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1.
Vet Ophthalmol ; 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38424032

RESUMO

OBJECTIVE: To describe the clinical features of cats diagnosed with distichiasis and report on the outcomes following cryoepilation. ANIMALS STUDIED: Fifteen cats (27 eyes). PROCEDURES: Medical records of domestic cats with distichiasis that underwent a double freeze-thaw cycle with a -80°C cryoprobe applied to the palpebral conjunctiva, with hair then epilated were retrospectively studied. The patient signalment, distichiae locations, concurrent ocular diseases, recurrences, complications, and outcomes were recorded. RESULTS: The mean (std dev) age at the time of diagnosis and treatment was 2.2 years (2.8 years). All (15/15) cats were of the domestic shorthair (DSH) breed. Concurrent ocular findings at the initial examination were observed in 17/27 (63%) eyes, with upper lateral eyelid hypoplasia the most prevalent, present in 9/27 (33.3%) eyes. Recurrence of distichiae occurred in 8/27 (29.6%) eyes. The clinical presentation in the instances of recurrence was judged as asymptomatic and not of a clinical concern in 3/27 (11.1%) eyes, with a second procedure deemed necessary to alleviate symptoms in 5/27 (18.5%) eyes. All eyes treated with a second procedure had no recurrence of distichiae or symptoms. Complications following cryoepilation occurred in 4/27 (14.8%) eyes, with two cats developing bilateral entropion post-procedure. CONCLUSIONS: Treatment of distichiasis in cats utilizing cryoepilation was effective at alleviating symptoms, though some cats needed a second procedure. The development of post-procedural entropion was seen occasionally.

2.
Vet Ophthalmol ; 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38468143

RESUMO

OBJECTIVE: To describe ophthalmic findings in hospitalized canine and feline patients with tick paralysis (TP) and investigate possible predisposing factors. ANIMALS STUDIED: Forty-seven dogs and 28 cats hospitalized with TP assessed with an ophthalmic examination performed by an ABVO resident. METHODS: Dogs and cats were hospitalized with TP from October 2021 to January 2022 and had an ophthalmic examination performed by an ABVO resident. Patient signalment data, information regarding tick number and location, hospitalization duration, medications used, and patient paralysis grades were recorded. Statistical analysis was performed to correlate findings. RESULTS: Corneal ulcers developed in up to 34.8% of dogs and up to 42.9% of cats hospitalized with TP. An absent palpebral reflex ipsilaterally increased the odds of a concurrent corneal ulcer being present by 14.7× in dogs and 20.1× in cats (p < .0001). Palpebral reflexes were absent in 38.3% of dogs and 35.7% of cats hospitalized with TP and were correlated with more severe gait paralysis (p = .01) and respiratory paralysis (p = .005) in dogs, and respiratory paralysis in cats (p = .041). STT-1 findings <10 mm/min were present in 27.7% of dogs and 57.1% of cats examined and were associated with increasing gait paralysis (p = .017) and respiratory paralysis (p = .007) in dogs, and increasing gait paralysis in cats (p = .017). CONCLUSIONS: Simple corneal ulcers, loss of a complete palpebral reflex, and reduced STT-1 scores frequently occurred in dogs and cats hospitalized for TP. The frequency of these findings increased as the degree of patient paralysis increased.

3.
J Anim Physiol Anim Nutr (Berl) ; 101(3): 403-420, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27550521

RESUMO

High sodium levels in cat food have been controversial for a long time. Nonetheless, high sodium levels are used to enhance water intake and urine volume, with the main objective of reducing the risk of urolithiasis. This article is a review of current evidence of the putative risks and benefits of high dietary sodium levels. Its secondary aim is to report a possible safe upper limit (SUL) for sodium intake. The first part of the manuscript is dedicated to sodium physiology, with a focus on the mechanisms of sodium homeostasis. In this respect, there is only few information regarding possible interactions with other minerals. Next, the authors address how sodium intake affects sodium balance; knowledge of these effects is critical to establish recommendations for sodium feed content. The authors then review the consequences of changes in sodium intake on feline health, including urolithiasis, blood pressure changes, cardiovascular alterations and kidney disease. According to recent, long-term studies, there is no evidence of any deleterious effect of dietary sodium levels as high as 740 mg/MJ metabolizable energy, which can therefore be considered the SUL based on current knowledge.


