Resuscitative events in a level 4 NICU: Prevalence, characteristics, and outcomes of compressive versus non-compressive events.

BACKGROUND: Little is known about the prevalence, characteristics, and outcomes of neonates needing emergent resuscitation within the level 4 neonatal intensive care units (NICU). Clinical factors prior to and following resuscitation event or characteristics of those who require chest compressions versus those without compressions has not been previously delineated. The aim of this study is to describe characteristics and outcomes of neonates who have compressive vs. non-compressive resuscitative events. METHODS: Retrospective observational study of neonates with a resuscitative event in the Children's Mercy Hospital level 4 NICU between January 2012 and April 2017. Data were derived from the NICU Code Blue database and the electronic medical record. Primary outcome was survival to hospital discharge. RESULT: Of the 641 resuscitative events, most were in the non-compressive group (n = 481). Those requiring chest compressions longer than 1 minute had significantly different clinical characteristics and decreased survival. There was no difference between groups in gestational age or birth weight. CONCLUSION: Non-compressive events are more common in the NICU setting than are compressive events. Neonates requiring chest compressions longer than 1 minute are more likely to have a higher respiratory severity score, need for vasopressors, worse renal function post-event, and decreased survival to discharge.

In vitro evaluation of the resistance of three types of fixation to treat fractures of the mandibular angle.

The purpose of this study was to compare the mechanical resistance of three different plates used to treat fractures of the mandibular angle: a regular 4-hole plate, a longer 4-hole plate (both positioned using the Champy technique), and a 3-dimensional plate positioned over the oblique line. Three equal groups of replicas of human dentate mandibles made out of polyurethane resin were used (n=21 in each group). The force was applied perpendicular to the occlusal plane at a rate of 2mm/minute at three different points: the first molar on the sectioned side; the first molar on the contralateral side; and between the central incisors. This was followed by a resistance-to-load test. The two varying factors (type of plate and site-of-load application) were tested by analysis of variance, and probabilities of less than 0.05 were accepted as significant. There were no significant differences between the subgroups, or between the mean values of the different types of plates (p=0.925). The three types of plates showed similar mechanical behaviour, which showed that the 3-dimensional plates positioned over the oblique line can produce mechanical scores similar to those of conventional plates.

Retreatment with varenicline for smoking cessation in smokers who have previously taken varenicline: a randomized, placebo-controlled trial.

The efficacy and safety of retreatment with varenicline in smokers attempting to quit were evaluated in this randomized, double-blind, placebo-controlled, multicenter trial (Australia, Belgium, Canada, the Czech Republic, France, Germany, the United Kingdom, and the United States). Participants were generally healthy adult smokers (≥ 10 cigarettes/day) with ≥ 1 prior quit attempt (≥ 2 weeks) using varenicline and no quit attempts in ≤ 3 months; they were randomly assigned (1:1) to 12 weeks' varenicline (n = 251) or placebo (n = 247) treatment, with individual counseling, plus 40 weeks' nontreatment follow-up. The primary efficacy end point was the carbon monoxide-confirmed (≤ 10 ppm) continuous abstinence rate for weeks 9-12, which was 45.0% (varenicline; n = 249) vs. 11.8% (placebo; n = 245; odds ratio: 7.08; 95% confidence interval: 4.34, 11.55; P < 0.0001). Common varenicline group adverse events were nausea, abnormal dreams, and headache, with no reported suicidal behavior. Varenicline is efficacious and well tolerated in smokers who have previously taken it. Abstinence rates are comparable with rates reported for varenicline-naive smokers.

Au Lα x-rays induced by photons from 241Am: Comparison of experimental results and the predictions of PENELOPE.

The results of experiments performed, measuring the Lα x-rays emitted by Au due to excitation by photons of various energies from an (241)Am sample at forward-scattered angles in the range 0° to 65°, are compared to the predictions of the Monte Carlo code, PENELOPE. The experimental data are in good agreement with the predictions of the program. A comparison of the angular distributions of the probability densities (as predicted by the program) related to the Au Lα and Lß x-rays suggests that PENELOPE does not simulate the phenomena described by Flügge et al. (1972).

Immunogenicity and smoking-cessation outcomes for a novel nicotine immunotherapeutic.

