69 research outputs found
Both embryonic and adult stem cells give rise to endodermal derivatives such as cells of the pancreas and liver
The histological appearance ofcarbon fibre implants and neo-ligament in man
The results of this study indicate that a fibrous ingrowth occurs in man after surgical replacement of a tendon or ligament with carbon fibre. This ingrowth resembles normal tendon or ligament very closely, with parallel orientation of collagen fibres and fibroblasts. A multinucleate foreign-body giantcell response was seen, but it was not possible to ascertain whether the fragmented carbon lay within or on these cells and other macrophagic components. Numerous intact carbon fibres were still present 2 and 3 years after implantation
The histology of the adrenal gland of the African elephant, Loxodonta africana
The histology, particularly the ultrastructural cytology, of the adrenal gland of the African elephant, Loxodonta africana, is virtually unknown. Tissue from 14 adult male and female elephants was processed for light and transmission electron microscopy. The gland is surrounded by a thick capsule composed of an outer layer of dense connective tissue and an inner layer in which smooth muscle fibres predominate. Below the layer of smooth muscle, a continuous layer of relatively undifferentiated ‘capsular’ cells occur. Where the capsular cells abut on the zona glomerulosa, they appear to be differentiating into glomerulosa cells, as small lipid droplets are present in their cytoplasm. The cortex is divided into three zones as is found in the adrenal glands of other mammals. Large amounts of collagenous and reticular tissue support the secretory cells, which have a marked lipid content. With electron microscopy, the cortical cells show features typical of steroid-producing cells. The medulla is characterized by an outer region of pale-staining chromaffin-positive (adrenaline) cells and an inner region of intensely staining chromaffin-positive (noradrenaline) cells. The latter cells contain granules of different sizes and structure
A short account of metastatic bone disease
In adults, bone is the preferential target site for metastases from primary cancers of prostate, breast, lungs and thyroid. The tendency of these cancers to metastasize to bone is determined by the anatomical distribution of the blood vessels, by the genetic profile of the cancer cells and by the biological characteristics of the bone microenvironment that favour the growth of metastatic cells of certain cancers
The adrenal gland of the African buffalo, Syncerus caffer: A light and electron microscopic study
Although the histology of the adrenal gland of many mammals, particularly domestic animals, is known, the histology of that of the African buffalo, Syncerus caffer, has not been described previously. Tissue from seven male and female adult buffalo was processed for light and electron microscopy. The gland is surrounded by a connective tissue capsule which contains smooth muscle fibres. The cortex of the gland is divided into three distinct zones with the cells of the outer zone being arranged in arcades rather than in glomeruli. The cells of this zona arcuata and of the outer region of the fasciculata have features typical of steroid-producing cells. The inner part of the fasciculata is a broad, less vacuolated and more intensely stained region than the outer region. Cells of the zona reticularis are arranged in freely anastomosing cords and are less vacuolated than the arcuata and the outer part of the fasciculata. The medulla is characterized by two distinct regions: an outer region of cells with granules of varying electron density which do not stain specifically with the Masson-Fontana technique and an inner zone of cells containing intensely electron dense granules which are chromaffin positive. These cells are adrenaline- and noradrenaline-secreting cells, respectively. The structure of the gland is thus typical of that of other mammals
The effect of TGF-β1 and high glucose on the development of insulin cells in the chick pancreas
How can an understanding of plant-pollinator interactions contribute to global food security?
Pollination of crops by animals is an essential part of global food production, but evidence suggests that wild pollinator populations may be declining while a number of problems are besetting managed honey bee colonies. Animal-pollinated crops grown today, bred in an environment where pollination was less likely to limit fruit set, are often suboptimal in attracting and sustaining their pollinator populations. Research into plant-pollinator interactions is often conducted in a curiosity-driven, ecological framework, but may inform breeding and biotechnological approaches to enhance pollinator attraction and crop yield. In this article we review key topics in current plant-pollinator research that have potential roles in future crop breeding for enhanced global food security
Increased Birth Weight Associated with Regular Pre-Pregnancy Deworming and Weekly Iron-Folic Acid Supplementation for Vietnamese Women
Low birth weight is an important risk factor for neonatal and infant morbidity and mortality and may impact on growth and development. Maternal iron deficiency anaemia contributes to intrauterine growth restriction and low birth weight. Hookworm infections and an iron-depleted diet may lead to iron deficiency anaemia, and both are common in many developing countries. A pilot program of deworming and weekly iron-folic acid supplementation for non-pregnant women aiming to prevent iron deficiency was implemented in northern Vietnam. We compared the birth weight of babies born to women who had had access to the intervention to babies born in districts where the intervention had not been implemented. The mean birth weight of the intervention districts' babies was 124 g more than the control districts' babies; the prevalence of low birth weight was also reduced. These results suggest that providing women with deworming and weekly iron-folic acid supplements before pregnancy is associated with increased birth weight in rural Vietnam. This intervention was provided as a health system integrated program which could be replicated in other at-risk rural areas. If so it could increase the impact of prenatal and antenatal programs, improving the health of both women and newborns
Erratum to: Methods for evaluating medical tests and biomarkers
[This corrects the article DOI: 10.1186/s41512-016-0001-y.]
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