Iterative tyrosine phosphorylation controls non-canonical domain utilization in Crk.

Crk, the prototypical member of a class of Src homology-2 (SH2) and Src homology-3 (SH3) domain containing proteins that controls the coordinated assembly of signaling complexes, is regulated by phosphorylation of Y221 in the linker region, which forms an intramolecular SH2-pY221 auto-clamp to interrupt SH2-N-terminal SH3 domain (SH3N) signaling. Here, we show using LC-MS/MS and by generating phospho-specific antibodies that, iteratively with Y221, the Crk C-terminal SH3 domain (SH3C) is routinely phosphorylated on Y239 and/or Y251 by several extracellular stimuli known to engage Crk. Although phosphorylation at Y221 auto-inhibits the Crk SH2, phosphorylation of the SH3C generates an unconventional phosphoSH3C-SH3N unit in which the SH3N is fully functional to bind polyproline type II ligands and the phosphoSH3C binds de novo to other SH2 domains. Using high-throughput SH2 domain profiling, artificial neural network and position-specific scoring matrix-based bioinformatics approaches, and unbiased mass spectometry, we found that the phosphoSH3C binds several SH2 domain containing proteins, including specific non-receptor tyrosine kinases-Abl via pY251 and C-terminal Src kinase via pY239. Functionally, we show that the phosphoSH3C modulates the Abl-mediated phenotypes of cell spreading and motility. Together, these studies describe a versatile mechanism wherein phosphorylation of Crk at Y221 is not an off switch but redirects signaling from the SH2-SH3N axis to a phosphoSH3C-SH3N axis, with the SH3N as a common denominator.

Haptocorrin as marker of disease progression in fibrolamellar hepatocellular carcinoma.

AIMS: No valid markers are routinely available to follow disease progression in patients with fibrolamellar hepatocellular carcinoma (FLHCC). We report data suggesting that the vitamin B12 binding protein haptocorrin (HC) may prove a suitable marker. METHODS: We monitored a 15-year-old boy diagnosed to have FLHCC by measuring the common markers alanine aminotransaminase, alkaline phosphatase, lactate dehydrogenase, and bilirubin, as well as vitamin B12 (B12), and the forms of the B12 binding proteins. Tumour biopsies were examined immunohistologically. DNA and RNA were extracted from tumour and normal tissue and examined for content of HC DNA and mRNA. RESULTS: The only markers indicative of disease progression were HC and (B12), levels of which were markedly elevated to 84 (11) nmol/L at the time of diagnosis and returned to values within the reference interval (0.43 (0.33) nmol/L) after an apparently radical removal of the tumour. The disappearance rate of HC followed a biphasic curve, the unsaturated protein displaying a half-life of 2.8 days and B12 and saturated HC one of 13 days. Before each diagnosed relapse, an increased concentration of HC was observed. We found a strong immunoreaction against HC in tumour tissue and a high mRNA expression of HC supporting the notion that HC was tumour derived. CONCLUSIONS: Plasma HC proved to be a useful tumour marker in a patient with FLHCC, and we suggest the use of this protein as a marker of disease progression in these patients.

Fetus in fetu: a case report and literature review.

Fetus in fetu is a rare condition in which a fetiform calcified mass often is present in the abdomen of its host, a newborn or an infant. We report on a case of a 19-month-old girl whose plain abdominal radiograph, ultrasonography, and computed tomography scan revealed a mass in which the contents favor a fetus in fetu rather than a teratoma. The noncalcified vertebral column invisible on the radiographs was identified by the pathologist; therefore, the nonvisualization of the vertebral axis on radiography or on computed tomography scan does not exclude the diagnosis of fetus in fetu.

Partial failure of sternal fusion in an adolescent.

We describe the case of an adolescent girl who had an isolated cranial sternal cleft without any associated abnormalities; the cleft had been well tolerated since her birth. A review of the literature shows that such cases are uncommon. In such cases, surgery is only for cosmetic reasons.

Mediastinal lipomatosis.

