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1.
J Neurol ; 270(2): 986-994, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36326890

RESUMEN

INTRODUCTION: Although migraine prevalence decreases with aging, some older patients still suffer from chronic migraine (CM). This study aimed to investigate the outcome of OnabotulinumtoxinA (OBT-A) as preventative therapy in elderly CM patients. METHODS: This is a post hoc analysis of real-life prospectively collected data at 16 European headache centers on CM patients treated with OBT-A over the first three treatment cycles (i.e., Cy1-3). We defined: OLD patients aged ≥ 65 years and nonOLD those < 65-year-old. The primary endpoint was the changes in monthly headache days (MHDs) from baseline to Cy 1-3 in OLD compared with nonOLD participants. The secondary endpoints were the responder rate (RR) ≥ 50%, conversion to episodic migraine (EM) and the changes in days with acute medication use (DAMs). RESULTS: In a cohort of 2831 CM patients, 235 were OLD (8.3%, 73.2% females, 69.6 years SD 4.7). MHDs decreased from baseline (24.8 SD 6.2) to Cy-1 (17.5 SD 9.1, p < 0.000001), from Cy-1 to Cy-2 (14.8 SD 9.2, p < 0.0001), and from Cy-2 to Cy-3 (11.9 SD 7.9, p = 0.001). DAMs progressively reduced from baseline (19.2 SD 9.8) to Cy-1 (11.9 SD 8.8, p < 0.00001), to Cy-2 (10.9 SD 8.6, p = 0.012), to Cy-3 (9.6 SD 7.4, p = 0.049). The 50%RR increased from 30.7% (Cy-1) to 34.5% (Cy-2), to 38.7% (Cy-3). The above outcome measures did not differ in OLD compared with nonOLD patients. CONCLUSION: In a population of elderly CM patients with a long history of migraine OBT-A provided a significant benefit, over the first three treatment cycles, as good as in non-old patients.


Asunto(s)
Toxinas Botulínicas Tipo A , Trastornos Migrañosos , Anciano , Femenino , Humanos , Masculino , Toxinas Botulínicas Tipo A/uso terapéutico , Enfermedad Crónica , Trastornos Migrañosos/tratamiento farmacológico , Trastornos Migrañosos/epidemiología , Cefalea/tratamiento farmacológico , Resultado del Tratamiento
2.
Trop Med Int Health ; 19(4): 398-406, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24405627

RESUMEN

OBJECTIVE: We tested whether soap presence in the home or a designated handwashing station was associated with diarrhoea and respiratory illness in Kenya. METHODS: In April 2009, we observed presence of a handwashing station and soap in households participating in a longitudinal health surveillance system in rural Kenya. Diarrhoea and acute respiratory illness (ARI) in children < 5 years old were identified using parent-reported syndromic surveillance collected January-April 2009. We used multivariate generalised linear regression to estimate differences in prevalence of illness between households with and without the presence of soap in the home and a handwashing station. RESULTS: Among 2547 children, prevalence of diarrhoea and ARI was 2.3 and 11.4 days per 100 child-days, respectively. Soap was observed in 97% of households. Children in households with soap had 1.3 fewer days of diarrhoea/100 child-days (95% CI -2.6, -0.1) than children in households without soap. ARI prevalence was not associated with presence of soap. A handwashing station was identified in 1.4% of households and was not associated with a difference in diarrhoea or ARI prevalence. CONCLUSIONS: Soap presence in the home was significantly associated with reduced diarrhoea, but not ARI, in children in rural western Kenya. Whereas most households had soap in the home, almost none had a designated handwashing station, which may prevent handwashing at key times of hand contamination.


Asunto(s)
Diarrea/prevención & control , Desinfección de las Manos/instrumentación , Enfermedades Respiratorias/prevención & control , Jabones/provisión & distribución , Abastecimiento de Agua/estadística & datos numéricos , Enfermedad Aguda , Preescolar , Diarrea/epidemiología , Femenino , Desinfección de las Manos/métodos , Humanos , Lactante , Recién Nacido , Kenia/epidemiología , Modelos Lineales , Masculino , Vigilancia de la Población/métodos , Prevalencia , Características de la Residencia , Enfermedades Respiratorias/epidemiología , Salud Rural
3.
Rofo ; 177(9): 1297-304, 2005 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-16123878

RESUMEN

Due to German regulations, acceptance and consistency tests have to be obtained by 12.31.2005 for all equipment used for computed radiography according to special standards published in DIN 6868. This article familiarizes all users with the most important aspects of these standards. In addition, explanatory and background information for establishing these regulations are provided.


