Association of pregnancy and Candida vaginal colonization in women with or without symptoms of vulvovaginitis.

AIM: Candida infection is one of the main causes of vulvovaginitis. The experience of symptoms of vulvovaginitis during pregnancy changes in relation to clinical, behavioral, and demographic factors. Candidiasis is associated with an increased risk of delivery complications. In some studies pregnant women are found more symptomatic than non-pregnant women, but in others a higher prevalence of asymptomatic infections is described during pregnancy. The aims of this study were to evaluate the prevalence of Candida vaginal colonization in pregnant women, and investigate if the occurrence of symptoms is influenced by pregnancy, in a population of Italian native and immigrant women. METHODS: A total of 344 outpatients, who visited the laboratory for routine genital examination, independently of pregnancy or presence or absence of symptoms of vulvovaginitis, were evaluated. RESULTS: Colonization by Candida spp. was significantly higher in pregnant than non-pregnant patients (31.4% vs. 19.9%; χ2=5.59; P=0.018), nevertheless pregnant women were significantly more often asymptomatic compared to non-pregnant (46.5% vs. 16%; χ2=42.31; P<0.0001). In the sub-group of women colonized by Candida spp., pregnancy resulted significantly associated to asymptomatic infection (58.1% vs. 30.8%; χ2 =6.18; P=0.013). A binary logistic regression analysis showed pregnancy or lactobacilli colonization independently associated to a lower probability of experiencing symptoms of vulvovaginitis (respectively: P<0.0001 and P=0.008). CONCLUSION: Pregnancy seems to be independently associated to Candida spp. asymptomatic vaginal infection. Given that candidiasis has been associated with possible delivery complications, these results suggest to screen for Candida spp. vaginal colonization asymptomatic women during pregnancy.

In vitro activity of zidovudine alone and in combination with ciprofloxacin against Salmonella and Escherichia coli.

The in vitro antibacterial activity of zidovudine alone and in combination with ciprofloxacin was investigated. Zidovudine showed a good activity against Escherichia coli and Salmonella (MIC range 0.5-8 micrograms/ml and 1.5-62 micrograms/ml respectively) isolated from biological samples of HIV-infected patients. These strains proved to be extremely susceptible to ciprofloxacin alone. The interaction between zidovudine and ciprofloxacin ranged from additive activity to indifference. No antagonism was observed: the FIC index for every combination resulted < or = 1.5. The addition of AZT 1 mg/l (clinically achievable plasma concentration after therapeutic doses of 1200 mg/day) did not affect the bactericidal activity of ciprofloxacin; on the contrary, in some cases we observed an increase of bactericidal effect of the quinolone. These data have to be considered in patients with AIDS who can be treated concomitantly with zidovudine and ciprofloxacin.

Helicobacter pylori infection and cytotoxic antigen associated gene "A" status in short children.

BACKGROUND: Helicobacter pylori is now an accepted gastroduodenal pathogen and is being investigated for possible implications in nongastroenterological conditions such as growth impairment. Subjects infected by cytotoxic Cag-A positive strains seem more likely to develop serious gastroduodenal diseases but the possible role of Cag-A positive strains in non gastroenterological diseases has not been fully investigated. OBJECTIVE: 1) To evaluate the prevalence of Helicobacter pylori infection and Cag-A positivity in short children compared to auxologically normal children. All the subjects were without gastro-intestinal symptoms and were not obese or significantly underweight. 2) To verify the reliability of the ELISA assay for H. pylori. SUBJECTS: H. pylori infection was assessed in 338 children, 182 auxologically normal and 156 short children, with and without deficiency in growth hormone, by the determination of specific IgG antibody. In 79 subjects (all seropositive and a random sample of seronegative children), 13C-urea breath test and cytotoxic Cag-A positive strains were examined. RESULTS: The overall seroprevalence of H. pylori infection by IgG antibody was 18/156 (11.5%) and 13/182 (7.1%) in short and auxologically normal children respectively. The 13C-urea breath test was positive in 29 children: 17 (10.9%) short and 12 (6.6%) auxologically normal. Western blotting documented infection by cytotoxic Cag-A positive strains in 12/17 (70.6%) and 8/12 (66.6%) of short and auxologically normal children respectively. None of the differences between the two groups were significant. CONCLUSIONS: 1) We found a similar prevalence of H. pylori infection and Cag-A positivity in two large pediatric populations of short or auxologically normal children. Therefore: 1) Our data did not confirm a role of H. pylori infection in short stature in children. 2) We found a high reliability of ELISA assay for the detection of IgG antibodies compared to breath test.

