Effects of somatic tissue cryopreservation on puma (Puma concolor L, 1771) tissue integrity and cell preservation after in vitro culture

Somatic resource banks play a crucial role in the conservation of genetic diversity, allowing for the preservation of biological samples from different populations. Puma somatic cells can be recovered from these banks and used in assisted techniques toward enhancing their multiplication and conservation. In response to the population reduction of this ecologically importance species, we aimed to evaluate the capacity of cryopreservation of somatic tissues on the maintenance of the integrity and quality of the cells recovered after culture, with the aim of establishing a somatic tissue bank that will allow for the safeguarding of a wide genetic sampling of pumas. Cryopreservation increased the thickness of the corneum layer in the tissues, and the number of perinuclear halos and empty gaps. Nevertheless, cryopreservation was able to maintain normal fibroblast patterns, even showing an increase in the percentage of collagen fibers. Cryopreservation maintained the proliferative potential of the tissues and the parameters evaluated during in vitro culture, mainly regarding the viability, proliferative activity, and apoptosis levels. Nevertheless, cells from cryopreserved tissues showed decreased metabolism and mitochondrial membrane potential when compared to cells from non-cryopreserved tissues. In summary, we demonstrated for the first time that puma somatic tissues subjected to cryopreservation are viable and maintain tissue integrity, featuring minimal changes after warming. Although viable somatic cells are obtained from these tissues, they undergo alterations in their metabolism and mitochondrial membrane potential. Improvements in the conservation conditions of somatic samples are needed to increase the quality of somatic tissue banks in this species.

Influence of freezing techniques and glycerol-based cryoprotectant combinations on the survival of testicular tissues from adult collared peccaries

The objective of the study was to evaluate the effects of different cryopreservation techniques including glycerol-based cryoprotectant combinations on the structure and viability of testicular tissues from adult collared peccaries. Tissue biopsies (3.0 mm³) from 5 different individuals were allocated to 10 different groups: fresh control; slow freezing (SF), conventional vitrification (CV), or solid-surface vitrification (SSV); each of them using three different combinations of cryoprotectants [dimethyl sulfoxide (DMSO) + ethylene glycol (EG); DMSO + Glycerol; and EG + Glycerol]. After thawing/warming, samples were evaluated for histomorphology, viability, proliferative capacity potential, and DNA integrity. Most effective preservation of testicular histomorphology was achieved using SF and CV with DMSO + EG. However, the use of glycerol-based cryoprotectant combinations increased the occurrence of tubular cell swelling, tubular cell loss and shrinkage from the basal membrane. Cell viability was comparable among cryopreservation methods and cryoprotectant combinations. Regarding cell proliferative capacity, the use of SF with EG + Glycerol and SSV with DMSO + Glycerol impaired the conservation of spermatogonia proliferative potential compared to other treatments. Moreover, CV with DMSO + EG was better than SF with EG + Glycerol for Sertoli cell proliferation potential. Regarding DNA integrity, less damage occurred when using SF with DMSO + EG while more fragmentations were observed when using CV with EG + Glycerol or DMSO + Glycerol as well as SSV with EG + Glycerol or DMSO + Glycerol. In sum, SF and CV appeared to be the most suitable methods for the cryopreservation of adult peccary testicular tissues. Additionally, the use of glycerol-based cryoprotectant combinations did not improve testicular tissues preservation with DMSO + EG being the most efficient option.

Cryopreservation of Spix's yellow-toothed cavy epididymal sperm using Tris- and coconut water-based extenders supplemented with egg yolk or Aloe vera

