Conditionally immortalized human glomerular endothelial cells expressing fenestrations in response to VEGF

Glomerular endothelial cells (GEnC) are specialized cells with important roles in physiological filtration and glomerular disease. Despite their unique features, GEnC have been little studied because of difficulty in maintaining them in cell culture. We have addressed this problem by generation of conditionally immortalized (ci) human GEnC using technology with which we have previously produced ci podocytes. Primary culture GEnC were transduced with temperature-sensitive simian virus 40 large tumour antigen and telomerase using retroviral vectors. Cells were selected, cloned, and then characterized by light and electron microscopy (EM), response to vascular endothelial growth factor (VEGF), and tumour necrosis factor (TNF)alpha, expression of endothelial markers by focused gene array, immunofluorescence and Western blotting, and formation and behaviour of monolayers. CiGEnC proliferated at the permissive temperature (33 degrees C) and became growth arrested at the non-permissive temperature (37 degrees C). CiGEnC retained morphological features of early-passage primary culture GEnC up to at least p41, confirming successful immortalization. EM demonstrated fenestrations, increased in number by VEGF. mRNA analysis confirmed expression of the endothelial markers platelet endothelial cell adhesion molecule 1, intercellular adhesion molecule 2, VEGF receptor 2, and von Willebrand factor, validated by immunofluorescence and Western blotting. CiGEnC also expressed Tie2, and TNFalpha upregulated E-selectin. CiGEnC formed monolayers with barrier properties responsive to cyclic adenosine 3',5' monophosphate (cAMP) and thrombin. CiGEnC retain the markers and behaviour of primary culture GEnC. They express fenestrations which are upregulated in response to VEGF. These cells are a unique resource for further study of GEnC and their roles in glomerular filtration, glomerular disease, and response to glomerular injury.

Anti-erythrocyte natural antibody activity in the unconventional ‘heavy chain’ immunoglobulins of Indian desert camel (Camelus dromedarius)

Members of the family Camelidae contain unconventional 'heavy chain' antibodies (HCAbs) that are devoid of light chains (LCs) in their structure and occur under physiological conditions. The spectrum of antigenic specificities in HCAbs and hence their biological significance is not known at present. Recent studies have however indicated that they contribute significantly towards the immunoglobulin (Ig) receptor diversity. The present study was planned to investigate the natural antibody (NAb) activity in camel HCAbs as further indication of the wide spectrum of their antigenic specificities. Detection of NAbs in the sera and isolated HCAbs of Indian Thar desert camels was undertaken against erythrocyte antigens (E-Ags) from eleven animal species including nine mammals, chicken and frog by using direct haemagglutination (HA) and indirect Coombs' test. HCAbs were found to behave as 'incomplete antibodies' and agglutinated erythrocytes of different animal species in indirect Coombs' test using rabbit anti-camel IgG3 (HCAbs) antiserum. Variations were noticed in the Coombs' titres against erythrocytes from different species. HCAbs also reacted against E-Ags in immunoblots. These findings provide further evidence that camelid HCAbs are produced against diverse antigens (Ags) under natural conditions, thereby contributing to camelid Ig receptor diversity.

Comparison of Coapsys annuloplasty and internal reduction mitral annuloplasty in the randomized treatment of functional ischemic mitral regurgitation: impact on the left ventricle

BACKGROUND

Functional mitral regurgitation is associated with both annular and ventricular distortion. Aggressive reduction annuloplasty for functional mitral regurgitation acts primarily at the annulus, with variable impact on the left ventricle. The Coapsys device externally reshapes the left ventricle to correct functional mitral regurgitation. Left ventricular reshaping was analyzed in a randomized study.

METHODS

The RESTOR-MV study randomizes patients with coronary artery disease and functional mitral regurgitation to either reduction annuloplasty and coronary artery bypass grafting (the RA group) or Coapsys annuloplasty and bypass grafting (the CO group). The Coapsys device consists of epicardial pads connected by a cord. It was placed without cardiopulmonary bypass under echocardiographic guidance and sized to reduce annular dimension and improve leaflet coaptation. Internal reduction annuloplasty was performed by device placement. Intraoperative transesophageal echocardiograms were analyzed in 7 patients having reduction annuloplasty and 7 having Coapsys annuloplasty.

RESULTS

Baseline mitral regurgitation (0-4 scale) was similar for the RA (3.0 +/- 0.6) and the CO groups (3.0 +/- 0.6). Intraoperative mitral regurgitation was reduced from 2.86 +/- 0.7 to 0.5 +/- 0.7 (P < .01 pre vs post) for the RA group and from 2.64 +/- 0.9 to 05 +/- 0.7 (P < .01 pre vs post) for the CO group. Annular anteroposterior diameter was reduced with both techniques: RA, 3.45 +/- 0.39 to 2.34 +/- 0.37 cm (P < .01 pre vs post); CO, 3.40 +/- 0.27 to 2.85 +/- 0.34 cm (P < .05 pre vs post). Long-axis dimensions were unchanged with both techniques. Short-axis dimensions measured at three levels were significantly reduced only in the CO patients: basal diameter 4.77 +/- 0.58 to 3.58 +/- 0.38 cm (P < .01 pre vs post); mid diameter 4.88 +/- 0.55 to 3.57 +/- 0.43 cm (P < .01 pre vs post); and apical diameter 4.39 +/- 0.46 to 3.38 +/- 0.34 cm (P < .01 pre vs post).

CONCLUSIONS

Coapsys and reduction annuloplasty techniques both acutely reduce functional mitral regurgitation and annular dimension. The Coapsys device provided significantly greater left ventricular reshaping than did reduction annuloplasty. Further evaluation will assess the long-term valvular function and ventricular geometric stability associated with both techniques.

