Elimination of rabies from red foxes in eastern Ontario.

The province of Ontario (Canada) reported more laboratory confirmed rabid animals than any other state or province in Canada or the USA from 1958-91, with the exception of 1960-62. More than 95% of those cases occurred in the southern 10% of Ontario (approximately 100,000 km2), the region with the highest human population density and greatest agricultural activity. Rabies posed an expensive threat to human health and significant costs to the agricultural economy. The rabies variant originated in arctic foxes: the main vector in southern Ontario was the red fox (Vulpes vulpes), with lesser involvement of the striped skunk (Mephitis mephitis). The Ontario Ministry of Natural Resources began a 5 yr experiment in 1989 to eliminate terrestrial rabies from a approximately 30,000 km2 study area in the eastern end of southern Ontario. Baits containing oral rabies vaccine were dropped annually in the study area at a density of 20 baits/km2 from 1989-95. That continued 2 yr beyond the original 5 yr plan. The experiment was successful in eliminating the arctic fox variant of rabies from the whole area. In the 1980's, an average of 235 rabid foxes per year were reported in the study area. None have been reported since 1993. Cases of fox rabies in other species also disappeared. In 1995, the last bovine and companion animal cases were reported and in 1996 the last rabid skunk occurred. Only bat variants of rabies were present until 1999, when the raccoon variant entered from New York (USA). The success of this experiment led to an expansion of the program to all of southern Ontario in 1994. Persistence of terrestrial rabies, and ease of elimination, appeared to vary geographically, and probably over time. Ecological factors which enhance or reduce the long term survival of rabies in wild foxes are poorly understood.

Limb salvage in poor-risk patients using transluminal angioplasty.

We performed percutaneous transluminal angioplasty (PTA) in 97 limbs of 86 patients with end-stage occlusive disease in whom vascular reconstruction was not possible. Most patients required dilation of long-segment occlusions and/or multiple lesions. Angiographic appearance was improved in 87 limbs of 78 patients (90%). Ankle-brachial pressure index increased from 0.40 +/- 0.03 to 0.64 +/- 0.03, and increased more than 0.15 in 63% of the limbs. Major amputation was required in 19 of the 87 limbs (22%) following PTA. The incidence of restenosis was 19% at three months, 42% at six months, and 57% at one year. Repeated PTA successfully maintained vascular patency in ten limbs, and four patients have since had successful distal bypass. Two limbs that initially improved needed amputation four to 19 months after dilatation. Follow-up ranged from one to 45 months; overall limb salvage rate was 76%. Thus PTA can enhance limb salvage in poor-risk patients with end-stage disease.

Selective infusion of streptokinase for arterial thrombosis.

We have treated 13 patients with limb-threatening ischemia caused by acute arterial thrombosis with selective arterial infusion of streptokinase. The indications for thrombolytic therapy included medical contraindication to surgery, surgically inaccessible thrombi, arterial thrombosis following percutaneous transluminal angioplasty, and thrombosed distal arterial bypass. Patients were evaluated with arteriography, Doppler segmental arterial pressure studies, and coagulation profile. Objective evidence of complete or partial thrombolysis was demonstrated in 11 of the 13 patients (85%). Treatment after thrombolytic therapy included percutaneous transluminal angioplasty in six patients and distal bypass in two patients. Of five patients who had received no additional treatment, three required amputation. Overall limb salvage was achieved in 10 of the 13 patients. The most serious complications were puncture site bleeding in five patients, acute renal failure in one patient, and retroperitoneal hemorrhage in another patient. Bleeding was more frequent in patients with decreased serum fibrinogen levels. Although lysis of acute arterial thrombi can be achieved, thrombolytic therapy alone will allow limb salvage in only a few patients. Selective thrombolytic therapy with streptokinase must be used with caution and is associated with serious complications.

Primary pulmonary Hodgin's disease: a case report.

A case of Hodgkin's disease occurred with pulmonary involvement as the initial feature. The disease was initially seen clinically and roentgenographically as a diffuse pulmonary infiltrate. To our knowledge, the pattern of diffuse pneumonic involvement without intrathoracic lymphadenopathy at presentation has been reported only in one other case. Differentiation of this diffuse pneumonic pattern of primary pulmonary Hodgkin's disease from the more common pattern of a focal mass or infiltrate is important in considering appropriate therapy.

Early diagnosis of breast cancer: experience in a consultant breast clinic.

Of 2839 women referred to a consultant breast clinic for clinical, mammographic and thermographic examination, 480 underwent biopsy and 126 were found to have cancer. Ten percent of the tumours were occult and were classified as very early biologic disease; they were identified by routine mammography in women whose breasts were clinically normal. Biopsy of solid mass lesions non-suspicious on mammography identified 20% of the cancers; half these lesions, classified as early biologic disease, were discovered by doctors at routine annual clinical breast examination, though the earliest cancers were detected by women who were confident and competent in monthly self-examination of the breasts. Biopsy of solid mass lesions suspicious on mammography identified 70% of the cancers; these were classified as late biologic disease. Skin or nipple dimpling or retraction was evident in two thirds of the patients; their lesions seemed to be later biologically than the lesions of the patients without clinical signs, and 75% had discovered the lesions themselves accidentally.