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1.
Animal ; 18(8): 101239, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39053154

RESUMO

The demand for sustainable and ethically farmed animal products is on the rise as consumers become more environmentally and animal welfare conscious. The need to diminish the consumption of soybean meal is urgent, and companies are looking for ways to respond to this necessity by looking for alternatives to soybean meal. This study assessed the impact of introducing whole dehydrated and live black soldier fly larvae (BSFL) into the diet of an indigenous chicken breed as environmental enrichment. A total of 144 39-day-old male Bianca di Saluzzo chickens were distributed among 18 pens and assigned to three different experimental groups. The control group received a diet where soybean meal was entirely replaced by alternative ingredients. The two experimental groups were given the same diet supplemented with 5% of the expected daily feed intake of whole dehydrated BSFL or whole live BSFL. Throughout the trial period (from the bird age of 39-174 days of age), live weight was recorded every 21 days, and the average daily gain, daily feed intake, and feed conversion ratio were calculated. The time required for the birds to consume the larvae was recorded three times a week. At age 147 and 174 days, 12 birds per treatment were selected based on mean live weight and slaughtered. Measurements included hot and chilled carcass weights, organ weights (spleen, liver, heart, stomach), breast and thigh muscle weights, and the corresponding yields were calculated. Acid protease activity was measured in proventriculus extract, and chitinase and chitosanase activity was calculated based on the release of reducing sugars from chitin or chitosan. The results showed little improvement in final live weights and daily feed intakes of the animals fed the insect larvae compared with control birds. Larva supplementation had no negative impact on the overall well-being of the animals assessed by blood analysis and histopathological assessment of the intestinal tract, spleen, and liver. No differences were found between the dehydrated vs live insect larvae consumption times, with all larvae being eaten up very rapidly (< 3 min). The birds fed BSFL showed an increase in chitinase activity. These findings support the potential use of whole BSFL as a form of environmental enrichment, particularly in their dehydrated form, being more convenient to use and store, which would also encourage the uptake of this practice by farmers.


Assuntos
Ração Animal , Galinhas , Dieta , Larva , Animais , Galinhas/crescimento & desenvolvimento , Galinhas/fisiologia , Larva/crescimento & desenvolvimento , Masculino , Ração Animal/análise , Dieta/veterinária , Simuliidae/fisiologia , Dípteros/fisiologia , Dípteros/crescimento & desenvolvimento , Trato Gastrointestinal/fisiologia , Quitinases/metabolismo
2.
Pediatr Hematol Oncol ; 39(1): 74-79, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34018455

RESUMO

Rubinstein-Taybi syndrome (RSTS) is an autosomal dominant disorder, caused by variants in CREBBP or EP300. Affected individuals present with distinctive craniofacial features, broad thumbs and/or halluces, intellectual disability and immunodeficiency. Here we report on one RSTS patient who experienced hemophagocytic lymphohystiocytosis (HLH) and disseminated herpes virus 1 ( HSV-1) disease. The clinical picture of RSTS is expanding to include autoinflammatory, autoimmune, and infectious complications. Prompt treatment of HLH and disseminated HSV-1 can lower the mortality rate of these life-threatening conditions.


Assuntos
Linfo-Histiocitose Hemofagocítica/etiologia , Síndrome de Rubinstein-Taybi , Infecções por Herpesviridae , Humanos , Síndrome de Rubinstein-Taybi/complicações
3.
Radiography (Lond) ; 27(2): 554-560, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33281035

