MNK Inhibition Sensitizes KRAS-Mutant Colorectal Cancer to mTORC1 Inhibition by Reducing eIF4E Phosphorylation and c-MYC Expression

KRAS-mutant colorectal cancers are resistant to therapeutics, presenting a significant problem for ∼40% of cases. Rapalogs, which inhibit mTORC1 and thus protein synthesis, are significantly less potent in KRAS-mutant colorectal cancer. Using Kras-mutant mouse models and mouse- and patient-derived organoids, we demonstrate that KRAS with G12D mutation fundamentally rewires translation to increase both bulk and mRNA-specific translation initiation. This occurs via the MNK/eIF4E pathway culminating in sustained expression of c-MYC. By genetic and small-molecule targeting of this pathway, we acutely sensitize KRASG12D models to rapamycin via suppression of c-MYC. We show that 45% of colorectal cancers have high signaling through mTORC1 and the MNKs, with this signature correlating with a 3.5-year shorter cancer-specific survival in a subset of patients. This work provides a c-MYC-dependent cotargeting strategy with remarkable potency in multiple Kras-mutant mouse models and metastatic human organoids and identifies a patient population that may benefit from its clinical application. SIGNIFICANCE: KRAS mutation and elevated c-MYC are widespread in many tumors but remain predominantly untargetable. We find that mutant KRAS modulates translation, culminating in increased expression of c-MYC. We describe an effective strategy targeting mTORC1 and MNK in KRAS-mutant mouse and human models, pathways that are also commonly co-upregulated in colorectal cancer.This article is highlighted in the In This Issue feature, p. 995.

mTORC1 promotes TOP mRNA translation through site-specific phosphorylation of LARP1

LARP1 is a key repressor of TOP mRNA translation. It binds the m7Gppp cap moiety and the adjacent 5'TOP motif of TOP mRNAs, thus impeding the assembly of the eIF4F complex on these transcripts. mTORC1 controls TOP mRNA translation via LARP1, but the details of the mechanism are unclear. Herein we elucidate the mechanism by which mTORC1 controls LARP1's translation repression activity. We demonstrate that mTORC1 phosphorylates LARP1 in vitro and in vivo, activities that are efficiently inhibited by rapamycin and torin1. We uncover 26 rapamycin-sensitive phospho-serine and -threonine residues on LARP1 that are distributed in 7 clusters. Our data show that phosphorylation of a cluster of residues located proximally to the m7Gppp cap-binding DM15 region is particularly sensitive to rapamycin and regulates both the RNA-binding and the translation inhibitory activities of LARP1. Our results unravel a new model of translation control in which the La module (LaMod) and DM15 region of LARP1, both of which can directly interact with TOP mRNA, are differentially regulated: the LaMod remains constitutively bound to PABP (irrespective of the activation status of mTORC1), while the C-terminal DM15 'pendular hook' engages the TOP mRNA 5'-end to repress translation, but only in conditions of mTORC1 inhibition.

The mTOR regulated RNA-binding protein LARP1 requires PABPC1 for guided mRNA interaction

The mammalian target of rapamycin (mTOR) is a critical regulator of cell growth, integrating multiple signalling cues and pathways. Key among the downstream activities of mTOR is the control of the protein synthesis machinery. This is achieved, in part, via the co-ordinated regulation of mRNAs that contain a terminal oligopyrimidine tract (TOP) at their 5'ends, although the mechanisms by which this occurs downstream of mTOR signalling are still unclear. We used RNA-binding protein (RBP) capture to identify changes in the protein-RNA interaction landscape following mTOR inhibition. Upon mTOR inhibition, the binding of LARP1 to a number of mRNAs, including TOP-containing mRNAs, increased. Importantly, non-TOP-containing mRNAs bound by LARP1 are in a translationally-repressed state, even under control conditions. The mRNA interactome of the LARP1-associated protein PABPC1 was found to have a high degree of overlap with that of LARP1 and our data show that PABPC1 is required for the association of LARP1 with its specific mRNA targets. Finally, we demonstrate that mRNAs, including those encoding proteins critical for cell growth and survival, are translationally repressed when bound by both LARP1 and PABPC1.

Prediction of intramuscular fat in lamb by visible and near-infrared spectroscopy in an abattoir environment

The study used visible and near-infrared spectroscopy (Vis-NIR) in a large commercial processing plant, to test a system for meat quality (intramuscular fat; IMF) data collection within a supply chain for UK lamb meat. Crossbred Texel x Scotch Mule lambs (n = 220), finished on grass on 4 farms and slaughtered across 2 months, were processed through the abattoir and cutting plant and recorded using electronic identification. Vis-NIR scanning of the cut surface of the M. longissimus lumborum produced spectral data that predicted laboratory-measured IMF% with moderate accuracy (R² 0.38-0.48). Validation of the Vis-NIR prediction equations on an independent sample of 30 lambs slaughtered later in the season, provided similar accuracy of IMF prediction (R² 0.54). Values of IMF from four different laboratory tests were highly correlated with each other (r 0.82-0.95) and with Vis-NIR predicted IMF (r 0.66-0.75). Results suggest scope to collect lamb loin IMF data from a commercial UK abattoir, to sort cuts for different customers or to feed back to breeding programmes to improve meat quality.

A coupled-enzyme equilibrium method for measuring urea in serum: optimization and evaluation of the AACC study group on urea candidate reference method

We describe a coupled-enzyme equilibrium method for measuring urea in serum, which is performed on supernates prepared by treating each specimen with Ba(OH)2 and ZnSO4 (Somogyi reagent). Analytical recovery of [14C]urea added to a variety of matrices was essentially complete (mean, 100.6%) for the supernates after precipitation. Nine variables were univariately examined in arriving at the reaction conditions for the method: glutamate dehydrogenase, urease, 2-oxoglutarate, ADP, Tris . HCI, NADH, EDTA, pH, and temperature. The reagent is stable for at least 48 days at--20 degrees C and for 23 days at 4 degrees C. Mean analytical recovery of urea (14 mmol/L) added to seven different specimens (three different matrices) was 100.8%. The analytical linear range of the method extends to 30 mmol of urea per liter. Of 22 potential interferents, only bilirubin at 1 mmol/L (580 mg/L), hemoglobin at 10 g/L, and hydroxyurea at 6 mmol/L showed more than 2% interference. We discuss precision and effects of specimen dilution, and compare results for 100 human serum specimens with those measured for the same specimens with four other urea methods. We examined the effects of measuring a blank, consisting of sample and reagent without urease, with each specimen.

