Smart Sensor-Based Motion Detection System for Hand Movement Training in Open Surgery.

We introduce a smart sensor-based motion detection technique for objective measurement and assessment of surgical dexterity among users at different experience levels. The goal is to allow trainees to evaluate their performance based on a reference model shared through communication technology, e.g., the Internet, without the physical presence of an evaluating surgeon. While in the current implementation we used a Leap Motion Controller to obtain motion data for analysis, our technique can be applied to motion data captured by other smart sensors, e.g., OptiTrack. To differentiate motions captured from different participants, measurement and assessment in our approach are achieved using two strategies: (1) low level descriptive statistical analysis, and (2) Hidden Markov Model (HMM) classification. Based on our surgical knot tying task experiment, we can conclude that finger motions generated from users with different surgical dexterity, e.g., expert and novice performers, display differences in path length, number of movements and task completion time. In order to validate the discriminatory ability of HMM for classifying different movement patterns, a non-surgical task was included in our analysis. Experimental results demonstrate that our approach had 100 % accuracy in discriminating between expert and novice performances. Our proposed motion analysis technique applied to open surgical procedures is a promising step towards the development of objective computer-assisted assessment and training systems.

Clinical translation of MS-based, quantitative plasma proteomics: status, challenges, requirements, and potential.

INTRODUCTION: Aided by the advent of advanced mass spectrometry (MS)-based technologies and methodologies, quantitative proteomics has emerged as a viable technique to capture meaningful data for candidate biomarker evaluation. To aid clinical translation, these methods generally utilize a bottom-up strategy with isotopically labeled standards and a targeted form of MS measurement. AREAS COVERED: This article reviews the status, challenges, requirements, and potential of translating current, MS-based methods to the clinical laboratory. The described methods are discussed and contrasted within a fit-for-purpose approach, while different resources for quality control, quantitative analysis, and data interpretation are additionally provided. Expert commentary: Although great strides have been made over the past five years in developing reliable quantitative assays for plasma protein biomarkers, it is crucial for investigators to have an understanding of the clinical validation process, a major roadblock in translational research. Continued progress in method design and validation of protein assays is necessary to ultimately achieve widespread adoption and regulatory approval.

Prevailing Trends in Haptic Feedback Simulation for Minimally Invasive Surgery.

Background The amount of direct hand-tool-tissue interaction and feedback in minimally invasive surgery varies from being attenuated in laparoscopy to being completely absent in robotic minimally invasive surgery. The role of haptic feedback during surgical skill acquisition and its emphasis in training have been a constant source of controversy. This review discusses the major developments in haptic simulation as they relate to surgical performance and the current research questions that remain unanswered. Search Strategy An in-depth review of the literature was performed using PubMed. Results A total of 198 abstracts were returned based on our search criteria. Three major areas of research were identified, including advancements in 1 of the 4 components of haptic systems, evaluating the effectiveness of haptic integration in simulators, and improvements to haptic feedback in robotic surgery. Conclusions Force feedback is the best method for tissue identification in minimally invasive surgery and haptic feedback provides the greatest benefit to surgical novices in the early stages of their training. New technology has improved our ability to capture, playback and enhance to utility of haptic cues in simulated surgery. Future research should focus on deciphering how haptic training in surgical education can increase performance, safety, and improve training efficiency.

Targeted quantitation of CVD-linked plasma proteins for biomarker verification and validation.

Despite significant advances in treatment, cardiovascular disease (CVD) remains one of the leading causes of morbidity and mortality in developed and developing countries. Judicious monitoring of common risk factors has been unable to control this global epidemic, necessitating novel biomarkers for improved screening and earlier disease detection and management. Although numerous plasma proteins have been associated with CVD, only a few of these potential biomarkers have been validated for clinical use. Here we review the quantitative proteomic methods used to verify and validate new biomarker candidates in human plasma. These methods center on a bottom-up approach involving multiple or selected reaction monitoring, for targeted detection, with stable isotope-labeled standards, for peptide normalization. Also included are a discussion of future strategies for improved CVD protein biomarker verification and validation, recommendations for method translation to the clinic, and future projections for protein biomarker research.

