Tropical terrestrial invertebrates—Where to from here?

There are over one million described invertebrate species on Earth, the majority of which are likely to inhabit the highly biodiverse rain forests around the equator. These are some of the most vulnerable ecosystems on Earth due to the pressures of deforestation and climate change with many of their inhabitants at risk of extinction. Invertebrates play a major role in ecosystem functioning from decomposition and nutrient cycling to herbivory and pollination; however, while our understanding of these roles is improving, we are far from being able to predict the consequences of further deforestation, climate change, and biodiversity loss due to the lack of comparative data and the high proportion of species which remain to be discovered. As we move into an era of increased pressure on old-growth habitats and biodiversity, it is imperative that we understand how changes to invertebrate communities, and the extinction of species, affect ecosystems. Innovative and comprehensive methods that approach these issues are needed. Here, we highlight priorities for future tropical terrestrial invertebrate research such as the efficiency of sustainable land management, exploration of innovative methods for better understanding of invertebrate ecology and behavior, and quantifying the role of invertebrates in ecosystem functioning.     

Occurrence of poly-3-hydroxybutyrate inAzospirillum sp.

Azospirillum strains isolated from the roots and rhizosphere of some plants growing in West Bengal were subjected to qualitative and quantitative evaluation for poly-3-hydroxybutyrate (PHB) production. Out of the total 49 isolates, 13 (26%) were confirmed as PHB producers according to staining and chemical assay methods. The majority of these strains belonged toAzospirillum brasilense butA. amazonense andA. lipoferum were also present. When grown in the presence of NH₄Cl in the medium, the PHB content of the strains ranged from 1 to 14% of cell dry mass. The identity of the PHB extracted fromAzospirillum strain 24P-N-72 was confirmed by the characteristic UV and IR absorption peaks at 235 nm and 1730 cm⁻¹, respectively.     

The range of action of the mother and the avoidance of big novel objects in long-tailed macaques

Most surrogate-reared long-tailed macaques persistently avoid a big novel object, whereas most mother-reared subjects approach it. A striking difference between these attachment figures is that the mothers moved about with their infants, whereas the surrogates were fixed to the wall In this experiment, we aimed to find out whether mobility of the attachment figure plays a part in the development of an infant’s responses to big novel objects. We studied the effects of mobility of the attachment figure by restraining mothers in their range of action. We confined mothers of the experimental group in a small part of the home cage. Their infants could leave the cage in which their mothers were restrained. Infants that were growing up with unrestrained mothers made up the control group. At two different ages all infants encountered a big novel object. We used two different objects. We found that the range of action of the mother did not significantly affect the responses of infants to big novel objects. As in the previous studies, most of the mother-reared monkeys approached the objects. The age at which an infant was first exposed to an object did not significantly affect its behavior toward it. Further, the two different objects evoked the same reactions.     

Two different β-lactamase genes are present in Streptomycees cacaoi

Two beta-lactamase genes called blaL and blaU have been cloned independently in Liège and in Ume?, from Streptomyces cacaoi. Genes blaL and blaU were found to differ largely in their nucleotide sequences, although the encoded proteins both belonged to the class A of beta-lactamases (active-site serine penicillinases). DNA-hybridization and polymerase chain reaction assays have now demonstrated that both blaL and blaU genes were present in the S. cacaoi strains used in Liège and in Ume?.     

Neurotoxicity,drugs of abuse,and the CuZn-superoxide dismutase transgenic mice

Administration of methamphetamine (METH) to animals causes loss of DA terminals in the brain. The manner by which METH causes these changes in neurotoxicity is not known. We have tested the effects of this drug in copper/zinc (CuZn)-superoxide dismutase transgenic (SOD Tg) mice, which express the human CuZnSOD gene. In nontransgenic (non-Tg) mice, acute METH administration causes significant decreases in DA and dihydroxyphenylacetic acid (DOPAC) in the striata of non-Tg mice. In contrast, there were no significant decreases in striatal DA in the SOD Tg mice. The effects of METH on DOPAC were also attenuated in SOD Tg mice. Chronic METH administration caused decreases in striatal DA and DOPAC in the non-Tg mice, but not in the SOD-Tg mice. Similar studies were carried out with 1-methyl-1,2,3,6-tetrahydropyridine (MPTP), which also causes striatal DA and DOPAC depletion. As in the case of METH, MPTP causes marked depletion of DA and DOPAC in the non-Tg mice, but not in the SOD Tg mice. These results suggest that the mechanisms of toxicity of both METH and MPTP involve superoxide radical formation.     

Clinically Relevant Growth Conditions Alter Acinetobacter baumannii Antibiotic Susceptibility and Promote Identification of Novel Antibacterial Agents

Biological processes that govern bacterial proliferation and survival in the host-environment(s) are likely to be vastly different from those that are required for viability in nutrient-rich laboratory media. Consequently, growth-based antimicrobial screens performed in conditions modeling aspects of bacterial disease states have the potential to identify new classes of antimicrobials that would be missed by screens performed in conventional laboratory media. Accordingly, we performed screens of the Selleck library of 853 FDA approved drugs for agents that exhibit antimicrobial activity toward the Gram-negative bacterial pathogen Acinetobacter baumannii during growth in human serum, lung surfactant, and/or the organism in the biofilm state and compared those results to that of conventional laboratory medium. Results revealed that a total of 90 compounds representing 73 antibiotics and 17 agents that were developed for alternative therapeutic indications displayed antimicrobial properties toward the test strain in at least one screening condition. Of the active library antibiotics only four agents, rifampin, rifaximin, ciprofloxacin and tetracycline, exhibited antimicrobial activity toward the organism during all screening conditions, whereas the remainder were inactive in ≥ 1 condition; 56 antibiotics were inactive during serum growth, 25 and 38 were inactive toward lung surfactant grown and biofilm-associated cells, respectively, suggesting that subsets of antibiotics may outperform others in differing infection settings. Moreover, 9 antibiotics that are predominantly used for the treatment Gram-positive pathogens and 10 non-antibiotics lacked detectable antimicrobial activity toward A. baumannii grown in conventional medium but were active during ≥ 1 alternative growth condition(s). Such agents may represent promising anti-Acinetobacter agents that would have likely been overlooked by antimicrobial whole cell screening assays performed in traditional laboratory screening media.     

Multifunctional liposomes for nasal delivery of the anti-Alzheimer drug tacrine hydrochloride

The purpose of this study was the development of multifunctional liposomes for nasal administration of tacrine hydrochloride. Liposomes were prepared using traditional excipients (cholesterol and phosphatidylcholine), partly enriched with α-tocopherol and/or Omega3 fatty acids. This approach was chosen in order to obtain at the same time two positive results: an enhanced drug permeation through nasal mucosa and a concomitant neuroprotective effect. Several liposome formulations were prepared using the Reverse Phase Evaporation technique followed by membrane filter extrusion. In particular, liposome capacity to enhance drug permeation was evaluated by means of membrane permeation and cellular uptake studies. Furthermore, liposome effect on neuronal viability and intracellular ROS production was evaluated as well as their cytoprotective effect against oxidative stress. All liposome formulations showed a mean diameter in the range of 175?nm to 219?nm with polydispersity index lower than 0.22, a lightly negative zeta potential and excellent encapsulation efficiency. Moreover, along with good mucoadhesive properties, multifunctional liposomes showed a markedly increase in tacrine permeability, which can be related to liposome fusion with cellular membrane, a hypothesis, which was also supported by cellular uptake studies. Finally, the addition of α-tocopherol without Omega3 fatty acids, was found to increase the neuroprotective activity and antioxidant properties of liposomes.