Comparison of accuracy among three generations of Partin tables in a Chinese cohort

INTRODUCTION

To perform a head to head comparison among three generations of Partin tables, namely from 1997, 2001 and the last updated version of 2007, in a Chinese cohort of prostate cancer.

MATERIAL AND METHODS

Clinical and pathological data of 198 consecutive Chinese patients were retrospectively analyzed, who underwent radical prostatectomy for clinically localized prostate cancer between January 2005 and May 2010. Three versions of the Partin tables were compared for their accuracy and performance to predict final pathological stage using receiver operating characteristic (ROC) curve.

RESULTS

Of the whole cohort 58.6% were presented with organ-confined disease (OCD), 10.1% had lymph node involvement (LNI), and 31.3% had locally advanced disease (LAD), while 21.2% had extraprostatic extension (ECE) and 10.1% showed seminal vesicle involvement (SVI). The area under the ROC curve (AUC) of the Partin Tables 1997, 2001 and 2007 was 0.732, 0.722 and 0.695 for OCD; 0.647, 0.594 and 0.577 for LAD; 0.856, 0.872 and 0.829 for LNI, respectively.

CONCLUSION

All three generations of the Partin tables showed a good accuracy to predict OCD, and LNI. However, the predictive accuracy for LAD was more limited. Overall, the newer versions of the Partin tables could not exceed the version of 1997 in their predictive accuracy for the present Chinese cohort. Our results suggest caution when using newly introduced predictive tools that are not supported by population-specific accuracy tests.

Serum miRNA-21: elevated levels in patients with metastatic hormone-refractory prostate cancer and potential predictive factor for the efficacy of docetaxel-based chemotherapy

BACKGROUND

miR-21 has been recognized as an "onco-microRNA" with the activity of negatively modulating the expression of tumor-suppressor genes. However, its role in prostate cancer (CaP) has not been well-documented. We designed this study to assess the potential function of serum miR-21 in the progression of CaP.

METHODS

Serum samples of 56 patients, including 20 patients with localized CaP, 20 with androgen-dependent prostate cancer (ADPC), 10 with hormone-refractory prostate cancer (HRPC), and 6 with benign prostatic hyperplasia (BPH), were collected for the measurement of miR-21. The 10 HRPC patients were administered docetaxel-based chemotherapy. Quantification of miR-21 was assayed by specific TaqMan qRT-PCR.

RESULTS

Serum miR-21 level was found to correlate to serum PSA level in patients with ADPC and HRPC, P = 0.012 and 0.049, respectively. There was no significant difference in serum miR-21 level between BPH, localized CaP and ADPC with PSA level <4 ng/ml. Higher levels of miR-21 were detected in patients with HRPC and ADPC with PSA level >4 ng/ml. Six of the 10 HRPC patients reached partial remission with a decreased PSA level of >50% after chemotherapy. Serum miR-21 levels were higher in patients who were resistant to docetaxel-based chemotherapy when compared to those sensitive to chemotherapy, P = 0.032.

CONCLUSIONS

Serum miR-21 levels are elevated in HRPC patients, especially in those resistant to docetaxel-based chemotherapy. It may be applicable as a marker to indicate the transformation to hormone refractory disease, and a potential predictor for the efficacy of docetaxel-based chemotherapy.

Conception and optimization of a membrane electrode assembly microbial fuel cell (MEA-MFC) for treatment of domestic wastewater

A membrane electrode assembly (MEA) for microbial fuel cells (MEA-MFC) was developed for continuous electricity production while treating domestic wastewater concurrently. It was optimized via three upgraded versions (noted α, β and γ) in terms of design (current collectors, hydrophilic separator nature) and operating conditions (hydraulic retention time, external resistance, aeration rate, recirculation). An overall rise of power by over 100% from version α to γ shows the importance of factors such as the choice of proper construction materials and prevention of short-circuits. A power of 2.5 mW was generated with a hydraulic retention time of 2.3 h when a Selemion proton exchange membrane was used as a hydrophilic separator in the MEA and 2.8 mW were attained with a reverse osmosis membrane. The MFC also showed a competitive value of internal resistance (≈40-50 Ω) as compared to the literature, especially considering its large volume (3 L). However, the operation of our system in a complete loop where the anolyte was allowed to trickle over the cathode (version γ) resulted in system failure.

[External validation of the Partin tables 2007 in Chinese prostate cancer patients]

OBJECTIVE

To validate the 2007 Partin tables externally, which are based on the population of United States, using a cohort of Chinese prostate cancer patients.

