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1.
Artículo en Inglés | MEDLINE | ID: mdl-29203485

RESUMEN

Therapies for human African trypanosomiasis and Chagas disease, caused by Trypanosoma brucei and Trypanosoma cruzi, respectively, are limited, providing minimal therapeutic options for the millions of individuals living in very poor communities. Here the effects of 10 novel quinolines are evaluated in silico and by phenotypic studies using in vitro and in vivo models. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties revealed that most molecules did not infringe on Lipinski's rules, which is a prediction of good oral absorption. These quinolines showed high probabilities of Caco2 permeability and human intestinal absorption and low probabilities of mutagenicity and of hERG1 inhibition. In vitro screens against bloodstream forms of T. cruzi demonstrated that all quinolines were more active than the reference drug (benznidazole [Bz]), except for DB2171 and DB2192, with five (DB2187, DB2131, DB2186, DB2191, and DB2217) displaying 50% effective concentrations (EC50s) of <3 µM (4-fold lower than that of Bz). Nine quinolines were more effective than Bz (2.7 µM) against amastigotes, showing EC50s ranging from 0.6 to 0.1 µM. All quinolines were also highly active in vitro against African trypanosomes, showing EC50s of ≤0.25 µM. The most potent and highly selective candidates for each parasite species were tested in in vivo models. Results for DB2186 were promising in mice with T. cruzi and T. brucei infections, reaching a 70% reduction of the parasitemia load for T. cruzi, and it cured 2 out of 4 mice infected with T. brucei DB2217 was also active in vivo and cured all 4 mice (100% cure rate) with T. brucei infection.


Asunto(s)
Enfermedad de Chagas/tratamiento farmacológico , Quinolinas/farmacología , Tripanocidas/farmacología , Trypanosoma brucei brucei/efectos de los fármacos , Trypanosoma cruzi/efectos de los fármacos , Animales , Células CACO-2 , Línea Celular , Línea Celular Tumoral , Femenino , Humanos , Masculino , Mamíferos , Ratones , Parasitemia/tratamiento farmacológico , Ratas
2.
Epidemiol Infect ; 143(5): 960-5, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25420688

RESUMEN

SUMMARY Fluoroquinolone use before tuberculosis (TB) diagnosis delays the time to diagnosis and treatment, and increases the risk of fluoroquinolone-resistant TB and death. Ascertainment of fluoroquinolone exposure could identify such high-risk patients. We compared four methods of ascertaining fluoroquinolone exposure in the 6 months prior to TB diagnosis in culture-confirmed TB patients in Tennessee from January 2007 to December 2009. The four methods included a simple questionnaire administered to all TB suspects by health department personnel (FQ-Form), an in-home interview conducted by research staff, outpatient and inpatient medical record review, and TennCare pharmacy database review. Of 177 TB patients included, 72 (41%) received fluoroquinolones during the 6 months before TB diagnosis. Fluoroquinolone exposure determined by review of inpatient and outpatient medical records was considered the gold standard for comparison. The FQ-Form had 61% [95% confidence interval (CI) 48-73] sensitivity and 93% (95% CI 85-98) specificity (agreement 79%, kappa = 0.56) while the in-home interview had 28% (95% CI 18-40) sensitivity and 99% (94-100%) specificity (agreement 68%, kappa = 0.29). A simple questionnaire administered by health department personnel identified fluoroquinolone exposure before TB diagnosis with moderate reliability.


Asunto(s)
Antibacterianos/uso terapéutico , Fluoroquinolonas/administración & dosificación , Entrevistas como Asunto/métodos , Anamnesis/métodos , Tuberculosis Pulmonar/diagnóstico , Adulto , Bases de Datos Factuales , Diagnóstico Tardío , Farmacorresistencia Bacteriana , Femenino , Humanos , Masculino , Registros Médicos , Persona de Mediana Edad , Farmacias , Encuestas y Cuestionarios , Tennessee , Tuberculosis/diagnóstico
3.
J Radiol Prot ; 34(1): 15-29, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24270156

RESUMEN

The ICRP has recently recommended that the occupational exposure limit for the lens of the eye be reduced to 20 mSv in a year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv. There has been concern amongst some groups of individuals, particularly interventional cardiologists and radiologists as well as relevant professional bodies, that implementation of these recommendations into UK law will adversely affect working patterns. However, despite a number of informative European studies, there is currently little UK dosimetry data available upon which judgements can effectively be based. In order to address this knowledge gap, Public Health England has carried out a small, targeted survey of UK lens doses to medical staff undertaking procedures likely to involve the highest levels of radiation exposure. Two out of a total of 61 individuals surveyed had projected annual doses which could be close to 20 mSv, measured outside lead glasses. Use of protective equipment was generally good; however, lead glasses were only used by 9 participants. The results of this survey suggest that compliance with the ICRP recommendations is likely to be possible for most individuals in the UK medical sector.


