RESUMEN
Lifespan variation adds to life expectancy by measuring the inequality surrounding age of death that a population faces. Countries that tackle premature mortality generally have decreasing lifespan variation but this is the first study to compare and statistically assess when and to what extent trends in lifespan variation have changed across Western Europe. Lifespan variation was measured using e and joinpoint regression analysed the timing and rate of change. Trends have been mostly downward with the recent exception of men in Scotland, Northern Ireland, Ireland and Finland where trends have flattened or show slight increases. Future research aimed at identifying the ages and causes of death, driving trends in these countries, is key to preventing increasing inequalities.
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Esperanza de Vida/tendencias , Distribución por Edad , Europa (Continente)/epidemiología , Humanos , Grupos Raciales , Distribución por SexoRESUMEN
BACKGROUND: Glasgow's low life expectancy and high levels of deprivation are well documented. Studies comparing Glasgow to similarly deprived cities in England suggest an excess of deaths in Glasgow that cannot be accounted for by deprivation. Within Scotland comparisons are more equivocal suggesting deprivation could explain Glasgow's excess mortality. Few studies have used life expectancy, an intuitive measure that quantifies the between-city difference in years. This study aimed to use the most up-to-date data to compare Glasgow to other Scottish cities and to (i) evaluate whether deprivation could account for lower life expectancy in Glasgow and (ii) explore whether the age distribution of mortality in Glasgow could explain its lower life expectancy. METHODS: Sex specific life expectancy was calculated for 2007-2011 for the population in Glasgow and the combined population of Aberdeen, Dundee and Edinburgh. Life expectancy was calculated for deciles of income deprivation, based on the national ranking of datazones, using the Scottish Index of Multiple Deprivation. Life expectancy in Glasgow overall, and by deprivation decile, was compared to that in Aberdeen, Dundee and Edinburgh combined, and the life expectancy difference decomposed by age using Arriaga's discrete method. RESULTS: Life expectancy for the whole Glasgow population was lower than the population of Aberdeen, Dundee and Edinburgh combined. When life expectancy was compared by national income deprivation decile, Glasgow's life expectancy was not systematically lower, and deprivation accounted for over 90 % of the difference. This was reduced to 70 % of the difference when carrying out sensitivity analysis using city-specific income deprivation deciles. In both analyses life expectancy was not systematically lower in Glasgow when stratified by deprivation. Decomposing the differences in life expectancy also showed that the age distribution of mortality was not systematically different in Glasgow after accounting for deprivation. CONCLUSIONS: Life expectancy is not systematically lower across the Glasgow population compared to Aberdeen, Dundee and Edinburgh combined, once deprivation is accounted for. This provides further evidence that tackling deprivation in Glasgow would probably reduce the health inequalities that exist between Scottish cities. The change in the amount of unexplained difference when carrying out sensitivity analysis demonstrates the difficulties in comparing socioeconomic deprivation between populations, even within the same country and when applying an established ecological measure. Although the majority of health inequality between Glasgow and other Scottish cities is explained by deprivation, the difference in the amount of unexplained inequality depending on the relative context of deprivation used demonstrates the challenges associated with attributing mortality inequalities to an independent 'place effect'.
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Ciudades , Disparidades en el Estado de Salud , Renta , Esperanza de Vida , Pobreza , Población Urbana , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Muerte , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Escocia/epidemiología , Adulto JovenRESUMEN
Mitochondrial complex I inhibition has been implicated in the degeneration of midbrain dopaminergic (DA) neurons in Parkinson's disease. However, the mechanisms and pathways that determine the cellular fate of DA neurons downstream of the mitochondrial dysfunction have not been fully identified. We conducted cell-type specific gene array experiments with nigral DA neurons from rats treated with the complex I inhibitor, rotenone, at a dose that does not induce cell death. The genome wide screen identified transcriptional changes in multiple cell death related pathways that are indicative of a simultaneous activation of both degenerative and protective mechanisms. Quantitative PCR analyses of a subset of these genes in different neuronal populations of the basal ganglia revealed that some of the changes are specific for DA neurons, suggesting that these neurons are highly sensitive to rotenone. Our data provide insight into potentially defensive strategies of DA neurons against disease relevant insults.
