Is ultrasound alone sufficient for imaging superficial lobe benign parotid tumours before surgery?

Ultrasound (US) is a valuable technique for the assessment of salivary gland disease and regional nodes. When used in combination with fine needle aspiration cytology (FNAC) or core biopsy it has a high sensitivity and specificity in the diagnosis of tumours. The role of additional cross-sectional imaging (computed tomography (CT) or magnetic resonance (MR)) to help with the diagnosis of benign parotid tumours is questionable except when there is deep lobe extension or the suggestion of malignancy. We investigated 37 FNAC-confirmed benign parotid tumours in patients who had undergone both US and CT or MRI investigations, to find out whether cross-sectional imaging had provided any further useful diagnostic information before operation. Three patients had bilateral Warthin tumours. Tumours ranged in size from 11 to 45 mm (mean 22). Of the 37 patients 35 (95%) had a clearly delineated mass in the superficial lobe of the parotid on US and no further information was gained from additional CT or MRI. On US 34 patients (92%) had features suggestive of a benign tumour, and three had features suggestive of malignancy but these were found to be benign on FNAC and after operation. CT or MRI confirmed these suspicious findings. In two different patients the deep margin was not visible on US (suggestive of deep lobe extension) and this was confirmed on MRI. The mean time delay between US and CT or MRI was four weeks (range 1-44). These results suggest that additional imaging is not required in most patients with a sonographically and FNAC confirmed benign lesion confined to the superficial lobe of the parotid and confirmed by FNAC or biopsy examination.

Randomised controlled trial of thermostatic mixer valves in reducing bath hot tap water temperature in families with young children in social housing

OBJECTIVES

To assess the effectiveness of thermostatic mixing valves (TMVs) in reducing bath hot tap water temperature, assess acceptability of TMVs to families and impact on bath time safety practices.

DESIGN

Pragmatic parallel arm randomised controlled trial.

SETTING

A social housing organisation in Glasgow, Scotland, UK.

PARTICIPANTS

124 families with at least one child under 5 years.

INTERVENTION

A TMV fitted by a qualified plumber and educational leaflets before and at the time of TMV fitting.

MAIN OUTCOME MEASURES

Bath hot tap water temperature at 3-month and 12-month post-intervention or randomisation, acceptability, problems with TMVs and bath time safety practices.

RESULTS

Intervention arm families had a significantly lower bath hot water temperature at 3-month and 12-month follow-up than families in the control arm (3 months: intervention arm median 45.0°C, control arm median 56.0°C, difference between medians, -11.0, 95% CI -14.3 to -7.7); 12 months: intervention arm median 46.0°C, control arm median 55.0°C, difference between medians -9.0, 95% CI -11.8 to -6.2) They were significantly more likely to be happy or very happy with their bath hot water temperature (RR 1.43, 95% CI 1.05 to 1.93), significantly less likely to report the temperature as being too hot (RR 0.33, 95% CI 0.16 to 0.68) and significantly less likely to report checking the temperature of every bath (RR 0.84, 95% CI 0.73 to 0.97). Seven (15%) intervention arm families reported problems with their TMV.

CONCLUSIONS

TMVs and accompanying educational leaflets are effective at reducing bath hot tap water temperatures in the short and longer term and are acceptable to families. Housing providers should consider fitting TMVs in their properties and legislators should consider mandating their use in refurbishments as well as in new builds.

Studies on cellular accumulation of satraplatin and its major metabolite JM118 and their interactions with glutathione

Before the active form of a Pt drug reaches its major pharmacological target in the cell nucleus, the Pt complex has to accumulate in cells, and during its transportation into cells and inside cells, it reacts with various biomolecules. Satraplatin is the first orally administered Pt drug under active clinical investigation. The major metabolite of this Pt(IV) complex is its Pt(II) analogue (JM118), which also has significant anticancer properties. Here we report the role of active transport in cellular entry of satraplatin and JM118 and interactions of these Pt complexes with glutathione. The results reveal that the organic cation transporters may play a more important role in the mechanism of cytotoxicity of JM118 than in the cytotoxicity of cisplatin. In contrast, satraplatin is a poor substrate of these transporters. In addition, satraplatin reacts with glutathione with the rate markedly lower than JM118 and cisplatin. Interestingly, satraplatin can be activated by glutathione allowing it to react with DNA, although to a much lower extent than in the case of another Pt(IV) drug tetraplatin.

New reduction pathways for ctc-[PtCl2(CH3CO2)2(NH3)(Am)] anticancer prodrugs

Reduction of anticancer prodrugs such as ctc-[PtCl₂(CH₃CO₂)₂(NH₃)(Am)] can yield three products in addition to the expected cis-[PtCl₂(NH₃)(Am)], by the loss of two axial ligands, one axial and one equatorial ligand, or two equatorial ligands.

Is glutathione the major cellular target of cisplatin? A study of the interactions of cisplatin with cancer cell extracts

Cisplatin is an anticancer drug whose efficacy is limited because tumors develop resistance to the drug. Resistant cells often have elevated levels of cellular glutathione (GSH), believed to be the major cellular target of cisplatin that inactivates the drug by binding to it irreversibly, forming [Pt(SG)(2)] adducts. We show by [(1)H,(15)N] HSQC that the half-life of (15)N labeled cisplatin in whole cell extracts is approximately 75 min, but no Pt-GSH adducts were observed. When the low molecular mass fraction (<3 kDa) of the extracts was incubated with cisplatin, binding to GSH was observed probably due to removal of high molecular mass platinophiles. Two-thirds of the Pt adducts formed in whole cell extracts, had a molecular mass >3 kDa. [Pt(SG)(2)] cannot account for more than 20% of the Pt adducts. The concentration of reduced thiols in the high molecular mass fraction of the extracts is six times higher than in the low molecular mass fraction.

