Pd-Catalyzed Formal [2 + 2]-Retrocyclization of Cyclobutanols via 2-Fold Csp3-Csp3 Bond Cleavage.

In this work, we describe the unexpected 2-fold Csp3-Csp3 bond cleavage suffered by cyclobutanols in the presence of a catalytic amount of Pd(OAc)2 and promoted by the bulky biaryl JohnPhos ligand. Overall, the sequential cleavage of a strained and an unstrained Csp3-Csp3 bond leads to the formal [2 + 2]-retrocyclization products, namely, styrene and acetophenone derivatives. This procedure might enable the use of cyclobutanols as masked acetyl groups, resisting harsh conditions in organic synthesis.

Versatility of the medial corticoperiosteal flap: from recalcitrant non-unions up to large bony defects.

BACKGROUND: Reconstructive microsurgery techniques using vascularized bone grafts have revolutionized the treatment of complex cases associated with recalcitrant non-unions or osteomyelitis. The medial femoral corticoperiosteal flap (MFCP flap) has emerged as a valuable option in bone reconstruction. Its clinical applications have been extended over the years considering this flap from non-unions with minimal bone lost, up to large intercalary defects of the upper and lower extremities. This article aims to present the clinical applications and outcomes of the MFCP flap in various reconstructive scenarios. METHODS: Seventy-nine patients with persistent non-union and bone defects of the upper and lower limb were evaluated from June 2008 to October 2020. All of them were reconstructed with a corticoperiosteal flap from the medial femoral condyle in our hospital. Previous procedures, bone gap and type of flap used were recorded. Postoperative functional status was assessed with time of bone healing, complications and clinical final outcome. RESULTS: Radiological evidence of bone union was observed at 4.09 months (range 2-9). Healing rate was 97% with periosteal corticocancellous flaps (PCC flaps) and 93% with corticoperiosteal flaps (CP flaps). Average follow-up was 14.5 months (range 5-28). There were no significant donor site complications. CONCLUSIONS: The MFCP flap offers a versatile and reliable option for bone reconstruction. Its ability to provide vascularized bone tissue with low morbidity enhances the healing process and improves outcomes. The MFCP flap has been increasing its applications and it serves as a valuable option in the treatment of recalcitrant non-unions or bony defects irrespective of site and size up to 5 cm in the upper and lower extremities.

Left renal vein graft and in situ hepatic perfusion in hepatectomy for complete tumor invasion of hepatic veins: hemodynamic optimization and surgical technique.

PURPOSE: Assessing hepatic vein reconstruction using a left renal vein graft and in situ hypothermic liver perfusion in an extended liver resection. METHODS: Patients included in this study were those with liver tumors undergoing curative surgery with resection and reconstruction of hepatic veins. Hepatic vein was reconstructed using a left renal vein graft. We describe the technical aspects of liver resection and vascular reconstruction, the key aspects of hemodynamic management, and the use of in situ hypothermic liver preservations during liver transection (prior to and during vascular clamping). RESULTS: The right hepatic vein was reconstructed with a median left renal venal graft length of 4.5 cm (IQR, 3.1-5.2). Creatinine levels remained within normal limits in the immediate postoperative phase and during follow-up. Median blood loss was 500 ml (IQR, 300-1500) and in situ perfusion with cold ischemia was 67 min (IQR, 60.5-77.5). The grafts remained patent during the follow-up with no signs of thrombosis. No major postoperative complications were observed. CONCLUSION: Left renal vein graft for the reconstruction of a hepatic vein and in situ hypothermic liver perfusion are feasible during extended liver resection.

Arthroscopic findings and long-term outcomes in 76 sport horses with meniscal injuries (2008-2018).