Asunto(s)
Personal de Salud , Cristalino/efectos de la radiación , Exposición Profesional/estadística & datos numéricos , Salud Pública , Dosis de Radiación , Salud Radiológica , Humanos , Reino Unido
4.
J Eur Acad Dermatol Venereol ; 26(5): 644-50, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21689167

RESUMEN

BACKGROUND: The association between psoriasis and inflammatory bowel disease (IBD) has been previously reported although a great deal remains unknown about associated comorbidities. OBJECTIVES: The aim of this study was to examine comorbidities in individuals diagnosed with both psoriasis and IBD, and to compare those with individuals diagnosed with psoriasis-only. We also looked at differences within the IBD group by clearly defining that cohort. METHODS: We included 146 patients diagnosed with both psoriasis and IBD and 146 controls diagnosed of psoriasis-only without previous records of IBD, matched by gender, ethnicity and age (±5 years). Patients were obtained from the research patient data repository of Brigham and Women's Hospital (BWH) and Massachusetts General Hospital. Controls were obtained from the psoriatic arthritis and psoriasis follow-up study (PAFS) at BWH. The comparison between the two groups included socio-demographics, comorbidities and laboratory inflammation parameters. RESULTS: Compared to individuals with psoriasis-only, patients with both psoriasis and IBD had significantly higher rates of autoimmune thyroiditis (2.1% vs. 6.8%), hepatitis (0.7 vs. 6.2%) and diabetes (11.0% vs. 26.7%). In addition, of the 146 patients with psoriasis and IBD, 60 (41.1%) were diagnosed with seronegative arthritis. The average C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) of the last visits in our clinics were significantly elevated compared to the individuals with psoriasis-only (ESR, 33.5 vs. 4.0 mm/h; CRP, 9.1 vs. 2.3 mg/L; both P-values <0.0001). CONCLUSIONS: We found that patients with both, psoriasis and IBD have a number of further associated comorbidities, some at significantly higher levels than individuals with psoriasis-only. Common inflammatory pathways and genetic predispositions for specific patterns in the immune response may play an important role in the evolution of associated conditions.


Asunto(s)
Enfermedades Inflamatorias del Intestino/complicaciones , Psoriasis/complicaciones , Anciano , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad
5.
J Exp Med ; 178(6): 2201-6, 1993 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-8245791

RESUMEN

We previously reported that culture of murine fetal liver (FL) cells with interleukin 7 (IL-7) results in expression of high levels of T cell receptor (TCR) gamma transcripts by a population of cells expressing Thy-1 and Pgp-1, suggesting that IL-7 promotes the growth and/or differentiation of pre-T cells. We demonstrate herein that culture of FL cells for 7 d with IL-7 caused the rearrangement and expression of TCR gamma variable (V) region genes V gamma 4 and V gamma 6, but not V gamma 5 or V gamma 7. Since this effect was not blocked by hydroxyurea, it appeared to represent induction of expression of these genes by IL-7 rather than expansion of a preexisting positive population. We also show that IL-7 induced RAG-1 and RAG-2 mRNA expression by FL cells. These data provide evidence that specific TCR gamma/delta V region genes can be rearranged and expressed by T lineage cells before their migration to the thymus, in response to IL-7.


Asunto(s)
Proteínas de Unión al ADN , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T/efectos de los fármacos , Proteínas de Homeodominio , Interleucina-7/farmacología , Hígado/embriología , Receptores de Antígenos de Linfocitos T gamma-delta/genética , Linfocitos T/citología , Animales , Secuencia de Bases , Diferenciación Celular/efectos de los fármacos , Cartilla de ADN/química , Expresión Génica/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Datos de Secuencia Molecular , Proteínas/genética , ARN Mensajero/genética
6.
Anaesthesia ; 70(8): 1008, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26152267
7.
Br J Dermatol ; 161(4): 778-84, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19566664

