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2.
Skin Appendage Disord ; 3(4): 175-178, 2017 Oct.
Article in English | MEDLINE | ID: mdl-29177141

ABSTRACT

Scalp morphea presents as a scarring alopecia in en coup du sabre pattern. We report an unusual presentation of a round hairless patch of morphea on the occipital scalp present for 15 years. The scalp lesion aligned with 2 other hyperpigmented lesions of biopsy-proven morphea in the lower back. Pathology of horizontal sections from the scalp lesion showed follicular dropout, thickening of the collagen bundles, and preserved eccrine and follicular structures. Marked lymphocytic perineural infiltrate, a reported clue to the diagnosis of scalp morphea, contributed to the diagnosis. This case is unusual due to its rare clinical presentation. It also highlights the importance of recognizing histopathological clues for the diagnosis of uncommon scalp disorders.

3.
J Med Life ; 9(4): 424-428, 2016.
Article in English | MEDLINE | ID: mdl-27928449

ABSTRACT

Introduction. Arterial stiffness and vascular calcifications are independent predictors of cardiovascular morbidity and mortality in the chronic kidney disease (CKD) stage 5D population. According to the guidelines, patients on renal replacement therapy represent a very high cardiovascular risk class. Case report. We report the case of a 67-year-old hypertensive male patient, known with CKD stage 5D on hemodialysis (three times per week), secondary bone mineral disease, admitted for progressive right leg pain. The physical examination detected right dorsalis pedis artery pulse absence. Blood biochemistry emphasized hypercalcemia, hyperphosphatemia, increased alkaline phosphatase, metabolic acidosis, hypoalbuminemia, iPTH values above upper limits. The X-ray of right shin highlighted a vascular calcification with a "train track" aspect on the tibial-peroneal artery trunk and the thoracic X-ray (performed with low ray regime) showed calcium deposits in coronary arteries walls. Legs arteriography and coronary angiography were performed revealing multiple lesions on investigated vessels with an 80% narrowing of right coronary artery. The particularity of the case lies in the absence of angina in a chronic hemodialysis patient in whom multiple significant angiographically stenosis of the coronary arteries were found and successful endovascular therapy was performed. Conclusion. The broadening of the indication for coronary angiography should be considered in certain asymptomatic CKD stage 5D patients based on a risk score involving calcium, phosphate, PTH and acid-base imbalances, while considering their major influence on the structure and tone of vascular walls thus on cardiovascular morbidity and mortality rates. Abbreviations. ABI = ankle-brachial index,CAD = coronary artery disease,CKD = chronic kidney disease,CT = computed tomography, EBCT = electron-beam computed tomography,ESRD = end-stage renal disease,GFR = glomerular filtration rate,iPTH = intact parathormon,PCI = percutaneous coronary intervention.


Subject(s)
Coronary Artery Disease/complications , Renal Dialysis , Renal Insufficiency, Chronic/complications , Aged , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Coronary Vessels/diagnostic imaging , Coronary Vessels/pathology , Humans , Male , Renal Insufficiency, Chronic/diagnostic imaging , Risk Factors , Tibia/blood supply , Vascular Calcification/complications
4.
J Med Life ; 9(4): 449-454, 2016.
Article in English | MEDLINE | ID: mdl-27928454

