Analysis of conditional paralytic mutants in Drosophila sarco-endoplasmic reticulum calcium ATPase reveals novel mechanisms for regulating membrane excitability.

Individual contributions made by different calcium release and sequestration mechanisms to various aspects of excitable cell physiology are incompletely understood. SERCA, a sarco-endoplasmic reticulum calcium ATPase, being the main agent for calcium uptake into the ER, plays a central role in this process. By isolation and extensive characterization of conditional mutations in the Drosophila SERCA gene, we describe novel roles of this key protein in neuromuscular physiology and enable a genetic analysis of SERCA function. At motor nerve terminals, SERCA inhibition retards calcium sequestration and reduces the amplitude of evoked excitatory junctional currents. This suggests a direct contribution of store-derived calcium in determining the quantal content of evoked release. Conditional paralysis of SERCA mutants is also marked by prolonged neural activity-driven muscle contraction, thus reflecting the phylogenetically conserved role of SERCA in terminating contraction. Further analysis of ionic currents from mutants uncovers SERCA-dependent mechanisms regulating voltage-gated calcium channels and calcium-activated potassium channels that together control muscle excitability. Finally, our identification of dominant loss-of-function mutations in SERCA indicates novel intra- and intermolecular interactions for SERCA in vivo, overlooked by current structural models.

[Continuous nebulization with terbutaline sulfate under tent inhalation. Evaluation of the efficacy in children 2 to 5 years of age in asthmatic crises]. / Nébulisation continue avec sulfate de terbutaline sous tente d'inhalation. Evaluation de l'efficacité chez l'enfant de 2 á 5 ans en crise d'asthme.

This study investigated the efficacy of a system for continuous nebulization of terbutaline sulphate in the treatment of acute asthmatic crises in children. The equipment consisted of a condensation nebulizer attached to a 40 liter acrylic tent placed around the patient's head. A prospective, randomized and open clinical trial was conducted. Twenty eight children, 2 to 5 year-old, in acute asthmatic crises were selected. Fourteen were nebulized with terbutaline sulphate while in the control group the aerosolization was proceeded only with half diluted physiologic serum. All patients were administered aminophyline intravenously. The parameter used to evaluate the efficacy of the terbutaline sulphate nebulizing system was clinical improvement measured by the Wood-Downes Score. Two additional parameters indicating terbutaline sulphate absorption were used: reduction of potassium seric levels and positive chronotropic effect. The group treated with terbutaline sulphate showed greater clinical improvement than control group at the 12 hour protocol evaluation as well as lower seric potassium level. A positive chronotropic effect was also observed at the final protocol evaluation. The data showed, preliminarily, that (a) the system for continuous nebulization of terbutaline sulphate was effective in treatment of children's acute asthmatic crises, and (b) there was evidence attesting to the absorption of terbutaline sulphate by the children treatment with it.

[Management of febrile infants younger than 2 months of age at the Emergency Care Unit: diagnosis aspects and therapeutics]. / Febre no lactente jovem atendido em Serviço de Emergência: aspectos diagnósticos e terapêuticos.

82 febrile young infants were studied, prospectively, at the Emergency Service in Hospital Universitário-University of São Paulo. All the children were kept at the Emergency ward for 24 hours. Clinical and laboratory investigations were performed and when necessary, administration of antibiotic agents were started. 18 infants exhibited potentially severe bacterial infections (21.9%). Several important disorders were recognized in 40 infants (48.8%). All infants were followed until the end of the febrile episode: 20 children as inpatients and 62 as outpatients. 38 infants received antibiotic therapy (46.3%). Evolution was satisfactory in all patients. The authors detected in young febrile infants potentially dangerous clinical conditions that need close observation, laboratorial investigation and frequently antimicrobial therapy. The observation period at the Emergency ward was important to allow these procedures and to decide about hospitalization need.

Diarreia causada por Shigella: aspectos clinicos e terapeuticos / Diarrhea caused by Shigella: clinical and therapeutical aspects

Os autores estudaram diarreias graves causadas por Shigella sp que foram atendidas no Servico de Emergencias do Hospital Universtario da USP durante tres anos. Esse agente foi isolado de 65 casos de diarreia aguda que corresponderam a 3,1 por cento dos casos graves e 22,3 por cento dos quadros clinicos de disenteria. A S.flexneri foi a mais isolada, seguida pela S.sonnei, na proporcao de 3:1...

Nonequivalent requirements for PS1 and PS2 integrin at cell attachments in Drosophila: genetic analysis of the alpha PS1 integrin subunit.

We report on the generation and phenotype of mutant alleles of multiple edematous wings (mew), the gene encoding the alpha PS1 subunit of the PS1 integrin of Drosophila. None of the six alleles examined makes detectable protein, and one allele results from a chromosome break near the middle of the translated sequence, so we are confident that we have described the null phenotype. In contrast to if (alpha PS2) and mys (beta PS) mutants, most mutant mew embryos hatch, to die as larvae. Mutant mew embryos display abnormal gut morphogenesis but, unlike mys or if embryos, there is no evidence of defects in the somatic muscles. Thus, the complementary distributions of PS1 (alpha PS1 beta PS) and PS2 (alpha PS2 beta PS) integrin on tendon cells and muscle, respectively, do not reflect equivalent requirements at the myotendinous junction. Dorsal herniation, characteristic of the mys lethal phenotype, is not observed in mew or in mew if embryos. Clonal analysis experiments indicate that eye morphogenesis is disrupted in mew clones, but if clones in the eye are relatively normal in morphology. Adult wings display blisters around large dorsal but not ventral mew clones. In contrast to dorsal mys clones, small mew patches do not necessarily display morphogenetic abnormalities. Thus, another integrin in addition to PS1 appears to function on the dorsal wing surface.

