Dietary intake of benzo(a)pyrene and risk of esophageal cancer in north of Iran

One etiologic factor for high incidence of esophageal squamous cell carcinoma (ESCC) in Golestan (Northeastern Iran) might be exposure to polycyclic aromatic hydrocarbons. We examined whether food and water are major sources of benzo(a)pyrene (BaP) exposure in this population. We used a dietary questionnaire to assess the daily intake of staple food (rice and bread) and water in 3 groups: 40 ESCC Golestan cases, 40 healthy subjects from the same area, and 40 healthy subjects from a low-risk area in Southern Iran. We measured, by high-performance liquid chromatography combined with fluorescence detection, the BaP concentration of bread, rice, and water in samples obtained from these 3 groups and calculated the daily intake of BaP. Mean BaP concentration of staple foods and water was similar and within standard levels in both areas, but the daily intake of BaP was higher in controls from the high-risk area than in controls from the low-risk area (91.4 vs. 70.6 ng/day, P < 0.01). In the multivariate regression analysis, having ESCC had no independent effect on BaP, whereas residence in the low-risk area was associated with a significant decrease in total BaP intake. Polycyclic aromatic hydrocarbons might, along with other risk factors, contribute to the high risk of ESCC in Golestan.     

A randomized, placebo-controlled clinical trial of intravitreal triamcinolone for refractory diabetic macular edema

Purpose To evaluate the effect of intravitreal triamcinolone acetonide (IVT) on refractory diabetic macular edema (DME). Methods In a prospective, placebo-controlled, randomized clinical trial, 88 eyes of 61 patients with clinically significant macular edema that would have responded unfavourably to laser photocoagulation were randomly assigned to two groups. The treatment group (45 eyes) received 4 mg IVT and the control group (43 eyes) received a placebo subconjunctival injection. The primary outcome was central macular thickness (CMT) measured by optical coherence tomography. Complete examination was repeated at 2 and 4 months post-intervention. Results The mean (SD) CMT before the intervention and at the 2- and 4-month follow-ups was 393 (151), 293 (109) and 362 (119) μm in the treatment group and 393 (166), 404 (134) and 405 (160) μm in the placebo group, respectively. The second month difference was significant (P = 0.01). The difference between visual acuity changes (0.15 logarithm of the minimum angle of resolution, logMAR) was significant at 2 months (P = 0.02) but reduced to 0.11 logMAR (P = 0.08) after 4 months. Reduction for hard exudates and petaloid pattern were significantly greater in cases at 4 months. Conclusions The therapeutic effect of IVT on DME is greatest at 2 months and decreases up to the fourth month post-intervention. However, in terms of cystoid macular edema and hard exudates, the effect is maintained up to 4 months.     

Fractional photothermolysis: a review and update

Fractional resurfacing is a new laser treatment modality that creates numerous microscopic thermal injury zones of controlled width, depth, and density that are surrounded by a reservoir of spared epidermal and dermal tissue, allowing for rapid repair of laser-induced thermal injury. This unique modality, if implemented with proper laser-delivery systems, enables high-energy treatments while minimizing risks. In this article, we review the various fractional laser devices, including the new fractional ablative devices, as well as the results of studies on the clinical efficacy of fractional photothermolysis. This technology offers patients significant clinical improvement in photodamage, melasma, and scarring with modest treatment-related downtime and minimal risk of complications.     

NGFR (p75) expression in cutaneous scars; Further evidence for a potential pitfall in evaluation of reexcision scars of cutaneous neoplasms, in particular desmoplastic melanoma

Desmoplastic melanoma is a rare variant of malignant melanoma composed of spindle cells in a collagenous matrix. The antibody against NGFR (low affinity nerve growth factor receptor, also known as p75) stains cells of desmoplastic melanoma with high sensitivity; however, the specificity of this marker is not well established. Although there are established histologic criteria for recognition of desmoplastic melanoma, the evaluation of residual disease in cutaneous reexcision scars can be challenging. If residual spindle cells in scar are sufficiently atypical and NGFR positive, their presence could be interpreted as residual desmoplastic melanoma. In this study, we reevaluated the use of antibody against NGFR to detect residual disease in reexcision specimens of melanocytic neoplasms as the previously published works are contradictory. Our data indicate that anti-NGFR antibody stains many cells in the scar, some of which seem to be myofibroblasts, nerve twigs, and Schwann cells. Our findings further suggest that NGFR is not a suitable marker to evaluate reexcision scars for desmoplastic melanoma, especially as a sole marker, as its specificity is low.     

Incomplete Closure of the Left Atrial Appendage: Implication and Management

Incomplete left atrial appendage closure (LAAC) occurs in ～30–40 % of cases following both surgical and percutaneous closure methods. Incomplete surgical LAAC may further be classified as incompletely surgically ligated LAA (ISLL) or LAA stump. ISLL is associated with a significantly increased risk of thrombus formation/thromboembolism. Moreover, this risk is highest in the absence of oral anticoagulation (OAC) and inversely correlates with the size of the ISLL neck. Not only routine screening for ISLL seems critical, but also long-term OAC should strongly be considered in this high-risk cohort. Alternatively, complete endocardial occlusion using a surrogate method may represent a reasonable option, particularly in those intolerant to long-term OAC therapy. Although thrombus formation/thromboembolic events have also been described in patients with incomplete LAAC following percutaneous occlusion, an association between the two remains less clear. However, given the rise and growing interest in percutaneous LAAC methods, additional research in this area is clearly warranted.     

Downregulation of Cockayne syndrome B protein reduces human 8-oxoguanine DNA glycosylase-1 expression and repair of UV radiation-induced 8-oxo-7,8-dihydro-2'-deoxyguanine

Human 8-oxoguanine DNA glycosylase-1 (hOGG1) is the key DNA repair enzyme responsible for initiating repair of UV radiation-induced 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG). Previously we have shown that basal cells in human epidermis are particularly sensitive to UVA-mediated DNA damage probably due to low expression of hOGG1. Here we investigate some aspects of the regulatory role of Cockayne syndrome B (CSB) on hOGG1 expression and function. Cockayne syndrome B and hOGG1 genes were knocked down by miRNA technology in the HaCaT human keratinocyte cell line. Loss of the CSB gene decreased hOGG1 mRNA, and loss of hOGG1 increased CSB, indicating that they influence each other's expression. Protein levels were assessed in cells grown into engineered human skin using immunohistochemistry. This confirmed that CSB knockdown with miRNA reduced hOGG1 protein levels, but hOGG1 knockdown did not influence expression of CSB protein. Using comet assay we found that both hOGG1 and CSB knockdown reduced repair of both UVA- and UVB-induced 8-oxo-dG, consistent with CSB downregulation of hOGG1 mRNA and protein. In contrast, CSB but not hOGG1 knockdown reduced repair of UVB- and UVA-induced cyclobutane pyrimidine dimer photolesions. In engineered human skin, repair of UVA-induced 8-oxo-dG was inhibited by both hOGG1 and CSB knockdown, confirming the functional role of both proteins in cells with 3-D cellular contacts. These findings directly indicate that hOGG1 and CSB influence each other's expression. CSB is required for maintaining hOGG1 enzyme levels and function. Cockayne syndrome B could therefore be required for 8-oxo-dG repair due to its regulatory effect on hOGG1 expression. Cockayne syndrome B but not hOGG1 is also required for efficient repair of cyclobutane pyrimidine dimers. Cockayne syndrome B regulation of DNA repair could contribute to the effect of UVA in causing mutations that lead to skin cancer in humans.