10 research outputs found
Characterization of the murine macrophage response to infection with virulent and avirulent Burkholderia species
Gold complexes as prospective metal-based anticancer drugs
Medical and therapeutic value of gold has
been recognized thousands of years ago, but its rational
use in medicine has not begun until the early 1920s.
Cisplatin is one of the first metal-containing compounds
with anti-cancer activity discovered in the 1960s.
Despite the fact that cisplatin treatment is efficient for
several types of solid tumors, its effectiveness is limited
by toxic side effects and tumor resistance that often leads
to the occurrence of secondary malignancies. Since
gold(III) is isoelectronic with platinum(II) and
tetracoordinate gold(III) complexes have the same
square-planar geometries as cisplatin, the anticancer
activity of gold(III) compounds has been investigated.
Previous studies suggested that, in contrast to cisplatin,
gold complexes target proteins but not DNA. Recently,
we have investigated gold(III) dithiocarbamates for their
anticancer activity and showed that their primary target
is the proteasome. Treatment of human breast tumorbearing
nude mice with a gold(III) dithiocarbamate
complex resulted in significant inhibition of tumor
growth, associated with proteasome inhibition and
massive apoptosis induction in vivo. Better
understanding of physiological processing of gold
compounds will provide a rational basis for their further
development into novel anticancer drugs
Ni(II), Cu(II), and Zn(II) Diethyldithiocarbamate Complexes Show Various Activities Against the Proteasome in Breast Cancer Cells
Impact of the poly(propylene oxide)-b-poly(dimethylsiloxane)-b-poly(propylene oxide) macrodiols on the surface related properties of polyurethane copolymers
Segmented thermoplastic polyurethane copolymers (PURs) were synthesized using 4,4'-methylenediphenyl diisocyanate and 1,4-butanediol as the hard segment and alpha,omega-dihydroxy-poly(propylene oxide)-b-poly(dimethylsiloxane)-b-poly(propylene oxide) (PPO-PDMS) as the soft segment. The content of incorporated soft segments in PURs varied in the range from 40 to 90 wt.%. The structure, molecular weights and crystallinity of obtained copolymers were monitored by FTIR, H-1- and 2D-NMR spectroscopy, and GPC and DSC analysis, respectively. Surface free energy analysis indicates the presence of hydrophobic (siloxane) groups on the surface, giving highly hydrophobic nature to the obtained PURs films. Water absorption measurements showed that the increase of the hydrophobic PPO-PDMS segment content led to the decrease of percentage of absorbed water in copolymers. SEM and AFM analysis revealed that copolymers with lower content of PPO-PDMS segments have higher microphase separation between segments. The results obtained in this work indicate that synthesized PURs based on PPO-PDMS demonstrated proper surface and morphological properties with a great potential for variety of applications such as hydrophobic coatings in biomedicine
A Novel Anticancer Gold(III) Dithiocarbamate Compound Inhibits the Activity of a Purified 20S Proteasome and 26S Proteasome in Human Breast Cancer Cell Cultures and Xenografts
Tea polyphenols, their biological effects and potential molecular targets
Tea is the most popular beverage in the
world, second only to water. Tea contains an infusion of
the leaves from the Camellia sinensis plant rich in
polyphenolic compounds known as catechins, the most
abundant of which is (-)-EGCG. Although tea has been
consumed for centuries, it has only recently been studied
extensively as a health-promoting beverage that may act
to prevent a number of chronic diseases and cancers. The
results of several investigations indicate that green tea
consumption may be of modest benefit in reducing the
plasma concentration of cholesterol and preventing
atherosclerosis. Additionally, the cancer-preventive
effects of green tea are widely supported by results from
epidemiological, cell culture, animal and clinical studies.
In vitro cell culture studies show that tea polyphenols
potently induce apoptotic cell death and cell cycle arrest
in tumor cells but not in their normal cell counterparts.
Green tea polyphenols were shown to affect several
biological pathways, including growth factor-mediated
pathway, the mitogen-activated protein (MAP) kinasedependent
pathway, and ubiquitin/proteasome
degradation pathways. Various animal studies have
revealed that treatment with green tea inhibits tumor
incidence and multiplicity in different organ sites such as
skin, lung, liver, stomach, mammary gland and colon.
Recently, phase I and II clinical trials have been
conducted to explore the anticancer effects of green tea
in humans. A major challenge of cancer prevention is to
integrate new molecular findings into clinical practice.
Therefore, identification of more molecular targets and biomarkers for tea polyphenols is essential for
improving the design of green tea trials and will greatly
assist in a better understanding of the mechanisms
underlying its anti-cancer activity