Salt and the glycaemic response.

The possibility that salt increases plasma glucose and insulin responses to starchy foods was investigated. Six healthy adults took four morning test meals randomly: 50 g carbohydrate as cooked lentils or white bread, with or without 4.25 g of added salt (an amount within the range of salt found in a meal). When salt was added to the lentils the incremental area under the three hour plasma glucose curve was significantly greater than that for lentils alone (43.2 mmol.min/l v 11.1 mmol.min/l (778 mg.min/100 ml v 200 mg.min/100 ml]. When salt was added to bread the peak glucose concentration was significantly higher than that for unsalted bread (6.96 mmol/l v 6.35 mmol/l (125 mg/100 ml v 114 mg/100 ml], and this was followed by relative hypoglycaemia. Plasma insulin concentrations at 45 minutes were higher after a meal of salted lentils and salted bread than after the unsalted foods (p less than 0.05). The high insulin concentration after salted bread was sustained for one hour after the meal, thus the mean area under the three hour curve was 39% greater than that for unsalted bread (p less than 0.05). Salt may increase the postprandial plasma glucose and insulin responses to lentils and bread by accelerating the digestion of starch by stimulating amylase activity or accelerating small intestinal absorption of the liberated glucose, or both. The findings of this preliminary study, if confirmed by others, would support the recommendation that diabetics, as well as the general population, should reduce their intake of salt.     

5-n-alkylresorcinols of whole grain cereals and whole grain cereal products as biomarkers of healthy food

Epidemiological studies suggest that consumption of whole grain cereals and whole grain cereal products have many benefical health effects, including reducing risk of diabetes, obesity, coronary heart diseases, stroke and even some cancers. Precise knowledge protective compounds present in cereal grains can be achieved only when specific biomarkers (biological marker, indicator), that could provide estimation of grain cereals absorption and intake, are established and determined. 5-n-alkylresorcinols (main fraction of phenolic compounds in cereals), because of their specific occurrence only in bran fraction, obtained in refining of milling fractions process, could be a very good candidate to play the role of biomarker of whole grain intake. They are absorbed by animals and humans, present in human plasma and as metabolites in urine. Because composition of saturated homologues of 5-n-alkylresorcinols is different in rye and wheat grains, they could be used as an indicator of the intake of the specific type of cereals and whole grain cereal products.     

Influence of salt on glycaemic response to carbohydrate loading.

The effect of dietary salt on glycaemic responses to different test meals was investigated. Eight healthy male volunteers ate four test meals on consecutive mornings and in random order; the meals were 50 g carbohydrate taken as a 20% glucose solution or as boiled macaroni with and without supplementation with 6 g salt. In contrast with other reports, no significant differences in peak plasma glucose concentrations or areas under the plasma glucose curves could be established. These findings do not support a beneficial effect of salt restriction on glycaemic control in diabetes.     

Digestion of starch and glycaemic response to mixed meals in pigs.

The digestion in the proximal intestine of mixed meals (5,160 kJ) containing either native (NS) or pregelatinized (PS) maize starches (approximately 200 g), and the postprandial glycaemic responses they induced were compared in pigs. For both meals, approximately 25% of the ingested starch was assimilated above the duodenal cannula (positioned 75 cm beyond the pylorus). Larger amounts of starch were collected for NS than for PS during the first 30 min. The glycaemic responses, however, indicated a higher rate of glucose absorption for PS during the first 30 min, which could be explained by the higher susceptibility of PS to hydrolysis, as we observed in vivo. Indeed, malto-oligosaccharides (G1-G3) represented almost 80% of the total alpha-glucans collected at 150 min in the duodenum after the PS meal. At that time, after the NS meal, only 30% of the alpha-glucans were malto-oligosaccharides. Thus, even after a mixed meal, the starch digestion rate can alter the observed postprandial glycaemic response.     

Tissue culture evaluation of NaCl tolerance in Medicago species: Cellular versus whole plant response

Tissue culture responses to three levels of NaCl (0, 85mM and 170 mM) were evaluated in several Medicago species including: M. dzhawakhetica, M. marina, M. rhodopea, M. rupestris, M. sativa (alfalfa) and M. suffruticosa. The whole plant responses of the same genotypes were evaluated in half-strength Hoagland's solution containing 0, 51.5, and 103 mM NaCl. One or more genotypes of M. dzhawakhetica, M. rhodopea, M. rupestris, and M. sativa exhibited in vitro NaCl tolerance at 85 mM. In addition, one genotype each of M. dzhawakhetica, M. rhodopea, and M. sativa was tolerant of 170 mM NaCl. However, all of the genotypes that demonstrated NaCl tolerance in vitro were NaCl sensitive at the whole plant level. Conversely, M. marina the only species exhibiting whole plant NaCl tolerance, had the most NaCl sensitive genotypes at the in vitro level. Although an in vitro NaCl tolerance mechanism which confers whole plant NaCl tolerance was not observed, a potential NaCl tolerance germplasm source, M. marina, was identified.     

