Anteroposterior skeletal and dental changes after early Class II treatment with bionators and headgear

In this study we examined anteroposterior cephalometric changes in children enrolled in a randomized controlled trial of early treatment for Class II malocclusion. Children, aged 9.6 +/- 0.8 years at the start of study, were randomly assigned to control (n = 81), bionator (n = 78), and headgear/biteplane (n = 90) treatments. Cephalograms were obtained initially, after Class I molars were obtained or 2 years had elapsed, after an additional 6 months during which treated subjects were randomized to retention or no retention and after a final 6 months without appliances. Calibrated examiners, blinded to group, used Johnston's analysis to measure anteroposterior cephalometric changes. Statistical analysis was used to determine annual skeletal and dental changes during treatment, retention, and follow-up, and overall. Our data reveal that both bionator and head-gear treatments corrected Class II molar relationships, reduced overjets and apical base discrepancies, and caused posterior maxillary tooth movement. The skeletal changes, largely attributable to enhanced mandibular growth in both headgear and bionator subjects, were stable a year after the end of treatment, but dental movements relapsed.

Enhanced cytokine detection by a novel cell culture-based ELISA

Production of some cytokines, such as IL-4 and IL-10, often occurs at low levels and is difficult to detect by standard ELISA techniques. In many cases the level of detection is at or near to the limits of sensitivity of the assay due either to minimal synthesis and/or cytokine consumption. In an effort to enhance the quantitation of weakly detected cytokines we have developed a unique cell culture-capture ELISA. Lymphocytes are incubated in an anti-cytokine antibody coated ELISA plate for the last 6 hours of a 24 hour in vitro activation period. Use of this cell culture capture method consistently enhanced detection of several T cell cytokines compared to conventional ELISA techniques. Moreover, this technique was found to enhance detection without altering the rate of cytokine secretion which occurred prior to the cell culture capture period. Thus, the cell culture capture ELISA may be useful for detection of a variety of cytokines which are produced at low levels and have traditionally been difficult to quantify.

Zinc attenuates tumor necrosis factor-mediated activation of transcription factors in endothelial cells

OBJECTIVE

The objective of the study was to test the hypothesis that zinc can protect against endothelial dysfunction by interfering with oxidative stress-mediated cellular signaling and subsequent inhibition of an endothelial cell inflammatory response. Our approach was to compare alterations on molecular and biochemical levels with changes in endothelial barrier function that occur in zinc deficient conditions.

METHODS

To investigate our hypothesis, endothelial cells were exposed to zinc deficient media for 2 to 10 days to deplete cellular zinc stores. Following this, half of the groups received zinc supplementation (9.2 microM) for 48 hours. The other half served as zinc deficient controls. These cells were then challenged with tumor necrosis factor-alpha (TNF) for varying time periods. Nuclear extracts were prepared from cells and analyzed for nuclear factor kappa B (NF-kappa B) and activator protein-1 (AP-1) binding. Media from cells were analyzed for interleukin 8 (IL-8) production, and cellular proteins were determined.

RESULTS

Zinc supplementation resulted in a 74% increase in cellular zinc content. It was also shown that a 1.5 hour exposure to TNF (100 U/mL medium) significantly increased NF-kappa B and AP-1 binding, which was lowered considerably when cells were supplemented with physiological levels of zinc. Zinc supplementation also caused a marked attenuation in IL-8 expression by endothelial cells in response to TNF-mediated cell activation.

DISCUSSION

Our previous data clearly show that zinc is a protective and critical nutrient for maintenance of endothelial integrity. The present data suggest that zinc may protect against cytokine-mediated activation of oxidative stress sensitive transcription factors, upregulation of inflammatory cytokines and endothelial cell dysfunction. This may have implications in understanding mechanisms of atherosclerosis.

