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Biomedical subjects

I F Lane

Publications and source records attributed to I F Lane.

At least 37 records · Page 2Linked to original sources
PubMed1995

Lupus anticoagulant in patients with peripheral vascular disease: a prospective study.

OBJECTIVE: To assess the incidence of lupus anticoagulant (LAC) in patients with peripheral vascular disease. DESIGN: Prospective clinical study. SETTING: University Hospital. MATERIALS: 20 patients with claudication (group 2), 20 patients with critical ischaemia (group 3) and 20 patients prior to elective abdominal aortic aneurysm surgery (group 4) were compared to 20 general surgical controls (group 1). CHIEF OUTCOME MEASURES: Venous blood samples for coagulation assay. MAIN RESULTS: Positive results for LAC by the Dilute Russell's viper venom time (DRVVT) with the platelet neutralisation procedure were present in 26 out of 60 vascular patients compared with none of the 20 general surgical controls. The three vascular groups showed a similar prevalence of LAC and this differed significantly from that in the control group (chi 2 = 10.94, p = 0.0009). Of the 26 positive results only three were associated with an abnormal activated partial thromboplastin time (APTT), which has previously been used as a marker for the presence of LAC activity. Fibrinogen levels were raised in seven of 20 patients in group 2 but were normal in the remaining vascular groups (p = 0.001). The mean factor VII level (124.1 units dl-1) in group 2 was higher than the mean of the remaining vascular patients (109.3 units dl-1, p < 0.05). CONCLUSIONS: The high prevalence of LAC in patients with peripheral vascular disease and the associated increased risk of early graft thrombosis may justify routine testing by DRVVT prior to reconstructive vascular surgery. Treatment of these patients with antiplatelet agents or formal anticoagulation perioperatively should be considered.

Aged↗
PubMed1995

Vascular trauma in civilian practice.

Vascular trauma is associated with major morbidity and mortality, but little is known about its incidence or nature in Britain. A retrospective study of 36 patients requiring operative intervention for vascular trauma under one vascular surgeon over a 6-year period was undertaken. Twenty-four patients suffered iatrogenic trauma (median age 61 years); including cardiological intervention (19), radiological intervention (2), varicose vein surgery (1), umbilical vein catherisation (1) and isolated hyperthermic limb perfusion (1). There were 23 arterial and three venous injuries. Twelve patients had accidental trauma (median age 23 years). Three of the ten patients with blunt trauma were referred for vascular assessment before orthopaedic intervention, two after an on-table angiogram and five only after an initial orthopaedic procedure (range of delay 6 h to 10 days). Injuries were arterial in nine, venous in two and combined in one. Angiography was obtained in six patients, and in two patients with multiple upper limb fractures identified the site of injury when clinical localisation was difficult. A variety of vascular techniques were used to treat the injuries. Two patients died postoperatively and one underwent major limb amputation. Thirty-two (89%) remain free of vascular sequelae after a median follow-up of 48 months (range 3-72 months). Vascular trauma is uncommon in the United Kingdom. To repair the injuries a limited repertoire of vascular surgery techniques is needed. Therefore, vascular surgical assessment should be sought at an early stage to prevent major limb loss.

Accidents↗
PubMed1994

Intravenous digital subtraction angiography versus computed tomography in the assessment of abdominal aortic aneurysm.

Results of preoperative investigation of 127 patients who underwent elective aortic aneurysm repair during a 3-year period were examined and compared with findings at operation. The accuracy of preoperative computed tomography (CT) and intravenous digital subtraction angiography (DSA) in assessing proximal and distal aneurysm extent was compared. From a total of 118 CT scans, ten of 12 suprarenal aneurysms were correctly predicted, with 11 false positives (positive predictive value 48 per cent, sensitivity 83 per cent, specificity 90 per cent). After 103 DSA investigations, six of ten suprarenal aneurysms were correctly predicted with one false positive (positive predictive value 86 per cent, sensitivity 60 per cent, specificity 99 per cent). Using CT, 30 of 54 aneurysmal iliac arteries were correctly diagnosed with 20 false positives (positive predictive value 60 per cent, sensitivity 56 per cent, specificity 88 per cent). Thirty-six of 48 aneurysmal iliac arteries were diagnosed correctly using DSA, with 32 false positives (positive predictive value 53 per cent, sensitivity 75 per cent, specificity 79 per cent). Intravenous DSA also provided useful information about renal and peripheral occlusive disease. Both investigations have their own specific limitations; clinicians should be aware of these when ordering and interpreting them.

Angiography, Digital Subtraction↗
PubMed1994

Inappropriate neutrophil activation in venous disease.

