Interaction between Physical Heterogeneity and Microbial Processes in Subsurface Sediments: A Laboratory-Scale Column Experiment.

Physical heterogeneity determines interstitial fluxes in porous media. Nutrients and organic matter distribution in depth influence physicochemical and microbial processes occurring in subsurface. Columns 50 cm long were filled with sterile silica sand following five different setups combining fine and coarse sands or a mixture of both mimicking potential water treatment barriers. Water was supplied continuously to all columns during 33 days. Hydraulic conductivity, nutrients and organic matter, biofilm biomass, and activity were analyzed in order to study the effect of spatial grain size heterogeneity on physicochemical and microbial processes and their mutual interaction. Coarse sediments showed higher biomass and activity in deeper areas compared to the others; however, they resulted in incomplete denitrification, large proportion of dead bacteria in depth, and low functional diversity. Treatments with fine sediment in the upper 20 cm of the columns showed high phosphorus retention. However, low hydraulic conductivity values reported in these sediments seemed to constraint biofilm activity and biomass. On the other hand, sudden transition from coarse-to-fine grain sizes promoted a hot-spot of organic matter degradation and biomass growth at the interface. Our results reinforce the idea that grain-size disposition in subsurface sandy sediments drives the interstitial fluxes, influencing microbial processes.

Effects of pesticides and pharmaceuticals on biofilms in a highly impacted river.

We investigated the effects of pharmaceuticals and pesticides detected in a Mediterranean river, on fluvial biofilms by translocation experiments performed under controlled conditions. Water was sampled from three sites along a pollution gradient. Biofilms grown in mesocosms containing relatively clean water were translocated to heavily polluted water. Several biofilm descriptors were measured before and after translocations. Fifty-seven pharmaceuticals and sixteen pesticides compounds were detected in river waters. The translocation from less to more polluted site was the most effective. Autotrophic biomass and peptidase increased while phosphatase and photosynthetic efficiency decreased. Multivariate analysis revealed that analgesics and anti-inflammatories significantly affected biofilm responses. Ibuprofen and paracetamol were associated with negative effects on photosynthesis, and with the decrease of the green algae/cyanobacteria ratio, while diclofenac was associated with phosphatase activity. The effects of these emerging compounds on biofilms structure and function may cause important alterations in river ecosystem functioning.

Response of biofilm bacterial communities to antibiotic pollutants in a Mediterranean river.

Antibiotics are emerging contaminants, which wing to their bioactivity, may lead to short-term and long-term alterations of natural microbial communities in aquatic environment. We investigated the effects of antibiotics on biofilm bacterial communities in the Llobregat River (Northeast Spain). Three sampling sites were selected: two less polluted sites and one hotspot. River water was collected from each site and used both as inoculum and medium for growing biofilms in independent mesocosms. After 25d of biofilm colonization, we exposed the colonized biofilms to river waters from the downstream sites (progressively contaminated by antibiotics). A control from each site was maintained where the growing biofilm was always exposed to water from the same site. The bacterial community composition, bacterial live/dead ratio and extracellular enzyme activities of the biofilms were measured before and 9d after exposing the biofilms to increasing contaminated waters. Sixteen antibiotic compounds were detected in the water from the three sampling sites. At each site, the antibiotics present in the highest concentrations were sulfonamides, followed by quinolones and macrolides. Bacterial communities of biofilms grown with the three river waters differed markedly in their structure, but less so in terms of functional descriptors. After switching the medium water to increasing pollution, biofilms exhibited increased levels of actinobacteria (HGC), a trend that was associated to the higher antibiotic concentrations in the water. These biofilms also showed increased bacterial mortality, and decreased extracellular leucine-aminopeptidase and alkaline phosphatase. There was a significant correlation between antibiotic concentrations and biofilm responses. Our results indicate that the continuous entrance of antibiotics in running waters cause significant structural and functional changes in microbial attached communities.

Drought episode modulates the response of river biofilms to triclosan.

The consequences of global change on rivers include altered flow regime, and entrance of compounds that may be toxic to biota. When water is scarce, a reduced dilution capacity may amplify the effects of chemical pollution. Therefore, studying the response of natural communities to compromised water flow and to toxicants is critical for assessing how global change may affect river ecosystems. This work aims to investigate how an episode of drought might influence the response of river biofilms to pulses of triclosan (TCS). The objectives were to assess the separate and combined effects of simulated drought (achieved through drastic flow alteration) and of TCS exposure on biofilms growing in artificial channels. Thus, three-week-old biofilms were studied under four conditions: Control (normal water flow); Simulated Drought (1 week reduced flow+2 days interrupted flow); TCS only (normal water flow plus a 48-h pulse of TCS); and Simulated Drought+TCS. All channels were then left for 2 weeks under steady flow conditions, and their responses and recovery were studied. Several descriptors of biofilms were analyzed before and after each step. Flow reduction and subsequent interruption were found to provoke an increase in extracellular phosphatase activity, bacterial mortality and green algae biomass. The TCS pulses severely affected biofilms: they drastically reduced photosynthetic efficiency, the viability of bacteria and diatoms, and phosphate uptake. Latent consequences evidenced significant combined effects caused by the two stressors. The biofilms exposed only to TCS recovered far better than those subjected to both altered flow and subsequent TCS exposure: the latter suffered more persistent consequences, indicating that simulated drought amplified the toxicity of this compound. This finding has implications for river ecosystems, as it suggests that the toxicity of pollutants to biofilms may be exacerbated following a drought.

