Simultaneous Bilateral Video-Endoscopic Inguinal Lymphadenectomy for Penile Carcinoma: Surgical Setting, Feasibility, Safety, and Preliminary Oncological Outcomes.

INTRODUCTION: Inguinal lymph node dissection (ILND) plays an important role for both staging and treatment purposes in patients diagnosed with penile carcinoma (PeCa). Video-endoscopic inguinal lymphadenectomy (VEIL) has been introduced to reduce complications, and in those patients elected for bilateral ILND, a simultaneous bilateral VEIL (sB-VEIL) has also been proposed. This study aimed to investigate the feasibility, safety, and preliminary oncological outcomes of sB-VEIL compared to consecutive bilateral VEIL (cB-VEIL). MATERIAL AND METHODS: Clinical N0-2 patients diagnosed with PeCa and treated with cB-VEIL and sB-VEIL between 2015 and 2023 at our institution were included. Modified ILND was performed in cN0 patients, while cN+ patients underwent a radical approach. Intra- and postoperative complications, operative time, time of drainage maintenance, length of hospital stay and readmission within 90 days, as well as lymph node yield, were compared between the two groups. RESULTS: Overall, 30 patients were submitted to B-VEIL. Of these, 20 and 10 patients underwent cB-VEIL and sB-VEIL, respectively. Overall, 16 (80%) and 7 (70%) patients were submitted to radical ILND due to cN1-2 disease in the cB-VEIL and sB-VEIL groups, respectively. No statistically significant difference emerged in terms of median nodal yield (13.5 vs. 14, p = 0.7) and median positive LNs (p = 0.9). sD-VEIL was associated with a shorter operative time (170 vs. 240 min, p < 0.01). No statistically significant difference emerged in terms of intraoperative estimated blood loss, length of hospital stay, time to drainage tube removal, major complications, and hospital readmission in the cB-VEIL and sB-VEIL groups, respectively (all p > 0.05). CONCLUSIONS: Simultaneous bilateral VEIL is a feasible and safe technique in patients with PeCA, showing similar oncological results and shorter operative time compared to a consecutive bilateral approach. Patients with higher preoperative comorbidity burden or anesthesiological risk are those who may benefit the most from this technique.

A new machine-learning model to predict long-term renal function impairment after minimally invasive partial nephrectomy: the Fundació Puigvert predictive model.

PURPOSE: To provide a new model to predict long-term renal function impairment after partial nephrectomy (PN). METHODS: Data of consecutive patients who underwent minimally invasive PN from 2005 to 2022 were analyzed. A minimum of 12 months of follow-up was required. We relied on a machine-learning algorithm, namely classification and regression tree (CART), to identify the predictors and associated clusters of chronic kidney disease (CKD) stage migration during follow-up. RESULTS: 568 patients underwent minimally invasive PN at our center. A total of 381 patients met our inclusion criteria. The median follow-up was 69 (IQR 38-99) months. A total of 103 (27%) patients experienced CKD stage migration at last follow-up. Progression of CKD stage after surgery, ACCI and baseline CKD stage were selected as the most informative risk factors to predict CKD progression, leading to the creation of four clusters. The progression of CKD stage rates for cluster #1 (no progression of CKD stage after surgery, baseline CKD stage 1-2, ACCI 1-4), #2 (no progression of CKD stage after surgery, baseline CKD stage 1-2, ACCI ≥ 5), #3 (no progression of CKD stage after surgery and baseline CKD stage 3-4-5) and #4 (progression of CKD stage after surgery) were 6.9%, 28.2%, 37.1%, and 69.6%, respectively. The c-index of the model was 0.75. CONCLUSION: We developed a new model to predict long-term renal function impairment after PN where the perioperative loss of renal function plays a pivotal role to predict lack of functional recovery. This model could help identify patients in whom functional follow-up should be intensified to minimize possible worsening factors of renal function.

Optimizing decision-making process of benign uretero-enteric anastomotic stricture treatment after radical cystectomy.

