Prevalence and evolution of intracranial hemorrhage in asymptomatic term infants.

BACKGROUND AND PURPOSE: Subdural hemorrhage (SDH) is often associated with infants experiencing nonaccidental injury (NAI). A study of the appearance and natural evolution of these birth-related hemorrhages, particularly SDH, is important in the forensic evaluation of NAI. The purpose of this study was to determine the normal incidence, size, distribution, and natural history of SDH in asymptomatic term neonates as detected by sonography (US) and MR imaging within 72 hours of birth. MATERIALS AND METHODS: Birth history, delivery method, duration of each stage of labor, pharmaceutic augmentation, and complications during delivery as well as postnatal physical examination were recorded. Brain MR imaging and US were performed on 101 asymptomatic term infants at 3-7 days, 2 weeks, 1 month, and 3 months. Clinical follow-up at 24 months was recorded. RESULTS: Forty-six neonates had SDH by MR imaging within 72 hours of delivery. SDH was seen in both vaginal and cesarean deliveries. All neonates were asymptomatic, with normal findings on physical examination. All 46 had supratentorial SDH seen in the posterior cranium. Twenty (43%) also had infratentorial SDH. US detected 11 of the 20 (55%) infratentorial SDHs and no supratentorial SDH. Most SDHs present at birth were

Molecular findings in symptomatic and pre-symptomatic Alexander disease patients.

BACKGROUND AND OBJECTIVE: Alexander disease is a slowly progressive CNS disorder that most commonly occurs in children. Until recently, the diagnosis could only be established by the histologic finding of Rosenthal fibers in brain specimens. Mutations in the glial fibrillary acidic protein (GFAP) gene have now been shown in a number of biopsy- or autopsy-proven patients with Alexander disease. A prospective study on patients suspected to have Alexander disease was conducted to determine the extent to which clinical and MRI criteria could accurately diagnose affected individuals, using GFAP gene sequencing as the confirmatory assay. METHODS: Patients who showed MRI white matter abnormalities consistent with Alexander disease, unremarkable family history, normal karyotype, and normal metabolic screening were included in this study. Genomic DNA from patients was screened for mutations in the entire coding region, including the exon-intron boundaries, of the GFAP gene. RESULTS: Twelve of 13 patients (approximately 90%) were found to have mutations in GFAP. Seven of those 12 patients presented in infancy with seizures and megalencephaly. Five were juvenile-onset patients with more variable symptoms. Two patients in the latter group were asymptomatic or minimally affected at the time of their initial MRI scan. The mutations were distributed throughout the gene, and all involved sporadic single amino acid heterozygous changes that changed the charge of the mutant protein. Four of the nine changes were novel mutations. CONCLUSIONS: In symptomatic and asymptomatic patients with a predominantly frontal leukoencephalopathy by MRI, GFAP gene mutation analysis should be included in the initial diagnostic evaluation process for Alexander disease.

Cerebral vasculitis in an adolescent with juvenile rheumatoid arthritis.

A 16-year-old girl with longstanding polyarticular juvenile rheumatoid arthritis was referred from Chuuk State, Federated States of Micronesia, for evaluation and management of weakness and joint pains. She had a right hemiparesis with central facial weakness, polyarticular arthritis, and a dense cataract of the left eye with phthisis bulbi. Extensive evaluation using magnetic resonance angiography revealed vasculitis of the anterior and middle cerebral arteries. She was treated with "pulse" doses of methylprednisolone intravenously and she improved remarkably. Repeat angiography demonstrated dramatic improvement of the vasculitis. There is a paucity of literature regarding cerebral vasculitis in juvenile rheumatoid arthritis. That literature is reviewed, and our patient is discussed with regard to the few published reports.

Glucose-regulated protein-78 expression in the rat adrenal cortex.

