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1.
Front Digit Health ; 5: 1066327, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36937251

RESUMO

Background: There is limited literature on security and access for social care settings despite policy highlighting importance, and no published research exploring facial recognition lock technology (FRLT) for potential improvements. This study explored FRLT device implementation, use, barriers and benefits. Methods: One residential care home with 43 older adults and 68 staff members (Site A), and one supported living facility caring for six individuals with mental health issues with 18 staff members (Site B) were provided with FRLT for six months. Nine pre-implementation staff interviews explored existing access and security perceptions. Ten post-implementation staff interviews and one staff focus group were conducted; all were analysed using content analysis to understand, alongside process mapping, the use and impact of the FRLT. Interview participants included site care staff and other visiting healthcare professionals. We additionally report feedback from the technology developers to demonstrate impact of industry-academia collaboration. Results: Pre-implementation interviews highlighted issues with current pin-pad or lock-box systems, including; code sharing; code visibility, ineffective code changes, security issues following high staff turnover, lack of efficiency for visitors including NHS staff and lack of infection control suggesting requirement for innovation and improvement. Pre-implementation interviews showed openness and interest in FRLT, although initial queries were raised around cost effectiveness and staff skills. Following implementation, good levels of adoption were achieved with 72% and 100% (49/68 and 18/18) of staff members uploading their face at the two sites, and 100% of residents at Site B using the system (6/6). Additionally, Site B made a positive procurement decision and continues to discuss wider rollout. Post implementation interviews suggested FRLT was useful and acceptable for improving security and access. Benefits identified included staff/visitor time saving, enhanced security, team ease of access, resident autonomy and fewer shared touch points. Integration was suggested including with fire alarm systems, staff clocking in/out, and Covid monitoring to improve usefulness. The developers have since responded to feedback with design iterations. Conclusion: We identified concerns on security and access in social care settings, which warrant further exploration and research. FRLT could increase resident autonomy and reduce staff burden, particularly considering frequent multi-agency health and care visits.

2.
Nat Food ; 1(8): 468-474, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37128071

RESUMO

Aquaculture is predicted to supply the majority of aquatic dietary protein by 2050. For aquaculture to deliver significantly enhanced volumes of food in a sustainable manner, appropriate account needs to be taken of its impacts on environmental integrity, farmed organism health and welfare, and human health. Here, we explore increased aquaculture production through the One Health lens and define a set of success metrics - underpinned by evidence, policy and legislation - that must be embedded into aquaculture sustainability. We provide a framework for defining, monitoring and averting potential negative impacts of enhanced production - and consider interactions with land-based food systems. These metrics will inform national and international science and policy strategies to support improved aquatic food system design.

3.
Oxf Med Case Reports ; 2016(10): omw073, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27699052

RESUMO

We report the case of a 40-year-old female transplant patient with undiagnosed ANCA-associated vasculitis (AAV) and renal allograft dysfunction who achieved disease remission with restoration of transplant function following induction therapy with rituximab. There are currently no trial data looking at the use of rituximab for induction of remission of renal transplant patients with AAV. Although recurrence of AAV following renal transplantation is rare, such patients have invariably had multiple previous exposures to induction and maintenance immunosuppressive regimens, often limiting treatment options post-transplantation. In this case, rituximab was well tolerated with no side effects, and was successful in salvaging transplant function. Optimal treatment regimens for relapsed AAV in the transplant population are not known, and clinical trials are needed to evaluate the efficacy and safety of rituximab at inducing and maintaining disease remission in relapsed AAV following transplantation.

4.
Int J Hyg Environ Health ; 216(3): 346-54, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22898546

RESUMO

From May to July 2011, one of the largest reported outbreaks of haemolytic uraemic syndrome (HUS) and bloody diarrhoea caused by the Shiga toxin-producing Escherichia coli (STEC) O104:H4 occurred in Germany and France. The hypothetical origin of the outbreak strain was a combined enteroaggregative E. coli and an enterohaemorrhagic E. coli with the ability to resist multi-antibiotics and produce Shiga-toxin 2. The combination of aggregative ability, antibiotic resistance and the production of Shiga-toxin 2 significantly affected the severity of the symptoms presented. Since humans may be the primary reservoir, it is likely that contamination could have occurred through contact with infected individuals. Farm food safety management, and hand hygiene training programmes are crucial to primary production to prevent or reduce risks of contamination.


