Factors Associated with Negative Direct Sputum Examination in Asian and African HIV-Infected Patients with Tuberculosis (ANRS 1260)

OBJECTIVE: To identify factors associated with negative direct sputum examination among African and Cambodian patients co-infected by Mycobacterium tuberculosis and HIV. DESIGN: Prospective multicenter study (ANRS1260) conducted in Cambodia, Senegal and Central African Republic. METHODS: Univariate and multivariate analyses (logistic regression) were used to identify clinical and radiological features associated with negative direct sputum examination in HIV-infected patients with positive M. tuberculosis culture on Lowenstein-Jensen medium. RESULTS: Between September 2002 and December 2005, 175 co-infected patients were hospitalized with at least one respiratory symptom and pulmonary radiographic anomaly. Acid-fast bacillus (AFB) examination was positive in sputum samples from 110 subjects (63%) and negative in 65 patients (37%). Most patients were at an advanced stage of HIV disease (92% at stage III or IV of the WHO classification) with a median CD4 cell count of 36/mm³. In this context, we found that sputum AFB negativity was more frequent in co-infected subjects with associated respiratory tract infections (OR = 2.8 [95%CI:1.1-7.0]), dyspnea (OR = 2.5 [95%CI:1.1-5.6]), and localized interstitial opacities (OR = 3.1 [95%CI:1.3-7.6]), but was less frequent with CD4 ≤ 50/mm³ (OR = 0.4 [95%CI:0.2-0.90), adenopathies (OR = 0.4 [95%CI:0.2-0.93]) and cavitation (OR = 0.1 [95%CI:0.03-0.6]). CONCLUSIONS: One novel finding of this study is the association between concomitant respiratory tract infection and negative sputum AFB, particularly in Cambodia. This finding suggests that repeating AFB testing in AFB-negative patients should be conducted when broad spectrum antibiotic treatment does not lead to complete recovery from respiratory symptoms. In HIV-infected patients with a CD4 cell count below 50/mm3 without an identified cause of pneumonia, systematic AFB direct sputum examination is justified because of atypical clinical features (without cavitation) and high pulmonary mycobacterial burden

Moringa and Graphite as Additives to Conventional Petroleum-Based Lubricants

Many researches are focused on the tribological performances of pure vegetable oil in order to replace the conventional mineral engine oils. This work investigates the influence of local moringa oil (noted VO) on the performances of lubricants formed from a blend of dodecane and graphite particles at ambient temperature. In a first part, a reduction of about 50% of friction properties of dodecane is observed when adding small amounts of moringa oil (VO), which is intended to be used as a bio-base performance additive in lubricant formulations. The friction properties of their blends with graphite, generally employed as solid lubricant additive, showed an adsorption effect of fatty acid molecules. The more promising results were obtained for the blend containing 2 w% of VO. Physicochemical characterizations of the tribofilms evidence the good antiwear properties of the lubricant

Moringa Oil With Pristine and Fluorinated Carbon Nanofibers as Additives for Lubrication

International audienceAbstract This study focuses on the influence of local moringa oil on the performances of lubricants obtained from a blend of dodecane and pristine or fluorinated carbon nanofibers at ambient temperature. The friction experiments have been evaluated using a reciprocating ball on a plane tribometer. Moringa oil is used as a bio-additive in lubricant formulations. First, the addition of a small amount of moringa oil to dodecane allowed a reduction of about 50% of the base oil friction performances. Second, a comparative study on the friction properties of their blends with pristine carbon nanofibers (CNFs) and fluorinated ones (CF0.85) was investigated, based on which they were intended to be used as solid lubricant additives. An adsorption effect of fatty acid molecules is observed in CNFs particles unlike CF0.85. Whatever was the percentage of moringa oil added, more promising results were obtained with CF0.85. Physicochemical characterizations of the tribofilms evidence the good antiwear properties of the lubricants

Moringa Oil With Pristine and Fluorinated Carbon Nanofibers as Additives for Lubrication

International audienceThis study focuses on the influence of local moringa oil on the performances of lubricants obtained from a blend of dodecane and pristine or fluorinated carbon nanofibers at ambient temperature. The friction experiments have been evaluated using a reciprocating ball on a plane tribometer. Moringa oil is used as a bio-additive in lubricant formulations. First, the addition of a small amount of moringa oil to dodecane allowed a reduction of about 50% of the base oil friction performances. Second, a comparative study on the friction properties of their blends with pristine carbon nanofibers (CNFs) and fluorinated ones (CF0.85) was investigated, based on which they were intended to be used as solid lubricant additives. An adsorption effect of fatty acid molecules is observed in CNFs particles unlike CF0.85. Whatever was the percentage of moringa oil added, more promising results were obtained with CF0.85. Physicochemical characterizations of the tribofilms evidence the good antiwear properties of the lubricants

An Epidemic of Bloody Diarrhea: Escherichia coli O157 Emerging in Cameroon?

Between November 1997 and April 20, 1998, bloody diarrhea sickened 298 persons in Cameroon. Laboratory investigation of the epidemic (case-fatality rate, 16.4%) documented amoebiasis in one of three patients and three types of pathogens: multidrug-resistant Shigella dysenteriae type 1, S. boydii, and enterohemorrhagic Escherichia coli. We report the first isolation of E. coli O157:H7 in Cameroon and the second series of cases in the Central African region

Evaluation of the molecular inclusion process of β-hexachlorocyclohexane in cyclodextrins

The present work aimed to study the guest–host complexes of β-hexachlorocyclohexane (β-HCH), a pesticide with high environmental stability that can cause severe health problems, with the most common cyclodextrins (α-, β-, and γ-CDs). The formation reactions of these molecular inclusion complexes were addressed in this research. The multiple minima hypersurface methodology, quantum calculations based on density functional theory and a topological exploration of the electron density based on the quantum theory of atoms in molecules approach were used to characterize the interaction spaces of the pollutant with the three CDs. Additionally, charge distribution, charge transfer and dual descriptor analyses were employed to elucidate the driving forces involved in the formation of these molecular inclusion complexes. Three types of fundamental interactions were observed: total occlusion, partial occlusion and external interaction (non-occlusion). Finally, experiments were performed to confirm the formation of the studied complexes. The most stable complexes were obtained when γ-CD was the host molecule. The interactions between the pesticide and CDs have fundamentally dispersive natures, as was confirmed experimentally by spectroscopic results. All the obtained results suggest the possibility of using CDs for the purification and treatment of water polluted with β-HCH.ISSN:2046-206

Baseline characteristics of the study population.

<p>*Global comparison among the three countries.</p><p>**Median (Q1, Q3).</p

Factors associated with sputum smear negativity by univariate and multivariate analysis.

<p>*OR: Odds Ratio.</p