Molecular detection of Leishmania (Sauroleishmania) tarentolae in human blood and Leishmania (Leishmania) infantum in Sergentomyia minuta: unexpected host-parasite contacts

The detection of atypical Kinetoplastida in vertebrate hosts and vectors might suggest unexpected host-parasite contacts. Aside to major vectors of Leishmania (Leishmania) infantum in Italy (e.g. Phlebotomus perniciosus and Phlebotomus perfiliewi), the sand fly fauna also includes Sergentomyia minuta, herpetophilic and proven vector of Leishmania (Sauroleishmania) tarentolae, in which records of blood meal on mammals and detection of L. infantum DNA are increasing. This study was conducted in Central Italy aiming to molecularly detect potential atypical Leishmania host-vector contacts. Detection of Leishmania spp. DNA was performed by polymerase chain reaction (SSU rRNA, ITS1 targets) on field-collected sand fly females (N = 344), blood samples from humans (N = 185) and dogs (N = 125). Blood meal identification was also performed on engorged sand flies. Leishmania spp. DNA was found in 13.1% sand flies, 3.7% humans and 14.4% dogs. Sequence analysis identified L. infantum in S. minuta (4.4%), P. perniciosus (9.1%), humans (2.2%) and dogs (14.4%). Leishmania tarentolae was detected in S. minuta (12.6%), P. perfiliewi (6.6%) and human (1.6%) samples. Of 28 S. minuta examined for blood meal, 3.6 and 21.4% scored positive for human and lizard DNA, respectively. These results indicate the importance of one-health approach to explore new potential routes of transmission of leishmaniasis involving S. minuta.     

Enzymatic degradation and quantitative lectin labeling for characterizing glycoconjugates which act as lectin acceptors in cat submandibular gland

Sites of binding of eight different lectins (LTA, UEA I, WGA, SBA, DBA, CON A, PNA, RCA I) to cat submandibular gland were studied after exposure of tissue sections to sialidase, alpha-fucosidase, beta-galactosidase, alpha-mannosidase, beta-N-acetylglucosaminidase. All lectins were affected by enzymatic predigestion and the labeling of individual lectins was highly dependent upon the glycosidase used to pretreat the sections. Glycoconjugates of demilunar, acinar and ductal cells exhibited a different composition of terminal sequences. For example, fucose proved to form the disaccharide fucose-galactose in demilunar and acinar cells, whereas it was present with the sequence fucose-N-acetyl-D-glucosamine in striated duct cells. Sialic acid participated both to the terminal sequence sialic acid-galactose and sialic acid-N-acetyl-D-galactosamine either in demilunar or in ductal cells. Lectin labeling combined with glycosidase digestion was also helpful in verifying the influence of neighbouring oligosaccharides on the affinity of lectins for the respective sugars.     

From Innovation to Diversification: A Simple Competitive Model

Few attempts have been proposed in order to describe the statistical features and historical evolution of the export bipartite matrix countries/products. An important standpoint is the introduction of a products network, namely a hierarchical forest of products that models the formation and the evolution of commodities. In the present article, we propose a simple dynamical model where countries compete with each other to acquire the ability to produce and export new products. Countries will have two possibilities to expand their export: innovating, i.e. introducing new goods, namely new nodes in the product networks, or copying the productive process of others, i.e. occupying a node already present in the same network. In this way, the topology of the products network and the country-product matrix evolve simultaneously, driven by the countries push toward innovation.     

Aerobiological monitoring of the 'Sistine Chapel': airborne bacteria and microfungi trends

The present paper reports the results of a bacteriological and mycological monitoring carried out on the airborne microflora of the Sistine Chapel. The general aim of the study was to evaluate the impact of the flow of visitors, as well seasonal effects, on the qualitative and quantitative variations of microorganisms. Two sampling campaigns were carried out in May and November 1997. A Surface Air System (SAS) sampler (active system) and a sedimentation based sampler (passive system), supported by an original plinth, were used. Temperature, humidity and carbon dioxide were detected. VITEK SYSTEMS jr. for Staphylococcus spp. and microscopic observation for microfungi were the identification methods. In spite of the conditioning and filtration air system, initial results with both samplers, show a positive correlation between the airborne microorganisms and presence and number of visitors. The SAS samples showed higher microbial load, for both bacteria and fungi, than the passive ones, but the epidemiological meaning of the differently collected data varies. The increase during visiting hours of human Staphylococcus spp. is stronger than the airborne bacterial load increase. The microfungi most frequently isolated were Cladosporium spp. and Penicillium spp. These preliminary data underline the significance of the survey for the protection of such a precious environment, and encourage the Authors to continue the ongoing monitoring. This revised version was published online in June 2006 with corrections to the Cover Date.     

Preliminary study on oncogene product immunohistochemistry (c-erbB-2, c-myc, ras p21, EGFR) in breast pathology.

The expression of oncogene products related to cell growth (c-erbB-2, c-myc, ras p21, EGFR) was investigated in benign (15 cases) and malignant breast lesions (20 cases) by means of immunohistochemistry using the avidin-biotin-peroxidase technique with polyclonal and monoclonal antibodies. The aim of this study was to evaluate the relationship between the staining positivity and various morphological and biological features, such as tumour type, grading, hormone receptor status and cell kinetic parameters. In benign breast lesions, as expected, the kinetic parameters were low, both for Ki-67 and LI. All the specimens showed a diploid condition (the DI being equal to 1) and we found a limited degree of immunoreactivity for all the growth factors and oncogene products. In breast cancer we studied the distribution of immunohistochemical positivity for EGFR, c-erbB-2, c-myc, ras p21 and Ki-67, which was related to age, nodal status, ER and PgR receptor status, LI, DI and histopathological grading. A significant positive correlation was found both between ras p21 expression and nodal status and ER-ICA positivity. We observed a strong correlation between LI and Ki-67 and an inverse relation between Ki-67 and ER expression. These findings suggest the importance of studying the relationship between prognostic factors which may provide preoperative prediction in the biological behaviour of breast cancer, not only on biopsy specimens, but also on fine needle aspirates.     

Identification of a novel nuclear protein synthesized in growth-arrested human hepatoblastoma HepG2 cells.

DNA synthesis of human hepatoblastoma HepG2 cells is reversibly inhibited by butyrate. When butyrate is removed from the culture medium, cells re-enter the cell cycle, synthesizing DNA with a time lag of about 12 h. HepG2 cells, growth-inhibited for 30 h with butyrate, synthesize and accumulate a nuclear protein, called D. Protein D synthesis is inhibited in cells which, released from the butyrate block, have resumed DNA synthesis as well as in growing cells never exposed to butyrate. Protein D has been purified from growth-arrested cells and partially sequenced. The amino acid sequences of five internal trypsin peptides indicate that protein D is a novel nuclear protein.     

EVOLUTIONARY IMPLICATIONS OF LEAF RESIN POCKET PATTERNS IN THE TROPICAL TREE HYMENAEA (CAESALPINIOIDEAE: LEGUMINOSAE)

ABSTRACT: Measurement of the size (volume), distribution, and density of resin pockets are compared in margin and center areas of leaves in 11 species (including six varieties of two widespread species) of Hymenaea. Resin composition and yield (mg/g leaf tissue) were analyzed by gas-liquid chromatography. Resin pocket patterns in certain species are highly distinctive; also a relationship seems to exist between patterns of closely related species, with variation having occurred in species or populations of widespread species which have radiated into different kinds of habitats. Thus these patterns may provide useful taxonomic characters, but we suggest that some of the patterns (and thus composition and yield of resin of different portions of the leaf) have evolved under selective pressures of herbivorous insects.