Angiotensin-converting enzyme 2 suppresses pathological hypertrophy, myocardial fibrosis, and cardiac dysfunction.

BACKGROUND: Angiotensin-converting enzyme 2 (ACE2) is a pleiotropic monocarboxypeptidase capable of metabolizing several peptide substrates. We hypothesized that ACE2 is a negative regulator of angiotensin II (Ang II)-mediated signaling and its adverse effects on the cardiovascular system. METHODS AND RESULTS: Ang II infusion (1.5 mg x kg(-1) x d(-1)) for 14 days resulted in worsening cardiac fibrosis and pathological hypertrophy in ACE2 knockout (Ace2(-/y)) mice compared with wild-type (WT) mice. Daily treatment of Ang II-infused wild-type mice with recombinant human ACE2 (rhACE2; 2 mg x kg(-1) x d(-1) IP) blunted the hypertrophic response and expression of hypertrophy markers and reduced Ang II-induced superoxide production. Ang II-mediated myocardial fibrosis and expression of procollagen type I alpha 1, procollagen type III alpha 1, transforming growth factor-beta1, and fibronectin were also suppressed by rhACE2. Ang II-induced diastolic dysfunction was inhibited by rhACE2 in association with reduced plasma and myocardial Ang II and increased plasma Ang 1-7 levels. rhACE2 treatment inhibited Ang II-mediated activation of protein kinase C-alpha and protein kinase C-beta1 protein levels and phosphorylation of the extracellular signal-regulated 1/2, Janus kinase 2, and signal transducer and activator of transcription 3 signaling pathways in wild-type mice. A subpressor dose of Ang II (0.15 mg . kg(-1) . d(-1)) resulted in a milder phenotype that was strikingly attenuated by rhACE2 (2 mg x kg(-1) x d(-1) IP). In adult ventricular cardiomyocytes and cardiofibroblasts, Ang II-mediated superoxide generation, collagen production, and extracellular signal-regulated 1/2 signaling were inhibited by rhACE2 in an Ang 1-7-dependent manner. Importantly, rhACE2 partially prevented the development of dilated cardiomyopathy in pressure-overloaded wild-type mice. CONCLUSIONS: Elevated Ang II induced hypertension, myocardial hypertrophy, fibrosis, and diastolic dysfunction, which were exacerbated by ACE2 deficiency, whereas rhACE2 attenuated Ang II- and pressure-overload-induced adverse myocardial remodeling. Hence, ACE2 is an important negative regulator of Ang II-induced heart disease and suppresses adverse myocardial remodeling.

Case report: necrotizing enterocolitis with a transverse colonic perforation in a 2-day old term neonate and literature review.

BACKGROUND: Necrotizing enterocolitis (NEC), while classically discussed in preterm and low birth weight neonates, also occurs in the term infant and accounts for 10% of all NEC cases. Despite there being fewer reported cases of NEC in term infants, these presentations demonstrate differences in the onset, severity and risk factors from the classic presentation observed in premature infants. We present a novel case of term NEC that contravenes the reported literature making departures from clinical presentation, risk factors and location of perforation in an otherwise healthy term two-day old infant born after an uncomplicated pregnancy who presented with hematochezia. CASE PRESENTATION: A healthy term baby born after an uneventful pregnancy presented with bloody stool at 2 days of life who was otherwise well. Investigations revealed pneumoperitoneum from a large proximal transverse colonic perforation secondary to NEC. No typical risk factors for NEC were found. CONCLUSION: Given the life-threatening potential of an unrecognized perforation we recommend the inclusion of NEC on the differential for neonatal hematochezia.

Concurrent Laparoscopic Ventral Hernia Repair with Bariatric Surgery: a Propensity-Matched Analysis.