NicVAX, a nicotine vaccine (3'AmNic-rEPA), has been clinically evaluated to determine whether higher antibody (Ab) concentrations are associated with higher smoking abstinence rates and whether dosages and frequency of administration are associated with increased Ab response. This randomized, double-blinded, placebo-controlled multicenter clinical trial (N = 301 smokers) tested the results of 200- and 400-µg doses administered four or five times over a period of 6 months, as compared with placebo. 3'AmNic-rEPA recipients with the highest serum antinicotine Ab response (top 30% by area under the curve (AUC)) were significantly more likely than the placebo recipients (24.6% vs. 12.0%, P = 0.024, odds ratio (OR) = 2.69, 95% confidence interval (CI), 1.14-6.37) to attain 8 weeks of continuous abstinence from weeks 19 through 26. The five-injection, 400-µg dose regimen elicited the greatest Ab response and resulted in significantly higher abstinence rates than placebo. This study demonstrates, as proof of concept, that 3'AmNic-rEPA elicits Abs to nicotine and is associated with higher continuous abstinence rates (CAR). Its further development as a treatment for nicotine dependence is therefore justified.

Exercise-induced promotion of hippocampal cell proliferation requires beta-endorphin.

Adult hippocampal neurogenesis is influenced by a variety of stimuli, including exercise, but the mechanisms by which running affects neurogenesis are not yet fully understood. Because beta-endorphin, which is released in response to exercise, increases cell proliferation in vitro, we hypothesized that it could exert a similar effect in vivo and mediate the stimulatory effects of running on neurogenesis. We thus analyzed the effects of voluntary wheel-running on adult neurogenesis (proliferation, differentiation, survival/death) in wild-type and beta-endorphin-deficient mice. In wild-type mice, exercise promoted cell proliferation evaluated by sacrificing animals 24 h after the last 5-bromo-2'-deoxyuridine (BrdU) pulse and by using endogenous cell cycle markers (Ki67 and pH(3)). This was accompanied by an increased survival of 4-wk-old BrdU-labeled cells, leading to a net increase of neurogenesis. Beta-endorphin deficiency had no effect in sedentary mice, but it completely blocked the running-induced increase in cell proliferation; this blockade was accompanied by an increased survival of 4-wk-old cells and a decreased cell death. Altogether, adult neurogenesis was increased in response to exercise in knockout mice. We conclude that beta-endorphin released during running is a key factor for exercise-induced cell proliferation and that a homeostatic balance may regulate the final number of new neurons.

Efecto de la alimentación sobre la producción láctea en llamas seleccionadas para producción de carne / Effect of feed supplementation on milk yied in selected lamas for meat production

Se utilizó 20 llamas gestantes del Centro de Investigaciones IVITA-Maranganí, Cusco, a las que se midió el área de grupa, volumen del muslo, peso corporal y perímetro torácico del rebaño. Se utilizó un diseño factorial 2 x 2, donde A = Suplemento (a1: con heno; a2: sin heno) y B = Medidas biométricas (b1: altas; b2: bajas). La cantidad de heno de alfalfa fue de 1 kg/animal/día. Se midió el efecto de las medidas biométricas y la suplementación sobre la producción de leche y tasa de crecimiento de las crías durante las primeras siete semanas de lactación. Se registró semanalmente el peso de la madre y la cría y se estimó la producción de leche (producción de 12 horas luego del uso de un protector de ubre que impide el amamantamiento). Las llamas que recibieron suplemento tuvieron una mayor producción de leche (0.05>p<0.01) entre la 3ra a la 7ma semana de lactancia. El pico de la producción de leche ocurrió a la 2da (a2) y 3ra (a1) semana. Las crías de las llamas suplementadas y de aquellas con medidas biométricas altas tuvieron las mayores ganancias de peso (p<0.05). No hubo interacción significativa entre los efectos de los tratamientos en el peso de las crías; no obstante, se observó una mayor tasa de crecimiento en las crías de madres suplementadas con medidas biométricas altas. La correlación entre la producción de leche con el peso de las crías por efecto del suplemento y de las medidas biométricas de las madres fueron significativas a partir de la cuarta semana de lactación. El efecto de la suplementación con heno y las medidas biométricas, así como la interacción entre las dos variables, no afectó significativamente el peso de las madres durante las primeras siete semanas de lactación, aunque se pudo observar una ligera disminución de peso corporal entre la 1ra y 3ra semana de lactancia. El peso promedio al parto y en la 7ma semana de lactación fue de 96.9 ± 8.4 y 95.3 ± 9.1 kg, respectivamente. Se ...