OBJECTIVE: To report the findings and long-term outcome of 76 sport horses with meniscal injury. STUDY DESIGN: Retrospective case series. ANIMALS: Seventy-six horses with 93 meniscal injuries in 85 stifles. METHODS: Medical records of sport horses diagnosed with meniscal injury during arthroscopy were reviewed. Owner follow up was obtained via telephone interview ≥1.5 years postoperatively. Preoperative and intraoperative findings, and postoperative treatments, were analyzed for potential association with return to athletic performance. RESULTS: The medial meniscus was involved in 82.8% of cases, with grade 1 injuries diagnosed in 76.3% of menisci. Overall, 85.5% of horses returned to athletic performance, with 40% returning to their previous level. The grade of meniscal injury was associated with long-term outcome (P = .023). The presence of preoperative radiographic abnormalities (P = .259) or additional joint pathology (P = 1.00) was not associated with long-term outcomes. Fifty-nine stifles were treated with an orthobiologic: autologous conditioned serum, platelet-rich plasma, or marrow-derived mesenchymal stem cells. There was no association between the use of any orthobiologic and long-term outcome (P = .394). CONCLUSION: This is the first report on long-term outcome of sport horses with meniscal injuries following arthroscopic surgery. Overall, the long-term prognosis was fair, with 40% of horses returning to their previous level of use. Severity of the meniscal injury was a prognostic indicator for return to work. The presence of radiographic abnormalities or additional joint pathology, or the use of orthobiologics, was not associated with long-term outcome. CLINICAL SIGNIFICANCE: These findings can help in prognostication for sport horses with meniscal injuries.

Baseline haemoglobin and thromboelastometry are predictive of red blood cell requirements and one-year mortality in liver transplantation.

BACKGROUND: To determine the predictive capacity of baseline haemoglobin and maxim clot firmness (MCF) EXTEM thromboelastometry for intraoperative red blood cell (RBC) requirements and its influence on mortality. METHODS: 591 adult liver transplant (LT) recipients from ten Spanish centres were reviewed. The main outcomes were the percentage of patients who received RBC and massive transfusion (≥ 6 RBC units), RBC units transfused, and mortality. RESULTS: 76 % received a donor after brain death graft and 24 % a controlled donor after circulatory death graft. Median (interquartile ranges) RBC transfusion was 2 (0-4) units, and 63 % of patients were transfused. Comparing transfused and non-transfused patients, mean (standard deviation) for baseline haemoglobin was 10.4 (2.1) vs. 13.0 (1.9) g/dl (p = 0.001), EXTEM MCF was 51(11) vs. 55(9) mm (p = 0.001). Haemoglobin and EXTEM MCF were inversely associated with the need of transfusion odds ratio (OR) of 0.558 (95 % CI 0.497-0.627, p < 0.001) and OR 0.966 (95 % CI0.945-0.987, p = 0.002), respectively. Pre-operative baseline haemoglobin ≤ 10 g/dL predicted RBC transfusion, sensitivity of 93 % and specificity of 47 %. Massive transfusion (MT) was received by 19 % of patients. Haemoglobin ≤10 g/dL predicted MT with sensitivity 73 % and specificity of 52 %. One-year patient and graft survival were significantly lower in patients who required MT (78 % and 76 %, respectively) vs. those who did not (94 % and 93 %, respectively). DISCUSSION: whereas EXTEM MCF is less dreterminant predicting RBC requirements, efforts are required to improve preoperative haemoglobin up to 10 g/dl in patients awaiting LT.

Etiology and Prognosis of Pneumonia in Patients with Solid Tumors: A Prospective Cohort of Hospitalized Cases.

