Oral Tolerance Test Research Articles

Effect of 1,2‐Dimethyl‐3‐Hydroxypyridin‐4‐One (L1) on zinc absorption

The aim of the study was to determine the effect of L1 on zinc absorption in healthy individuals. Ten healthy volunteer individuals were included. Oral zinc tolerance test was performed first with 120 mg ZnSO4·7H2O (22.5 mg elementary zinc) and then with zinc sulfate and deferiprone (L1) at a dose of 500 mg. Plasma and urine zinc concentrations were assessed by an atomic absorption spectrophotomer. When zinc profile values during the OZTT were compared, there was only a significant increase during the 3rd hour (147 ± 6.5 μg/dl vs. 166.4 ± 13.8 μg/dl) in the zinc sulfate + L1 trial. However AUC4 values for both tests were 2.623 ± 0.193 and 2.874 ± 0.247, respectively. The difference was not significant (P > .05). Our data revealed that L1 does not have a negative effect on zinc absorption. So, we concluded that L1 and zinc can be given together orally. J. Trace Elem. Exp. Med. 11:5–9, 1998. © 1998 Wiley-Liss, Inc.

Effect of 1,2-Dimethyl-3-Hydroxypyridin-4-One (L1) on zinc absorption

The aim of the study was to determine the effect of L1 on zinc absorption in healthy individuals. Ten healthy volunteer individuals were included. Oral zinc tolerance test was performed first with 120 mg ZnSO4·7H2O (22.5 mg elementary zinc) and then with zinc sulfate and deferiprone (L1) at a dose of 500 mg. Plasma and urine zinc concentrations were assessed by an atomic absorption spectrophotomer. When zinc profile values during the OZTT were compared, there was only a significant increase during the 3rd hour (147 ± 6.5 μg/dl vs. 166.4 ± 13.8 μg/dl) in the zinc sulfate + L1 trial. However AUC4 values for both tests were 2.623 ± 0.193 and 2.874 ± 0.247, respectively. The difference was not significant (P > .05). Our data revealed that L1 does not have a negative effect on zinc absorption. So, we concluded that L1 and zinc can be given together orally. J. Trace Elem. Exp. Med. 11:5–9, 1998. © 1998 Wiley-Liss, Inc.

Pregnancy outcome of mothers with defective oral zinc tolerance test

Pregnancy outcome of four previously reported women with impaired zinc absorption was determined. These women were supplemented with zinc sulphate for 6 months. Their plasma Zn levels prior to conception were within normal levels. Of the four deliveries, all newborns were normal; only one had closed spina bifida. Our data are further evidence for a possible role of zinc metabolism, at least in some mothers with previous neural tube defects (NTD) babies. J. Trace Elem. Exp. Med. 10:153–154, 1997. © 1997 Wiley-Liss, Inc.

Responses of insulin to oral glucose and fructose loads in marginally copper-deficient rats fed starch or fructose

The purpose of this study was to assess the effects of dietary fructose either alone or in combination with marginal copper deficiency in weanling male rats exposed to their respective diets for only 2 wk. This short duration of exposure to inadequate copper intake prevents progressive morbidity brought about by increasing periods of exposure to dietary copper deprivation. Weanling male rats were fed a copper-deficient (0.6 μg Cu/g) or a copper-adequate (6.0 μg Cu/g) diet containing 62% fructose or 62% starch for 2 wk. Either an oral glucose or an oral fructose tolerance test was conducted after an overnight fast. Insulin levels were elevated by either oral glucose or oral fructose at fasting and at 30 min postload in rats fed fructose compared with those fed starch. Despite high levels of plasma, insulin blood glucose was not reduced. Marginal copper deficiency had no effect on either plasma insulin or blood glucose. Data identify fructose as the sole agent responsible for inducing adverse changes in glucose metabolism. Two weeks of fructose consumption was sufficient to produce these changes.

