ABSTRACT
Regenerative therapies aimed at replacing photoreceptors are a promising approach for the treatment of otherwise incurable causes of blindness. However, such therapies still face significant hurdles, including the need to improve subretinal delivery and long-term survival rate of transplanted cells, and promote sufficient integration into the host retina. Here, we successfully delivered in vitro-derived human photoreceptor precursor cells (PRPCs; also known as immature photoreceptors) to the subretinal space of seven normal and three rcd1/PDE6B mutant dogs with advanced inherited retinal degeneration. Notably, while these xenografts were rejected in dogs that were not immunosuppressed, transplants in most dogs receiving systemic immunosuppression survived up to 3-5 months postinjection. Moreover, differentiation of donor PRPCs into photoreceptors with synaptic pedicle-like structures that established contact with second-order neurons was enhanced in rcd1/PDE6B mutant dogs. Together, our findings set the stage for evaluating functional vision restoration following photoreceptor replacement in canine models of inherited retinal degeneration.
Subject(s)
Retinal Degeneration , Animals , Cell Differentiation , Dogs , Humans , Immunosuppression Therapy , Photoreceptor Cells/transplantation , Photoreceptor Cells, Vertebrate , Retina , Retinal Degeneration/therapyABSTRACT
The kidneys and adrenal glands of the African palm Squirrel (Epixerus ebii), were subjected to histological and mucin histochemical studies. The kidney was covered by a capsule of periodic acid of shiff (PAS) positive connective tissue fibres. The kidney parenchyma was composed of large peripheral cortex and smaller centrally placed medulla. The cortex contained renal corpuscle, proximal convoluted tubules, distal convoluted tubules and juxtaglomerullar complex. At the hilus, the renal artery and vein, ureters, and nerve fibres were surrounded by adipose tissue. The renal medullar was composed of Henles loop and collecting ducts. The adrenal gland cortex contained zona glomerulosa, zona fasciculate and zona reticulata. The zona fasciculata was the largest of the zones containing polyhedrally shaped cells with less basophilic nuclei and very foamy cytoplasm. Some cells of zona fasciculate were binucleated. The adrenal medulla contained mostly glandular cells, few ganglion cells and capillaries. This study establishes that the organs investigated are typical of mammals. It will fill the knowledge gap, help wildlife clinicians in disease diagnosis of these organs in this species.
Los riñones y las glándulas adrenales de la ardilla de la Palma Africana (Epixerus ebii) fueron objeto de estudios histológicos y de estudios histoquímicos con mucina. El riñón estaba cubierto por una cápsula de fibras de tejido conectivo que resultaron positivas a la coloración con ácido peryódico de Schiff (PAS). El parénquima renal estaba constituido por una gran corteza periférica y una médula más pequeña, ubicada centralmente. La corteza contenía el corpúsculo renal, los túbulos contorneados proximales, los túbulos contorneados distales y un complejo yuxtaglomerular. A nivel del hilio del órgano, la arteria y vena renales, los uréteres y las fibras nerviosas estaban rodeados de tejido adiposo. La médula renal estaba compuesta por el asa de Henle y los túbulos colectores. La corteza de la glándula adrenal contenía las zonas glomerular, fasciculada y reticular. La zona fasciculada era la mayor de las tres y contenía células con forma poliédrica con núcleos menos basofilícos y citoplasma muy esponjoso. Algunas células de la zona fasciculada eran binucleadas. La médula adrenal contenía principalmente células glandulares y pocas células ganglionares y capilares. Los resultados de este estudio establecieron que los órganos investigados son típicos de los mamíferos. Esta investigación llenará la brecha de conocimiento existente y ayudará a los clínicos de fauna silvestre en el diagnostico de enfermedades de estos órganos en esta especies.