Twenty pregnant lamas from the IVITA Research Center, Maranganí, Cusco, were selected, and the rump area, thigh volume, body weight and thoracic perimeter were measured. A 2 x 2 factorial design was used, where A = Supplement (a1: with hay; a2: without hay) and B = Biometric measures (b1: high values; b 2: low values). The amount of supplemented hay was 1 kg/animal/day. The effect of biometric measures and feed supplementation on dam milk production and calf growth during the first seven weeks of lactation was evaluated. Body weight of both dams and calves was weekly recorded. Milk production was estimated (milking after 12 hours of wearing an udder protector to avoid suckling). Supplemented lamas showed higher milk yield (0.05>p<0.01) between the 3rd and 7th week of lactation. The peak of milk production occurred at the 2nd (a2) and 3rd (a1) week. Calves of supplemented lamas and those with higher biometric measures had the highest body weight gain (p<0.05). No significant interaction was found between treated groups on calf weight; however, there was a higher growth rate in calves of supplemented lamas with high biometric measures. Correlations between milk yield with calf body weight due to the effect of feed supplementation and biometric measures were significant from the 4th week onwards. The effect of feed supplementation and biometric measures, and the interaction between them did no significantly affect dams body weight during the first weeks of lactation, however, there was a slight reduction of body weight between the 1st and the 3rd week of lactation. The average body weight at parturition and on the 7th week of lactation was 96.9 ± 8.4 and 95.3 ± 9.1 kg respectively. The ...

Video capture of clinical care to enhance patient safety.

Experience from other domains suggests that videotaping and analyzing actual clinical care can provide valuable insights for enhancing patient safety through improvements in the process of care. Methods are described for the videotaping and analysis of clinical care using a high quality portable multi-angle digital video system that enables simultaneous capture of vital signs and time code synchronization of all data streams. An observer can conduct clinician performance assessment (such as workload measurements or behavioral task analysis) either in real time (during videotaping) or while viewing previously recorded videotapes. Supplemental data are synchronized with the video record and stored electronically in a hierarchical database. The video records are transferred to DVD, resulting in a small, cheap, and accessible archive. A number of technical and logistical issues are discussed, including consent of patients and clinicians, maintaining subject privacy and confidentiality, and data security. Using anesthesiology as a test environment, over 270 clinical cases (872 hours) have been successfully videotaped and processed using the system.

[The Charles Bonnet syndrome: a case report and a brief review]. / Síndrome de Charles Bonnet: exposición de un caso y breve revisión.

The Charles Bonnet syndrome (CBS) is a rare disease that also seems to be generally misdiagnosed. Initially described in the XVIII century by the philosopher with the same name, it consist in complex visual hallucinations in elderly people who suffer sensory deprivation with no other psychopathology. The hypothesis on the neurophysiology of hallucinations suggests, as in other diseases that present hallucinations, some implication of thalamus-cortex pathway release. Some authors have proposed CBS as an early marker of dementia and Parkinson's disease. Nevertheless, the results in functional neuroimaging are not conclusive. Regarding treatment, typical and atypical neuroleptics do not seem to be useful and recent studies suggest that the new anticonvulsants could be effcient. The patient should be informed about CBS as a <>. In the case reported, the patient presented complex hallucinations with normal SPECT and neuropsychological examinations. The patient did not respond to treatment with risperidone, presenting a favorable evolucion with valpromide. Although further research is needed, this case report supports the efficacy of valpromide in CBS.

Sustained-release bupropion for pharmacologic relapse prevention after smoking cessation. a randomized, controlled trial.

