SKELETAL MUSCLE SENSITIVITY TO WASTING INDUCED BY UROTHELIAL CARCINOMA

BACKGROUND

Skeletal muscle wasting is a common phenotypic feature of several types of cancer, and it is associated with functional impairment, respiratory complications, and fatigue. However, equivocal evidence remains regarding the impact of cancer-induced muscle wasting on the different fiber types.

AIM

The aim of this study was to investigate the impact of urothelial carcinoma induced in mice on the histomorphometric features and collagen deposition in different skeletal muscles.

MATERIALS AND METHODS

Thirteen ICR (CD1) male mice were randomly assigned into two groups: exposed to 0.05% N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in drinking water for 12 weeks, plus 8 weeks of tap water (BBN, n = 8) or with access to tap water for 20 weeks (CONT, n = 5). Tibialis anterior, soleus, and diaphragm muscles were collected from all animals. For cross-sectional area and myonuclear domain analysis, muscle sections were stained with hematoxylin and eosin, and for collagen deposition assessment, muscle sections were stained with picrosirius red.

RESULTS

All animals from the BBN group developed urothelial preneoplastic and neoplastic lesions, and the tibialis anterior from these animals presented a reduced cross-sectional area (p < 0.001), with a decreased proportion of fibers with a higher cross-sectional area, increased collagen deposition (p = 0.017), and higher myonuclear domain (p = 0.031). BBN mice also showed a higher myonuclear domain in the diaphragm (p = 0.015).

CONCLUSION

Urothelial carcinoma induced muscle wasting of the tibialis anterior, expressed by a decreased cross-sectional area, higher infiltration of fibrotic tissue, and increased myonuclear domain, which also increased in the diaphragm, suggesting that fast glycolytic muscle fibers are more susceptible to be affected by cancer development.

The influence of Castanea sativa Mill. flower extract on hormonally and chemically induced prostate cancer in a rat model

Prostate cancer (PCa) is one of the most common cancers in men, with a huge impact on their health. The use of Castanea sativa Mill. flowers (CFs) in beverages has been reported, through ancestral claims, as having health benefits. In vitro research has evidenced the properties of CFs, such as antitumor and antioxidant activities. This study aimed to evaluate the effects of CF extract in an animal model of PCa. Forty male Wistar Unilever rats were randomly assigned to four groups: control, induced, control + CF, and induced + CF groups. Animals from the induced groups were exposed to a multistep protocol for PCa induction. The CF extract, rich in trigalloyl-HHDP-glucoside and obtained via decoction, was administered to the CF groups in drinking water (3 mg per animal per day) for 49 weeks. Animals were sacrificed at 61 weeks of age. Regarding the effects of CFs on dorsolateral prostate tumorigenesis, no significant differences were observed between the induced and induced + CF groups. However, animals exposed to the CF extract showed fewer inflammation areas on the dorsolateral prostate lobe than those not exposed to CF. Moreover, the CF extract alleviated the hepatic oxidative stress associated with the multistep protocol, resulting in lower levels of lipid peroxidation. These results suggest that CF extract has antioxidant and anti-inflammatory properties.

P53 in skin cancer: From a master player to a privileged target for prevention and therapy

The increasing incidence of skin cancer (SC) is a global health concern. The commonly reported side effects and resistance mechanisms have imposed the pursuit for new therapeutic alternatives. Moreover, additional preventive strategies should be adopted to strengthen prevention and reduce the rising number of newly SC cases. This review provides relevant insights on the role of p53 tumour suppressor protein in melanoma and non-melanoma skin carcinogenesis, also highlighting the therapeutic potential of p53-targeting drugs against SC. In fact, several evidences are provided demonstrating the encouraging outcomes achieved with p53-activating drugs, alone and in combination with currently available therapies in SC. Another pertinent perspective falls on targeting p53 mutations, as molecular signatures in premature phases of photocarcinogenesis, in future SC preventive approaches. Overall, this review affords a critical and timely discussion of relevant issues related to SC prevention and therapy. Importantly, it paves the way to future studies that may boost the clinical translation of p53-activating agents, making them new effective alternatives in precision medicine of SC therapy and prevention.

Representations of adolescents on HIV/AIDS with a focus on sexuality and vulnerability to infections

Background

The highest increase in AIDS cases in Brazil is among 15-24 years old. In the last eight years, there have been almost 30,000 new cases in this population group, which represents an average of 10 new cases per day. This chart highlights the importance of promoting health and prevention of sexually transmitted infections (STIs) and AIDS for this population group. The purpose of the present study is to understand representations of adolescents of both sexes on HIV/AIDS, focusing on sexuality and vulnerability to sexually transmitted infections.

Methods

This is a research with a qualitative approach based on the theory of Representations and included in the study 28 adolescents high school students of two state public schools. Data collection took place through open interviews, held individually at agreed times and locations between the researchers and the direction of the schools. The interviews were of the in-depth type, with a semi-structured script, containing questions that allowed the participant to narrate facts, express their points of view, value judgments, and evaluate actions and ways of thinking about sexuality, sexual health and risk of infection HIV and other STIs, yours and others.

Results

The data were interpreted based on the Structural Analysis of Narration, being grouped into two categories: Sexuality; Risks involved in sexual intercourse. This study highlighted the complexity that involves issues related to sexuality and adolescence, just as adolescents deal with the risks of becoming infected with an STI. There are differences between representations of sexual relations for adolescent females and males.

