Autonomic effects induced by pharmacological activation and inhibition of Raphe Pallidus neurons in anaesthetized adult pigs

The Raphe Pallidus (RPa) is a region of the brainstem that was shown to modulate the sympathetic outflow to many tissues and organs involved in thermoregulation and energy expenditure. In rodents, the pharmacological activation of RPa neurons was shown to increase the activity of the brown adipose tissue, heart rate, and expired CO₂ , whereas their inhibition was shown to induce cutaneous vasodilation and a state of hypothermia that, when prolonged, leads to a state resembling torpor referred to as synthetic torpor. If translatable to humans, this synthetic torpor-inducing procedure would be advantageous in many clinical settings. A first step to explore such translatability, has been to verify whether the neurons within the RPa play the same role described for rodents in a larger mammal such as the pig. In the present study, we show that the physiological responses inducible by the pharmacological stimulation of RPa neurons are very similar to those observed in rodents. Injection of the GABA_A agonist GABAzine in the RPa induced an increase in heart rate (from 99 to 174 bpm), systolic (from 87 to 170 mm Hg) and diastolic (from 51 to 98 mm Hg) arterial pressure, and end-tidal CO₂ (from 49 to 62 mm Hg). All these changes were reversed by the injection in the same area of the GABA_A agonist muscimol. These results support the possibility for RPa neurons to be a key target in the research for a safe and effective procedure for the induction of synthetic torpor in humans.

Behavioral Assessment of Vision in Pigs

Swine (Sus scrofa) are often the 'gold standard' laboratory animal for ophthalmology research due to the anatomic and physiologic similarities between the porcine and human eye and retina. Despite the importance of this model, few tools for behavioral vision assessment in pigs are available. The aim of this study was to identify and validate a feasible and reproducible behavioral test to assess vision in a pig model of photoreceptor degeneration. In addition, a robust behavioral test will reduce stress and enhance enrichment by allowing animals opportunities for environmental exploration and by reducing the number of invasive experimental procedures. Two distinct behavioral approaches were tested: the obstacle-course test and temperament test. In the obstacle-course test, pigs were challenged (after an initial training period) to navigate a 10-object obstacle course; time and the number of collisions with the objects were recorded. In the temperament test, the time needed for pigs to complete 3 different tasks (human-approach, novel-object, and open-door tests) was recorded. The obstacle-course test revealed significant differences in time and number of collisions between swine with vision impairment and control animals, and the training period proved to be pivotal to avoid bias due to individual animal characteristics. In contrast, the temperament test was not altered by vision impairment but was validated to measure stress and behavioral alterations in laboratory pigs undergoing experimental procedures, thus achieving marked refinement of the study.

Thymbra capitata (L.) Cav. and Rosmarinus officinalis (L.) Essential Oils: In Vitro Effects and Toxicity on Swine Spermatozoa

Essential oils possess a variety of biological properties (i.e., antioxidant, antibacterial, and cytotoxic) that could possibly be applied in reproductive medicine, but their effects on spermatozoa are still partially unknown. The aim of the study was to describe the effects of Thymbra capitata (L.) Cav. and Rosmarinus officinalis (L.) essential oils on the main morpho-functional parameters of swine spermatozoa. Essential oils were preliminary characterized by gas chromatography and added with emulsifiers to facilitate diffusion. Experimental samples were prepared by suspending a fixed number of spermatozoa in 5 mL of medium with 10 different concentrations of essential oil (0.2–2 mg/mL, at intervals of 0.2). After 3 h of incubation, samples were analyzed for pH, viability, objective motility, and acrosome status. Results showed that the effects of the essential oils are concentration-dependent and that R. officinalis is well tolerated up to 0.6 mg/mL. T. capitata impaired the spermatozoa starting from the lowest concentration, with complete spermicidal effect from 0.4 mg/mL. The patterns of damage, confirmed by SEM, were different and quite distinct. As expected, spermatozoa proved to be sensitive to external stimuli and capable of showing different functional patterns, providing interesting insights to the action/toxicity mechanisms. The results of the present work represent the first step towards the systematic characterization of the effects of these compounds on spermatozoa. This kind of studies are necessary to strengthen the idea of future applications of essential oils in the reproductive field due to their antioxidant, antibacterial, or spermicidal properties.

Ultrasound guided spinal catheter insertion in piglet: preliminary results

OBJECTIVE

To describe the ultrasound (US) evaluation of the cervical, thoracic and lumbar spinal tracts in piglets and to evaluate the feasibility of the ultrasound guided spinal catheter placement in newborn and paediatric piglets.

STUDY DESIGN

Prospective experimental study.

ANIMALS

A total of two piglet cadavers (age, 7 and 14 days) and eight commercial crossbreed piglets divided into four groups according to age: 7 (P7), 14 (P14), 21 (P21) and 28 (P28) days.

METHODS

In the first part of the study an ultrasound examination of the spinal tract was performed in piglet cadavers applying the transverse and the longitudinal approaches in sternal and lateral recumbencies. In the second phase, the piglets were anaesthetized with sevoflurane. A US examination with a 10 MHz linear probe was performed and a spinal catheter was introduced between the spinous processes of L2 and L3 lumbar vertebrae using an in-plane technique and its advancement was monitored with the probe. At the end of procedure, the catheter was removed. The piglets recovered from anaesthesia and were monitored for one week.

