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1.
Biol Lett ; 19(8): 20230312, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37643644

RESUMO

The Lower Devonian (Lower Emsian, -400 Myr) roof slates of the Hunsrück in southeastern Germany have delivered a highly diverse and exceptionally preserved marine fauna that provides a unique snapshot into the anatomy and ecology of a wide range of Palaeozoic animals. Several of the described taxa, however, remain enigmatic in their affinity, at least until new pyritized features hidden under the surface of the slate are revealed using X-ray radiography or micro-computed tomography (µCT). Here, we redescribe such an enigmatic fossil, the putative anostracan crustacean Gilsonicaris rhenanus Van Straelen, 1943. Using µCT scanning, we unveil unprecedented details of its anatomy, including a ventral oral opening and four pairs of recalcitrant jaw elements. These jaws are morphologically consistent with the scolecodonts of eunicidan polychaetes, which along with the gross anatomy of the body and head unambiguously identifies G. rhenanus as a polychaete rather than an arthropod. While this discovery firmly discards the Early Devonian record of crown anostracans in the fossil record, it adds a new record of eunicidan soft tissues, which are surprisingly rare considering the abundant microfossil record of scolecodonts.


Assuntos
Artrópodes , Crustáceos , Animais , Microtomografia por Raio-X , Ecologia , Fósseis
2.
Int J Cosmet Sci ; 40(2): 148-156, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29355981

RESUMO

OBJECTIVE: Examination of the skin barrier repair/wound healing process using a living skin equivalent (LSE) model and matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) to identify lipids directly involved as potential biomarkers. These biomarkers may be used to determine whether an in vivo wound is going to heal for example if infected. METHODS: An in vitro LSE model was wounded with a scalpel blade and assessed at day 4 post-wounding by histology and MALDI-MSI. Samples were sectioned at wound site and were either formalin-fixed paraffin-embedded (FFPE) for histology or snapped frozen (FF) for MSI analysis. RESULTS: The combination of using an in vitro wounded skin model with MSI allowed the identification of lipids involved in the skin barrier repair/wound healing process. The technique was able to highlight lipids directly in the wound site and distinguish differences in lipid distribution between the epidermis and wound site. CONCLUSION: This novel method of coupling an in vitro LSE with MSI allowed in-depth molecular analysis of the skin barrier repair/wound healing process. The technique allowed the identification of lipids directly involved in the skin barrier repair/wound healing process, indicating these biomarkers may be potentially be used within the clinic. These biomarkers will help to determine, which stage of the skin barrier repair/wound healing process the wound is in to provide the best treatment.


Assuntos
Pele/fisiopatologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Cicatrização , Biomarcadores/metabolismo , Análise Discriminante , Humanos , Técnicas In Vitro , Inclusão em Parafina , Análise de Componente Principal
3.
Nat Ecol Evol ; 6(8): 1095-1104, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35879540

RESUMO

Cnidarians are a disparate and ancient phylum, encompassing corals and jellyfish, and occupy both the pelagic and benthic realms. They have a rich fossil record from the Phanerozoic eon lending insight into the early history of the group but, although cnidarians diverged from other animals in the Precambrian period, their record from the Ediacaran period (635-542 million years ago) is controversial. Here, we describe a new fossil cnidarian-Auroralumina attenboroughii gen. et sp. nov.-from the Ediacaran of Charnwood Forest (557-562 million years ago) that shows two bifurcating polyps enclosed in a rigid, polyhedral, organic skeleton with evidence of simple, densely packed tentacles. Auroralumina displays a suite of characters allying it to early medusozoans but shows others more typical of Anthozoa. Phylogenetic analyses recover Auroralumina as a stem-group medusozoan and, therefore, the oldest crown-group cnidarian. Auroralumina demonstrates both the establishment of the crown group of an animal phylum and the fixation of its body plan tens of millions of years before the Cambrian diversification of animal life.


