The Formation of Otoliths in the Frog Rana esculenta. Scanning Electron Microscopic and X-Ray Diffraction Studies

Two crystal forms of calcium carbonate were observed: calcite (utricle) and aragonite (saccule, lagena, endolymphatic sac). The first step in otolith formation is the appearance of organic structures in the macula. The subsequent step is characterized by fast growing primitive crystals with a prismatic habitus that successively transform into adult or mature crystals. With the metamorphosis, the aragonite crystals of the endolymphatic organ show clear signs of erosion that can be related to a process of CaCO₃ mobilization from such deposits.     

Inhibition of Virulence Factors of <Emphasis Type="Italic">Candida</Emphasis> spp. by Different Surfactants

Candida yeasts are opportunistic pathogens responsible for infections in immunocompromised individuals. Among the virulence factors present in these yeasts we can mention the ability to adhere to host cells, exoenzyme production and germ tube formation. Several compounds, such as antifungal agents, plants extracts, protein inhibitors and surfactants, have been tested regarding their capacity in inhibit Candida spp. virulence factors. Among these compounds, a significant lower number of works are focused on the inhibition action caused by different types of surfactant. The present work aimed to evaluate the effect generated by the surfactants cetyltrimethylammonium chloride (CTAC), sodium dodecyl sulfate (SDS), N-hexadecyl-N–N′-dimethyl-3-ammonio-1-propane-sulfonate (HPS) and octylphenoxypolyethoxyethanol (Triton X-100) on the viability, adhesion ability and exoenzyme production by Candida species. CTAC and HPS were capable to inhibit Candida spp. growth at very low concentrations. All surfactants demonstrated to be capable to inhibit the adhesion of Candida species to buccal epithelial cells (BEC) and the proteinase production. On the other hand, the phospholipase production remained unaltered after the treatment with these compounds. The present data denote that cationic and zwitterionic surfactants are interesting prototypes of inhibitory agents against Candida spp., which is probably associated with the cationic punctual charge of both surfactants. The results are discussed in details in agreement with recent reports from literature.     

Scanning Electron Microscopy and X-ray Diffraction Studies of the Macular Crystals in the Chondrostean Fish Erpetoichthys calabaricus (Smith)

Morphologic and crystallographic studies of the otoliths of the reed-fish Erpetoichthys calabaricus showed (1) aragonite statoliths with a serrated surface, and (2) two populations of statoconia: one of numerous discoid biconvex crystals of vaterite, the other of pseudohexagonal crystals of aragonite. We suggest that the presence of two calcium carbonate polymorphs in the statoacoustic organs of this archaic fish may have an evolutionary, as well as a systematic and functional significance.     

Influence of rat prenatal and postnatal exposure to a non-steroidal anti-inflammatory agent (flunoxaprofen) on cardiovascular function in the progeny

The present experiments evaluated in rats the effects of prenatal and postnatal exposure to a non-steroidal antiinflammatory agent, flunoxaprofen (5-10 and 20 mg/kg/day by the oral route), on cardiovascular function in the pups. In both conscious and anaesthetized rats pre- and postnatal flunoxaprofen exposure at the 30th and 60th day of age, significantly (P less than .05) induced a decrease of pressor response to carotid-sinus baroreceptor stimulation and to L-noradrenaline (0.1-1 and 5 micrograms/kg iv), and an increase of the hypotensive responses to L-isoprenaline (0.01-0.1 and 1 microgram/kg iv) and acetylcholine (0.01-0.1 and 1 microgram/kg iv). These effects were not observed in rats on the 90th day of age. Moreover, pre- and postnatal flunoxaprofen exposure did not modify systolic arterial blood pressure of plasma levels of catecholamines and acetylcholinesterases. Our results also show that in normotensive rats flunoxaprofen exposure during pregnancy did not affect the body weight, systolic or diastolic blood pressure or heart rate of pregnant rats. It did not affect the length of gestation, number of pups per litter or pup body weight. No macroscopic teratogenic effects were observed.     

Cancer surveillance in Italian army peacekeeping troops deployed in Bosnia and Kosovo, 1996–2007: Preliminary results

Objective: An excess of cancer cases was reported in 2000 among Italian troops involved in peacekeeping operations in Bosnia and Kosovo. A preliminary assessment of cancer risk in this cohort was done for the period 1996–2007, based on cancer surveillance activity, which was started in 2001. Methods: A retrospective cohort study was done among 27 361 Italian Army soldiers deployed in Bosnia, 31 052 deployed in Kosovo, and a control group of non-deployed soldiers, whose number varies from 130 275 in 1996 to 40 967 in 2007. Standardized incidence ratio and 95% confidence intervals (SIR [95% CI]) of the main types of tumours were computed as the ratio of the observed and expected cases. Results: 98 incident cancers were reported among soldiers deployed in Bosnia, 66 in those stationed in Kosovo and 388 in non-deployed personnel. Overall, cancer incidence was lower than expected in all groups. Annual SIR was significantly higher than expected in 2000 for Hodgkin's lymphoma only among troops deployed in Bosnia (4.34 [1.18–11.12]) and non-deployed personnel (3.48 [1.67–6.39]); and in 2001 for thyroid cancer only among troops deployed in Bosnia (5.28 [1.44–13.51]). Conclusion: Although further investigation is needed, these preliminary results give no indication of an increased risk of cancer for Italian soldiers who were stationed in Bosnia and Kosovo. The cluster of Hodgkin's lymphoma in 2000 and of thyroid cancer in 2001 were sporadic events, they did not specifically affect deployed personnel and are unlikely to be related to environmental exposures in the Balkans.     