Metabolically inactive insulin analog prevents type I diabetes in prediabetic NOD mice

The purpose of this study was to determine the relative importance of the metabolic effects of insulin for diabetes prevention by administering insulin or an inactive insulin analog by daily subcutaneous injections to prediabetic mice. A recombinant monomeric human insulin analog, which does not bind to the insulin receptor as a consequence of an alteration of a single amino acid at position 25 of the B chain, was shown to be equally effective at diabetes prevention as was intact insulin. In contrast to native insulin, the insulin analog did not cause hypoglycemia after subcutaneous injection. The insulin analog, however, protected young adult mice from diabetes, even when it was initiated after the onset of extensive lymphocytic infiltration of the islets. Thus, preventative therapy by daily subcutaneous injections of insulin does not require the hypoglycemic response, or binding to the insulin receptor to prevent the onset of type I diabetes.

Rapid screening and treatment for sexually transmitted diseases in arrestees: a feasible control measure

OBJECTIVES

The purpose of this study was to determine the feasibility and usefulness of rapid screening and immediate presumptive treatment for sexually transmitted diseases among arrestees at a county jail.

METHODS

The rapid plasma reagin test (for syphilis) and the urine leukocyte esterase test (for urethritis) were used in establishing routine screening and presumptive treatment for sexually transmitted diseases among arrestees.

RESULTS

Of 4757 arrestees screened, 82 (1.7%) had untreated syphilis, and, of 4174 male arrestees screened, 541 (13%) had a positive leukocyte esterase test. The syphilis prevalence rate was higher among women than among men (3.1% vs 1.5%), and the rate was higher among Blacks than among Whites (2.3% vs 0.7%). Although leukocyte esterase test positivity was higher among persons reporting a urethral discharge (57% vs 12%), 88% of persons with a positive test result did not report such symptoms.

CONCLUSIONS

The program described here has reached persons with sexually transmitted diseases who are unlikely to use traditional health care services and thus are likely to remain untreated. Rapid screening and treatment for sexually transmitted diseases among arrestees is feasible and should be considered in areas with high sexually transmitted disease rates.

Role of T-lymphocytes in the resolution of endotoxin-induced lung injury

An acute neutrophilic lung injury was compared in Balb/c normal and nu/nu (nude) mice to assess the role of T lymphocytes in the resolution of acute pulmonary neutrophilic inflammation following the administration of endotoxin. Maximal neutrophilic infiltration occurred on day 1 post-endotoxin treatment and declined to near normal levels by day 5. In contrast, the percentage of lymphocytes in the bronchoalveolar lavage (BAL) fluid increased from 1.8% on day 1 post-endotoxin to greater than 11% on days three and five, during which time neutrophil resolution was occurring. On days 1-5 after endotoxin administration, approximately 40% of the CD4 lymphocytes expressed the cell surface activation marker, CD69. Despite being CD69+, CD4 cells did not express the high affinity IL-2 receptor chain, CD25, to any significant extent on any of the days studied. To assess the contribution of T cells to the rate of clearance of neutrophils from the BAL, normal and nude Balb/c mice were compared for the percentage of neutrophils following nasal administration of endotoxin. Endotoxin-treated nude mice did not demonstrate significant differences in either the total white blood cell counts or in the clearance of neutrophils from the BAL, as compared to normal Balb/c mice. These data indicate that the influx of activated T cells during the resolution of neutrophilic pneumonitis does not contribute to the rate of neutrophil clearance during acute lung injury.

