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1.
Biol Lett ; 13(11)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29118240

RESUMO

The major histocompatibility complex (MHC) plays a key role in vertebrate immunity, and pathogen-mediated selection often favours certain allelic combinations. Assessing potential mates' MHC profiles may provide receivers with genetic benefits (identifying MHC-compatible mates and producing optimally diverse offspring) and/or material benefits (identifying optimally diverse mates capable of high parental investment). Oscine songbirds learn songs during early life, such that song repertoire content can reflect population of origin while song complexity can reflect early life condition. Thus birdsong may advertise the singer's genetic dissimilarity to others in the population (and, presumably, compatibility with potential mates), or individual genetic diversity (and thus condition-dependent material benefits). We tested whether song repertoire content and/or complexity signal MHC class IIß dissimilarity and/or diversity in male song sparrows (Melospiza melodia). Pairwise dissimilarity in repertoire content did not predict MHC dissimilarity between males, suggesting that locally rare songs do not signal rare MHC profiles. Thus, geographical variation in song may not facilitate MHC-mediated inbreeding or outbreeding. Larger repertoires were associated with intermediate MHC diversity, suggesting intermediate rather than maximal MHC diversity is optimal. This could reflect trade-offs between resisting infection and autoimmune disorders. Song complexity may advertise optimal MHC diversity, a trait affecting disease resistance and capacity for parental care.


Assuntos
Complexo Principal de Histocompatibilidade/genética , Pardais/fisiologia , Vocalização Animal , Animais , Variação Genética , Masculino , Pardais/genética
2.
Proc Biol Sci ; 283(1842)2016 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-27807264

RESUMO

In jawed vertebrates, genes of the major histocompatibility complex (MHC) play a key role in immunity by encoding cell-surface proteins that recognize and bind non-self antigens. High variability at MHC suggests that these loci may also function in social signalling such as mate choice and kin recognition. This requires that MHC genotype covaries with some perceptible phenotypic trait. In mammals and fish, MHC is signalled chemically through volatile and non-volatile peptide odour cues, facilitating MHC-dependent mate choice and other behaviours. In birds, despite evidence for MHC-dependent mating, candidate mechanisms for MHC signalling remain largely unexplored. However, feather preen wax has recently been implicated as a potential source of odour cues. We examined whether the chemical composition of preen wax correlates with MHC class IIß genotypes of wild song sparrows (Melospiza melodia). Pairwise chemical distance reflected amino acid distance at MHC for male-female dyads, although not for same-sex dyads. Chemical diversity did not reflect MHC diversity. We used gas chromatography-mass spectrometry (GC-MS) to characterize preen wax compounds, and identified four wax esters that best reflect MHC similarity. Provided songbirds can detect variation in preen wax composition, this cue may allow individuals to assess MHC compatibility of potential mates.


Assuntos
Plumas/química , Complexo Principal de Histocompatibilidade , Aves Canoras/genética , Ceras/química , Animais , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Genótipo , Masculino , Odorantes
3.
Genet Mol Res ; 15(1)2016 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-26909968

RESUMO

Feeding is a complex behavior that is regulated by several internal mechanisms. Neuropeptides are able to survey quantities of stored energy and inform the organism if nutrient intake is required. In addition to this homeostatic regulation, a post-feeding reward system positively reinforces feeding. Slight adjustments to either system can tilt the balance to affect the energy reserves and survivorship in times of nutrient adversity. Neuropeptide F (NPF), a homolog of the mammalian neuropeptide Y, acts to induce feeding within the homeostatic regulation of this behavior. Drosophila and other insects bear a shorter form of NPF known as short NPF (sNPF) that can influence feeding. A neural hormone regulator, the dopamine transporter (DAT), works to clear dopamine from the synapses. This action may manipulate the post-feeding reward circuit in that lowered dopamine levels depress feeding, and excess dopamine levels encourage feeding. Here, we have overexpressed and impaired the activities of NPF, sNPF, and DAT in Drosophila, and we examined their ability to survive during conditions of amino acid starvation. Too much or too little NPF or sNPF, which are key players in homeostatic feeding regulation, leads to increased sensitivity to amino acid starvation and diminished survivorship when compared to controls. When DAT, a member of the post-feeding reward system, is either overexpressed or reduced via mutation, Drosophila has increased sensitivity to amino acid starvation. Taken together, these results indicate that subtle variation in the expression of key components of these systems impacts survivorship during adverse nutrient conditions.


