Breakfast, plasma glucose and beta-hydroxybutyrate, body mass index and academic performance in children from Extremadura, Spain

OBJECTIVES

Nutritional aspects of breakfast, plasma levels of glucose and beta-hydroxybutyrate, body mass index and academic performance have been studied in urban and rural children (Extremadura, Spain).

METHODS

Representative samples of schoolchildren (3 to 12 years old, random cluster-sampling in schools).

RESULTS

Children's mean caloric intake with breakfast was 331 kcal. Rural population ingested more carbohydrates (46,9 +/- 12,3% versus 43,3 +/- 13,2% of the total caloric intake) and fewer lipids (40,5 +/- 11,8% versus 43,9 +/- 12,8% of the total caloric intake) than the urban population. Academic performance was significantly better in the children inhabiting the rural zone than in those of the urban zone. The glycaemia was higher in the urban than in the rural children, and that the contrary was the case for the beta-hydroxybutyrate values. Neither glucose nor beta-hydroxybutyrate levels were correlated with academic performance values. BMI was significantly increased in the urban versus rural children.

CONCLUSION

The present results emphasize the importance of breakfast and life style in the weight and the academic performance of children.

White bean amylase inhibitor administered orally reduces glycaemia in type 2 diabetic rats

A purified pancreatic alpha-amylase inhibitor (alpha-AI) from white beans (Phaseolus vulgaris) was administered orally (100 mg/kg body weight dissolved in 9 g NaCl/l) for 22 d to non-diabetic (ND) and type 2 diabetic (neonatal diabetes models n0-STZ and n5-STZ) male Wistar rats. Mean glycaemia (mmol/l) declined from day 4 of the alpha-AI administration in ND rats (5.48 (sem 0.08) v. 4.39 (sem 0.13); P<0.05), n0-STZ diabetic rats (7.94 (sem 0.42) v. 5.56 (sem 0.32); P<0.01) and n5-STZ diabetic rats (17.34 (sem 2.58) v. 11.93 (sem 1.96)), until the end of treatment: ND (5.22 (sem 0.21) v. 3.97 (sem 0.06); P<0.01); n0-STZ (8.10 (sem 0.19) v. 5.21 (sem 0.30); P<0.01); and n5-STZ (16.36 (sem 2.14) v. 7.69 (sem 1.34); P<0.01). There was a decrease in water intake (ml/d) in the alpha-AI-treated diabetic rats: n0-STZ (30 (sem 0.10) v. 22 (sem 1.50); P<0.01) and n5-STZ (76 (sem 5.04) v. 57 (sem 4.85); P<0.01). Food intake (g/d) decreased in all three groups: ND (23 (sem 0.31) v. 20 (sem 0.03); P<0.05); n0-STZ (22 (sem 0.55) v. 16 (sem 0.98); P<0.01); and n5-STZ (31 (sem 0.58) v. 23 (sem 1.20); P<0.01). The enterocyte sucrase and maltase activities (U/g proteins) were high (P<0.01) in the untreated diabetic rats, n0-STZ (45 (sem 4) and 152 (sem 10), respectively) and n5-STZ (67 (sem 12) and 151 (sem 10), respectively) with respect to the ND rats (24 (sem 2) and 74 (sem 10), respectively). After alpha-AI treatment, enzyme activities declined in both diabetic rats, n0-STZ (21 (sem 2) and 85 (sem 11); P<0.01) and n5-STZ (28 (sem 7) and 75 (sem 19); P<0.05), to values close to those in the ND rats. In conclusion, alpha-AI significantly reduced glycaemia in both the ND and diabetic animals and reduced the intake of food and water, and normalized the elevated disaccharidase levels of the diabetic rats.

Hypoglycaemic and anorexigenic activities of an alpha-amylase inhibitor from white kidney beans (Phaseolus vulgaris) in Wistar rats

An inhibitor of alpha-amylase was isolated and purified from an extract of white kidney beans (Phaseolus vulgaris). The acute oral administration of the inhibitor (50 mg/kg body weight) to adult Wistar rats together with a starch load (2 g/kg body weight suspended in NaCl (9 g/l)) reduced the increase in glycaemia over the basal value (NaCl, 222 (SEM 49); inhibitor, 145 (SEM 16) mmol/l x 180 min; P<0.05) without modifying the insulin response. On administering the inhibitor orally (50 mg/kg body weight dissolved in NaCl (9 g/l)) for 21 d to rats fed on a standard diet, a decline was observed in the glycaemia values on day 0 (NaCl, 5.53 (SEM 0.12); inhibitor, 5.25 (SEM 0.16) mmol/l) relative to those obtained on days 10 (NaCl, 5.00 (SEM 0.14); inhibitor, 4.60 (SEM 0.08) mmol/l; P<0.05) and 21 (NaCl, 5.22 (SEM 0.22); inhibitor, 4.50 (SEM 0.12) mmol/l; P<0.01) of treatment, without modifying the plasma concentration of insulin. There was found to be a significant anorexigenic action of the inhibitor; there was reduced food intake (NaCl, 23.07 (SEM 0.31); inhibitor, 19.50 (SEM 0.49) g/d; P<0.01), a reduced weight gain (NaCl, 52 (SEM 3); inhibitor, -1.33 (SEM 8.9) g/21 d; P<0.01), as well as changes in the activity of some intestinal enzymes such as maltase (NaCl, 87 (SEM 7); inhibitor, 127 (SEM 11) U/g proteins; P<0.05). The present study has shown, for the first time, that the prolonged administration of an alpha-amylase inhibitor reduces blood glucose levels and body-weight gain in Wistar rats.

