Metagenomic analyses highlight the symbiotic association between the glacier stonefly Andiperla willinki and its bacterial gut community.

The glacier stonefly Andiperla willinki is the largest metazoan inhabiting the Patagonian glaciers. In this study, we analysed the gut microbiome of the aquatic nymphs by 16S rRNA gene amplicon and metagenomic sequencing. The bacterial gut community was consistently dominated by taxa typical of animal digestive tracts, such as Dysgonomonadaceae and Lachnospiraceae, as well as those generally indigenous to glacier environments, such as Polaromonas. Interestingly, the dominant Polaromonas phylotypes detected in the stonefly gut were almost never detected in the glacier surface habitat. Fluorescence in situ hybridization analysis revealed that the bacterial lineages typical of animal guts colonized the gut wall in a co-aggregated form, while Polaromonas cells were not included in the aggregates. Draft genomes of several dominant bacterial lineages were reconstructed from metagenomic datasets and indicated that the predominant Dysgonomonadaceae bacterium is capable of degrading various polysaccharides derived from host-ingested food, such as algae, and that other dominant bacterial lineages ferment saccharides liberated by the polysaccharide degradation. Our results suggest that the gut bacteria-host association in the glacier stonefly contributes to host nutrition as well as material cycles in the glacier environment.

Late recurrence of myopic foveoschisis after successful repair with primary vitrectomy and incomplete membrane peeling.

PURPOSE: To report three cases of late recurrence of myopic foveoschisis (MF) after initial successful repair with pars plana vitrectomy and membrane peeling to assess the importance of internal limiting membrane peeling. METHODS: A retrospective noncomparative case series was performed of patients who underwent a primary pars plana vitrectomy by a single surgeon with successful resolution of MF, but eventually underwent repeat pars plana vitrectomy for recurrent MF. Best-corrected visual acuity, fundus photography, and optical coherence tomography were obtained at each examination. RESULTS: Three eyes of three patients underwent pars plana vitrectomy for recurrent MF. Myopic foveoschisis recurrence occurred 6, 3.5, and 12 years after the primary vitrectomy, respectively. Repeat vitrectomy with staining and additional peeling of the internal limiting membrane resulted in good anatomical outcome and stabilization of visual acuity in all cases. CONCLUSION: Late recurrence of MF after successful primary vitrectomy is described. Fibrocellular proliferation on residual cortical vitreous or incomplete internal limiting membrane peeling during the initial vitrectomy may underlie recurrence.

Residual internal limiting membrane after epiretinal membrane peeling: results of the Pan-American Collaborative Retina Study Group.

PURPOSE: To determine the degree of residual internal limiting membrane (ILM) after idiopathic epiretinal membrane (ERM) peeling and the usefulness of staining with brilliant blue G. METHODS: A prospective, multicenter, observational study of 98 eyes undergoing pars plana vitrectomy and membrane peeling for idiopathic ERM. All eyes underwent core vitrectomy (20, 23, or 25 gauge) followed by intravitreal triamcinolone to verify that the posterior hyaloid had been removed. Brilliant blue G (0.2 mL of 0.25 mg/mL) was injected into the vitreous cavity and washed out immediately. The ERM was peeled and then the surgeon observed and recorded the characteristics of the underlying ILM. The posterior pole was restained with brilliant blue G (0.2 mL of 0.25 mg/mL), and the same observations on the characteristics of the ILM were recorded. Peeling of the remaining ILM was performed. The main outcome measured was the status of the ILM after ERM peel. Secondary outcomes included best-corrected visual acuity and central macular thickness at 6 months postoperatively. RESULTS: After ERM peel, all of the eyes had residual ILM. In 74 eyes, the ILM was present and damaged, whereas in 24 eyes, the ILM was present and undamaged. In 37 eyes, the operating surgeon was unable to determine the status of the ILM before brilliant blue G staining. At 6 months, the logarithm of the minimum angle of resolution best-corrected visual acuity improved from 0.75 ± 0.39 at baseline to 0.31 ± 0.26 (P < 0.0001). The central macular thickness also improved from 460 ± 91 µm at baseline to 297 ± 102 µm (P < 0.003). CONCLUSION: Internal limiting membrane is frequently still present after ERM peeling. Staining with brilliant blue G facilitates its identification.

Smoke health costs and the calculus for wildfires fuel management: a modelling study.