Assuntos
Cnidários , Animais , Evolução Biológica , Florestas , Filogenia , Reino Unido
4.
Biochem Biophys Res Commun ; 413(1): 24-9, 2011 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-21867687

RESUMO

In mammals, the GCN2/ATF4 pathway has been described as the main pathway involved in the regulation of gene expression upon amino acid limitation. This regulation is notably conferred by the presence of a cis-element called Amino Acid Response Element (AARE) in the promoter of specific genes. In vivo, the notion of amino acid limitation is not limited to nutritional context, indeed several pathological situations are associated with alteration of endogenous amino acid availability. This is notably true in the context of tumour in which the alteration of the microenvironment can lead to a perturbation in nutrient availability. P8 is a small weakly folded multifunctional protein that is overexpressed in several kinds of cancers and whose expression is induced by different stresses. In this study we have demonstrated that amino acid starvation was also able to induce p8 expression. Moreover, we brought the evidence, in vitro and in vivo, that the GCN2/ATF4 pathway is involved in this regulation through the presence of an AARE in p8 promoter.


Assuntos
Fator 4 Ativador da Transcrição/metabolismo , Aminoácidos/deficiência , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Proteínas de Neoplasias/genética , Proteínas Serina-Treonina Quinases/metabolismo , Elementos Reguladores de Transcrição , Animais , Leucina/deficiência , Camundongos , Células NIH 3T3
5.
Proc Natl Acad Sci U S A ; 104(47): 18555-60, 2007 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-18003934

RESUMO

Biodiversity loss from deforestation may be partly offset by the expansion of secondary forests and plantation forestry in the tropics. However, our current knowledge of the value of these habitats for biodiversity conservation is limited to very few taxa, and many studies are severely confounded by methodological shortcomings. We examined the conservation value of tropical primary, secondary, and plantation forests for 15 taxonomic groups using a robust and replicated sample design that minimized edge effects. Different taxa varied markedly in their response to patterns of land use in terms of species richness and the percentage of species restricted to primary forest (varying from 5% to 57%), yet almost all between-forest comparisons showed marked differences in community structure and composition. Cross-taxon congruence in response patterns was very weak when evaluated using abundance or species richness data, but much stronger when using metrics based upon community similarity. Our results show that, whereas the biodiversity indicator group concept may hold some validity for several taxa that are frequently sampled (such as birds and fruit-feeding butterflies), it fails for those exhibiting highly idiosyncratic responses to tropical land-use change (including highly vagile species groups such as bats and orchid bees), highlighting the problems associated with quantifying the biodiversity value of anthropogenic habitats. Finally, although we show that areas of native regeneration and exotic tree plantations can provide complementary conservation services, we also provide clear empirical evidence demonstrating the irreplaceable value of primary forests.


Assuntos
Biodiversidade , Agricultura Florestal , Clima Tropical
6.
Clin Exp Allergy ; 39(5): 760-70, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19226276

RESUMO

BACKGROUND: As a complex molecule requiring post-translational processing, it has been difficult to produce the Der p 1 major allergen from the Dermatophagoides pteronyssinus house dust mite in a recombinant form. OBJECTIVE: Here, we tested whether transgenic tobacco plants are suitable to express Der p 1, either as a wild-type molecule or as variants lacking N-glycosylation sites (Gly(-)) and/or cysteine protease activity (Enz(-)). Methods Using Agrobacterium tumefaciens-based transformation, pro Der p 1 molecules bearing mutations within either the N-glycosylation sites (N34Q, N150Q) and/or the cysteine protease-active site (C132V) were expressed in tobacco plants. After purification by ion exchange chromatography, allergens were characterized using immunoblotting, circular dichroism (CD), as well as basophil and T lymphocyte stimulation assays. RESULTS: Four forms of recombinant Der p 1 (i.e. wild-type Gly(+)/Enz(+), as well as Gly(-)/Enz(+), Gly(+)/Enz(-) or Gly(-)/Enz(-) variants) were successfully expressed in tobacco leaves as pro Der p 1 molecules. Spontaneous cleavage of the pro-peptide was observed in tobacco leaf extracts for all forms of recombinant Der p 1 (r Der p 1). CD confirmed that all r Der p 1 molecules, with the exception of the Gly(-)/Enz(-) variant, exhibited secondary structures comparable to the natural protein. A cysteine protease activity was associated only with the Gly(+)/Enz(+) form. All these molecules exhibit a profile similar to natural Der p 1 with respect to IgE immunoreactivity, basophil activation and T cell recognition. CONCLUSION: A tobacco plant expression system allows the production of various forms of mature Der p 1, which could be used for diagnostic or immunotherapeutic purposes.


