RESUMEN
Hurricanes severely damaged a mangrove forest in a UNESCO biosphere reserve in the U.S. Virgin Islands. The system has yet to recover and when alternative habitats have been destroyed, it is shown that juvenile fishes will hyperutilize seagrass beds at densities significantly greater than in areas that maintain functioning mangroves. Despite over a decade of recovery time, the affected mangrove system remains inhospitable to juvenile fishes.
Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Peces , Rhizophoraceae , Animales , Tormentas Ciclónicas , Dinámica Poblacional , Islas Virgenes de los Estados UnidosRESUMEN
This study has been designed to evaluate the relationship among transforming growth factor beta1 (TGFbeta1) and some measurements of diastolic function in a population of hypertensive subjects with normal left ventricular ejection fraction. We studied 67 hypertensive outpatients who according to their BMI levels were subdivided into three groups: lean (L), overweight (OW) and obese (OB) hypertensives (HT). Circulating TGFbeta1 and M- and B-mode echocardiography was determined. All hypertensives were further subgrouped, according to European Society of Cardiology Guidelines, into two subsets of patients with normal diastolic function or with diastolic dysfunction. Prevalence of left ventricular hypertrophy (LVH) was determined in all the groups. TGFbeta1, left ventricular mass (LVM), LVM/h(2.7), E-wave deceleration time and isovolumic relaxation time (IVRT) were significantly (P < 0.005) higher and E/A velocity ratio was significantly (P < 0.05) lower in OW-HT and OB-HT than in L-HT. Prevalence of LVH was significantly higher (P < 0.03) in group OB-HT than in L-HT. TGFbeta1 (P < 0.004), LVM/h(2.7) (P < 0.001) and prevalence of LVH were (P < 0.01) significantly higher in hypertensives with diastolic dysfunction than hypertensives with normal diastolic function. TGFbeta1 levels were positively correlated with BMI (r = 0.60; P < 0.0001), LVM/h(2.7) (r = 0.28; P < 0.03), IVRT (r = 0.30; P < 0.02) and negatively with E/A ratio (r = -0.38; P < 0.002) in all HT. Multiple regression analysis indicated that TGFbeta1, BMI and IVRT were independently related to E/A ratio explaining 71% of its variability (r = 0.84; P < 0.0001). This relationship was independent of LVH, age and HR suggesting that TGFbeta1 overproduction may be considered a pathophysiological mechanism in the development of left ventricular filling abnormalities in obesity-associated hypertension.
Asunto(s)
Hipertensión/complicaciones , Hipertrofia Ventricular Izquierda/complicaciones , Contracción Miocárdica/fisiología , Obesidad/complicaciones , Factor de Crecimiento Transformador beta/metabolismo , Disfunción Ventricular Izquierda/etiología , Adulto , Anciano , Biomarcadores/sangre , Diástole , Ecocardiografía , Ensayo de Inmunoadsorción Enzimática , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Hipertensión/sangre , Hipertensión/fisiopatología , Hipertrofia Ventricular Izquierda/sangre , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Persona de Mediana Edad , Obesidad/sangre , Obesidad/fisiopatología , Análisis de Regresión , Factores de Riesgo , Volumen Sistólico/fisiología , Factor de Crecimiento Transformador beta1 , Disfunción Ventricular Izquierda/sangre , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
Despite the fact that it is known that hypertension may be associated to early atherosclerosis manifestations, few data are to date available on the relationship between early carotid abnormalities and left ventricular diastolic dysfunction. To address this issue, 142 hypertensive patients (64 females and 78 males) younger than 55 years, at the first diagnosis of mild-to-moderate essential hypertension (WHO/ISH criteria), were selected from a database consisting of 3541 subjects referred to ultrasound cardiovascular laboratory in the last 5 years. Carotid intima-media thickness (IMT) was detected by high-resolution vascular ultrasound and left ventricular structure and function by the use of Doppler echocardiography. According to carotid IMT values, all patients were subgrouped into two groups consisting of 89 (62.6%) pts with IMT > or = 1 mm (A) and 53 (37.4%) pts with IMT < 1 mm (B). Our results show that isovolumic relaxation time (IVRT), deceleration time of E velocity (EDT) and left ventricular relative wall thickness (LV-RWT) were significantly (P < 0.05) higher in group A (IVRT 112 +/- 8.9 ms; EDT 288 +/- 21.8 ms; LV-RWT 0.40 +/- 0.08) than in group B (IVRT 92.3 +/- 4.6 ms; EDT 203.3 +/- 27.01 ms; LV- RWT 0.37 +/- 0.06). Moreover, the prevalence of left ventricular hypertrophy (LVH) was significantly (P < 0.01) higher in group A (30/89; 33.7%) than in group B (8/53; 15%). A positive correlation (P < 0.001) between IMT, EDT and IVRT was found only in hypertensives without LVH. These results are consistent with the indication that IMT evaluation has to be recommended both in hypertensive patients with LVH and in those without LVH, but with left ventricular diastolic dysfunction. This approach might improve the prognostic stratification of hypertensive subjects and it might be suitable to recognize the subset of patients at a higher risk of cardiovascular disease or events early.
