Pathologie-biologie最新文献

We evaluated the Bruker Biotyper matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry (MS) for the identification of 97 Corynebacterium clinical in comparison to identification strains by Api Coryne and MALDI-TOF-MS using 16S rRNA gene and hypervariable region of rpoB genes sequencing as a reference method. C. striatum was the predominant species isolated followed by C. amycolatum. There was an agreement between Api Coryne strips and MALDI-TOF-MS identification in 88.65% of cases. MALDI-TOF-MS was unable to differentiate C. aurimucosum from C. minutissimum and C. minutissimum from C. singulare but reliably identify 92 of 97 (94.84%) strains. Two strains remained incompletely identified to the species level by MALDI-TOF-MS and molecular approaches. They belonged to Cellulomonas and Pseudoclavibacter genus. In conclusion, MALDI-TOF-MS is a rapid and reliable method for the identification of Corynebacterium species. However, some limits have been noted and have to be resolved by the application of molecular methods.

Background

Serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE) are used for diagnosis and follow-up of patients with intact immunoglobulin multiple myeloma. However, the numerous limitations of these methods led to the development of a nephelometric immunoassay (Hevylite™) for the specific measurement of serum IgGκ, IgGλ, IgAκ and IgAλ concentrations.

Methods

In this study, we evaluated the correlation between this assay and SPE and IFE in 114 sera of 15 patients (12 IgG and 3 IgA patients) and its impact on the clinical care of patients, especially for diagnosis, for the evaluation of residual disease and for early detection of relapse.

Results

At inclusion and during follow-up, we found a good correlation between monoclonal immunoglobulin concentrations and SPE (R² = 0.902 for IgA and R² = 0.915 for IgG) and nephelometric quantification (R² = 0.948 for IgA and R² = 0.920 for IgG) for the evaluation of monoclonal and polyclonal immunoglobulins. Our results illustrate that the Hevylite™ test is less sensitive than the IFE for detection of residual disease: 5 patients who obtained very good partial response or complete response had normalization of the Hevylite™ ratio while IFE was still positive. A relapse had been detectable with the Hevylite™ ratio 1 to 2 months earlier than with SPE and IFE in 3 patients out of 15, but no recommendations for treating patients with only slight biological relapse are available.

Conclusion

Our results demonstrate that heavy/light chain specific immunoglobulin ratios provides no additional information than serum proteins electrophoresis and immunofixation for the diagnosis and the follow-up of intact immunoglobulin multiple myeloma patients. We also studied the correlation between the concentration of total immunoglobulin measured by Hevylite™ (sum of Ig’κ + Ig’λ) and nephelometric measurement of total IgG or IgA. For this correlation analysis, all 114 sera were analyzed. The correlation coefficient was R² = 0.948 for IgA and R² = 0.920 for IgG.

Purpose

In this work, we are interested to study the implication of −509C/T polymorphism, located in the promoter region of TGFB1 (transforming growth factor β1), in the phenotypic variability of CF patients.

Patients and methods

The present study enrolled 111 CF patients and 100 healthy control subjects. The study of the −509C/T polymorphism was performed using PCR-RFLP method.

Results

We found that patients carried non-F508del homozygous mutation with TT genotype was associated to lung symptoms (P = 0.04). This association was not found in the sub-groups of patients with F508del at homozygous state P = 0.145. No association was found between this polymorphism and the variability of digestive, pancreatic and ileus meconial symptoms.

Conclusion

On the basis of our results, the −509C/T polymorphism of the TGFB1 gene seems to be a modulator factor of cystic fibrosis.

Background

Chromosomal class A β-lactamases have been characterized in Raoultella ornithinolytica and Raoultella planticola. The purpose of this study was to characterize that of Raoultella terrigena.