Antimicrobial activity of fluoroquinolones and other antibiotics on 1,116 clinical gram-positive and gram-negative isolates.

A total of 1,116 clinically isolated strains belonging to Staphylococcus aureus (200), Staphylococcus epidermidis (200), Streptococcus pneumoniae (20), Escherchia coli (200), Klebsiella spp. (177), Serratia marcescens (22), Pseudomonas aeruginosa (224), Haemophilus influenzae (35) and Salmonella (38) from the Department of Infectious Diseases, La Sapienza University in Rome (Italy) were tested against three fluoroquinolones (ofloxacin, ciprofloxacin and levofloxacin) and 10 other antibiotics (augmentin, ampicillin, cefaclor, cefixime, cefotaxime, cotrimoxazole, gentamicin, minocycline, oxacillin and vancomycin). Fluoroquinolones inhibited essentially about 100% of H. influenzae, Salmonella and S. pneumoniae, more than 75% of Staphylococcus including methicillin-resistant strains, and about 90% of Enterobacteriaceae and 50% of P. aeruginosa. Minimal inhibitory concentration values ranged from < 0.015 to > 32 micrograms/ml for Klebsiella, S. aureus and epidermidis, E. coli and P. aeruginosa; from < 0.015 to 2 micrograms/ml for Salmonella; from 0.03 to 16 micrograms/ml for Serratia; from < 0.015 to 1 microgram/ml for Haemophilus; and from 0.5 to 2 micrograms/ml for S. pneumoniae. Levofloxacin and to a lesser extent ofloxacin and ciprofloxacin, generally exhibited a greater activity than the other agents against both Gram-positive and Gram-negative bacteria. Regarding the distribution of resistant strains in Italy, we found a peculiar pattern of resistance as far as E. coli and P. aeruginosa were concerned. Quality control parameters are also summarized. S. epidermidis resulted as a new emergent pathogen especially in immunocompromised patients and its level of sensitivity has been modified over the last few years. In fact, the percentage of resistant strains to antibiotics or the percentage of methicillin-resistant isolates (in our study 35%), has gradually increased. Levofloxacin and ofloxacin showed good activity against staphylococcal strains compared with the majority of other antibiotics. These results suggest that the newer quinolones are promising antimicrobial agents for various infections.

Plasmids as epidemiologic markers in nosocomial gram-negative bacilli: experience in an intensive care unit.

The authors have compared the antimicrobial resistance patterns and plasmid profiles of Gram-negative isolates in an intensive care unit over a 7-month period in order to identify epidemiologically related isolates. Bacterial plasmids were found to be valuable markers for the comparison of strains of nosocomial Gram-negative bacilli. Thirty-nine mechanically ventilated patients in an ICU were included. From bronchoaspiratus, the authors isolated 58 strains of Gram-negative bacilli (24 Ps. aeruginosa and 34 Enterobacteria). Common plasmids were found in most Enterobacteria. The interspecies plasmid exchange suggests that interstate spread of these strains may have occurred. Twenty-six Enterobacteria carried plasmids, 11 of which proved transmissible. The R-factors were transferred to other genera that were isolated in the hospital, thereby adding to the pool of multiresistant nosocomial isolates. Larger plasmids transferred ampicillin and carbenicillin resistance, while gentamycin and cephalotin resistance was carried by smaller plasmids. Only 4 Ps. aeruginosa carried plasmids, one of which was transmissible. Pseudomonas plasmid DNA is extracted with difficulty by the simple lysis method, due to the roughness of the colonies. All Pseudomonas isolates belonged to the same biotype which can be regarded as an epidemiological marker. Therefore, plasmid profiling is a useful tool for epidemiological surveillance of Enterobacteria and is a good method for determining the relatedness of isolates in a nosocomial environment.

