Interpretation of low-level Plasmodium infection rates determined by ELISA for anophelines (Diptera: Culicidae) from Egyptian oases

Plasmodium infection rates determined by enzyme-linked immunosorbent assay (ELISA) were compared for Anopheles sergentii (Theobald) and An. multicolor Cambouliu in Siwa Oasis, Egypt, an area with low-level Plasmodium vivax transmission, and in Bahariya and Farafra, two other Egyptian oases which appear to be free of malaria. Initial testing indicated that 4.4% (23 of 518) and 0.8% (4 of 518) of the An. sergentii were positive for P. vivax and P. falciparum, respectively, and that 1.4% (1 of 71) of the An. multicolor were positive for P. falciparum. However, after two confirmational tests, only 1.2% (6 of 518) of the An. sergentii remained consistently positive for P. vivax. Initial ELISA absorbance was not a useful predictor of potential false positive reactions in the P. vivax assay. Paradoxically, the six ELISA-positive An. sergentii were from the two malaria-free oases. This study raises the question of whether ELISA-positive reactions for anopheline vector species provides unequivocal evidence for transmission in areas of low malaria endemicity.     

Species composition of the Anopheles gambiae complex (diptera: Culicidae) at two sites in western Kenya

At two sites in the Kisumu area of western Kenya, the species composition of the Anopheles gambiae complex was determined by analysis of ovarian polytene chromosomes. Of 1,915 females, 26.1% were An. arabiensis Patton and 73.9% were An. gambiae Giles; one arabiensis x gambiae hybrid was identified. No major differences in the proportions of An. arabiensis and An. gambiae were observed between sites or between years. The ratio of An. arabiensis/An. gambiae was 6.7:1 (n = 231) in cow-baited traps, 0.2:1 (n = 1,525) in indoor resting samples, and 0.5:1 (n = 145) in all-night human bait catches. The proportion of An. arabiensis decreased progressively from 50.0% to 8.3% (n = 1,129) during 11 wk from September to November 1987; this change was correlated negatively with night temperature and positively with temperature range. In cow-baited traps, 97.4% (n = 194) of An. arabiensis were cow-fed and 95.8% (n = 1,054) of An. gambiae from indoor resting collections were human-fed. In indoor collections, 37.2% (n = 215) of An. arabiensis were cow-fed and 23.1% (n = 26) of An. gambiae from cow traps were human-fed. This demonstrates post-blood-feeding endophily by An. arabiensis and suggests post-blood-feeding exophily by An. gambiae. Malaria infection rates were higher for An. gambiae than for An. arabiensis by a ratio of 3:1 in 1986 (by Plasmodium falciparum ELISA) and 2.3:1 in 1987 (by dissection). Despite the higher proportion of infective An. gambiae, both species in this area serve as efficient vectors through their remarkably stable contact with the human population as demonstrated by their blood feeding and resting behavior.     

Identification of cyclophilin A from human decidual and placental tissue in the first trimester of pregnancy

The protein patterns of tissue homogenates from human deciduaand placenta of first trimester pregnancies were investigated.Particular attention was paid to the low molecular weight componentsof these tissues, since substantial evidence has accumulatedthat some of these smaller proteins show a characteristic cyclicand pregnancy expression. Two specific bands were purified fromhomogenates of first trimester decidua and placenta using gelfiltration and anion exchange chromatography. These bands wereseparated by gel electrophoresis and blotting onto polyvinylidendifluoridemembrane. Partial amino acid sequencing of both proteins revealedsequences identical to human cyclophilin A. One protein wassequenced V-N-P-T-V-F-F-D-I-A-V-D-G-E-P-L-G-R-(X)-S-F-E-L-F-A-D-K-V-Pand identified as the 17 kDa isoform of cyclophilin A. The otherprotein was sequenced V-N-P-T-V-F-F-D-I-A and identified asthe 18 kDa isoform of cyclophilin A. cyclophilin A/decidua/placenta/progesterone/progesterone receptor     

Factors influencing the infection of cowpea protoplasts by cowpea mosaic virus RNA.

