Growth,Feed Utilization,and Glycemic Response in European Sea Bass,Dicentrarchus labrax,Juveniles Fed Carbohydrate of Different Complexities

The effect of dietary carbohydrate complexity on growth, feed utilization, and glycemia was studied in European sea bass juveniles. Four isonitrogenous (50% crude protein) and isolipidic (15% crude lipids) diets were formulated to contain 20% pregelatinized maize starch (PGS diet), dextrin (DEX diet), maltose (MAL diet), or glucose (GLU diet). No effect of dietary carbohydrate complexity on growth was noticed. Feed efficiency and protein efficiency ratio were lower in fish fed the GLU diet than in the other groups, whereas the opposite was observed for feed intake. Plasma glucose peaked 3–4 h after feeding in fish fed the MAL and GLU diets, whereas in fish fed the PGS and DEX diets the peak was reached 5–6 h after feeding. Peak plasma glucose concentration (13 mmol/L) was higher in fish fed the GLU diet than the other diets (9 mmol/L). Shorter hyperglycemia duration was observed in fish fed the MALT and GLU diets (6 h) than the PGS and DEX diets (10 h). Complex carbohydrates delayed plasma glucose concentration peak compared with simple sugars, whereas the opposite was observed for hyperglycemia duration. Overall, dietary maltose, dextrin, and starch were apparently better utilized as energy source than glucose by European sea bass juveniles.     

CD46 in meningococcal disease

The human-specific bacterial pathogen Neisseria meningitidis is a major cause of sepsis and/or meningitis. The pili of N. meningitidis interact with CD46, a human cell-surface protein involved in regulation of complement activation. Transgenic mice expressing human CD46 were susceptible to meningococcal disease, because bacteria crossed the blood-brain barrier in these mice. Development of disease was more efficient with piliated bacteria after intranasal, but not intraperitoneal, challenge of CD46 transgenic mice, suggesting that human CD46 facilitates pilus-dependent interactions at the epithelial mucosa. Hence, the human CD46 transgenic mice model is a potentially useful tool for studying pathogenesis and for vaccine development against meningococcal disease.     

Variation of extractives content in heartwood and sapwood of Eucalyptus globulus trees

The variation in extractives content in sapwood and heartwood was investigated among 12 trees in each of four commercial plantations of Eucalyptus globulus in central Portugal. The study was carried out at the 15% height level and extractions used successively dichloromethane, ethanol and water. At all sites, heartwood had significantly more extractives than sapwood, on average 3.8 and 2.4%, respectively. Most extractives consisted of ethanol soluble material (on average 52% of total extractives). Among the sites, there was a statistically significant difference in the content of extractives but the most important source of variation was the within-tree variation between sapwood and heartwood. Differences in the content of extractives were also observed among trees. A strong relation between extractives content and heartwood proportion was found. The potential loss of pulp yield and problems associated with accumulation of extractives are directly related to the heartwood proportion in the eucalypt stems. Forest management should take into account heartwood development and selection for minimising heartwood extractives.     

Cadmium Effects in Sunflower: Nutritional Imbalances in Plants and Calluses

The effects of cadmium (Cd) exposure on sunflower (Helianthus annuus L.) nutrient accumulation remain unclear. However, studies concerning crop improvement for Cd tolerance suggest the use of biotechnology techniques such as tissue culture. It is still unknown whether in vitro cells respond to Cd exposure in a way similar to plants. In this paper, the objectives were (1) to characterize the effects of Cd exposure in macronutrient and micronutrient accumulation in different sunflower organs/tissues and (2) to compare the behavior of two culture systems (plants vs. tissue culture) regarding Cd and nutrient accumulation. To achieve these aims, sunflower plants were grown hydroponically in the presence of Cd (at levels of 0, 5, 50, and 500 μ M). For in vitro cultures, seeds were germinated axenically and leaf explants were then grown on Murashige and Skoog medium (MS). One-month-old calluses were grown on MS medium containing 0, 5, 50, and 500 μ M Cd. After 21 d of exposure to 500 μ M, all plants were dead. The contents of macro- and micronutrients and of Cd were determined by ICPS in 18 d-exposed plants and calluses and in calluses exposed for six months to 50 μ M Cd. At day 18, Cd content increased in leaves, roots, and calluses. Cadmium exposure also decreased the contents of magnesium (Mg), calcium (Ca), iron (Fe), and manganese (Mn) in roots and of Mg, Ca, copper (Cu), Fe, and Mn in shoots. Exposed calluses suffered decreases only in Mg, Ca, and Mn contents. The contents of most of these nutrients in six-month-exposed calluses were similar to those of the control calluses, indicating that these long-term exposed in vitro cells developed mechanisms for regulating the effects of Cd on the accumulation of nutrients.     