Assuntos
Aminoácidos/deficiência , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Comportamento Alimentar/fisiologia , Neuropeptídeos/genética , Aminoácidos/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/metabolismo , Retroalimentação Fisiológica , Regulação da Expressão Gênica , Homeostase , Mutação , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Taxa de Sobrevida , Sinapses/metabolismo
4.
J Relig Health ; 54(6): 2005-19, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24912828

RESUMO

Scholarly research focusing on social psychological factors (e.g. mental health) and social environmental factors (e.g. childhood trauma) has found these measures to be correlated with suicidality. However, such literature has tended to overlook what may impact one's reasons for living. Using a sample of over 1,200 students from a Canadian university, the goal of the current study is to empirically test, by employing multivariate nested regression models (by levels of suicidal behaviour), known and relative unknown correlates with reasons for living, with a particular focus on strength of religious faith, which is a well-known predictor for suicidality, but less studied as a reason for living. Results show that, among students with serious suicidal ideation and/or a previous suicide attempt, the strongest predictor for student's reasons for living was strength of religious faith. Strength of religious faith has seldom been acknowledged or identified as an important measure in assessing one's reasons to live. These findings have implications for the role of religiosity among suicidality research, especially studies that focus on reasons for living.


Assuntos
Religião e Psicologia , Ideação Suicida , Tentativa de Suicídio/psicologia , Adolescente , Adulto , Canadá , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudantes/psicologia , Estudantes/estatística & dados numéricos , Suicídio , Tentativa de Suicídio/estatística & dados numéricos , Inquéritos e Questionários , Universidades , Adulto Jovem
5.
Neuropathol Appl Neurobiol ; 40(3): 284-95, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24003901

RESUMO

BACKGROUND: Optimal vascular function is vital for prevention of dementia. We hypothesized that elderly post-stroke survivors who preserve cognitive function show unperturbed cerebral microvasculature compared with those who develop dementia. METHODS: Using stereological spherical probe software, we compared the length density (Lv, cumulative vessel length per unit tissue volume) of hippocampal microvessels in post mortem brain tissue from post-stroke survivors, Alzheimer's disease (AD), vascular dementia (VaD) and normal ageing control subjects. We also assessed microvessel diameters in the same subjects. Microvessels were identified by markers of endothelial cells (glucose transporter 1; GLUT1), basement membrane (collagen IV; COL4) and smooth muscle cell α-actin (SMA). RESULTS: We found increased Lv of both GLUT1 and COL4 immunostained microvessels (P < 0.05) in the hippocampal CA1 region of post-stroke demented (PSD) and AD cases compared with post-stroke nondemented (PSND), control and VaD subjects. However, no changes were apparent in the CA2 region. We also noted significant increase in Lv in the entorhinal cortex of AD compared with PSND and PSD subjects. The mean diameter of microvessels was decreased in PSD, compared with PSND, as well as in AD and VaD compared with controls. Cumulative frequency analysis showed PSND subjects to have significantly greater proportion of microvessels with diameters, ranging from 7 to 12 µm. CONCLUSIONS: An increase in microvascular Lv in AD and PSD suggests either an increase in angiogenesis or the formation of newer microvessel loops in response to cerebral hypoperfusion. The decreased vessel diameters found in AD and VaD suggests increased vasoconstriction in dementia.


Assuntos
Demência/patologia , Hipocampo/irrigação sanguínea , Acidente Vascular Cerebral/patologia , Actinas/metabolismo , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Colágeno Tipo IV/metabolismo , Demência/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Humanos , Microvasos/patologia , Acidente Vascular Cerebral/metabolismo
6.
Eye (Lond) ; 37(12): 2554-2558, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36627444

RESUMO

BACKGROUND: The process of becoming visually impaired or blind is undoubtedly a highly emotional experience, requiring practical and psychological support. Information on mental health support provision in the UK across the sight-loss pathway, however, is largely unknown, especially amongst healthcare practitioners that are often sought after for advice: the referring optometrist and eye clinic liaison officer (ECLO). This study aims to ascertain the perceived accessibility and quality of mental health support across the sight-loss pathway. METHODS: Semi-structured individual interviews were conducted with patients with a diagnosed eye condition who had received care from a hospital eye service, referring optometrists, and ECLOs. Following interview transcription, results were synthesised in a narrative analysis. RESULTS: A total of 28 participants were included in the analysis, of which 17 were participants with various eye conditions, five were referring optometrists, and five were ECLOs. After analysis, three broad themes emerged: (1) The emotional trauma of diagnosis (2) Availability of mental health support; (3) The point where mental health support is most needed across the sight-loss pathway. Several patients reporting that they had received no offer of support nor were they signposted to any possible sources. Referring optometrists and ECLO's agreed. CONCLUSION: It is important that referring optometrists are aware of the need for mental health support services and can signpost to local support services including the third sector anytime during the referral process. Future large-scale, UK-wide research into referral practice and signposting for mental health support for patients is warranted, to identify how services can be improved in order to ensure that the wellbeing of patients is maintained.