ABSTRACT
The stomach of the farmed African catfish (Clarias gariepinus, Siluriformes: clariidae) was investigated in this study to establish its basic anatomy, as there is scanty information available on the literature. It produced to baseline data for further investigative research, help fish clinicians in pathology and aid nutritionists in feed management. After cropping from a commercial aquaculture, apparently healthy fish were immobilized and euthanized by using chloroform. The samples were dissected and slices of cardiac, fundic and pyloric stomach processed through routine histological procedures. Grossly, the stomach was J-shape. Cranial to the stomach was the oesophagus but no sphincter was seen separating them. Caudally, a pyloric sphincter separated the stomach from the proximal intestine. The stomach contained three regions cardiac, fundic and pyloric. The entire stomach surface was lined by a simple columnar epithelium containing mucin at the apical cytoplasm. Only the cardiac and fundic regions contained gastric glands in the lamina propria, but the glands were more developed in the fundic region. The tunica muscularis contained smooth muscle cells in an inner circular and outer longitudinal orientation. Mucin histochemistry revealed the presence of only neutral mucin in the stomach. The results obtained in this study suggest that the absence of gastric glands in the pylorus may be an adaptation of this species to reduce the quantity of acid entering the proximal intestine; hence it might help the alkaline medium to maximize pancreatic enzyme actions in the proximal intestine. The presence of only neutral mucin in the stomach will act as a buffer to neutralize the high acidic stomach content. Neutral mucins are also associated with transport of macromolecules.
Se efectuó un estudio de tipo histológico e histoquímico con mucina, en el estómago del bagre africano (Clarias gariepinus, Siluriformes: clariidae) cultivado en granja acuícola, para establecer su anatomía básica, debido a la escasa información disponible en la literatura. La investigación generó datos para ulteriores investigaciones, que contribuirán con los ictiopatólogos y ayudarán a los nutricionistas en el manejo alimentario. Después de su cultivo en una granja acuícola comercial, los peces aparentemente sanos, fueron inmovilizados y sacrificados, usando cloroformo. Se tomaron muestras de las regiones cardial, fúndica y pilórica, y se procesaron histológicamente. En su conjunto, el estómago presentaba una apariencia de J. El esófago estaba situado cranealmente al estómago, pero no se observó un esfínter que los separara. Caudalmente, un esfínter pilórico separaba al estómago del intestino proximal. El estómago contenía tres regiones: cardiaca, fúndica y pilórica. La totalidad de la superficie estomacal se encontraba recubierta por un epitelio cilíndrico, que contenía mucina en el citoplasma apical. Solamente las regiones cardiaca y fúndica tenían glándulas gástricas en la lámina propia, que eran más desarrolladas en la región fúndica. La túnica muscular poseía células musculares lisas con una orientación interna circular y externa longitudinal. La histoquímica mediante la mucina reveló la presencia solo de mucina neutra en el estómago. Los resultados obtenidos en este estudio sugieren que la ausencia de glándulas gástricas en el píloro, pudiera ser el resultado de una adaptación de esta especie para reducir la cantidad de ácido que penetra en el intestino proximal; por tanto, pudiera ayudar al medio alcalino a maximizar las acciones de las enzimas pancreáticas en el intestino proximal. La sola presencia de mucina neutra en el estómago actuaría como amortiguador contra el elevado contenido ácido del estómago. Las mucinas neutras también están asociadas con el transporte de micromoléculas.
ABSTRACT
The mandibular salivary gland microscopic morphology of the adult African giant pouched rat was investigated. This study was carried out to provide the basic histology of this organ in the giant pouched rat, as there is dearth of information of its microscopic architecture in available literature. This is of the most importance, as the possible use of this species of rodent is considered as a future laboratory animal instead of the Wistar rat because of its bigger size; also, for purposes of domestication and use as a ready source of animal protein. Hence the need to understand the digestive biology to help animal nutritionist in feed formulation. Histology revealed the presence of both serous and mucus secretory acini. Some mucous cells presented serous demilunes. Myoeithelial cells were seen around secretory cells and the intercalated ducts. The serous gland region with more relatively profuse intralobular ducts was larger in size than the mucus gland region. The intralobular ducts of intercalated and striated ducts were lined by simple cuboidal and simple columnar cells respectively. The excretory duct was lined by stratified cuboidal cells. The large serous glandular region reflects the need for more enzymic action in the oral cavity, while the mucus glands will help produce mucin that will lubricate the digestive tract. This study for the first time documents the normal histology of the mandibular salivary gland in this species, hence filling a gap that will help further investigative research, especially the role of myoepithelial cells in secretory glands tumors
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