Pulmonary mechanical and immunologic dysfunction in a murine model of AIDS

Human immunodeficiency virus-infected patients occasionally exhibit alveolar septal wall thickening and decreases in gas diffusion capacity, but the mechanism underlying these abnormalities is unknown. The present study evaluated septal wall thickness and gas exchange properties in a murine model of the acquired immunodeficiency syndrome and determined whether there were alterations in lung lymphocyte deposition and activation that could contribute to changes in respiratory structure and function. Although alveolar septal wall thickness did not differ from control at 1, 2, and 4 wk postimmunosuppressive virus infection, at 8 wk after infection, septal wall thickness was substantially increased. Immunohistochemical evaluation at this time revealed marked increases in the septal wall deposition of fibronectin and collagen type IV. Pulmonary function tests on anesthetized mice with virus-induced septal wall thickening demonstrated that, although total lung capacity, compliance, and functional residual capacity were unaltered, diffusion capacity for carbon monoxide was significantly impaired. A diffuse nonspecific interstitial pneumonitis was present in lungs of immunodeficient mice, and flow cytometry indicated that both lymphocytes and macrophages were activated. Reverse transcriptase-polymerase chain reaction analysis of lung lymphocytes demonstrated enhanced mRNA expression for several cytokines known to affect lung structure. These results show that impaired gas exchange occurs in a murine model of acquired immunodeficiency syndrome and suggest that such alterations may be mediated by elaboration of cytokines from activated lung lymphocytes and macrophages.

Pulmonary lymphoid cell activation and cytokine expression in murine AIDS-associated interstitial pneumonitis

Limited information is available about the pathogenesis of acquired immune deficiency syndrome (AIDS)-associated idiopathic interstitial pneumonitis, a common noninfectious complication of human immunodeficiency virus (HIV) infection. Infection of C57B1/6 mice with LP-BM5 retrovirus, a murine model of AIDS, leads to development of a diffuse interstitial pneumonitis that displays many features of human AIDS-associated interstitial pneumonitis. To further characterize the cellular and molecular features of this lung disease, the temporal development of cellular infiltration, cytokine expression, and virus replication were evaluated in lung tissue of virus-infected mice. Persistent expression of viral RNA was detectable in lungs as early as 1 wk after infection. Infiltration of the lungs by CD4+ and CD8+ T cells, by IgG+ and IgA+ B cells, and by macrophages was observed by 4 wk after infection and continued through 8 wk of infection. Histologically, cellular infiltration was most pronounced in peribronchial and perivascular regions, whereas inflammation of alveolar septae and alveolar spaces was minimal. In contrast to normals, T cells from infected lungs were immunodeficient in that they failed to proliferate in response to the mitogen concanavalin A (ConA). However, evaluation of cytokine mRNA expression by interstitial lung lymphoid cells indicated that cells from infected lungs were chronically activated, in that elevated expression of interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) was observed throughout the course of infection. Similarly, expression by interstitial lung lymphoid cells of mRNA for the proinflammatory cytokine IL-1 and the fibrogenic cytokine transforming growth factor-beta (TGF-beta) was also increased following infection. These results indicate that retrovirus-induced immunodeficiency in mice is associated with infiltration and chronic activation of lymphoid cells in the lungs. Furthermore, simultaneous expression of IL-10, IFN-gamma, and TGF-beta suggests that cytokine-expressing cells in infected lungs may be unresponsive to inhibitory and antiinflammatory effects of IL-10 and/or TGF-beta, thus contributing to chronicity of inflammation in this disorder.

Parenting styles, adolescent substance use, and academic achievement

This article investigates how children and their parents rate their parenting styles, and how this rating is associated with academic achievement, alcohol, and tobacco use. We surveyed students and their parents in two public school districts. A total of 386 matched parent-child pairs from eighth- and ninth-grade students were analyzed for parent and student classification of parents as authoritative, authoritarian, permissive, or mixed parenting styles. Agreement on parenting styles between parents and children was poor. Students perceived parents as less authoritative, less permissive and more authoritarian than parents considered themselves. High grades were associated with child and parent perception of higher authoritativeness, lower permissiveness, and lower authoritarianism. Child tobacco and alcohol use was associated with child perception of lower authoritativeness, and higher permissiveness while parent perception of parenting style was not associated with child substance use. This study provides further evidence that parenting styles and adolescents' perceptions of them are associated with child achievement and substance use. While we cannot determine whether child or parent perception of parenting style is more accurate, child perception is more strongly associated with grades and substance use than is parent perception. It is likely that parents would benefit from understanding how they are perceived by their children.

