[Influence of SOX10 on the proliferation and invasion of prostate cancer cells]

OBJECTIVE

To explore the influence of SOX10 on the proliferation and invasion of prostate cancer cells.

METHODS

SOX10 protein in prostate cancer cell lines PC3, DU145 and LNcap was detected by Western blotting analysis. The expression of SOX10 in prostate cancer cell lines (PC3 and DU145) were knocked down by small interfering RNAs, and the efficiency of SOX10 by small interfering RNAs was confirmed using Western blotting analysis. CCK-8 assays were conducted to assess the influences of SOX10 on the proliferation of PC3 and DU145 cells, and invasion assays were conducted to assess the influences of SOX10 on the invasion of PC3 and DU145 cells.

RESULTS

After SOX10 in prostate cancer cells was knocked down by small interfering RNAs, the proliferation of prostate cancer cells PC3 and DU145 was significantly inhibited. Results of CCK-8 assays showed that the absorbance of PC3 and DU145 in SOX10-silenced groups was decreased compared with those in control groups (PC3: 0 d: 0.166±0.01, 0.162±0.012 vs. 0.155 ±0.01, P>0.05; 1 d: 0.210±0.011, 0.211±0.018 vs. 0.252±0.023, P>0.05; 2 d: 0.293±0.017, 0.280±0.028 vs. 0.433±0.030, P<0.01; 3 d: 0.363±0.071, 0.411±0.038 vs. 0.754±0.045, P<0.01; 4 d: 0.592±0.065, 0.670±0.093 vs. 1.456±0.111, P<0.01. DU145: 0 d: 0.168±0.018, 0.164±0.01 vs. 0.153 ±0.012, P>0.05; 1 d: 0.218±0.007, 0.206±0.024 vs. 0.255±0.02, P>0.05; 2 d: 0.297±0.013, 0.291±0.012 vs. 0.444±0.023, P<0.05; 3 d: 0.378±0.058, 0.419±0.026 vs. 0.762±0.039, P<0.01; 4 d: 0.681±0.094, 0.618±0.050 vs. 1.419±0.170, P<0.01). Meanwhile, knocking down SOX10 significantly suppressed the invasion of prostate cancer cells PC3 and DU145. Results of invasion assays showed that the numbers of invaded cells in SOX10-silenced groups were significantly less than those in control groups (PC3: 142±38, 171±17 vs. 304±55; DU145: 96±22, 134±23 vs. 341±34, P<0.05).

CONCLUSION

SOX10 might promote prostate cancer progression by accelerating the ability of the proliferation and invasion of prostate cancer cells, and SOX10 might be a potential therapeutic target for prostate cancer.

[Minimal fat renalangiomyolipoma with multiple lymph nodes enlargement and postoperative refractory lymphatic fistula: a case report and literature review]

Renal angiomyolipoma (AML) is a common benign tumor in the urinary system, mainly composed of adipose tissue, blood vessels and muscle tissue. Renal AML is sporadic in most of patients, while a few are associated with tuberous sclerosis. Classical renal AML occurs predominantly in middle-aged females. Most cases are found incidentally during imaging examinations. The fat content makes AML have unique imaging characteristics and is easy to be identified with other renal tumors. However, the amount of fat varies in each tumor. AML that contains only microscopically detectable fat and whose amount of intratumoral fat may be too small to be identified on unenhanced computed tomography (CT) images is termed minimal fat or fat-poor renal AML, which appears as a high density shadow in the renal parenchyma on unenhanced CT images. Thus, it can be difficult to distinguish it from renal cell carcinoma (RCC) on imaging. Since the imaging findings are atypical, the diagnosis depends on pathological results. In addition, a few of AML can mimic malignant neoplasms. Recent studies suggested that AML might involve to peri-renal or renal sinus fat, regional lymphatics and other visceral organs, as well as inferior vena cava, which further makes the diagnosis more difficult. However, there is currently no reports about involvement of regional limphatics in minimal fat renal AML. In this article, we report a 27-year-old female patient without family history of tuberous sclerosis, who came to visit the hematologist because a high density shadow near the left kidney was found during CT scan which was accompanied by neck, armpits, groin, abdominal cavity and retroperitoneal lymph nodes enlargement. She was suspected of lymphoma in the beginning and transferred to Department of Urology to perform laparoscopic left renal mass and retroperitoneal lymph node excision and pathological examination for a definitive diagnosis. Finally, pathologic results revealed AML. Postoperative continuous lymphatic fistula developed and the retroperitoneal drainage of chylous fluid was 100-200 mL per day, lasting for 12 weeks. The fistula was successfully closed after conservative treatment including fasting and rehydration. This article summaries and discusses the diagnosis and treatment of renal AML with lymph nodes enlargement and the management of postoperative refractory lymphatic fistula by reviewing the related cases and literature.