RESULTS

In phase I the authors identified the paramedian longitudinal approach as the most feasible for spinal structure evaluation in piglets. In phase II, the paramedian longitudinal views enabled a good visualization of the spinal cord and of the catheter advancement up to the cisterna magna in groups P7 and P14. In groups P21 and P28 it was not possible to visualize the neuroaxial structures and the spinal catheter using the same approach. No clinical alterations were recorded during the procedure or the following days.

CONCLUSIONS AND CLINICAL RELEVANCE

US-guided spinal catheter placement appeared a feasible technique in piglets younger than 14 days but it is not useful in older piglets.

Bioavailability of Microencapsulated Iron from Fortified Bread Assessed Using Piglet Model

The aim of this study was to investigate the influence of oral iron supplementation, in the form of fortified breads, on the growth performance, health, iron status parameters, and fecal metabolome of anemic piglets. A study was conducted on 24 hybrid (Large White × Landrace × Duroc) piglets. From day 44, the post-natal 12 piglets were supplemented with 100 g of one of two experimental breads, each fortified with 21 mg of ferrous sulphate, either encapsulated or not. After one week of oral supplementation, hematological parameters (hematocrit value, hemoglobin, and red blood cells) showed statistically significant differences (p ≤ 0.05). Piglets fed with the fortified breads had higher iron concentrations in the heart, liver, and intestinal mucosa compared to anemic piglets fed with control bread. Gene expression of hepcidin, iron exporter ferroportin (IREG1), and divalent metal transporter 1 (DMT1), together with concentrations of plasma ferritin, showed no significant statistical differences between groups. Both fortified breads could be used as sources of bioavailable iron. The seven-day intervention trial showed microencapsulation to have only a mild effect on the effectiveness of iron supplementation in the form of fortified bread.

The biomedical piglet: establishing reference intervals for haematology and clinical chemistry parameters of two age groups with and without iron supplementation

Background

The similarities between swine and humans in physiological and genomic patterns, and the great correlation in size and anatomy, make pigs extremely useful in preclinical studies. New-born piglets can represent a model for congenital and genetic diseases in new-born children. It is known that piglets may have significant differences in clinicopathological results compared to adult pigs. Therefore, adult laboratory reference intervals cannot be applied to piglets. The aim of this study was to compare haematological and chemical variables in piglets of two ages and determinate age-related reference intervals for commercial hybrid young pigs.

Blood samples were collected under general anaesthesia from 130 animals divided into five- (P5) and 30- (P30) day-old piglets. Only P30 animals were treated with parenteral iron after birth. Samples were analysed using automated haematology (ADVIA 2120) and chemistry analysers, and age-related reference intervals were calculated.

Results

Significant higher values of RBC, Hb and HCT were observed in P30 animals when compared to P5, with an opposite trend for MCV. These results were associated with a reduction of the RBC regeneration process and the thrombopoietic response. The TSAT and TIBC were significantly higher in P30 compared to P5; however, piglets remained iron deficient compared to adult reference intervals reported previously.

Conclusions

In conclusion, this paper emphasises the high variability occurring in clinicopathological variables between new-born and 30-day-old pigs, and between piglets and adult pigs. This study provides valuable reference data for piglets at precise ages and could be used in the future as historical control improving the Reduction in animal experiments, as suggested by the 3Rs principle.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-017-0946-2) contains supplementary material, which is available to authorized users.

Can Microfiltered Seminal Plasma Preserve the Morphofunctional Characteristics of Porcine Spermatozoa in the Absence of Antibiotics? A Preliminary Study

Artificial insemination is extensively performed in pig farms in Europe, the United States and Canada. Antibiotics are typically added to the inseminating dose to limit bacterial growth during liquid phase storage at 16°C, as bacterial contamination is unavoidable. The World Organization for Animal Health (OIE) and the Food and Agriculture Organization (FAO) take action to control and reduce antibiotic use in animals as more bacteria are becoming resistant to antimicrobials. To avoid the use of antibiotics, we prepared inseminating doses using microfiltered seminal plasma (SP). Microfiltration is a common technology used to reduce bacterial contamination but may retain seminal substances, influencing sperm quality during storage. Therefore, the aim of this study was to evaluate the morphofunctional parameters of spermatozoa during storage at 16°C in doses prepared with or without microfiltered SP, with or without the addition of antibiotics, in a Latin square design. Artificial insemination doses with microfiltered SP and without antibiotic addition preserved spermatozoa viability, mitochondrial membrane potential, acrosome integrity and objective motility, with absolute values equal or even better than those observed in conventional doses. In conclusion, although the results could be considered preliminary due to the small sample size, this study suggests that microfiltration of SP can be a simple method, feasible on farms, to replace antibiotic use in extended doses stored in the liquid phase at 16°C for up to 7 days.