Assuntos
Ração Animal/análise , Gatos/fisiologia , Dieta/veterinária , Sódio na Dieta/administração & dosagem , Fenômenos Fisiológicos da Nutrição Animal , Animais , Sódio na Dieta/efeitos adversos
4.
Nature ; 459(7250): 1114-7, 2009 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-19553996

RESUMO

The modern Eastern Equatorial Pacific (EEP) Ocean is a large oceanic source of carbon to the atmosphere. Primary productivity over large areas of the EEP is limited by silicic acid and iron availability, and because of this constraint the organic carbon export to the deep ocean is unable to compensate for the outgassing of carbon dioxide that occurs through upwelling of deep waters. It has been suggested that the delivery of dust-borne iron to the glacial ocean could have increased primary productivity and enhanced deep-sea carbon export in this region, lowering atmospheric carbon dioxide concentrations during glacial periods. Such a role for the EEP is supported by higher organic carbon burial rates documented in underlying glacial sediments, but lower opal accumulation rates cast doubts on the importance of the EEP as an oceanic region for significant glacial carbon dioxide drawdown. Here we present a new silicon isotope record that suggests the paradoxical decline in opal accumulation rate in the glacial EEP results from a decrease in the silicon to carbon uptake ratio of diatoms under conditions of increased iron availability from enhanced dust input. Consequently, our study supports the idea of an invigorated biological pump in this region during the last glacial period that could have contributed to glacial carbon dioxide drawdown. Additionally, using evidence from silicon and nitrogen isotope changes, we infer that, in contrast to the modern situation, the biological productivity in this region is not constrained by the availability of iron, silicon and nitrogen during the glacial period. We hypothesize that an invigorated biological carbon dioxide pump constrained perhaps only by phosphorus limitation was a more common occurrence in low-latitude areas of the glacial ocean.


Assuntos
Carbono/metabolismo , Carbono/química , Diatomáceas/metabolismo , Sedimentos Geológicos/química , Oceano Pacífico , Silício/análise , Fatores de Tempo
5.
J Intern Med ; 276(1): 25-40, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24708237

RESUMO

High-grade gliomas remain incurable and lethal. Through the availability of the stem-like cells responsible for glioblastoma (GB) formation, expansion, resilience and recurrence, the discovery of glioma cancer stem cells (GCSCs) is revolutionizing this field. GCSCs provide an unprecedented opportunity to reproduce and study GB pathophysiology more accurately. This critically emphasizes our ability to unambiguously identify, isolate and investigate cells that do qualify as GCSCs, to use them as a potential model that is truly predictive of GBs and of their regulation and response to therapeutic agents. We review this concept against the background of key findings on somatic, neural and solid tumour stem cells (SCs), also taking into account the emerging phenomenon of phenotypic SC plasticity. We suggest that basic approaches in these areas can be imported into the GCSC field, so that the same functional method used to identify normal somatic SCs becomes the most appropriate to define GCSCs. This, combined with knowledge of the cellular and molecular basis of normal adult neurogenesis, promises to improve the identification of GCSCs and of selective markers, as well as the development of innovative, more specific and efficacious antiglioma strategies.


Assuntos
Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Células-Tronco Neoplásicas/citologia , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos SCID , Células-Tronco Neoplásicas/patologia , Fenótipo , Nicho de Células-Tronco/fisiologia
6.
Pediatr Transplant ; 18(5): E140-5, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24815506

RESUMO

We report a 17-yr-old boy who developed a microangiopathic hemolytic anemia presumed secondary to tacrolimus shortly following a living-related donor renal transplant. This was initially managed by plasmapheresis. Reinstitution of calcineurin inhibition using cyclosporine led to recurrence of hemolysis, so an alternative agent was needed. He was commenced on monthly intravenous belatacept, with no further recurrence of the hemolysis, and subsequent stable graft function. Modulation via CTLA-4 offers an alternative immunosuppressive tactic if current regimens produce graft threatening adverse effects. The method of administration and frequency of dosage of belatacept also lends itself well to the high-risk period of adolescence and transition. We propose that belatacept may therefore also have utility in difficult cases complicated by poor concordance, common in the adolescent age group.