Asunto(s)
Garantía de la Calidad de Atención de Salud , Intensificación de Imagen Radiográfica/normas , Artefactos , Femenino , Alemania , Humanos , Masculino , Mamografía/instrumentación , Mamografía/normas , Intensificación de Imagen Radiográfica/instrumentación , Radiografía Dental/instrumentación , Radiografía Dental/normas , Tecnología Radiológica/instrumentación
4.
Rofo ; 177(8): 1110-5, 2005 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-16021543

RESUMEN

PURPOSE: Evaluation of low-dose full spine radiographs using fluoroscopic images for the assessment of the Cobb angle measurement in patients with scoliosis. MATERIAL AND METHODS: Twenty-one consecutive patients (aged 10 - 27 years, mean age 14 years) with a conventional full spine examination (film speed class 800) underwent a follow-up exam using digital pulsed fluoroscopy (Multi Diagnost 4, Philips Medical Systems, Eindhoven, The Netherlands). The mean follow-up was 9 months. During a synchronized scan with a C-arm speed of 4 cm/sec fluoroscopic images were stored with a pulsed frequency of 3 images per second. The single images were merged and reconstructed to one image with the software Easy Spine (Philips medical Systems, Eindhoven, The Netherlands). The corresponding dose-area product values (DAP) of both methods were compared. Three independent observers assessed Cobb angles and image quality for each technique. RESULTS: The mean DAP values for conventional imaging was 94.9 cGy x cm (2) and for fluoroscopy 7.8 cGy x cm (2), respectively. A significant dose reduction of 91.8 % (CI 91 % to 95 %) was calculated. The average absolute angle difference between the observers was found to be 2.7 degrees for conventional imaging and 2.4 degrees for the fluoroscopic method. Interobserver standard deviation of 2.9 degrees was lower than the 5.3 degrees for conventional images. Image quality was better in the conventional images. CONCLUSION: Using the scanning method, we could achieve a mean reduction of the radiation dose of 92 %, while the accuracy of the Cobb angle measurements was comparable for both techniques despite of reduced image quality of digital fluoroscopy.


Asunto(s)
Fluoroscopía/métodos , Intensificación de Imagen Radiográfica/métodos , Escoliosis/diagnóstico por imagen , Columna Vertebral/diagnóstico por imagen , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Película para Rayos X
5.
Neurogastroenterol Motil ; 16(1): 53-60, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14764205

RESUMEN

We studied the effects of food supplementation with Saccharomyces boulardii (S. boulardii; synonym S. cerevisiae HANSEN CBS 5926; 1 g per day for 9 days) on the presence and co-localization patterns of neuronal markers in myenteric neurones of the pig jejunum. The pan neuronal marker Hu revealed no change in the number of neuronal cell bodies per ganglion (37 +/- 7 in control vs 34 +/- 9 in the S. boulardii group). Ranked by size the following cell populations were identified: choline acetyltransferase (ChAT), calbindin-28k (CALB), substance P (SP), neurofilament 160 kD (NF-160), vasoactive intestinal polypeptide (VIP), nitric oxide synthase (NOS), calcitonin gene-related peptide (CGRP), calretinin (CALRET). We found a significant decrease in the number of CALB myenteric neurones in animals which received S. boulardii supplemented diet. None of the other neuronal markers revealed any difference between controls and S. boulardii treated animals. The study reports transmitter-localization patterns in the myenteric plexus of the pig jejunum and provides evidence that changes in the neurochemistry of enteric neurones occur with S. boulardii supplemented diet. Although only CALB expression was altered and the functional significance of this finding remains unknown, our study identified a possible new effector level of probiotics in the gut.