RESUMO

INTRODUCTION: The present study aims to compare low-kV CT reconstructed with MBIR technique with MRI in detecting high-risk stigmata and worrisome features in patients with pancreatic cystic lesions. METHODS: We retrospective enrolled 75 patients who underwent low-kV CT with contrast media injection for general abdominal disorders and MRI with MRCP sequences. The reviewer, blinded to clinical and histopathological data, recorded the overall number of pancreatic cystic lesions, size, location, presence of calcifications, septa, or solid enhancing or non-enhancing components, main pancreatic duct (MPD) communication, and MPD dilatation. Mean differences with 95% limits of agreement, ICC, and κ statistics were used to compare CT and MRI. RESULTS: More pancreatic cystic lesions were detected with MRI than with CT, however, the ICC value of 0.81 suggested a good agreement. According to the evaluated target lesion, a very good agreement (ICC = 0.98) was found regarding the diameter (21.4 mm CT vs 21.8 mm MRI), the location (κ = 0.90), the detection of MPD dilatation (κ = 1), the presence of septa (κ = 0.86) and the MPD communication (κ = 0.87). A moderate agreement on the assessment of enhanced components was noted (κ = 0.44), while there was only a fair agreement about the presence of calcifications (κ = 0.87). CONCLUSION: MDCT can be considered almost equivalent to MRI with MRCP in the evaluation of worrisome features and high-risk stigmata, offering detailed morphologic features helpful for their characterization. IMPLICATIONS FOR PRACTICE: Even if MRI is considered the reference standard in pancreatic cystic lesions characterization, CT can be considered a useful tool as a first-line imaging technique to identify worrisome features and high-risk stigmata.


Assuntos
Cisto Pancreático , Neoplasias Pancreáticas , Algoritmos , Humanos , Imageamento por Ressonância Magnética , Cisto Pancreático/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
4.
J Biol Regul Homeost Agents ; 34(3 Suppl. 1): 9-17. DENTAL SUPPLEMENT, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32618156

RESUMO

After the static computer-guided implant surgery, borns the concept of "navigated implantology" (NI) that offers significant advantages in the treatment planning and help clinicians to perform successful implant rehabilitation. NI allows an optimal final location, to avoid the risk of damaging the noble anatomical structures near the site and allows the achievement of satisfactory aesthetics. The aim of this study is analyze three different systems: the RoboDent® system (Berlin, Germany, 2001), today not for sale, was the first implant navigation system introduced on the market and made the history of dynamic surgery; X-Guide (Nobel Biocare, 2017), a dynamic computer assisted system that uses the principles of stereoscopic triangulation by optical video cameras. And last, the Navident® dynamic navigation system (Toronto, Canada, 2015), produced by the Canadian company ClaroNav, evolved from the Navient brand used in orthopaedic surgery, neurosurgery and otolaryngology, sharing the motion tracking technology. Dynamic computer assisted surgery systems allow more accurate implant placement when based on an accurate 3D CT-based image data and an implant planning software which minimizes errors and simplify the surgical technique.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Canadá , Imageamento Tridimensional , Planejamento de Assistência ao Paciente , Software
5.
J Neurol ; 266(3): 707-716, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30649617

RESUMO

BACKGROUND: Little is known about the influence of multiple sclerosis (MS) diagnosis on parenthood attitude in people with MS (pwMS). OBJECTIVE: To investigate the impact of diagnosis, clinical features and external disease-related influences on parenthood decision-making in Italian pwMS. METHODS: A web-based survey was posted on SMsocialnetwork.com to investigate clinical status, parenthood desire, influences on family planning, pregnancy outcomes, abortions and adoptions of pwMS. RESULTS: 33/395 respondents never wanted to become parent because of MS ("anti-parenthood after diagnosis"). 362 declared to be in favor of parenthood. 51% pwMS having a child by the survey time had already received the MS diagnosis at first childbirth. The frequency of a second child in pwMS after diagnosis was 38% compared to 67% in people without yet MS diagnosis. 16% of pwMS were discouraged to become parent after diagnosis, mainly by medical personnel. In 71% of respondents, diagnosis did not delay the decision to become parent and only 39% were counseled by treating physician to plan pregnancy. Patients' distribution according to the clinical phenotype (exclusively relapsing vs exclusively progressive) showed a higher proportion of progressive patients in the "anti-parenthood after diagnosis" subgroup. CONCLUSION: MS diagnosis impacted dramatically on the life project of 7% of pwMS that decided not to have children because of the disease and in pro-parenthood pwMS impacted especially on having the second child. Only a minority was counseled to plan pregnancy. A worse disease course driving to a progressive phenotype at survey time might have negatively impacted on parenthood desire.


