Antibacterial Activity Assessment of Chitosan/Alginate Lavender Essential Oil Membranes for Biomedical Applications

The demand for natural products in the treatment of dermatological pathologies has boosted the use of bioactive substances such as lavender essential oil (LEO), which stands out for its anti-inflammatory and antioxidant properties and its antimicrobial potential. Biopolymers such as chitosan (CHT) and alginate (ALG) are biodegradable and biocompatible and have proven their viability in biomedical applications such as skin regeneration. The inhibitory effect of LEO on the growth of skin-related bacterial species Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and the fungus Candida albicans was studied by incorporating 1% v/v LEO encapsulated in CHT, ALG, and CHT/ALG membranes. Despite the verification of the antimicrobial effect of all type of membranes, no synergistic effect was observed following the addition of LEO. S. aureus and P. aeruginosa showed the most growth on the different substrates and C. albicans demonstrated the highest inhibition. This is a first approach using microorganisms isolated from clinical samples or skin microbiota. Further investigation would be advisable using more clinical strains for each microorganism to validate their biomedical applicability.

Thiosulfinate-Enriched Allium sativum Extract Exhibits Differential Effects between Healthy and Sepsis Patients: The Implication of HIF-1α

Garlic (Allium sativum) has historically been associated with antioxidant, immunomodulatory, and microbiocidal properties, mainly due to its richness in thiosulfates and sulfur-containing phytoconstituents. Sepsis patients could benefit from these properties because it involves both inflammatory and refractory processes. We evaluated the effects of thiosulfinate-enriched Allium sativum extract (TASE) on the immune response to bacterial lipopolysaccharide (LPS) by monocytes from healthy volunteers (HVs) and patients with sepsis. We also explored the TASE effects in HIF-1α, described as the key transcription factor leading to endotoxin tolerance in sepsis monocytes through IRAK-M expression. Our results showed TASE reduced the LPS-triggered reactive oxygen species (ROS) production in monocytes from both patients with sepsis and HVs. Moreover, this extract significantly reduced tumor necrosis factor (TNF)-α, interleukin-1β, and interleukin-6 production in LPS-stimulated monocytes from HVs. However, TASE enhanced the inflammatory response in monocytes from patients with sepsis along with increased expression of human leukocyte antigen-DR. Curiously, these dual effects of TASE on immune response were also found when the HV cohort was divided into low- and high-LPS responders. Although TASE enhanced TNFα production in the LPS-low responders, it decreased the inflammatory response in the LPS-high responders. Furthermore, TASE decreased the HIF-1α pathway-associated genes IRAK-M, VEGFA and PD-L1 in sepsis cells, suggesting HIF-1α inhibition by TASE leads to higher cytokine production in these cells as a consequence of IRAK-M downregulation. The suppression of this pathway by TASE was confirmed in vitro with the prolyl hydroxylase inhibitor dimethyloxalylglycine. Our data revealed TASE’s dual effect on monocyte response according to status/phenotype and suggested the HIF-1α suppression as the possible underlying mechanism.

Tailor-Made Bio-Based Non-Isocyanate Polyurethanes (NIPUs)

Non-isocyanate polyurethanes (NIPUs) based on biobased polyamines and polycarbonates are a sustainable alternative to conventional polyurethanes (PU). This article discloses a novel method to control the crosslinking density of fully biobased isocyanate-free polyurethanes, synthesized from triglycerides carbonated previously in scCO₂ and different diamines, such as ethylenediamine (EDA), hexamethylenediamine (HMDA) and Priamine^TM-1075 (derived from a dimerized fatty acid). As capping substances, water or bioalcohols are used in such a way that the crosslinking density can be adjusted to suit the requirements of the intended application. An optimization of the NIPU synthesis procedure is firstly carried out, establishing the polymerization kinetics and proposing optimal conditions set for the synthesis of the NIPUs. Then, the influence of the partial blocking of the active polymerization sites of the carbonated soybean oil (CSBO), using monofunctional amines, on the physical properties of the NIPUS is explored. Finally, the synthesis of fully biobased NIPUs with a targeted crosslinking density is achieved using hybrid NIPUs, employing partially carbonated oil and H₂O or ethanol as blockers to achieve the desired physical properties in a very precise manner.

