Nishida procedure associated with botulinum toxin in a long-standing complete bilateral sixth cranial nerve palsy. / Procedimiento de Nishida asociado a toxina botulínica en parálisis completa del sexto par craneal bilateral de larga evolución.

In severe cases of abducens or sixth cranial nerve palsy, transpositions of the superior rectus and inferior rectus into the paralytic lateral rectus have been demonstrated to be useful. Numerous techniques have been described over time to carry out these transpositions, such as the Hummelsheim, O'Connor, Jensen, Foster, or Nishida technique. The first 4 techniques mentioned above have an increased risk of anterior segment ischaemia. The case is presented of a long-standing bilateral sixth cranial nerve palsy secondary to a severe cranial injury. Given the risk of ischaemia of the anterior segment, the Nishida technique was chosen in order to reduce the risk of suffering from this complication. This is combined with botulinum toxin in both middle rectus to try to resolve the muscle contracture associated with the long evolution of the case, obtaining good results at 6, and 12 months after the surgical procedure.

La excavación focal coroidea: hallazgos clínicos y complicaciones / Focal choroidal excavation: Clinical findings and complications

OBJETIVO: Describir los hallazgos clínicos y sus complicaciones en dos pacientes con excavación focal coroidea (EFC). MÉTODOS: Serie retrospectiva de casos. Se realizó exploración oftalmológica que incluía examen con lámpara de hendidura, retinografía, tomografía de coherencia óptica de dominio espectral (SD-OCT), angiofluoresceingrafía (AGF) y angiografía con verde de indocianina sobre cuatro ojos de dos pacientes con ECF. Resultados; En ambos pacientes la exploración de polo anterior y posterior resulta prácticamente normal a excepción de, en el paciente 1, la presencia de un moteado amarillento sobre al área macular del ojo derecho y, en el paciente 2, de una lesión amarillenta sobreelevada con desprendimiento seroso en el área macular del ojo izquierdo. En el momento del diagnóstico, la SD-OCT mostraba en el paciente 1 una EFC conformadora y en el paciente 2 una EFC con líquido subretiniano perilesional y un desprendimiento del neuroepitelio, compatible con una EFC complicada con una coriorretinopatía serosa central (CRSC). Al año de seguimiento, el paciente 1 desarrolló una neovascularización coroidea (NVC) sobre el área excavada. La AGF y angiografía con verde de indocianina revelaban áreas de hipofluorescencia temprana con hiperfluorescencia difusa tardía. Después del tratamiento con ranibizumab intravítreo, la SD-OCT del paciente 1 mostraba ausencia de exudación mientras que en el paciente 2 se objetivaba una resolución parcial del líquido subretiniano. CONCLUSIONES: La ECF es una entidad de reciente diagnóstico y etiología desconocida. Se define como un área de excavación coroidea en ausencia de estafiloma posterior, ectasia escleral, trauma o enfermedad retiniana. Aunque la mayoría de las lesiones se mantienen estables, su asociación con una CRSC o NVC puede ocurrir

OBJECTIVE: To describe the clinical findings and its complications in 2 patients with focal choroidal excavation (FCE). METHODS: A retrospective case-series including 4 eyes of 2 patients with FCE that underwent a comprehensive ophthalmological examination including slit-lamp examination, colour fundus photography, spectral-domain optical coherence tomography (SD-OCT), fluorescein angiography (FA), and indocyanine green angiography. RESULTS: In the 2 patients, both the anterior and posterior segment evaluations were mostly normal despite the of presence yellowish spots in the macular area of the right eye of patient 1, and of a small yellowish elevated lesion with serous macular detachment in the macular area of the left eye in patient 2. At diagnosis, SD-OCT revealed a conforming FCE in patient 1, and in patient 2, an FCE with perilesional subretinal fluid and a neuroepithelium detachment, suspicious of FCE complicated with central serous retinopathy (CSCR). At one year of follow-up, patient 1 developed choroidal neovascularisation (CNV) over the focal choroidal excavation. FA and indocyanine green angiography examinations revealed areas with hypofluorescence in earlier frames, and a diffuse leakage in late frames. After ranibizumab injections, the SD-OCT of patient 1 revealed no active exudation, while patient 2 showed partial resolution of subretinal fluid. CONCLUSIONS: FCE is a newly described entity of unclear aetiology. It is characterised by a choroidal excavation in eyes, with absence of posterior staphyloma, scleral ectasia, trauma, or retinal disease. Although most lesions remain stable, there could be an association with CRSC or CNV

High chlorpyrifos resistance in Culex pipiens mosquitoes: strong synergy between resistance genes.

