Lipid nanocapsules: a new platform for nanomedicine

Nanomedicine, an emerging new field created by the fusion of nanotechnology and medicine, is one of the most promising pathways for the development of effective targeted therapies with oncology being the earlier and the most notable beneficiary to date. Indeed, drug-loaded nanoparticles provide an ideal solution to overcome the low selectivity of the anticancer drugs towards the cancer cells in regards to normal cells and the induced severe side-effects, thanks to their passive and/or active targeting to cancer tissues. Liposome-based systems encapsulating drugs are already used in some cancer therapies (e.g. Myocet, Daunoxome, Doxil). But liposomes have some important drawbacks: they have a low capacity to encapsulate lipophilic drugs (even though it exists), they are manufactured through processes involving organic solvents, and they are leaky, unstable in biological fluids and more generally in aqueous solutions for being commercialized as such. We have developed new nano-cargos, the lipid nanocapsules, with sizes below the endothelium fenestration (phi<100 nm), that solve these disadvantages. They are prepared according to a solvent-free process and they are stable for at least one year in suspension ready for injection, which should reduce considerably the cost and convenience for treatment. Moreover, these new nano-cargos have the ability to encapsulate efficiently lipophilic drugs, offering a pharmaceutical solution for their intravenous administration. The lipid nanocapsules (LNCs) have been prepared according to an original method based on a phase-inversion temperature process recently developed and patented. Their structure is a hybrid between polymeric nanocapsules and liposomes because of their oily core which is surrounded by a tensioactive rigid membrane. They have a lipoprotein-like structure. Their size can be adjusted below 100 nm with a narrow distribution. Importantly, these properties confer great stability to the structure (physical stability>18 months). Blank or drug-loaded LNCs can be prepared, with or without PEG (polyethyleneglycol)ylation that is a key parameter that affects the vascular residence time of the nano-cargos. Other hydrophilic tails can also be grafted. Different anticancer drugs (paclitaxel, docetaxel, etoposide, hydroxytamoxifen, doxorubicin, etc.) have been encapsulated. They all are released according to a sustained pattern. Preclinical studies on cell cultures and animal models of tumors have been performed, showing promising results.

Evaluation of pegylated lipid nanocapsules versus complement system activation and macrophage uptake

This work consisted in defining the in vitro behavior of pegylated lipid nanocapsules (LNC) toward the immune system. LNC were composed of an oily core surrounded by a shell of lecithin and polyethylene glycol (PEG) known to decrease the recognition of nanoparticles by the immune system. The "stealth" properties were evaluated by measuring complement activation (CH50 technique and crossed-immunoelectrophoresis (C3 cleavage)) and macrophage uptake. These experiments were performed on 20-, 50-, and 100-nm LNC before and after dialysis. A high density of PEG at the surface led to very low complement activation by LNC with a slight effect of size. This size effect, associated to a dialysis effect in macrophage uptake, was due to differences in density and flexibility of PEG chains related to LNC curvature radius. Thanks to a high density, 660-Da PEG provided LNC a steric stabilization and a protective effect versus complement protein opsonization, but this protection decreased with the increase of LNC size, especially versus macrophage uptake.

Random amplified polymorphic DNA assay is less discriminant than pulsed-field gel electrophoresis for typing strains of methicillin-resistant Staphylococcus aureus

Twenty-six strains of methicillin-resistant Staphylococcus aureus with different pulsed-field gel electrophoresis fingerprints were tested by random amplified polymorphic DNA assay with three primers, resulting in 15 to 20 different random amplified polymorphic DNA fingerprints. By summing the results for the three primers, the number of different fingerprints increased to 25, but two strains could not be differentiated. We conclude that pulsed-field gel electrophoresis remains the best method of typing methicillin-resistant S. aureus strains.