PURPOSE: To identify preoperative predictors of endo-urological treatment (EUT) failure while promoting a new diagnostic and therapeutic pathway for benign uretero-enteric anastomosis stricture (UES) management after radical cystectomy (RC). MATERIALS AND METHODS: We relied on a prospectively maintained database including 96 individuals (122 renal units) who developed a benign UES at our institution between 1990 and 2018. UES was classified into two different types according to morphology: FP1 (i.e., sharp or duckbill) and FP2 (i.e., flat or concave). EUT feasibility, success rate, as well as intra and postoperative complications were recorded. Uni- and multivariable logistic regression analysis (MVA) assessed for predictors of EUT failure. RESULTS: Overall, 78 (63.9%) and 32 (26.3%) cases were defined as FP1 and FP2, respectively. EUT was not feasible in 33 (27.1%) cases. After a median follow-up of 50 (IQR 5-240) months, successful treatment was reached only in 15/122 (12.3%) cases. EUT success rates raised when considering short (< 1 cm) (16.8%), FP1 morphology (16.7%) strictures, or the combination of these characteristics (22.4%). Overall, 5 (5.2%) cases had CD ≥ III complications. FP2 (OR: 1.91, 95%CI 1.21-5.31, p = 0.03) and stricture length ≥ 1 cm (OR: 9.08, 95%CI 2.09-65.71, p = 0.009) were associated with treatment failure at MVA. CONCLUSIONS: Endoscopic treatment for benign UES after RC is feasible but harbors a low success rate. Stricture length and radiological morphology of the stricture are related to endoscopic treatment failure. Surgeons should be aware of the stricture features during the preoperative decision-making process to choose the optimal candidate for endoscopic treatment.

[Ultrasound-guided cryotherapy of small renal masses: Systematic review.] / Crioterapia renal guiada por ecografía para el tratamiento de masas renales de pequeño tamaño: revisión sistemática.

OBJECTIVE: Renal cryotherapy (RC) is an alternative therapeutic option to partial nephrectomy in elderly patients and/or patients with comorbidities. The technique can be guided by ultrasound, CT and MRI. Although CT is the most used technique, there are no comparative studies. The objective of this study was to review the current status of ultrasound as a guide for the planning and execution of RC. METHODS: A systematic review of the literature was carried out in the Pubmed/Medline database following the PRISMA guidelines. We used 42 articles that met the inclusion criteria for the synthesis of the evidence. RESULTS: Ultrasound allows dynamic and real-time monitoring of the entire procedure to guide the biopsy, placement of the cryoprobes, cryoball formation, and early identification of complications. The success rate and recurrences found in the percutaneous renal cryotherapy (PRC) were 97.04% and 1.81%, respectively, with 9.35% complications. The ultrasound during laparoscopic renal cryotherapy (LRC) has been shown to reduce the time spent in localizing the renal mass and also decreases the need for large dissections. On the other hand, contrast-enhanced ultrasound during follow-up shows a concordance with the CT or MRI of 72-96% and no complications have been described associated with its execution. CONCLUSION: Renal cryotherapy guided by ultrasound is a feasible technique, its main advantage is based on real-time monitoring during the procedure. The PRC presents an acceptable rate of complications and excellent oncological results. The LRC allows a rapid localization of the renal mass and reduces extensive dissections. During follow-up, the use of contrast ultrasound is a safe alternative that has been shown to have a good degree of agreement with respect to CT and MRI.