We investigated the genetic determinism of high chlorpyrifos resistance (HCR), a phenotype first described in 1999 in Culex pipiens mosquitoes surviving chlorpyrifos doses ⩾1 mg l(-1) and more recently found in field samples from Tunisia, Israel or Indian Ocean islands. Through chlorpyrifos selection, we selected several HCR strains that displayed over 10 000-fold resistance. All strains were homozygous for resistant alleles at two main loci: the ace-1 gene, with the resistant ace-1(R) allele expressing the insensitive G119S acetylcholinesterase, and a resistant allele of an unknown gene (named T) linked to the sex and ace-2 genes. We constructed a strain carrying only the T-resistant allele and studied its resistance characteristics. By crossing this strain with strains harboring different alleles at the ace-1 locus, we showed that the resistant ace-1(R) and the T alleles act in strong synergy, as they elicited a resistance 100 times higher than expected from a simple multiplicative effect. This effect was specific to chlorpyrifos and parathion and was not affected by synergists. We also examined how HCR was expressed in strains carrying other ace-1-resistant alleles, such as ace-1(V) or the duplicated ace-1(D) allele, currently spreading worldwide. We identified two major parameters that influenced the level of resistance: the number and the nature of the ace-1-resistant alleles and the number of T alleles. Our data fit a model that predicts that the T allele acts by decreasing chlorpyrifos concentration in the compartment targeted in insects.

[The pharmaceutical record in an emergency department: Assessment of its accessibility and its impact on the level of knowledge of the patient's treatment]. / Le dossier pharmaceutique dans un service d'accueil des urgences : évaluation de son accessibilité et de son impact sur le niveau de connaissance du traitement du patient.

Knowledge of the home medication list may impact therapeutic decisions made in the emergency department (ED). In France, the pharmaceutical record (PR) is a shared professional tool arising from the pharmacists lists of all drugs dispensed during the last 4 months. This PR is included in a microchip equipping a "Vitale" card detained by each beneficiary of health insurance benefits. Since 2011, the law authorises experimentally the consultation of the PR by some hospital doctors such as those working in emergency medicine. The purpose of this work is to assess the accessibility to this PR and to verify the hypothesis that its consultation increases the level of information concerning the treatment of patients admitted in an ED. A prospective, single-center, observational study was conducted during a 15-day period on all patients arriving at the Agen hospital emergency department. Of the 1046 patients enrolled in the study, 828 (79 %) presented a "Vitale" card in which a PR furnished with data was found in 45 % of the cases. The only paper source of information available was provided by the PR (25 %), a medical letter (6 %) or a prescription (3 %). A dual reconciliation between 2 of these sources was possible at a rate of about 4 % each whereas only 3 % of patients showed up with the 3 sources of available information. The consultation of PR by the ED staff is significantly possible. It improves quantitatively the level of information and thus optimizes medication assessment, the initial and critical step of the medical management of patients.

Focal choroidal excavation: Clinical findings and complications.

