Influence of contraceptive choice on vaginal bacterial and fungal microflora.

The influence of contraception on vaginal microflora can have a major impact on the risk of developing acute or recurrent vaginal infections, but also may influence the risk of acquiring sexually transmissible infections (STI) such as HIV. A cohort of 248 women presenting for levonorgestrel-releasing intrauterine system (LNG-IUS) insertion or reinsertion were stratified according to their current contraceptive method. Information concerning their menstrual pattern and data about the medical history were collected. The composition of their vaginal microflora was studied by detailed phase contrast microscopy of fresh vaginal fluid, and aerobic cultures were taken to detect enteric bacterial growth and fungal colonisation. LNG-IUS and progesterone-only-pill (POP) users had significantly lower blood loss (p < 0.001) than other women. Regardless of the type of contraception used, all women reported similar rates of symptomatic lower genital tract infection during the preceding year. Women using combined oral contraception (COC) and long-term LNG-IUS had the same bacterial composition of vaginal microflora as non-contraceptive users, even when infections were combined. Both hormonal and non-hormonal intrauterine device users had an increased tendency to have more vaginal colonisation with Candida. Women on POPs or subcutaneous implants had a tendency towards increased vaginal atrophy, but had a lower Candida carriage rate compared to IUCD users (LNG-IUS and Copper-IUCD, p = 0.037). Women with an increased risk of acquiring STIs or recurrent BV could benefit from LNG-IUS or COC due to a well-preserved vaginal bacterial flora. Women with a susceptibility for RVVC should prefer POPs, and avoid intrauterine contraception.

The effect of antifungal treatment on the vaginal flora of women with vulvo-vaginal yeast infection with or without bacterial vaginosis.

Antibacterial therapy may enhance the risk of symptomatic vulvo-vaginal candidosis in susceptible women. We addressed the question whether oral antifungal treatment for vulvo-vaginal candidosis also influences the bacterial vaginal microflora. One hundred and forty-two patients with a culture-proven acute episode of recurrent vulvo-vaginal candidosis (RVC) were treated with fuconazole according to the ReCiDiF regimen (induction dose of 600 mg orally per week followed by 200 mg per week) or with a single dose of 200 mg pramiconazole, a new potent oral triazole. At inclusion, 1 week and 1 month after the end of antifungal treatment, the bacterial microflora was assessed by microscopy of vaginal fluid to detect lactobacillary grades and bacterial vaginosis (BV). The presence of BV was studied in these patients with vulvo-vaginal candidosis after treatment with antifungal medication. At the start of oral antifungal treatment, 6.3% of women with Candida were co-infected with BV. Of the BV-negative women, 10 out of 133 (8%) developed BV after 1 week and after 1 month 8 of them (7%) were still BV-positive. Although no patients received antibacterial treatment at any moment of the study, 6 out of 9 (66%) of the women with Candida and BV at inclusion no longer had BV 1 week after antifungal treatment and 6 out of 7 (86%) lacked BV after 1 month. Treatment with antifungals may have a beneficial effect on women with concurrent BV, but does not prevent BV from occurring in BV-negative women with Candida vaginitis.

Genetically modified L3,7 and L2 lipooligosaccharides from Neisseria meningitidis serogroup B confer a broad cross-bactericidal response.

Currently available Neisseria meningitidis serogroup B (MenB) vaccines are based on outer membrane vesicles (OMVs) that are obtained from wild-type strains. They are purified with the aim of decreasing the lipooligosaccharide (LOS) content and hence reduce the reactogenicity of the vaccine even though LOS is a potential protective antigen. In <2-year-old children, these MenB vaccines confer protection only against strains expressing homologous PorA, a major and variable outer membrane protein. Our objective was to develop a safe LOS-based vaccine against MenB. To this end, we used modified porA knockout strains expressing genetically detoxified (msbB gene-deleted) L2 and L3,7 LOSs, allowing the production of LOS-enriched OMVs. The vaccine-induced antibodies were found to be bactericidal against nearly all invasive strains, irrespective of capsular serogroup. In addition, we have also demonstrated that LOS lacking the terminal galactose (with a lgtB mutation; truncated L3 LOS), but not LOS produced without the galE gene, induced a bactericidal antibody response in mice similar to that seen for LOS containing the full lacto-N-neotetraose (L3,7 LOS). In conclusion, a bivalent detoxified LOS OMV-based vaccine demonstrated the potential to afford a broad cross-protection against meningococcal disease.

