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1.
EClinicalMedicine ; 18: 100246, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31956857

RESUMO

BACKGROUND: Self-harm in adolescents is common and repetition frequent. Evidence for effective interventions to reduce self-harm is limited. Long term follow-up of existing studies is rare. METHODS: Extended follow up, from 18 to at least 36-months, of the SHIFT trial: a pragmatic, multi-centre, individually-randomised, controlled trial involving young people (11-17) who had self-harmed at least twice and presented to Child & Adolescent Mental Health Services (CAMHS). SHIFT evaluated manualised family therapy (FT) versus treatment as usual (TAU) in reducing repetition of self-harm leading to hospital attendance 18 months post-randomisation.We obtained ONS mortality data, adult mental health data, and further details of hospital attendance from routine Hospital Episode Statistics (HES) data plus researcher follow-up. We assessed longer-term differences in outcome using multivariable Cox Proportional Hazards regression analysis, and assessed all-cause mortality and morbidity relating to hospital attendances for reasons other than self-harm. STUDY REGISTRATION: ISRCTN 59793150. OUTCOMES: The original sample of 832 were randomised between April 2010 and December 2013. Extended follow-up continued until February 2017 for a median 55·4 months (range 0-82·5 months), providing post 18-month data for 804 (96·6%) participants, of whom 785 (94·4%) had a minimum of 36-months follow-up.There was no evidence of a between-group difference in the primary outcome during the extended follow-up period (Hazard Ratio (HR) 1·03; 95% CI: 0·83, 1·28; p-value=0·78), consistent with our findings in the original trial with 18 months follow-up (HR 1·14, 95% CI 0·87, 1·49; p-value 0·33). There was a reduced rate of self-harm in older participants aged 15-17 (HR 0·7, 95% CI 0·56, 0·88), as compared with those aged 11-14; and significantly increased rates of self-harm in participants whose index episode combined self-injury and poisoning (HR 1·8, 95% CI 1·2, 2·7). Two deaths were reported during the extended follow up period. INTERPRETATION: For adolescents referred to CAMHS after self-harm, having self-harmed at least once before, trial FT confers no benefits over TAU in reducing subsequent hospitalisation for self-harm over 18 months or 36 months. FUNDING: NIHR HTA Reference: 07/33/01.

2.
Eur J Clin Microbiol Infect Dis ; 36(12): 2405-2415, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28780742

RESUMO

Some strains of Clostridium difficile produce a binary toxin, in addition to the main C. difficile virulence factors (toxins A and B). There have been conflicting reports regarding the role of binary toxin and its relationship to the severity of C. difficile infection (CDI). Samples, isolates and clinical data were collected as part of a prospective multicentre diagnostic study. Clostridium difficile isolates (n = 1259) were tested by polymerase chain reaction (PCR) assay to detect binary toxin genes cdtA and cdtB. The PCR binary toxin gene results were compared with clinical severity and outcome data, including 30-day all-cause mortality. The 1259 isolates corresponded to 1083 different patients (October 2010 to September 2011). The prevalence of binary toxin positive strains was significantly higher in faecal samples with detectable toxin A/B than in those without toxin but that were positive by cytotoxigenic culture (26.3% vs. 10.3%, p < 0.001). The presence of binary toxin correlated moderately with markers of CDI severity (white cell count, serum albumin concentration and serum creatinine concentration). However, the risk ratio for all-cause mortality was 1.68 for binary toxin positive patients and patients were significantly less likely to survive if they had CDI caused by a binary toxin gene positive strain, even after adjusting for age (p < 0.001). The presence of binary toxin genes does not predict the clinical severity of CDI, but it is significantly associated with the risk of all-cause mortality.


