Biofilm producing Salmonella typhi: Chronic colonization and development of gallbladder cancer

Salmonella enterica subspecies enterica serovar Typhi is the aetiological agent of typhoid or enteric fever. In a subset of individuals, S. Typhi colonizes the gallbladder causing an asymptomatic chronic infection. Nonetheless, these asymptomatic carriers provide a reservoir for further spreading of the disease. Epidemiological studies performed in regions where S. Typhi is endemic, revealed that the majority of chronically infected carriers also harbour gallstones, which in turn, have been indicated as a primary predisposing factor for the onset of gallbladder cancer (GC). It is now well recognised, that S. Typhi produces a typhoid toxin with a carcinogenic potential, that induces DNA damage and cell cycle alterations in intoxicated cells. In addition, biofilm production by S. Typhi may represent a key factor for the promotion of a persistent infection in the gallbladder, thus sustaining a chronic local inflammatory response and exposing the epithelium to repeated damage caused by carcinogenic toxins. This review aims to highlight the putative connection between the chronic colonization by highly pathogenic strains of S. Typhi capable of combining biofilm and toxin production and the onset of GC. Considering the high risk of GC associated with the asymptomatic carrier status, the rapid identification and profiling of biofilm production by S. Typhi strains would be key for effective therapeutic management and cancer prevention

How human papillomavirus replication and immune evasion strategies take advantage of the host DNA damage repair machinery

The DNA damage response (DDR) is a complex signalling network activated when DNA is altered by intrinsic or extrinsic agents. DDR plays important roles in genome stability and cell cycle regulation, as well as in tumour transformation. Viruses have evolved successful life cycle strategies in order to ensure a chronic persistence in the host, virtually avoiding systemic sequelae and death. This process promotes the periodic shedding of large amounts of infectious particles to maintain a virus reservoir in individual hosts, while allowing virus spreading within the community. To achieve such a successful lifestyle, the human papilloma virus (HPV) needs to escape the host defence systems. The key to understanding how this is achieved is in the virus replication process that provides by itself an evasion mechanism by inhibiting and delaying the host immune response against the viral infection. Numerous studies have demonstrated that HPV exploits both the ataxia-telangiectasia mutated (ATM) and ataxia-telangiectasia and rad3-related (ATR) DDR pathways to replicate its genome and maintain a persistent infection by downregulating the innate and cell-mediated immunity. This review outlines how HPV interacts with the ATM-and ATR-dependent DDR machinery during the viral life cycle to create an environment favourable to viral replication, and how the interaction with the signal transducers and activators of transcription (STAT) protein family and the deregulation of the Janus kinase (JAK)-STAT pathways may impact the expression of interferon-inducible genes and the innate immune responses

The Emerging Role of Microbial Biofilm in Lyme Neuroborreliosis

Lyme borreliosis (LB) is the most common tick-borne disease caused by the spirochete Borrelia burgdorferi in North America and Borrelia afzelii or Borrelia garinii in Europe and Asia, respectively. The infection affects multiple organ systems, including the skin, joints, and the nervous system. Lyme neuroborreliosis (LNB) is the most dangerous manifestation of Lyme disease, occurring in 10-15% of infected individuals. During the course of the infection, bacteria migrate through the host tissues altering the coagulation and fibrinolysis pathways and the immune response, reaching the central nervous system (CNS) within 2 weeks after the bite of an infected tick. The early treatment with oral antimicrobials is effective in the majority of patients with LNB. Nevertheless, persistent forms of LNB are relatively common, despite targeted antibiotic therapy. It has been observed that the antibiotic resistance and the reoccurrence of Lyme disease are associated with biofilm-like aggregates in B. burgdorferi, B. afzelii, and B. garinii, both in vitro and in vivo, allowing Borrelia spp. to resist to adverse environmental conditions. Indeed, the increased tolerance to antibiotics described in the persisting forms of Borrelia spp., is strongly reminiscent of biofilm growing bacteria, suggesting a possible role of biofilm aggregates in the development of the different manifestations of Lyme disease including LNB

Canine leishmaniasis in Southern Italy: a role for nitric oxide released from activated macrophages in asymptomatic infection?

