No correlation between the expression of FXR and genes involved in multidrug resistance phenotype of primary liver tumors

Farnesoid X receptor (FXR) has been recently reported to enhance chemoresistance through bile acid-independent mechanisms. Thus, FXR transfection plus activation with GW4064 resulted in reduced sensitivity to cisplatin-induced toxicity. This is interesting because primary tumors of the liver, an organ where FXR is expressed, exhibit marked refractoriness to pharmacological treatment. Here we have determined whether FXR is upregulated in hepatocellular carcinoma (HCC), cholangiocarcinoma (CGC) and hepatoblastoma (HPB) and whether this is related with the expression of genes involved in mechanisms of chemoresistance. Using RT-QPCR and Taqman low density arrays we have analyzed biopsies from healthy livers or surgically removed tumors from naive patients and cell lines derived from HCC (SK-HEP-1, Alexander and Huh7), CGC (TFK1) and HPB (HepG2), before and after exposure to cisplatin at IC50 for 72 h. In liver tumors FXR expression was not enhanced but significantly decreased (healthy liver > HCC > HPB ≈ CGC). Except for CGC, this was not accompanied by changes in the proportions of FXR isoforms. Changes in 36 genes involved in drug uptake/efflux and metabolism, expression/function of molecular targets, and survival/apoptosis balance were found. Changes affecting SLC22A1, CYP2A1 and BIRC5 were shared by HCC, CGC and HPB. Similarity in gene expression profiles between cell lines and parent tumors was found. Pharmacological challenge with cisplatin induced changes that increased this resemblance. This was not dependent upon FXR expression. Thus, although FXR may play a role in inducing chemoresistance under certain circumstances, its upregulation does not seem to be involved in the multidrug resistance phenotype characteristic of HCC, CGC and HPB.

Disposition kinetics of albendazole and metabolites in laying hens

An increasing prevalence of roundworm parasites in poultry, particularly in litter-based housing systems, has been reported. However, few anthelmintic drugs are commercially available for use in avian production systems. The anthelmintic efficacy of albendazole (ABZ) in poultry has been demonstrated well. The goal of this work was to characterize the ABZ and metabolites plasma disposition kinetics after treatment with different administration routes in laying hens. Twenty-four laying hens Plymouth Rock Barrada were distributed into three groups and treated with ABZ as follows: intravenously at 10 mg/kg (ABZ i.v.); orally at the same dose (ABZ oral); and in medicated feed at 10 mg/kg·day for 7 days (ABZ feed). Blood samples were taken up to 48 h posttreatment (ABZ i.v. and ABZ oral) and up to 10 days poststart feed medication (ABZ feed). The collected plasma samples were analyzed using high-performance liquid chromatography. ABZ and its albendazole sulphoxide (ABZSO) and ABZSO2 metabolites were recovered in plasma after ABZ i.v. administration. ABZ parent compound showed an initial concentration of 16.4 ± 2.0 μg/mL, being rapidly metabolized into the ABZSO and ABZSO2 metabolites. The ABZSO maximum concentration (Cmax ) (3.10 ± 0.78 μg/mL) was higher than that of ABZSO2 Cmax (0.34 ± 0.05 μg/mL). The area under the concentration vs time curve (AUC) for ABZSO (21.9 ± 3.6 μg·h/mL) was higher than that observed for ABZSO2 and ABZ (7.80 ± 1.02 and 12.0 ± 1.6 μg·h/mL, respectively). The ABZ body clearance (Cl) was 0.88 ± 0.11 L·h/kg with an elimination half-life (T1/2el ) of 3.47 ± 0.73 h. The T1/2el for ABZSO and ABZSO2 were 6.36 ± 1.50 and 5.40 ± 1.90 h, respectively. After ABZ oral administration, low ABZ plasma concentrations were measured between 0.5 and 3 h posttreatment. ABZ was rapidly metabolized to ABZSO (Cmax , 1.71 ± 0.62 μg/mL) and ABZSO2 (Cmax , 0.43 ± 0.04 μg/mL). The metabolite systemic exposure (AUC) values were 18.6 ± 2.0 and 10.6 ± 0.9 μg·h/mL for ABZSO and ABZSO2 , respectively. The half-life values after ABZ oral were similar (5.91 ± 0.60 and 5.57 ± 1.19 h for ABZSO and ABZSO2 , respectively) to those obtained after ABZ i.v. administration. ABZ was not recovered from the bloodstream after ABZ feed administration. AUC values of ABZSO and ABZSO2 were 61.9 and 92.4 μg·h/mL, respectively. The work reported here provides useful information on the pharmacokinetic behavior of ABZ after both i.v. and oral administrations in hens, which is a useful first step to evaluate its potential as an anthelmintic tool for use in poultry.

