Design and testing of an optical instrument for skin flap monitoring.

Flap procedures are complex surgical tools widely used in reconstructive surgery. Flap ischemia is one of the most dangerous complications, both during the surgical procedure and during the patient's recovery, which can quickly lead to tissue necrosis (flap loss) with serious medical and psychological consequences. Today, bedside clinical assessment remains the gold standard for flap monitoring, but timely detection of flap ischemia is a difficult and challenging task, so auxiliary techniques are needed to support flap monitoring. Here we present a prototype of a new optical diagnostic tool, based on visible light absorption in diffuse reflectance spectroscopy, for non-invasive, continuous, real-time monitoring of flaps. The proposed approach is assessed by monitoring flap ischemic scenarios induced on pig animal models. The results obtained support that the proposed approach has great potential, not only for prompt detection of ischemia (in seconds), but also for clear differentiation between an arterial occlusion and venous occlusion.

Sclerosing angiomatoid nodular transformation (SANT) of the spleen: review of the literature.

We present a sclerosing angiomatoid nodular transformation (SANT) case report in a 60 year-old-woman. SANT is an extremely rare benign disease of the spleen that it is radiologically similar to malignant tumors, and clinically difficult to differentiate from other splenic diseases. Splenectomy is both diagnostic and therapeutic in symptomatic cases. The analysis of the resected spleen is necessary to achieve the final diagnosis of SANT.

An Electrochemical Immunosensor for the Determination of Procalcitonin Using the Gold-Graphene Interdigitated Electrode.

Procalcitonin (PCT) is considered a sepsis and infection biomarker. Herein, an interdigitated electrochemical immunosensor for the determination of PCT has been developed. The interdigitated electrode was made of the laser-engraved graphene electrode decorated with gold (LEGE/Aunano). The scanning electron microscopy indicated the LEGE/Aunano has been fabricated successfully. After that, the anti-PTC antibodies were immobilized on the surface of the electrode by using 3-mercaptopropionic acid. The electrochemical performance of the fabricated immunosensor was studied using electrochemical impedance spectroscopy (EIS). The EIS method was used for the determination of PCT in the concentration range of 2.5-800 pg/mL with a limit of detection of 0.36 pg/mL. The effect of several interfering agents such as the C reactive protein (CRP), immunoglobulin G (IgG), and human serum albumin (HSA) was also studied. The fabricated immunosensor had a good selectivity to the PCT. The stability of the immunosensor was also studied for 1 month. The relative standard deviation (RSD) was obtained to be 5.2%.

A photo-electrochemical aptasensor for the determination of severe acute respiratory syndrome coronavirus 2 receptor-binding domain by using graphitic carbon nitride-cadmium sulfide quantum dots nanocomposite.

Herein, a photoelectrochemical aptasensor for the quantitive measurement of the severe acute respiratory syndrome coronavirus-2 receptor-binding domain (Sars-Cov-2 RBD) has been reported for the first time. For this purpose, first, graphitic carbon nitride and (gC3N4) and cadmium sulfide (CdS) quantum dots were fabricated and characterized. After that, gC3N4 and CdS were mixed well. The fabricated nanomaterials were characterized by scanning transmission electron microscopy. Then, the CdS QDs-gC3N4 nanocomposite was added to the solution containing chitosan as an amine-rich polymer to generate a Chitosan/CdS-gC3N4 nanocomposite. Subsequently, the surface of the ITO electrode was modified with Chitosan/CdS-gC3N4. After that, the amine-terminal aptamer probes were immobilized on the surface of the Chitosan/CdS QDs-gC3N4/ITO electrode by using glutaraldehyde as an amine-amine crosslinker. The electrochemical performances of the electrodes were studied using cyclic voltammetry (CV), electrochemical Impedance Spectroscopy (EIS), and photo-electrochemistry (PEC). The surface coverage of the immobilized aptamer probe was founded to be 26.2 pmol.cm-2. The obtained results demonstrated that the proposed photo-electrochemical aptasensor can be used for the measurement of Sars-Cov-2 RBD within 0.5-32.0 nM. The limit of detection (LOD) was obtained to be 0.12 nM (at 3σ/slope). The affinity of the Aptamer/Chitosan/CdS QDs-gC3N4/ITO was also founded to be 3.4 nM by using Langmuir-typical adsorption systems. The proposed photo-electrochemical aptasensor was applied for the measurement of the spiked Sars-Cov-2 RBD in human saliva samples at two concentrations. The effect of the interfering biomaterials such as human immunoglobulin G human immunoglobulin A, human immunoglobulin M, and human serum albumin was also studied.

