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1.
Clin Genet ; 91(3): 441-447, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27102574

RESUMO

NDUFB11, a component of mitochondrial complex I, is a relatively small integral membrane protein, belonging to the "supernumerary" group of subunits, but proved to be absolutely essential for the assembly of an active complex I. Mutations in the X-linked nuclear-encoded NDUFB11 gene have recently been discovered in association with two distinct phenotypes, i.e. microphthalmia with linear skin defects and histiocytoid cardiomyopathy. We report on a male with complex I deficiency, caused by a de novo mutation in NDUFB11 and displaying early-onset sideroblastic anemia as the unique feature. This is the third report that describes a mutation in NDUFB11, but all are associated with a different phenotype. Our results further expand the molecular spectrum and associated clinical phenotype of NDUFB11 defects.


Assuntos
Acidose Láctica/genética , Anemia Sideroblástica/genética , Complexo I de Transporte de Elétrons/genética , Microftalmia/genética , Acidose Láctica/complicações , Acidose Láctica/fisiopatologia , Anemia Sideroblástica/complicações , Anemia Sideroblástica/fisiopatologia , Criança , DNA Mitocondrial/genética , Complexo I de Transporte de Elétrons/deficiência , Predisposição Genética para Doença , Humanos , Masculino , Microftalmia/fisiopatologia , Mutação , Linhagem , Fenótipo , Tirosina-tRNA Ligase
2.
Scand J Med Sci Sports ; 25(3): 382-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24766540

RESUMO

Adult and adolescent elite black athletes display - as compared with their white counterparts - excessively increased left ventricle (LV) wall thickness (LVWT), mass (LVM), and relative wall thickness (RWT). To investigate such ethnicity-related differences in non-professional adolescent athletes, 138 male, amateur football players [age 14.0 ± 1.7 years, 42 West-African blacks (BA) and 96 Italian whites (WA)] underwent an echocardiographic study of LV diameters, LVWT, maximal wall thickness (MWT), LVM, and RWT as remodeling index. BA vs WA exhibited greater thickness of septum and posterior wall, higher MWT (10.3 ± 1.7 vs 8.8 ± 1.1 mm), and higher LVM (117 ± 27 vs 101 ± 20 g/m(2)) and RWT (0.44 ± 0.07 vs 0.35 ± 0.04). Age, systolic blood pressure, body mass index, and ethnicity predicted MWT and LVM, whereas ethnicity was the sole strong predictor of RWT. The greater MWT, LVWT, and LVM of 14-year-old, amateur-level BA vs WA indicates that ethnicity substantially affects LV structure in adolescent, non-professional athletes. In contrast with MWT and LVM, elevated RWT was predicted by black ethnicity only. We suggest that concentric-type LV remodeling is a peculiar LV phenotype in adolescent African athletes.


Assuntos
Adaptação Fisiológica , Atletas , População Negra , Ventrículos do Coração/diagnóstico por imagem , Futebol , Remodelação Ventricular , População Branca , Adolescente , África Ocidental/etnologia , Pressão Sanguínea , Índice de Massa Corporal , Criança , Ecocardiografia , Humanos , Itália , Masculino , Tamanho do Órgão
3.
Sci Total Environ ; : 176528, 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39332742

RESUMO

Anthropogenic litter, such as plastic, is investigated by the global scientific community from various fields employing diverse techniques. The goal is to assess and finally mitigate the pollutants' impacts on the natural environment. Plastic litter can accumulate in different matrices of aquatic and terrestrial ecosystems, impacting both biota and ecosystem functioning. Detection and quantification of macroplastics, and other litter, can be realized by jointly using visual census and remote sensing techniques. The primary objective of this research was to identify the most effective approach for monitoring macroplastic litter in riverine and marine environments through a comprehensive survey based on the experiences of the scientific community. Researchers involved in plastic pollution evaluated four litter occurrence and flux investigation methods (visual census, drone-based surveys, satellite imagery, and GPS/GNSS trackers) through a questionnaire. Traditional visual census and drone deployment were deemed as the most popular approaches among the 46 surveyed researchers, while satellite imagery and GPS/GNSS trackers received lower scores due to limited field validation and short performance ranges, respectively. On a scale from 0 to 5, visual census and drone-based surveys obtained 3.5 and 2.0, respectively, whereas satellite imagery and alternative solutions received scores lower than 1.2. Visual and drone censuses were used in high, medium and low-income countries, while satellite census and GPS/GNSS trackers were mostly used in high-income countries. This work provides an overview of the advantages and drawbacks of litter investigation techniques, contributing i) to the global harmonization of macroplastic litter monitoring and ii) providing a starting point for researchers and water managers approaching this topic. This work supports the selection and design of reliable and cost-effective monitoring approaches to mitigate the ambiguity in macroplastic data collection, contributing to the global harmonization of macroplastic litter monitoring protocols.

