Mandibular Myxoid Liposarcoma: a Case Study.

Liposarcomas are described as soft tissue sarcomas derived from adipose tissue. The finding of this tumor in the mandibular region is exceedingly rare. As of now, it has been described mainly in case reports and small series. A multidisciplinary approach is required to offer optimal treatment and may involve surgery, radiation and systemic therapies. Surgical repair of these defects represents a major challenge in oral and maxillofacial reconstructive surgery. We present the case of a 54-year-old man referred to our center with a progressively increasing mass in the anterior portion of the mandible. Biopsy revealed a well-differentiated myxoid liposarcoma. Resection of the tumor was performed with an additional primary reconstruction.

Clinical characteristics, bacterial coinfections and outcomes in COVID-19-associated pulmonary aspergillosis in a third-level Mexican hospital during the COVID-19 pre-vaccination era.

BACKGROUND: Damage due to respiratory viruses increases the risk of bacterial and fungal coinfections and superinfections. High rates of invasive aspergillosis are seen in severe influenza and COVID-19. This report describes CAPA cases diagnosed during the first wave in the biggest reference centre for severe COVID-19 in Mexico. OBJECTIVES: To describe the clinical, microbiological and radiological characteristics of patients with invasive pulmonary aspergillosis associated with critical COVID-19, as well as to describe the variables associated with mortality. METHODS: This retrospective study identified CAPA cases among individuals with COVID-19 and ARDS, hospitalised from 1 March 2020 to 31 March 2021. CAPA was defined according to ECMM/ISHAM consensus criteria. Prevalence was estimated. Clinical and microbiological characteristics including bacterial superinfections, antifungal susceptibility testing and outcomes were documented. RESULTS: Possible CAPA was diagnosed in 86 patients among 2080 individuals with severe COVID-19, representing 4.13% prevalence. All CAPA cases had a positive respiratory culture for Aspergillus species. Aspergillus fumigatus was the most frequent isolate (64%, n = 55/86). Seven isolates (9%, n = 7/80) were resistant to amphotericin B (A. fumigatus n = 5/55, 9%; A. niger, n = 2/7, 28%), two A. fumigatus isolates were resistant to itraconazole (3.6%, n = 2/55). Tracheal galactomannan values ranged between 1.2 and 4.05, while serum galactomannan was positive only in 11% (n = 3/26). Bacterial coinfection were documented in 46% (n = 40/86). Gram negatives were the most frequent cause (77%, n = 31/40 isolates), from which 13% (n = 4/31) were reported as multidrug-resistant bacteria. Mortality rate was 60% and worse prognosis was seen in older persons, high tracheal galactomannan index and high HbA1c level. CONCLUSIONS: One in 10 individuals with CAPA carry a resistant Aspergillus isolate and/or will be affected by a MDR bacteria. High mortality rates are seen in this population.

Covariation between the shape and mineralized tissues of the rib cross section in Homo sapiens, Pan troglodytes and Sts 14.

OBJECTIVES: Studying rib torsion is crucial for understanding the evolution of the hominid ribcage. Interestingly, there are variables of the rib cross section that could be associated with rib torsion and, consequently, with the morphology of the thorax. The aim of this research is to conduct a comparative study of the shape and mineralized tissues of the rib cross section in different hominids to test for significant differences and, if possible, associate them to different thoracic morphotypes. MATERIALS AND METHODS: The sample consists of the rib cross sections at the midshaft taken from 10 Homo sapiens and 10 Pan troglodytes adult individuals, as well as from A. africanus Sts 14. The shape of these rib cross sections was quantified using geometric morphometrics, while the mineralized tissues were evaluated using the compartmentalization index. Subsequently, covariation between both parameters was tested by a Spearman's ρ test, a permutation test and a linear regression. RESULTS: Generally, P. troglodytes individuals exhibit rib cross sections that are rounder and more mineralized compared to those of H. sapiens. However, the covariation between both parameters was only observed in typical ribs (levels 3-10). Although covariation was not found in the rib cross sections of Sts 14, their parameters are closer to P. troglodytes. DISCUSSION: On the one hand, the differences observed in the rib cross sections between H. sapiens and P. troglodytes might be related to different degrees of rib torsion and, consequently, to different thoracic 3D configurations. These findings can be functionally explained by considering their distinct modes of breathing and locomotion. On the other hand, although the rib cross sections belonging to Sts 14 are more similar to those of P. troglodytes, previous publications determined that their overall morphology is closer to modern humans. This discrepancy could reflect a diversity of post-cranial adaptations in Australopithecus.

