AAV capsid design: A Goldilocks challenge.

In vivo therapeutic gene transfer has emerged as a novel class of medicines. Its feasibility relies on the safe and efficacious delivery of genetic cargo to the appropriate targets. The adeno-associated virus (AAV) vector manifested itself as a preferred gene delivery vehicle enabling therapeutic gene expression for several clinical indications. Here, we cover the recent trends in AAV capsid engineering to enhance its targeting specificity, safety, and endurance. While each and every desirable trait can be individually remodeled, combining several attributes in one capsid amounts to a significant engineering challenge. Taking advantage of virion structure and phylogenetics, harnessing directed evolution, sequence analyses, and machine learning, researchers develop novel capsid variants to realize the goals of safe and enduring gene therapy.

Expanding the time interval between ovulation triggering and oocyte injection: does it affect the embryological and clinical outcome?

STUDY QUESTION: Is the time interval between ovulation triggering and oocyte denudation/injection associated with embryological and clinical outcome after ICSI? SUMMARY ANSWER: Expanding the time interval between ovulation triggering and oocyte denudation/injection is not associated with any clinically relevant impact on embryological or clinical outcome. WHAT IS KNOWN ALREADY: The optimal time interval between ovulation triggering and insemination/injection appears to be 38-39 h and most authors agree that an interval of >41 h has a negative influence on embryological and clinical pregnancy outcomes. However, in ART centres with a heavy workload, respecting these exact time intervals is frequently challenging. Therefore, we questioned to what extent a wider time interval between ovulation triggering and oocyte injection would affect embryological and clinical outcome in ICSI cycles. STUDY DESIGN, SIZE, DURATION: A single-centre retrospective cohort analysis was performed including 8811 ICSI cycles from 2010 until 2015. Regarding the time interval between ovulation triggering and oocyte injection, seven categories were considered: <36 h, 36 h, 37 h, 38 h, 39 h, 40 h and ≥41 h. In all cases, denudation was performed immediately prior to injection. The main outcome measures were oocyte maturation, fertilization and embryo utilization rate (embryos adequate for transfer or cryopreservation) per fertilized oocyte. Clinical pregnancy rate (CPR) and live birth rate (LBR) were considered as secondary outcomes. Utilization rate, CPR and LBR were subdivided into two groups according to the day of embryo transfer: Day 3 or Day 5. PARTICIPANTS/MATERIALS, SETTING, METHODS: During the study period, oocyte retrieval was routinely performed 36 h post-triggering except in the <36 h group. The interval of <36 h occurred only if OR was carried out before the planned 36 h trigger interval and was followed by immediate injection. Only cycles with fresh autologous gametes were included. The exclusion criteria were: injection with testicular/epididymal sperm, managed natural cycles, conventional IVF, combined conventional IVF/ICSI, preimplantation genetic testing and IVM cycles. Female age, number of oocytes, pre-preparation sperm concentration, post-preparation sperm concentration and motility, day of transfer, number of embryos transferred and quality of the best embryo transferred were identified as potential confounders. MAIN RESULTS AND THE ROLE OF CHANCE: Among the seven interval groups, adjusted mean maturation rates ranged from 76.4% to 83.2% and differed significantly (P < 0.001). Similarly, there was a significant difference in adjusted mean fertilization rates (range 69.2-79.3%; P < 0.001). The adjusted maturation and fertilization rates were significantly higher when denudation/injection was performed >41 h post-triggering compared to 38 h post-triggering (reference group). Oocyte denudation/injection at <36 h post-triggering had no significant effect on maturation, fertilization or embryo utilization rates compared to injection at 38 h. No effect of the time interval was observed on CPRs and LBRs, after adjusting for potential confounders. When oocyte injection was performed before 36 h the adjusted analysis showed that compared to 38 h after ovulation triggering the chance of having a live birth tends to be lower although the difference was not statistically significant (odds ratio 0.533, 95% CI: 0.252-1.126; P = 0.099). Injection ≥41 h post-triggering did not affect LBR compared to injection at 38 h post-ovulation. LIMITATIONS, REASONS FOR CAUTION: As this is a large retrospective study, the influence of uncontrolled variables cannot be excluded. These results should not be extrapolated to other ART procedures such as IVM, conventional IVF or injection with testicular/epididymal sperm. WIDER IMPLICATIONS OF THE FINDINGS: Our results indicate that the optimal injection time window may be less stringent than previously thought as both embryological and clinical outcome parameters were not significantly affected in our analysis. This is reassuring for busy ART centres that might not always be able to follow strict time intervals. STUDY FUNDING/COMPETING INTEREST(S): No funding. The authors declare no conflict of interest related to the present study. TRIAL REGISTRATION NUMBER: N/A.