External Prospective Validation of the Modified CriSTAL Score for 30- and 90-day Mortality in Geriatric Urgent Surgical Patients.

OBJECTIVE: This study aimed to determine the predictive accuracy of the modified clinical prognostic tool Criteria for Screening and Triaging to Appropriate aLternative care (CriSTAL) to predict 30-day and 90-day mortality in older patients undergoing urgent abdominal surgery. BACKGROUND: Anticipating the mid-term mortality of older patients undergoing urgent surgery is complex and flawed with uncertainty. METHODS: A prospective study of consecutive ≥ 65 years old presenting at the emergency department who subsequently underwent urgent abdominal surgery. The modified CriSTAL score was calculated in the sample using the FRAIL scale instead of the Clinical Frailty Scale. Discrimination (area under the receiver-operating characteristic (AUROC)) and model calibration were used to test the predictive accuracy of the modified CriSTAL score for death within 30-day mortality as the primary outcome. RESULTS: A total of 500 patients (median age 78 years) were enrolled. The observed 30-day and 90-day mortality rate were 11.6% and 13.6%. The modified CriSTAL tool AUROC curve to predict 30-day and 90-day mortality was 0.78 and 0.77. The model was well calibrated according to the Hosmer-Lemeshow test (p: 0.302) and the calibration plots to predict 30-day and 90-day mortality. CONCLUSIONS: The modified CriSTAL tool (with FRAIL scale as frailty instrument) had good discriminant power and was well calibrated to predict 30-day and 90-day mortality in elderly patients undergoing urgent abdominal surgery. The modified CriSTAL tool is an easy preoperative tool that could assist in the prognosis of postoperative outcomes and decision-making discussions with patients before for urgent abdominal surgery.

Real-Time Impedance Monitoring of Epithelial Cultures with Inkjet-Printed Interdigitated-Electrode Sensors.

From electronic devices to large-area electronics, from individual cells to skin substitutes, printing techniques are providing compelling applications in wide-ranging fields. Research has thus fueled the vision of a hybrid, printing platform to fabricate sensors/electronics and living engineered tissues simultaneously. Following this interest, we have fabricated interdigitated-electrode sensors (IDEs) by inkjet printing to monitor epithelial cell cultures. We have fabricated IDEs using flexible substrates with silver nanoparticles as a conductive element and SU-8 as the passivation layer. Our sensors are cytocompatible, have a topography that simulates microgrooves of 300 µm width and ~4 µm depth, and can be reused for cellular studies without detrimental in the electrical performance. To test the inkjet-printed sensors and demonstrate their potential use for monitoring laboratory-growth skin tissues, we have developed a real-time system and monitored label-free proliferation, migration, and detachment of keratinocytes by impedance spectroscopy. We have found that variations in the impedance correlate linearly to cell densities initially seeded and that the main component influencing the total impedance is the isolated effect of the cell membranes. Results obtained show that impedance can track cellular migration over the surface of the sensors, exhibiting a linear relationship with the standard method of image processing. Our results provide a useful approach for non-destructive in-situ monitoring of processes related to both in vitro epidermal models and wound healing with low-cost ink-jetted sensors. This type of flexible sensor as well as the impedance method are promising for the envisioned hybrid technology of 3D-bioprinted smart skin substitutes with built-in electronics.

Prospective validation of the Urgent Surgery Elderly Mortality risk score (USEM).