RESUMEN

BACKGROUND: There is a need to validate psoriasis self-reports in epidemiological studies, where individuals may not be seeing dermatologists or other health care providers. OBJECTIVES: To develop and pilot test the Psoriasis Screening Tool (PST) in an ambulatory setting. PATIENTS AND METHODS: The PST was designed with eight closed-ended questions requiring a 'yes' or 'no' response. Typical images of skin, nail and scalp changes in psoriasis were included with respective questions. We administered the PST to 222 consecutive individuals being seen at a dermatology clinic. All English-speaking subjects completed the PST without assistance. A board-certified dermatologist established the diagnosis of psoriasis or excluded psoriasis in all participants. RESULTS: A total of 222 completed PST questionnaires were included for analysis. There were 111 individuals in the psoriasis group and 111 individuals in the nonpsoriasis group. A combination of three questions resulted in a sensitivity of 96.4% [95% confidence interval (CI) 93.2-98.0] and specificity of 97.3% (95% CI 94.1-98.9) for psoriasis. Adding a pictorial question increased the sensitivity of the screening tool to 98.2% (95% CI 95.0-99.5). Of the 111 individuals with psoriasis, 69% answered yes to having plaque-type psoriasis, 50% answered yes to having nail involvement, 66% answered yes to having scalp involvement, and 59% answered yes to having inverse-type psoriasis. CONCLUSIONS: This pilot study suggests that the PST can distinguish individuals with psoriasis from individuals without psoriasis in an English-speaking population being seen at an outpatient dermatology clinic. Furthermore, the PST may be used to identify psoriasis phenotypes. Although the PST may be limited by spectrum bias in this pilot study, we believe it remains a reliable tool to collect information on psoriasis in remote populations.


Asunto(s)
Psoriasis/diagnóstico , Encuestas y Cuestionarios , Adolescente , Adulto , Edad de Inicio , Algoritmos , Niño , Preescolar , Femenino , Necesidades y Demandas de Servicios de Salud , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Prevalencia , Psoriasis/epidemiología , Psoriasis/genética , Sensibilidad y Especificidad , Adulto Joven
8.
Neurogastroenterol Motil ; 30(9): e13349, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29644797

RESUMEN

BACKGROUND: Multiple sclerosis (MS) is an autoimmune disease of the central nervous system that, in addition to motor, sensory, and cognitive symptoms, also causes constipation, which is poorly understood. Here, we characterize gastrointestinal (GI) dysmotility in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS and evaluate whether autoantibodies target the enteric nervous system (ENS) and cause dysmotility. METHODS: EAE was induced in male SJL and B6 mice. GI motility was assessed in vivo and ex vivo in wild type (WT) and B cell-deficient mice. MS and EAE serum was used to survey potential targets in the ENS and changes in the ENS structure were characterized using immunohistochemistry. KEY RESULTS: EAE mice developed accelerated gastric emptying and delayed whole GI transit with reduced colonic motility. Fecal water content was reduced, and colonic migrating myoelectrical complexes (CMMC) and slow waves were less frequent. Colons from EAE mice exhibited decreased GFAP levels in glia. Sera from MS patients and from EAE mice targeted ENS neurons and glia. B-cell deficiency in EAE protected against colonic dysmotility. CONCLUSIONS & INFERENCES: Consistent with symptoms experienced in MS, we demonstrate that EAE mice widely exhibit features of GI dysmotility that persisted in the absence of extrinsic innervation, suggesting direct involvement of ENS neurocircuitry. The absence of GI dysmotility in B cell-deficient mice with EAE together with EAE and MS serum immunoreactivity against ENS targets suggests that MS could be classified among other diseases known to induce autoimmune GI dysmotility.


Asunto(s)
Autoanticuerpos/inmunología , Estreñimiento/inmunología , Encefalomielitis Autoinmune Experimental/complicaciones , Encefalomielitis Autoinmune Experimental/inmunología , Motilidad Gastrointestinal/inmunología , Animales , Sistema Nervioso Entérico/inmunología , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/inmunología , Neuroglía/inmunología , Neuronas/inmunología
9.
Chem Commun (Camb) ; 53(71): 9934-9937, 2017 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-28829464

RESUMEN

The first example of an in-chain metallo-poly(triazolate) synthesized by CuAAC is reported. Azido-platinum-acetylide (A-M-B) monomers are catalytically polymerized with copper(i) acetate to yield 1,2,3-triazolate linked Pt(ii) units. The metallopolymers are characterized by multinuclear NMR, IR, UV/Vis, GPC, and MS.