Effect of tributyltin on mammalian endothelial cell integrity

Tributyltin (TBT), is a man-made pollutants, known to accumulate along the food chain, acting as an endocrine disruptor in marine organisms, with toxic and adverse effects in many tissues including vascular system. Based on the absence of specific studies of TBT effects on endothelial cells, we aimed to evaluate the toxicity of TBT on primary culture of porcine aortic endothelial cells (pAECs), pig being an excellent model to study human cardiovascular disease. pAECs were exposed for 24h to TBT (100, 250, 500, 750 and 1000nM) showing a dose dependent decrease in cell viability through both apoptosis and necrosis. Moreover the ability of TBT (100 and 500nM) to influence endothelial gene expression was investigated at 1, 7 and 15h of treatment. Gene expression of tight junction molecules, occludin (OCLN) and tight junction protein-1 (ZO-1) was reduced while monocyte adhesion and adhesion molecules ICAM-1 and VCAM-1 (intercellular adhesion molecule-1 and vascular cell adhesion molecule-1) levels increased significantly at 1h. IL-6 and estrogen receptors 1 and 2 (ESR-1 and ESR-2) mRNAs, after a transient decrease, reached the maximum levels after 15h of exposure. Finally, we demonstrated that TBT altered endothelial functionality greatly increasing monocyte adhesion. These findings indicate that TBT deeply alters endothelial profile, disrupting their structure and interfering with their ability to interact with molecules and other cells.

Improved dual AAV vectors with reduced expression of truncated proteins are safe and effective in the retina of a mouse model of Stargardt disease

Stargardt disease (STGD1) due to mutations in the large ABCA4 gene is the most common inherited macular degeneration in humans. We have shown that dual adeno-associated viral (AAV) vectors effectively transfer ABCA4 to the retina of Abca4-/- mice. However, they express both lower levels of transgene compared with a single AAV and truncated proteins. To increase productive dual AAV concatemerization, which would overcome these limitations, we have explored the use of either various regions of homology or heterologous inverted terminal repeats (ITR). In addition, we tested the ability of various degradation signals to decrease the expression of truncated proteins. We found the highest levels of transgene expression using regions of homology based on either alkaline phosphatase or the F1 phage (AK). The use of heterologous ITR does not decrease the levels of truncated proteins relative to full-length ABCA4 and impairs AAV vector production. Conversely, the inclusion of the CL1 degradation signal results in the selective degradation of truncated proteins from the 5'-half without affecting full-length protein production. Therefore, we developed dual AAV hybrid ABCA4 vectors including homologous ITR2, the photoreceptor-specific G protein-coupled receptor kinase 1 promoter, the AK region of homology and the CL1 degradation signal. We show that upon subretinal administration these vectors are both safe in pigs and effective in Abca4-/- mice. Our data support the use of improved dual AAV vectors for gene therapy of STGD1.

Access to cerebrospinal fluid in piglets via the cisterna magna: optimization and description of the technique

The collection of cerebrospinal fluid is necessary in order to determine its composition. It can then be used to diagnose various diseases. The aim of the study was to develop and optimize a technique for performing safe centesis for the collection of cerebrospinal fluid in piglets and its injection through the cisterna magna. The study was divided into three phases: (1) anatomical study of cadavers, (2) in vivo application of the technique and (3) observation of recovery time. The proposed technique resulted in a safe puncture of the cisterna magna. The authors identified and confirmed the correspondence of the crista occipitalis and the wings of the atlas with the external landmarks on the cadaver by means of direct radiological visualization. The punctures were performed successfully at the first attempt in 11 out of 12 anaesthetized piglets. The technique herein described provides a reproducible safe and easy route for approaching the cisterna magna for cerebrospinal fluid collection, drug administration and gene delivery.

Orexin system expression in the gastrointestinal tract of pigs

The aim of the present study was to characterize the expression of both proteins and gene transcripts for orexins (OXA and OXB) and their cognate receptors (OX1R and OX2R) in the different gastrointestinal sections of pigs. Using immunohistochemistry, OXA and OXB were found to be co-expressed in the same endocrine cells localized in the basal third of the glands of the body portion of the stomach. Using double immunostaining technique, these orexin-immunoreactive (IR) cells co-stored ghrelin and gastrin. Apparently, OX1R was also expressed within the same cells, forming the tubular gastric gland which displayed positive immunostaining for orexins and the other peptides. Neurons of the enteric nervous system of the stomach were not immunolabeled. We did not find any definite OXA- or OXB-IR cells as well as any immunosignal for orexin receptors in sections of the duodenum, ileum, cecum and rectum. PPOX, OX1R, OX2R mRNA were similarly expressed in all the gastrointestinal tracts. Gastrin and ghrelin showed the highest levels of expression in the gastric mucosa, but their abundance decreased along the subsequent tracts. Thus, in pigs, orexins do not play any role in the local control of intestinal motility and secretion but may rather be involved as endocrine modulators for the regulation of feeding and metabolic homeostasis. However, the co-localization of ghrelin and gastrin with both orexins in the same endocrine cells of the gastric glands suggests that these gut peptides may collaborate in the regulation of gastric secretion, energy homeostasis, body weight and food intake.

