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Prakash J, Murthy AS, Vohra R, Rajak M, Mathur SK. Acute renal failure in the intensive care unit. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2006; 54:784-8. [PMID: 17214274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
BACKGROUND Acute renal failure (ARF) in the intensive care unit (ICU) is associated with high mortality. A thorough understanding of the clinical spectrum of the disease is needed in order to devise methods to improve the final outcome due to this problem. AIMS AND OBJECTIVES The aim of the present study was to analyze the clinical spectrum, causes, risk and prognostic factors and final outcome of ARF in the setting of ICU. METHOD This prospective study involved patients admitted to ICU during the period between September 2003 to January 2005 (17 months). Patients who developed ARF during the ICU stay were included in the study. The clinical and laboratory data were collected at admission and then on daily basis. Data recorded included; patient characteristics, underlying medical conditions responsible for ICU admission, dialytic status, need for ventilation, total duration of ICU stay, APACHE-III score and final outcome, and these data were analyzed for predicting survival using univariate and multivariate analysis. RESULTS Twelve hundred and fifteen (1215) patients were admitted to ICU from September 2003 to January, 2005 and 46 (3.79%) patients developed ARF after admission to ICU. Mean age of patients was 44.9 +/- 17 years and 56.5% were males. Comorbidity was seen in 24 (52%) patients; hypertension (34.7%), diabetes mellitus (28.3%), coronary artery disease (30.4%) and chronic kidney disease (13%). ARF had developed complicating medical and surgical conditions in 33 (71.7%) and 11 (23.7%) patients respectively. The etiology of ARF was multifactorial and included; hypotension (71.74%), volume depletion (17.4%), nephrotoxic drugs (67.39%), and sepsis (69.5%). Multiple organ system failure (MOSF) was noted in 63% of cases and dialysis was required in 25 (54.3%) patients. Mortality occurred in 63% of patients. MOSF and sepsis were found to be significant adverse prognostic factors when multiple logistic regression analysis was done. CONCLUSIONS ARF was seen in 3.79% of cases in our ICU and associated with poor prognosis. Presence of sepsis, MOSF, higher APACHE--III scores and ventilation need were correlated with higher mortality in ARF patients in the intensive care unit.
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Kakar A, Gupta A, Vohra R. Pseudogynaecomastia due to deltaparin. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2003; 51:738. [PMID: 14621055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
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Inman-Bamber J, Wan C, Gardam T, Vohra R, van Daal A, Timms P. Novel PCR-EIA method for the detection of Chlamydia pneumoniae in respiratory specimens. Mol Cell Probes 2002; 16:57-61. [PMID: 12005448 DOI: 10.1006/mcpr.2001.0399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We report the development of a microtitre plate-based PCR-EIA assay (ELAHA; Enzyme Linked Amplification and Hybridization Assay) for the sensitive and specific detection of Chlamydia pneumoniae in sputum samples from patients with chronic obstructive airways disease (COAD). Following PCR amplification of a segment of the chlamydial heat shock 60 protein gene, the 587 bp sized amplicon is captured onto the streptavidin coated surface of a microtitre plate using a C. pneumoniae specific biotinylated probe and the level of captured product is subsequently determined via a colorimetric reaction using an automated plate reader. The ELAHA is a simple, rapid and inexpensive method for detection of low levels of infectious agents and is readily adaptable to current clinical laboratory equipment. The assay was evaluated with a cohort of hospital respiratory patients: (i) COAD patients with acute exacerbation, (ii) COAD patients without exacerbation (stable) and (iii) a non-respiratory control group. The ELAHA produced 6/12 (50%) C. pneumoniae positives in the COAD with exacerbation group, 3/13 (23%) positives in the COAD without exacerbation group and only 1/6 (17%) positives in the control non-respiratory group. This sensitive and robust PCR-EIA method can provide clinically relevant diagnostic evidence of current C. pneumoniae infection contributing to serious respiratory tract diseases such as COAD.