Assuntos
Oftalmopatias , Optometristas , Optometria , Humanos , Saúde Mental , Cegueira , Oftalmopatias/diagnóstico , Oftalmopatias/terapia , Atenção à Saúde
7.
Cell Rep Med ; 4(12): 101332, 2023 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-38118420

RESUMO

The US Food and Drug Administration (FDA) approval of the selective RET inhibitors selpercatinib and pralsetinib has led to a paradigm change in the treatment of RET-altered lung and thyroid cancers through a higher response rate and a more tolerable safety and toxicity profile than multi-kinase inhibitors. Recently, selpercatinib has received a tissue-agnostic FDA approval for all RET-fusion-positive cancers, and pralsetinib has shown pan-cancer activity as well. Given the anticipated increase in the use of both drugs across multiple tumor types, it is crucial to recognize the possible side effects and approaches for their optimal management in order to maximize the clinical benefit for treated patients. In this review, we underscore potential toxicities associated with selective RET inhibitors and discuss strategies to mitigate them.


Assuntos
Neoplasias , Estados Unidos , Humanos , Neoplasias/tratamento farmacológico , Proteínas Proto-Oncogênicas c-ret/genética
8.
Clin Transplant ; 23(5): 589-99, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19719728

RESUMO

This exploratory, multicenter, open-label study evaluated the efficacy and safety of FTY720, as a part of an immunosuppressive regimen, in combination with everolimus and steroids in de novo renal transplant recipients at increased risk of delayed graft function (DGF). Patients received FTY720 (5 mg) and everolimus (4 mg) 2-12 h pre-transplantation, followed by 2.5 mg/d FTY720 and concentration-controlled everolimus (4-8 ng/mL) post-transplant for 12 months. Induction therapy was prohibited. After enrollment of 56 of the planned 200 patients between 2000 and 2002, the recruitment was terminated. The primary endpoint, rate of graft loss, or death at three months was 15.4% and the biopsy-confirmed acute rejection was 42.3%. Death or graft loss at 12 months in the DGF and non-DGF arms was 36.0% and 25.9%, respectively. The mean estimated creatinine clearance at three months was 63 and 55 mL/min in the non-DGF and DGF groups, respectively, while at 12 months it was 56 mL/min in both the groups. Although there was no comparator arm, the results from this exploratory study (compared with data from other phases II and III trials) indicated no apparent benefits of FTY720-based regimens for prevention of acute rejection and preservation of renal function in renal transplant recipients at high risk of DGF.


Assuntos
Função Retardada do Enxerto/prevenção & controle , Rejeição de Enxerto/prevenção & controle , Imunossupressores/uso terapêutico , Transplante de Rim , Propilenoglicóis/uso terapêutico , Sirolimo/análogos & derivados , Esfingosina/análogos & derivados , Adulto , Função Retardada do Enxerto/etiologia , Quimioterapia Combinada , Everolimo , Feminino , Cloridrato de Fingolimode , Rejeição de Enxerto/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Sirolimo/uso terapêutico , Esfingosina/uso terapêutico , Taxa de Sobrevida , Resultado do Tratamento
9.
Clin Lung Cancer ; 20(6): 435-441, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31303452

