Experiences of first year undergraduate nursing students using Instagram in their clinical practicum during COVID-19 pandemic: A qualitative study

BACKGROUND

Social media provides us with easy access to information. For students, it is an additional learning resource used in different types of theoretical and practical teaching methodologies.

OBJECTIVES

The aim of this paper was to describe the perspective of undergraduate nursing students on the use of Instagram during their clinical practicums in the midst of the COVID-19 pandemic.

DESIGN

A qualitative descriptive and exploratory study based on an interpretative framework.

SETTINGS AND PARTICIPANTS

First-year undergraduate nursing students at the Universidad Europea de Madrid were included.

METHODS

In-depth interviews and researchers' field notes were used to collect the data. Purposive sampling and inductive thematic analysis were applied. During the interviews, themes such as accompaniment during practicums or training opportunities were identified.

RESULTS

The use of Instagram helped students to feel closer to professors, identifying it as an opportunity to remedy the possible lack of connection between theory and practice. Moreover, Instagram helped them build an image of nursing in clinical practicum environments. By using Instagram, undergraduate nursing students were able to better integrate and apply the knowledge acquired at university during their clinical practicums in hospitals.

CONCLUSIONS

Our results can be applied to future studies on the use of social media platforms as teaching tools in clinical practicum settings and to observe the evolution of the image and role of nursing and its relationship with social media.

Under-graduate nursing students working during the first outbreak of the COVID-19 pandemic: A qualitative study of psychosocial effects and coping strategies

BACKGROUND

The first wave of the COVID-19 pandemic caused a shortage of health care staff, forcing the hiring of senior nursing students.

AIMS

To describe the psychosocial impact and coping strategies used by nursing students during the first outbreak of the COVID-19 pandemic and to understand the coping strategies they employed.

METHOD

A qualitative exploratory study was conducted, based on Sandelowski's proposal. Purposive sampling was carried out to recruit 18 students hired during the pandemic. The students were interviewed between 18 March and 15 June 2020. Semi-structured interviews were conducted using a digital platform. An inductive thematic analysis was performed.

FINDINGS

The students lived alone and isolated during their contract to protect their cohabitants from possible contagion. The impact of working during the pandemic leads to experiences of stress, insomnia, nightmares and anxiety. Nursing students coped with the emotional burden through mental disconnection and the support of co-workers and family members.

CONCLUSION

Psychological support and tutoring should be provided by health centres. In addition, in these special circumstances, universities should adapt the training provided.

Ethical challenges during the COVID-19 pandemic: Perspectives of nursing students

BACKGROUND

The first wave of the COVID-19 pandemic caused a shortage of qualified nurses in Spain. As a result, the government authorized the hiring of senior students.

OBJECTIVES

To explore the ethical dilemmas and ethical conflicts experienced by final-year nursing students who worked during the first outbreak of the COVID-19 pandemic in Spain.

RESEARCH DESIGN

A qualitative exploratory study was conducted using purposive sampling. Semi-structured interviews were carried out using a question guide. Interviews took place via a private video chat room platform. A thematic, inductive analysis was performed of the information gathered.

PARTICIPANTS AND RESEARCH CONTEXT

Eighteen nursing students were recruited from two universities of Madrid, aged between 18 and 65 years old, enrolled in the fourth year of nursing studies and who were hired under a relief contract for health professionals during the pandemic.

ETHICAL CONSIDERATIONS

The present study was carried out in accordance with the Declaration of Helsinki, and the study was approved by the Local Ethics Committee of Universidad Rey Juan Carlos.

RESULTS

Three specific themes emerged: (a) coping with patient triage, (b) difficulties in providing end-of-life care, and (c) coping with patient death. Nursing students participated in the process of patient selection for resource allocation and ICU bed occupancy. They were shown how to care for patients who were not admitted to the ICU, in their last moments and were faced with the difficulties of applying end-of-life care. Finally, the nursing students were confronted with the death of their patients, in overwhelming numbers and under adverse conditions.

CONCLUSIONS

These findings can help shed light on the ethical dilemmas and ethical conflicts faced by novice nursing students, incorporated into the workforce during the COVID-19 pandemic. Moreover, it was described that students may normalize the death due to the exhaustion and overwhelmed routine.