Quantum Spin Ice Dynamics in the Dipole-Octupole Pyrochlore Magnet Ce_{2}Zr_{2}O_{7}

Neutron scattering measurements on the pyrochlore magnet Ce_{2}Zr_{2}O_{7} reveal an unusual crystal field splitting of its lowest J=5/2 multiplet, such that its ground-state doublet is composed of m_{J}=±3/2, giving these doublets a dipole-octupole (DO) character with local Ising anisotropy. Its magnetic susceptibility shows weak antiferromagnetic correlations with θ_{CW}=-0.4(2)  K, leading to a naive expectation of an all-in, all-out ordered state at low temperatures. Instead, our low-energy inelastic neutron scattering measurements show a dynamic quantum spin ice state, with suppressed scattering near |Q|=0, and no long-range order at low temperatures. This is consistent with recent theory predicting symmetry-enriched U(1) quantum spin liquids for such DO doublets decorating the pyrochlore lattice. Finally, we show that disorder, especially oxidation of powder samples, is important in Ce_{2}Zr_{2}O_{7} and could play an important role in the low-temperature behavior of this material.

Drosha drives the formation of DNA:RNA hybrids around DNA break sites to facilitate DNA repair

The error-free and efficient repair of DNA double-stranded breaks (DSBs) is extremely important for cell survival. RNA has been implicated in the resolution of DNA damage but the mechanism remains poorly understood. Here, we show that miRNA biogenesis enzymes, Drosha and Dicer, control the recruitment of repair factors from multiple pathways to sites of damage. Depletion of Drosha significantly reduces DNA repair by both homologous recombination (HR) and non-homologous end joining (NHEJ). Drosha is required within minutes of break induction, suggesting a central and early role for RNA processing in DNA repair. Sequencing of DNA:RNA hybrids reveals RNA invasion around DNA break sites in a Drosha-dependent manner. Removal of the RNA component of these structures results in impaired repair. These results show how RNA can be a direct and critical mediator of DNA damage repair in human cells.

Persistent HPV infection in postmenopausal age women

OBJECTIVE

Persistence of human papillomavirus (HPV) is associated with an increased risk of developing cervical SIL and cancer in young women. Because this association in older, postmenopausal age women has received little attention, we evaluated persistence of HPV among women in this age group.

METHODS

Women (n=105) ages 45-64 were examined annually for 7 years to evaluate HPV in cervical cytologic specimens. PCR, dot blot hybridization and DNA sequencing were used to detect HPV types.

RESULTS

The cumulative prevalence of HPV was 34%, and 24% had HPV high-risk oncogenic types which are associated with genital cancers. The most common oncogenic types were HPV-16 (72%) and HPV-31 (16%). The persistence rate of HPV infection was 16%. No specific risk factors were associated with repeat viral positivity.

CONCLUSION

Postmenopausal women are infected with persistent oncogenic HPV at a substantial rate, supporting the need for continued screening in postmenopausal women to detect preneoplastic genital lesions.

Pot1 OB-fold mutations unleash telomere instability to initiate tumorigenesis

Chromosomal aberrations are a hallmark of human cancers, with complex cytogenetic rearrangements leading to genetic changes permissive for cancer initiation and progression. Protection of Telomere 1 (POT1) is an essential component of the shelterin complex and functions to maintain chromosome stability by repressing the activation of aberrant DNA damage and repair responses at telomeres. Sporadic and familial mutations in the oligosaccharide-oligonucleotide (OB) folds of POT1 have been identified in many human cancers, but the mechanism underlying how hPOT1 mutations initiate tumorigenesis has remained unclear. Here we show that the human POT1’s OB-folds are essential for the protection of newly replicated telomeres. Oncogenic mutations in hPOT1 OB-fold fail to bind to ss telomeric DNA, eliciting a DNA damage response at telomeres that promote inappropriate chromosome fusions via the mutagenic alternative non-homologous end joining (A-NHEJ) pathway. hPOT1 mutations also result in telomere elongation and the formation of transplantable hematopoietic malignancies. Strikingly, conditional deletion of both mPot1a and p53 in mouse mammary epithelium resulted in development of highly invasive breast carcinomas and the formation of whole chromosomes containing massive arrays of telomeric fusions reminiscent of chromothripsis. Our results reveal that hPOT1 OB-folds are required to protect and prevent newly replicated telomeres from engaging in A-NHEJ mediated fusions that would otherwise promote genome instability to fuel tumorigenesis.

La-related Protein 1 (LARP1) Represses Terminal Oligopyrimidine (TOP) mRNA Translation Downstream of mTOR Complex 1 (mTORC1)

The mammalian target of rapamycin complex 1 (mTORC1) is a critical regulator of protein synthesis. The best studied targets of mTORC1 in translation are the eukaryotic initiation factor-binding protein 1 (4E-BP1) and ribosomal protein S6 kinase 1 (S6K1). In this study, we identify the La-related protein 1 (LARP1) as a key novel target of mTORC1 with a fundamental role in terminal oligopyrimidine (TOP) mRNA translation. Recent genome-wide studies indicate that TOP and TOP-like mRNAs compose a large portion of the mTORC1 translatome, but the mechanism by which mTORC1 controls TOP mRNA translation is incompletely understood. Here, we report that LARP1 functions as a key repressor of TOP mRNA translation downstream of mTORC1. Our data show the following: (i) LARP1 associates with mTORC1 via RAPTOR; (ii) LARP1 interacts with TOP mRNAs in an mTORC1-dependent manner; (iii) LARP1 binds the 5'TOP motif to repress TOP mRNA translation; and (iv) LARP1 competes with the eukaryotic initiation factor (eIF) 4G for TOP mRNA binding. Importantly, from a drug resistance standpoint, our data also show that reducing LARP1 protein levels by RNA interference attenuates the inhibitory effect of rapamycin, Torin1, and amino acid deprivation on TOP mRNA translation. Collectively, our findings demonstrate that LARP1 functions as an important repressor of TOP mRNA translation downstream of mTORC1.

