Double Orthogonal Click Reactions for the Development of Antimicrobial Peptide Nanotubes.

A new class of amphipathic cyclic peptides, which assemble in bacteria membranes to form polymeric supramolecular nanotubes giving them antimicrobial properties, is described. The method is based on the use of two orthogonal clickable transformations to incorporate different hydrophobic or hydrophilic moieties in a simple, regioselective, and divergent manner. The resulting cationic amphipathic cyclic peptides described in this article exhibit strong antimicrobial properties with a broad therapeutic window. Our studies suggest that the active form is the nanotube resulted from the parallel stacking of the cyclic peptide precursors. Several techniques, CD, FTIR, fluorescence, and STEM, among others, confirm the nanotube formation.

Effect of Bivalent Vaccines against Vibrio anguillarum and Aeromonas salmonicida Subspecie achromogenes on Health and Survival of Turbot.

The efficacy of intraperitoneal injection of an oil-based bivalent autogenous vaccine and the commercial vaccine AlphaJect 3000 (Pharmaq AS) to prevent atypical furunculosis and vibriosis in turbot was analyzed. The effect of both vaccines on health parameters and survival of fish after challenge with V. anguillarum and A. salmonicida subsp. achromogenes was tested. The autogenous vaccine conferred high levels of protection and long-lasting immunity against both pathogens with a single dose. However, severe side effects were observed in turbot injected with this autovaccine and minor negative effects with the AlphaJect 3000 vaccine and the adjuvant Montanide or Eolane. All vaccinated fish showed remarkable antibody agglutination titers, higher than those of control fish, which were maintained 160 d after vaccination. In conclusion, the autogenous bivalent vaccine induces long-lasting protection against atypical furunculosis and vibriosis in turbot, after administration of a single dose, at the cost of high side effects in fish. Therefore, the development of new vaccines should focus on autovaccines and the use of liquid paraffin adjuvants that increase protection with reduced or no side effects.

Human Health Effects of Lactose Consumption as a Food and Drug Ingredient.

Lactose is a reducing sugar consisting of galactose and glucose, linked by a ß (1→4) glycosidic bond, considered as an antioxidant due to its α-hydroxycarbonyl group. Lactose is widely ingested through the milk and other unfermented dairy products and is considered to be one of the primary foods. On the other hand, lactose is also considered as one of the most widely used excipients for the development of pharmaceutical formulations. In this sense, lactose has been related to numerous drug-excipient or drug-food pharmacokinetic interactions. Intolerance, maldigestion and malabsorption of carbohydrates are common disorders in clinical practice, with lactose-intolerance being the most frequently diagnosed, afflicting 10% of the world's population. Four clinical subtypes of lactose intolerance may be distinguished, namely lactase deficiency in premature infants, congenital lactase deficiency, adult-type hypolactasia and secondary lactase intolerance. An overview of the main uses of lactose in human nutrition and in the pharmaceutical industry and the problems derived from this circumstance are described in this review.

Synthesis and antimicrobial activities of silver(I) 3-(substituted phenyl)sulfanylpropenoates.

We investigated the reactions of silver nitrate with 3-(substituted phenyl)-2-sulfanylpropenoic acids H(2)L [L=xspa, where spa=2-sulfanylpropenoato and xin{Clp=3-(2-chlorophenyl)-, -o-mp=3-(2-methoxyphenyl)-, -o-hp=3-(2-hydroxyphenyl)-, -p-hp=3-(4-hydroxyphenyl)-, diBr-o-hp=3-(3,5-dibromo-2-hydroxyphenyl)-}] in 1:1 and 2:1 molar ratios. The 1:1 reactions gave compounds of type [Ag(HL)], which reacted with NaOH to afford Na[Ag(L)].xH(2)O (x=1 or 2) and with diisopropylamine to afford [HQ][Ag(L)] (HQ=diisopropylammonium). The 2:1 reactions gave products of type [Ag(2)(L)]. All the new compounds were isolated and characterized by IR spectroscopy, and all except the 2:1 adducts (which were insoluble) were studied by (1)H and (13)C NMR spectroscopy; ESI-MS spectrometry was also used for [HQ][Ag(L)] and Na[Ag(L)].xH(2)O, and the crystal structures of H(2)Clpspa and [HQ][Ag(Clpspa)] were determined by X-ray diffractometry. The antimicrobial activities of the complexes against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albicans, Pseudomonas aeruginosa and carbapenem-resistant P. aeruginosa were evaluated and compared with those of Ag(I) complexes with other aryl sulfanylpropenoates or related ligands.

