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Space coding affects perception of stimuli associated to negative valence: threatening stimuli presented within the peripersonal space (PPS) speed up behavioral responses compared with nonthreatening events. However, it remains unclear whether the association between stimuli and their negative valence is acquired in a body part-centered reference system, a main feature of the PPS coding. Here we test the hypothesis that associative learning takes place in hand-centered coordinates and can therefore remap according to hand displacement. In two experiments, we used a Pavlovian fear-learning paradigm to associate a visual stimulus [light circle, the conditioned stimulus (CS)] with an aversive stimulus (electrocutaneous shock) applied on the right hand only when the CS was displayed close (CS+) but when not far from it (CS-). Measuring the skin conductance response (SCR), we observed successful fear conditioning, with increased anticipatory fear responses associated with CS+. Crucially, experiment I showed a remapping of these responses following hand displacement, with a generalization to both types of CS. Experiment II corroborated and further extended our findings by ruling out the novelty of the experimental context as a driving factor of such modulations. Indeed, fear responses were present only for stimuli within the PPS but not for new stimuli displayed outside the PPS. By revealing a hand-centered (re)mapping of the conditioning effect, these findings indicate that associative learning can arise in hand-centered coordinates. They further suggest that the threatening valence of an object also depends on its basic spatial relationship with our body.NEW & NOTEWORTHY Associative fear learning takes place in hand-centered coordinates. Using a Pavlovian fear-learning paradigm, we show that the anticipatory skin conductance response indicating the association between the negative value and an initially neutral stimulus is acquired and then remapped in space when the stimulated body part moves to a different position. These results demonstrate the relationship between the representation of peripersonal space and the encoding of threatening stimuli. Hypotheses concerning the underlying neural network are discussed.
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Aprendizaje por Asociación , Miedo , Mano/fisiología , Espacio Personal , Aprendizaje Espacial , Adulto , Condicionamiento Clásico , Femenino , Humanos , Masculino , MovimientoRESUMEN
BACKGROUND: The precise burden of paediatric surgical care in South Africa is unknown. In the absence of epidemiological data, hospital-based study is a first step to gauge the burden and profile of paediatric surgical disease. We aim to describe the profile of pathology, pattern of referrals, and complications of paediatric surgical care at Chris Hani Baragwanath Academic Hospital (CHBAH). METHODS: A 1-year retrospective record review for the period 3/1/2019 to 1/1/2020 was conducted by evaluation of the morbidity and mortality databases of the Department of Paediatric Surgery (DPS). Number of admissions, consultations, complications, and surgeries performed were analysed and classified. RESULTS: A total of 11,932 unique patient encounters occurred. Emergencies (79%, 1841/2329) accounted for the majority of admissions. Trauma accounted for 49% (896/1841) of emergency admissions. Elective surgery constituted 52% (1202/2316) and emergency surgery 48% (1114/2316) of all procedures performed. The emergency department (55%, 1271/2329), outpatients department (19%, 447/2329), and peripheral hospitals (16%, 378/2329) were the source of the majority of admissions. A complication rate of 9% (208/2316) was observed. CONCLUSION: The high-volume subspecialist environment at CHBAH presents the ideal environment for delivery of specialist paediatric surgical services and training. Injury prevention, optimal use of existing resources, and additional physical, human and financial resources are required to meet the existing and predicted future burden of paediatric surgical disease.
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Costo de Enfermedad , Servicio de Urgencia en Hospital , Niño , Urgencias Médicas , Humanos , Estudios Retrospectivos , Sudáfrica/epidemiologíaRESUMEN
We report an extremely rare case of extrarenal testicular Wilms' tumor in a 3-year-old boy with intrabdominal undescended left testis. The patient was admitted because of pain and vomiting, with evidence of a huge abdominal mass. At surgery a large tumor arising from the intrabdominal testis was found. Histology showed the classical triphasic Wilms' tumor elements: epithelial, mesenchymal and blastemal areas. Extrarenal Wilms' tumors account for only 3% of all Wilms' tumors and just -100 cases have been reported in literature. Testicular origin is anecdotic. We present histomorphological, histogenetic, clinical, diagnostic, prognostic and therapeutic features of this rare tumor.
