Gene therapy of Hunter syndrome: evaluation of the efficiency of muscle electro gene transfer for the production and release of recombinant iduronate-2-sulfatase (IDS)

Mucopolysaccharidosis type II (MPSII) is an inherited disorder due to a deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). The disease is characterized by a considerable deposition of heparan- and dermatan-sulfate, causing a general impairment of physiological functions. Most of the therapeutic protocols proposed so far are mainly based upon enzyme replacement therapy which is very expensive. There is a requirement for an alternative approach, and to this aim, we evaluated the feasibility of muscle electro gene transfer (EGT) performed in the IDS-knockout (IDS-ko) mouse model. EGT is a highly efficient method of delivering exogenous molecules into different tissues. More recently, pre-treatment with bovine hyaluronidase has shown to further improve transfection efficiency of muscle EGT. We here show that, by applying such procedure, IDS was very efficiently produced inside the muscle. However, no induced IDS activity was measured in the IDS-ko mice plasma, in contrast to matched healthy controls. In the same samples, an anticipated and rapidly increasing immune response against the recombinant protein was observed in the IDS-ko vs control mice, although reaching the same levels at 5 weeks post-injection. Additional experiments performed on healthy mice showed a significant contribution of hyaluronidase pre-treatment in increasing the immune response.

Gastrointestinal telangiectasia: a study by EGD, colonoscopy, and capsule endoscopy in 75 patients

BACKGROUND

The distribution of lesions in the gastrointestinal tract in patients with sporadic telangiectasia is at present unknown.

PATIENTS AND METHODS

75 patients with sporadic telangiectasia underwent esophagogastroduodenoscopy (EGD), capsule endoscopy, and colonoscopy. Endoscopic diagnosis of telangiectasia and gastrointestinal bleeding were required for enrollment in the study. Hemorrhagic diathesis, co-morbidity, number of blood transfusions, and subsequent management were also noted.

RESULTS

35 of the patients presented with gastroduodenal vascular lesions, 51 with small-bowel lesions, and 28 with colonic lesions. 67 % of patients in whom EGD found telangiectasia also presented small-bowel vascular lesions at capsule endoscopy and 43 % colonic lesions at colonoscopy. 54 % percent of patients with positive colonoscopy also presented gastroduodenal lesions and 48 % small-bowel lesions. Patients with known duodenal lesions were more likely to have small-bowel lesions at capsule endoscopy (odds ratio [OR] 10.19, 95 % CI 2.1 - 49.33, P = 0.003). Patients with associated diseases, such as liver cirrhosis, chronic renal failure, or heart valvulopathy, presented more severe disease requiring blood transfusions (OR 6.37, 95 % CI 1.39 - 29.2, P = 0.015). The number of blood transfusions correlated with the number of sites affected ( R = 0.35, P = 0.002). The detection of new lesions at capsule endoscopy allowed new treatment in 46 % of patients. Mean follow-up was 18 months.

CONCLUSIONS

Sporadic telangiectasia is a multifocal disease potentially involving the whole digestive tract. Patients with duodenal telangiectasia show a higher risk of jejunal or ileal lesions. Capsule endoscopy is a useful diagnostic tool for the detection of such small-bowel vascular lesions, indicating a more specific prognosis and treatment strategy.

Systematic review of dysplasia after restorative proctocolectomy for ulcerative colitis

Background

The aim of this systematic review was to assess the prevalence and site of dysplasia after restorative proctocolectomy (RPC) for ulcerative colitis (UC), and to identify risk factors that could be used in a surveillance programme.

Methods

Medical databases were searched for potentially relevant publications between 1978 and 2006. Studies that dealt with RPC for UC and postoperative surveillance were included. Two researchers independently performed study selection, quality assessment, data extraction and analysis.

Results

Twenty-three observational studies and case series were included, with a total of 2040 patients. The pooled prevalence of confirmed dysplasia in the pouch, anal transitional zone or rectal cuff was 1·13 (range 0–18·75) per cent. The prevalence of high-grade dysplasia, low-grade dysplasia and indefinite for dysplasia was 0·15 (range 0–4·49), 0·98 (range 0–15·62) and 1·23 (range 0–25·28 per cent) respectively. Dysplasia was equally frequent in the pouch and rectal cuff or anal transitional zone. Dysplasia and cancer identified before or at operation seemed to be significant predictors of the development of dysplasia. Pouchitis and duration of follow-up were not of predictive value.