High frequency of beta-catenin heterozygous mutations in extra-abdominal fibromatosis: a potential molecular tool for disease management

Background:

Fibromatosis comprises distinct clinical entities, including sporadic extra-abdominal fibromatosis, which have a high tendency for recurrence, even after adequate resection. There are no known molecular biomarkers of local recurrence. We searched for β-catenin mutations in a European multicentre series of fibromatosis tumours to relate β-catenin mutational status to disease outcome.

Methods:

Direct sequencing of exon 3 β-catenin gene was performed for 155 frozen fibromatosis tissues from all topographies. Correlation of outcome with mutation rate and type was performed on the extra-abdominal fibromatosis group (101 patients).

Results:

Mutations of β-catenin were detected in 83% of all cases. Among 101 extra-abdominal fibromatosis, similar mutation rates (87%) were observed, namely T41A (39.5%), S45P (9%), S45F (36.5%), and deletion (2%). None of the clinico-pathological parameters were found to be significantly associated with β-catenin mutational status. With a median follow-up of 62 months, 51 patients relapsed. Five-year recurrence-free survival was significantly worse in β-catenin-mutated tumours regardless of a specific genotype, compared with wild-type tumours (49 vs 75%, respectively, P=0.02).

Conclusion:

A high frequency (87%) of β-catenin mutation hallmarks extra-abdominal fibromatosis from a large multicentric retrospective study. Moreover, wild-type β-catenin seems to be an interesting prognostic marker that might be useful in the therapeutic management of extra-abdominal fibromatosis.

Serum is more suitable than whole blood for diagnosis of systemic candidiasis by nested PCR

PCR assays for the diagnosis of systemic candidiasis can be performed either on serum or on whole blood, but results obtained with the two kinds of samples have never been formally compared. Thus we designed a nested PCR assay in which five specific inner pairs of primers were used to amplify specific targets on the rRNA genes of Candida albicans, C. tropicalis, C. parapsilosis, C. krusei, and C. glabrata. In vitro, the lower limit of detection of each nested PCR assay was 1 fg of purified DNA from the corresponding Candida species. In rabbits with candidemia of 120 minutes' duration following intravenous (i.v.) injection of 10(8) CFU of C. albicans, the sensitivities of the PCR in serum and whole blood were not significantly different (93 versus 86%). In other rabbits, injected with only 10(5) CFU of C. albicans, detection of candidemia by culture was possible for only 1 min, whereas DNA could be detected by PCR in whole blood and in serum for 15 and 150 min, respectively. PCR was more often positive in serum than in whole blood in 40 culture-negative samples (27 versus 7%; P < 0.05%). Lastly, experiments with rabbits injected i.v. with 20 or 200 microgram of purified C. albicans DNA showed that PCRs were positive in serum from 30 to at least 120 min after injection, suggesting that the clearance of free DNA is slow. These results suggest that serum is the sample of choice, which should be used preferentially over whole blood for the diagnosis of systemic candidiasis by PCR.

Phase I trial of recombinant adenovirus gene transfer in lung cancer. Longitudinal study of the immune responses to transgene and viral products

Animal studies indicate that the use of replication-deficient adenovirus for human gene therapy is limited by host antivector immune responses that result in transient recombinant protein expression and blocking of gene transfer when rechallenged. Therefore, we have examined immune responses to an adenoviral vector and to the beta-galactosidase protein in four patients with lung cancer given a single intratumor injection of 10(9) plaque-forming units of recombinant adenovirus. The beta-galactosidase protein was expressed in day-8 tumor biopsies from all patients at variable levels. Recombinant virus DNA was detected by PCR in day-30 and day-60 tumor biopsies from all patients except patient 1. A high level of neutralizing antiadenovirus antibodies was detected in patient 1 before Ad-beta-gal injection whereas it was low (patient 3) or undetectable in the other two patients. All patients developed potent CD4 type 1 helper T cell (Th1) responses to adenoviral particles which increased gradually over time after injection. Antiadenovirus cytotoxic T lymphocyte responses were consistently boosted in the two patients examined (patients 3 and 4). Sustained production of anti-beta-galactosidase IgG was observed in all patients except patient 1. Consistent with anti-beta-gal antibody production, all patients except patient 1 developed intense, dose-dependent Th1 responses to soluble beta-galactosidase which increased over time. Strong beta-galactosidase-specific cytotoxic T lymphocyte responses were detected in patients 2, 3, and 4. Our results clearly show that despite the intensity of antiadenovirus responses, transgene protein expression was sufficient to induce strong and prolonged immunity in three patients. Recombinant adenovirus injected directly into the tumor is a highly efficient vector for immunizing patients against the transgene protein.

