Studies on homocysteine plasma levels in Alzheimer's patients. Relevance for neurodegeneration.

Homocysteine (HC) may work inter alia as a Volume Transmission signal since HC is present in the brain and cerebrospinal fluid and binds to NMDA receptors. Furthermore, in cell cultures increased HC formation increases its export. In the present study we have shown that after intravenous injection in intact animals HC penetrates the blood-brain barrier. Hence, it works as a blood-born humoral signal. Furthermore, we have studied HC plasma levels in a group of Alzheimer's (AD) patients and compared with a group of age-matched patients. It has been confirmed that a positive correlation exists between age and HC plasma levels in the control group, but not in the AD patients. These results may depend on the fact that in AD patients high HC plasma levels (possibly associated with high glycine levels and/or excessive glutamate release) have favored neurodegeneration and, once this pathological process has been triggered off, the plasma HC levels become independent of the "physiological" aging-induced increase of HC plasma levels.

Studies on homocysteine and dehydroepiandrosterone sulphate plasma levels in Alzheimer's disease patients and in Parkinson's disease patients.

Homocysteine (HC) and dehydroepiandrosterone sulphate (DHEAS) plasma levels have been evaluated in groups of male and female patients with Parkinson's disease (PD) and in a group of female patients with Alzheimer's disease (AD) and compared with the corresponding plasma levels observed in a group of age-matched subjects. It has been confirmed that HC plasma levels are enhanced in both PD and AD patients. As far as the DHEAS plasma levels are concerned no changes have been observed in PD patients while a marked decrease has been observed in AD patients. These results support the view that while the pro-oxidant effects of HC and its agonist action at NMDA receptors can play a role in both neurodegenerative diseases, the role of DHEAS is more complex and may be an important factor only in certain neurodegenerative diseases. Thus, according to the present study DHEAS is likely to be involved in AD but not in PD.

[In vitro study of periodontal ligament cells]. / Studio in vitro delle cellule del legamento periodontale.

BACKGROUND: The aim of this research is to outline a procedure able to promote specific cellular differentiation and proliferation with consequent periodontal regeneration. To achieve this goal, use was made of various compounds supposed to have the capacity of aiding periodontal regeneration. METHODS: The cells utilised for this study were obtained from explants of human periodontal ligaments. Their proliferation and differentiation capacity was examined in the presence of: coral granules (350, 500 mu), collagene type 1, growth factors (Platelet derived growth factor, PDGF and Transforming growth factor beta 1, TGF beta 1), both on their own and in different combination with one another. The differentiation activity was evaluated by ultrastructural morphological method (Transmission electron microscope-TEM) and by spectrophotometric investigation of the alkaline phosphatasis (ALP). RESULTS: The data show that the coral granules and among the growth factors used only TGF beta 1 stimulate the differentiation activity of the periodontal ligament cells valued on the basis of their capacity of producing ALP. These data are supported by the observation with TEM. CONCLUSIONS: From these results it is suggested that there may be therapeutic efficiency in the periodontal field of substances promoting cellular proliferation and differentiation.

Compartment syndrome of the scapula. Definition on clinical, neurophysiological and magnetic resonance data.

Compartment syndromes of the scapula and pelvic girdle have received scant attention in the literature. In 1938, Comolli first described a clinical sign which he considered specific to fracture of the scapula. We report data on two patients, one presenting with prolonged pressure on the posterior surface of the scapula and the other with symptoms associated with scapular fracture. In one of these patients we were able to measure pressures around the scapula, perform neurophysiological assessment of nerve function and produce magnetic resonance images of the area. In the other case, surgical exploration revealed an established ischaemic contracture of the infraspinatus muscle within its compartment. These findings suggest that the muscles around the scapula are vulnerable to the development of compartment syndrome.