Oxidative stress-independent depletion of epidermal vitamin A by UVA

In hairless mice, epidermal vitamin A (retinol and retinyl esters) is strongly decreased following a single exposure to UVB. Here, using the same mouse model, we studied the effects of UVA on epidermal vitamin A content, lipid peroxidation, and CRBP-I expression, as well as the putative prevention of vitamin A depletion or lipid peroxidation by topical alpha-tocopherol. An acute exposure to UVA completely depleted epidermal vitamin A with EC50 of 0.25 and 0.5 J per cm2 for retinyl esters and retinol, respectively; these values were 0.1 J per cm2 for both retinoids under UVB exposure. CRBP-I expression was increased 2-fold 8 h following UVA exposure (10 J per cm2), and this increase persisted for at least 16 h. A single UVA exposure induced a concentration-dependent epidermal lipid peroxidation (EC50 = 3.5 J per cm2) giving rise to 55.4 +/- 4.2 nmol lipid peroxides per g at 20 J per cm2, whereas UVB, up to 1 J per cm2, did not increase the basal concentration of 6.7 +/- 0.9 nmol lipid peroxides per g. On the other hand, topical menadione induced a concentration-dependent lipid peroxidation, but did not affect vitamin A content. Pretreatment with alpha-tocopherol (i) did not inhibit UV-induced vitamin A depletion, (ii) completely inhibited the increased lipid peroxidation induced by UVA or menadione, and (iii) accelerated reconstitution of epidermal vitamin A after UVB but not UVA induced depletion. Thus acute UVA induced both epidermal vitamin A depletion and lipid peroxidation, UVB induced only vitamin A depletion, and menadione induced only a lipid peroxidation; topical alpha-tocopherol prevented lipid peroxidation but not vitamin A depletion. These observations indicate (i) that CRBP-I neither provides protection to UVB- and UVA-induced epidermal vitamin A depletion, nor interferes significantly with reconstitution, and (ii) that the UV-induced vitamin A depletion and lipid peroxidation in mouse epidermis are unrelated processes. UV light does not destroy epidermal vitamin A through an oxidative stress but probably by a photochemical reaction in which UV radiations at about 325 nm give the corresponding activation energy.     

An infiltrative variant of non-neural granular cell tumor: a case report

Dermal non-neural granular cell tumors are rare tumors of indeterminate lineage that typically present as well-circumscribed tumors with nuclear pleomorphism and mitotic activity. We describe a dermal non-neural granular cell tumor with a distinctive growth pattern with granular cells interspersed between collagen bundles. This asymptomatic papule arose on the scapula of a 46-year-old woman and consisted of a mixture of epithelioid and spindled granular cells. The immunohistochemical characteristics were similar to those of previously reported dermal non-neural granular cell tumors. Despite mild nuclear pleomorphism and dispersion of lesional cells among collagen bundles, mitoses were not present and Ki-67 staining indicated a low proliferative rate. In addition to being S-100 protein negative and NKI/C3 positive, our case was positive for PGP9.5 and weakly positive for neuron-specific enolase, a staining pattern similar to what has been observed for cellular neurothekeomas. Our case could represent a dermal non-neural granular cell tumor with unique architecture, a granular cellular neurothekeoma or a granular cell dermatofibroma. As both dermal non-neural granular cell tumor and cellular neurothekeoma are of indeterminate lineage, our case with features characteristic of both entities may suggest a common precursor or lineage for dermal non-neural granular cell tumor and cellular neurothekeoma.     

An unusual interatrial septum

The images focus on a very rare atrial septal anatomy known as "double atrial septum with persistent interatrial space.” Only scarce reports of this anomaly are found in literature. Due to increasing use of catheter-based interventions requiring a transseptal puncture, the recognition of this anomaly is essential for performing safe and effective procedures.     

Inner choroidal ischaemia and CNV due to handheld laser-induced maculopathy: a case report and review

There has been a sharp rise of reported handheld laser-induced maculopathy (HLIM) cases over the past decade, a concerning trend that may continue due to unregulated online access to high power lasers. Though HLIM has distinct clinical features, not uncommonly it may masquerade as other retinal disorders. It is critical therefore to recognise the clinical and multimodal imaging characteristics of this important and potentially devastating condition. As HLIM patients are typically young, unique issues need to be considered, such as delayed presentation, difficult history, poor compliance and behavioural or psychiatric comorbidity. This article will review the clinical and diagnostic features of laser injury, with a special emphasis on the multimodal retinal findings. In addition, we present a unique case of HLIM, resembling the presentation of a placoid disease variant and illustrating choroidal ischaemia using advanced retinal imaging, that offers further insight into the mechanisms of laser injury and its complications. The issues addressed in this review aim to increase recognition of an increasingly important and trending condition with potentially profound visual complications.Subject terms: Retinal diseases, Paediatrics, Trauma     

Treatment of hepatitis C

Hepatitis C virus infection accounts for 40% of chronic liver disease in the United States and is the most common indication for liver transplantation. Estimates suggest that 4 million people, or 1.8% of the American population, have or have had hepatitis C virus infection. Pegylated interferon and ribavirin are the current standard of care for treatment. Recent studies have suggested that ribavirin dose and duration of therapy may be adjusted based on genotype. The goals of therapy are to slow disease progression, improve hepatic histology, reduce infectivity, and decrease the risk of hepatocellular carcinoma. Sustained virologic response, which generally implies the absence of viremia 6 or more months following completion of therapy, is increasingly being regarded as a cure, with evidence of slowing or even regression of fibrosis on follow-up liver biopsy. Assessment by liver biopsy of disease severity and evaluation of comorbidities and possible contraindications to therapy should be weighed in the decision to begin treatment. Counseling patients regarding transmission, natural history, and drug and alcohol abstinence should also be included in management. Close monitoring should be done during treatment for interferon and ribavirin side effects, including depression, bone marrow suppression, and hemolytic anemia.     

