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1.
J Thromb Thrombolysis ; 50(1): 217-220, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31707622

RESUMEN

Patients who require urgent warfarin reversal often receive four-factor prothrombin complex concentrate (4F-PCC), which is traditionally dosed according to weight and initial INR. Our institution implemented a fixed-dose 4F-PCC strategy, using an initial dose of 1500 units. We evaluated the frequency with which the initial fixed dose 4F-PCC was inadequate, as defined by need for supplemental dosing. As part of the protocol, if the initial fixed-dose 4F-PCC is administered and does not achieve INR goal, then the remainder of the standard weight- and INR-based dosing can be given. During the study period, 63 patients on warfarin received 4F-PCC using the fixed-dose protocol. Based on the INR following 4F-PCC administration, 11 patients (17%) were eligible to receive a supplemental dose based on failure to achieve their specified INR goal. Two of the 11 patients eligible for supplemental 4F-PCC dosing received the second dose, both with initial supratherapeutic INRs > 3.5. We found that most patients given an initial fixed-dose 4F-PCC achieved their INR goals, and of those who did not, most did not receive supplemental dosing, suggesting that clinical providers felt that adequate hemostasis had been achieved. In addition, fixed-dose 4F-PCC was able to be given rapidly, with few dosing errors, suggesting that this is a reasonable option for 4F-PCC delivery.


Asunto(s)
Factores de Coagulación Sanguínea/administración & dosificación , Cálculo de Dosificación de Drogas , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Warfarina/efectos adversos , Anciano de 80 o más Años , Peso Corporal , Protocolos Clínicos , Relación Dosis-Respuesta a Droga , Monitoreo de Drogas/métodos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/etiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/terapia , Femenino , Humanos , Relación Normalizada Internacional , Masculino , Evaluación de Procesos y Resultados en Atención de Salud , Estudios Retrospectivos
2.
Brain Imaging Behav ; 13(2): 472-481, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29667043

RESUMEN

The "cognitive dysmetria" hypothesis suggests that impairments in cognition and behavior in patients with schizophrenia can be explained by disruptions in the cortico-cerebellar-thalamic-cortical circuit. In this study we examine thalamo-cortical connections in patients with first-episode schizophrenia (FESZ). White matter pathways are investigated that connect the thalamus with three frontal cortex regions including the anterior cingulate cortex (ACC), ventrolateral prefrontal cortex (VLPFC), and lateral oribitofrontal cortex (LOFC). We use a novel method of two-tensor tractography in 26 patients with FESZ compared to 31 healthy controls (HC), who did not differ on age, sex, or education. Dependent measures were fractional anisotropy (FA), Axial Diffusivity (AD), and Radial Diffusivity (RD). Subjects were also assessed using clinical functioning measures including the Global Assessment of Functioning (GAF) Scale, the Global Social Functioning Scale (GF: Social), and the Global Role Functioning Scale (GF: Role). FESZ patients showed decreased FA in the right thalamus-right ACC and right-thalamus-right LOFC pathways compared to healthy controls (HCs). In the right thalamus-right VLPFC tract, we found decreased FA and increased RD in the FESZ group compared to HCs. After correcting for multiple comparisons, reductions in FA in the right thalamus- right ACC and the right thalamus- right VLPC tracts remained significant. Moreover, reductions in FA were significantly associated with lower global functioning scores as well as lower social and role functioning scores. We report the first diffusion tensor imaging study of white matter pathways connecting the thalamus to three frontal regions. Findings of white matter alterations and clinical associations in the thalamic-cortical component of the cortico-cerebellar-thalamic-cortical circuit in patients with FESZ support the cognitive dysmetria hypothesis and further suggest the possible involvement of myelin sheath pathology and axonal membrane disruption in the pathogenesis of the disorder.