We have postulated that steroidogenesis activator polypeptide (SAP) is a product of glucose-regulated protein-78 (grp78) proteolysis on the basis of a number of considerations, including a striking sequence similarity between the carboxyl-terminal region of grp78 and SAP. Since ACTH stimulates the rapid intracellular accumulation of SAP, experiments were conducted to determine whether ACTH might also regulate levels of grp78 mRNA and/or protein. Using a grp78 cDNA probe, Northern analysis of total RNA isolated from hypophysectomized or dexamethasone-suppressed rats revealed that neither treatment had a measurable influence on steady-state levels of grp78 mRNA over a 4-day period. Moreover, immunoblotting with an antiserum directed against a shared grp78/SAP sequence failed to detect a significant change in the grp78 content of adrenal homogenates from dexamethasone-suppressed rats as compared with untreated controls. On the other hand, grp78 in cultured rat adrenocortical cells fell to 50% of that in time-zero controls after 72 h in the absence of ACTH, whereas inclusion of ACTH in the medium blocked this decline. We conclude that while adrenocortical grp78 may be under some measure of trophic ACTH control, the rapid fluctuations reported for SAP are not likely to be driven by large changes in the size of the grp78 pool.

Beta-endorphin responses to metyrapone and dexamethasone in depressed patients.

Controversy continues over the characteristics of beta-endorphin secretion in depression. Beta-endorphin plasma levels were measured in 30 drug-free male patients with a DSM-III-R major depressive disorder and 21 healthy controls. Depressed patients displayed significantly lower beta-endorphin plasma levels in baseline conditions, after the single dose metyrapone test, and after the dexamethasone suppression test. The activation of hypothalamic-pituitary-adrenal (HPA) axis in depression might be due, at least in part, to low levels of beta-endorphin. These results suggest that HPA axis dysregulation in depression may involve peptides other than ACTH.

Effects of metyrapone and dexamethasone on pro-gamma-MSH and ACTH levels in depressed patients.

There is current controversy over the mechanisms underlying hypothalamic-pituitary-adrenal (HPA) axis hyperactivity in depression. Pro-gamma-MSH, a portion of the N-terminal region of POMC, has been shown to act synergistically with ACTH in stimulating corticosteroid secretion in vitro and in vivo. Pro-gamma-MSH and ACTH plasma levels were measured in 30 drug-free male patients with a DSM-III-R major depressive disorder and 21 healthy controls. The baseline levels were similar in the two groups. After single-dose metyrapone stimulation, both hormones increased, but pro-gamma-MSH was significantly higher in control subjects than in depressives. After overnight 1 mg dexamethasone, ACTH was significantly less suppressed in depressives than controls. These results suggest that HPA axis dysregulation in depression may involve peptides other than ACTH and be more complex than previously reported.

Effects of metyrapone and dexamethasone upon pro-gamma-MSH plasma levels in depressed patients and healthy controls.

There is current controversy over the mechanisms underlying hypothalamic-pituitary-adrenal (HPA) axis hyperactivity in depression. Pro-gamma-melanocyte-stimulating hormone (MSH), a portion of the N-terminal region of pro-opiomelanocortin, has been shown to act synergistically with adrenocorticotropic hormone (ACTH) in stimulating corticosteroid secretion both in vitro and in vivo. Pro-gamma-MSH and ACTH plasma levels were measured in 30 drug-free male patients with a DSM-IIIR major depressive disorder and 21 healthy controls. The baseline levels were similar in the two groups. After single-dose metyrapone stimulation, both hormones increased, but pro-gamma-MSH was significantly higher in control subjects than in depressives. After overnight 1-mg dexamethasone, ACTH was significantly less suppressed in depressives than controls. These results suggest that HPA axis dysregulation in depression may involve peptides other than ACTH and be more complex than previously reported.

The rat 78,000 dalton glucose-regulated protein (GRP78) as a precursor for the rat steroidogenesis-activator polypeptide (SAP): the SAP coding sequence is homologous with the terminal end of GRP78.