Using a station within an objective structured clinical examination to assess interprofessional competence performance among undergraduate nursing students

AIM/OBJECTIVE

To describe and analyse the use of a station within an OSCE to assess interprofessional competence performance in undergraduate nursing students. The specific objectives were: - To measure the students' level of competence performance in relation to the interprofessional competences Roles and Responsibilities, Communication and Teamwork. - To determine inter-observer concordance in the assessment of the interprofessional competences.

BACKGROUND

Teamwork competencies are key to improving patient safety and avoiding medical errors. Today, healthcare professionals work in interdisciplinary teams. To foster a culture of safety, some of the measures that can be taken at the individual, team and organisational levels include fostering clear communication among team members, knowledge of respective roles and functions, and deepening team functioning through respect and trust in judgement and capabilities. The World Health Organization recommends starting to develop these competencies in university studies, through interprofessional education. There are numerous programmes in universities all over the world, but more research is needed on the assessment of interprofessional education activities, preferably through objective methods. Competency performance can be assessed by an external evaluator, in a simulated environment, with the Objective Structured Clinical Examination, which is widely used in nursing.

DESIGN

Cross-sectional study.

METHODS

63 second-year nursing undergraduate students completed an interprofessional competencies station within an 8-station OSCE. Communication, Roles and Responsibility and Teamwork competences were assessed. The Interprofessional Collaborator Assessment Rubric (ICAR) was used as a model to assess the performance of students. Inter-observer concordance analysis was performed using the kappa coefficient and the concordance rate.

RESULTS

92.1% of students reached a good level in communication competence, 88.9% in roles and responsibility competence, and 55.6% in teamwork competence. The global concordance rate was 83.8%, and the kappa coefficient was 0.67.

CONCLUSIONS

Most students have demonstrated interprofessional competence performance at a good level. However, the inter-observer concordance obtained for some of the items was not as expected. The assessment of interprofessional competencies, as it deals mainly with relational and communicative aspects, requires greater preparation both in terms of the specification of assessment items and in agreement between examiners.

The challenges of "learning on the go": A qualitative study of final-year Spanish nursing students incorporated to work during the first Covid-19 pandemic

BACKGROUND

The first wave of the COVID-19 pandemic caused a shortage of qualified nurses in Spain. As a result, the government authorized the hiring of senior students.

OBJECTIVES

To explore the perspectives of a group of final-year nursing students who were hired on the basis of a relief contract for health professionals during the first COVID-19 outbreak, regarding their learning process and their mixed role as students and novice nurses.

DESIGN

A qualitative exploratory study was conducted.

SETTINGS

The Nursing Department of the European University of Madrid, and the Red Cross College of Nursing.

PARTICIPANTS

Eighteen nursing students were recruited, aged between 18 and 65 years old, enrolled in the fourth year of Nursing Studies and who were hired under a relief contract for health professionals during the pandemic.

METHODS

Purposive sampling was used. Semi-structured, in-depth interviews were carried out using a question guide. Interviews were conducted in a private video chat room platform. Also, a thematic, inductive analysis was performed. This study was conducted according to the Consolidated Criteria for Reporting Qualitative Research and the Standards for Reporting Qualitative Research.

RESULTS

Four specific themes emerged: a) The students' role during the relief contract; b) The learning process during the pandemic; c) Barriers to learning; and d) A unique learning opportunity. The students had an undefined mixed role, which hindered their skills and activities. Learning was self-directed, sometimes through trial and error, and through experiencing critical events. Time constraints and having to learn under pressure were experienced as difficulties for learning. Nevertheless, this was a unique professional learning opportunity. The students learned to be organized and effective, acknowledge their limitations, gain confidence, face their fears, and mature.

CONCLUSIONS

These results can help inform nurse training programs and improve the organization and incorporation of nurses in health care facilities during the COVID-19 pandemic.

The effect of stereotypes and prejudices regarding gender roles on the relation between nurses and "Muslim fathers" in health institutions within the Community of Madrid (Spain)

Modern Western societies are characterized by a considerable cultural and ethnic diversity whereby different groups and minorities live side by side. However, not all people are viewed in the same light by the autochthonous population. This is particularly true in the case of Muslim immigrants, who are often prone to negative stereotyping and prejudice. This has become increasingly apparent since the 2001 terrorist attacks in New York and the subsequent attacks in various Western countries. This study seeks to analyze the relation between female nurses and those labeled by nurses as "Muslim fathers," as part of a research project on the care of immigrant children in Madrid (Spain). The findings promote reflection on the effects of nurses' stereotypes and prejudices regarding the gender roles of "Muslim fathers" and the relations between these groups. These prejudices can lead to situations of cultural imposition and/or discrimination. Self-reflection regarding stereotypes and prejudices is necessary in order to provide culturally competent care. The anthropobiological approach by Marie Françoise Collière may be useful for extending this type of care universally, not only to immigrant groups, as everyone, including nurses, patients, and family members, belong to part of a specific sociocultural context.