Changes in pulmonary mechanics from supine to prone position measured through esophageal manometry in critically ill patients with COVID-19 severe acute respiratory distress syndrome.

OBJECTIVE: To describe changes in pulmonary mechanics when changing from supine position (SP) to prone position (PP) in mechanically ventilated (MV) patients with Acute Respiratory Distress Syndrome (ARDS) due to severe COVID-19. DESIGN: Retrospective cohort. SETTING: Intensive Care Unit of the National Institute of Respiratory Diseases (Mexico City). PATIENTS: COVID-19 patients on MV due to ARDS, with criteria for PP. INTERVENTION: Measurement of pulmonary mechanics in patients on SP to PP, using esophageal manometry. MAIN VARIABLES OF INTEREST: Changes in lung and thoracic wall mechanics in SP and PP RESULTS: Nineteen patients were included. Changes during first prone positioning were reported. Reductions in lung stress (10.6 vs 7.7, p=0.02), lung strain (0.74 vs 0.57, p=0.02), lung elastance (p=0.01), chest wall elastance (p=0.003) and relation of respiratory system elastances (p=0.001) were observed between patients when changing from SP to PP. No differences were observed in driving pressure (p=0.19) and transpulmonary pressure during inspiration (p=0.70). CONCLUSIONS: Changes in pulmonary mechanics were observed when patients were comparing values of supine position with measurements obtained 24h after prone positioning. Esophageal pressure monitoring may facilitate ventilator management despite patient positioning.

How accurate are medical CT and micro-CT techniques compared to classical histology when addressing the growth of the internal rib parameters?

Rib internal anatomy and its cross-sectional morphology inform about important biomechanical or even evolutionary aspects. Classic histological studies require destructive techniques that are reprehensible depending on the case (e.g., fossils). In the last years, non-destructive CT-based methods are contributing to complementing previous knowledge without damaging the bone. Even though these methods have been proved to be useful to understand adult variation, we do not know whether these methods are useful to cover ontogenetic variation. This work compares classical histological methods with medical- and micro-CT to quantify the amount of mineral area at the rib midshaft (% Min. Ar.), a proxy for bone density. We compared cross-sections from an ontogenetic sample of 14 human first ribs ranging from perinates to adults using a) classical histology, b) HD (9-17 microns) and SD micro-CT (90 microns), and c) standard medical-CT (0.66 mm). We found that all the CT-based methods provide a larger % Min. Ar. compared to the histological techniques, but the HD micro-CT resolution is the only capable of producing results comparable to classical histology (p > 0.01), with the SD micro-CT and the medical-CT producing statistically larger results compared to classical histology (p < 0.01). In addition, it is important to state that the resolution of a standard medical-CT is not high enough to differentiate between mineral and non-mineral areas of the cross-sections for perinates and infants. These results could have important implications to avoid (when necessary) destructive techniques that are not appropriate in the case of highly valuable specimens such as fossils.

Feeding intolerance during prolonged prone position in overweight and obese patients with severe COVID-19 / Intolerancia a la alimentación durante el prono prolongado en pacientes con COVID-19 y sobrepeso y obesidad

Objective: the aim of this study was to compare the incidence rate of feeding intolerance (FI) during supine (SP) or prone positioning (PP) in critically ill COVID-19 patients. Methods: this was a retrospective cohort study of critically ill patients with overweight or obesity who received enteral nutrition (EN) in prone or supine positioning continuously during the first five days of mechanical ventilation. Nutritional risk, anthropometric measurements and body composition were assessed at the first 24 hours upon Intensive Care Unit (ICU) admission. Biochemical and clinical variables (Sequential Organ Failure Assessment [SOFA], Acute Physiology and Chronic Health Evaluation II [APACHE II], Acute Kidney Injury [AKI] or comorbidities diagnosis) were collected. Pharmacotherapy (prokinetics, sedatives or neuromuscular blocking agents) and FI incidence (gastric residual volume [GRV] ≥ 200 ml or ≥ 500 ml, vomiting or diarrhea) were daily recorded. Constipation was defined as the absence of evacuation for five consecutive days. Results: eighty-two patients were included. Higher rate of prophylactic prokinetic prescription was observed in PP (42.8 vs 12.5 %, p = 0.002). GRV ≥ 200 in supine position was not different when compared to PP (p = 0.47). Vomiting episodes in supine compared to PP showed no difference between groups (15 % vs 24 %, p = 0.31). No differences in diarrhea events were detected (10 % vs 4.7 %, p = 0.36). Constipation was common in both groups (95 % vs 82 %, p = 0.06). Conclusion: FI during prone position was not different in comparison to supine position. Routinely use of prokinetics in continuous prone position may help to prevent FI incidence. Algorithm development is necessary for FI prevention and treatment so to avoid EN interruptions and adverse clinical outcomes. (AU)