Based on the striking sequence identity between the amino acid sequence of rat steroidogenesis-activator polypeptide (SAP) and the carboxyl terminus of the 78,000 dalton glucose-regulated protein (GRP78), the precursor-product relationship between GRP78 and SAP was investigated in Leydig cells. Immunoblot analysis with peptide antibodies specific for GRP78 and SAP showed that the putative SAP precursor is also immunoreactive with the anti-GRP78 antibody. Genomic blot hybridizations further revealed that GRP78 is neither rearranged nor amplified in the H-540 Leydig cell tumor, the original source for SAP. Further, there appears to be a single copy of the SAP coding sequence within the rat genome. This sequence resides within the last exon of GRP78. Our observations support the hypothesis that, in steroidogenic cells, SAP is likely to be derived from posttranslational processing of a very minor fraction of GRP78.

The kinetics of steroidogenesis activator polypeptide in the rat adrenal cortex. Effects of adrenocorticotropin, cyclic adenosine 3':5'-monophosphate, cycloheximide, and circadian rhythm.

The behavior of steroidogenesis activator polypeptide (SAP), a recently described modulator of cholesterol side-chain cleavage activity (Pedersen, R. C., and Brownie, A. C. (1987) Science 236, 188-190), was investigated in rat adrenocortical cells using a specific radioimmunoassay. In response to a maximal dose of adrenocorticotropic hormone (ACTH) (1 nM) or of 8-Br-cAMP (1 mM), an increase in intracellular SAP begins rapidly (less than 1 min) and reaches half-maximal and maximal levels (16-fold greater than basal) at 3 and 15 min, respectively. A plateau at this maximal concentration of SAP is then maintained. The levels of intracellular SAP content and of corticosterone output exhibit a similar dose-dependent response to ACTH (EC50 = 25 and 30 pM, respectively). Treatment of ACTH-stimulated cells with cycloheximide reverses the rise in SAP (t1/2 congruent to 5-7 min). In vivo the SAP content of adrenals from quiescent rats is concordant with the circadian rhythm of the pituitary-adrenal axis; at the apex (1800 h), adrenal SAP is 13-fold higher than at the nadir (0800 h), paralleling 2- and 7-fold variations in cholesterol side-chain cleavage activity and serum corticosterone levels, respectively. At both time points, SAP levels rise in response to stress. Of the rat tissues examined, only the major steroid-forming organs (adrenal cortex and gonads) had significant levels of immunoreactive, cAMP-responsive SAP, while cAMP-unresponsive immunoreactivity was also detectable in the thymus, spleen, and brain. Considered together with the biological activity previously demonstrated for SAP in vitro, these data are consistent with its role as a cAMP-dependent, cycloheximide-sensitive modulator of steroid biosynthesis.

Steroidogenesis activator polypeptide (SAP) in the guinea pig adrenal cortex.

Steroidogenesis activator polypeptide (SAP), a cytosolic stimulator of cholesterol side-chain cleavage (cholesterol SCC) previously characterized in the rat, was isolated from guinea pig adrenal cortex. This factor exhibited behavior on reverse-phase high-performance liquid chromatography (HPLC) that was indistinguishable from authentic SAP and crossreacted fully in a SAP radioimmunoassay. In dexamethasone-suppressed guinea pigs neither the concentrations of immunoreactive adrenal SAP nor the levels of cholesterol SCC activity were significantly different between the outer zones (zonae glomerulosa and fasciculata) and the inner zone (zona reticularis). However, at 10 min after treatment of dexamethasone-suppressed animals with ACTH1-24, the outer zone content of SAP was increased 42-fold over unstimulated controls whereas inner zone SAP was elevated only 4-fold. At the same time, cholesterol SCC activity was increased 2-fold in the outer zones but unchanged in the inner zone. In addition to SAP itself, a crossreacting 82 kDa protein (p82)--similar to the putative SAP precursor identified in the rat--was detected on two-dimensional immunoblots of guinea pig whole adrenal homogenate. There were no significant differences in the protein concentrations of p82 or of cytochrome P-450scc between zones, either with or without ACTH treatment. We conclude that the widely reported contrast in corticosteroidogenic potential between the zona fasciculata and the zona reticularis of the guinea pig may reflect a differential capacity to generate SAP, and thus activate cholesterol SCC, in response to ACTH.

Steroidogenesis activator polypeptide may be a product of glucose regulated protein 78 (GRP78).