The ever-evolving role of mTOR in translation

Control of translation allows for the production of stoichiometric levels of each protein in the cell. Attaining such a level of fine-tuned regulation of protein production requires the coordinated temporal and spatial control of numerous cellular signalling cascades impinging on the various components of the translational machinery. Foremost among these is the mTOR signalling pathway. The mTOR pathway regulates both the initiation and elongation steps of protein synthesis through the phosphorylation of numerous translation factors, while simultaneously ensuring adequate folding of nascent polypeptides through co-translational degradation of misfolded proteins. Perhaps most remarkably, mTOR is also a key regulator of the synthesis of ribosomal proteins and translation factors themselves. Two seminal studies have recently shown in translatome analysis that the mTOR pathway preferentially regulates the translation of mRNAs encoding ribosomal proteins and translation factors. Therefore, the role of the mTOR pathway in the control of protein synthesis extends far beyond immediate translational control. By controlling ribosome production (and ultimately ribosome availability), mTOR is a master long-term controller of protein synthesis. Herein, we review the literature spanning the early discoveries of mTOR on translation to the latest advances in our understanding of how the mTOR pathway controls the synthesis of ribosomal proteins.

Serotonin (5-HT) receptor 5A sequence variants affect human plasma triglyceride levels

Neurotransmitters such as serotonin (5-hydroxytryptamine, 5-HT) work closely with leptin and insulin to fine-tune the metabolic and neuroendocrine responses to dietary intake. Losing the sensitivity to excess food intake can lead to obesity, diabetes, and a multitude of behavioral disorders. It is largely unclear how different serotonin receptor subtypes respond to and integrate metabolic signals and which genetic variations in these receptor genes lead to individual differences in susceptibility to metabolic disorders. In an obese cohort of families of Northern European descent (n = 2,209), the serotonin type 5A receptor gene, HTR5A, was identified as a prominent factor affecting plasma levels of triglycerides (TG), supported by our data from both genome-wide linkage and targeted association analyses using 28 publicly available and 12 newly discovered single nucleotide polymorphisms (SNPs), of which 3 were strongly associated with plasma TG levels (P < 0.00125). Bayesian quantitative trait nucleotide (BQTN) analysis identified a putative causal promoter SNP (rs3734967) with substantial posterior probability (P = 0.59). Functional analysis of rs3734967 by electrophoretic mobility shift assay (EMSA) showed distinct binding patterns of the two alleles of this SNP with nuclear proteins from glioma cell lines. In conclusion, sequence variants in HTR5A are strongly associated with high plasma levels of TG in a Northern European population, suggesting a novel role of the serotonin receptor system in humans. This suggests a potential brain-specific regulation of plasma TG levels, possibly by alteration of the expression of HTR5A.

INSIG1 influences obesity-related hypertriglyceridemia in humans

In our analysis of a quantitative trait locus (QTL) for plasma triglyceride (TG) levels [logarithm of odds (LOD) = 3.7] on human chromosome 7q36, we examined 29 single nucleotide polymorphisms (SNPs) across INSIG1, a biological candidate gene in the region. Insulin-induced genes (INSIGs) are feedback mediators of cholesterol and fatty acid synthesis in animals, but their role in human lipid regulation is unclear. In our cohort, the INSIG1 promoter SNP rs2721 was associated with TG levels (P = 2 x 10(-3) in 1,560 individuals of the original linkage cohort, P = 8 x 10(-4) in 920 unrelated individuals of the replication cohort, combined P = 9.9 x 10(-6)). Individuals homozygous for the T allele had 9% higher TG levels and 2-fold lower expression of INSIG1 in surgical liver biopsy samples when compared with individuals homozygous for the G allele. Also, the T allele showed additional binding of nuclear proteins from HepG2 liver cells in gel shift assays. Finally, the variant rs7566605 in INSIG2, the only homolog of INSIG1, enhances the effect of rs2721 (P = 0.00117). The variant rs2721 alone explains 5.4% of the observed linkage in our cohort, suggesting that additional, yet-undiscovered genes and sequence variants in the QTL interval also contribute to alterations in TG levels in humans.

cdc2-cyclin B regulates eEF2 kinase activity in a cell cycle- and amino acid-dependent manner

The calcium/calmodulin-dependent kinase that phosphorylates and inactivates eukaryotic elongation factor 2 (eEF2 kinase; eEF2K) is subject to multisite phosphorylation, which regulates its activity. Phosphorylation at Ser359 inhibits eEF2K activity even at high calcium concentrations. To identify the kinase that phosphorylates Ser359 in eEF2K, we developed an extensive purification protocol. Tryptic mass fingerprint analysis identified it as cdc2 (cyclin-dependent kinase 1). cdc2 co-purifies with Ser359 kinase activity and cdc2-cyclin B complexes phosphorylate eEF2K at Ser359. We demonstrate that cdc2 contributes to controlling eEF2 phosphorylation in cells. cdc2 is activated early in mitosis. Kinase activity against Ser359 in eEF2K also peaks at this stage of the cell cycle and eEF2 phosphorylation is low in mitotic cells. Inactivation of eEF2K by cdc2 may serve to keep eEF2 active during mitosis (where calcium levels rise) and thereby permit protein synthesis to proceed in mitotic cells. Amino-acid starvation decreases cdc2's activity against eEF2K, whereas loss of TSC2 (a negative regulator of mammalian target of rapamycin complex 1(mTORC1)) increases it. These data closely match the control of Ser359 phosphorylation and indicate that cdc2 may be regulated by mTORC1.

