Gastric mucosal erosions were induced in the glandular stomach of rats by scalding. The incorporation of Thymidine-methyl³-H into desoxyribonucleic acid was used to determine changes in gastric epithelial cell proliferating ability. Total desoxyribonucleic acid per milligram of gastric tissue was also determined. Sampling was done at twenty-four hours, seven days, and fifteen days postburn. Eighty-nine point two percent of rats with a standard 26.5 ± 2% scald burn had developed gastric mucosal erosions by twenty-four hours postburn. Seventeen point eight percent of burned rats had erosions by seven days and the incidence rose to 46.4% by fifteen days postburn. Ten point three percent of control rats in all sampling periods developed erosions. The total desoxyribonucleic acid in the gastric samples did not change significantly in any treatment period nor was it changed by treatment. Uptake of thymidine-methyl³-H was depressed twenty-four hours postburn and renewed so through seven days postburn. The results at the fifteen day sampling were inconclusive. By light microscope, the gastric surface epithelium was lifted from the lamina propria and at times there was complete denudation of this cell layer. The rat is a satisfactory animal model for gross study of mucosal erosions to at least fifteen day postburn. Because of eschar cannibalization inducing variable secretory status, the rat model was not suitable for thymidine uptake studies past seven days postburn. / Surgery, Department of / Medicine, Faculty of / Graduate

The distribution and some of the properties of phosphodiesterase II were studied in homogenates of rat intestinal mucosa in an attempt to elucidate its role in the nucleic acid metabolism of this tissue. In most of the experiments the p-nitrophenyl ester of thymidine 3'-phosphate was used as a substrate for phosphodiesterase. During the work, evidence was accumulated which indicated that phosphodiesterase II of intestine was lysosomal in origin. For instance, when the tissue was suspended (or homogenized) in media of differing tonicity, the phosphodiesterase II activity in the hypotonic preparations increased markedly over a period of 96 hours. Other investigators have shown that this "osmotic activation" is a characteristic of lysosomal enzymes. Subsequently, homogenates of mucosal tissue were fractionated by differential centrifugation and the subcellular fractions obtained were identified by known enzyme markers. The distribution of phosphodiesterase II in the fractions was most similar to that of the marker for lysosomes - acid phosphatase. However a large proportion of the phosphodiesterase II activity, greater than that of acid phosphatase, was found in the supernatant solution remaining after the final high-speed centrifugation step. The highest specific activity for phosphodiesterase II was found in the "light mitochondrial" and "final supernatant" fractions. Similar results were obtained when homogenates or nuclei-free homogenates were fractionated by sucrose density-gradient centrifugation. The distribution patterns of phosphodiesterase II and acid phosphatase were again similar and the particles to which phosphodiesterase II were bound exhibited the highest acid phosphatase activity. An attempt was made to confirm these results by "purifying" lysosomes from intestinal mucosa using a combined differential centrifugation and density-gradient centrifugation technique. During the purification, the specific activities of phosphodiesterase II and acid phosphatase increased parallel with each other and the "purified lysosomal" fractions exhibited the highest specific activities for these enzymes. However the total activities of the two enzymes recovered in the purified fractions were quite small, indicating considerable loss in the discarded soluble fractions. Other workers have shown that homogenization ruptures lysosomes in certain fragile tissues, resulting in high soluble activities of the enzymes contained in these particles. It would seem possible therefore that in intestinal mucosa phosphodiesterase II is located in lysosomes in vivo, since most of its activity was found to be distributed between the lysosomal and soluble fractions of homogenates of this tissue. The phosphodiesterase II of intestine was most active at pH values around neutrality. A second substrate, 2,4-dinitro-phenyl thymidine 3'-phosphate, which was used in only"a few experiments because of its limited availability, was hydrolyzed at a rate faster than that of p-nitrophenyl thymidine 3'-phosphate. Little or no change in the activity of the enzyme was observed in the presence of Mg++, Ca++ or EDTA, but Zn++, Cu++ and Hg++ inhibited markedly. The enzyme was most active at a temperature of 58° and only 27% of the activity was lost on heating the preparation for 1 hour at 55°. The Michaelis constant for the enzyme with p-nitrophenyl thymidine 3'-phosphate was 4.5 x 10(-4) M at 37°, and the activation energy for the phosphodiesterase II catalyzed hydrolysis of the same compound was 14.63 kilocalories/ mole. / Medicine, Faculty of / Biochemistry and Molecular Biology, Department of / Graduate