Assuntos
Tomada de Decisões/fisiologia , Esclerose Múltipla/psicologia , Sistemas On-Line , Pais/psicologia , Adulto , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico , Estatísticas não Paramétricas
6.
Mult Scler Relat Disord ; 25: 175-178, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30096683

RESUMO

BACKGROUND: Over the last few decades, patients have increasingly been searching for health information on the Internet. This aspect of information seeking is important, especially for people affected by chronic pathologies and require lifelong treatment and management. These people are usually very well informed about the disease but are nonetheless vulnerable to hopes of being cured or saved, often amplified by misinformation, myths, legends, and therapies that are not always scientifically proven. Many studies suggest that some individuals prefer to rely on the Internet as their main source of information, often hindering the patient-doctor relationship. A professional approach is imperative to maintain confidentiality, honesty, and trust in the medical profession. OBJECTIVE: we aimed to examine, in a medically supervised Italian web community (SMsocialnetwotk.com) dedicated to people with Multiple Sclerosis (pwMS), the posts shared by users and to verify the reliability of contents of posts shared by users pinpointed as Influencers through an online questionnaire. METHODS: we grouped the posts published on SMsocialnetwork from April to June 2015 into those with medical content (scientifically correct or fake news), and those related to social interactions. Later, we gave a questionnaire to the community asking to identify the three users/Influencers providing the most reliable advice for everyday life with MS and the three users/Influencers providing the most useful information about MS treatments. RESULTS: 308 posts reported scientific and relevant medical information, whereas 72 posts included pieces of fake news. 1420 posts were of general interest. Four out of the 6 Influencers had written only posts with correct medical information (3 were pwMS, 1 was a Neurologist) and never any fake news. The remaining 2 appointed Influencers (2 pwMS) had written only posts about general interests. CONCLUSION: the identification of fake news and their authors has shown that the latter are never appointed as Influencers. SMsocialnetwork.com acted as a "web safe environment" where the Influencers contributed by sharing only correct medical information and never fake news. We speculate that the presence of neurologists and psychologists supervising the information flow might have contributed to reduce the risk of fake news spreading and to avoid their acquisition of authoritative meaning.


Assuntos
Pessoal de Saúde/psicologia , Internet , Esclerose Múltipla/psicologia , Relações Médico-Paciente , Rede Social , Feminino , Humanos , Relações Interpessoais , Itália , Masculino , Esclerose Múltipla/terapia , Projetos Piloto
7.
Vet J ; 222: 17-21, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28410671

RESUMO

We sought to determine the prevalence of dog erythrocyte antigen (DEA) 1, 4 and 7 and naturally occurring anti-DEA7 antibodies in Italian Corso dogs. In addition, we correlated DEAs with different epidemiologic variables, compared the prevalence of DEAs against other canine populations and assessed the risk of sensitisation and transfusion reactions (TRs) following unmatched transfusion. Blood samples from 100 Corso dogs were evaluated for DEA 1, 4, 7 and naturally occurring anti-DEA 7 antibodies. Seventy-one percent of samples were DEA 1-negative, 100% tested DEA 4-positive, and 95% tested DEA 7-negative. Suspected anti-DEA7 antibodies were found in 32% dogs. The DEA 1 and 7-negative phenotypes were significantly more common than in most canine populations. When a previously tested Italian canine population was considered as blood donors for Corso dogs, the risk of DEA 1 sensitisation using DEA 1 untyped blood was 29%, and of acute haemolytic TRs after a second untyped DEA 1-incompatible transfusion was 8%. The potential for delayed TRs between DEA 7-negative Corso dogs with suspected naturally occurring anti-DEA 7 antibodies receiving untyped DEA 7-positive blood was 11%. Conversely, when Corso dogs were blood donors for the same population, the risk of DEA 1 sensitisation was 17% and the risk of an acute haemolytic TR after a second DEA 1-incompatible blood transfusion was 3%. Corso dogs can be suitable blood donors. Additional studies are needed to clarify whether the high prevalence of naturally occurring anti-DEA 7 antibodies in this breed could increase their risk of delayed TRs when they are blood recipients.


