A maximal effort trial in obese women carrying the beta2-adrenoceptor Gln27Glu polymorphism

The aim of this study was to observe the relationship of the beta2-adrenoceptor (ADRB2) gene polymorphism Gln27Glu in a group of obese female subjects submitted to an acute physical activity test. Six Glu27/Glu27 obese women were compared with six Gln27/Gln27 obese women (coupled by age, BMI, waist circumference, percentage of fat mass and absence of smoking). These groups were selected after having genotyped 91 obese subjects (BMI>30 kg/m2, age 20-60). Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used to genotype the obese population. The physical activity challenge consisted of a Maximal effort trial (VO2 max) following the Bruce protocol on a walking treadmill. The frequency for the Glu allele was 0.42, which is similar to other Caucasian populations. In basal conditions, subjects with the Glu27/Glu27 genotype showed a higher value of plasma insulin, while circulating glucose levels were similar in both groups. Also, diastolic arterial pressure was higher in the Glu27/Glu27 obese women. After the VO2 max trial, the Glu27 group had a significantly higher respiratory exchange ratio than the Gln27 group suggesting a lower post- exercise fat oxidation. These results provide evidence about a possible impact of the Gln27Glu polymorphism in the ADRB2 gene concerning a better response to exercise in obese Gln27 female subjects, in which basal insulinemia may play a role.

Factors influencing hematopoietic recovery after autologous blood stem cell transplantation in patients with acute myeloblastic leukemia and with non-myeloid malignancies

Factors influencing hematopoietic recovery (HR) after autologous blood stem cell transplantation (ABSCT) were analyzed in 73 patients with various non-myeloid malignancies (NMM), and in 58 patients with acute myeloblastic leukemia (AML). Peripheral blood stem cells were collected following mobilization with chemotherapy, granulocyte colony-stimulating factor (G-CSF), or chemotherapy plus G-CSF. The conditioning regimen used consisted of either chemotherapy alone (112 cases) or chemotherapy plus total body irradiation (19 cases). The median number of colony-forming units granulocyte-macrophage (CFU-GM) was similar in both groups of patients, with the median number of CD34(+) cells infused being higher in the AML group (5.4 vs 4 x 10(6)/kg; P = 0.03). Median time neutrophils >0.5 x 10(9)/l was 13 days in both groups, and median time to a platelet count >20 x 10(9)/l was longer in AML patients (14 vs 12 days; P = 0.01). In multivariate analysis, the only factors affecting neutrophil recovery in the NMM group were the CD34+ cell number (continuous model) and the CFU-GM dose (categorized model) infused, whereas for platelet recovery, previous chemotherapy also remained significant. In the AML group, the only factors significantly affecting the speed of neutrophil recovery were dose of CD34+ cells administered and the patient's age. As for platelet recovery, only the progenitor dose administered remained significant. In the NMM group, the most discriminating cut-off values for a rapid neutrophil and platelet recovery were 1.5 x 10(6) and 2.5 x 10(6) CD34+ cells/kg, respectively, and for AML patients these figures were 1.5 x 10(6) and 4 x 10(6) CD34+ cells/kg, respectively. Our results confirm the slower HR after ABSCT in AML, and highlight the importance of progenitor cell dose in accelerating HR after ABSCT.

