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Biomedical subjects

M Yao

Publications and source records attributed to M Yao.

At least 73 records · Page 4Linked to original sources
PubMed2001

[Clinical outcome and analysis of radical prostatectomy in clinical stage B and C prostate cancer].

Between 1989 and 1999, 40 patients treated with radical prostatectomy for clinical stage B and C prostate cancer were analyzed. Prostate-specific antigen (PSA) failure after radical prostatectomy occurred in four patients, and one of them died of clinical recurrence of prostate cancer. Cause-specific survival at 5 years was 91.7% and PSA failure-free rate at 5 years was 76.8%. Staging accuracy of CT and MRI image was not satisfactory. In 41.7% patients, extracapsular extension can not be determined. Preoperative serum PSA levels of pathologically organ-confined disease (OCD) patients were significantly lower than those of pathologically non-OCD patients. Further analysis indicated that preoperative serum PSA levels of greater than 20.1 ng/ml are useful predictors for pathologically non-OCD.

Aged↗
PubMed2001

[Study of neoadjuvant chemotherapy for invasive bladder cancer with MEC (methotrexate, epirubicin, cisplatin) therapy].

Eighteen patients with locally invasive bladder cancer were treated with 1 or 2 cycles of neoadjuvant chemotherapy consisting of methotrexate, epirubicin and cisplatin (MEC). All patients underwent radical cystectomy and pelvic lymph node dissection. Down-staging was observed in twelve (complete pathological response in 3 and partial pathological response in 9) patients (response rate were 67%). Four of the 18 patients died of disease and all of them had not achieved down-staging. Multivariate analysis revealed nodal status to be the only independent predictor. With regard to side effects, gastrointestinal symptoms and myelo-suppression were observed in almost all patients. Thrombocytopenia was observed in 13 patients (72%) including 7 patients who showed symptoms over grade 3. Gastro-intestinal symptoms and leukocytopenia disappeared with granisetron and granulocyte colony stimulating factor. There were no treatment-related deaths in this study. These results indicate that MEC therapy was safely performed and showed a high response rate in patients with locally invasive bladder cancer.

Aged↗
PubMed2001

[Investigation on the mechanism of discogenic groin pain].

OBJECTIVE: To investigate the mechanism of discogenic groin pain. METHODS: Twenty-one adult wistar rats were divided into experimental group (paravertebral sympathetic trunks were reserved), control group (paravertebral sympathetic trunks were resected) and self-control group (right paravertebral sympathetic trunks were resected, the left ones were reserved) randomly. Each group has 7 rats. Horseradish peroxidase (HRP) were injected into the L5-L6 intervertebral discs from right postero-lateral side. Bilateral L1, L2 spinal ganglia were sectioned after 48 hours to observe the HRP labeled cells and the effect of resection of paravertebral sympathetic trunks. Another 7 adult wistar rats were used. The same steps of injection, removal and section as in experimental group were taken. Combining method of HRP retrograde tracer with immunocytochemistry stained the sections to determine the nature of HRP labeled cells. RESULTS: HRP labeled cells were found in bilateral L1, L2 spinal ganglia in each group. The comparison results of labeled cells numbers between groups (experimental group from 22.5 +/- 7.1 to 29.3 +/- 9.7, control group from 12.9 +/- 5.1 to 13.3 +/- 4.9, P < 0.01) and of self-control group (left 24.8 +/- 6.7, 30.6 +/- 8.4, right 15.8 +/- 4.4, 14.5 +/- 4.1, P < 0.01) show that the numbers of HRP labeled cells were significantly less than that after resection of paravertebral sympathetic trunks. HRP and SP double-labeled cells can be recognized in bilateral L1, L2 spinal ganglia in immunocytochemistry experiment. CONCLUSIONS: Discogenic groin pain is referred pain which is transmitted by sympathetic nerves and appears in the area that was segmentally innervated by anterior rami of L1 and L, spinal nerves.

Animals↗
PubMed2000

Crystal structure of 1-aminocyclopropane-1-carboxylate deaminase from Hansenula saturnus.