Vitamins and mineral intake in elderly people from Extremadura

To evaluate the vitamin and mineral consumption of a group of elderly people of the Comunidad of Extremadura. 122 subjects 62.5+/-5.3 years (64 women, 57 men) responded to a survey on their food intake the day before. The vitamin and mineral intake was calculated using a computer program from the University of Granada. We found no statistically significant differences by gender in the intake of the following vitamins: niacin (24.5+/-10.1 vs 25.6+/-9.7 mg/day), B1 (1.6+/-0.6 vs 1.7+/-0.6 mg/day), B6 (1.7+/-0.6 vs 1.8+/-0.5 mg/day), C (129.5+/-82.1 vs 158.1+/-97.6 mg/day), D (4.4+/-7.5 vs 3.8+/-6.5 microg/day), E (7.8+/-4.1 vs 8.1+/-3.8v mg/day), and folic acid (326.6+/-164.0 vs 383.1+/-215.3 microg/day). We did find statistically significant differences in the intake of the vitamins: A (582.2+/-299.6 vs 771.8+/-602.2 microg/day, p<0.05), B12 (23.4+/-20.3 vs 13.1+/-12.1 microg/day, p<0.001) and B2 (1.6+/-0.4 vs 1.8+/-0.5 mg/day, p<0.05). With respect to mineral intake, we found no statistically significant differences by gender in the intake of the following minerals: calcium (1046.8+/-276.9 vs 1088.9+/-307.7 mg/day), iron (20.2+/-6.6 vs 18.5+/-8.6 mg/day), iodine (73.6+/-37.9 vs 73.8+/-41.1 mg/day), potassium (2804.6+/-1088 vs 2837.5+/-1035.8 mg/day), magnesium (405.4+/-155.3 vs 366.5+/-141.3 mg/day), phosphorus (1407.4+/-408.6 vs 1317.2+/-447.2 mg/day) and zinc (8.9+/-3.3 vs 8.0+/-2.7 mg/day). We found a statistically significant difference (p<0.05) for sodium (2124.9+/-1049.5 mg/day in men and 1728.4+/-992.5 mg/day in women). Our results showed an intake less than the RDA of vit.A, while the vit.B12 intake was greater than the RDA. The intake of the other parameters fitted the recommended values.

Morphological and enzymatic changes of the small intestine in an n0-STZ diabetes rat model

Summary. Many studies have shown that experimental type 1 diabetes causes morphological, functional, and metabolic alterations in the small intestine. The more frequent form of the disease, type 2 diabetes, however, has been less studied. Here the influence of diabetes on the functionality of the small intestine was studied in an experimental diabetes model, with a certain degree of residual insulin secretion, specifically in the n0-STZ model. - The diabetic rats in this model were found to have glycaemia levels higher than in the controls (8.82 +/- 0.27 and 6.18 +/- 0.18 mmol/L; p < 0.01), while their plasma insulin levels were lower than in the control rats (2.65 +/- 0.32 and 3.60 +/- 0.25 ng/ml; p < 0.05). Although there were no significant variations in body weight between the two groups, both the weight and the length of the intestine were significantly greater (p < 0.05) in the diabetic rats than in the controls. The sucrase and maltase activities were greater (p < 0.01) in the proximal intestine of the diabetic rats (94 +/- 8 and 234 +/- 12 mU/mg protein, respectively) than in the control rats (50 +/- 2 and 149 +/- 20 mU/mg protein, respectively). The 6-phosphofructo-1-kinase activity (mU/mg proteins) was less (p < 0.05) in the proximal and distal intestine of the diabetic rats (160 +/- 40 and 80 +/- 20, respectively) than in the controls (280 +/- 30 and 230 +/- 30, respectively). No significant differences were observed in the lactate dehydrogenase or active and total pyruvate dehydrogenase measured in the distal and proximal intestine of control and diabetic rats. In conclusion, our results show that experimental diabetes (n0-STZ model) similar to human type 2 diabetes produces certain morphological and enzymatic alterations which affect the digestion and absorption of carbohydrates and the intestinal metabolism of glucose. These alterations may contribute to producing the post-prandial hyperglycaemia which characterizes diabetes.

Hypoglycaemic activity of an aqueous extract from ficus carica (fig tree) leaves in streptozotocin diabetic rats

To investigate the hypoglycaemic activity of Ficus carica leaf aqueous extract, a decoction was administred to rats in lieu of drinking water for three weeks. The groups were: untreated non-diabetic (n = 13), untreated diabetic (n = 13), treated non-diabetic (n =13) and treated diabetic (n = 13) animals. The extract decreased (p &lt; 0.025) plasma glucose in diabetic (27.9 ± 4.5 mmol/L to 19.6 ± 9.9 mmol/L) while not in normal rats. Plasma insulin levels were decreased by treatment (p &lt; 0.05) in non-diabetic rats from 4.9± 1.6 ng/mL to 3.3 ± 1.2 ng/mL. Glucose uptake (µmol/min) by rat hindquarters perfused was: 5.9 ± 2.2 (untreated non-diabetic rats), 4.8 ± 2.3 (treated non-diabetic rats, p &lt; 0.05 vs. untreated non-diabetic rats), 2.0 ± 2.0 (untreated diabetic rats, p &lt; 0.01 vs. untreated non-diabetic rats) and 4.1 ± 3.6 (treated diabetic rats) in absence of insulin; 7.0 ± 1.7 (untreated non-diabetic rats), 8.3 ± 0.8 (treated non-diabetic rats, p &lt; 0.05 vs. untreated non-diabetic rats), 5.0 ± 1.6 (untreated diabetic rats, p &lt; 0.05 vs. untreated non-diabetic rats) and 6.4 ± 2.4 (treated diabetic rats) in presence of insulin. Lactate released was lower in untreated diabetic vs. untreated non-diabetic rats. Thus, Ficus carica extract showed a clear hypoglycaemic effect in diabetic rats. Such an effect cannot be mediated by an enhanced insulin secretion, so an as yet undefined insulin-like peripheral effect, may be suggested.