Toxicity of a GM3 cancer vaccine in Macaca fascicularis monkey: a 12-month study

GM3 is a ganglioside that has been biochemically identified as dominating the cell surface of several human tumours, but is also found on human normal cells at much lower density. Since GM3 is widely distributed in essentially all types of animal cells, there is a conflict with the concepts of tumour-associated antigen, immunogen, and toxicity. We have designed a GM3-based cancer vaccine for the treatment of human breast and melanoma tumours. Prior to the Phase I clinical trial, we carried out a 12-month dose repeated toxicity study in five male Macaca fascicularis monkeys. Four male monkeys were treated with placebo in a similar way. During the study, no differences were observed between control and treated monkeys related to daily clinical observations (other than local damage) including rectal temperature, blood pressure, respiratory and cardiac rates, weight gain, biochemical and hematological parameters (with the exception of transitory pathological changes), and anti-DNA and anti-nuclear antibodies, although treated monkeys consistently developed both IgM- and IgG-specific anti-GM3 antibodies. Sixty per cent of treated monkeys developed moderate local reactions at the injection site, which disappeared without sequels. We concluded that this GM3 cancer vaccine overcame in monkeys the natural tolerance to GM3 ganglioside evidenced by a strong immune response, while the local reactions elicited-were transitory without apparent important systemic toxicity effects.

Inhibition of chaotic escape from a potential well by incommensurate escape-suppressing excitations

Theoretical results are presented concerning the reduction of chaotic escape from a potential well by means of a harmonic parametric excitation that satisfies an ultrasubharmonic resonance condition with the escape-inducing excitation. The possibility of incommensurate escape-suppressing excitations is demonstrated by studying rational approximations to the irrational escape-suppressing frequency. The analytical predictions for the suitable amplitudes and initial phases of the escape-suppressing excitation are tested against numerical simulations based on a high-resolution grid of initial conditions. These numerical results indicate that the reduction of escape is reliably achieved for small amplitudes and at, and only at, the predicted initial phases. For the case of irrational escape-suppressing frequencies, the effective escape-reducing initial phases are found to lie close to the accumulation points of the set of suitable initial phases that are associated with the complete series of convergents up to the convergent giving the chosen rational approximation.

No evidence for an association between genetic polymorphisms of beta(2)- and beta(3)-adrenergic receptor genes with body mass index in Aymara natives from Chile

OBJECTIVE

We assessed the association between Gln27Glu and Trp64Arg genetic polymorphisms of the beta(2) (ADRB2) and beta(3) (ADRB3) adrenergic receptor genes with body mass index and other cardiovascular risk factors.

METHODS

In a cross-sectional study, adult Aymara subjects (n = 152) living in the Andean regions of northern Chile were characterized with respect to their ADRB2 and ADRB3 genotypes, body mass index, plasma leptin and insulin levels, fasting glucose concentration, blood pressure, and plasma lipid profile.

RESULTS

The frequency of the Glu27 allele of the ADRB2 gene was estimated to be 0.04, and the allele frequency of the Arg64 variant of the ADRB3 gene was estimated as 0.13. No associations were found between the Trp64Arg polymorphism of the ADRB3 gene and body mass index or other cardiovascular risk factors. The small number of subjects with the allele encoding Glu27 in the ADRB2 gene seriously limited the analysis of the association between genotype and phenotype with the use of this polymorphism, although no clear associations were found.

CONCLUSION

We found insufficient evidence to support an association between polymorphisms Gln27Glu and Trp64Arg of the ADRB2 and ADRB3 genes, respectively, with body mass index and other cardiovascular risks in the rural Aymara population from Chile.

Interactions between an alpha2-adrenergic antagonist and a beta3-adrenergic agonist on the expression of UCP2 and UCP3 in rats

This experimental trial was devised to assess whether selective beta3-adrenergic receptor (AR) stimulation and simultaneous blockade of alpha2-AR would affect thermoregulation. With this purpose, the individual and combined administration of a beta-AR agonist, trecadrine, and an alpha2-AR antagonist, yohimbine, were evaluated. Yohimbine produced a marked decrease (p < 0.001) in body temperature one hour after administration (5 mg kg(-1), i.p.) and blocked the thermogenic effect of trecadrine (1 mg kg(-1), i.p.) when simultaneously administered. Uncoupling protein-2 expression in skeletal muscle was downregulated (p < 0.05) by trecadrine, while yohimbine had no effect. White adipose tissue UCP2 and muscle UCP3 were not modified by either trecadrine or yohimbine administration. Liver UCP2 mRNA expression was significantly decreased by yohimbine (p < 0.05). However, this downregulation does not seem to explain the reduction in temperature produced by yohimbine given the fact that trecadrine produced a similar downregulation of hepatic UCP2 (p < 0.05). The present work indicates that alpha2-AR antagonism blocks the thermogenic effects mediated by beta3-AR stimulation, contrary to our expectations, suggesting a possible interplay between both mechanisms. Moreover, these effects are not apparently explained by changes in UCP2 and UCP3.