Asunto(s)
Imagen de Difusión Tensora/métodos , Procesamiento de Imagen Asistido por Computador , Esquizofrenia/patología , Tálamo/patología , Sustancia Blanca/patología , Adulto , Anisotropía , Encéfalo/patología , Estudios Transversales , Femenino , Giro del Cíngulo/patología , Humanos , Masculino , Corteza Prefrontal/patología , Adulto Joven
3.
J Affect Disord ; 222: 88-97, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28688266

RESUMEN

BACKGROUND: Maladaptive responses to negative affective stimuli are pervasive, including clinically ill and healthy people, and men and women respond differently at neural and hormonal levels. Inspired by the Research Domain Criteria initiative, we used a transdiagnostic approach to investigate the impact of sex and dysphoric mood on neural-hormonal responses to negative affective stimuli. METHODS: Participants included 99 individuals with major depressive disorder, psychosis and healthy controls. Functional magnetic resonance imaging (fMRI) was complemented with real-time acquisition of hypothalamo-pituitary-adrenal (HPA) and -gonadal (HPG) hormones. fMRI data were analyzed in SPM8 and task-related connectivity was assessed using generalized psychophysiological interaction. RESULTS: Across all participants, elevated cortisol response predicted lower brain activity in orbitofrontal cortex and hypothalamus-amygdala connectivity. In those with worse dysphoric mood, elevated cortisol response predicted lower activity in hypothalamus and hippocampus. In women, elevated cortisol response was associated with lower activity in medial prefrontal cortex and low hypothalamo-hippocampal connectivity. In women with high dysphoric mood, elevated cortisol response was associated with low hypothalamo-hippocampal connectivity. There were no interactions with diagnosis or medication. LIMITATIONS: There was limited power to correct for multiple comparisons across total number of ROIs and connectivity targets; cortisol responses were relatively low. CONCLUSIONS: We conclude that the pathophysiology in neural-hormonal responses to negative affective stimuli is shared across healthy and clinical populations and varies as a function of sex and dysphoric mood. Our findings may contribute to the development of hormonal adjunctive therapeutics that are sex-dependent, underscoring the importance of one's sex to precision medicine.


Asunto(s)
Afecto/fisiología , Trastorno Depresivo Mayor/fisiopatología , Trastornos Psicóticos/fisiopatología , Factores Sexuales , Adulto , Amígdala del Cerebelo/fisiopatología , Trastorno Depresivo Mayor/diagnóstico por imagen , Trastorno Depresivo Mayor/psicología , Femenino , Hipocampo/fisiopatología , Humanos , Hidrocortisona/fisiología , Sistema Hipotálamo-Hipofisario/fisiología , Hipotálamo/fisiopatología , Imagen por Resonancia Magnética , Masculino , Sistema Hipófiso-Suprarrenal/fisiología , Corteza Prefrontal/fisiopatología , Trastornos Psicóticos/diagnóstico por imagen , Trastornos Psicóticos/psicología , Adulto Joven
4.
Scand J Gastroenterol ; 39(6): 557-66, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15223681

RESUMEN

BACKGROUND: Abnormal crypt proliferation and development in the colon has been associated with premalignant stages of colon cancer. Conventionally, molecular markers are used to detect abnormal crypt proliferation. METHODS: In the present work, feasibility studies of FTIR-MSP to distinguish between normal and abnormal crypts from colon biopsies that show normal histopathological features have been undertaken. RESULTS: The results indicate that abnormal crypts show deviations in the pattern of absorbance in the Mid IR region along the crypt height when compared with the normal crypts. The crypts could be empirically classified into three groups such as crypts having a normal absorbance pattern for all biochemical components, crypts with abnormal absorbance pattern for some biochemical components and crypts with completely abnormal absorbance pattern along the height for all or most biochemical components studied by FTIR. The utilization of FTIR-MSP is proposed for diagnosis of abnormal metabolism at the molecular level of histologically completely normal-looking crypts, especially from those biopsies that are taken from sites far away from cancer. CONCLUSIONS: This method could give rise to a reduction in false-negative results during examination of biopsies using the conventional histopathological methods. The present method may be complementary to existing methods for precise demarcation of the zone of colostomy prior to colon cancer surgery.