BACKGROUND: Smoking relapse is common after successful pharmacologic treatment for smoking cessation. No previous studies have examined long-term drug therapy used expressly for prevention of smoking relapse. OBJECTIVE: To evaluate the efficacy of bupropion to prevent smoking relapse. DESIGN: Randomized, placebo-controlled trial. PARTICIPANTS: 784 healthy community volunteers who were motivated to quit smoking and who smoked at least 15 cigarettes per day. INTERVENTION: The participants received open-label, sustained-release bupropion, 300 mg/d, for 7 weeks. Participants who were abstinent throughout week 7 of open-label treatment were randomly assigned to receive bupropion, 300 mg/d, or placebo for 45 weeks and were subsequently followed for an additional year after the conclusion of the medication phase. Participants were briefly counseled at all follow-up visits. At the end of open-label bupropion treatment, 461 of 784 participants (58.8%) were abstinent from smoking. MEASUREMENT: Self-reported abstinence was confirmed by an expired air carbon monoxide concentration of 10 parts per million or less. RESULTS: The point prevalence of smoking abstinence was significantly higher in the bupropion group than in the placebo group at the end (week 52) of drug therapy (55.1% vs. 42.3%, respectively; P = 0.008) and at week 78 (47.7% vs. 37.7%; P = 0.034) but did not differ at the final (week 104) follow-up visit (41.6% vs. 40.0%). The median time to relapse was significantly greater for bupropion recipients than for placebo recipients (156 days vs. 65 days; P = 0.021). The continuous abstinence rate was higher in the bupropion group than in the placebo group at study week 24 (17 weeks after randomization) (52.3% vs. 42.3%; P = 0.037) but did not differ between groups after week 24. Weight gain was significantly less in the bupropion group than in the placebo group at study weeks 52 (3.8 kg vs. 5.6 kg; P = 0.002) and 104 (4.1 kg vs. 5.4 kg; P = 0.016). CONCLUSIONS: In persons who stopped smoking with 7 weeks of bupropion treatment, sustained-release bupropion for 12 months delayed smoking relapse and resulted in less weight gain.

Bupropion SR as an aid to smoking cessation in smokers treated previously with bupropion: a randomized placebo-controlled study.

BACKGROUND: Many persons who attempt to quit smoking have made previous unsuccessful attempts to quit with pharmacologic aids. An understanding of the impact of these previous attempts to quit is vital for selecting medications that may be more successful in a future attempt to quit. In particular, the effect of repeated use of bupropion SR (Zyban; INN, amfebutamone) on abstinence rates has not been studied previously. METHODS: This was a multicenter, randomized, double-blind, placebo-controlled study in 450 smokers who had previously used bupropion in a smoking cessation attempt. The study consisted of a screening phase, a 12-week treatment phase, and a follow-up at month 6. Participants made regular clinic visits throughout the treatment phase during which they received brief counseling sessions to encourage abstinence from smoking. The primary end point was continuous abstinence from smoking from weeks 4 through 7. Secondary efficacy end points were examined throughout the treatment phase and at follow-up after 6 months. RESULTS: In participants receiving bupropion SR, 27% (61 of 226) remained abstinent throughout the period from weeks 4 through 7 compared with 5% (11 of 224) of participants receiving placebo (P <.001). Significantly (P <.001) more participants who received bupropion SR during the treatment phase remained continuously abstinent from the start of week 4 through month 6 (27 of 226; 12%) compared with participants who received placebo (5 of 224; 2%). Eleven participants receiving placebo (5%) and 19 participants receiving bupropion SR (8%) stopped taking the study medication because of an adverse event. CONCLUSIONS: Bupropion SR is an effective medication for retreatment of smokers who have used bupropion SR previously.

Smoking cessation in patients with chronic obstructive pulmonary disease: a double-blind, placebo-controlled, randomised trial.

BACKGROUND: Tobacco smoking is associated with chronic obstructive pulmonary disease (COPD) in more than 80% of cases. Our aim was to investigate the effect of sustained-release bupropion (amfebutamone) (SR) in promoting abstinence from smoking in patients with COPD. METHODS: In a double-blind, randomised, placebo-controlled trial 404 individuals with mild or moderate COPD who smoked 15 or more cigarettes per day, were assigned bupropion SR (150 mg twice daily) or placebo for 12 weeks. All patients received smoking cessation counselling. Study medication was taken for 1 week before patients attempted to stop smoking. The primary efficacy endpoint was the complete and continuous abstinence from smoking from the beginning of week 4 to the end of week 7. Participants were followed up at month 6. Analysis was by intention to treat. FINDINGS: All patients were chronic smokers with a smoking history of about 51 pack-years. Continuous smoking abstinence rates from week 4 to 7 were significantly higher in participants receiving bupropion SR than in those receiving placebo (28% [57/204] vs 16% [32/200], p=0.003). Continuous abstinence rates from weeks 4 to 12 (18% [36/204] vs 10% [20/200]) and weeks 4 to 26 (16% [32/204] vs 9% [18/200]) were also higher in participants receiving bupropion SR than in those taking placebo (p<0.05). Furthermore, symptoms of tobacco craving and withdrawal were attenuated in those receiving bupropion SR. Seven individuals discontinued study medication because of adverse events. INTERPRETATION: Bupropion SRis a well-tolerated and effective aid to smoking cessation in people with mild to moderate COPD.