Glycolysis of Polyurethanes Composites Containing Nanosilica

Rigid polyurethane (RPU) foams have been successfully glycolyzed by using diethylene glycol (DEG) and crude glycerol (CG) as transesterification agents. However, DEG did not allow to achieve a split-phase process, obtaining a product with low polyol purity (61.7 wt %). On contrary, CG allowed to achieve a split-phase glycolysis improving the recovered polyol purity (76.5%). This is an important novelty since, up to now, RPUs were glycolyzed in single-phase processes giving products of low polyol concentration, which reduced the further applications. Moreover, the nanosilica used as filler of the glycolyzed foams was recovered completely pure. The recovered polyol successfully replaced up to 60% of the raw polyol in the synthesis of RPU foams and including the recovered nanosilica in the same concentration than in glycolyzed foam. Thus, the feasibility of the chemical recycling of this type of polyurethane composites has been demonstrated. Additionally, PU foams were synthesized employing fresh nanosilica to evaluate whether the recovered nanosilica has any influence on the RPU foam properties. These foams were characterized structurally, mechanically and thermally with the aim of proving that they met the specifications of commercial foams. Finally, the feasibility of recovering the of CG by vacuum distillation has been demonstrated.

Dataset of working mPEG-alkyne with scCO2

This article contains data related to the research article entitled “Carbon dioxide sorption and melting behavior of mPEG-alkyne”. The presented data gives information on the thermodynamics properties of the solvent and the polymer. The time saturation of mPEG-alkyne in supercritical carbon dioxide (scCO₂) was evaluated in a high-pressure variable volume cell in different period of time at different pressure at the same temperature.

The effects of pressure and temperature on the density of CO₂ when it is above supercritical conditions are determined with Sanchez Lacombe and Bender Equation and compared with the NIST database and values of equation of Bender. The characteristic parameters of CO₂ were determined with the equations proposed by Chengyong Wang et al. [1] and the sum of squared error was calculated for each parameter.

Furthermore in this work the solubility data of scCO₂/polymer mixture were correlated with Sanchez Lacombe Equation of State (SL EOS) and Heuristic model proposed by Irene Pasquali et al. [2]. This work describes the methodology for solving the SL EOS between the polymer and scCO₂ and the procedure of determining the solubility parameter with the group contribution method necessary to apply the heuristic model is described.

Synthesis and Operating Optimization of the PEG Conjugate via CuAAC in scCO2

A new sustainable green protocol for obtaining polyethylene glycol (PEG) conjugates, with a prototype molecule, which in this work was coumarin, by means of click chemistry is presented. The organic solvents commonly used for this type of reaction were replaced by supercritical carbon dioxide (scCO₂). The synthesis and characterization of PEG-coumarin were successfully reported using FTIR, ¹H NMR, and MALDI TOF. Subsequently, a preliminary study was carried out using the response surface methodology to examine the variables that most affect the use of scCO₂ as a reaction medium. The main effects caused by these variables, individually and their binary interaction, have been estimated. The response surface methodology has been used in this work to screen variables using a factorial design 2³. The p-values of temperature and pressure were 0.006 and 0.0117, being therefore the most significant variables of the response surface methodology study. Subsequently, a more intensive study has been carried out on the variables that have shown the greatest significant effect on reaction performance where an 82.32% synthesis success was achieved, which broadens the scope of the use of scCO₂ as a reaction medium. The conjugated coumarin with mPEG-alkyne and coumarin were evaluated for their in vitro antioxidant activities by the DPPH radical scavenging assay and were found to exhibit substantial activities. The click product showed comparable or even better efficacy than the initial coumarin.

