Infusion of Sydenham's chorea antibodies in striatum with up-regulated dopaminergic receptors: a pilot study to investigate the potential of SC antibodies to increase dopaminergic activity

Background

Sydenham's chorea (SC) is a neurological manifestation of rheumatic fever. Autoimmune mechanism of SC is supported by clinical improvement with immunomodulatory therapy; presence of circulating serum anti-basal ganglia antibodies; increase in Th2 group of cytokines in serum and CSF of patients. However, a role of the antibodies in the pathogenesis can only be established by their passive transfer. Chorea is a manifestation clearly related to increased dopaminergic (DA) activity. The purpose of this study was to investigate the potential of antibodies from patients with Sydenham's chorea to cause behavior alterations on rats with unilateral post-synaptic dopamine receptor up-regulation.

Methods

Rats previously submitted to 6-hydroxidopamine (6-OH-DA) unilateral lesion of substantia nigra pars compacta (SNc) and tested with apomorphine to ensure DA receptors up regulation, received intrastriatal infusion of antibodies from SC patients (n = 4) or healthy controls (n = 3) during 48 h. 24 h post infusion initiation (24PI) and 48 h post infusion initiation (48PI), we registered the occurrence of spontaneous contra lateral rotations (CLR).

Findings

SC group exhibited significantly higher number of CLR than control group at 24PI (p = 0.049) and 48PI (p = 0.048).

Conclusion

The limited sample of the present study restricts us to affirm that SC is really an immune-mediated condition. However the significant result of this pilot study points to preliminary evidence that SC antibodies may affect DA activity in rats with up-regulated striatal DA receptors.     

10-year trends in the health of Brazilian elderly: evidence from the National Household Sample Survey (PNAD 1998, 2003, 2008)

Data from a representative national household survey were used to examine 10-year trends (1998-2008) in health conditions of Brazilian elderly. A random sample of 105,254 individuals aged > 60 years participated. The mean age was 69 years and 56% were women. There was a gradual increase in the prevalence of good or excellent self-rated health (39.3%, 43.5% and 45.0%, in 1998, 2003 and 2008, respectively) and a decrease in self-reported arthritis, heart disease, and depression. The prevalence of self-reported hypertension (43.9%, 48.8%, and 53.3%, respectively) and diabetes (10.3%, 13.0% and 16.1% respectively) increased sharply. The prevalence of inability to perform activities of daily living (eating, bathing or using the toilet) remained stable (6.5%, 6.4% and 6.9%, respectively). The achievement of three or more physician visits over the previous 12 months increased by 21% from 1998 to 2008. Hospitalization decreased by 10% in the corresponding period. The above mentioned trends persisted after adjustments for age and sex. The results showed improvements in some health dimensions of the elderly, but not all. Changes in the use of health services occurred as expected with the expansion of primary healthcare activities in Brazil.     

Multiple imputation and complete case analysis in logistic regression models: a practical assessment of the impact of incomplete covariate data

Researchers in the health field often deal with the problem of incomplete databases. Complete Case Analysis (CCA), which restricts the analysis to subjects with complete data, reduces the sample size and may result in biased estimates. Based on statistical grounds, Multiple Imputation (MI) uses all collected data and is recommended as an alternative to CCA. Data from the study Saúde em Beagá, attended by 4,048 adults from two of nine health districts in the city of Belo Horizonte, Minas Gerais State, Brazil, in 2008-2009, were used to evaluate CCA and different MI approaches in the context of logistic models with incomplete covariate data. Peculiarities in some variables in this study allowed analyzing a situation in which the missing covariate data are recovered and thus the results before and after recovery are compared. Based on the analysis, even the more simplistic MI approach performed better than CCA, since it was closer to the post-recovery results.     

Skin pigmentation after NB‐UVB and three analogues of prostaglandin F2α in guinea pigs: a comparative study

Background Ultraviolet B (UVB) is a well‐known modality in increasing skin pigmentation through a variety of proposed mechanisms. Prostaglandin release is one of these mechanisms. Prostaglandin F_2α (PGF_2α) analogues, which are used to control ocular hypertension, were reported to induce periocular skin hyperpigmentation. Objectives This study aims to evaluate the local effect of three prostaglandin F_2α analogues, namely Latanoprost, Bimatoprost and Travoprost on skin pigmentation. Assessment of the role of combination with narrow band UVB (NB‐UVB) to each of these drugs is evaluated as well. Methods This study involved 18 female adult wild guinea pigs with patchy white and red/brown fur. The hair was shaved from four red/brown areas on the dorsal skin of each animal. In two areas of each animal, one of the above‐mentioned drugs was applied alone and in conjunction with NB‐UVB. In the other two areas, the vehicle was applied alone and in conjunction with NB‐UVB exposure. Skin biopsies from each area were done at the start of the study and 4 weeks after, and stained with haematoxylin and eosin (H&E) and Masson‐Fontana (MF) stains. Clinical and histopathological changes were evaluated. Results Increased pigmentation was found in all areas with PGF_2α analogues with and without NB‐UVB. However, the former group had more effect both clinically and histopathologically. Conclusion PGF_2α analogues are promising drugs in inducing skin pigmentation. This effect can be enhanced with NB‐UVB exposure.