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Featured researches published by T.C. Northfield.


Gastroenterology | 1986

NATURE OF THE BLEEDING VESSEL IN RECURRENTLY BLEEDING GASTRIC-ULCERS

C. Paul Swain; David W. Storey; S. G. Bown; Jean Heath; Timothy Noel Mills; P.R. Salmon; T.C. Northfield; J. Squire Kirkham; Jerry P. O'Sullivan

An unselected consecutive series of 826 patients admitted for acute upper gastrointestinal bleeding underwent urgent endoscopy. Peptic ulcers were found in 402 (49%). Of the 329 ulcer craters that could be fully examined, visible vessels were identified in 156 (47%), other stigmata of recent hemorrhage in 66, and no stigmata of recent hemorrhage in 107. One hundred twenty-nine patients with stigmata of recent hemorrhage (93 of whom had visible vessels) randomly allocated to no endoscopic treatment were observed for evidence of further bleeding. Fifty-four of the 93 patients (58%) with visible vessels rebled, compared with 2 of 36 (6%) with other stigmata of recent hemorrhage. No patient without stigmata of recent hemorrhage rebled. Twenty-seven patients in whom a visible vessel in a gastric ulcer was identified at endoscopy underwent urgent partial gastrectomy because of recurrent bleeding. The vessel identified at endoscopy was found in 26 of 27 resection specimens (96%). The arterial vessel wall protruded above the surface of the ulcer crater in 10 specimens, and clot in continuity with a breach in the vessel wall protruded in a further 10 specimens. Postoperative angiography, when technically possible, showed that the breached artery ran across the base of the ulcer in all of these specimens. Pathological changes were common in the bleeding artery and included arteritis in 24 of 29 (83%) eroded arteries found in these specimens, with aneurysmal dilatation in 14 of 27 (52%) bleeding points that could be fully examined. The ulcer had penetrated to serosa in 13 specimens (45%). The bleeding artery had a mean external diameter of 0.7 mm with a range of 0.1-1.8 mm. This study provides new information about the nature of the bleeding vessel in gastric ulcers, and some of this information is relevant in planning studies of endoscopic therapy for bleeding peptic ulcers. It validates the endoscopic identification of a visible vessel, and confirms that such identification has a high predictive value for the development of recurrent hemorrhage.


Gastroenterology | 1987

Biological Effects of Intrahepatic Neodymium:Yttrium-Aluminum-Garnet Laser Photocoagulation in Rats

K. Matthewson; P. Coleridge-Smith; Jerry P. O'Sullivan; T.C. Northfield; S. G. Bown

The effects of low-power neodymium:yttrium-aluminum-garnet laser light delivered intrahepatically in normal rats have been studied. Power settings of 0.5-2.0 W and exposures of 50-2400 s produced well-defined, highly reproducible necrotic lesions of up to 16 mm in diameter. The diameter of the necrotic lesions depended upon both the power setting and total energy delivered. Histologic examination showed coagulative necrosis that healed by granulation with a small residual fibrous nodule by 60 days. Microthermocouples embedded within the liver indicated temperatures of up to 100 degrees C close to the fiber tip for the higher power settings, and temperatures at the periphery of the necrotic zones were consistent with tissue damage by a purely thermal effect. Radiologic examination of photocoagulated lobes of liver in which arterial tree had been filled with a radiopaque polymer demonstrated loss of all small and some large vessels in the treated area. The technique could be used to induce necrosis of intrahepatic and other tumors.


The Lancet | 1986

CONTROLLED TRIAL OF Nd-YAG LASER PHOTOCOAGULATION IN BLEEDING PEPTIC ULCERS

C.P. Swain; P.R. Salmon; J.S. Kirkham; S. G. Bown; T.C. Northfield

The efficacy of Nd-YAG laser photocoagulation in the endoscopic control of haemorrhage from peptic ulcers was shown in a controlled trial. 527 patients admitted consecutively with acute upper gastrointestinal haemorrhage underwent urgent endoscopy. Peptic ulcers were seen in 260. All 138 ulcer patients with stigmata of recent haemorrhage (SRH) accessible to laser therapy were included in the trial (26 inaccessible, 96 no SRH). Patients were stratified into three groups--those with a visible vessel, those with other SRH, and those with clot that could not be washed off before therapy. Laser and control groups were well matched for other factors known to influence prognosis. Overall, 7/70 laser-treated and 27/68 control ulcers rebled (p less than 0.001). Rebleeding occurred from 6/39 treated and 23/43 control ulcers with a visible vessel (p less than 0.001); 0/17 treated and 1/13 ulcers with other SRH (NS); and 1/13 treated and 2/11 control ulcers with overlying clots (NS). 7/70 treated but 24/68 controls required emergency surgery (p less than 0.005). 1 treated patient but 8 control patients died after an episode of rebleeding (p less than 0.05).


