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1.
Undersea Hyperb Med ; 49(3): 341-353, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36001567

RESUMO

Aim: Reports of fatal incidents in recreational scuba divers from carbon monoxide (CO) poisoning are rare. This study aimed to identify scuba fatalities in the Asia-Pacific region caused by breathing-gas contamination to better understand the likely sources of contamination and reduce such preventable deaths. Methods: A hand search of Project Stickybeak reports, subsequent Australian fatality series reports, and of published New Zealand diving fatality reports and associated data was conducted, as well as key word searches of the National Coronial Information System for scuba fatalities in Australia and New Zealand. Cases identified were matched with the Australasian Diving Safety Foundation diving fatality database. Available reports were examined. Results: Four scuba deaths resulting from CO poisoning were identified from 645 scuba fatalities, including one report from each of Australia, New Zealand, Singapore, and the Maldives. A near-fatal incident was also identified in Indonesia. Two of the fatal incidents and the near-fatal incident involved internal combustion engine exhaust gases from the compressor system or elsewhere entering the air intake. Two deaths likely resulted from combustion within compressor systems. Conclusions: Scuba fatalities from CO poisoning are uncommon, albeit likely under-reported. Sources of CO include exhaust gases entering the compressor and CO production by pyrolysis or gasification within the compressor or its filter system. Preventive measures include proper installation (including positioning of the air intake relative to combustion exhaust), appropriate maintenance, fitting of pressure-maintaining valves and avoidance of overheating. Formal training of compressor operators, improved diver education, mandatory requirements for installation compliance assessments, safety inspections, and the use of carbon monoxide alarms are recommended.


Assuntos
Intoxicação por Monóxido de Carbono , Mergulho , Afogamento , Austrália , Monóxido de Carbono , Intoxicação por Monóxido de Carbono/epidemiologia , Intoxicação por Monóxido de Carbono/etiologia , Intoxicação por Monóxido de Carbono/prevenção & controle , Causas de Morte , Humanos , Emissões de Veículos
2.
Pract Neurol ; 18(2): 134-136, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29288212

RESUMO

Cerebral arterial gas embolism is a recognised complication of endovascular intervention with an estimated incidence of 0.08%. Its diagnosis is predominantly clinical, supported by neuroimaging. The treatment relies on alleviating mechanical obstruction and reversing the proinflammatory processes that contribute to tissue ischaemia. Hyperbaric oxygen therapy is an effective treatment and has multiple mechanisms to reverse the pathological processes involved in cerebral arterial gas embolism. Symptomatic cerebral arterial gas embolism is a rare complication of endovascular intervention for acute ischaemic stroke. Although there are no previous descriptions of its successful treatment with hyperbaric oxygen therapy following mechanical thrombectomy, this is likely to become more common as mechanical thrombectomy is increasingly used worldwide to treat acute ischaemic stroke.


Assuntos
Embolia Aérea/etiologia , Embolia Aérea/terapia , Oxigenoterapia Hiperbárica/métodos , Embolia Intracraniana/etiologia , Embolia Intracraniana/terapia , Trombólise Mecânica/efeitos adversos , Idoso , Feminino , Humanos
3.
Cochrane Database Syst Rev ; 1: CD007937, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25879088

RESUMO

BACKGROUND: Hyperbaric oxygen therapy (HBOT) involves the therapeutic administration of 100% oxygen in a pressure chamber at pressures above one atmosphere absolute. This therapy has been used as an adjunct to surgery and antibiotics in the treatment of patients with necrotizing fasciitis with the aim of reducing morbidity and mortality. OBJECTIVES: To review the evidence concerning the use of HBOT as an adjunctive treatment for patients with necrotizing fasciitis (NF). Specifically, we wish to address the following questions.1. Does administration of HBOT reduce mortality or morbidity associated with NF?2. What adverse effects are associated with use of HBOT in the treatment of individuals with NF? SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE Ovid (1966 to September 2014); the Cumulative Index to Nursing and Allied Health Literature (CINAHL) Ovid (1982 to September 2014); EMBASE Ovid (1980 to September 2014); and the Database of Randomised Controlled Trials in Hyperbaric Medicine (DORCTHIM, M Bennett) (from inception to September 2014). In addition, we performed a systematic search of specific hyperbaric literature sources. This included handsearching of relevant hyperbaric textbooks; hyperbaric journals (Hyperbaric Medicine Review, South Pacific Underwater Medicine Society Journal, European Journal of Underwater and Hyperbaric Medicine, Aviation Space and Environmental Medicine Journal); and conference proceedings of the major hyperbaric societies (Undersea and Hyperbaric Medical Society, South Pacific Underwater Medicine Society, European Underwater and Baromedical Society, International Congress of Hyperbaric Medicine). SELECTION CRITERIA: We included all randomized and pseudo-randomized trials (trials in which an attempt at randomization has been made but the method was inappropriate, for example, alternate allocation) that compared the effects of HBOT with the effects of no HBOT (no treatment or sham) in the treatment of children and adults with necrotizing fasciitis. DATA COLLECTION AND ANALYSIS: We planned independent data collection by two review authors using standardized forms. MAIN RESULTS: We found no trials that met the inclusion criteria. AUTHORS' CONCLUSIONS: This systematic review failed to locate relevant clinical evidence to support or refute the effectiveness of HBOT in the management of necrotizing fasciitis. Good quality clinical trials are needed to define the role, if any, of HBOT in the treatment of individuals with necrotizing fasciitis.


