Pathologie-biologie最新文献

Hyaluronan (hyaluronic acid, HA) is a ubiquitous linear polysaccharide endowed with some exceptional physicochemical properties such as strong hydration and viscoelasticity that depend on the size of the molecule. It plays a variety of important physiological roles in tissue hydration and mechanical protection, for example in the umbilical cord, skin and most other tissues. Since its large scale preparation and the invention by E.A. Balazs of the preparation of its non-inflammatory fraction (NIF-NaHA), there have been several important medical and cosmetic applications, most notably of viscosurgery for eye operation, intra-articular injections for osteoarthritis and also for wrinkle filling on the face, as well as for drug administration. Its concentration in tissues is decreasing with age, source of loss of function and structure of tissues. The purpose of this review is to present a succinct overview of the essential properties of hyaluronan and its medical and esthetic applications.

Thyroid cancer is an uncommon cancer. Molecular biology plays a vital role in its development. Chemotherapy showed unsatisfactory results in advanced stages where surgery and iodine therapy are not appropriate. These last ten years have been marked by a major advance in understanding the molecular features of this cancer and therapeutic correlations, moreover, clinical trials have focused on the treatment of this disease on metastatic stages and led to a significant therapeutic panel targeting angiogenesis, mutations frequently found in cervical cancer: RET, BRAF, RAS… these are the motesanib, axitinib, sunitinib, pazopanib, vandetanib, cabozotinib and sorafenib. The last three molecules have already the autorisation of FDA and EMA. In this review, we will put the item on oncogenetic characteristics of thyroid carcinoma as well as new targeted therapies in patients refractory to conventional treatment.

Background

The cyclooxygenase-2 (cox-2) pathway is now recognized to be important in human cancer development and progression. The gene for cox-2 carries a common single nucleotide polymorphism, T8473 C, located within a potential functional region in the 3′-UTR of cox-2 gene was identified. We have investigated the frequencies of cox-2 genotypes in Tunisian population to determine whether that polymorphism was associated with the risk of nasopharyngeal carcinoma (NPC) in Tunisian population.

Material and methods

One hundred and eighty-nine NPC patients were compared to 237 healthy controls.

Results

The cox-2 T8473C polymorphism was significantly associated with NPC (P = 0.031). The CC-genotype and C allele were more frequent in control compared to patients group [CC: OR = 0.37; P = 0.013; 95% CI: 0.17–0.81; C: OR = 0.72; P = 0.032; 95% CI: 0.53–0.97]. Multivariate logistic regression analyses revealed that the CC-genotype was associated with a significantly decreased risk of NPC (P = 0.013). Tumor sizes, histologic grade, presence of primary lymph node metastases, age or sex were not associated with cox-2 genotypes.

Conclusion

We conclude that the CC-genotype and C allele of cox-2 T8473C gene polymorphism are associated with decreased risk of nasopharyngeal carcinoma in a Tunisian population.

Objective

Multidrug-resistant organisms (MDROs) have become a widespread serious problem in recent years. Our objective was to determine the prevalence and clinical distribution of MDROs in a tertiary care hospital in China from January 1, 2012 to December 31, 2013.

Methods

The strains were cultured according to standard methods; bacterial identification and susceptibility testing were detected by Vitek 2 system. The prevalence and clinical distribution of extended-spectrum β-lactamases (ESBLs)-producing enterobacteriaceae, carbapenem-resistant enterobacteriaceae (CRE), multiple-drug/pan-drug resistant P. aeruginosa (MDR/PDR-PA), carbapenem-resistant A. baumannii (CR-AB), methicillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococcus (VRE) were analyzed by WHONET 5.6.

Results

A total of 3537 (33.4%) MDROs were found among 10,594 microbial isolates. ESBLs producing E. coli (ESBLs-ECO) (1153 cases) were the most frequent MDROs, followed by CR-AB (827 cases). The proportion of acquired resistance of A. baumannii (48.9%) accounted for the highest in all the MDROs. These MDROs were mainly isolated from respiratory (70.3%) and secretions (12.7%). Various types of intensive care unit (ICU) and surgery were the main source departments. The proportion of CRE and VRE were relatively few. CRE was most isolated from respiratory tract and closed body cavity fluid, while the distribution of VRE was relatively dispersed.

