A DFT study on magnetic interfaces based on half-metallic Co2FeGe1/2Ga1/2 with h-BN and MoSe2 monolayers.

A large variety of recently predicted and synthesized 2D materials significantly broaden the capabilities of magnetic interface design for spintronic applications. Their diverse structural and electronic properties allow fine adjustment of interfacial interactions between the electrode and spacer materials providing robust and effective spin transport. Based on recent experimental results, here we present a theoretical study of novel interfaces formed by a half-metallic Co2FeGe1/2Ga1/2 (CFGG) substrate with h-BN or MoSe2 monolayer on its top. By means of the DFT approach, the structural, magnetic and electronic properties are studied for the Co- and FeGeGa termination of the CFGG surface. The observed large spin polarization in the vicinity of the interface and robust magnetization exhibit the potential of 2D materials/CFGG heterostructures for spintronic applications.

The human lung during the embryonic period: vasculogenesis and primitive erythroblasts circulation.

Vascularization and blood cell circulation are crucial steps during lung development. However, how blood vessels are generated and when lung circulation is initiated is still a matter of debate. A morpho-functional analysis of pulmonary vasculature was done using human lung samples between 31 and 56 days post-fertilization (pf). The immunolocalization and expression of CD31, CD34, FLT-1, KDR and the vascular growth factor (VEGF) were investigated. The results showed that at day 31 pf, a capillary plexus is already installed, and a few primitive erythroblasts were seen for the first time within the lumen of some blood vessels. Around day 45 pf, an increase in the amount of primitive erythroblasts was detected in the parenchyma surrounding the distal segment of the bronchial tree. The expression of FLT-1, KDR, CD31 and CD34 was observed in endothelial cells of the capillary plexus and the VEGF was detected in the endodermal epithelium. Our results support the hypothesis that the initial formation of the capillary plexus around the tip of the growing airway bud occurs by vasculogenesis, probably regulated by VEGF and KDR. We also showed a very early onset of blood circulation, starting from day 34 pf, concomitant with the generation of new lung buds. In addition, the increasing number of primitive erythroblasts from week 6 onward, associated with a change in the shape of the blood vessels, suggests a remodeling process and that the generation of new distal vessels at the tip of the lung bud occurs mainly by a process of angiogenesis.

Ordered transcriptional factor recruitment and epigenetic regulation of tnf-alpha in necrotizing acute pancreatitis.

Tauhe expression of the critical initiator cytokine TNF-alpha was strongly upregulated in vivo in acute necrotic pancreatitis (AP) in rodents and in vitro in TNF-alpha activated acinar AR42J cells. Upregulation of tnf-alpha, inos, icam-1 and il-6 occurred both in TNF-alpha receptor 1 and 2 knock-out mice, but not in TNF-alpha knock-out mice, in cerulein-induced acute pancreatitis. Chromatin immunoprecipitation analysis showed that transcriptional factors (ELK-1, SP1, NF-kappaB and EGR-1) and chromatin modification complexes (HDAC1, HDAC2, GCN5, PCAF and CBP) were recruited and/or released from the promoter in a strictly ordered mechanism. Activation of tnf-alpha gene was also accompanied by an ordered increased level of histone H3K9, H3K14 and H3K18-acetylation and H3K4 methylation, as well as H4K5 acetylation. A better knowledge of the molecular mechanisms that control tnf-alpha gene regulation will provide deeper understanding of the initiation and development of the inflammatory processes occurring in acute pancreatitis triggered by TNF-alpha cytokine.

Combined treatment for optic disc pit maculopathy secondary to glaucoma.

CASE REPORT: A 58-year-old man was referred to the retina specialist for evaluation of decreased vision in the left eye (LE). At the first visit, visual acuity was 0.9 in right eye (RE) and hands movement in LE, and the intraocular pressure (IOP) was 34 mmHg and 42 mmHg in right and left eye, respectively. Dilated funduscopic examination revealed papillary pallor, increased cup-to-disc ratio of the optic nerve in both eyes, and retinal posterior pole oedema in the LE. Optical coherence tomography (OCT) and fluorescein angiography assessment confirmed the diagnosis of a macular serous retinal detachment (RD) caused by an optic disc pit secondary to glaucoma. Combined surgical treatment with ExPress drainage device implantation, pars plana vitrectomy (PPV), and juxtapapillar laser endophotocoagulation was performed. The IOP returned to normal, as well as complete anatomical resolution of macular RD.