Assuntos
Fasciite Necrosante/terapia , Oxigenoterapia Hiperbárica/métodos , Humanos
4.
Sci Adv ; 10(23): eadn6056, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38838149

RESUMO

Extensive ice coverage largely prevents investigations of Antarctica's unglaciated past. Knowledge about environmental and tectonic development before large-scale glaciation, however, is important for understanding the transition into the modern icehouse world. We report geochronological and sedimentological data from a drill core from the Amundsen Sea shelf, providing insights into tectonic and topographic conditions during the Eocene (~44 to 34 million years ago), shortly before major ice sheet buildup. Our findings reveal the Eocene as a transition period from >40 million years of relative tectonic quiescence toward reactivation of the West Antarctic Rift System, coinciding with incipient volcanism, rise of the Transantarctic Mountains, and renewed sedimentation under temperate climate conditions. The recovered sediments were deposited in a coastal-estuarine swamp environment at the outlet of a >1500-km-long transcontinental river system, draining from the rising Transantarctic Mountains into the Amundsen Sea. Much of West Antarctica hence lied above sea level, but low topographic relief combined with low elevation inhibited widespread ice sheet formation.

5.
Diving Hyperb Med ; 53(2): 147-150, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37365133

RESUMO

A 53-year-old woman with a HeartMate III left ventricular assist device (LVAD) was successfully treated under hyperbaric conditions for haemorrhagic cystitis. The HeartMate III LVAD inserted in this patient had not previously been tested or certified for use under hyperbaric conditions. To our knowledge this is the first report of the HeartMate III LVAD being used to support a patient undergoing hyperbaric treatment. The overview detailed here of the safety and technical aspects of managing this patient for hyperbaric treatment was possible due to the collaboration of a multi-disciplinary team. We believe that our experience has demonstrated a pathway to safe hyperbaric treatment of patients dependent upon a HeartMate III LVAD.


Assuntos
Insuficiência Cardíaca , Coração Auxiliar , Oxigenoterapia Hiperbárica , Feminino , Humanos , Pessoa de Meia-Idade , Insuficiência Cardíaca/terapia , Insuficiência Cardíaca/etiologia , Coração Auxiliar/efeitos adversos
6.
Am J Hum Genet ; 85(5): 581-92, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19853238

RESUMO

Bestrophin-1 is preferentially expressed at the basolateral membrane of the retinal pigmented epithelium (RPE) of the retina. Mutations in the BEST1 gene cause the retinal dystrophies vitelliform macular dystrophy, autosomal-dominant vitreochoroidopathy, and autosomal-recessive bestrophinopathy. Here, we describe four missense mutations in bestrophin-1, three that we believe are previously unreported, in patients diagnosed with autosomal-dominant and -recessive forms of retinitis pigmentosa (RP). The physiological function of bestrophin-1 remains poorly understood although its heterologous expression induces a Cl--specific current. We tested the effect of RP-causing variants on Cl- channel activity and cellular localization of bestrophin-1. Two (p.L140V and p.I205T) produced significantly decreased chloride-selective whole-cell currents in comparison to those of wild-type protein. In a model system of a polarized epithelium, two of three mutations (p.L140V and p.D228N) caused mislocalization of bestrophin-1 from the basolateral membrane to the cytoplasm. Mutations in bestrophin-1 are increasingly recognized as an important cause of inherited retinal dystrophy.