Specific immune response to Parietaria judaica plant profilin: a low T cell proliferative response supports high IgE and skin prick test

BACKGROUND

allergic disease caused by Parietaria judaica (Pj) has been widely documented in Mediterranean area. Profilins have been identified as widely distributed allergenic proteins. The role of Pj profilin in specific immune response in Pj-sensitized patients is unknown.

METHODS

skin prick test and determination of specific and total IgE levels in serum were performed in all patients (n = 28) and non-allergic controls (n = 18). Peripheral blood mononuclear cells (PBMC) were isolated from both groups and stimulated with crude extract or highly purified Pj profilin. The production of type I and type II cytokines was determined by specific and polyclonal stimuli in patients and controls. T-cell lines specific to Pj profilin were established and cross-reactivity with another highly purified profilin from Phleum pratense (Phl p) was evaluated.

RESULTS

Pj profilin-sensitized patients showed a small but significantly increased in T-cell proliferative response to this profilin compared with non-atopic controls. The production of interleukin (IL)-4 and interferon (IFN)-&#947; in response to the specific stimulus was undetectable. However, the production of IL-4 in response to a polyclonal stimulus [phytohemagglutinin (PHA)] was significantly higher in atopic patients than in controls. The T-cell response did not correlate with the magnitude of response to skin prick tests with Pj profilin or with Pj-specific serum IgE levels. In addition, the production of IL-4 in response to a polyclonal stimulus (PHA) did not correlate with the individual skin prick tests to Pj profilin or with Pj-specific IgE levels in serum. The T-cell lines tested showed no cross-reactivity with Phl p profilin.

CONCLUSIONS

our results suggest that Pj profilin is partly responsible for the T-cell-mediated response in patients allergic to Pj. The high skin reactivity to Pj profilin is these patients was accompanied by a small increase in the T-cell response to this profilin. The response was highly specific since Pj profilin specific T-cell lines showed no cross-reactivity with a highly homologous profilin from Phl p. The lack of correlation between the proliferative T-cell response and polyclonal IL-4 production with allergen-specific serum IgE and skin reactivity probably indicates that some of the responding T-cells may be involved in immune reactions other than those supporting IgE production.

Changes in UCP2, PPARgamma2, and c/EBPalpha gene expression induced by a neuropeptide Y (NPY) related receptor antagonist in overweight rats

Neuropeptide Y (NPY), a peptide released by nervous cells, appears to contribute to adiposity regulation by increasing food intake and inhibiting lipolysis. New NPY receptor related antagonists such as S.A.0204 are being developed as potential anti-obesity drugs affecting adipocyte lipid metabolism and thermogenesis. In this sense, those animals fed on a high-energy yielding (cafeteria) diet decreased body fat weight as compared to overweight controls, when they were administered with S.A.0204, and increased body temperature, which statistically correlated with high UCP2 mRNA expression levels in white adipose tissue. In addition, the in vivo NPY-antagonist administration was able to prevent white adipose tissue growth in animals fed the cafeteria (high-fat) diet by impairing PPARy and CIEBPalpha mRNA expression in white fat cells. In summary, this novel NPY related-antagonist S.A.0204 may regulate body fat deposition by affecting both energy dissipation and white adipose tissue deposition, representing a potential new pharmacological strategy for obesity management.

