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1.
J Environ Qual ; 47(4): 654-662, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30025045

RESUMEN

Understanding how agricultural management and climate change affect soil organic carbon (SOC) stocks is particularly important for dryland agriculture regions that have been losing SOC over time due to fallow and tillage practices, and it can lead to development of agricultural practice(s) that reduce the impact of climate change on crop production. The objectives of this study were: (i) to simulate SOC dynamics in the top 30 cm of soil during a 20-yr (1993-2012) field study using CQESTR, a process-based C model; (ii) to predict the impact of changes in management, crop production, and climate change from 2013 to 2032; and (iii) to identify the best dryland cropping systems to maintain or increase SOC stocks under projected climate change in central North Dakota. Intensifying crop rotations was predicted to have a greater impact on SOC stocks than tillage (minimum tillage [MT], no-till [NT]) during 2013 to 2032, as SOC was highly correlated to biomass input ( = 0.91, = 0.00053). Converting from a MT spring wheat (SW, L.)-fallow rotation to a NT continuous SW rotation increased annualized biomass additions by 2.77 Mg ha (82%) and SOC by 0.22 Mg C ha yr. Under the assumption that crop production will stay at the 1993 to 2012 average, climate change is predicted to have a minor impact on SOC (approximately -6.5%) relative to crop rotation management. The CQESTR model predicted that the addition of another SW or rye ( L.) crop would have a greater effect on SOC stocks (0- to 30-cm depth) than conversion from MT to NT or climate change from 2013 to 2032.


Asunto(s)
Carbono , Cambio Climático , Producción de Cultivos , Suelo/química , Agricultura , Productos Agrícolas , North Dakota
2.
Cryo Letters ; 38(6): 419-427, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29734437

RESUMEN

  BACKGROUND: Maintenance of in vitro collections of ulluco (Ullucus tuberosus Cal.) is cumbersome and costly in an ex-situ genebank. An alternative method for long term preservation which is safe and cost-effective is required. OBJECTIVE: To apply a novel cryopreservation procedure using the cryo-plate system to improve the long-term conservation of ulluco. MATERIALS AND METHODS: Initially V and D cryo-plate methods were tested, subsequently the D cryo-plate method was selected for ulluco cryopreservation. The D cryo-plate procedures were optimized for post-LN regrowth procedures including cold-hardening, sucrose addition in alginate gel, and duration of LS treatment. Optimized procedures were tested with 11 ulluco lines. RESULTS: Shoot tips were isolated from cold-hardened shoots for 3-4 weeks at 5 degree C were excised to 1.0-1.5 mm long and 0.5 mm wide and precultured for 16h at 25 degree C on MS with 0.3 M sucrose. The shoot tips were attached on the cryo-plates by alginate gel with 0.4M sucrose. The cryo-plates with attached shoot tips were treated with 2.0 M glycerol and 1.0 M sucrose solution for 90 min at 25 degree C and dehydrated on filter paper in a Petri dish by air current flow at 25 degree C for 45 min before direct immersion in LN. This optimized procedure was applied to shoot tips of 11 ulluco lines, resulting regrowth ranging from 73 % to 97 %, with an average of 90 % post-LN regrowth. CONCLUSION: D cryo-plate is a practical and simple procedure for cryo-storage of in vitro grown ulluco shoot tips in an ex situ genebank.


Asunto(s)
Caryophyllaceae/fisiología , Criopreservación/instrumentación , Criopreservación/métodos , Brotes de la Planta/fisiología , Alginatos/farmacología , Caryophyllaceae/efectos de los fármacos , Frío , Crioprotectores/farmacología , Ácido Glucurónico/farmacología , Glicerol/farmacología , Ácidos Hexurónicos/farmacología , Ósmosis , Brotes de la Planta/efectos de los fármacos , Sacarosa/farmacología , Vitrificación
3.
Int J Sports Med ; 37(8): 614-8, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27176889

RESUMEN

Ischemic preconditioning (IPC) enhances whole-body exercise endurance. However, it is poorly understood whether the beneficial effects originate from systemic (e. g., cardiovascular system) or peripheral (e. g., skeletal muscle) adaptations. The present study examined the effects of IPC on local muscle endurance during fatiguing isometric exercise. 12 male subjects performed sustained isometric unilateral knee-extension exercise at 20% of maximal voluntary contraction until failure. Prior to the exercise, subjects completed IPC or control (CON) treatments. During exercise trial, electromyography activity and near-infrared spectroscopy-derived deoxygenation in skeletal muscle were continuously recorded. Endurance time to task failure was significantly longer in IPC than in CON (mean±SE; 233±9 vs. 198±9 s, P<0.001). Quadriceps electromyography activity was not significantly different between IPC and CON. In contrast, deoxygenation dynamics in the quadriceps vastus lateralis muscle was significantly faster in IPC than in CON (27.1±3.4 vs. 35.0±3.6 s, P<0.01). The present study found that IPC can enhance muscular endurance during fatiguing isometric exercise. Moreover, IPC accelerated muscle deoxygenation dynamics during the exercise. Therefore, we suggest that the origin of beneficial effects of IPC on exercise performance may be the enhanced mitochondrial metabolism in skeletal muscle.


