32720111
Assessment of some tumorigenic risks associated with fresh and used cutting oil.
35457752
Nordihydroguaiaretic acid, an inhibitor of lipoxygenase, also inhibits cytochrome P-450-mediated monooxygenase activity in rat epidermal and hepatic microsomes.
Nordihydroguaiaretic acid (NDGA), a plant lignan and phenolic antioxidant, is a known lipoxygenase inhibitor. In this study, we investigated the effect of NDGA on rat epidermal and hepatic monooxygenase activity and its interaction with rat hepatic microsomal cytochrome P-450. The addition of NDGA to epidermal microsomes prepared from control and 3-methylcholanthrene (3-MC)-pretreated rats and hepatic microsomal preparations from control, 3-MC-pretreated, and phenobarbital (PB)-pretreated rats resulted in a concentration-dependent inhibition of aryl hydrocarbon hydroxylase (AHH) and 7-ethoxyresorufin O-deethylase (ERD) activities. The 50% inhibitory dose for NDGA ranged from 4.1 x 10(-5) to 13.1 x 10(-5) M for AHH and ERD activities in these microsomal preparations. The addition of NDGA to hepatic microsomes prepared from PB-pretreated rats resulted in spectral changes characterized by absorbance maxima at 380 nm and minima at 414 nm, typical of type I binding difference spectra. It also showed time- and concentration-dependent inhibition of the binding of carbon monoxide to dithionite or NADPH-reduced cytochrome P-450. We speculate that perhaps hydroxyl groups present in NDGA play an important role in inhibiting the monooxygenase activity and suggest that NDGA may have potential as an antimutagen and/or anticarcinogen. Furthermore, caution must be exercised in elucidating the role of lipoxygenase in metabolic pathways based solely on the criterion of inhibition by NDGA.
37464296
Introduction to Special Issue on Molecular Basis for Cancer Prevention with Bioactive Food Components in Nutrition and Cancer--an International Journal.
The advance of technology and understanding of the process of cancer development suggests that the reported lesser incidence and death due to cancer in countries other than the Western and European countries might also be due to under- diagnosed and under-represented cases. Further, increases in life span as well as ignorance about the disease puts populations in South and South East Asian countries at higher risk to develop cancer. With the increasing rate of cancer incidence every year in non -Western countries, cancer is estimated to become the deadliest disease in coming decades. Conventional chemo- and radio-therapies during the past three decades have not been able to contain the disease, and also have serious side effects. Many natural agents, especially small molecules from plants are non-toxic, easily available and may have anticancer potential. Thus, screening phytochemicals as anticancer agents could be a better approach in cancer prevention and treatment. This chemoprevention approach may have translational significance for prevention and treatment of cancer. 
 
Therefore to emphasize the potential role of phytochemicals in cancer prevention and therapy, it was our privilege to host the International Symposium on Recent Advances in Cancer Research: Therapeutics to Chemoprevention, at Central University of Gujarat (CUG), Gandhinagar. The conference was co-organized by the University of Colorado Denver, USA; University of Pittsburgh, USA; University of Oklahoma, USA, during 8–9 February, 2012. Modern biological strategies, specifically the latest developments for the targeted prevention and treatment of cancer via dietary, natural and synthetic agents were discussed in detail. The symposium also emphasized the translational aspect of cancer chemoprevention strategies for various cancers. 
 
The symposium deliberations include the ideas for combinatorial chemoprevention by phytochemicals as a promising approach for cancer control and emerging trends for the use of herbal radio-modulators to sensitize the cancer cells for apoptotic cell death. Many bioactive phytochemicals such as silibinin, benzyl isothiocyanate, anthocyanidins, nexrutine, tocopherol, etc. were discussed for their in vivo efficacy in animal tumor models, associated mechanisms and translational potential. Targeting tumor microenvironment with small molecules was found promising and having translational potential for prostate and breast cancer chemoprevention. 