4.
Ann Ig ; 22(2): 131-46, 2010.
Artigo em Italiano | MEDLINE | ID: mdl-20476653

RESUMO

On 6th April 2009, at 3.32 AM, there was in L'Aquila and in some neighbouring villages, after an earthquake swarm last some months, an earthquake of M(L) = 5.8 (Richter magnitude scale) on depth of 8.8 km. The event was sensed in a very broad area, till in Rome and Ancon. The operative committee of the Civil Protection Department immediately gathered and a first operating group was despatched in the epicentre; the voluntary association of civil protection were in a pre-alarm situation and then were activated. This work want describe all the activities from 6th April 2009 till 31th August 2009, giving too a synthesis of the normative lines in case of catastrophic events typology C, otherwise all that events impossible to manage without national intervention.


Assuntos
Terremotos , Saúde Pública , Humanos , Itália , Trabalho de Resgate
5.
Science ; 250: 1700-2, 1990 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-11538083

RESUMO

The iridium anomaly at the Cretaceous-Tertiary (KT) boundary was discovered in the pelagic limestone sequence at Gubbio on the basis of 12 samples analyzed by neutron activation analysis (NAA) and was interpreted as indicating impact of a large extraterrestrial object at exactly the time of the KT mass extinction. Continuing controversy over the shape of the Ir profile at the Gubbio KT boundary and its interpretation called for a more detailed follow-up study. Analysis of a 57-meter-thick, 10-million-year-old part of the Gubbio sequence using improved NAA techniques revealed that there is only one Ir anomaly at the KT boundary, but this anomaly shows an intricate fine structure, the origin of which cannot yet be entirely explained. The KT Ir anomaly peaks in a 1-centimeter-thick clay layer, where average Ir concentration is 3000 parts per trillion (ppt); this peak is flanked by tails with Ir concentrations of 20 to 80 ppt that rise above a background of 12 to 13 ppt. The fine structure of the tails is probably due in part to lateral reworking, diffusion, burrowing, and perhaps Milankovitch cyclicity.


Assuntos
Evolução Biológica , Carbonato de Cálcio/química , Geologia , Irídio/análise , Meio Ambiente Extraterreno , Fenômenos Geológicos , Itália , Paleontologia
6.
Science ; 291(5510): 1952-5, 2001 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-11239153

RESUMO

Analyses of marine carbonates through the interval 63.9 to 65.4 million years ago indicate a near-constant flux of extraterrestrial helium-3, a tracer of the accretion rate of interplanetary dust to Earth. This observation indicates that the bolide associated with the Cretaceous-Tertiary (K-T) extinction event was not accompanied by enhanced solar system dustiness and so could not have been a member of a comet shower. The use of helium-3 as a constant-flux proxy of sedimentation rate implies deposition of the K-T boundary clay in (10 +/- 2) x 10(3) years, precluding the possibility of a long hiatus at the boundary and requiring extremely rapid faunal turnover.

7.
Science ; 264(5158): 546-50, 1994 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-17732737

RESUMO

The (87)Sr/(86)Sr ratio in fish teeth separated from mid-Cretaceous marl and black shale from the northeastern Apennines and Venetian Alps (Italy) define three periods of low (87)Sr/(86)Sr ratio at 121 to 124 million years ago (Ma), 110 to 115 Ma, and 89 to 91 Ma. The (87)Sr/(86)Sr excursions correspond to oceanic anoxic events represented by the Livello Selli, Livello 113, Livello Urbino, and Livello Bonarelli black shale marker beds and probably reflect an increase in the low-(87)Sr/(86)Sr hydrothermal strontium flux associated with the emplacement of the Ontong-Java and Kerguelen plateaus (120 to 110 Ma) and the Caribbean Plateau (89 to 91 Ma). The modeled flux is consistent with the volumes and eruption rates of the oceanic plateaus but is far smaller than expected from the proposed Cretaceous crustal production rates of 50 to 100 percent greater than modern.

