The use of babosa (Aloe vera) in treating burns: a literature review

Alo vera is a centenary remedy use for minor wounds and burns, but its mechanism of wound healing has not been know since. This article will evaluate and gather evidence of the effectiveness and safety of the use of aloe vera in the treatment of burns. A systematic review was carried out on the databases: MEDLINE, LILACS, DECS, SCIELO, in the last 7 years, with the descriptors: "Aloe", "Burns" and "treatment". 16 articles were found. After using the exclusion criteria; research in non-humans and literature review; 5 articles were selected. The article Teplick et al. (2018) performed an in vitro clinical experiment in A. Vera solution, and demonstrated that there was proliferation and cell migration of human skin fibroblasts and keratinocytes, in addition to being protective in the death of keratonocytes. That is, it accelerates the healing of wounds. Muangman et al. (2016), evaluated 50 patients with 20% of the total body surface area burned with second-degree burns, between 18-60 years old, with half of the group receiving gauze dressings with soft paraffin containing 0.5% chlorhexidine acetate and the other half receiving polyester dressings containing extracts of medicinal plants mainly Aloe Vera. It had positive results, a higher healing speed and shorter hospital stay compared to the control group. Hwang et al. (2015) investigated the antioxidant effects of different extracts from 2,4,6,8,12 months of Aloe Vera. And the 6-month concentrated extract of 0.25 mg / mL had a higher content of flavonoids (9.750 mg catechin equivalent / g extract) and polyphenols (23.375 mg gallic acid equivalent / g extract) and the greater ferric reducing antioxidant power (0.047 mM equivalent ferrous sulfate / mg extract), that is, greater potential for free radical scavenging and also a protective effect against oxidative stress induced by tert-butyl hydroperoxide (t-BHP), suggesting evidence of a bioactive potential of A. vera . However, in the article Kolacz et al. (2014) suggested as an alternative treatment the use of Aloe Vera dressing in combination with honey, lanolin, olive oil, wheat germ oil, marshmallow root, wormwood, comfrey root, white oak bark, lobelia inflata, glycerin vegetable oil, beeswax and myrrh, without obtaining significant and conclusive results that would allow the conventional treatment of burns to be subsidized. Finally, in the article by Zurita and Gallegos (2017), it carried out a descriptive cross-sectional study with 321 people, both sexes between 17-76 years of age, of an inductive nature, exploring the experience of this population and their behavioral attitudes regarding the treatment of dermatoses. Aloe vera had 13.8% cited by individuals in the treatment of acne and 33.6% in the treatment of burns. Even with evidence that suggests the efficacy in the treatment of burns with the use of Aloe Vera extract, further clinical trials with larger sample space on the use of Aloe vera dressings in medium burns are suggested for further conclusions.

Goats reinfected with Toxoplasma gondii: loss of viable prolificacy and gross revenue

ABSTRACTWe determined the reproductive parameters and clinical disorders in pregnant goats infected and reinfected with Toxoplasma gondii, and posteriorly the loss of gross revenue due to congenital toxoplasmosis was estimated. Of the 25 non-pregnant females negative for T. gondii, 20 were orally inoculated (ME 49 strain) and of these, 15 pregnant females chronically infected were orally reinoculated (VEG strain) with T. gondii oocysts. Five groups were formed (n=5): GI, GII and GIII (reinoculations at 40, 80 and 120 days of gestation, respectively), GIV (inoculation) and GV (no inoculation). Clinical and serological exams were performed on days 0 (prior to inoculation), 3, 6 9, 15 and 21 and every 7 days post-inoculation. Exams were also performed on day 3 and every 7 days post-reinoculation. Reproductive management was performed on all females and initiated when the females infected displayed IgG titers IFAT<1,024. From the average prolificacy indexes of each experimental group were estimated: total production of kilograms of live weight (total kg LW) of goats for slaughter, gross revenue and loss of gross revenue in U.S. dollars (US$), designed for a herd of 1,000 matrices. The unviable prolificacy indexes were 0.8 (GI), 1.2 (GII) and 0.2 (GIII). Clinical disorders affected 57.1% (GI), 75.0% (GII) and 16.7% (GIII) of the offspring of goats reinfected with T. gondii. Congenital toxoplasmosis in goats reinfected resulted in the loss of 26.5% of gross revenues, being GI (US$ 10,577.60 or 57.1%) and GII (US$ 12,693.12 or 60%) holders of the highest values and percentages of economic losses. It was found that congenital toxoplasmosis reinfection cause clinical disorders in goats chronically infected with T. gondii and their offspring with birth of unviable animals and loss of gross revenue, at different stages of pregnancy (40, 80 and 120 days of gestation), being in the initial and intermediate stages of pregnancy the largest estimates of these losses.

Effects of a high-energy diet on oocyte quality and in vitro embryo production in Bos indicus and Bos taurus cows

The effects of different dietary energy levels [100 and 170% for maintenance (M) and high energy (1.7M), respectively] on metabolic, endocrine, and reproductive parameters were evaluated in nonlactating Bos indicus (Gir; n=14) and Bos taurus (Holstein; n=14) cows submitted to ultrasound-guided ovum pick-up followed by in vitro embryo production. The oocyte donor cows were housed in a tiestall system and fed twice daily (0800 and 1600 h). Twenty-one days before the beginning of the experiment, the animals were fed with a maintenance diet for adaptation followed by the experimental diets (M and 1.7M), and each cow underwent 9 ovum pick-up procedures 14 d apart. The recovered oocytes were cultured in vitro for 7 d. We measured glucose and insulin concentrations and performed glucose tolerance tests and the relative quantification of transcripts (PRDX1, HSP70.1, GLUT1, GLUT5, IGF1R, and IGF2R) from the oocytes recovered at the end of the experimental period. No interactions were observed between the effects of genetic groups and dietary energy level on the qualitative (viable oocytes, quality grade, and oocyte quality index) and quantitative (oocytes recovered) oocyte variables. There were no effects of dietary energy level on the qualitative and quantitative oocyte variables. However, Bos indicus cows had greater numbers of recovered structures, viable oocytes, and A and B oocyte grades as well as better oocyte quality index scores and lower DNA fragmentation rates compared with Bos taurus donors. In vitro embryo production (cleavage and blastocyst rates and number of embryos) was similar between diets, but the 1.7M diet reduced in vitro embryo production in Bos indicus cows after 60 d of treatment. Moreover, Bos indicus cows on the 1.7M diet showed lower transcript abundance for the HSP70.1, GLUT1, IGF1R, and IGF2R genes. All cows fed 1.7M diets had greater glucose and insulin concentrations and greater insulin resistance according to the glucose tolerance test. In conclusion, increasing dietary energy did not interfere with oocyte numbers and quality, but the 1.7M diet reduced in vitro embryo production in Bos indicus cows after 60 d of treatment. Finally, Bos indicus cows had greater oocyte quality, greater numbers of viable oocytes and greater in vitro embryo yield than Bos taurus.

Study of candidate genes for dyslexia in Brazilian individuals

Dyslexia or reading disability (RD) is the most common childhood learning disorder and a significantly heritable trait. Many recent studies have investigated the genetic basis of dyslexia, and several candidate genes have been proposed. Among these, DCDC2 and KIAA0319 have emerged as the strongest candidate genes for dyslexia; however studies have not provided uniformly supportive results. The aim of this study was to assess the contribution of proposed candidate genes to the molecular etiology of dyslexia in a Brazilian sample. Large deletions and duplications in the candidate genes DCDC2, KIAA0319, and ROBO1 were investigated in 51 dyslexic subjects. Furthermore, a family-based association study was performed to investigate whether associations observed in other populations with variants in the DCDC2 and KIAA0319 genes were reproducible in Brazilian dyslexic individuals. Our analysis did not detect any deletions or duplications in the genes studied, and we found no evidence that the allelic variants in the two candidate genes were significantly associated with RD in our sample. Our data do not support a role of the DCDC2/KIAA0319 locus in influencing dyslexia as a categorical trait. Given the genetic complexity of dyslexia, it is plausible that both genes contribute to an increased risk, but the relative influence of these 2 genes on RD varies in different study samples, and/or depends on analytical approaches.

Cytotoxicity and expression of genes involved in the cellular stress response and apoptosis in mammalian fibroblast exposed to cotton cellulose nanofibers

Cellulose nanofibers (CNF) have mechanical properties that make them very attractive for applications in the construction of polymeric matrices, drug delivery and tissue engineering. However, little is known about their impact on mammalian cells. The objective of this study was to evaluate the cytotoxicity of CNF and their effect on gene expression of fibroblasts cultured in vitro. The morphology of CNF was analyzed by transmission electron microscopy and the surface charge by Zeta potential. Cell viability was analyzed by flow cytometry assay and gene expression of biomarkers focused on cell stress response such as Heat shock protein 70.1 (HSP70.1) and Peroxiredoxin 1 (PRDX1) and apoptosis as B-cell leukemia (BCL-2) and BCL-2 associated X protein (BAX) by RT-PCR assay. Low concentrations of CNF (0.02-100 μg ml(-1)) did not cause cell death; however, at concentrations above 200 μg ml(-1), the nanofibers significantly decreased cell viability (86.41 ± 5.37%). The exposure to high concentrations of CNF (2000 and 5000 μg ml(-1)) resulted in increased HSP70.1, PRDX1 and BAX gene expression. The current study concludes that, under the conditions tested, high concentrations (2000 and 5000 μg ml(-1)) of CNF cause decreased cell viability and affect the expression of stress- and apoptosis-associated molecular markers.

Zinc(II) phthalocyanines immobilized in mesoporous silica Al-MCM-41 and their applications in photocatalytic degradation of pesticides

In the present study the authors investigated a set of three new zinc(II) phthalocyanines (zinc(II) tetranitrophthalocyanine (ZnTNPc), zinc(II) tetra(phenyloxy)phthalocyanine (ZnTPhOPc) and the tetraiodide salt of zinc(II)tetra(N,N,N-trimethylaminoethyloxy) phthalocyaninate (ZnTTMAEOPcI)) immobilized into Al-MCM-41 prepared via ship-in-a-bottle methodology. The samples were fully characterized by diffuse reflectance-UV-vis spectroscopy (DRS-UV-vis), luminescence, thermogravimetric analysis (TG/DSC), N(2) adsorption techniques and elemental analysis. A comparative study was made on the photocatalytic performance upon irradiation within the wavelength range 320-460nm of these three systems in the degradation of pesticides fenamiphos and pentachlorophenol. ZnTNPc@Al-MCM-41 and ZnTTMAEOPcI@Al-MCM-41 were found to be the most active systems, with the best performance observed with the immobilized cationic phthalocyanine, ZnTTMAEOPcI@Al-MCM-41. This system showed high activity even after three photocatalytic cycles. LC-MS product characterization and mechanistic studies indicate that singlet oxygen ((1)O(2)), produced by excitation of these immobilized photosensitizers, is a key intermediate in the photocatalytic degradation of both pesticides.

