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1.
J Occup Environ Hyg ; 19(8): 455-468, 2022 08.
Article in English | MEDLINE | ID: mdl-35687041

ABSTRACT

The list of EPA-approved disinfectants for coronavirus features many products for use on hard, non-porous materials. There are significantly fewer products registered for use on porous materials. Further, many common, high-touch surfaces fall in between non-porous materials such as glass and porous materials such as soft fabrics. The objective of this study was to assess the efficacy of selected commercially available disinfectant products against coronaviruses on common, high-touch surfaces. Four disinfectants (Clorox Total 360, Bleach solution, Vital Oxide, and Peroxide Multi-Surface Cleaner) were evaluated against Murine Hepatitis Virus A59 (MHV) as a surrogate coronavirus for SARS-CoV-2. MHV in cell culture medium was inoculated onto four materials: stainless steel, latex-painted drywall tape, Styrene Butadiene rubber (rubber), and bus seat fabric. Immediately (T0) or 2-hr (T2) post-inoculation, disinfectants were applied by trigger-pull or electrostatic sprayer and either held for recommended contact times (Spray only) or immediately wiped (Spray and Wipe). Recovered infectious MHV was quantified by median tissue culture infectious dose assay. Bleach solution, Clorox Total 360, and Vital Oxide were all effective (>3-log10 reduction or complete kill of infectious virus) with both the Spray Only and Spray and Wipe methods on stainless steel, rubber, and painted drywall tape when used at recommended contact times at both T0 and T2 hr. Multi-Surface Cleaner unexpectedly showed limited efficacy against MHV on stainless steel within the recommended contact time; however, it showed increased (2.3 times greater efficacy) when used in the Spray and Wipe method compared to Spray Only. The only products to achieve a 3-log10 reduction on fabric were Vital Oxide and Clorox Total 360; however, the efficacy of Vital Oxide against MHV on fabric was reduced to below 3-log10 when applied by an electrostatic sprayer compared to a trigger-pull sprayer. This study highlights the importance of considering the material, product, and application method when developing a disinfection strategy for coronaviruses on high-touch surfaces.


Subject(s)
COVID-19 , Disinfectants , Murine hepatitis virus , Animals , Disinfectants/pharmacology , Disinfection/methods , Mice , Rubber/pharmacology , SARS-CoV-2 , Sodium Hypochlorite/pharmacology , Stainless Steel/pharmacology
2.
JDR Clin Trans Res ; 7(2): 118-126, 2022 04.
Article in English | MEDLINE | ID: mdl-33955299

ABSTRACT

INTRODUCTION: There has been little research to explore how adults financially value private orthodontic treatment and whether they have preferences for different attributes of treatment. This study used a discrete choice experiment and aimed to determine whether the recognized skill level of the dental professional and the type of orthodontic appliance influence the values that the public places on private adult orthodontic treatment. METHODS: In total, 206 adult patients or the parents/guardians of children attending general dental practices in the northeast of England were recruited to complete a discrete choice experiment. Three attributes were included: the type of dental professional providing treatment, the type of orthodontic appliance, and cost. Also collected were demographic and orthodontic history characteristics. Results were analyzed with conditional logistic regression and elicited marginal willingness to pay (MWTP). RESULTS: Participants value the training and expertise of the dental professional providing private orthodontic treatment greater than the type of orthodontic appliance. MWTP for orthodontic treatment increased in conjunction with the recognized skill level of the dental professional. Participants were willing to pay more for aesthetic appliances over a fixed metal appliance. CONCLUSIONS: Participants value the training and expertise of the dental professional providing private adult orthodontic treatment greater than the type of orthodontic appliance. These preferences concur with other discrete choice experiments undertaken in medical specialties that included attributes focusing on the qualification, skill, or expertise of the health care professional. MWTP for orthodontic treatment increased in conjunction with the recognized skill level of the dental professional. Participants were willing to pay more for aesthetic appliances than metal fixed appliances. The cost of orthodontics is significant, and adults appreciate the importance of having options and making choices.Knowledge Transfer Statement: The results of this study suggest that patients are willing to pay more for orthodontic services provided by clinicians with higher levels of formal training. In a competitive market where the public appears to prefer the provider over treatment modality, there is an incentive for clinicians to optimize their knowledge and skills to deliver the high-quality orthodontic treatment that patients are demanding. Orthodontic clinicians should be mindful of the demand for the different adult orthodontic appliances and tailor their skill sets accordingly.