Asunto(s)
Plexo Mientérico/microbiología , Plexo Mientérico/fisiología , Neuronas/microbiología , Neuronas/fisiología , Saccharomyces , Animales , Calbindinas , Colina O-Acetiltransferasa/metabolismo , Aditivos Alimentarios/farmacología , Inmunohistoquímica , Yeyuno/microbiología , Yeyuno/fisiología , Neurotransmisores/metabolismo , Técnicas de Cultivo de Órganos , Proteína G de Unión al Calcio S100/metabolismo , Porcinos
6.
AJR Am J Roentgenol ; 181(4): 931-7, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14500204

RESUMEN

OBJECTIVE: The purpose of the study was to examine the possibilities for reducing radiation exposure in uroradiology using digital flat-panel silicon X-ray detector radiography. We compared the subjectively determined image quality of abdominal radiographs and urograms obtained on a digital flat-panel detector radiography system with those obtained on a computed radiography system. SUBJECTS AND METHODS. Fifty patients who had a clinical indication for urography underwent unenhanced abdominal imaging that was alternately performed using flat-panel silicon X-ray detector radiography or computed radiography. For patients who required a second radiograph with contrast medium, the examination modality was changed to avoid exposing the patients to excess radiation. The images obtained on flat-panel X-ray detector radiography were obtained at half the radiation dose of the images obtained on computed radiography (800 speed vs 400 speed). The resulting 50 pairs of images were interpreted by four independent observers who rated the detectability of structures of bone and the efferent urinary tract relevant to diagnosis and compared the image quality. RESULTS: At half the radiation dose, digital flat-panel X-ray detector radiography provided equivalent image quality of the liver and spleen, lumbar vertebrae 2 and 5, pelvis, and psoas margin on abdominal radiographs. The image quality obtained with digital flat-panel X-ray detector radiography of the kidneys, the hollow cavities of the upper efferent urinary tract, and the urinary bladder was judged to be statistically better than those obtained with computed radiography. CONCLUSION: With half the exposure dose of computed radiography, the flat-panel X-ray detector produced urograms with an image quality equivalent to or better than computed radiography.


Asunto(s)
Urografía/métodos , Pantallas Intensificadoras de Rayos X , Diagnóstico por Computador , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Compuestos de Silicona , Micción
7.
Rofo ; 174(5): 625-30, 2002 May.
Artículo en Alemán | MEDLINE | ID: mdl-11997864

RESUMEN

PURPOSE: To evaluate the diagnostic value of digital flat-panel radiography in uroradiology the i. v. urograms of patients who had been examined with computed radiography and digital flat-panel radiography were compared regarding image quality. METHODS: 50 patients who underwent clinically indicated i. v. urography were examined with digital flat-panel radiography and computed radiography. In order to avoid unnecessary double exposure to X-rays, patients were examined either by flat-panel or computed radiography before injection of contrast media. Each further clinically indicated exposure after administration of contrast media was done by alternating the other examination technique. The digital images were compared by 4 radiologists regarding image quality for the detection of defined anatomic structures. RESULTS: Digital flat-panel radiography showed an image quality of the liver, spleen and both kidneys that was similar to computed radiography. The urinary tract, lumbar spine, pelvis and psoas muscle were significantly better visible on flat-panel radiography images. CONCLUSIONS: Compared to computed radiography there is no loss of image information by using digital flat-panel radiography in uroradiology. On the contrary, some anatomic structures on abdominal survey images show better image quality. In conclusion, digital flat-panel radiography has the potential to replace computed radiography in uroradiologic examinations.


Asunto(s)
Diagnóstico por Computador/métodos , Urografía/métodos , Enfermedades Urológicas/diagnóstico por imagen , Medios de Contraste , Humanos , Riñón/diagnóstico por imagen , Hígado/diagnóstico por imagen , Persona de Mediana Edad , Reproducibilidad de los Resultados , Bazo/diagnóstico por imagen
8.
AJR Am J Roentgenol ; 177(6): 1397-403, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11717093