Assuntos
Clostridioides difficile/genética , Infecções por Clostridium/microbiologia , Endotoxinas/genética , Idoso , Idoso de 80 Anos ou mais , Toxinas Bacterianas/genética , Biomarcadores , Causas de Morte , Clostridioides difficile/patogenicidade , Infecções por Clostridium/diagnóstico , Infecções por Clostridium/epidemiologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
3.
J Endocrinol ; 191(1): 9-14, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17065384

RESUMO

Circulating estradiol (E(2)), progesterone (Pro), testosterone, and corticosterone (B) levels were monitored in the green turtles Chelonia mydas during different nesting phases. Successful nesting includes emergence from sea, chamber and nest excavation, oviposition, burying the nest, and returning to sea. Unsuccessful nesting includes chamber and nest excavations but without oviposition. Blood samples were taken from the cervical sinus and collected within 5-min of capture to minimize stress. The samples were collected between 2000 and 0100 h during the peak season (May-October). High-performance liquid chromatography using a u.v. detection system coupled with tandem quadrupole mass spectrometry was used to measure B. Plasma B levels were significantly higher in successful and unsuccessful phases over emergence and excavation phases. However, B levels in successful versus unsuccessful or emergence versus excavation phases were not significantly different. Plasma steroid levels were measured by the Coat-A-Count RIA technique. Pro levels were significantly higher (P<0.005) in successful over unsuccessful turtles and also successful turtles over turtles in the other phases (P<0.01). The Pro levels immediately after nesting were found to be higher than that reported previously. Plasma testosterone values were higher in successful turtles but not significantly different from the turtles in other phases. Estrogen levels were undetected in all phases. Overall, the hormone values during different phases of nesting may play a major role in formulating the nesting behavior and physiology of the nesting activities in the green turtle.


Assuntos
Hormônios/sangue , Comportamento de Nidação/fisiologia , Oviposição/fisiologia , Tartarugas/sangue , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Corticosterona/sangue , Estradiol/sangue , Feminino , Progesterona/sangue , Reprodução/fisiologia , Espectrometria de Massas em Tandem , Testosterona/sangue
4.
J Pathol ; 204(4): 377-85, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15495267

RESUMO

Whilst the importance of mutations in a wide range of keratins in skin fragility disorders is now well established, there is much less evidence for simple epithelial keratin involvement in disease. Some simple epithelial keratin mutations have been reported in liver cirrhosis and pancreatitis patients, and recently mutations in the simple epithelial keratin K8 were identified in a group of patients with inflammatory bowel disease (Crohn disease or ulcerative colitis). In comparison with the mutations seen in epidermal keratins, these simple epithelial mutations would be predicted to have mild consequences, although analysis shows that they do have a distinct effect. This review article discusses the evidence that these mutations are a predisposing factor for inflammatory bowel disease.


Assuntos
Doenças Inflamatórias Intestinais/genética , Queratinas/genética , Colo/patologia , Citoesqueleto/patologia , Células Epiteliais/fisiologia , Predisposição Genética para Doença/genética , Humanos , Doenças Inflamatórias Intestinais/patologia , Queratina-18 , Queratina-8 , Mutação , Estresse Mecânico
5.
J Cell Sci ; 117(Pt 10): 1989-99, 2004 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15090596

RESUMO

We have identified miss-sense mutations in keratin 8 in a subset of patients with inflammatory bowel disease (Crohn disease and ulcerative colitis). Inflammatory bowel diseases are a group of disorders that are polygenic in origin and involve intestinal epithelial breakdown. We investigated the possibility that these keratin mutations might contribute to the course of the disease by adversely affecting the keratin filament network that provides mechanical support to cells in epithelia. The mutations (Gly62 to Cys, Ile63 to Val and Lys464 to Asn) all lie outside the major mutation hotspots associated with severe disease in epidermal keratins, but using a combination of in vitro and cell culture assays we show that they all have detrimental effects on K8/K18 filament assembly in vitro and in cultured cells. The G62C mutation also gives rise to homodimer formation on oxidative stress to cultured intestinal epithelial cells, and homodimers are known to be polymerization incompetent. Impaired keratin assembly resulting from the K8 mutations found in some inflammatory bowel disease patients would be predicted to affect the maintenance and re-establishment of mechanical resilience in vivo, as required during keratin cytoskeleton remodeling in cell division and differentiation, which may lead to epithelial fragility in the gut. Simple epithelial keratins may thus be considered as candidates for genes contributing to a risk of inflammatory bowel disease.


