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1.
BMC Infect Dis ; 18(1): 362, 2018 08 02.
Article in English | MEDLINE | ID: mdl-30071836

ABSTRACT

BACKGROUND: Infection with Borrelia burgdorferi sensu lato complex (B. b. sl) spirochetes can cause Lyme borreliosis, manifesting as localized infection (e.g. erythema migrans) or disseminated disease (e.g. Lyme neuroborreliosis). Generally, patients with disseminated Lyme borreliosis will produce an antibody response several weeks post-infection. So far, no case of neuroborreliosis has been described with persistently negative serology one month after infection. CASE PRESENTATION: We present a patient with a history of Mantle cell lymphoma and treatment with R-CHOP (rituximab, doxorubicine, vincristine, cyclofosfamide, prednisone), with a meningo-encephalitis, who was treated for a suspected lymphoma relapse. However, no malignant cells or other signs of malignancy were found, and microbial tests did not reveal any clues, including Borrelia serology. He did not recall being bitten by ticks, and a Borrelia PCR on CSF was negative. After spontaneous improvement of symptoms, he was discharged without definite diagnosis. Several weeks later, he was readmitted with a relapse of symptoms of meningo-encephalitis. This time however, a Borrelia PCR on CSF was positive, confirmed by two independent laboratories, and the patient received ceftriaxone upon which he partially recovered. Interestingly, during the diagnostic process of this exceptionally difficult case, a variety of different serological assays for Borrelia antibodies remained negative. Only P41 (flagellin) IgG was detected by blot and the Liaison IgG became equivocal 2 months after initial testing. CONCLUSIONS: To the best of our knowledge this is the first case of neuroborreliosis that is seronegative on repeated sera and multiple test modalities. This unique case demonstrates the difficulty to diagnose neuroborreliosis in severely immunocompromised patients. In this case, a delay in diagnosis was caused by broad differential diagnosis, an absent known history of tick bites, negative serology and the low sensitivity of PCR on CSF. Therefore, awareness of the diagnostic limitations to detect Borrelia infection in this specific patient category is warranted.


Subject(s)
Immunocompromised Host , Lyme Neuroborreliosis , Lymphoma, Mantle-Cell , Humans , Lyme Neuroborreliosis/complications , Lyme Neuroborreliosis/immunology , Lymphoma, Mantle-Cell/complications , Lymphoma, Mantle-Cell/drug therapy , Male
2.
Thorax ; 72(9): 803-810, 2017 09.
Article in English | MEDLINE | ID: mdl-28100714

ABSTRACT

RATIONALE: Ventilator-associated pneumonia (VAP) is the most common nosocomial infections in patients admitted to the ICU. The adapted island model predicts several changes in the respiratory microbiome during intubation and mechanical ventilation. OBJECTIVES: We hypothesised that mechanical ventilation and antibiotic administration decrease the diversity of the respiratory microbiome and that these changes are more profound in patients who develop VAP. METHODS: Intubated and mechanically ventilated ICU-patients were included. Tracheal aspirates were obtained three times a week. 16S rRNA gene sequencing with the Roche 454 platform was used to measure the composition of the respiratory microbiome. Associations were tested with linear mixed model analysis and principal coordinate analysis. MEASUREMENTS AND MAIN RESULTS: 111 tracheal aspirates were obtained from 35 patients; 11 had VAP, 18 did not have VAP. Six additional patients developed pneumonia within the first 48 hours after intubation. Duration of mechanical ventilation was associated with a decrease in α diversity (Shannon index; fixed-effect regression coefficient (ß): -0.03 (95% CI -0.05 to -0.005)), but the administration of antibiotic therapy was not (fixed-effect ß: 0.06; 95% CI -0.17 to 0.30). There was a significant difference in change of ß diversity between patients who developed VAP and control patients for Bray-Curtis distances (p=0.03) and for Manhattan distances (p=0.04). Burkholderia, Bacillales and, to a lesser extent, Pseudomonadales positively correlated with the change in ß diversity. CONCLUSION: Mechanical ventilation, but not antibiotic administration, was associated with changes in the respiratory microbiome. Dysbiosis of microbial communities in the respiratory tract was most profound in patients who developed VAP.


