Effect of Plate Configuration in the Primary Stability of Osteotomies and Biological Reconstructions of Femoral Defects: Finite-Element Study.

BACKGROUND/OBJECTIVE: Osteosynthesis is an alternative treatment for stabilizing femur-bone traumas. The initial stability of the fixation systems is one of the biomechanical parameters affecting implant failure and bone union, especially in surgeries of intercalary reconstructions after the removal of bone tumors. This study aimed to investigate the initial biomechanical effect of using one or two osteosynthesis plate configurations for femoral fixation and the effect of fastening the allograft to the osteosynthesis plate in the case of femoral allograft reconstructions. METHODS: Three finite-element models of a femur with three different fixation conditions for a transverse osteotomy in the middle of the diaphysis, i.e., using one and two osteosynthesis plates and an intercalary allograft, were constructed. An eight-hole compression plate and a six-hole second plate were used to simulate osteosynthesis plates. The plate screws were tightened previously to the loading, and the tightening sequences simulate the bolt-tightening procedure in a surgical environment. The models were imported into the ADINA System for nonlinear analysis, using compression loads applied over the femur head. RESULTS: Models with the dual fixation systems had the most outstanding compression stiffness. The femur head movement in the dual plate system was 24.8% smaller than in the single plate system. A statistical analysis of a region of interest (VOI) placed in the femur diaphysis showed that the biomechanical effect of using the dual plate system is smaller in the osteotomy region than at the femur head, e.g., a displacement average decrease of only 5% between the two systems, while the maximum value decreases by 26.8%. The allograft fixation to the second osteosynthesis plate leads to an improvement in the system stability. CONCLUSIONS: The results presented in this work show that including the bolt analysis in the femoral diaphysis osteotomy fixation will allow for capturing the nonlinear behavior of the osteotomy region more realistically. The stability of the intercalary reconstruction of the femoral diaphysis was higher when the allograft was fastened to the second osteosynthesis plate.

Forensic Professionals' Stress Inventory (FPSI): Development and psychometric properties.

Professionals in the justice system are particularly susceptible to occupational stress and burnout due to factors intrinsic to their profession. The Forensic Professional's Stress Inventory (FPSI) was designed to assess stress and psychological distress specifically in justice system professionals. A preliminary 41-item scale was administered to a sample of 690 forensic professionals (i.e., judges, lawyers, and attorneys). Exploratory factor analysis, exploratory structural equation modeling, and confirmatory factor analysis were conducted to find the most interpretable and parsimonious factor solution for FPSI. The 25-item bifactor model (with four first-order factors) demonstrated the most adequate fit to the data. Overall, FPSI revealed adequate psychometric properties and would be a useful instrument for assessing psychological strain and stress in forensic professionals.

Delayed postoperative reactions to metamizole: a diagnostic challenge.

Summary: Background. Metamizole, a non-steroidal anti-inflammatory drug from the pyrazolone group, is a frequent cause of immediate hypersensitivity reactions and, more rarely, of delayed drug hypersensitivity reactions. Due to its favorable pharmacokinetic characteristics, metamizole is widely used in the postoperative period for pain control. Methods. Retrospective study of patients referred for allergological study between January 2012 and June2022 for postoperative hypersensitivity reactions. Clinical and diagnostic data were collected through review of patients' medical records. Twenty patients with postoperative hypersensitivity reactions were referred, of which 10 presented delayed reactions. We analyzed the results of skin prick, intradermal and patch tests performed with an intravenous metamizole solution as well as provocation tests performed with metamizole and acetylsalicylic acid. Cross-reactivity to non-steroidal anti-inflammatory drugs was excluded by confirmation of clinical tolerance to non-steroidal anti-inflammatory drugs or by acetylsalicylic acid provocation test. Results. In 7 of the 10 patients a delayed reaction to metamizole was diagnosed. These reactions were characterized as maculopapular exanthema, occurring in multiple postoperative settings. Skin tests were negative, except in one patient with late mild erythema in the ipsilateral upper limb and no reaction at the site of intradermal injection. Delayed hypersensitivity was demonstrated by late positive metamizole provocation tests. Conclusions. This study demonstrated that for a correct diagnosis a high degree of suspicion about possible delayed hypersensitivity drug reactions to metamizole in the postoperative setting is needed. In the investigation, provocation test with metamizole was decisive for diagnostic confirmation.

