Transanal full-thickness excision for rectal neoplasm: is it advisable to leave the defect open?

PURPOSE: After a full-thickness total wall excision of a rectal tumor, suturing the defect is generally recommended. Recently, due to various contradictory studies, there is a trend to leave the defects open. Therefore, this study aimed to determine whether leaving the defect open is an adequate management strategy compared with suturing it closed based on postoperative outcomes and recurrences. METHODS: A retrospective review of our prospectively maintained database was conducted. Adult patients who underwent transanal surgery for rectal neoplasm in our institution from 1997 to 2019 were analyzed. Patients were divided into two groups: sutured (group A) or unsutured (group B) rectal defect. The primary outcomes were morbidity (early and late) and recurrence. RESULTS: In total, 404 (239 men) patients were analyzed, 143 (35.4%) from group A and 261 (64.6%) from group B. No differences were observed in tumor size, distance from the anal verge or operation time. The overall incidence of complications was significantly higher in patients from group B, which nearly double the rate of group A. With a mean follow-up of 58 (range, 12-96) months, seven patients presented with a rectal stricture, all of them from group B. CONCLUSIONS: We acknowledge the occasional impossibility of closing the defect in patients who undergo local excision; however, when it is possible, the present data suggest that there may be advantages to suturing the defect closed.

Combined transposition of internal obturator and superficial gluteal muscles for perineal hernia treatment in dogs: 17 cases (2017-2020).

OBJECTIVES: To report the results of the combined transposition of the internal obturator muscle and superficial gluteal muscle for perineal hernia treatment in dogs. MATERIALS AND METHODS: Retrospective case series of dogs treated with this technique from November 2017 to May 2020, including pre- and post-operative clinical findings, outcome and complications. RESULTS: Seventeen dogs were included in the study. Twelve dogs were presented with unilateral perineal hernia and five dogs with bilateral perineal hernias. Mean duration of clinical signs before presentation was 9 months. All perineal hernias were successfully repaired using a transposition of the internal obturator muscle to cover the ventral aspect of the perineal hernia and the superficial gluteal muscle to cover the dorsal aspect of the hernia with minimal tension. All dogs regained normal defecation within 24 hours post-surgery. Average follow-up time was 16 months. No recurrence of clinical signs or rectal deviation was observed. Five dogs developed a superficial minor partial necrosis of the T-shaped incision and two had surgical site infections. CLINICAL SIGNIFICANCE: Perineal herniorrhaphy using a combined transposition of the internal obturator and the superficial gluteal muscles is feasible and offered excellent results in this cohort of dogs. It may be considered as a technique for repairing chronic and extensive unilateral and bilateral perineal hernias.

Theoretical and Experimental Study of CaMgSi Thermoelectric Properties.

Pure CaMgSi was successfully synthesized by mechanical milling, followed by spark plasma sintering. Rietveld refinement was used to calculate the structural parameters, where a crystallite size (D XRD) of 79 nm was estimated. This value was confirmed by the Williamson-Hall analysis. Transmission electron microscopy was used to analyze the microstructure, revealing the presence of extensive interfaces, nanoparticles, and a high crystallinity. First-principles calculations were performed with the WIEN2k package, finding a band gap of 0.27 eV. The thermoelectric properties were determined combining experimental measurements and theoretical results from the BoltzTraP code. The highest value of the electronic figure of merit (ZT e) was 1.67 at 415 K. However, when the lattice thermal contribution (k L) is considered, the highest value of the figure of merit (ZT) was 0.144 at 644 K.

HCN Channel Phosphorylation Sites Mapped by Mass Spectrometry in Human Epilepsy Patients and in an Animal Model of Temporal Lobe Epilepsy.

