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1.
Nanoscale ; 7(13): 5726-36, 2015 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-25743890

RESUMO

Understanding the interaction of proteins with charged diamond nanoparticles is of fundamental importance for diverse biomedical applications. Here we present a thorough study of protein binding, adsorption kinetics and structure on strongly positively (hydrogen-terminated) and negatively (oxygen-terminated) charged nanodiamond particles using a quartz crystal microbalance by dissipation and infrared spectroscopy. By using two model proteins (bovine serum albumin and lysozyme) of different properties (charge, molecular weight and rigidity), the main driving mechanism responsible for the protein binding to the charged nanoparticles was identified. Electrostatic interactions were found to dominate the protein adsorption dynamics, attachment and conformation. We developed a simple electrostatic model that can qualitatively explain the observed adsorption behaviour based on charge-induced pH modifications near the charged nanoparticle surfaces. Under neutral conditions, the local pH around the positively and negatively charged nanodiamonds becomes very high (11-12) and low (1-3) respectively, which has a profound impact on the protein charge, hydration and affinity to the nanodiamonds. Small proteins (lysozyme) were found to form multilayers with significant conformational changes to screen the surface charge, while larger proteins (albumin) formed monolayers with minor conformational changes. The findings of this study provide a step forward toward understanding and eventually predicting nanoparticle interactions with biofluids.


Assuntos
Modelos Químicos , Nanodiamantes/química , Proteínas/química , Adsorção , Sítios de Ligação , Simulação por Computador , Teste de Materiais , Modelos Moleculares , Nanodiamantes/ultraestrutura , Ligação Proteica , Proteínas/ultraestrutura , Propriedades de Superfície
2.
Nanoscale ; 7(14): 5998-6006, 2015 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-25744416

RESUMO

Extracellular nucleic acids freely circulating in blood and other physiologic fluids are important biomarkers for non-invasive diagnostics and early detection of cancer and other diseases, yet difficult to detect because they exist in very low concentrations and large volumes. Here we demonstrate a new broad-range sensor platform for ultrasensitive and selective detection of circulating DNA down to the single-molecule level. The biosensor is based on a chemically functionalized nanoporous diamond-like carbon (DLC) coated alumina membrane. The few nanometer-thick, yet perfect and continuous DLC-coating confers the chemical stability and biocompatibility of the sensor, allowing its direct application in biological conditions. The selective detection is based on complementary hybridization of a fluorescently-tagged circulating cancer oncomarker (a 21-mer nucleic acid) with covalently immobilized DNA on the surface of the membrane. The captured DNAs are detected in the nanoporous structure of the sensor using confocal scanning laser microscopy. The flow-through membrane sensor demonstrates broad-range sensitivity, spanning from 10(15) molecules per cm(2) down to single molecules, which is several orders of magnitude improvement compared to the flat DNA microarrays. Our study suggests that these flow-through type nanoporous sensors represent a new powerful platform for large volume sampling and ultrasensitive detection of different chemical biomarkers.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , DNA/química , Nanoporos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Óxido de Alumínio/química , Membranas Artificiais , Sensibilidade e Especificidade
3.
Folia Microbiol (Praha) ; 56(2): 155-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21503738

RESUMO

No relation between the occurrence of antibodies to chlamydial agents and asthma in children was found. In asthmatic children, the antibodies to Chlamydia trachomatis occurred in 3.1% and to Chlamydophila pneumoniae in 22.7%, whereas in a control group of children without asthma or other allergic disease in 2.3% and 24.0%, respectively. The occurrence of antibodies of IgA and IgG classes to C. pneumoniae was also very similar; its rise was age-dependent. On the other hand, in the group of children in a pre-school age with respiratory tract infection, anti-chlamydial antibodies were demonstrated significantly more often (18.5% of IgG antibodies to C. trachomatis, 20.0% of IgM antibodies to both C. trachomatis and C. pneumoniae) than in those suffering from other, non-respiratory illness (3.9% of the former and 5.9% of the latter antibodies). However, in these children, we did not succeed in detection of C. trachomatis in conjunctival and nasopharyngeal smears by PCR. Nevertheless, chlamydial agents (C. trachomatis in infants, C. pneumoniae in pre-school children) should be taken into consideration in a differential diagnosis of respiratory tract inflammation.