AAV-mediated photoreceptor transduction of the pig cone-enriched retina

Recent success in clinical trials supports the use of adeno-associated viral (AAV) vectors for gene therapy of retinal diseases caused by defects in the retinal pigment epithelium (RPE). In contrast, evidence of the efficacy of AAV-mediated gene transfer to retinal photoreceptors, the major site of inherited retinal diseases, is less robust. In addition, although AAV-mediated RPE transduction appears efficient, independently of the serotype used and species treated, AAV-mediated photoreceptor gene transfer has not been systematically investigated thus so far in large animal models, which also may allow identifying relevant species-specific differences in AAV-mediated retinal transduction. In the present study, we used the porcine retina, which has a high cone/rod ratio. This feature allows to properly evaluate both cone and rod photoreceptors transduction and compare the transduction characteristics of AAV2/5 and 2/8, the two most efficient AAV vector serotypes for photoreceptor targeting. Here we show that AAV2/5 and 2/8 transduces both RPE and photoreceptors. AAV2/8 infects and transduces photoreceptor more efficiently than AAV2/5, similarly to what we have observed in the murine retina. The use of the photoreceptor-specific rhodopsin promoter restricts transgene expression to porcine rods and cones, and results in photoreceptor transduction levels similar to those obtained with the ubiquitous promoters tested. Finally, immunological, toxicological and biodistribution studies support the safety of AAV subretinal administration to the large porcine retina. The data presented here on AAV-mediated transduction of the cone-enriched porcine retina may affect the development of gene-based therapies for rare and common severe photoreceptor diseases.

In vitro production of multigene transgenic blastocysts via sperm-mediated gene transfer allows rapid screening of constructs to be used in xenotransplantation experiments

Multigene transgenic pigs would be of benefit for large animal models and in particular for xenotransplantation, where extensive genetic manipulation of donor pigs is required to make them suitable for organ grafting to humans. We have previously produced multitransgenic pigs via sperm-mediated gene transfer (SMGT) using integrative constructs expressing 3 different reporter genes. The aim of the present work was to evaluate the efficacy and safety of using 3 integrative constructs carrying 3 different human genes involved in the modulation of inflammatory responses. We developed an in vitro fertilization system to demonstrate that SMGT can be used to efficiently produce multigene transgenic embryos through a 1-step genetic modification using multiple integrative constructs each carrying a different human gene involved in the modulation of inflammatory processes (hHO1, hCD39, and hCD73). The results suggest that this system allowed an effective preliminary test of transgenesis optimization, greatly reducing the number of animals used in the experiments and fulfilling important ethical issues. We performed 5 in vitro fertilization experiments using sperm cells preincubated with all 3 integrative constructs. A total of 1,498 oocytes were fertilized to obtain 775 embryos, among which 340 further developed into blastocysts. We did not observe any toxicity related to the transgenesis procedure that affected normal embryo development. We observed 68.5% transgenesis efficiency. Blastocysts were 48% single, 31% double, and 21% triple transgenic.

Induced metastable memory in heat shock response

We studied the dynamics of the Heat Shock Response (HSR) mechanism, and the persistence of a injury-protected state in the cell following the shocks, known as thermotolerance. A series of double shock experiments were performed on Chinese Hamster Ovary (CHO) cells, tracking the dynamics of some components of HSR pathway (the Hsp70 protein level and Hsp70 mRNA transcription rate). The main features of HSR dynamics were well reproduced by a simplified model of the chemical reaction pathways governing the HSR. In particular, the thermotolerance phenomenon could be well characterized by introducing a shock-dependent switch in mRNA halflife, that can be interpreted as a sort of primitive memory at the mRNA level.

Use of combined conventional and real-time PCR to determine the epidemiology of feline haemoplasma infections in northern Italy

Although knowledge of feline haemotropic mycoplasmas (haemoplasmas) has dramatically improved in recent years, some issues still remain to be elucidated. The aim of the current study was to evaluate the prevalence of feline haemoplasma infections in blood samples collected from cats in northern Italy. A convenience-sample of 307 cats (40 anaemic; 258 non-anaemic; nine with unknown haematocrit [HCT]) was investigated using polymerase chain reaction assays. Furthermore, the date of blood collection, signalment and clinicopathological data were retrospectively evaluated to assess predictors and risk factors for infection. Haemoplasma infections were highly prevalent in the sample investigated with an overall prevalence of 18.9% (95% confidence interval: 14.5-23.3%). The prevalence for the three feline haemoplasmas was 17.3% for 'Candidatus Mycoplasma haemominutum' (CMhm), 5.9% for Mycoplasma haemofelis (Mhf) and 1.3% for 'Candidatus Mycoplasma turicensis' (CMt). Feline immunodeficiency virus-positive status represented a risk factor for infection with an odds ratio of 4.19 (P=0.02). Moreover, a higher prevalence was observed in summer (odds ratio 1.78; P=0.04) which may be consistent with arthropod-borne disease transmission. Cats infected with Mhf showed significantly lower HCT (P=0.03), haemoglobin values (P=0.02) and red blood cell counts (P=0.04), lower mean corpuscular haemoglobin concentration (P<0.01) and higher white blood cell counts (P<0.01) when compared with non-infected cats.

