Polymorphism of the Platelet Glycoprotein IIIa Gene in Patients with Coronary Stenosis

Based on genetic variability, structural differences in the glycoprotein IIb/IIIa platelet receptor for adhesive proteins result in individual differences in the thrombogenicity of platelets. Recent studies suggest a controversial association between a genetic polymorphism of the glycoprotein IIIa gene (PlA2) and the risk of coronary artery disease. In our study, the prevalence of the PlA2 allele in a group of patients undergoing percutaneous coronary revascularization was 37%, a value significantly higher than in controls [13%, odds ratio (OR) = 3.93, 95% CI, 1.84 to 8.53] suggesting a significant association between this polymorphism and documented coronary stenosis, which is strongest among <60 years old patients (OR = 12.30, 95% CI, 2.98 to 70.93). This polymorphism represents an inherited risk factor for severe cardiovascular disease due to coronary occlusion.

Television viewing time and risk of eating disorders in Spanish adolescents: AVENA and AFINOS studies

BACKGROUND

Effective preventive interventions for both eating disorders and obesity in adolescence should be focused on shared risk factors. We analyzed the association between television (TV) viewing time and the risk of eating disorders, as well as the potential role of obesity in this association.

METHODS

The sample consisted of a total of 3458 Spanish adolescents, aged 13-18.5 years, from the Food and Assessment of the Nutritional Status of Adolescents (AVENA) and Physical Activity as a Preventive Measure of the Development of Overweight, Obesity, Allergies, Infections, and Cardiovascular Risk Factors in Adolescents (AFINOS) studies. Adolescents' TV time was assessed by self-report. Body mass index was calculated and the adolescents were classified into non-overweight and overweight-obesity. The risk of eating disorders was evaluated using the SCOFF questionnaire.

RESULTS

Adolescents who watched TV >1 h/day had a higher risk for eating disorders, compared with those adolescents who watch TV <1 h/day. Also, overweight-obese adolescents had a higher risk for eating disorders than those who were non-overweight. Analyses across groups of TV viewing time and weight status showed similar trends, so that the higher the time spent in TV viewing, the higher the risk of eating disorders, regardless of weight status.

CONCLUSIONS

TV viewing time might be a focal point for prevention of both eating disorders and obesity in adolescence.

Design and evaluation of a treatment programme for Spanish adolescents with overweight and obesity. The EVASYON Study

Background

The prevalence of overweight and obesity (OW/OB) among adolescents worldwide has increased since the 60 s. Spain has reached one of the highest OW/OB prevalence rates among adolescents from European countries. The aim of this methodological paper is to describe the design and evaluation in the EVASYON study (Development, implementation and evaluation of the efficacy of a therapeutic programme for adolescents with OW/OB: integral education on nutrition and physical activity).

Methods/Design

The EVASYON was planned by a multidisciplinary team to treat OW/OB in Spanish adolescents. The EVASYON is a multi-centre study conducted in 5 hospitals in 5 Spanish cities (Granada, Madrid, Pamplona, Santander and Zaragoza) and two hundred and four OW/OB Spanish adolescents were recruited for this intervention. The treatment was implemented for approximately one-year follow-up. The adolescents were treated in groups of a maximum of 10 subjects; each group had 20 visits during the treatment period in two phases: intensive during the first 2 months (1^st to 9^th visits), and extensive during the last 11 months (10^th to 20^th visits). In order to assess the efficacy of the treatment, 8 dimensions were measured: diet; physical activity and fitness; eating behaviour; body composition; haematological profile; metabolic profile; minerals and vitamins; immuno-inflammatory markers. Moreover, genetic polymorphisms were also determined.

Discussion

The treatment programme developed in the EVASYON study was designed as a national pilot study to be implemented as an effective treatment for adolescents with OW/OB into the Spanish Health Care Service.

Novel drug nanocarriers combining hydrophilic cyclodextrins and chitosan

The aim of this study was to explore the possibility of obtaining nanoparticles (NPs) containing high amounts of cyclodextrin (CD) derivatives such as carboxymethyl-β-CD and sulphobutyl ether-β-CD. The rationale used was to combine the drug solubilizing and stabilizing properties of cyclodextrins (CDs) with the mucoadhesive properties of chitosan (CS) in a unique nanoparticulate drug delivery system. The size of the resulting NPs was affected by the nature of the CDs, ranging between 275 and 550 nm, whereas the zeta potential of the NPs was always positive and close to +35 mV. The positive zeta values, together with the results from NMR studies, suggest that CS is the major compound on the surface of the NPs, while CD molecules are strongly associated with the NP matrix. The empirical composition of the NPs was quantified by elemental analysis and the results indicated that the amount of CD associated with the NPs was strictly dependent on its electrostatic charge. Finally, in vitro stability studies indicated that the presence of CDs in the NP structure can prevent the aggregation of this nanometric carrier system in simulated intestinal fluid. Overall, this new type of NP represents an attractive drug delivery platform of particular interest for the oral administration of drugs with low bioavailability.

