Natural Killer cells responsiveness to physical esercise: a brief review

Natural killer cells (NK) are a group of peripheral blood lymphocytes which display cytotoxic ac- tivity against a wide range of tumour cells. They are a consistent part of the inflammatory re- sponse that is activated when either internal or external injuries occur as they are able to syn- thesize perforins. An important role is played by NK cells in the host defence against tumours without expressing any antigen-binding recap- tor in their membrane which, however, distin- guish T and B lymphocytes. NK activity appears early in the immune response, thus providing immediate protection during the time required for the activation and proliferation of cytotoxic T lymphocytes and for their differentiation into functional cells. Even though much research regarding the effects of aerobic training exercise on NK cell numbers and function, there appears to be much controversy regarding its effect. NK cells are rapidly mobilized into circulation in response to acute exercise, most likely by in- creased shear stress and catecholamine-in- duced down-regulation of adhesion molecule expression. However, tissue injury and inflam- mation which often accompanies strenuous ex- ercise have been associated to post-exercise NK cell suppression. Scientific evidence indicates exercise-induced changes in NK cell redistribu- tion and function should be strongly influenced by stress hormones including catecholamines, cortisol and prolactin as well as by soluble me- diators such as cytokines and prostaglandins. The role of exercise therapy in cancer patients and survivors rehabilitation is becoming increasingly important as it is thought to modulate immunity and inflammation. However, more knowledge about the effects of exercise on im-mune function in these patients is needed

Variazioni stagionali del potenziale idrico fogliare, osmotico e di pressione nel grano duro

In 1982 the seasonal changes of leaf Ψ, Ψs and Ψpof five durum wheat cultivars grown under field conditions was monitored using a psycrometric apparatus. There was found to be a general increase in pressure during the floreal differentiation-earing period. No particular differences were observed either between the tall and dwarf varieties or between those with bloom or not. The relation between the values ot Ψp and leaf Ψ, taken from the earing period to the inltial stage of leaf senescence das not fallow a linear regression in all the varieties. According to an analysis of the differing values of Ψ p and Ψ, it seems that the varieties «Tibula» and «Creso» are more resistant to water stress than the other varieties, although these findings require further convalidation

Risposta produttiva del mais e del sorgo agli stress idrici indotti in diverse fasi del ciclo biologico

During 1982 a comparative test was conducted between a maize hybrid and a sorghum hybrid of similar growing cycle duration, to study the effect of water stress induced during various phases of the biological cycle. Yield response and the analysis of physiological parameters confirm the higher resistence of sorghum to water stress presumably through mechanisms of osmotic adjustment. Nel corso del 1982 è stata attuata una prova di confronto tra un ibrido di mais e di sorgo di simile durata del ciclo colturale al fine di studiare gli effetti dello stress idrico indotto in diverse fasi del ciclo biologico. I risultati produttivi e l'analisi dei parametri fisiologici presi in considerazione confermano la superiore capacità del sorgo ad "adattarsi" a condizioni di limitata disponibilità idrica del terreno, presumibilmente attraverso meccanismi di aggiustamento osmotico. Nel mais da granella i decrementi di produzione sono risultati simili sospendendo temporaneamente le erogazioni idriche o durante la fase di levata o di maturazione lattea. Si rileva, infine, che con ottimali disponibilità idriche, il mais ha confermato la sua superiorità produttiva nei confronti del sorgo

Effetti della densità di semina e della concimazione azotata sulla produzione del triticale

In the year 1981-82 a factorial trial of nitrogen fertilization (80, 120, 160, kg ha-1of N) and sowing rates (300, 350, 400 viable seeds per m2) has been carried out on three triticale lines in two environments of Sardinia (Oristano and Sassari). Equal N rates have been applied to a durum wheat at 350 sowing rate. The limited water availability in the soil, especially during the grain filling, has negatively affected the DM accumulation processes more markedly in the high ear n. per m2 thesis. In both sites the n. of plants increased with increase in seed rates and there was a greater correspondence between theoretical and reaI density at Oristano. Indipendently of the varieties and N rates, at Sassari yields have been slightly increasing with increase in sowing rates to which variations in the ear n. per m2 correspond in the same way, while at Oristano significant production increase has been achieved only by N80 rate owing to the seed rate. At Sassari, indipendent of sowing rates, triticale grain yields have been slightly increasing with increase in N rates. At Oristano production variation has not been achieved with lower sowing rates, decrease has been observed with more then N 80 kg ha-1 at higher sowing rate. A slightly higher triticale grain production compared with durum wheat has been achieved restricted to Oristano