[Expression and localization of transmembrane protein CMTM2 in human testis and sperm]

OBJECTIVE

To study the expression of transmembrane protein CMTM2 in the testis and sperm of adult males and to approach the potential function of the protein in the male reproductive system.

METHODS

The expression of CMTM2 in human testis and sperm was confirmed by Western blot. Immunohistochemical staining was used for detecting CMTM2 localization in the testis tissue, TRITC-CMTM2 and FITC-Hoechst double immunofluorescence staining was performed to examine the subcellular localization of CMTM2 in the human sperm before and after acrosome reaction, that is, immunofluorescent staining was used for detecting CMTM2 localization in both the testis and sperm before and after the acrosome reaction.

RESULTS

CMTM2 was presented in both human testis and sperm. In the testis, CMTM2 immunoreactive particles were observed mainly in the membrane of the different stages of spermatogenic cells. In the human sperm, its immunoreactivity was restrictively localized to the posterior head where sperm-egg fusion occurred, and the CMTM2 localization was not affected by sperm acrosome reaction. CMTM2 was widely expressed in seminiferous tubules of the human testis, mainly in the cell membranes of spermatogenic cells, which was consistent with the previous reports. The immunofluorescence performed on frozen human testis slides showed similar findings with immunohistochemistry, which gave weight to the localization of CMTM2 in the cell membranes of spermatogenic cells at different stages. TRITC-CMTM2 and FITC-Hoechst double immunofluorescence staining was performed to examine the subcellular localization of CMTM2 in the human sperm before and after acrosome reaction. CMTM2 was localized at the posterior head of sperm before and after acrosome reaction. The localization and expression of CMTM2 were not affected by sperm acrosome reaction.

CONCLUSION

Expression of CMTM2 in the male reproductive system of the adult human exhibits cell- and region-specific patterns, which suggests that they may play an important role in spermatogenesis and sperm-egg fusion. The expression of CMTM2 in the male reproductive system of the adult human exhibits cell- and region-specific patterns, which suggests that they may play an important role in spermatogenesis and sperm-egg fusion. However, it still remains to be further elucidated about the definite role of CMTM2 in male reproductive system and the process of spermatogenesis. And in vitro fertilization experiments are needed to confirm the role of CMTM2 in fertilization in future.

[Expression of chemokine like factor-like myelin and lymphocyte and related proteins for vesicle trafficking and membrane link transmembrane domain-containing protein 2 in rats with varicocele]

OBJECTIVE

To investigate whether chemokine like factor (CKLF)-like myelin and lymphocyte and related proteins for vesicle trafficking and membrane link (MARVEL) transmembrane domain-containing protein 2 (CMTM2) is involved in spermatogenesis in varicocele induced subfertility rats and to discuss the possible mechanisms.