Mediterranean diet and stroke: objectives and design of the SUN project. Seguimiento Universidad de Navarra

PURPOSE

The Mediterranean diet has been postulated as a protective factor against different diseases including stroke. Thus, an epidemiological study in a Mediterranean country, such as Spain, focused on diet may offer new insights of the potential benefits of this nutritional pattern to prevent the onset of cerebrovascular diseases.

METHODS

The SUN ("Seguimiento Universidad de Navarra") project is a prospective study among Spanish university alumni, aimed to identify the dietary determinants of stroke, coronary disease and other disorders. Two pilot studies have been developed. The first pilot study was focused on the understanding of the questionnaire. The second study used a random sample to assess the response proportion and the feasibility of using a mailing system for following-up the cohort. The first informative results are expected to be available after the first four years of following-up the cohort (2005). Here, we report the description of the baseline diet of the first participants in the cohort using data from 1,587 men and 2,260 women.

RESULTS

The outcome of our pilot studies ensure the feasibility of a mail-based cohort. In the baseline assessment, we found a high consumption of olive oil (18.5 g/person/day), red wine (28.8 g/person/day), legumes (102.5 g/person/day), vegetables (507.8 g/person/ day) and fruits (316.7 g/person/day), with a great between-subject variability. Also, the values for cereals (170.4g/person/day), dairy products (239.3 g/person/day) and meat and meat products consumption (186 g/person/ day) in this cohort were estimated. The coefficients of variation ranged in women from 56 (for vegetables) to 240% (for red wine) and in men from 62 to 180% (for these same two items), reflecting a wide heterogeneity in the diet of participants.

CONCLUSIONS

Although the participation was not high (22% according to the estimates of the pilot study), it was comparable to the proportion found in large previous cohorts such as the Nurses-II Health Study (24%). The sharp contrast in dietary habits between the US and Spain together with the high between-subjects variability we have found in our Spanish cohort provides an exceptional opportunity to assess the aspects of the Mediterranean diet, which may be protective against stroke and other neurological disorders.

Influence of dietary protein type and iron source on the absorption of amino acids and minerals

The apparent digestibility coefficient (ADC) of amino acids and the balance of minerals (calcium, phosphorus, magnesium and iron) has been determined in rats fed four diets differing in the protein type (casein or soy protein) and iron source (ferrous sulphate or lactate) in order to study the possible interactions of these nutrients. The availability of amino acids, especially essential amino acids, was greater in the diet made with animal protein (casein). The iron source also affected the absorption of most amino acids in all the diets assayed with ferrous sulphate being greater. The balance of iron, magnesium and phosphorus was higher in the diets containing animal protein. The retention of calcium and magnesium was significantly greater when ferrous sulphate was used as iron source. These results demonstrate the important interaction between amino acids and minerals and between the minerals themselves, which must be carefully studied when selecting different types of protein or mineral sources in human or animal nutrition.

Effects of leptin resistance on acute fuel metabolism after a high carbohydrate load in lean and overweight young men

OBJECTIVE

Six lean (BMI = 20.8 +/- 0.7) and seven overweight (BMI = 30.8 +/- 1.7) young men (18-27 years old) were studied to investigate the acute effect of a high-carbohydrate meal on leptin levels and its relation to energy expenditure as well as to protein, carbohydrate and fat oxidation.

METHODS

Study participants were given a high-carbohydrate meal (17% as protein, 80% as carbohydrates and 3% as lipids) covering 40% of their estimated daily energy requirements. Serum leptin. insulin. glucose, free fatty acids and triglycerides levels were measured before meal intake and during the frour postprandial hours. Furthermore, energy expenditure (EE), protein, carbohydrate and lipid oxidation were measured in fasted and fed conditions.