Assuntos
Antígenos de Dermatophagoides/biossíntese , Clonagem Molecular , Nicotiana/genética , Antígenos de Dermatophagoides/genética , Antígenos de Dermatophagoides/imunologia , Proteínas de Artrópodes , Basófilos/imunologia , Basófilos/metabolismo , Linhagem Celular , Cisteína Endopeptidases , Humanos , Diester Fosfórico Hidrolases/imunologia , Diester Fosfórico Hidrolases/metabolismo , Folhas de Planta/genética , Plantas Geneticamente Modificadas , Pirofosfatases/imunologia , Pirofosfatases/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo
7.
Med Sci Law ; 49(3): 179-84, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19787989

RESUMO

In the U.K., cases of sudden unexpected death in infancy are under the jurisdiction of the Coroner and consent for a post-mortem is not required. Prior to the Human Tissue Act 2006 (HTA) there was also no requirement to request retention of tissue (blocks and slides). The HTA stipulates that parental/ guardian consent is mandatory to retain or dispose of all tissues after the Coroners' purposes have been fulfilled. In 2007, in order to avoid confusion with the consent needed for hospital post-mortems, a new form was introduced by Sheffield Children's Hospital NHS Foundation Trust (SCH) called Record of parents'/guardians'wishes regarding samples taken at a Coroner's post mortem. This version specifically asks if blocks and slides may be retained as part of the medical record, or are to be disposed of, and for parental agreement (or not) for the frozen tissue, blocks and slides to be used for education, audit, quality control and medical research. One hundred and nineteen Coroners' postmortems covering the years 2006-2007 were reviewed. All parents/guardians (P/G) were contacted and the outcomes of P/G wishes recorded by SCH staff, Coroners' Officers (CO) and Police Family Liaison Officers (PFLO) were analysed and compared (44% from CO were outstanding at the time of audit). Any delay in recording P/G wishes by these three groups was also compared. In 2006, parental agreement to the use of blocks and slides for education, audit, quality control and medical research was 94%, 77% and 75% for SCH, CO and PFLO, respectively. In 2007 it was 84%, 37% and 100% for the same groups. Permission for the retention of frozen tissue given to SCH, CO and PFLO was 90%, 62% and 100% in 2006 and 90%, 44% and 100% in 2007, respectively. Cases where parents did not wish for the retention or use of tissue (including blocks and slides) were 3%, 15% and 0% in 2006 for SCH, CO and PFLO respectively, and 0% for all groups in 2007. Training of staff in all aspects of post-mortem and bereavement care is essential for ascertaining parental wishes. Families should be provided with the knowledge that allows them to make informed choices. The analysis of the results of the audit supports this view.


Assuntos
Autopsia/legislação & jurisprudência , Tutores Legais , Pais , Morte Súbita do Lactente , Obtenção de Tecidos e Órgãos/legislação & jurisprudência , Atitude Frente a Saúde , Humanos , Lactente , Consentimento Livre e Esclarecido/legislação & jurisprudência , Auditoria Médica , Estudos Retrospectivos , Reino Unido
8.
Sci Data ; 6(1): 161, 2019 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-31467271

