Balloon-Expandable Pulmonary Valves for Patched or Native Right Ventricular Outflow Tracts.

The implantation of percutaneous balloon expandable valves in native or patched right ventricular outflow tracts (nRVOT) is a challenging technique due to the diversity of anatomies and shapes, the large sizes, and the distensibility of the nRVOT, for which specific techniques have been developed. We present a single center experience with balloon expandable percutaneous pulmonary valves in nRVOT, describing the techniques used, complications observed, and a short-mid term follow-up.. This is a single center descriptive study of patients who underwent a percutaneous pulmonary valve implantation in a nRVOT with a balloon expandable pulmonary valve in our center between September 2012 and June 2022.. We implanted successfully 45 valves in 46 patients (20 Sapien and 25 Melody). Tetralogy of Fallot or pulmonary atresia with VSD were the main congenital heart disease (n = 32). All were pre-stented, 18 in a one step procedure. We used a Dryseal sheath in 13/21 Sapien. In 6 patients we used the anchoring technique, 5 with a very large nRVOT and one pyramidal nRVOT. In the 3.5 year follow-up 7 patients developed endocarditis and 3 required a valve redilation, no fractures were observed. PPVI of native RVOT with balloon expandable valves is feasible in a number of selected anatomies, including large or pyramidal nRVOT, using specific techniques, (presenting, LPA anchoring).

Analysis of the validity of the five-level TRIPED-GM paediatric triage system.

OBJECTIVE: To determine the validity of the five-level TRIPED-GM pediatric triage system. METHODS: Unicentric, observational, descriptive, cross-sectional study of 485 patients aged 0-16 years in the pediatric emergency department of the HGU Gregorio Marañon. Two measures of validity were used: a direct measure calculated by the sensitivity and specificity obtained based on the number of infratriages and overtriages of the priorities given by classification nurses compared with a panel of experts and another indirect measure by the length of stay, the resources consumed and the percentage of income for each priority level. RESULTS: 10 patients were incorrectly classified, 4 (0.8%) were considered infratriages and 6 (1.2%) overtriages. The results showed a sensitivity of 99.45% (95% CI 96.5-99.97%) and a specificity of 99.01% (95% CI 96.9-99.7%) for high priorities (P2 and P3) and 98.99% (95% CI 96.8-99.6%) and 98.4% (95% CI 96.84-99.74%) respectively for low priorities (P4 and P5). The quadratic weighted Kappa index was 0.96 (95% CI 0.94-0.98; p = 0.0000). Resource consumption showed moderate Spearman correlation coefficients as the priority level increased. The percentage of admissions and the need for observation increased as the priority level p = 0,000 increased, not requiring observation or admitting any patients with priority 5. CONCLUSIONS: The TRIPED-GM pediatric triage system is valid for use in emergency departments with similar patients.

Difteria: Experiencia en el servicio de enfermedades infecciosas del Hospital Universitario de Caracas

Difteria es una enfermedad infecciosa bacteriana producida por Corynebacterium diphtheriae, es altamente contagiosa, prevenible por vacunas, con importantes complicaciones agudas y alta mortalidad. Objetivo: Describir las características clínicoepidemiológicas y el manejo médico de los pacientes con diagnóstico de Difteria ingresados en el Servicio de Enfermedades Infecciosas del Adulto del Hospital Universitario de Caracas (HUC) en los años 2017 y 2018. Metodología: Estudio de casos, analítico, retrospectivo, de revisión de historias clínicas. Resultados: Ingresaron 27 pacientes de los cuales se encontraron 22 historias clínicas y se excluyeron 2. De los 20 pacientes 13 (65 %) ingresaron en el año 2017 y 7 (35 %) hasta mayo del 2018. Predominó el género masculino 11 (55 %). La mayoría eran procedentes del Distrito Capital 9 (45 %), seguido del estado Miranda 8 (40 %). El promedio de edad fue de 26 años. La mayoría 8 (40 %) no tenían reportes de datos epidemiológicos en la historia clínica, 7 (35 %) negaron viajes recientes, 3 (15 %) estaban vacunados. La mayoría de los pacientes consultaron por fiebre, odinia y odinofagia 13 (65 %), seguido de fiebre y odinia 6 (30 %), el 100 % tuvo membrana blanco grisácea como clínica primaria, seguido de edema de cuello 10 (50 %). La ubicación de las membranas fue más frecuente en amígdalas palatinas 15 (75 %), con 9 casos (45 %) de formas extensivas a úvula, paladar blando y paredes de orofaringe. Las complicaciones al ingreso fueron respiratorias 9 (45 %) y neurológicas 1 (5 %). El tratamiento fue penicilina cristalina en 12 casos (60 %) y antitoxina diftérica (ATD) en el 100 %, la mayoría administrada en las primeras 24 hrs 9 (45 %). Un paciente presentó polineuropatía y 1 falleció por insuficiencia respiratoria. Conclusiones: El HUC es un centro de referencia y es pertinente determinar las características clínico-epidemiológicas y el manejo médico de los pacientes hospitalizados con diagnóstico de difteria, en el contexto de la actual epidemia.

