Polymorphisms in Alcohol Metabolizing Genes and the Risk of Head and Neck Cancer in a Brazilian Population

Aims: The incidence of head and neck cancer (HNC) in Brazil has increased substantially in recent years. This increase is likely to be strongly associated with alcohol and tobacco consumption, but genetic susceptibility also should be investigated in this population. The aim of this study was to evaluate the association of polymorphisms in genes of alcohol metabolism enzymes and the risk of HNC. Methods: A hospital-based case-control study was conducted in Sao Paulo, Brazil. We here investigated ADH1C Ile(350)Val, ADH1B Arg(48)His, ADH1B Arg(370)Cys and CYP2E1*5A PstI polymorphisms by PCR-RFLP Polymerase Chain Reaction - Restriction Fragment Length Polymorphism in 207 histopathologically confirmed HNC cases (184 males and 23 females) and 244 cancer-free controls (225 males and 19 females) admitted as in-patients in the same hospital. Results: Chronic alcohol intake increased approximately four times the risk of HNC. The mutant genotype ADH1B Arg(48)His was more frequent in controls (12.7%) than HNC patients (5.8%) conferring protection for the disease (odds ratio (OR) = 0.42; 95% confidence interval (CI ), 0.21-0.85). Similar results were observed for individuals with ADH1B*2 (OR = 0.41; 95% CI , 0.20-0.82) or ADH1B*2/ADH1C*1 (OR = 0.32; 95% CI , 0.13-0.79) mutated haplotypes. Multiple regression analyses showed that individuals with the mutant genotype ADH1B Arg(48)His who consume alcohol > 30 g/L/day have more than four times the risk for HNC (OR = 4.42; 95% CI, 1.21-16.11). Conclusions: The fast alcohol metabolizing genotypes may prevent HNC when the amount of alcohol intake is < 30.655 g/L/day.

CYP1A2*1C, CYP2E1*5B, and GSTM1 polymorphisms are predictors of risk and poor outcome in head and neck squamous cell carcinoma patients

Head and neck squamous cell carcinoma (HNSCC) is associated with environmental factors, especially tobacco and alcohol consumption. Most of the carcinogens present in tobacco smoke are converted into DNA-reactive metabolites by cytochrome P450 (CYPs) enzymes and detoxification of these substances is performed by glutathione S-transferases (GSTs). It has been suggested that genetic alterations, such as polymorphisms, play an important role in tumorigenesis and HNSCC progression. The aim of this study was to investigate CYP1A1, CYP1A2, CYP2E1, GSTM1, and GSTT1 polymorphisms as risk factors in HNSCC and their association with clinicopathologic data. The patients comprised 153 individuals with HNSCC (cases) and 145 with no current or previous diagnosis of cancer (controls). Genotyping of the single nucleotide polymorphisms (SNPs) of the CYP1A1, CYP1A2, and CYP2E1 genes was performed by PCR-RFLP and the GSTM1 and GSTT1 copy number polymorphisms (CNPs) were analyzed by PCR-multiplex. As expected, a significant difference was detected for tobacco and alcohol consumption between cases and controls (P < 0.001). It was observed that the CYP1A2*1D (OR = 16.24) variant and GSTM1 null alleles (OR = 0.02) confer increased risk of HNSCC development (P < 0.001). In addition, head and neck cancer alcohol consumers were more frequently associated with the CYP2E1*5B variant allele than control alcohol users (P < 0.0001, OR = 190.6). The CYP1A2*1C polymorphism was associated with tumor recurrence (log-rank test, P = 0.0161). The CYP2E1*5B and GSTM1 null alleles were significantly associated with advanced clinical stages (T3 + T4; P = 0.022 and P = 0.028, respectively). Overall, the findings suggested that the genetic polymorphisms studied are predictors of risk and are also associated with tumor recurrence, since they are important for determining the parameters associated with tumor progression and poor outcomes in HNSCC. (C) 2009 Elsevier Ltd. All rights reserved.