Assuntos
Surtos de Doenças , Infecções por Escherichia coli/epidemiologia , Síndrome Hemolítico-Urêmica/epidemiologia , Escherichia coli Shiga Toxigênica , Infecções por Escherichia coli/transmissão , Inocuidade dos Alimentos , Alemanha/epidemiologia , Humanos , Higiene , Plântula/microbiologia
5.
Food Chem ; 136(3-4): 1603-9, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23194569

RESUMO

The objective of this study was to develop a farm food safety-risk assessment tool (FRAMp) which serves as a self-assessment and educational tool for fresh produce farms. FRAMp was developed in Microsoft® Excel spreadsheet software using standard mathematical and logical functions and utilised a qualitative risk assessment approach for farmers to evaluate their food safety practices. The FRAMp tool has since been tested on 12 fresh produce farms throughout UK. All the farms determined that FRAMp was interesting but 17% found it too long while 25% of the farms felt the tool was too complicated. The instructions on FRAMp usage were revised and farmers were given the options to skip and select specific steps in the farm risk assessment. The end users (farmers/farm managers) determined that developing their own action plans and using it as proof of assessment for future third-party audits were most useful to them. FRAMp tool can be described as an illustrative risk ranking tool to facilitate farms to identify potential risk factors during their crop production.


Assuntos
Agricultura/normas , Inocuidade dos Alimentos , Medição de Risco/métodos , Humanos , Software , Reino Unido , Recursos Humanos
6.
Anim Health Res Rev ; 12(2): 197-211, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22152293

RESUMO

This paper addresses food safety in beef cattle production, with particular emphasis on factors that affect the prevalence of Escherichia coli O157:H7 in beef cattle and on control methods that have been investigated. Product recalls and foodborne diseases due to this organism continue to occur even though control measures have been under investigation for over 20 years. Most meatborne outbreaks are due to improper food handling practices and consumption of undercooked meat. However, the majority of pathogenic bacteria that can spread at slaughter by cross-contamination can be traced back to the farm rather than originating from the slaughter plant. This would ideally require the adoption of rigorous on-farm intervention strategies to mitigate risks at the farm level. On-farm strategies to control and reduce E. coli O157:H7 at the farm level will reduce the risk of carcass contamination at slaughter and processing facilities although they will not eliminate E. coli O157:H7. The most successful strategy for reducing the risk of contamination of beef and beef products will involve the implementation of both pre- and post-harvest measures.


Assuntos
Doenças dos Bovinos/prevenção & controle , Infecções por Escherichia coli/veterinária , Escherichia coli O157/isolamento & purificação , Microbiologia de Alimentos , Carne , Matadouros , Animais , Bovinos , Qualidade de Produtos para o Consumidor , Reservatórios de Doenças/veterinária , Infecções por Escherichia coli/prevenção & controle
8.
J Child Psychol Psychiatry ; 43(8): 1075-86, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12455928

RESUMO

BACKGROUND: An investigation of intergenerational factors associated with psychiatric disorder in late adolescence/early adulthood was undertaken to differentiate influences from maternal disorder, maternal poor psychosocial functioning and poor parenting, on offspring. METHOD: The sample comprised an intensively studied series of 276 mother-offspring pairs in a relatively deprived inner-city London area with high rates of lone parenthood and socio-economic disadvantage. The paired sample was collected over two time periods: first a consecutively screened series of mothers and offspring in 1985-90 (n = 172 pairs) and second a 'vulnerable' series of mothers and offspring in 1995-99 (n = 104 pairs). The vulnerable mothers were selected for poor interpersonal functioning and/or low self-esteem and the consecutive series were used for comparison. Rates of childhood adversity and disorder in the offspring were examined in the two groups. Maternal characteristics including psychosocial vulnerability and depression were then examined in relation to risk transmission. RESULTS: Offspring of vulnerable mothers had a fourfold higher rate of yearly disorder than those in the comparison series (43% vs. 11%, p < .001). They were twice as likely as those in the comparison series to have experienced childhood adversity comprising either severe neglect, physical or sexual abuse before age 17. Physical abuse, in particular, perpetrated either by mother or father/surrogate father was significantly raised in the vulnerable group. Analysis of the combined series showed that maternal vulnerability and neglect/abuse of offspring provided the best model for offspring disorder. Maternal history of depression had no direct effect on offspring disorder; its effects were entirely mediated by offspring neglect/abuse. Maternal childhood adversity also had no direct effect. CONCLUSIONS: Results are discussed in relation to psychosocial models of risk transmission for disorder. Maternal poor psychosocial functioning needs to be identified as a factor requiring intervention in order to stem escalation of risk across generations.