OBJETIVO: La crioterapia renal (CR) es una opción terapéutica alternativa a la nefrectomía parcial en pacientes de edad avanzada y/o comorbilidades. La técnica puede realizarse guiada por ecografía, TC y RM. Aunque la TC es la técnica mas utilizada, no existen estudios comparativos. El objetivo de este estudio fue revisar el estado actual de la ecografía como guía para la planificación y ejecución de la CR.MÉTODOS: Se llevó a cabo una revisión sistemática de la literatura en la base de datos Pubmed/Medline siguiendo las normas PRISMA. Se utilizaron 42 artículos que cumplieron los criterios de inclusión para la síntesis de la evidencia. RESULTADOS: La ecografía permite la monitorización dinámica y en tiempo real de todo el procedimiento permitiendo guiar la toma de biopsia, colocación de las criosondas, formación de la criobola, así como la identificación temprana de complicaciones. La tasa de éxito y recurrencias encontradas en la CR Percutánea (CRP) fue de 97,04% y 1,81%, respectivamente, con un 9,35 % de complicaciones. La ecografía en CR Laparoscópica (CRL) ha mostrado reducir el tiempo empleado en la localización de la masa renal e igualmente disminuye la necesidad de grandes disecciones. La ecografía con contraste durante el seguimiento muestra una concordancia con la TC o RMN de 72-96% y no se han descrito complicaciones asociadas a su ejecución.CONCLUSIÓN: La CR guiada por ecografía es una técnica factible cuya principal ventaja se basa en la monitorización a tiempo real durante el procedimiento. La CRP presenta tasa de complicaciones y resultados oncológicos aceptables. Mediante la CRL se puede realizar una localización rápida de la masa renal y reduce las disecciones extensas. Durante el seguimiento, el uso de la ecografía con contraste es una alternativa segura que ha mostrado tener buen grado de concordancia con respecto a la TC y la RMN.

Crioterapia renal guiada por ecografía para el tratamiento de masas renales de pequeño tamaño: revisión sistemática / Ultrasound-guided cryotherapy of small renal masses: Systematic review

Objetivo: La crioterapia renal (CR) es una opción terapéutica alternativa a la nefrectomía parcial en pacientes de edad avanzada y/o comorbilidades. La técnica puede realizarse guiada por ecografía, TC y RM. Aunque la TC es la técnica más utilizada, no existen estudios comparativos. El objetivo de este estudio fue revisar el estado actual de la ecografía como guía para la planificación y ejecución de la CR. Métodos: Se llevó a cabo una revisión sistemática de la literatura en la base de datos Pubmed/Medline siguiendo las normas PRISMA. Se utilizaron 42 artículos que cumplieron los criterios de inclusión para la síntesis de la evidencia. Resultados: La ecografía permite la monitorización dinámica y en tiempo real de todo el procedimiento permitiendo guiar la toma de biopsia, colocación de las criosondas, formación de la criobola, así como la identificación temprana de complicaciones. La tasa de éxito y recurrencias encontradas en la CR Percutánea (CRP) fue de 97,04% y 1,81%, respectivamente, con un 9,35 % de complicaciones. La ecografía en CR Laparoscópica (CRL) ha mostrado reducir el tiempo empleado en la localización de la masa renal e igualmente disminuye la necesidad de grandes disecciones. La ecografía con contraste durante el seguimiento muestra una concordancia con la TC o RMN de 72-96% y no se han descrito complicaciones asociadas a su ejecución. Conclusión: La CR guiada por ecografía es una técnica factible cuya principal ventaja se basa en la monitorización a tiempo real durante el procedimiento. La CRP presenta tasa de complicaciones y resultados oncológicos aceptables. Mediante la CRL se puede realizar una localización rápida de la masa renal y reduce las disecciones extensas. Durante el seguimiento, el uso de la ecografía con contraste es una alternativa segura que ha mostrado tener buen grado de concordancia con respecto a la TC y la RMN

Objective: Renal cryotherapy (RC) is an alternative therapeutic option to partial nephrectomy in elderly patients and/or patients with comorbidities. The technique can be guided by ultrasound, CT and MRI. Although CT is the most used technique, there are no comparative studies. The objective of this study was to review the current status of ultrasound as a guide for the planning and execution of RC. Methods: A systematic review of the literature was carried out in the Pubmed/Medline database following the PRISMA guidelines. We used 42 articles that met the inclusion criteria for the synthesis of the evidence. Results: Ultrasound allows dynamic and real-time monitoring of the entire procedure to guide the biopsy, placement of the cryoprobes, cryoball formation, and early identification of complications. The success rate and recurrences found in the percutaneous renal cryotherapy (PRC) were 97.04% and 1.81%, respectively, with 9.35% complications. The ultrasound during laparoscopic renal cryotherapy (LRC) has been shown to reduce the time spent in localizing the renal mass and also decreases the need for large dissections. On the other hand, contrast-enhanced ultrasound during follow-up shows a concordance with the CT or MRI of 72-96% and no complications have been described associated with its execution. Conclusion: Renal cryotherapy guided by ultrasound is a feasible technique, its main advantage is based on real-time monitoring during the procedure. The PRC presents an acceptable rate of complications and excellent oncological results. The LRC allows a rapid localization of the renal mass and reduces extensive dissections. During follow-up, the use of contrast ultrasound is a safe alternative that has been shown to have a good degree of agreement with respect to CT and MRI

Recellularization of Decellularized Venous Grafts Using Peripheral Blood: A Critical Evaluation.

