Ação anti-helmíntica do extrato hidroalcóolico da raiz da Tarenaya spinosa (Jacq.) Raf. no controle de Haemonchus contortus em ovinos

Para investigar o potencial anti-helmíntico do extrato hidroalcóolico da raiz de Tarenaya spinosa, como alternativa no controle do nematóide gastrintestinal Haemonchus contortus de ovinos, foram realizados testes in vitro com Artemia salina, em seguida, sobre coproculturas contendo ovos do helminto, avaliando a ação ovicida e larvicida do extrato. Após os testes preliminares, foi realizado o teste in vivo em 20 ovinos machos os quais foram divididos em quatro tratamentos Grupo 1: ivermectina 1%; Grupo 2: sem tratamento; Grupo 3: extrato hidroalcóolico de T. spinosa 150μg/mL; Grupo 4: extrato hidroalcóolico de T. spinosa 300μg/mL, amostras de fezes e de sangue foram coletadas para exames parasitológicos e hematológicos. No teste in vitro, a toxicidade frente a A. salina foi de 150μg/mL, obteve-se eficiência de 81,53% sobre ovos e larvas do H. contortus. No teste in vivo, a avaliação da eficácia dos tratamentos foi realizada pelo teste de redução na contagem de ovos fecais (RCOF), os grupos tratados com Ivermectina e T. spinosa a 150μg/mL e 300μg/mL obtiveram os melhores resultados, reduzindo o OPG após 28 dias em 40,6, 41 e 40,2% respectivamente, revelando assim seu potencial fitoterápico para fins de controle de nematódeos gastrintestinais em ovinos.

Estudo da atividade anti-helmíntica do extrato etanólico de Jatropha mollissima (Pohl) Baill. (Euphorbiaceae) sob Haemonchus contortus em ovinos no semiárido paraibano

Objetivou-se com o presente trabalho, avaliar o efeito anti-helmíntico de Jatropha mollissima por meio de experimentos in vitro e in vivo. Inicialmente foi investigada a concentração de extrato com efeito bioativo, pelo teste de evolução da toxicidade do extrato etanólico de J. mollissima sobre o microcrustáceo Artemia salina, obtendo uma CL50 de 660,80µg/ml, que foi testada em coproculturas contendo larvas infectantes de Haemonchus contortus e em animais para a verificação da redução do OPG. Para o teste in vivo o extrato foi dissolvido em água para se obter as concentrações 660,80µg/ml e 1321,6µg/ml, foram coletadas fezes semanalmente e sangue quinzenalmente. Como resultados dos testes in vitro, o extrato etanólico do caule de Jatropha mollissima mostrou-se tóxico sobre A. salina, com CL50 abaixo de 1000 µg/ml e inibiu a eclosão de ovos e o desenvolvimento de larvas de H. contortus, apresentando uma eficiência de 70,77%. O teste in vivo revelou que o extrato é também eficaz em ovinos, com redução significativa na contagem de OPG após 28 dias de experimento, 47 e 44% de redução nos grupos tratados com o extrato, 7,5% no grupo de animais não tratados e 40,6% com a ivermectina. Mesmo parasitados, os animais permaneceram clinicamente saudáveis e sem anemia. O extrato etanólico do caule de Jatropha mollissima pode representar uma alternativa ao controle da verminose ovina, pois retarda a resistência parasitária.

Método FAMACHA para detectar anemia clínica causada por Haemonchus contortus em cordeiros lactentes e ovelhas em lactação

