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Biomedical subjects

A Vats

Publications and source records attributed to A Vats.

At least 19 recordsLinked to original sources

Information technology in ENT: are we ready to be 'Connected For Health'?

The NHS Connecting for Health agency continues to implement the national programme for information technology within the National Health Service (NHS). In preparation, NHS employees are being encouraged to develop their information technology skills via the European computer driving licence training course. A postal survey of British Association of Otorhinolaryngologists members was undertaken to evaluate their levels of information technology training, competency and knowledge. Three hundred and thirty-six surgeons responded. Most respondents had received no formal information technology training. Only 3.9 per cent had taken the European computer driving licence course. Most surgeons felt comfortable using word processing and presentation software but were less comfortable with other applications. Junior surgeons were more confident in all areas of information technology application than senior surgeons. Seventy-two per cent of surgeons wanted more information technology training. Most felt that such training should be routine at undergraduate and postgraduate level. With the national programme committed to improving information technology infrastructure within the NHS, more formal training should be provided to ensure a basic standard of information technology competency amongst ENT surgeons.

Adult↗

Laryngeal ultrasound to assess vocal fold paralysis in children.

The purpose of this study was to assess the practicality and validity of laryngeal ultrasound to establish vocal fold movement in children with suspected vocal fold palsy. Fifty-five consecutive patients (age range three days to 12 years) with suspected vocal fold palsy underwent both laryngoscopy and laryngeal ultrasound. Ultrasonographic findings correlated with endoscopic findings in 81.2 per cent of cases. This, however, rose to a concordance rate of 89.5 per cent in patients aged over 12 months. Laryngeal ultrasound is well-tolerated, safe and non-invasive and the authors feel that it is a useful adjunct to endoscopy in the diagnosis of vocal fold palsy.

Bronchoscopy↗

Scaffolds and biomaterials for tissue engineering: a review of clinical applications.

Tissue engineering is a multidisciplinary area of research aimed at regeneration of tissues and restoration of organ function. This is achieved through implantation of cells/tissues grown outside the body or by stimulating cells to grow into an implanted matrix. In this short review, we discuss the use of biomaterials, in the form of scaffolds, for tissue engineering and review clinical applications to otorhinolaryngology-head and neck surgery.

Biocompatible Materials↗

Stem cells: sources and applications.

Tissue engineering is a multidisciplinary area of research aimed at regeneration of tissues and restoration of function of organs through implantation of cells/tissues grown outside the body, or stimulating cells to grow into implanted matrix. In this short review, some of the most recent developments in the use of stem cells for tissue repair and regeneration will be discussed. There is no doubt that stem cells derived from adult and embryonic sources hold great therapeutic potential but it is clear that there is still much research required before their use is commonplace. There is much debate over adult versus embryonic stem cells and whether both are required. It is probably too early to disregard one or other of these cell sources. With regard to embryonic stem cells, the major concern relates to the ethics of their creation and the proposed practice of therapeutic cloning.

Animals↗

Gene expression: a review of clinical applications in otorhinolaryngology-head and neck surgery.

Tissue engineering is a multidisciplinary area of research aimed at regeneration of tissues and restoration of function of organs through implantation of cells/tissues grown outside the body or stimulating cells to grow into implanted matrix. In this short review, we aim to examine current techniques in gene expression analysis and their relevant clinical applications to the field of otorhinolaryngology-head and neck surgery.

Gene Expression↗

Familial nephrotic syndrome: clinical spectrum and linkage to chromosome 19q13.

BACKGROUND: Familial nephrotic syndrome (NS) has both autosomal dominant and recessive forms of inheritance. Recent studies in families with an autosomal dominant form of focal segmental glomerulosclerosis (FSGS) have been at odds concerning linkage to chromosome 19q13 (Mathis et al, Kidney Int 53:282-286, 1998; Winn et al, Kidney Int 55:1241-1246, 1999), suggesting genetic heterogeneity. This study examines the clinical features and confirms linkage to chromosome 19q13 in a family with autosomal dominant NS. METHODS: DNA samples were obtained from 16 of 17 family members. Genomic DNA was isolated, and polymerase chain reaction was performed for five markers spanning the area of interest on chromosome 19q13. Data were evaluated using two- and six-point linkage analysis. RESULTS: Clinical features included presentation of NS in childhood, steroid unresponsiveness, and slow progression to renal failure. Renal biopsy in affected family members showed lesions ranging from minimal change to mesangial proliferative glomerulonephritis to FSGS. Linkage was confirmed between the disease state and chromosome 19q13, with a maximum logarithm of odds (LOD) score of 2.41. Linkage was observed for a 7 cM region on chromosome 19q13, defined by markers D19S425 and D19S220. CONCLUSIONS: This study confirms the Mathis et al report of linkage to chromosome 19q13 in a family with autosomal dominant NS. However, there were notable differences in the presenting clinical and histopathologic features of our affected family members compared with those of Mathis et al. This suggests that the gene on chromosome 19q13 may be responsible for considerable phenotypic heterogeneity and variable expression in both clinical presentation and renal histopathology.