8.
Science ; 280(5367): 1250-3, 1998 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-9596575

RESUMO

Analyses of pelagic limestones indicate that the flux of extraterrestrial helium-3 to Earth was increased for a 2.5-million year (My) period in the late Eocene. The enhancement began approximately 1 My before and ended approximately 1.5 My after the major impact events that produced the large Popigai and Chesapeake Bay craters approximately 36 million years ago. The correlation between increased concentrations of helium-3, a tracer of fine-grained interplanetary dust, and large impacts indicates that the abundance of Earth-crossing objects and dustiness in the inner solar system were simultaneously but only briefly enhanced. These observations provide evidence for a comet shower triggered by an impulsive perturbation of the Oort cloud.


Assuntos
Planeta Terra , Sedimentos Geológicos/química , Meteoroides , Poeira Cósmica , Evolução Planetária , Hélio , Isótopos
9.
Science ; 257(5072): 954-8, 1992 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-17789640

RESUMO

(40)Ar/(39)Ar dating of drill core samples of a glassy melt rock recovered from beneath a massive impact breccia contained within the 180-kilometer subsurface Chicxulub crater in Yucatán, Mexico, has yielded well-behaved incremental heating spectra with a mean plateau age of 64.98 +/- 0.05 million years ago (Ma). The glassy melt rock of andesitic composition was obtained from core 9 (1390 to 1393 meters) in the Chicxulub 1 well. The age of the melt rock is virtually indistinguishable from (40)Ar/(39)Ar ages obtained on tektite glass from Beloc, Haiti, and Arroyo el Mimbral, northeastern Mexico, of 65.01 +/- 0.08 Ma (mean plateau age for Beloc) and 65.07 +/- 0.10 Ma (mean total fusion age for both sites). The (40)Ar/(39)Ar ages, in conjunction with geochemical and petrological similarities, strengthen the recent suggestion that the Chicxulub structure is the source for the Haitian and Mexican tektites and is a viable candidate for the Cretaceous-Tertiary boundary impact site.

10.
RSC Adv ; 9(63): 36699-36706, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-35539052

RESUMO

Cysteine proteases play a key role in tumorigenesis causing protein degradation and promoting invasive tumour growth. Cathepsin L is overexpressed in cancer cells and could provide a specific target for delivery of anticancer agents. We encapsulated novel dipeptidyl nitrile based cysteine protease inhibitors (Neq0551, Neq0554 and Neq0568) into biocompatible apoferritin (AFt) protein nanocages to achieve specific delivery to tumours and pH-induced drug release. AFt-encapsulated Neq0554 demonstrated ∼3-fold enhanced in vitro activity (GI50 = 79 µM) compared to naked agent against MiaPaCa-2 pancreatic carcinoma cells. Selectivity for cancer cells was confirmed by comparing their activity to non-tumourigenic human fibroblasts (GI50 > 200 µM). Transferrin receptor (TfR-1) expression, detected only in lysates prepared from carcinoma cells, may contribute to the cancer-selectivity. The G1 cell cycle arrest caused by AFt-Neq0554 resulting in cytostasis was corroborated by clonogenic assays. Superior and more persistent inhibition of cathepsin L up to 80% was achieved with AFt-encapsulated agent in HCT-116 cells following 6 h exposure to 50 µM agent. The selective anticancer activity of AFt-encapsulated cysteine protease inhibitor Neq0554 reported here warrants further preclinical in vivo evaluation.

11.
Rev Sci Instrum ; 87(2): 02A740, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26931958

RESUMO

Different electron guns based on cold- or hot-cathode technologies have been developed since 2009 at INFN for operating within ECR plasma chambers as sources of auxiliary electrons, with the aim of boosting the source performances by means of a higher plasma lifetime and density. Their application to microwave discharge ion sources, where plasma is not confined, has required an improvement of the gun design, in order to "screen" the cathode from the plasma particles. Experimental tests carried out on a plasma reactor show a boost of the plasma density, ranging from 10% to 90% when the electron guns are used, as explained by plasma diffusion models.

