Immunohistochemical Expression of PTEN in Canine Gliomas.

Phosphatase and tensin homolog (PTEN) is a critical tumor suppressor gene with a vital role in regulating cell proliferation, migration, and survival. The loss of PTEN function, either by genetic alterations or decreased protein expression, is frequent in human gliomas and has been correlated with tumor progression, grade, therapeutic resistance, and decreased overall survival in patients with glioma. While different genetic mutations in PTEN gene have been occasionally reported in canine gliomas, no alterations in protein expression have been reported. This study investigates the immunohistochemical expression of PTEN in canine gliomas to evaluate possible alterations, as those reported in human gliomas. Immunohistochemical PTEN expression and pattern distribution were analyzed in 37 spontaneous canine gliomas. Among gliomas, 52.6% cases showed high PTEN expression and 48.6% displayed reduced (13.5%) or highly reduced (35.1%) immunopositivity. Most oligodendrogliomas showed high expression (73.7%), while the majority of astrocytomas (69.2%) showed a reduced or highly reduced expression. A reduced PTEN expression was mostly associated with a heterogeneous loss of PTEN immunopositivity. These observations are in line with those reported in human gliomas and provide a rationale for future studies regarding abnormalities in PTEN expression and PI3K/Akt/mTor pathway in canine gliomas, to evaluate its prognostic and therapeutic implications.

Canine ovarian epithelial tumours: histopathological and immunohistochemical evaluation with proposed histopathological classification system.

Canine ovarian epithelial tumours (OETs) are currently divided into ovarian adenomas and carcinomas, which are further inconsistently subclassified as papillary or cystic, whereas in human medicine, OETs are subdivided into several subtypes. This study aimed to establish clear morphological features enabling more consistent distinction between benign OETs and ovarian carcinomas (OvCas) as well as defining different histopathological patterns of canine OvCas. Analysis revealed a mitotic count threshold of >2 as a potential criterion for differentiating OvCas from benign OETs. Alongside ovarian adenomas, ovarian borderline tumours were introduced as a distinct category among benign OETs. OvCas exhibited five different histopathological patterns, namely papillary, solid with tubular differentiation, micropapillary, cystic and sarcomatous. Since some OvCas can morphologically overlap with other ovarian tumours, the expression of cytokeratin 7, a cytokeratin expressed in ovarian epithelium, was assessed and proved helpful, although it was not expressed in all cases. Furthermore, we investigated the expression of 14-3-3σ and cyclooxygenase 2 (COX-2). Based on the frequent expression of 14-3-3σ, this marker appears to have a role in canine OETs since it is not expressed in normal canine ovaries. The infrequent expression of COX-2 suggests that it is a poor candidate as a potential therapeutic target in canine OvCas.

CD117 expression in canine ovarian tumours.

Canine ovarian cancer poses a significant diagnostic and therapeutic challenge. The heterogeneous nature of ovarian tumours makes accurate histological identification difficult, whilst treatment is limited to surgical excision. The tyrosine kinase receptor CD117 is neo-expressed in many tumours and represents a potential diagnostic and prognostic biomarker and therapeutic target. This study aimed to establish if CD117 is neoexpressed in canine ovarian tumours. Immunohistochemistry was employed to assess expression of CD117 in 29 canine ovarian tumour samples. CD117 labelling was assessed with a semiquantitative immunoreactivity score, and the location of labelling was recorded as membranous, focal cytoplasmic or diffuse cytoplasmic. Histological morphology was assessed and used to assign subgroups based on growth pattern. Cytokeratin 7 labelling was used to indicate the tumour type as epithelial or sex-cord stromal in origin. Mitotic index, percentage of necrosis and vascular invasion were also assessed and evaluated for association with CD117 expression. Overall, 81% of ovarian tumours neoexpressed CD117 and normal ovarian tissue did not express CD117. Positive immunolabelling was seen in a subset of cells in both ovarian carcinomas (n = 20) and ovarian granulosa cell tumours (n = 3). There was no association between CD117 expression and patient age, histological subtype, mitotic index, percentage of necrosis or vascular invasion. This is the largest study to identify the expression of CD117 in canine ovarian tumours, but further research is needed to elucidate its prognostic and therapeutic value.