Vascular disease is a major cause of death worldwide, and the growing need for replacement vessels is not fully met by autologous grafts or completely synthetic alternatives. Tissue engineering has emerged as a compelling strategy for the creation of blood vessels for reconstructive surgeries. One promising method to obtain a suitable vessel scaffold is decellularization of donor vascular tissue followed by recellularization with autologous cells. To prevent thrombosis of vascular grafts, a confluent and functional autologous endothelium is required, and researchers are still looking for the optimal cell source and recellularization procedure. Recellularization of a decellularized scaffold with only a small volume of whole blood was recently put forward as a feasible option. Here we show that, in contrast to the published results, this method fails to re-endothelialize decellularized veins. Only occasional nucleated cells were seen on the luminal surface of the scaffolds. Instead, we saw fibrin threads, platelets and scattered erythrocytes. Molecular remnants of the endothelial cells were still attached to the scaffold, which explains in part why earlier results were misinterpreted. Decellularized vascular tissues may still be the best scaffolds available for vascular tissue engineering. However, for the establishment of an adequate autologous endothelial lining, methods other than exposure to autologous whole blood need to be developed.

Infrainguinal inflow assessment and endovenous stent placement in iliofemoral post-thrombotic obstructions.

PURPOSE: To assess the technical success, patency, and clinical outcome, following assessment of inflow and infrainguinal endovenous stent placement in patients with iliofemoral post-thrombotic obstruction with infrainguinal involvement. METHODS: A retrospective analysis of 39 patients with iliofemoral post-thrombotic venous obstruction accepted for infrainguinal stent placement in the period November 2009-December 2016. The clinical status was categorized according to the Clinical Etiological Anatomical Pathophysiological (CEAP) classification and symptom severity was assessed using Venous Clinical Severity Score (VCSS). The inflow was categorized as "good", "fair", or "poor" depending on vein caliber and extent of post-thrombotic changes in the inflow vessel(s). Stent patency was assessed by duplex ultrasound. Median follow-up was 44 months (range 2-90 months). RESULTS: Stent placement was successful in all 39 patients. Primary patency after 24 months was 78%. Thirty of 39 patients (77%) had open stents at final follow-up. Re-interventions were performed in four patients and included catheter-directed thrombolysis (CDT) in all and adjunctive stenting in two. Twenty-eight of 39 patients (72%) reported a sustained clinical improvement. Patients with "good" inflow had better patency compared to those with "fair"/"poor" (p = 0.01). One patient experienced acute contralateral iliofemoral thrombosis; this segment was successfully treated with CDT and stenting. No other complications required intervention. CONCLUSION: Infrainguinal endovenous stent placement was a feasible and safe treatment with good patency and clinical results, and should be considered in patients with substantial symptoms from post-thrombotic obstructions with infrainguinal involvement. Stents with good inflow have better patency and inflow assessment is essential in deciding the optimal stent landing zone.

[Laparoscopic management of ureteroileal stenosis: Long term follow up.] / Manejo laparoscópico de la estenosis uretero­ileal con seguimiento a largo plazo.

OBJECTIVE: To describe the laparoscopic approach for uretero-ileal anastomosis strictures and to analyse our long term series. METHODS: A retrospective review was performed evaluating our series of patients with benign ureteroileal anastomosis strictures treated laparoscopically from 2011 to 2017. Demographics and perioperative data were obtained and analyzed. Complications were described with the Clavien-Dindo classification. The surgical technique was described and a literature review was performed. RESULTS: Eleven procedures were performed in ten patients. Mean blood loss was 180 ml. All the operations were performed laparoscopically without conversion. Mean hospital stay was 10 days (4-23). Early complications were Clavien-Dindo I y II: Two cases of limited anastomosis leakage, one lymphorrea, one paralitic ileum and one accidental descent of the ureteral catheter. Mean follow-up was 56 months (12-179) No late complications have been described. CONCLUSION: Based on our series with 5 year follow up, the laparoscopic approach for uretero-ileal anastomosis strictures is feasible and safe.