Subject(s)
Intensive Care Units , Microbiota/genetics , Pneumonia, Ventilator-Associated/microbiology , Respiration, Artificial/adverse effects , Respiratory System/microbiology , Adult , Aged , Anti-Bacterial Agents/pharmacology , Dysbiosis/microbiology , Female , Genetic Variation/drug effects , Humans , Intubation, Intratracheal , Male , Microbiota/drug effects , Middle Aged , Pneumonia, Bacterial/microbiology , Pneumonia, Bacterial/transmission , RNA, Ribosomal, 16S/genetics , Trachea/microbiology
3.
BMC Infect Dis ; 15: 336, 2015 Aug 14.
Article in English | MEDLINE | ID: mdl-26271750

ABSTRACT

BACKGROUND: Human Rhinovirus (HRV) is responsible for the majority of common colds and is frequently accompanied by secondary bacterial infections through poorly understood mechanisms. We investigated the effects of experimental human HRV serotype 16 infection on the upper respiratory tract microbiota. METHODS: Six healthy volunteers were infected with HRV16. We performed 16S ribosomal RNA-targeted pyrosequencing on throat swabs taken prior, during and after infection. We compared overall community diversity, phylogenetic structure of the ecosystem and relative abundances of the different bacteria between time points. RESULTS: During acute infection strong trends towards increases in the relative abundances of Haemophilus parainfluenzae and Neisseria subflava were observed, as well as a weaker trend towards increases of Staphylococcus aureus. No major differences were observed between day-1 and day 60, whereas differences between subjects were very high. CONCLUSIONS: HRV16 infection is associated with the increase of three genera known to be associated with secondary infections following HRV infections. The observed changes of upper respiratory tract microbiota could help explain why HRV infection predisposes to bacterial otitis media, sinusitis and pneumonia.


Subject(s)
Picornaviridae Infections/microbiology , Respiratory Tract Infections/microbiology , Rhinovirus , Adolescent , Adult , Female , Haemophilus parainfluenzae/isolation & purification , Humans , Male , Microbiota , Middle Aged , Neisseria/isolation & purification , Pharynx/microbiology , RNA, Ribosomal, 16S/analysis , Staphylococcus aureus/isolation & purification , Young Adult
4.
Clin Microbiol Infect ; 21(4): 368.e11-20, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25658524

ABSTRACT

To provide better care for patients suspected of having Lyme borreliosis (LB) we founded the Amsterdam Multidisciplinary Lyme borreliosis Center (AMLC). The AMLC reflects a collaborative effort of the departments of internal medicine/infectious diseases, rheumatology, neurology, dermatology, medical microbiology and psychiatry. In a retrospective case series, characteristics of 200 adult patients referred to the AMLC were recorded, and patients were classified as having LB, post-treatment LB syndrome (PTLBS), persistent Borrelia burgdorferi sensu lato (s.l.) infection despite antibiotic treatment or no LB. In addition, LB, PTLBS and persistent B. burgdorferi s.l. infection cases were classified as 'definite,' 'probable' or 'questionable.' Of the 200 patients, 120 (60%) did not have LB and 31 (16%) had a form of localized or disseminated LB, of which 12 were classified as definite, six as probable and 13 as questionable. In addition, 34 patients (17%) were diagnosed with PTLBS, of which 22 (11%) were probable and 12 (6%) questionable. A total of 15 patients (8%) were diagnosed with persistent B. burgdorferi s.l. infection, of which none was classified as definite, three as probable and 12 as questionable. In conclusion, in line with previous studies, the number of definite and probable (persisting) LB cases was low. The overall high number of questionable cases illustrates the fact that it can sometimes be challenging to either rule out or demonstrate an association with a B. burgdorferi s.l. infection, even in an academic setting. Finally, we were able to establish alternative diagnoses in a large proportion of patients.


Subject(s)
Borrelia burgdorferi Group/isolation & purification , Lyme Disease/diagnosis , Lyme Disease/pathology , Academic Medical Centers , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Netherlands , Retrospective Studies , Young Adult
5.
Toxicol In Vitro ; 29(4): 741-61, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25701760