 
The novel work and ideas presented at the symposium were helpful in guiding the research orientation of scientists, especially the young researchers who will be benefitted at all levels of their career development. Since chemoprevention of cancer is becoming an attractive approach for controlling cancer, we felt that the deliberations of this symposium should reach to the wider section of the researchers. Therefore, it was planned to bring out a special issue on Molecular Basis for Cancer Prevention with Bioactive Food Components in Nutrition and Cancer – An International Journal. We appreciate the researchers for contributing their novel work and ideas to this special issue. We are grateful to the Editor of Nutrition and Cancer – An International Journal, for his initiative to bring out this special issue on this relevant topic. We believe that this volume will be enlightening for the researchers working in the area of cancer chemoprevention.
46117096
ras protein p21 processing enzyme farnesyltransferase in chemical carcinogen-induced murine skin tumors.
Farnesylation of ras protein p21 is crucial for the protein's membrane localization, which is essential for its cell-transforming activity, which in turn is thought to be critical for the ultimate induction of cancer. The cytosolic enzyme farnesyltransferase plays a major role in posttranslational modification of p21, but the level of farnesyltransferase activity in mammalian tumors and its relationship to the processing of cytosolic p21 that leads to tumorigenesis are unknown. We report here that farnesyltransferase activity was significantly higher in chemical carcinogen-induced benign skin papillomas in SENCAR mice than in the epidermises of control animals. The enzyme is primarily epidermal in origin, and kinetic studies with cytosol from epidermis and papillomas showed that the reaction was linear with respect to time, substrate concentration, and protein content. Skin papillomas showed significantly elevated levels of both cytosolic and membrane-bound Ha-ras p21, whereas far lesser cytosolic and almost negligible amounts of membrane-bound p21 were present in the epidermis of control mice. There was a positive correlation between increased enzyme activity in papilloma cytosol and the processing of overexpressed cytosolic Ha-ras p21 for its localization to membrane.
6837472
Apoptosis is an early event during phthalocyanine photodynamic therapy-induced ablation of chemically induced squamous papillomas in mouse skin.
Photodynamic therapy (PDT) is a promising new modality to treat malignant neoplasms including superficial skin cancers. In our search for an ideal photosensitizer for PDT, Pc 4, a silicon phthalocyanine, has shown promising results both in in vitro assays and in implanted tumors. In this study we assessed the efficacy of Pc 4 PDT in the ablation of murine skin tumors; and the evidence for apoptosis during tumor ablation was also obtained. The Pc 4 was administered through tail vein injection to SENCAR mice bearing chemically induced squamous papillomas, and 24 h later the lesions were illuminated with an argon ion-pumped dye laser tuned at 675 nm for a total light dose of 135 J/cm2. Within 72-96 h, almost complete tumor shrinkage occurred; no tumor regrowth was observed up to 90 days post-PDT. As evident by nucleosome-size DNA fragmentation, appearance of apoptotic bodies in hematoxylin and eosin staining and direct immunoperoxidase detection of digoxigenin-labeled genomic DNA in sections, apoptosis was clearly evident 6 h post-PDT at which time tumor shrinkage was less than 30%. The apoptotic bodies, as evident by the condensation of chromatin material around the periphery of the nucleus and increased vacuolization of the cytoplasm, were also observed in electron microscopic studies of the tumor tissues following Pc 4 PDT. The extent of apoptosis was greater at 15 h than at 6 and 10 h post-PDT. Taken together, our results clearly show that Pc 4 may be an effective photosensitizer for PDT of nonmelanoma skin cancer, and that apoptosis is an early event during this process.
5785486
Identification of the site of photocross-linking formed in the absence of magnesium nucleotide from SH2 (Cys-697) in myosin subfragment 1 labeled with 4'-maleimidylbenzophenone.