[Calcium intake among school children in Badajoz]

BACKGROUND

The intake of calcium has been studied in the diet of adolescents from a school in Badajoz (Spain) determining their BMI and their living habits (sport, consumption of tobacco and alcohol).

METHODOLOGY

By means of an aleatory sampling, a sample n was selected = 207 (49.76% males and 50.24 females) with an average age of 14.14 +/- 2.08 years. They were weighed and measured to calculate their BMI. A questionnaire was carried out on consumption of products rich in calcium: milk and dairy produce, vegetables, fruit, chied fruits. The statistical analysis was carried out by means of Student t and ANOVA.

RESULTS

The results was BMI < 25 (thin or standard) in 86.47%; BMI 25-30 (overweight) in 10.63% and BMI > 30 (overweight) 2.9%. The consumption of daily calcium was of 1304 +/- 702 g/ppd, higher (p < 0.001) in boys (10.45 +/- 5.51) than in girls (7.82 +/- 3.84). There is not correlation between BMI and calcium consumption. The boys observe the NIH recommendations. But girls usually don't. Milk products provide 87% of the consumed calcium. The boys who practice some sports consume 9.88 +/- 5.23 g/pps, the other ones 7.09 +/- 2.95 g/pps.

CONCLUSIONS

1. The weekly intake of calcium by surveyed students is 9.13 g/pps, smaller in girls than in boys. 2. Milk products provide 87% of the consumed calcium. 3. A 10.63% of them is overweight and a 2.9% is very overweight. 4. A 10.63% usually smokes and a 20.29% consumes alcohol. 5. A 26.27% doesn't practice any sports and consumes less calcium (p < 0.001) than the recommended quantity.

Hypotriglyceridaemic activity of Ficus carica leaves in experimental hypertriglyceridaemic rats

A model of hypertriglyceridaemia in rats is described, which was used to investigate the hypolipidaemic effect of an intraperitoneal (i./p.) administration of a Ficus carica leaf decoction. Hypertriglyceridaemia was induced in rats following the protocol: a fasting period of 22 h, 2 h of oral (p.o.) administration of 20% emulsion of longchain triglycerides (LCT emulsion), both repeated once. The plasma triglyceride and total cholesterol levels obtained 2 h after the protocol were 5.7 +/- 2.5 mmol/L (p < 0.0001 vs basal levels) and 1.7 +/- 0.3 mmol/L, respectively, n = 10. The new model was used to test the hypotriglyceridaemic effect of a single dose of Ficus carica (fig tree) leaf decoction administered i./p. (50 g dry wt/kg body wt). After the i.p. injection of serum saline (control group, n = 10) or Ficus carica extract (group A, n = 10), plasma triglyceride levels in the control group and group A were 5.9 +/- 2.9 mmol/L and 5.5 +/- 2.9 mmol/L just after the LCT emulsion protocol; 4.7 +/- 2.7 mmol/L and 0.9 +/- 0.4 mmol/L, p < 0.005, 60 min after the LCT protocol; and 3.6 +/- 2.9 mmol/L and 1.0 +/- 0.4 mmol/L, p < 0.05, 90 min after the LCT protocol. The plasma total cholesterol levels, which were not modified in our experimental model, showed no significant differences in relation to baseline levels in the presence or absence of Ficus carica treatment either. The clearly positive results suggest the presence in the fig leaf decoction of a compound or compounds that influence lipid catabolism.

Mesenteric arteriovenous differences in glucose, lactate and insulin concentrations in rats and humans

The present study was aimed to investigate the mesenteric arteriovenous differences in blood glucose and lactate and plasma insulin in humans (n=8) and rats (n=10). Arterial (abdominal aorta) and mesenteric vein blood glucose and lactate (enzymatic methods) and plasma insulin concentrations (radioimmunoassay) were measured in patients during abdominal surgery and in normal rats. Blood glucose levels were significantly (p < 0.05) higher in the abdominal aorta than in the mesenteric vein in both rats (9.2+/-1.0 vs 7.5+/-0.8 mmol/l) and humans (10.4+/-2.9 vs 8.5+/-2.7 mmol/l). Blood lactate levels were higher (p < 0.05) in the mesenteric vein in both rats (3.7+/-1.3 vs 2.8+/-0.9 mmol/l) and humans (0.7+/-0.23 vs 0.1+/-0.05 mmol/l). Plasma insulin concentrations were identical in the aorta or mesenteric vein in both rats (314.4+/-162.0 vs 311.4+/-94.2 pmol/l) and humans (62.4+/-43.2 vs 61.8+/-48.0 pmol/l). In conclusion, both rat and human intestine retained a high proportion of arterially administered glucose and released lactate under the studied conditions.

Effect of miglitol administration to non-insulin-dependent diabetic rats

1. The effect of the acute or chronic oral administration of miglitol (Bay M 1099 alpha-glucosidase inhibitor) to non-insulin-dependent diabetic rats was studied. 2. The acute oral administration of miglitol (10 mg/kg b.w.) reduced significantly the increment of blood glucose after oral maltose (2 g/kg b.w.) overload (364 +/- 58 and 205 +/- 12 mmol/90 min, without and with miglitol respectively; P < 0.05). 3. Under chronic oral administration of miglitol (10 mg/kg b.w.), two days after the start of treatment the blood glucose dropped from 7.53 +/- 9.59 to 4.40 +/- 5.50 mmol/l. The plasma insulin, cholesterol, or triglycerides levels were not modified. 4. A significant reduction (P < 0.01) in water and food intake was observed. Normal rats values were not affected by miglitol treatment.

