930 research outputs found
Evidence for CO2-rich fluids in rocks from the type charnockite area near Pallavaram, Tamil Nadu
Fluid inclusion and mineral chemistry data was presented for samples from the type charnockite area near Pallavaram (Tamil Nadu, India). The results indicate the presence of a dense CO2 fluid phase, but the data cannot distinguish between influx of this fluid from elsewhere or localized migration of CO2-rich fluids associated with dehydration melting
Liposome- or LDL-administered Zn (II)-phthalocyanine as a photodynamic agent for tumours. I. Pharmacokinetic properties and phototherapeutic efficiency.
The pharmacokinetics of Zn-phthalocyanine (Zn-Pc) in mice bearing a transplanted MS-2 fibrosarcoma has been studied using dipalmitoyl-phosphatidylcholine (DPPC) liposomes and low density lipoproteins (LDL) as drug delivery systems. LDL induce a higher Zn-Pc uptake by the tumour and improve the selectivity of tumour targeting as compared to DPPC liposomes. Experimental photodynamic therapy (PDT) of the MS-2 fibrosarcoma has been performed using liposome-delivered Zn-Pc and the efficiency of tumour necrosis has been measured following four different irradiation protocols. We found that Zn-Pc doses as low as 0.07-0.35 mg kg-1 are sufficient for inducing an efficient tumour response that is linearly dependent on the injected dose. The amount of Zn-Pc in the tumour decreases very slowly as a function of time, hence PDT gives satisfactory results even if performed at relatively long time intervals after administration
Controlled targeting of different subcellular sites by porphyrins in tumour-bearing mice.
Unilamellar liposomes of dipalmitoyl-phosphatidylcholine can incorporate various porphyrins in either the phospholipid bilayer or the internal aqueous compartment depending on the water-/lipo-solubility of the drug. Intraperitoneal injection of the liposome-bound porphyrins to mice bearing a MS-2 fibrosarcoma results in remarkably more efficient tumour targeting than that obtained by administration of the same porphyrins dissolved in homogeneous aqueous solution. Moreover, also water-insoluble porphyrins can be transported to the tumour via liposomes. Fractionation of liver and neoplastic cells indicates that the subcellular distribution of liposome-delivered porphyrins is also dependent on their solubility properties: thus, relatively polar porphyrins, such as tetra(4-sulfonatophenyl)porphine and uroporphyrin, are mainly recovered from the soluble fraction, whereas hydrophobic porphyrins, such as haematoporphyrin or porphyrin esters, preferentially partition in the cytoplasmic membrane. As a consequence, different subcellular sites can be targeted by porphyrins and possibly photodamaged through a suitable choice of the drug-carrier system
Cartilage Oligomeric Matrix Protein (COMP): A Biomarker of Arthritis
Arthritis is a chronic disease with a significant impact on the population. It damages the cartilage, synovium, and bone of the joints causing pain, impairment, and disability in patients. Current methods for diagnosis of and monitoring the disease are only able to detect clinical manifestations of arthritis late in the process. However, with the recent onset of successful treatments for rheumatoid arthritis and osteoarthritis, it becomes important to identify prognostic factors that can predict the evolution of arthritis. This is especially critical in the early phases of disease so that these treatments can be started as soon as possible to slow down progression of the disease. A valuable approach to monitor arthritis would be by measuring biological markers of cartilage degradation and repair to reflect variations in joint remodeling. One such potential biological marker of arthritis is cartilage oligomeric matrix protein (COMP). In various studies, COMP has shown promise as a diagnostic and prognostic indicator and as a marker of the disease severity and the effect of treatment. This review highlights the progress in the utilization of COMP as a biomarker of arthritis
Low doses of cisplatin or gemcitabine plus Photofrin/photodynamic therapy: Disjointed cell cycle phase-related activity accounts for synergistic outcome in metastatic non-small cell lung cancer cells (H1299).