Assuntos
Maus-Tratos Infantis/psicologia , Filho de Pais com Deficiência/psicologia , Relações Mãe-Filho , Transtornos da Personalidade/genética , Adolescente , Adulto , Feminino , Humanos , Londres/epidemiologia , Masculino , Poder Familiar/psicologia , Transtornos da Personalidade/epidemiologia , Fatores de Risco , Apoio Social , População Urbana
9.
Neuron ; 30(1): 149-59, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11343651

RESUMO

The trp (transient receptor potential) gene encodes a Ca2+ channel responsible for the major component of the phospholipase C (PLC) mediated light response in Drosophila. In trp mutants, maintained light leads to response decay and temporary total loss of sensitivity (inactivation). Using genetically targeted PIP2-sensitive inward rectifier channels (Kir2.1) as biosensors, we provide evidence that trp decay reflects depletion of PIP2. Two independent mutations in the PIP2 recycling pathway (rdgB and cds) prevented recovery from inactivation. Abolishing Ca2+ influx in wild-type photoreceptors mimicked inactivation, while raising Ca2+ by blocking Na+/Ca2+ exchange prevented inactivation in trp. The results suggest that Ca2+ influx prevents PIP2 depletion by inhibiting PLC activity and facilitating PIP2 recycling. Without this feedback one photon appears sufficient to deplete the phosphoinositide pool of approximately 4 microvilli.


Assuntos
Canais de Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Cálcio/deficiência , Proteínas de Drosophila , Drosophila melanogaster/metabolismo , Proteínas de Insetos/metabolismo , Fosfatidilinositol 4,5-Difosfato/metabolismo , Células Fotorreceptoras de Invertebrados/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização , Visão Ocular/fisiologia , Animais , Técnicas Biossensoriais , Meios de Cultura , Drosophila melanogaster/citologia , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Mutação/fisiologia , Fenótipo , Células Fotorreceptoras de Invertebrados/citologia , Células Fotorreceptoras de Invertebrados/efeitos dos fármacos , Canais de Potássio/metabolismo , Canais de Potencial de Receptor Transitório , Visão Ocular/efeitos dos fármacos
10.
J Neurosci ; 21(5): 1523-31, 2001 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11222642

RESUMO

We examine the role of synaptic activity in the development of identified Drosophila embryonic motorneurons. Synaptic activity was blocked by both pan-neuronal expression of tetanus toxin light chain (TeTxLC) and by reduction of acetylcholine (ACh) using a temperature-sensitive allele of choline acetyltransferase (Cha(ts2)). In the absence of synaptic activity, aCC and RP2 motorneurons develop with an apparently normal morphology and retain their capacity to form synapses. However, blockade of synaptic transmission results in significant changes in the electrical phenotype of these neurons. Specifically, increases are seen in both voltage-gated inward Na(+) and voltage-gated outward K(+) currents. Voltage-gated Ca(2+) currents do not change. The changes in conductances appear to promote neuron excitability. In the absence of synaptic activity, the number of action potentials fired by a depolarizing ramp (-60 to +60 mV) is increased and, in addition, the amplitude of the initial action potential fired is also significantly larger. Silencing synaptic input to just aCC, without affecting inputs to other neurons, demonstrates that the capability to respond to changing levels of synaptic excitation is intrinsic to these neurons. The alteration to electrical properties are not permanent, being reversed by restoration of normal synaptic function. Whereas our data suggest that synaptic activity makes little or no contribution to the initial formation of embryonic neural circuits, the electrical development of neurons that constitute these circuits seems to depend on a process that requires synaptic activity.


Assuntos
Neurônios Motores/fisiologia , Transmissão Sináptica/fisiologia , Acetilcolina/deficiência , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Canais de Cálcio/metabolismo , Colina O-Acetiltransferase/genética , Colina O-Acetiltransferase/metabolismo , Drosophila , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Técnicas In Vitro , Metaloendopeptidases/biossíntese , Metaloendopeptidases/genética , Metaloendopeptidases/farmacologia , Neurônios Motores/citologia , Neurônios Motores/efeitos dos fármacos , Técnicas de Patch-Clamp , Canais de Potássio/metabolismo , Canais de Sódio/metabolismo , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Transmissão Sináptica/efeitos dos fármacos , Temperatura , Toxina Tetânica/biossíntese , Toxina Tetânica/genética , Toxina Tetânica/farmacologia
11.
Br J Perioper Nurs ; 11(1): 34-9, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11892113

RESUMO

Discrete item purchasing is the traditional approach for hospitals to obtain consumable supplies for theatre procedures. Although most items are relatively low cost, the management and co-ordination of the supply chain, raising orders, controlling stock, picking and delivering to each operating theatre can be complex and costly. Customized procedure packs provide a solution.


