J. W. M. Chan

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Nanotechnology is the understanding and control of matter generally in the 1-100 nm dimension range. The application of nanotechnology to medicine, known as nanomedicine, concerns the use of precisely engineered materials at this length scale to develop novel therapeutic and diagnostic modalities. Nanomaterials have unique physicochemical properties, such(More)
We have investigated the activity of 60 bisphosphonates against the replication of Toxoplasma gondii in vitro and of three of the most active compounds, in vivo. The two most active compounds found were n-alkyl bisphosphonates containing long (n = 9 or 10) hydrocarbon chains, not the nitrogen-containing species used in bone resorption therapy. The target of(More)
Hexokinase is the first enzyme involved in glycolysis in most organisms, including the etiological agents of Chagas disease (Trypanosoma cruzi) and African sleeping sickness (Trypanosoma brucei). The T. cruzi enzyme is unusual since, unlike the human enzyme, it is inhibited by inorganic diphosphate (PPi). Here, we show that non-hydrolyzable analogues of(More)
Trypanosoma brucei, the causative agent of African trypanosomiasis, contains a soluble, vacuolar pyrophosphatase, TbVSP1, not present in humans, which is essential for the growth of bloodstream forms in their mammalian host. Here, we report the inhibition of a recombinant TbVSP1 expressed in Escherichia coli by a panel of 81 bisphosphonates. The IC50 values(More)
The effects of moisture content from 17 to 159% MC and temperatures from −71°C to +58°C on resonance-based acoustic velocity and dynamic modulus of elasticity (DMOE) were investigated using 36 boards of radiata pine sapwood. Acoustic velocity decreased with increasing moisture content and temperature, although effects differed noticeably below and above(More)
Several fluorescent macrocycles based on 1,3-butadiyne-bridged dibenz[a,j]anthracene subunits have been synthesized via a multistep route. The synthetic strategy involved the initial construction of a functionalized dibenz[a,j]anthracene building block, subsequent installation of free alkyne groups on one side of the polycyclic aromatic framework, and a(More)
Lignin samples isolated from Miscanthus giganteus using organosolv processes were treated with vanadium catalysts that were previously developed in our group. We demonstrate that the catalyst with high β-O-4′ bond-cleaving activity in dimeric lignin models was also effective in depolymerizing actual lignin. Molecular weight-lowering was evidenced by gel(More)
gammadelta T cells are the first line of defense against many infectious organisms and are also involved in tumor cell surveillance and killing. They are stimulated by a broad range of small, phosphorus-containing antigens (phosphoantigens) as well as by the bisphosphonates commonly used in bone resorption therapy, such as pamidronate and risedronate. Here,(More)
The effects of a series of 102 bisphosphonates on the inhibition of growth of Entamoeba histolytica and Plasmodium falciparum in vitro have been determined, and selected compounds were further investigated for their in vivo activity. Forty-seven compounds tested were active (IC(50) < 200 microM) versus E. histolytica growth in vitro. The most active(More)
γδ T cells are the first line of defense against many infectious organisms and are also involved in tumor cell surveillance and killing. They are stimulated by a broad range of small, phosphorus-containing antigens (phosphoantigens) as well as by the bisphosphonates commonly used in bone resorption therapy, such as pamidronate and risedronate. Here, we(More)