A model for the study of the optical transmission dynamics of liquid crystals dispersions under the influence of an electric field.

In this paper, mathematical models are developed to correlate the time-resolved optical transmission experiments of liquid crystals dispersion devices under the influence of an electric field. The dispersion of liquid crystal in the confining matrices is supposed to be composed of identical spherical microdroplets containing the nematic liquid crystal phase. It is proposed that the confining surface induces the formation of a gradient of the torsional molecular velocities (switching velocities) in the response to an electric field or relaxation by the removal of an electric field, along the radius of the liquid crystal microdroplets. A method is proposed to determine the probability density function of the switching velocities. Applying the Laplace transform, the time-dependent functions for the optical transmission behavior of the liquid crystal dispersions are obtained. The model was applied to the study of the dynamics of glass dispersed liquid crystals devices, showing good correlation with the experimental data.

Medicinal plants in the Mediterranean area: synthesis of the results of the project Rubia.

AIM OF STUDY: Within the scope of the European project RUBIA (ICA3-2002-10023), research has been performed on the traditional use and handling of plant species in several Mediterranean countries, Albania, Algeria, Cyprus, Egypt, Italy, Morocco, and Spain. This paper synthesises the chief results related to the medicinal utilization of those plants. MATERIAL AND METHODS: The information has been gathered by means of semi-structured interviews (1256) and techniques of participant observation with 803 informants. In each of the participating countries the study areas were selected by means of uniform criteria defined at the beginning of the study. RESULTS AND CONCLUSIONS: A total of 985 species have been catalogued, of which 406 have medicinal use. This work constitutes the first comparative study performed with ethnobotanical data gathered by a coordinated methodology in the Mediterranean area. An exhaustive list is provided for the species catalogued, indicating the regions where each plant was mentioned. ETHNOPHARMACOLOGICAL RELEVANCE: This information underlines the ethnobotanical richness of the region and the need to broaden this study to other areas of the Mediterranean. Furthermore, this constitutes a base for future phytochemical and pharmacological studies which could lead to new therapeutic products.

Structured treatment interruption in chronically HIV-1 infected patients after long-term viral suppression.

OBJECTIVE: To investigate the virological and immunological impact of a structured treatment interruption (STI) in a cohort of HIV-1 chronically infected patients with a further long-lasting effective virus suppression. METHODS: Twelve HIV-1 chronically infected adults who had maintained viral suppression (< 20 copies/ml) for more than 2 years, as well as a CD4:CD8 ratio > 1 for a median time of 22 months, were included in the study. Participants interrupted their antiretroviral treatment during a maximum period of 30 days or until a viral load rebound > 3000 copies/ml was detected. The same prior antiretroviral regimen was resumed after STI. Kinetics of plasma viral rebound was evaluated every 2 days during the treatment interruption period. Flow cytometry and cell proliferation assays were performed before and after STI. Genotypic resistance was assessed at the time of treatment resumption. RESULTS: No adverse events occurred during the interruption period. In two patients no viral rebound was detected after 30 days of treatment interruption. In the remaining 10 patients, viral load became detectable (> 20 copies/ml) at a median time of 14 days after treatment interruption. Afterwards, viral load increased exponentially with a mean t1/2 of 1.6 days. Treatment was successfully resumed in all patients. No resistance-conferring mutations associated with the pre-interruption antiretroviral regimen were detected. The percentage of CD4 and CD8 lymphocytes did not vary during the STI period; however, the level of expression of T-cell activation antigen CD38 on CD8 T cells increased significantly in response to viral rebound. Four patients gained T-helper cell responses to recall antigens (tuberculin and tetanus toxoid), two of who developed an HIV-specific response to p24. CONCLUSIONS: STI in chronically HIV-1-infected patients is not associated with reductions in CD4 T lymphocytes or to clinical complications in this group of patients after 2 years of effective plasma viral suppression. Viral load rebounds in most but not all patients, without evidence of selection of resistance-conferring mutations. Thereafter, viraemia can be effectively controlled by antiretroviral agent reintroduction. HIV-specific T-helper cell responses may be achieved after one cycle of treatment interruption suggesting some degree of immune-stimulation. These data do not discard consecutive cycles of STI as a therapeutic strategy to boost HIV-specific immunity in order to maintain viral replication under effective control.

Efficacy of low-dose subcutaneous interleukin-2 to treat advanced human immunodeficiency virus type 1 in persons with

The immunologic efficacy of low-dose recombinant interleukin-2 (rIL-2) administered subcutaneously (sc) once a day in combination with highly active antiretroviral therapy (HAART) was assessed in a pilot study in patients with advanced human immunodeficiency virus (HIV) disease. Twenty-five persons with 24 weeks were randomly assigned to receive sc rIL-2 (3 x 10(6) IU once a day) with their previous antiretroviral regimen (n=13) or to continue with the same treatment (n=12). The level of CD4 T cells was significantly higher in the IL-2 group at week 24 (105+/-65/microL; P<.05) but not in the control group (30+/-78/microL). Memory T cells initially contributed to the CD4 T cell increase at week 4 (P<.05). Naive T cell increases (99+/-58/microL) in the IL-2 group became statistically significant at week 24 compared with the control group (28+/-27/microL; P<.05). Subcutaneous rIL-2 once a day in combination with HAART was well tolerated and improved immunologic surface markers in patients with advanced HIV infection.