Subject(s)
Esthetics, Dental , Orthodontics , Adult , Child , Dental Care , Health Personnel , Humans , Orthodontic Appliances
3.
Br J Dermatol ; 180(6): 1390-1396, 2019 06.
Article in English | MEDLINE | ID: mdl-30580464

ABSTRACT

BACKGROUND: There is a need for greater understanding of the spectrum of emotional and behavioural reactions that individuals in the general population may experience in response to genomic testing for melanoma risk. OBJECTIVES: To explore how individuals in the general population respond to receiving personalized genomic risk of melanoma. METHODS: Semistructured interviews were undertaken with 30 participants (aged 24-69 years, 50% female, 12 low risk, eight average risk, 10 high risk) recruited from a pilot trial in which they received personalized melanoma genomic risk information. We explored participants' emotional and behavioural responses to receiving their melanoma genomic risk information. The qualitative data were analysed thematically. RESULTS: Many participants reported a positive response to receiving their melanoma genomic risk, including feelings of happiness, reassurance and gaining new knowledge to help manage their melanoma risk. Some participants reported short-term negative emotional reactions that dissipated over time. Most individuals, particularly those who received average or high-risk results, reported making positive behaviour changes to reduce their melanoma risk. Emotional and behavioural responses were linked to participants' expectations for their risk result, their pre-existing perception of their own melanoma risk, their existing melanoma preventive behaviours and their genomic risk category. CONCLUSIONS: Personalized melanoma genomic risk information alongside education and lifestyle counselling is favourably received by people without a personal history and unselected for a family history of melanoma. Participants described increased knowledge and awareness around managing skin cancer risk and improved sun protection and skin examination behaviours. Any initial feelings of distress usually dissipated over time.


Subject(s)
Emotions , Health Behavior , Skin Neoplasms/psychology , Adult , Aged , Genetic Counseling/psychology , Genetic Predisposition to Disease/psychology , Genetic Testing , Health Communication , Humans , Information Dissemination , Male , Melanoma/genetics , Melanoma/psychology , Middle Aged , New South Wales , Patient Education as Topic , Patient Preference , Pilot Projects , Risk Assessment/methods , Skin Neoplasms/genetics , Young Adult
4.
Br Dent J ; 219(12): 561, 2015 Dec 18.
Article in English | MEDLINE | ID: mdl-26679115
5.
Neuroscience ; 265: 204-16, 2014 Apr 18.
Article in English | MEDLINE | ID: mdl-24468105

ABSTRACT

Associative learning is encoded under anesthesia and involves the medial prefrontal cortex (mPFC). Neuronal activity in mPFC increases in response to a conditioned stimulus (CS+) previously paired with an unconditioned stimulus (US) but not during presentation of an unpaired stimulus (CS-) in anesthetized animals. Studies in conscious animals have shown dissociable roles for different mPFC subregions in mediating various memory processes, with the prelimbic (PL) and infralimbic (IL) cortex involved in the retrieval and extinction of conditioned responding, respectively. Therefore PL and IL may also play different roles in mediating the retrieval and extinction of discrimination learning under anesthesia. Here we used in vivo electrophysiology to examine unit and local field potential (LFP) activity in PL and IL before and after auditory discrimination learning and during later retrieval and extinction testing in anesthetized rats. Animals received repeated presentations of two distinct sounds, one of which was paired with footshock (US). In separate control experiments animals received footshocks without sounds. After discrimination learning the paired (CS+) and unpaired (CS-) sounds were repeatedly presented alone. We found increased unit firing and LFP power in PL and, to a lesser extent, IL after discrimination learning but not after footshocks alone. After discrimination learning, unit firing and LFP power increased in PL and IL in response to presentation of the first CS+, compared to the first CS-. However, PL and IL activity increased during the last CS- presentation, such that activity during presentation of the last CS+ and CS- did not differ. These results confirm previous findings and extend them by showing that increased PL and IL activity result from encoding of the CS+/US association rather than US presentation. They also suggest that extinction may occur under anesthesia and might be represented at the neural level in PL and IL.


