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T Hsu

Publications and source records attributed to T Hsu.

At least 55 records · Page 3Linked to original sources
PubMed1993

A Drosophila single-strand DNA/RNA-binding factor contains a high-mobility-group box and is enriched in the nucleolus.

We have isolated a Drosophila melanogaster cDNA encoding a high-mobility-group (HMG) box-containing protein. This protein shares 50% amino acid identity with the human putative structure-specific recognition protein, hSSRP. The gene encoding the D. melanogaster homolog, DssRP, is developmentally regulated and is expressed most abundantly in ovaries (nurse cells in particular). The protein is localized in nuclei and is particularly abundant in the nucleolus. In vitro binding studies using DssRP produced in bacteria showed that, despite expectation, the protein does not bind to structured DNA. Instead, it binds to single-stranded DNA and RNA, with highest affinity to nucleotides G and U.

Amino Acid Sequence↗
PubMed1993

Predictive factors for successful surgical outcome of benign prostatic hypertrophy.

Four hundred patients with benign prostatic hypertrophy (BPH) undergoing prostatic surgery were enrolled in this study in order to search for factors predictive of a successful outcome. 139 patients had acute urinary retention and the others had irritative and obstructive voiding symptoms. Preoperative examinations included intravenous urography (IVU), transrectal sonography of the prostate (TRSP), cystometry, uroflowmetry, and urethral pressure profilometry (UPP). Retropubic prostatectomy was undertaken in 16 cases, transurethral resection of the prostate in 335, and transurethral incision of the prostate in 49. In the follow-up period of 3 months to 3 years, a strictly successful result was achieved in 324 patients (81%). 26 patients (6.5%) had a fair result, 30 (7.5%) were stationary, in 18 (4.5%) the symptoms became worse, and 2 (0.5%) died postoperatively. On analysis of the success rate, 9 favorable factors and 9 unfavorable factors were noted. A symptomatic large prostatic adenoma proven by IVU, TRSP, or UPP will imply a higher success rate. Urodynamically obstructive BPH proven by a high voiding pressure and constrictive flow pattern can also predict a satisfactory outcome. The unfavorable factors always come from a small adenoma, uncertain irritative symptoms and detrusor underactivity. Patients with more than 2 unfavorable factors should be investigated carefully before surgery. The presence of 2 favorable factors without an unfavorable factor will usually predict the best surgical outcome.

Aged↗
PubMed1993

Extracorporeal shock wave lithotripsy for obstructed proximal ureteral stones. A prospective randomized study comparing in situ, stent bypass and below stone catheter with irrigation strategies.

In an attempt to assess the usefulness of a ureteral stent in facilitating disintegration of obstructed proximal ureteral stone with extracorporeal shock wave lithotripsy (ESWL), a prospective randomized study on 120 patients with ultrasonic evidence of hydronephrosis whose stone sizes were greater than 1.0 x 0.6 cm on KUB film and located above the level of L5 were allocated into three distinct treatment strategies: group 1: in situ without stone manipulation; group 2: bypass stones with stent, and group 3: placement of a catheter below stone with continuous saline irrigation. Of 77 patients, 26, 27 and 24 in each group, followed up for a period of 6 months with sufficient data for analysis, the stone-free rates were 76.9, 59.3 and 62.5%, respectively. The average number of shock waves delivered to accomplish a stone-free state were 3,245, 3,250 and 3,880 for individual groups and the comparisons among them were statistically insignificant (p's > 0.1). ESWL retreatment was common, being 33.3, 29.4 and 43.8%, respectively. Hydronephrosis has a major impact on the outcome of ESWL treatment, as more stone-free cases were found in the mildly hydronephrotic category than in the severer counterparts. About 90% of cases who finally were stone-free, passed all their stone fragments within 28 days. Ancillary procedures were needed in 13 (16.9%), 7 received ureterolithotomy, whilst 6 were removed of their stones by ureteroscopy.

Adult↗
PubMed1992

Sequence discrimination by alternatively spliced isoforms of a DNA binding zinc finger domain.