Assuntos
Autoanticorpos/imunologia , Antígenos de Grupos Sanguíneos/imunologia , Cães/imunologia , Eritrócitos/imunologia , Animais , Tipagem e Reações Cruzadas Sanguíneas/veterinária , Transfusão de Sangue/veterinária , Doenças do Cão/sangue , Cães/sangue , Feminino , Masculino , Especificidade da Espécie , Reação Transfusional/veterinária
8.
Skeletal Radiol ; 45(4): 495-503, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26782927

RESUMO

PURPOSE: To assess the diagnostic value of MRI examination in detecting and monitoring osteonecrotic lesions (ON) in childhood acute lymphoblastic leukaemia (ALL) after chemotherapy (CHT) and/or bone marrow transplantation (BMT). METHODS AND MATERIALS: Seventy-three patients (37 males, mean age 12.4 years old) with ALL after treatment underwent a lower-limb MR examination between November 2006 and March 2012. In 47 there was clinical suspicion of ON, 26 were asymptomatic. Studies were performed with a 1 T and a 1.5 T scanner, acquiring short tau inversion recovery (STIR) and T1-weighted sequences in coronal plane from the hips to the ankles. The average acquisition time was 18 min. Considering baseline and follow-up examinations, the overall number of MRI studies was 195. RESULTS: Fifty-four of 73 patients showed ON at MRI study, with an overall number of 323 ON (89 involving articular surface, 24 with joint deformity, JD). Twenty-five of 47 symptomatic patients showed subchondral ON lesions, 11 developed JD. Three of 26 asymptomatic patients showed subchondral bone ON at baseline examination but no JD at follow-up. Twenty-two of 28 BMT, 32/45 CHT patients developed ON. CONCLUSION: Our MRI protocol proved to be feasible in evaluating ON in paediatric patients. Studies should be addressed only to symptomatic patients.


Assuntos
Extremidade Inferior/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Osteonecrose/diagnóstico por imagem , Osteonecrose/etiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Transplante de Medula Óssea , Criança , Feminino , Humanos , Extremidade Inferior/patologia , Masculino , Osteonecrose/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia
9.
Gastroenterol Res Pract ; 2015: 707546, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26136775

RESUMO

Purpose. To assess the diagnostic value of 256-detector row MDCT in the characterization of incidentally detected pancreatic cystic lesions (PCLs). Materials and Methods. We retrospectively reviewed 6389 studies performed on a 256-row detector scanner, wherein ≥1 PCLs were incidentally detected. Images from a total of 192 patients (99 females; age range 31-90 years) were analysed referring to morphologic predictive signs of malignancy, including multifocality, inner septa, wall thickening, and mural enhancing nodules. Results. We evaluated 292 PCLs in 192 patients (solitary in 145 and ≥2 in 47; incidence 2.05%). Size ranged from 3 to 145 mm (mean 15 mm); body was the most common location (87/292; 29.8%). Intralesional septa were detected in 52/292 lesions (17.8%), wall thickening >2 mm in 13 (4.5%), enhancing wall and mural nodules in 15 (5.1%) and 12 (4.1%), respectively. Communication with ductal system was evident in 45 cases. The most common diagnoses, established by histology or imaging analysis, were IPMNs (about 86%), while serous cystic neoplasia (3.7%) and metastases (0.5%) were the less common. Conclusion. MDCT provides detailed features for characterization of PCLs, which are incidentally discovered with increased frequency due to the widespread use of cross-sectional imaging.

10.
Br J Radiol ; 88(1049): 20140140, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25784185

RESUMO

OBJECTIVE: To assess the diagnostic quality of low dose (100 kV) CT angiography (CTA), by using ultra-low contrast medium volume (30 ml), for thoracic and abdominal aorta evaluation. METHODS: 67 patients with thoracic or abdominal vascular disease underwent multidetector CT study using a 256 slice scanner, with low dose radiation protocol (automated tube current modulation, 100 kV) and low contrast medium volume (30 ml; 4 ml s(-1)). Density measurements were performed on ascending, arch, descending thoracic aorta, anonymous branch, abdominal aorta, and renal and common iliac arteries. Radiation dose exposure [dose-length product (DLP)] was calculated. A control group of 35 patients with thoracic or abdominal vascular disease were evaluated with standard CTA protocol (automated tube current modulation, 120 kV; contrast medium, 80 ml). RESULTS: In all patients, we correctly visualized and evaluated main branches of the thoracic and abdominal aorta. No difference in density measurements was achieved between low tube voltage protocol (mean attenuation value of thoracic aorta, 304 HU; abdominal, 343 HU; renal arteries, 331 HU) and control group (mean attenuation value of thoracic aorta, 320 HU; abdominal, 339; renal arteries, 303 HU). Radiation dose exposure in low tube voltage protocol was significantly different between thoracic and abdominal low tube voltage studies (490 and 324 DLP, respectively) and the control group (thoracic DLP, 1032; abdomen, DLP 1078). CONCLUSION: Low-tube-voltage protocol may provide a diagnostic performance comparable with that of the standard protocol, decreasing radiation dose exposure and contrast material volume amount. ADVANCES IN KNOWLEDGE: Low-tube-voltage-setting protocol combined with ultra-low contrast agent volume (30 ml), by using new multidetector-row CT scanners, represents a feasible diagnostic tool to significantly reduce the radiation dose delivered to patients and to preserve renal function, while also maintaining adequate diagnostic quality images in assessment of aorta.