INTRODUCTION: We aimed to test the predictive ability and to compare the predictive ability of the USEM to SRS, SORT and ASA in a prospective sample. PATIENTS AND METHODS: A Prospective cohort of >65-year-old patients undergoing urgent abdominal surgery in a Hospital. Models calibration and discrimination were evaluated using the receiver operating characteristics curves and the Hosmer-Lemeshow test. RESULTS: A total of 500 patients with a median age of 78 years were included. The AUROC in the validation cohort was 0.824. The USEM overestimated mortality (Test Hosmer-Lemeshow p < 0.001), after recalibration the USEM provided an accurate prediction of postoperative mortality. CONCLUSIONS: After the recalibration, the USEM had good discriminant power to estimate the risk of mortality in elderly patients after urgent abdominal surgery.

Prospective Study of Factors Associated With Postoperative Delirium After Urgent Abdominal Surgery. / Estudio prospectivo de los factores asociados al delirium en el postoperatorio de la cirugía abdominal urgente.

INTRODUCTION: Delirium is a frequent complication in elderly patients after urgent abdominal surgery. METHODS: Prospective study of consecutive patients aged ≥65years who had undergone urgent abdominal surgery from 2017-2019. The following variables were recorded: age, sex, ASA, physiological state, cognitive impairment, frailty (FRAIL Scale), functional dependence (Barthel Scale), quality of life (Euroqol-5D-VAS), nutritional status (MNA-SF), preoperative diagnosis, type of surgery (BUPA Classification), approach and diagnosis of postoperative delirium (Confusion Assessment Method). Univariate and multivariate analyses were performed to analyze the correlation of these variables with delirium. RESULTS: The study includes 446 patients with a median age of 78years, 63.6% were ASA ≥III and 8% had prior cognitive impairment. 13.2% were frail and 5.4% of the patients had a severe or total degree of dependence. 13.6% developed delirium in the postoperative period. In the univariate analysis, all the variables were statistically significant except for sex, type of surgery (BUPA) and duration. In the multivariate analysis the associated factors were: age (P<.001; OR: 1,08; 95%CI: 1,038-1,139), ASA (P=.026; OR: 3.15; 95%CI: 1.149-8.668), physiological state (P<.001; OR: 5.8; 95%CI: 2.176-15.457), diagnosis (P=.006) and cognitive impairment (P<.001; OR: 5.8; 95%CI: 2.391-14.069). CONCLUSION: The factors associated with delirium are age, ASA, physiological state in the emergency room, preoperative diagnosis and prior cognitive impairment.

The Urgent Surgery Elderly Mortality risk score: a simple mortality score.

INTRODUCTION: an increasing number of elderly patients undergo urgent abdominal surgery and this population has a higher risk of mortality. The main objective of the study was to identify mortality-associated factors in elderly patients undergoing abdominal surgery and to design a mortality scoring tool, the Urgent Surgery Elderly Mortality risk score (the USEM score). PATIENTS AND METHODS: this was a retrospective study using a prospective database. Patients > 65 years old that underwent urgent abdominal surgery were included. Risk factors for 30-day mortality were identified using multivariate regression analysis and weights assigned using the odds ratios (OR). A mortality score was derived from the aggregate of weighted scores. Model calibration and discrimination were judged using the receiver operating characteristics curves and the Hosmer-Lemeshow test. RESULTS: in the present study, 4,255 patients were included with an 8.5% mortality rate. The risk factors significantly associated with mortality were American Society of Anesthesiologists (ASA) score, age, preoperative diagnosis (OR: 37.82 for intestinal ischemia, OR: 5.01 for colorectal perforation, OR: 6.73 for intestinal obstruction), surgical wound classification and open or laparoscopic surgery. A risk score was devised from these data for the estimation of the probability of survival in each patient. The area under the ROC curve (AUROC) for this score was 0.84 (95% CI: 0.82-0.86) and the AUROC correct was 0.83 (0.81-0.85). CONCLUSIONS: a simple score that uses five clinical variables predicts 30-day mortality. This model can assist surgeons in the initial evaluation of an elderly patient undergoing urgent abdominal surgery.

