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A Coumbe

Publications and source records attributed to A Coumbe.

At least 19 recordsLinked to original sources
PubMed1998

Venous gangrene of the lower limbs following aortic valve replacement for native valve endocarditis.

Bacterial endocarditis is a complex disease associated with high morbidity and mortality with complications that include acute heart failure and arterial embolism. Venous thrombosis of the lower limbs is not uncommon following all forms of surgery, but infrequent following cardiac surgery, and rarely progresses to venous gangrene. We report a case of bilateral lower-limb venous gangrene, in a 49-year-old female who underwent aortic valve replacement for native valve endocarditis. The possible aetiology of this complication is discussed.

Aortic Valve↗
PubMed1998

Appendiceal inflammation in ulcerative colitis.

AIMS: Previous uncontrolled reports have suggested that appendiceal inflammation may occur as a discontinuous lesion in ulcerative colitis. This study aims semiquantitatively to compare the prevalence and histological features of appendiceal inflammation in patients with ulcerative colitis and Crohn's disease, using colonic carcinoma and acute appendicitis specimens as controls. METHODS AND RESULTS: Surgical pathology records and original histological slides for the period 1980-1994 were examined. The prevalence of appendiceal inflammation in ulcerative colitis (24/50, 48%), was higher than in colonic carcinoma (5/65, 8%, P < 0.001), but was similar to that in Crohn's disease (14/27, 52%). Appendiceal inflammation with caecal sparing was seen in nine out of 24 specimens with ulcerative colitis (37%), two out of nine (22%) with Crohn's disease and five out of 65 (8%) with colonic carcinoma. Inflamed appendixes from patients with inflammatory bowel disease showed histological features typical of ulcerative colitis and Crohn's disease rather than acute appendicitis and were significantly less likely to have transmural inflammation. There had been a previous appendicectomy in 3% of ulcerative colitis patients compared with 8% of colonic carcinoma specimens and 21% (P < 0.01) Crohn's disease controls. CONCLUSION: In ulcerative colitis, as in Crohn's disease, appendiceal inflammation commonly occurs as a skip lesion and histologically resembles the colonic disease rather than acute appendicitis. The low prevalence of appendicectomy supports the hypothesis that the appendix itself may have a central role in the pathogenesis of ulcerative colitis.

Adolescent↗
PubMed1998

Quantitative assessment of the rheumatoid synovial microvascular bed by gadolinium-DTPA enhanced magnetic resonance imaging.

OBJECTIVE: To examine the relation between rate of synovial membrane enhancement, intra-articular pressure (IAP), and histologically determined synovial vascularity in rheumatoid arthritis, using gadolinium-DTPA enhanced magnetic resonance imaging (MRI). METHODS: Dynamic gadolinium-DTPA enhanced MRI was performed in 31 patients with knee synovitis (10 patients IAP study, 21 patients vascular morphometry study). Rate of synovial membrane enhancement was quantified by line profile analysis using the image processing package ANALYZE. IAP was measured using an intra-compartmental pressure monitor system. Multiple synovial biopsy specimens were obtained by a blind biopsy technique. Blood vessels were identified immunohistochemically using the endothelial cell marker QBend30 and quantified (blood vessel numerical density and fractional area). RESULTS: Median blood vessel numerical density and fractional area were 77.5/mm2 (IQR; 69.3-110.7) and 5.6% (IQR; 3.4-8.5) respectively. The rate of synovial membrane enhancement (median 2.74 signal intensity units/s, IQR 2.0-3.8) correlated with both blood vessel numerical density (r = 0.46, p < 0.05) and blood vessel fractional area (r = 0.55, p < 0.02). IAP did not influence the rate of enhancement. CONCLUSIONS: Gadolinium-DTPA enhanced MRI may prove to be a valuable technique for evaluating drugs that influence angiogenesis.

Adult↗
PubMed1997

Arrhythmogenic right ventricular dysplasia (ARVD): an overlooked and underdiagnosed condition?

We present three cases of arrhythmogenic right ventricular dysplasia causing or contributing to sudden death. These cases serve to highlight the range of clinical presentations and histological features seen in this rare and poorly understood condition. Arrhythmogenic right ventricular dysplasia (ARVD) is a cardiomyopathy characterized by a normal or mild increase in heart weight with right-sided heart dilatation. Typically a proportion of the right ventricular muscle is replaced by fat and fibrous tissue. Clinically, the condition is characterized by episodes of ventricular tachycardia and global dyskinesia of the right ventricle. It may cause ventricular fibrillation and sudden death, especially in young persons engaged in strenuous exercise or who experience severe emotional outburst. The aetiology of the condition is unknown, although it has been noted to show familial clustering in some cases.

