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1.
Ann Rheum Dis ; 75(2): 332-40, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26293163

RESUMEN

OBJECTIVES: To evaluate the efficacy and safety of tabalumab, a human IgG4 monoclonal antibody that neutralises membrane and soluble B-cell activating factor (BAFF). METHODS: This randomised, placebo-controlled study enrolled 1124 patients with moderate-to-severe systemic lupus erythematosus (SLE) (Safety of Estrogens in Lupus Erythematosus National Assessment- SLE Disease Activity Index ≥6 at baseline). Patients received standard of care plus subcutaneous study drug, starting with a loading dose (240 mg) at week 0 and followed by 120 mg every 2 weeks (120 Q2W), 120 mg every 4 weeks (120 Q4W) or placebo. Primary endpoint was proportion achieving SLE Responder Index 5 (SRI-5) improvement at week 52. RESULTS: Clinical characteristics were balanced across groups. The primary endpoint was met with 120 Q2W (38.4% vs 27.7%, placebo; p=0.002), but not with the less frequent 120 Q4W regimen (34.8%, p=0.051). Although key secondary endpoints (time to severe flare, corticosteroid sparing and fatigue) were not met, patients treated with tabalumab had greater SRI-5 response rates in a serologically active subset and improvements in more stringent SRI cut-offs, SELENA-SLEDAI, Physician's Global Assessment, anti-double-stranded DNA antibodies, complement, total B cells and immunoglobulins. The incidences of deaths, serious adverse events (AEs), and treatment-emergent AEs were similar in the 120 Q2W, 120 Q4W and placebo groups, but depression and suicidal ideation, albeit rare events, were more commonly reported with tabalumab. CONCLUSION: SRI-5 was met with 120 Q2W and although key secondary endpoints were not met, numerous other secondary endpoints significantly improved in addition to pharmacodynamic evidence of BAFF pathway blockade. The safety profile for tabalumab was similar to placebo, except for depression and suicidality, which were uncommon. TRIAL REGISTRATION NUMBER: NCT01205438.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Factor Activador de Células B/antagonistas & inhibidores , Lupus Eritematoso Sistémico/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anticuerpos Antinucleares/sangre , Anticuerpos Monoclonales Humanizados , Autoanticuerpos/sangre , Factor Activador de Células B/administración & dosificación , Linfocitos B/metabolismo , Biomarcadores/sangre , Población Negra , Complemento C3/metabolismo , Complemento C4/metabolismo , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Esquema de Medicación , Femenino , Humanos , Inyecciones Subcutáneas , Lupus Eritematoso Sistémico/etnología , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Adulto Joven
2.
Lupus ; 25(14): 1597-1601, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27220348

RESUMEN

INTRODUCTION: Tabalumab is a monoclonal antibody that neutralizes membrane and soluble B-cell activating factor. Two 52-week, randomized, double-blind, placebo controlled phase 3 trials evaluated the safety and efficacy of tabalumab in systemic lupus erythematosus. METHODS: Patients with moderate to severe active systemic lupus erythematosus (without severe active lupus nephritis) were randomly assigned 1:1:1 to receive tabalumab (120 mg subcutaneously every 2 or 4 weeks) or placebo for 52 weeks. Serum creatinine concentration, estimated glomerular filtration rate, urine protein/creatinine ratio, renal flares and renal adverse events were determined monthly. Data were analyzed for the intent-to-treat population and for intent-to-treat patients with baseline urine protein/creatinine ratio >20 mg/mmol (intent-to-treat plus urine protein/creatinine ratio). RESULTS: The trials enrolled 2262 patients. At baseline, demographics, systemic lupus erythematosus disease activity, serum creatinine concentration, estimated glomerular filtration rate and urine protein/creatinine ratio were similar among the treatment arms (with the exception of disease duration). In the intent-to-treat and intent-to-treat plus urine protein/creatinine ratio populations, there were no differences between the arms in the baseline-to-endpoint change in serum creatinine concentration, glomerular filtration rate, urine protein/creatinine ratio, or renal flare rates. Tabalumab resulted in a significant B-cell reduction and decreased immunoglobulin G levels at both doses. CONCLUSIONS: Compared to placebo, tabalumab did not significantly affect the serum creatinine concentration, glomerular filtration rate, urine protein/creatinine ratio, or renal flare rates over 1 year in intent-to-treat or intent-to-treat plus urine protein/creatinine ratio patients. There were no significant renal safety signals.ClinicalTrials.gov identifiers: NCT01205438 and NCT01196091 Lupus (2016) 25, 1597-1601.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Linfocitos B/efectos de los fármacos , Riñón/efectos de los fármacos , Lupus Eritematoso Sistémico/tratamiento farmacológico , Adulto , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados , Factor Activador de Células B/antagonistas & inhibidores , Creatinina/sangre , Método Doble Ciego , Esquema de Medicación , Femenino , Humanos , Inmunoglobulina G/sangre , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Estados Unidos
3.
Proc Natl Acad Sci U S A ; 106(23): 9131-4, 2009 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-19506260

