RESUMEN
Pseudotropheus livingstonii and P. elegans are two sand-dwelling cichlid species that belong to the so-called mbuna, a group of predominantly rock-dwelling haplochromines of Lake Malawi. The identity of these two species has confused taxonomists for almost a century until a recent rediscovery of representatives of P. elegans close to its type locality. New diagnoses for both species are provided.
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Cíclidos/anomalías , Cíclidos/clasificación , África , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Cíclidos/anatomía & histología , Cíclidos/crecimiento & desarrollo , Ecosistema , Femenino , Lagos/análisis , Malaui , Masculino , Tamaño de los ÓrganosRESUMEN
The breadth of literature regarding barbed suture applications in plastic surgical procedures and of importance to this article, barbed suture applications in breast surgery, is growing dramatically as surgical practitioners are becoming more familiar with the advantages of this new suture technology. Barbed suture devices were first implemented by plastic surgeons for the use in various minimally invasive techniques for facial rejuvenation, but have now surpassed these applications and are now much more commonly used in Breast and Body closures.
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Mama/cirugía , Mastectomía/métodos , Suturas , Femenino , Humanos , ReoperaciónAsunto(s)
Bloqueo Nervioso/estadística & datos numéricos , Dosis de Radiación , Protección Radiológica/estadística & datos numéricos , Radiografía Intervencional/estadística & datos numéricos , Esteroides/administración & dosificación , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Femenino , Humanos , MasculinoRESUMEN
The purpose of this study is to determine the lowest concentration of subcutaneous phenylephrine (neosynephrine) required for effective vasoconstriction in skin graft donor sites. Surgery for burn injury is associated with blood loss. Tourniquet use and tumescence with epinephrine have decreased blood loss. However, absorption of epinephrine has been reported with systemic effects. Phenylephrine, an α1-adrenergic receptor agonist, has vasoconstrictive properties similar to epinephrine's without other α-adrenergic or ß-adrenergic activity. The aim of this study is to determine the lowest effective concentration of phenylephrine that will provide vasoconstriction in split-thickness graft donor sites. By using intensive care unit equivalency tables, the authors estimated a concentration of phenylephrine on the basis of current epinephrine tumescence. This concentration was titrated up or down according to an algorithm established a priori, determining the minimum concentration that achieved vasoconstriction in three consecutive patients. The primary outcome was local vasoconstriction. Secondary outcomes measured were pre-, intra-, and postoperative mean arterial pressure, systolic pressure and heart rate, graft take, and donor site healing. The subjects were six otherwise healthy adult patients (five men and one woman) with a mean age of 36 years. The average TBSA was 737.5 cm². Vasoconstriction was achieved at 5 µg/ml. No significant alterations in hemodynamic measures were observed. The optimal concentration of phenylephrine for prevention of bleeding in donor sites appears to be 5 µg/ml. Participants will be able to identify the effects of phenylephrine and epinephrine tumescence. They will also identify the concentration at which phenylephrine will be effective in donor sites.
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Agonistas de Receptores Adrenérgicos alfa 1/administración & dosificación , Quemaduras/cirugía , Fenilefrina/administración & dosificación , Trasplante de Piel , Agonistas de Receptores Adrenérgicos alfa 1/farmacología , Adulto , Femenino , Humanos , Masculino , Fenilefrina/farmacología , Estadísticas no Paramétricas , Donantes de Tejidos , Vasoconstricción/efectos de los fármacosRESUMEN
Franz Sikora found the first specimen and type of the recently extinct Hadropithecus stenognathus in Madagascar in 1899 and sent it to Ludwig Lorenz von Liburnau of the Austrian Imperial Academy of Sciences. Later, he sent several more specimens including a subadult skull that was described by Lorenz von Liburnau in 1902. In 2003, some of us excavated at the locality and found more specimens belonging to this species, including much of a subadult skeleton. Two frontal fragments were found, and these, together with most of the postcranial bones, belong to the skull. CT scans of the skull and other jaw fragments were made in Vienna and those of the frontal fragments at Penn State University. The two fragments have been reunited with the skull in silico, and broken parts from one side of the skull have been replaced virtually by mirror-imaged complete parts from the other side. The parts of the jaw of another individual of a slightly younger dental age have also been reconstructed virtually from CT scans with mirror imaging and by using the maxillary teeth and temporomandibular joints as a guide to finish the reconstruction. Apart from forming a virtual skull for biomechanical and systematic analysis, we were also able to make a virtual endocast. Missing anterior pieces were reconstructed by using part of an endocast of the related Archaeolemur majori. The volume is 115 ml. Hadropithecus and Archaeolemur seem to have had relatively large brains compared with the other large-bodied subfossil lemurs.