ABSTRACT

Background: Major acid-base variations during dialysis and the imbalances in serum calcium levels intensified by them play a role in cardiovascular damage of hemodialysis patients. Early vascular walls modifications can be objectified by determining the pulse wave velocity (PWV) - a marker of vascular stiffness that is associated with increased risk of cardiovascular events. Material and methods: This was a prospective study conducted on 63 chronic hemodialysis patients with diuresis above 500 mL/ 24 hours and predialysis blood pressure below 160 mmHg (treatment controlled) randomized in two groups for 12 months - the study group receiving interdialitic oral sodium bicarbonate doses and control group, without oral sodium bicarbonate supplementation, but receiving higher bicarbonate prescriptions in dialysis. All the patients were monthly evaluated by biochemical tests (serum calcium, phosphate, iPTH, bicarbonate), the assessment of prescribed doses of phosphate binders being undergone. Two PWV determinations and chest X-ray exams for coronary calcifications were done - at the beginning and end of the study for every patient. Results: In the study group (n = 29), the mean age was 56.48 ± 12.78 years and the average duration of dialysis was 55.51 ± 34.53 months, the mean dialysis bicarbonate was 29.81 ± 1.41 mEq/ L and 27 of them (subgroup 0) had alkaline reserve (AR) 20-22 mEq/ L. The control group (n = 34) had a mean age of 57.35 ± 15.32 years and the mean dialysis duration 59.67 ± 34.79 months, with an average level of dialysis bicarbonate of 33 ± 2.2 mEq/ L necessary to maintain AR within guidelines. Depending on the mean AR obtained, this group was divided into three subgroups (subgroup 1, subgroup 2, and subgroup 3). There were statistically significant differences regarding the necessary of dialysis bicarbonate (p < 0.001), average serum calcium levels (p < 0.001) and serum phosphorus (p < 0.001), as well as PWV mean values and the number of vascular calcifications (p = 0.036) between the study and the control group. The average dose of phosphate binders was significantly higher in the study group (p = 0.01). At the end of the study, the serum iPTH average levels were decreased in the study group (p < 0.001) and significantly increased in the control group (p < 0.001). Conclusions: Avoiding large variations in serum bicarbonate levels is an important step in hemodialysis patients' management because wide acidosis-alkalosis variation can increase cardiovascular risks in terms of altering the vessel walls elasticity and favoring their calcifications. Abbreviations: GFR = glomerular filtration rate,PWV = pulse wave velocity, iPTH = intact parathyroid hormone,AR = alkaline reserve, BP = blood pressure,mEq = milliequivalents,L = liter.


Subject(s)
Acid-Base Equilibrium/drug effects , Cardiovascular System/metabolism , Dietary Supplements , Renal Dialysis , Sodium Bicarbonate/administration & dosage , Sodium Bicarbonate/pharmacology , Administration, Oral , Calcium/blood , Cardiovascular System/drug effects , Female , Humans , Male , Middle Aged , Parathyroid Hormone/blood , Phosphates/blood , Prospective Studies , Pulse Wave Analysis , Vascular Calcification/blood
5.
J Clin Virol ; 79: 12-17, 2016 06.
Article in English | MEDLINE | ID: mdl-27045454

ABSTRACT

BACKGROUND: Rapid antigen detection tests (RADTs) are increasingly used to detect influenza viruses and respiratory syncytial virus (RSV). However, their sensitivity and specificity are a matter of debate, challenging their clinical usefulness. OBJECTIVES: Comparing diagnostic performances of BinaxNow Influenza AB(®) (BNI) and BinaxNow RSV(®) (BNR), to those of real-time reverse transcriptase PCR (RT-PCR), virus isolation and direct immunofluorescence (D-IF) in paediatric patients. STUDY DESIGN: Between November 2005 and September 2013, 521 nasal washings from symptomatic children (age <5 years) attending our tertiary care centre were tested, with a combination of the respective assays using RT-PCR as gold standard. RESULTS: Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of BNI were 69% (confidence interval [CI] [51-83]), 96% [94-97], 55% [39-70] and 98% [96-99] respectively. Of eleven false-negative samples, RT-PCR Ct-values were higher than all RT-PCR positive test results (27 vs 22, p=0.012). Of twenty false-positive samples, none were culture positive and two tested positive in D-IF. Sensitivity, specificity, PPV and NPV for BNR were 79% [73-85], 98% [96-99], 97% [93-99] and 88% [84-91]. Of the 42 false-negative samples the median Ct-value was higher than that of all RT-PCR positive samples (31 vs 23, p<0.0001). Five false-positive samples were detected. Three of these tested positive for RSV in virus isolation and D-IF. CONCLUSIONS: RADTs have a high specificity with BNR being superior to BNI. However, their relative low sensitivity limits their usefulness for clinical decision making in a tertiary care paediatric hospital.