ABSTRACT

A number of in vitro test methods using Reconstructed human Tissues (RhT) are regulatory accepted for evaluation of skin corrosion/irritation. In such methods, test chemical corrosion/irritation potential is determined by measuring tissue viability using the photometric MTT-reduction assay. A known limitation of this assay is possible interference of strongly coloured test chemicals with measurement of formazan by absorbance (OD). To address this, Cosmetics Europe evaluated use of HPLC/UPLC-spectrophotometry as an alternative formazan measurement system. Using the approach recommended by the FDA guidance for validation of bio-analytical methods, three independent laboratories established and qualified their HPLC/UPLC-spectrophotometry systems to reproducibly measure formazan from tissue extracts. Up to 26 chemicals were then tested in RhT test systems for eye/skin irritation and skin corrosion. Results support that: (1) HPLC/UPLC-spectrophotometry formazan measurement is highly reproducible; (2) formazan measurement by HPLC/UPLC-spectrophotometry and OD gave almost identical tissue viabilities for test chemicals not exhibiting colour interference nor direct MTT reduction; (3) independent of the test system used, HPLC/UPLC-spectrophotometry can measure formazan for strongly coloured test chemicals when this is not possible by absorbance only. It is therefore recommended that HPLC/UPLC-spectrophotometry to measure formazan be included in the procedures of in vitro RhT-based test methods, irrespective of the test system used and the toxicity endpoint evaluated to extend the applicability of these test methods to strongly coloured chemicals.


Subject(s)
Coloring Agents/toxicity , Formazans/toxicity , Skin Irritancy Tests/methods , Animal Testing Alternatives , Chromatography, High Pressure Liquid , Cosmetics/toxicity , Eye Diseases/chemically induced , Humans , Irritants/toxicity , Reproducibility of Results , Skin Diseases/chemically induced , Skin Diseases/pathology , Spectrophotometry, Ultraviolet , Tetrazolium Salts/chemistry , Thiazoles/chemistry
7.
Gene Ther ; 21(12): 1051-7, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25273355

ABSTRACT

Borrelia afzelii is the predominant Borrelia species causing Lyme borreliosis in Europe. Currently there is no human vaccine against Lyme borreliosis, and most research focuses on recombinant protein vaccines against Borrelia burgdorferi sensu stricto. DNA tattooing is a novel vaccination method that can be applied in a rapid vaccination schedule. We vaccinated C3H/HeN mice with B. afzelii strain PKo OspC (outer-surface protein C) using a codon-optimized DNA vaccine tattoo and compared this with recombinant protein vaccination in a 0-2-4 week vaccination schedule. We also assessed protection by DNA tattoo in a 0-3-6 day schedule. DNA tattoo and recombinant OspC vaccination induced comparable total IgG responses, with a lower IgG1/IgG2a ratio after DNA tattoo. Two weeks after syringe-challenge with 5 × 10(5) B. afzelii spirochetes most vaccinated mice had negative B. afzelii tissue DNA loads and all were culture negative. Furthermore, DNA tattoo vaccination in a 0-3-6 day regimen also resulted in negative Borrelia loads and cultures after challenge. To conclude, DNA vaccination by tattoo was fully protective against B. afzelii challenge in mice in a rapid vaccination protocol, and induces a favorable humoral immunity compared to recombinant protein vaccination. Rapid DNA tattoo is a promising vaccination strategy against spirochetes.


Subject(s)
Antigens, Bacterial/immunology , Bacterial Outer Membrane Proteins/immunology , Bacterial Vaccines/immunology , Borrelia burgdorferi Group , Lyme Disease/prevention & control , Vaccination/methods , Vaccines, DNA/immunology , Animals , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Antigens, Bacterial/genetics , Bacterial Outer Membrane Proteins/genetics , Bacterial Vaccines/genetics , DNA, Bacterial/genetics , Lyme Disease/immunology , Mice , Mice, Inbred C3H , Vaccines, DNA/genetics
8.
Toxicol In Vitro ; 27(5): 1476-88, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23524228

ABSTRACT

Cosmetics Europe, The Personal Care Association, known as Colipa before 2012, conducted a program of technology transfer and assessment of Within/Between Laboratory (WLV/BLV) reproducibility of the SkinEthic™ Reconstituted Human Corneal Epithelium (HCE) as one of two human reconstructed tissue eye irritation test methods. The SkinEthic™ HCE test method involves two exposure time treatment procedures - one for short time exposure (10 min - SE) and the other for long time exposure (60 min - LE) of tissues to test substance. This paper describes pre-validation studies of the SkinEthic™ HCE test method (SE and LE protocols) as well as the Eye Peptide Reactivity Assay (EPRA). In the SE WLV study, 30 substances were evaluated. A consistent outcome with respect to viability measurement across all runs was observed with all substances showing an SD of less than 18%. In the LE WLV study, 44 out of 45 substances were consistently classified. These data demonstrated a high level of reproducibility within laboratory for both the SE and LE treatment procedures. For the LE BLV, 19 out of 20 substances were consistently classified between the three laboratories, again demonstrating a high level of reproducibility between laboratories. The results for EPRA WLV and BLV studies demonstrated that all substances analysed were categorised similarly and that the method is reproducible. The SkinEthic™ HCE test method entered into the experimental phase of a formal ECVAM validation program in 2010.


