Evaluation of a commercial assay for the detection of mumps specific IgM antibodies in oral fluid and serum specimens.

BACKGROUND: An IgM antibody capture radioimmunoassay (MACRIA) has been used in the UK Reference Laboratory for the detection of mumps specific IgM antibodies in oral fluid and serum samples. The method has proved both sensitive and specific and has been used for the surveillance of mumps since 1994. The use of radioactive labels has restricted the use of MACRIA to specialised laboratories and alternative, non-isotopic, sensitive assays capable of detecting the low levels of specific antibodies in oral fluid have not been available. Recently, a novel mumps specific IgM capture enzyme immunoassay (MACEIA) utilising recombinant mumps nucleoprotein (rMuVN) and monoclonal antibodies to the nucleoprotein, produced by Microimmune Limited, has been developed for use with both serum and oral fluid samples. OBJECTIVES: In this study, we have evaluated the performance of the Microimmune MACEIA for both serum and oral fluid against specimens tested by MACRIA. STUDY DESIGN: The panel consisted of matched serum and oral fluid specimens from 137 cases of suspected mumps received in the Virus Reference Department for routine investigation from March 2003 to October 2004. RESULTS: The sensitivity, specificity, positive and negative predictive value of the Microimmune MACEIA on serum samples compared to MACRIA were 98.8%, 100.0%, 100.0% and 98.5%, respectively. The sensitivity, specificity, positive and negative predictive value of the Microimmune MACEIA on oral fluid samples compared to Microimmune MACEIA and MACRIA consensus results on the paired serum samples were 90.3%, 97.6%, 98.3% and 87.1%, respectively. CONCLUSIONS: The Microimmune MACEIA was found to be a rapid, sensitive and specific alternative to MACRIA for the detection of mumps specific IgM in sera and oral fluids.     

High level expression of recombinant mumps nucleoprotein in Saccharomyces cerevisiae and its evaluation in mumps IgM serology.

To develop improved reagents for mumps serology a high-level yeast expression system was employed to produce recombinant mumps nucleoprotein (rNP). The rNP was purified by CsCl gradient centrifugation and yielded approximately 15 mg/l of yeast culture. Electron microscopy of the rNP revealed characteristic herring-bone structures. The electrophoretic mobility of rNP in yeast cells was similar to native NP in SDS-PAGE. Monoclonal antibodies to rNP reacted with native mumps virus nucleoprotein by immunofluorescence assay. A monoclonal antibody to native mumps virus NP reacted with rNP by Western blot assay. The rNP was investigated as antigen in an IgM capture enzyme immunoassay (EIA) using a horseradish peroxidase conjugate of monoclonal antibody to the rNP. Eighteen sera previously found to be positive by IgM capture radioimmunoassay (MACRIA) and 30 sera that were mumps IgM negative by MACRIA were tested by mumps IgM capture EIA. The results for the two test were concordant. In addition, 26 rheumatoid factor positive sera and 35 sera that were IgM positive for measles, rubella or parvovirus B19 were tested. Fifty-nine sera were negative by mumps IgM capture EIA but two sera collected from two infants 3 and 6 weeks after mumps, measles and rubella vaccination were positive. Mumps MACRIA confirmed these results. Compared to MACRIA the overall sensitivity was 100% (20/20) and specificity was 96.8% (30/31). The yeast expressed rNP was highly immunogenic and suitable for use in IgM capture EIA for the diagnosis of mumps.     

Burn scar contractures of the feet: efficacy of bilateral simultaneous surgical correction

Children who sustain large total body surface area (TBSA) burns with involvement of the lower extremities frequently sustain injuries to the dorsum of the feet. Burn scar contractures of the feet can develop as a sequela of the burn injury. Such contractures frequently require surgical correction. Many surgeons proceed with staged unilateral corrections when both feet are equally in need of operative intervention. The purpose of the study is to determine if the morbidity for correction of bilateral dorsal foot contractures is different from that for the correction of unilateral dorsal foot contractures.

A retrospective review from January 1994 to July 1999 was undertaken. Forty-five patients with photographic record of burn scar contracture of the feet were identified. Twenty-five patients underwent staged unilateral surgical correction and twenty patients underwent simultaneous bilateral correction of the feet. All patients underwent surgical correction with split thickness skin grafts (STSG). No statistical difference was found in terms of mortality, development of contracture, or number of reconstructive procedures. However, the length of stay revealed the efficacy of the bilateral simultaneous release of the dorsal feet.     

Why pictures look right when viewed from the wrong place

A picture viewed from its center of projection generates the same retinal image as the original scene, so the viewer perceives the scene correctly. When a picture is viewed from other locations, the retinal image specifies a different scene, but we normally do not notice the changes. We investigated the mechanism underlying this perceptual invariance by studying the perceived shapes of pictured objects viewed from various locations. We also manipulated information about the orientation of the picture surface. When binocular information for surface orientation was available, perceived shape was nearly invariant across a wide range of viewing angles. By varying the projection angle and the position of a stimulus in the picture, we found that invariance is achieved through an estimate of local surface orientation, not from geometric information in the picture. We present a model that explains invariance and other phenomena (such as perceived distortions in wide-angle pictures).     

Intradialytic dobutamine therapy in maintenance hemodialysis patients with persistent hypotension.