Objetivo: comparar la incidencia de intolerancia a la alimentación entre pacientes críticos en posición supino (PS) o prono (PP). Métodos: cohorte retrospectiva de pacientes bajo ventilación mecánica por distrés respiratorio por COVID-19 y sobrepeso y obesidad, quienes recibieron nutrición enteral (NE) en PP o PS. Se evaluaron riesgo nutricional, mediciones antropométricas y composición corporal en las primeras 24 horas de ingreso a la Unidad de Cuidados Intensivos (UCI). Se recolectaron variables bioquímicas y clínicas (Sequential Organ Failure Assessment [SOFA], Acute Physiology and Chronic Health Evaluation II [APACHE II], lesión renal aguda y otras comorbilidades). Se registró el esquema de farmacoterapia prescrita durante los primeros cinco días (procinéticos, sedantes y bloqueadores neuromusculares). Se evaluó la incidencia de intolerancia a la alimentación, definida como la presencia de residuo gástrico (RG) ≥ 200 o ≥ 500 ml, vómito, diarrea o estreñimiento. Resultados: fueron incluidos 82 pacientes. Se observó una mayor prescripción de procinéticos como terapia profiláctica en PP (42,8 vs. 12,5 %, p = 0,002). No se observaron diferencias en RG ≥ 200 ml (p = 0,47) ni vómito (p = 0,31) entre ambos grupos. No se observaron diferencias en episodios de diarrea (10 % en PS vs. 4,7 % en PP, p = 0,36). El estreñimiento fue común en ambos grupos de estudio (95 vs. 82 %, p = 0,06). Conclusiones: la PP no se relaciona con una mayor incidencia de intolerancias a la alimentación. El uso rutinario de procinéticos durante la PP continua puede ayudar a prevenir la incidencia de dichas intolerancias. Es necesario el desarrollo de algoritmos para la prevención y tratamiento de las intolerancias a la alimentación para evitar interrupciones en la NE y desenlaces no deseables. (AU)

Feeding intolerance during prolonged prone position in overweight and obese patients with severe COVID-19.

Introduction: Objective: the aim of this study was to compare the incidence rate of feeding intolerance (FI) during supine (SP) or prone positioning (PP) in critically ill COVID-19 patients. Methods: this was a retrospective cohort study of critically ill patients with overweight or obesity who received enteral nutrition (EN) in prone or supine positioning continuously during the first five days of mechanical ventilation. Nutritional risk, anthropometric measurements and body composition were assessed at the first 24 hours upon Intensive Care Unit (ICU) admission. Biochemical and clinical variables (Sequential Organ Failure Assessment [SOFA], Acute Physiology and Chronic Health Evaluation II [APACHE II], Acute Kidney Injury [AKI] or comorbidities diagnosis) were collected. Pharmacotherapy (prokinetics, sedatives or neuromuscular blocking agents) and FI incidence (gastric residual volume [GRV] ≥ 200 ml or ≥ 500 ml, vomiting or diarrhea) were daily recorded. Constipation was defined as the absence of evacuation for five consecutive days. Results: eighty-two patients were included. Higher rate of prophylactic prokinetic prescription was observed in PP (42.8 vs 12.5 %, p = 0.002). GRV ≥ 200 in supine position was not different when compared to PP (p = 0.47). Vomiting episodes in supine compared to PP showed no difference between groups (15 % vs 24 %, p = 0.31). No differences in diarrhea events were detected (10 % vs 4.7 %, p = 0.36). Constipation was common in both groups (95 % vs 82 %, p = 0.06). Conclusion: FI during prone position was not different in comparison to supine position. Routinely use of prokinetics in continuous prone position may help to prevent FI incidence. Algorithm development is necessary for FI prevention and treatment so to avoid EN interruptions and adverse clinical outcomes.

