Low-Frequency Sonophoresis: Ultrastructural Basis for Stratum Corneum Permeability Assessed Using Quantum Dots

Low-frequency sonophoresis (LFS) has been well documented to enhance the permeability of skin to macromolecular drugs via induction of localized transport regions. However, the organizational details of epidermis, specifically stratum corneum (SC), during sonophoresis are beyond the resolution limit of common histo-optical microscopy tools, which fail to reveal any notable structural alterations in these regions at a submicroscopic scale. Here we report, using quantum dots (QDs) as a tracer and confocal microscopy and transmission electron microscopy (TEM) (with OsO4 and RuO4 post-fixation) as visualization methods, on LFS-induced permeation pathways in the SC. QDs (20nm diameter) penetrated well beyond the SC. TEM revealed that ultrasound significantly increased the frequency of occurrence of the otherwise scattered and separated lacunar spaces in the SC. A significant increase in lacunar dimensions was observed when 1% w/v sodium lauryl sulfate was added to the coupling medium. These studies show that LFS induces dilatation and higher connectivity of voids in the SC, possibly leading to formation of a three-dimensional porous network, which is capable of transporting QDs as well as macromolecules across the SC. This contention is consistent with previously conceived theoretical mechanistic understanding of LFS-induced enhanced transport across the skin

Identification of a functional enhancer variant within the chronic pancreatitis-associated SPINK1 c.101A>G (p.Asn34Ser)-containing haplotype

The haplotype harboring the SPINK1 c.101A>G (p.Asn34Ser) variant (also known as rs17107315:T>C) represents the most important heritable risk factor for idiopathic chronic pancreatitis identified to date. The causal variant contained within this risk haplotype has however remained stubbornly elusive. Herein, we set out to resolve this enigma by employing a hypothesis-driven approach. First, we searched for variants in strong linkage disequilibrium (LD) with rs17107315:T>C using HaploReg v4.1. Second, we identified two candidate SNPs by visual inspection of sequences spanning all 25 SNPs found to be in LD with rs17107315:T>C, guided by prior knowledge of pancreas-specific transcription factors and their cognate binding sites. Third, employing a novel cis-regulatory module (CRM)-guided approach to further filter the two candidate SNPs yielded a solitary candidate causal variant. Finally, combining data from phylogenetic conservation and chromatin accessibility, cotransfection transactivation experiments, and population genetic studies, we suggest that rs142703147:C>A, which disrupts a PTF1L-binding site within an evolutionarily conserved HNF1A−PTF1L CRM located ∼4 kb upstream of the SPINK1 promoter, contributes to the aforementioned chronic pancreatitis risk haplotype. Further studies are required not only to improve the characterization of this functional SNP but also to identify other functional components that might contribute to this high-risk haplotype

Ultrasound-Enhanced Drug Transport and Distribution in the Brain

Drug delivery in the brain is limited by slow drug diffusion in the brain tissue. This study tested the hypothesis that ultrasound can safely enhance the permeation of drugs in the brain. In vitro exposure to ultrasound at various frequencies (85 kHz, 174 kHz, and 1 MHz) enhanced the permeation of tritium-labeled molecules with molecular weight up to 70 kDa across porcine brain tissue. A maximum enhancement of 24-fold was observed at 85 kHz and 1,200 J/cm2. In vivo exposure to 1-MHz ultrasound further demonstrated the ability of ultrasound to facilitate molecule distribution in the brain of a non-human primate. Finally, ultrasound under conditions similar to those used in vivo was shown to cause no damage to plasmid DNA, siRNA, adeno-associated virus, and fetal rat cortical neurons over a range of conditions. Altogether, these studies demonstrate that ultrasound can increase drug permeation in the brain in vitro and in vivo under conditions that did not cause detectable damage