RESUMO

Sustained, quantitative observations of nearshore waves and sand levels are essential for testing beach evolution models, but comprehensive datasets are relatively rare. We document beach profiles and concurrent waves monitored at three southern California beaches during 2001-2016. The beaches include offshore reefs, lagoon mouths, hard substrates, and cobble and sandy (medium-grained) sediments. The data span two energetic El Niño winters and four beach nourishments. Quarterly surveys of 165 total cross-shore transects (all sites) at 100 m alongshore spacing were made from the backbeach to 8 m depth. Monthly surveys of the subaerial beach were obtained at alongshore-oriented transects. The resulting dataset consists of (1) raw sand elevation data, (2) gridded elevations, (3) interpolated elevation maps with error estimates, (4) beach widths, subaerial and total sand volumes, (5) locations of hard substrate and beach nourishments, (6) water levels from a NOAA tide gauge (7) wave conditions from a buoy-driven regional wave model, and (8) time periods and reaches with alongshore uniform bathymetry, suitable for testing 1-dimensional beach profile change models.

9.
R Soc Open Sci ; 5(3): 180154, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29658961

RESUMO

[This corrects the article DOI: 10.1098/rsos.170833.].

10.
Br J Pharmacol ; 174(10): 1002-1014, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27590257

RESUMO

The peptide hormone relaxin regulates the essential maternal haemodynamic adaptations in early pregnancy through direct actions on the renal and systemic vasculature. These vascular actions of relaxin occur mainly through endothelium-derived NO-mediated vasodilator pathways and improvements in arterial compliance in small resistance-size arteries. This work catalysed a plethora of studies which revealed quite heterogeneous responses across the different regions of the vasculature, and also uncovered NO-independent mechanisms of relaxin action. In this review, we first describe the role of endogenous relaxin in maintaining normal vascular function, largely referring to work in pregnant and male relaxin-deficient animals. We then discuss the diversity of mechanisms mediating relaxin action in different vascular beds, including the involvement of prostanoids, VEGF, endothelium-derived hyperpolarisation and antioxidant activity in addition to the classic NO-mediated vasodilatory pathway. We conclude the review with current perspectives on the vascular remodelling capabilities of relaxin. LINKED ARTICLES: This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.


Assuntos
Endotélio Vascular/metabolismo , Óxido Nítrico/metabolismo , Relaxina/metabolismo , Animais , Humanos
11.
Br J Pharmacol ; 173(6): 1005-17, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26660642

RESUMO

BACKGROUND AND PURPOSE: In the RELAX-AHF trial, a 48 h i.v. serelaxin infusion reduced systemic vascular resistance in patients with acute heart failure. Consistent with preclinical studies, serelaxin augments endothelial vasodilator function in rat mesenteric arteries. Little is known about the contribution of endothelium-derived relaxing factors after a longer duration of continuous serelaxin treatment. Here we have assessed vascular reactivity and mechanistic pathways in mesenteric arteries and veins and the aorta after 48 or 72 h continuous i.v. infusion of serelaxin. EXPERIMENTAL APPROACH: Male rats were infused with either placebo or serelaxin (13.3 µg·kg(-1) ·h(-1) ) via the jugular vein using osmotic minipumps. Vascular function was assessed using wire myography. Changes in gene and protein expression and 6-keto PGF1α levels were determined by quantitative PCR, Western blot and ELISA respectively. KEY RESULTS: Continuous i.v. serelaxin infusion augmented endothelium-dependent relaxation in arteries (mesenteric and aorta) but not in mesenteric veins. In mesenteric arteries, 48 h i.v. serelaxin infusion increased basal NOS activity, associated with increased endothelial NOS (eNOS) expression. Interestingly, phosphorylated-eNOS(Ser1177) , eNOS and basal NOS activity were reduced in mesenteric arteries following 72 h serelaxin treatment. At 72 h, serelaxin treatment improved bradykinin-mediated relaxation through COX2-derived PGI2 production. CONCLUSIONS AND IMPLICATIONS: Continuous i.v. serelaxin infusion enhanced endothelial vasodilator function in arteries but not in veins. The underlying mediator at 48 h was NO but there was a transition to PGI2 by 72 h. Activation of the PGI2 -dependent pathway is key to the prolonged vascular response to serelaxin treatment.