METHODS

All of the patients enrolled and underwent radical prostatectomy between January 2006 and February 2010 were reviewed. The cases without preoperative hormone therapy and pelvic lymph node involvement according to radiologic tests were used for the external validation of the 2007 Partin tables. A comparative analysis of the clinical and pathological parameters of this Chinese cohort and Partin tables cohort was performed. Values of areas under the receiver operating characteristic (ROC) curve were used to assess predictive accuracy for the Chinese cohort.

RESULTS

The mean age of the whole cohort was 67 years. The serum prostate specific antigen level, Gleason score and clinical stage of this cohort were higher than the Partin tables cohort. The pathological outcomes analysis revealed that the rates of organ confined disease, capsular penetration, seminal vesicle involvement and lymph node involvement were 62.3%, 16.7%, 12.3% and 8.8%, respectively. The area under the ROC curve (AUC) for organ confined disease, capsular penetration, seminal vesicle involvement and lymph node involvement were 0.735, 0.653, 0.601 and 0.845.

CONCLUSIONS

The Partin tables discriminate well for Chinese patients at risk for positive lymph node. The discrimination of organ confined disease is also acceptable and the discrimination of capsular penetration and seminal vesicle involvement is more limited.

[The survival analysis of metastatic prostate cancer]

OBJECTIVES

To analyze the clinical and pathological informations of metastatic prostate cancer patients to find the predictive factors of the survival.

METHODS

To filter 364 cases of metastatic prostate cancer in the 940 cases of prostate cancer that were treated in Cancer Hospital Fudan University in Shanghai from March 1998 to June 2009, the cases had hormonal therapy and full clinical and pathological records. All the 364 cases were followed up and the clinical and pathological informations were analyzed, to find the predictive factors that related to the prognosis. Statistic software SPSS 15.0 was used for analysis. Cumulative survival was analyzed by the method of Kaplan-Meier. Cox regression was used for univariate and multivariate analysis. Log-rank method was used for the significance test.

RESULTS

The last follow-up date was 30th June 2009 and the median follow-up time was 24 months. At the final follow-up, 240 cases were alive, 109 cases were dead and 15 cases were lost to follow up. The median survival time of metastatic prostate cancer was 64 months, and the one-year, two-year, three-year, four-year, five-year survival rate was 92%, 78%, 66%, 60%, 54%. The univariate analysis indicated that Gleason score (P = 0.033), clinical stage (P < 0.001), the effectiveness of hormonal therapy (P < 0.001), the prostate specific antigen (PSA) nadir during hormonal therapy (P < 0.001) and the time from the start of hormonal therapy to the PSA nadir (P = 0.002) were predictive factors for the survival time of metastatic prostate cancer. The multivariate analysis indicated that the PSA nadir during hormonal therapy (P < 0.001) and the time from the start of hormonal therapy to the PSA nadir (P < 0.001) were independent factors that predict the survival time of metastatic prostate cancer.

CONCLUSION

The PSA nadir during hormonal therapy and the time from the start of hormonal therapy to the PSA nadir are independent factors that predict the survival time of metastatic prostate cancer.

Tumor cytoreduction results in better response to androgen ablation--a preliminary report of palliative transurethral resection of the prostate in metastatic hormone sensitive prostate cancer

OBJECTIVES

To investigate the oncologic influence of transurethral resection of the prostate (TURP) as a cytoreductive surgery in metastatic hormone sensitive prostate cancer (mHSPC), in the setting of continuous complete androgen blockade (CAB).

MATERIALS AND METHODS

Medical histories of 146 consecutive Chinese males with newly diagnosed mHSPC, registered in our institution in 2006 and 2007, were reviewed. All of these patients received CAB as initial systematic therapy. Demographics and cancer control outcomes from 39 mHSPC patients who underwent TURP for a relief of bladder outlet obstruction were compared with those of the other 107 who received CAB only when they were still hormone-sensitive. Median follow-up was 15 months (3 to 27 months).

RESULTS

Age at diagnosis, baseline PSA, and biopsy Gleason score were comparable between the 2 groups. Patients who underwent a TURP had lower PSA nadir (median 0.15 ng/ml vs. 0.82 ng/ml, P = 0.015) and longer time to PSA nadir (11.2 months vs. 6.4 months, P < 0.001). More patients in the non-TURP group developed hormone refractory prostate cancer (P = 0.007). The TURP group had a tendency towards longer disease-specific survival and overall survival (24.4 months vs. 24.1 months and 24.4 months vs. 22.9 months, respectively), though this did not reach statistical significance.

