Promotion of sustainable capture fisheries and aquaculture in Asian reservoirs and lakes

A collaborative international project funded by the European Union's INCO-DC programme is undertaking limnological, fish biological, environmental and socio-economic research in five tropical lakes and reservoirs in Sri Lanka, Thailand and the Philippines over the period 1998–2001. The aim is to determine their trophic structure and their capacity to sustain both their existing fisheries and present and future aquaculture. In some cases, these activities could potentially be expanded for the benefit of rural communities and of the local market within the bounds of social and environmental sustainability. This paper describes the concepts and methods involved in this innovative multidisciplinary project which aims to integrate limnological, fisheries and socio-economic issues in a comparative approach involving Asian and European research teams.Deceased.     

Is <Emphasis Type="Italic">Testudo werneri</Emphasis> a distinct species?

Sequence variation of a 1066 bp long mtDNA fragment (cytochrome b gene, adjacent part of tRNA-Thr gene) of four known-locality samples of Testudo kleinmanni (Tripolitania, Libya) and of four samples of T. werneri (Negev, Israel) is compared with additional five sequences of pet trade tortoises allegedly representing T. kleinmanni. Four haplotypes, differing in one to four mutation steps occur. The most common haplotype was shared by all known-locality samples of T. kleinmanni and three T. werneri. Sequence variation within each nominal species and in the pooled sample of T. kleinmanni, T. werneri and pet trade tortoises is the lowest known for any Testudo species. We conclude there is no support for the validity of T. werneri Perälä, 2001.     

Effects of fasting on the control of fatty-acid synthesis in hepatoma 7777 and host liver. Role of long-chain fatty acyl-CoA,, the mitochondrial citrate transporter and pyruvate dehydrogenase activity.

The effects of fasting on the rate of fatty acid synthesis, the properties of the mitochondrial citrate transporter and on pyruvate dehydrogenase activity were investigated in "poorly-differentiated" tmorris hepatoma 7777 and in host liver preparations. The properties of the citrate transporter from hepatoma mitochondria were similar to those of host liver mitochondria, with the exception that the Km for the liver mitochondrial citrate transporter was 248 plus or minus 20 mu M while that in hepatoma mitochondria was less than 75 mu M. The acid-insoluble CoA content was 180 plus or minus 20 pmol/mg protein in the hepatoma and remained essentially unchanged in the fasted state, while the acid-insoluble CoA levels in livers from fed rats was 720 plus or minus 80 pmol/mg protein and were increased to 1050 plus or minus 50 pmol/mg protein during fasting. After a 36-h fast, the rate of lipogenesis and the percentage of pyruvate dehydrogenase present in the active form were each decreased by approximately 80% in host liver preparations. In contrast, the rate of lipogenesis by hepatoma slices did not decrease during fasting, and essentially all pyruvate dehydrogenase present was in the active form of hepatomas obtained from either fed or fasted animals. Implications concerning the identification of possible regulatory sites in the control of lipogenesis were discussed in relation to the above observations.     

Biochemical and tissue print analyses of hydroxyproline-rich glycoproteins in cell walls of sporophytic maize tissues

In an effort to understand the role of hydroxyproline-rich glycoproteins (HRGPs) in plant cell wall structure, we studied the distribution and physical properties of PC-1-like proteins (PC-1 being the major pericarp HRGP) throughout sporophytic tissues of two maize (Zea mays L.) varieties. We determined total amounts of hydroxyproline, an indicator of HRGPs, and did tissue print and Western blot analysis. We found hydroxyproline in cell walls of stems, leaves, roots, tassels, and silks. We also observed reactivity of anti-PC-1 monoclonal antibodies with anatomical prints of these tissues on nitrocellulose paper. Stem nodes and silks contained the most hydroxyproline and exhibited the strongest reaction with the antibody. PC-1 was localized in vascular bundles and the epidermis of stem tissue. However, localization to a specific cell type in the silk could not be determined at the resolution of the tissue print. The stem node protein had the same electrophoretic mobility as the pericarp protein as determined on Western blots prepared from cationic neutral gels. Protein extracts from silk tissues of both varieties studied contained one protein of the same size/charge as that found in pericarp, as well as some minor variant bands. The data presented here document that cell wall proteins are present in many tissues of the maize plant, although they are primarily in cell types contributing to support.     

