Validity of single‐point assessments for determining leg pulse wave velocity in sitting and supine positions

There has been a great deal of interest into the effects of prolonged sitting on lower limb vascular function. However, most studies use flow‐mediated dilation which is technically challenging. A simpler technique is pulse wave velocity (PWV) which can be estimated at any single arterial site of interest using a number of different calculations (Bramwell–hill [PWV_BH], β‐stiffness index [PWV_β] and blood flow [PWV_BF]). Findings from this technique would be better inferred if they compare to a standard criterion 2‐point PWV assessment. The current study used ultrasound to determine which estimation of single‐point PWV is most valid. The criterion was traditional ECG‐gated 2‐point (superficial femoral [SF]‐posterior tibialis [PT]) PWV. Single‐point estimates were calculated at the SF and PT arteries in both supine and seated positions. Single‐point PWV was considered valid if the aSEE was <1.0 m·s. Findings show that for both postural positions, the absolute standard error of estimates (aSEE) criterion of <1.0 m·s was not achieved in either the PT or SF arteries using any of the single‐point PWV calculations. However, single‐point calculations consistently demonstrated the lowest error at the SF artery using PWV_β in both supine (SF aSEE = 1.7 vs. PT 2.7 m·s) and seated (SF aSEE = 1.5 vs. PT 3.0 m·s) positions. All single‐point ΔPWV (supine – seated) calculations were higher in sitting, with PWV_β having the closest agreement (ΔSF aSEE 1.7 m·s) to the 2‐point criterion. Single‐point PWV calculations do not directly reflect regional 2‐point PWV. However, they are sensitive to change when moving from supine to seated positions.     

Reduction-responsive molecularly imprinted nanogels for drug delivery applications

Degradable molecularly imprinted polymers (MIPs) with affinity for S-propranolol were prepared by the copolymerization of methacrylic acid as functional monomer and a disulfide-containing cross-linker, bis(2-methacryloyloxyethyl)disulfide (DSDMA), using bulk polymerization or high dilution polymerization for nanogels synthesis. The specificity and the selectivity of DSDMA-based molecularly imprinted polymers toward S-propranolol were studied in batch binding experiments, and their binding properties were compared to a traditional ethylene glycol dimethacrylate (EDMA)-based MIP. Nanosized MIPs prepared with DSDMA as crosslinker could be degraded into lower molecular weight linear polymers by cleaving the disulfide bonds and thus reversing cross-linking using different reducing agents (NaBH₄, DTT, GSH). Turbidity, viscosity, polymer size and IR-spectra were measured to study the polymer degradation. The loss of specific recognition and binding capacity of S-propranolol was also observed after MIP degradation. This phenomenon was applied to modulate the release properties of the MIP. In presence of GSH at its intracellular concentration, the S-propranolol release was higher, showing that these materials could potentially be applied as intracellular controlled drug delivery system.

Degradable molecularly imprinted polymers were prepared using redox sensitive cross-linkers and applied as intracellular drug delivery system to address the biocompatibility and cytotoxicity issues encountered with these synthetic polymers.     

Lead poisoning in telephone cable strippers: A new setting for an old problem

Lead poisoning among workers processing lead sheathed telephone cable was identified at five worksites. High blood lead levels (BLLs) were identified during the medical evaluation of symptomatic workers following employer mandated air monitoring and through employer mandated blood lead levels. Once high BLLs were identified, governmental agencies became involved at every site, either as a result of worker complaints to OSHA or as a registry reporting mechanism. Workplace evaluation revealed significant overexposure to lead, particularly among workers mechanically stripping the lead sheaths. After intervention by a government agency, four of the workplaces chose to stop lead cable processing. Because the ongoing replacement of lead sheathed telephone cable with fiber optics may be continuing in many areas of the country, there is concern that the clusters we have identified represents a widespread and little recognized setting for lead overexposure. Recommendations for preventing overexposure to lead in this setting are given. © 1996 Wiley-Liss, Inc.     

Effect of matrigel on the tumorigenicity of human breast and ovarian carcinoma cell lines

The effect of Matrigel, a solubilised tissue basement membrane extract, has been investigated on the tumorigenicity of 3 breast (MCF-7, T47D and MDA.MB.231) and 5 ovarian [PEO1, PEO1 cDDPr, PEO4, PEO14 and OV(hyg)CAR3] carcinoma cell lines. In the absence of Matrigel, the PEO14 and MDA.MB.231 cell lines produced take rates of 30% and 50%, respectively, while the other cell lines either did not develop or only occasionally developed as tumours. With Matrigel, 100% take rates were achieved for 7 of the 8 cell lines (MCF-7, T47D, MDA.MB.231, PEO1, PEO1 cDDPr, PEO4 and PEO14); in the remaining cell line [OV(hyg)CAR3] 2/6 (33%) tumours grew. Xenografts established with Matrigel could be transferred into recipient animals and grown in the absence of Matrigel, suggesting that Matrigel is necessary only for initial establishment of tumours. Furthermore, cells which had been re-established from a T47D xenograft and then inoculated into mice without Matrigel showed a take rate greater than that of the original cell line but less than that of the xenograft. In conclusion, Matrigel has proven to be extremely useful in establishing a variety of cell lines as xenografts. © 1996 Wiley-Liss, Inc.     

Consumer Audit of Community Learning Disability Teams

In 1993, the four Community Learning Disability Teams in Sandwell set up Quality Standards to govern their function. A consumer audit was undertaken to assess views of users and carers on delivery and operation of the service. The results were presented to the teams who modified their practice accordingly. Some of the difficulties encountered in carrying out consumer audit with users who have severe learning disabilities are described.