We tested risperidone and ritanserin, serotonin-S2 receptor antagonists, for their effects on in vitro polyclonal IgG and IgM synthesis by human peripheral blood mononuclear cells (PBMC) stimulated with pokeweed mitogen (PWM). On the basis of the previously reported effect on immune function in vivo risperidone in this study was tested in three different groups of PBMC: healthy donors as well as schizophrenic patients before risperidone treatment and schizophrenic patients after the treatment with risperidone. IgG and IgM production after 7 days of culture was measured by ELISA. Risperidone decreased IgG synthesis (p<0.05) in PBMC of healthy subjects only at the highest concentration (10~6 M) and IgG synthesis enhanced by 5-HT was antagonized by risperidone. This effect, however, was not statistically significant. Neither risperidone nor ritanserin, in the concentration range 10-8- 10~6M, affected IgM synthesis in this group. Risperidone did not affect the production of IgG and IgM by PBMC of schizophrenic subjects in PWM-stimulated cultures both before and after risperidone therapy. The spontaneous production of IgG in PBMC of schizophrenic subjects before therapy was decreased (p<0.05) at concentrations 10-6-10~7 M of risperidone. We conclude that risperidone and ritanserin did not increase polyclonal IgG and IgM synthesis in vitro in contrast to neuroleptics currently used in clinical practice.
Diabetes mellitus is associated with a number of prothrombotic abnormalities, and correction of these abnormalities might translate into the reduction of cardiovascular risk. Glitazones improve endothelial function and reduce inflammation, but much less is known about their effect on thrombogenic factors. We have therefore studied the effect of rosiglitazone on leukocyte and soluble thrombogenic markers in patients with type 2 diabetes mellitus. Thirty-three subjects with type 2 diabetes and 32 normal controls were included; patients were examined at baseline and after 5 months of rosiglitazone treatment (4 mg/day). We measured leukocyte-platelet aggregates and leukocyte expression of either P-selectin glycoprotein ligand 1 (PSGL-1) or receptor for urokinase-type plasminogen activator (uPAR) using flow cytometry, as well as several circulating soluble thrombogenic markers by ELISA method. Leukocyte expression of uPAR and PSGL-1 was significantly higher in patients than in controls. Leukocyte-platelet aggregates and leukocyte expression of uPAR and PSGL-1 significantly decreased after rosiglitazone. There was also significant decrease in CRP and fibrinogen levels, but there was no effect of diabetes and/or rosiglitazone on other circulating molecules. In conclusions, we observed a substantial improvement in the expression of thrombogenic markers on leukocytes after rosiglitazone treatment, suggesting the novel antithrombotic effects of rosiglitazone., H. Svobodová ... [et al.]., and Obsahuje seznam literatury
The physiological parameters mortality, mass, oxygen consumption and amylase activity, and microanatomical features of the digestive tract, mesenchym and reproductive organs were used to characterise starvation in Galumna elimata. The mites were reared in sterilised plastic vials containing moistened zeolite at 25°C and a 12:12 photoperiod. The control group was kept under the same conditions, but pieces of bark covered with the green bark alga, Desmococcus vulgaris (syn. Protococcus viridis), were added as food for the mites. The physiological parameters were recorded after 21 days, and the microanatomical after 21 and 42 days. The guts of the starved mites were empty or filled with mucoid substances, while the guts of control mites contained food boli formed from algal cells. The mortality was significantly higher in starved animals. The mortality after 42 days of starvation was higher in males than females. The fresh mass of starved individuals significantly decreased while the water proportion content of their body tissues increased. Oxygen consumption of the starved mites was lower. Starvation did not influence the activity of amylase. Glycogeneous granulae were characteristically absent, and mucoid substances present in the guts of mites starved for 21 days. The activity of mesenteral and caecal cells, proventricular glands and cells of salivary glands was reduced after 42 days of starvation. The cells of the seminal vesicles were reduced and contained no spermatic cells in males starved for 42 days. Starved females probably resorbed immature oocytes, but had eggs in their oviducts. Starvation induces ovovivipary or larvipary in Galumna elimata.
Pine caterpillar, Dendrolimus tabulaeformis Tsai et Liu, is a major pine pest in North China. The larvae enter diapause in the third or fourth instar before winter. Supercooling points (SCP) and cold hardiness of the diapausing larvae were investigated and compared in non-acclimated, acclimated and de-acclimated larvae. A bimodal frequency distribution was observed with a break point of -14°C in the SCP. Larvae in the low group (LG, SCP <= -14°C) were more cold tolerant with lower lethal temperatures than those in the high group (HG, SCP > -14°C). This bimodality occurred in three patterns, LG (> 60% of individuals in LG), LG-HG (< 60% of individuals in LG and HG) and HG (> 60% of individuals in HG), in response to cold acclimation and de-acclimation. The cold hardiness was ranked as: LG > LG-HG > HG pattern. Cold hardiness was enhanced by an increase in concentrations of trehalose, galactose, glucose and mannose in the haemolymph as well as by decrease in metabolism after cold acclimation, but was lost after de-acclimation. Loss of cold hardiness was correlated with decrease in sugars and increase in metabolic rate. In conclusion, the species is a chill tolerant insect, adopting the strategy of depressing SCP through accumulation of low molecular weight sugars in the haemolymph, concomitant with metabolic depression.
