Xenotransplantation: A potential solution to the critical organ donor shortage.

The success of allotransplantation as a treatment for end-stage organ failure has resulted in the need for an increasing number of organ donors. Attempts to meet this need include the use of organs from living related and unrelated donors, financial or other incentives for the donor family, and even the reuse of transplanted organs. Despite these initiatives, the supply of organs for transplantation still falls far short of the demand, as evidenced by longer waiting times for transplantation and decreasing transplantation rates. Even if Canada were able to increase its organ donor rate to that of Spain (40 to 50/million), where organ donation is governed by 'presumed consent' legislation, this would not alleviate the problem of donor shortage. Interest in xenotransplantation stems from the need to overcome this increasingly severe shortage of human organs. Indeed, some argue that xenotransplantation is the only potential way of addressing this shortage. As immunological barriers to xenotransplantation are better understood, those hurdles are being addressed through genetic engineering of donor animals and the development of new drug therapies. However, before xenotransplantation can be fully implemented, both the scientific/medical communities and the general public must seriously consider and attempt to resolve the many complex ethical, social and economic issues that it presents.

Induction of airway mucus production By T helper 2 (Th2) cells: a critical role for interleukin 4 in cell recruitment but not mucus production.

Airway inflammation is believed to stimulate mucus production in asthmatic patients. Increased mucus secretion is an important clinical symptom and contributes to airway obstruction in asthma. Activated CD4 Th1 and Th2 cells have both been identified in airway biopsies of asthmatics but their role in mucus production is not clear. Using CD4 T cells from mice transgenic for the OVA-specific TCR, we studied the role of Th1 and Th2 cells in airway inflammation and mucus production. Airway inflammation induced by Th2 cells was comprised of eosinophils and lymphocytes; features found in asthmatic patients. Additionally, there was a marked increase in mucus production in mice that received Th2 cells and inhaled OVA, but not in mice that received Th1 cells. However, OVA-specific Th2 cells from IL-4-deficient mice were not recruited to the lung and did not induce mucus production. When this defect in homing was overcome by administration of TNF-alpha, IL-4 -/- Th2 cells induced mucus as effectively as IL-4 +/+ Th2 cells. These studies establish a role for Th2 cells in mucus production and dissect the effector functions of IL-4 in these processes. These data suggest that IL-4 is crucial for Th2 cell recruitment to the lung and for induction of inflammation, but has no direct role in mucus production.

[Electrocardiographic studies of patients with acute hellebore (Veratrum album) poisoning]. / Elektrokardiografski prouchvaniia pri bolni s ostro otraviane s chemerika (Veratrum album).

In 12 patients, 20 to 80 years of age, 6 men and 6 women, with acute hellebore (Veratrum album) intoxication the electrocardiographic changes were studied. In 10 of them a characteristic ECG pattern was found: sinus bradycardia 38-40/m, shortening of the interval PQ up to 0.12-0.08 s and QTc up to 0.36-0.32 s, slow intraventricular conduction--transitory right and incomplete left bundle-branch block, rhythm disorders--atrial and substitutional ventricular extrasystoles, nodal rhythm (I patient), disturbed ventricular repolarization--depression of ST-segment, low and (or) pointed T waves. The authors are of the opinion that the bradycardia is due to a reflexively increased vagal tonus but the other changes of the ECG are caused by the direct toxic action of the hellebore alkaloids on the myocardium. This suggestion is supported by the fact that atropine corrects the bradycardia but not the other pathological changes of the ECG. They are beneficially influenced by the fast elimination of the toxins and the application of cardiotropic means--atriphos, cocarboxylase, vitamins of the group B.

[Treatment of patients with acute digitalis poisoning by charcoal hemoperfusion]. / Lechenie na bolni s ostri otravianiia s digitalisovi preparati po metoda na karbokhemoperfuziiata.

10 patients with acute digitalis intoxication were treated by charcoal hemoperfusion. The patients had taken high toxic and lethal doses of digitalis drugs: 3 patients had taken 10 mg of (digitalin, 2 patients--7.5 mg of digoxin, 5 patients--10-25 mg of isolanid (ceglunat). 4 of the patients were with a heart disease and the other 6 patients did not have any heart disease. The charcoal hemoperfusion lasted 4 to 6 hours, in one female patient--2 hours. The mean minute volume was 100 to 150 ml/min, in some patients it reached up to 200 ml/min. The digoxin blood concentration was determined before and after the hemoperfusion in 4 patients and a decrease of 49% was found. 9 patients fully recovered and only one patient, a 70 years old women, who had not received antiarrhythmic treatment, died. Good results were also achieved in digitalin intoxications determined by the clinical course and the electrocardiographic data. The overall estimation of the method is that it is efficient and should be applied to patients with acute digitalis intoxication, always in combination with antidote, antiarrhythmic and cardioprotective treatment.