Hypoglycemic action of an oral fig-leaf decoction in type-I diabetic patients

The effect of a decoction of fig leaves (Ficus carica), as a supplement to breakfast, on diabetes control was studied in insulin-dependent diabetes mellitus (IDDM) patients (six men, four women, age 22-38 years, body mass index (BMI): 20.8 +/- 3.0 kg/m2, HbA1c 7.6 +/- 0.9% with a mean duration of diabetes of 9 +/- 6.3 years). The patients were managed with their usual diabetes diet and their twice-daily insulin injection. During the first month, patients were given a decoction of fig leaves (FC) and during the next month a non-sweet commercial tea (TC). The patients were divided into two groups (n = 5) with random allocation and cross-over design. A standard breakfast was given at the beginning and end of each month-run. C-peptide, 2 h pre- and post-prandial glycemia, HbA1c, cholesterol, lipid fractions and hematology data, were analyzed during each visit. Glycemic profiles (7/day per week) were recorded by patients. Only two patients had intolerance dropout. Post-prandial glycemia was significantly lower during supplementation with FC 156.6 +/- 75.9 mg/dl versus TC 293.7 +/- 45.0 mg/dl (P < 0.001) without pre-prandial differences 145.0 +/- 41.5 and 196.6 +/- 43.2 mg/dl, respectively. Medium average capillary profiles were also lower in the two sub-groups of patients during FC 166.7 +/- 23.6 mg/dl, P < 0.05 and 157.1 +/- 17.0 mg/dl versus TC 245.8 +/- 14.2 mg/dl and 221.4 +/- 27.3 mg/dl. Average insulin dose was 12% lower during FC in the total group. The addition of FC to diet in IDDM could be of help to control postprandial glycemia.

Individual housing influences certain biochemical parameters in the rat

Individual housing has been reported to modify animal behaviour. The present study compares the plasma levels of glucose, triglycerides and total cholesterol, weight, and food and water intake in two groups of female rats. Group A: 10 rats who remained grouped in two cages for 21 days; and Group B: 10 rats housed in two cages for 7 days, then isolated in individual cages from day 8 to day 15, and finally grouped together again for the last 7 days of the study. The results showed that the plasma values of glucose declined (P < 0.05) in the Group B rats when they had been returned to group condition (4.79 +/- 0.72 mM) than when they had been isolated (5.45 +/- 0.94 mM). Plasma triglyceride levels were lower (P < 0.05) in isolated rats (0.70 +/- 0.26 mM) than in any determination of the grouped rats. Group B: 1st week 1.21 +/- 0.21 mM, 3rd week 0.88 +/- 0.20 mM; and Group A: 1.22 +/- 0.20, 0.96 +/- 0.16, and 0.96 +/- 0.36 mM, in the first, second, and third week, respectively. There were no statistically significant differences in total cholesterol values as a function of the individual housing of animals. While there was no weight difference between the two groups of rats that could be ascribed to individual housing, there was a statistically significant increase (P < 0.05) in the food intake of isolated rats (17.5 +/- 3.2 g) with respect to values in the same Group B animals when they were housed together (1st week, 16.6 +/- 2.8 g; 3rd week, 16.8 +/- 3.1 g). These results therefore confirm that individual housing of female rats provoke variations in certain biochemical parameters, and that if this is not taken into account in performing different scientific studies, it could give rise to unreliable or even dubious results.

In vitro study of the effect of miglitol on carbohydrate digestion and intestinal metabolism in normal and non-insulin-dependent diabetic rats

The effect of miglitol was studied (20 mg/kg body weight), administered intraduodenally alone or together with maltose, on the absorption and intestinal metabolism of glucose during its translocation from the lumen of the intestine to the blood, using in vitro perfused preparations of complete small intestine-pancreas, proximal small intestine alone, or distal small intestine alone, isolated from normal and non-insulin-dependent diabetic rats. In the absence of a luminal administration of maltose in normal rats, the glucose uptake from the vascular perfusate was greater in the presence (0.52 +/- 0.04 mmol/h) than in the absence (0.39 +/- 0.02 mmol/h) of miglitol (p < 0.05). In diabetic rats, no significant variations were observed in glucose uptake from the vascular perfusate as an effect of miglitol, but the glucose uptake in the presence of this drug was significantly less (p < 0.05) than that observed in normal rats. Portal lactate was significantly greater (p < 0.05) in diabetic than in normal rats and, after administration of miglitol, rose in both normal and diabetic rats, the rise being significantly greater in normal than in diabetic rats (p < 0.01). When maltose was administered luminally (2 g/kg body weight), the values of portal glucose in both normal and diabetic rats were significantly less in the presence of miglitol in the complete as well as in the distal and proximal small intestine preparations (p < 0.05); the glucose uptake from luminal administered maltose was greater in the presence of miglitol in diabetic (p < 0.05) and in normal (p < 0.05) rats except in the complete small intestine of normal rats; and no significant differences were observed in portal lactate levels between normal and diabetic rats in the presence of miglitol. In conclusion, our results show that miglitol administered luminally at the doses employed here, as well as reducing the transport of glucose from the lumen of the intestine into the blood supply, significantly stimulate intestinal glucose metabolism.

Changes in plasma enzyme activities in professional racing cyclists

OBJECTIVE

To reports changes in plasma levels in professional racing cyclists.

METHODS

Plasma levels of the intracellular enzymes aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transpeptidase, lactate dehydrogenase, and alkaline phosphatase were measured resting and after exercise in professional cyclists participating in two road races: Vuelta Ciclista a Valencia (800 km, beginning of the cyclist season), and the top rank race Vuelta a España (2700 km, at the end of cyclist season).