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Fósiles , Modelos Anatómicos , Cráneo/anatomía & histología , Strepsirhini/anatomía & histología , Animales , MadagascarRESUMEN
The medical records and magnetic resonance images of 33 dogs with surgically confirmed Hansen type I cervical intervertebral disc disease were reviewed. Fourteen of the dogs were chondrodystrophic and 19 were not chondrodystrophic. The most common clinical sign was neck pain, which affected 28 of the dogs, and 23 of the dogs were able to walk. Fifteen of the dogs had developed clinical signs acutely, within the previous 24 hours. On cross-sectional images the median area of spinal cord compression was 26 per cent (range 11 to 71 per cent) of the normal spinal cord area. The degree of spinal cord compression was significantly associated with the dogs' presurgical neurological status but not with their postsurgical neurological status. The dogs with an acute onset of clinical signs had more severe neurological dysfunction before surgery, but their condition improved more as a result of surgery.
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Vértebras Cervicales/patología , Enfermedades de los Perros/diagnóstico , Desplazamiento del Disco Intervertebral/veterinaria , Imagen por Resonancia Magnética/veterinaria , Compresión de la Médula Espinal/veterinaria , Animales , Perros , Femenino , Desplazamiento del Disco Intervertebral/diagnóstico , Masculino , Pronóstico , Estudios Retrospectivos , Compresión de la Médula Espinal/diagnósticoRESUMEN
A number of methods for measuring anisotropy in trabecular bone using high-resolution X-ray computed tomography exist, which give different answers but have not been compared in detail. In this study, we examine the mean-intercept length (MIL), star volume distribution (SVD) and star length distribution (SLD) methods, their algorithmic implementation for three-dimensional (3D) data, and how their results relate to each other. A uniform ordered sampling scheme for determining which orientations to sample during analysis enhances the reproducibility of anisotropy and principal component direction determinations, with no evident introduction of biasing. This scheme also facilitates the creation of a 3D rose diagram that can be used to gain additional insights from the data. The directed secant algorithm that is frequently used for traversing pixel and voxel grids for these calculations is prone to bias unless a previously unreported normalization is used. This normalization ameliorates the bias present when using cubic voxels, and also permits calculations on data sets in which the slice spacing is not equal to the pixel spacing. Overall, the three methods for quantification of anisotropy give broadly similar results, but there are systematic divergences that can be traced to their differences in data and processing, and which may impact on their relative utility in estimating mechanical properties. Although discussed in the context of computed tomography of trabecular bone, the methods described here may be applied to any 3D data set from which fabric information is desired.
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Huesos/anatomía & histología , Huesos/diagnóstico por imagen , Cabeza Femoral/anatomía & histología , Cabeza Femoral/diagnóstico por imagen , Algoritmos , Animales , Anisotropía , Densidad Ósea , Procesamiento de Imagen Asistido por Computador , Primates/anatomía & histología , Tomografía Computarizada por Rayos XRESUMEN
Different lines of evidence suggest that trabecular bone architecture contains a functional signal related to an organism's locomotor behavior. An understanding of the interspecific and intraspecific variation in extant nonhuman primate trabecular structure is needed to evaluate its usefulness as a tool to reconstruct the locomotor habits of extinct primates. High-resolution X-ray computed tomography (HRXCT) is a new imaging approach with a resolution in the tens of microns that allows nondestructive access to the internal structure of bony elements. Previous studies indicate that such resolution is necessary to accurately quantify structural parameters of trabecular bone. The primary goal of this study was to test the accuracy of HRXCT by comparing stereological measurements from HRXCT images and histological thin sections of cancellous bone taken from the proximal femur and humerus of baboons. To this end, 11 bone samples were scanned on an HRXCT scanner and then thin-sectioned to reveal the scanned plane. HRXCT images were thresholded using a modified half-maximum height protocol. The stereological measurements included bone volume fraction (BV/TV), trabecular number (Tb.N), bone surface to volume ratio (BS/BV), trabecular thickness (Tb.Th), and trabecular spacing (Tb.Sp). The measurement errors on the HRXCT images were 10.90% for BV/TV, 6.06% for Tb.N, 14.19% for BS/BV, 14.33% for Tb.Th, and 7.09% for Tb.Sp, but none of these measurements were significantly different from the histological standards (alpha = 0.05). A second goal of this study was to examine the influence of thresholding, a necessary step in any morphometric study using computed tomography, on the accuracy of the quantitative morphometry. Threshold values derived from a modified half-maximum height protocol showed that parameters derived from the region of interest (area in which stereological measurements were later taken) produced better reconstructions of the actual bone structure than threshold values derived from more inclusive areas of bone. We conclude that HRXCT can accurately reconstruct the complex architecture of trabecular bone, and that thresholding is a nontrivial step in trabecular bone studies, with even slight changes in the protocol greatly affecting the morphometric data. HRXCT represents a valuable analytical tool that should be of interest to a great many researchers in physical anthropology because it allows nondestructive access to internal morphology, thereby preserving valuable and limited skeletal collections.