RESUMEN

OBJECTIVE: The purpose of our study was to compare the diagnostic performance of a digital selenium detector (Thoravision) with that of analog film-screen systems and digital luminescence radiography in skeletal radiography for the detection of fissures and lesions in porcine bones. MATERIALS AND METHODS: One hundred bones taken from domestic pigs (50 ribs and 50 femurs) were divided into two equal groups. Fissures and bone lesions were created in 50 bones and 50 served as controls. The bones were examined using film-screen systems, digital luminescence radiography, and digital selenium radiography at various doses. Digital selenium radiography exposure values were adapted to the image geometry differing from the reference methods with a detector focus distance of 2.15 m. Four radiologists independently evaluated image quality and detectability of fissures and lesions on a five-point scale of confidence. Statistical evaluation was based on receiver operating characteristic curve analysis. RESULTS: Fissures and bone lesions were detected most reliably using the mammography film-screen system, but the difference in the results of the analog and digital reference images did not achieve statistical significance. CONCLUSION: Compared with analog film-screen systems, the lower spatial resolution of the digital selenium and digital luminescence radiography systems does not affect detectability of fissures and bone lesions in porcine bone. Selenium is effective in skeletal radiography for detecting fissures and bone lesions. With digital selenium and digital luminescence radiography, the surface dose can be cut to half that required for 200-speed film-screen systems without losing any diagnostically relevant information.


Asunto(s)
Enfermedades Óseas/diagnóstico por imagen , Luminiscencia , Intensificación de Imagen Radiográfica , Selenio , Pantallas Intensificadoras de Rayos X , Animales , Porcinos
9.
Biochemistry ; 40(13): 3796-803, 2001 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-11300759

RESUMEN

Binding of ATP to the catalytic domain of myosin induces a local conformational change which is believed to cause a major rotation of an 8.5 nm alpha-helix that is stabilized by the regulatory and essential light chains. Here we attempt to follow this rotation by measuring the mobility and orientation of a fluorescent probe attached near the C- or N-terminus of essential light chain 1 (LC1). Cysteine 178 of wild-type LC1, or Cys engineered near the N-terminus of mutant LC1, was labeled with tetramethylrhodamine and exchanged into skeletal subfragment-1 (S1) or into striated muscle fibers. In the absence of ATP, the fluorescence anisotropy (r) and the rotational correlation time (rho) of S1 reconstituted with LC1 labeled near the C-terminus were 0.195 and 66.6 ns, respectively. In the presence of ATP, r and rho increased to 0.233 and 233 ns, indicating considerable immobilization of the probe. A related parameter indicating the degree of order of cross-bridges in muscle fibers, Deltar, was small in rigor fibers (-0.009) and increased in relaxed fibers (0.030). For S1 reconstituted with LC1 labeled near the N-terminus, the steady-state anisotropy was 0.168 in rigor, and increased to 0.223 in relaxed state. In fibers, the difference in rigor was large (Deltar = 0.080), because of binding to the thin filaments, and decreased to 0.037 in relaxed fibers. These results suggest that before the power stroke, in the presence of ATP or its products of hydrolysis, the termini of LC1 are immobilized and ordered, and after the stroke, they become more mobile and partially disordered. The results are consistent with crystallographic structures that show that the level of putative stabilizing interactions of LC1 with the heavy chain of S1 in the transition state is reduced as the regulatory domain rotates to its post-power stroke position.


Asunto(s)
Proteínas Motoras Moleculares/química , Proteínas Motoras Moleculares/metabolismo , Cadenas Ligeras de Miosina/química , Cadenas Ligeras de Miosina/metabolismo , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Actinas/metabolismo , Adenosina Trifosfato/metabolismo , Secuencia de Aminoácidos , Animales , Pollos , Polarización de Fluorescencia , Colorantes Fluorescentes/metabolismo , Microscopía Electrónica , Proteínas Motoras Moleculares/ultraestructura , Datos de Secuencia Molecular , Cadenas Ligeras de Miosina/ultraestructura , Subfragmentos de Miosina/metabolismo , Subfragmentos de Miosina/ultraestructura , Fragmentos de Péptidos/ultraestructura , Unión Proteica , Conejos
10.
J Trauma ; 50(2): 213-22, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11242284