Assuntos
Anemia Hemolítica/tratamento farmacológico , Calcineurina/química , Imunoconjugados/uso terapêutico , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Transplante de Rim , Complicações Pós-Operatórias/prevenção & controle , Abatacepte , Adolescente , Anemia Hemolítica/etiologia , Antígeno B7-1/antagonistas & inibidores , Antígeno B7-2/antagonistas & inibidores , Antígeno CTLA-4/metabolismo , Rejeição de Enxerto , Hemólise , Humanos , Terapia de Imunossupressão/métodos , Doadores Vivos , Masculino , Plasmaferese , Recidiva , Tacrolimo/efeitos adversos , Resultado do Tratamento
7.
Aust Vet J ; 102(6): 296-305, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38369322

RESUMO

OBJECTIVE: To investigate the incidence and predisposing factors leading to the development of corneal ulcers and the loss of a palpebral reflex in hospitalised canine and feline patients with tick paralysis (TP). ANIMALS STUDIED: A total of 102 dogs and 100 cats retrospectively were assessed from previously hospitalised patients. METHODS: A retrospective cohort study was performed on 102 different canine and 100 different feline patients who were hospitalised for TP from October 2020-January 2022. Patient data were collected, and logistic regression was conducted to determine factors affecting the palpebral reflex and the development of corneal ulcers. RESULTS: Corneal ulcers occurred in 23/102 (22.5%) dogs during hospitalisation and were strongly associated with an incomplete palpebral reflex ipsilaterally during hospitalisation (P < 0.001), hospitalisation ≥3 days (P = 0.004), mechanical ventilation ≥3 days (P = 0.015) or a tick location cranial to C1 (P = 0.003). An incomplete palpebral reflex during hospitalisation was observed in 29/102 (28.4%) dogs and was significantly associated with decreasing patient weight (P = 0.018), increasing days hospitalised (P = 0.001), having a tick found cranial to C1 (P = 0.004), highest recorded GP grade (P = 0.01), highest recorded RP grade (P = 0.005), use of amoxycillin-clavulanic acid during hospitalisation (P = 0.002) and use of piperacillin/tazobactam during hospitalisation (P = 0.003). There was a significant association between the loss of a complete palpebral reflex and mortality during hospitalisation in dogs (OR = 4.5, P = 0.029). Corneal ulcers occurred in 10/100 (10.0%) cats during hospitalisation, and was significantly more likely to occur to an eye if an incomplete palpebral reflex was observed ipsilaterally during hospitalisation (OR = 20.1, P < 0.0001) and with increasing patient age (P = 0.019). The absence of a complete palpebral reflex during hospitalisation was observed in 18/10 (18.0%) cats and was significantly associated with increasing days hospitalised (P = 0.034). There was no significant association between the loss of a complete palpebral reflex and mortality during hospitalisation in cats. CONCLUSIONS: The frequency of corneal ulcers and loss of palpebral reflexes were significant in dogs and cats hospitalised by TP, with many factors contributing to the risk of these developing.


Assuntos
Doenças do Gato , Úlcera da Córnea , Doenças do Cão , Ixodes , Paralisia por Carrapato , Animais , Cães , Gatos , Doenças do Cão/tratamento farmacológico , Estudos Retrospectivos , Doenças do Gato/tratamento farmacológico , Paralisia por Carrapato/veterinária , Feminino , Masculino , Úlcera da Córnea/veterinária , Hospitalização/estatística & dados numéricos , Estudos de Coortes , Incidência , Fatores de Risco
8.
Mol Psychiatry ; 17(2): 124-31, 115, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21625231

RESUMO

Deep brain stimulation (DBS) has emerged as a powerful surgical therapy for the management of treatment-resistant movement disorders, epilepsy and neuropsychiatric disorders. Although DBS may be clinically effective in many cases, its mode of action is still elusive. It is unclear which neural cell types are involved in the mechanism of DBS, and how high-frequency stimulation of these cells may lead to alleviation of the clinical symptoms. Neurons have commonly been a main focus in the many theories explaining the working mechanism of DBS. Recent data, however, demonstrates that astrocytes may be active players in the DBS mechanism of action. In this review article, we will discuss the potential role of reactive and neurogenic astrocytes (neural progenitors) in DBS.