Conclusion

Although based on low-level evidence from uncontrolled studies, the prevalence of dysplasia observed after RPC was remarkable. A surveillance programme that takes into account the risk factors found is therefore advocated.

Genetic testing improves the diagnosis of adult type hypolactasia in the Mediterranean population of Sardinia

OBJECTIVE

Recently, the C/T-13910 polymorphism on chromosome 2q21 in North-European populations has been found completely associated with lactase activity and its genetic typing proposed as first-stage screening test for adult hypolactasia. However, the C/T-13910 variant in some sub-Saharan African groups is not a predictor of lactase persistence. In this work, we wanted to verify if in the Mediterranean island of Sardinia, located in Southern Europe, the C/T-13910 polymorphism may be useful or not for the diagnosis of adult type hypolactasia.

DESIGN

Validation study of a genetic testing for adult type hypolactasia in Sardinians.

SETTING

Brotzu Hospital and Microcitemico Hospital, Cagliari, Italy.

SUBJECTS

The sample consisted in 84 Sardinian individuals (63 women and 21 men; range 20-73 years) selected from a group of 832 patients.

METHODS

Genetic testing was compared to an improved test obtained by a combination of different breath hydrogen tests and clinical assessment.

RESULTS

We found that all 49 individuals with lactose malabsorption, demonstrated by a combination of different breath hydrogen tests and clinical assessment, carried the C/C-13910 genotype associated with lactase non-persistence, 23 individuals with lactose normal absorption carried the C/T-13910 genotype associated with lactase persistence and only one person with the above phenotype showed a discordant C/C-13910 genotype. The genetic testing showed very high sensitivity, specificity, positive and negative predictive values of 100, 95.8, 98 and 100%, respectively.

CONCLUSIONS

Sardinians, unlike some ethnic groups in sub-Saharan Africa, show the same genetic association of hypolactasia with the C/T-13910 variant as other North-European populations. The genetic testing for the C/T-13910 variant may contribute to improving the diagnosis of adult type hypolactasia.

13C-octanoic acid breath test in functional and organic disease: critical review of literature

The 13C-octanoic acid breath test is considered a useful tool to measure gastric emptying both in physiological and pathological conditions. Many studies have concerned functional dyspepsia. Recently, breath test has been used in predicting a delayed gastric emptying in subsets of dyspeptic symptoms. In detail only postprandial fullness and vomiting are resulted significantly correlated with delayed solid emptying. Besides in the patients with dyspepsia and irritable bowel syndrome associated, intestinal disturbances did not seem to contribute to delay gastric emptying. In diabetic patients octanoate test has confirmed the percentages of delayed emptying obtained by means of scintigraphy. In other organic states (celiac disease, cirrhosis, renal failure, neurological disease, etc) most of reports have proved a delayed emptying of solids. In GERD and ulcer disease gastric function is resulted normal, being accelerated in distal gastrectomy and in hyperemesis gravidarum. From pathophysiological point of view Helicobacter pylori, extrinsic autonomic neuropathy (apart from diabetes) and autoimmunity do not seem to relate with gastric emptying, both in functional and organic disease.

Effects of iron manipulation on trace elements level in a model of colitis in rats

AIM: Trace elements (TE) metabolism is altered in inflammatory bowel diseases. TE (zinc and copper) are constituents of antioxidant enzymes. Iron is involved in the pathogenesis of chronic inflammation. The aim was to evaluate zinc and copper status and the effects of iron manipulation in experimental colitis.

METHODS: Twenty-four male Sprague-Dawley rats were divided into four groups: standard diet, iron-deprived diet, iron-supplemented diet, and sham-treated controls. Macroscopic damage was scored. DNA adducts were measured in the colon. Liver and colonic concentration of TE were measured.