Survival, morbidity and mortality of pancreatic adenocarcinoma after pancreaticoduodenectomy with a total mesopancreas excision.

INTRODUCTION: pancreatic adenocarcinoma is the most common malignancy in the periampullary region, with a five-year survival rate around 20%. OBJECTIVE: the goal of our study was to determine the survival and safety data of a number of patients that underwent a cephalic duodenopancreatectomy (CDP) with total mesopancreas excision (TMPE). MATERIAL AND METHODS: a prospective observational study was performed of 114 patients with pancreatic adenocarcinoma who underwent duodenopancreatectomy and TMPE over the period 2008-2017. Demographic variables, tumor stage, number of lymph nodes excised, lymph node ratio, R classification, the prognostic factor disease-free interval and survival were all assessed in a multivariate analysis. RESULTS: complications were reported for 54 (47.3%) patients, of which 22 (19.3%) were categorized as serious. The mortality rate was 4.3% and the mean follow-up was 26.2 months. During this period, 73 (64%) patients relapsed after a mean interval of 40.9 months. The relapse pattern was mainly hepatic (26.3%), followed by local relapse (20%). Mean survival was 40.38 and actuarial survival was 26.6% at five years. Relapse-related factors included stage T3 or higher (RR 8.1 [1.1-61]) and an R1 resection (RR 13.4 [2.7-66.5]) and survival-related factors included an R1 resection (RR 10.7 [2.5-46.2]). CONCLUSION: TMPE ensures an adequate lymphadenectomy and lymph node ratio according to reported standards. The survival of patients that have undergone surgery for pancreatic adenocarcinoma in our institution is 68.4% at one year and 26.6% at five years. An R1 resection is the primary factor for both relapse and survival.

Intraductal papillary mucinous neoplasm of the main duct in a patient with pancreas divisum.

Pancreas divisum is a congenital anomaly present in 5-10% of the population and is usually asymptomatic. Pancreatic intraductal papillary mucinous neoplasms (IPMN) are mucinous cystic tumors that have malignant potential and are classified according to their location as IPMN of the main duct, branch duct or mixed type. Larger lesions and those originating in the main duct have an increased risk of malignancy. The real incidence is unknown as most lesions are asymptomatic.

Delayed gastric emptying following pancreatoduodenectomy: a Roux-en-Y gastrojejunostomy vs Billroth II gastrojejunostomy randomized study.

INTRODUCTION: delayed gastric emptying (DGE) is the most common complication after pancreaticoduodenectomy (PD) and it occurs in 50% of cases. OBJECTIVES: the endpoint was to determine if there were any differences in the incidence of DGE between Roux-en-Y gastrojejunostomy (ReY) and Billroth II gastrojejunostomy (BII) in PD with pancreaticogastrostomy (PG). METHODS: this was a case-control prospective randomized study of all PD cases between 2013 and 2016. Sixty-four patients were included, 32 in each group. An intention-to-treat statistical analysis was performed. RESULTS: no significant differences were found with regard to morbidity and mortality or hospital stay. DGE was present in 25% of the patients in the BII group in comparison to 15.6% in the ReY group, which was not statistically significant (p = 0.35). There was a higher percentage of patients with primary DGE in the BII group, 12.5% versus 6.2%, but this was not statistically significant (p = 0.53). No difference in DGE severity was observed. Male gender (OR 8.38 [1.1; 129]), abdominal complications (OR 15 [1.7; 396.9]), pre-operative malnutrition (OR 99.7 [3.3, 11,126]) and hemorrhage (OR 9.4 [1.37, 107.94]) were the main risk factors for DGE according to the multivariate analysis. CONCLUSIONS: there were no significant differences in the incidence or severity of DGE between BII or ReY after PD with PG.

Stable and Potent Selenomab-Drug Conjugates.

