Cardiovascular consequences of primary antihypertensive therapy with prazosin hydrochloride

Ten patients with essential hypertension who had no end-organ damage were treated with prazosin, starting with a dose of 1 mg/day. The dose was titrated to a maximal tolerated dose not exceeding 20 mg/day in divided doses or until diastolic blood pressure decreased to 90 mm Hg or lower. Among this study population a statistically significant decrease in blood pressures was achieved in the supine, sitting and standing positions. Baseline studies were repeated after 8 weeks of continuous therapy. There was no significant change in peripheral plasma renin activity, serum aldosterone or urinary sodium excretion. Plasma volume increased significantly and the patient weight increased proportionately. Cardiac ejection fraction at rest did not change significantly after prazosin therapy. Exercise ejection fraction also was not changed significantly from baseline during therapy, and the exercise-induced increase in blood pressure was significantly blunted. No adverse effects of prazosin on cardiac function were detected in this short-term study.     

Analysis of the ST-segment in terms of principal components: application on multichannel magnetocardiographic recordings

Parameterization of the ST-segment is used as a tool for risk stratification for patients to suffer from ventricular tachycardia. This parameterization is performed in terms of Principal Component Analysis (PCA) applied on multichannel magnetocardiographic (MCG) recordings. 55-channel MCG was recorded from 14 normal persons, 10 patients with CHD, 14 patients with MI, and six patients with VT. We found a significantly (p?<?0.05) lower PCA-score in patients with MI compared to normals. The lowest PCA-score was found in VT patients. Significant differences can be found between VT patients and normals and also between VT patients and CHD patients.     

A new method of measuring the stiffness of corpus cavernosum penis with ShearWave? Elastography

Objective:

To evaluate the feasibility of measuring the stiffness of corpus cavernosum penis (CCP) with ShearWave™ Elastography (SWE; SuperSonic Imagine, Aix-en-Provence, France).

Methods:

40 healthy volunteers with ages ranging from 19 to 81 years (mean, 36 years; standard deviation, 17 years) were selected in this study. The ultrafast ultrasound device Aixplorer^® (SuperSonic Imagine) was used for the research and the probe selected was SuperLinear™ SL15-4 (SuperSonic Imagine). The shear wave stiffness (SWS) of CCP was measured using SWE images. The measurement indexes of SWS included (1) SWS of CCP measured in the transverse section (SWS-T), (2) SWS of CCP measured in the longitudinal section (SWS-L) and (3) mean of SWS-T and SWS-L (SWS-M). The interval between hormone test and SWE examination of each subject was less than 7 days. The paired t-test was used to analyse the differences between SWS-T and SWS-L. The Pearson correlation was used to analyse the correlation of SWS of CCP with age as well as with sex hormone levels.

Results:

There was no significant difference between SWS-T and SWS-L (p > 0.05). SWS (SWS-T, SWS-L, SWS-M) was negatively correlated with age and oestradiol value, and SWS (SWS-T, SWS-L, SWS-M) was positively correlated with testosterone value.

Conclusion:

SWE could serve as a new non-invasive method of evaluating the stiffness of CCP.

Advances in knowledge:

It is the first time that we have discussed the feasibility of measuring the stiffness of CCP with SWE and analysed the correlation of SWS of CCP with age as well as with sex hormone levels.ShearWave™ Elastography (SWE; SuperSonic Imagine, Aix-en-Provence, France) is a new ultrasound technology that could be used to assess tissue stiffness in clinic and is currently the only elastography technology certified by the US Food and Drug Administration. This technology makes it possible to quantify the tissue stiffness accurately. Unlike early elastography methods, which rely on manual compression and measuring tissue displacement, SWE requires no manual compression, and it uses ultrasonic pulse to make the tissue generate shear waves. A real-time SWE map is produced by detection of shear wave velocity and colour coding. Since the propagation speed of the shear wave is determined by the stiffness of tissue, the real-time SWE map could be used to measure the overall and local stiffness of tissue exactly. Studies have shown that this technology could be used to evaluate the stiffness of intravital tissue accurately.^1–3Furthermore, SWE is a safe, non-ionizing and non-invasive technique that has the same thermal and mechanical energy as conventional Doppler imaging. It is applicable to the examination of human reproductive organs. The tissue structure of corpus cavernosum penis (CCP) has important impact on the stiffness of CCP. Therefore, the stiffness of CCP could be used as an index for assessing the tissue structure of CCP. At the same time, the tissue structure of CCP has important impact on the erectile function. So, it is of great clinical significance to measure the stiffness of CCP.The stiffness of CCP is closely associated with age.⁴ Previous pathological studies have indicated that, with increase in age, sinusoids in CCP gradually decrease, occlusion and fibrosis occur, the smooth muscle cells also atrophy and decrease gradually. These changes in tissue structure and composition of CCP can directly lead to the change of its stiffness. The stiffness of CCP is also associated with sex hormone levels. Testosterone can promote the generation of smooth muscle cells and enhance cell vitality in CCP. Cell vitality and generation of smooth muscle cells in CCP decline with testosterone decrease, which can lead to cell atrophy and reduction in their number and consequently a change of stiffness of CCP.^5–7However, at present, no accurate and non-invasive method can be used to assess stiffness of CCP in clinic. In this study, we evaluated the feasibility of measuring stiffness of CCP with SWE by analysing the correlation of the stiffness value of CCP with age as well as sex hormone levels.     

Unusual late presentation of X-linked chronic granulomatous disease in an adult female with a somatic mosaic for a novel mutation in CYBB

Most patients with chronic granulomatous disease (CGD) have mutations in the X-linked CYBB gene that encodes gp91phox, a component of the phagocyte NADPH oxidase. The resulting X-linked form of CGD is usually manifested in boys. Rarely, X-CGD is encountered in female carriers with extreme expression of the mutated gene. Here, we report on a woman with a novel mutation in CYBB (CCG[90-92]-->GGT), predicting Tyr30Arg31-->stop, Val in gp91phox, who presented with clinical symptoms at the age of 66. The mutation was present in heterozygous form in genomic DNA from her leukocytes but was fully expressed in mRNA from these cells, indicating that in her leukocytes the X chromosome carrying the nonmutated CYBB allele had been inactivated. Indeed, only 0.4% to 2% of her neutrophils showed NADPH oxidase activity. This extreme skewing of her X-chromosome inactivation was not found in her cheek mucosal cells and is thus not due to a general defect in gene methylation on one X chromosome. Moreover, the CYBB mutation was not present in the DNA from her cheek cells and was barely detectable in the DNA from her memory T lymphocytes. Thus, this patient shows a somatic mosaic for the CYBB mutation, which probably originated during her lifetime in her bone marrow.     

Role of the coronary sinus in maintenance of atrial fibrillation

INTRODUCTION: Bursts of tachycardia arising in the pulmonary veins may play an important role in perpetuating atrial fibrillation (AF). However, the role of the coronary sinus (CS) in the perpetuation of AF has been unclear. The aim of this study was to determine whether the CS plays a role in perpetuation of AF. METHODS AND RESULTS: Pulmonary vein isolation was performed by segmental ostial ablation with radiofrequency energy in 22 consecutive patients with paroxysmal AF. Bipolar and unipolar electrograms recorded in the left atrium and CS were analyzed during atrial pacing from the mitral annulus and during AF. There was a mean of 2.5 +/- 0.5 electrical connections between the CS and the left atrium. The electrical connections between the left atrium and CS were ablated with a mean of 6.2 +/- 2.7 minutes of radiofrequency energy applied along the atrial side of the inferior mitral annulus. During AF, episodes of intermittent tachycardia alternated between the left atrium and the CS. Among the 22 patients, sustained AF was still inducible in 9 after pulmonary vein isolation. After electrical disconnection of the CS from the left atrium, sustained AF was inducible in only 3 of these 9 patients. CONCLUSION: The CS may be a source of rapid repetitive electrical activity during AF. The lower probability of inducible sustained AF after electrical disconnection of the CS from the left atrium suggests that the CS may play a role in perpetuating AF.     