Assuntos
Anticorpos Antibacterianos/sangue , Asma/imunologia , Infecções por Chlamydia/imunologia , Chlamydia trachomatis/imunologia , Chlamydophila pneumoniae/imunologia , Infecções Respiratórias/imunologia , Infecções Respiratórias/microbiologia , Adolescente , Criança , Pré-Escolar , Chlamydia trachomatis/isolamento & purificação , Chlamydophila pneumoniae/isolamento & purificação , Túnica Conjuntiva/microbiologia , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Nasofaringe/microbiologia
4.
Nanotechnology ; 21(41): 415604, 2010 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-20844323

RESUMO

Silicon nanowires and nanoneedles show promise for many device applications in nanoelectronics and nanophotonics, but the remaining challenge is to grow them at low temperatures on low-cost materials. Here we present plasma-enhanced chemical vapor deposition of crystalline/amorphous Si nanoneedles on glass at temperatures as low as 250 °C. High resolution electron microscopy and micro-Raman spectroscopy have been used to study the crystal structure and the growth mechanism of individual Si nanoneedles. The H(2) dilution of the SiH(4) plasma working gas has caused the formation of extremely sharp nanoneedle tips that in some cases do not contain a catalytic particle at the end.

5.
Nanotechnology ; 21(6): 065302, 2010 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-20057035

RESUMO

Many large molecular complexes are limited in thin film applications by their insufficient thermal stability, which excludes deposition via commonly used vapour phase deposition methods. Here we demonstrate an alternative way of monolayer formation of large molecules by a simple spray coating method under ambient conditions. This technique has been successfully applied on C(60) dissolved in toluene and carbon disulfide. Monolayer thick C(60) films have been formed on graphite and gold surfaces at particular deposition parameters, as confirmed by atomic force and scanning tunnelling microscopies. Structural and electronic properties of spray coated C(60) films on Au(111) have been found comparable to thermally evaporated C(60). We attribute the monolayer formation in spray coating to a crystallization process mediated by an ultrathin solution film on a sample surface.

6.
Kidney Int ; 54(5): 1652-8, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9844141

RESUMO

BACKGROUND: Renal kallikrein excretion is diminished in essential hypertension, especially in African-Americans, and evidence exists for a major gene effect on the kallikrein phenotype. In addition, urinary kallikrein excretion differs by gender, with ovulating females having greater kallikrein excretion than males or postmenopausal females. Recent studies have shown that renal kallikrein excretion varies in females during the ovulatory cycle, with levels rising during the luteal phase and returning during the follicular phase to levels that are similar to those of males. In family studies, gender differences in urinary kallikrein excretion were present in white subjects, but not black subjects. We therefore hypothesized dysregulation of kallikrein biosynthetic responses in African-Americans. METHODS: We determined urinary kallikrein activity [chromogenic substrate S2266 (D-val-leu-arg-paranitroanilide) assay; in microU/mg creatinine] in white (N = 15) and black (N = 11) ovulating females during the ovulatory cycle. Serum progesterone, estrogen, plasma renin activity as well as urinary aldosterone, and urinary electrolytes were determined to investigate changes between mid-follicular and mid-luteal phases in the two groups. RESULTS: White and black groups were matched for age, body mass index, blood pressure, heart rate and renal function. Ovulatory cycle phases were confirmed by serum progesterone determinations, which increased significantly in whites and blacks to a comparable degree [0.84 +/- 0.14 nmol/liter (mid-follicular) to 29.77 +/- 4.70 nmol/liter (mid-luteal) in whites, 0.67 +/- 0.08 nmol/liter (mid-follicular) to 28.62 +/- 5.83 nmol/liter (mid-luteal) in blacks; P < 0.001 for cycle effect, P = NS for race effect and race X cycle interaction]. Urinary kallikrein activity increased from 623 +/- 86 microU/mg creatinine (mid-follicular) to 948 +/- 142 microU/mg creatinine (mid-luteal) in whites, but did not change in blacks during the ovulatory cycle [239 +/- 73 microU/mg creatinine (mid-follicular] to 244 +/- 41 microU/mg creatinine (mid-luteal)]. Two-way ANOVA revealed significant effects on urinary kallikrein for race (P < 0.001), cycle (P < 0.05), and race X cycle interaction (P < 0.05). Thus, white females had higher urinary kallikrein than black females, and demonstrated a significant increase in urinary kallikrein excretion during the ovulatory cycle, whereas no significant change in urinary kallikrein activity was seen in the black group. Enzyme kinetic studies and mixing studies demonstrated that these racial differences in renal kallikrein excretion were quantitative, rather than due to qualitative differences in the renal kallikrein enzyme or due to the presence of a kallikrein inhibitor. CONCLUSIONS: These results suggest pronounced blunting of menstrual cycle changes in urinary kallikrein excretion in black females. Blunted urinary kallikrein responses during the ovulatory cycle are consistent with dysregulation of renal kallikrein biosynthetic responses in African-Americans, a group at increased risk for hypertension.


