Utility of stereolithographic models in osteocutaneous free flap reconstruction of the head and neck

Background Stereolithographic (SLA) models have become a valuable resource in preoperative planning in maxillofacial reconstruction. The objective of this study was to perform a defect specific analysis of the utility of SLA models. The goal was to determine the manner in which the perceived benefit of preoperative modeling translates to measurable clinical advantages. Methods Patients who underwent reconstruction of defects of the mandible or midface using SLA modeling between 2006 and 2011 were identified through billing records. Based on the nature and extent of bony defect, cases requiring nearly identical reconstruction, but without modeling, were matched case by case for comparison. Given the presumed efficiency of SLA modeling, a comparison of total and reconstructive operative times was performed to see if this could offset the cost of the model. Results There were 10 patients each in the "model" and "nonmodel" group. No significant differences were observed for total operative time between groups. Surprisingly, the total reconstructive time was lower in the group not using SLA models (p = 0.05). Conclusions SLA models provide several operative planning advantages, but did not appear to decrease operative time enough to sufficiently offset the cost of the model in this group.

Incidence and location of positive nonsentinel lymph nodes in head and neck melanoma

BACKGROUND

The complex lymphatic drainage in the head and neck makes sentinel lymph node biopsy (SLNB) for melanomas in this region challenging. This study describes the incidence, and location of additional positive nonsentinel lymph nodes (NSLN) in patients with cutaneous head and neck melanoma following a positive SLNB.

METHODS

A retrospective review was performed using a single institution prospective database. Patients with a primary melanoma in the head or neck with a positive cervical SLNB were identified. The lymphadenectomy specimen was divided intraoperatively into lymph node levels I-V, and NSLN status determined for each level.

RESULTS

Of 387 patients with melanoma of the head and neck who underwent cervical SLNB, 54 had a positive SLN identified (14%). Thirty six patients (67%) underwent immediate completion lymph node dissection (CLND) of whom eight patients (22%) had a positive NSLN. The remaining 18 patients (33%) did not undergo CLND and were observed. Half of positive NSLNs (50%) were in the same lymph node level as the SLN and 33% were in an immediately adjacent level; only two patients were found to have NSLNs in non-adjacent levels. The only factor predictive of NSLN involvement was the size of the tumor deposit in the SLN>0.2 mm (p = 0.05). Superficial parotidectomy at CLND revealed metastatic melanoma only in patients with a positive parotid SLN.

CONCLUSIONS

A positive NLSN was identified in 22% of patients undergoing CLND after a positive SLNB. The majority of positive NSLNs are found within or immediately adjacent to the nodal level containing the SLN.

Astronomical algorithms for automated analysis of tissue protein expression in breast cancer

BACKGROUND

High-throughput evaluation of tissue biomarkers in oncology has been greatly accelerated by the widespread use of tissue microarrays (TMAs) and immunohistochemistry. Although TMAs have the potential to facilitate protein expression profiling on a scale to rival experiments of tumour transcriptomes, the bottleneck and imprecision of manually scoring TMAs has impeded progress.

METHODS

We report image analysis algorithms adapted from astronomy for the precise automated analysis of IHC in all subcellular compartments. The power of this technique is demonstrated using over 2000 breast tumours and comparing quantitative automated scores against manual assessment by pathologists.

RESULTS

All continuous automated scores showed good correlation with their corresponding ordinal manual scores. For oestrogen receptor (ER), the correlation was 0.82, P<0.0001, for BCL2 0.72, P<0.0001 and for HER2 0.62, P<0.0001. Automated scores showed excellent concordance with manual scores for the unsupervised assignment of cases to 'positive' or 'negative' categories with agreement rates of up to 96%.

CONCLUSION

The adaptation of astronomical algorithms coupled with their application to large annotated study cohorts, constitutes a powerful tool for the realisation of the enormous potential of digital pathology.

Update on World Health Organization HIV drug resistance prevention and assessment strategy: 2004-2011

The HIV drug resistance (HIVDR) prevention and assessment strategy, developed by the World Health Organization (WHO) in partnership with HIVResNet, includes monitoring of HIVDR early warning indicators, surveys to assess acquired and transmitted HIVDR, and development of an accredited HIVDR genotyping laboratory network to support survey implementation in resource-limited settings. As of June 2011, 52 countries had implemented at least 1 element of the strategy, and 27 laboratories had been accredited. As access to antiretrovirals expands under the WHO/Joint United Nations Programme on HIV/AIDS Treatment 2.0 initiative, it is essential to strengthen HIVDR surveillance efforts in the face of increasing concern about HIVDR emergence and transmission.