Trans labilization of am(m)ine ligands from platinum(II) complexes by cancer cell extracts

Cisplatin, cis-[Pt(NH(3))(2)Cl(2)], is an effective anticancer agent in wide clinical use whose efficacy is affected by cellular interactions with sulfur-containing nucleophiles. These interactions can potentially enhance the efficacy of the drug by mediating its delivery to nuclear DNA or inactivate the drug by binding to it irreversibly or by labilizing the NH(3) ligands. Despite the potential importance of trans-labilization reactions in the mechanism of action of the drug, few detailed studies on trans labilization of the ammines have been conducted. We used 2D NMR to show that some trans labilization occurs in proliferating cells and that aqueous extracts of cancer cells labilized 20% of the amine ligands of cis-[PtCl(2)((13)CH(3)NH(2))(2)] after a 12-h incubation. Both low molecular mass nucleophiles (less than 3 kDa) and high molecular mass nucleophiles (more than 3 kDa) labilize the amines with similar efficiency. Studies with model compounds show that thiols and thioethers bind to platinum(II) at similar rates, but thioethers are significantly more efficient at labilizing the am(m)ine at lower pH. N-Acetylcysteine is a more efficient trans-labilizer than glutathione, suggesting that the displacement of the amine proceeds through an associative mechanism. The lag time, the time that elapses from the formation of the Pt-S bond till the release of the amine trans to the sulfur, depends on the pH (for thiols), increasing at lower pH. Quantification of the platinum adducts obtained from incubation of cisplatin with cell extracts indicates that two thirds of the platinum is bound to cellular components with molecular mass greater than 3 kDa.

Peculiar mechanistic and structural features of the carboplatin-cytochrome c system revealed by ESI-MS analysis

Carboplatin (CPT), today the most important platinum(II) anticancer drug, manifests an extreme kinetic inertness, in vitro, at physiological pH; the actual mechanisms for its activation inside cells are still poorly understood. We show here that horse heart cytochrome c reacts with CPT, leading to the formation of stable platinum/protein adducts. The two major CPT-cytochrome c species resulting from the aforementioned reaction were characterised by electrospray ionisation mass spectrometry (ESI-MS). Notably, both these adducts have the ability to react with guanosine 5'-monophosphate (5'-GMP), giving rise to the respective cytochrome c-CPT-5'-GMP ternary complexes. Additional ESI-MS measurements on enzymatically cleaved cytochrome c adducts suggest that protein platination probably occurs at Met65. The mechanistic implications of these findings are discussed.

Phase I study of the safety and pharmacokinetics (PK) of paclitaxel or paclitaxel with carboplatin administered in combination with pazopanib (GW786034)

14118

Background: Pazopanib is a potent and selective multi-targeted receptor tyrosine kinase inhibitor of VEGFR-1, VEGFR-2, VEGFR-3, PDGFR-a/β, and c-kit. Pazopanib also is a moderate inhibitor of CYP2C8 and CYP3A4 in vitro. Paclitaxel (T), a substrate for CYP2C8 and CYP3A4, administered alone and in combination with carboplatin (Cb) is highly active in breast, NSCLC, and ovarian cancers. The additive benefit of the anti-VEGF agent bevacizumab with T or T-Cb in breast and NSCLC provides strong rationale for use of a multi-targeted TKI with T or T-Cb. Methods: Pts with advanced cancer (ECOG PS 0–1) were eligible. Dose escalation was split into Part 1 [T (15–80 mg/m2) days 1, 8, 15 q 28 days plus pazopanib (400–800 mg) QD starting on day 2 of cycle 1] and Part 2 [T (80- 225 mg/m2) plus Cb AUC 6 q 21 days plus pazopanib 800 mg QD starting on day 2 of cycle 1]. Safety, PK, and clinical response were evaluated. Dose escalation occurred in cohorts of 3–6 pts based on dose-limiting toxicities (DLTs) and PK. Results: 12 pts in Part 1 received the following pazopanib/T doses (n = pts): 400 mg/15 mg/m2 (3), 800 mg/15 mg/m2 (3), 800mg /50 mg/m2 (3), 800mg /80 mg/m2 (3). Preliminary data were available from 9 pts in Part 1. Selected mean PK results for T are shown. 4 pts in Part 2 received 800mg /175 mg/m2/AUC 6 of pazopanib/T/Cb (data not yet available). Most common AEs (>20%) in Part 1 were Gr 1/2 and consisted of fatigue, diarrhea, anorexia, nausea, vomiting, dysgeusia, AST elevation, rash, hypertension, and cough; Gr 3 diarrhea was reported in 1 pt. The 800mg pazopanib/80 mg/m2 T cohort in Part 1 is being expanded to 6 pts due to a DLT (dose delay of > 2 wks due to an abscess). Best response (n=6 pts) in Part 1 was SD (83%) (range 1–5 cycles). Conclusions: Concomitant administration of pazopanib increased paclitaxel mean Cmax and AUC(0–8) approximately 20–35%. Determination of the MTR in Parts 1 and 2 is ongoing. These findings warrant further studies at therapeutic doses of pazopanib, paclitaxel, and carboplatin. [Table: see text]

No significant financial relationships to disclose.