A brief overview of transgenic farm animals

Transgenesis offers new possibilities to rapidly modify the genome of living organisms. The application of transgenesis to farm animals faces many problems, more than those observed in the transgenesis of laboratory animals, as there are currently many different techniques available to obtain transgenic animals, which all have problems regarding low efficiency and high costs. When these techniques are applied to farm animals the problems concerning transgenesis are multiplied. Two main techniques, male pronuclear microinjection and sperm mediated gene transfer, utilised in farm animal transgenesis, are briefly presented. The improvement of these techniques and the employment of other biotechnologies such as cloning, could expand the uses of transgenic farm animals for human health.

Prostaglandin F2-alpha receptor (FPr) expression on porcine corpus luteum microvascular endothelial cells (pCL-MVECs)

BACKGROUND

The corpus luteum (CL) is a transient endocrine gland and prostaglandin F2-alpha is considered to be the principal luteolysin in pigs. In this species, the in vivo administration of prostaglandin F2-alpha induces apoptosis in large vessels as early as 6 hours after administration. The presence of the prostaglandin F2-alpha receptor (FPr) on the microvascular endothelial cells (pCL-MVECs) of the porcine corpus luteum has not yet been defined. The aim of the study was to assess FPr expression in pCL-MVECs in the early and mid-luteal phases (EL-p, ML-p), and during pregnancy (P-p). Moreover, the effectiveness of prostaglandin F2-alpha treatment in inducing pCL-MVEC apoptosis was tested.

METHODS

Porcine CLs were collected in the EL and ML phases and during P-p. All CLs from each animal were minced together and the homogenates underwent enzymatic digestion. The pCL-MVECs were then positively selected by an immunomagnetic separation protocol using Dynabeads coated with anti-CD31 monoclonal antibody and seeded in flasks in the presence of EGM 2-MV (Microvascular Endothelial Cell Medium-2). After 4 days of culture, the cells underwent additional immunomagnetic selection and were seeded in flasks until the confluent stage.PCR Real time, western blot and immunodetection assays were utilized to assess the presence of FPr on pCL-MVEC primary cultures. Furthermore, the influence of culture time (freshly isolated, cultured overnight and at confluence) and hormonal treatment (P4 and E2) on FPr expression in pCL-MVECs was also investigated. Apoptosis was detected by TUNEL assay of pCL-MVECs exposed to prostaglandin F2-alpha.

RESULTS

We obtained primary cultures of pCL-MVECs from all animals. FPr mRNA and protein levels showed the highest value (ANOVA) in CL-MVECs derived from the early-luteal phase. Moreover, freshly isolated MVECs showed a higher FPr mRNA value than those cultured overnight and confluent cells (ANOVA). prostaglandin F2-alpha treatment failed to induce an apoptotic response in all the pCL-MVEC cultures.

CONCLUSION

Our data showing the presence of FPr on MVECs and the inability of prostaglandin F2-alpha to evoke an in vitro apoptotic response suggest that other molecules or mechanisms must be considered in order to explain the in vivo direct pro-apoptotic effect of prostaglandin F2-alpha at the endothelial level.

Carbon monoxide pretreatment prevents respiratory derangement and ameliorates hyperacute endotoxic shock in pigs

Endotoxic shock, one of the most prominent causes of mortality in intensive care units, is characterized by pulmonary hypertension, systemic hypotension, heart failure, widespread endothelial activation/injury, and clotting culminating in disseminated intravascular coagulation and multi-organ system failure. In the last few years, studies in rodents have shown that administration of low concentrations of carbon monoxide (CO) exerts potent therapeutic effects in a variety of diseases/disorders. In this study, we have administered CO (one our pretreatment at 250 ppm) in a clinically relevant, well-characterized model of LPS-induced acute lung injury in pigs. Pretreatment only with inhaled CO significantly ameliorated several of the acute pathological changes induced by endotoxic shock. In terms of lung physiology, CO pretreatment corrected the LPS-induced changes in resistance and compliance and improved the derangement in pulmonary gas exchange. In terms of coagulation and inflammation, CO reduced the development of disseminated intravascular coagulation and completely suppressed serum levels of the proinflammatory IL-1beta in response to LPS, while augmenting the anti-inflammatory cytokine IL-10. Moreover, the effects of CO blunted the deterioration of kidney and liver function, suggesting a beneficial effect in terms of end organ damage associated with endotoxic shock. Lastly, CO pretreatment prevents LPS-induced ICAM expression on lung endothelium and inhibits leukocyte marginalization on lung parenchyma.

Loss of ecto-5'nucleotidase from porcine endothelial cells after exposure to human blood: Implications for xenotransplantation