Triphenyltin derivatives of sulfanylcarboxylic esters.

The reaction of 3-(aryl)-2-sulfanylpropenoic acids [H2xspa; x: p=3-phenyl-, f=3-(2-furyl)-, t=3-(2-thienyl)-] with methanol or ethanol gave the corresponding methyl (Hxspme) or ethyl (Hxspee) esters. The reaction of these esters (HL) with triphenyltin(IV) hydroxide gave compounds of the type [SnPh3L], which were isolated and characterized as solids by elemental analysis, IR spectroscopy and mass spectrometry and in solution by multinuclear (1H, 13C and 119Sn) NMR spectroscopy. The structures of [SnPh3(pspme)], [SnPh3(fspme)] and [SnPh3(fspee)] were determined by X-ray diffractometry and the antimicrobial activity against E. coli, S. aureus, B. subtilis, P. aeruginosa, Resistant P. aeruginosa (a strain resistant to 'carbapenem'), and C. albicans was tested and the in vitro cytotoxic activity against the HeLa-229, A2780 and A2780cis cell lines was determined for all compounds.

Plitidepsin has a cytostatic effect in human undifferentiated (anaplastic) thyroid carcinoma.

Undifferentiated (anaplastic) thyroid carcinoma is a highly aggressive human cancer with very poor prognosis. Although there have been a few studies of candidate treatments, the fact that it is an infrequent tumor makes it very difficult to design clinical trials. A strong association has been observed between undifferentiated thyroid carcinoma and TP53 mutations in numerous molecular genetic and expression studies. Plitidepsin (Aplidin, PharmaMar, Madrid, Spain) is a novel anticancer compound obtained from a sea tunicate. This compound has been reported to induce apoptosis independently of TP53 status. We investigated the actions of plitidepsin in human thyroid cancer cells. In initial experiments using primary cultured cells from a differentiated (papillary) carcinoma, we found that 100 nmol/L plitidepsin induced apoptosis, whereas lower doses were cytostatic. Because our aim was to study the effects of plitidepsin at clinically relevant concentrations, subsequent experiments were done with a dosage regimen reflecting plasma concentrations observed in previously reported clinical trials: 100 nmol/L for 4 hours, followed by 10 nmol/L for 20 hours (4(100)/20(10) plitidepsin). This plitidepsin dosage regimen blocked the proliferation of a primary undifferentiated/anaplastic thyroid carcinoma culture obtained in our laboratory and of a commercial cell line (8305C) obtained from an undifferentiated thyroid carcinoma; however, it did not induce apoptosis. The proportion of cells in the G(1) phase of the cell cycle was greatly increased and the proportion in the S/G(2)-M phases greatly reduced, suggesting that plitidepsin blocks G(1)-to-S transition. Levels of the cyclin D1/cyclin-dependent kinase 4/p21 complex proteins were decreased and, in line with this, the levels of unphosphorylated Rb1 increased. The decrease in cell cycle proteins correlated with hypoacetylation of histone H3. Finally, we did experiments to assess how rapidly tumor cells return to their initial pretreatment proliferative behavior after 4(100)/20(10) plitidepsin treatment. Cells from undifferentiated tumors needed more than 3 days to recover logarithmic growth, and after 7 days, cell number was still significantly lower than in control cultures. 4(100)/20(10) plitidepsin inhibited the growth in soft agar. Together, our data show that plitidepsin is able to block in vitro cell cycle progression at concentrations similar to serum concentrations observed in vivo, and that this effect is persistent for several days after plitidepsin removal. Whether plitidepsin will prove to be clinically useful in the treatment of undifferentiated thyroid cancers remains to be established. However, our results raise the possibility that plitidepsin might be effective alone or in combination with radiotherapy and/or other drug treatments.