Environmental degradation caused by climate change greatly affects the forest ecosystems of the Mediterranean region, in particular the sclerophyllous Quercus forests typical of central and southern Spain. An important pest that damages oak trees in this area is Coraebus florentinus (Herbst), a heliophilous and thermophilous insect whose survival could be favoured by the temperature increase associated with climate change. The main objective of this paper was to determine the effect of temperature on the duration and percentage survival of the preimaginal stage of C. florentinus and provide data for determining more precisely when to control for this pest by applying silvicultural techniques. The experiment included six treatments, with 25 branches infested with C. florentinus in each of the treatments, which were kept at different temperatures over the range 15–28°C. The results clearly support the hypothesis that higher temperatures affect the post-larval development of C. florentinus by increasing the percentage survival and shortening the developmental time. In fact, partial correlations confirm that the highest percentages of emergence and survival were recorded when the developmental times were shortest, which occurred at the highest temperatures used. Despite the clear influence of temperature on the development of the preimaginal stage of C. florentinus, additional trials are required to accurately determine future trends in C. florentinus populations. Accordingly, it is necessary to develop monitoring programs in zones affected by C. florentinus and to apply scheduled management techniques that ensure the control of this species., Ana M. Cárdenas, Patricia Gallardo., and Obsahuje seznam literatury
Gronotoma micromorpha is a solitary egg-pupal and larval-pupal parasitoid. In a previous study, the developmental time of this parasitoid decreased with the age of its leaf miner host, Liriomyza trifolii, being significantly longer when the host was 0-day old (= 0-24 h old egg) than when 4 days old (mature larva) at the time of parasitization at 25°C. In the present study, the suitability and acceptability of 0 and 4 day old L. trifolii as hosts for G. micromorpha, and the ovipositional preference of this parasitoid for these two developmental stages of the host were examined. No significant difference was found in the size of the parasitoid offspring that emerged from hosts parasitized at these two developmental stages. There was no significant difference in the acceptability of the two developmental stages of L. trifolii in no choice tests, but 4 day old larvae were preferred to 0 day old eggs in choice tests. Moreover, parasitization of eggs by G. micromorpha did not appear to result in more of the eggs dying before they hatched. Non-reproductive killing (host feeding and host stinging without oviposition) of host eggs by this parasitoid was also not detected.
The coccinellid Harmonia axyridis is a recent arrival in the UK and is an intraguild predator of the entomopathogenic fungus Pandora neoaphidis. Harmonia axyridis entirely consumes P. neoaphidis-sporulating cadavers and this may have a negative effect on the epizootic potential of P. neoaphidis. Here we assessed within plant transmission, and between plant vectoring, of P. neoaphidis in the presence of either H. axyridis or Coccinella septempunctata, a native coccinellid that only partially consumes fungal cadavers. Transmission was greater in the presence of coccinellids, with 21% of aphids becoming infected with the fungus whilst only 4% were infected in the control. However, there was no significant effect of coccinellid species or sex on fungal transmission. Between plant vectoring occurred infrequently in the presence of both species of coccinellid. The effect of H. axyridis on P. neoaphidis transmission is, therefore, likely to be similar to that of the native coccinellid C. septempunctata. and Patricia M. WELLS, Jason BAVERSTOCK, Michael E.N. MAJERUS, Francis M. JIGGINS, Helen E. ROY, Judith K. PELL.
A suitable host provides, at least, the minimum nutritional and physiological conditions for the development of the immature stages of a parasitoid. Host quality may influence the developmental time, mortality rate, longevity and fecundity of parasitoids. This work evaluates the suitability and quality of Aphis gossypii Glover, Brevicoryne brassicae (Linné), Myzus persicae (Sulzer), Rhopalosiphum maidis (Fitch) and Schizaphis graminum (Rondani) as hosts for Aphidius colemani Viereck. Twenty second-instar nymphs of each aphid species were exposed to parasitism for one hour, and then kept in a climatic chamber at 22 ± 1°C, 70 ± 10% RH and a 12 h photophase. The aphid B. brassicae was unsuitable for the development of A. colemani. The different aphid host species varied in size: M. persicae > (R. maidis = S. graminum) > A. gossypii. Parasitoid fitness decreased accordingly when reared on (M. persicae = R. maidis) > S. graminum > A. gossypii. Large hosts seem to be better than small hosts based on parasitoid size. Egg load of A. colemani was related probably more on the ability of the parasitoid larva to obtain nutritional resources from the different host species than on host size.
The recovery of total DNA content and recovery of total cytochrome c oxidase activity in the rat liver after partial hepatectomy is accelerated by triiodothyronine applied in three doses, two before and one immediately after liver resection. Triiodothyronine-treated animals already have higher cytochrome c oxidase activity before resection. The recovery of the tissue oxidative capacity after partial hepatectomy is more rapid in triiodothyronine-treated animals. These data indicate that hormonal activation of the liver regeneration process is involved.