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1.
J Med Syst ; 43(8): 238, 2019 Jun 19.
Article in English | MEDLINE | ID: mdl-31214849

ABSTRACT

Nowadays, one of the choice techniques for the spasticity treatment is the ultrasound-guided infiltration of Botulinum Toxin, because it is safe and effective. In order to medical professionals can carry out this technique, they need training and education. One of the safest and most time-free ways to facilitate the acquisition of practical medical skills is through simulators. In this paper we present an innovative technological environment, which includes an ultrasound simulator for training in muscle exploration and infiltration. The simulation platform will guide health professionals, with great realism and high degree of interactivity, in the autonomous training of all the tasks involved in the spasticity treatment procedure by infiltration of Botulinum Toxin, without the need for a real patient or costly phantoms.


Subject(s)
Botulinum Toxins/administration & dosage , Health Personnel/education , Muscle Spasticity/drug therapy , Musculoskeletal System , Software , Computer Simulation , Humans , Male , Middle Aged , Ultrasonography/methods
2.
J Med Syst ; 40(6): 139, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27106583

ABSTRACT

The training of medical students demands practice of skills in scenarios as close as possible to real ones that on one hand ensure acquisition of competencies, and on the other, avoid putting patients at risk. This study shows the practicality of using high definition mannequins (SimMan 3G) in scenarios of first attention in neurological emergencies so that medical students at the Faculty of Medicine of the University of Salamanca could acquire specific and transversal competencies. The repetition of activities in simulation environments significantly facilitates the acquisition of competencies by groups of students (p < 00.5). The greatest achievements refer to skills whereas the competencies that demand greater integration of knowledge seem to need more time or new sessions. This is what happens with the competencies related to the initial diagnosis, the requesting of tests and therapeutic approaches, which demand greater theoretical knowledge.


Subject(s)
Clinical Competence/standards , Emergencies , Nervous System Diseases/therapy , Simulation Training , Students, Medical , Humans , Manikins
3.
J Neuroradiol ; 41(3): 168-76, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24095291

ABSTRACT

This study presents a computer-based tool for three-dimensional (3D) visualization of the optic pathway and oculomotor system using 3D high-resolution magnetic resonance imaging (MRI) datasets from a healthy subject. The 3D models were built as wireframe grids co-registered with MRI sections. First, 3D anatomical models were generated of the visual pathway from the eyeball to the primary visual cortex and of the cranial oculomotor nerves from the brain stem to the extrinsic eye muscles. Second, a graphical user interface allowed individual and group visualization, translation, rotation and zooming of the 3D models in different spatial positions simultaneously with MRI orthogonal cut planes. Educational and clinical applications are also discussed.


Subject(s)
Brain Stem/anatomy & histology , Diffusion Tensor Imaging/methods , Models, Anatomic , Models, Neurological , Oculomotor Muscles/innervation , Visual Cortex/anatomy & histology , Visual Pathways/anatomy & histology , Adult , Computer Simulation , Female , Humans , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Pattern Recognition, Automated/methods , Reproducibility of Results , Sensitivity and Specificity , User-Computer Interface
4.
J Environ Manage ; 91(1): 149-59, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19735972

ABSTRACT

A methodology has been developed to carry out an integrated oil spill vulnerability index, V, for coastal environments. This index takes into account the main physical, biological and socio-economical characteristics by means of three intermediate indexes. Three different integration methods (worst-case, average and survey-based) along with ESI-based vulnerability scores, V(ESI), proposed for the Cantabrian coast during the Prestige oil spill, have been analyzed and compared in terms of agreement between the classifications obtained with each one for this coastal area. Results of this study indicate that the use of the worst-case index, V(R), leads to a conservative ranking, with a very poor discrimination which is not helpful in coastal oil spill risk management. Due to the homogeneity of this coastal stretch, the rest of the methods, V(I), V(M) and V(ESI), provide similar classifications. However, V(M) and V(I) give more flexibility allowing three indexes for each coastal segment and including socio-economic aspects. Finally, the V(I) procedure is proposed here as the more advisable as using this index promotes the public participation that is a key element in the implementation of Integrated Coastal Zone Management (IZCM).