Determinazione del «crop-water-stress-index» mediante l'uso del termometro a raggi infrarossi: nota I

The use of the infrared thermometer to determine water status of a soyabean crop as been tried in 1986. The methodology followed was that of Idso. Results show that crop-water-stress-index (C.w.S.I.) is right far the purpose of evaluating the extent of water stress and its mean value, during the reproductive stage, is significatively related to seed yield

Possibilità produttive di erbai e cereali autunno-vernini in ambienti marginali dell'alta collina sarda

Over the 3 years from 1975 to 1979, yielding capacity of some annual forage crops and winter cereals was tested on marginal lands of the Sardinian hills. Triticale achieved the best results among these cereals both in direct winter use and doughy stage maturation harvesting. The vetch and oats association ensures the best spring production. An association of ray grass andcrimson clover seems interesting because of these plants facility in self seeding

Possibilità produttive dei prati monofiti di graminacee in ambiente mediterraneo

Over the four years from 1973 to 1977 the productive capacity of 20 grasses was tested on calcareous soils of northern Sardinia. The tall fescue «Maris Djebel» and «Manade» were the most productive achiving 46 and 44 t/ha of DM over the quadriennium, about half of which in autunn-winter period. The cocks-foot «Floreal» achieved good results especially with regard to the best hay production. The perennial ryegrass and Toowoomba canarygrass which had been decimated at the beginning of the third year showed poor adaptability. The Swiss ryegrass « Manava» gave good results in the first biennium (24 t/ha of DM) but later the yield was reduced because of difficulty in self-seeding

Improvement in Hemodynamic Responses to Metaboreflex Activation after One Year of Training in Spinal Cord Injured Humans

Spinal cord injured (SCI) individuals show an altered hemodynamic response to metaboreflex activation due to a reduced capacity to vasoconstrict the venous and arterial vessels below the level of the lesion. Exercise training was found to enhance circulating catecholamines and to improve cardiac preload and venous tone in response to exercise in SCI subjects. Therefore, training would result in enhanced diastolic function and capacity to vasoconstrict circulation. The aim of this study was to test the hypothesis that one year of training improves hemodynamic response to metaboreflex activation in these subjects. Nine SCI individuals were enrolled and underwent a metaboreflex activation test at the beginning of the study (T0) and after one year of training (T1). Hemodynamics were assessed by impedance cardiography and echocardiography at both T0 and T1. Results show that there was an increment in cardiac output response due to metaboreflex activity at T1 as compared to T0 (545.4 ± 683.9 mL · min(-1) versus 220.5 ± 745.4 mL · min(-1), P < 0.05). Moreover, ventricular filling rate response was higher at T1 than at T0. Similarly, end-diastolic volume response was increased after training. We concluded that a period of training can successfully improve hemodynamic response to muscle metaboreflex activation in SCI subjects

Role of heart rate and stroke volume during muscle metaboreflex-induced cardiac output increase: differences between activation during and after exercise

We hypothesized that the role of stroke volume (SV) in the metaboreflex-induced cardiac output (CO) increase was blunted when the metaboreflex was stimulated by exercise muscle ischemia (EMI) compared with post-exercise muscle ischemia (PEMI), because during EMI heart rate (HR) increases and limits diastolic filling. Twelve healthy volunteers were recruited and their hemodynamic responses to the metaboreflex evoked by EMI, PEMI, and by a control dynamic exercise were assessed. The main finding was that the blood pressure increment was very similar in the EMI and PEMI settings. In both conditions the main mechanism used to raise blood pressure was a CO elevation. However, during the EMI test CO was increased as a result of HR elevation whereas during the PEMI test CO was increased as a result of an increase in SV. These results were explainable on the basis of the different HR behavior between the two settings, which in turn led to different diastolic time and myocardial performance