Synthesis of rigid polyurethane foams from phosphorylated biopolyols

Renewable resources are playing a key role on the synthesis of biodegradable polyols. Moreover, the incorporation of covalently linked additives is increasing in importance in the polyurethane (PU) market. In this work, previously epoxidized grape seed oil and methyl oleate were transformed into phosphorylated biopolyols through an acid-catalyzed ring-opening hydrolysis in the presence of H₃PO₄. The formation of phosphate polyesters was confirmed by FT-IR and ³¹P-NMR. However, the synthesis of a high-quality PU rigid foam was not possible using exclusively these polyols attending to their low hydroxyl value. In that way, different rigid PU foams were prepared from the phosphorylated biopolyols and the commercial polyol Alcupol R4520. It was observed that phosphorylated biopolyols can be incorporated up to a 57 wt.% in the PU synthesis without significant structural changes with respect to the commercial foam. Finally, thermogravimetric and EDAX analyses revealed an improvement of thermal stability by the formation of a protective phosphorocarbonaceous char layer.

Recycling of polyurethanes from laboratory to industry, a journey towards the sustainability

The recycling of any kind of plastic to convert it in valuable products is one of the main challenges of today's society. Besides, if the recycling process is itself green, then it would be a great achievement. This paper reviews the way covered from the first attempts of reusing the polyurethane (PU) scraps as a filler for cushions to the last chemical routes employing green recycling agents. Polyurethane is the 6th most used polymer all over the world with a production of 18 millions tons per year, which means a daily production of PU specialties greater than 1 million of cubic meters, equivalent to the volume of the Empire State Building. The thermostable nature of the majority of the polyurethanes specialties has made that the preferred solution for their recycling are the chemical recycling processes. Among them, glycolysis is the one that receives a greater attention from an industrial point of view, so this review puts the spotlight on it. However, the existing reviews in literature do not paid a special attention on glycolysis and only give a superficial description of the process. Nevertheless, in the present review, the scientific literature relative to glycolysis is completely reviewed, updated and ordered according the type of PU specialty recycled. Additionally, the other main chemical recycling processes are also revisited in a more extended and deeper way than in the previous approaches to this topic. Moreover, it is crucial to take into account that some of these technologies, which were described in the literature as promising technologies at laboratory scale are now commercial processes running at industrial scale. For that reason, it is essential to remark that the present review comprises not only a detailed state of art of the scientific literature on the subject, also includes a detailed revision of the past and running on pilot plants and industrial facilities, including several patents, which has never been covered in the current literature. Moreover, this review also describes the most recent studies employing crude glycerol (biodiesel subproduct) as an economic, sustainable and environmental friendly cleavage agent, which should lead the way to the industrial implantation of split-phase glycolysis in a near future, providing high quality recovered products, susceptible of replacing raw ones in the synthesis of new PU specialties. What is more, this review intends that any reader could know and understand the reactions involved in the polyurethane chemistry and recycling, the main polyurethanes types and the fundamentals of the recycling strategies in order to comprehend what are the advantages and drawbacks of each recycling process as starting point for looking for new advantageous alternatives from an environmental, technical and economic point of view. Broader context. This paper reviews the main advances in the polyurethane (PU) recycling field, from laboratory and academia processes to pilot plant and industrial scale ones, including the most relevant patents in the subject. Opposite to other common used plastics, PUs are not polymerization but condensation polymers, synthesized from polyols and isocyanates. The wide diversity of polyols and isocyanates allows the synthesis of numerous different compounds covering a huge range of applications. As a direct consequence of their commercial success, an increasing quantity of PU waste is being disposed by landfilling in the last decades. Such waste comprises not only post-consumer products but also scrap from slabstock manufacturing, which can reach the 10% of the total foam production. However, the massive enforcement of the environmental laws is pointing out a new route in the polymer waste removal sector based in the polymer recycling, and this fact has placed the research in waste treatment as one of the most prolific topics nowadays. In fact, polymer recycling processes have experienced a growing attention from the research and industrial worlds as a direct result of the enforcement of the environmental legislations. Hence, it is essential to develop new environmental sustainable recycling processes with the aim of conserving the natural resources, reducing the amount of waste disposed in landfills and enhancing the sustainability for forthcoming generation.

