In vitro inhibition of the growth of Gardnerella vaginalis by bacteriocins produced by strains of Pseudomonas aeruginosa

BACKGROUND: Pseudomonas aeruginosa with inhibitory capacity in vitro was studied on Gardnerella vaginalis strains. METHODS: Antimicrobial activity was demonstrated by inhibitory halos of bacterial growth on solid media by two methods: crossed streak and agar well diffusion. The inhibitory activity of this substance produced by P. aeruginosa was characterized as bacteriocin by: activity spectrum sensitivity proteolytic enzyme, chloroform, heat, pH, ultraviolet, irradiation effect and molecular weight. RESULTS: Four strains of P. aeruginosa producers of bacteriocins were chosen for this study and contacted with 40 strains of G. vaginalis. The producing strain D inhibited 70% of these G. vaginalis strains. The strains B and C inhibited 55% and 52.5%, respectively. The 3 strains presented a wide rank of action but the strain A had effect on a few strains of G. vaginalis. CONCLUSIONS: This work showed the inhibitory in vitro effect of bacteriocins of P. aeruginosa on strains of G. vaginalis. The results obtained suggest the probable topic application of bacteriocins as an alternative of conventional therapeutic on this infection biological control.     

Acquisition of iron by Gardnerella vaginalis

Six Gardnerella vaginalis strains were examined for the ability to utilize various iron-containing compounds as iron sources. In a plate bioassay, all six strains acquired iron from ferrous chloride, ferric chloride, ferrous sulfate, ferric ammonium citrate, ferrous ammonium sulfate, bovine and equine hemin, bovine catalase, and equine, bovine, rabbit, and human hemoglobin. All six strains also acquired iron from human lactoferrin, but not from human transferrin, as determined by a liquid broth growth assay. Siderophore production was detected in eight G. vaginalis strains by the chrome azurol S universal chemical assay. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the cytoplasmic membrane proteins isolated from G. vaginalis 594 grown under iron-replete and iron-restricted conditions revealed several iron-regulated proteins ranging in molecular mass from 33 to 94 kDa. These results indicate that G. vaginalis may acquire iron from iron salts and host iron compounds.     

In vitro effect of tinidazole and furazolidone on metronidazole-resistant Trichomonas vaginalis

Trichomonas vaginalis is a common sexually transmitted protozoan parasite. Although often considered simply a nuisance infection, T. vaginalis has been implicated in premature rupture of placental membranes and increases in the risk of acquiring human immunodeficiency virus. Metronidazole, a 5-nitroimidazole, is currently the drug of choice to treat T. vaginalis infection. Because some patients have severe reactions to metronidazole and others are infected with metronidazole-resistant T. vaginalis, we were prompted to investigate alternative therapies. Tinidazole, another 5-nitroimidazole used in other countries to treat T. vaginalis infections, and furazolidone, a nitrofuran presently used to treat giardiasis and infections with some anaerobic enteric bacteria, were investigated for effectiveness against 9 metronidazole-susceptible and 12 metronidazole-resistant T. vaginalis patient isolates. The in vitro aerobic and anaerobic minimum lethal concentrations (MLC) and the time for drug efficacy were determined. Tinidazole killed the metronidazole-susceptible isolates at a low MLC but was effective against only 4 of the 12 metronidazole-resistant isolates. In contrast, furazolidone was effective at a low MLC for all isolates. When tinidazole was effective, it required > 6 h to kill trichomonads. However, furazolidone killed both metronidazole-susceptible and resistant trichomonads within 2 to 3 h of exposure. These data suggest that furazolidone may be a good candidate for treating metronidazole-resistant trichomoniasis and that further investigation of this drug is warranted.     

Prevalence of Gardnerella vaginalis in prepubertal males

Polymeric hydrophilic matrices are widely used for controlled-release preparations. The process of drug release is controlled by matrix swelling or polymer dissolution. It has been shown that the swelling of guar gum is affected by concentration of drug and viscosity grade of the polymer. This study examines the mechanism of behavior of guar gum in a polymer-drug matrix. The swelling action of guar gum, in turn, is controlled by the rate of water uptake into the matrices. An inverse relationship exists between the drug concentration in the gel and matrix swelling. This implies that guar gum swelling is one of the factors affecting drug release. The swelling behavior of guar gum is therefore useful in predicting drug release.     