12.
Acta Biomed ; 87(3): 314-317, 2016 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-28112700

RESUMO

Solitary fibrous pleura tumor is a rare primary intrathoracic tumor of the pleura. It usually has an indolent clinical course, but sometimes it can have an aggressive behaviour. In 1930 Doege and Potter independently described this neoplasm, presenting with symptoms of hypoglycemia, hence the eponim of Doege-Potter's Syndrome. In this report, we illustrate a case of Doege Potter's Syndrome, treated with complete surgical resection.


Assuntos
Hipoglicemia/etiologia , Tumor Fibroso Solitário Pleural/complicações , Idoso , Humanos , Masculino , Índice de Gravidade de Doença , Tumor Fibroso Solitário Pleural/patologia , Tumor Fibroso Solitário Pleural/cirurgia , Síndrome
13.
Diabetes ; 34(8): 812-5, 1985 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3894123

RESUMO

Insulin-dependent diabetes mellitus (IDDM) induces plasma amino acid (AA) abnormalities, including low alanine and high branched-chain (BCAA). While insulin treatment restores plasma AA pattern, proline, methionine, valine, isoleucine, and total BCAA remain elevated in skeletal muscle intracellular water. This suggests that the restoration of plasma AA concentrations is not a satisfactory index of recovered AA metabolism in IDDM.


Assuntos
Aminoácidos/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Insulina/uso terapêutico , Músculos/metabolismo , Adulto , Aminoácidos/sangue , Aminoácidos de Cadeia Ramificada/metabolismo , Água Corporal/metabolismo , Cloretos/metabolismo , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Espaço Extracelular/metabolismo , Feminino , Humanos , Líquido Intracelular/metabolismo , Masculino , Pessoa de Meia-Idade
14.
Hypertension ; 35(4): 869-74, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10775553

RESUMO

To investigate whether sodium sensitivity of blood pressure participates in the relationship of arterial hypertension to chronic alcohol consumption, 30 alcoholics detoxified from 6 to 12 months and 30 teetotaler controls underwent a dietary sodium manipulation study. They received a daily 55 mmol sodium diet for 7 days, followed by a 260 mmol sodium diet for 7 days. Changes in 24-hour urinary sodium excretion between the end of each period were similar in alcoholics and controls (202+/-16 SEM mmol and 227+/-11, respectively). Plasma renin activity in alcoholics was lower than in controls at both low (2.4+/-0.4 ng angiotensin I/mLxh(-1) versus 3. 7+/-0.2, P<0.003) and high sodium intake (0.47+/-0.10 versus 0. 82+/-0.10, P<0.05), with smaller variations in alcoholics (-1.9+/-0. 3 versus -2.9+/-0.2, P<0.009). In alcoholics, alteration in sodium intake was followed by greater changes in both systolic and mean blood pressure (ambulatory blood pressure monitoring), which rose by 10.6+/-2.2 mm Hg and 7.3+/-1.5 versus 4.7+/-1.4 and 3.9+/-1.0 in controls, respectively (P<0.03 for systolic and P<0.05 for mean blood pressure). The ratio of changes in mean blood pressure to those in 24-hour urinary sodium excretion was higher in alcoholics (0.044+/- 0.011 mm Hgxmmol(-1) versus 0.018+/-0.0041, P<0.005). Our data show that in detoxified alcoholics, there is an abnormal response of both blood pressure and plasma renin activity to variations in salt intake similar to that in sodium-sensitive arterial hypertension. The precise relationship between the sodium sensitivity of blood pressure in detoxified alcoholics and the long-term influence of alcohol on blood pressure remains to be elucidated.


Assuntos
Alcoolismo/fisiopatologia , Pressão Sanguínea/efeitos dos fármacos , Sódio na Dieta/administração & dosagem , Sódio/metabolismo , Alcoolismo/metabolismo , Alcoolismo/terapia , Doença Crônica , Feminino , Humanos , Inativação Metabólica , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
15.
Hypertension ; 30(3 Pt 2): 557-62, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9322981

