Specific studies on schistosome gene functions require both access to the parasite stages, preferably the larvae, and to complete the life cycle. In the present study, we investigated whether short-term in vitro cultivation of sporocysts and surgical transplantation into snails could be combined to produce cercariae. Miracidia were maintained in vitro in the presence of Biomphalaria glabrata embryonic (Bge) cells or, alternatively, in Bge-cell-conditioned medium. The transformation of miracidia to mother sporocysts was observed in both cases. Two day-old sporocysts were transplanted into the cephalopedal sinus of recipient snails. Transplantation efficiencies varied between 16% and 43%, depending on the culture of the sporocysts in terms of the number of cercariae producing snails. Cercariae recovered from these snails were used to successfully infect hamsters, demonstrating that short term in vitro-generated sporocysts undergo normal cercariogenesis following transplantation. This combination of in vitro cultivation and transplantation may be useful for novel experimental approaches to investigate the genes involved in larval development or host-parasite molecular interactions. 相似文献
CD95 is a major apoptosis receptor that induces caspase activation and programmed cell death in susceptible cells. CD95-induced apoptosis can be blocked by peptidic caspase inhibitors such as benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone or Ile-Glu-Thr-Asp-fluoromethyl ketone. Here we show that stimulation of CD95 in the presence of these inhibitors induces necrosis and expression of various proinflammatory cytokines in primary T lymphocytes, such as TNF-alpha, IFN-gamma and granulocyte/macrophage colony-stimulating factor. In the absence of caspase inhibition CD95 stimulation did not result in cytokine expression, indicating that this proinflammatory signaling pathway is suppressed by active caspases. Further analysis with A3.01 T cells revealed that the proinflammatory signaling activity of CD95 was mediated by MEK/ERK, p38 and NF-kappaB signaling pathways. These findings point to a pivotal role of caspases not only as mediators of apoptosis but also as enzymes that prevent proinflammatory signaling during CD95-induced apoptosis. Moreover, our findings may be useful for the development of novel pharmacological strategies. 相似文献
In the pentastomidRaillietiella aegypti the structure of the genital apparatus and of oogonia, previtellogenic and vitellogenic oocytes was studied by light and electron microscopy. The ovarian wall consists of a single-layered epithelium covered by a basement membrane of varying thickness. The ovary is characterized by numerous, lateral, sac-like evaginations in which the oocytes lie.Centrioles indicate mitotic activities in oogonia. In previtellogenic oocytes the ooplasm is poor in organelles, containing only a few mitochondria and rough endoplasmic reticulum, but many free ribosomes. In vitellogenic oocytes there is a rapid multiplication of mitochondria and a proliferation of the rough endoplasmic reticulum. The cytoplasm also contains cortical vacuoles, yolk spheres, dictyosomes and pinocytotic vesicles. The mitochondria lie in one big cluster and combine to the Balbiani body (=yolk nucleus). Two types of yolk spheres differing in morphological details are formed in the oocytes ofR. aegypti. 相似文献
In heat-treated polyamide 6 and polyamide 6,6 fibres UV/VIS-active chromophores are found, which originate from two different sources: one type of chromophore (structured UV spectrum) arises during polycondensation and the spinning of the fibres (molten phase), the other (nonstructured UV spectrum) occurs as a result of a thermo-oxidation is based on conjugated oligoenimies , as is shown by a combination of UV/VIS spectroscopy and fluorescence excitation and emission spectroscopy with chemical analysis. The concentration of the various oligoenimine species depends upon the temperature and duration of the thermooxidation. For a temperature of 160°C and a duration of 2 hours, for example, the following oligoenimine concentrations were found (UV spectroscopy with computer-aided evaluation): for i = 0: 44; i = 1: 13; i = 2: 4; i = 3: 1; i = 4: 0,3 (values expressed in mmol/kg). 相似文献
Background: Opioids can produce peripheral analgesic effects by activation of opioid receptors on sensory nerves. This study was designed (1) to examine a novel route of opioid administration, the intraperitoneal injection; (2) to compare this to interpleural application, and (3) to compare opioid with local anesthetic effects under both conditions.