RESUMEN

An intense investigation of possible non-Fermi liquid states of matter has been inspired by two of the most intriguing phenomena discovered in the past quarter century, namely, high-temperature superconductivity and the fractional quantum Hall effect. Despite enormous conceptual strides, these two fields have developed largely along separate paths. Two widely employed theories are the resonating valence bond theory for high-temperature superconductivity and the composite fermion theory for the fractional quantum Hall effect. The goal of this perspective article is to note that they subscribe to a common underlying paradigm: They both connect these exotic quantum liquids to certain ordinary Fermi liquids residing in unphysical Hilbert spaces. Such a relation yields numerous nontrivial experimental consequences, exposing these theories to rigorous and definitive tests.

4.
J Exp Med ; 163(2): 262-9, 1986 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-3484778

RESUMEN

The diversity of the IgG antibody induced by immunization of human infants and children with conjugate vaccines, composed of oligosaccharides prepared from the Haemophilus influenzae b capsular polysaccharide (CP) and covalently linked to diphtheria toxoids, was studied by analytical IEF. The antibody response was similar, in the degree of restriction, to that observed in the antibody response of older children to immunization with the CP alone. The booster responses induced by reimmunization with conjugate vaccines were accompanied by increases predominantly in the IgG antibody clonotypes expressed after the priming dose of vaccine. After a series of conjugate immunizations, immunization with isolated CP boosted the antibody titer and increased expression from all the clonotypes that were expressed after conjugate immunization. These findings suggest that the conjugate vaccines are acting on a limited number of human B cell clones that are preferentially restimulated after reimmunization. Little evidence of antigen-specific B cell recruitment was found. In addition, the ability of isolated CP immunization to restimulate the same B cell clone indicates that the responding B cell has matured and suggests a linear rather than a dual developmental pathway for the B cell participating in this human antibody response.


Asunto(s)
Anticuerpos Antibacterianos/biosíntesis , Vacunas Bacterianas/inmunología , Vacunas contra Haemophilus , Haemophilus influenzae/inmunología , Inmunoglobulina G/biosíntesis , Polisacáridos Bacterianos , Factores de Edad , Cápsulas Bacterianas , Preescolar , Toxoide Diftérico/inmunología , Humanos , Inmunización , Lactante , Focalización Isoeléctrica
5.
Diabet Med ; 27(10): 1168-73, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20854385