The influence of the SOS response on the activity of 4-quinolones and zidovudine against some strains of Enterobacteria.

The 4-Quinolones are known to induce the SOS response. This should also be the case with AZT (Zidovudine) which has the same bactericidal mechanism. SOS response might make the bacteria more sensitive or more resistant to subsequent doses of quinolones and AZT. NA (Nalidixic acid), the first quinolone of the early 1960s, sensitises a strain of E. coli isolated from the urine of patients with cystopyelitis and the E. coli AB1157 wild type strain which is a well-known SOS inducer. In this case, the SOS system is not involved but only the recombination repair mechanisms which make the bacteria more susceptible to further damage by NA. On the contrary, CPX (Ciprofloxacin) protects E. coli from further exposure to antibiotics. Therefore the SOS response induction assists the bacteria in recovering from the DNA damage caused by CPX. The SOS response induced by AZT in the tested E. coli strains does not seem to either contribute to the lethality of the drug or to be involved in protecting bacteria from the damage caused by AZT. In fact, the percentage of killing was the same for both pre-treated and non pre-treated bacteria (p = 0.5). On the contrary, it was found that in Salmonella typhimurium belonging to blood of a patient with recurrent bacteriaemia, the CPX added to pre-treated bacteria with AZT was less lethal than when it was added to non pre-treated bacteria. The SOS response, in this case, protects bacteria from the damage caused by AZT.

[Critical considerations on various experimental staphylococcus infections]. / Considerazioni critiche su alcune infezioni sperimentali da stafilococco.

The authors discuss some problems concerning the use of models in biomedical research and particular animal models of staphylococcal infections simple, reproducible and similar to the corresponding human diseases. Two models of staphylococcal infections are examined in particular: experimental endocarditis and osteomyelitis, considering their characteristics and reliability in relation to the corresponding human diseases.

[The effect of orthodontic magnets on the oral microbial flora]. / Influenza dei magneti ortodontici sulla flora microbica orale.

In this study we wanted to test the in vitro effects of orthodontic magnetic brackets, developing different magnetic fields, on the oral microbial flora. We noticed that a magnetic field has its most considerable influence on Candida albicans growth; the stimulating response depends on various factors: cell inoculum, exposure time and magnetic field frequency.

[Eosinophilia-myalgia syndrome associated with 5-OH-tryptophan. Description of a case]. / Sindrome eosinofilia-mialgia associata a 5-OH-triptofano. Descrizione di un caso.

The Authors report a case of eosinophilia-myalgia syndrome in a patient with a history of alcohol abuse, treated with a 5-OH-tryptophan containing drug. As regards the pathogenesis of this "new" clinical syndrome, three major hypotheses can be considered: a) autoimmune, according to which tryptophan could act as an "immunogenic" stimulus, thus evoking a cell-mediated reaction against neuromuscular structures; b) dysmetabolic, that is to say, related to neurotoxic metabolites of tryptophan, which in certain conditions could be degraded by an "alternate" pathway that is normally less operating; c) toxic, which is the most accredited nowadays, according to which there is a toxic factor, perhaps similar to aniline, linked to the process of manufacture and purification of L-tryptophan. In our patient, the drug withdrawal and a therapy with steroids led to the remission of the syndrome.

Cell cycle blockers mimosine, ciclopirox, and deferoxamine prevent the death of PC12 cells and postmitotic sympathetic neurons after removal of trophic support.

In the present study, we tested whether apoptotic neuronal death caused by withdrawal of trophic support might be prevented by agents that block cell cycle progression. We used three complementary model systems that exhibit apoptotic death: dividing PC12 cells deprived of nerve growth factor (NGF); and primary cultures of postmitotic sympathetic neurons deprived of NGF. We show that cell death in each case can be suppressed by treatment with the G1/S blockers mimosine, ciclopirox, and deferoxamine at concentrations that correlate with their abilities to block PC12 cell proliferation. In contrast, agents that block cell cycle progression in the S-, G2-, or M-phase do not prevent cell death. These observations support the hypothesis that removal of trophic support from dividing or postmitotic neuronal cells provokes their apoptotic death by causing them either to proceed through or to attempt to re-enter an uncoordinated and consequently fatal cell cycle. Moreover, the data suggest that simply blocking the cycle at any point is not protective but, rather, that it is necessary to block at specific "safe" points. This study defines a safe point in the cell cycle before the G1/S transition that is demarcated by the action of these three agents.