La Nueva Cadena de Suministro en la Era de los E-Retailers: Una Revisión Bibliográfica Actualizada

El crecimiento global del comercio electrónico continúa y las cadenas de suministro tradicionales se reinventan. A día de hoy, todavía no existe un marco que defina qué temas han sido los más presentes en la literatura sobre este aspecto. El objetivo de este artículo es ofrecer una recopilación bibliográfica actualizada sobre las implicaciones de este nuevo canal de ventas en la cadena de suministro, con una visión centrada en la figura de los e-retailers. En este marco, analizamos tanto los modelos de venta que se centran únicamente en el mercado online (puros e-retailers), como los que desarrollan una estrategia multicanal.

Increased expression with differential subcellular location of cytidine deaminase APOBEC3G in human CD4(+) T-cell activation and dendritic cell maturation

APOBEC3G (apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3G; A3G) is an innate defense protein showing activity against retroviruses and retrotransposons. Activated CD4(+) T cells are highly permissive for HIV-1 replication, whereas resting CD4(+) T cells are refractory. Dendritic cells (DCs), especially mature DCs, are also refractory. We investigated whether these differences could be related to a differential A3G expression and/or subcellular distribution. We found that A3G mRNA and protein expression is very low in resting CD4(+) T cells and immature DCs, but increases strongly following T-cell activation and DC maturation. The Apo-7 anti-A3G monoclonal antibody (mAb), which was specifically developed, confirmed these differences at the protein level and disclosed that A3G is mainly cytoplasmic in resting CD4(+) T cells and immature DCs. Nevertheless, A3G translocates to the nucleus in activated-proliferating CD4(+) T cells, yet remaining cytoplasmic in matured DCs, a finding confirmed by immunoblotting analysis of cytoplasmic and nuclear fractions. Apo-7 mAb was able to immunoprecipitate endogenous A3G allowing to detect complexes with numerous proteins in activated-proliferating but not in resting CD4(+) T cells. The results show for the first time the nuclear translocation of A3G in activated-proliferating CD4(+) T cells.

[Interferon-alpha toxicity and reversible bilateral optical neuropathy: a timely withdrawal of the drug]

Clinical case A patient with chronic, painless, bilateral loss of vision, after significant intake of interferon (IFNα) and ribavirina due to liver transplant. Ocular fundus is normal. A suspected retrobulbar optic neuropathy is confirmed by a prolongation of the latency of the patient's visual evoked potential. There being no prior record of risk factors and with the patient's systemic analysis giving normal results, the clinical improvement and the electro-physiological tests conducted after the drug was withdrawn point to interferon as negatively affecting the bilateral optic nerve. Discussion Interferon-α is used in the treatment of viral and neoplastic illnesses. Currently the drug is formulated as Interferon alfa pegilado (IFNα-p) in order to reduce toxicity and increase tolerance. The most common secondary effects are flu symptoms, asthenia and weigh loss. Affected ocular tissue is rare and optic neuropathy is also an infrequent complication: retinopathy at the beginning of treatment is, however, more frequent. The most widely accepted hypothesis as to the cause of toxicity is the presence of circulating immune complexes. It is, therefore, essential for ophthalmologists to be aware of the toxicity of this drug in order to be able to withdraw it in good time, thus preventing potentially irreversible sight loss.

Expression of PD-L1 and PD-L2 on human macrophages is up-regulated by HIV-1 and differentially modulated by IL-10

PD-1 plays an important role in T cell exhaustion during HIV infection. PD-1 has two ligands: PD-L1, expressed on hematopoietic and nonhematopoietic cells, and PD-L2, limited to DCs and macrophages. Little is known about PD-L1 expression and regulation in human macrophages. Previous reports have found few immediate effects of macrophage exposure to HIV, suggesting that macrophages lack PRRs for this virus. Using quantitative confocal microscopy and a multiplexed cytokine bead array, we measured induction of PD-L1, PD-L2, and innate response cytokines in human MDMs in response to chemically inactivated HIV virions. Consistent with previous reports, no cytokines were induced by HIV virion exposure. Whereas PD-L1 and PD-L2 had low baseline expression, TLR ligands (LPS and CL097) up-regulated PD-L1 but not PD-L2. Unlike what we found for cytokine expression, PD-L1 and PD-L2 were up-regulated in response to exposure with inactivated HIV virions or with replication-competent HIV. Expression of PD-L1 was differentially modulated by IL-10, which induced up-regulation of PD-L1 but not of PD-L2, and IL-10 blockade enhanced only PD-L2 expression. We discuss implications for innate recognition of HIV by macrophages and potential, different roles for PD-L1 and PD-L2 in immunity and pathogenesis.