RESUMEN

AIMS: Transient nausea and, to a lesser extent, vomiting are common adverse effects of exenatide that can be mitigated by dose titration and usually do not result in treatment discontinuation. This retrospective analysis of data from a phase 1, open-label, parallel-group, single-dose study in healthy subjects evaluated the effect of oral anti-emetics on exenatide-associated nausea and vomiting and on the pharmacokinetics of exenatide. METHODS: A single subcutaneous dose (10 µg) of exenatide was administered to 120 healthy subjects (19-65 years, BMI 23-35 kg/m(2) ). Incidences of nausea and vomiting were compared between 60 subjects premedicated with two oral anti-emetics 30 min before the exenatide dose and 60 non-premedicated subjects. Similarly, the area under the concentration-time curve (AUC) and the maximum observed concentration (C(max) ) of plasma exenatide concentrations over 8 h post-dose were compared. RESULTS: Among all subjects [61% male, 32 ± 12 years, body mass index (BMI) 29.1 ± 3.4 kg/m(2) (mean ± sd)], mild to moderate nausea was the most frequent adverse event after exenatide dosing. Vomiting was also observed. Subjects premedicated with anti-emetics experienced significantly less nausea and vomiting (16.7 and 6.7%, respectively) vs. non-premedicated subjects (61.7 and 38.3%, respectively; P-value <0.0001 for both nausea and vomiting). The mean area under the concentration-time curve and the maximum observed concentration AUC and C(max) of plasma exenatide concentrations during 8 h post-dose were not significantly different between groups. CONCLUSION: Administration of oral anti-emetics before a single 10-µg exenatide dose was associated with significant reductions in treatment-emergent nausea and vomiting, with no discernible effect on the pharmacokinetics of exenatide. Use of anti-emetic therapy may provide a short-term strategy to minimize the nausea and vomiting associated with exenatide treatment.


Asunto(s)
Antieméticos/uso terapéutico , Hipoglucemiantes/farmacocinética , Náusea/prevención & control , Péptidos/uso terapéutico , Ponzoñas/uso terapéutico , Vómitos/tratamiento farmacológico , Administración Oral , Adulto , Anciano , Antieméticos/administración & dosificación , Antieméticos/farmacocinética , Área Bajo la Curva , Índice de Masa Corporal , Relación Dosis-Respuesta a Droga , Exenatida , Femenino , Humanos , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/efectos adversos , Inyecciones Subcutáneas , Masculino , Persona de Mediana Edad , Náusea/inducido químicamente , Péptidos/efectos adversos , Péptidos/farmacocinética , Estados Unidos , Ponzoñas/efectos adversos , Ponzoñas/farmacocinética , Vómitos/inducido químicamente , Adulto Joven
6.
Science ; 235(4793): 1196-8, 1987 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-17818979

RESUMEN

The oxide superconductors, particularly those recently discovered that are based on La(2)CuO(4), have a set of peculiarities that suggest a common, unique mechanism: they tend in every case to occur near a metal-insulator transition into an odd-electron insulator with peculiar magnetic properties. This insulating phase is proposed to be the long-sought "resonating-valence-bond" state or "quantum spin liquid" hypothesized in 1973. This insulating magnetic phase is favored by low spin, low dimensionality, and magnetic frustration. The preexisting magnetic singlet pairs of the insulating state become charged superconducting pairs when the insulator is doped sufficiently strongly. The mechanism for superconductivity is hence predominantly electronic and magnetic, although weak phonon interactions may favor the state. Many unusual properties are predicted, especially of the insulating state.

7.
Science ; 256(5063): 1526-31, 1992 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-17836318

RESUMEN

Analysis of the many experiments on high-temperature superconductivity indicate several essential aspects of any theory. The conductivity and other transport properties as a function of disorder, temperature, and frequency point to a non-Fermi liquid-like behavior, whereas photoemission experiments and magnetic properties indicate the presence of a Fermi surface in momentum space. To reconcile this apparent contradiction, a new type of electron liquid, called a Luttinger liquid, has been postulated, and the present article aims to show the need for this postulate. Theory and experiment indicate that the suitable phenomenological electronic structure model of the CuO layers is that of the one-band Hubbard model. It is also argued that experiment clearly indicates that interlayer interactions strongly affect the superconducting transition temperature, T(c), consistent with the fact that no theoretical calculations on two-dimensional Hubbard models have resulted in the prediction of high transition temperatures, and that anyon models are not favored by experiment.

8.
Science ; 268(5214): 1154-5, 1995 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-17840629

RESUMEN

Recent c axis-polarized infrared measurements in the high-transition temperature (high-T(c)) cuprate superconductor (La,Sr)(2)CuO(4) can be interpreted on the basis that the entire condensation energy comes from the interlayer Josephson coupling. This gives a parameter-free determination of penetration depth lambda and coherence length xi for this superconductor that are in agreement with experiment.