Subject(s)
Economics , Petroleum , Risk Management , Spain
5.
Sci Total Environ ; 658: 1293-1305, 2019 Mar 25.
Article in English | MEDLINE | ID: mdl-30677991

ABSTRACT

Marine harbours are the focus of a diverse range of activities and subject to multiple anthropogenically induced pressures. Support for environmental management options aimed at improving degraded harbours depends on understanding the factors which influence people's perceptions of harbour environments. We used an online survey, across 12 harbours, to assess sources of variation people's perceptions of harbour health and ecological engineering. We tested the hypotheses: 1) people living near impacted harbours would consider their environment to be more unhealthy and degraded, be more concerned about the environment and supportive of and willing to pay for ecological engineering relative to those living by less impacted harbours, and 2) people with greater connectedness to the harbour would be more concerned about and have greater perceived knowledge of the environment, and be more supportive of, knowledgeable about and willing to pay for ecological engineering, than those with less connectedness. Across twelve locations, the levels of degradation and modification by artificial structures were lower and the concern and knowledge about the environment and ecological engineering were greater in the six Australasian and American than the six European and Asian harbours surveyed. We found that people's perception of harbours as healthy or degraded, but not their concern for the environment, reflected the degree to which harbours were impacted. There was a positive relationship between the percentage of shoreline modified and the extent of support for and people's willingness to pay indirect costs for ecological engineering. At the individual level, measures of connectedness to the harbour environment were good predictors of concern for and perceived knowledge about the environment but not support for and perceived knowledge about ecological engineering. To make informed decisions, it is important that people are empowered with sufficient knowledge of the environmental issues facing their harbour and ecological engineering options.

6.
Sci Total Environ ; 634: 116-126, 2018 Sep 01.
Article in English | MEDLINE | ID: mdl-29627534

ABSTRACT

The present study analysed potential adverse effects of discontinuous sources of contamination, namely the discharge of a combined sewer overflow (CSO) and of runoff in an urban area, the Bay of Santander (North Iberian Peninsula). Water samples and caged mussels were used to analyse concentrations of contaminants and biological responses. Mussels (Mytilus galloprovincialis) were transplanted to a marina receiving runoff from a petrol station and to a CSO discharge site. Samples were collected in synchrony with heavy rains along 62days. Lysosomal membrane stability (LMS) and acyl-CoA oxidase (AOX) activity were measured as core biomarkers and were analysed at all sampling times. Histopathology of digestive gland and gonads, transcription levels of vitellogenin gene, volume density of black silver deposits and micronuclei formation were measured at initial and final stages of the transplant. Chemical analyses of metals, polycyclic aromatic hydrocarbons (PAHs) and endocrine disruptors were performed in water samples and mussel flesh. Mussels accumulated low concentrations of contaminants, which is in accordance with results obtained from exposure biomarkers. AOX activity decreased in all transplanted mussels after the first heavy rain, but this change seems to be related to the seasonal pattern of the enzyme activity. Mussels located close to the CSO discharge site showed a reduction in LMS after the first rain event, when compared to mussels before the transplant and to mussels from the reference location. However, this was attributable to natural environmental changes rather than to pollution. Values of the rest of analysed biomarkers were below threshold values reported for the study area.


Subject(s)
Environmental Monitoring/methods , Mytilus/metabolism , Water Pollutants, Chemical/metabolism , Animals , Biomarkers/metabolism , Endocrine Disruptors/metabolism , Polycyclic Aromatic Hydrocarbons/metabolism , Vitellogenins/metabolism
7.
Mar Environ Res ; 121: 49-63, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27017466

ABSTRACT

Data obtained in a pollution survey performed in estuarine areas were integrated using multivariate statistics. The sites selected for the study were areas affected by treated and untreated urban discharges, harbours or industrial activities as well as reference sites. Mussels were transplanted to each site and after different times of exposure, samples of water, sediments and mussels were collected. Biomarkers were analysed on mussels after 3 and 21 days of transplant whereas concentrations of contaminants were measured in water, sediments and mussels after 21 days of transplant. The structure of macroinvertebrate benthic communities was studied in sediment samples. Studied variables were organised into 5 datasets, each one constituting a line of evidence (LOE): contaminants in water, contaminants in sediments, contaminants accumulated by transplanted mussels, biomarkers in transplanted mussels and changes in the structure of macroinvertebrate benthic communities of each sampling site. Principal Component Analysis (PCA) identified the variables of each LOE best explaining variability among sites. In order to know how LOEs relate to each other, Pearson's correlations were performed. Contaminants in sediments were not correlated with the rest of LOEs. Contaminants in water were significantly correlated with contaminants and biomarkers in mussels and with structure of macroinvertebrate benthic communities. Similarly, significant correlations were found between contaminants and biomarkers in mussels and between biomarkers in mussels and structure of macroinvertebrate benthic communities. In conclusion, biomarker responses give relevant information on pollution in estuarine areas and provide a link between chemical and ecological statuses of water bodies in the context of the Water Framework Directive.