Clinical experience of a specialized urticaria outpatient clinic from a Portuguese UCARE.

Summary: Background. Chronic urticaria (CU) is a frequent disease, with a prevalence of at least 1%. It is characterized by pruritic wheals, angioedema or both for a period longer than 6 weeks. Objective. Identify the demographic, clinical, laboratory and therapeutic profile of patients treated in a Portuguese Urticaria Center of Reference and Excellence (UCARE) and compare it with international series. Methods. Retrospective analysis of database of patients observed in a specialized urticaria outpatient clinic, from January 2017 through September 2019, of a UCARE center in Portugal. Demographic and clinical features, laboratory findings and pharmacological treatment were obtained from the records. Descriptive analyses were performed for all variables. Chi square and fisher's exact tests were applied to analyze the independence of variables and the fit of distribution. P less than 0.05 was considered significant. Results. During this period, 477 patients were observed, of whom 429 (90%) were diagnosed with chronic urticaria. Mean age (years) at the onset of symptoms was 43.7 (standard deviation (SD) 17.6, range 6-88) and at diagnosis 46.7 (SD 17.8, range 6-88) resulting in an average diagnostic delay of 3 years (range 0-25). Median follow-up period since first attendance in the specialized outpatient clinic was 1.7 years (interquartile range (IQR) 0.79, range 0.1-2.75) . Concerning the whole group of CU patients, 347 (81%) had chronic spontaneous urticaria (CSU) - 79% female, 39 (9%) had isolated chronic inducible urticaria (CIndU) and 43 (10%) had CSU with CIndU. Autologous serum skin test (ASST) was done in 76 patients (positive in 24 (32%)) and basophil activation test (BAT) was done in 38 (positive in 13 (34%)). At the moment of study, 204 (48%) of CU patients were medicated with a second-generation H1-antihistamine (sgAH) daily (first-line therapy), 99 (23%) with sgAH up to four times the standard dose (second-line therapy) and 126 (29%) with omalizumab (third-line therapy). Additionally, 7 (2%) patients were completing a short course of systemic corticosteroids for management of disease exacerbation. Disease control was achieved in 316 of CSU patients (81%). Conclusions. Referral to a specialized urticaria outpatient clinic is important for a proper assessment of the disease and adequately symptom control.

Development of 3D-QSAR and pharmacophoric models to design new anti-Trypanosoma cruzi agents based on 2-aryloxynaphthoquinone scaffold.

In this work we have collected a set of 30 trypanosomicidal naphthoquinones and developed pharmacophoric and 3D-QSAR models as tools for the design of new potential anti-Chagasic compounds. Firstly, qualitative information was obtained from SAR and pharmacophoric models identifying some fragments around the 2-aryloxynaphthoquinone scaffold important for the antiparasitic activity. Then, 3D-QSAR CoMFA and CoMSIA models were developed. The models showed adequate statistical parameters where the steric, electrostatic, and hydrophobic features explain the trypanosomicidal effect. Therefore, to validate our models, we carried out the design, synthesis, and biological evaluation on T. cruzi epimastigotes of five new compounds (33a-e). According to CoMFA model, three out of five compounds showed pIC50 values within one logarithmic unit of deviation. The two compounds that did not fit the predictions were those with high lipophilicity, which agreed with the SAR and pharmacophore models. Docking and molecular dynamic studies were performed on T. cruzi trypanothione reductase, in a proposed binding site for this type of naphthoquinone. Interestingly, 33a-e showed the same interaction pattern as a naphthoquinone inhibitor (2). Finally, predicted drug-likeness properties indicated that 33a-e have optimal oral bioavailability. Thus, this study provides new in silico models for obtaining novel trypanosomicidal compounds.