Subject(s)
Animal Testing Alternatives , Cosmetics/toxicity , Irritants/toxicity , Epithelium, Corneal/drug effects , Europe , Humans , In Vitro Techniques , Laboratories , Reproducibility of Results , Technology Transfer , Toxicity Tests
9.
Toxicol In Vitro ; 27(2): 619-26, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23159500

ABSTRACT

Cosmetics Europe, The Personal Care Association (known as Colipa before 2012), conducted a program of technology transfer and within/between laboratory reproducibility of MatTek Corporation's EpiOcular™ Eye Irritation Test (EIT) as one of the two human reconstructed tissue test methods. This EIT EpiOcular™ used a single exposure period for each chemical and a prediction model based on a cut-off in relative survival [ ≤60%=irritant (I) (GHS categories 2 and 1); >60%=no classification (NC)]. Test substance single exposure time was 30 min with a 2-h post-exposure incubation for liquids and 90 min with an 18-h post-exposure incubation for solids. Tissue viability was determined by tetrazolium dye (MTT) reduction. Combinations of 20 coded chemicals were tested in 7 laboratories. Standardized laboratory documentation was used by all laboratories. Twenty liquids (11 NC/9 I) plus 5 solids (3 NC/2 I) were selected so that both exposure regimens could be assessed. Concurrent positive (methyl acetate) and negative (water) controls were tested in each trial. In all, 298 independent trials were performed and demonstrated 99.7% agreement in prediction (NC/I) across the laboratories. Coefficients of variation for the% survival for tissues from each treatment group across laboratories were generally low. This protocol has entered in 2010 the experimental phase of a formal ECVAM validation program.


Subject(s)
Eye/drug effects , Irritants/toxicity , Toxicity Tests, Acute/methods , Animal Testing Alternatives , Cooperative Behavior , Europe , Humans , In Vitro Techniques , Laboratories , Models, Biological , Reproducibility of Results , Technology Transfer , United States
10.
Eur J Dent Educ ; 16(1): 52-8, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22251327

ABSTRACT

BACKGROUND: Clinical experience is important in undergraduate dental education, but (suitable) patients to learn from are often lacking. Online case-based discussions were introduced to overcome patient dependency and to synchronize theoretical with clinical education. MATERIALS AND METHODS: Undergraduate dental students in groups of 5-7 discussed online clinical case reports presenting either minor (2nd year) or complex periodontal pathology (3rd year). Each case consisted of a brief patient history, extra- and intra-oral clinical pictures, periodontal chart, peri-apical and/or orthopantomographic radiographs. Students had to discuss diagnosis and treatment planning. Questionnaires assessed students' and supervisors' general appreciation (score on 20), time investment and opinions about organisation, relation case/course content, future planning, learning effect and online environment (5-point Likert scale). A crossover design with three tests (pre-test, test in between and post-test) was used to investigate whether the frequency of case introduction (one case per week vs. one case element per week) had an effect on learning. Data was analysed with descriptive statistics (questionnaires) and repeated measures ANOVA (crossover design). RESULTS: Students (n=119) and supervisors (n=9) highly appreciated the exercise. Students reported spending on average 74 min per week to read a case, prepare and post messages. Supervisors' total time investment was 342 min per semester to create a case, provide online feedback and to prepare a live-discussion. No significant differences in test-scores were found between the two modalities of case introduction. CONCLUSION: Online case-based discussions, in conjunction with a theoretical course, are valuable additions to the dental curriculum, especially to reinforce the transition from theory to clinical practice.


Subject(s)
Education, Dental/methods , Online Systems , Periodontal Diseases/prevention & control , Adult , Analysis of Variance , Cross-Over Studies , Curriculum , Educational Measurement , Female , Humans , Male , Models, Educational , Surveys and Questionnaires
11.
Toxicol In Vitro ; 22(5): 1285-96, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18406103

ABSTRACT

A previous 'in house' validation study showed that the SMI assay can be used as an alternative to the in vivo Draize eye irritation test. The aim of this multi-centre study with four participating laboratories was to assess the transferability and inter-laboratory variability of the assay using 20 reference chemicals covering the whole irritancy range. The eye irritation potency of the chemicals was assessed by measuring the amount of mucus produced during a 60-min contact period with a 1% dilution, and a second 60-min treatment with a 3.5% dilution. After each contact period the protein release from the mucosal surface was measured. Linear discriminant equations were used to convert the results into the corresponding EU eye irritation categories (NI, R36 and R41). All the non-irritants were predicted correctly by the four laboratories resulting in a 100% specificity. For the R36 compounds a correct classification rate of 89% (VITO) and 100% (SPL, JNJ and UGent) was obtained. The R41 compounds were classified correctly in 78% of the cases for VITO, 89% for SPL and JNJ and 100% for UGent. We can conclude that the SMI assay is a relevant, easily transferable and reproducible alternative to predict the eye irritation potency of chemicals.