OBJECTIVE: To describe the clinical findings and its complications in 2 patients with focal choroidal excavation (FCE). METHODS: A retrospective case-series including 4 eyes of 2 patients with FCE that underwent a comprehensive ophthalmological examination including slit-lamp examination, colour fundus photography, spectral-domain optical coherence tomography (SD-OCT), fluorescein angiography (FA), and indocyanine green angiography. RESULTS: In the 2 patients, both the anterior and posterior segment evaluations were mostly normal despite the of presence yellowish spots in the macular area of the right eye of patient 1, and of a small yellowish elevated lesion with serous macular detachment in the macular area of the left eye in patient 2. At diagnosis, SD-OCT revealed a conforming FCE in patient 1, and in patient 2, an FCE with perilesional subretinal fluid and a neuroepithelium detachment, suspicious of FCE complicated with central serous retinopathy (CSCR). At one year of follow-up, patient 1 developed choroidal neovascularisation (CNV) over the focal choroidal excavation. FA and indocyanine green angiography examinations revealed areas with hypofluorescence in earlier frames, and a diffuse leakage in late frames. After ranibizumab injections, the SD-OCT of patient 1 revealed no active exudation, while patient 2 showed partial resolution of subretinal fluid. CONCLUSIONS: FCE is a newly described entity of unclear aetiology. It is characterised by a choroidal excavation in eyes, with absence of posterior staphyloma, scleral ectasia, trauma, or retinal disease. Although most lesions remain stable, there could be an association with CRSC or CNV.

Animal models of REM dysfunctions: what they tell us about the cause of narcolepsy and RBD?

Rapid eye movement sleep behavior disorder (RBD) is a parasomnia characterized by the loss of muscle atonia during paradoxical (REM) sleep (PS). Conversely, cataplexy, one of the key symptoms of narcolepsy, is a striking sudden episode of muscle weakness triggered by emotions during wakefulness, and comparable to REM sleep atonia. The neuronal dysfunctions responsible for RBD and cataplexy are not known. In the present review, we present the most recent results on the neuronal network responsible for PS. Based on these results, we propose an updated integrated model of the mechanisms responsible for PS and explore different hypotheses explaining RBD and cataplexy. We propose that RBD is due to a specific degeneration of a subpopulation of PS-on glutamatergic neurons specifically responsible of muscle atonia, localized in the caudal pontine sublaterodorsal tegmental nucleus (SLD). Another possibility is the occurrence in RBD patients of a specific lesion of the glycinergic/GABAergic premotor-neurons localized in the medullary ventral gigantocellular reticular nucleus. Conversely, cataplexy in narcoleptics would be due to the activation during waking of the caudal PS-on SLD neurons responsible for muscle atonia. A direct or indirect pathway activated during positive emotion from the central amygdala to the SLD PS-on neurons would induce such activation. In normal conditions, the activation of SLD neurons would be blocked by the simultaneous excitation by the hypocretins of the PS-off GABAergic neurons localized in the ventrolateral periaqueductal gray and the adjacent deep mesencephalic reticular nucleus gating the activation of the PS-on SLD neurons.

Early and late onset sepsis in very-low-birth-weight infants from a large group of neonatal intensive care units.

BACKGROUND: Very-low-birth-weight (VLBW, <1500 g birth weight) infants are at high risk for both early- and late-onset sepsis. Prior studies have observed a predominance of Gram-negative organisms as a cause of early-onset sepsis and Gram-positive organisms as a cause of late-onset sepsis. These reports are limited to large, academic neonatal intensive care units (NICUs) and may not reflect findings in other units. The purpose of this study was to determine the risk factors for sepsis, the causative organisms, and mortality following infection in a large and diverse sample of NICUs. METHODS: We analysed the results of all cultures obtained from VLBW infants admitted to 313 NICUs from 1997 to 2010. RESULTS: Over 108,000 VLBW infants were admitted during the study period. Early-onset sepsis occurred in 1032 infants, and late-onset sepsis occurred in 12,204 infants. Gram-negative organisms were the most commonly isolated pathogens in early-onset sepsis, and Gram-positive organisms were most commonly isolated in late-onset sepsis. Early- and late-onset sepsis were associated with increased risk of death controlling for other confounders (odds ratio 1.45 [95% confidence interval [CI] 1.21,1.73], and OR 1.30 [95%CI 1.21, 1.40], respectively). CONCLUSIONS: This is the largest report of sepsis in VLBW infants to date. Incidence for early-onset sepsis and late-onset sepsis has changed little over this 14-year period, and overall mortality in VLBW infants with early- and late-onset sepsis is higher than in infants with negative cultures.

MiniSOX9, a dominant-negative variant in colon cancer cells.

