Characterization of upper arm synergies during reaching tasks in able-bodied and hemiparetic subjects.

BACKGROUND: In the past, several studies showed the existence of a synergistic behavior between elbow and shoulder joints during reaching movements in able-bodied subjects. The aim of this paper was to characterize the modifications of upper arm synergies during reaching induced by stroke. METHODS: Ten able-bodied right-handed subjects, eight right-handed subjects with hemiparesis affecting the right (dominant) upper limb participated in the experiments. The kinematics of shoulder and elbow joints have been recorded in all the participants during selected reaching movements. From the eight-like plots characterizing the relationship between shoulder and elbow angular velocities, a topological parameter (named as C approximately ) representing the linear approximation of the synergy between the two angular velocities has been extracted. FINDINGS: The results of these experiments showed that C approximately could be used as a figure of merit for the comparison of performance in able-bodied and hemiparetic persons. The hemiparetic subjects showed a significantly higher spreading of the values of C approximately for the different reaching movements when compared with the performance of able-bodied subjects. INTERPRETATION: This work showed that hemiparesis modified upper arm synergies and could provide a protocol for the assessment of upper limb function. Moreover, important applications of this method could be found in the development of biomimetic algorithms for the control of upper extremities during reaching in humanoid robots, and in the design of customized "games" in neurorehabilitation procedures implemented by using robotic and mechatronic platforms.

Osmotic fragility of erythrocytes, cell deformability and secondary hyperparathyroidism in uremic patients on maintenance hemodialysis.

The possible relationship between erythrocyte (RBC) function and secondary hyperparathyroidism (HPT) was examined in 35 uremic patients on maintenance hemodialysis. Mechanical tests (i.e., osmotic fragility and deformability) were used to assess RBC function. Secondary HPT was evaluated by means of serum biochemistry (parathyroid hormone, calcium, phosphorus, and alkaline phosphatase) and radiographic examinations (X-ray films of the hand skeleton). Sixteen sex and age-matched normal volunteers acted as controls. This study shows that the mechanical properties of RBC were indeed markedly altered in hemodialysis patients when compared with controls. No significant correlations between either the osmotic fragility or the deformability of RBC and the hematochemical changes associated with secondary HPT were found. No differences in RBC function tests were found as far as the activity (alkaline phosphatase) or the severity (X-ray findings) of secondary HPT are concerned. Effective treatment of secondary HPT by either pharmacological means (1,25-dihydroxycholecalciferol) or surgical removal was not associated with consequent improvement in RBC function. These findings clearly speak against secondary HPT as a major cause of RBC dysfunction in uremic patients on maintenance hemodialysis.

Hemodialysis-associated platelet loss: study of the relative contribution of dialyzer membrane composition and geometry.

To evaluate the relative contribution that dialyzer membrane composition and geometry make to hemodialysis-associated platelet loss, the effect of a single dialysis with three different types of dialyzers on platelet count was examined on a cross-over basis in 19 uremic patients on maintenance hemodialysis. Also, the plasma levels of antithrombin-iii before and after dialysis were measured, but no significant variations were found regardless of which dialyzer was in use. Our patients suffered significant platelet loss during cuprophan dialysis, but not polyacrylonitrile dialysis. More than 99% of initial circulating platelets were recovered at the end of polyacrylonitrile dialysis, whereas cuprophan dialysis did leave a significantly lower percentage of circulating platelets (p less than 0.05). The internal comparison of results obtained with the two cuprophan dialyzers used shows no difference as to the dialyzer geometry (flat plate or hollow fiber). This indicates that the membrane composition is the major factor influencing hemodialysis-associated platelet loss. We suggest that patients with low platelet count and/or with risk of bleeding may benefit from polyacrylonitrile dialysis.

[The alpha-1-acid glycoprotein (alpha-1-ag) in serum of uremic patients in maintenance hemodialysis]. / L'alfa-1-glicoproteina acida (alfa-1-GA) nel siero dei pazienti uremici in emodialisi periodica.

To evaluate the role, if any, of alpha-1-ag in the pathogenesis of dislipidemia in hemodialysis patients, serum alpha-1-ag levels were measured in 31 patients during maintenance hemodialysis. The mean serum alpha-1-ag concentration was higher in the dialysis patients (117.58 +/- 36.65) than in controls (98.32 +/- 19.5) (p greater than 0.05), with an unexplained significant difference between males and females (p less than 0.01). Serum alpha-1-ag levels were above normal in 6 patients (19.3%) and below normal in no one. A further significant increase in the mean alpha-1-ag concentration was observed following a single dialysis (132.19 +/- 37.12) (p less than 0.001). No correlation with dialytic age or underlying nephropathy was noted. Serum alpha-1-ag levels did not correlate with serum triglycerides, nor was there any difference between normotriglyceridemic and hypertriglyceridemic patients. Therefore it seems unlikely that a deficit in alpha-1-ag due to uremia per se or secondary to dialysis may have a role in pathogenesis of dislipidemia in uremic patients during maintenance hemodyalysis.

[Serum ferritin and iron therapy in patients treated with periodic hemodialysis]. / Ferritina sierica (SF) e terapia marziale nei pazienti in emodialisi periodica.