The viability of the Parenting Representations Interview for assessing and measuring change in parents of adolescents

Parents’ representations include parents’ views of their adolescent, of their own parenting and of the parent–adolescent relationship. Two longitudinal studies of parents and their adolescent sons and daughters support the validity of scales coding mothers in the Parenting Representations Interview-Adolescence (PRI-A). The studies, conducted in Israel during the transition from home to military service, demonstrated that three dimensions derived from the PRI-A: positive representations of adolescents, negative emotionality and inadequate boundaries were associated with adolescents’ AAI variables, relatedness-autonomy behaviors with mothers, and with other indicators, such as adolescents’ wellbeing, romantic intimacy and individuation. Examining parenting representations could help practitioners pinpoint targets for intervention and evaluate the changes that families go through during psychotherapy, as well as the therapeutic process and its outcomes. The findings support the viability of the PRI for use in attachment based interventions for adolescents.     

Long-term perspective on wildfires in the western USA

Understanding the causes and consequences of wildfires in forests of the western United States requires integrated information about fire, climate changes, and human activity on multiple temporal scales. We use sedimentary charcoal accumulation rates to construct long-term variations in fire during the past 3,000 y in the American West and compare this record to independent fire-history data from historical records and fire scars. There has been a slight decline in burning over the past 3,000 y, with the lowest levels attained during the 20th century and during the Little Ice Age (LIA, ca. 1400–1700 CE [Common Era]). Prominent peaks in forest fires occurred during the Medieval Climate Anomaly (ca. 950–1250 CE) and during the 1800s. Analysis of climate reconstructions beginning from 500 CE and population data show that temperature and drought predict changes in biomass burning up to the late 1800s CE. Since the late 1800s , human activities and the ecological effects of recent high fire activity caused a large, abrupt decline in burning similar to the LIA fire decline. Consequently, there is now a forest “fire deficit” in the western United States attributable to the combined effects of human activities, ecological, and climate changes. Large fires in the late 20th and 21st century fires have begun to address the fire deficit, but it is continuing to grow.Forest fires in the western United States have been increasing in size (1) and possibly severity (2) for several decades. The increase in fire has prompted multiple investigations into both the causes (3, 4) and consequences of this shift for communities, ecosystems, and climate (5). Climate changes and human activities have both contributed to the observed changes in fire, but understanding the nature and magnitude of these impacts has been challenging first because there is substantial ecological heterogeneity and variability in terms of vegetation, soils, hydrology, topography, and other factors that affect fire regimes across the western United States, and second because most fire-history data come from recent decades and centuries when climate and human activities have both undergone rapid and unique transformations. As a result, studies tend to focus either on local ecological and anthropogenic factors that drive fire at fine scales (6, 7), or on climatic influences at broad scales (3, 4). Furthermore, the limited temporal scope of many fire-history studies does not provide adequate context for examining the joint impacts of climate and human activities on broad-scale, long-term fire regime changes. In addition, projections of future climate change and its ecosystem impacts place the expected changes well outside the range of variations in the past few centuries. Thus, coupling multi-decadal-to millennial-scale data on fire, climate changes, and human activities can reveal linkages among these components that are often missed in studies restricted to finer scales or fewer factors.Here we use sedimentary charcoal accumulation rates to construct variations in levels of burning for the past 3,000 y in the western United States (i.e., the West) and compare this record to independent fire-history data from historical records and fire scars. The long charcoal records enable identification of baseline shifts in fire regimes that cannot be detected with shorter records and allow us to view the nature and extent of human impacts on fire in a long-term context; this approach helps to distill the dominant patterns in fire activity across the West, but it does not reveal the important differences in fire controls and effects among vegetation types, ecoregions, or elevation gradients that exist at finer spatial scales (e.g., ref. 8).Our focus here is specifically on multi-decadal-to-centennial-scale variations in fire over the past few millennia and on the West as a whole. Climatic variations on this time scale are characterized by extended periods of persistent anomalies, such as the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA) (9, 10), which feature broad-scale (i.e., across the whole of the western United States) anomalies of both surface climates and atmospheric circulation (10). We use temperature (10), drought (9), and population (11) data to compare with the fire-history reconstructions. We also construct a simple statistical model for predicting biomass burning from the temperature and drought data. Our analysis builds on the rich historical narratives of fire in the western United States (12) as well as on many more detailed but shorter broad-scale studies (4, 13, 14). The results illustrate the importance of climate in explaining the variations in fire over time, and show the development of a 20th century “fire deficit” related to the combined effects of fire exclusion, land-use change, and ongoing climate change.