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Notes: Objective To analyse biopsies of large loop excision of the transformation zone of the cervix; to identify factors associated with negative histology; and to develop predictive models in order to reduce the number of negative loop excisions.Design Retrospective analysis of patient notes and audit database.Setting Colposcopy clinic of a large district general hospital in North Staffordshire.Population Four hundred and fifty-two women who underwent a large loop excision of the transformation zone (LLETZ) procedure for suspected cervical intraepithelial neoplasia.Methods Women who underwent a LLETZ procedure were placed in two different groups, one positive for cervical intra epithelial neoplasia and the other negative for cervical intra epithelial neoplasia. Information was obtained on a number of clinical and colposcopic variables. Analysis was undertaken to determine if there were any differences between the two groups. These factors were then identified and three predictive models generated. Receiver-operator characteristic curves were used to assess and test these models.Main outcomes measures To identify factors associated with negative histology on a LLETZ specimen. To predict how to reduce the number of negative LLETZ specimens.Results Four hundred and fifty-two women underwent a LLETZ procedure, 88 were negative (19%) and 364 were positive (81%). In women who were treated at their first visit, 56/316 (18%) had negative histology. There were significant associations between negative histology in the LLETZ and negative or low grade cytological atypia, negative colposcopic findings and years of age 〉 50 in both bivariate analysis and stepwise logistic regression. In the predictive models, the sensitivity ranged between 72% and 80%, the specificity 59%–72%, and the area under the receiver-operator characteristic was 0.75–0.77. If we had used the predictor models and managed women with negative or low grade cervical atypia and negative colposcopy findings conservatively, we would have reduced the negative biopsy rate from 19% to 14%, but five cases of high grade disease and 25 cases of low grade disease would have been missed. If we had also included women aged 〉 50 years in this model, the negative biopsy rate would have dropped from 19% to 15%, with only one case of high grade disease and 11 cases of low grade disease missed. All these women would require continued cytological and colposcopic surveillance. Importantly, no cases of invasion would have been missed.Conclusion Using a predictive model can reduce the number of negative LLETZ specimens, but at the expense of continued cytological and colposcopic surveillance and cannot be recommended in normal practice. This raises the question whether current standards for negative histology in LLETZ specimens are set unrealistically high.

Notes: Objective To test the hypothesis that prilocaine with felypressin causes fewer side effects than lignocaine with adrenaline when performing large loop excision of the transformation zone of the cervix.Design Randomised trial.Setting Colposcopy clinic in a large district general hospital.Participants Two hundred consecutive women undergoing large loop excision of the transformation zone of the cervix.Methods Two different local anaesthetic combinations (prilocaine with felypressin and lignocaine with adrenaline) were compared in women undergoing large loop excision of the transformation zone. Prospective collection of clinical and treatment data was undertaken with scoring using an ordinal scale of pain experienced by the women during the procedure. Peri-operative blood loss and any side effects were also recorded.Main outcome measures Side effects associated with the local anaesthetic agents.Results Lignocaine with adrenaline resulted in less blood loss (P= 0.006) but was more likely to cause side effects, such as feeling faint (P= 0.017) and shaking (P 〈 0.001).Conclusion Prilocaine with felypressin causes fewer side effects than lignocaine with adrenaline and is therefore the preferred local anaesthetic combination for large loop excision of the transformation zone.

Notes: The Mersey Estuary has suffered a legacy of abuse and neglect since the beginning of the Industrial Revolution. The discharge of effluents from manufacturing processes, together with wastewater from the burgeoning centres of population, resulted in the estuary gaining the unenviable reputation of being one of the most polluted rivers in Europe.As a result of the long-awaited remedial action which has been implemented over the last fifteen years, there is now unequivocal evidence that the water quality of the river and the biology of the system have improved significantly and will continue to do so as further planned alleviation schemes are completed.This paper reviews the achievements which have been made at the half-way stage in the 25-year multi-billion pound ‘clean-up’campaign.

