The dark side of testosterone deficiency: I. Metabolic syndrome and erectile dysfunction

The metabolic syndrome (MetS) is considered the most important public health threat of the 21st century. This syndrome is characterized by a cluster of cardiovascular risk factors including increased central abdominal obesity, elevated triglycerides, reduced high-density lipoprotein, high blood pressure, increased fasting glucose, and hyperinsulinemia. These factors increase the risk of cardiovascular disease (CVD) and/or type 2 diabetes. Although the etiology of this syndrome is thought to stem from obesity and physical inactivity, the extent of interactions of the individual MetS components with one another remains poorly defined. Obesity, diabetes, hypogonadism, and specific hormone and metabolic profiles have been implicated in the pathophysiology of CVD. The evolving role of androgens in MetS and CVD is of paramount importance. Reduced androgen levels associated with hypogonadism or androgen deprivation therapy increase cardiovascular risk factors and produce marked adverse effects on cardiovascular function. MetS has been associated with hypogonadism and erectile dysfunction (ED), and MetS may be considered a risk factor for ED. It is suggested that MetS, diabetes, and CVD will increase in the upcoming decades. Thus, it is critically important to develop a better understanding of how obesity, diabetes and hypogonadism contribute to androgen deficiency and the various pathophysiologic states of vascular disease. In this review we discuss the current literature pertaining to androgen deficiency, MetS, and ED, because the relationship of these factors is of scientific and clinical importance. Specifically, we will focus on exploring the relationships between hypogonadism, obesity, MetS, and ED.     

Pure ‘natural orifice transluminal endoscopic surgery’ for transvaginal nephrectomy in the porcine model

OBJECTIVES

To determine the technical feasibility and reproducibility of pure natural orifice transluminal endoscopic surgery (NOTES) transvaginal nephrectomy using NOTES‐specific instrumentation, with no transabdominal assistance.

MATERIALS AND METHODS

Five female farm pigs (mean weight 45 kg) had a right NOTES nephrectomy, using a single‐channel gastroscope in the first three pigs and a dual‐channel gastroscope in the remaining two. The peritoneal cavity was accessed through the posterior fornix of the vagina. Dissection was started at the lower pole of the kidney, and the ureter was retracted laterally and followed towards the hilum. An XL articulated 60 cm endo‐GIA stapler (US Surgical, Norwalk, CO, USA), inserted transvaginally via a separate vaginal incision, was used for tissue retraction and renal hilar transection. The kidney was freed, entrapped in an impermeable sac, and extracted intact transvaginally.

RESULTS

All five procedures were successful with no addition of a transabdominal laparoscopic port or open conversion. The total operative duration decreased from 200 min in the first pig to 60 min in the last (mean 113 min); the mean blood loss was <50 mL, the mean kidney length was 13.9 cm and the weight was 142 g. There were no intraoperative complications; at autopsy, there was no pelvic or bowel injury.

CONCLUSIONS

Pure NOTES transvaginal nephrectomy is feasible in the porcine model. It has the potential of a less morbid approach, providing truly scar‐less surgery. Further development of instrumentation is necessary.     

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.