Conclusion

High prevalence of MDROs has emerged in our hospital, particular in various ICU and surgical department. The effective way to prevent the further spread of MDROs is to strengthen the protection of respiratory tract and surgical wounds.

Effective antiretroviral therapy usually leads to undetectable HIV-1 RNA in the plasma. However, the virus persists in some cells of infected patients as various DNA forms, both integrated and unintegrated. This reservoir represents the greatest challenge to the complete cure of HIV-1 infection and its characteristics highly impact the course of the disease. The quantification of HIV-1 DNA in blood samples constitutes currently the most practical approach to measure this residual infection. Real-time quantitative PCR (qPCR) is the most common method used for HIV-DNA quantification and many strategies have been developed to measure the different forms of HIV-1 DNA. In the literature, several “in-house” PCR methods have been used and there is a need for standardization to have comparable results. In addition, qPCR is limited for the precise quantification of low levels by background noise. Among new assays in development, digital PCR was shown to allow an accurate quantification of HIV-1 DNA. Total HIV-1 DNA is most commonly measured in clinical routine. The absolute quantification of proviruses and unintegrated forms is more often used for research purposes.

Oriented collagen biosynthesis is one of the major mechanisms involved in tissue and organ formation during development. Corneal biogenesis is one example. Defects in this process lead to anomalies in tissue structure and function. The transparency of cornea and its achievement are a good example as well as its pathological modifications. Keratoconus is one example of this type of pathologies, involving also inappropriate cross-linking of collagen fibers. Among the tentatives to correct this anomaly, the riboflavin-potentiated UV-cross-linking (CXL) of keratoconus corneas appears clinically satisfactory, although none of the experiments and clinical results published prove effective cross-linking. The published results are reviewed in this article.

Until now, the identification of micro-organisms has been based on the cultural and biochemical characteristics of bacterial and fungal species. Recently, Mass Spectrometry type Matrix-Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF MS) was developed in clinical microbiology laboratories. This new technology allows identification of micro-organisms directly from colonies of bacteria and fungi within few minutes. In addition, it can be used to identify germs directly from positive blood culture bottles or directly from urine samples. Other ways are being explored to expand the use of MALDI-TOF in clinical microbiology laboratories. Indeed, some studies propose to detect bacterial antibiotic resistance while others compare strains within species for faster strain typing. The main objective of this review is to update data from the recent literature for different applications of MALDI-TOF technique in microbiological diagnostic routine.

The gut microbiota is increasingly considered as a symbiotic partner in the maintenance of good health. Metagenomic approaches could help to discover how the complex gut microbial ecosystem participates in the control of the host's brain development and function, and could be relevant for future therapeutic developments, such as probiotics, prebiotics and nutritional approaches for psychiatric disorders. Previous reviews focused on the effects of microbiota on the central nervous system in in vitro and animal studies. The aim of the present review is to synthetize the current data on the association between microbiota dysbiosis and onset and/or maintenance of major psychiatric disorders, and to explore potential therapeutic opportunities targeting microbiota dysbiosis in psychiatric patients.

Background

Lipopolysaccharide (LPS) has pro-inflammatory properties. This study was conducted to determine whether the LPS induced pro-inflammatory response in a model of mastitis and in mouse mammary epithelial cells (MEC).

Methods

To investigate the effects of LPS in vivo, 50 μL of a solution of LPS (20 ng/μL) were infused into the mammary glands of mice. To study the effects of LPS in vitro, MEC were exposed to LPS (20 μg/mL) for 24 h. Activation of nuclear factor kB (NF-κB) and myeloperoxidase (MPO) were studied. Production of pro-inflammatory cytokines (interleukin-6 [IL-6], tumor necrosis factor-alpha [TNF-alpha], interleukin-1 beta [IL-1beta]) and expression of osteopontin (OPN) were also evaluated.

Results

After LPS administration, route of NF-κB signaling is activated and the activity of MPO is increased. Furthermore, LPS increases the expression of OPN and production of TNF-alpha, IL-6 and IL-1beta.

Conclusions

Present results demonstrate that LPS induces a pro-inflammatory response in a murine model of mastitis and suggest the involvement of the NF-κB pathway and OPN.