Methods: At the end of laparoscopic cholecystectomy, 110 patients received the following injections in a double-blind, randomized manner: Group 1 (n = 18) was given intraperitoneal morphine (1 mg in 20 ml saline) and 20 ml intravenous saline. Group 2 (n = 17) received intraperitoneal saline and 1 mg intravenous morphine. Group 3 (n = 15) received 20 ml 0.25% intraperitoneal bupivacaine and intravenous saline. Group 4 (n = 20) received interpleural morphine (1.5 mg in 30 ml saline) and 30 ml intravenous saline. Group 5 (n = 20) received interpleural saline and 1.5 mg intravenous morphine. Group 6 (n = 20) received 30 ml 0.25% interpleural bupivacaine and intravenous saline. Postoperative pain was assessed using a visual analog scale, a numeric rating scale, and the McGill pain questionnaire. Pain localization, supplemental analgesic consumption, vital signs, and side effects were recorded for 24 h.
Results: Neither intraperitoneal nor interpleural morphine produced significant analgesia after laparoscopic cholecystectomy (P > 0.05, Kruskal-Wallis test), whereas interpleural bupivacaine was effective (P < 0.05, Kruskal-Wallis test, up to 6 h postoperatively) but not intraperitoneal bupivacaine (P > 0.05, Kruskal-Wallis test). Shoulder pain was not prevalent in the majority of patients during the first 6 h. By 24 h, about half of the patients complained of shoulder pain, which was rated "low" by about one-third of all patients. No significant side effects occurred. 相似文献
Temporary electrical stimulation using anal or vaginal electrodes and an external pulse generator has been a treatment modality for urinary urge incontinence for nearly three decades. In 1981 Tanagho and Schmidt introduced chronic electrical stimulation of the sacral spinal nerves using a permanently implanted sacral foramen electrode and a battery powered pulse generator for treatment of different kinds of lower urinary tract dysfunction, refractory to conservative treatment. At our department chronic unilateral electrical stimulation of the S3 sacral spinal nerve has been used for treatment of vesi-courethral dysfunction in 43 patients with a mean postoperative follow up of 43,6 months. Lasting symptomatic improvement by more than 50 % could be achieved in 13 of 18 patients with motor urge incontinence (72,2 %) and in 18 of the 21 patients with urinary retention (85,7 %). Implants offer a sustained therapeutic effect to treatment responders, which is not achieved by temporary neuromodulation. Chronic neuromodulation should be predominantly considered in patients with urinary retention. Furthermore in patients with motor urge incontinence, refusing temporary techniques or in those requiring too much effort to achieve a sustained clinical effect. Despite high initial costs chronic sacral neuromodulation is an economically reasonable treatment option in the long run, when comparing it to the more invasive remaining therapeutic alternatives. 相似文献
Background: Hypopyon-uveitis has been identified as a dosage-dependent side effect in patients with acquired immunodeficiency syndrome
who are treated for Mycobacterium avium complex (MAC) infection with systemic rifabutin.
Patients and methods: We report a 38-year-old female AIDS patient with bilateral hypopyon uveitis under therapy with rifabutin in combination with
clarithromycin and indinavir.
Results: At the time of presentation of the bilateral hypopyon uveitis the patient was treated with rifabutin (300 mg/day), clarithromycin
(1000 mg/day) and ethambutol (1000 mg/day) for an M. avium complex infection. Also, the patient received the protease inhibitor indinavir. The rifabutin dose was reduced to 150 mg/day.
Hypopyon and inflammation resolved under therapy with steroids.
Conclusions: The concomitant use of rifabutin, clarithromycin, and protease inhibitors may lead to hypopyon uveitis. Reduction of dosage
of rifabutin (150 mg/day) and treatment with topical steroids are required.
