Safety-related properties of staphylococci isolated from food and food environments

AIMS

To test some safety-related properties within 321 staphylococci strains isolated from food and food environments.

METHODS AND RESULTS

The isolates were identified as Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Staphylococcus pasteuri, Staphylococcus sciuri, Staphylococcus warneri and Staphylococcus xylosus. Decarboxylase activity was quite common for the various Staphylococcus spp., and tyrosine was the most frequently decarboxylated amino acid. The frequency of antibiotic resistance was highest in Staph. pasteuri and Staph. xylosus. Several of the isolates were tolerant to QAC compounds, and in some cases, QAC tolerance was present in antibiotic-resistant strains. Most of the strains displayed moderate to high adhesion rates to stainless steel and Teflon(®). The strains that readily formed biofilms belonged to the species Staph. aureus, Staph. epidermidis and Staph. pasteuri.

CONCLUSIONS

An high incidence of some safety hazards was found within the staphylococcal strains of food origin tested in this study. In particular, amino acid decarboxylase activity and biofilm-forming ability were common within strains, and antibiotic resistance and tolerance to QAC-based compounds occurred frequently as well. These characteristics are an important safety concern for food industry.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work gives a first picture of safety hazards within staphylococcal species isolated from food environments. The presence of disinfectant-resistant staphylococci is a concern because resistance can be genetically transferred between the various Staphylococcus species. This could lead an increase and spread of resistant enterotoxic staphylococci and/or pathogenic staphylococci.

Predictive factors of lack of response to antiviral therapy among in patients with recurrent hepatitis C after liver transplantation

The current therapy for hepatitis C recurrence after liver transplantation OLT is based on interferon (IFN) and ribavirin (RBV) in monotherapy or combination. The rate of sustained virological response (SVR) varies between 10% and 45%. We have retrospectively analyzed factors that could predict SVR after antiviral therapy. We analyzed 42 patients who completed a cycle of therapy with natural or pegylated IFN plus RBV. There were 15 (35.7%) patients who obtained an SVR. The following factors were significantly associated with a lack of SVR: donor age >or=50 years (P = .046); donor body mass index (BMI) > 27 (P = .016); genotype 1 versus 2 to 3 (P = 0.010), aspartate transferase (AST) before therapy >or= 140 U/L (P = .046), alanine transferase before therapy >or= 280 U/L (P = .055), use of natural IFN versus pegylated IFN (P = .016). The only factors remaining after multivariate analysis were: donor BMI, AST before therapy and genotype. Our data confirmed that genotype 1 was associated with poorer outcomes; other additional parameters can influence the response to antiviral therapy.

Preliminary results of phase II study of capecitabine and gemcitabine (CAP-GEM) in patients with metastatic pretreated thymic epithelial tumors (TETs)

BACKGROUND

No previous prospective trials have been reported with capecitabine and gemcitabine (CAP-GEM) in patients with metastatic thymic epithelial tumors (TETs). We conducted a multicenter study to determine the activity and tolerability of this regimen in pretreated TETs.

PATIENTS AND METHODS

A total of 15 patients were enrolled in the first stage of phase II study. All patients received CAP-GEM every 3 weeks. The primary end point was objective response rate (RR); secondary end points were toxicity, progression-free survival (PFS) and overall survival.

RESULTS

Complete responses (CR) and partial responses were observed in three (20%) and three (20%) patients for a 40% RR, respectively. Grade 1-2 neutropenia, anemia and thrombocytopenia were the most common side-effects, noted in seven (46.7%), five (33.3%) and five (33.3%) patients, respectively. The most common grade 3 toxicity was neutropenia in three patients (20%). Median PFS was 11 months (95% confidence interval 4-17). The 1- and 2-year survival rates were 80% and 67%, respectively.

CONCLUSION

We have decided to publish the preliminary results because this regimen was more active than that expected. Although our results are preliminary, CAP-GEM shows activity and safety in pretreated TETs. Furthermore, multicenter trials, also in first-line setting, are necessary to confirm our results.