Assuntos
Canais de Cloreto/genética , Proteínas do Olho/genética , Mutação de Sentido Incorreto , Epitélio Pigmentado da Retina/patologia , Retinose Pigmentar/etiologia , Retinose Pigmentar/genética , Sequência de Aminoácidos , Bestrofinas , Linhagem Celular , Cromossomos Humanos Par 11 , Sequência Conservada , Éxons , Feminino , Genes Dominantes , Genes Recessivos , Ligação Genética , Homozigoto , Humanos , Rim/citologia , Escore Lod , Masculino , Dados de Sequência Molecular , Núcleo Familiar , Linhagem , Polimorfismo de Nucleotídeo Único , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Homologia de Sequência de Aminoácidos
7.
HPB (Oxford) ; 14(2): 103-14, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22221571

RESUMO

BACKGROUND: Approaches to increase organ availability for orthotopic liver transplantation (OLT) often result in the procurement of marginal livers that are more susceptible to ischaemia, preservation and reperfusion injury (IPRI). METHODS: The effects of post-OLT hyperbaric oxygen (HBO) therapy on IPRI in a syngeneic rat OLT model were examined at various time-points. The effects of IPRI and HBO on hepatocyte necrosis, apoptosis, proliferation, and sinusoidal morphology and ultrastructure were assessed. RESULTS: Post-OLT HBO therapy significantly reduced the severity of IPRI; both apoptosis [at 12 h: 6.4 ± 0.4% in controls vs. 1.6 ± 0.7% in the HBO treatment group (p < 0.001); at 48 h: 2.4 ± 0.2% in controls vs. 0.4 ± 0.1% in the HBO treatment group (p < 0.001)] and necrosis [at 12 h: 18.7 ± 1.8% in controls vs. 2.4 ± 0.4% in the HBO treatment group (p < 0.001); at 48 h: 8.5 ± 1.3% in controls vs. 3.4 ± 0.9% in the HBO treatment group (P= 0.019)] were decreased. Serum alanine transaminase was reduced [at 12 h: 1068 ± 920 IU/l in controls vs. 370 ± 63 IU/l in the HBO treatment group (P= 0.030); at 48 h: 573 ± 261 IU/l in controls vs. 160 ± 10 IU/l in the HBO treatment group (P= 0.029)]. Treatment with HBO also promoted liver regeneration [proliferation at 12 h: 4.5 ± 0.1% in controls vs. 1.0 ± 0.3% in the HBO treatment group (p < 0.001); at 48 h: 8.6 ± 0.7% in controls vs. 2.9 ± 0.2% in the HBO treatment group (p < 0.01)] and improved sinusoidal diameter and microvascular density index. CONCLUSIONS: Hyperbaric oxygen therapy has persistent positive effects post-OLT that may potentially transfer into clinical practice.


Assuntos
Oxigenoterapia Hiperbárica , Transplante de Fígado/efeitos adversos , Fígado/irrigação sanguínea , Fígado/cirurgia , Traumatismo por Reperfusão/prevenção & controle , Animais , Apoptose , Biomarcadores/sangue , Proliferação de Células , Modelos Animais de Doenças , Fígado/ultraestrutura , Regeneração Hepática , Masculino , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Necrose , Ratos , Ratos Endogâmicos Lew , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/patologia , Índice de Gravidade de Doença , Fatores de Tempo
8.
Sci Rep ; 12(1): 17272, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36241642

RESUMO

Porphyry-type deposits are a vital source of green technology metals such as copper and molybdenum. They typically form in subduction-related settings from large, long-lived magmatic systems. The most widely accepted model for their formation requires that mantle-derived magmas undergo an increase in volatiles and ore-forming constituents in mid- to lower crustal reservoirs over millions of years, however, this is mostly based on observations from shallow, sporadically exposed parts of porphyry systems. To examine this paradigm, we have evaluated the timeframe and geochemical signatures of magmatism in a ~ 8 km palaeodepth cross-section through plutonic and volcanic rocks of the classic Yerington magmatic system, Nevada. We show that the magmas in the upper parts of the system (< 8 km) underwent a major and rapid change in chemistry over a period of < 200 kyrs that is coincident with the initiation of ore formation. We attribute this change to a shift from extraction of quartz monzodiorite and quartz monzonite magmas evolving in mid-crustal reservoirs, and that had relatively poor ore-forming potential, to extraction of volatile-rich granitic magmas from greater (~ 30 km) depths. As the granites crystallised, late stage melts were intruded through the carapace as aplite dykes which contain traceable expressions of the porphyry deposit-forming fluids. The rapid nature of the shift in ore-forming potential narrows the temporal-geochemical footprint of magmas associated with porphyry mineralisation and provides new constraints for exploration models.

