Organizações multilaterais, estado e políticas de educação infantil: history repeats

As políticas brasileiras de educação infantil (EI) nas últimas quatro décadas apresentam-se como resposta a várias tensões. Nos anos 70, o despertar dos novos movimentos sociais trouxe o tema para a agenda de suas reivindicações. Nos anos 80, pressões em diferentes sentidos provocaram, de um lado, a expansão da EI seguindo, de modo geral, um modelo "a baixo custo" e, de outro, a consciência social da EI como um direito das crianças pequenas à educação e um direito de assistência aos filhos de pais e mães trabalhadores (Constituição de 1988). O artigo descreve e analisa as tensões presentes, e suas conseqüências, em três momentos da história da EI brasileira contemporânea: a fase de expansão durante o governo militar; as inovações trazidas pela Constituição de 1988; o impacto das reformas educacionais contemporâneas sob a égide do "Consenso de Washington". A descrição e análise desses momentos serão efetuadas no contexto dos modelos propugnados pelas organizações multilaterais.

Molecular characteristics of Machado-Joseph disease mutation in 25 newly described Brazilian families

Machado-Joseph disease (MJD) is a form of autosomal dominant spinocerebellar ataxia first described in North-American patients originating from the Portuguese islands of the Azores. Clinically this disorder is characterized by late onset progressive ataxia with associated features, such as: ophthalmoplegia, pyramidal and extrapyramidal signs and distal muscular atrophies. The causative mutation is an expansion of a CAG repeat in the coding region of the MJD1 gene. We have identified 25 unrelated families segregating the MJD mutation during a large collaborative study of spinocerebellar ataxias in Brazil. In the present study a total of 62 family members were genotyped for the CAG repeat in the MJD1 gene, as well as 63 non-MJD individuals (126 normal chromosomes), used as normal controls. We observed a wide gap between the size range of the normal and expanded CAG repeats: the normal allele had from 12 to 33 CAGs (mean = 23 CAGs), whereas the expanded alleles ranged from 66 to 78 CAGs (mean = 71.5 CAGs). There were no differences in CAG tract length according to gender of affected individuals or transmitting parent. We observed a significant negative correlation between age at onset of the disease and length of the CAG tract in the expended allele (r = -0.6, P = 0.00006); however, the size of the expanded CAG repeat could explain only about 40% of the variability in age at onset (r2 = 0.4). There was instability of the expanded CAG tract during transmission from parent to offspring, both expansions and contractions were observed; however, there was an overall tendency for expansion, with a mean increase of +2.4 CAGs. The tendency for expansion appeared to the greater in paternal (mean increase of +3.5 CAGs) than in maternal transmissions (mean increase of +1.3 CAGs). Anticipation was observed in all transmissions in which ages at onset for parent and offspring were known; however, anticipation was not always associated with an increase in the expanded CAG repeat length. Our results indicate that the molecular diagnosis of MJD can be confirmed or excluded in all suspected individuals, since alleles of intermediary size were not observed.

Allelic frequencies of six polymorphic markers for risk of prostate cancer

The aim of the present study was to evaluate the distribution of polymorphisms for the androgen receptor (AR) (CAG, StuI, GGN), SRD5A2 (Ala49Thr, Val89Leu) and CYP17 (MspA1) genes that are considered to be relevant for risk of prostate cancer. We studied 200 individuals from two cities in the State of São Paulo, by PCR, PCR-RFLP and ASOH techniques. The allelic frequencies of the autosomal markers and the StuI polymorphism of the AR gene were very similar to those described in most North American and European populations. In relation to the CAG and GGN number of repeats, the study subjects had smaller repeat lengths (mean of 20.65 and 22.38, respectively) than those described in North American, European and Chinese populations. In the present study, 30.5% of the individuals had less than 22 CAG repeats and 45.5% had less than 23 GGN repeats. When both repeat lengths are considered jointly, this Brazilian population is remarkably different from the others. Further studies on prostate cancer patients need to be conducted to assess the significance of these markers in the Brazilian population.