Subject(s)
Bivalvia/physiology , Ecosystem , Environmental Monitoring/methods , Water Pollutants, Chemical/analysis , Animals , Estuaries , Geologic Sediments/chemistry , Polycyclic Aromatic Hydrocarbons
8.
Mar Pollut Bull ; 103(1-2): 301-312, 2016 Feb 15.
Article in English | MEDLINE | ID: mdl-26707886

ABSTRACT

To evaluate the effects of diffuse contamination, biological measurements were applied in a scrap cargo harbour, a marina and an industrial area. Metal accumulation and biomarkers (survival in air, digestive gland and gonad histopathology, lysosomal membrane stability, intralysosomal metal accumulation, transcription of vitellogenin and MT20, peroxisome proliferation and micronuclei formation) were measured in transplanted mussels, together with metrics of benthic invertebrates. Benthic species were classified into ecological groups and univariate indexes were calculated. The marina showed high richness (16) and percentage of opportunistic species (55.1%) and low metal accumulation. Mussels in the scrap cargo harbour showed high metal accumulation, up-regulation of MT20 transcription, reduced health status (LP<6 min) and increased micronuclei frequencies (up to 11.3‰). At the industrial area, low species richness (4) and badly organised assemblages were detected and chemical analyses indicated significant amounts of bioavailable metals. Overall, selected biological measurements showed potential for the assessment of diffuse contamination.


Subject(s)
Environmental Monitoring/methods , Estuaries , Industry , Metals, Heavy/analysis , Mytilus/drug effects , Water Pollutants, Chemical/analysis , Animals , Biomarkers/analysis , Gonads/drug effects , Gonads/metabolism , Metals, Heavy/toxicity , Mytilus/chemistry , Mytilus/genetics , Spain , Up-Regulation , Vitellogenins/genetics , Water Pollutants, Chemical/toxicity
9.
Histol Histopathol ; 9(1): 65-72, 1994 Jan.
Article in English | MEDLINE | ID: mdl-8003823

ABSTRACT

The organization of the efferent projections of the substantia nigra following the injection of 0.4 microliters of 2% Fluoro Gold into the caudate-putamen nucleus of rats of both sexes was studied. After a survival period of 72 h, the greatest number of labelled cells was visualized in the substantia nigra, with lower numbers in adjacent structures (ventral tegmental area, zona incerta and medial lemniscus). The cells featured an intensely fluorescent gold-coloured soma and were varied in shape (round or oval); short sinuous projections arose out of them, corresponding to the dendrites and axons of the neurons. In the statistical study, no significant differences were observed between males and females. A similar pattern of distribution was found ranging from the rostral to the caudal regions of the substantia nigra, occupying the whole of the extent of the substantia nigra; this distribution was most predominant in the rostro-caudal transition of the pars compacta of the substantia nigra.


Subject(s)
Caudate Nucleus/metabolism , Corpus Striatum/metabolism , Fluorescent Dyes/metabolism , Stilbamidines , Substantia Nigra/anatomy & histology , Animals , Biological Transport , Female , Male , Microscopy, Fluorescence , Neurons/cytology , Rats , Rats, Wistar , Sex Characteristics , Substantia Nigra/metabolism
10.
Histol Histopathol ; 8(2): 213-8, 1993 Apr.
Article in English | MEDLINE | ID: mdl-8490247

ABSTRACT

A combined morphological study using transmission and scanning electron microscopy was carried out on the central zone of the rostral wall of the III ventricle from a sample taken during the operation of a patient with a retrochiasmatic craniopharyngioma. Under the scanning electron microscope, the apical cell wall of the ependymocytes generally appeared folded and lack in cilia, but with numerous microvilli developed to different extents. The flat surface cells were scarce and were polygonal in shape and limited by 3-7 prominent edges. Ultrastructural analysis revealed the existence of several types of ependymocytes and subependymal epithelial cells arranged in different layers; in both layers the presence of abundant neurofilaments and intercellular junctions was striking.