Defective CD4+ T cell signaling in murine AIDS: uncoupling of the T cell receptor complex from PIP2 hydrolysis

CD4+ T cells from mice with murine AIDS (MAIDS) have been shown to be unable to respond to TCR stimulation as measured by proliferation, IL-2 production, or IL-2R upregulation, although responsiveness was restored with PMA and ionomycin. In this report we have demonstrated that the inability of MAIDS CD4+ T cells to respond to CD3 stimulation was not associated with reduced surface expression of CD3, CD4, or CD28 and could not be overcome by costimulation with anti-CD28 antibody. However, MAIDS CD4+ T cells failed to activate the PIP2 hydrolysis pathway efficiently, resulting in diminished IP3 production and reduced Ca2+ mobilization compared to normal controls. Additionally, TCR signaling in MAIDS resulted in a reduction in the level of tyrosine phosphorylation of some proteins including deficient tyrosine phosphorylation of PLC-gamma 1, compared to normal CD4+ T cells. These studies suggest that stimulation through the TCR in CD4+ T cells from MAIDS-infected mice is uncoupled from the phosphotidylinositol hydrolysis pathway due to deficient activation of PLC-gamma 1.

Liver endogenous antioxidant defenses in mice fed AIN-76A diet and infected with murine AIDS

The effects of murine AIDS infection on endogenous antioxidant defenses in mice fed the AIN-76A liquid diet were investigated. C57BL/6 female mice were divided into 2 groups: one group was injected interperitoneally with LP-BM5 murine retrovirus (MAIDS) stock, and the other group served as the non-infected control. Two weeks after the infection, the mice were killed and livers were excised for biochemical analysis of the antioxidant defenses. Liver reduced glutathione (GSH) levels and activities of both cytosolic superoxide dismutase (SOD) and mitochondrial SOD were significantly depressed by MAIDS infection. Activities of glutathione reductase (GR) selenium (Se)-dependent glutathione peroxidase (GPx), catalase and glutathione-S-transferase (GST) toward 1-chloro-2,4-dinitrobenzene (CDNB) were not affected by MAIDS infection. A previous study by this laboratory using the Lieber-DeCarli (L-D) all purpose liquid diet caused a decline in total SOD activity and GPx activity, but not GSH levels. The results suggest that MAIDS infection depresses liver antioxidant defenses; however, MAIDS infection of mice fed the AID-76A liquid diet depresses different liver antioxidant defense parameters when compared to those of the mice fed the L-D all purpose liquid diet.

Liver antioxidant defenses in mice fed ethanol and the AIN-76A diet

The effects of chronic alcohol (EtOH) ingestion on antioxidant defenses in mice fed AIN-76A liquid diets were investigated. C57Bl/6 female mice were divided into three groups and fed the AIN-76A liquid EtOH diet containing EtOH to provide 31% of total caloric intake (TCI), the same basic diet containing EtOH to provide 35% of TCI, or an isocaloric AIN-76A liquid control diet. After 3 weeks, the mice were killed and livers were excised for biochemical analysis. Liver reduced glutathione (GSH) levels, and activities of both Mn-superoxide dismutase (SOD) and Cu/Zn-SOD were significantly decreased by both levels of EtOH. Activities of catalase and glutathione transferase (GT) were significantly increased, whereas glutathione peroxidase (GP) activity was not affected by either level of EtOH. Our previous study using the Lieber-DeCarli liquid EtOH diet caused a decline of total SOD and GP activities. The results suggest that chronic EtOH administration decreases liver antioxidant defenses; however, the mice fed the AIN-76A EtOH liquid diet can maintain a higher antioxidant defense capability than those fed Lieber-DeCarli EtOH liquid diet.