RESULTS

Fasting leptin was found to be positively correlated with circulating insulin concentrations (r = .748; p = 0.011) and body fat in kg (r = .827; p = 0.001). During the measured postprandial period no statistically significant changes were found in leptin levels as compared with pre-meal values in either lean or overweight men, nor differences in leptin changes between both groups. After load intake, carbohydrate oxidation was lower in overweight individuals (p < 0.05). while no significant differences were observed in protein oxidation. Cumulative lipid oxidation was found to be negatively associated with post-meal leptin values, being significantly lower in the overweight as compared with lean men (p < 0.05). This study demonstrates that the acute postprandial fuel substrate utilization is altered in overweight men with a lower carbohydrate oxidation and a strong inhibition of lipid oxidation, which could be attributed to some leptin resistance.

CONCLUSION

These data also suggest that short-term meal-related metabolic responses may explain the long-term body adiposity if they are sustained over long intervals.

Absence of platelet response after eradication of Helicobacter pylori infection in patients with chronic idiopathic thrombocytopenic purpura

Eradication of Helicobacter pylori infection has been associated with the correction of thrombocytopenia in patients with idiopathic thrombocytopenic purpura (ITP). We have analysed the response to eradication of H. pylori in a series of 56 adult patients with chronic ITP. Forty patients had H. pylori infection (71%) that was eradicated in 23 of 32 evaluable patients (72%). Platelet counts did not significantly vary according to H. pylori treatment outcome. Three of 56 patients (5%) achieved a partial response attributable to H. pylori eradication. Therefore, detection of H. pylori infection should not be routinely included in the initial work-up of ITP.

Standardized, unrelated donor cord blood transplantation in adults with hematologic malignancies

The potential role of unrelated donor cord blood transplantation (UD-CBT) in adults remains unclear. This study reports the results of UD-CBT in 22 adults with hematologic malignancies following conditioning with thiotepa, busulfan, cyclophosphamide, and antithymocyte globulin in 21, with thiotepa, fludarabine, and antithymocyte globulin in 1, and graft-versus-host disease (GVHD) prophylaxis with cyclosporine and prednisone. Median age was 29 years (range, 18-46 years), and median weight was 69.5 kg (range, 41-85 kg). HLA match was 6 of 6 in 1 case, 5 of 6 in 13 cases, and 4 of 6 in 8 cases. Median number of nucleated cells infused was 1.71 x 10(7)/kg (range, 1.01 x 10(7)/kg to 4.96 x 10(7)/kg). All 20 patients surviving more than 30 days had myeloid engraftment, and only 1, who received the lowest cell dose, developed secondary graft failure. Median time to reach an absolute neutrophil count of at least 0.5 x 10(9)/L was 22 days (range, 13-52 days). Median time to platelets numbered at least 20 x 10(9)/L was 69 days (range, 49-153 days). Seven patients (32%) developed acute GVHD above grade II, and 9 of 10 patients at risk developed chronic GVHD, which became extensive in 4 patients. Twelve patients remained alive and disease-free 3 to 45 months after transplantation. Disease-free survival (DFS) at 1 year was 53%. Age strongly influenced DFS (P =.01). For patients aged 30 years or younger, the DFS at 1 year was 73%. These preliminary results suggest that UD-CBT should be considered a reasonable alternative in young adults with hematologic malignancy and no appropriate bone marrow donor.

Treatment of humeral shaft nonunion by external fixation: a valuable option

We report the treatment of six patients with nonunion of the humerus, using a unilateral fixator and bone grafting. Union was obtained in all patients, with an average time to union of 4.5 months. Superficial pin tract infection was seen in five patients, but resolved uneventfully. One patient had transient radial nerve palsy. The results, according to the Stewart and Hundley criteria, were excellent in one patient, good in three, fair in one, and poor in one. The main cause of the fair and poor results was marked limitation of shoulder and elbow motion. This method, however, seems to be therapeutically effective.

