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1.
Br J Anaesth ; 122(2): 263-268, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30686312

RESUMO

BACKGROUND: A vertical incision is recommended for cricothyroidotomy when the anatomy is impalpable, but no evidence-based guideline exists regarding optimum site or length. The Difficult Airway Society guidelines, which are based on expert opinion, recommend an 80-100 mm vertical caudad to cephalad incision in the extended neck position. However, the guidelines do not advise the incision commencement point. We sought to determine the minimum incision length and commencement point above the suprasternal notch required to ensure that the cricothyroid membrane would be accessible within its margins. METHODS: We measured using ultrasound, in 80 subjects (40 males and 40 females) without airway pathology, the distance between the suprasternal notch and the cricothyroid membrane, in the neutral and extended neck positions. We assessed the inclusion of the cricothyroid membrane within theoretical incisions of 0-100 mm in length made at 10 mm intervals above the suprasternal notch. RESULTS: In the 80 subjects, the distance ranged from 27 to 105 mm. Movement of the cricothyroid membrane on transition from the neutral to extended neck position varied from 15 mm caudad to 27 mm cephalad. The minimum incision required in the extended position was 70 mm in males and 80 mm in females, commencing 30 mm above the suprasternal notch. CONCLUSIONS: An 80 mm incision commencing 30 mm above the suprasternal notch would include all cricothyroid membrane locations in the extended position in patients without airway pathology, which is in keeping with the Difficult Airway Society guidelines recommended incision length.


Assuntos
Cartilagem Cricoide/cirurgia , Serviços Médicos de Emergência/métodos , Tireoidectomia/métodos , Adolescente , Adulto , Idoso , Manuseio das Vias Aéreas , Cartilagem Cricoide/diagnóstico por imagem , Feminino , Guias como Assunto , Humanos , Masculino , Pessoa de Meia-Idade , Pescoço/diagnóstico por imagem , Pescoço/cirurgia , Palpação , Estudos Prospectivos , Caracteres Sexuais , Cartilagem Tireóidea/diagnóstico por imagem , Ultrassonografia , Adulto Jovem
2.
Ir Med J ; 111(8): 807, 2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-30547553

RESUMO

Aims We present a case of a five-year-old female admitted postoperatively to the Paediatric Critical Care Unit with a history of refractory seizures for which her parents were administering cannabis oil. Methods We discuss the issues surrounding cannabis prescription in Ireland and the role of parental autonomy in medication selection and administration. Results An administration regime was agreed upon following discussion with the child's parents. Conslusion While this case raised ethical and legal issues, we must also consider parental autonomy and their role as advocate for their child during admission to critical care.

3.
Int J Obstet Anesth ; 48: 103205, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34280884

RESUMO

BACKGROUND: During performance of emergency front of neck access, the final step in management algorithms for the 'can't intubate, can't oxygenate' scenario, accurate identification of the cricothyroid membrane is crucial. Accurate identification using palpation techniques is low, with highest failure rates occurring in obese females. METHODS: This prospective observational study recruited 28 obese obstetric patients. The cricothyroid membrane was identified using ultrasound, marked with an ultraviolet pen and covered with a dressing. The candidate was asked to perform cricothyroid membrane identification using landmark technique (group L) followed by ultrasound (group U). The primary outcome was the distance between the actual and estimated cricothyroid membrane midpoint. Secondary outcomes were the proportion of accurate assessments, time taken, and subjective ease of identification using a visual analogue score. RESULTS: Distance from the cricothyroid membrane midpoint was shorter in group U than Group L (2.5 mm vs 5.5 mm, P=0.002). The proportion of correctly identified cricothyroid membranes was greater in group U than group L (71% vs 39%, P=0.015). Time required for identification was shorter in group L than group U (16.9 s vs 23.5 s, P=0.001). Visual analogue scores for ease of identification were lower in group U than group L (2.4 cm vs 4.2 cm, P=0.013). CONCLUSIONS: Ultrasound-guided cricothyroid membrane localisation was significantly more accurate but slower than the landmark technique in obese obstetric patients. As such, we recommend the use of pre-procedural identification of the cricothyroid membrane in this patient population and formal training of anaesthetists in airway ultrasound.


