Growth after intestinal transplant in children.

Intestinal transplantation has been more frequent in children with intestinal failure. However, the growth after intestinal transplantation has not been well documented. The demographics, transplant information, postoperative complications, heights, and weights were obtained retrospectively from medical records on 23 children who underwent intestinal transplantation. Z-scores were calculated from the STAT Growth-BP, based on Centers for Disease Control and Prevention growth chart (2000). Transplantations were performed between 1999 and 2004. Patient median age was 1.1 years (range 0.5 to 6.9 years). Twelve were boys and 11 girls. Seventeen children received multivisceral transplantations, one modified multivisceral transplantation, and five isolated intestinal transplantations. Baseline immunosuppression consisted of tacrolimus and corticosteroids. Daclizumab was used as induction agent in 18 patients; alemtuzumab, in five patients. Median pretransplant Z-scores were median -1.67 (n = 23) in weight, and median -3.36 (n = 21) in height. Pretransplant growth was significantly retarded. We analyzed significantly retarded patients with Z-score <-2.0. The change of weight Z-score from pretransplant was: 1.25 at 6 months (n = 11), 1.46 at 12 months (n = 10), and 2.21 at 24 months (n = 7). The change of height Z-score: 1.9 at 6 months (n = 16), 1.42 at 12 months (n = 13), and 1.51 at 24 months (n = 10). Z-score significantly improved (P < .002, ANOVA). Among the analyzed factors sex, age at transplant, length of stay, and rejection within 6 months, were not associated with catch-up growth. Children with retarded growth showed significant catch-up after successful intestinal transplantation.

Enhancement of spontaneous C3H/HeJ mammary tumorigenesis by long-term polyadenylic-polyuridylic acid therapy.

Female C3H/HeJ mice received weekly s.c. injections of 2 mg polyadenylic-polyuridylic acid. Therapy was initiated at either 2 or 9 months of age. In both cases, poly-adenylic-polyuridylic acid-treated animals developed the spontaneous mammary carcinoma associated with this strain more rapidly. Because the opposite result was formerly observed for AKR spontaneous leukemia, the data indicate the polyadenylic-polyuridylic acid has no generalized antineoplastic effect upon spontaneous tumors genetically associated with specific murine strains.

The age-dependent efficacy of polyadenylic-polyuridylic acid therapy upon the development of spontaneous leukemia in AKR mice.

The synthetic double-stranded polynucleotide, polyadenylic-polyuridylic acid, has been shown to increase the long-term survival of AKR mice. In order to determine whether this effect was age dependent, polyadenylic-polyuridylic acid was administered to AKR mice starting at 2, 4, 6, or 8 months of age. The best therapeutic effect was achieved when polyadenylic-polyuridylic acid treatments were begun at 2 months of age, and there was no beneficial effect when begun at 8 months of age.

The cholesterol side chain cleavage system of the rat adrenal cortex and its relationship to the circadian rhythm.

The adrenal mitochondrial cytochrome P450 systems were examined at the low and high points of the circadian rhythm in female rats maintained on a light cycle from 0600--1800 h. The rate of association of cholesterol with the cholesterol side chain cleavage form of cytochorme P450 (P450scc) was measured by light absorption spectrometry. Cholesterol binding to P450scc was as high in rats killed at the beginning of the dark period as it was in stressed rats at the beginning of the light period. Stressing rats at the beginning of the dark period did not result in a further increase in the rate of cholesterol association with P450scc despite a further increase in serum corticosterone levels. This suggests that other reactions of cholesterol metabolism in the adrenal cortex are contributing in a significant way to the increased rate of corticosteroidogenesis seen in the stressed animals.

Site of action of growth hormone on adrenocortical steroidogenesis in rats.

