We recently reported that vanadium (V5+) was able to decrease the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated induction of Cyp1a1 and Nqo1 at mRNA, protein and catalytic activity levels in mouse hepatoma Hepa 1c1c7 and human hepatoma HepG2 cells. However, little is known regarding the in vivo effects. Thus, the objective of this study was to investigate whether similar effects would occur at the in vivo level. Therefore, we examined the effect of exposure to V5+ (5 mg kg−1) with or without TCDD (15 µg kg−1) on the AhR-regulated genes in kidney, lung and heart of C57BL/6 J mice. Our results demonstrated that V5+ alone significantly decreased Cyp1b1 protein and catalytic activity levels in kidney at 24 h. Moreover, it significantly potentiated Nqo1 and Gsta1 gene expression in the heart, and only Gsta1 gene expression in the lung. Upon co-exposure, we found that V5+significantly inhibited the TCDD-mediated induction of Cyp1a1, Cyp1a2 and Cyp1b1 mRNA, protein and catalytic activity levels in the kidney at 24 h. On the other hand, V5+ significantly potentiated the TCDD-mediated induction of Nqo1 and Gsta1 protein and activity levels in the kidney. Cyp1a1, Cyp1b1, Nqo1 mRNA, protein and catalytic activity levels in the lung were significantly potentiated at 6 h. Interestingly, all tested genes in the heart were significantly decreased at 6 h with the exception of Gsta1 mRNA. The present study demonstrates that V5+ modulates TCDD-induced AhR-regulated genes. Furthermore, the effect on one of these enzymes could not be generalized to other enzymes even if it was in the same organ.

NAD(P)H:quinone oxidoreductase (NQO1)-mediated detoxification of quinones plays a critical role in cancer prevention. Heavy metals such as mercury (Hg(2+)) alter the carcinogenicity of aryl hydrocarbon receptor ligands, mainly by modifying various xenobiotic-metabolizing enzymes such as NQO1. Therefore, we examined the effect of Hg(2+) on the expression of NQO1 in human hepatoma HepG2 cells. For this purpose HepG2 cells were incubated with various concentrations of Hg(2+) (2.5, 5, and 10μM) in the presence and absence of two NQO1 inducers, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and isothiocyanate sulforaphane (SUL), as bifunctional and monofunctional inducers, respectively. Analysis of the time-dependent effect of Hg(2+) revealed that Hg(2+) increased the expression of NQO1 mRNA in a time-dependent manner. In addition, Hg(2+) increased NQO1 at the mRNA, protein, and activity levels in the presence and absence of both NQO1 inducers, TCDD and SUL, which coincided with increased nuclear accumulation of Nrf2 protein. Investigating the effect of Hg(2+) at the transcriptional level revealed that Hg(2+) significantly induced the antioxidant-responsive element-dependent luciferase reporter gene expression in the absence and the presence of both NQO1 inducers. NQO1 mRNA and protein decay experiments revealed a lack of posttranscriptional and posttranslational mechanisms. Transfecting HepG2 cells with siRNA for Nrf2 significantly decreased the Hg(2+)-mediated induction of NQO1 mRNA and catalytic activity by approximately 90%. In conclusion, we demonstrated that Hg(2+) regulates the expression of the NQO1 gene through a transcriptional mechanism in human hepatoma HepG2 cells. In addition, Nrf2 is involved in the modulation of NQO1 by Hg(2+).

This is an unusual presentation of complete loosening of an infected femoral component of a knee arthroplasty and expulsion of the metal foreign body out of the body.

Aryl hydrocarbon receptor (AhR) ligands such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and metals, such as mercury (Hg(2+)), are environmental co-contaminants and their molecular interaction may disrupt the coordinated regulation of the carcinogen-activating enzyme cytochrome P450 1A1 (CYP1A1). Therefore, we examined the effect of co-exposure to Hg(2+) and TCDD on the expression of the CYP1A1 in HepG2 cells. Our results showed that Hg(2+) significantly inhibited the TCDD-mediated induction of CYP1A1 at the mRNA, protein, and catalytic activity levels. At the transcriptional level, co-exposure to Hg(2+) and TCDD significantly decreased the TCDD-mediated induction of AhR-dependent luciferase reporter gene expression. Moreover, Hg(2+) did not affect CYP1A1 mRNA stability, while decreasing its protein half-life, suggesting the involvement of a posttranslational mechanism. Importantly, Hg(2+) increased the expression of heme oxygenase-1 (HO-1), a rate limiting enzyme in heme degradation, which coincided with further decrease in the CYP1A1 catalytic activity levels. Upon using a competitive HO-1 inhibitor, tin mesoporphyrin, heme precursor, hemin, or transfecting the HepG2 cells with siRNA for HO-1 there was a partial restoration of the inhibition of TCDD-mediated induction of CYP1A1 catalytic activity. In conclusion, we demonstrate that Hg(2+) down-regulates the expression of CYP1A1 at the transcriptional and posttranslational levels in HepG2 cells. In addition, HO-1 is involved in the modulation of CYP1A1 at the posttranslational level.

