Eumycetoma caused by Curvularia lunata in a dog

Curvularia lunata was cultured from black granules found in granulomatous tumefactions excised from the subcutis of a three year old Medium Schnauzer dog. Draining sinuses were present in some of the tumefactions. Accordingly the diagnosis of eumycotic mycetoma was made. This diagnosis was confirmed by histopathological examination. During the four years following the first surgical intervention, several more similar tumefactions were excised on three different occasions. The dog died of chronic renal failure at the age of 8 years. There was no bone involvement or visceral diffusion of the fungus. The granules were examined by scanning electron microscopy. Immunoglobulins in the dog's serum, assessed by a qualitative test, proved to be equal to immunoglobulins in the serum of a control dog. Precipitating antibodies against C. lunata were not found. The dog was treated for 150 days with itraconazole. In spite of good initial results, recurrence of the fungal lesions were observed after the treatment's interruption. Further treatment with itraconazole for 45 days proved ineffective. No side effects of the drug were observed. This is, to the best of our knowledge, the first case in which C. lunata is identified as the causative agent of an animal eumycetoma.     

Prevalence of cystic fibrosis mutations in Israeli Jews

The aim of this study was to evaluate the screening policies of cystic fibrosis (CF) in the Jewish population. The prevalence of mutations that account for CF in Israel have been defined in the past by determining the frequency of CF mutations in affected individuals. This study is a population-based study and is, therefore, different from previous patient-based studies. We found that the CF mutations D1152H, W1089X, and 405 + IG-->A were present in some ethnic groups in which no CF patients carrying these mutations were reported. These facts necessitate a reevaluation of the screening policy regarding the ethnic groups in Israel. We studied 9,430 healthy Jewish Israeli individuals of 36 countries of origin. The prevalence of CF mutations was 1:19, 1:19, 1:28, and 1:42 for the Ashkenazi, Sephardi, North African, and Eastern Jews, respectively. CF mutations were identified in 374 (4.0%) individuals. These included 173 (46.3%) carriers of the W1282X mutation; 110 (29.4%) found to carry delF508; 23 (6.1%) who carried G542X; 22 (5.9%) who carried 3849 + 10Kb (C-->T; 20 (5.3%) who carried D1152H; 10 (2.7%) who carried N1303K; 11 (2.9%) who carried 405 + IG-->A; 4 (1.1%) who carried W1089X; and one (0.3%) who carried S549R. No carriers were detected for the 1717-1G-->A, G85E, and T360K mutations, which were tested for in 7,383, 1,558, and 41 individuals, respectively.     

Behavioral analysis ofDrosophila mutants displaying abnormal male courtship

We describe six recessive autosomal male sterile mutations inDrosophila, generated by mobilization of single P-elements, exhibiting abnormal male courtship behavior. Detailed analysis of courtship behavior elicited by virgin wild type females indicated that five of the six mutants are affected in the early steps of courtship. The sixth mutant is blocked at the step of attempted copulation which occurs later in the courtship sequence. All of the mutants have normal olfactory responses and normal locomotor activity. No defect in the visual modality has been observed for the five mutants affected in the initiation of courtship. The mutant blocked at attempted copulation lacks the ‘on’ and ‘off’ transients, but this appears to be due to genetic background rather than the mutation itself. Abnormal spermatogenesis was observed in five of the mutants. Spermatogenic defects vary and include lesions in the proliferation of the germline, in meiosis, and in the differentiation and maturation of the spermatids into motile sperm.     

The protein phosphatases of Drosophila melanogaster and their inhibitors

Protein phosphatases-1, 2A and 2B have been identified in membrane and soluble fractions of Drosophila melanogaster heads. Similarities between Drosophila and mammalian protein phosphatase-1 included specificity for the beta subunit of phosphorylase kinase, sensitivity to inhibitor-1 and inhibitor-2, inhibition by protamine, retention by heparin-Sepharose and selective interaction with membranes. In addition, an inactive form of protein phosphatase-1, termed protein phosphatase-1I, was detected in the soluble fraction that could be activated by preincubation with MgATP and mammalian glycogen synthase kinase-3. Inhibitor-2 partially purified from Drosophila had an identical molecular mass to its mammalian counterpart, and recombined with mammalian protein phosphatase-1 to form a hybrid protein phosphatase-1I. Similarities between Drosophila and mammalian protein phosphatase-2A included preferential dephosphorylation of the alpha subunit of phosphorylase kinase, insensitivity to inhibitors-1 and -2, activation by protamine, exclusion from heparin-Sepharose and apparent molecular mass. A Ca2+-dependent calmodulin-stimulated protein phosphatase (protein phosphatase-2B) that was inhibited by trifluoperazine was identified in the soluble fraction. The remarkable similarities between Drosophila protein phosphatases and their mammalian counterparts are indicative of strict phylogenetic conservation and demonstrate that the procedures used to classify mammalian protein phosphatases have a wider application. Characterisation of the Drosophila phosphatases will facilitate genetic analysis of dephosphorylation systems and their possible roles in neuronal and behavioural plasticity in Drosophila.     

courtless, the Drosophila UBC7 homolog, is involved in male courtship behavior and spermatogenesis

The courtless (col) mutation disrupts early steps of courtship behavior in Drosophila males, as well as the development of their sperm. Most of the homozygous col/col males (78%) do not court at all. Only 5% perform the entire ritual and copulate, yet these matings produce no progeny. The col gene maps to polytene chromosome band 47D. It encodes two proteins that differ in their carboxy termini and are the Drosophila homologs of the yeast ubiquitin-conjugating enzyme UBC7. The col mutation is caused by an insertion of a P element into the 3' UTR of the gene, which probably disrupts translational regulatory elements. As a consequence, the homozygous mutants exhibit a six- to sevenfold increase in the level of the COL protein. The col product is essential, and deletions that remove the col gene are lethal. During embryonic development col is expressed primarily in the CNS. Our results implicate the ubiquitin-mediated system in the development and function of the nervous system and in meiosis during spermatogenesis.     