Correlação entre digestibilidade e comportamento ingestivo de novilhas suplementadas a pasto

Objetivou-se, com este estudo, avaliar as correlações entre a digestibilidade aparente e o comportamento ingestivo de novilhas mestiças a pasto. O experimento foi conduzido na fazenda Princesa do Mateiro, município de Ribeirão do Largo, Bahia. Foram utilizadas 20 novilhas com grau de sangue 5/8 Guzerá linhagem leiteira e 3/8 Holandesa, com média de 18 meses de idade e peso corporal médio de 187±13,1 kg. O experimento teve duração de 224 dias e os animais criados em pastejo rotacionado de Brachiaria brizantha "Marandú". Verificou-se uma correlação positiva entre o tempo de pastejo e o coeficiente de digestibilidade da fibra em detergente neutro (CDFDN). Correlações negativas foram verificadas entre o tempo de outras atividades e CDFDN. O tempo de alimentação no cocho apresentou correlações negativas com coeficiente de digestibilidade da matéria seca (CDMS), matéria orgânica (CDMO), carboidratos não fibrosos (CDCNF), carboidratos totais (CDCHOT). Ob-servou-se uma correlação positiva entre o tempo de alimentação total e mastigação total com o CDFDN. O número de períodos de pastejo e ruminação apresentaram correlações negativas com CDMS, CDMO, CDCNF, CDCHOT. Também, verificou-se correlação acima de 0,90 para os nutrientes digestíveis totais (NDT), podendo também ser incluída em equações de predição de consumo. O número de período de alimentação no cocho apresentou correlação negativa com CDMO e coeficiente de digestibilidade de proteína bruta (CDPB). O tempo por período de ruminação apresentou correlação positiva com CDMO, CDCNF, CDCHOT, NDT e CDPB. O tempo por período de outras atividades apresentou correlação positiva com CDCNF e NDT. Correlações negativas foram verificadas entre a taxa de bocados e CDMS, CDMO, CDCNF, CDCHOT e CDPB. O tempo por deglutição correlacionou positivamente com CDMS, CDMO, CDCNF, CDCHOT, NDT, CDPB. A massa do bocado e bocados por deglutição não apre-sentaram correlações com nenhuma das variáveis da digestibilidade. O número de mastigação merícica por dia apresentou correlações negativas com NDT. O tempo de pastejo e ruminação não apresentaram relação com os demais coeficientes de digestibilidade aparente de novilhas mestiças a pasto. O coeficiente da digestibilidade da fibra em detergente neutro provoca variações no tempo de pastejo.

17 CELL CYCLE SYNCHRONIZATION OF BOVINE FIBROBLASTS BY AZADIRACHTA INDICA EXTRACTS

One requirement for somatic cell nuclear transfer (NT) is the coordination between donor cell cycle and recipient cytoplasm. As an alternative to commercially available substances to synchronize the cell cycle in G0/G1, we tested 2 extracts, aqueous and hexane obtained from the plant Azadirachta indica A. Juss (popularly called Neem). Extracts from this plant have shown antiviral, antibacterial and anticancer activities, widely described in the literature (Kumar et al. 2009 Invest. New Drugs 27, 246–252). The hexane extract was prepared in the Soxhlet apparatus until total collapse and then submitted to rotary evaporation. The aqueous extract was prepared by dynamic maceration and was subsequently lyophilized. Bovine fibroblasts collected from Gyr cows were cultured in DMEM (Sigma) supplemented with 10% fetal cow serum (FCS) and incubated at 37°C, 5% CO2 and 95% humidity. After obtaining 70% of cell confluence, the extract was added to cells at the following concentrations: 0 μg mL–1 (negative control), 50 μg mL–1, 100 μg mL–1, 200 μg mL–1 and 300 μg mL–1, for 12 and 24 h. Simultaneously, a group with serum starvation (positive control; cells cultured in DMEM plus 0.5% FBS for 3 days) was prepared. Three repetitions were performed in triplicate for each concentration and control groups. Cell cycle readings were performed by flow cytometry (Facs Callibur, Becton Dickinson, San Jose, CA, USA) and DNA histograms were analysed by WinMDI software to determine the percentage of cells in G0/G1 phase, S and G2 cell cycle, so that 10 000 cells were analysed in each reading on a flow cytometer. Data were analysed by analysis of variance and means were compared by Student-Newman-Keuls test. The percentages of cells at G0/G1 phase for aqueous extracts were lower (P < 0.05), regardless of the concentration and exposure time, than the 0 μg mL–1 (83.73 ± 1.14%) and serum starvation (86.64 ± 1.44%). In contrast, the percentages of cells synchronized at G0/G1 with 50 μg mL–1 for 12 h (84.23 ± 0.56%), 50 μg mL–1 for 24 h (85.66 ± 0.57%), 100 μg mL–1 for 12 h (87.85 ± 0.51%) and 200 μg mL–1 for 12 h (85.87 ± 0.45%) using hexane extracts were higher (P < 0.05) than with 0 μg mL–1 (81.44 ± 0.29%), but lower (P < 0.05) than the serum starvation (91.33 ± 0.31%). In conclusion, hexane extracts from the plant Azadirachta indica A. Juss can synchronize mammalian cell cycle at G0/G1 despite the low proportion when compared with serum starvation. Studies to evaluate efficiency of cell cycle resuming and viability after somatic cell nuclear transfer are ongoing. Financial support: FAPEMIG, CNPq and Project 01.07.01.002.

20 ALTERED GENE EXPRESSION IN BOVINE SOMATIC CELL NUCLEAR-TRANSFERRED EMBRYOS AFTER TRICHOSTATIN A TREATMENT

Trichostatin A is a histone deacetylase inhibitor that improves histone acetylation and chromatin remodeling of somatic cell nuclear-transferred embryos (Iager et al. 2008 Cloning Stem Cells 10, 371–379; Maalouf et al. 2009 BMC Dev. Biol. 9, 11). We have previously observed that it also improves quality of bovine cloned embryos, which may increase pregnancy rates. This study aimed to evaluate the effect of trichostatin A treatment of zygotes on relative abundance of 9 transcripts in bovine nuclear-transferred blastocysts. In vitro matured oocytes were enucleated, fused to somatic cells and activated with ionomycin (Camargo et al. 2011 Reprod. Fertil. Dev. 23, 122). After activation, putative zygotes were randomly separated into 2 groups: NT-TRICHO, zygotes were cultured for 4 h in 6-DMAP followed by 7 h in CR2 aa medium plus with 2.5% fetal calf serum (FCS; Nutricell, Campinas, Brazil), both supplemented with 50 nM trichostatin A (Sigma); NT-CONT, zygotes were cultured in the same described conditions without thichostatin A supplementation. In vitro-fertilized embryos (IVF group) were used as a calibrator for relative transcript quantification. Embryos from the 3 groups were cultured in CR2 aa supplemented with 2.5% FCS under 5% CO2, 5% O2 and 90% N2 at 38.5°C. At 168 h postactivation, the embryos were rapidly frozen in liquid nitrogen. Pools of 10 blastocysts for each group were subject to RNA extraction and reverse transcription, in which cDNA was amplified by real-time PCR using the β-actin and GAPDH genes as endogenous references. The transcripts analysed encode high mobility group N1 (HMGN1), peroxiredoxin 1 (PRDX1), octamer-binding protein 4 (OCT4), insulin-like growth factor 1 and 2 receptors (IGF1r and IGF2r), glucose transporter 1 and 5 (GLUT1 and GLUT5), histone acetyltransferase (HAT) and heat shock protein 70.1 (HSP70) genes. Results were analysed by a pair-wise fixed reallocation randomization test using the REST software v.2. Data from NT-TRICHO and NT-CONT were compared with the IVF group and between themselves. The relative abundance of HSP70, PRDX1, IGF2r and HMGN1 transcripts was higher (P < 0.05) in NT-TRICHO compared with the IVF group and no difference was detected for the other transcripts. In the NT-CONT group, the relative abundance of IGF2r and HAT was higher (P < 0.05), whereas IGF1r and OCT4 were lower (P < 0.05) compared with IVF embryos. When data from NT-TRICHO and NT-CONT were compared, a higher amount (P < 0.05) of stress-associated transcripts (HSP70 and PRDX1) were found in NT-TRICO blastocysts. These results suggest that although trichostatin A may improve chromatin remodeling, alterations on gene expression still persist in bovine somatic cell nuclear-transferred blastocysts in comparison with IVF embryos. Financial support: Embrapa Project 01.07.01.002, CNPq 403019/2008–7 and Fapemig.