Asunto(s)
Ejercicio Físico/fisiología , Precondicionamiento Isquémico , Resistencia Física/fisiología , Músculo Cuádriceps/fisiología , Electromiografía , Humanos , Contracción Isométrica , Rodilla , Masculino , Fatiga Muscular/fisiología , Oxígeno/fisiología , Consumo de Oxígeno , Adulto Joven
4.
Horm Metab Res ; 45(3): 231-8, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22972180

RESUMEN

Basal-supported oral therapy (BOT) is often used to treat poorly controlled type 2 diabetes. However, patients sometimes experience nocturnal and early morning hypoglycemia. Thus, maintaining targeted glycemic control by BOT is limited in some patients. We assessed the efficacy and safety of replacing basal insulin by sitagliptin therapy in Japanese type 2 diabetes patients on BOT. Forty-nine subjects were sequentially recruited for the 52-week, prospective, single arm study. Patients on BOT therapy were switched from basal insulin to sitagliptin. The primary endpoint was change in HbA1c in 52 weeks. The secondary endpoints were dropout rate, changes in body weight, frequency of hypoglycemia, and relationship between change in HbA1c and insulin secretion capacity evaluated by glucagon loading test. The average dose of basal insulin was 15.0±8.4 units. Sixteen subjects (31.3%) were dropped because replacement by sitagliptin was less effective for glycemic control. In these subjects, diabetes duration was longer, FPG and HbA1c at baseline were higher, and insulin secretion capacity was lower. Change in HbA1c in 52 weeks was - 4 mmol/mol (95% CI - 5 to - 4 mmol/mol) (p<0.05). Change in body weight was - 0.71 kg (95% CI - 1.42 to - 0.004 kg) (p<0.05). Frequency of hypoglycemia was decreased from 1.21±1.05 to 0.06±0.24 times/month. HbA1c level was improved if C-peptide index (CPI) was over 1.19. In conclusion, basal insulin in BOT can be replaced by sitagliptin with a decrease in HbA1c level and frequency of hypoglycemia in cases where insulin secretion capacity was sufficiently preserved.


Asunto(s)
Pueblo Asiatico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Insulina/efectos adversos , Insulina/uso terapéutico , Pirazinas/efectos adversos , Pirazinas/uso terapéutico , Triazoles/efectos adversos , Triazoles/uso terapéutico , Anciano , Índice de Masa Corporal , Peso Corporal/efectos de los fármacos , Péptido C/sangre , Demografía , Diabetes Mellitus Tipo 2/complicaciones , Relación Dosis-Respuesta a Droga , Femenino , Hemoglobina Glucada/metabolismo , Humanos , Hipoglucemia/complicaciones , Hipoglucemia/tratamiento farmacológico , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/efectos adversos , Hipoglucemiantes/farmacología , Insulina/administración & dosificación , Insulina/farmacología , Japón , Masculino , Pirazinas/administración & dosificación , Pirazinas/farmacología , Curva ROC , Fosfato de Sitagliptina , Resultado del Tratamiento , Triazoles/administración & dosificación , Triazoles/farmacología
5.
Int J Clin Pract ; 66(5): 465-76, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22512606

RESUMEN

AIMS: To assess the efficacy and safety of combination therapy with sitagliptin and low dosage sulphonylureas on glycaemic control and insulin secretion capacity in Japanese type 2 diabetes. METHODS: Eighty-two subjects were sequentially recruited for the 52-week, prospective, single arm study. Sitagliptin was added on to sulphonylureas (glimepride or gliclazide) with or without metformin. The primary endpoint was a change in A1C. The secondary endpoints were changes in BMI, insulin secretion capacity, blood pressure and urinary albumin excretion, unresponsive rate, and hypoglycaemia. Insulin secretion capacity was evaluated by glucagon loading test. RESULTS: Change in A1C was -0.80% (95% CI -0.90 to -0.68) (p < 0.001). Change in BMI, systemic and diastolic blood pressure, and urinary albumin excretion were -0.38 kg/m(2) (95% CI -0.72 to -0.04) (p < 0.05), -6.7/-3.6 mmHg (95% CI -10.0 to -3.4/-4.8 to -2.4) (p < 0.001), and -43.2 mg/gCr (95% CI -65.7 to -20.8) (p < 0.001) respectively. Mild hypoglycaemia was observed in three cases. The unresponsive rate was 6.1%. Glucagon loading test showed that 0-min and 6-min CPR at baseline and 52-week were not significantly changed: 0-min CPR, 1.58 ± 0.58-1.71 ± 0.73 ng/ml; 6-min CPR, 3.48 ± 1.47-3.58 ± 1.21 ng/ml. Insulin secretion capacity, CPI and SUIT index at baseline did not predict the efficacy of the combination therapy. The final dosages of glimepiride and gliclazide were 1.44 ± 0.90 mg and 34.5 ± 15.3 mg respectively. The dosage of sitagliptin was increased from 50 mg to 69.0 ± 24.5 mg in 52-week. CONCLUSIONS: The combination therapy with sitagliptin and low dosage sulphonylureas was safe and effective for glycaemic control. Glucagon loading test indicated that 1 year administration of sitagliptin and sulphonylureas preserved insulin secretion capacity.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/administración & dosificación , Pirazinas/administración & dosificación , Compuestos de Sulfonilurea/administración & dosificación , Triazoles/administración & dosificación , Anciano , Albuminuria/etiología , Glucemia/metabolismo , Presión Sanguínea/fisiología , Índice de Masa Corporal , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatología , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Femenino , Hemoglobina Glucada/metabolismo , Humanos , Hipoglucemia/inducido químicamente , Hipoglucemiantes/efectos adversos , Insulina/metabolismo , Secreción de Insulina , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Pirazinas/efectos adversos , Fosfato de Sitagliptina , Compuestos de Sulfonilurea/efectos adversos , Resultado del Tratamiento , Triazoles/efectos adversos
6.
J Neonatal Perinatal Med ; 15(3): 643-651, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35661024

