Eye positions during ocular surgery.
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Anesthesia, General↗
Biomedical subjects
A Singh
Publications and source records attributed to A Singh.
Is there objective evidence that septal surgery improves nasal airflow?
OBJECTIVE: To identify any prospective, controlled trials providing objective evidence of a reduction in nasal airway resistance following nasal septal surgery, and to undertake a meta-analysis of available data. METHODS: A systematic review with meta-analysis of data was undertaken. A systematic review of the literature using a defined search strategy was conducted to identify papers that used objective methods of airway assessment to evaluate the benefit of septal surgery. Accepted techniques for objective airway assessment included acoustic rhinometry, active anterior rhinomanometry and peak nasal inspiratory airflow. Papers were included based on pre-defined criteria, which included standardization of techniques as outlined in the guidelines of the 1984 committee report on the standardization of rhinomanometry. RESULTS: We identified 942 articles, of which 13 were prospective studies evaluating the objective benefit of nasal septal surgery. Only three of these studies conformed to the inclusion criteria. A meta-analysis on these papers was performed using the Mantel-Haenszel method, and this demonstrated an overall reduction in nasal airway resistance following septal surgery for nasal obstruction (p=0.018). CONCLUSIONS: The majority of studies evaluating the objective benefit of septal surgery did not conform to the recommendations of the committee report on the standardization of rhinomanometry. Only three prospective controlled trials, with pooled data from 141 cases, were identified for meta-analysis. The conclusions that can be drawn concerning objective improvement in airway function following nasal septal surgery are therefore limited. More long-term studies, adhering to standardized techniques, are needed to provide more convincing data.
Airway Resistance↗
Does sodium hyaluronate- and carboxymethylcellulose-based bioresorbable membrane (Seprafilm) decrease operative time for loop ileostomy closure?
BACKGROUND: Adhesions can result in serious clinical complications and make ileostomy closure, which is relatively simple procedure into a complicated and prolonged one. The use of sodium hyaluronate and carboxymethyl cellulose membrane (Seprafilm) was proven to significantly reduce the postoperative adhesions at the site of application. The aim of this study was to assess the incidence and severity of adhesions around a loop ileostomy and to analyze the length of time and morbidity for mobilization at the time of ileostomy closure with and without the use of Seprafilm. METHODS: Twenty-nine surgeons from 15 institutions participated in this multicenter prospective randomized study. 191 patients with loop ileostomy construction were randomly assigned to either receive Seprafilm under the midline incision and around the stoma (Group I), only under the midline incision (Group II), or not to receive Seprafilm (Group III). At ileostomy closure, adhesions were quantified and graded; operative morbidity was also measured. RESULTS: All 3 groups were comparable relative to gender, mean age and number of patients with prior operations (26, 25 and 19, respectively). Group II patients were significantly more likely to have pre-existing adhesions than Group III patients (30.6% vs. 14.1%, p = 0.025). At stoma mobilization, significantly more patients in Group III than in Group I had adhesions around the stoma (95.2% vs. 82.3%, p = 0.021). Mean operative times were 27, 25, and 28 minutes, respectively (p = 0.38), with significant differences among sites. There was no significant difference in the number of patients needing myotomy or enterotomy (29, 27 and 24 patients, respectively), nor in the number of postoperative complications (7, 9 and 7 patients, respectively). CONCLUSIONS: When consistently applied, Seprafilm significantly decreased adhesion formation around the stoma but not operative times without any increase in the need for myotomy or enterotomy. These findings were not seen in the overall study population possibly due to the large number of surgeons using a variety of application techniques.
Adjuvants, Immunologic↗
IL-6 protects enterocytes from hypoxia-induced apoptosis by induction of bcl-2 mRNA and reduction of fas mRNA.
Interleukin-6 (IL-6) has been shown to rescue enterocytes from hypoxia-induced apoptosis when given orally following hemorrhagic shock. In vitro models using an intestinal epithelial cell line (IEC-6) cultured with lipopolysaccharide (LPS) under low O2 conditions, to mimic intestinal conditions, show that these cells also undergo apoptosis, which can be reduced by subsequent culture with IL-6. To examine further the mechanisms of rescue, we cultured normal rat intestinal epithelial cells (IEC-6) under both normoxic and hypoxic conditions and analyzed their responses to LPS and IL-6. We showed that IEC-6 expressed IL-6 receptor on its surface. Further, IEC-6 cells could be rescued from hypoxia-induced apoptosis by co-culture with IL-6. RNase protection assay (RPA) examination revealed that under hypoxic conditions, IEC-6 cells that were resistant to apoptosis showed reduced fas expression and increased bcl-2 expression after co-culture with LPS+IL-6.