Subject(s)
Anesthesia , Learning/drug effects , Neurons/drug effects , Prefrontal Cortex/drug effects , Acoustic Stimulation , Animals , Association Learning/drug effects , Association Learning/physiology , Discrimination Learning , Extinction, Psychological/drug effects , Extinction, Psychological/physiology , Learning/physiology , Male , Mental Recall/drug effects , Mental Recall/physiology , Neurons/physiology , Prefrontal Cortex/physiology , Rats
6.
Neuroscience ; 233: 146-56, 2013 Mar 13.
Article in English | MEDLINE | ID: mdl-23295986

ABSTRACT

Associative learning can occur under anesthesia and its neural correlates have begun to be elucidated. During discrimination learning under anesthesia in rats, lateral amygdala excitability increases in response to a conditioned stimulus (CS+) previously paired with electrical stimulation of the paw but not to another stimulus presented alone (CS-). Similarly, medial prefrontal cortex activity increases selectively during CS+ presentation after discrimination learning but this occurs only in neurons receiving input from the basolateral amygdala (BLA), the main source of amygdaloid projections to this region. However, BLA activity during discrimination learning under anesthesia has not been investigated. Here we used in vivo electrophysiology to examine BLA activity before and after associative learning and during later memory retrieval in anesthetized rats. We examined extracellular unit and local field potential (LFP) activity using an auditory discrimination learning paradigm. Rats were repeatedly presented with two distinct sounds, one of which was paired with electrical stimulation of the paw. One hour later, the paired sound (CS+) was presented alone along with the sound not paired with electrical stimulation (CS-). We found increased unit firing late (1 h) but not early (5 min) after learning. LFP power was increased both early and late after learning. In control experiments we also found increased unit and LFP activity late after electrical stimulation alone. After discrimination learning, unit firing increased in response to CS+, but not CS-, presentation. LFP power also showed a modest increase during CS+, compared to CS-, presentation. These findings suggest that discrimination learning under anesthesia can occur at the neural level in BLA. The potential relevance of these results is discussed in relation to previous studies examining neural activity during fear learning and memory processing in conscious animals.


Subject(s)
Amygdala/physiology , Association Learning/physiology , Awareness/physiology , Discrimination Learning/physiology , Recognition, Psychology/physiology , Acoustic Stimulation , Amygdala/drug effects , Anesthesia, General/veterinary , Anesthetics, Inhalation/pharmacology , Animals , Association Learning/drug effects , Awareness/drug effects , Conditioning, Classical/drug effects , Conditioning, Classical/physiology , Discrimination Learning/drug effects , Electric Stimulation , Evoked Potentials/physiology , Fear/physiology , Isoflurane/pharmacology , Male , Mental Recall/drug effects , Mental Recall/physiology , Neuronal Plasticity , Olfactory Perception/physiology , Prefrontal Cortex/drug effects , Prefrontal Cortex/physiology , Rats , Recognition, Psychology/drug effects
7.
J Dairy Sci ; 95(1): 247-54, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22192204