Resumo: O controle das endoparasitoses gastrintestinais em pequenos ruminantes tem sido tradicionalmente realizado por meio do uso indiscriminado dos anti-helmínticos, porém essa prática tem resultado em grande pressão de seleção de parasitas resistentes. Métodos seletivos (ex: FAMACHA/FMC e contagem de ovos nas fezes/OPG) e que apresentem boa sensibilidade para identificar os animais que necessitam receber o tratamento químico são importantes alternativas aos métodos tradicionais. O objetivo desse trabalho foi determinar a sensibilidade e a especificidade do método FMC, usado para detectar anemia causada por Haemonchus contortus em ovinos da raça Suffolk, em duas categorias de alta suscetibilidade; cordeiros lactentes e ovelhas durante a fase de lactação. A conjuntiva ocular de 42 cordeiros lactentes e 35 ovelhas em lactação foi avaliada usando o método FMC, em intervalos de 14 dias, durante cinco meses. O hematócrito (Ht) foi utilizado como padrão-ouro para avaliação clínica de anemia dos animais. Para o cálculo de sensibilidade e especificidade, diferentes critérios foram utilizados: animais classificados como 4 e 5 ou 3, 4 e 5 e anêmicos pelo Ht (teste positivo); animais classificados como 1, 2 e 3 ou 1 e 2 e não anêmicos pelo Ht (teste negativo). Três valores de corte para Ht (≤22%, ≤19% ou ≤15%) foram utilizados para confirmar a anemia. Entre os gêneros observados nas coproculturas, H. contortus (61,5%) e Ostertagiasp (21,3%) foram os mais prevalentes. Em ambas as categorias, a inclusão do FMC 3 como teste positivo, elevou a sensibilidade mas reduziu a especificidade do método. Quando o FMC 3 foi considerado anêmico, o percentual de falsos negativos foi próximo a zero, no entanto, houve aumento no número de tratamentos aplicados em animais não anêmicos (falso positivo). Durante as avaliações, a maior parte dos cordeiros (73%) e das ovelhas (53%) permaneceu nas categorias de FMC 1 e 2. Apenas 5% dos cordeiros e 8% das ovelhas foram classificados com os dois maiores graus de anemia (FMC 4 e 5). Os resultados indicam que o FMC pode ser utilizado para identificar os cordeiros lactentes e ovelhas em fase de lactação com sinais clínicos de anemia decorrentes da infecção por H. contortus. Para ambas as categorias, foi necessário incluir o FMC 3 como positivo para aumentar a sensibilidade do método; reduzindo o risco de morte de animais anêmicos não diagnosticados (falsos negativos).

Longitudinal evaluation of hepatic osteodystrophy in children and adolescents with chronic cholestatic liver disease

Bone mass loss is a major complication of chronic cholestatic liver disease (CCD). However, the long-term impact of CCD on bone mass acquisition is unknown. We longitudinally assessed bone mineral density (BMD) and factors involved in bone remodeling in 9 children and adolescents with CCD Child-Pugh A (5 boys/4 girls) and in 13 controls (6 boys/7 girls). The groups were evaluated twice, at baseline (T0) and after 3 years (T1), when osteocalcin, deoxypyridinoline, 25-hydroxyvitamin-D, parathyroid hormone, insulin-like growth factor-I (IGF-I), and BMD (L1-L4, proximal femur and total body) were determined. Serum levels of receptor activator for nuclear factor kB ligand (RANKL) and osteoprotegerin were measured only at T1. Lumbar spine BMD was reanalyzed twice: after adjustment for bone age and to compensate for the height factor. Volumetric density was also estimated mathematically in L2-L4. The BMD of L1-L4 was lower in the CCD group (Z-score at T0: control = -1.2 ± 0.8 vs CCD = -2.2 ± 1.4, P < 0.05; T1: control = -0.7 ± 0.8 vs CCD = -2.1 ± 1.1, P < 0.05). Osteocalcin and deoxypyridinoline were similar for the two groups. The CCD group presented lower IGF-I (Z-score at T1: control = 1.4 ± 2.8 vs CCD = -1.5 ± 1.0, P < 0.05) and RANKL (control = 0.465 ± 0.275 vs CCD = 0.195 ± 0.250 pM, P < 0.05) than control. Children with compensated CCD Child-Pugh A showed early impairment of bone acquisition, with the impact being more severe in an initial phase and then tapering in a slowly progressive way. Reduction in endocrine IGF-I has a crucial role in this process.

