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1.
Nurse Educ Pract ; 71: 103719, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37523997

RESUMO

AIM: This study aimed to determine the attitude of Australian nursing lecturers to the use of technology applied to the teaching and learning of nursing students. BACKGROUND: The use of technology in teaching was accelerated in reaction to the COVID-19 restrictions whereby measures, including social distancing and lockdowns, forced many higher education courses to transition online. Lecturers play a key role in the integration of technology in teaching, as it is the lecturer, not the technology, who facilitates the students' learning experience. DESIGN: A cross sectional survey design was used for this study, distributed from April to June of 2022. The purpose of the survey was to gather technology readiness data (via the TRI 2 questions) and descriptive data representative of the nursing academic population in Australia. RESULTS: There was no statistically significant differences between participants based on demographic data (such as gender or age). There was an association between TRI 2 score and: the sum of elearning technologies engaged with; the frequency of engagement with technology and self-rated confidence with elearning. Of note were statistically significant differences of TRI between states/territories. Finally, there was an inverse relationship between the impact of COVID-19 restrictions and TRI 2 score. CONCLUSION: The study found that there was significant variation between states/territories and self-reported impact of TRI. Given that increased frequency and increased number of technologies engaged with are associated with technology readiness the variation between states/territories lockdowns which required engagement with technology, may have had an impact on the nursing academics attitude to technology. Importantly, this study found those who were highly technology ready found COVID-19 restrictions had less impact on them, suggesting that technology readiness may have assisted their transition to online learning.


Assuntos
COVID-19 , Estudantes de Enfermagem , Humanos , COVID-19/epidemiologia , Estudos Transversais , Austrália , Controle de Doenças Transmissíveis , Atitude
2.
Int J Nurs Educ Scholarsh ; 19(1)2022 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-35689794

RESUMO

Anatomy and Physiology (A&P) courses in undergraduate nursing programs are often considered challenging for students. Typically, a wide variety of teaching strategies, including dissection, experiments, illustrations and photographs are used to engage students. This study aimed to explore and describe the learning experiences of an open creative assessment task on undergraduate nursing students of learning A&P. A total of eight students participated in semi-structured interviews. Two major themes emerged from the data, this included 'Bringing A&P to life' which included two sub-themes of 'Learning through peer teaching' and 'An easy way to learn', with the second major theme, 'Custom made learning' which included four sub-themes, 'To grade or not to grade', 'Catering for different learning styles', 'Logistics of group work', and 'Effect of group dynamics'. This qualitative exploratory study contributes to further pedagogical insights into art and/or creative approaches to teaching.


Assuntos
Bacharelado em Enfermagem , Estudantes de Enfermagem , Currículo , Humanos , Aprendizagem , Pesquisa Qualitativa
3.
Comput Inform Nurs ; 40(4): 278-284, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34740220

RESUMO

The COVID-19 global pandemic caused major disruptions to the delivery of human Anatomy and Physiology courses to nursing students worldwide. The aim of the current study is to evaluate nursing students' experiences and perceptions of transitioning from a blended to a purely online study mode for first year Anatomy and Physiology courses during the global pandemic. Qualitative and quantitative methodologies were used with a sample of undergraduate nursing students enrolled at a regional Australian university across its three campuses. Descriptive statistical analysis was used to describe the study population. Content analysis was used to evaluate the participants' use of resources, experiences, and preferences in studying anatomy and physiology. There were 101 participants recruited in the study. Results indicated that face-to-face study mode (41.86%) was the preferred method of delivery during the global pandemic and participants were having a renewed appreciation for the blended study mode (38.37%). Online study mode was the least preferred (19.77%), with the participants' opinions of this mode of study not altered by the global pandemic. Although the COVID-19 global pandemic shifted the traditional teaching of anatomy and physiology in nursing programs to an online environment, the long-term impacts of this disruption have yet to be ascertained.