RESULTS

A significant increase in plasma aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase was observed at the end of the race over the corresponding paired start values (P < 0.05). The increase in plasma lactate dehydrogenase after the race was only statistically significant (P < 0.05) in the Vuelta a España. The longer the duration of the cycle tour race, the greater were the increases in aspartate aminotransferase and alanine aminotransferase levels. The high levels returned to their start values during the overnight resting period.

CONCLUSIONS

The presence of these enzymes in the blood is probably due to mechanically damaged muscle cells leaking their contents into the interstitial fluid.

Experimental streptozotocin-reduced diabetes and intestinal glucose metabolism in the rat, in vivo and in vitro

The intestine has a high glycolytic activity, but its metabolic role could be altered in diabetes mellitus. The aim of the present work was to investigate in vivo the glucose retained and the lactate produced by the intestine of normal and diabetic rats and in vitro the effect of different arterial glucose concentrations on glucose utilization and lactate, alanine, and pyruvate production in normal and diabetic rats when the glucose is supplied to the intestine exclusively via the vascular route. In vivo, the normal and diabetic rats retained similar percentages of the arterially supplied glucose (14.7 +/- 2.4, respectively). In vitro, when the preparations were perfused under hyperglycemic conditions, the glucose consumed, as a fraction of the quantity infused, was significantly lower (P < 0.05) in the diabetic (247.0 +/- 22.8 mumol/mmol infused glucose) than in normal (315 +/- 16.3 mumol/mmol infused glucose rats) rats. The lactate produced was significantly higher in diabetic than in normal rats whether the preparations were perfused under isoglycemic (P < 0.01; 1916.4 +/- 124.0 vs vs 1284 +/- 67.7 mumol/mmol consumed glucose) or hyperglycemic (P < 0.05; 1356.4 +/- 199.7 vs 898.0 +/- 87.3 mumol/mmol consumed glucose) conditions. There was significantly (P < 0.05) greater alanine release from the diabetic (123.7 +/- 21.8 mumol/mmol consumed glucose) than from the normal (40.7 +/- 10.3 mumol/mmol consumed glucose) rat preparations perfused under isoglycemic conditions.

[A descriptive clinical study of a type of arthritis in beekeepers of the Badajoz area of La Siberia Extremeña]

BACKGROUND

The appearance of episodes of arthritis has been detected in beekeepers in the Siberia Extremadura (Spain) related to working with the hives. This present work describes the clinical features of such arthritic syndrome.

METHODS

Sixty cases were selected at random from a previous epidemiological study to undergo a clinical protocol that included, anamnesis, physical signs, haematological, biochemical and immunological analyses, and radiological exploration of hands, wrists, feet, and pelvis.

RESULTS

The picture is characterized by episodes of oligoarthritis associated with bee-stings in the affected joints or nearby. The most frequent radiologic lesions are pinched articular lines, sclerosis, and the presence of geodes. Analytically, there was frequent eosinophilia, abnormalities in haemostasis tests, and a rise in serum alkaline phosphatase.

CONCLUSIONS

An acute inflammatory oligoarthritis of unknown cause has been described which affects the hands asymmetrically, and which is found in beekeepers in relation to their work with the hives. It occasionally involves into a chronic localized arthropathy capable of provoking ankylosis and permanent articular disability.

HDL-cholesterol increase associated to triglycerides degradation in vitro

The effect of muscle tissue from rats trained by swimming on the extracellular degradation of triglyceride (TG) rich particles has been studied in vitro. During incubation, there is a progressive decline of the TG concentration in the incubation medium. At the end of the incubation period (90 min), a significantly reduction in the TG levels (p < 0.05) is associated with a significant increase in the high-density lipoprotein (HDL) cholesterol level (p < 0.005). There are no significant changes in total cholesterol levels. The correlation of the TG decline with the HDL-cholesterol increase is significant (r = 0.695, p < 0.05, n = 25). The experimental model used here could be of great interest for the in vitro study of factors affecting lipid levels in plasma.

Age-related increased 14C-arachidonic acid uptake by platelets in normal subjects

Arachidonic acid uptake activity (pmol/10(8) platelets min) measured in platelets obtained from normal subjects was significantly higher in over-forty year old (3.53 +/- 0.38) than in under-forty year old subjects (2.33 +/- 0.12). No significant correlations were found between the arachidonic acid uptake activity and fasting plasma glucose, total cholesterol, HDL-cholesterol or triglyceride levels. The arachidonic acid uptake activity was significantly reduced by the presence of indomethacin in platelets obtained from both under and over-forty year old subjects, and by the presence of nordihydroguaiaretic acid in platelets obtained from over-forty year old subjects. In conclusion, these data show that arachidonate uptake activity by platelets increased with age. This increase was abolished when platelets were incubated in the presence of inhibitors of the arachidonic acid metabolism.

Effect of insulin and gliclazide on glucose utilization by a perfused intestine-pancreas preparation isolated from diabetic and non-diabetic rats

The effect of insulin (40 microU/ml) and gliclazide (200 micrograms/ml) on intestinal glucose metabolism was investigated by using an in vitro perfused intestine-pancreas preparation isolated from normal or streptozotocin-diabetic rats. Glucose, lactate and alanine were measured enzymatically in the portal effluent. The glucose retained by the perfused preparation was reduced (P < 0.05) in diabetic versus control rats. The portal lactate levels were not modified, but alanine portal levels were increased (P < 0.05) in diabetic versus control rats. In the diabetic rats, the level of glucose retained by the preparations was increased (P < 0.05) by the presence of insulin, and insulin plus gliclazide in the perfusate. In the presence of insulin and/or gliclazide, the portal lactate levels were not modified, but the alanine levels were reduced (P < 0.05) to normal values. In preparations from non-diabetic rats, the level of glucose retained was increased (P < 0.05) by gliclazide and insulin plus gliclazide, without modification of the portal lactate and alanine levels. In conclusion, the results show that both insulin and gliclazide increased glucose utilization by perfused intestine-pancreas preparations isolated from diabetic rats. The effect was enhanced when both substances were present simultaneously in the perfusion medium.