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Sachdev A, Vohra R, Bijarnia S. Acute brucellosis of childhood: a case report with unusual features. Indian Pediatr 2001; 38:1421-5. [PMID: 11752745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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Rittoo D, Sintler M, Burnley S, Millns P, Smith S, Vohra R. Gelatine-resorcine-formol glue as a sealant of ePTFE patch suture lines. INT ANGIOL 2001; 20:214-7. [PMID: 11573055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
BACKGROUND ePTFE patch reconstruction has superior flow characteristics in preventing early thrombus formation during carotid endarterectomy. However prolonged bleeding at the suture line of the patch reconstruction is a problem. The aim of this study was to investigate whether the application of gelatine-resorcine-formol (GRF) glue at the suture line can improve local haemostasis. METHODS A prospective randomised trial of 40 consecutive patients undergoing carotid endarterectomy was undertaken. Patients were randomised to receive GRF glue as a topical haemostatic agent or to act as controls. Statistical analysis was performed using the Mann-Whitney test. RESULTS Although the patch size was significantly smaller in the control group (3.0 cm2 vs 4.3 cm2, p<0.001), local haemostasis was achieved in half the time when the glue was used (11 min vs 22, p<0.004). In the follow-up period ranging from 12 to 24 months, there have been no adverse effects related to the glue. Two patients died during the follow-up period. These deaths were neither related to the patch nor to the glue. CONCLUSIONS This study has shown that GRF glue is an effective sealant of ePTFE patch suture line. GRF glue does not compromise the patch's characteristics.
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Gosling P, Rittoo D, Manji M, Mahmood A, Vohra R. Hydroxyethylstarch as a risk factor for acute renal failure in severe sepsis. Lancet 2001; 358:581; author reply 582. [PMID: 11526921 DOI: 10.1016/s0140-6736(01)05718-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Rittoo D, Cramb R, Odogwu S, Khaira H, Duddy M, Smith S, Vohra R. Worsening lipid profile is associated with progression of carotid artery stenosis. INT ANGIOL 2001; 20:47-50. [PMID: 11342995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
BACKGROUND To determine if uncontrolled hypercholesterolaemia predisposes to progression of carotid artery stenosis. METHODS Fasting blood samples were collected from 76 patients referred for carotid duplex ultrasound for investigation of transient ischaemic attacks or recent stroke. Patients were grouped depending on the severity of the stenosis found. Patients on lipid lowering agents were excluded. The data were analysed using one way analysis of variance and the c2 test as appropriate. RESULTS There were more men in the 70-99% group (15 vs 6, c2 = 10.6, p < 0.001, Table I). The total cholesterol was raised in all three groups. Patients with carotid stenosis of 70-99% had significantly elevated triglycerides (2.4 mmol vs 1.47 mmol and 1.37 mmol, p < 0.003), low HDL (1.14 mmol vs 1.45 mmol and 1.18 mmol, p < 0.003) and a higher cholesterol/HDL ratio (5.56 vs 4.29 and 4.71, p < 0.014) compared with the other two groups. There was no difference in lipoprotein(a) in the three groups. CONCLUSIONS Increased triglycerides and low HDL cholesterol seen in the 70-99% group suggest that a worsening lipid profile is associated with progression of carotid artery stenosis.
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Murthy SA, Singh B, Bhalla S, Arora A, Vohra R, Aggarwal S. Cure in a case of primary hepatic lymphoma. Indian J Cancer 2000; 37:165-72. [PMID: 12018569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Primary hepatic lymphoma is rare malignancy. Cures in this disease are uncommon. We report a young male who was diagnosed as a case of primary lymphoma of the liver in 1992. He was treated with chemotherapy only, which included CHOP (Cyclophosphamide, Adriamycin, Vincristine and Prednisolone) - six cycles; and IMVP-16 (Ifosfamide, Methotrexate and Etoposide) -four cycles. The patient is now disease free and alive for more than five years.