Assuntos
COVID-19 , Bacharelado em Enfermagem , Estudantes de Enfermagem , Austrália , Humanos , Pandemias
4.
Clin Exp Pharmacol Physiol ; 43(10): 896-905, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27385644

RESUMO

We determined whether adenine-induced chronic kidney disease (CKD) in rats is associated with renal tissue hypoxia. Adenine (100 mg) or its vehicle was administered to male Sprague-Dawley rats, daily by oral gavage, over a 15-day period. Renal function was assessed before, and 7 and 14 days after, adenine treatment commenced, by collection of a 24-hour urine sample and a blood sample from the tail vein. On day 15, arterial pressure was measured in conscious rats via the tail artery. Renal tissue hypoxia was then assessed by pimonidazole adduct immunohistochemistry and fibrosis was assessed by staining tissue with picrosirius red and Masson's trichrome. CKD was evident within 7 days of commencing adenine treatment, as demonstrated by increased urinary albumin to creatinine ratio (30 ± 12-fold). By day 14 of adenine treatment plasma creatinine concentration was more than 7-fold greater, and plasma urea more than 5-fold greater, than their baseline levels. On day 15, adenine-treated rats had slightly elevated mean arterial pressure (8 mmHg), anaemia and renomegaly. Kidneys of adenine-treated rats were characterised by the presence of tubular casts, dilated tubules, expansion of the interstitial space, accumulation of collagen, and tubulointerstitial hypoxia. Pimonidazole staining (hypoxia) co-localised with fibrosis and was present in both patent and occluded tubules. We conclude that renal tissue hypoxia develops rapidly in adenine-induced CKD. This model, therefore, should prove useful for examination of the temporal and spatial relationships between tubulointerstitial hypoxia and the development of CKD, and thus the testing of the 'chronic hypoxia hypothesis'.


Assuntos
Adenina/toxicidade , Rim/metabolismo , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/urina , Animais , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/fisiologia , Rim/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley , Insuficiência Renal Crônica/induzido quimicamente
5.
Am J Physiol Regul Integr Comp Physiol ; 311(3): R532-44, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27385734

RESUMO

Oxygen tension (Po2) of urine in the bladder could be used to monitor risk of acute kidney injury if it varies with medullary Po2 Therefore, we examined this relationship and characterized oxygen diffusion across walls of the ureter and bladder in anesthetized rabbits. A computational model was then developed to predict medullary Po2 from bladder urine Po2 Both intravenous infusion of [Phe(2),Ile(3),Orn(8)]-vasopressin and infusion of N(G)-nitro-l-arginine reduced urinary Po2 and medullary Po2 (8-17%), yet had opposite effects on renal blood flow and urine flow. Changes in bladder urine Po2 during these stimuli correlated strongly with changes in medullary Po2 (within-rabbit r(2) = 0.87-0.90). Differences in the Po2 of saline infused into the ureter close to the kidney could be detected in the bladder, although this was diminished at lesser ureteric flow. Diffusion of oxygen across the wall of the bladder was very slow, so it was not considered in the computational model. The model predicts Po2 in the pelvic ureter (presumed to reflect medullary Po2) from known values of bladder urine Po2, urine flow, and arterial Po2 Simulations suggest that, across a physiological range of urine flow in anesthetized rabbits (0.1-0.5 ml/min for a single kidney), a change in bladder urine Po2 explains 10-50% of the change in pelvic urine/medullary Po2 Thus, it is possible to infer changes in medullary Po2 from changes in urinary Po2, so urinary Po2 may have utility as a real-time biomarker of risk of acute kidney injury.


Assuntos
Testes de Função Renal/métodos , Medula Renal/metabolismo , Modelos Biológicos , Oxigênio/urina , Bexiga Urinária/metabolismo , Micção/fisiologia , Animais , Simulação por Computador , Oxigênio/sangue , Coelhos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
Am J Physiol Regul Integr Comp Physiol ; 307(10): R1207-15, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25209412

RESUMO

Renal tissue oxygen tension (PO2) and its determinants have not been quantified in polycystic kidney disease (PKD). Therefore, we measured kidney tissue PO2 in the Lewis rat model of PKD (LPK) and in Lewis control rats. We also determined the relative contributions of altered renal oxygen delivery and consumption to renal tissue hypoxia in LPK rats. PO2 of the superficial cortex of 11- to 13-wk-old LPK rats, measured by Clark electrode with the rat under anesthesia, was higher within the cysts (32.8 ± 4.0 mmHg) than the superficial cortical parenchyma (18.3 ± 3.5 mmHg). PO2 in the superficial cortical parenchyma of Lewis rats was 2.5-fold greater (46.0 ± 3.1 mmHg) than in LPK rats. At each depth below the cortical surface, tissue PO2 in LPK rats was approximately half that in Lewis rats. Renal blood flow was 60% less in LPK than in Lewis rats, and arterial hemoglobin concentration was 57% less, so renal oxygen delivery was 78% less. Renal venous PO2 was 38% less in LPK than Lewis rats. Sodium reabsorption was 98% less in LPK than Lewis rats, but renal oxygen consumption did not significantly differ between the two groups. Thus, in this model of PKD, kidney tissue is severely hypoxic, at least partly because of deficient renal oxygen delivery. Nevertheless, the observation of similar renal oxygen consumption, despite markedly less sodium reabsorption, in the kidneys of LPK compared with Lewis rats, indicates the presence of inappropriately high oxygen consumption in the polycystic kidney.