Effect of triiodothyronine on the maxilla and masseter muscles of the rat stomatognathic system

The maxilla and masseter muscles are components of the stomatognathic system involved in chewing, which is frequently affected by physical forces such as gravity, and by dental, orthodontic and orthopedic procedures. Thyroid hormones (TH) are known to regulate the expression of genes that control bone mass and the oxidative properties of muscles; however, little is known about the effects of TH on the stomatognathic system. This study investigated this issue by evaluating: i) osteoprotegerin (OPG) and osteopontine (OPN) mRNA expression in the maxilla and ii) myoglobin (Mb) mRNA and protein expression, as well as fiber composition of the masseter. Male Wistar rats (~250 g) were divided into thyroidectomized (Tx) and sham-operated (SO) groups (N = 24/group) treated with T3 or saline (0.9%) for 15 days. Thyroidectomy increased OPG (~40%) and OPN (~75%) mRNA expression, while T3 treatment reduced OPG (~40%) and OPN (~75%) in Tx, and both (~50%) in SO rats. Masseter Mb mRNA expression and fiber type composition remained unchanged, despite the induction of hypo- and hyperthyroidism. However, Mb content was decreased in Tx rats even after T3 treatment. Since OPG and OPN are key proteins involved in the osteoclastogenesis inhibition and bone mineralization, respectively, and that Mb functions as a muscle store of O2 allowing muscles to be more resistant to fatigue, the present data indicate that TH also interfere with maxilla remodeling and the oxidative properties of the masseter, influencing the function of the stomatognathic system, which may require attention during dental, orthodontic and orthopedic procedures in patients with thyroid diseases.

BMP-2 and titanium particles synergistically activate osteoclast formation

A previous study showed that BMP-2 (bone morphogenetic protein-2) and wear debris can separately support osteoclast formation induced by the receptor activator of NF-κB ligand (RANKL). However, the effect of BMP-2 on wear debris-induced osteoclast formation is unclear. In this study, we show that neither titanium particles nor BMP-2 can induce osteoclast formation in RAW 264.7 mouse leukemic monocyte macrophage cells but that BMP-2 synergizes with titanium particles to enhance osteoclast formation in the presence of RANKL, and that at a low concentration, BMP-2 has an optimal effect to stimulate the size and number of multinuclear osteoclasts, expression of osteoclast genes, and resorption area. Our data also clarify that the effects caused by the increase in BMP-2 on phosphorylated SMAD levels such as c-Fos expression increased throughout the early stages of osteoclastogenesis. BMP-2 and titanium particles stimulate the expression of p-JNK, p-P38, p-IkB, and P50 compared with the titanium group. These data suggested that BMP-2 may be a crucial factor in titanium particle-mediated osteoclast formation.

Elevated levels of plasma osteoprotegerin are associated with all-cause mortality risk and atherosclerosis in patients with stages 3 to 5 chronic kidney disease

Osteoprotegerin (OPG) regulates bone mass by inhibiting osteoclast differentiation and activation, and plays a role in vascular calcification. We evaluated the relationship between osteoprotegerin levels and inflammatory markers, atherosclerosis, and mortality in patients with stages 3-5 chronic kidney disease. A total of 145 subjects (median age 61 years, 61% men; 36 patients on hemodialysis, 55 patients on peritoneal dialysis, and 54 patients with stages 3-5 chronic kidney disease) were studied. Clinical characteristics, markers of mineral metabolism (including fibroblast growth factor-23 [FGF-23]) and inflammation (high-sensitivity C-reactive protein [hsCRP] and interleukin-6 [IL-6]), and the intima-media thickness (IMT) in the common carotid arteries were measured at baseline. Cardiac function was assessed by color tissue Doppler echocardiography. After 36 months follow-up, the survival rate by Kaplan-Meier analysis was significantly different according to OPG levels (χ2=14.33; P=0.002). Increased OPG levels were positively associated with IL-6 (r=0.38, P<0.001), FGF-23 (r=0.26, P<0.001) and hsCRP (r=0.0.24, P=0.003). In addition, OPG was positively associated with troponin I (r=0.54, P<0.001) and IMT (r=0.39, P<0.0001). Finally, in Cox analysis, only OPG (HR=1.07, 95%CI=1.02-1.13) and hsCRP (HR=1.02, 95%CI=1.01-1.04) were independently associated with increased risk of death. These results suggested that elevated levels of serum OPG might be associated with atherosclerosis and all-cause mortality in patients with chronic kidney disease.