Conclusions

The representations of adolescents about sexuality and about HIV/AIDS prevention are structured more in their exchanges and experiences in the social space, with colleagues and friends, than in family institutions and in school. It is necessary that there be continuous actions and not only in specific periods.

Key messages

Understanding how adolescents experience sexuality can be the starting point for more effective health promotion actions for this population group. Since the beginning of the AIDS epidemic, there have been different ways of coping with this infection. Thus, it is important to know the representation of adolescents today about this theme.

Digital media and risks involved for the LGBT community

Background

With the increase in the use of the internet and digital media, the number of people looking to network digitally, or just to find someone to have romantic or sexual encounters, has also increased. For this, there are networks and applications that are used for the purpose of romantic and sexual encounters, such as Tinder, Happn, Badoo, Scruff, Grindr, among others. These types of networks currently allow and facilitate sexual contact, making it possible to arrange meetings only for the so-called casual sex, which can be defined as a kind of sexual experience that occurs without the need for a fixed relationship. With the possibility of the ease and practicality of being able to have a sexual relationship, attention should be paid to the vulnerability and risks that the social networks used for this purpose can place its users.

Objective

To understand how LGBT students deal with the use and risks involved in digital media.

Methods

This is a research with a qualitative approach, based on the Theory of Social Representations. University students who declared themselves as LGBT in the city of Belo Horizonte participated in the study. Data collection took place through open and in-depth interviews, with a semi-structured script. The data were interpreted based on the Structural Analysis of the Narration, proposed by Demazière; Dubar.

Results

Two theoretical categories were listed: Ease of contact with the use of social media - this category shows the ease that research participants have to show themselves, give opinions and demonstrate their interest in a person through digital media. Risks of using social media - Risks range from personal exposure, making an appointment with an unknown person, in addition to the risks related to sexually transmitted infections.

Conclusions

Users of digital media need to interpret the risks that are involved when accessing a social network and outline ways of taking care of themselves and others.

Key messages

Knowing ways that the LGBT community exposes itself in digital media can contribute to preventive actions and to promote the health of these people in a more effective way. With the ease of exchanging images and dating for casual sex, it is necessary to discuss new approaches to health, including by digital means.

Ways of exposing the sexuality of university students in digital media

Background

Due to social and technological developments, experiences related to relationships between people express changes, which can be observed in social media, especially in social networks and dating and sexual apps. The use of social networks is growing among people of all age groups, which facilitates the maintenance of interpersonal contact and allows some people to get to know each other digitally, in addition to assisting in the search for information about sexuality and making it possible to meet with women. loving or sexual purpose.

Objective

to understand the means that university students express their sexuality in digital media.

Methods

This is a research with a qualitative approach, based on the Theory of Social Representations. University students from Belo Horizonte participated in the study. Data collection took place through a structured questionnaire with open and closed questions made available via the internet. The data were interpreted based on the Structural Analysis of the Narration, proposed by Demazière; Dubar.

Results

Two theoretical categories were listed. Use of digital media for sexual and amorous encounters - university students reveal the use of apps for casual encounters, where they use photos considered sensual to get a date outside the digital medium. Use of digital media as a source of information - the research subjects say they use the internet as a source of information about sexuality, as they still consider this issue difficult to approach with parents. These students also share the acquired information and personal experiences with friends.

Conclusions

In the digital environment, social relations are based on a hypervisibility of personal life on social networks, where intimate, private and especially sexual and body issues are exposed.

Key messages

Understanding how university students express their sexuality in digital media is an important step towards promoting the health of this population group. Social media can be of great value, but it can also present risks. Thus, university students are susceptible to these two factors, especially when it comes to topics such as sexuality.

Influence of social media for sexuality of adolescents

Background

Adolescence is a phase of life of great emotional, cognitive, social and body changes. Also noteworthy are the changes related to the emotional relationship between young people and sexuality. Recent research indicates that the use of Social Media (MS) has increased dramatically among adolescents in the last 10 years, and they have a tendency to seek information on health, sexual health and STIs including AIDS in these media.

Objective

To understand the influences of social media for sexual health and sexuality in adolescents.

Methods

This is a research with a qualitative approach, based on the Theory of Social Representations. The study included 28 adolescents aged between 15 and 18 years old, high school students from two public schools in Belo Horizonte. Data collection took place through open and in-depth interviews, with a semi-structured script. The data were interpreted based on the Structural Analysis of the Narration, proposed by Demazière; Dubar.

Results

The results found point to positive and negative representations in relation to the interviewees' point of view on the influence of social media on the sexuality of these adolescents. The positive representations found revolve around the ease of access to information and the privacy of being able to search and answer your questions through the internet and other means of communication. The aforementioned negative representations point to the little media approach on the subject, in addition, they indicate sporadic approaches centered on festive periods and dates such as carnival, a unique focus on AIDS and aimed specifically at adult audiences.

Conclusions

It is necessary to rethink how adolescents and young people today experience their sexuality and how to reach them comprehensively, understanding the need to guarantee appropriate and quality information to adolescents.

Key messages

The present work leads to reflections on the ways that adolescents experience sexuality today. Currently, teenagers are involved in digital media, including social media, where they can express issues related to sexuality and the way they experience it.