RESUMO

BACKGROUND: Higher cardiac radiotherapy (RT) doses when treating lung cancer are associated with worse overall survival (OS), although the direct association between cardiac dose and early cardiotoxicity is poorly understood. We hypothesized that RT doses to the heart and cardiac substructures are associated with under-reported early cardiotoxicity and worse OS. PATIENTS AND METHODS: We conducted an institutional retrospective review of lung cancer patients treated with conventionally fractionated RT from 2010 to 2015. Collected data included pre-RT cardiac risk factors, post-RT cardiotoxicities, and dose-volume parameters for cardiac substructures. Univariate and multivariate analyses were performed to identify predictors of cardiotoxicity and OS. RESULTS: Seventy-six cases were evaluated with 1.2 years median follow-up. Cardiotoxicities included atrial arrhythmia (n = 5), pericardial effusion (n = 16), and valvular disease (n = 1). In univariate analysis, significant dose-volume predictors for cardiotoxicity included mean RT dose to structure of interest, volume of structure of interest receiving ≥30 Gy RT dose, and volume of structure of interest receiving ≥45 Gy RT dose (V45) to the atria, ventricles, and pericardium. Higher ventricular V45 was associated with post-RT cardiotoxicity in multivariate analysis (hazard ratio [HR], 1.50; P = .027). Cardiotoxicity occurrence was a highly significant predictor of OS in multivariate analysis (HR, 12.7; P < .001), but higher ventricular V45 alone was not (HR, 0.78; P = .450). CONCLUSION: Early cardiac events were relatively common after lung cancer RT and associated with multiple cardiac dose-volume parameters. Occurrence of early cardiotoxicity was strongly associated with worse OS. In practice, early cardiotoxicity is under-reported, supporting the need for more detailed cardiac evaluations in high-risk patients to detect and address early cardiotoxicity.


Assuntos
Arritmias Cardíacas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Cardiotoxicidade/diagnóstico , Doenças das Valvas Cardíacas/diagnóstico , Neoplasias Pulmonares/radioterapia , Derrame Pericárdico/diagnóstico , Radioterapia/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Arritmias Cardíacas/etiologia , Carcinoma Pulmonar de Células não Pequenas/complicações , Fracionamento da Dose de Radiação , Feminino , Seguimentos , Doenças das Valvas Cardíacas/etiologia , Humanos , Neoplasias Pulmonares/complicações , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Derrame Pericárdico/etiologia , Prognóstico , Radiometria , Estudos Retrospectivos , Risco
10.
Neuropathol Appl Neurobiol ; 34(4): 403-11, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18005097

RESUMO

AIMS: Carotid sinus hypersensitivity (CSH) is an ageing-related autonomic disorder, rarely occurring before the age of 50 years but increasing in incidence thereafter. Clinical symptoms of CSH include falls and dizziness, thought to be precipitated by dysfunctional baroreflex responses. CSH is highly prevalent in Alzheimer's disease (AD), Parkinson's disease (PD) and dementia with Lewy bodies (DLB); diseases that are associated with variable degeneration of medullary autonomic nuclei which regulate baroreflex responses. Currently, there are no descriptions of the integrity of medullary autonomic nuclei in CSH. We hypothesized medullary autonomic degeneration is found in elderly patients with CSH. METHODS: Using in vitro digital imaging, we quantified the burden of tau, amyloid beta and alpha-synuclein in autonomic nuclei of 12 patients prospectively assessed with CSH (age 83 years) compared with 14 (80 years) control subjects. RESULTS: We found increased tau (P < 0.000) accumulation in baroreflex associated nuclei, but not the hypoglossal or raphe in the CSH patients. Medullary tau accumulation was not related to the development of AD in the CSH patients. Tau was colocalized to catecholaminergic neurones and occurred in the absence of neuronal loss. We found no difference in alpha-synuclein, amyloid beta or microglial numbers between the CSH cases and controls. CONCLUSIONS: We suggest that hyperphosphorylated tau accumulation particularly in tyrosine hydroxylase containing neurones may impair central regulation of baroreflex responses in patients with CSH. Future clinic-pathological investigations should reveal whether medullary degeneration is the cause of CSH symptoms.


Assuntos
Seio Carotídeo/patologia , Hipersensibilidade/patologia , Bulbo/patologia , Idoso , Idoso de 80 Anos ou mais , Peptídeos beta-Amiloides/metabolismo , Cadáver , Feminino , Humanos , Corpos de Lewy/patologia , Masculino , Microglia/patologia , Neurônios/patologia , Valores de Referência , Proteínas tau/metabolismo
11.
Scand J Surg ; 97(4): 280-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19211381