In vivo measurements of electrical conductivity of porcine organs at low frequency: new method of measurement

Calculations of the induced currents created in the human body by external electromagnetic fields would be more accurate provided that more realistic experimental values of the electrical properties of the body were available. The purpose of this work is to experimentally obtain values for the conductivity of living organs in conditions close to the real situation. Two-electrode in vivo measurements of the bioimpedance of some porcine organs have been performed. From these measurements and taking into account geometrical considerations, the electrical conductivity for the kidney, liver, heart, and spinal cord has been obtained and were found to be higher than the values reported in the literature. Furthermore, a new experimental procedure is proposed where the conductivity is determined from the values of the electrical potential and currents that are induced by an external electromagnetic field created by a coil placed close to the organ under study.

Expression of α-defensin 1-3 in T cells from severe cutaneous drug-induced hypersensitivity reactions

BACKGROUND

Cytotoxic T cells seem to be the main effector cells in Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). However, recent data support a role of the innate immune system in the etiopathology of drug-induced cutaneous reactions. In this study, we analyzed the expression of α-defensins 1-3 in mononuclear cells from patients with SJS/TEN, drug-induced maculopapular exanthema (MPE), and healthy donors.

METHODS

DEFA1A3 gene expression was analyzed by quantitative and end-point RT-PCR. Intracellular flow cytometry, immunofluorescence and immunohistochemistry were carried out to verify α-defensin 1-3 protein expression in mononuclear cells from peripheral blood and skin infiltrates. α-Defensin 1-3 concentration was evaluated in plasma and blister fluid samples by ELISA.

RESULTS

We herein describe DEFA1A3 gene expression in peripheral blood mononuclear cells (PBMCs) from patients with drug-induced cutaneous diseases. Gene expression analysis unveiled transcription in CD4 and CD8 peripheral blood T cells. Protein expression was confirmed by intracellular flow cytometry in mononuclear cells from the patients, including monocytes, NK cells, and T cells from peripheral blood and blister fluid. Further analysis of protein content by flow cytometry revealed higher protein levels in CD56(+) CD3(+) lymphocytes from patients with SJS/TEN when compared to MPE and healthy donors. Immunohistological analysis was used to confirm expression in dermal infiltrates. α-Defensin levels were estimated by ELISA to be 3- to 175-fold higher in blister fluid when compared to simultaneously drawn plasma samples.

CONCLUSION

Upregulation of innate immune molecules such as α-defensins 1-3 in T cells from patients with SJS/TEN may be involved in the etiopathology of these life-threatening diseases induced by medications.

The role of bovine causal genes underlying dairy traits in Spanish Churra sheep

In dairy cattle, quantitative trait nucleotides (QTNs) underlying quantitative trait loci (QTL) for milk production traits have been identified in bovine DGAT1, GHR and ABCG2 genes. The SPP1 gene has also been proposed to be a regulator of lactation. In sheep, QTL underlying milk production traits have been reported only recently, and no proven QTN has been identified. Taking into account the close phylogenetic relationship between sheep and cattle, this study examined the possible effects of the aforementioned genes on sheep milk production traits. We first studied the genetic variability of the DGAT1, GHR, ABCG2 and SPP1 genes in 15 rams of the Spanish Churra dairy sheep breed. Second, we performed an association analysis between SNPs identified in these genes and three milk production traits recorded in a commercial population of Churra sheep. This analysis revealed only three significant associations at the nominal level (P-value <0.05) involving allelic variants of the ABCG2 gene, whereas no significant association was found for the DGAT1, GHR and SPP1 genes. When the Bonferroni correction was applied to take into account the multiple tests performed, none of the associations identified at the nominal level remained significant. Nevertheless, taking into account the high level of false-negative findings that can arise when applying the stringent Bonferroni correction, we think that our results provide a valuable primary assessment of strong candidate genes for milk traits in sheep.

