Skeletal muscle mass is an imaging biomarker for decreased survival in patients with oropharyngeal squamous cell carcinoma.

OBJECTIVES: Low skeletal muscle mass (SMM) and sarcopenic obesity (co-presence of low SMM and obesity) are emerging prognosticators in oncology, but the prevalence and prognostic value in oropharyngeal squamous cell carcinoma (OPSCC) is not yet known. MATERIALS AND METHODS: Patients with OPSCC, curative treatment intention and pre-treatment diagnostic imaging of the head and neck area were included. Patients with unknown HPV-status, palliative treatment intention or unavailable imaging were excluded, Relevant demographic and clinical characteristics were collected between 2009 and 2016. Patients were stratified into a low-, intermediate-, and high-risk group according to HPV-status, amount of pack-years, tumor and nodal stage. SMM was radiologically measured and cutoff values were determined by optimal stratification. The prognostic value of low SMM and sarcopenic obesity for overall survival (OS) and disease-free survival (DFS) was determined by Cox regression analysis and Kaplan Meier survival curves. RESULTS: In 216 patients, low SMM and sarcopenic obesity were present in 140 (64.8%) and 13 (6.0%) patients, respectively. On multivariate analysis, stratification into a high-risk group (HPV-negative status with ≥10-pack-years or T4-stage) was a prognostic factor for OS and DFS (HR 2.93, p < 0.01) (HR 4.66, p < 0.01). Of specific interest, sarcopenic obesity was a strong negative prognostic factor for OS and DFS (HR 4.42, p < 0.01 and (HR 3.90, p < 0.05), independent from other well-known prognostic factors such as HPV-status. CONCLUSION: Low skeletal muscle mass is highly prevalent in OPSCC patients. Sarcopenic obesity is a novel pretreatment prognosticator for OS and DFS in OPSCC and should therefore be considered in clinical decision making.

Interobserver agreement of skeletal muscle mass measurement on head and neck CT imaging at the level of the third cervical vertebra.

OBJECTIVES: Skeletal muscle mass (SMM) is most often assessed in cancer patients on abdominal computed tomography (CT) imaging at the level of the third lumbar vertebra (L3). Abdominal CT imaging is not routinely performed in head and neck cancer (HNC) patients. Recently, a novel method to assess SMM on a single transversal CT slice at the level of the third cervical vertebra (C3) was published. The objective of this study was to assess the robustness of this novel C3 measurement method in terms of interobserver agreement. PATIENTS AND METHODS: Patients diagnosed with locally advanced head and neck squamous cell carcinoma (LA-HNSCC) at our center between 2007 and 2011 were evaluated. Fifty-four patients with were randomly selected for analysis. Six observers independently measured the cross-sectional muscle area (CSMA) at the level of C3 using a predefined, written protocol as instruction. Interobserver agreement was assessed using intraclass correlation coefficients (ICCs), a Bland-Altman plot and Fleiss' kappa (κ). RESULTS: The agreement in vertebra selection between all observers was excellent (Fleiss' κ: 0.96). There was a substantial agreement between all observers in single slice selection (Fleiss' κ: 0.61). For all CSMA measurements, ICCs were excellent (0.763-0.969; all p < 0.001). The Bland-Altman plot showed good agreement between measurements, with narrow limits of agreement. CONCLUSION: Interobserver agreement for SMM measurement at the level of C3 was excellent. Assessment of SMM at the level of C3 is easy and robust and can performed on routinely available imaging in HNC patients.

The value of postoperative anticoagulants to improve flap survival in the free radial forearm flap: a systematic review and retrospective multicentre analysis.

BACKGROUND: Free radial forearm flap (FRFF) reconstruction is a valuable technique in head and neck surgery, which allows closure of large defects while striving to maintain functionality. Anticoagulative drugs are often administered to improve flap survival, although evidence regarding effectiveness is lacking. OBJECTIVE OF REVIEW: To investigate the effectiveness of postoperative anticoagulants to improve survival of the FRFF in head and neck reconstruction. TYPE OF REVIEW: Systematic review and multicentre, individual patient data meta-analysis. SEARCH STRATEGY: MEDLINE, EMBASE, Web of Science and CINAHL were searched for synonyms of 'anticoagulants' and 'free flap reconstruction'. EVALUATION METHOD: Studies were critically appraised for directness of evidence and risk of bias. Authors of the highest quality publications were invited to submit their original data for meta-analysis. RESULTS: Five studies were of adequate quality, and data from four studies (80%) were available for meta-analysis, describing 759 FRFF procedures. Anticoagulants used were as follows: aspirin (12%), low molecular weight dextran (18.3%), unfractioned heparin (28.1%), low molecular weight heparin (49%) and prostaglandin-E1 (2.1%). Thirty-one per cent did not receive anticoagulants. Flap failure occurred in 40 of 759 patients (5.3%) On univariate analysis, use of unfractioned heparin was associated with a higher rate of flap failure. However, these regimens were often administered to patients who had revision surgery of the anastomosis. In multivariate logistic regression analysis, anticoagulant use was not associated with improved flap survival or flap-related complications. CONCLUSIONS: The studied anticoagulative drugs did not improve FRFF survival or lower the rate of flap-related complications. In addition, some anticoagulants may cause systemic complications.