Technological mapping and trends in photobioreactors for the production of microalgae.

Photobioreactors (PBRs) are equipment of central importance for the massive cultivation of microalgae, providing controlled conditions for high cell productivity. There are a few popular PBR designs, with contrasting advantages and limitations, such as poor light distribution, mass transfer, or hydrodynamic behavior. Due to the environmental concerns in recent decades and the discovery of new, useful microalgal metabolites, the interest in finding alternatives to solve technological bottlenecks of PBRs has intensified. In this process, new geometries, materials, and modes of light supply were developed, generating a significant scientific and technological output, reported in papers and patents. We present a technological landscape analysis of photobioreactor design, focusing on improvements of the classical geometries and trends in industrial photobioreactors. The analysis of 412 patent documents showed a surge in innovation filing since 2005 and a reduction in the number of new documents along the last decade. The recent efforts in design improvement, the leading countries, institutes and companies that innovate, and the trends in PBR technology are presented and discussed.

Intracellular localisation of platelet-activating factor during mammalian embryo development in vitro: a comparison of cattle, mouse and human.

Platelet-activating factor (PAF) is a well-known marker for embryo quality and viability. For the first time, we describe an intracellular localisation of PAF in oocytes and embryos of cattle, mice and humans. We showed that PAF is represented in the nucleus, a signal that was lost upon nuclear envelope breakdown. This process was confirmed by treating the embryos with nocodazole, a spindle-disrupting agent that, as such, arrests the embryo in mitosis, and by microinjecting a PAF-specific antibody in bovine MII oocytes. The latter resulted in the absence of nuclear PAF in the pronuclei of the zygote and reduced further developmental potential. Previous research indicates that PAF is released and taken up from the culture medium by preimplantation embryos invitro, in which bovine serum albumin (BSA) serves as a crucial carrier molecule. In the present study we demonstrated that nuclear PAF does not originate from an extracellular source because embryos cultured in polyvinylpyrrolidone or BSA showed similar levels of PAF in their nuclei. Instead, our experiments indicate that cytosolic phospholipase A2 (cPLA2) is likely to be involved in the intracellular production of PAF, because treatment with arachidonyl trifluoromethyl ketone (AACOCF3), a specific cPLA2 inhibitor, clearly lowered PAF levels in the nuclei of bovine embryos.

Platelet-activating factor acetylhydrolase 1B3 (PAFAH1B3) is required for the formation of the meiotic spindle during in vitro oocyte maturation.

Platelet-activating factor (PAF) is a well-described autocrine growth factor involved in several reproductive processes and is tightly regulated by its hydrolysing enzyme, PAF acetylhydrolase 1B (PAFAH1B). This intracellular enzyme consists of three subunits: one regulatory, 1B1, and two catalytic, 1B2 and 1B3. PAFAH1B3 has remained uncharacterised until now. Here, we report that PAFAH1B3 is present during the different stages of the first meiotic division in bovine, murine and human oocytes. In these species, the PAFAH1B3 subunit was clearly present in the germinal vesicle, while at metaphase I and II, it localised primarily at the meiotic spindle structure. In cattle, manipulation of the microtubules of the spindle by nocodazole, taxol or cryopreservation revealed a close association with PAFAH1B3. On the other hand, disruption of the enzyme activity either by P11, a selective inhibitor of PAFAH1B3, or by PAFAH1B3 antibody microinjection, caused arrest at the MI stage with defective spindle morphology and consequent failure of first polar body extrusion. In conclusion, our results show that one of the catalytic subunits of PAFAH1B, namely PAFAH1B3, is present in bovine, murine and human oocytes and that it plays a functional role in spindle formation and meiotic progression during bovine oocyte maturation.

