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En el presente estudio se realiza un estudio social, desde un enfoque multidisciplinario, desde factores demográficos y socioeconómicos que influyen en la reproducción de vulnerabilidades sociales en una comunidad residencial cubana, sin negar los logros obtenidos en Cuba y la prioridad que esta sociedad otorga a la búsqueda de mayores grados de igualdad. Los autores, por consiguiente, no limitan su acercamiento al tema desde una mirada a los factores internos y externos que generan una creciente complejidad de la sociedad cubana, a nivel regional y de comunidad local; sino que, principalmente, a partir de la interpretación de los resultados de un estudio empírico en una comunidad residencial, y sin perder de vista las interrelaciones macro-meso y micro sociales, se acercan a factores interrelacionados, como color de la piel, grupo etario, origen territorial, tipo de barrio residencial, tipo de familia y situación socioeconómica, lo que en conjunto verifica y amplía los resultados de otros estudios sobre el tema, realizados en la sociedad cubana. Palabras clave: Comunidad, factores demográficos, socioeconómicos. ABSTRACT In the present study, a social study is carried out, from a multidisciplinary approach, from demographic and socioeconomic factors that influence the reproduction of social vulnerabilities in a Cuban residential community, without denying the achievements obtained in Cuba and the priority that this society gives to the search for greater degrees of equality. The authors, therefore, do not limit their approach to the topic to a look at the internal and external factors that generate a growing complexity in Cuban society, at the regional and local community level; Rather, mainly from the interpretation of the results of an empirical study in a residential community, and without losing sight of the macro-meso and micro social interrelations, they approach interrelated factors, such as skin color, age group, territorial origin, type of residential neighborhood, type of family and socioeconomic situation, which together verify and expand the results of other studies on the subject, carried out in Cuban society. Keywords: Community, demographic, socioeconomic factors.

Recent updates in national guidelines for management of acute ischemic stroke in patients of unknown time of symptom onset (“wake-up” strokes) incorporate, for the first time, use of emergent MRI. In this retrospective case series, we analyze our experience at a Comprehensive Stroke Center implementing a new workflow including MRI in this clinical setting. This study also describes “DWI-FLAIR” mismatch, a critical concept for the interpretation of emergent brain MRIs performed for wake-up strokes. Over a 14-month period, all brain MRIs for wake-up stroke were identified. The imaging was analyzed by two board-certified, fellowship-trained neuroradiologists, and a diagnosis of DWI-FLAIR mismatch was made by consensus. Process metrics assessed included interval between last known well time and brain imaging, interval between CT and MRI, and interval between brain MRI and interpretation. Sixteen patients with a history of “wake-up stroke” were identified. Thirteen of the 16 patients (81.3%) were found to have a DWI-FLAIR mismatch, suggesting infarct

La escoria de horno al oxigeno (BOF) se produce durante la transformación del arrabio, proveniente del alto horno, en acero durante el proceso siderúrgico integrado. Este residuo ha generado problemas ambientales debido a la acumulación y no disposición adecuada. Por lo anterior, este estudio tiene como objeto analizar el uso comportamiento del módulo dinámico y la fatiga en mezclas asfálticas con sustitución parcial (50%) y total (100%) del agregado grueso por BOF; los resultados se compararon con el comportamiento de una mezcla elaborada con agregados convencionales. Para alcanzar el objetivo se determinaron las propiedades químicas y físicas de BOF, el contenido óptimo de cemento asfáltico se determinó con la metodología Ramcodes y se realizaron ensayos para evaluar las características físicas, el módulo dinámico y la fatiga de cada tipo de mezcla. Los resultados de este estudio muestran una mejora en el comportamiento a fatiga y una leve disminución en el módulo dinámico en las mezclas con BOF. Lo cual nos permite deducir que es factible el uso de este residuo y así contribuir al desarrollo sostenible y la protección del medio ambiente