CONCLUSIONS

TURP resulted in a better and more prolonged response to hormone therapy in mHSPC, with a trend towards positive influence in disease specific survival and overall survival. To date, our preliminary report is the first study regarding long-term survival of cytoreductive surgery in mHSPC, and further investigations are warranted.

Prostate-specific antigen half-life: a new predictor of progression-free survival and overall survival in Chinese prostate cancer patients

We investigated the potential value of prostate-specific antigen half-life (PSAHL) and decreasing velocity (PSAVd) to predict progression-free survival (PFS) and overall survival (OS) in Chinese patients with prostate cancer. A total of 153 patients treated with hormonal therapy were included in the study. Of these, 78 patients progressed to hormone-refractory prostate cancer (HRPC) and 24 patients died by the end of follow-up. PSAHL was defined as the time during which prostate-specific antigen (PSA) concentration became half of the initial value during the first hormonal therapy. PSAVd reflected the decreasing velocity of PSA during the first hormonal therapy. PFS was defined as the interval from the beginning of hormonal therapy to HRPC. Cox proportional hazards regression analysis was used to evaluate whether PSAHL and PSAVd were significantly associated with PFS and OS. The median PSAHL and PSAVd were 0.50 months and 33.8 ng mL(-1) per month. The median PFS and OS were 22.7 months (95% confidence interval [CI], 22.0-29.6 months) and 43.5 months (95% CI, 37.9-48.4 months), respectively. On univariate and multivariate analysis, long PSAHL (> 0.5 months), metastatic disease, high biopsy Gleason scores (>or= 8) and high nadir PSA (> 0.4 ng mL(-1)) were all found to be significantly associated with short PFS. Long PSAHL, high nadir PSA and short PSA doubling time (PSADT Collapse

Key Words

• predictor
• prognosis
• prostate cancer
• prostate-specific antigen decreasing velocity
• prostate-specific antigen half-life

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MESH Headings

• Adult
• Aged
• Aged, 80 and over
• China
• Disease Progression
• Half-Life
• Humans
• Male
• Middle Aged
• Proportional Hazards Models
• Prostate-Specific Antigen/blood
• Prostatic Neoplasms/blood
• Prostatic Neoplasms/immunology
• Prostatic Neoplasms/pathology
• Survival Analysis

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Grants Collapse

Prevalence of incidental prostate cancer in patients undergoing radical cystoprostatectomy: data from China and other Asian countries

The purpose of this study is to investigate the frequency of prostate cancer (Pca) discovered incidentally in radical cystoprostatectomy specimens in Asia and to determine the feasibility of prostate-sparing cystectomy (PSC) for Asian patients. Ninety-two male bladder cancer patients who underwent radical cystoprostatectomy at our center between January 2003 and January 2008 were included in this study. The mean age of patients was 67.1 years (range: 32-75 years). Prostate-specific antigen (PSA) levels and digital rectal examination (DRE) results before surgery were obtained retrospectively. Prostates of all patients were embedded and sectioned at 5-mm intervals. The same pathologist examined the prostatic tissues from radical cystoprostatectomy specimens. Finally, a structured literature review was performed using MEDLINE and PUBMED to estimate the occurrence of incidental Pca in Asia. Of the 92 patients, 3 (3.3%) were found to have Pca; in one out of three (33.3%) patients the disease was clinically significant due to a Gleason grade 4 carcinoma. Eight articles were included in our review. The overall incidence of Pca discovered incidentally in radical cystoprostatectomy specimens in Asia was 9.9% (64/642). When age was restricted to < 60 years, only 7 out of 222 (3.2%) patients were found to have synchronous Pca, and none of the cases was clinically significant. The occurrence of Pca in radical cystoprostatectomy specimens in Asia is much lower than that in Western countries. PSC might be feasible for Asian patients under a strict preoperative selection.

The value of squamous cell carcinoma antigen in the prognostic evaluation, treatment monitoring and followup of patients with penile cancer

PURPOSE

We examined whether squamous cell carcinoma antigen has significant value for prognostic evaluation, treatment monitoring and followup in patients with penile cancer.

