Toxicity of insecticides on Neotropical stingless bees Plebeia emerina (Friese) and Tetragonisca fiebrigi (Schwarz) (Hymenoptera: Apidae: Meliponini).

Use of pesticides in agroecosystems is considered a major cause of bees diversity losses in the Neotropics, where Plebeia emerina (Friese) and Tetragonisca fiebrigi (Schwarz) (Hymenoptera: Apidae: Meliponini) are wild pollinators of native and crop plants. The aim of this study was to know the acute lethal toxicity of acetamiprid, malathion, phosmet and spinosad insecticides on P. emerina and T. fiebrigi. We obtained the mean concentration and mean lethal dose (LC50 and LD50) and the mean survival of workers after oral and topical exposure to insecticides, respectively. The LC50 values (ng a.i./µl of diet) and the decreasing order of toxicity for P. emerina was spinosad (4.96) > malathion (18.75) > phosmet (97.33) > acetamiprid (4204.06), and for T. fiebrigi also was spinosad (5.65) > malathion (8.39) > phosmet (53.91) > acetamiprid (9841.32), when orally exposed. The LD50 values (ng a.i./bee) and the decreasing order of toxicity for P. emerina was spinosad (1.90) > malathion (10.90) > phosmet (19.54) > acetamiprid (6216.55) and for T. fiebrigi was malathion (29.29) ≥ spinosad (29.79) > phosmet (41.95) > acetamiprid (1421.23), when topically exposed. The mean survival (hours) of contaminated bees by malathion, phosmet, and spinosad, was 11.81, 7.20, and 12.32 for P. emerina and 8.55, 7.20, and 13.34 for T. fiebrigi when orally exposed; and was 4.87, 9.87 and 11.17 for P. emerina, and 4.87, 4.76, and 19.05 for T. fiebrigi when topically exposed. Malathion, phosmet, and spinosad were highly toxic, while acetamiprid was moderately toxic. Our results indicated that the insecticides tested, mainly malathion, phosmet, and spinosad may be harmful to P. emerina and T. fiebrigi, making it essential to propose measures to minimize their impact on wild pollinators.

Effects of Extrinsic, Intraspecific Competition and Host Deprivation on the Biology of Trichopria anastrephae (Hymenoptera: Diapriidae) Reared on Drosophila suzukii (Diptera: Drosophilidae).

The pupal parasitoid Trichopria anastrephae Lima (Hymenoptera: Diapriidae) shows potential to control Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), and understanding the behavior of this parasitoid in challenging environments is important to obtain a higher efficiency in mass rearing and in biological control programs. This study aimed to verify the effects of extrinsic intraspecific competition and the absence of host on the parasitism of T. anastrephae in D. suzukii pupae. Therefore, to evaluate the parasitism of T. anastrephae under intraspecific competition, groups of 20 pupae (24 h old) of D. suzukii were offered for different densities of parasitoids (1, 3, 5, or 10 couples) during a 7-day period. Whereas to evaluate the effects of host deprivation on parasitism of T. anastrephae, we tested different treatments: T1-no deprivation, T2-complete deprivation, T3-deprivation every other day, T4-deprivation for 3 days, and T5-deprivation for 7 days. The increase of density of parasitoids resulted in an increase of oviposition scars on pupae and a longer biological cycle, suggesting the occurrence of superparasitism. Increased density also resulted in a higher percentage of attacked pupae, but did not affect parasitoids emergence nor sex ratio. Host deprivation affected number of parasitized pupae, number and sex ratio of offspring, and the longevity of females. Based on our findings, competition among females do not impair offspring viability, and host deprivation for a period up to 7 days do not influence parasitism capacity, indicating that it can be used as a pre-release strategy.

[Alice in Wonderland syndrome as persistent aura of migraine and migraine disease starting]. / Sindrome de Alicia en el Pais de las Maravillas como aura persistente de migrana e inicio de enfermedad migranosa.

INTRODUCTION: Migraine with aura in children is often described, but communications of typical aura without headache are rare, and persistent aura and Alice in Wonderland syndrome are exceptional. CASE REPORT: A 8 years-old girl who experiences during a month one to three brief episodes a day during which she relates: 'I saw things as little and remote, sometimes they moved; one day I saw my sister's books turning bigger, and another day my father getting little as a doll; sometimes my doll's leg swinged, or the blind in the window got up and down'. Later these attacks spaced out to one each to days for another two weeks. With no previous episodes of headache, these start two days after the visual distortions disappeared, with clinical features of migraine without aura. There were antecedents of migraine in maternal line, and no previous trauma, epilepsy, drug ingestion or psychiatric disorders. Clinical examination, cranial RMI, and EEG were normal. CONCLUSION: Although Alice in Wonderland syndrome was described as a migraine aura, it is usually brief, and it is exceptional that it lasts longer than a week. We think this is the first description in a pediatric patient.