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Muerte Celular/genética , Dopamina/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Rotenona/farmacología , Sustancia Negra/efectos de los fármacos , Activación Transcripcional/efectos de los fármacos , Animales , Peso Corporal/efectos de los fármacos , Complejo I de Transporte de Electrón/antagonistas & inhibidores , Conducta Exploratoria/efectos de los fármacos , Expresión Génica , Perfilación de la Expresión Génica , Masculino , Mitocondrias/efectos de los fármacos , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Ratas , Rotenona/administración & dosificación , Sustancia Negra/metabolismo , Ácido gamma-Aminobutírico/metabolismoRESUMEN
The capture of flying insects by foraging dragonflies is a highly accurate, visually guided behavior. Rather than simply aiming at the prey's position, the dragonfly aims at a point in front of the prey, so that the prey is intercepted with a relatively straight flight trajectory. To better understand the neural mechanisms underlying this behavior, we used high-speed video to quantify the head and body orientation of dragonflies (female Erythemis simplicicollis flying in an outdoor flight cage) relative to an artificial prey object before and during pursuit. The results of our frame-by-frame analysis showed that during prey pursuit, the dragonfly adjusts its head orientation to maintain the image of the prey centered on the "crosshairs" formed by the visual midline and the dorsal fovea, a high acuity streak that crosses midline at right angles about 60 degrees above the horizon. The visual response latencies to drifting of the prey image are remarkably short, ca. 25 ms for the head and 30 ms for the wing responses. Our results imply that the control of the prey-interception flight must include a neural pathway that takes head position into account.
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Movimientos Oculares/fisiología , Vuelo Animal/fisiología , Movimientos de la Cabeza/fisiología , Insectos/fisiología , Conducta Predatoria/fisiología , Animales , Conducta Animal , Grabación en Video/métodosRESUMEN
Spontaneous activity, acoustic startle, and prepulse inhibition (PPI) of acoustic startle were measured in male Sprague-Dawley rats 3-5 h after 0, 10, 15, or 20 mg/kg i.p. 3-nitropropionic acid (3-NP), a mitochondrial toxin. Mean activity was significantly influenced by the 3-NP dose due to decreased activity for 20 mg/kg. Mean startle amplitude was not significantly affected by the 3-NP dose. Means of PPI for prepulses 6 and 12 dBA above background were smaller than means for respective 0 mg/kg doses, but the main effect of 3-NP dose did not reach statistical significance in ANOVA. The changes in measured exploratory-type activity and, possibly, in startle PPI parallel the occurrence of clinical signs exhibited at 3-5 h after 3-NP injection. Neural processing involved in these quantitative behavioral endpoints seems to be affected as energy stores are depleted and degenerative processes are beginning.
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Conducta Exploratoria/efectos de los fármacos , Neurotoxinas/farmacología , Propionatos/farmacología , Reflejo de Sobresalto/efectos de los fármacos , Estimulación Acústica , Análisis de Varianza , Animales , Conducta Exploratoria/fisiología , Masculino , Nitrocompuestos , Estimulación Luminosa , Ratas , Ratas Sprague-Dawley , Reflejo de Sobresalto/fisiologíaRESUMEN
Potential action of ultra-wideband (UWB) electromagnetic field pulses on effects of N(G)-nitro- L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase (NOS), on nociception and locomotor activity was investigated in CF-1 mice. Animals were injected IP with saline or 50 mg/kg L-NAME and exposed for 30 min to no pulses (sham exposure) or UWB pulses with electric field parameters of 102+/-1 kV/m peak amplitude, 0.90+/-0.05 ns duration, and 160+/-5 ps rise time (mean+/-S.D.) at 600/s. Animals were tested for thermal nociceptive responses on a 50 degrees C surface and for spontaneous locomotor activity for 5 min. L-NAME by itself increased mean first-response (paw lift, shake, or lick; jump) and back-paw-lick response latencies and mean locomotor activity. Exposure to UWB pulses reduced the L-NAME-induced increase in back-paw-lick latency by 22%, but this change was not statistically significant. The L-NAME-induced hyperactivity was not present after UWB exposure. Reduction and cancellation of effects of L-NAME suggest activation of opposing mechanism(s) by the UWB pulses, possibly including increase of nitric oxide production by NOS. The action, or actions, of UWB pulses appears to be more effective on locomotor activity than on thermal nociception in CF-1 mice.