Manejo laparoscópico de la estenosis uretero-ileal con seguimiento a largo plazo / Laparoscopic management of ureteroileal stenosis: Long term follow up

OBJETIVO: El objetivo de este artículo es la descripción de la técnica laparoscópica para el tratamiento de las estenosis uretero-ileales tras la cistectomía radical y analizar nuestra serie a largo plazo. MÉTODOS: Se realizó una revisión retrospectiva de los pacientes tratados laparoscópicamente de EUI tras cistectomía radical desde el Enero de 2011 (año en el que se implementó la técnica) hasta Marzo de 2017. Se tomaron los datos perioperatorios y se clasificaron según la graduación Clavien-Dindo. Asimismo, se describió la técnica quirúrgica y se realizó una búsqueda en la literatura del tema. RESULTADOS: Diez pacientes con EUI fueron tratados laparoscópicamente realizando un total de 11 cirugías. La pérdida sanguínea intraoperatoria media fue de 180 ml. No hubo conversión a cirugía abierta. La estancia hospitalaria media fue 10 días (4-23). Las complicaciones postoperatorias tempranas fueron Clavien-Dindo I y II e incluyen dos fugas limitadas de la anastomosis, una linforrea, un íleo paralítico y un descenso accidental de catéter ureteral. La media de seguimiento de los pacientes fue 56 meses (rango 12-179). Hasta el momento no se observaron complicaciones tardías. CONCLUSIONES: El tratamiento laparoscópico de las EUI es seguro, factible y eficaz según nuestra experiencia con seguimiento de casi 5 años

OBJECTIVE: To describe the laparoscopic approach for uretero-ileal anastomosis strictures and to analyse our long term series. METHODS: A retrospective review was performed evaluating our series of patients with benign uretero-ileal anastomosis strictures treated laparoscopically from 2011 to 2017. Demographics and perioperative data were obtained and analyzed. Complications were described with the Clavien-Dindo classification. The surgical technique was described and a literature review was performed. RESULTS: Eleven procedures were performed in ten patients. Mean blood loss was 180 ml. All the operations were performed laparoscopically without conversion. Mean hospital stay was 10 days (4-23). Early complications were Clavien-Dindo I y II: Two cases of limited anastomosis leakage, one lymphorrea, one paralitic ileum and one accidental descent of the ureteral catheter. Mean follow-up was 56 months (12-179) No late complications have been described. CONCLUSION: Based on our series with 5 year follow up, the laparoscopic approach for uretero-ileal anastomosis strictures is feasible and safe

Cp2TiCl/D2O/Mn, a formidable reagent for the deuteration of organic compounds.

Cp2TiCl/D2O/Mn is an efficient combination, sustainable and cheap reagent that mediates the D-atom transfer from D2O to different functional groups and can contribute to the synthesis of new deuterated organic compounds under friendly experimental conditions and with great economic advantages.

Simple Laparoscopic Nephrectomy in Stone Disease: Not Always Simple.

OBJECTIVES: Simple nephrectomy is performed for a benign pathology that does not require the excision of either the adrenal gland or any adenopathies. When it is carried out in cases of stone disease, however, it is frequently not a "simple" technique owing to the presence of significant inflammation and infection. METHODS: Ninety-six simple laparoscopic nephrectomies performed because of stone disease between 2006 and 2015 were retrospectively studied. A descriptive statistical analysis was performed, as well as an evaluation of the associated complications. RESULTS: Of the 96 laparoscopic nephrectomies (62 left, 34 right), 7 (7.2%) had to be converted into open surgery owing to the impossibility of dissecting the renal hilum because of xanthogranulomatous pyelonephritis (n = 4) or major associated lesions (n = 3). The indication for nephrectomy was lumbar pain associated with urinary infection, with a partial renal function below 15% assessed by DMSA renal scan. There were three major complications. Pathologic assessment revealed chronic pyelonephritis with kidney atrophy and associated pyonephrosis in 85 cases, xanthogranulomatous pyelonephritis in 10, and pT4 squamous cell carcinoma in 1. CONCLUSIONS: Despite its high technical difficulty, simple laparoscopic nephrectomy for stones is a viable technique for advanced laparoscopists. Its principal advantage compared with open surgery is improved postsurgical recovery, and it is associated with an acceptable complication rate. Xanthogranulomatous pyelonephritis is not an initial contraindication to laparoscopy, but it is the most significant risk factor for conversion to open surgery.