Polymorphisms of APOE and LRP genes in Brazilian individuals with Alzheimer disease

Alzheimer disease (AD) is the most frequent cause of dementia in Western countries. Putative genetic risk factors for AD are polymorphisms in the apolipoprotein E (APOE) gene and in the low-density lipoprotein receptor-related protein (LRP) gene. Our objective was to investigate the role of the APOE coding region polymorphisms epsilon 2, epsilon 3, and epsilon 4 and APOE promoter variants A/T at position -491 and G/T at -219, as well as LRP polymorphism C/T, as risk factors for AD in Brazilian individuals. One hundred and twenty patients with probable AD, along with 120 controls were analyzed. A significant difference between patients and controls for 64 alleles was observed: frequency of this allele in AD was 0.31, and 0.10 in controls. Individuals with 2 FA alleles had a higher risk for AD than subjects with only 1 such allele; presence of 1 epsilon 2 allele proved protective. The presence of the T allele of the -219 polymorphism was also associated with an increased risk of AD, but this polymorphism is in linkage disequilibrium with APOE F polymorphisms. No significant differences between patients and controls were observed for -491 APOE or LRP polymorphisms. In this Brazilian population, both the epsilon 4 allele and T -219 polymorphism were associated with an increased risk for AD.

Marijuana Smoking and the Risk of Head and Neck Cancer: Pooled Analysis in the INHANCE Consortium

Background: Marijuana contains carcinogens similar to tobacco smoke and has been suggested by relatively small studies to increase the risk of head and neck cancer (HNC). Because tobacco is a major risk factor for HNC, large studies with substantial numbers of never tobacco users could help to clarify whether marijuana smoking is independently associated with HNC risk. Methods: We pooled self-reported interview data on marijuana smoking and known HNC risk factors on 4,029 HNC cases and 5,015 controls from five case-control studies within the INHANCE Consortium. Subanalyses were conducted among never tobacco users (493 cases and 1,813 controls) and among individuals who did not consume alcohol or smoke tobacco (237 cases and 887 controls). Results: The risk of HNC was not elevated by ever marijuana smoking [odds ratio (OR), 0.88; 95% confidence intervals (95% Cl), 0.67-1.16], and there was no increasing risk associated with increasing frequency, duration, or cumulative consumption of marijuana smoking. An increased risk of HNC associated with marijuana use was not detected among never tobacco users (OR, 0.93; 95% Cl, 0.63-1.37; three studies) nor among individuals who did not drink alcohol and smoke tobacco (OR, 1.06; 95% Cl, 0.47-2.38; two studies). Conclusion: Our results are consistent with the notion that infrequent marijuana smoking does not confer a risk of these malignancies. Nonetheless, because the prevalence of frequent marijuana smoking was low in most of the contributing studies, we could not rule out a moderately increased risk, particularly among subgroups without exposure to tobacco and alcohol. (Cancer Epidemiol Biomarkers Prev 2009;18(5):1544-51)

In vitro infectivity of species of Leishmania (Viannia) responsible for American cutaneous leishmaniasis

There is little available information regarding the infectivity of New World Leishmania species, particularly those from the Amazonian Brazil, where there are six species of the subgenus Viannia causing American cutaneous leishmaniasis (ACL). The aim of this study was to compare, in vitro, the potential infectivity of the following Leishmania (Viannia) spp.: L. (V.) braziliensis from localized cutaneous leishmaniasis (LCL) and mucocutaneous leishmaniasis (MCL) patients, L. (V.) guyanensis, L. (V.) shawi, L. (V.) lainsoni and L. (V.) naiffi from LCL patients only, in cultured BALB/c mice peritoneal macrophage, as well as the production of NO by the infected cells. The infectivity of parasites was expressed by the infection index and, the nitric oxide (NO) production in the macrophage culture supernatant was measured by the Griess method. It was found that L. (V.) braziliensis from MCL, the more severe form of disease, showed the highest (p <= 0.05) infection index (397), as well as the lowest NO production (2.15 mu M) compared with those of other species. In contrast, L. (V.) naiffi which is less pathogenic for the human showed the lowest infection index (301) and the highest NO production (4.11 mu M). These results demonstrated a negative correlation between the infectivity and the ability of these parasites to escape from the microbicidal activity of the host cell.