Asymptomatic oropharyngeal lipoma complicating intubation

Oropharyngeal lipomas are rare tumours. We present the case of a young man with an asymptomatic lipoma almost completely occluding his supraglottic airway, found on magnetic resonance imaging (MRI) for a separate oral cavity lesion. Pre-operative anaesthetic assessment was undertaken because of the risk of airway obstruction at induction of general anaesthesia. We discuss the awake fibre-optic technique used for induction, as well as the treatment and follow-up of these tumours. This case highlights the need for formal anaesthetic assessment, in such cases, to avoid total airway obstruction at induction of general anaesthesia. It also emphasizes the extent of supraglottic obstruction that can be present without giving rise to any symptoms.

Microleakage of restorative materials: an in vitro study

The present study was conducted with the aim of evaluating and comparing the microleakage of glass ionomer, composite resin and compomers. Class V cavities were made in thirty intact caries free premolars and restored with restorative materials to be tested respectively. The teeth were thermocycled and subjected to silver nitrate dye penetration. They were subsequently sectioned buccolingually. Microleakage was evaluated under a stereomicroscope and data subjected to statistical analysis. The study concluded that microleakage was evident in all restorative materials, with glass ionomer showing maximum leakage followed by composite resin. Compomer demonstrated the best results with minimum leakage.

Decreased risk of renal allograft thrombosis associated with interleukin-2 receptor antagonists: a report of the NAPRTCS

Graft thrombosis is the most common cause of first year graft failure in pediatric renal transplantation. The North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) database was analyzed for cases of graft failure due to thrombosis among patients transplanted from 1998 to 2004. The impact of interleukin-2 (IL-2) receptor antagonists as induction therapy was determined. There were a total of 51 graft failures due to thrombosis among the 2750 reported renal transplants (1.85%) (95% CI (1.39%, 2.41%)). This represents the most common cause of graft loss during the first year post-transplant accounting for 35% of first year losses and 18% of all graft losses. The incidence of thrombosis among patients who received IL-2 receptor antibodies was 1.07% (12/1126) compared to 2.40% (39/1624) among patients who did not (OR 0.44, 95% CI 0.23, 0.84, p = 0.014). Use of IL-2 receptor blockade was the only significant prognostic factor in a multivariate model with previously identified risk factors. Analysis of NAPRTCS data found that the use of IL-2 receptor antibodies as induction therapy is associated with a significantly decreased risk of graft failure due to thrombosis. This provocative finding requires further investigation to determine whether thrombotic failure can be decreased by this therapeutic strategy.

Comparison of seven different scales used to quantify severity of cervical spondylotic myelopathy and post-operative improvement

Considerable uncertainty exists over the benefit that patients receive from surgical decompressive treatment for cervical spondylotic myelopathy (CSM). Such difficulties might be addressed by accurate quantification of CSM severity as part of a trial determining the outcome of surgery in different patient groups. This study compares the applicability of various existing quantitative severity scales to measurement of CSM severity and the effects on severity of surgical decompression. Scores on the following scales were determined on 100 patients with CSM preoperatively and then again six months following surgical decompression: Odom's Criteria, Nurick grade, Ranawat grade, Myelopathy Disability Index (MDI), Japanese Orthopaedic Association (JOA) Score, European Myelopathy Score (EMS) and Short Form-36 Health Survey (SF36). All the scales showed significant improvement following surgery. However, each had differing qualities of reliability, validity and responsiveness that made them more or less suitable. The MDI showed the greatest sensitivity between different severity levels, sensitivity to operative change and reliability. However, analysis of all the questionnaire scales into components that looked at different aspects of function revealed potential problems with redundancy and a lack of consistency. This prospective observational study provides a rational basis for determining the advantages and disadvantages of different existing scales in measurement of CSM severity and for making adaptations to develop a scale more specifically suited to a comprehensive surgical trial.

Use of quantitative assessment scales in cervical spondylotic myelopathy--survey of clinician's attitudes

BACKGROUND

There is considerable uncertainty regarding the selection criteria of patients and timing of surgery for cervical spondylotic myelopathy (CSM). Attempts have been made to quantify CSM severity using various assessment scales to provide an adjunct to clinical decision-making. The aim of the present study was to determine, by means of a 7-item questionnaire the attitudes of clinicians regarding the importance of quantitative assessment scales in the management of CSM, their actual use in clinical practice and how current scales fall short of the ideal.

FINDINGS

Clinical history, examination, radiological imaging and quantitative functional assessment were regarded by 117 clinicians as being almost equally important in the management of CSM. However, only 22 (19%) of clinicians admitted to using an assessment scale in clinical practice and 4 (3%) believed there was a 'gold-standard' assessment scale. These clinicians also considered 'ease of use' to be the most important attribute of an ideal assessment scale, followed by 'reproducibility', 'sensitivity to change' and 'validity'.

CONCLUSIONS

The discrepancy between the importance attached to quantitative measurement and its actual use suggests that current scales are under-utilised or unsuitable for clinical practice. A new easy-to use scale may be required that better reflects clinical requirements.

Pulsatile tinnitus

Pulsatile tinnitus is an uncommon otological symptom. Objective pulsatile tinnitus has numerous causes, including benign intracranial hypertension, glomus tumours and atherosclerotic carotid artery disease. History and physical examination can give important information as to the underlying diagnosis. Radiographic evaluation is essential in all patients with pulsatile tinnitus. Many patients have a treatable underlying aetiology. Early diagnosis and appropriate intervention may save patients from unnecessary morbidity.