MATERIALS AND METHODS

Serum squamous cell carcinoma antigen was prospectively measured in 63 patients with penile squamous cell carcinoma from 2005 to 2007. The normal range of squamous cell carcinoma antigen was set as less than 1.50 mug/l. Statistical data analysis was done by the nonparametric method. Survival analysis was performed with the log rank test and the Cox proportional hazard model.

RESULTS

Of all patients 23.8% had a value of squamous cell carcinoma antigen that was greater than the upper limit of normal. Increased values correlated positively with lymph node metastasis (p = 0.005). However, squamous cell carcinoma antigen could not accurately predict occult inguinal lymph node metastasis in clinically node negative cases. Preoperatively squamous cell carcinoma antigen was an independent prognostic factor for disease-free survival in patients with node positive penile cancer (OR 0.13, p = 0.006). Combining pretreatment squamous cell carcinoma antigen and the percent of decrease after surgery was informative for predicting disease recurrence. The prognostic value of squamous cell carcinoma antigen was also observed in a small number of patients treated with chemotherapy. During followup continuously increasing squamous cell carcinoma antigen indicated tumor progression without a significant lead time effect.

CONCLUSIONS

Squamous cell carcinoma antigen is not a sensitive marker of tumor burden. However, it has prognostic significance for disease-free survival in patients with penile cancer treated with surgery.

In vitro inhibitory effect of interleukin-6 on the metabolism of DA and NE in PC12 cell line and the related signal transduction

AIM: To examine the relationship between interleukin (IL)-6 and the anabolism of DA and NE in the PC12 cell line, and to explore the related signal transduction.

METHODS: Differentiated PC12 cells were used to examine the inhibitory effect of IL-6 (0.5, 1 and 1.5 mg/L) on the anabolism of DA and NE. Apoptosis of PC12 cells was measured by fluocytometry. The concentration of DA and NE in PC12 cells and the medium was determined by HPLC. After exposure to IL-6 (1 mg/L), protein expression of p-STAT3 in the nuclei and STAT3 and tyrosine hydroxylase (TH) in the cytoplasm of PC12 cells was measured by Western blotting.

RESULTS: The apoptosis rate of PC12 cells cultured in the presence of different concentrations of IL-6 did not differ significantly. The metabolism of DA and NE in PC12 cells changed in accordance with the concentration of IL-6 added to the medium, and it obviously differed from that of the controls at a concentration of 1 mg/L. IL-6 enhanced the protein expression of STAT3 and the transcription to nuclei and decreased protein expression of TH.

CONCLUSION: IL-6 reduces the synthesis of DA and NE in vitro. The mechanism underlying the effects of IL-6 on the synthesis of DA and NE involves JAK-STATs signal transduction and decreases protein expression of TH.

Overexpression of CDC91L1 (PIG-U) in bladder urothelial cell carcinoma: correlation with clinical variables and prognostic significance

OBJECTIVE

To investigate cell division cycle 91-like 1 (CDC91L1; also called phosphatidylinositol glycan class U, PIG-U) expression in bladder cancer at both the mRNA and protein levels, and to study its clinical and prognostic significance, as CDC91L1 was recently identified as a new oncogene in human bladder cancer and its role in the biological behaviour of bladder cancer is largely unknown.

PATIENTS AND METHODS

In all, 73 bladder tumours and 14 samples of normal bladder urothelium were studied by reverse-transcription polymerase chain reaction (PCR), real-time quantitative PCR and immunohistochemistry.

RESULTS

The normalized CDC91L1 mRNA copy number in tumours was significantly greater than in normal controls (P < 0.05). There was overexpression of CDC91L1 mRNA in 30.1% (22/73) of the bladder tumours compared with the normal urothelium. At the protein level, 75.3% (55/73) of the bladder tumours and two of 14 of the normal urothelium had high expression of CDC91L1 protein, which is statistically significant (P < 0.001). The correlation between CDC91L1 protein and tumour grade, and muscle invasion of tumour was significant (both P < 0.05). In addition to tumour extent and tumour grade, CDC91L1 protein was an independent predictor of recurrence for superficial bladder cancer and had a trend to predict tumour progression.

CONCLUSIONS

CDC91L1 (PIG-U) plays a role in the development of bladder urothelial cell carcinoma. CDC91L1 protein might be a potential biomarker for prediction of recurrence and a therapeutic target in bladder cancer.