Serum ferritin, measured by radioimmunoassay in 65 dialysis patients (mean time of dialysis 38.9 months), was significantly higher (247.9 +/- 224.5 ng/ml) than in controls (p less than 0.001), inversely correlated with dialytic age (p less than 0.05), and had no difference as far as sex or underlying nephropathy were concerned. With regard to the other hematological parameters, serum ferritin correlated inversely with total transferrin and directly with percentage of total transferrin only. In 28 patients, an intravenous iron load (0.6 g in one month) induced a further increase in serum ferritin (p less than 0.001), rather disomogenous and not clearly correlated with initial levels. The change in hemoglobin concentration after iron administration was in close relationship with initial serum ferritin levels (r = -0,72, p less than 0.001). A significant increase in hemoglobin could be detected in all the patients with serum ferritin less than 65 ng/ml and in most patients with serum ferritin less than 160 ng/ml, while hemoglobin change was negligible when serum ferritin levels in dialysis exceeded this value. Thus, although serum ferritin levels in dialysis patients may reflect not only iron overload but also an abnormal metabolism, serum ferritin measurement remains a reliable guide to iron requirement. We suggest maintaining serum ferritin levels between 65 and 160 ng/ml, to avoid iron stores depletion and on the contrary, iron overload.

[Hbeag/Anti-hbe system and other markers for hepatitis b in a dialysis unit (author's transl)]. / Sistema HBeAg/anti-HBe ed altri markers: situazione in un centro di emodialisi.

The Authors study with radioimmunoassay for detection of HBeAg, anti-HBc, anti-HBs, anti-HBe, 22 patients on regular dialysis treatment, 41 their familiars, 10 staff dialysis unit members and 16 their familiars. There was found sure correlation between in the mean type presence of HBsAG and HBeAg and risk of infectious hepatitis B. The presence of the "e" antibody has not always protective significance and was stressed the importance of non parenteral virus transmission.

[Protein, immunological and "Gc", "Gm" and "Inv" picture in high-risk mastectomized subjects]. / Quadro proteico, immunologico e fattori "Gc" "Gm" ed "Inv" in soggetti mastectomizzati e ad alto rischio.

In the field of research on cancer we studied 294 women of which 142 who had undergone mastectomy, 70 selected for a high risk group, 82 normal. In order to determine some parameters who characterize the three groups we research for each the globulin factor Gc, Gm, and Inv, the proteic fractions and the immunoglobulins, as already pointed out by other investigators. The study of data points out results some times not according to previous reports. Comparing people who had undergone mastectomy and who had been selected for a high risk group, on the bases of GC phenotype together with immunoglobulins we obtained interesting values that characterize and delimit the two groups.

[Observations on the behaviour of anti-HAV antibodies (author's transl)]. / Osservazioni sul comportamento degli anticorpi anti-HAV.

The behaviour of anti-HAV antibodies was studied in the following conditions: a) a sample group of 2645 subjects from a healthy population; b) a group of 32 subjects with previous HB-Ag negative viral hepatitis; c) 12 cases of acute virus A hepatitis; d) a group of 18 anti-HAV positive women at the end of their pregnancies the antibodies were thus also studied in the funicular blood and in the newborn babies. The results showed: a) high reactivity (78%) of the healthy population to anti-HAV's; b) the possibility of an a posteriori diagnosis of virus A hepatitis in the presence of serology, negative for B type hepatitis, and positive for the anti-HAV's but with a titre higher than 1:200; c) the possibility of a serological diagnosis of acute virus A hepatitis in the presence of serology, negative for B type hepatitis and positive for the anti-HAV's with high and progressively increasing titre; d) the possibility of anti-HAV antibodies passing from mother to foetus, and the rapid elimination of the antibodies by the newborn baby within a month of his birth.

[Ulterior acquisitions regarding the salmonellosis (author's transl)]. / Ulteriori acquisizioni in tema di salmonellosi.

The Authors report the results of the bacteriological researches on the incidence of the Salmonella of our zone, after a brief consideration of general aspects salmonellosis. Our observations are refered to 1005 samples of feces of which 84 cases proved positive to Salmonella. It is pointed out that morbidity, represented by Salmonella typhi, paratyphi A and B is low, while it is high for the Salmonella typhimurium and Salmonella enteritidis. The Authors conclude stating that epidemiological situation of salmonellosis still represents a problem of remarkable importance which demands the intensification and the use of efficacious measures of prophylaxis.

[Utilisation of Olivetti P 652 calculator system for RIA evaluation (author's transl)]. / Utilizzazione del sistema di calcolo Olivetti P 652 per la gestione dati in RIA.

The AA. take into consideration the utilisation of the Olivetti calculator system including the following hardware: P 652 basic unit microcomputer; paper tape reader LN 20; Editor 4 ST typewriter, for RIA evaluation. For this purpose they have compiled a series of generalized programmes that utilise for the calculation of the standard curve, the logit transform fitted by using a linear regression or a cubic regression and the sigmoidal linear logarithmic curve calculated by cubic regression. Other two programmes are described also for automatic data reduction in the detection of hepatitis associated antibody (anti-Australia antigen) and of normalized serum thyroxine.