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Biomedical subjects

R G Newcombe

Publications and source records attributed to R G Newcombe.

At least 19 recordsLinked to original sources

Relations between alcohol, violence and victimization in adolescence.

BACKGROUND: Compared to links between alcohol and aggression, links between alcohol and vulnerability are poorly understood. OBJECTIVES: To determine whether there is a significant relationship between vulnerability to physical violence and alcohol consumption in adolescence independent of a relationship between alcohol consumption and violent behaviour. DESIGN, SETTING, PARTICIPANTS: Cross-sectional study of 4187 adolescents aged 11-16 in a stratified sample of 13 English schools. RESULTS: Fighting decreased with age whereas hitting others and being hit increased. Relationships between fighting, hitting others and vulnerability to being hit and frequency of drinking and drunkenness were all highly significant (p<0.0001), and were evident at all ages. The outcome most strongly related to frequency of drunkenness was hitting others (odds ratio (OR) 6.62), followed by being hit (OR 4.01) and fighting (OR 2.10). Alcohol consumption and drunkenness remained significantly and independently associated with vulnerability to being hit after adjusting for violent behaviour as well as age and sex. CONCLUSIONS: These findings indicate an association between alcohol and victimization independent of associations of both with physical aggression. Reducing intoxication may reduce victimisation without necessarily affecting violent behaviour. Violence reduction should focus as much on preventing alcohol misuse among victims or potential victims as among offenders.

Adolescent↗

The effectiveness of dental postgraduate courses--are we doing the right thing?

OBJECTIVE: To evaluate the effectiveness of dental postgraduate one-day courses in radiation protection in Wales. DESIGN: Analysis of dentists' performance pre- and immediately post-course training. SUBJECTS AND METHODS: Two hundred and eighty-five general dental practitioners took part in eight courses. Identical, validated multiple choice questionnaires were completed anonymously at the start and at the end of each course. Fifty (+62.5%) or above was regarded as a satisfactory standard. Two hundred and fifty-three (89%) paired morning-afternoon records were completed and analysed. Data was compared to that of similar courses five years earlier. RESULTS: The mean (SD) pre- and post-course percentage scores were 33.8 (13.5) and 63.6 (14.6). The mean improvement was 29.8 percentage points (SD 11.7). The pre-post correlation was +0.66. At baseline only six (2.4%) of the 253 practitioners achieved the preset standard. After the course, 146 (57.7%) did so, an improvement of 55.3% (95% CI 48.9-61.3%). The final score and score gain were slightly higher in more recent graduates. The increase in proportion attaining the standard following training was 11.9% higher for IRMER than for POPUMET (p <0.001). CONCLUSION: The level of knowledge in radiation protection was very low at baseline. Whilst attending the approved course led to considerable improvement, it did not invariably result in a satisfactory level of knowledge in fundamental radiation physics and regulations. The prescribed standard was achieved by less than 60% of the attendees. The IRMER course was significantly more effective than its POPUMET predecessor.

Education, Dental, Continuing↗

The influence of local politicians on pedestrian safety.

AIM: To determine whether local politicians influence the distribution of traffic calming measures. METHODS: Longitudinal ecological study in two UK cities. Local political constituencies were categorized by representation by members of the cabinet structure as a marker of influence. The density of traffic calming features per political area, adjusted for the historical pattern of road injuries, was compared between cabinet represented and non-represented areas. RESULTS: Traffic calming density was significantly associated with cabinet representation status, adjusted for historical collision risk (risk ratio 2.77, 95% confidence interval 1.37 to 5.61). CONCLUSION: These results support the hypothesis that senior local politicians are effective advocates for enhancing safety in their areas.

Accident Prevention↗

Plasma fibrinogen in ulcerative colitis: the effect of disease activity and nicotine therapy in a randomised controlled trial.