PRAS40 is a target for mammalian target of rapamycin complex 1 and is required for signaling downstream of this complex

Signaling through the mammalian target of rapamycin complex 1 (mTORC1) is positively regulated by amino acids and insulin. PRAS40 associates with mTORC1 (which contains raptor) but not mTORC2. PRAS40 interacts with raptor, and this requires an intact TOR-signaling (TOS) motif in PRAS40. Like TOS motif-containing proteins such as eIF4E-binding protein 1 (4E-BP1), PRAS40 is a substrate for phosphorylation by mTORC1. Consistent with this, starvation of cells of amino acids or treatment with rapamycin alters the phosphorylation of PRAS40. PRAS40 binds 14-3-3 proteins, and this requires both amino acids and insulin. Binding of PRAS40 to 14-3-3 proteins is inhibited by TSC1/2 (negative regulators of mTORC1) and stimulated by Rheb in a rapamycin-sensitive manner. This confirms that PRAS40 is a target for regulation by mTORC1. Small interfering RNA-mediated knockdown of PRAS40 impairs both the amino acid- and insulin-stimulated phosphorylation of 4E-BP1 and the phosphorylation of S6. However, this has no effect on the phosphorylation of Akt or TSC2 (an Akt substrate). These data place PRAS40 downstream of mTORC1 but upstream of its effectors, such as S6K1 and 4E-BP1.

Human Experience Modeler: context-driven cognitive retraining to facilitate transfer of learning

We describe a cognitive rehabilitation mixed-reality system that allows therapists to explore natural cuing, contextualization, and theoretical aspects of cognitive retraining, including transfer of training. The Human Experience Modeler (HEM) mixed-reality environment allows for a contextualized learning experience with the advantages of controlled stimuli, experience capture and feedback that would not be feasible in a traditional rehabilitation setting. A pilot study for testing the integrated components of the HEM is discussed where the participant presents with working memory impairments due to an aneurysm.

Multilocus sequence typing of intercontinental bovine Staphylococcus aureus isolates

A total of 258 bovine-associated Staphylococcus aureus isolates from the United States, Chile, and the United Kingdom, plus the reference isolate S. aureus Newbould 305 (NCIMB 702892), were analyzed by multilocus sequence typing (MLST). A collection of previously characterized United Kingdom isolates were also included in the analysis. The results demonstrated that MLST is suitable for the differentiation of bovine S. aureus isolates from various sites (milk, teat skin, milking machine unit liners, hands, and bedding) and countries. The theory of the host specificity of S. aureus is supported by the detection of a previously undescribed clonal complex that comprised 87.4% of the isolates studied, with representatives from all geographic locations investigated. This suggests that a single clonal group has achieved a widespread distribution and is responsible for the majority of infections. Some sequence types (STs; ST25, ST115, ST124, and ST126) demonstrated site specificity, as they were significantly (P < 0.05) associated with milk or teat skin.

Multilocus sequence typing of Staphylococcus aureus isolated from high-somatic-cell-count cows and the environment of an organic dairy farm in the United Kingdom

An outbreak of Staphylococcus aureus intramammary infections on an organic dairy farm was monitored for 10 months. Environmental and milk samples were collected from a total of 26 cows and a group of 21 purchased heifers about to be introduced into the milking herd. There was variation in the rate of isolation of S. aureus (9.5 to 43.8%) from individual mammary quarters, although no S. aureus isolates were detected in the milk samples collected from the heifers. One hundred ninety-one S. aureus isolates were detected from cow milk samples (n = 182), milking machine clusters (n = 4), farm personnel (n = 4), and the environment (n = 1). Multilocus sequence typing (MLST) had a typeability of 100% when it was applied to the 191 isolates. Among the 191 isolates there was limited strain diversity, with seven sequence types (STs) dominated by two strains with closely related STs that differed at a single locus. Within individual mammary quarters there were naturally occurring dual infections, although this was identified in only 0.4% of milk samples. Different strains were associated with variable persistence within quarters. MLST is clearly a very suitable tool for the differentiation and analysis of S. aureus populations detected on dairy cattle farms.

HPV prevalence and concordance in the cervix and oral cavity of pregnant women

OBJECTIVES

This investigation examined human papillomavirus (HPV) in pregnant women in order to characterize viral prevalence, types and concordance between infection in the cervix and in the oral cavity.

METHODS

A total of 577 pregnant women seeking routine obstetric care were evaluated for HPV infection in their cervix during gestation and immediately before delivery, and in the oral cavity during gestation. Male partners present during the gestational clinic visit also provided a specimen from their oral cavity. HPV assessment was performed by PCR, dot blot hybridization and DNA sequencing. A sexual and health questionnaire was completed by the pregnant women.

RESULTS

HPV prevalence in women was 29% in the cervix and 2.4% in the oral cavity. Among those with both gestational and delivery specimens, 35% were infected at least once and 20% had infection at both intervals. At delivery, 68% of infected women had an oncogenic HPV type in the cervix. There was no type-specific HPV concordance between the two cervical specimens, nor cervical and oral results in women, nor with cervical and oral findings between partners.

CONCLUSION

The lack of association in HPV positivity and types between the cervix and oral cavity in these women suggests that self-inoculation is uncommon. This source of infection does not appear to be from oral contact with a current male partner, since there also was no concordance between partners. These results suggest either other modes of HPV transmission or differences in susceptibility to HPV infection or its clearance in the oral cavity and genital mucosa.

The tuberous sclerosis protein TSC2 is not required for the regulation of the mammalian target of rapamycin by amino acids and certain cellular stresses

Amino acids positively regulate signaling through the mammalian target of rapamycin (mTOR). Recent work demonstrated the importance of the tuberous sclerosis protein TSC2 for regulation of mTOR by insulin. TSC2 contains a GTPase-activator domain that promotes hydrolysis of GTP bound to Rheb, which positively regulates mTOR signaling. Some studies have suggested that TSC2 also mediates the control of mTOR by amino acids. In cells lacking TSC2, amino acid withdrawal still results in dephosphorylation of S6K1, ribosomal protein S6, the eukaryotic initiation factor 4E-binding protein, and elongation factor-2 kinase. The effects of amino acid withdrawal are diminished by inhibiting protein synthesis or adding back amino acids. These studies demonstrate that amino acid signaling to mTOR occurs independently of TSC2 and involves additional unidentified inputs. Although TSC2 is not required for amino acid control of mTOR, amino acid withdrawal does decrease the proportion of Rheb in the active GTP-bound state. Here we also show that Rheb and mTOR form stable complexes, which are not, however, disrupted by amino acid withdrawal. Mutants of Rheb that cannot bind GTP or GDP can interact with mTOR complexes. We also show that the effects of hydrogen peroxide and sorbitol, cell stresses that impair mTOR signaling, are independent of TSC2. Finally, we show that the ability of energy depletion (which impairs mTOR signaling in TSC2+/+ cells) to increase the phosphorylation of eukaryotic elongation factor 2 is also independent of TSC2. This likely involves the phosphorylation of the elongation factor-2 kinase by the AMP-activated protein kinase.