Predictions on multi-class terminal ballistics datasets using conditional Generative Adversarial Networks.

Ballistic impacts are a primary risk in both civil and military defence applications, where successfully predicting the dynamic response of a material or structure to impact crucial to the design of safe and fit-for-purpose protective structures. This study proposes a conditional Generative Adversarial Network (cGAN) architecture that can learn directly from available ballistic data and can be conditioned on additional information, such as class labels, to govern its output. A single Multi-Layer Perceptron (MLP) cGAN architecture is trained on a multi-class ballistic training set consisting of 10 classes labelled 0-9 where each class refers to a ballistic curve with a different ballistic limit velocity, vbl. A total of 5 models are trained on datasets consisting of 5, 10, 15, 20 and 25 samples within each class. For integer class labels 0-9, all cGAN models successfully predict the vbl with a maximum error of 4.12%. Additionally, for non-integer class labels between 0-9 the vbl predictions are similar despite not explicitly appearing in the training set. Moreover, each cGAN model is challenged to generate new samples for class labels that exist beyond the scope of the training set for class labels between 9-20. Four of the models predict the vbl with an error of less than 1.5% in all cases. This study showcases how a cGAN model can learn directly from a multi-class ballistic dataset and generate additional samples representative of that data for classes that do not appear explicitly in the training set.

Urticaria por frío. Caracterización de la población de una clínica ambulatoria especializada en urticaria / Cold Urticaria. Characterizing the Population From an Urticaria Outpatient Clinic

Introducción La urticaria por frío (UF) es un tipo de urticaria crónica inducible (CIndU) donde aparecen ronchas pruriginosas recurrentes y/o angioedema tras la exposición a estímulos fríos. Aunque normalmente solo afecta a áreas expuestas, pueden producirse reacciones sistémicas. Nuestro objetivo es caracterizar los casos de UF de nuestro hospital. Material y métodos Estudio retrospectivo de casos de UF seguidos en nuestra consulta de urticaria en Portugal hasta octubre de 2020. Resultados Se incluyeron 52 pacientes, de ellos 40 mujeres. La edad media fue de 35años. En 19 pacientes, los síntomas comenzaron antes de los 18años de edad. La UF se clasificó como adquirida en todos los pacientes. Las pruebas de provocación por frío fueron negativas en 9 pacientes, clasificados como UF atípica. No se encontraron diferencias con respecto al inicio en edad pediátrica o adulta. Más de la mitad de los pacientes (52%) tenían una UF localizada. A pesar de no ser estadísticamente significativa, la temperatura umbral evaluada con TempTest® 4.0 fue más alta y el tiempo de estimulación más corto en los pacientes con síntomas más graves. Todos los pacientes fueron tratados con antihistamínicos y uno con omalizumab. Los pacientes controlados con dosis estándar de antihistamínicos tenían temperatura umbral más baja que los que necesitaban dosis más altas (p<0,01). Conclusión La UF es una enfermedad heterogénea que, en algunos casos, puede poner en peligro la vida del paciente. Las pruebas de provocación con frío pueden ser útiles en el manejo e identificación de grupos de gravedad (AU)

Introduction Cold Urticaria (ColdU) is a type of chronic inducible urticaria (CIndU) where recurrent pruritic wheals and/or angioedema occur after exposure to cold stimulus. Although it usually only affects exposed areas, systemic reactions can occur in severe cases. In this study, we seek to characterize the ColdU cases within our Centre's population of patients. Material and methods Retrospective study based on clinical files of patients diagnosed with ColdU followed in an urticaria outpatient clinic in Portugal prior to October 2020. Results We included 52 patients total (40 women) with median age of 35 years, 19 patients with symptom onset before 18 years-old. ColdU was classified as acquired in all patients. Cold provocation tests were negative in 9 patients and these were classified as atypical ColdU. No significant differences were found between those with pediatric or adult onset of disease. Most of the patients had a localized form of the disease (52%). Despite not being statistically significant, it was found that patient's temperature threshold, assessed with TempTest® 4.0, was higher and stimulation time was shorter in more severe groups. All patients were treated with non-sedating antihistamines (daily or on-demand), finding that those controlled with standard dosages had lower temperature thresholds than those needing higher dosages (p<0.01). One patient was under treatment with omalizumab. Conclusion ColdU is an heterogenous disease that can have life-threatening event consequences. Cold provocation tests and threshold assessment can be an important tool in the management treatment and in identifying severity groups (AU)

Cold Urticaria. Characterizing the population from an urticaria outpatient clinic.

