Percent free prostate-specific antigen for first-time prostate biopsy.
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Biomedical subjects
Publications and source records attributed to C T Lee.
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OBJECTIVES: To compare the radiographic size with the pathologic size of renal tumors to determine whether these two measurements vary significantly and to evaluate whether any differences in tumor size could have an impact on the decisions regarding partial nephrectomy. METHODS: In 87 renal tumors excised by partial nephrectomy, the maximum transaxial tumor size on computed tomography (CT) was compared with its corresponding pathologic transverse size. Tumors were locally excised after vascular occlusion and hypothermia. The average size of the tumors selected for partial nephrectomy by preoperative CT scan was 3.4 cm (range 1.9 to 9.3). The difference between the CT size and pathologic size was correlated with the histologic type of the renal tumors. RESULTS: Of the 87 tumors, 52 (60%) were classified as clear cell carcinoma and 35 (40%) as other histologic types (papillary, chromophobe, oncocytoma, and angiomyolipoma). Clear cell carcinomas decreased an average of 0.97 cm versus 0.39 cm for the other tumor types. Of 62 tumors greater than 3 cm on CT, 43 averaged 0.87 cm smaller at pathologic evaluation (36 clear cell and 7 other types) and 19 showed no significant (less than 0.5 cm) decrease in size (2 clear cell and 17 other histologic types). Of 30 tumors greater than 4 cm on CT, 22 clear cell carcinomas shrank more than 1 cm and 8 tumors displaying other histologic features showed no decrease in size. CONCLUSIONS: For renal tumors measuring greater than 4 cm, a decrease in tumor size may help facilitate partial nephrectomy, especially for clear cell carcinomas that do not extensively involve major vascular structures or the collecting system.
Orphan nuclear receptors are members of the nuclear receptor superfamily of ligand-activated transcription factors for which ligands and functions have not been identified. Since the cloning of the original orphans, ligands have been identified for several orphan receptors that heterodimerize with the retinoid X receptor and are no longer classified as orphan receptors. Considering the central role that nuclear receptors play in differentiation, development, metabolic regulation, homeostasis and disease, it is crucial that we understand the roles of the remaining orphans. However, the identification of ligands for those orphans that form homodimers has proven more difficult. Thus, to gain greater insight into the functions of orphan receptors, gene targeting has been used to knock out these factors and study mouse development in their absence. Here we will review the progress made in understanding the roles of the orphans GCNF and the COUP-TFs with the use of gene knockouts.
Bilateral femoral neck fractures are rarely reported in patients with end-stage renal disease before chronic dialysis. We report on a 39-year-old woman with neglected bilateral femoral neck fractures, who presented with severe uremic complications prior to chronic dialysis. Three years before admission, she had injured herself in a trivial slip with subsequent bilateral hip pain. She had progressively waddled since then. Pelvic X-ray taken after admission revealed bilateral femoral neck fractures. Bilateral hip hemiarthroplasties were subsequently performed. Displaced femoral neck fractures were found intraoperatively. Pathologic findings and results of examinations supported the coexistence of osteoporosis and high turnover renal osteodystrophy, rendering this woman at high risk of bilateral femoral neck fractures. Therefore, preventing a simple fall or trivial accident and treating renal osteodystrophy and osteoporosis are paramount in patients with chronic renal failure even before the start of dialysis therapy. We also emphasize the need to seek any possible underlying metabolic bone disease once a patient presents with unusual fractures.
The designed peptide (denoted 20-mer, sequence VFITS(D)PGKTYTEV(D)PGOKILQ) has been shown to form a three-strand antiparallel beta-sheet. It is generally believed that the (D)Pro-Gly segment has the propensity to adopt a type II' beta-turn, thereby promoting the formation of this beta-sheet. Here, we replaced (D)Pro-Gly with Asp-Gly, which should favor a type I' turn, to examine the influence of different type of turns on the stability of the beta-sheet. Contrary to our expectation, the mutant peptide, denoted P6D, forms a five-residue type I turn plus a beta-bulge between the first two strands due to a one amino-acid frameshift in the hydrogen bonding network and side-chain inversion of the first beta-strand. In contrast, the same kind of substitution at (D)Pro-14 in the double mutant, denoted P6DP14D, does not yield the same effect. These observations suggest that the SDGK sequence disfavors the type I' conformation while the VDGO sequence favors a type I' turn, and that the frameshift in the first strand provides a way for the peptide to accommodate a disfavored turn sequence by protruding a bulge in the formation of the beta-hairpin. Thus, different types of turns can affect the stability of a beta-structure.
