Toxoplasma gondii infection can regulate the expression of tumour necrosis factor-alpha receptors on human cells in vitro

The in vitro regulation of tumour necrosis factor (TNF)-alpha receptors during Toxoplasma gondii infection of human MRC5 fibroblasts and human myelomonocytic THP-1 cells was investigated. Cells were infected with the virulent RH of T. gondii. TNFR membrane receptors were analysed by flow cytometry with biotinylated TNF-alpha. Shedding of the soluble form of TNFR1 and TNFR2 in cell culture supernatants was measured by enzyme-linked immunosorbent assay, and expression of mRNA production of TNFR1 and TNFR2 was analysed by quantitative real-time polymerase chain reaction, 1 h after infection. In the MRC5 cell line, T. gondii infection did not induce any up- or down-regulation of membrane TNFRs, soluble TNFRs or mRNA of TNFRs. However, THP-1 cell infection with living parasites induced a significant soluble TNFR1 release by THP-1 cells after 1 h. We detected an approximately 50% up-regulation (P < 0.01) of soluble TNFR1 in infected THP-1 cells compared to controls. No change in soluble TNFR2 levels was observed in the same conditions. Moreover, infection decreased the level of TNF membrane receptors, but had no effect on TNFR1 and TNFR2 mRNA levels. TNFR modulation by T. gondii infection, in vitro, depends on the cell type. Furthermore, our data suggest that living parasites control the shedding of the soluble form of TNFR1. This mechanism may influence the role of TNF-alpha in toxoplasmosis.     

FCGR3B allele frequencies in Tunisians of sub-Saharan origin

Purpose of the studyThe importance of human neutrophil antigens (HNA) in immunogenetics and their involvement in hematologic diseases have accelerated the elucidation of their molecular basis and their allele frequencies distribution has been described in many populations over the world. In this study, our aim was to evaluate the frequency of FCGR3B alleles encoding HNA-1a, 1b and 1c among Tunisians of sub-Saharan origin and to compare them to Tunisian blood donors and to a group from sub-Saharan Africa.Patients and methodsWe typed the DNA of 106 individuals (62 Tunisians of sub-Saharan origin, 33 Tunisian blood donors and 11 from sub-Saharan Africa) for the three FCGR3B alleles by polymerase chain reaction using sequence specific primer (PCR-SSP).ResultsFCGR3B*1, FCGR3B*2 and FCGR3B*3 allele frequencies were respectively 0.347, 0.573 and 0.080 among Tunisians of sub-Saharan origin, 0.379, 0.591 and 0.030 among Tunisian blood donors and 0.318, 0.546 and 0.136 among the group from sub-Saharan Africa.ConclusionThese allele frequencies were similar to those previously reported in other black and white populations. The frequencies found in the two Tunisian groups confirm the intermixing origin from Europe, sub-Africa and Asia of the Tunisian population. Our results provide a database for future studies of the HNA system and associated diseases in Tunisia.     

Clinically relevant behaviors in elderly hip fracture inpatients

OBJECTIVE: To examine the range of behaviors documented by inpatient rehabilitation staff and the association of these behaviors with functional outcome, in elderly persons undergoing rehabilitation after hip fracture. METHOD: Subjects were 137 patients, aged 60 and older, admitted to a rehabilitation hospital after a hip fracture, defined as having either a good or poor rehabilitation outcome based on change in Functional Independence Measure motor subscale scores during the course of their admission. Their charts were systematically reviewed for nursing and therapy staff documentation of behaviors. Prevalence of behaviors was compared between good and poor rehabilitation outcome group. RESULTS: Disturbances in cognition and rehabilitation participation were common and were associated with poorer rehabilitation outcome. Behaviors reflective of depression and anxiety were relatively uncommon and not associated with rehabilitation outcome. CONCLUSION: Rehabilitation staff frequently detect and document disturbances in cognition and participation that are associated with poorer rehabilitation outcome. It is recommended that staff observations be routinely added to mental health evaluations. Additionally, routine mental health screening and required staff documentation of behaviors would improve case detection rate.     

Enterococcus faecalis: a multicenter study on antibiotic resistance]

676 E. faecalis strains were listed over a period of 2 years from the Charles Nicolle hospital of Tunis (167 strains), the Habib Bourguiba hospital of Sfax (350 strains) and the National Centre of Bone marrow Transplantation of Tunis (159 strains). Antibiotic sensibility study was realized by the method of the antibiogram, E-test method and the search of penicillinase by cefinase. E. faecalis resulted essentially from services of onco-haematology (24%), external consultations (23%), surgery (18%) and medicine (15%). These strains were isolated especially from urines (54%), coprocultures (15%), bloodcultures (11%) and from pus (9%). Resistance acquired with these strains is raised for erythromycin, tetracyclin and chloramphenicol (81% to 86%), followed by high level resistance to gentamicine (37%). 0.1% of E. faecalis strains have a low level resistance to amoxicillin without production of penicillinase. No resistance to vancomycin was observed.     