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Buxi TB, Sud S, Vohra R, Kakkar A, Byotra SP. Giant spinal arachnoid cysts: computed tomography, magnetic resonance imaging and magnetic resonance myelography correlation. AUSTRALASIAN RADIOLOGY 2000; 44:216-9. [PMID: 10849990 DOI: 10.1046/j.1440-1673.2000.00801.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Two cases of giant spinal arachnoid cysts, one of them being symptomatic, are discussed, along with their CT, MRI and MR myelography findings.
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Japour CJ, Vohra R, Vohra PK, Garfunkel L, Chin N. Management of heel pain syndrome with acetic acid iontophoresis. J Am Podiatr Med Assoc 1999; 89:251-7. [PMID: 10349289 DOI: 10.7547/87507315-89-5-251] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This study was undertaken to determine the effectiveness of acetic acid iontophoresis in the treatment of heel pain. Thirty-five patients with chronic heel pain were treated with acetic acid iontophoresis over a 4-year period. Ninety-four percent of patients had complete or substantial relief of heel pain after an average of 5.7 sessions of acetic acid iontophoresis over an average period of 2.8 weeks. Heel pain levels were rated from 0 to 10, with 10 representing the most severe pain. Heel pain prior to iontophoresis treatment received an average rating of 7.5; by the end of therapy, the average rating had decreased to 1.8. At an average follow-up time of 27 months, heel pain levels averaged 0.64, indicating continued reduction in heel pain. Ninety-four percent of participants said that they would recommend acetic acid iontophoresis to someone with similar heel pain.
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Rao NN, Vohra R. Granular cell tumour. A case report. Indian J Dent Res 1997; 8:115-7. [PMID: 9586525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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Vohra R, Kang HS, Dogra S, Saggar RR, Sharma R. Tuberculous osteomyelitis. THE JOURNAL OF BONE AND JOINT SURGERY. BRITISH VOLUME 1997; 79:562-6. [PMID: 9250739 DOI: 10.1302/0301-620x.79b4.7618] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Tuberculous osteomyelitis which does not involve a joint is uncommon and may fail to be diagnosed by an orthopaedic surgeon. We treated 28 lesions of tuberculous osteomyelitis in 25 patients between 1988 and 1995. The duration of symptoms was from two to 39 months, and most of our patients had been treated initially with non-steroidal anti-inflammatory drugs which failed to provide relief. Bone pain which does not promptly respond to analgesic medication is often due to infection or neoplasia. In the early stages, when plain radiographs are normal, MRI or CT may help to localise lesions. On plain radiographs, more advanced lesions may mimic chronic pyogenic osteomyelitis, Brodie's abscess, tumours or granulomatous lesions. Biopsy is mandatory to confirm the diagnosis, and antituberculous drugs are the mainstay of treatment. When operative findings at biopsy have the features of skeletal tuberculosis curettage of the affected bone may promote earlier healing.
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Abstract
Tuberculous osteomyelitis which does not involve a joint is uncommon and may fail to be diagnosed by an orthopaedic surgeon. We treated 28 lesions of tuberculous osteomyelitis in 25 patients between 1988 and 1995. The duration of symptoms was from two to 39 months, and most of our patients had been treated initially with non-steroidal anti-inflammatory drugs which failed to provide relief. Bone pain which does not promptly respond to analgesic medication is often due to infection or neoplasia. In the early stages, when plain radiographs are normal, MRI or CT may help to localise lesions. On plain radiographs, more advanced lesions may mimic chronic pyogenic osteomyelitis, Brodie’s abscess, tumours or granulomatous lesions. Biopsy is mandatory to confirm the diagnosis, and antituberculous drugs are the mainstay of treatment. When operative findings at biopsy have the features of skeletal tuberculosis curettage of the affected bone may promote earlier healing.