Subject(s)
Antigens, Viral/analysis , Diagnostic Tests, Routine/methods , Influenza, Human/diagnosis , Respiratory Syncytial Virus Infections/diagnosis , Tertiary Healthcare/methods , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Orthomyxoviridae , Predictive Value of Tests , Sensitivity and Specificity , Time Factors
8.
J Clin Virol ; 61(3): 453-5, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25281281

ABSTRACT

We here report a 7 year old acute myeloid leukemia patient with persistent spiking fever likely caused by chronic echovirus 20 infection. After immunoglobulin substitution fevers subsided and the virus was cleared. Enterovirus infection should be considered in immunocompromised patients with unexplained persistent fever.


Subject(s)
Echovirus Infections/diagnosis , Echovirus Infections/pathology , Enterovirus B, Human/isolation & purification , Fever/etiology , Leukemia, Myeloid, Acute/complications , Leukemia, Myeloid, Acute/diagnosis , Child , Humans , Immunocompromised Host , Immunoglobulins, Intravenous/therapeutic use , Leukemia, Myeloid, Acute/pathology , Male , Treatment Outcome
9.
Adv Wound Care (New Rochelle) ; 3(7): 445-464, 2014 Jul 01.
Article in English | MEDLINE | ID: mdl-25032064

ABSTRACT

Significance: Keratinocytes, a major cellular component of the epidermis, are responsible for restoring the epidermis after injury through a process termed epithelialization. This review will focus on the pivotal role of keratinocytes in epithelialization, including cellular processes and mechanisms of their regulation during re-epithelialization, and their cross talk with other cell types participating in wound healing. Recent Advances: Discoveries in epidermal stem cells, keratinocyte immune function, and the role of the epidermis as an independent neuroendocrine organ will be reviewed. Novel mechanisms of gene expression regulation important for re-epithelialization, including microRNAs and histone modifications, will also be discussed. Critical Issues: Epithelialization is an essential component of wound healing used as a defining parameter of a successful wound closure. A wound cannot be considered healed in the absence of re-epithelialization. The epithelialization process is impaired in all types of chronic wounds. Future Directions: A comprehensive understanding of the epithelialization process will ultimately lead to the development of novel therapeutic approaches to promote wound closure.

10.
Wound Repair Regen ; 22(2): 220-227, 2014.
Article in English | MEDLINE | ID: mdl-24635172

ABSTRACT

The epidermis is maintained by epidermal stem cells (ESCs) that reside in distinct niches and contribute to homeostasis and wound closure. Keratinocytes at the nonhealing edges of venous ulcers (VUs) are healing-incompetent, hyperproliferative, and nonmigratory, suggesting deregulation of ESCs. To date, genes which regulate ESC niches have been studied in mice only. Utilizing microarray analysis of VU nonhealing edges, we identified changes in expression of genes harboring regulation of ESCs and their fate. In a prospective clinical study of 10 VUs, we confirmed suppression of the bone morphogenetic protein receptor (BMPR) and GATA binding protein 3 (GATA3) as well as inhibitors of DNA-binding proteins 2 and 4 (ID2 and ID4). We also found decreased levels of phosphorylated glycogen synthase kinase 3 (GSK3), nuclear presence of ß-catenin, and overexpression of its transcriptional target, c-myc, indicating activation of the Wnt pathway. Additionally, we found down-regulation of leucine-rich repeats and immunoglobulin-like domains protein 1 (LRIG1), a gene important for maintaining ESCs in a quiescent state, and absence of keratin 15 (K15), a marker of the basal stem cell compartment suggesting local depletion of ESCs. Our study shows that loss of genes important for regulation of ESCs and their fate along with activation of ß-catenin and c-myc in the VU may contribute to ESC deprivation and a hyperproliferative, nonmigratory healing incapable wound edge.