A multicenter study of histoplasmosis and blastomycosis after solid organ transplantation.

AIM: A review of the clinical presentation, diagnosis, treatment and outcomes of 30 solid organ transplant recipients (SOTRs) with histoplasmosis or blastomycosis from 3 Midwestern academic medical centers. BACKGROUND: The endemic fungal pathogens, Histoplasma capsulatum and Blastomyces dermatitidis, may cause severe infection in SOTRs. In this report, we describe the clinical presentation, diagnosis, treatment, and outcomes of these endemic fungal infections (EFIs) among SOTRs at 3 academic transplant centers. METHODS: A retrospective review was conducted of SOTRs with histoplasmosis or blastomycosis from 3 Midwestern medical centers in the United States. Data collected included demographics, immunosuppression, clinical presentation, method of diagnosis, antifungal treatment, response to therapy, and patient and graft survival. RESULTS: Between 1996 and 2008, 30 transplant recipients with histoplasmosis or blastomycosis were identified, giving a cumulative incidence of infection of 0.50% (30/5989); 73% of the study patients were renal transplant recipients, and the median time to disease onset after transplantation was 10.5 months. The lungs were the most common site of infection (83%), and 60% had disseminated disease. Urine antigen testing was positive in all patients in whom it was performed (23/23). Initial antifungal therapy consisted of amphotericin B in 70%, and 87% received azoles, typically itraconazole (83%). Two patients developed relapsed infection and 7 patients had graft failure after EFI. Overall mortality was 30%, with an attributable mortality of 13%. CONCLUSIONS: As in several previous single-center studies, the incidence of post-transplant histoplasmosis and blastomycosis was <1%, but often resulted in disseminated infection. In this cohort, EFI was associated with a high rate of allograft loss and overall mortality.

Resistance and recovery of river biofilms receiving short pulses of Triclosan and Diuron.

The effects of the herbicide Diuron (DIU) and the bactericide Triclosan (TCS) were assessed on laboratory-grown stream biofilms. Four week-old biofilms were exposed in mesocosms to 48-hours of short pulses of either DIU or TCS. The direct and indirect effects of each toxicant on the biofilms, and the subsequent recovery of the biofilms, were evaluated according to structural and functional biomarkers. These parameters were analyzed immediately before exposure, immediately after exposure, and 9 and 16days post-exposure. DIU caused an increase in diatom mortality (+79%), which persisted until the end of the experiment. TCS also affected diatom mortality (+41%), although the effect did not appear until 1week post-exposure. TCS caused an increase in bacterial mortality (+45%); however, this parameter returned to normal values 1week post-exposure. TCS compromised the cellular integrity of the green alga Spirogyra sp., whereas DIU did not. TCS also strongly inhibited phosphate uptake (-71%), which did not return to normal values until 2weeks post-exposure. DIU directly affected algae, but barely affected the heterotrophs, whereas TCS seriously impaired bacteria (direct effect) as well as autotrophs (indirect effect). However, the biofilms recovered their normal structure and function within only a few days to a few weeks. These findings demonstrate the capacity of biofilms to cope with periodic inputs of toxicants, but also the risks associated to repeated exposure or multi-contamination in aquatic ecosystems.

Progressive disseminated histoplasmosis presenting as cellulitis in a renal transplant recipient.

With the advent of potent immunosuppressive therapies used in solid organ transplantation, patients are more susceptible to a variety of infectious organisms. Infections may result from atypical pathogens and present in an unusual manner. We describe a case of progressive disseminated histoplasmosis presenting as cellulitis in a renal transplant recipient and review this disease.

Chronic stavudine exposure induces hepatic mitochondrial toxicity in adult Erythrocebus patas monkeys.

OBJECTIVES: To understand the mitochondrial mechanisms underlying the lactic acidosis and hepatic steatosis seen in some HIV-1-infected individuals after long-term stavudine (d4T) exposure, we have explored mitochondrial integrity in adult monkeys (Erythrocebus patas) given a daily human equivalent dose of d4T for 78 days. STUDY DESIGN/METHODS: Three Erythrocebus patas (patas) monkeys were given 3 mg d4T orally twice daily (total 6 mg d4T), or approximately 1.2 mg d4T/kg body weight per day, for 78 days and compared with 3 unexposed animals. Blood taken from controls and from treated monkeys before and after drug exposure was subjected to a complete clinical chemistry profile. Liver and skeletal muscles were examined for oxidative phosphorylation enzyme specific activities, mitochondrial deoxyribonucleic acid (mtDNA) quantity by slot blot, and mtDNA integrity by Southern blot. RESULTS: Clinical chemistry assays demonstrated few significant differences; however, one d4T-exposed monkey had a serum lactate of 8.1 mmol/L after 78 days of oral d4T ingestion. Specific activities of oxidative phosphorylation Complexes I, II, and IV were significantly altered in both livers and skeletal muscles from the d4T-exposed animals, compared with the controls (p < or = 0.05). Significant depletion of mitochondrial DNA was observed in livers of drug-exposed monkeys, but not in skeletal muscle (p < or = 0.05). Further examination of liver DNA by Southern blot confirmed hepatic mtDNA depletion in drug exposed animals. CONCLUSIONS: The data suggest that direct examination of the liver may be required to elucidate clinical d4T-induced hepatotoxicity related to mitochondrial damage.