Because hyperpolarization-activated cyclic nucleotide-gated (HCN) ion channels modulate the excitability of cortical and hippocampal principal neurons, these channels play a key role in the hyperexcitability that occurs during the development of epilepsy after a brain insult, or epileptogenesis. In epileptic rats generated by pilocarpine-induced status epilepticus, HCN channel activity is downregulated by two main mechanisms: a hyperpolarizing shift in gating and a decrease in amplitude of the current mediated by HCN channels, Ih. Because these mechanisms are modulated by various phosphorylation signaling pathways, we hypothesized that phosphorylation changes occur at individual HCN channel amino acid residues (phosphosites) during epileptogenesis. We collected CA1 hippocampal tissue from male Sprague Dawley rats made epileptic by pilocarpine-induced status epilepticus, and age-matched naïve controls. We also included resected human brain tissue containing epileptogenic zones (EZs) where seizures arise for comparison to our chronically epileptic rats. After enrichment for HCN1 and HCN2 isoforms by immunoprecipitation and trypsin in-gel digestion, the samples were analyzed by mass spectrometry. We identified numerous phosphosites from HCN1 and HCN2 channels, representing a novel survey of phosphorylation sites within HCN channels. We found high levels of HCN channel phosphosite homology between humans and rats. We also identified a novel HCN1 channel phosphosite S791, which underwent significantly increased phosphorylation during the chronic epilepsy stage. Heterologous expression of a phosphomimetic mutant, S791D, replicated a hyperpolarizing shift in Ih gating seen in neurons from chronically epileptic rats. These results show that HCN1 channel phosphorylation is altered in epilepsy and may be of pathogenic importance.

Management of odonto-stomatological emergencies during the COVID-19 alarm state in dental clinics in the Autonomous Community of Madrid (CAM), Spain: An observational study.

BACKGROUND: Odontology practice has been severely compromised by the pandemic caused by COVID-19 and Spain is one of the countries with higher incidence. Our aim with this study is to find out the number of cases and type of odonto-stomatological emergencies (OSE) treated in four dental clinics of the Madrid capital area and region (CAM) in the period covered between March 17th and 4th of May. MATERIAL AND METHODS: We search the cases in the demographic/epidemiological databases of the CAM regional government and the Illustrious Official College of Dentists and Stomatologists of the First Region (Madrid). RESULTS: We found that the most prevalent pathology was acute apical periodontitis whereas odontogenic abscess showed the lowest frequency. Prosthetic-orthodontic OSE represented 14% of cases. CONCLUSIONS: In this period of time, the most prevalent pathology acute apical periodontitis, odontogenic abscess reported the lowest frequency and prosthetic-orthodontic treatments were the third in number of cases. Most of OSE were resolved, without referring the patient to a hospital emergency department.

Experimental exploration of dynamic phase transitions and associated metamagnetic fluctuations for materials with different Curie temperatures.

We study dynamic magnetic behavior in the vicinity of the dynamic phase transition (DPT) for a suitable series of samples that have different Curie temperatures T_{C}, which thus enables us to experimentally explore the role of the reduced temperature T/T_{C} in the DPT. For this purpose, we fabricate Co_{1-x}Ru_{x} epitaxial thin films with uniaxial in-plane anisotropy by means of sputter deposition in the concentration range 0.0≤x≤0.26. All samples are ferromagnetic at room temperature, exhibit an abrupt magnetization reversal along their easy axis, and represent a unique T_{C} and thus T/T_{C} ratio according to their Ru concentration. The dynamic magnetic behavior is measured by using an ultrasensitive transverse magneto-optical detection method and the resulting dynamic states are explored as a function of the applied magnetic field amplitude H_{0} and period P, as well as an additional bias field H_{b}, which is the conjugate field of the dynamic order parameter Q. Our experimental results demonstrate that the qualitative behavior of the dynamic phase diagram is independent of the T/T_{C} ratio and that for all T/T_{C} values we observe metamagnetic anomalies in the dynamic paramagnetic state, which do not exist in the corresponding thermodynamic phase diagram. However, quantitatively, these metamagnetic anomalies are very strongly dependent on the T/T_{C} ratio, leading to an about 20-fold increase of large metamagnetic fluctuations in the paramagnetic regime as the T/T_{C} ratio increases from 0.37 to 0.68. Also, the phase space range in which these anomalous metamagnetic fluctuations occur extends closer and closer to the critical point as T/T_{C} increases.

Publisher Correction: Feasibility and effects of enhanced recovery vs. conventional care after emergency colon surgery for patients with left colon perforation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Feasibility and effects of enhanced recovery vs. conventional care after emergency colon surgery for patients with left colon perforation.