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Neoplasias Testiculares/cirugía , Tumor de Wilms/cirugía , Preescolar , Medios de Contraste , Estudios de Seguimiento , Humanos , Masculino , Intensificación de Imagen Radiográfica/métodos , Neoplasias Testiculares/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Ultrasonografía Doppler/métodos , Tumor de Wilms/diagnóstico por imagenRESUMEN
BACKGROUND: After the implementation of a population-based programme of chest x-ray (CXR) screening on smokers in Varese, Italy, lung cancer (LC) mortality was significantly reduced. Analysis of the incremental costs due to this type of screening programme is needed to evaluate its economic impact on the healthcare system. METHODS: In July 1997 a population-based cohort, consisting of all high-risk smokers (n=5,815) identified among 60,000 adult residents from the Varese province, was invited to a LC screening programme (an annual CXR for five years) in a general practice setting, and was observed through 2006. Invitees received National Health Service (NHS) usual care, with the addition of CXRs in screening participants. At the end of observation, among the 245 LCs diagnosed in the entire screening-invited cohort the observed LC deaths were 38 fewer than expected. To estimate the incremental direct cost due to screening in the invited cohort for the period July 1997-2006, we compared the direct cost of screening administration, CXR screens and LC management in the invited cohort and in the uninvited and unscreened controls in NHS usual care setting. RESULTS: Over the 9.5 years, the total incremental direct healthcare costs (including screening organization/administration, CXR screens, additional procedures prompted by false-positive tests, overdiagnosed LCs) were estimated to range from euro 607,440 to euro 618,370 (in euros as of 2012), equating to between euro 15,985- euro 16,273 per patient out of the 38 LC deaths averted. CONCLUSIONS: In a general practice setting, the incremental cost for a CXR screening programme targeted at all high-risk smokers in a population of 60,000 adults was estimated to be about euro 65,000 per annum, approx. euro 16,000 for each LC death averted.
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Neoplasias Pulmonares/diagnóstico por imagen , Tamizaje Masivo/economía , Radiografía Torácica/economía , Adulto , Costos y Análisis de Costo , Estudios de Seguimiento , Humanos , Italia/epidemiología , Neoplasias Pulmonares/epidemiología , Tamizaje Masivo/métodos , Morbilidad/tendencias , Estudios RetrospectivosRESUMEN
BACKGROUND: Factors that directly or indirectly influence nurses' decisions regarding aspects of in-hospital care are well-known. On the other hand, little is known about which elements/criteria are used by home-care nurses to make decisions about the frequency of follow-up visits. OBJECTIVES: The objective of this study was to identify the criteria used for defining the frequency of follow-up visits in patients with heart failure. METHODS: Different study methods were used. A cross-sectional questionnaire study was performed to identify what specific aspects are considered for deciding to provide homecare to patients with heart failure. Three focus groups were then held with homecare nurses with experience with heart failure patients, to discuss and reach a consensus regarding the criteria for frequency of follow-up visits. RESULTS: The criteria that guide decision-making about the frequency of follow-up home visits are: a) clinical condition of the patient, b) presence of a caregiver, c) compliance/adherence to drug therapy, d) characteristics of the patient, e) workload, f) professional experience of the healthcare operator, f) assessment by the patient's general practitioner. CONCLUSIONS: The study identified which factors influence home-care nurses' decision-making in defining the frequency of follow-up for patients with heart failure. The decision-making process is based on the evaluation of multiple factors and also considers the organizational context in which home-care nurses work and their workload. Accurate criteria need to be defined.