Selenomabs are engineered monoclonal antibodies with one or more translationally incorporated selenocysteine residues. The unique reactivity of the selenol group of selenocysteine permits site-specific conjugation of drugs. Compared with other natural and unnatural amino acid and carbohydrate residues that have been used for the generation of site-specific antibody-drug conjugates, selenocysteine is particularly reactive, permitting fast, single-step, and efficient reactions under near physiological conditions. Using a tailored conjugation chemistry, we generated highly stable selenomab-drug conjugates and demonstrated their potency and selectivity in vitro and in vivo. These site-specific antibody-drug conjugates built on a selenocysteine interface revealed broad therapeutic utility in liquid and solid malignancy models.

Site-Specific Proteomic Mapping Identifies Selectively Modified Regulatory Cysteine Residues in Functionally Distinct Protein Networks.

S-Acylation, S-glutathionylation, S-nitrosylation, and S-sulfenylation are prominent, chemically distinct modifications that regulate protein function, redox sensing, and trafficking. Although the biological significance of these modifications is increasingly appreciated, their integration in the proteome remains unknown. Novel mass spectrometry-based technologies identified 2,596 predominately unique sites in 1,319 mouse liver proteins under physiological conditions. Structural analysis localized the modifications in unique, evolutionary conserved protein segments, outside commonly annotated functional regions. Contrary to expectations, propensity for modification did not correlate with biophysical properties that regulate cysteine reactivity. However, the in vivo chemical reactivity is fine-tuned for specificity, demonstrated by the nominal complementation between the four modifications and quantitative proteomics which showed that a reduction in S-nitrosylation is not correlated with increased S-glutathionylation. A comprehensive survey uncovered clustering of modifications within biologically related protein networks. The data provide the first evidence for the occurrence of distinct, endogenous protein networks that undergo redox signaling through specific cysteine modifications.

Quality standards in 480 pancreatic resections: a prospective observational study.

Pancreatic resection is a standard procedure for the treatment of periampullary tumors. Morbidity and mortality are high, and quality standards are scarce in our setting. International classifications of complications (Clavien-Dindo) and those specific for pancreatectomies (ISGPS) allow adequate case comparisons. The goals of our work are to describe the morbidity and mortality of 480 pancreatectomies using the international classifications ISGPS and Clavien-Dindo to help establish a quality standard in our setting and to compare the results of CPD with reconstruction by pancreaticogastrostomy (1,55) versus 177 pancreaticojejunostomy). We report 480 resections including 337 duodenopancreatectomies, 116 distal pancreatectomies, 11 total pancreatectomies, 10 central pancreatectomies, and 6 enucleations. Results for duodenopancreatectomy include: 62 % morbidity (Clavien > or = III 25.9 %), 12.3 % reinterventions, and 3.3 % overall mortality. For reconstruction by pancreaticojejunostomy: 71.2 % morbidity (Clavien > or = III 34.4 %), 17.5 % reinterventions, and 3.3 % mortality. For reconstruction by pancreaticogastrostomy: 51 % morbidity (Clavien > or = III 15.4%), 6.4 % reinterventions, and 3.2 % mortality. Differences are significant except for mortality. We conclude that our series meets quality criteria as compared to other groups. Reconstruction with pancreaticogastrostomy significantly reduces complication number and severity, as well as pancreatic fistula and reintervention rates.

Proteomic analysis of peptides tagged with dimedone and related probes.

Owing to its labile nature, a new role for cysteine sulfenic acid (-SOH) modification has emerged. This oxidative modification modulates protein function by acting as a redox switch during cellular signaling. The identification of proteins that undergo this modification represents a methodological challenge, and its resolution remains a matter of current interest. The development of strategies to chemically modify cysteinyl-containing peptides for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis has increased significantly within the past decade. The method of choice to selectively label sulfenic acid is based on the use of dimedone or its derivatives. For these chemical probes to be effective on a proteome-wide level, their reactivity toward -SOH must be high to ensure reaction completion. In addition, the presence of an adduct should not interfere with electrospray ionization, the efficiency of induced dissociation in MS/MS experiments or with the identification of Cys-modified peptides by automated database searching algorithms. Herein, we employ a targeted proteomics approach to study the electrospray ionization and fragmentation effects of different -SOH specific probes and compared them to commonly used alkylating agents. We then extend our study to a whole proteome extract using shotgun proteomic approaches. These experiments enable us to demonstrate that dimedone adducts do not interfere with electrospray by suppressing the ionization nor impede product ion assignment by automated search engines, which detect a + 138 Da increase from unmodified peptides. Collectively, these results suggest that dimedone can be a powerful tool to identify sulfenic acid modifications by high-throughput shotgun proteomics of a whole proteome.