Assuntos
Cartilagem Cricoide , Cartilagem Tireóidea , Manuseio das Vias Aéreas , Cartilagem Cricoide/diagnóstico por imagem , Feminino , Humanos , Obesidade/complicações , Palpação , Gravidez , Ultrassonografia
4.
Int J Obstet Anesth ; 36: 42-48, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30392652

RESUMO

BACKGROUND: Misidentification of the cricothyroid membrane is frequent in females, placing them at risk of difficult or failed cricothyroidotomy in the event of failed oxygenation. If anatomy is impalpable, the current guidelines of the Difficult Airway Society, based on expert opinion, recommend an 8-10 cm vertical incision to facilitate access to the cricothyroid membrane. At present no evidence-based guideline exists regarding optimum site or length. We investigated the likelihood of inclusion of the cricothyroid membrane, within hypothetical vertical midline incisions, in a female population. METHODS: We asked clinicians to identify the cricothyroid membrane in both the neutral and extended head positions using palpation, the point identified acting as the theoretical midpoint of a cricothyroidotomy incision. We then identified the cricothyroid membrane using ultrasound. We determined the minimum incision length that would be required to ensure that the cricothyroid membrane lay within its boundaries, if clinician digital palpation was the method of cricothyroid membrane localisation. RESULTS: Ninety female subjects were recruited. Theoretical incisions of 7 and 8 cm were required for successful cricothyroidotomy in the neutral and extended head positions respectively. This was necessary because of the high failure rate of cricothyroid membrane identification (80.9%) and the wide range of error (7.2 cm in a vertical plane). CONCLUSIONS: Based on clinical estimation of the location of the cricothyroid membrane, an incision length of 8 cm, using the clinician's best estimate as its midpoint, would overlie all cricothyroid membrane locations. Our data support the current Difficult Airway Society guidelines for cricothyroidotomy incision length.


Assuntos
Pesos e Medidas Corporais/métodos , Cartilagem Cricoide/cirurgia , Palpação/métodos , Cartilagem Tireóidea/cirurgia , Adulto , Feminino , Humanos
5.
Vet J ; 173(1): 109-17, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16314126

RESUMO

Copper (Cu) supplementation of dams in late gestation may be protective against articular cartilage abnormalities in foals. Articular cartilage was harvested from 22 Thoroughbred foals at 160 days of age, at sites predisposed to osteochondrosis (OC), and examined for evidence of early cartilage abnormalities and established dyschondroplastic (DCP) lesions to determine if there were any significant differences due to mare Cu supplementation by injection during late gestation, or foal liver Cu concentration. Cu supplemented mares received calcium Cu edetate injections in late gestation (250 mg at around 220, 248, 276 and 304 days gestation, then every two weeks until foaling). Foals were euthanased at 160 days of age and articular cartilage was harvested from four defined sites. Samples were examined for histological appearance of chondrocytes after staining with haematoxylin and eosin, and were also stained with toluidine blue to indicate proteoglycan content. Alkaline phosphatase (ALP) activity was detected by histochemistry, and histocytochemical techniques were used to determine the expression of cathepsin B. Cu supplementation of the dam, or liver Cu concentration of the foal at birth or 160 days of age had no statistically significant effect on the frequency of cartilage irregularities observed grossly, or abnormalities detected histologically at four defined sites. ALP expression was similar in all samples. Cathepsin B expression varied between sites, and was seen in chondrocyte clusters. The intensity of toludine blue staining varied between sites. Minor histological cartilage abnormalities were observed in cartilage from clinically normal animals. These abnormalities might be 'early' dyschondroplastic lesions, which could resolve or progress. The role of Cu in the development, resolution or progression of dyschondroplastic lesions is poorly understood.


Assuntos
Cobre/farmacologia , Doenças dos Cavalos/prevenção & controle , Osteocondrite/veterinária , Fenômenos Fisiológicos da Nutrição Pré-Natal , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/patologia , Cobre/análise , Dieta/veterinária , Suplementos Nutricionais , Feminino , Cavalos , Fígado/química , Masculino , Osteocondrite/prevenção & controle , Osteocondrodisplasias/prevenção & controle , Gravidez
6.
Genetics ; 139(3): 1383-91, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7768446