Studies were carried out to define the mechanism of action of growth hormone on adrenocortical steroidogenesis in hypophysectomized female rats. ACTH administration for 7 days increased corticosterone secretion in vivo and corticosterone production by adrenal tissue in vitro. Adrenal mitochondrial and microsomal cytochrome P-450 concentrations as well as the activities of cytochrome P-450-dependent enzymes (cholesterol sidechain cleavage, 11beta-hydroxylase, 21-hydroxylase) were also increased by ACTH. Administration of bovine growth hormone alone to hypophysectomized rats had no effect on any of the parameters evaluated. However, when given in combination with ACTH, growth hormone synergistically enhanced the effects of ACTH on cholesterol sidechain cleavage activity and corticosterone secretion. The magnitude of the pregnenolone-induced difference spectrum in adrenal mitochondria, indicative of cholesterol binding to cytochrome P-450, was also increased by growth hormone, but neither cytochrome P-450 content nor the activities of other steroidogenic enzymes were affected. The results indicate that growth hormone interacts with ACTH to promote corticosterone secretion by increasing the association of cholesterol with adrenal mitochondrial cytochrome P-450, thereby increasing the activity of cholesterol sidechain cleavage, the rate-limiting step in steroidogenesis.

Osmolality and potassium cause alterations in the volume of glomerulosa cells.

Alterations in extracellular osmolality have a powerful inverse effect on aldosterone secretion and potassium- and angiotensin-stimulated aldosterone secretion. Whether alterations in extracellular osmolality produced sustained changes in cell volume that may contribute to the regulation of aldosterone secretion is not known. Using dispersed bovine glomerulosa cells grown in primary culture, the effect of alterations in osmolality on cell volume, measured by the distribution of [14C]urea and [3H]inulin and videometric analysis of the surface area of glomerulosa cells, was determined. Alterations in osmolality had an inverse effect on cell volume and surface area. Changes in cell volume induced by exposure to anisotonic medium were 52% greater (P > 0.02) than that predicted by the changes in osmolality. Increases in potassium concentration also caused sustained (1-h) concentration-dependent increases in cell volume and surface area. Angiotensin-II did not increase glomerulosa cell volume, but did produce a small dose-dependent transient increase in cell surface area. The results demonstrate that alterations in osmolality do cause sustained changes in cell volume, and thus, membrane stretch could be an important part of the cellular mechanism responsible for causing osmolality-induced changes in the cytosolic calcium concentration and subsequent alterations in aldosterone secretion. Alterations in membrane stretch may also be an important component of potassium-induced, but not angiotensin II-induced, aldosterone secretion.

HLA-DR2 and narcolepsy.

Tissue typing was performed on 14 narcoleptics as defined by both strict sleep laboratory and clinical criteria. Six of these patients were blacks from North America, a race underrepresented in previous studies. All patients were HLA-DR2-antigen positive and had the same HLA-DR2 subtype. Clinical severity of disease was not correlated with HLA-DR2 heterozygosity or (putative) homozygosity. This study confirms that the extremely high association between HLA-DR2 and narcolepsy holds across comparisons of the three races studied to date when both clinical and sleep laboratory data are used. The presence or absence of HLA-DR2 in patients presenting with hypersomnolence may help support or exclude, respectively, a diagnosis of idiopathic narcolepsy.

Suppression of post-hypoxic and post-encephalitic myoclonus with levetiracetam.

Posthypoxic and postencephalitic myoclonus is often poorly controlled with current treatments. The authors successfully treated three patients with posthypoxic and postencephalitic myoclonus by using levetiracetam, a new antiepileptic drug. Levetiracetam appears to be a promising agent for treating action myoclonus caused by hypoxic and encephalitic brain injury-the degree of functional improvement may depend on the severity of associated motor dysfunction.

Ictus emeticus: an electroclinical analysis.