Assuntos
Doenças Inflamatórias Intestinais/genética , Queratinas/genética , Mutação , Citoesqueleto de Actina/ultraestrutura , Animais , Anticorpos Monoclonais/química , Sequência de Bases , Diferenciação Celular , Cromossomos Humanos Par 12/ultraestrutura , Colite Ulcerativa/patologia , Doença de Crohn/genética , Dimerização , Eletroforese em Gel de Poliacrilamida , Humanos , Inflamação , Doenças Inflamatórias Intestinais/metabolismo , Queratina-8 , Queratinas/química , Queratinas/metabolismo , Camundongos , Modelos Genéticos , Dados de Sequência Molecular , Estresse Oxidativo , Polímeros/química , Ligação Proteica , Conformação Proteica , Análise de Sequência de DNA , Fatores de Tempo , Transfecção , Xenopus
6.
Br J Cancer ; 87(10): 1128-35, 2002 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-12402152

RESUMO

Elevated expression and/or activity of c-Src, the prototype of the Src family of protein tyrosine kinases, is associated with the development of human colon cancer. However, despite the known pleiotropic effects of these kinases in promoting (a) cell growth downstream of growth factor receptors, and (b) the dynamic regulation of integrin adhesions in fibroblast model systems, their precise role in epithelial cancer cells is unknown. Here we addressed whether elevated expression and activity of cellular Src alters cell proliferation and/or cell-matrix adhesion in cancer cells from the Fidler model of colorectal metastasis. Although elevated Src correlates with ability to metastasise to the liver after intrasplenic injection, we found that this was not linked to enhanced growth, either in vitro or in vivo as sub-cutaneous tumours. However, elevated Src was associated with enhanced attachment to extracellular matrix. In addition, adhesion to fibronectin, was suppressed by agents that inhibited Src activity, while enforced elevation of Src in non-metastatic cells was sufficient to stimulate adhesion to fibronectin and enhanced assembly of adhesion complexes, without influencing cell growth. Thus, we conclude that one role of elevated Src in human colon cancer cells is to modulate integrin-dependent cell-matrix attachment and formation of adhesion structures, which may, in turn, influence cell motility and integrin-dependent cellular responses.


Assuntos
Junções Célula-Matriz/fisiologia , Neoplasias Colorretais/patologia , Proteína Oncogênica pp60(v-src)/metabolismo , Proteínas Tirosina Quinases/fisiologia , Adesão Celular , Neoplasias Colorretais/metabolismo , Humanos , Metástase Neoplásica , Proteína Oncogênica pp60(v-src)/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Células Tumorais Cultivadas
7.
Biochem Biophys Res Commun ; 269(2): 369-76, 2000 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-10708559

RESUMO

The origin of the signal for keratinocyte differentiation is still unknown. Here, we show that Ca(2+)- and density-induced translocation of E-cadherin, but not P-cadherin, is accompanied by induction of differentiation-specific proteins in cultured keratinocytes. Antibodies that artificially cluster cell-surface E-cadherin in low extracellular Ca(2+) also induce differentiation-specific proteins, implicating E-cadherin as a determinant of keratinocyte differentiation in vitro.


Assuntos
Caderinas/metabolismo , Diferenciação Celular , Queratinócitos/citologia , Cálcio/metabolismo , Adesão Celular , Comunicação Celular , Células Cultivadas , Humanos , Queratinócitos/enzimologia , Queratinócitos/metabolismo , Precursores de Proteínas/metabolismo , Transglutaminases/metabolismo
8.
Mol Biol Cell ; 11(1): 51-64, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10637290