Ethanol as a possible cofactor in the development of murine AIDS

Chronic ethanol (EtOH) abuse in humans leads to a variety of immunomodulatory events that can alter resistance to a number of infectious agents. Whether alcohol abuse affects the susceptibility to human immunodeficiency virus infection or the subsequent development of acquired immune deficiency syndrome (AIDS) is a matter of extreme importance; however, available information in humans or animal models is limited. The goal of this study was to evaluate the effect of chronic EtOH feeding in mice on the development of immunodeficiency in the murine model of AIDS (MAIDS). C57BI/6 mice were placed on the Lieber-DeCarli liquid EtOH diet (25% or 31% total caloric intake) or a nutrient-matched isocaloric liquid control diet. Seven days later, mice were infected with the LP-BM5 murine leukemia virus mixture, and groups of infected and noninfected mice were assayed at defined time points postinfection for antigen-specific and nonspecific immune responses. In the absence of retroviral infection, chronic EtOH feeding (5-8 weeks) led to reductions in spleen weights, compared with isocaloric controls. In spite of reduced spleen size, mitogenic responses of spleen cells to concanavalin A (ConA) and lipopolysaccharide (LPS) were elevated in EtOH-fed mice, as compared with mice fed the control diet. Chronic EtOH feeding also enhanced the allogeneic mixed lymphocyte response and increased antigen-specific priming of both B-cells and CD4+ T-cells to the antigen, sheep red blood cells. In MAIDS-infected mice, chronic EtOH feeding delayed but did not prevent the onset of virus-induced immunodeficiency and MAIDS-induced autoantibody synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro tumor necrosis factor cytotoxicity in Hep G2 liver cells

Tumor necrosis factor-alpha (TNF-alpha) is a mediator of liver injury. The objective of this study was to develop an in vitro model of TNF-mediated liver cell injury using the Hep G2 cell line. Hep G2 cells normally are insensitive to TNF cytotoxicity, but they were rendered susceptible, or sensitized, to TNF cytotoxicity by inhibitors of RNA and protein synthesis. The concentration of TNF required to kill 50% of Hep G2 cells sensitized with 0.8 mumol/L actinomycin D (Act D) was 35 pmol/L compared with 5 pmol/L for LM fibroblasts, a classic target cell used in TNF cytotoxicity bioassays. Similarly, TNF cytotoxicity occurred in Hep G2 cells sensitized with cycloheximide (CHX), and cytotoxicity to both inhibitors was dose dependent. Both protein and RNA synthesis were inhibited in Hep G2 cells by the concentrations of CHX and Act D associated with TNF cytotoxicity. Hep G2 cells pretreated with TNF alone and later exposed to normally toxic concentrations of TNF with DACT did not develop cytotoxicity. Thus, in vitro tolerance to TNF was induced. Cytotoxicity also was more severe at modestly increased temperatures (39 degrees C versus 37 degrees C), which may have clinical relevance to hepatic decompensation during febrile episodes. We suggest that the Hep G2 cell line sensitized by inhibiting RNA and protein synthesis is a useful in vitro model for evaluating mechanism(s) of TNF-mediated liver cell injury.

Halachic perspective on involuntary psychiatric care of the mentally ill

According to most mental health statutes in force around the world, doctors may involuntarily treat only acutely psychotic patients who present some danger to themselves, others or property. Chronic patients who, owing to volitional or cognitive defects, present a similar danger may not be thus treated. This may cause situations to arise where dangerous chronically ill patients who refuse treatment may cause serious harm because of physicians' inability to treat them. This article suggests changes to contemporary mental health statutes, in line with Judaic Halachic codes, which view all mentally ill patients as potentially harmful, and require physicians to treat--voluntarily or involuntarily--all mentally ill persons.

Parent participation in an adolescent drug abuse prevention program

This study reports the level of participation of parents in a parent-targeted school-based drug prevention program, the differences between students whose parents participate and those who don't, and the implications for involving parents in future drug prevention programs. Among 1761 eligible seventh grade families, 1263 students (72%) and 1142 parents (65%) completed surveys assessing the quality of parent-child relationships as well as tobacco and alcohol use. Ten percent of eligible families attended at least one of the evening sessions. Compared to students whose parents completed the survey, students whose parents did not complete a survey were more likely to report they used tobacco, had more friends who used substances, were monitored less by their parents, had more risk-taking behaviors, had lower grade-point averages, and their parents had higher rates of tobacco and alcohol use. Parents who attended evening sessions had the lowest rates of tobacco use and reported spending the most time with their children. Parent-targeted drug preventions programs may stigmatize attending parents and may be unlikely to attract the highest risk families.