The pyridoxal 5'-phosphate (PLP)-dependent enzyme 1-aminocyclopropane-1-carboxylate deaminase (ACCD) catalyzes a reaction that involves a ring opening of cyclopropanoid amino acid, yielding alpha-ketobutyrate and ammonia. Unlike other PLP-dependent enzymes, this enzyme has no alpha-hydrogen atom in the substrate. Thus, a unique mechanism for the bond cleavage is expected. The crystal structure of ACCD from Hansenula saturnus has been determined at 2.0 A resolution by the multiple wavelength anomalous diffraction method using mercury atoms as anomalous scatterers. The model was built on the electron density map, which was obtained by the density averaging of multiple crystal forms. The final model was refined to an R-factor of 22.5% and an R(free)-factor of 26.8%. The ACCD folds into two domains, each of which has an open twisted alpha/beta structure similar to the beta-subunit of tryptophan synthase. However, in ACCD, unlike in other members of the beta family of PLP-dependent enzymes, PLP is buried deep in the molecule. The structure provides the first view of the catalytic center of the cyclopropane ring opening.

Amino Acid Sequence↗
PubMed2000

Crystal structures of the ribonuclease MC1 from bitter gourd seeds, complexed with 2'-UMP or 3'-UMP, reveal structural basis for uridine specificity.

Ribonuclease MC1 (RNase MC1) isolated from seeds of bitter gourd (Momordica charantia) consists of 190 amino acids and is characterized by a preferential cleavage at the 5'-side of uridine. This uridine specificity distinguishes RNase MC1 from other enzymes belonging to the RNase T2 family. The three-dimensional structures of RNase MC1, in a complex with either 2'-UMP or 3'-UMP, were determined at 1.48 and 1.77 A resolutions, respectively. The side chains of Gln9 and Asn71 interact with O4 and N3, respectively, of the uracil base by hydrogen bondings. In addition, the uracil base is sandwiched by the hydrophobic side chains of Leu73 and Phe80. Compared with these amino acid residues and corresponding residues in RNases in the RNase T2 family, Gln9 and Phe80 are highly conserved in the RNases in T2 family, while Asn71 and Leu73 in RNase MC1 are variant in sequences. It is thus likely that interactions of the side chains of Asn71 and Leu73 with the uracil base are responsible for the absolute uridine specificity of RNase MC1. Site-directed mutagenesis experiments showed that replacement of Asn by Thr decreased both the catalytic efficiency and the binding affinity by 2.3- and 7.0-fold, respectively, and substitution of Leu73 for Ala predominantly decreased the binding affinity by 14. 5-fold, compared with findings in case of wild-type RNase MC1. It is thus demonstrated that Asn71 and Leu73 play an essential role in uridine preference for RNase MC1.

Amino Acid Sequence↗
PubMed2000

Role of the von Hippel-Lindau tumor suppressor protein during neuronal differentiation.

The von Hippel-Lindau (VHL) tumor suppressor protein down-regulates transcription by transcriptional elongation enhanced by antagonizing elongin B and C. Transcriptional regulation is an important control mechanism for embryogenesis and tumorigenesis. The VHL gene and protein are expressed in neuronal cells of the fetal and adult brain. However, the role of the VHL gene in the central nervous system (CNS) has not been elucidated. The VHL gene might modify the expression of various genes during embryogenesis and tumorigenesis in CNS. We investigated the role of the VHL gene in CNS development using rodent CNS progenitor cells. Here we show that expression of the VHL protein is correlated with neuronal differentiation but not with glial differentiation in CNS progenitor cells, and we also show that VHL gene transduction induces neuronal differentiation. In addition, a VHL mRNA antisense oligonucleotide inhibits differentiation of CNS progenitor cells and up-regulates their cell cycle. In conclusion, the VHL gene plays an essential role in neuronal differentiation as well as transcription.

Animals↗
PubMed2000

Structure and thermodynamics of the extraordinarily stable molten globule state of canine milk lysozyme.

Here, we show that an unfolded intermediate of canine milk lysozyme is extraordinarily stable compared with that of the other members of the lysozyme-alpha-lactalbumin superfamily, which has been studied previously. The stability of the intermediate of this protein was investigated using calorimetry, CD spectroscopy, and NMR spectroscopy, and the results were interpreted in terms of the structure revealed by X-ray crystallography at a resolution of 1.85 A to an R-factor of 17.8%. On the basis of the results of the thermal unfolding, this protein unfolds in two clear cooperative stages, and the melting temperature from the intermediate to the unfolded states is about 20 degrees C higher than that of equine milk lysozyme. Furthermore, the (1)H NMR spectra of canine milk lysozyme at 60 degrees C, essentially 100% of which exists in the intermediate, showed that small resonance peaks that arise from ring-current shifts of aliphatic protons are still present in the upfield region from 0 to -1 ppm. The protein at this temperature (60 degrees C) and pH 4.5 has been found to bind 1-anilino-naphthalene-8-sulfonate (ANS) with enhancement of the fluorescence intensity compared with that of native and thermally unfolded states. We interpret that the extraordinarily stable intermediate is a molten globule state, and the extraordinary stabilization of the molten globule state comes from stronger protection around the C- and D-helix of the aromatic cluster region due to the His-21 residue. The conclusion helps to explain how the molten globule state acquires its structure and stability.