<p>Abstract</p> <p>Background</p> <p>Human and canine leishmaniasis (CanL) by <it>Leishmania infantum </it>is endemic in Italy, with a high percentage of infected asymptomatic animals. However, the immune response mechanisms underlying the clinical presentation of CanL have not been fully investigated. Among leishmanicidal molecules produced by activated macrophages, nitric oxide (NO) produced by an inducible NO synthase seems to play an important protective role, but no conclusive data are available. Therefore, NO released by cultured macrophages from dogs with natural <it>Leishmania </it>infection living in an endemic area for CanL was evaluated.</p> <p>Methods</p> <p>On the basis of one year's clinical and laboratory follow-up, 22 dogs infected by <it>Leishmania infantum </it>were identified and grouped as: asymptomatic dogs (n = 13) and dogs with symptoms of leishmaniasis (n = 9). Each animal was bled twice at 4-month intervals and macrophage and lymphocyte cultures were obtained from peripheral blood mononuclear cells. Supernatants of <it>L. infantum</it>-infected macrophage cultures, with or without addition of autologous lymphocytes, were assayed for NO production by Griess reaction for nitrites.</p> <p>Results</p> <p>In the first months of the infection the levels of NO in supernatants of <it>Leishmania</it>-infected macrophages were higher in symptomatic than in asymptomatic dogs, but they were significantly increased in the latter group eight months after the diagnosis of infection. Furthermore, NO release significantly decreased in the presence of autologous lymphocytes in both groups of animals.</p> <p>Conclusion</p> <p>These results suggest that NO may be involved in the long-term protection of dogs against natural <it>Leishmania </it>infection and in the clinical presentation of canine leishmaniasis in the Mediterranean area.</p

VOCs Measurements in Residential Buildings: Quantification via Thermal Desorption and Assessment of Indoor Concentrations in a Case-Study

Volatile organic compounds (VOCs) represent one of the most important categories of pollutants, influencing the air quality and human health and well-being in indoor environments. In the present study, 12 selected VOCs were sampled using Tenax TA tubes and analyzed by thermal desorption combined with gas chromatography and a flame ionization detector (TD-GC-FID). The TD-GC-FID method was optimized to obtain the separation of all the analytical peaks (including m- and p-xylene) and a satisfactory sensitivity, with low detection (between 0.14 and 0.31 ng) and quantification (between 0.47 and 1.02 ng) limits. The whole procedure was firstly assessed with the analysis of four co-located tubes exposed at an outdoor monitoring site, with results that revealed a very low inter-tubes variability (relative standard deviations of parallel measurements <5%). Then, the measurement protocol was used to quantify the indoor concentrations of the target VOCs in nine different homes during the dishwasher washing cycle. The most abundant detected VOC in all dwellings was d-limonene (mean: 231 µg/m3; maximum: 611 µg/m3). All the other compounds were monitored at concentration levels one or two orders of magnitude lower than d-limonene, and were generally comparable with those found in the scientific literature. In terms of health concerns, the measured concentrations were always well below the safe levels established for the protection of the general population in living environments

Analisis Percepatan terhadap Waktu Proyek (Study Kasus : Kantor Dinas SKPD Gedung B3 di Tenayan Raya)

Project implementation have always refers to the construction assumption and forecast while time plans and schedule were made, Therefore, the contruction problem will arise if there is a discrepancy between plan and assumptions comparing to the actual project. Delays of project implementation is generally always lead to adverse consequences both for the owner and contractor. The project the (SKPD) Unit City Government of Pekanbaru in Riau is having a delay of 75 days. The Best construction time acceleration is 45 days. Construction acceleration can be conducted by 3 alternatives solutions such as: overtime alternative, equipment and workers addition alternative, and shift system alternative. The analysis started from the critical path. Network project the analysis, was obtained from the cost due to delay stands at Rp. 4.761.786.975,00. Cost of construction acceleration caused by overtime alternative is Rp. 2.152.360.596,00 with a total 11.136 hours of extra work for workers, cost of construction acceleration by the workers and equipments additionionally for alternative result Rp. 2.434.965.492,00 with a total 14 new workers, with additional of 2 new equipment units. Cost of construction acceleration from shift alternative is Rp. 2.434.965.492,00 with a total of 14 new workers, a total 2 of equipment units. In conclusion, the most effective construction acceleration method is overtime alternative, obtained the minimum financial loss and recommended to use for the construction acceleration

Production of lead metal by molten-salt electrolysis with energy-efficient electrodes