Diphtheria is a bacterial infectious disease caused by Corynebacterium diphtheriae, it is highly contagious, preventable by vaccines, with important acute complications and high mortality. Objective: To describe the clinical-epidemiological characteristics and medical management of patients diagnosed with Diphtheria admitted to the Adult Infectious Diseases Service of the Hospital Universitario de Caracas (HUC) in the years 2017 and 2018. Methodology: Case study, analytical , retrospective, review of medical records. Results: 27 patients were admitted, of which 22 clinical records were found and 2 were excluded. Of the 20 patients, 13 (65%) entered in 2017 and 7 (35%) up to May 2018. The male gender predominated 11 (55 %). Most were from Distrito Capital 9 (45%), followed by Miranda 8 (40%). The average age was 26 years. The majority 8 (40%) had no reports of epidemiological data in the clinical history, 7 (35%) denied recent trips, 3 (15%) were vaccinated. The majority of patients consulted for fever, odinia and odynophagia 13 (65%), followed by fever and odinia 6 (30%), 100% had grayish white membrane as primary clinic, followed by neck edema 10 (50%) . The location of the membranes was more frequent in palatine tonsils 15 (75%), with 9 cases (45%) of extensive forms to the uvula, soft palate and walls of the oropharynx. Complications at admission were respiratory 9 (45%) and neurological 1 (5%). The treatment was crystalline penicillin in 12 cases (60%) and diphtheria antitoxin (DAT) in 100%, the majority administered in the first 24 h 9 (45%). One patient presented polyneuropathy and 1 died due to respiratory failure. Conclusions: The HUC is a reference center and it is pertinent to determine the clinical-epidemiological characteristics and medical management of hospitalized patients diagnosed with diphtheria, in the context of the current epidemic.

Volar Central Portal in Wrist Arthroscopy.

Background Nowadays, the wrist is not limited to a dorsal visualization; the joint can be thought of as a "box," which can be visualized from almost every perspective. The purpose of this study was to describe a new volar central portal for the wrist, following three principles: a single incision that allows access to both the radiocarpal and midcarpal joints, centered on the lunate, with the volar structures at risk protected not only by retractors, but also by tendons. Description of Technique The incision begins in the distal wrist crease and extended 1.5 cm proximally up to the proximal wrist crease, following the axis of the third intermetacarpal space. The flexor superficialis tendons are identified and retracted toward the radial side. Next, the fourth and fifth flexor digitorum profundus tendons are retracted toward the ulnar side, while the third and second tendons are retracted toward the radial side. The volar central midcarpal portal is performed under direct vision just over the anterior horn of the lunate through the Poirier space. The volar central radiocarpal portal is created under the lunate through the interval between the ulnocarpal ligaments and the short radioulnar ligament. Methods An anatomical study was performed on 14 cadaver specimens. Two data were recorded: iatrogenic injuries of the structures at risk and the distances to the structures at risk. Results The median (interquartile range [IQR]) distances from the volar central radiocarpal portal to the median nerve, palmar cutaneous branch of the median nerve, and ulnar neurovascular bundle were 10.5 (7.8-15.0), 18.5 (15.8-20.3), and 7.0 (5.0-10.5) mm, respectively. The median (IQR) distances from the volar central midcarpal portal to the median nerve, palmar cutaneous branch of the median nerve, and ulnar neurovascular bundle were 7.0 (4.8-10.3), 16.0 (14.8-19.0), and 4.5 (3.8-9.0) mm, respectively. No iatrogenic injuries were observed. Conclusion The volar central portal is reproducible and safe. The risk of iatrogenic injury is low. The capsule is pierced through one of its thinner portions, and both the radiocarpal and midcarpal joints can be inspected through one single incision.