RESUMO

Three male F1 hybrids between Père David's deer and red deer were mated to red deer to produce 143 backcross calves. The pedigrees are a rare example of a fertile hybrid between evolutionarily divergent species. We examined the use of these families for genetic mapping of evolutionarily conserved (Type I) loci by testing for genetic linkage between five species-specific protein variants and 12 conserved DNA probes. Two probes were homologous, and the remainder syntenic, to the protein coding loci in cattle or humans. Using six restriction enzymes, each DNA probe detected one or more restriction fragments specific to Père David's deer. Linkage analyses among the species-specific variants placed the loci into four linkage groups within which linkage between adjacent loci and gene order was supported by a LOD > 3. The linkage groups were (HPX, HBB)-FSHB-ACP2, LDHA-CD5-IGF2, BMP3-(GC, ALB)-(KIT, PDGFRA) and LDLR-C3-FGF1. Southern and protein analysis of LDHA and ALB provided identical segregation data. These linkage groups were consistent with the cattle gene map and provide new information for comparing the gene maps of ruminants, humans and mice. The deer hybrids are an important new resource that can contribute to the comparative analysis of the mammalian genome.


Assuntos
Mapeamento Cromossômico , Cervos/genética , Hibridização Genética , Animais , Evolução Biológica , Sondas de DNA/genética , Feminino , Humanos , Masculino , Linhagem , Polimorfismo de Fragmento de Restrição , Especificidade da Espécie
7.
Anim Reprod Sci ; 88(3-4): 287-98, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16143218

RESUMO

Gonadotropin releasing-hormone analogue (buserelin) challenges were carried out every 8 weeks from 4 to 14 months of age on thoroughbred colts born in the spring (n = 6) or autumn (n = 5) to define the onset of puberty. In all colts, luteinizing hormone (LH) secretion followed a seasonal pattern, with high baseline and maximal concentrations in the spring and summer and low concentrations in the winter. Testosterone concentrations were undetectable before spring and, thus, autumn-born colts were younger than spring-born colts when a testosterone response to buserelin was first observed. Mean weights of the autumn-born colts were 300 kg (282-327 kg) at the time of the first detectable testosterone response in the following spring (October). Spring-born colts had reached this weight in the winter (May and June, before day length had increased) but did not exhibit a significant testosterone response until the spring at a mean weight of 352 kg (327-403 kg). It is proposed that colts must achieve a threshold body weight concurrently with stimulatory photoperiod for onset of puberty to occur.


Assuntos
Envelhecimento , Busserrelina/administração & dosagem , Cavalos , Hipófise/efeitos dos fármacos , Estações do Ano , Testículo/efeitos dos fármacos , Animais , Peso ao Nascer , Peso Corporal , Hormônio Liberador de Gonadotropina/análogos & derivados , Hormônio Luteinizante/sangue , Hormônio Luteinizante/metabolismo , Masculino , Fotoperíodo , Hipófise/fisiologia , Testículo/fisiologia , Testosterona/sangue
8.
Endocrinology ; 122(6): 3005-7, 1988 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3371270

RESUMO

We have previously shown that plasma IGF 1 concentration is positively correlated with the rate of antler growth and have proposed that IGF 1 is stimulatory for antler growth in the red deer stag. Therefore to partly resolve the question of whether the IGF 1 was of circulating or local origin in relation to its effect on antler growth, we surgically prevented stags from growing antlers. We recorded significantly elevated plasma levels of IGF 1 in the non-antlered stags compared with normal antlered stags during the antler growth periods. This result is consistent with a hypothesis that the antler is a target organ for IGF 1 and that prevention of antler growth removed a population of IGF 1 receptors. IGF 1 is already known to stimulate body growth but this work points strongly to the possibility that plasma IGF 1 may stimulate individual organ growth in an endocrine manner.


Assuntos
Chifres de Veado/crescimento & desenvolvimento , Cervos/fisiologia , Cornos/crescimento & desenvolvimento , Fator de Crescimento Insulin-Like I/sangue , Somatomedinas/sangue , Animais , Masculino , Estações do Ano
9.
Endocrinology ; 116(2): 846-8, 1985 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3881250

RESUMO

We have investigated the possibility that IGF-1 may play a role in the regulation of antler development. Plasma IGF-1 concentrations were measured throughout the first period of development of the pedicle and first antler of red deer (Cervus elaphus) to determine whether a relationship existed between growth of antler cartilage (velvet antler) and IGF-1. We report that plasma levels of IGF-1 are significantly elevated during the velvet antler growing phase relative to the other phases of pedicle and first antler development and a strong positive correlation exists between antler growth rate and circulating concentrations of IGF-1. As IGF-1 has been demonstrated to influence cartilage growth, we suggest that IGF-1 is a candidate as an antler stimulating hormone.