Laparoscopic Management of Ureteroileal Anastomosis Strictures: Initial Experience.

BACKGROUND: A ureteroileal anastomosis stricture (UAS) is one of the most frequent complications after radical cystectomy. Open surgical repair is the treatment of choice but is associated with morbidity. OBJECTIVE: To describe the efficacy and safety of laparoscopic management for benign secondary UAS. DESIGN, SETTING, AND PARTICIPANTS: A review was performed of the 11 initial procedures performed at our academic center from December 2010 to December 2014, with mean follow-up of 38 mo (range 12-169). Patients included had benign ureteroileal strictures longer than 1cm. SURGICAL PROCEDURE: A pure laparoscopic approach was systematically used, involving a two-step procedure for left and a one-step procedure for right ureteral stenosis. MEASUREMENTS: Perioperative data were collected and complications were assessed using the Clavien-Dindo grading system. Outcomes and follow-up data were analyzed. RESULTS AND LIMITATIONS: A descriptive statistical analysis was performed for 11 surgeries in ten patients. The median stricture length was 2.4cm. No conversion to open surgery was required. The mean blood loss was 180ml and the mean hospital stay was 10 d. Early complications included limited lymphorrhea (n=1), limited anastomotic leakage (n=2), and accidental descent of a ureteral catheter (n=1) that was replaced with radiologic intervention. The mean follow-up was 38 mo (range 12-169). No late complications were reported. After 1 yr of follow-up, six patients had good glomerular filtration rates, all patients were asymptomatic, and no stenotic relapses were detected. CONCLUSIONS: This laparoscopic technique for the management of benign secondary UAS is feasible, with good results and without long-term complications. This minimally invasive approach reduces the morbidity associated with open surgery while retaining good success rates. PATIENT SUMMARY: We describe a novel laparoscopic approach for patients with a ureteroileal anastomosis stricture after radical cystectomy to avoid the complications associated with open surgery. The surgery was found to be viable and safe with good long-term results.

Synthesis of (±)-aureol by bioinspired rearrangements.

A bioinspired and sustainable procedure for the straightforward synthesis of (±)-aureol has been achieved in eight steps (14% overall yield) from epoxyfarnesol. The key steps are the titanocene(III)-catalyzed radical cascade cyclization of an epoxyfarnesol derivative and a biosynthetically inspired sequence of 1,2-hydride and methyl shifts.

Successful tissue engineering of competent allogeneic venous valves.

OBJECTIVE: The purpose of this study was to evaluate whether tissue-engineered human allogeneic vein valves have a normal closure time (competency) and tolerate reflux pressure in vitro. METHODS: Fifteen human allogeneic femoral vein segments containing valves were harvested from cadavers. Valve closure time and resistance to reflux pressure (100 mm Hg) were assessed in an in vitro model to verify competency of the vein valves. The segments were tissue engineered using the technology of decellularization (DC) and recellularization (RC). The decellularized and recellularized vein segments were characterized biochemically, immunohistochemically, and biomechanically. RESULTS: Four of 15 veins with valves were found to be incompetent immediately after harvest. In total, 2 of 4 segments with incompetent valves and 10 of 11 segments with competent valves were further decellularized using detergents and DNAse. DC resulted in significant decrease in host DNA compared with controls. DC scaffolds, however, retained major extracellular matrix proteins and mechanical integrity. RC resulted in successful repopulation of the lumen and valves of the scaffold with endothelial and smooth muscle cells. Valve mechanical parameters were similar to the native tissue even after DC. Eight of 10 veins with competent valves remained competent even after DC and RC, whereas the two incompetent valves remained incompetent even after DC and RC. The valve closure time to reflux pressure of the tissue-engineered veins was <0.5 second. CONCLUSIONS: Tissue-engineered veins with valves provide a valid template for future preclinical studies and eventual clinical applications. This technique may enable replacement of diseased incompetent or damaged deep veins to treat axial reflux and thus reduce ambulatory venous hypertension.

