The utility of saliva for the assessment of anti-pneumococcal antibodies: investigation of saliva as a marker of antibody status in serum

Context: Salivary antibodies may act as non-invasive marker of systemic immunity enabling assessment of vaccination and protection against bacterial infections.

Objective: To assess if levels of anti-pneumococcal (Pn) antibodies in saliva reflect concentrations in serum and determine whether saliva can accurately identify protective concentrations in serum.

Methods: IgG, IgA and IgM antibody levels in paired saliva and serum samples were measured against 12 Pn polysaccharide antigens in 72 healthy adults.

Results: Antibody levels in saliva correlated positively with serum across immunoglobulin classes, most strongly for IgA. Individuals who had protective antibody levels in serum demonstrated significantly higher IgG and IgA salivary antibody concentrations/secretion rates. Salivary IgG and IgA Pn antibodies were able to distinguish between those with/without protective levels in serum for the majority of serotypes. Salivary IgM antibodies were not able to differentiate protective status. Median IgG and IgA Pn salivary parameters were able to identify individuals who had protective levels in serum on ≥8/12 serotypes with moderate accuracy: median IgA secretion rates provided the best sensitivity (73%) and specificity (71%).

Conclusions: These findings suggest that IgG and IgA Pn specific antibodies in saliva may be useful surrogate markers of antibody status in serum.     

Asaia sp., an Unusual Spoilage Organism of Fruit-Flavored Bottled Water

A gram-negative bacillus was isolated from a batch of fruit-flavored bottled water, which had spoiled as a result of bacterial overgrowth (>10⁶ CFU/ml). The spoilage organism was extremely difficult to identify phenotypically and was poorly identified as Pasturella sp. (78.7% identification profile) employing the API 20NE identification scheme, which gave the profile 5040000. Molecular identification through PCR amplification of a partial region of the 16S rRNA gene followed by direct automated sequencing of the PCR amplicon allowed identification of the organism. Due to the sequence identity (100%) between the spoilage organism and a reference strain in GenBank, the spoilage isolate was considered to be an Asaia sp., a recently described genus and member of the acetic acid bacteria. This is the first report of Asaia sp. causing spoilage of a foodstuff and highlights the benefits of molecular identification techniques based on 16S rRNA gene sequences in the identification of unusual spoilage organisms.     

Hyperlactataemia in Phenformin-treated Diabetics

Raised fasting blood lactate levels were observed in diabetic patients on phenformin in therapeutic dosage. After an intravenous glucose load this effect was exaggerated and the lactate/pyruvate ratio increased. Withdrawal of the drug led to normal blood lactate levels and a fall in the lactate/pyruvate ratio.     

The roles of geological history and colonization abilities in genetic differentiation between mammalian populations in the Philippine archipelago

Aim To test hypotheses that: (1) late Pleistocene low sea‐level shorelines (rather than current shorelines) define patterns of genetic variation among mammals on oceanic Philippine islands; (2) species‐specific ecological attributes, especially forest fidelity and vagility, determine the extent to which common genetic patterns are exhibited among a set of species; (3) populations show reduced within‐population variation on small, isolated oceanic islands; (4) populations tend to be most highly differentiated on small, isolated islands; and (5) to assess the extent to which patterns of genetic differentiation among multiple species are determined by interactions of ecological traits and geological/geographic conditions. Location The Philippine Islands, a large group of oceanic islands in Southeast (SE) Asia with unusually high levels of endemism among mammals. Methods Starch‐gel electrophoresis of protein allozymes of six species of small fruit bats (Chiroptera, Pteropodidae) and one rodent (Rodentia, Muridae). Results Genetic distances between populations within all species are not correlated with distances between present‐day shorelines, but are positively correlated with distances between shorelines during the last Pleistocene period of low sea level; relatively little intraspecific variation was found within these ‘Pleistocene islands’. Island area and isolation of oceanic populations have only slight effects on standing genetic variation within populations, but populations on some isolated islands have heightened levels of genetic differentiation, and reduced levels of gene flow, relative to other islands. Species associated with disturbed habitat (all of which fly readily across open habitats) show more genetic variation within populations than species associated with primary rain forest (all of which avoid flying out from beneath forest canopy). Species associated with disturbed habitats, which tend to be widely distributed in SE Asia, also show higher rates of gene flow and less differentiation between populations than species associated with rain forest, which tend to be Philippine endemic species. One rain forest bat has levels of gene flow and heterozygosity similar to the forest‐living rodent in our study. Main conclusions The maximum limits of Philippine islands that were reached during Pleistocene periods of low sea level define areas of relative genetic homogeneity, whereas even narrow sea channels between adjacent but permanently isolated oceanic islands are associated with most genetic variation within the species. Moreover, the distance between ‘Pleistocene islands’ is correlated with the extent of genetic distances within species. The structure of genetic variation is strongly influenced by the ecology of the species, predominantly as a result of their varying levels of vagility and ability to tolerate open (non‐forested) habitat. Readily available information on ecology (habitat association and vagility) and geological circumstances (presence or absence of Pleistocene land‐bridges between islands, and distance between oceanic islands during periods of low sea level) are combined to produce a simple predictive model of likely patterns of genetic differentiation (and hence speciation) among these mammals, and probably among other organisms, in oceanic archipelagos.     

