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1.
J Perinatol ; 36(1): 30-4, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26334399

RESUMEN

OBJECTIVE: Summarize policies that support maternal and neonatal transport among states and territories. STUDY DESIGN: Systematic review of publicly available, web-based information on maternal and neonatal transport for each state and territory in 2014. Information was abstracted from published rules, statutes, regulations, planning documents and program descriptions. Abstracted information was summarized within two categories: transport and reimbursement. RESULTS: Sixty-eight percent of states and 25% of territories had a policy for neonatal transport; 60% of states and one territory had a policy for maternal transport. Sixty-two percent of states had a reimbursement policy for neonatal transport, whereas 20% reimbursed for maternal transport. Thirty-two percent of states had an infant back-transport policy while 16% included back-transport for both. No territories had reimbursement or back-transport policies. CONCLUSION: The lack of development of maternal transport reimbursement and neonatal back-transport policies negatively impacts the achievements of risk-appropriate care, a strategy focused on improving perinatal outcomes.


Asunto(s)
Reembolso de Seguro de Salud/legislación & jurisprudencia , Atención Perinatal/legislación & jurisprudencia , Transporte de Pacientes/legislación & jurisprudencia , Femenino , Humanos , Recién Nacido , Embarazo , Estados Unidos
2.
J Appl Physiol (1985) ; 107(2): 379-88, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19407259

RESUMEN

The Institute of Medicine expressed a need for improved sweating rate (msw) prediction models that calculate hourly and daily water needs based on metabolic rate, clothing, and environment. More than 25 years ago, the original Shapiro prediction equation (OSE) was formulated as msw (g.m(-2).h(-1))=27.9.Ereq.(Emax)(-0.455), where Ereq is required evaporative heat loss and Emax is maximum evaporative power of the environment; OSE was developed for a limited set of environments, exposures times, and clothing systems. Recent evidence shows that OSE often overpredicts fluid needs. Our study developed a corrected OSE and a new msw prediction equation by using independent data sets from a wide range of environmental conditions, metabolic rates (rest to 500 observations) by using a variety of metabolic rates over a range of environmental conditions (ambient temperature, 15-46 degrees C; water vapor pressure, 0.27-4.45 kPa; wind speed, 0.4-2.5 m/s), clothing, and equipment combinations and durations (2-8 h). Data are expressed as grams per square meter per hour and were analyzed using fuzzy piecewise regression. OSE overpredicted sweating rates (P<0.003) compared with observed msw. Both the correction equation (OSEC), msw=147.exp (0.0012.OSE), and a new piecewise (PW) equation, msw=147+1.527.Ereq-0.87.Emax were derived, compared with OSE, and then cross-validated against independent data (21 males and 9 females; >200 observations). OSEC and PW were more accurate predictors of sweating rate (58 and 65% more accurate, P<0.01) and produced minimal error (standard error estimate<100 g.m(-2).h(-1)) for conditions both within and outside the original OSE domain of validity. The new equations provide for more accurate sweat predictions over a broader range of conditions with applications to public health, military, occupational, and sports medicine settings.


Asunto(s)
Regulación de la Temperatura Corporal , Ingestión de Líquidos , Modelos Biológicos , Sudoración , Equilibrio Hidroelectrolítico , Agua/metabolismo , Superficie Corporal , Vestuario , Metabolismo Energético , Ejercicio Físico , Femenino , Lógica Difusa , Humanos , Cinética , Masculino , Medicina Militar , Medicina del Trabajo , Reproducibilidad de los Resultados , Medicina Deportiva , Temperatura , Presión de Vapor , Viento
3.
J Neurophysiol ; 97(3): 2410-22, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17229828

