Cytogenetic damage in circulating lymphocytes and buccal mucosa cells of head-and-neck cancer patients undergoing radiotherapy

This study evaluated cytogenetic damage by measuring the frequency of micronucleated cells (MNC) in peripheral blood and buccal mucosa of head-and-neck cancer patients undergoing radiotherapy.MNC frequencies were assessed in 31 patients before, during, and after radiotherapy, and in 17 C, healthy controls matched for gender, age, and smoking habits. Results showed no statistically significant difference between patients and controls prior to radiotherapy in cytokinesis-blocked lymphocytes or buccal mucosa cells. During treatment, increased MNC frequencies were observed in both cell types. Micronucleated lymphocyte levels remained high in samples collected 30 to 140 days after the end of treatment, while MNC frequency in buccal mucosa decreased to values statistically similar to baseline values. There is controversy over the effects of age, smoking habit, tumor stage, and/or metastasis on MNC frequency. However, increased frequency of micronucleated buccal mucosa cells was seen in patients under 60 years old and in those with tumors >4cm.In conclusion, the data show that radiotherapy has a potent clastogenic effect in Circulating lymphocytes and buccal mucosa cells of head-and-neck cancer patients, and that the baseline MNC frequency in these two tissues is not a sensitive marker for head-and neck neoplasm.

Antigen otoxicity of Agaricus blazei mushroom organic and aqueous extracts in chromosomal aberration and cytokinesis block micronucleus assays in CHO-k1 and HTC cells

Agaricus blazei (Ab) has become popularly known for its medicinal properties. Scientifically, it has been tested with regard to its capacity to protect genetic material against damage. We examined different organic extracts (methanolic extract-ME, hexanic extract-HE and n-butanolic extract-BE) and an aqueous extract (AE) of Ab, for their capacity to induce DNA damage as well as for their protective effect. Genetic damage was determined by the chromosomal aberration assay (CA) in CHO-k1 cells for all extracts and the cytokinesis block micronucleus assay (CBMN) in non drug-metabolizing (CHO-k1) and drug-metabolizing (HTC) cell lines for extract BE only. The extracts did not show clastogenicity but showed anticlastogenicity. The greatest percent reduction obtained were with BE (105%) and AE (126%) treatments in CA. BE treatment did not display genotoxicity in CHO-k1, but was genotoxic in HTC. However, BE was shown to be antigenotoxic causing decreased micronucleus frequency in HTC and CHO-k1 cells. These results suggest that all the extracts contained protective substances, but in some cases they could show a genotoxic effect with regard to metabolism. Therefore, these findings warrant caution in the use of this mushroom by the population. (c) 2005 Elsevier Ltd. All rights reserved.

The central repeat domain 1 of Kaposi's sarcoma-associated herpesvirus (KSHV) latency associated-nuclear antigen 1 (LANA1) prevents cis MHC class I peptide presentation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Frequency of human leukocyte antigen (hla) in patients with malaria and in the general population of Humaitá county, Amazonas state, Brazil

Em agosto de 1983 foram observados 85 habitantes do Município de Humaitá, Estado do Amazonas, Brasil, com a finalidade de estudar a prevalência dos antígenos de HLA -A, -B, -C e DR, dentre os quais 38 eram doentes com malária causada pelo Plasmodium falciparum Todos eles foram examinados para avaliação de esplenomegalia, exame parasitológico de sangue e pesquisa de anticorpos de malária. Foram constituídos três grupos: (I) 25 indivíduos nascidos na região Amazônica que nunca tiveram malária; (II) 38 indivíduos naturais da Amazônia que tinham sido tratados de malária no passado, ou que estavam tendo malária atual, e (III) 22 doentes com malária que contraíram na Amazônia e eram procedentes de outras regiões do Brasil. Foram colhidas amostras de sangue de cada um deles, separados os linfôcitos e os antígenos de HLA foram tipados pelo teste de microlinfocitotoxidade. Houve elevada freqüência de antígenos não identificados, nos grupos estudados, o que sugere ou a existência de homozigoze, oufenôtipo não identificado nessa população. Houve alta freqüência fenotípica de antígeno deAg(W24) (44,7%) no Grupo II, quando comparado ao Grupo 1(32%) ou Grupo III (9%). Os indivíduos do Grupo II mostraram também elevada freqüência do antígeno DR4 (80%) quando comparado ao Grupo 1(36,3%) ou Grupo III(16,6%). Essas observações sugerem a possibilidade de suscetibilidadegenética ã malária entre os nativos da Amazônia e indicam a necessidade da realização de inquéritos mais extensos sobre a freqüência de antígenos de HLA em habitantes de zona endêmica de malária.