Assuntos
Angiografia/métodos , Doenças da Aorta/diagnóstico por imagem , Iohexol/análogos & derivados , Doenças Torácicas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Doenças Vasculares/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas de Imagem de Sincronização Cardíaca , Meios de Contraste/administração & dosagem , Estudos de Viabilidade , Feminino , Humanos , Iohexol/administração & dosagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador
11.
Mult Scler ; 20(2): 220-6, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23838177

RESUMO

OBJECTIVE: The objective of this paper is to identify clinical or magnetic resonance imaging (MRI) predictors of long-term clinical progression in a large cohort of multiple sclerosis (MS) patients. METHODS: A total of 241 relapsing-remitting (RR) MS patients were included in a nine-year follow-up (FU) study. The reference MRIs were acquired at baseline (BL) as part of a multicenter, cross-sectional, clinical-MRI study. Volumetric MRI metrics were measured by a fully automated, operator-independent, multi-parametric segmentation method. Clinical progression was evaluated as defined by: conversion from RR to secondary progressive (SP) disease course; progression of Expanded Disability Status Scale (EDSS); achievement and time to reach EDSS 4. RESULTS: We concluded that conversion from RR to SP (OR 0.79; CI 0.7-0.9), progression of EDSS (OR 0.85; CI 0.77-0.93), achievement of EDSS 4 (OR 0.8; CI 0.7-0.9), and time to reach EDSS 4 (HR 0.88; CI 0.82-0.94) were all predicted by BL gray matter (GM) volume and, except for progression of EDSS, by BL EDSS (respectively: (OR 2.88; CI 1.9-4.36), (OR 2.7; CI 1.7-4.2), (HR 3.86; CI 1.94-7.70)). CONCLUSIONS: BL GM volume and EDSS are the best long-term predictors of disease progression in RRMS patients with a relatively long and mild disease.


Assuntos
Esclerose Múltipla Recidivante-Remitente/complicações , Esclerose Múltipla Recidivante-Remitente/patologia , Adulto , Estudos Transversais , Avaliação da Deficiência , Progressão da Doença , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
12.
J Ultrasound ; 13(4): 158-63, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23397004

RESUMO

INTRODUCTION: Liver metastases often exhibit a hypervascular halo during the arterial phase of contrast-enhanced ultrasonography (CEUS). This finding has no correlates on baseline gray-scale imaging, and it has never been characterized. The aim of this study was to identify the features of this halo and determine whether it should be included in the ablation volume during thermal ablation procedures. MATERIALS AND METHODS: We prospectively enrolled 25 patients referred to our department for thermal ablation of liver metastases. Before treatment all patients underwent CEUS, and the maximum diameter of the metastatic lesion was measured before administration of the ultrasound contrast agent and during the arterial and portal venous phases of the contrast contrast-enhanced study. Maximum diameters in the different vascular phases were compared with the Turkey-Kramer test. Two biopsies were obtained from each lesion with a 21-gauge needle: 1) one from the center of the metastasis to confirm the diagnosis and 2) one from the hypervascular peripheral halo identified in the arterial phase at CEUS. RESULTS: The mean (±standard deviation) maximum lesion diameter was 2.67 ± 1.2 cm before contrast agent injection, 3.50 ± 1.4 cm during the arterial phase, and 2.71 ± 1.2 cm during the venous phase. The difference between maximum diameters measured before contrast enhancement and in the arterial phase was highly significant (mean: 0.84 ± 0.45 cm, p < 0.0001). Histological examination of halo specimens revealed inflammatory infiltrates with no evidence of tumor infiltration in 24/25 (96%) cases and normal hepatic parenchymal tissue in the 25th specimen. DISCUSSION: The hypervascular halo surrounding liver metastases during the arterial phase of CEUS represents a chronic inflammatory infiltrate, not tumor infiltration. However, since chronic inflammation appears to promote neovascularization and the production of tumoral growth factors, it seems wise to include the hypervascular halo in the intended-to-treat volume when planning the ablation procedure.

