Reactive oxygen species in rostral ventrolateral medulla modulate cardiac sympathetic afferent reflex in rats

AIM

The aim of the present study was to investigate whether reactive oxygen species (ROS) in rostral ventrolateral medulla (RVLM) modulate cardiac sympathetic afferent reflex (CSAR) and the enhanced CSAR response caused by microinjection of angiotensin II (Ang II) into the paraventricular nucleus (PVN).

METHODS

Under urethane and alpha-chloralose anaesthesia, renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) were recorded in sinoaortic-denervated and cervical-vagotomized rats. The CSAR was evaluated by the RSNA response to epicardial application of capsaicin (1.0 nmol).

RESULTS

Bilateral RVLM microinjection of tempol (a superoxide anion scavenger) or polyethylene glycol-superoxide dismutase (PEG-SOD, an analogue of endogenous superoxide dismutase) attenuated the CSAR, but did not cause significant change in baseline RSNA and MAP. NAD(P)H oxidase inhibitors apocynin or phenylarsine oxide (PAO) also showed similar effects, but SOD inhibitor diethyldithio-carbamic acid (DETC) enhanced the CSAR and baseline RSNA, and increased the baseline MAP. Bilateral PVN microinjection of Ang II (0.3 nmol) enhanced the CSAR and increased RSNA and MAP, which was inhibited by the pre-treatment with RVLM administration of tempol, PEG-SOD, apocynin or PAO. The pre-treatment with DETC in the RVLM only showed a tendency in potentiating the CSAR response of Ang II in the PVN, but significantly potentiated the RSNA and MAP responses of Ang II.

CONCLUSION

These results suggest that the NAD(P)H oxidase-derived ROS in the RVLM modulate the CSAR. The ROS in the RVLM is necessary for the enhanced CSAR response caused by Ang II in the PVN.

The location of lymphangiogenesis is an independent prognostic factor in rectal cancers with or without preoperative radiotherapy

BACKGROUND

Lymphangiogenesis and angiogenesis are essential for tumour development and progression. The lymphatic vessel density (LVD) and blood vessel density (BVD) and their relationship to outcome have been studied extensively, however the clinical significance of the location of LVD/BVD in tumour is not known. In the present study, the location and degree of LVD/BVD and their relationship to preoperative radiotherapy (RT), clinicopathological, histopathological and biological factors were studied in rectal cancer patients participating in a Swedish clinical trial of preoperative RT.

PATIENTS AND METHODS

The location and degree of LVD/BVD were analysed in primary tumours (n = 138/140) and in their subgroups of non-RT (n = 74) and RT (n = 64/66). Further, the degree of LVD/BVD was examined in the corresponding distant normal mucosa (n = 35/31) and adjacent normal mucosa (n = 72/91). All sections were immunohistochemically examined by using D2-40 and CD34 antibodies.

RESULTS

In the whole series of the patients, a higher LVD at the periphery was related to negative p53 expression (P = 0.03) and favourable survival independent of tumour-node-metastasis stage, differentiation and p53 expression (P = 0.03). LVD was increased in p53-negative tumours after RT (P = 0.01).

CONCLUSION

LVD at the periphery of the tumour was an independent prognostic factor in rectal cancer patients.

Association study of IFNAR2 and IL10RB genes with the susceptibility and interferon response in HBV infection

A recent genome-wide association study discovered that two polymorphisms, interferon (IFN) alpha receptor 2 (IFNAR-2) F8S and interleukin 10 receptor (IL10RB) K47E, were associated with susceptibility to hepatitis B virus (HBV) infection in Africa. Here, we reevaluate the effects of the two polymorphisms on HBV susceptibility in the Chinese Han population, and extended the study to look at their association with IFN response in chronic hepatitis B (CHB). We included 341 patients with CHB and 341 unrelated controls presenting with asymptotic HBV self-limited infection, who were well matched in age and sex. In the CHB group, 101 patients had been treated with peg-IFN-alpha-2a for 48 weeks and followed up for 24 weeks to determine the clinical response, resulting 34 individuals with sustained virological response (SVR) and 67 individuals with nonsustained response (NR). Subgroups in the CHB group were divided according to the viral loads, HBeAg and maternal HBsAg status. The association with the susceptibility to HBV infection was only observed for IL10RB K47E when we compared the individuals with persistent HBV infection through nonmaternal transmission to the controls with asymptomatic self-limited HBV infection. Further, we found that the IFNAR2-8SS genotype was associated with HBeAg negative patients (OR = 0.316, 95% CI: 0.121-0.825, P = 0.019) and that the IFNAR2-8F allele was associated with the risk to high viral loads (OR = 1.667, 95% CI: 1.148-2.420, P = 0.007). In addition, the IFNAR2-8FF genotype predisposed to higher MxA gene induction and correlated with sustained IFN response (OR = 0.348, 95% CI: 0.129-0.935, P = 0.036). Haplotype analysis based on polymorphisms of three single-nucleotide polymorphisms, MxA - 88 G/T, IFNAR-2 F8S and IL10RB K47E showed that the haplotype distribution was significantly different between the SVR and NR groups (P = 0.040). This study suggests that IFNAR2 may play an important role in determining IFN response and clinical phenotypes of HBV infection in the Chinese Han population.