Assuntos
Procedimentos Neurocirúrgicos/instrumentação , Enfermagem Perioperatória , Equipamentos Cirúrgicos , Análise Custo-Benefício , Equipamentos Descartáveis , Humanos , Serviço Hospitalar de Compras , Equipamentos Cirúrgicos/economia , Reino Unido
12.
Curr Biol ; 9(21): 1267-70, 1999 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-10556094

RESUMO

During the development of the nervous system embryonic neurons are incorporated into neural networks that underlie behaviour. For example, during embryogenesis in Drosophila, motor neurons in every body segment are wired into the circuitry that drives the simple peristaltic locomotion of the larva. Very little is known about the way in which the necessary central synapses are formed in such a network or how their properties are controlled. One possibility is that presynaptic and postsynaptic elements form relatively independently of each other. Alternatively, there might be an interaction between presynaptic and postsynaptic neurons that allows for adjustment and plasticity in the embryonic network. Here we have addressed this issue by analysing the role of synaptic transmission in the formation of synaptic inputs onto identified motorneurons as the locomotor circuitry is assembled in the Drosophila embryo. We targeted the expression of tetanus toxin light chain (TeTxLC) to single identified neurons using the GAL4 system. TeTxLC prevents the evoked release of neurotransmitter by enzymatically cleaving the synaptic-vesicle-associated protein neuronal-Synaptobrevin (n-Syb) [1]. Unexpectedly, we found that the cells that expressed TeTxLC, which were themselves incapable of evoked release, showed a dramatic reduction in synaptic input. We detected this reduction both electrophysiologically and ultrastructurally.


Assuntos
Drosophila/fisiologia , Sinapses/fisiologia , Transmissão Sináptica/fisiologia , Toxina Tetânica/farmacologia , Animais , Rede Nervosa , Sinapses/ultraestrutura , Toxina Tetânica/genética
13.
Dev Genet ; 24(1-2): 57-68, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10079511

RESUMO

Recent experiments have demonstrated that a family of proteins, known as the innexins, are structural components of invertebrate gap junctions. The shaking-B (shak-B) locus of Drosophila encodes two members of this emerging family, Shak-B(lethal) and Shak-B(neural). This study focuses on the role of Shak-B gap junctions in the development of embryonic and larval muscle. During embryogenesis, shak-B transcripts are expressed in a subset of the somatic muscles; expression is strong in ventral oblique muscles (VO4-6) but only weak in ventral longitudinals (VL3 and 4). Carboxyfluorescein injected into VO4 of wild-type early stage 16 embryos spreads, via gap junctions, to label adjacent muscles, including VL3 and 4. In shak-B2 embryos (in which the shak-B(neural) function is disrupted), dye injected into VO4 fails to spread into other muscles. In the first instar larva, when dye coupling between muscles is no longer present, another effect of the shak-B2 mutation is revealed by whole-cell voltage clamp. In a calcium-free saline, only two voltage-activated potassium currents are present in wild-type muscles; a fast IA and a slow IK current. In shak-B2 larvae, these two currents are significantly reduced in magnitude in VO4 and 5, but remain normal in VL3. Expression of shak-B(neural) in a shak-B2 background fully rescues both dye coupling in embryonic muscle and whole-cell currents in first instar VO4 and 5. Our observations show that Shak-B(neural) is one of a set of embryonic gap-junction proteins, and that it is required for the normal temporal development of potassium currents in some larval muscles.