Asunto(s)
Colon/metabolismo , Colon/patología , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Espectroscopía Infrarroja por Transformada de Fourier , División Celular , Movimiento Celular , Colon/ultraestructura , Neoplasias del Colon/ultraestructura , ADN/metabolismo , Estudios de Factibilidad , Humanos , ARN/metabolismo , Tirosina/metabolismo
5.
Am J Epidemiol ; 154(5): 434-41, 2001 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-11532785

RESUMEN

Research on the relation between phytoestrogens and breast cancer risk has been limited in scope. Most epidemiologic studies have involved Asian women and have examined the effects of traditional soy foods (e.g., tofu), soy protein, or urinary excretion of phytoestrogens. The present study extends this research by examining the effects of a spectrum of phytoestrogenic compounds on breast cancer risk in non-Asian US women. African-American, Latina, and White women aged 35-79 years, who were diagnosed with breast cancer between 1995 and 1998, were compared with women selected from the general population via random digit dialing. Interviews were conducted with 1,326 cases and 1,657 controls. Usual intake of specific phytoestrogenic compounds was assessed via a food frequency questionnaire and a newly developed nutrient database. Phytoestrogen intake was not associated with breast cancer risk (odds ratio = 1.0, 95% confidence interval: 0.80, 1.3 for the highest vs. lowest quartile). Results were similar for pre- and postmenopausal women, for women in each ethnic group, and for all seven phytoestrogenic compounds studied. Phytoestrogens appear to have little effect on breast cancer risk at the levels commonly consumed by non-Asian US women: an average intake equivalent to less than one serving of tofu per week.


Asunto(s)
Neoplasias de la Mama/epidemiología , Estrógenos no Esteroides/administración & dosificación , Isoflavonas , Plantas , Adulto , Negro o Afroamericano/estadística & datos numéricos , Anciano , Neoplasias de la Mama/etnología , Estudios de Casos y Controles , Conducta Alimentaria , Femenino , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Modelos Logísticos , Persona de Mediana Edad , Fitoestrógenos , Preparaciones de Plantas , Factores de Riesgo , San Francisco/epidemiología , Población Blanca/estadística & datos numéricos
6.
Physician Exec ; 26(3): 20-5, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10947459

RESUMEN

Complexity theory offers a powerful model for effective mergers of health care organizations that differs substantially from customary approaches. Exploring how Deaconess Billings Clinic in Montana evolved from two separate and very different cultures provides insight into how organizations can apply a complex adaptive system (CAS) model of mergers to create more truly integrated health care systems. DBC's merger illustrates the phenomenon of emergence in complex systems, whereby structures arise that are not a synthesis of the pre-existing cultures or the result of a new culture being imposed. Instead, the merger is understood as an ongoing, self-organizing process appropriately characterized by fits and starts, feelings of uncertainty, and other natural challenges of change and growth. By squarely surfacing the distinct cultures of the organizations through abundant interaction, relationship building, and information flow, differences can be creatively transformed, resulting in deep-seated change and the emergence of a genuine, shared health care system culture.


Asunto(s)
Instituciones de Atención Ambulatoria/organización & administración , Instituciones Asociadas de Salud/organización & administración , Hospitales Filantrópicos/organización & administración , Innovación Organizacional , Conflicto Psicológico , Eficiencia Organizacional , Montana , Cultura Organizacional
7.
8.
Biol Psychiatry ; 46(7): 941-54, 1999 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-10509177

