the paper contains the first report on the biology of snail-killing flies (sciomyzidae) in khuzestan. it is based on field and laboratory studies conducted during november 1971 and april 1973, as well as field observations in may 1972, at the dezful medical research station. additional biological information obtained during studies is given for pherbellia fuscipes (macaquart), p.grisescens (mei...

Antigen-specific killing ability of effector CD8+ T cells is critical for protective immunity against infection. Here, we describe in vivo cytotoxic T cell assay to examine effector function of antigen-specific CD8+ T cells. Mice infected with Listeria monocytogenes (L. monocytogenes) expressing chicken ovalbumin as a model antigen mount ovalbumin-specific CD8+ T cell responses. Effector CD8+ T...

Tumor cell killing utilizing hematoporphyrin derivative (HPD) phototherapy was studied in a murine tumor model to assess the relative importance of intratumor temperature in causing the tumoricidal effect. Temperature measurements and tumor killing without HPD strongly suggest that HPD phototherapy as reported previously by other workers has at least partially a hyperthermic effect. Also, it is...

We have constructed a synthetic ecosystem consisting of two Escherichia coli populations, which communicate bi-directionally through quorum sensing and regulate each other's gene expression and survival via engineered gene circuits. Our synthetic ecosystem resembles canonical predator-prey systems in terms of logic and dynamics. The predator cells kill the prey by inducing expression of a kille...

Thymidine incorporation by HEp-2 cells was reduced 10-fold by 2.5 mM hydroxyurea (HU). The DNA in lysates from untreated cells sedimented through alkaline sucrose gradients as an aggregate plus a smaller component which could be chased into the aggregate. Only small DNA (ca. 47 S) was synthesized in nuclei when cells were incubated with HU. HU inhibition was reversible up-to 24 hr. Removal of i...

A terbium complex has been designed that may be used to sensitise formation of singlet oxygen (phi(em) 12%), allowing the creation of a ratiometric sensory system for pO(2) (versus the insensitive Eu analogue) and the definition of a reactive probe that can be used to cause local damage to cells loaded with the complex and exposed to laser excitation.

Cytotoxic T lymphocytes (CTLs) are important immune effectors against intra-cellular pathogens. These cells search for infected cells and kill them. Recently developed experimental methods in combination with mathematical models allow for the quantification of the efficacy of CTL killing in vivo and, hence, for the estimation of parameters that characterize the effect of CTL killing on the targ...

aquatic plants have been used prevalently in china since 3000 years ago due to having various chemical compounds for diseases prevention and cure. dunaliella salina is one of the micro algae in marine ecosystems containing beta-carotene, retinal, apocarotenoides, ketones, aldehydes and epoxides which enable it to absorb free radicals and produce singlet oxygen.  in many studies, the anti-cancer...