Mediastinal lipomatosis is a benign condition characterized by a large amount of mature adipose tissue within the mediastinum. It widens the mediastinum and may simulate mass lesions, thus leading to diagnostic errors. We describe a new case of a huge mediastinal lipomatosis and review 36 cases previously reported in the literature. Computed tomography has an important role in the diagnosis of this disease. To avoid invasive and unnecessary procedures, this diagnosis should be considered in any patient with Cushing's syndrome.

[Endobronchial lipoma: apropos of a case with dual localization]. / Le lipome endobronchique: à propos d'un cas à double localisation.

Endobronchial lipoma is an uncommon benign tumor. It is composed of fat tissue and is visible on CT scanner. We report an unusual case of a patient who developed two endobronchial lipomas. The first lipoma was removed 10 years earlier. We emphasize the contribution of computed tomography in the diagnosis of endobronchial lipoma. Cases of multiple lipomas are very scarce in the literature.

Effect of anabolic steroids on behavior and physiological characteristics of female mice.

Adult female mice were exposed to a combination of four anabolic-androgenic steroids for 9 weeks at doses that were either one or five times the androgenic maintenance level for male mice. Relative to control females, steroid treatment depressed gonadotropin secretion and increased both dry body weight and fat content but without an increase in food intake. Steroid treatment depressed spontaneous use of a running wheel and open-field activity, and it increased aggressiveness. It also eliminated a behavior related to encounters between the sexes--the rejection of genital inspection. There was no effect of steroid treatment on the time required to recover from 10 h of enforced running on a treadmill. Overall, regardless of the test or measure, there was little or no difference in the effect of the high and low dose of steroids. This indicates a threshold of response below the low dose used in these studies, which itself is probably well below that used by many female athletes and body builders.

Oleanane and ursane glycosides from Schefflera octophylla.

Twelve triterpene glycosides were isolated from the bark of Schefflera octophylla of Vietnamese origin. Three of them were identified as asiaticoside, cauloside D and 3 alpha-hydroxyurs-12-ene-23,28-dioic acid 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside. The structures of nine new glycosides were elucidated by chemical and spectroscopic evidence. Including the known compounds, the 12 glycosides consisted of six pairs of corresponding ursene and oleanene glycosides and all of them had the same triose moiety at the C-28 position. The names scheffurosides A-F and scheffoleosides B-F were proposed for corresponding pairs of ursene and oleanene glycosides, respectively.

Cardiovascular effects produced by microinjection of calcitonin gene-related peptide into the rat central amygdaloid nucleus.

Recent studies have provided evidence for a dense localization of calcitonin gene-related peptide (CGRP) and its receptors within the central amygdaloid nucleus (Ce) in rat brain. Since this nucleus has been thought to play a role in central cardiovascular regulation, the present study examined the cardiovascular effects subsequent to the microinjection of CGRP into the Ce. Doses of 50-500 pmol of CGRP produced a significant elevation of 11-15% in systolic, diastolic and mean arterial pressures. Heart rate was significantly elevated by 16-18% by these doses of CGRP. The time course of the effects of CGRP revealed that onset of action occurred after 15-20 min, peak effects were seen at approximately 30-40 min after onset and the effects of the peptide usually lasted for at least 2 hr, after which time BP and HR values returned to baseline. The present study demonstrates that CGRP produces significant increases in both BP and HR when pmol doses of the peptide are injected into the Ce. It is suggested that in the Ce, CGRP plays a neuromodulatory role in cardiovascular function.

Effect of 5,7-dihydroxytryptamine on the concentration of individual proteins in different areas of the rat brain.

Proteins which are apparently regulated in concentration in two different areas of the rat brain by the indole neurotransmitter serotonin were identified using two-dimensional gel electrophoresis combined with computerized scanning densitometry. Reduction in central serotonin levels produced a decrease in the concentration of 3 different proteins (2 in the parietal cortex, 1 in the hippocampus). Two proteins, both in the hippocampus, were elevated in concentration following serotonin depletion. These results demonstrate that there exist in the brain a limited number of proteins whose concentration is influenced by serotonin.

Effects of bilateral lesion of the locus coeruleus and of neonatal administration of 6-hydroxydopamine on the concentration of individual proteins in rat brain.

