Dietary patterns of women smokers and non-smokers

The 1-day food intakes of 1,338 women, aged 19 to 50, who were respondents in the 1985 Continuing Survey of Food Intake by Individuals, were studied. The energy, nutrient, and food intake patterns of smokers, those how had quit smoking, and those who had never smoked cigarettes were compared. Mean energy intakes of smokers (1,627 kcal), those who had never smoked (1,620 kcal), and those who had quit at least 1 year before the interview (1,719 kcal) were not significantly different. Self-reported body weight was significantly different between never-smokers and smokers (p less than .01) and quitters (p less than .05) only for the oldest category of women (ages 41 to 50 years). The consumption of fruits (p less than .001) and vegetables (p less than .01) was significantly lower and the intake of eggs (p less than .01), sugars (p less than .001), regular carbonated soft drinks (p less than .01), coffee (p less than .001), and alcoholic beverages (p less than .001) was significantly higher for women smokers than for non-smokers. After controlling through regression analysis for physical activity, health status, and demographic characteristics, we found that smokers, compared with never-smokers, had significantly lower protein (p less than .04), dietary fiber (p less than .001), vitamin C (p less than .001), and thiamin (p less than .01) intakes and higher cholesterol (p less than .02) intakes per 1,000 kcal.     

Dentin stresses in post-reconstructed teeth with diminishing bone support

Dentin stresses from simulated functional loads to post-reinforced tooth models with four levels of periodontal support were calculated using finite element analysis. As bone levels diminished, stresses were found to increase dramatically and to concentrate in the small amount of dentin remaining near the post apex.     

Possible non-sexual transmission of genital human papillomavirus infections in young women

Human papillomaviruses were detected by an in vitro enzymatic DNA amplification method in cells obtained from vulvar swabs of 9 of 61 (14.8 %) young women without prior experience of sexual intercourse and in 7 of 57 (12.3 %) young women with prior experience. The prevalence of human papillomavirus DNA in these two groups of women was not significantly different (x²=0.16, p>0.5; 95 % confidence interval –0.165 to 0.215). These results suggest that genital human papillomavirus is not sexually transmitted in all cases and that it may be acquired by modes other than sexual contact.     

Detection of human papillomaviruses in exfoliated cervicovaginal cells by in situ DNA hybridization analysis.

A total of 851 specimens of exfoliated cervicovaginal cells and 27 specimens of male urethral smears obtained from 706 individuals with various clinical findings were examined for the presence of human papillomavirus (HPV) types 6, 11, 16, 18, 31, and 33 by in situ DNA hybridization analysis. The nonradioactive DNA in situ hybridization method used in this study showed no detectable cross-hybridization either among different types of HPV (except between types 6 and 11) or between HPV DNA and human cellular DNA. Furthermore, this system was found to be more sensitive than the Southern blotting method in detecting HPV. HPV was found in 233 of 276 (84.4%) and in 34 of 47 (72.3%) samples of cervicovaginal cells from patients with urogenital condylomata and cervical dysplasia, respectively. HPV was also detected in 6 of 39 (15.4%) women with normal cytological findings who were also symptom-free. Young women who were at low risk but were infected with HPV showed significantly reduced ratios of helper-inducer T lymphocytes to suppressor-cytotoxic T lymphocytes compared with those of uninfected normal controls (1.28 +/- 0.31 versus 2.47 +/- 0.64; P less than 0.001). This in situ DNA hybridization method can have broad application to the screening of HPV in early lesions and in normal-looking tissues and may be used to identify patients at risk of more serious or possibly malignant progression.     

Defining clinically relevant molecular subsets of lung cancer

The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), gefitinib and erlotinib, induce dramatic responses in certain patients with non-small cell lung cancer (NSCLC). As such, the drugs provide an unexpected tool to dissect clinically relevant molecular subsets of NSCLC. For example, using mutational profiling of tumor DNA from patients with sensitivity, primary resistance, and secondary resistance to these agents, we and others have demonstrated that somatic mutations in the tyrosine kinase domain of EGFR are associated with sensitivity to gefitinib and erlotinib, while mutations in KRAS, which encodes a GTPase downstream of EGFR, are associated with primary resistance. Furthermore, second site mutations in the EGFR kinase domain are commonly found in patients with acquired resistance. We are now using a variety of molecular and biological approaches to help further define molecular subsets of lung cancer that have relevance in the clinic.     