The impact of an enhanced recovery after surgery (ERAS) programme in emergency colorectal surgery has not yet been reported. The objective of this study was to evaluate the feasibility and the results of patients included in an ERAS protocol following emergency colon surgery for left colon perforation. For this purpose, patients with a low to moderate risk of mortality, according to a Peritonitis Severity Score (PSS), and treated with an ERAS protocol (ERAS group) after emergency surgery for left colon perforation were compared for a period of 40 months (March 2014-June 2017) with a control group of patients treated with conventional care (CC group) during the 38 months prior to implementation of the new ERAS protocol (January 2011-February 2014). The main endpoint was 90-day postoperative morbidity according to the Clavien-Dindo classification. Secondary endpoints included length of postoperative hospital stay, 90-day readmission rate, protocol compliance and mortality. Fifty patients were included in the study, 29 in the ERAS group and 21 in the CC group. There were no significant differences between the groups in the demographic data or in the operative characteristics. A reduction in the incidence of postoperative complications (20.7% vs. 38%; p > 0.05) and in the postoperative hospital stay (7.7 + /- 3.85 vs. 10.9 + /- 5.6 days; p = 0.009) were observed in the ERAS group. The 90-day readmission rate did not differ significantly between the two groups (2 vs. 1). No 90-day mortality was observed in either group. The ERAS group showed better results than the CC group in protocol compliance. We conclude that ERAS protocols are feasible and help to reduce morbidity and length of hospital stay without adversely affecting the rate of readmission or mortality.

Postoperative Outcomes Within an Enhanced Recovery after surgery protocol in gastric surgery for cancer (POWER.4): Study protocol for a prospective, multicentre, observational cohort study. / Auditoría nacional de complicaciones después de la cirugía gástrica por cáncer dentro o no de un protocolo de recuperación intensificada (POWER.4): Protocolo de un estudio prospectivo, multicéntrico, observacional de cohortes.

BACKGROUND AND OBJECTIVE: Enhanced recovery pathways or ERAS have been applied in gastric cancer surgery extrapolated from colorectal surgery. The objective of the study is to assess postoperative complications 30 days after gastric surgery for cancer, with any level of compliance with the ERAS protocol. The secondary objectives are to assess 30-day mortality, the relationship between adherence to the ERAS protocol and complications, the impact of each of the items of the protocol on postoperative complications and hospital stay, and to describe the impact of complications on length of hospital stay. MATERIALS AND METHODS: Multicenter, observational, prospective study including all consecutive patients undergoing scheduled gastric cancer surgery, over a period of 3 months, with a 30-day follow-up at participating centers, with any level of compliance with the protocol. RESULTS: The approval of the Comité Autonómico de Ética de la Investigación de Aragón has been obtained (C.P. - C.I. PI19 / 106, 27 th March 2019). POWER.4 was registered at www.clinicaltrials.gov on March 7, 2019 (NCT03865810). CONCLUSIONS: The data as a whole will be published in peer-reviewed journals. The data will not be made public by identifying each participating center. It is expected that the results of this study will identify potential areas for improvement in which more targeted research is needed.

SHOX Duplication and Tall Stature in a Patient with Xq Deletion and Vascular Disease.

The anomalies of X chromosome are classified as numerical or structural. Concomitant structural anomalies in this chromosome that associate partial loss of its long arm with duplications in its short arm are uncommon. Only a few cases have been published and in most of them the reported patients present ovarian dysfunction, tall stature, and overdosage of the SHOX gene with locus Xp22.33. Considering these reports, we evaluated the case of a woman with a deletion in the long arm of the X chromosome, premature ovarian failure, tall stature, and multiple arterial vascular disease. With the aim to find a relationship between karyotype and phenotype, we explored associated anomalies in Xp and certified the overdosage of the SHOX gene in this case by MLPA. Also, taking into account the fact that the gene locus of the angiotensin-converting enzyme type 2 (ACE2) is located in Xp, our goal was to investigate the influence of this gene in the development of cardiovascular disease. The detection of the gene product of ACE2 by ELISA was undetectable. We have proposed that cytogenetic anomalies in X chromosome could contribute to decrease this protein synthesis in this gender.

Ultra-wideband Ge-rich silicon germanium mid-infrared polarization rotator with mode hybridization flattening.

In this work we investigate the implementation of ultra-wideband polarization rotator in the mid-infrared spectral region. A new design method of the rotation section is proposed, yielding a polarization rotator with an extinction ratio of at least 15 dB in a wavelength range of 2 µm. For a spectral range wider than 3.8 µm, an extinction ratio of at least 10 dB is achieved for this design. The device is 1660 µm long and the associated insertion loss is below 1.2 dB on the full operational wavelength range. The influence of geometrical parameters with respect to the design method to obtain such a broadband behavior is discussed. Finally, to increase the tolerance to fabrication errors, a tapered rotator design is proposed. Such a device can support up to ± 100 nm fabrication errors and still guarantees remarkable broadband behavior. To the best of our knowledge, this is the first time an integrated polarization rotator is designed to operate for the wavelength range of 4 to 9 µm with a bandwidth exceeding 2 µm.