Effects of the administration of pentoxifylline and prednisolone on the evolution of portal fibrogenesis secondary to biliary obstruction-an experimental study in growing animals

Background: Many chronic liver diseases lead to progressive hepatic fibrosis, a condition that can ultimately result in loss of organ function and severe portal hypertension necessitating hepatic transplantation. Within the last few decades, studies have been conducted to demonstrate the possibility of drug modulation of hepatic fibrogenesis. Regarding biliary obstruction, it has been suggested that administration of corticosteroids could promote better late outcomes for children with biliary atresia submitted to Kasai`s portoenterostomy. Models used to test potential antifibrogenic drugs such as pentoxifylline (PTX) have not included growing animals. Methods: In this experimental study, 119 young rats (21st or 22nd days) were submitted to laparotomy and common bile duct ligation (CBDL) or to sham surgery (SHAM). Animals were allocated into 5 groups, according to surgical procedure, and administered the following solutions: (1) CBDL + distilled water, (2) SHAM + distilled water, (3) CBDL + PTX, (4) CBDL + prednisolone (PRED), and (5) CBDL + PTX + PRED (PTX + PRED). Each group was further divided into 2 subgroups according to the length of the experiment (15 or 30 days). At the end of the defined period, animals were weighed, and a hepatic fragment was collected from each one for analyses. Results: The PTX animals exhibited increased weight gain compared to animals in the PRED or PTX + PRED groups. Animals from the 3 therapeutic groups (PTX, PRED, and PTX + PRED) showed diminished collagen-filled area in portal spaces. Total portal space area was increased in the PTX group. Conclusions: Hepatic fibrosis induced by bile duct ligation in young rats could be modulated by pharmacologic interventions. Administration of PTX or PRED, or the combination of both, resulted in diminished collagen-filled areas in portal spaces. (C) 2009 Elsevier Inc. All rights reserved.

Understanding the genetic diversity, spatial genetic structure and mating system at the hierarchical levels of fruits and individuals of a continuous Theobroma cacao population from the Brazilian Amazon

Understanding the mating patterns of populations of tree species is a key component of ex situ genetic conservation. In this study, we analysed the genetic diversity, spatial genetic structure (SGS) and mating system at the hierarchical levels of fruits and individuals as well as pollen dispersal patterns in a continuous population of Theobroma cacao in Para State, Brazil. A total of 156 individuals in a 0.56 ha plot were mapped and genotyped for nine microsatellite loci. For the mating system analyses, 50 seeds were collected from nine seed trees by sampling five fruits per tree (10 seeds per fruit). Among the 156 individuals, 127 had unique multilocus genotypes, and the remaining were clones. The population was spatially aggregated; it demonstrated a significant SGS up to 15m that could be attributed primarily to the presence of clones. However, the short seed dispersal distance also contributed to this pattern. Population matings occurred mainly via outcrossing, but selfing was observed in some seed trees, which indicated the presence of individual variation for self-incompatibility. The matings were also correlated, especially within ((r) over cap (p(m)) = 0.607) rather than among the fruits ((r) over cap (p(m)) = 0.099), which suggested that a small number of pollen donors fertilised each fruit. The paternity analysis suggested a high proportion of pollen migration (61.3%), although within the plot, most of the pollen dispersal encompassed short distances (28m). The determination of these novel parameters provides the fundamental information required to establish long-term ex situ conservation strategies for this important tropical species. Heredity (2011) 106, 973-985; doi:10.1038/hdy.2010.145; published online 8 December 2010

Effects of Pentoxyfilline and Heparin on Reperfusion Injury Island Skin Flaps in Rats Exposed to Tobacco

