534 research outputs found
Cheese-induced body weight gain is not accompanied by an increase of gastric cells producing leptin, ghrelin, gastrin, or pancreastatin in mice
The stomach is a source of several circulating peptides/hormones, such as gastrin, pancreastatin, leptin and ghrelin, which are thought to play important roles in the regulation of food intake and body growth. The present study was undertaken in mice in order to examine the effects of diet composition on the body weight gain and the gastric cells that produce these peptides/hormones.Both young and adult female mice (BALB/cABBom strain) were given a standard pelleted dry diet, with or without cheese ad libitum, during a 7 week period. The diet supplement consisted either of carbohydrate- free white cheese containing 27% fat or sweet-tasting but sucrose-free Norwegian “brown cheese” containing 29% fat and 39% carbohydrate, mainly lactose. The total intake of the various types of food and the change in body weight were recorded. At the end of the observation period, blood samples were obtained for determination of gastric hormone levels by radioimmunoassay, and the stomachs were removed for examination of hormone producing cells by immunohistochemistry.The young mice increased their body weight more than the adult mice. In the groups offered white cheese, both young and adult mice increased their body weight more than the animals kept on the standard diet alone. In contrast, the “brown cheese” supplement led to a relative overweight only in adult mice. Despite the changes in body weight gain, there were no differences with respect to the circulating levels of gastrin, leptin or ghrelin, and to the numbers of cells stained with antibodies to pancreastatin (including ECL cells and G cells), leptin (subpopulation of chief cells) and ghrelin (A-like cells) in all groups.Body weight gain was increased in both young and adult mice by a white cheese diet supplement, whereas ‘brown cheese’ produced overweight only in adult mice. The increased body weight gain was not accompanied by an icrease of gastric cells producing leptin, ghrelin, gastrin, or pancreastatin
Trichobezoars in praomys (mastomys) natalensis
We have in a rat model studied the role of gastric neuroendocrine cells in the regulation of gastric function and growth and given indication for an important role of these cells in physiology and human carcinogenesis. Because of the high incidence of spontaneous tumors in the glandular stomach of mastomys (Praomys (mastomys) natalensis), we wanted to investigate if mastomys might be an useful model for our further studies.Tumors. were recognized in several organs of our mastomys, but not in the stomach. However, a high incidence oftrichobezoars was observed in the stomach and intestine, and obstruction from thesewas the cause of illness and death for many of them.Multiple factors are involved in the formation of bezoars. and these are discussed in relation to the occurrence in our mastomys colony
Admission Documentation Overhaul
Improve the admission documentation workflow by revamping the admission Navigator and Functional Health Assessmenthttps://digitalcommons.centracare.com/nursing_posters/1117/thumbnail.jp
Morphology of G Cells in Hypergastrinemic Cotton Rats
In a strain of inbred cotton rats, 25-50% of females develop spontaneous gastric hypochlorhydria and hypergastrinemia. Hypergastrinemic animals develop ECL cell derived gastric carcinomas located in the oxyntic mucosa, thus being an interesting animal model for studying the role of gastrin in gastric carcinogenesis. The response to gastric hypoacidity in cotton rats as regards the level of hypergastrinemia is far more pronounced than in the more commonly used laboratory rat. It is unknown whether the pronounced hypergastrinemic response in cotton rats is due to a greater population of G cells or a greater capacity of hormone synthesis in each G cell. The aim of the study was therefore to examine G cell population and ultrastructure in normogastrinemic and hypergastrinemic cotton rats by the use of immunhistochemical methods applied on both light- and electron-microscopy. Five hypergastrinemic vs. five normogastrinemic cotton rats were compared. Cotton rats with gastric hypochlorhydria have a 55-fold increase in serum gastrin levels and a 6-fold increase in G cell number, but this is not accompanied by significant changes in G cell ultrastructure. The lack of ultrastructural changes in these activated G cells indicates that previously reported changes in chronic stimulated G cells are just one of several ways G cells are activated.
Assessment of radiofrequency ablation technique in development of aortic valve stenosis in rabbits
Purpose: To develop a minimally invasive and reproducible model of aortic stenosis in rabbits using radiofrequency ablation technique (RFA).
Material and methods: Eleven rabbits were studied. A radiofrequency ablation catheter was introduced via the femoral artery and advanced to the aortic valve area under fluoroscopic control. In three rabbits radiofrequency energies, at 5 W, 10 W and 15 W respectively, were applied thrice for 90 sec. In eight rabbits, energy of 15 W was applied for the same time periods. The velocity of the blood through the aortic valve was determined by color Doppler ultrasound immediately before and after ablation and after six weeks. After six weeks the rabbits were sacrificed and the aortic valve was examined macroscopically.