Rapid Sampling of Molecules via Skin for Diagnostic and Forensic Applications

Skin provides an excellent portal for diagnostic monitoring of a variety of entities; however, there is a dearth of reliable methods for patient-friendly sampling of skin constituents. This study describes the use of low-frequency ultrasound as a one-step methodology for rapid sampling of molecules from the skin. Sampling was performed using a brief exposure of 20 kHz ultrasound to skin in the presence of a sampling fluid. In vitro sampling from porcine skin was performed to assess the effectiveness of the method and its ability to sample drugs and endogenous epidermal biomolecules from the skin. Dermal presence of an antifungal drug—fluconazole and an abused substance, cocaine—was assessed in rats. Ultrasonic sampling captured the native profile of various naturally occurring moisturizing factors in skin. A high sampling efficiency (79 ± 13%) of topically delivered drug was achieved. Ultrasound consistently sampled greater amounts of drug from the skin compared to tape stripping. Ultrasonic sampling also detected sustained presence of cocaine in rat skin for up to 7 days as compared to its rapid disappearance from the urine. Ultrasonic sampling provides significant advantages including enhanced sampling from deeper layers of skin and high temporal sampling sensitivity

No association between CEL-HYB hybrid allele and chronic pancreatitis in Asian populations

International audienceA hybrid allele between the carboxyl ester lipase gene (CEL) and its pseudogene, CELP (called CEL–HYB), generated by non-allelic homologous recombination between CEL intron 10 and CELP intron 10′, was found to increase susceptibility to chronic pancreatitis in a case–control study of patients of European ancestry. We attempted to replicate this finding in 3 independent cohorts from China, Japan, and India, but failed to detect the CEL–HYB allele in any of these populations. The CEL–HYB allele might therefore be an ethnic-specific risk factor for chronic pancreatitis. An alternative hybrid allele (CEL–HYB2) was identified in all 3 Asian populations (1.7% combined carrier frequency), but was not associated with chronic pancreatitis

Rapid Sampling of Molecules via Skin for Diagnostic and Forensic Applications

Skin provides an excellent portal for diagnostic monitoring of a variety of entities; however, there is a dearth of reliable methods for patient-friendly sampling of skin constituents. This study describes the use of low-frequency ultrasound as a one-step methodology for rapid sampling of molecules from the skin. Sampling was performed using a brief exposure of 20 kHz ultrasound to skin in the presence of a sampling fluid. In vitro sampling from porcine skin was performed to assess the effectiveness of the method and its ability to sample drugs and endogenous epidermal biomolecules from the skin. Dermal presence of an antifungal drug—fluconazole and an abused substance, cocaine—was assessed in rats. Ultrasonic sampling captured the native profile of various naturally occurring moisturizing factors in skin. A high sampling efficiency (79 ± 13%) of topically delivered drug was achieved. Ultrasound consistently sampled greater amounts of drug from the skin compared to tape stripping. Ultrasonic sampling also detected sustained presence of cocaine in rat skin for up to 7 days as compared to its rapid disappearance from the urine. Ultrasonic sampling provides significant advantages including enhanced sampling from deeper layers of skin and high temporal sampling sensitivity

Orbital floor dermoid: An unusual presentation

Dermoid cysts are developmental abnormal arrangement of tissues and are often evident soon after birth. Its occurrence in the orbit is relatively rare. We report a case of orbital floor dermoid in an 18-year-old female patient who presented with progressive, painless swelling in the lower eyelid associated with mild proptosis of three months duration. The lesion was excised completely, and histopathology confirmed the diagnosis of dermoid cyst

Orbital floor dermoid: An unusual presentation

Dermoid cysts are developmental abnormal arrangement of tissues and are often evident soon after birth. Its occurrence in the orbit is relatively rare. We report a case of orbital floor dermoid in an 18-year-old female patient who presented with progressive, painless swelling in the lower eyelid associated with mild proptosis of three months duration. The lesion was excised completely, and histopathology confirmed the diagnosis of dermoid cyst