Pharmacokinetics and linear exposure of AFRESA compared with the subcutaneous injection of regular human insulin

AIM

AFRESA [Technosphere Insulin (TI); MannKind Corporation, Valencia, CA], a dry powder preparation of regular human insulin (RHI), utilizes a novel and versatile drug carrier platform that enables pulmonary administration of medications typically administered by injection. The aim of this study was to compare the pharmacokinetic (PK) and pharmacodynamic (PD) parameters of three different inhaled doses of TI with those of subcutaneous (s.c.) RHI.

METHODS

This randomized, open-label, four-way crossover study of 11 healthy, non-smoking volunteers evaluated PK and PD profiles following single inhalations of 25, 50 or 100 U TI and 10 IU RHI administered subcutaneously using a euglycaemic clamp technique.

RESULTS

Following inhalation of TI, peak insulin concentrations (C(max)) were achieved approximately 2 h earlier than with RHI (12-17 min for TI vs. 134 min for RHI). Area under the insulin concentration-time curve (AUC) and insulin C(max) values increased with increasing TI dose. Insulin exposure, as measured by AUC, was found to be linear over the dose range studied. Compared with s.c. RHI, TI at doses of 25, 50 and 100 U showed a relative bioavailability of 25, 23 and 21%, respectively. The maximum bioeffect, as measured by the glucose infusion rate, occurred approximately 2 h earlier for all three TI doses (42, 50 and 58 min, respectively) than for s.c. RHI (171 min). No treatment-related adverse events were reported with TI.

CONCLUSION

TI is an inhaled insulin with a more rapid absorption and a more rapid elimination than subcutaneously administered RHI, resulting in a quick onset and short duration of action. Insulin exposure following TI administration was found to be linear over the dose range of 25-100 U.

Gemcitabine-capecitabine in platinum-refractory patients with thymic epithelial tumors

7590

Background: Platinum based combination chemotherapy is the actual standard of care for advanced and recurrent Thymic epithelial tumours-TET (thymoma and thymic carcinoma). Additional agents are needed in this setting. We have designed a pilot study, phase II multicenter, to evaluate the efficacy and safety of no tested schedule gemcitabine-capecitabine in patients refractory to platinum based chemotherapy. Methods: Eligible patients had pathologically confirmed TET and were treated with at least 2 lines of chemotherapy, one of this being a platinum based schedule. From January 2007 to September 2008 twelve pts were enrolled. Treatment Schedule: Gemcitabine 1,000 mg/m2 by 30-minute infusion on days 1 and 8 every 3 weeks plus oral capecitabine 650 mg/m2 twice daily on days 1 to 14. Response was evaluated at 3 and 6 cycles. Results: Pts Characteristics: 12 pts (7 M-5F, Median Age 51,3 yrs,range 27–76). 7 pts had received Thymectomy and 4 of this had received also surgery for metastatic disease. 5 pts have received only thymic biopsy. Performance status sec. Karnofsky was 90% (range 80–100). Site of disease: liver, lung, bone, nodal, pleural and pericardium. All pts were staged IVB sec. Masaoka. Tumors were classified by WHO classification as follows: 4-B2, 8-B2/B3. All pts were evaluated as concerns performance status and all had Karnofcky 90% (range 80–100). Sites of metastatic disease were: liver,lung,bone,nodal, pleural and pericardium. Associated paraneoplastic syndromes were: myasthenia in 7 pts, B-lymphopenia 11 pts. The minimum number of cycles administered on study was 3 (range 3–8).Among the 12 enrolled pts there were 10 objective response: 2 CR, 8 PR. 2 pts had SD. Prolonged maintenance of absence of disease was obtained in the 2 pts reporting a CR (more than 6 months in 1 patient). Treatment was well tolerated, no grade 4 toxicities was registered. Conclusions: The combination schedule gemcitabine-capecitabine have an high activity in Thymic malignancies in pts heavily pretreated with advanced recurrent TET and appears to be a safe option in platinum-refractory TET pts. This schedule must be proposed to be used also in randomized clinical trial compared with platinum based treatment.

No significant financial relationships to disclose.