RESULTS: Macroscopic damage was reduced in iron-deprived groups and increased in iron-supplemented rats. Damage to the DNA was reduced in iron-deprived groups and increased in iron-supplemented groups. Liver and colonic iron concentrations were reduced in iron-deprived and increased in iron-supplemented rats. Liver zinc concentration was reduced after supplementation whereas colonic levels were similar in controls and treated rats. Liver copper concentration was reduced in all the colitic groups except in the iron-supplemented group whereas colonic concentration was increased in iron-deprived rats.

CONCLUSION: Iron deprivation diminishes the severity of DNBS colitis while supplementation worsens colitis. Zinc and copper status are modified by iron manipulation.

Ileostomy for constipation: long-term postoperative outcome

BACKGROUND AND AIMS

Idiopathic constipation is a rare indication for ileostomy construction. The aim of the study was to evaluate the success of ileostomy in treatment of severe constipation. Also to analyse the surgical complications and re-operation rate to identify any factors potentially predictive of outcome.

PATIENTS AND METHODS

This retrospective study analysed the long-term outcome of 24 ileostomies constructed for constipation. The ileostomy construction was performed in 13 patients during large bowel/rectum resection, in 6 after a full laparotomy and in 5 through an abdominal wall trephine alone. We analysed the surgical complications and the re-operation rate according any factors potentially predictive of outcome.

RESULTS

One (4%) patient had persistent constipation after stoma creation. Surgical complications occurred in 11 (46%): retraction in 6 (25.0%), peristomal sepsis in 3 (12.5%) and parastomal hernia in 2 (8.1%). Refashioning of the stoma was necessary in 7 (29%) patients. Previous abdominal surgery, end ileostomy, ileostomy constructed after large bowel resection or laparotomy were associated with a significantly higher incidence of stomal complications while age, duration of follow up, major complication and ileostomy created after bowel resection were associated to a significantly higher re-operation rate (P < 0.05). Multivariate analysis identified end ileostomy and ileostomy created after bowel resection as independent risk factors for surgical complication and re-operation, respectively (P < 0.05).

CONCLUSIONS

Ileostomies were associated with a high frequency of complications, but most could be managed by minor surgical interventions. Patients who are considered for an ileostomy for severe idiopathic constipation should, where possible, have a loop ileostomy through a trephine rather than a laparotomy.

Why Do We Need New Gene Therapy Viral Vectors? Characteristics, Limitations and Future Perspectives of Viral Vector Transduction

The use of viruses to transduce genes of interest into mammalian cells has been extremely revolutionary, both in terms of laboratory research and for clinical purposes. This approach has allowed expression and over-expression of proteins of interest as well as the understanding of both virus life cycles and eukaryotic cell mechanisms. Beginning in the late eighties gene transduction has been applied to clinical trials but mainly restricted to cancer treatment and genetic diseases. More recently it has been proposed for the cure of infectious diseases (AIDS), vascular diseases and others (Alzheimer's and Parkinson's disease). Viral vectors have been progressively modified in order to increase their transduction efficiency and to reduce their toxicity, immunogenicity and inflammatory potential. In this respect, much has been done in the last few years. By adding genes belonging to other viral species to the vectors' DNA, scientists were able to re-direct their tissue-specificity or to control protein expression. More recently, in the attempt of overcoming the limitations of each viral species, so-called chimeric viral vectors have been generated by combining favourable features of two or more different viruses into one. This review summarises the main characteristics of the most common viral vectors, including their advantages, limitations and possible future applications. It also briefly discusses development and evolution of chimeric vectors, treated in more details along this entire issue. Finally, we evaluate basic safety aspects, mandatory to consider for the clinical application of viral gene transduction.

Effects of iron deprivation or chelation on DNA damage in experimental colitis

BACKGROUND AND AIMS

In inflammatory bowel diseases iron contributes to the formation of DNA adducts through the production of hydroxyl radicals. The aim of our study was to evaluate the effects of dietary or pharmacological iron deprivation in an experimental model of colitis in the rat and its potential protective effect against DNA damage.