Background: Human papillomavirus (HPV) is recognized as the most important cofactor in the etiology of cancers of the cervix, esophagus, larynx, and nasopharynx. Experimental evidence suggests that HPV could have an oncogenic influence on thyroid follicular cells; however, to the best of our knowledge, there is no record of its role in human thyroid gland neoplasms. Objective: The purpose of this study is to describe the frequency and the types of HPV present in neoplastic thyroid tissue by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Methods: Over 157 samples were analyzed of paraffin-embedded tissue from malignant and benign thyroid tumors. All the paraffin blocks were selected consecutively from the Pathology Tissue Bank archive of the Western Medical Center. The molecular detection and typing were performed at the Molecular Microbiology Laboratory of the Biomedical Research Center, Mexican Institute of Social Security. Results: The frequency of HPV findings was 2.5% (four cases). HPV-6 was found in two cases of thyroid hyperplasia (2.5%), and HPV-33 in two cases of papillary cancer (4.6%). Conclusion: The presence of HPV is not frequent in thyroid neoplasms, at least in the studied population. Due to the low prevalence of this virus in our sample, it is not possible to reach conclusions. Further research is needed.

Slag from a Blast Oxygen Furnace (BOF) is produced during the transformation of cast iron, coming from the blast furnace, into steel during the integrated steelmaking process, just as blast furnace dust (BFD) is produced during the transformation of the iron mineral into cast iron. These residues have generated environmental problems due to the accumulation and inadequate disposal thereof. Consequently, this study aims to analyze the use and behavior of the dynamic modulus and the fatigue in asphalt mixtures with partial (50 %) and total (100 %) substitution of the coarse aggregate for BOF slag and the fine aggregate for BFD. The results are compared with the behavior of a mixture elaborated with conventional aggregates. To achieve this objective, the chemical and physical properties of BOF and BFD were determined along with the optimum asphalt cement content, determined using the Ramcodes methodology. Tests were carried out to evaluate the physical characteristics, the dynamic modulus, and the fatigue of each type of mixture. The results of this study demonstrate adequate fatigue behavior and a slight reduction in dynamic modulus in mixtures with BOF and BFD. This allows us to deduce that the use of these residues is feasible and thereby to contribute to sustainable development and the protection of the environment.

In the constantly evolving field of toxicologic pathology, a pathologist’s career is often characterized by multiple career transitions. However, these transitions can be challenging and/or overwhelming and may require a shift in focus, strategic approach, and acquisition of new skills and expertise. In order to provide a forum to discuss challenges associated with career transitions and skill set/competencies required to navigate career changes effectively and successfully, the Career Development and Outreach Committee of the Society of Toxicologic Pathology (STP) sponsored a career development workshop entitled “Transitions in a Pathologist’s Career” in conjunction with the STP 36th annual symposium. The presentations at this workshop provided perspectives of managers from pharmaceutical companies and Contract Research Organizations as well as consultants. This article is designed to provide brief summaries of their talks in this well-received career development workshop.

Instituto de Física y Matemáticas. Maestría en Ciencias en el Área de Física In this work I show the construction and implementation of a code, based on finite volume methods, that solves the Magnetohydrodynamic equations in the ideal and resistive regimes for nonrelativistic velocities. Next, a description of the magnetohydrodynamic equations and the numerical model used to solve them is presented. Later I elaborate on the kind of plasmas that are adequate to be modelled with this system of equations and the necessary restrictions to be imposed on the plasma in order to make an accurate representation of the plasma phenomena. After that I present some standard tests found in literature and the results of running the code with them. Finally, I propose two additional tests that model plasma confinement, and then the results of the simulation are shown. En este trabajo se presenta la construcción e implementación de un código, basado en el método de volúmenes finitos, que resuelve las ecuaciones de la Magnetohidrodinámica en los regímenes ideal y resistivo para velocidades no relativistas en tres dimensiones. Se presenta una descripción tanto de las ecuaciones de la magnetohidrodinámica como del método numérico que se utiliza para resolverlas. Se discute acerca de qué tipo de plasmas se pueden modelar con este sistema de ecuaciones y las restricciones necesarias para que sea válido el modelo. Posteriormente se presentan algunas pruebas estándar en la literatura para validar la capacidad del código, y finalmente se proponen dos pruebas adicionales que modelan algunos tipos de confinamiento de plasma, se muestran los resultados de la simulación en estos sistemas.