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Campos Electromagnéticos , Inhibidores Enzimáticos/efectos adversos , Hipercinesia/inducido químicamente , NG-Nitroarginina Metil Éster/efectos adversos , Óxido Nítrico Sintasa/antagonistas & inhibidores , Análisis de Varianza , Animales , Inhibidores Enzimáticos/administración & dosificación , Hipercinesia/prevención & control , Inyecciones Intraperitoneales , Locomoción/efectos de los fármacos , Locomoción/efectos de la radiación , Masculino , Ratones , Ratones Endogámicos , NG-Nitroarginina Metil Éster/administración & dosificación , Óxido Nítrico Sintasa/efectos de la radiación , Nociceptores/efectos de los fármacos , Nociceptores/efectos de la radiación , Dolor/inducido químicamente , Dolor/prevención & control , Umbral del Dolor/efectos de los fármacos , Umbral del Dolor/efectos de la radiación , Tiempo de Reacción/efectos de los fármacos , Tiempo de Reacción/efectos de la radiación , Cloruro de Sodio , Factores de TiempoRESUMEN
Intense flashes of light were observed in sodium bicarbonate and hydrogen peroxide solutions when they were exposed to pulsed microwave radiation, and the response was greatly enhanced by a microwave-absorbing, biosynthesized polymer, diazoluminomelanin. A FPS-7B radar transmitter, operating at 1.25 GHz provided pulses of 5.73 +/- 0.09 micros in duration at 10.00 +/- 0.03 pulses/s with 2.07 +/- 0.08 MW forward power (mean +/- standard deviation), induced the effect but only when the appropriate chemical interaction was present. This phenomenon involves acoustic wave generation, bubble formation, pulsed luminescence, ionized gas ejection, and electrical discharge. The use of pulsed microwave radiation to generate highly focused energy deposition opens up the possibility of a variety of biomedical applications, including targeting killing of microbes or eukaryotic cells. The full range of microwave intensities and frequencies that induce these effects has yet to be explored and, therefore, the health and safety implications of generating the phenomena in living tissues remain an open question.
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Biopolímeros/efectos de la radiación , Luminol/análogos & derivados , Melaninas/efectos de la radiación , Microondas , Absorción , Acústica , Aire , Biopolímeros/química , Electricidad , Gases/química , Gases/efectos de la radiación , Humanos , Peróxido de Hidrógeno/química , Peróxido de Hidrógeno/efectos de la radiación , Luz , Mediciones Luminiscentes , Luminol/química , Luminol/efectos de la radiación , Melaninas/química , Microondas/clasificación , Microondas/uso terapéutico , Radar , Bicarbonato de Sodio/química , Bicarbonato de Sodio/efectos de la radiación , Sonido , Grabación de Cinta de VideoRESUMEN
PURPOSE: To investigate the extent of genetic damage in the peripheral blood and bone marrow cells of mice exposed to ultra-wideband electromagnetic radiation (UWBR). MATERIALS AND METHODS: CF-1 male mice were exposed to UWBR for 15 min at an estimated whole-body average specific absorption rate of 37 mW x kg(-1). Groups of untreated control and positive control mice injected with mitomycin C were also included in the study. After various treatments, half of the mice were killed at 18 h, and the other half at 24 h. Peripheral blood and bone marrow smears were examined to determine the extent of genotoxicity, as assessed by the presence of micronuclei (MN) in polychromatic erythrocytes (PCE). RESULTS: The percentages of PCE and the incidence of MN per 2000 PCE in both tissues in mice killed at 18 h were similar to the frequencies observed in mice terminated at 24 h. There were no significant differences in the percentage of PCE between control and the mice with or without UWBR exposure; the group mean values (+/- standard deviation) were in the range of 3.1+/-0.14 to 3.2+/-0.23 in peripheral blood, and 49.0+/-3.56 to 52.3+/-4.02 in bone marrow. The mean incidence of MN per 2000 PCE in control and in mice with or without UWBR exposure ranged from 7.7+/-2.00 to 9.7+/-2.54 in peripheral blood and 7.4+/-2.32 to 10.0+/-3.27 in bone marrow. Pairwise comparison of the data did not reveal statistically significant differences between the control and mice with or without UWBR exposure groups (excluding positive controls). CONCLUSION: Under the experimental conditions tested, there was no evidence for excess genotoxicity in peripheral blood or bone marrow cells of mice exposed to UWBR.