Differences in the acquired resistance of dogs, hamsters, and guinea pigs to repeated infestations with adult ticks Rhipicephalus sanguineus (Acari: Ixodidae)

Grupos experimentais de cäes, hamsters e cobaias sem contato anterior com carrapatos, sofreram três infestaçöes consecutivas por carrapatos Rhipicephalus sanguineus adultos e a resistência adquirida comparada com base na variaçäo de alguns dos parâmetros biológicos da fêmea do carrapato. Os resultados mostraram que hamsters e cobaias principalmente, desenvolvem uma reaçäo imune muito eficiente a esta espécie de carrapato como demonstrado por uma queda altamente significativa na taxa de eficiência da fêmea em converter sua reserva alimentar em ovos e larvas da primeira para as segunda e terceira infestaçöes. Já cäes foram incapazes de desenvolver tal resistência. Neste hospedeiro a performance das fêmeas dos carrapatos foi similar durante todas as infestaçöes, havendo até uma tendência de melhora com a sucessäo das infestaçöes. Estes resultados reforçam a necessidade de estudos comparativos sobre a resistência adquirida a carrapatos, envolvendo hospedeiros naturais e näo naturais, como forma de colocar em evidência mecanismos de defesa que possam estar alterados ou ocultos em relaçöes parasita-hospedeiro naturais

Immunisation of dogs, hamsters and guinea pigs against Rhipicephalus sanguineus using crude unfed adult tick extracts.

Naive experimental groups of dogs, hamsters and guinea pigs were inoculated three times subcutaneously with unfed adult extract of the tick Rhipicephalus sanguineus and challenged with adult R. sanguineus to evaluate resistance. The acquisition of resistance was based on alterations of some reproductive and feeding performance parameters of female ticks such as female and egg mass weights, engorgement, pre-oviposition and incubation periods, larval hatchability rate and efficiency rates of female ticks in converting their food reservoir to eggs and larvae. Dogs did not develop resistance under these experimental conditions; guinea pigs and hamsters, to a lesser extent, acquired an effective immunity to ticks as demonstrated by the impairment of the reproductive and feeding performance. However, the resistance induced by inoculation of the extract in the rodents seemed not to be as efficient as that induced by successive infestations.

Characterization of mutant alleles of myospheroid, the gene encoding the beta subunit of the Drosophila PS integrins.

This paper presents the characterization of nine alleles of myospheroid, which encodes the beta PS subunit of the Drosophila PS integrins. On Southern blots, the mysXB87, mysXN101 and mysXR04 genes yield restriction digest patterns similar to that seen for wild-type chromosomes, however the mys1 and mysXG43 genes contain detectable deletions. mys1, mysXB87 and mysXG43 make little or no stable protein product, and genetically behave as strong lethal alleles. For the mysXN101 mutation, protein product is seen on immunoblots and a reduced amount of beta PS protein is seen at muscle attachment sites of embryos; this mutant protein retains some wild-type function, as revealed by complementation tests with weak alleles. Protein is also seen on immunoblots from mysXR04 embryos, and this allele behaves as an antimorph, being more deleterious in some crosses than the complete deficiency for the locus. mysts2 and mysnj42 are typically lethal in various combinations with other alleles at high temperatures only, but even at high physiological temperatures, neither appears to eliminate gene function completely. The complementation behaviors of mysts1 and mysts3 are quite unusual and suggest that these mutations involve regulatory phenomena. For mysts3, the data are most easily explained by postulating transvection effects at the locus. The results for mysts1 are less straightforward, but point to the possibility of a chromosome pairing-dependent negative interaction.

Aggressive behavior in the home as a function of the age and sex of control-problem and normal children.

This cross-sectional study investigated the ability of age, sex, and clinic-referred or nonreferred status of children to account for variance in the performance of aggressive behavior. Two clinic-referred groups and one normative group of children, composed of 137 males and 86 females between the ages of 3 and 13, were observed during unstructured family interactions in the home setting. Measures of aggressive/aversive child behavior included a composite total aversive behavior (TAB) score, a physical aggression (PAB) score, a verbal aggression (VAB) score, a passive-dependent behavior (PDB) score, and a disobedience (DSB) score. The total regression model and referral status were significant for each of these dependent variables. Age was significant for each variable except VAB, and sex was significant only for PAB. Significant age X group interactions were obtained for TAB, PDB, and DSB. Rates of behavior clearly differentiated groups, but the relationship of age and sex of child to behavior rates was the same across groups. Decreases in all behaviors with increasing age, except for VAB, replicate findings from previous studies in preschool settings. However, the meager sex differences failed to replicate more robust findings generally reported in previous research.

Children at risk for delinquency: a follow-up comparison of aggressive children and children who steal.

This study compared the follow-up incidence of court-recorded nonstatus offenses for three groups of adolescent children. These children had been seen 2 to 9 years earlier for problems with aggression in the home (N = 21), for stealing problems (N = 25), or for normative comparisons (N = 14). The results showed that 77% of the children with stealing problems had court-recorded offenses. This was significantly higher than the aggressive children, whose rate did not differ from the normative sample. These findings suggested that young aggressive children were not at risk for adolescent court contact. Instead, it was the young child with identified stealing problems who was highly likely to become an official delinquent. It also appeared that parental reports of stealing events constituted a predictive measure of later criminal acts.