Interference with P-glycoprotein improves ivermectin activity against adult resistant nematodes in sheep

The in vivo co-administration of ivermectin (IVM) with P-glycoprotein (P-gp) modulator agents has been shown to enhance its systemic availability. However, there is no sufficient evidence on the impact that this type of drug-drug interaction may have on the in vivo efficacy against resistant nematodes in ruminant species. The current work reports on the effects of loperamide (LPM), a P-gp modulating agent, on both IVM kinetic behaviour and anthelmintic activity in infected lambs. Eighteen (18) lambs naturally infected with IVM-resistant gastrointestinal nematodes were allocated into three (3) experimental groups. Group A remained as untreated control. Animals in Groups B and C received IVM (200mug/kg, subcutaneously) either alone or co-administered with LPM (0.2 mg/kg, twice every 12h), respectively. Individual faecal samples were collected from experimental animals at days -1 and 14 post-treatment to perform the faecal eggs count reduction test (FECRT). Blood samples were collected between 0 and 14 days post-treatment and IVM plasma concentrations were determined by HPLC. Additionally, at day 14 post-treatment, lambs from all experimental groups were sacrificed and adult gastrointestinal nematode counts were performed. FECRT values increased from 78.6 (IVM alone) to 96% (IVM+LPM). Haemonchus contortus was highly resistant to IVM. The IVM alone treatment was completely ineffective (0% efficacy) against adult H. contortus. This efficacy value increased up to 72.5% in the presence of LPM. The efficacy against Trichostrongylus colubriformis increased from 77.9% (IVM alone) to 96.3% (IVM+LPM). The described favorable tendency towards improved anthelmintic efficacy was in agreement with the enhanced IVM plasma availability (P<0.05) and prolonged elimination half-life (P<0.05) induced by LPM in infected lambs. A LPM-induced P-gp modulation increases IVM systemic exposure in the host but also it may reduce P-gp efflux transport over-expressed in target resistant nematodes.

Lithocholic acid downregulates vitamin D effects in human osteoblasts

BACKGROUND

Osteoporosis is a common complication in chronic cholestasis. It has been proposed that retained substances such as bile acids may produce a damaging effect on bone cells. This study analyses the effects of lithocholic acid (LCA) on cell survival and vitamin D metabolism in human osteoblasts (hOB).

MATERIALS AND METHODS

Human osteoblasts cultures were performed with or without foetal bovine serum (FBS) or human albumin (HA) at different LCA concentrations and times with or without vitamin D.

RESULTS

Lithocholic acid at concentrations higher than 10(-5 )M decreased cell survival. This effect was partially prevented by the presence of FBS or HA. Vitamin D stimulated CYP24A, BGLAP and TNFSF11 expression in hOB and these effects were modified by nontoxic LCA concentrations. LCA significantly decreased vitamin D stimulation of CYP24A, BGLAP and TNFSF11 gene expression at 72%, 79% and 56% (respectively). LCA alone has an agonistic effect, as has vitamin D, thus partially increasing CYP24A and BGLAP expression, but with no changes on TNFRSF11B expression. Equivalent effects of the LCA were observed by performing gene reporter assays using MG-63 cells transfected with constructs containing CYP24A1 promoter regions.

CONCLUSIONS

Lithocholic acid decreases the stimulatory effect of vitamin D on CYP24A, BGLAP and TNFSF11 expression in hOB. This effect is produced through vitamin D response elements (VDREs), located in the promoter regions of these genes, suggesting that LCA acts as a mild analogous of vitamin D, interacting with the vitamin D receptor. These results may explain the potential deleterious effects of retained bile acids on hOB.

Therapeutic efficacy of unilateral subthalamotomy in Parkinson's disease: results in 89 patients followed for up to 36 months

BACKGROUND

Stereotactic thermocoagulative lesions of the subthalamic nucleus (STN) have been shown to induce significant motor improvement in patients with Parkinson's disease (PD).

PATIENTS AND METHODS

89 patients with PD were treated with unilateral subthalamotomy. 68 patients were available for evaluations after 12 months, 36 at 24 months and 25 at 36 months.

RESULTS

The Unified Parkinson's Disease Rating Scale (UPDRS) motor scores improved significantly contralaterally to the lesion in the "off" and "on" states throughout the follow-up, except for the "on" state at the last evaluation. Axial features and signs ipsilateral to the lesion progressed steadily throughout the study. Levodopa daily doses were significantly reduced by 45%, 36% and 28% at 12, 24 and 36 months post-surgery. 14 patients (15%) developed postoperative hemichorea-ballism which required pallidotomy in eight. These 14 patients had significantly higher dyskinesia scores (levodopa induced) preoperatively than the entire cohort.

CONCLUSION

Unilateral subthalamotomy was associated with significant and sustained motor benefit contralateral to the lesion. Further work is needed to ascertain what factors led to severe, persistent chorea-ballism in a subset of patients. Subthalamotomy may be considered an option in circumstances when deep brain stimulation is not viable.

