Leishmania tarentolae: Utility as an in vitro model for screening of antileishmanial agents

Primary screens for antileishmanial compounds use Leishmania species pathogenic to humans that must be handled under biosafety conditions that cannot be adopted or guaranteed everywhere. Leishmania tarentolae, a parasite isolated from the gecko Tarentolae annularis, has not been considered pathogenic to humans. Promastigotes of L. tarentolae have been previously used as a eukaryotic expression system for the production of recombinant proteins and in the amplification of genes involved in resistance to antileishmanial drugs. To validate the use of this Leishmania species in the screening of antileishmanial drugs, the sensitivity of axenic and intracellular amastigotes of L. tarentolae was compared to the sensitivity showed by Leishmania species causative of human leishmaniasis. The ability of L. tarentolae to grow as axenic amastigotes is first described while its ability to infect several mammalian cells has been confirmed. L. tarentolae amastigotes offer a suitable model for the in vitro screening of compounds for antileishmanial activity.     

Stoned olive pomace fermentation with Pleurotus species and its evaluation as a possible animal feed

The use of stoned olive pomace (SOP) as an unconventional feedstuff for livestock is limited by its inherently low crude protein (CP) content and by the presence of anti-nutritional compounds such as phenols. Aim of this study was to assess whether solid-state fermentation of SOP with selective lignin-degrading fungi might ameliorate nutritional properties of the waste. Incubation of SOP, mixed (25%, w/w) with various conventional feedstuffs (i.e., wheat bran, wheat middlings, barley grains, crimson clover, wheat flour shorts and field beans), with Pleurotus ostreatus and Pleurotus pulmonarius led to significant CP increases, ranging from 7 to 29%, and marked removal (from ca. 50–90%) of phenols after 6 weeks. Both species, however, led to moderate delignification associated with significant consumption of hemicelluloses. Consequently, no improvements of both organic matter digestibility (OMD) and net energy of SOP–feedstuff mixtures occurred after the fungal colonization.     

Echinate fossil pollen of Asteraceae from the Late Oligocene of Patagonia: an assessment of its botanical affinity

The Late Oligocene Mutisiapollis telleriae, which is the oldest echinate fossil pollen of Asteraceae from Patagonia, was tentatively related to the subfamily Mutisioideae. A detailed comparison of M. telleriae with extant asteraceous pollen indicates strong similarities with both Mutisioideae (in particular the Gongylolepis type) and Carduoideae (some genera of Carduinae) subfamilies. This morphotype, as an example of the exceptional diversity of fossil pollen of Asteraceae found in Patagonia, contributes to the knowledge of the early history of the family.     

Spontaneous serial fractures of metatarsal bones in female patient with rheumatoid arthritis on long-term steroid therapy

Low-dose oral steroid therapies are very effective in active rheumatoid arthritis (RA), reducing disease activity in acute crisis either while waiting for disease-modifying antirheumatic drugs (DMARDs) to take effect or if it was slow in response to DMARDs. However, long-term steroid therapies are associated with serious side effects, such as osteoporotic reduction of bone mass and frequent fractures. This paper reports a female patient who has suffered RA treated with low-dose oral steroid therapy in a long-term period. Suddenly, she developed severe pain and oedema of forefeet during home distance level walking, with no history of trauma. The diagnosis of spontaneous serial fractures of the 2nd to 4th metatarsal (MT) bone bilaterally was performed by feet radiography. Furthermore, in widening the diagnostic approaches the authors had performed diagnostic musculoskeletal ultrasound to exclude metatarsophalangeal joint effusion and exacerbation of RA. They also made a static analysis of feet on the electronic baropodometer system in order to register biomechanical changes in bipedal standing. One year after, the same diagnostic procedures were done, on which occasion the healing of fractures were verified, with better results in biomechanical static analysis of the feet but without complete regression of static disbalance. This could lead to further disturbances during level walking and daily activities. This paper reports a unique case of the RA patient on long-term low-dose steroid therapy with previously unreported sites of spontaneous metatarsal fractures of feet which causes further static disbalance; consequently the patient might experience problems in every-day life activities.     