Cardiovascular fitness is negatively associated with homocysteine levels in female adolescents

OBJECTIVE

To examine the association between cardiovascular fitness and homocysteine levels in adolescents.

DESIGN

Cross-sectional study.

SETTING

Madrid, Murcia, Granada, Santander, and Zaragoza, Spain.

PARTICIPANTS

One hundred fifty-six Spanish adolescents (76 boys and 80 girls) aged (mean +/- SD) 14.8 +/- 1.4 years.

MAIN EXPOSURES

Cardiovascular fitness was measured by the 20-m shuttle run test. Pubertal stage, birth weight, smoking status, and socioeconomic status were determined, and the sum of 6 skinfold thickness measurements, and serum folic acid and vitamin B(12) levels were measured. Methylenetetrahydrofolate reductase (MTHFR; 677C>T genotype) polymorphism was done by DNA sequencing.

MAIN OUTCOME MEASURE

Fasting homocysteine levels.

RESULTS

Mean values of homocysteine were significantly higher in the MTHFR 677CT and TT genotype subgroups compared with the CC genotype subgroup in adolescent boys, whereas in adolescent girls, mean values of homocysteine were significantly higher in the MTHFR 677CT and TT genotype subgroup compared with the CC and CT genotype subgroups. Multiple regression analyses showed that cardiovascular fitness was significantly associated with homocysteine levels in female adolescents after controlling for potential confounders including the MTHFR 677C>T genotype (beta = -0.40; semipartial correlation = -0.35; P = .007). No associations were found between cardiovascular fitness and homocysteine levels in male adolescents (beta = 0.12; semipartial correlation = 0.08; P = .51).

CONCLUSION

The results suggest that cardiovascular fitness is negatively associated with homocysteine levels in female adolescents after controlling for potential cofounders including MTHFR 677C>T genotype.

Protection of the peptide glutathione by complex formation with α-cyclodextrin: NMR spectroscopic analysis and stability study

The main objective of this work was to investigate the complexation mechanism of the tripeptide glutathione with alpha-cyclodextrin (alpha-CyD). The final purpose was to explore the possibility of using this complexation approach for preserving the stability of this peptide in all biological environments relevant for oral drug delivery. The complexes between the peptide and alpha-CyD were formed in aqueous solution and the complexation mechanism was investigated using different (1)H NMR experimental approaches. The resulting complexes were also studied with respect to their ability to protect the peptide against proteolytic degradation by the exopeptidase, gamma-glutamyltranspeptidase. The NMR experiment, 1D-saturation transfer NOE difference (STD), evidenced the interaction between alpha-CyD and glutathione. The binding constants, calculated by a titration method, were in the range of 55-70 M(-1) at 25 degrees C and in the range 68-72 M(-1) at 37 degrees C. Moreover, from the 1D-pulse field gradient spin echo-transverse-rotating frame nuclear Overhauser (PFGSE-T ROESY) spectra it was concluded that alpha-CyD binds preferably to the l-glutamate (side chain) moiety of glutathione, leaving the glycine residue exposed to the external medium. This result was consistent with those of the in vitro stability study, which indicated that the degradation of glutathione was markedly reduced to the half in 2h upon inclusion in alpha-CyD. Overall, these results show the possibility of protecting specific peptide groups by their inclusion in CyDs as well as the utility of NMR experiments for the understanding of this stabilization strategy.