Clinical Aspects of Trace Elements: Zinc in Human Nutrition ‐ Assessment of Zinc Status

Because the limiting and vulnerable zinc pool has not been identified, it becomes a challenge to determine which of the many zinc pools is most susceptible to deficiency. As a consequence, defining and assessing zinc status in the individual patient is a somewhat uncertain process. Laboratory analysis of zinc status is difficult because no single biochemical criterion can reliably reflect zinc body stores. Many indexes have been examined in the hopes of discovering a method for the assessment of zinc nutriture. None of the methods currently used can be wholeheartedly recommended because they are fraught with problems that affect their use and interpretation. However, these methods remain in use for clinical and research purposes, though their benefits and drawbacks must always be acknowledged. Until an acceptable method of analysis is discovered, clinicians must rely for confirmation of zinc deficiency on a process of supplementing with zinc and observing the patient’s response. The main indexes (plasma/serum, erythrocyte, leukocyte, neutrophil, urine, hair and salivary zinc levels, taste acuity and oral zinc tolerance tests, and measurement of metallothionein levels) are reviewed. Measurement of plasma or erythrocyte metallothionein levels shows promise as a future tool for the accurate determination of zinc status.

Asymptomatic Unconjugated Hyperbilirubinemia (Gilbert Syndrome) among Saudis in Jeddah

Asymptomatic Unconjugated Hyperbilirubinemia (Gilbert Syndrome) among Saudis in Jeddah

The application of an oral zinc tolerance test to assess zinc absorption from three different dietary sources in the dog

Zinc (Zn) is a key nutrient for dogs, playing an important role in many metabolic functions. It has been estimated that 91% of the minimum maintenance requirement for Zn is needed to support hair growth. Coat condition is perceived as being important by pet owners and is thus of fundamental concern when evaluating the adequacy of a diet for dogs.Zn absorption has been shown to vary as a function of the amount and source of the Zn in the diet and as a function of the presence of elevated calcium and / or phytate levels in the diet.It has been suggested that when dietary Zn is supplied in the form of a chelate with amino acids, rather than from inorganic sources, a greater proportion of Zn is absorbed an is thus available to the animal. Further, the undesirable effects that dietary antagonists, such as calcium, exert on Zn absorption may be negated

The application of an oral zinc tolerance test to assess zinc absorption from three different dietary sources in the dog

Zinc (Zn) is a key nutrient for dogs, playing an important role in many metabolic functions. It has been estimated that 91% of the minimum maintenance requirement for Zn is needed to support hair growth. Coat condition is perceived as being important by pet owners and is thus of fundamental concern when evaluating the adequacy of a diet for dogs.Zn absorption has been shown to vary as a function of the amount and source of the Zn in the diet and as a function of the presence of elevated calcium and / or phytate levels in the diet.It has been suggested that when dietary Zn is supplied in the form of a chelate with amino acids, rather than from inorganic sources, a greater proportion of Zn is absorbed an is thus available to the animal. Further, the undesirable effects that dietary antagonists, such as calcium, exert on Zn absorption may be negated

Bioactive saponins and glycosides. I. Senegae radix. (1): E-senegasaponins a and b and Z-senegasaponins a and b, their inhibitory effect on alcohol absorption and hypoglycemic activity.

E-Senegasaponins a, b, and c were isolated from Senegae Radix, the root of Polygala senega L. var. latifolia TORREY et GRAY, together with their Z-isomers of the 4"-methoxycinnamoyl moiety, Z-senegasaponins a, b, and c. The structures of E-senegasaponins a and b and Z-senegasaponins a and b have been elucidated on the basis of chemical and physicochemical evidence, and the geometrical isomeric structure of the 4"-methoxycinnamoyl group in each saponin was found to show tautomer-like behavior in methanol solution or under irradiation with fluorescent lamps. E and Z-Senegasaponins a and b were found to exhibit potent inhibitory effects on alcohol absorption and hypoglycemic activity in the oral D-glucose tolerance tests in rats, and some structure-activity relationships of the acylated bisdesmoside-type saponins were clarified.

Elatoside E, a new hypoglycemic principle from the root cortex of Aralia elata Seem.: structure-related hypoglycemic activity of oleanolic acid glycosides.

A new inhibitor named elatosides E (which was shown to affect the elevation of plasma glucose level by oral sugar tolerance test in rats) was isolated from the root cortex of Aralia elata Seem. together with elatoside F. The structures of elatosides E and F were elucidated on the basis of chemical and physicochemical evidence. The hypoglycemic activities of oleanolic acid and nine oleanolic acid glycosides obtained from the root cortex of Aralia elata have been examined, and some structure-activity relationships have been found.