137 DIFFERENTIAL GENE EXPRESSION OF IN VITRO-MATURED BOVINE OOCYTES WITH OR WITHOUT A POLAR BODY

Oocyte competence is associated with the amount of transcripts stored in the ooplasm and oocyte ability to extrude polar bodies (PB). To our knowledge, however, no data comparing mRNA levels between bovine oocytes maturated in vitro with or without PB are available. The aim of the present study was to compare the relative abundance of transcripts of glucose transporter 1 (GLUT1), insulin-like growth factor 1 receptor (IGF1R), insulin-like growth factor 2 receptor (IGF2R), growth differentiation factor-9 (GDF9) and aquaporin 3 (AQP3) genes between oocytes with and without PB (PB and NPB groups, respectively) following in vitro maturation. Immature bovine oocytes were obtained by follicular aspiration and matured in TCM-199 (Gibco Life Technologies, New York, NY, USA) containing 10% of oestrus cow serum and 20 μg mL–1 of FSH (Pluset, Serono, Italy) for 24 h under 5% CO2 in air at 38.5°C. Subsequently, oocytes were visually classified according to the presence or absence of PB and then denuded and rapidly frozen in liquid nitrogen. Three pools of 10 oocytes for each group were subjected to total RNA extraction using the RNeasy Micro Kit (Qiagen GmbH, Hilden, Germany) according to the manufacturer's instructions and treated with DNase. Reverse transcription and cDNA amplification were performed using the TransPlex Complete Whole Transcriptome Amplification Kit (WTA2, Sigma, St. Louis, MO, USA) according to the manufacturer's instructions. Relative abundance of the target transcripts was performed by quantitative RT-PCR (Applied Biosystems Prism 7300 Sequence Detection Systems, Foster City, CA, USA) using a mixture of SYBR® Green PCR Master Mix (Applied Biosystems), 200 ng of cDNA, nuclease-free water and specific primers for each reaction. Expression of the β-actin gene was used as an endogenous reference. Relative gene expression analysis was performed using the software REST© 2005 using the Pair Wise Fixed Reallocation Randomization Test©. The relative expression values are presented as mean ± standard error. The relative abundance of GLUT1 (0.81 ± 0.07), IGF2R (0.72 ± 0.07) and GDF9 (0.82 ± 0.10) genes was lower (P < 0.05) for NPB oocytes. There was no difference (P > 0.05) in relative abundance between PB and NPB groups for the other genes. The results suggest that the amount of some transcripts stored in the matured ooplasm is associated with the presence of PB. The authors acknowledge FAPEMIG, CNPq and Innovation Network Project on Animal Reproduction (01.07.01.002).

Zingiber officinale Roscoe (ginger) as an adjuvant in cancer treatment: a review

Despite acquiring a strong understanding of the molecular basis and advances in treatment, cancer is the second major cause of death in the world. In clinics, the stagedependent treatment strategies may include surgery, radiotherapy and systemic treatments like hormonotherapy and chemotherapy, which are associated with side effects. The use of traditional herbal medicine in cancer patients is on a rise, as it is believed that these medications are non toxic and alleviate the symptoms of cancer, boost the immune system, or may tackle the cancer itself. Since antiquity the rhizome of Zingiber officinale Roscoe commonly known as ginger (family Zingiberaceae) have widely been used as a spice and condiment in different societies. Additionally, ginger also has a long history of medicinal use in various cultures for treating common colds, fever, to aid digestion, treat stomach upset, diarrhoea, nausea, rheumatic disorders, gastrointestinal complications and dizziness. Preclinical studies have also shown that ginger possesses chemopreventive and antineoplastic properties. It is also reported to be effective in ameliorating the side effects of γ-radiation and of doxorubicin and cisplatin; to inhibit the efflux of anticancer drugs by P-glycoprotein (P-gp) and to possess chemosensitizing effects in certain neoplastic cells in vitro and in vivo. The objective of this review is to address observations on the role of ginger as adjuvant to treatment modalities of cancer. Emphasis is also placed on the drawbacks and on future directions for research that will have a consequential effect on cancer treatment and cure.

209 EFFECT OF HEAT STRESS ON DEVELOPMENT OF IN VITRO-FERTILIZED AND PARTHENOGENETIC BOVINE EMBRYOS

Heat stress has been a challenge for bovine reproduction in tropical and subtropical environments. Although the role of the oocyte in thermotolerance has been studied, little attention has been paid to the contributions of sperm to embryo resistance to heat shock. The current study aimed to evaluate the development of fertilized and nonfertilized (parthenogenetic) bovine embryos undergoing heat stress during the pre-implantation stage. Cumulus–oocyte complexes obtained from ovaries collected from Bos indicus × Bos taurus crossbred cows at slaughter were in vitro matured with TCM-199 supplemented with 20 μg mL–1 of FSH, under 5% CO2 at 38.5°C for 24 h. Afterward, oocytes were randomly allocated into 2 groups: 1) IVF and 2) PART (chemical activation for parthenogenesis induction). In vitro-fertilized oocytes were cultured with 2.0 × 106 Holstein sperm mL–1 in Fert-TALP medium supplemented with heparin, for 20 h. For chemical activation, oocytes were activated with calcium ionomycin for 4 min, followed by 6-DMAP for 4 h, both in CR2aa medium supplemented with 0.1% BSA. Presumptive IVF (n = 1 262) or PART (n = 1 206) zygotes were denuded by vortexing and cultured in CR2aa medium with 2.5% of FCS under 5% CO2, 5% O2, and 90% N2 at 38.5°C. At 44 h post-insemination or chemical activation, embryos were exposed to 38.5 or 41°C for 12 h in an atmosphere of 5% CO2, 5% O2, and 90% N2. After that, embryos were cultured at 38.5°C under 5% CO2, 5% O2, and 90% N2 until Day 8 post-insemination. Blastocyst rates were evaluated at Day 7 and Day 8 post-insemination and were calculated based on the total number of presumptive zygotes. Blastocysts at 192 h post-insemination or activation were fixed and permeabilized for TUNEL assay (DeadEndTM Florimetric TUNEL System, Promega, Madison, WI) according to the manufacturer’s instructions. The effect of heat stress was compared within groups (IVF or PART) and the data were analysed by ANOVA. As expected, heat stress reduced the blastocyst rate of IVF embryos at Day 7 (24.3 ± 2.0% and 17.4 ± 2.2% for nonstressed and stressed IVF embryos; P < 0.05) and at Day 8 (32.4 ± 1.9% and 23.0 ± 2.1% for nonstressed and stressed IVF embryos; P < 0.01). However, the effect of heat stress on blastocyst rate of PART embryos was observed only at Day 8 post-insemination (30.0 ± 1.7% and 22.6 ± 2.0% for nonstressed and stressed PART embryos; P < 0.05), with no difference in blastocyst rate at Day 7 (21.6 ± 1.5% and 18.2 ± 1.8% for nonstressed and stressed PART embryos; P > 0.05). There was no difference in total cell numbers between nonstressed and stressed IVF or PART embryos. Apoptosis cell numbers and the apoptotic cell index were higher (P < 0.05) for stressed IVF (18.45 ± 1.24 and 0.16 ± 0.00) and PART (16.40 ± 5.20 and 0.17 ± 0.00) embryos than for nonstressed IVF (13.70 ± 0.75 and 0.13 ± 0.00) and PART (14.15 ± 0.86 and 0.13 ± 0.00) embryos. In conclusion, heat stress can induce apoptosis in both IVF and PART embryos, but its effect on pre-implantation development may occur at earlier stages in IVF embryos when compared with PART embryos. Financial support from Fapemig and CNPq.

229 EVALUATION OF OOCYTE QUALITY RECOVERED FROM Gir BREED COWS WITH SYNCHRONIZED FOLLICULAR WAVE ON IN VITRO EMBRYO PRODUCTION

Recent data reveal that approximately 80% of bovine embryos produced in vitro worldwide are from (Brazil J. H. M. Viana, personal communication). Adoption of this biotechnology by Brazilian producers might be attributed to particularities of the Bos indicus subspecies. Zebu breeds provide 2 to 3 times more viable oocytes than Bos taurus breeds per ovum pickup (OPU) session. This work aimed to evaluate the quality of cumulus–oocyte complexes (COC) retrieved from Gir breed cows (B. indicus) by OPU with a synchronized follicular wave and subjected to an in vitro embryo production (IVP) technique. All COC were obtained by OPU of 14 Gir cows performed every 14 days. There were 4 OPU sessions, preceded by synchronization of the follicular waves. Wave synchronization was achieved by an injection of 2 mg of oestradiol benzoate followed by the insertion of a norgestomet implant that stayed in place for 5 days. On Day 5, follicles of 2 to 8 mm were aspirated. The oocytes recovered were distributed according to classification: Group 1, with ≥3 cumulus cell layers and homogeneous or slightly heterogeneous cytoplasm (n = 314); and Group 2, ≤2 cumulus cells layers and slightly or coarsely granulated cytoplasm (n = 236). Oocytes from both groups were followed to in vitro maturation–IVF–fertilization–in vitro culture. Two (Day 2) and 8 (Day 8) days after the beginning of fertilization, the cleavage and blastocyst rates were measured, respectively. The statistical analyses were performed using a chi-square test (P < 0.05). The mean cleavage rates observed were 72.93 and 69.07% (not significant), whereas the mean blastocyst rates were 37.90 and 17.80%, and were significantly different for Groups 1 and 2, respectively. The results suggest that the morphology of oocytes (number of cumulus cell layers and cytoplasm homogeneity) is a strong indicator of the in vitro developmental capacity of oocytes recovered from Gir cows with synchronized follicular waves, although we did not observe compromised cleavage rates. Financial support was provided by Fapesp/Fapemig/CNPq/Embrapa. Epamig/Faz. Calciolândia/Nutricell–Nutrientes Celulares is acknowledged.

31 DEVELOPMENT AND APOPTOSIS IN BOVINE CLONED EMBRYOS RECONSTRUCTED WITH OOCYTES COLLECTED BY REPEATED OVUM PICKUP SESSIONS OR FROM SLAUGHTERED COW OVARIES

The oocyte has important components for nuclear reprogramming and its cytoplasmic background may influence the somatic cell nuclear transfer success. The current study attempted to evaluate the competence of cytoplasm from oocytes recovered by repeated ovum pickup (OPU) in living cows (OPU group) or obtained from ovaries collected at slaughterhouse from unknown source crossbred cows (SH group) to produce nuclear-transferred bovine embryos. For the OPU group, oocytes were recovered from 4 Bos indicus × Bos taurus crossbred cows in 4 repeated OPU sessions. Oocytes of OPU and SH groups were matured in vitro for 17 to 18 h, denuded and exposed to Hoechst 33342 (Sigma, St. Louis, MO, USA) and cytochalasin (Sigma) before enucleation. Embryos of OPU (n = 100) and SH (n = 105) groups were reconstructed with somatic cells from adult Gyr (Bos indicus) cow, fused with double electric pulse of 2.4 kV cm–1 for 30 μs and activated with ionomycin (Sigma) and 6-DMAP (Sigma). Embryos were cultured in CR2aa medium supplemented with 2.5% fetal calf serum (Nutricell, Campinas, Brazil) under 5% CO2, 5% O2, and 90% N2 at 38.5°C. Cleavage and blastocyst rates were evaluated at 72 h and 168 h post-activation, respectively. Blastocysts at 168 h post-activation were fixed and permeabilized for TUNEL assay (DeadEnd™ Fluorimetric TUNEL System, Promega, Madison, WI, USA), according to the manufacturer instructions. IVF bovine blastocysts (IVF group; n = 245) obtained with oocytes of slaughtered cows were used as control group. Fusion, cleavage, and blastocyst rates were analysed by chi-square test and total cell number, apoptotic cell number, and apoptotic cell index (calculated by dividing the apoptotic cell number by total cell number) were analysed by ANOVA. There were no differences (P > 0.05) in fusion (71.0% and 61.0%), cleavage (74.6% and 78.1%) or blastocyst (32.3% and 31.2%) rates between OPU and SH groups, respectively, but both groups presented greater (P < 0.05) blastocyst rates than the IVF group (15.1%). Total cell number (80.66 ± 5.36 and 82.10 ± 4.79), apoptotic cell number (12.66 ± 3.20 and 15.60 ± 3.04), and apoptotic cell index (0.15 ± 0.03 and 0.20 ± 0.04) were also similar (P > 0.05) between OPU and SH groups, respectively. However, apoptotic cell number (7.40 ± 0.93) and apoptotic cell index (0.07 ± 0.01) were lower (P < 0.05) in the IVF group than the SH group and similar (P > 0.05) to the OPU group. In conclusion, oocytes cytoplasm from both groups (OPU and SH) have the same potential to produce nuclear-transferred bovine embryos but only blastocysts from the OPU group present apoptosis levels similar to its in vitro-fertilized counterpart. Financial support: Fapemig and CNPq.