Phase I study of a recombinant adenovirus-mediated gene transfer in lung cancer patients

BACKGROUND

Despite vigorous efforts at curbing tobacco consumption and aggressive combined-modality treatment programs, both the incidence of and the mortality from lung cancer have remained virtually unchanged in the last 10 years. More effective innovative therapies are clearly needed. The direct transfer into tumor cells of tumor suppressor genes or toxic gene products that specifically promote tumor cell death and spare nonmalignant cells is a potentially novel anticancer treatment approach that should be investigated.

PURPOSE

On the basis of compelling preclinical data, we initiated a phase I study involving six patients with inoperable lung cancer and an endobronchial lesion accessible by bronchoscopy. Our purpose was to evaluate the feasibility, tolerance, and clinical, biologic, and immunologic effects of the intratumoral administration of a recombinant, replication-deficient adenovirus (rAd.RSV beta-gal), using the Rous sarcoma virus promoter to drive transcription of the Escherichia coli lacZ marker gene that encodes for the bacterial enzyme beta-galactosidase (beta-gal).

METHODS

From June 1994 through April 1995, six patients (five males and one female) were enrolled in the trial. A single dose of recombinant virus suspension containing 10(7) or 10(8) plaque-forming units (PFU) was injected intratumorally into two successive cohorts of three patients. Eligible patients received concomitant chemotherapy. Patients were kept under isolation conditions from 3 days before the injection was given until virus excretion was undetectable. Biopsy specimens of the tumor and surrounding mucosa were collected on the 8th day and at 1, 2, and 3 months after injection. They were analyzed by cell culture, polymerase chain reaction (PCR), and beta-gal expression for the presence of recombinant adenovirus. So that the risk of virus recombination or complementation could be minimized, wildtype adenovirus carriers among the hospital staff (identified by PCR) were excluded from contact with patients who were potentially excreting recombinant virus.

RESULTS

beta-gal was expressed in tumor biopsy specimens of three patients (one who received the 10(7) PFU dose level and two who received 10(8)). Bronchoalveolar lavage specimens collected immediately after injection were positive for recombinant adenovirus when analyzed in culture and by PCR. All biologic fluids were negative for recombinant virus as judged by PCR after day 12, with the exception of bronchoalveolar lavage specimens (positive PCR up to 90 days in two of three patients treated with 10(8) PFU). The blood samples obtained from the three patients treated with 10(8) PFU showed positive PCR results immediately after virus injection. Patients were kept in isolation for a median of 17 days. The most common toxic effects were moderate bleeding (occurring in two patients) during bronchoscopy and fever (seen in four patients). Endoscopic and clinically objective antitumor responses were seen in four patients, including one patient who showed a complete response by pathologic evaluation. The median survival for the patients was 12.5 months (range, 3-16+ months). Throughout the study, hospital staff remained negative for recombinant adenovirus infection.

CONCLUSIONS

This ongoing phase I study has demonstrated that a recombinant adenovirus-mediated marker gene, such as rAd.RSV beta-gal, can be safely introduced into humans and that the gene product is expressed by lung tumor cells of the host.