RESUMEN

BACKGROUND: Schizophrenia is characterized by subcortical and cortical brain abnormalities. Evidence indicates that some nonpsychotic relatives of schizophrenic patients manifest biobehavioral abnormalities, including brain abnormalities. The goal of this study was to determine whether amygdala-hippocampal and thalamic abnormalities are present in relatives of schizophrenic patients. METHODS: Subjects were 28 nonpsychotic, and nonschizotypal, first-degree adult relatives of schizophrenics and 26 normal control subjects. Sixty contiguous 3 mm coronal, T1-weighted 3D magnetic resonance images of the brain were acquired on a 1.5 Tesla magnet. Cortical and subcortical gray and white matter and cerebrospinal fluid (CSF) were segmented using a semi-automated intensity contour mapping algorithm. Analyses of covariance of the volumes of brain regions, controlling for expected intellectual (i.e., reading) ability and diagnosis, were used to compare groups. RESULTS: The main findings were that relatives had significant volume reductions bilaterally in the amygdala-hippocampal region and thalamus compared to control subjects. Marginal differences were noted in the pallidum, putamen, cerebellum, and third and fourth ventricles. CONCLUSIONS: Results support the hypothesis that core components of the vulnerability to schizophrenia include structural abnormalities in the thalamus and amygdala-hippocampus. These findings require further work to determine if the abnormalities are an expression of the genetic liability to schizophrenia.


Asunto(s)
Amígdala del Cerebelo/anomalías , Predisposición Genética a la Enfermedad/genética , Hipocampo/anomalías , Imagen por Resonancia Magnética , Esquizofrenia/genética , Trastorno de la Personalidad Esquizotípica/genética , Tálamo/anomalías , Adulto , Algoritmos , Amígdala del Cerebelo/patología , Mapeo Encefálico , Dominancia Cerebral/fisiología , Femenino , Hipocampo/patología , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Valores de Referencia , Esquizofrenia/diagnóstico , Trastorno de la Personalidad Esquizotípica/diagnóstico , Tálamo/patología
9.
AJNR Am J Neuroradiol ; 19(7): 1349-52, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9726481

RESUMEN

We report a case of increased signal in the left hemicord at the C4 level on T2-weighted MR images after chiropractic manipulation, consistent with contusion. The patient displayed clinical features of Brown-Séquard syndrome, which stabilized with immobilization and steroids. Follow-up imaging showed decreased cord swelling with persistent increased signal. After physical therapy, the patient regained strength on the left side, with residual decreased sensation to pain involving the right arm.


Asunto(s)
Síndrome de Brown-Séquard/etiología , Manipulación Espinal/efectos adversos , Tirantes , Síndrome de Brown-Séquard/diagnóstico , Síndrome de Brown-Séquard/terapia , Contusiones/diagnóstico , Contusiones/etiología , Contusiones/terapia , Femenino , Glucocorticoides/uso terapéutico , Humanos , Hipoestesia/fisiopatología , Inmovilización , Imagen por Resonancia Magnética , Metilprednisolona/uso terapéutico , Persona de Mediana Edad , Contracción Muscular/fisiología , Fármacos Neuroprotectores/uso terapéutico , Modalidades de Fisioterapia , Traumatismos de la Médula Espinal/diagnóstico , Traumatismos de la Médula Espinal/etiología , Traumatismos de la Médula Espinal/terapia
10.
Biol Psychiatry ; 43(9): 649-59, 1998 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-9582998

RESUMEN

BACKGROUND: The thalamus, an important subcortical brain region connecting limbic and prefrontal cortices, has a significant role in sensory and cortical processing. Although inconsistently, previous studies have demonstrated neuroanatomical abnormalities in the thalamus of schizophrenic patients. METHODS: This structural magnetic resonance imaging study, based on segmentation of contiguous coronal 1.5-mm images, compared thalamic brain volumes of 15 chronic, male schizophrenic patients with 15 normal controls matched on age, sex, handedness, and parental socioeconomic status. RESULTS: There were no significant differences between patients and controls in thalamic volumes, right or left, adjusted for total brain volume; however, there were significantly different correlations of thalamic volumes with prefrontal white matter and lateral ventricles among patients, but not among controls. Thalamic volumes among patients were also significantly correlated with bizarre behavior, hallucinations, and thought disorder. CONCLUSIONS: Findings suggest that connectivity between thalamic nuclei and prefrontal cortical areas are abnormal in chronic male schizophrenic patients. In addition, ventricular enlargement may be, in part, due to subtle reduction in thalamic volume and/or in volume of thalamocortical and corticothalamic fibers secondary to thalamic abnormalities. Finally, correlations with positive symptomatology underscore the role of the thalamus in gating or filtering of sensory information and coordination of cortical processing.


