Analysis of Polymorphism rs1042522 in TP53 Gene in the Mothers of Twins and of Singletons: A Population-Based Study in Rio Grande do Sul, Brazil.

Although the birth of twins has always attracted attention, there are no known genetic or environmental factors that can determine the birth of monozygotic (MZ) twins. And even for dizygotic (DZ) twins, genetic influences are not completely understood. A previous study from our group has shown that the C allele of polymorphism rs1042522 in the TP53 gene was more frequent in the mothers of twins than in the mothers of singletons in a small village in South Brazil. In order to clarify whether this was an isolated factor, we performed a population-based, observational case-control study. Samples were selected from a state-funded program of paternity investigation. Samples were considered cases when two of the children had the same date of birth, whereas controls were those samples in which at least two children were born in different dates. The first subsequent sample fulfilling control criteria was included after each case. From 2007 to 2013, 32,661 records were searched and 283 (0.9%) twins were found (119 MZ and 164 DZ). Genotypic and allele frequencies were not different between mothers of twins or mothers of singletons. However, mothers of MZ twins showed a higher frequency of GG genotype and lower frequency of the C allele when compared to mothers of DZ twins. Also, the proportion of MZ twins (42%) was higher than usually reported (30%). Finally, the proportion of twins found in this study seems to be more realistic, as this sample was allegedly not from users of assisted reproduction techniques.

ESI(+)-MS and GC-MS study of the hydrolysis of N-azobenzyl derivatives of chitosan.

New N-p-chloro-, N-p-bromo-, and N-p-nitrophenylazobenzylchitosan derivatives, as well as the corresponding azophenyl and azophenyl-p-sulfonic acids, were synthesized by coupling N-benzylvchitosan with aryl diazonium salts. The synthesized molecules were analyzed by UV-Vis, FT-IR, 1H-NMR and 15N-NMR spectroscopy. The capacity of copper chelation by these materials was studied by AAS. Chitosan and the derivatives were subjected to hydrolysis and the products were analyzed by ESI(+)-MS and GC-MS, confirming the formation of N-benzyl chitosan. Furthermore, the MS results indicate that a nucleophilic aromatic substitution (SnAr) reaction occurs under hydrolysis conditions, yielding chloroaniline from N-p-bromo-, and N-p-nitrophenylazo-benzylchitosan as well as bromoaniline from N-p-chloro-, and N-p-nitrophenylazobenzyl-chitosan.

There is no complete linkage between the polymorphisms N680S and T307A of the follicular stimulating hormone receptor gene in fertile women.

PURPOSE: We conducted a cross-sectional study to evaluate the linkage of FSHR T307A and N680S in a group of fertile women. METHODS: Peripheral blood was obtained from 51 fertile women. DNA extraction and isolation were performed. For the detection of the T307A polymorphism a set of primers (5_-TCTGAGCTTCATCCAATTTGCA-3_and 5_-GGGAAAGAGGGCA GCTGCAA-3) was used and then the product was further amplified by a second PCR-RFLP using another set of primers (5_-CAAATCTATTTTAAGGCAAGAAGTTGATTATATGCCTCAG-3_and 5_-GTAGATTCCAATGCAGA GATCA-3). For the N680S polymorphism the primers (5_-TTTGTGGTCATCTGTGGCTGC-3_ and 5_-CAAAGGCAAGGACTGAATT ATC ATT-3_) were used. Statistical analysis for the association between the polymorphisms was performed by the Spearman test. RESULTS: We calculated the association between the homozygosis at codon 307 and at codon 680 both for T/T-S/S and A/A-N/N. A significant association between the genotypic results at codon 680 with those at codon 307 was found (r = 0.6363, P = 0.001). However, a complete linkage between these two polymorphisms was rejected as there were 12 patients with discordant results from the expected A-N/T-S at codons 307 and 680, respectively. CONCLUSION: The current data demonstrated an association but failed to demonstrate a complete linkage between these two polymorphisms.