[Hyperkalemia and its electrocardiographic consequences in professional cyclists at the end of a bicycle race]

The plasma potassium levels were measured in 15 cyclists during the "Vuelta Ciclista al País Valenciano" (700 km, 6 days), both at the start and at the end of the last stage. Plasma potassium levels increased from 4.3 +/- 1.9 mmol/l (resting) to 7.3 +/- 3.2 mmol/l at the end of the stage. The increase in plasma potassium levels was related to changes in other plasma electrolyte levels and it led to electrocardiographic T wave and QRS abnormalities.

The effect of acarbose on the intestinal metabolism of glucose in vitro

The effect of acarbose on the intestinal metabolism of glucose was investigated using an in vitro perfused preparation of the isolated rat small intestine-pancreas. In preparations perfused without intraluminal sucrose administration, the total glucose recovered in the portal effluent and the portal values of lactate, pyruvate and alanine did not depend on whether or not acarbose [1.5 mg/kg body weight (b.w.)] was present in the intestinal lumen. The intestinal glucose and lactate contents were very low at the end of the experiment, and identical with or without acarbose. Insulin and glucagon concentrations remained constant during the whole perfusion period. After intraluminal administration of sucrose a clear increase in portal glucose concentration was observed, which was severely reduced by acarbose administration no changes in portal levels of lactate, pyruvate, alanine, insulin and glucagon were observed. The intestinal content of sucrose at the end of the study was significantly higher in the presence of acarbose (1.5 mg/kg b.w.), while the glucose concentration was low both with and without acarbose (0.20 +/- 0.08 vs 0.29 +/- 0.09 mmol/l respectively). These results suggest that acarbose does not influence the metabolic utilization of the glucose being translocated from the lumen.

Erythrocyte free radical scavenger enzymes in bicycle professional racers. Adaptation to training

This study was designed to investigate the influence of endurance training on the activities of the scavenger enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) measured in erythrocytes from sedentary subjects, amateur bicycle racers and in professional bicycle racers who were cycling in two real cyclist contests including the top-class race Vuelta a España (VCE). Under resting conditions the SOD activity was higher (p less than 0.01) in cyclists than in controls. The activities of CAT and GSH-Px were higher (p less than 0.05 and p less than 0.01, respectively) under resting conditions in professional cyclists versus measured both in sedentary subjects and amateur cyclists. The enzyme activities were not modified significantly in professional cyclists after a bout of exercise of 22 km in 5 hrs, but the SOD activity was increased (p less than 0.05) and CAT activity reduced (p less than 0.05) after 2800 km in 20 days (VCE). The present results shown that aerobic endurance training, when at a professional level, produces an increase in the erythrocyte activities of the main free radicals scavenger enzymes.

Subcutaneous cyclosporin prevents the development of complete Freund's adjuvant-streptozotocin-induced diabetes in the rat

The effect of subcutaneous cyclosporin administration (20 mg/kg) on the development of complete Freund's adjuvant (CFA)-streptozotocin-induced diabetes and on the induction of the so called cyclosporine diabetes like syndrome, were examined in Wistar rats. During and 5 weeks after the cyclosporin A treatment (21 days) the rats remained normoglycaemic. Three injections of 30 mg/kg streptozotocin given at weekly intervals, 24 hr after the administration of CFA, produced a persistent hyperglycaemia, an impairment of glucose tolerance and a drastic reduction in the pancreatic insulin content. The development of the diabetic state was prevented by cyclosporin treatment. The present results suggest that the cyclosporin diabetes like syndrome could not appear when cyclosporin was administered subcutaneously at the recommended doses for immunosuppression and that at such therapeutic doses, cyclosporin inhibits the development of CFA-Streptozotocin-induced diabetes in the Wistar rat.

Plasma lipid concentrations in professional cyclists after competitive cycle races

Plasma lipid concentrations were measured in professional cyclists at the beginning of the training season and both before the start and at the end of two cycle races of similar length (800 and 900 km in 6 days). Plasma concentrations of triglyceride, total and low density lipoprotein-cholesterol (LDL-C) and total cholesterol: high density lipoprotein-cholesterol (HDL-C) ratio were significantly lower and HDL-C concentrations significantly higher in cyclists compared to values in matched sedentary controls. At the end of the races, plasma concentrations of triglyceride and LDL-C were further reduced and HDL-C concentrations had increased compared to values at the start. At the end of the races, plasma concentrations of HDL-C were inversely correlated (r = -0.28, n = 45, P less than 0005) with triglyceride plasma concentrations. Body fat content, assessed as the sum of skinfold thicknesses was slightly reduced at the end of the race compared to the starting values. There was no significant correlation between skinfold thickness and plasma concentrations of HDL-C. Total plasma fatty acid concentrations were reduced and nonesterified fatty acids concentrations were increased at the end of the race compared to resting values. Consequently, the plasma concentrations of esterified fatty acids were significantly reduced after the race and there was a redistribution of the nonesterified fatty acids. The relative amounts of single fatty acids in the total fatty acid pool remained, however, remarkably constant. In conclusion, the results presented suggested that physical exercise, performed at the level of professional cyclists in a race, was an independent modifier of plasma lipid concentrations.

