Extraction, characterization and in vivo neuromodulatory activity of phytosterols from microalga Dunaliella tertiolecta

In recent years, a great deal of research has been devoted to identify new natural sources of phytosterols and to improve methods for their recovery and purification. In this regard, unexplored natural sources of bioactive ingredients are gaining much attention since they can lead to the isolation of new compounds or bioactivities. The field of available natural sources has been further increased by including algae and, even more interestingly, microalgae. In the present study, a multidisciplinary approach has been used considering, in an integrated view, extraction, chemical composition and bioactivity of phytosterols from the microalga Dunaliella tertiolecta. A novel methodology to extract, separate and characterize microalgal-derived phytosterols has been developed. In addition, recoverable and reusable eluents have been selected in order to reduce the quantities of employed organic solvents. Finally, we addressed the question whether orally administered phytosterols reach the brain and if those interfere with the major neurotransmitter systems, such as the dopaminergic, serotoninergic and noradrenergic ones, in several brain areas of rats. Flash Liquid Chromatography has been used to separate the Total Sterol (TS) fraction, composed of twelve sterols, with a purity of 97.87% and a recovery percentage of 98%, while the "flash version" of Silver Ion Liquid Chromatography has been used to purify the most abundant phytosterols in TS, (22E,24R)- methylcholesta-5,7,22-trien-3β-ol (ergosterol) and (22E,24R)-ethylcholesta-5,7,22-trien-3β-ol (7-dehydroporiferasterol), with a purity of 97.4%. These two combined methods did not need sophisticated technologies but only cheap laboratory supplies. Moreover, the possibility of recovering and recycling the solvents used as eluents made it a cleaner process. Finally, for the first time, a neuromodulatory action of Dunaliella tertiolecta-derived phytosterols has been found in selective brain areas of rats.     

Expression and localization of augmenter of liver regeneration in human muscle tissue

Mitochondrial DNA (mt-DNA) disorders and abnormal regulation of nuclear-derived proteins devoted to the cross-talk between the two cellular genomes have recently interested researchers in the field of neuromuscular diseases. We have identified, isolated and sequenced a new gene, augmenter of liver regeneration (ALR) that stimulates in vivo hepatocyte proliferation and up-regulates mt-DNA expression and ATP production. ALR protein (Alrp) is mainly located, in rat, in the mitochondrial inter-membrane space and its mRNA is particularly abundant in brain, muscle, testis and liver, tissues whose activity is mostly dependent on mitochondrial metabolism. Studies on rat Alrp sequence revealed the presence of homologous amino-acid sections into proteins derived from mouse, human, Drosophyla, plants and even DNA viruses. In this article, we evaluated ALR expression in normal human muscular tissues, both as protein and as mRNA. The data, obtained by molecular biology, immunohistochemistry and electron microscopy, demonstrated that: (i) Alrp and ALR mRNA are present in human muscular tissue; (ii) Alrp is particularly expressed in muscular fibres rich in mitochondria; (iii) Alrp is localized in the mitochondrial inter-membrane space or associated to mitochondrial cristae; and (iv) in subjects younger then 35 years of age, ALR mRNA expression is different between male and female subjects. In conclusion, the present data set Alrp, as a factor associated with mitochondria also in human tissue, call for future studies aimed at establishing Alrp as an important factor involved in the molecular events that trigger neuromuscular diseases.     

ABO blood group-related waiting list disparities in liver transplant candidates: effect of the MELD adoption

BACKGROUND: Blood group O candidates remain on the waiting list for a liver transplant for a longer time than candidates of other blood groups. Herein, we analyzed potential factors affecting waiting times in the period that preceded the introduction of the model for end-stage liver disease (MELD) and in MELD era, remarking possible corrections introduced by the adoption of the MELD. METHODS: Our analysis was entirely based on data obtained from the "Organ Procurement and Transplantation Network", referring to the periods before and after the adoption of the MELD. RESULTS: In the MELD era, taking into consideration all candidates, the cumulative probability of remaining on the waiting list significantly diminished whereas that of undergoing transplantation significantly increased when compared with the pre-MELD era. However, group O candidates maintained the lowest cumulative probability of undergoing liver transplant, in all MELD classes, and the highest percentage of list removal for death/too sick. What caused the highest disadvantage for group O, in both eras, was the use of group O organs for ABO-compatible transplants, even in the absence of urgency. In candidates receiving ABO-compatible organs a significantly lower graft survival rate was observed compared with candidates receiving ABO-identical organs, even when the analysis was adjusted for the MELD score. CONCLUSIONS: The introduction of the MELD significantly reduced the waiting time for all candidates as also the shift of group O organs. Limiting ABO-compatible organs exclusively to urgent cases would have a positive effect not only in terms of individual justice, but also terms of in general utility, considering the effect of ABO-matching on graft survival.     