257 DIFFERENCES BETWEEN BOS TAURUS AND BOS INDICUS EMBRYOS: TRANSCRIPTS AMOUNTS

The Zebu breeds (Bos indicus) are different from European breeds (Bos taurus) in some aspects of their reproductive physiology, including follicle recruitment, number of follicular waves, and oocyte ultrastructure. On the other hand, embryos produced in vivo and in vitro show morphological and developmental differences, which can be related to culture environment. The aim of this study was to evaluate the effect of breed (Gyr v. Holstein) within embryo production system (in vivo and in vitro), as well as effect of production systems within breeds on relative abundance of transcripts related to formation, survival, and subsequent development of blastocysts, such as those involved in water and small solutes transport (Aquaporins 3 and 11), blastocoel formation (Na+/K+-ATPase a1 and |52), and cellular stress response (Peroxiredoxin 1). For in vivo embryo production, donors were superstimulated with FSH and inseminated, and embryos were recovered 7 days after AI. For in vitro embryo production, oocytes recovered by ovum pickup were in vitro matured and fertilized and then cultured for 7 days in culture medium under 5% CO2 at 38.5°C. For each group, blastocysts (n = 15) distributed in 3 pools were used for RNA extraction (RNeasy MicroKit, Qiagen, Valencia, CA, USA), followed by RNA amplification (Messageamp II amplification kit, Ambion-Applied Biosystems, Foster City, CA, USA) and reverse transcription (SuperScript III First-Stand Synthesis Supermix, Invitrogen, Carlsbad, CA, USA). The cDNA were submitted to real-time PCR, using the H2a gene as endogenous control, and analyzed by REST© software. To evaluate breed effect within the production systems, 2 comparisons were performed: (1) in vivo: Gyr v. Holstein and (2) in vitro: Gyr v. Holstein, considering Holstein data as 1.00. To evaluate production system effect within breeds, 2 comparisons were performed: (1) Gyr: in vivo v. in vitro and (2) Holstein: in vivo v. in vitro, considering in vivo produced embryo data as 1.00. The results are shown as mean ± SEM. For in vivo comparison between breeds, Aquaporin 3 (1.66 ± 0.77), Na+/K+-ATPase a1 (1.61 ± 0.56), and Peroxiredoxin 1 (1.61 ± 0.66) were up-regulated (P < 0.05) in Gyr embryos when compared with Holstein embryos, whereas for in vitro comparison, no differences (P > 0.05) were found. For comparisons between production systems within breeds, only Peroxiredoxin 1 (0.31 ± 0.39) was down-regulated (P < 0.01) in in vitro produced Gyr embryos when compared with in vivo counterparts. No differences (P > 0.05) were found between production systems for the Holstein breed. In conclusion, these data suggest that there is a difference on gene expression between Bos taurus and Bos indicus blastocysts, but such difference between breeds can be attenuated by the in vitro production system, indicating an embryo adaptation to the in vitro culture conditions. The data also suggest that the in vitro production system can influence the amount of transcripts in Gyr embryos. Other genes should be evaluated for a better understanding of these differences. Financial support was provided by CNPq and FAPEMIG.

245 EFFECT OF BOVINE OOCYTE MATURATION SYSTEM ON RELATIVE ABUNDANCE OF mRNA

The oocyte cytoplasm contains several transcripts that are important for early pre-implantation embryo development, and alterations on the amount of these stored mRNA can disturb oocyte competence. The aim of this study was to evaluate the relative abundance of specific transcripts in oocytes matured in vivo or in vitro. For in vitro maturation, immature oocytes were obtained by ovum pickup from 4 crossbred cows (group 1: G1) or from ovaries collected at a slaughterhouse (group 2: G2) and matured in TCM-199 containing 10% estrus cow serum and 2 μg FSH for 24 h under 5% CO2 in air at 38.5°C. For in vivo maturation, the same crossbred cows used in G1 received a progesterone intravaginal implant (CIDR®, Eazi-Breed CIDRO, São Paulo, Brazil) and 2 mg of estradiol benzoate (Estrogin®, Farmavet, São Paulo, Brazil) on Day 0. On Day 4, cows were superstimulated with 180 mg FSH (Folltropin®, Bioniche, Canada) injected in 6 decreasing doses every 12 h, and on Day 6, the cows received 0.53 mg of sodium cloprostenol (Ciosin®, Cooper, São Paulo, Brazil). On Day 7, CIDR® was removed and 2.5 mg of gonadorelina (Gestran-Plus®, Tecnopec, São Paulo, Brazil) was injected. Ovum pickup was performed 18 h after gonadorelina injection. Oocytes with expanded cumulus cell were then pooled and used as in vivo-matured oocytes (group 3: G3). Oocytes from all groups were denuded and frozen in liquid nitrogen. Pools of 10 oocytes for each group were subject to RNA extraction and reverse transcription. cDNA was amplified by real-time PCR using the beta-actin gene as the endogenous reference. The transcripts analyzed are encoded by TEA domain 2 (TEAD2), high mobility group N1 (HMGN), zygotic arrest 1 (ZAR1), maternal antigen that embryo requires (MATER), growth differentiation factor-9 (GDF9), and peroxiredoxin 1 (PRDX1) genes. Results were analyzed by REST software v.2 using the pair-wise, fixed reallocation randomization test. Data from G3 were used as calibrator. There was no difference (P > 0.05) on relative abundance of all transcripts between pools of oocytes matured in vitro or in vivo obtained from the same cows (G1 and G3, respectively). However, the relative abundance of GDF9 (0.22 ± 0.04-fold) was less (P < 0.05), whereas the relative abundance of TEAD2 transcripts (4.27 ± 2.14-fold) was greater (P < 0.05) for in vitro-matured oocytes obtained from slaugterhouse ovaries (G2) when compared with in vivo-matured oocytes (G3). No difference (P > 0.05) on relative abundance was found between G2 and G3 for the other genes. These data suggest that in vitro maturation does not alter the relative abundance of some transcripts stored into oocytes when compared with the ones stored in oocytes obtained from the same donors by means of multiple ovulation. Financial support was provided by CNPq and FAPEMIG.

236 EFFECT OF HEAT STRESS DURING OOCYTE MATURATION ON GENE EXPRESSION OF IN VITRO-FERTILIZED AND PARTHENOGENETIC BOVINE BLASTOCYSTS

Heat stress has been shown to have detrimental effects (41°C) during the first 12 h of in vitro maturation on bovine embryo development (Edwards JL and Hansen PJ 1996 Biol. Reprod. 55, 341-346). However, little is known about the effect on gene expression of in vitro-fertilized andparthenogenetic bovine embryos. This study evaluated the gene expression of in vitro-fertilized andparthenogenetic blastocysts derived fromheat-stressed oocytes. The transcripts evaluated were associated with genes encoding proteins involved in blastocoel formation [aquaporin (Aqp) 3 and Na+/K+-ATPase alpha 1; Watson AJ and Barcroft LC 2001 Frontiers Biosci. 6:d708-730] and cell viability (Bax and Peroxiredoxin 1; Van Delft MF and Huang DCS 2006 Cell Res. 16, 203-213; RaguS etal. 2007 PNAS104, 9747-9752). Oocytes were in vitro matured for 12 h at 41°C followed by 12 h at 38.5°C (heat-stressed oocytes; HS) or for 24 h at 38.5°C (non-heat-stressed oocytes; NHS) under 5% CO2. Heat-stressed and NHS oocytes were in vitro fertilized with Holstein sperm (HS-IVF and NHS-IVF subgroups, respectively) or activated with ionomycin and 6-DMAP (HS-PART and NHS-PART subgroups, respectively). Presumptive zygotes were cultured in CR2aa medium under 5% CO2, 5% O2, and 90% N2 at 38.5°C. Embryos at blastocyst stage with same quality grade for all subgroups were obtained from 3 different replicates and distributed in pools of 10 embryos for relative quantification of the target transcripts. RNA extraction and reverse transcription were performed and cDNA quantified by real-time PCR. Transcripts of H2a gene were used as endogenous control, and statistical analysis was performed by pair-wise, fixed reallocation randomization test. Gene expression comparisons were performed between HS-IVF and NHS-IVF, HS-PART and NHS-PART, NHS-PART and NHS-IVF, and HS-PART and HS-IVF subgroups. Blastocyst rate is shown as mean ± SEM and relative expression as n-fold. The heat stress on oocytes during in vitro maturation decreased (P < 0.05, ANOVA) the development of presumptive zygotes to blastocyst stage at Day 8 for in vitro-fertilized (19.9 ± 2.9% and 10.5 ± 2.0% for NHS-IVF and HS-IVF, respectively) and parthenogenetic (33.0 ± 1.8% and 22.8 ± 2.8% for NHS-PART and HS-PART, respectively) embryos. Embryos from the HS-IVF subgroup showed less (P < 0.01) expression of Na+/K+-ATPase alpha 1 (0.67-fold) than did NHS-IVF embryos, whereas no difference was found for others genes. Embryos from the HS-PART subgroup showed less (P < 0.01) expression of Aqp 3 (0.77-fold) and greater (P < 0.05) expression of Bax (1.40-fold) than did NHS-PART embryos. Expression of Aqp 3 was up-regulated (P < 0.01) in NHS-PART (1.42-fold) embryos when compared with NHS-IVF ones, whereas expression of Na+/K+-ATPase alpha 1 (1.42-fold), Bax (1.67-fold), and Peroxiredoxin 1 (1.40-fold) were up-regulated (P < 0.05) in HS-PART embryos when compared with HS-IVF embryos. In conclusion, heat stress on oocytes during in vitro maturation can affect the amount of transcripts of in vitro-fertilized andparthenogenetic blastocysts, suggesting a residual effect on gene expression of bovine embryos. Financial support was provided by CNPq and FAPEMIG.

