Search PubMed⌕ Search

Biomedical subjects

E Adeghate

Publications and source records attributed to E Adeghate.

79 records · Page 5Linked to original sources
PubMed1988

Re-innervation of pancreatic tissue implants in normal and in sympathetically denervated eyes of rats.

Embryonic, newborn and adult pancreatic tissue fragments were implanted into the anterior eye-chamber of rats of the same offspring to determine whether there is any difference in the pattern of their re-innervation. In another experiment the embryonic pancreatic tissue fragments were implanted into sympathetically denervated eyes of homologous rats. Newborn, adult and embryonic pancreatic tissue implants were removed under a stereo-microscope after 17, 45 and 53 days, respectively. The embryonic pancreatic tissue implants in denervated eyes were removed after 46 days. The implants were processed for electron microscopy. The embryonic, newborn and adult pancreatic tissue implants were equally well re-innervated by agranular and granular vesicle-containing nerve terminals and varicosities from the host iris. The embryonic pancreatic tissue implants were also re-innervated in sympathetically denervated eyes, most likely by parasympathetic nerves of the iris. Except for the few intrinsic nerve profiles, the re-innervating nerve fibres seemed to reach the implant stroma through the blood vessels revascularizing the implants. The re-innervation of the endocrine pancreas is more pronounced than that of the whole tissue.

Animals↗
PubMedDate not supplied

Distribution of neuropeptide Y and vasoactive intestinal polypeptide immunoreactive nerves in normal and transplanted pancreatic tissue.

Neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) immunoreactive nerves were demonstrated in 21-day-old embryonic pancreatic tissue fragments transplanted into the anterior eye chamber of rats for 22, 45 and 109 days and in 60-day-old normal adult pancreas using immunohistochemical technique. In normal adult tissue, NPY-positive neurons lie close to the basal and lateral walls of the acinar cells. NPY-containing nerve fiber plexuses were found around blood vessels. VIP-immunopositive nerves were also discernible in the outer parts of the islets of Langerhans and on pancreatic ducts. In the transplants, it is not only the neural elements that survived but also the pancreatic ducts and the endocrine cells. VIP- and NPY-positive neurons were found in the stroma of the surviving pancreatic tissue. The distribution of these neural elements is similar to that of normal tissue in the surviving pancreatic ducts but different with regards to the acinar tissue. This study confirms that intrinsic nerves can survive and synthesize polypeptides even after 109 days of transplantation into the anterior eye chamber.

Animals↗
PubMedDate not supplied

Dopamine-beta-hydroxylase-positive nerves in normal and transplanted pancreatic tissue in the anterior eye-chamber of rats.

Dopamine-beta-hydroxylase(DBH)-positive nerves were demonstrated in normal and in pancreatic tissue fragments transplanted for 22 and 32 days into the anterior eye-chamber of rats using immunohistochemical techniques. Dopamine-beta-hydroxylase-immunopositive neurons of different shapes could be observed in normal pancreas. The neurons had either spindle or oval shapes. In the transplanted tissue, DBH-positive neuronal profiles were found in the stroma. In some cases DBH-immunopositive cells appeared as a cluster of cells around pancreatic ducts and blood vessels or as solitary cells. The wall of pancreatic ducts in the transplants also contained DBH-immunopositive nerve profiles.

Animals↗
PubMedDate not supplied

Distribution of insulin like growth factor-1 (IGF-1) and its receptor in the intestines of the one-humped camel (Camelus dromedarius).

The distribution of insulin-like growth factor-1 (IGF-1) and its receptor in the gut of the one-humped camel (Camelus dromedarius) were studied by immunohistochemistry and quantitative receptor autoradiography. IGF-1-IR cells occurred mainly in the lamina propria and epithelium of the small intestine, while in the large intestine positive cells were seen in the columnar cells of the epithelial layer of colonic glands. IGF-I was also discernible in the muscularis externa of the intestines. Autoradiography revealed a higher concentration of receptors in the mucosa compared to the muscular layer. With regard to the mucosa, the highest density of receptors was discernible in the duodenum. Immunohistochemistry revealed the main sites of the receptors to be the lamina propria, epithelia of the crypts and the villi of intestines. Double immunofluorescence studies with combined antisera to IGF-I and its receptor showed that the ligand and its receptor usually occurred within the same cell in the mucosa. A few cells with varied profiles immunoreacted to either the ligand or the receptor but not to both. Cells with varied profiles immunoreacted to antiserum of the receptors but not to the ligand in the muscle layer. Thus IGF-1 might be acting on its receptor via both an autocrine and paracrine modes in the camel mucosa. In the muscularis layer, IGF-1 may be acting by different mechanisms. Our data demonstrate that unlike all other mammals studied, the camel contains a high concentration of IGF-1 receptors in the duodenal mucosa compared to other parts of the camel gut. It also possesses a higher concentration of the receptor in its mucosa compared to the muscle layer. We speculate that this might be a significant feature necessary for the regenerative ability of the duodenal mucosa in the one-humped camel.

Animals↗
PubMedDate not supplied

Mal de Meleda: a report of four cases from the United Arab Emirates.

Mal de Meleda (MDM), or recessive transgressive palmoplantar keratoderma, is a rare disorder. MDM may have originated as a founder mutation that occurred on the island of Meleda, now Mljet, in Croatia, where it was first described. However, the condition has also been observed in countries distant from Mljet. The presentation of the disease in young patients has not been reported and the progressiveness of the lesions is debated. We examined four young United Arab Emirates nationals patients (ages 7 months to 12 years) who presented with keratoderma palmoplantaris (KPP) and transgressive pachyderma (TP) that had both been present before 1 year of age. KPP and TP were more pronounced in the two oldest patients. Family histories were consistent with autosomal recessive inheritance. The development of MDM lesions appears to be age-related. However, environment and individual factors may also play a role in the development and persistence of the lesions. Molecular genetic studies are necessary to establish whether the broad clinical presentation of the disease is due to allelic or genetic heterogeneities.

Child↗
PubMedDate not supplied

Ultrastructural cytochemistry of acetylcholinesterase enzyme activity in pancreatic tissue transplants in rats.

The distribution of acetylcholinesterase (AChE) at the ultrastructural level was investigated in normal and in pancreatic fragments transplanted for 56 days into the anterior eye chamber of heterologous rats using enzyme cytochemical methods. Acetylcholinesterase reaction products were seen on the basal surface of the acinar cells in normal pancreas. Acetylcholinesterase enzyme activity was also detected on the axolemma of the surviving nerve fibres. This enzyme reaction product forms alternating thick and thin bands on the axolemma. Some of these AChE-positive nerve fibres accompany blood vessels that also survive after transplantation. AChE were seen in cytoplasm adjacent to the surviving alpha and pancreatic polypeptide cells. We conclude that the ability of some neurons and cells to produce and or store acetylcholinesterase is still retained after transplantation of pancreatic tissue into the anterior eye chamber of rats.

Acetylcholinesterase↗