Neutrophil oxygen radical production was studied in 18 limbs with class 2 or 3 venous disease and compared with that of nine normal limbs. Neutrophils were isolated from arm and leg venous samples. Free radical production was determined using chemiluminescence after stimulation with the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (FMLP) or the ester phorbol myristate acetate (PMA). The ratio of leg to arm luminescence was greater after FMLP stimulation in patients with venous disease (median 1.52 (95 per cent confidence interval (c.i.) 1.27-2.60)) than in controls (median 0.97 (95 per cent c.i. 0.70-1.12); P < 0.01). These changes were not observed with PMA (venous disease 1.16 (95 per cent c.i. 1.05-1.40); controls 0.95 (95 per cent c.i. 0.78-1.24)). There were fewer FMLP receptors on activated leg neutrophils (median 20.19 (95 per cent c.i. 3.58-51.42) fluorescence units) than arm neutrophils (median 36.03 (95 per cent c.i. 13.00-65.28) fluorescence units; P < 0.05), indicating an amplification of signal transduction. Intracellular calcium imaging demonstrated a larger release of calcium after stimulation of leg neutrophils (median 25.0 per cent (95 per cent c.i. 15.7-43.9 per cent)) compared with neutrophils from the arm (median 8.0 per cent (95 per cent c.i. 5.6-16.1 per cent); P = 0.04), demonstrating calcium-dependent activation. Neutrophils in patients with chronic venous disease inappropriately produce more oxygen free radical as a result of amplification of a calcium-dependent signal pathway.

Aged↗
PubMed1993

Acute intestinal ischaemia: options in surgical management.

Seven patients (mean age 67 years, range 52-82 years) presented with acute intestinal ischaemia over a 4-year period. Massive bowel resection was performed in all patients. Exteriorisation and secondary restoration of intestinal continuity was employed in four patients. In two patients a primary anastomosis was performed at the time of resection and one patient underwent a 'second-look' procedure. Massive bowel resection and exteriorisation allows direct observation of stoma viability, avoids the risk of anastomotic breakdown and should be considered in all but moribund patients with acute intestinal ischaemia. In elderly patients resection and primary anastomosis may be an alternative option.

Aged↗
PubMed1992

Adenocarcinoma of the middle ear with osteolysis of the tympanic bulla in a cat.

Peripheral vestibular disease and lethargy were attributed to an adenocarcinoma in the middle ear of a 10-year-old cat. The tumor was invasive, inducing severe lysis of the tympanic bulla and adjacent temporal bone. Direct invasion to the meninges and brainstem also was observed. Neoplasms of the middle ear are rare in cats, with squamous cell carcinomas reported most commonly, but should be considered as causes of chronic otitis or signs of peripheral vestibular disease.

Adenocarcinoma↗
PubMed1990

A specific thromboxane receptor blocking drug, AH23848, reduces platelet deposition on vascular grafts in man.

The antithrombotic effect of a specific thromboxane A2 receptor blocking drug, AH23848, on radio-labelled platelet deposition in mature Dacron aorto-bifemoral grafts has been evaluated in patients. Thirty patients were randomly allocated to AH23848 70 mg, aspirin 300 mg plus dipyridamole 75 mg or placebo 8-hourly for 9 days. AH23848 inhibited platelet aggregation induced by the thromboxane A2 mimetic U-46619; no such effect was observed with aspirin plus dipyridamole. 111In-platelet uptake was measured as the thrombogenicity index (TI) which is a measure of the daily rate of accumulation of platelets by the graft. The mean (s.e. mean) value of 0.193 (0.029) on placebo was significantly reduced to 0.115 (0.022) by AH23848 (p less than 0.05) but only to 0.175 (0.028) by aspirin plus dipyridamole. There was no difference in mean platelet life span between the three treatment groups. The pronounced antithrombotic effect of AH23848 implicates thromboxane A2 in the process of platelet deposition in arterial prostheses and demonstrates the considerable promise of thromboxane receptor blocking drugs as antithrombotic therapy.

Aged↗
PubMed1988

Pulmonary microembolization in experimental aortic surgery.

Pulmonary dysfunction frequently follows major surgery and has many features identical to "shock lung'. A porcine model of aortic surgery is described in which 111In-labelled platelet kinetics were related to subsequent pulmonary function. In 14 pigs, standardized aortic surgery resulted in reproducible shock and a 50 per cent mortality at 3 days. Cardiac output fell from 2.3 +/- 0.2 to 1.0 +/- 0.1 litres min-1 following removal of the aortic clamp and mean platelet and leucocyte counts fell from 437 +/- 48 to 252 +/- 39 x 10(9) litres-1 and 21.7 +/- 1.5 to 12.9 +/- 1.2 x 10(9) litres-1 respectively (P less than 0.01). Aggregate levels in inferior vena caval blood were maximal at this time and radiolabelled platelets accumulated in the lung with a rise in pulmonary vascular resistance. Alveolar-arterial oxygen difference subsequently increased from initial values of 13.7 +/- 2.0 to 23.4 +/- 3.5 mmHg (P less than 0.01) following resuscitation and to 32.5 +/- 3.4 mmHg at 3 days following surgery (P less than 0.01). This clear sequence suggests that pulmonary platelet microembolization occurs during surgical shock and may be responsible for subsequent pulmonary dysfunction.