Subject(s)
Epidermis/pathology , Stem Cell Niche , Varicose Ulcer/pathology , Wound Healing , Animals , DNA-Binding Proteins/metabolism , Down-Regulation , GATA3 Transcription Factor/metabolism , Gene Expression Profiling , Glycogen Synthase Kinase 3/metabolism , Humans , Keratinocytes/metabolism , Male , Membrane Glycoproteins/metabolism , Mice , Prospective Studies , Protein Array Analysis , Varicose Ulcer/immunology , Varicose Ulcer/metabolism , Varicose Ulcer/physiopathology , Wnt Signaling Pathway , beta Catenin/metabolism
11.
Facial Plast Surg Clin North Am ; 21(3): 335-42, 2013 Aug.
Article in English | MEDLINE | ID: mdl-24017975

ABSTRACT

This article is an update of the currently available options for medical therapies to treat androgenetic alopecia in men and women. Emerging novel therapeutic modalities with potential for treating these patients are discussed. Because androgenetic alopecia is progressive in nature, stabilization of the process using medical therapy is an important adjunct to any surgical hair-restoration plan.


Subject(s)
5-alpha Reductase Inhibitors/therapeutic use , Alopecia/therapy , Low-Level Light Therapy , Azasteroids/therapeutic use , Combined Modality Therapy , Dutasteride , Female , Finasteride/therapeutic use , Humans , Low-Level Light Therapy/instrumentation , Low-Level Light Therapy/methods , Male , Minoxidil/therapeutic use , Sex Factors
12.
PLoS One ; 8(2): e56846, 2013.
Article in English | MEDLINE | ID: mdl-23451098

ABSTRACT

Understanding the pathology resulting from Staphylococcus aureus and Pseudomonas aeruginosa polymicrobial wound infections is of great importance due to their ubiquitous nature, increasing prevalence, growing resistance to antimicrobial agents, and ability to delay healing. Methicillin-resistant S. aureus USA300 is the leading cause of community-associated bacterial infections resulting in increased morbidity and mortality. We utilized a well-established porcine partial thickness wound healing model to study the synergistic effects of USA300 and P. aeruginosa on wound healing. Wound re-epithelialization was significantly delayed by mixed-species biofilms through suppression of keratinocyte growth factor 1. Pseudomonas showed an inhibitory effect on USA300 growth in vitro while both species co-existed in cutaneous wounds in vivo. Polymicrobial wound infection in the presence of P. aeruginosa resulted in induced expression of USA300 virulence factors Panton-Valentine leukocidin and α-hemolysin. These results provide evidence for the interaction of bacterial species within mixed-species biofilms in vivo and for the first time, the contribution of virulence factors to the severity of polymicrobial wound infections.


Subject(s)
Methicillin-Resistant Staphylococcus aureus/pathogenicity , Pseudomonas aeruginosa/pathogenicity , Wound Infection/microbiology , Animals , Biofilms/growth & development , Female , Immunohistochemistry , Real-Time Polymerase Chain Reaction , Staphylococcal Infections/metabolism , Swine , Virulence Factors/genetics , Virulence Factors/metabolism , Wound Infection/metabolism
13.
Infection ; 41(1): 77-91, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22847627

ABSTRACT

INTRODUCTION: Since acute respiratory tract infections inflict a high burden of disease in children worldwide, a multiplex reverse transcription polymerase chain reaction combined with a microwell hybridization assay (m-RT-PCR-ELISA) to detect 19 different respiratory pathogens was developed and validated. METHODS: A total of 430 respiratory specimens were retrospectively tested in parallel by both the advanced 19-valent m-RT-PCR-ELISA as well as by culture or individual RT-PCR assays used in clinical routine. RESULTS: The mean (median) sensitivity of the m-RT-PCR-ELISA in the retrospective test was 93.3% (95.1%; range 83.3-100 %), and the mean (median) specificity was 99.8 and 100 % (range 98.6-100 %), respectively. The mean positive predictive value was 99.3 % (range 93.4-100 %) and the mean negative predictive value was 95.3 % (range 98.4-100 %). Feasibility and clinical value of the 19-valent method was prospectively shown on 16,231 incoming clinical specimens from patients between 0 and 16 years of age with acute respiratory tract infections admitted to pediatric hospitals or private practices from October 2003 to June 2010 in three regions in Germany (Kiel, Mainz, Freiburg; Freiburg to June 2007 only). At least one microorganism was detected in 10,765 of 16,231 (66.3 %) clinical specimens: 5,044 RV, 1,999 RSV, 1,286 AV, 944 EV, 737 seasonal IVA, 173 pandemic IVA H1N1-2009, 899 MPV, 518 CV, 383 PIV3, 268 PIV1, 259 Mpn, 205 IVB, 164 PIV2, 144 PIV4, 103 Bp, 29 Cpn and 29 Bpp, while reovirus and Lpn were not present in these specimens from a pediatric population. More than one organism could be detected in 13.4 % of the specimens. CONCLUSIONS: The m-RT-PCR-ELISA evaluated here improves the spectrum for diagnosing respiratory infections and is a feasible instrument for individual diagnostic and epidemiological studies.