Surrogate indices of insulin resistance using the Matsuda index as reference in adult men-a computational approach.

Background: Overweight and obesity, high blood pressure, hyperglycemia, hyperlipidemia, and insulin resistance (IR) are strongly associated with non-communicable diseases (NCDs), including type 2 diabetes, cardiovascular disease, stroke, and cancer. Different surrogate indices of IR are derived and validated with the euglycemic-hyperinsulinemic clamp (EHC) test. Thus, using a computational approach to predict IR with Matsuda index as reference, this study aimed to determine the optimal cutoff value and diagnosis accuracy for surrogate indices in non-diabetic young adult men. Methods: A cross-sectional descriptive study was carried out with 93 young men (ages 18-31). Serum levels of glucose and insulin were analyzed in the fasting state and during an oral glucose tolerance test (OGTT). Additionally, clinical, biochemical, hormonal, and anthropometric characteristics and body composition (DEXA) were determined. The computational approach to evaluate the IR diagnostic accuracy and cutoff value using difference parameters was examined, as well as other statistical tools to make the output robust. Results: The highest sensitivity and specificity at the optimal cutoff value, respectively, were established for the Homeostasis model assessment of insulin resistance index (HOMA-IR) (0.91; 0.98; 3.40), the Quantitative insulin sensitivity check index (QUICKI) (0.98; 0.96; 0.33), the triglyceride-glucose (TyG)-waist circumference index (TyG-WC) (1.00; 1.00; 427.77), the TyG-body mass index (TyG-BMI) (1.00; 1.00; 132.44), TyG-waist-to-height ratio (TyG-WHtR) (0.98; 1.00; 2.48), waist-to-height ratio (WHtR) (1.00; 1.00; 0.53), waist circumference (WC) (1.00; 1.00; 92.63), body mass index (BMI) (1.00; 1.00; 28.69), total body fat percentage (TFM) (%) (1.00; 1.00; 31.07), android fat (AF) (%) (1.00; 0.98; 40.33), lipid accumulation product (LAP) (0.84; 1.00; 45.49), leptin (0.91; 1.00; 16.08), leptin/adiponectin ratio (LAR) (0.84; 1.00; 1.17), and fasting insulin (0.91; 0.98; 16.01). Conclusions: The computational approach was used to determine the diagnosis accuracy and the optimal cutoff value for IR to be used in preventive healthcare.

Tumor de células gigantes de tejidos blandos del seno esfenoidal / Giant soft tissue tumor of the sphenoid sinus

Introducción: el tumor primario de células gigantes de tejido blando de bajo potencial maligno es un tumor raro. Se han reportado en varios sitios, incluyendo mama, glándulas salivales, pulmón, entre otros. En el cráneo representan el 1 % y afectan preferentemente al esfenoides y los huesos temporales con bajo potencial de transformación maligna. Caso: se presenta el caso de un paciente masculino de 27 años con disminución de agudeza visual izquierda rápidamente progresiva, con evidencia de defecto pupilar aferente izquierdo. La tomografía computarizada (TC) y resonancia magnética nuclear (RMN) muestran una lesión tumoral en topografía esfenoidal izquierda con extensión hacia el seno cavernoso del mismo lado que desplaza la hipófisis. Discusión: el objetivo es describir la frecuencia de la enfermedad y las características en su presentación, definir pautas para el abordaje, tratamiento y seguimiento; asimismo, establecer los factores pronósticos. Conclusiones: tumor de ubicación y presentación inusual.

Introduction: Primary tumor of giant soft tissue cells with low malignant potential is a rare tumor. They have been reported in several sites, including breast, salivary glands, lung, etc. Giant cell tumors of the skull represent 1%, preferably affects the sphenoid and temporal bones. With low potential for malignant transformation. Methods: The case of a 27-year-old male patient is presented, with decrease in left visual acuity, rapidly progressive; with evidence of left afferent pupillary defect. CT and NMR are requested finding tumor lesion in left sphenoid topography with extension to the cavernous sinus of the same side displacing the pituitary gland. Discussion: The objective of the case report is to describe the frequency of the di-sease and the characteristics in its presentation, define guidelines for the approach, treatment and follow-up; also establish the prognostic factors. Conclusions: Tumor of unusual location and presentation.