Flow cytometric assessment of canine erythrocytes and platelets for dog erythrocyte antigen 1.1

Background: In human medicine, transfusion of ABO-mismatched platelets has been associated with shortened platelet survival and refractoriness to platelet transfusion because of expression of certain blood group antigens on platelets. It remains unknown if canine platelets express dog erythrocyte antigens (DEAs). Objective: The aim of this study was to develop a flow cytometric assay for DEA 1.1 and determine whether DEA 1.1 is present on canine platelets.Methods: Blood was collected from 172 clinically healthy dogs. Platelets and erythrocytes from each dog were tested for DEA 1.1 by flow cytometry using anti-DEA 1.1 blood-typing sera. Erythrocytes from each dog were also assessed for DEA 1.1 using a standard tube-typing test (T1) and using a second tube method (T2), if the flow cytometric and T1 results differed.Results: Using flow cytometry, DEA 1.1 was detected on erythrocytes of all 110 dogs shown by T1 or T2 testing to be DEA 1.1-positive. Initial results of the T1 test had a diagnostic accuracy of 93% (160 correct/ 172 tests). The frequency of erythrocyte DEA 1.1 positivity in previously untyped dogs (n = 118) was 56%. DEA 1.1 expression was not detected on platelets from DEA 1.1-positive dogs.Conclusions: Flow cytometry was a reliable method for detection of DEA 1.1 on canine erythrocytes. The absence of DEA 1.1 on platelets from DEA 1.1-positive dogs suggests that their platelets do not express DEA 1.1 and will not induce production of anti-DEA 1.1 antibodies that might lead to platelet refractoriness or reactions to a subsequent transfusion of DEA 1.1positive erythrocytes.

Detection and quantification of Duffy antigen on bovine red blood cell membranes using a polyclonal antibody

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fertility-associated antigen on Nelore bull sperm and reproductive outcomes following first-service fixed-time AT of Nelore cows and heifers

The objective was to determine whether the presence of fertility-associated antigen (FAA) on sperm collected from Nelore (Bos indicus) bulls can be used to assess potential fertility of sperm for use at first-service fixed-time AI (TAI). Six Nelore bulls were selected based on FAA status (FAA-negative: N = 3; FAA-positive: N = 3) and the ability to produce neat semen with >= 70% morphologically normal sperm and 60% estimated progressive motility before cryopmservation. In Experiment 1, suckled multiparous Nelore cows (N = 835) were evaluated for body condition score (BCS) and received an intravaginal progesterone device (CIDR) and 2.0 mg of estradiol benzoate (Day 0). on Day 9 the CIDR was removed, 12.5 mg of PGF(2 alpha) and 0.5 mg of estradiol cypionate were administered, and calves were removed for 48 h. All cows received TAI on Day II (48 h after CIDR removal). Pregnancy per TAI (P/TAI) was not different between FAA-positive and FAA-negative bulls (41.5% vs. 39.3%, respectively). There was an effect of AI technician on P/TAI (36.0% vs. 43.9%; P < 0.05) and BCS tended to affect P/TAI (P = 0.09), as cows with BCS >= 2.75 were 1.4 times more likely to become pregnant compared with cows with BCS < 2.75. In Experiment 2, nulliparous Nelore heifers (N = 617) were evaluated for BCS and received a CIDR and estradiol benzoate (2.0 mg) on Day 0. on Day 7, all heifers received PGF(2 alpha) (12.5 mg). on Day 9, CIDR inserts were removed and all heifers received estradiol cypionate (0.6 mg) and 200 IU eCG. All heifers received TAI on Day 11 (48 h after CIDR removal). Pregnancy/TAI was different (P = 0.04) between FAA-positive and FAA-negative bulls (33.7% vs. 40.7%, respectively). Presence of FAA on sperm was unsuccessful in assessing the potential fertility of sperm for use in TAI. (C) 2012 Elsevier B.V. All rights reserved.

