Objective

To determine differences in the rates of growth, endocrine and calcium related abnormalities in the various thalassemia syndromes in North America with current therapy.

Methods

Medical history, physical examinations and blood and urine collections were obtained from patients with all thalassemia syndromes age 6 years and older in the Thalassemia Clinical Research Network.

Results

361 subjects, 49% male, mean age 23.2 years (range 6.1 to 75 years) were studied. Approximately 25% of children and adults, regardless of the thalassemia syndrome, had short stature. Overall growth in children was mildly affected. Final height was close to midparental height (z = -0.73 ± 1.24). Patients with beta thalassemia major (TM) had higher rates of hypogonadism, multiple endocrinopathies, worse hyperglycemia, subclinical hypoparathyroidism and hypercalciuria. Hypogonadism remained the most frequent endocrinopathy and was frequently under-treated. 12.8% of the subjects had 25 vitamin D concentrations less than 27nmol/L and 82% less than 75nmol/L, regardless of the thalassemia syndrome. Adolescents had lower 25 vitamin D levels than children and adults.

Conclusions

Compared to patients with other thalassemia syndromes, those with beta TM suffer from higher rates of multiple endocrinopathies, abnormal calcium metabolism and hypercalciuria. Vitamin D abnormalities are high among adolescents.

Background

It is becoming increasingly important for health professionals to have an understanding of health informatics. Education in this area must support not only undergraduate students but also the many workers who graduated before informatics education was available in the undergraduate program. To be successful, such a program must allow currently-employed students with significant work and family commitments to enroll.

Objectives

The aim was to successfully create and teach a distance program in health informatics for the New Zealand environment.

Methods

Our students are primarily health professionals in full time employment. About 50% are doctors, about 25% nurses, and the rest include dentists, physiotherapists, and medical managers. Course material was delivered via the World Wide Web and CD-ROM. Communication between students and faculty, both synchronous and asynchronous, was carried out via the Internet.

Results

We have designed and taught a postgraduate Diploma of Health Informatics program using the Internet as a major communication medium. The course has been running since July 1998 and the first 10 students graduated in July 2000. About 45 students are currently enrolled in the course; we have had a dropout rate of 15% and a failure rate of 5%. Comparable dropout figures are hard to obtain, but a recent review has suggested that failure-to-complete rates of 30% to 33% may be expected.

Conclusions

Internet technology has provided an exciting educational challenge and opportunity. Providing a web-based health informatics course has not been without its frustrations and problems, including software compatibility issues, bandwidth limitations, and the rapid change in software and hardware. Despite these challenges, the use of Internet technology has been interesting for both staff and students, and a worthwhile alternative for delivering educational material and advice to students working from their own homes.

The clinicopathologic effects of intravenously administered purified verocytotoxin 1 (VT1; Shiga-like toxin 1) in 2-kg male rabbits was studied. The 50% lethal dose was 0.2 micrograms of protein per kg of body weight (2 x 10(4) 50% cytotoxic doses per kg). The clinical features included nonbloody diarrhea and a progressive flaccid paresis, usually culminating in death. The histopathology was characterized by edema and hemorrhage in the mucosa and submucosa of the cecum and edema, hemorrhage, and neuronal necrosis in the brain and gray matter of the spinal cord. Thrombotic microangiopathy, the characteristic histopathologic renal lesion in the hemolytic-uremic syndrome, was also found to be the underlying lesion in verocytotoxemic rabbits. To determine the specific distribution of VT1 in rabbit tissues, purified 125I-labelled VT1 was administered intravenously to 20 rabbits (both immunologically naive and VT1-immune rabbits). The highest specific uptake of 125I-VT1 was in the spinal cord, brain, cecum, colon, and small bowel in unimmunized animals but in the liver, spleen, and lungs in immune animals. Immunofluorescent staining of cecal and spinal cord tissues after intravenous administration of VT1 showed evidence of specific vascular endothelial cell binding of the toxin. The striking correlation of the central nervous system and gastrointestinal localization of 125I-VT1 with the sites of known histopathology is consistent with direct toxin-mediated injury to these tissues, initiated by the specific binding of VT1 to the vascular endothelium. We conclude that the vascular damage induced by VT1 in affected rabbit tissues is similar to that seen in the kidneys and other tissues in patients with verocytotoxin-producing Escherichia coli-associated hemolytic-uremic syndrome. This suggests that although the rabbit model fails to replicate human hemolytic-uremic syndrome, it is useful for studying the pathogenesis of the vascular lesions in verocytotoxin-producing E. coli-associated diseases.

Images

The accurate assessment of patient compliance is especially crucial in evaluating the efficacy of a new treatment. Because of the problems associated with parenteral desferrioxamine, the development of a safe, effective, and convenient iron chelator is of high priority. The high morbidity and mortality associated with iron overload requires careful evaluation of the ability of any new agent to promote long term effective iron chelation. Patients' compliance with an orally available chelating agent, 1,2,-dimethyl-3-hydroxypyrid-4-one (L1), that has been demonstrated to induce in vivo iron excretion equivalent to that of desferrioxamine during supervised short term administration, was examined. Compliance was assessed in seven patients by patient interview, by daily diaries reviewed monthly with each patient, and with the use of the Medication Event Monitoring System (MEMS) standard pill bottles with microprocessors in the cap that record the timing and frequency of bottle openings. L1 was dispensed in MEMS containers to the patients, who, unaware of their significance, recorded compliance using a daily diary. Overall compliance rate (% of prescribed doses taken) measured by MEMS was 88.7 +/- 6.8%. When 'doubling of doses' was accounted for, significantly poorer compliance with L1 was noted by MEMS (91.7 +/- 7.4%) than by patients' diaries (95.7 +/- 5.2%). There was no significant difference in patient compliance recorded between the first and last 30 day period of drug administration. MEMS can eliminate the confounding variable of erratic patient compliance in the evaluation of a new drug's efficacy. As MEMS cannot distinguish a missed dose from one doubled at the next bottle opening, the use of patient diaries is a useful adjunct to the accurate assessment of compliance and should be combined with the use of MEMS.

Images