RESUMEN

BACKGROUND: Late preterm infants are at high risk for medical complications and represent a growing NICU population. While 34-weeks' gestation infants are generally admitted to the NICU and 36-weeks'gestation infants stay in mother-baby, there is wide practice variation for 35-weeks'gestation infants. The objective of this study was to compare short-term outcomes of 35-weeks' gestation infants born at two hospitals within the same health system (DUHS), where one (DRH) admits all 35-weeks' gestation infants to their level II NICU and the other (DUH) admits all 35-weeks' gestation infants to mother-baby, unless clinical concern. METHODS: We conducted a retrospective cohort analysis of 35-weeks' gestation infants born at DUHS from 2014-2019. Infant specific data were collected for birth, demographics, medications, medical therapies, LOS, ED visits and readmissions. 35-weeks' gestation infants at each hospital (DRH vs DUH) that met inclusion criteria were compared, regardless of unit(s) of care. RESULTS: 726 infants of 35-weeks' gestation were identified, 591 met our inclusion criteria (DUH -462, DRH -129). Infants discharged from DRH were more likely to receive medical therapies (caffeine, antibiotics, blood culture, phototherapy, NGT), had a 4 day longer LOS, but were more likely to feed exclusively MBM at discharge. There were no differences in ED visits; however, more infants from DUH were readmitted within 30 days of discharge. CONCLUSIONS: Our findings suggest admitting 35-weeks' gestation infants directly to the NICU increases medical interventions and LOS, but might reduce hospital readmissions.


Asunto(s)
Recien Nacido Prematuro , Unidades de Cuidado Intensivo Neonatal , Femenino , Edad Gestacional , Humanos , Lactante , Recién Nacido , Madres , Embarazo , Estudios Retrospectivos
7.
Rev Sci Instrum ; 93(6): 063505, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35778032

RESUMEN

The shock ignition (SI) approach to inertial confinement fusion is a promising scheme for achieving energy production by nuclear fusion. SI relies on using a high intensity laser pulse (≈1016 W/cm2, with a duration of several hundred ps) at the end of the fuel compression stage. However, during laser-plasma interaction (LPI), several parametric instabilities, such as stimulated Raman scattering and two plasmon decay, nonlinearly generate hot electrons (HEs). The whole behavior of HE under SI conditions, including their generation, transport, and final absorption, is still unclear and needs further experimental investigation. This paper focuses on the development of an experimental platform for SI-related experiments, which simultaneously makes use of multiple diagnostics to characterize LPI and HE generation, transport, and energy deposition. Such diagnostics include optical spectrometers, streaked optical shadowgraph, an x-ray pinhole camera, a two-dimensional x-ray imager, a Cu Kα line spectrometer, two hot-electron spectrometers, a hard x-ray (bremsstrahlung) detector, and a streaked optical pyrometer. Diagnostics successfully operated simultaneously in single-shot mode, revealing the features of HEs under SI-relevant conditions.

8.
Nanotechnology ; 20(2): 025703, 2009 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-19417284

RESUMEN

Nanoisland films prepared by annealing thin gold films at high temperatures were imaged using scanning electron microscopy (SEM) and atomic force microscopy, and optically characterized through absorption spectroscopy. Thin gold films of effective thicknesses 2, 5 and 7 nm annealed at 500, 700 and 900 degrees C were fabricated and studied experimentally. The measured absorption characteristics in support of theoretical calculations showed that the shapes of gold islands were partial spheres. The position of the peak absorption wavelength measured with s-polarized light or at normal incidence confirmed that the island shape grew from a near-hemisphere towards a sphere with increasing annealing temperature. The SEM images confirmed that the size of islands increased from 15 nm in diameter to 40 nm in diameter as film thickness increased from 2 to 5 nm. The affect of the index of the substrate material on absorption characteristics were also studied by comparing the absorption spectra of gold island films on quartz and LaSF15 glass substrates. The use of gold nanoisland films for preparing localized surface plasmon resonance substrates was suggested as they held advantages over the gold colloid films.