Materials and methods

The bla_TER-1 gene of R. terrigena strain ATCC33257^T was cloned (pACter-1) and sequenced. It was then used to detect the bla gene of strains BM 85 01 095 and SB2796. The hypermutable Escherichia coli strain AB1157 mutS::Tn10 was transformed with pACter-1 and mutants growing on plates containing > 2 mg/L ceftazidime were studied. Notably, the impact of mutations only observed in the promoter region on β-lactam resistance was assessed by site-directed mutagenesis experiments.

Results

R. terrigena strains ATCC33257^T and BM 85 01 095 had the same bla gene and deduced protein (TER-1) whereas there were 3 substitutions in those of strain SB2796 (TER-2). Class A β-lactamases TER showed 78%, 69.9% and 38.7% identity with PLA or ORN, TEM-1 and KOXY, respectively. Compared with TEM-1, TER-1 and TER-2 showed 2 particular substitutions, Leu75Pro and Glu240Asn demonstrated to be involved in the inherent β-lactam resistance profile of R. terrigena. TER-1 (pI of 7.6) had a high activity against penicillin G and a significantly low one against amoxicillin. Substitution G/T observed in the -35 region of the bla_TER gene harbored by strains growing in the presence of ≥ 2 mg/L ceftazidime was shown to be responsible for this growth.

Conclusion

TER is a new class A β-lactamase belonging to functional group 2b.

Hematopoetic stem cell transplantation (HSCT) improves survival in patients with severe systemic sclerosis (SSc) by resetting the immune system. We studied how HSCT acts on the key SSc skin pathology findings (fibrosis and vascularization). In mean, 3 skin punch biopsies per patient (range 2–6) were analyzed from 13 patients (5 females) with severe diffuse SSc before and up to 96 months after HSCT. Fibrosis of the four skin layers was graded semi-quantitatively and an overall fibrosis score was then calculated. Vessel numbers and calibers were assessed in the superficial and deeper dermis after immune-staining for endothelial antigens (CD31, VE-cadherin and vWF). The median age of patients at HSCT was 47 (24–64) years. The overall median modified Rodnan skin score decreased from 24 to 10 (P = 0.003) at first follow-up within a median of 9 (6–36) months after HSCT as did the histological skin score (P = 0.03). The modified Rodnan skin score and the fibrosis score correlated positively (r = 0.589, P < 0.001). The vessels density did not significantly change after HSCT nor did the expression of the tested endothelial markers. Although improving skin fibrosis in patients with SSc, HSCT does not alter vessel density within skin biopsies.

Triple-negative breast cancers are not a homogeneous subgroup. There is substantial intra-subgroup diversity in tumor biology, prognosis and treatment sensitivity. Then, these triple-negative phenotype (TNP) groups, having specific features, can be again divided into subclasses based on an added immunohistochemical markers. The challenge in treating TNP breast cancers is that they are not responsive to antiestrogens or trastuzumab secondary to negative receptor status, and as a result have a poor prognosis. Therefore, the presence or absence of supplementary markers could help predict which therapies are best suited for patients based on the pattern that their disease markers show. In this review, we will recapitulate the major supplementary biomarkers related to triple-negative breast cancer, which could give new therapeutic options.

Objective

The aim of the present study was to study the modulatory potential of Azadirta indica on colonic surface abnormalities and membrane fluidity changes following 1,2 dimethylhydrazine-induced [DMH] colon carcinogenesis.

Materials and methods

Brush border membranes [BBM] were isolated from the colon of rats and the viscosity as well as fluidity parameters were assessed by using the membrane extrinsic fluorophore pyrene.

Results

DMH treatment resulted in a significant increase in lipid peroxidation [LPO]. Reduced glutathione levels [GSH] and the activities of glutathione reductase [GR], glutathione transferase [GST], superoxide dismutase [SOD], catalase [CAT] and glutathione peroxidase [GPx] were found to be significantly decreased following DMH treatment. On the other hand, supplementation with AI, DMH-treated rats resulted in a significant decrease in the levels of lipid peroxidation but caused a significant increase in the levels of GSH as well in the activities of GR, GST, SOD, CAT and GPx. The results further demonstrated a marked decrease in membrane microviscosity following DMH treatment. On the other hand, a significant increase was observed in the excimer/monomer ratio and fluidity parameter of DMH-treated rats when compared to normal control rats. However, the alterations in membrane microviscosity and the fluidity parameters were significantly restored following A. indica treatment. Further, histological as well as colon surface alterations were also observed following DMH treatment, which however were greatly prevented upon AI co-administration.