HPV infection as a risk factor for atherosclerosis: A connecting hypothesis

Atheromatous plaques occurring in large arteries are common and life-threatening lesions. Multiple factors are involved in the pathogenesis of atheromatous plaques, such as hyperlipidaemia and hypercholesterolaemia, high blood pressure and chronic systemic inflammation. Recent findings have suggested that infection with high-risk human papillomavirus (HPV) may increase the risk of developing atheromatous plaques. However, HPV is considered a tissue-specific virus with a strong tropism towards squamous epithelial cells, and the mechanisms whereby it may promote the development of atheromas remain unclear. Here, we propose a connecting hypothesis to explain the possible causative role of HPV on atheroma development. We hypothesize that HPV infection may promote atheroma formation in infected patients by enhancing systemic inflammation or by directly targeting blood vessels via nucleic acids carried by extracellular vesicles such as exosomes. The pro-inflammatory effects of HPV and the release of extracellular vesicles by HPV-transformed cells are well documented in scientific literature. Possible experimental approaches to test this hypothesis are also discussed, especially experiments employing transgenic mice bearing HPV16 transgenes. If correct, this hypothesis would have major implications for the prevention of cardiovascular diseases, especially due to the preventable nature of HPV infection through vaccination.

Laurus nobilis (laurel) aqueous leaf extract's toxicological and anti-tumor activities in HPV16-transgenic mice

Cancers induced by human papillomavirus (HPV) infection remain a significant public health threat, fueling the study of new therapies. Laurel (Laurus nobilis) compounds and extracts recently showed in vitro activity against HPV-transformed cell lines. This work aims to evaluate the in vivo efficacy and hepatic toxicity of a laurel extract in a transgenic mouse model of HPV16-induced cancer. The extract was administered in drinking water (20 mg per animal per day) for three consecutive weeks, using four experimental groups (n = 10) (group I: HPV16-/- without treatment, group II: treated HPV16-/-, group III: HPV16+/- without treatment and group IV: treated HPV16+/-). Following the treatment period, animals were sacrificed and skin samples were used to classify skin lesions histologically. Toxicological parameters included hematological and biochemical blood markers, splenic and hepatic histology and hepatic oxidative stress. The extract did not prevent the progression of HPV16-induced cutaneous lesions in this model. The treated wild-type animals showed mild hepatitis, while transgenic animals suffered weight loss. However, there were no changes concerning hematological, biochemical and hepatic oxidative stress markers.

Ozone therapy prevents the onset of dysplasia in HPV16-transgenic mice-A pre-clinical efficacy and safety analysis

Infection with high-risk human papillomavirus (HPV), most often HPV16, is associated with the development of anogenital and oropharyngeal cancers. Recently, ozone therapy was reported to have considerable efficacy against rabbit VX2 tumors, induced by the cottontail rabbit papillomavirus. The present study aims to determine whether similar results can be obtained in HPV16-transgenic mice, possibly paving the way for new therapeutic options against HPV-induced cancers. HPV16-transgenic and wild-type, female, 20 weeks-old mice were injected intraperitoneally with medical O₃/O₂ (80░mL/kg, at O₃ 50░μg/mL), once a day, for 5 consecutive days. The animals were sacrificed at 25 weeks-old, and skin samples were analyzed histologically to study tumour progression. Blood and internal organ samples were used to study toxicological parameters. 85.7% of untreated transgenic mice showed dysplastic skin lesions, compared with 28.6% of O₃-treated mice. This was associated with a marked reduction of dermal inflammation associated with those lesions. No significant changes were observed in any toxicological parameters. These preliminary results support the hypothesis that O₃ therapy is effective against papillomavirus-induced lesions, particularly against those induced by the most common high-risk virus, HPV16. Further studies are needed to confirm the mechanisms underlying these effects.

Long-term exercise training prevents mammary tumorigenesis-induced muscle wasting in rats through the regulation of TWEAK signalling

AIM

Exercise training has been suggested as a non-pharmacological approach to prevent skeletal muscle wasting and improve muscle function in cancer cachexia. However, little is known about the molecular mechanisms underlying such beneficial effect. In this study, we aimed to, firstly, examine the contribution of TWEAK signalling to cancer-induced skeletal muscle wasting and, secondly, evaluate whether long-term exercise alters TWEAK signalling and prevents muscle wasting.

METHODS

Female Sprague-Dawley rats were randomly assigned to control and exercise groups. Fifteen animals from each group were exposed to N-Methyl-N-nitrosourea carcinogen. Animals in exercise groups were submitted to moderate treadmill exercise for 35 weeks. After the experimental period, animals were killed and gastrocnemius muscles were harvested for morphological and biochemical analysis.

RESULTS

We verified that exercise training prevented tumour-induced TWEAK/NF-κB signalling in skeletal muscle with a beneficial impact in fibre cross-sectional area and metabolism. Indeed, 35 weeks of exercise training promoted the upregulation of PGC-1α and oxidative phosphorylation complexes. This exercise-induced muscle remodelling in tumour-bearing animals was associated with less malignant mammary lesions.

CONCLUSION

Data support the benefits of an active lifestyle for the prevention of muscle wasting secondary to breast cancer, highlighting TWEAK/NF- κB signalling as a potential therapeutic target for the preservation of muscle mass.