An improved vitrification protocol for equine immature oocytes, resulting in a first live foal.

BACKGROUND: The success rate for vitrification of immature equine oocytes is low. Although vitrified-warmed oocytes are able to mature, further embryonic development appears to be compromised. OBJECTIVES: The aim of this study was to compare two vitrification protocols, and to examine the effect of the number of layers of cumulus cells surrounding the oocyte during vitrification of immature equine oocytes. STUDY DESIGN: Experimental in vitro and in vivo trials. METHODS: Immature equine oocytes were vitrified after a short exposure to high concentrations of cryoprotective agents (CPAs), or a long exposure to lower concentrations of CPAs. In Experiment 1, the maturation of oocytes surrounded by multiple layers of cumulus cells (CC oocytes) and oocytes surrounded by only corona radiata (CR oocytes) was investigated. In Experiment 2, spindle configuration was determined for CR oocytes vitrified using the two vitrification protocols. In Experiment 3, further embryonic development was studied after fertilisation and culture. Embryo transfer was performed in a standard manner. RESULTS: Similar nuclear maturation rates were observed for CR oocytes vitrified using the long exposure and nonvitrified controls. Furthermore, a lower maturation rate was obtained for CC oocytes vitrified with the short exposure compared to control CR oocytes (P = 0.001). Both vitrification protocols resulted in significantly higher rates of aberrant spindle configuration than the control groups (P<0.05). Blastocyst development only occurred in CR oocytes vitrified using the short vitrification protocol, and even though blastocyst rates were significantly lower than in the control group (P<0.001), transfer of five embryos resulted in one healthy foal. MAIN LIMITATIONS: The relatively low number of equine oocytes and embryo transfer procedures performed. CONCLUSIONS: For vitrification of immature equine oocytes, the use of 1) CR oocytes, 2) a high concentration of CPAs, and 3) a short exposure time may be key factors for maintaining developmental competence.

Effect of different compounds on the induction of laccase production by Agaricus blazei.

Laccases are polyphenol oxidases produced by many fungi and have many applications in textile, food and beverage, and pulp and paper industries. Laccase production can be induced using aromatic or phenolic compounds that mostly affect the transcription of laccase-encoding genes. In this study, we analyzed laccase and biomass production by Agaricus blazei in the presence of different concentrations of nitrogen, copper, and inducers such as pyrogallol, veratryl alcohol, xylidine, vanillin, guaiacol, and ethanol. Laccase production by A. blazei U2-4 reached 43.8 U/mL in the presence of 2.8 g/L nitrogen and 150 µM copper. However, addition of copper to the cultivation medium decreased biomass production. Different compounds differentially induced laccase production by A. blazei. Moreover, different concentrations of these inducers exerted different effects on laccase activity. Ethanol (1.0 mM), guaiacol (0.5 mM), and vanillin (0.5 mM) were the best inducers and increased laccase activity by 120% (A. blazei U2-2), 30% (A. blazei U2-3), and 9% (A. blazei U2-4), respectively. In contrast, pyrogallol and xylidine decreased laccase activity but increased biomass production.

Increasing the cAMP concentration during in vitro maturation of pig oocytes improves cumulus maturation and subsequent fertilization in vitro.