Introducción: Objetivo: comparar la incidencia de intolerancia a la alimentación entre pacientes críticos en posición supino (PS) o prono (PP). Métodos: cohorte retrospectiva de pacientes bajo ventilación mecánica por distrés respiratorio por COVID-19 y sobrepeso y obesidad, quienes recibieron nutrición enteral (NE) en PP o PS. Se evaluaron riesgo nutricional, mediciones antropométricas y composición corporal en las primeras 24 horas de ingreso a la Unidad de Cuidados Intensivos (UCI). Se recolectaron variables bioquímicas y clínicas (Sequential Organ Failure Assessment [SOFA], Acute Physiology and Chronic Health Evaluation II [APACHE II], lesión renal aguda y otras comorbilidades). Se registró el esquema de farmacoterapia prescrita durante los primeros cinco días (procinéticos, sedantes y bloqueadores neuromusculares). Se evaluó la incidencia de intolerancia a la alimentación, definida como la presencia de residuo gástrico (RG) ≥ 200 o ≥ 500 ml, vómito, diarrea o estreñimiento. Resultados: fueron incluidos 82 pacientes. Se observó una mayor prescripción de procinéticos como terapia profiláctica en PP (42,8 vs. 12,5 %, p = 0,002). No se observaron diferencias en RG ≥ 200 ml (p = 0,47) ni vómito (p = 0,31) entre ambos grupos. No se observaron diferencias en episodios de diarrea (10 % en PS vs. 4,7 % en PP, p = 0,36). El estreñimiento fue común en ambos grupos de estudio (95 vs. 82 %, p = 0,06). Conclusiones: la PP no se relaciona con una mayor incidencia de intolerancias a la alimentación. El uso rutinario de procinéticos durante la PP continua puede ayudar a prevenir la incidencia de dichas intolerancias. Es necesario el desarrollo de algoritmos para la prevención y tratamiento de las intolerancias a la alimentación para evitar interrupciones en la NE y desenlaces no deseables.

Low phase angle is associated with 60-day mortality in critically ill patients with COVID-19.

BACKGROUND: Malnutrition status, body composition indicators, and bioelectrical impedance analysis (BIA) parameters have been associated with increased risk of death in several pathologies. The aim of this study was to describe the associations between phase angle (PhA) indicators obtained by BIA with length of hospital stay, days on mechanical ventilation, and 60-day mortality in critically ill patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: This is a prospective cohort of mechanically ventilated patients with coronavirus disease 2019 (COVID-19). We assessed nutrition risk and body composition with BIA within 48 h from intensive care unit admission. Logistic and linear regression models were used to analyze the association between variables and clinical outcomes. Survival analysis by PhA value was performed using Kaplan-Meier curves. RESULTS: Sixty-seven patients were included. PhA (odds ratio [OR], 0.36; P = .002), standardized PhA (SPA) (OR, 0.45; P = .001), and extracellular water/total body water ratio (OR, 3.25; P = .002) were significant predictors of 60-day mortality. PhA <3.85° in females and <5.25° in males showed good and fair discrimination, respectively, for mortality prediction. Using cutoff values, low PhA was associated with a significantly increased risk of 60-day mortality (hazard ratio, 3.08; 95% CI, 1.12-8.41; P = .02). No association was detected for SPA. CONCLUSION: Low PhA values could be a predictor of 60-day mortality in critically ill patients with COVID-19. This biological marker could be incorporated as part of nutrition and mortality risk assessment in this population.

Evaluation of hormonal and metabolic factors related to depression in reproductive age women / Evaluación de factores hormonales y metabólicos relacionados con la depresión en mujeres en edad fértil

Abstract Introduction Major depressive disorder (MDD) is a prevalent disease affecting women more than men worldwide. Various factors are involved in the genesis of depression, including hormones such as testosterone and certain metabolic factors Objective To evaluate hormone levels and metabolic variables in women with major depression and healthy controls. Method A cross-sectional, comparative analytical study was conducted in 40 participants, 23 patients with an MDD diagnosis and 17 controls, all of women in reproductive age between the ages of 18 and 45. Sociodemographic variables, hormonal profile, and metabolic variables were assessed and the 17-item Hamilton Depression Scale was used to evaluate depressive symptoms. Results No statistically significant differences were observed between the groups in the hormonal and metabolic variables explored. Nevertheless, it was observed that the lower the testosterone levels and the higher the serum glucose levels, the more intense depressive symptoms were. Discussion and conclusion Testosterone is associated with a lower depressive symptoms score on the Hamilton Depression scale, suggesting a potential antidepressant effect, whereas high glucose levels are associated with a higher score on this scale. We believe that the measurement of hormonal and metabolic variables in women can contribute to a better understanding of the pathophysiology of depression.