Testing Normality : A GMM Approach

In this paper, we consider testing marginal normal distributional assumptions. More precisely, we propose tests based on moment conditions implied by normality. These moment conditions are known as the Stein (1972) equations. They coincide with the first class of moment conditions derived by Hansen and Scheinkman (1995) when the random variable of interest is a scalar diffusion. Among other examples, Stein equation implies that the mean of Hermite polynomials is zero. The GMM approach we adopted is well suited for two reasons. It allows us to study in detail the parameter uncertainty problem, i.e., when the tests depend on unknown parameters that have to be estimated. In particular, we characterize the moment conditions that are robust against parameter uncertainty and show that Hermite polynomials are special examples. This is the main contribution of the paper. The second reason for using GMM is that our tests are also valid for time series. In this case, we adopt a Heteroskedastic-Autocorrelation-Consistent approach to estimate the weighting matrix when the dependence of the data is unspecified. We also make a theoretical comparison of our tests with Jarque and Bera (1980) and OPG regression tests of Davidson and MacKinnon (1993). Finite sample properties of our tests are derived through a comprehensive Monte Carlo study. Finally, three applications to GARCH and realized volatility models are presented.

Les récepteurs activés par les protéases dans les tissus articulaires humains arthrosiques

L’arthrose (OA) est une maladie articulaire dégénérative à l’étiologie complexe et diverse. Les travaux de ces dernières années ont démontré que l’OA est une pathologie affectant tous les tissus de l’articulation incluant le cartilage, la membrane synoviale et l’os sous-chondral. L’OA se traduit par une déstructuration et une perte de fonctionnalité de l’articulation, et est principalement caractérisée par une perte de cartilage articulaire. L’inflammation de la membrane synoviale joue un rôle déterminant dans la progression de l’OA, toutefois elle serait secondaire à la dégradation du cartilage. De plus, l’os sous-chondral est également le siège de nombreuses transformations lors de l’OA. Il est fortement suggéré que ces changements ne correspondent pas seulement à une conséquence, mais pourraient être une cause du développement de l’OA impliquant une communication entre ce tissu et le cartilage. Il est maintenant bien établi que les voies inflammatoires et cataboliques jouent un rôle crucial dans l’OA. C’est pourquoi, nous avons étudié l’implication d’une nouvelle famille de récepteurs membranaires, les PARs, et plus particulièrement le PAR-2 dans les voies physiopathologiques de l’OA. Notre hypothèse est que l’activation de PAR-2 au cours de l’OA est un phénomène majeur du développement/progression de la maladie faisant du récepteur PAR-2 un candidat privilégié pour le développement de nouvelles approches thérapeutiques ciblant non seulement le cartilage mais aussi l’os sous-chondral. Pour cette étude, nous avons travaillé in vitro avec des chondrocytes (Cr) et des ostéoblastes (Ob) OA respectivement du cartilage et de l’os sous-chondral du condyle fémoral humain. Nos résultats ont démontré que PAR-2 était plus exprimé dans les Cr et les Ob OA que dans les cellules normales. Par ailleurs, PAR-2 est régulé positivement par certains facteurs retrouvés au cours de l’OA comme l’IL-1β, le TNF-α et le TGF-β dans les Cr OA, et par l’IL-1β, le TNF-α et la PGE2 dans les Ob OA. De plus, les principaux facteurs cataboliques et inflammatoires, soit la MMP-1, la MMP-13 et la COX-2 sont produits en quantité plus élevée suite à l’activation du récepteur dans le cartilage OA. De même, l’activation de PAR-2 dans les Ob OA conduit à une production accrue de facteurs pro-résorptifs tels que RANKL, l’IL-6, la MMP-1 et la MMP-9, et à l’augmentation de l’activité pro-résorptive de ces cellules. En outre, dans les deux types tissulaires étudiés, l’activation de PAR-2 augmente l’activité de certaines protéines de la famille des MAPKinases comme Erk1/2, p38 et JNK. Finalement, nous avons conclu notre étude en employant un modèle in vivo d’OA induite chez la souris sauvage et déficiente pour le gène PAR-2. Nos résultats ont démontré que l’absence d’expression et de production de PAR-2 influençait le processus inflammatoire et les changements structuraux affectant à la fois le cartilage et l’os sous-chondral, conduisant à un ralentissement du développement de l’OA. Nos travaux de recherche ont donc permis de montrer que le récepteur PAR-2 est un élément majeur du processus OA en agissant sur les voies cataboliques et inflammatoires du cartilage, et sur le remodelage tissulaire de l’os sous-chondral. Mots-clés : Arthrose, chondrocyte, cartilage, ostéoblaste, os sous-chondral, PAR-2, MMPs, COX, ILs, RANKL, résorption osseuse, MAPKinase, catabolisme, inflammation

