There is evidence of ongoing SIRS with concomitant CARS in critically ill patients with ARF, with higher levels of plasma IL-6, IL-8, and IL-10 in patients with ARF who die during hospitalization. Strategies to modulate inflammation must take into account the complex cytokine biology in patients with established ARF.

No abstract

Previous studies of episodic hormone secretion of the hypothalamic-pituitary-gonadal axis in normal men have produced conflicting results due to examinations of small cohorts of subjects or to limited sampling techniques. We evaluated gonadotropin and testosterone (T) secretory patterns in 20 normal men by sampling blood at 10-min intervals for luteinizing hormone (LH) and follicle-stimulating hormone (FSH). T concentrations were also analyzed at 20-min intervals in 10 subjects. A previously unappreciated spectrum of gonadotropin and T secretory patterns was observed in normal men. Both mean LH concentrations and mean LH pulse amplitudes varied fourfold between individuals. LH interpulse intervals varied from 30 to 480 min (mean 119 +/- 32). Results also suggested a relative refractory period at the level of the hypothalamus or pituitary. In three subjects, a striking nighttime accentuation of LH pulsations was noted. Through use of Fourier analysis, a diurnal variation in LH was observed in the population (P less than 0.02). Mean FSH levels showed marked variation between individual subjects, with discrete pulses rarely observed. No diurnal variation in FSH secretion was noted. Serum T concentrations determined at 6-h intervals ranged from 105 to 1,316 ng/dl between subjects. When T was measured at 20-min intervals, marked intermittent declines in the T concentrations to levels well below the normal range were observed in 3 of 10 subjects. T secretion was found to lag behind LH secretion by approximately 40 min (P less than 0.02).

Several lines of evidence indicate that hypothalamic-pituitary-gonadal activity varies among men with idiopathic hypogonadotropic hypogonadism (IHH). To test the hypothesis that a spectrum of abnormalities of GnRH secretion underlies the syndrome of IHH, we characterized the patterns of GnRH-induced gonadotropin secretion during periods of frequent sampling in 50 consecutive men with IHH and contrasted them with those in 20 normal men. The largest group of IHH patients (n = 42) had no detectable LH or FSH pulsations and could be categorized into 2 subsets according to the presence or absence of evidence of spontaneous puberty. The most severely affected subset (n = 32), who recalled no history of puberty, had testes with a mean volume of 3.3 +/- 0.5 (+/- SEM) ml, with a prepubertal appearance on biopsy, and often were anosmic (n = 17). The second subset of apulsatile IHH men (n = 10) had histories of partial or complete spontaneous sexual development with subsequent isolated loss of sexual function, testes with a mean volume of 13.3 +/- 1.9 ml (P less than 0.01 compared to the first subset), a pubertal or adult appearance of the testes on biopsy, and an intact sense of smell. In a second group of IHH patients (n = 3), LH was secreted predominantly in a nighttime pattern similar to that of normal children during early puberty. These men were aged 18-24 yr, had a mean testicular volume of 10.5 +/- 2.3 ml, pubertal changes on testicular biopsy, and an intact sense of smell. A third group of IHH men (n = 4) had LH pulses of abnormally low amplitude. Only one patient in this group had a history of spontaneous sexual development. The mean testicular volume of these patients was 5.6 +/- 1.9 ml, and the testes appeared prepubertal (n = 3) or pubertal (n = 1) on biopsy. In addition to these groups, another patient had apparent LH pulsations and nearly normal amplitude, but the LH was bioinactive and appeared to consist chiefly of alpha-subunit. Testing of other anterior pituitary hormone functions did not distinguish IHH men from normal men. However, those IHH patients with some evidence of endogenous GnRH secretion had higher basal and stimulated serum PRL levels than IHH men without such evidence (P less than 0.05), suggesting an influence of GnRH on PRL secretion.