Longitudinal evaluation of glucose tolerance and insulin secretion in non‐diabetic children and adolescents with cystic fibrosis: results of a two‐year follow‐up

Thirty-two patients with cystic fibrosis and repeatedly normal fasting blood glucose underwent oral glucose tests and islet-cell antibody assessments on two occasions approximately two years apart. Fourteen patients underwent two iv glucose tolerance tests also. Although in the group as a whole mean glucose areas in response to the oral test remained substantially unmodified over the two-year period, the prevalence of glucose tolerance abnormalities increased from 37.5 to 50%. Insulin output in response to both oral and iv tolerance tests decreased over time. Worsening of insulin secretion and/or of glucose tolerance was never accompanied by deteriorating clinical status. Islet-cell antibodies were detected in no patients, even in those who developed a diabetic glucose tolerance. These results support, on a longitudinal basis, the view of a progressive impairment of B-cell function in cystic fibrosis, which may precede the onset of metabolic abnormalities and is not triggered by autoimmunity.

A standardized oral zinc tolerance test for assessment of zinc absorption in dogs.

Three oral zinc tolerance tests using increasing doses of elemental zinc (0.5, 0.75 and 1.0 mg/kg) given as zinc sulphate (ZnSO4.7H2O) were carried out in eight normal beagles. The zinc tolerance curves obtained were similar to those described in man, with the peak plasma zinc concentration occurring 2 h after dosing. There was a considerable variation between individual animals in the peak plasma zinc concentration achieved with each dose. This would appear to limit the value of a zinc tolerance test in assessing the efficiency of zinc absorption in individuals, although it may be of value in making comparisons between groups of dogs.

Relation of body fat distribution in men and degree of coronary narrowings in coronary artery disease

This study evaluates the relation between body fat distribution and severity of coronary artery disease (CAD). The study sample comprised 33 patients with angiographically demonstrated CAD and 10 angiographically normal control subjects. Body fat distribution was estimated by computed tomography and degree of coronary narrowings by angiographic score. Body weight, body mass index and total and subcutaneous abdominal adipose tissue areas showed no statistical differences in the 2 groups; visceral abdominal adipose tissue area and the visceral to subcutaneous abdominal adipose tissue area ratio were significantly higher in patients with CAD (p < 0.05). There was a significant correlation between visceral fat and triglycerides, apoprotein B and sum of glucose and insulin during glucose oral tolerance test. Sum of insulin during glucose oral tolerance test, visceral abdominal adipose tissue area and visceral/subcutaneous abdominal adipose tissue area ratio correlated significantly with severity of CAD, as evaluated by coronary score in all subjects and in CAD patients alone. Stepwise multiple regression analysis using the coronary score as the dependent variable and anthropometric and metabolic parameters as independent variables shows that in all subjects and in CAD patients alone, visceral/subcutaneous abdominal adipose-tissue area ratio entered the regression first and the sum of insulin during glucose oral tolerance test second. The results suggest that visceral abdominal adipose tissue area and visceral to subcutaneous abdominal adipose tissue area ratio may be cardiovascular risk factors.

Use of oral tolerance tests to investigate disaccharide digestion in neonatal foals.

Oral tolerance tests were performed on 13 neonatal foals to determine their ability to digest disaccharides on d 1, 3 and 5 postpartum. Foals were assigned randomly to treatments consisting of 20% (wt/vol) solutions of either maltose, lactose, or sucrose, dosed at 1 g/kg of BW, or glucose, dosed at .5 g/kg of BW. After a 2-h fast, an initial blood sample was collected via jugular catheter. Foals were administered the appropriate solution orally, and blood was collected every 15 min for 1 h and then every 30 min for 3 h. Plasma glucose increased after dosing with lactose or glucose but not with sucrose. Plasma glucose concentrations increased slightly on d 3 and 5 in foals dosed with maltose. These findings suggest that although lactose is well digested by neonatal foals, maltose is digested only slightly, and sucrose is not digested by d 5. Results of this experiment indicate that maltose and sucrose would not be suitable for inclusion in artificial diets for foals less than 1 wk old. Oral tolerance tests could be useful for determining the ability of premature or sick foals with lactose intolerance to digest alternate carbohydrate sources.