Metallurgical slags are residues that are obtained in the manufacturing and smelting processes of metals, such as steel and copper. However, their use is limited because they may cause environmental problems at their disposal sites. This study aims to evaluate the effects of the addition of slag on the properties of slag-modified asphalts using three different slag proportions (3, 6, and 10% by weight of asphalt). Electric arc furnace slag, blast furnace slag, and copper slag were used to evaluate the effects of the addition of slag on their performance properties via physical and rheological tests. The results showed an improvement in the consistency of the slag-modified asphalts, decreasing the penetration rate and increasing the softening point. An enhancement in the short-term asphalt aging characteristics was also observed with the addition of slag. Finally, the rheological test results revealed an improvement in the resistance to permanent deformation with the addition of slag in neat asphalt, whereas no statistically significant results were observed when the slag content was increased.

In this work we present the description and analysis of a palaeoichnological site (7.9TAG) that only contains crocodile tracks. The site contains well preserved and abundant crocodilian manus and pes prints; there are no belly and/or tail traces. The crocodyle tracks have been mapped and the biomorphic and morphometric characters of the tracks and trackways have been studied. Between the digit traces of the pes prints (not in manus prints) there is a graded depression that indicates the presence of a foot webbing. The number of crocodilian footprints (93) and trackways (8) of the site is sufficient to define, and to support with confidence the data shown in the article. As consequence a crocodiliform ichnogenus, Batrachopus has been defined, characterized by the presence of a trace of a probably interdigital membrane in the pes prints, the trace of a bulge on toe V, the lack of tail traces, and the very narrow gauge trackway. A comparative study is done with all the fossil crocodile footprints described so far. The 7.9TAG footprints printed on sediments of Middle?-Upper Jurassic age (Isli Formation) are the first Batrachopus ichnites described both from this age and in the African continent.

This chapter discusses the issues of risk assessment, management, communication, and abatement that are important to the Toxicologic Pathologist to understand the significance of their contribution as it relates to the health of humans and the environment following exposure to products in development for use as pharmaceutical of chemical compounds. The division of the development stages is discussed along with the most important practices to make the contributions of the Toxicologic Pathologist useful to the client, ethically rigorous, and responsive to the needs of the public.

Background. The Toll-like receptor 7 (TLR7) activator imiquimod (IMQ) is safe and effective in treating actinic keratosis; however, an intermittent treatment regimen is necessary because of excessive local reactions. Objectives. To evaluate in vitro potency, pharmacodynamics/pharmacokinetics, toxicity and efficacy in vivo of the newly developed TLR7 ligand-phospholipid conjugate, TMX-202, in a gel formulation. Material and Methods. The effects of TMX-202 were assessed both in vitro on a murine macrophage cell line and in primary bone marrow-derived dendritic cells and in vivo on mice (C57BL/6-wild type, Myd88 -/- and Tlr7 -/- ). Results. TMX-202 was more potent than IMQ in vitro using murine and human cells. In contrast, in vivo it showed less systemic pro-inflammatory activity and better safety than IMQ. Moreover, the TMX-202 gel formulation exhibited at least comparable efficacy to Aldara in a mouse model for skin proliferative diseases. Conclusion. TMX-202 is safe and efficacious without causing excessive adverse effects, suggesting that it may be an alternative to Aldara for the treatment of proliferative skin conditions.