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Antropología Física/métodos , Fémur/ultraestructura , Húmero/ultraestructura , Locomoción , Papio/anatomía & histología , Tomografía Computarizada por Rayos X , Animales , Fenómenos Biomecánicos , Fémur/anatomía & histología , Húmero/anatomía & histología , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Plasma xanthine oxidase (XO) activity was defined as a source of enhanced vascular superoxide (O(2)( *-)) and hydrogen peroxide (H(2)O(2)) production in both sickle cell disease (SCD) patients and knockout-transgenic SCD mice. There was a significant increase in the plasma XO activity of SCD patients that was similarly reflected in the SCD mouse model. Western blot and enzymatic analysis of liver tissue from SCD mice revealed decreased XO content. Hematoxylin and eosin staining of liver tissue of knockout-transgenic SCD mice indicated extensive hepatocellular injury that was accompanied by increased plasma content of the liver enzyme alanine aminotransferase. Immunocytochemical and enzymatic analysis of XO in thoracic aorta and liver tissue of SCD mice showed increased vessel wall and decreased liver XO, with XO concentrated on and in vascular luminal cells. Steady-state rates of vascular O(2)( *-) production, as indicated by coelenterazine chemiluminescence, were significantly increased, and nitric oxide (( *)NO)-dependent vasorelaxation of aortic ring segments was severely impaired in SCD mice, implying oxidative inactivation of ( *)NO. Pretreatment of aortic vessels with the superoxide dismutase mimetic manganese 5,10,15,20-tetrakis(N-ethylpyridinium-2-yl)porphyrin markedly decreased O(2)( small middle dot-) levels and significantly restored acetylcholine-dependent relaxation, whereas catalase had no effect. These data reveal that episodes of intrahepatic hypoxia-reoxygenation associated with SCD can induce the release of XO into the circulation from the liver. This circulating XO can then bind avidly to vessel luminal cells and impair vascular function by creating an oxidative milieu and catalytically consuming (*)NO via O(2)( small middle dot-)-dependent mechanisms.
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Anemia de Células Falciformes/fisiopatología , Endotelio Vascular/fisiopatología , Relajación Muscular/fisiología , Óxido Nítrico/fisiología , Superóxidos/metabolismo , Alanina Transaminasa/sangre , Animales , Endotelio Vascular/metabolismo , Eritrocitos/metabolismo , Humanos , Técnicas In Vitro , Ratones , Ratones Noqueados , Xantina Oxidasa/sangreRESUMEN
Mutations causing truncations of the cytoplasmic domain of the human erythropoietin receptor (EPOR) result in a dominantly inherited disorder-primary familial congenital polycythemia. This disorder is characterized by increased numbers of erythrocytes (polycythemia) and by in vitro hypersensitivity of erythroid precursors to erythropoietin. The consequences of EPOR truncation in nonerythroid tissues are unknown. We replaced the murine EPOR gene with a wild-type human EPOR gene and a mutant human EPOR gene that we initially identified in a patient with polycythemia. This mutation leads to an EPOR truncated after the first tyrosine residue of the intracellular domain. Mice heterozygous for this mutant allele and a wild-type human EPOR allele mimicked the human disorder. Interestingly, mice that were homozygous for the mutant human allele were severely polycythemic but viable. Our results provide a model for functional studies of EPOR-triggered signaling pathways in erythropoiesis. These animals can now be used to investigate the molecular pathophysiology of this gain-of-function EPOR mutation in erythroid tissue and in those nonerythroid tissues that express EPOR.