Synchronous water-clear cell double parathyroid adenomas a hitherto uncharacterized entity?

Water-clear cell hyperplasia is a rare but well-documented cause of primary hyperparathyroidism. Parathyroid adenomas of the water-clear cell type are exceptionally rare, and only 2 cases have been reported. We describe a patient with synchronous water-clear cell double parathyroid adenomas, an entity that has not previously been reported. In our case, the enlarged superior parathyroid glands were completely replaced by water-clear cells, with only a minute rim of extracapsular, histologically unremarkable parathyroid tissue. The inferior parathyroid glands were grossly unremarkable, and incisional biopsy specimens were histologically normal (no foci of water-clear cells were identified). The findings in this case are most consistent with the diagnosis of double adenomas of the water-clear cell type. We acknowledge that despite molecular proof of monoclonality of the 2 lesions, it is not possible to entirely exclude the possibility that this unusual case could be due to asymmetric hyperplasia.

In utero and in vitro proteinase activity during the Mesocricetus auratus embryo zona escape time window.

The goal of the present study was to investigate proteinase activity in uterine flushates collected during the zona loss time window (68-80 h post-egg activation) in both pregnant and pseudopregnant hamsters and in culture medium conditioned by hatching blastocysts. Several prominent enzyme activities appeared in all pregnant and pseudopregnant uterine flushates. However, only a 45, 43 x 10(-3) M:(r) doublet coincided with the zona loss time window; these bands were absent outside of this time window and were not found in conditioned medium. In medium conditioned by hatching blastocysts, enzyme activity was represented by a 70, 65 x 10(-3) M:(r) doublet identical to a doublet seen in all uterine flushates collected and in serum. There were 12 pregnant and 8 pseudopregnant uterine flushates that were capable of zona lytic activity in vitro (positive bioassays). Of these positive bioassays, five pregnant and four pseudopregnant uterine flushates exhibited the 45, 43 x 10(-3) M:(r) doublet (correlative positive bioassays). These data suggest that there is an important uterine contribution to blastocyst escape from the zona pellucida, consisting of proteinases secreted during a finite time window prior to blastocyst attachment that are different from the proteinases responsible for the zona lytic activity in vitro.

Instability studies of porcine somatotropin in aqueous solutions and the possible reagents for its stabilization.

The instability of porcine somatotropin (pST) in various solutions and possible stabilization of the hormone by sugars and mild detergents were studied. Aggregation and decomposition of the hormone molecules in various pH solutions and under presence of sugar or detergent were monitored by gel permeation chromatography (GPC) or ultraviolet spectroscopy (UV). The pST is a very unstable hormone in an aqueous environment. It was found in this project that the peptide hormone underwent aggregation or decomposition quickly in acidic and alkaline solutions but slowly in neutral pH solutions. High losses of pST monomers were seen in concentrated solutions of the hormone. On the other hand, pST monomers were stabilized to a certain degree in glucose solutions and at a low concentration of urea. These results should facilitate the development of efficient controlled-release systems which are essential for commercializing porcine somatotropin.

Antimicrobial resistance in the subgingival microflora in patients with adult periodontitis. A comparison between The Netherlands and Spain.

BACKGROUND: The widespread use of antibiotics for prophylaxis and treatment of bacterial infections has lead to the emergence of resistant human pathogens. Great differences have been documented between European countries in the use of systemic antibiotics. In parallel, significant differences in levels of resistant pathogens have been documented. AIM: To investigate whether differences in antibiotic use influence the level of antimicrobial resistance of the subgingival microflora of untreated patients with adult periodontitis in The Netherlands and Spain. METHOD: Blood agar plates containing breakpoint concentrations of penicillin, amoxicillin, amoxicillin and clavunalate, metronidazole, erythromycin, azithromycin, clindamycin and tetracycline were used to determine the proportion of bacteria from the subgingival plaque that was resistant to these antibiotics. In the Spanish patients, statistically significant higher mean levels of resistance were found for penicillin, amoxicillin, metronidazole, clindamycin and tetracycline. The mean number of different bacterial species growing on the selective plates was higher in the Spanish patients, as was the % of resistant strains of most periodontal pathogens. A striking difference was observed in the frequency of occurrence of tetracycline-resistant periodontal pathogens. In Spain, 5 patients had > or =3 tetracycline resistant periodontal pathogens, whereas this was not observed in any of the Dutch patients. CONCLUSIONS: The widespread use of antibiotics in Spain is reflected in the level of resistance of the subgingival microflora of adult patients with periodontitis.