ABSTRACT

The objective of the study was to estimate the prevalence and incidence of Mycoplasma bovis, a common cause of pneumonia, in veal calves. Using simple random sampling, 252 calves from 4 veal herds located in central Pennsylvania were selected and longitudinally followed for monthly collection of nasal swabs. Bronchial swabs and lung lesions were collected at the slaughterhouse. Nasal, bronchial, and lung lesion swabs were cultured for bacterial respiratory pathogens. Ninety lung lesions were identified, of which 41.1, 1.1, 1.1, 7.8, and 4.4% were culture positive for M. bovis alone, Pasteurella multocida alone, Mannheimia haemolytica alone, M. bovis and P. multocida co-infection, and M. bovis and M. haemolytica co-infection, respectively. The data indicate that potential interventions, such as therapeutics, vaccines, or management control measures, would be most effective before 50 d of age based upon the cumulative incidence of colonization.


Subject(s)
Mycoplasma Infections/veterinary , Mycoplasma bovis , Animals , Animals, Newborn/microbiology , Cattle , Incidence , Lung/microbiology , Mycoplasma Infections/epidemiology , Mycoplasma Infections/microbiology , Pennsylvania/epidemiology , Pneumonia, Bacterial/epidemiology , Pneumonia, Bacterial/microbiology , Pneumonia, Bacterial/veterinary , Prevalence , Respiratory System/microbiology
8.
Br J Pharmacol ; 156(2): 316-27, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19154437

ABSTRACT

BACKGROUND AND PURPOSE: Prostanoid EP(4) receptor antagonists may have therapeutic utility in the treatment of migraine since EP(4) receptors have been shown to be involved in prostaglandin (PG)E(2)-induced cerebral vascular dilatation, which may be an important contributor to migraine pain. This study reports the pharmacological characterization of BGC20-1531, a novel EP(4) receptor antagonist. EXPERIMENTAL APPROACH: BGC20-1531 was characterized in radioligand binding and in vitro functional assays employing recombinant and native EP(4) receptors. Changes in canine carotid haemodynamics were used to assess the pharmacodynamic profile of BGC20-1531 in vivo. KEY RESULTS: BGC20-1531 exhibited high affinity at recombinant human EP(4) receptors expressed in cell lines (pK(B) 7.6) and native EP(4) receptors in human cerebral and meningeal artery (pK(B) 7.6-7.8) but showed no appreciable affinity at a wide range of other receptors (including other prostanoid receptors), channels, transporters and enzymes (pKi < 5). BGC20-1531 competitively antagonized PGE(2)-induced vasodilatation of human middle cerebral (pK(B) 7.8) and meningeal (pK(B) 7.6) arteries in vitro, but had no effect on responses induced by PGE(2) on coronary, pulmonary or renal arteries in vitro. BGC20-1531 (1-10 mg.kg(-1) i.v.) caused a dose-dependent antagonism of the PGE(2)-induced increase in canine carotid blood flow in vivo. CONCLUSIONS AND IMPLICATIONS: BGC20-1531 is a potent and selective antagonist at EP(4) receptors in vitro and in vivo, with the potential to alleviate the symptoms of migraine that result from cerebral vasodilatation. BGC20-1531 is currently in clinical development for the treatment of migraine headache.


Subject(s)
Migraine Disorders/drug therapy , Pyridines/pharmacology , Receptors, Prostaglandin E/antagonists & inhibitors , Sulfonamides/pharmacology , Vasodilator Agents/pharmacology , Adult , Aged , Animals , Carotid Artery, Common/drug effects , Carotid Artery, Common/physiology , Cell Line , Cerebral Arteries/drug effects , Cerebral Arteries/physiology , Dinoprostone/pharmacology , Dogs , Dose-Response Relationship, Drug , Female , Humans , In Vitro Techniques , Male , Meningeal Arteries/drug effects , Meningeal Arteries/physiology , Middle Aged , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/physiology , Pyridines/adverse effects , Pyridines/therapeutic use , Radioligand Assay , Receptors, Prostaglandin E, EP4 Subtype , Recombinant Proteins/antagonists & inhibitors , Sulfonamides/adverse effects , Sulfonamides/therapeutic use , Vasoconstriction/drug effects , Vasodilator Agents/adverse effects , Vasodilator Agents/therapeutic use , Young Adult
9.
Phys Rev E Stat Nonlin Soft Matter Phys ; 70(2 Pt 1): 021909, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15447517