Subject(s)
Cerebral Ventricles/ultrastructure , Brain Neoplasms/ultrastructure , Child , Craniopharyngioma/ultrastructure , Ependyma/ultrastructure , Epithelium/ultrastructure , Humans , Male , Microscopy, Electron , Microscopy, Electron, Scanning
11.
Histol Histopathol ; 18(2): 419-23, 2003 04.
Article in English | MEDLINE | ID: mdl-12647792

ABSTRACT

At our laboratory, we have recently demonstrated the immunohistochemical expression of aromatase P450 in the pituitary glands of adult rats; this expression was seen to be sex-dependent. In order to determine whether the changes in the expression of the enzyme are related to changes in the gonadal sphere and whether the expression of the enzyme is related to the postnatal differentiation of hypophyseal cytology, in the present work we performed an immunohistochemical study in the rat pituitary gland from birth to old age. The immunohistochemical reaction to aromatase was evident and very generalized at 7 days after birth, with no large differences between the male and female animals. At 14 days the immunohistochemical reaction was decreased in the females, with no changes in the males. At 17 days, aromatase immunoreactivity in the pituitary glands of female rats was very weak whereas the males showed large numbers of reactive cells. These observations were further pronounced at 21 days and 2 months of life. At 24 months, the immunoreactivity found in the pituitary glands of the male rats had almost completely disappeared. Our results show that a postnatal differentiation in the immunohistochemical expression of aromatase occurs; this is tightly linked to sexual activity and is lost in old age. This suggests that hypophyseal aromatase would be related to the mechanisms of action of gonadal steroids on hypophyseal differentiation and secretion.


Subject(s)
Aromatase/biosynthesis , Pituitary Gland/enzymology , Pituitary Gland/growth & development , Animals , Animals, Newborn , Cell Differentiation , Female , Immunohistochemistry , Male , Pituitary Gland/cytology , Rats , Rats, Sprague-Dawley , Sex Differentiation/physiology
12.
Histol Histopathol ; 7(4): 673-7, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1360849

ABSTRACT

In order to elucidate whether the gender differences observed in the somatotropic cells of adult rats are mediated by hypothalamic neuropeptides, a morphometric analysis was made of the GH-immunoreactive cells of adult rats treated intraventricularly with colchicine. The morphometric and morphological findings obtained were correlated to the basal serum levels of GH at the time of sacrifice. Treatment with colchicine was seen to increase serum GH levels; this increase was accompanied by an increase in the intensity of the reaction of the GH-cells and, morphometrically, an increase in their size due to an increase in the nuclear area, but with no significant changes in the cytoplasmic area. The results suggest that in the absence of somatostatin and GRF the basal release of GH is elevated in a similar fashion in both sexes, in turn suggesting that gonadal steroids might act at hypothalamic level on the release of somatostatin and, indirectly, on the intracellular pool of GH and hormonal secretion.


Subject(s)
Colchicine/pharmacology , Growth Hormone/metabolism , Pituitary Gland, Anterior/cytology , Animals , Colchicine/administration & dosage , Female , Growth Hormone/immunology , Growth Hormone-Releasing Hormone/pharmacology , Immunohistochemistry , Injections, Intraventricular , Male , Pituitary Gland, Anterior/ultrastructure , Rats , Rats, Sprague-Dawley , Somatostatin/pharmacology
13.
Histol Histopathol ; 7(4): 719-24, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1457994

ABSTRACT

Using the peroxidase-antiperoxidase immunocytochemical technique, a morphometric study of the magnocellular neurons of the Paraventricular nucleus of the rat hypothalamus, reactive to specific anti-vasopressin rabbit serum, was made. Following systemic and chronic administration of met-enkephalin the number of immunoreactive neurons was higher, especially in females. Additionally, in the females, it was possible to observe an increase in the immunoreactivity and the presence of well-stained fibres. These findings suggest, especially in females, a blockage in the release of vasopressin, facilitating its immunocytochemical visualization.