Use of pelleted sericea lespedeza (Lespedeza cuneata) for natural control of coccidia and gastrointestinal nematodes in weaned goats

Infection with Eimeria spp. (coccidia) can be devastating in goats, particularly for young, recently-weaned kids, resulting in diarrhea, dehydration, and even death. Feeding dried sericea lespedeza [SL; Lespedeza cuneata (Dum.-Cours.) G. Don.] to young goats has been reported to reduce the effects of internal parasites, including gastrointestinal nematodes (GIN) but there have been no reports of the effects of feeding this forage on Eimeria spp. in goats. Two confinement feeding experiments were completed on recently-weaned intact bucks (24 Kiko-cross, Exp. 1; 20 Spanish, Exp. 2) to determine effects of SL pellets on an established infection of GIN and coccidia. The bucks were assigned to 1 of 2 (Exp. 1) or 3 (Exp. 2) treatment groups based upon the number of Eimeria spp. oocysts per gram (OPG) of feces. In Exp. 1, the kids were fed 1 of 2 pelleted rations ad libitum; 90% SL leaf meal + 10% of a liquid molasses/lignin binder mix and a commercial pellet with 12% crude protein (CP) and 24% acid detergent fiber (n = 12/treatment group, 2 animals/pen). For Exp. 2, treatment groups were fed 1) 90% SL leaf meal pellets from leaves stored 3 years (n = 7), 2) 90% SL pellets from leaf meal stored less than 6 months, (n = 7), and the commercial pellets (n = 6) ad libitum. For both trials, fecal and blood samples were taken from individual animals every 7 days for 28 days to determine OPG and GIN eggs per gram (EPG) and packed cell volume (PCV), respectively. In Exp. 2, feces were scored for consistency (1 = solid pellets, 5 = slurry) as an indicator of coccidiosis. In Exp. 1, EPG (P < 0.001) and OPG (P < 0.01) were reduced by 78.7 and 96.9%, respectively, 7 days after initiation of feeding in goats on the SL pellet diet compared with animals fed the control pellets. The OPG and EPG remained lower in treatment than control animals until the end of the trial. In Exp. 2, goats fed new and old SL leaf meal pellets had 66.2 and 79.2% lower (P < 0.05) EPG and 92.2 and 91.2% lower (P < 0.05) OPG, respectively, than control animals within 7 days, and these differences were maintained or increased throughout the trial. After 4 weeks of pellet feeding in Exp. 2, fecal scores were lower (P < 0.01) in both SL-fed groups compared with control animals, indicating fewer signs of coccidiosis. There was no effect of diet on PCV values throughout either experiment. Dried, pelleted SL has excellent potential as a natural anti-coccidial feed for weaned goats.

