The optimal process of self-sampling in fisheries: lessons learned in the Netherlands.

At-sea sampling of commercial fishery catches by observers is a relatively expensive exercise. The fact that an observer has to stay on-board for the duration of the trip results in clustered samples and effectively small sample sizes, whereas the aim is to make inferences regarding several trips from an entire fleet. From this perspective, sampling by fishermen themselves (self-sampling) is an attractive alternative, because a larger number of trips can be sampled at lower cost. Self-sampling should not be used too casually, however, as there are often issues of data-acceptance related to it. This article shows that these issues are not easily dealt with in a statistical manner. Improvements might be made if self-sampling is understood as a form of cooperative research. Cooperative research has a number of dilemmas and benefits associated with it. This article suggests that if the guidelines for cooperative research are taken into account, the benefits are more likely to materialize. Secondly, acknowledging the dilemmas, and consciously dealing with them might lay the basis to trust-building, which is an essential element in the acceptance of data derived from self-sampling programmes.

Surface hydrophobicity is increased in the ileum and proximal colon of cystic fibrosis mice.

Patients with cystic fibrosis (CF) have abnormal concentrations and composition of electrolytes and macromolecules in gastrointestinal secretions. Such alterations could change intestinal surface properties, such as surface hydrophobicity, and may influence the adhesion of macromolecules, bacteria, or microbial toxins to the intestinal surface. The objective of this study was to compare the surface hydrophobicity of the gastrointestinal tract in wild type and CF mice. We used axisymmetric drop shape analysis-contact diameter to determine surface hydrophobicity by measuring contact angles of sessile water droplets placed onto epithelial surfaces. In wild type mice, there were no differences in contact angles between the duodenum, upper jejunum, lower jejunum, and ileum. The contact angle of the gastric mucosa was lower than the rest of the gastrointestinal tract. Contact angles of the proximal colon and distal colon were both higher than that of the gastric mucosa and those of the small intestinal sections. In CF mice, contact angles along the gastrointestinal tract followed the same pattern as in wild type mice. However, contact angles in the ileum and proximal colon of CF mice were greater than those from wild type mice. This study of the murine intestine showed regional differences in surface hydrophobicity comparable to those observed in other mammalian species. In addition, we showed that the ileum and proximal colon of CF mice were more hydrophobic than the corresponding segments in wild type mice. These observations are of potential clinical relevance because patients with CF exhibit clinical manifestations of gastrointestinal disease primarily in the ileum and proximal colon.

Screening of hundred Rwandese medicinal plants for antimicrobial and antiviral properties.

A series of 100 Rwandese medicinal plants (267 plant extracts), used by traditional healers to treat infections, were screened for antibacterial, antifungal and antiviral properties. The results of the testing showed that 45% were active against Staphylococcus aureus, 2% against Escherichia coli, 16% against Pseudomonas aeruginosa, 7% against Candida albicans, 80% against Microsporum canis and 60% against Trichophyton mentagrophytes. Not less than 27% of the plant species exhibited prominent antiviral properties against one or more test viruses, more specifically 12% against poliomyelitis, 16% against coxsackie, 3% against Semliki forest, 2% against measles and 8% against herpes simplex virus.

Plant antiviral agents, VI. Isolation of antiviral phenolic glucosides from Populus cultivar Beaupre by droplet counter-current chromatography.

Bioassay-guided isolation of the 80% EtOH extract of the leaves of Populus cultivar Beaupré by means of dccc afforded four known phenolic glucosides. Salicin and salireposide were shown to be, at least partially, responsible for the antiviral activity of the extract against poliomyelitis and Semliki forest viruses.

Structure and chemotherapeutical activity of a polyisoprenylated benzophenone from the stem bark of Garcinia huillensis.

The stem bark of Garcinia huillensis grown in Zaïre and used in central-African traditional medicine has been subjected to a bioassay-guided fractionation. The chemotherapeutically active petroleum ether extract afforded fatty acids, aliphatic alcohols, triterpenes and a polyisoprenylated benzophenone, which was identified as garcinol, also named camboginol. This compound has been shown to exhibit chemotherapeutical activity gram-positive and gram-negative cocci, mycobacteria and fungi. On the other hand garcinol has been found to be inactive against gram-negative enteric bacilli, yeasts and viruses.

The poliovirus-induced shut-off of cellular protein synthesis persists in the presence of 3-methylquercetin, a flavonoid which blocks viral protein and RNA synthesis.

In poliovirus-infected cells, the viral protein and RNA synthesis were severely reduced, provided 3-methylquercetin was present between 1 and 2 h post-infection. Under these conditions, the virally induced host shut-off remained in effect. On the other hand, in uninfected HeLa cells, protein and RNA synthesis was inhibited only slightly by 3-methylquercetin. The inhibition of poliovirus cytopathogenicity in Vero cells by 3-methylquercetin exhibited a similar time dependence.

Plant Antiviral Agents; VI.1 3-Methoxyflavones as Potent Inhibitors of Viral-Induced Block of Cell Synthesis.

An investigation of the constituents responsible for the pronounced antiviral activity observed for extracts of EUPHORBIA GRANTII Oliv. stems has afforded four related 3-methoxyflavones exhibiting remarkable activities against picornaviruses and vesicular stomatitis virus. All compounds were found to be derivatives of 3-methylquercetin. The concentration of 3-methylquercetin (3-MQ) and 3,3'-dimethyl-quercetin (3,3'-DMQ) inhibiting 90 % of polio type 1 and coxsackie B4 viruses in tissue culture was about 0.01 microg/ml, whereas the 50 % cytotoxic concentration was 40 microg/ml. When administered intraperitoneally, 3-MQ protected mice from viremia and lethal infections from coxsac kie B4 virus at a daily dose of 20 mg/kg for a period of nine days. Biochemical studies on the mechanism of action of 3-MQ or 3,3'-DMQ on poliovirus replication suggested that these 3-methoxyflavones are able to protect the host cells from a viral induced shutdown of the cellular protein synthesis. Preliminary structure activity relationship studies have shown the 3-methoxyfunction of the flavones to be essential for the observed antiviral effects.