Mild cognitive impairment: cognitive screening or neuropsychological assessment?

OBJECTIVE: To describe the neuropsychological profile of mild cognitive impairment subtypes (amnestic, non-amnestic and multiple-domain) of a clinical sample. We further address the diagnostic properties of the Mini-Mental State Examination and the Cambridge Cognitive Examination for the identification of the different mild cognitive impairment subtypes in clinical practice. METHOD: Cross-sectional clinical and neuropsychological evaluation of 249 elderly patients attending a memory clinic at a university hospital in Sao Paulo, Brazil. RESULTS: The performance of patients with mild cognitive impairment was heterogeneous across the different subtests of the neuropsychological battery, with a trend towards an overall worse performance for amnestic (particularly multiple domain) mild cognitive impairment as compared to non-amnestic subtypes. Screening tests for dementia (Mini-Mental State Examination and Cambridge Cognitive Examination) adequately discriminated cases of mild Alzheimer's disease from controls, but they were not accurate to discriminate patients with mild cognitive impairment (all subtypes) from control subjects. CONCLUSIONS: The discrimination of mild cognitive impairment subtypes was possible only with the aid of a comprehensive neuropsychological assessment. It is necessary to develop new strategies for mild cognitive impairment screening in clinical practice.

Recognition of endophytic Trichoderma species by leaf-cutting ants and their potential in a Trojan-horse management strategy.

Interactions between leaf-cutting ants, their fungal symbiont (Leucoagaricus) and the endophytic fungi within the vegetation they carry into their colonies are still poorly understood. If endophytes antagonistic to Leucoagaricus were found in plant material being carried by these ants, then this might indicate a potential mechanism for plants to defend themselves from leaf-cutter attack. In addition, it could offer possibilities for the management of these important Neotropical pests. Here, we show that, for Atta sexdens rubropilosa, there was a significantly greater incidence of Trichoderma species in the vegetation removed from the nests-and deposited around the entrances-than in that being transported into the nests. In a no-choice test, Trichoderma-infested rice was taken into the nest, with deleterious effects on both the fungal gardens and ant survival. The endophytic ability of selected strains of Trichoderma was also confirmed, following their inoculation and subsequent reisolation from seedlings of eucalyptus. These results indicate that endophytic fungi which pose a threat to ant fungal gardens through their antagonistic traits, such as Trichoderma, have the potential to act as bodyguards of their plant hosts and thus might be employed in a Trojan-horse strategy to mitigate the negative impact of leaf-cutting ants in both agriculture and silviculture in the Neotropics. We posit that the ants would detect and evict such 'malign' endophytes-artificially inoculated into vulnerable crops-during the quality-control process within the nest, and, moreover, that the foraging ants may then be deterred from further harvesting of 'Trichoderma-enriched' plants.

Short cognitive performance test: diagnostic accuracy and education bias in older Brazilian adults.

The "Short Cognitive Performance Test" (Syndrom Kurztest, SKT) is a cognitive screening battery designed to detect memory and attention deficits. The aim of this study was to evaluate the diagnostic accuracy of the SKT as a screening tool for mild cognitive impairment (MCI) and dementia. A total of 46 patients with Alzheimer's disease (AD), 82 with MCI, and 56 healthy controls were included in the study. Patients and controls were allocated into two groups according to educational level (< or =8 years or >8 years). ROC analyses suggested that the SKT adequately discriminates AD from non-demented subjects (MCI and controls), irrespective of the education group. The test had good sensitivity to discriminate MCI from unimpaired controls in the sub-sample of individuals with more than 8 years of schooling. Our findings suggest that the SKT is a good screening test for cognitive impairment and dementia. However, test results must be interpreted with caution when administered to less-educated individuals.

Neuropsychological profile of Brazilian older adults with heterogeneous educational backgrounds.