RESUMEN

Given that studying neural bases of actions is very challenging with fMRI, numerous experiments have used pantomimed actions as a proxy to studying neural circuits of real actions. However, the underlying assumption that the same neural mechanisms mediate real and pantomimed actions has never been directly tested. Moreover, the assumption is called into question by neuropsychological evidence suggesting that real actions depend on the dorsal stream of visual processing whereas pretend actions also recruit the ventral stream. Here, we directly tested these ideas in neurologically intact subjects. Ten right-handed participants performed four tasks: 1) grasping real three-dimensional objects, 2) reaching toward the objects and touching them with the knuckle without hand preshaping, 3) pantomimed grasping in an adjacent location where no object was present, and 4) pantomimed reaching toward an adjacent location. As expected, in the anterior intraparietal area, there was significantly higher activation during real grasping than that during real reaching. However, the activation difference between pantomimed grasping and pantomimed reaching did not reach statistical significance. There was also no effect of pantomimed grasping within the ventral stream, including an object-selective area in the lateral occipital cortex. Instead, we found that pantomimed grasping was mediated by right-hemisphere activation, particularly the right parietal cortex. These results suggest that areas typically invoked by real actions may not necessarily be driven by "fake" actions. Moreover, pantomimed grasping may not tap object-related areas within the ventral stream, but rather may rely on mechanisms within the right hemisphere that are recruited by artificial and less practiced actions.


Asunto(s)
Mapeo Encefálico , Encéfalo/irrigación sanguínea , Encéfalo/fisiología , Decepción , Fuerza de la Mano/fisiología , Imagen por Resonancia Magnética , Adulto , Análisis de Varianza , Femenino , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Oxígeno/sangre , Desempeño Psicomotor
5.
Br J Radiol ; 71(845): 517-27, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9691897

RESUMEN

A survey of radiation dose and compressed breast thickness was conducted in samples of women undergoing mammography in the United Kingdom National Health Service breast screening programme. The aims were to determine the average value and distribution of dose and thickness, and to identify technical difficulties in carrying out such a survey. Values of breast thickness and mean glandular dose, calculated from exposure factors and measured X-ray beam parameters, were collected for 4633 women in 92 screening units in 1994 and 1995. The median (lower quartile, upper quartile) dose per film was 1.7 (1.2, 2.4) mGy for the mediolateral oblique view (mean thickness 57 mm) and 1.4 (1.1, 2.0) mGy for the craniocaudal view (mean thickness 52 mm). The median dose per woman was 1.8 (1.3, 2.5) mGy for a one-view examination and 3.3 (2.3, 4.6) mGy for a two-view examination. The dose per film showed an exponential relationship to breast thickness, but no relationship was found between median dose and median breast thickness in the different screening units, possibly because of errors in breast thickness measurement. The values of breast thickness and dose were generally consistent with those in other published surveys, allowing for differences in radiographic technique. No relationship between breast dose and standard optical density was demonstrated. Some recommendations for the conduct of future surveys of breast dose in the UK are proposed.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Mama/efectos de la radiación , Mamografía , Tamizaje Masivo , Dosis de Radiación , Mama/anatomía & histología , Neoplasias de la Mama/prevención & control , Femenino , Encuestas de Atención de la Salud/métodos , Humanos , Mamografía/efectos adversos , Mamografía/normas , Persona de Mediana Edad , Proyectos Piloto , Reino Unido
7.
J Bone Joint Surg Am ; 79(10): 1489-97, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9378734

RESUMEN

We examined the femora of 2665 adult human skeletons from an osteological collection to determine the prevalence of post-slip morphology termed femoral head-tilt deformity by Murray and pistol-grip deformity by Stulberg et al. The hypothesis was that primary osteoarthrosis of the hip is a secondary manifestation of a subclinical developmental disorder of the hip. The prevalence of post-slip morphology was 8 per cent (215 of 2665 skeletons). Severe osteoarthrosis was more prevalent in association with post-slip morphology (116 [38 per cent] of 306 hips) than in the matched controls (seventy-nine [26 per cent] of 306 hips) (p < 0.005). In the skeletons that had unilateral post-slip morphology, severe osteoarthrosis was more prevalent in the involved hips (thirty-one [37 per cent] of eighty-three) than in the contralateral, normal hips (eighteen [22 per cent] of eighty-three) (p < 0.05). Post-slip morphology, which was unrelated to age, was found to be a major risk factor for the development of high-grade osteoarthrosis. We noted evidence of high-grade osteoarthrosis in sixty-three (68 percent) of the ninety-three hips with minimum post-slip morphology in skeletons from individuals who had been fifty-six years old or more at the time of death compared with forty-five (48 percent) of the ninety-three control hips. This difference was significant (p < 0.025) [corrected]. The osteoarthrosis in the hips with post-slip morphology was distinctly characterized by anterior flattening of the acetabulum, cystic degeneration in the anterior metaphyseal-epiphyseal region, and progression to global osteoarthrosis of the hip.