BACKGROUND: Smoking increases plasma fibrinogen and cardiovascular risk whereas transdermal nicotine may not. Fibrinogen is an acute phase protein and may reflect disease activity in ulcerative colitis. AIMS: To examine the effect of topical nicotine on plasma fibrinogen and any relationship between fibrinogen and ulcerative colitis disease activity. PATIENTS: Forty-eight non-smokers with moderately active ulcerative colitis. METHODS: Patients were randomised to 6 mg nicotine enema or placebo for 6 weeks, followed by open nicotine therapy for 4 weeks. Plasma fibrinogen was measured at baseline and after 6 and 10 weeks; at each assessment sigmoidoscopy with a rectal biopsy was performed. RESULTS.: At 6 weeks median plasma fibrinogen was 3.30 g/l on nicotine compared to 3.05 g/l on placebo, P = 0.90 when adjusted for baseline values. There was a correlation between fibrinogen and the UC disease activity index (UCDAI) at weeks 0 and 10, P = 0.036 and 0.033, respectively, and between fibrinogen and sigmoidoscopic grade at each assessment, P = 0.014, 0.021 and 0.034. Changes in fibrinogen did not correlate with changes in disease severity. CONCLUSIONS: There was no significant effect of nicotine enemas, in either direction, on plasma fibrinogen-this was raised in moderately active UC and correlated with the sigmoidoscopic grade of colitis and the UCDAI; however, fibrinogen was not sufficiently sensitive to be of practical clinical value.

Colitis, Ulcerative↗

Clinical relevance of multiple sentinel nodes in patients with breast cancer.

BACKGROUND: Indiscriminate removal of axillary nodes may not be justified as it may potentially worsen the morbidity of the sentinel lymph node biopsy (SNB) procedure. This study examined the factors associated with removal of multiple sentinel lymph nodes and determined whether there was an upper threshold for the number of sentinel nodes that should be removed. METHODS: A total of 803 patients with breast cancer underwent successful SNB using peritumoral injection of (99m)Tc-labelled albumin colloid and Patent Blue V dye. SNB was followed by standard axillary treatment at the same operation in all patients. RESULTS: The mean number of sentinel nodes removed per procedure was 2.2 (range 1-9). Multiple sentinel nodes (mean 2.9, range 2-9) were found in 501 patients (62.4 per cent). The false-negative rate in patients who had one sentinel node harvested was 10 per cent, compared with 1 per cent in patients who had three or more nodes removed (P = 0.010). Factors associated with finding multiple sentinel nodes were age less than 50 years (P = 0.004), low body mass index (P < 0.001), tumour in the outer half of the breast (P = 0.013), sentinel node visualization on lymphoscintigraphy (P < 0.001) and an interval of 12 h or less between radioisotope injection and SNB (P = 0.014). For 99.6 per cent of node-positive tumours, metastasis was detected within the first four sentinel nodes removed. CONCLUSION: The identification of multiple sentinel nodes, when present, reduced the false-negative rate. These data suggested that removal of more than four nodes was unnecessary.

Adult↗

Randomized clinical trial of laparoscopic Nissen fundoplication compared with proton-pump inhibitors for treatment of chronic gastro-oesophageal reflux.

BACKGROUND: Both laparoscopic Nissen fundoplication (LNF) and proton-pump inhibitor (PPI) therapy are established in the treatment of gastro-oesophageal reflux disease (GORD). The aim of this study was to compare these two treatments in a randomized clinical trial. METHODS: Between July 1997 and August 2001, 340 patients with a history of GORD for at least 6 months were investigated by endoscopy, 24-h pH monitoring and manometry. Of these, 217 were randomized, 109 to LNF and 108 to PPI therapy. The two groups were well matched for age, sex, weight and severity of reflux. Twenty-four-hour pH monitoring and manometry were performed 3 months after treatment, and quality of life was assessed in both groups using the Psychological General Well-being Index and the Gastrointestinal Symptom Rating Scale at 3 and 12 months after treatment. RESULTS: At 3 months there was an improvement in lower oesophageal sphincter pressure from 6.3 to 17.2 mmHg in the LNF group but no change in the PPI group (8.1 and 7.9 mmHg before and after treatment respectively) (P < 0.001). The mean DeMeester acid exposure score improved from 42.7 to 8.6 (P < 0.001) in the LNF group and from 36.9 to 17.7 in the PPI group (P < 0.001). The mean gastrointestinal symptom and general well-being scores improved from 31.7 and 95.4 respectively before treatment to 37.0 and 106.2 at 12 months after LNF, compared with changes from 34.3 and 98.5 to 35.0 and 100.4 respectively in the PPI group. The differences in both of these scores were significant between the two groups at 12 months (P = 0.003). CONCLUSION: LNF leads to significantly less acid exposure of the lower oesophagus at 3 months and significantly greater improvements in both gastrointestinal and general well-being after 12 months compared with PPI treatment.