Subject(s)
Enkephalin, Methionine/pharmacology , Neurons/drug effects , Paraventricular Hypothalamic Nucleus/metabolism , Vasopressins/physiology , Animals , Female , Immunoenzyme Techniques , Immunohistochemistry , Male , Paraventricular Hypothalamic Nucleus/cytology , Paraventricular Hypothalamic Nucleus/drug effects , Rats , Rats, Sprague-Dawley , Sex Characteristics
14.
Histol Histopathol ; 16(4): 1107-16, 2001 10.
Article in English | MEDLINE | ID: mdl-11642731

ABSTRACT

To analyze whether the reorganization of the rat median eminence after hypophysectomy might be related to changes in glial fibrillary acidic protein (GFAP)- and cellular proliferation, the distribution of cells immunoreactive for GFAP and the proliferation rate of such cells were analyzed at 20, 40 and 60 days posthypophysectomy. For this study, four rostro-caudal regions of the median eminence were differentiated: the retrochiasmatic, preinfundibular, infundibular and postinfundibular regions. In each of these regions, three layers were studied: the ependymal, the internal and the external. At 20 and 40 days after hypophysectomy, significant increases in cellular proliferation affecting all three layers studied in the preinfundibular and infundibular regions were found. At the same time points, increases in GFAP expression were also observed. However, after 60 days, GFAP and proliferative cellular nuclear antigen (PCNA) expression decreased. Although variations of PCNA and GFAP levels were evident, no colocalisation of PCNA and GFAP was found in the cells of the median eminence in untreated or hypophysectomized rats when sections were analyzed by double immunohistochemical staining. Our results suggest that reorganization of median eminence involves alterations (or modulation) of GFAP-immunoreactive cells together with a proliferation of cells that are not GFAP-immunoreactive. This study also demonstrates that this reorganization is completed within the first two months after hypophysectomy.


Subject(s)
Glial Fibrillary Acidic Protein/biosynthesis , Hypophysectomy , Median Eminence/cytology , Median Eminence/metabolism , Pituitary Gland/physiology , Animals , Cell Division/physiology , Immunohistochemistry , Male , Proliferating Cell Nuclear Antigen/biosynthesis , Proliferating Cell Nuclear Antigen/genetics , Rats , Rats, Sprague-Dawley
15.
Neuropeptides ; 31(3): 227-30, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9243518

ABSTRACT

The presence and distribution of NADPH-diaphorase (ND) neurons as well as tyrosine hydroxylase-immunoreactive (TH) neurons in the hypothalamus are well established. Previous studies have shown the coexistence of ND with neuroactive substances such as calbindin, somatostatin, vasopressin and oxytocin in neurons of this region of the brain. As the tópographical patterns of distribution of ND and TH coincide in many cases, the aim of this study was to determine the possible coexistence of both substances in the main hypothalamic magnocellular nuclei of the albino rat. Histochemical-immunocytochemical double labelling was employed on the same sections as well as a morphometric study. NADPH-diaphorase and tyrosine hydroxylase neurons were observed in all the nuclei under study (supraoptic, paraventricular and accessory nuclei), although most neurons showing the coexistence of both substances were mainly located in the supraoptic nucleus, isolated neurons with double labelling being found in the magnocellular parts of the paraventricular nucleus and in some of the accessory nuclei. Although both substances have previously been shown to be modified in hypothalamic neurons after osmotic stimuli, the range of functions of ND in the CNS is only beginning to be understood. Further studies are needed to elucidate the functional role that ND/TH neurons play in the nervous system.