Asunto(s)
Esquizofrenia/patología , Tálamo/patología , Adulto , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Psicología del Esquizofrénico
11.
Physician Exec ; 24(1): 6-20, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-10180491

RESUMEN

The authors explore complexity science, a relatively new field of inquiry, which holds for both clinicians and health care leaders the real possibility of stimulating fresh insights and approaches to health and medical care-both its provision and its organization. Two case studies are presented to illustrate how complexity theory can provide health care leaders with a new perspective on how to address the myriad challenges they confront daily: (1) a patient with dissociative identity disorder; and (2) a physician task group charged to advise on hospital medical staff reorganization and governance. These case studies help clinicians and leaders of health care organizations understand how complexity: (1) may be relevant, even helpful, as they consider difficult challenges in both patient and organizational management; and (2) might emerge as a synthesizing force as they face the extraordinarily complicated task of jointly creating integrated health care systems. A resource section is provided for those who may wish to further pursue the topic.


Asunto(s)
Atención a la Salud/organización & administración , Dinámicas no Lineales , Innovación Organizacional , Adulto , Trastorno Disociativo de Identidad/terapia , Femenino , Humanos , Equipos de Administración Institucional , Liderazgo , Cuerpo Médico de Hospitales/organización & administración , Estudios de Casos Organizacionales , Objetivos Organizacionales , Ejecutivos Médicos , Técnicas de Planificación , Estados Unidos
12.
Plast Reconstr Surg ; 100(3): 643-52, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9283562

RESUMEN

Human adjuvant disease is the label given to a syndrome that resembles a connective tissue disease such as scleroderma and that has been hypothesized to follow augmentation mammoplasty with silicone gel implants or silicone with adulerants. To date, there is no proof that pure silicone is the cause of these symptoms. The cases presented in the literature suggest a comparison to the events seen in the rat adjuvant arthritis model. Male Lew/SsN rats (n = 65) were used. To evaluate both the adjuvant and antigenic properties of the gel implant, variations of the standard Freund's complete adjuvant inoculum were prepared. Tested were the abilities of low molecular weight silicone to act as an adjuvant and for fumed silica to act as an antigen by modifying a rat adjuvant arthritis model to include silicone and fumed silica. On day 0, 0.25 ml of each inoculum was injected intradermally into the plantar aspect of the hindfoot of each rat. The foot diameter was recorded at each time period, compared with the contralateral hindfoot, and normalized to controls at regular time periods over the course of 120 days. Silicone oil did not act as an adjuvant. Furthermore, fumed silica alone did not act as an antigen; however, it is capable of eliciting a reaction that is both delayed and uncharacteristic of the rat adjuvant arthritis model. These results indicate that "human adjuvant disease" may be inappropriate and misleading.


Asunto(s)
Adyuvantes Inmunológicos , Artritis Experimental/etiología , Dióxido de Silicio/efectos adversos , Aceites de Silicona/efectos adversos , Animales , Antígenos , Artritis Experimental/patología , Enfermedades Autoinmunes/etiología , Implantes de Mama , Enfermedades del Tejido Conjuntivo/etiología , Enfermedades del Tejido Conjuntivo/inmunología , Pie , Adyuvante de Freund/inmunología , Masculino , Mycobacterium/inmunología , Ratas , Ratas Endogámicas Lew , Dióxido de Silicio/inmunología , Aceites de Silicona/inmunología
13.
Mol Cell ; 1(1): 47-57, 1997 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9659902