Assuntos
Chifres de Veado/crescimento & desenvolvimento , Cornos/crescimento & desenvolvimento , Insulina/fisiologia , Peptídeos/fisiologia , Somatomedinas/fisiologia , Animais , Cartilagem/crescimento & desenvolvimento , Cervos , Insulina/sangue , Masculino , Peptídeos/sangue , Somatomedinas/sangue , Fatores de Tempo
10.
Atherosclerosis ; 106(1): 29-41, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8018105

RESUMO

The aim of the study was to examine the effect of low doses of perindopril, approximating those used therapeutically and sub-therapeutically in human hypertensives, on the development of atherosclerosis in the cholesterol-fed rabbit. The right carotid artery of 12 week old rabbits was balloon de-endothelialized to induce the formation of a myointimal thickening. After 14 weeks rabbits were placed into 6 groups, 6 rabbits per group. Groups I, II and III were fed a 1% cholesterol diet for the following 6 week experimental period, while Groups IV, V and VI received a normolipemic diet. In addition, Groups II and V rabbits received in their drinking water 0.3 mg/kg per day perindopril, and Groups III and VI 0.01 mg/kg per day. At the end of 6 weeks' treatment, the mean arterial pressure (MAP) in Groups II and V decreased by about 12%, while that in Groups III and VI decreased by 13%. Plasma cholesterol levels of rabbits on a normolipemic diet (Groups IV, V, VI) averaged 1.3 mmol/l while those on a cholesterol-enriched diet (Groups I, II, III) averaged 10.5 mmol/l. Plasma perindoprilat concentrations and percentage of plasma angiotensin converting enzyme (ACE) inhibition in Groups II and V averaged 14 ng/ml and 92.1% respectively, while in Groups III and VI they were 5.7 ng/ml and 80.5%, respectively. The percentage luminal surface area of the thoracic aorta covered by lipid-filled plaques (as observed by en face staining with Oil-Red-O) averaged 26.3% in Group I, 4.7% in Group II and 20.0% in Group III. No lesions developed in Groups IV, V and VI. Microscopic examination of the right (manipulated) carotid arteries of Group I rabbits revealed lesions of large, lipid-filled cells radially oriented, overlying the pre-formed myointimal thickening. Both doses of perindopril in the cholesterol-fed rabbits (Groups II and III) decreased the amount of lipid-filled cells which were oriented circumferentially. More extracellular matrix was present in the lesions of Groups II and III than of Group I. No lesions were observed in the right carotid arteries of Groups IV, V and VI (normal diet) or in the unmanipulated left carotid arteries of all 6 groups. The sizes of the neointima plus lesion in Groups I, II and III were, however, not significantly different, being 42.4%, 48.5% and 46.9% of the cross-sectional area of the artery wall.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Arteriosclerose/prevenção & controle , Colesterol na Dieta/efeitos adversos , Indóis/farmacologia , Lipoproteínas/metabolismo , Músculo Liso Vascular/metabolismo , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Animais , Aorta Torácica/patologia , Arteriosclerose/etiologia , Arteriosclerose/patologia , Artérias Carótidas/patologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Colesterol na Dieta/administração & dosagem , Colágeno/biossíntese , Feminino , Indóis/administração & dosagem , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/patologia , Perindopril , Coelhos
11.
J Hypertens ; 17(4): 537-45, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10404956