Animals↗
Voice-related Quality of Life in laryngectomees: assessment using the VHI and V-RQOL symptom scales.
The primary purpose of this study was to investigate the effect of the voice impairment across the physical, emotional, and functional domains in patients using valved speech following total laryngectomy with the help of two symptom specific scales. The study design used was a cross-sectional cohort. The setting was the Head and Neck Oncology Unit of a tertiary referral centre. Subjects were 54 patients who had undergone total laryngectomy. Two voice-specific questionnaires, the Voice-Related Quality of Life (V-RQOL-short form) Measure, and the Voice Handicap Index (VHI-long form) were used. The main outcome measure was patient perception of the voice following total laryngectomy in response to specific questions correlated with sociodemographic/treatment factors. Responses were received from 40 males and 14 females (response rate of 85.7%) with a median age of 63.4 years (range: 37-84). The V-RQOL overall analysis showed that 3 patients (5.6%) scored "excellent," 29 patients (53.7%) "fair to good," 14 patients (25.9%) "poor to fair," and 8 patients (14.8%) "poor." Analysis of the VHI revealed that 20 patients (37.0%) had a minimal handicap, 20 patients (37.0%) a moderate handicap, and 14 patients (25.9%) had a serious voice handicap. The individual domain or subscale scores for the VHI revealed a mean (SD) functional score of 15.8 (7.7), a physical score of 13.6 (7.2), and finally an emotional score of 11.6 (8.9). Functional aspects of the voice were significantly affected by age, radiotherapy, and chemotherapy (Spearman rho, P=0.01; Mann-Whitney, P=0.04 and P=0.01). The physical aspects of the voice were significantly affected by age and chemotherapy (Spearman rho, P=0.004; Mann-Whitney, P=0.04). Only age significantly affected the emotional aspects of the voice (Spearman rho, P=0.002). We found a strong correlation (Spearman rho, P<0.001) between the V-RQOL and VHI questionnaires. Our study revealed that the V-RQOL and VHI scores in our series of patients following voice restoration in laryngectomees were consistent with that reported in the literature. Only age, radiation, and chemotherapy were seen to influence the voice handicap scores. In addition, both symptom scales had good correlation between them and either one could be used with reliability in laryngectomees with a few modifications.
Adult↗
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.
Aged↗
Solitary nasal neurofibroma presenting as compressive optic neuropathy.
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Adult↗
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.
Animals↗
Gingival epithelial cells heterozygous for Toll-like receptor 4 polymorphisms Asp299Gly and Thr399ile are hypo-responsive to Porphyromonas gingivalis.
The Toll-like receptor (TLR)4 is the major sensor for bacterial lipopolysaccharide and its two common co-segregating polymorphisms, Asp299Gly and Thr399Ile, which occur at a frequency of between 6 and 10%, have been associated with infectious diseases, LPS hypo-responsiveness and cardiovascular disease. Porphyromonas gingivalis is a Gram-negative bacterium implicated in chronic periodontitis and is a known TLR4 and TLR2 agonist. We obtained two gingival epithelial cell primary cultures from subjects heterozygous for the TLR4 polymorphism Asp299Gly and compared response characteristics with similar cells from patients (four) with the wild-type TLR4 genes. Cytokine responses and transcriptome profiles of gingival epithelial cell primary culture cells to TNFalpha challenge were similar for all primary epithelial cell cultures. P. gingivalis challenge, however, gave markedly different responses for Asp299Gly heterozygous and wild-type epithelial cell cultures. The epithelial cells heterozygous for the TLR4 polymorphism Asp299Gly were functionally hypo-responsive, evidenced by differences in BD-2 mRNA expression, mRNA response profile by microarray analysis and by pro-inflammatory and chemokine cytokines at the protein and mRNA level. These findings emphasize variance in human epithelial cell TLRs, linked with Asp299Gly carriage, which results in a hypo-responsive epithelial cell phenotype less susceptible to Gram-negative diseases and associated systemic conditions.
Amino Acid Substitution↗
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.
Biomarkers↗
Can objective parameters derived from videofluoroscopic assessment of post-laryngectomy valved speech replace current subjective measures? An e-tool-based analysis.