Síndrome destructivo de línea media secundario a infección por Paracoccidioides sp. Reporte de un caso

El síndrome destructivo de línea media es un grupo de enfermedades inflamatorias y tumorales destructivas del área centrofacial, entre las cuales la paracoccidioidomicosis es una de las etiologías a considerar en los países del trópico. La paracoccidioidomicosis es causada por hongos del género Paracoccidioides. Su forma de blastoconidia favorece la diseminación hematógena, afectando diversos tejidos como glándulas suprarrenales, tejido retículo-endotelial o mucosa oral, esta última donde puede manifestarse como un síndrome destructivo de línea media. Presentamos un caso de paracoccidioidomicosis con afección en cavidad oral, el cual debutó como un síndrome destructivo de línea media crónico, asociado a compromiso grave de la vía aérea que requirió manejo quirúrgico por riesgo de obstrucción y presentó mejoría con manejo antimicótico sistémico.

Summary Midline destructive disease is a group of severe and destructive inflammatory and tumor diseases of the midface area, among which paracoccidioidomycosis is one of the main etiologies in tropical countries. Paracoccidioidomycosis is an endemic mycosis caused by fungi of the genus Paracoccidioides. Its blastoconidia form favors hematogenous spread, affecting various tissues such as adrenal glands, reticulo-endothelial tissue, or oral mucosa, where it can manifest as a destructive midline syndrome. We present a case of paracoccidioidomycosis with affection in the oral cavity, which debuted as a chronic midline destructive disease with sever airway compromise that required surgical treatment for the risk of obstruction of the airway. The patient received systemic treatment with good response.

Metagenomic Insights Into the Microbial Iron Cycle of Subseafloor Habitats.

Microbial iron cycling influences the flux of major nutrients in the environment (e.g., through the adsorptive capacity of iron oxides) and includes biotically induced iron oxidation and reduction processes. The ecological extent of microbial iron cycling is not well understood, even with increased sequencing efforts, in part due to limitations in gene annotation pipelines and limitations in experimental studies linking phenotype to genotype. This is particularly true for the marine subseafloor, which remains undersampled, but represents the largest contiguous habitat on Earth. To address this limitation, we used FeGenie, a database and bioinformatics tool that identifies microbial iron cycling genes and enables the development of testable hypotheses on the biogeochemical cycling of iron. Herein, we survey the microbial iron cycle in diverse subseafloor habitats, including sediment-buried crustal aquifers, as well as surficial and deep sediments. We inferred the genetic potential for iron redox cycling in 32 of the 46 metagenomes included in our analysis, demonstrating the prevalence of these activities across underexplored subseafloor ecosystems. We show that while some processes (e.g., iron uptake and storage, siderophore transport potential, and iron gene regulation) are near-universal, others (e.g., iron reduction/oxidation, siderophore synthesis, and magnetosome formation) are dependent on local redox and nutrient status. Additionally, we detected niche-specific differences in strategies used for dissimilatory iron reduction, suggesting that geochemical constraints likely play an important role in dictating the dominant mechanisms for iron cycling. Overall, our survey advances the known distribution, magnitude, and potential ecological impact of microbe-mediated iron cycling and utilization in sub-benthic ecosystems.

Impact of COVID-19 on the surgical volume of general surgery residents as main surgeons in a National Training Program in Costa Rica: A cross-sectional study.