Assessing the independent contribution to quality of life from anxiety and depression in patients with advanced cancer

BACKGROUND

The aim of palliative care services is to ensure the best quality of life for patients and their carers. Depression is common amongst palliative care patients and has been shown to adversely affect quality of life. This study aimed to examine the independent contribution of depression to quality of life.

OBJECTIVE

To investigate the hypothesis that a) illness severity, pain, anxiety and depression are all associated with impaired health-related quality of life and b) once the effects of illness severity have been adjusted for, there is further independent contribution to quality of life from anxiety and depression.

METHOD

Consecutive patients with advanced cancer under the care of palliative care services were screened. Sixty-eight patients were evaluated for levels of anxiety and depression, severity of illness, pain severity and health-related quality of life.

RESULTS

Thirty-three males and 35 females were recruited and had an age range of 41-93 years (median 71). Seventeen (25%) of patients were anxious [anxiety score > or = 11 on the Hospital Anxiety and Depression Scale (HADS)], 15 (22%) were depressed (HADS depression score > or = 11). After controlling for the effects of pain and illness severity, anxiety and depression were independently associated with global health status, emotional and cognitive functioning, and fatigue. Anxiety further contributed significantly towards social functioning, nausea and vomiting.

CONCLUSIONS

This study has confirmed that pain, anxiety and depression were associated with impaired quality of life. Anxiety and depression contributed independently towards various dimensions of quality of life. Longitudinal studies are required to examine the direction of the causal association between pain and depression in patients receiving palliative care.

The current and future management of malignant ascites

Malignant ascites occurs in association with a variety of neoplasms. It is a frequent cause of morbidity and presents significant problems for which there are no clear management guidelines. In this article we discuss various modalities which are available including diuretic therapy, paracentesis, peritoneovenous shunts and intraperitoneal chemotherapy. There are no randomized trials of diuretic drugs to assess their efficacy in malignant ascites. Phase II data suggest that they are effective in approximately one-third of patients with malignancy, and their efficacy may be determined by plasma renin/aldosterone concentrations. Paracentesis provides relief in up to 90% of patients; because of varying reports of hypovolaemia, some advocate simultaneous intravenous fluid infusion. Permanent percutaneous drains may prevent the need for repeated paracentesis, although there is potential for infection. A peritoneovenous shunt also prevents the need for repeated paracenteses, whilst maintaining normal serum albumin concentrations. Blockage occurs in 25% of shunts, which are contraindicated in the presence of heavily bloodstained ascites because of the risk of occlusion. The preclinical and clinical experience with anti-angiogenic agents such as the matrix metalloproteinase inhibitors and the VEGF antagonists suggests that these agents may have a role in the treatment of malignant ascites.

Is use of hormone replacement therapy associated with increased detection of human papillomavirus and potential risk of HPV-related genital cancers?

Oral contraceptives (OC) are a risk factor for female genital cancers and in vivo studies have shown that progestins stimulate human papillomavirus (HPV) gene expression. A similar role for hormone replacement therapy (HRT) has received little evaluation. Cervical/vaginal specimens were obtained to detect HPV from postmenopausal women (n = 429) seeking annual gynaecologic care. HPV was detected in 14% of women and 4.4% had high-risk, oncogenic types. HPV prevalence was similar across current, past and never HRT users. After adjustment for HPV-related risk factors, current and past user status showed no increased viral detection compared with never users. HRT duration also did not elevate risk among current users. However, longer duration (adj. OR 1.5/year, 95% CI 1.0-2.3) and longer latency (adj. OR 1.2/year, 95% CI 0.9-1.7) among past users of oestrogen/progestin regimens were associated with greater risk. Overall use of HRTs was not associated with HPV detection or disease. However, past users of combination HRTs had significantly greater risk of HPV detection with longer HRT duration and latency, similar to OC-HPV findings. The recommendation that postmenopausal women continue HRTs long term may lead to an increased development of HPV-related diseases, of particular concern among those who discontinue HRTs and subsequent gynaecologic care for early cancer detection.

Beta (CC)-chemokines as modulators of sleep: implications for HIV-induced alterations in arousal state

Sleep is altered early in the course of HIV infection, before the onset of AIDS, indicating effects of the virus on neural processes. Previous observations suggest HIV envelope glycoproteins are possible mediators of these responses. Because some beta (CC)-chemokine receptors serve as co-receptors for HIV and bind HIV envelope glycoproteins, we determined in this study whether selected CC chemokine ligands alter sleep and whether their mRNAs are detectable in brain regions important for sleep. CCL4/MIP-1beta, but not CCL5/RANTES, injected centrally into rats prior to dark onset increased non-rapid eye movements sleep, fragmented sleep, and induced fever. mRNA for the chemokine receptor CCR3 was detectable under basal conditions in multiple brain regions. These data suggest some CC chemokines may also be involved in processes by which HIV alters sleep.

A prospective study of coping after exposure to a mass murder episode

In a study of 136 survivors of a mass murder spree, multidimensional scaling identified clusters of responses mapping from 75 coping behaviors described by victims. This powerful method identified three coping dimensions: (a) Active Outreach versus Passive Isolation, (b) Informed Pragmatism versus Abandonment of Control, and (c) Reconciliation/Acceptance versus Evading the Status Quo. These coping dimensions were used to predict change in psychiatric status prospectively assessed with structured diagnostic interviews at index 3-4 months after the event and follow-up assessments 1 and 3 years later. Statistically significant changes in the positive direction on each of the three dimensions in this study were associated with reductions of 47-79% of the odds for acute postdisaster major depression, posttraumatic stress disorder (PTSD), and any non-PTSD disorder. These findings suggest mechanisms for development of therapeutic techniques capitalizing on encouraging active outreach, informed focus and pragmatism, and reconciliation and acceptance, and reduction of passive and isolative behaviors, resignation of control, and avoidance of realities of the postdisaster situation.