Addressing the establishment of biobanks for the conservation of wild hystricomorph rodents' germplasm, we verified the effects of different extenders and distinct concentrations of non-permeant cryoprotectants on the sperm parameters of Spix's yellow-toothed cavies. Nine testis-epididymis complexes were used for sperm collection by retrograde washing using Tris or a powdered coconut water extender (ACP®-116c). Spermatozoa were diluted and frozen with the same extenders supplemented with egg yolk or Aloe vera at a 10% or 20% concentration. After recovery and cryopreservation, all samples were evaluated for sperm kinetic parameters, morphology, membrane integrity, osmotic response, and sperm-binding capability using an egg yolk perivitelline membrane assay. After recovery, no differences were observed between Tris and ACP®-116c that provided 515.4 × 10⁶ sperm/mL and 561.6 × 10⁶ sperm/mL, presenting >65% motile sperm, respectively. After cryopreservation, most effective preservation of sperm kinetic parameters (68.1 ± 5.9% motile sperm) and membrane integrity (48.2 ± 7.4%) was provided by Tris extender supplemented with 10% egg yolk. However, both extenders supplemented with any concentration of egg yolk or Aloe vera presented similar preservation of osmotic response and sperm-binding ability after cryopreservation. In summary, we suggest the use of a Tris extender supplemented of 10% egg yolk for cryopreservation of Spix's yellow-toothed cavy epidydimal sperm.

Pyroligneous acid from Mimosa tenuiflora and Eucalyptus urograndis as an antimicrobial in dairy goats

AIMS

To evaluate the applicability of the Mimosa tenuiflora and Eucalyptus urograndis pyroligneous acids (PAs) as alternative antiseptics in dairy goats.

METHODS AND RESULTS

Cytotoxicity was evaluated in vitro using bacteria, as well as in vivo using goats, and the influence of PAs on the physicochemical parameters of fresh milk were examined. The cytotoxicity of PAs was evaluated in terms of morphology, cell viability and metabolic activity of goat tegumentary cells. The PA of M. tenuiflora had results similar to those of 2% iodine. For the in vitro tests, strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were used with the well technique, demonstrating inhibition halos greater than 9 mm. In the in vivo test, 15 animals were used per phase of the experiment, and the plate counting technique showed that there was antiseptic action of both extracts, with emphasis on the M. tenuiflora PA. Physicochemical analysis of the milk showed that neither PAs interfered with its physical-chemical parameters.

CONCLUSIONS

The PA of M. tenuiflora presented potential as an alternative antiseptic in dairy goats.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the use of PA as an antimicrobial agent in animals.

CONSERVAÇÃO DE TECIDOS SOMÁTICOS DE CATETOS (Pecari tajacu LINNAEUS, 1758) SUBMETIDO A DIFERENTES CONDIÇÕES DE ARMAZENAMENTO

O objetivo foi avaliar a influência da conservação [refrigeração a 5°C e vitrificação] sobre tecidos somáticos de catetos. O experimento foi dividido em duas etapas. Na primeira etapa, fragmentos foram refrigerados por 24 (R-24) e 48 h (R-48) e comparados com amostras não refrigeradas (C). Na segunda etapa, fragmentos foram refrigerados por 24 (RV-24) e 48 h (RV-48) seguidos da vitrificação, e comparados com fragmentos apenas vitrificados (V). Na primeira etapa, embora a espessura da epiderme não tenha sido afetada pela refrigeração por 48 h, a espessura da derme foi reduzida tanto no período de 24 h quanto de 48 h. Além disso, enquanto uma redução de fibroblastos dérmicos foi apenas evidenciada no grupo R-48, o aumento de halos perinucleares da epiderme foi observado em todos os grupos refrigerados. Na segunda etapa, tanto a espessura da epiderme, quanto da derme e total foram afetadas pela vitrificação após a refrigeração por 48 h. Além disso, enquanto uma redução de fibroblastos dérmicos foi apenas evidenciada no grupo RV-48, o aumento de halos perinucleares da epiderme foi observado em todos os grupos vitrificados. Assim, independente do período de armazenamento, a refrigeração afetou a qualidade dos tecidos somáticos de catetos, sendo esses efeitos acentuados quando os fragmentos foram refrigerados por 48 h e vitrificados. Portanto, sugere-se, quando necessário, o período de 24 h de refrigeração para amostras somáticas derivadas de catetos que irão ainda ser vitrificadas.