We report 31 episodes of ictal vomiting in nine patients, documented by simultaneous video and EEG recordings. In four patients, chronically implanted subdural electrode arrays recorded the event. Only one patient showed "projectile" vomiting. Amnesia for the episode occurred in eight of the nine patients. Interictal epileptiform abnormalities were maximal in the right temporal region in seven patients and bitemporal in two. Ictal epileptiform abnormalities were lateralized to the right hemisphere and involved temporal lobe structures in all patients. Three of four patients recorded with subdural electrode arrays were seizure-free following right temporal lobectomy, and the fourth continues to have ictus emeticus at a reduced rate. The consistent right hemisphere lateralization of seizures in this series corroborates with earlier reports documenting right-sided lateralization in four of five previous cases. Two features that help delineate paroxysmal vomiting as an ictal event are (1) patient unawareness of vomiting and (2) its association with other ictal phenomena.

Changes in adrenocortical function in male and female guinea-pigs during maturation.

Adrenal cortisol secretion is greater in female than male guinea-pigs and declines with maturation in animals of both sexes. In an attempt to determine the intra-adrenal mechanisms responsible for age and sex influences on corticosteroid output, adrenocortical enzyme activities were compared in sexually immature (3 weeks) and mature (17 weeks) animals. Adrenal mitochondrial protein concentration decreased with maturation in male and female guinea-pigs. 11beta-Hydroxylase activity in adrenal mitochondria was also lower in mature than immature guinea-pigs but greater in males than females. Neither mitochondrial cytochrome P-450 concentration nor cholesterol side-chain cleavage activity varied with age or sex. Adrenal microsomal protein concentration and 21-hydroxylase activity were similar in male and female guinea-pigs of the same age but far greater in mature than immature animals. Microsomal cytochrome P-450 concentration was unaffected by age or sex. Adrenal delta4-steroid (cortisol) hydrogenase activity increased with maturation in both male and female guinea-pigs and was higher in males than females. These observations indicate that cortisol secretion, as modified by age and sex, correlates closely with adrenal steroid reductive but not oxidative metabolism, suggesting that changes in delta4-hydrogenase activity are responsible, at least in part, for the decline in adrenal secretion during maturation in guinea-pigs.

Direct modulation of basal and angiotensin II-stimulated aldosterone secretion by hydrogen ions.

Disturbances in acid-base balance in vivo are associated with changes in plasma aldosterone concentration, and in vitro changes in extracellular pH (pH(o)) influence the secretion of aldosterone by adrenocortical tissue or glomerulosa cells. There is considerable disparity, however, as to the direction of the effect. Furthermore, the mechanisms by which pH(o) independently affects aldosterone secretion or interacts with other secretagogues are not defined. Thus, bovine glomerulosa cells maintained in primary monolayer culture were used to examine the direct effects of pH(o) on cytosolic free calcium concentration ([Ca(2+)](i))( )and aldosterone secretion under basal and angiotensin II (AngII)-stimulated conditions. pH(o) was varied from 7.0 to 7.8 (corresponding inversely to changes in extracellular H(+) concentration from 16 nM to 100 nM). Whereas an elevation of pH(o) from 7.4 to 7.8 had no consistent effect, reductions of pH(o) from 7.4 to 7.2 or 7.0 caused proportionate increases in aldosterone secretion that were accompanied by increases in transmembrane Ca(2+) fluxes and [Ca(2+)](i). These effects were abolished by removal of extracellular Ca(2+). A decrease in pH(o) from 7.4 to 7.0 also enhanced AngII-stimulated aldosterone secretion. This effect was more pronounced at low concentrations of AngII and was manifested as an increase in the magnitude of the secretory response with no effect on potency. In contrast to its effect on AngII-stimulated aldosterone secretion, a reduction of pH(o) from 7.4 to 7.0 inhibited the Ca(2+) signal elicited by low concentrations (

Angiotensin II-stimulated changes in calcium metabolism in cultured glomerulosa cells.