RESUMO

The purpose of this paper is to retrospectively review 234 consecutive cases of scaphoid fractures and nonunions treated using arthroscopy with the dorsal percutaneous implantation of a headless compression screw for healing and complications. Solid union of fracture is determined by CT scan. We identified 126 acute injuries, including 65 proximal pole fractures; 67 grossly displaced fractures; 12 trans-scaphoid perilunate dislocations including four trans-scaphoid trans-capitate fractures; and ten combined scaphoid and distal radius fractures. 108 scaphoid nonunions were identified. 98 were correctly aligned and ten had a humpback deformity which was correctable using arthroscopic assisted reduction techniques at the time of surgery. 82 presented with a fracture gap 2mm or greater requiring percutaneous bone grafting. 12 cases of avascular necrosis (AVN) were identified by MRI. 20 nonunions had surgery performed at other institutions. The mean time to surgery for the nonunions was 20 months. 99% union rate of acute scaphoid fractures was obtained by 12 weeks, as determined by CT scan. Two complications were identified (3%). One case of delayed healing was identified. this delayed union was treated with percutaneous bone grafting and continued on to heal uneventfully. The other complication was a case of volar trans-scaphoid peri-lunate dislocation. While the fracture healed, the patient developed a traumatic dislocation requiring a capitate-lunate arthrodesis. Treatment of scaphoid nonunions resulted in ten cases of delayed healing, which were treated with repeat percutaneous bone grafting. This represented a 9% complication rate. of the ten cases of delayed unions that were re-bone grafted, four failed to heal by nine months. This resulted in a 96% union rate of our nonunion group by nine months. when acute fracture healing was compared to nonunions the average healing of acute fractures as determined by CT scanning measuring trabecular bridging was 12 weeks, while the average healing of non-unions was 22 weeks. We conclude that the dorsal percutaneous treatment of scaphoid fractures and nonunions using arthroscopy is safe and effective. CT scans to evaluate scaphoid healing by measuring trabecular bridging at the fracture site was determined to be an excellent modality to evaluate scaphoid healing. While not witnessed in this series, the potential for complications requires proper training.


Assuntos
Artroscopia , Fraturas Ósseas/cirurgia , Fraturas não Consolidadas/cirurgia , Osso Escafoide/lesões , Adolescente , Adulto , Parafusos Ósseos , Consolidação da Fratura , Fraturas não Consolidadas/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Osteonecrose/cirurgia , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Osso Escafoide/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto Jovem
12.
J Vet Intern Med ; 22(2): 401-5, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18371030

RESUMO

BACKGROUND: Despite a lack of data regarding their efficacy, both caffeine and doxapram have been recommended for treatment of hypercapnia in equine neonates with central nervous system damage. HYPOTHESIS: Caffeine and doxapram alleviate hypercapnia in foals with hypoxic-ischemic encephalopathy. ANIMALS: Sixteen foals treated with either caffeine (n = 8) or doxapram (n = 8). METHODS: Information on age, body temperature, heart rate, respiratory rate, arterial blood gas parameters, duration of therapy, and outcome was abstracted from each medical record. RESULTS: Therapy with doxapram resulted in a significant decrease in partial pressure of carbon dioxide (PaCO2 [P= .004]), bicarbonate concentration (P= .002), and base excess (P= .005) compared with baseline values but failed to correct acidemia. In contrast, administration of caffeine did not result in significant changes from baseline values. The percentage decrease in PaCO2 and bicarbonate concentration was significantly greater in foals treated with doxapram than in foals treated with caffeine (P= .004). The proportions of foals that achieved the targeted PaCO2 (< or = 50 mmHg) were significantly higher in foals treated with doxapram than in foals treated with caffeine (P= .029). The proportion of survivors in the 2 treatment groups was not significantly different. CONCLUSIONS AND CLINICAL IMPORTANCE: Doxapram is more effective than caffeine for rapid correction of hypercapnia in foals with hypoxic-ischemic encephalopathy.


Assuntos
Cafeína/uso terapêutico , Estimulantes do Sistema Nervoso Central/uso terapêutico , Doxapram/uso terapêutico , Doenças dos Cavalos/tratamento farmacológico , Hipercapnia/veterinária , Hipóxia-Isquemia Encefálica/veterinária , Animais , Animais Recém-Nascidos , Feminino , Doenças dos Cavalos/etiologia , Cavalos , Hipercapnia/tratamento farmacológico , Hipercapnia/etiologia , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/tratamento farmacológico , Masculino , Estudos Retrospectivos
13.
Sci Rep ; 7(1): 6659, 2017 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-28751708

RESUMO

Materials with persistent photoconductivity (PPC) experience an increase in conductivity upon exposure to light that persists after the light is turned off. Although researchers have shown that this phenomenon could be exploited for novel memory storage devices, low temperatures (below 180 K) were required. In the present work, two-point resistance measurements were performed on annealed strontium titanate (SrTiO3, or STO) single crystals at room temperature. After illumination with sub-gap light, the resistance decreased by three orders of magnitude. This markedly enhanced conductivity persisted for several days in the dark. Results from IR spectroscopy, electrical measurements, and exposure to a 405 nm laser suggest that contact resistance plays an important role. The laser was then used as an "optical pen" to write a low-resistance path between two contacts, demonstrating the feasibility of optically defined, transparent electronics.