Inherited and acquired changes in pre-mRNA processing have significant roles in human diseases, especially cancer. Characterization of aberrantly spliced mRNAs may thus contribute to understand malignant transformation. We recently reported an anti-oncogenic potential for the SOX9 transcription factor in the colon. For instance, the Sox9 gene knock out in the mouse intestine results in an excess of proliferation with appearance of hyperplasia. SOX9 is expressed in colon cancer cells but its endogenous activity is weak. We looked for SOX9 variants that may impair SOX9 activity in colon cancer cells and we discovered MiniSOX9, a truncated version of SOX9 devoid of transactivation domain as a result of retention of the second intron. A significant overexpression of MiniSOX9 mRNA in human tumor samples compared with their matched normal tissues was observed by real-time reverse transcriptase-PCR. Immunohistochemistry revealed that MiniSOX9 is expressed at high levels in human colon cancer samples whereas it is undetectable in the surrounding healthy tissues. Finally, we discovered that MiniSOX9 behaves as a SOX9 inhibitor, inhibits protein kinase Cα promoter activity and stimulates the canonical Wnt pathway. This potential oncogenic activity of the SOX9 locus gives new insights on its role in colon cancer.

Alternating vigilance states: new insights regarding neuronal networks and mechanisms.

Since the discovery of rapid eye movement (REM) sleep (also known as paradoxical sleep; PS), it is accepted that sleep is an active process. PS is characterized by EEG rhythmic activity resembling that of waking with a disappearance of muscle tone and the occurrence of REMs, in contrast to slow-wave sleep (SWS, also known as non-REM sleep) identified by the presence of delta waves. Here, we review the most recent data on the mechanisms responsible for the genesis of SWS and PS. Based on these data, we propose an updated integrated model of the mechanisms responsible for the sleep-wake cycle. This model introduces for the first time the notion that the entrance and exit of PS are induced by different mechanisms. We hypothesize that the entrance from SWS to PS is due to the intrinsic activation of PS-active GABAergic neurons localized in the posterior hypothalamus (co-containing melanin-concentrating hormone), ventrolateral periaqueductal gray and the dorsal paragigantocellular reticular nucleus. In contrast, the exit from PS is induced by the inhibition of these neurons by a PS-gating system composed of GABAergic neurons localized in the ventrolateral periaqueductal gray and just ventral to it, and waking systems such as the pontine and medullary noradrenergic neurons and the hypothalamic hypocretin neurons. Finally, we review human neurological disorders of the network responsible for sleep and propose hypotheses on the mechanisms responsible for REM behavior disorder and narcolepsy.

The satiety molecule nesfatin-1 is co-expressed with melanin concentrating hormone in tuberal hypothalamic neurons of the rat.

Overlapped in the tuberal hypothalamic area (THA), melanin-concentrating hormone (MCH) and hypocretin (Hcrt) neurons contribute to the integrated regulation of food intake, energy regulation and sleep. Recently, physiological role in appetite suppression has been defined for a novel hypothalamic molecule, nesfatin-1. Acute i.c.v. infusion of nesfatin-1 (nesf-1) promotes anorexia whereas chronic treatment reduces body weight in rats. This satiety molecule is expressed in neurons from areas prominently involved in appetite regulation including THA. We therefore sought functionally relevant to determine whether nesf-1 might be a reliable signaling marker for a new cell contingent within THA, in addition to MCH and Hcrt neurons. Thus, we completed a detailed topographical mapping of neurons immunostained for nesf-1 (nesf-1+) together with cell quantification in each discrete nucleus from THA in the rat. We further combined the immunodetection of nesf-1 with that of MCH or Hcrt to assess possible co-expression. More than three quarters of the nesf-1+ neurons were encountered in nuclei from the lateral half of THA. By double immunofluorescent staining, we showed that all neurons immunoreactive for melanin concentrating hormone (MCH+) neurons depicted nesf-1 immunoreactivity and approximately 80% of the nesf-1+ neurons were labeled for MCH. Maximal co-expression rates were observed in the lateral THA containing approximately 86% of the double-labeled neurons plotted in THA. The present data suggest that nesf-1 co-expressed in MCH neurons may play a complex role not only in food intake regulation but also in other essential integrative brain functions involving MCH signaling, ranging from autonomic regulation, stress, mood, cognition to sleep.