Combined Treatment for Optic Disc Pit Maculopathy Secondary to Glaucoma. / Tratamiento combinado de la maculopatía por foseta papilar secundaria a glaucoma.

CASE REPORT: A 58-year-old man was referred to the retina specialist for evaluation of decreased vision in the left eye (LE). At the first visit, visual acuity was 0.9 in right eye (RE) and hands movement in LE, and the intraocular pressure (IOP) was 34 mmHg and 42 mmHg in right and left eye, respectively. Dilated funduscopic examination revealed papillary pallor, increased cup-to-disc ratio of the optic nerve in both eyes, and retinal posterior pole edema in the LE. Optical coherence tomography (OCT) and fluorescein angiography assessment confirmed the diagnosis of a macular serous retinal detachment (RD) caused by an optic disc pit secondary to glaucoma. Combined surgical treatment with ExPress drainage device implantation, pars plana vitrectomy (PPV), and juxtapapillar laser endophotocoagulation was performed. IOP normalization was achieved as well as complete anatomical resolution of macular RD.

A haplotype of cyclooxygenase-2 gene is associated with idiopathic pulmonary fibrosis.

BACKGROUND: Cyclooxygenase-2, a key regulatory enzyme in the synthesis of the antifibrotic agent prostaglandin E2, is downregulated in lung tissue from patients with idiopathic pulmonary fibrosis. OBJECTIVE: To investigate the association between COX2.3050 (G --> C), COX2.8473 (C --> T) and COX2.926 (G --> C) single nucleotide polymorphisms (SNP) and the susceptibility to idiopathic pulmonary fibrosis and the progression of the disease. DESIGN: Genetic polymorphisms were analyzed in 121 out of 225 available control subjects and in all of 174 patients with idiopathic pulmonary fibrosis by real time polymerase chain reaction. Logistic regression analysis of covariance and chi-squares test were used for statistical analysis. RESULTS: While analysis of disease development did not find any significant association with single SNP genotype, a haplotype analysis revealed a strong association between the disease development and one haplotype [GC] at loci COX2.3050 and COX2.8473, and suggested a recessive genetic effect of this haplotype. Further analysis concluded that subjects having two copies of [GC] haplotype, or equivalently (GG/CC) genotype at the two SNPs, had an increased risk after adjusting for age and sex. Due to the interaction, this elevated risk increased slowly with age, and the estimated odds ratio (OR) decreased with age from OR = 1.4 at age 30 to OR = 1 at age 74 and OR = 0.96 at age SO. The OR was significantly greater than 1 up to age 66, and not significant for age older than 66. Therefore, the recessive effect of [GC] haplotype increased the risk of IPF of subjects younger than 66 years, but its effect diminished for seniors older than 66. One hundred and forty-nine patients with idiopathic pulmonary fibrosis were followed up for 33.7 +/- 2.1 months. Further analysis of disease progressions, defined by the changes in pulmonary function tests, did not reveal any association with either SNP genotypes or haplotypes. CONCLUSIONS: The carriage of double homozygote (GG/CC) at the SNP loci of COX2.3050 and COX2.8473 polymorphisms may increase the susceptibility to idiopathic pulmonary fibrosis, by approximately 1.4 folds at age 30 and by a smaller fold greater than 1 up to age 66 years, but not the progression of the disease. These findings may help to improve our understanding of idiopathic pulmonary fibrosis pathogenesis and may lead to the development of new therapeutic strategies.

Experimental characterization and theoretical analysis of cell tip oscillations in directional solidification.

Experiments performed in DECLIC-DSI on board the International Space Station evidenced oscillatory modes during the directional solidification of a bulk sample of succinonitrile-based transparent alloy. The interferometric data acquired during a reference experiment, V_{p}=1 µm/s and G=19 K/cm, allowed us to reconstruct the cell shape and thus measure the cell tip position, radius, and growth velocity evolution, in order to quantify the dynamics of the oscillating cells. This study completes our previous reports [Bergeon et al., Phys. Rev. Lett. 110, 226102 (2013)10.1103/PhysRevLett.110.226102; Tourret et al., Phys. Rev. E 92, 042401 (2015)10.1103/PhysRevE.92.042401; Pereda et al., Phys. Rev. E 95, 012803 (2017)10.1103/PhysRevE.95.012803] with, to our knowledge, the first complete monitoring of the geometric cell tip characteristics variations in bulk samples. The evolution of the shape, velocity, and position of the tip of the oscillating cells is associated with an evolution of the concentration field, inaccessible experimentally but mediating the diffusive interactions between the cells. The experimental results are supported by 3D phase-field simulations which evidence the existence of transversal solute fluxes between neighboring cells that play a fundamental role in the oscillation dynamics. The dynamics of oscillation of an individual cell is analyzed using a theoretical model based on classical equations of solidification through the calculation of the phase relationships between oscillation of the different tip characteristics.

