19 research outputs found
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED) due to AIRET16M mutation in a consanguineous Greek girl
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED) or autoimmune polyendocrine syndrome type 1 (APS-1) is a rare autosomal recessive disease caused by mutations of the AutoImmune REgulator (AIRE) gene, an important mediator of tolerance to self-antigens. It is characterized by two out of three major components: chronic mucocutaneous candidiasis, hypoparathyroidism and Addison's disease. We present an 11-year-old girl suffering from recurrent episodes of mucocutaneous candidiasis and onychomycosis from 1 to 6years of age, and transient alopecia at the age of 4years. Hypoparathyroidism and dental enamel hypoplasia were diagnosed at 8years. Autoantibodies to thyroid and adrenal glands were not detected and all other endocrine functions have remained normal. Genetic analysis revealed that the patient was homozygous for the mutation T16M in exon 1 of the AIRE gene (p.T16M, c.47C>T). This is the first APECED case reported for carrying this mutation in homozygous form. Parents were third cousins and heterozygous carriers of this mutatio
Species-Dependent Differences in Virulence of Medically Important Zygomycetes in Neutropenic Hosts are Related to Sporangiospore Germination, Hyphal Metabolism, and Circulating Molecular Biomarker Levels
Risk factors for nasopharyngeal carriage of drug-resistant Streptococcus pneumoniae: data from a nation-wide surveillance study in Greece
<p>Abstract</p> <p>Background</p> <p>A nation-wide surveillance study was conducted in Greece in order to provide a representative depiction of pneumococcal carriage in the pre-vaccination era and to evaluate potential risk factors for carriage of resistant strains in healthy preschool children attending daycare centers.</p> <p>Methods</p> <p>A study group was organized with the responsibility to collect nasopharyngeal samples from children. Questionnaires provided demographic data, data on antibiotic consumption, family and household data, and medical history data. Pneumococcal isolates were tested for their susceptibility to various antimicrobial agents and resistant strains were serotyped.</p> <p>Results</p> <p>Between February and May 2004, from a total population of 2536 healthy children, a yield of 746 pneumococci was isolated (carriage rate 29.41%). Resistance rates differed among geographic regions. Recent antibiotic use in the last month was strongly associated with the isolation of resistant pneumococci to a single or multiple antibiotics. Serotypes 19F, 14, 9V, 23F and 6B formed 70.6% of the total number of resistant strains serotyped.</p> <p>Conclusion</p> <p>Recent antibiotic use is a significant risk factor for the colonization of otherwise healthy children's nasopharynx by resistant strains of <it>S pneumoniae</it>. The heptavalent pneumococcal conjugate vaccine could provide coverage for a significant proportion of resistant strains in the Greek community. A combined strategy of vaccination and prudent antibiotic use could provide a means for combating pneumococcal resistance.</p
Heparin effect on tumor cell growth and metastasis
Heparin multiple biological properties, such as anticoagulative activity, binding to extracellular matrix proteins, interaction with angiogenic growth factors, modulation of the activity of certain degradative enzymes and inhibition of growth of various cell lines, are likely to affect crucial phases in the evolution of the neoplastic disease. In order to investigate heparin effect on tumor growth and metastasis, we performed two series of experiments, in vitro and in vivo, using SW480 human colon adenocarcinoma cells. We first studied heparin effects in vitro on cell growth, colony formation in soft agar, CEA and CA19-9 tumor marker release, cell adhesiveness in wells precoated with extracellular matrix proteins (laminin, fibronectin and collagen type IV), and cell migration and invasiveness in Transwell chamber filters precoated with the proteins mentioned. We also investigated the effects of low-dose heparin treatment on the growth of SW480 cells subcutaneously injected in nude mice, on the vascularization