BACKGROUND: Data on the incidence, etiology, and prognosis of non-ventilator-associated pneumonia in hospitalized patients with solid tumors are scarce. We aimed to study the characteristics of non-ventilator-associated pneumonia in hospitalized patients with solid tumors. MATERIALS AND METHODS: This was a prospective noninterventional cohort study of pneumonia in patients hospitalized in an oncology ward in a tertiary teaching hospital. Pneumonia was defined according to the American Thoracic Society criteria. Patients were followed for 1 month after diagnosis or until discharge. Survivors were compared with nonsurvivors. RESULTS: A total of 132 episodes of pneumonia were diagnosed over 1 year (9.8% of admissions to the oncology ward). They were health care-related (67.4%) or hospital-acquired pneumonia (31.8%). Lung cancer was the most common malignancy. An etiology was established in 48/132 episodes (36.4%). Knowing the etiology led to changes in antimicrobial therapy in 58.3%. Subsequent intensive care unit admission was required in 10.6% and was linked to inappropriate empirical therapy. Ten-day mortality was 24.2% and was significantly associated with hypoxia (odds ratio [OR], 2.1). Thirty-day mortality was 46.2%. The independent risk factors for 30-day mortality were hypoxia (OR, 3.3), hospital acquisition (OR, 3.1), and a performance status >1 (OR, 2.6). Only 40% of patients who died within 30 days were terminally ill. CONCLUSION: Pneumonia is a highly prevalent condition in hospitalized patients with solid tumors, even with nonterminal disease. Etiology is diverse, and poor outcome is linked to inappropriate empirical therapy. Efforts to get the empirical therapy right and reach an etiological diagnosis to subsequently de-escalate are warranted. IMPLICATIONS FOR PRACTICE: The present study shows that pneumonia is a prevalent infectious complication in patients admitted to oncology wards, with a very high mortality, even in non-terminally ill patients. Etiology is diverse, and etiological diagnosis is reached in fewer than 40% of cases in nonintubated patients. Intensive care unit admission, a marker of poor outcome, is associated with inappropriate empirical therapy. These results suggest that, to improve prognosis, a more precise and appropriate antimicrobial empirical therapy for pneumonia in patients with solid tumors is necessary, together with an effort to reach an etiological diagnosis to facilitate subsequent de-escalation.

Magnetic resonance dacryocystography in the horse: A feasibility study.

OBJECTIVE: To provide a comprehensive anatomical description of the normal equine nasolacrimal duct using magnetic resonance imaging, and to develop a practical protocol for performing magnetic resonance dacryocystography (MRD) in horses. ANIMAL STUDIED: The heads of ten fresh horse cadavers with no history of sinonasal or ophthalmologic disorders were used for this study. PROCEDURE: An MRD technique was developed in this study, which consisted of two parts. In the first part, olive oil and gadolinium were compared as contrast medium, using five horses. Two concentrations of gadolinium were used: 0.25 mmol/mL and 0.5 mmol/mL. In the second part, the influence of different head recumbencies using olive oil as the sole contrast medium was studied in the remaining five horses. RESULTS: Injection with olive oil resulted in better distention and a complete filling of the nasolacrimal duct (ND) in all horses. Injection of 0.25 mmol/mL of gadolinium resulted in incomplete filling of the ND, whereas injection of 0.5 mmol/mL of gadolinium resulted in slightly better filling of the duct. The nondependent duct showed better distention compared to the dependent duct when scanning in lateral recumbency. No differences were observed between ducts in a dorsal recumbency. The degree of distention in dorsal recumbency was slightly less than the degree of distention observed in the nondependent ND in lateral recumbency. CONCLUSIONS: Magnetic resonance dacryocystography is a suitable technique for evaluating the nasolacrimal duct and can be performed during a normal magnetic resonance examination.

Recent Advances on Synthetic Methodology Merging C-H Functionalization and C-C Cleavage.

The functionalization of C-H bonds has become a major thread of research in organic synthesis that can be assessed from different angles, for instance depending on the type of catalyst employed or the overall transformation that is carried out. This review compiles recent progress in synthetic methodology that merges the functionalization of C-H bonds along with the cleavage of C-C bonds, either in intra- or intermolecular fashion. The manuscript is organized in two main sections according to the type of substrate in which the cleavage of the C-C bond takes place, basically attending to the scission of strained or unstrained C-C bonds. Furthermore, the related research works have been grouped on the basis of the mechanistic aspects of the different transformations that are carried out, i.e.,: (a) classic transition metal catalysis where organometallic intermediates are involved; (b) processes occurring via radical intermediates generated through the use of radical initiators or photochemically; and (c) reactions that are catalyzed or mediated by suitable Lewis or Brønsted acid or bases, where molecular rearrangements take place. Thus, throughout the review a wide range of synthetic approaches show that the combination of C-H and C-C cleavage in single synthetic operations can serve as a platform to achieve complex molecular skeletons in a straightforward manner, among them interesting carbo- and heterocyclic scaffolds.