Subject(s)
Animal Use Alternatives , Eye/drug effects , Irritants/toxicity , Mollusca/physiology , Mucus/metabolism , Skin/drug effects , Animals , Disease Models, Animal , Dose-Response Relationship, Drug , Eye/pathology , Irritants/classification , L-Lactate Dehydrogenase/analysis , Mucus/enzymology , Predictive Value of Tests , Reproducibility of Results , Skin/metabolism , Toxicity Tests
12.
J Appl Microbiol ; 105(3): 733-40, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18341554

ABSTRACT

AIMS: To evaluate the use of the modified Robbins device (MRD) to test disinfection strategies against biofilms that form on oral medical devices and to test the biofilm removal efficacy of NitrAdine, a disinfectant for the maintenance of oral medical devices. METHODS AND RESULTS: Biofilms were grown on discs using the MRD and biofilms formed in this system were used to evaluate the efficacy of NitrAdine and to determine the optimal disinfection conditions. Our data indicate that the use of the MRD allows for the rapid and reproducible formation of high-density biofilms. Determination of the efficacy of NitrAdine revealed high activity against biofilms tested (e.g. >3 log reduction for Candida albicans and Staphylococcus aureus) and allowed the determination of the optimal conditions for its use. CONCLUSION: The high reproducibility and flexibility of the MRD make it an excellent candidate for standardized testing of disinfectants aimed at reducing biofilms on oral medical devices. Using this system, we were able to demonstrate that NitrAdine exhibits high activity against biofilms formed by the micro-organisms tested. SIGNIFICANCE AND IMPACT OF THE STUDY: Our data suggest that our procedure is appropriate for standardized testing of disinfectants aimed at reducing biofilms on oral medical devices.


Subject(s)
Biofilms/drug effects , Denture Cleansers/pharmacology , Disinfectants/pharmacology , Oral Hygiene , Candida albicans/drug effects , Disinfection/methods , Humans , Microbial Sensitivity Tests/methods , Plankton/drug effects
13.
Clin Microbiol Infect ; 12(6): 571-5, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16700707

ABSTRACT

A real-time PCR assay with a DNA purification and inhibition control (internal control; IC) was developed to detect Chlamydophila psittaci DNA in human clinical samples. Novel C. psittaci-specific primers targeting the ompA gene were developed. The IC DNA contained the same primer-binding sites and had the same length and nucleotide content as the C. psittaci DNA amplicon, but had a shuffled probe-binding region. The lower limit of detection was 80 target copies/PCR, corresponding to 6,250 copies/mL in a clinical sample. Specificity was tested using reference strains of 30 bacterial species. No amplification was observed from any of these samples. Respiratory samples from eight patients were positive with this PCR. Six of these patients were confirmed as positive for C. psittaci with serological testing. Two patients had increasing antibody titres, but did not fulfil criteria proposed previously for serologically proven Chlamydia spp. infection. The real-time PCR described in this paper is a sensitive, specific and rapid method to detect C. psittaci DNA in human clinical respiratory samples.


Subject(s)
Chlamydophila psittaci/isolation & purification , Polymerase Chain Reaction/methods , Psittacosis/diagnosis , Psittacosis/microbiology , Animals , Bronchoalveolar Lavage Fluid/microbiology , DNA Primers/chemistry , Enzyme-Linked Immunosorbent Assay/methods , Humans , Pharynx/microbiology , Polymerase Chain Reaction/instrumentation , Sensitivity and Specificity , Sputum/microbiology
14.
Toxicol In Vitro ; 20(1): 1-17, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16019187