RESUMO

In seven healthy, young subjects on a 240 mmol sodium diet, mean arterial pressure (MAP), renal hemodynamics, and renal handling of Na and exogenous Li were measured at baseline and during short-term nitric oxide (NO) blockade with a 90-minute infusion of 3.0 microg x kg(-1) x min(-1) of N(G)-L-arginine methyl ester (L-NAME). The infusion was performed twice: after a 3-day pretreatment with either placebo or 50 mg losartan to block Ang II receptors. With placebo, L-NAME produced no change in MAP from 0 to 45 minutes (period 1) and only a 5% increase at 45 to 90 minutes (period 2) of infusion. Effective renal plasma flow (ERPF, PAH clearance) and glomerular filtration rate (GFR, inulin clearance) declined by 11.7% and 8.0%, respectively in period 1 and by 14.6% and 11.6%, respectively, in period 2. Calculated renal vascular resistance (RVR) increased by 13.0% to 20.6%. Fractional excretion of Na (FE(Na)) and Li (FE(Li)) fell by 30.0% and 21.0%, respectively, in period 1 and by 44.2% and 31.1% in period 2. All these variations were significant versus baseline. With losartan, the rise in MAP at 45 to 90 minutes was completely abolished, whereas all changes in ERPF, GFR, RVR, FE(Na), and FE(Li) in response to L-NAME were the same as those observed with placebo. The present data show that NO blockade with low-dose systemic infusion of L-NAME produces renal vasoconstriction, reduced GFR, and increased tubular Na reabsorption independent of changes in MAP. Reduced FE(Li) indicates an effect of NO on the proximal tubule. Since these changes are not prevented by losartan, we conclude that in Na-repleted humans, renal vasoconstriction and Na-retaining effects of inhibition of basal NO production are not due to the unopposed action of endogenous Ang II.


Assuntos
Angiotensina II/antagonistas & inibidores , Compostos de Bifenilo/farmacologia , Inibidores Enzimáticos/farmacologia , Imidazóis/farmacologia , Rim/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Sódio na Dieta/administração & dosagem , Tetrazóis/farmacologia , Adulto , Feminino , Humanos , Rim/fisiologia , Losartan , Masculino , Óxido Nítrico/fisiologia
16.
Hypertension ; 31(1 Pt 2): 277-82, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9453316

RESUMO

In eight young healthy subjects on a 240 mM Na diet mean arterial pressure (MAP), renal hemodynamics and renal handling of Na and exogenous Li were measured at baseline and during acute nitric oxide (NO) inhibition with 90-minute infusion of 3.0 microg/kg x min(-1) of N(G)-L-arginine methyl ester (L-NAME). The same experiment was repeated with infusion of 50 microg/kg x min(-1) of DA2 receptor blocker L-Sulpiride (L-SULP) alone and, finally, with simultaneous infusion of both L-NAME and L-SULP. L-SULP alone did not elicit any effect. L-NAME alone produced no changes in MAP from 0 to 45 minutes (P1) and a 6.6% increase at 45 to 90 minutes (P2) of infusion. Effective renal plasma flow (ERPF, PAH clearance) and glomerular filtration rate (GFR, inulin clearance) declined by 10.2% and 7.6%, respectively, in P1 and by 15.3% and 11.5% in P2. Filtration Fraction (FF) rose by 4.2% in P2. Calculated renal vascular resistance (RVR) increased by 13.0% to 25.6%. Fractional excretion of Na (FENa) and Li (FELi) fell by 20.0% and by 16.0%, respectively, in P1 and by 40.0% and 25.1% in P2. All these variations, except for MAP and GFR, were significantly greater during coinfusion of L-NAME and L-SULP. ERPF declined by 17.8% to 33.7%, FENa by 26.7% to 53.3%, FELi by 13.8% to 34.8%, while RVR rose by 22.5% to 59.1% and FF by 10.1% to 29.3%. The present data confirm that NO blockade with low-dose systemic infusion of L-NAME produces renal vasoconstriction, reduced GFR with slight increase in FF, and enhanced tubular Li, and Na reabsorption. Since increase in RVR and FF and decrease in FENa and FELi are markedly potentiated by the simultaneous infusion of DA2 blocker L-SULP, which exerts no effects by itself, we suggest that DA interactions between DA system at the level of DA2 receptors and basal NO production play a physiological role in the regulation of renal function in humans.


