The high surgical ligature of spermatic vessels modified Palomo and the antegrade sclerotherapy according to Tauber represent two therapeutic modalities at last assured. In the experience of the ...Author the surgical technique is better with regard to the appearance of relapsing varicocele and the mean operative time.
Baroreflex control of sympathetic activity is impaired in severe congestive heart failure (CHF), probably causing the marked sympathetic activation typical of this condition. Little information ...exists, however, as to whether baroreflex impairment and related sympathetic activation also occur in mild CHF.
We studied 19 patients (age, 57.5 +/- 2.2 years, mean +/- SEM) with CHF in New York Heart Association (NYHA) class III or IV and with a marked reduction in left ventricular ejection fraction (LVEF, 30.1 +/- 1.5% from echocardiography) and 17 age-matched patients with CHF in NYHA class I or II and with an only slightly reduced LVEF (44.9 +/- 3.3%) that never was < 40%. Seventeen age-matched healthy subjects served as control subjects. Primary measurements included beat-to-beat arterial blood pressure (with the Finapres technique), heart rate (from ECG), and postganglionic muscle sympathetic nerve activity (MSNA, from microneurography at the peroneal nerve). Measurements were performed at baseline and during baroreceptor stimulation (intravenous phenylephrine infusion), baroreceptor deactivation (intravenous nitroprusside infusion), and cold-pressor test. Baseline blood pressure was similar in the three groups, whereas heart rate was progressively greater from control subjects to patients with mild and severe CHF, MSNA (bursts per 100 heart beats) increased significantly and markedly from control subjects to patients with mild and severe CHF (47.1 +/- 2.9 versus 64.4 +/- 6.2 and 82.1 +/- 3.4, P < .05 and P < .01, respectively). Heart rate and MSNA were progressively reduced by phenylephrine infusion and progressively increased by nitroprusside infusion. Compared with control subjects, the responses were strikingly impaired in severe CHF patients, but a marked impairment also was seen in mild CHF patients. On average, baroreflex sensitivity in mild CHF patients was reduced by 59.1 +/- 5.5% (MSNA) and 64.8 +/- 4.8% (heart rate). In contrast, reflex responses to the cold-pressor test were similar in the three groups.
These results demonstrate that in mild CHF patients the baroreceptor inhibitor influence on heart rate and MSNA is already markedly impaired. This impairment may be responsible for the early sympathetic activation that occurs in the course of CHF.
Human obesity is characterized by profound alterations in the hemodynamic and metabolic states. Whether these alterations involve sympathetic drive is controversial. In 10 young obese subjects (body ...mass index, 40.5 plus/minus 1.2 kg/m, mean plus/minus SEM) with normal blood pressure and 8 age-matched lean normotensive control subjects, we measured beat-to-beat arterial blood pressure (Finapres technique), heart rate (electrocardiogram), postganglionic muscle sympathetic nerve activity (microneurography at the peroneal nerve), and venous plasma norepinephrine (high-performance liquid chromatography). The measurements were performed in baseline conditions and, with the exception of plasma norepinephrine, during baroreceptor stimulation and deactivation caused by increases and reductions of blood pressure via intravenous infusions of phenylephrine and nitroprusside. Baseline blood pressure and heart rate were similar in obese and control subjects. Plasma norepinephrine was also similar in the two groups. Muscle sympathetic nerve activity, however, was 38.6 plus/minus 5.1 bursts per minute in obese subjects and less than half that level in control subjects (18.7 plus/minus 1.3 bursts per minute), the difference being highly statistically significant (P < .02). Muscle sympathetic nerve activity and heart rate were reduced during phenylephrine infusion and increased during nitroprusside infusion, but the changes were about half as great in obese subjects as in control subjects. Thus, even in the absence of any blood pressure alteration, human obesity is characterized by a marked sympathetic activation, possibly because of an impairment of reflex sympathetic restraint. This may be involved in the high rate of hypertension and cardiovascular complications seen in obesity. (Hypertension. 1995;25part 1:560-563.)