Striatal and extrastriatal atrophy in Huntington's disease and its relationship with length of the CAG repeat

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that affects the striatum most severely. However, except for juvenile forms, relative preservation of the cerebellum has been reported. The objective of the present study was to perform MRI measurements of caudate, putamen, cerebral, and cerebellar volumes and correlate these findings with the length of the CAG repeat and clinical parameters. We evaluated 50 consecutive patients with HD using MRI volumetric measurements and compared them to normal controls. Age at onset of the disease ranged from 4 to 73 years (mean: 43.1 years). The length of the CAG repeat ranged from 40 to 69 (mean: 47.2 CAG). HD patients presented marked atrophy of the caudate and putamen, as well as reduced cerebellar and cerebral volumes. There was a significant correlation between age at onset of HD and length of the CAG repeat, as well as clinical disability and age at onset. The degree of basal ganglia atrophy correlated with the length of the CAG repeat. There was no correlation between cerebellar or cerebral volume and length of the CAG repeat. However, there was a tendency to a positive correlation between duration of disease and cerebellar atrophy. While there was a negative correlation of length of the CAG repeat with age at disease onset and with striatal degeneration, its influence on extrastriatal atrophy, including the cerebellum, was not clear. Extrastriatal atrophy occurs later in HD and may be related to disease duration.

Cryptic mosaicism involving a second chromosome X in patients with Turner syndrome

The high abortion rate of 45,X embryos indicates that patients with Turner syndrome and 45,X karyotype could be mosaics, in at least one phase of embryo development or cellular lineage, due to the need for the other sex chromosome presence for conceptus to be compatible with life. In cases of structural chromosomal aberrations or hidden mosaicism, conventional cytogenetic techniques can be ineffective and molecular investigation is indicated. Two hundred and fifty patients with Turner syndrome stigmata were studied and 36 who had female genitalia and had been cytogenetically diagnosed as having "pure" 45,X karyotype were selected after 100 metaphases were analyzed in order to exclude mosaicism and the presence of genomic Y-specific sequences (SRY, TSPY, and DAZ) was excluded by PCR. Genomic DNA was extracted from peripheral blood and screened by the human androgen receptor (HUMARA) assay. The HUMARA gene has a polymorphic CAG repeat and, in the presence of a second chromosome with a different HUMARA allele, a second band will be amplified by PCR. Additionally, the CAG repeats contain two methylation-sensitive HpaII enzyme restriction sites, which can be used to verify skewed inactivation. Twenty-five percent (9/36) of the cases showed a cryptic mosaicism involving a second X and approximately 14% (5/36), or 55% (5/9) of the patients with cryptic mosaicism, also presented skewed inactivation. The laboratory identification of the second X chromosome and its inactivation pattern are important for the clinical management (hormone replacement therapy, and inclusion in an oocyte donation program) and prognostic counseling of patients with Turner syndrome.

Evaluación del método de ELISA para detección de antígenos y complejos inmunes circulantes de Trypanosoma cruzi a través de un estudio de campo en una zona endémica de Argentina

En una zona endémica de la República Argentina se llevó a cabo un ensayo de campo de la prueba inmunoenzimática ELISA para la detección de antígenos (cAg) y complejos inmunes circulantes (CIC) en sueros de pacientes chagásicos crónicos. Del total de 215 muestras de sangre analizadas, 51 fueron positivas para ELISA-CIC y 45 lo fueron para ELISA-cAg. De los 74 (34,32% de la población) sujetos considerados infectados con dos reacciones serológicas positivas, 49 (66,21%) presentaron CIC en suero, en tanto que en 43 (58,11%) de ellos se encontró cAg por ELISA. Solo en 2 casos serológicamente no reactivos, se detectaron inespecíficamente CIC y cAg. Dentro del grupo considerado no infectado, se observó reactividad inespecífica de bajo título por una de las pruebas serológicas en 16 (11,35%) de 141 individuos. Estos sueros arrojaron resultados consistentemente negativos por ELISA-CIC y cAg demostrando la utilidad de estos métodos de diagnóstico antigénico en casos de serología conflictiva. La determinación de fracciones antigénicas circulantes por ELISA en individuos chagásicos crónicos permite evidenciar la infección por T. cruzi de manera más directa que midiendo la respuesta inmune humoral en el huésped, presentando además mayor sensibilidad que el diagnóstico parasitológico clásico