Role of the dorsal paragigantocellular reticular nucleus in paradoxical (rapid eye movement) sleep generation: a combined electrophysiological and anatomical study in the rat.

It is well known that noradrenergic locus coeruleus neurons decrease their activity during slow wave sleep and are quiescent during paradoxical sleep. It was recently proposed that their inactivation during paradoxical sleep is due to a tonic GABAergic inhibition arising from neurons located into the dorsal paragigantocellular reticular nucleus (DPGi). However, the discharge profile of DPGi neurons across the sleep-waking cycle as well as their connections with brain areas involved in paradoxical sleep regulation remain to be described. Here we show, for the first time in the unanesthetized rat that the DPGi contained a subtype of neurons with a tonic and sustained firing activation specifically during paradoxical sleep (PS-on neurons). Noteworthy, their firing rate increase anticipated for few seconds the beginning of the paradoxical sleep bout. By using anterograde tract-tracing, we further showed that the DPGi, in addition to locus coeruleus, directly projected to other areas containing wake-promoting neurons such as the serotonergic neurons of the dorsal raphe nucleus and hypocretinergic neurons of the posterior hypothalamus. Finally, the DPGi sent efferents to the ventrolateral part of the periaqueductal gray matter known to contain paradoxical sleep-suppressing neurons. Taken together, our original results suggest that the PS-on neurons of the DPGi may have their major role in simultaneous inhibitory control over the wake-promoting neurons and the permissive ventrolateral part of the periaqueductal gray matter as a means of influencing vigilance states and especially PS generation.

Influence of aging on cytoplasmic incompatibility, sperm modification and Wolbachia density in Culex pipiens mosquitoes.

Wolbachia are maternally inherited endocellular bacteria, widespread in invertebrates and capable of altering several aspects of host reproduction. Cytoplasmic incompatibility (CI) is commonly found in arthropods and induces hatching failure of eggs from crosses between Wolbachia-infected males and uninfected females (or females infected by incompatible strains). Several factors such as bacterial and host genotypes or bacterial density contribute to CI strength and it has been proposed, mostly from Drosophila data, that older males have a lower Wolbachia load in testes which, thus, induces a lighter CI. Here, we challenge this hypothesis using different incompatible Culex pipiens mosquito strains and show that CI persists at the same intensity throughout the mosquito life span. Embryos from incompatible crosses showed even distributions of abortive phenotypes over time, suggesting that host ageing does not reduce the sperm-modification induced by Wolbachia. CI remained constant when sperm was placed in the spermathecae of incompatible females, indicating that sperm modification is also stable over time. The capacity of infected females to rescue CI was independent of age. Last, the density of Wolbachia in whole testes was highly strain-dependent and increased dramatically with age. Taken together, these data stress the peculiarity of the C.pipiens/Wolbachia interaction and suggest that the bacterial dosage model should be rejected in the case of this association.

The endogenous somnogen adenosine excites a subset of sleep-promoting neurons via A2A receptors in the ventrolateral preoptic nucleus.

Recent research has shown that neurons in the ventrolateral preoptic nucleus are crucial for sleep by inhibiting wake-promoting systems, but the process that triggers their activation at sleep onset remains to be established. Since evidence indicates that sleep induced by adenosine, an endogenous sleep-promoting substance, requires activation of brain A(2A) receptors, we examined the hypothesis that adenosine could activate ventrolateral preoptic nucleus sleep neurons via A(2A) adenosine receptors in rat brain slices. Following on from our initial in vitro identification of these neurons as uniformly inhibited by noradrenaline and acetylcholine arousal transmitters, we established that the ventrolateral preoptic nucleus comprises two intermingled subtypes of sleep neurons, differing in their firing responses to serotonin, inducing either an inhibition (Type-1 cells) or an excitation (Type-2 cells). Since both cell types contained galanin and expressed glutamic acid decarboxylase-65/67 mRNAs, they potentially correspond to the sleep promoting neurons inhibiting arousal systems. Our pharmacological investigations using A(1) and A(2A) adenosine receptors agonists and antagonists further revealed that only Type-2 neurons were excited by adenosine via a postsynaptic activation of A(2A) adenosine receptors. Hence, the present study is the first demonstration of a direct activation of the sleep neurons by adenosine. Our results further support the cellular and functional heterogeneity of the sleep neurons, which could enable their differential contribution to the regulation of sleep. Adenosine and serotonin progressively accumulate during arousal. We propose that Type-2 neurons, which respond to these homeostatic signals by increasing their firing are involved in sleep induction. In contrast, Type-1 neurons would likely play a role in the consolidation of sleep.

