graft surgery in patients with severe LV dysfunction. With careful cardioplegic techniques, hospital mortality was low (3.8%). Long-term survival is encouraging, with good relief of symptoms in most patients. Perioperative VAs are frequent but respond to medical treatment, with only 23% of patients discharged on antiarrhythmic drugs. Five-year freedom from sudden death is 91%, with only 3 late sudden deaths in this series.

Actuarial Analysis↗

PubMed1995

Is sex a factor in determining operative risk for aortocoronary bypass graft surgery?

BACKGROUND: This study examines trends and sex differences in characteristics of patients referred for bypass graft surgery to identify factors associated with operative morbidity and mortality. METHODS AND RESULTS: Data were collected prospectively on consecutive patients (1132 men and 355 women). Over time, the proportion of patients > 65 years old, with diabetes, or requiring urgent surgery, increased. Predictors of mortality were age > 75 years, urgent surgery, and poor left ventricular (LV) grade. Women were older (62 +/- 9 versus 59 +/- 9 years, P < .001) and had more varicose veins (18% versus 7%, P < .001), diabetes (27% versus 18%, P < .001), hypertension (48% versus 41%, P < .05), peripheral vascular disease (16% versus 12%, P < .05), and more severe angina (P < .001). There were no sex differences in prior myocardial infarction (59% versus 62%) or need for urgent surgery (17% versus 18%). Women had a higher ejection fraction (51% +/- 12% versus 47% +/- 14%, P < .001) and fewer diseased vessels (2.4 +/- 0.7 versus 2.6 +/- 0.6, P < .001) and received fewer grafts (2.9 +/- 0.9 versus 3.3 +/- 0.8, P < .001). Women had smaller body size but were no more likely to have small target vessels (< 1.5 mm). There was no sex difference in operative mortality (1.4% versus 1.1%), perioperative myocardial infarction (4.8% versus 3.5%), need for intra-aortic balloon pump (10% versus 8%), stroke (1.7% versus 1.4%), reexploration for bleeding (1.7% versus 1.7%), or leg infection (2.0% versus 1.4%). Women had fewer sternal wound infections (0.6% versus 2.2%, P < .05). CONCLUSIONS: Predictors of mortality include advanced age, decreased LV function, and need for urgent surgery. With time, despite increasing age, associated diabetes, and increased urgent surgery, operative mortality has decreased. Women were older and had more diabetes and hypertension but less extensive disease and better LV function. Bypass graft surgery was associated with equally low mortality in women and men (1.4% versus 1.1%). Concern over increased operative mortality in women should not bias referral patterns for angiography and coronary bypass graft surgery.

Aged↗

PubMed1995

Regulation of placenta-specific expression of the aromatase cytochrome P-450 gene. Involvement of the trophoblast-specific element binding protein.

The aromatase (cytochrome P-450AROM) gene contains multiple untranslated exons I that are differentially transcribed in a tissue-specific manner. DNA sequences within the initial -301 upstream of placenta-specific exon I (exon Ia) are sufficient for placenta-specific expression of aromatase. In gel mobility shift assay, three separate domains in this region form specific binding complexes with proteins extracted from choriocarcinoma JEG-3 nuclei. A fragment containing these domains activates transcription driven by a heterologous promoter in a cell type-specific manner. Two of the binding domains that form major complexes in gel shift assay compete with each other and with a DNA fragment containing the trophoblast-specific element (TSE), which is derived from the enhancer region of the human chorionic gonadotropin alpha-subunit gene and is believed to confer placenta-specific expression of the gene. The core sequence RNCCTNNRG is sufficient for recognition of the TSE-binding protein, which is detected only in nuclear extracts prepared from placenta and choriocarcinoma. A mutation introduced in the distal TSE core in aromatase promoter resulted in marked reduction of transcriptional activity, although TSE region by itself did not show enhancer activity as that in human chorionic gonadotropin alpha-subunit gene.

Aromatase↗

PubMed1995

A novel activity associated with RNA polymerase II elongation factor SIII. SIII directs promoter-independent transcription initiation by RNA polymerase II in the absence of initiation factors.

General transcription factor SIII, a heterotrimer of 110-, 18-, and 15-kDa subunits, was shown previously to stimulate the overall rate of RNA chain elongation by RNA polymerase II by suppressing transient pausing by polymerase at many sites along DNA templates (Bradsher, J. N., Jackson, K. W., Conaway, R. C., and Conaway, J. W. (1993) J. Biol. Chem. 268, 25587-25593). In this report, SIII is shown to possesses the novel ability to direct robust but promiscuous transcription by RNA polymerase II on duplex DNA templates in the absence of initiation factors. Mechanistic studies reveal that SIII promotes RNA synthesis by substantially increasing the efficiency with which RNA polymerase II initiates promoter-independent transcription from the ends of duplex DNA. Remarkably, SIII appears to have a negligible effect on de novo synthesis of end-to-end transcripts. Instead, analysis of reaction products indicates that SIII is capable of promoting a dramatic increase in the ability of RNA polymerase II to extend the 3'-hydroxyl termini of duplex DNA fragments, in a template-directed reaction exhibiting no strong preference for 3'-protruding, 3'-recessed, or blunt DNA ends. Although RNA polymerase II has been shown previously to catalyze primer-dependent transcription, SIII is the first eukaryotic transcription factor found to promote this reaction. Based on these findings, we propose that SIII may suppress transient pausing by RNA polymerase II by helping to maintain the 3'-hydroxyl terminus of the nascent RNA chain in its proper position in the polymerase active site.

Aging↗