Assuntos
Hipóxia/sangue , Rim/metabolismo , Oxigênio/sangue , Doenças Renais Policísticas/sangue , Animais , Hipóxia Celular , Modelos Animais de Doenças , Hemodinâmica , Hipóxia/fisiopatologia , Rim/irrigação sanguínea , Masculino , Consumo de Oxigênio , Pressão Parcial , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/fisiopatologia , Ratos Endogâmicos Lew , Circulação Renal , Reabsorção Renal , Sódio/sangue
7.
Am J Physiol Endocrinol Metab ; 306(12): E1367-77, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24760990

RESUMO

Impaired coupling of adipose tissue expansion and vascularization is proposed to lead to adipocyte hypoxia and inflammation, which in turn contributes to systemic metabolic derangements. Pigment epithelium-derived factor (PEDF) is a powerful antiangiogenic factor that is secreted by adipocytes, elevated in obesity, and implicated in the development of insulin resistance. We explored the angiogenic and metabolic role of adipose-derived PEDF through in vivo studies of mice with overexpression of PEDF in adipocytes (PEDF-aP2). PEDF expression in white adipocytes and PEDF secretion from adipose tissue was increased in transgenic mice, but circulating levels of PEDF were not increased. Overexpression of PEDF did not alter vascularization, the partial pressure of O2, cellular hypoxia, or gene expression of inflammatory markers in adipose tissue. Energy expenditure and metabolic substrate utilization, body mass, and adiposity were not altered in PEDF-aP2 mice. Whole body glycemic control was normal as assessed by glucose and insulin tolerance tests, and adipocyte-specific glucose uptake was unaffected by PEDF overexpression. Adipocyte lipolysis was increased in PEDF-aP2 mice and associated with increased adipose triglyceride lipase and decreased perilipin 1 expression. Experiments conducted in mice rendered obese by high-fat feeding showed no differences between PEDF-aP2 and wild-type mice for body mass, adiposity, whole body energy expenditure, glucose tolerance, or adipose tissue oxygenation. Together, these data indicate that adipocyte-generated PEDF enhances lipolysis but question the role of PEDF as a major antiangiogenic or proinflammatory mediator in adipose tissue in vivo.


Assuntos
Tecido Adiposo Branco/metabolismo , Adiposidade , Proteínas do Olho/metabolismo , Resistência à Insulina , Metabolismo dos Lipídeos , Neovascularização Fisiológica , Fatores de Crescimento Neural/metabolismo , Serpinas/metabolismo , Regulação para Cima , Tecido Adiposo Branco/irrigação sanguínea , Tecido Adiposo Branco/crescimento & desenvolvimento , Animais , Glicemia/análise , Proteínas de Transporte/metabolismo , Hipóxia Celular , Dieta Hiperlipídica/efeitos adversos , Proteínas do Olho/sangue , Proteínas do Olho/genética , Humanos , Insulina/sangue , Lipase/metabolismo , Lipólise , Masculino , Camundongos , Camundongos Transgênicos , Fatores de Crescimento Neural/sangue , Fatores de Crescimento Neural/genética , Obesidade/sangue , Obesidade/etiologia , Obesidade/metabolismo , Perilipina-1 , Fosfoproteínas/metabolismo , Proteínas Recombinantes/sangue , Proteínas Recombinantes/metabolismo , Serpinas/sangue , Serpinas/genética , Aumento de Peso
8.
Am J Physiol Renal Physiol ; 306(9): F1026-38, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24598805