13.
Phys Rev Lett ; 101(19): 195004, 2008 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-19113279

RESUMO

We study the propagation of lower-hybrid-type resonance cones in a tenuous magnetized plasma, and, in particular, their interaction with, and reflection from, the plasma sheath near a conducting wall. The sheath is modeled as a vacuum gap whose width is given by the Child-Langmuir law. The application of interest is when the resonance cones are launched (parasitically) by an ion-cyclotron radio-frequency antenna in a typical rf-heated tokamak fusion experiment. We calculate the fraction of launched voltage in the resonance cones that is transmitted to the sheath, and show that it has a sensitive thresholdlike turn on when a critical parameter reaches order unity. Above threshold, the fractional voltage transmitted to the sheath is order unity, leading to strong and potentially deleterious rf-wall interactions in tokamak rf heating experiments. Below threshold, these interactions can be avoided.

14.
Phys Rev Lett ; 93(26 Pt 1): 265001, 2004 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-15697984

RESUMO

Propagating filaments of enhanced plasma density, or blobs, observed in 3D numerical simulations of a diverted, neutral-fueled tokamak are studied. Fluctuations of vorticity, electrical potential phi, temperature Te, and current density J parallel associated with the blobs have a dipole structure perpendicular to the magnetic field and propagate radially with large E x B drift velocities (>1 km/s). The simulation results are consistent with a 3D blob dynamics model that incorporates increased parallel plasma resistivity (from neutral cooling of the X-point region), blob disconnection from the divertor sheath, X-point closure of the current loops, and collisional physics to sustain the phi, Te, J parallel dipoles.

15.
Phys Rev Lett ; 90(19): 195001, 2003 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-12785951

RESUMO

A two-dimensional integral full-wave model is used to calculate poloidal forces driven by mode conversion in tokamak plasmas. In the presence of a poloidal magnetic field, mode conversion near the ion-ion hybrid resonance is dominated by a transition from the fast magnetosonic wave to the slow ion cyclotron wave. The poloidal field generates strong variations in the parallel wave spectrum that cause wave damping in a narrow layer near the mode conversion surface. The resulting poloidal forces in this layer drive sheared poloidal flows comparable to those in direct launch ion Bernstein wave experiments.

16.
J Neurosci ; 21(4): 1238-46, 2001 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11160394

RESUMO

States of increased metabolic demand such as fasting modulate hypothalamic neuropeptide gene expression and decrease circulating leptin levels. This study tested the hypotheses that fasting stimulates gene induction mediated by cAMP response element (CRE)-dependent increases in gene transcription and that fasting-induced decreases in leptin can regulate this CRE-mediated gene induction. Using C57BL/6J mice transgenic for a CRE-lacZ construct, an immunocytochemical study showed that fasting activated reporter gene expression in the hypothalamic arcuate nucleus (Arc) in a small subset of neurons and increased phosphorylation of CRE binding protein. The increase of beta-galactosidase expression caused by fasting was inhibited by a protein kinase A inhibitor, Rp-8-Br-cAMPS, when the compound was microinjected into the medial basal hypothalamus, and enhanced by intraperitoneal injection of selective phosphodiesterase inhibitors. In situ hybridization studies showed that neuropeptide Y (NPY) mRNA levels increased in the Arc during fasting, whereas proopiomelanocortin (POMC) mRNA levels decreased. Double labeling of mRNA and beta-galactosidase immunoreactivity in the fasted brain indicated that the subpopulation of the neurons expressing beta-galactosidase all produced NPY but not POMC. To study the possible involvement of decreased circulating leptin during starvation on CRE-mediated gene induction, leptin was administered intraperitoneally to fasted mice. Leptin significantly attenuated both beta-galactosidase expression and NPY gene expression stimulated by fasting, suggesting that leptin inhibits fasting-stimulated NPY gene expression at least in part through downregulation of CRE-mediated gene induction in the Arc. Leptin-induced modification of CRE-mediated gene induction in the Arc may play an essential role in the central regulation of feeding behavior and energy expenditure.


