Perceived sources of stress amongst Chilean and Argentinean dental students.

INTRODUCTION: The prevalence of high levels of stress as well as its multilevel consequences is well documented amongst students in the health sciences, and particularly in dentistry. However, investigations of perceived stress amongst Spanish-speaking student groups are sparse. This study aimed to (i) describe the translation, adaptation and psychometric properties of a Spanish version of the Dental Environment Stressors questionnaire and (ii) to examine the perceived sources of stress and their associations with the students' study year and gender in two dental schools in Latin America. MATERIALS AND METHODS: All students officially registered in the dental schools of the University of San Sebastian (USS) in Chile and the Catholic University of Cordoba (CUC) in Argentina were invited to participate in the study. The DES30 questionnaire was adapted in Spanish using translation/back-translation, an expert bilingual committee, and consensus building. Cronbach's alpha was used to measure the instrument's internal consistency, and iterated principal factor analysis with promax rotation was employed to explore its underlying factor structure. Descriptive, bivariate and multivariate methods were used to examine the patterns of association between individual stressors, factor scores and students' characteristics. RESULTS: Three hundred and four students comprised the study's analytical sample, with two-thirds of those being female. The DES30-Sp demonstrated good internal consistency (Cronbach's α = 0.89). A four-factor solution emerged and included 'academic workload', 'clinical training', 'time constraints' and 'self-efficacy beliefs' factors. 'Fear of failing a course or a year', 'examinations and grades' and 'lack of time for relaxation' were amongst the top individual-item stressors reported by students in both schools. Amongst this group of undergraduate dental students, those in Argentina, in higher study year, and females reported higher perceived stress. CONCLUSIONS: Increased workload, time constraints and some aspects of clinical training were the top stressors of approximately 300 Chilean and Argentinean dental undergraduates. Some variations between schools, males and females and study years were noted. The Spanish version of the DES30 questionnaire performed well, but future studies should evaluate the instrument's properties in larger and more diverse dental student populations.

Anticancer activity of two novel ruthenium compounds in gastric cancer cells.

AIMS: Ruthenium (II) complexes are promising anticancer molecules due its pharmacological properties and selectivity to cells tumor. The aim of this work was to study the cytotoxic activity, and apoptosis induction of two new ruthenium complexes on a human gastric cancer cell line. MAIN METHODS: Two ruthenium(II) complexes were synthesized: [(H2pbbzim)Ru(tpy-Ph-COOCH3)](Cl)2 (Ru-UCN1), and [(tpy)Ru(tpy-Ph-bzH)](Cl)2 (Ru-UCN3), and their anticancer capacity determined by cytotoxic assays, gene expression analysis, caspase activation and confocal microscopy. KEY FINDINGS: Ru-UCN3 is more notably cytotoxic than cisplatin in human gastric cancer cells AGS at 24 h, while Ru-UCN1 is more active against gastric cancer cells than cisplatin at 48 h. The complexes induce apoptosis as shown by RT-qPCR, protease activity, and confocal microscopy. Ru-UCN1 induces the overexpression of pro-apoptotic genes at 3 and 6 h, whereas Ru-UCN3 induces overexpression of these genes at 12 and 24 h. Ru-UCN1 treatment shows a strong activation of caspases 3/7 at 24 h, which was not observed for Ru-UCN3 treatment in the same timeframe. SIGNIFICANCE: Taken together, this data suggests that Ru-UCN1 and to a lesser extent, Ru-UCN3, may be interesting anticancer agents for gastric cancer.

Estudio retrospectivo. Influencia de la Terapia Kinesiológica Temprana en el uso de Casco Modelador Craneal / Retrospective study. Influence of early physical therapy on the need to wear a skull molding helmet

Introducción. La plagiocefalia no sinostósica es una condición de salud caracterizada por una asimetría de cráneo que tiene diversas consecuencias en el desarrollo. Los principales tratamientos son la kinesioterapia y el casco de moldeado craneal (CMC). Objetivo. Evidenciar la influencia de la kinesioterapia temprana en la necesidad de usar casco modelador craneal. Métodos. Se realizó un estudio cuantitativo, descriptivo y retrospectivo en lactantes mayores de tres meses ingresados al Centro de Rehabilitación Integral de Carabineros (CRICAR) con diagnóstico confirmado de plagiocefalia mediante la técnica de craneometría. Se recopilaron datos de 39 pacientes diagnosticados con plagiocefalia, evaluados y tratados entre 2017 y 2019. Se dividieron en dos grupos, ingreso temprano (bajo los 5,5 meses de edad cronológica) e ingreso tardío (sobre los 5,5 meses de edad cronológica). Resultados. Al realizar un análisis bivariado, se obtuvo que 9 de 20 pacientes tuvieron que usar CMC en el grupo de ingreso tardío, y solo 4 de 19 pacientes en el grupo de ingreso temprano. Al contrastar la razón de riesgo de usar CMC en el grupo expuesto versus el grupo no expuesto se obtiene que es 3 veces mayor, sin embargo, esta diferencia no es estadísticamente significativa (OR=3.06, IC95% 0.6-16.8) Conclusiones. El principal resultado de este estudio es la disminución en la diferencia de diagonales evaluadas con craneometría. Además, se ha observado que en nuestra muestra el uso de CMC es tres veces mayor cuando el ingreso a terapia kinesiológica es tardío.