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Medicine in Anaesthesia Johannesburg, 2015 / Patients with chronic renal failure are considered to be at risk of perioperative pulmonary aspiration and consequently the recommendation is to perform a rapid sequence induction on such patients. Rapid sequence induction is not without its risks and may not be necessary. The aim of this study was to determine whether patients who are on a chronic haemodialysis program have sufficient residual gastric contents after an overnight fast, to place them at risk of pulmonary aspiration of gastric contents during anaesthesia. The presence and volume of gastric content was ascertained by ultrasound examination of the stomachs of twenty patients. Patients were asked to fast overnight and an ultrasound was scheduled for a morning on which the patient was due to come in for a dialysis session. The appearance of the stomach and the contents were graded by the radiologist and the diameters of the gastric antrum were then measured so that the cross sectional area could be calculated. Once the cross sectional area was known the gastric volume was calculated using a validated equation. The risk of perioperative pulmonary aspiration was then assessed according to the graded appearance as well as calculated gastric volumes. If the stomach was found to contain fluid a cut off value of 0.8ml/kg was used as a relative gastric volume that would place the patient at increased risk of perioperative pulmonary aspiration. Any patient with a gastric antrum found to be distended with fluid in both the supine and lateral positions or seen to contain solid contents was assessed as being at increased risk of perioperative pulmonary aspiration. Gastrointestinal symptoms were assessed and compared to residual gastric volumes. Urea and creatinine concentrations were also correlated to residual gastric volumes. In this study none of the patients with chronic renal failure on a chronic haemodialysis program were considered to be increased risk of perioperative pulmonary aspiration, after an overnight fast. Gastrointestinal symptoms were found in 60% of patients. There was no association between gastrointestinal symptoms and residual gastric volumes. There was no correlation between either urea or creatinine levels and residual gastric volumes.

No description available.

Some diabetic patients - particularly those with nausea and vomiting - frequently have evidence of delayed gastric emptying while other diabetic patients may in fact exhibit accelerated gastric emptying. Whether the presence or absence of symptoms of upper gastrointestinal dysfunction correlated with objective measures of gastric emptying in insulin dependent diabetic subjects was investigated. Twenty one insulin dependent diabetic patients underwent a solid phase gastric emptying scintiscan using in vivo labelled chicken patients had symptoms Thirteen patients had symptoms suggestive of gastrointestinal dysfunction (nausea, vomiting, early satiety, or constipation), while eight patients had no gastrointestinal symptoms. Eleven patients had orthostatic hypotension. All patients had been diabetic since childhood or adolescence. As a group, the diabetic patients showed a half time (T50) of gastric emptying (mean (SD) 150.0 min (163.7) that was not significantly different from that of 12 healthy control subjects (148.1 min (62.4)). Those diabetic patients without gastrointestinal symptoms and without orthostatic hypotension, however, showed a gastric emptying half time (70.1 min (41.6)) that was significantly faster than that of the control subjects. Conversely, those diabetic patients with nausea, vomiting, and early satiety (or early satiety alone) showed T50 values that were significantly greater than those of the diabetic patients without these symptoms. No correlation was found between the T50 value and the duration of diabetes, the fasting blood glucose at the time of study, or the respiratory variation in heart rate (E:I ratio). These observations indicate that highly variable rates of gastric emptying occur in insulin dependent diabetic patients, and that accelerated gastric emptying may occur in diabetic patients who have no symptoms of gastrointestinal dysfunction.

Electrical activity of the stomach is one determining factor of gastric motility by controlling and coordinating contractions of the gastric musculature. These contractions, both tonic and phasic, are responsible for the storing, mixing, and emptying of food. Gastric electrical activity is therefore a very important factor for normal stomach function. The development of a multi-channel, bandlimited, signal amplifier and recording system, provides a means to record this electrical activity. Many practical issues are addressed to provide a signal of acceptable quality and several basic signal processing techniques are applied to increase the quality of these signals and provide extraction of important information regarding power and frequency content. Gastric electrical activity is recorded from the stomachs of several rats in various experiments. The recorded activity in different regions of the stomach, responsible for different functions, is compared and evaluated with respect to known cellular events. By introducing several stimuli and observing changes in recorded activity, the nervous control of the stomach via mediation of the electrical activity is also examined and modeled briefly. / Thesis / Master of Engineering (ME)