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Carr HM, Vohra R, Sharma H, Smyth JV, Rooney OB, Dodd PD, Walker MG. Endothelial cell seeding kinetics under chronic flow in prosthetic grafts. Ann Vasc Surg 1996; 10:469-75. [PMID: 8905067 DOI: 10.1007/bf02000595] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Improved patency of endothelial cell seeded grafts relies on good initial adherence and cell retention when the circulation is restored. In this study human adult endothelial cells (HAECs) were used to evaluate the suitability of commercially available prostheses for seeding. Acutely seeded indium-111 oxine labeled HAECs were used to measure cell adherence to plain and fibronectin (FN)-coated expanded polytetrafluoroethylene (ePTFE), gelatin-impregnated Dacron (Gelseal), and collagen-impregnated Dacron (Hemashield) grafts. Cell loss from FN-coated prostheses, when exposed to a simulated human arterial blood flow of 200 ml/min in an artificial pulsatile circulation, was quantified from the loss of gamma activity from the graft over 24 hours, pressure in the circulation being reduced to 15 mm Hg to reduce fluid loss. Initial HAEC adherence (mean [SD]) to plain grafts was 3(1)%, 47(9)%, and 53(9)% for ePTFE, Gelseal, and Hemashield, respectively. This improved significantly with FN coating (78[6]%, 60[8]%, and 76[4]%). Cell retention after 24 hours of flow to FN-coated grafts was 16(10)%, 25(5)%, and 65(4)% and was confirmed qualitatively by scanning electron microscopy and environmental scanning electron microscopy. FN significantly improved initial cell adherence with Dacron grafts showing the better adherence. Cell retention after 24 hours of flow was better with FN-coated Dacron than with ePTFE but was best with Hemashield grafts.
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Crews D, Cantú AR, Rhen T, Vohra R. The relative effectiveness of estrone, estradiol-17 beta, and estriol in sex reversal in the red-eared slider (Trachemys scripta), a turtle with temperature-dependent sex determination. Gen Comp Endocrinol 1996; 102:317-26. [PMID: 8804562 DOI: 10.1006/gcen.1996.0075] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In many turtles the temperature during the middle of incubation determines the gonadal sex of the hatchling. Sex steroid hormones have been implicated in temperature-dependent sex determination in the red-eared slider turtle, Trachemys scripta; nonaromatizable androgens are involved in male sex determination and estrogens and aromatizable androgens in female sex determination. Administration of exogenous estradiol-17 beta to eggs incubating at a temperature that normally produces only males can overcome the effect of temperature and result in all offspring being female. Further, estradiol-17 beta and incubation temperature synergize to produce a greater feminizing effect at intermediate incubation temperatures that produce mixed sex ratios. This study demonstrates that, in the red-eared slider, there is a complex interaction between incubation temperature, different estrogens, and the dosage effect of each hormone. There are changes in potency of different estrogens with incubation temperature such that estriol is more potent than estrone and estradiol-17 beta at 26 degrees (an all-male producing incubation temperature), estrone and estriol are equipotent to each other and more potent than estradiol-17 beta at 28.8 degrees (an incubation temperature that produced a male-biased sex ratio), and estradiol-17 beta is more potent than estrone and estriol at 29 degrees (an incubation temperature that produced equal numbers of males and females). These changes may be due to differences in synergism between the hormones and incubation temperature. Estriol treatment also resulted in cranially hypertrophied oviducts at all incubation temperatures in a dose-dependent manner, whereas animals treated with estradiol-17 beta and estrone had normal oviducts. These results support the hypothesis that estrogens are involved in the final common pathway of female sex determination in this species.
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Buxi TB, Prakash K, Vohra R, Bhatia D. Imaging in phaeohyphomycosis of the brain: case report. Neuroradiology 1996; 38:139-41. [PMID: 8692424 DOI: 10.1007/bf00604800] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A case of multiple, conglomerated brain abscesses due to Xylohypha bantiana, with unique imaging features, is presented. This is the first culture-proven case of brain infection due to this fungus in the neuroimaging literature.
