Granulocyte-Macrophage Colony-Stimulating Factor and Tumor Necrosis Factor Alpha in Patients with Human Immunodeficiency Virus (HIV) Type 1 Infection

Variations in cytokine production in patients with human immunodeficiency virus (HIV) infection could be involved in the physiopathology and in the progression of the disease. Therefore we studied the level of granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor α (TNFα) produced in patients with HIV infection at stage II (asymptomatic seropositives) and stage IV (AIDS) of the CDC classification, by using an enzyme amplified sensitivity immunoassay. We measured the level of GM-CSF and TNFα in supernatant of phytohemagglutinin-activated peripheral blood mononuclear cells from patients and healthy individuals. In one out of 10 stage II patients and 4 out of 14 stage IV patients, we obtained higher levels of GM-CSF than the mean + 2 S.D. of controls, but in 3 stage IV patients with very low CD4+ T lymphocyte counts (< 50/mm^–3) compared to other patients, the GM-CSF values were very low. High levels of TNFα were detected in 3 out of 10 stage II and 6 out of 11 stage IV patients. The high values of TNFα were associated with high values of GM-CSF in stage II and in most of AIDS patients except those with very low CD4⁺ T cell counts, who produced low levels of GM-CSF. Plasma levels of cytokines were evaluated in 10 stage II, 22 stage IV patients and 20 controls. Increased levels of GM-CSF (more than 9 pg/ml) were observed in the plasma from 8 out of 10 stage II patients and 17 out of 22 stage IV patients. The tendency that increased levels of GM-CSF were associated with increased levels of TNFα was observed in plasma from stage IV patients. We report a disarray of GM-CSF production in patients with HIV infection that could be involved in clinical manifestations and progression of the disease.     

Efficiency of various selective media in determining Pythium population in soil

Of 15 selective media recommended for isolation and enumeration ofPythium spp. directly from soil, corn meal agar (CMA) supplemented with agar, sucrose, minor elements, thiamine, rose bengal, pimaricin, pentachloronitrobenzene and vancomycin (MPVM) was the most efficient. Streptomycin (30–50 ppm) and rose bengal (33–60 ppm) as used in certain tested media effectively suppressed development of bacteria and actinomycetes. However, these chemicals adversely affected germination of spores and mycelial growth and thereby the recovery ofPythium spp. from soil. Media containing pimaricin (5 to 100 ppm) were more effective than those with nystatin (40 ppm) in suppressing development of nonphycomycetous fungi on isolation plate. MPVM with pimaricin at 5 ppm was more efficient than that with 10 ppm of the antibiotic in recoveryingPythium from soil. However, there was no difference in recovery ofPythium by this medium containing rose bengal at 5 ppm or at 10 ppm, butPythium colonies were more dense and better delineated when the medium contained 10 ppm of rose bengal. CMA containing pimaricin (5–100 ppm) and vancomycin (200 ppm) permitted occasionally development of a large number ofMortierella and bacterial colonies from certain soils, that interfered with accurate determination of colonies of certainPythium spp. on the plates. Vancomycin at 300 ppm, as used in MPVM, substantially reduced development of bacterial colonies compared to 200 ppm of the antibiotic. Surface-soil dilution-plate was more effective than the soil-dilution-plate method in reducing bacteria andMortierella colonies on isolation plates without affecting recovery ofPythium. The importance of basal medium, complement of antimicrobial agents, and isolation methods for efficiency of selective medium in recovery ofPythium spp. directly from soil is discussed.     

Evidence of Airborne Excretion of Pneumocystis carinii during Infection in Immunocompetent Rats. Lung Involvement and Antibody Response

To better understand the role of immunocompetent hosts in the diffusion of Pneumocystis in the environment, airborne shedding of Pneumocystis carinii in the surrounding air of experimentally infected Sprague Dawley rats was quantified by means of a real-time PCR assay, in parallel with the kinetics of P. carinii loads in lungs and specific serum antibody titres. Pneumocystis-free Sprague Dawley rats were intratracheally inoculated at day 0 (d0) and then followed for 60 days. P. carinii DNA was detected in lungs until d29 in two separate experiments and thereafter remained undetectable. A transient air excretion of Pneumocystis DNA was observed between d14 and d22 in the first experiment and between d9 and d19 in the second experiment; it was related to the peak of infection in lungs. IgM and IgG anti-P. carinii antibody increase preceded clearance of P. carinii in the lungs and cessation of airborne excretion. In rats receiving a second challenge 3 months after the first inoculation, Pneumocystis was only detected at a low level in the lungs of 2 of 3 rats at d2 post challenge and was never detected in air samples. Anti-Pneumocystis antibody determinations showed a typical secondary IgG antibody response. This study provides the first direct evidence that immunocompetent hosts can excrete Pneumocystis following a primary acquired infection. Lung infection was apparently controlled by the immune response since fungal burdens decreased to become undetectable as specific antibodies reached high titres in serum. This immune response was apparently protective against reinfection 3 months later.     

Velocity profiles in stenosed tube models using magnetic resonance imaging

A time-of-flight MRI velocity measurement technique is evaluated against corresponding LDV measurements in a constriction tube model over a range of physiologic flow conditions. Results from this study show that MR displacement images can: 1) be obtained within both laminar and turbulent jets (maximum stenotic Re approximately equal to 4,200), 2) measure mean jet velocities up to 172 cm/s, and, 3) detect low forward and reverse stenosis (0 less than or equal to L/D less than or equal to 2). Regions between the jet termination point and re-establishment of laminar flow (Re greater than or equal to 1500, greater than or equal to 1000, and greater than or equal to 110 downstream of 40, 60, and 80 percent stenosis, respectively) cannot presently be detected by this technique.     

Study of morphological and cytological parameters indicating oestrus in Lemur fulvus mayottensis

Lemur fulvus mayottensis females were presented each day to vasectomized males. A simultaneous study of parameters of vaginal smears, external genital organs, and the cervix was carried out on the same females. Results from the two methods allow the determination of oestrus, that is, the best period for artificial insemination.     

Ontogeny,maturation and plasticity of the olfactory system in the workerbee

The ontogeny and maturation of the olfactory system in the workerbee have been studied using a combination of neurophysiological (first order neurones) and neuroanatomical techniques (second order neurones). EAG recordings show that normal maturation of the olfactory response takes place during the first 4 days following emergence, and is closely related to the sensory environment during the same period. The synaptic organization of first order and second order neurones of the antennal afferent pathway (analyzed at the level of the glomeruli in the deutocerebrum) is essentially complete three days before emergence. These results are discussed in relation to a possible role of the sensory environment during the period from 3 days before until 8 days after emergence.