Insulin bolus given by sprinkler needle: effect on absorption and glycaemic response to a meal.

Two studies were conducted investigating the effect of injecting short acting insulin subcutaneously by means of a sprinkler needle; this needle has 14 small holes in the wall but is sealed at the tip. In the first study absorption of 8 U iodine-125 labelled Actrapid HM injected subcutaneously at two separate sites in the abdominal wall was measured in 10 patients. One injection was given with the sprinkler needle and the other with a conventional needle. The initial dose absorbed during the first 30 minutes was significantly higher with the sprinkler needle. In the second study 10 U Actrapid HM was given to 11 other patients (all negative for C peptide and with low insulin binding antibody titres) on two separate days immediately before a standardised breakfast either by the sprinkler needle or by a conventional needle (random order). Plasma free insulin increased more rapidly and to higher concentrations with the sprinkler needle and the glycaemic response was considerably diminished. The sprinkler needle improves both the insulin absorption rate and the glycaemic response to a meal and may reduce the 30 minutes or so before meals that diabetics must inject to minimise postprandial hyperglycaemia.     

Intake and digestion by lambs of dwarf elephant grass (Pennisetum purpureum Schum. cv. Mott) hay or hay supplemented with urea and different levels of cracked corn grain

This study was carried out to evaluate intake, digestibility, ruminal fermentation, nitrogen (N) retention and ruminal microbial protein synthesis in lambs fed dwarf elephant grass (Pennisetum purpureum Schum. cv. Mott) hay or hay supplemented with urea and 0, 5, 10 or 15 g/kg of live weight (LW) of cracked corn grain. Ten lambs (mean LW of 28 ± 0.9 kg), housed in metabolic cages, were used in a double 5 × 5 Latin Square experiment. Except fibre intake and digestibility, which was higher, the intake and digestibility of the others feed components, as well as ruminal microbial protein synthesis and N retention were lower in non-supplemented lambs. Corn supplementation increased total dry matter (DM) (P<0.05), organic matter (OM), non-structural carbohydrate (NSC) and energy intake (P<0.01) but decreased total neutral detergent fibre (aNDFom) (P<0.01) intake, as well as OM and aNDFom intake from the hay (P<0.01). Apparent DM, OM and energy digestibility, as well as OM true digestibility (OMTD) increased (P<0.01), and aNDFom digestibility decreased linearly (P<0.01) as corn supplementation increased. Total N intake was not influenced but, apparent and true N digestibility, as well as urinary N excretion decreased (P<0.01), and ruminal microbial N entering the small intestine increased linearly (P<0.01) as corn supplementation increased. However, the efficiency of ruminal microbial protein synthesis was similar for all treatments. Mean ruminal pH values and ammonia N concentrations decreased linearly (P<0.01) with level of corn supplementation. Ammonia N and amino acid, as well as peptide concentrations in ruminal fluid were quadratically related (P<0.01) with the time after feeding. Corn supplementation had a linear additive effect on total dry matter and digestible energy intake, as well as on N retention, but a linear negative effect on hay intake and on fibre digestibility. However, decreased forage digestibility by animals was probably neither related to lower ruminal pH, which values were always higher than 7.0, nor related to ruminal sugar concentrations, which were similar for all treatments.     

Pro- versus anti-inflammatory cytokines: myth or reality.

Inflammation is characterized by an interplay between pro- and anti-inflammatory cytokines. Cytokines are commonly classified in one or the other category: interleukin-1 (IL-1), tumor necrosis factor (TNF), gamma-interferon (IFN-gamma), IL-12, IL-18 and granulocyte-macrophage colony stimulating factor are well characterized as pro-inflammatory cytokines whereas IL4, IL-10, IL-13, IFN-alpha and transforming growth factor-beta are recognized as anti-inflammatory cytokines. In this review, we point out that this classification is far too simplistic and we provide numerous examples illustrating that a given cytokine may behave as a pro- as well as an anti-inflammatory cytokine. Indeed, the cytokine amount, the nature of the target cell, the nature of the activating signal, the nature of produced cytokines, the timing, the sequence of cytokine action and even the experimental model are parameters which greatly influence cytokine properties.     