RESUMO

BACKGROUND: We have demonstrated that accumulated macrophages in human coronary arteries strongly express angiotensin converting enzyme in accordance with the development of atheromatous plaques. However, there are few reports on the regulation of the renin-angiotensin system in macrophages and in monocytes as their source. OBJECTIVE: To examine whether the renin-angiotensin system is upregulated during the differentiation of monocytes to macrophages, and whether it is further regulated by angiotensin II and cytokines. MATERIALS AND METHODS: We used a human leukemia cell line, THP-1, for monocytes. Differentiated THP-1, induced by adding phorbol 12-myristate 13-acetate for 24 h, were used as macrophages. Expression of messenger RNA of the renin-angiotensin system components was measured by quantitative reverse-transcriptase polymerase chain reaction. Angiotensin converting enzyme activity and subtype-specific angiotensin-binding sites of cultured cells, and angiotensin II production in the culture medium were measured. RESULTS: Macrophages expressed all components of the renin-angiotensin system except chymase. Cellular angiotensin converting enzyme activity and angiotensin II in the medium were increased 3.2- and 4.5-fold during differentiation, respectively. Expression of angiotensin II type 1 (AT1) and type 2 (AT2) receptors was increased 6.2-and 6.4-fold during differentiation, and was sustained for 7 days. Incubation with angiotensin II for 24 h caused downregulation of both AT1 and AT2 receptor messenger RNA, but the expression levels were still more than threefold higher compared with monocytes. The density of binding sites of AT1 and AT2 receptors in macrophages was 0.26 +/- 0.02 and 0.15 +/- 0.01 fmol/10(6) cells, respectively. CONCLUSION: The renin-angiotensin system is markedly activated during monocyte/macrophage differentiation, and may participate in the development of atherosclerosis.


Assuntos
Macrófagos/citologia , Monócitos/citologia , Sistema Renina-Angiotensina/fisiologia , Angiotensina II/biossíntese , Angiotensina II/fisiologia , Arteriosclerose/metabolismo , Sítios de Ligação , Diferenciação Celular , Citocinas/biossíntese , Citocinas/fisiologia , Humanos , Peptidil Dipeptidase A/metabolismo , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/biossíntese , Receptores de Angiotensina/metabolismo , Sistema Renina-Angiotensina/genética , Células Tumorais Cultivadas , Regulação para Cima
12.
J Endocrinol ; 131(3): 467-74, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1783890

RESUMO

Blood samples were taken from six tame red deer stags at 3-15 months of age once a month from a jugular catheter every 30 min for 24 h to investigate hormonal secretion during puberty and during growth of the pedicle and first antler. All plasma samples were analysed for LH and testosterone concentrations and the resultant data were analysed using the PULSAR pulse detection routine. In addition each stag was injected wih gonadotrophin-releasing hormone (GnRH; 20 ng/kg body weight) after the above samples had been taken and the bleeding regimen was continued for a further 2 h. Body weight, antler size and status (i.e. whether the stags had a pedicle or antler) were also recorded. The pulsatile secretion of LH could be considered to have occurred in three phases. The first of these was one of development, with the LH pulse frequency increasing to 8 pulses/24 h, the second a phase of regression, with a decrease in LH pulse frequency to 2 pulses/24 h, and finally a second phase of development characterized by increased LH pulse frequency to 12 pulses/24 h. Testosterone secretion generally followed the same pattern. During the period before the permanent bony pedicles grew, there were less than five LH pulses/24 h. When the pedicles were growing, LH and testosterone pulsatile secretion increased but the pulse frequency of both hormones fell during velvet antler growth.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Chifres de Veado/crescimento & desenvolvimento , Cervos/sangue , Hormônio Luteinizante/sangue , Maturidade Sexual/fisiologia , Testosterona/sangue , Animais , Peso Corporal , Masculino , Tamanho do Órgão , Taxa Secretória/fisiologia , Testículo/anatomia & histologia , Fatores de Tempo
13.
J Endocrinol ; 117(1): 35-41, 1988 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3282020

RESUMO

Eight adult red deer stags were given an i.v. injection of synthetic gonadotrophin-releasing hormone (GnRH) on seven occasions at various stages of the antler cycle, namely hard antler in late winter, casting, mid-velvet growth, full velvet growth, antler cleaning and hard antler both during the rut and in mid-winter. The stags were allocated at random on each occasion to one of four doses, i.e. 1, 3, 10 or 95 micrograms GnRH. Blood samples were taken before GnRH injection and for up to 2 h after injection. Pituitary and testicular responses were recorded in terms of plasma LH and testosterone concentrations. There was an increase in plasma concentration of LH after the GnRH injection in all stags at all stages of the antler cycle. Dose-dependent responses of LH to GnRH in terms of area under the curve were apparent at all stages of the antler cycle. The lowest responses were recorded at casting, during velvet antler growth and at the rut sampling. The pattern of testosterone response reflected the inter-relationship of the antler and sexual cycles with very low testosterone responses occurring at casting and during velvet antler growth. The responses were higher at antler cleaning and then increased to a maximum at the rut before declining to reach their nadir at casting. The results are consistent with a hypothesis that the antler cycle, as a male secondary sexual characteristic, is closely linked to the sexual cycle and its timing is controlled by reproductive hormones. Low plasma concentrations of testosterone, even after LH stimulation, are consistent with the hypothesis that testosterone is unnecessary as an antler growth stimulant during growth.