Assuntos
Astrócitos/fisiologia , Estimulação Encefálica Profunda/métodos , Células-Tronco Neoplásicas/fisiologia , Animais , Proliferação de Células , Epilepsia/terapia , Humanos , Modelos Biológicos , Transtornos dos Movimentos/terapia
9.
Appetite ; 70: 60-6, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23831015

RESUMO

Impulsivity is a multidimensional construct that has been linked with obesity. To explore profiles of impulsive behavior potentially associated with adolescent weight status, we measured multiple dimensions of impulsivity (delay discounting, sustained attention, and behavioral disinhibition) using laboratory behavioral tasks in a sample of adolescents (N=61). For comparison purposes, we also assessed self-reported impulsive behavior with the BIS-11-A. Participants differed in body mass index: obese (n=21), overweight (n=20), and healthy-weight (n=20). Obese and overweight adolescents were more impulsive on the measure of delay discounting than healthy-weight adolescents, but no difference was found between obese and overweight adolescents on this measure. Obese adolescents also were more impulsive on the measure of inattention compared to overweight and healthy-weight adolescents, who did not differ on this measure. Behavioral disinhibition had no association with weight status, nor did the self-report measure of impulsivity. The additive pattern of these findings for certain laboratory behavioral measures indicates that obese adolescents are more impulsive than their healthy-weight counterparts on two dimensions of behavior, whereas overweight adolescents are more impulsive on only one dimension. Consequently, adolescents who are impulsive on two dimensions of behavior (i.e., delay discounting and sustained attention) may be at greater risk of becoming obese rather than overweight compared to adolescents who are impulsive on only one dimension of behavior (i.e., delay discounting).


Assuntos
Comportamento do Adolescente , Peso Corporal , Comportamento Impulsivo/psicologia , Sobrepeso/psicologia , Obesidade Infantil/psicologia , Adolescente , Atenção , Índice de Massa Corporal , Tomada de Decisões/fisiologia , Feminino , Humanos , Masculino , Autorrelato
10.
Nature ; 444(7120): 761-5, 2006 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-17151667

RESUMO

Transformed, oncogenic precursors, possessing both defining neural-stem-cell properties and the ability to initiate intracerebral tumours, have been identified in human brain cancers. Here we report that bone morphogenetic proteins (BMPs), amongst which BMP4 elicits the strongest effect, trigger a significant reduction in the stem-like, tumour-initiating precursors of human glioblastomas (GBMs). Transient in vitro exposure to BMP4 abolishes the capacity of transplanted GBM cells to establish intracerebral GBMs. Most importantly, in vivo delivery of BMP4 effectively blocks the tumour growth and associated mortality that occur in 100% of mice after intracerebral grafting of human GBM cells. We demonstrate that BMPs activate their cognate receptors (BMPRs) and trigger the Smad signalling cascade in cells isolated from human glioblastomas (GBMs). This is followed by a reduction in proliferation, and increased expression of markers of neural differentiation, with no effect on cell viability. The concomitant reduction in clonogenic ability, in the size of the CD133+ population and in the growth kinetics of GBM cells indicates that BMP4 reduces the tumour-initiating cell pool of GBMs. These findings show that the BMP-BMPR signalling system--which controls the activity of normal brain stem cells--may also act as a key inhibitory regulator of tumour-initiating, stem-like cells from GBMs and the results also identify BMP4 as a novel, non-cytotoxic therapeutic effector, which may be used to prevent growth and recurrence of GBMs in humans.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Antígeno AC133 , Animais , Antígenos CD/metabolismo , Proteína Morfogenética Óssea 4 , Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas Morfogenéticas Ósseas/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Glioblastoma/metabolismo , Glioblastoma/patologia , Glicoproteínas/metabolismo , Humanos , Camundongos , Células-Tronco Neoplásicas/citologia , Peptídeos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transplante de Células-Tronco
11.
J Environ Monit ; 14(1): 155-64, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22130567