Comparative evaluation of an indirect ELISA test for diagnosis of swine cysticercosis employing antigen from Taenia solium and Taenia crassiceps metacestodes

Taenia solium cysticercosis is still a serious public health problem in several countries where poverty and lack of hygiene favor transmission. Because pigs are the primary intermediate hosts, prevalence of porcine cysticercosis is a reliable indicator of active transmission zones. Serological diagnostic methods are important tools for epidemiological studies since they can be applied to living animals on a large scale. Four antigen preparations (cyst fluid and crude) from T. solium and T. crassiceps metacestodes were compared for swine cysticercosis diagnosis by indirect ELISA (IE). Twenty-eight serum samples from swine naturally and experimentally infected by cysticerci of T. solium and 56 serum samples from swine reared in commercial herds were tested. Best results of overall sensitivity were obtained by the use of cyst fluid and crude antigen of T. crassiceps metacestode (100 and 96.4%, respectively). Using homologous antigen preparations we have observed higher specificity percentage (98.2% for cyst fluid and 96.4% for crude metacestode T. solium antigen). We concluded that sensitivity is of far more importance than specificity for identification of endemic areas in order to prevent transmission to man. We conclude, therefore, that IE performed with cyst fluid antigen of T. crassiceps metacestode is a better tool for that purpose. (C) 2000 Elsevier B.V. B.V. All rights reserved.

Comparison between ELISA using total antigen and immunochromatography with antigen rK39 in the diagnosis of canine visceral leishmaniasis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparative evaluation of enzyme-linked immunosorbent assay based on crude and purified antigen in the diagnosis of canine visceral leishmaniasis in symptomatic and oligosymptomatic dogs

This study evaluated the performance of crude total antigen (CTA) and fucose-mannose ligand antigen (FML) in an enzyme-linked immunosorbent assay for diagnosis of canine visceral leishmaniasis (CVL). The assays used sera from known negative controls (n = 30), clinically symptomatic (n = 30) and oligosymptomatic (n = 30) parasitologically proven infection (by microscopy). Aspirates of popliteal lymph node from infected canines were colleted to score parasitism and compared with the ELISA results. The study indicated that FML used in ELISA provided high sensitivity for detecting oligosymptomatic dogs (90%) and CTA showed greater sensitivity than FML for symptomatic canines (90%). In oligosymptomatic dogs, specificity was 100% for CTA-ELISA, but in symptomatic dogs, FML specificity was higher (96.7%) than CTA-ELISA (93.3%). A significant correlation was observed between the degree of parasitism and the results obtained in CTA-ELISA. Since no available antigen offers 100% specificity and sensitivity for CVL diagnosis, the choice of antigen used must depend on the aim of the investigation. (C) 2008 Elsevier B.V. All rights reserved.

Role of catecholaminergic neurones of the caudal ventrolateral medulla in cardiovascular responses induced by acute changes in circulating volume in rats

Several findings suggest that catecholaminergic neurones in the caudal ventrolateral medulla (CVLM) contribute to body fluid homeostasis and cardiovascular regulation. The present study sought to determine the effects of lesions of these neurones on the cardiovascular responses induced by changes in circulating volume. All experiments were performed in male Wistar rats (320-360 g). Medullary catecholaminergic neurones were lesioned by microinjection of anti-dopamine beta-hydroxylase-saporin (6.3 ng in 60 nl; SAP rats, n = 14) into the CVLM, whereas sham rats received microinjections of free saporin (1.3 ng in 60 nl, n = 15). Two weeks later, rats were anaesthetized (urethane, 1.2 g kg(-1), I.V..), instrumented for measurement of mean arterial pressure (MAP), renal blood flow (RBF) and renal vascular conductance (RVC), and infused with hypertonic saline (HS; 3 M NaCl, 0.18 ml (100 g body weight)(-1), I.V.) or an isotonic solution (volume expansion, VE; 4% Ficoll, 1% of body weight, I.V.). In sham rats, HS induced sustained increases in RBF and RVC (155 +/- 7 and 145 +/- 6% of baseline, at 20 min after HS). In SAP rats, RBF responses to HS were blunted (125 +/- 6%) and RVC increases were abolished (108 +/- 5%) 20 min after HS. Isotonic solution increased RBF and RVC in sham rats (149 +/- 10 and 145 +/- 12% of baseline, respectively, at 20 min). These responses were reduced in SAP rats (131 +/- 6 and 126 +/- 5%, respectively, at 20 min). Pressor responses to HS were larger in SAP rats than in sham rats (17 +/- 5 versus 9 +/- 2 mmHg, at 20 min), whereas during VE these responses were similar in both groups (6 +/- 3 versus 4 +/- 6 mmHg, at 20 min). Immunohistochemical analysis indicates that microinjections of anti-D beta H-saporin produced extensive destruction within the A1/C1 cell groups in the CVLM. These results suggest that catecholaminergic neurones mediate the cardiovascular responses to VE or increases in plasma sodium levels.