Background. Ischemia-reperfusion injury is believed to be a major cause of transferred skin flap failure. Cigarette smoking is known to be associated with endogenous antioxidant depletion, hypercoagulability, and cutaneous vasoconstriction. This investigation was carried out to study possible effects of pentoxyfilline or heparin on rat skin reperfusion injury under tobacco exposure. Materials and Methods. Thirty-six rats were randomized into two major groups: 18 were exposed to cigarette smoke during a 4 wk period prior to surgery; the remaining 18 underwent a sham smoking procedure. Each group was further divided into three equal subgroups: heparin, pentoxyfilline, and saline solution. One identical skin flap was raised in each animal. The vasculature of the flap was clamped for 3 h and reperfused for 5 min. A venous blood sample was obtained from the flap after reperfusion for serum malondialdehyde (MDA) and myeloperoxidase (MPO) analysis. Flap survival was assessed 7 d after the procedure. Results. The lipid peroxidation levels and flap necrosis were significantly higher in the cigarette-smoking group skin flaps. There was also a decrease of MPO activity in this group compared with the nonsmoking group. Heparin-treated rats had significantly lower MDA levels and showed the most viable percent area among smoking rats. Conclusions. These data suggest that heparin had a significant beneficial effect both on flap survival and on the lipid peroxidation reduction after smoke exposure in the rat axial-pattern skin flap subjected to ischemia and reperfusion injury. Pharmacologic therapy may represent an alternative way to counteract tobacco effects in flap surgery in emergency situations. (C) 2010 Elsevier Inc. All rights reserved.

Val/Leu(247) Polymorphism of beta 2-glycoprotein I in Brazilian Patients with Antiphospholipid Syndrome-A Genetic Risk Factor?

A genetic polymorphism of the beta 2-glycoprotein I (beta 2-GPI) is recognized by antiphospholipid antibodies (aPL) and may even play a role in the development of antiphospholipid syndrome (APS). The objectives of this study were to determine a Val/Leu SNP at position 247 of the beta 2-GPI gene in Brazilian patients with APS and to compare these data with clinical and laboratory manifestations. Polymorphism assignment was performed by PCR followed by Rsa I restriction endonuclease. The titration of anti-beta 2-GPI antibodies was detected by ELISA. The results showed significantly higher frequencies of the V-encoding allele and the homozygous VV genotype in patients with APS than in control subjects (OR = 1.781, P = 0.0068; and OR = 6.413, P < 0.0001, respectively). The frequency of this genotype was also significantly higher in patients with arterial and venous thrombosis than in the control group (52% and 44%, respectively, versus 13%). Anti-beta 2-GPI-positive patients had significantly higher frequencies of the VV genotype than the controls subjects (OR = 8.179, P < 0.0001). These results suggest that the V-encoding allele and the homozygous VV genotype at position 247 of the beta 2-GPI gene may play a role in the generation of anomalous beta 2-GPI, with consequent auto-antibody production, and in phenotype expression of arterial and venous thrombosis in APS patients.

Investigation of the in vivo activity of CYP3A in Brazilian volunteers: comparison of midazolam and omeprazole as drug markers

Objective This study compares midazolam with omeprazole as marker drugs for the evaluation of CYP3A activity in nine healthy self-reported white Brazilian volunteers. Methods Omeprazole was also used to evaluate the CYP2C19 phenotype. The volunteers received p.o. 20 mg omeprazole, and blood samples were collected 3.5 h after drug administration. After a washout period of 10 days, the volunteers received p.o. 15 mg midazolam maleate, and serial blood samples were collected up to 6 h after administration of the drug. CYP2C19 was genotyped for the allelic variants CYP2C19*1, CYP2C19*2, CYP2C19*3, and CYP2C19*17. Analysis of omeprazole, hydroxyomeprazole, omeprazole sulfone, and midazolam in plasma was carried out by LC-MS/MS. Results The volunteers genotyped as CYP2C19*1*17, CYP2C19*17*17, CYP2C19*1*1 (n=8), or CYP2C19*17*2 (n=1) presented a median hydroxylation index (omeprazole/hydroxyomeprazole) of 1.35, indicating that all of them were extensive metabolizers of CYP2C19. The volunteers (n=9) presented a 0.12 log of the omeprazole/sulfone ratio and a median oral clearance of midazolam of 17.89 ml min(-1) kg(-1), suggesting normal CYP3A activity. Conclusions Orthogonal regression analysis between midazolam clearance and log of the plasma concentrations of the omeprazole/omeprazole sulfone ratio (R=-0.7544, P < 0.05) suggests that both midazolam and omeprazole can be used as markers of CYP3A activity in the population investigated.