ABSTRACT

This multicentre study aimed at evaluating the reliability (reproducibility) and relevance (predictivity) of a new commercially available human corneal epithelial (HCE) model (SkinEthic Laboratories, Nice, France) to assess acute ocular irritation. A prevalidation approach (protocol optimisation, transfer and performance) was followed and at each of the four participating laboratories, 20 coded reference chemicals, covering the whole range of irritancy, were tested. The compounds were applied topically to the HCE cultures and the level of cytotoxicity (tissue viability and histological analysis) was determined. Once a standardised protocol was established, a high level of reproducibility between the laboratories was observed. In order to assess the capability of the HCE model to discriminate between irritants (I) and non-irritants (NI), a classification prediction model (PM) was defined based on a viability cut-off value of 60%. The obtained in vitro classifications were compared with different in vivo classifications (e.g. Globally Harmonised System) which were calculated from individual rabbit data described in the ECETOC data bank. Although an overall concordance of 80% was obtained (sensitivity = 100% and specificity = 56%), the predictivity of the HCE model substantially increased when other sources of in vivo and in vitro data were taken into account.


Subject(s)
Cornea/drug effects , Irritants/toxicity , Toxicity Tests, Acute/methods , Eye , Humans , In Vitro Techniques , Organic Chemicals/toxicity , Predictive Value of Tests , Reproducibility of Results
15.
Toxicol In Vitro ; 17(3): 311-21, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12781210

ABSTRACT

In the present study, reconstructed human epidermis (RHE) was used as an in vitro model to discriminate 1-chloro-2,4-dinitrobenzene (DNCB), nickel sulfate (NiSO(4)), oxazolone (OXA), 2,4-dinitrofluorobenzene (DNFB) and 2,4,6-trinitrobenzenesulfonic acid (TNBS) as skin sensitizers from benzalkonium chloride (BC), benzoic acid (BA) and sodium lauryl sulfate (SLS) as skin irritants. Our criteria were (a) the differential IL-1alpha and IL-8 synthesis and release (b) cytotoxicity assessment by MTT assay. When the RHE are topically treated with the sensitizers, very low levels of extra- and intracellular IL-1alpha are observed although they induce significant cytotoxicity. In contrast, they exhibit a sharp maximum of IL-8 release. In the presence of the tested irritants, we observe the inverse cytokine release profile, although they induce dose-dependent cytotoxicity profiles similar to those observed with the sensitizers. Finally, IL-1alpha mRNA upregulation is observed after topical application of both sensitizers and irritants, but only the latter significantly increase extracellular IL-1alpha. In conclusion, our results suggest that the associated determination of IL-8, with IL-1alpha, and MTT conversion are at least necessary to discriminate and classify, in a single assay, irritant and sensitizing agents and represent a potential in vitro alternative to two classical in vivo assays.


Subject(s)
Biomarkers/analysis , Epidermis/drug effects , Interleukin-1/biosynthesis , Interleukin-8/biosynthesis , Irritants/toxicity , Administration, Topical , Animal Testing Alternatives , Biological Assay/methods , Coloring Agents/administration & dosage , Culture Techniques , Epidermal Cells , Humans , Interleukin-1/metabolism , Interleukin-8/metabolism , Predictive Value of Tests , Skin Irritancy Tests/methods , Tetrazolium Salts/administration & dosage , Thiazoles/administration & dosage
16.
Cell Biol Toxicol ; 16(6): 391-400, 2000.
Article in English | MEDLINE | ID: mdl-11254165

ABSTRACT

The reconstituted human epidermis model SkinEthic was used to evaluate the phototoxicity of topically applied chemicals. For comparison with published data, we first tested a library of 13 nonphototoxic (NPT) and phototoxic (PT) compounds, applied onto SkinEthic reconstituted human epidermal tissues, in a protocol as close as possible to the one described by Liebsch using another skin tissue model. The results showed that, under these nonoptimized conditions, the SkinEthic model was already able to fully discriminate between known NPT and PT compounds. Furthermore, these epidermal tissues being highly resistant to UVA irradiation, it was possible to increase irradiation by (at least) 3-fold without decrease in tissue viability. In such conditions, the phototoxicity assay is much more sensitive, so that the model is expected to be of great interest for the detection not only of strong but also of weak phototoxic compounds.