Assuntos
Calicreínas/urina , Rim/metabolismo , Ciclo Menstrual , Adulto , População Negra , Estrogênios/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Progesterona/sangue , População Branca
7.
Am J Med Genet ; 75(2): 126-37, 1998 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-9450872

RESUMO

To determine the proportion and birth prevalence of "typical" orofacial clefts (cleft lip (CL), cleft palate (CP), cleft lip and palate (CLP)) and "atypical" clefts (median, transversal, or oblique facial clefts) and the conditions in which they occur, we analyzed a population-based sample of 4,433 cases ascertained from 2,509,881 California births. We classified cases into: isolated cleft anomalies, sequences of the primary defect, chromosomal aberrations, monogenic syndromes, results of known teratogens, associations, multiple congenital anomaly (MCA) of unknown etiology, or conjoined twins. The birth prevalence of isolated CL+/-P was 0.77 per 1,000 births (CL 0.29/1,000, CLP 0.48/1,000) and of isolated CP, 0.31 per 1,000 births. Non-Hispanic Whites had the greatest prevalence of isolated clefts, Asians slightly lower prevalences, and Blacks the lowest. Asians had the lowest prevalence of Robin sequence and nonHispanic Whites the highest, twice that of Hispanics. Hispanics, followed by Asians, had the highest prevalence of CL+/-P with MCA; non-Hispanic Whites had the lowest. Asians had the lowest prevalence of CP; in Whites and Hispanics it was almost twice as high. Blacks had the highest CL:CLP ratio, followed by non-Hispanic Whites and Asians; Hispanics had the lowest. Isolated anomalies constituted 61.67% of clefts. In the total sample there were 3.9% sequences, 8.79% chromosomal aberrations, 6.02% monogenic syndromes, 0.2% known teratogens, 0.79% associations, 18.55% MCA of unknown etiology, and 0.1% in conjoined twins. This study supports evaluation of each child on a "case" level, and provides a framework for genetic counseling and other studies focused on causes and prevention of these serious anomalies.


Assuntos
Fenda Labial/classificação , Fenda Labial/epidemiologia , Fissura Palatina/classificação , Fissura Palatina/epidemiologia , California/epidemiologia , Aberrações Cromossômicas/epidemiologia , Transtornos Cromossômicos , Fenda Labial/genética , Fissura Palatina/genética , Feminino , Humanos , Recém-Nascido , Masculino , Prevalência , Sistema de Registros
8.
Hypertension ; 28(4): 599-603, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8843884

RESUMO

Abnormalities of the arterial pulse waveform reflect changes in cardiovascular structure and function. These abnormalities may occur early in the course of essential hypertension, even before the onset of blood pressure elevation. Previous studies of cardiovascular structure and function have relied on invasive intra-arterial cannulation to obtain the arterial pulse wave. We evaluated arterial structure and function using a noninvasive cuff sphygmomanometer in hypertensive (n = 15) and normotensive (n = 36) subjects stratified by genetic risk (family history) for hypertension. Using a simple physical model in which the aorta was assumed to be a T tube and the brachial artery a straight tube, we determined vascular compliance and peripheral resistance by analyzing the brachial artery pulsation signal from a cuff sphygmomanometer. Essential hypertensive subjects tended to have higher peripheral resistance (P = .06) and significantly lower vascular compliance (P = .001) than normotensive subjects. Vascular compliance correlated with simultaneously determined pulse pressure in both groups (n = 51, r = .74, P < .0001). Higher peripheral resistance (P = .07) and lower vascular compliance (P = .04) were already found in still-normotensive offspring of hypertensive parents (ie, normotensive subjects with a positive family history of hypertension) than in normotensive subjects with a negative family history of hypertension. Multivariate analysis demonstrated that both genetic risk for hypertension (P = .030) and blood pressure status (P = .041), although not age (P = .207), were significant predictors of vascular compliance (multiple R = .47, P = .011). However, by two-way ANOVA, genetic risk for hypertension was an even more significant determinant (F = 7.84, P = .007) of compliance than blood pressure status (F = 2.69, P = .089). Antihypertensive therapy with angiotensin-converting enzyme inhibitors (10 days, n = 10) improved vascular compliance (P = .02) and reduced resistance (P = .003) significantly; treatment with calcium channel antagonists (4 weeks, n = 8) tended to improve vascular compliance (P = .07) and significantly reduced peripheral resistance (P = .006). We conclude that arterial vascular compliance abnormalities detected by a noninvasive cuff sphygmomanometer reflect treatment-reversible changes in vascular structure and function. Early changes in vascular compliance in still-normotensive individuals at genetic risk for hypertension may be a heritable pathogenetic feature of this disorder.