Long-term prognosis for return to athletic function after interspinous ligament desmotomy for treatment of impinging and overriding dorsal spinous processes in horses: 71 cases (2012-2017).

OBJECTIVE: To determine the long-term return to performance of horses with impinging and/or overriding dorsal spinous processes (ORDSP) treated with interspinous ligament desmotomy (ISLD) and to determine the prognostic value of radiographic and scintigraphic grades. STUDY DESIGN: Retrospective study. ANIMALS: Seventy-one horses with ORDSP treated with ISLD. METHODS: Medical records were reviewed for signalment, physical examination, gait evaluation, and number of interspinous spaces treated. Preoperative radiographic and scintigraphic images were evaluated with grading scales. Follow-up was obtained with a telephone questionnaire. Prognostic value of the number of affected interspinous spaces, radiographic grading, and scintigraphic grading was tested by using a χ2 test. RESULTS: A median follow-up of 35 months (range, 8-64) was available for 56 horses. Fifty-one of 56 (91.1%) horses returned to some level of performance, with 27 of 51 (52.9%) horses achieving equivalent or higher level of performance. Achieving a lower level of performance was attributed to recurrent back pain in nine of 24 (37.5%) horses and to unassociated lameness in nine of 24 (37.5%) horses. Owners of 44 of 56 (78.6%) horses were satisfied with the postoperative performance level, and owners of 46 of 56 (82.1%) horses would recommend the procedure. None of the variables tested influenced the return to performance. CONCLUSION: Interspinous ligament desmotomy allowed horses with ORDSP to return to some level of performance, although fewer returned to an equivalent or higher level of performance than had previously been reported. CLINICAL SIGNIFICANCE: Interspinous ligament desmotomy allows affected horses to return to some level of performance, regardless of the severity of radiographic and scintigraphic findings.

Neck, Back, and Pelvic Pain in Sport Horses.

Pain localized to the neck, back, and or pelvis can result in a profound effect on the horse's performance. These conditions can present with a varied and nonspecific set of clinical signs. A careful and thorough examination of these areas by means of physical examination, lameness evaluation both in hand and under saddle, diagnostic anesthesia, and the use of multiple imaging modalities in combination is often necessary to have an accurate prognosis. Medical and surgical management where appropriate of the conditions highlighted in this article are discussed as well as their individual prognosis.

Synthesis of biaryls using aryne intermediates.

The synthesis of biaryls from benzyne intermediates offers an alternative strategy to conventional metal-catalyzed cross-coupling approaches. The concept is as old as benzyne itself, being the basis of Wittig's seminal observations on biphenyl synthesis from phenyl lithium and fluorobenzene in 1940. In the intervening 75 years, the transformation has grown to encompass a remarkable scope of reaction classes, and continues to develop as new benzyne precursors enable inventive biaryl syntheses under mild conditions. This review will cover all aryne methods relevant to biaryl synthesis, drawing together key ideas from the older literature involving halobenzene precursors, with a more comprehensive coverage of modern methods using 2-(trimethylsilyl)phenyl triflates and tri-ynes as the source of benzyne. Collectively, we hope to highlight the power of aryne chemistry to access a huge range of biaryl structures from a versatile and highly customizable set of substrates.

Angular Limb Deformities: Growth Augmentation.

Angular limb deformities are seen in young foals and are defined as lateral or medial deviations of the limb in the frontal plane distal to a particular joint. Several factors can contribute to the development of an angular limb deformity. Early assessment of the level of ossification of the cuboidal bones is critical to avoid complications long term. Although most deviations self-correct with minimal intervention other than modifications in exercise and hoof trimming, some require surgical intervention in the form of growth acceleration or retardation. This article focuses on growth augmentation techniques, such as hemicircumferential transection and elevation.

Impact of Mean Cell Hemoglobin on Hb A1c-Defined Glycemia Status.