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Insuficiencia Cardíaca/enfermería , Servicios de Atención de Salud a Domicilio/estadística & datos numéricos , Estudios Transversales , Femenino , Estudios de Seguimiento , Humanos , Masculino , Encuestas y CuestionariosRESUMEN
OBJECTIVES: The primary aim of the study was to explore pain intensity (PI) and pain coping (PC) scores and the relationship between them. The secondary aim was to explore the correlation between PI and PC scores with labour progress, parity, labour acceleration, labour augmentation and maternal satisfaction. METHODS: A prospective descriptive correlational study was conducted in a maternity hospital in Northern Italy. The sample included 54 low-risk women in active labour at term of pregnancy. A data record sheet was used to collect the relevant variables and the Italian Birth Satisfaction Scale Revised (I-BSS-R) was administered to participants at least 24 h after birth. RESULTS: In the first labour stage, the average PI score was 6.99 (SD = 1.95) and the average PC score was 6.5 (SD = 2.22). During the second labour stage, the average PI score was 7.75 (SD = 1.74) and the average PC score was 4.97 (SD = 2.76). The average PI score trend increased with labour progress. The average PC score improved between 4 and 7 cm of cervical dilatation. A significant positive correlation between PI scores and oxytocin augmentation (p < 0.001) and labour progression (p < 0.001) was noted. A significant positive correlation between PC scores and oxytocin augmentation (p = 0.02) was also observed. No significant differences were found for maternal satisfaction in regard to PI and PC scores. CONCLUSION: coping in labour do not solely depend on PI but also on labour progress and oxytocin augmentation. Additional support to empower women to cope with pain may be required in case of labour augmentation.
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Segundo Periodo del Trabajo de Parto , Oxitocina , Embarazo , Femenino , Humanos , Dimensión del Dolor , Adaptación Psicológica , Dolor , Satisfacción PersonalRESUMEN
Sputum induction can be used as a non-invasive technique to investigate airway inflammation in asthma and COPD. We reported the case of a 68 year old man with COPD, stage III GOLD, that underwent sputum induction during two exacerbation episodes. The first cell count showed a typical sputum neutrophilia, whereas the second showed sputum eosinophilia. On the basis of sputum cellularity, we decided to treat the first episode with a course of antibiotics and the second exacerbation with a course of antibiotics and oral steroids. The patient showed improvement in both cases, obtaining clinical stabilisation. The induced sputum cell count could be a useful technique in a clinical setting to evaluate the cellular characteristics of airway inflammation during COPD exacerbation and modulate the antinflammatory therapy.
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Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Esputo/citología , Anciano , Recuento de Células , Volumen Espiratorio Forzado , Humanos , Masculino , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Enfermedad Pulmonar Obstructiva Crónica/terapiaRESUMEN
Thymolipoma is a rare benign anterior mediastinal tumour of thymic origin containing both thymic and mature adipose tissues. In most cases it has a silent course and can grow to large sizes before presenting with respiratory symptoms. We report a case of a giant thymolipoma in a 4-year-old girl treated at Chris Hani Baragwanath Academic Hospital, South Africa.
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Two approaches of an automatic control were studied through mathematical fitting obtained from color mixing saturation curves in polydimethylsiloxane microfluidic devices: The integrative control with variable integral gain and integrative control with constant integral gain. The aim of this work is to control the color percentage decrement when dye is injected. The results indicate that microfluidic systems are very sensitive to changes in flow and the control variable needs to change slowly; that is, it must be small (at least 100 times less than the theoretically calculated values). The control and stabilization of the microfluidic system were achieved for dye percentages above 60%. The controlling color percentage could provide a tool to regulate other parameters' concentration applied to cell culture and alkalinity control (pH) of solutions in microfluidic devices.
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Peripersonal space (PPS) is a multisensory representation of the space near body parts facilitating interactions with the close environment. Studies on non-human and human primates agree in showing that PPS is a body part-centered representation that guides actions. Because of these characteristics, growing confusion surrounds peripersonal and arm-reaching space (ARS), that is the space one's arm can reach. Despite neuroanatomical evidence favoring their distinction, no study has contrasted directly their respective extent and behavioral features. Here, in five experiments (N = 140) we found that PPS differs from ARS, as evidenced both by participants' spatial and temporal performance and by its modeling. We mapped PPS and ARS using both their respective gold standard tasks and a novel multisensory facilitation paradigm. Results show that: (1) PPS is smaller than ARS; (2) multivariate analyses of spatial patterns of multisensory facilitation predict participants' hand locations within ARS; and (3) the multisensory facilitation map shifts isomorphically following hand positions, revealing hand-centered coding of PPS, therefore pointing to a functional similarity to the receptive fields of monkeys' multisensory neurons. A control experiment further corroborated these results and additionally ruled out the orienting of attention as the driving mechanism for the increased multisensory facilitation near the hand. In sharp contrast, ARS mapping results in a larger spatial extent, with undistinguishable patterns across hand positions, cross-validating the conclusion that PPS and ARS are distinct spatial representations. These findings show a need for refinement of theoretical models of PPS, which is relevant to constructs as diverse as self-representation, social interpersonal distance, and motor control.