Protoplasts were isolated from primary leaves of cowpeas (Vigna sinensis) by a slight modification of the procedure reported (Beier and Bruening, 1975). They were inoculated with cowpea mosaic virus RNA under various conditions. The highest yield of virus from the infected protoplasts was achieved when viral RNA was incubated in 0.45 M mannitol, 0.1 M potassium phosphate, 50 μg/ml of protamine sulfate, pH 6, at room temperature, and then was mixed with protoplasts at 10° for 15 min. Sixty-five percent of the protoplasts were infected at an RNA concentration of 50 μg/ml. When protoplasts were inoculated with virions and with RNA under the same conditions, the phase of rapid increase of protoplast-associated infectivity occurred sooner and was more steep with RNA as inoculum.     

Enhancement of antibody dependent cellular cytotoxicity (ADCC) by combination of cytokines

Monoclonal antibodies (MAb) specific for tumor-associated antigens (TAA) can induce an immunological cellular attack of tumor cells by a process termed antibody dependent cellular cytotoxicity (ADCC). Cytokines may augment ADCC by direct activation of immune cells or by enhancement of TAA on tumor cells. Thus, we investigated whether ADCC by MAb 17-1A and BR55-2, which recognize TAA on colorectal tumor cells, can be augmented by 3-day incubation with different concentrations of IL-2, IL-4, IL-6, IL-12, IFN-alpha, IFN-gamma, GM-CSF, M-CSF, and TNF-alpha. ADCC was assessed by a new flowcytometric cytotoxicity assay (Flieger et al. Immunol Methods 1995; 180:1-13) using PKH-2 labeled HT29 cells as targets and PKH-26 labeled peripheral blood mononuclear cells from three healthy volunteers as effector cells. We found three reaction patterns with the cytokines tested: (a) cytokines, which increase ADCC (IL-2, IL-12, IFN-alpha, and IFN-gamma, which represent Thl cytokines); (b) cytokines with no effect (GM-CSF, M-CSF, and TNF-alpha); and (c) cytokines, which decrease ADCC (IL-4 and IL-6, which represent Th2 cytokines). Then, we tested cytokines that increase ADCC in combination with the other cytokines. We found that the combinations IL-2/IFN-alpha, IL-2/IFN-gamma, IL-2/IL-12, and IL-12/IFN-alpha potentiated ADCC. By contrast, IL-4 reduced the IL-2, IL-12, and IFN-alpha-induced ADCC. Since the Thl response, cooperation of monocytes and CD4 cells is involved, we plan to elucidate by magnetic cell sorting (MACS) separation techniques, which cells are involved in cytokine-induced ADCC. Our results may be useful for finding combinations of cytokines and MAb for the locoregional treatment of colorectal cancer.     

Präimplantation und Implantation

Ohne Zusammenfassung     

S-100beta protects cultured neurons against glutamate- and staurosporine-induced damage and is involved in the antiapoptotic action of the 5 HT(1A)-receptor agonist, Bay x 3702