Effect of bisphenol A with or without enzyme treatment on the proliferation and viability of MCF-7 cells

Recently, aqueous solutions polluted by BPA have been bioremediated by us using laccase immobilized on hydrophobic membranes in non-isothermal bioreactors. BPA degradation was checked using analytical methods. To assess in vitro the occurred bioremediation, the proliferation and viability indexes of MCF-7 cells incubated in the presence of aqueous solutions of BPA, or of enzyme-treated BPA solutions, have been measured as a function of the initial BPA concentration. The results demonstrated that: i) at each initial BPA concentration used, both the proliferation and viability indexes are a function of the duration of enzyme treatment; ii) proliferation and viability are uncoupled biological processes with respect to BPA enzyme treatment. Non-isothermal bioreactors are a useful tool for the bioremediation of aqueous solutions polluted by BPA, which is an example of an endocrine disruptor that belongs to the alkyl phenol family.

Estrogen regulation of adipose tissue functions: involvement of estrogen receptor isoforms

Adipose tissue has recently been described as one of the major endocrine gland that plays a role in energy homeostasis, lipid metabolism, immune response, and reproduction. An excess of white adipose tissue, caused by a complex interaction between genetic, hormonal, behavioral, and environmental factors, results in obesity: a heterogeneous disorder that predisposes humans to a variety of diseases. Among several hormones, estrogens promote, maintain, and control the typical distribution of body fat and adipose tissue metabolism through still unknown mechanisms. These steroids are known to regulate fat mass, adipose deposition and differentiation, and adipocyte metabolism. Moreover, estrogen deficiency results in increases in adipose tissue, preferentially in visceral fat, which would link obesity to the susceptibility of related disorders. In this review the role of estrogens in adipose tissue differentiation and in the protection against the onset of obesity will be discussed with particular attention being drawn to the underlying molecular mechanisms mediated by estrogen receptor isoforms ERalpha and ERbeta.

[Pulmonary alveolar proteinosis: report of two cases and review of the literature]

Pulmonary alveolar proteinosis is a rare disease characterized by extensive radiological and tomographic pulmonary lesions and a variable clinical picture ranging from pulmonary insufficiency to spontaneous remission. Among its three described forms, the so called Idiopathic or Adult form is responsible for more than 80% of published cases. It's physiopathology depends on an autoimmune process directed against the GM-CSF (Granulocite Macrophage- Colony Stimulating Factor) that induces a functional defect of the macrophage with consequent intraalveolar accumulation of surfactant. Pulmonary and extrapulmonary infections, are common, often with unusual pathogens. Diagnosis can be made from the combination of clinical, radiological and bronchoalveolar lavage data, although sometimes histopathologic material is needed for confirmation. Total pulmonary lavage is currently the treatment of choice. Mortality is usually low and related mostly to infectious complications. We hereby describe our experience with two patients.

A mononucleotide markers panel to identify hMLH1/hMSH2 germline mutations

Hereditary NonPolyposis Colorectal Cancer (Lynch syndrome) is an autosomal dominant disease caused by germline mutations in a class of genes deputed to maintain genomic integrity during cell replication, mutations result in a generalized genomic instability, particularly evident at microsatellite loci (Microsatellite Instability, MSI). MSI is present in 85–90% of colorectal cancers that occur in Lynch Syndrome. To standardize the molecular diagnosis of MSI, a panel of 5 microsatellite markers was proposed (known as the “Bethesda panel”). Aim of our study is to evaluate if MSI testing with two mononucleotide markers, such as BAT25 and BAT26, was sufficient to identify patients with hMLH1/hMSH2 germline mutations. We tested 105 tumours for MSI using both the Bethesda markers and the two mononucleotide markers BAT25 and BAT26. Moreover, immunohistochemical evaluation of MLH1 and MSH2 proteins was executed on the tumours with at least one unstable microsatellite, whereas germline hMLH1/hMSH2 mutations were searched for all cases showing two or more unstable microsatellites.

The Bethesda panel detected more MSI(+) tumors than the mononucleotide panel (49.5% and 28.6%, respectively). However, the mononucleotide panel was more efficient to detect MSI(+) tumours with lack of expression of Mismatch Repair proteins (93% vs 54%). Germline mutations were detected in almost all patients whose tumours showed MSI and no expression of MLH1/MSH2 proteins. No germline mutations were found in patients with MSI(+) tumour defined only through dinucleotide markers. In conclusion, the proposed mononucleotide markers panel seems to have a higher predictive value to identify hMLH1 and hMSH2 mutation-positive patients with Lynch syndrome. Moreover, this panel showed increased specificity, thus improving the cost/effectiveness ratio of the biomolecular analyses.