METHODS

Colitis was induced in rats by intracolonic instillation of dinitrobenzene sulphonic acid. Rats were assigned to an iron-deprived diet or to desferrioxamine preceding the induction of colitis. The severity of colitis was assessed by the presence of bloody diarrhea, colonic macroscopic damage score, body-weight variations and the amount of DNA colonic adducts. Hepatic and colonic iron concentrations were measured.

RESULTS

Treated rats experienced less diarrhea and did not lose weight in comparison to untreated animals. The macroscopic damage score was significantly reduced in the iron-deprived diet for the 5-week group (P=0.03). Liver and colonic iron levels were significantly more reduced in the iron-deprived groups than in the standard diet group (P<0.03 and P<0.01 after a 3- and 5-week iron-deprived diet, respectively). DNA adduct formation was significantly reduced in the groups deprived of iron for 5 weeks (P<0.001) or treated with desferrioxamine (P<0.01).

CONCLUSIONS

The degree of colitis caused by DNBS is macroscopically improved by dietary iron deprivation and to a lesser extent by pharmacological chelation; genomic damage is reduced by dietary iron deprivation or chelation, and this may have clinical implications on cancer prevention.

An experimental swine model of small bowel cross transplantation

AIM

In this study we evaluated the possibility of performing a cross small bowel transplantation (CrSBTx) in which, at the same time, 2 pigs were both donors and later recipients of intestinal grafts. The hemodynamic and metabolic impact of this original transplantation model on the animals was determined.

METHODS

Ten large White adult female pigs underwent a 2 stage procedure. The principal intraoperative hemodynamic and metabolic parameters were measured at different times during the operation. In the 3 days that followed the operation, renal function, liver and pancreatic damage were investigated.

RESULTS

Our surgical model permits us to keep excellent hemodynamic and metabolic stability with low mortality.

CONCLUSION

The need of half of animals with respect to conventional models represents an ethical and economic advantage of CrSBTx and we propose it for intestinal transplant studies in large animals.

Quality of life in patients with an ileostomy

AIM

Temporary or permanent ileostomy is a common procedure in colorectal surgery. Our aim was to assess the impact of ileostomy on quality of life and the relevant risk factors.

METHODS

A 33-question questionnaire was sent, by mail, to 74 patients (over 70, between 70 and 50 and under 50 y old). The questionnaire explored 5 parameters of function: systemic symptoms, bowel symptoms, functional impairment, social impairment and emotional impairment. Further questions investigated the need for a nurse or relative to assist with management of the stoma, the frequency of changing the bag and the appliance, diet and the ability of patients to attend their normal daily activity.

RESULTS

Thirty-four patients completed the questionnaire. The final quality of life score was similar for all the 3 age groups but elderly patients needed more assistance in the stoma management. The quality of life scores in males patients were significantly better than in females. No statistically significant difference was observed comparing loop ileostomy versus end ileostomy and Crohn's disease versus ulcerative colitis.

CONCLUSIONS

Quality of life is not influenced by age, underlying inflammatory disease or type of ileostomy. Males report less impact on quality of life than women.

Biphasic behavior of the kinetics of 31P-containing metabolites in ischemic porcine kidneys

The assessment of kidney viability before transplantation (with a view of discarding nonviable organs) remains an obstacle to confidently extending organ harvesting to marginal donors. In the present study phosphorus magnetic resonance spectroscopy was used to monitor metabolic changes in (31)P-containing metabolites in isolated porcine kidneys. After various warm ischemia times, the organs were stored at 0 degrees C. Time-dependent changes in the phosphomonoester/inorganic-phosphate ratio were recorded at 0 degrees C were shown to follow a biexponential decay. The first-order kinetic rate constant of the short-time decay was strongly dependent on the warm ischemia time, a result that was discreted in terms of the underlying biochemistry. The metabolic events responsible for the dramatic decrease in phosphomonoester/inorganic phosphate ratio that occur immediately after organ perfusion and storage, suggest that any procedure to minimize organ damage must occur immediately after harvesting.