The serotonin (5-HT)(1A) receptor agonists have already been shown to protect cultured neurons from excitotoxic as well as from apoptotic damage [B. Ahlemeyer, J. Krieglstein, Stimulation of 5-HT(1A) receptors inhibits apoptosis induced by serum deprivation in cultured neurons from chick embryo, Brain Res. 777 (1997) 179-186. ; B. Ahlemeyer, A. Glaser, C. Schaper, I. Semkova, J. Krieglstein, The 5-HT(1A) receptor agonist, Bay x 3702, inhibited apoptosis induced by serum deprivation in cultured neurons, Eur. J. Pharmacol. 370 (1999) 211-216.; J.H.M. Prehn, M. Welsch, C. Backhauss, J. Nuglisch, F. Ausmeier, C. Karkoutly, J. Krieglstein, Effects of serotonergic drugs in experimental brain ischemia: evidence for a protective role of serotonin in cerebral ischemia, Brain Res. 630 (1993) 110-120.; I. Semkova, P. Wolz, J. Krieglstein, Neuroprotective effect of 5-HT(1A) receptor agonist, Bay x 3702, demonstrated in vitro and in vivo, Eur. J. Pharmacol. 359 (1998) 251-260.; B. Suchanek, H. Struppeck, T. Fahrig, The 5-HT(1A) receptor agonist, Bay x 3702, prevents staurosporine-induced apoptosis, Eur. J. Pharmacol. 355 (1998) 95-101.] and to increase the release of the neurotrophic protein, S-100beta [P.M. Whitaker-Azmitia, R. Murphy, E.C. Azmitia, Stimulation of astroglial 5-HT(1A) receptors releases the serotonergic growth factor, protein S-100, and alters astroglial morphology, Brain Res. 497 (1989) 80-86. ; P.M. Whitaker-Azmitia, R. Murphy, E.C. Azmitia, S-100 protein is released from astroglial cells by stimulation of 5-HT(1A) receptors, Brain Res. 528 (1990) 155-158.]. In this study, we tried to find out whether S-100beta can protect cultured neurons from glutamate- and staurosporine-induced damage and whether the neuroprotective activity of the highly selective 5-HT(1A) receptor agonist, Bay x 3702, is mediated by an induction of S-100beta. Extracellularly added S-100beta (1-10 ng/ml) reduced staurosporine-induced damage in pure neuronal cultures from chick embryo telencephalon as well as in mixed neuronal/glial cultures from neonatal rat hippocampus. In addition, S-100beta (1 ng/ml) reduced neuronal death induced by exposure to glutamate (0.25 mM, 30 min) in mixed neuronal/glial cultures from neonatal rat hippocampus. In cultured rat cortical astrocytes, a 24 h-treatment with Bay x 3702 (1 nM) increased the S-100beta content in the culture medium from 2.2+/-0.3 (controls) to 6.2+/-0.7 ng/ml. In the adult rat, a 4 h-infusion of 4 microg/kg Bay x 3702 (i.v.) was found to increase the S-100beta content in the striatum 6 h after the beginning of the infusion to 153+/-37 microg/g compared with 60+/-20 microg/g in vehicle-treated rats. Bay x 3702 had no effect on the S-100beta content in the rat hippocampus. Finally, we tried to block the protective effect of Bay x 3702 against staurosporine-induced damage in mixed neuronal/glial cultures from rat neonatal hippocampus by anti-S-100beta antibodies. We found only a partial blockade, although the antibodies fully blocked the antiapoptotic effect of S-100beta itself demonstrating that the antibody was effective in blocking neuroprotection by S-100beta. Thus, we conclude that S-100beta was able to protect cultured neurons against glutamate- and staurosporine-induced damage. Furthermore, S-100beta mediated partially the protective effect of the 5-HT(1A) receptor agonist, Bay x 3702, against staurosporine-induced apoptosis in mixed neuronal/glial cultures from neonatal rat hippocampus.     

Accessing diabetes care in rural Uganda: Economic and social resources

Non-communicable diseases including type 2 diabetes (T2D) are increasing rapidly in most Sub-Saharan African (SSA) countries like Uganda. Little attention has been given to how patients with T2D try to achieve treatment when the availability of public health care for their disease is limited, as is the case in most SSA countries. In this paper we focus on the landscape of availability of care and the therapeutic journeys of patients within that landscape. Based on fieldwork in south-western Uganda including 10 case studies, we explore the diabetes treatment options in the area and what it takes to access the available treatment. We analyse the resources patients need to use the available treatment options, and demonstrate that the patients’ journeys to access and maintain treatment are facilitated by the knowledge and support of their therapy management groups. Patients access treatment more effectively, if they and their family have money, useful social relations, and knowledge, together with the capacity to communicate with health staff. Patients coming from households with high socio-economic status (SES) are more likely to have all of these resources, while for patients with low or medium SES, lack of economic resources increases the importance of connections within the health system.