The effects of indigestible dextrin on sugar tolerance: I. Studies on digestion-absorption and sugar tolerance

It is widely acknowledged that high viscosity water-soluble dietary fibers such as pectin and guar gum affect a lowering of blood glucose levels and a reducing of insulin secretion following a sugar load. However, as dietary fibers vary in origin and in chemical properties, their physiological functions differ as well. In this study the effects of Indigestible Dextrin (PF-C), a low viscosity, water-soluble dietary fiber obtained through acid and heat-treatment of potato starch, on various aspects of sugar tolerance were examined. First, the influence of PF-C on sucrose hydrolysis was examined in rat intestinal mucosa cell homogenate confirming that PF-C did not inhibit sucrase activity. Then, in order to investigate the influence of PF-C on sugar digestion-absorption, an experiment was performed by using the everted intestinal sac of the rat in vitro. PF-C did not have an effect on glucose-transport into the serosal medium, whereas PF-C did inhibit the transport of hydrolyzed-glucose from sucrose, with no change in the hydrolysis of sucrose. Recently, Crane et al. reported that there is a specific route for hydrolyzed glucose from sucrose in glucose-absorption on the enteric surface (disaccharidase related transport system). The possibility exists that PF-C specifically affects this pathway. Further, total glucagon released into the serosal medium stimulated by both glucose and sucrose were reduced by PF-C. On the basis of these results, an oral sugar tolerance test was conducted in both rats and healthy human subjects. In male Sprague-Dawley rats (8 weeks old, 250-280g) concurrent administration of PF-C (0.6g/kg body weight) reduced an increase in plasma insulin levels with no change in glucose levels following a glucose (1.5g/kg body weight) load. Further noted were reductions in increases in both plasma glucose and insulin levels following a sucrose (1.5g/kg body weight) plus PF-C (0.6g/kg body weight) load to that of the sucrose (1.5g/kg body weight) single load. These findings reflect the above mentioned in vitro results. Moreover, in healthy male subjects the increase in both plasma insulin and glucagon-like immunoreactivity (Gut GLI) levels following a Trelan-G75 load were significantly reduced by concurrent administration of PF-C. From these observations it would appear that the effectiveness of reducing insulin secretion by PF-C results due to the decrease in sugar absorption by inhibiting the disaccharidase-related transport system.(ABSTRACT TRUNCATED AT 400 WORDS)

Influence of Weight Reduction on Plasma High-Density-Lipoprotein Cholesterol Concentrations in Severe Obesity: Interrelationships with Plasma Insulin Levels

The influence of caloric restriction and of weight loss during a weight-maintaining diet on lipid profile and in particular on high density lipoprotein (HDL) is controversial. In this study we analyzed the effect of a period of very low caloric diet (VLCD) and of a period of hypocaloric diet followed by 30 days of weight stabilization on lipoprotein levels, especially on HDL cholesterol and its subfractions (HDL2 and HDL3) and on the summated means of glucose (sigma glucose) and insulin levels (sigma IRI) after an oral tolerance test in a group of obese females. Body weight decreased significantly during the VLCD and hypocaloric diet. Total cholesterol decreased significantly after the VLCD and hypocaloric diet, but after the period of the weight-maintaining diet it was superimposable to the initial value. Very low density lipoprotein (VLDL) and low density lipoprotein (LDL) cholesterol behaved like total cholesterol. HDL2, HDL3 and HDL cholesterol decreased significantly after the period of VLCD. Then, after the hypocaloric diet the values of HDL2, HDL3 and HDL cholesterol returned towards the initial values and only after the period of the weight-maintaining diet did their values increase significantly. sigma glucose did not vary significantly at any time of the study, while sigma IRI reduced significantly both after the hypocaloric diet and the weight-maintaining diet. HDL2 and HDL cholesterol changes were found to be positively correlated to the variations of sigma IRI both at day 45 and 75 of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Research on the treatment of secondary hyperparathyroidism as a complication of chronic renal failure