Intake, digestibility, performance, and nitrogen metabolism of feedlot-finished young bulls () fed diets containing peanut cake

This aim of this study was to evaluate the use of peanut cake as a dietary substitute for soybean meal and to determine the effects on intake, apparent digestibility, performance, and N metabolism in feedlot-finished young bulls. Thirty-two young Nellore bulls with an average initial BW of 390 ± 43.5 kg were distributed in a completely randomized design and individually housed in stalls. The young bulls were fed Tifton 85 hay and 4 concentrate mixes containing 0, 33, 66, or 100% peanut cake replacing soybean meal. The diets were formulated to be isonitrogenous, containing 150 g/kg CP, and isocaloric (65% TDN), to have a 40:60 forage:concentrate ratio, and were provided as a total mixed ration. The experiment lasted 90 d and data were collected every 28 d. Blood and urine samples were taken during the last 6 d. Intakes of DM ( = 0.005), OM ( = 0.006), CP ( = 0.002), NDF ( = 0.022), nonfiber carbohydrates ( = 0.002), and TDN ( = 0.018) linearly decreased as the dietary inclusion of peanut cake in the diet was increased. Conversely, intake and ether extract digestibility linearly increased ( < 0.035). The average daily weight gain decreased ( = 0.015) as the peanut cake levels were increased. Plasma urea N decreased (linearly; = 0.005). Peanut cake may not be used to replace soybean meal in the diet of young feedlot-finished Nellore bulls.

Trihalomethanes in liver pathology: Mitochondrial dysfunction and oxidative stress in the mouse

Trihalomethanes (THMs) are disinfection byproducts found in chlorinated water, and are associated with several different kinds of cancer in human populations and experimental animal models. Metabolism of THMs proceeds through enzymes such as GSTT1 and CYP2E1 and gives rise to reactive intermediates, which form the basis for their toxic activities. The aim of this study was to assess the mitochondrial dysfunction caused by THMs at low levels, and the resulting hepatic histological and biochemical changes in the mouse. Male ICR mice were administered with two THMs: dibromochloromethane (DBCM) and bromodichloromethane (BDCM); once daily, by gavage, to a total of four administrations. Animals were sacrificed four weeks after DBCM and BDCM administrations. Blood biochemistry was performed for alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TB), albumin (Alb), total protein (TP), creatinine, and urea. Animals exposed to DBCM and BDCM showed elevated ALT and TB levels (p < 0.05) as compared with controls. Histological analysis confirmed the presence of vacuolar degenerescence and a multifocal necrotizing hepatitis in 33% of animals (n = 2). Mitochondrial analysis showed that THMs reduced mitochondrial bioenergetic activity (succinate dehydrogenase (SQR), cytochrome c oxidase (COX), and ATP synthase) and increased oxidative stress (glutathione S-transferase (GST)) in hepatic tissues (p < 0.05). These results add detail to the current understanding of the mechanisms underlying THM-induced toxicity, supporting the role of mitochondrial dysfunction and oxidative stress in liver toxicity caused by DBCM and BDCM. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1009-1016, 2016.

mTOR inhibitors in urinary bladder cancer

Despite the great scientific advances that have been made in cancer treatment, there is still much to do, particularly with regard to urinary bladder cancer. Some of the drugs used in urinary bladder cancer treatment have been in use for more than 30 years and show reduced effectiveness and high recurrence rates. There have been several attempts to find new and more effective drugs, to be used alone or in combination with the drugs already in use, in order to overcome this situation.The biologically important mammalian target of rapamycin (mTOR) pathway is altered in cancer and mTOR inhibitors have raised many expectations as potentially important anticancer drugs. In this article, the authors will review the mTOR pathway and present their experiences of the use of some mTOR inhibitors, sirolimus, everolimus and temsirolimus, in isolation and in conjunction with non-mTOR inhibitors cisplatin and gemcitabine, on urinary bladder tumour cell lines. The non-muscle-invasive cell line, 5637, is the only one that exhibits a small alteration in the mTOR and AKT phosphorylation after rapalogs exposure. Also, there was a small inhibition of cell proliferation. With gemcitabine plus everolimus or temsirolimus, the results were encouraging as a more effective response was noticed with both combinations, especially in the 5637 and T24 cell lines. Cisplatin associated with everolimus or temsirolimus also gave promising results, as an antiproliferative effect was observed when the drugs were associated, in particular on the 5637 and HT1376 cell lines. Everolimus or temsirolimus in conjunction with gemcitabine or cisplatin could have an important role to play in urinary bladder cancer treatment, depending on the tumour grading.

Long-term exercise training as a modulator of mammary cancer vascularization

BACKGROUND

Breast cancer remains a leading cause of death by cancer worldwide. It is commonly accepted that angiogenesis and the expression of angiogenic factors such as vascular endothelial growth factor-A (VEGF-A) is associated with the increased risk of metastasis and poor patient outcome.

OBJECTIVE

This work aimed to evaluate the effects of long-term exercise training on the growth and vascularization of mammary tumors in a rat model.

MATERIALS AND METHODS

Fifty female Sprague-Dawley rats were divided into four groups: two N-methyl-N-nitrosourea (MNU)-exposed groups (exercised and sedentary) and two control groups (exercised and sedentary). MNU was administered once, intraperitoneally at 7 weeks-old. Animals were then exercised on a treadmill for 35 weeks. Mammary tumors were evaluated using thermography, ultrasonography [Power Doppler (PDI), B Flow and contrast-enhanced ultrasound (CEUS)], and immunohistochemistry (VEGF-A).

