AIM: To evaluate the prevalence of lactose intolerance (LI) following a load of 12.5 g in patients diagnosed as high-grade malabsorbers using the hydrogen breath test (HBT)-25.METHODS: Ninety patients showing high-gra...AIM: To evaluate the prevalence of lactose intolerance (LI) following a load of 12.5 g in patients diagnosed as high-grade malabsorbers using the hydrogen breath test (HBT)-25.METHODS: Ninety patients showing high-grade malabsorption at HBT-25 were submitted to a second HBT with a lactose load of 12.5 g.Peak hydrogen production,area under the curve of hydrogen excretion and occurrence of symptoms were recorded.RESULTS: Only 16 patients (17.77%) with positive HBT-25 proved positive at HBT-12.5.Hydrogen production was lower as compared to HBT-25 (peak value 21.55 parts per million (ppm) ± 29.54 SD vs 99.43 ppm ± 40.01 SD; P < 0.001).Symptoms were present in only 13 patients.The absence of symptoms during the high-dose test has a high negative predictive value (0.84) for a negative low-dose test.The presence of symptoms during the first test was not useful for predicting a positive low-dose test (positive predictive value 0.06-0.31).CONCLUSION: Most patients with a positive HBT-25 normally absorb a lower dose of lactose and a strict lactose restriction on the basis of a "standard" HBT is,in most instances,unnecessary.Thus,the 25 g lactose tolerance test should probably be substituted by the 12.5 g test in the diagnosis of LI,and in providing dietary guidelines to patients with suspected lactose malabsorption/intolerance.展开更多
Drink tests are advocated as an inexpensive, nonivasive technique to assess gastric function in patients with a variety of upper digestive symptoms. Many patients with dyspeptic complaints will achieve satiation or de...Drink tests are advocated as an inexpensive, nonivasive technique to assess gastric function in patients with a variety of upper digestive symptoms. Many patients with dyspeptic complaints will achieve satiation or develop symptoms at ingested volumes below those typically required to achieve these endpoints in controls. Substantial variation in test performance exists and a greater degree of standardization is required. Additionally, it remains unclear exactly what drink tests measure as correlations with measures of gastric sensation, accomodation and emptying are modest at best. Finally, results of drink tests do not guide therpay. At present, these tests are best reserved for research studies and are not advocated for use in clinical practice.展开更多
AIM:To investigate the relationship between plasma acylated ghrelin levels and the pathophysiology of functional dyspepsia.METHODS:Twenty-two female patients with functional dyspepsia and twelve healthy volunteers wer...AIM:To investigate the relationship between plasma acylated ghrelin levels and the pathophysiology of functional dyspepsia.METHODS:Twenty-two female patients with functional dyspepsia and twelve healthy volunteers were recruited for the study.The functional dyspepsia patients were each diagnosed based on the Rome Ⅲ criteria.Eligible patients completed a questionnaire concerning the severity of 10 symptoms.Plasma acylated ghrelin levels before and after a meal were determined in the study participants using a commercial human acylated enzyme immunoassay kit;electrogastrograms were performed for 50 min before and after a standardized 10-min meal containing 265 kcal.RESULTS:There were no significant differences in plasma acylated ghrelin levels between healthy volunteers and patients with functional dyspepsia.However,in patients with functional dyspepsia,there was a negative correlation between fasting plasma acylated ghrelin levels and the sum score of epigastric pain(r =-0.427,P = 0.047) and a positive correlation between the postprandial/fasting plasma acylated ghrelin ratio and the sum score of early satiety(r = 0.428,P =0.047).Additionally,there was a negative correlation between fasting acylated ghrelin plasma levels and fasting normogastria(%)(r =-0.522,P = 0.013).Interestingly,two functional dyspepsia patients showed paradoxically elevated plasma acylated ghrelin levels after the meal.CONCLUSION:Abnormal plasma acylated ghrelin levels before or after a meal may be related to several of the dyspeptic symptoms seen in patients with functional dyspepsia.展开更多
Investors have traditionally been viewed as economically rational individuals who make decisions based on all available information. They have been assumed to use probability functions to arrive at the most optimal de...Investors have traditionally been viewed as economically rational individuals who make decisions based on all available information. They have been assumed to use probability functions to arrive at the most optimal decision. More recent studies propose that investors are irrational and systematically overreact to good and bad information events. The concept of the rational investor has been supported by among others Efficient Market Hypothesis and Modem Portfolio Theory. Other studies opposed to the notion of rational investors have identified psychological biases that influence decision making process of an investor, and leading them to make irrational decisions. Several anomalies have been identified that deviate from rational behavior. The objective of this paper was to test for investor rationality for companies listed at the Nairobi Stock Exchange. This paper tested overreaction by investors to news and performance of companies listed at the Nairobi Stock Market as an anomaly that has been proven in other markets. The test involved forming companies into two portfolios, one of extreme good performers and the other of extreme poor performers during the base year. Performance of these portfolios was analyzed for a nine year period from the year of portfolio formation. The results are consistent with the notion of overreaction, showing that investors overreact to both good and bad news. Over the study period the loser portfolio outperformed the winner portfolio by about 35.92%. This confrere that investors are irrational and make decisions based on some biases.展开更多
