How Far Shall We Go in the Predonation Selection of Blood Donors to Safeguard Patients for Blood-Transfusion-Related Infections?: Editorial

American trypanosomiasis (Chagas' disease) can be transmitted by blood transfusion. For almost 40 years, this transmission has been limited to Latin America, but recently, three cases have been reported in the USA and Canada. With increasing emigration to North America and Europe, Chagas' disease may be introduced to the Northern hemisphere by transfusion of blood from carriers. This review will focus on the discovery, biology and antigenic profile of Trypanosoma cruzi (the aetiological agent of Chagas' disease), including the invertebrate vectors, animal reservoirs and transmission to humans, with special reference to blood transfusion. Finally, diagnostic tests and prophylactic measures for the prevention of Chagas' disease will be discussed.     

Transmission of herpes simplex during CPR training

Instruction in cardiopulmonary resuscitation (CPR) has become a standard part of training for medical personnel and is widely recommended for the lay public. We present a case report of two women, one of whom contracted herpes labialis and one of whom contracted ocular herpes simultaneously after participating as partners in a CPR training course. This case suggests that added precautions against the transmission of infectious disease should be taken by screening participants in CPR courses for signs of respiratory, oral, or facial cutaneous disease. In addition, this case underscores the crucial importance of adequately disinfecting mannequins between users and between training sessions. Specific recommendations are made.     

Adverse drug effects and the controlled clinical trial

Summary The controlled clinical triad is designed not to discover new drug effects, but to verify those effects, about which prior knowledge exists adequate for formulating exact null hypotheses. Therapeutic effects always meet this requirement. The question of a drug's clinical toxicity is essentially vague and open-ended and, therefore, ineligible for being fully answered by controlled trial. It can examine only those adverse drug effects which are predicted or anticipated, which occur with a certain frequency compatible with a practical trial size, and which do not pose ethical restrictions to human experimentation. Most toxic drug effects must be assessed empirically, i. e., by incompletely controlled observation or survey of events as they happen during ordinary drug use. This does not mean arbitrary collection of isolated data, but requires purposeful, systematic and coordinated procedures. Observational evidence is circumstantial and disputable from a strictly scientific viewpoint. Nevertheless, if observational data satisfy certain criteria, they contribute to decisions which are reasonable and practically useful by minimizing the risks for patients from adverse drug effects.     

Intermittent maple syrup urine disease in a 12-year-old boy: clinical aspects, diagnosis and treatment

A variant form of maple syrup urine disease (grade II) in a twelve year old boy is reported. The clinical picture was characterized by seizure-like episodes of confusion and intermittent ataxia. The diagnosis was made by showing an increased excretion of branched-chain alpha-hydroxy acids as well as evaluated plasma concentrations of the branched-chain aminoacids and alpha-ketoacids. There was a decrease of leucine degradation in cultured fibroblasts to 5 to 6% of normal. The treatment with thiamine-hydrochlorid remained without any clinical or biochemical effect in our patient. Further neurologic symptoms during acute episodes of vomiting could be avoided by dietary protein restriction and early parenteral glucose supplementation.     

Transplacental passage of vancomycin in the ex vivo human perfusion model

OBJECTIVES: To determine maternal-fetal transplacental passage of vancomycin in the ex vivo human placental perfusion model. METHODS: Six term placentas were collected immediately after delivery and perfused with physiologic medium using the single cotyledon perfusion system. Vancomycin was added to the maternal medium and perfused through the maternal circulation of the cotyledon. Over a 1-h period in an open system, samples of the perfusate were collected at defined intervals from the fetal venous catheter and from the maternal effluence to assess vancomycin transfer. Thereafter, the system was closed for 1-5 h to establish accumulation. Transport fraction and clearance indexes were calculated by perfusing antipyrine 14C (positive control). Vancomycin was estimated by high pressure liquid chromatography and antipyrine 14C concentration was determined by liquid scintillation. RESULTS: Mean vancomycin maternal peak and trough concentrations ranged from 30.0 to 51.5 microg/ml and 7.7 to 16.4 microg/ml, respectively. Clearance indexes were minimal with a mean peak range of 0.000-0.080 and a mean trough range of 0.00-0.17. For each placenta, transport fraction for antipyrine 14C was > 1.85 with a single pass of > 40%. No accumulation of vancomycin was noted when the system was closed for 1-5 h. The mean peak clearance index was zero after perfusing the placenta for up to 5 h with 35.8 microg/ml of vancomycin. CONCLUSION: Transplacental passage of vancomycin was minimal in the ex vivo human placental perfusion model, with no detectable accumulation.