9.
Science ; 261(5119): 337-40, 1993 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-17836845

RESUMEN

A quantitative analysis of a recent model of high-temperature superconductors based on an interlayer tunneling mechanism is presented. This model can account well for the observed magnitudes of the high transition temperatures in these materials and implies a gap that does not change sign, can be substantially anisotropic, and has the same symmetry as the crystal. The experimental consequences explored so far are consistent with the observations.

10.
J Clin Invest ; 83(6): 2085-92, 1989 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2656762

RESUMEN

Plasma prorenin levels are elevated in normal pregnant women. Current evidence suggests renin production by tissues of the uteroplacental unit contribute to this elevation. The purpose of this investigation was to define the source of renin biosynthesis within the human uteroplacental unit and to characterize the renin produced. RNA extraction and Northern blot analysis consistently demonstrated renin mRNA expression in uterine lining both in the pregnant (decidua) and nonpregnant states (endometrium) and in fetal chorion laeve, which is inseparable from the decidua. In contrast, renin mRNA expression was not detected in basal plate and intertwin chorion (which is separate from decidua), amnion, myometrium, or placental villi. The total renin content in decidual homogenates was two- to threefold greater than in endometrial homogenates, and cultured human decidual cells produced significantly more total renin than cultured human endometrial cells, suggesting that pregnancy enhanced renin production by the cells lining the uterus. Immunoblot analysis and [3H]leucine incorporation identified 47,000-mol wt prorenin as the major form of renin produced by cultured human decidual cells. These studies indicate that maternal decidua is the major source of prorenin in the uteroplacental unit.


Asunto(s)
Decidua/enzimología , Renina/aislamiento & purificación , Adulto , Northern Blotting , Células Cultivadas , Corion/enzimología , Medios de Cultivo/análisis , Decidua/citología , Endometrio/enzimología , Femenino , Regulación de la Expresión Génica , Humanos , Immunoblotting , Embarazo , Renina/biosíntesis , Renina/genética
11.
J Phys Condens Matter ; 29(4): 045401, 2017 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-27875329

RESUMEN

Using molecular simulation, we determine the critical properties of Si as well as the loci for several remarkable thermodynamic contours spanning the supercritical region of the phase diagram. We consider a classical three-body potential as well as a quantum (tight-binding) many-body model, and determine the loci for the ideality contours, including the Zeno line and the H line of ideal enthalpy. The two strategies (classical or quantum) lead to strongly asymmetric binodals and to critical properties in good agreement with each other. The Zeno and H lines are found to remain linear over a wide temperature interval, despite the changes in electronic structure undergone by the fluid along these contours. We also show that the classical and quantum model yield markedly different results for the parameters defining the H line, the exponents for the power-laws underlying the line of minima for the isothermal enthalpy and for the density required to achieve ideal behavior, most notably for the enthalpy.

12.
Arch Intern Med ; 148(2): 397-401, 1988 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-3277563

RESUMEN

We found that nearly 10% of 142 patients with systemic lupus erythematosus (SLE) had persistent, unexplained hyperkalemia. Renal mineralocorticoid resistance has been suggested to account for the hyperkalemia in SLE. We studied the renin-aldosterone response to intravenous furosemide (60 mg) and upright posture and the renin response to converting enzyme inhibition (captopril, 50 mg) and upright posture in five patients with SLE and hyperkalemia (group 1) and five normokalemic patients with SLE (group 2). Renal function was comparable. Plasma chloride level was higher and bicarbonate level slightly lower in group 1 than in group 2. Plasma cortisol level was normal in all patients. None of the patients was receiving nonsteroidal anti-inflammatory drugs or corticosteroids at the time of study. Basal plasma renin concentration and plasma aldosterone level were not significantly different between the two groups, although both tended to be higher in group 2. However, four of the five patients in group 1 had significantly blunted renin response to captopril compared with group 2. The same four patients also had blunted renin and aldosterone responses to furosemide. Thus, the majority of hyperkalemic patients with SLE had an impaired renin and aldosterone response to stimulation. We conclude that hyporeninemic hypoaldosteronism plays a key role in the pathogenesis of hyperkalemia in SLE.