ABSTRACT

Evidence is presented that adds to the debate surrounding the question: To what extent does neural control of cardiac output exploit noise? The transduction capability of cardiac afferent neurons, situated in and adjacent to the heart, is vital to feedback in control of cardiac function. An analysis of in situ cardiac afferent activity shows evidence of independent and exponentially distributed interspike intervals. An anatomical basis for such memoryless interspike intervals ultimately derives from the fact that each afferent neuron is associated with a field of sensory neurites, or bare nerve endings, that transduce local chemical and mechanical stimuli in a many-to-one fashion. As such, cardiac afferent neurons and their sensory neurite inputs are respectively modeled here by the Hodgkin-Huxley equations forced by "red" noise (decaying power spectrum) perturbing an otherwise constant subthreshold input. A variable barrier competition model is derived from these equations in order to address the question: How are noisy inputs being processed by sensory neurons to cause each spike? It is found that ion channels are responsible for significant input "whitening" (increased spectral power at higher frequency) through differentiation of the inputs. Such whitening is a means to distinguish low-frequency control signals from otherwise red noise fluctuations. Furthermore, spiking occurs when backward moving averages of the whitened inputs, over a window of the order of the sodium activation time scale, exceed an approximately constant barrier.


Subject(s)
Biophysics/methods , Heart/physiology , Neurons, Afferent/physiology , Neurons/metabolism , Action Potentials , Animals , Humans , Models, Neurological , Models, Statistical , Models, Theoretical , Probability , Stochastic Processes , Time Factors
10.
Equine Vet J ; 33(6): 577-84, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11720029

ABSTRACT

The purpose of this study was to examine the effects of an external nasal strip (NS), frusemide (FR) and a combination of the 2 treatments (NS + FR) on exercise-induced pulmonary haemorrhage (EIPH) in Thoroughbred horses. It was hypothesised that both the NS and FR would attenuate EIPH as assessed by red blood cell count in bronchoalveolar lavage fluid. In random order, 8 horses completed each of 4 sprint exercise tests on a treadmill: 1) NS; 2) FR (0.5 mg/kg bwt i.v., 4 h pre-exercise); 3) NS + FR; and 4) control (C; no treatment). After a 5 min warm-up (4.5 m/s), horses completed 2 min running at 120% maximum oxygen consumption (VO2max) with the treadmill set at 3 degrees incline. Mean +/- s.d. running speed was 14.2+/-0.2 m/s. In the FR and NS + FR trials, horses carried weight equal to that lost as a result of frusemide administration. During exercise at 120% Vo2max, oxygen consumption (Vo2) and carbon dioxide production (Vco2) were measured at 15 s intervals. Plasma lactate concentration was measured in samples collected before exercise, at the end of the sprint and after 5 min cool-down at the trot. Thirty minutes after the run, bronchoalveolar lavage (BAL) was performed and the red cell count in the fluid quantified. Vo2 and Vco2 were significantly lower in NS and NS + FR trials than in the C and FR trials at the end of the sprint exercise protocol. However, plasma lactate concentrations did not differ among treatments. Compared with the C trial (61.1+/-30.5 x 10(6) red blood cells/ml BAL fluid), pulmonary haemorrhage was significantly (P<0.05) decreased in both the NS (15.9+/-4.0 x 106 RBC/ml) and FR (12.2+/-5.8 x 10(6) RBC/ml) trials. EIPH in the NS + FR trial (7.9+/-1.0 x 10(6) RBC/ml) was further diminished (P<0.05) compared to the NS trial, but not different from the FR trial. We conclude that both the external nasal strip and frusemide attenuate pulmonary haemorrhage in Thoroughbred horses during high-speed sprint exercise. The external nasal strip appears to lower the metabolic cost of supramaximal exertion in horses. Given the purported ergogenic effects of frusemide, the external nasal strip is a valuable alternative for the attenuation of EIPH.