BACKGROUND: Ventral hernias are a common finding during bariatric surgery; however, the risks and benefits of repair during surgery remain unclear. Using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database, we examined the short-term outcomes of patients undergoing bariatric surgery with concurrent ventral hernia repair (VHR) versus bariatric surgery alone. METHODS: Patients undergoing laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) were included. A propensity-matched analysis was performed between laparoscopic bariatric surgery with and without concurrent VHR. The primary outcome was the 30-day major complication rate which includes but is not limited to 30-day reoperation, deep surgical site infection, and sepsis. Secondary outcomes included operative time, length of hospital stay, 30-day readmission, and 30-day mortality. RESULTS: A total of 430,225 patients were included, of which 4690 (1.1%) received concomitant VHR. With one-to-one propensity score matching, 4648 pairs were selected. Concurrent VHR was associated with a higher major complication rate (5.8 vs 3.8%, p < 0.001) but no significant difference in mortality (0.3 vs 0.2%, p = 0.531). Both LSG with VHR (3.2 vs 2.4%, p = 0.007) and RYGB with VHR (9.3 vs 5.7%, p < 0.001) were associated with an increase in major complications. CONCLUSIONS: Patients undergoing VHR during bariatric surgery do not experience higher mortality. However, these patients have an elevated risk of major complications with this risk being higher among patients undergoing VHR and LRYGB. Bariatric surgeons should consider these risks when choosing to perform VHR at the time of bariatric surgery.

Simultaneous Cu-, Fe-, and Zn-specific detection of metalloproteins contained in rabbit plasma by size-exclusion chromatography-inductively coupled plasma atomic emission spectroscopy.

Analytical methods which are capable of determining the plasma or serum metalloproteome have inherent diagnostic value for human diseases associated with increased or decreased concentrations of specific plasma metalloproteins. We have therefore systematically developed a method to rapidly determine the major Cu-, Fe-, and Zn-containing metalloproteins in rabbit plasma (0.5 mL) based on size-exclusion chromatography (SEC; stationary phase Superdex 200, mobile phase phosphate-buffered saline pH 7.4) and the simultaneous online detection of Cu, Fe, and Zn in the column effluent by an inductively coupled plasma atomic emission spectrometer (ICP-AES). Whereas most previous studies reported on the analysis of serum, our investigations clearly demonstrated that the analysis of plasma within 30 min of collection results in the detection of one more Cu peak (blood coagulation factor V) than has been previously reported (transcuprein, ceruloplasmin, albumin-bound Cu, and small molecular weight Cu). The average amount of Cu associated with these five proteins corresponded to 21, 18, 21, 30 and 10% of total plasma Cu, respectively. In contrast, only two Fe metalloproteins (ferritin and transferrin, corresponding to an average of 9 and 91% of total plasma Fe) and approximately five Zn metalloproteins (alpha(2)-macroglobulin and albumin-bound Zn, which corresponded to an average of 10 and 57% of total [corrected] plasma Zn) were detected. Metalloproteins were assigned on the basis of the coelution of the corresponding metal and protein identified by immunoassays or activity-based enzyme assays. The SEC-ICP-AES approach developed allowed the determination of approximately 12 Cu, Fe, and Zn metalloproteins in rabbit plasma within approximately 24 min and can be applied to analyze human plasma, which is potentially useful for diagnosing Cu-, Fe-, and Zn-related diseases.

Concomitant pseudomembranous colitis in colonic resection for acute diverticulitis.

Diverticulitis and Clostridium difficile infection (CDI) are common conditions in the surgical population. However, they are usually 2 distinct clinical entities. Here, we report the case of acute diverticulitis with concomitant pseudomembranous colitis, presumably due to CDI. The clinical course as well as gross and microscopic pathology findings are discussed. A literature search revealed a single previous report of these findings concomitant in a surgical specimen. A brief discussion of the pathophysiology of CDI and acute diverticulitis is included.

Endoscopic revision (StomaphyX) versus formal surgical revision (gastric bypass) for failed vertical band gastroplasty.