A phase I/II study of weekly high-dose erlotinib in previously treated patients with nonsmall cell lung cancer

BACKGROUND: Preclinical studies have suggested that erlotinib at high doses may inhibit additional sites downstream of the epidermal growth factor receptor (EGFR), resulting in greater antitumor efficacy. The objective of this study was to determine the tolerability and efficacy of high-dose erlotinib administered on a weekly schedule to patients with advanced nonsmall cell lung cancer (NSCLC). METHODS: The authors conducted a Phase I/II trial of weekly erlotinib in patients with progressive NSCLC who had received previous chemotherapy. In the Phase I portion, patients were enrolled in 3-patient cohorts at erlotinib dose levels of 1200 mg, 1600 mg, and 2000 mg once weekly. The Phase II portion was designed to determine the major objective response rate of the dose identified in the Phase I portion of the trial. RESULTS: Twenty-seven patients were enrolled. No dose-limiting toxicity was observed. Grade 1 and 2 rash and diarrhea were the principle toxicities, and each occurred in 92% of patients. Among 21 patients who were treated at the Phase II dose of 2000 mg weekly, a single objective response was identified, yielding a response rate of 5% (95% confidence interval, 0.2-22%). For this cohort, the median survival was 9.5 months. The sole radiographic response occurred in a patient whose pretreatment tumor specimen harbored an EGFR exon 19 deletion. CONCLUSIONS: Erlotinib at a dose of 2000 mg administered weekly was tolerated well by these patients with advanced NSCLC. The 5% objective response rate did not reach the stated objective at the interim efficacy analysis, prompting the closure of the study.     