Effects of extracellular calcium concentration on the glutamate release by bioactive glass (BG60S) preincubated osteoblasts

Glutamate released by osteoblasts sharing similarities with its role in neuronal transmission is a very new scientific concept which actually changed the understanding of bone physiology. Since glutamate release is a calcium (Ca(2+))-dependent process and considering that we have previously demonstrated that the dissolution of bioactive glass with 60% of silicon (BG60S) can alter osteoblast Ca(2+)-signaling machinery, we investigated whether BG60S induces glutamate secretion in osteoblasts and whether it requires an increase in intracellular Ca(2+). Here we showed that the extracellular Ca(2+) increase due to BG60S dissolution leads to an intracellular Ca(2+) increase in the osteoblast, through the activation of an inositol 1,4,5-triphosphate receptor (InsP(3)R) and a ryanodine receptor (RyR). Additionally, we also demonstrated that glutamate released by osteoblasts can be profoundly altered by BG60S. The modulation of osteoblast glutamate released by the extracellular Ca(2+) concentration opens a new window in the field of tissue engineering, since many biomaterials used for bone repair are able to increase the extracellular Ca(2+) concentration due to their dissolution products.

Technical improvement to prevent DNA degradation of Leptospira spp. in pulsed field gel electrophoresis

Leptospirosis is a public health problem. Infection with pathogenic Leptospira occurs by exposure to many environments and is traditionally associated with occupational risk activities. Pulsed-field gel electrophoresis was used to investigate the epidemiological relatedness among Leptospira isolates. However, analysis by PFGE yielded inconclusive data as a result of extensive DNA degradation. This degradation can be significantly reduced by the inclusion of thiourea in the electrophoresis buffer, improving the analysis of DNA banding patterns.

Anti-dsDNA antibodies in Brazilian patients of mainly African descent with systemic lupus erythematosus: lack of association with lupus nephritis

Renal disease is associated with morbidity and mortality in systemic lupus erythematosus (SLE) and anti-dsDNA antibodies with SLE immunopathogenesis. We investigated the dsDNA antibody profile of 84 Brazilian SLE patients, 27 with lupus nephritis. Thirty-six (39.1%) patients had dsDNA IgG antibodies shown in enzyme-linked immunosorbent assay (454.7 +/- 281.1 WHO units/mL), nine presenting renal disease. The following profile of dsDNA antibodies was demonstrated in Crithidia luciliae test: IgA (seven out of 36; 19.4%), IgG (22 out of 36, 66.1%); IgM (nine out of 36, 25.0%), and IgE (four out of 36, 11.1%). Two or three isotypes of dsDNA antibodies were observed in nine (25.0%) patients, while 11 (30.5%) were seronegative in the C. luciliae test. Patients with dsDNA antibodies had lower serum C3 and C4 when compared with SLE individuals without these immunoglobulins (P < 0.01 and P < 0.001, respectively). There was no association between any dsDNA antibody isotype and lupus kidney disease nor was anti-dsDNA IgM antibody associated with absence of nephritis.

253 DEVELOPMENTAL COMPETENCE OF BOVINE OOCYTES MATURED IN SERUM-FREE MEDIUM UNDER LOW OXYGEN TENSION

In vitro maturation (IVM) is a critical step in in vitro bovine embryo production. A number of factors can influence the IVM environment, such as media composition and protein supplementation. Serum and higher O2 tension have been shown to reduce embryo quality; however, little is known about the effects of serum and O2 tension during IVM on embryo quality and development. This study aimed to evaluate the effect of serum and O2 tension on IVM of bovine oocytes. Immature oocytes obtained from slaughterhouse ovaries were randomly distributed in 4 groups of IVM: G1 (n = 253), 0.1% polyvinyl alcohol (PVA) in air; G2 (n = 248), 10% inactivated estrous cow serum (ECS) in air; G3 (n = 270), 0.1% PVA under 5% O2; and G4 (n = 236), 10% ECS under 5% O2. In vitro maturation was performed with TCM-199 culture medium supplemented with 20 μg mL–1 FSH, under 5% CO2 at 38.5°C for 24 h. After maturation, oocytes were in vitro fertilized with 2.0 × 106 sperm mL–1 in Fert TALP medium, supplemented with heparin, for 20 h. Presumptive zygotes were denuded by vortexing and cultured in CR2aa medium with 2.5% fetal calf serum under 5% CO2 and 5% O2 at 38.5°C. Cleavage rate was evaluated 72 h postfertilization, and blastocyst rate and total cell number were evaluated 8 days postfertilization. Morphological classification of embryos was performed at Day 8 according to the International Embryo Transfer Society manual (1998). Cleavage, blastocyst, and grade 1 embryo rates were analyzed by chi-square, and total cell number was analyzed by ANOVA, with means compared by LSD. Results are presented as mean ± SEM. There was no difference (P > 0.05) in cleavage rates among G1, G2, and G4 (61.6, 65.3, and 57.6%, respectively), but cleavage rate was lower (P < 0.05) in G3 (52.5%). Blastocyst rates among G1, G3, and G4 (15.8, 17.7, and 20.3%, respectively) were similar (P > 0.05). However, blastocyst rate in G2 (25.0%) was higher (P < 0.05) than in G1 and G3, but was similar to G4 (P > 0.05). Total cell number was similar (P > 0.05) among G2 (194.1 ± 13.1), G3 (173.3 ± 9.0), and G4 (163.8 ± 8.7), but was lower (P < 0.05) in G1 (124.5 ± 11.4). The grade 1 embryo rate was lower (P < 0.05) in G1 (70.3%) than in G2 (89.5%), but was similar (P > 0.05) to G3 (77.0%) and G4 (83.9%). The results suggest that IVM with PVA in TCM-199 medium under 5% O2 can be performed without reducing embryo development and quality, when compared with ECS. On the other hand, oocyte developmental competence seems to be affected when IVM is performed with PVA under air conditions. Financial support: CNPq, FAPEMIG.

199 EFFECT OF PRODUCTION SYSTEM AND BREED ON RELATIVE GENE EXPRESSION IN BOVINE EMBRYOS

Embryos produced in vivo and in vitro show morphological and developmental differences, which can be related to culture environment. Nevertheless, there are a few studies showing the effect of in vitro environment on embryos from different bovine subspecies, such as Gyr (Bos indicus) and Holstein (Bos taurus). The aim of this study was to evaluate the relative abundance of aquaporin 3 (AQP3) and ATPase-α1 (Na/K-ATPase alpha 1) transcripts in blastocysts produced in vivo or in vitro from Gyr and Holstein cattle. The production system effect (in vivo × in vitro) for Gyr cattle and the breed effect (Holstein × Gyr) for in vitro-produced embryos were evaluated. For each group, blastocysts (n = 15) distributed in 3 pools were used for RNA extraction (RNeasy MicroKit, Qiagen, Valencia, CA), followed by RNA amplification (Messageamp II amplification kit, Ambion-Applied Biosystems, Foster City, CA) and reverse transcription (SuperScript III First-Stand Synthesis Supermix, Invitrogen, Carlsbad, CA). The cDNA obtained were submitted to real-time PCR, using the H2a gene as endogenous control, and analyzed with REST software© using the pair wise fixed reallocation randomization Test. There was no difference (P > 0.05) in gene expression for AQP3 and ATPase-α1 between in vivo- and in vitro-produced Gyr embryos, although the results suggest that the APQ3 gene was down-regulated (0.81 ± 0.31) and the ATPase-α1 gene was up-regulated (1.20 ± 0.65) in embryos produced in vitro. For breed effect within in vitro production system, ATPase-α1 gene was down-regulated in Holstein (0.56 ± 0.30) when compared with Gyr embryos (P < 0.05). The same trend was observed for AQP3 (0.58 ± 0.25), but with no difference (P > 0.05). In conclusion, the data suggest that embryo production system does not interfere with the transcript amount of the genes studied for Gyr cattle; however, the in vitro production system may have different effects on gene expression according to embryo breed. Other genes should be evaluated for a better understanding of these differences. Financial support: CNPq, Fapemig.

266 WHOLE GENOME AMPLIFICATION ON BLASTOMERS OF POST-BIOPSY BOVINE EMBRYO

Biopsy of embryos is very useful for choosing the desired sex and for production of cloned and transgenic livestock. However, only a small amount of genomic DNA is available to perform genetic studies. Alternatively, methodologies using whole genome amplification (WGA) have been developed. The aims of this study were to evaluate the effect of WGA on blastomeres removed from 8- to 16-cell bovine embryos and to determine the sex of blastomeres. Oocytes obtained from slaughterhouse ovaries were in vitro matured and fertilized. On the fourth day after fertilization, 8- to 16-cell bovine embryos were biopsied, and one-fourth of an embryo was removed. The blastomeres (n = 56) were submitted to WGA followed by PCR. Prior to the whole genome amplification, male and female bovine DNA samples were serially diluted (30 ng μL–1, 3.0 ng μL–1, 0.3 ng μL–1, 0.03 ng μL–1, 0.003 ng μL–1, 0.0003 ng μL–1) and embryos of various development stages (2, n = 6; 4–7, n = 5; ≥8-cell, n = 5; blastocyst n = 27) were used to standardize PCR protocols and set the amplification limits. To digest the cellular cytoplasm and release the genomic DNA, embryos and blastomeres were submitted a 3 mg mL–1 proteinase K before PCR. Next, blastomeres were submitted to the GenomiPhi DNA Amplification Kit (GE Healthcare) according to manufacturer’s instructions. The product (1 μL) was electrophoresed on a 1% agarose gel stained with 3.0 μg mL–1 ethidium bromide. The reaction mixture was added to the material to be amplified (2 mm MgCl2, 5X PCR buffer, 0.2 mm each dNTPs, 0.05 U μL–1 GoTaq DNA polymerase, 0.25 μm of primer). The products were submitted to electrophoresis on 8% polyacrilamide gel and stained with silver nitrate procedure. The chi-square test was used for statistic evaluation of the results to test the WGA efficiency and to determine the sex rates of bovine embryos and biopsied samples submitted to PCR. It was possible to achieve 98% efficiency in amplifying blastomeres using the WGA kit. Amplified samples showed approximately 400 ng of DNA generated from an estimated initial amount of 12 pg of DNA resulting from two cells per embryo. In whole embryos from different stages, no diffference was detected in the proportion of sexes (P > 0.05). However, a greater number of female samples was noted in biopsied material (76%, 25/33) (P < 0.05). PCR efficiency in blastocysts (93%, 2/27) was statistically greater (P < 0.05) than embryos in early stages of development (83%, 5/6), and biopsied material to 2, 4–7 and ≥8-cell (40%, 2/5; 60%, 3/5; and 59%, 33/56; respectively). These differences could be related to a sex-chromosomal mosaicism or absence of a nucleus in biopsied samples. The WGA creates a DNA stock sample that could be used for various gene profiling and sex determination analyses. Financial support: Fapemig, CNPq.