Management of patients with non-atypical and atypical endometrial hyperplasia with a levonorgestrel-releasing intrauterine system: long-term follow-up.

OBJECTIVES: Levonorgestrel (LNG), delivered locally into the uterine cavity has a profound effect on the endometrium. The aim of the study was to use a LNG intrauterine system to treat non-atypical and atypical endometrial hyperplasia in women and to evaluate the long-term cure (remission) rate. METHODS: Each of the 20 women in the study, of whom eight were diagnosed with atypical hyperplasia, received a LNG-IUS, releasing 20 microg LNG/day. The study is a non-comparative study with long-term follow-up (range 14-90 months). RESULTS: All women developed a normal endometrium, except one asymptomatic woman with atypical hyperplasia who still had focal residual non-atypical hyperplasia at 3 years follow-up in the presence of a thin (< 4 mm) endometrium. CONCLUSION: Continuous intrauterine delivery of LNG appears to be a promising alternative to hysterectomy for the treatment of endometrial hyperplasia and could enhance the success rate when compared with other routes of progestagen administration as well as intrauterine progesterone delivery. The significant reduction of the PR expression observed during treatment with the LNG-IUS appears to be a marker for the strong antiproliferative effect of the hormone at a cellular level resulting in an inhibition of estrogen bioactivity and endometrial suppression.

Natural association of Gluconacetobacter diazotrophicus and diazotrophic Acetobacter peroxydans with wetland rice.

The family Acetobacteraceae currently includes three known nitrogen-fixing species, Gluconacetobacter diazotrophicus, G. johannae and G. azotocaptans. In the present study, acetic acid-producing nitrogen-fixing bacteria were isolated from four different wetland rice varieties cultivated in the state of Tamilnadu, India. Most of these isolates were identified as G. diazotrophicus on the basis of their phenotypic characteristics and PCR assays using specific primers for that species. Based on 16S rDNA partial sequence analysis and DNA: DNA reassociation experiments the remaining isolates were identified as Acetobacter peroxydans, another species of the Acetobacteraceae family, thus far never reported as diazotrophic. The presence of nifH genes in A. peroxydans was confirmed by PCR amplification with nifH specific primers. Scope for the findings: This is the first report of the occurrence and association of N2-fixing Gluconacetobacter diazotrophicus and Acetobacter peroxydans with wetland rice varieties. This is the first report of diazotrophic nature of A. peroxydans.

Hypoxia induces PMN adherence to umbilical vein endothelium.

OBJECTIVE: In vitro incubation of cultured endothelial cells under hypoxia leads to the activation of these cells and results in an increase of their adhesiveness for neutrophils (PMN). Because of the possible relevance of these observations for pathological situations, we investigated whether adherence of PMN also occurs in an entire vein after its incubation in hypoxic conditions. METHODS: Human umbilical veins in complete cords were incubated for 2 h in normoxic or hypoxic conditions and the adherence of unstimulated human 51Cr-labelled-PMN was measured under flow conditions. Experiments with human umbilical vein endothelial cells (HUVEC) were performed in parallel for comparison. Morphological studies in scanning electron microscopy were carried out in both in vitro and ex vivo situations. RESULTS: Hypoxia induced an increase in the adherence of PMN either to HUVEC or to the umbilical vein endothelium up to 5- to 6-fold when compared to normoxic conditions (P < 0.001). In both cases, this hypoxia-induced adherence was inhibited by anti-ICAM-1 antibodies or when the PAF (platelet-activating factor) synthesis was blocked during hypoxia by oleic acid. Furthermore, the adherence of PMN was inhibited when PMN were pre-incubated with WEB 2086 (a selective PAF receptor antagonist). These results indicate a crucial role of PAF in this process. Morphological studies confirmed that the number of PMN adherent to hypoxic HUVEC or to the hypoxic umbilical vein endothelium was much greater than the number of PMN on normoxic endothelial cells. Both in vitro and ex vivo, PMN adherent to the hypoxic endothelial cells to the contrary of the ones adherent to normoxic endothelial cells demonstrated membrane foldings typical of an activated state. CONCLUSION: These results show that in a complete vein, hypoxia induced an increased adhesiveness of endothelial cells for PMN by a similar mechanism to the one observed for cultured endothelial cells. They suggest an active role of endothelial cells in the initiation of the inflammatory response often described in ischemic-reperfused organs.

