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T T Wu

Publications and source records attributed to T T Wu.

At least 91 records · Page 5Linked to original sources
PubMed1996

Evidence that two latency-associated transcripts of herpes simplex virus type 1 are nonlinear.

The latency-associated transcripts (LATs) of herpes simplex virus type 1 (HSV-1) are the only viral gene products that accumulate to abundant levels in latently infected cells. Others have reported species of 2.0, 1.50, and 1.45 kb; only the 2.0-kb species is seen in productively infected cells, and there is evidence that it behaves as an intron. We examined the LATs both in trigeminal ganglia of latently infected mice and in productively infected cultures of monkey CV-1 cells. After glyoxalation, RNA was subjected to high-resolution agarose gel electrophoresis and Northern (RNA) analysis, a procedure capable of resolving linear and nonlinear RNA species. Under these conditions, we resolved the 2.0-kb LAT into two species; the slower species was much more abundant and had a mobility significantly slower than expected for a linear RNA. To test the hypothesis that this RNA was in fact nonlinear, we used partial hydrolysis by sodium carbonate and oligonucleotide-directed RNase H digestion. These procedures changed the mobility of the slower species into that of the faster species. Similarly, the mobility of the 1.50-kb LAT, which was much more abundant than the 1.45-kb LAT, was changed by these procedures to that of the 1.45-kb LAT. Our data show that the two major LAT species are nonlinear, and they support an interpretation of stable lariat structures.

Animals↗
PubMed1996

Functional and urodynamic characteristics of Camey II ileal neobladder.

The object of this study is to evaluate the functional and urodynamic characteristics of 16 patients who had undergone the Camey II orthotopic bladder replacement after radical cystoprostatectomy. Questionnaires regarding the voiding pattern and urinary continence were answered by 14 patients. Daytime continence was achieved in 13 of 14 patients (93%) at a mean interval of 3 months postoperatively. Eight patients (62%) attained their nighttime continence at an average interval of 10 months. Six of these 8 patients had to void to keep dry at night. Urodynamic studies were completed in 13 patients at an average of 11 months (range 6-23) postoperatively. Patients with nighttime continence had a significantly higher cystometric filling capacity (323 vs. 196 ml, p < 0.001), lower basal pouch pressure (24.5 vs. 35.2 cm water, p = 0.04), lower maximal voiding pressure (62.1 vs. 88.0 cm water, p = 0.01) and higher maximal urethral closure pressure (65.5 vs. 44.0 cm water, p = 0.03). There is no significant difference among the parameters of the age at operation, the amount of residual urine and the functional profile length between these two groups of patients. The antireflux procedure was successful in 11 of 12 patients (92%). We conclude that the Camey II operation could fulfill all the criteria of ideal bladder substitution with adequate volume, low resting pressure, satisfactory continence rate and antireflux characteristic.

Cystectomy↗
PubMed1996

K-ras-2 and p53 genotyping of intestinal-type adenocarcinoma of the nasal cavity and paranasal sinuses.

Intestinal-type adenocarcinoma (ITAC) of the nasal cavity and paranasal sinuses is an uncommon neoplasm manifesting a variety of histologic growth patterns, most of which are reminiscent of colorectal adenocarcinoma. To determine whether this morphologic resemblance is mirrored in equivalent genetic alterations, a series of ITAC was genotyped using archival, formalin-fixed tissues for point mutational damage in K-ras-2 oncogene and p53 tumor suppressor gene, forms of DNA damage frequently found in colorectal adenocarcinoma. In contrast to colorectal adenocarcinoma, which demonstrates K-ras-2 mutation in about 50% of cases, ITAC showed no evidence of K-ras-2 mutation. p53 mutations were present in 18% of ITAC (2 of 11) compared to more than 75% incidence of p53 mutation seen in colorectal adenocarcinoma. Fifty-eight percent of ITAC demonstrated scattered positive p53 immunohistochemical nuclear staining, but no mutations were identified in exon-5 through exon-8 by genotyping. There was no specific p53 alterations with respect to histologic subtype of ITAC. Although ITAC and colorectal adenocarcinoma are histologically similar, there are important differences at the genetic level based on expression of K-ras-2 and p53 abnormalities.