Asunto(s)
Epífisis Desprendida/complicaciones , Cabeza Femoral/patología , Osteoartritis de la Cadera/etiología , Acetábulo/patología , Adulto , Envejecimiento/patología , Epífisis Desprendida/epidemiología , Epífisis Desprendida/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis de la Cadera/epidemiología , Osteoartritis de la Cadera/patología , Prevalencia , Factores de Riesgo
8.
Artículo en Inglés | MEDLINE | ID: mdl-9004340

RESUMEN

1. Cyclothymia is characterized by pronounced but not debilitating shifts of moods often lasting approximately two to nine weeks. 2. It can be classified as a psychopathologic mood disorder on a continuum to Bipolar II, or as a chronobiologic rhythm similar to the circadian except on an infradian time scale. 3. A male subject diagnosed cyclothymic agreed to daily chart moods and emotions, record dreams and monitor physical states. He kept track of hypomania-depression, high-low energy, high-low tension, dream affect and sleep parameters. 4. In the 1,006 affective cycles recorded between 1977 and 1996, four affective phases appeared sequentially: being comparable to early hypomania (I, PA), late hypomania (II, PD), early depression (III, ND) and late depression (IV, NA). 5. During the experiment lasting 20 years, the frequency of the four-phase affective cycle increased intermittently from 30.3 days (1977) to 28.0 days (1980), 24.7 days (1983), 19.0 days (1986), 17.8 days (1989), 12.1 days (1992), and 1.3 days (1995). 6. These findings of a four-phase variable infradian rhythm may have utility in determining fine structure and time course of rhythms in cyclothymics, both medicated and non-medicated, studied outside the clinical laboratory.


Asunto(s)
Trastorno Ciclotímico/psicología , Adulto , Trastorno Bipolar/psicología , Ritmo Circadiano , Depresión/psicología , Sueños/fisiología , Emociones/fisiología , Ejercicio Físico/fisiología , Humanos , Masculino , Periodicidad , Factores de Tiempo
9.
Br J Radiol ; 69(824): 769-73, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8949681

RESUMEN

X-ray machines used for mammography have, until recently, almost exclusively employed molybdenum (Mo) as anode material and filtration. In the UK, the RMI model 232 kVp meter is used extensively for the measurement of kilovoltage on such equipment. This unit is provided with switchable internal calibration only for molybdenum and molybdenum, or tungsten and aluminium, as anode and filtration, respectively. However, rhodium (Rh) has recently been introduced for filtration with either a molybdenum or rhodium anode in mammography equipment but, as yet, calibration facilities are not available for rhodium spectra. In this work, appropriate corrections for readings obtained with the RMI 232 kVp meter are derived for use with rhodium as filtration material with either molybdenum or rhodium anode material. An intercomparison between measurements made with four RMI model 232 kVp meters and nine IGE DMR X-ray sets was undertaken. The reproducibility of the instruments was confirmed and measurements of tube potential made on each of the X-ray sets pooled. Measurements were made from a nominal 25-35 kVp using Mo/Mo, Mo/Rh and Rh/Rh target/filter combinations. Corrections for readings obtained with Mo/Rh and Rh/Rh were produced by comparison with readings obtained with Mo/Mo, assuming stability of tube potential between anodes. The results are compared with data recently produced by the manufacturer of the meter.


Asunto(s)
Filtración/instrumentación , Mamografía/instrumentación , Radioisótopos/normas , Rodio , Calibración/normas , Humanos , Reproducibilidad de los Resultados
10.
J Shoulder Elbow Surg ; 5(1): 1-11, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8919436