Resumen Introducción El trastorno depresivo mayor (TDM) es una enfermedad prevalente a nivel mundial, que afecta más a mujeres que a hombres. En la génesis de la depresión se consideran diversos factores, entre ellos algunas hormonas como la testosterona y ciertos factores metabólicos Objetivo Evaluar los niveles de hormonas y variables metabólicas en mujeres con depresión mayor y controles sanas. Método Se realizó un estudio transversal, comparativo y analítico en 40 participantes, 23 pacientes con diagnóstico de TDM y 17 controles, todas ellas mujeres de 18 a 45 años en periodo reproductivo. Se evaluaron variables sociodemográficas, perfil hormonal y variables metabólicas, y se aplicó la Escala de Depresión de Hamilton de 17 reactivos para evaluar los síntomas depresivos. Resultados No se observaron diferencias estadísticamente significativas entre los grupos en las variables hormonales y metabólicas exploradas. Sin embargo, se observó que, cuanto menores eran los niveles de testosterona y mayores los de glucosa sérica, los síntomas depresivos eran de mayor intensidad. Discusión y conclusión La testosterona se asocia con un menor puntaje de síntomas depresivos en la Escala Hamilton, lo que sugiriere un potencial efecto antidepresivo, mientras que los niveles altos de glucosa se asocian con un mayor puntaje en dicha escala. Consideramos que la medición de variables hormonales y metabólicas en la mujer puede contribuir a mejorar el conocimiento de la fisiopatología de la depresión.

External and internal ontogenetic changes in the first rib.

OBJECTIVES: First ribs bear information about thorax morphology and are usually well preserved, compared to other ribs, in bone/fossil samples. Several studies have addressed ontogeny of the first rib by studying changes in bone microanatomy and rib morphology separately, but no studies have combined both approaches to study how internal and external changes covary during ontogeny. The aim of this project is to fill this gap in our knowledge. MATERIALS AND METHODS: We applied 3D geometric morphometrics of sliding semilandmarks to 14 first ribs of Homo sapiens to quantify rib curvature and mid-shaft cross-section outline. Ontogenetic variation was addressed throughout a principal component analysis (PCA). Additionally, we made histological sections at the mid-shaft of the same ribs and studied tissue matrix composition and compartmentalization. Finally, we performed partial least squares (PLS) and regression analyses to study covariation between rib morphology and compartmentalization variables. RESULTS: PCA shows that first ribs increase their curvature over the course of ontogeny and the rib midshaft becomes less rounded during ontogeny. In addition, the sternal end becomes more medially oriented during ontogeny and the relative head-tubercle distance becomes longer. Compartmentalization shows a decrease in the area occupied by mineralized tissues and an increase in the area occupied by non-mineralized tissues over the course of ontogeny, which covaries with mid-shaft cross-section shape. CONCLUSIONS: Our results show detailed variation in rib morphology along with histological changes in bone tissue compartmentalization and, for the first time, the correlation between the two. This could be related to muscle attachments on the 1st rib and also to changes in breathing mode, from diaphragmatic in perinatals to pulmonary in adults, which could also have implications for understanding thorax evolution.

Geometric morphometrics reveals restrictions on the shape of the female os coxae.

The methodology for sex determination in human skeletal remains depends on the different bone morphologies presented by men and women. Due to their direct implications in reproduction, the whole pelvis, particularly the os coxae, shows different characteristics in either sex. The sacrum and the os coxae constitute the birth canal. In this research study, the os coxae shape is analyzed using geometric morphometrics, providing information on morphology, regardless of size or any other factor beyond the geometry itself. A total of 46 adult ossa coxae from a Spanish archaeological collection were studied using geometric morphometrics. The results show that there is a restriction on the shape of female os coxae. In contrast, male os coxae presents a greater range of variation. The biological reason for this difference is the obstetrical dilemma; a concept defined as the anatomical conflict between bipedalism and the full-term birth of a neonate whose large head requires greater dimensions in the pelvic cavity. Our experimental data reinforce the validity of the obstetrical dilemma as source of the restriction on the shape of female ossa coxae. Additionally, according to the results obtained, size itself does not represent a condition for belonging to one sex or another.