INTRODUCTION: Cold Urticaria (ColdU) is a type of chronic inducible urticaria (CIndU) where recurrent pruritic wheals and/or angioedema occur after exposure to cold stimulus. Although it usually only affects exposed areas, systemic reactions can occur in severe cases. In this study, we seek to characterize the ColdU cases within our Centre's population of patients. MATERIAL AND METHODS: Retrospective study based on clinical files of patients diagnosed with ColdU followed in an urticaria outpatient clinic in Portugal prior to October 2020. RESULTS: We included 52 patients total (40 women) with median age of 35 years, 19 patients with symptom onset before 18 years-old. ColdU was classified as acquired in all patients. Cold provocation tests were negative in 9 patients and these were classified as atypical ColdU. No significant differences were found between those with pediatric or adult onset of disease. Most of the patients had a localized form of the disease (52%). Despite not being statistically significant, it was found that patient's temperature threshold, assessed with TempTest® 4.0, was higher and stimulation time was shorter in more severe groups. All patients were treated with non-sedating antihistamines (daily or on-demand), finding that those controlled with standard dosages had lower temperature thresholds than those needing higher dosages (p < 0.01). One patient was under treatment with omalizumab. CONCLUSION: ColdU is an heterogenous disease that can have life-threatening event consequences. Cold provocation tests and threshold assessment can be an important tool in the management treatment and in identifying severity groups.

Cold Urticaria. Characterizing the Population From an Urticaria Outpatient Clinic. / Urticaria por frío. Caracterización de la población de una clínica ambulatoria especializada en urticaria.

INTRODUCTION: Cold Urticaria (ColdU) is a type of chronic inducible urticaria (CIndU) where recurrent pruritic wheals and/or angioedema occur after exposure to cold stimulus. Although it usually only affects exposed areas, systemic reactions can occur in severe cases. In this study, we seek to characterize the ColdU cases within our Centre's population of patients. MATERIAL AND METHODS: Retrospective study based on clinical files of patients diagnosed with ColdU followed in an urticaria outpatient clinic in Portugal prior to October 2020. RESULTS: We included 52 patients total (40 women) with median age of 35 years, 19 patients with symptom onset before 18 years-old. ColdU was classified as acquired in all patients. Cold provocation tests were negative in 9 patients and these were classified as atypical ColdU. No significant differences were found between those with pediatric or adult onset of disease. Most of the patients had a localized form of the disease (52%). Despite not being statistically significant, it was found that patient's temperature threshold, assessed with TempTest® 4.0, was higher and stimulation time was shorter in more severe groups. All patients were treated with non-sedating antihistamines (daily or on-demand), finding that those controlled with standard dosages had lower temperature thresholds than those needing higher dosages (p<0.01). One patient was under treatment with omalizumab. CONCLUSION: ColdU is an heterogenous disease that can have life-threatening event consequences. Cold provocation tests and threshold assessment can be an important tool in the management treatment and in identifying severity groups.