Assuntos
Conexinas/fisiologia , Proteínas de Drosophila , Drosophila/crescimento & desenvolvimento , Junções Comunicantes/fisiologia , Desenvolvimento Muscular , Proteínas do Tecido Nervoso/fisiologia , Animais , Comunicação Celular , Conexinas/genética , Drosophila/embriologia , Drosophila/genética , Condutividade Elétrica , Fluoresceínas/metabolismo , Corantes Fluorescentes/metabolismo , Expressão Gênica , Músculos/embriologia , Músculos/fisiologia , Músculos/ultraestrutura , Proteínas do Tecido Nervoso/genética , Técnicas de Patch-Clamp , Potássio/metabolismo
15.
J Neurosci ; 18(12): 4673-83, 1998 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-9614242

RESUMO

In this study, we describe the development of electrical properties of Drosophila embryonic central neurons in vivo. Using whole-cell voltage clamp, we describe the onset of expression of specific voltage- and ligand-gated ionic currents and the first appearance of endogenous and synaptic activity. The first currents occur during midembryogenesis [late stage 16, 13-14 hr after egg laying (AEL)] and consist of a delayed outward potassium current (IK) and an acetylcholine-gated inward cation current (IACh). As development proceeds, other voltage-activated currents arise sequentially. An inward calcium current (ICa) is first observed at 15 hr AEL, an inward sodium current (INa) at 16 hr AEL, and a rapidly inactivating outward potassium current (IA) at 17 hr AEL. The inward calcium current is composed of at least two individual and separable components that exhibit small temporal differences in their development. Endogenous activity is first apparent at 15 hr AEL and consists of small events (peak amplitude, 5 pA) that probably result from the random opening of relatively few numbers of ion channels. At 16 hr AEL, discrete (10-15 msec duration) currents that exhibit larger amplitude (25 pA maximum) and rapid activation but slower inactivation first appear. We identify these latter currents as EPSCs, an indication that functional synaptic transmission is occurring. In the neurons from which we record, action potentials first occur at 17 hr AEL. This study is the first to record from Drosophila embryonic central neurons in vivo and makes possible future work to define the factors that shape the electrical properties of neurons during development.


Assuntos
Sistema Nervoso Central/embriologia , Drosophila/embriologia , Neurônios/fisiologia , Animais , Cálcio/fisiologia , Sistema Nervoso Central/citologia , Condutividade Elétrica , Eletrofisiologia , Embrião não Mamífero/citologia , Embrião não Mamífero/fisiologia , Neurônios/metabolismo , Potássio/fisiologia , Receptores Colinérgicos/metabolismo , Sódio/fisiologia , Sinapses/fisiologia
16.
Nature ; 391(6663): 181-4, 1998 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-9428764

RESUMO

In most multicellular organisms direct cell-cell communication is mediated by the intercellular channels of gap junctions. These channels allow the exchange of ions and molecules that are believed to be essential for cell signalling during development and in some differentiated tissues. Proteins called connexins, which are products of a multigene family, are the structural components of vertebrate gap junctions. Surprisingly, molecular homologues of the connexins have not been described in any invertebrate. A separate gene family, which includes the Drosophila genes shaking-B and l(1)ogre, and the Caenorhabditis elegans genes unc-7 and eat-5, encodes transmembrane proteins with a predicted structure similar to that of the connexins. shaking-B and eat-5 are required for the formation of functional gap junctions. To test directly whether Shaking-B is a channel protein, we expressed it in paired Xenopus oocytes. Here we show that Shaking-B localizes to the membrane, and that its presence induces the formation of functional intercellular channels. To our knowledge, this is the first structural component of an invertebrate gap junction to be characterized.


Assuntos
Conexinas/fisiologia , Proteínas de Drosophila , Drosophila/fisiologia , Junções Comunicantes/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Animais , Membrana Celular/fisiologia , Clonagem Molecular , Conexinas/genética , Drosophila/citologia , Eletrofisiologia , Proteínas do Tecido Nervoso/genética , Oócitos , Técnicas de Patch-Clamp , Proteínas Recombinantes , Transfecção , Xenopus
18.
Hypertension ; 28(5): 772-8, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8901822