Adenocarcinoma↗
PubMed1996

Inverted papilloma of the urinary bladder.

BACKGROUND: Inverted papillomas are rare in the lower urinary tract. It is a histologically benign tumor with low grade malignant potential. Association with transitional cell carcinoma has also been reported. METHODS: Eight cases of inverted papilloma of the urinary bladder were diagnosed at this hospital between November 1990 and May 1994. There were one female and seven males with an average age of 63.5 years. We analyze their clinical presentations, histological findings and the outcome of treatments. RESULTS: Four patients presented with hematuria, and four with obstructive symptoms. Four were solid pedunculated tumors; three were papillary pedunculated; and one was a papillary sessile tumor. All tumors were solitary with four located in the bladder neck, two in the lateral wall, one in the interureteral ridge, and one in the trigonal area. A 77-year-old man whose tumor coexisted with an infiltrative transitional cell carcinoma was treated with partial cystectomy. The other seven patients were treated by transurethral resection. All the tumors were of the trabecular type and three of them (37.5%) harbored calcium oxalate crystals. There was no evidence of recurrence in a median follow-up of 18 months. CONCLUSIONS: Inverted papillomas of urinary bladder are benign tumors, which can be treated successfully by transurethral resection and fulguration of tumor bed. However, precautionary studies are necessary to exclude the coexistence of malignancy and annual follow-up with cystourethroscopy is mandatory.

Adult↗
PubMed1995

A dumbbell spinal lipoma presenting as a neck mass: CT and MR demonstration.

A case of histologically confirmed spinal lipoma without associated spinal dysraphism is presented. This tumor appeared lobulated, extending through an enlarged neuroforamen to form a so-called dumbbell tumor. In a review of the literature, there were found to be only four case reports of a dumbbell spinal lipoma. Our case was unique in that it manifested as a neck mass without neurological deficits. The fatty nature of the tumor allowed easy detection by computed tomography (CT), as well as by magnetic resonance (MR) imaging. MR is judged to be superior to CT for preoperative planning by virtue of its superb intraspinal resolution and multiplanar capability, and should be the procedure of choice for evaluating spinal lipomas.

Child, Preschool↗
PubMed1995

Hepatitis delta virus mutant: effect on RNA editing.

During the replication cycle of hepatitis delta virus (HDV), RNA editing occurs at position 1012 on the 1679-nucleotide RNA genome. This changes an A to G in the amber termination codon, UAG, of the small form of the delta antigen (delta Ag). The resultant UGG codon, tryptophan, allows the translation of a larger form of the delta Ag with a 19-amino-acid C-terminal extension. Using HDV cDNA-transfected cells, we examined the editing potential of HDV RNA mutated from G to A at 1011 on the antigenome, adjacent to normal editing site at 1012. Four procedures were used to study not only the editing of the A at 1012, but also that of the new A at 1011: (i) nucleotide sequencing, (ii) a PCR-based RNA-editing assay, (iii) immunoblot assays, and (iv) immunofluorescence. Five findings are reported. (i) Even after the mutation at 1011, editing still occurred at 1012. (ii) Site 1011 itself now acted as a novel RNA-editing site. (iii) Sites 1011 and 1012 were edited independently. (iv) At later times, both sites became edited, thereby allowing the synthesis of the large form of the delta Ag (delta Ag-L). (v) Via immunofluorescence, such double editing became apparent as a stochastic event, in that groups of cells arose in which the changes had taken place. Evaluation of these findings and of those from previous studies of the stability of the HDV genomic sequence (H.J. Netter et al., J. Virol. 69:1687-1692, 1995) supports both the recent reevaluation of HDV RNA editing as occurring on antigenomic RNA (Casey and Gerin, personal communication) and the interpretation that editing occurs via the RNA-modifying enzyme known as DRADA.

