Vitamin D directly regulates Mdm2 gene expression in osteoblasts

While Mdm2 is an important negative regulator of the p53 tumor suppressor, it also possesses p53-independent functions in cellular differentiation processes. Mdm2 expression is alternatively regulated by two P1 and P2 promoters. In this study we show that the P2-intiated transcription of Mdm2 gene is activated by 1,25-dihydroxy vitamin D3 in MC3T3 cells. By using P1 and P2-specific reporters, we demonstrate that only the P2-promoter responds to vitamin D treatment. We have further identified a potential vitamin D receptor responsive element proximal to the two p53 response elements within the Mdm2 P2 promoter. Using cell lines that are p53-temperature sensitive and p53-null, we show requirement of p53 for VDR-mediated up regulation of Mdm2 expression. Our results indicate that 1,25-dihydroxy vitamin D3 and its receptor have a role in the regulation of P2-initiated Mdm2 gene expression in a p53-dependent way.

Platelet activation in patients with atherosclerotic renal artery stenosis undergoing stent revascularization

BACKGROUND AND OBJECTIVES

Soluble CD40 ligand (sCD40L) is a marker of platelet activation; whether platelet activation occurs in the setting of renal artery stenosis and stenting is unknown. Additionally, the effect of embolic protection devices and glycoprotein IIb/IIIa inhibitors on platelet activation during renal artery intervention is unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Plasma levels of sCD40L were measured in healthy controls, patients with atherosclerosis without renal stenosis, and patients with renal artery stenosis before, immediately after, and 24 hours after renal artery stenting.

RESULTS

Soluble CD40L levels were higher in renal artery stenosis patients than normal controls (347.5 ± 27.0 versus 65.2 ± 1.4 pg/ml, P < 0.001), but were similar to patients with atherosclerosis without renal artery stenosis. Platelet-rich emboli were captured in 26% (9 of 35) of embolic protection device patients, and in these patients sCD40L was elevated before the procedure. Embolic protection device use was associated with a nonsignificant increase in sCD40L, whereas sCD40L declined with abciximab after the procedure (324.9 ± 42.5 versus 188.7 ± 31.0 pg/ml, P = 0.003) and at 24 hours.

CONCLUSIONS

Atherosclerotic renal artery stenosis is associated with platelet activation, but this appears to be related to atherosclerosis, not renal artery stenosis specifically. Embolization of platelet-rich thrombi is common in renal artery stenting and is inhibited with abciximab.

Use of electronic medical records to identify patients at risk for prostate cancer in an academic institution

One purported advantage of electronic medical records (EMRs) is to improve patient care. This study uses a search of EMR to identify patients at risk for prostate cancer who were not evaluated by an urologist. The University of Texas Southwestern Medical Center (UTSW) has an institutional outpatient EMR that is used by all providers in all specialties. Since March 2009, all PSA tests were reported with specific interpretative comments including a recommendation for referral to urology for a PSA >2.5 ng ml(-1). All PSA tests were performed on campus since institution of these recommendations were analyzed, and charts reviewed for all patients not seen in urology with a serum PSA >2.5 ng ml(-1). Of the 2884 non-urology patients that had a serum PSA drawn between March 2009 and February 2010 at UTSW, 293 patients had a serum PSA >2.5 ng ml(-1). Of these, 39 patients had known prostate cancer and were seeing an oncologist. There were 59 patients seeing urologists outside the institution. A total of 195 patients were not seen by an urologist and only 11 patients were recommended to see one but did not make an appointment. There were 151 patients with more than one PSA in the system, and of these 103 had a rise in PSA with a median rise of 0.53 ng ml(-1) per year. EMR allows identification of patients at increased risk of prostate cancer who are not evaluated. Prospective studies are needed to identify ways to improve appropriate evaluation and detection of prostate cancer.

A population study of polyurethane foam fragments recovered from the surface of 100 outer-garments

One hundred outer-garments were examined for microscopic fragments of polyurethane foam. Low power stereomicroscopy was used to classify fragments into 18 groups according to macroscopic colour. Amber, pale yellow and black were the most frequently encountered, whilst navy, pale blue, bright pink, beige, brown, pale green, peach and white were the least frequently encountered. High power comparison/fluorescence microscopy was used to discriminate 166 populations within 16 colour groupings. The majority (95.2%) of populations consisted of three fragments or less. This study demonstrates that the background population of foam fragments on an outer-garment consists of low numbers representing various colours. Therefore, finding a large population of microscopically indistinguishable fragments within a casework situation has the potential to be considered highly significant evidentially.