Effects of fibroblast growth factor-4 (k-FGF) on long-term cultures of human bone marrow cells

Fibroblast growth factor-4 (FGF-4), a highly mitogenic protein encoded by the k-fgf/hst oncogene, stimulates the growth of a variety of cells of mesenchymal and neuroectodermal origin. Addition of FGF-4 to human long-term bone marrow cultures increased both the cell density of the stromal layer and the number of hematopoietic colony forming cells in the cultures in a dose-dependent manner. Hematopoiesis in the stromal layer persisted for up to 8 months. Erythropoiesis was maintained for up to 4 weeks, but granulocytes were the predominant nonadherent cell type. Cultures treated with FGF had increased numbers of monocytes compared with control cultures and some CD14+, CD45+ monocytes could still be detected after 8 months of continuous culture. The addition of the growth factor increased the rate of growth of the stromal layer and appeared to delay its senescence. Subcultures made in the presence of FGF-4 had up to 10-fold increases in plating efficiency and grew as relatively uniform monolayers. These subcultures retained the capacity to support hematopoiesis for several months, while untreated subcultures, made without FGF-4, grew erratically and generally lost the capacity to support hematopoiesis within 4 to 6 weeks. The improved growth after subculture greatly enhanced the reliability of limit- dilution assays of multipotential hematopoietic stem cells that use stromal cell monolayers. The primary effect of FGF-4 appeared to be on the stromal cells of the long-term bone marrow cultures, but a direct effect on hematopoietic progenitors could not be ruled out.     

The role of glutathione status in the protection against ischaemic and reperfusion damage: effects of N-acetyl cysteine

It is known that myocardial ischaemia causes a marked decline of cellular thiol pool and of protein sulphydryl groups content. Reperfusion under these conditions results in oxydative damage which is concomitant with poor recovery of mechanical function. We have evaluated the role of glutathione status in the protection against ischaemic and reperfusion damage by treating the isolated rabbit hearts with N-acetylcysteine (10(-6) M), a sulphydryl group donor. Ischaemic and reperfusion damage was determined in terms of mechanical function, rate of lactate and creatine kinase (CPK) release, mitochondrial function and tissue content of reduced (GSH) and oxidized (GSSG) glutathione and of protein sulphydryl groups (SH). After 60 mins of ischaemia (induced by reducing coronary flow from 24 to 1 ml/min) followed by 30 mins of reperfusion there was an increase of diastolic pressure to 51.6 +/- 3.5 mmHg with only a 22% recovery of systolic pressure, massive CPK release and a deterioration in mitochondrial function. Tissue contents of GSH and of protein SH were severely decreased, while those of GSSG were increased. The GSH/GSSG ratio was reduced from the aerobic value of 50 to 13.4, suggesting that an oxidative stress has occurred. N-acetylcysteine infused for 60 mins before ischaemia determined a 38% increase in tissue content of GSH with no major changes of GSSG or protein SH. The ischaemic-induced decrease of GSH and protein SH was also limited by pretreatment with N-acetylcysteine and there was no accumulation of GSSG after reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reproducibility and reliability of first pass radionuclide ventriculography with Au-195m. Validation of Au-195m radionuclide ventriculography