Subject(s)
NADPH Dehydrogenase/analysis , Neurons/enzymology , Paraventricular Hypothalamic Nucleus/cytology , Supraoptic Nucleus/cytology , Tyrosine 3-Monooxygenase/analysis , Animals , Antibodies/pharmacology , Biomarkers , Male , NADPH Dehydrogenase/immunology , Paraventricular Hypothalamic Nucleus/enzymology , Rats , Rats, Wistar , Supraoptic Nucleus/enzymology , Tyrosine 3-Monooxygenase/immunology
16.
Neuropeptides ; 17(3): 127-34, 1990 Nov.
Article in English | MEDLINE | ID: mdl-2084576

ABSTRACT

The morphological-morphometric consequences of bilateral adrenalectomy on vasopressin-reacting neurons of the paraventricular nucleus of the rat hypothalamus were analyzed. Bilateral adrenalectomy led to a dramatic increase in the cellular area as well as the number of immunoreactive cells (when compared to those obtained in normal colchicine-treated animals) in the neurons located in the anterior, medial and periventricular parvicellular subdivisions of the paraventricular nucleus. By contrast, no changes were observed in either the dorsal or lateral parvicellular subdivisions or in any of the magnocellular subdivisions of the paraventricular nucleus.


Subject(s)
Adrenalectomy , Neurons/cytology , Paraventricular Hypothalamic Nucleus/cytology , Vasopressins/analysis , Animals , Colchicine/pharmacology , Female , Immunoenzyme Techniques , Male , Neurons/chemistry , Neurons/drug effects , Paraventricular Hypothalamic Nucleus/drug effects , Rats , Rats, Inbred Strains
17.
J Epidemiol Community Health ; 55(6): 442-7, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11351003

ABSTRACT

STUDY OBJECTIVE: To find out whether bathing in sewage polluted waters implies a danger to bathers' health and to determine the best microbiological indicator to predict the relation between bathing and the appearance of some symptoms. DESIGN: Cohort study. SETTING: City of Santander (north of Spain). PARTICIPANTS: From the people going to four Santander beaches in the period from 1 July to 16 September 1998, a cohort of 2774 persons was recruited who agreed to participate in this study. Of those, 1858 successfully completed a follow up interview conducted in seven days. Respiratory, gastrointestinal, eye, and ear symptoms, and fever occurring during the seven day follow up were recorded. MAIN RESULTS: A total of 136 participants (7.5%) reported symptoms. Visitors reported experiencing symptoms with more frequency than residents. Incidence rates of gastrointestinal, cutaneous and high respiratory tract symptoms were higher in bathers, but the differences were not significant. Total symptoms were related with the amount of total coliforms, faecal coliforms, and faecal streptococci in the water. Gastrointestinal and skin symptoms kept a positive trend with the degree of water pollution by total coliforms in both crude and adjusted analyses. An increased risk was observed in 2500-9999 total coliforms per 100 ml, a figure over the proposed standard, although below the European Union mandatory limit. CONCLUSIONS: The results of this study suggest that total coliforms are the best predictors of the symptoms.


Subject(s)
Bacterial Infections/transmission , Seawater/microbiology , Sewage/adverse effects , Swimming , Water Pollution/adverse effects , Adolescent , Adult , Aged , Aged, 80 and over , Bacterial Infections/epidemiology , Child , Child, Preschool , Enterobacteriaceae/isolation & purification , Feces/microbiology , Female , Follow-Up Studies , Humans , Incidence , Infant , Infant, Newborn , Male , Middle Aged , Risk Assessment , Spain/epidemiology
18.
Anat Embryol (Berl) ; 186(1): 99-105, 1992.
Article in English | MEDLINE | ID: mdl-1514707

ABSTRACT

A stimulatory effect on prolactin secretion had been describe after acute and systemic administration of met-enkephalin, but the effects of this opioid after chronic administration has not been reported, and the response of mammotroph cells is not clear. As a complement to previous studies, a morphometric analysis (light and electron microscopy) was carried out on prolactin cells from female rats treated chronically with met-enkephalin. Clear features of cellular hyperactivity appeared after chronic and systemic administration of the opioid, and these persisted for two weeks. The changes consisted in increases of cellular, cytoplasmic and nuclear areas, volume and surface densities of the Golgi complex and rough endoplasmic reticulum, as well as the numbers of exocytotic figures. These morphological alterations were paralleled by an increase in serum prolactin levels as detected by RIA. It is concluded that the increase in the synthesis and secretory activity of prolactin cells following chronic and systemic administration of met-enkephalin is very similar to those observed after acute and intraventricular administration.


