The case for selective re-issuance of medical certificates to allow pilots who have received a heart transplant to resume flying.

BACKGROUND: Cardiac transplant recipients have been regarded as not medically fit to fly an airplane. Recently, the Federal Aviation Administration decided to re-examine this policy and, in response, this study was undertaken to determine the risk of death from any cause and sudden-onset death in heart transplant recipients during the 12 months after an annual evaluation. METHODS: Of 6,510 patients undergoing primary orthotopic cardiac transplantation enrolled in the Cardiac Transplant Research Database (CTRD), 4,978 patients survived for at least 1 year and formed the basis of this study. Risk factors for death from any causes and sudden-onset death (a composite of causes of death that could conceivably result in a pilot's incapacitation) were determined during the 12-month period after an anniversary evaluation. Patients were re-entered into the analysis at each evaluation, resulting in a total of 23,575 anniversary evaluations. RESULTS: The presence of coronary allograft vasculopathy (CAV), left ventricular systolic dysfunction, history of rejection, malignancy, infection and pre-transplant insulin-dependent diabetes were associated with an increased risk of death from any cause and sudden-onset death during the 12-month period after an evaluation. Based on the absence of these risk factors, a group of heart transplant recipients could be defined with a 12-month risk of death from any cause of 1.0% and of sudden-onset death of 0.3% (which is identical to the mortality rate of a matched population from the U.S. life-table). CONCLUSION: Using these identified risk factors, a group of heart transplant recipients can be defined that are potentially medically certifiable to fly without compromising aviation safety.     

Acute calcific periarthritis in scleroderma.

Three patients with limited cutaneous scleroderma (CREST syndrome) and acute calcific periarthritis are presented. "Chalky" bursal effusion in one patient demonstrated masses of calcium hydroxyapatite crystals. In contrast to idiopathic acute calcific periarthritis, resorption of periarticular calcifications after resolution of acute attacks occurs both less frequently and incompletely in scleroderma associated acute calcific periarthritis.     

Novel fluorescent compound (DDP) in calf, rabbit, and human articular cartilage and synovial fluid

OBJECTIVE: To investigate the presence of and quantify 2,6-dimethyldifuro-8-pyrone (DDP), a novel fluorescent compound identified as in various calf, rabbit, and human tissue/fluid samples, to determine the DDP level in articular cartilage (AC) laminae, and to investigate the changes in cartilage DDP content with cartilage maturation. METHODS: Samples were obtained from calf (< 2 years), rabbit (< 2 weeks to 2 years) or human AC and synovial fluid (SF) as well as other non-cartilaginous tissues. SF and tissue samples were hydrolyzed with 6 M HCl (24 hours at 110 degrees C), lyophilized, and dissolved in HPLC mobile phase. DDP and collagen crosslink peaks were measured using a fluorescence detector at excitation and emission wavelengths of 295 and 395 nm, respectively. RESULTS: DDP was detected from calf metacarpophalangeal joint AC (362 +/- 48 pmol/mg dry weight), SF (4.5 +/- 0.3 pmol/microl SF), and intervertebral disc (24 +/- 4 pmol/mg). DDP was not detected in calf ligament, tendon, bone, ocular lens, cornea, or elastic cartilage. The DDP amount was greater in mid-deep cartilage lamina (448 +/- 63 pmol/mg) than superficial-mid lamina (129 +/- 52 pmol/mg) (p = 0.008). DDP level decreased with maturation in rabbit knee joint AC from 185 +/- 40 (< 2 weeks) to 27 +/- 3 (2 years) pmol/mg dry weight. DDP was not detected in adult rabbit ligament, tendon, meniscus, or bone. DDP was detected in human knee joint AC and SF. The DDP level in osteoarthritic lesions was present in lower concentrations (range: 0 to 96 pmol/mg dried AC) compared to intact AC (range: 63 to 236 pmol/mg) of the same knee. CONCLUSION: DDP is a hyaline cartilage specific compound present in all articular cartilage samples from various articulating joints/animal species. DDP level increases with AC depth and decreases with cartilage maturation. DDP is a potential indicator of cartilage metabolism during normal growth, ageing, and cartilage disease.     