Studies were performed to evaluate the relationships between the effects of angiotensin II on calcium metabolism and cytosolic free calcium concentration in primary monolayer cultures of bovine adrenal glomerulosa cells. As noted previously (Kramer (1988) Am. J. Physiol. (in press], angiotensin II produced rapid dose-dependent increases in cytosolic calcium characterized by both an initial transient component and a secondary sustained component. In the absence of extracellular calcium, angiotensin II produced an initial increase in cytosolic calcium comparable to that produced in the presence of calcium, but failed to maintain a sustained calcium signal. The initial, angiotensin-stimulated increase in cytosolic calcium was inhibited by dantrolene and 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate (TMB-8) in a concentration-dependent fashion. The onset of the angiotensin-stimulated calcium signal was accompanied by a dose-dependent increase in the rate of calcium efflux that achieved a maximum within 2-3 min and then declined to a level 2.5-3 times that from control cells. The initial rate of calcium influx was also increased about 2.5-fold by angiotensin II, an effect that was only apparent in cells that had been treated with the peptide for at least 5 min. These results indicate that the calcium signal produced by angiotensin II is initiated by the rapid mobilization of calcium from an intracellular site(s) and sustained by the continued uptake of extracellular calcium. Moreover, the kinetics of the calcium signal as well as the final, sustained calcium concentration achieved reflect the balance between intracellular calcium release, calcium influx and calcium efflux.

Evidence that angiotensin II decreases mitochondrial calcium in the glomerulosa cell.

The present studies were performed using primary monolayer cultures of bovine glomerulosa cells to determine whether the elevation in cytosolic calcium concentration produced by angiotensin II was accompanied by an elevation in mitochondrial calcium. Exchangeable mitochondria calcium content was assessed indirectly by measuring the changes in cytosolic calcium concentration and calcium efflux produced by the mitochondrial uncoupler, carbonyl cyanide m-chlorophenylhydrazone (CCCP). Total mitochondrial calcium content was also assessed directly by atomic absorption spectroscopy. CCCP had a direct effect to promote calcium release from an oligomycin/antimycin-sensitive (mitochondrial) calcium pool in permeabilized cells. In intact cells, CCCP caused rapid reductions in cellular ATP content and the ratio of ATP to ADP. Still, its effects on calcium dynamics were exerted primarily at the mitochondrial level as evidenced by inhibition with ruthenium red, but not dantrolene. As expected, angiotensin II produced a rapid increase in calcium efflux and an equally rapid and sustained increase in cytosolic calcium concentration. Nonetheless, CCCP-stimulated elevations in cytosolic calcium concentration and calcium efflux were reduced by angiotensin II in a concentration-dependent manner. Total mitochondrial calcium content was also lower in angiotensin-treated than in control cells. These results indicate that angiotensin II causes a net decrease in mitochondrial calcium stores. On the basis of these data, it is proposed that alterations in calcium metabolism initiated by angiotensin II are exerted not only at the membrane and cytosolic levels but also at the level of the mitochondria. Changes in mitochondrial calcium dynamics may directly contribute to the regulation of mitochondrial steroidogenic enzymes by angiotensin II.

Mechanisms of insulin inhibition of ACTH-stimulated steroid secretion by cultured bovine adrenocortical cells.

Results of previous studies indicated that insulin at levels comparable to those in humans during hyperinsulinemia decreased ACTH-stimulated cortisol and androstenedione secretion by bovine adrenal fasciculata-reticularis cells in primary culture. In the present studies this inhibitory action was examined further by comparing the effects of insulin on ACTH-stimulated corticosteroid secretion with its effects on 8-(4-chlorophenylthio)-cAMP (cpt-cAMP), forskolin- and [5val]angiotensin II (Ang II)-stimulated corticosteroid secretion. Effects on corticosteroid secretion were correlated with effects on cAMP accumulation and rates of cAMP production. Monolayers were incubated for 24 h in the absence or presence of each agonist alone or in combination with insulin. Insulin (1.7 x 10(-9) or 17.5 x 10(-9) M) caused about a 50% decrease in cortisol and androstenedione secretion in response to ACTH (10(-11) or 10(-8) M). Insulin also decreased ACTH-stimulated aldosterone secretion by cultured glomerulosa cells. Cpt-cAMP (10(-4) or 10(-3) M)-stimulated increases in cortisol and androstenedione secretion were inhibited by insulin, but to a lesser extent than those in response to ACTH. The inhibition of cpt-cAMP-stimulated steroid secretion was not related to increased degradation of the cyclic nucleotide. Increases in cortisol and androstenedione secretion caused by a submaximal concentration (10(-6) M) of forskolin were decreased 50-70% by insulin. In contrast, insulin failed to significantly affect cortisol or androstenedione secretion caused by a maximal concentration (10(-5) M) of forskolin. The secretory responses to Ang II (10(-8) M) were also unaffected by insulin. The effect of insulin to inhibit ACTH-stimulated steroid secretion was accompanied by a reduction in cAMP accumulation as well as an apparent inhibition of adenylate cyclase activation. These data indicate that the effect of insulin to attenuate ACTH-stimulated corticosteroid secretion results from both an inhibition of ACTH-stimulated adenylate cyclase activity and an antagonism of the intracellular actions of cAMP.