10.
Injury ; 47(1): 43-9, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26377772

RESUMEN

BACKGROUND: Whole-body CT (WBCT) has become routine practice in the assessment of major trauma patients. Whilst this may be associated with increased survival, several studies report high rates of negative scans. As no national guideline exists, selection criteria for WBCT vary widely. This study aims to (1) produce a scoring system that improves patient selection for WBCT (2) quantify patient radiation doses and their concomitant risk of malignancy. METHODS: Clinical notes were reviewed for all patients undergoing a WBCT for trauma over a 21-month period at a UK major trauma centre. Clinical and radiological findings were categorised according to body region. Univariate analysis was performed using Chi-squared testing, followed by multivariable logistic regression. Secondary regression analysis of patients with significant injuries that the model did not identify was performed. The model was optimised and used to develop a scoring system. Sensitivity and specificity were calculated using the same dataset as was used to derive the models. Radiation exposure was determined and the excess lifetime risk of malignancy calculated. RESULTS: 255 patients were included, with a mean age of 45 years. 16% of scans were positive for polytrauma, 42% demonstrated some injury and 42% showed no injury. The regression model identified independent predictors of polytrauma to be (1) clinical signs in more than one body region, (2) reduced Glasgow Coma Score, (3) haemodynamic abnormality, (4) respiratory abnormality, (5) mechanism of injury. The final model had a sensitivity of 95% (95% CI 86-99%) and specificity of 59% (95% CI 52-66%) for significant CT findings. Mean radiation exposure was 31.8 mSv, conferring a median excess malignancy risk of 1 in 474. CONCLUSION: After including neurological deficit, our scoring system had a sensitivity of 97% (95% CI 88-99%) and specificity of 56% (95% CI 49-64%) for significant injury. We propose this is used to stratify the use of trauma radiographs, focused CT and WBCT for major trauma patients. Although not intended to replace clinical judgement, our scoring system adds an objective component to decision-making. We believe this will safely reduce the number of unnecessary CT scans performed on a relatively young cohort of patients.


Asunto(s)
Traumatismo Múltiple/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Centros Traumatológicos , Imagen de Cuerpo Entero , Femenino , Humanos , Puntaje de Gravedad del Traumatismo , Modelos Logísticos , Masculino , Traumatismo Múltiple/terapia , Selección de Paciente , Dosis de Radiación , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad , Reino Unido/epidemiología , Procedimientos Innecesarios
11.
Circulation ; 103(12): 1656-61, 2001 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-11273993

RESUMEN

BACKGROUND: -Defibrillator shocks often fail to terminate ventricular fibrillation (VF) in out-of-hospital cardiac arrest (OOHCA), and repeated failed shocks can worsen the subsequent response to therapy. Because the VF waveform changes with increasing duration of VF, it is possible that ECG analyses could estimate the preshock likelihood of defibrillation success. This study examined whether an amplitude-independent measure of preshock VF waveform morphology predicts outcome after defibrillation. Methods and Results-Clinical data and ECG recordings from an automated external defibrillator were obtained for 75 subjects with OOHCA in a suburban community with police first responders and a paramedic-based emergency medical system. An estimate of the fractal self-similarity dimension, the scaling exponent, was calculated off-line for the VF waveform preceding shocks. Success of the first shock was determined from the recordings. Return of pulses and survival were determined by chart review. The first shock resulted in an organized rhythm in 43% of cases, and 17% of cases survived to hospital discharge. A lower mean value of the scaling exponent was observed for cases in which the first defibrillation resulted in an organized rhythm (P:=0.004), for cases with return of pulses (P:=0.049), and for cases surviving to hospital discharge (P:<0.001). Receiver operator curves revealed the utility of the scaling exponent for predicting the probability of restoring an organized rhythm (area under the curve=0.70) and of survival (area under the curve=0.84). CONCLUSIONS: -The VF waveform in OOHCA can be quantified with the scaling exponent, which predicts the probability of first-shock defibrillation and survival to hospital discharge.


Asunto(s)
Cardioversión Eléctrica/métodos , Paro Cardíaco/terapia , Fibrilación Ventricular/terapia , Anciano , Reanimación Cardiopulmonar/estadística & datos numéricos , Cardioversión Eléctrica/instrumentación , Electrocardiografía , Urgencias Médicas , Femenino , Fractales , Paro Cardíaco/diagnóstico , Paro Cardíaco/etiología , Frecuencia Cardíaca , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Alta del Paciente/estadística & datos numéricos , Policia/educación , Pronóstico , Curva ROC , Procesamiento de Señales Asistido por Computador , Tasa de Supervivencia , Fibrilación Ventricular/complicaciones , Fibrilación Ventricular/diagnóstico
12.
Cardiovasc Res ; 33(3): 601-10, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9093530