Naturally occurring hepatitis C virus (HCV) infection has long been thought to induce a weak immunity which is insufficient to protect an individual from subsequent infections and has cast doubt on the ability to develop effective vaccines. A series of intrahepatic genetic inoculations (IHGI) with type 1a HCV RNA were performed in a chimpanzee to determine whether a form of genetic immunization might stimulate protective immunity. We demonstrate that the chimpanzee not only developed protective immunity to the homologous type 1a RNA after rechallenge by IHGI but was also protected from chronic HCV infection after sequential rechallenge with 100 50% chimpanzee infectious doses of a heterologous type 1a (H77) and 1b (HC-J4) whole-virus inoculum. These results offer encouragement to pursue the development of HCV vaccines.
The anti-inflammatory effect of acetylsalicylic acid (ASA) has been thought to be secondary to the inhibition of prostaglandin synthesis. Because doses of ASA necessary to treat chronic inflammatory diseases are much higher than those needed to inhibit prostaglandin synthesis, a prostaglandin-independent pathway has been emerging as the new anti-inflammatory mechanism of ASA. Here, we examined the effect of ASA on the interleukin (IL)-1 beta- and tumor necrosis factor (TNF)-alpha-induced proinflammatory cytokine expression and evaluated whether this effect is closely linked to the nuclear factor (NF)-kappa B/I kappa B-alpha pathway. A high dose of ASA blocked IL-1 beta- and TNF-alpha-induced TNF-alpha and IL-8 expression, respectively. ASA inhibited TNF-alpha-induced activation of NF-kappa B by preventing phosphorylation and subsequent degradation of I kappa B-alpha in a prostanoid-independent manner. TNF-alpha-induced activation of I kappa B kinase was also suppressed by ASA pretreatment. These observations suggest that the anti-inflammatory effect of ASA in lung epithelial cells may be due to suppression of I kappa B kinase activity, which thereby inhibits subsequent phosphorylation and degradation of I kappa B-alpha, activation of NF-kappa B, and proinflammatory cytokine expression in lung epithelial cells.
Aortobronchial fistula (ABF) (aortopulmonary fistula) may cause a massive fatal hemoptysis. We have recently seen a patient with ABF presenting with recurrent, massive hemoptysis. She was successfully treated with an endovascular stent graft. The endovascular stent graft may provide an alternative treatment of in patients considered to be poor surgical candidates.
This study was conducted to evaluate the effect of acute sleep deprivation on cognitive functions. A total of 18 healthy right handed males were deprived of sleep for 24 hours. Luria-Nebraska Neuropsychological Battery and calculation & digit-span subtest of K-WAIS were administered before and after sleep deprivation in order to examine the changes of cognitive functions. There were no differences in freedom from distractibility, tacile function, visual function, reading, writing, arithmetic and intellectual process function. However, the cognitive functions such as motor, rhythm, receptive & expressive speech, memory and complex verbal arithmetic function were decreased after sleep deprivation. All of these functions are known to be related to the right anterior hemisphere. For localization scales, the scores of right frontal and right temporal dysfunction scale were increased after sleep deprivation. These results indicate that sleep deprivation has a negative effect on cognitive functions, especially those associated with right anterior hemisphere or subcortical areas.
High frequency of p16 alteration and high local recurrence rate of bladder cancer make this cancer an ideal target for p16 gene therapy. However, a low transduction rate of p16 via adenoviral vector causes an inconsistent result. In this study, we have tested adenovirus-p16 in several bladder cancer cell lines and investigated a way of improving the low transduction rate. Adenovirus-p16 showed a strong antitumor effect on bladder cancer cell lines (253J and T24) with strong Coxackie-adenoviral receptor (CAR) expression but little antitumor effect on bladder cancer cell lines (J82 and HT1376) with little CAR expression. In this study, we suggest a simple way of overcoming the differential effects of the adenovirus. The addition of butyrate to media was found to increase the transduction rate of adenovirus remarkably and increase the antitumor effect of adenovirus-p16 in bladder cancer cell lines with little CAR expression. Butyrate effects were related with increased CAR expression on the cell surface as well as increased transgene expression from adenoviral vector. From these observations, application of adenovirus-p16 gene therapy with butyrate can overcome the obstacle of low gene transfer and enhance the antitumor effect of adenovirus-p16 in bladder cancer.