Au-195m is a radio-isotope with an ultra-short half-life with which multiple sequential evaluations of ventricular function can be made. In order to evaluate the reliability and reproducibility of analyses of overall and regional ventricular function by radio-isotope ventriculography with Au-195m we studied 10 healthy volunteers and 12 patients with coronary artery disease. Each subject underwent 4 first-pass studies: 1 with Tc-99m and, 10 minutes later, 3 with Au-195m (2 basal studies separated by 3-5 minutes interval and, 10 minutes later, 1 after s.l. nitroglycerin administration). Regional wall motion was analyzed and ejection fraction and peak count rate were determined in each test. Our study showed that the ejection fraction obtained with Au-195m was reproducible (r = 0.98) and correlated well with the ejection fraction determined by using Tc-99m (r = 0.98). The values of the peak count rate obtained with Tc-99m were higher than those obtained with Au-195m. Due to the specially designed collimator and the technical characteristics of the gamma-camera we used, we were able to record sufficiently high count-rates to evaluate regional wall motion, and this analysis was also found to be reliable and reproducible. After s.l. nitroglycerin administration, normal volunteers showed a significant increase of ejection fraction in comparison with basal acquisitions (p less than 0.05), while a wide range of responses was observed in the group of patients with coronary artery disease. We conclude that radio-isotope ventriculography with Au-195m is reliable and reproducible and could be a valid method of monitoring rapid variations induced in overall and regional left ventricular function.     

Low-level laser therapy in different stages of rheumatoid arthritis: a histological study

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease of unknown etiology. Treatment of RA is very complex, and in the past years, some studies have investigated the use of low-level laser therapy (LLLT) in treatment of RA. However, it remains unknown if LLLT can modulate early and late stages of RA. With this perspective in mind, we evaluated histological aspects of LLLT effects in different RA progression stages in the knee. It was performed a collagen-induced RA model, and 20 male Wistar rats were divided into 4 experimental groups: a non-injured and non-treated control group, a RA non-treated group, a group treated with LLLT (780 nm, 22 mW, 0.10 W/cm², spot area of 0.214 cm², 7.7 J/cm², 75 s, 1.65 J per point, continuous mode) from 12th hour after collagen-induced RA, and a group treated with LLLT from 7th day after RA induction with same LLLT parameters. LLLT treatments were performed once per day. All animals were sacrificed at the 14th day from RA induction and articular tissue was collected in order to perform histological analyses related to inflammatory process. We observed that LLLT both at early and late RA progression stages significantly improved mononuclear inflammatory cells, exudate protein, medullary hemorrhage, hyperemia, necrosis, distribution of fibrocartilage, and chondroblasts and osteoblasts compared to RA group (p?<?0.05). We can conclude that LLLT is able to modulate inflammatory response both in early as well as in late progression stages of RA.     

Use of the Gait Profile Score for the evaluation of patients with joint hypermobility syndrome/Ehlers–Danlos syndrome hypermobility type

Gait analysis (GA) is widely used for clinical evaluations in various pathological states, both in children and in adults, such as in patients with joint hypermobility syndrome/Ehlers–Danlos syndrome hypermobility type (JHS/EDS-HT). Otherwise, GA produces a large volume of data and there is the clinical need to provide also a quantitative measure of the patient's overall gait. Starting from this aim some global indexes were proposed by literature as a summary measure of the patient's gait, such as the Gait Profile Score (GPS). While validity of the GPS was demonstrated for the evaluation of the functional limitation of children with Cerebral Palsy, no studies have been conducted in patients JHS/EDS-HT. The aim of our study was therefore to investigate the effectiveness of the GPS in the quantification of functional limitation of patients with JHS/EDS-HT. Twenty-one adult (age: 36.1 ± 12.7 years) individuals with JHS/EDS-HT were evaluated using GA and from GA data the GPS was computed. The results evidenced that the GPS value of patients was 8.9 ± 2.6, statistically different from 4.6 ± 0.9 displayed by the control group. In particular, all values of Gait Variable Scores (GVS) which compose the GPS were higher if compared to controls, with the exception of Pelvic Tilt and Foot Progression. The correlations between GPS/GVS and Lower Extremity Functional Scale (LEFS) showed significant relationship between GPS and the item 11 (“Walking 2 blocks”) (ρ = ?0.56; p < 0.05) and 12 (“Walking a mile”) of LEFS (ρ = ?0.76; p < 0.05). Our results showed that GPS and GVS seem to be appropriate outcome measures for the evaluation of the functional limitation during gait of patients with JHS/EDS-HT.