RESUMEN

OBJECTIVES: Plasma endothelin (ET) concentrations are increased in heart failure. The aims of the present study were to investigate to what extent cardiac ET mRNA expression is induced in ischemic heart failure and whether there may be compensatory downregulation of myocardial mRNA levels for the ETA and ETB receptor subtypes. METHODS: In rats with ischemic heart failure (left ventricular end-diastolic pressure > 15 mmHg) due to left coronary artery ligation. Northern blot analyses were performed on mRNA isolated from cardiac tissues. RESULTS: A substantial upregulation was revealed in all chambers of the failing hearts. Up to 27-fold upregulation (mean 10.6 +/- 4.0, P = 0.002) of left ventricular ET-1 mRNA levels was measured 1 week after myocardial infarction, whereas only a modest upregulation was detected after 6 weeks (mean 2.7 +/- 0.5, P < 0.05). Ribonuclease protection assay revealed 2.8 +/- 0.4-fold higher levels of ET-1 mRNA in the left ventricular area subjected to myocardial infarction compared to the non-infarcted tissue after 1 week. Left ventricular ET-1 mRNA correlated significantly with left ventricular end-diastolic pressure after 1 week (r2 = 0.86, P = 0.007). The ETA and ETB receptor mRNA levels tended to increase 1 week after myocardial infarction although these changes were not statistically significant. CONCLUSIONS: Cardiac ET-1 mRNA levels are increased in ischemic heart failure and correlate significantly with left ventricular end-diastolic pressure 1 week after myocardial infarction. The increase in cardiac ET-1 mRNA is not accompanied by a decrease in ET receptor mRNA.


Asunto(s)
Endotelina-1/genética , Isquemia Miocárdica/metabolismo , Miocardio/metabolismo , ARN Mensajero/metabolismo , Animales , Northern Blotting , Masculino , Infarto del Miocardio/metabolismo , ARN Mensajero/análisis , Ratas , Ratas Wistar , Receptores de Endotelina/metabolismo , Volumen Sistólico
13.
AIDS ; 7(9): 1255-9, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8216984

RESUMEN

OBJECTIVE: To determine whether deaths among Haitian infants born to HIV-1-seronegative women could be distinguished from deaths among children born to HIV-1-seropositive women using the verbal autopsy technique. METHODS: Mothers of 315 Haitian children who died were interviewed about events leading to the child's death. Three physicians independently reviewed interview data and determined the probable cause of death without knowledge of maternal HIV-1 status or hospital records. The underlying causes of death assigned to the infants were analyzed to determine whether maternal HIV status could be predicted. RESULTS: There was good agreement among the physicians (kappa = 0.62) and 90% agreement between hospital records and the verbal autopsy diagnosis. Compared with children born to HIV-1-seronegative women, deaths in children born to HIV-1-seropositive mothers were more likely to be ascribed to a presumptive diagnosis of AIDS (37 versus 21%; P = 0.01). The sensitivity and specificity of verbal autopsies for identifying deaths associated with maternal HIV-1 infection ranged from 37 to 59% and from 69 to 79%, respectively, depending on the classification system used. The predictive positive value of a death believed to be consistent with pediatric HIV-1 infection was 26-30% and the predictive negative value was 85-90%. CONCLUSION: Verbal autopsies may be useful for distinguishing certain causes of death, but have limited utility for distinguishing deaths associated with maternal HIV-1 infection from deaths among children born to HIV-1-seronegative women.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/mortalidad , Síndrome de Inmunodeficiencia Adquirida/patología , Autopsia/métodos , Causas de Muerte , Preescolar , Femenino , Seropositividad para VIH , Haití/epidemiología , Humanos , Lactante , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Sensibilidad y Especificidad
14.
Artículo en Inglés | MEDLINE | ID: mdl-2352124

RESUMEN

Pregnant Haitian women (n = 4,474) residing in a periurban slum were interviewed to identify risk factors for sexually transmitted diseases and sera were tested to identify antibodies to HIV-1 and syphilis. The seroprevalence rates for antibodies to HIV-1 increased from 8.9% in 1986 to 9.9% in 1987 and 10.3% in 1988. Sera obtained in 1982 from 533 mothers of young infants in the same community revealed that 7.8% were HIV-1 seropositive. Of women pregnant for the first time in 1986-1988, 6.6% were HIV-1 seropositive and 6.0% had a positive VDRL. The highest seropositivity rates (greater than 15%) were noted in women 20 to 29 years of age with a history of two or more sexual partners in the year prior to pregnancy. Factors independently associated with HIV-1 seropositivity in pregnant women by logistic regression analysis included being unmarried, age 20-29 years, having had more than one sex partner in the year prior to pregnancy, a positive serologic test for syphilis, and smoking. A dose-response effect was noted in the association between HIV-1 seropositivity and smoking. The association between smoking and HIV-1 infections could be confounded by unrecognized behavioral factors or due to a biologic effect of smoking. The continuing high HIV-1 seropositivity rates in pregnant women indicate that current preventive measures are insufficient and increased control efforts are urgently needed.