Porcine IVF faces various problems such as incomplete cytoplasmic maturation of the oocyte and polyspermy. Previous studies proved the importance of cAMP in regulating nuclear and cytoplasmic maturation of oocytes. This study investigated the effect of the cAMP-modulating agents 3-isobutyl-1-methylxanthine (IBMX) and dibutyryl cAMP sodium salt (dbcAMP) on several parameters during in vitro production of porcine embryos. First, we wanted to see if oocyte collection in IBMX could meiotically arrest oocytes and, as such, improve synchronization of nuclear and cytoplasmic maturation. To this end, cumulus-oocyte complexes (COCs) were collected from gilts in HEPES-buffered Tyrode balanced salt solution medium with 0.5-mM IBMX or without IBMX. At the end of oocyte collection, the effect of IBMX on chromatin configuration was evaluated. However, no differences could be observed in nuclear configuration between IBMX- and IBMX+ oocytes (P > 0.05). Second, we added dbcAMP during IVM to improve cytoplasmic maturation and evaluated cumulus expansion (lack of adhesion), a disintegrin and metalloproteinase with thrombospondin-like repeats (ADAMTS-1) levels in cumulus cells, fertilization, and blastocyst rates. Cumulus-oocyte complexes were matured in modified North Carolina State University medium 37 with or without 1-mM dbcAMP. Frozen-thawed, epididymal, boar spermatozoa were used for IVF. After IVF, presumed zygotes were cultured for 7 days in North Carolina State University medium 23. Penetration rate decreased in dbcAMP+ (57.3%) compared with dbcAMP- (67.8%), but the polyspermy rate also decreased (43.3% vs. 53.4%, respectively) leading to an increased normal fertilization rate (56.7% vs. 46.6%, respectively; P < 0.05). Only 7.2% of the COCs showed adhesion in dbcAMP+ which was lower than 15.7% in dbcAMP- (P < 0.05) probably because of an upregulation of the ADAMTS-1 protein by dbcAMP. When the adherent oocytes were removed during maturation, no difference could be detected between the blastocyst rate of dbcAMP- and dbcAMP+ (17.1% and 21.0% on Day 7, respectively; P > 0.05). In conclusion, the use of IBMX during collection did not cause a meiotic arrest. Using dbcAMP during IVM caused a greater normal fertilization rate, a lower rate of adherent COCs during IVM, higher levels of ADAMTS-1 in cumulus cells, and an equal blastocyst rate after screening out adherent COCs. These findings contribute to a better understanding of cAMP involvement in porcine oocyte maturation and provide a basis to develop an improved system with less polyspermy and higher blastocyst rates.

Optimum conditions for inducing laccase production in Lentinus crinitus.

Laccases are environmentally friendly alternatives in many important applications such as in bioremediation, biopulping, textile, and the food industry. They have wide substrate specificity, can oxidize a broad range of compounds, and show potential for use in various industrial processes. Therefore, developing methods to increase laccase production is important. In the current study, we aimed to identify optimum conditions for inducing laccase production in the basidiomycete Lentinus crinitus cultivated under varying nitrogen concentrations and in the presence of potential inducers of laccase production, including copper and phenolic compounds. Peak enzymatic activity (11,977 U/L) occurred at higher nitrogen concentrations (2.8 g/L nitrogen). Regardless of the nitrogen concentration, addition of copper increased the laccase activity and decreased mycelial growth, with maximum laccase activity (14,320 U/L) observed at the highest nitrogen concentration combined with 150 mM CuSO4. In addition, ethanol (0.5 or 1.0 mM) and guaiacol (1.5 mM) increased laccase production to 15,000, 14,800, and 14,850 U/L, respectively. Our findings highlighted the optimum conditions for producing L. crinitusderived laccase as potential alternatives to the conventional production and application of the enzyme.

Long term outcome of trapeziectomy with ligament reconstruction/tendon interposition versus thumb basal joint prosthesis.

Several surgical techniques to treat thumb basal joint arthritis have been described. In this study we compared the results of a cemented thumb basal joint with trapeziectomy with a ligament reconstruction and tendon interposition. A questionnaire was sent to all 519 patients, 322 (with 382 procedures) responded. No significant differences were found when comparing impairment, pain, patient satisfaction and disability. Given the fact that the superiority of a prosthesis cannot be proven and the cost of the implant is greater, we recommend the trapeziectomy with ligament reconstruction and tendon interposition as opposed to arthroplasty as the first choice in the treatment of basal joint osteoarthritis of the thumb.

Avascular necrosis of the proximal carpal row of the wrist. A possible complication of bisphosphonate administration.