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Vohra R, Kang HS. Tuberculosis of the elbow. A report of 10 cases. ACTA ORTHOPAEDICA SCANDINAVICA 1995; 66:57-8. [PMID: 7863770 DOI: 10.3109/17453679508994641] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We treated 10 cases of tuberculosis of the elbow with a 9-month antitubercular drug regimen, and surgery when indicated. The diagnosis was confirmed in 8 cases by histopathological examination and 2 cases were treated on clinical radiographic grounds. The follow-up ranged from 1 year to 3 years. The results were excellent in synovial and extraarticular lesions. Only in cases with minimal involvement of articular cartilage was a good range of movement achieved.
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Williams IM, Vohra R, Farrell A, Picton AJ, Mortimer AJ, McCollum CN. Cerebral oxygen saturation, transcranial Doppler ultrasonography and stump pressure in carotid surgery. Br J Surg 1994; 81:960-4. [PMID: 7922086 DOI: 10.1002/bjs.1800810711] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Transcranial Doppler ultrasonography (TCD) of the middle cerebral artery (MCA), light-reflective cerebral oximetry and measurement of internal carotid artery stump pressure were compared as methods of monitoring cerebral perfusion during carotid surgery in 33 patients. Median cerebral oxygen saturation was 70 (range 62-85) per cent and TCD-measured mean blood velocity 42 (range 19-91) cm/s before carotid cross-clamping, falling to 68 (53-83) per cent and 16 (0-50) cm/s respectively on application of the clamps (P < 0.001). Stump pressure correlated closely with MCA blood velocity 30 s after the start of cross-clamping (rs = 0.58, P < 0.001), but not with cerebral oxygen saturation. A fall of 5 per cent or more in cerebral oxygen saturation following cross-clamp application was predicted by a decrease in mean MCA blood velocity of at least 60 per cent. Changes in cerebral oxygen saturation correlated significantly with systolic blood pressure throughout the perioperative period (rs = 0.41, P < 0.001). Significant falls in cerebral oxygenation were not predicted by low stump pressure but were associated with large reductions in the mean MCA blood velocity measured by TCD.
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Vohra R. Vascular Surgery; Current Questions. Arch Emerg Med 1993. [DOI: 10.1136/emj.10.1.60] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Anderson ID, Hill J, Vohra R, Schofield PF, Kiff ES. An improved means of faecal diversion: the trephine stoma. Br J Surg 1992; 79:1080-1. [PMID: 1422727 DOI: 10.1002/bjs.1800791031] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Twenty-four patients in whom trephine stoma formation was performed over a 4-year period are described. This procedure permits the formation of an end ileostomy or colostomy without laparotomy. It is simple, rapid, safe and allows speedy recovery. It is widely applicable and previous abdominal surgery is no contraindication. The procedure was impossible in two patients who required laparotomy and in a third in whom a loop colostomy was created. Operation time was shorter and postoperative opiate requirements less than when laparotomy was undertaken for stoma formation. Follow-up (median 1 year) of 17 patients confirmed a low incidence of complications (two prolapses, one parastomal hernia) after trephine stoma formation. This procedure is recommended as the preferred method of ileostomy or colostomy formation when laparotomy is not otherwise indicated.
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Welch M, Durrans D, Carr HM, Vohra R, Rooney OB, Walker MG. Endothelial cell seeding: a review. Ann Vasc Surg 1992; 6:473-84. [PMID: 1467191 DOI: 10.1007/bf02007007] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The concept of endothelial cell seeding, designed to provide vascular grafts with a nonthrombogenic lining, has progressed from crude animal experiments during the past two decades to detailed in vitro functional studies using human cells. Although favorable results have been obtained in animal studies this has yet to be translated to humans, where current application of these techniques has been limited to a very few clinical trials. The history, current status and future directions are reviewed herein.