and other pathological features of the tumors developed, on metastasis formation and finally on the morphology and karyotype of SW480 cells in histocultures performed from the tumors. Heparin didn't affect cell growth in vitro, while it altered, at high concentrations, the morphology of colonies formed in soft agar, and reduced the amount of CA19-9 released in the supernatant of the cell cultures. It also inhibited, in a dose-dependent manner, SW480 cell adhesion and migration to the proteins tested, although it didn't significantly affect cell invasion of collagen type IV precoated filters. A non statistically significant increase of tumor growth (0.05<p<0.1) was observed in heparin treated animals compared to the control group. Tumor vascularization was moderately increased in two of the six animals of the heparin group, while metastasis was lot inhibited. Tumor pathological features and SW480 cell morphology and karyotype were not iffected by heparin treatment. In conclusion, some crucial steps of the metastastic process, such as tumor cell adhesion and migration to certain extracellular matrix proteins, were inhibited by heparin in vitro, while SW480 cell biological behaviour in vivo was not significantly affected. These results do not suggest a role for low-dose heparin treatment in the prevention of colon cancer growth and metastasis in vivo. In contrast, the experimental use of chemically modified heparin species, which would selectively exhibit some of the multiple biological properties of this glycosaminoglycan, might be helpful in the planning of new therapeutic strategies for cancer patients.Οι πολλαπλές βιολογικές ιδιότητες της ηπαρίνης, όπως η αντιπηκτική δράση, η ικανότητα σύνδεσης με εξωκυττάριες πρωτεΐνες, η αλληλεπίδραση με αγγειογενετικούς αυξητικούς παράγοντες, η τροποποίηση της δράσης ορισμένων αποικοδομητικών ενζύμων και η αναστολή της ανάπτυξης διαφόρων κυτταρικών σειρών, είναι πιθανό ότι επηρεάζουν κρίσιμες φάσεις της εξέλιξης της νεοπλασματικής νόσου. Με σκοπό τη μελέτη της επίδρασης της ηπαρίνης στην ανάπτυξη και μετάσταση των καρκινικών κυττάρων, πραγματοποιήθηκαν δύο σειρές πειραμάτων, in vitro και in vivo, στα οποία χρησιμοποιήθηκαν τα κύτταρα της σειράς SW480 αδενοκαρκινώματος του παχέος εντέρου του ανθρώπου. Μελετήθηκε η επίδραση του φαρμάκου in vitro στην κυτταρική ανάπτυξη, την κλωνογενή ικανότητα σε άγαρ, την παραγωγή των δεικτών CEA και CA 19-9, την προσκολλητικότητα των κυττάρων σε φιαλίδια επικαλυμμένα με πρωτεΐνες του εξωκυττάριου χώρου (λαμινίνη, ινονεκτίνη, κολλαγόνο IV), και τη μεταναστευτική και διηθητική τους ικανότητα σε φίλτρα δίχωρων φιαλιδίων (Transwells) επικαλυμμένα με τις πρωτεΐνες αυτές. Επίσης, μελετήθηκε η επίδραση της ηπαρίνης, σε χαμηλή δόση, στην ανάπτυξη των υποδόρια ενοφθαλμισθέντων καρκινικών κυττάρων σε αθυμικούς ποντικούς, την αγγειοβρίθεια και τα άλλα παθολογοανατομικά χαρακτηριστικά των αναπτυχθέντων όγκων, το σχηματισμό μεταστάσεων, και τα μορφολογικά και καρυοτυπικά χαρακτηριστικά των ανακαλλιεργηθέντων από τους όγκους κυττάρων SW480. Η ηπαρίνη δεν επηρέασε την κυτταρική ανάπτυξη in vitro, αλλά μετέβαλε, σε υψηλές συγκεντρώσεις, τη μορφολογία των αποικιών σε άγαρ και ελάττωσε την παραγωγή του αντιγόνου CA19-9. Επίσης, ανέστειλε, κατά δοσοεξαρτώμενο τρόπο, την προσκολλητική και μεταναστευτική ικανότητα των κυττάρων στις πρωτεΐνες που μελετήθηκαν, ενώ δεν επηρέασε την ικανότητα διήθησης του κολλαγόνου IV. Η αύξηση του μεγέθους των όγκων που παρατηρήθηκε στα πειραματόζωα που ελάμβαναν ηπαρίνη, σε σχέση με τους μάρτυρες, δεν τεκμηριώθηκε στατιστικά (0,05<p<0,1). Η αγγειοβρίθεια ήταν σχετικά αυξημένη σε δύο από τους έξι όγκους της ομάδας της ηπαρίνης, ενώ δεν σημειώθηκε αναστολή των μεταστάσεων. Τα υπόλοιπα ευρήματα (παθολογοανατομικά των όγκων, μορφολογικά και καρυοτυπικά των ανακαλλιεργηθέντων κυττάρων) δεν μεταβλήθηκαν παρουσία ηπαρίνης. Συμπερασματικά, η ηπαρίνη ανέστειλε in vitro τις κρίσιμες για τη μετάσταση φάσεις της προσκόλλησης και μετανάστευσης των κυττάρων SW480 σε ορισμένες από τις εξωκυττάριες πρωτεΐνες, αλλά δεν επηρέασε σημαντικά τη βιολογική τους συμπεριφορά in vivo. Συνεπώς, δεν φαίνεται να έχει θέση η χορήγηση της σε χαμηλές δόσεις, in vivo, για την αναστολή της ανάπτυξης και μετάστασης του καρκίνου του παχέος εντέρου. Προτείνεται η παρασκευή και πειραματική χρήση "παραλλαγμένων" μορφών ηπαρίνης, που να διαθέτουν εκλεκτικά ορισμένες από τις πολλαπλές βιολογικές της ιδιότητες