RESUMEN

BACKGROUND: In response to inflammation, endothelial cytoskeleton rearrangement, cell contraction, and intercellular gap formation contribute to a loss of capillary barrier integrity and resultant interstitial edema formation. The intracellular signals controlling these events are thought to be dependent on intracellular calcium concentration ([Ca2+]i). We hypothesized that, in human pulmonary microvascular endothelial cells, a thrombin-induced increase in permeability to albumin would be dependent on Ca2+i and subsequent actin cytoskeleton rearrangements. METHODS: Human lung microvascular endothelial cells, grown on 0.4 micromol/L pore membranes, were activated with 10 nmol/L human thrombin in Hank's balanced salt solution/0.5% fetal bovine serum. Select cultures were pretreated (45 minutes) with 4 micromol Fura-2/AM to chelate Ca2+i. Permeability was assessed as diffusion of bovine serum albumin/biotin across the monolayer. Similarly treated cells were stained with rhodamine-phalloidin to demonstrate actin cytoskeletal morphology. Separately, cells loaded 2 micromol Fura-2/AM were assessed at OD340/380nm after thrombin exposure to detect free Ca2+i. RESULTS: Intracellular Ca2+ levels increased 15-fold (2 seconds) and fell to baseline (10 minutes) after thrombin. Permeability increased 10-fold (30 minutes), and a shift from cortical to actin stress fiber morphology was observed. Chelation of Ca2+i diminished permeability to baseline and reduced the percentage of cells exhibiting stress fiber formation. CONCLUSION: Thrombin stimulates pulmonary capillary leak by affecting the barrier function of activated pulmonary endothelial cells. These data demonstrate a thrombin-stimulated increase in monolayer permeability, and cytoskeletal F-actin stress fibers were, in part, regulated by endothelial Ca2+i. This early, transient rise in Ca2+i likely activates downstream pathways that more directly affect the intracellular endothelial structural changes that control vascular integrity.


Asunto(s)
Calcio/fisiología , Síndrome de Fuga Capilar/fisiopatología , Permeabilidad Capilar/fisiología , Endotelio Vascular/citología , Células Cultivadas , Humanos , Pulmón/citología , Contracción Muscular/fisiología , Cadenas Ligeras de Miosina , Fosforilación
11.
Physiol Genomics ; 5(1): 35-44, 2001 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-11161004

RESUMEN

During skeletal muscle contraction, NO derived from neuronal nitric oxide synthase (nNOS) in skeletal muscle fibers or from endothelial cells (eNOS) may relax vascular smooth muscle contributing to functional hyperemia. To examine the relative importance of these pathways, smooth muscle myosin regulatory light chain (smRLC) phosphorylation was assessed as an index of vascular tone in isolated extensor digitorum longus (EDL) muscles from C57, nNOS(-/-), and eNOS(-/-) mice. The smRLC phosphorylation (in mol phosphate per mol smRLC) in C57 resting muscles (0.12 +/- 0.04) was increased 3.7-fold (0.44 +/- 0.03) by phenylephrine (PE). Reversal of this increase with electrical stimulation (to 0.19 +/- 0.03; P < 0.05) was partially blocked by N(omega)-nitro-l-arginine (NLA). In nNOS(-/-) EDL, the PE-induced increase in smRLC phosphorylation (0.10 +/- 0.02 to 0.49 +/- 0.04) was partially decreased by stimulation (0.25 +/- 0.04). In eNOS(-/-) EDL, the control value for smRLC was increased (0.24 +/- 0.04), and PE-induced smRLC phosphorylation (0.36 +/- 0.06) was decreased by stimulation even in the presence of NLA (to 0.20 +/- 0.02; P < 0.05). These results suggest that in addition to NO-independent mechanisms, NO derived from both nNOS and eNOS plays a role in the integrative vascular response of contracting skeletal muscle.


Asunto(s)
Fibras Musculares de Contracción Rápida/fisiología , Músculo Liso Vascular/fisiología , Óxido Nítrico/metabolismo , Vasodilatación/fisiología , Animales , Western Blotting , Genotipo , Técnicas In Vitro , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fibras Musculares de Contracción Rápida/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Cadenas Ligeras de Miosina/efectos de los fármacos , Cadenas Ligeras de Miosina/metabolismo , Óxido Nítrico Sintasa/genética , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico Sintasa de Tipo I , Óxido Nítrico Sintasa de Tipo II , Óxido Nítrico Sintasa de Tipo III , Fenilefrina/farmacología , Fosforilación , Vasoconstrictores/farmacología , Vasodilatación/efectos de los fármacos
13.
Physiol Genomics ; 2(1): 21-7, 2000 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-11015578