9.
Kyobu Geka ; 61(6): 433-6; discussion 437-9, 2008 Jun.
Artículo en Japonés | MEDLINE | ID: mdl-18536288

RESUMEN

Recent technological advances have enabled the miniaturization of catheters for coronary angiography and intervention. As a result of this advancement, the transradial approach is becoming more popular. The advantages of this approach include a lower incidence of access site complications, earlier patient ambulation, improved patient satisfaction, and lower cost. The cardiologists of our institute have introduced this technique without delay and have taken the initiative in Japan. However, there are concerns regarding the effect of transradial cardiac catheterization on the condition of radial artery grafts for coronary artery bypass grafting (CABG). In this study, we evaluated the influence of transradial catheterization on CABG. We retrospectively evaluated 157 patients who had undergone CABG using the radial artery. The condition of the grafts was assessed intraoperatively. Postoperative coronary angiography was carried out 3 months after the surgical intervention. The patency of the grafts was assessed by 2 cardiologists. One-quarter of the radial artery grafts were affected by transradial catheterization. Since most of them were located only at the puncture site, the graft itself was capable of being used for grafting after the resection of its affected distal end. The patency rate was not affected by transradial catheterization.


Asunto(s)
Cateterismo Cardíaco/efectos adversos , Cateterismo Cardíaco/métodos , Puente de Arteria Coronaria/métodos , Arteria Radial , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Persona de Mediana Edad , Arteria Radial/patología , Arteria Radial/trasplante , Esclerosis , Grado de Desobstrucción Vascular
10.
J Clin Invest ; 85(2): 345-50, 1990 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1688882

RESUMEN

The maturation of the neuromodulatory action of substance P (SP) was investigated in tracheal smooth muscle (TSM) segments isolated from rabbits aged 2-24 wk. The tissues were placed in baths containing Krebs-Ringer solution and contracted with electrical field stimulation (ES) with ES frequencies ranging from 1 to 75 Hz. In tissues greater than 1 mo of age, the ES frequency-response relationships were progressively shifted in the presence of a maximally effective neuromodulatory SP dose (10(-7) M) such that by 24 wk of age the mean (+/- SEM) maximal tension (Tmax) significantly increased from 380.4 (+/- 41.9) to 502.3 (+/- 64.2) g/g TSM, and the corresponding mean (+/- SEM) log ES frequency producing 50% of Tmax (log ES50) significantly decreased from 1.209 (+/- 0.069) to 1.055 (+/- 0.046) Hz. By contrast, relative to methacholine, the direct contractile effects of SP did not significantly vary with age. In further analyzing the basis for the above age-related difference in the neuromodulatory action of SP, we found that the magnitude of SP-induced neuromodulation was highly correlated to the tissue's intrinsic sensitivity to ES. Indeed, after accounting for the tissue's sensitivity to ES, the effect of age alone on the magnitude of SP-induced neuromodulation was not statistically significant. These findings provide new evidence that: (a) SP-induced neuromodulation of acetylcholine release at the airway neuromuscular junction is significantly enhanced during postnatal development; and (b) that the latter age-dependent action of SP is based on a close coupling of the magnitude of SP-induced neuromodulation to the tissue's intrinsic sensitivity to neurally mediated contraction.


Asunto(s)
Neurotransmisores/farmacología , Sustancia P/farmacología , Tráquea/efectos de los fármacos , Factores de Edad , Animales , Estimulación Eléctrica , Técnicas In Vitro , Contracción Muscular/efectos de los fármacos , Conejos , Sustancia P/antagonistas & inhibidores , Tetrodotoxina/farmacología , Tráquea/fisiología
11.
Lab Chip ; 17(8): 1481-1486, 2017 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-28301613

RESUMEN

This paper presents the formation of complex cross-sectional microfibers using three-dimensional microfluidic devices. The compartments and shapes of core and shell layers in the microfibers were independently controlled via three-dimensional fluidic channels fabricated by the combination of sheath units. The number of layers is easily expanded by the stacking of these units. Therefore, the highly heterogeneous microfibers of alginate hydrogel are obtained in polydimethylsiloxane structures. This widely expandable method has great potential for the development of functional and complex fiber-shaped materials.

