Regional hypothermia reduces mucosal NF-kappaB and PMN priming via gut lymph during canine mesenteric ischemia/reperfusion

BACKGROUND: Mesenteric ischemia/reperfusion (I/R) activates pro-inflammatory mediators that exacerbate gut reperfusion injury and prime circulating neutrophils that cause remote organ injury. We have shown that regional intraischemic hypothermia protects the intestinal mucosa during I/R in rats. In this study, we examined the effects of regional hypothermia on I/R-induced transvascular protein clearance, NF-kappaB DNA binding activity, and polymorphonuclear neutrophil (PMN) priming via gut lymph in a canine mesenteric lymphatic fistula model. MATERIALS AND METHODS: Conditioned dogs underwent 60 min of mesenteric ischemia, with or without regional intraischemic hypothermia, and 3 h reperfusion. A mesenteric lymphatic fistula model was used to measure transvascular protein clearance and harvest lymph. Biopsies of distal ileum were obtained at baseline and 0, 180 min of reperfusion for NF-kappaB DNA binding activity using electrophoretic mobility shift assay (EMSA). A kinetic spectrophotometric assay was used to determine fMLP stimulated PMN superoxide production after priming by gut lymph obtained at baseline and 180 min reperfusion. RESULTS: Transvascular protein clearance increased during reperfusion compared to baseline, and hypothermia had no significant effect on this I/R-induced protein clearance. NF-kappaB activity increased three-fold at the end of ischemia and hypothermia prevented this early activation. PMN superoxide production increased 19-fold during I/R (0.06 +/- 0.04 versus 1.14 +/- 0.50 nmol O(2), P < 0.05), but only 2.5-fold during I/R + hypothermia (0.28 +/- 0.09 versus 0.70 +/- 0.32 nmol O(2), P = 0.2). CONCLUSIONS: Regional intraischemic hypothermia prevented early intestinal NF-kappaB activation, partially abrogated PMN priming via gut lymph, but had no significant effect on increased transvascular protein clearance during mesenteric I/R in dogs.     

Epirubicin and meglumine gamma-linolenic acid: a logical choice of combination therapy for patients with superficial bladder carcinoma

BACKGROUND: Anthracyclines have been established as first-line drugs for intravesical use in the treatment of patients with superficial bladder carcinoma, although they result only in a modest reduction in tumor recurrence rates. The essential fatty acid gamma-linolenic acid (GLA) also is an effective cytotoxic agent against superficial bladder carcinoma when it is applied topically. The objective of this study was to assess the efficacy of combined epirubicin and GLA with the purpose of developing a suitable model for modification of existing intravesical regimens. METHODS: The human urothelial carcinoma cell lines MGH-U1 and RT112 were used in standard cytotoxicity assays and were exposed to meglumine GLA (MeGLA) and epirubicin in two-dimensional concentration matrices. A thiozolyl blue (methyl-thiazoldiphenyl tetrazolium) assay was used to determine residual cell biomass. Drug interaction was quantified by median-effect analysis software (CalcuSyn), and the evaluation of drug uptake utilized fluorescence confocal microscopy (FCM) and flow cytometry. RESULTS: MeGLA caused a significant enhancement of anthracycline uptake, viewed by FCM, from 92 fluorescence units to 222 fluorescence units (P < 0.001). Flow cytometry confirmed the increased drug uptake and showed that the mean epirubicin content per cell increased from 23 to 57 units and from 8 to 24 units for MGH-U1 and RT112 cells, respectively (99% confidence interval < 0.3). This resulted in improved cytotoxicity, and it was shown that the drugs acted synergistically with all but the highest MeGLA concentrations. CONCLUSIONS: The efficacy of epirubicin was enhanced significantly when it was used in combination with most concentrations of MeGLA (< 300 microg/mL), and the two agents acted synergistically. There was a corresponding increase in epirubicin uptake by cells under these conditions. At high MeGLA concentrations, however, anthracycline solubility was compromised, and drug synergy was lost.     