RESUMO

The concentrations of manganese (Mn) in the Upper River Severn (the Plynlimon catchments) are examined in relation to rainfall, cloud water, throughfall, stemflow and stream water concentrations where there is over 20 years of monitoring data available. Manganese concentrations are particularly low in rainfall and cloud water, with maximum concentrations occurring under low volumes of catch due to atmospheric "washout" of contaminants and dry deposition. There is strong Mn enrichment in throughfall and stemflow and this is probably linked to cycling through the vegetation. Manganese in the streams and groundwaters are primarily supplied from within-catchment sources. The highest concentrations occur within the tree canopy probably due to element cycling and in groundwaters due to mobilisation from the rock. Manganese concentrations in streams are at their lowest during spring and summer following long dry spells, with rapid increases following subsequent rain. There is no clear long-term trend in Mn concentration in the streams although there are increases in Mn concentrations for years when there is extensive felling of spruce plantation forest and in 1995 following a more extensive dry period. New high resolution monitoring picks up the effects of the rising limb of the hydrograph when concentrations rapidly increase, diurnal patterns during summer low-flow periods and contrasting dynamics between moorland and forested catchments.


Assuntos
Monitoramento Ambiental , Manganês/análise , Rios/química , Poluentes Químicos da Água/análise , Atmosfera/química , Agricultura Florestal/estatística & dados numéricos , Água Subterrânea/química , Cinética , Modelos Lineares , País de Gales , Poluição Química da Água/estatística & dados numéricos , Tempo (Meteorologia)
12.
Am J Vet Res ; 83(5): 434-442, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35175932

RESUMO

OBJECTIVE: To investigate the effects and duration of orally administered prednisolone on renal function evaluated by glomerular filtration rate (GFR) determination and creatinine (Cr) and symmetric dimethylarginine (SDMA) concentrations as well as on urinalysis, electrolytes, and hydric status in healthy dogs. ANIMALS: 14 healthy Beagles. PROCEDURES: In this prospective double-masked placebo-controlled study, dogs were randomized after baseline evaluation to receive a 7-day course of either prednisolone (1.5 to 2.0 mg/kg, PO, q 12 h) or a placebo. A repeated-measure design was performed, each dog participating in 4 successive sampling sessions. Clinical data, systolic blood pressure, CBC, and biochemical analyses including serum SDMA concentration, GFR determination, urine output quantification, and complete urinalysis were performed for all dogs the day before (D0) and at the end of steroid administration (D7) as well as 2 weeks (D21) and 4 weeks (D35) after the end of treatment. RESULTS: At D7, when compared with baseline, GFR increased significantly in treated dogs, whereas creatinine and SDMA concentrations decreased significantly. GFR and Cr but not SDMA modifications persisted significantly at D21. None of the variables differed significantly from baseline at D35. The OR of presenting an albumin band on urine electrophoresis was 2.4 times as high in treated versus control dogs (OR, 36; 95% CI, 1.8 to 719.4; P = 0.02). CLINICAL RELEVANCE: A short-term course of immune-suppressive prednisolone treatment in healthy dogs leads to a sustained but reversible renal hyperfiltration state. Modification in electrolytic variables can affect the clinical interpretation of blood work in such patients.