Establishment, characterization, and cryopreservation of cell lines derived from red-rumped agouti (Dasyprocta leporina Linnaeus, 1758) - A study in a wild rodent

Somatic cells can be used for rescuing wild mammals of ecological and economic importance, such as red-rumped agouti, through their application in advanced technologies. Thus, appropriate cell isolation, culture, and storage through cryopreservation can ensure the future safe use of these cells. We aimed to establish and evaluate the effects of culture time (second, fifth, and eighth passages) and cryopreservation on the morphology, viability, metabolism, proliferative activity, reactive oxygen species (ROS) levels, mitochondrial membrane potential (ΔΨm), and apoptosis on somatic cells derived from red-rumped agouti skin. Initially, we identified six dermal fibroblast lines by morphology, immunophenotyping, and karyotyping assays. In vitro culture after the second, fifth, and eighth passages, as well as the cryopreservation conditions used did not affect the metabolism or level of apoptosis. Nevertheless, cells in the fifth passage featured a reduction in proliferative activity and an increase in ROS levels when compared to second and eighth passage cells. Moreover, cryopreservation resulted in reduced ΔΨm when compared to non-cryopreserved cells. Additionally, cryopreserved cells showed a reduction in viability immediately after thawing; nevertheless, the viability of these cells was re-established after 11 days of in vitro culture and was similar to that of non-cryopreserved cells. In conclusion, we have shown that viable fibroblasts can be obtained from red-rumped agouti skin, featuring minimal changes after eight passages in in vitro culture systems. Additionally, adjustments to the cryopreservation protocol are necessary to reduce cellular oxidative stress caused by low temperatures.

Amifostine protects from the peripheral sensory neuropathy induced by oxaliplatin in mice

Sensory neuropathy is a dose-limiting side effect of oxaliplatin-based cancer treatment. This study investigated the antinociceptive effect of amifostine and its potential neuroprotective mechanisms on the oxaliplatin-related peripheral sensory neuropathy in mice. Oxaliplatin (1 mg/kg) was injected intravenously in Swiss albino male mice twice a week (total of nine injections), while amifostine (1, 5, 25, 50, and 100 mg/kg) was administered subcutaneously 30 min before oxaliplatin. Mechanical and thermal nociceptive tests were performed once a week for 49 days. Additionally, c-Fos, nitrotyrosine, and activating transcription factor 3 (ATF3) immunoexpressions were assessed in the dorsal root ganglia. In all doses, amifostine prevented the development of mechanical hyperalgesia and thermal allodynia induced by oxaliplatin (P<0.05). Amifostine at the dose of 25 mg/kg provided the best protection (P<0.05). Moreover, amifostine protected against neuronal hyperactivation, nitrosative stress, and neuronal damage in the dorsal root ganglia, detected by the reduced expression of c-Fos, nitrotyrosine, and ATF3 (P<0.05 vs the oxaliplatin-treated group). In conclusion, amifostine reduced the nociception induced by oxaliplatin in mice, suggesting the possible use of amifostine for the management of oxaliplatin-induced peripheral sensory neuropathy.

Cryopreservation of Collared Peccary (Pecari tajacu Linnaeus, 1758) Somatic Cells is Improved by Sucrose and High Concentrations of Fetal Bovine Serum

BACKGROUND

The formation of somatic cell banks is affected by, amongst other factors, the cryoprotectant solution used. The selection of an effective solution, therefore, is a primary parameter.

OBJECTIVE

We optimized the cryoprotectant used for collared peccary somatic cell cryopreservation.

MATERIALS AND METHODS

We categorized cells into different groups based on their cryopreservation and evaluated the morphology, viability, proliferative activity, metabolism, and oxidative stress. One group was cryopreserved in 10% DMSO with 10% fetal bovine serum (DMSO-10FBS), and another with 50% FBS (DMSO-50FBS). The cryopreservation of both groups included the presence of 0.2 M sucrose (DMSO-SUC-10FBS and DMSO-SUC-50FBS). Non-cryopreserved cells and cells cryopreserved with 10% DMSO (DMSO) supplemented with 0.2 M sucrose (DMSO-SUC) were used as controls.

RESULTS

There was no difference observed in morphology or viability among the groups. Proliferative activity was reduced in DMSO-10FBS when compared to controls. Although cryopreservation reduced metabolism, no difference was observed among solutions. A lower level of reactive oxygen species was observed in cells of DMSO-SUC-50FBS when compared to other cryoprotectants. Only cells of DMSO-SUC-50FBS had mitochondrial potential similar to non-cryopreserved cells.