We compared the effects of monotherapy (photodynamic therapy or chemotherapy) versus combination therapy (photodynamic therapy plus a specific drug) on the non-small cell lung cancer cell line H1299. Our aim was to evaluate whether the additive/synergistic effects of combination treatment were such that the cytostatic dose could be reduced without affecting treatment efficacy. Photodynamic therapy was done by irradiating Photofrin-preloaded H1299 p53/p16-null cells with a halogen lamp equipped with a bandpass filter. The cytotoxic drugs used were cis-diammine-dichloroplatinum [II] (CDDP or cisplatin) and 2',2'-difluoro-2'-deoxycytidine (gemcitabine). Various treatment combinations yielded therapeutic effects (trypan blue dye exclusion test) ranging from additive to clearly synergistic, the most effective being a combination of photodynamic therapy and CDDP. To gain insight into the cellular response mechanisms underlying favorable outcomes, we analyzed the H1299 cell cycle profiles and the expression patterns of several key proteins after monotherapy. In our conditions, we found that photodynamic therapy with Photofrin targeted G0-G1 cells, thereby causing cells to accumulate in S phase. In contrast, low-dose CDDP killed cells in S phase, thereby causing an accumulation of G0-G1 cells (and increased p21 expression). Like photodynamic therapy, low-dose gemcitabine targeted G0-G1 cells, which caused a massive accumulation of cells in S phase (and increased cyclin A expression). Although we observed therapeutic reinforcement with both drugs and photodynamic therapy, reinforcement was more pronounced when the drug (CDDP) and photodynamic therapy exert disjointed phase-related cytotoxic activity. Thus, if photodynamic therapy is appropriately tuned, the dose of the cytostatic drug can be reduced without compromising the therapeutic response
From Synthesis to Utilization: The Ins and Outs of Mitochondrial Heme
Heme is a ubiquitous and essential iron containing metallo-organic cofactor required for virtually all aerobic life. Heme synthesis is initiated and completed in mitochondria, followed by certain covalent modifications and/or its delivery to apo-hemoproteins residing throughout the cell. While the biochemical aspects of heme biosynthetic reactions are well understood, the trafficking of newly synthesized heme—a highly reactive and inherently toxic compound—and its subsequent delivery to target proteins remain far from clear. In this review, we summarize current knowledge about heme biosynthesis and trafficking within and outside of the mitochondria
Extra-Mitochondrial CU/Zn Superoxide Dismutase (SOD1) Is Dispensable for Protection Against Oxidative Stress but Mediates Peroxide Signaling in Saccharomyces Cerevisiae
Cu/Zn Superoxide Dismutase (Sod1) is a highly conserved and abundant metalloenzyme that catalyzes thedisproportionation of superoxide radicals into hydrogen peroxide and molecular oxygen. As a consequence, Sod1serves dual roles in oxidative stress protection and redox signaling by both scavenging cytotoxic superoxideradicals and producing hydrogen peroxide that can be used to oxidize and regulate the activity of downstreamtargets. However, the relative contributions of Sod1 to protection against oxidative stress and redox signaling arepoorly understood. Using the model unicellular eukaryote, Baker\u27s yeast, we found that only a small fraction ofthe total Sod1 pool is required for protection against superoxide toxicity and that this pool is localized to themitochondrial intermembrane space. On the contrary, wefind that much larger amounts of extra-mitochondrialSod1 are critical for peroxide-mediated redox signaling. Altogether, our results force the re-evaluation of thephysiological role of bulk Sod1 in redox biology; namely, we propose that the vast majority of Sod1 in yeast isutilized for peroxide-mediated signaling rather than superoxide scavenging
Assessment of heavy metal threat in agaricus bisporus mushrooms cultivated from water hyacinth weed of Kolleru lake, Andhra pradesh- India
ABSTRACT Verification of heavy metal threat owing to utilization of water hyacinth of Kolleru Lake as mushroom growth substrate instead of paddy straw has formed the objective of this investigation. Using ICP-MS, ten trace elements in Agaricus bisporus were determined. The mean values of trace elements in the mushrooms cultivated from the water hyacinth shoots were 16.72±0.6, 7.448±0.368, 46.86±3.52, 0.146±0.6, 0.756±0.054, 16.18±2.96, 1596±81.6, 1.434±0.074, 0.564±0.056 and 0.64±0.16 mg/kg for Mn, Cu, Zn, Cd, Pb, Cr, Fe, Ni, Co and arsenic respectively. The mushrooms cultivated from the paddy straw formed the controls for comparison purpose. Observed statistically no significant differences of mean values of metals between the experimental and control groups and found the heavy metals consents within the prescribed limits of safety standards. Hence, recommended the utilization of water hyacinth weed as a substitute to paddy straw for A. bisporus mushroom cultivation
- …