Colposcopy images of cervix in women with Gardnerella vaginalis infection

Among micro-organisms infecting vagina whose dominant genus is GV anaerobic bacteria are often present. There are reports that GV infections of vagina and uterine cervix, apart from their well-known negative role in obstetrics practice can play a role in carcinogenic processes of uterine cervix. The aim of the study was to assess characteristic colposcopy images of cervix in women with Gardnerella vaginalis infection. The research was carried out on 1180 women hospitalised in the period of 14 months. Many observations lead to conclusions that pathognomic clinic feature of Gardnerella vaginalis infection of uterine cervix is visible in colposcope presence of clean, translucent mucus in external cervical os and opaque vaginal contents in the rear vaginal vault. High hydrogen ion concentration in vaginal contents (pH 6.0 and over) correlates with positive "fishy odour test" of this contents. Gardnerella vaginalis infection of vagina and uterine cervix concerns women with existing erosion-type changes of uterine cervix. Visible in colposcopic test restless and "spotted" images visible after Schiller test are pathognomic colposcopic features of Gardnerella vaginalis infection.     

Pathogenic potential of Gardnerella vaginalis on the female urogenital system

The prevalence of certain characteristics of genital discharge like (a) watery variety in sexually transmitted disease (STD) clinic 34% and in gynaecology clinic 26.6%, (b) fishy odour in STD clinic 29.2% and in gynaecology clinic 12.2% and (c) pH > 4.5 in STD clinic 53.6% and in gynaecology clinic 43% was notable. On the other hand, occurrence of "clue cells" (in STD clinic 41.4% and in gynaecology clinic 39.5%) did not show difference in the aforesaid clinics. The preponderance of watery discharge in the STD clinic appears to be related to G vaginalis (in STD clinic 26.8% and in gynaecology clinic 9.3%). It is intriguing to note that G vaginalis was isolated from leucorrhoea (in STD clinic 19.5% and in gynaecology clinic 9.3%) and inapparent (in 10%) cases and normal (in 4.2%) cases. Single infection with G vaginalis in one particular case had profuse watery discharge, pH > 4.5 and there was occurrence of "clue cells". Likewise, in multiple infections revealing G vaginalis (29 cases) as one of the potential agents, 78.5% had profuse, 53.8% watery discharge of which 53.5% had "clue cells" and 81% had pH > 4.5. In mixed type of infections, the U urealyticum (53.8%) and M hominis (30.6%) were conspicuous in bacterial vaginosis. Cervicitis, erosion cervix or urethral syndrome were unrelated to G vaginalis. All cases of G vaginalis infection responded to metronidazole with remission of leucorrhoea in 25.9% cases.     

A study on the in vitro susceptibility of Trichomonas vaginalis to metronidazole

The susceptibility of 32 clinical isolates of Trichomonas vaginalis to metronidazole has been studied under aerobic and anaerobic conditions. Of 32 patients with vaginal trichomoniasis, 27 (84%) were cured by a standard metronidazole treatment regimen (200 mg thrice daily for seven days). The geometric means of minimum inhibitory concentration (MIC) under aerobic and anaerobic conditions for these isolates were 2.0 and 0.4 micrograms/ml, respectively; the geometric means of minimum lethal concentration (MLC) under aerobic and anaerobic conditions were 7.4 and 2.0 micrograms/ml, respectively. However, for those five patients with treatment failure, the geometric means of MIC for these isolates under aerobic and anaerobic conditions were 6.8 and 1.1 micrograms/ml, respectively; the geometric means of MLC under aerobic and anaerobic conditions were 18 and 5.5 micrograms/ml, respectively. Trichomonads reisolated from patients after treatment failure had similar susceptibility to metronidazole as before treatment. However, all five women were cured by a second course of metronidazole treatment. Although primary treatment failure was common when isolates of T. vaginalis had aerobic MLC values of > 18 micrograms/ml or anaerobic MLC values > 5.5 micrograms/ml, two cases with isolates having high MLC values (aerobic: 20 micrograms/ml, anaerobic: 5 micrograms/ml) responded well to the standard treatment. It was evident that no metronidazole-resistant trichomonads were found in this study.     