Treatment of traumatic cervical myelopathy with surgery, prolonged positive-pressure ventilation, and physical therapy in a dog

CASE DESCRIPTION: A 9-year-old dog was evaluated for traumatic cervical myelopathy after a surgical attempt to realign and stabilize the C2 and C3 vertebrae. CLINICAL FINDINGS: The dog could not ventilate spontaneously and was tetraplegic; positive-pressure ventilation (PPV) was maintained. Myelography and computed tomography revealed spinal cord compression with subluxation of the C2 and C3 vertebrae and extrusion of the C2-3 intervertebral disk. TREATMENT AND OUTCOME: Surgically, the protruding disk material was removed and the vertebrae were realigned with screws and wire. For PPV, assist control ventilation in volume control mode and then in pressure control mode was used in the first 6 days; this was followed by synchronized intermittent mandatory ventilation until 33 days after the injury; then only continuous positive airway pressure was provided until the dog could breathe unassisted, 37 days after the injury. Physical therapy that included passive range of motion exercises, neuromuscular electrical stimulation, and functional weight-bearing positions was administered until the dog was discharged 46 days after injury; the dog was severely ataxic and tetraparetic but could walk. Therapy was continued at home, and 1 year later, the dog could run and had moderate ataxia and tetraparesis. CLINICAL RELEVANCE: Hypoventilation with tetraparesis in traumatic spinal cord injury can be successfully treated with PPV exceeding 30 days, surgery, and physical therapy.     

Contrasting effects of heat shock during in vitro maturation on development of in vitro‐fertilized and parthenogenetic bovine embryos

This study investigated the influence of heat shock during in vitro maturation on embryo development following in vitro fertilization (IVF) or parthenogenesis (Part). Immature bovine cumulus–oocyte complexes were exposed to heat shock (41.0°C) during the first 12 hr of in vitro maturation (IVM), followed by 12 hr at 38.5°C. Control group consisted of in vitro maturation for 24 hr at 38.5°C. Oocytes were in vitro‐fertilized or activated with ionomycin and cultured in vitro for 192 hr post‐in vitro insemination or parthenogenetic activation (hpia). There was an interaction (p < .01) between temperature of IVM and method of oocyte activation (IVF or Part) for cleavage at 48 hpia. Heat shock had a negative impact (p < .01) on cleavage of IVF embryos, whereas no (p > .05) effect was found in the Part embryos. Embryo development towards blastocyst stage at 168 and 192 hpia decreased in both IVF and Part embryos derived from heat‐shocked oocytes. Heat shock increased (p < .05) the apoptotic index in Part blastocysts, but no effect (p > .05) was found in IVF counterparts. Heat shock also down‐regulated the expression of AQP3 (p < .01) and up‐regulated the expression of HSP70.1 (p < .01) in Part blastocysts, whereas it down‐regulated the expression of ATP1A1 (p < .05) in IVF blastocysts. In conclusion, the effects of heat shock during IVM on early embryo cleavage and blastocyst apoptosis are influenced by the method of oocyte activation and expression of some genes can be disturbed in embryos derived from heat‐shocked oocytes.     

Use of molecular markers to accelerate the breeding of common bean lines resistant to rust and anthracnose

The main goal of this work was to introduce resistance genes for rust, caused by Uromyces appendiculatus, and anthracnose, caused by Colletotrichum lindemuthianum, in an adapted common bean cultivar through marker-assisted backcrossing. DNA fingerprinting was used to select plants genetically closer to the recurrent parent which were also resistant to rust and to race 89 of C. lindemuthianum. DNA samples extracted from the resistant parent (cv. Ouro Negro), the recurrent parent (cv. Rudá), and from BC₁, BC₂ and BC₃ resistant plants were amplified by the RAPD technique. The relative genetic distances in relation to the recurrent parent varied between 9 and 59% for BC₁, 7 and 33% for BC₂, and 0 and 7% for BC₃ resistant plants. After only three backcrosses, five lines resistant to rust and anthracnose with, approximately, 0% genetic distance in relation to the recurrent parent were obtained. These lines underwent field yield tests in two consecutive growing seasons and three of them presented a good yield performance, surpassing in that sense their parents and most of the reference cultivars tested.     

Influence of Apoptosis in Bovine Embryo's Development

The correlation between apoptosis and early bovine embryonic loss is still not fully elucidated. In the present study, the relationship between the arrest of bovine embryos at the different stages of development and apoptosis was evaluated. We used embryos 7 days after in vitro maturation and fertilization, and morphologic and biochemical apoptotic analyses were performed by using a phase contrast microscope and by the terminal transferase dUTP nick end‐labelling respectively. For the statistic, the apoptotic cell ratio (ACR) was determined as the percentage of apoptotic cells per embryo. To evaluate the relation between ACR and fragmentation pattern, embryos were divided into five groups, groups I–V. To assess the relation between ACR and cytoplasmatic fragmentation, embryos were divided into three groups, according to the fragmentation percentage (<5%; 5–15% and >15%). Of the total 139 embryos included, 65 arrested at 2–8 cells; 14 arrested at 9–16 cells; 18 compacted morula and 42 were non‐arrested blastocysts. The average number of embryonic fragmentation at different stages of the development, 2–8 cells, 9–16 cells, compacted morula and blastocyst, was 16.0 ± 1.5, 28.7 ± 4.4, 4.4 ± 2.4 and 1 ± 0.3 respectively. The embryos at the stage of arrested 9–16 cells and compacted morula had higher ACR than those at the blastocyst stage, excluding the stage of 2–8 cells (the genome is not yet active). The correlation detected between embryonic development and ACR was 0.92 (p < 0.01). It was observed that embryos possessing high fragmentation showed the higher ACR value (r = 0.98, p < 0.05). Comparing the results between fragmentation percentage and ACR, it was observed that the embryos with higher percentage of fragmentation corresponded to higher ACR (r = 0.97, p < 0.01). These results clearly demonstrated that bovine embryonic arrest at different stages of development is correlated with the apoptotic mechanisms.