The effect of hydroxyapatite nanocrystals on microvascular endothelial cell viability and functions

To favor bone reconstitution with biomaterials endothelial cells should maintain proper functions to drive angiogenesis. To this aim nanocrystals of hydroxyapatite (HA) have been synthesized and characterized on endothelial cells. Microvascular endothelial cells have been exposed to stoichiometric HA nanocrystals. Cell morphology and organization of cytoskeletal proteins have been monitored by SEM analysis and immunofluorescence. Biochemical markers of physiological and pathological responses of endothelial cells, endothelial constitutive nitric oxide synthase, and cycloxygenase-2 (ecNOS and COX-2, respectively) have been measured by immunofluorescence. Crystallized HA sustained endothelial survival without any cytotoxic effect. At the observation with SEM, endothelial cell morphology was maintained in the presence of HA. The localization and organization of beta-actin documented the formation of stress fibers, indicating an activation of endothelial cells induced by HA nanocrystals. Immunohistochemistry for biochemical key signaling pathways in endothelium demonstrated that nanocrystals of HA maintained the expression of ecNOS and did not increase COX-2 expression. In conclusion, the present findings indicate that HA nanocrystals exhibit high biocompatibility for microvascular endothelium. In the presence of HA nanocrystals endothelial cells maintain biochemical markers of healthy endothelium. They do not acquire a proinflammatory or thrombogenic phenotype, but express markers of functioning endothelium that might contribute to angiogenesis.     

Alkaline-treated poly(epsilon-caprolactone) films: degradation in the presence or absence of fibroblasts

In the first stage, we observed the study of the degradation behavior of alkaline-treated poly(epsilon-caprolactone) (PCL) in two biologically-related media: phosphate buffered saline (PBS) and Dulbecco's modified Eagle's medium (DMEM) for 18 months, finding a much accelerated degradation in the last one. As expected, the degradation in the presence of cells is much pronounced even considering that the study is limited to 6 months. The characterization of the degraded substrates by chemiluminescence (CL) allows to explain the modifications of the substrate and their relations with transitory oxidative stress phenomena described in the fibroblasts seeded onto the PCL membranes.     

The protective effect of L-carnitine in peripheral blood human lymphocytes exposed to oxidative agents

Literature data indicate L-carnitine (LC), a trans-mitochondrial carrier of acetyl and long chain groups, as an agent possessing protective effects against oxidative stress in mammalian cells. However, the major factor involved in the protective mechanism is not known. The protection activity exerted by this agent against reactive oxygen species induced by hydrogen peroxide (H2O2) and t-butylhydroperoxide (t-butyl-OOH) treatment in isolated human peripheral blood lymphocytes (PBLs) has been studied. Human lymphocytes cells were isolated and pre-incubated with 5 mM LC before H2O2 (100 microM) and t-butyl-OOH (400 microM) treatment. The protective effect of LC on treated PBLs was measured by single cell gel electrophoresis and the analysis of chromosomal aberrations. Results show that lc treated cells exhibited a significant decrease in the number of oxidative induced single-strand breaks and chromosomal aberrations.     

Complete weaning off immunosuppression in HCV liver transplant recipients is feasible and favourably impacts on the progression of disease recurrence

BACKGROUND/AIMS: HCV-related disease recurrence progresses rapidly after liver transplantation. We hypothesised that withdrawal of immunosuppression might favourably impact on disease progression. METHODS: Weaning off immunosuppression was attempted in 34 HCV-RNA positive patients (mean age 62+/-6.4 years) transplanted 63.5+/-20.1 months earlier, under cyclosporine A monotherapy. Patients were followed for 3 years including yearly protocol liver biopsies. Primary endpoints were feasibility of weaning off immunosuppression and its impact on disease progression. Secondary endpoint was to identify predictors of an immunosuppression-free state and fibrosis progression. RESULTS: Complete and permanent immunosuppression withdrawal was achieved in 8 patients (23.4%), whereas 14 (41.2%) developed rejection within eight months despite an initial response and 12 (35.2%) rejected during tapering. After a mean follow-up 45.5+/-5.8 months weaned patients showed stabilisation/improvement of histological fibrosis (P<0.01), lower necro-inflammation (P<0.02) and improved liver function (P<0.05) compared to weaning-intolerants. Multiple logistic regression identified low blood cyclosporine A trough levels during the first post-transplant week (P=0.004) and initial steroid-free immunosuppression (P<0.008) as independent predictors of sustained weaning. Achievement of immunosoppression freedom (P=0.02) and baseline staging score (P<0.0001) were independently associated with stabilisation/improvement of histological fibrosis. CONCLUSIONS: Reconstitution of immune-competence in the host improves the natural history of HCV recurrence in the graft.     