In vitro and in vivo growth inhibition of cancer cells by adamantylmaleimide derivatives

We have previously found that adamantylmaleimide derivatives inhibited the growth of several cancer cell lines in vitro. In this study we examined the effect of adamantylmaleimide derivatives on the in vivo and in vitro growth of human gastric cancer cells. Experimental results showed that N-1-adamantylmaleimide (AMI) and N-1-(3,5-dimethyladamantyl)maleimide (DMAMI) exert modest growth inhibitory activities in vitro against five different cancer cell lines. In contrast, N-1-(3,5-dimethyl-adamantyl)maleamic acid (DMAMA), N-1-adamantylmaleamic acid (AMA) and N-1-adamantylsuccinimide (ASI) were virtually inactive. These results suggest that the double bond of N-substituted maleimide plays a prominent role in their antitumor activities. Further analysis with flow cytometry showed an accumulation of apoptotic SC-M1 cells after treatment with 3-10 microM AMI or 5-20 microM DMAMI for up to 72 h. DNA fragmentation by gel electrophoresis confirmed that AMI- and DMAMI- induced cytotoxicity led to cell apoptosis. In addition, scanning electron microscopy (SEM) showed that treating cells with AMI (> or = 10 microM) for 24 h, significantly changed the morphology of SC-M1 cells, i.e. they had an irregular flat shape and the cell membrane was porous. The AMI-induced morphological changes of the cell membrane may lead to apoptosis of SC-M1 cells. AMI-induced growth inhibition was observed in vivo using SCID mice bearing SC-M1 tumors. The AMI-induced growth inhibition of SC-M1 tumor was dose-dependent.     

Deactivation of macrophage oxidative burst in vitro by different strains of Histoplasma capsulatum

It was previously reported that Histoplasma capsulatum (Hc) yeast not only failed to stimulate a murine macrophage oxidative burst (OB), but they also blunted or abolished OB stimulation by a subsequent encounter with potent stimuli such as zymosan or phorbol 12-myristate 13-acetate (PMA). The present studies show that macrophage deactivation is proportional to the time of incubation and the dose of Hc yeast that induce the deactivated state. Hc yeast derived from a virulent strain (G217B) are more efficient inducers of macrophage deactivation than similar preparations derived from the avirulent Downs Hc strain. Yeast cells of two other pathogenic fungi, Candida albicans and Cryptococcus neoformans are shown to stimulate rather than deactivate a macrophage OB.     

In vitro inhibition of microbial methane production by 9,10-anthraquinone

Monensin, 2,2-dichloroacetamide, and 9,10-anthraquinone were incubated for 24 h in ruminal fluid and buffer with 100:0, 50:50, and 10:90 forage-concentrate diets. Monensin (.5 ppm of the fluid) increased (P < .05) the molar proportion of propionate in the 50 and 100% forage diets but not in the high concentrate diet. At the same level of addition, 2,2-dichloroacetamide increased (P < .05) the molar proportion of propionate only in the 50:50 forage-concentrate diet. Relative to control cultures, monensin and 2,2-dichloroacetamide numerically decreased methane production in the 10 and 100% forage diets and decreased (P < .05) methane in the 50% forage diet. Hydrogen production was unaffected by treatment. Lack of an effect on fermentation end products in the high concentrate diet was probably a result of the low dose levels. In general, increasing levels of 9,10-anthraquinone (.5, 1.0, and 5.0 ppm) reduced total VFA concentration and the molar proportion of acetate, and increased propionate, butyrate and valerate. Increasing levels of 9,10-anthraquinone caused linear and quadratic decreases (P < .05) in methane production, and increases (P < .05) in hydrogen. There were no consistent effects on ammonia concentration in culture fluid from any of the compounds. In continuous culture of a 10:90 forage-concentrate diet, addition of 9,10-anthraquinone (10 ppm of the fluid/12 h) caused changes similar to those observed in batch culture with the exception of a decreased (P < .05) molar percentage of propionate, which may have been due to the high dose. The data are interpreted to indicate that 9,10-anthraquinone has the ability to alter in vitro microbial fermentation.     