Isoflurane disrupts excitatory neurotransmitter dynamics via inhibition of mitochondrial complex I.

BACKGROUND: The mechanisms of action of volatile anaesthetics are unclear. Volatile anaesthetics selectively inhibit complex I in the mitochondrial respiratory chain. Mice in which the mitochondrial complex I subunit NDUFS4 is knocked out [Ndufs4(KO)] either globally or in glutamatergic neurons are hypersensitive to volatile anaesthetics. The volatile anaesthetic isoflurane selectively decreases the frequency of spontaneous excitatory events in hippocampal slices from Ndufs4(KO) mice. METHODS: Complex I inhibition by isoflurane was assessed with a Clark electrode. Synaptic function was measured by stimulating Schaffer collateral fibres and recording field potentials in the hippocampus CA1 region. RESULTS: Isoflurane specifically inhibits complex I dependent respiration at lower concentrations in mitochondria from Ndufs4(KO) than from wild-type mice. In hippocampal slices, after high frequency stimulation to increase energetic demand, short-term synaptic potentiation is less in KO compared with wild-type mice. After high frequency stimulation, both Ndufs4(KO) and wild-type hippocampal slices exhibit striking synaptic depression in isoflurane at twice the 50% effective concentrations (EC50). The pattern of synaptic depression by isoflurane indicates a failure in synaptic vesicle recycling. Application of a selective A1 adenosine receptor antagonist partially eliminates isoflurane-induced short-term depression in both wild-type and Ndufs4(KO) slices, implicating an additional mitochondria-dependent effect on exocytosis. When mitochondria are the sole energy source, isoflurane completely eliminates synaptic output in both mutant and wild-type mice at twice the (EC50) for anaesthesia. CONCLUSIONS: Volatile anaesthetics directly inhibit mitochondrial complex I as a primary target, limiting synaptic ATP production, and excitatory vesicle endocytosis and exocytosis.

Memristive behaviour of Si-Al oxynitride thin films: the role of oxygen and nitrogen vacancies in the electroforming process.

The resistive switching properties of silicon-aluminium oxynitride (SiAlON) based devices have been studied. Electrical transport mechanisms in both resistance states were determined, exhibiting an ohmic behaviour at low resistance and a defect-related Poole-Frenkel mechanism at high resistance. Nevertheless, some features of the Al top-electrode are generated during the initial electroforming, suggesting some material modifications. An in-depth microscopic study at the nanoscale has been performed after the electroforming process, by acquiring scanning electron microscopy and transmission electron microscopy images. The direct observation of the devices confirmed features on the top electrode with bubble-like appearance, as well as some precipitates within the SiAlON. Chemical analysis by electron energy loss spectroscopy has demonstrated that there is an out-diffusion of oxygen and nitrogen ions from the SiAlON layer towards the electrode, thus forming silicon-rich paths within the dielectric layer and indicating vacancy change to be the main mechanism in the resistive switching.

Graded SiGe waveguides with broadband low-loss propagation in the mid infrared.

Mid-infrared (mid-IR) silicon photonics is expected to lead key advances in different areas including spectroscopy, remote sensing, nonlinear optics or free-space communications, among others. Still, the inherent limitations of the silicon-on-insulator (SOI) technology, namely the early mid-IR absorption of silicon oxide and silicon at λ~3.6 µm and at λ ~8.5 µm respectively, remain the main stumbling blocks that prevent this platform to fully exploit the mid-IR spectrum (λ ~2-20 µm). Here, we propose using a compact Ge-rich graded-index Si1-xGex platform to overcome this constraint. A flat propagation loss characteristic as low as 2-3 dB/cm over a wavelength span from λ = 5.5 µm to 8.5 µm is demonstrated in Ge-rich Si1-xGex waveguides of only 6 µm thick. The comparison of three different waveguides design with different vertical index profiles demonstrates the benefit of reducing the fraction of the guided mode that overlaps with the Si substrate to obtain such flat low loss behavior. Such Ge-rich Si1-xGex platforms may open the route towards the implementation of mid-IR photonic integrated circuits with low-loss beyond the Si multi-phonon absorption band onset, hence truly exploiting the full Ge transparency window up to λ ~15 µm.

Facts and challenges in respiratory neurobiology.

