Irritant hand dermatitis in health care workers

BACKGROUND

Health care workers (HCWs) are at increased risk of irritant contact dermatitis due to frequent hand washing and use of alcohol gel. This has increased the incidence of occupational skin diseases.

AIMS

To evaluate hand dermatitis in HCWs in our hospital by means of a survey which also examined trends of exposure and the utility of patch testing.

METHODS

HCWs diagnosed with hand dermatitis in our contact dermatitis clinic from January 2011 to July 2012 were included. Information was collected retrospectively from medical notes, computer records and the database of the British Cutaneous Allergy Society.

RESULTS

A total of 69 HCWs were diagnosed with hand dermatitis, with a prevalence of ~4%. The majority were female and the clinical areas in which they worked were diverse. About 98% (68) had irritant contact dermatitis, and hand washing was the commonest cause of symptoms. About 75% (51) had irritant dermatitis exclusively. Patch test was positive in 42% with the commonest reaction to nickel, followed by formaldehyde. Associated atopy was found in less than half of the cases.

CONCLUSIONS

Irritant hand dermatitis is prevalent in HCWs in this setting. Patch testing is useful to identify any additional allergic element in such cases.

Activation of human brown adipose tissue by a β3-adrenergic receptor agonist

Increasing energy expenditure through activation of endogenous brown adipose tissue (BAT) is a potential approach to treat obesity and diabetes. The class of β3-adrenergic receptor (AR) agonists stimulates rodent BAT, but this activity has never been demonstrated in humans. Here we determined the ability of 200 mg oral mirabegron (Myrbetriq, Astellas Pharma, Inc.), a β3-AR agonist currently approved to treat overactive bladder, to stimulate BAT as compared to placebo. Mirabegron led to higher BAT metabolic activity as measured via (18)F-fluorodeoxyglucose ((18)F-FDG) using positron emission tomography (PET) combined with computed tomography (CT) in all twelve healthy male subjects (p = 0.001), and it increased resting metabolic rate (RMR) by 203 ± 40 kcal/day (+13%; p = 0.001). BAT metabolic activity was also a significant predictor of the changes in RMR (p = 0.006). Therefore, a β3-AR agonist can stimulate human BAT thermogenesis and may be a promising treatment for metabolic disease.

Revascularization grading in endovascular acute ischemic stroke therapy

BACKGROUND

Recanalization and angiographic reperfusion are key elements to successful endovascular and interventional acute ischemic stroke (AIS) therapy. Intravenous recombinant tissue plasminogen activator (rt-PA), the only established revascularization therapy approved by the US Food & Drug Administration for AIS, may be less effective for large artery occlusion. Thus, there is enthusiasm for endovascular revascularization therapies, which likely provide higher recanalization rates, and trials are ongoing to determine clinical efficacy and compare various methods. It is anticipated that clinical efficacy will be well correlated with revascularization of viable tissue in a timely manner.

METHOD

Reporting, interpretation, and comparison of the various revascularization grading methods require agreement on measurement criteria, reproducibility, ease of use, and correlation with clinical outcome. These parameters were reviewed by performing a Medline literature search from 1965 to 2011. This review critically evaluates current revascularization grading systems.

RESULTS AND CONCLUSION

The most commonly used revascularization grading methods in AIS interventional therapy trials are the thrombolysis in cerebral ischemia (TICI, pronounced "tissy") and thrombolysis in myocardial ischemia (TIMI) scores. Until further technical and imaging advances can incorporate real-time reliable perfusion studies in the angio-suite to delineate regional perfusion more accurately, the TICI grading system is the best defined and most widely used scheme. Other grading systems may be used for research and correlation purposes. A new scale that combines primary site occlusion, lesion location, and perfusion should be explored in the future.

Blow fly Lucilia sericata nuclease digests DNA associated with wound slough/eschar and with Pseudomonas aeruginosa biofilm

In chronic wounds, it may be clinically important to remove extracellular bacterial and patient DNA as its presence may impede wound healing and promote bacterial survival in biofilm, in which extracellular DNA forms part of the biofilm architecture. As medicinal maggots, larvae of Lucilia sericata Meigen (Diptera: Calliphoridae) have been shown to efficiently debride wounds it became of interest to investigate their excretions/secretions (ES) for the presence of a deoxyribonuclease (DNAse) activity. Excretions/secretions products were shown to contain a DNAse, with magnesium, sodium and calcium metal ion dependency, and a native molecular mass following affinity purification of approximately 45 kDa. The affinity purified DNAse degraded genomic bacterial DNA per se, DNA from the slough/eschar of a venous leg ulcer, and extracellular bacterial DNA in biofilms pre-formed from a clinical isolate of Pseudomonas aeruginosa. The latter finding highlights an important attribute of the DNAse, given the frequency of P. aeruginosa infection in non-healing wounds and the fact that P. aeruginosa virulence factors can be toxic to maggots. Maggot DNAse is thus a competent enzyme derived from a rational source, with the potential to assist in clinical wound debridement by removing extracellular DNA from tissue and biofilm, and promoting tissue viability, while liberating proteinaceous slough/eschar for debridement by the suite of proteinases secreted by L. sericata.