CONCLUSION

10% DMSO supplemented with 50% FBS and 0.2 M SUC was observed to be the most efficient cryoprotectant for preserving collared peccary somatic cells.

A Comparative Approach of Cellular Reprogramming in the Rodentia Order

Cellular reprogramming mainly involves induction of reactivation of genes responsible for nuclear plasticity, a process that can be performed in vitro through production of cloned embryos by somatic cell nuclear transfer or by induction of cells into the pluripotent state through exogenous transcription factor expression. While these techniques are already well known and utilized in mice and rats, their application in other rodent species would be greatly beneficial, especially for conservation purposes. Within the diverse Rodentia order, wild species stand out as they play an important role in balancing the ecosystem by facilitating seed diversion, soil aeration, and consequently, reforestation. Many of these species are currently approaching extinction, and application of techniques, such as nuclear reprogramming, aimed at species conservation and multiplication and to produce stem cells is of interest. Thus, in this review, we aimed to present the evolution and success of nuclear reprogramming, mainly highlighting its potential application for the conservation of wild rodents.

Isolation, characterization, and cryopreservation of collared peccary skin-derived fibroblast cell lines

Background

Biobanking of cell lines is a promising tool of support for wildlife conservation. In particular, the ability to preserve fibroblast cell lines derived from collared peccaries is of significance as these wild mammals are unique to the Americas and play a large role in maintaining the ecosystem. We identified collared peccary fibroblasts by immunofluorescence and evaluated their morphology, growth and adherence capacity. Further, we monitored the viability and metabolic activity of the fibroblasts to determine the effects of passage number and cryopreservation on establishment of cell lines.

Methods

Skin biopsies were collected from the peripheral ear region from five adult animals in captivity. Initially, cells were isolated from fragments and cultured in the Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum and 2% antibiotic-antimycotic solution under a controlled atmosphere (38.5 °C, 5% CO₂). We evaluated the maintenance of primary cells for morphology, adherence capacity of explants, explants in subconfluence, cell growth and absence of contamination. Moreover, we identified the fibroblast cells by immunofluorescence. Additionally, to evaluate the influence of the number of passages (first, third and tenth passage) and cryopreservation on establishment of cell lines, fibroblasts were analysed for the viability, metabolic activity, population doubling time (PDT), levels of reactive oxygen species (ROS), and mitochondrial membrane potential (ΔΨm).

Results

All explants (20/20) adhered to the dish in 2.4 days ± 0.5 with growth around the explants in 4.6 days ± 0.7, and subconfluence was observed within 7.8 days ± 1.0. Moreover, by morphology and immunocytochemistry analyses, cells were identified as fibroblasts which presented oval nuclei, a fusiform shape and positive vimentin staining. No contamination was observed after culture without antibiotics and antifungals for 30 days. While there was no difference observed for cell viability after the passages (first vs. third: P = 0.98; first vs. tenth: P = 0.76; third vs. tenth: P = 0.85), metabolic activity was found to be reduced in the tenth passage (23.2 ± 12.1%) when compared to that in the first and third passage (100.0 ± 24.4%, P = 0.006). Moreover, the cryopreservation did not influence the viability (P = 0.11), metabolic activity (P = 0.77), or PDT (P = 0.11). Nevertheless, a greater ΔΨm (P = 0.0001) was observed for the cryopreserved cells (2.12 ± 0.14) when compared to that in the non-cryopreserved cells (1.00 ± 0.05). Additionally, the cryopreserved cells showed greater levels of intracellular ROS after thawing (1.69 ± 0.38 vs. 1.00 ± 0.22, P = 0.04).

Conclusions

This study is the first report on isolation, characterization and cryopreservation of fibroblasts from collared peccaries. We showed that adherent cultures were efficient for obtaining fibroblasts, which can be used as donor cells for nuclei for species cloning and other applications.