Surveillance of transmitted HIV-1 drug resistance in Gauteng and KwaZulu-Natal Provinces, South Africa, 2005-2009

Surveillance of human immunodeficiency virus type 1 transmitted drug resistance (TDR) was conducted among pregnant women in South Africa over a 5-year period after the initiation of a large national antiretroviral treatment program. Analysis of TDR data from 9 surveys conducted between 2005 and 2009 in 2 provinces of South Africa suggests that while TDR remains low (<5%) in Gauteng Province, it may be increasing in KwaZulu-Natal, with the most recent survey showing moderate (5%-15%) levels of resistance to the nonnucleoside reverse transcriptase inhibitor drug class.

A qualitative investigation of the views of primary care dentists on participating in prospective studies in the North-West of England

BACKGROUND

There is a poor understanding of to how to recruit and involve primary care dentists in clinical trials.

AIM

To use a qualitative paradigm to explore the views of primary care dentists towards participating in clinical trials and develop an understanding of the factors that facilitate and prevent their involvement. DESIGN, SETTING, SUBJECTS AND METHODS: An iterative approach was undertaken using a focus group (n = 6) followed by phased semi-structured interviews (n = 18). Data were analysed using thematic analysis and constant comparative analysis.

FINDINGS

The semi-structured interviews generated nine codes which were organised into three themes: technical issues for trials in primary dental care, practical issues for research in primary dental care and primary care dentists as research consumers. Overall, primary care dentists had a poor understanding of research methodology and clinical research. Barriers to participation included loss of clinical freedom and control, practice disruption, patient welfare, staff workload, financial loss and time.

CONCLUSIONS

Barriers to primary dental care research need to be overcome through appropriate protocols, funding, training and support. Joint working of primary dental care teams and academic researchers is essential, along with a constructive and open dialogue, if clinical trials are to be successfully undertaken in a practice environment.

A meta-analysis into the effect of lateral-wedged insoles with subtalar strapping versus traditional insoles in adults with medial knee osteoarthritis

To  systematically  identify,  collate,  and  analyze  the  current available evidence  for  the  effectiveness  of  lateral-wedged  insoles,  with subtalar strapping,  on  reducing  pain,  improving  function  and  improving  the femoral-tibial  angle  (FTA),  in  adults  with  medial  knee osteoarthritis compared to traditional insoles without subtalar strapping.Six computerised databases, namely Cochrane Library, CiNAHL, PEDro, BIOMED central,  PubMed  and  ScienceDirect  were  searched. The  included articles were  then  all  rated  using  the  PEDro  scale  to  determine  their meth-odological quality.  Homogeneous data were pooled in a meta-analysis using Review Manager (REVMAN) software.  Where statistical pooling of the results was not possible, findings were summarised in narrative form. Three randomised controlled trials were selected for this review. The average PEDro score was 5.7. A meta-analysis demonstrated that lateral-wedged insoles with subtalar strapping significantly reduced pain in the short-term (p=0.004). The review found that lateral-wedge insoles with subtalar strapping significantly decreased pain in the short-term and seemed to have a positive effect on the FTA in the long-term, when compared to traditional insoles without  subtalar strapping. The lateral-wedge insole with subtalar strapping may provide a financially feasible adjunctive self-management treatment for knee OA and should be considered before invasive procedures such as surgery.

Prediction of response to antiretroviral therapy by human experts and by the EuResist data-driven expert system (the EVE study)

OBJECTIVES

The EuResist expert system is a novel data-driven online system for computing the probability of 8-week success for any given pair of HIV-1 genotype and combination antiretroviral therapy regimen plus optional patient information. The objective of this study was to compare the EuResist system vs. human experts (EVE) for the ability to predict response to treatment.

METHODS

The EuResist system was compared with 10 HIV-1 drug resistance experts for the ability to predict 8-week response to 25 treatment cases derived from the EuResist database validation data set. All current and past patient data were made available to simulate clinical practice. The experts were asked to provide a qualitative and quantitative estimate of the probability of treatment success.

RESULTS

There were 15 treatment successes and 10 treatment failures. In the classification task, the number of mislabelled cases was six for EuResist and 6-13 for the human experts [mean±standard deviation (SD) 9.1±1.9]. The accuracy of EuResist was higher than the average for the experts (0.76 vs. 0.64, respectively). The quantitative estimates computed by EuResist were significantly correlated (Pearson r=0.695, P<0.0001) with the mean quantitative estimates provided by the experts. However, the agreement among experts was only moderate (for the classification task, inter-rater κ=0.355; for the quantitative estimation, mean±SD coefficient of variation=55.9±22.4%).

CONCLUSIONS

With this limited data set, the EuResist engine performed comparably to or better than human experts. The system warrants further investigation as a treatment-decision support tool in clinical practice.