Hábitos tabágicos nos enfermeiros de uma ULS da Região Centro de Portugal / Smoking habits in nurses at a ULS in the Central Region of Portugal

O tabagismo é uma problemática transversal a toda a população, sendo considerado um grave problema de saúde pública. Diversos estudos demonstram uma elevada prevalência de consumidores de tabaco entre profissionais de saúde. Estes, em particular os enfermeiros, têm na luta contra os hábitos tabágicos um papel crucial. A este grupo profissional também poderá estar associado níveis de stresse ocupacional elevados, podendo o consumo de tabaco ser um dos fatores associados ao alívio do stresse. Pretendeu-se com este estudo conhecer os hábitos tabágicos dos enfermeiros de uma ULS da região centro de Portugal, avaliar o grau de dependência à nicotina e a motivação para a cessação tabágica, averiguar a existência de relação entre as características sociodemográficas e do contexto laboral com o grau de dependência à nicotina e a motivação para a cessação tabágica, verificar se existe relação entre as características sociodemográficas e do contexto laboral com ser ou não fumador, avaliar o stresse ocupacional dos enfermeiros e averiguar a existência de relação entre o stresse ocupacional nos enfermeiros e o grau de dependência à nicotina e a motivação para a cessação tabágica. O estudo apoiou-se numa metodologia quantitativa, descritiva e transversal. A população alvo foram todos os enfermeiros de uma ULS da região centro de Portugal. Utilizou-se um protocolo de colheita de dados distribuído a todos os enfermeiros que trabalhavam nas unidades de saúde em estudo, via correio eletrónico institucional, que esteve disponível online entre 15 de julho de 2017 a 5 de março de 2018. Dos 208 respondentes, 71,6% eram do sexo feminino com média idade de 40,5 anos, sendo que 19% referiu ter fumado pelo menos um cigarro na última semana. Os fumadores iniciaram o consumo, em média, aos 18,5 anos e consumiam há 17,5 anos. Dos fumadores, 52,5% apresentava um grau de dependência à nicotina muito baixa e 95% manifestou baixa motivação. Concluiu-se que uma menor motivação para a cessação tabágica está associada um maior grau de dependência à nicotina. Os resultados indicaram que os fumadores que vivem ou convivem com fumadores têm menor motivação para a cessação tabágica. A maioria dos enfermeiros (75%) manifestou moderado a elevado stresse ocupacional, nas dimensões lidar com utentes, excesso de trabalho e carreira e renumeração. Os resultados indicaram que à medida que o nível de stresse aumentava o grau de dependência à nicotina e o consumo de tabaco também aumentavam, mas sem evidência estatística que a motivação para a cessação tabágica estivesse associada aos níveis de stresse. Este estudo permitiu conhecer a realidade dos hábitos tabágicos e do stresse ocupacional da comunidade de enfermeiros em estudo. Tal possibilita a otimização de estratégias/atividades para mitigar a problemática do tabagismo/stresse ocupacional melhorando a qualidade da saúde dos enfermeiros e da comunidade, com ganhos em saúde, indo ao encontro das competências descritas pela OE para o Enfermeiro Especialista em Enfermagem Comunitária e de Saúde Pública.

Tobacco smoking affects the general population and is considered a serious public health problem. Several studies have shown a high prevalence of tobacco users among health professionals. Being that, the nurses have in the fight against smoking habits a crucial role. This professional group may also be associated with high levels of occupational stress and smoking could be one of the factors associated with stress relief. The purpose of this study was to know the smoking habits of nurses from an ULS in the central region of Portugal, assess the degree of nicotine dependence and the motivation for smoking cessation, investigate the existence of a relationship between the sociodemographic characteristics and the work context with the degree of nicotine dependence and the motivation for smoking cessation, to verify if there is a relation between the sociodemographic characteristics and the work context with or without smoking, assess the occupational stress of nurses and to the existence of a relationship between occupational stress in nurses and the degree of nicotine dependence and the motivation for smoking cessation. The study was quantitative, descriptive and cross methodology. The target population were all nurses from an ULS in the central region of Portugal, a data collection protocol was used and distributed by institutional email to all nurses working in the health units concerned and was available online between July 15, 2017 to March 5, 2018. From 208 respondents, 71.6% were female with an average age of 40.5 years, and 19% reported having smoked at least one cigarette in the last week. Smokers began consumption, on average, at 18.5 years and 17.5 years for consumption time. From the smokers, 52.5% had a very low degree of nicotine dependence and 95% had low motivation. It has been concluded that a lower motivation for smoking cessation is associated with a greater degree of nicotine dependence. The results indicated that smokers who live or coexist with smokers have lower motivation for smoking cessation. The majority of nurses (75%) showed moderate to severe occupational stress, in the dimensions dealing with users, overwork and career and renumbering. The results indicated that as the stress level increased the degree of nicotine dependence and tobacco consumption also increased, but without statistical evidence that the motivation for smoking cessation were associated with stress levels. This study allowed to know the reality of the smoking habits and the occupational stress of the community of nurses under study. Such results enable the optimization of strategies/activities that can mitigate the problem of smoking/occupational stress improving the quality of health of nurses and the community, with health gains, meeting the competencies described by OE for the Nurse Specialist in Community Nursing and Public Health.