Asunto(s)
Hiperpotasemia/etiología , Lupus Eritematoso Sistémico/complicaciones , Adulto , Aldosterona/sangre , Angiotensina I/sangre , Bicarbonatos/sangre , Captopril/farmacología , Cloruros/sangre , Precursores Enzimáticos/sangre , Femenino , Furosemida/farmacología , Humanos , Hiperpotasemia/sangre , Lupus Eritematoso Sistémico/sangre , Masculino , Persona de Mediana Edad , Potasio/sangre , Potasio/orina , Renina/sangre , Estimulación Química
13.
Hypertension ; 20(2): 253-63, 1992 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1639468

RESUMEN

Hypertension is a major factor that contributes to the development of the vascular complications of diabetes mellitus, which primarily include atherosclerosis, nephropathy, and retinopathy. The mechanism of the pathophysiological effects of hypertension lies at the cellular level in the blood vessel wall, which intimately involves the function and interaction of the endothelial and vascular smooth muscle cells. Both hypertension and diabetes mellitus alter endothelial cell structure and function. In large and medium size vessels and in the kidney, endothelial dysfunction leads to enhanced growth and vasoconstriction of vascular smooth muscle cells and mesangial cells, respectively. These changes in the cells of smooth muscle lineage play a key role in the development of both atherosclerosis and glomerulosclerosis. In diabetic retinopathy, damage and altered growth of retinal capillary endothelial cells is the major pathophysiological insult leading to proliferative lesions of the retina. Thus, the endothelium emerges as a key target organ of damage in diabetes mellitus; this damage is enhanced in the presence of hypertension. An overall approach to the understanding and treatment of diabetes mellitus and its complications will be to elucidate the mechanisms of vascular disease and endothelial cell dysfunction that occur in the setting of hypertension and diabetes.


Asunto(s)
Complicaciones de la Diabetes , Endotelio Vascular/fisiología , Hipertensión/complicaciones , Arteriosclerosis/etiología , Diabetes Mellitus/patología , Diabetes Mellitus/fisiopatología , Nefropatías Diabéticas/etiología , Retinopatía Diabética/etiología , Endotelio Vascular/patología , Femenino , Humanos , Persona de Mediana Edad
14.
Hypertension ; 21(1): 29-35, 1993 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8418021

RESUMEN

Angiotensin II, a potent vasoconstrictor and known growth factor for vascular smooth muscle cells, has been implicated in the development of glomerulosclerosis. Because mesangial cell growth plays a critical role in the glomerulosclerotic process, the objective of this study was to determine the direct effect of long-term (48-hour) angiotensin II treatment on the growth of cultured murine mesangial cells. Subconfluent, quiescent adult murine mesangial cells were treated for 48 hours with media containing angiotensin II with and without its specific inhibitor losartan. In comparison to cells treated with serum-free medium, cells treated with serum plus insulin demonstrated a significant increase in cell number (1.93 +/- 0.1 times control, p < 0.05), [3H]thymidine incorporation per 10(5) cells (2.29 +/- 0.12 times control, p < 0.05), [3H]leucine incorporation per 10(5) cells (1.81 +/- 0.18 times control, p < 0.05), and total protein content per 10(5) cells (1.65 +/- 0.07 times control, p < 0.05). In contrast, cells treated with angiotensin II (10(-6) M) had no significant increase in cell number (0.84 +/- 0.01 times control) or [3H]thymidine incorporation per 10(5) cells (1.23 +/- 0.12 times control) but demonstrated a significant increase in [3H]leucine incorporation per 10(5) cells (1.61 +/- 0.09 times control) and total protein content per 10(5) cells (1.38 +/- 0.04 times control). Pretreatment with losartan blocked 56% of the angiotensin II-induced increase in [3H]leucine incorporation and 84% of the angiotensin II-induced increase in total protein content.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Angiotensina II/farmacología , Mesangio Glomerular/efectos de los fármacos , Animales , Recuento de Células , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , ADN/biosíntesis , Mesangio Glomerular/metabolismo , Mesangio Glomerular/patología , Hipertrofia , Ratones , Biosíntesis de Proteínas , Proteínas/análisis
15.
J Clin Endocrinol Metab ; 69(3): 518-22, 1989 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2503532