Use of a frameless LNG-IUS as conservative treatment for a pre-malignant uterine polyp in a premenopausal woman - a case report.

Prevention of progression to invasive carcinoma in patients with a premalignant endometrial lesion using longterm treatment with levonorgestrel (LNG) releasing intrauterine systems (IUS) remains controversial, especially when manifest cellular atypia has been found in the endometrial biopsy specimen. We present a case of a 44-year old premenopausal woman with a premalignant uterine polyp who declined hysterectomy and was followed-up for more than 12 years after the first LNG-IUS was inserted. Endometrial atrophy installed, no pathology was detected and hysterectomy was thereby successfully avoided. The positive experience in this case should encourage further studies as literature data indicate that conservative treatment of premalignant endometrial pathology is a real option with a high success rate for women who have a contra-indication for surgery, refuse the classical approach for personal reasons or want to preserve their fertility.

Effects of hydroxyethylrutosides on hypoxia-induced activation of human endothelial cells in vitro.

1. A clinically available mixture of hydroxyethylrutosides (HR) was examined as inhibitors of endothelial cell activation by hypoxia in vitro. Thus, the effects of HR on ATP depletion, phospholipase A2 activation and neutrophil adherence were investigated in hypoxia-activated human umbilical vein endothelial cells in primary cell culture. 2. Our results show that HR inhibited two important steps of the activation of endothelial cells by hypoxia: the decrease in ATP content, which is the starting point of the process, and the activation of phospholipase A2 one enzyme responsible for the release of inflammatory mediators. This inhibition was dose-dependent with 70 to 90% inhibition at 500 micrograms ml-1 of HR. 3. In addition, hypoxia-activated endothelial cells increased their adhesiveness for neutrophils. This process could also be prevented in a dose-dependent manner if endothelial cells were incubated in the presence of HR. This inhibition was confirmed by a morphological study. 4. In conclusion, the results of this study suggest that a possible explanation for the improvement in venous insufficiency by HR observed clinically could be their ability to inhibit the activation of endothelial cells during blood stasis.

Effect of venotropic drugs on the respiratory activity of isolated mitochondria and in endothelial cells.

Several drugs used in the treatment of chronic peripheral ischaemic and venous diseases, i.e. aescine, Cyclo 3, Ginkor Fort, hydroxyethylrutosides, naftidrofuryl, naphthoquinone and procyanidolic oligomers, were tested on the mitochondrial respiratory activity. The results show that all these drugs protected human endothelial cells against the hypoxia-induced decrease in ATP content. In addition, they all induced a concentration-dependent increase in respiratory control ratio (RCR) of liver mitochondria pre-incubated with the drugs for 60 min. The drugs were divided into two groups according to their effects. The first group (A), comprising aescine, Ginkor Fort, naftidrofuryl and naphthoquinone, increased RCR by decreasing state 4 respiration rate. The second group of drugs (B), comprising hydroxyethylrutosides, procyanidolic oligomers and Cyclo 3, increased RCR by increasing state 3 respiration rate. The drugs of group A were able to prevent the inhibition of complexes I and III respectively by amytal and antimycin A while the first two drugs of group B increased adenine nucleotide translocase activity. Cyclo 3 inhibited the carbonylcyanide m-chlorophenyl hydrazone (mCCP)-induced uncoupling of mitochondrial respiration. None of these seven drugs could protect complexes IV and V, respectively, from inhibition by cyanide and oligomycin. When tested on endothelial cells the drugs of group A, in contrast to group B, prevented the decrease in ATP content induced by amytal or antimycin A. The present results suggest that the protective effects on mitochondrial respiration activity by these venotropic drugs may explain their protective effect on the cellular ATP content in ischaemic conditions and some of their beneficial therapeutic effect in chronic vascular diseases.