Glyceryl trinitrate for prevention of pancreatitis after endoscopic retrograde cholangiopancreatography: a meta-analysis of randomized, double-blind, placebo-controlled trials

BACKGROUND AND STUDY AIMS

Although trials evaluating the preventive effect of glyceryl trinitrate (GTN; nitroglycerin) on pancreatitis occurring after endoscopic retrograde cholangiopancreatography (ERCP) have been reported, there is no agreement as to whether prophylactic GTN treatment can in fact reduce the incidence of post-ERCP pancreatitis. We performed a meta-analysis to compare the effects of prophylactic GTN with placebo on post-ERCP pancreatitis.

STUDY DESIGN

Databases including PubMed, EMBASE, the Cochrane Library, and the Science Citation Index were searched to find relevant randomized controlled trials (RCTs). Two reviewers independently identified relevant trials evaluating the prophylactic effect of GTN on the occurrence of post-ERCP pancreatitis. The outcome measure was the incidence of post-ERCP pancreatitis.

RESULTS

Eight trials involving 1920 patients were analyzed. Meta-analysis showed that the incidence of post-ERCP pancreatitis was significantly reduced by GTN treatment (GTN group 5.9 %, placebo group 9.8 %, P = 0.002), with a relative risk of 0.61 (95 % confidence interval 0.44 - 0.84). Patients who received GTN were 39 % less likely to develop pancreatitis. Subgroup analyses suggested that GTN administered by the sublingual or transdermal route may be useful.

CONCLUSIONS

Prophylactic GTN is useful for prevention of post-ERCP pancreatitis, but the optimal dosage and the optimal route and timing of administration need further clarification before this treatment can come into routine clinical use.

CHARMM: the biomolecular simulation program

CHARMM (Chemistry at HARvard Molecular Mechanics) is a highly versatile and widely used molecular simulation program. It has been developed over the last three decades with a primary focus on molecules of biological interest, including proteins, peptides, lipids, nucleic acids, carbohydrates, and small molecule ligands, as they occur in solution, crystals, and membrane environments. For the study of such systems, the program provides a large suite of computational tools that include numerous conformational and path sampling methods, free energy estimators, molecular minimization, dynamics, and analysis techniques, and model-building capabilities. The CHARMM program is applicable to problems involving a much broader class of many-particle systems. Calculations with CHARMM can be performed using a number of different energy functions and models, from mixed quantum mechanical-molecular mechanical force fields, to all-atom classical potential energy functions with explicit solvent and various boundary conditions, to implicit solvent and membrane models. The program has been ported to numerous platforms in both serial and parallel architectures. This article provides an overview of the program as it exists today with an emphasis on developments since the publication of the original CHARMM article in 1983.

Corticosterone administration induces oxidative injury in skeletal muscle of broiler chickens

The present study had been conducted to explore the effect of corticosterone (CORT) on the induction of lipid peroxidation in skeletal muscle. The experimental chickens were subjected to 1 single s.c. injection of CORT (4 mg/kg of BW). Blood samples were obtained at the beginning and end of a 3-h experimental period. Muscle samples were obtained from musculus pectoralis major and musculus biceps femoris (BF) before and immediately after slaughter, and at 24- and 48-h time points postmortem. The result showed that plasma level of TBA reacting substances (TBARS) was significantly increased, whereas the activity of super-oxide dismutase was decreased after CORT injection. Plasma level of total antioxidant power, as reflected by the ferric reducing-antioxidant power, was increased by CORT administration. The preslaughter level of TBARS could be increased by CORT administration in pectoralis major. In contrast, although the preslaughter level of TBARS was not significantly changed by CORT administration in BF, the augmented TBARS level was detected at 48 h postmortem in BF of CORT chickens. During the period of storage, the concentrations of TBARS increased, whereas ferric reducing-antioxidant power level decreased over time regardless of treatment. In conclusion, the data suggest that elevated CORT due to preslaughter stress would affect the redox balance in skeletal muscle. The result suggested that the oxidative stability during storage of meat is associated with the alteration in muscle physiology induced by CORT administration.