Lung inflation with direct injection of agarose: a technique for simultaneous molecular and morphometric measurements

The usual methods for preparing lungs for morphologic study involve the instillation of fixatives that modifyproteins and RNA such that the tissue is unsuitable for molecular studies. To develop a technique suitable for molecular studies, pieces of adult rat lungs were infiltrated with agarose, glutaraldehyde, or paraformaldehyde and the consistency of alveolar inflation was compared to lungs inflated with 10% formalin. Only direct injection with 1% agarose resulted in comparable inflation of lung tissue and preserved RNA and protein. Thus, this technique enables simultaneous molecular and morphometric analysis of the lung on small pieces of lung tissue in heterogeneous lung diseases.     

Understanding the tribological impacts of alkali element on lubrication of binary borate melt

Melt lubricants have been regarded as an effective class to deliver lubrication on moving mechanical contacts at extreme temperatures. Among the elementary constituents, alkali elements play a critical role in governing the physical–chemical characteristics of the lubricant despite the obscurity regarding their intrinsic roles on the rubbing interfaces. The present study attempts to unfold the effects of sodium on the tribological responses of mating steel pair under borate melt lubrication. It has been found that the involvement of Na inspires a total reversal in lubricating potentials of the lone B₂O₃ melt manifested by remarkable friction reduction, wear inhibition and prolonged load-bearing capacity. These exceptional performances are attributed to the accretion of nanothin Na layers on the contact interfaces. The interfacial occurrences are interpreted from a physico-chemistry perspective while the influences of surface microstructure are also discussed in detail. Multiple characterizations are employed to thoroughly examine the sliding interfaces in multi-dimensions including Scanning Electron Microscopy (SEM), Scanning Transmission Electron Microscopy (STEM) and Atomic Force Microscopy (AFM). In addition, chemical fingerprints of relevant elements are determined by Energy Dispersive Spectroscopy (EDS) and Electron Loss Energy Spectroscopy (EELS).

The involvement of sodium induces dramatic transformation in lubrication potentials of boron oxide melt.     

Beneficial long-term effects of hydralazine in aortic regurgitation

The long-term effects of vasodilators in asymptomatic patients with aortic regurgitation have not been studied extensively. We retrospectively reviewed the echocardiograms of 19 asymptomatic patients with significant aortic regurgitation followed up annually for up to 4 years (average +/- SD, 3.1 +/- 0.7 years). Of these 19 patients, 12 were not receiving vasodilators and 7 were receiving hydralazine hydrochloride, 40 to 200 mg daily. In the patients not receiving vasodilators, left ventricular diastolic and systolic dimensions increased progressively in all patients by an average of 8% and 13%, respectively, after 3 years. In the patients receiving hydralazine, left ventricular dimensions increased by 9% and 5% in the year or more before hydralazine use and decreased by 7% and 7%, respectively, during the first year after using hydralazine. The reduction was observed in all patients during the first year, but an increase was detected in 3 patients followed up beyond that period. The results suggest that the progression of left ventricular dilatation in asymptomatic patients with aortic regurgitation can be delayed by long-term therapy with vasodilators. Pending further confirmation, such therapy may possibly influence the natural history of the disease and delay the timing of operation.     

Enhanced ferromagnetism of ZnO@Co/Ni hybrid core@shell nanowires grown by electrochemical deposition method

The hybrid structure of ZnO NWs with the presence of different dopants recently has drawn many interests from researchers due to the possibility to integrate multiple functionalities into one single structure. In this article, we investigated the morphology, crystal structure and ferromagnetism of the ZnO@Co/Ni hybrid core@shell NWs prepared by a facile electrochemical deposition method. The results show that a thin layer of Ni and Co coated on the surface of ZnO NWs (confirmed by XRD, EDS, TEM and Raman scattering) can create a significant improvement of ferromagnetic property in such hybrid core@shell NWs. In which, for the coating time of 10, 15, 20 min, the value of M_s is around 0.67, 0.88 and 2.56 emu g⁻¹ for ZnO@Co NWs, and about 0.013, 0.022 and 0.031 emu g⁻¹ for ZnO@Ni NWs, respectively, in comparison with the number of 0.016 emu g⁻¹ for pure ZnO NWs. Interestingly, we also found the temperature dependence of ferromagnetism of such Co/Ni coated ZnO NWs. These results reveal the possibility to employ such hybrid core@shell NWs for many applications, e.g. spin field effect transistors.

Facile electrochemical synthesis of ZnO@Co and ZnO@Ni hybrid core@shell nanowires with enhanced ferromagnetism.