Insulin-dependent diabetes mellitus (IDDM) is a disease with an autoimmune aetiology. The inbred non-obese diabetic (NOD) mouse strain provides a good animal model of the human disease and genetic analysis suggests that, as in man, at least one of the several genes controlling the development of IDDM is linked to the major histocompatibility complex. The NOD mouse does not express I-E owing to a deletion in the promoter region of the I-E alpha-chain gene, and the sequence of NOD I-A beta-chain in the first external domain is unique with His 56 and Ser 57 replacing Pro and Asp, respectively, at these positions. There has been considerable interest in the role amino acid 57 might have in conferring susceptibility to autoimmune diseases, including IDDM. The presence of a charged residue (such as Asp) at this position might affect the conformation of the peptide binding groove. But it could be assumed that Pro 56 gives rise to a different conformation of I-A beta-chain than does His 56. We therefore constructed transgenic NOD mice in which the transgene encoded a modified A beta nod with Pro 56, and studied its effect on the development of IDDM in this mouse strain. Previous studies have suggested that NOD mice expressing I-E as a result of the introduction of an I-E alpha-chain (E alpha) transgene are protected from the development of insulitis and hence IDDM. To explore further the protective effect of this molecule we constructed a second class of transgenic NOD mouse carrying an E alpha d transgene. Both transgenes protected the mice from IDDM, but this was not associated with a complete deletion of any T cells expressing commonly used T-cell receptor V beta genes.

Cosmid vectors have been developed which carry selective markers for growth in bacteria (beta lactamase gene) and animal cells (the Herpes Simplex virus thymidine kinase gene, the transposon Tn-5 aminoglycosyl 3' phosphotransferase gene and the E. coli guanine phosphoribosyltransferase gene). The design of the cosmids allows the exchange of the eukaryotic markers in recombinant cosmids. Human and mouse cosmid libraries containing DNA inserts of about 40kb have been generated by an improved method. Several clones from the human beta-globin locus were isolated. These cosmids transform mouse L cells at high efficiency in both circular and linear form. The newly introduced genes are expressed accurately in L cells.

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The blood-brain barrier prevents the entry of many therapeutic agents into the brain. Various nanocarriers have been developed to help agents to cross this barrier, but they all have limitations, with regard to tissue-selectivity and their ability to cross the endothelium. This study investigated the potential for 4 nm coated gold nanoparticles to act as selective carriers across human brain endothelium and subsequently to enter astrocytes. The transfer rate of glucose-coated gold nanoparticles across primary human brain endothelium was at least three times faster than across non-brain endothelia. Movement of these nanoparticles occurred across the apical and basal plasma membranes via the cytosol with relatively little vesicular or paracellular migration; antibiotics that interfere with vesicular transport did not block migration. The transfer rate was also dependent on the surface coating of the nanoparticle and incubation temperature. Using a novel 3-dimensional co-culture system, which includes primary human astrocytes and a brain endothelial cell line hCMEC/D3, we demonstrated that the glucose-coated nanoparticles traverse the endothelium, move through the extracellular matrix and localize in astrocytes. The movement of the nanoparticles through the matrix was >10 µm/hour and they appeared in the nuclei of the astrocytes in considerable numbers. These nanoparticles have the correct properties for efficient and selective carriers of therapeutic agents across the blood-brain barrier.

The emergence of multi-drug resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) causes a major threat to public health due to its limited therapeutic options. There is an urgent need for the development of new effective antimicrobial agents and alternative strategies that are effective against resistant bacteria. The parallel legalization of cannabis and its products has fueled research into its many therapeutic avenues in many countries around the world. This study aimed at the development of a reliable method for the extraction, purification, characterization, and quantification of cannabidiolic acid (CBDA) and its decarboxylated form cannabidiol (CBD) present in the fiber type Cannabis sativa L. The two compounds were extracted by ethanol, purified on a C18 sep-pack column, and the extracts were analyzed by high performance liquid chromatography coupled with ultraviolet (UV)–vis and ESI-MS (electrospray ionization mass spectrometry) detection. The antimicrobial effect of CBDA and CBD was also evaluated. CBD displayed a substantial inhibitory effect on Gram-positive bacteria with minimal inhibitory concentrations ranging from 1 to 2 µg/mL. Time kill analysis and minimal bactericidal concentration revealed potential bactericidal activity of CBDA and CBD. While cannabinoids showed a significant antimicrobial effect on the Gram-positive S. aureus and Staphylococcus epidermidis, no activity was noticed on Gram-negative Escherichia coli and Pseudomonas aeruginosa. CBDA presented a two-fold lower antimicrobial activity than its decarboxylated form, suggesting that the antimicrobial pharmacophore of the analyzed cannabinoids falls in the ability for permeabilizing the bacterial cell membrane and acting as a detergent-like agent. A synergy test performed on MRSA with CBD and a range of antibiotics did not indicate a synergetic effect, but noteworthy no antagonist influence either. CBD and CBDA manifested low hemolytic activity on human red blood cells. Likewise, the safety of CBD toward human keratinocyte cells presents no toxicity at a concentration of up to seven-fold higher than the antibacterial minimal inhibitory concentration. Similarly, both CBD and CBDA are well tolerated by mammals, including humans, and conserve a safe value limits for blood-contacting drug development. Overall, CBD exhibited a strong antimicrobial effect against Gram-positive strains and could serve as an alternative drug for tackling MRSA.