The effects of internal treatment were compared with those of surgical procedures on secondary hyperparathyroidism as a complication of chronic renal failure patients in order to study their applications and problems. Maintenance hemodialysis patients complicated with 2HPT were selected as test subjects. The following internal treatment was administered. 1) Elcitonine to 6 cases and 2) Ipriflavon to 5 cases respectively and applied 3) pulse therapy of 1.25(OH)2D3 to 12 cases. On the other hand, total parathyroidectomy and autotransplantation were carried out as surgical procedures. The results of the treatment were evaluated by comparing serological data including tartrate resistant acid phosphatase (TAP) measured with the passage of time, bone scintigram findings, and change of bone mineral content (BMC) measured by single photon absorptiometry and dual photon absorptiometry. In the pulse therapy group, an oral tolerance test of 6 micrograms of 1.25(OH)2D3 was carried out to investigate its relation to long term prognosis. Furthermore, in both the pulse therapy group and PTX group, serum aluminum (A1) and delta A1 calculated by Defferoxamine (DFO) tolerance test were measured. The results are as follows. 1) In Elcitonine and Ipriflavon administration groups, increase of ALP and PTH and decrease of BMC (p less than 0.05) were recognized. 2) In the pulse therapy group, although the patients with PTH-C less than 30 ng/ml showed decrease in PTH both in short and long terms, cases with PTH-C more than 30 ng/ml kept the same level in PTH. Regardless of the change of PTH and ALP, there was no significant change observed in BMC. 3) In the PTX group, ALP/TAP ratio rose by 900% temporarily and BMC increased (p less than 0.01) in all regions measured. 4) Serum A1 and delta A1 were decreased (p less than 0.01) in PTX cases and in the pulse therapy cases in which ALP was decreased. In recent years, internal treatments on 2HPT patients have become diversified. However, exacerbation of 2HPT considered as an escape phenomenon caused the decrease in BMC after exclusive calcitonine preparatives administration. Pulse therapy, which is regarded at present as most effective in reducing PTH, ALP, did not work to increase BMC efficiently. In other word, in order to attain efficient BMC increase action, it is necessary to transfer from bone resorption phase to formative phase rapidly with drastic decrease of PTH and TAP observed in PTX.(ABSTRACT TRUNCATED AT 400 WORDS)

Oral calcium tolerance tests in pregnancy and lactation

Oral calcium tolerance tests in pregnancy and lactation

Effects of acarbose on the development of diabetes in [formula omitted] rats

This study was designed to determine whether the addition of acarbose (a dissacharidase inhibitor) to the diet can prevent or delay the development of diabetes in the BB Wor rat. Acarbose reduces postprandial glucose and insulin levels in normal and diabetic rats by delaying the absorption of carbohydrates. Data by others suggested that reduced activity of β cells renders them less prone to immunological attack. It was speculated that feeding acarbose to diabetes susceptible BB Wor rats may similarly reduce islet immunogenicity by reducing the burden on the β cells, and decrease the incidence of disease. Acarbose was added to regular chow and chow containing 15% sucrose. The rationale for using chow containing sucrose was to increase the effectiveness of acarbose, since sucrose is one of the primary carbohydrates whose digestion is blocked by acarbose. Diabetes-prone BB Wor rats were fed either regular chow (A;N = 30), regular chow plus acarbose at 40 mg 100 g chow (B;N = 30), 15% sucrose-containing chow (C;N = 30), or 15% sucrose-containing chow plus acarbose (D;N = 30). Oral chow tolerance tests, performed using 500 mg of chow, confirmed a reduction in plasma glucose and insulin values in acarbose-fed animals. The mean incidence of diabetes in groups A through D was 87%, 73%, 87%, and 93%, respectively (not significant). The mean (±SEM) ages (days) of onset of diabetes in animals fed diets A through D were 88 ± 2.1, 90 ± 3.2, 86 ± 1.9, and 91 ± 2.6, respectively. Though these values were insignificantly different from each other, there was a slight, but statistically insignificant, delay in onset of diabetes in animals developing disease after approximately 80 days of age in the group fed regular chow plus acarbose (B), compared to control (A). Food intake in all four groups was comparable, when controlling for sex. There was no significant effect of acarbose on body weights in female rats fed either the regular or high-sucrose chows, but there was a significant ( P <.01) reduction in body weights of male rats receiving acarbose compared to those not receiving the drug. Acarbose had no effect on stabilizing declining body weights of animals that became diabetic during the course of the study, regardless of whether they had been fed acarbose up to that point or not. However, feeding acarbose to diabetic animals seemed to stabilize their plasma glucose values. Removal of acarbose from the diets of diabetic animals fed high-sucrose chow resulted in a marked elevation of their plasma glucose values compared with animals that remained on their acarbose diets ( P < .05). It is concluded that acarbose does not prevent diabetes in the BB Wor rat, but it appeared to moderate the hyperglycemia that developed in diabetic animals.

Ingestion of Carbohydrates Varying in Complexity Produce Differential Brain Responses

Variations in the complexity of carbohydrate substances were studied with respect to their differential effects on brain function. Glucose, sucrose, fructose and corn starch were each administered as part of an oral carbohydrate tolerance test during 17 test trials. Brain EEG changes and blood glucose levels were monitored concurrently throughout a 5 hour period. The glucose solution produced more substantial EEG effects than the other three carbohydrate solutions. Absolute blood glucose level was the primary determinant of electrocortical changes found predominantly in the left parietal-occipital and left temporal cortical regions. Implications for the study and evaluation of cognitive function were discussed.