Trasplante Hepático experimental en modelo animal : resultados preliminares de la fase 1 de un programa / Annual Reports 1997 / Experimental liver transplantation in animals : preliminar y results of a program

Esta comunicación, basada en los resultados de la primera fase del proyecto y cuyo diseño reproduce lo publicado por otro grupo, tiene por objetivo incentivar la creación de la condiciones médicas, legales y financieras adecuada para la puesta en marcha de un programa de trasplante hepático en el Paraguay. La serie incluye 26 cerdos intervenidos quirúrgicamente en el hospital de la Facultad de Ciencias Veterinarias entre junio de 1996 y diciembre 1997 por un grupo de médicos y veterinarios; se realizaron 8 ablaciones hepáticas (en donantes), 8 hepatectomías (en receptores) y 5 trasplantes (donantes y receptores). Los resultados indican que la cirugía del trasplante hepático puede ser realizada con seguridad en cerdos y que las similitudes de estos animales con el hombre autoriza la incorporación de esta cirugía a un programa nacional de trasplante

Inactivation of glutathione reductase by 4-hydroxynonenal and other endogenous aldehydes.

4-Hydroxynonenal, a product of oxidative degradation of unsaturated lipids, is an endogenous reactive alpha,beta-unsaturated aldehyde with numerous biological activities. 4-Hydroxynonenal rapidly inactivated glutathione reductase in an NADPH-dependent reaction. Inactivation appears to involve the initial formation of an enzyme-inactivator complex, K(D) = 0.5 microM, followed by the inactivation reaction, k = 1.3 x 10(-2) min(-1). alpha,beta-Unsaturated aldehydes such as acrolein, crotonaldehyde, and cinnamaldehyde also inactivated glutathione reductase, although rates varied widely. Inactivation of glutathione reductase by alpha,beta-unsaturated aldehydes was followed by slower NADPH-independent reactions that led to formation of nonfluorescent cross-linked products, accompanied by loss of lysine and histidine residues. Other reactive endogenous aldehydes such as methylglyoxal, 3-deoxyglucosone, and xylosone inactivated glutathione reductase by an NADPH-independent mechanism, with methylglyoxal being the most reactive. However, 2-oxoaldehydes were much less effective than 4-hydroxynonenal. Inactivation of glutathione reductase by these 2-oxoaldehydes was followed by slower reactions that led to the formation of fluorescent cross-linked products over a period of several weeks. These changes were accompanied by loss of arginine residues. Thus, the sequence of events is different for inactivation and modification of glutathione reductase by alpha,beta-unsaturated aldehydes compared with 2-oxoaldehydes with respect to kinetics, NADPH requirements, fluorescence changes, and loss of amino acid residues. The ability of 4-hydroxynonenal at low concentrations to inactivate glutathione reductase, a central antioxidant enzyme, suggests that oxidative degradation of unsaturated lipids may initiate a positive feedback loop that enhances the potential for oxidative damage.

Trophectoderm projections: a potential means for locomotion, attachment and implantation of bovine, equine and human blastocysts.

The behaviour of bovine, equine and human blastocysts was studied in vitro by time-lapse videomicrography and computer imaging. This study revealed that cytoplasmic extensions of the trophectoderm ['trophectoderm projections' (TEP)] were expressed by embryos of all three species, prior to or during zona escape. Bovine and human blastocysts escaped their zonae with a combination of blastocoele expansion, collapse and re-expansion coupled with the penetration of the zona pellucida by TEP. In equine embryos, after several cycles of blastocoele expansion and collapse, trophectoderm ruptured the zona with the concomitant appearance of TEP. This study provides documentation that TEP are expressed by a diverse range of mammalian species, bringing the total number of species in which this phenomenon is found to six, since TEP are also known to be expressed by guinea-pig, hamster and rhesus monkey blastocysts, representing rodents, ungulates and primates. In all species studied, the dynamic nature (extension, retraction, and angular movement) of the TEP was similar, moving in an undulating manner with rapid cycles of extension and retraction. Because TEP appear to be a general feature of mammalian blastocysts, they are implicated in one or more key events in early development, namely zona escape, attachment and/or implantation.