Two major developmentally regulated isoforms of the Drosophila chorion transcription factor CF2 differ by an extra zinc finger within the DNA binding domain. The preferred DNA binding sites were determined and are distinguished by an internal duplication of TAT in the site recognized by the isoform with the extra finger. The results are consistent with modular interactions between zinc fingers and trinucleotides and also suggest rules for recognition of AT-rich DNA sites by zinc finger proteins. The results show how modular finger interactions with trinucleotides can be used, in conjunction with alternative splicing, to alter the binding specificity and increase the spectrum of sites recognized by a DNA binding domain. Thus, CF2 may potentially regulate distinct sets of target genes during development.

Alternative Splicing↗
PubMed1992

Multiple zinc finger forms resulting from developmentally regulated alternative splicing of a transcription factor gene.

Transcripts encoding the Drosophila putative transcription factor CF2 are subject to developmentally regulated alternative splicing, and they encode protein isoforms that differ in the number of zinc fingers. One testis-specific RNA encodes an isoform that includes three zinc fingers and a frame-shifted segment. Two other transcripts encode isoforms with six and seven zinc fingers which bind to distinct promoters and DNA target sequences. Thus, because of alternative splicing, a single gene appears to encode distinct DNA-binding proteins, each capable of regulating different gene sets in different tissues and developmental periods.

Amino Acid Sequence↗
PubMed1992

Technique of reflection electron microscopy.

Details of the technique of reflection electron microscopy (REM) are described. Step by step instruction is given on how to do it on an ordinary electron microscope. Also given are some specimen preparation techniques and strategy of REM investigation.

Microscopy, Electron↗
PubMed1992

Urodynamic findings in interstitial cystitis.

Fifty patients with irritative voiding symptoms and a painful bladder when full were engaged in this study to clarify the role of urodynamics in the diagnosis of interstitial cystitis (IC). Patients underwent urodynamic study, cystoscopic hydrodilatation of the bladder under general anesthesia and bladder biopsy. Twenty-eight women and two men who presented with signs of glomerulations or petechial hemorrhage of the bladder mucosa were classified as having IC, while 20 women without this characteristic were classified as having non-IC. A hypersensitive urge sensation, a small bladder capacity, a lower maximal flow rate and an abnormal flow pattern were observed in both groups of patients, but no significant difference was noted. More IC patients had a lower bladder compliance than non-IC patients (p < 0.025), and the maximal bladder capacity under anesthesia was smaller in IC patients (p < 0.05). However, there does not seem to be any definite correlation to the pathologic findings, except in patients with marked bladder inflammation, in whom a small capacity and severe clinical symptomatology were found.

Adult↗
PubMed1991

A new classification of female stress urinary incontinence--based on transrectal sonographic cystourethrography.

A new classification of female stress urinary incontinence was made according to the results of transrectal ultrasonography of the urinary bladder and urethra (cystourethrography) studied in 67 women with genuine stress urinary incontinence (SUI). This classification is based on the following changes of the bladder and urethra on abdominal straining: hypermobility of the urethra, bladder neck incompetence, urethral sphincter incompetence and presence of a cystocele. Five types of SUI has been classified. We believe that this new classification can provide a better understanding of the anatomical changes as well as the pathophysiology of SUI. In addition, it can serve as a guideline of proper surgical management for SUI.

Adult↗
PubMed1990

Transcriptional mapping of a DNA replication gene cluster in bacteriophage T4. Sites for initiation, termination, and mRNA processing.