14.
Brain Res ; 1098(1): 196-203, 2006 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-16793027

RESUMO

We previously demonstrated that rats subjected to intermittent hypoxia (IH) by exposure to 10% O(2) for 4 h daily for 56 days in a normobaric chamber, developed pulmonary hypertension, right ventricular hypertrophy and wall-thickening in pulmonary arterioles, compared with normoxic (N) controls. These changes were greater in rats subjected to continuous hypoxia (CH breathing 10% O(2) for 56 days). Cerebral angiogenesis was demonstrated by immunostaining with glucose transporter 1 (GLUT1) antibody, in viable vessels, in CH and to a lesser degree in IH. In this study, adult Wistar rats were subjected to the same hypoxic regimes and given the nitric oxide synthase (NOS) inhibitor N(6)-nitro-L-arginine methyl ester (L-NAME) in drinking water (NLN, IHLN and CHLN regimes) to induce hypertension. There was significant systemic hypertension in NLN and IHLN rats, compared with N and IH, but surprisingly not in CHLN compared with CH. Hematocrit rose in all hypoxic groups (up to 79% in CHLN). There was no significant pulmonary hypertension in IHLN versus NLN rats, although there was asymmetric wall thickening in pulmonary arterioles. Cerebral GLUT1 immunoreactivity increased with L-NAME, with or without hypoxia, especially in CHLN rats, but conspicuously there was no evidence of angiogenesis in brains of IHLN compared with NLN rats. NOS blockade may attenuate the cerebral and pulmonary vascular changes of IH while augmenting cerebral angiogenesis in continuous hypoxia. However, whether cerebral effects are due to systemic hypertension or changes in cerebral nitric oxide production needs to be evaluated.


Assuntos
Sistema Cardiovascular/efeitos dos fármacos , Circulação Cerebrovascular/fisiologia , Inibidores Enzimáticos/farmacologia , Hipóxia Encefálica/metabolismo , Pulmão/efeitos dos fármacos , Óxido Nítrico Sintase/antagonistas & inibidores , Animais , Biomarcadores , Sistema Cardiovascular/enzimologia , Transportador de Glucose Tipo 1/metabolismo , Hipertrofia Ventricular Direita/metabolismo , Imuno-Histoquímica , Pulmão/enzimologia , Masculino , Microcirculação/efeitos dos fármacos , Microcirculação/fisiologia , NG-Nitroarginina Metil Éster/farmacologia , Circulação Pulmonar/efeitos dos fármacos , Circulação Pulmonar/fisiologia , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
Cancer Res ; 55(11): 2232-5, 1995 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-7757969

RESUMO

The original version of the Kent Micronite cigarette filter used crocidolite, a form of asbestos, from 1952 until at least mid-1956. Cigarettes from intact, unopened packs of the brand from this period were examined. One filter contained approximately 10 mg of crocidolite. Crocidolite structures were found in the mainstream smoke from the first two puffs of each cigarette smoked. At the observed rates of asbestos release, a person smoking a pack of these cigarettes each day would take in more than 131 million crocidolite structures longer than 5 microns in 1 year. These observations suggest that people who smoked the original version of this cigarette should be warned of their possible substantial exposure to crocidolite during the 1950s.


Assuntos
Asbesto Crocidolita/análise , Fumaça/análise , Asbesto Crocidolita/química , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Plantas Tóxicas , Nicotiana/química , Poluição por Fumaça de Tabaco
16.
Biochim Biophys Acta ; 1409(1): 25-38, 1998 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-9804876

