RESUMO

We report the presence of basilar invagination, an unexpected and previously undescribed abnormality of the skull base, in 7 of 38 long-term survivors of multisystem Langerhans' cell histiocytosis. The abnormality is acquired, but its pathogenesis is uncertain.

Assuntos

RESUMO

Seventy-eight patients who had constitutional delay of growth and puberty were included in a retrospective study to determine whether, at the time of first evaluation, any predictive features could suggest final height outcome. Mean chronologic age was 14.3 years (range, 12 to 18 years), and all were either prepubertal or in an early stage of pubertal maturation (4 ml testicular volume). Initial mean (+/- SD) height standard deviation score was -2.74 (+/- 0.71); 85% had a relatively short spine compared with subischial leg length. Mean (+/- SD) growth rate was 4.8 (+/- 1.6) cm/year, and epiphyseal maturation was delayed by 2.4 (+/- 1) years. Sixteen boys were treated with a sustained-action preparation of testosterone (50 mg monthly for 3 to 4 months), six with oxandrolone (1.25 mg daily for a mean of 4 months), and one with both drugs in sequence. At final height attainment, 58% of the boys failed to achieve their full genetic potential; among the remaining 42%, only 0.7% attained a final height above corrected mid-parental height. The relative disproportion between the segments had no significant change at final height attainment. Regression analysis showed that final height impairment (the difference between mid-parental height and final height) was negatively influenced by standing height and growth velocity when initially evaluated and positively by the degree of segmental body proportion; that is, patients who were taller, were growing at a faster rate, and who had a major degree of segmental body disproportion with a short spine and long leg length attained a final height closer to their mid-parental height, irrespective of the degree of delayed epiphyseal maturation. Neither testosterone nor oxandrolone administered during early puberty modified final height attainment or segmental proportion. We conclude that a late onset in the timing of puberty seems to be deleterious to spinal growth and consequently to final height attainment. An alternative diagnosis should be sought among patients with features of constitutional delay of growth and puberty who do not have a significant degree of body disproportion. In these patients, as well as in those who are extremely short, who have a poor growth rate, or who have an unfavorable genetic potential, an alternative therapeutic approach may be required.

Assuntos

RESUMO

The pubertal growth spurt has been associated with changes of physiologic pulsatile growth hormone (GH) secretion, and abnormalities of the central regulation of GH release have been found by pharmacologic testing in patients with chronic renal failure. To assess the characteristics of GH pulsatility in chronic renal failure and their relationship to pubertal growth, we studied spontaneous nighttime GH plasma profiles in 80 patients (61 boys) aged 10 to 20 years receiving conservative treatment (n = 29) or dialysis (n = 18) or after renal transplantation (n = 33). Tanner genital stages 1 to 4 in boys and breast stages 1 to 3 in girls were represented. Growth hormone pulse analysis was performed by the PULSAR algorithm. Growth hormone concentration profiles were pulsatile in each patient. Growth hormone mean and baseline levels and pulse amplitudes were higher in patients receiving conservative or dialysis treatment than in patients who had undergone renal transplantation. Peak frequency was similar in all treatment groups in boys but higher in girls who had undergone transplantation than in girls receiving conservative or dialysis treatment. Growth hormone peak amplitude and mean levels were lowest in patients in late puberty. The physiologic elevation of GH amplitudes around midpuberty was observed in boys receiving conservative and dialysis treatment but not after transplantation. Growth hormone mean and baseline levels were positively correlated with plasma androgen levels in boys. Growth hormone peak amplitude was correlated with 6-month height velocity after transplantation but not in patients receiving conservative treatment or dialysis. A strong inverse relationship was observed between GH peak amplitude and corticosteroid dosage in patients undergoing transplantation. The lack of relationship between circulating GH levels and growth in patients receiving conservative or dialysis treatment is compatible with end-organ hyporesponsiveness to GH. Pubertal growth failure despite successful transplantation appears to be related to steroid-induced GH hyposecretion.

Assuntos

Assuntos

RESUMO

We tested the effect on energy balance of the partial substitution of medium-chain for long-chain triglycerides in the diet of growing low birth weight infants. Fifteen infants were studied in a randomized double-blind crossover clinical trial in which each infant was fed each of two formulas, which were of equal gross energy and protein content but differed in fat composition. The high medium-chain triglyceride (MCT) formula contained medium- and long-chain triglycerides in a weight/weight ratio of 46:54; in the low MCT formula the ratio was 4:96. The hypothesis tested was that under conditions of equal gross energy intake the two diets would differ in their digestible and metabolizable energy contents and would produce differences in the infants' rates of energy expenditure and energy storage. Gross energy intakes averaged 562 and 555 kJ/kg/day (134 and 133 kcal/kg/day) with the high and low MCT formulas, respectively. With each diet, coefficients of energy digestibility (0.93) and metabolizability (0.91) were identical; the rates of energy expenditure were 262 (high MCT) and 265 (low MCT) kJ/kg/day (63 kcal/kg/day for both diets), and of energy storage were 246 (high MCT) and 239 (low MCT) kJ/kg/day (59 and 57 kcal/day). These differences were not significant. There were also no significant differences between the two diets in coefficients of nitrogen retention (mean 0.70) or in rate of weight gain (mean 21.5 gm/kg/day). The use of high MCT content in infant formula neither provided a nutritional advantage in energy digestibility or metabolizability nor resulted in an increased rate of energy expenditure or of energy storage.

Assuntos