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1.
The biosurfactant glycolipid complex synthesized by Rhodococcus ruber actinobacteria is not toxic and exhibits no appreciable effect on proliferative activity of peripheral blood leukocytes. In the monocyte fraction, the biosurfactant activates the production of IL-1β and TNF-α cytokines without modifying the production of IL-6. In the mononuclear fraction, the glycolipid biosurfactant exhibited no effects on the production of IL-1β, TNF-α, and IL-6. These results indicate good prospects for further studies of immunomodulating and antitumor activities of biosurfactant drug. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 9, pp. 301–305, September, 2007  相似文献   

2.
A novel niosome formulation is proposed for topical drug delivery of ammonium glycyrrhizinate, a natural compound with an efficacious anti-inflammatory activity. Niosomes were made up of a new non ionic surfactant, α,ω-hexadecyl-bis-(1-aza-18-crown-6) (Bola-surfactant)-Span 80-cholesterol (2:3:1 molar ratio). Niosome vesicles were prepared with the thin layer evaporation method and were physico-chemically characterized. The tolerability of Bola-surfactant both as free molecules or assembled ion niosome vesicles was evaluated in vitro on cultured of human keratinocyte cells (NCTC2544). Human tolerability was evaluated on volunteers. The ability of Bola-niosomes to promote intracellular delivery was evaluated by confocal laser scanning microscopy (CLSM) studies. Human stratum corneum and epidermis (SCE) membranes were used in vitro to investigate the percutaneous permeation. The anti-inflammatory activity of ammonium glycyrrhizinate was evaluated in vivo on human volunteers with a chemically induced erythema. Experimental data show that Bola-niosomes are characterized by a mean size of ∼400 nm and are able to provide an encapsulation efficiency of 40% with respect to the drug amount used during preparation. CLSM showed that Bola-niosomes were able to promote the intracellular uptake of the delivered substances. Bola-niosomes were also able to significantly improve (p <0.001) the percutaneous permeation of ammonium glycyrrhizinate with respect to both the aqueous drug solution and a physical mixture between unloaded Bola-niosomes and the aqueous drug solution. Bola-niosomes showed a suitable tolerability both in vitro and in vivo. Ammonium glycyrrhizinate-loaded Bola-niosomes determined a significant (p <0.001) and noticeable improvement of the in vivo anti-inflammatory activity of the drug. An effective example of conjugating innovative colloidal carriers, coming from pharmaceutical nanotechnology, and therapeutically effective natural compounds, coming from traditional medicine, was reported. Part of this research was presented at the 33rd Annual Meeting of the Controlled Release Society in Vienna, Austria, July 22–26, 2006.  相似文献   

3.
Thyroliberin is a neuropeptide with marked respiratory activity. The neuronal mechanisms underlying this activity were addressed in experiments on transverse slices of brainstem from adult rats in conditions of membrane potential clamping to study effect effects of thyroliberin (10 nM) on the potassium A-current in neurons of two areas of the respiratory center — the ventrolateral areas of the solitary tract nucleus and the pre-Betzinger complex. The A-current, seen in all study neurons in the respiratory center, was partially and reversibly blocked by thyroliberin. A significant reduction in the amplitude of the current was accompanied by an increase in the inactivation constant. The effect of thyroliberin on the amplitude of the A-current was analogous to that of 5 mM 4-aminopyridine. These results show that the stimulatory effects of thyroliberin at the level of respiratory center neurons is at least partly explained by its ability to block the potassium A-current.Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 89, No. 12, pp. 1560–1568, December, 2003.  相似文献   