Introduction. Non-synostotic plagiocephaly is health condition characterized by a skull asymmetry that has various developmental consequences. The main treatments are kinesiotherapy and cranial molding helmet (CMH). The purpose of this study is to evidence the influence of early kinesiotherapy on the need to use CMH. Methods. A quantitative, descriptive and retrospective study of infants older than three months, admitted to the Carabineros Comprehensive Rehabilitation Center (CRICAR) since January 2017 with a confirmed diagnosis of plagiocephaly by craniometry technique was performed. Data were collected from 39 patients diagnosed with plagiocephaly, evaluated and treated between 2017 and 2019. They were divided into two groups, early admission (under 5.5 months of chronological age) and late admission (over 5.5 months of chronological age). Results. When performing a bivariate analysis, we obtained that 9 out of 20 patients had to use CMC in the late admission group, and only 4 out of 19 patients had to use it in the opposite group. When contrasting the oods ratio of using CMC in the exposed group versus the non-exposed group we obtain that it is 3 times higher, however, this difference is not statistically significant (OR=3.06, IC95% 0.6-16.8). Conclusions. The main result of this study is the decrease in the difference in diagonals assessed with craniometry. In addition, it has been observed that in our sample the use of CMC is three times higher when admission to physical therapy is late.

Thrombin receptors: turning them off after turning them on.

Recent studies have helped to define the mechanisms by which thrombin activates platelets and other cells. Those studies show that the human thrombin receptor has a structure similar to other G protein-coupled receptors, but is activated by a novel mechanism in which thrombin cleaves its receptor, creating a new N-terminus that can serve as a tethered ligand. Shortly after activation, thrombin receptors become temporarily resistant to re-activation. Present evidence suggests that this loss of function is due to a combination of receptor desensitization, phosphorylation and internalization, and that recovery may involve dephosphorylation, as well as receptor recycling and the expression of newly-synthesized receptors. Together these processes provide a potent mechanism for limiting the duration of thrombin-initiated events in platelets and other thrombin-responsive vascular cells.

Cyclophosphamide pulse therapy in optic neuritis due to systemic lupus erythematosus: an open trial.

OBJECTIVE: To evaluate the efficacy of intravenous cyclophosphamide pulse therapy in patients with optic neuritis associated with systemic lupus erythematosus (SLE). PATIENTS AND METHODS: Ten consecutive patients with optic neuritis due to SLE whose condition was refractory to corticosteroids and oral immunosuppressants were treated with intravenous cyclophosphamide (0.5 to 1.0 g/m2) monthly for 6 months. RESULTS: All patients had bilateral eye involvement. One eye was legally blind, and 13 eyes could see only hand movements or count fingers. Six patients had evidence of the secondary antiphospholipid antibody syndrome. Complete recovery in visual acuity occurred in 10 eyes (50%), and a partial response occurred in six eyes (30%); four eyes (20%) had no response. Complete response in the field tests occurred in eight eyes (40%), with a partial response in nine eyes (45%); no improvement occurred in three eyes (15%). CONCLUSIONS: Intravenous cyclophosphamide pulse therapy seems to be an effective treatment for optic neuritis refractory to corticosteroids, oral immunosuppressants, or both. A randomized controlled trial will be necessary to confirm our results.

Spectroscopic study of the light-harvesting protein C-phycocyanin associated with colorless linker peptides.