Peripheral sweat gland function is improved with humid heat acclimation

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The purpose of this study was to determine if humid heat acclimation improves thermoregulatory function at the level of the eccrine sweat gland.     

A multivalent DNA aptamer specific for the B-cell receptor on human lymphoma and leukemia

Long-term survival still eludes most patients with leukemia and non-Hodgkin's lymphoma. No approved therapies target the hallmark of the B cell, its mIgM, also known as the B-cell receptor (BCR). Aptamers are small oligonucleotides that can specifically bind to a wide range of target molecules and offer some advantages over antibodies as therapeutic agents. Here, we report the rational engineering of aptamer TD05 into multimeric forms reactive with the BCR that may be useful in biomedical applications. Systematic truncation of TD05 coupled with modification with locked nucleic acids (LNA) increased conformational stability and nuclease resistance. Trimeric and tetrameric versions with optimized polyethyleneglycol (PEG) linker lengths exhibited high avidity at physiological temperatures both in vitro and in vivo. Competition and protease studies showed that the multimeric, optimized aptamer bound to membrane-associated human mIgM, but not with soluble IgM in plasma, allowing the possibility of targeting leukemias and lymphomas in vivo. The B-cell specificity of the multivalent aptamer was confirmed on lymphoma cell lines and fresh clinical leukemia samples. The chemically engineered aptamers, with significantly improved kinetic and biochemical features, unique specificity and desirable pharmacological properties, may be useful in biomedical applications.     

Lake enrichment and the status of Windermere charr, Salvelinus alpinus (L.)

All English populations of Arctic charr, Salvelinus alpinus (L.), are found in the Lake District (northwest England). There are at least four races of charr in Windermere, the largest lake in England; the North and South basins of the lake each contain two distinct races that spawn in autumn and spring respectively. The spring spawners in both basins probably represent less than 15% of the total population in the lake.
Changes in the population density of charr in the lake are described briefly and examined in relation to the trophic status of the lake. Other factors that could possibly affect the charr population are reviewed, especially the influence of climate change.     

Light, temperature and nitrogen as interacting factors affecting diel vertical migrations of dinoflagellates in culture

Diel vertical migrations of the marine dinoflagellates Gonyaulaxpolyedra Stein and Ceratium furca (Ehr.) Clap, et Lachm. werefollowed in a laboratory tube (2.02 m x 0.25 m) under a 12:12hlight:dark cycle. The effects of temperature stratification,two levels of surface irradiance and nitrogen depletion on patternsof vertical migrations were examined. At temperatures between22–26°C with small temperature gradients, both speciesmigrated at a rate of 0.7 –1.0 m h^–1. Steeper thermoclines(ca. 0.8°C 0.1 m^–1) with temperatures below ca. 20°Ccaused a marked decrease in swimming speed which resulted inaccumulations of cells in these thermocline regions. Under conditionsof nutrient sufficiency both algae migrated into the surfacelayers at irradiance values of over 1000 µE m^–2s^–1. Increasing nitrogen depletion caused the downwardmigration of both algae to commence progressively earlier inthe day and before the end of the light period. The earlierdownward migrations enabled a more complete descent throughthe thermocline. Nitrogen depleted cells of Gonyaulax continuedto undertake vertical migrations but avoided high irradiancesthus forming subsurface maxima at irradiance levels close to150 µE m^–2 s^–1. Ceratium cells which exhaustedboth inorganic nitrogen and phosphorus ceased to migrate accompaniedby a large change in cellular fluorescence.