The endothelial cell surface expression of ecto-5'-nucleotidase (E5'N, CD73) is thought to be essential for the extracellular formation of cytoprotective, anti-thrombotic and immunosuppressive adenosine. Decreased E5'N activity may play a role in xenograft acute vascular rejection, preventing accommodation and tolerance mechanisms. We investigated the extent of changes in E5'N activity and other enzymes of purine metabolism in porcine hearts or endothelial cells when exposed to human blood or plasma and studied the role of humoral immunity in this context. Pig hearts, wild type (WT, n = 6) and transgenic (T, n = 5) for human decay accelerating factor (hDAF), were perfused ex vivo with fresh human blood for 4 h. Pig aortic endothelial cells (PAEC) were exposed for 3 h to autologous porcine plasma (PP), normal (NHP) or heat inactivated human plasma (HHP), with and without C1-inhibitor. Enzyme activities were measured in heart or endothelial cell homogenates with an HPLC based procedure. The baseline activity of E5'N in WT and T porcine hearts were 6.60 +/- 0.33 nmol/min/mg protein and 8.54 +/- 2.10 nmol/min/mg protein respectively (P < 0.01). Ex vivo perfusion of pig hearts with fresh human blood for 4 h resulted in a decrease in E5'N activity to 4.01 +/- 0.32 and 4.52 +/- 0.52 nmol/min/mg protein (P < 0.001) in WT and T hearts respectively, despite attenuation of hyperacute rejection in transgenic pigs. The initial PAEC activity of E5'N was 9.10 +/- 1.40 nmol/min/mg protein. Activity decreased to 6.76 +/- 0.57 and 4.58 +/- 0.47 nmol/min/mg protein (P < 0.01) after 3 h exposure of HHP and NHP respectively (P < 0.05), whereas it remained unchanged at 9.62 +/- 0.88 nmol/min/mg protein when incubated with PP controls. C1-inhibitor partially preserved E5'N activity, similar to the effect of HHP. Adenosine deaminase, adenosine kinase and AMP deaminase (other enzymes of purine metabolism) showed a downward trend in activity, but none were statistically significant. We demonstrate a specific decrease in E5'N activity in pig hearts following exposure to human blood which impairs adenosine production resulting in a loss of a cytoprotective phenotype, contributing to xenograft rejection. This effect is triggered by human humoral immune responses, and complement contributes but does not fully mediate E5'N depletion.

Laparoscopic insemination technique with low numbers of spermatozoa in superovulated prepuberal gilts for biotechnological application

New biotechnologies, such as sperm-mediated gene transfer (SMGT), spermatozoa freezing and spermatozoa sorting have improved the possibilities to produce animals with desirable features. The main problem associated with these technologies is the scarce availability of spermatozoa for insemination. The objective of this study was to develop a laparoscopic insemination (LI) technique in gilt that allows the use of low semen doses resulting in high fertilization rates (FR) and minimal distress to the animal; the efficiency of this technique was compared to conventional artificial insemination (AI). Ten gilts were inseminated 36 h post hCG treatment near both utero-tubal junctions (UTJ) with 1.5 x 10(9)spermatozoa/5 mL per horn and 10 gilts (C) underwent conventional AI. Embryos were collected either at two to four cell stage (LI, n = 5; C, n = 5) for determination of fertilization rate or at day 6 for evaluation of developmental competence (LI, n = 5; C, n = 5). LI gilts showed a slightly higher FR than control animals. In a second trial, 24 gilts underwent LI with varying doses (1.5 x 10(8), 1.5 x 10(7), 1 x 10(7), 5 x 10(6) or 1 x 10(6)) of semen. Two to four stage embryos were collected and FR was evaluated in each tube. FR obtained with the lowest dose was significantly different from that with other dosages (P < 0.05). Embryos were cultured in vitro to blastocyst stages (percentage of blastocysts: 79.2 +/- 3.6%). In a third trial, five gilts were inseminated with semen processed by SMGT technique; both FR (86.1 +/- 9.9%) and transgene protein expression were satisfactory. In conclusion, this study shows that LI can be a useful tool for reducing doses of insemination, without affecting the efficiency of fertilization; this technique could have a wide range of biotechnological applications.

Vascular endothelial growth factor production in growing pig antral follicles

Angiogenesis is the process that drives blood vessel development in growing tissues in response to the local production of angiogenic factors. With the present research the authors have studied vascular endothelial growth factor (VEGF) production in ovarian follicles as a potential mechanism of ovarian activity regulation. Prepubertal gilts were treated with 1250 IU equine chorionic gonadotropin (eCG) followed 60 h later by 750 IU of human chorionic gonadotropin (hCG) in order to induce follicle growth and ovulation. Ovaries were collected at different times of the treatment and single follicles were isolated and classified according to their diameter as small (<4 mm), medium (4-5 mm), or large (>5 mm). VEGF levels were measured in follicular fluid by enzyme immunoassay, and VEGF mRNA content was evaluated in isolated theca and granulosa compartments. Equine chorionic gonadotropin stimulated a prompt follicular growth and induced a parallel evident rise in VEGF levels in follicular fluid of medium and large follicles. Analysis of VEGF mRNA levels confirmed the stimulatory effect of eCG, showing that it is confined to granulosa cells, whereas theca cells maintained their VEGF steady state mRNA. Administration of hCG 60 h after eCG caused a dramatic drop in follicular fluid VEGF that reached undetectable levels in 36 h. A parallel reduction in VEGF mRNA expression was recorded in granulosa cells. The stimulating effect of eCG was also confirmed by in vitro experiments, provided that follicles in toto were used, whereas isolated follicle cells did not respond to this hormonal stimulation. Consistent with the observation in vivo, granulosa cells in culture reacted to hCG with a clear block of VEGF production. These results demonstrate that while follicles of untreated animals produce stable and low levels of the angiogenic factor, VEGF markedly rose in medium and large follicles after eCG administration. The increasing levels, essentially attributable to granulosa cells, are likely to be involved in blood vessel development in the wall of growing follicles, and may play a local key role in gonadotropin-induced follicle development. When ovulation approaches, under the effect of hCG, the production of VEGF is switched off, probably creating the safest conditions for the rupture of the follicle wall while theca cells maintained unaltered angiogenic activity, which is probably required for corpus luteum development.