A 3D electro-mechanical continuum model for simulating skeletal muscle contraction

A thermodynamically consistent three-dimensional electro-mechanical continuum model for simulating skeletal muscle contraction is presented. Active and passive responses are accounted for by means of a decoupled strain energy function into passive and active contributions. The active force is obtained as the maximum tetanic force penalized by two functions that consider the external stimulus frequency and the overlap between actin and myosin filaments. Passive response is modelled by a transversely isotropic strain energy function. The robustness of the model is analyzed by means of finite element simulations that reproduce the one-dimensional isometric, concentric and eccentric contractions in a simplified model of a muscle. The model has also been implemented to reproduce isometric and concentric contractions on a three-dimensional finite element model of the rat tibialis anterior (TA) muscle. The finite element model was obtained from magnetic resonance imaging and the preferential directions associated with the collagen and muscular fibres were considered. The proposed model was able to reproduce the observed experimental response of the active force generated by the isolated rat TA muscle during isometric and concentric contractions. In addition, the predicted force-velocity relationship is in good agreement with experimental data reported for the fast-twitch extensor digitorum longus (e.d.l) muscle of male rats.

Cervical spinal cord injury in the adult rat: assessment of forelimb dysfunction

Traumatic injury to the adult human spinal cord most frequently occurs at the mid-to-low cervical segments and produces tetraplegia. To investigate treatments for improving upper extremity function after cervical spinal cord injury (SCI), three behavioral tests were examined for their potential usefulness in evaluating forelimb function in an adult rat model that mimics human low cervical SCI. Testing was conducted pre- and up to 4 weeks post-operation in adult female rats subjected to either contusion injury at the C7 spinal cord segment or sham-surgery. Modified Forelimb Tarlov scales revealed significant proximal and distal forelimb extension dysfunction in lesion rats at l-to-4 weeks post-cervical SCI. The Forelimb Grip Strength Test showed a significant decrease in forelimb grip strength of lesion rats throughout the 4 weeks post-cervical SCI. Significant deficits in reach and pellet retrieval by lesion rats were measured at l-to-4 weeks post-cervical SCI with the conditioned pellet retrieval Staircase Test. The results demonstrate that these qualitative and quantitative forelimb behavioral tests can be used to evaluate forelimb function following low cervical SCI and may be useful to investigate treatments for improving forelimb function in these lesions.

Production of biodiesel from winery waste: extraction, refining and transesterification of grape seed oil

In regions with a large wine production the usage of their natural waste to make biodiesel can result an interesting alternative. In this work, different methods of extraction, refining and transesterification of grape seed oil were assayed. Two techniques of oil extraction were compared: solvent extraction and pressing. Two conventional transesterifications of the refined oil were carried out using methanol and bioethanol, being the methyl and ethyl ester contents higher than 97 wt.%. Finally, several in situ transesterifications were done. In situ transesterification did not reach either the oil yield extraction or the alkyl ester contents but the obtained biodiesel had better oxidation stability in comparison with the conventional process.

Study of the solubility and stability of polystyrene wastes in a dissolution recycling process

Dissolution with suitable solvents is one of the cheapest and more efficient processes for polystyrene waste management. In this work the solubility of polystyrene foams in several solvents benzene, toluene, xylene, tetrahydrofuran, chloroform, 1,3-butanediol, 2-butanol, linalool, geraniol, d-limonene, p-cymene, terpinene, phellandrene, terpineol, menthol, eucalyptol, cinnamaldheyde, nitrobenzene, N,N-dimethylformamide and water has been determined. Experimental results have shown that to develop a "green process" the constituents of essential oils, d-limonene, p-cymene, terpinene, phellandrene, are the most appropriate solvents. The action of these solvent does not produce any degradation of polymer chains. The solubility of the polymer in the mentioned solvents at different temperatures has been investigated. The solvent can be easily recycled by distillation.

An experimental study of the mouse skin behaviour: Damage and inelastic aspects

Samples of male and female mice skin were tested under monotonic and cyclic loading to mechanically characterize the tissue for large deformations. Cyclic tests have shown a typical Mullins effect widely known for elastomers and other soft tissues. No statistical difference was found in the maximum stretch of the sample after the fifth loading cycle for male (1.26 +/- 0.035) and female (1.18 +/- 0.083). However, larger dispersion was obtained for the maximum stress for both genders, 0.61 +/- 0.16 MPa for male and 0.78 +/- 0.32 MPa for female. Results show the presence of inelastic strain and stress softening in the skin at large deformations. They also have shown how stress softening and residual strain change with the magnitude of the applied load. Good correlation was observed between the residual strain and the maximum strain previously attained by the sample during loading for all samples. However, the correlation was different between genders.

