High activation and skewed T cell differentiation are associated with low IL-17A levels in a hu-PBL-NSG-SGM3 mouse model of HIV infection.

The humanized NOD/SCID/IL-2 receptor γ-chainnull (NSG) mouse model has been widely used for the study of HIV pathogenesis. Here, NSG mice with transgenic expression of human stem cell factor (SCF), granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-3 (NSG-SGM3) were injected with peripheral blood leukocytes (PBL mice) from two HIV-infected (HIV+ ) patients who were under anti-retroviral therapy (ART; referred as HIV+ mice) or one HIV-seronegative healthy volunteer (HIV- ). Such mice are either hu-PBL-NSG-SGM3 HIV+ or HIV- mice, depending on the source of PBL. The kinetics of HIV replication and T cell responses following engraftment were evaluated in peripheral blood and secondary lymphoid tissues. High HIV replication and low CD4 : CD8 ratios were observed in HIV+ mice in the absence of anti-retroviral therapy (ART). Consistent with high activation and skewed differentiation of T cells from the HIV-infected donor, HIV+ mice exhibited a higher T cell co-expression of human leukocyte antigen D-related (HLA-DR) and CD38 than HIV- mice, as well as a shifted differentiation to a CCR7- CD45RA+ terminal effector profile, even in the presence of ART. In addition, HIV replication and the activation/differentiation disturbances of T cells were associated with decreased plasma levels of IL-17A. Thus, this hu-PBL-NSG-SGM3 mouse model recapitulates some immune disturbances occurring in HIV-infected patients, underlying its potential use for studying pathogenic events during this infection.

Agricultural and Physiological Responses of Tomato Plants Grown in Different Soilless Culture Systems with Saline Water under Greenhouse Conditions.

Tomato is the most important horticultural crop in the world. The yields for this crop are highest in Southeastern Spain. In this work we studied a commercial variety of tomato, with different soilless culture systems (deep flow technique, nutrient film technique, and the perlite substrate) and three levels of salinity (2.2, 6.3, and 10.2 dS·m-1) typical of Southeastern Spain. The irrigation management was carried out for optimizing the water use efficiency. Alterations in the water status of the plants, Cl- and Na+ toxicity, and nutritional imbalances altered the vegetative growth and physiology of the plants. The marketable yield was affected by both soilless culture system and salinity. Regarding the soilles culture system, yield decreased in the order: deep flow technique > perlite > nutrient film technique. The salinity treatments improved the fruits quality by increasing the total soluble solids and titratable acidity. Plants cultivated with the nutrient film technique had the highest concentrations of Cl- and Na+ and the highest Na+/K+ ratio. The concentrations of Cl- and Na+ in the plants were not related directly to the yield loss. Therefore, the influence of the toxicity, osmotic effect, and nutritional imbalance seems to have been responsible for the yield loss.

A method to determine the in-air spatial spread of clinical electron beams.

We propose and analyze in detail a method to measure the in-air spatial spread parameter of clinical electron beams. Measurements are performed at the center of the beam and below the adjustable collimators sited in asymmetrical configuration in order to avoid distortions due to the presence of the applicator. The main advantage of our procedure lies in the fact that the dose profiles are fitted by means of a function which includes, in addition to the Gaussian step usually considered, a background which takes care of the dose produced by different mechanisms for which the Gaussian model does not account. As a result, the spatial spread is obtained directly from the fitting procedure and the accuracy permits a good determination of the angular spread. The way the analysis is done is alternative to that followed by the usual methods based on the evaluation of the penumbra width. Besides, the spatial spread found shows quadratic-cubic dependence with the distance to the source predicted by the Fermi-Eyges theory. However, the corresponding values obtained for the scattering power are differing from those quoted by ICRU nr. 35 by a factor of approximately 2 or larger, which requires of a more detailed investigation.

Skin to cervical epidural space distances as read from magnetic resonance imaging films: consideration of the "hump pad.".

STUDY OBJECTIVE: To measure the distances from the skin to the epidural space (DSES) of the lower cervical and upper thoracic intervertebral spaces. DESIGN: Retrospective review of films of the cervical spine as obtained by magnetic resonance imaging (MRI). SETTING: Health care facility that provides diagnosis and treatment of patients with chronic pain. MEASUREMENTS AND MAIN RESULTS: MRI sagittal films of 100 patients, who had diagnostic studies for chronic headaches and cervicobrachial radiculopathy, were reviewed. Measurements were made of DSES, the dural sac, and the spinal cord by centimeter ruler. Estimates were also made of the width of the epidural space by measuring the distance from the ligamentum flavum to the dural sac. The longest DSES were noted at C6-7 and C7-T1 levels, with a mean of 5.7 cm, but they decreased to a mean of 5.4 cm at the T1-2, and to 4. 7 cm at the T2-3 intervertebral spaces. One of the major factors in this variability was the presence of an accumulation of fatty tissue along the lower cervical and upper thoracic area, which the authors named the "hump pad." This accumulation appears to be thicker in obese patients, with a slight correlation coefficient with the patient's weight. The distances from ligamentum flavum to dural sac, representing the depth of the epidural space, averaged 0.3 cm, 0.4 cm, 0.5 cm, and 0.4 cm, respectively. CONCLUSIONS: In the cervical spine, DSES varies from space to space. In obese individuals, the fat pad may increase DSES at the lower cervical intervertebral spaces. The longest mean distances from the ligamentum flavum to the dural sac and to the spinal cord were found at the T1-2 and T2-3 levels, precisely where DSES is shorter. All things being equal, the upper thoracic intervertebral spaces appeared to provide a greater margin of safety for insertion of epidural catheters to treat cervicobrachial radiculopathies.