The safety, tolerability, and pharmacokinetics of fosphenytoin after intramuscular and intravenous administration in neurosurgery patients.

STUDY OBJECTIVE: To evaluate the safety, tolerability, and pharmacokinetic profile of fosphenytoin, a water-soluble phenytoin prodrug, after intramuscular and intravenous administration. DESIGN: Open-label study of intramuscular administration, and double-blind, randomized study of intravenous administration. SETTING: Six and ten hospitals throughout the United States for the intramuscular and intravenous multicenter studies, respectively. PATIENTS: Neurosurgical patients who required anticonvulsant prophylaxis or treatment. INTERVENTIONS: In the intramuscular study, 118 patients received loading doses ranging from 480-1500 mg phenytoin equivalents (PE) and daily maintenance doses ranging from 130-1250 mg PE for 3-14 days. In the intravenous study, 88 patients received fosphenytoin and 28 received phenytoin sodium for 3-14 days. Mean +/- SD loading doses and maintenance doses of intravenous fosphenytoin and phenytoin were 1082 +/- 299 mg PE and 411 +/- 221 mg PE, and 1082 +/- 299 mg and 422 +/- 197 mg, respectively. Trough phenytoin concentrations were measured daily in all patients. MEASUREMENTS AND MAIN RESULTS: Intramuscular fosphenytoin was safe and well tolerated, with no irritation found for 99% of all injection site evaluations. Adverse events associated with the drug occurred in 9% of patients, commonly those typical of the parent drug. For intravenous treatment, the frequency of mild irritation at the infusion site was significantly lower in the fosphenytoin group (6%) than in the phenytoin group (25%, p < 0.05). Reductions in infusion rates were required in 17% and 36% of fosphenytoin and phenytoin recipients, respectively. No significant difference was observed relative to adverse events or seizure frequency between the groups. Trough plasma phenytoin concentrations were approximately 10 micrograms/ml or greater in patients receiving at least 3 days of intramuscular and intravenous fosphenytoin. Trough phenytoin concentrations were similar between patients receiving intravenous phenytoin and fosphenytoin on all study days. CONCLUSION: Fosphenytoin can be administered intramuscularly and intravenously in neurosurgical patients to achieve and maintain therapeutic phenytoin concentrations for up to 14 days. Both routes are safe and well tolerated. Intravenous fosphenytoin is significantly better tolerated than intravenous phenytoin sodium in this patient subset.

N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) does not modify the angiotensin II-stimulated calcium signal in cultured bovine glomerulosa cells.

