Uptake Kinetics and Subcellular Compartmentalization Explain Lethal but Not Sublethal Effects of Cadmium in Two Closely Related Amphipod Species.

Eulimnogammarus cyaneus and Eulimnogammarus verrucosus, closely related amphipod species endemic to Lake Baikal, differ with respect to body size (10- to 50-fold lower fresh weights of E. cyaneus) and cellular stress response (CSR) capacity, potentially causing species-related differences in uptake, internal sequestration, and toxic sensitivity to waterborne cadmium (Cd). We found that, compared to E. verrucosus, Cd uptake rates, related to a given exposure concentration, were higher, and lethal concentrations (50%; LC50) were 2.3-fold lower in E. cyaneus (4 weeks exposure; 6 °C). Upon exposures to species-specific subacutely toxic Cd concentrations (nominal LC1; E. cyaneus: 18 nM (2.0 µg L-1); E. verrucosus: 115 nM (12.9 µg L-1); 4 weeks exposure; 6 °C), Cd amounts in metal sensitive tissue fractions (MSF), in relation to fresh weight, were similar in both species (E. cyaneus: 0.25 ± 0.06 µg g-1; E. verrucosus: 0.26 ± 0.07 µg g-1), whereas relative Cd amounts in the biologically detoxified heat stable protein fraction were 35% higher in E. cyaneus. Despite different potencies in detoxifying Cd, body size appears to mainly explain species-related differences in Cd uptake and sensitivities. When exposed to Cd at LC1 over 4 weeks, only E. verrucosus continuously showed 15-36% reduced oxygen consumption rates indicating metabolic depression and pointing to particular sensitivity of E. verrucosus to persisting low-level toxicant pressure.

The biogeographic differentiation of algal microbiomes in the upper ocean from pole to pole.

Eukaryotic phytoplankton are responsible for at least 20% of annual global carbon fixation. Their diversity and activity are shaped by interactions with prokaryotes as part of complex microbiomes. Although differences in their local species diversity have been estimated, we still have a limited understanding of environmental conditions responsible for compositional differences between local species communities on a large scale from pole to pole. Here, we show, based on pole-to-pole phytoplankton metatranscriptomes and microbial rDNA sequencing, that environmental differences between polar and non-polar upper oceans most strongly impact the large-scale spatial pattern of biodiversity and gene activity in algal microbiomes. The geographic differentiation of co-occurring microbes in algal microbiomes can be well explained by the latitudinal temperature gradient and associated break points in their beta diversity, with an average breakpoint at 14 °C ± 4.3, separating cold and warm upper oceans. As global warming impacts upper ocean temperatures, we project that break points of beta diversity move markedly pole-wards. Hence, abrupt regime shifts in algal microbiomes could be caused by anthropogenic climate change.

Autoimmunotherapy of type II diabetes with soluble low-molecular-mass antigens: a case report.

AIMS: To study whether autoimmunization of patients suffering from non-insulin-dependent Type II diabetes with soluble low-molecular-mass antigens (LMA) isolated from their serum will activate the immune system and improve clinical status. MATERIALS AND METHODS: From March 1998 to July 2000, the patient was treated, under observation, with LMA isolated from that same patient. Doses for injections varied between 2 and 5 mg of LMA. Injections were performed at weekly or monthly intervals. Biochemical studies were performed before injections and 1 to 2 weeks after them. The following biochemical parameters were determined in the blood: levels of glucose, insulin-competitive auto-antibodies (ICAA), a-glutamine acid decarboxylase (GAD), total concentration of LMA and of the 66 kDa and 51 kDa proteins as main representatives of the LMA isolated. RESULTS: The patient suffered from high blood glucose levels (BGL), ICAA, GAD, hemoglobin Alc and, especially, of LMA and their proteins. Shortarm immunotherapy did not improve the parameters studied. However, a regular monthly injection of LMA at a dose of 3.5 to 4 mg significantly decreased BGL and reduced the concentrations of LMA and their proteins. The whole clinical status of the patient improved and became more stable. CONCLUSION: We suggest that vaccination of a diabetic patient with LMA activates the host immune system, thereby preventing progress of the disease.