RESUMEN

Two hundred ten specimens (420 scapulas) from the Hamann-Todd Osteological Collection at the Cleveland Museum of Natural History were evaluated to determine the influence of age on acromial morphologic condition. Equal numbers of specimens from female and male and black and white subjects were evaluated. The length, width, and anterior thickness of the acromion and the acromial facet of the acromioclavicular joint were measured with digital calipers, examined visually, and evaluated radiographically. Distribution of acromial morphologic types was type I, (flat) 32%, type II (curved), 42%, and type III (hooked), 26%. Analysis of the data revealed no consistent, statistically significant impact of age on morphologic condition. The incidence of os acromiale was 8% (17 of 210), with 7 (41%) of 17 specimens having bilateral involvement. Mean acromial dimensions in men were length = 48.5 mm, width = 19.5 mm, and anterior thickness = 7.7 mm. Mean dimensions in women were length = 40.6 mm, width = 18.4 mm, and thickness = 6.7 mm. Multiple regression analysis revealed no significant changes in any dimension with increasing age. Observation of the acromial facet of the acromioclavicular joint revealed 49% were medially inclined, 48% were vertically inclined, and only 3% were laterally inclined in relationship to the sagittal plane. A statistically significant age-related increase in degenerative changes was noted. Anterior acromial spur formation as determined by visual inspection of the acromion was observed in 7% of specimens from patients younger than 50 years compared with 30% of specimens from patients older than 50 years (p < 0.05). Spur formation on the anterior acromion is an age-dependent process. Acromial morphologic condition as evaluated by outlet radiographs is independent of age and appears to be a primary anatomic characteristic. The variations seen in acromial morphologic condition are not acquired from age-related changes and spur formation and thus contribute to impingement disease independent of and in addition to age-related processes.


Asunto(s)
Acromion/anatomía & histología , Envejecimiento/patología , Articulación Acromioclavicular/anatomía & histología , Articulación Acromioclavicular/patología , Acromion/diagnóstico por imagen , Acromion/patología , Adulto , Factores de Edad , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Análisis de Regresión
11.
Am Surg ; 61(3): 257-9, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7887542

RESUMEN

In patients with right lower quadrant pain, the total white cell count is an unreliable predictor of appendicitis. It has been reported that the lymphocyte count can fall in acute appendicitis. This study was undertaken to investigate whether the neutrophil:lymphocyte ratio is a more sensitive indicator than the total leucocyte count. A retrospective study was performed of patients undergoing appendectomy for suspected appendicitis over a 2-year period. A total of 402 patients were identified; histopathology confirmed appendicitis in 367 (91%). Other significant pathology was found in 13 (3.2%). Twenty-two (5.5%) had a histologically normal appendix and recovered uneventfully with no other diagnosis being made. A total of 298 (79%) patients with appendicitis had an elevated preoperative total white cell count. The neutrophil:lymphocyte ratio was calculated for each patient. Using an upper limit of 3.5:1, it was found that 324 (88%) of patients with appendicitis had a ratio equal to or greater than this value. This was significantly different from the proportion with a raised total leucocyte count (P = 0.001). We suggest that the simple calculation of the neutrophil:lymphocyte ratio may provide a parameter that is more sensitive than the total leucocyte count in the prediction of appendicitis.


Asunto(s)
Apendicitis/diagnóstico , Recuento de Leucocitos , Recuento de Linfocitos , Neutrófilos , Enfermedad Aguda , Femenino , Humanos , Masculino , Estudios Retrospectivos , Sensibilidad y Especificidad
12.
Ann R Coll Surg Engl ; 77(1): 7-11, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7717652

RESUMEN

We employed 3D reconstruction of CT images for evaluation of hepatic injuries in a series of eight trauma patients. One had additional reconstruction of a renal injury. 3D imaging provided precise anatomical delineation of damaged areas, particularly in relation to major vessels. Moreover, the imaging agreed with operative findings in every case. The 3D reconstruction facilitated decisions regarding intraoperative, reoperative and non-operative management. The improved imaging provided by 3D reconstruction may allow hepatic CT scans to be interpreted with greater ease and accuracy than conventional CT. We believe this is the first report of its use in liver trauma. Current indications may include postoperative confirmation of the extent of hepatic injuries, assessment before reoperation, and contribution to decisions regarding non-operative management. A limitation at present is the time taken for image production, but we suggest that in the future 3D imaging might contribute to evaluation before emergency surgery in patients with abdominal injuries.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Hígado/diagnóstico por imagen , Hígado/lesiones , Tomografía Computarizada por Rayos X/métodos , Accidentes de Tránsito , Adolescente , Adulto , Niño , Femenino , Venas Hepáticas/diagnóstico por imagen , Humanos , Hígado/cirugía , Masculino , Persona de Mediana Edad , Vena Porta/diagnóstico por imagen , Periodo Posoperatorio , Heridas por Arma de Fuego/diagnóstico por imagen , Heridas por Arma de Fuego/cirugía , Heridas no Penetrantes/diagnóstico por imagen , Heridas no Penetrantes/cirugía
14.
Eur J Vasc Surg ; 5(6): 665-8, 1991 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1756883