Timing of Pulmonary Valve Replacement: How Much Can the Right Ventricle Dilate Before it Looses Its Remodeling Potential?

Congenital heart disease patients that develop secondary pulmonary regurgitation require a pulmonary valve replacement (PVR) in their follow-up. The indications for PVR in asymptomatic patients are debated. Most guidelines consider a RV end-diastolic volume (RVEDV) over 150 ml/m(2) as an indication for PVR. We analyzed clinical, echocardiographic and MRI variables of patients that underwent a surgical PVR between September 2006 and February 2013. The included patients were asymptomatic, without pulmonary stenosis and with both pre- and post-surgery MRI. Thirty-five patients (74.3 % males) were included. Mean age at PVR was 25.8 years (SD = 7.18), and weight was 64.5 Kg (SD = 12.03). The main diagnosis was tetralogy of Fallot (n = 28), pulmonary atresia (n = 2), primary pulmonary regurgitation (n = 2) and pulmonary regurgitation after percutaneous treatment (n = 2). The maximal RVEDV pre-PVR was 267 ml/m(2), and right ventricular end-systolic volume (RVESV) was 183 ml/m(2). RV size and function were established by MRI: Pre-PVR Post-PVR p RVEDV (ml/m(2)) 162 (SD = 39.1) 94 (SD = 23.6) <0.001 RVESV (ml/m(2)) 87 (SD = 28.9) 44 (SD = 15.7) <0.001 RVEF 44.8 % (SD = 8.17) 52 % (SD = 9.9) <0.001 Patients with a RVEDV under 170 ml/m(2) combined with a RVESV under 90 ml/m(2) had a favorable RV remodeling, defined as RVEDV under 110 ml/m(2) (sensitivity 87.5 %), RVESV under 55 ml/m(2) (sensitivity 100 %) and RVEF over 50 % (sensitivity 100 %). When deciding the optimal PVR timing in asymptomatic patients, both RVEDV and RVESV should be considered. Our results suggest that higher volumes than used in the clinical practice can achieve a good remodeling. Therefore, PVR could be performed later in the follow-up reducing the number of cardiac interventions.

Environmental prenatal stress eliminates brain and maternal behavioral sex differences and alters hormone levels in female rats.

Environmental prenatal stress (EPS) has effects on fetuses that are long-lasting, altering their hormone levels, brain morphology and behavior when they reach maturity. In previous research, we demonstrated that EPS affects the expression of induced maternal behavior (MB), the neuroendocrine system, and morphology of the sexually dimorphic accessory olfactory bulb (AOB) involved in reproductive behavior patterns. The bed nucleus of the accessory olfactory tract (BAOT) is another vomeronasal (VN) structure that plays an inhibitory role in rats in the expression of induced maternal behavior in female and male virgins. In the present study, we have ascertained whether the behavioral, neuroendocrine, and neuromorphological alterations of the AOB found after EPS also appear in the BAOT. After applying EPS to pregnant rats during the late gestational period, in their female offspring at maturity we tested induced maternal behavior, BAOT morphology and plasma levels of testosterone (T), estradiol (E2), progesterone (P), adrenocorticotropic hormone (ACTH) and corticosterone (Cpd B). EPS: a) affected the induction of MB, showed a male-like pattern of care for pups, b) elevated plasma levels of Cpd B and reduced E2 in comparison with the controls, and c) significantly increased the number of BAOT neurons compared to the control females and comparable to the control male group. These findings provide further evidence that stress applied to pregnant rats produces long-lasting behavioral, endocrine and neuroanatomical alterations in the female offspring that are evident when they become mature.

[Questionnaire to evaluate the importance of the family in nursing care. Validation of the Spanish version (FINC-NA)]. / Cuestionario para evaluar la importancia de la familia en los cuidados de enfermería. Validación de la versión española (FINC-NA).