Planning for a multi-imaging center picture archiving and communications system

There are fundamental differences in planning and configuring a picture archiving and communications system (PACS) for a multisite imaging practice as compared to a hospital-based radiology department. In the for-profit, multi-imaging center environment, return on investment is more critical and the distributed nature of radiology operations presents complex communications, infrastructure, archiving, workflow, and distribution requirements. This article discusses desired outcomes for a multi-imaging center PACS and the planning, functional, technical, and support requirements necessary to achieve those outcomes.

ACTH receptor distribution and modulation among murine mononuclear leukocyte populations

Murine mononuclear leukocytes express adrenocorticotropin (ACTH) receptors that were recognized by a monospecific antiserum to the ACTH receptor on Y-1 adrenal cells. The antiserum was utilized in an immunofluorescence (IF) assay to characterize the distribution of ACTH receptors on resting murine mononuclear leukocyte populations. Forty-seven percent of spleen cells, 32% of lymph node cells, and 1% of thymocytes constitutively expressed ACTH receptors. Separation of lymphocytes into purified B cell and T cell populations, followed by IF analysis revealed that 47% of B cells and 23% of T cells possessed ACTH receptors. Helper T cells (CD4+ T cells) constituted the majority of ACTH receptor-positive T lymphocytes. Furthermore, 47% of resident peritoneal macrophages, purified by adherence to plastic, expressed ACTH receptors. The T-lymphocyte mitogen, concanavalin A, interferon gamma, and ACTH enhanced ACTH receptor expression. The differential distribution of ACTH receptor-positive cells among specific leukocyte populations explains in part why differential cellular responses are observed and implies important regulatory functions for these receptors in the generation or regulation of immune responses.

Inhibition of angiogenesis and tumor growth by SCH221153, a dual alpha(v)beta3 and alpha(v)beta5 integrin receptor antagonist

New blood vessel formation is essential for tumor growth and metastatic spread. Integrins alpha(v)beta3 and alpha(v)beta5 are arginine-glycine-aspartic acid-dependent adhesion receptors that play a critical role in angiogenesis. Hence, selective dual alpha(v)beta3 and alpha(v)beta5 antagonists may represent a novel class of angiogenesis and tumor-growth inhibitors. Here, an arginine-glycine-aspartic acid-based peptidomimetic library was screened to identify alpha(v)beta3 antagonists. Selected compounds were then modified to generate potent and selective dual inhibitors of alpha(v)beta3 and alpha(v)beta5 receptors. One of these compounds, SCH 221153, inhibited the binding of echistatin to alpha(v)beta3 (IC50 = 3.2 nM) and alpha(v)beta5 (IC50 = 1.7 nM) with similar potency. Its IC50 values for related alpha(IIb)beta3 and alpha5beta1 receptors were 1294 nM and 421 nM, respectively, indicating that SCH 221153 is highly selective for alpha(v)beta3 and alpha(v)beta5 receptors. In cell-based assays, SCH 221153 inhibited the binding of echistatin to alpha(v)beta3- and alpha(v)beta5-expressing 293 cells and blocked the adhesion of endothelial cells to immobilized vitronectin and fibroblast growth factor 2 (FGF2). SCH 221153, but not the inactive analogue SCH 216687, was effective in inhibiting FGF2 and vascular endothelial growth factor-induced endothelial cell proliferation in vitro with an IC50 equal to 3-10 microM. Angiogenesis induced by FGF2 in the chick chorioallantoic membrane assay was also inhibited by SCH 221153. Finally, SCH 221153 exerted a significant inhibition on tumor growth induced by intradermal or s.c. injection of human melanoma LOX cells in severe combined immunodeficient mice.

DNA separations in microfabricated devices with automated capillary sample introduction

A novel method is presented for automated injection of DNA samples into microfabricated separation devices via capillary electrophoresis. A single capillary is used to electrokinetically inject discrete plugs of DNA into an array of separation lanes on a glass chip. A computer-controlled micromanipulator is used to automate this injection process and to repeat injections into five parallel lanes several times over the course of the experiment. After separation, labeled DNA samples are detected by laser-induced fluorescence. Five serial separations of 6-carboxyfluorescein (FAM)-labeled oligonucleotides in five parallel lanes are shown, resulting in the analysis of 25 samples in 25 min. It is estimated that approximately 550 separations of these same oligonucleotides could be performed in one hour by increasing the number of lanes to 37 and optimizing the rate of the manipulator movement. Capillary sample introduction into chips allows parallel separations to be continuously performed in serial, yielding high throughput and minimal need for operator intervention.

Human papillomavirus in the oral cavities of children and adolescents

OBJECTIVE

The purpose of this pilot study was to determine the frequency of human papillomavirus (HPV) in the oral cavities of children and adolescents and to identify potential risk factors for HPV infection.

STUDY DESIGN

Sociodemographic information was obtained on 268 healthy infants, children, and adolescents who were < or = 20 years old. Oral squamous cells were collected from swabs with young children and from oral saline solution rinses with older children and adolescents. Extracted DNA was evaluated for HPV by polymerase chain reaction, dot blot hybridization, and DNA sequencing. Factors associated with the presence of HPV were tested by using chi(2), Fisher's exact test, and logistic regression tests.

RESULTS

HPV was detected in 6.0% of the participants. HPV frequency among young children (<7 years old) was 8.7% (11/127), and among adolescents (13-20 years old) it was 5.2% (5/97). HPV was not detected in children aged 7 to 12 years old (0/44). Fifty-four percent (6/11) of HPV-positive children were 1 year of age or less; 3 of the HPV-positive children (<7 years old) were delivered by cesarean section. No statistically significant association was found between the detection of HPV in the oral cavity and method of delivery or gender; parent's race, education, HPV-related conditions, smoking history, or number of sex partners; or adolescent's smoking history or history of sexual activity.

CONCLUSIONS

This study suggests that HPV is present in the oral cavity primarily in children 2 years old and younger and in adolescents 13 years and older. Cesarean delivery was not protective against oral HPV infection; in fact, half of the HPV-positive infants were born by cesarean delivery.