Protection of mitochondrial respiration activity by bilobalide.

Mitochondria alteration is an early event in ischemia-induced damage, and its prevention improves tissue survival upon reperfusion. Adenine translocase and complex I activities are rapidly affected by ischemia. Ginkgo biloba extract demonstrates anti-ischemic properties attributable to the terpenoid fraction, mainly due to the presence of bilobalide. The mechanism of the protection afforded by bilobalide is not yet known. In this work, the effects of bilobalide on mitochondrial respiration were investigated. Mitochondria isolated from rats treated with bilobalide (2 to 8 mg/kg) showed a dose-dependent increase in the respiratory control ratio, due to a lower oxygen consumption during state 4. Bilobalide also decreased the sensitivity of oxygen consumption to inhibition of complex I by Amytal or to inhibition of complex III by antimycin A or myxothiazol. There was no protection of complexes IV and V. It also increased the activity of complex I but not of adenine translocase. Similar effects were also obtained in vitro when control mitochondria were preincubated for 1 hr with 0.8 microg/mL bilobalide. Treatment of the rats with 8 mg/kg bilobalide also prevented the ischemia-induced decrease in state 3 of the mitochondrial respiration and thus the decrease in RCR. The protective effect of bilobalide on cellular ATP content observed under ischemic conditions can be correlated with the above observations. By protecting complex I and III activities, bilobalide allows mitochondria to maintain their respiratory activity under ischemic conditions as long as some oxygen is present, thus delaying the onset of ischemia-induced damage. This mechanism provides a possible explanation for the anti-ischemic properties of bilobalide and of Ginkgo biloba extract in therapeutic interventions.

Protection of hypoxia-induced ATP decrease in endothelial cells by ginkgo biloba extract and bilobalide.

Due to their localization at the interface between blood and tissue, endothelial cells are the first target of any change occurring within the blood, and alterations of their functions can seriously impair organs. During hypoxia, which mimics in vivo ischemia, a cascade of events occurs in the endothelial cells, starting with a decrease in ATP content and leading to their activation and release of inflammatory mediators. EGb 761 and one of its constituents, bilobalide, were shown to inhibit the hypoxia-induced decrease in ATP content in endothelial cells in vitro. Under these conditions, glycolysis was activated, as evidenced by increased glucose transport, as well as increased lactate production. Bilobalide was found to increase glucose transport under normoxic but not hypoxic conditions. In addition, EGb and bilobalide prevented the increase in total lactate production observed after 60 min of hypoxia. However, after 120 min of hypoxia, the total lactate production was similar under normoxic and hypoxic conditions, and both compounds increased this production. These results indicate that glycolysis slowed down between the 60th and 120th minute of hypoxia, while EGb and bilobalide delayed the onset of glycolysis activation. In another experimental model, both compounds were shown to increase the respiratory control ratio of mitochondria isolated from liver of rats treated orally. Since ischemia is known to uncouple mitochondria, the protection of ATP content and the delay in glycolysis activation observed during hypoxia in the presence of EGb 761 or bilobalide is best explained by a protection of mitochondrial respiratory activity, at least during the first 60 min of hypoxia incubation. Both products retain the ability to form ATP, thereby reducing the cell's need to induce glycolysis, probably by preserving ATP regeneration by mitochondria as long as oxygen is available.

Rapid identification of bacteria of the Comamonadaceae with amplified ribosomal DNA-restriction analysis (ARDRA).

Ribosomal rRNA gene fragments (rDNA) encompassing the 16S rDNA, the 16S-23S rDNA spacer region and part of the 23S rDNA of 95 strains belonging to 13 well-described taxa of the eubacterial family Comamonadaceae (beta subclass of the Proteobacteria or rRNA superfamily III) were enzymatically amplified using conserved primers. The fragments of approximately 2400 base pairs were subjected to restriction analysis. Restriction fragment length patterns obtained with HinfI enabled us to distinguish 9 of the 13 taxa studied. Restriction with CfoI was necessary to differentiate Acidovorax delafieldii from A. temperans and Hydrogenophaga flava from H. pseudoflava. The results indicate that amplified rDNA restriction analysis is a simple and reliable tool for the identification of bacterial species.