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Sangre/efectos de la radiación , Médula Ósea/efectos de la radiación , Campos Electromagnéticos/efectos adversos , Eritrocitos/efectos de la radiación , Animales , Médula Ósea/ultraestructura , Eritrocitos/ultraestructura , Masculino , Ratones , Pruebas de MicronúcleosRESUMEN
Mice were exposed to ultra-wideband (UWB) electromagnetic pulses averaging 99-105 kV/m peak amplitude, 0.97-1.03 ns duration, and 155-174 ps rise time, after intraperitoneal administration of saline or morphine sulfate. They were then tested for thermal nociception on a 50 degrees C surface and for spontaneous locomotor activity and its time profile over 5 min. Analysis of results showed no effect of UWB exposure on nociception and activity measures in CF-1 mice after 15-, 30-, or 45-min exposure to pulses at 600/s or after 30-min exposure to UWB pulses at 60/s. Similarly, no effect was seen in C57BL/6 mice after 30-min exposure to pulses at 60/s or 600/s. Although trends in morphine-modified measures seen with UWB pulse repetition frequency could be expected because of increased levels of low-frequency energy, no significant change was seen in normal or morphine-modified nociception or activity after UWB exposure. This indicated lack of effect of the UWB pulses used in these experiments on nervous system components, including endogenous opioids, involved in these behaviors.
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Analgésicos Opioides/farmacología , Morfina/farmacología , Nociceptores/efectos de los fármacos , Dolor/fisiopatología , Animales , Estimulación Eléctrica , Masculino , Ratones , Ratones Endogámicos C57BL , Actividad Motora/efectos de los fármacos , Dimensión del Dolor/efectos de los fármacosRESUMEN
Exposure to fast-rise-time ultra-wideband (UWB) electromagnetic pulses has been postulated to result in effects on biological tissue (including the cardiovascular system). In the current study, 10 anesthetized Sprague-Dawley rats were exposed to pulses produced by a Sandia UWB pulse generator (average values of exposures over three different pulse repetition rates: rise time, 174-218 ps; peak E field, 87-104 kV/m; pulse duration, 0.97-0.99 ns). Exposures to 50, 500 and 1000 pulses/s resulted in no significant changes in heart rate or mean arterial blood pressure measured every 30 s during 2 min of exposure and for 2 min after the exposure. The results suggest that acute UWB whole-body exposure under these conditions does not have an immediate detrimental effect on these cardiovascular system variables in anesthetized rats.