Alefacept (Biogen)

Alefacept (B-9273) is an LFA-3-Ig fusion protein CD2 antagonist under development by Biogen for the potential treatment of autoimmune diseases, including psoriasis and transplant rejection [270267]. It is in phase III trials for psoriasis [349467]. In October 2000, the company reported that Amevive was on track for regulatory filing in the second half of 2001 [385250], with a possible launch in the second half of 2002 [395628]. The company began a pivotal phase III trial in the US in December 1999, involving patients with chronic plaque psoriasis [349467]. A second phase III trial has also been initiated [362199], [374040]. Results from both trials are expected in mid-2001 [396544]. In April 2001, SalomonSmithBarney confirmed that a regulatory filing was expected in Europe and the US in the second half of 2001 and stated that alefacept would be critical to the future earnings growth of the company [407796]. In June 1999, Merrill Lynch estimated product launch in 2001 [327145], [344773]. Sales in 2001 and 2002 were anticipated to be US $20 million and US $100 million, respectively [327145].     

Economic valuation of health risk exposure of restaurant users in Dhaka city

The aim of the study presented in this paper is to estimate the economic cost of health risk exposure of the restaurant users in Dhaka city. In a large-scale survey, 400 restaurant users in Dhaka city belonging to lower-middle to high income group were asked for their preferences for a hypothetical ‘Food Safety Inspection Programme’ using closed ended dichotomous choice contingent valuation questions. The study reveals an average estimated willingness to pay of Tk31 (US$ 0.5) which is 13% of the average restaurant bill per visit per person. Aggregating the overall willingness to pay estimate across the whole population, a reduction in restaurant food-related health risk results in a total economic benefit of Tk2,250 million (US$33million) per year. The study, furthermore, reveals that the respondent' willingness to pay for the Inspection Programme varies with the degree of health risk exposure, respondent' income level, frequency of restaurant visits, the disutility from health risks and the levels of self-protection. Two different health risk indicators, subjective (respondent perceived probability of becoming ill after eating in a restaurant) and objective (experience of negative health incidences from low quality restaurant food), have been used to test the consistency of influence of health risk exposure on stated willingness to pay. Better model fit has been observed with the objective health risk exposure. The results from the statistical models indicate that the offered bid amounts (additional amount of money that the restaurant users need to pay in order to finance the Inspection Programme) affects willingness to pay negatively. We find income, frequency of restaurant visits and health consciousness influencing willingness to pay for the Inspection Programme positively. Finally, our results confirm the hypothesis that willingness to pay for health risk reduction varies positively with the levels of risk exposure independent of the type of indicators (subjective or objective) we use to measure health risk.     

Inverse correlation between p53 protein levels and DNA repair efficiency in human fibroblast strains treated with 4-nitroquinoline 1-oxide: evidence that lesions other than DNA strand breaks trigger the p53 response.

