Effects of in vitro glycation on Fe3+ binding and Fe3+ isoforms of transferrin

BACKGROUND: In diabetes, protein function is altered by glycation, but the impact on the Fe3+ binding and antioxidant functions of transferrin (Tf) is largely unknown. The aim of the present study was to investigate the effects of glycation on the distribution of Fe3+ on the two Fe3+ -binding sites of Tf. METHODS: In vitro glycation of Tf was accomplished by preincubation with glucose for 14 days. Tf was loaded with Fe3+ compounds to achieve theoretical Tf Fe3+ saturations of 32%, 64%, and 96% (monitored by spectrophotometry). Fe3+ -Tf isoforms were separated by isoelectric focusing. RESULTS: Fe3+ binding was highest when Tf was incubated with Fe:nitrilotriacetic acid and reached a steady state overnight. Increasing the Fe3+ load led to a shift of isoform profile toward the diferric form (Fe2-Tf): in freshly prepared Tf, Fe2-Tf represented 6%, 30%, and 66% of all isoforms at 32%, 64%, and 96% theoretical Fe3+ saturation, respectively. Fe3+ was equally distributed to the monoferric Tf forms with Fe3+ bound to the amino (Fe1N-Tf) and carboxy termini (Fe1C-Tf). Glycation decreased binding of Fe3+ to Tf (monitored at 450 nm). At low theoretical Fe3+ saturation (32%), glycation increased the mean (SD) proportion of Fe2-Tf: 18 (3)% in the presence of 33.3 mmol/L glucose vs 12 (4)% with 0 mmol/L glucose (P = 0.01). In contrast, at 96% theoretical Fe3+ saturation, Fe2-Tf decreased linearly with increasing glycation (r = 0.97; P = 0.008). Preincubation, independent of glycation, favored the Fe1N-Tf isoform at 64% theoretical Fe3+ saturation [27 (0.7)% vs 23 (1.1)% of the Fe1C-Tf isoform; P = 0.009]. CONCLUSIONS: Glycation impairs Fe3+ binding and affects Fe3+ -Tf isoform distribution depending on concentration. The diagnostic implications of these results need further elucidation in clinical studies.     

The importance of gel properties for mucoadhesion measurements: a multivariate data analysis approach

In this study we used tensile strength measurements and a recently developed interpretation procedure to evaluate the mucoadhesive properties of a large set of gel preparations with diverse rheological properties. Multivariate data analysis in the form of principal component analysis (PCA) and partial least square projection to latent structures (PLS) was applied to extract useful information from the rather large quantities of data obtained. PCA showed that the selected series of gels was heterogeneous. Some groupings could be detected but none of the gels was identified as an outlier. By using PLS we investigated the relations between the rheological properties of a gel and the parameters defining the cohesiveness, as measured with the texture analyser used for the mucoadhesion measurements. The rheological properties proved to be important for the results of both the mucoadhesion and the cohesiveness measurements. Furthermore, by using PLS two different measurement configurations were evaluated and it was concluded that the combination of a relatively small volume of gel and two pieces of mucosa seems to be more appropriate than a large volume of gel in combination with one piece of mucosa.     

Parvovirus H-1 infection of human glioma cells leads to complete viral replication and efficient cell killing

The extremely poor prognosis of malignant gliomas requires the investigation of other than standard therapies, i.e., the application of oncolytic viruses. In our study, we evaluated the effects of the oncosuppressive parvovirus H-1 on different established glioblastoma cell lines of rat and human origin and on short-term/low-passage cultures of human glioblastoma cells. We observed an efficient and dose-dependent killing of all glioma cell cultures at low multiplicities of infectious particles (MOI) per cell. Southern blot analysis of viral DNA amplification, RT-PCR analysis of viral RNA expression and Western blot analysis of the expression of viral structural (VP-1/VP-2) and nonstructural (NS-1) proteins demonstrated the biosynthesis of these viral macromolecular components in all of the cultures. Moreover, all the glioma cells were proficient for the production of infectious H-1 virus particles. The amount of virus production differed between a several fold increase of the input virus titer in most of the short-term/low-passage cultures up to 1,000-fold in one short-term glioma and in the rat cells. Glioma cells lines and, more importantly, short-term/low-passage cultures of human glioblastomas were found to be highly susceptible target cells for H-1 virus mediated cytotoxicity. The formation of fully infectious progeny particles in infected glioma cells offers the chance for the induction of secondary rounds of infection resulting in an advanced cytotoxic effect. These advantageous characteristics of H-1 virus infection of glioma cells, combined with the known low toxicity of H-1 virus in nontransformed cells, make parvovirus H-1 a promising candidate for oncolytic glioma therapy.     

Hypothyroidism and cardiovascular disease: role of new risk factors and coagulation parameters

Hypothyroidism is a common condition and recent epidemiological studies demonstrated that up to 10 percent of subjects may display its subclinical form. Despite the well-known relationship between overt hypothyroidism and cardiovascular disease, few studies demonstrating such a link are available. However, the relationship between hypothyroidism and a variety of cardiovascular risk factors is now well established. Recent data on new cardiovascular risk factors that were shown to be associated with hypotyroidism are reviewed. Haemostatic and fibrinolytic parameters are disturbed differently according to the stage of hypothyroidism. C-reactive protein levels are higher in patients with overt and subclinical hypotyroidism compared to euthyroid patients. In contrast, elevation of homocysteine values was demonstrated only in overt hypothyroidism. Although no randomized controlled trial evaluated the potential benefits of levothyroxine substitution on the risk to suffer major coronary events in patients with subclinical hypothyroidism, there is growing evidence that this disorder is mainly characterized by a high risk of cardiovascular disease.     