A phage T4 genetic cluster that encodes DNA polymerase, several other DNA replication proteins, transcriptional factors, and the translation repressor RegA has been shown to be controlled by overlapping modes of transcription which initiate at several promoters. The promoters were mapped by using a combination of assays including Northern blotting, S1-mapping, RNA sequencing, and analysis of products of radioactive labeling of 5' ends on T4-induced RNA in vitro via the reaction catalyzed by eukaryotic guanylyl transferase (RNA capping assay). The most proximal in the cluster are two promoters that do not require any phage-induced factors for activation, i.e. they are T4 early promoters. Initiation at these promoters yields several RNA species having overlapping 5'-terminal sequences, the largest of which is estimated to be about 15,000 nucleotides long and to include all the cistrons of the cluster. A third early promoter maps inside the protein encoding segment of one of the cistrons (T4 gene 47), while at least five additional promoters map in intercistronic regions and are T4 middle promoters, i.e. they require the T4-induced DNA-binding transcription factor MotA. Transcriptional readthrough at a termination site within the T4 gene 45-44 intercistronic region is required for synthesis of gp44 and gp62, two essential T4 DNA-polymerase (gp43) accessory proteins. In contrast, transcription of T4 gene 43 is serviced by readthrough across a termination site in the regA-43 intercistronic region as well as by a MotA-dependent promoter that maps downstream of the termination site, and the region contains a site for processing by a T4-induced enzyme that also cleaves elsewhere in the polycistronic mRNA from the cluster (i.e. in the Shine-Dalgarno sequence of the gene 45.2 mRNA). The termination events in the gene 45-44 and regA-43 intercistronic regions both occur downstream of RNA stem-loop structures containing the sequence 5'CUUCGG3' in the loop segments. Transcription termination in the 78-base-pair regA-43 intercistronic region occurs about 60 nucleotides away from the gp43 initiator AUG, transcription initiation occurs at 38-40 nucleotides upstream from the AUG, and T4-dependent RNA processing occurs at several sites (including a GGAG sequence) between the transcription termination and initiation sites. Thus, all gp43-encoding mRNAs contain the translational operator (residues -40 to -1 relative to the AUG) for autogenous repression by this DNA polymerase (Andrake et al., 1988).(ABSTRACT TRUNCATED AT 400 WORDS)

Base Sequence↗
PubMed1990

Biotransformations of carboxylated aromatic compounds by the acetogen Clostridium thermoaceticum: generation of growth-supportive CO2 equivalents under CO2-limited conditions.

Clostridium thermoaceticum ATCC 39073 converted vanillate to catechol. Although carboxylated aromatic compounds which did not contain methoxyl groups were not by themselves growth supportive, protocatechuate and p-hydroxybenzoate (nonmethoxylated aromatic compounds) were converted to catechol and phenol, respectively, during carbon monoxide-dependent growth. Syringate is not subject to decarboxylation by C. thermoaceticum (Z. Wu, S. L. Daniel, and H. L. Drake, J. Bacteriol. 170:5705-5708, 1988), and sustained growth at the expense of syringate-derived methoxyl groups was dependent on supplemental CO2. In contrast, vanillate was growth supportive in the absence of supplemental CO2, and 14CO2 was the major 14C-labeled product during [carboxyl-14C]vanillate-dependent growth. Furthermore, the decarboxylation of protocatechuate and p-hydroxybenzoate supported methanol- and 1,2,3-trimethoxybenzene-dependent growth (CO2 is required for growth at the expense of these substrates) when supplemental CO2 was depleted from the growth medium, and the decarboxylation of protocatechuate was concomitant with improved cell yields of methanol cultures. These findings demonstrate that (i) C. thermoaceticum is competent in the decarboxylation of certain aromatic compounds and (ii) under certain conditions, decarboxylation may be integrated to the flow of carbon and energy during acetogenesis.

Biotransformation↗
PubMed1990

Characterization of the H2- and CO-dependent chemolithotrophic potentials of the acetogens Clostridium thermoaceticum and Acetogenium kivui.