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Policitemia/genética , Receptores de Eritropoyetina/genética , Eliminación de Secuencia , Animales , Modelos Animales de Enfermedad , Células Precursoras Eritroides/efectos de los fármacos , Células Precursoras Eritroides/fisiología , Eritropoyetina/farmacología , Heterocigoto , Ratones , Ratones Transgénicos , Policitemia/congénito , Receptores de Eritropoyetina/fisiología , Recombinación Genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Madre/fisiología , Transcripción GenéticaRESUMEN
The persistence of fetal hemoglobin in many patients with deletion type beta thalassemias and the expression patterns of human globin genes in transgenic mice suggest that gamma- to beta-globin gene switching results primarily from competition of gamma- and beta-globin genes for interaction with the beta-globin locus control region (LCR). To define regulatory sequences that are essential for the competitive advantage of the gamma gene at early developmental stages, stable transgenic mouse lines were produced with LCR gamma-beta constructs containing deletions of gamma 5'-flanking DNA. All constructs contained the full 22 kb LCR, a 4.1 kb beta-globin gene and a gamma-globin gene with 1348, 383, 202, 130, 72 or 52 bp of 5'-flanking sequence. Primer extension analysis of yolk sac, fetal liver and blood RNA from these lines demonstrated that a region between -202 and -130 of the human gamma-globin gene promoter was required to suppress beta-globin gene expression at early developmental stages. Four transcription factor binding sites within this region [GATA(p), Oct1, GATA(d) and CACCC] were mutated independently in LCR gamma-beta constructs and transgenic mouse lines were produced. Only the gamma CACCC box mutation resulted in high levels of beta-globin gene expression in early embryos. These results demonstrate that the CACCC box of the human gamma-globin gene plays a critical role in human beta-globin gene developmental specificity. The data also suggest that gamma CACCC box binding factors mediate LCR-gamma interactions which normally enhance gamma-globin and suppress beta-globin gene expression in fetal erythroid cells.
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Globinas/genética , Regiones Promotoras Genéticas/genética , Factores de Transcripción/metabolismo , Animales , Secuencia de Bases , Sitios de Unión/genética , ADN/genética , ADN/metabolismo , Proteínas de Unión al ADN/metabolismo , Regulación del Desarrollo de la Expresión Génica , Factor C1 de la Célula Huésped , Humanos , Hígado/embriología , Hígado/metabolismo , Región de Control de Posición/genética , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular , Mutación , Factor 1 de Transcripción de Unión a Octámeros , Unión Proteica , ARN Mensajero/genética , ARN Mensajero/metabolismo , Eliminación de Secuencia , Transgenes/genética , Saco Vitelino/metabolismoRESUMEN
Resistance exercise training was well tolerated in patients with stable, chronic heart failure, resulting in increased strength and endurance, and lower oxygen consumption at submaximum workloads but no improvement in VO2peak. There was also a significant increase in basal forearm blood flow following this form of exercise training.
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Terapia por Ejercicio , Insuficiencia Cardíaca/terapia , Músculo Esquelético/fisiopatología , Resistencia Física , Fenómenos Biomecánicos , Enfermedad Crónica , Femenino , Antebrazo/irrigación sanguínea , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno , Estudios Prospectivos , Ventilación Pulmonar , Flujo Sanguíneo RegionalRESUMEN
The random insertion of transgenes into the genomic DNA of mice usually leads to widely variable levels of expression in individual founder lines. To study the mechanisms that cause variegation, we designed a transgene that we expected to variegate, which consisted of a beta-globin locus control region 5' HS-2 linked in tandem to a tagged human beta-globin gene (into which a Lac-Z cassette had been inserted). All tested founder lines exhibited red blood cell-specific expression, but levels of expression varied >1000-fold from the lowest to the highest expressing line. Most of the variation in levels of expression appeared to reflect differences in the percentage of cells in the peripheral blood that expressed the transgene, which ranged from 0.3% in the lowest expressing line to 88% in the highest; the level of transgene expression per cell varied no more than 10-fold from the lowest to the highest expressing line. These differences in expression levels could not be explained by the location of transgene integration, by an effect of beta-galactosidase on red blood cell survival, by the half life of the beta-galactosidase enzyme or by the age of the animals. The progeny of all early erythroid progenitors (BFU-E colony-forming cells) exhibited the same propensity to variegate in methylcellulose-based cultures, suggesting that the decision to variegate occurs after the BFU-E stage of erythroid differentiation. Collectively, these data suggest that variegation in levels of transgene expression are due to local, integration site-dependent phenomena that alter the probability that a transgene will be expressed in an appropriate cell; however, these local effects have a minimal impact on the transgene's activity in the cells that initiate transcription.