SU-E-I-06: Measurement of Skin Dose from Dental Cone-Beam CT Scans

PURPOSE

To directly measure skin dose using point-dosimeters from dental cone-beam CT (CBCT) scans. To compare the results among three different dental CBCT scanners and compare the CBCT results with those from a conventional panoramic and cephalomic dental imaging system.

METHODS

A head anthropomorphic phantom was used with nanoDOT dosimeters attached to specified anatomic landmarks of selected radiosensitive tissues of interest. To ensure reliable measurement results, three dosimeters were used for each location. The phantom was scanned under various modes of operation and scan protocols for typical dental exams on three dental CBCT systems plus a conventional dental imaging system. The Landauer OSL nanoDOT dosimeters were calibrated under the same imaging condition as the head phantom scan protocols, and specifically for each of the imaging systems. Using nanoDOT dosimeters, skin doses at several positions on the surface of an adult head anthropomorphic phantom were measured for clinical dental imaging.

RESULTS

The measured skin doses ranged from 0.04 to 4.62mGy depending on dosimeter positions and imaging systems. The highest dose location was at the parotid surface for all three CBCT scanners. The surface doses to the locations of the eyes were ∼4.0mGy, well below the 500mGy threshold for possibly causing cataract development. The results depend on x-ray tube output (kVp and mAs) and also are sensitive to SFOV. Comparing to the conventional dental imaging system operated in panoramic and cephalometric modes, doses from all three CBCT systems were at least an order of magnitude higher. No image artifact was caused by presence of nanoDOT dosimeters in the head phantom images.

CONCLUSIONS

Direct measurements of skin dose using nanoDOT dosimeters provided accurate skin dose values without any image artifacts. The results of skin dose measurements serve as dose references in guiding future dose optimization efforts in dental CBCT imaging.

Allergic contact dermatitis: epidemiology, molecular mechanisms, in vitro methods and regulatory aspects. Current knowledge assembled at an international workshop at BfR, Germany

Contact allergies are complex diseases, and one of the important challenges for public health and immunology. The German ‘Federal Institute for Risk Assessment’ hosted an ‘International Workshop on Contact Dermatitis’. The scope of the workshop was to discuss new discoveries and developments in the field of contact dermatitis. This included the epidemiology and molecular biology of contact allergy, as well as the development of new in vitro methods. Furthermore, it considered regulatory aspects aiming to reduce exposure to contact sensitisers. An estimated 15–20% of the general population suffers from contact allergy. Workplace exposure, age, sex, use of consumer products and genetic predispositions were identified as the most important risk factors. Research highlights included: advances in understanding of immune responses to contact sensitisers, the importance of autoxidation or enzyme-mediated oxidation for the activation of chemicals, the mechanisms through which hapten-protein conjugates are formed and the development of novel in vitro strategies for the identification of skin-sensitising chemicals. Dendritic cell cultures and structure-activity relationships are being developed to identify potential contact allergens. However, the local lymph node assay (LLNA) presently remains the validated method of choice for hazard identification and characterisation. At the workshop the use of the LLNA for regulatory purposes and for quantitative risk assessment was also discussed.

The role of PET and PET/CT in managing the care of lymphoma patients

The clinical use of PET and PET/CT aids physicians and patients in developing lymphoma prognoses, specifically for Hodgkin disease and aggressive types of non-Hodgkin lymphoma. PET and PET/CT are used to initially stage lymphoma, restage disease, and check for remission or recurrence of malignant tissue after treatment. PET/CT is more sensitive and specific than CT alone and has better accuracy concerning lymphoma relapse and remission. In conjunction with other tests, such as blood laboratory work and biopsy, PET and PET/CT allow the lymphoma to be staged appropriately and treated correctly. Results from PET and PET/CT contribute to the formation of a specialized treatment plan that leads to the best possible care for each individual patient. PET and PET/CT positively affect the management of patients with lymphoma.