Subject(s)
Diuretics/therapeutic use , Furosemide/therapeutic use , Hemorrhage/veterinary , Horse Diseases/prevention & control , Lung Diseases/veterinary , Physical Conditioning, Animal/adverse effects , Animals , Body Weight/drug effects , Bronchoalveolar Lavage Fluid/cytology , Carbon Dioxide/metabolism , Combined Modality Therapy , Diuretics/pharmacology , Erythrocyte Count/veterinary , Exercise Test/veterinary , Female , Furosemide/pharmacology , Hemorrhage/prevention & control , Horses , Lactates/blood , Lung Diseases/prevention & control , Male , Oxygen Consumption/drug effects , Pulmonary Gas Exchange/drug effects , Random Allocation , Time Factors
11.
Neuromuscul Disord ; 11(6-7): 579-82, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11525888

ABSTRACT

Neuromuscular blocking agents are routinely used as an adjunct therapy for critically ill patients. Unlike many neuromuscular blocking agents, vecuronium does not cause significant histamine release, which may lead to bronchoconstriction. Due to a short duration of action and limited accumulation, vecuronium has been widely used. Prolonged ventilatory dependence due to persistent neuromuscular blockade has been reported in patients treated with vecuronium. We report a case of an 8-year-old girl who had a primarily motor axonopathy presenting with weakness after extended vecuronium administration with prolonged course of recovery. This primarily motor neuropathy with axonal features may be a variant of critical illness polyneuropathy, a rarely reported condition in pediatric patients.


Subject(s)
Motor Neuron Disease/chemically induced , Motor Neuron Disease/diagnosis , Neuromuscular Nondepolarizing Agents/adverse effects , Polyneuropathies/chemically induced , Polyneuropathies/diagnosis , Vecuronium Bromide/adverse effects , Child , Electromyography , Female , Humans , Motor Neuron Disease/classification , Neural Conduction/drug effects , Polyneuropathies/classification , Recovery of Function
12.
J Appl Physiol (1985) ; 91(3): 1396-400, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11509541

ABSTRACT

The purpose of this investigation was to study the effects of an equine nasal strip (NS), furosemide (Fur), and a combination of both (NS + Fur) on exercise-induced pulmonary hemorrhage (EIPH) at speeds corresponding to near-maximal effort. Five Thoroughbreds (526 +/- 25 kg) were run on a flat treadmill from 7 to 14 m/s in 1 m x s(-1) x min(-)1 increments every 2 wk (treatment order randomized) under control (Con), Fur (1 mg/kg iv 4 h prior), NS, or NS + Fur conditions. During each run, pulmonary arterial (Ppa) and esophageal (Pes) pressures were measured. Severity of EIPH was quantified via bronchoalveolar lavage (BAL) 30 min postrun. Furosemide (Fur and NS + Fur trials) reduced peak Ppa approximately 7 mmHg compared with Con (P < 0.05) whereas NS had no effect (P > 0.05). Maximal Pes swings were not different among groups (P > 0.05). NS significantly diminished EIPH compared with the Con trial [Con, 55.0 +/- 36.2; NS, 30.8 +/- 21.8 x 10(6) red blood cells (RBC)/ml BAL fluid; P < 0.05]. Fur reduced EIPH to a greater extent than NS (5.2 +/- 3.0 x 10(6) RBC/ml BAL; P < 0.05 vs. Con and NS) with no additional benefit from NS + Fur (8.5 +/- 4.2 x 10(6) RBC/ml BAL; P > 0.05 vs. Fur, P < 0.05 vs. Con and NS). In conclusion, although both modalities (NS and Fur) were successful in mitigating EIPH, neither abolished EIPH fully as evaluated via BAL. Fur was more effective than NS in constraining the severity of EIPH. The simultaneous use of both interventions appears to offer no further gain with respect to reducing EIPH.