A comparative study of the potential of solid triglyceride nanostructures coated with chitosan or poly(ethylene glycol) as carriers for oral calcitonin delivery

We have previously reported the formation and characterization of poly(ethylene glycol) (PEG)-coated and chitosan (CS)-coated lipid nanoparticles. In the present work our goal was to study the interaction of these surface-modified lipid nanoparticles with Caco-2 cells and to evaluate the potential of these nanostructures as oral delivery systems for salmon calcitonin (sCT). The interaction of rhodamine-loaded nanoparticles with the Caco-2 cell monolayers was evaluated quantitatively and qualitatively by confocal laser scanning microscopy and fluorimetry, respectively. The ability of these nanoparticles to reversibly enhance the transport of hydrophilic macromolecules through the monolayers was investigated by measuring the transepithelial electric resistance and the permeability to Texas Red-dextran. Finally, in vivo studies of the response to sCT-loaded nanoparticles were performed in rats. The results showed that the association of rhodamine-loaded nanoparticles to the Caco-2 cell monolayer was independent of the surface coating of the nanoparticles (CS-coated versus PEG-coated nanoparticles). However, while PEG-coated nanoparticles did not affect the permeability of Caco-2 monolayers, CS-coated nanoparticles produced a dose-dependent reduction in the transepithelial electric resistance, simultaneously to an enhanced dextran transport. The results obtained following oral administration of sCT-loaded CS-coated nanoparticles to rats showed a significant and prolonged reduction in the serum calcium levels as compared to those obtained for control (sCT solution). In contrast, the hypocalcemic response of sCT-loaded PEG-coated nanoparticles was not significantly different of that provided by the control (sCT solution). Therefore, these results indicate that the surface composition of the particles is a key factor in the improvement of the efficiency of oral sCT formulations. Moreover, the encouraging results obtained for CS-coated nanoparticles underline their potential as carriers for peptide delivery.

Variables affecting BMI evolution at 2 and 5 years after vertical banded gastroplasty

BACKGROUND

Vertical banded gastroplasty (VBG) has been found to result in significant reduction in body mass index (BMI) during the first postoperative year. We investigated the impact of some intrinsic and extrinsic factors on long-term BMI evolution in morbidly obese patients who underwent VBG, with the aim of establishing a long-term weight-loss prognosis.

METHODS

67 consecutive morbidly obese patients who underwent VBG were followed for 2 years; of these, 34 were followed 3 more years, for a total follow-up of 5 years. BMI was monitored and correlated with demographic (preoperative BMI, obese relatives, age and gender) and lifestyle variables (physical activity, habitual dietary transgression and occupational status).

RESULTS

Global BMI fell from 47.5 at the time of the intervention to 32.1 when patients were examined 12 months after surgery. From the second year, an upward trend was observed, and at 5 years, mean BMI was above 35, considered in the high-risk range. Modifiable variables affecting lifestyle have shown significantly favorable effects on BMI evolution. Among intrinsic variables, BMI before surgery and obese parents also affect long-term evolution.

CONCLUSION

Different variables should be considered in order to establish a long-term weight-loss prognosis for each patient, thus making it possible to act more specifically on modifiable variables.

Polymorphism of the platelet glycoprotein IIIa gene in patients with coronary stenosis

Based on genetic variability, structural differences in the glycoprotein IIb/IIIa platelet receptor for adhesive proteins result in individual differences in the thrombogenicity of platelets. Recent studies suggest a controversial association between a genetic polymorphism of the glycoprotein IIIa gene (PlA2) and the risk of coronary artery disease. In our study, the prevalence of the PlA2 allele in a group of patients undergoing percutaneous coronary revascularization was 37%, a value significantly higher than in controls [13%, odds ratio (OR) = 3.93, 95% CI, 1.84 to 8.53] suggesting a significant association between this polymorphism and documented coronary stenosis, which is strongest among <60 years old patients (OR = 12.30, 95% CI, 2.98 to 70.93). This polymorphism represents an inherited risk factor for severe cardiovascular disease due to coronary occlusion.

Clinical features and outcome of 95 patients with hypersensitivity vasculitis

PURPOSE

To evaluate the clinical features and outcome of patients with isolated hypersensitivity vasculitis (HV).

PATIENTS AND METHODS

Retrospective study of patients with cutaneous vasculitis followed up at a University Hospital from 1975 to 1994. Patients with vasculitis secondary to collagen vascular diseases, neoplasia, or major infections were excluded. Patients were classified as HV according to the differential criteria proposed by Michel et al (J Rheumatol. 1992;19:721-728).