RESUMO

Vascular smooth muscle cells of the spontaneously hypertensive rat (SHR) are known to show increased responsiveness to angiotensin II (Ang II) compared with cells of normotensive control Wistar-Kyoto rats (WKY). We investigated the hypothesis that differential levels of cGMP lead to the different responsiveness of the cells, using vascular smooth muscle cells in culture. cGMP levels in extracts of SHR-derived cells were lower than those of WKY-derived cells. This was true for both unstimulated cells and cells treated with equal concentrations of either sodium nitroprusside or S-nitroso-N-acetylpenicillamine. Stimulation of cells with Ang II did not affect levels of cGMP but increased levels of inositol 1, 4, 5-trisphosphate (IP3) and Ca2+, which were greater in SHR- than in WKY-derived cells. When SHR and WKY cells were preincubated with different concentrations of S-nitroso-N-acetylpenicillamine to generate similar cGMP levels in each cell type, the subsequent IP3 response to Ang II was the same in the two cell types. To reduce any influence of cGMP on responses, we permeabilized the cells with alpha-toxin. Stimulation of alpha-toxin-permeabilized the cells with high Ca2+ revealed an IP3 response in SHR- but not WKY-derived cells. Similarly, permeabilized SHR cells responded to Ang II but WKY cells did not. However, GTP and GTP gamma S elevated IP3 in both cell types. Taken together, these results indicate that the low response of WKY cells can be accounted for by the inhibitory influence of cGMP. However, when this inhibition is removed by permeabilization, further differences between the cells are revealed that will contribute to the elevated SHR response.


Assuntos
Angiotensina II/farmacologia , GMP Cíclico/fisiologia , Inositol 1,4,5-Trifosfato/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Fosfolipases Tipo C/efeitos dos fármacos , Animais , Cálcio/metabolismo , Células Cultivadas , Interações Medicamentosas , Penicilamina/análogos & derivados , Penicilamina/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , S-Nitroso-N-Acetilpenicilamina , Especificidade da Espécie , Fosfolipases Tipo C/metabolismo , Vasodilatadores/farmacologia
19.
J Neurophysiol ; 75(6): 2647-50, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8793768

RESUMO

1. The neuropeptide proctolin (Arg-Tyr-Leu-Pro-Thr) both potentiates neurally evoked contractions and causes contractures of insect skeletal muscle. In the hindleg extensor tibiae muscle of the locust, Schistocerca gregaria, the proctolin analogue [Afb (p-NO2)2]-proctolin is also able to potentiate neurally evoked contractions but is approximately 1,000-fold less effective in evoking contractures. 2. Proctolin and [Afb (p-NO2)2]-proctolin are equipotent in their ability to elevate the second-messenger inositol trisphosphate in isolated extensor tibiae muscle fiber membranes. 3. [Afb (p-NO2)2]-proctolin is approximately 1,000-fold less effective than proctolin in reducing the resting potassium conductance (GK) in extensor tibiae fibers. 4. We conclude that the action of proctolin on the extensor tibiae muscle is mediated by at least two receptor subtypes and that [Afb (p-NO2)2]-proctolin acts selectively on the receptor that potentiates neurally evoked contractions.


Assuntos
Gafanhotos/fisiologia , Neuropeptídeos , Neurotransmissores/farmacologia , Oligopeptídeos/farmacologia , Receptores de Neuropeptídeos/efeitos dos fármacos , Animais , Extremidades/inervação , Extremidades/fisiologia , Feminino , Gânglios dos Invertebrados/citologia , Gânglios dos Invertebrados/efeitos dos fármacos , Gânglios dos Invertebrados/fisiologia , Técnicas In Vitro , Inosina Trifosfato/metabolismo , Masculino , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Músculos/inervação , Músculos/metabolismo , Músculos/fisiologia , Técnicas de Patch-Clamp , Canais de Potássio/efeitos dos fármacos , Canais de Potássio/metabolismo , Receptores de Neuropeptídeos/metabolismo
20.
J Exp Biol ; 199(Pt 9): 1973-82, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9319882

RESUMO

The pair of vasopressin-like immunoreactive (VPLI) neurones of the locust Locusta migratoria have cell bodies in the suboesophageal ganglion and extensive arborization throughout the central nervous sytem. The activity of the VPLI neurone is regulated by a spontaneously active excitatory descending interneurone (DI) that is, in turn, inhibited by an uncharacterised extraocular photoreceptor (EOP) system located in the brain. Light directed at the brain results in inhibition of DI activity, which thereby deprives the VPLI neurone of its major synaptic input. We present evidence that histamine plays an important role in the EOP­DI­VPLI pathway. Histamine mimics the EOP-mediated inhibition of the DI, and the H2-specific histamine antagonists cimetidine and ranitidine block its inhibitory action. Histamine application to various areas of the brain localises the area where histaminergic inhibition occurs; this region is confined to the medial protocerebrum. At least six bilaterally paired histamine-like immunoreactive neurones send axonal projections into this area. Depolarisation of the brain region containing the soma of these neurones with high-K+ saline deactivates the VPLI neurone through the removal of the DI excitatory synaptic input.

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