Selective sequestration of X4 isolates by human genital epithelial cells: Implication for virus tropism selection process during sexual transmission of HIV

X4 and R5 HIV strains are present in the semen of men infected with HIV but R5 isolates are transmitted preferentially. The role of human epithelial cells in this selection is addressed. Three human cervical cell lines-CaSki, SiHa, and HEC1A-and normal human vaginal cells from HIV-negative donors were characterized for HIV receptor expression and incubated with X4 and R5 laboratory-adapted strains or primary isolates. The infection was assessed by detection of intracellular HIV DNA. The three cell lines were shown to express on their surface the CXCR4 and GalCer molecules, but not the CD4 and CCR5 ones. The three cell lines and normal human vaginal cells were found to be selectively permissive to X4 HIV entry; the preincubation of the cell lines with rhSDF-1 inhibited this infection. The detection of the intracellular proviral DNA in the cell lines and in normal human vaginal cells demonstrated a selective integration of X4 strains. Additional experiments showed that no extracellular RNA was detected in the supernatants of HEC1A cells infected by X4 isolates either after 18 days of culture or after incubation with PHA-stimulated PBMCs and that no transmission occurred after co-culture between infected HEC1A cells and PHA-stimulated PBMCs. These results suggest specific sequestration of X4 strains by genital epithelial cells, which could explain, at least in part, the HIV tropism selection process during sexual intercourse.     

Febrile neutropenia in cancer patients in a tertiary care medical center in Lebanon: microbial spectrum and outcome

We prospectively analyzed the episodes of febrile neutropenia at the American University of Beirut Medical Center. One hundred and four episodes were studied in 64 patients over a period of 15 months: 81 (78%) with leukemia, 11 (10.5%) with lymphoma, 3 (2.8%) with multiple myeloma, and 9 (8.6%) with solid tumors. Bacteremia was confirmed in 30 episodes (29%), of which 18 (60%) were caused by gram-negative bacilli and 12 (40%) by gram-positive cocci. The predominant organisms were: E. coli (9), coagulase negative staphylococci (CNS) (6), Pseudomonas aeruginosa (5), and S. aureus (4). In seven episodes (6.7%) urinary tract infections were diagnosed, 6 with E. coli. Sputum cultures were positive in eight episodes (7%), 2 with P. aeruginosa, and 2 with methicillin resistant S. aureus. All patients were started empirically on antibacterial agents. In twenty-one episodes, a single antibiotic was started, ceftazidime being the most commonly used agent. In most cases, however, 2 or 3 antibacterial agents were started empirically. Antifungal therapy with amphotericin B (11) or fluconazole (20) was added because of persistent fever despite broad antibacterial coverage. Thirteen patients died (20%), 6 of them had bacteremia; 2 with gram-negative bacilli, and 4 with gram-positive cocci. Except for one, all patients had been started, at the onset of the fever, on antimicrobial agents to which the isolated microorganisms turned out to be susceptible. Our results show that infections with gram-negative bacteria continue to predominate unlike what has been reported recently from European and North American trials. A trend toward a higher mortality of infections caused by gram-positive cocci was noted.     

Lens thickness assessment: anterior segment optical coherence tomography versus A-scan ultrasonography