Refined localization of a punctate palmoplantar keratoderma gene to a 5.06-cM region at 15q22.2-15q22.31

BACKGROUND

Punctate palmoplantar keratoderma (PPK) is a rare autosomal dominant cutaneous disorder characterized by numerous hyperkeratotic papules distributed on the palms and soles. Two loci for punctate PPK were recently found to be located on 8q24.13-8q24.21 and 15q22-15q24. However, no genes for this disease have been identified to date. Objectives To refine the previously mapped regions and to identify the disease gene locus in a four-generation Chinese family with punctate PPK.

METHODS

Genetic linkage analysis was carried out in this family using microsatellite markers on chromosomes 8q and 15q. Two-point linkage analysis was performed using Linkage programs version 5.10 and the haplotype was constructed using Cyrillic version 2.02 software.

RESULTS

We failed to confirm our previous locus at 8q24.13-8q24.21, but significant evidence for linkage was observed in the region of 15q with a maximum two-point LOD score of 5.38 at D15S153 (theta = 0.00). Haplotype analysis localized the punctate PPK locus within the region defined by D15S651 and D15S988. This region overlaps by 5.06 cM with the previously reported punctate PPK region.

CONCLUSIONS

This study refines a disease gene causing punctate PPK to a 5.06-cM interval at 15q22.2-15q22.31.

Refinement of a locus for Marie Unna hereditary hypotrichosis to a 1.1-cM interval at 8p21.3

BACKGROUND

Marie Unna hereditary hypotrichosis (MUHH) is a rare autosomal congenital alopecia with progressive hair loss starting in early childhood and accelerating at puberty. A locus for MUHH has been mapped on chromosome 8p21 but no genes for MUHH have been identified to date.

OBJECTIVES

To refine the MUHH locus to a narrow chromosome region to facilitate cloning of the gene.

METHODS

We performed genotyping and linkage analysis in a multigeneration Chinese family with MUHH, using 18 high-density microsatellite markers spanning the previously mapped interval at 8p21.

RESULTS

Significant evidence for linkage was observed in this region, with a maximum two-point LOD score of 3.01 (theta = 0). Haplotype analysis localized the MUHH locus within the region defined by D8S282 and D8S1839. This region overlaps by 1.1-cM with the previously reported MUHH region and represents a physical distance of about 380 kb.

CONCLUSIONS

This study provides a refined map location (1.1 cM) for isolation of the gene causing MUHH. These data also indicate the existence of a common MUHH locus at 8p21.3 between affected caucasian and Chinese families.

The effect of residual chemical oxygen demand on anoxic and aerobic phosphate uptake and release with various intracellular polymer levels

This study investigated the anoxic and aerobic phosphate uptake and release reactions and the fraction of denitrifying phosphate-accumulating organisms (DPAOs) under various initial chemical oxygen demand (COD) and residual COD conditions. The results showed that DPAOs and non-DPAOs could release phosphate when high soluble COD was present. Consequently, the phosphate-uptake potential was dynamic and increased when the initial COD increased, the initial polyhydroxyalkanoates (PHA) increased, and the residual COD decreased. Furthermore, the electron acceptor (oxygen of nitrate) has more significant influence on the phosphate uptake/release characteristics, while the residual COD concentrations have little influence on that. The fraction of DPAOs to phosphate-accumulating organisms was 42% when the initial PHA storage was enough by both DPAOs and non-DPAOs. This was closely related to the relative phosphate uptake (47%) in the anoxic zone of the process.

[Construction of combined site-directed random mutation libraries of recombinant human lymphotoxin]

To construct the combined site-directed random mutation library of recombinant human Lymphotoxin (rhLT) for in vitro molecular evolution study, and to study the structure and function relationship. The random point mutations at the sites of 46,106 and 130 were individually generated by overlap PCR amplification with the random nucleotide primers. The three point mutations were combined and cloned into pMD-18T vector to construct the combined mutation library. DNA sequencing was used to evaluate the diversity and randomness of the mutation sites. The combined mutation library was re-engineered, inserted in prokaryotic expression vector pBV220, transformed and expressed in Escherichia coli strain DH5alpha. The biological activity of some of the mutants was tested in 1929 mouse fibroblast cells. As much as 1.5 x 10(5) clones were obtained, which represents 4.5 times of the complete mutation libraries at 99% confidence. Sequencing 50 clones revealed no obvious bias in the nucleotide and amino acid mutations at the sites. Among the 30 expressed samples underwent for the bioassay, 70% (21 samples) were inactive, 23.3% (7 samples) had lower activity than rhLT, the remaining 6.7% (2 samples) had higher activity than rhLT. The combined site-directed random mutation library of rhLT has been constructed successfully. In combination with phase display, the library is ready for in vitro molecular evolution study.