Identification of differentially expressed genes in trabecular bone from the iliac crest of osteoarthritic patients

OBJECTIVE

Osteoarthritis (OA) is clinically characterized by degeneration of the joints and has been traditionally considered a primary disorder of articular cartilage, with secondary changes in the subchondral bone. The increased bone mass and generalized changes in bone quality observed in osteoarthritic patients suggest that OA may be a primary systemic bone disorder with secondary articular cartilage damage. The iliac crest is a skeletal site distant from the affected joint, with a minimal load-bearing function. To provide evidence that OA is a systemic disorder, we searched for differentially expressed genes in the iliac crest bone of patients suffering from hip OA.

MATERIAL AND METHODS

Gene expression levels between bone samples collected at surgery from the iliac crest of patients undergoing total hip arthroplasty for primary OA and younger donors, who were undergoing spinal arthrodesis, were investigated by means of oligonucleotide microarrays. To verify data detected by microarrays technology, Real Time Reverse Transcription-Polymerase Chain Reaction (RT-PCR) assays were performed with specimens from osteoarthritic patients and donors, as well as from elderly donors who were undergoing arthroplasty for subcapital femoral neck fracture.

RESULTS

The microarray analysis surveyed 8327 genes and identified 83 whose expression levels differed at least 1.5-fold in the OA group (P<0.005). Comparisons between Real Time RT-PCR data from OA and the two donor groups indicated differential expression of genes involved in bone cell functions in the group of OA patients. The genes identified, including CCL2, FOS, PRSS11, DVL2, AKT1, CA2, BMP6, OMD, MMP2, TGFBR3, FLT1, BMP1 and TNFRS11B, have known roles in osteoblast or osteoclast activities.

CONCLUSIONS

The data from this study identify a set of genes, closely related to bone cell functions, in which differential regulation in osteoarthritic bone distant from the diseased subchondral bone might underlie the etiopathogenesis of OA as a generalized bone disease.

Energy consumption as a predictor test of the durability of a biological tissue employed in cardiac bioprosthesis

The mechanical behavior of the young bull pericardium in a fatigue test has been studied. This material is a similar tissue to those used in valve leaflet construction for a cardiac bioprosthesis. The consumed energy on each test was evaluated and afterwards used as a predictor of the biomaterial strength. Two-hundred and nine samples were tested to cyclical fatigue. The cut-off point to determine the sample quality was whether or not they resisted at least 4500 cycles. Only 22 samples withstood over that point (10.52%). The samples were classified according to their fatigue behavior in excellent, undefined and unsuitable. By using as a reference the consumed energy in the first 25 cycles, we could distinguish correctly (between 93.2 and 96.1%) the unsuitable material and most of the excellent (between 78.1 and 95.2%). From the rejected material 77% was really detachable and from the accepted, only 50% was excellent, with an equal methodology. The receiver operating characteristics curve was employed to establish decision levels when selecting samples, being 0.85 the best area (theoretical maximum value of 1). It is concluded that the energy wasted is a good predictor of the strength of the tissue. More than 90% of the unsuitable material and 50% of the excellent material (5% of all the material) is detected with this method.

Pattern of ivermectin (sheep) and doramectin (cattle) residues in muscular tissue from various anatomical locations

This trial reports comparative drug residual concentrations in muscular tissue obtained from various anatomical locations after subcutaneous administration of ivermectin (IVM) to sheep and topical treatment with doramectin (DRM) to calves at recommended therapeutic dose rates. Seven muscle samples from different anatomical locations (rhomboideus, supraspinatus, semitendinosus, gluteus medius, longissimus dorsi thoracis, intercostales and diaphragma) were collected at several post-treatment sampling times. Samples were frozen at-20 degrees C until analyzed by HPLC. The highest IVM residual concentrations in muscular tissue from the different locations were found at 15 days post-treatment in sheep. Although the highest IVM mean concentrations were measured at 15 (16.8 +/- 5.17 ng g(-1)) and 20 (10.5 +/- 4.06 ng g(-1)) days post-administration in the intercostales muscles, at 30 days post-administration, the IVM concentration in this location was similar to that measured in the rhomboideus and diaphragma muscles. DRM residual concentrations were quantified in muscular tissue from all anatomical locations after topical administration to calves. Maximum residue level was observed at 10 days post-treatment in all anatomical sites. The diaphragma muscle showed the highest DRM residue levels at 2 (22.0 +/- 4.35 ng g(-1)), 5 (45.2 +/- 3.78 ng g(-1)) and 10 (57.9 +/- 9.57 ng g(-1)) days post-treatment in calves. These results demonstrated that the pattern of residue depletion from muscular tissue may differ according to its anatomical locations and/or physiological role. This should be considered in implementing residue control strategies in meat safety assurance for human consumption.