Bcl-2 and CCND1/CDK4 expression levels predict the cellular effects of mTOR inhibitors in human ovarian carcinoma

Molecular markers enabling the prediction of sensitivity/resistance to rapamycin may facilitate further clinical development of rapamycin and its derivatives as anticancer agents. In this study, several human ovarian cancer cell lines (IGROV1, OVCAR-3, A2780, SK-OV-3) were evaluated for susceptibility to rapamycin-mediated growth inhibition. The differential expression profiles of genes coding for proteins known to be involved in the mTOR signaling pathway, cell cycle control and apoptosis were studied before and after drug exposure by RT-PCR. In cells exposed to rapamycin, we observed a dose-dependent downregulation of CCND1 (cyclin D1) and CDK4 gene expression and late G1 cell cycle arrest. Among these cell lines, SK-OV-3 cells resistant to both rapamycin and RAD001 were the sole to show the expression of the anti-apoptotic gene Bcl-2. Bcl-2/bclxL-specific antisense oligonucleotides restored the sensitivity of SK-OV-3 cells to apoptosis induction by rapamycin and RAD001. These results indicate that baseline Bcl-2 expression and therapy-induced downexpression of CCND1 and CDK4 may be regarded as molecular markers enabling the prediction and follow-up of the cellular effects on cell cycle and apoptosis induction of rapamycin in ovarian cancer. Furthermore, strategies to down regulate Bcl-2 in ovarian cancer may prove useful in combination with rapamycin or RAD001 for ovarian cancer.

Relationship between obesity and severe COVID-19 outcomes in patients with type 2 diabetes: Results from the CORONADO study

AIM

To assess the relationship between body mass index (BMI) classes and early COVID-19 prognosis in inpatients with type 2 diabetes (T2D).

METHODS

From the CORONAvirus-SARS-CoV-2 and Diabetes Outcomes (CORONADO) study, we conducted an analysis in patients with T2D categorized by four BMI subgroups according to the World Health Organization classification. Clinical characteristics and COVID-19-related outcomes (i.e. intubation for mechanical ventilation [IMV], death and discharge by day 7 [D7]) were analysed according to BMI status.

RESULTS

Among 1965 patients with T2D, 434 (22.1%) normal weight (18.5-24.9 kg/m² , reference group), 726 (36.9%) overweight (25-29.9 kg/m² ) and 805 (41.0%) obese subjects were analysed, including 491 (25.0%) with class I obesity (30-34.9 kg/m² ) and 314 (16.0%) with class II/III obesity (≥35 kg/m² ). In a multivariable-adjusted model, the primary outcome (i.e. IMV and/or death by D7) was significantly associated with overweight (OR 1.65 [1.05-2.59]), class I (OR 1.93 [1.19-3.14]) and class II/III obesity (OR 1.98 [1.11-3.52]). After multivariable adjustment, primary outcome by D7 was significantly associated with obesity in patients aged younger than 75 years, while such an association was no longer found in those aged older than 75 years.

CONCLUSIONS

Overweight and obesity are associated with poor early prognosis in patients with T2D hospitalized for COVID-19. Importantly, the deleterious impact of obesity on COVID-19 prognosis was no longer observed in the elderly, highlighting the need for specific management in this population.

Pharmacologically active microcarriers: a tool for cell therapy

To overcome certain problems encountered in cell therapy, particularly cell survival, lack of cell differentiation and integration in the host tissue, we developed pharmacologically active microcarriers (PAM). These biodegradable particles made with poly(D,L-lactic-co-glycolic acid) (PLGA) and coated with adhesion molecules may serve as a support for cell culture and may be used as cell carriers presenting a controlled delivery of active protein. They can thus support the survival and differentiation of the transported cells as well as their microenvironment. To develop this tool, nerve growth factor (NGF)-releasing PAM, conveying PC12 cells, were produced and characterized. Indeed, these cells have the ability to differentiate into sympathetic-like neurons after adhering to a substrate, in the presence of NGF, and can then release large amounts of dopamine. Certain parameters such as the size of the microcarriers, the conditions enabling the coating of the microparticles and the subsequent adhesion of cells were thus studied to produce optimized PAM.