Subject(s)
Enkephalin, Methionine/pharmacology , Pituitary Gland, Anterior/metabolism , Prolactin/metabolism , Analysis of Variance , Animals , Endoplasmic Reticulum/drug effects , Female , Golgi Apparatus/drug effects , Injections, Intramuscular , Microscopy, Electron , Pituitary Gland, Anterior/drug effects , Pituitary Gland, Anterior/ultrastructure , Radioimmunoassay , Rats , Rats, Inbred Strains
19.
Anat Embryol (Berl) ; 198(6): 439-50, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9833684

ABSTRACT

To assess the involvement of cellular inhibition and the appearance of apoptosis in regression of the hyperplastic thyroid gland towards normality, an experimental design was used to elicit non-toxic goiter by inducing hyperplastic goiter in rats by treatment with methimazole. We performed a morphological and PCNA immunocytochemical study together with in situ end labelling with bromodeoxyuridine in thyroid glands of rats receiving methimazole in their drinking water over 21 days after which they were allowed a recovery period of 0, 12, 24, 36, 48 and 72 h and 7, 14, 21 and 44 days. Serum T3 and T4 levels were found to be very low in the methimazole-treated animals although they increased after the goitrogenic compound had been withdrawn. Inhibition of cell proliferation and the burst of apoptosis play important roles in the regression of hyperplastic goiter in rats. Cell proliferation, which was strongly stimulated during goiter, fell significantly at 24 h, thereafter decreasing gradually as the recovery period progressed. Isolated cases of thyrocyte necrosis were observed ultrastructurally. Light and transmission electron microscopy revealed the existence of thyroid apoptosis with respect to the development of the study over time. Most apoptotic thyrocytes became detached from the follicular epithelium and later underwent cellular degeneration in the follicular lumen. The remaining apoptotic cells retracted their cytoplasm, lost contact with the follicular lumen and became located at the base of the follicles. The percentage of apoptosis showed that during the first week of thyroid involution apoptosis was already present but with low percentages while maximum values were attained at 21 days of survival. Our results suggest that, in the rat, during the return of thyroid follicular cells to normality after methimazole-induced hyperplastic goiter a balance arises between proliferation and cell death and that this balance is due to the inhibition of cellular proliferation and, secondarily, to the appearance of apoptosis, which becomes particularly evident towards the end of the first week after withdrawing the goitrogenic agent.


Subject(s)
Apoptosis , Goiter/pathology , Thyroid Gland/pathology , Animals , Antithyroid Agents , Bromodeoxyuridine/metabolism , Cell Division , Epithelial Cells/metabolism , Epithelial Cells/ultrastructure , Female , Goiter/chemically induced , Goiter/metabolism , Hyperplasia/chemically induced , Hyperplasia/metabolism , Hyperplasia/pathology , Immunoenzyme Techniques , In Situ Nick-End Labeling , Male , Methimazole , Proliferating Cell Nuclear Antigen/analysis , Rats , Rats, Sprague-Dawley , Thyroid Gland/drug effects , Thyroxine/blood , Triiodothyronine/blood
20.
Acta Histochem ; 93(1): 271-6, 1992.
Article in English | MEDLINE | ID: mdl-1529669

ABSTRACT

In order to elucidate the response of somatotropic cells to the influence of gonadal steroids on the regulation of growth hormone secretory patterns, a morphometric analysis was carried out on the GH-immunoreactive cells of adult male rats treated chronically with intramuscular injections of estradiol valerate. The morphometric and morphological results obtained were correlated to the serum levels of GH at the moment of sacrifice. Treatment with a daily dose of 125 micrograms of estradiol vaterate over 15 d was seen to lead to an increase (p less than 0.01) in the serum GH values accompanied by a decrease in the intensity of reaction of the GH-cells and, morphometrically, a reduction in their size (p less than 0.01) due to a decrease in the cytoplasmic area (p less than 0.01), but without significant changes in the nuclear area. Our results suggest that in male rats estrogens enhance the release of the intracellular GH pool but that they do not affect hormone synthesis to a great extent.


Subject(s)
Estradiol/analogs & derivatives , Growth Hormone/blood , Pituitary Gland/drug effects , Analysis of Variance , Animals , Cytoplasm/ultrastructure , Dose-Response Relationship, Drug , Estradiol/pharmacology , Growth Hormone/analysis , Immunohistochemistry , Male , Pituitary Gland/cytology , Rats , Rats, Inbred Strains
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