Background Laparoscopic sleeve gastrectomy (SG) as a single-stage procedure for the treatment of morbid obesity is becoming increasingly popular. In undeveloped countries, the linear staples required to create the sleeve are not always available because of their high cost. As an alternative to the staples, the bipolar vessel sealer device could be used in bariatric surgery to divide and temporarily seal the stomach. Settings Universidad Central de Venezuela, Caracas, Venezuela. Methods Between May 2015 and July 2016, 9 patients with a mean body mass index of 38.2 kg/m 2 were submitted to a stapleless laparoscopic SG using the bipolar vessel sealer for the gastric division. The sleeve was performed over a 42 French bougie and closed with 2 layers of running sutures. Surgical time, morbidity, hospital stay, and excess weight loss were prospectively collected. Results Mean operative time and hospital stay were 117 min and 2.3 days. There was no major morbidity but 2 patients presented a basal atelectasis, which was solved by medical treatment without consequences. After a mean follow up of 6.8 months the mean excess weight loss was 78.4%. Conclusion The technique of stapleless laparoscopic SG presented in this report is a valid alternative when these devices are not available. Large series with long-term follow-up are necessary to make definitive conclusions.

En la Cuba de hoy, amparado por normas juridicas, se perciben relevantes transformaciones relacionadas con las mujeres y las relaciones de genero en varios ambitos de la sociedad, tales como: la significativa disminucion de las desigualdades entre mujeres y hombres en cuanto a educacion, participacion laboral y sociopolitica a todos los niveles; la separacion entre sexualidad y reproduccion, el derecho a controlar la fecundidad; y la superacion de algunas concepciones y prejuicios que estigmatizaban a la mujer. Sin embargo, aun persisten y se reproducen ciertas problematicas que pueden obstaculizar la realizacion plena de la igualdad en las relaciones de genero. El presente articulo tiene como objetivo realizar un analisis transdisciplinar de la igualdad en las relaciones de genero en Cuba, con una mirada desde lo socioeconomico, educativo, juridico y axiologico.

El presente documento plantea una alternativa de utilización del alquitrán de hulla,subproducto de la industria siderúrgica, dado el problema de su acumulación eimpacto ambiental negativo. Por lo anterior, se observa la necesidad de analizar laincorporación de alquitrán de hulla como ligante en mezclas para pavimentos. Deeste modo, inicialmente se presenta la procedencia, descripción de las principalescaracterísticas y propiedades del alquitrán. Seguidamente, se formula y evalúa lamezcla, mediante el procedimiento de las metodologías Marshall y RAMCODES,para determinar su resistencia. Con los resultados obtenidos de los ensayos seobtuvieron las propiedades físicas y mecánicas de la mezcla. Teniendo en cuentalos resultados de las dos metodologías se realiza una comparación para establecerla conveniencia de utilizar la metodología RAMCODES en el diseño de mezclas.Por último, se analiza la alternativa de utilizar el alquitrán de hulla como liganteen mezclas bituminosas para pavimentos.Palabras clave: Alquitrán de hulla, mezclas bituminosas, Marshall, RAMCODES.

The 2011 annual National Toxicology Program (NTP) Satellite Symposium, entitled “Pathology Potpourri,” was held in Denver, Colorado in advance of the Society of Toxicologic Pathology’s 30th Annual Meeting. The goal of the NTP Symposium is to present current diagnostic pathology or nomenclature issues to the toxicologic pathology community. This article presents summaries of the speakers’ presentations, including diagnostic or nomenclature issues that were presented, along with select images that were used for audience voting or discussion. Some lesions and topics covered during the symposium include: proliferative lesions from various fish species including ameloblastoma, gas gland hyperplasia, nodular regenerative hepatocellular hyperplasia, and malignant granulosa cell tumor; spontaneous cystic hyperplasia in the stomach of CD1 mice and histiocytic aggregates in the duodenal villous tips of treated mice; an olfactory neuroblastoma in a cynomolgus monkey; various rodent skin lesions, including follicular parakeratotic hyperkeratosis, adnexal degeneration, and epithelial intracytoplasmic accumulations; oligodendroglioma and microgliomas in rats; a diagnostically challenging microcytic, hypochromic, responsive anemia in rats; a review of microcytes and microcytosis; nasal lesions associated with green tea extract and Ginkgo biloba in rats; corneal dystrophy in Dutch belted rabbits; valvulopathy in rats; and lymphoproliferative disease in a cynomolgus monkey.