Assuntos
Artérias/fisiopatologia , Hipertensão/fisiopatologia , Adulto , Idoso , Determinação da Pressão Arterial , Complacência (Medida de Distensibilidade) , Feminino , Humanos , Hipertensão/genética , Masculino , Pessoa de Meia-Idade , Resistência Vascular
9.
Nat Genet ; 12(3): 315-7, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8589725

RESUMO

The TGF-beta superfamily comprises a number of functionally diverse growth factors/signalling molecules (1) which elicit their response upon binding to serine-threonine kinase receptors (2). We recently reported the isolation and characterization of two new members of the family, designated cartilage-derived morphogenetic protein (CDMP) 1 and 2 (ref. 3) which are closely related to the sub-family of bone morphogenetic proteins. CDMP-1 is predominantly expressed at sites of skeletal morphogenesis (3), and we now show that a mutation in hCDMP-1 is associated with a recessive human chondrodysplasia (acromesomelic chondrodysplasia, Hunter-Thompson type (4,5)). The disorder, characterized by skeletal abnormalities restricted to the limbs andlimb joints, is phenotypically similar to murine brachypodism (bp) which is due to mutations in growth/differentiation factor-5 (Gdf-5) (6), the mouse homologue of hCDMP-1. Affected individuals are homozygous for a 22-bp (tandem-duplication) frameshift mutation in the mature region of CDMP-1. The resulting phenotype provides direct evidence for the involvement of CDMP-1 in human skeletal development and represents the first human disorder attributable to a mutation in a TGF-beta superfamily member.


Assuntos
Proteínas Morfogenéticas Ósseas , Mutação da Fase de Leitura , Substâncias de Crescimento/genética , Osteocondrodisplasias/genética , Fator de Crescimento Transformador beta/genética , Adolescente , Adulto , Sequência de Aminoácidos , Sequência de Bases , DNA , Feminino , Fator 5 de Diferenciação de Crescimento , Homozigoto , Humanos , Masculino , Dados de Sequência Molecular
10.
Hypertension ; 26(1): 143-9, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7607717

RESUMO

Calcium channel antagonists differ by class in reported frequency of side effects that suggest reflex sympathoadrenal activation. Do such differences result from differential effects on autonomic and baroreflex function? The present study compared acute and chronic effects of two classes of calcium channel antagonists, the dihydropyridine type (felodipine) and the phenylalkylamine type (verapamil), on efferent sympathetic outflow and baroreflex slope in 15 essential hypertensive subjects. Blood pressure, heart rate, hemodynamics, and biochemistries were determined at baseline and after acute (first dose) and chronic (4 weeks) administration of the drugs versus placebo. Acutely, felodipine caused a greater decrease in blood pressure associated with a larger decline in systemic vascular resistance than the corresponding effects produced by verapamil. Chronically, there were similar, significant declines in blood pressure (P = .001) and systemic vascular resistance (P = .001) after each drug. Acutely, increased sympathetic activity after felodipine was suggested by reflex tachycardia (from 69 +/- 3 to 74 +/- 2 beats per minute, P = .014) and elevation of plasma norepinephrine (from 264 +/- 25 to 323 +/- 25 pg/mL, P = .037), whereas after verapamil the corresponding changes were closely similar to those after placebo.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Sistema Nervoso Autônomo/efeitos dos fármacos , Barorreflexo/efeitos dos fármacos , Bloqueadores dos Canais de Cálcio/farmacologia , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Aldosterona/sangue , Análise de Variância , Bloqueadores dos Canais de Cálcio/uso terapêutico , Cardiografia de Impedância , Cromogranina A , Cromograninas/sangue , Epinefrina/sangue , Felodipino/farmacologia , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Renina/sangue , Sistema Nervoso Simpático/efeitos dos fármacos , Fatores de Tempo , Verapamil/farmacologia
11.
Hypertension ; 26(1): 213-20, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7607727

RESUMO

Multiple heritable traits are associated with essential (genetic) hypertension in humans. Because chromogranin A is increased in both human and rodent genetic hypertension, we examined the influence of heredity and blood pressure on chromogranin A in humans. In estimates derived from among- and within-pair variance in monozygotic versus dizygotic twins, plasma chromogranin A displayed significant (F15,18 = 2.93, P = .016) genetic variance (sigma 2 g), and its broad-sense heritability was high (h2B = 0.983). Plasma chromogranin A was increased in essential hypertension (99.9 +/- 6.7 versus 62.8 +/- 4.7 ng/mL, P < .001) but was influenced little by genetic risk for (family history of) hypertension (in normotensive or hypertensive subjects), by race, or by several antihypertensive therapies (angiotensin-converting enzyme inhibitor, diuretic, or beta-adrenergic antagonist). In normotensive subjects at genetic risk for essential hypertension, neither basal nor sympathoadrenal stress-evoked chromogranin A differed from values found in subjects not at risk. In established essential hypertension, plasma chromogranin A responses to adrenal medullary (insulin-evoked hypoglycemia) or sympathetic neuronal (dynamic exercise) activation were exaggerated, whereas responses to sympathoadrenal suppression (ganglionic blockade) were diminished, suggesting increased vesicular stores of chromogranin A and an adrenergic origin of the augmented chromogranin A expression in this disorder. We conclude that plasma chromogranin A displays substantial heritability and is increased in established essential hypertension. Its elevation in established hypertension is associated with evidence of increased vesicular stores of the protein and with adrenergic hyperactivity but is influenced little by customary antihypertensive therapies. However, the chromogranin A elevation is not evident early in the course of genetic hypertension.