Brainstem structures responsible for paradoxical sleep onset and maintenance.

This paper is dedicated to our mentor, Michel Jouvet who inspired our career and transmitted to us his passion for the study of the mechanisms responsible for paradoxical sleep genesis and also that of its still mysterious functions. We expose in the following the progresses in the knowledge in this field brought during 40 years by Michel Jouvet and his team and more recently by the members of a new CNRS laboratory in which we aim to pursue in the path opened by Michel Jouvet.

Effect of chronic treatment with milnacipran on sleep architecture in rats compared with paroxetine and imipramine.

A number of studies in humans and various other species have shown that chronic treatment with antidepressants, such as tricyclics or selective serotonin reuptake inhibitors (SSRIs), induces a decrease or suppression of rapid eye movement (REM) sleep. The effect of a new selective serotonin and noradrenaline reuptake inhibiting (SNRI) antidepressant, milnacipran, on REM sleep has been investigated and compared with that of the SSRI, paroxetine, and the tricyclic, imipramine. Rats injected with vehicle or milnacipran twice a day showed, over 24 h, a similar amount of REM sleep, number and duration of REM sleep episodes to control rats. In contrast, rats treated acutely with imipramine or paroxetine showed a statistically significant decrease in the total quantity of REM sleep. The number of REM sleep episodes was decreased while their duration was increased. A more detailed analysis showed further that the quantity of REM sleep was decreased for the first 4 h following the 9 a.m. injection but not the 7 p.m. injection for milnacipran, during the first 6 h for paroxetine and for the entire light-dark period for imipramine. For all drugs, the quantities of slow-wave sleep and waking over 24 h were not significantly different from control conditions and no rebound of REM sleep occurred during the day following withdrawal. Power spectrum analysis revealed no global changes in the different electroencephalogram (EEG) waves (delta, theta, gamma) between the control condition and the different treatments during waking, slow-wave sleep or REM sleep. Taken together our results indicate that the SNRI, milnacipran, at therapeutic doses, induces only minor disturbances of REM sleep compared with a SSRI and tricyclic antidepressant used. Possible mechanisms responsible for the difference of action on REM sleep of milnacipran are discussed.

Kinectin is a key effector of RhoG microtubule-dependent cellular activity.

RhoG is a member of the Rho family of GTPases that activates Rac1 and Cdc42 through a microtubule-dependent pathway. To gain understanding of RhoG downstream signaling, we performed a yeast two-hybrid screen from which we identified kinectin, a 156-kDa protein that binds in vitro to conventional kinesin and enhances microtubule-dependent kinesin ATPase activity. We show that RhoG(GTP) specifically interacts with the central domain of kinectin, which also contains a RhoA binding domain in its C terminus. Interaction was confirmed by coprecipitation of kinectin with active RhoG(G12V) in COS-7 cells. RhoG, kinectin, and kinesin colocalize in REF-52 and COS-7 cells, mainly in the endoplasmic reticulum but also in lysosomes. Kinectin distribution in REF-52 cells is modulated according to endogenous RhoG activity. In addition, by using injection of anti-kinectin antibodies that challenge RhoG-kinectin interaction or by blocking anti-kinesin antibodies, we show that RhoG morphogenic activity relies on kinectin interaction and kinesin activity. Finally, kinectin overexpression elicits Rac1- and Cdc42-dependent cytoskeletal effects and switches cells to a RhoA phenotype when RhoG activity is inhibited or microtubules are disrupted. The functional links among RhoG, kinectin, and kinesin are further supported by time-lapse videomicroscopy of COS-7 cells, which showed that the microtubule-dependent lysosomal transport is facilitated by RhoG activation or kinectin overexpression and is severely stemmed upon RhoG inhibition. These data establish that kinectin is a key mediator of microtubule-dependent RhoG activity and suggest that kinectin also mediates RhoG- and RhoA-dependent antagonistic pathways.