Human papillomavirus and risk of laryngeal cancer

We determined the relationship between human papillomavirus (HPV) infection and the HPV types detected in 44 patients with squamous cell carcinoma, 10 laryngeal leukoplakia patients, and 12 patients evaluated for benign laryngeal conditions (controls). The sources of HPV DNA were from brushings from the upper respiratory tract and lesion (benign or malignant), oral rinses, and biopsies of patient lesions. Polymerase chain reaction (PCR) and DNA sequencing were used to identify and type HPV. We detected HPV in 25.0% (11/44) of patients with laryngeal cancer, in 30.0% (3/10) of patients with laryngeal leukoplakia, and in 16.7% (2/12) of noncancer controls. Patients with cancer were not more likely to be identified with oncogenic HPV types ( 18.2%) than either the leukoplakia group (20%) or the control group (16.7%). An increased risk of disease was associated with current tobacco use and former alcohol drinking in cancer patients versus controls and in leukoplakia patients versus controls (all p < .05). After we controlled for tobacco and alcohol effects on the risk of disease, exposure to oncogenic HPV types was associated with an increased risk of laryngeal cancer (odds ratio = 3.0) and of laryngeal leukoplakia (odds ratio = 6.0) compared to controls, although the results were not statistically significant. This study suggests that although HPV infection and HPV oncogenic types are not found at a higher frequency in laryngeal cancer or laryngeal leukoplakia as compared to controls, infection is associated with an increased risk of disease after controlling for the effects of alcohol and tobacco use.

p53 polymorphism, human papillomavirus infection in the oral cavity, and oral cancer

OBJECTIVES

Human papillomavirus (HPV) infection has emerged as a risk factor in oral carcinogenesis. An arginine-coding polymorphism of the tumor suppressor protein p53 at codon 72 is more readily degraded by the HPV oncoprotein E6. Our objective was to evaluate the association between p53 polymorphism at codon 72 and HPV infection in the oral cavity, as well as its association with oral cancer.

STUDY DESIGN

Oral squamous cells from 202 patients with oral cancer and 333 age-sex frequency matched controls were evaluated by polymerase chain reaction for the presence and type of HPV and for alleles of codon 72 in p53. Fisher exact test and chi(2) tests were used to evaluate the data.

RESULTS

The p53 codon 72 polymorphism is not associated with HPV infection, whether comparing HPV-negative controls with HPV-positive controls or comparing HPV-negative cases with HPV-positive cases. Additionally, we found no association with the codon 72 polymorphism and oral cancer, whether comparing HPV-negative controls with HPV-negative cases or comparing HPV-positive controls with HPV-positive cases.

CONCLUSIONS

There is no association between p53 codon 72 polymorphism and HPV infection or between the p53 polymorphism and the risk of oral cancer.

Human immunodeficiency virus glycoprotein 160 induces cytokine mRNA expression in the rat central nervous system

1. Elevated proinflammatory cytokines within the central nervous system (CNS) of individuals infected with human immunodeficiency virus (HIV) may contribute to altered CNS processes prior to the onset of AIDS. Most studies of HIV-induced alterations in cytokine expression within the CNS have focused on interleukin (IL)-1 and tumor necrosis factor (TNF). 2. We used a ribonuclease protection assay (RPA) to elucidate further the pattern of cytokine mRNA expression in the rat CNS in response to HIV envelope glycoprotein 160 (gp160). Male Sprague-Dawley rats were surgically implanted with a guide cannula directed into a lateral cerebral ventricle. HIV gp160 was injected intracerebroventricularly and rats were sacrificed immediately (time = 0) or at 1, 2, or 4 hr postinjection. Discrete brain regions were dissected, and peripheral glands removed. All tissues were frozen in liquid nitrogen until RNA extraction and assay. 3. IL-1beta IL-1alpha, TNF-alpha, and TNFbeta mRNAs were constitutively expressed in brain tissues. Central administration of gp160 dramatically increased mRNA expression for IL-1beta and TNFalpha in the hypothalamus, hippocampus, brainstem, and cerebellum. Furthermore, although mRNA expression for IL-5, IL-6, and IL-10 was never detected under basal conditions, these mRNAs were increased in brain tissue after administration of gp160. Peak expression in each brain region was detected 2 hr after administration. Multiple cytokine mRNAs were detected in peripheral tissues, but their expression was not altered by central administration of gp160. 4. Our results indicate that gp160 induces mRNA expression in brain for cytokines other than IL-1 and TNF. Screening for multiple cytokine mRNA in this manner provides extensive information concerning the particular cytokines that may be involved in HIV-induced pathologies and alterations in CNS processes.

Risk factors for radial artery harvest site infection following coronary artery bypass graft surgery

Radial arteries increasingly are used during coronary artery bypass graft (CABG) surgery. Although risk factors for saphenous vein harvest site infection (HSI) have been reported, rates of and risk factors for radial artery HSI are not well established. We compared rates of radial artery HSI that were detected by 2 surveillance methods, regular and heightened. Risk factors were determined by a case-control study. We identified 35 radial artery HSIs ("case sites") in 26 case patients. The radial artery HSI rate was significantly higher during heightened surveillance than during routine surveillance (12.3% vs. 3.1%, respectively; P=.002). Multivariate analysis showed that diabetes mellitus with a preoperative glucose level >/=200 mg/dL (odds ratio [OR], 4.4; P=. 01) and duration of surgery >/=5 h (OR, 3.1; P=.02) were independent risk factors for radial artery HSI. Infection is a common complication of radial artery harvesting for CABG surgery, and infection rates are dependent on the intensity of surveillance. We identified preoperative hyperglycemia and surgery duration as independent risk factors for radial artery HSI.

What parts of PTSD are normal: intrusion, avoidance, or arousal? Data from the Northridge, California, earthquake

The incidence and comorbidity of posttraumatic stress disorder (PTSD) are addressed in a study of 130 Northridge, California, earthquake survivors interviewed 3 months post-disaster. Only 13% of the sample met full PTSD criteria, but 48% met both the re-experiencing and the arousal symptom criteria, without meeting the avoidance and numbing symptom criterion. Psychiatric comorbidity was associated mostly with avoidance and numbing symptoms. For moderately severe traumatic events, re-experiencing and arousal symptoms may be the most "normal," and survivors with a history of psychiatric problems may be those most likely to develop full PTSD. A system that considers people who meet all three symptom criteria to have a psychiatric disorder yet recognizes the distress of other symptomatic survivors may best serve traumatized populations.