Linking integrin alpha6beta4-based cell adhesion to the intermediate filament cytoskeleton: direct interaction between the beta4 subunit and plectin at multiple molecular sites.

Recent studies with patients suffering from epidermolysis bullosa simplex associated with muscular dystrophy and the targeted gene disruption in mice suggested that plectin, a versatile cytoskeletal linker and intermediate filament-binding protein, may play an essential role in hemidesmosome integrity and stabilization. To define plectin's interactions with hemidesmosomal proteins on the molecular level, we studied its interaction with the uniquely long cytoplasmic tail domain of the beta4 subunit of the basement membrane laminin receptor integrin alpha6beta4 that has been implicated in connecting the transmembrane integrin complex with hemidesmosome-anchored cytokeratin filaments. In vitro binding and in vivo cotransfection assays, using recombinant mutant forms of both proteins, revealed their direct interaction via multiple molecular domains. Furthermore, we show in vitro self-interaction of integrin beta4 cytoplasmic domains, as well as disruption of intermediate filament network arrays and dislocation of hemidesmosome-associated endogenous plectin upon ectopic overexpression of this domain in PtK2 and/or 804G cells. The close association of plectin molecules with hemidesmosomal structures and their apparent random orientation was indicated by gold immunoelectron microscopy using domain-specific antibodies. Our data support a model in which plectin stabilizes hemidesmosomes, via directly interlinking integrin beta4 subunits and cytokeratin filaments.

Angiotensinogen gene G-6A polymorphism influences idiopathic pulmonary fibrosis disease progression.

Angiotensin II is a growth factor that plays a key role in the physiopathology of idiopathic pulmonary fibrosis (IPF). A nucleotide substitution of an adenine instead of a guanine (G-6A) in the proximal promoter region of angiotensinogen (AGT), the precursor of angiotensin II, has been associated with an increased gene transcription rate. In order to investigate whether the G-6A polymorphism of the AGT gene is associated with IPF development, severity and progression, the present study utilised a case-control study design and genotyped G-6A in 219 patients with IPF and 224 control subjects. The distribution of G-6A genotypes and alleles did not significantly differ between cases and controls. The G-6A polymorphism of the AGT gene was not associated with disease severity at diagnosis. The presence of the A allele was strongly associated with increased alveolar arterial oxygen tension difference during follow-up, after controlling for the confounding factors. Higher alveolar arterial oxygen tension changes over time were observed in patients with the AA genotype (0.37+/-0.7 mmHg (0.049+/-0.093 kPa) per month) compared to GA genotype (0.12+/-1 mmHg (0.016+/-0.133 kPa) per month) and GG genotype (0.2+/-0.6 mmHg (0.027+/-0.080 kPa) per month). G-6A polymorphism of the angiotensinogen gene is associated with idiopathic pulmonary fibrosis progression but not with disease predisposition. This polymorphism could have a predictive significance in idiopathic pulmonary fibrosis patients.

Oxidative stress as a signal to up-regulate gamma-cystathionase in the fetal-to-neonatal transition in rats.

Hepatic gamma-cystathionase, a rate-limiting enzyme for the synthesis of L-cysteine from L-methionine in the trans-sulphuration pathway, exhibits significantly higher activity in the newly born infant as compared to the fetus. The aim of this work was: 1) To determine whether the increase in gamma-cystathionase activity occurring in the fetal-to-neonatal transition is due to up-regulation of its mRNA and protein, 2) To elucidate the mechanisms responsible for this increase in gamma-cystathionase activity. Our results show that expression of gamma-cystathionase at both the mRNA and protein levels was higher in newborn than in fetal liver. gamma-Cystathionase activity in fetal hepatocytes in vitro increased when incubated with tert-butyl-hydroperoxide at low concentration (0.01 mM). Hence, moderate oxidative stress would act as a signal to up-regulate gamma-cystathionase in the fetal to neonatal transition. Stress hormones, such as phenylephrine or glucagon also increased gamma-cystathionase activity in fetal hepatocytes. We also report a competitive inhibition of purified gamma-cystathionase by L-cysteine, which would help to maintain physiological low L-cysteine levels in hepatocytes. In conclusion, our results show that increased hepatic gamma-cystathionase activity in the fetal-to-neonatal transition is due to up-regulation of its gene expression mediated by stress hormones together with the physiological oxidative stress that occurs at birth.