Random amplified polymorphic DNA (RAPD) analysis of Lutzomyia longipalpis laboratory populations

The phlebotomine sand fly Lutzomyia longipalpis has been incriminated as a vector of American visceral leishmaniasis, caused by Leishmania chagasi. However, some evidence has been accumulated suggesting that it may exist in nature not as a single but as a species complex. Our goal was to compare four laboratory reference populations of L. longipalpis from distinct geographic regions at the molecular level by RAPD-PCR. We screened genomic DNA for polymorphic sites by PCR amplification with decamer single primers of arbitrary nucleotide sequences. One primer distinguished one population (Marajó Island, Pará State, Brazil) from the other three (Lapinha Cave, Minas Gerais State, Brazil; Melgar, Tolima Department, Colombia and Liberia, Guanacaste Province, Costa Rica). The population-specific and the conserved RAPD-PCR amplified fragments were cloned and shown to differ only in number of internal repeats.

Friedreich's ataxia: clinical and molecular study of 25 Brazilian cases

INTRODUCTION: Friedreich's ataxia is a neurodegenerative disorder whose clinical diagnostic criteria for typical cases basically include: a) early age of onset (< 20 or 25 years), b) autosomal recessive inheritance, c) progressive ataxia of limbs and gait, and d) absence of lower limb tendon reflexes. METHODS: We studied the frequency and the size of expanded GAA and their influence on neurologic findings, age at onset, and disease progression in 25 Brazilian patients with clinical diagnosis of Friedreich's ataxia - 19 typical and 6 atypical - using a long-range PCR test. RESULTS: Abnormalities in cerebellar signs, in electrocardiography, and pes cavus occurred more frequently in typical cases; however, plantar response and speech were more frequently normal in this group when the both typical and atypical cases were compared. Homozygous GAA expansion repeats were detected in 17 cases (68%) - all typical cases. In 8 patients (32%) (6 atypical and 2 typical), no expansion was observed, ruling out the diagnosis of Friedreich's ataxia. In cases with GAA expansions, foot deformity, cardiac abnormalities, and some neurologic findings occurred more frequently; however, abnormalities in cranial nerves and in tomographic findings were detected less frequently than in patients without GAA expansions. DISCUSSION: Molecular analysis was imperative for the diagnosis of Friedreich's ataxia, not only for typical cases but also for atypical ones. There was no genotype-phenotype correlation. Diagnosis based only on clinical findings is limited; however, it aids in better screening for suspected cases that should be tested. Evaluation for vitamin E deficiency is recommended, especially in cases without GAA expansion.

Adsorção de cromo (VI) por carvão ativado granular de soluções diluídas utilizando um sistema batelada sob pH controlado

Na Amazônia o cromo é empregado principalmente na indústria de couro e de madeira, sendo responsável por vários problemas de saúde porque é tóxico para os seres vivos. A remoção de cromo de efluentes industriais é feita por meio de diversos processos como a adsorção. Este trabalho mostra os resultados da adsorção de Cr(VI) por carvão ativado granular comercial (CAG) como adsorvente de soluções diluídas empregando um sistema de adsorção batelada com controle de pH. Os grupos funcionais da superfície do CAG foram determinados pelo método de Boehm. Além disso, o efeito do pH na adsorção de Cr(VI), o equilíbrio e a cinética de adsorção foram estudados nas condições experimentais (pH = 6, MA = 6g, tempo de adsorção 90min.). Na superfície do CAG, os grupos carboxílicos foram determinados em maior concentração (MAS=0,43 mmol/gCAG), estes, presentes em concentrações elevadas aumentam a adsorção do metal, principalmente em valores de pH ácidos. A capacidade de adsorção é dependente do pH da solução, devido a sua influência nas propriedades de superfície do CAG e nas diferentes formas iônicas das soluções de Cr(VI). Os dados de equilíbrio da adsorção foram ajustados satisfatoriamente pela isoterma de Langmuir (R²=0,988), tipo favorável. A partir da cinética de adsorção a 5mg/L e 20mg/L, os resultados obtidos foram compatíveis com o valor limite preconizado na legislação nacional (Res. nº 357/05). Portanto, para o sistema experimental utilizando CAG foi eficiente na remoção de Cr(VI) a partir de correntes líquidas contendo baixas concentrações do metal.

