Experimental Fock-State Superradiance.

Superradiance in an ensemble of atoms leads to the collective enhancement of radiation in a particular mode shared by the atoms in their spontaneous decay from an excited state. The quantum aspects of this phenomenon are highlighted when such collective enhancement is observed in the emission of a single quantum of light. Here we report a further step in exploring experimentally the nonclassical features of superradiance by implementing the process not only with single excitations, but also in a two-excitation state. Particularly, we measure and theoretically model the wave packets corresponding to superradiance in both the single-photon and two-photon regimes. Such progress opens the way to the study and future control of the interaction of nonclassical light modes with collective quantum memories at higher photon numbers.

Psychogenetics of Turner syndrome: an investigation of 28 subjects and respective controls using the Bender test and Piagetian scales.

Piagetian scales and the Bender visual motor gestalt test (BT) were applied to 28 subjects with universal 45,X Turner syndrome (TS), and their respective controls, in order to investigate their cognitive performance. Dermatoglyphics were also analyzed to obtain clues concerning embryological changes that may have appeared during development of the nervous system and could be associated with cognitive performance of TS patients. Dermatoglyphic pattern distribution was similar to that reported in previous studies of TS individuals: ulnar loops in the digital patterns and finger ridge, a-b, and A'-d counts were more frequent, while arch and whorl patterns were less frequent compared to controls. However, we did not find higher frequencies of hypothenar pattern, maximum atd angle, and ulnarity index in our TS subjects, unlike other investigations. Furthermore, we found significant differences between TS and control T line index values. The BT scores were also lower in probands, as has been previously reported, revealing a neurocognitive deficit of visual motor perception in TS individuals, which could be due to an absence of, or deficiency in, cerebral hemispheric lateralization. However, TS subjects seemed to improve their performance on BT with age. Cognitive performance of the TS subjects was not significantly different from that of controls, confirming a previous study in which TS performance was found to be similar to that of the normal Brazilian population. There were significant correlations between BT scores and Piagetian scale levels with dermatoglyphic parameters. This association could be explained by changes in the common ectodermal origin of the epidermis and the central nervous system. TS subjects seem to succeed in compensating their spatial impairments in adapting their cognitive and social contacts. We concluded that genetic counseling should consider cognitive and psychosocial difficulties presented by TS subjects, providing appropriate treatment and orientation for them and their families.

Holoacardius acephalus-myelecephalus.

Holoacardius acephalus is a rare anomaly occurring in twin pregnancy. This case was an amorphic monstrous mass with only lower limb buds showing five digits and no definite human form unlike those reported in the Indian literature which either showed the presence of other body parts like thorax, abdomen and head and neck structures or were totally undifferentiated. The other twin had intra uterine growth retardation. This case came to the hospital in labour. As this condition can be recognised in the antenatal period, diagnosis of this anomaly is important for better perinatal outcome.

Haemangiopericytoma--an unusual tumour--a report of 5 cases.

Haemangiopericytoma (HPC) has remained a controversial entity ever since its first description. The main histological criterion to diagnose this entity is the characteristic vascular pattern highlighted by the reticulin stain. Since this pattern can be present in several other connective tissue tumours, it is basically a diagnosis of exclusion. Electron microscopy has however been helpful in some cases.

Frequency of oral mucosa micronuclei in gas station operators after introducing methanol.

Methanol has been proposed in different countries as an alternative automotive fuel to be used as an additive to, or replacement for, gasoline or ethanol. Utilization of methanol is increasing exposure to low levels of methanol vapors in the environment and more specifically in occupational settings such as gas stations. Pump operators are exposed to relatively high levels of fuel vapors, the consequences of which have not been fully examined. In this study, the micronucleus assay in squamous oral cells was performed on pump operators of 28 gas stations in three different periods in the city of São Paulo, Brazil. The frequency of micronuclei (MN) was evaluated before and 1 year after a mixed fuel called MEG, which contains 33% methanol, 60% ethanol and 7% gasoline, was introduced. The third evaluation, 3 years later, represents a period where the number of cars using alcohol fuel had decreased drastically and the pump operator exposure to MEG became very low. The frequency of MN observed in 76 employees in 1992 (mean = 3.62 +/- 0.39) was significantly increased (P < 0.001) as compared with 76 operators exposed in 1989 (mean = 1.41 +/- 0.26) and 129 exposed in 1995 (mean = 1.20 +/- 0.15). These differences were also significant when compared with control groups not exposed professionally to motor fuel. These findings could indicate a mutagenic hazard of the MEG occurring in those with occupational exposure.

Chromosomal aberrations in peripheral lymphocytes of abstinent alcoholics.

The frequency of structural and/or numerical chromosomal aberrations in human metaphasic cells of lymphocyte cultures from abstinent alcoholics who were abstinent for 1 month up to 32 years was compared with those from controls not selected for alcohol consumption. Cytogenetic analyses revealed a significant increase of the frequencies of cells with structural aberrations in the abstinent alcoholics (7.1%), compared with controls (2.4%). The frequency of numerical aberrations showed a significant regression on ages in abstinent alcoholics and controls. These results suggest specific action of chronic alcohol consumption impairing biological repair with aging. The increased frequency of chromosome-type aberrations associated with alcohol consumption, even after long withdrawal, could be due to an action of ethanol or its metabolites on primordial leukopoietic cells.