RESUMO

Despite the importance of epithelial cell contacts in determining cell behavior, we still lack a detailed understanding of the assembly and disassembly of intercellular contacts. Here we examined the role of the catalytic activity of the Src family kinases at epithelial cell contacts in vitro. Like E- and P-cadherin, Ca(2+) treatment of normal and tumor-derived human keratinocytes resulted in c-Yes (and c-Src and Fyn), as well as their putative substrate p120(CTN), being recruited to cell-cell contacts. A tyrosine kinase inhibitor with selectivity against the Src family kinases, PD162531, and a dominant-inhibitory c-Src protein that interferes with the catalytic function of the endogenous Src kinases induced cell-cell contact and E-cadherin redistribution, even in low Ca(2+), which does not normally support stable cell-cell adhesion. Time-lapse microscopy demonstrated that Src kinase inhibition induced stabilization of transiently formed intercellular contacts in low Ca(2+). Furthermore, a combination of E- and P-cadherin-specific antibodies suppressed cell-cell contact, indicating cadherin involvement. As a consequence of contact stabilization, normal cells were unable to dissociate from an epithelial sheet formed at high density and repair a wound in vitro, although individual cells were still motile. Thus, cadherin-dependent contacts can be stabilized both by high Ca(2+) and by inhibiting Src activity in low (0.03 mM) Ca(2+) in vitro.


Assuntos
Caderinas/metabolismo , Comunicação Celular , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Actinas/metabolismo , Transporte Biológico , Cálcio/metabolismo , Catálise , Células Cultivadas , Citoesqueleto/metabolismo , Inibidores Enzimáticos/farmacologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Proteínas Proto-Oncogênicas c-fyn , Proteínas Proto-Oncogênicas c-yes , Células Tumorais Cultivadas , Quinases da Família src/metabolismo
9.
Oncogene ; 18(41): 5646-53, 1999 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-10523844

RESUMO

Focal adhesion kinase (pp125FAK) is present at sites of cell/extracellular matrix adhesion and has been implicated in the control of cell behaviour. In particular, as a key component of integrin-stimulated signal transduction pathways, pp125FAK is involved in cellular processes such as spreading, motility, growth and survival. In addition, a number of reports have indicated that pp125FAK may be up-regulated in human tumour cells of diverse origin, and consequently, a role has been proposed for pp125FAK in the development of invasive cancers. However, to date the mechanisms that lead to elevated pp125FAK expression in tumour cells have not been determined. Here we used in situ hybridization to confirm chromosome 8q as the genomic location of the human fak gene and report that elevation of pp125FAK protein in cell lines derived from invasive squamous cell carcinomas is accompanied by gains in copy number of the fak gene in all cases examined. In addition, we observed increased fak copy number in frozen sections of squamous cell carcinomas. Furthermore, increased dosage of the fak gene was also observed in many cell lines derived from human tumours of lung, breast and colon, including two cell lines Calu3 and HT29, in which fak was amplified. In addition, in an in vitro model for human colon cancer progression there was a copy number gain of the fak gene during conversion from adenoma to carcinoma, which was associated with increased pp125FAK protein expression. Thus, we show for the first time that many cell lines derived from invasive epithelial tumours have increased dosage of the fak gene, which may contribute to the elevated protein expression commonly observed. Although other genes near the fak locus are co-amplified or increased in copy number, including the proto-oncogene c-myc, the biological properties of pp125FAK in controlling the growth, survival and invasiveness of tumour cells, suggest that it may contribute to the selection pressure for maintaining increased dosage of the region of chromosome 8q that encodes these genes.


Assuntos
Carcinoma de Células Escamosas/genética , Moléculas de Adesão Celular/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/genética , Proteínas de Neoplasias/genética , Proteínas Tirosina Quinases/genética , Adenoma/enzimologia , Adenoma/genética , Adenoma/patologia , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma/enzimologia , Carcinoma/genética , Carcinoma/patologia , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/patologia , Moléculas de Adesão Celular/biossíntese , Cromossomos Humanos Par 8/genética , Neoplasias do Colo/enzimologia , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Indução Enzimática , Feminino , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Amplificação de Genes , Dosagem de Genes , Genes myc , Neoplasias de Cabeça e Pescoço/enzimologia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Hibridização in Situ Fluorescente , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Invasividade Neoplásica/genética , Proteínas de Neoplasias/biossíntese , Proteínas Tirosina Quinases/biossíntese , Proto-Oncogene Mas , Seleção Genética , Transdução de Sinais/genética , Células Tumorais Cultivadas/enzimologia
10.
J Exp Zool ; 284(6): 652-62, 1999 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-10531552