Assuntos
Chifres de Veado/fisiologia , Cervos/fisiologia , Cornos/fisiologia , Hormônio Luteinizante/sangue , Hormônios Liberadores de Hormônios Hipofisários , Testosterona/sangue , Animais , Masculino , Periodicidade
14.
J Endocrinol ; 121(2): 351-60, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2754367

RESUMO

Plasma samples taken every 30 min over a 26-h period each month from six 4- to 15-month-old red deer stags were analysed for GH. In addition, two samples taken at 10.00 and 22.00 h were analysed for insulin-like growth factor-I (IGF-I) and insulin-like growth factor-II (IGF-II). A concentrate diet was available ad libitum. Food intake, body weight and antler status were recorded. Concentrations of GH were analysed using the PULSAR peak detection routine. Secretion of GH was pulsatile in every month of sampling, but the pattern of pulsatility differed seasonally. During the autumn and early winter (April-June in the Southern hemisphere) GH pulses were frequent and of low amplitude. In contrast, GH pulses in spring (August-September) were of high amplitude and high frequency resulting in a high mean level of GH circulating in the plasma. In early summer (November) the GH pulse amplitude was much lower and pulse frequency fell. There was a rise in GH pulse frequency not accompanied by an increase in GH pulse amplitude in summer (December-January). GH pulse amplitude seemed to be the main determinant of mean GH plasma level. Secretion of IGF-I was raised 1 month after peak monthly mean GH secretion. There was little consistent relationship between concentrations of IGF-II and mean daily GH. Concentrations of GH correlated positively and significantly with liveweight gain and antler growth rate with a delay of 1 month. Significantly positive correlations between concentrations of IGF-I, liveweight gain and antler growth rate were observed. It is considered that the spring and summer (September-December) seasonal acceleration of liveweight gain and antler development in stags could be a consequence of high winter/early spring (August-September) GH pulse frequency and amplitude resulting in increased concentrations of IGF-I, particularly in October.


Assuntos
Chifres de Veado/crescimento & desenvolvimento , Cervos/crescimento & desenvolvimento , Hormônio do Crescimento/sangue , Cornos/crescimento & desenvolvimento , Fator de Crescimento Insulin-Like II/sangue , Fator de Crescimento Insulin-Like I/sangue , Somatomedinas/sangue , Animais , Cervos/sangue , Ingestão de Alimentos , Masculino , Estações do Ano , Aumento de Peso
15.
Regul Pept ; 83(1): 25-30, 1999 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-10498341

RESUMO

Angiotensin IV, (V-Y-I-H-P-F), binds to AT4 receptors in blood vessels to induce vasodilatation and proliferation of cultured bovine endothelial cells. This latter effect may be important not only in developing tissues but also in injured vessels undergoing remodelling. In the present study, using normal rabbit carotid arteries, we detected AT4 receptors in vascular smooth muscle cells and in the vasa vasorum of the adventitia. Very low receptor levels were observed in the endothelial cells. In keeping with the described binding specificity of AT4 receptors, unlabelled angiotensin IV competed for [125I]angiotensin IV binding in the arteries, with an IC50 of 1.4 nM, whereas angiotensin II and angiotensin III were weaker competitors. Within the first week following endothelial denudation of the carotid artery by balloon catheter, AT4 receptor binding in the media increased to approximately 150% of control tissue. AT4 receptor binding further increased in the media, large neointima and re-endothelialized cell layer to 223% at 20 weeks after injury. In view of the known trophic effects of angiotensin IV, the elevated expression of AT4 receptors, in both the neointima and media of arteries, following balloon injury to the endothelium, suggests a role for the peptide in the adaptive response and remodelling of the vascular wall following damage.