12.
J Perinatol ; 36(12): 1128-1131, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27583389

RESUMEN

OBJECTIVE: Health-care leaders place significant focus on reducing the average length of stay (ALOS). We examined the relationships among ALOS, cost and clinical outcomes using a neonatal intensive care unit (NICU) simulation model. STUDY DESIGN: A discrete-event NICU simulation model based on the Duke NICU was created. To identify the relationships among ALOS, cost and clinical outcomes, we replaced the standard probability distributions with composite distributions representing the best and worst outcomes published by the National Institutes of Health Neonatal Research Network. RESULT: Both average cost per patient and average cost per ⩽28 week patient were lower in the best NICU ($16,400 vs $19,700 and $56,800 vs $76,700, respectively), while LOS remained higher (27 vs 24 days). CONCLUSION: Our model demonstrates that reducing LOS does not uniformly reduce hospital resource utilization. These results suggest that health-care leaders should not simply rely on initiatives to reduce LOS without clear line-of-sight on clinical outcomes as well.


Asunto(s)
Unidades de Cuidado Intensivo Neonatal/economía , Tiempo de Internación/economía , Evaluación de Procesos y Resultados en Atención de Salud/economía , Entrenamiento Simulado , Costos de Hospital/estadística & datos numéricos , Humanos , Recién Nacido
13.
Braz J Med Biol Res ; 49(10): e5294, 2016 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-27580004

RESUMEN

Determination of left ventricular ejection fraction (LVEF) using in vivo imaging is the cardiac functional parameter most frequently employed in preclinical research. However, there is considerable conflict regarding the effects of anesthetic agents on LVEF. This study aimed at assessing the effects of various anesthetic agents on LVEF in hamsters using transthoracic echocardiography. Twelve female hamsters were submitted to echocardiography imaging separated by 1-week intervals under the following conditions: 1) conscious animals, 2) animals anesthetized with isoflurane (inhaled ISO, 3 L/min), 3) animals anesthetized with thiopental (TP, 50 mg/kg, intraperitoneal), and 4) animals anesthetized with 100 mg/kg ketamine plus 10 mg/kg xylazine injected intramuscularly (K/X). LVEF obtained under the effect of anesthetics (ISO=62.2±3.1%, TP=66.2±2.7% and K/X=75.8±1.6%) was significantly lower than that obtained in conscious animals (87.5±1.7%, P<0.0001). The K/X combination elicited significantly higher LVEF values compared to ISO (P<0.001) and TP (P<0.05). K/X was associated with a lower dispersion of individual LVEF values compared to the other anesthetics. Under K/X, the left ventricular end diastolic diameter (LVdD) was increased (0.60±0.01 cm) compared to conscious animals (0.41±0.02 cm), ISO (0.51±0.02 cm), and TP (0.55±0.01 cm), P<0.0001. The heart rate observed with K/X was significantly lower than in the remaining conditions. These results indicate that the K/X combination may be the best anesthetic option for the in vivo assessment of cardiac systolic function in hamsters, being associated with a lower LVEF reduction compared to the other agents and showing values closer to those of conscious animals with a lower dispersion of results.


Asunto(s)
Anestésicos/farmacología , Volumen Sistólico/efectos de los fármacos , Función Ventricular Izquierda/efectos de los fármacos , Animales , Combinación de Medicamentos , Ecocardiografía/métodos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/efectos de los fármacos , Isoflurano/farmacología , Ketamina/farmacología , Mesocricetus , Valores de Referencia , Sístole/efectos de los fármacos , Tiopental/farmacología , Factores de Tiempo , Xilazina/farmacología
14.
J Comp Neurol ; 192(2): 247-63, 1980 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-7400398

RESUMEN

The adult and developmental morphology of spiny and aspiny neurons in the dog caudate nucleus was examined using the Golgi-Kopsch technique. In the adult, three types each of spiny and aspiny neurons were identified based upon dendritic morphology and cell soma size. They corresponded in large part to those neurons described previously in the caudate nuclei of the rat, cat, and monkey. At birth, dendrites of spiny neurons possessed varicosities, filopodia, and thick proximal dendritic stumps--all characteristic of immaturity. Maturation of these processes involved the thinning of proximal dendrites, lengthening of dendritic shafts, and growth of dendritic spines. Although most of the dendritic maturation occurred during the first postnatal month, spine densities and dendritic lengths of spiny I neurons at 30 days were still less than those seen in the adult. Aspiny I neurons were also immature at birth but lacked the filopodia and thicker proximal dendrites that characterized immature spiny neurons. Aspiny dendritic development involved primarily the lengthening of dendritic processes; by 30 days the aspiny I neurons were indistinguishable from those seen in the adult. These results suggest that dendritic development of spiny I neurons may extend well past the end of the first postnatal month and that studies investigating functional development in the caudate nucleus should consider the relatively extended time period required for maturation of these primary synaptic sites.