A tragédia da talidomida e o advento da teratologia experimental / The thalidomide tragedy and the birth of experimental teratology

Avaliou-se o desenvolvimento histórico da "Tragédia da Talidomida", desde a utilizaçao inicial da droga na Alemanha Ocidental, seguindo sua comercializaçao em vários países da Europa, bem como do impedimento de sua fabricaçao nos E.U.A. Inicialmente prescrita como "autêntica panacéia" em várias áreas da prática médica, a talidomida foi amplamente consumida por gestantes, causando a maior epidemia iatrogênica da História da Medicina, a partir do final da década de 1950 até a suspeita de sua açao teratogênica, em bases epidemiológicas, por Lenz e McBride, publicada em novembro de 1961, e provocando cerca de 1O.OOO vítimas mundiais. Paralelamente ao amplo dano teratológico causado pela droga, analisou-se sua repercussao revolucionária sobre a evoluçao metodológica dos levantamentos epidemiológicos, técnicas anamnésticas e, principalmente, na avaliaçao dos efeitos embriotóxicos de novos medicamentos e agentes terapêuticas utilizados por gestantes, estabelecendo as bases modernas da Teratologia Experimental e recapitulando o desenvolvimento da Ciência em face de problemas práticos surgidos em determinados períodos históricos. Reviu-se a epidemiologia das malformaçoes congênitas de etiologia genética e causadas por agentes exógenos, principalmente aqueles representados por drogas e medicamentos responsáveis por inúmeros complexos sindrômicos malfonnativos. como o presente na síndrome da talidomida (ST). Apreciou-se a "Tragédia da Talidomida" no Brasil com base no levantamento epideniiológico contido no processo indenizatório das "Vítimas da Talidomida" brasileiras, através da sua análise histórica, desde a introduçao dos medicamentos contendo talidomida no país, sua comercializaçao e proibiçao, bem como a fundaçao de associaçoes de auxílio às "Vítimas da Talidomida". Finalmente, discutiu-se o diagnóstico diferencial da ST e de inúmeros complexos malformativos e defeitos congênitos presentes nos 252 pretendentes a indenizaçao, analisando-se o tipo e a severidade das malformaçoes, os medicamentos utilizados, a evoluçao epidemiológica e a distribuiçao geográfica dos portadores da ST no Brasil.

[Macrosomia, macrocrania and motor disorders in childhood, Sotos syndrome (McKusick 11755): report of 7 cases and review of clinical aspects of 198 reported cases]. / Macrossomia, macrocrania e incoordenação motora da infância: síndrome de Sotos (McKusick 11755): estudo de 7 casos e revisão de aspectos clínicos de 198 casos publicados.

Children with Sotos syndrome have growth acceleration, macrocephaly, acromegaloid features and delay in neuropsychomotor development during infancy. Syndrome delineation and differential diagnosis are based on evaluation of phenotypic characteristics and evolutive history of the patients. Seven patients with this syndrome are reported, and the relative occurrence of the phenotypic characteristics present in 198 reported cases are reviewed. Motor difficulties present in those patients during early infancy are responsible for the poor performance on IQ tests. Oriented stimulation should be encouraged in order to help the affected children to overcome their initial difficulties and to achieve normal scholarity and life performance.

Macrossomia, macrocrania e incoordenaçäo motora da infância: síndrome de sotos (McKusick 11755); Estudo de 7 casos e revisäo de aspectos clínicos de 198 casos publicados / Macrosomia, macrocrania and motor disordes in childhood: sotos syndrome (McKusick 11755), report of 7 cases and review of clinical aspects of 198 report cases

Crianças com síndrome de Sotos apresentam aceleraçäo do crescimento, macrocrania, padröes acromegalóides e dificuldades iniciais no desenvolvimento neuropsicomotor. A delineaçäo da síndrome e o diagnóstico diferencial estäo baseados na avaliaçäo das características clínicas e no histórico evolutivo desses pacientes. Sete pacientes com síndrome de Sotos säo descritos, bem como revistas as características clínicas presentes em 198 pacientes da literatura. As dificuldades motoras presentes durante a primeira infância nos pacientes com síndrome de Sotos säo responsáveis pelo mau desempenho destas crianças nos testes de QI. A estimulaçäo especializada deve ser encorajada para ajustar os afetados a superarem suas dificuldades iniciais

In vitro cytogenetic effects of cannabidiol on human lymphocyte cultures

Investigou-se o efeito in vitro do canabidiol (CBD) sobre o índice mitótico e a frequência de células com aberraçöes cromossômicas numéricas e/ou estruturais, em culturas de linfócitos humanos. Em uma primeira fase o CBD foi dissolvido em álcool etílico absoluto (0,01 ml/ml de meio) nas concentraçöes de 0,001, 0,01 0,1, e 10,0 microng de CBD/ml de meio e, na segunda fase, o etanol foi evaporado antes de ser adicionado o meio de cultura. O efeito clastogênico do CBD foi maior quando associado ao álcool. A açäo do etanol foi predominantemente anti-mitogênica enquanto o CBD teve efeito mais nítido sobre a produçäo de células com aberraçöes cromossômicas. Após a evaporaçäo do etanol, a proporçäo de células com aberraçöes cromossômicas estruturais manteve uma relaçäo aproximadamente crescente com o aumento da taxa de CBD

A clinico-genetic investigation of Leydig cell hypoplasia.