Education significantly impacts cognitive performance of older adults even in the absence of dementia. Some cognitive tests seem less vulnerable to the influence of education and thus may be more suitable for cognitive assessment of older adults with heterogeneous backgrounds. The objective of this study was to investigate which tests in a cognitive battery were less influenced by educational levels in a sample of cognitively unimpaired older Brazilians. In addition, we evaluated the impact of very high educational levels on cognitive performance. The cognitive battery consisted of the Mini Mental State Examination (MMSE), Cambridge Cognitive Test (CAMCOG), Clock Drawing Test, Short Cognitive Performance Test (SKT), Rivermead Behavioural Memory Test (RBMT), Fuld Object Memory Evaluation (FOME), Verbal Fluency Test (VF) fruit category, Trail Making Test A and B, WAIS-R Vocabulary, and Block Design. Education did not exert a significant influence on the RBMT, FOME, and VF (p < .05). Subjects with very high educational levels had similar performance on the latter tests when compared with those with intermediate and low levels of education. In conclusion, the RBMT, FOME, and VF fruit category seem to be appropriate tools for the assessment of cognitive function in elderly Brazilians with varying degrees of educational attainment.

Mild cognitive impairment: cognitive screening or neuropsychological assessment? / Comprometimento cognitivo leve: rastreio cognitivo ou avaliação neuropsicológica?

OBJECTIVE: To describe the neuropsychological profile of mild cognitive impairment subtypes (amnestic, non-amnestic and multiple-domain) of a clinical sample. We further address the diagnostic properties of the Mini-Mental State Examination and the Cambridge Cognitive Examination for the identification of the different mild cognitive impairment subtypes in clinical practice. METHOD: Cross-sectional clinical and neuropsychological evaluation of 249 elderly patients attending a memory clinic at a university hospital in Sao Paulo, Brazil. RESULTS: The performance of patients with mild cognitive impairment was heterogeneous across the different subtests of the neuropsychological battery, with a trend towards an overall worse performance for amnestic (particularly multiple domain) mild cognitive impairment as compared to non-amnestic subtypes. Screening tests for dementia (Mini-Mental State Examination and Cambridge Cognitive Examination) adequately discriminated cases of mild Alzheimer's disease from controls, but they were not accurate to discriminate patients with mild cognitive impairment (all subtypes) from control subjects. CONCLUSIONS: The discrimination of mild cognitive impairment subtypes was possible only with the aid of a comprehensive neuropsychological assessment. It is necessary to develop new strategies for mild cognitive impairment screening in clinical practice.

OBJETIVO: Descrever o perfil neuropsicológico dos subtipos de comprometimento cognitivo leve, amnéstico, não-amnéstico e múltiplos domínios, de uma amostra clínica. Além disto, avaliou-se as propriedades diagnósticas do Mini-exame do Estado Mental e do Cambridge Cognitive Examination na identificação dos diferentes subtipos de comprometimento cognitivo leve na prática clínica. MÉTODO: Avaliação clínica e neuropsicológica transversal de 249 idosos em uma clínica de memória de um hospital universitário em São Paulo, Brasil. RESULTADOS: Testes de rastreio para demência (Mini-exame do Estado Mental e Cambridge Cognitive Examination) identificam corretamente casos de doença de Alzheimer leve, mas não apresentam boa acurácia para diferenciar os diversos subtipos de comprometimento cognitivo leve. A performance dos sujeitos portadores de comprometimento cognitivo leve foi heterogênea nos diferentes testes da bateria neuropsicológica, com uma tendência a uma pior performance global nos pacientes com o subtipo amnéstico (especialmente os com envolvimento de múltiplos domínios cognitivos) em relação ao comprometimento cognitivo leve não-amnéstico. CONCLUSÕES: A discriminação dos diferentes subtipos de comprometimento cognitivo leve foi possível somente a partir de uma avaliação neuropsicológica detalhada. Desta maneira, é necessário o desenvolvimento de novas estratégias de rastreio para esta condição na prática clínica.