Near infrared laser-tissue welding using nanoshells as an exogenous absorber

BACKGROUND AND OBJECTIVE: Gold nanoshells are a new class of nanoparticles that can be designed to strongly absorb light in the near infrared (NIR). These particles provide much larger absorption cross-sections and efficiency than can be achieved with currently used chemical chromophores without photobleaching. In these studies, we have investigated the use of gold nanoshells as exogenous NIR absorbers to facilitate NIR laser-tissue welding. STUDY DESIGN/MATERIALS AND METHODS: Gold nanoshells with peak extinction matching the NIR wavelength of the laser being used were manufactured and suspended in an albumin solder. Optimization work was performed on ex vivo muscle samples and then translated into testing in an in vivo rat skin wound-healing model. Mechanical testing of the muscle samples was immediately performed and compared to intact tissue mechanical properties. In the in vivo study, full thickness incisions in the dorsal skin of rats were welded, and samples of skin were excised at 0, 5, 10, 21, and 32 days for analysis of strength and wound healing response. RESULTS: Mechanical testing of nanoshell-solder welds in muscle revealed successful fusion of tissues with tensile strengths of the weld site equal to the uncut tissue. No welding was accomplished with this light source when using solder formulations without nanoshells. Mechanical testing of the skin wounds showed sufficient strength for closure and strength increased over time. Histological examination showed good wound-healing response in the soldered skin. CONCLUSIONS: The use of nanoshells as an exogenous absorber allows the usage of light sources that are minimally absorbed by tissue components, thereby, minimizing damage to surrounding tissue and allowing welding of thicker tissues.     

Effectivity of laser-induced thermotherapy: in vivo comparison of arterial microembolization and complete hepatic inflow occlusion

BACKGROUND AND OBJECTIVES: Laser-induced thermotherapy (LITT) is a promising method for local treatment of liver metastases. The aim of this study was to compare the effect of LITT on lesion size when combined with hepatic arterial microembolization or complete hepatic blood flow occlusion. STUDY DESIGN/MATERIALS AND METHODS: In a porcine liver model, LITT (30 W 15 minutes) was performed with either normal (n = 12), partially interrupted (arterial microembolization via a hepatic artery catheter n = 12) or completely interrupted hepatic perfusion (Pringle's maneuver, n = 12). LITT lesions were macro- and microscopically assessed after liver dissection. RESULTS: Hepatic inflow occlusion led to a fourfold increase in lesion volume after arterial microembolization and a ninefold increase after complete interruption (6.3. cm3 vs. 27.1 cm3 vs. 58.8 cm3, P < 0.01). CONCLUSIONS: Interrupting hepatic perfusion significantly increases lesion volumes in LITT. This beneficial effect can also be achieved in the percutaneous application mode by LITT combined with arterial microembolization via a hepatic artery catheter.     

The Biomedical Research Hub: a federated platform for patient research data

ObjectiveThe objective was to develop and operate a cloud-based federated system for managing, analyzing, and sharing patient data for research purposes, while allowing each resource sharing patient data to operate their component based upon their own governance rules. The federated system is called the Biomedical Research Hub (BRH).Materials and MethodsThe BRH is a cloud-based federated system built over a core set of software services called framework services. BRH framework services include authentication and authorization, services for generating and assessing findable, accessible, interoperable, and reusable (FAIR) data, and services for importing and exporting bulk clinical data. The BRH includes data resources providing data operated by different entities and workspaces that can access and analyze data from one or more of the data resources in the BRH.ResultsThe BRH contains multiple data commons that in aggregate provide access to over 6 PB of research data from over 400 000 research participants.Discussion and conclusionWith the growing acceptance of using public cloud computing platforms for biomedical research, and the growing use of opaque persistent digital identifiers for datasets, data objects, and other entities, there is now a foundation for systems that federate data from multiple independently operated data resources that expose FAIR application programming interfaces, each using a separate data model. Applications can be built that access data from one or more of the data resources.     

Consensus on melanonychia nail plate dermoscopy

This statement, focused on melanonychia and nail plate dermoscopy, is intended to guide medical professionals working with melanonychia and to assist choosing appropriate management for melanonychia patients. The International Study Group on Melanonychia was founded in 2007 and currently has 30 members, including nail experts and dermatopathologists with special expertise in nails. The need for common definitions of nail plate dermoscopy was addressed during the Second Meeting of this Group held in February 2008. Prior to this meeting and to date (2010) there have been no evidence-based guidelines on the use of dermoscopy in the management of nail pigmentation.     

Relationship between the width of the zone of keratinized tissue and thickness of gingival tissue in the anterior maxilla

The aim of this study was to evaluate whether there is a positive correlation between the width of the zone of gingival keratinized tissue and its thickness. Maxillary right canines, lateral incisors, and central incisors of 60 patients (30 men, 30 women) between the ages of 20 and 35 years were examined. Using an endodontic spacer with a rubber cursor and a digital caliper of 0.01-mm resolution, the values of the width of the zone of gingival keratinized tissue and gingival thickness were obtained. It was observed that the lateral incisor has the largest mean zone of gingival keratinized tissue (5.54 ± 1.09 mm), followed by the central incisor (4.62 ± 1.02 mm) and canine (4.32 ± 1.33 mm). The mean gingival thickness was greater in the central incisor (1.17 ± 0.20 mm), followed by the lateral incisor (1.04 ± 0.24 mm) and canine (0.87 ± 0.27 mm). No statistically significant difference was verified for the mean width of the zone of gingival keratinized tissue and gingival thickness between men and women. A positive correlation between gingival thickness and width of the zone of gingival keratinized tissue was observed in the maxillary canine (Pearson r = 0.398, P < .05), lateral incisor (Pearson r = 0.369, P < .05), and central incisor (Pearson r = 0.492, P < .05). In patients 20 to 35 years of age, there was a positive correlation between gingival thickness and width of the zone of gingival keratinized tissue for the maxillary right canine, lateral incisor, and central incisor.     