Subject(s)
Dermatitis, Phototoxic/physiopathology , Dermotoxins/pharmacology , Epidermis/drug effects , Epidermis/radiation effects , Ultraviolet Rays , 4-Aminobenzoic Acid/toxicity , 5-Methoxypsoralen , Adult , Antipruritics/toxicity , Benzophenones/toxicity , Chlorpromazine/toxicity , Coloring Agents/toxicity , Coumarins/toxicity , Cytological Techniques , Dopamine Antagonists/toxicity , Epidermal Cells , Fluorescent Dyes/toxicity , Histidine/toxicity , Humans , In Vitro Techniques , Methoxsalen/analogs & derivatives , Methoxsalen/toxicity , Neutral Red/toxicity , Penicillin G/toxicity , Penicillins/toxicity , Promethazine/toxicity , Rose Bengal/toxicity , Sodium Dodecyl Sulfate/toxicity , Sunscreening Agents/toxicity , Surface-Active Agents/toxicity , Tetracyclines/toxicity
17.
Int J Cosmet Sci ; 22(6): 397-407, 2000 Dec.
Article in English | MEDLINE | ID: mdl-18503427

ABSTRACT

The steroid 5alpha-reductase isoenzymes (5alphaR) transform testosterone into 17beta-hydroxy-5alpha-androstan-3-one (5-dihydrotestosterone, DHT), which exerts a much stronger biological activity than does testosterone. Briefly, the two 5alphaR isoenzymes are differentially expressed in the two major target organs of steroid action, the prostate (isoenzyme 2, 5alphaR2) and the skin (isoenzyme 1, 5alphaR1). We analysed the potential of a human epidermal tissue reconstituted by cell culture (RHE, provided by SkinEthic Laboratories, Nice, France) as a model for assessing 5alphaR activity. The epidermal model was found to express the type-1 (skin) isoform of 5alphaR and thus could be used as an enzyme source for the screening of 5alphaR modulators for dermatological/cosmetic purposes. A reproducible and convenient assay method was developed, allowing both the evaluation of testosterone transformation into DHT (5alphaR activity) and an outlook on the general metabolism process of testosterone. This could be important for the detection of any compound that could act mainly on another target enzyme than 5alphaR. The assay gave evidence of the inhibitory activity of finasteride against type-1 5alphaR, which is now established both in vitro and in clinical studies. In addition to enzyme inhibitors, this in situ cellular assay can detect transcriptional modulators of 5alphaR gene expression, or any compound that could modulate enzyme processing or post-translational activation. RT-PCR analysis of RNA samples from RHE failed to show any notable effect of finasteride, testosterone, or DHT treatment on the expression of 5alphaR1 at the transcriptional level.

18.
Cell Biol Toxicol ; 15(2): 121-35, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10408359

ABSTRACT

An in vitro human reconstructed epidermis model (SkinEthic) used for screening acute and chronic skin irritation potential was validated against in vivo data from skin tolerability studies. The irritation potential of sodium lauryl sulfate (SLS), calcipotriol and trans-retinoic acid was investigated. The in vitro epidermis-like model consists of cultures of keratinocytes from human foreskin on a polycarbonate filter. The modulation of cell viability, the release and gene expression of proinflammatory cytokines, interleukins 1alpha and 8, and morphological changes were evaluated during 3 days as endpoints representative for an inflammatory reaction. The cumulative irritation potential of the topical products was evaluated in a human clinical study by visual scoring and biophysical measurement of inflammatory skin reaction after repeated 24 h applications over 3 weeks under Finn chamber patches. All topical products that were nonirritating in the human study were noncytotoxic and did not induce cytokine expression in the in vitro acute model (day 1 exposure). All irritating controls exhibited specific cell viability and cytokine patterns, which were predictive of the in vivo human data. The ranking of mild to moderate skin irritation potential was based on the lack of cytotoxicity and the presence of cytokine patterns including gene expression specific for each irritant, using the chronic in vitro model (up to 3 days exposure). The human reconstructed epidermis model SkinEthic was shown to be a reliable preclinical tool predicting the irritation potential of topical products. Moreover, it is a useful model in a two-step tiered strategy for screening acute and chronic irritation potential for the selection of vehicles for new topical drugs.


Subject(s)
Calcitriol/analogs & derivatives , Keratinocytes/drug effects , Keratinocytes/radiation effects , Models, Biological , Sodium Dodecyl Sulfate/pharmacology , Tretinoin/pharmacology , Adult , Calcitriol/pharmacology , Humans , Keratinocytes/metabolism , Skin/cytology
19.
Am J Respir Crit Care Med ; 157(3 Pt 1): 950-6, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9517616