Ischemic preconditioning protects cardiomyocyte mitochondria through mechanisms independent of cytosol.

Mitochondria play a central role in the protection conferred by ischemic preconditioning (IP) by not fully elucidated mechanisms. We investigated whether IP protects mitochondria against ischemia-reperfusion (IR) injury through mechanisms independent of cytosolic signaling. In isolated rat hearts, sublethal IR increased superoxide production and reduced complex-I- and II-mediated respiration in subsarcolemmal (SS), but not interfibrillar (IF) mitochondria. This effect of IR on mitochondrial respiration was significantly attenuated by IP. Similar results were obtained in isolated cardiac mitochondria subjected to in vitro IR. The reduction in SS mitochondrial respiration in the heart and in vitro model was paralleled by an increase in oxidized cysteine residues, which was also prevented by IP. IP was also protective in mitochondria submitted to lethal IR. The protective effect of IP against respiratory failure was unaffected by inhibition of mitochondrial KATP channels or mitochondrial permeability transition. However, IP protection was lost in mitochondria from genetically-modified animals in which connexin-43, a protein present in SS but not IF mitochondria, was replaced by connexin-32. Our results demonstrate the existence of a protective mitochondrial mechanism or "mitochondrial preconditioning" independent of cytosol that confers protection against IR-induced respiratory failure and oxidative damage, and requires connexin-43.

Application of iTRAQ Reagents to Relatively Quantify the Reversible Redox State of Cysteine Residues.

Cysteines are one of the most rarely used amino acids, but when conserved in proteins they often play critical roles in structure, function, or regulation. Reversible cysteine modifications allow for potential redox regulation of proteins. Traditional measurement of the relative absolute quantity of a protein between two samples is not always necessarily proportional to the activity of the protein. We propose application of iTRAQ reagents in combination with a previous thiol selection method to relatively quantify the redox state of cysteines both within and between samples in a single analysis. Our method allows for the identification of the proteins, identification of redox-sensitive cysteines within proteins, and quantification of the redox status of individual cysteine-containing peptides. As a proof of principle, we applied this technique to yeast alcohol dehydrogenase-1 exposed in vitro to H(2)O(2) and also in vivo to the complex proteome of the Gram-negative bacterium Bacillus subtilis.

A robust method for quantitative high-throughput analysis of proteomes by 18O labeling.

MS-based quantitative proteomics plays an increasingly important role in biological and medical research and the development of these techniques remains one of the most important challenges in mass spectrometry. Numerous stable isotope labeling approaches have been proposed. However, and particularly in the case of (18)O-labeling, a standard protocol of general applicability is still lacking, and statistical issues associated to these methods remain to be investigated. In this work we present an improved high-throughput quantitative proteomics method based on whole proteome concentration by SDS-PAGE, optimized in-gel digestion, peptide (18)O-labeling, and separation by off-gel isoelectric focusing followed by liquid chromatography-LIT-MS. We demonstrate that the off-gel technique is fully compatible with (18)O peptide labeling in any pH range. A recently developed statistical model indicated that partial digestions and methionine oxidation do not alter protein quantification and that variances at the scan, peptide, and protein levels are stable and reproducible in a variety of proteomes of different origin. We have also analyzed the dynamic range of quantification and demonstrated the practical utility of the method by detecting expression changes in a model of activation of Jurkat T-cells. Our protocol provides a general approach to perform quantitative proteomics by (18)O-labeling in high-throughput studies, with the added value that it has a validated statistical model for the null hypothesis. To the best of our knowledge, this is the first report where a general protocol for stable isotope labeling is tested in practice using a collection of samples and analyzed at this degree of statistical detail.