Probing insulin's secondary structure after entrapment into alginate/chitosan nanoparticles.

The aim of the present study was to probe the structural integrity of insulin after being entrapped into chitosan/alginate nanoparticles produced by ionotropic polyelectrolyte pre-gelation. By manipulating the alginate:chitosan mass ratio and the pH during nanoparticle production, desired nanoparticles with a mean size of 850 (+/-88)nm and insulin association efficiency of 81 (+/-2)% were obtained. Insulin secondary structure was assessed by Fourier transform infrared (FTIR) and circular dichroism (CD) after entrapment into nanoparticles and after release from the particles under gastrointestinal simulated conditions. FTIR second-derivative spectra and area-overlap compared to an insulin standard confirmed that no significant conformational changes of insulin occurred in terms of alpha-helix and beta-sheet content. Far-UV-CD spectra corroborated the preservation of insulin structure during the nanoparticle production procedure. The presented nanoparticulate system is a promising carrier for insulin oral delivery since it preserves insulin structure and therefore also, potentially, its bioactivity.     

Treatment of myofascial trigger points in common shoulder disorders by physical therapy: A randomized controlled trial [ISRCTN75722066]

Background  

Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders.     

Therapy of post-renal transplantation hyperlipidaemia: comparative study with simvastatin and fish oil

Background: Recipients of renal transplantation (RT) exhibit disturbances of serum lipids and apoproteins that may contribute to their cardiovascular morbidity and mortality. In our renal transplant department the hypercholesterolaemia prevalence at the first and fifth year of RT is 70.0% and 81.2%, respectively. Lipid-lowering therapy has been utilized in many Transplant Units. The aim of our study was to evaluate post-RT hyperlipidaemia control with simvastatin or fish oil. Method: Forty-three RT patients (26 men and 17 women) with persistent hypercholesterolaemia and stable graft function which were resistant to a lipid-lowering diet (American Heart Association Step Two) were randomized into two groups and treated for 3 months with simvastatin (S) (10 mg/day; n=25) and fish oil (F) (6 g/day; n=18). Total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), lipoprotein a (Lp(a)), apolipoprotein A1 (Apo A1), and apolipoprotein B (Apo B) were monitored and at the study baseline they were similar between the two groups. Results: No side effects were detected after 3 months of therapy. In group S, the concentrations of TC (271±46 mg% vs 228±49mg%; P <0.001), TG (180±78 vs 134±45; P<0.01), LDL-C (177& plusmn;40 vs 144±43; P <0.01) and Apo B (96±18 vs 82±16; P <0.001) were significantly reduced, and Apo A1 concentration had increased (135±24 vs 149±30; P <0.01). In group F, the concentrations of TC (266±25 vs 240±31; P <0.001), TG (203±105 vs 156±72; P=0.02) and HDL-C (63±15 vs 53±12; P <0.01) were significantly reduced. Conclusion: We concluded that low-dose simvastatin and fish oil are both effective and safe in correcting post-RT hyperlipidaemia. Further prospective studies with larger follow-up are needed to clarify whether this therapy has an impact on cardiovascular morbidity and mortality in RT patients.     

L-arginine reverses the antinatriuretic effect of cyclosporin in renal transplant patients

BACKGROUND: Cyclosporin has been shown to facilitate renal vasoconstriction and to have an antinatriuretic effect. The existence of an interference of cyclosporin with the vasodilating properties of endothelium mediated by nitric oxide production could mediate these effects. On the other hand, the infusion of the nitric oxide precursor L-arginine has been shown to induce renal vasodilatation and to facilitate natriuresis in normal volunteers. We have investigated the renal effects of the administration of an infusion of L-arginine in renal transplant patients chronically treated with cyclosporin. To facilitate the analysis of the data the effects of the administration of a similar dose of cyclosporin on renal function during the infusion of a vehicle were also investigated during the administration of a vehicle of L-arginine. DESIGN: Ten male renal transplant patients, chronically treated with cyclosporin and with a stable renal function were studied during 2 consecutive days after the administration of the usual morning dose of cyclosporin. The first day they received an intravenous infusion of vehicle and the second the infusion of graded doses of L-arginine (50, 100, 150 mg/kg/h) during 3 consecutive h. RESULTS: The first day, after cyclosporin administration a significant fall (P < 0.01) was observed in natriuresis and kaliuresis in the absence of changes in renal plasma flow and glomerular filtration rate. After the administration of L-arginine significant (P < 0.01) increases of renal plasma flow, glomerular filtration rate, and natriuresis were seen. The increase in blood levels of cyclosporin after its administration did not differ between days 1 and 2. CONCLUSION: These results indicate that L-arginine facilitates renal vasodilatation and natriuresis in renal transplant patients. Furthermore, the observed increase in sodium excretion could indicate that L-arginine counteracts the antinatriuretic effect of cyclosporin.      

Involvement of reactive oxygen intermediates in tumor necrosis factor alpha-dependent bacteriostasis of Mycobacterium avium.

We studied the involvement of reactive oxygen intermediates and reactive nitrogen intermediates in the bacteriostasis of two Mycobacterium avium strains differing in virulence by resident peritoneal macrophages. We found that both the highly virulent strain (25291) and the low-virulence strain (1983) of M. avium induced superoxide production but inhibited nitrite production in vitro. This inhibition was due to the production of superoxide, a nitric oxide scavenger. The stimulation of superoxide production was two- to fivefold higher in strain 1983-infected than in strain 25291-infected resident peritoneal macrophages and was independent of contaminating T cells or NK cells. Superoxide secretion was dependent on the tumor necrosis factor (TNF) produced endogenously by the macrophages. This was also true when macrophages were isolated from infected mice. Addition of TNF to the infected resident peritoneal macrophages caused only a slight, albeit significant, increase in superoxide production by strain 25291-infected macrophages. Incubation of resident peritoneal macrophages with different scavengers of reactive oxygen intermediates showed that strain 1983 was susceptible to hydrogen peroxide produced by resident peritoneal macrophages. Strain 25291 was shown to decrease superoxide secretion inside heavily infected bone marrow-derived macrophages. This strain was also shown to be a better trigger for production of reactive oxygen intermediates than strain 1983. In summary, strain 1983 induced high levels of TNF synthesis that acted in an autocrine fashion to stimulate production of reactive oxygen intermediates by macrophages leading to growth restriction mediated by hydrogen peroxide. The highly virulent strain 25291 induced low levels of TNF synthesis, and therefore little reactive oxygen intermediate production, and could also inhibit superoxide production by the infected macrophages.     

Positional cloning of the gene for X-linked retinitis pigmentosa 3: homology with the guanine-nucleotide-exchange factor RCC1

The gene for retinitis pigmentosa 3 (RP3), the most frequent form of X- linked RP (XLRP), has been mapped previously to a chromosome interval of less than 1000 kbp between the DXS1110 marker and the OTC locus at Xp21.1-p11.4. Employing a novel technique, YAC Representation Hybridization (YRH)', we have recently identified a small XLRP associated microdeletion in this interval, as well as several putative exons including the 3' end of a gene that was truncated by the deletion. cDNA library screening and sequencing of a cosmid centromeric to the deletion has now enabled us to identify numerous additional exons and to detect several point mutations in patients with XLRP. The predicted gene product shows homology to RCC1, the guanine-nucleotide- exchange factor (GEF) of the Ras-like GTPase Ran. Our findings suggest that we have cloned the long-sought RP3 gene, and that it may encode the GEF of a retina-specific GTP-binding protein.