Assuntos
Aorta Abdominal/efeitos dos fármacos , Epoprostenol/fisiologia , Artérias Mesentéricas/efeitos dos fármacos , Óxido Nítrico/fisiologia , Relaxina/farmacologia , Animais , Aorta Abdominal/fisiologia , Infusões Intravenosas , Masculino , Artérias Mesentéricas/fisiologia , Veias Mesentéricas/efeitos dos fármacos , Veias Mesentéricas/fisiologia , Ratos Wistar , Proteínas Recombinantes/sangue , Proteínas Recombinantes/farmacologia , Relaxina/sangue , Transdução de Sinais , Vasodilatação/efeitos dos fármacos
12.
Sci Total Environ ; 527-528: 530-9, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26003614

RESUMO

Peatlands are important sources of fluvial carbon. Previous research has shown that riverine dissolved organic carbon (DOC) concentrations are largely controlled by soil type. However, there has been little work to establish the controls of riverine DOC within blanket peatlands that have not undergone major disturbance from drainage or burning. A total of 119 peatland catchments were sampled for riverine DOC and water colour across three drainage basins during six repeated sampling campaigns. The topographic characteristics of each catchment were determined from digital elevation models. The dominant vegetation cover was mapped using 0.5m resolution colour infrared aerial images, with ground-truthed validation revealing 82% accuracy. Forward and backward stepwise regression modelling showed that mean slope was a strong (and negative) determinant of DOC and water colour in blanket peatland river waters. There was a weak role for plant functional type in determining DOC and water colour. At the basin scale, there were major differences between the models depending on the basin. The dominance of topographic predictors of DOC found in our study, combined with a weaker role of vegetation type, paves the way for developing improved planning tools for water companies operating in peatland catchments. Using topographic data and aerial imagery it will be possible to predict which tributaries will typically yield lower DOC concentrations and which are therefore more suitable and cost-effective as raw water intakes.

13.
Endocrinology ; 129(1): 47-52, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1829033

RESUMO

Experiments were conducted to investigate the role of the brain angiotensin system in mediating the pressor effects of porcine relaxin in anesthetized female rats. Continuous intracerebroventricular infusion of a specific angiotensin II receptor antagonist (Sar1-Ala8-angiotensin II) completely negated the pressor response to centrally administered relaxin, but only partially suppressed the increase in blood pressure observed after iv injection of the hormone. These results indicate that the pressor effects of relaxin may be mediated, at least in part, by brain angiotensin. Rats with a compromised central angiotensin system were then treated in combination with a peripheral vasopressin (V1) receptor antagonist. Only after both treatments were the pressor effects of iv relaxin completely negated. These data imply that there is also a significant pressor action of relaxin which is independent of the brain angiotensin system. The most likely alternative is a direct action of relaxin on the neural lobe of the pituitary, to provoke the release of vasopressin.


Assuntos
Angiotensina II/fisiologia , Pressão Sanguínea/efeitos dos fármacos , Relaxina/farmacologia , Angiotensina II/farmacologia , Antagonistas de Receptores de Angiotensina , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Feminino , Cinética , Ratos , Ratos Endogâmicos , Receptores de Angiotensina/fisiologia , Receptores de Vasopressinas , Saralasina/farmacologia
14.
Endocrinology ; 134(3): 1188-92, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8119158