Ionizing radiation-induced stabilization and the resultant transient accumulation of the p53 tumor suppressor protein is impaired in cells from ataxia telangiectasia (AT) patients, indicating a key role for ATM, the gene mutated in AT, upstream in the radiation-responsive p53 signaling pathway. Activation of this pathway is generally assumed to be triggered by DNA strand breaks produced directly following genotoxic stress or indirectly during excision repair of DNA lesions. The aim of this study was to identify the triggering signal for induction of p53 in diploid human dermal fibroblasts treated with 4-nitroquinoline 1-oxide (4NQO), a model environmental carcinogen that produces both DNA strand breaks (like ionizing radiation) and alkali-stable bulky DNA lesions (like UV light). 4NQO treatment of fibroblasts cultured from normal and AT donors and those from patients with the UV-hypersensitivity disorder xeroderma pigmentosum (XP, complementation groups A, E and G) resulted in up-regulation of p53 protein. In normal fibroblasts, there was no temporal relationship between the incidence of DNA strand breaks and levels of p53 protein; >90% of strand breaks and alkali-labile sites were repaired over 2 h following treatment with 1 microM 4NQO, whereas approximately 3 h of post-treatment incubation was required to demonstrate a significant rise in p53 protein. In contrast, exposure of normal fibroblasts to gamma-rays resulted in a rapid up-regulation of p53 and the level peaked at 2 h post-irradiation. XP cells with a severe deficiency in the nucleotide excision repair pathway showed abnormally high levels of p53 protein in response to 4NQO treatment, indicating that lesions other than incision-associated DNA strand breaks trigger p53 up-regulation. We observed a consistent, inverse correlation between the ability of the various fibroblast cultures to induce p53 following 4NQO treatment and their DNA repair efficiencies. Treatment with 0.12 microM 4NQO, for example, caused a >2-fold up-regulation of p53 in excision repair-deficient (AT, XPA and XPG) strains without eliciting any effect on p53 levels in repair-proficient (normal and XPE) strains. We conclude that up-regulation of p53 by 4NQO is mediated solely by an ATM-independent mechanism and that the p53 response is primarily triggered by persistent alkali-stable 4NQO-DNA adducts.     

Peroxynitrite modified DNA may be an antigenic trigger for antibodies in various cancers of gynecologic origin

This study aimed towards probing the role of peroxynitrite damaged human DNA (ONOO^–-DNA) in the induction of circulating antibodies in certain cancers of gynecologic origin. We have compared the binding specificity of DNA isolated from the lymphocytes of cancer patients with that of the experimentally modified DNA. Also, the induced anti-ONOO⁻-DNA antibodies have been used to probe oxidative damage in the DNA isolated from cancer patients. Human placental DNA was modified with peroxynitrite (ONOO⁻) and analyzed by ultraviolet (UV) and fluorescence spectroscopy, gel electrophoresis, thermal denaturation profile, etc. Antibodies against modified DNA were induced in experimental animals. Specific binding of the antibodies was evaluated by ELISA and band shift assay. 91 cancer patients were selected and grouped according to the type of cancer. Specific binding characteristics of circulating autoantibodies (IgG) were determined by competitive-inhibition ELISA, using different inhibitors. Maximum inhibition of antibody activity by ONOO⁻-DNA reflected specific recognition of modified epitopes by cancer IgG. This shows generation of neo-epitopes on DNA, upon modification with ONOO⁻, that are recognized by cancer IgG. Our results indicate epitope sharing between the DNA isolated from cancer patients and the in-vitro modified ONOO⁻-DNA. The possible role of nitrosative stress in the gynecologic oncology has been discussed.     

The effect of lathyrism on dentin structure of the rat incisors: a morphometric and scanning electron microscopic investigation

J Oral Pathol Med (2010) 39 : 424–430 Background: The present study was designed to study the effect of β‐aminopropionitrile (β‐APN), present in Lathyrus sativus grass pea consumed in drought prone areas, on dentin of the continuously erupting rat incisors. Methods: Eighteen adult male rats were used. In the experimental group (18 rats), lathyrism was induced by a once daily subcutaneous administration of β‐APN for 40 days. The maxillary and mandibular incisors were examined ultrastructurally and morphometrically. Results: The mean number of patent tubules, the mean area, perimeter and the area percent of the tubules were analyzed. Ultrastructurally, the dentinal tubules of both coronal and radicular dentin in the lathyritic group were narrower or even obliterated compared with those in the control. The coronal and radicular dentin of the lathyritic group exhibited an irregular lattice of non‐mineralized small branching collagen fibrils obliterating the dentinal tubules. The mean number of patent tubules in the control and lathyritic groups revealed an insignificant difference. The mean area of the tubules showed a statistically significant difference in lathyritic radicular dentin (P = 0.0353). The percentage of the total surface area of the dentinal tubules significantly decreased in the radicular dentin of the lathyritic group (P = 0.024). Conclusions: These findings indicated a deleterious effect of lathyrism on dentin, with a possible negative impact on developing teeth integrity.