Effects of cevoglitazar, a dual PPARalpha/gamma agonist, on ectopic fat deposition in fatty Zucker rats

AIM

By acting as both insulin sensitizers and lipid-lowering agents, dual-acting peroxisome proliferator-activated receptors alpha/gamma (PPARalpha/gamma) agonists may be used to improve glucose tolerance in type 2 diabetic patients without inducing adiposity and body weight gain. Here, in an animal model of obesity and insulin resistance, the metabolic response to cevoglitazar, a dual PPARalpha/gamma, was characterized using a combination of in vivo and ex vivo magnetic resonance methodologies and compared to treatment effects of fenofibrate, a PPARalpha agonist, and pioglitazone, a PPARgamma agonist.

METHODS

Four groups of fatty Zucker rats: (i) Vehicle; (ii) fenofibrate 150 mg/kg; (iii) pioglitazone 30 mg/kg; and (iv) cevoglitazar 5 mg/kg were investigated before and after treatment. Animals were fed a fat-enriched (54% kcal fat) diet for 6 weeks, 2 weeks high of fat-exposure alone followed by a 4-week dosing period.

RESULTS AND CONCLUSIONS

Cevoglitazar was as effective as pioglitazone at improving glucose tolerance. However, unlike pioglitazone, both fenofibrate and cevoglitazar reduced BW gain and adiposity, independent of food intake. All three treatment regimens normalized intramyocellular lipids. Metabolic profiling showed that in the muscle cevoglitazar improves the lipid profile via both PPARalpha- and PPARgamma-mediated mechanisms. Pioglitazone reduced hepatic lipid accumulation, while cevoglitazar and fenofibrate reduced hepatic lipid concentration below baseline levels (p < 0.05). Metabolic profiling showed that in the liver, cevoglitazar functions largely through PPARalpha agonism resulting in increased beta-oxidation. Cevoglitazar only induced small changes to the lipid composition of visceral fat. In subcutaneous fat, however, cevoglitazar induced changes similar to those observed with fenofibrate suggesting export of fatty acids from this depot.

Impact of the number of cycles on efficacy of denileukin diftitox (Dd) in subjects with cutaneous T-cell lymphoma (CTCL)

e19549

Background: Dd, a recombinant fusion protein designed to target interleukin-2 receptor-expressing malignancies, is the most extensively studied agent in patients with CTCL. Dd is approved for 8 cycles in CTCL. Here, we present data from study L4389–11 on the effect of treatment course on the efficacy of Dd. Methods: Subjects received Dd doses of 9 or 18 mcg/kg IV daily for 5 days, repeating every 21 days for up to 8 courses. The majority of subjects had CTCL stage ≤ IIa at baseline. Thirty three percent of subjects had received 2 prior anticancer therapies and 23% had received 3 prior anticancer therapies. For all subjects (n=144), the overall median age was 59 years. Tumor burden in skin, blood and lymph nodes and a physician's global assessment were determined at each study visit relative to baseline. Response confirmation was adjudicated by an independent Data Endpoint Review Committee (DERC) after 3 consecutive courses. The primary endpoint was ORR including CR (no clinical evidence of disease based on tumor burden assessments and photography and histopathology of skin biopsy indicated absence of atypical cells), CCR (no clinical evidence of disease based on tumor burden assessments and photography and either the presence of atypical cells was indicated by histopathology of a skin biopsy or histopathology was unavailable) and PR (≥ 50% reduction in measured tumor burden). Data reflect the first treatment course in which the best response was recorded for Dd-treated subjects who responded (n=44) based on the DERC assessment. All responses counted were confirmed in 2 successive assessments. Results: 45% of best responses occurred in cycles 4 thru 8 and the evolution to CR occurred from 4 cycles and beyond. Conclusions: These data support the approved 8 cycles of Dd therapy in CTCL.