[Total plasma homocysteine concentrations in Puerto Rican patients with ischemic heart disease]

INTRODUCTION AND OBJECTIVES

In Puerto Rico, it has been established that although coronary disease is the leading cause of death, the population has a lower incidence of coronary disease than in the continental United States. In addition, the severity of the disease is less aggressive in terms of a lower incidence of ventricular tachycardia and sudden death. One factor that could contribute to the lower incidence of coronary disease in Puerto Rico is that our population might have lower total plasma homocysteine concentrations (tHcys) than in the continental United States. Our main objective was to measure tHCys in the Puerto Rican population with atherosclerotic cardiovascular disease (ACD).

METHODS

We randomly measured tHcys concentrations in seventy Puerto Rican patients who were hospitalized at the Cardiovascular Center of Puerto Rico and the Caribbean (UPR Division).

RESULTS

The mean tHCys concentration in these patients is similar to those reported for the Framingham study when adjusted by age (11.2 vs. 11.8 micromol/l). In the Puerto Rican population, males had a higher tHcys concentration than females (11.7 vs 9.5 micromol/l, p = 0.07). In addition, we did not see an increase of tHcys concentrations in diabetic patients when compared with non-diabetics (10.1 vs. 11.2 micromol/l, p = 0.74). We did not see a direct correlation between tHcys concentrations and heart condition as measured by coronary angiography (normal = 11.1 micromol/l, light = 10.5 micromol/l, moderate = 10.9 micromol/l, severe = 10.5 micromol/l; Kruskal-Wallis = 0.45) either.

CONCLUSION

These results suggest that tHcys concentration is not a good predictor of the seriousness of ACD in the Puerto Rican patient population.

C terminus of infectious bursal disease virus major capsid protein VP2 is involved in definition of the T number for capsid assembly

Infectious bursal disease virus (IBDV), a member of the Birnaviridae family, is a double-stranded RNA virus. The IBDV capsid is formed by two major structural proteins, VP2 and VP3, which assemble to form a T=13 markedly nonspherical capsid. During viral infection, VP2 is initially synthesized as a precursor, called VPX, whose C end is proteolytically processed to the mature form during capsid assembly. We have computed three-dimensional maps of IBDV capsid and virus-like particles built up by VP2 alone by using electron cryomicroscopy and image-processing techniques. The IBDV single-shelled capsid is characterized by the presence of 260 protruding trimers on the outer surface. Five classes of trimers can be distinguished according to their different local environments. When VP2 is expressed alone in insect cells, dodecahedral particles form spontaneously; these may be assembled into larger, fragile icosahedral capsids built up by 12 dodecahedral capsids. Each dodecahedral capsid is an empty T=1 shell composed of 20 trimeric clusters of VP2. Structural comparison between IBDV capsids and capsids consisting of VP2 alone allowed the determination of the major capsid protein locations and the interactions between them. Whereas VP2 forms the outer protruding trimers, VP3 is found as trimers on the inner surface and may be responsible for stabilizing functions. Since elimination of the C-terminal region of VPX is correlated with the assembly of T=1 capsids, this domain might be involved (either alone or in cooperation with VP3) in the induction of different conformations of VP2 during capsid morphogenesis.

First asymmetric hetero Diels-Alder reaction of 1-sulfinyl dienes with nitroso derivatives. A new entry to the synthesis of optically pure 1,4-imino-L-ribitol derivatives

Hetero Diels-Alder (HDA) cycloaddition of chiral 1-p-tolylsulfinyl-1,3-pentadiene with benzyl nitrosoformate, under mild conditions, yields 2H-1,2-oxazine 3 with complete regioselectivity and pi-facial diastereoselectivity. Sequential osmylation and protection of the resulting glycol gives the oxazine 5 which is directly transformed into enantiomerically pure 1,4,5-trideoxy-1,4-imino-L-ribitol 8 by reduction under Pd/C.