RESULTS

Both, MNU sedentary and exercised groups showed 100% of tumor incidence, but exercised animals showed less tumors with an increased latency period. Exercise training also enhanced VEGF-A immunoexpression and vascularization (microvessel density, MVD) (p<0.05), and reduced histological aggressiveness. Ultrasound and thermal imaging analysis confirmed the enhanced vascularization of tumors on exercised animals.

CONCLUSION

Long-term exercise training increased VEGF-A expression, leading to enhanced tumor vascularization and reduced tumor burden, multiplicity and histological aggressiveness.

Innovative methodology for intercomparison of radionuclide calibrators using short half-life in situ prepared radioactive sources

PURPOSE

An original radionuclide calibrator method for activity determination is presented. The method could be used for intercomparison surveys for short half-life radioactive sources used in Nuclear Medicine, such as(99m)Tc or most positron emission tomography radiopharmaceuticals.

METHODS

By evaluation of the resulting net optical density (netOD) using a standardized scanning method of irradiated Gafchromic XRQA2 film, a comparison of the netOD measurement with a previously determined calibration curve can be made and the difference between the tested radionuclide calibrator and a radionuclide calibrator used as reference device can be calculated. To estimate the total expected measurement uncertainties, a careful analysis of the methodology, for the case of(99m)Tc, was performed: reproducibility determination, scanning conditions, and possible fadeout effects. Since every factor of the activity measurement procedure can influence the final result, the method also evaluates correct syringe positioning inside the radionuclide calibrator.

RESULTS

As an alternative to using a calibrated source sent to the surveyed site, which requires a relatively long half-life of the nuclide, or sending a portable calibrated radionuclide calibrator, the proposed method uses a source preparedin situ. An indirect activity determination is achieved by the irradiation of a radiochromic film using (99m)Tc under strictly controlled conditions, and cumulated activity calculation from the initial activity and total irradiation time. The irradiated Gafchromic film and the irradiator, without the source, can then be sent to a National Metrology Institute for evaluation of the results.

CONCLUSIONS

The methodology described in this paper showed to have a good potential for accurate (3%) radionuclide calibrators intercomparison studies for(99m)Tc between Nuclear Medicine centers without source transfer and can easily be adapted to other short half-life radionuclides.

E-cadherin and β-catenin expression during urothelial carcinogenesis induced by N-butyl-N-(4-hydroxybutyl) nitrosamine in mice

BACKGROUND

E-cadherin and β-catenin are adhesion molecules that promote integrity and stability of the urothelium. A decrease in their expression is associated with more aggressive tumour phenotypes with the ability to invade and metastasize.

MATERIAL AND METHODS

45 ICR male mice were used, of which 25 received N-butyl-N-(4-hydroxybutyl)nitrosamine (0.05%) in drinking water for a period of 12 weeks. Immunohistochemical expression was evaluated in all urinary bladder preparations for E-cadherin and for β-catenin.

RESULTS

Preneoplastic lesions showed staining patterns similar to normal urothelium. In simple and nodular hyperplasia, membrane staining was dominant (66.7-78.6 and 50-100%, respectively). In dysplasia a cytoplasmic pattern was prevalent (86.7-100%). Neoplastic lesions exhibit an abnormal staining pattern (100%) with heterogeneous staining (cytoplasmic, nuclear and membrane staining). A strong correlation was observed between both adhesion molecule staining patterns (r = 0.83; p = 0.039).

CONCLUSIONS

In mice, as in humans, E-cadherin and β-catenin are valuable tools to investigate cellular adhesion status of urothelium and can be considered as indicators of tumour aggressiveness and evolution.

Review: BBN as an urothelial carcinogen

Experimental urinary bladder tumours have been proposed as a useful model for the study of urinary bladder carcinogenesis, as well as for evaluating new therapeutic strategies. Consequently, the administration of chemical carcinogens is one of the most commonly used methods for inducing urinary bladder tumours. N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) is, undoubtedly, the most-used urothelial chemical carcinogen. BBN belongs to the nitrosamine family, a wide group of alkylating agents that are able to induce bladder tumours in laboratory animals. Depending on the animal species, the spectrum of urothelial lesions induced by BBN varies, but is similar to those observed in humans. BBN has a high propensity to induce mutations affecting the expression of genes such as p53, RAS and H19 among others. The aim of this study was to review BBN as a urothelial tumour inducer, taking into consideration its chemical characteristics, properties and spectrum of lesions induced, as well as its possible applications.

Bracken-associated human and animal health hazards: chemical, biological and pathological evidence

Bracken (Pteridium aquilinum) is a widely distributed carcinogenic fern, to whose toxins human populations are exposed through multiple routes. Animals are also affected by bracken toxins, leading to serious production losses yearly. Accordingly, several governmental reports regarding the safeguard of public health against bracken carcinogens have been recently issued. This review describes the main bioactive compounds identified in bracken and their biological effects at the molecular, cellular, pathological and populational levels, with particular emphasis on ptaquiloside, the main bracken carcinogen. Recent biopathological studies shedding further light on the genotoxicity immunotoxicity and carcinogenicity of ptaquiloside are discussed. Key steps on the long effort to understand bracken toxicology are also reviewed, along with the latest findings on new bracken toxins and human exposures routes. The presence of ptaquiloside and related terpene glycosides in milk, meat and water are of particular concern from the viewpoints of both human and animal health.