RESUMEN

Nitric oxide (NO) from Ca(2+)-dependent neuronal nitric oxide synthase (nNOS) in skeletal muscle fibers may modulate vascular tone by a cGMP-dependent pathway similar to NO derived from NOS in endothelial cells (eNOS). In isolated fast-twitch extensor digitorum longus (EDL) muscles from control mice, cGMP formation increased approximately 166% with electrical stimulation (30 Hz, 15 s). cGMP levels were not altered in slow-twitch soleus muscles. The NOS inhibitor N(omega)-nitro-l-arginine abolished the contraction-induced increase in cGMP content in EDL muscles, and the NO donor sodium nitroprusside (SNP) increased cGMP content approximately 167% in noncontracting EDL muscles. SNP treatment but not electrical stimulation increased cGMP formation in muscles from nNOS(-/-) mice. cGMP formation in control and stimulated EDL muscles from eNOS(-/-) mice was less than that obtained with similarly treated muscles from control mice. Arteriolar relaxation in contracting fast-twitch mouse cremaster muscle was attenuated in muscles from mice lacking either nNOS or eNOS. These findings suggest that increases in cGMP and NO-dependent vascular relaxation in contracting fast-twitch skeletal muscle may require both nNOS and eNOS.


Asunto(s)
GMP Cíclico/biosíntesis , Contracción Muscular/fisiología , Músculo Esquelético/irrigación sanguínea , Óxido Nítrico Sintasa/metabolismo , Animales , Vasos Sanguíneos/fisiología , Western Blotting , Estimulación Eléctrica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fibras Musculares de Contracción Rápida/fisiología , Fibras Musculares de Contracción Lenta/fisiología , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiología , Óxido Nítrico Sintasa/genética , Óxido Nítrico Sintasa de Tipo I , Óxido Nítrico Sintasa de Tipo II , Óxido Nítrico Sintasa de Tipo III
14.
J Soc Gynecol Investig ; 7(5): 284-90, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11035280

RESUMEN

OBJECTIVES: To characterize changes in myometrial contractile proteins and myosin heavy chain (MHC) isoforms during ovine fetal and neonatal development and after pregnancy. We hypothesized that ovine myometrium demonstrates progressive cellular differentiation and maturation which begins in utero and extends into the postnatal period, and that pregnancy causes further cellular alterations. METHODS: Myometrium was obtained from female fetal (72- to 140-days of gestation, n = 19; term = approximately 145 days), postnatal (1 day to 3 months, n = 25), and parous noncycling nonpregnant (n = 9) sheep to measure total and soluble proteins, actin, MHC, and MHC isoforms. Contractile proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and expression of 200-kD MHC isoforms were determined with Western immunoblots. RESULTS: The contents of total and soluble proteins and actin and total myosin gradually increase (P <.003) during ovine development. Although the contribution of smooth-muscle 204-kD MHC increased (P <.001) from 23 +/- 8% of total MHC at <100 days of gestation to 75 +/- 2% 3 to 4 months postnatally, the 200-kD species fell proportionately. Before birth, MHC-B, a fetal isoform, is the predominant 200-kD protein; postnatally, it is replaced by SM2, demonstrating a switch from a synthetic to a mature contractile smooth-muscle phenotype. Pregnancy is associated with further increases in actin contents and redistribution of the contents of the 204-kD and SM2 MHC isoforms. CONCLUSIONS: Although the fetal and postnatal uterus has no known functional demand, ovine myometrial differentiation and maturation begin in the midtrimester and continue throughout the postnatal period. Thus, changes in smooth-muscle phenotype occur prenatally, as evidenced by a switch from MHC-B to SM2, which may signal completion of organ development and preparation for adult function. Pregnancy results in further modifications in myometrial proteins.


Asunto(s)
Desarrollo de Músculos , Músculo Liso/crecimiento & desarrollo , Paridad , Útero/crecimiento & desarrollo , Actinas/análisis , Animales , Western Blotting , Electroforesis en Gel de Poliacrilamida , Femenino , Proteínas Musculares/análisis , Músculo Liso/química , Músculo Liso/embriología , Cadenas Pesadas de Miosina/análisis , Miosinas/análisis , Fenotipo , Embarazo , Ovinos , Útero/química , Útero/embriología
15.
Am J Physiol Regul Integr Comp Physiol ; 278(5): R1305-13, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10801301

RESUMEN

Maturation rates of vascular and visceral smooth muscle (SM) during ovine development were compared by quantifying contractile protein, myosin heavy chain (MHC) isoform contents, and contractile properties of aortas and bladders from female fetal (n = 19) and postnatal (n = 21) sheep. Actin, myosin, and protein contents rose progressively throughout development in both tissues (P