Asunto(s)
Seroprevalencia de VIH , Complicaciones Infecciosas del Embarazo/epidemiología , Western Blotting , Ensayo de Inmunoadsorción Enzimática , Femenino , Haití/epidemiología , Humanos , Matrimonio , Pobreza , Embarazo , Análisis de Regresión , Estudios Retrospectivos , Factores de Riesgo , Parejas Sexuales , Fumar , Sífilis/complicaciones , Sífilis/epidemiología , Serodiagnóstico de la Sífilis , Población Urbana
15.
Mol Biochem Parasitol ; 27(1): 23-34, 1988 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-2830508

RESUMEN

N-Acetylneuraminic acid (NeuNAc) is the terminal sugar residue of the O-linked tetrasaccharide linked to erythrocyte sialoglycoproteins, glycophorins. Erythrocytes lacking NeuNAc have been shown previously to be resistant to invasion by certain isolates of Plasmodium falciparum merozoites. We report here variation between different geographic isolates of P. falciparum in their dependency on NeuNAc for invasion of host erythrocytes. Seven different geographic isolates of P. falciparum were examined for their ability to invade neuraminidase treated erythrocytes. For all isolates invasion was reduced significantly, although considerable variation in NeuNAc dependency was apparent. Three isolates, FCR-3, FVO and It2, exhibited a very high dependence on NeuNAc residues for invasion (invasion reduced greater than 90%), whereas two isolates (Thai-Tn and FC-27) exhibited a moderately high dependence (invasion reduced 75%). Two other isolates (CDC-1 and 7G8) exhibited moderate dependence on NeuNAc (invasion reduced 50%). Cleavage of the complete O-linked tetrasaccharide by O-glycanase removes all carbohydrate from glycophorin A, B and C except the single N-linked oligosaccharide on glycophorin A and C. Invasion of FCR-3 and CDC-1 isolates into O-glycanase treated erythrocytes was not markedly different from that into neuraminidase treated cells indicating that NeuNAc is the important residue of the tetrasaccharide for both isolates. Invasion into endo-beta-galactosidase treated erythrocytes, in which the lactosaminoglycan side chain of band 3 and band 4.5 is cleaved, was not significantly reduced for either the CDC-1 or FCR-3 isolates. Additional results on the trypsin insensitivity of band 3 also suggest that this erythrocyte protein is not important in P. falciparum recognition. The greatest divergence in receptor specificity between FCR-3 and CDC-1 isolates was apparent in invasion into periodate-treated erythrocytes. Periodate oxidation results in cleavage of the exocyclic hydroxyl groups of the terminal NeuNAc but leaves its COOH group unaltered. These experiments also illustrated that the negatively charged COOH group of NeuNAc is not the important group in the interaction of the merozoite with the NeuNAc. Trypsin-treated erythrocytes were almost fully resistant to invasion by CDC-1 as well as the FCR-3 isolates suggesting that the CDC-1 isolate, in addition to interacting with NeuNAc, depends on a trypsin sensitive site for invasion. This site could involve the N-linked saccharide on glycophorin A and C or a protein on the erythrocyte surface unrelated to the glycophorins.


Asunto(s)
Eritrocitos/parasitología , Glicoforinas/metabolismo , Plasmodium falciparum/metabolismo , Sialoglicoproteínas/metabolismo , Animales , Sitios de Unión , Fenómenos Químicos , Química , Electroforesis en Gel de Poliacrilamida , Eritrocitos/análisis , Eritrocitos/efectos de los fármacos , Glicósido Hidrolasas/farmacología , Humanos , Ácido N-Acetilneuramínico , Neuraminidasa/farmacología , Ácido Peryódico/farmacología , Ácidos Siálicos/metabolismo , Tripsina/farmacología
16.
J Med Chem ; 30(5): 780-8, 1987 May.
Artículo en Inglés | MEDLINE | ID: mdl-3572967

RESUMEN

Several members of the heterocyclic family 3-selena-7-azabicyclo[3.3.1]nonane have been synthesized and characterized via IR, 1H, 13C, 15N, and 77Se NMR spectroscopy and, in some cases, by X-ray diffraction analysis. Select members, namely the hydroperchlorates of the amines, were examined for antiarrhythmic properties in anesthetized dogs in which myocardial infarctions were induced by techniques previously described. In the predrug, or control state, sustained ventricular tachycardia were induced by ventricular paced beats at rates above 300/min. When 7-benzyl-3-selena-7-azabicyclo[3.3.1]nonane hydroperchlorate was administered at 3 and 6 mg/kg, the sustained ventricular tachycardia could no longer be induced. Similar doses of lidocaine, a commonly used antiarrhythmic, caused slowing of the sustained ventricular tachycardia below 300/min but did not abolish their inducibility. In addition, select members of the hydroperchlorates caused a moderate 10-20% increase in mean blood pressure whereas lidocaine caused either no change in or slightly reduced mean blood pressure. Some general conclusions are delineated concerning the structural requirements that appear to be necessary for activity in this family of heterocycles and that have not been reported previously.