Assuntos
Cromograninas/genética , Hipertensão/genética , Medula Suprarrenal/química , Medula Suprarrenal/efeitos dos fármacos , Adulto , Idoso , Análise de Variância , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea , Cromogranina A , Cromograninas/sangue , Doenças em Gêmeos/genética , Feminino , Variação Genética , Humanos , Hipertensão/sangue , Hipertensão/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Neurônios/química , Radioimunoensaio , Fatores de Risco , Sistema Nervoso Simpático/química
13.
Hypertension ; 24(6): 752-7, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7995633

RESUMO

Previous studies have suggested striking racial differences in hypertension-related renal disease. To explore potential mechanisms responsible for these differences, we investigated changes in renal hemodynamics in white and black essential hypertensive patients in response to alterations in dietary sodium. Patients were untreated, age-matched, and blood pressure-matched white (n = 59) and black (n = 22) males with essential hypertension. Studies were conducted on an inpatient metabolic ward and included assessment of blood pressure, urinary sodium excretion, glomerular filtration rate, renal plasma flow, and renal blood flow after 5 days each of high and low salt diets. In response to high dietary salt intake, both white and black patients demonstrated significantly higher mean arterial pressure, renal plasma flow, and renal blood flow, and there were no racial differences in the changes in these parameters. However, whites and blacks differed significantly in glomerular filtration rate, with black hypertensive patients showing an increase in glomerular filtration rate (+17.3 +/- 5.3 mL/min per 1.73 m2, F = 7.586, P = .007) and white hypertensive patients showing no change (-0.2 +/- 3.3 mL/min per 1.73 m2) in response to high dietary sodium. These data demonstrate racial differences in the autoregulation of glomerular filtration rate in response to changes in dietary sodium. These differences suggest that glomerular hyperfiltration in response to a high salt diet may be a mechanism contributing to the racial disparity in hypertension-related renal disease.


Assuntos
População Negra , Hipertensão/etnologia , Hipertensão/fisiopatologia , Circulação Renal/efeitos dos fármacos , Sódio na Dieta/farmacologia , População Branca , Adulto , Idoso , Previsões , Taxa de Filtração Glomerular/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Natriurese
14.
J Hypertens ; 12(11): 1243-7, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7868871

RESUMO

INTRODUCTION: Angiotensin II has both central nervous system and peripheral effects on autonomic function. Ramipril is among the more lipophilic angiotensin converting enzyme (ACE) inhibitors, and hence can penetrate the central nervous system readily. METHODS: We investigated whether rampiril has selective effects on autonomic control of the circulation in human hypertension, compared with the more hydrophilic ACE inhibitor enalapril. Blood pressure, hemodynamics and measurements of autonomic function were obtained in 13 essential hypertensive subjects after 10 days on placebo, and after crossover monotherapy with 10 days on enalapril versus 10 days on ramipril. RESULTS: Both enalapril and ramipril lowered systolic, diastolic and mean arterial blood pressures significantly, with no reflex increase in heart rate. Plasma renin activity increased substantially on each of the ACE inhibitors. There were no significant effects of either agent on plasma catecholamines (norepinephrine or epinephrine) or chromogranin A, biochemical indices of efferent sympatho-adrenal outflow. There were also no significant changes after either agent in baroreflex sensitivity (to high- and low-pressure stimuli), the response to cold stress or sympathetic (alpha-adrenergic) participation in blood pressure maintenance. There was a marginal effect of ACE inhibition on alpha 1-adrenergic pressor sensitivity, but the two compounds did not differ significantly in this respect. CONCLUSION: Autonomic control of circulatory function was maintained well after either lipophilic (ramipril) or hydrophilic (enalapril) ACE inhibitors, and the lipophilic compound ramipril had no additional effects on autonomic function beyond those shown by the hydrophilic agent enalapril.