BACKGROUND: Smoke from uncontrolled wildfires and deliberately set prescribed burns has the potential to produce substantial population exposure to fine particulate matter (PM2·5). We aimed to estimate historical health costs attributable to smoke-related PM2·5 from all landscape fires combined, and the relative contributions from wildfires and prescribed burns, in New South Wales, Australia. METHODS: We quantified PM2·5 from all landscape fire smoke (LFS) and estimated the attributable health burden and daily health costs between July 1, 2000, and June 30, 2020, for all of New South Wales and by smaller geographical regions. We combined these results with a spatial database of landscape fires to estimate the relative total and per hectare health costs attributable to PM2·5 from wildfire smoke (WFS) and prescribed burning smoke (PBS). FINDINGS: We estimated health costs of AU$ 2013 million (95% CI 718-3354; calculated with the 2018 value of the AU$). $1653 million (82·1%) of costs were attributable to WFS and $361 million (17·9%) to PBS. The per hectare health cost was of $105 for all LFS days ($104 for WFS and $477 for PBS). In sensitivity analyses, the per hectare costs associated with PBS was consistently higher than for WFS under a range of different scenarios. INTERPRETATION: WFS and PBS produce substantial health costs. Total health costs are higher for WFS, but per hectare costs are higher for PBS. This should be considered when assessing the trade-offs between prescribed burns and wildfires. FUNDING: None.

Central Microscotoma: A Rare Presentation of Epiretinal Membranes.

BACKGROUND AND OBJECTIVE: Patients with a symptomatic epiretinal membrane (ERM) typically complain of metamorphopsia and decreased visual acuity. We describe three patients who presented with the single complaint of a central microscotoma due to ERM, an infrequent initial symptom of this entity. PATIENTS AND METHODS: This is a retrospective, interventional, non-comparative case series. Three patients with the chief complaint of a central microscotoma related to ERMs who underwent pars plana vitrectomy by a single surgeon experienced full resolution of the preoperative microscotoma. Best-corrected visual acuity, fundus photography, and optical coherence tomography were obtained at each examination. A comprehensive neuro-ophthalmologic evaluation was performed in all cases, including magnetic resonance imaging of the orbits and brain, automated visual fields, multifocal electroretinography, multifocal visually evoked potentials, and blood tests. RESULTS: Three eyes of three patients who presented with the initial sole complaint of a central microscotoma due to ERM are included in this series. A comprehensive neuro-ophthalmologic evaluation ruled out non-retinal etiologies. After months of observation, a pars plana vitrectomy with ERM and internal limiting membrane peeling was performed in all patients. Postoperatively, the patients experienced a complete resolution of their initial, isolated complaint of a central microscotoma. CONCLUSION: Central microscotoma, as a rare stand-alone presentation of ERM, is described. This symptom resolved after a successful removal of the ERM. A greater awareness among clinicians that ERMs may present in this manner may help avoid excessive and costly medical evaluations.

[Natural history of diabetic retinopathy in a retrospective cohort of type 1 diabetics]. / Historia natural de retinopatía diabética en un estudio a largo plazo en pacientes con diabetes tipo 1. Factores de riesgo para progresión a enfermedad proliferante.

BACKGROUND: Diabetic retinopathy is one of the most common causes of blindness among adults. AIM: To report the natural history of diabetic retinopathy among Chilean patients with type 1 diabetes followed for a mean of 18 years. MATERIAL AND METHODS: Retrospective review of medical records of 39 patients aged 26 to 70 years, (20 females, 78 eyes) with type 1 diabetes controlled by the same ophthalmologist from 1971 to 2008. A questionnaire was sent to each patient and their treating physician to request information about the evolution of the disease and metabolic control. RESULTS: The questionnaire was answered by 24 patients (62%) and 21 attending physicians (54%). Small hard drusen were observed in 25 patients (64%). In 12 cases the drusen were detected before the development of any type of retinopathy. Eleven women became pregnant and retinopathy progressed in four of them. Twenty three patients (59%) developed proliferative diabetic retinopathy (PDR). Patients with PDR had a significantly longer duration of diabetes and worse glycemic control. There was a higher frequency of diabetic nephropathy in the PDR group, but only 13 patients out of 23 with PDR had nephropathy. The retinopathy progressed to high risk PDR two years after successful kidney-pancreas transplantation in one patient. CONCLUSIONS: In patients with type 1 diabetes mellitus, small hard drusen may be the initial manifestation of diabetic retinopathy. Risk factors for progression to PDR were duration of diabetic and poor glycemic control. Nephropathy was more prevalent in patients with PDR, but a significant group of PDR patients did not have demonstrable nephropathy.