RESUMO

Adrenocortical responsiveness to turning stress was examined in wild, reproductively-active olive ridley sea turtles (Lepidochelys olivacea) in relation to their mass nesting (arribada) behavior. We hypothesized that the high sensitivity threshold (HST) observed in ovipositing sea turtles is associated with a diminished sensitivity of the hypothalamo-pituitary-adrenal (HPA) axis to stressful stimuli in arribada females. We tested this hypothesis by determining whether arribada females exhibited an increased activation threshold of the HPA axis to an imposed stressor (turning stress). Mean basal corticosterone (B) and glucose levels were below 1.0 ng/ml and 60 mg/dl, respectively. Basal B remained unchanged throughout a 24-hr period in basking females. Most animals responded to turning stress with elevated mean B levels (up to 6.5 ng/ml after 6 hr) and no increase in circulating glucose. Nearly 50% of females (and none of the males) were refractory to the stimulation. Males exhibited the most rapid response, with B levels significantly elevated by 20 min over basal levels. Among females, arribada and solitary nesters exhibited a slower rate of response than basking, non-nesting animals. These results demonstrate that olive ridleys exhibit stress-induced changes in circulating B which are slower than those observed in most reptilian and in mammalian, avian, and piscine species. Furthermore, the presence of refractory females and the relatively slower increase in B in arribada and solitary nesters indicate a hyporesponsiveness of the HPA axis to turning stress in nesting olive ridleys. The hyporesponsiveness may be part of a mechanism to facilitate arribada nesting. J. Exp. Zool. 284:652-662, 1999.


Assuntos
Corticosterona/sangue , Comportamento de Nidação/fisiologia , Estresse Psicológico/sangue , Tartarugas/fisiologia , Animais , Glicemia , Feminino , Masculino , Oviposição/fisiologia , Radioimunoensaio , Testosterona/sangue , Tartarugas/sangue
11.
Gen Comp Endocrinol ; 109(2): 232-43, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9473367

RESUMO

The seasonal reproductive cycle of the Kemp's ridley sea turtle (Lepidochelys kempi) was studied under seminatural conditions at the Cayman Turtle Farm, Grand Cayman, British West Indies, from June 1987 to July 1988. Male L. kempi displayed a prenuptial rise in serum testosterone 4 to 5 months prior to the mating period (March). Male testosterone then declined sharply during the mating period. Female L. kempi also displayed a prenuptial rise in serum testosterone, estradiol, and total calcium 4 to 6 months prior to the mating period (March). Female testosterone and estradiol declined during the nesting period (April to July) immediately following the mating period (March). Elevated levels in female estradiol and total calcium corresponded with the period of vitellogenesis as determined from gel electrophoresis and ultrasonography. Serum thyroxine also fluctuated seasonally with elevated levels observed in females associated with the period of vitellogenesis. L. kempi displayed a distinct seasonal reproductive cycle in captivity. Nesting in the captive study group corresponded with nesting in the wild population at Rancho Nuevo, Mexico (April to July). Female endocrine cycles during the nesting period were similar to those observed in the wild population.


Assuntos
Reprodução/fisiologia , Estações do Ano , Tartarugas/fisiologia , Animais , Comportamento Animal/fisiologia , Cálcio/sangue , Estradiol/sangue , Feminino , Masculino , Comportamento de Nidação/fisiologia , Progesterona/sangue , Testosterona/sangue , Tiroxina/sangue
12.
J Exp Zool ; 278(6): 372-80, 1997 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-9262006