The structure of protein phosphatase 2A is as highly conserved as that of protein phosphatase 1

cDNA coding for protein phosphatase 2A (PP2A) has been isolated from Drosophila head and eye imaginal disc libraries. Drosophila PP2A mRNA is expressed throughout development, but is most abundant in the early embryo. The cDNA hybridises to a single site on the left arm of the second chromosome at position 28D2-4. The deduced amino acid sequence (309 residues) of Drosophila PP2A shows 94% identity with either rabbit PP2A alpha or PP2A beta, indicating that PP2A may be the most conserved of all known enzymes.     

The role of alginate in Pseudomonas aeruginosa EPS adherence, viscoelastic properties and cell attachment

Among various functions, extracellular polymeric substances (EPS) provide microbial biofilms with mechanical stability and affect initial cell attachment, the first stage in the biofilm formation process. The role of alginate, an abundant polysaccharide in Pseudomonas aeruginosa biofilms, in the viscoelastic properties and adhesion kinetics of EPS was analyzed using a quartz crystal microbalance with dissipation (QCM-D) monitoring technology. EPS was extracted from two P. aeruginosa biofilms, a wild type strain, PAO1, and a mucoid strain, PAOmucA22 that over-expresses alginate production. The higher alginate content in the EPS originating from the mucoid biofilms was clearly shown to increase both the rate and the extent of attachment of the EPS, as well as the layer's thickness. Also, the presence of calcium and elevated ionic strength increased the thickness of the EPS layer. Dynamic light scattering (DLS) showed that the presence of calcium and elevated ionic strength induced intermolecular attractive interactions in the mucoid EPS molecules. For the wild type EPS, in the presence of calcium, an elevated shift in the distribution of the diffusion coefficients was observed with DLS due to a more compacted conformation of the EPS molecules. Moreover, the alginate over-expression effect on EPS adherence was compared to the effect of alginate over-expression on P. aeruginosa cell attachment. In a parallel plate flow cell, under similar hydraulic and aquatic conditions as those applied for the EPS adsorption tests in the QCM-D flow cell, reduced adherence of the mucoid strain was clearly observed compared to the wild type isogenic bacteria. The results suggest that alginate contributes to steric hindrance and shielding of cell surface features and adhesins that are known to promote cell attachment.     

Susceptibility of Psammomys obesus and Meriones tristrami to tachyzoites of Neospora caninum

The susceptibility of Psammomys obesus (sand rat) and Meriones tristrami (Tristram's jird) to Neospora caninum was investigated by subcutaneous (s.c.) and intraperitoneal (i.p.) inoculation of 10-fold doses of culture-derived tachyzoites. Groups of 5 animals were inoculated with doses of 10-10(7) parasites via each route of inoculation. All but 2 of the sand rats inoculated with doses of 10-10(4) parasites succumbed to the infection by 7-18 days postinfection. All jirds inoculated with 10(7) tachyzoites succumbed by 5-16 days postinfection and those inoculated with 10(6) tachyzoites by 9-25 days. A considerable proportion of the jirds inoculated with 10-10(5) tachyzoites survived. Fibrinous peritonitis with ascites containing numerous tachyzoites was observed in the i.p.-inoculated sand rats and jirds that succumbed to the infection. In the jirds, tachyzoites were also found in pleural exudate. A considerable number (42.8%) of the jirds inoculated s.c. or i.p. exhibited neuromuscular symptoms, expressed in ataxia, head tilt, circling movement, and posterior paralysis. Seven successive passage of tachyzoites were achieved in sand rats with doses of 10(5) parasites and in jirds with doses of 10(7) parasites. All surviving jirds became seroconverted and were immune to lethal challenge.     

The COP9 signalosome is essential for development of Drosophila melanogaster.

The COP9 signalosome (originally described as the COP9 complex) is an essential multi-subunit repressor of light-regulated development in plants [1] [2]. It has also been identified in mammals, though its role remains obscure [3] [4] [5]. This complex is similar to the regulatory lid of the proteasome and eIF3 [5] [9] [10] [11] [12] and several of its subunits are known to be involved in kinase signaling pathways [4] [6] [7] [8]. No proteins homologous to COP9 signalosome components were identified in the Saccharomyces cerevisiae genome, suggesting that the COP9 signalosome is specific for multi-cellular differentiation [13]. In order to reveal the developmental function of the COP9 signalosome in animals, we have isolated Drosophila melanogaster genes encoding eight subunits of the COP9 signalosome, and have shown by co-immunoprecipitation and gel-filtration analysis that these proteins are components of the Drosophila COP9 signalosome. Yeast two-hybrid assays indicated that several of these proteins interact, some through the PCI domain. Disruption of one of the subunits by either a P-element insertion or deletion of the gene caused lethality at the late larval or pupal stages. This lethality is probably a result of numerous pleiotropic effects. Our results indicate that the COP9 signalosome is conserved in invertebrates and that it has an essential role in animal development.