Subject(s)
Enzyme-Linked Immunosorbent Assay , Multiplex Polymerase Chain Reaction , Respiratory Tract Infections/diagnosis , Reverse Transcriptase Polymerase Chain Reaction , Humans , Population Surveillance , Reproducibility of Results , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/microbiology , Respiratory Tract Infections/virology , Sensitivity and Specificity
14.
J Surg Res ; 176(2): 701-7, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22440935

ABSTRACT

BACKGROUND: Debridement is one of the crucial steps for successful wound care. In addition to removing necrotic tissue, debridement has been shown to reduce wound-associated bacteria that delay healing. Using an in vivo porcine model, we compared the effects of various methods of debridement, including hydrosurgery and plasma-mediated bipolar radiofrequency ablation (PBRA), on bacterial removal and wound healing. METHODS: One hundred thirty-five deep dermal wounds were inoculated with methicillin resistant Staphylococcus aureus (MRSA) and covered with a polyurethane dressing for 48 h to allow for biofilm formation. Wounds were then treated with either PBRA (at two settings), hydrosurgery, sharp debridement, or no debridement. Biopsies were collected for microbiology and histologic assessment on d 0, 2, 9, and 21 post-treatment. RESULTS: All treatment groups showed a statistically significant reduction in MRSA counts relative to no debridement at all times points (P < 0.05). PBRA at a maximum setting had the lowest MRSA counts at all recovery times and, compared with all other treatment groups, a statistically significant difference was observed on d 21 (P < 0.05). No detrimental effects on the healing process were noted with any of the debridement methods. CONCLUSION: While sharp debridement has been established as the traditional gold standard for rapid removal of necrotic, infected tissue, our results suggest that novel debridement modalities show clinical promise for the treatment of chronic ulcers and burn wounds, especially when bacteria are present.


Subject(s)
Catheter Ablation/methods , Debridement/methods , Methicillin-Resistant Staphylococcus aureus/growth & development , Staphylococcal Skin Infections/prevention & control , Wounds and Injuries/microbiology , Wounds and Injuries/surgery , Animals , Disease Models, Animal , Female , Fibrosis/prevention & control , Hydrotherapy/methods , Leukocytes/cytology , Necrosis/prevention & control , Staphylococcal Skin Infections/pathology , Swine , Wound Healing , Wounds and Injuries/pathology
16.
J Clin Virol ; 47(1): 34-7, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19857993

ABSTRACT

BACKGROUND: Rapid and specific molecular tests for identification of the recently identified pandemic influenza A/H1N1 2009 virus as well as rapid molecular tests to identify antiviral resistant strains are urgently needed. OBJECTIVES: We have evaluated the performance of two novel reverse transcriptase polymerase chain reactions (RT-PCRs) targeting specifically hemagglutinin and neuraminidase of pandemic influenza A/H1N1 virus in combination with a conserved matrix PCR. In addition, we investigated the performance of a novel discrimination RT-PCR for detection of the H275Y resistance mutation in the neuraminidase gene. STUDY DESIGN: Clinical performance of both subtype specific RT-PCR assays was evaluated through analysis of 684 throat swaps collected from individuals meeting the WHO case definition for the novel pandemic influenza virus. Analytical performance was analyzed through testing of 10-fold serial dilutions of RNA derived from the first Dutch sequenced and cultured confirmed case of novel pandemic influenza infection. Specificity and discriminative capacities of the H275Y discrimination assay were performed by testing wild type and recombinant H275Y pandemic influenza. RESULTS: 121 throat swaps collected from April 2009 to July 2009 were positive by at least two out of three RT-PCRs, and negative for the seasonal H3/H1 subtype specific RT-PCR assays. 117 of these were tested positive for all three (Ct-values from 15.1 to 36.8). No oseltamivir resistance was detected. CONCLUSIONS: We present a sensitive and specific approach for detection of pandemic influenza A/H1N1 2009 and a rapid RT-PCR assay detecting a primary oseltamivir resistance mutation which can be incorporated easily into clinical virology algorithms.