The Application of Flow Cytometry as a Rapid and Sensitive Screening Method to Detect Contamination of Vitreous Humor Samples and Avoid Miscalculation of the Postmortem Interval.

Research into maximizing the speed, precision, and reliability of estimating the postmortem interval (PMI) has been a recurring object of investigation and methodologies based on the vitreous humor (VH) have provided good results. However, contamination from causes not readily apparent, such as blood, can occur, and thus lead not only to an erroneous estimation of PMI, but also interfere with the correct identification of other substances in the VH. We have developed a flow cytometry method which quantifies blood contamination and is able to detect erythrocytes in 1:750,000 dilution of contaminated VH which affects the results of hypoxanthine. It is an improvement on the previous more complex mass spectrometry method, being faster, more sensitive, and readily available. As such, it could be proposed for the rapid screening of appropriate samples by detecting and eliminating blood contaminated samples from PMI estimation.

Measured Copper Toxicity to Cnesterodon decemmaculatus (Pisces: Poeciliidae) and Predicted by Biotic Ligand Model in Pilcomayo River Water: A Step for a Cross-Fish-Species Extrapolation.

In order to determine copper toxicity (LC50) to a local species (Cnesterodon decemmaculatus) in the South American Pilcomayo River water and evaluate a cross-fish-species extrapolation of Biotic Ligand Model, a 96 h acute copper toxicity test was performed. The dissolved copper concentrations tested were 0.05, 0.19, 0.39, 0.61, 0.73, 1.01, and 1.42 mg Cu L(-1). The 96 h Cu LC50 calculated was 0.655 mg L(-1) (0.823 - 0.488). 96-h Cu LC50 predicted by BLM for Pimephales promelas was 0.722 mg L(-1). Analysis of the inter-seasonal variation of the main water quality parameters indicates that a higher protective effect of calcium, magnesium, sodium, sulphate, and chloride is expected during the dry season. The very high load of total suspended solids in this river might be a key factor in determining copper distribution between solid and solution phases. A cross-fish-species extrapolation of copper BLM is valid within the water quality parameters and experimental conditions of this toxicity test.

Identification and functional characterization of two novel activating thyrotropin receptor mutants in toxic thyroid follicular adenomas.

BACKGROUND: Two previously unreported thyrotropin (TSH) receptor mutations, A623F and I635V, were identified in toxic follicular thyroid adenoma specimens from two patients with hyperthyroidism. Our aim was to characterize both novel mutants in terms of the following: cAMP basal constitutive activity, cAMP response to TSH, plasma membrane expression levels, and TSH binding properties. METHODS: We performed DNA extraction for TSHR gene sequencing. COS-7 cells were transiently transfected with wild-type and mutated TSH receptor constructs for determination of basal cAMP constitutive activity and dose-response accumulation of cAMP using recombinant human TSH. Flow cytometry analysis was performed to evaluate plasma membrane expression. Binding studies using bovine TSH as a ligand were performed to compare the affinities of wild-type and mutated TSH receptors for TSH. RESULTS: Both mutants, A623F and I635V, had higher cAMP basal constitutive activities than the wild-type TSH receptor. A623F but not I635V showed lower plasma membrane expression than the wild-type receptor. IC50, an indirect measurement of ligand-receptor affinity, was lower in A623F and higher in I635V than in the wild-type TSH receptor, although no statistically significant differences were observed. No differences were observed in EC50 and although the absolute values of maximal stimulation achieved with both mutants were higher than the wild type, the differences did not achieve statistical significance. CONCLUSIONS: A623F and I635V are two naturally occurring TSH receptor mutations that increase basal cAMP accumulation and consequently promote the development of toxic follicular thyroid adenoma. cAMP response to increasing TSH dose is retained by A623F and I635V mutated receptors and the maximal stimulation obtained is not different from that of the wild-type receptor. Substitution of alanine 623 by phenylalanine 623 at the third intracellular loop of the TSH receptor decreases its plasma membrane expression, indicating that alanine 623 is important in directing the TSH receptor to the cell surface or in down-regulating the constitutive receptor. By contrast, isoleucine 635, located in the sixth transmembrane domain, is important in regulating TSH receptor basal activity but does not modify its plasma membrane expression.

