High resolution,label‐free photoacoustic imaging of live chicken embryo developing in bioengineered eggshell

Chicken embryos have been proven to be an attractive vertebrate model for biomedical research. They have helped in making significant contributions for advancements in various fields like developmental biology, cancer research and cardiovascular studies. However, a non‐invasive, label‐free method of imaging live chicken embryo at high resolution still needs to be developed and optimized. In this work, we have shown the potential of photoacoustic tomography (PAT) for imaging live chicken embryos cultured in bioengineered eggshells. Laser pulses at wavelengths of 532 and 740 nm were used for attaining cross‐sectional images of chicken embryos at different developmental stages. Cross‐sections along different depths were imaged to gain knowledge of the relative depth of different vessels and organs. Due to high optical absorption of vasculature and embryonic eye, images with good optical contrast could be acquired using this method. We have thus reported a label‐free method of performing cross‐sectional imaging of chicken embryos at high resolution demonstrating the capacity of PAT as a promising tool for avian embryo imaging.     

Correlating the charge transfer efficiency of metallic sulfa-isatins to design efficient NLO materials with better drug designs

BioMetals - The present study presents synthesis, characterization and first principle studies on metal chelates, (1–12), of sulfonamide-isatin reacted ligands (S1–S3). All the products...     

Interferon-γ down-regulates membrane adenylate cyclase activity of a murine macrophage-like cell line (P388D1)

Effects of recombinant murine interferon-γ (rIFN-γ) on the membrane adenylate cyclase of a murine macrophage cell line (P388D₁) were investigated in order to explore the nature of a signal transmitted by IFN-γ receptor. Following the incubation of P388D₁ cells with 40 U/ml of rIFN-γ, the intracellular level of cAMP gradually increased about twofold over the control level within 60 min, and then began to gradually decline to about half the control level by 24 h incubation. The initial rise in cAMP level appeared to be due to the modest activation of adenylate cyclase and not due to the inhibition of cAMP-phosphodiesterase. Later decrease of intracellular cAMP may be due to quantitative down-regulation of the adenylate cyclase system. The basal enzymatic activity of the membrane prepared from P388D₁ cells exposed to IFN-γ for 24 h was found to be reduced to about 20% of that of the control membrane. However, the quality of the adenylate cyclase system appeared unchanged, because the relative degree of the response of the down-regulated membrane adenylate cyclase to prostaglandin PGE₂, NaF, guanylimidodiphosphate (GppNHp), cholera toxin (CT), or forskolin was found to remain unchanged. This quantitative down-regulation of adenylate cyclase must be due to the action of rIFN-γ, since the prior treatment of rIFN-γ with either acid (pH 2) or monoclonal anti-IFN-γ antibody inhibited the ability of IFN-γ to induce the down-regulation. The rIFN-γ-induced down-regulation is a reversible process, since the adenylate cyclase activity of the membrane was found to be restored when the rIFN-γ-exposed cells were cultured for 72 h in the absence of rIFN-γ. In addition, the 48 h-incubation of P388D₁ cells with rIFN-β or IFN-α was found not to significantly affect the membrane adenylate cyclase system.