Effects of ultra-high pressure homogenization on microbial and physicochemical shelf life of milk.

The effect of ultra-high pressure homogenization (UHPH) on microbial and physicochemical shelf life of milk during storage at 4 degrees C was studied and compared with a conventional heat preservation technology used in industry. Milk was standardized at 3.5% fat and was processed using a Stansted high-pressure homogenizer. High-pressure treatments applied were 100, 200, and 300 MPa (single stage) with a milk inlet temperature of 40 degrees C, and 200 and 300 MPa (single stage) with a milk inlet temperature of 30 degrees C. The UHPH-treated milks were compared with high-pasteurized milk (PA; 90 degrees C for 15 s). The microbiological quality was studied by enumerating total counts, psychrotropic bacteria, lactococci, lactobacilli, enterococci, coliforms, spores, and Pseudomonas. Physicochemical parameters assessed in milks were viscosity, color, pH, acidity, rate of creaming, particle size, and residual peroxidase and phosphatase activities. Immediately after treatment, UHPH was as efficient (99.99%) in reducing psychrotrophic, lactococci, and total bacteria as was the PA treatment, reaching reductions of 3.5 log cfu/mL. Coliforms, lactobacilli, and enterococci were eliminated. Microbial results of treated milks during storage at 4 degrees C showed that UHPH treatment produced milk with a microbial shelf life between 14 and 18 d, similar to that achieved for PA milk. The UHPH treatments reduced the L* value of treated milks and induced a reduction in viscosity values of milks treated at 200 MPa compared with PA milks; however, these differences would not be appreciated by consumers. In spite of the fat aggregates detected in milks treated at 300 MPa, no creaming was observed in any UHPH-treated milk. Hence, alternative methods such as UHPH may give new opportunities to develop fluid milk with an equivalent shelf life to that of PA milk in terms of microbial and physicochemical characteristics.

Experimental observation of oscillatory cellular patterns in three-dimensional directional solidification.

We present a detailed analysis of oscillatory modes during three-dimensional cellular growth in a diffusive transport regime. We ground our analysis primarily on in situ observations of directional solidification experiments of a transparent succinonitrile 0.24wt% camphor alloy performed in microgravity conditions onboard the International Space Station. This study completes our previous reports [Bergeon et al., Phys. Rev. Lett. 110, 226102 (2013)10.1103/PhysRevLett.110.226102; Tourret et al., Phys. Rev. E 92, 042401 (2015)10.1103/PhysRevE.92.042401] from an experimental perspective, and results are supported by additional phase-field simulations. We analyze the influence of growth parameters, crystal orientation, and sample history on promoting oscillations, and on their spatiotemporal characteristics. Cellular patterns display a remarkably uniform oscillation period throughout the entire array, despite a high array disorder and a wide distribution of primary spacing. Oscillation inhibition may be associated to crystalline disorientation, which stems from polygonization and is manifested as pattern drifting. We determine a drifting velocity threshold above which oscillations are inhibited, thereby demonstrating that inhibition is due to cell drifting and not directly to disorientation, and also explaining the suppression of oscillations when the pulling velocity history favors drifting. Furthermore, we show that the array disorder prevents long-range coherence of oscillations, but not short-range coherence in localized ordered regions. For regions of a few cells exhibiting hexagonal (square) ordering, three (two) subarrays oscillate with a phase shift of approximately ±120^{∘} (180^{∘}), with square ordering occurring preferentially near subgrain boundaries.

[Training cortical signals by means of a BMI-EEG system, its evolution and intervention. A case report]. / Entrenamiento de las señales corticales a traves de un sistema BMI-EEG, evolucion e intervencion. A proposito de un caso.