RESUMO

Captive immature green (Chelonia mydas) and Kemp's ridley (Lepidochelys kempi) sea turtles were examined to determine if a hibernation-like state could be induced under controlled conditions. Both species demonstrated that they are able to acclimate to cold temperatures behaviorally. However, the two species appeared to respond differently to decreasing temperature. Whereas the green turtles tolerated the onset of cold water temperatures by reducing swimming activity, the ridleys became very agitated and active as they were exposed to temperatures below 20 degrees C. Nevertheless, both species displayed semi-dormant behavior at temperatures below 15 degrees C, coming to the surface to breathe periodically at intervals of up to three hours. At low temperatures, venous blood pO2 and pCO2 decreased, whereas venous blood pH increased. Feeding also decreased as either species was exposed to cold temperature: greens (at 15 degrees C) and ridleys (at 20 degrees C) decreased food consumption to 50% of control levels, and ceased feeding below 15 degrees C. Thus, these species tolerated temperature drops and the associated hypophagia. They did not exhibit cold-stunning behavior, as has been observed in wild sea turtles exposed to rapid temperature drops, or prolonged periods of hibernation-like dormancy, as has been proposed for wild sea turtles during cold winter months.


Assuntos
Dióxido de Carbono/sangue , Comportamento Alimentar/fisiologia , Hibernação/fisiologia , Oxigênio/sangue , Respiração/fisiologia , Tartarugas/fisiologia , Animais , Comportamento Animal , Gasometria , Peso Corporal , Temperatura Baixa , Concentração de Íons de Hidrogênio , Aumento de Peso
14.
Science ; 266(5188): 1218-22, 1994 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-17810264

RESUMO

Carbon nanotubes produced in arcs have been found to have the form of multiwalled fullerenes, at least over short lengths. Sintering of the tubes to each other is the predominant source of defects that limit the utility of these otherwise perfect fullerene structures. The use of a water-cooled copper cathode minimized such defects, permitting nanotubes longer than 40 micrometers to be attached to macroscopic electrodes and extracted from the bulk deposit. A detailed mechanism that features the high electric field at (and field-emission from) open nanotube tips exposed to the arc plasma, and consequent positive feedback effects from the neutral gas and plasma, is proposed for tube growth in such arcs.

15.
Gen Comp Endocrinol ; 87(1): 71-8, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1624099

RESUMO

Changes in serum concentrations of gonadotropins and gonadal steroids during the periovulatory period were monitored in green, Chelonia mydas, and loggerhead, Caretta caretta, sea turtles. Turtles were from natural populations that nest on a coral island on the Great Barrier Reef. After nesting, each turtle was transferred to a holding tank and held for a maximum of 8 days. A time series of blood samples was obtained from each of five sea turtles (three C. mydas and two C. caretta) starting immediately after nesting and then at approximately 12-hr intervals until the time of release. Prior to release back into the ocean, each turtle was examined by laparoscopy to verify that ovulation had occurred. Serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone (PRO), and testosterone (T) in both species exhibited significant changes during this period. Surges of FSH, LH, and PRO were evident within approximately 20 to 50 hr after each turtle had nested. The significant change in FSH concentration during the periovulatory period is the first such report for a reptile. Coincident with maximal concentrations of FSH, LH, and PRO was a decline in T concentrations in both species. Estradiol-17 beta concentrations were near or below assay sensitivity in the C. mydas, whereas those in the C. caretta were detectable but exhibited no significant changes. The dynamic changes in FSH, LH, PRO, and T concentrations are consistent with the hypothesis that these hormones facilitate specific physiological events during ovulation and egg production.


Assuntos
Gonadotropinas/sangue , Ovário/fisiologia , Ovulação/fisiologia , Esteroides/sangue , Tartarugas/fisiologia , Animais , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Progesterona/sangue , Radioimunoensaio , Testosterona/sangue , Tartarugas/sangue
16.
Gen Comp Endocrinol ; 79(1): 154-64, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2354777