Peripheral blood cytokine profiling during pregnancy and post-partum periods

PROBLEM

Pregnancy requires that the maternal immune system adapt to prevent rejection of the fetal semi-allograft. This immunologic adaptation may contribute to pregnancy-related alterations in disease susceptibility and severity of infections from viral pathogens such as influenza virus.

METHOD OF STUDY

As part of a larger study investigating the maternal systemic immune response during pregnancy, peripheral blood was collected three times during pregnancy and twice post-partum to measure serum levels of 23 cytokines, chemokines, and growth factors. This longitudinal study design allowed each woman's post-partum blood draw to serve as her own comparison, thus controlling for interpersonal variability in expression levels.

RESULTS

When compared to the post-partum samples, significant pregnancy-related changes in IFNγ, TNFα, VEGF, GCSF, Eotaxin, and MCP-1 expression were observed. These changes have significant immunologic effects in vivo and in culture.

CONCLUSION

Pregnancy-associated changes to steady state serum cytokines may have important immunologic consequence.

Increased alpha-defensins 1-3 production by dendritic cells in HIV-infected individuals is associated with slower disease progression

Background

Defensins are natural endogenous antimicrobial peptides with potent anti-HIV activity and immuno-modulatory effects. We recently demonstrated that immature dendritic cells (DC) produce α-defensins1-3 and that α-defensins1-3 modulate DC generation and maturation. Since DC-HIV interaction plays a critical role during the first steps of HIV infection, we investigated the possible impact of α-defensins1-3 production by DC on disease progression.

Methodology/Principal Findings

Monocyte-derived DC (MDDC) were analyzed comparatively in healthy controls (HC) and HIV-infected patients, including untreated “elite” and “viremic” controllers, untreated viremic non-controllers and antiretroviral-treated patients. We found that production of α-defensins1-3 was significantly increased in MDDC from HIV-infected patients versus HC, and this increase was mainly due to that observed in controllers, while in non-controllers the increase was not statistically significant (controllers vs. HC, p<0.005; controllers vs. non-controllers p<0.05). Secreted α-defensins1-3 by immature MDDC positively correlated with CD4 T cell counts in controllers, but not in non-controllers. Moreover, independently of their clinical classification, HIV-infected patients with higher α-defensins1-3 secretion by immature MDDC showed slower disease progression, measured as no decrease in the number of CD4+ T-cells below 350 cell/mm³, lower increase of plasma viral load and no initiation of treatment over time. Plasma alpha-defensins1-3 levels lacked any relationship with immunologic and virologic parameters.

Conclusions/Significance

High production of α-defensins1-3 by immature DCs appears as a host protective factor against progression of HIV-1infection, suggesting potential diagnostic, therapeutic and preventive implications. This protective effect may arise from the activity of α-defensins1-3 to damage the virions prior and/or after their internalization by immature DC, and hence favoring a more efficient viral processing and presentation to HIV-specific CD4+ T cells, without or with a minor rate of transmission of infectious HIV-1 virions.

Impact of alpha-defensins1-3 on the maturation and differentiation of human monocyte-derived DCs. Concentration-dependent opposite dual effects

alpha-defensins1-3 are potent antimicrobial molecules that also link innate and adaptive immunity, depending on the concentration range. However, their effects on the biology of human DCs remain largely unknown. We analyzed the impact of different concentrations of alpha-defensins1-3 on the maturation and differentiation of monocyte-derived DCs (MDDCs). Low doses of alpha-defensins1-3 up-regulated CD83, CD86 and HLA-DR expression, increased TNF-alpha, IL-1beta, IL-12p40, IL-10 and IL-8 secretion, and slightly augmented allostimulatory capacity. By contrast, high doses down-regulated CD86 and HLA-DR expression, TNF-alpha, IL-1beta, IL-12p40 and IL-10 secretion and allostimulatory capacity, whereas strongly up-regulated IL-8. Furthermore, during the MDDC differentiation process, high doses of alpha-defensins1-3 affected CD14, CD11c and CD86 expression and strongly up-regulated IL-8. Results suggest that alpha-defensins1-3 might modulate the maturation and differentiation of MDDCs in vivo and therefore could be of special interest in the field of vaccine development.