Reports of coexisting osteonecrosis of more than one carpal bone are rare. We report an osteonecrosis of the entire proximal carpal row of the wrist, started briefly after intravenous bisphosphonate administration. The use of bisphosphonates for the treatment of osteoporosis is increasing. Osteonecrosis of the jaw (ONJ) is one of the known adverse effects during chronic treatment with bisphosphonates. This case is reported to make clinicians aware of a possible causative link between bisphosphonate use and osteonecrosis of other bones.

Novel adeno-associated viral vectors for retinal gene therapy.

Vectors derived from adeno-associated virus (AAV) are currently the most promising vehicles for therapeutic gene delivery to the retina. Recently, subretinal administration of AAV2 has been demonstrated to be safe and effective in patients with a rare form of inherited childhood blindness, suggesting that AAV-mediated retinal gene therapy may be successfully extended to other blinding conditions. This is further supported by the great versatility of AAV as a vector platform as there are a large number of AAV variants and many of these have unique transduction characteristics useful for targeting different cell types in the retina including glia, epithelium and many types of neurons. Naturally occurring, rationally designed or in vitro evolved AAV vectors are currently being utilized to transduce several different cell types in the retina and to treat a variety of animal models of retinal disease. The continuous and creative development of AAV vectors provides opportunities to overcome existing challenges in retinal gene therapy such as efficient transfer of genes exceeding AAV's cargo capacity, or the targeting of specific cells within the retina or transduction of photoreceptors following routinely used intravitreal injections. Such developments should ultimately advance the treatment of a wide range of blinding retinal conditions.

Efficient and stable transduction of dopaminergic neurons in rat substantia nigra by rAAV 2/1, 2/2, 2/5, 2/6.2, 2/7, 2/8 and 2/9.

Dysfunction of the nigrostriatal system is the major cause of Parkinson's disease (PD). This brain region is therefore an important target for gene delivery aiming at disease modeling and gene therapy. Recombinant adeno-associated viral (rAAV) vectors have been developed as efficient vehicles for gene transfer into the central nervous system. Recently, several serotypes have been described, with varying tropism for brain transduction. In light of the further development of a viral vector-mediated rat model for PD, we performed a comprehensive comparison of the transduction and tropism for dopaminergic neurons (DNs) in the adult Wistar rat substantia nigra (SN) of seven rAAV vector serotypes (rAAV 2/1, 2/2, 2/5, 2/6.2, 2/7, 2/8 and 2/9). All vectors were normalized by titer and volume, and stereotactically injected into the SN. Gene expression was assessed non-invasively and quantitatively in vivo by bioluminescence imaging at 2 and 5 weeks after injection, and was found to be stable over time. Immunohistochemistry at 6 weeks following injection revealed the most widespread enhanced green fluorescence protein expression and the highest number of positive nigral cells using rAAV 2/7, 2/9 and 2/1. The area transduced by rAAV 2/8 was smaller, but nevertheless almost equal numbers of nigral cells were targeted. Detailed confocal analysis revealed that serotype 2/7, 2/9, 2/1 and 2/8 transduced at least 70% of the DNs. In conclusion, these results show that various rAAV serotypes efficiently transduce nigral DNs, but significant differences in transgene expression pattern and level were observed.

Naturally occurring singleton residues in AAV capsid impact vector performance and illustrate structural constraints.

Vectors based on the adeno-associated virus (AAV) are attractive and versatile vehicles for in vivo gene transfer. The virus capsid is the primary interface with the cell that defines many pharmacological, immunological and molecular properties. Determinants of these interactions are often restricted to a limited number of capsid amino acids. In this study, a portfolio of novel AAV vectors was developed after a structure-function analysis of naturally occurring AAV capsid isolates. Singletons, which are particular residues on the AAV capsid that were variable in otherwise conserved amino acid positions, were found to impact on vector's ability to be manufactured or to transduce. Data for those residues that mapped to monomer-monomer interface regions on the particle structure suggested a role in particle assembly. The change of singleton residues to the conserved amino acid resulted in the rescue of many isolates that were defective on initial isolation. This led to the development of an AAV vector portfolio that encompasses six different clades and 3 other distinct AAV niches. Evaluation of the in vivo gene transfer efficiency of this portfolio after intravenous and intramuscular administration highlighted a clade-specific tropism. These studies further the design and selection of AAV capsids for gene therapy applications.