FE and experimental study on how the cortex material properties of synthetic femurs affect strain levels.

The primary aim of this work was to validate the "numerical" cortex material properties (transversely isotropic) of synthetic femurs and to evaluate how the strain level of the cancellous bone can be affected by the FE modeling of the material's behavior. Sensitivity analysis was performed to find out if the parameters of the cortex material affect global strain results more than the Polyurethane (PU) foam used to simulate cancellous bone. Standard 4th generation composite femurs were made with 0.32g/cm3 solid PU foam to model healthy cancellous bone, while 0.2g/cm3 cellular PU was used to model unhealthy cancellous bone. Longitudinal and transversal Young's moduli of cortical bone were defined according the manufacturer data, while shear modulus and Poisson's ratios were defined from the literature. All femurs were instrumented with rosette strain gauges and loaded according to ISO7206 standards, simulating a one-legged stance. The experimental results were then compared with those from finite element analysis. When cortical bone was modelled as transversely isotropic, an overall FE/experimental error of 11% was obtained. However, with isotropic material the error rose to 20%. Strain field distributions predicted inside the two bone models were similar, but the strain state of a healthy cancellous bone was much more a compression state than that of unhealthy bone, the compression state decreased about 90%. Strain magnitudes show that average strain-levels of cancellous bone can be significantly affected by the properties of the cortical bone material and, therefore, simulations of femur-implanted systems must account for the composite behavior of the cortex, since small shear strains would develop near isotropic cancellous bone-implant interfaces. Moreover, the authors suggest that changing the volume fraction of glass fibers used to manufacture the cortical bone would allow a more realistic osteoporotic synthetic femurs to be produced.

Supplementation of grazing beef cows during gestation as a strategy to improve skeletal muscle development of the offspring.

The appropriate supply of nutrients in pregnant cows has been associated with the optimal development of foetal tissues, performance of their progeny and their meat quality. The aim of this study was to evaluate supplementation effects of grazing cows in different stages of gestation on skeletal muscle development and performance of the progeny. Thereby, 27 Nellore cows were divided into three groups (n=9 for each group) and their progeny as follows: UNS, unsupplemented during gestation; MID, supplemented from 30 to 180 days of gestation; LATE, supplemented from 181 to 281 days of gestation. The percentage composition of the supplement provided for the matrices was the following: ground corn (26.25%), wheat bran (26.25%) and soya bean meal (47.5%). The supplement was formulated to contain 30% CP. Supplemented matrices received 150 kg of supplement (1 and 1.5 kg/day for cows in the MID and LATE groups, respectively). After birth, a biopsy was performed to obtain samples of skeletal muscle tissue from calves to determine number and size of muscle fibres and for messenger RNA (mRNA) expression analysis. The percentage composition of the supplement provided for the progeny was the following: ground corn grain (30%), wheat bran (30%), soya bean meal (35%) and molasses (5%). The supplement was formulated to contain 25% CP and offered in an amount of 6 g/kg BW. Performance of the progeny was monitored throughout the suckling period. Means were submitted to ANOVA and regression, and UNS, MID and LATE periods of supplementation were compared. Differences were considered at P0.10). Similarly, no differences were observed between calves for nutrient intake (P>0.10). However, greater subcutaneous fat thickness (P=0.006) was observed in the calves of LATE group. The ribeye area (P=0.077) was greater in calves born from supplemented compared with UNS cows. The supplementation of pregnant cows did not affect the muscle fibre size of their progeny (P=0.208). On the other hand, calves born from dams supplemented at mid-gestation had greater muscle fibre number (P=0.093) compared with calves from UNS group. Greater mRNA expression of peroxysome proliferator-activated receptor α (P=0.073) and fibroblast growth factor 2 (P=0.003) was observed in the calves born from MID cows. Although strategic supplementation did not affect the BW of offspring, it did cause changes in carcass traits, number of myofibres, and mRNA expression of a muscle hypertrophy and lipid oxidation markers in skeletal muscle of the offspring.