Progression of vascular calcifications is associated with greater bone loss and increased bone fractures

In this prospective study, we found a positive relationship between the prevalence of aortic calcifications and age. Aortic calcifications at baseline were positively associated with osteoporotic fractures. In addition, progression of aortic calcifications was also positively associated with the rate of decline in BMD at lumbar spine.

INTRODUCTION

The aim of this study was to analyze the relationship between the progression of abdominal aortic calcification and osteoporosis in a Spanish cohort of men and women older than 50.

METHODS

Men and women (n=624) aged 50 and over underwent two lateral X-rays of thoracic and lumbar spine and a dual X-ray absorptiometry (DXA) study at lumbar spine and hip, and were followed during 4 years. Abdominal aortic calcifications were classified as absent, mild-moderate and severe.

RESULTS

There was a positive relationship between the prevalence of aortic calcifications and age. In both sexes, prevalent severe aortic calcifications were positively associated with prevalent osteoporotic fractures [odds ratio (OR)=1.93 (1.02-3.65)]. The association was stronger when only vertebral fracture was considered [OR=2.45 (1.23-4.87)]. In addition, progression of aortic calcifications showed a positive association with the rate of decline in bone mineral density (BMD) at lumbar spine.

CONCLUSIONS

Aortic calcifications at baseline were positively associated with osteoporotic fractures. The progression of aortic calcifications was also positively associated with the rate of decline in BMD at lumbar spine.

The rheumatoid arthritis-associated allele HLA-DR10 (DRB1*1001) shares part of its repertoire with HLA-DR1 (DRB1*0101) and HLA-DR4 (DRB*0401)

OBJECTIVE

To identify the peptide anchor motif for the rheumatoid arthritis (RA)-related HLA allele, DR10, and find shared natural ligands or sequence similarities with the other disease-associated alleles, DR1 and DR4.

METHODS

The HLA-DR10-associated peptides were purified, and a proportion of these natural ligands were de novo sequenced by mass spectrometry. Based on crystallographic structures, the complexes formed by peptide influenza virus hemagglutinin HA306-318 with DR1, DR4, and DR10 were modeled, and binding scores were obtained.

RESULTS

A total of 238 peptides were sequenced, and the anchor motif of the HLA-DR10 peptide repertoire was defined. A large proportion of the DR10-associated peptides had the structural features to bind DR1 and DR4 but were theoretical nonbinders to the negatively associated alleles DR15 and DR7. Among the sequenced ligands, 10 had been reported as ligands to other RA-associated alleles. Modeling data showed that peptide HA306-318 can bind DR1, DR4, and DR10 with similar affinities.

CONCLUSION

The data show the presence of common peptides in the repertoires of RA-associated HLA alleles. The combination of the shared epitope present in DR1, DR4, and DR10 together with common putative arthritogenic peptide(s) could influence disease onset or outcome.

Human immature monocyte-derived dendritic cells produce and secrete α-defensins 1-3

Defensins are effector molecules of the innate immunity with a broad antimicrobial spectrum, including HIV. They also link innate and adaptive immunity, displaying chemotactic activity for monocytes, T cells, and dendritic cells (DCs). alpha-Defensins 1-3 are mainly produced by neutrophils, but their production by other leukocyte subsets has also been reported. Herein, we studied whether monocyte-derived DCs (MDDCs), which are regarded as a model for myeloid DCs, produce alpha-defensins 1-3. We found that immature MDDCs (imMDDCs) produce alpha-defensins 1-3 mRNA, but this production is undetectable or barely detectable following 48 h of maturation with the proinflammatory cytokine cocktail (IL-1beta+IL-6+TNF-alpha) or LPS. It is surprising that alpha-defensins 1-3 production was up-regulated when exposed to each one of the proinflammatory cytokines alone, especially IL-1beta. alpha-Defensins 1-3 produced by imMDDCs were mainly secreted peptides. Production and secretion of alpha-defensins 1-3 by imMDDCs can have biological relevance for the antigen processing of pathogens and can contribute to understanding differences in susceptibility to infections, an issue of special interest in the field of HIV infection.