Novilhos nelore suplementados em pastagens: consumo, desempenho e digestibilidade

Objetivou-se com este estudo verificar os efeitos de diferentes níveis de suplementação em pastagens sobre o consumo de forragem, o desempenho animal e a digestibilidade dos nutrientes em novilhos Nelore na fase de terminação em pastagens no Sudoeste da Bahia. A parte de campo foi implantada numa área de 52,0 ha, dividida em oito piquetes de aproximadamente 6,5 ha cada, subdivididas em setores com aguada central. Testaram-se quatro níveis de suple-mentação em função do peso vivo: T00, T03, T06 e T09. Na fase de suplementação, houve efeito decrescente sobre o consumo da pastagem e da fibra em detergente neutro. Houve efeito linear crescente em função dos níveis de suplementação para os consumos de proteína bruta, extrato etéreo, carboidrato não-fibroso, nutrientes digestíveis totais, energia digestível e energia bruta. No período chuvoso, nenhuma variável foi alterada. O desempenho animal apresentou efeito linear crescente na fase de suplementação e manteve-se inalterado no período chuvoso. A conversão alimentar e a eficiência alimentar foram alteradas positivamente pela inclusão dos níveis de suplementação. Houve efeito linear crescente sobre os coeficientes de digestibilidade da matéria seca, proteína bruta e carboidratos não-fibrosos. A digestibilidade da fibra em detergente neutro apresentou efeito quadrático enquanto a do extrato etéreo não foi alterada. No período chuvoso, nenhuma das variáveis foi alterada.

141 BIOPSY TECHNIQUE IN BOVINE EMBRYOS PRODUCED IN VITRO AT EARLY STAGES OF DEVELOPMENT: EVALUATION OF QUALITY AND DEVELOPMENT CAPACITY

One of the causes of embryo mortality is chromosome abnormalities that occur during gametogenesis, fertilization, and embryo early development. Thus, a combination of morphological standards and techniques of molecular analyses could identify abnormal embryos. Preimplantation genetic diagnosis (PGD) is an emergent technology for use with farm animal embryos. With this procedure, blastomeres are removed by the biopsy of embryos at the 8- to 16-cell stage to provide cells for analyses of chromosome abnormalities prior to transfer. The aim of this study was to evaluate the effect of biopsy in bovine 8- to 16-cell embryos fertilized in vitro on embryo quality and subsequent development in vitro. A group of 706 oocytes were obtained from slaughterhouse ovaries, matured, and fertilized in vitro at 38.8�C with 95% humidified air and 5% CO2. The zygotes were semi-denuded and cultured in CR2aa medium under the same conditions as for in vitro fertilization. The rate of cleavage was 78.20%. Three days after fertilization, part of the 8- to 16-cell (298/706) embryos were distributed randomly across two groups: control (n = 103) and biopsy (n = 92) of blastomeres, and then returned to in vitro embryo culture to evaluate development until the blastocyst stage and the capacity to hatch. The amount of cells removed was one-fourth of the embryo. The blastocyst rate was evaluated on Day 8 after fertilization and the hatching rate on Day 10. Embryo morphology and quality were evaluated as previously described in the International Embryo Transfer Society manual (1998). To evaluate overall quality, embryos were stained on the 10th day of culture and the blastomeres were counted with the imaging software AxioVision 3.1 (Carl Zeiss, Feldbach, Switzerland). The blastocyst rate was analyzed by treatment groups with the chi-square test and the number of cells/embryo was analyzed by ANOVA with SAS (SAS Institute, Inc., Cary, NC, USA). The percentage of 8- to 16-cell embryos that developed to the blastocyst stage was similar (P > 0.05) between the control (66.0%, 68/103) and the biopsied (53.3%, 49/92) groups. Furthermore, no difference was noted in the hatching rates between the control group and the biopsied group (42.6%, 29/42 v. 44.9%, 22/49, respectively). Overall, no impact was detected on embryo quality from embryo biopsy with no difference in mean (�SE) blastocyst cell number between the control group (blastocysts: 67.1 � 3.1; expanded blastocysts: 100.7 � 6.9; hatched blastocysts: 189.9 � 16.1) and the biopsied group (blastocysts: 61.1 � 5.5; expanded blastocysts: 121.87 � 10.6; hatched blastocysts: 187.3 � 18.5). In conclusion, the biopsy used on 8- to 16-cell bovine IVF-derived bovine embryos does not affect the subsequent embryo development and number of cells/embryo or blastocyst, showing that it can be used to provide genetic material for preimplantation genetic diagnosis without affecting embryo quality. This work was supported financially by FAPEMIG.

BG60S dissolution interferes with osteoblast calcium signals

We investigated the influence of extracellular calcium concentration, caused by the dissolution of a bioactive glass with 60% of silicon (BG60S), on intracellular calcium (Ca(i) (2 +)) signals and expression of inositol 1, 4, 5-triphosphate receptors (InsP(3)R) in primary culture of osteoblasts. We found that BG60S caused an increase in Ca(i) (2 +) signals in this cell type. Additionally, osteoblasts pre-incubated in the presence of BG60S showed an increase in Ca(i) (2 +) when cells were stimulated with vasopressin. On the other hand, a decrease in Ca(i) (2 +) signals were observed in osteoblasts pre-treated with BG60S and stimulated with KCl. We furher found that in osteoblasts, the type I InsP(3)R is preferentially distributed in the nucleus while the type II InsP(3)R in the cytoplasm. Preincubation of osteoblasts with BG60S altered the receptor expression level, increasing the type I InsP(3)R in the nucleus and decreasing type II InsP(3)R in the cytosol. Together, our results showed that in osteoblasts, BG60S increased Ca(i) (2 +)signals and altered Ca(i) (2 +) machinery.

Preparation of bioactive glass-polyvinyl alcohol hybrid foams by the sol-gel method

A new class of materials based on inorganic and organic species combined at a nanoscale level has received large attention recently. In this work the idea of producing hybrid materials with controllable properties is applied to obtain foams to be used as scaffolds for tissue engineering. Hybrids were synthesized by reacting poly(vinyl alcohol) in acidic solution with tetraethylorthosilicate. The inorganic phase was also modified by incorporating a calcium compound. Hydrated calcium chloride was used as precursor. A surfactant was added and a foam was produced by vigorous agitation, which was cast just before the gel point. Hydrofluoric acid solution was added in order to catalyze the gelation. The foamed hybrids were aged at 40 degrees C and vacuum dried at 40 degrees C. The hybrid foams were analyzed by Scanning Electron Microscopy, Mercury Porosimetry, Nitrogen Adsorption, X-ray Diffraction and Infra-red Spectroscopy. The mechanical behavior was evaluated by compression tests. The foams obtained had a high porosity varying from 60 to 90% and the macropore diameter ranged from 30 to 500 microm. The modal macropore diameter varied with the inorganic phase composition and with the polymer content in the hybrid. The surface area and mesopore volume decreased as polymer concentration increased in the hybrids. The strain at fracture of the hybrid foams was substantially greater than pure gel-glass foams.

Primary osteoblast cell response to sol-gel derived bioactive glass foams

Bioactive glass macroporous structures were developed in this work to be used as scaffolds for bone tissue engineering applications. A sol-gel route was used to obtain glass foams with the introduction of a gas phase in the solution and by vigorous agitation of the sol-gel solution that contains a foam agent. Stable and homogeneous foams were formed near the gelation point, which were than dried and heat-treated. Macroporous structures with interconnected pores of up to 500 mu m, porosity as high as 88% and specific surface area of 92 m(2)/g were obtained. The porous glasses were tested in osteoblast cultures to evaluate adhesion, proliferation, collagen and alkaline phosphatase production. Osteoblast proliferation was higher in the presence of the foams as well as was the collagen secretion, when compared to control. The alkaline phosphatase production was not altered. Viable osteoblasts could be seen inside the foams, suggesting that the produced porous glass foams are a promising materials for bone repair, since it provides a good environment for the adhesion and proliferation of osteoblasts.

Effect of biphasic calcium phosphate on human macrophage functions in vitro

Bioceramics may initiate several and complex biological reactions in host tissues. The cell-biomaterial interaction can determine macrophage activation that may elicit and sustain inflammatory response at the implant site. The current study describes some of the in vitro phenomena regarding the effect of surface reactivity of biphasic calcium phosphate (BCP) granules on human macrophages locomotion and secretion. X-ray diffraction analysis indicated that the synthesized ceramic presented 80% hydroxyapatite and 20% tricalcium phosphate. When BCP was put in contact with human macrophage cells, we observed that cells and BCP granules attached to each other. Cells attached to BCP presented a higher intracellular free Ca(2+) concentration compared with nonattached neighbors and secreted calcium phosphate particles into the medium. Energy dispersive X-ray analysis showed that the secreted particles presented a calcium/phosphorus ratio of 1.64 +/- 0.05, similar to hydroxyapatite. We propose that the secreted particles create a transition zone that allows further macrophage adhesion.