ABSTRACT: To quantify the impact of coronavirus disease 19 (COVID-19) on the surgical volume of residents' medical practice in Costa Rica's General Surgery Residency Program.The COVID-19 pandemic has caused a significant disruption in people's lives. Health systems worldwide have been forced to adapt to the new normal, which has posed a challenge for medical residency programs, especially in the surgical field.This transversal study includes the surgical records of all residents of the General Surgery program who worked as main surgeons at the Mexico Hospital of the Costa Rican Social Security between December 23, 2019, and June 25, 2020.As main surgeons, a total of 10 residents performed 291 pre-pandemic surgeries and 241 pandemic surgeries.When comparing the distribution of procedures performed by residency levels, it is observed that the postgraduate year -2 increased the number of procedures performed during the pandemic period (pre-pandemic 19% vs pandemic 27%, P = .028). There was no statistically significant difference between the pre-pandemic and pandemic periods in the remaining levels.When comparing the procedures by unit, a statistically significant decrease was observed in the Endocrine-Abdominal Wall Unit (pre-pandemic 18.3% vs pandemic 5.4%, P < .001). Conversely, a statistically significant increase was identified in Surgical Emergencies Unit procedures (40.0% vs post 51.7%, P = .007). No statistically significant differences were observed in the remaining the Units.The COVID-19 pandemic had no statistically significant effect on surgeries performed by residents of the General Surgery Residency Program as main surgeons in a national training center in Costa Rica. The Department's timely measures and pro-resident attitude were the key reasons for the above results.

Canine Gastric Carcinomas: A Histopathological and Immunohistochemical Study and Similarities with the Human Counterpart.

Canine gastric carcinoma (CGC) affects both sexes in relatively equal proportions, with a mean age of nine years, and the highest frequency in Staffordshire bull terriers. The most common histological subtype in 149 CGC cases was the undifferentiated carcinoma. CGCs were associated with increased chronic inflammation parameters and a greater chronic inflammatory score when Helicobacter spp. were present. Understanding the molecular pathways of gastric carcinoma is challenging. All markers showed variable expression for each subtype. Expression of the cell cycle regulator 14-3-3σ was positive in undifferentiated, tubular and papillary carcinomas. This demonstrates that 14-3-3σ could serve as an immunohistochemical marker in routine diagnosis and that mucinous, papillary and signet-ring cell (SRC) carcinomas follow a 14-3-3σ independent pathway. p16, another cell cycle regulator, showed increased expression in mucinous and SRC carcinomas. Expression of the adhesion molecules E-cadherin and CD44 appear context-dependent, with switching within tumor emboli potentially playing an important role in tumor cell survival, during invasion and metastasis. Within neoplastic emboli, acinar structures lacked expression of all markers, suggesting an independent molecular pathway that requires further investigation. These findings demonstrate similarities and differences between dogs and humans, albeit further clinicopathological data and molecular analysis are required.

Cutaneous Spindle Cell Squamous Cell Carcinoma in Cats: Clinical, Histological, and Immunohistochemical Study.

This study describes the clinical and pathological characteristics of cutaneous spindle cell squamous cell carcinoma (SCSCC) in 18 cats. The average age of the cats was 11.8 ± 2.7 years, and all tumors were located in the facial skin, mainly affecting the pinna (13/18, 72%), followed by the periorbital area (4/18, 22%) and the dorsal muzzle (1/18, 6%). Tumors were composed of fusiform neoplastic cells with moderate atypia arranged in solid sheets or fascicles with foci of squamous differentiation. A panel of antibodies against cytokeratins, vimentin, S-100 protein, NSE, GFAP, Melan A, SMA, desmin, CD18, CD31, and p63 was used to help differentiate SCSCC from other spindle cell malignancies. SCSCCs expressed CK5/6 (17/18, 94%), AE1/AE3 (15/18, 83%), and p63 protein (18/18, 100%), but there was no immunolabeling for CK8/18. A role for sunlight exposure in the pathogenesis of the tumors was suggested by changes indicative of actinic keratosis, the location of the tumors in dorsal areas, and the absence of histomorphologic features of papillomavirus infection. Recurrence was not recorded in 14/18 cases (78%) during a follow-up period of 7 to 25 months. Three of 18 (17%) tumors recurred or led to humane euthanasia due to local progression, and one case (5%) had regional lymph node metastasis. Clinical outcome varied with cutaneous location, mitotic count, and invasion of surgical margins; thus, SCSCCs with a more aggressive behavior were located in the periorbital area (4/4 cases), had ≥14 mitoses in 10 high-power fields (2.37 mm2) (4/4 cases), and showed invasion of surgical margins (3/4 cases).