4.
The Reelin (Reln)-deficient mouse (reeler) and the Dab1-deficient mouse (yotari) are autosomal recessive mutant mice characterized by cerebellar ataxia. Previously, we reported that Reelin and Dab1 proteins have slightly different functions during the development of the cerebral cortex. To analyze the functional roles of Reelin and Dab1 proteins in detail, we attempted to generate a reelin/Dab1 compound-mutant mouse by breeding heterozygote reeler and yotari mice. We examined the cytoarchitecture of the cerebral and cerebellar cortices and the hippocampus of wild-type (Reln +/+ ; Dab1 +/+ ), double-heterozygote (Reln rl/+ ; Dab1 yot/+ ), reeler (Reln rl/rl ; Dab1 +/+ , Reln rl/rl ; Dab1 yot/+ ), yotari (Reln +/+ ; Dab1 yot/yot , Reln rl/+ ; Dab1 yot/yot ), and double-compound-deficient (Reln rl/rl ; Dab1 yot/yot ) mice. Nissl staining demonstrated that no abnormality was recognized in the mice of reelin/Dab1 double-heterozygote (Reln rl/+ ; Dab1 yot/+ ). The reelin/Dab1-compound mutant mouse (Reln rl/rl ; Dab1 yot/yot ) showed histological abnormalities in the cerebral and cerebellar cortices and the hippocampus, in addition to those of reeler and yotari mice. We injected HRP into the lumbar cord of these animals with various gene compositions to examine the distribution pattern of corticospinal tract (CST) neurons. CST neurons of the reelin/Dab1-compound mutant mice were not confined to layer V, but scattered throughout the motor cortex. This quantitative and statistical analysis shows that the distribution pattern of CST neurons of the reelin/Dab1-compound mutant mouse differs from those of either of the reeler or yotari counterparts. Taken together, although Reelin/Dab1 signal transduction is a primary cascade in neurons during developmental periods, other signaling cascades (e.g., the Cdk-5/Dab1 pathway) may lie in a parallel fashion to Reelin/Dab1 signal transduction.  相似文献   

5.
We have located and cloned the Anticarsia gemmatalis multicapsid nucleopolyhedrovirus isolate 2D (AgMNPV-2D) genomic DNA fragment containing the immediate early 1 ORF and its flanking regions. Computer assisted analysis of the complete ie1 locus nucleotide sequence information was used to locate regulatory signals in the upstream region and conserved nucleotide and amino acid sequences. Comparative studies led to the identification of several characteristic protein motifs and to the conclusion that AgMNPV-2D is more closely related to Choristoneura fumiferana defective NPV than to other Group I nucleopolyhedrovirus. We have also shown that the AgMNPV IE1 protein was able to transactivate an early Autographa californica MNPV promoter and its own promoter in transient expression assays. In order to investigate the biological functionality of the ie1 promoter, the ie1 upstream activating region (UAR) was molecularly dissected and cloned upstream of the E. coli lacZ ORF. The results obtained, after transfection of UFL-AG-286 insect cells, leading us to find that the −492 and −357 versions contains sequence motifs important for the level of the lacZ reporter gene expression. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. The GenBank accession number of the sequence reported in this paper is AF368905.  相似文献   

6.

Background  

Nitric oxide-releasing nonsteroidal antiinflammatory drugs (NO-NSAIDs) are reported to be safer than NSAIDs because of their lower gastric toxicity. We compared the effect of a novel NO-releasing derivate, NCX 4040, with that of aspirin and its denitrated analog, NCX 4042, in in vitro and in vivo human colon cancer models and investigated the mechanisms of action underlying its antitumor activity.  相似文献   

7.
Galba truncatula snails were experimentally infected with either of two different isolates of Fasciola gigantica, originating from Egypt or China, to determine the influence of these isolates on the characteristics of snail infections. The survival rates of G. truncatula on day 30 post-exposure were 90.0% and 60.2% in the Egyptian and Chinese groups, respectively. The frequency of cercaria-shedding snails within the Egyptian group was 79.8%, whereas in the Chinese group it was 22.4%. The parasite origin had a significant effect on the durations of the prepatent and patent periods. The mean number of cercariae shed from the Egyptian group was significantly greater than that shed from the Chinese group (a mean of 275.5 per cercaria-shedding snail compared with 29.0). These results could be explained by the fact that G. truncatula might be a natural intermediate host for F. gigantica in Egypt, and the greater adaptability of the Egyptian miracidia of F. gigantica to unusual snail hosts. These results demonstrate the influence of the geographic origin of the parasite on the success of trematodes infecting snails.  相似文献   