Subject(s)
Disease Outbreaks , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/epidemiology , Influenza, Human/virology , Neuraminidase/genetics , Oseltamivir/pharmacology , Reverse Transcriptase Polymerase Chain Reaction/methods , Algorithms , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Drug Resistance, Viral , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Humans , Influenza A Virus, H1N1 Subtype/drug effects , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/drug therapy , Linear Models , Oseltamivir/therapeutic use , Point Mutation , Reproducibility of Results , Sensitivity and Specificity , Viral Proteins/genetics
17.
J Craniofac Surg ; 20(6): 2241-3, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19934681

ABSTRACT

Palmoplantar keratodermas may present to the clinician with an extremely broad series of clinical findings. Management has also taken on a wide variety of medical and surgical modalities. The literature seems to provide evidence that optimum management consists of surgical excision with skin grafting. It is believed that this will eliminate all of the underlying tissue and associated skin appendages, which are believed to be the source of this abnormal skin entity. We present a case of a patient in which tangential excision with delayed split-thickness skin grafting was performed after initial application of an acellular dermal matrix (Integra). Unfortunately, there was nearly immediate recurrence of this disease, and we, therefore, suggest a more aggressive approach to the initial excision.


Subject(s)
Foot/surgery , Hand/surgery , Keratoderma, Palmoplantar/surgery , Skin Transplantation/methods , Child, Preschool , Chondroitin Sulfates , Collagen , Female , Graft Rejection , Humans , Recurrence , Skin, Artificial
18.
Oecologia ; 161(3): 449-59, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19585154

ABSTRACT

Evaluations of plant water use in ecosystems around the world reveal a shared capacity by many different species to absorb rain, dew, or fog water directly into their leaves or plant crowns. This mode of water uptake provides an important water subsidy that relieves foliar water stress. Our study provides the first comparative evaluation of foliar uptake capacity among the dominant plant taxa from the coast redwood ecosystem of California where crown-wetting events by summertime fog frequently occur during an otherwise drought-prone season. Previous research demonstrated that the dominant overstory tree species, Sequoia sempervirens, takes up fog water by both its roots (via drip from the crown to the soil) and directly through its leaf surfaces. The present study adds to these early findings and shows that 80% of the dominant species from the redwood forest exhibit this foliar uptake water acquisition strategy. The plants studied include canopy trees, understory ferns, and shrubs. Our results also show that foliar uptake provides direct hydration to leaves, increasing leaf water content by 2-11%. In addition, 60% of redwood forest species investigated demonstrate nocturnal stomatal conductance to water vapor. Such findings indicate that even species unable to absorb water directly into their foliage may still receive indirect benefits from nocturnal leaf wetting through suppressed transpiration. For these species, leaf-wetting events enhance the efficacy of nighttime re-equilibration with available soil water and therefore also increase pre-dawn leaf water potentials.