OBJECTIVES: The primary purpose of this study was to assess the pharyngoesophageal segment in total laryngectomy patients using a videofluoroscopy e-tool. STUDY DESIGN: Cross-sectional study. SETTING: Head and Neck Oncology Unit, Tertiary Referral Centre. PATIENTS: Forty-two patients following total laryngectomy. INTERVENTION: Videofluoroscopy using an e-tool (JRuler). MAIN OUTCOME MEASURES: Subjective and objective videofluoroscopy parameters correlated with the GRBAS scale and treatment variables. RESULTS: Of 32 men and 10 women, mean age 63.5 years (10.8) the majority (64.3%) had a reasonable voice (good = 11 and poor = 4 patients). Comparing subjective and objective parameters, significant correlations were only seen with a smaller minimal neoglottic distance at phonation with no regurgitation of barium at phonation (P = 0.05) and a type 1 shape of neoglottis at phonation (P = 0.02). There were also significant correlations between smaller maximum sub-neoglottic distance at phonation and type 1 shape of neoglottis (P = 0.02), smaller maximum sub-neoglottic distance at rest and absence of stasis of barium at phonation (P = 0.05) and the length of neoglottis at phonation and type 1 shape of neoglottis (P = 0.01). For perceptual evaluation, significant correlation was seen only between G1 voice and a smaller minimal neoglottic distance at phonation (P = 0.03) amongst the subjective and objective parameters. There were no correlations between visual parameters and the clinical parameters. CONCLUSIONS: Our observations suggest that this interesting concept has limitations. While objective and quantifiable data can be obtained using videofluoroscopy in laryngectomees, only a few correlate with each other and with voice quality.
Cross-Sectional Studies↗
An anatomical comparison of Blair and facelift incisions for parotid surgery.
BACKGROUND: The rhytidectomy approach for parotidectomy allows the incision to be hidden, and post-operative scarring minimised. Furthermore, separate elevation of the Superficial Musculo-Aponeurotic System (SMAS) reduces the incidence of Frey's syndrome, and provides vascularized soft tissue for contour reconstruction. The technique has gained popularity particularly with plastic surgeons, but concerns persist that with this approach, particularly with lesions located anteriorly, access to the gland may be inadequate, and facial nerve identification may be compromised. MATERIALS AND METHODS: We undertook an anatomical study to quantitatively compare the surgical access achieved using the facelift approach with the conventional Blair incision, by comparing the distances between the parotid edge and the retracted flaps. RESULTS: Despite reduced tissue elasticity due to formaldehyde fixation, it proved possible to demonstrate all regions of the parotid gland to the operating surgeon with either approach. There were no significant differences in the distance between the parotid edge and the retracted skin flaps (P > 0.1; paired t-test). CONCLUSIONS: The facelift approach provides at least equal access to all regions of the parotid gland when compared to a Blair's incision. It is a superior approach aesthetically and its more widespread use in parotid surgery is advocated.
Adenoma, Pleomorphic↗
The outcome of surgery in fulminant Clostridium difficile colitis.
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Clostridioides difficile↗
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.
Adolescent↗
Validation of a voice prosthesis questionnaire to assess valved speech and its related issues in patients following total laryngectomy.
OBJECTIVES: To establish the reliability and validity of a new self-administered questionnaire to assess valved speech and its related issues in patients who have undergone a total laryngectomy operation. DESIGN: Cross-sectional psychometric validation study. SETTING: Tertiary cancer care centre. PATIENTS: We identified sixty-one total laryngectomy patients with no sign of recurrent disease and using voice prosthesis from the speech and language therapy database of the Royal Marsden Hospital. The patients were assessed using a postal self-administered voice prosthesis questionnaire concerning the voice valve and it's related issues. Patients were also asked to complete the University of Michigan voice related quality of life and University of Washington head and neck quality of life (version 4) questionnaires. MAIN OUTCOME MEASURES: Test-retest and internal consistency reliability; content; criterion and construct validity. RESULTS: We received completed questionnaires from fifty-one of the sixty-one total laryngectomy patients identified for the study providing a response rate of 84%. The median age of the group was 65 years (range: 40-85) with thirty-seven males and fourteen females. The internal consistency reliability using the Cronbach's alpha coefficient was 0.87 (range: 0.85 to 0.89). Test-retest reliability showed that more than 75% of patients had a score on re-test that was within 1 point of their original score. Content validity was ensured during the design process. The median Spearman correlation coefficient was 0.25 for convergent construct validity with the University of Washington head and neck quality of life questionnaire and 0.64 for criterion validity on comparison with the University of Michigan voice related quality of life scale. CONCLUSIONS: The voice prosthesis questionnaire is the first validated and reliable self-administered questionnaire designed specifically for evaluating valved speech and its related issues in patients who have undergone total laryngectomy. The voice prosthesis questionnaire has significant utility for audit, outcomes research and monitoring in this unique group of patients.
Adult↗
A "respiratory" cause of abdominal pain.
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Abdominal Pain↗
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.
Bicuspid↗