The Decrease on Na+, K+-ATPase Activity in the Cortex, but not in Hippocampus, is Reverted by Antioxidants in an Animal Model of Sepsis

In the present study, we investigated whether sepsis induced by cecal ligation and puncture (CLP) modifies Na⁺, K⁺-ATPase activity, mRNA expression, and cerebral edema in hippocampus and cerebral cortex of rats and if antioxidant (ATX) treatment prevented the alterations induced by sepsis. Rats were subjected to CLP and were divided into three groups: sham; CLP??rats were subjected to CLP without any further treatment; and ATX?CCLP plus administration of N-acetylcysteine plus deferoxamine. Several times (6, 12, and 24) after CLP or sham operation, the rats were killed and hippocampus and cerebral cortex were isolated. Na⁺, K⁺-ATPase activity was inhibited in the hippocampus 24?h after sepsis, and ATX treatment was not able to prevent this inhibition. The Na⁺, K⁺-ATPase activity also was inhibited in cerebral cortex 6, 12, and 24?h after sepsis. No differences on Na⁺, K⁺-ATPase catalytic subunit mRNA levels were found in the hippocampus and cerebral cortex after sepsis. ATX treatment prevents Na⁺, K⁺-ATPase inhibition only in the cerebral cortex. Na⁺, K⁺-ATPase inhibition was not associated to increase brain water content. In conclusion, the present study demonstrated that sepsis induced by CLP inhibits Na⁺, K⁺-ATPase activity in a mechanism dependent on oxidative stress, but this is not associated to increase brain water content.     

PHA production, from bacteria to plants.

The genes encoding the polyhydroxyalkanoate (PHA) biosynthetic pathway in Ralstonia eutropha (3-ketothiolase, phaA or bktB; acetoacetyl-CoA reductase, phaB; and PHA synthase, phaC) were engineered for plant plastid targeting and expressed using leaf (e35S) or seed-specific (7s or lesquerella hydroxylase) promoters in Arabidopsis and Brassica. PHA yields in homozygous transformants were 12-13% of the dry mass in homozygous Arabidopsis plants and approximately 7% of the seed weight in seeds from heterozygous canola plants. When a threonine deaminase was expressed in addition to bktB, phaB and phaC, a copolyester of 3-hydroxybutyrate and 3-hydroxyvalerate was produced in both Arabidopsis and Brassica.     

Pathogenicity of bacterial isolates to Cyclocephala signaticollis (Coleoptera: Scarabaeidae)

We describe the isolation and identification of pathogenic bacteria obtained from haemolymph of Cyclocephala signaticollis larvae. Two pathogenic bacteria, a Bacillus thuringiensis and an Arthrobacter sp. caused 90–100% mortality to C. signaticollis in 4 days after hemocoel injection, suggesting they might be useful as biological control agents.     

The familial adenomatous polyposis region exhibits many different haplotypes

In the present study, we used five different polymorphic markers to construct the haplotype at the adenomatous polyposis coli (APC) locus in families with familial adenomatous polyposis (FAP) and in the normal Italian population. Non-ambiguous haplotypes were reconstructed from 246 normal chromosomes and 65 FAP chromosomes. In the control population, the four polymorphisms intragenic to APC gave rise to 16 haplotypes, the most common of which (II and XV) accounted for over 50% of all chromosomes. In FAP patients, 13 haplotypes were found but their distribution was not statistically different from normal subjects. Eighty complete chromosomal haplotypes (many fewer than the theoretical maximum of 208) for the five polymorphic sites assayed were observed in the control population, 35 being found in the FAP patients. We compared the distribution of these haplotypes within the two groups; no statistically significant differences between normal and FAP chromosomes were found. The elevated heterogeneity of FAP chromosomes was clearly confirmed by the observation that 19 patients who carried one or other of the two most common APC mutations (nt 3183 and nt 3927) showed 18 different haplotypes. On the basis of these results, we were not able to identify a founder FAP chromosome. Various mechanisms are presented to explain this observation. Received: 5 November 1997 / Accepted: 3 February 1998