Psychosocial determinants of burnout in geriatric nursing

The purpose of this study was to identify determinants of burnout using an adapted version of Kobasa's theoretical framework, considering work stressors, work support, coping strategies and hardiness. Data were collected through a questionnaire mailed to 1990 randomly selected geriatric nurses. A participation rate of 77.6% was achieved. T-test, variance analysis and multiple regression analysis were conducted. Hierarchical multiple regression analysis indicated that 49% of the variance was explained by the study variables. Hardiness and work stressors were the most important predictors of burnout. The findings are discussed in relation to Kobasa's framework, focusing on resources that reduce negative effects of geriatric work stressors. Implications for nursing practice, management, education and research are proposed.

Random amplified polymorphic DNA typing versus pulsed-field gel electrophoresis for epidemiological typing of vancomycin-resistant enterococci

Sixty vancomycin-resistant vanA mutant Enterococcus faecium (VRE) isolates, collected during a 40-month period from 48 patients hospitalized in a French Cancer Referral Center, were typed by using random amplified polymorphic DNA (RAPD), and the results were compared with those previously obtained by typing with SmaI pulsed-field gel electrophoresis (PFGE), which is currently recognized as the "gold standard." The discriminating power of RAPD typing, with seven primers and 11 combinations of primers, was tested on 18 strains, and only the most discriminating combination was further tested on the whole collection. We compared the epidemiological usefulness of RAPD typing of 60 clinical VRE isolates with that of SmaI PFGE typing. With primers AP4 and ERIC1R, RAPD generated 30 patterns versus the 36 patterns generated by SmaI PFGE. However, this did not hamper the epidemiologically correct clustering of 15 related strains and the detection of multiple colonization in nine patients. We conclude that this simple RAPD technique is well suited to the epidemiological typing of VRE and the monitoring of its nosocomial spread.

Genetic manipulations of adenovirus type 5 fiber resulting in liver tropism attenuation

The development of genetically modified adenoviral vectors capable of specifically transducing a given cell population requires the addition and functional presentation of particular tropism determinants within the virus capsid, together with the abrogation of the molecular determinants that dictate their natural tropism in vivo. The human adenovirus serotype 5 (Ad5) first attaches to the cell surface following high-affinity binding of the C-terminal knob of the fiber capsid protein to the coxsackie and adenovirus receptor (CAR). Here we have assessed whether genetic shortening of the fiber shaft (virus BS1), or replacing the Ad5 fiber shaft and knob with their Ad3 counterparts (virus DB6), could cripple this interaction in vitro and in vivo. A 10-fold decrease in the binding of the modified capsids to soluble CAR was evidenced, which correlated with a similar reduction of their ability to transduce CAR-positive cells in vitro. The ability of BS1 to interact with cellular integrins was also impaired, suggesting that the penton base and the short-shafted fiber when embedded in the capsid preclude each other from efficiently interacting with their cognate cell surface receptors (CAR and integrins respectively). BS1 and DB6 intravenous injections in mice further supported a profound impairment of the ability of the capsid-modified viruses to transduce the liver as demonstrated by a 10-fold reduction of intracellular viral DNA and transgene expression. Interestingly enough, the host humoral response was also specifically weakened in BS1- and DB6-inoculated animals. Taken together, these observations indicate that (i) fiber shortening and (ii) pseudo-typing of Ad5-based vectors with the shaft and knob from non-CAR-binding serotypes constitute two promising strategies to successfully attenuate their native tropism in vitro and most importantly in vivo.

Squamous cell carcinomas after allogeneic bone marrow transplantation for aplastic anemia: further evidence of a multistep process

BACKGROUND

Secondary solid tumors are rare events occurring in patients who underwent allogeneic marrow transplantation for aplastic anemia and Fanconi's anemia. Human herpes virus 8 (HHV8), Epstein-Barr virus (EBV), and human papillomaviruses (HPV) sequences have been found in squamous cell carcinoma (SCC) occurring in organ transplant recipients. The tumor suppressor gene p53 has been strongly linked to the occurrence of SCC in the nonimmunocompromised population.