RESUMEN

We report the cloning of a gene, S2P, that encodes a putative metalloprotease required for intramembrane proteolysis of sterol-regulatory element-binding proteins (SREBPs) at Site-2. SREBPs are membrane-bound transcription factors that activate genes regulating cholesterol metabolism. The active NH2-terminal domains of SREBPs are released from membranes by sequential cleavage at two sites: Site-1, within the lumen of the endoplasmic reticulum; and Site-2, within a transmembrane segment. The human S2P gene was cloned by complementation of mutant CHO cells that cannot cleave SREBPs at Site-2 and are cholesterol auxotrophs. S2P defines a new family of polytopic membrane proteins that contain an HEXXH sequence characteristic of zinc metalloproteases. Mutation of the putative zinc-binding residues abolishes S2P activity. S2P encodes an unusual metalloprotease that cleaves proteins within transmembrane segments.


Asunto(s)
Proteínas Potenciadoras de Unión a CCAAT , Proteínas de Unión al ADN/metabolismo , Endopeptidasas/genética , Endopeptidasas/metabolismo , Proteínas Nucleares/metabolismo , Factores de Transcripción , Animales , Células CHO/enzimología , Clonación Molecular , Cricetinae , Análisis Mutacional de ADN , ADN Complementario , Regulación Enzimológica de la Expresión Génica , Genes Reporteros , Prueba de Complementación Genética , Humanos , Luciferasas , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Metaloendopeptidasas/genética , Metaloendopeptidasas/metabolismo , Datos de Secuencia Molecular , Mutación/fisiología , Homología de Secuencia de Aminoácido , Proteína 1 de Unión a los Elementos Reguladores de Esteroles , Transfección
14.
Headache ; 36(8): 514-5, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8824009

RESUMEN

Valproic acid has been shown to be effective in migraine prophylaxis. Its method of action is believed to be the inhibition of gamma-aminobutyric acid transaminase. The therapeutic dose needed to prevent migraine headaches has been examined in several studies, yet the optimum dose has not been found. In this case report, valproic acid was given to a 24-year-old woman with chronic headaches at 1000 mg per day. Her headaches resolved for 2 months. She tapered herself off of the medication, and her headaches returned. She was restarted at 500 mg per day of valproic acid and again, her headaches resolved. She preferred being on the lower dose which she found as effective as the higher dose. Her case makes two interesting points. The first is that lower dosages of valproic acid may be as effective as higher ones in headache prophylaxis. The second is that more studies looking at dose ranges are needed to correlate effectiveness with daily requirements.


Asunto(s)
GABAérgicos/administración & dosificación , Trastornos Migrañosos/prevención & control , Ácido Valproico/administración & dosificación , Adulto , Enfermedad Crónica , Ensayos Clínicos como Asunto , Relación Dosis-Respuesta a Droga , Femenino , Humanos
15.
Proc Natl Acad Sci U S A ; 93(11): 5437-42, 1996 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-8643593

RESUMEN

We have purified from hamster liver a second cysteine protease that cleaves and activates sterol regulatory element binding proteins (SREBPs). cDNA cloning revealed that this enzyme is the hamster equivalent of Mch3, a human enzyme that is related to the interleukin 1beta converting enzyme. We call this enzyme Mch3/SCA-2. It is 54% identical to hamster CPP32/SCA-1, a cysteine protease that was earlier shown to cleave SREBPs at a conserved Asp between the basic helix-loop-helix leucine zipper domain and the membrane attachment domain. This cleavage liberates an NH2-terminal fragment of approximately 460 amino acids that activates transcription of genes encoding the low density lipoprotein receptor and enzymes of cholesterol synthesis. Mch3/SCA-2 and CPP32/SCA-I are synthesized as inactive 30-35 kDa precursors that are thought to be cleaved during apoptosis to generate active fragments of approximately 20 and approximately 10 kDa. The current data lend further support to the notion that SREBPs are cleaved and activated as part of the program in programmed cell death.


