Phenotypic and genetic differentiation of anxiety‐related behaviors in middle childhood

Background: Anxiety‐related behaviors (ARBs) are commonly observed during typical development, yet few studies have investigated their etiology in middle childhood. This study aimed to examine both the phenotypic and genetic differentiation of ARB subtypes within the general population at age 7 and 9. It constituted a follow‐up to an earlier study of ARBs in preschool children. Methods: We investigated the phenotypic structure of ARBs in a large population‐based twin sample, comprising 7,834 twin pairs at age 7 and 3,644 twin pairs at age 9. Quantitative genetic modeling techniques were then used to determine the relative influences of genetic and environmental factors upon different types of ARB and upon the covariation between them. Results: Factor analysis supported the presence of five ARB factors at both ages: negative cognitions, negative affect, fear, obsessive–compulsive behaviors, and social anxiety. Multivariate genetic analyses revealed significant genetic effects and a small but significant influence of shared environment for all ARB subtypes. There was a moderate level of genetic specificity for each subtype as well as some shared genetic effects. Shared environmental influences correlated highly across all types of ARB, whereas nonshared environmental effects were largely subtype specific. Conclusions: The current results suggest that ARBs can be differentiated both phenotypically and genetically within middle childhood, with subtypes reflecting symptom groupings of diagnosable disorders but also aspects of temperament. Although some etiological risk factors lead to a generalized vulnerability to anxiety, others may serve to differentiate between different types of ARBs. Depression and Anxiety, 2009. © 2009 Wiley‐Liss, Inc.     

Hematopoietic progenitor cells (HPC) from mobilized peripheral blood display enhanced migration and marrow homing compared to steady-state bone marrow HPC

OBJECTIVE: Faster engraftment of G-CSF-mobilized peripheral blood (MPB) transplants compared to steady-state bone marrow (ssBM) is well documented and clinically relevant. A number of different factors likely contribute to this outcome. In the present study we explored whether independent of cell number there are intrinsic differences in the efficiency of progenitor cell homing to marrow between MPB and ssBM. METHODS: Mobilization was achieved by continuous infusion of G-CSF alone or in combination with other mobilizing agents. In vivo homing assays, in vitro migration assays, gene expression analysis, and flow cytometry were utilized to compare homing-related in vivo and in vitro properties of MPB and ssBM HPC. RESULTS: Marrow homing of murine MPB HPC, generated by different mobilizing schemes, was reproducibly significantly superior to that of ssBM, in lethally irradiated as well as in nonirradiated hosts. This phenotype was independent of MMP9, selectins, and beta2- and alpha4-integrins. Superior homing was also observed for human MPB HPC transplanted into NOD/SCIDbeta2microglobulin(-/-) recipients. Inhibition of HPC migration abrogated the homing advantage of MPB but did not affect homing of ssBM HPC, whereas enhancement of motility by CD26 inhibition improved marrow homing only of ssBM HPC. Enhanced SDF-1-dependent chemotaxis and low CD26 expression on MPB HPC were identified as potential contributing factors. Significant contributions of the putative alternative SDF-1 receptor, RDC1, were unlikely based on gene expression data. CONCLUSION: The data suggest increased motility as a converging endpoint of complex changes seen in MPB HPC which is likely responsible for their favorable homing.     

VCAM-1 expression in adult hematopoietic and nonhematopoietic cells is controlled by tissue-inductive signals and reflects their developmental origin

Although expression of vascular cell adhesion molecule 1 (VCAM-1) in endothelial cells and its functional implications have been previously appreciated, VCAM-1 expression in other than endothelial cells, especially hematopoietic cells, has been recently recognized and has not been explored in detail. Using normal mice and mice with a conditional ablation of VCAM-1 through a Tie2-driven cre transgene, we have studied the biodistribution and the pattern of VCAM-1 expression in circulating versus tissue-residing cells before and after their enforced mobilization. In the normal mouse, both at basal hematopoiesis or following mobilization, VCAM-1 expression is confined to myeloid cells residing in hematopoietic tissues, whereas free cells in circulation or in body cavities are devoid of VCAM-1 messenger RNA (mRNA) and protein. However, following culture, proliferating myeloid cells, but not lymphoid cells, express VCAM-1. In the VCAM-1-ablated mouse, there is an increase in circulating progenitors as a consequence of their ongoing release from bone marrow, a process enhanced by splenectomy. We postulate that the main mechanism leading to their release is the ablation of VCAM-1 by fibroblastic and by endothelial cells. Ablation of VCAM-1 in fibroblasts by Tie2-driven cre is a novel finding and likely denotes their developmental ancestry by Tie2-expressing (mesenchymal?) progenitor cells during development.     