Total plasma homocysteine concentrations in Puerto Rican patients with presumptive atherosclerotic coronary disease

BACKGROUND

In Puerto Rico, it has been established that although coronary heart disease is the leading cause of death, the population has a lower incidence of coronary disease than the continental United States. In addition, the severity of the disease is less aggressive in terms of a lower incidence of ventricular tachycardia and sudden death. A factor in the lower incidence of coronary disease in Puerto Rico could be a lower total plasma homocysteine concentration (tHcys) in our population.

METHODS

We randomly measured tHcys concentrations in seventy-two Hispanic patients who were hospitalized for coronary angiography at the Cardiovascular Center of Puerto Rico and the Caribbean (UPR Division).

RESULTS

The mean tHCys concentration in our patient population is similar than that reported for the Framingham study when adjusted by age (11.2 mumol/L vs. 11.8 mumol/L). In the Puerto Rican population, males had a higher tHcys concentration than females but this difference was not statistically significant (10.9 mumol/L vs. 9.4 mumol/L, p = 0.09). In addition, we did not see an increase of tHcys concentrations in diabetic patients when compared with nondiabetics (10.1 mumol/L vs. 10.3 mumol/L, p = 0.73). Neither we saw a direct correlation between tHcys concentrations and atherosclerosis as measured by coronary angiography (normal = 10.9 mumol/L, mild = 8.6 mumol/L, moderate = 10.9 mumol/L, severe = 10.5 mumol/L; ANOVA = 0.29).

CONCLUSIONS

These results suggest that tHcys concentration is not a good predictor of atherosclerotic coronary disease in our patient population.

Expression of ORF A1 of infectious bursal disease virus results in the formation of virus-like particles

A recombinant vaccinia virus inducibly expressing ORF A1 of infectious bursal disease virus (IBDV) has been constructed and characterized. Cells infected with this recombinant virus express the IBDV polyprotein, which is proteolytically processed to give mature VP2, VP3, and VP4 polypeptides. An electron microscopy study revealed that the cytoplasm of cells infected with the recombinant virus contains abundant IBDV-like particles (VLP). These VLP form close-packed paracrystalline arrays that are specifically recognized by anti-IBDV antibodies. The size and morphology of purified VLP were found to be akin to those of authentic IBDV particles.

Analysis of antiretroviral nucleosides by electrospray ionization mass spectrometry and collision induced dissociation

Antiretroviral nucleoside drugs used against the human immunodeficiency virus (HIV) infection have been analyzed using negative ion electrospray ionization (ESI) mass spectrometry and collision-induced dissociation (CID-MS/MS). Mass fragmentation of azidothymidine (AZT), didanosine (ddI), dideoxycytidine (ddC) and dideoxythiacytidine (3TC) were obtained at different cone voltages and collision energies. Fragmentation of purines and pyrimidines occurred by different pathways. For purines (ddI), the fragmentation was similar to those found in endogenous nucleosides; mainly the pseudo molecular ion is present (M-H)- and a cleavage through the glycosidic bond forming (B)- was observed. For pyrimidines (AZT, ddC, 3TC), the fragmentation pathways were different from endogenous nucleosides; for AZT, the fragmentation occurred primarily through the elimination of the azido group in the 3'-position (M-H2-N3)-, whereas ddC and 3TC presented more complex fragmentation patterns. For ddC, fragmentation appeared to be dominated by a retro Diels-Alder mechanism (M-CONH)-. For 3TC, the sulfur atom in the sugar moiety provided greater stability to the charge, producing fragments where the charge resided initially in the dideoxyribose (M-C2O2H6)-.

Azidothymidine triphosphate determination using micellar electrokinetic capillary chromatography

There is a need to perform pharmacokinetic studies in the pediatric population utilizing antiretroviral drugs, which have shown effectiveness for the treatment of human immunodeficiency virus (HIV). In order to establish a relationship between efficacy and toxicity, we need to detect and quantitate these antiretroviral nucleosides and their metabolites at the intracellular level. Micellar electrokinetic capillary chromatography (MECC) was used for the separation of five nucleotides: cytidine triphosphate (CTP), adenosine triphosphate (ATP), thymidine triphosphate (TTP), guanosine triphosphate (GTP) and azidothymidine triphosphate (AZT-TP). Attomoles of these nucleotides were satisfactorily resolved in short run times with high peak efficiencies. In addition, nanoliters of sample volume were used to perform the analysis using ultraviolet (UV) detection at 254 nm.