Selective reduction of aromatic ketones in aqueous medium mediated by Ti(III)/Mn: a revised mechanism.

An experimental study on the role played by each of the reagents involved in the selective reduction of aromatic ketones in aqueous medium is reported. In this reaction, the reduction of aromatic ketones is mediated by Cp2TiCl. Moreover, the presence of Mn in the reaction medium is mandatory. To account for these findings, a substantially revised mechanism is proposed.

Ti-catalyzed straightforward synthesis of exocyclic allenes.

Exocyclic allenes constitute useful building blocks in organic synthesis and have recently been identified as key intermediates in the synthesis of natural products. Here the first general method for the most straightforward synthesis of exocyclic allenes reported to date is presented. This method is based on the Barbier-type cyclization of propargyl halides catalyzed by titanium; a safe, abundant, and ecofriendly metal. The reaction proceeds under mild conditions compatible with different functional groups and provides good yields of five-, six-, and seven-membered carbocycles and nitrogen-containing heterocycles bearing an exocyclic allene group. Experimental evidence supporting the proposed reaction mechanism is also provided. Moreover, this procedure can be carried out in an enantioselective manner by using chiral titanocene(III) catalysts. The utility of this method has been proved in the synthesis of the natural alkaloid stemoamide.

Highly selective Barbier-type propargylations and allenylations catalyzed by titanocene(III).

The alkyne functional group is found in many bioactive natural products and is the key to many important chemical transformations developed over recent years. Moreover, allenes have recently gained relevance as versatile reagents in organic synthesis. Mild, catalytic methods to enable the selective introduction of either alkyne or allene motifs into organic molecules are very valuable but, as yet, quite scarce. We describe an extremely mild and selective method for either the propargylation or allenylation of carbonyl compounds catalyzed by the abundant, safe, and inexpensive metal titanium. These reactions can selectively provide homopropargylic alcohols from aldehydes and ketones or α-hydroxy-allenes from aldehydes. The mechanisms involved were also investigated.

Ti-catalyzed homolytic opening of ozonides: a sustainable C-C bond-forming reaction.

The unprecedented homolytic opening of ozonides promoted and catalyzed by titanocene(III) is reported. This novel reaction proceeds at room temperature under neutral, mild conditions compatible with many functional groups and provides carbon radicals suitable to form C-C bonds via both homocoupling and cross-coupling processes. The procedure has been advantageously exploited for the straightforward synthesis of the natural product brittonin A.

Hydrogen atom donors: recent developments.

This review highlights recent developments in the field of hydrogen atom transfer (HAT) reagents that circumvent the disadvantages of classical group 14 reagents, such as Bu3SnH. Special emphasis is laid on the lowering of bond dissociation energies (BDEs) of molecules that could, as yet, not be used as HAT reagents and on the use of organometallic HAT reagents.

Reducing inter-observer variability in embryo evaluation by means of training courses.

PURPOSE: To study the utility of a training session offered to junior embryologists, comparing the results obtained with those reported by a group of senior embryologists. METHODS: The 62 junior embryologists participanting were asked to decide on the quality of the embryos and theg clinical decision to be taken. RESULTS: The junior embryologists' success rate following the training course was significantly higher than before for embryo classification (48.4% ± 20.4 vs. 59.7% ±16.7) (p < 0.05) and for clinical decision (54.7% ± 19.6 vs. 68.7% ± 17.6) (p < 0.005). Comparison of the degree of agreement between the categories assigned by the junior embryologists and those assigned by consensus among the group of senior embryologists revealed kappa values of k = 0.32 before the course and of k = 0.54 after it. The comparison between pre- and post-training junior and senior embryologists also reflected an improvement in the kappa index for clinical decision, from k = 0.54 to k = 0.68. CONCLUSIONS: Training courses are shown to be an effective tool for increasing the degree of agreement between junior and senior embryologists.