RESUMO

Tissue hypoxia has been demonstrated, in both the renal cortex and medulla, during the acute phase of reperfusion after ischemia induced by occlusion of the aorta upstream from the kidney. However, there are also recent clinical observations indicating relatively well preserved oxygenation in the nonfunctional transplanted kidney. To test whether severe acute kidney injury can occur in the absence of widespread renal tissue hypoxia, we measured cortical and inner medullary tissue Po2 as well as total renal O2 delivery (Do2) and O2 consumption (Vo2) during the first 2 h of reperfusion after 60 min of occlusion of the renal artery in anesthetized rats. To perform this experiment, we used a new method for measuring kidney Do2 and Vo2 that relies on implantation of fluorescence optodes in the femoral artery and renal vein. We were unable to detect reductions in renal cortical or inner medullary tissue Po2 during reperfusion after ischemia localized to the kidney. This is likely explained by the observation that Vo2 (-57%) was reduced by at least as much as Do2 (-45%), due to a large reduction in glomerular filtration (-94%). However, localized tissue hypoxia, as evidence by pimonidazole adduct immunohistochemistry, was detected in kidneys subjected to ischemia and reperfusion, particularly in, but not exclusive to, the outer medulla. Thus, cellular hypoxia, particularly in the outer medulla, may still be present during reperfusion even when reductions in tissue Po2 are not detected in the cortex or inner medulla.


Assuntos
Injúria Renal Aguda/metabolismo , Rim/metabolismo , Consumo de Oxigênio , Oxigênio/metabolismo , Traumatismo por Reperfusão/metabolismo , Injúria Renal Aguda/patologia , Injúria Renal Aguda/fisiopatologia , Animais , Biomarcadores/metabolismo , Hipóxia Celular , Modelos Animais de Doenças , Fluorescência , Taxa de Filtração Glomerular , Hemoglobinas/metabolismo , Imuno-Histoquímica , Rim/irrigação sanguínea , Rim/patologia , Rim/fisiopatologia , Fluxometria por Laser-Doppler , Masculino , Modelos Cardiovasculares , Nitroimidazóis/metabolismo , Ratos , Ratos Sprague-Dawley , Circulação Renal , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Fatores de Tempo
9.
Am J Physiol Renal Physiol ; 304(12): F1471-80, 2013 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-23576638

RESUMO

The precise roles of hypoxia in the initiation and progression of kidney disease remain unresolved. A major technical limitation has been the absence of methods allowing long-term measurement of kidney tissue oxygen tension (Po2) in unrestrained animals. We developed a telemetric method for the measurement of kidney tissue Po2 in unrestrained rats, using carbon paste electrodes (CPEs). After acute implantation in anesthetized rats, tissue Po2 measured by CPE-telemetry in the inner cortex and medulla was in close agreement with that provided by the "gold standard" Clark electrode. The CPE-telemetry system could detect small changes in renal tissue Po2 evoked by mild hypoxemia. In unanesthetized rats, CPE-telemetry provided stable measurements of medullary tissue Po2 over days 5-19 after implantation. It also provided reproducible responses to systemic hypoxia and hyperoxia over this time period. There was little evidence of fibrosis or scarring after 3 wk of electrode implantation. However, because medullary Po2 measured by CPE-telemetry was greater than that documented from previous studies in anesthetized animals, this method is presently best suited for monitoring relative changes rather than absolute values. Nevertheless, this new technology provides, for the first time, the opportunity to examine the temporal relationships between tissue hypoxia and the progression of renal disease.


Assuntos
Eletrodos Implantados , Rim/química , Oxigênio/análise , Telemetria/métodos , Animais , Gasometria , Carbono , Estado de Consciência , Masculino , Pressão Parcial , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Telemetria/instrumentação
10.
Clin Exp Pharmacol Physiol ; 39(11): 917-29, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23006058