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Espacio Personal , Percepción Espacial , Imagen Corporal , Mano , NeuronasRESUMEN
Radiation assessment and protection in space is the first step in planning future missions to the Moon and Mars, where mission and number of space travelers will increase and the protection of the geomagnetic shielding against the cosmic radiation will be absent. In this framework, the shielding effectiveness of two flexible materials, Kevlar and Nextel, were tested, which are largely used in the construction of spacecrafts. Accelerator-based tests clearly demonstrated that Kevlar is an excellent shield for heavy ions, close to polyethylene, whereas Nextel shows poor shielding characteristics. Measurements on flight performed onboard of the International Space Station and of the Foton-M3 capsule have been carried out with special attention to the neutron component; shielded and unshielded detectors (thermoluminescence dosemeters, bubble detectors) were exposed to a real radiation environment to test the shielding properties of the materials under study. The results indicate no significant effects of shielding, suggesting that thin shields in low-Earth Orbit have little effect on absorbed dose.
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Internacionalidad , Protección Radiológica/instrumentación , Vuelo Espacial , RadiometríaRESUMEN
Aim of the study was to investigate the lifestyles of nursing students attending the first year at an Italian school of nursing, before their knowledge of health promotion and health education can condition their behaviour. Research suggests that nurses themselves, in both the acute and primary care settings, perceive that health education is an important part of their role. The study consisted of a self-administered questionnaire with five sections: general data, and questions on nutrition, physical activity, smoking behaviour and alcohol. Response rate was 89.2% (149/167): 87.2% of respondents reported they were satisfied with their health status; 70.5% of students had a normal body mass index; 40.6% of males and 23.1% of females played a sport; 49.7% had never smoked in their life; 50.3% had smoked at least once; 62.7% were smokers and 75.2% of students had drunk alcohol at least once. The students surveyed adopt unhealthy behaviours like smoking, use of alcohol and poor physical activity even if they consider they are in good health. The study stresses the fact that the nursing population needs to be specifically trained to make positive changes. This is important for their education and also for their position as role models for patients they will care for in the future.
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Conductas Relacionadas con la Salud , Estilo de Vida , Estudiantes de Enfermería , Adulto , Femenino , Humanos , Italia , Masculino , Encuestas y Cuestionarios , Adulto JovenRESUMEN
This study examines the socio-demographic characteristics of first-year students on first degree healthcare courses at Udine University (Italy). The survey tried to elicit useful information in a field where literature is scarce. Every student starting healthcare courses in the 2007/08 academic year was contacted and asked to fill in a questionnaire. Two hundred and sixty students were identified, belonging to six different courses: Nursing Sciences, Obstetric Sciences, Physiotherapy, Radiography, Neurophysiopathology Techniques, Biomedical Laboratory Techniques. Each questionnaire included 26 items (25 closed and one open) and had four sections: personal data, family data, training background, criteria affecting the decision to attend a healthcare course. The overall response rate was 87% (226 out of 260). Major findings were: women prevail on men (77% vs. 23%), many students chose these courses because some family member worked in the healthcare field (22.1%), 19.9% of students are older than 26 and 7.1% of them are postgraduates, 12% come from foreign countries, and job opportunities and former work experience influenced the choice of course. This database provides an important benchmark for comparing future trends among students in the healthcare profession in terms of socio-demographic characteristics and personal attitudes.