C-Phycocyanin (PC) trimers associated with linker polypeptides were isolated from the phycobilisome (PBS) rods of Synechococcus sp. PCC 7002. LXY refers to a linker polypeptide (L) having an apparent mass of Y kDa, located at position X in the phycobilisome where X can be R (rod), C (core) or RC (rod-core junction). Measurements of the absorption, fluorescence and excitation anisotropy of PC trimer, PC.LR32.3 and PC.LRC28.5 complexes document the spectroscopic modulation of each linker polypeptide on the PC chromophores. The difference spectra between the PC trimer and the PC-linker complexes show that although the effect induced by the linker polypeptides is qualitatively similar in behavior, the extent of the modulation is greater in PC.LRC28.5. Measurements taken at 77 K show that a red-wavelength component of the PC trimer absorption-fluorescence spectra is the target of the linker's influence and that this component is altered to a greater extent by LRC28.5. In addition the 77 K absorbance of the PC trimer resolves band features that are consistent with an excitonic coupling interaction between neighboring alpha 84 and beta 84 chromophores. These band features are also evident in the absorbance of PC.LR32.3 but are absent in PC.LRC28.5 indicating that LRC28.5 may be perturbing the coupling interaction established in the PC trimer alpha 84-beta 84 chromophore pairs. Structurally, the linker polypeptide should disrupt the C3 symmetry in the central cavity of the associated phycobiliprotein and this asymmetric interaction should serve to guide the transfer of excitation energy along PBS rods toward the core elements.

Tru-cut needle biopsy of subcutaneous fat in the diagnosis of secondary amyloidosis in rheumatoid arthritis.

In order to investigate the presence of secondary amyloidosis in patients with rheumatoid arthritis (RA), we performed an abdominal subcutaneous fat biopsy with a tru-cut needle in 50 patients. The tissue was stained with Congo red and was observed with polarized light microscopy. We found amyloid deposits in 78% of our patients. We randomly selected ten patients with a positive biopsy and a second procedure was performed. Tissues were studied with electron microscopy. We found unbranched fibrils characteristic of amyloid in all of them. We found a direct correlation with rheumatoid factor titers: the more intense the amyloid deposit, the higher the rheumatoid factor titers (p < 0.001). We did not find any correlation between amyloid deposits and clinical manifestations of disease. Amyloid deposits in RA are more frequent than previously thought, and their clinical importance remains to be determined.

Malformación arterio venosa cervical compleja sintomática / Complex arteriovenous malformation of the neck

Background: Arteriovenous malformation (AVM) is an abnormal connection between arteries and veins, bypassing the capillary system and forming arterial, venous and capillary nests. Case report: We report a female consulting for the first time at the age of 15 for an AVM located in the left posterior region of the neck. The patient was operated at that time, performing an extensive excision of the lesion and covering the defect with a skin flap. The lesion relapsed three years later. Vascular imaging revealed the malformation with afferent arteries from the subclavian, vertebral and left occipital arteries and a great posterior cervical nest that drained through a great anomalous vein to the subclavian vein. A surgical ligation of all the anomalous branches of the subclavian vein was performed, to perform a local excision in a second intervention. The patient got pregnant, delaying the intervention and had a normal delivery at the age of 19. At 21 years of age, she consulted again due to a great growth of her AVM, with repeated bleeding episodes, requiring transfusions. The patient was treated with embolization of the nest and the afferent arteries. Finally at 23 years of age, the lesion was excised again and the defect was covered with a skin flap. The patient had a good postoperative evolution.

Introducción: Las Malformaciones Arterio-Venosas (MAV) son alteraciones estructurales congénitas del desarrollo del sistema vascular en que se observan comunicaciones anómalas arterio-venosas conformando un "nido" arterio-venoso-capilar. Caso Clínico: Mujer que consulta a los 15 años de edad por una MAV en la región cervical posterior izquierda desde su nacimiento. Se efectúa una resección amplia de la lesión hasta el plano aponeurótico cubriendo el defecto con un colgajo de rotación cutáneo-adiposo. Evoluciona bien, pero recidiva luego de tres años. Un estudio vascular a los 18 años de edad evidencia la MAV con arterias aferentes desde la arteria subclavia, vertebral y occipital izquierdas, un gran "nido" cervical posterior que drena por una gran vena anómala hacia la vena subclavia izquierda. Se efectúa una ligadura quirúrgica de todas las gruesas ramas anómalas de la arteria subclavia, para efectuar una nueva resección local en un segundo tiempo. Sin embargo, esto se pospone pues la paciente se embaraza y tiene un parto normal a los 19 años. Vuelve a consultar a los 21 años por un gran crecimiento de su MAV con hemorragias a repetición, algunas muy profusas que obligan a transfundirla. Una AngioRNM confirma la MAV con un gran nido cervical posterior con nuevas aferencias. Se efectúa embolizaciones directas locales con espuma de polidocanol y micropartículas, y finalmente con alcohol. Una vez reducido el nido se emboliza además las principales aferencias por vía endovascular y se efectúa a los 23 años una amplia resección de la MAV cubriendo el defecto con un colgajo miocutáneo de dorsal ancho izquierdo. Ha evolucionado bien hasta ahora. Conclusión: El diagnóstico y tratamiento de una MAV compleja representa un gran desafío al equipo médico tratante que acompaña y atiende al paciente en el transcurso del tiempo, y a veces por el resto de la vida.