Asunto(s)
Envejecimiento , Núcleo Caudado/citología , Dendritas/ultraestructura , Animales , Diferenciación Celular , Perros , Neuronas/clasificación , Neuronas/citología
15.
J Comp Neurol ; 261(1): 48-73, 1987 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-2442202

RESUMEN

The cytoarchitecture and neostriatal projections of the canine prefrontal cortex (PFC) were examined by using Nissl, silver degeneration, autoradiographic, and horseradish peroxidase techniques. Cytoarchitectonically, the PFC can be divided into six major gyral areas with each area corresponding to one of the major gyri--proreal, polar, pregenual, subproreal, paraorbital, and orbital--defined myeloarchitectonically by Kreiner (J. Comp. Neurol. 116:117-133, '61). Of the six major areas, only the proreal gyrus displays a distinctly granular layer IV. In all other gyri, layer IV is more difficult to distinguish. In both the orbital and polar gyri, layer IV is poorly defined and consists of scattered clusters of small cells between layers III and V. In the pregenual, subproreal, and paraorbital gyri, layer IV is not detectable. In all gyri, layer V consists of a thin lamina of small and medium-size pyramidal cells. The transition from layer III to layer V is marked by changes in cell density and size as well as staining intensity. Borders between layers V and VI are generally less distinct than those between layers III and V, with the exception of the pregenual gyrus, in which layer V is separated from layer VI by a distinct cell-poor lamina. In the subproreal and paraorbital gyri, the border between the underlying white matter and layer VI is particularly distinct, with large numbers of neurons oriented tangentially to the white matter. In contrast, the border between layer VI of the orbital gyrus and the white matter is less distinct and consists of palisades of neurons extending well into the white matter. The silver degeneration and autoradiographic methods revealed that prefrontostriatal projections terminate as dorsoventrally oriented longitudinal bands within the medial half of the head and body of the caudate nucleus. Projections from the polar and dorsal proreal gyri terminate most medially in the nucleus while projections from the lateral part of the proreal, subproreal, orbital, and paraorbital gyri terminate progressively more laterally within the medial half of the nucleus. There is apparent overlap between adjacent projection fields. A sparse projection was also noted to a small part of the putamen adjacent to the internal capsule. Injections of horseradish peroxidase into the medial and ventromedial parts of the head of the caudate nucleus resulted in widespread retrograde labeling in parts of the proreal, pregenual, paraorbital, subproreal, and central precruciate gyri. Labeled neurons were located primarily in the superficial part of layer V with smaller numbers of labeled cells in layers III, IV, and VI.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Núcleo Caudado/anatomía & histología , Perros/anatomía & histología , Lóbulo Frontal/anatomía & histología , Putamen/anatomía & histología , Aminoácidos , Animales , Autorradiografía , Femenino , Peroxidasa de Rábano Silvestre , Masculino , Vías Nerviosas/anatomía & histología , Aglutinina del Germen de Trigo-Peroxidasa de Rábano Silvestre Conjugada , Aglutininas del Germen de Trigo
16.
J Comp Neurol ; 277(4): 529-40, 1988 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-2463291

RESUMEN

Choline acetyltransferase (ChAT) immunocytochemistry and lectin-conjugated horseradish peroxidase (WGA-HRP) histochemistry were combined at the electron microscopic level to examine the morphology of cholinergic terminals in the canine centrum medianum-parafascicular complex (CM-Pf) and to localize cholinergic terminals making synaptic contact with retrogradely labeled CM-Pf thalamostriatal projection neurons. Following WGA-HRP injections into the caudate nucleus, CM-Pf neurons were heavily labeled with WGA-HRP reaction product. Examination with the electron microscope revealed retrogradely labeled neurons characterized by a large nucleus with deep infoldings of the nuclear envelope. ChAT-positive terminals were observed arising from small-diameter nonmyelinated axonal profiles. These terminals varied in size from 0.5 to 1.4 micron in long diameter. The smaller terminals (0.5-0.7 micron) were seen most frequently and established symmetrical or slightly asymmetrical synaptic contacts with small dendritic profiles. The larger ChAT-positive terminals (1.0-1.4 micron) were less frequently observed, contained several mitochondria and small clusters of pleomorphic vesicles, and contacted large dendritic shafts and cell somata. Some of the postsynaptic targets of both smaller and larger ChAT-positive terminals were identified as belonging to retrogradely HRP-labeled thalamostriatal neurons. These observations indicate that at least some thalamostriatal neurons within the CM-Pf complex are innervated by cholinergic terminals which probably arise from ChAT-positive cell bodies located within the pontomesencephalic tegmentum, particularly within the nucleus tegmenti pedunculopontinus and the laterodorsal tegmental nucleus. These findings provide evidence for direct influence by cholinergic brainstem nuclei over activities of thalamostriatal neurons.