Canine Tonsillar Polyps: Characteristics, Classification, and Review of the Pathogenesis.

Canine tonsillar polyps are uncommon. We describe 14 tonsillar polyps in dogs and review their classification and pathogenesis. All dogs were adult (3-13 years old). Females (10/14) were more affected than males (4/14). Most of the lesions were asymptomatic (10/14). All lesions were unilateral, pedunculated (9/14), or sessile (5/14), with a smooth (12/14) or papillary/verrucous surface (2/14). Histologically, polyps consisted of benign proliferation of lymphatic vessels, blood vessels, fibrous tissue, and lymphoid tissue in variable proportions, with occasional adipose tissue (4/14). According to the main stromal components, polyps were categorized as lymphangiomatous (5/14), lymphangiolipomatous (2/14), lymphangiofibromatous (2/14), angiofibromatous (1/14), angiofibrolipomatous (1/14), lymphoid (2/14), and myxomatous (1/14). As the pathogenesis of these polyps remains unclear, we propose to replace the term inflammatory tonsillar polyp by a morphological diagnosis based on the stromal characteristics of the lesions. Simple surgical excision was curative in the 9 cases with available follow-up information.

Atypical hemolytic-uremic syndrome (aHUS) / Síndrome hemolítico urémico atípico (SHUa)

Abstract Atypical hemolytic-uremic syndrome (aHUS) is a diagnosis of exclusion which should be proposed in cases where there is microangiopathic hemolytic anemia, thrombocytopenia and acute kidney injury. It is associated with mutations which cause dysregulation of the complement system and implies an adverse prognosis and a high risk of progression to chronic kidney disease. Following, we present the case of a patient with aHUS, highlighting the effect and importance of biologic therapy with the monoclonal antibody eculizumab. (Acta Med Colomb 2019; 44. DOI:https://doi.org/10.36104/amc.2019.1301).

Resumen El síndrome hemolítico urémico atípico (SHUa) constituye un diagnóstico de exclusión que debe plantearse ante la presencia de anemia hemolítica microangiopática, trombocitopenia y lesión renal aguda. Está asociado con mutaciones que provocan una disregulación del sistema del complemento e implica un pronóstico adverso y alto riesgo de progresión a enfermedad renal crónica. A continuación, presentamos el caso de un paciente con SHUa resaltando el efecto e importancia de la terapia biológica con el anticuerpo monoclonal eculizumab. (Acta Med Colomb 2019; 44. DOI:https://doi.org/10.36104/amc.2019.1301).

Computed tomographic retrograde positive contrast cystography and computed tomographic excretory urography characterization of a urinary bladder diverticulum in a dog.

A one-year-old intact male German shepherd dog was referred with a 3-month history of dysuria and pollakiuria. Physical examination revealed a large firm mass in the caudal abdomen. Findings from survey radiography, negative contrast cystography, computed tomographic (CT) retrograde positive contrast cystography, and CT excretory urography were consistent with a large urinary bladder diverticulum. An exploratory laparotomy revealed a normal wall appearance in the ventral compartment (true bladder) and marked thinning of the wall in the dorsal compartment (diverticulum). Both ureters inserted into the ventral compartment. The dorsal compartment was excised and histopathology confirmed the diagnosis of urinary bladder diverticulum.

Study on the Role of Histochemical Stains in Identifying Merkel Cells in Dogs.