The major antigenic protein of infectious bursal disease virus, VP2, is an apoptotic inducer

Infectious bursal disease virus (IBDV) is the causative agent of an economically important poultry disease. Vaccinia virus recombinants expressing the IBDV mature structural capsid proteins VP2 and VP3 were generated by using vectors for inducible gene expression. Characterization of these recombinant viruses demonstrated that expression of VP2 leads to induction of apoptosis in a variety of mammalian cell lines. Transfection of cell cultures with a expression vector containing the VP2 coding region under the control of the immediate-early promoter-enhancer region of human cytomegalovirus also triggers programmed cell death. The apoptotic effect of VP2 is efficiently counteracted by coexpression of the proto-oncogene bcl-2. The results presented demonstrate that VP2 is a bona fide apoptotic inducer. Evaluation of the significance of this finding for the virus life cycle must await further research.

Cloning of the gp63 surface protease of Leishmania infantum. Differential post-translational modifications correlated with different infective forms

The Leishmania cell surface virulence factor gp63 is a protease family that plays an important role in the survival of the parasite protozoon into the host macrophages. We have cloned and characterised the gp63 gene from L. infantum. The sequence analysis of the gene indicates the existence of a high degree of conservation with the other old world species L. major and L. donovani. The similarity is lower with new world species with the exception of L. chagasi which shows a strikingly high percentage of identity (99-100%). In L. infantum the gp63 gene expresses two polypeptides of 58 and 60 kDa, respectively, which show a similar proteolytic activity. The 60 kDa polypeptide is expressed during the whole life cycle of the promastigote form of the parasite with a moderate increase at the stationary phase of growth while the 58 kDa product, although slightly present in the logarithmic phase, notable increases its expression during the highly infectious stationary phase. RNA analysis showed that the presence in L. chagasi of these two polypeptides correlates with two RNA molecules and with the degree of parasite infectivity, whereas in the case of L. infantum a single 3 kb messenger RNA is detected through the whole promastigote life cycle. Our data indicate that in L. infantum, the differences in gene expression of the gp63 protease family according to parasite phase of growth seem to be due to a differential pattern of glycosilation of the polypeptides which correlates with the different infective forms of the promastigote form of the parasite.

The African swine fever virus IAP homolog is a late structural polypeptide

The analysis of the complete nucleotide sequence of the African swine fever virus genome has revealed the existence of a number of genes potentially capable of modifying the host's response to the virus infection. In this report, we describe the results of the characterization of the A224L gene that encodes a novel member of the family of apoptosis inhibitors known as IAP proteins. A224L is expressed during the late phase of the infectious cycle, and its polypeptide product is assembled into virus particles.

Vectors for the genetic manipulation of African swine fever virus

Plasmid vectors designed to facilitate the genetic manipulation of African swine fever virus (ASFV) are described. Our results demonstrate that the beta-glucuronidase enzyme (GUS) can be used to follow gene expression in ASFV-infected cells. Infectious plaques formed by ASFV expressing GUS are visually detectable, thus providing a simple and highly sensitive method for the selection of ASFV recombinants. These and previous results have allowed us to construct two chimeric gene cassettes that constitute the basic tools for the generation of vectors to carry out the deletion of multiple target sequences from the ASFV genome. These cassettes, formed by: (a) a virus promoter; (b) the coding sequence of a reporter gene, either Lac Z or gusA; and (c) a strong signal for the 3' end formation of ASFV mRNAs, can be easily isolated by endonuclease restriction from their corresponding plasmid vectors. A general insertion/coexpression plasmid vector, pEPV2, has also been constructed. pEPV2 facilitates the insertion of foreign genes, together with the Lac Z reporter, into the thymidine kinase locus of ASFV. The functionality of pEPV2 has been tested by generating a recombinant ASFV expressing the luciferase gene. The vectors presented in this report constitute the first reported set of tools for the genetic manipulation of ASFV.