Chemical composition of whole plant and grain and yield of nutrients in grain of five barley cultivars

Summary twenty seven field experiments were conducted to determine if there were differences between five barley cultivars in their ability to utilize soil nutrients. There were significant differences among cultivars in yield of grain and in concentration of all macro and micro nutrients examined in both the whole plant and grain.Gateway ranked the highest for the concentration of Na, Mn, and Cu in the whole plant and was among the cultivars with highest concentration of Ca, Fe, and Zn. Centennial had generally the lowest concentration of all the nutrients determined in the whole plant. For the concentrations of Na, Mg, and Cu in grain Gateway ranked highest, but ranked third for the concentrations of K, Ca, Fe, Mn, and Zn in grain. Galt had the highest K and Mg concentration and lowest Mn, Cu and Zn concentration in grain. Except for K concentration in grain, Centennial had the lowest concentrations of all other cationic nutrients in grain.Yield of grain rather than nutrient concentration was the most important criteria in determining the ranking of nutrient yields per hectare. Because of its high grain yield, Bonanza produced the largest yield of micronutrient cations and was second to Galt in production of macronutrient cations, although it was lowest in macronutrient cation concentration. Similarly, Bonanza and Galt had the lowest protein concentration, but produced the highest yield of protein per hectare.The implications for animal nutrition of different levels of nutrients between cultivars are discussed.     

Methacholine versus histamine: paradoxical response of spirometry and ventilation distribution.

We investigated the differential effect of histamine and methacholine on spirometry and ventilation distribution (where indexes S(cond) and S(acin) represent conductive and acinar ventilation heterogeneity; Verbanck S, Schuermans D, Van Muylem A, Noppen M, Paiva M, and Vincken W. J Appl Physiol 83: 1807-1816, 1997). Thirty normal subjects were challenged with cumulative doses of 6.52 micromol histamine and, on a separate day, with either 6.67 micromol methacholine (equal-dose group; n = 15) or 13.3 micromol methacholine (double-dose group; n = 15). Largest average forced expiratory volume in 1 s (FEV(1)) decreases or S(cond) increases obtained in either group were -9% and +286%, respectively; S(acin) remained unaffected at all times. In the equal-dose group, a smaller FEV(1) decline (P = 0.002) after methacholine was paralleled by a smaller S(cond) increase (P = 0.041) than with histamine. However, in the double-dose group, methacholine maintained a smaller FEV(1) decline (P = 0.009) while inducing a larger S(cond) increase (P = 0.006) than did histamine. The differential action of histamine and methacholine is confined to the conductive airways, where histamine likely causes the greatest overall airway narrowing and methacholine induces the largest parallel heterogeneity in airway narrowing, probably at the level of the large and small conductive airways, respectively. The observed ventilation heterogeneities predict a risk for dissociation between ventilation-perfusion mismatch and spirometry, particularly after methacholine challenge.     

Effects of citrated whole blood transfusion in response to hemorrhage.

BACKGROUND AND PURPOSE: Standard treatment for massive hemorrhage in dogs is infusion of whole blood or of packed red blood cells with fresh frozen plasma if whole blood is not available. Although most whole blood is collected using a citrate-based anticoagulant, knowledge of citrate's relevant non-anticoagulant effects is not widespread. Citrate's anticoagulant activity is achieved through chelation of divalent metal cations (e.g., magnesium, calcium), which may exacerbate cardiovascular and metabolic insults attributable to hemorrhage. METHODS: Blood pressures, gas tensions, metabolites, and electrolytes; myocardial metabolites, pressures, and contractility; cardiac output; and left cranial descending and circumflex coronary artery flows were measured in 21 anesthetized dogs after hemorrhage was induced by collection of blood into a citrated reservoir to mean arterial pressure of 45 mm Hg for approximately 60 min (until arterial lactate concentration was 7.0 mmol/L), followed by a 1-h transfusion and 2 h of maintenance. RESULTS: Arterial ionized calcium concentration, total peripheral resistance, and myocardial function decreased significantly during hemorrhage. All aforementioned responses but myocardial function continued to decrease during the initial 20 min of transfusion, then began to recover. Total peripheral resistance and end-systolic elastance were the only factors significantly related to calcium concentration. CONCLUSION: Transfusion with citrated whole blood may significantly alter calcium concentration, negatively affecting myocardial and vascular function.     

Pasteurization of salted whole egg inoculated with Arizona or Salmonella.