Adolescent↗
PubMed1996

Activation of the transcription factor nuclear factor-kappaB in human inflamed synovial tissue.

OBJECTIVE: The transcription factor nuclear factor kappaB (NF-kappaB) has been implicated in the inflammatory response and is known to be activated by a process involving reactive oxygen intermediates. The purpose of the present study was to demonstrate the presence and distribution of activated NF-kappaB in synovium samples from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and from autopsy subjects with no known history of arthritis. METHODS: Immunohistochemical staining was performed using both polyclonal and monoclonal "activity-specific" antibodies to the Rel-A (p65) subunit of NF-kappaB (anti-Rel-A nuclear location sequences). Histologic features of inflammation were also scored. RESULTS: Both antibodies demonstrated positive staining of synovial tissue, with a cellular distribution that was nuclear. The staining was associated with specific cell types within the tissue, in particular, type A synoviocytes and vascular endothelium. Notably, lymphoid aggregates were unstained. Using the monoclonal antibody, a further study was carried out to investigate the distribution of staining in tissues from patients with different disease activities and clinical diagnoses, as well as in normal control tissue obtained at autopsy. Patients with acute RA more commonly showed vessel staining (P = 0.05) and, conversely, showed less frequent staining of the synovial lining (P < 0.005) compared with OA patients. Synovial tissue from controls exhibited either no staining or only weak staining in the synovial lining. CONCLUSION: The activation of NF-kappaB in vascular endothelium and type A synovial lining cells is a feature of synovial tissue from both RA and OA patients. The distribution of this staining appears to be related to the clinical diagnosis.

Aged↗
PubMed1996

Evaluating the antioxidant potential of new treatments for inflammatory bowel disease using a rat model of colitis.

BACKGROUND: Reactive oxygen species may mediate tissue injury in inflammatory bowel disease. Aminosalicylates have antioxidant activity and the antioxidants, superoxide dismutase and allopurinol, are of reported benefit in inflammatory bowel disease. AIM: To develop a convenient technique for testing the antioxidant potential of standard and novel therapeutic agents for use in inflammatory bowel disease. METHODS: Amplified chemiluminescence was used to measure reactive oxygen species production by colonic biopsy specimens from rats with acetic acid induced colitis and to assess the in vitro effect of conventional antioxidants, standard therapies and proposed novel therapies for inflammatory bowel disease. RESULTS: The model was validated by demonstrating that the profile of effects on chemiluminescence of acetic acid induced colitis biopsy specimens given by conventional antioxidants (sodium azide, catalase, copper-zinc superoxide dismutase, dimethyl sulphoxide, N-acetylcysteine and ascorbate) and standard therapies (5-aminosalicylate and hydrocortisone) resembled that previously reported using biopsy specimens from ulcerative colitis. Human recombinant manganese superoxide dismutase did not alter chemiluminescence. Two novel compounds, LY231617 (10 mM) and amflutizole (20 mM), reduced chemiluminescence by 98% (n = 5, p = 0.009) and 88% (n = 5, p = 0.03), respectively. CONCLUSIONS: The similarity of the chemiluminescence responses of colonic biopsy specimens from acetic acid induced colitis and ulcerative colitis to a range of conventional antioxidants and standard treatments suggests that this model is a useful method for testing the antioxidant potential of new therapies for inflammatory bowel disease. The antioxidant actions of dimethyl sulphoxide, ascorbate, and the novel compounds, amflutizole and LY231617 in this model suggest that these agents merit further assessment in the treatment of inflammatory bowel disease.

Acetic Acid↗
PubMed1995

Quantification of rheumatoid synovitis by magnetic resonance imaging.

OBJECTIVE: To develop a method for quantifying acute synovial inflammation in rheumatoid arthritis (RA), utilizing magnetic resonance imaging (MRI). METHODS: Gadolinium-diethylenetriamine pentaacetic acid-enhanced MRI was performed in 21 patients with knee synovitis. Changes in synovial membrane signal intensity were identified and quantified by line profile analysis. Multiple synovial biopsies were obtained by a blind biopsy technique, and standard clinical and laboratory measurements of disease activity were recorded. RESULTS: The rate of synovial membrane enhancement correlated with histologic features of acute inflammation (r = 0.63, P < 0.01), but not with clinical or laboratory assessments. CONCLUSION: Dynamic MRI is a valuable technique for assessing acute synovial inflammation in RA.

Adult↗
PubMed1995

PPD and hsp65 induced monoarthritis initiates spontaneous recurrent flares in Lewis rats.