Cell activation state influences the modulation of HLA-DR surface expression on human monocytes/macrophages by parenteral fish oil lipid emulsion

Abnormal surface expression of HLA-DR by leukocytes is associated with a poor prognosis in critical care patients. Critical care patients often receive total parenteral nutrition with lipid emulsion (LE). In this study we evaluated the influence of fish oil LE (FO) on human monocyte/macrophage (Mφ) expression of surface HLA-DR under distinct activation states. Mononuclear leukocytes from the peripheral blood of healthy volunteers (n=18) were cultured for 24 hours without LE (control) or with 3 different concentrations (0.1, 0.25, and 0.5%) of the follow LE: a) pure FO b) FO in association (1:1-v/v) with LE composed of 50% medium-chain trygliceride and 50% soybean oil (MCTSO), and c) pure MCTSO. The leukocytes were also submitted to different cell activation states, as determinate by addition time: no INF-γ addition, 18 hours before, or at the time of LE addition. HLA-DR expression on Mφ surface was evaluated by flow cytometry using specific monoclonal antibodies. In relation to controls (for 0.1%, 0.25%, and 0.5%: 100) FO decreased the expression of HLA-DR when added alone [in simultaneously-activated Mφ, for 0.1%: 70 (59 ± 73); for 0.25%: 51 (48 ± 56); and for 0.5%: 52.5 (50 ± 58)] or in association with MCTSO [in simultaneously-activated Mφ, for 0.1%: 50.5 (47 ± 61); for 25%: 49 (45 ± 52); and for 0.5%: 51 (44 ± 54) and in previously-activated Mf, for 1.0%: 63 (44 ± 88); for 0.25%: 70 (41 ± 88); and for 0.5%: 59.5 (39 ± 79)] in culture medium (Friedman p < 0.05). In relation to controls (for 0.1%, 0.25%, and 0.5%: 100), FO did not influence the expression of these molecules on non-activated Mφ [for 0.1%: 87.5 (75±93); for 0.25%: 111 (98 ± 118); and for 0.5%: 101.5 (84 ± 113)]. Results show that parenteral FO modulates the expression of HLA-DR on human Mφ surface accordingly to leukocyte activation state. Further clinical studies evaluating the ideal moment of fish oil LE infusion to modulate leukocyte functions may contribute to a better understanding of its immune modulatory properties.

Experimental study of the anticancer effect of gemcitabine combined with sirolimus on chemically induced urothelial lesions

BACKGROUND

The purpose of this study was to determine the efficacy of a combination of gemcitabine and sirolimus in a mouse model of invasive bladder cancer.

MATERIALS AND METHODS

Gemcitabine (50 mg/kg) and sirolimus (1.5 mg/kg) were administered to animals previously exposed to N-butyl-N-4(hydroxybutyl)nitrosamine in drinking water. Tumour development was determined by histopathological evaluation.

RESULTS

Both drugs were well tolerated by animals. The incidence of lesions in mice treated with gemcitabine was lower in comparison to those not treated, however this result was not statistically significant. The incidence of invasive bladder cancer in animals treated with sirolimus was statistically lower (20%) than in animals not treated (54%) (p=0.008). The results indicate that this drug combination has no statistical significance on the development of pre-neoplastic urothelial lesions and had only a minor impact on invasive bladder cancer incidence in mice.

CONCLUSION

The combination of gemcitabine and sirolimus had only a marginal impact on invasive bladder cancer in a mouse model.

Comportamento ingestivo e parâmetros fisológicos de novilhos alimentados com tortas do biodiesel

Com o objetivo de avaliar o potencial de tortas oriundas da produção de biodiesel (dendê, amendoim e girassol) em substituição ao farelo de soja, avaliou-se o comportamento ingestivo e parâmetros fisiológicos de novilhos Holandês x Zebu submetidos a dietas contendo estes subprodutos. Foram utilizados quatro novilhos Holandês x Zebu, fistulados no rúmen, mantidos em baias individuais e dispostos em um quadrado latino 4 x 4 repetido no tempo. O experimento teve duração de 88 dias e os animais foram alimentados com feno de Tifton-85 e mistura concentrada com farelo de soja, tortas de dendê, amendoim e girassol, que constituíram os quatro tratamentos. O comportamento ingestivo foi avaliado por observação e registro dos tempos diários despendidos com alimentação, ruminação e ócio. O comportamento bioclimatológico dos animais foi avaliado por intermédio das seguintes medições: frequência respiratória (FR), frequência cardíaca (FC) e temperatura retal (TR). Não houve diferença entre as dietas para o tempo despendido tanto na ingestão, como na ruminação (p>0,05), entretanto, os animais que consumiram a dieta com torta de dendê despenderam mais tempo em ócio (p

Genotyping in the Brazilian Criollo Horse Stud Book: resources and perspectives

The goal of this research was to evaluate the ability of the genotyping information available in the Brazilian Criollo Horse Stud Book to describe the genetic variability of the breed and the exclusion probability determined in comparative tests. Altogether, two softwares were used in the analyses of the available genotypes: Cervus 3.0.3 and Genepop 4.0. Eight microsatellite markers totaled 109 alleles, with an average of 13.6 +/- 0.6 alleles per locus. Large differences between expected and observed heterozygosity were ubiquitous (0.821 +/- 0.07 and 0.470 +/- 0.17, respectively). Although the estimated null allele frequency caused initial concern (0.284 +/- 0.199), it is likely that it was a reflection of the inbreeding coefficients found (0.432 +/- 0.184). All loci showed significant deviation from Hardy-Weinberg equilibrium, with heterozygote deficit (P < 0.0001) and genotypic linkage disequilibrium with at least one marker. The high polymorphic information content (0.798 +/- 0.088) could not warrant exclusion power for three loci (HMS7, HMS6 and HTG4) above 50% (0.491 +/- 0.158). However, combined exclusion probability reached 99.61%, a level close to ideal. The results demonstrate the excellent performance of the markers assessed in describing the genetic status of the breed and suggest the considerable ability to establish parentage.