Amino Acid Sequence↗
PubMed1995

Nucleotide sequence stability of the genome of hepatitis delta virus.

Cultured cells were cotransfected with a fully sequenced 1,679-base cDNA clone of human hepatitis delta virus (HDV) RNA genome and a cDNA for the genome of woodchuck hepatitis virus (WHV). The HDV particles released were able to infect a woodchuck that was chronically infected with WHV. The HDV so produced was passaged a total of six times in woodchucks in order to determine the stability of the HDV nucleotide sequence. During a final chronic infection with such virus, liver RNA was extracted, and the HDV nucleotide sequence for the 352-base region, positions 905 to 1256, was obtained. By means of PCR, we obtained double-stranded cDNA both for direct sequencing and also for molecular cloning followed by sequencing. By direct sequencing, we found that a consensus sequence existed and was identical to the original sequence. From the sequences of 31 clones, we found 32% (10 of 31) to be identical to the original single nucleotide sequence. For the remainder, there were neither insertions nor deletions but there was a small number of single-nucleotide changes. These changes were predominantly transitions rather than transversions. Furthermore, the transitions were largely of just two types, uridine to cytidine and adenosine to guanosine. Of the 40 changes detected on HDV, 35% (14 of 40) occurred within an eight-nucleotide region that included position 1012, previously shown to be a site of RNA editing. These findings may have significant implications regarding both the stability of the HDV RNA genome and the mechanism of RNA editing.

Animals↗
PubMed1995

Primary small cell carcinoma of the urinary bladder: report of a case.

A 66-year-old male presented with diffuse abdominal pain and microscopic hematuria characteristic of perirenal urinoma formation. After a biopsy, he was diagnosed with small cell carcinoma of the urinary bladder. The patient was treated by radical cystoprostatectomy with orthotopic bladder replacement using the Camey II procedure. Daytime urinary continence was achieved 6 months after surgery. The patient died of carcinomatosis 15 months after diagnosis.

Aged↗
PubMed1995

The efficacy of finasteride in the treatment of symptomatic benign prostatic hyperplasia.

BACKGROUND: Benign prostatic hyperplasia is a common disease in aged men; the standard therapy has surgery. However, candidates for prostatectomy are commonly aged with high surgical risks, for whom medical treatment is preferable choice. METHODS: From February 1994 to April 1994, in total 25 men with symptomatic benign prostatic hyperplasia were enrolled into this prospective study. All patients were treated with finasteride 5 mg per day for six months. RESULTS: Seven patients withdrew from the study, one for exasperated symptoms, three for personal reasons and three patients were excluded because of poor compliance. In total 18 patients completed the six-month therapy and surveillance. The AUA symptom scores improved on average by 6.3 points; prostatic adenoma volume reduced from baseline by 17%, and the serum prostate specific antigen (PSA) level decreased by 35%. No improvement of the rate of urinary flow was noted. Sixty-one per cent of patients had more than 50% improvement in subjective symptom scores, 28 per cent of men showed per cent or greater decrease in prostate volume. However, only one patient showed an increase of 3 mL/s or more in maximal flow rate at the end of study. Six patients reported adverse sexual experiences (impotence in 3, decreased rigidity in 1, and decreased libido in 2) and one had GI upset. CONCLUSIONS: A subset of patients with benign prostatic hyperplasia may benefit from treatment with finasteride. Although most patients experienced subjective improvement, increase in maximal flow rate is unsatisfactory in this preliminary report.

5-alpha Reductase Inhibitors↗
PubMed1994

RNA editing in the replication cycle of human hepatitis delta virus.

For some time it has been known that the RNA genome of human hepatitis delta virus (HDV) undergoes a specific RNA editing event. This review describes the editing phenomenon and its potential biological significance, and evaluates the data regarding the mechanism involved, including the possible relationship to other RNA editing phenomena.