In situ detection of apoptosis in regressing corpus luteum of pregnant sow: evidence of an early presence of DNA fragmentation

Luteolysis has been shown to be correlated with apoptosis in rats, sheep, and cows. In pigs, apoptosis has already been demonstrated as regards atretic follicles. The present study has been conducted to evaluate whether apoptosis occurs during corpora lutea regression in the pregnant pig and to investigate the temporal relationship between apoptosis and functional luteolysis. The apoptotic process has been studied through the research of oligonucleosome fragmentation by means of classical electrophoresis methods and by in situ detection on histological luteal sections. The latter method allows the identification of apoptosis and the localization of apoptotic cells. Pregnant sows were cloprostenol (PGF2 alpha analog) treated and ovariectomized 0, 6, 12, 24, 48, and 72 hr after treatment. Corpora lutea were utilized for progesterone and DNA extraction and in situ evaluation of apoptosis. Clear evidence of apoptosis was seen earlier with the in situ technique (6 hr for stromal tissue, 12 hr for luteal cells) than with the classical method (24 hr). Apoptosis was, however, apparent after plasma and tissue progesterone had reached basal levels. In conclusion, these results are consistent with the hypothesis that apoptosis occurs during luteolysis in pigs. Moreover, the data obtained with the in situ technique made it possible to identify signs of structural regression in stromal tissue first than in parenchymal cells. A two-stage activation of apoptosis has been discussed to explain structural changes that occur during luteolysis after cloprostenol treatment in swine corpora lutea.

Changes in maturation-promoting activity in the cytoplasm of pig oocytes throughout maturation

Maturation-promoting factor (MPF) was examined in maturing pig oocytes by electrofusing them with germinal vesicle (GV) oocytes. Oocytes containing high levels of MPF (MI or MII stages) induced the breakdown of the GV introduced by fusion and the formation of the metaphase plate in 1 hr. A similar effect was seen when two or three GV oocytes were fused with a MII oocyte and then incubated for 1 hr in the presence of cycloheximide (a specific protein synthesis inhibitor), indicating that high levels of preformed MPF are present at the metaphase stage. During the maturation in vitro of cumulus-enclosed oocytes, a first sharp rise in MPF was seen between 26 and 29 hr of culture (MI stage); MPF declined after 2 hr (AI-TI stages) and again reached high levels at 35 hr, where it remained for the rest of maturation. Denuded oocytes showed a similar behavior, but MPF appeared 9 hr earlier and the rise, due to the asynchronous maturation of these oocytes, was not as sharp as in cumulus enclosed oocytes. Cycloheximide was used to study protein synthesis requirements for oocyte maturation. Intact GV were observed after 44 hr of culture when cycloheximide was added at 26 hr or earlier, and chromosome decondensation and pronuclear formation were observed when the drug was added at 32 hr. Transcriptional requirements were investigated by treating the oocytes with alpha-amanitin, an RNA polymerase inhibitor. This drug could completely inhibit the maturation of cumulus-enclosed oocytes, but this was a somatic cell-mediated effect since denuded oocytes were insensitive to this treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of LH and FSH on the maturation of pig oocytes in vitro

This research was designed to investigate the effects of LH and FSH (50 ng/ml) on pig oocyte maturation in vitro. The following parameters were studied: a) the degree of heterologous coupling between cumulus cells and oocytes, evaluated by measuring the 3H-uridine and 3H-choline uptake in cumulus enclosed oocytes; b) meiotic maturation; c) cytoplasmatic maturation, evaluated by analyzing the ability of the oocytes to promote male pronucleus formation after in vitro fertilization. Despite the marked cumuli expansion induced by gonadotropins, uridine uptake was not influenced by LH or FSH. By contrast, choline uptake in LH-treated oocytes was significantly higher than in FSH-treated or control oocytes (3199 cpm+/-251 vs 1686 cpm+/-142, P<0.01). Gonadotropins accelerated meiotic progression, and after 30 hours of culture the percentage of oocytes at the germinal vesicle stage was significantly lower (P<0.01) in LH-(24%, 24/102) and FSH-(20%, 18/90) treated oocytes than in control oocytes (76%, 64/84). After 44 hours of culture, the percentage of oocytes reaching the MII stage was significantly higher (P<0.01) in the presence of LH (76%, 92/120) and FSH (86%, 92/108) than in the controls (35%, 40/116). The percentage of oocytes capable of sustaining male pronucleus formation was similar in the control (48.4%, 63/132) and FSH-treated oocytes (44.3%, 51/116), while it was markedly increased (P<0.01) by the addition of LH (72.7%, 143/197). The data reported indicate that in vitro pig oocytes tend to undergo meiotic maturation even in the absence of hormones. However, in our in vitro system, LH and FSH accelerated and facilitated meiotic progression, and LH selectively improved cytoplasmic maturation which is required to promote the formation of a male pronucleus.