Asunto(s)
Desarrollo de Músculos , Músculo Liso Vascular/crecimiento & desarrollo , Músculo Liso/crecimiento & desarrollo , Vejiga Urinaria/crecimiento & desarrollo , Actinas/análisis , Animales , Aorta/química , Aorta/crecimiento & desarrollo , Proteínas Contráctiles/análisis , Femenino , Contracción Isométrica , Proteínas Musculares/análisis , Músculo Liso/química , Músculo Liso/embriología , Músculo Liso Vascular/química , Músculo Liso Vascular/embriología , Cadenas Pesadas de Miosina/análisis , Cadenas Ligeras de Miosina/metabolismo , Quinasa de Cadena Ligera de Miosina/metabolismo , Miosinas/análisis , Fosforilación , Ovinos , Vejiga Urinaria/química , Vejiga Urinaria/embriología
16.
Aktuelle Radiol ; 8(4): 191-5, 1998 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-9759466

RESUMEN

PURPOSE: The relations between image quality in last image hold images and dose in grid controlled fluoroscopy in comparison to the continuous mode need to be characterised and recommendations for the clinical application of this technique should be given. MATERIAL AND METHODS: Spatial resolution, signal-noise ratio and, contrast-detail visibility were evaluated by phantom measurements in grid controlled pulsed and continuous fluoroscopy. Dose was measured at the image intensifier entrance. Image quality of last image hold (LIH) images of clinical examinations was graded in relation to single shot exposures. RESULTS: Signal-noise ratio and contrast-detail visibility depend on the dose per puls. Spatial resolution and contrast-detail visibility in grid controlled fluoroscopy are superior than to in the continuous mode. Image quality of the LIH images from the grid controlled fluoroscopy was improved. Radiation exposure could be reduced to 10-46%. CONCLUSIONS: Combinations of puls-dose and -frequency are recommended for achieving extensive dose reduction and improved image quality of LIH images.


Asunto(s)
Diagnóstico por Imagen/normas , Radiometría , Cintigrafía/normas , Fluorometría , Fluoroscopía , Imagen de Acumulación Sanguínea de Compuerta , Humanos , Garantía de la Calidad de Atención de Salud , Efectos de la Radiación , Intensificación de Imagen Radiográfica
17.
J Cataract Refract Surg ; 24(9): 1195-207, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9768392

RESUMEN

PURPOSE: To investigate suitable application parameters for efficient hyperopic correction by laser thermokeratoplasty (LTK) using mid-infrared laser diodes. SETTING: Medical Laser Center Lübeck, Lübeck, Germany. METHOD: A tunable continuous-wave laser diode in the spectral range between 1.845 and 1.871 microns was used. Transmitted by waveguides, the laser energy was used to induce coagulations on freshly enucleated porcine eyes to increase corneal curvature. The coagulations were equidistantly applied by a fiber-cornea contact and a noncontact focusing device that were adjusted on a ring concentric to the corneal apex. Different laser parameters and application geometries were evaluated. Refractive changes were measured by computer-assisted corneal topography before and after treatment. Polarization light microscopy and temperature calculations were used to analyze the coagulations. RESULTS: Because of the tunability of the laser diode, the influence of the corneal absorption coefficient (between 0.9 and 1.6 mm-1) on the refractive change could be measured. A laser power between 125 and 200 mW was adequate to achieve refractive changes up to 10.0 diopters. In the preferable focusing device, the refractive change increased almost logarithmically with the irradiation time up to 15 seconds. The number of coagulations on a fixed application ring showed no significant influence on refractive change; however, it showed an almost linear decrease with increasing ring diameter from 5.0 to 10.0 mm. Histological analysis revealed 3 stages of thermal damage. CONCLUSION: Diode LTK provided defined and uniform coagulations when using a well-adapted focusing device, resulting in sufficient refractive change. The results indicate that diode LTK is superior to pulsed holmium LTK.