Carbonic anhydrase inhibitors. Inhibition of the β-class enzymes from the fungal pathogens Candida albicans and Cryptococcus neoformans with aliphatic and aromatic carboxylates

The inhibition of the β-carbonic anhydrases (CAs, EC 4.2.1.1) from the pathogenic fungi Cryptococcus neoformans (Can2) and Candida albicans (Nce103) with carboxylates such as the C1–C5 aliphatic carboxylates, oxalate, malonate, maleate, malate, pyruvate, lactate, citrate and some benzoates has been investigated. The best Can2 inhibitors were acetate and maleate (K_Is of 7.3–8.7 μM), whereas formate, acetate, valerate, oxalate, maleate, citrate and 2,3,5,6-tetrafluorobenzoate showed less effective inhibition, with K_Is in the range of 42.8–88.6 μM. Propionate, butyrate, malonate, l-malate, pyruvate, l-lactate and benzoate, were weak Can2 inhibitors, with inhibition constants in the range of 225–1267 μM. Nce103 was more susceptible to inhibition with carboxylates compared to Can2, with the best inhibitors (maleate, benzoate, butyrate and malonate) showing K_Is in the range of 8.6–26.9 μM. l-Malate and pyruvate together with valerate were the less efficient Nce103 inhibitors (K_Is of 87.7–94.0 μM), while the remaining carboxylates showed a compact behavior of efficient inhibitors (K_Is in the range of 35.1–61.6 μM). Notably the inhibition profiles of the two fungal β-CAs was very different from that of the ubiquitous host enzyme hCA II (belonging to the α-CA family), with maleate showing selectivity ratios of 113.6 and 115 for Can2 and Nce103, respectively, over hCA II inhibition. Therefore, maleate is a promising starting lead molecule for the development of better, low nanomolar, selective β-CA inhibitors.     

PREPARATION OF PLASMA MEMBRANE FROM ISOLATED NEURONS

A bulk fraction enriched with respect to neuronal cell bodies was used as starting material for the isolation of neuronal plasma membrane The cells were gently homogenized in isotonic sucrose and a crude membrane containing fraction sedimented at 3000 g. Subsequently, the membrane fraction was purified on a discontinuous sucrose density gradient between 35% and 25 5% sucrose (w/w). Enzymatic analyses showed a 4–5-fold enrichment in plasma membrane markers, and a 10–15% contamination of mitochondrial and microsomal material. Electron micrographs of the membrane fraction confirmed the enzymatic data Fragmented membranes were found, mainly in vesicular form No ribosomes, but a few mitochondria and some multilamellar membranes were seen     

Genetic and functional analyses of SHANK2 mutations suggest a multiple hit model of autism spectrum disorders

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. Here, following the discovery of two de novo SHANK2 deletions by the Autism Genome Project, we identified a novel 421 kb de novo SHANK2 deletion in a patient with autism. We then sequenced SHANK2 in 455 patients with ASD and 431 controls and integrated these results with those reported by Berkel et al. 2010 (n = 396 patients and n = 659 controls). We observed a significant enrichment of variants affecting conserved amino acids in 29 of 851 (3.4%) patients and in 16 of 1,090 (1.5%) controls (P = 0.004, OR = 2.37, 95% CI = 1.23–4.70). In neuronal cell cultures, the variants identified in patients were associated with a reduced synaptic density at dendrites compared to the variants only detected in controls (P = 0.0013). Interestingly, the three patients with de novo SHANK2 deletions also carried inherited CNVs at 15q11–q13 previously associated with neuropsychiatric disorders. In two cases, the nicotinic receptor CHRNA7 was duplicated and in one case the synaptic translation repressor CYFIP1 was deleted. These results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the “multiple hit model” for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD.     

Transduction and Plasmid Deoxyribonucleic Acid Analysis in a Multiply Antibiotic-Resistant Strain of Staphylococcus epidermidis

A genetic analysis of a multiply antibiotic-resistant strain of Staphylococcus epidermidis was performed. Experiments designed to show reversion of organisms to antibiotic susceptibility, as well as studies of the influence of ultraviolet irradiation of phage on the transduction frequencies of the resistance markers, indicated that determinants of chloramphenicol (cml), tetracycline (tet), and neomycin (neo) resistance are present on separate plasmids, but the streptomycin marker is chromosomal. In 2 to 6% of tetracycline-resistant transductants, co-transduction of cml was also observed. By using CsCl-dye density gradients followed by neutral sucrose gradients, the plasmids carrying cml, tet, and neo could be isolated and their molecular weights could be determined. The tetracycline plasmid is shown to be incompatible with one of the cryptic plasmids of a recipient strain.