Assuntos
Doenças do Cão , Prednisolona , Animais , Biomarcadores , Creatinina , Cães , Eletrólitos , Taxa de Filtração Glomerular/veterinária , Rim/fisiologia , Prednisolona/farmacologia , Prednisolona/uso terapêutico , Estudos Prospectivos
13.
Glia ; 59(8): 1135-47, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21351156

RESUMO

Malignant glioma is among of the most devastating, and least curable, types of cancer. Since the re-emergence of the cancer stem cell hypothesis, much progress has been made towards elucidating the cellular origin of these tumors. The hypothesis that tumors are hierarchically organized, with a cancer stem cell at the top that shares defining features with somatic stem cells and provides therapeutic refractoriness properties, has put adult stem cells into the limelight as prime suspect for malignant glioma. Much confusion still exists, though, as to the particular cell type and processes that lead to oncogenic transformation. In this review, we will discuss recent developments and novel hypotheses regarding the origin of malignant gliomas, especially glioblastoma. In particular, we argue that glioblastoma is the result of different pathways originating in multiple sources that all ultimately converge in the same disease. Further attention is devoted to potential scenarios leading to transformation of different stem/progenitor cell types of the brain, and the probability and relevance of these scenarios for malignant tumorigenesis.


Assuntos
Neoplasias Encefálicas/patologia , Glioma/patologia , Células-Tronco Neoplásicas/fisiologia , Animais , Neoplasias Encefálicas/etiologia , Glioma/etiologia , Humanos
14.
J Environ Monit ; 13(5): 1255-63, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21442109

RESUMO

Ten years of monitoring of rainfall and streams in the remote acidic and acid sensitive moorland and afforested moorland of upland mid-Wales reveals concentrations of arsenic (As) typically <1 µg L(-1). On average, the lowest concentrations occur within rainfall and they have declined over time probably in response to reductions in global emissions. There is a corresponding reduction within the streams except for forested systems where concentrations up to doubled following clear-fell. Within the streams there are both annual cycling and diurnal cycling of As. The annual cycling gives maxima during the summer months and this probably reflects the importance of groundwater inputs and mineralisation/desorption from the surface soil layers. Correspondingly, the diurnal cycling occurs during the summer months at low flow periods with As concentrations highest in the afternoon/evening. For the urban/industrial basins of northern England with historically a much higher As deposition, land contamination and effluent discharges, comparative data indicate As concentrations around three fold higher: strong seasonal patterns are observed for the same reasons as with the uplands. Across the sites, the As concentrations are over an order of magnitude lower than that of environmental concern. Nonetheless, the results clearly show the effects of declining emissions on rainfall deposition and some indication of areas of historic contamination. Arsenic is mainly present in the <0.45 fraction, but cross-flow filtration indicates that approx. 43% is in the colloidal phase at the clean water sites, and 16% in the colloidal phase at the contaminated sites. Part of this colloidal component may well be associated with organic carbon.


Assuntos
Arsênio/análise , Chuva/química , Rios/química , Poluentes Químicos da Água/análise , Cidades , Monitoramento Ambiental , Fenômenos Geológicos , Solo/química , Poluentes do Solo/análise , Reino Unido , Ciclo Hidrológico , Poluição Química da Água/estatística & dados numéricos
15.
Anaerobe ; 17(6): 330-3, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21621624

RESUMO

Contamination of watercourses with fecal matter represents a significant risk to public health due to the associated risk from human pathogens (e.g. Escherichia coli O157, norovirus). In addition, water contamination may also perpetuate the re-infection cycle of human pathogens within domesticated and wild animal populations. While diffuse pollution from agricultural fields has been identified as a major source of these pathogens, the relationship between livestock grazing intensity and subsequent pathogen persistence in water is not well established. Our aim was to critically evaluate the importance of land use management on the activity of E. coli O157 in freshwaters collected from a livestock dominated catchment in the UK. We inoculated replicate batches of both filter-sterilised and non-sterile freshwaters with a chromosomally lux-marked E. coli O157 and monitored pathogen survival and activity over a 5 d period. Our results indicate that the greatest risk for pathogens entering freshwater is probably associated with high intensity livestock areas, although their subsequent survival is greatest in waters from low intensity livestock areas. We ascribe this enhanced persistence in the latter to reduced competition and predation within these aquatic environments. These results have serious implications for the reliability of pathogen risk exposure maps which are based on grazing intensity alone.