METHODS

Forty male SD rats (body weight: 220-330 g, age: 6-7 weeks) were randomly divided into 4 groups: varicocele for 4 weeks, varicocele for 12 weeks, sham operation for 4 weeks and sham operation for 12 weeks, with 10 rats in each group. These rats were introduced by partially ligating left kidney veins for the experimental groups, and the sham surgery groups as controls were executed with exactly the same surgery as in the experimental groups except for the ligation. The rats in control and experimental groups for 4 and 12 weeks were killed after laparotomy at the end of 4 and 12 weeks, respectively, the left testes and epididymis were taken out for counting the sperm, observing the seminiferous tubule change and immunochemistry for CMTM2. The changes included sperm density and motility, the outer diameter and inner diameter change and the changes of epithelium and the CMTM2 expression in immunochemistry.

RESULTS

Compared with the control groups, the sperm density [(63.9±7.1)×10⁶/mL vs.(74.3±5.0)×10⁶/mL] and motility [(58.7%±7.9%) vs.(66.1%±4.3%)] were reduced slightly in group of varicoele for 4 weeks, respectively (t=1.432, 1.563; P=0.076, 0.059, respectively). Varicocele significantly caused a decrease in sperm concentration [(40.5±7.2) ×10⁶/mL vs.(71.1±4.5)×10⁶/mL] and motility [(35.2%±8.5%)vs. (63.4%±4.1%)] at 12 weeks, compared with the related sham groups (t=3.754, 3.933; P=0.004, 0.002, respectively). Additionally, testis CMTM2 exhibited the same disparity, that is, the CMTM2 protein expression in varicocele group was significantly reduced, with the ratio of sham group to varicocele group at the end of 12 weeks 2.3±0.4 (t=1.978; P=0.039). In the evaluation of seminiferous tubules diameter, the external [(198.2±10.2) μm vs. (255.8±12.7) μm, t=2.125, P=0.003] and epithelium diameter [(54.1±1.5) μm vs. (75.5±4.1) μm, t=2.246, P=0.021] were decreased compared with the sham-related groups and previous varicocele groups. In all the varicocele groups, all types of sperm motility decreased compared with the related sham-operated group (P<0.05).

CONCLUSION

This study suggests varicocele has a detrimental effect on CMTM2 levels and decreases spermatogonia cell number, seminiferous tubules diameter, and sperm indices. CMTM2 is associated with sperm changes in rats with varicocele, and further studies are needed to study the mechanism.

[Knockdown of CMTM3 promotes migration and invasion of PC3 cell in vitro]

OBJECTIVE

To investigate the change of biological characteristics after stable knockdown of CKLF-like MARVEL transmembrane domain containing 3 (CMTM3) expression in PC3 by lentivirus shRNA and to reveal new therapeutic targets.

METHODS

The research includes two groups: sh393 is the experimental group in which CMTM3 is knocked down in PC3 cell line; shN is the control group in which CMTM3 is negatively knocked down. The expression of CMTM3 was detected by Western blot. The migration ability of PC3 after stable knockdown was detected by Transwell and Wound healing assay. The invasion ability of PC3 was detected by Matrigel assay. RESULTS were obtained from at least three individual experiments.

RESULTS

The expression of CMTM3 in sh393 group is significant lower than shN group (0.004 0±0.000 4 vs. 0.490 0±0.055 7, P<0.001) detected by Western blot. It also had statistical significance in Matrigel assays (248.6±4.5 vs. 113.0± 3.3), Transwell (203.6±1.9 vs. 103.0±1.2) and Wound healing assays (95.0±2.9 vs. 33.0±1.5) that knockdown of CMTM3 promoted migration, and invasion of PC3 cells in vitro (P<0.001).

CONCLUSION

Negative correlation exists between the stable knockdown of CMTM3 and change of biological characteristics in PC3 cells, and knocking down CMTM3 affects migration, and invasion ability in PC3 cells.

[Expression of MEK/ERK signal pathways in renal cell carcinoma with bone metastasis]

OBJECTIVE

To investigate the expression of MEK/ERK signaling pathways in renal cell carcinoma with bone metastasis, and to analyze the differences of expressions of VEGFR-2, MEK, ERK on the primary and metastasis tissue and its mechanism.