Assessment of Vascular Effects of Tamoxifen and Its Metabolites on the Rat Perfused Hindquarter Vascular Bed

Tamoxifen has been suggested to produce beneficial cardiovascular effects, although the mechanisms for these effects are not fully known. Moreover, although tamoxifen metabolites may exhibit 30-100 times higher potency than the parent drug, no previous study has compared the effects produced by tamoxifen and its metabolites on vascular function. Here, we assessed the vascular responses to acetylcholine and sodium nitroprusside on perfused hindquarter vascular bed of rats treated with tamoxifen or its main metabolites (N-desmethyl-tamoxifen, 4-hydroxy-tamoxifen, and endoxifen) for 2 weeks. Plasma and whole-blood thiobarbituric acid reactive substances (TBARS) concentrations were determined using a fluorometric method. Plasma nitrite and NOx (nitrite + nitrate) concentrations were determined using an ozone-based chemiluminescence assay and Griess reaction, respectively. Treatment with tamoxifen reduced the responses to acetylcholine (pD(2) = 2.2 +/- 0.06 and 1.9 +/- 0.05 after vehicle and tamoxifen, respectively; P < 0.05), while its metabolites improved these responses (pD(2) = 2.5 +/- 0.04 after N-desmethyl-tamoxifen, 2.5 +/- 0.03 after 4-hydroxy-tamoxifen, and 2.6 +/- 0.08 after endoxifen; P < 0.01). Tamoxifen and its metabolites showed no effect on endothelial-independent responses to sodium nitroprusside (P > 0.05). While tamoxifen treatment resulted in significantly higher plasma and whole blood lipid peroxide levels (37% and 62%, respectively; both P < 0.05), its metabolites significantly decreased lipid peroxide levels (by approximately 50%; P < 0.05). While treatment with tamoxifen decreased the concentrations of markers of nitric oxide formation by approximately 50% (P < 0.05), tamoxifen metabolites had no effect on these parameters (P > 0.05). These results suggest that while tamoxifen produces detrimental effects, its metabolites produce counteracting beneficial effects on the vascular system and on nitric oxide/reactive oxygen species formation.

Polymorphisms of Lewis and Secretor genes are related to breast cancer and metastasis in axillary lymph nodes

ABH and Lewis antigen expression has been associated with cancer development and prognosis, tumor differentiation, and metastasis. Considering that invasive ductal breast carcinoma (IDC) presents multiple molecular alterations, the aim of the present study was to determine whether the polymorphism of ABO, Lewis, and Secretor genes, as well as ABO phenotyping, could be associated with tumor differentiation and lymph nodes metastasis. Seventy-six women with IDC and 78 healthy female blood donors were submitted to ABO phenotyping/genotyping and Lewis and Secretor genotyping. Phenotyping was performed by hemagglutination and genotyping by the polymerase chain reaction with sequence-specific primers. ABO, Lewis, and Secretor genes were classified by individual single nucleotide polymorphism at sites 59, 1067, 202, and 314 of the Lewis gene, 428 of the Secretor gene, and 261 (O1 allele), 526 (O2 and B allele), and 703 (B allele). No association was found between breast cancer and ABO antigen expression (P = 0.9323) or genotype (P = 0.9356). Lewis-negative genotype was associated with IDC (P = 0.0126) but not with anatomoclinical parameters. Nonsecretor genotype was associated with axillary lymph node metastasis (P = 0.0149). In conclusion, Lewis and Secretor genotyping could be useful to predict respectively breast cancer susceptibility and axillary lymph nodes metastasis.