Efficacy of tenofovir and efavirenz in combination with lamivudine or emtricitabine in antiretroviral-naive patients in Europe.

BACKGROUND: The combination of tenofovir and efavirenz with either lamivudine or emtricitabine (TELE) has proved to be highly effective in clinical trials for first-line treatment of HIV-1 infection. However, limited data are available on its efficacy in routine clinical practice. METHODS: A multicentre cohort study was performed in therapy-naive patients initiating ART with TELE before July 2009. Efficacy was studied using ITT (missing or switch = failure) and on-treatment (OT) analyses. Genotypic susceptibility scores (GSSs) were determined using the Stanford HIVdb algorithm. RESULTS: Efficacy analysis of 1608 patients showed virological suppression to <50 copies/mL at 48 weeks in 91.5% (OT) and 70.6% (ITT). Almost a quarter of all patients (22.9%) had discontinued TELE at week 48, mainly due to CNS toxicity. Virological failure within 48 weeks was rarely observed (3.3%, n = 53). In multilevel, multivariate analysis, infection with subtype B (P = 0.011), baseline CD4 count <200 cells/mm³ (P < 0.001), GSS <3 (P = 0.002) and use of lamivudine (P < 0.001) were associated with a higher risk of virological failure. After exclusion of patients using co-formulated compounds, virological failure was still more often observed with lamivudine. Following virological failure, three-quarters of patients switched to a PI-based regimen with GSS <3. After 1 year of second-line therapy, viral load was suppressed to <50 copies/mL in 73.5% (OT). CONCLUSIONS: In clinical practice, treatment failure on TELE regimens is relatively frequent due to toxicity. Virological failure is rare and more often observed with lamivudine than with emtricitabine. Following virological failure on TELE, PI-based second-line therapy was often successful despite GSS <3.

Erythrocyte sedimentation rate as a marker of inflammation and ongoing coagulation in stroke and transient ischaemic attack.

OBJECTIVE: Systemic infection and inflammation have been implicated in the aetiology of thrombotic cerebral events, particularly in younger patients. We decided to determine whether those patients with raised D-dimer levels, indicating continuing thrombosis and fibrinolysis, had evidence of concurrent infection or inflammation as manifested by a raised erythrocyte sedimentation rate (ESR) measured after an ischaemic stroke/transient ischaemic attack (TIA). METHODS: One hundred and forty-eight patients who had suffered either single or recurrent cerebrovascular episodes were analysed. The patients were referred to the thrombosis and haemostasis unit at Johannesburg Hospital for evaluation of their thrombotic profiles, including D-dimer levels. Concurrent infection was assessed by measurement of white cell count (WCC) and ESR. The variable time interval between the date of the most recent cerebrovascular event and the date of venesection was determined. A history was taken, a physical and neurological examination was performed, and a cardiology assessment and neuroimaging studies were done. RESULTS: Raised D-dimer levels correlated significantly with ESR levels (p = 0.0094) in all patients. This was particularly evident when comparing the 70 younger patients (aged less than 45 years) with the 78 older patients (> 45 years) with raised D-dimers (p = 0.0070). When analysing other markers of inflammation/infection in association with raised D-dimer levels and ESR, mean fibrinogen levels were significantly raised at 6.56 g/l (p = 0.0122). An elevated WCC, as a categorical variable, was significantly associated with an elevated ESR (p = 0.0092). CONCLUSION: There is a significant correlation between elevated D-dimer levels (indicating abnormalities of coagulation and fibrinolysis) and markers of inflammatory and/or infective processes. This is particularly evident in black patients below the age of 45 years. These patients are believed to be at decreased risk for generalised atheromatous disease compared with older white patients. The ramifications of these findings are potentially important with regard to thrombotic cerebrovascular disease aetiology, investigation, management and prevention.

Expression of voltage-gated potassium channels decreases cellular protein tyrosine phosphorylation.

Protein tyrosine phosphorylation by endogenous and expressed tyrosine kinases is reduced markedly by the expression of functional voltage-gated potassium (Kv) channels. The levels of tyrosine kinase protein and cellular protein substrates are unaffected, consistent with a reduction in tyrosine phosphorylation that results from inhibition of protein tyrosine kinase activity. The attenuation of protein tyrosine phosphorylation is correlated with the gating properties of expressed wild-type and mutant Kv channels. Furthermore, cellular protein tyrosine phosphorylation is reduced within minutes by acute treatment with the electrogenic potassium ionophore valinomycin. Because tyrosine phosphorylation in turn influences Kv channel activity, these results suggest that reciprocal modulatory interactions occur between Kv channel and protein tyrosine phosphorylation signaling pathways.

p53 gene mutations in radiation-induced thyroid cancer.