METHODS

The tissue samples were obtained from 7 renal cell carcinoma patients kindly provided by Department of Urology, Peking University People's Hospital from January 1, 2009 to January 1, 2010. The expression of MEK/ERK signaling pathways was detected in the 7 renal cell carcinoma patients` primary and matched metastatic tissues with ICH, The antibody concentrations were 1:200, 1:25, and 1:250, respectively. The mutation of the twentieth exon of the PDGFRA gene, the second exon of the K-ras gene, the fifteenth exon of the Braf gene and the second exon of the MEK1 gene were detected with PCR.

RESULTS

The expression intensities of VEGFR-2, MEK, and ERK were measured by H-score [intensity (1, 2, 3, or 4) multiplied by the distribution (%)]. VEGFR-2, MEK, and ERK expressions were divided into 3 groups according to the positive distribution of the tumor cells: 1, 0-5%; 2, 6%-50%; and 3, >50%, To assess intratumor heterogeneity, three distinct microscopic fields (×200) from each specimen were used to evaluate the expressions, Subsequently, the scores were averaged to obtain a single concatenated score for each tissue. VEGFR-2, MEK, and ERK expressions were assessed by 2 independent pathologists who were blinded to the clinicopathological data. The data were expressed as the mean value of the triplicate experiments. The expressions of MEK, and ERK were higher in the metastatic tissues than in the matched RCC tissues (6.10±4.10 vs. 1.33±0.51, P=0.015; 9.10±2.24 vs. 4.43± 2.84, P=0.021) while the expression of VEGFR-2 was not different between the primary and metastatic tissues (P=0.901). No mutation was detected on the twentieth exon of the PDGFRA gene, the second exon of the K-ras gene, the fifteenth exon of the Braf gene and the second exon of the MEK1 gene.

CONCLUSION

MEK/ERK signaling pathways may play an important role in the metastasis and the resistance of sunitinib in RCC patients with bone metastasis.

Eremophilane sesquiterpenes from Hawaiian endophytic fungus Chaetoconis sp. FT087

Seven sesquiterpene derivatives, including chaetopenoids A-F and dendryphiellin A1, and 6-methyl-(2E, 4E, 6S) octadienoic acid were isolated from the culture broth of Chaetoconis sp. FT087. Their structures were determined through the analysis of HRMS and NMR spectroscopic data. The absolute configurations of chaetopenoids A-D were elucidated by comparison of their CD and optical rotation data with those in the literature. Chaetopenoids A-C and E belong to the eremophilane type of sesquiterpenoids, while chaetopenoids D and F and dendryphiellin A1 have a trinor-eremophilane skeleton. All compounds were tested against A2780 and cisplatin resistant A2780CisR cell lines, and dendryphiellin A1 was moderately active with IC50 values of 6.6 and 9.1 μg/mL, respectively.

[Knockdown of CMTM3 promotes migration and invasion of PC3 cell in vitro]

OBJECTIVE

To investigate the change of biological characteristics after stable knockdown of CKLF-like MARVEL transmembrane domain containing 3 (CMTM3) expression in PC3 by lentivirus shRNA and to reveal new therapeutic targets.

METHODS

The research includes two groups: sh393 is the experimental group in which CMTM3 is knocked down in PC3 cell line; shN is the control group in which CMTM3 is negatively knocked down. The expression of CMTM3 was detected by Western blot. The migration ability of PC3 after stable knockdown was detected by Transwell and Wound healing assay. The invasion ability of PC3 was detected by Matrigel assay. RESULTS were obtained from at least three individual experiments.

RESULTS

The expression of CMTM3 in sh393 group is significant lower than shN group (0.004 0±0.000 4 vs. 0.490 0±0.055 7, P<0.001) detected by Western blot. It also had statistical significance in Matrigel assays (248.6±4.5 vs. 113.0± 3.3), Transwell (203.6±1.9 vs. 103.0±1.2) and Wound healing assays (95.0±2.9 vs. 33.0±1.5) that knockdown of CMTM3 promoted migration, and invasion of PC3 cells in vitro (P<0.001).