Delayed appearance of decorin in healing burn scars

AIMS

We have previously shown that hypertrophic scar tissue from burn patients contains abnormally high amounts of the proteoglycans versican and biglycan and reduced amounts of decorin, in comparison with normal dermis or mature scar. The lack of decorin may account for the poor organization of collagen fibrils in the nodular areas of these scars. Decorin has also been reported to neutralize the fibrogenic growth factor TGF-beta1. This study was conducted to monitor the time-course of expression of decorin in healing burn wounds by in-situ hybridization to determine whether its absence from hypertrophic scars could result from reduced synthesis.

METHODS AND RESULTS

Scar tissue from 19 patients and normal dermis from six patients, was fixed in paraformaldehyde, embedded in paraffin and sectioned. Digoxigenin-labelled cRNA probes were prepared from a plasmid containing a 622-bp insert of human decorin cDNA and used for in-situ hybridization. Total numbers of connective tissue cells and cells positive for decorin mRNA were counted in 10 random fields in the upper (papillary), middle and lower (reticular) one-thirds of the dermis. In all regions the number and percentages of cells with decorin mRNA were low during the first 12 months after injury (eight samples), much higher between 12 and 36 months (seven samples) and low and similar to those in normal skin after 36 months (five samples). The differences between intermediate and early or late stage samples were statistically significant (one-way ANOVA). Immunohistochemistry showed little staining for decorin in early stage samples and much stronger staining in mid-stage. Late stage tissue showed intense staining for decorin, almost comparable to that in normal dermis.

CONCLUSION

Expression of decorin in burn wounds is suppressed for about 12 months and then increases at a time when resolution of hypertrophic scarring is generally considered to occur.

Molecular distinction of phosphatidylcholine synthesis between the CDP-choline pathway and phosphatidylethanolamine methylation pathway

In addition to the CDP-choline pathway for phosphatidylcholine (PC) synthesis, the liver has a unique phosphatidylethanolamine (PE) methyltransferase activity for PC synthesis via three methylations of the ethanolamine moiety of PE. Previous studies indicate that the two pathways are functionally different and not interchangeable even though PC is the common product of both pathways. This study was designed to test the hypothesis that these two pathways produce different profiles of PC species. The PC species from these two pathways were labeled with specific stable isotope precursors, D9-choline and D4-ethanolamine, and analyzed by electrospray tandem mass spectrometry. Our studies revealed a profound distinction in PC profiles between the CDP-choline pathway and the PE methylation pathway. PC molecules produced from the CDP-choline pathway were mainly comprised of medium chain, saturated (e.g. 16:0/18:0) species. On the other hand, PC molecules from the PE methylation pathway were much more diverse and were comprised of significantly more long chain, polyunsaturated (e.g. 18:0/20:4) species. PC species from the methylation pathway contained a higher percentage of arachidonate and were more diverse than those from the CDP-choline pathway. This profound distinction of PC profiles may contribute to the different functions of these two pathways in the liver.

Quantitative 19F NMR study of trifluorothymidine metabolism in rat brain

Metabolism of trifluorothymidine (TFT) and its transport across the blood-brain barrier (BBB) has been measured quantitatively in rats by fluorine-19 nuclear magnetic resonance spectroscopy ((19)F NMR). It is demonstrated that TFT crosses the BBB in micromolar quantities and is metabolized in brain tissue primarily to its free base trifluoromethyluracil (TFMU) by the enzyme thymidine phosphorylase (TP). It is further proposed that the rate of TFMU production can be used as a measure of cerebral TP. The glycols of both TFMU, and to a lesser degree TFT, are generated via an oxidative route. In contrast, the major pathway for hepatic metabolism of this compound is through reduction of the nitrogen base moiety and generation of 5-6-dihydro species followed by ring degradation. Thus, in addition to TFMU as well as the dihydroxy (glycol)-, and the dihydro-species of both TFT and TFMU, alpha-trifluoromethyl-beta-ureidopropionic acid (F(3)MUPA) and alpha-trifluoromethyl-beta-alanine (F(3)MBA) were detected in liver extracts. The total metabolite levels in liver were 2-5 times higher than in the brain. Low levels of fluoride ion were detected in all the extracts from brain and liver, as well as blood and urine. This study characterizes TFT as a potential chemotherapeutic agent for use against brain tumors.