9.
Diving Hyperb Med ; 52(3): 164-174, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36100927

RESUMO

INTRODUCTION: Hyperbaric oxygen treatment (HBOT) is sometimes used in the management of open fractures and severe soft tissue crush injury, aiming to reduce complications and improve outcomes. METHODS: Patients with open tibial fractures were randomly assigned within 48 hours of injury to receive standard trauma care or standard care plus 12 sessions of HBOT. The primary outcome was the incidence of necrosis or infection or both occurring within 14 days of injury. RESULTS: One-hundred and twenty patients were enrolled. Intention to treat primary outcome occurred in 25/58 HBOT assigned patients and 34/59 controls (43% vs 58%, odds ratio (OR) 0.55, 95% confidence interval (CI) 0.25 to 1.18, P = 0.12). Tissue necrosis occurred in 29% of HBOT patients and 53% of controls (OR 0.35, 95% CI 0.16 to 0.78, P = 0.01). There were fewer late complications in patients receiving HBOT (6/53 vs 18/52, OR 0.22, 95% CI 0.08 to 0.64, P = 0.007) including delayed fracture union (5/53 vs 13/52, OR 0.31, 95% CI 0.10 to 0.95, P = 0.04). Quality of life measures at one and two years were superior in HBOT patients. The mean score difference in short form 36 was 2.90, 95% CI 1.03 to 4.77, P = 0.002, in the short musculoskeletal function assessment (SMFA) was 2.54, 95% CI 0.62 to 4.46, P = 0.01; and in SMFA daily activities was 19.51, 95% CI 0.06 to 21.08, P = 0.05. CONCLUSIONS: In severe lower limb trauma, early HBOT reduces tissue necrosis and the likelihood of long-term complications, and improves functional outcomes. Future research should focus on optimal dosage and whether HBOT has benefits for other injury types.


Assuntos
Fraturas Expostas , Oxigenoterapia Hiperbárica , Fraturas Expostas/terapia , Humanos , Extremidade Inferior , Necrose , Qualidade de Vida
10.
Am J Hum Genet ; 82(1): 19-31, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18179881

RESUMO

We describe a distinct retinal disorder, autosomal-recessive bestrophinopathy (ARB), that is consequent upon biallelic mutation in BEST1 and is associated with central visual loss, a characteristic retinopathy, an absent electro-oculogram light rise, and a reduced electroretinogram. Heterozygous mutations in BEST1 have previously been found to cause the two dominantly inherited disorders, Best macular dystrophy and autosomal-dominant vitreoretinochoroidopathy. The transmembrane protein bestrophin-1, encoded by BEST1, is located at the basolateral membrane of the retinal pigment epithelium in which it probably functions as a Cl(-) channel. We sequenced BEST1 in five families, identifying DNA variants in each of ten alleles. These encoded six different missense variants and one nonsense variant. The alleles segregated appropriately for a recessive disorder in each family. No clinical or electrophysiological abnormalities were identified in any heterozygotes. We conducted whole-cell patch-clamping of HEK293 cells transfected with bestrophin-1 to measure the Cl(-) current. Two ARB missense isoforms severely reduced channel activity. However, unlike two other alleles previously associated with Best disease, cotransfection with wild-type bestrophin-1 did not impair the formation of active wild-type bestrophin-1 channels, consistent with the recessive nature of the condition. We propose that ARB is the null phenotype of bestrophin-1 in humans.