PATIENTS AND METHODS

In eight patients with SCC, we searched for HHV8, EBV, varicella zoster virus, adenovirus, and HPV sequences from DNA extracted from selected areas of SCC. We also looked for p53 expression in those specimens as well as the presence of anti-p53 antibodies in the serum of these patients at the onset of SCC.

RESULTS

In one patient, we found the presence of both HHV8 and EBV sequences, and in another patient we found HPV16 sequences. All five tumors that could be studied disclosed evidence of p53 accumulation, but none of the eight patients had anti-p53 antibodies in the sera.

CONCLUSION

SCC developing in marrow transplant recipients seems to occur via a multistep process. Genetic predisposition may be present, as in patients with Fanconi's anemia. Transplantation-related factors, such as irradiation and chronic graft-versus-host disease, also have a role. In this article, we add two more potent risk factors: p53 alteration(s) and in some cases the presence of oncogenic viruses.

Comparison of ribotyping, pulsed-field gel electrophoresis and random amplified polymorphic DNA for typing Clostridium difficile strains

Clostridium difficile is a Gram-positive sporulating anaerobic bacillus which causes pseudomembranous colitis. Nosocomial acquisition of this bacteria has proved frequent, and epidemiological markers are needed to recognize and control common-source outbreaks. We therefore compared the results of pulsed-field gel electrophoresis (PFGE) after restriction with SmaI or NruI, random-amplified polymorphic DNA (RAPD) using 3 10-mer oligonucleotides, and ribotyping to differentiate between 30 unrelated strains of C. difficile belonging to 8 serotypes. The strains were separated into 26 different types by PFGE, 25 by RAPD, but into only 18 types by ribotyping. Median percentages of similarity between strains ranged from 27 in the PFGE assay to 90 in the ribotyping assay, but there was good agreement between the 3 methods for the clustering of strains. PFGE was more time-consuming than RAPD but its patterns were easier to analyze.

Prevalence of virulence genes and clonality in Escherichia coli strains that cause bacteremia in cancer patients

Phenotypic analysis of Escherichia coli strains causing bacteremia in cancer patients suggests that they possess specific virulence properties. To investigate this hypothesis, we compared the frequency of the virulence-related genes cnf1, cnf2, papC, hlyC, and iut in 155 E. coli strains isolated from hospitalized cancer patients with epidemiologically unrelated cases of bacteremia to their frequency in 70 E. coli strains isolated from the feces of healthy unrelated volunteers. Of the blood isolates, 24, 37, and 26% were positive for cnf1, papC, and hlyC, respectively, versus only 6, 17, and 6% of the fecal isolates (P < 0.05 in all instances). By contrast, 47% of both isolates carried the iut gene. The patients' clinical characteristics did not significantly influence these frequencies. The presence on various pathogenicity islands (PAIs) of a combination of the cnf1, papC, and hlyC genes on the chromosome was strongly suggested by Southern blotting of pulsed-field gel electrophoresis (PFGE) patterns with specific DNA probes. The phylogenetic relatedness among 60 strains carrying three, two, one, or no virulence genes and 6 ECOR strains included as references was determined by neighbor joining, the unweighted pair-group method with arithmetic mean, and Wagner analysis of the randomly amplified polymorphic DNA (RAPD) patterns generated by 11 primers. Identification of a major cluster including 96.4% of the strains carrying the cnf1, papC, and hlyC genes and ECOR subgroup B2 strains suggested that the virulent E. coli strains causing bacteremia in cancer patients are closely related to ECOR B2 strains. The presence in the E. coli population surveyed of a strong linkage disequilibrium, and especially of a highly significant correlation between PFGE and RAPD genetic distances, confirms that clonal propagation has a major impact on the E. coli population structure. Nevertheless, low bootstrap values in the phylogenetic tree suggested that frequent genetic exchange inhibits the individualization of discrete genetic lineages, which are stable on an evolutionary scale.

