The role of neck dissection in the setting of chemoradiation therapy for head and neck squamous cell carcinoma with advanced neck disease

Concurrent chemotherapy and radiotherapy (CRT) has become standard treatment for many patients with advanced head and neck squamous cell carcinoma (HNSCC). This has led to controversy concerning the role of neck dissection (ND) in this setting. The current debate is focused on N2-N3 disease and the ability of a clinical complete response to predict the absence of viable cells in the ND specimen. Proponents of a systematic planned ND argue that it improves regional control and possibly disease-specific survival. They assert that a clinical response does not predict the pathologic response, and that in the event of recurrence in the neck, a surgical salvage procedure is unlikely to succeed. Conversely, there are many arguments in favor of performing ND only for patients who have evidence of residual neck disease because of the very low probability of isolated neck recurrence following a complete response. Proponents argue that for complete responders, planned ND is associated with no survival benefit. As planned surgery will only benefit patients with residual disease in the neck alone, there is a high rate of unnecessary ND with its associated morbidity. Another question concerns the appropriate type of ND to be performed. Even if required after chemoradiation, selective ND is oncologically feasible with minimal morbidity. Lastly, robust data from a randomized trial demonstrating the superiority of one approach vs. the other are lacking. After conducting a review of recent literature on the subject, the authors conclude that planned ND is not necessary for patients with complete response because of the availability of improved diagnostic follow up modalities, and the increased sensitivity to CRT of HNSCC, particularly HPV associated tumors.     

In vitro and in vivo demonstration of physically and chemically in situ gelling NIPAAm-based copolymer system

Poly(NIPAAm-co-hydroxyethylmethacarylate (HEMA)) acrylate and poly(NIPAAm-co-cysteine ethyl ester (CysOEt)) were synthesized and characterized by GPC(gel permeation chromatography), rheology, NMR (nuclear magnetic resonance), and Ellman’s method. Upon mixing of these materials in aqueous solution, they formed gels immediately at body temperature owing to temperature-driven physical gelling, and gradually cured by chemical cross-linking through Michael-type addition reactions between thiols and acrylates. The rate of nucleophilic attack in the Michael-type addition reaction was shown to be highly dependent on the mole ratio of thiol to acrylate at neutral pH. Physical and chemical gelation improved the mechanical properties of the materials compared to purely physical gels. In vitro and in vivo results revealed that chemical and physical gels formed stiffer less viscoelastic materials compared to purely physical gels. Physical and chemical gel systems using thermosensitive polymer with acrylates and thermosensitive polymer with thiols showed minimum toxicity.     

Dynamic contrast-enhanced computed tomography to assess early activity of cetuximab in squamous cell carcinoma of the head and neck

Background

Cetuximab, a monoclonal antibody targeting the Epidermal Growth Factor Receptor (EGFR), has demonstrated activity in various tumor types. Using dynamic contrast-enhanced computed tomography (DCE-CT), we investigated the early activity of cetuximab monotherapy in previously untreated patients with squamous cell carcinoma of the head and neck (SCCHN).

Methods

Treatment-naïve patients with SCCHN received cetuximab for 2 weeks before curative surgery. Treatment activity was evaluated by DCE-CT at baseline and before surgery. Tumor vascular and interstitial characteristics were evaluated using the Brix two-compartment kinetic model. Modifications of the perfusion parameters (blood flow F_p, extravascular space v_e, vascular space v_p, and transfer constant PS) were assessed between both time points. DCE data were compared to FDG-PET and histopathological examination obtained simultaneously. Plasmatic vascular markers were investigated at different time points.

Results

Fourteen patients had evaluable DCE-CT parameters at both time points. A significant increase in the extravascular extracellular space v_e accessible to the tracer was observed but no significant differences were found for the other kinetic parameters (F_p, v_p or PS). Significant correlations were found between DCE parameters and the other two modalities. Plasmatic VEGF, PDGF-BB and IL-8 decreased as early as 2 hours after cetuximab infusion.

Conclusions

Early activity of cetuximab on tumor interstitial characteristics was detected by DCE-CT. Modifications of plasmatic vascular markers are not sufficient to confirm anti-angiogenic cetuximab activity in vivo. Further investigation is warranted to determine to what extent DCE-CT parameters are modified and to evaluate whether they are able to predict treatment outcome.     

Risk-assessment and pharmacological prophylaxis of venous thromboembolism in hospitalized patients with chronic liver disease

Introduction

There is a lack of evidence regarding the need for thromboprophylaxis in hospitalized patients with liver disease. The purpose of this study was to evaluate the Padua Predictor Score (PPS) as a risk-stratification tool for the development of venous thromboembolism (VTE) in patients with chronic liver disease.

Methods

This was a retrospective cohort study conducted in an academic medical center in the United States. Consecutive adult patients admitted with chronic liver disease were included. Patients were categorized into two groups based on whether they developed a VTE or not. The risk for VTE in each patient was evaluated using the Padua Predictor Score (PPS). Patients were risk stratified using the PPS score as high-risk (score ≥ 4) and low-risk (score < 4). The risk of VTE based on PPS categorization was evaluated using logistic regression.