Assuntos
Canais de Cloreto/genética , Proteínas do Olho/genética , Doenças Retinianas/genética , Adolescente , Adulto , Sequência de Aminoácidos , Bestrofinas , Linhagem Celular , Criança , Pré-Escolar , Canais de Cloreto/química , Códon sem Sentido , Proteínas do Olho/química , Feminino , Genes Recessivos , Humanos , Masculino , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Transfecção
11.
Sci Rep ; 10(1): 4128, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139759

RESUMO

Much evidence points to a dramatic thinning of East Asian lithosphere during the Mesozoic, but with little precision on when, or over what time scale. Using geochemical constraints, we examine an extensive compilation of dated volcanic samples from Russia, Mongolia and North China to determine when the lithosphere thinned and how long that process took. Geochemical results suggest that magmatism before 107 Ma derived from metasomatised subcontinental lithospheric mantle (SCLM), whereas after 107 Ma, melt predominantly derived from an asthenospheric source. The switch to an asthenospheric magma source at ~107 Ma occurred in both Mongolia and North China (>1600 km apart), whereas in eastern Russia the switch occurred a little later (~85 Ma). Such a dramatic change to an asthenospheric contribution appears to have taken, from beginning to end, just ~30 Myrs, suggesting this is the duration for lithospheric mantle weakening and removal. Subsequent volcanism, through the Cenozoic in Mongolia and North China does not appear to include any contribution from the removed SCLM, despite melts predominantly deriving from the asthenosphere.

12.
J Insect Sci ; 9: 1-6, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20050816

RESUMO

Increasing international trade and tourism have led to an increase in the introduction of exotic pests that pose a considerable economic threat to the agro-ecosystems of importing countries. Scale insects (Sternorryncha: Coccoidea) may be contaminants of export consignments from the South African deciduous fruit industry to the European Union, Israel, United Kingdom and the United States, for example. Infestations of immature scale insects found on South African fruit destined for export have resulted in increasing rates of rejection of such consignments. To identify the risk posed by scale insect species listed as phytosanitary pests on table grapes to the abovementioned importing countries, a field survey was undertaken in 2004-2005 in vineyards throughout all grape-producing regions in South Africa. Coccoidea species found during the current field survey were Planococcus ficus (Signoret), Pseudococcus longispinus (Targioni Tozzetti), Coccus hesperidum L. and Nipaecoccus viridis (Newstead). With the exception of Pl. ficus, which has only been collected from Vitis vinifera (Vitaceae) and Ficus carica (Moraceae) in South Africa, these species are polyphagous and have a wide host range. None of the scale insect species found to occur in vineyards in South Africa pose a phytosanitary risk to countries where fruit are exported except for Ferrisia malvastra (McDaniel) and N. viridis that have not been recorded in the USA. All scale insects previously found in vineyards in South Africa are listed and their phytosanitary status discussed. The results of the survey show that the risk of exporting scale insect pests of phytosanitary importance on table grapes from South Africa is limited.


Assuntos
Hemípteros/fisiologia , Vitis/parasitologia , Agricultura , Animais , Parasitologia de Alimentos , África do Sul
13.
Biochem Biophys Res Commun ; 373(4): 550-4, 2008 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-18588858

RESUMO

The transport stoichiometry of the electrogenic sodium-bicarbonate cotransporter (SLC4A5 or NBCe2) in mouse choroid plexus was examined. Whole-cell recording methods measured the currents carried by the NBCe2, using experimental solutions determined to minimise the contributions of the other ion conductances present. Increases in outward current were observed when 21.2 mM HCO3(-) was added to the bath solution in the presence of Na(+), but not N-methyl-D-glucamine. This HCO3(-)-induced current was completely abolished by 500 microM 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid. The reversal potential for the HCO3(-)-induced current was -95.1+/-7.1 mV (n=11), a value which corresponds to a NBCe2 transport stoichiometry of 3 HCO3(-) with 1 Na(+). The NBCe2, with this stoichiometry, will mediate the efflux of HCO3(-) and Na(+) from the cell into the cerebrospinal fluid at the apical membrane of the choroid plexus.


Assuntos
Bicarbonatos/metabolismo , Plexo Corióideo/metabolismo , Simportadores de Sódio-Bicarbonato/metabolismo , Sódio/metabolismo , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico/farmacologia , Animais , Líquido Cefalorraquidiano/metabolismo , Plexo Corióideo/citologia , Plexo Corióideo/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Transporte de Íons , Masculino , Camundongos , Camundongos Endogâmicos
14.
PLoS One ; 13(8): e0202541, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30133510