Incorporation of zidovudine into leukocyte DNA from HIV-1-positive adults and pregnant women, and cord blood from infants exposed in utero.

OBJECTIVE: The nucleoside analog 3'-azido-3'-deoxythymidine (ZDV) has widespread clinical use but also is carcinogenic in newborn mice exposed to the drug in utero and becomes incorporated into newborn mouse DNA. This pilot study was designed to determine ZDV incorporation into human blood cell DNA from adults and newborn infants. DESIGN: In this prospective cohort study, peripheral blood mononuclear cells (PBMC) were obtained from 28 non-pregnant adults and 12 pregnant women given ZDV therapy, six non-pregnant adults with no exposure to ZDV, and six non-pregnant adults who last received ZDV > or = 6 months previously. In addition, cord blood leukocytes were obtained from 22 infants of HIV-1-positive, ZDV-exposed women and from 12 infants unexposed to ZDV. There were 11 mother-infant pairs involving HIV-1 -positive women. METHODS: DNA was extracted from PBMC obtained from non-pregnant HIV-1-positive adults taking ZDV, pregnant HIV-1-positive women given ZDV during pregnancy, and from adults not taking ZDV. Cord blood leukocytes were examined from infants exposed to ZDV in utero and from unexposed controls. DNA samples were assayed for ZDV incorporation by anti-ZDV radioimmunoassay (RIA). RESULTS: The majority (76%) of samples from ZDV-exposed individuals, pregnant women (8 of 12), non-pregnant adults (24 of 28), or infants at delivery (15 of 22), had detectable ZDV-DNA levels. The range of positive values for ZDV-treated adults and infants was 25-544 and 22-452 molecules ZDV/10(6) nucleotides, respectively. Analysis of 11 mother-infant pairs showed variable ZDV-DNA incorporation in both, with no correlation by pair or by duration of drug treatment during pregnancy. Two of the 24 samples from individuals designated as controls were positive by anti-ZDV RIA. The 20-fold range for ZDV-DNA values in both adults and infants suggested large interindividual differences in ZDV phosphorylation. CONCLUSIONS: Incorporation of ZDV into DNA was detected in most of the samples from ZDV-exposed adults and infants. Therefore, the biologic significance of ZDV-DNA damage and potential subsequent events, such as mutagenicity, should be

[Authors' experience with transvaginal administration of progestagens]. / Nostra esperienza sulla somministrazione dei progestinici per via transvaginale.

The authors, after a short introducing on the most used kinds of progestins in Hormonal Replacement Therapy (HRT), report this own clinical experience on the efficacy of a micronized progestin treatment given by the vaginal route in comparison with oral somministration, studying in details the protective effects on endometrial hyperplasia and cancer. The role of danazolo on the hormonal balance during HRT has been also evaluated. The results suggest a positive effects of the vaginal somministration of micronized HRT progesterone or danazolo.

[A case of difficult diagnosis of primary tubal carcinoma]. / Un caso di difficile diagnosi di carcinoma tubarico primitivo.

Primary Fallopian tube cancer is a very un common cancer that appears between 40 and 65 years old, highly aggressive associate to a poor survival. In this work the authors explain a clinic case of primary Fallopian tube cancer in a woman of 57 years old operated for endometrial cancer. The authors display that the definitive diagnosis was possible only after the histological examination of the operating piece.

[Review on renal calculosis in pregnancy]. / Review sulla calcolosi renale in gravidanza.

By the analysis of the series reported by many authors, urolithiasis in pregnancy seems to be a rare, but significant pathology. The disease, potentially dramatic for the mother and fetus, appearing into a such particular physiological state like is pregnancy, suggests a reevaluation of diagnostic and therapeutic methods and better control of maternal and fetal risk. Furthermore, urolithiasis must be considered as cause of premature birth, a very severe complication of pregnancy the incidence and predisposing factors of urinary tract stones are generally the same in nonpregnant women. But any metabolic effects and the anatomical changes happen in pregnancy can have a important role on stone's formation. Signs and symptoms in urinary stone disease are: colic, flank pain, hematuria, urinary tract infection; irritative voiding, fever. The initial evaluation and treatment are again similar to those used for the non pregnant population. Radiographic studies any way must be used with caution for the risks of the ionizing radiations for the fetus. All forms of treatment with the exception of extracorporeal shock ware lithotripsy, are appropriate in the pregnant patients but naturally very useful, for the appropriate care of these patients is the coordination by the urologist, the obstetrician, the pediatrician, the radiologist and the anesthesiologist.