Maturation of pig oocytes: observations on membrane potential

The membrane-potential changes of pig oocytes during maturation are described. Cumulus-enclosed oocytes have a resting potential of -41.81 +/- 0.60 mV; the removal of cumulus cells caused this potential to drop to -30.95 +/- 0.43 mV. Adding LH to the culture medium did not influence the potential of denuded oocytes but depolarized the potential of cumulus-enclosed oocytes to -32.90 +/- 0.43 mV. FSH did not affect the membrane potential of denuded or cumulus-enclosed oocytes, but significantly reduced the amplitude of the depolarization induced by LH. The effect of gonadotropins on cultured granulosa cells was also investigated. Plated granulosa cells have a resting potential of -45.21 +/- 0.72 mV, similar to that of cumulus-enclosed oocytes. As recorded in cumulus-enclosed oocytes, LH depolarized granulosa cell membrane potential (-30.33 +/- 0.69 mV) and FSH reduced this effect. To evaluate if oocyte maturation in vivo is accompanied by membrane-potential depolarization, follicular growth and oocyte maturation were induced in 6 prepubertal gilts by using an eCG-hCG treatment. Twenty hours after the beginning of oocyte maturation in vivo (induced by hCG), the membrane potential of the oocyte was depolarized to -28.84 +/- 1.01 mV, a value similar to that observed in vitro. These data indicate that both LH and FSH can influence the membrane potential of follicular somatic cells and, consequently, that of the oocyte. The electrical coupling between somatic cell and oocyte may represent a means by which the gonadotropin message is passed to the germinal cell by the somatic compartment.

Developmental competence of pig oocytes matured and fertilized in vitro

Pig follicles 3 to 6 mm in diameter were everted and matured for 44 h. The oocytes were then collected and exposed to capacitated boar sperm purified by centrifugation in a two step (65 and 70%) Percoll gradient. Of 110 ova fixed 14 h after in vitro fertilization, 78% were penetrated and 47% were monospermic. Next, 681 oocytes were cultured in vitro for 44 h after in vitro fertilization and the 266 embryos which had reached the two- to four-cell stage were transferred into the oviducts of 12 synchronized recipient gilts. Four days later, 211 embryos (79%) were recovered by uterine flushing. 40.7% of these were at the blastocyst stage, and 20% were at the morula stage. In a final experiment, four out of eight gilts which had received 40 to 50 two- to four-cell embryos, were diagnosed pregnant 30 and 37 d after in vitro fertilization. One sow farrowed nine live piglets and one stillborn, two pregnancies were in progress, while one sow returned to estrus 47 d after in vitro fertilization. These results demonstrate that pig oocytes matured and fertilized in vitro can develop to the blastocyst stage and establish a normal pregnancy resulting in the birth of live piglets.

Follicular factors influence oocyte fertilizability by modulating the intercellular cooperation between cumulus cells and oocyte

In order to investigate whether the follicular tissue influences cumulus-oocyte interaction and, consequently, the fertilizability of the egg, four experiments were carried out. In the first, cumulus-enclosed pig oocytes were cultured for 44 h in control medium (modified TCM-199) or in follicle-conditioned medium, and the intercellular coupling was studied by measuring 3H-uridine uptake. In control medium the intercellular cooperation started to decline immediately, and at 24-32 h the uncoupling was almost complete. By contrast, in follicle, conditioned medium, it remained at high levels until 24-32 h. In the second experiment protein synthesis patterns of oocytes were studied. Oocytes cultured in conditioned medium were characterized by a 45-kD protein band, while those maturing in control medium were identifiable by a marked 56-kD band. In the third experiment mature oocytes were fertilized in vitro. The percentage of penetrated egg was higher in oocytes matured in conditioned medium than in control medium. In addition, only oocytes matured in conditioned medium could consistently decondense spermatozoa and form male pronuclei. Metabolic cooperation, protein synthesis patterns, and fertilizability were also studied in oocytes matured in control medium supplemented with either 17 beta-estradiol or progesterone or testosterone or dihydrotestosterone or androstenedione or ether extract of conditioned medium. Only ether extract and progesterone stimulated cumulus oocyte interaction and sperm decondensation. In the last experiment oocytes denuded at different stage of their maturation in conditioned medium were fertilized in vitro. The longer the eggs were cultured with the cumulus, the higher was their penetrability. Moreover, only oocytes denuded after 40 h of culture could, once fertilized, promote the formation of male pronuclei. These data demonstrate that follicular secretions are fundamental for the maintenance in vitro of a functional intercellular coupling between cumulus and oocyte, which is necessary for the egg to become penetrable by spermatozoa and to acquire the conditions required for the formation of male pronuclei.

Fertility and nuptiality changes in Spain from the late 18th to the early 20th century

Abstract 3.1. A regional approach often reveals features of population trends not evident in national data. We have already pointed out that the 1768 census followed the ecclesiastical sub-divisions of the country; therefore its territorial data are not comparable with those derived from later enumerations. The 1787 and 1797 censuses, on the other hand, were based on civil sub-divisions, which can be compared, when aggregated, with later censuses of the modern statistical era.