The June 2009 Town Hall meeting of the Society of Toxicologic Pathology (STP) and a subsequent survey considered whether or not STP should endorse a published proposal ( Toxicol Pathol 37: 553–561, 2009) by the International Federation of Societies of Toxicologic Pathologists (IFSTP) to provide global recognition by credential review for toxicologic pathologists engaged in regulatory-type, nonclinical toxicology studies. One-third (374 of 1082) of STP members answered the survey. The majority of respondents rejected the IFSTP proposal (55% against) but favored the concept of global recognition (57% for), if available to both anatomic pathologists and clinical pathologists (67% for). Members preferred recognition by credential review (49% for) or via an internationally authored “best practices” document detailing the ideal educational and work experiences required for entry-level proficiency in toxicologic pathology (43% for). Therefore, the STP Executive Committee does not endorse the current IFSTP proposal but will continue discussions on global recognition of qualified toxicologic pathologists with other societies of toxicologic pathology.

The neurotoxin MPTP is widely used to cause damage to the dopaminergic system in rodents and non-human primates to model various aspects of Parkinson's disease. In mice, depletion of striatal dopamine is the commonly used endpoint to assess neuronal damage. However, it has proved technically challenging to quantify dopaminergic cell bodies as an index of neuronal integrity. To meet this challenge, we applied laser pressure catapult microdissection (LCM) of the substantia nigra in combination with quantitative Western blot to provide an index of dopamine neurodegeneration in mice treated with MPTP. Seven days following initiation of MPTP treatment, striatal dopamine depletion was maximal and there was histological evidence of neuronal degeneration in the substantia nigra. To index the integrity of dopamine cell bodies, tyrosine hydroxylase (TH) and beta-actin were quantified by Western blot in LCM extracts. In untreated mice, TH was detected in LCM extracts of substantia nigra but was undetectable in equivalently sized extracts of cortex from the same animals. In MPTP-treated mice, there was a significant 70% reduction in TH relative to beta-actin in LCM extracts as compared to vehicle-injected controls. This reduction corresponded to decreases in striatal dopamine and loss of immunocytochemically detected TH but not beta-actin in the substantia nigra (SN). Thus, this method provides a quantitative means to measure dopamine neuron toxicity in the substantia nigra and, as such has potential application in evaluating regimens that may be neuroprotective or neurorestorative for dopaminergic neurons.

Objective: To integrate radiology more fully into the first year of medical school, each student was provided with a computed tomographic (CT) scan of his or her gross anatomy cadaver before dissection. We describe the imaging findings of these embalmed cadavers. Methods: Eighteen cadavers, embalmed within 2 days of death and stored an average of 8 months, were scanned with multidetector CT. Results: The CT findings provided opportunities for enhanced learning and guidance for the dissection. Specific findings were categorized as postmortem and embalming changes, pathological changes, and iatrogenic changes. Image quality was degraded by beam hardening artifact caused by the arms being placed alongside the body. Differences in attenuation between many soft-tissue structures were reduced, compared with living subjects. Conclusions: Findings on CT scans of embalmed cadavers show significant differences from CT scans of living patients, due to postmortem state and artifacts of preservation.

Rationale and Objectives Our goal is to design, implement, and evaluate a rich educational activity to engage medical students in learning the importance of providing clinical histories when ordering radiological examinations. We adapted the format of the case method commonly used in business schools. Materials and Methods In the setting of a 1-week required radiology course offered during the third year of medical school, we created an unknown case assignment consisting of two chest radiographs and a concise history for three- to four-person study teams. Unknown to students, each team received the same images, but different patient histories. After turning in their written analyses, students had a classroom opportunity to discuss their conclusions. A written evaluation of the entire experience using both Likert items and unstructured response items was conducted at the end of each session. Results The evaluation was conducted during a 17-month period, and 141 evaluations were received from students. The response rate was 100%. Most teams met several times and worked on the assignment for 2 or 3 hours. Students agreed that the learning experience was worthwhile (95%), content was appropriate (93%), and the activity should be continued for subsequent classes (94%). Unstructured responses indicated that students learned the importance of clinical histories in the interpretation of radiological studies. Conclusion An educational activity based on the case method was well received by students and met its educational objectives. Activities of this type have potential for widespread application in radiology education.