The role that norepinephrine plays in regulating the concentration of different proteins in the parietal cortex, hippocampus and cerebellum was assessed by investigating the effects of either a bilateral lesion of the locus coeruleus or neonatal administration of 6-hydroxydopamine. Two weeks after lesioning the locus coeruleus, the concentration of two different proteins was elevated in the hippocampus; a third protein was reduced in concentration in this brain area as a result of the lesion. Three proteins were affected in concentration in the cerebellum after the locus coeruleus lesion--two were elevated in concentration and one was reduced in concentration. No proteins were altered in concentration in the parietal cortex as a result of the lesion. Seventy days after neonatal treatment with 6-hydroxydopamine, a total of 6 proteins were found to be changed. Four of these (one in the hippocampus and 3 in the parietal cortex) were reduced in concentration while two proteins (both in the cerebellum) were elevated in concentration after neonatal treatment with the catecholamine neurotoxin. There was little overlap between those proteins affected in concentration by the bilateral lesion of the locus coeruleus and those changed by neonatal treatment with 6-hydroxydopamine. These results suggest that the concentration of a number of different proteins may, under normal physiological conditions, be regulated in vivo by norepinephrine in the brain.

Increases in heart rate and blood pressure produced by microinjections of atrial natriuretic factor into the AV3V region of rat brain.

Recent studies have provided evidence for the dense localization of atrial natriuretic factor (ANF) in the anteroventral third ventricle (AV3V) region of the rat brain. This area is currently thought to be involved in the regulation of blood pressure and fluid and electrolyte balance. To investigate whether ANF may play a role in central cardiovascular regulation, the effects of microinjection of ANF into the preoptic suprachiasmatic nucleus (POSC), which is located in the AV3V region of the brain, were examined in the present study. Low doses of ANF (2-4 pmol) produced modest elevations in systolic and diastolic pressures, approximately 10-14%, and a small rise in HR of roughly 7%. Higher doses of ANF (20-40 pmol) produced significant increases in systolic (15-19%), mean arterial (12-14%) and pulse (25-36%) pressures. In addition, much larger increases in HR, approximately 20%, were produced by these higher doses of ANF. The onset of effects produced by ANF on BP and HR was seen 15-45 min after injection. Peak effects were usually observed approximately 60-150 min after onset, and the duration of the effect was 2-4 hours, after which time values usually returned to baseline. These studies indicate that ANF produces significant increases in BP and HR when injected at pmol doses into the POSC, and lends support to the idea that this peptide may play an important role in central cardiovascular regulatory mechanisms.

Effect of reduction of cholinergic input on the concentration of specific proteins in different cortical regions of the rat brain.

The effect of lesioning the nucleus of the tractus diagonalis on the concentration of specific proteins in the hippocampus and the occipital cortex was assessed. Rats received either a sham or an electrolytic lesion and were killed 9 or 35 days later. Tissue samples were removed by microdissection and proteins were separated by two-dimensional gel electrophoresis. Gels were stained with silver, and then analyzed by quantitative computerized scanning densitometry. Of the 143 proteins analyzed, only four were found to be altered in concentration in both brain areas as a result of the lesion. Protein 82 (molecular weight 39,000, pI 6.5) was reduced 71% in the hippocampus and 50% in the occipital cortex 9 days after the lesion, while protein 109 (molecular weight 32,000, pI 6.4) was elevated 140% in the hippocampus and 130% in the occipital cortex at the same time point. Protein 6 (molecular weight 58,000, pI 5.7) was unchanged 9 days after the lesion but was elevated in concentration in both the hippocampus and the occipital cortex 35 days after lesioning. Protein 74 (molecular weight 39,000, pI 5.8) was elevated in concentration both 9 and 35 days after lesioning in the occipital cortex, but only at day 35 in the hippocampus. These results demonstrate that the concentration of these four proteins may be regulated by the cholinergic input to the hippocampus and the occipital cortex. The possibility exists that one or more of these proteins may be related to either the muscarinic or nicotinic cholinergic receptor in rat brain.

Verrucous carcinoma of the face.

A case of verrucous carcinoma occurred on the face of a patient and prompted a review of the literature on this disorder. It is difficult to make a histopathologic diagnosis in such cases.