Distribuicao e frequencia de larvas de dermatobia hominis em peles de bovinos / Distribution and frequency of the larvae of the dermatobia hominis in cattle skin

A larva da Dermatobia hominis (Linnaeus Jr., 1781) (Diptera: cuterebridae) causa una miíase nodular subcutánea que provoca perfuracoes irreversíveis na pele; fato esse que compromete a qualidade do couro, causando prejuízos em sua comercializacao. O presente trabalho objetivou verificar a localizacao e a distribuicao das larvas na superfície corporal dos bovinos, determinando a frequencia das infestacoes com relacao ao sexo, idade e cor da pelagem. Foi realizado um levantamento em 8.124 peles de bovinos abatidos em frigorífico do município de Nilópolis, Estado do Rio de Janeiro, Brasil, para identificacao da localizacao e distribuicao das larvas. O couro teve a superfície dividida em quatro regioes: I (quadrante anterior esquerdo), II (quadrante anterior direito), III (quadrante posterior esquerdo), IV (quadrante posterior direiro). Registrou-se também a cor da pelagem e idade dos animais. Do total de couros examinados 84,8 por cento (6,888) estavam isentos de berne. A incidencia de parasitas na regiao I foi significativamente maior 33,4 por cento (3,029), na regiao II 30,9 por cento (2,796), na regiao III 20 por cento (1,813) na regiao IV 15,7 por cento (1,423). Com relacao a frequencia de ocorrencia por sexo, a presenca do berne foi significativamente maior nas femeas 16,7 por cento (342), do que nos machos 14,7 por cento (894). Em relacao a idade dos bovinos, nos animais adultos foram observados (15,4 por cento) dos nódulos, e nos jovens (12,1 por cento). A incidencia do berne por cor de pelagem foram mais frequentes na pelagem preta (18,1 por cento), preta e vermelha (15,4 por cento), preta e branca (15,3 por cento), vernelha (15,2 por cento), malhada (13,2 por cento) e cinza (11,8 por cento)

Cryoelectron-microscopy image reconstruction of symmetry mismatches in bacteriophage phi29.

A method has been developed for three-dimensional image reconstruction of symmetry-mismatched components in tailed phages. Although the method described here addresses the specific case where differing symmetry axes are coincident, the method is more generally applicable, for instance, to the reconstruction of images of viral particles that deviate from icosahedral symmetry. Particles are initially oriented according to their dominant symmetry, thus reducing the search space for determining the orientation of the less dominant, symmetry-mismatched component. This procedure produced an improved reconstruction of the sixfold-symmetric tail assembly that is attached to the fivefold-symmetric prolate head of phi29, demonstrating that this method is capable of detecting and reconstructing an object that included a symmetry mismatch. A reconstruction of phi29 prohead particles using the methods described here establishes that the pRNA molecule has fivefold symmetry when attached to the prohead, consistent with its proposed role as a component of the stator in the phi29 DNA packaging motor.

Structure of the bacteriophage phi29 DNA packaging motor.

Motors generating mechanical force, powered by the hydrolysis of ATP, translocate double-stranded DNA into preformed capsids (proheads) of bacterial viruses and certain animal viruses. Here we describe the motor that packages the double-stranded DNA of the Bacillus subtilis bacteriophage phi29 into a precursor capsid. We determined the structure of the head-tail connector--the central component of the phi29 DNA packaging motor--to 3.2 A resolution by means of X-ray crystallography. We then fitted the connector into the electron densities of the prohead and of the partially packaged prohead as determined using cryo-electron microscopy and image reconstruction analysis. Our results suggest that the prohead plus dodecameric connector, prohead RNA, viral ATPase and DNA comprise a rotary motor with the head-prohead RNA-ATPase complex acting as a stator, the DNA acting as a spindle, and the connector as a ball-race. The helical nature of the DNA converts the rotary action of the connector into translation of the DNA.

The crystal structure of bacillus cereus phosphonoacetaldehyde hydrolase: insight into catalysis of phosphorus bond cleavage and catalytic diversification within the HAD enzyme superfamily.