Assuntos
Pressão Sanguínea/fisiologia , Hemodinâmica/fisiologia , Rim/fisiologia , NG-Nitroarginina Metil Éster/farmacologia , Receptores de Dopamina D1/antagonistas & inibidores , Sulpirida/farmacologia , Adulto , Pressão Sanguínea/efeitos dos fármacos , Antagonistas de Dopamina/administração & dosagem , Antagonistas de Dopamina/farmacologia , Sinergismo Farmacológico , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Humanos , Infusões Intravenosas , Rim/efeitos dos fármacos , Lítio/metabolismo , Masculino , NG-Nitroarginina Metil Éster/administração & dosagem , Nitratos/urina , Óxido Nítrico Sintase/antagonistas & inibidores , Nitritos/urina , Circulação Renal/efeitos dos fármacos , Sódio/metabolismo , Sódio na Dieta , Sulpirida/administração & dosagem , Resistência Vascular/efeitos dos fármacos
17.
Hypertension ; 12(5): 498-505, 1988 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2847983

RESUMO

In nine young normotensive subjects with no family history of hypertension and nine age-matched normotensive subjects with one parent with essential hypertension, effective renal plasma flow (p-aminohippuric acid clearance), glomerular filtration rate (inulin clearance), and excretion of sodium and exogenously administered lithium were measured for 90 minutes before and after administration of a single 20-mg oral dose of the calcium entry blocker nifedipine. Segmental tubular handling of fluid and sodium was estimated using lithium clearance as a marker of proximal tubular reabsorption. Nifedipine did not cause any change in subjects with no family history of hypertension, but in those with one hypertensive parent there was a marked increase in effective renal plasma flow (from 644 +/- 39 to 847 +/- 42 [SEM] ml/min x 1.73 m2; p less than 0.001) and a decrease in filtration fraction (from 17.6 +/- 1.0 to 12.6 +/- 0.4%; p less than 0.001), while the glomerular filtration rate was unchanged, thus suggesting a prevailing efferent vasodilation. Sodium excretion rate (p less than 0.02) and fractional sodium excretion (p less than 0.025) increased slightly but significantly in subjects with one hypertensive parent, but not in normotensive subjects with no family history of hypertension. Lithium clearance also rose (from 29.0 +/- 2.0 to 32.8 +/- 1.9 ml/min, p less than 0.001), and the derived value of fractional proximal reabsorption diminished (from 75.8 +/- 1.0 to 71.3 +/- 1.2%, p less than 0.001). Estimated distal delivery of sodium and absolute distal sodium reabsorption both increased significantly (p less than 0.005), while fractional distal sodium reabsorption was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Canais de Cálcio/efeitos dos fármacos , Hipertensão/fisiopatologia , Rim/fisiopatologia , Adulto , Pressão Sanguínea/efeitos dos fármacos , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Hipertensão/genética , Túbulos Renais Proximais/efeitos dos fármacos , Lítio/farmacocinética , Masculino , Nifedipino/farmacologia , Circulação Renal/efeitos dos fármacos , Sódio/sangue
18.
Hypertension ; 35(1 Pt 2): 518-23, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10642352

RESUMO

Eight Na-repleted volunteers underwent 3 separate 90-minute infusions of either N(G)-nitro-L-arginine methyl ester (L-NAME) 3.0 mg. kg(-1). min(-1) or endothelin-A receptor (ET-A) blocker BQ-123 (BQ) 0.125 nmol. kg(-1). min(-1) or both. Mean arterial pressure (MAP), glomerular filtration rate (GFR), renal blood flow (RBF), renal vascular resistances (RVR), and sodium excretion rate (UNaV) were measured at baseline (b) and from 0 to 45 minutes (period 1) and 45 to 90 minutes (period 2) of infusion. BQ alone had no effect. GFR declined by 4.9% (P<0.001 versus b) in period 1, to 9.9% (P<0. 001) in period 2 with L-NAME, and by 3.3% (P<0.01) to 6.6% (P<0.001) with L-NAME plus BQ (P=NS between L-NAME and L-NAME plus BQ). UNaV fell equally with L-NAME or L-NAME plus BQ. MAP rose significantly in period 2 with L-NAME (6.9%; P<0.001) but not with coinfused BQ (2. 1%; P=NA versus b, P=0.005 versus L-NAME alone). RBF declined by 12. 2% (P<0.001) to 18.3% (P<0.001) with L-NAME and by 4.6% (P<0.005) to 8.2% (P<0.001) with L-NAME plus BQ. These changes were smaller with L-NAME plus BQ (P<0.05 in period 1 and P<0.02 in period 2). Blunted changes were also seen for RVR (P<0.005 in period 1 and P<0.001 in period 2 between L-NAME alone and L-NAME plus BQ). These findings show that systemic and renal vasoconstriction due to L-NAME are attenuated by BQ, which suggests that an interaction between endogenous nitric oxide production and ET-A activity participates in the maintenance of baseline systemic and renal vascular tone in humans.


