Chiral Control in Pentacoordinate Systems: The Case of Organosilicates.

Chirality at the central element of pentacoordinate systems can be controlled with two identical bidentate ligands. In such cases the topological Levi-Desargues graph for all the Berry pseudorotations (BPR, max. 20) reduces to interconnected inner and outer "circles" that represent the dynamic enantiomer pair. High enough barriers of the BPR crossovers between the two circles is all what is needed to ascertain chiral integrity. This is illustrated computationally and experimentally for the organosilicates 7 and 10 that carry besides a Me (a), Et (b), Ph (c), or F (d) group two bidentate 2-(phenyl)benzo[ b]-thiophene or 2-(phenyl)naphthyl ligands, respectively. The enantiomers of tetraorganosilane precursor 9 could be separated by column chromatography. Their chiral integrity persisted on forming the silicates. CD spectra are reported for 10c. Fluoro derivative 10d is shown to have its electronegative F substituent in an equatorial position, is stable toward hydrolysis, and its enantiomers do not racemize at ambient temperatures, while those of 10c racemize slowly.

The degenerative cervical spine. / La columna cervical degenerativa.

Imaging techniques provide excellent anatomical images of the cervical spine. The choice to use one technique or another will depend on the clinical scenario and on the treatment options. Plain-film X-rays continue to be fundamental, because they make it possible to evaluate the alignment and bone changes; they are also useful for follow-up after treatment. The better contrast resolution provided by magnetic resonance imaging makes it possible to evaluate the soft tissues, including the intervertebral discs, ligaments, bone marrow, and spinal cord. The role of computed tomography in the study of degenerative disease has changed in recent years owing to its great spatial resolution and its capacity to depict osseous components. In this article, we will review the anatomy and biomechanical characteristics of the cervical spine, and then we provide a more detailed discussion of the degenerative diseases that can affect the cervical spine and their clinical management.

Predictive value of the PRAETORIAN score for defibrillation test success in patients with subcutaneous ICD: A subanalysis of the PRAETORIAN-DFT trial.

BACKGROUND: The PRAETORIAN score estimates the risk of failure of subcutaneous implantable cardioverter-defibrillator (S-ICD) therapy by using generator and lead positioning on bidirectional chest radiographs. The PRospective randomized compArative trial of subcutanEous implanTable cardiOverter-defibrillatoR ImplANtation with and without DeFibrillation Testing (PRAETORIAN-DFT) investigates whether PRAETORIAN score calculation is noninferior to defibrillation testing (DFT) with regard to first shock efficacy in spontaneous events. OBJECTIVE: This prespecified subanalysis assessed the predictive value of the PRAETORIAN score for defibrillation success in induced ventricular arrhythmias. METHODS: This multicenter investigator-initiated trial randomized 965 patients between DFT and PRAETORIAN score calculation after de novo S-ICD implantation. Successful DFT was defined as conversion of induced ventricular arrhythmia in <5 seconds from shock delivery within 2 attempts. Bidirectional chest radiographs were obtained after implantation. The predictive value of the PRAETORIAN score for DFT success was calculated for patients in the DFT arm. RESULTS: In total, 482 patients were randomized to undergo DFT. Of these patients, 457 (95%) underwent DFT according to protocol, of whom 445 (97%) had successful DFT and 12 (3%) had failed DFT. A PRAETORIAN score of ≥90 had a positive predictive value of 25% for failed DFT, and a PRAETORIAN score of <90 had a negative predictive value of 99% for successful DFT. A PRAETORIAN score of ≥90 was the strongest independent predictor for failed DFT (odds ratio 33.77; confidence interval 6.13-279.95; P < .001). CONCLUSION: A PRAETORIAN score of <90 serves as a reliable indicator for DFT success in patients with S-ICD, and a PRAETORIAN score of ≥90 is a strong predictor for DFT failure.

SEMICYUC 2012. Recommendations for intensive care management of acute pancreatitis.