RESUMO

The effects of single amino acid substitutions in the mobile loop region of the recombinant NAD(H)-binding domain (dI) of transhydrogenase have been examined. The mutations lead to clear assignments of well-defined resonances in one-dimensional 1H-NMR spectra. As with the wild-type protein, addition of NADH, or higher concentrations of NAD+, led to broadening and some shifting of the well-defined resonances. With many of the mutant dI proteins more nucleotide was required for these effects than with wild-type protein. Binding constants of the mutant proteins for NADH were determined by equilibrium dialysis and, where possible, by NMR. Generally, amino acid changes in the mobile loop region gave rise to a 2-4-fold increase in the dI-nucleotide dissociation constants, but substitution of Ala236 for Gly had a 10-fold effect. The mutant dI proteins were reconstituted with dI-depleted bacterial membranes with apparent docking affinities that were indistinguishable from that of wild-type protein. In the reconstituted system, most of the mutants were more inhibited in their capacity to perform cyclic transhydrogenation (reduction of acetyl pyridine adenine dinucleotide, AcPdAD+, by NADH in the presence of NADP+) than in either the simple reduction of AcPdAD+ by NADPH, or the light-driven reduction of thio-NADP+ by NADH, which suggests that they are impaired at the hydride transfer step. A cross-peak in the 1H-1H nuclear Overhauser enhancement spectrum of a mixture of wild-type dI and NADH was assigned to an interaction between the A8 proton of the nucleotide and the betaCH3 protons of Ala236. It is proposed that, following nucleotide binding, the mobile loop folds down on to the surface of the dI protein, and that contacts, especially from Tyr235 in a Gly-Tyr-Ala motif with the adenosine moiety of the nucleotide, set the position of the nicotinamide ring of NADH close to that of NADP+ in dIII to effect direct hydride transfer.


Assuntos
Sítios de Ligação/genética , NADP Trans-Hidrogenases/química , NAD/metabolismo , Rhodospirillum rubrum/enzimologia , Sequência de Aminoácidos , Proteínas de Bactérias/química , Cinética , Espectroscopia de Ressonância Magnética , Proteínas de Membrana/química , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida/genética , NADP/metabolismo , NADP Trans-Hidrogenases/genética , Nucleotídeos/metabolismo , Fragmentos de Peptídeos/química , Ligação Proteica/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética
17.
Undersea Hyperb Med ; 32(6): 437-43, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16509286

RESUMO

OBJECTIVE: A retrospective analysis of 42 patients with necrotizing soft tissue infections treated with adjunctive HBO2 to ascertain efficacy and safety. Overall mortality was 11.9% and morbidity 5%. SUMMARY BACKGROUND DATA: Necrotizing soft tissue infections have historically high rates of mortality and morbidity, including amputation. Common misconceptions that prevent widespread use of adjunctive HBO2 for this diagnosis include delays to surgery, increased morbidity, and significant complications. METHODS: Forty-two consecutive patients (average age 56.1) with necrotizing fasciitis presenting to a major referral center were treated with adjunctive HBO2 as part of an aggressive program of surgery, antibiotics, and critical care. Involved areas included the lower abdomen (15 patients), thigh and perineum (9 patients), flank (4 patients), lower leg (3 patients), and arm, shoulder, and axilla (2 patients). Co-morbidities included diabetes mellitus, chronic renal failure, intravenous drug abuse, peripheral vascular disease, and malignancy. RESULTS: Mortality was 11.9% (5 patients). Both amputations (a finger and a penis), occurred prior to transport to our facility. The average number of surgical debridements was 2.8 per patient; 1.25 performed prior to the start of HBO. The infectious process was controlled after an average of 7 HBO2 treatments were administered to ensure successful wound closure. Complications consisted of only mild ear barotrauma in 3 patients (7%), and confinement anxiety in 17 (41%) but did not prevent treatment. CONCLUSION: Compared to national reports of outcomes with "standard" regimens for necrotizing fasciitis, our experience with HBO2, adjunctive to comprehensive and aggressive management, demonstrates reduced mortality (34% v. 11.9%), and morbidity (amputations 50% v. 0%). The treatments were safe and no delays to surgery or interference with standard therapy could be attributed to HBO2.


Assuntos
Amputação Cirúrgica/estatística & dados numéricos , Fasciite Necrosante/mortalidade , Fasciite Necrosante/terapia , Oxigenoterapia Hiperbárica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada/métodos , Desbridamento/métodos , Fasciite Necrosante/microbiologia , Feminino , Humanos , Oxigenoterapia Hiperbárica/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
18.
J Neuropathol Exp Neurol ; 57(10): 895-904, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9786240