Detection of Chlamydia trachomatis in semen and urethral specimens from male members of infertile couples in Tunisia.

The sequelae to infection with Chlamydia trachomatis in women are an established cause of tubal infertility. However, little is known about chlamydial infection and male infertility. The main objective of this study was to evaluate the presence of asymptomatic C. trachomatis infections in urethral and semen specimens from the male members of infertile couples by means of four different methods: the direct fluorescence antibodies assay, cell culture, the Roche Cobas Amplicor polymerase chain reaction, and the presence of chlamydial local IgA antibodies by the recombinant antibody-enzyme-linked immunosorbent assay. One or more chlamydial infection markers were detected in 42 (45.7%) of the 92 examined urethral and semen specimens from the male partners of infertile couples. C. trachomatis was detected in 23.9% (22/92) of urethral specimens and in 35.9% (33/92) of semen specimens. Although there was a significant correlation between the detection of one or more chlamydial infection markers in urethral and semen specimens (p = 0.01), no significant correlation was found between the detection of C. trachomatis DNA in these samples. Furthermore, no significant association was found between the presence of chlamydial local IgA antibodies and the detection of C. trachomatis. The discrepancies in positive results found between some techniques for the detection of C. trachomatis in urethral and semen specimens might be explained by variations in the sensitivities and specificities of the tests carried out and the use of specimens from different anatomical locations. Our findings suggest that C. trachomatis seems to be widespread among the male partners of infertile couples in Tunisia. The detection of C. trachomatis in urethral or semen specimens can serve as a marker for the presence of this organism in the genital tract, which is not necessarily the cause of male infertility. The study of the correlation between the detection of chlamydial infection markers and the parameters of male fertility seems to be necessary in order to determine the direct link between chlamydial infection and male infertility and to choose the most efficient technique and most suitable specimen with which to diagnose C. trachomatis-associated male infertility.     

New insights into the competition between antioxidant activities and pro-oxidant risks of rosmarinic acid

Direct and indirect antioxidant activities of rosmarinic acid (RA) based on HOO˙/CH₃OO˙ radical scavenging and Fe(iii)/Fe(ii) ion chelation were theoretically studied using density functional theory at the M05-2X/6-311++G(2df,2p) level of theory. First, four antioxidant mechanisms including hydrogen atom transfer (HAT), radical adduct formation (RAF), proton loss (PL) and single electron transfer (SET) were investigated in water and pentyl ethanoate (PEA) phases. Regarding the free radical scavenging mechanism, HAT plays a decisive role with overall rate coefficients of 1.84 × 10³ M⁻¹ s⁻¹ (HOO˙) and 4.49 × 10³ M⁻¹ s⁻¹ (CH₃OO˙) in water. In contrast to PL, RAF and especially SET processes, the HAT reaction in PEA is slightly more favorable than that in water. Second, the [Fe(iii)(H₂O)₆]³⁺ and [Fe(ii)(H₂O)₆]²⁺ ion chelating processes in an aqueous phase are both favorable and spontaneous especially at the O5, site-1, and site-2 positions with large negative Δ_rG⁰ values and great formation constant K_f. Finally, the pro-oxidant risk of RA⁻ was also considered via the Fe(iii)-to-Fe(ii) complex reduction process, which may initiate Fenton-like reactions forming reactive HO˙ radicals. As a result, RA⁻ does not enhance the reduction process when ascorbate anions are present as reducing agents, whereas the pro-oxidant risk becomes remarkable when superoxide anions are found. The results encourage further attempts to verify the speculation using more powerful research implementations of the antioxidant activities of rosmarinic acid in relationship with its possible pro-oxidant risks.

Direct and indirect antioxidant activities of rosmarinic acid (RA) based on HOO˙/CH₃OO˙ radical scavenging and Fe(iii)/Fe(ii) ion chelation were theoretically studied using density functional theory at the M05-2X/6-311++G(2df,2p) level of theory.     

A New Biologically Inspired Fuzzy Expert System-Based Voiced/Unvoiced Decision Algorithm for Speech Enhancement

In this paper, we propose a speech enhancement approach for a single-microphone system. The main idea is to apply a specific transformation on the speech signal depending on the voicing state of the signal. We apply a voiced/unvoiced algorithm based on the multi-scale product analysis with the use of fuzzy logic to make more cognitively inspired use of speech information. A comb filtering is applied on the voiced frames of the noisy speech signal, and a spectral subtraction is operated on the unvoiced frames of the same signal. Further, the harmonics are enhanced by performing a designed comb filtering using an adjustable bandwidth. The comb filter is tuned by an accurate fundamental frequency estimation method. The fundamental frequency estimation method is based on computing the multi-scale product analysis of the noisy speech. Experimental results show that the proposed approach is capable of reducing noise in adverse noise environments with little speech degradation and outperforms several competitive methods.