Cryopreservation and Culture of Testicular Tissues: An Essential Tool for Biodiversity Preservation

Systematic cryo-banking of reproductive tissues could enhance reproductive management and ensure sustainability of rare mammalian genotypes. Testicular tissues contain a vast number of germ cells, including at early stages (spermatogonia and spermatocytes), that can potentially develop into viable spermatozoa after grafting or culture in vitro, and the resulting sperm cells then can be used for assisted reproductive techniques. The objective of this review was to describe current advances, limitations, and perspectives related to the use of testicular tissue preservation as a strategy for the conservation of male fertility. Testes can be obtained from mature or prepubertal individuals, immediately postmortem or by orchiectomy, but testicular biopsies could also be an alternative to collect samples from living individuals. Testicular fragments can be then cryopreserved by using slow or ultra-rapid freezing, or even vitrification methods. The composition of cryopreservation media can vary according to species-specific characteristics, especially regarding the cryoprotectant type and concentration. Finally, spermatozoa have been usually obtained after xenografting of testicular fragments into severely immunodeficient mice, while this method still has to be optimized after in vitro culture conditions.

Embryonic/Fetal Development, Placentation and Glycosaminoglycans in the Female Reproductive Tract and Placenta

Background: Fetal attachments, placentation and embryonic development have been widely discussed in rodents such as agoutis and cavies, as well as research on glycosaminoglycans (GAGs) in rats and rabbits. Moreover, studies on buffalo, cattle and sheep are described in ruminants, and work has also been reported in sheep with GAGs in placentoma. However, further studies are needed in this regard, since there are reports of economic losses associated with reproductive failures described for cattle such as changes in the chorion and allantois, and in sheep in which changes between the transition from vitelline to allantois circulation have been discussed.  Review: In relation to embryonic development, detailed studies have been described in rodents such as rats (12 days old), desert mouse (15 days old) and agoutis at 30 days. Macroscopic structures such as the cephalic region, nose, optic vesicle, cervical curvature, thoracic and pelvic limbs were observed, as well as microscopic structures such as the pituitary, lung, heart, brain cavity, liver, retina, and ossification regions. There are reports of buffalo and cattle studies in ruminants describing early embryonic development. However, the research in the case of sheep is limited, meaning there is only the ultrasound examination, such as gestational diagnosis and morphometric measurement of the embryonic vesicle. Still, studies with umbilical funicular and placental development of sheep with different gestational ages can be highlighted. Regarding extraembryonic annexes, four important structures which contribute to embryonic maintenance have been reported. These are called the chorion, amnion, allantois and yolk sac, respectively, and are responsible for originating the placenta, embryonic protection, collecting metabolic waste and early embryonic nutrition. In addition, correlating the annexes gives rise to the placentation process, which were described two models; the first is transient, called chorioviteline, and the second is called chorioallantoid, which represents the definitive model. Allied to the gestational process, the importance of glycosaminoglycans (GAGs) and proteoglycans are worth mentioning, as they are essential components of the extracellular matrix. They are related in the implantation process, tissue organization during gestation, and also in placental angiogenesis, as described in ruminants (i.e. involved in the vascular growth that accompanies the development of the placenta), which in turn causes an increase in blood flow in this organ, and constitutes a determining factor for fetal development. Conclusion: Such studies regarding the embryonic development of ruminants are still limited to sonographic description and some information is only available in the context of extraembryonic membranes. For glycosaminoglycans, chondroitin sulfate, dermatan sulfate, heparan sulfate and hyaluronic acid are identified in the reproductive tract and placenta. We intend to produce important information for the reproductive and sanitary management of ruminants with the information in this article, providing data to stimulate new studies aiming to minimize the occurrence of embryonic death and economic losses. In addition, further studies on GAGs are needed to better understand their true correlation with gestation, so they can intercede through supplementation and minimize reproductive losses.

Production of collared peccary (Pecari tajacu Linnaeus, 1758) parthenogenic embryos following different oocyte chemical activation and in vitro maturation conditions