We report on a kindred including a patient (46,XY) with typical manifestations of Leydig cell hypoplasia who was born to parents who were first cousins. A sister had secondary amenorrhea possibly due to primary ovarian dysfunction. Analysis of six pedigrees fits to a male-limited autosomal recessive pattern of inheritance; its implication for the mutational dynamics in the populations is evaluated.

Penta-x syndrome: a comparative study

Investigam-se comparativamente 25 indivíduos com pentassomia do X até entäo descritos na literatura. A etiologia da síndrome a partir de duas näo-disjunçöes sucessivas na oogênese foi considerada mais provável em conformidade com sua incidência muito rara, provavelmente inferior a 10**-6. Considerou-se que os óbitos prematuros determinados por cardiopatias congênitas e os acometimentos por doenças infecciosas devem ser responsáveis pela baixa taxa de sobrevivência que diminui a prevalência das pacientes na populaçäo adulta, de modo que a síndrome é principalmente diagnosticada na infância e, menos frequentemente, no nascimento. O tempo de gestaçäo é normal mas a síndrome determina baixo peso ao nascimento. Sua incidência predomina no 1§ nascimento e a razäo sexual na irmandade parece favorecer o sexo feminino, embora a idade dos pais näo seja diferente daquela nos nascimentos normais. O desconhecimento do cariótipo prejudica o diagnóstico diferencial, uma vez que muitos sinais clínicos observados nos recém-nascidos penta-X simulan síndromes hereditárias (Turner, Larsen, Down). A caracterizaçäo sindrômica é comprometida pelos sinais clínicos dependentes da idade, anamneses orientadas com objetivos específicos e avaliaçäo subjetiva desses sinais, entre outros fatores. Com base na sua ocorrência relativa em 25 pacientes, os defeitos identificados na síndrome do penta-X foram classificados em três grupos: Sinais de 1ª ordem: TRC muito baixo (média = 70), retardo psicomotor (QI médio = 45), hipertelorismo ocular, abertura inclinada dos olhos (inclinaçäo mongólica), malformaçäo dos pés, pregas epicânticas, pescoço curto, nariz grosso e achatado, alteraçöes dentárias, e superposiçäo dos artelhos. Sinais de 2ª ordem: microcefalia e/ou braquicefalia, palato ogival, prega simiesca, malformadas ou com implantaçäo baixa, implantaçäo baixa dos cabelos na nuca, pelve...

Penta-X sindrome: a follow-up study.

Relata-se seguimento de dez anos de uma paciente com pentassomia do cromossomo X a fim de delinear a sindrome do penta-X do ponto de vista clinico-genetico. Os sinais clinicos mais conspicuos foram: deficiencia mental e retardo do desenvolvimento severos, contagem total das linhas dermatologicas digitais (TRC)muito baixa,hipertelorismo ocular, malformacoes dos pes, dobras epicanticas, clinodactilia do 5o.dedo da mao, cardiopatia congenita, abertura ocular inclinada (inclinacao mongolica), pescoco curto, nariz grosso e achatado, alteracoes dentarias, microcefalia, aboboda palatina elevada (palato ogival), inaptidao para articulacao da fala, prega simiesca e orelhas com implantacao baixa.A maioria desses sinais podem tambem ser achada em outras disgenesias determinadas por aneuploidias cromossomicas de modo que as aberracoes cromossomicas devem primariamente provocar disturbio genico que impede a canalizacao normal do desenvolvimento embrionario das caracteristicas biologicas mais instaveis na populacao

[Sjögren-Larsson syndrome. Clinical and laboratory study of 2 cases]. / Síndrome de Sjögren-Larsson. Estudo clínico e laboratorial de dois casos.

Two cases of Sjögren-Larsson syndrome are reported. In analysing the clinical symptoms and laboratory data the authors established the diagnosis of this rare entity which has an autosomal recessive kind of inheritance.

Sindrome de Sjogren-Larsson: estudo clinico e laobratorial de dois casos. / Sjogren-Larsson syndrome: clinical and laboratorial study of 2 cases

Sao registrados dois casos, irmaos e um de cada sexo, com ictiose de aparecimento precose, deficiencia mental, diplegia espatica e alteracoes nos fundos oculares. A associacao destes sinais sem outros concomitantes levam ao diagnostico do sindrome de Sjogren e Larsson