RESUMEN

Recent observations implicate angiotensin-II (AII) as a possible PRL-releasing factor. These observations prompted us to investigate the role of the renin-angiotensin system in PRL release in man. Nine normal volunteers ingesting a 20-40 mmol/day sodium, 70 mmol/day potassium diet and eight normal volunteers ingesting a 120 mmol/day sodium, 70 mmol/day potassium diet were infused with metoclopramide (2.5 mg over 1 min) and later with TRH (500 micrograms), two agents known to cause PRL release. The infusions were repeated after 36 h of oral administration of converting enzyme inhibitor [CEI; captopril (50 mg, orally, four times daily) or enalapril (5 mg, orally, twice daily)]. On a separate occasion, AII was infused at 10 ng/kg.h for 1 h into normal volunteers on normal salt diet. CEI administration lowered mean arterial pressure by 6-7 mm Hg and stimulated the release of active renin. The PRL responses on low and normal salt diet as well as before and after CEI were not statistically different. There was also no difference in the PRL responses of patients placed on captopril vs. those on enalapril. AII increased blood pressure by 11-25 mm Hg, but did not increase PRL significantly above basal concentrations during the control dextrose infusion. Five hyperprolactinemic volunteers were also given CEI for up to 4 weeks. They demonstrated no significant change in serum PRL levels. We conclude that AII in the pituitary does not significantly alter either basal PRL levels or metoclopramide- and TRH-induced PRL responses in normal subjects on low and high salt diets. In addition, CEI is not a useful therapy in patients with pathological hyperprolactinemia. These findings, however, do not exclude a role for AII in physiological regulation, since CEI does not cross the blood-brain barrier and would not be expected to alter hypothalamic AII.


Asunto(s)
Captopril/farmacología , Hiperprolactinemia/sangre , Prolactina/metabolismo , Adulto , Angiotensina II/farmacología , Presión Sanguínea/efectos de los fármacos , Dieta , Dieta Hiposódica , Femenino , Humanos , Masculino , Metoclopramida/farmacología , Prolactina/sangre , Valores de Referencia , Renina/sangre , Sodio/sangre , Hormona Liberadora de Tirotropina/farmacología
16.
J Clin Endocrinol Metab ; 85(1): 214-8, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10634389

RESUMEN

C-Reactive protein and homocysteine are independent risk factors for the development of cardiovascular disease. This study compared the effects of hormone replacement therapy (HRT) and raloxifene on serum C-reactive protein and homocysteine levels as markers of cardiovascular risk in healthy postmenopausal women. Healthy postmenopausal women (n = 390) were enrolled in a double blind, randomized, placebo-controlled, 6-month trial at eight out-patient sites in the United States. Women were randomly assigned to receive continuous combined HRT (0.625 mg/day conjugated equine estrogen and 2.5 mg/day medroxyprogesterone acetate), raloxifene (60 or 120 mg/day), or placebo for 6 months. C-Reactive protein and homocysteine were measured in baseline and 6-month serum samples. HRT increased C-reactive protein levels by 84% (P<0.001), whereas raloxifene (60 and 120 mg/day) had no significant effect (-6% and -4%;, respectively; P>0.2). Raloxifene (60 and 120 mg/day) significantly lowered serum levels ofhomocysteine by 8% (P = 0.014) and 6% (P = 0.024), respectively, similar to the 7% (P = 0.014) reduction obtained with HRT. We conclude that HRT and raloxifene lower serum homocysteine levels to a comparable extent in postmenopausal women. Whereas cardiovascular risk predicted by C-reactive protein in healthy postmenopausal women is not influenced by raloxifene, the relationship between elevated C-reactive protein levels with HRT and cardiovascular disease events requires further study.


