Porcine urinary bladder matrix: a retrospective study and establishment of protocol

OBJECTIVE

To summarise our experience with porcine urinary bladder matrix extracellular matrix (UBM) for the treatment of diabetic, venous, ischaemic or decubitus ulcerations and to outline appropriate protocol for its application.

METHOD

A retrospective review was also conducted on all patients who received UBM (MatriStem; A Cell, Inc.) from January to December 201 I. Information regarding patient demographics, wound aetiology and location, as well as any prior treatments and follow-up data,were collected and reviewed from patients' medical records.

RESULTS

Thirty-four patients were evaluated for this study. Mean patient age was 62.4 + 13.4 years (range 29-88 years) and 76% (n = 26) were male.The most common comorbidities were peripheral neuropathy (n = 20), diabetes mellitus type 2 (n = 19) and hypertension (n= 13). Mean wound duration prior to UBM application was 25.5 43.5 weeks, and mean time to healing following initial application was 9.8 9.3 weeks. All patients treated with UBM progressed to full healing.

CONCLUSION

After addressing modifiable risk factors, our study suggests UBM is effective in the treatment of acute and recalcitrant diabetic or venous ulcerations when applied correctly with an appropriate dressing.

DECLARATION OF INTEREST

There were no external sources of funding for this study.The authors have no conflicts of interest to declare.

Search for a new gauge boson in electron-nucleus fixed-target scattering by the APEX experiment

We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling α' to electrons. Such a particle A' can be produced in electron-nucleus fixed-target scattering and then decay to an e + e- pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175-250 MeV, found no evidence for an A'→ e+ e- reaction, and set an upper limit of α'/α ~/= 10(-6). Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.

Estimates of length of neonatal stay for very premature babies in the UK

OBJECTIVE

To describe simple estimates of likely duration of stay for very premature babies born in the UK and discharged home.

DESIGN

Statistical modelling of data from thirty neonatal units in a geographically defined region of the UK.

PARTICIPANTS

All babies born at 23 to 32 completed weeks of gestation in 2005, 2006 and 2007 who were discharged home with the expectation that they would survive.

MAIN OUTCOME MEASURE

Total duration of stay in the neonatal service.

RESULTS

5528 babies were initially identified. 558 (10.1%) who died or who did not follow a normal care pathway were excluded. In a further 27, data were either missing or inadequate, leaving a study population of 4702 babies. As expected, gestation and birthweight exhibited strong influence on length of stay. Of the other variables tested, initial reason for admission (need for early respiratory support) showed the most consistent association. These factors were combined to produce predictive tables. The predictive performance of the tables was found to fit the data well for various groups, with the exception of multiple births who tended to have longer stays. However, when tested against individual units, much greater variation was seen independent of unit size and case mix.

CONCLUSION

The prediction tables should permit parents to make sensible estimates about the duration of their baby's stay in the neonatal service; however, there appear to be important differences between units. The variation noted in length of stay between otherwise similar units merits further investigation.

Environmental controls on stomatal conductance in a shrub of the humid tropics

Leaves of Piper hispidum, a shrub native to the lowland tropics of Mexico, have a strong stomatal response to humidity that results in similar rates of water loss under a wide range of leaf-to-air water-vapor concentration gradients. Stomatal conductance of these leaves is insensitive to CO(2) concentration and increases in response to high humidity even in the dark.

Relative biological damage and electron fluence in and out of a 6 MV photon field

Scattered radiation in the penumbra of a megavoltage radiation therapy beam can deposit a non-negligible dose in the healthy tissue around a target volume. The lower energy of the radiation in this region suggests that its biological effectiveness might not be the same as that of the open beam. In this work, we determined the relative biological damage in normal human fibroblasts after megavoltage irradiation in two geometries. The first was an open-beam irradiation and the second was a blocked configuration in which only scattered radiation could reach the target cells. The biological damage was evaluated by the gamma-H2AX immunofluorescence assay, which is capable of detecting DNA double-strand breaks in individual cells. We report that the scattered radiation is more effective at producing biological damage than the open beam radiation. We found a 27% enhancement in the net mean nuclear gamma-H2AX fluorescence intensity at 2 Gy and a 48% enhancement at 4 Gy. These findings are of interest due to the increased doses of penumbral radiation close to target volumes both in dose escalation studies and in IMRT treatment deliveries where high dose gradients exist for the purpose of conformal avoidance of healthy tissues.

Estimation of renal function -- what is appropriate in cancer patients?

AIMS

To compare the accuracy of renal assessment in patients with cancer using radioisotope glomerular filtration rate (GFR), urine collection for creatinine clearance, Cockroft-Gault, Modification of Diet in Renal Disease (MDRD) and Wright formulae.

MATERIALS AND METHODS

Measurements of isotope GFR from 367 patients were compared with estimates from the described methods (Cockroft-Gault, MDRD, Wright). An analysis including a further 252 patients with an isotope GFR < or = 50 ml/min was also carried out.

RESULTS

The Wright formula was the most accurate form of estimating renal function for the first study group. The formulae were similar in accuracy in the second study group.

CONCLUSIONS

The Wright formula is the most accurate form of estimation of renal function in comparison with the isotope GFR for cancer patients. When there is a large proportion of patients with a low isotope GFR (< or = 50 ml/min), the formulae have similar accuracy.