Development and characterization of solid lipid nanoparticles loaded with magnetite

This paper describes the preparation of colloidal lipid particles containing magnetite from warm emulsions. A two step method was used to obtain the nanoparticles: (i) formulation of a transparent phase by heating a O/W emulsion (aqueous surfactant solution melted with a lipid phase, containing the ethyl oleate and soybean lecithin) in which modified lipophilic magnetite is incorporated, and (ii) preparation of the nanoparticles by dispersing the warm transparent phase in cold water (7 degrees C) under mechanical stirring. The latter method gives spherical nanoparticles of a mean size of 62 nm measured by Photon Correlation Spectroscopy and Transmission Electronic Microscopy. The magnetite entrapment efficiency was determined by use of a magnetophoretic sedimentation method.

Decontamination of polymerase chain reaction reagents for detection of low concentrations of 16S rRNA genes

We describe a polymerase chain reaction (PCR) that allowed detection of rRNA consensus sequences from the DNA extracted from a wide range of bacterial species in amounts as low as 10 fg. To avoid false positive results with universal primers for 16S rRNA PCR, contaminating DNA had to be eliminated from the polymerase preparations. Decontamination was undertaken before PCR to optimize treatment with DNaseI, and was followed by DNase inactivation at 94 degrees C for 50 min, which eliminated contaminating DNA at concentrations of up to 100 pg. After optimization of PCR conditions for each polymerase. Deep Vent Exo-polymerase (New England Biolabs, Beverly, MA), and super-Taq polymerase (HT Biotechnology, Cambridge, UK) were more effective than Ampli-Taq polymerase (Perkin-Elmer Cetus, Norwalk CT), Ampli-Taq LD polymerase (Perkin-Elmer Cetus) or Deep-vent polymerase (New England Biolabs). The technique described in this article might prove to be a universal method for PCR detection of small numbers of unidentified bacteria in usually sterile clinical sites, such as blood and cerebrospinal fluids, in which a broad spectrum of pathogens can be expected.

Quantitative methylation analyses of resection margins predict local recurrences and disease-specific deaths in patients with head and neck squamous cell carcinomas

This study sought to determine whether the presence of hypermethylated genes in the surgical margins can predict local recurrences in head and neck squamous cell carcinomas (HNSCCs). We prospectively collected tumour and surgical margin specimens from patients with HNSCCs who had undergone surgical resections. Quantitative methylation-specific PCR (QMSP) of CDKN2A, CCNA1 and DCC were performed in these specimens and correlated with clinical data. Of the 42 patients eligible for the study, 27 were hypermethylation informative for the above three genes. This latter group was associated with longer disease-free survivals (P=0.007) and longer time to disease-specific deaths (P=0.004). Multivariate analyses confirmed hypermethylation non-informative tumours as an independent prognosticating factor for disease-specific deaths (risk ratio 3.8, P=0.026). Quantitative MSP of the margins of 24 hypermethylation informative tumours revealed that 11 patients had molecularly positive margins, of which, five developed disease-specific events (DSEs, three local recurrences and two metastases), compared to none in patients with molecularly negative margins, after a median follow-up of 48 months. Log-rank analyses showed that molecularly positive margins were associated with shorter time to local recurrences and disease-specific deaths (P=0.03 and 0.01, respectively). This study demonstrated that QMSP of hypermethylated promoters in surgical margins predicted all the local recurrences in our series of HNSCC patients. We have also identified hypermethylation non-informative tumours as an independent predictor for the development of DSEs.

Recombinant adenovirus shedding after intratumoral gene transfer in lung cancer patients

