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Biomedical subjects

A Saadoun

Publications and source records attributed to A Saadoun.

13 recordsLinked to original sources
PubMed2006

Fasting duration influences the inhibition of food intake by histamine in chickens.

This work was performed to investigate the effect of duration of fasting in the responses of chickens peripherally injected with histamine on the regulation of food intake. The animals were 16-week-old male chickens from layer-strain and the doses of histamine used were 500 and 1000 microg/kg of body weight. The non fasted chickens showed no effect of histamine on the food intake. When the animals were fasted during 4 h, injected with the histamine and immediately refed, the results showed a reduction of food intake only the first 15 min of the experiments with the dose of 1000 mug. In chickens fasted during 16 h or 26 h and refed, the histamine inhibited significantly the food intake at all time with the two doses. When the animals were fasted 16 h and refed during 60 min before the administration of the histamine, there is no inhibition of food intake. No effect on water intake has been registered in all the experiments. The blockade of the action of histamine injected in chickens fasted during 16 h by cimetidine and promethazine, show that the inhibition of food intake occurs through the H1 but not through H2 receptors. The fasting used in paradigm to investigate the effect of drugs such as histamine on the appetite, can affect differently the responses according to its duration, as observed here in chickens.

Animals↗
PubMed2002

Effect of the 5-HT(1A) receptor agonist 8-OH-DPAT on food and water intake in chickens.

The effects of the 5-HT(1A) receptor agonist 8-OH-DPAT on food and water intake in 16-week-old male chickens were investigated. Injection of 25 or 50 microg/kg of 8-OH-DPAT 15 min before refeeding starved animals (starved-refed) produced a decrease in food intake 1 h after the start of refeeding. No effect was observed in water intake. The injection of 25 or 50 microg/kg of the 8-OH-DPAT 60 min after the start of refeeding (fed) produced increased food intake, but no effect was observed on water intake. The agonist 8-OH-DPAT (50 microg/kg) injected in water-deprived chickens 15 min before water presentation produced a rapid increase in water intake and an increase in food intake 90 min after the presentation of water. The effect on food intake was mainly apparent 60-90 min after injection. However, when the chickens were water-deprived, the intravenous administration of 8-OH-DPAT 15 min before the presentation of water produced an increase in water intake only 15 min after the start of the experiment. The results show that the effect on food intake of the agonist 8-OH-DPAT in chickens was similar to that observed in mammals. Also, the results show that the agonist-induced increase in water intake may act via a different mechanism. The results show that the 8-OH-DPAT, as in mammals, has a complex effect on food and water intake in chickens and that further works need to be carried out to understand the mechanisms involved in the food and water intake using different animal models.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1999

Aesthetic soft tissue integration and optimized emergence profile: provisionalization and customized impression coping.

In the anterior region, the successful replacement of a single tooth with an implant-supported restoration is one of the most difficult treatment options due to numerous functional and biological requisites. Such prostheses should also satisfy the increasing aesthetic demands of patients who expect the definitive restoration to mimic the natural dentition and their supporting gingival tissues. This article highlights the importance of the provisional restoration as the critical element for aesthetic success and gingival integration. Its perfect replication in the definitive restoration requires the use of optimized transference techniques.

Adult↗
PubMed1996

Scintigraphic detection of invasive cutaneous malignant melanoma with Tc-99m MIBI.

Malignant melanoma is a relatively uncommon cancer of increasing incidence. The authors report on two cases of malignant melanoma lesions (primary and lymph node metastasis) imaged with Tc-99m MIBI. One patient revealed intense accumulation of the radiotracer in a primary skin lesion of the thorax, whereas the other patient showed increased Tc-99m MIBI uptake in a lymph node metastasis of the neck. Tc-99m MIBI imaging could be helpful in the evaluation of patients with suspicious skin lesions and in patients with known cutaneous malignant melanoma, in the investigation of lymph nodal invasion, local recurrence, and metastatic spread.

Adult↗
PubMed1991

Plasma lipoproteins and liver lipids in two breeds of geese with different susceptibility to hepatic steatosis: changes induced by development and force-feeding.

Susceptibility to fatty liver in the force-fed goose is partly under genetic control. However, the mechanisms leading to liver steatosis in this avian model are poorly understood, but may involve perturbation in hepatic lipoprotein synthesis. Plasma lipoproteins were fractionated by density gradient ultracentrifugation from plasma of geese differing in their susceptibility to liver steatosis (Landes breed, highly susceptible; Rhine breed, partly resistant). The concentrations and chemical compositions of the major lipoprotein classes (VLDL, IDL, LDL and HDL) were characterized at 8, 22 and 27 wk of age and compared to the lipid composition of the corresponding liver. In non-force-fed geese, the lipoprotein profile was typical of birds, with high-density lipoprotein (HDL) predominating (4-5 g/L). However, at 22 and 27 wk of age, very low-density lipoprotein (VLDL) levels were significantly lower in Landes geese suggesting that this breed may possess a lower ability to export liver lipids, which would explain its susceptibility to liver steatosis when overfed. The livers of force-fed geese were specifically enriched in triglyceride, and to a lesser extent, in cholesteryl esters and non-esterified fatty acids as compared to those of control geese of the same age (27 wk). This accumulation of lipids was more pronounced in the Landes breed and was responsible for the higher liver weight in that breed. In both breeds, liver steatosis was accompanied by an increase in plasma levels of HDL (11 g/L), whereas low-density lipoproteins were essentially absent.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1987

Effect of exogenous corticosterone in genetically fat and lean chickens.