紫花牡荆素体外抑制人宫颈癌HeLa细胞增殖的研究

Objective: The aim of the study was to investigate the effect of Casticin on proliferation inhibition of human cervical cancer HeLa cells in vitro and to unravel the associated mechanisms. Methods: Human cervical HeLa cells were cultured in vitro. The inhibitory effect of Casticin on the viability of human cervical cancer HeLa cells was evaluated by the MTT assay.The colony formation ability was detected by plate colony formation assay. Distribution of cell cycle was analyzed by flow cytometry. The protein expression levels were analyzed by Western blot. Results: Casticin significantly inhibited the growth of human cervical cancer HeLa cells in a dose- and time-dependent manner, and the IC50 was 2.82 μg/mL. The colony-forming rate was reduced drastically compared with control group (P ＜ 0.05). The cells were markedly arrested at G2/M phase after the treatment of Casticin for 48 h. Western blot showed that the expression of p21 protein was up-regulated and protein level of Cyclin B1 was depressed by Casticin in a concentration dependent manner. Conclusion: Casticin could inhibit the cell growth and lead to cell arrest in human cervical cancer HeLa cells, and the down-regulation of Cyclin B1 protein expression and activation of p21 protein might contribute to Casticin induced cell arrest in human cervical cancer HeLa cells.     

Interspecies differences in enzymes reacting with organophosphates and their inhibition by paraoxon in vitro

1 Inhibition of cholinesterases (ChE) and carboxylesterases (CaE) by paraoxon (Px) was studied in vitro in the serum, liver, lung and muscle of mouse, guinea pig, rabbit and man (serum only). Moreover, the role of Px hydrolyzing enzyme (Pxase) in the detoxification of Px was studied by inhibiting its activity with EDTA. 2 The ChE and CaE activities as well as their sensitivity to Px varied in different tissues and species. The ChEs were more sensitive than CaEs to Px except in the liver. The CaE activity in human and rabbit sera was low and resistant to Px, indicating that it may have a minor importance for the binding of Px. 3 The Px-inhibited ChEs were spontaneously reactivated in the mouse and rabbit sera during 24 h. In mouse, also the CaE activity was recovered. The presence of EDTA in the incubation medium prevented this reactivation indicating that Pxase takes part in the reactivation process. 4 In rabbit, the serum Pxase activity was very high suggesting a good Px detoxifying capacity of the rabbit serum. 5 The results show that amounts and sensitivities of esterases to OPs in rodents may markedly differ from that in man. Possible species-related differences in the affinity of ChEs and CaEs for OPs and the OP hydrolyzing activity should be taken into the consideration, when animal data are extrapolated to man.     

Acoustic startle and prepulse inhibition in 40 inbred strains of mice.

A high-throughput phenotype screening protocol was used to measure the acoustic startle response (ASR) and prepulse inhibition (PPI) in mice. ASRs were evoked by noise bursts; prepulses for PPI were 70 dB sound pressure level tones of 4, 12, and 20 kHz. Forty inbred strains of mice were tested (in most cases using 10 males and 10 females of each strain). The data on both the ASR and PPI had high internal and test-retest reliability and showed large differences among inbred strains, indicative of strong genetic influences. Previously obtained measures of hearing sensitivity in the same inbred strains were not significantly correlated with ASR or PPI measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Growth of virulent and avirulent Mycobacterium tuberculosis strains in human macrophages

Mycobacterium tuberculosis H37Rv causes progressive disease in animals, whereas the H37Ra strain does not. The relevance of this difference in virulence to human infection is uncertain because these strains have been shown to have similar growth rates in human macrophages. To evaluate the intracellular growth of M. tuberculosis strains in macrophages under conditions similar to those encountered in vivo, we infected human monocyte-derived macrophages with H37Ra, H37Rv, or one of four isolates from tuberculosis patients at a low bacillus-to-macrophage ratio. H37Rv and the patient isolates grew significantly faster than H37Ra, based on the numbers of CFU and acid-fast bacilli. These findings did not result from extracellular mycobacterial growth, differential macrophage viability, or bacillary clumping. In contrast to other published results, these findings indicate that the virulence characteristics of M. tuberculosis strains in animal models are relevant to human tuberculosis infection.     