Localisation of wild-type and DeltaF508-CFTR in nasal epithelial cells

Wild-type and the DeltaF508 mutation of the cystic fibrosis transmembrane conductance regulator (DeltaF508-CFTR) were localised by confocal imaging in DeltaF508/DeltaF508 native airway epithelial cells using a well-characterised CFTR antibody. Surface nasal epithelial cells from three control and three CF individuals were obtained from nasal brushings. Cells were fixed, permeabilised and incubated with first antibody for 18 h at 4 degrees C. Following labelling with second antibody, cells were viewed with the confocal microscope. Wild-type CFTR was localised predominantly apically, whereas DeltaF508-CFTR was located mainly inside the cell in a region close to the nucleus. Incubation of cells with MPB-07 (250 microM) at 37 degrees C for 2 h resulted in pronounced movement of DeltaF508-CFTR to the cell periphery, but did not change the localisation of wild-type CFTR. The results show that DeltaF508-CFTR is mislocalised in native nasal epithelial cells and that its distribution is altered in response to the new CFTR activator, MPB-07. The findings should lead to development of a rational drug treatment for CF patients carrying the DeltaF508 mutation.

The CFTR-mediated protein secretion defect: pharmacological correction

The cystic fibrosis transmembrane conductance regulator (CFTR) mediates secretion of mucins and serous proteins. The aim was to correct pharmacologically the CFTR defect in protein secretion in airway gland cells and so to correct the viscous mucous secretions in cystic fibrosis (CF) airways and lungs. The strategies tested included direct activation of CFTR, bypass of CFTR-mediated protein secretion and movement of the mutated form of CFTR (DeltaF(508)-CFTR) to the cell membrane. Compounds related to 3-isobutyl-1-methylxanthine (IBMX), including a selective type-IV phosphodiesterase inhibitor and the adenosine receptor antagonists 8-cyclopentyltheophylline (CPT) and 8-cyclopentyl-1,3-dipropylxanthine (CPX), corrected the defective beta-adrenergic stimulation of mucin secretion in CFTR antibody-inhibited submandibular gland cells. CPT also corrected lactoferrin secretion in DeltaF(508)/DeltaF(508)-CFTR nasal gland cells. The data suggest that correction of CFTR protein secretion activity is not mediated by excessive increase in cyclic AMP, involves direct interaction with CFTR but does not require increase in CFTR Cl(-) channel activity. Regulated glycoprotein secretion was characterised in the airway gland cell line Calu-3 to investigate whether a CFTR bypass is present. Studies of DeltaF(508)-CFTR trafficking using confocal imaging showed that some DeltaF(508)-CFTR colocalised with the apical membrane protein CD59; however a large amount was mislocalised within the cell. The results showing pharmacological correction of the defective CFTR-mediated protein secretion afford promise for the development of a rational drug therapy for CF patients.

Synthesis, spectra and photophysics of some free base tetrafluoroalkyl and tetrafluoroaryl porphyrins with potential applications in imaging

The synthesis, characterization and photophysical properties of two perfluoroalkyl (5,10,15,20-tetrakis-[trifluoromethyl]- and [heptafluoropropyl]-porphyrin) and two perfluoroaryl (5,10,15,20-tetrakis-[2,6-difluorophenyl]- and [pentafluorophenyl]-porphyrin) are described, with reference to their potential in both photodynamic therapy (PDT) and in vivo imaging by fluorescence and 19F nuclear magnetic resonance spectroscopy. Absorption and fluorescence spectra, fluorescence lifetimes and triplet-singlet difference spectra are reported. Triplet yields have been obtained by flash photolysis and pulse radiolysis, whereas yields of sensitized singlet oxygen formation have been determined by time-resolved phosphorimetry. All four compounds show high yields of triplet formation and singlet oxygen sensitization. The spectral properties, stability and attractive solubility characteristics of the perfluoroalkyl derivatives make them particularly suitable candidates for future study for applications in PDT.

Correction of delF508-CFTR activity with benzo(c)quinolizinium compounds through facilitation of its processing in cystic fibrosis airway cells

A number of genetic diseases, including cystic fibrosis, have been identified as disorders of protein trafficking associated with retention of mutant protein within the endoplasmic reticulum. In the presence of the benzo(c)quinolizinium drugs, MPB-07 and its congener MPB-91, we show the activation of cystic fibrosis transmembrane conductance regulator (CFTR) delF508 channels in IB3-1 human cells, which express endogenous levels of delF508-CFTR. These drugs were without effect on the Ca2+-activated Cl– transport, whereas the swelling-activated Cl– transport was found altered in MPB-treated cells. Immunoprecipitation and in vitro phosphorylation shows a 20% increase of the band C form of delF508 after MPB treatment. We then investigated the effect of these drugs on the extent of mislocalisation of delF508-CFTR in native airway cells from cystic fibrosis patients. We first showed that delF508 CFTR was characteristically restricted to an endoplasmic reticulum location in approximately 80% of untreated cells from CF patients homozygous for the delF508-CFTR mutation. By contrast, 60-70% of cells from non-CF patients showed wild-type CFTR in an apical location. MPB-07 treatment caused dramatic relocation of delF508-CFTR to the apical region such that the majority of delF508/delF508 CF cells showed a similar CFTR location to that of wild-type. MPB-07 had no apparent effect on the distribution of wild-type CFTR, the apical membrane protein CD59 or the ER membrane Ca2+,Mg-ATPase. We also showed a similar pharmacological effect in nasal cells freshly isolated from a delF508/G551D CF patient. The results demonstrate selective redirection of a mutant membrane protein using cell-permeant small molecules of the benzo(c)quinolizinium family and provide a major advance towards development of a targetted drug treatment for cystic fibrosis and other disorders of protein trafficking.

Referral pattern of leptospirosis cases during a large urban epidemic of dengue

During heavy seasonal rainfall in 1996, concurrent epidemics of dengue and leptospirosis occurred in an urban center in northeastern Brazil. We interviewed 110 cases of leptospirosis hospitalized a median of seven days after the onset of illness to evaluate the impact of the dengue epidemic on the triage of suspected leptospirosis from ambulatory clinics to the infectious disease reference hospital. Within the first three days of illness, 46 (42%) cases sought their first medical evaluation, and 28 (61% of 46) received a diagnosis of dengue. Dengue diagnoses were associated with a median of five days delay in referral to the infectious disease hospital. Patients who reported initial diagnoses of dengue were more likely than other patients to have required admission to the intensive care unit (odds ratio [OR] = 2.7, 95% confidence interval [CI] = 0.8-9.5) and to have died during hospitalization (OR = 5.1, 95% CI = 0.8-55.0). These findings indicate that diagnostic confusion between the early symptoms of leptospirosis and dengue may have contributed to the high mortality observed during the leptospirosis epidemic.

Ligand binding and the catalytic reaction of cytochrome caa(3) from the thermophilic bacterium Rhodothermus marinus

The ligand-binding dynamics and the reaction with O(2) of the fully (five-electron) reduced cytochrome caa(3) from the thermohalophilic bacterium Rhodothermus (R.) marinus were investigated. The enzyme is a proton pump which has all the residues of the proton-transfer pathways found in the mitochondrial-like enzymes conserved, except for one of the key elements of the D-pathway, the helix-VI glutamate [Glu(I-286), R. sphaeroides numbering]. In contrast to what has been suggested previously as general characteristics of thermophilic enzymes, during formation of the R. marinus caa(3)-CO complex, CO binds weakly to Cu(B), and is rapidly (k(Ba) = 450 s(-1)) trapped by irreversible (K(Ba) = 4.5 x 10(3)) binding to heme a(3). Upon reaction of the fully reduced enzyme with O(2), four kinetic phases were resolved during the first 10 ms after initiation of the reaction. On the basis of a comparison to reactions observed with the bovine enzyme, these phases were attributed to the following transitions between intermediates (pH 7.8, 1 mM O(2)): R --> A (tau congruent with 8 micros), A --> P(r) (tau congruent with 35 micros), P(r) --> F (tau congruent with 240 micros), F --> O (tau congruent with 2.5 ms), where the last two phases were associated with proton uptake from the bulk solution. Oxidation of heme c was observed only during the last two reaction steps. The slower transition times as compared to those observed with the bovine enzyme most likely reflect the replacement of Glu(I-286) of the helix-VI motif -XGHPEV- by a tyrosine in the R. marinus enzyme in the motif -YSHPXV-. The presence of an additional, fifth electron in the enzyme was reflected by two additional kinetic phases with time constants of approximately 20 and approximately 720 ms during which the fifth electron reequilibrated within the enzyme.

The succinate dehydrogenase from the thermohalophilic bacterium Rhodothermus marinus: redox-Bohr effect on heme bL

The succinate dehydrogenase from the thermohalophilic bacterium Rhodothermus marinus is a member of the succinate:menaquinone oxidoreductases family. It is constituted by three subunits with apparent molecular masses of 70, 32, and 18 kDa. The optimum temperature for succinate dehydrogenase activity is 80 degrees C, higher than the optimum growth temperature of R. marinus, 65 degrees C. The enzyme shows a high affinity for both succinate (Km = 0.165 mM) and fumarate (Km = 0.10 mM). It contains the canonical iron-sulfur centers S1, S2, and S3, as well as two B-type hemes. In contrast to other succinate dehydrogenases, the S3 center has an unusually high reduction potential of +130 mV and is present in two different conformations, one of which presents an unusual EPR signal with g values at 2.035, 2.009, and 2.001. The apparent midpoint reduction potentials of the hemes, +75 and -65 mV at pH 7.5, are also higher than those reported for other enzymes. The heme with the lower potential (heme bL) presents a considerable dependence of the reduction potential with pH (redox-Bohr effect), having a pKa(OX) = 6.5 and a pKa(red) = 8.7. This behavior is consistent with the proposal that in these enzymes menaquinone reduction occurs close to heme bL, near to the periplasmic side of the membrane, and involving dissipation of the proton transmembrane gradient.