Gliclazide increases glucose utilization by rat intestine in vitro

The effect of gliclazide (a hypoglycemic sulphonylurea; 200 micrograms/ml) on the absorption and utilization of glucose and lactate production was investigated by using an in vitro perfused intestine-pancreas preparation isolated from fed rats, after intraluminal or arterial glucose administration. In the absence of intraluminal glucose administration, both glucose utilization and lactate production seem to be dependent on the arterial glucose concentration. The glucose utilization by the intestine was significantly increased in the presence of gliclazide (200 micrograms/ml) at three arterial concentrations of glucose (2.75, 5.5 and 11.0 mmol/l) without increasing the lactate production. The translocation of glucose from the lumen to the blood after intraluminal sugar administration was reduced when the glucose concentration was increased in the perfusate. In the presence of gliclazide (200 micrograms/ml) the translocation of glucose from the lumen to the blood was significantly reduced at the three arterial concentrations of glucose without affecting the intestinal absorption rate. In conclusion, gliclazide 200 micrograms/ml, increases the metabolic utilization of both arterially or intraluminally supplied glucose in isolated and perfused rat intestine-pancreas.

Increased arachidonic acid uptake by platelets from insulin-dependent diabetics and diabetic rats

14C-Arachidonic acid uptake was measured in platelets obtained from 15 insulin-dependent diabetic and 17 control subjects and in 12 streptozotocin-diabetic and 21 control rats. The 14C-arachidonic acid uptake, expressed as pmol/10(8) platelets/min, mean +/- SEM, was significantly higher in platelets from diabetic subjects (2.80 +/- 0.23) and diabetic rats (1.73 +/- 0.20) than in the control subjects (2.29 +/- 0.15) and the control rats (1.35 +/- 0.08). No significant correlations were found between arachidonic acid uptake and glucose, total cholesterol or triglyceride plasma levels in either rats or humans. Arachidonic acid uptake was inhibited by indometacin but not by nordihydroguaiaretic acid, in diabetic as well as in control subjects. The present results suggest that the increased arachidonic acid uptake by platelets from insulin-dependent diabetic patients and streptozotocin-diabetic rats depends on their increased platelet arachidonic acid utilization through the cyclooxygenase pathway.

In vitro study on the contribution of the rat intestine-pancreas to glucose homeostasis

Insulin release, glucose utilisation and lactate production were investigated using an in vitro perfused rat intestine-pancreas preparation after intraluminal or arterial glucose administration. In the absence of intraluminal glucose administration, both glucose utilisation and lactate production seem to be dependent on the arterial glucose concentration. Despite the different proportions in the portal values of glucose and lactate found at the various arterial glucose concentrations, the percentage of the total carbon atoms from infused glucose recovered in the portal vein remained constant. A significant (p less than 0.01) increase in insulin secretion was observed when the arterial glucose concentration was increased from 5.5 to 16.7 mmol/l. After intraluminal administration of glucose (4 g/kg body weight) both as a bolus or as an infusion, the lactate produced and the insulin released by the preparation were not significantly increased with respect to values measured in the absence of intraluminal glucose load. After intraluminal administration of glucose (1 g/kg body weight) as a bolus, the net translocation of glucose from the lumen to the vascular circuit was apparently reduced when the glucose concentration was increased in the perfusate from 2.75 to 11.0 mmol/l; this reduction could be dependent on an increase in the metabolism of absorbed glucose. In conclusion, the functional unit intestine-pancreas seems to play an important role in glucose homeostasis by elaborating the adequate mixture of glucose and lactate that must reach the liver under the various metabolic conditions.

Carboxylmethylation of insulin and glucagon in vitro

We studied the methyl acceptor capacity of insulin and glucagon in vitro. The levels of carboxylmethylation of pancreatic hormones (dpm x 10(3], when incubated with S-adenosyl-L-(3H-methyl)-methionine as methyl donor and purified protein carboxylmethylase, were: insulin (n = 6) 8.1 +/- 0.2 and 11.1 +/- 1.5 (mean +/- SEM) for 0.25 and 1.0 mg/ml, respectively; glucagon (n = 6) 17.0 +/- 3.2 and 40.2 +/- 2.5 (mean +/- SEM) for 0.5 and 1.0 mg/ml, respectively. On a molar basis, the methyl acceptor capacity was 1.0 dpm/pmol for insulin and 9.5 dpm/pmol for glucagon. Polyacrylamide gel electrophoresis of carboxylmethylated hormones showed a radioactivity (3H-methyl) peak that co-migrated with the corresponding 125I-hormone. Glucagon, but not insulin, seems to be a relatively good substrate for carboxylmethylation.

Influence of inorganic phosphate on glucose-induced insulin release in vitro

The effect of various extracellular phosphate concentrations on glucose induced insulin secretion has been investigated in two experimental systems the isolated perfused rat pancreas and the isolated rat pancreatic islets incubated in vitro. In both systems, total insulin secretion in response to 16.7 mmol/l glucose increased as extracellular phosphate concentration increased from 0 to 3.6 mmol/l. In perfusion experiments insulin secretion was significantly reduced at 4.8 mmol/l phosphate. In incubation experiments insulin secretion was inhibited only at 9.6 mmol/l phosphate concentration. When IBMX 1 mmol/l was used in incubation experiments glucose induced insulin secretion increased as extracellular phosphate increased from 0 to 3.6 mmol/l, but was also inhibited at 4.8 mmol/l.

Inorganic phosphate-insulin relationships in normal subjects and in patients with moderate glucose intolerance

The relationship between serum insulin and serum inorganic phosphate levels was investigated in normal subjects (NGT) and in patients with moderate impairment of glucose tolerance (IGT1 with subnormal and IGT2 with excessive insulin secretion) fasting and after oral glucose. Insulin and phosphate fasting levels were similar in all groups. In NGT subjects, a significant correlation between fasting insulin and inorganic phosphate levels are observed. In NGT and in IGT1 subjects, oral glucose administration was followed by a fall in serum phosphate level that was well correlated with the total insulin released. The phosphate fall was severely impaired in IGT2 patients, despite the increased insulin secretion. The plasma ionized calcium levels remain unchanged throughout the OGTT. The present results support the hypothesis that in IGT1 patients a reduced glucose-induced insulin release and in IGT2 patients, a peripheral resistance to insulin action could be the determinant of impaired glucose tolerance.