Physiological and haematological consequences of a novel parasite on the red-rumped swallow Hirundo daurica

Parasite virulence has been hypothesised to increase with the degree of host sociality because highly social hosts have a greater probability of encountering horizontal transmission of parasites and experiencing infections with multiple strains of the same parasites than do solitary hosts. As compared with the defences of closely related social host species, we predicted that solitary hosts should have relatively weak defences against parasites, thus being relatively more affected when parasitised by a novel parasite. We tested this prediction by either experimentally infesting 12 nests of the solitarily nesting red-rumped swallow Hirundo daurica with 50 individuals of the generalist martin bug Oeciacus hirundinis or by fumigation of nine nests. Nestlings 13 days old from the parasite addition group experienced increased mortality, attained lower body mass and tended to have shorter tarsi compared to nestlings from fumigated nests. Surprisingly, nestlings from the parasite addition group had higher packed cell volume (cellular fraction of blood) and lower levels of heat shock proteins (HSP60) than nestlings from the fumigation group. A measure of immunocompetence was not significantly affected by treatment, but its magnitude was positively related to packed cell volume and negatively related to level of HSP60. Solitary hosts like the red-rumped swallow have weak immune responses and low levels of heat shock proteins when infested with ectoparasites while highly social hosts have strong immune responses and high levels of heat shock proteins when infested. These findings partially support the hypothesis that potential host species with weak defences are more susceptible to infection and the deleterious effects of evolving parasites than potential hosts with strong defences.

Role of Ca2+-independent phospholipase A2 on arachidonic acid release induced by reactive oxygen species

Previous studies have shown that reactive oxygen species (ROS) enhance arachidonic acid (AA) release and the subsequent AA metabolism in macrophages. The purpose of this study was determined the implication of phospholipases A2 (PLA2s) in these events. Our results show that oxidative stress induced by exogenous adding of hydrogen peroxide or superoxide anion in macrophage RAW 264.7 and mouse peritoneal macrophage cultures caused a marked enhancement of calcium-independent PLA2 (iPLA2) activity,whereas the increment of secreted PLA2 (sPLA2) and calcium-dependent cytosolic PLA2 (cPLA2) activities were slight. This increase of iPLA2 activity by ROS was rapid and dose-dependent. ROS also induced a significant [3H] arachidonic acid (AA) release. The iPLA2 selective inhibitor, bromoenol lactone, almost completely suppressed the mobilization of [3H]AA induced by ROS whereas antisense oligonucleotide against cPLA2 did not have any appreciable effect. Thus, our data show that iPLA2 activity is involved in the mechanism by which ROS increases the availability of free AA in macrophages RAW 264.7. Moreover, the protein kinase C (PKC) inhibitor, calphostin C, and calcium chelators had no effect on the [3H]AA release induced by ROS, suggesting this is a regulatory role of iPLA2.

[Increased bile lithogenicity after simultaneous total parenteral nutrition and octrotide. A model of calcium palmitate Gallstones]

Gallbladder stasis and gallstone formation are well-known complications of both fasting-associated total parenteral nutrition (TPN) and long-term treatment with octreotide. Additive noxious effects to hepatobiliary function may develop when both therapies are given together as treatment of enteric fistulae. The aim of this study was to assess the risk of gallstone formation during treatment with TPN and octreotide separately and in combination. We studied four groups of New Zealand rabbits (n = 32) during a 2-week intervention period: 14 chow-fed controls; 6 fasted and TPN-fed; 6 chow-fed and administered octreotide, and 6 fasted and treated with both TPN and octreotide. After treatment, the bile duct was cannulated and the gallbladder and liver tissue were obtained for histological analysis. Hepatic and gallbladder bile were retrieved for microscopic examination and measurement of biliary lipids, bilirubin, calcium, total protein, and cholesterol nucleation time. The chemical composition of gallstones was also analyzed. The results of the study suggest that simultaneous administration of these two therapies in rabbits has additive effects on gallbladder stasis and bile lithogenicity. The administration of both treatments can play an important role in the formation of calcium palmitate gallstones in these animals.