Regular production of infective sporozoites of Plasmodium falciparum and P. vivax in laboratory-bred Anopheles albimanus.

One of the major constraints for studies on the sporogonic cycle of the parasites causing human malaria, and on the protective efficacy of pre-erythrocytic vaccines, is the scarcity of laboratory-reared Anopheles mosquitoes as a source of infective sporozoites. The aim of the present study was to reproduce the life-cycles of Plasmodium falciparum and P. vivax in the laboratory and so develop the ability to produce infective sporozoites of these two species regularly under laboratory conditions. Colonized Anopheles albimanus, of Buenaventura and Tecojate strains, were infected by feeding either on Plasmodium-infected blood, from human patients or experimentally inoculated Aotus monkeys, or on gametocytes of the P. falciparum NF-54 isolate grown in vitro. The monkeys were infected with the blood stages of a Colombian P. vivax isolate and then, after recovery, with the Santa Lucia strain of P. falciparum from El Salvador. Although both of the mosquito strains used were successfully infected with both parasite species, the Buenaventura strain of mosquito was generally more susceptible to infection than the Tecojate strain, and particularly to infection with the parasites from the patients, who lived where this strain of mosquitoes was originally isolated. Monkeys injected intravenously with the P. vivax sporozoites produced in the mosquitoes developed patent sexual and asexual parasitaemias; the gametocytes that developed could then be used to infect mosquitoes, allowing the development of more sporozoites. However, experimental infections failed to establish after the P. falciparum sporozoites were used to inoculate monkeys. The ability to reproduce the complete life cycle of P. vivax in the laboratory, from human to mosquito and then to monkey, should greatly facilitate many studies on vivax malaria and on the efficacy of candidate malaria vaccines. The availability of the sporogonic cycles of P. falciparum from three different sources should also permit a variety of biological studies.

LCMV-mediated hepatitis in rhesus macaques: WE but not ARM strain activates hepatocytes and induces liver regeneration.

Lymphocytic chorimeningitis virus (LCMV), the prototype arenavirus, and Lassa virus (LASV), causative agent of Lassa hemorrhagic fever (LHF), belong to the Old World group of the family Arenaviridae. Both viruses have extensive strain diversity and significant variations in lethality and pathogenicity for man and experimental animals. We have shown that the LHF-like infection of rhesus macaques with the WE strain of LCMV affects liver functions, induces hepatocyte proliferation, and causes a rise in IL-6 and soluble TNF receptors (sTNFR) concomitant with a rise in viremia. The levels of IL-6 and sTNFR can serve as an additional diagnostic tool for liver involvement in pathogenesis of arenavirus infection. Mucosal inoculation of rhesus macaques with LCMV-WE can result in attenuated infection with a transient viremia and liver enzyme abnormalities. The ARM strain of LCMV shares 88% amino acid homology with WE. In contrast to LCMV-WE, ARM strain does not induce manifested disease in monkeys, does not affect liver functions, and does not induce hepatocyte proliferation. Previously we demonstrated that LCMV-ARM infection protected rhesus macaques challenged with LCMV-WE. Here we have shown that the protected animals have no signs of hepatitis and hepatocyte proliferation.

Infusiones epidurales en pacientes ambulatorios con dolor crónico

Desde 1985 hasta la actualidad, el uso del espacio epidural para la infusión de medicamentos, se ha desarrollado enormemente en diferentes campos de la medicina. En obstetricia no sólo ha permitido el alivio del dolor durante los diferentes períodos del parto, sino que también esto se lleva a cabo de tal manera que la paciente se mantiene ambulante. Su utilización en Cirugía ha permitido la expansión de dicho procedimiento en el área de la pediatría y en síndromes dolorosos agudo y crónicos oncológicos y no oncológicos, proveyendo analgesia efectiva durante los procesos agudos. Además de esta cualidad, les brinda mejor calidad de vida y una incorporación parcial o total a las actividades diarias de los pacientes con padecimientos crónicos. En la actualidad nuestra experiencia se basa en la utilización de infusiones epidurales de dosis bajas de anestésicos locales y opioides aplicados a diferentes niveles de la columna vertebral, en pacientes ambulatorios con dolor de origen no canceroso, luego que estos han sido tratados previamente con otros procedimientos sin encontrar mejoría. Es importante señalar, que los pacientes deben reunir ciertas condiciones para su elegibilidad, que van desde el diagnóstico y estudios radiológicos precisos, hasta evoluciones psicológicas. Una vez aceptado el paciente, es instruido y educado en todo lo relacionado con el tratamiento (procedimiento, contenido y control de las infusiones, complicaciones, etc) con la finalidad de satisfacer las necesidades del paciente y obtener su permiso legal. En tal forma hemos podido implantar catéteres de polietileno durante 162 días, comectados a bombas de infusión desechables y de bajo costo. Los resultados favorables obtenidos y el bajo costo de dicho procedimiento al compararlo con otros procesos más invasivos, complicados y quizás con bajo porcentaje de efectividad, ha permitido abrir nuestras mentes a otras posibles aplicaciones como litiasis renal, pancreatitis crónica intermitente, reemplazos de rodilla, etc. Igualmente es nuestro deseo que sea accesible a personas de limitados recursos económicos, brindándoles la satisfacción de vivir una vida libre de dolor físico y mental