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1.
Electromagn Biol Med ; 28(2): 135-47, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19811396

RESUMEN

All bio-systems are imperfect dielectrics. Their general properties however cannot be described by conventional simple electrodynamics; the system is more complex. A central question in our present paper is centered on a controversial debate of the possible effect of the zero fields (only potentials exist). We show that the identical use of the "field-free," "curl-free," and "force-free" terminologies is incorrect, there have definitely different meanings. It is shown that the effective electro-dynamical parameters that describe and modify living systems are the potentials and not the fields. We discuss how the potentials have a role in biological processes even in field-free cases.


Asunto(s)
Fenómenos Electromagnéticos , Modelos Biológicos , Fenómenos Biológicos , Humanos
2.
Electromagn Biol Med ; 28(2): 166-81, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19811398

RESUMEN

Living objects are complex systems with various harmonized chemical, thermodynamical, and quantum-mechanical processes in aqueous electrolyte environment. We had studied the effect of curl-free magnetic vector-potential on the matrix of the living matter, on the water. The discussed theoretical considerations are in harmony with the presented simple experiments. It is shown that the vector-potential is actually an effective electro-dynamical parameter which could modify the processes in living systems.


Asunto(s)
Fenómenos Electromagnéticos , Agua , Absorción , Humanos , Modelos Biológicos , Fenómenos Ópticos
3.
Bioelectromagnetics ; 29(5): 380-6, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18288680

RESUMEN

Despite experimental evidence supporting ICR-like interactions in biological systems, to date there is no reasonable theoretical explanation for this phenomenon. The parametric resonance approach introduced by Lednev has enjoyed limited success in predicting the response as a function of the ratio of AC magnetic intensity to that of the DC field, explaining the results in terms of magnetically induced changes in the transition probability of calcium binding states. In the present work, we derive an expression for the velocity of a damped ion with arbitrary q/m under the influence of the Lorentz force. Series solutions to the differential equations reveal transient responses as well as resonance-like terms. One fascinating result is that the expressions for ionic drift velocity include a somewhat similar Bessel function dependence as was previously obtained for the transition probability in parametric resonance. However, in the present work, not only is there an explicit effect due to damping, but the previous Bessel dependence now occurs as a subset of a more general solution, including not only the magnetic field AC/DC ratio as an independent variable, but also the ratio of the cyclotronic frequency Omega to the applied AC frequency omega. In effect, this removes the necessity to explain the ICR interaction as stemming from ion-protein binding sites. We hypothesize that the selectively enhanced drift velocity predicted in this model can explain ICR-like phenomena as resulting from increased interaction probabilities in the vicinity of ion channel gates.


Asunto(s)
Canales de Calcio/química , Canales de Calcio/efectos de la radiación , Calcio/química , Calcio/efectos de la radiación , Iones , Modelos Químicos , Sitios de Unión/efectos de la radiación , Simulación por Computador , Campos Electromagnéticos
4.
Curr Med Res Opin ; 24(3): 795-805, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18252038

RESUMEN

OBJECTIVES: Most patients with hypertension need combination therapy to reach adequate blood pressure control. The objective of this study was to assess type, duration of, and adherence to antihypertensive therapies among veterans, focusing on the use of combination therapies. RESEARCH DESIGN AND METHODS: The design of the study was a retrospective cohort analysis of electronic medical and pharmacy records from the Central Texas Veterans Health Care System (CTVHCS). Data were extracted for adults newly identified with hypertension between 1995 and 2003. Drug utilization was measured as a time-dependent variable; thus, the use of combination therapies was captured for any given day for each patient in the sample. Medication adherence was assessed using medication possession ratios (MPR), calculated by the number of days of therapy dispensed to a patient divided by the number of days between subsequent prescriptions. RESULTS: The average age of the participants (n = 11 187) was 60.7 (standard deviation (SD): 12.7). Half (50.1%) of the patients could be categorized as having controlled blood pressure. Veterans were followed for an average of 3.6 years (total of 51 549 person-years). Overall, 29 561 treatment episodes were identified, an average of about 2.6 per patient. Over 40% (41.6%) of these episodes involved one medication only, but patients frequently used dual (26.9%) and three or more (15.9%) therapies in combination. The frequency of prescribed antihypertensive therapies, as well as the length of, and adherence to, these therapies were described. Descriptively, medication adherence appeared to be lower among patients who received therapy for longer duration, indicating higher probability of missed doses and more frequent therapy changes. CONCLUSIONS: New information can be gained on the utilization of antihypertensive medications by using time-dependent variables. Understanding the type of combination therapies, the length of and adherence to these therapies, along with the observed blood pressure control rates will provide important new insights into the management of hypertensive patients. Limitations of the study arise primarily from the use of electronic medical records and the information that is contained within the datasource, and generalizability of the findings beyond the study sample.