Glutamate metabolism in rat cortical astrocyte cultures.

Glutamate metabolism in rat cortical astrocyte cultures was studied to evaluate the relative rates of flux of glutamate carbon through oxidative pathways and through glutamine synthetase (GS). Rates of 14CO2 production from [1-14C]glutamate were determined, as was the metabolic fate of [14C(U)]glutamate in the presence and absence of the transaminase inhibitor aminooxyacetic acid and of methionine sulfoximine, an irreversible inhibitor of GS. The effects of subculturing and dibutyryl cyclic AMP treatment of astrocytes on these parameters were also examined. The vast majority of exogenously added glutamate was converted to glutamine and exported into the extracellular medium. Inhibition of GS led to a sustained and greatly elevated intracellular glutamate level, thereby demonstrating the predominance of this pathway in the astrocytic metabolism of glutamate. Nevertheless, there was some glutamate oxidation in the astrocyte culture, as evidenced by aspartate production and labeling of intracellular aspartate pools. Inhibition of aspartate aminotransferase caused a greater than 70% decrease in 14CO2 production from [1-14C]glutamate. Inhibition of GS caused an increase in aspartate production. It is concluded that transamination of glutamate rather than oxidative deamination catalyzed by glutamate dehydrogenase is the first step in the entry of glutamate carbon into the citric acid cycle in cultured astrocytes. This scheme of glutamate metabolism was not qualitatively altered by subculturing or by treatment of the cultures with dibutyryl cyclic AMP.

Inhibitors of cyclin-dependent kinases promote survival of post-mitotic neuronally differentiated PC12 cells and sympathetic neurons.

Previous studies have demonstrated that multiple agents that promote survival of PC12 cells and sympathetic neurons deprived of trophic support also block cell cycle progression. Presently, we address whether inhibition of cell cycle-related cyclin-dependent kinases (CDKs) prevents neuronal cell death. We show that two distinct CDK inhibitors, flavopiridol and olomoucine, suppress the death of neuronal PC12 cells and sympathetic neurons. In addition, we demonstrate that inhibitor concentrations required to promote survival correlate with their ability to inhibit proliferation. Promotion of survival, however, does not correlate with inhibition of extracellular signal-regulated kinase or c-Jun kinase activities or with interference with the activation of c-Jun kinase that accompanies serum/nerve growth factor deprivation. In contrast to their actions on nerve growth factor-differentiated PC12 cells, the CDK inhibitors do not prevent the death of proliferation-competent PC12 cells and, in fact, promote their cell death. These findings support the hypothesis that post-mitotic neuronal cells die after removal of trophic support due to an attempt to re-enter the cell cycle in an uncoordinated and inappropriate manner. We speculate that cycling PC12 cells are not saved by these agents due to a signaling conflict between an inherent oncogenic signal and the inhibition of CDK activity.

Nitric oxide delays the death of trophic factor-deprived PC12 cells and sympathetic neurons by a cGMP-mediated mechanism.

We have used cultured PC12 cells and rat sympathetic neurons as model systems to examine the regulation of neuronal cell death and survival. Because nitric oxide (NO) may be involved in nerve growth factor (NGF) signaling in PC12 cells, we tested NO-generating compounds for their ability to protect PC12 cells and sympathetic neurons from death after withdrawal of trophic support. Three such agents, S-nitroso-N-acetylpenicillamine (SNAP), diethylenetriamine NO adduct (DETA-NO), and sodium nitroprusside provide (SNP), were found to promote complete short-term survival after removal of serum from naive PC12 cells and of NGF from neuronally differentiated PC12 cells and sympathetic neurons. One major target of NO action is guanylate cyclase, which is activated by nitrosylation of its heme prosthetic group. We observed that inhibition of guanylate cyclase blocks the protective effects of the NO generators on trophic factor-deprived PC12 cells and sympathetic neurons without preventing NGF-induced survival. We also found that permeant cGMP analogs and an inhibitor of cGMP-specific phosphodiesterase enhance cell survival, suggesting that the protective effects of NO are mediated by activation of guanylate cyclase and increased intracellular cGMP. N-Nitro-L-arginine methyl ester, a NO synthase inhibitor, did not block NGF-promoted PC12 cell or sympathetic neuron survival. These findings indicate that like NGF, NO has survival-promoting actions on neurons but that the two agents work by initially independent mechanisms.