OBJECTIVE: Significant changes in the management of acute pancreatitis have taken place since the 2004 Pamplona Consensus Conference. The objective of this conference has been the revision and updating of the Conference recommendations, in order to unify the integral management of potentially severe acute pancreatitis in an ICU. PARTICIPANTS: Spanish and international intensive medicine physicians, radiologists, surgeons, gastroenterologists, emergency care physicians and other physicians involved in the treatment of acute pancreatitis. LEVELS OF EVIDENCE AND GRADES OF RECOMMENDATION: The GRADE method has been used for drawing them up. DRAWING UP THE RECOMMENDATIONS: The selection of the committee members was performed by means of a public announcement. The bibliography has been revised from 2004 to the present day and 16 blocks of questions on acute pancreatitis in a ICU have been drawn up. Firstly, all the questions according to groups have been drawn up in order to prepare one document. This document has been debated and agreed upon by computer at the SEMICYUC Congress and lastly at the Consensus Conference which was held with the sole objective of drawing up these recommendations. CONCLUSIONS: Eighty two recommendations for acute pancreatitis management in an ICU have been presented. Of these 84 recommendations, we would emphasize the new determinants-based classification of acute pancreatitis severity, new surgical techniques and nutritional recommendations. Note. This summary only lists the 84 recommendations of the 16 questions blocks except blocks greater relevance and impact of its novelty or because they modify the current management.

Toward Asymmetric Synthesis of Pentaorganosilicates.

Introducing chiral silicon centers was explored for the asymmetric Rh-catalyzed cyclization of dihydrosilanes to enantiomerically enriched spirosilanes as targets to enable access to enantiostable pentacoordinate silicates. The steric rigidity required in such systems demands the presence of two naphthyl or benzo[b]thiophene groups. The synthetic approach to the expanded spirosilanes extends Takai's method (Kuninobu et al. in Angew Chem Int Ed 52(5):1520-1522, 2013) for the synthesis of spirosilabifluorenes in which both a Si-H and a C-H bond of a dihydrosilane are activated by a rhodium catalyst. The expanded dihydrosilanes were obtained from halogenated aromatic precursors. Their asymmetric cyclization to the spirosilanes were conducted with [Rh(cod)Cl]2 in the presence of the chiral bidentate phosphane ligands (R)-BINAP, (R)-MeO-BIPHEP, and (R)-SEGPHOS, including derivatives with P-(3,5-t-Bu-4-MeO)-phenyl (DTBM) groups. The highest enantiomeric excess of 84% was obtained for 11,11'-spirobi[benzo[b]-naphtho[2,1-d]silole] with the DTBM-SEGPHOS ligand.

Tamoxifen and endometrial cancer. Is screening necessary? A review of the literature.

Tamoxifen is a selective oestrogen receptor modulator (SERM) with anti-oestrogenic activity in the breast and oestrogenic effects in various tissues such as the endometrium, bone and cardiovascular territory. As adjuvant hormone therapy, it has a clear beneficial effect in patients with breast cancer, reducing relapses, contralateral breast cancer and mortality. Its most important secondary effect is a greater rate of occurrence of endometrial cancer. Although the risk/benefit ratio is clearly positive, the follow-up on these patients is still an issue. In women with metrorrhagia, it is clear that an endometrial sample must be obtained for histological examination and the best procedure today is hysteroscopic-directed biopsy. Nevertheless, the need to screen asymptomatic patients is not universally accepted. The vaginal ultrasound scan gives a great number of false positives. This entails more aggressive and more expensive procedures such as hysteroscopic-directed biopsy, meaning greater expense and more complications. As a result, the cost/benefit ratio is not very favourable. The rate of occurrence of endometrial cancer in 1026 tamoxifen-treated patients with breast cancer in our hospital between 1999 and 2001 was 1.25%. Two cases were diagnosed in asymptomatic patients. In this article, we analyse the literature on the need to screen patients on tamoxifen and about the most appropriate diagnostic protocol.

Phrenic nerve paralysis following pediatric cardiac surgery. Role of diaphragmatic plication.

Eighteen children sustained unilateral phrenic nerve paralysis (PNP) after cardiac surgical procedures. Ten (Group I), under 7 months (mean: 2.9 +/- 2.2), required long-term ventilatory assistance (mean: 23.9 +/- 13.0 days); they failed to be weaned from the ventilator. All underwent diaphragmatic plication (DP). DP was performed late in 7 cases (Group Ia) with a mean time of 30.8 days between surgery and DP, and early in 3 others (Group Ib) with a mean time of 10.2 days. Eight children (Group II), older than 1 year, tolerated PNP better and could be extubated early without diaphragmatic plication. In Group Ia severe lung infections were recorded in 5 before or/and after DP, and two died at 3 and 30 days after plication. Five children from Group Ia and all 3 from Group Ib were late survivors. They could be weaned from ventilatory support in a mean time of 3 days after DP, although those with severe lung infection (Group Ia) took the longest time. All from Group II were late survivors. We conclude: PNP is well tolerated without plication in children older than 1 year. However early DP offers excellent and immediate results in infants with PNP. Early DP in these children avoids or reduces severe lung infections and death.