BACKGROUND: The nursing profession is focused on patient care, without forgetting that patients are part of a social group, the family. The aim of this study was the adaptation of the "Families' Importance in Nursing Care-Nurses' Attitudes" (FINC-NA) scale to the Spanish language and its validation. METHODS: A descriptive cross-sectional study was carried out, using the bidirectional translation method for linguistic-cultural adaptation. It was applied to the nursing staff in the Paediatric Department of a University Hospital in Madrid. To evaluate the psychometric properties of the Spanish version, reliability, internal consistence and construct validity were calculated. RESULTS: The sample consisted of 274 professionals. Cronbach´s Alpha coefficient for the total scale was 0.864, oscillating between 0.888 and 0.769 in the subscales. The principal components factor analysis identified 4 factors, which explained 54.22% of total variance. CONCLUSIONS: The new instrument makes it possible to determine the importance nurses give to participation by family members and their attitude to involving the latter in patient care, and the possibility of involving them in planning. It has been adapted to the Spanish population with good psychometrics results and enough evidence for its use in this context.

Alveolar capillary dysplasia with misalignment of the pulmonary veins associated with aortic coarctation and intestinal malrotation.

Alveolar capillary dysplasia with misalignment of the pulmonary veins (ACD/MPV) is a rare and lethal cause of refractory pulmonary hypertension of the newborn. We describe the clinical course of a neonate with refractory pulmonary hypertension diagnosed with ACD/MPV, aortic coarctation and other not previously reported associated malformations.

Safety and tolerability of targeted therapies for pulmonary hypertension in children.

The objective of this study is to evaluate the safety and tolerability of the pharmacological treatment of pulmonary hypertension in pediatric patients. It is a retrospective, longitudinal, observational study on pediatric patients undergoing treatment with pulmonary targeted therapies. 63 patients were included (51% male), with a median age of 3.4 years (IQR, 3.6 months-10 years) and a median weight 13 kg (IQR, 6-30 kg). Congenital heart disease was the etiology of pulmonary hypertension in the majority of cases (n = 33) and 28 patients were in NYHA functional class III-IV. The most commonly used drug was sildenafil (n = 79, 56%), followed by bosentan (n = 27, 23%), and a combination of both (n = 14, 41%). 34 patients had adverse reactions (54%) with an incidence rate of 1.02 per patient per year. The most commonly reported reactions were gastrointestinal symptoms (22%) and spontaneous erections (22%) in males. Nine severe adverse reactions (10%) occurred, requiring eight treatment withdrawal and one hospital admission. Treatment with targeted therapies for pulmonary hypertension is safe in the pediatric population. Severe ADRs were uncommon both in monotherapy and in combination therapy. Combination therapy was associated with a higher rate of ADRs. We observed similar survival rates in children receiving sildenafil doses according to the European Medicines Agency (EMA) recommendations or higher.

Maternal care interacts with prenatal stress in altering sexual dimorphism in male rats.

The present study analyzes the interaction between prenatal stress and mother's behavior on brain, hormonal, and behavioral development of male offspring in rats. It extends to males our previous findings, in females, that maternal care can alter behavioral dimorphism that becomes evident in the neonates when they mature. Experiment 1 compares the maternal behavior of foster mothers toward cross-fostered pups versus mothers rearing their own litters. Experiment 2 ascertains the induced "maternal" behavior of the male pups, derived from Experiment 1 when they reached maturity. The most striking effect was that the males non-exposed to the stress as fetuses and raised by stressed foster mothers showed the highest levels of "maternal" behavior of all the groups (i.e., induction of maternal behavior and retrieving behavior), not differing from the control, unstressed, female groups. Furthermore, those males showed significantly fewer olfactory bulb mitral cells than the control males that were non-stressed as fetuses and raised by their own non-stressed mothers. They also presented the lowest levels of plasma testosterone of all the male groups. The present findings provide evidence that prenatal environmental stress can "demasculinize" the behavior, brain anatomy and hormone secretion in the male fetuses expressed when they reach maturity. Moreover, the nature of the maternal care received by neonates can affect the behavior and physiology that they express at maturity.

Budget impact analysis in Spanish patients with Dupuytren's contracture: fasciectomy vs. collagenase Clostridium histolyticum.