Assuntos
Núcleo Arqueado do Hipotálamo/metabolismo , Jejum/metabolismo , Regulação da Expressão Gênica/fisiologia , Leptina/metabolismo , Neurônios/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/citologia , Núcleo Arqueado do Hipotálamo/efeitos dos fármacos , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Genes Reporter , Leptina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/efeitos dos fármacos , Neuropeptídeo Y/genética , Neuropeptídeo Y/metabolismo , Inibidores de Fosfodiesterase/farmacologia , Fosforilação , Pró-Opiomelanocortina/genética , Pró-Opiomelanocortina/metabolismo , RNA Mensageiro/metabolismo , Sequências Reguladoras de Ácido Nucleico/fisiologia , Ativação Transcricional , beta-Galactosidase/biossíntese , beta-Galactosidase/genética
17.
Reprod Toxicol ; 11(4): 627-31, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9241685

RESUMO

Our objective was to investigate ejaculation and transport of sperm in the reproductive tract of male rats treated with an alpha-adrenergic receptor antagonist. Males were dosed (s.c.) with vehicle or 1.4 mg/kg prazosin. Sperm recovered in utero and ex vivo from the vas deferens and cauda epididymis were evaluated. Mating behavior and sperm motility were unaffected by prazosin. Prazosin treated males ejaculated fewer sperm (12.58 +/- 8.12 vs. 110.5 +/- 29.15 million), and the distal vas deferens contained fewer sperm (2.72 +/- 0.84 vs. 24.42 +/- 3.25 million) relative to controls. Prazosin-treated males had more sperm in the cauda epididymis relative to controls indicating inhibition of sperm transport to the vas deferens. These data demonstrate that inhibition of sperm transport from the cauda epididymis to the distal vas deferens is related to low ejaculate sperm counts in prazosin treated rats.


Assuntos
Antagonistas Adrenérgicos alfa/toxicidade , Prazosina/toxicidade , Motilidade dos Espermatozoides/efeitos dos fármacos , Animais , Ejaculação/efeitos dos fármacos , Feminino , Masculino , Ratos , Ratos Sprague-Dawley , Contagem de Espermatozoides
18.
Toxicol Appl Pharmacol ; 140(1): 146-53, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8806880

RESUMO

Decreased daily sperm production (DSP) and cauda epididymal sperm number (CESN) are some of the most sensitive effects of in utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure. The reduction in CESN cannot be fully accounted for by decreased spermatogenesis. To explain the decrease in CESN it was hypothesized that TCDD exposure increases the rate of sperm transit through the excurrent duct system, thereby decreasing the number of sperm in the system at any given time. Pregnant Holtzman rats were administered a single dose of TCDD (1.0 microgram/ kg,po) or vehicle on gestation day 15 and offspring were weaned on postnatal day (PND) 21. On PND 50, testicular sperm were labeled in five males per litter, from 30 control and 26 TCDD-exposed litters, by injecting 15 microCi [3H]thymidine into each testis, under general anesthesia. Sperm movement through the excurrent duct system was monitored daily 35-64 days post [3H]thymidine injection. On PNDs 92-93, TCDD exposure significantly decreased DSP/testis, corpus and cauda epididymis sperm numbers, vas deferens sperm number, and ejaculated sperm number by 28, 30, 36, 39, and 46%, respectively. The decreases in sperm number in the distal excurrent duct system were greater than the decrease in DSP, consistent with the hypothesis that TCDD exposure causes an effect other than decreased DSP that reduced epididymal and ejaculated sperm numbers. However, in utero and lactational TCDD exposure did not alter radiolabeled sperm transit time through the whole epididymis (15 days). With TCDD exposure causing no obvious alteration in sperm transit rate, a plausible explanation for the sperm loss is an increase in sperm phagocytosis in the excurrent duct system.


Assuntos
Epididimo/efeitos dos fármacos , Dibenzodioxinas Policloradas/toxicidade , Espermatogênese/efeitos dos fármacos , Animais , Feminino , Lactação , Masculino , Troca Materno-Fetal , Leite/química , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ratos Sprague-Dawley , Maturidade Sexual/efeitos dos fármacos , Contagem de Espermatozoides/efeitos dos fármacos
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