SDF-1 and PDGF enhance alphavbeta5-mediated ERK activation and adhesion-independent growth of human pre-B cell lines

CD23 acts through the alphavbeta5 integrin to promote growth of human pre-B cell lines in an adhesion-independent manner. alphavbeta5 is expressed on normal B-cell precursors in the bone marrow. Soluble CD23 (sCD23), short CD23-derived peptides containing the arg-lys-cys (RKC) motif recognized by alphavbeta5 and anti-alphavbeta5 monoclonal antibodies (MAbs) all sustain growth of pre-B cell lines. The chemokine stromal cell-derived factor-1 (SDF-1) regulates key processes during B-cell development. SDF-1 enhanced the growth-sustaining effect driven by ligation of alphavbeta5 with anti-alphavbeta5 MAb 15F-11, sCD23 or CD23-derived RKC-containing peptides. This effect was restricted to B-cell precursors and was specific to SDF-1. The enhancement in growth was associated with the activation of extracellular signal-regulated kinase (ERK) and both these responses were attenuated by the MEK inhibitor U0126. Finally, platelet-derived growth factor also enhanced both alphavbeta5-mediated cell growth and ERK activation. The data suggest that adhesion-independent growth-promoting signals delivered to B-cell precursors through the alphavbeta5 integrin can be modulated by cross-talk with receptors linked to both G-protein and tyrosine kinase-coupled signalling pathways.

Incidence of MRSA surgical-site infection in MRSA carriers in an orthopaedic trauma unit

We examined the incidence of infection with methicillin-resistant Staphylococcus aureus (MRSA) in patients admitted to the Leicester Royal Infirmary Trauma Unit between January 2004 and June 2006. The influence of MRSA status at the time of their admission was examined, together with age, gender and diagnosis, using multi-variant analysis. Of 2473 patients, 79 (3.2%) were MRSA carriers at the time of admission and 2394 (96.8%) were MRSA-negative. Those carrying MRSA at the time of admission were more likely to develop surgical site infection with MRSA (7 of 79 patients, 8.8%) than non-MRSA carriers (54 of 2394 patients, 2.2%, p < 0.001). Further analysis showed that hip fracture and increasing age were also risk factors with a linear increase in relative risk of 1.8% per year.

MRSA carriage at admission, age and the pathology are all associated with an increased rate of developing MRSA wound infection. Identification of such risk factors at admission helps to target health-care resources, such the use of glycopeptide antibiotics at induction and the ‘building-in’ of increased vigilance for wound infection pre-operatively.

Prospective comparison of subcutaneous to intravenous administration of bortezomib in patients with multiple myeloma: Pharmacokinetics, efficacy and toxicity

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Bortezomib (Bz) is a novel proteasome inhibitor that is registered for treatment of relapsed or refractory MM as an IV bolus injection. Animal toxicology studies have indicated good local tolerability and an acceptable PK profile of SC injection of Bz supporting together with preliminary clinical data the exploration of this route of administration in humans. We conducted a randomized trial to compare pharmacokinetics/pharmacodynamics (PK/PD), toxicity and efficacy of SC and IV injections of Bz, both at standard dose of 1.3 mg/m2 twice weekly for 2 wks (day 1–4-8–11), with 1 wk rest, for up to 8 cycles. From 01/06 to 10/06, 24 pts with relapsed/refractory MM were randomized to receive Bz either IV (arm A, n = 12) or SC (arm B, n = 12); Patients received a median number of 5 cycles in both groups. The local tolerance of SC injections was good. Response rates were similar in both groups (CR+VGPR/PR/MR: 3/2/1 in arm A, vs 3/2/2 patients in arm B. Grade 3 / 4 adverse events occurred in 7 cases in arm A, vs 5 in arm B, leading to study discontinuation in 5 and 3 cases, respectively. PK analysis: average plasma Cmax values were lower for SC as compared to IV (15 ng/mL at day 1, and 23 at day 11, vs 130 and 127, p < .001), but overall systemic availability as measured by plasma AUC values were comparable between SC and IV administration for both day 1 & 11 (145 and 388 ng.h/mL, vs 133 and 386, p =.7 & .98, respectively). Average Tmax values were less than 1 hour for both routes. PD analysis (20S proteasome inhibition): average area under the curve for effect (AUE) values were comparable between SC and IV administration both for day 1 & 11 (761 and 1,324 %.h, vs 1,089 and 1,110, p = .29 & .54, respectively), while average Emax values were lower for SC administration (Emax day 1 & day 11 SC, 58 and 56%, vs 72 and 69% IV, p =.003 & .01 respectively). The overall systemic availability of Bz was comparable between SC and IV administration for both day 1 and 11. Similarly, the average AUE results were comparable between SC and IV, while average Emax was lower for SC administration. Response rates were identical in the 2 groups of patients, with similar toxicity profile. Given the good local tolerance of SC injection, this route of administration could be an alternative option to IV injection.