Assuntos
Anti-Hipertensivos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Antagonistas dos Receptores de Endotelina , Inibidores Enzimáticos/administração & dosagem , NG-Nitroarginina Metil Éster/administração & dosagem , Peptídeos Cíclicos/administração & dosagem , Adulto , Feminino , Humanos , Rim/irrigação sanguínea , Rim/efeitos dos fármacos , Rim/fisiologia , Lítio/urina , Masculino , Óxido Nítrico/metabolismo , Nitritos/urina , Receptor de Endotelina A , Sódio/urina , Vasoconstrição/efeitos dos fármacos
19.
Hypertension ; 6(6 Pt 1): 826-31, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6097541

RESUMO

Ouabain-resistant Na and Li effluxes in erythrocytes from 18 normal subjects and 19 hypertensive subjects were studied in fresh cells that contained about 9 mmol Li and 2.5 or 6.5 mmol Na per liter of erythrocytes after intact cells had been incubated for 5 hours in 110 mM Li, 40 mM Na medium, with or without ouabain 10(-4) M. Outward Na cotransport was estimated at both internal Na concentrations as the furosemide-sensitive unidirectional 22Na efflux from erythrocytes into a Na free-medium containing 75 mM MgCl2. The changes in furosemide-sensitive outward Na transport between the two levels of internal Na were considered as a measure of the response of Na cotransport to the changes in internal Na within its physiological range. At both levels of internal Na, outward Na cotransport was reduced in the majority but not in all of the patients with essential hypertension (p less than 0.05 at 2.5 mmol; p less than 0.001 at 6.5 mmol). The ratio of the changes in Na cotransport to those in internal Na was lower in the hypertensive patients than in the control subjects (17.2 mumol/liter red blood cells/hr/1 mmol in internal Na increase vs 42.2, p less than 0.001). The Li-Na countertransport was increased in a few patients with essential hypertension, with no relationship to cotransport. We conclude that, in essential hypertension, the outward Na + K cotransport is impaired in fresh erythrocytes not treated with PCMBS (2,5 p-chloromercuribenzene sulfonate) or nystatin, even when internal Na is around its physiological range.


Assuntos
Eritrócitos/metabolismo , Hipertensão/sangue , Potássio/metabolismo , Sódio/metabolismo , 4-Cloromercuriobenzenossulfonato/farmacologia , Adolescente , Adulto , Transporte Biológico/efeitos dos fármacos , Pressão Sanguínea , Eritrócitos/efeitos dos fármacos , Feminino , Furosemida/farmacologia , Humanos , Hipertensão/metabolismo , Lítio/metabolismo , Masculino , Pessoa de Meia-Idade , Nistatina/farmacologia , Ouabaína/farmacologia , Potássio/sangue , Sódio/sangue
20.
J Med Chem ; 33(7): 2000-6, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2362281

RESUMO

In order to facilitate identification of possible metabolites arising from in vitro action of catechol-O-methyltransferase upon 7,8-dihydroxy- and 8,9-dihydroxy-4-n-propyl-1,2,3,4,4a,5,6,10b-octahydrobenzo[f]quinolines (11, 12), all four possible monomethyl ether derivatives have been synthesized. Incubation of 11 and 12 with the enzyme revealed that the 8,9-dihydroxy positional isomer 12 (which contains the dopamine moiety held in the beta conformation) but not the 7,8-dihydroxy isomer 11 (which holds the dopamine moiety in the alpha conformation) was a substrate for the enzyme. The sole detectable product of 12 was 8-hydroxy-9-methoxy derivative 15 in which the "meta" hydroxy group of the dopamine moiety is etherified.


Assuntos
Catecol O-Metiltransferase/metabolismo , Hidroxiquinolinas/síntese química , Animais , Pressão Sanguínea/efeitos dos fármacos , Gatos , Feminino , Sistema de Condução Cardíaco/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Hidroxiquinolinas/metabolismo , Hidroxiquinolinas/farmacologia , Indicadores e Reagentes , Masculino , Estrutura Molecular , Análise Espectral , Relação Estrutura-Atividade
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