Cholesterol side-chain cleavage is sensitive to antibiotic inhibitors of protein synthesis, suggesting that a labile protein may play a regulatory role in this process. We have previously characterized such a factor--steroidogenesis activator polypeptide (SAP). Given the low molecular weight of SAP (Mr 3215), a SAP precursor has been sought. Using immunoblotting techniques with two polyclonal antisera directed against portions of the SAP sequence, a single protein of apparent Mr 82,000 (p82) can be detected in rat adrenocortical tissue. Our data suggest that adrenal p82 is most likely the widely-distributed minor heat shock protein, glucose regulated protein 78 (GRP78). The two proteins share biochemical attributes, including pI (5.2) and ATP affinity, and the reported amino acid sequences for SAP and for the carboxyl-terminal end of GRP78 are nearly identical. We propose that SAP is cleaved from GRP78--or a cognate protein--and that this proteolysis is regulated in a manner characteristic of steroidogenic tissues.

Steroidogenesis-activator polypeptide isolated from a rat Leydig cell tumor.

A cycloheximide-sensitive protein responsive to adenosine 3',5'-monophosphate has been postulated to participate in the regulation of cholesterol side-chain cleavage activity in steroidogenic tissues. Such a steroidogenesis activator polypeptide (SAP) had been isolated from rat adrenocortical tissue and partially characterized. Now a polypeptide with comparable chromatographic behavior and biological activity has been purified from the rat H-540 Leydig cell tumor in quantities sufficient for amino acid sequencing. The activator contains 30 amino acid residues and has a molecular weight of 3215. The synthetic construct based on this sequence is virtually equipotent with native H-540 tumor SAP in an adrenal mitochondrial cholesterol side-chain cleavage assay. Hormonal regulation of the intracellular concentration of this activator may control the rate of cholesterol metabolism in steroidogenic organs.

Gamma 3-melanotropin promotes mitochondrial cholesterol accumulation in the rat adrenal cortex.

Gamma 3-melanotropin (gamma 3-MSH) facilitates a rapid, dose-dependent, and cycloheximide-insensitive increase in the concentration of mitochondrial free cholesterol in the adrenals of hypophysectomized rats. Physiological concentrations of various synthetic and native preparations of gamma 3-MSH are potent, while gamma-MSH is not. This cholesterol accumulation coincides with the activation of cholesteryl ester hydrolysis by gamma 3-MSH, while the rates of cholesterol esterification and of mitochondrial cholesterol side-chain cleavage are unaffected. Conversely, ACTH inhibits cholesterol ester esterification. Therefore, gamma 3-MSH and ACTH together may coordinate a substantial shift in the set-point of cholesteryl ester in equilibrium cholesterol cycling toward the right. Because ACTH also activates cholesterol side-chain cleavage, this coordinate effect on the flux of cholesterol substrate is manifest as a potentiation of corticosteroidogenesis by gamma 3-MSH. These data extend our previous studies demonstrating that pro-gamma-MSH polypeptides have an endocrine influence on the rat adrenal cortex.

High density lipoprotein influences the response of rat adrenocortical cells to gamma 3-melanotropin.

Gamma 3-melanotropin (gamma 3-MSH) exhibits a marked dose-dependent synergism with ACTH1-24 on corticosterone production by cells isolated from the inner zones of the rat adrenal cortex. This phenomenon is demonstrated to best advantage when donor animals are killed after stress or pretreatment with ACTH. If adrenal cells are prepared from quiescent or hypophysectomized animals, the inclusion of high density lipoprotein (HDL) in the incubation medium is required for a significant gamma 3-MSH response. Dibutyryl cAMP can successfully substitute for ACTH1-24 in these incubations but rat low density lipoprotein does not reproduce the HDL effect. These data are consistent with our in vivo studies demonstrating that gamma 3-MSH potentiation is a product of increased cholesterol mobilization within the adrenal cortex and suggest that in the rat, a significant source of the cholesteryl ester pool which is responsive to gamma 3-MSH may derive from circulating HDL.

Steroidogenesis activator polypeptide (SAP) in the rat ovary and testis.