The aim of this study was to estimate the budget impact of collagenase Clostridium histolyticum (CCH) vs. fasciectomy (FSC) surgery for the treatment of Dupuytren's disease (DD) in Spain. A cost minimization analysis was adopted (effectiveness was assumed to be equivalent for both techniques). DD related costs were considered. CCH costs (including drug, administration and visits) were obtained from clinical trials and a real-life study. FSC costs (including type of admission, visits, operating room, re-admissions, tests, drugs and rehabilitation costs) were collected through a retrospective, observational, local study. Unit costs were obtained from local database systems (e-SALUD and BOT). Results were presented from the NHS perspective for the next 3 years. We assumed that there were 5100 fasciectomies per year (with a 5% annual increase) and that 20%, 30% and 40% of them will annually utilize CCH. In addition, a 10%, 15% and 20% of untreated diagnosed patients were expected to receive CCH. All the data were validated through an expert panel. A sensitivity analysis was performed with the main variables. The average FSC cost was €2250 (72% inpatients), €1703 for outpatients and €2467 for inpatients. The average CCH cost was €1220 (1.5 vial/injection and four visits) and could drop to €898 (1.1 vial/injections and three visits). The accumulated 3years budget impact analysis (BIA) was 45,971€ (K€-2993(1); 3870). According to this study, the inclusion of the CCH should produce a 3-year cumulative budgetary impact of €45,971 (K€-2993; 3870) for the NHS.

[Infant mortality in a third level paediatric hospital. therapeutic effort limitation, clinical-pathological agreement and diagnostic accuracy]. / Mortalidad infantil en un hospital de nivel terciario. Limitación de esfuerzo terapéutico, correspondencia clínico-patológica y precisión diagnóstica.

OBJECTIVE: To study infant and child mortality in a third level children's hospital treating highly complex patients. PATIENTS AND METHODS: All children dying in the period 2007- 2009 at La Paz Children's Hospital were evaluated. Epidemiological data, autopsy rate, clinical and autopsy diagnoses and their correspondence and the number of, patients with precise final diagnoses were analysed. Therapeutic effort limitation and palliative care were also evaluated as well as if the final result was expected according to the initial disease or clinical condition of the patients. All the variables were prospectively defined at the start of the study period. RESULTS: A total of 253 cases (6.08‰ admissions) were analysed. The two leading causes of death were disorders related to prematurity and low birth weight, and haematology oncology malignant diseases. Most patients (87%) died in an intensive care unit (neonatal or paediatric). During the study period 134 autopsies (53%) were performed, and new clinically significant findings were observed in 12 of these (7.8%) but in only one case the treatment could have possibly modified the prognosis (class I discrepancy). Therapeutic effort limitation and palliative care were implemented in 41.9%. Death was initially expected in 83.9% of cases. An accurate final diagnosis was defined in 92%, and the aetiology of the disease was considered to be identified in 86.4% of all deaths. CONCLUSIONS: Hospital mortality analysis is useful to evaluate the quality of the paediatric care and to detect adverse results that could be corrected. Paediatric autopsy continues to provide clinically significant data for paediatricians and families. Therapeutic effort limitation and palliative care is increasingly applied in paediatric end of life care. The number of infants and children dying without a final aetiological diagnosis is still considerably high.

Arthroscopic ligamentoplasty (bone-tendon-tenodesis). A new surgical technique for scapholunate instability: preliminary cadaver study.

We present an anatomical study and description of a new surgical technique for arthroscopic treatment of scapholunate ligament injuries. Five cadaver specimens were used to perform the technique. After arthroscopic surgery, anatomic dissection was performed to measure the distances to critical wrist structures such as the posterior interosseous nerve and the radial artery, and the size and position of the plasty. This arthroscopic technique offers three advantages: soft tissue damage is reduced (avoiding an extensive approach and injury to the secondary stabilizers and reducing scar tissue); injury to the posterior interosseous nerve is avoided (maintaining wrist proprioception and the role of the dynamic stabilizers); and a biotenodesis is made that ensures proper placement, tension and functionality of the flexor carpi radialis ligament reconstruction.

Maternal care counteracts behavioral effects of prenatal environmental stress in female rats.