Subject(s)
Diuretics/pharmacology , Furosemide/pharmacology , Hemorrhage/drug therapy , Hemorrhage/veterinary , Horse Diseases/drug therapy , Animals , Blood Pressure , Body Weight , Bronchoalveolar Lavage Fluid , Esophagus/physiology , Hemorrhage/prevention & control , Horses , Male , Nose , Physical Exertion , Pulmonary Circulation/physiology
13.
Phys Rev E Stat Nonlin Soft Matter Phys ; 63(4 Pt 1): 041911, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11308881

ABSTRACT

Regional cardiac control depends upon feedback of the status of the heart from afferent neurons responding to chemical and mechanical stimuli as transduced by an array of sensory neurites. Emerging experimental evidence shows that neural control in the heart may be partially exerted using subthreshold inputs that are amplified by noisy mechanical fluctuations. This amplification is known as aperiodic stochastic resonance (ASR). Neural control in the noisy, subthreshold regime is difficult to see since there is a near absence of any correlation between input and the output, the latter being the average firing (spiking) rate of the neuron. This lack of correlation is unresolved by traditional energy models of ASR since these models are unsuitable for identifying "cause and effect" between such inputs and outputs. In this paper, the "competition between averages" model is used to determine what portion of a noisy, subthreshold input is responsible, on average, for the output of sensory neurons as represented by the Fitzhugh-Nagumo equations. A physiologically relevant conclusion of this analysis is that a nearly constant amount of input is responsible for a spike, on average, and this amount is approximately independent of the firing rate. Hence, correlation measures are generally reduced as the firing rate is lowered even though neural control under this model is actually unaffected.


Subject(s)
Heart/innervation , Neurons, Afferent/physiology , Neurons/pathology , Stochastic Processes , Animals , Biophysical Phenomena , Biophysics , Models, Neurological , Models, Statistical , Nerve Net , Synaptic Transmission , Time Factors
15.
Article in English | MEDLINE | ID: mdl-11046466

ABSTRACT

Aperiodic stochastic resonance (ASR) is studied for a densely interconnected population of excitatory and inhibitory neurons that exhibit hysteresis. Switching between states in the presence of noisy external forcing is represented as a "competition between averages" and this is further explained through a semianalytical model. In contrast to energy-based approaches where only the timing of a switch between states is represented, the competition between averages also identifies the input history responsible for a switch. This last point leads to some interesting conclusions regarding cause and effect in the presence of noisy forcing of a hysteretic system. For example, at subthreshold inputs, it is found that the input history causing a switch between states is primarily dependent upon the noise level even though the corresponding time to switch is sensitive to both the distance from the threshold and the noise level. Since the application considered here is to cardiac neuronal control, control performance is considered over the full input range. Noise tuning for adequate control performance is found to be unnecessary if the noise level is high enough. This is consistent with studies of ASR for sensory neurons. Another observation made here that may be of clinical significance is that at higher noise levels, constraints placed upon inputs to ensure adequate control performance are likely to depend upon the switching direction.


Subject(s)
Heart/innervation , Heart/physiology , Models, Neurological , Myocardium/cytology , Neurons/physiology , Monte Carlo Method , Stochastic Processes , Time Factors , Ventricular Pressure/physiology
17.
J Clin Neuromuscul Dis ; 2(1): 18-22, 2000 Sep.
Article in English | MEDLINE | ID: mdl-19078597

ABSTRACT

Although the ekcuodiagnostic abnormalities in botulism have bean well characterized, the expected abnormalities, such as facilitation of compound muscle anion potential amplitudes after sustained activation or with repetitive stimulation at fast tales, may not always be present especially early m the disease. This may lead to etectrodtagnosttc difficulties and sometimes a delay in establishing a diagnosis. We describe four serologically proven cases of type A botulism in adults that illustrate the variability in ekctrodiagnostic findings in this disease.