[Lombardy regional project: prevention of occupational tumors]

In Lombardy, the regional project "Prevention of occupational cancers" is ongoing. The main objectives of this project are to identify work environments in which there might be a possible exposure to carcinogenic substances and to elaborate preventive measures. A casual sample of 250 working settings representing the different economic activities has been selected and evaluated. The 10% of the examined workplaces showed a possible exposure to chemical carcinogens. The most common carcinogens were trichloroethylene, preparation of plastics materials containing acrylonitrile-butadiene-stirene, formaldehyde, wood dust, hexavalent chromium, silica and polycyclic aromatic hydrocarbons. Galvanic industries, Bitumen production and placing companies and Plastics processing plants will be studied for environmental and biological monitoring and for the development of preventive measures.

Non-viral transfer approaches for the gene therapy of mucopolysaccharidosis type II (Hunter syndrome)

AIMS

Hunter syndrome is a rare X-linked lysosomal storage disorder caused by the deficiency of the housekeeping enzyme iduronate-2-sulphatase (IDS). Deficiency of IDS causes accumulation of undegraded dermatan and heparan-sulphate in various tissues and organs. Approaches have been proposed for the symptomatic therapy of the disease, including bone marrow transplantation and, very recently, enzyme replacement. To date, gene therapy strategies have considered mainly retroviral and adenoviral transduction of the correct cDNA. In this paper, two non-viral somatic gene therapy approaches are proposed: encapsulated heterologous cells and muscle electro-gene transfer (EGT).

METHODS

Hunter primary fibroblasts were co-cultured with either cell clones over-expressing the lacking enzyme or with the same incorporated in alginate microcapsules. For EGT, plasmid vector was injected into mouse quadriceps muscle, which was then immediately electro-stimulated.

RESULTS

Co-culturing Hunter primary fibroblasts with cells over-expressing IDS resulted in a three- to fourfold increase in fibroblast enzyme activity with respect to control cells. Fibroblast IDS activity was also increased after co-culture with encapsulated cells. EGT was able to transduce genes in mouse muscle, resulting in at least a tenfold increase in IDS activity 1-5 weeks after treatment.

CONCLUSION

Although preliminary, results from encapsulated heterologous cell clones and muscle EGT encourage further evaluations for possible application to gene therapy for Hunter syndrome.

Uptake of recombinant iduronate-2-sulfatase into neuronal and glial cells in vitro

Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is a congenital storage disorder resulting from mutations on the iduronate-2-sulfatase (IDS) gene. The disease shows variable clinical phenotypes from severe to mild with progressive neurological dysfunction. The therapeutic options for treatment of MPS II are limited and currently no specific therapies are available; the problem is further compounded by difficulties in delivering therapeutic agents to the central nervous system (CNS). In this work, as a potential treatment for this disease, the transfer of the recombinant IDS enzyme into brain cells has been studied in vitro. Two different approaches to obtain recombinant IDS have been utilized: production of the recombinant enzyme by a transfected human clone (Bosc 23 cells); production of the recombinant enzyme by adenoviral transduction of neuronal (SK-N-BE) or glial (C6) cells. Our data indicate that the transfected as well as the infected cells produce a large amount of the IDS enzyme, which is efficiently endocytosed into neuronal and glial cells through the mannose 6-phosphate (M6P) receptor system. Somatic gene therapy appears therefore to be suitable to correct IDS deficiency in brain cells.

Stable free radicals as ubiquitous components of red wines

A stable ESR signal, centred at g = 2.0037 +/- 0.0002, characterised by a single resonance and assignable to a free radical, was found in all the bottled red wines, both commercial and experimental, that we have examined. The radical concentration was calculated to be in the range of 5-82 nM. After exposure of the wines to air for a few minutes a two fold increase of the ESR signal, followed by a slow decrease with time, was observed. The intensity of ESR signal in experimental red wines, was found to increase with the ageing of the wines and was strictly correlated to the total content of polyphenols. The formation of semiquinone radicals of polyphenols is suggested as one possible mechanism leading to the presence of stable free radicals in red wines.