Unique and redundant roles of alpha4 and beta2 integrins in kinetics of recruitment of lymphoid vs myeloid cell subsets to the inflamed peritoneum revealed by studies of genetically deficient mice

OBJECTIVE: Leukocyte recruitment to inflammatory sites is a prominent feature of acute and chronic inflammation. Instrumental in this process is the coordinated upregulation of leukocyte integrins (among which alpha4beta1 and beta2 integrins are major players) and their cognate receptors in inflamed tissues. To avoid the ambiguity of previous short-term antibody-based studies and to allow for long-term observation, we used genetically deficient mice to compare roles of alpha4 and beta2 integrins in leukocyte trafficking. MATERIALS AND METHODS: Aseptic peritonitis was induced in alpha4 or beta2 integrin-deficient (conditional and conventional knockouts, respectively) and control mice, and recruitment of major leukocyte subsets to the inflamed peritoneum was followed for up to 4 days. RESULTS: Despite normal chemokine levels in the peritoneum and adequate numbers, optimal recruitment of myeloid cells was impaired in both alpha4- and beta2-deficient mice. Furthermore, clearance of recruited neutrophils and macrophages was delayed in these mice. Lymphocyte migration to the peritoneum in the absence of alpha4 integrins was drastically decreased, both at steady state and during inflammation, a finding consistent with impaired lymphocyte in vitro adhesion and signaling. By contrast, in the absence of beta2 integrins, defects in lymphocyte recruitment were only evident when peritonitis was established. CONCLUSIONS: Our data with concurrent use of genetic models of integrin deficiency reveal nonredundant functions of alpha4 integrins in lymphocyte migration to the peritoneum and further refine specific roles of alpha4 and beta2 integrins concerning trafficking and clearance of other leukocyte subsets at homeostasis and during inflammation.     

A rare RET gene exon 8 mutation is found in two Greek kindreds with familial medullary thyroid carcinoma: implications for screening

OBJECTIVE: Familial medullary thyroid carcinoma (FMTC) is caused by germ-line mutations in the RET proto-oncogene. These mutations concern mainly cysteine residues in exons 10 and 11, whereas noncysteine mutations in exons 13-16 are rare. Mutations in other exons have been reported only in isolated families. In this study we have analysed the RET gene in two FMTC families negative for mutations in the above exons. DESIGN: We have analysed exons 7-19 and 21 in one index patient from each family using DNA sequencing. PATIENTS: Twenty-eight subjects from both families were clinically assessed and subsequently molecularly analysed for the presence of RET gene mutations. RESULTS: We have found the mutation c.1597G-->T (Gly533Cys) in two Greek families with FMTC. The mutation was detected in all seven MTC patients of both families as well as in 13 asymptomatic relatives in the heterozygote state, although one of the patients was also a homozygote due to consanguinity. The mutation shows a wide clinical heterogeneity, as there are carrier patients with age of diagnosis ranging from 23 to 88 years. CONCLUSIONS: It is likely that this mutation causes FMTC, as no other mutation was found in the RET gene, the mutation co-segregates with FMTC, and family members without the mutation are clinically unaffected. As the same point mutation was previously found in a large Brazilian family, it may be present in other populations as well. Therefore, exon 8 of RET should be screened in FMTC families with no identified common RET mutations.     

Long-term functional impairment of hemopoietic progenitor cells engineered to express the S1 catalytic subunit of pertussis toxin

OBJECTIVE: A large body of data suggests that pertussis toxin (PTX)-sensitive G protein signals in mature and immature hemopoietic cells control their migration patterns in vitro and in vivo. These effects were derived after treatment of cells or animals with PTX. To circumvent several inherent problems of PTX holotoxin treatment, we expressed the S1 catalytic activity of PTX, thus blocking Gi protein signaling, in 32D murine myeloid progenitor cells and in primary human CD34+ cells, and studied its functional consequences. METHODS: S1 was expressed using viral vectors. Effects of Gi protein blockade on proliferation, migration, adhesion, and gene expression were tested in vitro. RESULTS: S1 expression was nontoxic for the cells; expression and function were stable long-term and not overridden by compensatory mechanisms. S1-transduced 32D cells and primary CD34+ cells migrated poorly and did not contract their cytoskeleton upon treatment with the chemoattractant stromal cell-derived factor -1 (SDF-1), similar to the phenotype induced by PTX treatment. Gene expression studies comparing S1-transduced and control 32D cells uncovered four genes, expression of which was regulated by Gi protein blockade. Of interest, although SDF-1 signaling was inhibited, comparison between SDF-1-treated and untreated cells suggests that SDF-1 stimulation does not depend on de novo gene expression in these cells. Furthermore, when injected into nonobese diabetic/severe combined immunodeficient mice, seeding of S1-expressing 32D cells to bone marrow was largely blocked. CONCLUSION: Expression of S1 is an effective approach for studying long-term functional consequences of Gi protein blockade in hemopoietic cells in vitro and in vivo.     