Historia natural de retinopatía diabética en un estudio a largo plazo en pacientes con diabetes tipo 1. Factores de riesgo para progresión a enfermedad proliferante / Natural history of diabetic retinopathy in a retrospective cohort of type 1 diabetics

Background: Diabetic retinopathy is one of the most common causes of blindness among adults. Aim: To report the natural history of diabetic retinopathy among Chilean patients with type 1 diabetes followed for a mean of 18 years. Material and methods: Retrospective review of medical records of 39 patients aged 26 to 70 years, (20 females, 78 eyes) with type 1 diabetes controlled by the same ophthalmologist from 1971 to 2008. A questionnaire was sent to each patient and their treating physician to request information about the evolution of the disease and metabolic control. Results: The questionnaire was answered by 24 patients (62 percent) and 21 attending physicians (54 percent). Small hard drusen were observed in 25 patients (64 percent). In 12 cases the drusen were detected before the development of any type of retinopathy. Eleven women became pregnant and retinopathy progressed in four of them. Twently three patients (59 percent) developed proliferative diabetic retinopathy (PDR). Patients with PDR had a significantly longer duration of diabetes and worse glycemic control. There was a higher frequency of diabetic nephropathy in the PDR group, but only 13 patients out of 23 with PDR had nephropathy. The retinopathy progressed to high risk PDR two years after successful kidney-pancreas transplantation in one patient. Conclusions. In patients with type 1 diabetes mellitus, small hard drusen may be the initial manifestation of diabetic retinopathy. Risk factors for progression to PDR were duration of diabetic and poor glycemic control. Nephropathy was more prevalent in patients with PDR, but a significant group of PDR patients did not have demonstrable nephropathy (RevMéd Chile 2009; 137:1145-52).

[Hypercoagulability in atrial fibrillation and its relationship with risk factors for systemic embolism]. / Hipercoagulabilidad en fibrilación auricular y su relación con factores de riesgo para embolia sistémica.

BACKGROUND: Atrial fibrillation is associated to a high risk of systemic embolism and to hypercoagulability. AIM: To evaluate the activation of the coagulation cascade through determinations of the thrombin-antithrombin complex in patients with atrial fibrillation and to correlate this data with the clinical and echocardiographic risk factors for systemic embolism. PATIENTS AND METHODS: In 53 patients with atrial fibrillation plasma levels of the thrombin-antithrombin complex were determined on admission to a coronary care unit and 30 days later. Using a univariate and multiple regression analysis, the association basal thrombin-antithrombin with the duration of the arrhythmia, age over 70 years, previous use of antiplatelet agents, history of hypertension, mitral valve disease, diabetes, heart failure, previous systemic embolism, left atrial diameter and the presence of spontaneous contrast echo or thrombus in the left atrial appendage, was studied. RESULTS: Basal thrombin-antithrombin values were 40.1 +/- 69 mg/L (Median 8.34 [3.0-47.5]) compared to 2.7 +/- 3.3 mg/L in healthy controls (p < 0.001). No significant correlation was found between activation of the coagulation cascade and risk factors for systemic embolism. There were no significant differences in thrombin-antithrombin values between patients with chronic or paroxysmal atrial fibrillation (29.5 +/- 43 mg/L and 49.4 +/- 83 mg/L respectively). Mean thrombin-antithrombin values in patients under antiplatelet agents were lower than in those without treatment (17.3 +/- 43 vs 66.8 +/- 127 mg/L; p = 0.018). CONCLUSIONS: The activation of the coagulation cascade in patients with atrial fibrillation was confirmed. However, no association of this activation with well known clinical and echocardiographic risk factors for systemic embolism, was found. Previous antiplatelet treatment prevented a higher activation of the coagulation cascade.

Angina variante asociada al uso de un descongestionante nasal / Varying angina associated to the use of a nasal anticongestive agent

Se comunica la observación de un paciente que hace episodios de angina variante con taquicardia ventricular polimorfa, en relación a inhalación de nafazolina, como descongestionante nasal. Este caso plantea la eventualidad de que un medicamento de uso corriente, como estos preparados de pretendida acción local, pueda desencadenar arritmias severas, consecutivo a un espasmo coronario en individuos susceptibles, particularmente si presentan lesiones coronarias, por discretas que éstas sean

Anulación de imagen electrocardiográfica de necrosis anterior por un infarto inferior / Disappearance of the EGG image of anterior wall myocardial infarction after an inferior wall myocardial infarction