The pressor and tachycardic effects of cigarette smoking are associated with an increase in plasma catecholamines, suggesting the dependence of these effects on adrenergic stimulation. Whether the ...stimulation occurs at a central or a peripheral level and whether reflex mechanisms are involved is unknown.
In nine normotensive healthy subjects (age, 33.0 +/- 3.5 years, mean +/- SEM), we measured blood pressure (Finapres device), heart rate (ECG), calf blood flow and vascular resistance (venous occlusion plethysmography), plasma norepinephrine and epinephrine (high-performance liquid chromatography assay), and postganglionic muscle sympathetic nerve activity (microneurography from the peroneal nerve) while subjects were smoking a filter cigarette (nicotine content, 1.1 mg) or were in control condition. Cigarette smoking (which raised plasma nicotine measured by high-performance liquid chromatography from 1.0 +/- 0.9 to 44.2 +/- 7.1 ng/mL) markedly and significantly increased mean arterial pressure (+13.2 +/- 2.3%), heart rate (+30.3 +/- 4.7%), calf vascular resistance (+12.1 +/- 4.9%), plasma norepinephrine (+34.8 +/- 7.0%), and plasma epinephrine (+90.5 +/- 39.0%). In contrast, muscle sympathetic nerve activity showed a marked reduction (integrated activity -31.8 +/- 5.1%, P < .01). The reduction was inversely related to the increase in mean arterial pressure (r = -.67, P < .05), but the slope of the relation was markedly less (-54.1 +/- 7.5%, P < .05) than that obtained by intravenous infusion of phenylephrine in absence of smoking. The hemodynamic and neurohumoral changes were still visible 30 minutes after smoking and occurred again on smoking a second cigarette. Sham smoking was devoid of any hemodynamic and neurohumoral effect.
These data support the hypothesis that in humans the sympathetic activation induced by smoking depends on an increased release and/or a reduced clearance of catecholamines at the neuroeffector junctions. Central sympathetic activity is inhibited by smoking, presumably via a baroreceptor stimulation triggered by the smoking-related pressor response. The baroreflex is impaired by smoking, however, indicating that partial inability to reflexly counteract the effect of sympathetic activation is also responsible for the pressor response.
Cirrhosis is associated with cardiovascular abnormalities. Scanty information is available as to whether these include left ventricle diastolic dysfunction and wall thickness increase. To this aim in ...27 cirrhotic patients with tense ascites, 17 cirrhotic patients with previous episodes of ascites (not actual), and 11 controls we investigated by echocardiography and echocolor Doppler left ventricle diastolic function (E wave, A wave, E/A ratio, deceleration time of E wave), systolic function (ejection fraction), and wall thickness (left ventricle posterior wall thickness + interventricular septum thickness) along with neurohumoral variables. All measurements (supine position) were repeated after total paracentesis (10.7 ± 0.6 L of ascites) in ascitic patients. Both in patients with and without ascites E/A ratio was reduced as compared with controls (0.93 ± 0.07 and 0.97 ± 0.06 vs. 1.18 ± 0.08, P < .05) while left ventricle wall thickness was increased (18.6 ± 0.6 and 20.1 ± 0.8 vs. 17.2 ± 0.7, P < .05 and P < .01, respectively), irrespective of the postviral or alcoholic cause of liver disease. In all cirrhotics both right and left atrial and right ventricle diameters were significantly greater. Ejection fraction was slightly but significantly (P < .01) reduced in ascitic patients. Paracentesis induced a reduction of the highly increased basal plasma renin activity, aldosterone, norepinephrine (P < .01), and epinephrine (P < .05) and improved diastolic function (E/A, P < .05). Systolic function was unaffected. Thus, irrespective of ascites and cause, advanced cirrhosis is associated with left ventricle diastolic dysfunction and wall thickness increase. We can speculate that neurohumoral overactivity, known to stimulate cardiac tissue growth, may challenge the heart, promoting fibrosis and exerting a further hindrance to ventricular relaxation in patients with cirrhosis experiencing episodes of ascites.