CONCLUSION

Negative correlation exists between the stable knockdown of CMTM3 and change of biological characteristics in PC3 cells, and knocking down CMTM3 affects migration, and invasion ability in PC3 cells.

[Expression of MEK/ERK signal pathways in renal cell carcinoma with bone metastasis]

OBJECTIVE

To investigate the expression of MEK/ERK signaling pathways in renal cell carcinoma with bone metastasis, and to analyze the differences of expressions of VEGFR-2, MEK, ERK on the primary and metastasis tissue and its mechanism.

METHODS

The tissue samples were obtained from 7 renal cell carcinoma patients kindly provided by Department of Urology, Peking University People's Hospital from January 1, 2009 to January 1, 2010. The expression of MEK/ERK signaling pathways was detected in the 7 renal cell carcinoma patients` primary and matched metastatic tissues with ICH, The antibody concentrations were 1:200, 1:25, and 1:250, respectively. The mutation of the twentieth exon of the PDGFRA gene, the second exon of the K-ras gene, the fifteenth exon of the Braf gene and the second exon of the MEK1 gene were detected with PCR.

RESULTS

The expression intensities of VEGFR-2, MEK, and ERK were measured by H-score [intensity (1, 2, 3, or 4) multiplied by the distribution (%)]. VEGFR-2, MEK, and ERK expressions were divided into 3 groups according to the positive distribution of the tumor cells: 1, 0-5%; 2, 6%-50%; and 3, >50%, To assess intratumor heterogeneity, three distinct microscopic fields (×200) from each specimen were used to evaluate the expressions, Subsequently, the scores were averaged to obtain a single concatenated score for each tissue. VEGFR-2, MEK, and ERK expressions were assessed by 2 independent pathologists who were blinded to the clinicopathological data. The data were expressed as the mean value of the triplicate experiments. The expressions of MEK, and ERK were higher in the metastatic tissues than in the matched RCC tissues (6.10±4.10 vs. 1.33±0.51, P=0.015; 9.10±2.24 vs. 4.43± 2.84, P=0.021) while the expression of VEGFR-2 was not different between the primary and metastatic tissues (P=0.901). No mutation was detected on the twentieth exon of the PDGFRA gene, the second exon of the K-ras gene, the fifteenth exon of the Braf gene and the second exon of the MEK1 gene.

CONCLUSION

MEK/ERK signaling pathways may play an important role in the metastasis and the resistance of sunitinib in RCC patients with bone metastasis.

[Expression of chemokine like factor-like myelin and lymphocyte and related proteins for vesicle trafficking and membrane link transmembrane domain-containing protein 2 in rats with varicocele]

OBJECTIVE

To investigate whether chemokine like factor (CKLF)-like myelin and lymphocyte and related proteins for vesicle trafficking and membrane link (MARVEL) transmembrane domain-containing protein 2 (CMTM2) is involved in spermatogenesis in varicocele induced subfertility rats and to discuss the possible mechanisms.

METHODS

Forty male SD rats (body weight: 220-330 g, age: 6-7 weeks) were randomly divided into 4 groups: varicocele for 4 weeks, varicocele for 12 weeks, sham operation for 4 weeks and sham operation for 12 weeks, with 10 rats in each group. These rats were introduced by partially ligating left kidney veins for the experimental groups, and the sham surgery groups as controls were executed with exactly the same surgery as in the experimental groups except for the ligation. The rats in control and experimental groups for 4 and 12 weeks were killed after laparotomy at the end of 4 and 12 weeks, respectively, the left testes and epididymis were taken out for counting the sperm, observing the seminiferous tubule change and immunochemistry for CMTM2. The changes included sperm density and motility, the outer diameter and inner diameter change and the changes of epithelium and the CMTM2 expression in immunochemistry.