Reducing mineral usage in feedlot diets for Nellore cattle: I. Impacts of calcium, phosphorus, copper, manganese, and zinc contents on microbial efficiency and ruminal, intestinal, and total digestibility of dietary constituents.

This study evaluated intake, microbial efficiency, and ruminal, small and large intestinal, and total digestibility of DM, OM, CP, and NDF, as well as availability of Ca, P, Mg, Na, K, Cu, Mn, and Zn in Zebu cattle fed with or without supplemental sources of Ca and P or a micromineral premix. Five rumen- and ileum-cannulated Nellore bulls (BW = 200 ± 10.5 kg; 9 mo) were used in the experiment, distributed in a 5 × 5 Latin square design. The experiment was developed in a 2 × 2 + 1 factorial design to measure the effects of mineral supplementation on intake, digestibility, and site of nutrient absorption. The factors consisted of 2 Ca and P levels (macromineral factor; CaP+ or CaP-) and 2 microminerals levels (micromineral factor; CuMnZn+ or CuMnZn-). In addition, a treatment with alimentary restriction (REST) was evaluated at 1.7% of BW. Nutrient fluxes were measured in the omasum and ileum, in addition to intake and fecal excretion. Microbial efficiency was estimated using purine derivative excretion. Dry matter, OM, NDF, CP intake, and total digestibility were not affected ( ≥ 0.058) by the absence of Ca, P, Cu, Mn, and Zn supplementation. Intake of Ca, P, and Mg were reduced ( < 0.01) by CaP-. The absence of CuMnZn reduced ( < 0.01) Cu, Mn, and Zn intake. Ruminal recycling of P, Na, and K is significant for increasing the influx of these minerals to the digestive tract; however, influences of treatments were not observed. The small and large intestines contributed to mineral absorption in different proportions ( < 0.05), according to minerals and treatments. Because of the similarity ( > 0.05) of OM, NDF, and CP digestion sites and coefficients, we assume that omitting supplemental sources of Ca, P, Cu, Mn, and Zn may be an option in raising cattle on feedlots. If supplementation is viable, knowledge about the specific absorption site of each mineral could positively impact choices about the supplemental source.

Effects of supplements containing different additives on nutritional and productive performance of beef cattle grazing tropical grass.

A grazing trial was carried out to evaluate the inclusion of three feed additives in supplements (crude protein, CP 230 g/kg dry matter, DM) on the performance, voluntary intake, and digestibility of beef heifers grazing Brachiaria decumbens (CP 81 and neutral detergent fiber, NDF 615 g/kg DM). Thirty-five Nellore heifers (21 months of age and 383 ± 6.29 kg of body weight, BW) were used in a completely randomized design. The treatments were as follows: no supplement (control); supplement fed at 1 kg/animal/day without additives (S); supplement with monensin (S + M); supplement with yeast culture (S + YC); and supplement with enzyme complex (S + EC). All of the supplemented heifers had greater (P < 0.1) average daily gain (∼0.186 kg/day) compared to the control treatment (0.014 kg/day). Average daily gain and final BW were similar (P > 0.1) among supplemented heifers. Monensin inclusion in the supplement decreased (P < 0.1) forage DM (expressed as g/kg BW) and NDF intake (expressed as kg/day and as g/kg BW). All of the feed additive inclusions decreased (P < 0.1) NDF digestibility. In conclusion, the heifers' performance was improved by concentrate supplementation. However, the inclusion of additives did not enhance this effect.