Asunto(s)
Antihipertensivos/uso terapéutico , Hipertensión/tratamiento farmacológico , Cooperación del Paciente/estadística & datos numéricos , Veteranos , Antagonistas Adrenérgicos beta/uso terapéutico , Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Quimioterapia Combinada , Utilización de Medicamentos , Femenino , Humanos , Masculino , Sistemas de Registros Médicos Computarizados , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Estados Unidos
5.
J Hum Hypertens ; 22(2): 132-4, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17728802

RESUMEN

Using a retrospective cohort design and electronic medical records, we examined chronic kidney disease (CKD) risk over a 6-year period among hypertensive patients in relation to the presence of diabetes, hyperlipidaemia and/or high body mass index. After adjusting for age, sex, smoking status and baseline glomerular filtration rate (GFR), hypertensive patients without other metabolic risk factors had a relative risk of CKD (versus normotensive patients) of 2.0 (95% CI 1.8-2.2); hypertensive patients with other metabolic conditions had adjusted relative risks ranging from 2.4 to 2.6 for those without comorbid diabetes, and from 3.3 to 5.5 for those with comorbid diabetes. Our study thus confirms prior research demonstrating elevated CKD risk in hypertensive patients, and suggests that this risk varies substantially in relation to other metabolic conditions, especially diabetes.


Asunto(s)
Hipertensión/complicaciones , Enfermedades Renales/etiología , Enfermedades Metabólicas/complicaciones , Índice de Masa Corporal , Enfermedad Crónica , Complicaciones de la Diabetes , Femenino , Tasa de Filtración Glomerular , Humanos , Hiperlipidemias/complicaciones , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo
7.
J Hum Hypertens ; 21(5): 374-80, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17314999

RESUMEN

In the Valsartan Antihypertensive Long-Term Use Evaluation (VALUE) trial, the risk of new-onset diabetes was reported to be 23% lower among patients initiating therapy with valsartan versus amlodipine. The objective of our study was to examine whether this finding is generalizable to 'real-world' clinical practice. A retrospective cohort design and a large US health insurance database were employed for analyses. Study subjects included all hypertensive patients, aged >or=35 years, who were free from diabetes and who initiated treatment with valsartan (n=9999) or amlodipine (n=18 698) between January 1999 and March 2005. Unadjusted absolute risks of diabetes were 21.4 (95% confidence interval (CI) 18.9-24.3) and 26.3 (95% CI 24.3-28.3) per 1000 patient-years for valsartan and amlodipine, respectively; the corresponding relative risk (RR) for valsartan was 0.82 (95% CI 0.70-0.94). Multivariate analyses - controlling for age, sex, presence of hypercholesterolemia, cardiovascular disease and kidney disease, and pretreatment medical care expenditures - yielded similar results (RR=0.79, 95% CI 0.68-0.92). Our study thus corroborates the finding from VALUE that diabetes risk is lower for patients who receive valsartan versus amlodipine, and extends this finding to a 'real-world' setting.


Asunto(s)
Amlodipino/uso terapéutico , Antihipertensivos/uso terapéutico , Diabetes Mellitus/inducido químicamente , Diabetes Mellitus/epidemiología , Hipertensión/tratamiento farmacológico , Tetrazoles/uso terapéutico , Valina/análogos & derivados , Adulto , Anciano , Antihipertensivos/efectos adversos , Bases de Datos Factuales , Diabetes Mellitus/prevención & control , Diabetes Mellitus Tipo 2/inducido químicamente , Diabetes Mellitus Tipo 2/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Conducta de Reducción del Riesgo , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos/epidemiología , Valina/uso terapéutico , Valsartán
8.
Psychiatr Genet ; 15(1): 1-6, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15722950

RESUMEN

Since the function and metabolism of peripheral lymphocytes is known to be altered in Alzheimer's disease (AD), a pilot study was carried out to examine differences in gene expression profiles of these cells in 16 AD patients and aged control probands. Using a cDNA microarray representing 3200 distinct human genes, we identified 20 candidate genes whose expression is altered in AD lymphocytes compared with the control probands. Among these were the alpha2C-adrenoreceptor gene, known to regulate blood pressure and learning, the defensin, histocompability complex enhancer-binding protein, carboxypeptidase M, and the Fc fragment of IgE known to be involved in cellular and humoral immune responses. Others, like human cell death protein, TRAIL, and galectin-4 participate in the regulation of apoptosis. Real-time quantitative reverse transcription-polymerase chain reaction analysis was performed in order to confirm the expression changes in AD lymphocytes, and it could detect down-regulation of defensin and alpha2c-adrenoceptor genes, while other genes seemed unaltered in their expression, including heat-shock protein (hsp90), cholesteryl ester transfer protein, and apolipoprotein B100 (apoB). The altered expression profile of these genes might be connected with the previously reported AD-specific lymphocyte abnormalities. It remains to be elucidated, however, how these genes are related to the pathomechanism of dementia and whether the gene expression differences of AD lymphocytes reflect disease traits or stage processes.