Animals↗
PubMed1988

Platelet kinetics following carotid endarterectomy: the effect of aspirin and patch angioplasty.

Platelet deposition on the subintimal surface of the arterial wall following endarterectomy has been implicated in the development of postoperative thrombosis, intimal hyperplasia and may be important in recurrent stenosis. Autologous radiolabelled platelet deposition has been measured in 51 patients following carotid endarterectomy. The effect of platelet inhibitory drugs and patch angioplasty on early postoperative platelet accumulation at the site of endarterectomy has been investigated. In patients undergoing direct suture of the arteriotomy, platelet deposition measured as the Carotid Uptake Ratio was significantly reduced from 1.44 +/- 0.03 to 1.11 +/- 0.35 in those receiving aspirin and dipyridamole (P less than 0.002). Carotid Uptake Ratio was greater following patch angioplasty at 1.41 +/- 0.07 when compared to 1.14 +/- 0.07 with direct suture of the arteriotomy (P less than 0.002).

Aspirin↗
PubMed1988

An evaluation of Dacron prostheses in the relief of jaundice due to malignant obstruction.

In 26 patients, relief of obstructive jaundice due to malignancy has been effected by inserting a Dacron biliary-enteric prosthesis. All cases were considered unsuitable for conventional biliary bypass procedures. The hospital mortality was 27% and mean survival of those patients discharged was 8 months. Insertion of a Dacron prosthesis may prove an alternative to percutaneous biliary stenting in selected patients with neoplastic biliary obstruction.

Adenocarcinoma↗
PubMed1986

Strategy for lymph node biopsy in homosexual men suspected of having LAV/HTLV-III related disease.

Since January 1985 we have changed our policy regarding lymph node biopsy in male homosexuals presenting with lymphadenopathy. Before that date all such patients underwent biopsy if there was no apparent cause. We no longer perform biopsy in male homosexuals presenting with uncomplicated persistent generalized lymphadenopathy (enlargement to more than 1 cm of lymph nodes in more than one extra-inguinal site for more than 3 months with no apparent cause) provided that the patient is positive for the antibody to lymphadenopathy associated virus/human T-lymphotropic virus type III. Such a policy should reduce the need for open biopsy procedures in this group of patients.

Adult↗
PubMed1986

Colonic haemorrhage: a technique for rapid intra-operative bowel preparation and colonoscopy.

We describe a new technique of operative orthograde colonic washout followed by colonoscopy for use in patients with severe colonic haemorrhage. We report its use in four patients in whom the exact source of bleeding was localized and treated. In two of these cases a policy of 'blind' hemicolectomy would have been incorrect. The technique is simple and safe, and we advocate its use during laparotomy for major colonic haemorrhage.

Aged↗
PubMed1986

Effect of the cyclo-oxygenase inhibitor indobufen on platelet accumulation in prosthetic vascular grafts.

An in vivo method of measuring thrombus deposition and pseudo-intimal thickening in prosthetic arterial grafts in an animal model is described. The effect of indobufen, a new cyclo-oxygenase inhibitor, was evaluated and compared to aspirin plus dipyridamole and placebo in 24 greyhounds. Luminal platelet accumulation expressed as thrombogenicity index was 0.33 +/- 0.07 in the placebo group. This was significantly reduced to 0.14 +/- 0.01 by indobufen (P less than 0.05). The reduction to 0.19 +/- 0.04 by aspirin plus dipyridamole failed to achieve statistical significance. Pseudointimal thickness when measured 28 days after implacement was significantly reduced to 21.4 +/- 10.6 per cent by indobufen (P less than 0.01) and 29.4 +/- 10.6 per cent by aspirin plus dipyridamole (P less than 0.02) compared to 75 +/- 10 per cent found in the placebo group. This prosthetic graft model has considerable advantages in the evaluation of potential platelet inhibitory drugs for use in vascular surgery.

Animals↗
PubMed1986

Hypercholesterolaemia accentuates platelet activity.

Platelet aggregation response to collagen has been studied in 20 rabbits, randomly allocated to receive a normal (control) or high cholesterol diet. The sensitivity of platelets to collagen was significantly higher in the hypercholesterolaemic group (p less than 0.01) compared to controls. All hypercholesterolaemic rabbits developed generalised atherosclerosis and this may be due to increased circulating platelet activity.

Animals↗