Asunto(s)
Proteína C-Reactiva/metabolismo , Terapia de Reemplazo de Estrógeno , Homocisteína/sangre , Clorhidrato de Raloxifeno/farmacología , Anciano , Método Doble Ciego , Femenino , Fibrinógeno/metabolismo , Humanos , Lípidos/sangre , Persona de Mediana Edad , Posmenopausia/metabolismo , Estudios Prospectivos , Factores de Riesgo
17.
Medicine (Baltimore) ; 68(5): 257-68, 1989 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2677594

RESUMEN

Although renin-secreting tumors are rare, they must be considered in the differential diagnosis of hypertension associated with hypokalemia, which occurs commonly in the hypertensive population. The finding of an ovarian renin-secreting tumor emphasizes the potential importance of the ovary as an extrarenal source of renin; the local ovarian renin-angiotensin system may play a key role in reproductive function by regulating vascular reactivity, local blood flow, steroidogenesis and other physiologic effects. In the illustrative case presented, a renin-secreting ovarian leiomyosarcoma was obtained from a women who presented with hypertension and hypokalemia. Plasma prorenin levels were markedly elevated. Tumor excision was quickly followed by a fall in prorenin levels and tumor recurrence was accompanied by an increase in prorenin levels. Active renin concentration in the tumor homogenates was similar to that found in kidney homogenates while the tissue prorenin concentration was approximately 20 times that found in kidney tissue. When cultured for up to 4 weeks, ovarian tumor cells secreted greater than 95% prorenin. Immunoblot analysis demonstrated that tumor renin had a molecular weight of 47,000, similar to that of human recombinant prorenin. Immunohistochemical staining of tumor tissue with antibodies against human renal renin at the electron microscopic level demonstrated the presence of renin primarily in membrane-bound vesicles and rarely in dense-core secretory granules. These findings suggest that prorenin in this ovarian tumor was secreted by the constitutive pathway, which is mediated by these amorphous vesicles.


Asunto(s)
Hipertensión/metabolismo , Leiomiosarcoma/metabolismo , Neoplasias Ováricas/metabolismo , Ovario/metabolismo , Renina/metabolismo , Anciano , Femenino , Humanos , Hipertensión/complicaciones , Hipopotasemia/complicaciones , Hipopotasemia/metabolismo , Immunoblotting , Inmunohistoquímica , Leiomiosarcoma/complicaciones , Microscopía Electrónica , Neoplasias Ováricas/complicaciones , Renina/biosíntesis , Células Tumorales Cultivadas
18.
Am J Cardiol ; 72(20): 14H-21H, 1993 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-8285177

RESUMEN

Antihypertensive treatment in the diabetic patient is a critical issue because hypertension has an impact on all of the vascular complications of diabetes, including nephropathy, retinopathy, atherosclerosis, and left ventricular hypertrophy. These complications are a consequence of altered endothelial-vascular smooth muscle interrelations that ultimately enhance vasoconstriction and alter the remodeling processes in the vascular wall. Several observations suggest that the renin-angiotensin system (RAS) may be an important contributor to these processes in diabetes mellitus. In both animal and human studies, angiotensin-converting enzyme (ACE) inhibitors have been demonstrated to slow the progression of glomerulosclerosis, prevent abnormal remodeling processes in the heart following injury, and slow the progression of atherosclerosis. In particular, ACE inhibitors appear to protect the kidney more than would be expected from simply the lowering of blood pressure and decreasing of intraglomerular pressure, possibly because angiotensin II has both hemodynamic and direct effects on the glomerulus. Paradoxically, however, the activity of the circulating RAS is low in diabetic patients. Part of these seemingly inconsistent observations may be due to (1) potential activity of tissue RASs, (2) increased sensitivity to angiotensin II in diabetes, or (3) an effect of ACE inhibition on other systems in addition to the RAS. Investigation of these mechanisms will be important in determining the therapeutic role of inhibition of the RAS in diabetes mellitus.