Hepatitis Delta Virus↗
PubMed1994

The role of C-reactive protein and erythrocyte sedimentation rate in the diagnosis of infected hydronephrosis and pyonephrosis.

Serum C-reactive protein levels and erythrocyte sedimentation rates were prospectively evaluated in 38 patients with dilated pyelocaliceal systems in an attempt to distinguish simple hydronephrosis from infected hydronephrosis and pyonephrosis. The clinical presentations of infected hydronephrosis and pyonephrosis were extremely variable, ranging from no constitutional complaints to urosepsis. Renal sonography detected only 6 of 16 patients with pyonephrosis (specificity 96%, sensitivity 38%, accuracy 72.5%). Using a cutoff value of 3.0 mg./dl. for C-reactive protein and 100 mm. per hour for erythrocyte sedimentation rate, the diagnostic accuracy of detecting infected hydronephrosis and pyonephrosis increased to 97%, with a specificity of 89% and sensitivity of 100%. Based on our experience, we believe that the serum C-reactive protein and erythrocyte sedimentation rate levels can be used as screening tests to distinguish pyonephrosis and infected hydronephrosis from simple, uncomplicated hydronephrosis.

Blood Sedimentation↗
PubMed1994

Morphological change in the urothelium after electrohydraulic versus pulsed dye laser lithotripsy.

OBJECTIVE: To observe morphological changes in the urothelium after exposure to laser beam and electrohydraulic spark. MATERIALS AND METHODS: The pulse dye laser lithotripter (MDL-2, Candela Corporation, Boston, USA) and the electrohydraulic lithotripter (AEH-2, Circon ACMI Corporation Stamford, USA) were used directly on the bladder mucosa in six pigs. Immediately after treatment, the bladder mucosa was prepared for light microscopic and scanning electron microscopic examination. RESULTS: Both electrohydraulic spark and laser beam caused mucosal denudation, submucosal swelling and haemorrhage. There was a positive correlation between the degree of urothelial damage and the power and pulse numbers applied. CONCLUSION: Direct contact of the urothelium in patients treated with laser beam or electrohydraulic spark should be avoided.

Animals↗
PubMed1994

Prediction of lymphatic spreading in prostatic cancer by prostate-specific antigen and Gleason's score.

A total of 58 patients have undergone bilateral pelvic lymphadenectomy as a staging procedure for clinically localized adenocarcinoma of the prostate. Of these, 19 patients (33%) had pelvic lymph node involvement. When a cutoff value of 50 ng/ml was used, the preoperative prostate-specific antigen (PSA) value had a positive predictive value of 57% for pelvic lymph node metastasis. Of the patients with PSA < 20 ng/ml, only 1 (4%) had evidence of lymph node metastasis. None of the patients with well-differentiated tumor (Gleason 2-4) had lymphatic spreading. In contrast, 82% of patients with poorly differentiated tumor (Gleason 8-10) had positive pelvic lymph nodes. Those patients with high PSA (> or = 20 ng/ml) and high Gleason's score (> or = 8) had the highest incidence of nodal extension (90%).

Aged↗
PubMed1994

Percutaneous nephroscopy in the diagnosis of renal pelvic filling defect: a report of two cases.

The major differential diagnosis of a radiolucent filling defect within the renal pelvis is among tumor, blood clot and radiolucent stone. In some cases, it is difficult to distinguish tumor from other benign lesions by imaging study. Two patients with renal pelvic filling defect were diagnosed by percutaneous nephroscopy, using the 27 Fr. rigid nephroscope (Olympus, Tokyo, Japan). Both patients got conclusive diagnosis by percutaneous nephroscopy; the morbidity was extremely minimal. The diagnostic percutaneous nephroscopy was a safe and effective procedure with minimal morbidity. For those patients without a conclusive diagnosis in noninvasive procedures, the percutaneous nephroscopy could be an alternative for flexible ureteroscopy, especially for the extremely tortuous ureters.

Aged↗