Regulation of B cell:T cell interactions: potential involvement of an endogenous B cell sialidase

In light of the ability of B cells treated with neuraminidase to interact more effectively with T cells, the increased capacity of activated, but not small resting B cells, to interact with T cells could be associated with the level of sialylation on certain B cell surface molecules which influences the effectiveness of the physical interaction between B and T cells. The purpose of this study was to determine if activation of B cells altered sialylation via an endogenous sialidase which affected both the initial interaction between T and B cells and subsequent B cell-induced T cell proliferation. The competitive neuraminidase inhibitor, 2-deoxy-2,3-dehydro-N-acetylneuraminic acid (NeuAc2en), inhibited LPS-mediated enhancement of B cell conjugate formation with Ia-specific T cell clones as well as enhancement of their capacity to stimulate a mixed lymphocyte reaction. The addition of NeuAc2en during LPS stimulation did not affect the surface expression of Ia, LFA-1, ICAM-1 or mB7, suggesting that inhibition of LPS-mediated enhancement by the sialidase inhibitor was not due to changes in the level of expression of the major B cell adhesion or co-stimulatory molecules. Short term stimulation with phorbol myristate acetate (PMA) and ionomycin also enhanced the ability of resting B cells to form antigen specific T:B conjugates. However, activation of B cells with PMA and ionomycin or with LPS did not change the capacity of a sialic acid specific lectin to bind to the B cells, suggesting that activation was not associated with global changes in surface sialic acid content. B cell stimulation did not appear to increase the activity of the most prevalent B cell sialidase activity as measured in an in vitro assay system, suggesting that the major B cell sialidase may not be responsible for the alteration of B cell sialylation levels or the ability of activated B cells to interact more effectively with T cells. The possibility of intracellular compartmentalization of sialidase activity or that a minor B cell sialidase may play a role in the regulation of a B cells ability to interact with T cells are discussed.

Parenting behaviors and the onset of smoking and alcohol use: a longitudinal study

OBJECTIVE

To identify which specific parenting behaviors are associated with the onset of alcohol and tobacco use and how they are associated.

DESIGN

Prospective cohort study of two groups of preadolescents surveyed annually, the first group for 4 years, the second for 3 years.

SETTING

Two public school districts in Southern California.

SUBJECTS

1034 fifth graders and 1266 seventh graders began the study after obtaining parental consent to complete surveys in a classroom setting. By the last measurement, attrition was 37 and 38% for the two cohorts, respectively.

MAIN OUTCOME MEASURES

The onset of tobacco or alcohol use in the last month.

RESULTS

Children who reported that parents spent more time with them and communicated with them more frequently had lower onset rates of using alcohol and tobacco in the last month. These parental interactions lead to more positive relationships with their children. Parental monitoring and positive relations were protective factors for disruptive behavior and the selection of substance-using friends. Disruptive behavior increased the odds of adolescents drinking in the last month approximately twofold and of smoking in the last month two to fourfold.

CONCLUSIONS

This study provides further evidence that parenting behaviors are significant precursors to adolescent disruptive behavior, vulnerability to peer pressure, and subsequent substance use. Parents should be targeted in future substance use prevention programs, before their children reach adolescence.