A novel mutation in the calcium-sensing receptor responsible for autosomal dominant hypocalcemia in a family with two uncommon parathyroid hormone polymorphisms

A novel missense activating mutation in the extracellular calcium-sensing receptor (CaSR) is reported in this work. It was identified in three related subjects with the phenotypic features of autosomal dominant hypocalcemia (ADH). The proband, a 27-year-old woman, diagnosed as having hypoparathyroidism at 7 years of age and a history of seizures, showed the highest penetrance of the mutation. The remaining two affected members presented asymptomatic chronic hypocalcemia despite severe hypoparathyroidism associated with high levels of serum phosphate and calcium urinary excretion. The missense mutation (Glu(604)Lys) affected an amino acid residue in the C terminus of the cysteine-rich domain of the extracellular amino-terminal domain, which seems to be required for the coupling of ligand binding to the activation of intracellular signaling pathways. This genetic change cosegregated with hypocalcemia in all the individuals where the mutation was found. As parathyroid hormone (PTH) secretion is the regulatory target of the CaSR, polymorphism analysis of the PTH gene was carried out. PTH polymorphisms were analyzed in the kindred studied. Affected members for the Glu(604)Lys CaSR mutation which also carried the uncommon PTH alleles showed higher penetrance of the mutation, with more severe autosomal dominant hypocalcemia. These results suggested that the PTH gene could act as a modifier locus of ADH, affecting the penetrance of the activating CaSR mutation described.

The effect of vertebral fracture as a risk factor for osteoporotic fracture and mortality in a Spanish population

There is little data concerning the morbidity, mortality, and epidemiology of vertebral fracture. The aim of this study was to evaluate the effect of prevalent and incident vertebral fractures as risk factors for further osteoporotic fractures and mortality. The study was performed on a cohort of 316 women and 308 men older than 50 belonging to the EVOS study, randomly selected from our city register. At the beginning of the study and 4 years later, lateral dorsal and lumbar X-rays were performed. In addition, evaluation of the incidence of osteoporotic nonvertebral fractures was performed throughout 8 years. The incidence of all osteoporotic fractures was higher in women than in men (two-fold increase in vertebral fracture incidence and five-fold increase in Colles' and femur incidence). Vertebral fracture was a strong risk factor for a new vertebral fracture [RR=4.7 (1.8-11.9)], hip fracture [RR=6.7 (2.0-22.7)] and Colles' fracture [RR=3.0 (1.1-7.8)]. Prevalent and incident vertebral fractures were associated with a higher risk of having a hip fracture [RR=10.0 (2.0-50.2)] and Colles' fracture [RR=5.5 (1.3-23.4)]. In addition, in women, the vertebral fracture was associated with a higher mortality. By contrast, no association was found in men. These results demonstrate the association between a previous vertebral fracture with increments in the incidence of osteoporotic fractures of any type. In addition, we found a significantly higher mortality rate in women having vertebral fractures. These findings support the necessity of preventing the occurrence of vertebral fractures to limit their strong negative impact on mortality.

Effect of perinatal hypothyroidism on the developmental regulation of rat pituitary growth hormone and thyrotropin genes

We studied the effects of thyroid hormone (T3) on GH, TSH, and T3 receptor (TR) gene expression as well as deiodinase activities during rat pituitary development. By reverse transcriptase-polymerase chain reaction, GH and TSH beta transcripts were detectable on fetal day 15. Although with certain differences, the expression of both GH and TSH beta genes was under T3 control during fetal and neonatal life. Differences in plasma, but not pituitary, TSH concentrations were observed between control and hypothyroid animals throughout the period studied. Both TR alpha and TR beta genes were expressed in the fetal pituitary. TR alpha 1, TR beta 2, and c-erbA alpha 2 transcripts displayed a developmental profile different from that of TR beta 1. Thyroid hormone repressed TR alpha 1, TR beta 2, and c-erbA alpha 2 and stimulated TR beta 1. Type I and type II deiodinase activities (5'DI and 5'DII, respectively) had different ontogenic patterns; 5'D-II was the predominant activity in fetuses, with levels similar to those in adults, whereas the level of 5'D-I was low and increased with age. T3 stimulated 5'D-I and decreases 5'D-II. These results demonstrate that in somatotroph and thyrotroph cells, the mechanisms responsible for T3 action are mature and active very early in development and suggest an involvement of this hormone in the establishment and/or maintenance of the somatotroph and thyrotroph phenotype.