There is extensive evidence in rats that prenatal environmental stress (PES) exposure and early postnatal altered maternal care, as a consequence of stress during gestation, can detrimentally affect the brain and behavioral development of the offspring. In order to separate the effect of PES on the fetuses from that on the behavior of the mother, in the present study, we used a cross-fostering procedure in which PES-fetuses were raised by non-stressed mothers and non PES-fetuses were raised by stressed mothers. In Experiment 1, non-stressed mothers showed significantly more maternal behavior than stressed mothers. In Experiment 2, when the female offspring from Experiment 1 reached maturity, they were tested for: (1) induced maternal behavior (MB), (2) plasma levels of corticosterone (Cpd B), progesterone (P), and estradiol (E(2)), (3) number of accessory olfactory bulb (AOB) mitral cells, and (4) c-fos expression measured in AOB and medial preoptic area (MPOA) neurons. We replicated our previous findings that the PES group reared by their own stressed mothers, when adult, attacked the young, expressed disorganized MB and showed altered Cpd B, P and E(2) levels, plus a male-like neuro-morphological pattern in the AOB, by comparison with the non-PES group, reared by their own non-stressed mothers. By contrast, when adult, the PES group reared by non-stressed mothers showed hormonal and morphological neuronal alterations, but they displayed appropriate (full) MB. The non-PES group raised by stressed mothers also showed altered hormone levels, but showed full MB and no morphological neuronal changes. Significant differences in the AOB and MPOA c-fos activity, related to whether or not MB was expressed, were found in the non-PES groups, but not in the PES group reared by non-stressed mothers. To our knowledge, this is the first study to document that adequate maternal care, early in development, can shape the subsequent expression of induced MB, overcoming neuro-morphological and hormonal alterations that are produced by prenatal environmental stress. We conclude that maternal care during early postnatal development can counteract detrimental effects of prenatal environmental stress, exerting long-lasting effects that modulate the behavioral phenotype of the offspring.

Environmental prenatal stress alters sexual dimorphism of maternal behavior in rats.

The prenatal external environment can affect fetuses, altering the maternal behavior that they express when mature. In the present study, environmental prenatal stress (EPS) was applied to pregnant rats in their final week of gestation, and when their female offspring reached maturity, the long latency effect of the stress on those offspring was ascertained on their induced maternal behavior (MB), accessory olfactory bulb (AOB) morphology and plasma levels of ACTH and corticosterone (Cpd B). EPS reduced: the percentage of these virgins that showed induced MB, their retrieval of foster pups, the time spent crouching, and the quality of nest building; it also increased the incidence of their cannibalism of foster pups. The EPS-treated females presented a male-like pattern of induced MB. They showed increased plasma levels of ACTH and Cpd B and increased numbers of mitral cells in the AOB. These findings provide evidence that stress applied to the pregnant rat produces long-lasting behavioral, neuroanatomical and hormonal alterations in the female offspring that can be observed when they reach maturity.

AT514, a cyclic depsipeptide from Serratia marcescens, induces apoptosis of B-chronic lymphocytic leukemia cells: interference with the Akt/NF-kappaB survival pathway.

Clinical treatment of B-cell chronic lymphocytic leukemia (B-CLL) is limited by the progressive drug resistance and nonselectivity of most drugs towards malignant cells. Depsipeptides are present in certain bacteria and display potent antitumor activity. We have studied the effect of the novel cyclodepsipeptide AT514 (serratamolide) from Serratia marcescens on B-CLL cell viability. AT514 induced apoptosis of B-CLL cells from the 21 patients studied, as confirmed by Annexin-V binding and nuclei condensation, with an average IC50 of 13 microM. AT514 was effective in those B-CLL cases resistant to fludarabine, but had no effect on normal PBL. AT514 preferentially activated the intrinsic apoptotic pathway, as evidenced by loss of mitochondrial membrane potential, release of cytochrome c and activation of caspase-9 and -3, but not of caspase-8. Importantly, AT514 interfered with phosphatidylinositol-3 kinase and protein kinase C survival signals since it increased the apoptotic effect of LY294002 and Bisl inhibitors, and induced Akt dephosphorylation at Ser 473. AT514 also decreased NF-kappaB activity by dramatically reducing the levels of p65 in B-CLL. This was confirmed on functional assays using NF-kappaB-luc-transfected Raji cells and transgenic mice. Our results establish that AT514 induces apoptosis of primary B-CLL cells and could be useful for clinical treatment of this malignancy.

Bicuculline infusion into the accessory olfactory bulb facilitates the induction of maternal behavior in rats.

The GABAA antagonist bicuculline, intracranially infused into the accessory olfactory bulb (AOB), facilitated the expression of maternal behavior (MB) in virgin Wistar female rats. Behavioral effects were observed 24 hours after infusion and were injection dependent. Pheromonal stimuli, generated by the pups, are thought to exert an inhibitory effect on vomeronasal nuclei involved in MB in virgin rats. The present study investigated the possibility that a decrement in AOB output, resulting from long-term compensatory synaptic changes to chronic bicuculline infusion, would facilitate the expression of MB. The implications of our findings for the mechanisms involved in the induction of MB and the maternal experience effect are discussed.