BACKGROUND: Weight regain secondary to VBG pouch dilation is a typical referral for Bariatric surgeons. In this study we compare an endoluminal pouch reduction (Stomaphyx) to RYGB for revision. METHODS: A retrospective review was completed for patients with a previous VBG presenting with weight regain between 2003-2010. RESULTS: Thirty patients were identified for study 23 RYGB, 14 StomaphyX. Significant post procedure BMI loss was seen in each cohort (RYGB, 47.7 ± 7 kg/m(2) to 35 ± 7 kg/m(2); StomaphyX 43 ± 10 kg/m(2) to 40 ± 9 kg/m(2), P = 0.0007). Whereas nausea and headache were the only complications observed in StomaphyX patients, the RYGB group had a 43.5% complication rate and 1 mortality. Complications following RYGB include: incisional hernia (13%), anastomotic leak (8.7%), respiratory failure (8.7%), fistula (8.7%), and perforation (4.35%). The median length of stay following RYGB was 6 days compared to 1.5 ± 0.5 days following StomaphyX. CONCLUSION: This study suggests that while RYGB revision may achieve greater weight loss, the complication rates and severity is discouraging. StomaphyX may be a safe alternative. Further technical modifications of the device and longer follow-up may clarify the role of this approach.

Conformational Analysis of Oligoarabinofuranosides: Overcoming Torsional Barriers with Umbrella Sampling.

In this report, the conformations of a series of mono- and oligoarabinofuranosides were probed through the use of umbrella sampling simulations with the AMBER force field and the GLYCAM carbohydrate parameter set. The rotamer population distribution about the exocyclic C4-C5 bonds and the puckering distributions of the rings obtained from these umbrella sampling simulations were found to be in excellent agreement with those obtained from conventional long MD simulations for small monosaccharide fragments. For larger systems, the conventional MD approach becomes impractical, and we propose the use of umbrella sampling to circumvent poor sampling of certain conformations. The same umbrella sampling simulations were used to calculate the distributions about the vicinal protons and ensemble-averaged vicinal proton-proton coupling constants ((3)JH,H). The distributions about the vicinal protons of a monomer, methyl-α-l-arabinofuranoside (1), were found to be very similar to those obtained from direct umbrella sampling simulations about the vicinal protons. We calculated (3)JH,H based on DFT-based Karplus-like relationships for l-arabinofuranosides. The (3)JH,H values were found to be very similar to those obtained with the conventional MD simulations. For 1, the (3)JH,H values obtained with the DFT-based Karplus equations agree very well with experimental results; the agreement is, however, not as good for the larger oligomers. An approach to determine the experimental rotamer populations from the simulations is also discussed.

Molecular basis of arabinobio-hydrolase activity in phytopathogenic fungi: crystal structure and catalytic mechanism of Fusarium graminearum GH93 exo-alpha-L-arabinanase.

The phytopathogenic fungus Fusarium graminearum secretes a very diverse pool of glycoside hydrolases (GHs) aimed at degrading plant cell walls. alpha-l-Arabinanases are essential GHs participating in the complete hydrolysis of hemicellulose, a natural resource for various industrial processes, such as bioethanol or pharmaceuticals production. Arb93A, the exo-1,5-alpha-l-arabinanase of F. graminearum encoded by the gene fg03054.1, belongs to the GH93 family, for which no structural data exists. The enzyme is highly active (1065 units/mg) and displays a strict substrate specificity for linear alpha-1,5-l-arabinan. Biochemical assays and NMR experiments demonstrated that the enzyme releases alpha-1,5-l-arabinobiose from the nonreducing end of the polysaccharide. We determined the crystal structure of the native enzyme and its complex with alpha-1,5-l-arabinobiose, a degradation product of alpha-Me-1,5-l-arabinotetraose, at 1.85 and 2.05A resolution, respectively. Arb93A is a monomeric enzyme, which presents the six-bladed beta-propeller fold characteristic of sialidases of clan GHE. The configuration of the bound arabinobiose is consistent with the retaining mechanism proposed for the GH93 family. Catalytic residues were proposed from the structural analysis, and site-directed mutagenesis was used to validate their role. They are significantly different from those observed for GHE sialidases.