Acute silver toxicity to Cnesterodon decemmaculatus (Pisces: Poeciliidae) in a river with extreme water-quality characteristics / Toxicidad aguda de la plata sobre Cnesterodon decemmaculatus (Pisces: Poeciliidae) en un río con características extremas de calidad de agua

Abstract. A 96 h acute silver toxicity test was performed in order to determine silver toxicity (LC50) to a local fish species (Cnesterodon decemmaculatus) in a river with extreme water-quality characteristics (Pilcomayo River, South America) and evaluate a cross-fish-species extrapolation of the Biotic Ligand Model. The dissolved silver concentrations tested were 0.095, 0.148, 0.175 and 0.285 mg Ag L−1. The 96 h Ag LC50 calculated for C. decemmaculatus was 0.14 mg L−1 (0.18 - 0.10) and the value predicted by BLM for Pimephales promelas was 0.051 mg Ag L−1. Test water elevated hardness may have exerted some protective effect. High mean water pH may have exerted a major protective effect by reducing silver free ion form and causing silver precipitation. The mortality pattern observed in this toxicity test may lend some support to a relationship between gill silver accumulation and mortality. A cross-fish-species extrapolation of Ag BLM for P. promelas was not valid in Pilcomayo River water and experimental conditions of this toxicity test.

Con el objeto de determinar la toxicidad de la plata en un pez nativo (Cnesterodon decemmaculatus), se llevó a cabo un ensayo estático de toxicidad aguda a 96 horas en un agua natural con características de calidad de agua, extremas (río Pilcomayo, Sudamérica). Asimismo, se evaluó una posible extrapolación inter-especie del Modelo del Ligando Biótico en el agua experimental. La concentración inicial de plata en solución en los distintos tratamientos fue de 0,095; 0,148; 0,175 y 0,285 mg Ag L −1 . La CL50 a las 96 horas calculada para C. decemmaculatus fue de 0,14 (0.18 - 0.10) mg Ag L−1 y el valor predicho por el BLM para Pimephales promelas fue de 0,051 mg Ag L−1. La elevada dureza del agua experimental pudo haber tenido algún efecto protector frente a la toxicidad de la plata. El valor medio de pH del ensayo fue elevado y posiblemente tuvo un gran efecto protector por reducción de la forma iónica libre y precipitación del metal. El patrón de mortalidad observado en este ensayo de toxicidad apoyaría la relación causa-efecto entre acumulación de plata en las branquias y mortalidad. La extrapolación inter-especie del BLM para P. promelas no resultó válida en el agua del río Pilcomayo y en las condiciones experimentales de este ensayo.

Synthesis and antimicrobial activities of silver(I) sulfanylcarboxylates. Structural isomers with identically or unequally coordinated Ag centers in an Ag4S4 ring.

We have investigated the reactions of silver nitrate and 3-(aryl)-2-sulfanylpropenoic acids [H(2)xspa, x: p = 3-phenyl-, f = 3-(2-furyl)-, t = 3-(2-thienyl)-, py = 3-(2-pyridyl)-] and 2-cyclopentylidene-2-sulfanylacetic acid (H(2)L) in 1 : 1 and 2 : 1 molar ratios. The 1 : 1 molar ratio gave compounds of type [Ag(HL)]; reaction of these compounds with diisopropylamine and NaOH gave [HQ][Ag(L)] (HQ = diisopropylammonium) and Na[Ag(L)] x H(2)O, respectively. These compounds, as well as those of type [Ag(2)(L)] obtained with the 1 : 2 molar ratio, were isolated and characterized by IR and NMR ((1)H and (13)C) spectroscopy. (109)Ag NMR spectroscopy and ESI-MS spectrometry were also used in some cases. The crystal structures of [HQ][Ag(pspa)] (11), in which the presence of structural isomers was detected, and [HQ][Ag(cpa)] (15) were determined by X-ray diffractometry. The antimicrobial activity of the complexes against E. coli, S. aureus, B. subtilis, P. aeruginosa/Resistant P. aeruginosa, and C. albicans was tested.