Antimicrobial Photodynamic Therapy in the Non-Surgical Treatment of Aggressive Periodontitis: Cytokine Profile in Gingival Crevicular Fluid, Preliminary Results

Background: Aggressive periodontitis is a specific form of periodontal disease that is characterized by rapid attachment loss and bone destruction. Cytokine profiles are of considerable value when studying disease course during treatment. The aim of this trial was to investigate cytokine levels in the gingival crevicular fluid (GCF) of patients with aggressive periodontitis, after treatment with photodynamic therapy (PDT) or scaling and root planing (SRP), in a split-mouth design on -7, 0, +1, +7, +30, and +90 days. Methods: Ten patients were randomly treated with PDT using a laser source associated with a photosensitizer or SRP with hand instruments. GCF samples were collected, and the concentrations of tumor necrosis factor-alpha (TNF-alpha) and receptor activator of nuclear factor-kappa B ligand (RANKL) were determined by enzyme-linked immunosorbent assays. The data were analyzed using generalized estimating equations to test the associations among treatments, evaluated parameters, and experimental times (alpha = 0.05). Results: Non-surgical periodontal treatment with PDT or SRP led to statistically significant reductions in TNF-alpha level 30 days following treatment. There were similar levels of TNF-alpha and RANKL at the different time points in both groups, with no statistically significant differences. Conclusion: SRP and PDT had similar effects on crevicular TNF-alpha and RANKL levels in patients with aggressive periodontitis. J Periodontol 2009;80:98-105.

Salivary Interleukin-6, Matrix Metalloproteinase-8, and Osteoprotegerin in Patients With Periodontitis and Diabetes

Background: Diabetes and periodontitis produce a protein discharge that can be reflected in saliva. This study evaluates the salivary concentrations of interleukin (IL)-6, matrix metalloproteinase (MMP)-8, and osteoprotegerin (OPG) in patients with periodontitis with type 2 diabetes. Methods: Whole saliva samples were obtained from 90 subjects who were divided into four groups: healthy (control; n = 22), untreated periodontitis (UPD; n = 24), diabetes mellitus (DM; n = 20), and UPD + DM (n = 24) groups. Clinical and metabolic data were recorded. Salivary IL-6, MMP-8, and OPG concentrations were determined by a standard enzyme-linked immunosorbent assay. Results: The UPD and UPD + DM groups exhibited higher salivary IL-6 than the control and DM groups (P <0.01). The salivary MMP-8 concentrations in all diseased groups (UPD, DM, and UPD + DM) were higher than in the control group (P <0.01). The salivary OPG concentrations in the DM group were higher than in the UPD and control groups (P<0.05). In the UPD + DM group, salivary IL-6 was correlated with glycated hemoglobin (HbA1c) levels (r = 0.60; P<0.05). The regression analysis indicated that the number of remaining teeth, clinical attachment level, and IL-6 might have influenced the HbA1c levels in patients with diabetes. Conclusions: Salivary 1L-6 concentrations were elevated in patients with periodontitis with or without diabetes. Salivary MMP-8 and OPG concentrations were elevated regardless of periodontal inflammation in patients with diabetes. Therefore, periodontitis and diabetes are conditions that may interfere with protein expression and should be considered when using saliva for diagnoses. J Periodontol 2010;81:384-391.