RESUMO

Molecular pathology has identified 2 distinct forms of neuronal inclusion body in Amyotrophic Lateral Sclerosis (ALS). ALS-type inclusions are skeins or small dense filamentous aggregates which can only be demonstrated by ubiquitin immunocytochemistry (ICC). In contrast hyaline conglomerates (HC) are large multifocal accumulations of neurofilaments. Previous reports have failed to clarify the distinction and relationship between these inclusions. Correlation of molecular pathology with sporadic and familial cases of ALS will detect specific associations between molecular lesions and defined genetic abnormalities; and determine the relevance of molecular events in familial cases to the pathogenesis of sporadic disease. We describe the molecular pathology of 5 ALS cases linked to abnormalities of the SOD1 gene, in comparison with a series of 73 sporadic cases in which SOD1-gene abnormalities were excluded. Hyaline conglomerate inclusions were detected only in the 2 cases with the SOD1 I113T mutation and showed a widespread multisystem distribution. In contrast ALS-type inclusions characterized sporadic cases (70/73) and were restricted to lower motor neurons. Hyaline conglomerates were not seen in sproadic cases. Confocal microscopic analysis and ICC shows that HC contain equally abundant phosphorylated and nonphosphorylated neurofilament epitopes, indicating that phosphorylation is not essential for their formation. In contrast neurofilament immunoreactivity is virtually absent from typical ALS-type inclusions. The SOD1-related cases all had marked corticospinal tract and dorsal column myelin loss. In 4 cases the motor cortex was normal or only minimally affected. This further illustrates the extent to which upper motor neuron damage in ALS is usually a distal axonopathy. Previously reported pathological accounts of SOD1-related familial ALS (FALS) are reviewed. Hyaline conglomerates are so far described in cases with mutations A4V, I113T and H48Q. In only 1 of 12 cases (H48Q) reported were both HC and ALS-type inclusions present in the same case. These findings suggest the possibility that the molecular pathology of neuronal inclusions in ALS indicates 2 distinct pathogenetic cascades.


Assuntos
Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Superóxido Dismutase/genética , Idoso , Encéfalo/patologia , Feminino , Humanos , Corpos de Inclusão/metabolismo , Corpos de Inclusão/patologia , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , Neurônios Motores/patologia , Mutação , Degeneração Neural/patologia , Medula Espinal/patologia
19.
J Neuropathol Exp Neurol ; 54(5): 673-9, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7666056

RESUMO

Synaptophysin immunoreactivity can be quantified by image analysis to evaluate loss of presynaptic terminals in human neurodegenerative diseases. The extent and regional distribution of such loss is reported in motor neuron disease (MND). Autopsy samples of spinal cord and cerebral cortex were examined from 28 cases of MND and 28 age and sex matched controls. The MND group included individuals with amyotrophic lateral sclerosis (17[ALS]), and progressive muscular atrophy (11[PMA]). In the spinal cord, there was significant reduction of presynaptic terminals in the lateral ventral horn (15%) in both the ALS (p < 0.01) and PMA (p < 0.05) groups. Perisomatic synaptophysin profiles on lower motor neurons are preserved late in the disease and are not related to corticospinal innervation. Less marked presynaptic loss was demonstrable more widely in the medial ventral, intermediate and dorsal spinal grey matter (10%) in both ALS (p = 0.03) and PMA (p = 0.05). In the cerebral cortex no synaptic loss was demonstrated in motor or anterior cingulate regions in any of the MND cases. Spinal degeneration in MND is associated with loss of presynaptic terminals in all grey matter regions. It is most marked in the limb motor neuron area and is independent of corticospinal tract degeneration. The cerebral pathology of ALS is not associated with significant loss of presynaptic terminals in the cortical areas studied.


Assuntos
Esclerose Lateral Amiotrófica/patologia , Córtex Cerebral/patologia , Doença dos Neurônios Motores/patologia , Medula Espinal/patologia , Sinaptofisina/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Especificidade de Órgãos , Substância Cinzenta Periaquedutal/patologia
20.
Neurology ; 42(8): 1477-80, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1641139

RESUMO

We describe a family in which infantile Werdnig-Hoffmann disease and adult-onset progressive muscular atrophy both occurred. The possibility of these two diseases developing within the same family by chance is unlikely, and several genetic hypotheses may be put forward to explain the association. We suggest that the molecular pathogenesis of these two subtypes of lower motor neuron degeneration may be linked. The genetic defect in the childhood spinal muscular atrophies has been mapped to chromosome 5q in close proximity to the microtubule-associated protein 1B locus. The association of diseases within this family suggests that chromosome 5q should also be studied in relation to adult-onset familial motor neuron disease.


Assuntos
Doença dos Neurônios Motores/genética , Atrofias Musculares Espinais da Infância/genética , Idoso , Envelhecimento , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Doença dos Neurônios Motores/complicações , Doença dos Neurônios Motores/fisiopatologia , Linhagem , Medula Espinal/patologia , Atrofias Musculares Espinais da Infância/complicações , Atrofias Musculares Espinais da Infância/patologia
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