Conclusions

The study, therefore, concludes that A. indica proves to be useful in modulating the colonic surface abnormalities and membrane stability following DMH-induced colon carcinogenesis.

Purpose

Determining the frequency of M470V polymorphism in cystic fibrosis and healthy cohort in Tunisia to establish the contribution of M470V polymorphism in cystic fibrosis variable presentation and course. Additionally, studying the origin of cystic fibrosis transmembrane conductance regulator gene in Tunisian population and its evolution among populations worldwide.

Patients and methods

The genotyping of M470V marker was realized by PCR-RFLP technique in 34 unrelated patients and 50 healthy subjects.

Results

Statistical difference was found in the genotype and allelic distribution between CF and control groups. Exclusive association between F508del allele and M470 allele was noted.

Conclusion

This study has contributed to better understanding involvement of the M470V polymorphism in the CF clinical expression in the Tunisian population and has confirmed the utility of this marker in the study of the origin and evolution of the CFTR locus in the human history.

Background

Breast cancer is increasing among young women in Tunisia. Germline mutations in the BRCA1/2 genes are associated with a high risk for breast cancer development. However, the true contribution of BRCA1/2 mutation in sporadic breast cancer is not well documented. Our aim is to identify the BRCA2 mutation spectrum in Tunisian young women with breast cancer.

Methods

Screening the BRCA2 gene was performed using DHPLC, DNA sequencing and PCR-RFLP.

Results

We identified, in a woman diagnosed with early onset breast cancer, and without family history, a novel in frame deletion 5456delGTAGCA in the exon 11 of the BRCA2 gene which causes a loss of two residues Ser1743-Ser1744. The absence of this deletion in the patients’ parents suggests that it is a de novo variant. Furthermore, we screened 108 sporadic cases, 50 familial cases, and 60 controls for the identified del6bp using PCR-RFLP. None of them carried this deletion suggesting that this variant is not a benign polymorphism and probably rare in our population. With regards to the position of the Ser1743-1744 in the BRCT domain, sequence alignment revealed that the Ser1743 is conserved among several species, which may reflect its importance in the BRCA2 function. A modeling of the wild-type and mutated BRC5-BRC6 domain revealed that the deletion of the 2 Serine residues might affect the structure of this BRCA2 domain.

Conclusions

A novel in frame deletion 5456del6bp in BRCA2 gene was identified in an early onset woman with breast cancer and without family history.

Purpose of the study

To investigate whether CCL18 is involved in breast cancer, and the relationship between CCL18 and MVD (MVD was recognized by CD34) which is a well-accepted angiogenic maker of multiple cancers including breast cancer.

Patients and methods

Immunohistochemistry staining for CCL18 and CD34 was performed on 179 cases, including 29 normal cases as control, 47 cases with benign breast diseases, and 103 cases with breast cancer.

Results

We found that CCL18 was significantly up-regulated in breast cancer samples as compared with benign tumors or normal breast tissues. Moreover, the expression level of CCL18 increased with the size of tumors, the number of lymph node metastasis, and advancing tumor stage, suggesting that CCL18 expression correlates with tumor malignancy scales. At the same time, we found that MVD was also significantly over-expressed in cancer tissues as compared with normal control group and benign tumor group, but it was not significantly differentially expressed among tumors with different malignancy scale like CCL18, while the expression of MVD in CCL18 positive breast cancer cases was higher than in the CCL18 negative breast cancer cases (P = 0.016, P < 0.05).

Conclusion

CCL18 is involved in the development of breast cancer. CCL18 is a better biomarker than MVD in determining whether the tumor is malignant and the severity of malignancy of breast cancer.