文摘AIM: To evaluate the prevalence of lactose intolerance (LI) following a load of 12.5 g in patients diagnosed as high-grade malabsorbers using the hydrogen breath test (HBT)-25.METHODS: Ninety patients showing high-grade malabsorption at HBT-25 were submitted to a second HBT with a lactose load of 12.5 g.Peak hydrogen production,area under the curve of hydrogen excretion and occurrence of symptoms were recorded.RESULTS: Only 16 patients (17.77%) with positive HBT-25 proved positive at HBT-12.5.Hydrogen production was lower as compared to HBT-25 (peak value 21.55 parts per million (ppm) ± 29.54 SD vs 99.43 ppm ± 40.01 SD; P < 0.001).Symptoms were present in only 13 patients.The absence of symptoms during the high-dose test has a high negative predictive value (0.84) for a negative low-dose test.The presence of symptoms during the first test was not useful for predicting a positive low-dose test (positive predictive value 0.06-0.31).CONCLUSION: Most patients with a positive HBT-25 normally absorb a lower dose of lactose and a strict lactose restriction on the basis of a "standard" HBT is,in most instances,unnecessary.Thus,the 25 g lactose tolerance test should probably be substituted by the 12.5 g test in the diagnosis of LI,and in providing dietary guidelines to patients with suspected lactose malabsorption/intolerance.
文摘Drink tests are advocated as an inexpensive, nonivasive technique to assess gastric function in patients with a variety of upper digestive symptoms. Many patients with dyspeptic complaints will achieve satiation or develop symptoms at ingested volumes below those typically required to achieve these endpoints in controls. Substantial variation in test performance exists and a greater degree of standardization is required. Additionally, it remains unclear exactly what drink tests measure as correlations with measures of gastric sensation, accomodation and emptying are modest at best. Finally, results of drink tests do not guide therpay. At present, these tests are best reserved for research studies and are not advocated for use in clinical practice.
文摘AIM:To investigate the relationship between plasma acylated ghrelin levels and the pathophysiology of functional dyspepsia.METHODS:Twenty-two female patients with functional dyspepsia and twelve healthy volunteers were recruited for the study.The functional dyspepsia patients were each diagnosed based on the Rome Ⅲ criteria.Eligible patients completed a questionnaire concerning the severity of 10 symptoms.Plasma acylated ghrelin levels before and after a meal were determined in the study participants using a commercial human acylated enzyme immunoassay kit;electrogastrograms were performed for 50 min before and after a standardized 10-min meal containing 265 kcal.RESULTS:There were no significant differences in plasma acylated ghrelin levels between healthy volunteers and patients with functional dyspepsia.However,in patients with functional dyspepsia,there was a negative correlation between fasting plasma acylated ghrelin levels and the sum score of epigastric pain(r =-0.427,P = 0.047) and a positive correlation between the postprandial/fasting plasma acylated ghrelin ratio and the sum score of early satiety(r = 0.428,P =0.047).Additionally,there was a negative correlation between fasting acylated ghrelin plasma levels and fasting normogastria(%)(r =-0.522,P = 0.013).Interestingly,two functional dyspepsia patients showed paradoxically elevated plasma acylated ghrelin levels after the meal.CONCLUSION:Abnormal plasma acylated ghrelin levels before or after a meal may be related to several of the dyspeptic symptoms seen in patients with functional dyspepsia.
文摘Investors have traditionally been viewed as economically rational individuals who make decisions based on all available information. They have been assumed to use probability functions to arrive at the most optimal decision. More recent studies propose that investors are irrational and systematically overreact to good and bad information events. The concept of the rational investor has been supported by among others Efficient Market Hypothesis and Modem Portfolio Theory. Other studies opposed to the notion of rational investors have identified psychological biases that influence decision making process of an investor, and leading them to make irrational decisions. Several anomalies have been identified that deviate from rational behavior. The objective of this paper was to test for investor rationality for companies listed at the Nairobi Stock Exchange. This paper tested overreaction by investors to news and performance of companies listed at the Nairobi Stock Market as an anomaly that has been proven in other markets. The test involved forming companies into two portfolios, one of extreme good performers and the other of extreme poor performers during the base year. Performance of these portfolios was analyzed for a nine year period from the year of portfolio formation. The results are consistent with the notion of overreaction, showing that investors overreact to both good and bad news. Over the study period the loser portfolio outperformed the winner portfolio by about 35.92%. This confrere that investors are irrational and make decisions based on some biases.