The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the ...Tevatron delivered 12fb−1 of integrated luminosity of pp¯ collisions at s=1.96TeV. The physics at CDF includes precise measurements of the masses of the top quark and W boson, measurement of CP violation and Bs mixing, and searches for Higgs bosons and new physics signatures, all of which require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2–5 years of operation, radiation doses up to 2Mrad (0.02Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDF's physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance.
•We have operated the CDF II silicon detector system well beyond its design lifetime.•We describe design of each component, its performance parameters and resource needs.•A history of operational experience and mitigation of encountered problems is given.•Novel methods were found to mitigate wirebond resonance and cooling system corrosion.•Radiation aging effects on silicon sensors from a decade long exposure are presented.
Previous studies have shown that essential hypertension and obesity are both characterized by sympathetic activation coupled with a baroreflex impairment. The present study was aimed at determining ...the effects of the concomitant presence of the 2 above-mentioned conditions on sympathetic activity as well as on baroreflex cardiovascular control. In 14 normotensive lean subjects (aged 33.5±2.2 years, body mass index 22.8±0.7 kg/m mean±SEM), 16 normotensive obese subjects (body mass index 37.2±1.3 kg/m), 13 lean hypertensive subjects (body mass index 24.0±0.8 kg/m), and 16 obese hypertensive subjects (body mass index 37.5±1.3 kg/m), all age-matched, we measured beat-to-beat arterial blood pressure (by Finapres device), heart rate (HR, by ECG), and postganglionic muscle sympathetic nerve activity (MSNA, by microneurography) at rest and during baroreceptor stimulation and deactivation induced by stepwise intravenous infusions of phenylephrine and nitroprusside, respectively. Blood pressure values were higher in lean hypertensive and obese hypertensive subjects than in normotensive lean and obese subjects. MSNA was significantly (P <0.01) greater in obese normotensive subjects (49.1±3.0 bursts per 100 heart beats) and in lean hypertensive subjects (44.5±3.3 bursts per 100 heart beats) than in lean normotensive control subjects (32.2±2.5 bursts per 100 heart beats); a further increase was detectable in individuals with the concomitant presence of obesity and hypertension (62.1±3.4 bursts per 100 heart beats). Furthermore, whereas in lean hypertensive subjects, only baroreflex control of HR was impaired, in obese normotensive subjects, both HR and MSNA baroreflex changes were attenuated, with a further attenuation being observed in obese hypertensive patients. Thus, the association between obesity and hypertension triggers a sympathetic activation and an impairment in baroreflex cardiovascular control that are greater in magnitude than those found in either of the above-mentioned abnormal conditions alone.
The high luminosity upgrade of the Large Hadron Collider (HL-LHC) at CERN is expected to provide instantaneous luminosities of 5 × 1034cm−2s−1. The high luminosities expected at the HL-LHC will be ...accompanied by a factor of 5 to 10 more pileup compared with LHC conditions in 2015, causing general confusion for particle identification and event reconstruction. Precision timing allows to extend calorimetric measurements into such a high density environment by subtracting the energy deposits from pileup interactions. Calorimeters employing silicon as the active component have recently become a popular choice for the HL- LHC and future collider experiments which face very high radiation environments. We present studies of basic calorimetric and precision timing measurements using a prototype composed of tungsten absorber and silicon sensor as the active medium. We show that for the bulk of electromagnetic showers induced by electrons in the range of 20 GeV to 30 GeV, we can achieve time resolutions better than 25 ps per single pad sensor.
About a case of micropenis Bolla, G.; Mammi, I.
La Pediatria medica e chirurgica,
07/2013, Letnik:
35, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The early hormonotherapy of micropenis takes on a diagnostic significance too. The very good tolerance gives value to this behaviour. The Author shows the condition of a male infant 46,XY eighteen ...months old; the child appeared with a micropenis completely expressed and resulting from hypogonadotropic hypogonadism. He confirms the good response to hormonotherapy for this child.
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