Asunto(s)
Colina O-Acetiltransferasa/análisis , Fibras Colinérgicas/ultraestructura , Cuerpo Estriado/anatomía & histología , Perros/anatomía & histología , Tálamo/anatomía & histología , Animales , Fibras Colinérgicas/metabolismo , Cuerpo Estriado/ultraestructura , Peroxidasa de Rábano Silvestre , Microscopía Electrónica , Tálamo/ultraestructura , Aglutinina del Germen de Trigo-Peroxidasa de Rábano Silvestre Conjugada , Aglutininas del Germen de Trigo
17.
J Comp Neurol ; 214(1): 17-31, 1983 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-6841673

RESUMEN

Corticothalamic projections from postcruciate area 4, located on the rostral part of the posterior sigmoid gyrus, were traced with the autoradiographic technique in the dog. Injections of tritiated amino acids were made into the lateral and medial parts of area 4 in regions corresponding to the forelimb and hindlimb areas of the primary motor cortex, respectively. In cases with injections placed in the lateral part of area 4, dense accumulations of label were present in the lateral part of the ventral anterior nucleus (VA), the central part of the ventral lateral nucleus (VL), the ventral half of the ventral posterior inferior nucleus (VPI), the caudal part of the central lateral nucleus (CL), and the centrum medianum (CM). Lighter label was also present in the lateral part of the cytoarchitectonically distinct VL region bordering the ventrobasal complex (VB), as well as in the ventrolateral part of the mediodorsal nucleus (MD), and in the lateral posterior nucleus (LP). In one case in which the injection site involved an adjacent part of area 3a, label was also seen ventrally in the medial division of the posterior nuclear group (POm). However, no detectable differences in VL, MD, or intralaminar labeling patterns were noted between this case and the four other cases with injections confined to the lateral part of area 4. In two cases with injections restricted to the medial part of area 4, dense label was present in the lateralmost part of VL, the ventral part of VPI, the caudal part of CL, and CM. Lighter label was also present in the VL region bordering the dorsolateral edge of VB and in LP. An additional case in which the injection also involved the rostral border of area 3a showed a similar pattern of thalamic labeling. Projections from both the lateral and medial parts of area 4 were also noted in the subthalamic nucleus, zona incerta, and nucleus of Darkschewitsch. These results suggest that corticothalamic projections from postcruciate area 4 to VL are organized topographically such that projections from the lateral part of area 4 project centrally within VL while those from the medial part of area 4 project more laterally. Both parts of area 4 also project topographically to a cytoarchitectonically distinct region of VL located immediately adjacent to VB. In contrast, the projections to the intralaminar nuclei do not appear to be topographically organized. The data from cases involving spread of the injection into area 3a suggest that projection patterns from area 3a to ventral, intralaminar, and medial thalamic nuclei are similar to those from area 4. However, it appears that at least the lateral part of area 3a also projects to POm.


Asunto(s)
Corteza Cerebral/anatomía & histología , Núcleos Talámicos/anatomía & histología , Animales , Mapeo Encefálico , Gatos , Perros , Corteza Motora/anatomía & histología , Vías Nerviosas/anatomía & histología , Mapaches , Corteza Somatosensorial/anatomía & histología , Especificidad de la Especie
18.
J Comp Neurol ; 247(1): 56-68, 1986 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-2423563

RESUMEN

Thalamostriatal projections from the ventral anterior nucleus (VA) were mapped by using autoradiographic and horseradish peroxidase techniques in the dog. Injections of tritiated leucine and proline into the lateral, central, and medial parts of VA resulted in anterograde label over the dorsolateral, midlateral, and dorsal parts of the head of the caudate nucleus, respectively. The dorsolateral and midlateral parts of the caudate contained the heaviest label. No silver grains were located over the medial or ventral parts of the caudate. Light to moderate label was located over the most dorsal part of the putamen. After injections of lectin-conjugated horseradish peroxidase (WGA-HRP) into the dorsolateral or intermediate areas of the head of the caudate, retrogradely labeled cells were present in the lateral and central parts of VA, respectively. In cases with dorsolateral caudate injections, labeled cells formed a narrow dorsoventrally oriented band located in the lateral part of VA whereas in the case with a larger injection into midcaudate, large numbers of labeled neurons were scattered throughout the central area of VA. Retrogradely labeled cells were also found in the rostral part of the ventral lateral nucleus (VL). Injections of WGA-HRP into the medial part of the caudate resulted in only a few labeled cells located in the dorsomedial part of VA. Combining these data with those from other studies mapping neostriatal afferents from the cerebral cortex in the dog, it is apparent that the midlateral part of the caudate receiving input from VA also receives afferents from cortical area 6. Furthermore, the dorsolateral part of the caudate that receives input from the lateral part of VA also receives afferents from cortical area 4. These results indicate that the dorsal and lateral parts of the canine caudate nucleus may constitute important links in the transmission and integration of information related to complex motor activities.