Studies were performed to determine if the sustained elevation in [Ca2+]c noted previously in glomerulosa cells in response to Ang II resulted from the presence of HEPES in the experimental medium. At confluence, primary cultures of bovine glomerulosa cells were maintained for 24-30 h in the presence of either 14 mM NaHCO3/5% CO2 or 25 mM HEPES/4 mM NaHCO3/air. During subsequent experimental periods, cells were incubated in the presence of the corresponding or reciprocal buffer, and the effects of Ang II on [Ca2+]c were monitored by fura 2 fluorescence. Increases in [Ca2+]c produced by Ang II in cells continuously maintained in either HCO3(-) - or HEPES-buffered media were similar, and with the same monolayer the nature of the Ang II-stimulated Ca2+ signal was independent of the buffer employed. Moreover, the Ang II-stimulated Ca2+ signal was not significantly affected by the removal of HCO3- from the superfusate. These results indicate that the sustained increase in [Ca2+]c is not an artifact introduced by the use of HEPES as an experimental buffer, but rather a normal component of the Ang II-stimulated Ca2+ signal.

Steroidogenic refractoriness of bovine adrenocortical cells to dibutyryl cyclic AMP.

The long-term effects of dibutyryl cyclic AMP [(Bu)2-cAMP] on steroidogenesis in bovine adrenocortical cells maintained in primary culture were investigated. During the first 36 h, total steroid production by cells incubated with (Bu)2-cAMP increased progressively. Thereafter, however, there was a marked fall in steroid output. During the first 36 h adrenocortical cells incubated in the presence of (Bu)2-cAMP produced substantially more C19-steroids and 17 alpha-hydroxylated C21-steroids than did cells incubated in the absence of (Bu)2-cAMP. By 48 h, however, such steroid secretion by cells incubated in the continued presence of (Bu)2-cAMP declined toward control levels. By contrast, the secretion of corticosterone and 11-deoxycorticosterone was consistently less by cells maintained in the presence of (Bu)2-cAMP than by cells maintained in its absence. These results suggest that refractoriness results, at least in part, from events which occur distal to the formation of cAMP. The action of ACTH and (Bu)2cAMP to promote the secretion of 17 alpha-hydroxylated C21-steroids and C19-steroids, on the other hand, appears to reflect an increase in the rate of cholesterol side-chain cleavage, as well as an increase in 17 alpha-hydroxylase and possibly also 17, 20-lyase activities.

Relation of the pituitary gland to gonadal hormone effects on the adrenocortical 11beta-hydroxylase system in rats.

Studies were conducted to further examine the mechanisms responsible for gonadal hormone effects on the rat adrenocortical 11beta-hydroxylase system. Despite higher concentrations of cytochrome P-450 and larger 11-deoxycorticosterone (DOC)-induced difference spectra in adrenal mitochondria from females than males, no sex difference in 11beta-hydroxylase activity was observed. The pregnenolone-induced difference spectrum, indicative of cholesterol binding to cytochrome P-450, also was similar in males and females. Testosterone administration to castrated males lowered both 11beta-hydroxylase activity and mitochondrial cytochrome P-450 content. Estradiol produced the opposite effects in castrated females. However, when given to ACTH-replaced hypophysectomized rats, neither testosterone nor estradiol affected cytochrome P-450 levels or the rate of 11beta-hydroxylation. These observations, taken with the known effects of estradiol and testosterone on ACTH secretion in rats and the effects of ACTH on 11beta-hydroxylation, indicate that gonadal hormone effects on the 11beta-hydroxylase system are mediated by ACTH.

Psychogenic chemical sensitivity: psychogenic pseudoseizures elicited by provocation challenges with fragrances.

A middle-aged woman with a 10-year history of disability attributed to chemical sensitivities complained that exposure to specific fragrances immediately elicited seizures. Video-EEG monitoring was performed in a hospital neurodiagnostic laboratory during provocative challenge studies employing fragrances identified by the patient as reliably inducing symptoms. The baseline clinical EEG was normal. Immediately after each provocation with air deodorant and perfume, she consistently showed both generalized tonic/clonic and multifocal myoclonic jerking, at times was nonresponsive, spoke with slurred speech, and complained of right-sided paralysis and lethargy. None of these events were associated with any EEG abnormalities. Psychological assessment (MMPI-2, MCMI-II) revealed personality traits that predisposed her to somatization and beliefs about environmental sensitivities. The convulsions were a manifestation of psychogenic pseudoseizures that had been iatrogenically reinforced.