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Empleos en Salud/educación , Estudiantes , Adolescente , Adulto , Femenino , Humanos , Italia , Masculino , Factores Socioeconómicos , Encuestas y Cuestionarios , Universidades , Adulto JovenRESUMEN
The past decade has been seen widespread use of telephone and computer technologies to provide a broad array of health behaviours intervention and health services. The purpose of this study is to explore the frequency and the reasons about telephone using in an Italian Day Hospital oncological ward. The study was conducted in 2008 throughout a questionnaire filled by nurses that receive patients telephone calls. We analyzed 100 hours of nurses' work corresponding to about 13 days. The mean of daily calls was 30.5 (SD=6.4). 72.2% were calls effectuated on the morning, the others in the afternoon. Nurses spent 13% of their shiftwork time on telephone: 6.97 hours for calls regards directly patients and 5.8 hours for service calls. General information and information on tests results were the more frequent motivations of patients' calls. The study stress major workload for nurses in telephone answers. A significant patient demand emerged that should be addressed also identifying specific hours during the day.
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Centros de Día/estadística & datos numéricos , Neoplasias , Teléfono/estadística & datos numéricos , Humanos , Italia , Neoplasias/terapiaRESUMEN
BACKGROUND: Only a few studies have evaluated microvascular changes and proangiogenetic mediators in the bronchial mucosa of patients with chronic obstructive pulmonary disease (COPD), and the results have been discordant. Furthermore, the role of inhaled corticosteroids (ICS) in COPD has not been extensively studied. A study was undertaken to evaluate vascular remodelling, its relationship with inflammatory cells and treatment effects in the bronchial mucosa of patients with COPD. METHODS: The study comprised three groups: (1) 10 non-treated patients with COPD (COPD); (2) 10 patients with COPD treated with nebulised beclomethasone dipropionate 1600-2400 mug daily (equivalent to 800-1200 mug via metered dose inhaler) (COPD/ICS); and (3) 8 control subjects (CS). Bronchial biopsies were evaluated for number and size of vessels and vascular area. Specimens were also examined for vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and transforming growth factor beta (TGF-beta) expression and inflammatory cell counts were performed. RESULTS: Vascular area, vessel size, VEGF+ cells, bFGF+ cells and TGF-beta+ cells were significantly increased in the COPD group compared with the COPD/ICS and CS groups (all p<0.05). In addition, bFGF+ cells were significantly increased in the COPD/ICS group compared with the CS group, and CD8+ and CD68+ cells were significantly increased in the COPD group compared with the COPD/ICS and CS groups (p<0.05). In the COPD group the VEGF+ cells correlated with the number of vessels (p<0.05), vascular area (p<0.01) and vessel size (p<0.05), and TGF-beta+ cells correlated significantly with vascular area (p<0.05). CONCLUSION: Bronchial vascular remodelling in patients with COPD is mainly related to morphological changes of the mucosal microvessels rather than to new vessel formation, and may be reduced in patients treated with steroids.
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Remodelación de las Vías Aéreas (Respiratorias)/fisiología , Bronquios/irrigación sanguínea , Glucocorticoides/farmacología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Administración por Inhalación , Anciano , Anciano de 80 o más Años , Remodelación de las Vías Aéreas (Respiratorias)/efectos de los fármacos , Biopsia , Vasos Sanguíneos/patología , Bronquios/patología , Broncoscopía/métodos , Estudios Transversales , Femenino , Tecnología de Fibra Óptica/métodos , Glucocorticoides/administración & dosificación , Glucocorticoides/uso terapéutico , Sustancias de Crecimiento/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Mucosa Respiratoria/irrigación sanguínea , Mucosa Respiratoria/patologíaRESUMEN
BACKGROUND: Increased numbers of activated neutrophils have been reported in the bronchial mucosa of patients with stable chronic obstructive pulmonary disease (COPD), particularly in severe disease. OBJECTIVES: To investigate the expression of neutrophilic chemokines and adhesion molecules in bronchial biopsies from patients with stable COPD of different severity (GOLD stages I-IV) compared with age-matched control subjects, smokers with normal lung function and never smokers. METHODS: The expression of CCL5, CXCL1, 5, 6, 7 and 8, CXCR1, CXCR2, CD11b and CD44 was measured in the bronchial mucosa using immunohistochemistry, confocal immunofluorescence, real-time quantitative polymerase chain reaction (RT-QPCR) and Western blotting (WB). RESULTS: The numbers of CCL5+ epithelial cells and CCL5+ and CXCL7+ immunostained cells were increased in the bronchial submucosa of patients with stable severe COPD compared with control never smokers and smokers with normal lung function. This was also confirmed at the level of mRNA expression. The numbers of CCL5+ cells in the submucosa of patients with COPD were 2-15 times higher than any other chemokines. There was no correlation between the number of these cells and the number of neutrophils in the bronchial submucosa. Compared with control smokers, the percentage of neutrophils co-expressing CD11b and CD44 receptors was significantly increased in the submucosa of patients with COPD. CONCLUSION: The increased expression of CCL5 and CXCL7 in the bronchial mucosa of patients with stable COPD, together with an increased expression of extracellular matrix-binding receptors on neutrophils, may be involved in the pathogenesis of COPD.