Asunto(s)
Angiopatías Diabéticas/fisiopatología , Hipertensión/fisiopatología , Sistema Renina-Angiotensina/fisiología , Animales , Nefropatías Diabéticas/fisiopatología , Endotelio Vascular/fisiopatología , Humanos , Hipertrofia Ventricular Izquierda/fisiopatología
19.
Am J Cardiol ; 66(19): 1342-7, 1990 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-2244565

RESUMEN

The effect of the direct renin inhibitor enalkiren (Abbott Laboratories) was examined in 8 healthy patients with essential hypertension. With an unrestricted sodium diet, plasma renin concentration was inhibited within 10 minutes by intravenous enalkiren and remained essentially undetectable for greater than or equal to 6 hours (11.9 +/- 4 to 1.0 +/- 0.6 ng angiotensin I/ml/hour, p less than 0.05). Mean arterial blood pressure declined gradually (108 +/- 5 to 84 +/- 4 mm Hg, p = 0.02), as did plasma aldosterone concentration (14.4 +/- 3.8 to 4.4 +/- 0.8 ng/dl, p = 0.03), whereas plasma immunoreactive active renin concentration increased progressively (35 +/- 14 to 160 +/- 60 pg/ml, p greater than 0.05). Urinary excretion of the stable metabolite of prostacyclin (6-keto-prostaglandin F1 alpha) decreased slightly, but not significantly (42 +/- 10 to 33 +/- 11 ng/g creatinine, p = 0.13). The addition of a diuretic decreased baseline blood pressure and increased baseline plasma renin and aldosterone values. Blood pressure responses to enalkiren were slightly (though not significantly) greater than those observed before diuretic administration. We conclude that enalkiren is effective in decreasing blood pressure and in inhibiting the renin system, without significantly altering urinary prostacyclin excretion, in patients with essential hypertension. These results suggest that the renin system contributes to the maintenance of elevated blood pressure in some patients with essential hypertension.


Asunto(s)
Dipéptidos/uso terapéutico , Hipertensión/tratamiento farmacológico , Renina/antagonistas & inhibidores , Adulto , Aldosterona/sangre , Dipéptidos/orina , Epoprostenol/orina , Femenino , Humanos , Hipertensión/metabolismo , Masculino , Persona de Mediana Edad , Renina/sangre
20.
Am J Cardiol ; 88(4): 392-5, 2001 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-11545760

RESUMEN

Raloxifene is a selective estrogen receptor modulator that lowers total and low-density lipoprotein (LDL) cholesterol, reduces the risk of vertebral fracture, and is associated with a reduced incidence of invasive breast cancer in postmenopausal women with osteoporosis. The Raloxifene Use for The Heart (RUTH) trial is designed to determine whether raloxifene 60 mg/day compared with placebo: (1) lowers the risk of the coronary events (coronary death, nonfatal myocardial infarction [MI], or hospitalized acute coronary syndromes other than MI); and (2) reduces the risk of invasive breast cancer in women at risk for a major coronary event. RUTH is a double-blind, placebo-controlled, randomized clinical trial of 10,101 postmenopausal women aged > or =55 years from 26 countries. Women are eligible for randomization if they are postmenopausal and have documented coronary heart disease (CHD), peripheral arterial disease, or multiple risk factors for CHD. Use of estrogen within the previous 6 months is an exclusion factor. The study will be terminated after a minimum of 1,670 participants experience a primary coronary end point. Secondary end points include cardiovascular death, myocardial revascularization, noncoronary arterial revascularization, stroke, all-cause hospitalization, all-cause mortality, all breast cancers, clinical fractures, and venous thromboembolic events, in addition to the individual components of the composite primary coronary end point. RUTH will provide important information about the risk-benefit ratio of raloxifene in preventing acute coronary events and invasive breast cancer, as well as information about the natural history of CHD in women at risk of major coronary events.


Asunto(s)
Neoplasias de la Mama/prevención & control , Enfermedad Coronaria/prevención & control , Clorhidrato de Raloxifeno/uso terapéutico , Proyectos de Investigación , Moduladores Selectivos de los Receptores de Estrógeno/uso terapéutico , Angina Inestable/prevención & control , Método Doble Ciego , Femenino , Humanos , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Infarto del Miocardio/prevención & control , Osteoporosis Posmenopáusica/prevención & control , Ensayos Clínicos Controlados Aleatorios como Asunto
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