Multidisciplinary characterization of the long-bone cortex growth patterns through sheep's ontogeny.

Bone researches have studied extant and extinct taxa extensively trying to disclose a complete view of the complex structural and chemical transformations that model and remodel the macro and microstructure of bone during growth. However, to approach bone growth variations is not an easy task, and many aspects related with histological transformations during ontogeny remain unresolved. In the present study, we conduct a holistic approach using different techniques (polarized microscopy, Raman spectroscopy and X-ray diffraction) to examine the histomorphological and histochemical variations in the cortical bone of sheep specimens from intrauterine to adult stages, using environmentally controlled specimens from the same species. Our results suggest that during sheep bone development, the most important morphological (shape and size) and chemical transformations in the cortical bone occur during the first weeks of life; synchronized but dissimilar variations are established in the forelimb and hind limb cortical bone; and the patterns of bone tissue maturation in both extremities are differentiated in the adult stage. All of these results indicate that standardized histological models are useful not only for evaluating many aspects of normal bone growth but also to understand other important influences on the bones, such as pathologies that remain unknown.

An approach to the histomorphological and histochemical variations of the humerus cortical bone through human ontogeny.

For many years, clinical and non-clinical investigations have investigated cortical bone structure in an attempt to address questions related to normal bone development, mineralisation, pathologies and even evolutionary trends in our lineage (adaptations). Research in the fields of medicine, materials science, physical anthropology, palaeontology, and even archaeobiology has contributed interesting data. However, many questions remain regarding the histomorphological and histochemical variations in human cortical bone during different stages of life. In the present work, we describe a study of long bone cortex transformations during ontogeny. We analysed cross-sections of 15 human humeri histomorphologically and histochemically from perinatal to adult age, marking and quantifying the spatial distribution of bone tissue types using GIS software and analysing the mineral composition and crystallinity of the mineralised cortex using Raman spectroscopy and X-ray diffraction. Our results allowed us to propose that human cortical bone undergoes three main 'events' through ontogeny that critically change the proportions and structure of the cortex. In early development, bone is not well mineralised and proportionally presents a wide cortex that narrows through the end of childhood. Before reaching complete maturity, the bone mineral area increases, allowing the bone to nearly reach the adult size. The medullary cavity is reduced, and the mineral areas have a highly ordered crystalline structure. The last event occurs in adulthood, when the 'oldest' individuals present a reduced mineralised area, with increasing non-mineralised cavities (including the medullary cavity) and reduced crystalline organisation.

Mapping human long bone compartmentalisation during ontogeny: a new methodological approach.

Throughout ontogeny, human bones undergo differentiation in terms of shape, size and tissue type; this is a complex scenario in which the variations in the tissue compartmentalisation of the cortical bone are still poorly understood. Currently, compartmentalisation is studied using methodologies that oversimplify the bone tissue complexity. Here, we present a new methodological approach that integrates a histological description and a mineral content analysis to study the compartmentalisation of the whole mineralised and non-mineralised tissues (i.e., spatial distribution in long bone sections). This new methodology, based on Geographical Information System (GIS) software, allows us to draw areas of interest (i.e., tracing vectorial shapes which are quantifiable) in raw images that are extracted from microscope and compared them spatially in a semi-automatic and quantitative fashion. As an example of our methodology, we have studied the tibiae from individuals with different age at death (infant, juvenile and adult). The tibia's cortical bone presents a well-formed fibrolamellar bone, in which remodelling is clearly evidenced from early ontogeny, and we discuss the existence of "lines of arrested growth". Concurrent with the histological variation, Raman and FT-IR spectroscopy analyses corroborate that the mineral content in the cortical bone changes differentially. The anterior portion of the tibia remains highly pierced and is less crystalline than the rest of the cortex during growth, which is evidence of more active and continuous remodelling. Finally, while porosity and other "non-mineralised cavities" are largely modified, the mineralised portion and the marrow cavity size persist proportionally during ontogeny.