The Lancet | 1981

CONTROLLED TRIAL OF ARGON LASER PHOTOCOAGULATION IN BLEEDING PEPTIC ULCERS

C.P. Swain; D.W. Storey; T.C. Northfield; S. G. Bown; J.S. Kirkham; P.R. Salmon

The efficacy of argon laser photocoagulation in the endoscopic control of haemorrhage from peptic ulcers was tested in a controlled trial at two centres in London. Of 330 patients consecutively admitted with acute upper gastrointestinal tract haemorrhage, 76 were seen at endoscopy to have a peptic ulcer accessible to laser therapy and stigmata of recent haemorrhage. These patients were included in the trial. Identification of the exact source of haemorrhage within the ulcer crater was achieved by use of standard endoscopes with careful washing. Patients were stratified into three groups: ulcers with a visible vessel (52 total, 11 actively spurting); those without a vessel (17); and those with an overlying clot persisting after washing (7). Of the 52 patients with visible vessel, 8 of 24 treated with the laser and 17 of 28 control patients had a further haemorrhage. 7 control patients died after an episode of rebleeding, but no treated patients. Treated and control patients were well matched for other factors known to influence the case fatality rate. This is the first controlled trial to demonstrate a significant reduction in mortality by the use of a non operative treatment in patients with bleeding peptic ulcers.


Gastroenterology | 1990

Randomized Comparison of Nd YAG Laser, Heater Probe, and No Endoscopic Therapy for Bleeding Peptic Ulcers

Kenneth Matthewson; C. Paul Swain; Martin Bland; J. Squire Kirkham; Stephen G. Bown; T.C. Northfield

Of 550 patients admitted with acute upper gastrointestinal hemorrhage, 143 with peptic ulcers containing stigmata of recent hemorrhage accessible to endoscopic therapy were included in a randomized comparison of neodymium yttrium aluminum garnet laser, heater probe, and no endoscopic therapy. The rebleeding rate in laser-treated patients (20%) was significantly less than in controls (42%; p less than 0.05), but in heater probe-treated patients (28%) it was not significantly different from either of the other two groups. The mortality rate in the laser group (2%) was not significantly different from either the heater probe (10%) or the control (9%) group. This trial has confirmed the efficacy of the Nd YAG laser but not that of the heater probe in the prevention of rebleeding from recently bleeding peptic ulcers.


Gastroenterology | 1984

Comparative study of the safety and efficacy of liquid and dry monopolar electrocoagulation in experimental canine bleeding ulcers using computerized energy monitoring

C. Paul Swain; Timothy Noel Mills; Julia M. Dark; Michael Lewin; S. G. Bown; T.C. Northfield; Jerry P. O'Sullivan; P.R. Salmon


The Lancet | 1982

Argon laser photocoagulation in bleeding peptic ulcers.

T.C. Northfield; C.P. Swain; J.S. Kirkham; D.W. Storey; S. G. Bown; P.R. Salmon


Gastroenterology | 2000

Healthcare and productivity costs for managing non-ulcer dyspepsia: Is H. pylori relevant?

Maxwell A. Asante; Joanne Lord; T.C. Northfield


Clinical Science | 1984

CRITICAL-EVALUATION OF THE SOURCE OF HEMORRHAGE IN MASSIVELY BLEEDING GASTRIC-ULCERS

Jerry P. O'Sullivan; C.P. Swain; S. G. Bown; P.R. Salmon; J.S. Kirkham; T.C. Northfield


British Journal of Surgery | 1982

CONTROLLED TRIAL OF ARGON-LASER PHOTO-COAGULATION IN BLEEDING PEPTIC-ULCERS

C.P. Swain; S. G. Bown; D.W. Storey; P.R. Salmon; J.S. Kirkham; K.B. Saunders; T.C. Northfield

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S. G. Bown

University College Hospital

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P.R. Salmon

University College Hospital

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C.P. Swain

University College Hospital

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J.S. Kirkham

University College Hospital

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C. Paul Swain

University College Hospital

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J. Squire Kirkham

University College Hospital

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Timothy Noel Mills

University College Hospital

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Cp Swain

University College Hospital

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D.W. Storey

University College Hospital

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