Idiopathic osteoporosis in premenopausal women. Clinical characteristics and bone remodelling abnormalities

OBJECTIVE

Osteoporosis is infrequent in young premenopausal women and is often associated with secondary disorders. However, idiopathic osteoporosis may be found in this setting and few data are known on this condition. Therefore, the aim of this study was to analyse the clinical characteristics and bone remodelling abnormalities in premenopausal women with idiopathic osteoporosis.

METHODS

28 premenopausal women with idiopathic osteoporosis (aged 38.3+/-7.6 years) were included. The patients had one or more fragility fractures and/or decreased bone mass (z-score <-2 in the lumbar spine or femur). In all patients, secondary causes of osteoporosis were excluded and previous skeletal fractures, family history and risk factors for osteoporosis were recorded. In addition, bone mineral density at the lumbar spine and hip, spinal x-rays, and laboratory tests including PTH, 25-hydroxyvitamin D, 1,25 (OH)<inf>2</inf> vitamin D and urinary calcium excretion were measured. Bone markers such as serum bone alkaline phosphatase (bone AP) and P1NP, and urinary hydroxyproline (HYP), NTx and CTx were measured and results were compared with those observed in a control group of 28 healthy premenopausal women.

RESULTS

46% of the patients had previous fragility fractures, 53% had family history of osteoporosis, 36% had associated hypercalciuria and 30% had a BMI <20 Kg/m². Patients with idiopathic osteoporosis had increased bone resorption markers (NTx and HYP) but normal bone formation markers when compared with healthy controls. No significant differences in the clinical and biochemical parameters were observed between patients with or without hypercalciuria.

CONCLUSION

Young women with idiopathic osteoporosis have an increased bone resorption without changes in bone formation when assessed by biochemical markers.

Serum levels of antibodies to Chlamydia pneumoniae and human HSP60 in giant cell arteritis patients

OBJECTIVE

To measure the serum levels of IgG anti-Chlamydia pneumoniae (C. pneumoniae) and human heat shock protein (hHSP) 60 antibodies in patients with active giant cell arteritis (GCA) and to determine whether such levels decrease with corticosteroid therapy and remission of symptoms.

METHODS

IgG anti-C. pneumoniae and anti-hHSP60 antibodies were quantified by commercial and in-house ELISA tests, respectively, in serum samples from 17 GCA patients, 39 polymyalgia rheumatica (PMR) patients and 23 age-matched healthy subjects.

RESULTS

Serum IgG anti-hHSP60, but not anti-C. pneumoniae, antibodies were significantly increased in GCA patients in comparison with PMR patients or healthy controls. After steroid therapy, both anti-hHSP60 and -C. pneumoniae antibodies decreased significantly in both groups of patients.

CONCLUSIONS

Although some infectious agents have been suggested to participate in GCA pathogenesis, our data do not suggest that C. pneumoniae might be one of them. The production of anti-hHSP60 antibodies is shared in GCA with other systemic diseases and may be triggered by unknown infectious agents and/or other inflammatory factors.

A male linkage map constructed for QTL mapping in Spanish Churra sheep

A male ovine linkage map has been constructed on the basis of 11 half-sib families of a commercial population of Spanish Churra sheep as part of a genome scan for quantitative trait loci mapping. A total of 1421 daughters and their sires were genotyped for 182 microsatellite markers evenly distributed along the ovine autosomes. A total of 259,192 genotypes were obtained, generating an average of 669 informative meioses per marker. An autosomal genome length of 3262 cM was estimated for the Churra population with a mean marker interval of 17.86 cM. Our map represents an approximate 90% coverage of the autosomal ovine genome and constitutes a useful tool for the genetic dissection of complex traits in this breed. General agreement was found between the Churra map and other published maps for sheep, despite certain length discrepancies.