Shp1 regulates T cell homeostasis by limiting IL-4 signals

The protein-tyrosine phosphatase Shp1 is expressed ubiquitously in hematopoietic cells and is generally viewed as a negative regulatory molecule. Mutations in Ptpn6, which encodes Shp1, result in widespread inflammation and premature death, known as the motheaten (me) phenotype. Previous studies identified Shp1 as a negative regulator of TCR signaling, but the severe systemic inflammation in me mice may have confounded our understanding of Shp1 function in T cell biology. To define the T cell–intrinsic role of Shp1, we characterized mice with a T cell–specific Shp1 deletion (Shp1^fl/fl CD4-cre). Surprisingly, thymocyte selection and peripheral TCR sensitivity were unaltered in the absence of Shp1. Instead, Shp1^fl/fl CD4-cre mice had increased frequencies of memory phenotype T cells that expressed elevated levels of CD44. Activation of Shp1-deficient CD4⁺ T cells also resulted in skewing to the Th2 lineage and increased IL-4 production. After IL-4 stimulation of Shp1-deficient T cells, Stat 6 activation was sustained, leading to enhanced Th2 skewing. Accordingly, we observed elevated serum IgE in the steady state. Blocking or genetic deletion of IL-4 in the absence of Shp1 resulted in a marked reduction of the CD44^hi population. Therefore, Shp1 is an essential negative regulator of IL-4 signaling in T lymphocytes.T cells are characterized by their ability to expand dramatically in an antigen-specific manner during an immune challenge. After an initial immune response, a small proportion of responding T cells survive and give rise to memory cells (Bruno et al., 1996). Memory T cells express elevated levels of CD44 and can be divided further into central-memory (CD62L^hi CCR7^hi) and effector-memory (CD62L^lo CCR7^lo) compartments. However, not all T cells that display the phenotype of memory cells are the product of a classical antigen-specific immune response (Sprent and Surh, 2011). For example, such cells are found in unimmunized mice, including those raised in germ-free and antigen-free conditions (Dobber et al., 1992; Vos et al., 1992). The precise ontogeny of such cells remains elusive, although several mechanisms by which naive cells can adopt a memory phenotype have been characterized. Naive T cells introduced into lymphopenic environments adopt a memory phenotype through a process of homeostatic proliferation in response to IL-7 and MHC (Goldrath et al., 2000; Murali-Krishna and Ahmed, 2000). Additionally, increased production of IL-4 has been linked to the development of memory phenotype–innate T cell populations in studies of several knockout mouse models (Lee et al., 2011).The T cell response is tightly regulated by the balance of phosphorylation and dephosphorylation of intracellular signaling molecules. Shp1 (encoded by Ptpn6) is a protein tyrosine phosphatase expressed ubiquitously in hematopoietic cells and has been broadly characterized as a negative regulator of immune cell activation (Pao et al., 2007a; Lorenz, 2009). The physiological relevance of Shp1 as a key negative regulator of the immune response is illustrated by the motheaten (me) and motheaten viable (me^v) mutations, which ablate Shp1 expression or greatly reduce Shp1 activity, respectively (Shultz et al., 1993; Tsui et al., 1993). Homozygous me/me or me^v/me^v mice (hereafter, referred to collectively as me mice) suffer from severe systemic inflammation and autoimmunity, which result in retarded growth, myeloid hyperplasia, hypergammaglobulinemia, skin lesions, interstitial pneumonia, and premature death. More recently, a study has identified a third allele of Ptpn6, named spin, which encodes a hypomorphic form of Shp1 (Croker et al., 2008). Mice homozygous for spin develop a milder autoimmune/inflammatory disease that is ablated in germ-free conditions.Shp1 has been implicated in signaling from many immune cell surface receptors (Zhang et al., 2000; Neel et al., 2003), including the TCR (Plas et al., 1996; Lorenz, 2009), BCR (Cyster and Goodnow, 1995; Pani et al., 1995), NK cell receptors (Burshtyn et al., 1996; Nakamura et al., 1997), chemokine receptors (Kim et al., 1999), FAS (Su et al., 1995; Takayama et al., 1996; Koncz et al., 2008), and integrins (Roach et al., 1998; Burshtyn et al., 2000). Shp1 also has been demonstrated to regulate signaling from multiple cytokine receptors by dephosphorylating various Jak (Klingmüller et al., 1995; Jiao et al., 1996; Minoo et al., 2004) and/or Stat (Kashiwada et al., 2001; Xiao et al., 2009) molecules. Several of these cytokines are pertinent to T cell biology. For example, Stat 5 is an essential mediator of signals from IL-2 and IL-7 (Rochman et al., 2009). IL-4 signaling results in Stat 6 phosphorylation and has potent Th2 skewing effects. Additionally, IL-4 has mitogenic effects on CD8⁺ T cells (Rochman et al., 2009). Notably, mutation of the immunoreceptor tyrosine-based inhibitory motif (ITIM) in IL-4Rα results in ablation of Shp1 binding and hypersensitivity to IL-4 stimulation (Kashiwada et al., 2001), implicating Shp1 as a regulator of this cytokine receptor.Although development of the me phenotype does not require T cells (Shultz, 1988; Yu et al., 1996), several aspects of T cell biology reportedly are controlled by Shp1 (Lorenz, 2009). Most previous studies that examined the role of Shp1 in T cells used cells derived from me/me or me^v/me^v mice (Carter et al., 1999; Johnson et al., 1999; Zhang et al., 1999; Su et al., 2001) or cells expressing a dominant-negative allele of Shp1 (Plas et al., 1996, 1999; Zhang et al., 1999). Several such reports have concluded that Shp1 negatively regulates the strength of TCR signaling during thymocyte development and/or peripheral activation (Carter et al., 1999; Johnson et al., 1999; Plas et al., 1999; Zhang et al., 1999; Su et al., 2001). Despite the large number of studies that implicate Shp1 in control of TCR signaling, there is no consensus on which component of the TCR signaling cascade is targeted by the catalytic activity of Shp1. Suggested Shp1 targets downstream of T cell activation include TCR-ζ (Chen et al., 2008), Lck (Lorenz et al., 1996; Stefanová et al., 2003), Fyn (Lorenz et al., 1996), ZAP-70 (Plas et al., 1996; Chen et al., 2008), and SLP-76 (Mizuno et al., 2005). Shp1 also is implicated in signal transduction downstream of several immune inhibitory receptors that negatively regulate T cell activity, such as PD-1 (Chemnitz et al., 2004), IL-10R (Taylor et al., 2007), CEACAM1 (Lee et al., 2008), and CD5 (Perez-Villar et al., 1999).The severe inflammation characteristic of the me phenotype might have confounded studies examining the cell-intrinsic role of Shp1 in various hematopoietic cell types. We previously generated a floxed Shp1 allele that facilitates analysis of the role of Shp1 in various lineages (Pao et al., 2007b). Previous studies have used this approach to study the role of Shp1 in T cells during antiviral and antitumor immune responses, respectively (Fowler et al., 2010; Stromnes et al., 2012). However, a more fundamental analysis of the cell-intrinsic role of Shp1 during T cell development, homeostasis, and activation has not been reported. Here, we provide evidence that a major role for Shp1 in T cells is to maintain normal T cell homeostasis through negative regulation of IL-4 signaling.     

A sandwich ELISA for phosphoglycerate kinase

Phosphoglycerate kinase (PGK1) is a key enzyme in glycolysis that can also be released from certain cells. In the extracellular milieu, PGK1 reportedly acts as a disulphide reductase to activate plasmin, resulting in the production of angiostatin, a potent angiogenesis inhibitor. Certain cancer cell lines secrete unusually large amounts of PGK1, raising the possibility that serum PGK1 levels can be used to screen for cancer. To facilitate the characterization of the PGK1 secretory pathway and to monitor serum levels of PGK1, we have developed a sensitive sandwich ELISA using an immuno-affinity-purified chicken polyclonal antibody for capturing PGK1 and an immuno-affinity-purified rabbit polyclonal antibody for detecting it. The assay is about 10-fold more sensitive than other reported PGK1 ELISAs. We used the ELISA to quantify the amount of PGK1 released from HeLa cells and PGK1 serum levels in cancer patients. Of 10 cancer patients whose serum was tested, 3 of 4 with pancreatic cancer had 65-900% higher levels of PGK1 than that found in normal serum.