8.
Leishmania (Viannia) braziliensis is the major causative agent of American tegumentary leishmaniasis, a disease that has a wide geographical distribution and is a severe public health problem. The cysteine proteinase B (CPB) from Leishmania spp. represents an important virulence factor. In this study, we characterized and localized cysteine proteinases in L. (V.) braziliensis promastigotes. By a combination of triton X-114 extraction, concanavalin A-affinity, and ion exchange chromatographies, we obtained an enriched fraction of hydrophobic proteins rich in mannose residues. This fraction contained two proteinases of 63 and 43 kDa, which were recognized by a CPB antiserum, and were partially sensitive to E-64 in enzymatic assays with the peptide Glu-Phe-Leu. In confocal microscopy, the CPB homologues localized in the peripheral region of the parasite. This data together with direct agglutination and flow cytometry assays suggest a surface localization of the CPB homologues. The incubation of intact promastigotes with phospholipase C reduced the number of CPB-positive cells, while anti-cross-reacting determinant and anti-CPB antisera recognized two polypeptides (63 and 43 kDa) derived from phospholipase C treatment, suggesting that some CPB isoforms may be glycosylphosphatidylinositol-anchored. Collectively, our results suggest the presence of CPB homologues in L. braziliensis surface and highlight the need for further studies on L. braziliensis cysteine proteinases, which require enrichment methods for enzymatic detection.  相似文献   

9.
The lectin binding properties of Fasciola hepatica miracidia were studied by a panel of fluorescein- and gold-conjugated lectins (ConA, LCA, WGA, LEA, SBA, HPA and UEA-I). The presence of mannose and/or glucose residues was demonstrated with ConA and LCA as weak diffuse fluorescence of the miracidial surface, which was more intense at the anterior part of the larva. The N-acetylglucosamine-binding lectins WGA and LEA reacted intensely with the whole miracidial surface. No labelling with N-acetylgalactosamine and/or galactose-specific (SBA and HPA) and fucose-specific UEA-I lectins was observed. The possibility that the specific recognition of the miracidial surface carbohydrates by lectins may initiate the process of transformation of the miracidia into sporocysts was examined in vitro in physiological saline for Galba truncatula. Incubation in the presence of ConA and WGA resulted in facilitation of the transformation process. Facilitation was absent in the presence of inhibitor sugars. Incubation in the presence of SBA or UEA-I had no effect. The results suggested a possible impact of carbohydrate-lectin interactions in transformation of miracidia of F. hepatica to sporocysts in vivo.  相似文献   

10.
The metastatic potential of cancer cells is an elusive property that is indicative of the later stages of cancer progression. The ability to distinguish between poorly and highly metastatic cells is invaluable for understanding the basic biology of cancer and to develop more treatments. In this paper, we exploit a A375 melanoma cell line series (A375P, A375MA1, A375MA2) that vary in metastatic potential, to demonstrate an in vitro screening assay using polydimethylsiloxane (PDMS) microbubble well arrays that can distinguish these cell lines by their growth characteristics in including morphology, migratory potential, and clonogenic potential. These cell lines cannot be distinguished by their growth characteristics when cultured on standard tissue culture plastic or planar PDMS. Results show that the more metastatic cell lines (A375MA1, A375MA2) have a higher proliferative potential and a distinctive radial spreading growth pattern out of the microbubble well. The A375MA2 cell line also has a higher tendency to form multicellular spheroids. The ability to successfully correlate the metastatic potential of cancer cells with their growth characteristics is essential first step toward developing a high-throughput screening assay to identify aggressive tumor cells in primary samples. The capability to culture and recover aggressive cells from microbubble wells will enable identification of candidate metastatic biomarkers which has immense clinical significance.  相似文献   

11.
12.

Objective  

The present study was designed to investigate the role of X-ray cross-complementing group 1 (XRCC1) and apurinic/apyrimidinic endonuclease 1 (APE1) polymorphisms in apoptosis and the risk of ulcerative colitis (UC).  相似文献   

13.

Background  

The current treatment of onchocerciasis relies on the use of ivermectin which is only microfilaricidal and for which resistant parasite strains of veterinary importance are increasingly being detected. In the search for novel filaricides and alternative medicines, we investigated the selective activity of crude extracts of Margaritaria discoidea and Homalium africanum on Onchocerca ochengi, a model parasite for O. volvulus. These plants are used to treat the disease in North West Cameroon.  相似文献   

14.
The effects of Xe on cell viability and redox balance in the culture of Wistar rat thymocytes were studied in vitro during 24-h storage under hypothermic conditions. The results indicate that after bubbling of cell suspensions (5×106 cell/ml, 4 ml medium), the weight of Xe in flasks was 15–43 mg, whereas in cell-free medium no weight increment due to gas accumulation in the system was detected. The content of Xe in cell suspension slightly decreased over 24-h culturing at ambient temperature (by 10% of initial level). Xenon significantly improved cell survival during thermal exposure of all modes. The maximum cytoprotective effect of Xe was observed under rigorous thermal conditions associated with significant cell death without chemical protectors (3°C, −35°C). The effect of Xe was less pronounced at mild temperatures (23–37°C) or in the presence of chemical protectors (−35°C with dimethylsulfoxide). The mechanisms of the effect of the inert gas are determined by its antioxidant or prooxidant action. The capacity of Xe to improve cell survival under hypothermic conditions can be used for the development of new methods for transportation and storage of cell material. __________ Translated from Kletochnye Tehnologii v Biologii i Medicine, No. 2, pp. 74–77, April, 2007  相似文献   

