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.

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.

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.

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.

Isoforms of kininogen identified in follicular fluid by 2D-electrophoresis and tandem mass spectrometry

Albumin isoforms unique to the proliferative endometrium identified by 2-dimensional electrophoresis and tandem mass spectrometry

.Quadrupole time of flight mass spectrometric identification of differentially expressed uterine proteins with respect to pregnancy