Merkel cells (MCs) are neuroendocrine cells involved with tactile sense, growth, differentiation, and homeostasis of the skin as well as in different cutaneous diseases. Specific staining techniques are required for their identification because they are not easily visible in paraffin sections stained with hematoxylin and eosin. The present study assess the histochemical features of the MCs in dogs comparing with those described for other mammals in the literature and with the use of immunohistochemistry. A systematic study of samples from MCs-rich areas from healthy dogs was carried out by use of several histologic stains, including metachromatic staining, silver stains, methylene blue, periodic acid-Schiff stain, and osmium-based staining method. MCs were detected by the Grimelius argyrophilic stain in 86.7% of the specimens. The staining was showed as dark-brown granular cytoplasmic and consistently polarized to the basal cell cytoplasm matching with the cellular distribution of the characteristic neurosecretory granules. Some modifications in the standard staining protocol, including rinsing, silver reimpregnation, and counterstain dye, enhanced the MCs identification in stratified squamous epithelium. When compared with Cytokeratin 20-immunolabeled serial sections several MCs appeared nonstained with the argyrophilic method. These differences in MC numbers between stains were statistically significant. Other histologic stains failed to identify MCs in the specimens. The results of this study indicate that Grimelius argyrophilic stain is a suitable method for demonstration of MCs in the stratified squamous epithelium of skin and mucosa. Discussion on its utility when compared with immunohistochemistry and a review of the scientific literature is also presented. Anat Rec, 302:1458-1464, 2019. © 2018 Wiley Periodicals, Inc.

Matrix metalloproteinase-9 deficiency protects mice from severe influenza A viral infection.

Matrix metalloproteinase-9 (MMP-9) cleaves various proteins to regulate inflammatory and injury responses. However, MMP-9's activities during influenza A viral (IAV) infections are incompletely understood. Herein, plasma MMP-9 levels were increased in patients with pandemic H1N1 and seasonal IAV infections. MMP-9 lung levels were increased and localized to airway epithelial cells and leukocytes in H1N1-infected WT murine lungs. H1N1-infected Mmp-9-/- mice had lower mortality rates, reduced weight loss, lower lung viral titers, and reduced lung injury, along with lower E-cadherin shedding in bronchoalveolar lavage fluid (BALF) samples than WT mice. H1N1-infected Mmp-9-/- mice had an altered immune response to IAV with lower BALF PMN and macrophage counts, higher Th1-like CD4+ and CD8+ T cell subsets, lower T regulatory cell counts, reduced lung type I interferon levels, and higher lung interferon-γ levels. Mmp-9 bone marrow-chimera studies revealed that Mmp-9 deficiency in lung parenchymal cells protected mice from IAV-induced mortality. H1N1-infected Mmp-9-/- lung epithelial cells had lower viral titers than H1N1-infected WT cells in vitro. Thus, H1N1-infected Mmp-9-/- mice are protected from IAV-induced lung disease due to a more effective adaptive immune response to IAV and reduced epithelial barrier injury due partly to reduced E-cadherin shedding. Thus, we believe that MMP-9 is a novel therapeutic target for IAV infections.

Tromboembolismo pulmonar de alto riesgo e isquemia cerebral aguda: presentación de caso / High-risk pulmonary thromboembolism in patients with acute cerebral ischemia: case report

La presentación de tromboembolismo pulmonar de alto riesgo en paciente con evento isquémico cerebral agudo, a pesar de ser infrecuente, implica alto riesgo de morbimortalidad y un reto para el clínico respecto a su manejo. La trombolisis como manejo inicial está contraindicada dado el riesgo incrementado de sangrado intracraneal, por tal motivo deben plantearse otras terapias alternativas de reperfusión. Presentamos el caso de una paciente de 45 años con cuadro clínico de seis meses de evolución dado por cefalea en quien se diagnosticó aneurisma del segmento cavernoso de la arteria carótida interna izquierda, sometiéndose a embolización y presentando migración de múltiples trombos desde posición proximal de stent, con trombolisis fallida y desarrollo de isquemia hemisférica ipsilateral; quien posteriormente presenta tromboembolismo pulmonar de alto riesgo, manejado mediante tromboaspiración y trombolisis farmacológica selectiva guiada por catéter e implantación de filtro de vena cava inferior. La trombolisis farmacológica selectiva guiada por catéter constituye la estrategia de reperfusión con la mejor relación riesgo/beneficio en el contexto de isquemia cerebral aguda y tromboembolismo pulmonar de alto riesgo. Asimismo, es posible utilizar otras alternativas para disminuir el riesgo de recurrencia, tales como los filtros venosos y la compresión neumática intermitente..(AU)