A steroidogenesis activator polypeptide (SAP) has previously been identified in the rat adrenal cortex (Pedersen and Brownie, Proc. natn. Acad. Sci. U.S.A. 80 (1983) 1882-1886). This factor apparently facilitates the association of mitochondrial cholesterol with the cholesterol side-chain cleavage cytochrome P-450, a reaction which is generally regarded as rate-controlling in the steroid biosynthetic pathway. The same preparative techniques have now been applied in a search for this material in other rat tissues. Among those investigated, the ovary and testis demonstrate significant concentrations of a factor which is biologically and chromatographically similar to adrenal SAP. In the immature ovary the activator becomes manifest after priming with PMSG and rises dramatically during hCG-stimulated luteinization, an increase which can be blunted with cycloheximide. In the adult rat testis it is increased acutely by treatment with hCG or dibutyryl cAMP and is diminished in response to hypophysectomy or cycloheximide. At approximately equivalent concentrations (10(-7) M), preparations of the activator from the adrenal cortex, the testis, and the superovulated ovary each enhance the activity of cholesterol side-chain cleavage in adrenocortical mitochondria by 5- to 6-fold over basal controls. We conclude that steroidogenic organs share a similar or identical intracellular modulator of cholesterol----pregnenolone conversion which is under pituitary control.

Control of aldosterone secretion by pituitary hormones.

Pro-gamma-melanotropins (pro-gamma-MSH) are implicated in the control of aldosterone secretion by the normal adrenal cortex and in idiopathic hyperaldosteronism. In contrast with other melanotropins (alpha- and beta-MSH), the pro-gamma-MSH increase aldosterone secretion by normal adrenals only in the presence of adrenocorticotrophic hormone (ACTH). However, in aldosteronoma cells this stimulatory effect of the pro-gamma-MSH is not ACTH-dependent. The mechanism of pro-gamma-MSH action on aldosterone biosynthesis may involve activation of cholesteryl ester hydrolase in zona glomerulosa, resulting in an increased provision of cholesterol for steroidogenesis.

Plasma immunoreactive gamma melanotropin in patients with idiopathic hyperaldosteronism, aldosterone-producing adenomas, and essential hypertension.

A non-ACTH aldosterone-stimulating factor(s) has been implicated in the pathogenesis of idiopathic hyperaldosteronism (IHA). Although this factor has not been fully characterized, some evidence suggests that it may be related to a pro-gamma-melanotropin (pro-gamma-MSH), derived from the NH2-terminal region of pro-opiomelanocortin. In the present study, plasma immunoreactive (IR-) gamma-MSH levels at 0800 h in patients with IHA were evaluated (90 +/- 17 fmol/ml; range: 13-173 fmol/ml) and found to be significantly higher (P less than 0.05) than those in subjects with aldosterone-producing adenomas (33 +/- 8 fmol/ml), essential hypertension (33 +/- 6 fmol/ml), and normotensive controls (19 +/- 2 fmol/ml). Seven of nine IHA subjects had circulating IR-gamma-MSH levels above the normal range (greater than 35 fmol/ml). In plasmas sampled at 1200 h, IR-gamma-MSH was significantly higher in patients with IHA (95 +/- 26 fmol/ml) and adenomas (63 +/- 23 fmol/ml), as compared with essential hypertensives (31 +/- 6 fmol/ml) and normotensives (19 +/- 3 fmol/ml). Mean plasma IR-ACTH, plasma cortisol, and urinary cortisol levels did not differ significantly between any of these groups. In order to evaluate the effect of a pro-gamma-MSH in vitro, adrenal adenoma tissue was obtained from two patients, one with elevated IR-gamma-MSH (61 fmol/ml) and a second with low IR-gamma-MSH (12 fmol/ml). Aldosterone secretion by dispersed adenoma cells from the former, but not the latter, underwent a fourfold dose-dependent (10(-14)-10(-9) M) increase in response to human Lys-gamma 3-MSH. These data suggest that a pro-gamma-MSH may be implicated as a pathogenic factor in a subset of patients with primary aldosteronism, particularly among those differentially diagnosed as having IHA.