The gene for a new brain specific RhoA exchange factor maps to the highly unstable chromosomal region 1p36.2-1p36.3.

Guanine nucleotide exchange factors from the Dbl family are proto-oncogenic proteins that activate small GTPases of the Rho family. Here we report the characterization of GEF720, a novel Dbl-like protein related to p115Rho-GEF. GEF720 activated RhoA both in our recently developed Yeast Exchange Assay and in biochemical in vitro exchange assays. GEF720 induced RhoA dependent assembly of actin stress fibers in REF52 fibroblastic cells. In NIH3T3 cells this Dbl-like protein elicited formation of transformation foci with a morphology similar to RhoA-V14 induced foci. In the PC12 neuron-like cell line, expression of GEF720, whose mRNA is brain specific, inhibited NGF-induced neurite outgrowth. Finally, GEF720 gene is located on human chromosome 1 on band 1p36, between Tumor Protein 73 and Tumor Necrosis Factor Receptor 12, two genes rearranged in many neuroblastoma cell lines. Together, these results show that this new Dbl related protein, GEF720, is an exchange factor that can directly activate RhoA in vivo and is potentially involved in the control of neuronal cell differentiation. GEF720 is also a new candidate gene involved in the progression of neuroblastoma and developmental abnormalities associated with rearrangements in the 1p36 chromosomal region.

Profiles of obese children presenting for metabolic evaluation.

BACKGROUND: Obesity, increasingly prevalent among children, causes major morbidities, among which is earlier onset of type 2 diabetes mellitus (DM). METHODS: We reviewed charts of children aged 3 to 18 years (n=106). The population was divided into four age groups. Anthropomorphic measurements, family history, diet and exercise patterns, and selected endocrine/metabolic measurements were recorded, and descriptive statistics were calculated. RESULTS: Obesity in one or both parents correlated with a higher percent of ideal body weight (IBW) (p = 0.01). Fifty-eight percent of the children had first- or second-degree relatives with a history of type 2 DM; 9% had relatives with type 1 DM. Fifty-four percent had dieted and exercised regularly. Mean onset of obesity was at 4.2 +/- 0.9 years. Mean cholesterol was elevated at 176 mg/dl. Average BMI was 26.6 in the youngest children (Group 1; normal mean for this age approximately 15.5), and increased to 37.8 in adolescents (Group 4; normal mean approximately 21). Elevated TSH was present in <1% of the population. The number of patients with an abnormal insulin: glucose ratio (>1:4) increased with age. CONCLUSIONS: Childhood obesity in children is correlated with family histories of obesity and DM. Thyroid dysfunction is seldom found, although mild hypercholesterolemia and insulin insensitivity are prevalent, especially among adolescents.

Raf-MEK-Erk cascade in anoikis is controlled by Rac1 and Cdc42 via Akt.

Signals from the extracellular matrix are essential for the survival of many cell types. Dominant-negative mutants of two members of Rho family GTPases, Rac1 and Cdc42, mimic the loss of anchorage in primary mouse fibroblasts and are potent inducers of apoptosis. This pathway of cell death requires the activation of both the p53 tumor suppressor and the extracellular signal-regulated mitogen-activated protein kinases (Erks). Here we characterize the proapoptotic Erk signal and show that it differs from the classically observed survival-promoting one by the intensity of the kinase activation. The disappearance of the GTP-bound forms of Rac1 and Cdc42 gives rise to proapoptotic, moderate activation of the Raf-MEK-Erk cascade via a signaling pathway involving the kinases phosphatidlyinositol 3-kinase and Akt. Moreover, concomitant activation of p53 and inhibition of Akt are both necessary and sufficient to signal anoikis in primary fibroblasts. Our data demonstrate that the GTPases of the Rho family control three major components of cellular signal transduction, namely, p53, Akt, and Erks, which collaborate in the induction of apoptosis due to the loss of anchorage.