To optimize the protocols for assisted reproductive techniques (ARTs) in collared peccary (Pecari tajacu Linnaeus, 1758), we evaluated various conditions for oocyte in vitro maturation (IVM) and chemical activation. Initially, we assessed the IVM rates, cumulus-oocyte complex (COC) quality, and oocyte morphometry in the absence or presence of epidermal growth factor (EGF). There was no difference between the COCs matured in absence or presence of EGF for the expansion of cumulus cells (97.6% ± 1.2 vs. 100% ± 0.0), presence of first polar body (65.9% ± 1.2 vs. 70.5% ± 1.8), nuclear status in second metaphase (62.5% ± 11.6 vs. 68.4% ± 4.9), cytoplasmic maturation (100.0% ± 0.7 vs. 75.0% ± 0.7), reactive oxygen species levels (0.5 ± 0.2 vs. 0.3 ± 0.1), and mitochondrial membrane potential (1.1 ± 0.2 vs. 1.1 ± 0.1). However, the zona pellucida thickness of matured COCs was reduced in the presence of EGF. Thus, the EGF group was used for further experiments. The oocytes were artificially activated with ionomycin and four secondary activator combinations [6-dimethylaminopurine (6D), 6D and cytochalasin B (6D + CB), cycloheximide (CHX), and CHX and CB (CHX + CB)]. The effect of immature COCs based on cumulus cell layers and cytoplasm homogeneity (GI and GII or GIII COCs) on embryonic development and quality was evaluated. There was no difference in the cleavage rates among the groups of secondary activators. The cleavage rates of embryos derived from GI/GII and GIII COCs were greater than 72.2% and 25.0%, respectively. Moreover, treatment with CHX showed a reduction in the cleavage rate of embryos derived from GIII COCs when compared to the cleavage rate of embryos derived from GI/GII COCs (P < 0.05). Nevertheless, higher rates of blastocyst/total GI and GII COCs were observed in the 6D group (27.6% ± 0.3) compared to CHX group (6.9% ± 0.3). Additionally, only 6D treatment resulted in the production of embryos derived from GIII COCs (25.0% ± 0.2). The percentage of the ICM/total cell ratio was also greater in blastocysts derived from 6D (42.5% ± 19.0), 6D + CB (37.9% ± 21.9), and CHX + CB (43.8% ± 19.6) groups when compared to CHX (3.6% ± 0.1) group. Thus, the combination of ionomycin and 6D could produce collared peccary embryos by activation of both GI/GII COCs and GIII COCs. These optimized IVM conditions using EGF and chemical activation using ionomycin and 6D in collared peccaries form the first steps for establishing ARTs to conserve this species.

INFLUÊNCIA DO CORPO LÚTEO SOBRE A RECUPERAÇÃO DE OÓCITOS IMATUROS BOVINOS DERIVADOS DE FÊMEAS POST-MORTEM

O objetivo do presente trabalho foi avaliar a influência do corpo lúteo (CL), glândula endócrina temporária presente nos ovários, sobre a recuperação de oócitos imaturos bovinos derivados de ovários de fêmeas post-mortem. Para tanto, as seguintes comparações foram realizadas: fêmeas não prenhes com CL vs. fêmeas não prenhes sem CL; fêmeas prenhes com CL vs. fêmeas não prenhes com CL; e ovário com CL vs. ovário sem CL. Assim, ovários foram obtidos em abatedouro e os oócitos recuperados por aspiração folicular. A qualidade oocitária foi avaliada por morfologia convencional e ensaio de azul cresil brilhante (ACB), sendo quantificados oócitos viáveis e não viáveis para cada técnica. Todos os dados foram analisados pelo teste de Fisher (P<0,05). Assim, avaliando fêmeas ou ovários com ou sem CL, nenhuma diferença foi observada nos parâmetros avaliados. Contudo, um maior percentual de oócitos viáveis por morfologia foi obtido de fêmeas prenhes com CL, quando comparado às fêmeas não prenhes com CL. Em conclusão, pode-se afirmar que parâmetros de recuperação e qualidade oocitária não são afetados pela presença de CL, exceto em doadoras prenhes que apresentaram oócitos de melhor qualidade.

PLGA Implants containing vancomycin and dexamethasone: development, characterization and bactericidal effects

Post-operative endophthalmitis is an infection and an inflammation of the eye following a surgical procedure. Its treatment is based on drug injections into the eye. However, this treatment can lead to ocular complications. Intraocular implants could substitute the conventional therapy. Poly(lactic-co-glycolic acid) (PLGA) implants comprising on vancomycin and dexamethasone were evaluated as drug delivery system to treat endophthalmitis after cataract surgery. Implants were characterized by drug content uniformity, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Wide Angle X-ray Scattering (WAXS), Scanning Electron Microscopy (SEM) and in vitro drug release. The bactericidal effect of vancomycin, eluted from the implants, was demonstrated against Staphylococcus aureus and Staphylococcus epidermidis. The drugs were uniformly distributed in the polymer. The analytical techniques revealed the chemical integrity of the drugs incorporated into the polymer and the modification of dexamethasone semi-crystalline nature. Drugs were controlled released from implants; and the eluted vancomycin showed bactericidal effects. In conclusion, PLGA implants containing vancomycin and dexamethasone may represent a therapeutic alternative to treat post-operative endophthalmitis.