Aortopulmonary window with anomalous origin of the right coronary artery from the pulmonary trunk.

A case of aortopulmonary window associated with an anomalous origin of the right coronary artery from the pulmonary artery in a 3-month-old boy is reported. Angiographic diagnosis could be difficult because of the simultaneous filling of both great arteries that obscure the origin of the anomalous vessel; however, a careful evaluation of the angiogram may contribute to an accurate diagnosis. The surgical correction of this association of defects requires the connection of the aorta with the anomalous coronary ostium. An intrapulmonary tunneling procedure by means of a baffle is described.

[Surgery of congenital cardiopathies without previous catheterization. Preoperative evaluation and surgical indication using bidimensional echocardiography and Doppler]. / Cirugía de las cardiopatías congénitas sin cateterismo previo. Valoración preoperatoria e indicación quirúrgica por ecocardiografía bidimensional y Doppler.

With the non-invasive devices available nowadays, many congenital heart diseases may be diagnosed with a definition comparable and even perhaps superior to catheterization and angiography. According to this issue, from January 1983 to December 1987, 239 children underwent operations for palliation or correction of different cardiopathies based on an echo-Doppler assessment without prior catheterization. Preoperative echo-Doppler diagnoses had an adequate correlation with the surgical findings in 234 cases (97.9 percent), so there was no correlation in 5 cases. In general, we consider that echo-Doppler provides a complete and definitive diagnosis in most cases, thus eliminating the need for further invasive procedures, although we still have to rely on catheterization to obtain the necessary information or reassurance in some cases. Progressive increase of reliance in echo-Doppler techniques by the surgeon and self confidence of the cardiologist in his accurate state of the art will considerably increase the performance of cardiac operations without prior catheterization in the future. At present, this is our current policy, as day after day, we are increasing the diagnoses in which we consider unnecessary the catheterization to indicate surgery.

[Diagnostic value of quantitative cultures of endotracheal aspirate in ventilator-associated pneumonia: a multicenter study]. / Valor diagnóstico del cultivo cuantitativo del aspirado endotraqueal en la neumonía adquirida durante la ventilación mecánica. Estudio multicéntrico.

OBJECTIVE: To study the validity of quantitative cultures of tracheal aspirate (TA) in comparison with the plugged telescoping catheter (PTC) for the diagnosis of mechanical ventilator-associated pneumonia. METHOD: Prospective multicenter study enrolling patients undergoing mechanical ventilation for longer than 72 hours. TA samples were collected from patients with suspected ventilator-associated pneumonia, followed by PTC sampling. Quantitative cultures were performed on all samples. Patients were classified according to the presence or not of pneumonia, based on clinical and radiologic criteria, clinical course and autopsy findings. The cutoff points were > or = 103 colony-forming units (cfu)/mL for PTC cultures; the TA cutoffs analyzed were > or = 105 and > or = 106 cfu/mL. RESULTS: Of the 120 patients studied, 84 had diagnoses of pneumonia and 36 did not (controls). The sensitivity values for TA > or = 106, TA > or = 105, and PTC, respectively, were 54% (95% confidence interval [CI], 42%-64%), 71% (95% CI, 60%-81%), and 68% (95% CI, 57%-78%). The specificity values were 75% (95% CI, 58%-88%), 58% (95% CI, 41%-74%), and 75% (95% CI, 58%-88%), respectively. Staphylococcus aureus was the microorganism most frequently isolated in both TA and PTC samples, followed in frequency by Pseudomomonas aeruginosa in TA samples and Haemophilus influenzae in PTC samples. No significant differences were found between the sensitivity of TA > or = 105 and that of PTC, nor between the specificities of TA > or = 106 and PTC. CONCLUSIONS: No differences in the specificities of PTC and TA were found when a TA cutoff of > or = 106 cfu/ml was used. Moreover, at a cutoff of > or = 105 the sensitivity of TA was not statistically different from that of PTC. Quantitative cultures of TA can be considered acceptable for the diagnosis of ventilator-associated pneumonia.