A Rare Case of Clavicle Osteomyelitis in a Child and Literature Review
Acute clavicle osteomyelitis in children is rare representing <3% of osteomyelitis cases. We treated a 12-year-old boy who presented with acute pain in the right clavicle and high fever for 4 days. MRI showed abnormal signal in the right clavicle with periosteal reaction. Staphylococcus aureus isolated from blood was susceptible to methicillin, clindamycin, and macrolides. Clindamycin was given intravenously for 3 wks and orally for another 3 wks with no recurrence. We reviewed clavicle osteomyelitis cases in children searching PubMed English literature. From a total of 89 studies retrieved, only 6 fulfilled the criteria and were analyzed. Sixteen patients (56% female) were included with a median age of 9 yrs (range 2 wks–16 yrs). Osteomyelitis was hematogenous in most cases, with S. aureus being the most frequent cause, isolated from either blood or tissue. Symptoms included fever, swelling, and localized bone tenderness. Antimicrobial therapy lasted for 4–12 weeks (median 7.5). Three patients required drainage or curettage. Recurrence occurred in 1/16 cases (6.2%) and persistence of symptoms occurred to 2/16 cases (12.5%) reported before 90s with unknown antimicrobial susceptibility of the pathogen. Acute clavicle osteomyelitis mainly affects older children and has generally good prognosis. Staphylococcus aureus is most commonly implicated and surgery may be needed
Concentration-Dependent Effects of Caspofungin on the Metabolic Activity of Aspergillus Species
The minimum effective concentration (MEC) used to assess the in vitro antifungal activity of caspofungin against Aspergillus spp. is a qualitative endpoint requiring microscopic examination of hyphae. We therefore developed a tool for the quantitative assessment of caspofungin activity against Aspergillus spp. at clinically applicable concentrations. Susceptibility to caspofungin (0.008 to 8 μg/ml) was studied for 9 A. fumigatus, 8 A. flavus, and 12 A. terreus isolates based on the Clinical and Laboratory Standards Institute M38-A protocol. After 48 h of incubation, the MEC was defined microscopically, and metabolic activity assessed with a modified XTT assay, using 100 μg of the tetrazolium salt XTT/ml and 6.25 μM menadione. A significant reduction in metabolic activity was demonstrated at the MEC (0.25 to 0.5 μg/ml) for all Aspergillus spp. and was more pronounced for A. flavus (median metabolic activity, 25% of control) compared to A. fumigatus and A. terreus (median metabolism, 42 and 53%, respectively), allowing determination of MEC with the XTT assay (93 to 100% agreement with microscopic MEC). Fungal metabolism tended to reach the lowest levels (median, 17 to 38% of control) one to two dilutions higher than the MEC, at the minimum metabolic activity concentration (MMC). For 5 of 9 A. fumigatus isolates, 6 of 12 A. terreus isolates, and 1 of 8 A. flavus isolates, a paradoxical increase in metabolism was observed at concentrations greater than the MMC. Sigmoid (E(max)) or bell-shaped models described accurately (median R(2) = 0.97) the concentration-dependent metabolic changes in the absence or presence, respectively, of paradoxical response. Assessment of metabolic activity may provide useful quantitative endpoints for in vitro studies of caspofungin against Aspergillus spp
Comparative In Vitro Pharmacodynamics of Caspofungin, Micafungin, and Anidulafungin against Germinated and Nongerminated Aspergillus Conidia▿