RESULTS

Compared with the control groups, the sperm density [(63.9±7.1)×10(6)/mL vs.(74.3±5.0)×10(6)/mL] and motility [(58.7%±7.9%) vs.(66.1%±4.3%)] were reduced slightly in group of varicoele for 4 weeks, respectively (t=1.432, 1.563; P=0.076, 0.059, respectively). Varicocele significantly caused a decrease in sperm concentration [(40.5±7.2) ×10(6)/mL vs.(71.1±4.5)×10(6)/mL] and motility [(35.2%±8.5%)vs. (63.4%±4.1%)] at 12 weeks, compared with the related sham groups (t=3.754, 3.933; P=0.004, 0.002, respectively). Additionally, testis CMTM2 exhibited the same disparity, that is, the CMTM2 protein expression in varicocele group was significantly reduced, with the ratio of sham group to varicocele group at the end of 12 weeks 2.3±0.4 (t=1.978; P=0.039). In the evaluation of seminiferous tubules diameter, the external [(198.2±10.2) μm vs. (255.8±12.7) μm, t=2.125, P=0.003] and epithelium diameter [(54.1±1.5) μm vs. (75.5±4.1) μm, t=2.246, P=0.021] were decreased compared with the sham-related groups and previous varicocele groups. In all the varicocele groups, all types of sperm motility decreased compared with the related sham-operated group (P<0.05).

CONCLUSION

This study suggests varicocele has a detrimental effect on CMTM2 levels and decreases spermatogonia cell number, seminiferous tubules diameter, and sperm indices. CMTM2 is associated with sperm changes in rats with varicocele, and further studies are needed to study the mechanism.

A New Metabolite with a Unique 4-Pyranone-γ-Lactam-1,4-Thiazine Moiety from a Hawaiian-Plant Associated Fungus

An endophytic fungus Paraphaeosphaeria neglecta FT462 isolated from the Hawaiian-plant Lycopodiella cernua (L.) Pic. Serm produced one unusual compound (1, paraphaeosphaeride A) with the 4-pyranone-γ-lactam-1,4-thiazine moiety, along with two new compounds (2 and 3, paraphaeosphaerides B and C, respectively) and the known compound (4). Compounds 1-3 were characterized by NMR and MS spectroscopic analysis. The absolute configuration of the 3-position of compound 1 was determined as S by electronic circular dichroism (ECD) calculations. Compound 3 also showed STAT3 inhibition at 10 μM.

A new sesquiterpene lactone with sulfonic acid group from Saussurea lappa

A new sesquiterpene lactone with an unusual sulfonic acid group, 13-sulfo-dihydrodehydrocostus lactone (1), was isolated from the roots of Saussurea lappa C. (Compositae), together with a known lignan (2). The structure of 1 was characterized on the basis of spectral evidence including 2DNMR studies. Compound 2 was obtained from this plant for the first time.

A new monoterpene from the bark of Eucommia ulmoides

A new monoterpene, eucommidiol (1), was isolated from the bark of Eucommia ulmoides Oliv. (Eucommiaceae), together with a known compound 1,4a,5,7a-tetrahydro-7-hydroxymethyl-cyclopenta[c]pyran-4-carboxylic methyl ester. The structure of 1 was characterized as 6,6a-di(hydroxymethyl)-3,3a,4,6a-tetrahydro-2H-cyclopenta[b]furan-2-one on the basis of chemical and spectral evidence including 2DNMR studies.

Biological characterization of a novel biodegradable antimicrobial polymer synthesized with fluoroquinolones

Biomaterial-related infections continue to represent a significant challenge to the medical community. Several approaches have been utilized to incorporate antimicrobial agents at the surface of implant devices in attempts to delay or eliminate the formation of biofilms. To date, most of these strategies have focused on drug conjugation or diffusion-limited systems for the delivery of such pharmaceutical agents. More recently, work has been presented on the feasibility of incorporating drugs into the backbone of polymers as a main-chain monomer. When sequenced into the backbone of the polymer with other monomers that are hydrolytically sensitive to enzyme-catalyzed breakdown, it is thought that drugs may be able to be selectively released. Specifically, degradable polyurethanes have been synthesized with fluoroquinolone antibiotics and have shown an ability to kill bacteria when released following degradation of the polymer chains by the macrophage-derived enzyme cholesterol esterase. However, specificity of the cleavage sites in the polymer was difficult to control. Since cholesterol esterase has specificity for hydrophobic moieties, it is desirable to alter the formulation of the polyurethanes to incorporate long hydrophobic monomers immediately adjacent to the ciprofloxacin molecule. Hence, the current study focuses on evaluating the enzyme-catalyzed degradation of a degradable polyurethane synthesized with 1,12 diisocyanatododecane as a substitute for 1,6 diisocyanatohexane, which was used in previous work. Validation of specific ciprofloxacin release and the generation of antimicrobial are shown. A preliminary cell study to assess the cytotoxicity of this biodegradable antibiotic polymer shows that the material has no observable effects on cell proliferation or cell membrane structure.