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Presión Sanguínea/efectos de la radiación , Frecuencia Cardíaca/efectos de la radiación , Animales , Presión Sanguínea/fisiología , Campos Electromagnéticos , Frecuencia Cardíaca/fisiología , Masculino , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
OBJECTIVE: To describe owner experiences with gastrostomy tubes used at home. DESIGN: Telephone survey. ANIMALS: 20 cats and 5 dogs. PROCEDURE: Owner's opinions obtained by phone interview. RESULTS: Although 32% (8/25) of owners were initially reluctant to feed their cat or dog through the gastrostomy tube, 92% (22/24) of owners became comfortable with the procedure. Eighty-four percent (21/25) of owners were able to feed their dog or cat unassisted; 16% (4/25) required another person to help. Median time required for feeding was 19.8 minutes. Ninety-six percent (24/25) of owners believed their dog or cat was comfortable with the procedure. Eighty-four percent (21/25) of owners experienced complications or difficulties. Most problems involved bandage maintenance, administration of food through the syringe and tube, or acquisition of syringes and special foods. Ninety-six percent (22/23) of owners would be willing to use a gastrostomy tube again. CLINICAL IMPLICATIONS: Most owners had positive experiences with the feeding experience and would be willing to use gastrostomy tube feeding again. Difficulties encountered by owners were not serious and could be avoided by specific client instruction.
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Enfermedades de los Gatos/terapia , Enfermedades de los Perros/terapia , Nutrición Enteral/veterinaria , Gastrostomía/veterinaria , Atención Domiciliaria de Salud , Animales , Gatos , Recolección de Datos , Perros , Atención Domiciliaria de Salud/psicología , Vínculo Humano-Animal , TeléfonoRESUMEN
A sensing platform with two piezoelectric transducers was designed and fabricated to measure acoustic startle responses from forelimbs and hindlimbs in the rat. Testing with a vibrator showed that separate forces were measured from 5 to 25 Hz with mean sensitivities of 2.395 and 2.022 V/N and mean linearity errors of 3.23 and 2.98% FS for the forelimb and hindlimb sensors, respectively. Forelimb and hindlimb response waveforms of male Sprague-Dawley rats had shapes similar to the commonly recorded wholebody response but were smaller in amplitude.
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Estimulación Acústica , Ingeniería Biomédica/instrumentación , Miembro Anterior/fisiología , Miembro Posterior/fisiología , Reflejo de Sobresalto/fisiología , Transductores , Animales , Calibración , Diseño de Equipo , Masculino , Presión , Ratas , Ratas Sprague-Dawley , Reproducibilidad de los Resultados , Propiedades de Superficie , VibraciónRESUMEN
Single microwave pulses at 1.25 GHz were delivered to the head and neck of male Long-Evans rats as a prestimulus to acoustic and tactile startle. For acoustic startle, pulses averaging 0.96 microsecond in duration were tested with two specific absorption rate (specific absorption) ranges, 15.0-30.0 kW/kg (16.0-44.2 mJ/kg) and 35.5-86.0 kW/kg (66.6-141.8 mJ/kg), delivered 201, 101, 51, 3, and 1 ms before and 1 ms after onset of a startling noise. The low-intensity pulse did not affect peak amplitude, integral, or latency of the whole-body startle response. The high-intensity pulse at 101 and 51 ms inhibited the startle response by decreasing peak amplitude and integral; at 201 and 51 ms latency was increased. The high-intensity pulse at 1 ms enhanced the startle response by increasing peak amplitude and at 3 ms by increasing integral. For tactile startle, either microwave pulses averaging 7.82 microseconds in duration and 55.9-113.3 kW/kg (525.0-1055.7 mJ/kg) or 94 dB SPL clicks were delivered 157, 107, 57, and 7 ms before and 43 ms after onset of a startling air burst. The microwave pulse at 57 ms inhibited the startle response by decreasing peak amplitude; at 157, 107, 57, and 7 ms it increased latency. The microwave pulse at 43 ms after onset enhanced the startle response by increasing peak amplitude. The acoustic click at 157 and 57 ms inhibited the startle response by decreasing peak amplitude; at 157,2 107, and 57 ms it increased latency.(ABSTRACT TRUNCATED AT 250 WORDS)