RESUMEN

This study examined the necessity for an intensive care environment after abdominal aortic surgery. The detailed records of 45 consecutive patients were reviewed for the first 48 h after operation, recording the occurrence and numbers of episodes of defined medical events or prescription of non-routine drugs. Medical events were hypertension (greater than 200 mmHg), hypotension (less than 100 mmHg), obliguria (less than 20 ml/h) and pulmonary problems. Thirty-six patients (80%) had medical events (hypertension 20, hypotension 17, oliguria 31, hypoxia 10, chest complications 12), and 38 (84%) had medical interventions. Only two had no events or interventions. Twenty-seven (59%) had more than one episode of a medical event which would not have been predicated from their preoperative state. There were three deaths (mortality 6.7%). These results support the case for intensive monitoring and immediate access to experienced medical advice for these patients. In hospitals where the intensive care unit is the best place to provide these facilities, elective operation may need to be deferred if an intensive care bed is not available.


Asunto(s)
Aorta Abdominal/cirugía , Cuidados Críticos , Cuidados Posoperatorios , Anciano , Anciano de 80 o más Años , Aneurisma de la Aorta/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias
16.
Circulation ; 81(2): 548-55, 1990 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1967558

RESUMEN

Data concerning the time of onset of myocardial infarction were obtained for 540 of the 544 patients with creatinine kinase (CK)-MB-confirmed non-Q wave myocardial infarction enrolled in the multicenter Diltiazem Reinfarction Study. Data were also collected for 627 patients who were screened but excluded. Among the 1,167 patients, no diurnal pattern of onset could be found at either 2- or 6-hour intervals. Among the 540 patients enrolled in the trial, no pattern could be found at these intervals either, although at 8-hour intervals, 27% of infarctions occurred between midnight and 8:00 AM, compared with 37% between 8:00 AM and 4:00 PM and 36% between 4:00 PM and 12:00 AM (p = 0.02). In contrast to the patterns previously noted for Q wave myocardial infarction, there was no preponderance of non-Q wave infarction in the late morning. Circadian rhythm was also absent among patients not treated with beta-blockers as well as among patients presenting with ST segment elevation on their enrollment electrocardiograms. Diabetics, women, and patients with first infarction were more likely to present during the afternoon hours. We conclude that the late morning preponderance seen for Q-wave myocardial infarction is not discernable in patients with non-Q wave myocardial infarction. This observation suggests that the pathogenesis of these two infarct subtypes is different or that the process of thrombotic coronary occlusion in Q wave infarction (sustained) differs from that in non-Q wave infarction (nonsustained).


Asunto(s)
Ritmo Circadiano/fisiología , Infarto del Miocardio/etiología , Antagonistas Adrenérgicos beta/uso terapéutico , Creatina Quinasa/análisis , Complicaciones de la Diabetes , Electrocardiografía , Femenino , Humanos , Isoenzimas , Masculino , Estudios Multicéntricos como Asunto , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/fisiopatología , Estudios Prospectivos , Factores de Tiempo
17.
J Xray Sci Technol ; 1(2): 162-70, 1989 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-21307409

RESUMEN

A crystal spectrometer with a photodiode array (PDA) detector was tested for a range of x-ray energies between 1 and 2 keV. A laser-produced plasma has been used as an x-ray source and was generated by the high-power (Vulcan) glass laser system at the SERC Rutherford Appleton Laboratory, UK. The performance of the array was directly compared with the response of Kodak DEF x-ray film. In order to compare quantitatively the performances of the PDA and the film, detective quantum efficiency (DQE) considerations are presented for both devices. It is demonstrated that the PDA has a useful dynamic range which is approximately seven times greater than that of film, a peak DQE of approximately six times that of film, and a greatly superior low-signal performance. The operational characteristics of the PDA are discussed.