Crude extract of cyanobacteria (Radiocystis fernandoi, strain R28) induces liver impairments in fish.

Radiocystis fernandoi R28 strain is a cyanobacterium which produces mostly the RR and YR microcystin variants (MC-RR and MC-YR, respectively). The effects of crude extract of the R. fernandoi strain R28 were evaluated on the protein phosphatases and on the structure and ultrastructure of the liver of the Neotropical fish, Hoplias malabaricus, after acute and subchronic exposure. Concomitantly, the accumulation of the majority of MCs was determined in the liver and muscle. The fish were exposed to 120.60 MC-RR+MC-LR kg-fish-1 (=100µg MC-LReq kg-fish-1) for 12 and 96h (one single dose, acute exposure) and 30days (one similar dose every 72h, subchronic exposure). MCs did not accumulate in the muscle but, in the liver, MC-YR accumulated after acute exposure and MC-RR and MC-YR accumulation occurred after subchronic exposure. Protein phosphatase 2A (PP2A) activity was inhibited only after subchronic exposure. Acute exposure induced liver hyperemia, hemorrhage, changes in hepatocytes and cord-like disorganization. At the ultrastructural level, the decreasing of glycogen and lipid levels, the swelling of mitochondria and whirling of endoplasmic reticulum suggested hepatocyte necrosis. Subchronic exposure resulted in a complete disarrangement of cord-like hepatocytes, some recovery of mitochondria and whirling endoplasmic reticulum and extensive connective tissues containing fibrous materials in the liver parenchyma. Despite microcystin toxicity and liver alterations, no tumor was induced by MCs. In conclusion, the increased algal mass of R. fernandoi in tropical freshwater, producing mainly MC-RR and MC-YR variants, results in fish liver impairments.

Effects of Supplements with Different Protein Contents on Nutritional Performance of Grazing Cattle During the Rainy Season.

The objective of this study was to evaluate the effects of supplements with different crude protein (CP) contents on grazing cattle intake, digestibility, ruminal fermentation pattern, and nitrogen (N) metabolism characteristics during the rainy season. Five ruminal and abomasal cannulated Holstein×Zebu steers (296 kg body weight, BW) were used in a 5×5 Latin square design. The animals grazed five signal grass paddocks (0.34 ha). The five treatments evaluated were: Control (no supplement) and 1.0 g of supplement/kg BW with 0, 330, 660, and 1,000 g of CP/kg as-fed. The supplement was composed of starch, soybean meal, urea, and ammonium sulphate. There was a positive linear effect (p≤0.033) of the CP content in the supplements on the organic matter (OM), CP, and digested OM intakes. The provision of supplements did not increase (p≥0.158), on average, total and ruminal digestibilities of OM and CP. However, the increase in CP content in the supplements caused a positive linear effect (p≤0.018) on ruminal digestibilities of OM and CP. Additionally, a quadratic effect of the CP contents of the supplements were observed (p = 0.041) for the ruminal digestibility of neutral detergent fiber corrected for ash and protein, with the highest estimate obtained with the CP content of 670 g/kg. The supply of supplements increased (p<0.001) the ruminal ammonia N concentration, which also changed linearly and positively (p<0.001) according to increase in CP content in the supplements. The apparent N balance and relative N balance (g/g N intake) were not, on average, changed (p≥0.164) by the supplements supply. However, both showed a tendency of a linear increase (p≤0.099) with increasing supplement CP content. The supplements increased (p = 0.007) microbial N production in the rumen, which also changed linearly and positively (p = 0.016) with increasing supplement CP content. In conclusion, protein supplementation in grazing cattle during the rainy season, while stimulating voluntary forage intake, results in higher efficiency of N utilization when compared to energy supplementation. This is a possible response to increased microbial protein synthesis in the rumen and improved N status in the animal body.