Assuntos
Lesões das Artérias Carótidas/metabolismo , Artéria Carótida Primitiva/metabolismo , Receptores de Angiotensina/metabolismo , Angioplastia Coronária com Balão , Angiotensina II/análogos & derivados , Angiotensina II/metabolismo , Animais , Artéria Carótida Externa/metabolismo , Técnicas In Vitro , Masculino , Coelhos , Regulação para Cima
16.
Domest Anim Endocrinol ; 8(2): 323-9, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2070603

RESUMO

The aim of this study was to compare the ovine growth hormone (oGH) responses of 5 genetically lean and 5 genetically fat 9 month old ram lambs (selected on the basis of their ultrasonic backfat thickness) given two 0.3 micrograms kg-1 liveweight intravenous injections of synthetic human pancreatic GH releasing factor analogue Nle27 hGHRF29 -NH2 (GRF-29) 150 minutes apart. Plasma oGH response curves were analysed using an exponential 2 compartmental model and comparisons made through parallel curve analysis. Plasma oGH levels over 200 ng ml-1 were detected in response to GRF-29. Exponential model parameters indicated that lean lambs had a significantly higher rate of oGH release into the plasma after both consecutive GRF-29 injections, and a significantly lower rate of oGH clearance from the plasma after the second GRF-29 injection only. Significantly smaller peak oGH responses to the second GRF-29 injection were shown by the fat lambs. These results suggest that oGH release is impaired in genetically fat lambs and that either the synthesis of releasable oGH is reduced or the inhibitory tone is greater in the fat lambs. The lean and fat sheep may provide a useful model for the study of hormonal control of factors affecting leanness and fatness.


Assuntos
Hormônio Liberador de Hormônio do Crescimento/farmacologia , Hormônio do Crescimento/metabolismo , Obesidade/veterinária , Doenças dos Ovinos/metabolismo , Tecido Adiposo/anatomia & histologia , Análise de Variância , Animais , Biometria , Genótipo , Masculino , Obesidade/genética , Obesidade/metabolismo , Ovinos , Doenças dos Ovinos/genética
17.
Domest Anim Endocrinol ; 14(6): 381-90, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9437574

RESUMO

The effects of natural variation in the number of copies of the growth hormone (GH) gene on growth parameters, plasma GH profiles, and the response to GHRH challenge were compared in Coopworth ram lambs from selection lines differing in body composition and GH levels. Different genotypes at the GH locus carried two, three, or four copies of the GH gene and GH secretion was studied under ad libitum feeding conditions and in the fasted state. There were no significant effects of GH genotype on any parameters of growth or body composition. Basal serum GH concentration, GH pulse frequency, and GH pulse amplitude differed significantly with selection line and fasting, but did not differ significantly between the GH genotypes. Significant differences of subtle nature were found between the GH genotypes in their responsiveness to GHRH. For the ad libitum-fed Lean selection line animals, the first GHRH challenge resulted in a higher mean maximum response for GH1/GH1 than GH2/GH2 (P < 0.05). Between the first and the second challenges there was a decrease in maximum response for the GH1/GH1 genotype and an increase for the GH2/GH2 genotype (P < 0.05 for GH genotype main effect). The differences between GH genotypes in response to GHRH challenge suggest that polymorphism in the number of GH gene copies in sheep may have physiological implications for the function of the GH axis, which may be manifested in growing lambs only under specific genotype-environment combinations.


Assuntos
Variação Genética , Hormônio do Crescimento/genética , Ovinos/genética , Ovinos/fisiologia , Alelos , Animais , Composição Corporal , Frequência do Gene , Genótipo , Hormônio do Crescimento/sangue , Hormônio Liberador de Hormônio do Crescimento , Masculino , Aumento de Peso
18.
Theriogenology ; 61(6): 1051-60, 2004 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15036994

RESUMO

To determine the responsiveness of the pituitary-gonadal axis of peri-pubertal colts to GnRH, buserelin (0.5, 1, 5, 10 and 40 microg) was given to 13 male Thoroughbred yearlings ( n=3-8 colts per dose). Jugular venous blood samples were taken at -10, 0, 10, 20, 30, 40, 60, 120 and 180 min relative to buserelin administration. Increases (P < 0.05) in LH concentrations occurred in colts that received 5, 10, or 40 microg buserelin, but not in those that received 0.5 or 1 microg. Peak LH concentrations and mean area under the curve were higher (P < 0.05) in colts receiving 40 microg buserelin than in those that received 0.5 or 1 microg. Increases ( P< 0.05) in testosterone concentrations occurred in some, but not all, colts that received 1, 5, 10, or 40 microg buserelin. Neither peak concentration nor area under the curve of testosterone differed significantly among doses of buserelin. The percentage of horses that responded to the buserelin increased with increasing dose, with only the highest dose eliciting LH and testosterone responses in all colts. In conclusion, peri-pubertal colts exhibited a dose-response release of LH following buserelin treatment, but individual colts responded in an "all or nothing" manner, such that each either had an LH response or did not. Some colts that exhibited a significant LH response had no subsequent increase in plasma testosterone concentrations; perhaps the pituitary LH response may not have been great enough to stimulate the Leydig cells in these individuals.