Comparative analysis of Cryptosporidium, Giardia and indicator bacteria during sewage sludge hygienization in various composting processes

AIMS: To evaluate the suitability of Clostridium perfringens, Escherichia coli and enterococci as indicator organisms for Cryptosporidium and Giardia in treated sludge. METHODS AND RESULTS: Occurrence of Cryptosporidium oocysts and Giardia cysts, detected and enumerated by direct immunofluorescence microscopy, were compared with counts of indicator bacteria during six different sewage sludge hygienization processes, including closed reactor and open windrow composting, and sludge sanitation by quicklime or peat addition. No statistical correlation existed between the counts of indicator bacteria, Cl. perfringens, E. coli, and enterococci and occurrence of Cryptosporidium or Giardia. In sludge end-products, Giardia cysts were detected more frequently than Cryptosporidium oocysts. SIGNIFICANCE OF THE STUDY: Direct analysis is the best method to confirm the presence of (oo)cysts in sludge.     

Oxidative status in chronic hepatitis C: the influence of antiviral therapy and prognostic value of serum hydroperoxide assay

The effect of alpha-interferon (alpha-IFN) and ribavirin (RBV) treatment on oxidative status in chronic hepatitis C (CHC) is unknown. AIM: To study the time course of oxidative status in patients with CHC during alpha-IFN and RBV administration, and to evaluate the role of oxidative status in order to predict the therapeutic response. PATIENTS AND METHODS: Fifty one patients with CHC were studied. All received a combination of alpha-IFN and RBV for 6 or 12 months in relation to the type of response. The hydroperoxides concentration in serum test samples by D-ROM test was measured in all of the patients before therapy. In 27 patients, hydroperoxides were also measured during the treatment and during the 12 subsequent months. RESULTS: Cross-sectional analysis demonstrates that patients with a successive long-term response had a lower basal serum hydroperoxide concentration than non-responders (280 +/- 40.8 vs 337 +/- 83 CARR Units, p < 0.05). This resulted to be an independent factor predictive of long-term response in the multi-varied analysis. Longitudinal observation on 27 patients showed that the mean hydroperoxide concentration decreased significantly during treatment (T0 329 +/- 79.2 vs T12 272 +/- 34.5 CARR Units) and that the decrease in the mean values was mainly due to variations in the relapsers group. CONCLUSIONS: Normal basal hydroperoxide concentration helps to predict long-term response to combination therapy. The D-ROM test may be used for screening patients before treatment.     

Synergic Effect of Photodynamic Therapy with Methylene Blue and Surfactants in the Inhibition of Candida albicans

Photodynamic therapy (PDT) has been originally developed for the treatment of cancer, but it has been successfully employed in the treatment of infectious diseases, including fungal infections. Surfactants are amphiphilic compounds that also have antifungal properties. The present work demonstrates the synergic effect of PDT with methylene blue (MB) and LED combined with four different surfactants in the killing of Candida albicans. Subinhibitory concentrations of CTAC, HPS, SDS and Triton X-100 were tested with MB PDT. The combined therapies proved to be more efficient than PDT or surfactants separately. The best results were obtained with CTAC and HPS and PDT with MB at the concentration of 32 μg/mL. In conclusion, the combination of surfactants and PDT is an alternative antifungal treatment that can achieve more effective performance with minimal discomfort to the patient.     

Interaction of giant extracellular Glossoscolex paulistus hemoglobin (HbGp) with ionic surfactants: a MALDI-TOF-MS study

The giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) is constituted by approximately 144 subunits containing heme groups with molecular masses in the range of 16-19kDa forming a monomer (d) and a trimer (abc), and around 36 non-heme structures, named linkers (L). Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-MS) analysis was performed recently, to obtain directly information on the molecular masses of the different subunits from HbGp in the oxy-form. This technique demonstrated structural similarity between HbGp and the widely studied hemoglobin of Lumbricus terrestris (HbLt). Indeed, two major isoforms (d(1) and d(2)) of identical proportions with masses of 16,355+/-25 and 16,428+/-24Da, respectively, and two minor isoforms (d(3) and d(4)) with masses around 16.6kDa were detected for monomer d of HbGp. In the present work, the effects of anionic sodium dodecyl sulfate (SDS) and cationic cethyltrimethylammonium chloride (CTAC) on the oligomeric structure of HbGp have been studied by MALDI-TOF-MS in order to evaluate the interaction between ionic surfactants and HbGp. The data obtained with this technique show an effective interaction of cationic surfactant CTAC with the two isoforms of monomer d, d(1) and d(2), both in the whole protein as well as in the pure isolated monomer. The results show that up to 10 molecules of CTAC are bound to each isoform of the monomer. Differently, the mass spectra obtained for SDS-HbGp system showed that the addition of the anionic surfactant SDS does not originate any mass increment of the monomeric subunits, indicating that SDS-HbGp interaction is, probably, significantly less effective as compared to CTAC-HbGp one. The acid pI of the protein around 5.5 is, probably, responsible for this behavior. The results of this work suggest also some interaction of both surfactants with linker chains as well as with trimers, as judged from observed mass increments. Our data are consistent with a recent spectroscopic study showing a strong interaction between CTAC and HbGp at physiological pH [P.S.Santiago, et al, Biochim. Biophys. Acta 1770 (2007) 506-517.].