[Table: see text]

Effect of dose on denileukin diftitox (Dd) response in treatment-naïve cutaneous T-cell lymphoma (CTCL) subjects: A retrospective analysis of three phase III studies

e19509

Background: Three phase III studies (10, 11, 14) have been conducted with Dd, a novel IL-2 receptor-targeted recombinant fusion protein, in subjects with CTCL. Dd is approved for the treatment of persistent/recurrent CD25(+) CTCL and is the most extensively studied agent in CTCL. We retrospectively analyzed the efficacy of two Dd doses in treatment-naïve CD25(+) CTCL subjects to understand the relationship between dose and response to therapy. Methods: Studies 10 and 11 included early or advanced stage CD25(+) subjects (CD25 immunostaining in >20% of malignant cells) while 14 included CD25(-). Subjects received 9 or 18 mcg/kg/day IV for 5 days, repeating every 21 days for up to 8 courses; subjects in study 14 only received the higher dose. Study 11 included a placebo arm. Subject demographics were similar among the three studies and between the 2 dose groups in each. Response confirmation required ≥2 consecutive courses (3 observations) and was adjudicated by an independent Data Endpoint Review Committee in each study, using a weighted severity skin, blood and lymph node count. The primary endpoint was ORR (CR, CCR, PR) and the key secondary endpoint was progression-free survival (PFS). Results: Integrated efficacy results for ORR and PFS are shown in the table for treatment-naïve CD25(+) subjects. In general, the nature and incidence of the adverse events reported in the 3 studies were similar, with studies 11 and 14 proving to be broadly consistent with study 10 in terms of safety. Tolerability of 9 and 18 mcg/kg/d was similar in study 10. In study 11, the only AEs that were more frequent in the high-dose group were vomiting (13.3% vs 34.5%) and dysgeusia (0% vs 10.9%). Conclusions: Overall, there was a trend towards higher efficacy favoring 18 mcg/kg/day in treatment-naïve CD25(+) subjects. The ORR was statistically significant for the higher dose group.

[Table: see text]

Engineering of functional contractile cardiac tissues cultured in a perfusion system

Overcoming the limitations of diffusional transport in conventional culture systems remains an open issue for successfully generating thick, compact and functional cardiac tissues. Previously, it was shown that perfusion systems enhance the yield and uniformity of cell seeding and cell survival in thick cardiac constructs. The aim of our study was to form highly functional cardiac constructs starting from spatially uniform, high density cell seeded constructs. Disk-shaped elastomeric poly(glycerol sebacate) scaffolds were seeded with neonatal rat cardiomyocytes and cultured for eight days with direct perfusion of culture medium or statically in a six-well plate. In the perfusion experimental group, the integrity of some disks was well maintained, whereas in others a central hole was formed, resulting in ring-shaped constructs. This allowed us to also study the effects of construct geometry and of interstitial flow versus channel perfusion. The ring-shaped constructs appeared to have a denser and more uniform deposition of extracellular matrix. In response to electrical stimulation, the fractional area change of the ring-shaped constructs was 7.3 and 2.7 times higher than for disk-shaped tissues cultured in perfusion or statically, respectively. These findings suggest that a combination of many factors, including scaffold elasticity and geometry and the type of perfusion system applied, need to be considered in order to engineer a cardiac construct with high contractile activity.

Morphology-controlled synthesis and a comparative study of the physical properties of SnO2 nanostructures: from ultrathin nanowires to ultrawide nanobelts

Controlled synthesis of one-dimensional materials, such as nanowires and nanobelts, is of vital importance for achieving the desired properties and fabricating functional devices. We report a systematic investigation of the vapor transport growth of one-dimensional SnO(2) nanostructures, aiming to achieve precise morphology control. SnO(2) nanowires are obtained when SnO(2) mixed with graphite is used as the source material; adding TiO(2) into the source reliably leads to the formation of nanobelts. Ti-induced modification of crystal surface energy is proposed to be the origin of the morphology change. In addition, control of the lateral dimensions of both SnO(2) nanowires (from approximately 15 to approximately 115 nm in diameter) and nanobelts (from approximately 30 nm to approximately 2 microm in width) is achieved by adjusting the growth conditions. The physical properties of SnO(2) nanowires and nanobelts are further characterized and compared using room temperature photoluminescence, resonant Raman scattering, and field emission measurements.

The impact of smoking and quitting on household expenditure patterns and medical care costs in China

BACKGROUND

Smoking remains very common in Chinese men, and the economic burden caused by cigarette consumption on smokers and their families may be substantial. Using a large nationally representative household survey, the third National Health Services Survey (NHSS, 2003), we estimated the economic impact of smoking on households.

