The immunogenicity of human cardiac valve allografts in vitro and in vivo

Allogeneic transplantation has become an accepted method for the replacement of diseased organs and tissues. The concept of cardiac valve transplantation for the replacement of semilunar valves was introduced by Lam et al in 1952'. In about 1960 the first human cardiac valve allografts were implanted,,3, Human donor valves have become a good alternative for other valve substitutes (porcine valve prostheses and mechanical valves) because of their superior hemodynamic performance and the absence of post-operative thrombosis and thromboembolism. Further, these valves are relatively resistant to endocarditis and recipients of human donor valves do not require anticoagulant therapy. At this moment, the valve allografts are stored at heart valve banks. In 1995, 68 heart valve banks were known world-wide'. Before the introduction of cryopreservation techniques, human valve allografts were stored at 4"C in a nutrient medium containing an antibiotic solution, with a maximum storage time of 6 weeks5 ". These antibiotic-sterilized, "fresh wet-stored" allografts showed a better medium-term (7-10 years) clinical performance than glutaraldehyde-treated human valves"'. Alternative storage techniques (freeze-drying, irradiation) resulted in a shorter long-term graft survival compared to mechanical valves"" and a higher incidence of cusp rupture". The introduction of cryopreservation procedures offered long-term storage and improved the availability of the valves

Doppler colour flow imaging of fetal intracerebral arteries relative to fetal behavioural states in normal pregnancy

In 14 normally developing term fetuses, the relationship between the blood flow velocity waveforms at cerebral arterial level (internal carotid artery, anterior, middle and posterior cerebral artery) and fetal behavioural states was studied using Doppler colour flow imaging. Behavioural state dependent changes in absolute flow velocities occurred in all vessels, except for the middle cerebral artery. These changes suggest preferential blood flow to the left heart resulting in increased flow to the cerebrum during fetal behavioural state 2F (active sleep) when compared with fetal behavioural state 1F (quiet sleep). The middle cerebral artery supplies the neocerebrum. This developing part of the cerebrum does not seem to take part in the regulation of fetal behaviour. In the internal carotid artery, an inverse relationship between peak systolic velocity and fetal heart rate could be established, which can be explained by a shorter rapid filling phase at raised fetal heart rate according to the Frank-Starling Law

Supplementary data for: Missed Diagnoses and Health Problems in Adults With Prader-Willi Syndrome: Recommendations for Screening and Treatment

Context: Prader-Willi syndrome (PWS) is a complex hypothalamic disorder, combining hyperphagia, hypotonia, intellectual disability, and pituitary hormone deficiencies. Annual mortality of patients with PWS is high (3%). In half of the patients, the cause of death is obesity related and/or of cardiopulmonary origin. Health problems leading to this increased mortality often remain undetected due to the complexity and rareness of the syndrome. Objective: To assess the prevalence of health problems in adults with PWS retrospectively. Patients, Design, and Setting: We systematically screened 115 PWS adults for undiagnosed health problems. All patients visited the multidisciplinary outpatient clinic for rare endocrine syndromes at the Erasmus University Medical Center, Rotterdam, Netherlands. We collected the results of medical questionnaires, interviews, physical xaminations, biochemical measurements, polygraphy, polysomnography, and radiology. Main outcome measures: Presence or absence of endocrine and nonendocrine comorbidities in relation to living situation, body mass index, genotype, and demographic factors. Results: Seventy patients (61%) had undiagnosed health problems, while 1 in every 4 patients had multiple undiagnosed health problems simultaneously. All males and 93% of females had hypogonadism, 74% had scoliosis, 18% had hypertension, 19% had hypercholesterolemia, 17% had type 2 diabetes mellitus, and 17% had hypothyroidism. Unfavorable lifestyles were common: 22% exercised too little (according to PWS criteria) and 37% did not see a dietitian. Conclusions: Systematic screening revealed many undiagnosed health problems in PWS adults. Based on patient characteristics, we provide an algorithm for diagnostics and treatment, with the aim to prevent early complications and reduce mortality in this vulnerable patient group

Missed diagnoses and health problems in adults with prader-willi syndrome: Recommendations for screening and treatment

Context: Prader-Willi syndrome (PWS) is a complex hypothalamic disorder, combining hyperphagia, hypotonia, intellectual disability, and pituitary hormone deficiencies. Annual mortality of patients with PWS is high (3%). In half of the patients, the cause of death is obesity related and/or of cardiopulmonary origin. Health problems leading to this increased mortality often remain undetected due to the complexity and rareness of the syndrome. Objective: To assess the prevalence of health problems in adults with PWS retrospectively. Patients, Design, and Setting: We systematically screened 115 PWS adults for undiagnosed health problems. All patients visited the multidisciplinary outpatient clinic for rare endocrine syndromes at the Erasmus University Medical Center, Rotterdam, Netherlands. We collected the results of medical questionnaires, interviews, physical xaminations, biochemical measurements, polygraphy, polysomnography, and radiology. Main outcome measures: Presence or absence of endocrine and nonendocrine comorbidities in relation to living situation, body mass index, genotype, and demographic factors. Results: Seventy patients (61%) had undiagnosed health problems, while 1 in every 4 patients had multiple undiagnosed health problems simultaneously. All males and 93% of females had hypogonadism, 74% had scoliosis, 18% had hypertension, 19% had hypercholesterolemia, 17% had type 2 diabetes mellitus, and 17% had hypothyroidism. Unfavorable lifestyles were common: 22% exercised too little (according to PWS criteria) and 37% did not see a dietitian. Conclusions: Systematic screening revealed many undiagnosed health problems in PWS adults. Based on patient characteristics, we provide an algorithm for diagnostics and treatment, with the aim to prevent early complications and reduce mortality in this vulnerable patient group