Strains of Clostridium thermoaceticum were tested for H2- and CO-dependent growth in a defined medium containing metals, minerals, vitamins, cysteine-sulfide, CO2-bicarbonate, and H2 or CO. Ten of the thirteen strains tested grew at the expense of H2 and CO, and C. thermoaceticum ATCC 39073 was chosen for further study. The doubling times for H2- and CO-dependent growth under chemolithotrophic conditions (the defined medium with nicotinic acid as sole essential vitamin and sulfide as sole reducer) were 25 and 10 h, respectively. Product stiochiometries for chemolithotrophic cultures approximated: 4.1H2 + 2.4CO2----CH3COOH + 0.1 cell C + 0.3 unrecovered C and 6.8CO----CH3COOH + 3.5CO2 + 0.4 cell C + 0.9 unrecovered C. H2-dependent growth produced significantly higher acetate concentrations per unit of biomass synthesized than did CO- or glucose-dependent growth. In contrast, the doubling time for H2-dependent growth under chemolithotrophic conditions (the defined medium without vitamins and sulfide as sole reducer) by Acetogenium kivui ATCC 33488 was 2.7 h; as a sole energy source, CO was not growth supportive for A. kivui. The YH2 values for A. kivui and C. thermoaceticum were 0.91 and 0.46 g of cell dry weight per mol of H2 consumed, respectively; the YCO value for C. thermoaceticum was 1.28 g of cell dry weight per mol of CO consumed. The specific activities of hydrogenase and CO dehydrogenase in both acetogens were influenced by the energy source utilized for growth and were significantly lower in C. thermoaceticum than in A. kivui. With extracts of H2-cultivated cells and benzyl viologen as electron acceptor, the Vmax values for hydrogenase from C. thermoaceticum and A. kivui were 155.7 and 1,670 micromoles of H2 oxidized per min mg of protein, respectively; the Vmax values for CO dehydrogenase from C. thermoaceticum and A. kivui were 90.6 and 2,973 micromoles of CO oxidized per min per mg of protein, respectively.

Acetates↗
PubMed1989

1,25-Dihydroxyvitamin D3 regulation of c-myc protooncogene transcription. Possible involvement of protein kinase C.

1,25-Dihydroxyvitamin D3 (1,25-(OH)2D3) regulates the expression of c-myc protooncogene in HL-60 promyelocytic leukemia cells (Reitzma, P. H., Rothberg, P. G., Astrin, S. M., Trial, J., Barshavit, Z., Hall, A., Teitelbaum, S. U., and Kahn, A. J. (1983) Nature 306, 492-494). The regulation of c-myc expression occurs at least in part at the transcriptional level (Simpson, R. U., Hsu, T., Begley, D. A., Mitchell, B. S., and Alizadeh, B. N. (1987) J. Biol. Chem. 262, 4104-4108). Also, 1,25-(OH)2D3 stimulates an increase in protein kinase C (PKC) levels and inhibitors of PKC block 1,25-(OH)2D3-induced differentiation of HL-60 cells (Martell, R. E., Simpson, R. U., and Taylor, J. M. (1987) J. Biol. Chem. 262, 5570-5575). In this report we demonstrated that sphinganine, an inhibitor of PKC that is mechanistically and structurally distinct from 1-(5-isoquinoline sulfonyl)-2-methylpiperazine-HCl (H-7), also blocks 1,25-(OH)2D3 induction of HL-60 cell differentiation. The effect of inhibitors of PKC on 1,25-(OH)2D3 regulation of c-myc transcription was examined. H-7 (18 microM) and sphinganine (3 and 6 microM) blunted 1,25-(OH)2D3-induced reduction of c-myc transcription as assessed by nuclear run-off assays. We showed that c-myc/beta-actin ratios (cpm/cpm, % of control mean +/- S.E.) were as follows: ethanol control, 100 +/- 14%; 50 nM 1,25-(OH)2D3, 17 +/- 5%; 50 nM 1,25-(OH)2D3 and 6 microM H-7, 13 +/- 6%; 50 nM 1,25-(OH)2D3 and 18 microM H-7, 53 +/- 6% 50 nM 1,25-(OH)2D3 and 18 microM N-[2-guanidinoethyl]-5-isoquinoline sulfonamide (HA-1004), 10 +/- 8%; 50 nM 1,25-(OH)2D3 and 6 microM sphinganine, 49 +/- 8%. No significant differences in c-myc transcription between control, 18 microM H-7, 18 microM HA-1004, and 3 or 6 microM sphinganine-treated cells were observed. The block in c-myc transcription was beyond exon 1, and regulation of exon 1 transcription by 1,25-(OH)2D3 was not detected. Furthermore, we demonstrated that expression of markers for HL-60 cell differentiation was more rapidly induced by 25 nM 12-O-tetradecanoylphorbol-13-acetate than 50 nM 1,25-(OH)2D3, suggesting that direct activation of PKC by phorbol esters may make processes required for 1,25-(OH)2D3 induction of differentiation unnecessary. In summary, these data suggest that a primary effect of 1,25-(OH)2D3 on HL-60 cells is to regulate PKC levels, and regulation of c-myc transcription by 1,25-(OH)2D3 is a result of this action.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1989

