Growth of Listeria monocytogenes in ready-to-eat "shrimp cocktail": Risk assessment and possible preventive interventions.

The present study investigated the presence, growth potential, and public health risk posed by Listeria monocytogenes in a ready-to-eat "shrimp cocktail". The pathogen was detected in 4 out of the 104 samples, and there were no counts above the enumeration limit (1 Log colony-forming unit (CFU)/g); the product was a suitable substrate for pathogen growth owing to its chemical/physical properties. A stochastic quantitative microbial risk assessment (QMRA) was performed to estimate the expected number of invasive listeriosis cases caused by the consumption of 10,000 servings of the product on the last day of its shelf life, considering a population comprising healthy consumers, those susceptible, and transplant recipients. The model predicted no cases for this scenario. Uncertainties were included by considering alternative scenarios; even when considering an increased mean bacterial concentration (up to 3-4 Log CFU/g), no cases were estimated. Following a producer's demand, the exposure assessment model was also used to estimate the probability of the product exceeding the threshold of 2 log CFU/g during the shelf life. The possibility of Listeria growth in the product could not be avoided. Therefore, a modification of the production process was tested to re-classify the product as unsuitable for Listeria growth (EC Reg. 2073/2005). The shrimps were conditioned in three different organic acid solutions comprising: acetic acid (1500 ppm) (A); benzoic acid (1500 ppm) + acetic acid (500 ppm) + lactic acid (750 ppm) (BLA); and lactic acid (4500 ppm) + sodium acetate (2500 ppm) (LSA). Testing was conducted over various treatment durations (1 day-5 days). Treatment for 2 days in the LSA solution was selected based on efficacy, the absence of consumer-perceptible sensorial modifications, and the producers' production rate requirements. The concentration of L. monocytogenes decreased when the new process was applied, which confirmed the usefulness and effectiveness of the treatment relative to the traditional process. Thus, the product obtained by the modified production process did not support the growth of L. monocytogenes.

Kidney Transplantation, Polymorphisms of IL-18, and Other Pro-Inflammatory Genes and Late Post-Transplant Outcome.

BACKGROUND: Functional polymorphisms of molecules involved in immune-mediated mechanisms of allograft rejection could be predictive of increased risk for early and late post-transplant complications. In the past years, the challenge for long-term graft survival in kidney recipients is the implementation of personalized approaches. In this study, effects of interleukin (IL)-18-137G/C (rs187238), -607C/A (rs1946518), and other pro-inflammatory cytokine gene polymorphisms (tumor necrosis factor [TNF]-α-308G/A, rs1800629, IL-6-174G/C, rs1800795, and interferon [IFN]-γ+874A/T, rs2430561) on the main post-transplant risk parameters and diseases (metabolic, cardiovascular, infective, and chronic allograft rejection) were assessed in kidney-transplanted patients. METHODS: One hundred seventy-nine transplanted patients were retrospectively analyzed for clinical and biochemical parameters and onset of post-transplant complications. Taqman allelic discrimination and PCR-SSP (polymerase chain reaction-sequence specific primers) techniques were used for genotyping. RESULTS: No predictive effects of allele and genotypes of IL-18-607C/A, TNF-α-308G/A, IL-6-174G/C, and IFN-γ+874A/T gene polymorphisms and onset of risk factors and late complications were evidenced. However, Kaplan-Meier analysis evidenced a weak effect of IL-18-137G/C genotypes on graft survival. CONCLUSIONS: Analyzing associations between some pro-inflammatory cytokine gene polymorphisms and onset of the most relevant risk factors and late complications of kidney transplant, results suggested a possible impact of IL-18-137G/C genotypes on graft survival, which deserves further studies.

Cerebrospinal fluid ATP metabolites in multiple sclerosis.

Increased axonal energy demand and mitochondrial failure have been suggested as possible causes for axonal degeneration and disability in multiple sclerosis. Our objective was to test whether ATP depletion precedes clinical, imaging and biomarker evidence for axonal degeneration in multiple sclerosis. The method consisted of a longitudinal study which included 21 patients with multiple sclerosis. High performance liquid chromatography was used to quantify biomarkers of the ATP metabolism (oxypurines and purines) from the cerebrospinal fluid at baseline. The Expanded Disability Status Scale, MRI brain imaging measures for brain atrophy (ventricular and parenchymal fractions), and cerebrospinal fluid biomarkers for axonal damage (phosphorylated and hyperphosphorylated neurofilaments) were quantified at baseline and 3-year follow-up. Central ATP depletion (sum of ATP metabolites >19.7 micromol/litre) was followed by more severe progression of disability if compared to normal ATP metabolites (median 1.5 versus 0, p< 0.05). Baseline ATP metabolite levels correlated with change of Expanded Disability Status Scale in the pooled cohort (r= 0.66, p= 0.001) and subgroups (relapsing-remitting patients: r= 0.79, p< 0.05 and secondary progressive/primary progressive patients: r= 0.69, p< 0.01). There was no relationship between central ATP metabolites and either biomarker or MRI evidence for axonal degeneration. The data suggests that an increased energy demand in multiple sclerosis may cause a quantifiable degree of central ATP depletion. We speculate that the observed clinical disability may be related to depolarisation associated conduction block.