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Percepción Auditiva/efectos de la radiación , Microondas , Inhibición Neural/efectos de la radiación , Reflejo de Sobresalto/efectos de la radiación , Tacto/efectos de la radiación , Estimulación Acústica , Animales , Atención/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Masculino , Ratas , Tiempo de Reacción/efectos de la radiaciónRESUMEN
In a multicentre, double-blind, parallel-group study, the efficacy and safety of a single application of terbinafine 1% cream was compared with 3, 5 and 7 days' once-daily therapy in the treatment of tinea pedis and tinea corporis/cruris. Seventy-eight patients with tinea pedis (58 male, 20 female; mean age 36, range 19-80) and 21 patients with tinea corporis or tinea cruris (16 male, 5 female; mean age 37, range 22-72), presenting in general practice, were entered into the study. Of these, 65 patients with tinea pedis and 14 with tinea corporis or cruris completed the study and were evaluable. Twenty-eight days after commencing therapy 78, 83, 82 and 83% of patients with tinea pedis in the 1-, 3-, 5-, and 7-day treatment groups, respectively, were mycologically cured, and 61, 78, 71 and 67%, respectively, were 'effectively treated'. There was no statistically significant difference between treatment groups. Similarly high cure rates were seen in patients with tinea corporis and tinea cruris. Three months after commencing therapy there was little evidence of relapse. The study shows that there is a significant potential for short-duration therapy with terbinafine 1% cream in tinea infections of the skin, emphasized here by the high cure rates obtained following a single application.
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Antifúngicos/administración & dosificación , Naftalenos/administración & dosificación , Tiña/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Antifúngicos/uso terapéutico , Método Doble Ciego , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Naftalenos/uso terapéutico , Terbinafina , Tiña del Pie/tratamiento farmacológicoRESUMEN
In a multicentre, double-blind, randomized, parallel group study in general practice, 269 patients with clinically diagnosed fungal infection of the skin were treated with either naftifine (Exoderil) or 1% clotrimazole plus 1% hydrocortisone (CHC; Canesten HC) applied twice daily for 4 weeks. Only 115 patients were shown subsequently to have a fungal infection by laboratory tests; the others had inflammatory disease of unknown aetiology. In those with fungal disease, both treatments were equally effective in terms of mycological cure (negative microscopy and culture). Clinical results for all 265 patients showed no clinically identifiable difference between the two preparations in terms of resolution of the disease, indicating that naftifine does have anti-inflammatory activity at least equal to CHC. This study suggests that there is no clinical advantage in treating patients with clinically diagnosed fungal infection of the skin with an antimycotic/corticosteroid combination as opposed to naftifine alone.
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Alilamina/análogos & derivados , Antiinflamatorios no Esteroideos/uso terapéutico , Antifúngicos/uso terapéutico , Dermatomicosis/tratamiento farmacológico , Administración Tópica , Adolescente , Adulto , Anciano , Alilamina/uso terapéutico , Antiinflamatorios/uso terapéutico , Niño , Clotrimazol/uso terapéutico , Método Doble Ciego , Combinación de Medicamentos , Femenino , Humanos , Hidrocortisona , Masculino , Persona de Mediana EdadRESUMEN
Inter-beat intervals of aggregated cardiac cells from chicken embryos were studied during 190 s exposures to 2.45 GHz microwaves in an open-ended coaxial device. Averaged specific-absorption rates (SARs) and modulation conditions were 1.2-86.9 W/kg continuous-wave (CW), 1.2-12.2 W/kg pulse modulation (PW, duty cycle approximately 11%), and 12.0-43.5 W/kg square-wave modulation (duty cycle = 50%). The inter-beat interval decreased during microwave exposures at 42.0 W/kg and higher when CW or square-wave modulation was used, which is consistent with established effects of elevated temperatures. However, increases in the inter-beat interval during CW exposures at 1.2-12.2 W/kg, and decreases in the inter-beat interval after PW exposures at 8.4-12.2 W/kg, are not consistent with simple thermal effects. Analysis of variance indicated that SAR, modulation, and the modulation-SAR interaction were all significant factors in altering the inter-beat interval. The latter two factors indicated that the cardiac cells were affected by athermal as well as thermal effects of microwave exposure.