RESUMO

Adult male loggerhead sea turtles, Caretta caretta, exhibited a "prenuptial" spermatogenic cycle that was coincident with increased concentrations of serum testosterone (T). Serum T was high during the months when migration and mating have been recorded for males. In contrast to females, males appear to be annual breeders. Nine reproductively active female C. caretta (as verified through laparoscopy) were tagged with sonic transmitters and were repeatedly bled prior to migration. Four months prior to the nesting season, the ovaries of reproductively active females had hundreds of vitellogenic follicles of approximately 1.5 cm in diameter (i.e., half the size of ovulatory follicles). Approximately 4-6 weeks prior to migration from feeding grounds to mating and nesting areas, serum estradiol-17 beta (E2) concentrations increased significantly and remained high for approximately 4 weeks, suggesting a period of increased vitellogenesis. During a 1- to 2-week period prior to migration, serum E2 decreased significantly, while serum T concentrations increased (at least) until the time of migration. Serum T, E2, and progesterone (PRO) were elevated during nesting if a turtle was going to nest again during that nesting season. During the last nesting of a season, turtles had low serum concentrations of T, E2, and Pro. The prenuptial pattern of gonadal recrudescence and gonadal steroid production in both male and female C. caretta contrasts with those of many temperate freshwater turtles, and this type of reproductive pattern may have been facilitated by adaptation to a tropical marine environment.


Assuntos
Hormônios Esteroides Gonadais/sangue , Estações do Ano , Tartarugas/fisiologia , Animais , Estradiol/sangue , Feminino , Masculino , Ovário/fisiologia , Oviposição , Progesterona/sangue , Reprodução , Espermatogênese , Testosterona/sangue , Vitelogênese
18.
Gen Comp Endocrinol ; 73(2): 223-32, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2707582

RESUMO

Arginine vasotocin (AVT) and neurophysin (NP) levels were measured by radioimmunoassay in two species of sea turtle, the olive ridley, Lepidochelys olivacea, and the loggerhead, Caretta caretta, during the brief period of nesting and oviposition. In both species, AVT was low in animals which were not reproductively active. AVT was also low at the time animals emerged from the surf to nest, but increased significantly during oviposition and then declined as the animals returned to the water. NP increased in concert with AVT, also reaching highest levels during oviposition. In both species, however, NP levels remained elevated over prenesting levels at the time of return to the water. These findings are consistent with the hypothesis that an AVT-neurophysin complex is released from the neurohypophysis during nesting, and that AVT is a physiological regulator of oviducal contractions in sea turtles.


Assuntos
Comportamento de Nidação/fisiologia , Neurofisinas/sangue , Tartarugas/fisiologia , Vasotocina/sangue , Animais , Química Encefálica , Feminino , Músculos/análise , Radioimunoensaio , Pele/análise , Vasotocina/análise
19.
Br J Psychiatry ; 152: 830-3, 1988 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3167470

RESUMO

Consecutive attenders (525) presenting at the Nottingham Accident and Emergency (A & E) department with deliberate self-poisoning were identified retrospectively. Their case-notes were examined for patient characteristics and clinical management. The Nottingham Psychiatric Case Register was examined for previous contact and use of psychiatric services over a 2-year follow-up period. Significant differences were found between those patients admitted to a ward and those who returned home from the A & E Department, in respect of likelihood of psychiatric morbidity and use of psychiatric services. One in three self-poisoning patients returns home directly from the accident department, and there seemed to be appropriate selection.


Assuntos
Intoxicação/terapia , Tentativa de Suicídio , Adolescente , Adulto , Fatores Etários , Idoso , Serviços Médicos de Emergência/estatística & dados numéricos , Inglaterra , Feminino , Hospitalização , Humanos , Masculino , Serviços de Saúde Mental/estatística & dados numéricos , Pessoa de Meia-Idade , Recidiva , Fatores Sexuais , Fatores de Tempo
20.
Science ; 224(4644): 83-4, 1984 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-17783530

RESUMO

Sea turtles (Lepidochelys kempi) are being artificially imprinted to Padre Island, Texas, in an effort to establish a new nesting population. These turtles spent more time per exposure in solutions made of Padre Island sand and seawater than in control solutions in a multiple-choice test. This is evidence that sea turtles may detect differences in natural water samples and remember olfactory cues to which they were exposed neonatally and that these differences may affect their orientation behavior. This suggests that imprinting could be used as a conservation technique for establishing new breeding populations of endangered sea turtles.

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