Atención hospitalaria de la leishmaniosis tegumentaria americana en los miembros inferiores / Hospital care of American tegumentary leishmaniasis in the lower limbs

La leishmaniosis tegumentaria americana (LTA) como enfermedad endémica crónica continúa afectando a la población del medio rural venezolano, ocasionándole morbilidad y limitaciones laborales. Mediantes la descripción de casos clínicos se evaluaron 38 pacientes con LTA que recibieron atención hospitalaria por úlceras leishmánica en miembros inferiores. De los pacientes descriptos 63% eran niños, 84% procedía del Estado Miranda, 66% tenía una lesión ulcerosa única, 45% recibió cefadroxilo previo al tratamiento antiparasitario específico y el 24% había recibio inmunoterapia previa para la enfermedad. Treinta y siete pacientes (97%) recibieron antimoniato de meglumina en series terapéuticas de aiez días y uno anfoterecina B, por contraindicación cardiovascular para el uso del antimonial. Todos presentaron re-epitelización adecuada de sus lesiones, por lo que el antimoniato de meglumina demuestra una vez más su utilidad en la terapéutica de esta zoonosis parasitaria.

American tequmentary leishmaniasis (ATL) endemic chronic disease continues to affect the population of rural Venezuela, causing morbidity and labor constraints. By the description of clinical were evaluated 38 patients with ATL who received hospital care for leishmanial ulcers in lower limbs. Sixty-three percent of the patients were children, 84% came from Miranda state, 66% had a unique ulcerated lesion, 45% received cefadroxil prior to parasite specific treatment and 24% had received immunotherapy for the diseaes. Thirtyseven patients (97%) received meglumine antimoniate in series of ten days and one patient received anfotericine B, due to cardiovascular contraindication for the use of the antimonial. All ulcers healed. The antimoniate of meglumine demonstrates once again its usefulness in the treatment of this parasitic zoonosis.

Bordetella pertussis: caracterización epidemiológica y diagnóstico / Bordetella pertusis: epidemiologic characterization and diagnosis

La tos ferina es una enfermedad transmisible e inmunoprevenible que actualmente esta resurgiendo en países del primer mundo. La investigación tuvo como propósito determinar la circulación de Bordetella, pertussis en pacientes menores de 1 año, en el servicio de pediatría del Hospital Universitario de Caracas entre junio 2001- noviembre 2002. Se incluyeron pacientes menores de 1 año con síntomas sospechosos de tos ferina según la Organización Mundial de la Salud (OMS). Se realizó encuesta epidemiológica y clínica, cultivo de secreción nasofaríngea y serológica para Ig M. Durante 17 meses se identificaron 66 casos sospechosos de tos ferina, 35 fueron incluidos. Hubo confirmación bacteriológica en 8.6%, la negatividad del cultivo se correlacionó 100% con serología. Los confirmados tenían menos de 3 meses de edad, con antecedentes de contacto, ausencia de inmunización y clínica de tos paroxística, cianosis y vómito post-tusígeno. Se confirma la circulación de Bordetella pertussis y se establecen bases para el inicio el modelo del proyecto de vigilancia epidemiológica.

Estudio multicéntrico y comparativo de la eficacia y seguridad de cefprozil 30 mg/kg/día vs cefprozil 50 mg/kg/día en otitis media aguda (OMA) y sinusitis aguda (SA) en pacientes pediátricos / Study multicentric and comparative of the efficacy and segurity of cefprozil 30 mg/kg/day vs cefprozil 50 mg/kg/day in otitis media acute (OMA) and sinusitis acute (SA) in patients pediatric

La resistencia bacteriana a antibióticos causa fracaso terapéutico y una de sus causas es la dosificación subterapéutica de los mismos. Por ello, con base en su eficacia y seguridad, se valoran dos regímenes diferentes de Cefprozil (30 o 50 mg/kg/día) para el tratamiento de OMA y SA en niños. Para ello, se reclutaron a 277 niños menores de 12 años, 193 de los cuales recibieron 30 mg/kg/día de Cefprozil y el resto (84) 50 mg/kg/día del mismo antibiótico. La eficacia, definida por curación o mejoría, fue de 81 por ciento en el primer grupo y de 95 por ciento en el segundo en OMA. La eficacia de la dosis de 50 mg/kg/día de Cefprozil fue estadísticamente superior a la observada con 30 mg/kg/día, cuya significancia fue de p=0,01 por X², resultados superiores a los observados en estudios internacionales con otros medicamentos comúnmente utilizados para tratar estas patologías