RESUMO

The mealybug, Phenacoccus manihoti, is a leading pest of cassava (Manihot esculenta Crantz), damaging this crop globally. Although the biological control of this mealybug using natural predators has been established, resistance breeding remains an important means of control. Understanding plant responses to insect herbivory, by determining and identifying differentially expressed genes (DEGs), is a vital step towards the understanding of molecular mechanisms of defence responses in plants and the development of resistant cultivars by gene editing. Morphological and molecular analysis confirmed the mealybug identity as Phenacoccus manihoti (Matile-Ferrero). The transcriptome response of the green mite resistant cassava genotype AR23.1 was compared to P40/1 with no known resistance at 24 and 72 hours of mealybug infestation compared to non-infested mock. A total of 301 and 206 genes were differentially expressed at 24 and 72 of mealybug infestation for AR23.1 and P40/1 genotypes respectively, using a log2 fold change and P-value ≤ 0.05. Gene ontology functional classification revealed an enrichment of genes in the secondary metabolic process category in AR23.1 in comparison with P40/1, while genes in the regulation of molecular function, cellular component biogenesis and electron carrier categories were more significantly enriched in P40/1 than in AR23.1. Biological pathway analysis, based on KEGG, revealed a significant enrichment of plant-pathogen interaction and plant hormonal signal transduction pathways for a cohort of up-regulated and down-regulated DEGs in both genotypes. Defence-related genes such as 2-oxogluterate, gibberellin oxidase and terpene synthase proteins were only induced in genotype AR23.1 and not in P40/1, and subsequently validated by RT-qPCR. The study revealed a difference in response to mealybug infestation in the two genotypes studied, with AR23.1 showing a higher number of differentially expressed transcripts post mealybug infestation at 24 and 72 hours. Candidate defence-related genes that were overexpressed in the AR23.1 genotype post mealybug infestation will be useful in future functional studies towards the control of mealybugs.


Assuntos
Resistência à Doença/genética , Manihot/genética , Controle Biológico de Vetores , Transcriptoma/genética , Animais , Regulação da Expressão Gênica de Plantas/genética , Genótipo , Hemípteros/patogenicidade , Manihot/crescimento & desenvolvimento , Manihot/parasitologia , Melhoramento Vegetal , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Transdução de Sinais/genética
15.
Cerebrospinal Fluid Res ; 4: 8, 2007 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-17883837

RESUMO

Knowledge of the diversity of ion channel form and function has increased enormously over the last 25 years. The initial impetus in channel discovery came with the introduction of the patch clamp method in 1981. Functional data from patch clamp experiments have subsequently been augmented by molecular studies which have determined channel structures. Thus the introduction of patch clamp methods to study ion channel expression in the choroid plexus represents an important step forward in our knowledge understanding of the process of CSF secretion.Two K+ conductances have been identified in the choroid plexus: Kv1 channel subunits mediate outward currents at depolarising potentials; Kir 7.1 carries an inward-rectifying conductance at hyperpolarising potentials. Both K+ channels are localised at the apical membrane where they may contribute to maintenance of the membrane potential while allowing the recycling of K+ pumped in by Na+-K+ ATPase. Two anion conductances have been identified in choroid plexus. Both have significant HCO3- permeability, and may play a role in CSF secretion. One conductance exhibits inward-rectification and is regulated by cyclic AMP. The other is carried by an outward-rectifying channel, which is activated by increases in cell volume. The molecular identity of the anion channels is not known, nor is it clear whether they are expressed in the apical or basolateral membrane. Recent molecular evidence indicates that choroid plexus also expresses the non-selective cation channels such as transient receptor potential channels (TRPV4 and TRPM3) and purinoceptor type 2 (P2X) receptor operated channels. In conclusion, good progress has been made in identifying the channels expressed in the choroid plexus, but determining the precise roles of these channels in CSF secretion remains a challenge for the future.

16.
J Gastrointest Surg ; 11(8): 1008-15, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17623267

RESUMO

Severe acute pancreatitis is characterized by pancreatic necrosis, resulting in local and systemic inflammation. Hyperbaric oxygen (HBO) therapy modulates inflammation, but has not been extensively studied in pancreatitis. This study investigates the effects of HBO in a rat model of severe acute pancreatitis. Sixty-four rats were induced with severe pancreatitis using 4% sodium taurocholate and randomized to HBO treatment or control. HBO was commenced 6 h after induction (100% oxygen at 2.5 atmospheres for 90 min) and continued every 12 h for a maximum of eight treatment episodes. Surviving animals were killed at 7 days. Severity of pancreatitis was graded macroscopically and microscopically. Lung edema was calculated using wet and dry lung weights. Macroscopic and microscopic severity scores (mean +/- SE) of HBO-treated animals with pancreatitis (8.3 +/- 0.7; 9.6 +/- 0.4) were lower than those of controls (10.5 +/- 0.5; 11.1 +/- 0.4) (p = 0.02 and p = 0.03, respectively). The HBO-treated group had reduced pancreatic necrosis compared to controls (40 +/- 4% vs. 54 +/- 4%; p = 0.003). There was no difference in pulmonary edema between the groups. Median survival in the HBO-treatment group was 51 h, compared to 26 h in controls. Day-7 survival was significantly improved in the HBO-treated animals compared to controls (40% vs. 27%; p = 0.04). HBO therapy reduces overall severity, decreases the extent of necrosis, and improves survival in severe acute pancreatitis.