Asunto(s)
Enfermedades de las Arterias Carótidas/complicaciones , Hipertensión/complicaciones , Disfunción Ventricular Izquierda/complicaciones , Adulto , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/fisiopatología , Diástole , Femenino , Humanos , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Factores de Tiempo , Ultrasonografía , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
Systolic blood pressure (SBP) normally increases during exercise. This increase is frequently exaggerated in hypertensive individuals. The aim of our study was to evaluate the antihypertensive effects of losartan at peak exercise and on cardiac performance during the treadmill test in individuals with essential hypertension. Forty subjects with a mean age of 44.2 +/- 12.4 years and with mild-to-moderate essential hypertension were enrolled. After a 14-day washout period, all selected subjects were given a treadmill exercise test using the modified Bruce protocol for exercise. The test was performed at the end of the washout period (step 0), again after 1 month (step 1), after 3 months (step 2) and after 6 months (step 3) of losartan administration (50 mg/daily per oral). Heart rate, SBP and diastolic blood pressure (DBP) were measured at rest and at maximal exercise. Exercise duration and double product were also recorded. In all patients who completed the study, a significant reduction from baseline in SBP at rest was found at 3 and 6 months (p < 0.05). No significant reduction from baseline in SBP at peak exercise was observed. No significant changes from baseline were found in double product, DBP, heart rate or exercise time. The results of our study suggest that losartan is effective in reducing blood pressure only at rest but is unable to improve exercise BP response or cardiac performance in subjects with mild-to-moderate essential hypertension.
Asunto(s)
Sistema Cardiovascular/efectos de los fármacos , Prueba de Esfuerzo/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Losartán/farmacología , Adulto , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Prueba de Esfuerzo/estadística & datos numéricos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Humanos , Hipertensión/fisiopatología , Losartán/uso terapéutico , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
This double-blind crossover study was designed to compare the effects of felodipine and cilazapril on exercise performance in hypertensive patients. After a 2-week placebo run-in period, 40 patients with mild to moderate hypertension were randomized into two parallel groups to receive either felodipine (10 mg) or cilazapril (5 mg) for 4 weeks. After another 2-week washout period, treatments were then crossed over for a further 4-week study period. All patients were given an extensive rest and exercise evaluation at the end of the placebo period. Extensive rest and exercise evaluations were repeated after a 4-week treatment period and again after the second washout period and after the second 4-week treatment period. Before each exercise test, epinephrine, norepinephrine and dopamine plasma levels and plasma renin activity were measured. Two groups were similar at baseline for systolic and diastolic blood pressure and heart rate as well as for laboratory and hormonal variables and duration of exercise test. At the end of treatment diastolic blood pressure was significantly reduced in the felodipine group (p = 0.019). Duration of exercise test was longer than at baseline (p = 0.031) in the felodipine group. Plasma dopamine levels were significantly increased in the cilazapril group. Plasma renin activity significantly increased in the felodipine group. In conclusion, our data show that the two drugs have the same effectiveness in resting conditions but that felodipine is more effective in lowering maximum exercise diastolic blood pressure and in improving exercise time with an double product increase (not significant); it has no statistically significant effect on maximal exercise systolic blood pressure.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Bloqueadores de los Canales de Calcio/uso terapéutico , Cilazapril/uso terapéutico , Prueba de Esfuerzo , Felodipino/uso terapéutico , Hipertensión/tratamiento farmacológico , Estudios Cruzados , Método Doble Ciego , Hemodinámica/efectos de los fármacos , Humanos , Hipertensión/fisiopatologíaRESUMEN
Recent reports show that sumatriptan administration increases blood pressure and vascular resistance both in systemic and pulmonary circulation. This study was performed to evaluate by echo-Doppler technique the hemodynamic effects of subcutaneous sumatriptan administration. Forty-one migraine subjects (26 males, 15 females), mean age 36 +/- 2 years (range 36-39 years), and 20 healthy control subjects (14 males, six females), mean age 36 +/- 2 years (range 36-39 years) were randomized (double-blind) to receiving sumatriptan (group A) or placebo (group B). After a 2-week complete pharmacological washout, clinical examination, electrocardiogram, and Doppler echocardiography were performed at baseline, 15, 30, 45, and 60 min after sumatriptan or placebo administration. No significant differences were found between the two groups regarding Doppler echocardiographic parameters (aortic integral, pulmonary integral, end-systolic and end-diastolic diameters) and heart rate; only a slight but not significant increase in arterial blood pressure was observed in group A. Our data show that succinate sumatriptan can be used with safety in patients without hypertension and other cardiovascular disease.