Eccentric fixation in Stargardt's disease assessed by Tübingen perimetry

PURPOSE: To measure eccentric fixation characteristics in visual fields of patients with Stargardt's disease. METHODS: The positions of fixation loci (FL) in the visual field were determined by Tübingen perimetry (TP), using the position of the blind spots in 173 patients. Altogether, 669 visual fields were measured at baseline and during follow-up. Twenty patients were also examined by scanning laser ophthalmoscope (SLO). RESULTS: Ninety-five of 173 patients showed a ring scotoma with central fixation in at least one test, which could persist for up to 18.8 years. The median age for a 50% chance of the development of eccentric fixation was 23.6 years. One hundred four patients (203 eyes) used eccentric fixation in at least one eye; in 154 eyes, the FL was placed below the scotoma and in 33 eyes to the left of it, in 11 to the right of it, and in 5 above it. Once the FL was chosen, it remained within the same visual field area at subsequent tests, varying on average by 1.76 degrees. Compared with SLO results, the mean distance between FL and PRL was 1.90 degrees. CONCLUSIONS: It is possible to determine the position of the FL by perimetry with sufficient accuracy if the blind spot is well delimited. Stargardt patients can keep central fixation for different time intervals before changing to an eccentric FL. Most of them show an FL below the central scotoma, which is considered favorable for horizontal reading.     

Microstructural abnormalities in MEWDS demonstrated by ultrahigh resolution optical coherence tomography

BACKGROUND: Histopathological studies of acute multiple evanescent white dot syndrome (MEWDS) have not been reported because of the transient and benign nature of the disease. Ultrahigh resolution optical coherence tomography (UHR-OCT), capable of high resolution in vivo imaging, offers a unique opportunity to visualize retinal microstructure in the disease. METHODS: UHR-OCT images of the maculae of five patients with MEWDS were obtained and analyzed. Diagnosis was based on clinical presentation, examination, visual field testing, and angiography. RESULTS: UHR-OCT revealed disturbances in the photoreceptor inner/outer segment junction (IS/OS) in each of the five patients (six eyes) with MEWDS. In addition, thinning of the outer nuclear layer was seen in the case of recurrent MEWDS, suggesting that repeated episodes of MEWDS may result in photoreceptor atrophy. CONCLUSIONS: Subtle disruptions of the photoreceptor IS/OS are demonstrated in all eyes affected by MEWDS. UHR-OCT may be a useful adjunct to diagnosis and monitoring of MEWDS.     

Pimecrolimus identifies a common genomic anti-inflammatory profile,is clinically highly effective in psoriasis and is well tolerated

The ascomycin macrolactam pimecrolimus is a novel inflammatory cytokine release inhibitor that so far has not been administered systemically to humans. In this phase I/II randomized double-blind, placebo-controlled, multiple rising dose proof of concept study psoriasis patients were treated with oral pimecrolimus or placebo. Gene profiling identified a common genomic profile with a downregulation of genes associated with inflammation but no changes in gene expression linked to drug-related side-effects. A steady state of pimecrolimus was reached after 5-10 d, Cmax, and area under the curve (0-24) was 54.5 ng per ml and 589.9 ng h per ml, respectively, at steady state at the highest dose. There was clear clinical efficacy in patients receiving 20 mg pimecrolimus twice daily and 30 mg twice daily with a reduction of Psoriasis Area and Severity Index by 60% and 75%, respectively. Histopatho logically and immunopathologically there was a reversion of the psoriatic phenotype towards normal. There were no notable clinical, laboratory, kidney function, or immunologic side-effects. We conclude that pimecrolimus taken orally is highly effective in a concentration-dependent manner in patients with psoriasis and on a short-term basis it is well tolerated and this is confirmed by its pharmacogenomic profile. The latter also indicates that pimecrolimus should be equally effective in other inflammatory skin diseases.     

A technical concept of a computer game for patients with Parkinson's disease – a new form of PC-based physiotherapy

Background: At present, there are no meaningful and sophisticated computer games that simultaneously allow the treatment of movement disorders such as Parkinson's syndrome. In particular, there are no systems to consider the severity of the disease and the physical skills of the patient.

Methods: A computer game using the Microsoft Kinect as markerless sensor for the 3?D recognition of the patient’s movement was developed to support the rehabilitation. The scenario of a basketball game was created after determining that the movement like throwing a ball and the correct posture of the body are important. A study based on system usability was performed with 15 patients to evaluate the system.

Results: The technical feasibility of a computer-assisted training system for supporting patients with Parkinson‘s disease has been demonstrated. No markers on the patient are required for movement detection and allow a user-friendly handling. Regarding the usability study, the patients were accepting of such a system and its at-home use and symptoms like ‘freezing’ and the Pisa syndrome can be treated.

Conclusions: The physiotherapist can be assisted by the developed rehabilitation system. An objective measurement of the patient’s training progress delivers valuable information to adjust the training sessions for every patient individually. Due to its modular character, the system can also be applied to other diseases or sports injuries and offers the basis for further development.