Adolescent↗

Henoch-Schönlein purpura and pulmonary hemorrhage: a report and literature review.

Pulmonary hemorrhage, a rare complication of Henoch-Schönlein purpura (HSP) reported primarily in adults and adolescents, is associated with significant mortality. Although it has been suggested that pulmonary hemorrhage also occurs in children with HSP, the few cases reported lack a clear differentiation from pauci-immune vasculitis. We report a prepubertal child with HSP, pulmonary hemorrhage, and immunofluorescence-documented IgA deposits on renal biopsy. Aggressive supportive management and steroid therapy led to successful recovery. A review of the current literature is presented. Because other conditions clinically mimic HSP, appropriate serological studies and a kidney biopsy to confirm the diagnosis should be performed in severely affected patients with renal disease.

Child↗

Bilateral congenital cholesteatoma in branchio-oto-renal syndrome.

Branchio-oto-renal syndrome is a rare autosomal dominant condition characterized by hearing loss, branchial arch abnormalities and renal tract malformations. We present the first reported case of branchio-oto-renal syndrome associated with bilateral congenital cholesteatoma and ossicular chain abnormalities. The pathogenesis of this syndrome is described and the literature is reviewed.

Branchio-Oto-Renal Syndrome↗

Cytokine overproduction in healthy first degree relatives of patients with IDDM.

Healthy family members of patients with insulin-dependent diabetes mellitus (IDDM) are known to share a number of immunological abnormalities with their affected relatives. Since monocyte and type 1 T-cell-derived cytokines contribute to the pathogenesis of IDDM, we studied the production of these cytokines in the healthy first degree relatives of 29 children with IDDM. We report that circulating tumour necrosis factor-alpha (TNF-alpha) and soluble interleukin-2 (sIL-2) receptor were present in increased amounts in non-diabetic family members at levels similar to those found in the diabetic children (duration of disease 3 months-5 years). Furthermore, marked hypersecretion of IL-1alpha and TNF-alpha by mitogen-stimulated peripheral blood mononuclear cells was found in both diabetic and healthy family members. Abnormalities of cytokine production in healthy relatives did not correlate with the presence of islet cell antibodies or with HLA DR type. These data indicate that healthy family members of patients with IDDM exhibit overproduction of a number of cytokines that have been implicated in diabetogenesis.

Adolescent↗

Hemodialysis catheter placement and recirculation in treatment of hyperammonemia.

A 2-year-old girl with carbamoyl phosphate synthetase deficiency underwent emergency hemodialysis (HD) for treatment of acute life-threatening hyperammonemia. HD was performed via catheters placed in each femoral vein serving as vascular access. The tip of one of the catheters (aspirating line) was in the left external iliac vein and the tip of the other catheter (the return line) was in the inferior vena cava (IVC). High blood flow rates were used in order to rapidly lower the blood ammonia (NH3) levels. However, unanticipated marked recirculation in the IVC, between the dialysis aspirating and return catheters, was encountered, preventing significant reduction in blood NH3. The recognition of this problem, suggested solutions, and prevention are described.

Ammonia↗

Relationships of cell proliferation and expression of integrin subunits and type I collagen in skin fibroblasts with renal lesions in patients with IDDM.

Previous studies have shown that cultured skin fibroblasts (SFs) from insulin-dependent diabetic mellitus (IDDM) patients with diabetic nephropathy (DN) exhibit both increased proliferation and Na+/H+ antiporter activity. The present study correlated the growth rate and mRNA expression of integrin subunits, extracellular matrix molecules, and transforming growth factor-beta in cultured SFs, with the biopsy determined rate of development of DN lesions ranging from slow to rapid in nine IDDM patients. These varying rates of development of DN lesions were expressed by a mesangial expansion score as estimated by the rate of change in mesangial fraction volume per year. Cultured SF proliferation by direct cell counts positively correlated with mesangial expansion score (r = 0.65; P < 0.05). Expression of cultured SF alpha3 integrin subunit mRNA levels, as well as type I collagen mRNA (P < 0.05 for both), but not transforming growth factor-beta mRNA levels (Northern blot analysis), were also positively correlated with mesangial expansion score. We postulate that these observations of correlations between activities of cultured SFs and the rate of progression of DN lesions may be predictive of the risk to develop clinical DN in IDDM, may be in part genetically regulated, and may be of pathogenetic importance.

Adult↗

Cost of extracorporeal life support in pediatric patients with acute respiratory failure.