Neuroprotective actions of dipyridamole on cultured CNS neurons.

We report that dipyridamole is neuroprotective for a variety of rat embryonic CNS neurons cultured in serum-free basal medium lacking trophic factors or other additives. We also describe the mechanism underlying this action. Neurons died rapidly in basal medium but were rescued in large measure by 10 microM dipyridamole. The protective action of dipyridamole seems to be attributable to its antioxidant property. Vitamin E and N-acetylcysteine provided comparable neuroprotection in basal medium, whereas an array of compounds that mimic other actions of dipyridamole (inhibition of phosphodiesterases, blockade of nucleoside and chloride transport, interference with the multidrug resistance protein, and enhancement of prostacyclin synthesis) failed to promote survival. Thus, a major cause of neuronal death in this system seems to be oxidative stress that is relieved by dipyridamole. Iron plays a significant role in generation of such stress, as indicated by the observations that addition of apotransferrin or iron chelators to basal medium or use of iron-free medium also afforded protection. Although oxidative stress was a major determinant of neuronal death, it was not the only factor. Dipyridamole or other antioxidant measures did not provide sustained neuroprotection. However, provision of insulin, which was not protective alone in basal medium, along with dipyridamole significantly enhanced long-term neuronal survival. Hence, optimal protection requires both trophic support and relief from oxidative stress. These findings lend credence to the potential use of dipyridamole or its derivatives in prevention and/or treatment of CNS injuries and degenerative disorders in which oxidative stress is a significant component.

Augmentation of GG2EE macrophage cell line-mediated anti-Candida activity by gamma interferon, tumor necrosis factor, and interleukin-1.

The expression of anti-Candida activity in the GG2EE macrophage cell line, generated by immortalization of fresh bone marrow with v-raf and v-myc oncogenes, was studied. GG2EE cells spontaneously inhibited the growth of an agerminative mutant of Candida albicans in vitro. The anti-Candida activity was maximal after 8 h of coculture and was proportional to the effector-to-target ratio. Gamma interferon (IFN-gamma), interleukin-1 (IL-1), and tumor necrosis factor (TNF) all significantly enhanced the anti-Candida activity of GG2EE cells. In contrast, IL-3, IL-4, and colony-stimulating factor 1 were ineffective. The augmentation of anti-Candida activity was not always concomitant with enhancement of phagocytosis, since IFN-gamma and colony-stimulating factor 1, but not IL-1 or TNF, augmented the phagocytic ability of GG2EE cells. Furthermore, the augmentation of anti-Candida activity in GG2EE cells did not correlate with the acquisition of antitumor activity. In fact, none of the cytokines alone were able to induce antitumor activity in GG2EE cells, which, however, could be activated to a tumoricidal stage by IFN-gamma plus heat-killed Listeria monocytogenes. These findings demonstrate that GG2EE cells exhibit spontaneous anti-Candida activity and that such activity is enhanced by TNF, IL-1, and IFN-gamma.

Ordering the cell death pathway. Differential effects of BCL2, an interleukin-1-converting enzyme family protease inhibitor, and other survival agents on JNK activation in serum/nerve growth factor-deprived PC12 cells.