Rationale and objective Enormous resources are spent on the selection process for radiology residency, yet agreement on criteria, process, and outcome remains elusive. The aim was to develop, implement, and evaluate a spreadsheet application that streamlined the creation of a match list for resident selection. Materials and methods The Department of Radiology’s traditional procedure of screening, interviewing, and rating candidates was left intact because the selection committee could not reach consensus regarding possible improvements in the process or outcome measures. We developed a spreadsheet application that used the ratings of candidate desirability for our program from our preexisting process to create a tentative match list by adding a system of ordinal ranking and weighting. After 4 years of use, the fairness and usefulness of this application were evaluated by members of the selection committee by means of a survey. Results The spreadsheet application was used to create tentative match lists for 4 years. The system eliminated ties among candidates on the preliminary match list and met the expectations of a majority of the selection committee members for fairness, objectivity, efficiency, and results. Conclusion A spreadsheet application can streamline the process of resident selection without having to resolve underlying conflicts about selection criteria and outcome measures.

Accurate interpretation of microscopic changes in tissues is critical in hazard identification and risk assessment. To address a possible confounder, the effects of postmortem interval on hepatocyte vacuolation and liver weight were studied in fasted and nonfasted Sprague-Dawley rats. Male and female rats (5/sex/interval) were euthanized with CO2, weighed, and necropsied either immediately or after remaining in the closed CO2 chamber for 5, 10, or 25 minutes after respirations ceased. The liver was removed, weighed, and fixed for light microscopy, immunohistochemistry, and electron microscopy. The liver weight and liver to body weight ratio increased significantly in both male and female rats. Postmortem hepatocellular vacuolation was more prominent in males than in females. Both fasted and nonfasted males were similarly affected, however, fasted females were affected more than nonfasted females at the 25-minute interval. Ultrastructurally, intracytoplasmic vacuoles in hepatocytes and/or endothelial cells contained electron-lucent material that was morphologically similar to plasma in sinusoidal spaces. Results of our study suggest that hepatocyte vacuoles were formed in a postmortem time-dependent manner as a result of plasma influx into the cytoplasm. This change was associated with hepatic sinusoidal congestion and increases in liver weight. Males were more sensitive than females to postmortem hepatocyte vacuolation.