Asunto(s)
Arritmias Cardíacas/tratamiento farmacológico , Compuestos Bicíclicos con Puentes/uso terapéutico , Hidrocarburos Aromáticos con Puentes/uso terapéutico , Selenio/uso terapéutico , Animales , Compuestos Bicíclicos con Puentes/síntesis química , Fenómenos Químicos , Química , Química Física , Perros , Lidocaína/uso terapéutico , Espectroscopía de Resonancia Magnética , Conformación Molecular , Taquicardia/tratamiento farmacológico , Difracción de Rayos X
17.
J Med Chem ; 28(1): 116-24, 1985 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2578190

RESUMEN

There is reported the first four members of heteroarotinoids, the names of which are ethyl (E)-p-[2-(4,4-dimethylthiochroman-6-yl)propenyl]benzoate (1b), ethyl (E)-p-[2-(4,4-dimethylchroman-6-yl)propenyl]benzoate (1c), ethyl (E)-p-[2-(4,4-dimethyl-1-oxothiochroman-6-yl)propenyl]benzoate (1d), and (E)-p-[2-(4,4-dimethylchroman-6-yl)propenyl]benzoic acid (1e). IR, 1H NMR and 13C NMR data have been recorded for each compound and support the structural assignments. To provide a firm basis for comparison purposes of future analogues, an X-ray analysis was performed on a single crystal of ethyl (E)-p-[2-(4,4-dimethylthiochroman-6-yl)propenyl]benzoate (1b) and a precursor 4,4-dimethylthiochroman-6-yl methyl ketone 1,1-dioxide (18). These data for the heteroarotinoid 1b revealed that the two aryl ring systems were nearly perpendicular in each of the two molecules present in the unit cell (86.37 degrees and 84.17 degrees, respectively). The space group for both molecules was P1 in triclinic systems. Unit cell dimensions (at 15 degrees C) are as follows: for 1b, a = 20.568 (6) A, b = 14.760 (3) A, c = 7.679 (2) A, alpha = 113.33 (2) degrees, beta = 79.45 (2) degrees, gamma = 79.98 (2) degrees, Z = 4; for 18, a = 9.292 (5) A, b = 9.291 (5) A, c = 7.951 (3) A, alpha = 102.16 (3) degrees, beta = 77.49 (3) degrees, gamma = 79.60 (4) degrees, Z = 2. The sulfur-containing ring is in a distorted half-chair in 1b and the methyl carbon C(12) is shown to be trans to H(13) at the C(11)-C(13) bond. The biological activity of these arotinoids was determined in the tracheal organ culture assay and compared with trans-retinoic acid for ability to reverse keratinization in vitamin A deficient hamsters. The ester 1b displayed activity about one-half log unit less than that of the reference while 1c and 1e had activity nearly one log until less than trans-retinoic acid. The sulfoxide was the least active of the heteroretinoids.


Asunto(s)
Benzopiranos/síntesis química , Cromanos/síntesis química , Tráquea/efectos de los fármacos , Deficiencia de Vitamina A/metabolismo , Animales , Cromanos/farmacología , Cricetinae , Queratinas/metabolismo , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Técnicas de Cultivo de Órganos , Tráquea/metabolismo , Difracción de Rayos X
18.
J Med Chem ; 27(6): 758-67, 1984 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-6737418

RESUMEN

The synthesis of the title ketone has been completed via a type of Mannich reaction starting from 4- thianone . An X-ray diffraction analysis has revealed that the solid system is a chair-boat conformer with the sulfur atom in the boat portion of the bicyclic ring compound. Wolff- Kishner reduction of the ketone group gave 7-benzyl-3-thia-7-azabicyclo [3.3.1]nonane, which was isolated as the hydroperchlorate . However, X-ray diffraction analysis of the salt showed this solid to be a chair-chair conformer. Addition of phenylmagnesium bromide to the ketone gave a tertiary alcohol with the C-C6H5 bond being equatorial with respect to the thiane ring and axial with respect to the piperidine ring. The reaction of the Grignard reagent with the ketone to give this alcohol seems to be very stereospecific. An X-ray analysis of the hydroperchlorate of the alcohol confirmed the system to be a chair-chair form in the solid. The title compounds were screened for antiarrhythmic activity in anesthetized mongrel dogs in which myocardial infarctions had been created when the left anterior descending coronary artery was ligated. Vagal-induced slowing of the sinus mode firing rate was used to determine the underlying ventricular automaticity in the dogs, which averaged 164 +/- 27 beats/min. Ventricular pacing was initiated to rates between 240 and 390/min. This technique resulted in the induction of rapid and sustained ventricular tachycardia. At doses of 3 and 6 mg/kg of body weight, 7-benzyl-3-thia-7-azabicyclo [3.3.1]nonane hydroperchlorate in alcohol (the solution was administered intravenously) was able to suppress markedly the induced ventricular tachycardia in five of six dogs. The compound also caused a 10-15% increase in blood pressure within a few minutes. The antiarrhythmic properties of this compound and others of related structure are discussed, and some comparison is made with the action of lidocaine in similar dog preparations.