Amino Acid Sequence↗
PubMed2000

Peripheral nerve regeneration in interleukin 6-deficient mice.

BACKGROUND: Interleukin 6 (IL-6) is a multifunctional cytokine with effects on central and peripheral neurons. OBJECTIVE: To investigate the role of IL-6 in peripheral nerve regeneration by comparing IL-6 knockout and wild-type mice in a sciatic nerve model of injury and repair. DESIGN/SUBJECTS: Forty C57/BL6 (wild-type) and 40 IL-6 knockout mice were randomly assigned to 1 of 4 groups: sham surgery, sciatic nerve crush injury, sciatic nerve transection without repair, and sciatic nerve transection with epineurial suture repair. Walking tracks were assessed preoperatively and postoperatively at 10-day intervals for 50 days by means of a previously described mouse sciatic functional index. Distal segments of the sciatic nerves were harvested at the completion of the study for histomorphometric evaluation. RESULTS: The wild-type and knockout mice that underwent sham surgery showed similarly unimpaired function (P =.64 on day 50). The IL-6 knockout mice with the crush injury demonstrated decreased function on day 10 compared with the wild-type mice (P<.01) but completely recovered by day 40 (P =.55). Both IL-6 knockout and wild-type mice that underwent nerve transection without repair failed to recover function (P =.06 on day 50). There was no statistical difference in recovery between wild-type and IL-6 knockout mice that underwent nerve transection with epineurial suture repair (P =.30 on day 50). The morphometric data showed no significant differences in distal axon count between the wild-type and knockout mice after suture repair or crush injury (P>.32). CONCLUSIONS: The absence of IL-6 does not appear to impair peripheral nerve recovery after sciatic nerve injury. Although in vitro and in vivo studies suggest a role for IL-6 in peripheral nerve physiology, this cytokine does not appear to have a substantial effect on functional recovery in a mouse sciatic nerve injury and repair model.

Animals↗
PubMed2000

Simultaneous quantitation of d7-nefazodone, nefazodone, d7-hydroxynefazodone, hydroxynefazodone, m-chlorophenylpiperazine and triazole-dione in human plasma by liquid chromatographic-mass spectrometry.

A rapid and sensitive LC-MS assay was developed and validated for the simultaneous determination of d7-nefazodone (d7-NEF), nefazodone (NEF), d7-hydroxynefazodone (d7-OH-NEF), hydroxynefazodone (OH-NEF), m-chlorophenylpiperazine (mCPP), and triazole-dione (Dione) in human plasma using trazodone (TRZ) as the internal standard (IS). A 0.1 mL aliquot of the plasma sample was precipitated with 0.1 mL of acetonitrile and vortexed for 2 min. After centrifugation, 50 microL of supernatant was mixed with 100 microL of 10 mM ammonium formate (pH = 4.0), and a 50 microL aliquot was injected onto a BDS Hypersil C18 column at a flow rate of 0.3 mL/min. The mobile phase consisting of 10 mM ammonium formate (pH = 4) and acetonitrile, 55:45 v/v, was used in an isocratic system. The mass spectrometer was programmed to admit the protonated molecules at m/z 477.2 (d7-NEF), 493.3 (d7-OH-NEF), 197.0 (mCPP), 372.0 (IS), 470.4 (NEF), 458.0 (Dione) and 486.2 (OH-NEF). Standard curves were linear (r(2) >/= 0.994) over the concentration range of 4-1000 ng/mL for Dione and 2-500 ng/mL for all other analytes. The lowest standard concentrations were the lower limits of quantitation for each analyte. The mean predicted quality control concentrations for all analytes deviated by less than 14.3% from the corresponding nominal values; the intra-assay and inter-assay precisions of the assay for all analytes were within 10.5% relative standard deviation. All analytes including the internal standard were stable in the injection solvent at room temperature for at least 24 h. The extraction recovery of the various analytes ranged from 79.2 to 109.1%. The validated assay was applied to the analysis of clinical samples obtained from a human subject who simultaneously received d7-NEF and NEF orally.