RESULTS

Ninety-five patients were classified as HV. The mean age was 42.7 +/- 21.7 years, with similar disease frequency in both sexes. In 43 patients, the precipitating event was drug therapy, either alone or as a treatment for a coexistent infection, usually an upper respiratory tract infection. The most frequent clinical manifestation was palpable purpura followed by joint symptoms. Systemic involvement was infrequent: 7 patients had nephropathy, manifested almost exclusively by microhematuria, and 5 patients had gastrointestinal symptoms. In 54 subjects the vasculitis did not require treatment; 26 patients were treated with NSAIDs, and 14 required corticosteroids (associated to immunosuppressive agents in 2 of them). After a mean follow-up of 15.5 +/- 28.9 months (median 6), only 2 patients had slight renal impairment, whereas the remaining had a complete recovery.

CONCLUSION

Hypersensitivity vasculitis is usually a benign syndrome, often secondary to drugs or infections, or both. Its main clinical manifestations are skin and joint symptoms. The systemic involvement is scarce and its prognosis is excellent.

Increased IgA-producing cells in the blood of patients with active Henoch-Schönlein purpura

Peripheral blood lymphocytes (PBL) producing IgA, IgM, and IgG, both spontaneously and after pokeweed mitogen stimulation in cell culture, were determined by a protein A hemolytic plaque assay in 20 children with active Henoch-Schönlein purpura (HSP), 42 with inactive disease, 22 normal controls of the same ages, and 18 children with upper respiratory tract infections (URTI). The geometric mean of circulating IgA-producing cells in active HSP (1,016 X divided by 1.55 cells/10(6) PBL) was increased when compared with the group with inactive disease (P less than 0.001), normal controls (P less than 0.001), and children with URTI (542 X divided by 2.03 cells/10(6) PBL, P less than 0.05). The number of circulating IgM-producing cells was slightly increased in active HSP (260 X divided by 2.65 cells/10(6) PBL) and URTI (256 X divided by 3.16 cells/10(6) PBL). Both values were higher than those found in the group with inactive disease (113 X divided by 2.26 cells/10(6) PBL, P less than 0.01). There were no significant differences among the 4 groups in the number of circulating IgG-producing cells. The number of cells producing each type of immunoglobulin after in vitro stimulation with pokeweed mitogen was similar in patients with active HSP, normal controls, and the group with inactive disease. These data demonstrate a selective increase in the number of circulating IgA-producing cells only during disease activity, and add further support to a possible pathogenic role of this immunoglobulin in HSP.

Serum complement components in Henoch-Schönlein purpura

Serum levels of C1q, C4, C3, C5, factor B, and properdin were measured in patients with Henoch-Schönlein purpura (HSP). In the cases of acute HSP, 9 of 23 (39%) had a low CH50, and 5 of 17 (30%) a low properdin; C1q, C4, and C3 levels were not depressed. In 10 cases with chronic nephritis following HSP, complement components were normal except for 2 with reduced C4 and one with low properdin. These findings confirm that complement activation occurs in HSP; the low serum levels of properdin in the acute group indicate that there is activation of the alternative pathway in these patients.

Cryoglobulinaemia in Henoch-Schönlein purpura

Sera from patients with Henoch-Schönlein purpura were examined for cryoglobulinaemia. Thirty patients had acute Henoch-Schönlein purpura, with or without renal diseas; 14 had chronic nephritis after a previous episode of purpura; and 17 were well, without urinary abnormalities, after recovering from Henoch-Schönlen purpura. Raised concentrations of cryoglobulins were present in 14 (47%) of those with acute purpura, nine (64%) of those with chronic nephritis, but none of those who had recovered completely from Henoch-Schönlein purpura. This suggests that acute Henoch-Schönlein purpura and the chronic nephritis that sometimes follows it have an immune-complex pathogenesis. IgA and properdin were found in several cryoglobulins, which suggested that complement had been activated via the alternative pathway, but isolated cryoglobulins capable of splitting C3 in vitro did so via the classical pathway.

Distal renal tubular acidosis in infancy: a bicarbonate wasting state

Three unrelated infants with apparently distal RTA were investigated. Growth retardation, polyuria, nephrocalcinosis, inappropriately high urinary pH, and marked dependence of bicarbonate excretion on urinary flow were characteristic of the distal or classic form of RTA, but the urinary loss of bicarbonate at normal serum values exceeded that usually found in children or adults with this disorder. Renal tubular function was studied during hypotonic saline diuresis in the three patients and in seven healthy control infants of similar age. Fractional delivery of sodium to the distal nephron was significantly higher in the patients than in control subjects. Sodium transport at the diluting segment was not impaired. The results support the assumption that the bicarbonate wasting was the consequence of an increased delivery of this substance to an already impaired distal nephron and thus further inhibited the distal mechanisms of net acid excretion.