1. The effects of daily injections of corticosterone (1 or 5 mg/bird) on growth, fat deposition, liver lipid and plasma concentrations of uric acid, glucose, insulin and growth hormone were studied using genetically selected lines of fat (FL) and lean (LL) chickens. 2. Both doses of corticosterone depressed body weight gain and increased the liver lipid and the abdominal fat to the same extent in both lines. 3. In both lines, corticosterone caused a dose-dependent increase in the plasma concentrations of uric acid, glucose and insulin in the fasted and refed states. 4. In untreated birds, plasma concentrations of growth hormone (GH) were slightly higher in FL than in LL chickens and slightly decreased during refeeding. The response was not modified by injection of 1 mg corticosterone. Injections of 5 mg decreased plasma GH in both lines in the fasting state and in LL chickens during refeeding. In contrast, the same dose increased GH in FL chickens during refeeding. This contradiction remains unexplained. 5. The results suggest that corticosterone sensitivity is not involved in difference of fattening between FL and LL chickens.

Adipose Tissue↗
PubMed1987

In vivo lipogenesis of genetically lean and fat chickens: effects of nutritional state and dietary fat.

In vivo lipogenesis was estimated in liver and carcass of male chickens selected for leanness (LL) or fatness (FL) by use of tritiated water. Effects of nutritional state and of a high fat diet (90 g/kg) were examined. Different classes of liver lipids were also measured. Fed birds exhibited enhanced hepatic lipogenesis, which was more pronounced in FL than in LL birds (+73%, mean of three experiments). Extrahepatic lipogenesis was poorly influenced by nutritional state in LL birds and not modified in FL ones. The high fat diet induced a fall in liver triacylglycerol and reduced de novo lipogenesis more drastically in liver than in carcass of both lines. Reduction of carcass lipogenesis was less pronounced in FL than in LL. Starvation led to a fall in liver triacylglycerols, nonesterified fatty acids and free cholesterol. The fat diet had similar but less pronounced effects. In most circumstances FL chickens exhibited a higher liver triacylglycerol content than LL ones. Comparison of fed and refed birds 100 min after the beginning of refeeding showed that de novo lipogenesis did not reach a plateau and differences between lines were still not significant.

Animal Feed↗
PubMed1986

In vivo lipogenesis in genetically fat and lean chickens of various ages.

Lipogenesis was studied in vivo in genetically fat and lean male chickens at 2, 5 and 15 weeks of age using tritiated water. At 2 and 5 weeks of age, the liver was the major site of de novo fatty acid synthesis rather than the carcass. Per 100 g of tissue lipogenesis was greater in the carcass at 15 weeks of age than at 2 or 5 weeks. Lipogenesis in the liver did not vary according to age. At 15 weeks of age there was no observable exaggeration in the degree of fattening (as in genetically obese rodents) of fat line chickens. The regulation of fattening in fat line chickens, at least at the onset of sexual maturity, appears to be different to that in genetically obese rodents.

Aging↗
PubMed1986

A radioimmunoassay of chicken growth hormone using growth hormone produced by recombinant DNA technology: validation and observations of plasma hormone variations in genetically fat and lean chickens.

A radioimmunoassay (RIA) of chicken growth hormone (c-GH) has been developed using growth hormone produced by recombinant DNA technology. The best rabbit antiserum was used at 1/300,000 final dilution. Hormone labelling by iodine-125, achieved by chloramine T, allowed a specific activity of 3.7 MBq/micrograms. The equilibrium curves show that optimal conditions of incubation were reached at room temperature for 24 h. This RIA used a second sheep antibody which precipitated the whole c-GH bound to the first antibody in the presence of polyethylene glycol solution (6%) at room temperature for 30 min. In our conditions, sensitivity was about 30 pg of c-GH per tube. Coefficient of variation was around 10%. No cross reaction was found with avian LH and prolactin. Thyrotrophin-releasing hormone (TRH) injection to young chickens induced 20-fold higher plasma c-GH concentrations. Simultaneous injection of somatostatin and TRH slightly reduced these concentrations. Hypoglycemia induced by insulin led to a drop of the plasma c-GH concentration. Conversely, refeeding or glucose load induced slight increases of the c-GH level. Genetically fat chickens tended to exhibit higher plasma c-GH concentrations than lean chickens.

Animals↗
PubMed1983

Comparison of in vivo fatty acid synthesis of the genetically lean and fat chickens.

In vivo lipogenesis was studied in genetically lean or fat male chickens using tritiated water. Fatty acid synthesis was more pronounced in liver than in other tissues in both lines. Liver synthesis was 26% higher in fat birds than in lean. The liver of fat chickens were heavier than those of lean chickens. This difference was partly due to the triglyceride content of the fat line liver.

Adipose Tissue↗
PubMedDate not supplied

Levels of insulin, corticosterone, T3, T4 and insulin sensitivity in fat and lean chickens.

The late generations of fat (FL) and lean (LL) chickens were compared. In the fasted state, plasma glucose was lower in FL chickens, whereas insulin, T3, T4 and corticosterone were unchanged. In the fed state, plasma insulin and T4 were increased in FL chickens whereas glucose, T3 and corticosterone were unchanged. During ad libitum refeeding both plasma glucose and insulin, and to a lesser degree T3, were lower and T4 higher in FL chickens whereas corticosterone remained unchanged between lines. The low glucose and insulin levels observed in FL during refeeding, which were not observed in the F4 generation, were also found after force-feeding. In contrast, during oral glucose tolerance test, as in previous generations, a better glucose tolerance, higher plasma insulin and slightly higher free fatty acid levels were found in FL chickens. The hypoglycemic effect of exogenous insulin was very similar (and poor) in both lines in the fed state and was higher in FL than in LL chickens in the fasted state. From the present and previous studies, a change in the glucose-insulin balance and possibly, in T3, could account for the differences in fattening of both lines.

Animals↗