The DNA polymerase-encoding gene of African swine fever virus: sequence and transcriptional analysis

The putative DNA polymerase-encoding gene of African swine fever virus has been sequenced. The gene, designated G1207R, is located in the central region of the viral genome, and encodes a protein of 1207 amino acids (aa) with a predicted M(r) of 139,835. The gene is transcribed at both early and late stages of infection into a 4.1-kb RNA. Transcription is initiated at tsp, 8 nucleotides (nt) upstream from the start codon. Open reading frame (ORF) G1207R contains four direct repeats in tandem close to the 3'-end. Each repeat consists of 12 nt, coding for the reiterated sequence, K/NPAG. The deduced aa sequence of G1207R shows significant similarity with DNA polymerases from cellular and viral origin, belonging to the alpha-like family of DNA polymerases. In particular, the G1207R protein presents a colinear arrangement of all the 3'-->5' exonuclease and polymerization highly conserved aa regions characteristic of this group of DNA-dependent DNA polymerases.

Two putative African swine fever virus helicases similar to yeast 'DEAH' pre-mRNA processing proteins and vaccinia virus ATPases D11L and D6R

Two open reading frames (ORFs) of African swine fever virus (ASFV) encoding putative helicases have been sequenced. The two genes, termed D1133L and B962L, are located in the central region of the viral genome, but are separated by about 40 kb of DNA. Both genes are expressed late during ASFV infection of Vero cells, after replication of viral DNA has begun. Contiguous to D1133L, three other ORFs (D129L, D79L and D339L), encoding putative proteins of unknown function, have been sequenced. Proteins D1133L and B962L contain the amino acid motifs that characterize helicases of superfamily II. D1133L is most similar to a group of putative helicases which includes two proteins of vaccinia virus (D11L and D6R) involved in transcription of the viral genome, their homologues in other poxviruses, the protein encoded by ORF 4 of the yeast plasmids, pGKL2 and pSKL, and the previously identified ASFV protein, Q706L. B962L resembles a group of RNA-helicase-like proteins which includes three proteins of Saccharomyces cerevisiae involved in pre-mRNA splicing (PRP2, PRP16 and PRP22), Drosophila melanogaster KURZ and MLE, and vaccinia virus 18R.

African swine fever virus thymidylate kinase gene: sequence and transcriptional mapping

A putative thymidylate kinase gene of African swine fever virus has been identified at the left end of the SalI I' fragment of the virus genome. The gene, designated A240L, has the potential to encode a protein of 240 amino acids with an M(r) of 27,754 and is transcribed early after infection. Primer extension analysis indicates that transcription is initiated a short distance from the first ATG codon of open reading frame A240L. The deduced amino acid sequence of this open reading frame shows significant similarity with the human, yeast and vaccinia virus thymidylate kinases, the degree of identity being 23.7, 25 and 23.5%, respectively. The putative African swine fever virus thymidylate kinase sequence is essentially collinear with the other thymidylate kinase sequences, but contains a carboxy-terminal extension of 37 amino acids rich in glutamic and aspartic acids. The A240L protein conserves the ATP-binding and nucleotide/nucleoside-binding domains characteristic of thymidylate kinases.

Keratoconjunctivitis sicca and diabetes mellitus in a dog

Diabetes mellitus and keratoconjunctivitis sicca were diagnosed in a female Poodle. The dog was treated for diabetes and keratoconjunctivitis sicca until blood glucose concentrations were within normal limits. Treatment for keratoconjunctivitis sicca was suspended then, and signs of this disorder did not appear again. Most of the factors known to predispose to keratoconjunctivitis sicca were not applicable to this dog. On the basis of observations made in this dog, we suggest that diabetes mellitus and keratoconjunctivitis sicca may be linked. Clinical signs of the disorders developed simultaneously and resolved when diabetes mellitus was controlled with insulin.

Evaluation of total protein content in tears of dogs by polyacrylamide gel disk electrophoresis

Concentration of total proteins was measured and sodium dodecyl sulfate-polyacrylamide gel disk electrophoresis was performed on tear and plasma samples obtained from 26 healthy dogs, and the results were compared. Mean +/- SEM concentration of total proteins in tears was 0.63 +/- 0.04 g/dl, and significant effects of age or gender were not found. The protein composition of tears in dogs was complex, and bands from light and heavy chains of immunoglobulins were identified by electrophoresis.