相似文献
Summary The effects of i.v. molsidomine administration on the coronary circulation, myocardial oxygen consumption, and haemodynamics were studied in open-chest dogs with non-constricted coronary arteries, and compared to those of nitroglycerin and isosorbide dinitrate. Molsidomine (50, 100, 250 g/kg) reduced coronary flow while nitroglycerin (5, 10, 20 g/kg) and isosorbide dinitrate (50, 100, 250 g/kg) augmented coronary flow indicating coronary dilatation. Coronary resistance remained unaffected by molsidomine but fell after both nitrates. Molsidomine decreased myocardial oxygen consumption whereas nitroglycerin and isosorbide dinitrate initially increased oxygen consumption followed by a reduction. A decrease in stroke work was calculated after all three drugs. Minute work fell after molsidomine and nitroglycerin but not after isosorbide dinitrate.Heart rate and contractility remained unchanged by molsidomine but were both significantly enhanced by both nitrates. Stroke volume and cardiac output fell after molsidomine but increased immediately after both nitrates when administered with a subsequent decrease. Peripheral resistance was unchanged by the low dose of molsidomine but significantly decreased by the two nitrates immediately after administration indicating precapillary vasodilatation. The fall in blood pressure after molsidomine followed the reduction in cardiac output as sequel of lowered preload and venous return to the heart. The same mechanism decreased heart work after both nitrates but in addition vasodilatation of the coronary arteries and arterial vessel occurred.The effects of the three compounds are mainly the consequence of extracardiac effects, i.e. increased capacity of postcapillary vessels (molsidomine) plus arteriolar vasodilatation of short (nitroglycerin) and long duration (isosorbide dinitrate), respectively. Whereas molsidomine exerts no effects on the heart and coronary circulation both nitrates dilate coronary arteries and change heart performance thus indicating direct effects on the entire heart. 相似文献
Summary Chromatographic analysis of 3,5-cyclic nucleotide phosphodiesterase (PDE) isoenzymes in the cytosol of human neutrophils shows the predominant presence of PDE IV (cAMP specific) and PDE V (cGMP specific). PDE IV is characterized by (1) cAMP selectivity, (2) a KM for cAMP of 1.2 M and (3) a typical rank order of IC 50-values for PDE inhibitors: 0.13, 0.17, 47 and 9.5 M for PDE IV selective rolipram, PDE III/IV selective zardaverine, PDE III selective motapizone and unselective 3-isobutyl-l-methylxanthine (IBMX), respectively. Functions of polymorphonuclear leukocytes (PMN) such as N-formylmethionyl-leucyl-phenylalanine (fMLP)-stimulated superoxide release and fMLP/thimerosal elicited leukotriene (LT) biosynthesis are inhibited by these PDE inhibitors with the same rank order and even lower IC50-values. Measurements of changes in cytosolic Cai in Fura-2 loaded PMN demonstrate a transient Cai increase after stimulation with 0.1 M fMLP and an additional sustained elevation of Cai levels in the presence of thimerosal. PDE inhibitors suppress this sustained phase of Cai release with the same rank order of IC50-values as LT biosynthesis. The correlation between fMLP/thimerosal-induced LT biosynthesis and Cai levels reveal a Cai threshold of 150 nM for arachidonic acid metabolism. cAMP levels in PMN were elevated by PDE inhibitors alone by less than 2-fold. In the presence of fMLP however, cAMP was increased up to 10-fold and the efficacy of PDE inhibitors to increase cAMP paralleled their potency to inhibit PDE IV. It is concluded that (1) suppression of PMN functions is achieved by PDE IV inhibition, (2) necessary cAMP elevations are within 50% increase, (3) superoxide release was affected by cAMP/protein kinase A (PKA) directly whereas (4) for inhibition of LT biosynthesis a cAMP related reduction of Ca-influx is involved.
Send offprint requests to Ch. Schudt at the above address 相似文献