A novel scenario for the evolution of haem-copper oxygen reductases

The increasing sequence information on oxygen reductases of the haem-copper superfamily, together with the available three-dimensional structures, allows a clear identification of their common, functionally important features. Taking into consideration both the overall amino acid sequences of the core subunits and key residues involved in proton transfer, a novel hypothesis for the molecular evolution of these enzymes is proposed. Three main families of oxygen reductases are identified on the basis of common features of the core subunits, constituting three lines of evolution: (i) type A (mitochondrial-like oxidases), (ii) type B (ba3-like oxidases) and (iii) type C (cbb3-type oxidases). The first group can be further divided into two subfamilies, according to the helix VI residues at the hydrophobic end of one of the proton pathways (the so-called D-channel): (i) type A1, comprising the enzymes with a glutamate residue in the motif -XGHPEV-, and (ii) type A2, enzymes having instead a tyrosine and a serine in the alternative motif -YSHPXV-. This second subfamily of oxidases is shown to be ancestor to the one containing the glutamate residue, which in the Bacteria domain is only present in oxidases from Gram-positive or purple bacteria. It is further proposed that the Archaea domain acquired terminal oxidases by gene transfer from the Gram-positive bacteria, implying that these enzymes were not present in the last common ancestor before the divergence between Archaea and Bacteria. In fact, most oxidases from archaea have a higher amino acid sequence identity and similarity with those from bacteria, mainly from the Gram-positive group, than with oxidases from other archaea. Finally, a possible relation between the dihaemic subunit (FixP) of the cbb3 oxidases and subunit II of caa3 oxidases is discussed. As the families of haem-copper oxidases can also be identified by their subunit II, a parallel evolution of subunits I and II is suggested.

Gene cluster of Rhodothermus marinus high-potential iron-sulfur Protein: oxygen oxidoreductase, a caa(3)-type oxidase belonging to the superfamily of heme-copper oxidases

The respiratory chain of the thermohalophilic bacterium Rhodothermus marinus contains an oxygen reductase, which uses HiPIP (high potential iron-sulfur protein) as an electron donor. The structural genes encoding the four subunits of this HiPIP:oxygen oxidoreductase were cloned and sequenced. The genes for subunits II, I, III, and IV (named rcoxA to rcoxD) are found in this order and seemed to be organized in an operon of at least five genes with a terminator structure a few nucleotides downstream of rcoxD. Examination of the amino acid sequence of the Rcox subunits shows that the subunits of the R. marinus enzyme have homology to the corresponding subunits of oxidases belonging to the superfamily of heme-copper oxidases. RcoxB has the conserved histidines involved in binding the binuclear center and the low-spin heme. All of the residues proposed to be involved in proton transfer channels are conserved, with the exception of the key glutamate residue of the D-channel (E(278), Paracoccus denitrificans numbering). Analysis of the homology-derived structural model of subunit I shows that the phenol group of a tyrosine (Y) residue and the hydroxyl group of the following serine (S) may functionally substitute the glutamate carboxyl in proton transfer. RcoxA has an additional sequence for heme C binding, after the Cu(A) domain, that is characteristic of caa(3) oxidases belonging to the superfamily. Homology modeling of the structure of this cytochrome domain of subunit II shows no marked electrostatic character, especially around the heme edge region, suggesting that the interaction with a redox partner is not of an electrostatic nature. This observation is analyzed in relation to the electron donor for this caa(3) oxidase, the HiPIP. In conclusion, it is shown that an oxidase, which uses an iron-sulfur protein as an electron donor, is structurally related to the caa(3) class of heme-copper cytochrome c oxidases. The data are discussed in the framework of the evolution of oxidases within the superfamily of heme-copper oxidases.

Properties of CFTR activated by the xanthine derivative X-33 in human airway Calu-3 cells

The pharmacological activation of the cystic fibrosis gene protein cystic fibrosis transmembrane conductance regulator (CFTR) was studied in human airway epithelial Calu-3 cells, which express a high level of CFTR protein as assessed by Western blot and in vitro phosphorylation. Immunolocalization shows that CFTR is located in the apical membrane. We performed iodide efflux, whole cell patch-clamp, and short-circuit recordings to demonstrate that the novel synthesized xanthine derivative 3, 7-dimethyl-1-isobutylxanthine (X-33) is an activator of the CFTR channel in Calu-3 cells. Whole cell current activated by X-33 or IBMX is linear, inhibited by glibenclamide and diphenylamine-2-carboxylate but not by DIDS or TS-TM calix[4]arene. Intracellular cAMP was not affected by X-33. An outwardly rectifying Cl(-) current was recorded in the absence of cAMP and X-33 stimulation, inhibited by DIDS and TS-TM calix[4]arene. With the use of short-circuit recordings, X-33 and IBMX were able to stimulate a large concentration-dependent CFTR transport that was blocked by glibenclamide but not by DIDS. Our results show that manipulating the chemical structure of xanthine derivatives offers an opportunity to identify further specific activators of CFTR in airway cells.

Total synthesis of 16-desmethylepothilone B, epothilone B10, epothilone F, and related side chain modified epothilone B analogues

The macrolactonization-based strategy for the total synthesis of epothilones has been streamlined and improved to a high level of efficiency and stereoselectivity. This strategy has been applied to the construction of vinyl iodide 19 which served as a common intermediate for the synthesis of a series of natural and designed epothilones including an epothilone B10 (3), epothilone F (5), 16-desmethylepothilone B (14), pyridine epothilones 57a-57g, dimeric epothilones 59 and 61, and benzenoid epothilones 63a-63g.

Chemical synthesis and biological properties of pyridine epothilones

BACKGROUND

Numerous analogs of the antitumor agents epothilones A and B have been synthesized in search of better pharmacological profiles. Insights into the structure-activity relationships within the epothilone family are still needed and more potent and selective analogs of these compounds are in demand, both as biological tools and as chemotherapeutic agents, especially against drug-resistant tumors.

RESULTS

A series of pyridine epothilone B analogs were designed, synthesized and screened. The synthesized compounds exhibited varying degrees of tubulin polymerization and cytotoxicity properties against a number of human cancer cell lines depending on the location of the nitrogen atom and the methyl substituent within the pyridine nucleus.

CONCLUSIONS

The biological screening results in this study established the importance of the nitrogen atom at the ortho position as well as the beneficial effect of a methyl substituent at the 4- or 5-position of the pyridine ring. Two pyridine epothilone B analogs (i.e. compounds 3 and 4) possessing higher potencies against drug-resistant tumor cells than epothilone B, the most powerful of the naturally occurring epothilones, were identified.

The caa(3) terminal oxidase of Rhodothermus marinus lacking the key glutamate of the D-channel is a proton pump

The thermohalophilic bacterium Rhodothermus marinus expresses a caa(3)-type dioxygen reductase as one of its terminal oxidases. The subunit I amino acid sequence shows the presence of all the essential residues of the D- and K-proton channels, defined in most heme-copper oxidases, with the exception of the key glutamate residue located in the middle of the membrane dielectric (E278 in Paracoccus denitrificans). On the basis of homology modeling studies, a tyrosine residue (Y256, R. marinus numbering) has been proposed to act as a functional substitute [Pereira, M. M., Santana, M., Soares, C. M., Mendes, J., Carita, J. N., Fernandes, A. S., Saraste, M., Carrondo, M. A., and Teixeira, M. (1999) Biochim. Biophys. Acta 1413, 1-13]. Here, R. marinus caa(3) oxidase was reconstituted in liposomes and shown to operate as a proton pump, translocating protons from the cytoplasmic side of the bacterial inner membrane to the periplasmatic space with a stoichiometry of 1H(+)/e(-), as in the case in heme-copper oxidases that contain the glutamate residue. Possible mechanisms of proton transfer in the D-channel with the participation of the tyrosine residue are discussed. The observation that the tyrosine residue is conserved in several other members of the heme-copper oxidase superfamily suggests a common alternative mode of action for the D-channel.

Heme centers of Rhodothermus marinus respiratory chain. Characterization of its cbb3 oxidase

Rhodothermus (R.) marinus, a thermohalophilic gram-negative, and strict aerobic bacterium, has a rather distinct respiratory chain, containing a caa3 terminal oxidase, a novel cytochrome bc complex and a HiPIP, which is an electron carrier between this complex and a terminal oxidase (Pereira et al (1999a, c). To further elucidate this unusual respiratory system, its membrane-bound heme centers were characterized by visible and EPR spectroscopies as well as by redox potentiometry. Rhodothermus marinus contains mostly B- and C-type hemes; a small amount of A-type heme is also detected. The heme centers have relatively low reduction potentials, ranging from ca. +250 to -60 mV, at pH 7. A Rieske-type center was not detected, suggesting the absence of a canonical complex III. The major terminal oxidase expressed by R. marinus is a cbb3-type oxidase. Its presence is in agreement with molecular biology studies, which reveal the existence of a gene encoding for a FixN-type oxidase. The oxidase was partially purified and appears to have five subunits, with apparent molecular masses of 64, 57, 36, 26 (C-type heme subunit), and 13 kDa. It contains two low-spin heme C centers, one high-, and one low-spin heme B centers. A full description of the equilibrium redox behavior of the heme centers was obtained for a cbb3 oxidase for the first time. The optical spectrum for each heme center and the corresponding reduction potentials were determined at pH 7: + 195 (heme C), +120 (heme B), -50 (heme C), and -50 mV (heme B3).

A clonal subpopulation of Leptospira interrogans sensu stricto is the major cause of leptospirosis outbreaks in Brazil

Leptospira is a highly diverse genus comprising many species and serogroups in Brazil as well as all over the world. However, a study by arbitrarily primed PCR of 44 leptospiral strains isolated from humans during three different outbreaks in Brazilian urban centers reveals that 43 of 44 isolates exhibit very similar fingerprints. Analysis of these isolates indicates that they belong to a clonal subpopulation of Leptospira interrogans sensu stricto.

A cyclic nucleotide PDE5 inhibitor corrects defective mucin secretion in submandibular cells containing antibody directed against the cystic fibrosis transmembrane conductance regulator protein

A selective cyclic nucleotide PDE5 inhibitor corrected the defective mucin secretion response to the beta-agonist isoproterenol in submandibular acinar cells inhibited by antibody directed against the cystic fibrosis transmembrane conductance regulator. The PDE5 inhibitor was as effective as cpt-cyclic AMP or a selective PDE4 inhibitor. However, the PDE5 inhibitor had no effect on basal or isoproterenol-stimulated cyclic AMP levels and did not stimulate mucin secretion. The results showing, for the first time, correction of the CFTR mucin secretion defect by a PDE5 inhibitor, which may involve cyclic GMP, will have a major impact in development of a rational drug treatment for cystic fibrosis.