[Table: see text]

Open-label study to assess effect of omeprazole (O) on pharmacokinetics of bortezomib (B) in subjects with advanced solid tumors, NHL, or multiple myeloma

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Background: Omeprazole (O), an over-the-counter proton pump inhibitor, is also a potent inhibitor of cytochrome P450 (CYP) 2C19, an enzyme responsible for the metabolism of many drugs including bortezomib (B; VELCADE®). This study sought to evaluate potential drug interactions between omeprazole and bortezomib. Methods: Between January 2005 and August 2006, 18 men and 9 women were randomized to receive B 1.3 mg/m2 iv alone on Days 1, 4, 8, and 11 of a 21-day cycle or B + O 40 mg (2 x 20 mg capsules) on the mornings of Days 6–10 and the evening of Day 8 in Cycle 1, crossing over to receive the other treatment in Cycle 2. Baseline plasma samples were collected before B administration on Day 1 Cycle 1 and Day 8. Results: 17 patients completed both cycles and were evaluable for pharmacokinetics (PK) analysis. The PK of bortezomib with and without omeprazole overlapped and the peak concentrations and time to reach peak concentrations were similar (Table). As observed in other studies of B, there was a high degree of inter-subject variability (B alone, %CV = 64.7; B + O %CV = 60.3); however, differences in mean exposure values between treatments were within the degree of inter- subject variation. There was no increase in adverse events related to bortezomib as a result of treatment with O. In both groups over 95% of patients had over 80% 20S proteasome inhibition. No meaningful relationships were apparent among CYP gene polymorphisms (2C19, 2D6, 3A4, 3A5) and PK endpoints (AUC8 and Cmax) or pharmacodynamic (PD) endpoints (AUE72 and Emax) in either group or both groups combined. Conclusion: Addition of O to B did not alter PK, PD or safety parameters. Clinically significant drug interaction is unlikely when B is co-administered with O or other CYP2C19 inhibitors.

[Table: see text]

No significant financial relationships to disclose.

Transtonsillar drainage of parapharyngeal abscess

We report a parapharyngeal abscess in an adult patient that was drained transorally by performing ipsilateral tonsillectomy and aspirating the pus through the tonsillar bed. This approach is unusual as most previous studies report the aspiration of such abscesses through the lateral pharyngeal mucosa. In addition, the majority of these studies are limited to pediatric cases. Our approach was effective and resulted in a rapid resolution of the symptoms. The management and different approaches to parapharyngeal abscess are discussed, and the literature is reviewed.

Studies on Anion Promoted Titania.1: Preparation, Characterization, and Catalytic Activity toward Alcohol and Cumene Conversion Reactions of Phosphated Titania

Phosphate impregnated titania samples with varying amount of phosphate have been prepared by solid-solid kneading as well as aqueous impregnation method. All the samples are characterized by XRD, TG-DTA, and N(2) adsorption-desorption isotherm. Surface area is found to increase with the increase in phosphate content up to 7.5 wt% loading and thereafter decreases. The average pore diameter and crystallite size of titania decreases with the addition of phosphate. However, total acidity (determined by base adsorption method) and the catalytic activity increases with the increase in phosphate content up to 10 wt%. Phosphated samples prepared using phosphoric acid as the source of phosphate exhibit higher acidity compared to the samples prepared using (NH(4))(3)PO(4). However, the sample prepared from (NH(4))(3)PO(4) shows the presence of both acid and basic sites. Though from the cumene conversion study it is understood that phosphated samples contain both Lewis and Brønsted acid sites, the latter predominates over the former. Copyright 1999 Academic Press.

A transethmoid transorbital foreign body

A case of an unusual foreign body, the bristle end of a broken toothbrush which was removed for the ethmoid sinus complex is presented.

Measurement of turbulent fluctuations in high-speed flows using hot wires and hot films

A hot wire has a limited life in high-speed wind-tunnel flows because it is typically subjected to large dynamic loads. As a consequence hot films and modified hot wires are frequently used for turbulence measurements in such flows. However, the fluctuation sensitivities of such probes are reduced because of various factors, leading to erroneous results. This paper described the results of tests on some sensors in both subsonic and supersonic boundary-layer flows. A simple technique to determine dynamic calibration correction factors for the sensitivities is also presented.