Respiratory neurobiology has been a lead discipline in the field of neuroscience for almost a century. Despite this, research studies on the fundamental synaptic and cellular processes underlying the generation and modulation of breathing movements suffered a significant decline during the last decade. We still believe that respiratory neurobiology is one of the most exciting and imperative fields of neuroscience. With the first white paper concerned with the central control of breathing, we want to celebrate the global importance of breathing research.

[Situs inversus of the optic nerve. A case report]. / Situs inversus del nervio optico. A proposito de un caso.

INTRODUCTION: Situs inversus of the optic nerve is a congenital anomaly characterised by the emergence of the vessels in the retina towards the nose rather than in a temporal direction. It is caused by an anomalous insertion of the optic stalks into the optic vesicle that gives rise to dysversion of the head of the optic nerve. It is not an isolated condition and usually appears jointly with tilted disc syndrome and in patients with myopia. It is characterised by the presence of inferior conus atrophy, deficiencies in the temporal visual field, refraction defects and ambliopy. CASE REPORT: A 22 years-old female who attended an ophthalmological examination due to severe frontal headaches accompanied by halos and loss of sharpness in her sight. From the results of the ophthalmetric and ophthalmological examination she was diagnosed as suffering from a condition consistent with this congenital anatomical anomaly. CONCLUSIONS: Situs inversus of the optic nerve is a rare condition that may appear in isolation or accompanied by other pathologies. Application of the visual field test and new diagnostic techniques, such as optical coherence tomography, facilitates the differential diagnosis of this situation. Its prevalence remains unknown, as it is not included in the register of rare diseases. Moreover, the scant number of patients studied and the scarce literature on this anomaly do not allow us to know whether the defects it causes develop over time. It would therefore be important to perform an ophthalmological follow-up of patients with situs inversus of the optic nerve.

TITLE: Situs inversus del nervio optico. A proposito de un caso.Introduccion. El situs inversus del nervio optico es una anomalia congenita caracterizada por la emergencia de los vasos de la retina en direccion nasal en lugar de temporal. Es causado por una anomala insercion del tallo optico en la vesicula optica que da lugar a la variacion de disposicion de la cabeza del nervio optico. No es una condicion aislada y suele aparecer junto con el sindrome del disco inclinado y en pacientes con miopia. Se caracteriza por la presencia de un cono de atrofia inferior, defectos en el campo visual temporal, defectos de refraccion y ambliopia. Caso clinico. Mujer de 22 años, que acude a revision oftalmologica por presentar fuertes cefaleas frontales acompañadas de halos y perdida de nitidez en la vision. Tras un examen optometrico y oftalmologico se llega al juicio clinico de que padece un cuadro compatible con esta anomalia anatomica congenita. Conclusiones. El situs inversus del nervio optico es una condicion rara que puede aparecer aislada o acompañada de otras patologias. La aplicacion de la campimetria y de nuevas tecnicas diagnosticas, como la tomografia de coherencia optica, facilita el diagnostico diferencial de esta situacion. No se conoce su prevalencia, pues no se encuentra en el registro de las enfermedades raras. Ademas, el escaso numero de pacientes estudiados y la exigua bibliografia existente sobre esta anomalia no permiten conocer si los defectos causados progresan en el tiempo, por lo que seria importante realizar un seguimiento oftalmologico de los pacientes con situs inversus del nervio optico.

Ge-rich graded-index Si1-xGex waveguides with broadband tight mode confinement and flat anomalous dispersion for nonlinear mid-infrared photonics.

This work explores the use of Ge-rich graded-index Si1-xGex rib waveguides as building blocks to develop integrated nonlinear optical devices for broadband operation in the mid-IR. The vertical Ge gradient concentration in the waveguide core renders unique properties to the guided optical mode, providing tight mode confinement over a broadband mid-IR wavelength range from λ = 3 µm to 8 µm. Additionally, the gradual vertical confinement pulls the optical mode upwards in the waveguide core, overlapping with the Ge-rich area where the nonlinear refractive index is larger. Moreover, the Ge-rich graded-index Si1-xGex waveguides allow efficient tailoring of the chromatic dispersion curves, achieving flat anomalous dispersion for the quasi-TM optical mode with D ≤ 14 ps/nm/km over a ~1.4 octave span while retaining an optimum third-order nonlinear parameter, γeff. These results confirm the potential of Ge-rich graded-index Si1-xGex waveguides as an attractive platform to develop mid-IR nonlinear approaches requiring broadband dispersion engineering.