Assuntos
Oxigenoterapia Hiperbárica , Pancreatite/mortalidade , Pancreatite/terapia , Doença Aguda , Animais , Masculino , Ratos , Ratos Wistar , Índice de Gravidade de Doença , Taxa de Sobrevida
17.
J Drug Target ; 15(7-8): 487-95, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17671895

RESUMO

Tetrahydropyranyladriamycin (THP or pirarubicin) destroys tumors via several mechanisms; one of which involves the production of ROS that requires molecular oxygen for its generation. SMA forms stable self-assembled associated micelles with pirarubicin (SMA-pirarubicin), and confers macromolecular characteristics to pirarubicin. This micellar macromolecular drug is selectively delivered to solid tumors via the EPR effect and its preferential tumor accumulation suppresses the systemic toxicity whilst its prolonged high concentration at the site of tumor enhances its efficacy much higher compared to free pirarubicin. Administration of SMA-pirarubicin micelle under HBO can further enhance the delivery of molecular oxygen that facilitates tumor selective generation of ROS, thus augmenting its antitumor potency. In this study, we evaluated the efficacy of SMA-pirarubicin micelles either as single drug or in combination with HBO in a mouse metastatic colorectal cancer model. At or below the maximum tolerated dose, SMA-pirarubicin remarkably reduced metastatic tumor nodules and it was far more effective than free pirarubicin. The data also suggests a potential benefit of combined therapy of HBO with micellar anthracyclins.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Colorretais/patologia , Doxorrubicina/análogos & derivados , Oxigenoterapia Hiperbárica , Neoplasias Hepáticas/terapia , Animais , Antineoplásicos/efeitos adversos , Terapia Combinada , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Sistemas de Liberação de Medicamentos , Neoplasias Hepáticas/secundário , Masculino , Camundongos , Camundongos Endogâmicos CBA , Micelas , Microscopia Eletrônica de Varredura , Permeabilidade , Espécies Reativas de Oxigênio/metabolismo
18.
Diving Hyperb Med ; 47(3): 191-197, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28868600

RESUMO

INTRODUCTION: When a standard water-seal pleural drain unit (PDU) is used under hyperbaric conditions there are scenarios where excessive negative intrapleural pressure (IPP) and/or fluid reflux can be induced, risking significant morbidity. We developed and tested a pleural vacuum relief (PVR) device which automatically manages these risks, whilst allowing more rapid hyperbaric pressure change rates. METHODS: The custom-made PVR device consists of a one-way pressure relief valve connected in line with a sterile micro filter selected for its specific flow capacity. The PVR device is designed for connection to the patient side sampling port of a PDU system, allowing inflow of ambient air whenever negative pressure is present, creating a small, controlled air leak which prevents excessive negative pressure. The hyperbaric performance of a Pleur-Evac A-6000 intercostal drain was assessed with and without this added device by measuring simulated IPP with an electronic pressure monitor connected at the patient end of the PDU. IPP readings were taken at 10, 15, 20 and 30 cmH2O of suction (set on the drain unit) at compression rates of 10, 30, 60, 80, 90 and 180 kPa·min⁻¹ to a pressure of 280 kPa. RESULTS: At any compression rate of > 10 kPa·min⁻¹, the negative IPP generated by the Pleur-Evac A-6000 alone was excessive and resulted in back flow through the PDU water seal. By adding the PVR device, the generated negative IPP remains within a clinically acceptable range, allowing compression rates of at least 30 kPa·min⁻¹ with suction settings up to -20 cmH2O during all phases of hyperbaric treatment. CONCLUSIONS: The PDU PVR device we have developed works well, minimising attendant workload and automatically avoiding the excessive negative IPPs that can otherwise occur. This device should only be used with suction.