Friedreich's Ataxia: Cardiac Evaluation of 25 Patients with Clinical Diagnosis and Literature Review

OBJECTIVE - Cardiac evaluation (clinical, electrocardiographic and echocardiographic) of 25 Brazilian patients with clinical diagnosis of Friedreich's ataxia (FA) related to the frequency and the size of GAA repeats (unstable expansion of trinucleotide repeats that results in the disease). METHODS - Clinical and cardiac study including electrocardiogram and echocardiogram of all patients and molecular analysis to detect the frequency and the size of GAA expansion, by polymerase chain reaction analysis. RESULTS - Homozygous GAA expansion was detected in 17 patients (68%) -- all typical cases. In 8 (32%) cases (6 atypical and 2 typical), no GAA expansion was observed, therefore it was not considered Friedreich's ataxia. All patients with GAA expansion (100%) had electrocardiographic abnormalities, and only 25% of the cases without GAA expansion had some abnormality on this exam. However, only 6% of all patients revealed some signals/symptoms suggestive of cardiac involvement. CONCLUSION - A molecular analysis is essential to confirm the diagnosis of Friedreich's ataxia; however, an adequate cardiac evaluation, including an electrocardiogram, was extremely useful to better screening the patients which should perform these molecular analysis.

Deletion, insertion and translocation of DNA sequences contribute to chromosome size polimorphism in Plasmodium berghei

Extensive chromosome size polymorphism in Plasmodium berghei in vivo mitotic multiplication. Size differences between homologous chromosomes mainly involve rearrangements in the subtelomeric regions while internal chromosomal regions are more conserved. Size differences are almost exclusively due to differences in the copy number of a 2.3 kb subtelomeric repeat unit. Not only deletion of 2.3 kb repeats occurs, but addition of new copies of this repeat sometimes results in the formation of enlarged chromosomes. Even chromosomes which originally lack 2.3 kb repeats, can acquire these during mitotic multiplication. In one karyotype mutant, 2.3 kb repeats were inserted within one of the original telomeres of chromosome 4, creating an internal stretch oftelomeric repeats. Chromosome translocation can contribute to chromosome size polymorphism as well We found a karyotype mutant in which chromosome 7 with a size of about 1.4 Mb is translocated to chromosome 13/14 with a size of about 3 Mb, resulting in a rearranged chromosome, which was shown to contain a junction between internal DNA sequences of chromosome 13/14 and subtelomeric 2.3 kb repeats of chromosome 7. In this mutant a new chromosome of 1.4 Mb is present which consists of part of chromosome 13/14.

The Pf332 gene codes for a megadalton protein of Plasmodium falciparum asexual blood stages

We characterized the Plasmodium falciparum antigen 332 (Ag332) which is specifically expressed during the asexual intraerythrocytic cycle of the parasite. The corresponding Pf332 gene has been located in the subtelomeric region of chromosome 11. Furthermore, it is present in all strais so far analyzed and shows marked restriction length fragment polymorphism. Partial sequence and restriction endonuclease digestion of cloned fragments revealed that the Pf332 gene is composed of highly degenerated repeats rich is glutamic acid. Mung been nuclease digestion and Northern blot analysis suggested that Pf332 gene codes for a protein of about 700 kDa. These data were further confirmed by Western blot and immunoprecipitation of parasites extracts with an antiserum raised against a recombinant clone expressing part of the Ag332. Confocal immunofluorescence showed that Ag332 is translocated from the parasite to the surface of infected red blood cells within vesicle-like structures. In addition, Ag332 was detected on the surface of monkey erythrocytes infected with Plasmodium falciparum.