OBJECTIVES: To determine the impact of extracorporeal life support (ECLS) on mortality in pediatric patients with acute hypoxemic respiratory failure (AHRF) at our institution; and to calculate the hospital charges associated with the use of ECLS. DESIGN: Retrospective review of medical records and hospital charges. SETTING: Pediatric intensive care unit (ICU) of a university-affiliated children's hospital. PATIENTS: Twenty patients admitted to the pediatric ICU between 1991 and 1995 for AHRF who received ECLS as a part of their hospital course. INTERVENTIONS: Predicted mortality was calculated using the Pediatric Respiratory Failure score and was compared with survival at the time of hospital discharge. Hospital charges were used as a proxy for resource utilization. Cost-per-life-year-saved calculations were performed based on a normal life expectancy for survivors. MEASUREMENTS AND MAIN RESULTS: Twenty patients were identified. The median age was 4.83 yrs. The median duration of ECLS was 9 days, with 19.5 days in the pediatric ICU and 23.5 days for the entire hospital length of stay. The observed mortality rate for these patients was 20%. Median predicted mortality rate based on the Pediatric Respiratory Failure score calculation was 83%. The hospital charges incurred by these patients was a median of $199,096. Based on a normal life expectancy for survivors, this results in a cost of $4,190/life-year. CONCLUSIONS: ECLS for the pediatric patient with AHRF is done at a considerable cost. However, ECLS affects survival favorably, and compares favorably when considering cost/life-year calculations. The data presented in this study may serve as a benchmark for comparison with newer therapies (i.e., liquid ventilation, nitric oxide). These data also provide a framework for cost-based analyses at other ECLS institutions.

Adolescent↗

Delayed acute renal failure in post-transplant period in young children from unexplained etiology.

This report describes six young children (5 male) who developed delayed acute renal failure (DARF) in the early post-kidney-transplant (Tx) period in the absence of acute rejection (AR) or other diagnosable conditions. These young children, aged 16.5 +/- 3.1 (12-21) months [mean +/- SD, (range)] and weighing 8.5 +/- 1.7 (7.1-11.4) kg received a primary renal Tx (5 living-related donor, 1 cadaver) between 1984 and 1992. Immunosuppression included prednisone, azathioprine, and Minnesota antilymphocyte globulin (MALG, n = 5); one patient received cyclosporine and no MALG. Initially, all patients had good urine output (UO). They became systemically ill and abruptly developed diminished UO on post-operative day (POD) 6.5 +/- 1 (4-8). DARF was accompanied by fever (39.1-40.4 degrees C, n = 6), thrombocytopenia (platelets < 100,000/mm3, n = 6), leukocytosis, or leukopenia (white cell count > 20,000/mm3, n = 4 or < 1,000/mm3, n = 1). Four patients had diarrhea. Three had ascites and one was surgically explored for suspected urinary leak. None showed significant urinary obstruction by renal ultrasound. Renograms showed intact blood flow. Renal biopsy showed tubular ectasia (n = 6), vascular congestion (n = 5), focal glomerular endothelial swelling (n = 4), and capillary thrombi (n = 3). None showed AR. Five patients required dialysis for 11 +/- 4 (7-15) days. All patients survived. One patient, treated for suspected AR with the monoclonal antibody OKT3, developed shock and lost her graft on POD 12 due to vascular thrombosis. Renal functional recovery in the remaining five patients took 14 +/- 5 (6-20) days and their serum creatinine at discharge was 0.7 +/- 0.5 (0.3-1.6) mg/dl. We report DARF from undetermined etiology occurring in the first 2 weeks of renal Tx in young children. Treatment is supportive care including dialysis. Recognition of this complication will help avoid risky investigations or unnecessary treatment for rejection.

Acute Kidney Injury↗

Modified Method for Competitive Reverse Transcription Polymerase Chain Reaction for Rapid and Automated Quantitation of Messenger RNA in Multiple Samples.

Background: Competitive reverse transcription polymerase chain reaction (RT-PCR) has been used increasingly to quantitate messenger RNA (mRNA) levels; however, conventional competitive RT-PCR methods require four or five reactions per sample of RNA, employing serial dilutions of an internal competitor sequence, making analysis of multiple samples of tedious process. A modified method is described by which multiple samples and multiple RNA transcripts can be analyzed easily by an automated process. Methods and Results: Transforming growth factor beta-1 (TGF-beta-1) mRNA was assayed in total RNA extracted from cultured human skin fibroblasts. A standard solution of total RNA was first prepared by pooling RNA from several cell lines and stored in aliquots. A 270-bp competitor RNA molecule (RNA mimic) was prepared by in vitro transcription and was added to each reaction. PCR was performed with a fluorescent dye (Hex; Applied Biosystems, Foster City, CA)-labeled sense primer to amplify a 161-bp-long c DNA product of target TGF-beta-1 mRNA sequence and the RNA mimic. The PCR products were analyzed with an automated laser-scanned gel electrophoresis system and the area under the curve (AUC) was used for quantitation. The concentration TGF-beta-1 mRNA in standard RNA was determined by conventional competitive RT-PCR. Subsequently, equal amounts of RNA mimic were mixed with four serial dilutions of standard RNA and 0.1 µg of sample total RNA for RT-PCR. A standard curve was generated using the known dilutions of a standard target RNA solution and ratio of AUC for target to that for mimic for each dilution. The unknown sample was then quantitated by interpolation of its area under the curve ratio on the standard curve. This method had inter- and intra-assay coefficients of variation of less than 10%. Conclusions: This modification is highly reproducible for quantitation of mRNA and significantly reduces the number of PCR reactions required for each assay. It can be used to assay several RNA molecules in a given sample by designing RNA mimics and PCR primers to generate PCR products of different lengths so that they can be analyzed by the laser scanning of a single lane of electrophoretic gel.

Journal Article↗