Effect of aescine on hypoxia-induced activation of human endothelial cells.

Phlebotonic drugs are very often old drugs which improve symptoms in chronic venous insufficiency but their precise mechanism remains unclear. One reason for this lack of information is our poor understanding of the aetiology of the varicose vein. One hypothesis which is being more and more substantiated is that the origin of the disease lies in the activation of the endothelium during blood stasis, leading to a cascade of reactions which, in the long term, alter the structure of the vein wall. In this work, we tested aescine (Reparil i.v. form), a phlebotonic drug, in an in vitro model which mimics this situation, i.e. human endothelial cells exposed to hypoxic conditions. Aescine was shown to inhibit 2 important steps of the activation of endothelial cells incubated 120 min under hypoxia the decrease in ATP content, which is the starting point of the activation cascade, and the increase in the activity of phospholipase A2, an enzyme responsible for the release of precursors of inflammatory mediators. Hypoxia-activated endothelial cells also increase their adhesiveness for neutrophils. This process could also be prevented in a dose-dependent manner if endothelial cells were incubated in the presence of aescine. This inhibition was confirmed by morphological observations in scanning electron microscopy. All 3 effects were already evidenced at 100 ng/ml and were maximal at 750 ng/ml. These effects obtained at very low concentrations probably represent one of the main molecular and cellular mechanisms that underlie, among others, protection of the vessel wall. Objective criteria for our understanding of the preventive action of this phlebotonic drug are, thus, provided.

Protection by bilobalide of the ischaemia-induced alterations of the mitochondrial respiratory activity.

Ischaemia is a common feature of most vascular diseases. There is evidence from experimental and clinical studies that Ginkgo biloba extract protects tissues from ischaemia/reperfusion damages. Bilobalide seems to be responsible, at least in part, for this activity. However, the mechanism of the protection afforded by bilobalide is not yet known. In this work, the effects of bilobalide on mitochondrial respiration were investigated during liver and brain ischaemia, since mitochondria alteration is an early event in ischaemia-induced damage. Bilobalide could prevent the decrease in respiratory activity induced by ischaemia in liver and in brain, both when glutamate/malate or succinate was used as substrate. Ischaemia decreased state 3 respiration rate and bilobalide prevented this decrease. While bilobalide was not able to prevent the decrease in adenine translocase activity, it protected complex I activity. Bilobalide allows mitochondria to maintain their respiratory activity in ischaemic conditions by protecting complex I and probably complex III activities. Hence, the energetic pool of tissues is preserved during the ischaemic period as well as its viability. This mechanism provides, a possible explanation for the anti-ischaemic properties of bilobalide and of Ginkgo biloba extract in therapeutic interventions.

The catabolism of 3-ketolactose in Agrobacterium.

The existence of a novel enzyme, catalyzing the hydrolysis of 3-ketolactose, is described in the different genetic groups of the genus Agrobacterium. The enzyme differs from the other glycosidases formed by Agrobacterium during growth on lactose. The inducibility of the enzyme could be demonstrated in a strain from biotype 1, but not in a strain from biotype 2. The specific activity of the 3-ketolactose hydrolase is higher in extracts of strains belonging to biotype 2 than to biotype 1. The optimum pH of the enzyme in Tris-HCl buffer is 8.4-8.5. The K(m) value for 3-ketolactose is 2.2 × 10(-2) M. The 3-ketolactose hydrolase is stimulated by Mg(2+) and Mn(2+), and inhibited by Zn(2+). Mercaptoethanol promotes the reaction rate in extracts of strains of biotype 1 but not in extracts of strains of bio-type 2.

Differences between subcultures of the Mesorhizobium loti type strain from different culture collections.