ABSTRACT

In order to determine the presence and distribution of Haemophilus influenzae in lung tissue sections, we obtained lung explants from 49 lung transplant recipients with cystic fibrosis (CF) (n = 16), chronic obstructive pulmonary disease (COPD) including emphysema (n = 16), bronchiectasis (n = 5), pulmonary hypertension (n = 9), Langerhans cell histiocytosis (n = 1), and idiopathic pulmonary fibrosis (n = 2). Analysis was done by selective culturing, immunoperoxidase (IP) staining, and by polymerase chain reaction (PCR). H. influenzae was cultured from specimens of the lung explants from one CF and one COPD patient. IP staining of tissue sections was positive in 24 patients (10 CF patients, eight COPD patients, two bronchiectasis patients, and four patients with noninfectious pulmonary diseases). IP-positive tissue sections were PCR-positive, and IP-negative sections were PCR-negative. H. influenzae was more frequently detected in tissue sections of lung explants from CF and COPD patients than from patients with bronchiectasis or noninfectious pulmonary diseases. H. influenzae was diffusely present in the epithelium, the submucosa of the bronchi, the bronchioles, the interstitium, and the alveolar epithelium. H. influenzae was localized extracellularly alone and in bacterial clusters, and was also associated with macrophages in CF patients. The results of this study demonstrate that H. influenzae is often present in the lungs of patients with end-stage pulmonary disease, especially CF and COPD patients. H. influenzae is diffusely present in the respiratory epithelium and subepithelial layers of the lungs of these patients.


Subject(s)
Haemophilus Infections/diagnosis , Haemophilus influenzae/isolation & purification , Lung Diseases/microbiology , Adolescent , Adult , Bronchi/microbiology , Bronchiectasis/microbiology , Bronchitis/microbiology , Child , Chronic Disease , Coloring Agents , Cystic Fibrosis/microbiology , Epithelium/microbiology , Female , Histiocytosis, Langerhans-Cell/microbiology , Humans , Hypertension, Pulmonary/microbiology , Immunoenzyme Techniques , Lung/microbiology , Lung Diseases, Obstructive/microbiology , Macrophages, Alveolar/microbiology , Male , Middle Aged , Mucous Membrane/microbiology , Polymerase Chain Reaction , Pulmonary Alveoli/microbiology , Pulmonary Emphysema/microbiology , Pulmonary Fibrosis/microbiology , Sensitivity and Specificity , Sputum/microbiology
20.
Int J Obes Relat Metab Disord ; 21(10): 860-4, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9347403

ABSTRACT

RATIONALE: A defective central serotonergic neurotransmission has been suggested to result in the concomitant occurrence of an appetite disorder and a disturbed mood. This syndrome was termed carbohydrate carving (CC) obesity. Excessive consumption of carbohydrate-rich snacks would, through a plasma amino acid mediated mechanism, restore serotonergic neurotransmission and thereby relieve the symptoms of atypical depression. OBJECTIVES: To test whether CC obese patients indeed exhibit symptoms of atypical depression, whether these symptoms can be alleviated by carbohydrate-rich snacks and whether they respond differently to the snacks than non-carbohydrate craving (NC) control subjects. Furthermore, we investigated whether differences between CC and NC patients could be related to peripheral metabolic differences. DESIGN: Double blinded, randomized with cross-over. Patients received three types of snacks (100/0/0, 70/29/1 and 35/3/62 energy percent carbohydrate/fat/protein respectively) on three consecutive test days. Before and after snack administration mood and performance were tested and blood samples were obtained. SUBJECTS: 9 CC and 17 NC obese patients, matched for sex, age and body mass index. MEASUREMENTS: Mood states (Profile of Mood States and Visual Analogue Scales) and performance (Bourdon-Wiersma cancellation test), serum glucose and insulin and plasma amino acid concentrations. RESULTS: Before snack consumption, CC patients had slightly higher anger and fatigue scores and tended to have lower mood scores than NC patients. The efficiency of performance increased in both groups after all snacks. No other psychological effects of the snacks were registered. Psychological and metabolic responses of CC and NC patients to the snacks were similar. CONCLUSION: Although they may have a somewhat disturbed mood, CC obese patients do not improve their mood states through ingestion of a carbohydrate-rich snack. It seems, from a therapeutic point of view, useless to maintain the concept of carbohydrate craving.


Subject(s)
Affect/physiology , Appetite , Dietary Carbohydrates , Dietary Fats/administration & dosage , Dietary Proteins/administration & dosage , Obesity/physiopathology , Obesity/psychology , Psychomotor Performance/physiology , Adult , Amino Acids/blood , Blood Glucose/metabolism , Cohort Studies , Cross-Over Studies , Double-Blind Method , Female , Humans , Insulin/blood , Male , Middle Aged
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