Paroxetine treatment in children and adolescents with obsessive-compulsive disorder: a randomized, multicenter, double-blind, placebo-controlled trial

OBJECTIVE: To assess the efficacy and safety of paroxetine for the treatment of pediatric obsessive-compulsive disorder. METHOD: Children (7-11 years of age) and adolescents (12-17 years of age) meeting DSM-IV criteria for obsessive-compulsive disorder were randomized to paroxetine (10-50 mg/day) or placebo for 10 weeks. The primary efficacy measure was change from baseline in the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) total score at week 10 last observation carried forward end point. Safety was assessed primarily through adverse event monitoring. RESULTS: A total of 207 patients were randomized to treatment. Of these, 203 were included in the intention-to-treat population. Adjusted mean changes from baseline at week 10 observation carried forward end point in CY-BOCS total score for patients receiving paroxetine and placebo were -8.78 (SE=0.82) and -5.34 points (SE=0.77), respectively. The adjusted mean difference, -3.45 in favor of paroxetine, was statistically significant (95% confidence interval=-5.60 to -1.29, p=.002). Adverse events were generally mild to moderate in intensity. A total of 10.2% (10/98) of patients in the paroxetine group and 2.9% (3 of 105) in the placebo group discontinued treatment because of adverse events. CONCLUSIONS: Paroxetine is an effective and generally well-tolerated treatment for obsessive-compulsive disorder in children and adolescents.     

Comparison of different ibuprofen-amino acid compounds with respect to emulsifying and cytotoxic properties

Sodium ibuprofen (Ibu-Na) and different ibuprofen-amino acid compounds, lysinate (Ibu-Lys), arginate (Ibu-Arg) and histidinate (Ibu-His), were evaluated for emulsifying, haemolytic and cytotoxic properties. The highest reduction of surface tension was obtained with Ibu-Lys which shows good emulsifying qualities. At the same time, Ibu-Lys reveals the highest haemolytic activity and affects porcine cornea integrity. However, incorporation of Ibu-Lys into an emulsion system significantly decreases haemolysis. On the contrary Ibu-Arg, which shows a lower surface tension reduction, allows, unlike Ibu-Na and Ibu-His, for comparably stable emulsions with comparable erythrocyte damage.     

Estimating Non-Response Bias in Family Studies: Application to Mental Health and Lifestyle

Non-response to mailed surveys reduces the effective sample size and may introduce bias. Non-response has been studied by (1) comparison to available data in population based registers, (2) directly contacting non-respondents by telephone or single-item reply cards, and (3) longitudinal repetition of the survey. The goal of this paper was to propose an additional method to study non-response bias: when the variable of interest has a familial component, data from respondents can be used as proxy for the data from their non-responding family members. This approach was used with data on smoking, alcohol consumption, physical activity, coffee- and tea-use, education, body mass index, religion, burnout, life events, personality and mental health in large number of siblings and DZ twins registered with the Netherlands Twin Register. In addition, for smoking behavior, we also used the second strategy by sending a reply card. Results show that scores of members from less cooperative families or incomplete twin pairs tended to be more unfavorable than the scores from highly cooperative families or complete twin pairs. For example, family members from less cooperative families cycled less often and scored higher on anxious depression and neuroticism. For smoking, both the results of the reply card and the results of the additional method suggested a higher percentage smokers among the non-respondents but this was only significant with reply card method. In general, differences between highly/less cooperative families and complete/incomplete DZ twins were small. Results suggest that, even for studies with moderate response rates, data collected on health, personality and lifestyle are relatively unbiased.     

Endometriosis and subfertility: is the relationship resolved?

There are many arguments to support the hypothesis that there is a causal relationship between the presence of endometriosis and subfertility. These arguments are reviewed in this article and include: (1) an increased prevalence of endometriosis in subfertile women compared with women of proven fertility; (2) a reduced monthly fecundity rate (MFR) in baboons with mild to severe (spontaneous or induced) endometriosis compared with those with minimal endometriosis or a normal pelvis; (3) a trend toward a reduced MFR in infertile women with minimal to mild endometriosis compared with women with unexplained infertility; (4) a dose-effect relationship: a negative correlation between the r-AFS stage of endometriosis and the monthly fecundity rate and crude pregnancy rate; (5) a reduced monthly fecundity rate and cumulative pregnancy rate after donor sperm insemination in women with minimal-mild endometriosis compared with those with a normal pelvis; (6) a reduced MFR after husband sperm insemination in women with minimal to mild endometriosis compared with those with a normal pelvis; (7) a reduced implantation rate per embryo after IVF in women with moderate to severe endometriosis compared with women with a normal pelvis; and (8) an increased monthly fecundity rate and cumulative pregnancy rate after surgical removal of minimal to mild endometriosis.     

Hypomandibular faciocranial dysostosis in consanguineous parents revealed by ultrasound prenatal diagnosis

We report here the fourth case of hypomandibular faciocranial dysostosis (HFD). The diagnosis was made at birth on the association of severe retrognathia, microstomia, severe hypoglossia with glossoptosis, persistent buccopharyngeal membrane, median cleft palate, bifid uvula, down-slanting palpebral fissures, short nose with anteverted nares, laryngeal hypoplasia, and low-set ears. A severe microstomia and micrognathia were detected by ultrasound at 31 weeks of gestation. Interestingly, even though the present case exhibits many facial dysmorphic features characteristic of HFD, craniosynostosis was absent. This report suggests that craniosynostosis is not mandatory for the diagnosis of this condition. Furthermore, we present a new argument for an autosomal recessive mode of inheritance for HFD.