Assuntos
Criação de Animais Domésticos , Escherichia coli O157/isolamento & purificação , Atividades Humanas , Microbiologia da Água , Poluição da Água , Animais , Água Doce/microbiologia , Humanos , Viabilidade Microbiana , Modelos Teóricos , Fatores de Tempo , Reino Unido
16.
Cell Tissue Bank ; 12(3): 219-31, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20589432

RESUMO

Over 70,000 DBS devices have been implanted worldwide; however, there remains a paucity of well-characterized post-mortem DBS brains available to researchers. We propose that the overall understanding of DBS can be improved through the establishment of a Deep Brain Stimulation-Brain Tissue Network (DBS-BTN), which will further our understanding of DBS and brain function. The objectives of the tissue bank are twofold: (a) to provide a complete (clinical, imaging and pathological) database for DBS brain tissue samples, and (b) to make available DBS tissue samples to researchers, which will help our understanding of disease and underlying brain circuitry. Standard operating procedures for processing DBS brains were developed as part of the pilot project. Complete data files were created for individual patients and included demographic information, clinical information, imaging data, pathology, and DBS lead locations/settings. 19 DBS brains were collected from 11 geographically dispersed centers from across the U.S. The average age at the time of death was 69.3 years (51-92, with a standard deviation or SD of 10.13). The male:female ratio was almost 3:1. Average post-mortem interval from death to brain collection was 10.6 h (SD of 7.17). The DBS targets included: subthalamic nucleus, globus pallidus interna, and ventralis intermedius nucleus of the thalamus. In 16.7% of cases the clinical diagnosis failed to match the pathological diagnosis. We provide neuropathological findings from the cohort, and perilead responses to DBS. One of the most important observations made in this pilot study was the missing data, which was approximately 25% of all available data fields. Preliminary results demonstrated the feasibility and utility of creating a National DBS-BTN resource for the scientific community. We plan to improve our techniques to remedy omitted clinical/research data, and expand the Network to include a larger donor pool. We will enhance sample preparation to facilitate advanced molecular studies and progenitor cell retrieval.


Assuntos
Encéfalo/patologia , Estimulação Encefálica Profunda , Doença de Parkinson/patologia , Doença de Parkinson/terapia , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto
17.
Nature ; 430(6996): 195-8, 2004 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-15241411

RESUMO

Peatlands represent a vast store of global carbon. Observations of rapidly rising dissolved organic carbon concentrations in rivers draining peatlands have created concerns that those stores are beginning to destabilize. Three main factors have been put forward as potential causal mechanisms, but it appears that two alternatives--warming and increased river discharge--cannot offer satisfactory explanations. Here we show that the third proposed mechanism, namely shifting trends in the proportion of annual rainfall arriving in summer, is similarly unable to account for the trend. Instead we infer that a previously unrecognized mechanism--carbon dioxide mediated stimulation of primary productivity--is responsible. Under elevated carbon dioxide levels, the proportion of dissolved organic carbon derived from recently assimilated carbon dioxide was ten times higher than that of the control cases. Concentrations of dissolved organic carbon appear far more sensitive to environmental drivers that affect net primary productivity than those affecting decomposition alone.


Assuntos
Atmosfera/química , Dióxido de Carbono/metabolismo , Carbono/metabolismo , Solo/análise , Biodegradação Ambiental , Biomassa , Isótopos de Carbono , Ecossistema , Efeito Estufa , Fotossíntese , Chuva , Rios/química , Estações do Ano , Temperatura
18.
J Vet Intern Med ; 24(6): 1283-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21039866