Cell activation state influences the modulation of HLA-DR surface expression on human monocytes/macrophages by parenteral fish oil lipid emulsion

Abnormal surface expression of HLA-DR by leukocytes is associated with a poor prognosis in critical care patients. Critical care patients often receive total parenteral nutrition with lipid emulsion (LE). In this study we evaluated the influence of fish oil LE (FO) on human monocyte/macrophage (Mphi) expression of surface HLA-DR under distinct activation states. Mononuclear leukocytes from the peripheral blood of healthy volunteers (n=18) were cultured for 24 hours without LE (control) or with 3 different concentrations (0.1, 0.25, and 0.5%) of the follow LE: a) pure FO b) FO in association (1:1-v/v) with LE composed of 50% medium chain triglyceride and 50% soybean oil (MCTSO), and c) pure MCTSO. The leukocytes were also submitted to different cell activation states, as determinate by INF-gamma addition time: no INF-gamma addition, 18 hours before, or at the time of LE addition. HLA-DR expression on Mphi surface was evaluated by flow cytometry using specific monoclonal antibodies. In relation to controls (for 0.1%, 0.25%, and 0.5%: 100) FO decreased the expression of HLA-DR when added alone [in simultaneously-activated Mphi, for 0.1%: 70 (59+/-73); for 0.25%: 51 (48+/-56); and for 0.5%: 52.5 (50+/-58)] or in association with MCTSO [in simultaneously-activated Mphi, for 0.1%: 50.5 (47+/-61); for 25%: 49 (45+/-52); and for 0.5%: 51 (44+/-54) and in previously-activated Mphi, for 1.0%: 63 (44+/-88); for 0.25%: 70 (41+/-88); and for 0.5%: 59.5 (39+/-79)] in culture medium (Friedman p<0.05). In relation to controls (for 0.1%, 0.25%, and 0.5%: 100), FO did not influence the expression of these molecules on non-activated Mphi [for 0.1%: 87.5 (75+/-93); for 0.25%: 111 (98+/-118); and for 0.5%: 101.5 (84+/-113)]. Results show that parenteral FO modulates the expression of HLA-DR on human Mphi surface accordingly to leukocyte activation state. Further clinical studies evaluating the ideal moment of fish oil LE infusion to modulate leukocyte functions may contribute to a better understanding of its immune modulatory properties.

DNA cytometry and kinetics of rat urothelial lesions during chemical carcinogenesis

The aims of this study were to evaluate the DNA content of chemically-induced rat urothelial lesions and their relationship to the proliferation index and histological patterns. Sixty female Fisher 344 rats were divided randomly into six groups, four groups were exposed to N-butyl-N-(4-hydroxybutyl) nitrosamine for a period of 10 and 20 weeks, and two groups of ten rats were used as control animals. Paraffin sections were Feulgen stained and analyzed using DNA image cytometry analysis; histograms were classified as either diploid or aneuploid. Ki-67 immunoreactivity was determined by means of the streptavidin-biotin-complex immunoperoxidase method. All normal urothelium from the control groups were found to have diploid DNA content. The same histogram pattern was found in the simple hyperplasia group. As regards the other histological lesions, the frequency of the aneuploidy varied depending on the lesion type: 20% of aneuploidy were nodular hyperplasia, 32% of aneuploidy were dysplasias, 25% of aneuploidy were papilloma, 44% of aneuploidy were papillary neoplasm of low malignant potential, 22% of aneuploidy were low-grade papillary carcinoma, 100% of aneuploidy were high-grade papillary carcinoma and 100% of the aneuploidy were invasive carcinoma. Our results revealed the existence of a statistically significant relationship between DNA ploidy and histological pattern lesions (r=0.3, p<0.023). The Ki-67 proliferation index was significantly higher in aneuploid lesions than in diploid (r=0.56, p=0.01). There was also a statistically significant difference in the Ki-67 proliferation index in relation to the histopathological pattern (r=0.751, p<0.01). DNA content was associated with the Ki-67 proliferation index and histopathological grade. DNA content and prolife-ration index have critical roles to play during urothelial carcinogenesis.

A phyllodes tumor of the urinary bladder in a rat

AIM

The aim of this short communication was to describe a case of phyllodes tumor of the urinary bladder discovered in a female Fisher 344 rat that died during an experimental protocol to induce and study urothelial lesions by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN).

METHODOLOGY

From a group of several female rats exposed to BBN via drinking water over the course of 20 weeks, one animal died. At necropsy, a solid mass was identified in the urinary bladder lumen, with a diameter of 0.8 x 0.7 cm. This tumor was processed for histopathological examination and Feulgen coloration.