Recently, Arizona bacteria, close relatives of Salmonella, were recovered from salted whole egg that had been pasteurized by the presently recommended process of 63.3 degrees C (146 degrees F) for 3.5 min. Because of this and the fact that the heat resistance of Arizona in salted whole egg had not been determined, the present study was undertaken. Arizona or Salmonella, grown in Trypticase soy broth supplemented with 2% yeast extract in Fernbach flasks covered with aluminum foil over cotton and guaze at 35 degrees C with shaking at 176 rpm for about 96 h, were found to have the greatest degree of heat resistance. As expected, these cells, when inoculated into salted whole egg at 10(7) cells per ml, survived heating at 63.3 degrees C (146 degrees F) for 3.5 min in a two-phase slug flow heat exchanger. To consistently achieve a 7-log kill of typical Salmonella or Arizona, a treatment of 67 degrees C (152.6 degrees F) for 3.5 min was required. However, if a 7-log kill is mandatory, it remains to be determined whether this process affect the functional properties of this product.     

Pasteurization of salted whole egg inoculated with Arizona or Salmonella.

Recently, Arizona bacteria, close relatives of Salmonella, were recovered from salted whole egg that had been pasteurized by the presently recommended process of 63.3 degrees C (146 degrees F) for 3.5 min. Because of this and the fact that the heat resistance of Arizona in salted whole egg had not been determined, the present study was undertaken. Arizona or Salmonella, grown in Trypticase soy broth supplemented with 2% yeast extract in Fernbach flasks covered with aluminum foil over cotton and guaze at 35 degrees C with shaking at 176 rpm for about 96 h, were found to have the greatest degree of heat resistance. As expected, these cells, when inoculated into salted whole egg at 10(7) cells per ml, survived heating at 63.3 degrees C (146 degrees F) for 3.5 min in a two-phase slug flow heat exchanger. To consistently achieve a 7-log kill of typical Salmonella or Arizona, a treatment of 67 degrees C (152.6 degrees F) for 3.5 min was required. However, if a 7-log kill is mandatory, it remains to be determined whether this process affect the functional properties of this product.     

Ontogeny of a circadian rhythm in the glycaemic response of Gallus domesticus to glucagon

• 1.1. A circadian rhythm in the glucagon-mediated glycogenolytic response was absent in the newly-hatched chick but was present in the bird aged 1 week.
• 2.2. The peak glucose concentration was 38% higher in the afternoon in 1-week-old birds and 50% in 2-week-old birds.
• 3.3. The circadian rhythm was not present in 1-week-old birds subjected to constant illumination from hatching.
• 4.4. Starving the bird reduced the response to glucagon, irrespective of the time of day.

     

Phytochrome research in whole plant physiology. Wild-type seedlings versus mutants and transgenic plants

In this report I comment on a small selection of the many interesting papers presented at the European Symposium on Photomorphogenesis in Plants. My major concern arises from problems relating to classical phytochrome treatments versus mutants and transgenic plants as tools in photomorphogenic research on whole plant physiology. Plant responses to visible light are especially evident in etiolated seedlings, although they occur throughout the life cycle of the plant. These characteristics of plant photomorphogenesis in nature can be viewed as representing a continuous developmental series of graded responses to subsequent light exposures. Where the individual, photoautotrophic seedling is moving through this developmental gradient depends on its particular light environment, that is, on both the quality and the quantity of light to which the seedling is exposed. On the contrary, phytochrome treatment of mutants and transgenic seedlings having either deficiency or overexpression of photoreceptors will result in an aberrant kind of physiology.     

The importance and effect of dietary fiber in diabetes prevention with particular consideration of whole grain products.

The state of prediabetes is characterized by an increase in insulin resistance and a decrease in pancreatic beta cell function. The prestage of type 2 diabetes mellitus can be identified by an impaired glucose tolerance and/or by an impaired fasting blood sugar. Apart from weight loss and increase in physical activity, the development of type 2 diabetes mellitus can also be prevented by dietary changes. A low-fat diet with a dietary fiber intake of more than 30g/d was shown to represent an effective preventive approach. A high-fiber diet has many positive effects on the physical health status. In addition to positive effects in the gastrointestinal tract it has an obvious potential to support weight reduction and to improve disturbances of carbohydrate and fat metabolism. At the present state of knowledge, insoluble dietary fibers as found in whole grain cereal products are considered to be especially effective in the prevention of type 2 diabetes mellitus. A high intake of fruits and vegetables as well as pulses also exerts health-promoting properties. A high-fiber diet also plays an important role in the prevention of obesity and coronary heart diseases.