We conducted two phase 1 trials of direct intratumoral injection of a recombinant E1E3-deleted adenovirus (AdR) encoding either the bacterial enzyme beta-galactosidase (Ad.RSVbetagal) or interleukin 2 (IL2, AdTG5327) into primary nonsmall-cell lung cancers of 21 patients. We report here virus shedding and the duration of virus expression in the tumor after intrabronchial injection of 10(7), 10(8) or 10(9) PFU of adenovirus. The infectious AdR and the viral DNA were detected in PBL, plasma, stool and aerodigestive samples in a dose-dependent manner, since cell cultures and PCRs were found to be positive mainly for samples from patients who received the highest AdR dose (10(9) PFU). We detected beta-galactosidase activity in the tumor biopsy samples of 66% of the patients, seemingly dose related, and only low levels of IL2 mRNA could be detected in tumor biopsy samples. E1 sequences were not detected by PCR in any of the PBL and bronchial samples collected after virus delivery, except in one patient. In this patient, E1 sequences were detected in PBL as well as in tumor biopsy samples collected at days 8, 30 and 60 and were correlated with longer beta-galactosidase expression in tumor samples. PBL tested before and after virus delivery contained both E1 sequences indicating that they did not result from replication-competent adenovirus (RCA) E1 sequences present in the inoculum. In addition, only on the day of the injection was Ad.RSVbetagal also detected in E1-positive PBL, indicating that virus replication in blood was very unlikely.

Presence of Clostridium difficile and antibiotic and beta-lactamase activities in feces of volunteers treated with oral cefixime, oral cefpodoxime proxetil, or placebo

Three groups of six healthy adult volunteers were randomly assigned to a treatment with 400 mg of oral cefpodoxime proxetil, oral cefixime, or placebo per day for 10 days. Informed consent was obtained from all volunteers. Clostridium difficile was not detected in the feces of any subject before treatment or at any time in the subjects in the placebo group. C. difficile was, however, detected in all subjects treated with cefpodoxime proxetil and in five of six treated with cefixime. Genomic DNA restriction patterns showed that the strains of C. difficile differed from one volunteer to another. Two subjects both shed different strains at different times during the 25-day surveillance period. All isolates were resistant to cefixime and cefpodoxime (MIC for 90% of strains, 256 and 512 mg/liter, respectively). Antibiotic activity was found in the feces of one volunteer treated with cefpodoxime proxetil and of four volunteers treated with cefixime. It was inversely correlated with the presence of fecal beta-lactamase activity. Intestinal side effects were limited to modifications of stool consistency, which occurred in only 3 of the 12 treated volunteers and did not lead to cessation of treatment. These modifications were significantly associated with the presence of fecal antibiotic activity (P less than 0.05) but not with the shedding of toxigenic or nontoxigenic strains of C. difficile or with the presence of toxin A in feces, which was detected only in one perfectly healthy treated volunteer.

Plant protein-polysaccharide interactions in solutions: application of soft particle analysis and light scattering measurements

The soft particle analysis theory was applied to plant proteins and polysaccharides in solution, to determine the charge density of these polymers and the depth of the layer accessible by counterions according to pH conditions. In addition to the macromolecule shape characterized by light scattering measurements, these properties are also correlated with the optimum coacervation condition, so as to establish the prevalent plant protein-polysaccharide interactions governing the coacervate formation. Globulin was found to be highly charged and spherically shaped. The best coacervation condition was obtained at the pH value, which corresponds to the protein conformation with a dense and compact accessible layer. On the contrary, for the alpha gliadin, bearing a lower charge, a more extended conformation seems to be more favourable. For the plant proteins studied, the coacervation seems to be controlled by the structure of the counter polyanion used: from our model, it turns out that the rod-like structure of arabic gum observed at acidic pH allows the interaction with plant proteins to form coacervates, contrary to the highly charged and spherical structure of alginate.

Detection of genes in feces by booster polymerase chain reaction

A 321-bp fragment intragenic to the gene ereA carried by Escherichia coli BM2195 was used as a model target to study the conditions under which DNA amplification by booster polymerase chain reaction can be used to detect specific bacterial DNA sequences in fecal specimens. When target E. coli cells were mixed with 41 freshly obtained fecal specimens, the polymerase chain reaction detection limit varied from 4.5 to 7.1 log CFU/g of feces, depending on the individual fecal specimen used to prepare the test sample. These variations were not statistically related to the sex or age of the subject from whom the specimen was obtained. After storage of the samples for 4 weeks at room temperature on swabs or filter papers, no loss in sensitivity was observed.