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Quimiocina CCL5/metabolismo , Quimiocinas CXC/metabolismo , Activación Neutrófila , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Enfermedad Aguda , Anciano , Bronquios/inmunología , Bronquios/metabolismo , Antígenos CD11/metabolismo , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Femenino , Humanos , Receptores de Hialuranos/metabolismo , Elastasa de Leucocito/metabolismo , Masculino , Persona de Mediana Edad , Activación Neutrófila/inmunología , Enfermedad Pulmonar Obstructiva Crónica/inmunología , Pruebas de Función Respiratoria , Mucosa Respiratoria/inmunología , Mucosa Respiratoria/metabolismoRESUMEN
There are increased numbers of activated T lymphocytes in the bronchial mucosa of stable chronic obstructive pulmonary disease (COPD) patients. T helper type 17 (Th17) cells release interleukin (IL)-17 as their effector cytokine under the control of IL-22 and IL-23. Furthermore, Th17 numbers are increased in some chronic inflammatory conditions. To investigate the expression of interleukin (IL)-17A, IL-17F, IL-21, IL-22 and IL-23 and of retinoic orphan receptor RORC2, a marker of Th17 cells, in bronchial biopsies from patients with stable COPD of different severity compared with age-matched control subjects. The expression of IL-17A, IL-17F, IL-21, IL-22, IL-23 and RORC2 was measured in the bronchial mucosa using immunohistochemistry and/or quantitative polymerase chain reaction. The number of IL-22(+) and IL-23(+) immunoreactive cells is increased in the bronchial epithelium of stable COPD compared with control groups. In addition, the number of IL-17A(+) and IL-22(+) immunoreactive cells is increased in the bronchial submucosa of stable COPD compared with control non-smokers. In all smokers, with and without disease, and in patients with COPD alone, the number of IL-22(+) cells correlated significantly with the number of both CD4(+) and CD8(+) cells in the bronchial mucosa. RORC2 mRNA expression in the bronchial mucosa was not significantly different between smokers with normal lung function and COPD. Further, we report that endothelial cells express high levels of IL-17A and IL-22. Increased expression of the Th17-related cytokines IL-17A, IL-22 and IL-23 in COPD patients may reflect their involvement, and that of specific IL-17-producing cells, in driving the chronic inflammation seen in COPD.
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Bronquios/inmunología , Interleucina-17/inmunología , Enfermedad Pulmonar Obstructiva Crónica/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Anciano , Análisis de Varianza , Estudios de Casos y Controles , Cartilla de ADN/genética , Femenino , Humanos , Inmunohistoquímica , Interleucina-23/genética , Interleucina-23/inmunología , Interleucinas/genética , Interleucinas/inmunología , Masculino , Persona de Mediana Edad , Membrana Mucosa/inmunología , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares , Reacción en Cadena de la Polimerasa , ARN Mensajero/análisis , Receptores de Ácido Retinoico/genética , Receptores de Ácido Retinoico/inmunología , Receptores de Hormona Tiroidea/genética , Receptores de Hormona Tiroidea/inmunología , Pruebas de Función Respiratoria , Fumar/efectos adversos , Estadísticas no Paramétricas , Interleucina-22RESUMEN
The ultrastructural localization of growth hormone and prolactin in cow anterior pituitary was studied by double immunocytochemical labeling using specific antibodies and protein A-gold particles of different sizes. The two hormones were found in specific somatotrophs and mammotrophs as well as in somatomammotropic cells which were multinucleated and predominantly arranged in clusters in the central area of the lobules. In these mixed cells the two hormones were packaged (a) in different granules of the same cell, (b) in the same granules where they were segregated in different portions of the granule content, or (c) in the same granules but evenly intermixed. The relative proportion of these three types of granules varied in somatomammotrophs of different animals. A single large Golgi complex was generally present in somatomammotrophs. Small, immature granules containing either growth hormone or prolactin or both hormones were found randomly distributed along Golgi stacks. This suggests that in these cells the two hormones are processed in the same Golgi cisternae and that mechanism(s) exist(s) to sort out the two hormones from each other.