Asunto(s)
Enfermedad de Alzheimer/genética , Perfilación de la Expresión Génica , Linfocitos/fisiología , Anciano , Apolipoproteína B-100 , Apolipoproteínas B/genética , Cartilla de ADN , Hogares para Ancianos , Humanos , Proteínas del Tejido Nervioso/genética , Casas de Salud , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa
9.
Skin Pharmacol Physiol ; 17(4): 195-9, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15258451

RESUMEN

BACKGROUND: Antipsychotics are widely used in the treatment of behavioral and psychological symptoms of dementia. A low frequency of Alzheimer's disease in patients with schizophrenia is reported, and it has been proposed that antipsychotic medications, such as haloperidol, may be responsible. Disruption of intracellular calcium levels is considered to play a key role in beta-amyloid-induced neurotoxicity in Alzheimer's disease. Haloperidol has also been reported to interact with calcium homeostasis through dopamine-2 and sigma-1 receptors, and other, yet unknown mechanisms. OBJECTIVE: Therefore, we investigated whether differences in the basal intracellular free calcium levels of cultured cutaneous fibroblasts--cells that do not express dopamine-2 and sigma-1 receptors--derived from sporadic Alzheimer patients and from age-matched control individuals after haloperidol treatment might be present. METHODS: Intracellular calcium level was measured in Fura-2AM-loaded human fibroblasts by dual wavelength spectrofluorimetry. RESULTS: Alzheimer cells exhibited significantly lower calcium level as compared to the control cultures. Exposure of fibroblasts to beta-amyloid peptide resulted in increased calcium concentration of the control cells, but not of Alzheimer fibroblasts. Co-incubation of cultures with a therapeutic dose of haloperidol blocked the beta-amyloid-induced elevation of calcium. CONCLUSION: This finding indicates that haloperidol efficiently countervails ionic imbalance and suggests that it may serve as a potential agent in alleviating neurotoxic effects of beta-amyloid peptide.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Antipsicóticos/farmacología , Calcio/metabolismo , Fibroblastos/efectos de los fármacos , Haloperidol/farmacología , Anciano , Anciano de 80 o más Años , Calcio/análisis , Células Cultivadas , Fibroblastos/metabolismo , Humanos , Espectrometría de Fluorescencia
10.
Eur Biophys J ; 30(3): 227-31, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11508842

RESUMEN

Pink (1/f) noise is one of the most common behaviours of biosystems. Our present paper is devoted to clarify the origin of this interesting phenomenon. It is shown that the stationary random stochastic processes under self-similar conditions (as we have in living objects) generate pink noise independently of the kind and number of variables.


Asunto(s)
Biofisica/métodos , Fractales , Modelos Estadísticos , Procesos Estocásticos
12.
Acta Biol Hung ; 45(1): 17-23, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7740896

RESUMEN

Pseudomonas strains were isolated from a heavy metal contaminated sludge. Some of the strains grew on chromium (VI) containing medium, and others were inhibited in their growth. Cells were able to remove chromium from the medium. This ability was independent of the rate of their growth. The concentration of chromium (VI) of the media decreased with 15-20 ppm in presence of 10(9) cells. The chromium (VI) was converted into a reduced form of chromium by bacteria. The reduced form of chromium was bound in the cell wall. The bound form of chromium could be recovered more or less with different chemicals. The best percentages of recovery were achieved with NaOH solution.


Asunto(s)
Cromo/farmacología , Pseudomonas/efectos de los fármacos , Transporte Biológico Activo , Cromo/farmacocinética , Recuento de Colonia Microbiana , Medios de Cultivo , Farmacorresistencia Microbiana , Pseudomonas/crecimiento & desarrollo , Pseudomonas/metabolismo , Contaminantes Químicos del Agua/metabolismo , Contaminantes Químicos del Agua/farmacología
13.
Photosynth Res ; 21(2): 123-8, 1989 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24424531

RESUMEN

Cell-free preparations from the green alga, Chlorella pyrenoidosa, contained two forms of phosphofructokinase (PFK), designated PFK I and PFK II. This represents the first evidence for a second form of PFK in green algae. A pyrophosphate D-fructose-6-phosphate, 1-phosphotransferase (PFP) activity, that was unaffected by the regulatory metabolite, fructose-2,6-bisphosphate, co-purified with PFK II through several steps. The data suggest that Chlorella pyrenoidosa resembles higher plants in containing two forms of PFK, but differs in containing an atypical form of PFP.

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