Blood interactions with plasticized poly(vinyl chloride): relevance of plasticizer selection

An investigation has been made of blood interactions with plasticized poly(vinyl chloride) (PVC) biomaterials in tubular form, taking into account the influence on the blood response of the polymer, antithrombotic agent, blood condition and test procedure. In vitro and ex vivo procedures were used to achieve a comparison between PVC plasticized with di- (2-ethylhexyl)phthalate (DEHP) and with tri-(2-ethylhexyl)trimellitate (TEHTM). The blood response was monitored in terms of the measurement of fibrinogen adsorption capacity, thrombin-antithrombin III complex (TAT) and the complement component C3a. Surface characterization of the polymers was performed by X-ray photoelectron spectroscopy (XPS). The data obtained indicate that in comparison with DEHP-PVC, there is a higher reactivity for TEHTM-PVC, which correlates with the plasticizer distribution at the polymer surface.

Comparative evaluation of the antimicrobial activity of ACTICOAT antimicrobial barrier dressing

This study evaluated the antimicrobial activity of ACTICOAT Antimicrobial Barrier Dressing (Westaim Biomedical Corp, Fort Saskatchewan, Alberta, Canada), a silver-coated wound dressing, and compared it with silver nitrate, silver sulfadiazine, and mafenide acetate. The minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC), zone of inhibition, and killing curves were determined with 5 clinically relevant bacteria. The data indicate that ACTICOAT silver had the lowest MIC and MBC and generated similar zones of inhibition to silver nitrate and silver sulfadiazine. Viable bacteria were undetectable 30 minutes after inoculation with the dressing, whereas it took 2 to 4 hours for silver nitrate and silver sulfadazine to achieve the same result. Mafenide acetate generated the biggest zones of inhibition, but it had the highest MICs and MBCs, and a significant number of bacteria still survived after 6 hours of treatment. The results suggest that ACTICOAT Antimicrobial Barrier Dressing has better antimicrobial performance than either of the existing silver-based products. ACTICOAT dressing killed the bacteria that were tested much faster, which is a very important characteristic for a wound dressing acting as a barrier to invasive infection to have. The study also suggests that a single susceptibility test such as a MIC or zone of inhibition test does not provide a comprehensive profile of antimicrobial activity of a topical antimicrobial agent or dressing. A combination of tests is desirable.

In vitro blood compatibility evaluation of hollow fibre membrane using a controlled flow system: a comparative study

A procedure has been established for the in vitro assessment of hollow fibre haemodialysis membranes. A 30 ml syringe containing 20 ml of fresh non-anticoagulated blood was mounted onto a non-pulsatile syringe pump and blood was perfused through minimodules constructed from 80 fibres retrieved from Cuprophan (Baxter ST15), cellulose acetate (M57-12, JMS Co Ltd, Hiroshima, Japan), and AN69HF (Filtral 20, Hospal, France) dialysers. Samples were collected before perfusion, 3, 6, 9 and 12 minutes. The modules were clamped vertically to minimise the effect of red cell pooling and the dialysate compartment was filled with 0.9% saline to minimise ultrafiltration. After sample processing, complement C3a, thrombin-antithrombin III complexes, prothrombin F1 + 2, and factor XII-like activity were evaluated. The results indicated that the system could discriminate between the membranes evaluated and therefore was a relevant procedure for the assessment of hollow fibre haemodialysis membranes.