BACKGROUND: Several hematological alterations are associated with altered hemoglobin A1c (Hb A1c). However, there have been no reports of their influence on the rates of exceeding standard Hb A1c thresholds by patients for whom Hb A1c determination is requested in clinical practice. METHODS: The initial data set included the first profiles (complete blood counts, Hb A1c, fasting glucose, and renal and hepatic parameters) of all adult patients for whom such a profile was requested between 2008 and 2013 inclusive. After appropriate exclusions, 21844 patients remained in the study. Linear and logistic regression models were adjusted for demographic, hematological, and biochemical variables excluded from the predictors. RESULTS: Mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV) correlated negatively with Hb A1c. Fasting glucose, MCH, and age emerged as predictors of Hb A1c in a stepwise regression that discarded sex, hemoglobin, MCV, mean corpuscular hemoglobin concentration (MCHC), serum creatinine, and liver disease. Mean Hb A1c in MCH interdecile intervals fell from 6.8% (51 mmol/mol) in the lowest (≤27.5 pg) to 6.0% (43 mmol/mol) in the highest (>32.5 pg), with similar results for MCV. After adjustment for fasting glucose and other correlates of Hb A1c, a 1 pg increase in MCH reduced the odds of Hb A1c-defined dysglycemia, diabetes and poor glycemia control by 10%-14%. CONCLUSIONS: For at least 25% of patients, low or high MCH or MCV levels are associated with increased risk of an erroneous Hb A1c-based identification of glycemia status. Although causality has not been demonstrated, these parameters should be taken into account in interpreting Hb A1c levels in clinical practice.

Trapping σ-Alkyl-Palladium(II) Intermediates with Arynes Encompassing Intramolecular C-H Activation: Spirobiaryls through Pd-Catalyzed Cascade Reactions.

A palladium-catalyzed cascade reaction based on the trapping of transient alkyl-PdII intermediates with arynes encompassing a C-H activation step has been developed. This synthetic pathway gives rise to hetero-spirocyclic scaffolds containing a biaryl motif, and opens up new synthetic strategies in the design of cascade reactions since it gathers several aspects of Pd chemistry, i.e., intra- and intermolecular carbopalladation of unsaturated species, C-H activation and C-C coupling processes.

Use of a novel silk mesh for ventral midline hernioplasty in a mare.

BACKGROUND: Ventral midline hernia formation following abdominal surgery in horses is an uncommon complication; however, it can have serious consequences leading to increased morbidity and mortality. Currently, mesh hernioplasty is the treatment of choice for large ventral midline hernias in horses to allow potential return to normal function. Complications following mesh hernioplasty using polypropylene or polyester mesh in horses can be serious and similar to complications seen in human patients, including persistent incisional drainage, mesh infection, hernia recurrence, intra-abdominal adhesions, mesh or body wall failure, recurrent abdominal pain (colic), and peritonitis. This report describes the use of a novel bioresorbable silk mesh for repair of a large ventral midline incisional hernia in a mature, 600-kg horse. To our knowledge, this is the first report of its kind in the literature. CASE PRESENTATION: A 9-year-old, 600-kg Warmblood mare presented with a ventral midline hernia following emergency exploratory celiotomy 20 months prior. The mare was anesthetized and a hernioplasty was performed using a novel bioresorbable silk mesh (SERI(®) Surgical Scaffold; Allergan Medical, Boston, MA). No complications were encountered either intra- or postoperatively. The mare was discharged from the hospital at 3 days postoperatively in an abdominal support bandage. At 8 and 20 weeks postoperatively, ultrasonographic assessment showed evidence of tissue ingrowth within and around the mesh. The mare was able to be bred 2 years in a row, carrying both foals to full gestation with no complications. Following both foalings, the abdomen has maintained a normal contour with no evidence of hernia recurrence. CONCLUSIONS: Ventral abdominal hernias can be repaired in horses using a bioresorbable silk mesh, which provides adequate biomechanical strength while allowing for fibrous tissue ingrowth. The use of a bioresorbable silk mesh for the repair of ventral hernias can be considered as a realistic option as it potentially provides significant benefits over traditional non-resorbable mesh.

Magnetic resonance imaging characteristics of equine head disorders: 84 cases (2000-2013).