AIM: To assess lens thickness measurements with anterior segment-optical coherence tomography (AS-OCT) in comparison with A-scan ultrasonography (A-scan US). METHODS: There were 218 adult subjects (218 eyes) aged 59.2±9.2y enrolled in this prospective cross-sectional study. Forty-three eyes had open angles and 175 eyes had narrow angles. Routine ophthalmic exam was performed and nuclear opacity was graded using the Lens Opacities Classification System III (LOCS III). Lens thickness was measured by AS-OCT (Visante OCT, Carl Zeiss Meditec, Dublin, CA, USA). The highest quality image was selected for each eye and lens thickness was calculated using ImageJ software. Lens thickness was also measured by A-scan US. RESULTS: Interclass correlations showed a value of 99.7% for intra-visit measurements and 95.3% for inter-visit measurements. The mean lens thickness measured by AS-OCT was not significantly different from that of A-scan US (4.861±0.404 vs 4.866±0.351 mm, P=0.74). Lens thickness values obtained from the two instruments were highly correlated overall (Pearson correlation coefficient=0.81, P<0.001), and in all LOCS III specific subgroups except in grade 5 of nuclear opacity. Bland-Altman analysis revealed a 95% limit of agreement from -0.45 to 0.46 mm. Lens thickness difference between the two instruments became smaller as the lens thickness increased and AS-OCT yielded smaller values than A-scan US in thicker lens (β=-0.29, P<0.001) CONCLUSION: AS-OCT-derived lens thickness measurement is valid and comparable to the results obtained by A-scan US. It can be used as a reliable noncontact method for measuring lens thickness in adults with or without significant cataract.     

Contribution of depression and anxiety to impaired quality of life in survivors of myocardial infarction

Objective. To quantify the adverse influence of depression and anxiety assessed at the time of myocardial infarction, on the quality of life 5 years after the infarction. Methods. The Beck Depression Inventory (BDI) and the State-Trait Anxiety Inventory (STAI) were completed in a group of 196 patients admitted in the hospital following non-fatal myocardial infarction, and the SF-12 quality of life questionnaire was administered during the 5- year follow-up. Results. Regression analysis showed a strong association between baseline depression and QoL in both the physical and mental domains; the higher the depression scores, the poorer the QoL. However, anxiety present at the time of myocardial infarction did not predict later QoL. Conclusions. Depression but not anxiety following MI predicts longer-term quality of life in myocardial infarction survivors.     

Ready-to-use binder-free Co(OH)2 plates@porous rGO layers/Ni foam electrode for high-performance supercapacitors

In this work, an outstanding nano-structured composite electrode is fabricated through the co-deposition of Co(OH)₂ nanoplates and porous reduced GO (p-rGO) nanosheets onto Ni foam (NF). Through field emission scanning electron microscopy and transmission electron microscopy observations, it was confirmed that porous reduced graphene oxide sheets are completely wrapped by uniform hexagonal Co(OH)₂ plates. Due to the unique architecture of both components of the prepared composite, a high surface area of 234.7 m² g⁻¹ and mean pore size of 3.65 nm were observed for the Co(OH)₂@p-rGO composite. The constructed Co(OH)₂@p-rGO/NF composite electrode shows higher energy storage capability compared to that of Co(OH)₂/NF and p-rGO/NF electrodes. The Co(OH)₂/NF electrode shows specific capacitances of 902 and 311 F g^–1 at 5 and 30 A g^–1, while the Co(OH)₂@p-rGO/NF electrode delivers 1688 and 1355 F g^–1 under the same current loads, respectively. Furthermore, when the current load was increased from 1 to 30 A g^–1, 74.5% capacitance retention was observed for the Co(OH)₂@p-rGO/NF electrode, indicating its outstanding high-power capability, while the Co(OH)₂/NF electrode retained only 38.5% of its initial capacitance. The fabricated Co(OH)₂@p-rGO/NF//rGO/NF ASC device shows an areal capacitance of 3.29 F cm⁻², cycling retention of 91.2% after 4500 cycles at 5 A g⁻¹ and energy density of 68.7 W h kg⁻¹ at a power density of 895 W kg⁻¹. The results of electrochemical tests prove that Co(OH)₂@p-rGO/NF exhibits good performance as a positive electrode for use in an asymmetric supercapacitor device. The prepared porous composite electrode is thus a promising candidate for use in supercapacitor applications.

Fabrication mechanism of a ready-to-use Co(OH)2@p-rGO/NF electrode: (a) base generation step, (b) electrophoretic deposition of rGO onto NF and (c) chemical formation of Co(OH)2 on rGO.