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BACKGROUND: Duplication of the renal pelvis and ureter constitutes the most common anomalies of the upper urinary tract. Most patients are asymptomatic and don't need treatment. However, the associated anomaly and acquired renal disease may cause morbidity and mortality. The aim of this study was to investigate the prevalence of duplex kidney in sonographic examinations and the predictive capability of this method. An analysis of patients with urography-confirmed duplication anomaly was also performed. METHODS: During a period of 9 year (from 1988 to 1996), sonographic examination records of 19,287 patients were reviewed. Patients with a diagnosis of duplex kidney were enrolled. Their clinical characteristics and radiological images were recorded and evaluated. RESULTS: One hundred and sixty-three patients were found by sonography to have duplex kidney, for an prevalence of 0.85%. Urography studies were done on 64 (39.2%) patients, and 42 patients were proven to have duplex kidney. The positive predictive rate of sonography was 65.6%. Eighty percent of patients with duplex kidney had associated ureteral duplication. No associated anomalies were found. Four patients had urolithiasis, and 3 patients had recurrent urinary tract infection. One patient had coexisting uroepithelial malignancy, and 1 patient had refractory gross hematuria. CONCLUSIONS: Duplex kidney is an uncommon finding during adult sonographic examinations. The sensitivity and specificity of sonography in identifying this anomaly are controversial. An experienced hand with good knowledge of the anomaly and its sonographic signs is helpful in more accurately diagnosing this anomaly.
In diverse cell types, NF-kappaB transcription factors have been shown to have a role in regulating the apoptotic program, either as essential for the induction of apoptosis or, perhaps more commonly, as blockers of apoptosis. We investigated the role of NF-kappaB activation in the TNF-alpha-mediated apoptosis in lung cancer cells. TNF-alpha-resistant NCI-H157 cells became sensitized to TNF-alpha by prior treatment with cycloheximide, suggesting the presence of newly synthesized antiapoptotic protein(s). We next evaluated whether the transcription of antiapoptotic protein(s) depends on the activation of NF-kappaB. NF-kappaB activation was blocked by either adenovirus-mediated overexpression of IkappaBalpha superrepressor or pretreatment with proteasome inhibitor, MG132. Both methods of blocking NF-kappaB activation enhanced TNF-alpha-induced apoptosis in NCI-H157 cells. These results suggest that NF-kappaB activation confers resistance to TNF-alpha-mediated apoptosis in lung cancer cells.
Heat shock protein (HSP) induction confers protection against diverse forms of cellular and tissue injury. However, the mechanism by which HSP exerts cytoprotective effects is unclear. Because HSP induction inhibits genetic expression of pro-inflammatory cytokines, the transcription of which is dependent on NF-kappa B activation, we explored the relationship between the anti-inflammatory effect of HSP induction and the NF-kappa B/I kappa B alpha pathway. Both HS and sodium arsenite treatment increased HSP70 expression time dependently at mRNA and protein levels. Prior induction of HSP suppressed cytokine-induced IL-8 and TNF-alpha expression at both mRNA and protein levels. Although HSP induction did not affect total cellular expression of NF-kappa B, TNF-alpha-induced increase in NF-kappa B-DNA binding activity and nuclear translocation of the p65 subunit of NF-kappa B were inhibited by prior HSP induction, suggesting that activation of NF-kappa B was blocked. Cytokine-induced I kappa B alpha phosphorylation and its degradation were blocked in HSP-induced cells. Immune complex kinase assays demonstrated that TNF-alpha induced increase in I kappa B kinase activity was suppressed by prior HSP induction. These results suggest that the anti-inflammatory effect of HSP induction in respiratory epithelial cells is related to stabilization of I kappa B alpha, possibly through the prevention of I kappa B kinase activation, which thereby inhibits activation of NF-kappa B.
Hyponatremia is a clinical manifestation of a wide variety of diseases, some of which have high mortality rates. To assess the prevalence, cause, and prognosis of hyponatremia encountered in the emergency department, we conducted a prospective study at a major hospital in southern Taiwan. We included all adult internal medicine patients treated in the emergency department during a 2-month period. Hyponatremia was defined as a serum sodium level below 134 mEq/L, and cases patients were followed till being discharged. Among the 3,784 patients included, 166 case patients were identified. Most (65%) case patients were hypovolemic, and the overall mortality rate was 17.9%. The mortality rate increased as the sodium level decreased, but was not related to gender, age, cause, or serum potassium level. When 21 hyperglycemic patients whose serum sodium levels went beyond 134 mEq/L after the adjustment for blood sugar levels were excluded, the prevalence of true hyponatremia was 3.83%. The most common underlying diseases were those of the gastrointestinal system. It is concluded that hyponatremia is a common condition encountered in the emergency department. The mortality is correlated with the serum sodium level, and adjustment of the level is required in hyperglycemic patients to make a correct diagnosis. Unlike the cases in some other clinical settings, almost all cases of hyponatremia encountered in the emergency department were not iatrogenic and had recognizable underlying diseases. Therefore, more effort is generally required to identify the cause of hyponatremia cases in the emergency department.