15.
Lemuricola (Madoxyuris) bauchoti Chabaud, Brygoo et Petter, 1965 is redescribed from material collected from the ring-tailed lemur, Lemur catta, from the Beza Mahafaly Special Reserve in Madagascar using the scanning electron microscope. This is a new host record and the first oxyurid reported from the ring-tailed lemur. Previously, records of each species of the subgenus Madoxyuris have been restricted to a single host species, but the close relationship between these nematodes and their Strepsirrhini hosts will only be proven when additional records fill in the gaps in their distribution.  相似文献   

16.
Pseudomonas aeruginosa is an opportunistic pathogen of immunocompromised hosts. In cystic fibrosis (CF), P. aeruginosa causes acute and chronic lung infections that result in significant morbidity and mortality. P. aeruginosa possesses several traits that contribute to its ability to colonize and persist in acute and chronic infections. These include high resistance to antimicrobials, ability to form biofilms, plethora of virulence products, and metabolic versatility. In P. aeruginosa, a cell-to-cell communication process termed quorum sensing (QS) regulates many of these factors that contribute to its pathogenesis. Recent evidence suggests that the CF lung environment presents a specialized niche for P. aeruginosa. The relationship of P. aeruginosa QS, biofilm formation, and the CF lung environment is discussed.  相似文献   

17.
We describe the case of a 62-year-old patient with fever and abdominal pain of the right upper quadrant with a known history of adenocarcinoma of the colon and presence of hepatic metastases. One of the liver lesions underwent aspiration, and pus was sent for microbiological testing. Cultures of the pus were positive for Klebsiella pneumoniae and Candida albicans and polymerase chain reaction for Mycobacterium tuberculosis was concurrently positive; the patient received treatment for all three pathogens and improved clinically. One may consider searching not only for the usual pathogens of liver abscesses (gram-negative bacteria, anaerobic bacteria and gram-positive bacteria), but in special cases might consider pursuing a more detailed search for coexistence of fungi and mycobacteria in patients with cancer.  相似文献   

18.
19.
The aims of the present study were to establish an adequate excystment method for metacercariae of Paramphistomum spp. and to compare the in vitro survival of paramphistomids in three different culture media. In a preliminary study, 31 different assays were performed solely with the purpose of obtaining the best percentage of metacercariae excystment. Once the best excystment method was selected, 21 further assays using 100 metacercariae/assay were carried out to determine the average percentage of excystment. For the in vitro culture of paramphistomids, the Hedon-Fleig, Rohrbacher, and RPMI-1640 culture media were compared by using 24-well immunoplates containing newly excysted flukes or 50-ml capacity tissue-culture flasks for adult paramphistomids. Results indicated an average of 69.0% excystment, the best culture medium to support the survival of immature and adult stages of the trematode being Hedon-Fleig and Rohrbacher, respectively. The best percentage of survival obtained was on day 4 (80%), with some immature and adult trematodes remaining alive until days 10 and 11, respectively.  相似文献   

20.
Repeat induced point mutation (RIP) is a gene silencing mechanism present in fungal genomes. During RIP, duplicated sequences are efficiently and irreversibly mutated by transitions from C:G to T:A. For the first time, we have identified traces of RIP in transposable elements of Aspergillus niger and Penicillium chrysogenum, two biotechnologically relevant fungi. We found that RIP in P. chrysogenum has affected a large set of sequences, which also contain other mutations. On the other hand, RIP in A. niger is limited to only few sequences, but literally all mutations are RIP-like. Surprisingly, RIP occurred only in transposon sequences that have disrupted open reading frames in A. niger, a phenomenon not yet reported for other fungi. In both fungal species, we identified two sequences with strong sequence similarity to Neurospora crassa RID. RID is a putative DNA methyltransferase and the only known enzyme involved in the RIP process. Our findings suggest that both A. niger and P. chrysogenum either had a sexual past or have a sexual potential. These findings have important implications for future strain development of these fungi.  相似文献   

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