Pulmonary hypertension in a murine model of the acquired immunodeficiency syndrome

Rapidly accumulating evidence suggests that a proportion of patients with acquired immunodeficiency syndrome (AIDS) develop hypertensive pulmonary vascular disease reminiscent of primary pulmonary hypertension. As an initial step to explore the link between AIDS and hypertensive pulmonary vascular disease, the present study determined whether pulmonary hypertension is present in a well-characterized murine model of retrovirus-induced immunodeficiency. In agreement with previous reports, mice infected with the LP-BM5 murine leukemia virus developed polyclonal B and T cell activation followed by progressive and severe B and T cell immunodeficiency. At 12 wk postinfection, when persistent immunodeficiency was established, mice were anesthetized, and right ventricular systolic pressure was determined in open-chest, mechanically ventilated animals. Mean right ventricular systolic pressure was 14.7 +/- 1.3 mm Hg in control animals and was increased significantly to 22.5 +/- 3.2 mm Hg in virus-infected mice. Right ventricular hypertrophy was also present in infected mice as evidenced by a 27% increase in the ratio of right to left ventricular weights; there were no group-dependent differences in the left ventricular to total-body weight ratio. Morphometric evaluation indicated that medial thickness in muscularized pulmonary arteries, expressed as a percentage of the external diameter, was 9.6 +/- 0.4% in control lungs and increased to 14.4 +/- 0.5% in lungs from infected animals. Qualitative histopathologic analysis suggested increased perivascular collagen deposition in lungs from infected animals relative to control animals. Unlike AIDS patients with pulmonary hypertension, infected mice did not exhibit plexiform lesions or intimal fibrosis of the pulmonary arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanism of differential regulation of IL-2 in murine Th1 and Th2 T cell subsets. 1. Induction of IL-2 transcription in Th2 cells by up-regulation of transcription factors with the protein synthesis initiation factor 4E

Regulation of IL-2 gene expression in response to receptor-mediated stimuli is known to be mediated primarily by the IL-2 transcriptional enhancer and multiple transcription factors. However, the mechanism that controls the differential expression of the IL-2 gene in both human and murine CD4+ Th cell subsets (Th1-IL-2+ and Th2-IL-2-) is not clearly understood. Differential IL-2 gene expression was assessed in murine Th1 and Th2 subsets by analyzing the expression of a Escherichia coli lacZ reporter gene under control of the human IL-2 enhancer (IL2ZH) transfected in both T cell subsets. Stimulation of transfected T cells with the mitogen Con A, anti-CD3 Ab, or PMA plus ionomycin activated the IL2ZH construct in Th1 but not Th2 cells. However, IL2ZH was activated in stimulated Th2 cells that were co-transfected with a vector that overexpressed the eukaryotic initiation factor 4E (eIF-4E). It has been shown that eIF-4E is rate limiting for protein synthesis and its overexpression leads to increased rates of protein synthesis. Hence, eIF-4E overexpression could have overcome a deficiency in transcriptionally active levels of IL-2 regulatory factors in Th2 cells leading to IL-2 enhancer activation. This possibility was supported by demonstrating that transcriptionally active levels of the critical IL-2 transcription factor, nuclear factor of activated T cells (NF-AT), occurred only in Th2 cells overexpressing eIF-4E but not in normal Th2 cells, thus indicating that the inability of Th2 cells to express IL-2 was associated with inadequate levels of at least one transcription factor, NF-AT. Moreover, these results were confirmed by the observation that eIF-4E overexpression augmented NF-AT binding activity in Th2 cells. These data suggest that concentrations of inducible transcription factors are a major component of the regulatory mechanisms dictating IL-2 expression and may be under translational control in Th1/Th2 T cell subsets.

Mechanism of differential regulation of IL-2 in murine Th1 and Th2 T cell subsets. 1. Induction of IL-2 transcription in Th2 cells by up-regulation of transcription factors with the protein synthesis initiation factor 4E