Pollen flow and population genetic structure among 30 potentially flowering individuals of Neobalanocarpus heimii, a tropical emergent tree, were investigated in a lowland tropical rainforest of Malaysia using microsatellite polymorphism. The 248 offspring in the vicinity of five reproductive trees of the 30 potentially flowering trees were used in paternity analysis for pollen-flow study. Four primer pairs, developed in different species of dipterocarps, were adopted to detect microsatellite polymorphism. Based upon microsatellite polymorphism, pollen flow and seed migration were detected. Pollen-flow events of more than 400 m were observed directly, based on paternity analysis in the study plot. The estimated average mating distance of the five reproductive trees was 524 m. This result suggests that reproduction of this species is mediated by a long-distance pollinator. The haplotypes of some offspring were not compatible with the nearest reproductive tree. Thus, the results suggest that some seeds are dispersed by a seed dispersal vector. Investigation of genetic structure showed significant and negative correlation of genetic relatedness and spatial distances between the 30 potentially flowering trees, but this correlation was weak. We suggest that long-distance gene flow and seed migration are responsible for the poorly developed genetic structure of this species.
A total of 204 nonrepetitive isolates of group A streptococci (GAS), including 107 randomly collected between 1992 and 1995 and 66 and 31 consecutively collected in 1997 and 1998, respectively, from a university hospital in southern Taiwan were examined to determine the prevalence and mechanisms of erythromycin resistance among these isolates. Resistance to erythromycin was detected in 129 isolates (63.2%) by the agar dilution test. Of these, 42 isolates (32.6%) were assigned to the constitutive macrolide, lincosamide, and streptogramin B resistance (cMLS) phenotype, and all carried the ermB gene; 4 (3.1%) were assigned to the inducible MLS resistance (iMLS) phenotype, and all harbored the ermTR gene; and 83 (64.3%) were erythromycin resistant but susceptible to clindamycin (M phenotype), and all possessed the mefA gene. Distributed by years, the rates of erythromycin resistance and different phenotypes were 61.7% (53.0% cMLS, 6.1% iMLS, and 40.9% M phenotype) between 1992 and 1995, 62.1% (12.2% cMLS and 87.8% M phenotype) in 1997, and 71. 0% (9.1% cMLS and 90.9% M phenotype) in 1998. Pulsed-field gel electrophoresis showed that all but 2 cMLS isolates were clonal in origin, and 17 clones were detected among the M-phenotype isolates. These results indicate that the high incidence and increasing rate of erythromycin-resistant GAS in southern Taiwan are due to the prevalence of multiple M-phenotype clones and that clindamycin may be the drug of choice for the treatment of infections with GAS in penicillin-hypersensitive patients in this area.
BACKGROUND: Although smoking is the major causal factor in the development of chronic obstructive pulmonary disease (COPD), only 10-20% of chronic heavy cigarette smokers develop symptomatic COPD which suggests the presence of genetic susceptibility. This genetic susceptibility to COPD might depend on variations in enzyme activities that detoxify cigarette smoke products such as microsomal epoxide hydrolase (mEPHX) and glutathione-S transferase (GST). As there is increasing evidence that several genes influence the development of COPD, multiple gene polymorphisms should be investigated to find out the genetic susceptibility to COPD. METHODS: The genotypes of 83 patients with COPD and 76 healthy smoking control subjects were determined by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (PCR-RFLP) for the mEPHX gene, and multiplex PCR for GST M1 and GST T1 genes. The frequencies of polymorphic genotypes of mEPHX, GST M1, and GST T1 genes were compared both individually and in combination in patients with COPD and healthy smokers. RESULTS: No differences were observed in the frequency of polymorphic genotypes in exons 3 and 4 of mEPHX, GST M1, and GST T1 genes between patients with COPD and healthy smokers. The frequencies of any combination of these genotypes also showed no differences between the COPD group and the control group. CONCLUSIONS: Genetic polymorphisms in mEPHX, GST M1, and GST T1 genes are not associated with the development of COPD in Koreans.