RESUMO

In the present study, we tested whether polycystic kidney disease (PKD) is associated with renal tissue hypoxia and oxidative stress, which, in turn, contribute to the progression of cystic disease and hypertension. Lewis polycystic kidney (LPK) rats and Lewis control (Lewis) rats were treated with tempol (1 mmol/L in drinking water) from 3 to 13 weeks of age or remained untreated. The LPK rats developed polyuria, uraemia and proteinuria. At 13 weeks of age, LPK rats had greater mean arterial pressure (1.5-fold), kidney weight (sixfold) and plasma creatinine (3.5-fold) than Lewis rats. Kidneys from LPK rats were cystic and fibrotic. Renal hypoxia was evidenced by staining for pimonidazole adducts and hypoxia-inducible factor (HIF)-1α in cells lining renal cysts and upregulation of HIF-1α and its downstream targets vascular endothelial growth factor (VEGF), glucose transporter-1 (Glut-1) and heme oxygenase 1 (HO-1). However, total HO activity did not differ greatly between kidney tissue from LPK compared with Lewis rats. Renal oxidative and/or nitrosative stress was evidenced by ninefold greater immunofluorescence for 3-nitrotyrosine in kidney tissue from LPK compared with Lewis rats and a > 10-fold upregulation of mRNA for p47phox and gp91phox. Total renal superoxide dismutase (SOD) activity was sevenfold less and expression of SOD1 mRNA was 70% less in kidney tissue from LPK compared with Lewis rats. In LPK rats, tempol treatment reduced immunofluorescence for 3-nitrotyrosine and HIF1A mRNA while upregulating VEGF and p47phox mRNA expression, but otherwise had little impact on disease progression, renal tissue hypoxia or hypertension. Our findings do not support the hypothesis that oxidative stress drives hypoxia and disease progression in PKD.


Assuntos
Óxidos N-Cíclicos/farmacologia , Nefropatias/tratamento farmacológico , Nefropatias/patologia , Doenças Renais Policísticas/tratamento farmacológico , Doenças Renais Policísticas/patologia , Animais , Pressão Arterial/efeitos dos fármacos , Pressão Arterial/genética , Hipóxia Celular/efeitos dos fármacos , Creatinina/sangue , Progressão da Doença , Transportador de Glucose Tipo 1/genética , Transportador de Glucose Tipo 1/metabolismo , Heme Oxigenase (Desciclizante)/genética , Heme Oxigenase (Desciclizante)/metabolismo , Hemodinâmica/efeitos dos fármacos , Hemodinâmica/genética , Hipertensão/tratamento farmacológico , Hipertensão/genética , Hipertensão/metabolismo , Hipertensão/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Nefropatias/genética , Nefropatias/metabolismo , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , NADPH Oxidase 2 , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/metabolismo , Ratos , Ratos Endogâmicos Lew , Marcadores de Spin , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1 , Tirosina/análogos & derivados , Tirosina/genética , Tirosina/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
11.
Am J Physiol Renal Physiol ; 303(5): F605-18, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22674022

RESUMO

To understand how geometric factors affect arterial-to-venous (AV) oxygen shunting, a mathematical model of diffusive oxygen transport in the renal cortex was developed. Preglomerular vascular geometry was investigated using light microscopy (providing vein shape, AV separation, and capillary density near arteries) and published micro-computed tomography (CT) data (providing vessel size and AV separation; Nordsletten DA, Blackett S, Bentley MD, Ritman EL, Smith NP. IUPS Physiome Project. http://www.physiome.org.nz/publications/nordsletten_blackett_ritman_bentley_smith_2005/folder_contents). A "U-shaped" relationship was observed between the arterial radius and the distance between the arterial and venous lumens. Veins were found to partially wrap around the artery more consistently for larger rather than smaller arteries. Intrarenal arteries were surrounded by an area of fibrous tissue, lacking capillaries, the thickness of which increased from ∼5 µm for the smallest arteries (<16-µm diameter) to ∼20 µm for the largest arteries (>200-µm diameter). Capillary density was greater near smaller arteries than larger arteries. No capillaries were observed between wrapped AV vessel pairs. The computational model comprised a single AV pair in cross section. Geometric parameters critical in renal oxygen transport were altered according to variations observed by CT and light microscopy. Lumen separation and wrapping of the vein around the artery were found to be the critical geometric factors determining the amount of oxygen shunted between AV pairs. AV oxygen shunting increases both as lumen separation decreases and as the degree of wrapping increases. The model also predicts that capillaries not only deliver oxygen, but can also remove oxygen from the cortical parenchyma close to an AV pair. Thus the presence of oxygen sinks (capillaries or tubules) near arteries would reduce the effectiveness of AV oxygen shunting. Collectively, these data suggest that AV oxygen shunting would be favored in larger vessels common to the cortical and medullary circulations (i.e., arcuate and proximal interlobular arteries) rather than the smaller vessels specific to the cortical circulation (distal interlobular arteries and afferent arterioles).