Assuntos
Sistema Nervoso Autônomo/efeitos dos fármacos , Enalapril/uso terapêutico , Hemodinâmica/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Ramipril/uso terapêutico , Aldosterona/sangue , Sistema Nervoso Autônomo/fisiologia , Pressão Sanguínea/efeitos dos fármacos , Catecolaminas/sangue , Temperatura Baixa , Estudos Cross-Over , Método Duplo-Cego , Feminino , Hemodinâmica/fisiologia , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Renina/sangue
15.
J Hum Hypertens ; 8(7): 515-20, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7932515

RESUMO

Arachidonic acid metabolites such as prostaglandins of the E series have well-documented effects on blood pressure (BP). Recently, a stable analogue of prostaglandin E1 (misoprostol) became available for oral use in humans, being primarily indicated for prevention of peptic disease induced by cyclo-oxygenase inhibitors. We hypothesised that misoprostol would exert antihypertensive actions and therefore performed a randomised, placebo-controlled clinical trial in 15 essential hypertensives to characterise the effects of a 400 micrograms oral dose of misoprostol on BP and its haemodynamic, autonomic and biochemical determinants. There was a modest (from 105.3 +/- 2.7 to 101.9 +/- 2.7 mmHg, P = 0.006) decrease in mean arterial pressure 20 minutes after the dose, accompanied by a decrease in systemic vascular resistance and a compensatory rise in cardiac output and heart rate. Baroreflex gain was unaltered by misoprostol, as were plasma renin activity, catecholamines and chromogranin A. Even this transient antihypertensive effect was abolished by cyclooxygenase inhibitor pretreatment. We conclude that oral misoprostol exerts a modest but transient antihypertensive effect that is unlikely to be of either therapeutic benefit or concern in essential hypertension.


Assuntos
Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Misoprostol/farmacologia , Administração Oral , Adulto , Barorreflexo/efeitos dos fármacos , Interações Medicamentosas , Hemodinâmica/efeitos dos fármacos , Humanos , Hipertensão/fisiopatologia , Ibuprofeno/administração & dosagem , Masculino , Pessoa de Meia-Idade
16.
J Auton Pharmacol ; 14(3): 187-200, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7929473

RESUMO

1. In postganglionic sympathetic neurones and adrenal chromaffin cells, catecholamines are co-stored in vesicles with soluble peptides, including chromogranin A (CgA) and neuropeptide Y (NPY), which are subject to exocytotic co-release with catecholamines. 2. Plasma catecholamine, CgA and NPY responses to stimulators and inhibitors of sympatho-adrenal catecholamine storage and release were measured in humans. Short-term, high-intensity dynamic exercise, prolonged low-intensity dynamic exercise, and assumption of the upright posture, in decreasing order of potency, predominantly stimulated noradrenaline (NA) release from sympathetic nerve endings. Only high-intensity exercise elevated CgA and NPY, which did not peak until 2 min after exercise cessation. Stimulated NA correlated with plasma CgA 2 min after exercise, and with NPY 5 min after exercise. 3. Insulin-evoked hypoglycaemia and caffeine ingestion, in decreasing order of potency, predominantly stimulated adrenaline (AD) release from the adrenal medulla. During insulin hypoglycaemia AD and CgA rose, but NPY was unchanged. Neither NPY nor CgA were altered by caffeine. The rise in CgA after intense adrenal medullary stimulation was greater than its rise after intense sympathetic neuronal stimulation (1.4-versus 1.2-fold, respectively). 4. Infusion of tyramine, which disrupts sympathetic neuronal vesicular NA storage, elevated systolic blood pressure and NA, while NPY and CgA were unchanged. After reserpine, another disruptor of neuronal NA storage, NA transiently rose and then fell; NPY and CgA were unaltered. After the non-exocytotic adrenal medullary secretory stimulus glucagon. AD rose while NA, CgA and NPY did not change. After amantadine, an inhibitor of protein endocytosis, both CgA and fibrinogen rose, while NA and NPY remained unaltered. Neither CgA, NPY, nor catecholamines were altered by the catecholamine uptake and catabolism inhibitors desipramine, cortisol, and pargyline. 5. Human sympathetic nerve contained a far higher ratio of NPY to catecholamines than human adrenal medulla, while adrenal medulla contained far more CgA than sympathetic nerve. 6. It is concluded that peptides are differentially co-stored with catecholamines, with greater abundance of CgA in the adrenal medulla and NPY in sympathetic nerve. Activation of catecholamine release from either the adrenal medulla or sympathetic nerves, therefore, results in quite different changes in plasma concentrations of the catecholamine storage vesicle peptides CgA and NPY. Only profound, intense stimulation of chromaffin cells or sympathetic axons measurably perturbs plasma CgA or NPY concentration; lesser degrees of stimulation perturb plasma catecholamines only. Neither CgA nor NPY are released during non-exocytotic catecholamine secretion.