Copper and the ACE1 regulatory protein reversibly induce yeast metallothionein gene transcription in a mouse extract.

We describe a cell-free system in which the transcription of the yeast metallothionein gene is inducible by the addition of metal ions plus a specific regulatory protein. Efficient transcription requires the complete yeast ACE1 metalloregulatory protein, including both its DNA-binding and transactivation domains; a mouse nuclear extract providing RNA polymerase and general transcription factors; a template containing the ACE1 binding site; and Cu(I). Because the binding of ACE1 to DNA is dependent on Cu, it is possible to inhibit transcription by the use of Cu-complexing agents such as CN-. We have used this specific inhibition to show that the ACE1 regulatory protein is required for the maintenance as well as the formation of a functional preinitiation complex. The ability to reversibly induce yeast metallothionein gene transcription in vitro provides a powerful system for determining the molecular mechanism of a simple eukaryotic regulatory circuit.

Animals↗
PubMed1989

Automated biochemical identification of bacterial fish pathogens using the Abbott Quantum II.

The Quantum II, originally designed by Abbott Diagnostics for automated rapid identification of members of Enterobacteriaceae, was adapted for the identification of bacterial fish pathogens. The instrument operates as a spectrophotometer at a wavelength of 492.600 nm. A sample cartridge containing 20 inoculated biochemical chambers is inserted in the path of the analyzing beam. Reactions are converted into a 7-digit octal biocode, relayed via a sensor to the memory module, and compared to biocodes preprogrammed in the memory. An identification is then printed. Presently, the Quantum II is capable of identifying human strains of Aeromonas hydrophila and Edwardsiella tarda. This study was initiated to determine the feasibility of expanding the use of the Quantum II to include identification of bacterial fish pathogens. Ten to 50 isolates of Edwardsiella ictaluri, Serratia liquefaciens, Yersinia ruckeri, Aeromonas hydrophila, typical Aeromonas salmonicida, and atypical Aeromonas salmonicida were utilized to determine optimal incubation conditions, relative stability of the biochemicals, and ability to obtain consistent biocode numbers. After sorting the octal biocodes from the 169 isolates into groupings using a cluster analysis technique, it was shown by a Chi-square goodness of fit test that isolates of a given species were sorted into the same cluster group at a frequency of at least 99%. Results of this study illustrate the usefulness of the Quantum II BID system for the identification of bacterial fish pathogens not contained within the system's memory module.

Animals↗
PubMed1989

Recording of penile tumescence and rigidity in impotence.

A new method of continuous and simultaneous recording of nocturnal penile tumescence and rigidity was used in 70 men (38 normal and 32 impotent). The RigiScan test provided several findings concerning nocturnal penile erection in impotent men. Of 32 impotent men, 9(28.1%) had normal patterns, 2(6.3%) had normal penile tumescence without rigidity, and 6(18.7%) had a dissociation of rigidity between the tip and base of the penis. Of 9 patients (28.1%) with a shortened duration of erection in the RigiScan test, 6 had undergone cavernosography, and all were proved to have venous incompetence. Low amplitude of rigidity (6.3%) and flat tracing (12.5%) were also seen. The RigiScan test is superior to other available methods of assessing erectile response. It produces an objective, accurate record of rigidity as well as tumescence, thus aiding in differentiating psychogenic from organic impotence.

Adolescent↗