Absence of cerebrospinal fluid oligoclonal bands is associated with delayed disability progression in relapsing-remitting MS patients treated with interferon-beta

To determine whether combined studies of Mini-Mental State Examination (MMSE) and brain single photon emission CT (SPECT) would provide more useful means of differentiating between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD), we studied 36 patients with probable DLB and 96 patients with probable AD. DLB patients had significantly better performance on word recall, but more impaired attention and copying than AD patients. We confirmed that a weighted score derived by Ala et al. [Ala, T.A., Hughes, L.F., Kyrouac, G.A., Ghobrial, M.W., Elble, R.J. The Mini-Mental State exam may help in the differentiation of dementia with Lewy bodies and Alzheimer' disease. Int J Geriatr Psychiatry 2002;17:503–9]: (Attention − 5/3 · Memory + 5 · Construction), was helpful in discriminating between DLB and AD. SPECT study revealed that medial occipital perfusion significantly decreased in DLB patients than AD patients. Combined studies of MMSE and brain SPECT achieved a high discrimination between DLB and AD with a sensitivity of 81% and a specificity of 85%, suggesting that there is a useful and practical approach to differentiate DLB from AD. Our findings will need to be substantiated in an independent and prospective study sample.     

De novo AML patients with favourable–intermediate karyotype may benefit from the addition of low-dose gemtuzumab ozogamicin (GO) to fludarabine, Ara-C and idarubicin (FLAI): a contribution to the reopened “GO question”

We report the final results of a prospective trial testing the combination of fludarabine, Ara-C and idarubicin (FLAI) followed by low-dose gemtuzumab ozogamicin (FLAI-GO) in 85 patients aged 60 years or more with CD33+ acute myeloid leukaemia (AML). Median age was 68 years (60–82); karyotype was unfavourable in 21 patients (24 %), intermediate in 63 (74 %) and favourable in 1 (2 %). There were five therapy-related deaths. Of the 80 evaluable patients, 47 achieved complete response (CR) (58 %); CR rates were 65 and 32 % in good-intermediate/poor karyotype patients, respectively. Median length of CR was 7 months (3–76). The cumulative incidence of relapse was 84 % with an actuarial survival of 50.3 % at 1 year and 14.4 % at 2 years. The study control population is an unselected consecutive historic cohort of 104 patients treated with the FLAI regimen, who were matched for age and prognostic factors. CR rates after FLAI-GO and FLAI were comparable. However, patients with de novo AML and intermediate–favourable karyotype receiving GO had a significantly lower risk of relapse at 2 years as compared to patients not receiving GO (n?=?77) (40 vs 80 %, p?=?0.01) and significantly better disease-free survival (p?=?0.018) and overall survival (p?=?0.022).     

In Vitro Synthesis of Triglycerides and Cholesterol in Human Gallbladder Mucosa

Triglyceride and sterol synthesis was investigated in vitro in the gallbladder mucosa from control subjects and patients with acalculous cholesterolosis. The incorporation rate of ¹⁴C-acetate was 1.6 ± 0.2 nmol/g/h into cholesterol (sum of squalene, methyl sterols, and cholesterol) and 5.7 ± 0.8 nmol/g/h into triglycerides. The rates were significantly correlated with each other (r = 0.667). The conversion of ³H-mevalonate into cholesterol (49 ± 10 nmol/g/h) and triglycerides (4.7 ± 1.2 nmol/g/h) indicated a high activity in the postmevalonate cholesterol synthesis and an active shunt pathway of mevalonate metabolism. The synthesis rates of cholesterol, triglycerides, and sterol esters were closely interrelated, were unaltered in cholesterolosis, and were not correlated with the serum, biliary, and mucosal lipid concentrations. Thus, despite marked lipid accumulation the lipid synthesis proceeds effectively in the gallbladder mucosa with cholesterolosis.     