Previous studies indicate that activation of c-Jun kinase (JNK) is necessary for apoptosis of trophic factor-deprived PC12 cells and that death in this system is suppressed by multiple agents, including BCL2, inhibitors of the interleukin-1-converting enzyme (ICE) family of proteases, blockers of transcription, and a variety of small molecules with differing modes of action. Here, we determine the order in which these agents block apoptosis relative to JNK activation. Overexpression of BCL2 promotes PC12 cell survival and blocks JNK activation caused by trophic factor withdrawal. Similarly, the survival-promoting agents aurintricarboxylic acid, N-acetylcysteine, the nitric oxide generator diethylenetriamine nitric oxide, 8-bromo-cGMP, and 8-(4-chlorophenylthio)-cAMP act upstream to inhibit JNK activation. In contrast, zVAD-fluoromethylketone (a permeant ICE family inhibitor), actinomycin D, and the G1/S cell cycle inhibitor deferoxamine, all promote survival after trophic factor withdrawal, but do not affect JNK activation. These findings are consistent with the presence of an ordered cell death pathway triggered by trophic factor deprivation in which 1) BCL2 and a number of survival-promoting agents act upstream of JNK, 2) ICE family protease actions, regulated genes required for cell death, and certain cell cycle blockers lie either downstream of JNK or on independent pathways required for apoptotic death.

[Response to vaccination against the etiologic agent of viral hepatitis B (HBV) in a population at risk]. / Risposta alla vaccinazione contro l'agente eziologico dell'epatite virale B (HBV) in una popolazione a rischio.

We report the results of the vaccinations against hepatitis B carried out with vaccine H-B-VAX of the commercial firm (Merck Sharp and Dohme), on 102 U.S.L. 32 hospital workers in Portomaggiore (Ferrara, Italy). The vaccine rendered 92% of the subjects inoculated immune and the incidence of secondary effects was low.

Immunomodulation by Candida albicans: crucial role of organ colonization and chronic infection with an attenuated agerminative strain of C. albicans for establishment of anti-infectious protection.

Intravenous inoculation of an attenuated agerminative strain of Candida albicans (PCA-2) of low virulence, but not of two other species of Candida of low virulence (C. parapsilosis and C. viswanathii) into CD2F1 mice conferred protection against the highly virulent microbes C. albicans CA-6, Staphylococcus aureus and Aspergillus fumigatus. To provide protection, a definite inoculum size (10(6) cells per mouse) resulting in organ colonization and establishment of a long-lasting chronic infection with PCA-2 was needed. An inoculum of 10(5) cells gave rise to transient kidney colonization whereas inocula greater than 10(6) cells led to acute septicaemia and eventual death. Chronic infection of mice following inoculation of 10(6) PCA-2 cells was accompanied by detectable mannoprotein antigen levels in the serum (30-70 ng ml-1) while specific antibodies did not appear until 14 d after inoculation, at which time low antimannan antibody was present (ELISA titre 1:40-1:80). Chronic infection was characterized by the presence in the kidneys of 2-3 x 10(6) c.f.u. of PCA-2 for at least 40 d after inoculation. Pharmacological modulation of the host through administration of either an anti-Candida drug, amphotericin B, or an immunosuppressive agent, cyclophosphamide, strongly supported the premise that the anti-infectious state conferred by PCA-2 'immunization' correlated with the maintenance of a sufficient number of PCA-2 in vivo. Protection was 'switched on' when 2-3 x 10(5) cells were present in the kidneys. It was maximal at a kidney count of 2-3 x 10(6) c.f.u. of PCA-2, and promptly declined when the number of PCA-2 cells in the kidney fell below 2 x 10(5). Mice chronically infected with PCA-2 had splenic macrophages with pronounced candidacidal activity in vitro. Modulation of the growth of PCA-2 in vivo, which determined activation or deactivation of the protective state, was paralleled by a similar modulation in macrophage activation, showing that in all cases resistance to virulent organisms persisted as long as macrophage activation was present. The results demonstrate that a critical in vivo antigenic load is crucial for the occurrence of resistance to infection and suggests that macrophages could be involved in this protection.

Calcium ionophore A-23187 inhibits the secretion of beta-hexosaminidase from the GG2EE mouse macrophage cell line.

Secretion of the lysosomal enzyme beta-N-acetylhexosaminidase is inhibited by calcium ionophore A-23187 in the GG2EE macrophage cell line. Such inhibition is time and dose dependent. Calcium ionophore A-23187 treatment causes a change in the pattern of hexosaminidase isoenzymes detectable in the cell extract, as assessed by DEAE-cellulose chromatography. In particular, control cells show two hexosaminidase isoenzymes corresponding to hexosaminidase A and B, whereas cells treated with calcium ionophore A-23187 express a third isoenzyme form with properties similar to hexosaminidase S.