Antlers - Evolution, development, structure, composition, and biomechanics of an outstanding type of bone.

Antlers are bony appendages of deer that undergo periodic regeneration from the top of permanent outgrowths (the pedicles) of the frontal bones. Of the "less familiar" bone types whose study was advocated by John Currey to gain a better understanding of structure-function relationships of mineralized tissues and organs, antlers were of special interest to him. The present review summarizes our current knowledge about the evolution, development, structure, mineralization, and biomechanics of antlers and how their formation is affected by environmental factors like nutrition. Furthermore, the potential role of antlers as a model in bone biology and several fields of biomedicine as well as their use as a monitoring tool in environmental studies are discussed.

Effects of broiler breeder-feeding programme and feeder space change at photostimulation using maize- or wheat-based diets on eggshell properties and progeny bone development.

1. The effects of diet type, feeding programme and fast- or slow-feed allocation in fast-feathering Cobb 500 broiler breeder hens on eggshell properties and broiler progeny bone development were investigated in a 2 × 2 × 2 factorial experiment. 2. The birds were fed on either maize- or wheat-based diets during rearing and production and on a fast- or slow-feed allocation programme from 14 to 29 weeks of age. At 22 weeks, 69 females from each pen were placed in a layer house where feeder space (FS) either remained similar or was increased. 3. Eggs produced at 33 weeks were incubated, eggshell conductance (G) was determined and a sample of 14 chicks from each treatment combination was taken to obtain bone traits at hatching. 4. Diet type did not influence G, yolk-free body weight (BW), residual yolk weight or relative asymmetry (RA) of any bilateral traits of leg bones of hatchlings. However, breeder diet type was involved on two-way and three-way interaction effects on progeny leg bone traits. 5. Breeders feed restricted according to the slow-feeding programme laid eggs with greater G compared to those managed with the fast-feeding programme, but there was no effect of feeding programme on progeny bone traits at hatching. 6. Eggs from breeders given more FS at photostimulation had greater G than those from breeders provided with similar FS. Maternal FS change did not influence hatchling yolk-free BW; however, breeders given more FS produced progeny with heavier tibias and shanks and longer femurs compared with those provided with similar FS, but only when breeders were fed on maize. Moreover, increased maternal FS at photostimulation was associated with an increased RA of femur length in the progeny. 7. It was concluded that breeder FS change at photostimulation influenced eggshell conductance and consistently affected bone development of the broiler progeny.

The effects of feeding rice in substitution of corn and the degree of starch gelatinization of rice on the digestibility of dietary components and productive performance of young pigs.

A 28-d trial was conducted to evaluate the effect of the main cereal of the diet (corn or rice), heat processing (HP) of rice, and the degree of starch gelatinization (SG) of rice on apparent total tract digestibility (ATTD) of dietary components and productive performance of pigs weaned at 25 d of age. The experimental design was a completely randomized, with 4 treatments and 8 replicates per treatment (5 pigs penned together). Control pigs were fed a complex diet without growth promoters and based on milk products, fish meal, and 50% cooked and flaked corn, with a degree of SG of 84%. Experimental groups received the same complex diet as the control group, but the corn was substituted by rice with 3 different degrees of SG; 11% that corresponded to raw rice and 52 or 76% that corresponded to cooked rice processed under 2 different conditions. Pig growth was measured at 25, 39, and 53 d of age, and ATTD was determined at 29, 39, and 53 d of age. The ATTD of all dietary components except for N increased with age (P <0.01) and were greater for the rice than for the corn diet. Heat processing of rice improved ATTD of all dietary components at 29 d of age, but no beneficial effects were observed at 39 or 53 d of age. Modifying the conditions of HP to increase the degree of SG of rice from 52 to 76% and to reduce mean particle size from 480 to 405 mum did not result in further improvement of nutrient digestibility. From 25 to 53 d of age, pigs fed rice consumed more feed (678 vs. 618 g/d; P <0.05), grew faster (466 vs. 407 g/d; P <0.01), and tended to have greater G:F (0.685 vs. 0.662; P <0.10) than pigs fed corn. In fact, from 25 to 39 d of age, pigs fed rice consumed 23% more feed (P <0.01), grew 29% faster (P <0.01), and had 5% greater G:F (P <0.05) than pigs fed corn. Feeding rice improved performance of weanling pigs, and HP of rice under mild conditions enhanced diet digestibility and productive performance of pigs. Severe processing of rice increased the degree of SG but did not further improve diet digestibility or growth performance.

[A parametric description of the parenteral nutrition protocols of 19 American hospitals]. / Descripción paramétrica de los protocolos de nutrición parenteral de 19 hospitales americanos.

In the preparation of a centralized parenteral nutrition unit project in our hospital, following the creation of a multi-disciplinary commission entrusted with the study of this project, we proceeded to evaluate parenteral nutrition protocols of national and foreign hospitals, as a first approach to the subject. This study evaluates and extracts the data we consider most relevant in a sample of 19 American hospitals. With regard to the types of parenteral diet, we observed that most of them (63%) had "standard diets", mainly formulated with 25% glucose and 4.25% crystalline amino acids. None of the protocols studied contained alternatives to glucose as a calorie-contributor, nor were there special formulae for amino acids, although many of them included it in their therapies for use if considered necessary. In all protocols, the contribution of fats was reduced to concrete situations and administered in a different way to the rest of the food in 73% of cases. With regard to additives, despite the existence of standard formulations of electrolytes and vitamins and oligoelements, in 100% of the hospitals studied, there was the possibility of formulating each element separately. Administration was done in several doses per day in 42% of cases and in 100%, using perfusion pumps. The data obtained from this review was of great value in preparing our own parenteral nutrition protocols.

Stereological study of murine myeloma and hybridoma cells in vitro and in vivo.

Stereologic ultrastructural methods were applied to several cell types involved in the production of monoclonal antibodies against the mitochondrial enzyme glutamic dehydrogenase (GDH). These cell types included SP2/O murine cells, in vitro cultured hybrid cells producing monoclonal antibodies, and the same hybrid cells maintained as solid and ascites tumors (TH and ATH cells, respectively). The statistical analysis of quantitative data indicates that the fusion between SP2/O cells and spleen lymphocytes does not induce significant changes in the fine structure of the former cells. Moreover, the transfer of hybrid cells from in vitro to in vivo conditions induces their transformation from an immature state to mature plasma cells. The increase in mitochondria and rough endoplasmic reticulum suggests that the ascites tumor provides cells with an environment more suitable for expressing their activity than does the solid tumor.