RESUMO

Experiments were conducted in anesthetized rats to assess the contribution of the brain angiotensin-II system in the relaxin-induced secretion of vasopressin and oxytocin. Intravenous injection of porcine relaxin (5 micrograms) caused a significant (P < 0.05, by analysis of variance) increase in plasma concentrations of both hormones. Peak concentrations of both vasopressin (75.2 +/- 2.9 pmol/liter) and oxytocin (38.4 +/- 1.2 pmol/liter) were observed 1-2.5 min after relaxin injection. Thereafter, concentrations fell significantly (P < 0.05) but remained elevated for a further 25 minutes. Continuous infusion of a specific angiotensin-II receptor antagonist into the lateral cerebral ventricle did not affect baseline levels of either vasopressin or oxytocin, but did significantly reduce (P < 0.05) the relaxin-induced release of both peptides. A significant (P < 0.05) short term increase in both plasma vasopressin and oxytocin occurred 1 min after injection of 5 micrograms relaxin, iv, in angiotensin-II-antagonized rats, but the concentrations of both neuropeptides were significantly (P < 0.05) lower than those observed in the angiotensin-intact relaxin-treated controls. These data suggest that relaxin may act through the central angiotensin-II system to induce the release of vasopressin and oxytocin.


Assuntos
Angiotensina II/fisiologia , Encéfalo/fisiologia , Ocitocina/metabolismo , Relaxina/farmacologia , Vasopressinas/metabolismo , Anestesia , Animais , Feminino , Ratos , Ratos Sprague-Dawley , Relaxina/administração & dosagem
15.
Am J Clin Nutr ; 33(5): 1054-63, 1980 May.
Artigo em Inglês | MEDLINE | ID: mdl-6892752

RESUMO

The nutritional consequences of supplementary milk consumption by lactose-malabsorbing children were determined by nutrient balance studies. Twelve subjects received a marginally adequate rice and vegetable base-line diet alone and with simulated milk supplements containing either glucose or lactose during three separate balance periods. The diets were equally well accepted and tolerated. The children gained significantly more weight and had improved apparent nitrogen absorption and retention on the milk supplemented diets (P less than 0.001), and there was no difference between the effects of glucose milk and lactose milk. Fecal wet weights and energy and carbohydrate excretions were modestly increased with the lactose-containing diet, but not significantly so. It is suggested that low dose milk supplements can be well utilized when consumed by lactose malabsorbers in conjunction with other foods. Milk consumption need not be discouraged for populations among whom lactose malabsorption is widely prevalent, but milk should be provided in relatively low doses and the clinical responses to its consumption should be monitored.


Assuntos
Alimentos Formulados/normas , Intolerância à Lactose/metabolismo , Leite , Animais , Bangladesh , Peso Corporal , Metabolismo dos Carboidratos , Criança , Pré-Escolar , Dieta Vegetariana , Metabolismo Energético , Alimentos Fortificados , Motilidade Gastrointestinal , Glucose/farmacologia , Humanos , Absorção Intestinal , Lactose/farmacologia , Masculino
16.
Am J Clin Nutr ; 32(9): 1962-9, 1979 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-474486

RESUMO

The prevalence of lactose malabsorption (LM) among Bangladeshi village children has been determined using the recent developed breath hydrogen test. Initial hospital-based comparison studies showed general agreement between the breath hydrogen test and a modified lactose tolerance test. Two hundred thirty-four children, stratified by age, nutritional status, and history of recent diarrhea then participated in the field study. LM was diagnosed in more than 80% of children over 36 months of age but in none of the children under 6 months. Rates of LM were significantly increased in children with a history of recent diarrhea and a greater proportion of children in some age groups evidenced malabsorption in association with acute undernutrition. In the weanling age group children who were still breast feeding had a lower rate of LM than fully weaned subjects.


PIP: A study was conducted among 234 Bangladeshi children to determine LM (lactose malabsorption) and its relation with age, history of diarrhea, nutrition, and breastfeeding. LM was determined by using BHT (breath hydrogen test) which showed similar results to a modified lactose tolerance test conducted in hospitals. BHT results indicated that 80% of the children over 36 months had LM while all infants less than 6 months absorbed lactose completely. With recent incidences of diarrhea and acute malnutrition the rates of LM increased. In addition, children who were still breastfeeding had a lower rate of LM than weaned children perhaps since breastfed children suffer less from gastroenteritis and diarrhea or because some component of breast milk protects against LM. The United Nation's Protein Advisory Group encourages milk consumption but other reports cite increased mortality rates and slower recovery when malnourished children were supplied lactose-containing milk. It is suggested that milk be distributed in low doses in areas where there are high LM rates.