Expression of autoimmune regulator gene (AIRE) and T regulatory cells in human thymomas

Expression of the autoimmune regulator gene (AIRE) and the presence of CD25(+)/forkhead box p3 (FoxP3)(+) T regulatory (T(reg)) cells were investigated in histologically normal adult thymi and in thymomas using immunohistochemistry and quantitative real-time polymerase chain reaction (PCR). In the normal thymus staining for AIRE was detected in the nucleus of some epithelial-like cells located in the medulla; in thymomas AIRE-positive cells were extremely rare and could be detected only in the areas of medullary differentiation of two B1 type, organoid thymomas. RNA was extracted from 36 cases of thymoma and 21 non-neoplastic thymi obtained from 11 myasthenic (MG(+)) and 10 non-myasthenic (MG(-)) patients. It was found that AIRE is 8.5-fold more expressed in non-neoplastic thymi than in thymomas (P = 0.01), and that the amount of AIRE transcripts present in the thymoma tissue are not influenced by the association with MG, nor by the histological type. A possible involvement of AIRE in the development of MG was suggested by the observation that medullary thymic epithelial cells isolated from AIRE-deficient mice contain low levels of RNA transcripts for CHRNA 1, a gene coding for acetylcholine receptor. Expression of human CHRNA 1 RNA was investigated in 34 human thymomas obtained from 20 MG(-) patients and 14 MG(+) patients. No significant difference was found in the two groups (thymoma MG(+), CHRNA1 = 0.013 +/- 0.03; thymoma MG-, CHRNA1 = 0.01 +/- 0.03). In normal and hyperplastic thymi CD25(+)/Foxp3(+) cells were located mainly in the medulla, and their number was not influenced by the presence of MG. Foxp3(+) and CD25(+) cells were significantly less numerous in thymomas. A quantitative estimate of T(reg) cells revealed that the levels of Foxp3 RNA detected in non-neoplastic thymi were significantly higher (P = 0.02) than those observed in 31 cases of thymomas. Our findings indicate that the tissue microenvironment of thymomas is defective in the expression of relevant functions that exert a crucial role in the negative selection of autoreactive lymphocytes.

Perinatal hypoxia triggers alterations in K+ channels of adult pulmonary artery smooth muscle cells

Adverse events during the perinatal period, like hypoxia, have been associated with adult diseases. In pulmonary vessels, K(+) channels play an important role in the regulation of vascular tone. In the fetus, Ca(2+)-activated K(+) channels (K(Ca)) are predominant, whereas from birth voltage-gated K(+) channels (K(V)) prevail in the adult. We postulated that perinatal hypoxia could alter this maturational shift and influence regulation of pulmonary vascular tone in relation to K(+) channels in adulthood. We evaluated the effects of perinatal hypoxia on K(V) and K(Ca) channels in the adult main pulmonary artery (PA) using a murine model. Electrophysiological measurements showed a greater outward current in PA smooth muscle cells of mice born in hypoxia than in controls. In controls, only K(V) channels contributed to this current, whereas in mice born in hypoxia both K(V) and K(Ca) channels were implicated. K(V) channel activity was even higher in mice born in hypoxia than in controls. Therefore, perinatal hypoxia results in increased K(Ca) and K(V) channel activity in adult PA. Moreover, PA of adults born in hypoxia displayed higher large-conductance K(Ca) alpha-subunit and K(V)1.5 alpha-subunit protein expression than controls. Interestingly, relaxation induced by nitric oxide (NO) donors [S-nitroso-N-acetyl-D,l-penicillamine, 2-(N,N-diethylamino)-diazenolate-2-oxide] in isolated PA of control mice was not mediated by K(Ca) channels and only slightly by K(V) channels, whereas following perinatal hypoxia both K(Ca) and K(V) channels contributed to this relaxation. Thus perinatal hypoxia results in altered expression and activity of different K(+) channels in the adult main PA, which could contribute to modifications of pulmonary vasoreactivity.