A systematic evaluation and validation of subtypes of adolescent alcohol use motives: genetic and environmental contributions

Background: Alcohol use motives are closely associated with specific profiles of alcohol use and reflect a subjectively derived decisional framework based on a motivational style of responding. Adult twin studies typically estimate the heritability of alcohol use motives to be between 7 and 42%, although relatively little is known about genetic and environmental influences upon alcohol use motives in adolescence. Methods: Latent class analysis (LCA) models containing 1 through 5 classes were fitted to the data derived from 1,422 adolescent twin and siblings self‐reported alcohol use motives. Using twin models, we estimated the genetic, shared, and nonshared environmental influences to the class membership data derived from the LCA. Results: Four drinking motives classes were identified (family‐oriented, social, enhancement/social, and coping/social). The coping/social and enhancement/social classes were differentiated from the social class on measures of depression, delinquency, and aggressive behavior. Analyses indicated that nonadditive genetic factors accounted for 76% of the variance in the coping/social motives class and additive genetic influences accounted for 66% of the variance in the social motives class. There was a moderate contribution of genetic factors and shared environmental factors influencing class membership of enhancement/social motivated drinkers (28 and 20% explained variance, respectively). Substantial shared environmental influences were revealed for membership of the family‐oriented class (75%). Conclusions: Heritable influences may predispose individuals to drink to cope with negative affect, for social reasons, and to a lesser extent for enhancement. Familial environmental influences shape family‐oriented motives for drinking in adolescents.     

Differential use of endoplasmic reticulum membrane for phagocytosis in J774 macrophages

Sustained phagocytosis requires the continuous replacement of cell-surface membrane from intracellular sources. Depending on the nature of the engulfed particles, a variety of endocytic compartments have been demonstrated to contribute membranes needed for the formation of phagosomes. It has recently been reported that the endoplasmic reticulum (ER) can also fuse with the plasma membrane during phagocytosis [Gagnon, E., Duclos, S., Rondeau, C., Chevet, E., Cameron, P. H., Steele-Mortimer, O., Paiement, J., Bergeron, J. J. & Desjardins, M. (2002) Cell 110, 119-131]. However, there is currently no known mechanistic basis for this fusion process to occur. Here we report that direct ER-plasma membrane fusion during phagocytosis requires the ER resident soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein ERS24/Sec22b and that J774-macrophages react toward the challenge of large (3.0-microm) but not small (0.8-microm) particles by triggering this fusion mechanism, allowing them to access the most abundant endogenous membrane source in the cell, the ER.     

Risk of contrast-induced nephropathy in hospitalized patients with cirrhosis

AIM： TO evaluate the incidence of contrast-induced nephropathy （CIN） in cirrhotic patients and to identify risk factors for the development of CIN.
METHODS： We performed a retrospective review of 216 consecutive patients with cirrhosis who underwent computed tomography （CT） with intravenous contrast at the University of Rochester between the years 2000-2005. We retrospectively examined factors associated with a high risk for CIN, defined as a decrease in creatinine clearance of 25% or greater within one week after receiving contrast.
RESULTS： Twenty-five percent of our patients developed CIN, and 74% of these patients had ascites seen on CT. Of the 75% of patients who did not develop CIN, only 46% had ascites. The presence of ascites was a significant risk factor for the development of CIN （P = 0.0009, OR 3.38, 95% CI 1.55-7.34） in multivariate analysis. Patient age, serum sodium, Model for End-stage Liver Disease score, diuretic use, and the presence of diabetes were not found to be significant risk factors for the development of CIN. Of the patients who developed CIN, 11% developed chronic renal insufficiency, defined as a creatinine clearance less than baseline for 6 wk.
CONCLUSION： Our results suggest that in hospitalized cirrhotic patients, especially those with ascites, the risk of CIN is substantial.