RESUMO

BACKGROUND: Kinetic assessment of urea, the main end product of protein metabolism, could serve to assess protein catabolism in dogs with chronic kidney disease (CKD). Protein malnutrition and catabolism are poorly documented in CKD and they often are neglected clinically because of a lack of appropriate evaluation tools. HYPOTHESIS: Generation and excretion of urea are altered in dogs with CKD. ANIMALS: Nine dogs with spontaneous CKD (IRIS stages 2-4) and 5 healthy research dogs. METHODS: Endogenous renal clearance (Clrenal) of urea and creatinine was measured first. Exogenous plasma clearance (Clplasma, total body clearance) of the 2 markers then was determined by an IV infusion of urea (250-1,000 mg/kg over 20 minutes) and an IV bolus of creatinine (40 mg/kg). Extrarenal clearance (Clextra) was defined as the difference between Clplasma)and Clrenal. Endogenous urea generation was computed assuming steady-state conditions. RESULTS: Median Clrenal and Clextra of urea were 2.17 and 0.21 mL/min/kg in healthy dogs and 0.37 and 0.28 mL/min/kg in CKD dogs. The proportion of urea cleared by extrarenal route was markedly higher in dogs with glomerular filtration rate<1 mL/kg/min than in normal dogs, reaching up to 85% of the total clearance. A comparable pattern was observed for creatinine excretion, except in 1 dog, Clextra remained<20% of Clplasma. CONCLUSION: Extrarenal pathways of urea excretion are predominant in dogs with advanced CKD and justify exploring adjunctive therapies based on enteric nitrogen excretion in dogs. A trend toward increased urea generation may indicate increased catabolism in advanced CKD.


Assuntos
Doenças do Cão/metabolismo , Falência Renal Crônica/veterinária , Ureia/metabolismo , Animais , Cães , Feminino , Taxa de Filtração Glomerular/veterinária , Falência Renal Crônica/sangue , Falência Renal Crônica/metabolismo , Masculino , Ureia/sangue
19.
J Vet Intern Med ; 24(4): 809-18, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20561188

RESUMO

BACKGROUND: Reference intervals (RI) are pivotal in clinical pathology. The influence of breed on RI has been poorly documented in cats. HYPOTHESIS/OBJECTIVES: RI for plasma biochemistry variables are breed-dependent in cats. ANIMALS: Five hundred and thirty-six clinically healthy, fasted, client-owned cats from 4 breeds: Holly Birman (n=132), Chartreux (n=129), Maine Coon (n=139), and Persian (n=136). METHODS: Prospective observational study: Blood samples were collected from the cephalic vein into capillary tubes containing lithium heparin. Plasma glucose, urea, creatinine, total proteins, albumin, calcium, phosphate, sodium, potassium, chloride, and total CO2 concentrations and the activities of alanine aminotransferase and alkaline phosphatase were assayed with a dry slide biochemical analyzer. RI were defined as central 95% intervals bounded by the 2.5th and 97.5th percentiles. Data were analyzed by a linear mixed effects model with type I error rate of 0.05. RESULTS: A significant (P<.05) breed effect was observed for 9/13 variables. The magnitude of the differences between breeds could be clinically relevant for creatinine, glucose, and total protein. Age, body weight, sex, and housing conditions had significant (P<.05) breed-related effects on different variables. CONCLUSIONS AND CLINICAL IMPORTANCE: Breed-specific RI should be considered for cats.


Assuntos
Análise Química do Sangue/veterinária , Gatos/sangue , Gatos/genética , Animais , Feminino , Masculino , Valores de Referência
20.
Science ; 255(5052): 1707-10, 1992 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-1553558

RESUMO

Neurogenesis in the mammalian central nervous system is believed to end in the period just after birth; in the mouse striatum no new neurons are produced after the first few days after birth. In this study, cells isolated from the striatum of the adult mouse brain were induced to proliferate in vitro by epidermal growth factor. The proliferating cells initially expressed nestin, an intermediate filament found in neuroepithelial stem cells, and subsequently developed the morphology and antigenic properties of neurons and astrocytes. Newly generated cells with neuronal morphology were immunoreactive for gamma-aminobutyric acid and substance P, two neurotransmitters of the adult striatum in vivo. Thus, cells of the adult mouse striatum have the capacity to divide and differentiate into neurons and astrocytes.


Assuntos
Astrócitos/citologia , Corpo Estriado/citologia , Proteínas do Tecido Nervoso , Neurônios/citologia , Animais , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Meios de Cultura Livres de Soro , Fator de Crescimento Epidérmico/farmacologia , Imunofluorescência , Proteína Glial Fibrilar Ácida/metabolismo , Técnicas In Vitro , Proteínas de Filamentos Intermediários/metabolismo , Filamentos Intermediários/metabolismo , Camundongos , Nestina , Fosfopiruvato Hidratase/metabolismo
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