The concentration-dependent effects of echinocandins on the metabolic activity of Aspergillus spp. were comparatively studied by using nongerminated and germinated conidia. The susceptibilities of 11 Aspergillus fumigatus, 8 A. terreus and 8 A. flavus isolates to caspofungin, micafungin, and anidulafungin were studied by a CLSI (formerly NCCLS) M38-A broth microdilution-based method. After 48 h of incubation the minimum effective concentration (MEC) was defined microscopically. Metabolic activity was assessed by the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide assay and modeled by using the sigmoid (Emax) or “bell-shaped” model. The median MEC values of caspofungin (0.5 to 1 μg/ml), micafungin (0.06 to 0.12 μg/ml), and anidulafungin (0.03 μg/ml) against nongerminated conidia increased by 0 to 1, 1 to 2, and 2 to 3 twofold dilutions, respectively (depending on the species), over those against germinated conidia. A similar shift to the right was demonstrated for the corresponding curves of metabolic activity. There was a significant correlation between the degrees of maximal metabolic inhibition caused by different echinocandins at both the species level (greater inhibition for A. flavus) and the strain level (r = 0.84 to 0.93; P < 0.0001). Paradoxical increases in metabolism in the presence of higher concentrations of caspofungin, micafungin, and anidulafungin were detected in 6, 2, and 5 of the A. fumigatus isolates, respectively; 5, 1, and 2 of the A. terreus isolates, respectively; and 1, 0, and 0 of the A. flavus isolates, respectively. Based on the model, 50% of the maximal paradoxical increase was detected with 4.2, 11.1, and 10.8 μg/ml of caspofungin, micafungin, and anidulafungin, respectively. All echinocandins therefore exerted comparable levels of maximal metabolic inhibition against Aspergillus spp. at concentrations that were differentially increased for germinated versus nongerminated conidia. The paradoxical increase in metabolism occurred more frequently and at lower concentrations with caspofungin than with micafungin and anidulafungin
Serum and Cerebrospinal Fluid Levels of Colistin in Pediatric Patients▿
Using a liquid chromatography-tandem mass spectrometry method, the serum and cerebrospinal fluid (CSF) concentrations of colistin were determined in patients aged 1 months to 14 years receiving intravenous colistimethate sodium (60,000 to 225,000 IU/kg of body weight/day). Only in one of five courses studied (a 14-year-old receiving 225,000 IU/kg/day) did serum concentrations exceed the 2 μg/ml CLSI/EUCAST breakpoint defining susceptibility to colistin for Pseudomonas and Acinetobacter. CSF colistin concentrations were <0.2 μg/ml but increased in the presence of meningitis (∼0.5 μg/ml or 34 to 67% of serum levels)
Activities of Triazole-Echinocandin Combinations against Candida Species in Biofilms and as Planktonic Cells▿†
Biofilm formation complicates the treatment of various infections caused by Candida species. We investigated the effects of simultaneous or sequential combinations of two triazoles, voriconazole (VRC) and posaconazole (PSC), with two echinocandins, anidulafungin (AND) and caspofungin (CAS), against Candida albicans and Candida parapsilosis biofilms in comparison to their planktonic counterparts. Antifungal activity was assessed by the 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]2H-tetrazolium-5-carboxanilide (XTT) metabolic assay. Antifungal-agent interactions were analyzed by the Bliss independence model in the simultaneous-treatment studies and by analysis of variance (ANOVA) in the sequential-treatment studies. Against C. albicans planktonic cells, the simultaneous combination of PSC (32 to 128 mg/liter) and CAS (0.008 to 0.25 mg/liter) was synergistic; the combinations of PSC (128 to 1,024 mg/liter) with AND (0.03 to 0.5 mg/liter) and VRC (32 to 512 mg/liter) with AND (0.008 to 0.03 mg/liter) were antagonistic. Against C. parapsilosis planktonic cells, the interaction between VRC (32 to 1,024 mg/liter) and CAS (1 to 16 mg/liter) was antagonistic. All simultaneous antifungal combinations demonstrated indifferent interactions against biofilms of both Candida species. Damage to biofilms of both species increased (P < 0.01) in the presence of subinhibitory concentrations of echinocandins (0.008 to 0.064 mg/liter), followed by the addition of PSC (512 mg/liter for C. albicans and 64 to 512 mg/liter for C. parapsilosis) or VRC (256 to 512 mg/liter for C. albicans and 512 mg/liter for C. parapsilosis). Triazole-echinocandin combinations do not appear to produce antagonistic effects against Candida sp. biofilms, while various significant interactions occur with their planktonic counterparts