Cytokines promote glomerular mesangial cell survival in vitro by stimulus-dependent inhibition of apoptosis

Resolution of glomerular inflammation requires the removal of proliferating resident glomerular mesangial cells, but excessive loss of glomerular cells is a feature of postinflammatory scarring. Because apoptosis regulates mesangial cell number in glomerular inflammation, we have studied the exogenous control of apoptosis triggered in cultured mesangial cells by stimuli likely to be important in vivo. Apoptosis could be induced by serum deprivation to model decreased availability of survival factors, by etoposide as an example of DNA-damaging agents, by ligation of mesangial cell Fas, and by protein synthesis inhibition by cycloheximide. Insulin-like growth factor I (IGF-I), IGF-II, and basic fibroblast growth factor were each able to suppress apoptosis induced by serum deprivation, whereas TGF-beta 1, epidermal growth factor, and platelet-derived growth factor had no effect. IGF-I and IGF-II (but not basic fibroblast growth factor) were also able to protect cells from apoptosis induced by etoposide or cycloheximide. However, Fas-mediated apoptosis was resistant to suppression by all three cytokines. None of the cytokines tested caused a change in the levels of expression of Bcl-2, Bax, Bcl-x, or Bak proteins. The survival-promoting properties of serum-free medium conditioned by mesangial cells was abrogated by neutralizing IGF-I Ab. These experiments are the first to define cytokines that inhibit apoptosis and thereby promote survival of mesangial cells, and the data indicate a paracrine survival signaling role for IGF-I. Finally, the data show that Fas ligation can override cytokine survival signaling, emphasizing a candidate role for this molecule in the undesirable apoptotic loss of mesangial cells during the progression of glomerular scarring.     

Kinetic characterization of CYP2E1 inhibition in vivo and in vitro by the chloroethylenes

Trans- and cis-1,2-dichloroethylene (DCE) isomers inhibit their own metabolism in vivo by inactivation of the metabolizing enzyme, presumably the cytochrome P450 isoform, CYP2E1. In this study, we examined cytochrome P450 isoform-specific inhibition by three chloroethylenes, cis-DCE, trans-DCE, and trichloroethylene (TCE), and evaluated several kinetic mechanisms of enzyme inhibition with physiological models of inhibition. Trans-DCE was more potent than cis-DCE, and both were much more effective than TCE in inhibiting CYP2E1. The kinetics of in vitro loss of p-nitrophenol hydroxylase (pNP-OH) activity (a marker of CYP2E1) in microsomal incubations and of the in vivo gas uptake results were most consistent with a mechanism in which inhibition of the metabolizing enzyme (CYP2E1) was presumed to be related to interaction of a reactive DCE metabolite with remaining substrate-bound, active CYP2E1. The kinetics of inhibition by TCE, a weak inhibitor in vitro, were very different from that of the dichloroethylenes. With TCE, parent compound concentrations influenced enzyme loss. Trans-DCE was a more potent inhibitor of CYP2E1 than cis-DCE based on both in vivo and in vitro studies. Quantitative differences in the inhibitory properties of the 1,2-DCE isomers may be due to the different stability of epoxides formed from bioactivation by CYP2E1. Epoxide intermediates of DCE metabolism, reacting by water addition, would yield dialdehyde, a potent cross-linking reagent.     

In vitro activity of metronidazole alone and in combination with clotrimazole against clinical isolates of Trichomonas vaginalis

The impetus for shorter hospital stay of mother and newborn infant after delivery is based on economic constraints and parental preference. Earlier published studies did not demonstrate any increase in morbidity rate with shorter stay, but these studies were limited by methodologic flaws and biases that limited the validity and generalizability of the conclusions. More recent studies showed that readmission rates increased with shorter stay and that the severity of illness of readmitted infants may have increased. In addition, the interpretation of current newborn screening tests may not be applicable when performed prior to early discharge. In light of recent changes in neonatal hospital length of stay, a careful review and update of current guidelines and practices for newborn care are required.