A 15 week randomised double blind placebo controlled trial of oral potassium supplements (48 mmol daily) was conducted in 37 patients who had mildly increased blood pressure and a normal dietary intake of sodium. After a two month run in and a one week baseline period the patients were randomly assigned to receive either potassium supplements (n = 18) or placebo (n = 19). By the third week of treatment blood pressure in the actively treated group had decreased significantly compared with that in the placebo group, though the decrease reached its maximum after 15 weeks. Urinary potassium excretion increased significantly in the group who received potassium supplements, but no significant changes were found in plasma sodium and potassium concentrations or in urinary sodium excretion. In a subgroup of 13 patients who underwent a further nine weeks of treatment with oral potassium supplements at half of the previous dose (24 mmol daily) their blood pressure, at the end of this second study period, was still significantly lower compared with their baseline value but not with that of the placebo group. These results show that moderate oral potassium supplements are associated with a long term reduction in blood pressure in patients who have mild hypertension.
There is evidence that hypertension is frequently associated with overweight/obesity even in kids and adolescents. Either conditions influence development of left ventricular (LV) hypertrophy (LVH), through different biological and hemodynamic mechanisms: obesity is conventionally thought to elicit a coherent growth of LV chamber dimensions and myocardial wall thickness (eccentric LV geometry), whereas a more accentuated increase in wall-thickness (concentric LV geometry) is attributed to hypertension. While during youth these differences are visible, proportion of LV concentric geometry, the most harmful LV geometric pattern, sharply raises in obese individuals during middle age, and becomes the most frequent geometric patterns among obese-hypertensive individuals. Two conditions with elevated hemodynamic impact, severe obstructive sleep apnea and masked hypertension contribute to the development of such a geometric pattern, but non-hemodynamic factors, and specifically body composition, also influence prevalence of concentric LV geometry. Contrasting a general belief, it has been observed that adipose mass strongly influences LV mass, particularly in women, especially when fat-free mass is relatively deficient. Thus, though blood pressure control is mandatory for prevention and reduction of LVH in obese hypertensive patients, without reduction of visceral adiposity regression of LVH is difficult. Future researches should be addressed on (1) assessing whether LVH resulting from alteration of body composition carries the same prognosis as pressure overload LVH; (2) defining tissue characterization of the hypertrophic heart in obese-hypertensive patients; (3) evaluating whether assessment of hemodynamic loading conditions and biological markers can help defining management of the association of obesity with hypertension.
Vanilla planifolia Andrews o Vanilla fragrans e una liana erbacea della famiglia delle Orchidaceae originaria dell’America centrale. Il frutto dall’odore balsamico viene impropriamente chiamato baccello e dopo la raccolta viene sottoposto a fermentazione ed essiccazione ottenendo dei bastoncini bruni, flessibili, che si ricoprono di una patina bianca costituita da microcristalli di vanillina. L’origine geografica influenza le proprieta fisiche, le caratteristiche organolettiche e la composizione chimica dei frutti di vaniglia: i maggiori produttori sono il Madagascar, le isole Comore e Reunion, Indonesia, Messico, Indie Occidentali e Sud America. Lo scopo del lavoro e quello di trovare le migliori condizioni estrattive per le capsule di vaniglia impiegando come solventi di estrazione etere etilico, alcol metilico e diclorometano e sottoponendo a diverse tecniche di analisi gli estratti ottenuti per l’analisi quali-quantitativa delle sostanze estratte. I componenti principali che caratterizzano l’aroma della vaniglia sono: acido p-idrossibenzoico, p-idrossibenzaldeide, vanillina e acido vanillico. Le quantita relative di questi componenti principali rispetto alla vanillina nell’ estratto naturale e ben definito e, oltre ad essere un indice della buona qualita, permette di identificare la provenienza della pianta e scoprire le eventuali adulterazioni. Vanilla planifolia Andr.: a natural flavouring used in foodstuff, pharmaceuticals and cosmetics Summary Vanilla planifolia Andrews or Vanilla fragrans is a herbaceous liana of the Orchidaceae family and it is a plant native to Central America. The fruit, improperly called ”pod”, is characterized by a peculiar balsamic smell. After the collection fruits undergo fermentation and drying to obtain the tawny, flexible rods comes, that cover with a white vanillin microcrystals layer. Geographic origin influences the physical properties, the organolectic characteristics, and the chemical composition of Vanilla fruits. Major producers are the Madagascar, the Western Comore Islands, Reunion, Indonesia, Mexico, West Indies and South America. The scope of the present study is the analysis of ethyl ether, methyl alcohol and dichlorometane extracts of commercially available Vanilla caps using different analytical methods. The main compounds identified that characterize Vanilla aroma are p-idrossibenzoic acid, the p-idrossibenzaldeide, vanillin, and vanillic acid. The ratio of these main compounds compared to vanillin in natural extracts is well defined and can be useful as quality indicator. Moreover, it can help in locating the geographical origin of the plant and to identify possible extracts counterfeits.
The spinal volleys evoked by single transcranial magnetic or electric stimulation over the cerebral motor cortex were recorded from a bipolar electrode inserted into the cervical epidural space of three conscious human subjects. These volleys were termed direct (D) and indirect (I) waves according to their latency. We measured the size and number of volleys elicited by magnetic stimulation at various intensities with subjects at rest and during 20 or 100 % maximum contraction of the contralateral first dorsal interosseous muscle (FDI). Surface EMG activity was also recorded. Electrical stimulation evoked a D‐wave volley. Magnetic stimulation at intensities up to about 15 % of stimulator output above threshold evoked only I‐waves. At higher intensities, a D‐wave could be seen in two of the three subjects. At all intensities tested, voluntary contraction increased the number and size of the I‐waves, particularly during maximum contractions. However, there was only a small effect on the threshold for evoking descending activity. Voluntary contraction produced large changes in the size of EMG responses recorded from FDI. Because the recorded epidural activity is destined for muscles other than the FDI, it is impossible to say to what extent increased activity contributes to voluntary facilitation of EMG responses. Indeed, our results suggest that the main factor responsible for enhancing EMG responses in the transition from rest to activity is likely to be increased excitability of spinal motoneurones, rather than increases in the corticospinal volley. The latter may be more important in producing EMG facilitation at different levels of voluntary contraction.
Cardiovascular responses to sympathetic stimulation may be altered in the early phases of life of subjects with a family history of hypertension. The possible influence of physical activity on adrenergic modulation in children is still not well known. In this study we evaluated, in a group of 162 11-year-old children from a secondary school near Naples, blood pressure and heart rate measured 4 times at 3-week intervals at rest and during adrenergic system stimulation by mental arithmetic stress and isometric exercise. Children were divided into sedentary and physically active groups according to the levels of a Saltin modified questionnaire. Family history of hypertension was also investigated. Systolic and diastolic blood pressure at rest were slightly higher in the sedentary group at each control (107/75±11/11 vs 105/73±11/11mmHg at the first and 100/70±14/14 vs 98/69±9/9 at the last control); heart rate in the same group was higher as well (91±11 vs 87±12 beats/min, p<0.02 at the first and 80±9 vs 77±11 at the last control).Systolic and diastolic blood pressure increased by 7/15% during mental stress and by 23/45% during isometric exercise in the sedentary group. The corresponding blood pressure increases in the physically active group were 6/12% and 20/40%, respectively. These responses were independent of sex, body weight and family history of hypertension. These results support the hypothesis that regular physical activity in young adolescents only mildly influences resting blood pressure and cardiovascular responses during the stimulation of the sympathetic nervous system.