Cellular and molecular effects of protons: apoptosis induction and potential implications for cancer therapy.

Due to their ballistic precision, apoptosis induction by protons could be a strategy to specifically eliminate neoplastic cells. To characterize the cellular and molecular effects of these hadrons, we performed dose-response and time-course experiments by exposing different cell lines (PC3, Ca301D, MCF7) to increasing doses of protons and examining them with FACS, RT-PCR, and electron spin resonance (ESR). Irradiation with a dose of 10 Gy of a 26,7 Mev proton beam altered cell structures such as membranes, caused DNA double strand breaks, and significantly increased intracellular levels of hydroxyl ions, are active oxygen species (ROS). This modified the transcriptome of irradiated cells, activated the mitochondrial (intrinsic) pathway of apoptosis, and resulted in cycle arrest at the G2/M boundary. The number of necrotic cells within the irradiated cell population did not significantly increase with respect to the controls. The effects of irradiation with 20 Gy were qualitatively as well as quantitatively similar, but exposure to 40 Gy caused massive necrosis. Similar experiments with photons demonstrated that they induce apoptosis in a significantly lower number of cells and in a temporally delayed manner. These data advance our knowledge on the cellular and molecular effects of proton irradiation and could be useful for improving current hadrontherapy protocols.

Community acquired pneumonia in internal medicine: a one-year retrospective study based on pneumonia severity index.

Community acquired pneumonia (CAP) represents the sixth cause of death and the first cause of death for an infectious disease in the USA. The aim of the present study is to evaluate how CAP is managed in a hospital setting, with particular attention to the wards of internal medicine, compared to the recommendations based and validated PSI (Pneumonia Severity Index). 42 subjects were included in the study, 25 males and 17 females. According to the PSI, nine (21%) patients were classified in class I, two (5%) in class II, ten (24%) in class III, fifteen (36%) in class IV and six (14%) in class V. Three patients died during the stay in the hospital (2 males and 1 female), all in the highest PSI class (V). According to the criteria used to evaluate the adequacy of the admission to the hospital, twentyeight patients were classified in the HRG, with an appropriate admission, whilst fourteen (33%) were in the LRG, with an inappropriate admission to the hospital. The data of the study confirm the validity of a PSI based strategy for the management of CAP since admittance to the hospital. This approach is not yet widely implemented in Italy, and a better dialogue between hospital and health system representatives would be convenient, to reduce costs and ensure the safety of patients affected by CAP.

AntiClustal: Multiple Sequence Alignment by antipole clustering and linear approximate 1-median computation.

In this paper we present a new Multiple Sequence Alignment (MSA) algorithm called AntiClusAl. The method makes use of the commonly use idea of aligning homologous sequences belonging to classes generated by some clustering algorithm, and then continue the alignment process ina bottom-up way along a suitable tree structure. The final result is then read at the root of the tree. Multiple sequence alignment in each cluster makes use of the progressive alignment with the 1-median (center) of the cluster. The 1-median of set S of sequences is the element of S which minimizes the average distance from any other sequence in S. Its exact computation requires quadratic time. The basic idea of our proposed algorithm is to make use of a simple and natural algorithmic technique based on randomized tournaments which has been successfully applied to large size search problems in general metric spaces. In particular a clustering algorithm called Antipole tree and an approximate linear 1-median computation are used. Our algorithm compared with Clustal W, a widely used tool to MSA, shows a better running time results with fully comparable alignment quality. A successful biological application showing high aminoacid conservation during evolution of Xenopus laevis SOD2 is also cited.

Bronchial hyperresponsiveness in adults with seasonal and perennial rhinitis: is there a link for asthma and rhinitis?

Epidemiological studies have shown that asthma and rhinitis often coexist in the same patients and the prevalence of asthma is greater in patients with rhinitis. The aim of this study was to evaluate the differences in bronchial reactivity in subjects with seasonal and perennial rhinitis. We enrolled 128 subjects with seasonal or perennial allergic rhinitis divided into three groups: A with perennial rhinitis and allergy to Dermatophagoides Pteronissynus; B with seasonal rhinitis and allergy to Graminae and Parietaria, who underwent methacholine challenge test (MCHt) during the exposure period (fron March until May); C with seasonal rhinitis and allergy to Graminae and Parietaria, who underwent MCHt during the non exposure period (from June until February). The PC20 mean values of group A (1774.8 ± 20.7) and group B (1740.7 ± 38.8) were not significantly different, but significantly lower than those of group C (3010.0 ± 56.9) (p=0.001). The subjects with group A were positive to the MCHt in 54.54%, against 29.28% of group B and 11.62% of group C (p=0.007). The results show differences in the degree of bronchial responsiveness. The dose-response curves documented a lower value of PC20 in the group with perennial rhinitis and a statistically significant difference of bronchial hyperresponsiveness prevalence between the three groups (p=0.007).