Assuntos
Aleitamento Materno , Fenômenos Fisiológicos da Nutrição Infantil , Fenômenos Fisiológicos da Nutrição do Lactente , Intolerância à Lactose/epidemiologia , Adolescente , Adulto , Fatores Etários , Bangladesh , Criança , Pré-Escolar , Diarreia/complicações , Diarreia/epidemiologia , Humanos , Lactente , Recém-Nascido , Intolerância à Lactose/complicações , População Rural
17.
J Endocrinol ; 122(3): 747-55, 1989 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2809482

RESUMO

Experiments were performed on anaesthetized, lactating rats to investigate the acute central actions of relaxin on blood pressure and vasopressin release. When compared with saline and control injections of isotonic protein extract, administration of relaxin into either the lateral or dorsal portion of the third ventricle caused a significant and sustained rise in arterial blood pressure. In contrast, relaxin administered to the ventral portion of the third ventricle caused only a short-term rise in blood pressure. Injections of relaxin into the fourth ventricle were without significant effect, suggesting that the central actions of relaxin on blood pressure are mediated by receptors restricted to the diencephalon or mesencephalon. A similar ventricular specificity was noted for the central relaxin-induced stimulation of vasopressin release as judged by concentrations of the hormone in the peripheral plasma. It is unlikely that the stimulation of vasopressin release is wholly responsible for the observed pressor effect observed. Lesion of the subfornical organ negated the pressor effect to relaxin injected into the dorsal region of the third ventricle, but did not affect the pressor response observed after injection of relaxin into the ventral portion of the third ventricle. These results demonstrate a biphasic action of centrally administered relaxin, with the response to dorsally placed third ventricle relaxin being mediated by the subfornical organ, and the response to ventral injections associated with an unknown structure of the ventral third ventricle wall.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Sistemas Neurossecretores/fisiologia , Relaxina/farmacologia , Órgão Subfornical/fisiologia , Animais , Feminino , Injeções Intraventriculares , Ratos , Ratos Endogâmicos , Relaxina/administração & dosagem , Fatores de Tempo , Vasopressinas/sangue
18.
Chest ; 116(1): 52-8, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10424503

RESUMO

STUDY OBJECTIVE: To compare lung function in infants exposed to maternal smoking with lung function in infants with a family history of asthma. There are no published studies comparing lung function in both groups. DESIGN: Cross-sectional study. SETTING: A tertiary pulmonary care center at a children's hospital. PATIENTS: One hundred five infants with daily wheezing. Thirty-five infants had persistent exposure to maternal smoking, and 70 had a family history of asthma in parents or siblings. MEASUREMENTS: Infant pulmonary function tests were compared between the two groups. The ratio of terminal to peak expiratory flow at tidal breathing at 25% of the previous expiration remaining and the ratio of terminal to peak expiratory flow with forced expiration at 25% of the previous expiration remaining (FEF25/PFEF) were used to evaluate peripheral airflow. A > 25% improvement in FEF25/PFEF after a bronchodilator challenge test was considered a positive response. RESULTS: Most infants in both groups had evidence of peripheral airflow obstruction with forced expiration. In infants exposed to maternal smoking, only 4 of 35 (11.4%) responded to a bronchodilator, compared to 51 of 70 (72.9%) in the group with a family history of asthma (p < 0.0005). There was no statistically significant difference in total respiratory system compliance, total respiratory system resistance, tidal volume, and degree of peripheral airflow obstruction at tidal breathing or after forced expiration in both groups. CONCLUSION: Infants with exposure to maternal smoking and infants with a family history of asthma have altered lung function, and a positive response to a bronchodilator is one variable that seems to differentiate the two groups.