The site of photocross-linking between Cys-697 (SH2), prelabeled with 4'-[14C]maleimidylbenzophenone, and the 50-kDa segment of myosin S1 on irradiation in the absence of nucleotide has been determined by isolation of the 20-50-kDa adduct and subsequent tryptic proteolysis. Isolation and partial sequencing of the radioactively labeled peptide indicate that the site of cross-linking is Arg-239. This result indicates that, in the absence of nucleotide, Arg-239 resides at about 1.0 nm from SH2 and, on the basis of the recent work of Sutoh and Hiratsuka (Sutoh, K. and Hiratsuka T. (1988) Biochemistry 27, 2964-2969) places Arg-239 at no more than 1.45 nm from either Lys-184 or Lys-189 of the nucleotide-binding "glycine-rich" loop prior to the binding of nucleotide.
10671348
Structural analysis of botulinum neurotoxin serotype F light chain: implications on substrate binding and inhibitor design.
The seven serologically distinct Clostridium botulinum neurotoxins (BoNTs A-G) are zinc endopeptidases which block the neurotransmitter release by cleaving one of the three proteins of the soluble N-ethylmaleimide-sensitive-factor attachment protein receptor complex (SNARE complex) essential for the fusion of vesicles containing neurotransmitters with target membranes. These metallopeptidases exhibit unique specificity for the substrates and peptide bonds they cleave. Development of countermeasures and therapeutics for BoNTs is a priority because of their extreme toxicity and potential misuse as biowarfare agents. Though they share sequence homology and structural similarity, the structural information on each one of them is required to understand the mechanism of action of all of them because of their specificity. Unraveling the mechanism will help in the ultimate goal of developing inhibitors as antibotulinum drugs for the toxins. Here, we report the high-resolution structure of active BoNT/F catalytic domain in two crystal forms. The structure was exploited for modeling the substrate binding and identifying the S1' subsite and the putative exosites which are different from BoNT/A or BoNT/B. The orientation of docking of the substrate at the active site is consistent with the experimental BoNT/A-LC:SNAP-25 peptide model and our proposed model for BoNT/E-LC:SNAP-25.
39915211
How should hypertension be assessed and managed in hemodialysis patients? Home BP, not dialysis unit BP, should be used for managing hypertension.
206196304
Interdialytic hypertension-an update.
The reference standard for diagnosing hypertension among hemodialysis patients is 44-hour interdialytic ambulatory blood pressure (BP) recording. However, a more practical way to diagnose and manage hypertension is to measure home BP over the interdialytic interval. In contrast to pre- and postdialysis BP recordings, measurements of BP performed outside the dialysis unit correlate with the presence of left ventricular hypertrophy and directly and strongly with all-cause mortality. Hypervolemia that is not clinically obvious is the most common treatable cause of hypertension among patients with end-stage renal disease; thus, volume control should be the initial therapy to treat hypertension in most hemodialysis patients. To diagnose hypervolemia, continuous blood volume monitoring is emerging as an effective and simple technique. Reducing dietary and dialysate sodium is an often overlooked strategy to improve BP control. Although definitive randomized trials that show cardiovascular benefits of BP lowering among hypertensive hemodialysis have not been performed, emerging evidence suggests that lowering BP might reduce cardiovascular events. The treatment should be guided by BP obtained outside the dialysis unit because predialysis and postdialysis BP are quite variable and agree poorly with measurements obtained outside the dialysis unit. Although the appropriate level to which BP should be lowered remains elusive, current data suggest that interdialytic ambulatory systolic BP should be lowered to <130 mm Hg and averaged home systolic BP to <140 mm Hg. Antihypertensive drugs will be required by most patients receiving thrice weekly dialysis for 4 hours. Beta blockers, dihydropyridine calcium blockers, and agents that block the renin-angiotensin system appear to be effective in lowering BP in these patients.
556786
A novel mode of dimerization via formation of a glutamate anhydride crosslink in a protein crystal structure.
Acid anhydrides are formed by removal of water, are very active, and can react with water to form the original binary components.
19545652
What can we learn from null randomized controlled trials?
Cardiovascular disease is an important cause of mortality and morbidity in patients with CKD. Elevated serum phosphorus concentration is associated with an increased cardiovascular event rate. Recent data suggest that even in the normal range, serum phosphorus concentration is associated with an