Properties of purified cytosolic isoenzyme I of Cu,Zn-superoxide dismutase from Nicotiana plumbaginifolia leaves

The isoenzyme I of cytosolic Cu,Zn-superoxide dismutase (SOD) from Nicotiana plumbaginifolia (tobacco) leaves has been purified to apparent homogeneity. The relative molecular mass of the native isoenzyme, determined by gel filtration chromatography, is about 33.2 kDa. SDS-polyacrylamide gel electrophoresis shows that the enzyme is composed of two equal subunits of 16.6 kDa The isolectric point, assayed by isoelectric focusing, in the pH range of 3.5-6.5, is 4.3. The enzyme stability was tested at different temperatures, pH, and concentration of inhibitors (KCN and H(2)O(2)). The catalytic constant (k(cat)) was 1.17 +/- 0.14 x 10(9) M(-1) s(-1) at pH 9.9 and 0.1 M ionic strength. The activation energy of the thermal denaturation process is 263 kJ mol(-1). The electrostatic surface potential of the modeled tobacco Cu,Zn-SOD I was calculated showing that the functional spatial network of charges on the protein surface has been maintained, independently of the amino acid substitution around the active sites.

Mucus altering agents as adjuncts for nonviral gene transfer to airway epithelium

Nonviral vectors have been shown to be a safe and valid alternative to recombinant viruses for gene therapy of cystic fibrosis (CF). Nevertheless, gene transfer efficiency needs to be increased before clinical efficacy is likely in man. One barrier to increased efficacy is normal airway mucus. Using an ex vivo model of sheep tracheal epithelium, we show that this barrier can, in part, be overcome by treatment with the mucolytic agents, Nacystelyn or N-acetylcysteine using either a cationic lipid or a cationic polymer as the gene transfer agent. Further, in vivo application of either Nacystelyn or the anticholinergic glycopyrrolate, both clinically used agents, resulted in increased reporter gene expression in the mouse lung, but no significant correction of the bioelectric defect in CF null mice. These results, whilst unlikely to be sufficient in themselves to achieve clinically relevant gene therapy, may be a further useful step in the attainment of this goal.

Life table analysis of hernia following end colostomy construction

OBJECTIVE

To study the long-term hernia rate and risk factors after end colostomy construction.

PATIENTS AND METHODS

86 patients with a permanent end colostomy constructed over 5 years were examined and interviewed. There were 35 men and the mean age was 56.5 (28-87) years. Risk factors which were analysed included emergency operation, age over 60 years, obesity, steroids, cancer, infection at the stoma site, smoking and chronic obstructive airways disease.

RESULTS

Para-colostomy hernia occurred in 12/86 cases (13.9%). The cumulative recurrence rose with duration of follow up. Overall 10/45 patients (22%) over 60 years developed hernia vs. 2/41 patients (4.8%) less than 60 years (P=0.02). There were no other risk factors that correlated with para-colostomy hernia.

CONCLUSIONS

These data indicate that the incidence of colostomy related hernia increases with follow up and is significantly higher in patients over the age of 60. Other risk factors, particularly obesity and coexisting cardiorespiratory disease, have no impact.

Deuterium nuclear magnetic resonance for evaluating the metabolic status of livers subjected to warm ischemia

BACKGROUND

The development of reliable methods for assessing the viability of currently available livers is expected to increase the number of successful transplantations.

METHODS

2 H nuclear magnetic resonance (NMR) was used to search for metabolic markers of ischemia in explanted rat livers. Deuterium oxide (2 H2O) was used as a source of 2 H. A total of 10-80% v/v 2 H2O was added to homogenates obtained from a liver biopsy and the formation of 2 H-labeled metabolites was monitored.

RESULTS

Some well-resolved 2 H resonances were found in the homogenates from biopsies of warm ischemic liver. Two of these were identified as [3-2 H] lactate and [2-2 H] lactate, and a linear relationship was found between the ratio of [[2-2 H] lactate] to [[3-2 H] lactate] and the warm ischemia time. The deuterium incorporation into lactate was explained on the basis of the metabolic events occurring under hypoxic conditions.

CONCLUSIONS

The experimental results support the application of 2 H NMR for a reliable evaluation of the metabolic status of a liver harvested from non-heart-beating donors.