Results

A total of 163 patients with liver disease were included in the study cohort. Of these, 18 (11%) developed VTE. Mean PPS was significantly greater in the VTE group than the non-VTE group (5.8 ± 2.0 versus 3.0 ± 2.1, respectively; p < 0.001). In high-risk patients 22% (n = 16/72) developed VTE and in low-risk patients 2% (2/91) developed VTE (p < 0.001). High-risk patients were more likely to have VTE (OR 12.7, 95% CI 2.8 to 57.4, p = 0.001).

Conclusion

The PPS is an effective risk assessment tool for VTE in patients hospitalized with chronic liver disease.     

Assessment of the hygiene-related risks of child illness at selected elementary schools in Nablus city: a cross-sectional survey

Background

The health and safety of children at schools in Palestine are not paid the attention they require. Our objective was to assess the major risks and patterns associated with hygiene and sanitation at selected schools in Nablus in the West Bank.

Efficacy of phthalocyanine tetrasulfonate against mouse-adapted human prion strains

In vitro and in vivo studies have shown that phthalocyanine tetrasulfonate (PcTS), a cyclic tetrapyrrole compound, is an efficient antiscrapie drug. To investigate the spectrum of PcTS against prion diseases, we tested the effect of PcTS on two mouse-adapted human strains. We also tested PcTS in rodents infected with two scrapie strains (139A and 263K). PcTS treatment significantly prolonged mean survival times of all infected animals. These results show that PcTS is effective on different prion strains, confirming its potential use for prion therapy. H. Abdel-Haq and M. Lu contributed equally to this work.     

Mivazerol inhibits intrathecal release of glutamate evoked by halothane withdrawal in rats

Background : Mivazerol is a new and selective α₂-adrenergic receptor agonist devoid of hypotensive effects (1, 2). Previous studies have demonstrated that mivazerol prevents hemodynamic instability during emergence from halothane anesthesia in rats (3). The present study was to determine whether glutamate and aspartate are involved in this action of mivazerol, at the second to third thoracic segments (T2–T3) of the spinal cord.
Methods : In vivo microdialysis in combination with high-performance liquid chromatography (HPLC) was employed in the study. Blood pressure (BP) and heart rate (HR) were recorded along with intrathecal (i.t.) microdialysis perfusion.
Results : BP, HR and i.t. release of glutamate (GLU, pmol/μl) were stable in the rats under 1.1% halothane anesthesia. However, halothane withdrawal immediately increased BP, HR, and i.t. release of GLU, and remained elevated for at least 2 h after withdrawal of halothane. Thirty minutes prior to halothane withdrawal, intravenous (i.v.) infusion of mivazerol (15 μg · kg^–l · h^–) almost completely prevented the increases in HR (Δ18±7 vs Δ79±7 beats/min), and in the i.t. release of GLU (Δ10.3±3.7 vs Δ30.6±5.9; 112% vs 167%). Local i.t. microinjection of mivazerol (2.5 μg/kg) 2 min prior to withdrawal of halothane also blocked the HR responses, as well as on the i.t. release of GLU following halothane withdrawal.
Conclusion : The present study demonstrates that emergence from halothane anesthesia increases i.t. release of GLU, and that mivazerol has an inhibitory effect on the above, through its direct action on the spinal cord.     

Septal choline acetyltransferase immunoreactive neurons: dose-dependent effects of AF64A

Two experiments were performed. In the first, the cholinotoxin, AF64A (0.5, 1.0 or 1.5 nmol/ventricle), or vehicle (3.0 microliters) was injected (ICV) bilaterally into male rats (n = 23). Choline acetyltransferase (ChAT) immunoreactive (IR) perikarya in the four subgroups of the septal complex were visualized by immunocytochemistry (PAP method) 28 days postinjection, and counted using a microprojector (x40). The 0.5 nmol/ventricle dose of AF64A significantly reduced (31%) the number of ChAT-IR cell bodies in the intermediate subgroup (rostral extension of the nucleus basalis/substantia innominata). Higher doses did not produce additional reductions. The highest dose (1.5 nmol/ventricle) of AF64A resulted in significant decreases in ChAT-IR cell bodies in the dorsal (51%) and midline (35%) subgroups (medial septum), but did not affect the number of ventral subgroup (diagonal band of Broca) ChAT-IR neurons. In the second experiment, electrolytic lesions were placed in the corpus callosum, cingulum and overlying cingulate gyrus, in order to simulate the nonselective damage seen following the 1.5 nmol/ventricle dose of AF64A. In comparison to the surgical controls (n = 3), the electrolytic lesions (n = 6) failed to significantly affect the number of ChAT-IR perikarya in any of the septal subdivisions. Thus the distinct subgroups of septal ChAT-IR neurons are differentially sensitive to the toxic effects of ICV administered AF64A: intermediate much greater than dorsal greater than midline much greater than ventral subgroup.