Chromatography, High Pressure Liquid↗
PubMed2000

Ex vivo expansion of CD34-positive peripheral blood progenitor cells from patients with non-Hodgkin's lymphoma: no evidence of concomitant expansion of contaminating bcl2/JH-positive lymphoma cells.

The aim of the present study was to evaluate the capacity to expand of hematopoietic stem cell (HSC) samples from eight patients with NHL, and to follow in parallel the fate of tumor cells in four of eight samples still containing bcl2/JH+ tumor cells after CD34+ or CD19-/20-/34+ cell selection. The presence of bcl2/JH+ cells was also investigated after expansion in four of eight samples, two of which were bcl2/JH at harvesting and two which were initially bcl2/JH+ but became bcl2/JH (below the level of PCR detection) after cell selection, to assess a possible reappearance of occult tumor cells after expansion culture. We used culture conditions that we previously had established to allow high level expansion of normal precursors, progenitors and LTC-ICs. In this study, particular attention was given to the role of Flt3-ligand, known to favor the growth of B cells. The expansion conditions were: 1.5 x 10(3) cells/ml in serum-free medium containing stem cell factor (SCF), interleukin-3 (IL-3), IL-6, granulocyte-stimulating factor (G-CSF), erythropoietin (Epo) +/- Flt3-ligand (Flt3-L) for 10 days. After culture, total cells, CFU-GMs, BFU-Es and LTC-ICs were expanded to a mean of 833-, 6.6-, 4.6-, and 1.8-fold, respectively with the cocktail of cytokines not including Flt3-L. When Flt3-L was added, the mean expansion values were 1095-, 31-, 15- and three-fold, respectively. Residual bcl2/JH+ cells present in four of eight samples before expansion were not detected after expansion. Similarly, no tumor cells reappeared after expansion of the two samples which had become negative after selection, as well as in the two samples which were bcl2/JH- at harvesting. These results suggest first that ex vivo expansion of hematopoietic stem cells in patients with non-Hodgkin's lymphoma is feasible without incurring the parallel risk of amplifying tumor cells; second, that Flt3-L did not stimulate the growth of tumor cells while it clearly favored the growth of normal progenitors.

Adult↗
PubMed2000

Genotoxic markers among butadiene polymer workers in China.

While 1,3-butadiene is carcinogenic in rodents, cancer causation in humans is less certain. We examined a spectrum of genotoxic outcomes in 41 butadiene polymer production workers and 38 non-exposed controls, in China, to explore the role of butadiene in human carcinogenesis. Because in vitro studies suggest that genetic polymorphisms in glutathione S-transferase enzymes influence genotoxic effects of butadiene, we also related genotoxicity to genetic polymorphisms in GSTT1 and GSTM1. Among butadiene-exposed workers, median air exposure was 2 p.p.m. (6 h time-weighted average), due largely to intermittent high level exposures. Compared with unexposed subjects, butadiene-exposed workers had greater levels of hemoglobin N-(2,3,4-trihydroxybutyl)valine (THBVal) adducts (P < 0.0001) and adduct levels tended to correlate, among butadiene-exposed workers, with air measures (P = 0.03). Butadiene-exposed workers did not differ, however, from unexposed workers with respect to frequency of uninduced or diepoxybutane-induced sister chromatid exchanges, aneuploidy as measured by fluorescence in situ hybridization of chromosomes 1, 7, 8 and 12, glycophorin A variants or lymphocyte hprt somatic mutation. Also among the exposed, greater THBVal levels were not associated with increases in uninduced sister chromatid exchanges, aneuploidy, glycophorin A or hprt mutations. Butadiene-exposed workers had greater lymphocyte (P = 0.002) and platelet counts (P = 0.07) and lymphocytes as a percentage of white blood cells were moderately correlated with greater THBVal levels (Spearman's phi = 0.32, P = 0.07). Among butadiene-exposed workers, neither GSTM1 nor GSTT1 genotype status predicted urinary mercapturic acid butanediol formation, THBVal adducts, uninduced sister chromatid exchanges, aneuploidy or mutations in the glycophorin A or hprt genes. Overall, the study demonstrated exposure to butadiene in these workers, by a variety of short-term and long-term measures, but did not show specific genotoxic effects, at the chromosomal or gene levels, related to that exposure.

Adult↗
PubMed2000

A precolumn derivatization high-performance liquid chromatographic method with improved sensitivity and specificity for the determination of astragaloside IV in Radix Astragali.

