Long-term productivity of lowland and upland switchgrass cytotypes as affected by cutting frequency.

A considerable number of studies has been conducted on switchgrass (Panicum virgatum L.) as a bioresource for energy over the last few years. Nonetheless, some important issues concerning the agro-technique are still open. This research examines the long-term total dry matter yield (TDM) and ash content of two lowland (L) and two upland (U) switchgrass cytotypes, as affected by one or two-cut system, under southern EU climatic conditions (44 degrees 33' N). Overall, L produced higher TDM than U (on average 14.9 and 11.7 Mg ha(-1), respectively); two-cut system allowed to produce higher biomass yields (especially in U) than single harvest during the two first years, but it also drastically reduced plant vigour and productivity of all cytotypes in the following two years. Moreover, under two-cut system almost total seasonal biomass derived from the early harvest, while the second cut slightly contributed to the total seasonal biomass, nor it appeared to offset the additional harvest costs. Biomass quality was also significantly affected by cutting frequency, with two-cut system leading to a considerably higher ash content of biomass. Therefore, it is perceived that two-cut system is not worthwhile with U and L cytotypes as bioresource for energy production under southern EU conditions.

Factor V Leiden mutation and patent foramen ovale in ischemic stroke.

We report a 47-years-old male with ischemic stroke, whose arteriographic and echocardiographic investigations did not reveal any steno-occlusive arterial disease or embolic source from the left cardiac chambers. A transesophageal echocardiogram showed a patent foramen ovale (PFO), whilst laboratory screening for coagulation abnormalities showed heterozygosity for factor V Leiden mutation. The significance of the association of PFO with factor V Leiden mutation is discussed as a possible cause of ischemic stroke through paradoxical embolism from a venous source. The high prevalence of these two conditions in the general population is emphasized and the indication for anticoagulant therapy is discussed.

Motor and psychomotor functions in amyotrophic lateral sclerosis evaluated by tests of motor ability.

18 patients with typical sporadic Amyotrophic Lateral Sclerosis (ALS) were investigated by the Motor Accuracy and Speed Test (MAST) and 18 healthy age- and-sex-matched volunteers, acted as controls. All performed each of the five tests 10 times with both the right and the left hands and repeated the experiment after one week by the same procedure. Motor performances were better in the controls than in the ALS patients only in the first three tasks. At retest, one week later, the controls generally improved while ALS patients did not. The mean percentages of changes showed a statistically significant difference in the fifth task. Analysis of the results suggests the possibility that, among the other mechanisms, a disturbance of motor learning ability could be operating in ALS patients.

Neuroendocrinological aspects of depression and symptomatological picture.

Cortisol and prolactin circadian rhythms were determined in a group of depressed hospitalized women who were submitted the next day to the dexamethasone suppression test. The depressed were classified as endogenous and non-endogenous according to symptomatological criteria. Some significant differences were found between the two groups when compared to control subjects in cortisol as well as prolactin biorhythms, and the cortisol suppression percentages were significantly lower in the endogenous than in the non-endogenous. This difference is abolished by benzodiazepine treatment.

Motor reactivity, pain threshold and effects of sleep deprivation in unipolar depressives.

The authors studied the motor reactivity by means of serial choice reaction, electromyography of simple reactions, and defense reflexes in normal and in depressed patients. Significant differences were observed between normal and depressed patients, especially in those with retardation. The 'retarded' depressives exhibited higher pain threshold values, a lower number of motor reactions, and more prolonged reaction times. 2 normal and 4 depressed patients were submitted to the same tests after 1 night's total sleep deprivation. In normals negative effects were found in the levels of vigilance and endurance. In depressed patients, at variance with normals, the number of motor reactions increased, the reaction time decreased, and the rate of basal motor innervation improved, tending to normalization. On the contrary, pain threshold underwent the same type of changes as in controls. Sleep deprivation seemed to specifically reduce retardation phenomena in depressives, thus strongly improving motor reactivity.

Effects of lithium salts on pain experience in depressed patients.

15 depressed female patients were studied for sensitivity to pain stimuli before and after 1 month of treatment with lithium salts. By electric stimulation techniques, an aspecific sensitivity threshold, a pain sensitivity threshold and a pain tolerance threshold were measured and their relationship were evaluated. In this investigation, we evaluated the influence of the improvement of the clinical picture and of the blood levels of the drug on pain perception. Our data seem to suggest an analgesic action of lithium, which, however, appears to be partially masked by the effects on pain perception induced by the evolution of the depressive picture.

Memory performances in depressed patients during prophylactic treatment with lithium salts.

The study involved 42 subjects suffering from unipolar depression (35 females and 7 males) who had received 600-1,200 mg of lithium carbonate daily for periods ranging from 6 months to 7 years. Concurrently with the memory tests, the patients were also submitted to the Hamilton test for the evaluation of depression and blood samples were taken in order to measure lithium blood levels. In the groups of subjects examined by us (grouped according to lithemia, time on the drug and degree of depression, as, evaluated by Hamilton's test), significant differences were found only in the short-term figure test and, partially, in the long term memory verbal test.

[Study of memory in cerebral damaged patients related to the side of lesion (author's transl]. / Studio della memoria in pazienti cerebrolesi in rapporto al lato della lesione.

Twenty-four subjects with cerebral lesions, 21 of vascular and 3 of neoplastic origin, have been tested by the Authors with a battery of tests for memory evaluation. They comprehended short term, middle term and long term memory tests. For the last ones, the subjects was requested to recall remote events presented under visual, verbal and auditory modality. For each test, results comparison between left and right hemispheric cerebral damaged patients was performed. The diagnosis of the hemispherical localisation, on the basis of clinical data established, have been confirmed by instrumental exams (EEG, CAT, Angiography). A clear difference in the results between the two groups of patients does not appear except in specific tests related to memory selective types, in which the sensitive modality of tests administration seems to be more closely in relation with the damaged hemispherical functions. Ribot's law on the longer life of old memories has not been confirmed by the long term memory tests in cerebral damaged patients.