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Carr HM, Vohra R, Welch M, Rooney OB, Sharma H, Walker MG. Fibronectin binding to gelatin-impregnated Dacron (Gelseal) prostheses. Artif Organs 1992; 16:342-5. [PMID: 10078272 DOI: 10.1111/j.1525-1594.1992.tb00529.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Endothelial cell adherence to uncoated gelatin-impregnated Dacron (Gelseal) is poor but can be significantly improved by precoating with a suitable basement membrane such as fibronectin. To assess the suitability of fibronectin-coated Gelseal for endothelial cell seeding, fibronectin binding to Gelseal and its dissociation kinetics were investigated. Fibronectin binding was quantified by radiolabeling human fibronectin with iodine 125, concentrations of 10, 25, 50, 150, and 250 micrograms/ml being used to coat Gelseal at 30, 60, and 90 min of incubation. The amount of fibronectin bound was directly proportional to the concentration used and increased with time of incubation (p < 0.05). However, the percentage attachment decreased with increasing concentration (p < 0.001). The number of molecules bound per centimeter squared of graft was calculated. In the first 30 min, 75% of bound fibronectin was lost after exposure to a flow rate of 200 ml/min in a pulsatile artificial circulation; thereafter, the fibronectin-Gelseal bond was stable for up to 2 h.
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Neena S, Asnani PJ, Bhandari S, Vohra R. Purification and kinetics of extracellular phospholipase A of Salmonella newport. Folia Microbiol (Praha) 1992; 37:205-9. [PMID: 1505883 DOI: 10.1007/bf02933148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Attempts were made to purify and study the kinetics of extracellular phospholipase A of Salmonella newport (6,8, eb; 1,2). The enzyme was purified by salt precipitation followed by gel filtration, using different grades of Sephadex. The enzymically active purified preparation was found to be a protein, having molar mass ranging between 43 and 67 kDa. The enzyme had a pH optimum at 7.5, giving 18.2 micrograms of lysophosphatidylcholine per mg protein. Its activity was enhanced by all metal ions except potassium, by solvents and surfactants except sodium dodecyl sulfate. It hydrolyzed the membrane phospholipids of red blood cells and was inhibitory to the growth of other microorganisms.
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Vohra R, Thomson GJ, Carr HM, Sharma H, Walker MG. The response of rapidly formed adult human endothelial-cell monolayers to shear stress of flow: a comparison of fibronectin-coated Teflon and gelatin-impregnated Dacron grafts. Surgery 1992; 111:210-20. [PMID: 1531272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Endothelial cells labeled with indium 111-oxine were seeded in supraconfluent densities onto fibronectin-coated expanded polytetrafluoroethylene (ePTFE) and gelatin-impregnated Dacron graft segments. These grafts with rapidly formed endothelial-cell monolayers were then exposed to varying shear stresses at flow rates of 200 and 300 ml/min, using tissue culture medium in an artificial flow circuit. As the loss of radioactivity represented endothelial-cell loss, cell retention was calculated by the ratio of counts recorded at different time points during 2 hours of flow to initial counts. Although initial cell adherence to gelatin-impregnated Dacron graft segments was poor compared to ePTFE, once cells were attached they resisted shear stress of flow better at 200 ml/min and equally well at 300 ml/min. The cell retention on fibronectin-coated ePTFE was 55.4 +/- 12.9% at 200 ml/min and 56.5 +/- 15.2% at 300 ml/min; cell retention for gelatin-impregnated Dacron graft segments was 69.0 +/- 6.0% and 66.5 +/- 5.5%, respectively. Qualitatively scanning electron microscopy of both ePTFE and gelatin-impregnated Dacron graft segments showed patchy coverage of grafts with cells. There was preferential attachment of endothelial cells to the nodes on ePTFE, although on gelatin-impregnated Dacron graft segments, cells conformed to the Dacron fibers at different levels and directions with evidence of bridging in the gaps between individual fibers. This study shows conclusively that rapidly formed endothelial-cell monolayers on ePTFE and gelatin-impregnated Dacron graft segments resisted a shear stress of flow equal to that seen in a femoropopliteal vein graft with significant cell retention at 2 hours.
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