Notes: Susceptibility and outcome in complex disorders such as asthma and cancer appear to be determined, at least in part, by genetic polymorphism. However, while our ability to identify new allelic variants and study them in case and control populations has greatly improved, considerable difficulties remain in elucidating how many genes determine particular clinical phenotypes. This is because most studies have concentrated on study of single genes in relatively small study groups. The important issues of gene–gene interactions (epistasis) and high-risk subgroups have not yet been adequately addressed. We now describe a general approach, using patients with head and neck cancers as an example. Our purpose is to demonstrate candidate gene selection, statistical approaches, and identification of patient subgroups.

Notes: This study measured the temperature in and around mandibular fractures in 20 anaesthetized patients. A fine calibrated thermocouple attached to a digital thermometer was used to measure temperature at the bone surface margin of a mandibular fracture and 5 and 10 mm from the fracture; within the fracture against the bone at 5, 7 and 10 mm depths and at the base of 7 mm deep biopsy cavities 5 and 10 mm distant from the fracture line immediately after biopsy, then 1 and 2 min later. On the surface the temperature was approximately 1 °C warmer than at the 5 and 10 mm sites distant from the fracture. Temperature reduced at the 1 and 2 min readings after the biopsy cavity cutting. This study confirmed that the surface temperature is lower than internal bone temperatures.

Notes: Lethal disease (LD) is a lethal yellowing-type disease of coconuts associated with phytoplasmas in Tanzania, but the insect vector for it has not yet been identified. In this study, the auchenorrynchous insects in LD-infected coconut fields were surveyed to determine potential vectors for the disease. No significant correlation was found between disease incidence and numbers of insects collected from the field, possibly reflecting the unknown incubation period for the disease. However, analysis of more than 5000 individual insects by the polymerase chain reaction (PCR), using LD-specific primers derived from the phytoplasma 16S rRNA gene, revealed PCR products of the correct size from eight individuals of Diastrombus mkurangai and four of Meenoplus spp. When digested with restriction endonucleases, fragments of the same size as the LD phytoplasma were obtained. No PCR products were detected in any of the other insect species tested. These results implicate D. mkurangai and Meenoplus spp. as probable vectors of the LD phytoplasma.

Notes: Abstract: Lifetime measurements of states in nuclei with A=187 and 188 have been performed, using reactions between 155Gd and 36Ar and following the transport of evaporation residues to the focal plane of a gas-filled recoil separator. In a separate experiment using the 159Tb(32S, 4n) reaction the γ-decay of isomeric levels in 187Tl has been studied using delayed γ-γ coincidence measurements. From observation of their subsequent γ decay, the mean lifetimes were measured to be 1000 ± 55 ns and 1600 ± 100 ns. Although it was not possible to characterize the isomers completely, they are proposed as candidates for one-proton, two-neutron excitations. In the course of this study, the decay of an isomer in 188Pb was also observed and its lifetime was measured as 1150 ± 30 ns, and limits of 20–600 ns were placed on the meanlife of an isomer conjectured in 187Pb.

Notes: For a variety of reasons, the relative impacts of neural-net inputs on the output of a network’s computation is valuable information to obtain. In particular, it is desirable to identify the significant features, or inputs, of a data-defined problem before the data is sufficiently preprocessed to enable high performance neural-net training. We have defined and tested a technique for assessing such input impacts, which will be compared with a method described in a paper published earlier in this journal. The new approach, known as the ‘clamping’ technique, offers efficient impact assessment of the input features of the problem. Results of the clamping technique prove to be robust under a variety of different network configurations. Differences in architecture, training parameter values and subsets of the data all deliver much the same impact rankings, which supports the notion that the technique ranks an inherent property of the available data rather than a property of any particular feedforward neural network. The success, stability and efficiency of the clamping technique are shown to hold for a number of different real-world problems. In addition, we subject the previously published technique, which we will call the ‘weight product’ technique, to the same tests in order to provide directly comparable information.