Asunto(s)
Mapeo Encefálico , Cuerpo Estriado/anatomía & histología , Núcleos Talámicos/anatomía & histología , Aminoácidos , Animales , Autorradiografía , Perros , Femenino , Peroxidasa de Rábano Silvestre , Lectinas , Masculino , Vías Nerviosas/anatomía & histología , Neuronas/clasificación , Técnicas Estereotáxicas , Aglutinina del Germen de Trigo-Peroxidasa de Rábano Silvestre Conjugada
19.
J Comp Neurol ; 252(4): 446-67, 1986 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-3782511

RESUMEN

The cytoarchitecture and thalamic afferents of cortical area 6 located on the anterior sigmoid gyrus were mapped and analyzed in the dog by means of cytoarchitectonic, horseradish peroxidase (HRP), and autoradiographic methods. Cytoarchitectonically, area 6 consists of medial and lateral subdivisions that correspond, respectively, to areas 6a alpha and 6a beta in the cat. In the dog, area 6a alpha is characterized by a wide layer III, the merging of borders between layers III and V, the presence of small-to-medium-size pyramidal cells in layer V, and a pallisade arrangement of cells in layer VI. Area 6a beta appears more stratified, with a relatively acellular layer present between layers V and VI and the presence of large pyramidal cells in layer V. Neither area 6a alpha nor 6a beta contains a layer IV. Data obtained from injections of HRP into areas 6a alpha or 6a beta revealed that labeled thalamic neurons were distributed in a longitudinal band extending from the rostral part of the ventral anterior nucelus (VA) through the caudal part of the mediodorsal nucleus (MD). Labeled cells were observed in the ventral lateral and ventral medial thalamic nuclei as well as in several of the intralaminar nuclei including the central lateral, central medial, parafascicular, and centrum medianum nuclei. A few labeled cells were also located in the suprageniculate nucleus. The densest thalamic labeling was present in VA and MD following injections into area 6a alpha. Equivalent or even larger injections into area 6a beta resulted in much less thalamic labeling. The band of labeled cells also extended into the hypothalamus, zona incerta, amygdala, claustrum, periaqueductal gray of the midbrain, and the nucleus of Darkschewitsch. Results from autoradiographic experiments showed that area 6 subdivisions receive a loosely organized topographic input from VA. Injections of tritiated amino acids were made into selected regions of VA and into the caudal part of MD, areas in which the largest numbers of HRP-labeled cells were located. Area 6a alpha receives afferents primarily from the rostromedial part of VA and the caudal part of MD while area 6a beta receives its principal input from the caudal and lateral parts of VA with minimal input from MD. Axons originating from VA terminate in both layers I and III of area 6 while those originating from the caudal part of MD terminate only in layer III.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Lóbulo Frontal/anatomía & histología , Núcleos Talámicos/anatomía & histología , Vías Aferentes/anatomía & histología , Animales , Mapeo Encefálico , Gatos , Perros , Movimientos Oculares , Femenino , Lóbulo Frontal/citología , Lóbulo Frontal/fisiología , Masculino , Pupila , Mapaches , Núcleos Talámicos/fisiología
20.
Am J Med ; 94(2): 188-96, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8430714

RESUMEN

BACKGROUND: The value of the history and physical examination in diagnosing chronic obstructive pulmonary disease (COPD) is uncertain. This study was undertaken to determine the best clinical predictors of COPD and to define the incremental changes in the ability to diagnose COPD that occur when the physical examination findings and then the peak flowmeter results are added to the pulmonary history. SUBJECTS AND METHODS: Ninety-two outpatients with a self-reported history of cigarette smoking or COPD completed a pulmonary history questionnaire and received peak flow and spirometric testing. The subjects were independently examined for 12 physical signs by 4 internists blinded to all other results. Multivariate analyses identified independent predictors of clinically significant, moderate COPD, defined as a forced expiratory volume in 1 second (FEV1) less than 60% of the predicted value or a FEV1/FVC (forced vital capacity) less than 60%. RESULTS: Fifteen subjects (16%) had moderate COPD. Two historical variables from the questionnaire--previous diagnosis of COPD and smoking (70 or more pack-years)--significantly entered a logistic regression model that diagnosed COPD with a sensitivity of 40% and a specificity of 100%. Only the physical sign of diminished breath sounds significantly added to the historical model to yield a mean sensitivity of 67% and a mean specificity of 98%. The peak flow result (best cutoff value was less than 200 L/min) significantly added to the models of only one of the four physicians for a mean final sensitivity of 77% and a specificity of 95%. Subjects with none of the three historical and physical variables had a 3% prevalence of COPD; this prevalence was unchanged by adding the peak flow results. CONCLUSIONS: Diminished breath sounds were the best predictor of moderate COPD. A sequential increase in sensitivity and a minimal decrease in specificity occurred when the quality of breath sounds was added first to the medical history, followed by the peak flow result. The chance of COPD was very unlikely with a normal history and physical examination.


Asunto(s)
Enfermedades Pulmonares Obstructivas/diagnóstico , Anamnesis , Examen Físico , Adulto , Diafragma/fisiopatología , Flujo Espiratorio Forzado , Volumen Espiratorio Forzado , Predicción , Humanos , Enfermedades Pulmonares Obstructivas/fisiopatología , Percusión , Ventilación Pulmonar/fisiología , Volumen Residual , Mecánica Respiratoria/fisiología , Ruidos Respiratorios/fisiopatología , Sensibilidad y Especificidad , Fumar , Espirometría , Tórax/fisiopatología , Capacidad Pulmonar Total , Capacidad Vital
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