A reversed-phase high-performance liquid chromatographic method is developed for the determination of astragaloside (AGS) IV, which is known as the active constituent of Radix Astragali. The method uses precolumn derivatization with benzoyl chloride to form the benzoyl ester of AGS IV quantitatively and is carried out with a wide-ranging concentration (0.004-0.080 mg/mL) of the derivatized AGS IV. The eluent consists of 90% methanol, 4% tetrahydrofuran, 6% water, and 0.2% triethylamine, with vitamin D3 added as the internal standard.

Chromatography, High Pressure Liquid↗
PubMed2000

X-ray structure of azide-bound fully oxidized cytochrome c oxidase from bovine heart at 2.9 A resolution.

Two azide ions were identified, one between the Fe and Cu atoms in the O(2)-reduction site and the other at the transmembrane surface of the enzyme, in the crystal structure of the azide-bound form of bovine heart cytochrome c oxidase at 2.9 A resolution. Two geometries, a mu-1,3 type geometry between the Fe and Cu atoms and a terminal geometry on the Fe atom, are equally possible for an azide ion in the O(2)--reduction site. The other azide molecule was hydrogen bonded to an amide group of an asparagine and a hydroxyl group of tyrosine in a mu-1,1 type geometry. The antisymmetric infrared bands arising from these azide ions, which show essentially identical intensity [Yoshikawa & Caughey (1992), J. Biol. Chem. 267, 9757-9766], strongly suggest terminal binding of the azide to Fe. The electron density of all three imidazole ligands to Cu(B) was clearly seen in the electron-density map of the azide-bound form of bovine heart enzyme, in contrast to the crystal structure of the azide-bound form of the bacterial enzyme [Iwata et al. (1995), Nature (London), 376, 660-669], which lacks one of the three imidazole ligands to Cu(B).

Animals↗
PubMed2000

Germ-line mutation analysis in patients with von Hippel-Lindau disease in Japan: an extended study of 77 families.

We have previously reported on the analysis of germ-line mutations in Japanese von Hippel-Lindau disease (VHL) patients and found mutations in 26 families. We have now extended these studies to include an additional 41 VHL families. Germ-line mutation of the VHL gene was screened by DNA-SSCP, direct sequencing, and Southern blot analysis. To summarize all of the data we have studied in this and our previous report, germ-line mutations have been detected in 55 of 77 (73%) (type 1: 41/62 (66%) and type 2: 14/15 (93%)) families. We found similarities in the nature of germ-line mutations including mutational incidence, location, and DNA substitution patterns between Japanese and Western VHL. These similarities may reflect the predominance of endogenous mutational processes. We also found several interesting characteristics in Japanese VHL. Twenty of 41 (49%) intragenic mutations were unique and not reported in the Western VHL. Four mutations (Arg113Stop, Gln132Stop, Leu158Val, and Cys162Tyr) previously characterized as type 1 mutations were identified in the type 2 (with pheochromocytoma) Japanese families. Genotype-phenotype correlation study suggested non-missense mutations predicted to result in the loss of VHL function were associated with the occurrence of renal cell carcinoma, as in sporadic tumors. Our data add to the diversity of VHL germ-line mutations and provide a better understanding of VHL disease in terms of both clinical management and molecular pathogenesis.

Genotype↗
PubMed2000

Role of chromosome 3p12-p21 tumour suppressor genes in clear cell renal cell carcinoma: analysis of VHL dependent and VHL independent pathways of tumorigenesis.

AIMS: Chromosome 3p deletions and loss of heterozygosity (LOH) for 3p markers are features of clear cell renal cell carcinoma but are rare in non-clear cell renal cell carcinoma. The VHL tumour suppressor gene, which maps to 3p25, is a major gatekeeper gene for clear cell renal cell carcinoma and is inactivated in most sporadic cases of this disease. However, it has been suggested that inactivation of other 3p tumour suppressor genes might be crucial for clear cell renal cell carcinoma tumorigenesis, with inactivation (VHL negative) and without inactivation (VHL positive) of the VHL tumour suppressor gene. This study set out to investigate the role of non-VHL tumour suppressor genes in VHL negative and VHL positive clear cell renal cell carcinoma. METHODS: Eighty two clear cell renal cell carcinomas of known VHL inactivation status were analysed for LOH at polymorphic loci within the candidate crucial regions for chromosome 3p tumour suppressor genes (3p25, LCTSGR1 at 3p21.3, LCTSGR2 at 3p12 and at 3p14.2). RESULTS: Chromosome 3p12-p21 LOH was frequent both in VHL negative and VHL positive clear cell renal cell carcinoma. However, although the frequency of 3p25 LOH in VHL negative clear cell renal cell carcinoma was similar to that at 3p12-p21, VHL positive tumours demonstrated significantly less LOH at 3p25 than at 3p12-p21. Although there was evidence of LOH for clear cell renal cell carcinoma tumour suppressor genes at 3p21, 3p14.2, and 3p12, both in VHL negative and VHL positive tumours, the major clear cell renal cell carcinoma LOH region mapped to 3p21.3, close to the lung cancer tumour suppressor gene region 1 (LCTSGR1). There was no association between tumour VHL status and tumour grade and stage. CONCLUSIONS: These findings further indicate that VHL inactivation is not sufficient to initiate clear cell renal cell carcinoma and that loss of a gatekeeper 3p21 tumour suppressor gene is a crucial event for renal cell carcinoma development in both VHL negative and VHL positive clear cell renal cell carcinoma.