"The U.S. Bureau of Mines investigated electrode designs for electrowinning lead metal from a LiCl-KCl-PbCl2 electrolyte at 450 deg C. The major objective of this investigation was to decrease the energy requirement for lead electrowinning. Electrolysis was performed in a bench-scale cell using several graphite electrode assemblies. Such parameters as electrode spacing, current density, and chlorine gas removal from the anode were investigated in the bench-scale tests. An optimum electrode assembly, termed the sawtooth design, was scaled up and operated at 3,000 and 4,000 A. The sawtooth electrodes operating at 3,000 A produced lead for 0.66 Kw.H/kg. The electrodes were constructed by cutting large triangular grooves in the electrode surfaces. The electrodes were placed together such that the triangular peaks of one electrode projected into the triangular valleys of the other electrode. Chlorine did not build up on the anode with the sawtooth electrodes." - NIOSHTIC-2NIOSHTIC no. 10008548199

Monitor and sensors 2.0 for exposure assessment to airborne pollutants

In recent years, the issue of exposure assessment to airborne pollutants has become increasingly popular, both in the occupational and environmental fields. The increasingly stringent national and international air quality standards and exposure limit values both for indoor environments and occupational exposure limit values have been developed with the aim of protecting the health of the general population and workers. On the other hand, this requires a considerable and continuous development of the technologies used to monitor the concentrations of the pollutants to ensure the reliability of the exposure assessment studies. In this regard, one of the most interesting aspects is certainly the development of “new generation” instrumentation for monitoring airborne pollutants (“Next Generation Monitors and Sensors” – NGMS). The main purpose of this work is to analyze the state of the art regarding the afore-mentioned instrumentation, to be able to investigate any practical applications within exposure assessment studies. In this regard, a systematic review of the scientific literature was carried out using three different databases (Scopus, PubMed and Web of Knowledge) and the results were analyzed in terms of the objectives set out above. What emerged is the fact that the use of NGMSs is increasingly growing within the scientific community for exposure assessment studies applied to the occupational and environmental context. The investigated studies have emphasized that NGMSs cannot be considered, in terms of the reliability of the results, to be equal to the reference measurement tools and techniques (i.e., those defined in recognized methods used for regulatory purposes), but they can certainly be integrated into the internal exposure assessment studies to improve their spatial-temporal resolution. These tools have the potential to be easily adapted to different types of studies, are characterized by a small size, which allows them to be worn comfortably without affecting the normal activities of workers or citizens, and by a relatively low cost. Despite this, there is certainly a gap with respect to the reference instrumentation, regarding the measurement performance and quality of the data provided; the objective to be set, however, is not to replace the traditional instrumentation with NGMSs but to integrate and combine the two typologies of instruments to benefit from the strengths of both, therefore, the desirable future developments in this sense has been discussed in this work

Smart-working VS office work: how does personal exposure to different air pollutants change?

The COVID-19 pandemic is raging all over the world, with possible structural effects on the work: the smart-working (WFH -Working From Home) role is therefore emphasized by the fact that it could become a traditional way of working in many work sectors. Several scientific papers have recently analyzed the WFH phenomenon under different aspects, but scientific studies have not yet been conducted considering the differences between WFH and WFO (Working From Office), in terms of evaluation of personal exposure assessment to selected airborne pollutants. This study, therefore, aims to evaluate, using portable monitors, the differences in terms of personal exposure to selected airborne pollutants, during different working conditions (WFO vs WFH), over long periods of time (from days to weeks), extending the results to even longer periods (years), to adhere to the approach proposed by the concept of the exposome. The preliminary results of this study refer to three separate phases of the work (i) re-analyses of literature data via Monte Carlo simulation, and assessment of personal exposure to different air pollutants during different working conditions, during (ii) “long term” campaign and (iii) a “short term” monitoring campaign. During the two different measurement campaigns, portable instrumentation was used, because of the ability of these kinds of instruments to obtain data characterized by a high spatial and temperature resolution. The re-elaborations of the data obtained from the literature show how, under different conditions, the exposure concentrations to different PM fractions are statistically lower in WFH working conditions, compared to WFO conditions. These results are in contrast with the preliminary results obtained from exploratory monitoring (both for the “long term” and for the “short term” campaigns). The results obtained from these exploratory monitoring show that the WFH condition has a greater impact on the daily exposure of the monitored subjects, compared to the WFO condition