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Regulación del Desarrollo de la Expresión Génica/fisiología , Globinas/genética , Región de Control de Posición/genética , Transgenes/genética , Factores de Edad , Animales , Supervivencia Celular , Células Cultivadas , Células Precursoras Eritroides , Variación Genética , Humanos , Ratones , Ratones Transgénicos , Reticulocitos/citología , Procesos Estocásticos , beta-Galactosidasa/sangre , beta-Galactosidasa/genéticaRESUMEN
OBJECTIVE: To investigate the frequency and longitudinal course of symptoms of depression, agitation, and psychosis in a longitudinally studied sample of patients with Alzheimer's disease (AD). DESIGN: Longitudinal study of AD patients with follow-up assessments at 6-month intervals for an average of more than 3 years. SETTING: Alzheimer's Disease Research Center of the Mount Sinai Medical Center and the Bronx VA Medical Center, New York. PARTICIPANTS: A total of 153 AD patients. MEASUREMENTS: Blessed Test of Information, Memory and Concentration (BIMC) and the Alzheimer's Disease Assessment Scale cognitive (ADAS-Cog) and noncognitive (ADAS-NC) subscales. RESULTS: At entry into the study, more than 90% of patients had a behavioral disturbance that was rated as mild or worse on one of the 10 ADAS noncognitive items; and 40% had at least one rating that was moderate or severe. Correlational analyses indicated that, with the exception of the two mood-related items, noncognitive symptoms on the ADAS were not highly correlated with one another. Only one of the noncognitive items, concentration, was strongly correlated with the severity of cognitive impairment. On average, patients showed progressively worse cognitive functioning over time as measured both by the ADAS-Cog and the BIMC. The mean severity of noncognitive symptoms did not change during the course of a 5-year follow up. The severity of behavioral disturbance at any one evaluation was negatively correlated with change in behavior during the next 6 months and was not correlated with cognitive decline. CONCLUSION: Mild behavioral disturbances are common, whereas moderate to severe behavioral symptoms are less frequent in this population of AD patients. Disturbances in mood and manifestations of agitation and psychotic symptoms are not closely related to one another and show little progressive worsening over time. Rather, they tend to be episodic such that increasing severity at one time is usually followed by improvement later. Concentration problems are a manifestation of cognitive dysfunction rather than behavioral disturbance in AD. Implications of these results for treatment of noncognitive disturbances in AD are discussed.
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Enfermedad de Alzheimer/complicaciones , Trastornos del Conocimiento/complicaciones , Depresión/epidemiología , Trastornos Mentales/epidemiología , Trastornos Psicóticos/epidemiología , Actividades Cotidianas , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/fisiopatología , Trastornos del Conocimiento/fisiopatología , Estudios Transversales , Depresión/etiología , Análisis Factorial , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Masculino , Trastornos Mentales/clasificación , Trastornos Mentales/etiología , New York/epidemiología , Trastornos Psicóticos/etiologíaRESUMEN
When transgenic mice that expressed human sickle hemoglobin were mated with mice having knockout mutations of the mouse alpha- and beta-globin genes, animals were produced that synthesized only human hemoglobin in adult red blood cells. Similar to many human patients with sickle cell disease, the mice developed a severe hemolytic anemia and extensive organ pathology. Numerous sickled erythrocytes were observed in peripheral blood. Although chronically anemic, most animals survived for 2 to 9 months and were fertile. Drug and genetic therapies can now be tested in this mouse model of sickle cell disease.