18.
J Heart Transplant ; 6(1): 34-43, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3112344

RESUMEN

Though successfully transplanted hearts respond in such a way that individuals remain remarkably asymptomatic, they do not function normally. Characterization of early hemodynamic patterns and their evolvement has not been done. The evolution of hemodynamic indices in 20 patients receiving orthotopic heart (n = 17) or combined heart-lung (n = 3) transplants is therefore documented. In 15 isolated heart recipients, right heart catheterization was performed at 24 to 48 hours, 1 to 2 weeks, 4 to 8 weeks, and greater than 3 months after surgery at the time of routine endomyocardial biopsy. Early, patients had elevated mean blood pressure (96 +/- 14 mm Hg, mean +/- standard deviation), mean right atrial pressure (15 +/- 6 mm Hg), right ventricular end-diastolic pressure (16 +/- 7 mm Hg), mean pulmonary artery pressure (30 +/- 7 mm Hg), and mean pulmonary capillary wedge pressure (19 +/- 6 mm Hg), but normal resting heart rate (96 +/- 14 beats/min) and cardiac output (5.6 +/- 1.6 L/min). Heart rate, blood pressure, and output did not change during follow-up, but right atrial pressure decreased dramatically (4 +/- 2 mm Hg at 3 months), as did right ventricular end-diastolic pressure (4 +/- 4 mm Hg), mean pulmonary artery pressure (21 +/- 8 mm Hg), and pulmonary capillary wedge pressure (11 +/- 4 mm Hg). Analysis of right heart filling dynamics revealed an abnormal inspiratory rise in mean right atrial pressure (15 +/- 6 and 27 +/- 7 mm Hg at 24 to 48 hours) that subsequently resolved. In eight patients whose resting follow-up right heart pressures normalized, rapid volume challenge uncovered occult restrictive right atrial pressure patterns that increased from 4 +/- 4 to 9 +/- 4 mm Hg after infusion of saline solution. Kussmaul's response was not apparent with prevolume infusion, but volume expansion caused appearance of this hemodynamic pattern. All patients had early evidence of tricuspid insufficiency, but in two patients, the Doppler regurgitant fraction was over 50%. These two individuals had hemodynamics similar to the other 15 patients initially, but in contrast, their right heart filling pressures did not change during follow-up. Other significant echocardiographic findings included enlarged atria and increased left ventricular mass in all patients. In two of three combined heart-lung transplant patients, similar hemodynamic patterns were evident. Rejection indices did not correlate with hemodynamic observations. Thus a characteristic evolvement of hemodynamics in heart and heart-lung transplants that mimic dynamics associated with restrictive myocardial disease is documented.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Trasplante de Corazón , Trasplante de Corazón-Pulmón , Hemodinámica , Trasplante de Pulmón , Adolescente , Adulto , Niño , Estudios de Seguimiento , Corazón/fisiología , Humanos , Pulmón/fisiología , Persona de Mediana Edad
20.
Hear Res ; 7(2): 161-9, 1982 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6179918

RESUMEN

Techniques have been developed for recording from and staining cells in the organ of Corti of the Mongolian gerbil. Using physiological criteria as in the guinea pig, the cells were classified as either supporting cells or inner hair cells (IHCs). In addition, several IHCs were stained using HRP and identified in surface preparations. Extracellular responses in the vicinity of IHCs were tuned as sharply as auditory-nerve fibers. Intracellular tuning curves of IHCs were equally sharp near their tips. However, the tip-to-tail distances and sensitivities appeared to be somewhat reduced, presumably due to trauma caused by the recording electrode. Intensity functions, relating receptor depolarization to stimulus intensity level, were obtained for the IHCs. The functions have a consistent quantitative form for frequencies equal to or less than the characteristic frequency of a cell. At low stimulus levels the response increases in proportion to energy, i.e. the square of the sound pressure level. At high levels the response increases more slowly, but shows a greater operating range, and smaller effects of saturation, than do the steady-state responses of single auditory-nerve fibers.


Asunto(s)
Gerbillinae/fisiología , Órgano Espiral/fisiología , Animales , Potenciales Microfónicos de la Cóclea , Células Ciliadas Auditivas/fisiología , Células Ciliadas Auditivas/ultraestructura , Células Ciliadas Auditivas Internas/fisiología , Microelectrodos , Órgano Espiral/citología , Coloración y Etiquetado
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