Carcinoma, Renal Cell↗
PubMed2000

Resting and active properties of pyramidal neurons in subiculum and CA1 of rat hippocampus.

Action potentials are the end product of synaptic integration, a process influenced by resting and active neuronal membrane properties. Diversity in these properties contributes to specialized mechanisms of synaptic integration and action potential firing, which are likely to be of functional significance within neural circuits. In the hippocampus, the majority of subicular pyramidal neurons fire high-frequency bursts of action potentials, whereas CA1 pyramidal neurons exhibit regular spiking behavior when subjected to direct somatic current injection. Using patch-clamp recordings from morphologically identified neurons in hippocampal slices, we analyzed and compared the resting and active membrane properties of pyramidal neurons in the subiculum and CA1 regions of the hippocampus. In response to direct somatic current injection, three subicular firing types were identified (regular spiking, weak bursting, and strong bursting), while all CA1 neurons were regular spiking. Within subiculum strong bursting neurons were found preferentially further away from the CA1 subregion. Input resistance (R(N)), membrane time constant (tau(m)), and depolarizing "sag" in response to hyperpolarizing current pulses were similar in all subicular neurons, while R(N) and tau(m) were significantly larger in CA1 neurons. The first spike of all subicular neurons exhibited similar action potential properties; CA1 action potentials exhibited faster rising rates, greater amplitudes, and wider half-widths than subicular action potentials. Therefore both the resting and active properties of CA1 pyramidal neurons are distinct from those of subicular neurons, which form a related class of neurons, differing in their propensity to burst. We also found that both regular spiking subicular and CA1 neurons could be transformed into a burst firing mode by application of a low concentration of 4-aminopyridine, suggesting that in both hippocampal subfields, firing properties are regulated by a slowly inactivating, D-type potassium current. The ability of all subicular pyramidal neurons to burst strengthens the notion that they form a single neuronal class, sharing a burst generating mechanism that is stronger in some cells than others.

Action Potentials↗
PubMed2000

[Study of free to total prostate specific antigen ratio in the detection of patients with prostate cancer].

BACKGROUND: We investigated the clinical usefulness of free to total serum prostate specific antigen (PSA) ratio (F/T ratio) in order to improve the specificity of total PSA measurement for detecting prostate cancer. METHOD: In this study 129 patients with total PSA level 4-20 ng/ml underwent transrectal ultrasound guided sextant biopsy. Serum samples were assessed for total PSA, free PSA and the F/T ratio calculated. All patients were pathologically diagnosed as benign prostatic hyperplasia or prostate cancer. RESULTS: Of 129 patients 21 had prostate carcinoma (PCa) and 108 had benign prostatic hyperplasia (BPH) from the results of prostate biopsies. The mean of total PSA were not significantly different between men with PCa and with BPH. The mean of free PSA for PCa was significantly lower than that for BPH (p = 0.043). Furthermore, the mean of F/T ratio was significantly different between PCa and BPH group (p = 0.0014). The F/T ratio had a higher specificity than total PSA at all levels of sensitivity in detecting prostate cancers. Sensitivity, specificity and accuracy for cancer detection at a cut off 0.12 was 90.4%, 51.8% and 58.1%, respectively. Also, free PSA was as useful as F/T ratio for cancer detection when analyzed in receiver operating characteristic curves analysis. When determined the cut off number of free PSA at 0.78 ng/ml, the sensitivity, specificity and accuracy for cancer detection were 61.9%, 66.7% and 65.9%, respectively. CONCLUSION: This study indicated that the F/T ratio and free PSA could improve the specificity without impairing the sensitivity for detecting PCa in patients with 4-20 ng/ml of total PSA.

Aged↗