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Anemia de Células Falciformes , Modelos Animales de Enfermedad , Anemia de Células Falciformes/sangre , Anemia de Células Falciformes/genética , Anemia de Células Falciformes/patología , Animales , Cromatografía Líquida de Alta Presión , Cruzamientos Genéticos , Eritrocitos/patología , Globinas/genética , Hemoglobina Falciforme/genética , Hemoglobinas/genética , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones TransgénicosAsunto(s)
Fuerza Laboral en Salud/tendencias , Educación Médica/tendencias , Fuerza Laboral en Salud/economía , Humanos , Personal de Laboratorio Clínico/provisión & distribución , Enfermeras y Enfermeros/provisión & distribución , Médicos/provisión & distribución , Práctica Privada , Población Rural , Federación de Rusia , Salarios y Beneficios , Población UrbanaRESUMEN
The present study evaluated the safety of and obtained preliminary data on the cognitive effects of L-deprenyl and physostigmine in patients with Alzheimer's Disease. Seventeen outpatients with Alzheimer's Disease participated in a double-blind crossover study in which they received 4 weeks of L-deprenyl at a dose of 10 mg p.o., q.d., and 4 weeks of placebo in random order. During both the L-deprenyl and placebo periods, patients received cognitive assessments during physostigmine (0.5 mg) and placebo infusions separated by 2 days. The cognitive effects of these agents alone and in combination were measured with digit span, verbal fluency, list learning, praxis, delayed recall, and delayed recognition tasks. Fifteen patients completed the study. The two drugs, used alone or in combination, were safe and well tolerated. Analyses of variance demonstrated that neither physostigmine nor L-deprenyl, whether given alone or in combination, significantly improved cognition, when compared with the double placebo condition.
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Enfermedad de Alzheimer/tratamiento farmacológico , Inhibidores de la Colinesterasa/uso terapéutico , Inhibidores de la Monoaminooxidasa/uso terapéutico , Fisostigmina/uso terapéutico , Selegilina/uso terapéutico , Administración Oral , Anciano , Enfermedad de Alzheimer/psicología , Inhibidores de la Colinesterasa/efectos adversos , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Esquema de Medicación , Quimioterapia Combinada , Femenino , Humanos , Infusiones Intravenosas , Masculino , Recuerdo Mental/efectos de los fármacos , Persona de Mediana Edad , Inhibidores de la Monoaminooxidasa/efectos adversos , Pruebas Neuropsicológicas , Fisostigmina/efectos adversos , Retención en Psicología/efectos de los fármacos , Selegilina/efectos adversos , Resultado del Tratamiento , Aprendizaje Verbal/efectos de los fármacosRESUMEN
beta zero-Thalassemia is an inherited disorder characterized by the absence of beta-globin polypeptides derived from the affected allele. The molecular basis for this deficiency is a mutation of the adult beta-globin structural gene or cis regulatory elements that control beta-globin gene expression. A mouse model of this disease would enable the testing of therapeutic regimens designed to correct the defect. Here we report a 16-kb deletion that includes both adult beta-like globin genes, beta maj and beta min, in mouse embryonic stem cells. Heterozygous animals derived from the targeted cells are severely anemic with dramatically reduced hemoglobin levels, abnormal red cell morphology, splenomegaly, and markedly increased reticulocyte counts. Homozygous animals die in utero; however, heterozygous mice are fertile and transmit the deleted allele to progeny. The anemic phenotype is completely rescued in progeny derived from mating beta zero-thalassemic animals with transgenic mice expressing high levels of human hemoglobin A. The beta zero-thalassemic mice can be used to test genetic therapies for beta zero-thalassemia and can be bred with transgenic mice expressing high levels of human hemoglobin HbS to produce an improved mouse model of sickle cell disease.
Asunto(s)
Eliminación de Gen , Globinas/genética , Talasemia beta/genética , Animales , Southern Blotting , Quimera , Cruzamientos Genéticos , Modelos Animales de Enfermedad , Embrión de Mamíferos , Eritrocitos/citología , Eritrocitos/patología , Femenino , Fertilidad , Hemoglobinas/biosíntesis , Heterocigoto , Homocigoto , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Fenotipo , Recombinación Genética , Células Madre/fisiologíaRESUMEN
Postmortem findings point to significant abnormalities in central noradrenergic function in Alzheimer's disease (AD) which may be associated with changes in peripheral markers. In this study, the relationship between the peripheral noradrenergic marker, plasma 3-methoxy-4-hydroxyphenylglycol (MHPG), and clinical symptoms was examined in 23 patients with probable AD. Basal MHPG levels correlated significantly with increased cognitive impairment (r = .58, p = .005), controlling for age, age at onset, gender, and time interval between plasma MHPG determination and cognitive testing. These results suggest that plasma MHPG increases as cognitive function in AD deteriorates, further supporting preliminary evidence for increases in noradrenergic indices in association with disease severity in AD.