Dissociation between the circulating renin-angiotensin system and angiotensin II receptors in central losartan-induced hypertension

Losartan, an AT1 angiotensin II (ANG II) receptor non-peptide antagonist, induces an increase in mean arterial pressure (MAP) when injected intracerebroventricularly (icv) into rats. The present study investigated possible effector mechanisms of the increase in MAP induced by icv losartan in unanesthetized rats. Male Holtzman rats (280-300 g, N = 6/group) with a cannula implanted into the anterior ventral third ventricle received an icv injection of losartan (90 µg/2 µl) that induced a typical peak pressor response within 5 min. In one group of animals, this response to icv losartan was completely reduced from 18 ± 1 to 4 ± 2 mmHg by intravenous (iv) injection of losartan (2.5-10 mg/kg), and in another group, it was partially reduced from 18 ± 3 to 11 ± 2 mmHg by iv prazosin (0.1-1.0 mg/kg), an alpha1-adrenergic antagonist (P<0.05). Captopril (10 mg/kg), a converting enzyme inhibitor, injected iv in a third group inhibited the pressor response to icv losartan from 24 ± 3 to 7 ± 2 mmHg (P<0.05). Propranolol (10 mg/kg), a ß-adrenoceptor antagonist, injected iv in a fourth group did not alter the pressor response to icv losartan. Plasma renin activity and serum angiotensin-converting enzyme activity were not altered by icv losartan in other animals. The results suggest that the pressor effect of icv losartan depends on angiotensinergic and alpha1-adrenoceptor activation, but not on increased circulating ANG II.

MyoD, myogenin and proliferating cell nuclear antigen expression in growing Nile tilapia (Oreochromis niloticus L.)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Human Platelet Antigen Genotype Is Associated With Progression of Fibrosis in Chronic Hepatitis C

Although progression of fibrosis in the chronic hepatitis C depends on environmental, viral, and host factors, genetic polymorphisms have been associated recently with this progression, including the expression of integrins, adhesion proteins. Some integrins expressed on the platelet membrane show polymorphic antigenic determinants called human platelet antigens (HPA), where the major ones are HPA-1, -3, -5. The association between HCV infection and HPA-5b has been demonstrated. Similarly, the HPA profile could determine if HPA is related to progression of fibrosis. The goal of this study was to evaluate the association between the frequencies of HPA-1, -3, and -5 and degree of fibrosis in HCV-infected patients. Genomic DNA from 143 HCV-infected patients was used as the source for HPA genotyping by PCR-SSP or PCR-RFLP. Progression of fibrosis was evaluated using the METAVIR scoring system, and the patients were grouped according to degree of fibrosis into G1 (n = 81, with F1, portal fibrosis without septa or F2, few septa) and G2 (n = 62, with F3, numerous septa, or F4, cirrhosis). Statistical analysis was performed using the proportional odds model. The genotypic frequency of HPA-1a/1b was significantly higher in the patients in G2. To evaluate the influence of the time of infection to the development of fibrosis and its effect on the genetic factor HPA-1, 96 patients from 143 studied were evaluated considering the time of HCV infection, and these results suggest that the HPA-1a/1b genotype promotes the development of fibrosis in HCV infection with time. J. Med. Virol. 84: 56-60, 2012. (C) 2011 Wiley Periodicals, Inc.