Comparison of the effects of aerobic and resistance training on cardiac autonomic adaptations in ovariectomized rats

We have compared the effects of two types of physical training on the cardiac autonomic control in ovariectomized and sham-operated rats according to different approaches: double autonomic blockade (DAB) with methylatropine and propranolol; baroreflex sensibility (BRS) and spectral analysis of heart rate variability (HRV). Wistar female rats (+/- 250 g) were divided into two groups: sham-operated and ovariectomized. Each group was subdivided into three subgroups: sedentary rats, rats submitted to aerobic trained and rats submitted to resistance training. Ovariectomy did not change arterial pressure, basal heart rate (HR), DAB and BRS responses, but interfered with HRV by reducing the low-frequency oscillations (LF = 0.20-0.75 Hz) in relation to sedentary sham-operated rats. The DAB showed that both types of training promoted an increase in the predominance of vagal tonus in sham-operated rats, but HR variations due to methylatropine were decreased in the resistance trained rats compared to sedentary rats. Evaluation of BRS showed that resistance training for sham-operated and ovariectomized rats reduced the tachycardic responses in relation to aerobic training. Evaluation of HRV in trained rats showed that aerobic training reduced LF oscillations in sham-operated rats, whereas resistance training had a contrary effect. In the ovariectomized rats, aerobic training increased high frequency oscillations (HF = 0.75-2.5 Hz), whereas resistance training produced no effect. In sham-operated rats, both types of training increased the vagal autonomic tonus, but resistance training reduced HF oscillations and BRS as well. In turn, both types of training had similar results in ovariectomized rats, except for HRV, as aerobic training promoted an increase in HF oscillations. (C) 2011 Elsevier B.V. All rights reserved.

The effect of temperature and fasting period on the viability of free-living females of Rhipicephalus sanguineus (Acari : Ixodidae) under laboratory conditions

Little is known about the effect of temperature on viability of free-living phases of the life cycle of Rhipicephalus sanguineus (Latreille, 1806) despite of its importance as vector of several pathogens. Knowledge of the effect of abiotic factors on the capacity of a given tick species to infest new hosts is important for routine experimental activities under laboratory conditions, and may be relevant to understand the transmission of pathogens. The study evaluates the viability of R. sanguineus females held at 18 +/- 1, 27 +/- 1 and 32 +/- 1 degrees C and 80 +/- 5% RH (saturation deficits of 3.0, 5.3 and 7.2 mmHg, respectively) for three fasting periods (3 and 20 days and the day when female mortality reached approximately 50% after ecdysis), under laboratory conditions. In general, the best result on viability was obtained when rabbits were infested with unfed female ticks after three or 20 fasting days at both 27 +/- 1 and 32 +/- 1 degrees C and 80 +/- 5% RH.

Detection of Leptospira spp. in semen and vaginal fluids of goats and sheep by polymerase chain reaction

Thirteen goat herds and seven sheep flocks in the state of Rio de Janeiro, Brazil were screened for leptospirosis. From the three herds and three flocks with greatest seroreactivity, 19 goats (16 females and three bucks) and 40 sheep (26 ewes and 14 rams) that were seropositive (specific anti-Leptospira titres >= 400, based on a microscopic agglutination test), were selected for more detailed studies. From those animals, samples of vaginal fluids or semen were collected for bacteriological and molecular assays. For both species of animals, the most prevalent reactions were to serovars Hardjo, Shermani, and Grippotyphosa. Although leptospires were detected by darkfield microscopy in three vaginal fluid samples (from two goats and one ewe), pure isolates were not obtained by bacteriological culture of vaginal fluids or semen. However, seven vaginal fluid samples (from four goats and three ewes) and six semen samples (all from rams) were positive on polymerase chain reaction (PCR). Based on these findings, in addition to analogous findings in cattle, we inferred that there is potential for venereal transmission of leptospirosis in small ruminants. (c) 2008 Elsevier Inc. All rights reserved.