Assuntos
Busserrelina/administração & dosagem , Cavalos/sangue , Hormônio Luteinizante/sangue , Testosterona/sangue , Animais , Relação Dose-Resposta a Droga , Cinética , Masculino
19.
Theriogenology ; 32(5): 877-83, 1989 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16726734

RESUMO

In two experiments, Red deer hinds were synchronized with intravaginal progesterone and were given 4 d of treatment (3 d before progesterone withdrawal and 1 d after) with an ovine follicle stimulating hormone (FSH) preparation which had a claimed low level of luteinizing hormone (LH) contamination. In Experiment 1, 12 hinds received one of four FSH levels by osmotic minipump. Hinds were run with fertile stags, and laparotomy and embryo recovery were performed 9 d after progesterone withdrawal. The ovulation rates (mean of three hinds per dosage) were 1.0, 2.0, 4.3 and 15.3 (number of corpora lutea counted) for estimated daily dosages rates of 0.036, 0.071, 0.11 and 0.14 units FSH preparation/day; the response to the increasing dosage was exponential (P<0.01). The recovery rate of ova on flushing was 38% (24 63 ), with all recovered ova being fertilized and of transferable quality. In Experiment 2, performed later in the breeding season, eight hinds received 0.14 units FSH/day either by minipump or by intramuscular injection. The mean ovulation rates were 3.0 and 11.0 (a significant difference, P<0.01), respectively, with a recovery rate of 72% (34 47 ), and with only 18 34 ova considered to be of transferable quality. The recovery rate in Experiment 2 was significantly higher than that in Experiment 1 (P<0.001). Overall, the results were better than those previously recorded for red deer, perhaps a function of both the FSH preparation used and an improved progesterone profile in estrus synchronization.

20.
Artigo em Inglês | MEDLINE | ID: mdl-11716797

RESUMO

BACKGROUND: The specificity of clinical questions is gauged by explicit descriptions of four dimensions: subjects, interventions, comparators and outcomes of interest. This study determined whether adding simple instructions and examples on clinical question formulation would increase the specificity of the submitted question compared to using a standard form without instructions and examples. METHODS: A randomised controlled trial was conducted in an evidence-search and appraisal service. New participants were invited to reformulate clinical queries. The Control Group was given no instructions. The Intervention Group was given a brief explanation of proper formulation, written instructions, and diagrammatic examples. The primary outcome was the change in the proportion of reformulated questions that described each the dimensions of specificity. RESULTS: Fifty-two subjects agreed to participate in the trial of which 13 were lost to follow-up. The remaining 17 Intervention Group and 22 Control Group participants were analysed. Baseline characteristics were comparable. Overall, 20% of initially submitted questions from both groups were properly specified (defined as an explicit statement describing all dimensions of specificity). On follow-up, 7/14 questions previously rated as mis-specified in the Intervention Group had all dimensions described at follow-up (p = 0.008) while the Control Group did not show any changes from baseline. Participants in the Intervention Group were also more likely to explicitly describe patients (p = 0.028), comparisons (p = 0.014), and outcomes (p = 0.008). CONCLUSIONS: This trial demonstrated the positive impact of specific instructions on the proportion of properly-specified clinical queries. The evaluation of the long-term impact of such changes is an area of continued research.


Assuntos
Medicina Baseada em Evidências/normas , Hospitais/normas , Hospitais/tendências , Pessoal Técnico de Saúde/normas , Medicina Baseada em Evidências/tendências , Seguimentos , Humanos , Enfermeiros Clínicos/normas , Médicos/normas , Tamanho da Amostra , Sensibilidade e Especificidade , Inquéritos e Questionários/normas , Tempo , Resultado do Tratamento
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