Effect of phosphate omission on the glucose-induced insulin release in vitro in fed and fasted rats

Isolated perfused rat pancreases from fed and 20-h fasted rats were used to investigate the effect of phosphate omission on the insulin response to 16.7 mmol/l glucose. The insulin response to continuous glucose stimulation was biphasic. Both phases were significantly reduced when pancreases were perfused in the absence of extracellular phosphate in fasted, but not in fed rats.

Effect of bicarbonate on the arginine-induced insulin and glucagon secretion in vitro

The isolated perfused rat pancreas was used to investigate the effect of extracellular bicarbonate concentration (25 and 40 mmol/l) on the arginine-induced insulin and glucagon release with or without 5.5 mmol/l glucose in the perfusate. In the absence of glucose, the insulin response to arginine was increased at 40 mmol/l bicarbonate, while no potentiation by glucose of the arginine-induced insulin release, at this bicarbonate concentration, was observed. At 40 mmol/l bicarbonate, glucose inhibition of basal glucagon release was abolished. In contrast, the glucagon response to arginine was not affected by the bicarbonate concentration in the perfusion medium. These results confirm that the bicarbonate concentration in the medium markedly influences the insulin release from the isolated perfused rat pancreas, while the glucagon response to arginine seems to be less sensitive to changes in extracellular bicarbonate concentration.

Effect of phosphate on the arginine-induced insulin release by the isolated perfused rat pancreas

The isolated perfused rat pancreas was used to investigate the effect of extracellular phosphate on the arginine-induced insulin release. In the absence of any metabolic substrate, the insulin response to arginine was monophasic. In the absence of phosphate in the medium, the insulin release as unaffected until the 15th minute of the stimulation period, but was significantly augmented from that time onward. In the presence of oleic acid in the perfusate, the insulin response to arginine was also monophasic but occurred earlier than in controls. In this conditin, phosphate omission resulted in an increase of the insulin response to arginine from the 3rd minute of the stimulatory period onward. In the presence of glucose 5.5 mM in the medium the insulin response to argnine was biphasic and was not affected by extracellular phosphate omission.

Effect of oleic acid on arginine-induced glucagon secretion by the isolated perfused rat pancreas

The isolated perfused rat pancreas was used to investigate the effect of oleic acid on glucagon secretion in response to 10 mmol/l arginine. In the absence of oleic acid and at 2.5 mmol/l calcium, arginine induced a biphasic glucagon secretion. At lower extracellular calcium concentration (1.0 mmol/l), the second phase of glucagon release was reduced, the first phase being unchanged. In the presence of 1,500 mumol/l oleic acid, the glucagon response to arginine was also biphasic, but second phase release was markedly inhibited, the first phase glucagon release being unchanged. Such an effect was not obtained when oleic acid concentration in the medium was 750 mumol/l. These results demonstrate that high concentrations of oleic acid inhibit glucagon secretion in response to arginine from the isolated perfused rat pancreas and support the concept that circulating free fatty acid levels are involved in the control of glucagon secretion.

Effect of phosphate omission on glucose-induced insulin release in vitro

In the isolated perfused rat pancreas, omission of extracellular phosphate (H2PO-4) significantly reduces the insulin secretion in response to 16.7 mM glucose.

Effect of oleic acid on insulin secretion by the isolated perfused rat pancreas

The isolated perfused rat pancreas was utilized to investigate the effect of oleic acid on insulin secretion. In the absence of glucose, a continuous infusion of oleic acid (1500 micromol/l) induced a biphasic insulin release. This effect was reduced at low extracellular calcium concentration. In the presence of oleic acid 1500 micromol/l, the insulin response to 10 mmol/l arginine occurred earlier, the total amount of insulin released in response to the amino acid being unchanged. Such an effect was not obtained when oleic acid in the medium was 750 micromol/l, but it was observed in the presence of oleic acid 1500 micromol/l when the concentration of albumin in the perfusate was increased from 2 g/100 ml to 4 g/100 ml. The insulin response to a continuous infusion of glucose (4.4 mmol/l and 16.7 mmol/l) was potentiated by the presence of oleic acid 1500 micromol/l in the perfusate. No modification of the biphasic pattern of insulin response to glucose 16.7 mmol/l was observed. These results demonstrate that high concentrations of oleic acid stimulate insulin release from the isolated perfused rat pancreas and modulate the insulin response to arginine or glucose.

Effect of somatostatin on the potentiating action of glucagon, cyclic adenosine monophosphate and theophylline on glucose-induced insulin release

The effect of glucagon on the inhibition of the insulin response to glucose induced by somatostatin was investigated in humans and in the isolated perfused rat pancreas. Both in vivo and in vitro somatostatin suppressed glucose-induced insulin release. This inhibitory effect of somatostatin was overcome by glucagon. Similar results have been observed in vitro by the infusion of theophylline or cyclic adenosine monophosphate.

Effect of various concentrations of calcium on arginine-induced insulin and glucagon release in vitro

The effect of extracellular calcium concentration on the insulin and glucagon release in response to arginine from the isolated perfused rat pancreas, has been studied. All the experiments were carried out in the absence of glucose in the perfusate. Arginine 10 mM elicited a biphasic glucagon release, and a monophasic insulin response. In the presence of calcium 2.5 mM an increase of total insulin and glucagon in response to arginine were obtained. The increase in glucagon release was only detectable during the second phase, while first phase was not modified by the concentration of calcium present in the perfusate. The results of this study show that extracellular calcium concentration influences positively insulin and glucagon responses to arginine in vitro.