Assuntos
Medula Suprarrenal/citologia , Cromograninas/metabolismo , Neuropeptídeo Y/metabolismo , Norepinefrina/metabolismo , Medula Suprarrenal/metabolismo , Adulto , Idoso , Amantadina/farmacologia , Análise de Variância , Cafeína/farmacologia , Cromogranina A , Cromograninas/sangue , Endocitose/efeitos dos fármacos , Exercício Físico , Feminino , Humanos , Hipoglicemia/sangue , Hipoglicemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Neuropeptídeo Y/sangue , Norepinefrina/sangue , Postura , Tiramina/farmacologia , Resistência Vascular/efeitos dos fármacos
17.
Clin Sci (Lond) ; 86(2): 149-58, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8143425

RESUMO

1. Dopamine beta-hydroxylase is stored and released with catecholamines by exocytosis from secretory vesicles in noradrenergic neurons and chromaffin cells. Although dopamine beta-hydroxylase enzymic activity is measurable in cerebrospinal fluid, such activity is unstable, and its relationship to central noradrenergic neuronal activity in humans is not clearly established. To explore the significance of cerebrospinal fluid dopamine beta-hydroxylase, we applied a homologous human dopamine beta-hydroxylase radioimmunoassay to cerebrospinal fluid, in order to characterize the properties and stability of cerebrospinal fluid dopamine beta-hydroxylase, as well as its relationship to central noradrenergic neuronal activity and its variation in disease states such as hypertension, renal failure, Parkinsonism and congenital dopamine beta-hydroxylase deficiency. 2. Authentic, physically stable dopamine beta-hydroxylase immunoreactivity was present in normal human cerebrospinal fluid at a concentration of 31.3 +/- 1.4 ng/ml (range: 18.5-52.5 ng/ml), but at a 283 +/- 27-fold lower concentration than that found in plasma. Cerebrospinal fluid and plasma dopamine beta-hydroxylase concentrations were correlated (r = 0.67, P = 0.001). Some degree of local central nervous system control of cerebrospinal fluid dopamine beta-hydroxylase was suggested by incomplete correlation with plasma dopamine beta-hydroxylase (with an especially marked dissociation in renal disease) as well as the lack of a ventricular/lumbar cerebrospinal dopamine beta-hydroxylase concentration gradient. 3. Cerebrospinal fluid dopamine beta-hydroxylase was not changed by the central alpha 2-agonist clonidine at a dose that diminished cerebrospinal fluid noradrenaline, nor did cerebrospinal fluid dopamine beta-hydroxylase correspond between subjects to cerebrospinal fluid concentrations of noradrenaline or methoxyhydroxyphenylglycol; thus, cerebrospinal fluid dopamine beta-hydroxylase concentration was not closely linked either pharmacologically or biochemically to central noradrenergic neuronal activity. 4. Cerebrospinal fluid dopamine beta-hydroxylase was not changed in essential hypertension. In Parkinson's disease, cerebrospinal fluid dopamine beta-hydroxylase was markedly diminished (16.3 +/- 2.9 versus 31.3 +/- 1.4 ng/ml, P < 0.001) and rose by 58 +/- 21% (P = 0.02) after adrenal-to-caudate chromaffin cell autografts. In congenital dopamine beta-hydroxylase deficiency, lack of detectable dopamine beta-hydroxylase immunoreactivity in cerebrospinal fluid or plasma suggests absent enzyme (rather than a catalytically defective enzyme) as the origin of the disorder. 5. We conclude that cerebrospinal fluid dopamine beta-hydroxylase immunoreactivity, while not closely linked to central noradrenergic neuronal activity, is at least in part derived from the central nervous system, and that its measurement may be useful in both the diagnosis and treatment of neurological disease.


Assuntos
Dopamina beta-Hidroxilase/líquido cefalorraquidiano , Dopamina beta-Hidroxilase/deficiência , Norepinefrina/líquido cefalorraquidiano , Doença de Parkinson/enzimologia , Adulto , Dopamina beta-Hidroxilase/sangue , Feminino , Humanos , Hipertensão/enzimologia , Immunoblotting , Nefropatias/enzimologia , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/enzimologia , Norepinefrina/sangue , Radioimunoensaio
18.
Neuroscience ; 56(4): 999-1007, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7904334