Modifiable risk factors associated with deep sternal site infection after coronary artery bypass grafting

OBJECTIVE

Our objective was to identify risk factors for deep sternal site infection after coronary artery bypass grafting at a community hospital.

METHODS

We compared the prevalence of deep sternal site infection among patients having coronary artery bypass grafting during the study (January 1995-March 1998) and pre-study (January 1992-December 1994) periods. We compared any patient having a deep sternal site infection after coronary artery bypass graft surgery during the study period (case-patients) with randomly selected patients who had coronary artery bypass graft surgery but no deep sternal site infection during the same period (control-patients).

RESULTS

Deep sternal site infections were significantly more common during the study than during the pre-study period (30/1796 [1.7%] vs 9/1232 [0.7%]; P =.04). Among 30 case-patients, 29 (97%) returned to the operating room for sternal debridement or rewiring, and 2 (7%) died. In multivariable analyses, cefuroxime receipt 2 hours or more before incision (odds ratio = 5.0), diabetes mellitus with a preoperative blood glucose level of 200 mg/dL or more (odds ratio = 10.2), and staple use for skin closure (odds ratio = 4.0) were independent risk factors for deep sternal site infection. Staple use was a risk factor only for patients with a normal body mass index.

CONCLUSIONS

Appropriate timing of antimicrobial prophylaxis, control of preoperative blood glucose levels, and avoidance of staple use in patients with a normal body mass index should prevent deep sternal site infection after coronary artery bypass graft operations.

IL-10 as a mediator in the HPA axis and brain

Certain functional interactions between the nervous, endocrine, and immune systems are mediated by cytokines. The pro-inflammatory cytokines, interleukin-1 (IL-1) and tumor necrosis factor (TNF) were among the first to be recognized in this regard. A modulator of these cytokines, IL-10, has been shown to have a wide range of activities in the immune system; in this review, we describe its production and actions in the hypothalamic-pituitary-adrenal (HPA) axis. IL-10 is produced in pituitary, hypothalamic, and neural tissues in addition to lymphocytes. IL-10 enhances corticotropin releasing factor (CRF) and corticotropin (ACTH) production in hypothalamic and pituitary tissues, respectively. Further downstream in the HPA axis endogenous IL-10 has the potential to contribute to regulation of glucocorticosteroid production both tonically and following stressors. Our studies and those of others reviewed here indicate that IL-10 may be an important endogenous regulator in HPA axis activity and in CNS pathologies such as multiple sclerosis. Thus, in addition to its more widely recognized role in immunity, IL-10's neuroendocrine activities described here point to its role as an important regulator in communication between the immune and neuroendocrine systems.

Observation of long-range small-molecule NOEs using a neoteric sensitivity enhancement scheme

A new method to increase the sensitivity of the 1D transient NOE experiment for molecules in the positive NOE regime is presented. This method, the reverse NOE, simply replaces the conventional relaxation delay between scans. Transient positive NOE enhancements from all other spins are used to accelerate the recovery of the target resonance toward its equilibrium intensity. In favorable cases, the intensity of the target peak at the start of an experiment can actually be increased beyond its equilibrium value. There is also a sensitivity enhancement in the rapid pulsing regime, where recovery is always incomplete. This sensitivity enhancement is illustrated with the one-dimensional double pulsed field gradient spin echo NOE experiment to observe a "fourth-order" NOE. Sensitivity gains of 30% are demonstrated.

Psychiatric disorders among survivors of the Oklahoma City bombing

CONTEXT

Disasters expose unselected populations to traumatic events and can be used to study the mental health effects. The Oklahoma City, Okla, bombing is particularly significant for the study of mental health sequelae of trauma because its extreme magnitude and scope have been predicted to render profound psychiatric effects on survivors.

OBJECTIVE

To measure the psychiatric impact of the bombing of the Alfred P. Murrah Federal Building in Oklahoma City on survivors of the direct blast, specifically examining rates of posttraumatic stress disorder (PTSD), diagnostic comorbidity, functional impairment, and predictors of postdisaster psychopathology.

DESIGN, SETTING, AND PARTICIPANTS

Of 255 eligible adult survivors selected from a confidential registry, 182 (71%) were assessed systematically by interviews approximately 6 months after the disaster, between August and December 1995.

MAIN OUTCOME MEASURES

Diagnosis of 8 psychiatric disorders, demographic data, level of functioning, treatment, exposure to the event, involvement of family and friends, and physical injuries, as ascertained by the Diagnostic Interview Schedule/Disaster Supplement.

RESULTS

Forty-five percent of the subjects had a postdisaster psychiatric disorder and 34.3% had PTSD. Predictors included disaster exposure, female sex (for any postdisaster diagnosis, 55% vs 34% for men; chi2 = 8.27; P=.004), and predisaster psychiatric disorder (for PTSD, 45% vs 26% for those without predisaster disorder; chi2 = 6.86; P=.009). Onset of PTSD was swift, with 76% reporting same-day onset. The relatively uncommon avoidance and numbing symptoms virtually dictated the diagnosis of PTSD (94% meeting avoidance and numbing criteria had full PTSD diagnosis) and were further associated with psychiatric comorbidity, functional impairment, and treatment received. Intrusive reexperience and hyperarousal symptoms were nearly universal, but by themselves were generally unassociated with other psychopathology or impairment in functioning.

CONCLUSIONS

Our data suggest that a focus on avoidance and numbing symptoms could have provided an effective screening procedure for PTSD and could have identified most psychiatric cases early in the acute postdisaster period. Psychiatric comorbidity further identified those with functional disability and treatment need. The nearly universal yet distressing intrusive reexperience and hyperarousal symptoms in the majority of nonpsychiatrically ill persons may be addressed by nonmedical interventions of reassurance and support.

Technique for correction of the retracted columella, acute columellar-labial angle, and long upper lip

The excess tissue from upper lip vertical length reduction provides bulk for opening the columella-labial angle and increasing the visibility of the columella and upper lip vermillion. Decorticated centrally based transverse flaps from the lip and nostril floor, when transposed into a columellar pocket, correct commonly combined degenerative or developmental deformities. The technique delivers premaxilla, columella, and columella-labial angle mass, which simultaneously corrects the retracted columella, opens the columella-labial angle, shortens the upper lip length, and enhances vermillion visibility.