The influence of biomaterials on inflammatory responses to cardiopulmonary bypass

The nature of cardiopulmonary bypass and the complexity of the inflammatory response make the detection and interpretation of a biomaterial influence difficult. However, if mediation of the inflammatory response is considered to be an appropriate clinical goal, alteration to the biomaterial influence merits further investigation.

Thrombin-treated endothelium primes neutrophil functions: inhibition by platelet-activating factor receptor antagonists

We have shown previously that fluid phase platelet-activating factor (PAF) can enhance or "prime" polymorphonuclear (PMN) responses to subsequent stimulation with agonists such as formyl-methionine-leucine-phenylalanine (FMLP). Since thrombin induces PAF production in endothelial cells, we tested whether this thrombin-provoked endothelial PAF primes responses of marginated PMNs. Monolayers of human umbilical vein endothelial cells were exposed to either thrombin (0.5-5.0 units/ml) or buffer for up to 5 min and then PMNs were layered on top of the endothelial cells. After a further 5 min incubation, the PMNs were stimulated with a suboptimal concentration of FMLP (10(-7) M), and their superoxide production, elastase release, adhesion to endothelium, and capacity to cause endothelial cell lysis and detachment were assessed. Thrombin pretreatment significantly enhanced each of these FMLP-stimulated neutrophil responses. The extent of this enhancement correlated with both the dose and duration of thrombin treatment of endothelial cells and also the duration of PMN incubation with thrombin-exposed endothelium. Evidence that the augmentation was due to endothelial-derived PAF was obtained as follows: (1) thrombin induced [3H]acetate incorporation into endothelial PAF (assayed in lipid extracts); (2) antithrombin III conjointly inhibited this [3H]acetate uptake and prevented the priming effect of thrombin-treated endothelium on PMN responses; and (3) the PAF receptor antagonist BN52021, when preincubated with PMNs, also effectively blocked the enhancement of PMN responses. We conclude that thrombin stimulation of endothelial cells initiates a sequence of events culminating in the production of PAF--a membrane phospholipid capable of priming marginated PMNs. We suggest that this coagulation-fostered endothelial/PMN interaction may underlie a paracrine response that may potentiate PMN-mediated endothelial injury during sepsis and other thrombin-generating disorders.

Platelet-activating factor primes neutrophil responses to agonists: role in promoting neutrophil-mediated endothelial damage

During inflammation polymorphonuclear cells (PMNs) are exposed to agonistic stimuli including activated complement, kallikrein, arachidonic acid metabolites, monokines, and platelet-activating factor (PAF). We report that PAF not only directly activates PMNs but in miniscule quantities (10(-12) mol/L) "primes" them as well, that is, permits PMNs to respond to subsequent stimuli that would be otherwise ineffectual. PAF priming of responses including superoxide generation, elastase release, and aggregation is time dependent and is maximal within five minutes. PAF need not be present during the subsequent exhibition of PMN agonists, but priming is inhibited by cold and is also inhibited by the PAF receptor antagonists BN 52021, L-652, and kadsurenone. An intact PAF molecule is required because lyso-PAF and methoxy-PAF do not prime PMN responses. PAF priming is associated with both enhanced expression of the adhesive glycoprotein identified by OKM-1 antibody and an enhanced rise in intracellular calcium levels in response to the subsequent addition of agonists such as FMLP. PMNs primed with PAF and stimulated with either F-Met-Leu-Phe or phorbol esters are more effective in lysing and detaching cultured human endothelial cells--damage that can also be inhibited by the PAF antagonists. Because PAF is synthesized and exhibited on surfaces of endothelial cells perturbed by coagulation, we suggest that this lipid may potentiate otherwise trivial activators of marginated PMNs so that they become damaging to the PAF-synthesizing endothelium itself. If so, our studies suggest a possible therapeutic role for PAF inhibitors in excessive inflammatory states.