Bakgrund: Fetma är idag ett ökat världsproblem och följden är att flera genomgår viktminskningsoperationen gastric bypass. Det är viktigt att upplevelserna ur ett fysiskt, psykiskt och socialt synsätt belyses för att ge en ökad förståelse samt att hjälpa dem i rätt riktning. Syfte: Att beskriva personers upplevelse av sin livssituation efter att ha genomgått en gastric bypass operation ur ett fysiskt, psykiskt och socialt perspektiv. Metod: En beskrivande litteraturstudie av elva stycken vetenskapliga artiklar. Huvudresultat: Efter operationen får personerna en mer positiv inställning till livet ur de tre perspektiven. De upplevde att de passade in i samhället, samt orkade delta i sociala och fysiska sammanhang. En tid efter operationen upplevde deltagarna att de föll tillbaka i gamla vanor vilket gav dem en sämre livskvalité. De belyste att operationen var ett verktyg och själva jobbet återstod och en utmaning väntades som vissa hanterade bättre en andra. Slutsatser: Det är viktigt att ge personerna bra stöttning och information för att de ska kunna bevara sin nya livsstil. De genomgår en stor psykisk påfrestning därför behövs det psykoterapi och vägledning till att finna en lämplig copingstratagi för att hantera olika situationer. / Background: Obesity is now a growing problem in the world and as a result, several do gastric bypass surgery for weight loss. It is important that the experiences from a physical, mental and social approach is illuminated to provide a better understanding and to help them to right direction. Aim: To describe the experience situation of life a one person after doing a gastric bypass surgery from a physical, psychological and social perspective. Method: A descriptive study of eleven scientific articles. Results: After a gastric bypass, the people have a more positive attitude towards life according the three perspectives. They experienced that they fit into society and could participate in the social and physical context in a better way than before. Sometime after the surgery, the participants experienced that they were back into the old habits which gave them a worse quality of life. They ment that the operation was a tool but the hard part remained and they expected a challenge, as some managed better than others. Conclusions: It is important to give people good support, and information to enable them to preserve their new lifestyle. They are making a great mental effort, therefore they are indeed of psychotherapy and guidence to find a suitable copingstrategy to handle different situations.

<p>Fetman i Sverige har under de senaste två decennierna ökat kraftigt. Till följd av detta är hälsokostnaderna relaterat till fetma ansenliga och förväntas öka ytterligare om ingenting görs åt problemet. I denna studie studeras prevention och gastric bypass som alternativa behandlingsmetoder mot fetma sett ur ett samhällsekonomiskt perspektiv. Tre hypotetiska kohorter utvecklas; status quo, effektiv prevention i ungdomsåren samt individer som utvecklar svår fetma opereras med gastric bypass. Dessa kohorter följs under åldern 20-64 år där kostnader och effekter observeras med hjälp av en beslutsträdsmodell. Både gastric bypass och prevention påvisas vara kostnadseffektiva behandlingsmetoder mot fetma. Gastric Bypass visas vara mer effektiv än en studerad befolkningsinriktad preventionsåtgärd. Slutligen påvisas att effektiva högriskpreventioner kan bidra med en högre samhällsnytta än gastric bypass operationer.</p><p> </p><p>Nyckelord: Fetma, Gastric Bypass, Prevention</p><p> </p> / <p>The prevalence of obesity has increased rapidly the past two decades. As a consequence the health expenditures related to obesity are high and are expected to increase if nothing is done.</p><p>The objective of this thesis was to study whether prevention in early years or gastric bypass is the preference from a societal perspective as an intervention to obesity. I develop three hypothetical cohorts; status quo, effective prevention in early years and people whom develop obesity have gastric bypass surgery. The cohorts are followed from age 20 to age 64 where costs and effects are observed using a decision tree model. The results were that both gastric bypass and prevention in early years are found to be cost-effective treatments to obesity. Gastric bypass is found being more effective than a studied population-based prevention. Effective high-risk preventive methods can contribute to a higher benefit to society than a gastric bypass surgery.</p><p> </p><p>Keyword: Obesity, Gastric Bypass, Prevention</p><p> </p>

Fetman i Sverige har under de senaste två decennierna ökat kraftigt. Till följd av detta är hälsokostnaderna relaterat till fetma ansenliga och förväntas öka ytterligare om ingenting görs åt problemet. I denna studie studeras prevention och gastric bypass som alternativa behandlingsmetoder mot fetma sett ur ett samhällsekonomiskt perspektiv. Tre hypotetiska kohorter utvecklas; status quo, effektiv prevention i ungdomsåren samt individer som utvecklar svår fetma opereras med gastric bypass. Dessa kohorter följs under åldern 20-64 år där kostnader och effekter observeras med hjälp av en beslutsträdsmodell. Både gastric bypass och prevention påvisas vara kostnadseffektiva behandlingsmetoder mot fetma. Gastric Bypass visas vara mer effektiv än en studerad befolkningsinriktad preventionsåtgärd. Slutligen påvisas att effektiva högriskpreventioner kan bidra med en högre samhällsnytta än gastric bypass operationer.   Nyckelord: Fetma, Gastric Bypass, Prevention / The prevalence of obesity has increased rapidly the past two decades. As a consequence the health expenditures related to obesity are high and are expected to increase if nothing is done. The objective of this thesis was to study whether prevention in early years or gastric bypass is the preference from a societal perspective as an intervention to obesity. I develop three hypothetical cohorts; status quo, effective prevention in early years and people whom develop obesity have gastric bypass surgery. The cohorts are followed from age 20 to age 64 where costs and effects are observed using a decision tree model. The results were that both gastric bypass and prevention in early years are found to be cost-effective treatments to obesity. Gastric bypass is found being more effective than a studied population-based prevention. Effective high-risk preventive methods can contribute to a higher benefit to society than a gastric bypass surgery.   Keyword: Obesity, Gastric Bypass, Prevention

No description available.