Proteomic and molecular studies on the human follicle and follicular fluid: phenotypic differences between human granulosa cell subtypes.

Removal of hardware in orthopaedic surgery is usually encountered in revision fracture surgery for non union, mal union, infection and peri-implant failure. If the hardware has broken this can make revision surgery even more demanding. Numerous techniques have been described to facilitate implant removal. A broken femoral nail is not an uncommon presentation of a delayed union or a non union. We describe a simple and innovative technique to remove the distal portion of broken intramedullary nails without causing any further trauma. This technique can be extended to include most hollow intramedullary nails.

Abstract

The present report concerns a 23-year-old woman who sustained an injury to her right knee while playing 10-pin bowling on a Nintendo Wii video game console. She presented to our orthopaedic outpatients clinic 3 months later with history and examination findings suggestive of a medial meniscal tear, which was confirmed by MRI scan. She underwent arthroscopic partial medial meniscectomy and made an uneventful recovery.

To examine the differences in specific protein expression between mural and cumulus granulosa cells following 24-hour in vitro culture.

DESIGN

Laboratory study.

SETTING

• University Hospital. INTERVENTION(S): Human granulosa cells were collected at the time of egg collection during assisted reproduction. Cumulus cells associated with the oocyte were separated from mural cells from the periphery of the follicle before in vitro culture for 24 hours. Cells were then lysed and subjected to two-dimensional gel electrophoresis. MAIN OUTCOME MEASURE(S): Given that cumulus (cGC) and mural granulosa cells (mGC) differentiate from a single layer, it is likely that phenotypic differences between them may reflect specific molecular processes and structural adaptations. Computer-assisted analysis using dedicated software enabled the presence, absence, or relative volume of each individual protein …

OBJECTIVE: To examine differences in specific protein expression from the surface of the human endometrium with respect to eventual pregnancy in infertile women. DESIGN: Laboratory study. SETTING: University hospital. PATIENT(S): Thirty-one women presenting for investigation into infertility at an assisted reproductive unit. INTERVENTION(S): Endometrial flushings were collected during the proliferative phase of the menstrual cycle and subjected to electrophoretic separation on the basis of isoelectric point and molecular weight. Computerized analysis of the resulting spots was performed, and the proteins were identified using tandem mass spectrometry. MAIN OUTCOME MEASURE(S): The expression of individual isoforms of leucine-rich α2-glycoprotein (LRG) was compared in nonpregnant patients (n = 25), those who became pregnant as a result of treatment (n = 3), and those who had treatment …

Transmissible blood-borne infection can occur at muco-cutaneous membranes. During trauma and orthopaedic surgery, the use of power tools increases spraying of bodily fluid, hence resulting in an increased risk of infectious splash injury to the face. This prospective study involved 25 patients. The visors worn by the operating team were examined postoperatively to identify any visible blood, fat and body tissue splashes. Eleven patients underwent knee arthroplasty. Splash counts to the surgeon’s mouth/lip, nose/cheek and eye regions were 217, 105, and 62 respectively ; they were 258, 147, and 82 for the assistant. Fourteen patients had hip replacement ; splash counts to the surgeon’s mouth/lip, nose/cheek and eye regions were 214, 90, and 53 respectively, and 137, 39 and 27 for the assistant. To conclude, the face is vulnerable to material and fluid strikes during joint arthroplasty surgery. The visor is a reliable barrier to blood, fat and body tissue splashes and minimises the risk of exposure to bloodborne viruses. Therefore, a visor should be worn during all joint arthroplasty procedures and any procedure that involves the use of power tools.