Short communication: detection of quantitative trait loci influencing somatic cell score in Spanish Churra sheep

Eleven half-sib ovine families, including 1,421 Spanish Churra ewes, were analyzed for 181 microsatellite markers spanning the entire autosomic ovine genome. Using a multimarker regression method, a daughter experimental design was used to identify putative quantitative trait loci (QTL) affecting the somatic cell score (SCS). Chromosome-wise significance thresholds were set empirically by permuting the phenotypic data. Marker order and genetic distances of the autosomic linkage map built for this commercial population were in accordance with the published ovine linkage map. An across-family association analysis revealed a region on chromosome 20 suggestive of evidence for a QTL. Segregation of the QTL into 2 families was inferred from the within-family analysis, and differences in the position of the suggested QTL were found between the 2 half-sib groups. This could be the result of incomplete information associated with the markers for the significant families. The location of the major histocompatibility complex in proximity to the across-family effect suggests this region may harbor a segregating QTL for the SCS in the Churra population. Studies in dairy cattle examining the SCS have reported linkage associations on corresponding bovine orthologous regions, supporting the validity of our findings.

Aetiology and clinical characteristics of male osteoporosis. Have they changed in the last few years?

OBJECTIVE

The aim of this study was to analyse the clinical characteristics and etiological factors related to male osteoporosis in patients attending an out-patient rheumatology department during an 11-year period (1995-2006), as well as to compare them with the observed characteristics in a previous study performed 12 years ago.

METHODS

232 males aged 21-88 (mean 56.1+/-14) with osteoporosis were included in the study. Previous skeletal fractures and family history of osteoporosis were recorded. Bone mass assessment, automated biochemical profile and hormonal measurements (including PTH, 25-OH vitamin D, cortisol, thyroid and sexual hormones) were performed on most patients as well as 24 h urinary calcium, and bone markers. In patients with idiopathic osteoporosis 1-25-OH2 vitamin D was also determined. In addition, x-rays of the spine were obtained for all patients.

RESULTS

67% of the patients had previous skeletal fractures and 51% had vertebral fractures. 57% of the patients had idiopathic and 43% had secondary osteoporosis whereas in the previous series only 22% of the patients had idiopathic disease. The most frequent causes of secondary osteoporosis were corticosteroid therapy, hypogonodism and alcoholism. 38% of the patients with idiopathic osteoporosis had associated hypercalciuria. Patients with secondary osteoporosis were older, shorter, had lower femoral neck T-score and lower serum values of 25-OH vitamin D and testosterone, as well as higher gonadotrophin and PTH values than the patients with idiopathic osteoporosis, whereas patients with idiopathic osteoporosis had higher urinary calcium and more frequent family history of osteoporosis. Hypercalciuric patients were younger, had lower lumbar BMD, higher urinary calcium and greater incidence of lithiasis than normocalciuric patients with idiopathic osteoporosis. Back pain, frequently associated with vertebral fractures, was the most common cause of referral in all groups of patients.

CONCLUSION

Idiopathic osteoporosis is the most frequent cause of male osteoporosis in this study. In these patients, family history of osteoporosis and associated hypercalciuria are frequent. The most frequent causes of secondary osteoporosis in males include corticosteroid therapy, hypogonadism and alcoholism. Although clinical characteristics of male osteoporosis are similar to that previously reported, in this study the percentage of patients with idiopathic osteoporosis was higher than previously observed.

[Relationship between methylenetetrahydrofolate reductase polymorphism and homocysteine levels in women with recurrent pregnancy loss: a nutrigenetic perspective]

The objective of this study was to evaluate if there is any difference in the proportion of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms and the homocysteine levels in a group of women with recurrent pregnancy loss (RPL) and a control group. Ninety-three patients with diagnosis of three or more gestational losses and 206 healthy women with two or more children, were included. After acceptance of informed consent, samples of peripheral blood were taken to determine the genetic polymorphisms of MTHFR C677T and the plasmatic levels of homocysteine. The carriers of the homozygous mutation TT of MTHFR 677T polymorphism were 12.9% (12 of 93) in the group of patients and 14.6% (30 of 206) in the control group; 46.2% (43 of 93) and 40% (83 of 206) in the group of patients and controls respectively, were heterozygous CT for MTHFR gene. The levels of homocysteine were 7.2 micromol/ml in the group of patients and 7.7 mmol/l in controls. There was no relationship between MTHFR gene polymorphisms and the increase of homocysteine levels, nor of these one with RPL. From the nutrigenetics perspective we suggest that studies related to MTHFR polymorphisms and the risk of disease include the levels of folate and B6 and B12 vitamins participating in the tetrahydrofolate cycle for trying to establish a direct relation among the genotype, the level of metabolite and the clinical manifestations. In this regard, we recommend the administration of folic acid in women in search of pregnancy due to the high frequency of heterozygous and homozygous for MTHFR C677T mutation in our population.