Asunto(s)
Apoptosis , Proteínas Potenciadoras de Unión a CCAAT , Caspasas , Cisteína Endopeptidasas/metabolismo , Proteínas de Unión al ADN/metabolismo , Hígado/enzimología , Proteínas Nucleares/metabolismo , Factores de Transcripción , Secuencia de Aminoácidos , Animales , Ácido Aspártico , Secuencia de Bases , Caspasa 3 , Cromatografía , Cromatografía en Gel , Cromatografía por Intercambio Iónico , Clonación Molecular , Secuencia Conservada , Cricetinae , Cisteína Endopeptidasas/biosíntesis , Cisteína Endopeptidasas/aislamiento & purificación , Cartilla de ADN , ADN Complementario , Secuencias Hélice-Asa-Hélice , Humanos , Leucina Zippers , Masculino , Mesocricetus , Datos de Secuencia Molecular , Poli(ADP-Ribosa) Polimerasas/metabolismo , Reacción en Cadena de la Polimerasa , Biosíntesis de Proteínas , Homología de Secuencia de Aminoácido , Proteína 1 de Unión a los Elementos Reguladores de Esteroles , Especificidad por Sustrato
16.
Arch Biochem Biophys ; 327(2): 324-9, 1996 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-8619622

RESUMEN

Alpha-Galactosidase (alpha-GAL) purified from green coffee bean cleaves the terminal galactose residues from the surface of group B erythrocytes, thereby converting these cells serologically to group O cells. Such enzymatically converted red cells have been transfused into group A and O recipients as part of the first phase of FDA-approved clinical trials. Recently we expressed the recombinant alpha-GAL (r)alpha-GAL) in large quantities in a methylotrophic yeast strain Pichia pastoris and purified the protein to apparent homogeneity by chromatography on a macro prep S50 column. Purified (r)alpha-GAL, migrating as a single band of 41 kDa on a SDS-PAGE, appears to be identical to its native counterpart in specific activity (32 U/mg) and kinetic parameters (K(m) =0.363 mM and V(max) = 46.9 U/mg). Both enzymes demonstrate the same pH profile in the pH range from 2 to 9, with an optimal pH at 6.4 when tested with the substrate p-nitrophenol-alpha-D-galactopyranoside. Furthermore, as with its native counterpart, (r)alpha-GAL specifically cleaves alpha-linked terminal galactose residues from group B red cells without affecting other major antigens on the red cell surface. In addition, we developed a method for using RT-PCR to detect possible DNA contamination in the purified protein preparation, which is one of the concerns for in vivo studies. Thus, with a simple procedure for over-expression and purification of (r)alpha-GAL from P. pastoris culture, one can readily obtain the enzyme needed for large-scale sero-conversion of red cells.


Asunto(s)
Sistema del Grupo Sanguíneo ABO , Café/enzimología , Eritrocitos/metabolismo , Proteínas Recombinantes/metabolismo , alfa-Galactosidasa/metabolismo , Sistema del Grupo Sanguíneo ABO/metabolismo , Cromatografía en Gel , Electroforesis en Gel de Poliacrilamida , Estabilidad de Enzimas , Eritrocitos/inmunología , Glicosilación , Humanos , Concentración de Iones de Hidrógeno , Cinética , Peso Molecular , Pichia/enzimología , Reacción en Cadena de la Polimerasa , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/aislamiento & purificación , Especificidad por Sustrato , Factores de Tiempo , alfa-Galactosidasa/biosíntesis , alfa-Galactosidasa/aislamiento & purificación
17.
Arch Biochem Biophys ; 324(1): 65-70, 1995 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-7503561