Subtelomeric structure of Plasmodium falciparum chromosomes

Previous studies of subtelomeric regions in Plasmodium berghei led to the identification of subtelomeric repeats (2.3kb long) present in a variable number at many chromosomal ends. Both loss and increase in 2.3kb-repeat copy number are involved in chromosome-size polymorphisms. Subtelomeric losses leading to chromosome-size polymorphisms have been described by several authors in P.falciparum where the structure of subtelomeric regions is not known in detail. We therefore undertook their characterisation, by means of chromosome walking and jumping techniques, starting from the telomere-flanking sequence present in pPftel.1, the P.falciparum telomeric clone described by Vernick and McCutchan (1988). The results indicate that at least 20 (out of 28) chromosomal ends in P.falciparum 3D7 chromosomes share a subtelomeric region, about 40kb long, covering (but not limited to) the Rep20 region. Non repetitive, AT-rich portions flanking the Rep20 region on both sides are also conserved at most chromosomal ends.

Antibodies anti Bloodstream and Circumsporozoite Antigens (Plasmodium vivax and Plasmodium malariae/P. brasilianum) in Areas of Very Low Malaria Endemicity in Brazil

During 1992-1994, 33 malaria cases were reported in two regions in Brazil where few sporadic atypical cases occur, most of them in home owners, who are weekenders, while home caretakers live there permanently. Indirect Fluorescent Antibody Test (IFAT), with Plasmodium vivax, and Enzime Linked Immunosorbent Assay (ELISA) with repeat peptides of the circumsporozoite (CS) proteins of the 3 known P. vivax variants and P. malarie/P. brasilianum, were performed on 277 sera, obtained within a 5 to 10 km range of malaria cases. Very rarely did any of these donors recall typical malaria episodes. Blood smears of all but 5 were negative. One of the 5 malaria cases included in our serology was of a home owner, 1 of a permanent resident, 3 from Superintendência de Controle de Endemias employees who went there to capture mosquitoes. In Region 1 the prevalence of IFAT positive sera was 73% and 28% among caretakers, 18% and 9.6% among home owners. In Region 2 (3 localities) no distinction was possible between caretakers and home owners, IFAT positivity being 38%, 28% and 7%. The relative percentage of positive anti-CS repeats ELISA, differed for each of the peptides among localities. Dwellings are in the vicinity of woods, where monkeys are frequently seen. The origin of these malaria cases, geographical differences and high seropositivity is discussed

Protection against Toxoplasmosis in Mice Immunized with Different Antigens of Toxoplasma gondii Incorporated into Liposomes

Different toxoplasma antigens were entrapped within liposomes and evaluated, in this form, for their ability to protect Swiss mice against toxoplasma infection: soluble tachyzoite antigen (L/TAg), tissue cyst (L/CAg), tachyzoite plus tissue cyst (L/TCAg) or purified antigen of tachyzoite (L/pTAg). The protein used in L/pTAg was purified from tachyzoites using a stage-specific monoclonal antibody which reacted at a molecular weight of 32 kD in SDS PAGE and silver stain using reduced condition. To compare the immuno-adjuvant action of liposomes and of Freund's Complete Adjuvant (FCA), another group of mice was immunized with soluble tachyzoite antigen (STAg) emulsified in FCA (FCA/TAg). Control groups were inoculated with (STAg) alone, phosphate-buffered saline (PBS), FCA with PBS (FCA/PBS) and empty liposomes (L/PBS). Mice were inoculated subcutaneously with these antigens six, four and two weeks before a challenge with 80 tissue cysts of the P strain of Toxoplasma gondii orally. All mice immunized with or without adjuvant showed a humoral response, as measured by Elisa. However, no correlation was found between antibody titer and protection against the challenge. All mice immunized with L/pTAg or L/TCAg survived (100), whereas 80% and 90% of mice from groups which received respectively PBS or FCA/PBS and L/PBS died. All mice immunized with antigens entrapped within liposomes (L/TAg, L/CAg, L/TCAg and L/pTAg) showed low numbers of intracerebral cysts.