Myelin-associated glycoprotein in myelin and expressed by Schwann cells inhibits axonal regeneration and branching

The mammalian CNS does not regenerate after injury due largely to myelin-specific inhibitors of axonal growth. The PNS, however, does regenerate once myelin is cleared and myelin proteins are down-regulated by Schwann cells. Myelin-associated glycoprotein (MAG), a sialic acid binding protein, is a potent inhibitor of neurite outgrowth when presented to neurons in culture. Here, we present additional evidence that strongly supports the suggestion that MAG contributes to the overall inhibitory properties of myelin. When myelin from MAG-/- mice is used as a substrate, axonal length is 100 and 60% longer for neonatal cerebellar and older DRG neurons, respectively, compared to MAG+/+ myelin. The converse is true for neurites from neonatal DRG neurons, which are twice as long on MAG+/+ relative to MAG-/- myelin, consistent with MAG's dual role of promoting axonal growth from neonatal DRG neurons but inhibiting growth in older DRG and all other postnatal neurons examined. Furthermore, desialylating neurons reverses inhibition by CNS myelin by 45%. Contrary to previous reports, under these conditions PNS myelin is also inhibitory for axonal regeneration. Importantly, results using PNS MAG-/- myelin as a substrate suggest that MAG contributes to this inhibition. Finally, when Schwann cells not expressing MAG and permissive for axonal growth are induced to express MAG by retroviral infection, not only is axonal outgrowth greatly inhibited by these cells but so also is neurite branching. This suggests for the first time that MAG not only affects axonal regeneration but may also play a role in the control of axonal sprouting.

Expression and localization of insulin-like growth factor-1 in normal and post-burn hypertrophic scar tissue in human

The migration of epithelial cells from dermal appendages toward the wound surface is essential for re-epithelialization of partial thickness burn injuries. This study provides evidence that these cells in vivo synthesize a mitogenic and fibrogenic factor, insulin-like growth factor-1 (IGF-1), which may promote the development of the post-burn fibroproliferative disorder, hypertrophic scarring (HSc). An evaluation of 7 post-burn hypertrophic scars, 7 normal skin samples obtained from the same patients and 4 mature scars revealed that IGF-1 expressing cells from the disrupted sweat glands tend to reform small sweat glands of 4-10 cells/gland in post-burn HSc. The number of these cells increases with time and the glands become larger in mature scar. Other epithelial cells such as those found in sebaceous glands and basal and suprabasal keratinocytes, also express IGF-1 protein and mRNA as detected by Northern and RT-PCR analysis of RNA obtained from whole skin and separated epidermis and dermis. However, cultured keratinocytes did not express mRNA for IGF-1. Histological comparisons between normal and HSc sections show no mature sebaceous glands in dermal fibrotic tissues but the number of IGF-1 producing cells including infiltrated immune cells was markedly higher in the dermis of hypertrophic scar tissues relative to that of the normal control. In these tissues, but not in normal dermis, IGF-1 protein was found associated with the extracellular matrix. By in situ hybridization, IGF-1 mRNA was localized to both epithelial and infiltrated immune cells. Collectively, these findings suggest that in normal skin, fibroblasts have little or no access to diffusible IGF-1 expressed by epithelial cells of the epidermis, sweat and sebaceous glands; while following dermal injury when these structures are disrupted, IGF-1 may contribute to the development of fibrosis through its fibrogenic and mitogenic functions. Reformation of sweat glands during the later stages of healing may, therefore, limit this accessibility, and lead to scar maturation.

Fibroblasts from post-burn hypertrophic scar tissue synthesize less decorin than normal dermal fibroblasts