Asunto(s)
Córnea/cirugía , Hiperopía/cirugía , Coagulación con Láser/métodos , Absorción , Animales , Córnea/patología , Córnea/fisiopatología , Hiperopía/patología , Hiperopía/fisiopatología , Microscopía de Polarización , Refracción Ocular , Porcinos
18.
Rofo ; 169(1): 33-7, 1998 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-9711280

RESUMEN

PURPOSE: Is there a loss of information when using selenium radiographic images displayed with reduced image format compared to full format? METHOD: Digital selenium radiographic chest images in two planes were obtained in 35 patients for medical reasons. The digital data sets of each patient were separately displayed in full format on two different films and were printed in reduced format on one film. The format was reduced to 61% of the full format using an acquisition matrix of 2166 x 2488 pixels, an image display matrix of 4000 x 5000 pixels and a film format of 43 x 49 cm. All images were anonymously evaluated by four independent readers using a questionnaire concerning anatomic structures. RESULTS: Format reduction did not result in a loss of information in diagnostically relevant anatomic details. CONCLUSIONS: Displaying digital selenium radiographic data sets of thoracic view in two planes on one film presumably does not lead to a loss of diagnostic information. This procedure may help to reduce film costs.


Asunto(s)
Intensificación de Imagen Radiográfica/métodos , Radiografía Torácica/métodos , Selenio , Película para Rayos X , Adulto , Anciano , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Intensificación de Imagen Radiográfica/instrumentación , Radiografía Torácica/instrumentación , Radiografía Torácica/estadística & datos numéricos , Tórax/anatomía & histología , Película para Rayos X/estadística & datos numéricos
19.
FEBS Lett ; 431(1): 71-4, 1998 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-9684868

RESUMEN

Nitric oxide generated by neuronal nitric oxide synthase in contracting skeletal muscle fibers may regulate vascular relaxation via a cGMP-mediated pathway. Neuronal nitric oxide synthase content is greatly reduced in skeletal muscles from mdx mice. cGMP formation increased in contracting extensor digitorum longus muscles in vitro from C57 control, but not mdx mice. The increase in cGMP content was abolished with NG-nitro-L-arginine. Sodium nitroprusside treatment increased cGMP levels in muscles from both C57 and mdx mice. Skeletal muscle contractions also inhibited phenylephrine-induced phosphorylation of smooth muscle myosin regulatory light chain. Arteriolar dilation was attenuated in contracting muscles from mdx but not C57 mice. NO generated in contracting skeletal muscle may contribute to vasodilation in response to exercise.


Asunto(s)
GMP Cíclico/metabolismo , Músculo Esquelético/fisiología , Músculo Liso Vascular/metabolismo , Miosinas/metabolismo , Óxido Nítrico/metabolismo , Animales , Humanos , Técnicas In Vitro , Masculino , Ratones , Ratones Endogámicos C57BL , Contracción Muscular , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/metabolismo , Distrofias Musculares/metabolismo , Cadenas Ligeras de Miosina/metabolismo , Fosforilación , Esfuerzo Físico , Vasodilatación
20.
Am J Physiol ; 274(6): R1815-23, 1998 06.
Artículo en Inglés | MEDLINE | ID: mdl-9841554

RESUMEN

In fetal sheep, umbilical responsiveness to ANG II exceeds systemic vascular responsiveness. Fetal systemic vascular smooth muscle (VSM) exhibits an immature phenotype with decreased contractile protein contents, low 200-kDa myosin heavy chain (MHC) SM2, and significant nonmuscle MHC-B expression, whereas umbilical VSM phenotype is incompletely described. We tested the hypothesis that differences in vascular responsiveness could reflect dissimilarities in VSM phenotype. Actin, MHC, MHC isoforms, and active stresses were compared in strips of femoral arteries and aorta from near-term fetal (n = 12) and adult (n = 12) sheep to those in external and intra-abdominal umbilical arteries. Actin contents in fetal femoral artery and aorta were less (P

Asunto(s)
Arterias/metabolismo , Proteínas Musculares/metabolismo , Músculo Liso Vascular/metabolismo , Actinas/metabolismo , Animales , Aorta/embriología , Aorta/metabolismo , Arterias/embriología , Arteria Femoral/embriología , Arteria Femoral/metabolismo , Contracción Muscular , Músculo Liso Vascular/embriología , Cadenas Pesadas de Miosina/metabolismo , Cadenas Ligeras de Miosina/metabolismo , Fenotipo , Fosforilación , Ovinos , Arterias Umbilicales/embriología , Arterias Umbilicales/metabolismo
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