Large-scale feasibility of gene transduction into human CD34+ cell-derived dendritic cells by adenoviral/polycation complex

With a view to using multiple injections of anti-cancer dendritic cell (DC)-based vaccines, we evaluated the feasibility of the adenoviral transduction of large amounts of human CD34+ cell-derived DCs, and analysed the persistence of the transgene expression and the integrity of DC functional activity after the transduction/cryopreservation procedures. Mature DCs generated from highly enriched human CD34+ cells were transduced by a recombinant adenovirus (rAd-MFG) that carried a modified, membrane-exposed, alkaline phosphatase (AP) sequence as the reporter gene. Cationic lipids such as LipofectAmine or poly-L-lysine were mixed with the viral particles before the transduction of the target cells. The highest transduction efficiency was obtained at a multiplicity of infection (MOI) rate of 500 (AP + DCs: 50 +/- 2%, viability =95%) under both small- and large-scale conditions. The addition of poly-L-lysine or LipofectAmine increased the percentage of transduced cells at an MOI of 500 (CD1a+/AP+ cells = 85 +/- 3% and 80 +/- 2% respectively). Polycations made it possible to reduce the amounts of viral particles, with high efficiency of transduction being achieved at a MOI of 100 with 10 microg/ml poly-L-lysine (CD1a+/AP+: 68 +/- 9%) or 30 microg/ml LipofectAmine (CD1a+/AP+: 60 +/- 7%). Evaluation of the immunophenotype of the transduced DCs showed that the lack of a DC subpopulation was more susceptible to adenoviral transduction. Cryopreservation of transduced DCs did not modify the viability or percentage of AP+ cells that maintain antigen-presenting cell (APC) functions. These findings indicate the efficacy of this method for the transduction of large amounts of CD34+ cell-derived DCs using small quantities of adenoviral vector mixed with polycations. Cryopreservation of transduced DCs did not damage their viability or APC functions, thus making it possible to plan multiple injections of engineered DC-based vaccines.

Preparation, morphological characterization, and activity of thin films of horseradish peroxidase

Active uniform films of horseradish peroxidase (HRP) have been prepared by covalent binding on Si/SiO(2) or glass supports previously activated by silanization and succinylation. Labeling by fluorescent or by Electron Spin Resonance (ESR) probes was used to quantify the surface density of active groups and of horseradish peroxidase. Atomic Force Microscopy (AFM) imaging was used to characterize the surface morphology. We observed that a non-uniform protein adsorption due to physical interactions was present when the supports were not activated for covalent binding and was, in large part, removed by washing. The enzyme deposited by covalent binding formed homogeneous layers with a height in the range 60-90 A. By using a fluorescent label, we calculated a protein density of 3.6 x 10(12) molecules cm(-2) on Si/SiO(2), corresponding to an estimated area per molecule of 2800 A(2) which is in agreement with the value expected on the basis of the crystallographic data considering the formation of a monomolecular layer. The protein density of the layer immobilized on glass was similar (1.9 x10(12) molecules cm(-2)). The enzyme immobilized on both supports showed a k(cat)/K(M) being of the order of 3-5x10(5) M(-1)s(-1) that is 1/20th of free HRP. The half-life time of the activity of the enzyme immobilized by covalent binding was longer than 40 days at 6 degrees C.

Contribution of proanthocyanidins to the peroxy radical scavenging capacity of some Italian red wines

Highly reactive radicals, ROO(*), were generated from 2, 2'-azobis[2-(2-imidazolin-2-yl)propane] and linoleic acid. The ROO(*) scavenging capacity of some Italian red wines was evaluated following the changes in oxygen consumption. Under the experimental conditions the time course of oxygen consumption shows two typical behaviors: trolox-like (class I) and gallic acid-like (class II). Usually the time course of wine was similar to that of gallic acid. The rate of oxygen consumption was found to decrease exponentially with the amount of wine or gallic acid added to the test solution. On this basis the capacity of red wines to scavenge peroxy radicals was expressed as content of gallic acid (S(GA)). The S(GA) values were found to be correlated to the amount of total proanthocyanidins and total polyphenols of some Italian red wines (p < 0.01). The proanthocyanidins extracted from seeds were shown to make a major contribution to the peroxy radical scavenging capacity of red wines, whereas, interestingly, the chemical class of the low molecular weight tannins reactive to vanillin did not correlate with the S(GA) values.