METHODS

Smoking status of all household members (over 15 years) was collected by interview for the NHSS, and households classified into one of seven categories based on their smoking status. Information on household income and expenditure, and use of health services was also obtained. We assessed both the "direct" costs (reducing funds available for spending on other commodities such as food, education, medical care, etc, using a fractional logit model), and "indirect costs" (increasing medical expenditures, using a log-linear model).

RESULTS

Every five packets of cigarettes consumed per capita per month reduces household spending on other commodities, most notably on education (by about 17 yuan per capita per annum) and medical care (11 yuan). The effects are greatest among low-income rural households. Households with quitters spend substantially more on medical care than never-smoking households (64 yuan for households with two or more quitters).

CONCLUSIONS

If a household member smokes, there is less money available for commodities such as education and medical care. Medical care expenditure is substantially higher among households with quitters, as ill-health is the main reason for quitting smoking in China. Smoking impoverishes a substantial number of poorer rural households.

Clinical and biological significance of angiogenesis and lymphangiogenesis in colorectal cancer

BACKGROUND

Angiogenesis and lymphangiogenesis are essential for tumour development and progression. However, in colorectal cancer (CRC), the relationship between angiogenesis and clinical outcome is controversial, and the prognostic significance of lymphangiogenesis is not well examined because of the lack of specific a marker for lymphatic vessels.

AIMS

To evaluate blood microvessel density (MVD) following the proposed standard method for MVD assessment given by the first international consensus and lymphatic vessel density (LVD), and investigate their clinicopathologic and biologic significance in CRC.

METHODS

MVD and LVD in primary tumours (n=210), along with their corresponding adjacent normal mucosa (n=105) and distant normal mucosa (n=27) specimens, were immunohistochemically examined by using CD31 and D2-40 antibodies.

RESULTS

Both MVD and LVD were higher in tumour compared with the corresponding normal mucosa. In tumours, MVD was positively related to particular interesting new cysteine-histidine-rich protein (PINCH) expression (P=0.006), but not with clinicopathologic variables. LVD, in both intratumoural and peritumoural areas of tumours, was reversely related to Dukes' stage. There was no association between MVD or LVD and patients' survival (P>0.05).

CONCLUSIONS

Angiogenesis and lymphangiogenesis occurred in CRC development, but were not related to CRC patient prognosis. PINCH may play a potential role in tumour angiogenesis.

Mammographic density and breast cancer risk factors in Chinese women

Abstract #4082

Background: Past studies have indicated that mammographic density is associated with not only breast cancer risk but also breast cancer risk factors in women living in western nations. However, to data, no such association has been shown among native Chinese women. The aim of this cross-sectional study was to investigate the effects of age, body mass index (BMI), age at menarche, parity, and menopausal status on mammographic patterns in women from a province of Northern China.&#x2028; Methods: Seven hundred and two women's mammograms and information of the breast cancer risk factors were obtained from Shanxi province cancer hospital in Northern China. Mammograms were assessed according to the Wolfe classification.&#x2028; Results: Age, BMI, parity, and menopause were inversely and independently related to high-risk mammographic parenchymal patterns. However, there was no statistically significant association between age at menarche and high mammographic density. Relative to subjects aged less than or equal to 35 years, subjects aged greater than 55 years had reduced 62% (OR = 0.38, 95% CI: 0.14 – 1.00) odds of having a high-risk pattern. In comparison to women whose BMI was less than or equal to 25, there was a 51% and 72% reduction in the odds of having high-risk mammographic patterns for those with BMI 25 to 30 and larger than or equal to 30 respectively (OR = 0.49, 95% CI: 0.32 - 0.74; OR = 0.28, 95% CI: 0.12 - 0.68 respectively). Women with more than three children had decreased 68% risk to have high mammographic density compared to those who were nulliparous (OR = 0.32, 95% CI: 0.1 – 1.0). Premenopausal women were more than four times likely to have a high-risk pattern than postmenopausal women (OR = 4.12, 95% CI: 2.17 – 7.87).&#x2028; Conclusion: Our findings demonstrated that mammographic parenchymal patterns are also associated with some risk factors of breast cancer in native Chinese women. This is consistent with most studies carried out in Western countries. Further studies are needed to determine the relationship between quantitative percentage density and breast cancer risk factors.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4082.