Se presenta el caso de un paciente con infarto del miocardio de pared anterior cuyas alteraciones electrocardiográficas son anuladas al sobrevenir un nuevo proceso en pared diafragmática. La observación constituye un hecho inhabitual cuya posibilidad debe plantearse como fuente de error en la interpretación del electrocardiograma para caracterizar la existencia, ubicación, extensión y evolución del infarto. Además por representar un fenómeno de cancelación de magnitudes vectoriales divergentes, da apoyo al concepto de dipolo en la generación de las imágenes electrocardiográficas obtenidas en los registros de superficie

Parasistolía ventricular modulada: un mecanismo inédito de síndrome de bradi-taquicardia

Se describe un caso de síndrome de bradi-taquicardia en una paciente de 66 años, quien en el curso de un infarto agudo del miocardio presenta períodos de disociación AV, por taquicardia ventricular intermitente y bradicardia sinusal. En los intervalos, entre los brotes de taquicardia, aparecen complejos ectópicos aislados, morfológicamnte similares a los del ritmo ectópico mantenido, sugiriendo bloqueo de salida de un foco parasistólico modulado. Esta posibilidad plantea un mecanismo inusual de bradicardia que se hace plausible en un terreno de cardiopatía coronaria

Bloqueo AV tipo Wenckebach y bloqueo de ramas variable en infarto agudo del miocardio / Wenchebach and bundle branch block in acute myocardial infarction

Se presenta un caso clínico de infarto agudo del miocardio de pared inferior en quien se detectó concomitancia de bloqueo A-V tipo Wenckebach y bloqueo de ramas variable. Los diversos mecanismos que pueden explicar esta coincidencia sugieren compromiso difuso del sistema de éxito-conducción, funcional y transitorio, pero traducen la gravedad y extensión del daño miocárdico isquéemico. De allí la importancia pronóstica del hallazgo, pese a su rareza

Infarto de cara diafragmática y ventrículo derecho con ruptura septal: implicancias pronósticas de la disfunción ventricular derecha / Right ventricular infarction and septal rupture: pronostic implications of the right ventricular disfunction

Se analizan los rasgos clínicos y anatomopatológicos de una mujer de 66 años, hipertensa, diabética, dislipidémica y tabáquica, que a raíz de un primer infarto de cara diafragmática, se complica de infarto del ventrículo derecho, con severa disfunción, y ruptura del septum interventricular. Pese a la reparación quirúrgica de urgencia, se produjo el desenlace fatal, lo que se atribuye principalmente a la grave disfunción ventricular derecha. En la discusión se enfatiza el rol pronóstico que juega ésta en presencia de ruptura septal en el curso de un infarto reciente del miocardio

Infarto agudo de miocardio tipo Q con recuperación funcional del área de necrosis: implicancias fisiopatológicas y terapeúticas / Q Wave acute myocardial infarction with funcional recovery of necrotic area: physiopathologic and therapeutic implications: case report

Se presenta el caso de una paciente que desarrolla un cuadro clínico de Infarto agudo de miocardio con evidencias de necrosis miocárdica según criterio eco, electro y ventriculográficos en la pared anterior del ventrículo izquierdo. La angiografía coronaria muestra una lesión de 95% en el tercio proximal de arteria descendente anterior. A los 90 días de evolución vuelve a tener episodios de angina de pecho encontrándose que han desaparecido los signos de necrosis en eco y electrocardiograma habiéndose normalizado, además el patrón de contracción segmentario del ventrículo izquierdo. Se discuten la relatividad de los criterios diagnósticos para establecer necrosis miocárdica

Protección radiológica en instalaciones de radiodiagnóstico: un estudio de resultados en la rutina clínica / Radiologic protection in radiodiagnostic installations: study on clinical routine results

Se midió la tasa de exposición (mR/hora) en un promedio de 10 posiciones relevantes con un criterio de protección radiológica, en un total de 17 instalaciones de radiodiagnóstico (radiología osteoarticular, tomografía computada, mamografía, radiología digestiva y dental) de la red de centros médicos de OMESA y Clínica Santa María. Se calcularon las dosis acumuladas en un período de 1 semana, en condiciones de rutina clínica y operacionalmente conservadoras, y se comprobó que todas ellas son muy inferiores a los máximos permisibles y hacen innecesario el uso de barreras secundarias. La muestra es representativa de instalaciones similares en nuestro medio, lo cual permite extrapolar estos resultados a otras instalaciones