The presence of high risk pulmonary thromboembolism in a patient with an acute cerebral ischemic event, although infrequent, poses a high risk of morbimortality and a challenge in its handling. The Thrombolysis as a first treatment is contraindicated given the risk of high intracranial bleeding. For this reason, it is important to propose alternative reperfusion treatments. We present the case of a 45 years old patient with a clinical picture of a six months follow up of headaches that was diagnosed with an aneurism of the cavernous segment of the internal left carotid artery, subjected to embolization and presenting migration of multiple thrombi from stent proximal end, with failed thrombolysis and the development of ipsilateral hemispheric ischemia; who later presents high risk pulmonary thromboembolism, handled through thromboaspiration and selective pharmacological thrombolysis guided by a catheter and the implementation of a filter in the inferior vena cava. The selective pharmacological thrombolysis guided by catheter makes up the strategy of reperfusion with the best risk/benefit rate in the context of acute cerebral ischemia and high risk pulmonary thromboembolism. Likewise, it is possible to use other treatments to lower the risk of recurrence, such as venous filters and intermittent pneumatic compression..(AU)

Mandibular odontogenic sarcoma (ameloblastic fibrodentinosarcoma) in an aged cat - Short communication.

A 13-year-old male cat presented with an ill-defined mass in the rostral mandible causing destruction and loss of alveolar bone. Microscopically, the mass consisted of cords or islands of benign odontogenic epithelium and a malignant, pleomorphic spindle-shaped cell component with dysplastic dentine formation. Immunohistochemically, neoplastic mesenchymal cells proved to be strongly positive for vimentin and negative for cytokeratins, desmin, actin and S100 protein; the Ki67 proliferation index was high. Morphological and immunohistochemical features largely overlap those reported for ameloblastic fibrodentinosarcoma, an uncommon histologic subtype of odontogenic sarcoma recognised in humans but no reported previously in animals. Ki-67 expression assessment may help to discriminate between malignant and benign forms of odontogenic tumours but the final diagnosis is mainly morphological.

In-situ incubation of iron-sulfur mineral reveals a diverse chemolithoautotrophic community and a new biogeochemical role for Thiomicrospira.

Sulfide mineral precipitation occurs at mid-ocean ridge (MOR) spreading centers, both in the form of plume particles and seafloor massive sulfide structures. A common constituent of MOR is the iron-bearing sulfide mineral pyrrhotite, which was chosen as a substrate for in-situ incubation studies in shallow waters of Catalina Island, CA to investigate the colonization of iron-oxidizing bacteria. Microbial community datasets were obtained from in-situ incubated pyrrhotite, allowing for direct comparison to microbial communities of iron-sulfides from active and inactive chimneys in deep-sea environments. Unclassified Gammaproteobacteria and Alphaproteobacteria (Magnetovibrio) largely dominated the bacterial community on pyrrhotite samples incubated in the water column while samples incubated at the surface sediment showed more even dominance by Deltaproteobacteria (Desulfobulbus), Gammaproteobacteria (Piscirickettsiaceae), Alphaproteobacteria (Rhodobacteraceae), and Bacteroidetes (Flavobacteriia). Cultivations that originated from pyrrhotite samples resulted in the enrichment of both, sheath-forming and stalk-forming Zetaproteobacteria. Additionally, a putative novel species of Thiomicrospira was isolated and shown to grow autotrophically with iron, indicating a new biogeochemical role for this ubiquitous microorganism.

Anticoagulación oral en el adulto mayor frágil con fibrilación auricular / Oral anti-clotting in the fragile elderly with atrial fibrillation