Phosphonoacetaldehyde hydrolase (phosphonatase) catalyzes the hydrolysis of phosphonoacetaldehyde to acetaldehyde and phosphate using Mg(II) as cofactor. The reaction proceeds via a novel bicovalent catalytic mechanism in which an active-site nucleophile abstracts the phosphoryl group from the Schiff-base intermediate formed from Lys53 and phosphonoacetaldehyde. In this study, the X-ray crystal structure of the Bacillus cereus phosphonatase homodimer complexed with the phosphate (product) analogue tungstate (K(i) = 50 microM) and the Mg(II) cofactor was determined to 3.0 A resolution with an R(cryst) = 0.248 and R(free) = 0.284. Each monomer is made up of an alpha/beta core domain consisting of a centrally located six-stranded parallel beta-sheet surrounded by six alpha-helices. Two flexible, solvated linkers connect to a small cap domain (residues 21-99) that consists of an antiparallel, five-helix bundle. The subunit-subunit interface, formed by the symmetrical packing of the two alpha8 helices from the respective core domains, is stabilized through the hydrophobic effect derived from the desolvation of paired Met171, Trp164, Tyr162, Tyr167, and Tyr176 side chains. The active site is located at the domain-domain interface of each subunit. The Schiff base forming Lys53 is positioned on the cap domain while tungstate and Mg(II) are bound to the core domain. Mg(II) ligands include two oxygens of the tungstate ligand, one oxygen of the carboxylates of Asp12 and Asp186, the backbone carbonyl oxygen of Ala14, and a water that forms a hydrogen bond with the carboxylate of Asp190 and Thr187. The guanidinium group of Arg160 binds tungstate and the proposed nucleophile Asp12, which is suitably positioned for in-line attack at the tungsten atom. The side chains of the core domain residue Tyr128 and the cap domain residues Cys22 and Lys53 are located nearby. The identity of Asp12 as the active-site nucleophile was further evidenced by the observed removal of catalytic activity resulting from Asp12Ala substitution. The similarity of backbone folds observed in phosphonatase and the 2-haloacid dehalogenase of the HAD enzyme superfamily indicated common ancestry. Superposition of the two structures revealed a conserved active-site scaffold having distinct catalytic stations. Analysis of the usage of polar amino acid residues at these stations by the dehalogenases, phosphonatases, phosphatases, and phosphomutases of the HAD superfamily suggests possible ways in which the active site of an ancient enzyme ancestor might have been diversified for catalysis of C-X, P-C, and P-O bond cleavage reactions.

Crystallization and preliminary crystallographic analysis of phosphonoacetaldehyde hydrolase.

Phosphonoacetaldehyde hydrolase, a C-P bond-cleaving enzyme which utilizes an unusual bicovalent catalytic strategy, has been crystallized by the hanging-drop vapor-diffusion method using PEG 4000 as the precipitant. The crystals belong to the monoclinic system and belong to space group C2, with unit-cell parameters a = 210.5, b = 45.5, c = 64.7 A, beta = 105.0 degrees. The asymmetric unit contains a dimer related by a non-crystallographic dyad. In addition to a 2.7 A native data set, the following data sets have been collected: a 2.4 A data set from crystals complexed with the intermediate analog vinyl sulfonate, a 3.0 A three-wavelength MAD data set from crystals complexed with the product analog WO(4)(2-), as well as several heavy-atom data sets to 3.0 A or better, of which only three have proven useful for MIR calculations. Examination of the native Patterson map revealed NCS that made previously uninterpretable derivative data useful. Independent phase sets were first calculated and refined for the MAD and MIR experiments separately and were then combined. The combined phase set was further improved by solvent flattening, histogram matching and NCS averaging. Interpretation of the resulting electron-density map is currently under way.

[Supra-ampullary neoplasms of the biliary tract. Analysis of 16 cases]. / Neoplasias das vias biliares supra-ampulares. Análise de 16 casos.

A series of sixteen patients with supra-ampullary tumours of the biliary tree is reviewed. There was no sex difference and 9 from 16 were more than 60 years old. The clinical picture was insidious in 10 patients with dyspeptic symptoms; and started suddenly in 6; jaundice was the first symptom in 3, and was always present at admission. The delay for a correct diagnosis was 5 months since the beginning of the symptoms, and it was obtained by direct visualization of the biliary tree (PTC or/and ERCP). Surgical removal of the tumour was possible only in 3 patients. Microscopic diagnosis was obtained in 12 patients: 11 carcinomas (6 non-differentiated) and 1 lymphoma. Local metastasis were found only in 5 cases, with a mean evolution longer than 6 months. Until now, surgery has been disappointing; a more aggressive diagnostic approach conducting to earlier surgical treatment can probably improve the results.

Neoplasias das vias biliares supraampulares. Analise de 16 casos. / Supra-ampullary neoplasms of the biliary tract. Analysis of 16 cases

Apresenta-se uma serie de 16 doentes com neoplasia das vias biliares supra-ampulares (NVB), entre 60 com tumores das vias biliares observados num Servico de Medicina Interna no periodo de cinco anos (19751979). A distribuicao foi igual nos dois sexos e nove dos 16 doentes tinham mais de 60 anos. O quadro clinico iniciou-se gradualmente, por sintomas inespecificos, em 10 doentes; foi subito em seis. Ictericia foi o primeiro sinal em tres, mas estava sempre presente a data do internamento. O diagnostico foi, em geral, feito cerca de cinco meses apos o inicio das queixas e foi obtido por visualizacao direta das vias biliares: colangiografia percutanea transhepatica (CPT) e/ou colangiografia endoscopica retrogada (CPRE). Foi possivel a resseccao do tumor apenas em tres doentes. O tipo histologico dos tumores foi conhecido em 12: 11 adenocarcinomas (seis indeferenciados) e um linfoma. Encontraram-se metastases regionais apenas em cinco casos, com um tempo medio de evolucao superior a seis meses. A lenta evolucao destes tumores justifica uma atitude diagnostica mais agressiva para antecipar a terapeutica cirurgica