Little is known about the role of specific oncogenes and tumor suppressor genes in radiation-induced thyroid cancer (RITC). In thyroid cancer, mutations in the p53 tumor suppressor gene have been largely confined to the more aggressive anaplastic forms. We studied point mutations in the p53 gene in 22 patients exposed in childhood to radiation in the head and neck area who later developed papillary thyroid cancers (RITC). Eighteen thyroid cancer patients without exposure to radiation, selected to match by gender and age the RITC group, were used as the control group. After histological identification, DNA was extracted from paraffin-embedded specimens. Exons 5-8 of p53 were PCR amplified and screened for mutations by single strand conformation polymorphism analysis and cycle sequencing. Four of 22 RITC patients (18%) showed missense point mutations. No missense mutations were found in the cancer control group. The missense mutations in the RITC group occurred at codon 208 in 2 patients, codon 177 in 1, and codon 217 in 1. The mutations were transitions from G to A and C to T. All patients with missense mutations were male and had lymph node involvement. Three of the 4 patients with p53 missense mutations had invasion of the cancer beyond the thyroid capsule compared to 2 of the 17 remaining RITC patients. None of the patients with p53 mutations had distant metastases or recurrence of the tumor. These results suggest that p53 gene point mutations may play a pathogenetic role in some radiation-induced, well differentiated thyroid cancers and in their local spread.

Deletion of the Candida glabrata ERG3 and ERG11 genes: effect on cell viability, cell growth, sterol composition, and antifungal susceptibility.

We have cloned and sequenced the structural genes encoding the delta 5,6 sterol desaturase (ERG3 gene) and the 14 alpha-methyl sterol demethylase (ERG11 gene) from Candida glabrata L5 (leu2). Single and double mutants of these genes were created by gene deletion. The phenotypes of these mutants, including sterol profiles, aerobic viabilities, antifungal susceptibilities, and generation times, were studied. Strain L5D (erg3 delta::LEU2) accumulated mainly ergosta-7,22-dien-3 beta-ol, was aerobically viable, and remained susceptible to antifungal agents but had a slower generation time than its parent strain. L5LUD (LEU2 erg11 delta::URA3) strains required medium supplemented with ergosterol and an anaerobic environment for growth. A spontaneous aerobically viable mutant, L5LUD40R (LEU erg11 delta::URA3), obtained from L5LUD (LEU2 erg11 delta::URA3), was found to accumulate lanosterol and obtusifoliol, was resistant to azole antifungal agents, demonstrated some increase in resistance to amphotericin B, and exhibited a 1.86-fold increase in generation time in comparison with L5 (leu2). The double-deletion mutant L5DUD61 (erg3 delta::LEU2 erg11 delta::URA3) was aerobically viable, produced mainly 14 alpha-methyl fecosterol, and had the same antifungal susceptibility pattern as L5LUD40R (LEU2 erg11 delta::URA3), and its generation time was threefold greater than that of L5 (leu2). Northern (RNA) analysis revealed that the single-deletion mutants had a marked increase in message for the undeleted ERG3 and ERG11 genes. These results indicate that differences in antifungal susceptibilities and the restoration of aerobic viability exist between the C. glabrata ergosterol mutants created in this study and those sterol mutants with similar genetic lesions previously reported for Saccharomyces cerevisiae.

Rat PC12 pheochromocytoma cells synthesize insulin-like growth factor-binding protein-6.

The PC12 cell line established from a rat pheochromocytoma has been extensively studied as a model of neuronal differentiation. Insulin-like growth factor-I (IGF-I) and IGF-II are mitogenic for PC12 cells under serum-starved conditions. IGF activity is modulated by a family of six IGF-binding proteins (IGFBPs). It recently was reported that PC12 cells produced an IGFBP that had a marked preferential binding affinity for IGF-II over IGF-I. We now show that the main IGFBP produced by PC12 cells is rat IGFBP-6 and compare its properties with those of human IGFBP-6. The predominant IGFBP in medium conditioned by undifferentiated and differentiated PC12 cells migrated on sodium dodecyl sulfate-12% polyacrylamide gel electrophoresis with an apparent molecular mass of 22.5-25 kilodaltons and was recognized by polyclonal antiserum to rat IGFBP-6 by immunoblotting. Rat IGFBP-6 mRNA (1.4 kilobases) was detected by Northern hybridization of total RNA extracted from PC12 cells using a rat IGFBP-6 cDNA probe. Rat IGFBP-6, like human IGFBP-6, is O-glycosylated; incubation with neuraminidase, fucosidase, and O-glycanase reduced its apparent molecular mass to 21 kilodaltons. Competitive binding studies of rat and human IGFBP-6 with [125I]IGF-II and unlabeled IGF-II or IGF-I demonstrated that both IGFBPs bound IGF-II with similar affinities (Ka, 1.5-1.8 x 10(11) M-1) and bound IGF-I with approximately 25- to 35-fold lower affinity than IGF-II. Thus, differences in amino acid sequence, such as deletion of nine amino-terminal residues (including two conserved cysteine residues) in rat IGFBP-6 compared with human IGFBP-6, do not alter its binding characteristics. PC12 cells should provide a useful system to define the regulation of IGFBP-6 expression and the role of IGFBP-6 in modulating IGF action.