Asunto(s)
Presión Sanguínea/efectos de los fármacos , Ecocardiografía Doppler , Frecuencia Cardíaca/efectos de los fármacos , Trastornos Migrañosos/tratamiento farmacológico , Sumatriptán/uso terapéutico , Vasoconstrictores/uso terapéutico , Adulto , Método Doble Ciego , Evaluación de Medicamentos , Femenino , Humanos , Infusiones Parenterales , Masculino , Sumatriptán/efectos adversosRESUMEN
Sumatriptan, a selective 5-hydroxy-triptamine (5-HT1) receptor agonist, has been used recently in the treatment of acute migraine. Some in vitro experiments suggested that sumatriptan has vasoactive properties in vascular beds distinct from cerebral circulation. In view of this we investigated the vascular effects of the standard 6 mg subcutaneous (s.c.) dose of sumatriptan, on the surface areas of the head using thermography, a simple and reliable method for detecting temperature changes. The head temperature of 127 patients (double-blind), 102 migraines (52 during headache attack and 50 headache-free) and 25 healthy control subjects were evaluated using thermography in basal condition and 30, 60, 90, and 120 min after s.c. sumatriptan injection of placebo. During the entire observation period systemic blood pressure (SBP), heart rate (HR) and continuous electrocardiogram (ECG) were detected automatically. A significant head temperature decrease was observed after s.c. sumatriptan administration, in both healthy controls and migraine subjects; placebo administration did not show any change of temperature. In migraine patients during headache attack, head temperature reduction corresponded to the relief of headache symptoms. This vasoconstrictor effect detected with thermography is not isolated to cranial circulation but it is also systemic. In fact, we observed a significant increase (p < 0.05) in both systolic and diastolic systemic blood pressure. No significant changes in heart rate and ECG abnormalities were otherwise detected. These findings suggest that sumatriptan is effective in the treatment of migraine attack, but it must be used with caution in migraines with concomitant hypertension.
Asunto(s)
Temperatura Corporal/efectos de los fármacos , Cabeza/irrigación sanguínea , Trastornos Migrañosos/tratamiento farmacológico , Sumatriptán/uso terapéutico , Vasoconstrictores/uso terapéutico , Adulto , Análisis de Varianza , Presión Sanguínea/efectos de los fármacos , Método Doble Ciego , Electrocardiografía , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Inyecciones Subcutáneas , Masculino , Persona de Mediana Edad , Sumatriptán/farmacología , Termografía , Vasoconstrictores/farmacologíaRESUMEN
BACKGROUND: So far, only a few and conflicting data are available about the possible correlation between Helicobacter pylori infection and disorders of gastrointestinal motility. METHODS: In the present study we have evaluated the interdigestive manometric recordings from the stomach and duodenum of 100 consecutive dyspeptic patients, to ascertain whether the absence of phase III of the migrating motor complex (MMC) might be associated with a different prevalence of H. pylori infection. All the patients who entered a protocol study for functional dyspepsia had endoscopic examinations of the upper gastrointestinal tract with at least two biopsy specimens from both the gastric antrum and corpus (for histologic evaluation, with search for Helicobacter-like organisms). Then, 240-min interdigestive manometric recordings, with evaluation of activity fronts (phase III of the MMC), starting from the stomach and the duodenum, were made. RESULTS AND CONCLUSIONS: The data obtained suggest that in patients without evidence of gastric phase III of MMC the prevalence of H. pylori colonization is significantly (P = 0.032) higher.
Asunto(s)
Dispepsia/microbiología , Dispepsia/fisiopatología , Infecciones por Helicobacter/epidemiología , Helicobacter pylori , Complejo Mioeléctrico Migratorio , Adulto , Estudios de Casos y Controles , Dispepsia/diagnóstico , Femenino , Gastritis/diagnóstico , Gastritis/epidemiología , Gastritis/microbiología , Infecciones por Helicobacter/diagnóstico , Humanos , Masculino , Manometría , PrevalenciaRESUMEN
Authors report their experience on self-grafting of the spleen on 3 patients, among which a 9-year-old child. The surgical method is easy and quick and in their opinion it has given satisfactory results. In fact, basing themselves on the computation of the platelets values close to normality have been observed.