Predicting cortical bone adaptation to axial loading in the mouse tibia

The development of predictive mathematical models can contribute to a deeper understanding of the specific stages of bone mechanobiology and the process by which bone adapts to mechanical forces. The objective of this work was to predict, with spatial accuracy, cortical bone adaptation to mechanical load, in order to better understand the mechanical cues that might be driving adaptation. The axial tibial loading model was used to trigger cortical bone adaptation in C57BL/6 mice and provide relevant biological and biomechanical information. A method for mapping cortical thickness in the mouse tibia diaphysis was developed, allowing for a thorough spatial description of where bone adaptation occurs. Poroelastic finite-element (FE) models were used to determine the structural response of the tibia upon axial loading and interstitial fluid velocity as the mechanical stimulus. FE models were coupled with mechanobiological governing equations, which accounted for non-static loads and assumed that bone responds instantly to local mechanical cues in an on–off manner. The presented formulation was able to simulate the areas of adaptation and accurately reproduce the distributions of cortical thickening observed in the experimental data with a statistically significant positive correlation (Kendall's τ rank coefficient τ = 0.51, p < 0.001). This work demonstrates that computational models can spatially predict cortical bone mechanoadaptation to a time variant stimulus. Such models could be used in the design of more efficient loading protocols and drug therapies that target the relevant physiological mechanisms.

Goat oocyte production by standard or one-shot FSH treatments and quantitative analysis of transcripts for EGF ligands and its receptor after in vitro maturation

Hormonal ovarian stimulation may affect the success of embryo production by regulating transcripts in recovered cumulus-oocyte complexes (COCs). Here, in parallel to morphological classification and in vitro maturation (IVM) rate analysis, we investigated the expression of epidermal growth factor (EGF) and its receptor (EGFR) in oocytes and cumulus cells from goat COCs recovered by laparoscopy after standard [multi-dose follicle-stimulating hormone (FSH)] or one-shot (single dose FSH plus eCG) treatments. No differences were observed among the number of recovered and morphologically graded COCs or the IVM rates for both gonadotropic treatments. However, the standard protocol produced COCs with higher EGFR expression in the cumulus cells than the one-shot treatment. Additionally, EGF mRNA levels were less than EGFR mRNA levels, and they did not differ among COCs from both treatments. However, during maturation, the EGF transcripts increased in oocytes derived only from the standard protocol. Interestingly, IVM strikingly increased EGFR expression in oocytes and cumulus cells but not in oocytes that fail in first polar body extrusion, irrespective of hormonal treatment. These results appear to be related to the resumption of meiosis and suggest that EGF may act through the cumulus cells or directly on the oocyte receptor.

Platelet-Activating Factor (PAF) Modulates Peritoneal Mouse Macrophage Infection by Leishmania amazonensis

The effects of platelet-activating factor (PAF) on the infection of peritoneal mouse macrophages by Leishmania amazonensis were investigated. Prior to the infection, the parasites and/or the macrophages were treated with PAF and/or one of the following modulators: WEB 2086 (PAF antagonist), and the modulators of protein kinase C, phorbol-12-myristate-13-acetate (PMA), and sphingosine. The infection was inhibited when the macrophages or both the parasites and the macrophages were treated with PAF, but stimulated by PAF-treated parasites. WEB 2086 abrogated PAF effects in both systems. The infection was stimulated when the macrophages were treated with sphingosine plus PAF, but inhibited when the macrophages were treated with sphingosine and the parasites with sphingosine plus PAF. The infection was inhibited by sphingosine-treated parasites, either in the presence or in the absence of PAF. Leishmania amazonensis-macrophage infection was inhibited by PMA in all systems tested.