Identification of a new leucine haplotype (ALQ) at codon 154 in the ovine prion protein gene in Spanish sheep

Genetic susceptibility to scrapie is closely linked to variations at codons 136, 154, and 171 of the prion protein (PRNP) gene. This association between the PRNP genotype and susceptibility to scrapie is the basis of breeding programs for scrapie resistance in different countries. In this paper, we describe the method used with 2 Spanish dairy sheep breeds (Churra and Castellana) to ascertain the initial status of protection against scrapie as a first step toward adapting their breeding schemes to include resistance as a complementary selection criterion. The procedure for genotype identification is based on multiplex minisequencing methodology and has been shown to be accurate, easy to interpret, and to have a medium throughput. The frequency of the ARQ allele was similar in the 2 populations at nearly 70%. The ARR allele, associated with resistance in the homozygous state, reaches around 23% in Churras and nearly 20% in Castellanas. The high-risk VRQ allele appeared at a relatively low frequency in both breeds. No other haplotypes were found in these 2 breeds. Furthermore, in this screening we found a new allele carrying leucine at codon 154. This new genetic variant might play a role in susceptibility to scrapie because codon 154 belongs to a region considered to have an important role in conformational conversion of the cellular to the pathogenic protein.

Influence of the suture in the propagation of tears in calf pericardium employed in the construction of cardiac bioprostheses

The tearing of the fibers of biomaterials employed in implants or bioprostheses leads to early the failure of these devices. The purpose of this study was to determine the force necessary to propagate a tear in a biological tissue, calf pericardium, when sutured. We analyzed the outcome of 230 trials. There was a loss of resistance to tearing in samples sutured edge-to-edge as compared to unsutured control samples. This loss was not observed when the suture was preceded by an intact or protective zone. The values corresponding to the tearing force for an overlapping suture, especially when sewn with Gore-Tex(R), were higher than those obtained in controls. This study confirms the deleterious effect of the edge-to-edge suture, which can be minimized by protecting the suture, and the excellent behavior of the overlapping suture.

NEXAFS study of multi-walled carbon nanotubes functionalization with sulfonated poly(ether ether ketone) chains

Functionalization of multi-walled carbon nanotubes (MWNTs) surface by sulfonated poly (ether ether ketone) SPEEK chains using a direct attachment reaction was investigated. A two step method was performed. MWNTs were oxidized by a nitric acid treatment to generate carboxyl groups on their surface. The grafting reaction of sulfonated groups of SPEEK with carboxyl groups present on the surface of oxidized MWNTs readily proceeds by using hexane diamine as an interlinking molecule. Transmission electron microscopy (TEM) shows that tubes are wrapped by polymer chains. Near edge X-ray absorption fine structure spectroscopy (NEXAFS) at the C K-edge, O K-edge, and N K-edge and X-ray photoelectron spectroscopy (XPS) were used to give evidence of covalent functionalization of MWNTs by SPEEK macromolecules.

Spectroscopic study of nitrogen doping of multi-walled carbon nanotubes

Combined spatially resolved electron-energy loss spectroscopy (EELS) and high resolution near-edge X-ray absorption fine structure (NEXAFS) spectroscopy have been used to investigate the nitrogen doping of multi-walled carbon nanotubes (N-MWNT). EELS indicates that most of the tubes are nitrogen-doped. NEXAFS spectroscopy reveals pyridine-like and nitrile N structures. High resolution NEXAFS experiments show that the main nitrogen concentration originates from a high amount of molecular N2 encapsulated into only a small quantity of tubes.

Resistance-induced changes in triclabendazole transport in Fasciola hepatica: ivermectin reversal effect

Triclabendazole (TCBZ) and albendazole (ABZ) are flukicidal benzimidazole compounds extensively used in veterinary medicine. Although TCBZ has excellent activity against mature and immature stages of the liver fluke, Fasciola hepatica, ABZ action is restricted to flukes older than 12 wk. The intensive use of TCBZ has resulted in the development of resistance. To gain insight into the mechanisms of resistance to TCBZ, the ex vivo diffusion of TCBZ, TCBZ sulfoxide (TCBZSO, the active metabolite of TCBZ), and ABZ into TCBZ-susceptible and -resistant adult flukes was compared. TCBZ-susceptible (Cullompton) and -resistant (Sligo) flukes were incubated in Krebs-Ringer Tris buffer with either TCBZ, TCBZSO, or ABZ (5 nmol/ ml) for 90 min. Drug/metabolite concentrations were quantified by high-performance liquid chromatography. All the assayed molecules penetrated through the tegument of both susceptible and resistant flukes. However, significantly lower concentrations of TCBZ and TCBZSO were recovered within the TCBZ-resistant flukes. In contrast, ABZ entrance into the susceptible and resistant flukes was equivalent. The influx/efflux balance for TCBZ, TCBZSO, and ABZ in susceptible and resistant flukes in the presence or absence of a substrate (ivermectin) of the drug transporter P-glycoprotein was assessed. The ivermectin-induced modulation of P-glycoprotein activity decreased TCBZ efflux from the resistant flukes. Higher concentrations of TCBZ and TCBZSO were recovered from the resistant liver flukes in the presence of ivermectin. Thus, an altered influx/efflux mechanism may account for the development of resistance to TCBZ in F. hepatica.