ILSI-HESI sponsored an international consortium for the evaluation of alternative models, including the Trp53+ /- mouse, for use in short-term carcinogenicity testing of pharmaceuticals. Products of the ILSI evaluation included guidance for protocol design and assay interpretation, spontaneous tumor incidences, diagnostic criteria for common proliferative lesions, and results of assays for pharmaceutical agents that are known human and/or rodent carcinogens and non-carcinogens. Based on the ILSI evaluation, recommended protocol elements for this model include: 26-week study duration, groups ≥15/sex/dose, a positive control group (benzene or p-cresidine), a negative control group and 3 dose groups, the high dose set at MTD or MFD, routine in-life evaluations, and complete necropsies with microscopic evaluation of tissues. Favored statistical analyses are trend tests or pair-wise comparisons, with no adjustments for survival. For an assay to be valid, positive control groups must demonstrate an effect, and the MTD or MFD must be reached in both sexes. Criteria for a negative response include a valid assay, no statistical increase in common tumors, no biologically significant numerical increase in rare tumors, and no tumor incidence above that of historical controls. Positive responses can consist of statistically significant increases in the incidence of a common tumor or numerical increases in a rare tumor, which may not be statistically significant. In either case, the incidence should be clearly above historical control values. Evidence of a dose response or occurrence of hyperplasia in a tissue with a neoplastic response can support interpreting an assay as positive. The two most common spontaneous tumors (>1%) in Trp53+/- mice are malignant thymic lymphomas and subcutaneous sarcomas. Use of implanted electronic transponders can increase the incidence of sarcomas. Important rare spontaneous tumors (incidence ≤1%) are osteosarcomas and pulmonary adenomas. Many other tumor types have been reported to occur sporadically in Trp53+/- mice. Diagnostic challenges for this model include differentiating lymphoma from atypical thymic hyperplasia and recognizing the variable histopathology of subcutaneous sarcomas. In reported bioassays, Trp53+/- mice responded positively to genotoxic carcinogens, negatively to non-genotoxic rodent carcinogens, and negatively to noncarcinogens, indicating that unlike the 2-year mouse assay, this short-term assay is not overly sensitive. Positive responses often elicited an increase in tumors that occur spontaneously. To successfully use this model, pathologists must understand the biology of the Trp53 tumor suppressor gene and the principles of protocol design and data interpretation for short-term bioassays. They must also know the historical response pattern of Trp53+/- mice to test agents and be able to accurately diagnose tumors in this model. Use of the Trp53+/- mouse presents the pharmaceutical industry with several challenges, one of which is managing the uncertainty created by a lack of precedents for regulatory decisions about some possible outcomes for short-term carcinogenicity assays.

Examination of H&E-stained tongue samples from a 26-week intravenous infusion study of Beagle dogs, utilizing a compound with no recognized effect on mineral metabolism, exhibited superficial stratum corneum calcification in both treated and control animals. This resulted in the search for possible causes of the finding to help clarify confounding issues. Retrospective examination of 11 studies performed before the signal case indicated that the problem existed in the testing facility but was not recognized. Prior to 2008, this finding was not observed, perhaps indicating the requirement for a change in procedures or suppliers. Based on the hypothesis that the calcium salts were deposited from bone during processing, a series of tests was performed by fixing tongue and femur along with different tissues, processed routinely to slide, and stained with H&E and von Kossa stains. We conclude that the presence of superficial stratum corneum calcification of the tongue in dogs demonstrated in toxicology studies is an artifactual change related to the processing of tissues, specifically the fixation of tongue in the same container as bone and stomach. This change should not be confused with compound-related effects, even when the incidence varies between controls and treated animals.

Reports on the effects of cholestyramine on small intestinal structure of rats have produced contradictory data about changes in mucosal histomorphometry, perhaps due to interacting effects of dietary composition. In order to identify effects of cholestyramine and diet on structure of the small intestines, 40 male rats were divided into 4 groups of 10 and fed 1 of each of the following diets for 1 month: standard diet, purified fiber-free diet, standard diet + 2% cholestyramine, or purified fiber-free diet + 2% cholestyramine. Serum concentrations of cholesterol and triglycerides were moderately increased in rats fed the purified fiber-free diet versus the standard diet. Neither total length nor weight of small intestine were affected by either diet or cholestyramine. Mucosal weight was affected by interactions between cholestyramine and diet, indicating that outcome depended upon modulating effects of both variables. Significant interactions were similarly detected among the variables of anatomic site, diet, and cholestyramine for many histomorphometric parameters of intestinal mucosa. Cholestyramine reduced total mucosal thickness in both jejunum and ileum and reduced villus height and villus : crypt ratio in the ileum. Kejwords. Histomorphometry; cholestyramine; small intestine; rat; cholesterol; triglycerides; jejunum; ileum

Avascular Necrosis (AVN) lesions affecting the long bones, especially the femoral and humeral heads, are observed with increased frequency in patients with lupus and antiphospholipid syndrome. However, AVN involving the spine is exceptionally unusual. We report a case that illustrates the importance of considering the diagnosis of AVN when evaluating lesions involving the spine in those patients and the characteristic findings.