Intradialysis hypotension is a common problem, especially in patients with poor left-ventricular function. We studied 6 patients who were on maintenance hemodialysis with left-ventricular ejection fraction of <40%, whose dialysis sessions were often complicated with severe hypotension (systolic blood pressure <90 mm Hg). Dobutamine infusion during dialysis significantly reduced the number of hypotensive episodes, increased left-ventricular ejection fraction, and decreased the number of emergency admissions to the hospital.     

Monoclonal antibodies to the haemagglutinin HA1 subunit of the pandemic influenza A/H1N1 2009 virus and potential application to serodiagnosis

In order to provide specific serological reagents for pandemic influenza A/H1N1 2009 virus, monoclonal antibodies (Mabs) to recombinant haemagglutinin component HA1 (rHA1) were generated after fusing spleen cells from a mouse immunized with rHA1 protein derived from influenza strain A/California/06/09 H1N1 with a mouse myeloma cell line. Five hybridoma clones secreting Mabs specific for the rHA1 protein derived from pandemic influenza A/H1N1 2009 and not for rHA1 from seasonal H1N1 influenza strains A/Brisbane/59/07 and A/Solomon Islands/03/06 were identified by EIA. Mabs 7H4, 9A4, and 9E12 were reactive in Western blots with full length rHA and/or rHA1 subunit derived from A/California/06/09 strain. Only Mab 1F5 inhibited haemagglutination of turkey red blood cells with recombinant NIBRG‐121 virus derived from A/California/07/09, but did not react in Western blots. Immunostaining of MDCK cells infected with NIBRG‐121 was localized to the membrane/cytoplasm for four of the reactive Mabs. The differing reactivity of the Mabs in Western blots, immunostaining, EIA, and haemagglutination inhibition assay suggest that at least four of the five Mabs recognize different epitopes on HA1 of the pandemic influenza A/H1N1 2009 virus. Ferret antisera to pandemic influenza A/H1N1 2009 (A/England/195/09 and A/California/07/09 strains) and sera from human subjects vaccinated with Influenza A (H1N1) 2009 Monovalent Vaccine (CELTURA®, Novartis Vaccines, Germany), inhibit binding of 1F5‐HRP to biotinylated rHA1 derived from A/California/06/09 in a competitive EIA, suggesting that the epitope recognized by this Mab also evokes an antibody response in infected ferrets and vaccinated humans. J. Med. Virol. 83:559–567, 2011. © 2011 Wiley‐Liss, Inc.     

Single-stage functional reconstruction of the post-burn lower lip

Burn scar contracture of the lower face and neck is one of the most difficult subjects to solve because it produces problems with function and appearance. The lip is a part of the face that is frequently affected by burn injury. Lower lip deformity can be due to an extrinsic or intrinsic cause. Post-burn sequelae in this area results in cosmetic disfigurement and psychological trauma to patients as it is often associated with ectropion of the lower lip, severe microstomia leading to poor oral access for intubation, drooling, difficulty in eating, speaking and oral hygiene. The aim is to describe a single-stage correction to address all of these problems for a successful outcome. The technique was applied to 30 post-burn scar contractures of the lower lip. We classified the deformities of the lower lip and based on this classification the surgical procedure was executed to obtain functional improvement. At 2 months post-surgery the patient is able to demonstrate speech clarity with full functional oral range of movement. Neck release combined with vermillionectomy and comissuroplasty of the lip is a rational approach for preserving the function. A good planning of reconstructive procedures, facilitate patient recovery and optimize functional and aesthetic outcomes.     

Evaluation of Subgingival Microflora in All Ceramic Restorations with Subgingival Heavy Chamfer Finish Lines

Microbial colonization in the gingival sulci of abutment teeth receiving all ceramic retainers with subgingival margins need to be studied to assess the prognosis of periodontal health, which determine the eventual success of fixed partial dentures. This prospective observational study was done to evaluate the quantitative alteration in the microbial flora in the gingival sulci of abutment teeth adjacent to the edentulous space prior and after receiving all ceramic retainers over varying time intervals of 1 week, 1 month and 2 months respectively. Twenty, healthy partially edentulous patients, aged 20–50 years with single missing central incisor were selected for this prospective observational study and their microbial samples were collected from the gingival sulci of abutments adjacent to edentulous space with sterile paper points and cultured and the estimated values for microflora served as controls. The same abutments were prepared to receive all ceramic retainers with subgingival heavy chamfer marginal finish lines. The patients were recalled after 1 week, 1 month, 2 months intervals during which the collected subgingival microbial samples were cultured and the corresponding quantitative microbial alteration in the restored gingival sulci was recorded. The obtained data was statistically analysed using the student t test and repeated analysis of variance test. The results of the study inferred student t test expressed a statistically significant (p < 0.001) progressive increase in gingival sulcular microbial colonisation in the abutment teeth before [M = 2.52 ± SD 1.21(10⁶) CFU/ml] and after receiving all ceramic retainers over varying time intervals of 1 week [M = 3.25 ± SD 1.21(10⁶) CFU/ml], 1 month [M = 4.64 ± SD 1.13(10⁶) CFU/ml] and 2 months [M = 4.75 ± SD 1.16(10⁶) CFU/ml] respectively. The result of repeated analysis of variance test inferred that there was a statistically significant difference (p < 0.001) in the subgingival microfloral count between the pre operative and post operative samples at 1 week, 1 month and 2 months. Subgingivally placed all-ceramic retainers with heavy chamfer finish lines in the abutment teeth demonstrated a statistically significant increase in sulcular microbial colonization over varying time intervals of 1 week, 1 month and 2 months respectively and this may affect periodontal health of abutment teeth progressively.