Because of differences in the reported 16S rRNA gene sequence of the Mesorhizobium loti type strain available from different culture collections, we collected different subcultures of this strain and compared them by 16S rDNA sequencing, SDS-PAGE of whole-cell protein extracts and RAPD-PCR. Our results indicate that the 16S rDNA sequence differences can be explained by the presence of two different organisms in one of the subcultures. In addition, even for subcultures of the type strain that had identical 16S rDNA sequences, small differences could be observed in the protein profiles and in the RAPD-PCR patterns. These latter observations indicate that maintenance procedures necessary for long-term preservation by freeze-drying can cause subcultures of the same original strain to undergo changes, effectively leading to different fingerprints even though 16S rDNA sequences remain identical.

Treatment of vaginal candidosis with oral ketoconazole.

Results with ketoconazole were studied in 281 non-pregnant patients with acute and chronic Candida-vaginitis. Several dose regimens were evaluated. The 5-day regimens (200 mg b.i.d. or 400 mg once daily) seem to be the most appropriate schedules in this infection. Side effects were minor. Relapse rates are not different from those, historically known, with topical antifungals.

Perfused human saphenous veins for the study of the origin of varicose veins: role of the endothelium and of hypoxia.

If venous stasis due to blood stagnation has been recognized to be involved in the development of varicose veins, the mechanism linking this situation to the modifications of the venous wall observed in varicoses is still unclear. In order to study this mechanism, human saphenous veins were incubated in normoxic or hypoxic conditions and the interactions between the endothelium and neutrophils were investigated. We observed that many neutrophils adhered to the endothelium of veins incubated in hypoxic conditions rather than in normoxia and that these adherent neutrophils were activated: they released high amounts of superoxide anion and of leukotriene B4. Studies in scanning electron microscopy confirmed the increased neutrophil adherence to the endothelium as well as their activation. These results were then related to the histological observation of varicose veins. These veins show a thickening of the media with extracellular matrix deposit as well as an alteration of the elastic lamina with the presence of smooth muscle cells in the intima. These results are in agreement with in vitro studies on isolated endothelial cells. They all show that hypoxia is able to activate endothelial cells: they release inflammatory mediators and become adhesive for neutrophils which are then activated. These activated leukocytes release free radicals and proteases which are able to degrade the extracellular matrix. In addition, hypoxia-activated endothelial cells secrete growth factors which will trigger smooth muscle cell proliferation and the synthesis of extracellular matrix components. Altogether and because they are frequently repeated, these processes could eventually lead to alterations of the venous wall similar to those observed in varicose veins.

Interactions between endothelial cells and smooth muscle cells after their activation by hypoxia. A possible etiology for venous disease.

Because of their localization at the interface between blood and tissue, endothelial cells are responsible for the maintenance of vascular homeostasis. They fulfil a series of various functions and constantly interact with circulating leukocytes and with the smooth muscle cells (SMC) present in the media. Any disturbance of their metabolism can thus lead to alterations of the blood vessel functions. We have shown that hypoxia, for example resulting from venous stasis, induces the activation of endothelial cells which then release inflammatory mediators able to activate neutrophils and to induce their infiltration as well as growth factors for SMC. We propose that these processes are the beginning of a cascade of events eventually leading to structural and functional modifications of the venous wall similar to the ones observed in varicose vein wall. The endothelium alterations resulting from venous stasis would thus be the origin of the development of the venous disease. Pharmacological and clinical evidence reinforce this hypothesis.

Effect of Ruscus extract and hesperidin methylchalcone on hypoxia-induced activation of endothelial cells.

BACKGROUND: Ruscus aculeatus extract and the flavonoid hesperidin methylchalcone (HMC) are drugs used in the treatment of chronic venous insufficiency. METHODS: In the present study, we investigated their effects on the activation of endothelial cells by hypoxia, a condition which mimics venous blood stasis. RESULTS: We observed that Ruscus extract was able to inhibit the activation of endothelial cells by hypoxia: the decrease in ATP content, the activation of phospholipase A2 as well as the subsequent increase in neutrophil adherence with a maximal protection obtained at 50 microg/ml. HMC was also able to inhibit the hypoxia-induced decrease in ATP content. Furthermore, the effects of Ruscus extract and of HMC on this decrease seem to be additive. CONCLUSIONS: The biochemical mechanism evidenced in this work might explain some of the beneficial therapeutic effects of these products in the treatment of chronic venous insufficiency patients.