Assuntos
Tubos Torácicos , Drenagem/instrumentação , Desenho de Equipamento , Oxigenoterapia Hiperbárica , Pressão , Sucção/instrumentação , Vácuo
19.
J Eval Clin Pract ; 22(3): 411-20, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26696012

RESUMO

RATIONALE, AIMS AND OBJECTIVES: A useful assessment tool that can support health care professionals in anticipating elderly patients' care needs regarding additional support in managing their own medicines is essential, but currently lacking. Thus, the aim of the study was to assess whether the 13-item Strathclyde Compliance Risk Assessment Tool (SCRAT) is an appropriate instrument for identifying community-dwelling elderly people who may be at risk of medication non-adherence. METHOD: An 8-week survey was performed from October to November 2009. Patients were ≥65 years old, receiving ≥3 medications and were either using multi-compartment compliance aids or receiving social care support, or both. The data were collected in 45 face-to-face structured interviews using the 13-item SCRAT, 5-item Medication Adherence Rating Scale (MARS) and 8-item Modified Morisky Adherence Scale (MMAS) in sheltered housing complexes in Glasgow, Scotland. Interviews were analysed quantitatively using SPSS version 21 software. RESULTS: The SCRAT instrument showed substantial inter-rater reliability (Cohen's kappa of 0.730 for the 13-item scale). There was a significant strong negative correlation between the 13-item SCRAT total risk score and 8-item MMAS (r = -0.654; P = 0.0036), and the 13-item SCRAT total risk score and 5-item MARS (r = -0.481; P = 0.0084). The SCRAT instrument showed satisfactory internal consistency (Cronbach's alpha of 0.853 for the 13-item scale). The area under the receiver operator characteristic curve (AUC ± standard error; 95% confidence interval) showed that the SCRAT had good discriminatory capacity and was able to distinguish between adherent and non-adherent participants on the MARS (0.729 ± 0.17; 0.39, 1.00). The best cut-off (sensitivity, specificity) was <3 (75%, 45%). In the sub-analyses, there was a significant difference in total risk score (3 vs. 2, P = 0.011) between users and non-users of multi-compartment compliance aids. CONCLUSION: The study shows that the 13-item SCRAT has the potential to be used in identifying elderly participants who may have problems managing their own medicines and it may help to determine the level and type of assistance that patients require to manage their medicines.


Assuntos
Adesão à Medicação , Inquéritos e Questionários/normas , Idoso , Idoso de 80 Anos ou mais , Feminino , Necessidades e Demandas de Serviços de Saúde , Humanos , Masculino , Assistência Centrada no Paciente , Medição de Risco
20.
ANZ J Surg ; 75(12): 1059-64, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16398811

RESUMO

BACKGROUND: Management of necrotizing fasciitis places significant demands upon hospital and medical resources. A successful management usually requires extensive surgical intervention and an adjunct hyperbaric oxygen treatment. The cost impact on the health care system has not been well characterized. We have, therefore, analysed the cost of treating this disease at an Australian tertiary referral hospital with extensive case experience and well-developed financial costing systems and have compared this with the current casemix-based government funding arrangements applying in Victoria, Australia. METHODS: Data was extracted from the medical records of 92 sequential patients treated by the Alfred Hospital (Melbourne, Australia) during the four financial years 2000-04. Clinical costing data and government funding data was provided by the hospital's Finance Departments. RESULTS: The total Alfred Hospital in-patient costs for treating the patients was $5,935,545 with a mean cost per patient of $64,517 (range, $1025 to $514,889). The total casemix-based funding allocation derived from treating these patients was calculated at $3,208,664 with the per patient mean $34,887 (range, $1331 to $387,168). This analysis does not include allowance for non-Alfred Hospital costs such as those incurred by the ambulance service, referring hospitals, for rehabilitation or as a result of the burden of residual disability. CONCLUSIONS: This study has confirmed that a significant economic burden is involved in treating necrotizing fasciitis. There is a substantial difference between the hospital costs and government funding for treating these patients in the Australian setting.


Assuntos
Fasciite Necrosante/economia , Custos Hospitalares , Grupos Diagnósticos Relacionados , Fasciite Necrosante/complicações , Fasciite Necrosante/epidemiologia , Fasciite Necrosante/terapia , Feminino , Humanos , Oxigenoterapia Hiperbárica , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Vitória
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