Impact on the immune system of undetectable plasma HIV-1 RNA for more than 2 years.

OBJECTIVE: To investigate the impact of prolonged HIV suppression on the immune system by analysing the expression of several lymphocyte surface markers in a group of HIV-1-infected patients who maintained undetectable HIV-1 RNA levels for more than 24 months. PATIENTS AND METHODS: The study included a highly selected group of nine HIV-1-infected asymptomatic subjects and seven HIV-1-seronegative controls. The inclusion criteria of HIV-1-infected patients was to have plasma HIV-1 RNA levels below 20 (1.3 log10) copies/ml for at least 24 months while under antiretroviral treatment with nucleoside analogues. The patient population was retrospectively taken from a cohort of 1418 treated subjects. Mean initial absolute CD4+ T-cell count and percentage were 468+/-234 x 10(6)/l (range, 202-935 x 10(6)/l) and 25+/-6% (range, 16-33%), respectively. Plasma HIV-1 RNA quantification was determined using a standard and ultrasensitive reverse transcriptase polymerase chain reaction assay. Median HIV-1 RNA plasma level before antiretroviral treatment was 3.14 log10 copies/ml (range, 1.74-3.73 log10 copies/ml). Two or three-colour immunophenotyping was performed on whole blood and frozen peripheral blood mononuclear cells by flow cytometry. RESULTS: A significant increase was noted in CD4+ lymphocyte counts at the end of the study in HIV-1-positive patients. In addition, the CD4: CD8 ratio rose significantly with respect to baseline, although it remained lower than in the controls. CD45RA+ and CD45RO+ population percentages did not differ between groups. A significant rise in CD45RA+ T cells was observed. Analysis of T-cell activation measuring the expression of human leukocyte antigen-DR and CD25 did not differ between groups. The proportion of CD8+ lymphocytes that were CD28+ was similar in both groups at the end of the follow-up. T-cell receptor Vbeta subfamily analysis showed that an expansion of the T-cell receptor repertoire might occur in these patients. CONCLUSION: Patients who maintain undetectable viral load for prolonged periods of time with antiretroviral therapy may achieve a partial immune restoration of the immune system. Our results suggest that treatment of patients at early stages of HIV infection is warranted.

Toxoplasma IgG. & IgM. antibodies. A case control study.

This study includes 62 cases of spontaneous abortions and 75 cross matched non pregnant multiparous women as controls. Micro-ELISA test was done to measure Toxoplasma IgM & IgG antibodies. Out of 62 aborting women, 26 gave positive anti-Toxoplasma IgG antibodies, more than 45 Eu/ml and 28 gave positive anti-Toxoplasma IgM antibodies, more than 40 Eu/ml without statistical significant difference. There was a significant difference between aborting women and the controls as regards IgG & IgM antibodies. IgG antibodies, showed statistical significant difference between those with no history of abortions or I-2 abortions versus those with 3 or more abortions. The infection was more among aborting women in rural than urban areas whom suffered poor hygienic measures and awareness about the mode of transmission of Toxoplasma infection. The results were discussed.

Transplacental transfer of schistosomal antigens and antibodies.

Circulating S. mansoni soluble antigens (CSA) and antibodies (CAB) were investigated in sera of 32 S. mansoni-infected pregnant mothers, their 32 newborns and 26 non-pregnant infected women. CSA levels in pregnant mothers and their newborns were significantly higher than in the 3rd group. Also, a significant positive correlation was detected between the CSA levels in sera from infected mothers and the cord blood of their newborns proving the transplacental transfer of these antigens. On the other hand, CAB levels were significantly higher in the 3rd group than in the mothers and their newborns and this could be explained by the immune complexes formation. No schistosome eggs or worms were detected in placentas and the possibility of congenital schistosomiasis was eliminated.

Effect of juvenile hormone on Musca domestica vicina Macq. II. The gonotrophic cycle.

The effect of the topical application of the synthetic juvenile hormone JH-I on adult specimens of Musca domestica vicina Macq was studied. The adult stage responded to different JH-I concentrations in different ways. The gonotrophic cycle was shortened, the number of eggs decreased and the hatching rate was reduced. The adults of the next generation displayed a number of anomalies. The ovarian amino acid concentrations varied considerably according to the dose of JH-I and the stage of maturation of the relevant ovary.

Psychological functioning of bipolar manic-depressives in remission.

Several dimensions of psychological functioning of bipolar manic-depressives in remission were investigated. The following hypotheses were examined: (1) During remission, these individuals exhibit psychological maladjustment or a lack of positive mental health. (2) Bipolar manic-depressives are characterized by strong external orientations. The Personal Orientation Inventory, Marlowe-Crowne Social Desirability Scale, Levenson's Internal and Powerful Others Locus of Control Scales, and the Embedded Figures Test were administered to matched groups of 35 bipolar manic-depressives and 35 normal comparison subjects. Discriminant analysis disclosed no significant differences between the two groups on measures of positive mental health and on measures of external orientation. The relationship between these results and the etiology and treatment of manic-depressive disorder is briefly discussed, as well as the contradiction these findings pose to current views of this disorder pervasive among professional and lay populations.