Results: Peak systolic velocity (PSV) was similar at the time of ablation and after six weeks in eight of the nine surviving rabbits, and had increased from 1.1 to 1.75 m/s in one rabbit. Two rabbits developed aortic insufficiencies visualized by color Doppler. No macroscopic changes were seen at the aortic valve area 6 weeks after ablation.
Conclusion: In the current study we did not succeed in inducing aortic valve damage/fibrosis using different RFA energies. Inadequate RFA power or inappropriate positioning of the RFA catheter could be limitations of our study
Clear Cell Renal Cancer, a Tumour with Neuroendocrine Features Originating from the Erythropoietin-Producing Cell
The dominating type of kidney cancer is the clear cell renal cell cancer (ccRCC), hitherto been thought to develop from proximal tubule cells. However, the ability of tubule cells to proliferate is at best controversial. ccRCCs show many peculiarities like erythrocytosis due to erythropoietin overproduction and a combination of early metastases and sometimes apparent dormancy and late recurrence, features in common with neuroendocrine tumours (NETs). We have shown that most ccRCCs express erythropoietin and the neuroendocrine marker neuron-specific enolase, and other neuroendocrine markers in a percentage of the cancers. Missense mutation in von Hippel–Lindau (VHL) factor is rather specific for ccRCC found in familial and sporadic forms. The function of VHL factor is together with other proteins to destroy hypoxia-inducible factors (HIFs), central in adaptation to hypoxia. Lack of functioning VHL factor results in continuous overstimulation of the erythropoietin-producing cell to release erythropoietin and parallelly to proliferate, and in long-term mutations and malignant transformation. Thus, ccRCC occurs about 30 years later in sporadic cases compared with familial von Hippel–Lindau syndrome, reflecting the time necessary for two versus one genetic change. Embryologically, there are many arguments favouring neural crest origin of the erythropoietin-producing cell
Animal Models to Study the Role of Long-Term Hypergastrinemia in Gastric Carcinogenesis
Patients with chronic hypergastrinemia due to chronic atrophic gastritis or gastrinomas have an increased risk of developing gastric malignancy, and it has been questioned whether also patients with hypergastrinemia caused by long-term use of acid inhibiting drugs are at risk. Gastric carcinogenesis in humans is affected by numerous factors and progresses slowly over years. When using animal models with the possibility of intervention, a complex process can be dissected by studying the role of hypergastrinemia in carcinogenesis within a relatively short period of time. We have reviewed findings from relevant models where gastric changes in animal models of long-term hypergastrinemia have been investigated. In all species where long-term hypergastrinemia has been induced, there is an increased risk of gastric malignancy. There is evidence that hypergastrinemia is a common causative factor in carcinogenesis in the oxyntic mucosa, while other cofactors may vary in the different models
Investing the "time" in time-based prospective memory
Time-based (TB) prospective memory tasks require the estimation of time in passing - known as prospective timing. Prospective timing is said to depend on an attentionally-driven internal clock mechanism, and is thought to be unaffected by memory for interval information (for a review see, Block & Zakay, 1997). A prospective timing task that required a verbal estimate following the entire interval (Experiment 1) and a TB prospective memory task that required production of a target response during the interval (Experiment 2) were used to test an alternative view that memory does influence prospective timing. In both experiments, participants performed an ongoing task for 11.02 minutes while a varying number of songs were played in the background. Experiment 1 results revealed that participants' time estimates became longer the more songs they remembered from the interval, suggesting that memory for interval information influences prospective time estimates. In Experiment 2, participants who were asked to perform the TB prospective memory task without the aid of an external clock made their target responses earlier as the number of songs increased, indicating that estimates of elapsed time increased as more songs were experienced. For participants who had access to a clock, changes in clock-checking coincided with the occurrence of song boundaries, indicating that participants used both song information and clock information to estimate time. Finally, ongoing task performance and verbal reports in both experiments further substantiate a role for memory in prospective timing
Can you Forget what you Believe? Directed Forgetting of Attitude Information
Research shows that people can intentionally forget previously learned information when instructed to do so - known as the directed forgetting effect (for a review, see MacLeod 1998). The current experiments investigated intentional forgetting of self-relevant information presented in the form of political attitude statements. Groups of Republicans and Democrats participated in two list-method directed forgetting studies, during which they studied a mixture of statements that expressed representative views of these parties. Experiment 1 results revealed that both Republicans and Democrats showed directed forgetting of statements expressing the views of the opposing political party, but showed no directed forgetting of statements expressing the views of their own party. In Experiment 2, participants studied the same statements and also rated them for agreement level. The results confirmed that regardless of the party affiliation, there was no directed forgetting of statements that participants agreed with; however there was directed forgetting of statements with which they disagreed or felt neutral about. Attitudes that people agree with are integrated in memory as an intrinsic part of the self concept, this integration, in turn, acts to prevent directed forgetting of this type of information
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