RESULTS

Microscopically, the mass in the bladder was observed to be a phyllodes tumor. DNA content measured by image analysis of a Feulgen-stained section of the tumor and stroma cells displayed diploid DNA content in both components of the tumor.

CONCLUSION

This is the first reported phyllodes tumor in a rat's urinary bladder. The exact prognosis and histogenesis of phyllodes tumors of the urinary bladder remains to be determined by the accumulation of data from additional cases.

E-cadherin expression during urothelial carcinogenesis induced by N-butyl-N-(4-hydroxybutyl) nitrosamine in rats

An alteration in the expression of E-cadherin has been observed in many epithelial neoplasms. No data exist, however, for the expression of this protein in an animal model for urinary bladder cancer. The present study investigated the expression of E-cadherin in rat urothelial preneoplastic lesions and tumours induced by oral administration of N-butyl-N-(4-hydroxybutyl) nitrosamine, during 10, 15 and 20 weeks. Simple hyperplasia and squamous metaplasia showed a similar E-cadherin pattern when compared with normal urothelium, with its expression confined to cell membrane. Thirty eight percent of the nodular hyperplasia, 41.4% of the dysplasia and 100% of the papillomas showed a weak E-cadherin expression. All papillary neoplasm of low malignant potential, low-and high-grade papillary carcinoma, and invasive carcinoma revealed an abnormal staining pattern with an increase in cytoplasm reactivity and discontinuous cell membrane positivity. The loss of expression for low-grade papillary carcinoma versus simple hyperplasia, nodular hyperplasia and dysplasia was statistically significant (p = 0.0001, p = 0.007 and p=0.008, respectively). There was a similar decrease in E-cadherin expression for papillary neoplasm of low malignant potential versus simple hyperplasia, nodular hyperplasia and dysplasia (p = 0.0001; p = 0.001 and p=0.0001, respectively). These results suggest that alteration in the expression of this adhesion molecule in rat may be indicative of tumour progression in N-butyl-N-(4-hydroxybutyl) nitrosamine-induced bladder cancer.

Experimental bladder carcinogenesis-rodent models

Several rodent models of bladder cancer development have been established. The aim of this review article is to provide a critical assessment of different animal models available for the study of bladder carcinogenesis, its chemoprevention and therapy. All, except for transgenic and knockout animals, require 8-12 months experimental periods in order to generate a high yield of neoplasias. Spontaneous bladder tumor models are extremely rare. The significance of the results from animal experiments is dependent upon the selection of a suitable animal model. There are no rules regarding the choice of a model, it is however very useful to have knowledge of relevant comparative medical aspects concerning this subject. We describe chemical carcinogens most commonly used to induce bladder cancer, pellet implantation and urinary calculi, agents that promote bladder cancer, and irradiation. We also evaluated other tools such as cell cultures, tumor implantation and transgenic models for bladder cancer, that have been developed to study the process. The review considers how several imaging techniques can be applied to study rodent bladder carcinogenesis.

Evaluation of DNA content in preneoplastic changes of mouse urinary bladder induced by N-butyl-N-(4-hydroxybutyl) nitrosamine

Using image cytometry analysis we analysed the deoxyribonucleic acid content of preneoplastic lesions induced in C3H/He female mice. Female mice (n = 30) were given 0.05% BBN in their drinking water for 4, 8 and 12 weeks, and were then euthanized. At the 4th week 90% hyperplasias, 90% dysplasias and 10% papillary tumours developed selectively in the bladder, after 8 weeks mice developed 80% hyperplasias and 80% dysplasias and 12 weeks we identified 70% hyperplasias, 70% dysplasias, 10% papillary tumours and 20% squamous metaplasia. Among the ones who developed simple hyperplasia, 58.3% were diploid and 41.7% were aneuploid. In the dysplasia lesions 29.2% were diploid and 70.8% were aneuploid (p = 0.041). All papillary tumours were aneuploid and all epidermoid metaplasias were diploid. These results suggest that aneuploidization, DNA content alteration of preneoplastic lesions, might be considered as a prognostic factor.

Cyclooxygenase inhibition reduces blood pressure elevation and vascular reactivity dysfunction caused by inhibition of nitric oxide synthase in rats

In the present study we investigated the role of cyclooxygenase (COX)-dependent vasoconstrictors in the hypertension and altered vascular reactivity following prolonged nitric oxide (NO) synthase inhibition. Male Wistar rats (250-270 g) were divided into four groups and treated for 7 days with Placebo (control), L-NAME (48 mg/kg/day), indomethacin (4 mg/kg/day) and L-NAME in combination with indomethacin. L-NAME treatment induced arterial hypertension, in vitro aortic hyperresponsiveness to phenylephrine, impaired vasodilatory response to acetylcholine and no significant change in response to sodium nitroprusside. Indomethacin co-treatment partially prevented blood pressure elevation, restored responsiveness to phenylephrine and improved sensitivity to acetylcholine. Indomethacin treatment alone did not modify blood pressure and aortic vascular reactivity. Both enhanced phenylphrine-induced contraction and impaired acetylcholine-evoked vasodilation induced by acute NO synthase inhibition with L-NAME (10(-4) M) in normal rat aortas were not modified by indomethacin (10(-5) M). These results are consistent with the hypothesis that constricting factors, which arise from the COX pathway, contribute to hypertension and altered vascular reactivity following continued inhibition of NO synthase.