1. Fibroblast cultures were established from biopsies of hypertrophic scar and normal dermis taken from nine patients recovering from second- and third-degree burns. The capacity of these fibroblasts to synthesize the small proteoglycan decorin was assessed by quantitative Western blot analysis of conditioned medium collected from confluent cultures. Levels of mRNA for decorin were assessed by quantitative Northern analysis. Since transforming growth factor-beta 1 is implicated in various fibrotic conditions, including post-burn hypertrophic scar, its effect on decorin synthesis by these paired fibroblast cell strains was assessed. 2. Production of decorin was lower in all cell strains of hypertrophic scar fibroblasts tested, compared with normal dermal fibroblasts cultured from the same patients (mean 49 +/- 23%; P < 0.001, n = 9). Levels of mRNA for decorin were also lower (mean 59 +/- 28%; P < 0.02, n = 7) but those for biglycan and versican were not significantly different. Four pairs of cell strains were examined at more than one passage and the differences in decorin protein were found to be phenotypically persistent. Treatment of confluent cultures with transforming growth factor-beta 1 for 3 days caused a reduction in both decorin protein and mRNA in all six strains of hypertrophic scar fibroblasts tested and in five of six strains of normal dermal fibroblasts. An increase in the length of the dermatan sulphate chain on decorin, a previously reported characteristic of this glycosaminoglycan in hypertrophic scar, was seen in all but two of the strains treated with transforming growth factor-beta 1. The depression of decorin synthesis by transforming growth factor-beta 1 was reversed on removal of the agent and passaging the fibroblasts. 3. The reduced capacity of fibroblasts in hypertrophic scar tissue to synthesize decorin may have implications for the development of the condition since this small proteoglycan is involved in tissue organization and may also play a role in modulating the activity in vivo of fibrogenic cytokines such as transforming growth factor-beta 1.

Induction of transforming growth factor beta 1 by insulin-like growth factor-1 in dermal fibroblasts

Transforming growth factor beta1 (TGF-beta1) belongs to a family of multifunctional modulatory proteins involved in cell growth, differentiation, development, and wound healing. Although the biological activities of TGF-beta1 have been extensively studied, its regulation remains obscure. Here we report the effects of insulin-like growth factor-1 (IGF-1) on the expression of TGF-beta1 by dermal fibroblasts and suggest a possible mechanism. An enzyme-linked immunosorbent assay (ELISA) specific for TGF-beta revealed a greater than twofold increase (12.3 +/- 1.6 vs. 4.8 +/- 0.8 pg/10(4) cells, n = 7, P < 0.05) in the protein in conditioned medium obtained from IGF-1-treated cells compared to that from untreated controls. Similar results were obtained by the mink lung epithelial cell growth inhibition assay. The results of Northern analysis revealed a dose-dependent increase in TGF-beta1 mRNA in response to IGF-1 treatment. Using the optimum concentration of IGF-1 (100 ng/ml), a greater than twofold increase (25.43 +/- 5.7 vs. 12.13 +/- 4.5, P < 0.05) in TGF-beta1 mRNA was observed. This effect persisted for at least 48 h after IGF-1 was removed from the culture medium. Nuclear run-on assay showed that this stimulation was due, at least in part, to an increase in the rate of transcription of the TGF-beta1 gene. Treatment of human dermal fibroblasts with IGF-1 caused a substantial increase in c-fos and c-jun mRNA expression within 30 and 60 min, respectively. In contrast to c-jun mRNA which was constitutively expressed by dermal fibroblasts, the expression of c-fos mRNA was transient and only detectable between 15 and 60 min. Greater than 58% of the increase in TGF-beta1 caused by IGF-1 could be blocked by the addition of anti-TGF-beta1 neutralizing antibody to the culture medium, suggesting that autoinduction of TGF-beta1 may be involved. An increase in IGF-1-induced TGF-beta1 should be important in many different physiological processes such as cellular proliferation, differentiation, and wound healing. These findings also suggest that induction of TGF-beta1 mRNA and protein by IGF-1 may be a mechanism by which this cytokine is regulated in physiological and/or pathological conditions.

Soluble myelin-associated glycoprotein (MAG) found in vivo inhibits axonal regeneration

Myelin-associated glycoprotein (MAG) is a potent inhibitor of axonal regeneration when used as a substrate for growth. However, to be characterized definitively as inhibitory rather than nonpermissive, MAG must also inhibit axonal regeneration when presented in solution. Here, we show that soluble dMAG (extracellular domain only), released in abundance from myelin and found in vivo and chimeric MAG-Fc, can potently inhibit axonal regeneration. For both dMAG and MAG-Fc, inhibition is dose-dependent. If myelin-conditioned medium is immunodepleted of dMAG, or if a MAG antibody is included with MAG-Fc, inhibition is completely neutralized. Together with MAG's ability to induce growth cone collapse, these results demonstrate that MAG is an inhibitory molecule and not merely nonpermissive. The results also suggest that MAG binds to a specific receptor and initiates a signal transduction cascade to effect inhibition. Importantly, these results indicate that soluble dMAG detected in vivo could contribute to the lack of regeneration in the mammalian CNS after injury.