CCR5 Mediates Pro-osteoclastic and Osteoclastogenic Leukocyte Chemoattraction

Periodontal disease (PD) progression involves the selective leukocyte infiltration into periodontium, supposedly mediated by the chemokine/chemokine receptor system. In this study, we investigated the role of chemokine receptor CCR5 in the immunoregulation of experimental PD in C57BL/6 (WT) and CCR5KO mice. Aggregatibacter actinomycetem comitans infection triggered the chemoattraction of distinct CCR5+ leukocyte subpopulations (determined by flow cytometry): CCR5+F4/80+ leukocytes, which co-express CD14, CCR2, TNF-alpha, and IL-1 beta, indicative of activated macrophages; and CCR5+CD4+ cells, which co-express CXCR3, IFN-gamma, and RANKL, indicative of Th1 lymphocytes, therefore comprising pro-osteoclastic and osteoclastogenic cell subsets, respectively. CCR5KO mice presented a lower PD severity (lower inflammation and alveolar bone loss) when compared with the WT strain, since the migration of F4/80+, TNF-alpha+, CD4+, and RANKL+ cells specifically decreased due to the lack of CCR5. Also, ELISA analysis demonstrated that the production of TNF-alpha, IL-1 beta, IL-6, IFN-gamma, and RANKL in periodontal tissues was significantly decreased in the CCR5KO strain. The periodontal bacterial load and antimicrobial patterns were unaltered in CCR5KO mice. Our results demonstrate that the chemokine receptor is involved in the migration of distinct leukocyte subpopulations throughout experimental PD, being a potential target for therapeutic intervention in PD.

The importance of hormone receptor analysis in osteosarcoma cells growth submitted to treatment with estrogen in association with thyroid hormone

Bone tumor incidence in women peaks at age 50-60, coinciding with the menopause. That estrogen (E2) and triiodothyronine (T3) interact in bone metabolism has been well established. However, few data on the action of these hormones are available. Our purpose was to determine the role of E2 and T3 in the expression of bone activity markers, namely alkaline phosphatase (AP) and receptor activator of nuclear factor kappa B ligand (RANKL). Two osteosarcoma cell lines: MG-63 (which has both estrogen (ER) and thyroid hormone (TR) receptors) and SaOs-29 (ER receptors only) were treated with infraphysiological E2 associated with T3 at infraphysiological, physiological, and supraphysiological concentrations. Real-time RT-PCR was used for expression analysis. Our results show that, in MG-63 cells, infraphysiological E2 associated with supraphysiological T3 increases AP expression and decreases RANKL expression, while infraphysiological E2 associated with either physiological or supraphysiological T3 decreases both AP and RANKL expression. On the other hand, in SaOs-2 cells, the same hormone combinations had no significant effect on the markers` expression. Thus, the analysis of hormone receptors was shown to be crucial for the assessment of tumor potential growth in the face of hormonal changes. Special care should be provided to patients with T3 and E2 hormone receptors that may increase tumor growth. Copyright (C) 2007 John Wiley & Sons, Ltd.

Quantification of N-acetylcysteine in pharmaceuticals using cobalt phthalocyanine modified graphite electrodes

Flow injection analysis (FIA) with amperometric detection was employed for the quantification of N-acetylcysteine (NAC) in pharmaceutical formulations, utilizing an ordinary pyrolytic graphite (OPG) electrode modified with cobalt phthalocyanine (CoPc). Cyclic voltammetry was used in preliminary studies to establish the best conditions for NAC analysis. In FIA-amperometric experiments the OPG-CoPc electrode exhibited sharp and reproducible current peaks over a wide linear working range (5.0 x 10(-5)-1.0 x 10(-3) mol L(-1)) in 0.1 mol L(-1) NaOH solution. High sensitivity (130 mA mol(-1) cm(2)) and a low detection limit (9.0 x 10(-7) mol L(-1)) were achieved using the sensor. The repeatability (R.S.D.%) for 13 successive flow injections of a solution containing 5.0 x 10(-4) mol L(-1) NAC was 1.1%. The new procedure was applied in analyses of commercial pharmaceutical products and the results were in excellent agreement with those obtained using the official titrimetric method. The proposed amperometric method is highly suitable for quality control analyses of NAC in pharmaceuticals since it is rapid, precise and requires much less work than the recommended titrimetric method. (C) 2010 Elsevier B.V. All rights reserved.