RESUMEN

alpha-Galactosidase isolated from coffee beans cleaves the terminal alpha-galactose residues from oligosaccharide chains on blood group B red cells, thus generating group O cells. Such enzymatically converted red cells not only maintain full erythrocyte integrity and viability in vitro, but also demonstrate immune tolerance and a normal life span in vivo. In order to produce large quantities of recombinant alpha-galactosidase for use in the study of blood-type conversion, we subcloned the cDNA coding for coffee bean alpha-galactosidase into the EcoRI site of the vector pPIC9 in order to express the enzyme in Pichia pastoris, a methylotrophic yeast strain. After P. pastoris transformation, colonies were screened for high-level expression of alpha-galactosidase, based on enzyme activity. In order to increase enzyme production, the growth conditions in the shake flask culture and fermentor culture were optimized. Under the conditions applied, biologically active alpha-galactosidase was produced and secreted into the culture medium at a level of approximately 0.4 g per liter of the fermentor culture. The protein was purified to apparent homogeneity by a simple chromatography procedure, as suggested by a single band of 41 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its homogeneity was further confirmed by chromatofocusing and N-terminal sequencing. P. pastoris appears to be the choice as host for the large-scale production of recombinant alpha-galactosidase used for blood type conversion.


Asunto(s)
Café/enzimología , Semillas/enzimología , alfa-Galactosidasa/biosíntesis , Secuencia de Aminoácidos , Secuencia de Bases , Café/genética , Datos de Secuencia Molecular , Pichia/genética , Pichia/crecimiento & desarrollo , Proteínas Recombinantes/biosíntesis , Semillas/genética , Selección Genética , Transformación Genética , alfa-Galactosidasa/genética , alfa-Galactosidasa/aislamiento & purificación
18.
Hear Res ; 89(1-2): 52-68, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8600132

RESUMEN

Recent observations of combination tones and low-frequency suppression in the mechanical response of the basilar membrane have eliminated uncertainty of the existence of these non-linear phenomena at this stage of the cochlea (Robles et al., 1991; Ruggero et al., 1992b; Rhode and Cooper, 1993), and provide the first opportunity to test and extend theoretical understanding of these non-linear responses. This paper reports a systematic study of the new data for the chinchilla with the MBPNL (multiple band-pass non-linearity) non-linear model for rapid compression in cochlear filtering (Goldstein, 1990). The two key findings are that: (1) the large differences in suppression growth rates for low- and high-frequency suppressors are closely predicted by the model, although a statistically significant small bias in the prediction was found; and (2) combination tones of frequency 2f2-f1 were well predicted by the model, while reported levels of 2f1-f2 were underestimated by the model. The most likely explanation of the result for 2f1-f2 is that the model correctly predicts the distributed generation of combination tones, but does not include a propagating medium that allows combination tones to accumulate at their tuned site. Alternative explanations requiring experimental clarification are suggested. The general finding of this study is that the complex level-dependent properties of suppression and combination tones are closely related to the three regions characterizing the tuned response of the basilar membrane, in which linear-like responses at low and high sound levels are joined by a compressive range. The MBPNL model describes this general relationship quantitatively and is a reliable basis for further modeling research.


Asunto(s)
Membrana Basilar/fisiología , Modelos Biológicos , Estimulación Acústica , Interpretación Estadística de Datos , Humanos , Dinámicas no Lineales , Psicoacústica
19.
RN ; 58(8): 10, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7638539
20.
Lupus ; 4(3): 172-5, 1995 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7655485

RESUMEN

Hyperbaric oxygen has been used in patients with rheumatic disease for many years without reports of untoward or unusual complications for a variety of non-rheumatic indications. Recent evidence that hyperbaric oxygen inhibits the actions of certain cytokines, acts as an immune modulator and may help cognitive dysfunction has resulted in a re-examination of its potential role in rheumatic diseases. A case report of a lupus/scleroderma crossover patient is presented whose cognitive dysfunction improved after hyperbaric oxygen therapy. The history of hyperbaric oxygen and its physiology are related, along with a focused review of its effects on the immune and central nervous systems. Areas which might warrant further consideration by rheumatologists are outlined, as well as areas of concern.


Asunto(s)
Oxigenoterapia Hiperbárica , Enfermedades Reumáticas/terapia , Trastornos del Conocimiento/terapia , Femenino , Humanos , Oxigenoterapia Hiperbárica/efectos adversos , Persona de Mediana Edad , Esclerodermia Sistémica/terapia
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