The equine head is an anatomically complex area, therefore advanced tomographic imaging techniques, such as computed tomography or magnetic resonance imaging (MRI), are often required for diagnosis and treatment planning. The purpose of this multicenter retrospective study was to describe MRI characteristics for a large sample of horses with head disorders. Horses imaged over a period of 13 years were recruited. Eighty-four horses met the inclusion criteria, having neurological (n = 65), sinonasal (n = 14), and soft tissue (n = 5) disorders. Magnetic resonance imaging accurately depicted the anatomy and allowed identification of the primary lesion and associated changes. There were good correlations between MRI findings and intraoperative or postmortem results. Magnetic resonance imaging showed the exact localization of the lesions, their size, and relation to surrounding structures. However, in the neurological group, there were 45 horses with no MRI abnormalities, 29 of which had a history of recurrent seizures, related to cryptogenic epilepsy. Magnetic resonance imaging was otherwise a valuable diagnostic tool, and can be used for studying a broad range of head disorders using either low-field or high-field magnets.

Double heteroatom functionalization of arenes using benzyne three-component coupling.

Arynes participate in three-component coupling reactions with N, S, P, and Se functionalities to yield 1,2-heteroatom-difunctionalized arenes. Using 2-iodophenyl arylsulfonates as benzyne precursors, we could effectively add magnesiated S-, Se-, and N-nucleophilic components to the strained triple bond. In the same pot, addition of electrophilic N, S, or P reagents and a copper(I) catalyst trapped the intermediate aryl Grignard to produce a variety of 1,2-difunctionalized arenes.

Management of bilateral patellar luxation in an alpaca.

OBJECTIVE: To report surgical management bilateral lateral patellar luxation in a mature alpaca using a combination of trochlear wedge recession (TWR), tibial tuberosity transposition (TTT), and joint capsule imbrication. STUDY DESIGN: Clinical case report. ANIMALS: 9-year-old castrated male Alpaca. METHODS: Bilateral, grade III/IV, lateral patellar luxation was identified by palpation, lameness examination and confirmed with radiography and ultrasonography. Surgical procedures were staged, with the left stifle treated first. Bilateral TWR, TTT, and joint capsule imbrication were performed. Outcome was assessed by radiography and follow up lameness examinations. RESULTS: An immediate improvement in weight bearing occurred after surgery of the left hind limb. Five months after initial surgery, right hind limb patella luxation was corrected. After surgery on the 2nd limb, the alpaca had progressive improvement in weight bearing during hospitalization. At 12 months, there were no signs of lameness and the alpaca had resumed normal activities. CONCLUSIONS: For bilateral lateral patellar luxation, a combination of TWR, TTT, and joint capsule imbrication resulted in excellent long-term outcome.

Ruthenium-catalyzed cascade C-H functionalization of phenylacetophenones.

Three orthogonal cascade CH functionalization processes are described, based on ruthenium-catalyzed CH alkenylation. 1-Indanones, indeno indenes, and indeno furanones were accessed through cascade pathways by using arylacetophenones as substrates under conditions of catalytic [{Ru(p-cymene)Cl2 }2 ] and stoichiometric Cu(OAc)2 . Each transformation uses CH functionalization methods to form CC bonds sequentially, with the indeno furanone synthesis featuring a CO bond formation as the terminating step. This work demonstrates the power of ruthenium-catalyzed alkenylation as a platform reaction to develop more complex transformations, with multiple CH functionalization steps taking place in a single operation to access novel carbocyclic structures.

Pd-Catalyzed Ring-Opening Polymerization of Cyclobutanols through C(sp3)-C(sp3) Bond Cleavage.

A new approach to ring-opening polymerization (ROP) based on C(sp3)-C(sp3) bond cleavage is reported. This process is based on the ability of Pd to promote both the ß-carbon elimination of a bifunctional cyclobutanol precursor and the C-C coupling process with the resulting Pd-alkyl intermediate. Consequently, novel polyketone materials are obtained. Owing to the modular synthesis of the used cyclobutanol monomers, the present ROP reaction allows the introduction of substitution patterns in the polymeric chain that are not accessible by current polyketone synthesis methodologies. We have explored in detail the initiation, propagation, and termination steps of this new polymerization process.