Regulation of IL-2 gene expression in response to receptor-mediated stimuli is known to be mediated primarily by the IL-2 transcriptional enhancer and multiple transcription factors. However, the mechanism that controls the differential expression of the IL-2 gene in both human and murine CD4+ Th cell subsets (Th1-IL-2+ and Th2-IL-2-) is not clearly understood. Differential IL-2 gene expression was assessed in murine Th1 and Th2 subsets by analyzing the expression of a Escherichia coli lacZ reporter gene under control of the human IL-2 enhancer (IL2ZH) transfected in both T cell subsets. Stimulation of transfected T cells with the mitogen Con A, anti-CD3 Ab, or PMA plus ionomycin activated the IL2ZH construct in Th1 but not Th2 cells. However, IL2ZH was activated in stimulated Th2 cells that were co-transfected with a vector that overexpressed the eukaryotic initiation factor 4E (eIF-4E). It has been shown that eIF-4E is rate limiting for protein synthesis and its overexpression leads to increased rates of protein synthesis. Hence, eIF-4E overexpression could have overcome a deficiency in transcriptionally active levels of IL-2 regulatory factors in Th2 cells leading to IL-2 enhancer activation. This possibility was supported by demonstrating that transcriptionally active levels of the critical IL-2 transcription factor, nuclear factor of activated T cells (NF-AT), occurred only in Th2 cells overexpressing eIF-4E but not in normal Th2 cells, thus indicating that the inability of Th2 cells to express IL-2 was associated with inadequate levels of at least one transcription factor, NF-AT. Moreover, these results were confirmed by the observation that eIF-4E overexpression augmented NF-AT binding activity in Th2 cells. These data suggest that concentrations of inducible transcription factors are a major component of the regulatory mechanisms dictating IL-2 expression and may be under translational control in Th1/Th2 T cell subsets.

Tactile activity in primate primary somatosensory cortex during active arm movements: correlation with receptive field properties

1. Five hundred ninety-five single neurons with tactile receptive fields (RFs) on the contralateral arm were isolated in the primary somatosensory cortex (SI) of awake, behaving monkeys. 2. Fifty-eight percent of the tactile cells showed significantly different levels of activity during active movements of the arm in eight directions or during active maintenance of the arm over the target endpoints. 3. The discharge of many of the active tactile cells was unimodally tuned with movement direction and the pattern of the tactile population activity varied in a meaningful fashion with arm movement direction and posture. 4. The intensity of the arm-movement-induced activity was typically less than that evoked by direct tactile stimulation of the cell's RF. 5. The probability of task-related activity was correlated with certain RF properties, in particular the sensitivity of the cell to lateral stretch of the skin and to passive arm movements that avoided direct contact of the RF on any surface. 6. This suggests that task-related activity results mainly from the activation of tactile receptors by mechanical deformation of the skin as the arm changes geometry during movement. 7. These results demonstrate that tactile activity containing potential proprioceptive information is generated in SI during active arm movements that avoid direct contact of the skin with external surfaces. Whether or not this input contributes to the kinesthetic sensations evoked by the movements cannot be resolved by this study.

Tactile activity in primate primary somatosensory cortex during active arm movements: cytoarchitectonic distribution

1. Cells were recorded in areas 3b and 1 of the primary somatosensory cortex (SI) of three monkeys during active arm movements. Successful reconstructions were made of 46 microelectrode penetrations, and 298 cells with tactile receptive fields (RFs) were located as to cytoarchitectonic area, lamina, or both. 2. Area 3b contained a greater proportion of cells with slowly adapting responses to tactile stimuli and fewer cells with deep modality inputs than did area 1. Area 3b also showed a greater level of movement-related modulation in tactile activity than area 1. Other cell properties were equally distributed in the two areas. 3. The distribution of cells with low-threshold tactile RFs that also responded to lateral stretch of the skin or to passive arm movements was skewed toward deeper laminae than for tactile cells that did not respond to those manipulations. 4. The variation of activity of tactile neurons during arm movements in different directions was weaker in the superficial laminae than in deeper cortical laminae. 5. Cells with only increases in activity during arm movements were preferentially but not exclusively located in middle and superficial layers. Cells with reciprocal responses were found mainly in laminae III and V, whereas cells with only decreases in activity were concentrated in lamina V. 6. Overall, active arm movements evoke directionally tuned tactile and "deep" activity in areas 3b and 1, in particular in the deeper cortical laminae that are the source of the descending output pathways from SI.