Assuntos
Rim/irrigação sanguínea , Modelos Cardiovasculares , Oxigênio/metabolismo , Circulação Renal , Animais , Simulação por Computador , Feminino , Rim/anatomia & histologia , Masculino , Pressão Parcial
12.
J Vis Exp ; (35)2010 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-20062000

RESUMO

Undecalcified bone histology demonstrates the micro-architecture of bone. It shows both the mineralised and cellular components of bone, which provides vital information on bone turnover or bone formation and resorption. This has tremendous importance in a variety of clinical and research applications. It yields beautiful images and allows for techniques such as fluorochrome assessment and histomorphometry. Fluorochrome analysis is a technique where fluorescent dyes that bind to calcium are injected at a particular time point, which allows for quantification of the amount of mineralisation at that given time. Histomorphometry is a process of bone quantification at the microscopic level. Performing undecalcified bone histology is technically challenging, particularly with large size specimens. It requires variations in technique from those used in standard paraffin embedded histology. This video illustrates the process of producing good quality sections and demonstrates the technical difficulties and methods with which to overcome them. Specimen preparation, fixation and processing are achieved with a manner similar to other soft tissues, however due to the density and lower permeability of bone considerably longer fixation and processing times are required, often taking several weeks. Embedding is achieved using a supporting medium with similar or equal hardness and density to the bone such as methacrylate- based resins, but unlike paraffin infiltration and embedding, this is an irreversible step. Sectioning can be achieved by grinding which produces a thicker section, which is optimal for studies such as fluorochrome analysis. This is best achieved using a diamond blade on a macrotome. Alternatively, thinner sections can be produced for light microscopy and this is achieved using a sledge microtome with a very sharp blade. The sledge microtome provides the additional strength and stability required for large, hard blocks. Resin embedded sections can be stained with a variety of stains, which are demonstrated.


Assuntos
Osso e Ossos/química , Técnica de Descalcificação/métodos , Corantes Fluorescentes/química , Osso e Ossos/anatomia & histologia , Metacrilatos/química
13.
Hypertension ; 54(4): 852-9, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19667247

RESUMO

Early studies indicate that the hypertension observed in the Schlager inbred mouse strain may be attributed to a neurogenic mechanism. In this study, we examined the contribution of the sympathetic nervous system in maintaining hypertension in the BPH/2J mouse and used c-Fos immunohistochemistry to elucidate whether neuronal activation in specific brain regions was associated with waking blood pressure. Male hypertensive (BPH/2J; n=14), normotensive (BPN/3J; n=18), and C57/Bl6 (n=5) mice were implanted with telemetry devices, and after 10 days of recovery, recordings of blood pressure, heart rate, and locomotor activity were measured to determine circadian variation. Mean arterial pressure was higher in BPH/2J than in BPN/3J or C57/Bl6 mice (P<0.001), and BPH/2J animals showed exaggerated day-night differences (17+/-2 versus 6+/-1 mm Hg in BPN/3J or +8+/-2 mm Hg in C57/Bl6 mice; P<0.001). Acute sympathetic blockade with pentolinium (7.5 mg/kg IP) during the active and inactive phases reduced blood pressure to comparable levels in BPH/2J and BPN/3J mice. The number of c-Fos-labeled cells was greater in the amygdala (+180%; P<0.01), paraventricular nucleus (+110%; P<0.001), and dorsomedial hypothalamus (+48%; P<0.001) in the active (hypertensive) phase in BPH/2J compared with BPN/3J mice. The level of neuronal activation was mostly similar in these regions in the inactive phase. Of all of the regions studied, neuronal activation in the medial amygdala, as detected by c-Fos, was highly correlated to mean arterial pressure (r=0.98). These findings indicate that the hypertension is largely attributable to sympathetic nervous system activity, possibly generated through greater levels of arousal regulated by neurons located in the medial amygdala.


Assuntos
Modelos Animais de Doenças , Hipertensão/genética , Hipertensão/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Tonsila do Cerebelo/metabolismo , Animais , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/genética , Pressão Sanguínea/fisiologia , Ritmo Circadiano/genética , Ritmo Circadiano/fisiologia , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/genética , Frequência Cardíaca/fisiologia , Hipotálamo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Atividade Motora/genética , Atividade Motora/fisiologia , Núcleo Hipotalâmico Paraventricular/metabolismo , Tartarato de Pentolínio/farmacologia , Proteínas Proto-Oncogênicas c-fos/metabolismo
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