18.
IEEE Trans Biomed Eng ; 45(7): 942-5, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9644904

ABSTRACT

An electrocardiogram (ECG) compression algorithm based on a combination of the Karhunen-Loeve transform (KLT) and multirate sampling is introduced. The use of multirate sampling reduces KLT computational times to those reported for wavelet-packet-based compression techniques. A beat-by-beat quality controlled compression criterion is shown to be necessary to ensure clinically adequate reconstruction of each beat. The resulting quality controlled algorithm efficiently achieves compression rates of approximately 30-40:1 for the MIT-BIH database.


Subject(s)
Algorithms , Electrocardiography , Signal Processing, Computer-Assisted , Quality Control
19.
Nucl Med Commun ; 18(7): 662-7, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9342105

ABSTRACT

Twenty-six people with Down's syndrome (DS) were investigated using 99Tc(m)-hexamethylpropylene amine oxime (99Tc(m)-HMPAO) and single photon emission tomography (SPET). Dementia was diagnosed using a structured carer interview giving a deterioration score and by studying the case notes. Five subjects were clinically demented, 7 showed mild deterioration and 14 no deterioration. Increased deterioration correlated with advancing age (correlation coefficient 0.5425; P<0.02), but there was no significant difference between older (>40 years) and younger (<40 years) patients. Only one of the subjects with dementia had a regional cerebral blood flow (rCBF) abnormality that was of the dementia of Alzheimer type. Three subjects with mild deterioration and three with no deterioration had abnormal SPET scans. There was no association between the SPET abnormality and clinical dementia or with evidence of deterioration.


Subject(s)
Brain/diagnostic imaging , Dementia/diagnostic imaging , Down Syndrome/diagnostic imaging , Down Syndrome/psychology , Technetium Tc 99m Exametazime , Tomography, Emission-Computed, Single-Photon , Adult , Age Factors , Dementia/etiology , Dementia/psychology , Female , Humans , Intellectual Disability/diagnostic imaging , Intellectual Disability/psychology , Male
20.
Rhinology ; 35(2): 50-2, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9299650

ABSTRACT

Snoring is a significant problem both for the patient and for the bedpartner. It is well known that nasal stuffiness can contribute to snoring, and sleep quality may deteriorate because of the snoring. Nasal dilation can reduce snoring and improve sleep. Thirty-five habitual snorers (18 female, 17 male) and their bedpartners participated in an open label study. The patients were diagnosed as heavy snorers after they underwent overnight polysomnography showing that their apnoea indexes were below 5, thus sleep apnoea patients were not included in the study. The participants and their partners filled out evaluations concerning snoring intensity, mouth dryness and Epworth Sleepiness Scale prior to and after using Breath Right nasal strips for 14 consecutive nights. The Breathe Right external nasal dilator is a simple, nonpharmaceutical method to decrease nasal airway resistance and thus potentially reduce or eliminate snoring. After using the strips there were statistically significant decreases in snoring (p < 0.001) as graded by the bed partner, and in mouth dryness (p = 0.025) and in the Epworth Sleepiness Scale scores (p = 0.001), as graded by the patient. The results of this study indicate that Breathe Right nasal strips may be used to reduce snoring, mouth dryness and sleepiness in patients presenting with symptoms of snoring.


Subject(s)
Nasal Obstruction/therapy , Snoring/prevention & control , Dilatation/instrumentation , Evaluation Studies as Topic , Female , Humans , Male , Nasal Obstruction/complications , Snoring/etiology
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