Asunto(s)
Antiarrítmicos/síntesis química , Compuestos Bicíclicos Heterocíclicos con Puentes , Compuestos Bicíclicos con Puentes/síntesis química , Hidrocarburos Aromáticos con Puentes/síntesis química , Animales , Compuestos Bicíclicos con Puentes/farmacología , Cristalización , Perros , Frecuencia Cardíaca/efectos de los fármacos , Lidocaína/farmacología , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Estereoisomerismo , Difracción de Rayos X
19.
Pediatrics ; 98(6 Pt 1): 1076-83, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8951256

RESUMEN

OBJECTIVE: This article describes the results of a community-based study to determine the effect of family knowledge and attitudes on the immunization rates of a random sample of children younger than 2 years in the poorest census tracts of Baltimore. DESIGN AND METHODS: The two sources of data were (1) parent interviews that provided data on knowledge, attitudes, and beliefs related to immunization and sociodemographic characteristics, and (2) medical record audits from which data on immunization status were obtained. The protection motivation theory, a model of behavioral change, was used to select the variables to assess the relation of parental attitudes with immunization status. A multivariate logistic regression analysis included only variables found to be significantly associated with immunization outcome in the preliminary analysis. RESULTS: Mothers were well informed and generally had favorable attitudes toward immunizations. Immunization status was more strongly associated with the sociodemographic characteristics of the children than with the protection motivation theory variables. Only two protection motivation theory variables were associated with more than one immunization outcome. The children of mothers who perceived that timing of vaccination did not matter were less likely to be immunized than children of care takers who thought that it did matter and children whose parents believed in the safety of multiple immunizations were less likely to be immunized than children whose parents did not hold this belief. CONCLUSIONS: In this study, parents' attitudes and beliefs had little effect on their children's immunization levels. Interventions intended to heighten parental awareness about immunization may have little impact. In poor urban neighborhoods, African-American children whose mothers are young, have multiple siblings, and do not use the Women, Infants and Children program may be at highest risk for delayed immunization.


Asunto(s)
Actitud Frente a la Salud , Inmunización/psicología , Padres/psicología , Adulto , Baltimore , Estudios de Cohortes , Familia , Femenino , Humanos , Lactante , Masculino , Edad Materna , Pobreza , Distribución Aleatoria
20.
Pediatrics ; 85(2): 188-94, 1990 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2296506

RESUMEN

To evaluate the impact of measles vaccination on survival of children residing in a periurban slum in Haiti, a total-population survey was conducted 2.5 years after completion of a one-time study of the serologic response to measles vaccine administered in the same population. Pregnancy histories from the 16,400 women in the population revealed that 1499 children had been born during a 7-month interval that would have made them eligible for participation in the measles vaccine program. Of these children, 1381 (92.1%) survived to 9 months of age, the median age that measles vaccine had been administered. Seventy-three infants had died between 9 and 39 months of age. Mortality of infants who were seronegative before receiving measles vaccine was significantly lower (P = .0013) than that of unvaccinated infants (3/235 vs 70/1056, respectively). Other factors positively associated with survival between 9 and 39 months of age included socioeconomic status (P = .0002), maternal literacy (P = .0020), maternal knowledge and use of oral rehydration solution (P = .0002), and an interval of greater than 24 months to the birth of the next younger sibling (P = .0012). Multivariate stepwise logistic regression analysis was used to evaluate the independent association of measles vaccination by adjusting for other factors that also correlated with survival and that might have been associated with maternal seeking of vaccinations.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Mortalidad Infantil , Vacuna Antisarampión , Sarampión/prevención & control , Preescolar , Estudios de Cohortes , Haití/epidemiología , Humanos , Lactante , Sarampión/mortalidad , Análisis Multivariante , Oportunidad Relativa , Áreas de Pobreza , Factores Socioeconómicos , Análisis de Supervivencia , Vacunación
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