Nutritional state and energy balance in cirrhotic patients with or without hypermetabolism: Multicentre prospective study by the ‘Nutritional Problems in Gastroenterology’ Section of the Italian Society of Gastroenterology (SIGE)

BACKGROUND AND AIMS: A total of 334 stable, compensated cirrhotic patients admitted to 10 Italian Gastroenterology Units were included in a prospective study to evaluate nutritional state and energy balance in liver cirrhosis. MATERIALS AND METHODS: Nutritional state and calorie intake were examined in the total population, while adequacy of calorie intake versus measured total energy expenditure was evaluated in a comparable subpopulation and in 40 matched controls, by computing the energy balance. RESULTS: Our data demonstrated that: (i) malnutrition was present in 25% of the total patients and significantly correlated with the Child's group (A=16%; B=25%; C=44%); (ii) the type of malnutrition is influenced by mBEE: normometabolic patients exhibit a significant (p<0.005) reduction of mid-arm fat area while both hypermetabolic and hypometabolic patients show a significant (p<0.005) decline in kg of free fat mass; (iii) normometabolic and hypometabolic patients have a negative energy balance, due to a high level of physical activity (127+/-14 kJ) in the first group and a reduced energy intake/kg body weight (102+/-12 kJ) in the second; (iv) hypermetabolic patients have a positive energy balance due to decreased daily physical activity/kg body weight (108+/-28 kJ); (v) malnourished and normometabolic patients eat a significantly (p<0.05) reduced percentage of protein whereas malnourished and hypermetabolic patients eat a significantly increased percentage of fat (p<0.05). CONCLUSION: Although multivariate regression analysis confirms that the Child-Pugh's score is a better independent predictor of malnutrition, the measure of REE, TEE, calorie intake and energy balance need to be routinely performed in cirrhotic patients, in order to recognise hypermetabolic and hypometabolic patients (approximately 30%) in whom the nutritional and metabolic parameters are indispensable as a basis for designing and prescribing personalised nutritional strategies that can treat muscle malnutrition and thus improve the morbidity and mortality rates.     

Lamivudine and alpha-interferon in combination long term for precore mutant chronic hepatitis B

BACKGROUND/AIMS: Alpha-interferon (alpha-IFN) and lamivudine are the two licensed drugs for patients with chronic hepatitis B, however, their efficacy in precore mutant chronic hepatitis B is limited. The aim of this study was to investigate the efficacy of 1 year alpha-IFN-lamivudine combination therapy for anti-HBe/hepatitis B virus- (HBV)-DNA positive patients. METHODS: Between 1997 and 1999, 29 consecutive anti-HBe/HBV-DNA positive patients entered this prospective pilot study. Patients received 100mg lamivudine orally daily and alpha-IFN 6 million units (MU) three times weekly for 52 weeks. All patients were followed-up for 12 months after stopping therapy. Primary end points were loss of serum HBV-DNA and alanine transaminase normalization at week 52. RESULTS: Overall, the end-treatment biochemical and virological response was 93% while the sustained response at week 104 was 14%. HBV-DNA negative patients did not experience a viral breakthrough during treatment; no tyrosine-methionine-aspartate-aspartate amino acid motif of HBV polymerase (YMDD) variant emerged. At week 52, 46% of patients with paired liver biopsies slides available, showed an histological improvement (histological activity index > or =2). CONCLUSIONS: Combination of lamivudine and interferon for 1 year is followed by high end-treatment virological and biochemical response rates, by improvement of liver histology and by the prevention of the emergence of YMDD mutation; however, the sustained response rate remains low.     

Improved efficacy of 10-Day sequential treatment for Helicobacter pylori eradication in children: a randomized trial

BACKGROUND & AIMS: The currently recommended first-line eradication treatment of Helicobacter pylori in children is usually successful in about 75%. Recently, in adults, a novel 10-day sequential treatment has achieved an eradication rate of 95%. The aim of the study was to assess the H pylori eradication rate of the sequential treatment regimen compared with conventional triple therapy in children. METHODS: Seventy-eight consecutive children with H pylori infection were randomized to receive either sequential treatment (omeprazole plus amoxicillin for 5 days, followed by omeprazole plus clarithromycin plus tinidazole for another 5 days) (n = 38; 15 boys [39.5%]; median age, 11.0 years [range, 3.3-16 years]) or triple therapy (omeprazole, amoxicillin, and metronidazole) for 1 week (n = 37; 15 boys [40.5%]; median age, 9.9 years [range, 4.3-16 years]). H pylori infection was based on 2 out of 3 positive tests results: 13C-urea breath test, rapid urease test, and histologic analysis. Eradication was assessed by 13C-urea breath test 8 weeks after therapy. RESULTS: Seventy-four patients completed the study. H pylori eradication was achieved in 36 children receiving sequential treatment (97.3%; 95% confidence interval, 86.2-99.5) and 28 children receiving triple therapy (75.7%; 95% confidence interval, 59.8-86.7) (P < .02). Compliance with therapy was good (>95%) in all. CONCLUSIONS: Our study shows, for the first time in children, that 10-day sequential treatment achieves a higher eradication rate than standard triple therapy, which is consistent with the results of adult studies.