Treatment with tiludronate has a similar effect to risedronate on Paget's disease activity assessed by bone markers and bone scintigraphy

OBJECTIVE

To compare the effects of tiludronate and risedronate on Paget's disease activity assessed by biochemical markers of bone turnover and quantitative bone scintigraphy.

METHODS

An open-labeled non-randomized study was performed in 49 patients with Paget's disease who had completed treatment with tiludronate (400 mg/d) for 3 months (28 patients) or risedronate (30 mg/d) for 2 months (21 patients). Biochemical markers of bone turnover, including serum total alkaline phosphatase (TAP), bone alkaline phosphatase (BAP), procollagen type I N propeptide (PINP) and urinary N-terminal cross-linking telopeptide of type I collagen (NTX) were measured at baseline and at 6 and 12 months after the end of treatment. Quantitative bone scintigraphy at baseline and 6 months after the end of treatment was performed in all patients obtaining a scintigraphic activity index (SAI).

RESULTS

At baseline there were no significant differences in disease activity between both groups of patients, since markers of bone turnover as well as SAI were similar in both groups. The effects of tiludronate and risedronate in reducing the biochemical markers of bone turnover were comparable at 6 months (tiludronate vs risedronate: TAP -52% vs -43%; BAP -69% vs -56%; PINP -68% vs -63%; NTX -62% vs -59%) and at 12 months after the end of treatment (tiludronate vs risedronate: TAP -47% vs -36%; BAP -57% vs -46%; PINP -57% vs -52%; NTX -51% vs -52%). The effects of tiludronate and risedronate on SAI were also similar 6 months after the discontinuation of treatment. In addition, the percentage of patients who showed normalized serum TAP levels at 6 months after treatment were similar with both agents (74% with tiludronate and 70% with risedronate).

CONCLUSION

Tiludronate and risedronate given at the currently recommended dosages induce similar responses in Paget's disease activity.

Understanding triclabendazole resistance

Triclabendazole (TCBZ) has been the drug of choice to treat liver fluke infections in livestock for >20 years, due to its high activity against both adult and juvenile flukes. More recently, it has been used successfully to treat human cases of fascioliasis. Resistance to TCBZ first appeared in the field in Australia in the mid-1990s. Since then, resistance has been reported from a number of countries throughout Europe: Ireland, Scotland, Wales, Spain and The Netherlands. The heavy reliance on a single drug puts treatment strategies for fascioliasis at risk. Should resistance develop further, the prospect is an alarming one. This review will present an overview of progress in understanding the mechanism of resistance to TCBZ, examining possible changes in the target molecule, in drug influx/efflux mechanisms and in the metabolism of TCBZ by the fluke. The review will also consider ways to deal with resistance, covering drug-oriented options such as: the use of alternative drugs, drug combinations and the search for new compounds.

[Diagnosis of caseous lymphadenitis in sheep from Patagonia]

Caseous lymphadenitis (CLA) is a chronic bacterial, infectious and contagious disease caused by Corynebacterium pseudotuberculosis. It affects sheep and results in abscesses of the lymph nodes in subcutaneous tissue, as well as in internal organs such as lungs, liver and kidneys. Differential diagnosis of the disease is based on the isolation and biochemical identification of the etiological agent. The purpose of this study was to characterize the bacteria isolated from typical CLA lesions in sheep from Patagonia, Argentina, at metabolic and genetic levels. Macroscopic observations show a fibrous membrane containing caseous necrotic tissue. Histopathological analysis shows an eosinophilic necrotic area surrounded by epitheloid cells and polymorphonuclear infiltration. Other analyses performed such as microscopic observations, in vitro culture, biochemical tests and 16s rDNA sequencing confirmed diagnosis of caseous lymphadenitis due to C. pseudotuberculosis.