RESUMO

Although measurement of chromogranin A in the bloodstream is of value in sympathoadrenal investigations, little is systematically known about chromogranin A in cerebrospinal fluid, despite substantial knowledge about its occurrence and distribution in brain. We therefore applied a homologous human chromogranin A radioimmunoassay to cerebrospinal fluid, in order to evaluate the properties and stability of cerebrospinal fluid chomogranin A, as well as its relationship to central noradrenergic neuronal activity, to peripheral (plasma) chromogranin A, and to disease states such as hypertension, renal failure and Parkinsonism. Authentic, physically stable chromogranin A immunoreactivity was found in cerebrospinal fluid (at 37-146 ng/ml; mean, 87.0 +/- 6.0 ng/ml in healthy subjects), and several lines of evidence (including 3.39 +/- 0.27-fold higher chromogranin A in cerebrospinal fluid than in plasma) indicated that it originated from a local central nervous system source, rather than the periphery. Cerebrospinal fluid chromogranin A values were not influenced by administration of effective antihypertensive doses of clonidine or propranolol, and were not related to the cerebrospinal fluid concentrations of norepinephrine, methoxyhydroxyphenylglycol, or dopamine-beta-hydroxylase; thus, cerebrospinal fluid chromogranin A was not closely linked to biochemical or pharmacologic indices of central noradrenergic neuronal activity. Cerebrospinal fluid chromogranin A was not changed (P > 0.1) in essential hypertension (84.2 +/- 14.0 ng/ml) or renal failure (72.2 +/- 13.4 ng/ml), despite a marked (7.1-fold; P < 0.001) increase in plasma chromogranin A in renal failure, and a modest (1.5-fold; P = 0.004) increase in plasma chromogranin A in essential hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Cromograninas/líquido cefalorraquidiano , Antagonistas Adrenérgicos beta/farmacologia , Adulto , Idoso , Sequência de Aminoácidos , Encefalopatias/líquido cefalorraquidiano , Encefalopatias/parasitologia , Cromogranina A , Cromograninas/sangue , Clonidina/farmacologia , Cisticercose/líquido cefalorraquidiano , Feminino , Humanos , Hipertensão/líquido cefalorraquidiano , Falência Renal Crônica/líquido cefalorraquidiano , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Doença de Parkinson/líquido cefalorraquidiano , Radioimunoensaio
19.
Am J Med Genet ; 43(4): 701-3, 1992 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-1621761

RESUMO

We report on a patient with interstitial deletion of 10q and compare her to 8 previously described patients, 2 of whom have chromosomal breakpoints similar to our patient. Minor anomalies including broad forehead, hypertelorism, strabismus, prominent philtrum, and "dysplastic" pinnae are present in our patient. Psychomotor retardation and hypotonia are universal findings in 10q interstitial deletion. Growth retardation, not present in our patient, is seen in some. These clinical findings are sufficiently distinct to suggest early chromosome studies.


Assuntos
Aberrações Cromossômicas/genética , Deleção Cromossômica , Cromossomos Humanos Par 10 , Deficiência Intelectual/genética , Aberrações Cromossômicas/fisiopatologia , Bandeamento Cromossômico , Transtornos Cromossômicos , Feminino , Crescimento , Humanos , Lactente , Deficiência Intelectual/fisiopatologia , Cariotipagem
20.
Artigo em Inglês | MEDLINE | ID: mdl-1303128

RESUMO

Appliers of pesticides (n = 18) who are exposed to the fumigant phosphine or who have a mixed exposure to other pesticides and phosphine demonstrate a significant increase in chromosome rearrangements in G-banded chromosomes from peripheral blood compared to control subjects (n = 26). Appliers who had discontinued using phosphine for at least 8 months prior to specimen collection (n = 5) do not demonstrate significant increases in chromosome rearrangements compared to controls. Breakpoint analysis of 6,138 metaphases from all subjects demonstrates 196 breaks per 3605 metaphases in exposed subjects and 102 breaks per 2,533 metaphases in control subjects. Bands with significantly more breaks than expected based on band length in all study subjects were 1q32, 3p14, 7p15, and 14q11. Three of these four bands had significantly more breaks than expected in the exposed group, and all four bands had a significant excess of breaks in the control group. There are four bands with a significant excess of breaks in the exposed group and no breaks in the control group; each of these occurs in a known protooncogene region. These are 1p13 (NRAS), 2p23 (NMYC), 14q32 (ELK2), and 21q12 (ETS-2). Most breaks at bands 1p13, 14q32, and 21q22 are associated with chromosome rearrangements and occurred in appliers who have a mixed exposure to phosphine and other pesticides. Cytogenetic abnormalities, i.e., rearrangements and/or deletions involving bands 1p13, 2p23, and 14q32, are associated with non-Hodgkin's lymphoma. We speculate that these findings could relate to the risk of evolution of a neoplastic clone in these workers. Epidemiological studies of similarly exposed workers indicate an excess of non-Hodgkin's lymphoma.


Assuntos
Rearranjo Gênico/efeitos dos fármacos , Inseticidas/efeitos adversos , Linfoma não Hodgkin/induzido quimicamente , Doenças Profissionais/induzido quimicamente , Exposição Ocupacional , Fosfinas/efeitos adversos , Cromátides/efeitos dos fármacos , Aberrações Cromossômicas , Cromossomos/efeitos dos fármacos , Cromossomos Humanos Par 1/efeitos dos fármacos , Cromossomos Humanos Par 14/efeitos dos fármacos , Seguimentos , Humanos , Cariotipagem , Linfoma não Hodgkin/genética , Masculino , Metáfase , Doenças Profissionais/genética , Praguicidas/efeitos adversos , Fatores de Risco , Fatores de Tempo , Translocação Genética/efeitos dos fármacos
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