No Evidence of an Association between Helicobacter pylori Infection and Raynaud Phenomenon

Background: Raynaud phenomenon (RP) is a vasospastic condition that manifests itself as cold-induced ischemic attacks of the fingers with skin color changes. It may be classified as primary (PRP) or secondary (SRP), if associated to other diseases, mainly connective-tissue diseases. Recently, the association between PRP and Helicobacter pylori infection has been reported. The aims of this study were to evaluate the prevalence of gastric H. pylori infection in a large group of patients affected by PRP and SRP and to assess whether it was more evident in patients with more recent onset of RP. Methods: Ninety-eight consecutive patients (93 F and 5 M), referring to our videocapillaroscopic service for the diagnosis of vascular and connective-tissue diseases, were evaluated. Forty-nine of them were affected by PRP and 49 by SRP. Patients were classified as having PRP on the basis of normal serological and immunological findings, normal videocapillaroscopic examination and exclusion of other conditions inducing RP. H. pylori infection was diagnosed by ¹³C-urea breath test (UBT). Two groups of 49 age-and sex-matched controls, respectively, were also evaluated. Results: Patients with SRP resulted significantly older than those with PRP (P &lt; 0.006). UBT was found positive in 22/49 patients with PRP (45%) and in 29/49 patients with SRP (59%). The positivity of the respective control groups was 36% and 53% (P = NS). There was no higher prevalence of H. pylori infection in patients with RP lasting for less than 4 years. Conclusions: The results do not confirm the previously reported high prevalence of H. pylori infection in patients with PRP. A high association was not even found between the presence of the microorganism and SRP. There was no difference in the prevalence of H. pylori infection among the subgroups with more recent onset of both PRP and SRP.     

The effects of a soy rich diet on serum lipids: the Menfis randomized trial

OBJECTIVE: To assess beneficial effects of a soy rich diet on the main biomarkers of cardiovascular health in menopause, compared with the effects of the hormone replacement therapy (HRT). METHODS: 187 healthy asymptomatic postmenopausal women, aged 39-60, were recruited and randomized into three groups: a soy rich diet group, a HRT group, and a control group. Lipid profile, body mass index, blood pressure, endometrial thickness, uterine artery resistance index (RI), were evaluated in all the participants at the baseline, after 6 months, and at the end of the study. RESULTS: After a 6-month intervention period, the lipid profile in the soy rich diet group showed a favourable outcome, similar to that observed in the HRT group, but compliance to the diet was low. CONCLUSION: Soy products may be used in the prevention of cardiovascular risk in postmenopausal women because of their efficacy in contrasting the negative effects of menopause on the cardiovascular system, but our findings should be confirmed; moreover, suitable strategies to improve the compliance have to be considered.     

Met-enkephalin and preproenkephalin mRNA changes in the striatum of the nicotine abstinence mouse

We studied the changes of met-enkephalin (Met-Enk) content and preproenkephalin (PPE) mRNA in the striatum in a mouse model of nicotine abstinence. Nicotine, 2 mg/kg, s.c., was administered four times daily for 14 days and Met-Enk and PPE mRNA evaluated at various times (4-96 h) following drug discontinuation. Met-Enk, assayed by radioimmunoassay, was increased in the ventral (nucleus accumbens) but not dorsal (putamen/caudate) striatum, while PPE mRNA, assayed in whole striatum by Northern blotting was elevated. Both changes were seen early during withdrawal and lasted over 72 h. In situ hybridization revealed enhanced signal in the dorsal striatum, mostly laterally, and smaller increases in the rostral pole, core and shell of the nucleus accumbens. These observations indicate that during nicotine withdrawal, striatal enkephalinergic neurons undergo adaptative responses, which might contribute to the abstinence behavioral syndrome.