Importance of open marine waters to the enrichment of total mercury and monomethylmercury in lichens in the Canadian High Arctic.

Caribou, which rely on lichens as forage, are a dietary source of monomethylmercury (MMHg) to many of Canada's Arctic Aboriginal people. However, little is understood about the sources of MMHg to lichens in the High Arctic. We quantified MMHg, total mercury (THg) and other chemical parameters (e.

Regeneration of Little Ice Age bryophytes emerging from a polar glacier with implications of totipotency in extreme environments.

Across the Canadian Arctic Archipelago, widespread ice retreat during the 20th century has sharply accelerated since 2004. In Sverdrup Pass, central Ellesmere Island, rapid glacier retreat is exposing intact plant communities whose radiocarbon dates demonstrate entombment during the Little Ice Age (1550-1850 AD). The exhumed bryophyte assemblages have exceptional structural integrity (i.

Totally minimized extracorporeal circulation: an important benefit for coronary artery bypass grafting in Jehovah's witnesses.

Background: Jehovah's Witnesses who require cardiac surgery represent a challenge to the physician because of their refusal to accept blood transfusions. Because coronary artery bypass grafting (CABG) is performed by most surgeons under cardiopulmonary bypass (CPB), which has potentially deleterious effects on hemostasis, we used a new concept called minimal extracorporeal circulation (MECC). MECC includes heparin-coated tubing, a centrifugal pump, and an oxygenator.

[Campylobacter fetus subspecies fetus endoaortitis on a Bentall tube prosthesis. Apropos of a case].

Campylobacter fetus is a rare cause of endocarditis and endoaortitis: the authors believe this to be the second reported case of infection of an intracardiac prosthesis. The patient was a man who had already undergone replacement of the aortic valve and ascending aorta, and a gastrectomy, which were predisposing factors. The portal of entry was not found.

[Extracorporeal circulation in acute ischemia of the lower limb with late detection].

The authors report a case of acute limb ischemia in a 19 years old patient seen at 9 hours of the injury. They describe a technique of "washing-reperfusion" by a cardio-pulmonary limb bypass (CPLB). Blood pH and kaliema measurements during CPLB were noted.

[Coronary artery bypass with bovine internal mammary artery graft].

Ten of 1,025 patients undergoing coronary bypass surgery received one or two bovine internal mammary artery grafts. Surgery consisted in quadruple coronary bypass in 1 case, triple coronary bypass in 3 cases and double coronary bypass in 6 cases using 4 autologous saphenous vein grafts, 6 autologous internal mammary artery grafts and 13 bovine internal mammary artery grafts. It was necessary to use bovine internal mammary artery grafts because of total bilateral venous stripping in 5 patients, diffuse, bilateral varicose veins in 4 patients and because of the insufficient length of the vein in 1 patient.

[Repair of post-infarction interventricular communication in a 81-year-old patient].

Post-infarction interventricular fistula (IVF) is a complication with a poor prognosis, particularly when it occurs very early after myocardial necrosis, when it is wide in diameter and even more so if it is at a posterior site, and if there are associated lesions which require surgery. An operation is often considered as contraindicated in cases where the patient is elderly. The authors report on the case of an 81-year-old diabetic patient operated for a wide post-infarctus posterior IVF and aorto-coronary artery bypass surgery.

[Coronary artery bypass using bovine internal mammary artery].

Among 760 patients who underwent coronary artery bypass graft (CABG) 8 received one or two bovine internal mammary artery grafts. The surgical procedures were 4, 3 and 3 CABG respectively in 1, 3 and 4 cases with greater saphenous veins in 4 cases, internal mammary artery in 4 cases and bovine internal mammary artery in 11 cases. The 3 mm bioflow grafts were used to revascularize the left coronary artery in 6 cases (to the left anterior descending, circumflex artery) and the right coronary artery in 5 cases.

[Reoperation on valve bioprostheses. Apropos of 64 cases].

Sixty-four patients with one or more bioprostheses were reoperated between 1970 and 1982. Reoperation was performed for degenerative lesions in cases (48%), for aseptic periprosthetic leaks in 18 cases (28%), for infectious lesions in 13 cases (21%) and for thrombosis in 2 cases (3%). Degenerative and infectious lesions were commoner in aortic bioprostheses whilst periprosthetic leaks were commoner in mitral bioprostheses.

[Open approach to the subclavian vein for permanent cardiac stimulation].

In 97.5% of 562 successive attempts, puncture of the subclavian vein to introduce permanent pacemaker electrodes was made easier and safer by the incisional technique described in this report. The very low incidence (0.

[Severe postoperative heart blocks appearing late. 16 cases].

Sixteen patients, aged 4 to 42 years, operated for congenital heart disease, presented, months or years after surgery, complete atrioventricular (11 cases) or sinoatrial block (5 cases). Six patients had transient complete atrioventricular block in the immediate postoperative period, the maximum duration of which was less than 30 days. The late postoperative period was defined as at least 6 months after surgery.

[Removal of wasted endocavitary pacemaker electrodes by the epigastric route without cardiopulmonary bypass (author's transl)].

Wasted, embedded and infected endocavitary pacemaker electrodes responsible for severe septicaemia were removed on three occasions, using an original technique. The heart was approached through a subxyphoid or epigastric incision, and the right ventricule was entered through a short opening in its diaphragmatic surface. The cardiac incision was comprised within a U-shaped suture resting on two teflon felter strips.

Computed tomography versus aortography in diagnosis of aortic dissection.

The use of computed tomography (CT) versus aortography is evaluated in a limited study of 17 cases of aortic dissection (AD). With the constraints of the present state of the technology and lack of availability of CT scanners at some centers, aortography remains the premier and often the only diagnostic test to choose in an emergency. CT, however, may be an asset in the diagnosis of AD when: (1) atypical or misleading clinical presentations are evident that do not require aortography; (2) aortography is contraindicated in a weakened patient, when there is no emergency; (3) aortography is a risk while there is a strong suggestion of AD; (4) patency of a false channel must be confirmed.

[Auriculo-ventricular block and pregnancy].

20 cases of pregnancy in women with complete atrioventricular block (AVB) (12 patients) or with permanent pacemakers (8 patients) were observed in a French cooperative series and compared with I30 previously reported cases. Most patients were asymptomatic but an increase in the number of syncopes during gestation might be observed : 4 out of 12 in our series. Although AVB remains functionally latent during pregnancy, regular cardio-obstetric follow-up is advised.

[Disinsertion of the left innominate vein during median vertical sternotomy (author's transl)].

The left innominate vein may be torn during median vertical sternotomy. This tear may in fact be a disinsertion of the venous trunk from the superior vena cava. Repair of this disinsertion is difficult, with a risk of stenosis.

Surgery for aortic dissection: 53 operated cases with 32 in the acute phase.

53 cases of aortic dissections were operated on between 1961 and 1975 in the Service of Cardiovascular Surgery at the Broussais Hospital, Paris (Prof. Ch. Dubost).