OBJECTIVES: To investigate the time course of a monoarthritis induced with the purified protein derivative of tuberculin (PPD) or a recombinant 65 kDa heat shock protein (rhsp65) in two different strains of sensitised rats. METHODS: Wistar and Lewis rats, sensitised with heat killed Mycobacterium tuberculosis in oil, were challenged intraarticularly with PPD or rhsp65 and monitored for six weeks. Inflammation was assessed by joint swelling, histology, and radiographic studies. RESULTS: Sensitised Lewis rats injected with PPD or rhsp65 showed a chronic response with recurrent spontaneous flares, while Wistar rats showed one inflammatory episode. CONCLUSIONS: The Wistar strain response to PPD resembles a transient reactive arthritis, while the response of the Lewis strain mimics the relapsing nature of rheumatoid synovitis, providing an interesting model to determine dominant immunopathogenic mechanisms.

Acute Disease↗
PubMed1995

Effect of intraluminal application of tissue-type plasminogen activator on the fibrinolytic activity of experimental vein grafts.

OBJECTIVE: The aim was to quantify the effect of intraluminally applied tissue-type plasminogen activator (tPA) on the fibrinolytic activity of experimental vein grafts and assess the effect of pretreatment of the vein on early platelet and thrombus formation using histological techniques. METHODS: A pig model of bilateral saphenous venin-carotid artery grafts was used. In each animal one side of the neck was grafted using vein distended to 230 mm Hg and pretreated with tPA (1 mg.ml-1) for a period of 15 min before grafting (treated graft). The perfused in situ for 2 h after implantation and before analysis. Changes in local fibrinolytic activity were quantified using fibrin plate techniques and specific chromogenic assays for tPA and urokinase (uPA) in tissue extract (n = 6 animals). Histological assessment was made using light and scanning microscopy (n = 4 animals). RESULTS: Surgical preparation and distention significantly reduced the fibrinolytic activity of pig saphenous vein in terms of areas of lysis produced on fibrin plates (P < 0.05), tPA activity (P < 0.05), and uPA activity (P < 0.05). Pretreatment of distended vein with tPA before grafting significantly enhanced its fibrinolytic activity after 2 h perfusion compared to control (untreated) grafts, as assessed by areas of lysis on fibrin plates (P < 0.05) and specific tPA activity (P < 0.05). Treated grafts also showed qualitatively less platelet and thrombus formation on histological examination. CONCLUSIONS: Pretreatment of surgically harvested vein by intraluminal application of tPA before grafting enhances its fibrinolytic activity after exposure to 2 h perfusion in vivo. This technique requires further investigation to validate its potential as a means of providing local anticoagulation to veins implanted as arterial grafts thereby reducing the incidence of early graft thrombosis.

Animals↗
PubMed1993

Effect of vascular clamp on endothelial integrity of the internal mammary artery.

The preservation of endothelial integrity is essential for maintaining patency of vascular grafts. The internal mammary artery flow is often interrupted with the application of a soft vascular clamp to achieve a bloodless field during the anastomosis. We investigated the effect of the vascular clamp on the internal mammary artery endothelium using the scanning electron and light microscope. The endothelium was examined before and at 15 and 30 minutes after clamping in both the pedicled and the skeletonized arteries. Endothelial integrity was breached by clamping with early evidence of platelet adhesion to the damaged areas. The severity of the endothelial damage was related to the clamp time, but there was no difference in the degree of damage between the pedicled and the skeletonized arteries. We conclude that the vascular clamp causes injury to the internal mammary artery endothelium and may be implicated in early postoperative graft failure.

Constriction↗
PubMed1993

Melanotic neuroectodermal tumour of infancy.

The melanotic neuroectodermal tumour of infancy is a rare, pigmented neoplasm that most frequently arises from the anterior maxillary alveolar ridge. It presents in the first few months of life, and usually follows a benign course. A classical case is presented and the clinical, radiological and pathological characteristics are discussed. The importance of early conservative surgical excision is emphasized with, in general, a good prognosis. This tumour, which many otolaryngologists may not be familiar with, should be included in the differential diagnosis of head and neck neoplasms in infants and young children.

Humans↗
PubMed1993

Pathological sequelae of implantation of intracorporeal left ventricular assist devices in the calf.

Thromboembolic complications have previously been a major pathological complication of left ventricular assist device (LVAD) insertion and appear to be a consequence of the use of smooth polyurethane linings. Textured biomaterial surfaces are designed to attract a stable coagulum which becomes organized to form a neointima. We describe the pathological changes following experimental implantation of textured-surface LVADs in calves. The incidence of systemic embolization from such linings appears to be low. Surface modifications with cell seeding offer the possibility of further reduction in incidence of this problem. However, degradation of prosthetic valves may be a potential source of emboli and infection. With these complications minimized, the most significant pathological changes observed appear to relate to the device haemodynamics. At present renovascular changes associated with systemic hypertension appear to be the greatest potential problem for the long-term use of these devices.

Animals↗