INTRODUCTION: In the last years, new technologies such as the brain-machine interfaces (BMI) have been incorporated in the rehabilitation process of subjects with stroke. These systems are able to detect motion intention, analyzing the cortical signals using different techniques such as the electroencephalography (EEG). This information could guide different interfaces such as robotic devices, electrical stimulation or virtual reality. CASE REPORT: A 40 years-old man with stroke with two months from the injury participated in this study. We used a BMI based on EEG. The subject's motion intention was analyzed calculating the event-related desynchronization. The upper limb motor function was evaluated with the Fugl-Meyer Assessment and the participant's satisfaction was evaluated using the QUEST 2.0. The intervention using a physical therapist as an interface was carried out without difficulty. CONCLUSIONS: The BMI systems detect cortical changes in a subacute stroke subject. These changes are coherent with the evolution observed using the Fugl-Meyer Assessment.

TITLE: Entrenamiento de las señales corticales a traves de un sistema BMI-EEG, evolucion e intervencion. A proposito de un caso.Introduccion. En los ultimos años estan incorporandose nuevas tecnologias en el tratamiento fisioterapeutico de pacientes con ictus, como las interfaces cerebro-maquina ­brain-machine interface (BMI)­, capaces de detectar la intencion de movimiento analizando las señales corticales por medio de diferentes tecnicas, como la electroencefalografia (EEG). Estas señales se traducen en comandos con el fin de realizar una funcion. Caso clinico. Varon de 40 años con ictus de dos meses de evolucion, en el cual se empleo un dispositivo BMI-EEG. La intencion de movimiento del sujeto se analizo calculando la desincronizacion relacionada con el evento. La funcion motora del miembro superior fue evaluada con la escala de Fugl-Meyer, y el nivel de satisfaccion del paciente, mediante el cuestionario QUEST 2.0. La intervencion se llevo a cabo sin dificultad siendo el fisioterapeuta la interfaz. Conclusiones. Los sistemas BMI-EEG detectan cambios corticales en un sujeto con ictus subagudo. Estos cambios son coherentes con los cambios observados en escalas clinicas.

Co-administration of pentoxifylline and thiopental causes death by acute pulmonary oedema in rats.

BACKGROUND AND PURPOSE: Pentoxifylline exhibits rheological properties that improve microvascular flow and it is widely used in vascular perfusion disorders. It also exhibits marked anti-inflammatory properties by inhibiting tumour necrosis factor alpha production. Thiopental is one of the most widely used drugs for rapid induction of anaesthesia. During experimental studies on the treatment of acute pancreatitis, we observed that when pentoxifylline was administered after anaesthesia with thiopental, most of the rats exhibited dyspnea, signs of pulmonary oedema and died. The aim of the work described here was to investigate the cause of the unexpected toxic effect of the combined treatment with thiopental and pentoxifylline. EXPERIMENTAL APPROACH: Pulmonary vascular permeability and arterial blood gases were measured, and a histological analysis was performed. The possible role of haemodynamic changes in the formation of pulmonary oedema was also assessed. KEY RESULTS: Co-administration of pentoxifylline and thiopental increased pulmonary vascular permeability and markedly decreased arterial pO2, with one third of rats suffering from hypoxemia. This combined treatment caused death by acute pulmonary oedema in 27% of normal rats and aggravated the respiratory insufficiency associated with acute pancreatitis in which the mortality rate increased to 60%. This pulmonary oedema was not mediated by cardiac failure or by pulmonary hypertension. CONCLUSIONS AND IMPLICATIONS: Co-administration of pharmacological doses of pentoxifylline and thiopental caused pulmonary oedema and death in rats. Consequently, pentoxifylline should not be administered when anaesthesia is induced with thiopental to avoid any possible risk of acute pulmonary oedema and death in humans.

Role of cytokines and oxidative stress in the pathophysiology of acute pancreatitis: therapeutical implications.

Severe acute pancreatitis causes a high incidence of mortality due to the systemic inflammatory response syndrome leading to multiple organ failure. At present, there is no treatment against severe acute pancreatitis, other than supportive critical care. The relationship between pancreatic injury and the uncontrolled systemic response is not completely understood. Nevertheless, experimental and clinical evidences have shown that pro-inflammatory cytokines and oxidative stress are critically involved in the development of local and systemic complications associated with severe acute pancreatitis. Serum levels of pro-inflammatory cytokines, such as TNF-alpha and IL-1beta, increase during the course of acute pancreatitis and they appear to be the driving force for the initiation and propagation of the systemic response. Accordingly, pretreatment with an antibody against TNF-alpha or blockade of TNF-alpha production with pentoxifylline ameliorates experimental acute pancreatitis. In addition, serum IL-6 and IL-8 levels appear to be correlated with severity of pancreatic inflammation. The role of oxidative stress in acute pancreatitis has been evidenced indirectly by beneficial effects of antioxidants as well as directly by pancreatic glutathione depletion and increased lipid peroxidation. Furthermore, circulating xanthine oxidase released by the damaged pancreas acts as a source of systemic oxidative stress contributing to lung inflammation. In conclusion, pancreatic injury seems to trigger at least two different pathways, i.e. pro-inflammatory cytokines and oxidative stress, both involved in the systemic effects of acute pancreatitis. Elucidation of these mechanisms and their interactions is critical to develop a treatment based on the pathophysiology of acute pancreatitis.