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Agregación Celular/fisiología , Microondas , Contracción Miocárdica/fisiología , Miocardio/citología , Animales , Embrión de PolloRESUMEN
Single, 1.25-GHz microwave pulses of 0.8- to 1.0-microseconds duration were presented to each of four rats 100 ms before presentation of a startle-inducing acoustic stimulus. This sequential pairing of microwave pulse and acoustic stimulus was found to modify the startle response. At an energy dose to the head of 22-43 mJ/kg per pulse (peak SAR, 23-48 kW/kg), the mean latency to the startle response was longer and the mean amplitude of the response was smaller with respect to control responses that occurred to acoustic stimuli alone. However, at a higher energy dose per microwave pulse in the range of 59-107 mJ/kg (peak SAR, 63-111 kW/kg), the mean latency and amplitude of the startle response were not statistically different from the respective means of control responses.
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Estimulación Acústica , Microondas , Reflejo de Sobresalto/efectos de la radiación , Animales , Masculino , Ratas , Reflejo de Sobresalto/fisiologíaRESUMEN
A method for recording evoked potentials from the eighth nerve of frogs is described. A prominent bipolar wave with latency of 3-6 ms recorded in response to auditory stimuli in Rana catesbeiana is attributable to eighth-nerve activity. The evoked potential provides an integrated response for study of inner ear and peripheral neural activity which complements responses obtained by other recording methods.
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Potenciales Evocados Auditivos , Rana catesbeiana/fisiología , Nervio Vestibulococlear/fisiología , Estimulación Acústica , Animales , Femenino , Masculino , MétodosRESUMEN
Action potentials of neurons in cat dorsal and posteroventral cochlear nuclei were recorded extracellularly with glass microelectrodes while the head of the cat was exposed to microwave pulses at 915 MHz using a diathermy applicator. Response thresholds to acoustic tones, acoustic clicks, and microwave pulses were determined for auditory units with characteristic frequencies (CFs) from 278 Hz to 39.2 kHz. Tests with pulsatile stimuli were performed for durations of 20-700 mus, principally 20, 70, and 200 mus. Brainstem midline specific absorption rate (SAR) threshold was as small as 11.1 mW/g per pulse, and specific absorption (SA) threshold was a small as 0.6 muJ/g per pulse. Microwave thresholds were generally lower for CF less than 9 kHz, as were most acoustic thresholds. However, microwave threshold was only weakly related to click threshold and CF-tone threshold of each unit.
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Audición/efectos de la radiación , Puente/efectos de la radiación , Ondas de Radio , Animales , Gatos , Potenciales Microfónicos de la Cóclea/efectos de la radiación , Nervio Coclear/fisiología , Nervio Coclear/efectos de la radiación , Neuronas/efectos de la radiación , Puente/fisiología , Umbral SensorialRESUMEN
Muscle soreness, serum creatine kinase (CK), and serum and urinary hydroxyproline levels were examined following muscle over-exertion and resistance training. Seven untrained men performed high intensity leg-extension exercises at a resistance at which they could initially accomplish 90% of their 10 repetitions maximum (10 RM), for 30 minutes to induce muscle over-exertion. In Phase 1 a single bout of muscular over-exertion was followed by a week of rest. Phase 2, the training period, was a repeat of the over-exertion workload of Phase 1 for five consecutive days. Phase 3 was a single bout of over-exertion at a higher 10 RM workload. Normo-responsive and hyper-responsive changes in serum CK were exhibited by different subjects in Phase 1. Muscle soreness was perceived by both groups but to a greater extent in the hyper-responsive group. Serum CK and muscle soreness values were lower during Phase 2 and 3 than in Phase 1. Neither serum nor urinary hydroxyproline levels changed significantly post-exercise. These findings show that a single bout of intense exercise and a brief period of muscular training reduces serum CK and muscle soreness responses following a subsequent single bout of exercise at a higher intensity.