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Gránulos Citoplasmáticos/metabolismo , Hormona del Crecimiento/metabolismo , Adenohipófisis/ultraestructura , Prolactina/metabolismo , Animales , Bovinos , Femenino , Oro , Aparato de Golgi/ultraestructura , Histocitoquímica , Técnicas Inmunológicas , Microscopía Electrónica , Adenohipófisis/metabolismo , Proteína Estafilocócica ARESUMEN
The distribution of three proteins discharged by regulated exocytosis--growth hormone (GH), prolactin (PRL), and secretogranin II (SgII)--was investigated by double immunolabeling of ultrathin frozen sections in the acidophilic cells of the bovine pituitary. In mammotrophs, heavy PRL labeling was observed over secretory granule matrices (including the immature matrices at the trans Golgi surface) and also over Golgi cisternae. In contrast, in somatotrophs heavy GH labeling was restricted to the granule matrices; vesicles and tubules at the trans Golgi region showed some and the Golgi cisternae only sparse labeling. All somatotrophs and mammotrophs were heavily positive for GH and PRL, respectively, and were found to contain small amounts of the other hormone as well, which, however, was almost completely absent from granules, and was more concentrated in the Golgi complex, admixed with the predominant hormone. Mixed somatomammotrophs (approximately 26% of the acidophilic cells) were heavily positive for both GH and PRL. Although admixed within Golgi cisternae, the two hormones were stored separately within distinct granule types. A third type of granule was found to contain SgII. Spillage of small amounts of each of the three secretory proteins into granules containing predominantly another protein was common, but true intermixing (i.e., coexistence within single granules of comparable amounts of two proteins) was very rare. It is concluded that in the regulated pathway of acidophilic pituitary, cell mechanisms exist that cause sorting of the three secretory proteins investigated. Such mechanisms operate beyond the Golgi cisternae, possibly at the sites where condensation of secretion products into granule matrices takes place.
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Compartimento Celular , Gránulos Citoplasmáticos/metabolismo , Hormona del Crecimiento/metabolismo , Adenohipófisis/metabolismo , Prolactina/metabolismo , Proteínas/metabolismo , Animales , Bovinos , Cromograninas , Femenino , Inmunohistoquímica , Adenohipófisis/ultraestructuraRESUMEN
Studies carried out on a number of secretory cell systems suggest that the specific cytoplasmic granules in which the secretion products are stored before their release are complex organelles which can possess a distinct molecular organization. For instance, it has been reported that in some granules the segregated secretion products are organized into crystalline structures (1-3) or large intermolecular aggregates (4-8). It is likely that all phenomena of this type are favorable to the economy of the cell, in the sense that they reduce the energy required for storage of the secretion products. The prolactin (LTH) granules of the rat pituitary possess a number of morphological features which strongly suggest that the molecules(s) of their content might be arranged in a relatively stable structure. Thus, these granules are remarkably polymorphic in shape, and their membrane is usually separated from their content by a clear space. Furthermore, identifiable LTH granules devoid of their membrane are often seen in the pericapillary space, suggesting that upon discharge by exocytosis they are dissolved only slowly (9). However, no studies specifically concerned with the mechanisms of LTH storage have been reported so far. In order to obtain some information on this question, we have studied the behavior of isolated granule fractions incubated in vitro under a variety of carefully controlled experimental conditions.