Introducción: El envejecimiento incrementa el riesgo de trombosis y fenómenos embólicos, trae cambios fisiológicos y comorbilidades como la fibrilación auricular que hacen complejo el inicio y la seguridad de la anticoagulación. A pesar de la mayor disponibilidad de clínicas de anticoagulación y nuevos anticoagulantes orales, es bajo el porcentaje de adultos mayores que están anticoagulados aunque tengan indicación plena y ausencia de contraindicaciones. Objetivo: Revisar las principales estrategias para predecir y disminuir el riesgo de sangrado con el empleo de anticoagulantes orales en pacientes adultos mayores frágiles. Metodología: Se realizó una búsqueda sistemática sobre estudios que evaluaran la seguridad y eficacia de anticoagulantes orales en pacientes con fibrilación auricular en adultos mayores de 65 años, y una búsqueda de estudios sobre el síndrome de fragilidad y su impacto en el adulto mayor anticoagulado. Resultados y Discusión: Se ha denominado fragilidad al porcentaje de adultos mayores que presentan un mayor deterioro de sus sistemas biológico, físico y cognitivo, conduciendo a una mayor probabilidad de desenlaces adversos en salud, discapacidad y muerte. Se han estudiado características clínicas que permiten identificar pacientes como frágiles; el fenotipo de fragilidad de Linda Fried evalúa esas características; además, existen estrategias de monitoreo de los anticoagulantes orales que deben ser conocidos para minimizar el riesgo de eventos adversos. Conclusiones: el anciano frágil presenta factores de riesgo que probablemente afectan la eficacia y seguridad de la terapia con anticoagulantes orales. Las guías clínicas existentes no proveen la suficiente evidencia y no consideran de manera multidimensional al paciente geriátrico...(AU)

Introduction: Aging increases the risk of thrombosis and embolic phenomena. It also brings physiological changes, and comorbidities such as atrial fibrillation that makes complex the onset and safety of anti-clotting. Despite the greater availability of anti-clotting clinics and new oral anticoagulants, the percentage of elderly who are anticoagulated is low, even though they have indications and no contraindications. Objective: To review the main strategies to predict and reduce the risk of bleeding with the use of oral anti-clotting in fragile elderly patients. Methodology: A systematic search was conducted on studies evaluating the safety and efficacy of oral anticoagulants in patients with atrial fibrillation in adults older than 65 years, and a search for studies on the frailty syndrome and its impact on the elderly anticoagulated. Results and Discussion: Fragility has been termed to the percentage of elderly who were diagnosed with a greater deterioration of their biological, physical and cognitive systems, leading to a greater probability of adverse outcomes in health, disability and death. Some clinical features have been studied to identify patients as fragile; Linda Fried's frailty phenotype evaluates these characteristics; furthermore, there are strategies for monitoring oral anticoagulants that should be known to reduce the risk of adverse events. Conclusions: The frail elderly has some risk factors that are likely to affect the efficacy and safety of oral anti-clotting therapy. Existing clinical guidelines do not provide enough evidence and do not consider the elderly patient in a multidimensional manner...(AU)

Introdução: O envelhecimento aumenta o risco de trombose e embolias, traz mudanças fisiológicas e comorbidades como a fibrilhação auricular que fazem complexo o inicio e a segurança da anticoagulação. Apesar do aumento da disponibilidade das clínicas de anticoagulação e novos anticoagulantes orais, é baixa a percentagem de adultos mais velhos que tomam anticoagulantes ou que tenham a indicação completa e ausência de contra-indicações. Objetivo: Revisar as principais estratégias de prever e reduzir o risco de sangramento com o uso de anticoagulantes orais nos pacientes idosos mais frágeis. Metodologia: Se fez uma revisão sistemática de estudos que avaliaram a segurança e eficácia de anticoagulantes orais nos pacientes com fibrilhação auricular em adultos com mais de 65 anos, e uma busca dos estudos sobre o síndrome de fragilidade e o seu impacto nos idosos anticoagulado. Resultados e Discussão: Foi chamada de fragilidade a percentagem de pessoas idosas com maior deterioro de seus sistemas biológicos, físicos e cognitivos, levando-as a uma probabilidade maior de resultados adversos na saúde, invalidez e morte. Foram estudadas as características clínicas que identificam pacientes como pacientes frágil; o fenótipo de fragilidade de Linda Fried avalia estas características; além disto, existem estratégias adicionais de monitoramento de anticoagulantes orais que devem ser conhecidos para minimizar o risco de fatos adversos. Conclusões: Os idosos frágeis presentam fatores de risco que podem afectar a eficácia e segurança da terapia com anticoagulantes orais. As diretrizes clínicas existentes não são claras nem as provas são suficientes. Além disto, não consideram de forma multidimensional aos pacientes geriátricos...(AU)