Assuntos
Asma/genética , Sons Respiratórios/fisiopatologia , Poluição por Fumaça de Tabaco/efeitos adversos , Resistência das Vias Respiratórias , Testes de Provocação Brônquica , Estudos Transversais , Feminino , Predisposição Genética para Doença , Humanos , Lactente , Masculino , Testes de Função Respiratória
19.
J Neuroendocrinol ; 16(4): 398-402, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15089981

RESUMO

The oxytocin receptor is an important contractile-associated protein, up-regulated at term in the myometrium in many mammalian species. We conducted studies in a novel animal model to challenge the general view that gonadal steroids are a major regulatory factor of uterine oxytocin receptors. Female marsupials have separate uteri and, in monovular species such as the tammar wallaby, the conceptus is present in one uterus whereas the contralateral uterus is empty. A marked increase in myometrial oxytocin receptors occurs only in the gravid uterus. Fetectomy experiments demonstrated that local embryo-derived factors stimulate this gravid uterus-specific increase in oxytocin receptors, and that uterine distension is probably not a key component in this regulatory pathway. Unilateral ovariectomy has no significant effect on uterine oxytocin receptors, emphasizing the impact of the conceptus on oxytocin receptor regulation and the minimal influence of gonadal steroids on parturition in this species. Our data highlight that regulation of uterine oxytocin receptor expression is multifactorial, and does not necessarily rely on gonadal steroids.


Assuntos
Estrogênios/metabolismo , Macropodidae/metabolismo , Progesterona/metabolismo , Receptores de Ocitocina/metabolismo , Útero/metabolismo , Animais , Feminino
20.
J Neuroendocrinol ; 9(10): 777-87, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9355047

RESUMO

This study focuses on the structure and expression of the mesotocin (MT) gene in the chicken hypothalamus. Using an anchored and nested RT-PCR strategy, combined with circular RACE-PCR, the full length sequence of the chicken MT cDNA was obtained. The cDNA and derived amino acid sequences conformed to the structure of the oxytocin-like gene family. However, unlike most mammalian species, there does not appear to be frequent gene conversion between the MT and AVT cDNA sequences. A single specific hybridization signal of 1.2 kb was detected by Southern analysis of chicken genomic DNA, indicating only a single gene copy in the chicken genome. Northern analysis of hypothalamic RNA revealed a single band at approximately 0.6 kb. Using the same probe for in situ hybridization histochemistry, MT-mRNA was demonstrated to be predominantly localized in the parvocellular, magnocellular and periventricular subgroups of the paraventricular nucleus and, when compared to the distribution of neurons containing arginine-vasotocin (AVT)-mRNA in the same region, with far fewer neurons expressing the MT gene in the lateral subgroups. Only few and scattered neurons expressing the MT gene were found in the ventral and external subgroups of the supraoptic nucleus in which many neurons contain AVT transcripts, as demonstrated in consecutive sections. In all nuclei investigated, the intensity of AVT and MT hybridization signals per cell was approximately equal. No specific labelling for MT-mRNA was found in the bed nucleus of the stria terminalis, nor the nucleus accumbens. Using immunocytochemical detection of AVT and in situ hybridization for neurons expressing MT-mRNA, some neurons were found to contain both AVT and MT gene products in the paraventricular nucleus but not in the supraoptic nucleus.


Assuntos
DNA Complementar/genética , DNA Complementar/metabolismo , Diencéfalo/metabolismo , Hipotálamo/citologia , Hipotálamo/metabolismo , Neurônios/metabolismo , Ocitocina/análogos & derivados , Sequência de Aminoácidos , Animais , Sequência de Bases , Galinhas , Clonagem Molecular , Feminino , Expressão Gênica , Histocitoquímica , Hibridização In Situ , Masculino , Dados de Sequência Molecular , Neurofisinas/biossíntese , Neurofisinas/genética , Ocitocina/biossíntese , Ocitocina/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Homologia de Sequência do Ácido Nucleico , Vasotocina/análise
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