Tailoring the AAV vector capsid for gene therapy.

A number of preclinical studies have shown the adeno-associated virus (AAV) to be an efficient vehicle for gene therapy. Clinical studies successfully demonstrated its potential for in vivo gene transfer. The complexity of host-vector interactions when progressing from small to large animal models, and eventually to humans, has impeded translation of AAV technology to the clinic. One approach to address this complexity has been to explore the biological characteristics of variations in AAV capsid structure. Initial strategies characterized the naturally occurring capsid variants from mammalian species. The structural and functional knowledge gathered on these natural AAV variants as vectors has led to the first series of second-generation vectors that aim at specifically improving certain properties by rational design of the capsid. A third exciting approach uses directed evolution to isolate vectors that are able to overcome selective pressures applied in the laboratory and thereby steer the capsid to evolve toward improved functionality.

Efeito do extrato bruto enzimático de Streptomyces Viridosporus T7A sobre a digestibilidade de matéria seca in vitro para ruminantes / Effect of the Streptomyces Viridosporus T7A crude fermentation extract on the in vitro digestibility of dry matter for ruminants / Effeito do extrato bruto enzimático de streptoniyces viridosporus T7A sobre a digestibilidade de matéria seca in vitro para ruminantes

As forragens de um modo geral possuem boa digestibilidade para os animais ruminantes, mas os resíduos das agroindústrias, tais como palhas e bagaços, têm aproveitamento limitado, devido ao alto teor em lignina. A cepa Streptomyces viridosporus T7A é capaz de produzir, em substrato lignocelulósico enzimas de interesse agroindustrial como a lignina peroxidase, xilanase, esterase e celulase. Neste trabalho, estudou-se o efeito da adição do extrato bruto enzimático de Streptomyces viridosporus T7A sobre a digestibilidade da fibra em ruminantes, pelo método de digestibilidade in vitro. O extrato foi adicionado na proporção de 0,2; 0,5; 2,0 e 5,0 por cento durante 48 horas, em conteúdo ruminal colhido de um búfalo cirurgicamente fistulado. Não houve diferença estatística com o controle na digestibilidade in vitro da matéria seca, quando o extrato bruto foi adicionado nos níveis de 0,2; 0,5; 2,0 e 5,0 por cento. No entanto, observou-se maior digestibidade no nível de 0,2 por cento.

Forages generally have good digestibilility in ruminant animals, but the use of agro-industrial wastes such as straws and bagasses is limited by their high proportion of lignin. In lignocellulosic substrate, the Streptomyces viridosporus T7A strain is capable to produce interesting enzymes as lignin peroxydase, xylanase, esterase, and cellulase. We studied the in vitro effect of the addition of the Streptomyces viridosporus T7A crude fermentation enzymatic extract on digestibility of fibers in ruminants. The extract was added to filtered ruminal fluid obtained from a surgically fistulated Asian buffalo, 0.2 percent, 0.5 percent, 2.0 percent, and 5.0 percent proportions. After 48 hours there was found no statistic difference in dry matter digestibility in vitro among control and the crude extract levels of 0.2, 0.5, 2.0, and 5.0 percent levels. Higher digestibility, however, was observed when it was added at 0.2 percent level.

Las forrajes generalmente tienen buena digestibilidad para los animales rumiantes, pero el uso de residuos agro-industriales como pajas y bagazos es limitados por su alta proporción de lignina. En substrato lignocelulósico, el Streptomyces viridosporus T7A es capaz de producir enzimas de interés industrial, como lignina peroxidase, xilanase, esterase y celulase. En este trabajo se estudió el efecto in vitro de la adición del extracto enzimático bruto de Streptomyces viridosporus T7A sobre la digestibilidad de fibras en rumiantes. El extracto se agregó a fluido rumial filtrado, obtenido de un búfalo quirúrgicamente fistulado, en proporciones de 0,2, 0,5, 2,0 y 5,0. Después de 48 horas, no se encontró ninguna diferencia estadística en la digestibilidad de la materia seca in vitro entre el control y los niveles de 0,2, 0,5, 2,0 y 5,0 del extracto bruto. Sin embargo, se observó digestibilidad más grande con el nivel fue de 0,2.