Transesophageal study of infant supraventricular tachycardia: electrophysiologic characteristics

Programmed electrical stimulation of the heart to initiate and terminate tachycardia and analysis of the temporal relation between ventricular and atrial activation during tachycardia have been useful in the evaluation of supraventricular tachycardia (SVT). Such techniques have rarely been applied to evaluate infants with SVT. We used a silicone rubber-coated bipolar electrode catheter (15 or 22 mm interelectrode spacing), positioned in the esophagus, for electrical stimulation of the heart and recording of electrograms for the evaluation of 14 infants aged 1 to 84 days with SVT. Three infants had electrocardiographic features of Wolff-Parkinson-White syndrome, and no infant had other manifestations of congenital heart disease. Tachycardia cycle lengths ranged from 180 to 295 ms and ventriculoatrial intervals recorded from the esophagus were 80 to 220 ms. In 12 infants, transesophageal atrial stimulation was used to terminate and initiate SVT using stimuli of 9.9 ms and 10 to 20 mA. Initiation and termination of SVT by electrical stimulation suggest that SVT in infants is due to reentry, and the presence of ventriculoatrial intervals greater than 70 ms further suggests that accessory atrioventricular connections (usually concealed) constitute a portion of the reentry circuit.     

Sellar enlargement with hyperprolactinemia and a Rathke's pouch cyst

A woman with secondary amenorrhea was found to have hyperprolactinemia without clinical galactorrhea. Radiological findings of an enlarged sella turcica with displacement of the pituitary stalk were considered consistent with a prolactin macroadenoma. Treatment with bromocriptine corrected the amenorrhea and hyperprolactinemia, and the patient inadvertently became pregnant. However, no complications to the mother or fetus occurred during pregnancy or postpartum. On transsphenoidal surgery three months postpartum, the unexpected presence of a large Rathke's pouch cyst with a microadenomatous or nodular hyperplasia type of prolactin-secreting tumor was observed to account for the preoperative clinical and radiological findings.     

Recurrent colocolic intussusception in a child with hereditary angioneurotic edema: reduction by air enema

The authors discuss a case of hereditary angioneurotic edema in a child presenting with recurrent episodes of colocolic intussusception, each successfully reduced by air enema. Although additional manifestations of vasogenic edema are potential risks of the procedure, these were not encountered.     

Synovial fluid analysis--another look at the mucin clot test

We analyzed the relationship between the mucin clot test and the synovial fluid (SF) leukocyte count in osteoarthritis, rheumatoid arthritis (RA), gout, and calcium pyrophosphate dihydrate crystal deposition disease. Except for RA there was no statistically significant relationship between white count and a tight mucin determination within the disease categories. For low (2 X 10(9) cells/l or less) leukocyte counts, the crystal induced arthropathies had a significantly greater proportion showing a tight reaction than found in the osteoarthritic and rheumatoid fluids. We propose that mucin clot determinations may reflect synovial membrane activity rather than SF leukocyte counts.     

Pyrophosphate, phosphate ion interaction: effects on calcium pyrophosphate and calcium hydroxyapatite crystal formation in aqueous solutions

The relationship between ambient ionic conditions that favor pyrophosphate (PPi) versus phosphate (Pi) biomineralization is important to understanding the pathogenesis of chondrocalcinosis. We studied aqueous solutions at pH 7.4, 37 degrees C, [Na+] = 140 mM, [Mg+ +] = 0.5 mM, [Ca+ +] = 1.0 or 1.5 mM over a range of pyrophosphate and phosphate concentrations to determine the effect of different ambient concentrations and ratios of Pi/PPi on calcium pyrophosphate dihydrate (CPPD) and calcium hydroxyapatite (HA) crystal formation. We found that the Pi/PPi ratio is an extremely important determinant of the crystal product formed. At low [Pi], CPPD crystal formation is partially inhibited by Pi; at higher [Pi], calcium pyrophosphate, calcium phosphate and calcium pyrophosphate-phosphate complexes amorphous to x-ray diffraction are formed; whereas at still higher [Pi], HA crystal formation partially inhibited by PPi. We conclude that CPPD forms when the ratio [Pi]/[PPi] less than 3 and HA forms when [Pi]/[PPi] greater than 100.