Subject(s)
Ecosystem , Plant Leaves/physiology , Sequoia/physiology , Trees/physiology , Water/physiology , Absorption , California
19.
J Clin Virol ; 30(2): 165-74, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15125873

ABSTRACT

BACKGROUND: A multiplex reverse transcription (RT) polymerase chain reaction combined with a microwell hybridization assay (m-RT-PCR-ELISA) was previously developed to detect nine different microorganisms: enterovirus (EV), influenza virus type A (IVA) and type B (IVB), respiratory syncytial virus (RSV), parainfluenzavirus type 1 (PIV1) and type 3 (PIV3), adenovirus (AV), Mycoplasma pneumoniae (Mpn), Chlamydia pneumoniae (Cpn) in a single test. These organisms do not usually colonize the respiratory tract of humans, but, if present, it may be assumed they are involved in respiratory disease. OBJECTIVES AND STUDY DESIGN: The m-RT-PCR-ELISA was tested on (i) culture supernatants of unknown contents, (ii) by determining the analytical sensitivity of 10-fold serial dilutions of culture supernatants and (iii) by determining clinical sensitivity in a retrospective study on 411 clinical specimens. The specimens were re-tested in parallel by m-RT-PCR-ELISA versus the gold standard culture and immunfluorescence, and versus individual RT-PCR. RESULTS: (i) The 9-valent m-RT-PCR-ELISA shows 83% to 100% concordant results on 103 culture supernatants containing different organisms. (ii) The analytical sensitivity was as follows: higher sensitivity of the 9-valent m-RT-PCR-ELISA in comparison to culture in the cases of PIV3, IVA and IVB (factor 10) and AV and EV (factor 100), and lower sensitivity in case of RSV and PIV1 (factor 10). (iii) The agreement with the gold standard in the kappa statistic was excellent for RSV (kappa = 0.937), IVA (kappa = 0.940), very good for PIV1 (kappa = 0.914), IVB (kappa = 0.907) and satisfactory for PIV3 (kappa = 0.410). For AV, EV and Mpn the m-RT-PCR-ELISA preliminary could be qualified as very good, based on the data derived on culture supernatants. Information about the validity for Cpn is limited. CONCLUSION: The m-RT-PCR-ELISA is a feasible, sensitive and specific method for detection of a broad spectrum of organisms. It is suitable for individual as well as epidemiological diagnosis.


Subject(s)
Respiratory Tract Infections/virology , Reverse Transcriptase Polymerase Chain Reaction/methods , Adenoviridae/genetics , Adenoviridae/isolation & purification , DNA, Viral/genetics , DNA, Viral/isolation & purification , Enterovirus/genetics , Enterovirus/isolation & purification , Enzyme-Linked Immunosorbent Assay/methods , Humans , Influenza A virus/genetics , Influenza A virus/isolation & purification , Influenza B virus/genetics , Influenza B virus/isolation & purification , Observer Variation , Reproducibility of Results , Respiratory Syncytial Viruses/genetics , Respiratory Syncytial Viruses/isolation & purification , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/microbiology , Respirovirus/genetics , Respirovirus/isolation & purification , Sensitivity and Specificity
20.
Can J Microbiol ; 47(7): 680-4, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11547890

ABSTRACT

An Escherichia coli K-12 biofilm was grown at a dilution rate of 0.028 h(-1) for 48 h in a glucose-limited chemostat coupled to a modified Robbins' device to determine its susceptibility to infection by bacteriophage T4. Bacteriophage T4 at a multiplicity of infection (MOI) of 10 caused a log reduction in biofilm density (expressed as colony forming units (CFU) per cm2) at 90 min postinfection. After 6 h, a net decrease and equilibrium in viral titer was seen. When biofilms were exposed to T4 phage at a MOI of 100, viral titer doubled after 90 min. After 6 h, viral titers (expressed as plaque forming units (PFU) per cm2) stabilized at levels approximately one order of magnitude higher than seen at a MOI of 10. Scanning confocal laser microscopy images also indicated disruption of biofilm morphology following T4 infection with the effects being more pronounced at a MOI of 100 than at a MOI of 10. These results imply that biofilms under carbon limitation can act as natural reservoirs for bacteriophage and that bacteriophage can have some influence on biofilm morphology.


Subject(s)
Bacteriophage T4/growth & development , Bacteriophage T4/pathogenicity , Biofilms/growth & development , Escherichia coli/growth & development , Glucose/metabolism , Colony Count, Microbial , Culture Media , Escherichia coli/virology
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