Avaliação do potencial de uso do extrato bruto da fermentação por Streptomyces Viridosporus T7 A em medicinaveterinária / Evaluation of the potential applicability of Streptomyces Viridosporus T7 A crude fermentation extract in veterinary medicine / Evaluación del potencial de uso del extracto bruto de la fermentación por Streptomyces viridosporus T7A en medicina veterinaria

Desde a sua descoberta como produtoras de antibióticos, as bactérias do gênero Streptomyces têm sido muito estudadas, em função de seu grande interesse para a indústria. A maioria das cepas de Streptomyces sintetiza substâncias antibacterianas, antifúngicas, antitumorais, antiparasitárias, herbicidas e enzimas, que têm empregos em medicina e agricultura, bem como em vários processos biotecnológicos. Neste trabalho estudou-se a aplicação do extrato bruto enzimático obtido da fermentação por Streptomyces viridosporus T7A para uso veterinário. O extrato bruto enzimático foi submetido a testes de atividade antimicrobiana e de inocuidade, em cultivo celular e em camundongos. Observou-se efeito inibidor sobre cepas patogênicas Gram positivas (Staphylococcus aureus), porém não sobre bactérias Gram negativas (Salmonella sp., Pseudomonas sp. e Escherichia coli). Em cultivo celular, o extrato mostrou ausência de toxicidade e efeito citoprotetor, e em camundongos foi inócuo, e teve influência positiva no peso final nos grupos tratados.

Since discovered as antibiotics producers, Streptomyces genus bacteria had been studied to a great extent, because their great industrial interest. Most of the Streptomyces strains synthesize antibacterial, antifungal, antineoplastic, antiparasitic, and herbicide substances, as well as enzymes, which are used in medicine, agriculture and other biotechnological processes. We studied the potential applicability of Streptomyces viridosporus T7A crude fermentation extract in veterinary medicine. The antimicrobial properties of enzymatic crude extract were tested against pathogenic bacteria strains, and its innocuity was tested both in cellular cultives and mice. It was observed inhibitory effect against pathogenic Gram positive bacteria (Staphylococcus aureus), but not against pathogenic Gram negative bacteria (Salmonella sp., Pseudomonas sp., and Escherichia coli). In cellular cultives, the extract showed citoprotector effect and absence of toxicity. In mice, it was innocuous and had positive influence on the final weight in the treated groups.

Desde que fueran descubiertas como productoras de antibióticos, las bacterias del género Streptomyces vienen siendo muy estudiadas, por tener gran interés para la industria. La mayoría de las variedades de Streptomyces sintetiza substancias antibacterianas, antifúngicas, antitumorales, antiparasitarias y herbicidas, así como enzimas que se usan en medicina, agricultura y otros procesos biotecnológicos. En este trabajo, se estudió el potencial de uso del extracto bruto de la fermentación por Streptomyces viridosporus T7A en medicina veterinaria. Las propiedades antimicrobianas del extracto bruto enzimático fueran testadas contra bacterias patogénicas, así como se testó su inocuidad tanto en cultivos celulares cuanto en ratones. Se observó efecto inhibitorio sobre bacterias patogénicas Gram positivas (Staphylococcus aureus), pero no sobre bacterias Gram negativas (Salmonella sp., Pseudomonas sp. y Escherichia coli). En cultivo celular, el extracto mostró ausencia de toxicidad y efecto citoprotector, y en ratones fue inocuo, y ha influenciado positivamente el peso final de los grupos tratados.

Noncemented acetabular revision and bone grafts.

In a retrospective study 14 acetabular components, implanted as part of a revision total hip arthroplasty, are radiographically analyzed. Major loss of bone was present in all cases. A bone augmentation technique is described in which a hemispherical porous coated cup was used without additional fixation together with morcelized bone grafts. No failure was noted and radiographic evidence of cup stability was noted in all cases.