Congenital syphilis of the eye with lens involvement.

Pathological examination of a girl with congenital syphilis revealed a focal granulomatous reaction involving the anterior uvea and lens. Krajian's (silver) stain exhibited spiral forms that were morphologically compatible with Treponema pallidum within the lens cortex. These findings have been rarely reported in early congenital lues.

Bronchoalveolar lavage for the diagnosis of disseminated toxoplasmosis in AIDS patients.

The usefulness of cell culture of bronchoalveolar lavage fluid for the diagnosis of toxoplasmosis in immunocompromised hosts has not been stressed previously. We report an acquired immunodeficiency syndrome patient with disseminated toxoplasmosis who was diagnosed by isolation of Toxoplasma gondii in cell cultures from bronchoalveolar lavage fluid.

A seven-cell human egg recovered from the oviduct.

A seven-cell human egg recovered from the proximal middle quarter of the oviduct is described. Whether or not it is a normal representative of this stage of human development cannot be established at the present time. The specimen was recovered 83 hours after intercourse and 77 hours after the first significant elevation of the luteinizing hormone level in the urine. According to these data and the results of the endometrial and corpus luteum biopsies, the age of the egg was estimated to be approximately 72 hours. An analysis of size and the reaction of the blastomeres to toluidine blue suggests that they already show some differentiation at this early stage of development. The addition of these findings to previous reports of eggs recovered from human oviducts and uteri gives support to the concept that human eggs are delivered to the endometrial cavity when they contain between 7 and 12 blastomeres.

An electron microscopic study of sperm penetration into the human egg investments.

The ultrastructure of human spermatozoa located in the cumulus cells and the zona pellucida of a pro-nuclear egg, and in the zona pellucida of a two-cell egg, both fertilized in-vivo, has been analysed in order to understand how the human spermatozoon penetrates the investing coats of the oocyte. Among the 36 spermatozoa found in the cumulus cells, 31 were phagocytosed by cumulus cells and 5 were wedged in the matrix between the cells. These spermatozoa were acrosome-reacted and their equatorial segment was intact. Six of the seven spermatozoa found in the zona pellucida (four spermatozoa in the pronuclear egg and three in the two-cell egg) had lost the equatorial segment, while the other one was partially reacted. The sperm heads were located in slits with sharp edges. From these findings it was concluded that in the human (1) only few and normal spermatozoa seem to reach the cumulus cells after natural insemination, (2) the acrosome reaction probably occurs sometime before the spermatozoa reach the vicinity of the corona cells, (3) the reaction of the equatorial segment seems to occur during or before the initial phase of zona penetration, since the spermatozoa located in the matrix of the zona pellucida had no equatorial segment. No evidence of the presence of spermatozoa with an intact acrosome in the matrix of cumulus cells or with an intact equatorial segment in the zona pellucida were found.

Ultrastructure of a two-cell human embryo.

A two-cell human embryo recovered from the Fallopian tube 82 h following the LH peak in plasma and 37 h after a single episode of intercourse was examined by transmission electron microscopy. At the time of recovery the embryo was denuded of cumulus cells, and both the zona pellucida and the two adjoining blastomeres were intact. The finding of two polar bodies in the perivitelline space, two nucleated blastomeres and remnants of the fertilizing sperm tail within the cytoplasm of one of them, were considered as evidences that the embryo was normally fertilized. Among the most conspicuous features found were the presence of very distinct desmosome-like structures between blastomeres, and the cytoplasmic cell organelles distribution in three areas referred as: a sub-cortical, a middle and a perinuclear bands. An outstanding feature was the extensive blebbing of the nuclear envelope. In general, the features seem to correspond to a normally developing two-cell embryo undergoing cleavage at a normal rate.