Adult↗

A comparison of a reformulated potassium citrate desensitising toothpaste with the original proprietary product.

OBJECTIVES: The recent tendency for toothpaste manufacturers to combine active ingredients for benefits to a number of oral problems requires that such combinations do not vitiate the action of any one agent. The aim of this study was to compare the desensitising effects of a modified formulation with the established product. MATERIALS AND METHODS: The study was a randomised, double blind, two treatment parallel design comparing an existing potassium citrate toothpaste product (Positive Control) with the same formulation to which triclosan and zinc citrate had been added (Test). A total of 56 subjects with dentine hypersensitivity (DH) completed the 8 week study period. At baseline, days 14 and 56 visual analogue scale scores were recorded by the subjects in response to air evaporative and cold water stimuli. RESULTS: Both groups showed improvements, mostly statistically significant, from baseline to day 14 and through to day 56. Most data favoured the Test paste but differences were, for the most part, not significant. CONCLUSIONS: It is concluded that the addition of known anti-plaque agents to an established potassium salt based desensitising toothpaste did not adversely affect the activity of the product in the treatment of DH.

Anti-Infective Agents, Local↗

Differential splintage for flexor tendon rehabilitation: an experimental study of its effect on finger flexion strength.

We conducted laboratory tests to investigate the possibility of partly de-powering flexor digitorum profundus with a view of reducing flexion force during active flexor tendon rehabilitation. We constructed a splint and applied tapes to the proximal segments of fingers to test the hypothesis that holding three fingers more extended than the other finger would reduce the flexion strength of the more flexed finger. The splint allowed the metacarpophalangeal joint of the more flexed finger to be held in three positions of increasing flexion (15 degrees , 30 degrees , and 45 degrees ) compared to the remaining three fingers. We have called this 'differential splintage'. Healthy volunteers were tested for maximum active flexion strength at the different flexion angles. 'Differential splintage' of up to 45 degrees resulted in mean decreased flexion strength of 28% in the index finger and 35% to 38% in the middle, ring and little fingers. The results suggest that "differential splintage" of a finger after flexor tendon repair may be useful in reducing tension across the repair during a program of active tendon rehabilitation and we feel that it has potential to reduce the incidence of repair rupture before healing is complete.

Adult↗

A study into the plaque-inhibitory activity of experimental toothpaste formulations containing antimicrobial agents.

BACKGROUND/AIMS: The use of specific antimicrobial agents in toothpastes may help reduce plaque and gingivitis. There would also appear to be some value in formulating products that contain combinations of such agents that may potentiate any activity present. The aims of this exploratory and pragmatic study were twofold: (1) Exploratory: to compare the effects on plaque re-growth of two zinc citrate/triclosan formulations, one of which contained bromochlorophene and hence demonstrate any additional beneficial effects produced by the addition of the phenol. (2) Pragmatic: to assess whether both pastes were significantly better than a benchmark control, proprietary fluoride toothpaste at inhibiting plaque formation. METHODS: Following an initial prophylaxis to remove all plaque and calculus, toothpaste slurry rinses were used over a 96 h period by 24 volunteers, while omitting all other oral hygiene procedures. After 24, 48 and 96 h, plaque was measured by plaque area and by plaque index. For comparative purposes, a conventional commercial fluoride toothpaste rinse was also used as a benchmark control in this triple cross-over double-blind study. RESULTS: With one exception, comparisons between the three pastes failed to show any significant differences in plaque accumulation at 96 h whether assessed by plaque index or area. At this time period, significantly more plaque was seen with the zinc citrate paste without bromochlorophene, compared with that of the control paste. CONCLUSIONS: The findings from this study failed to demonstrate a plaque-inhibitory action from the two novel formulations beyond that of a conventional benchmark toothpaste, although overall levels of plaque formed by the volunteers, especially on the control paste were generally lower than in previous studies. Nevertheless, it remains to be determined whether the test formulations could exert a direct anti-inflammatory action against gingivitis by way of the triclosan delivery system. Neither test formulation was subsequently marketed.

Adult↗

Comparative study of enema retention and preference in ulcerative colitis.

BACKGROUND: Therapeutic enemas are often used to treat active colitis but their retention may be limited because of urgency to defecate. Some preparations may be better retained and tolerated than others because of their physical properties. AIM: To compare patient preference and retention of four therapeutic enemas, including a nicotine enema, in patients with ulcerative colitis (UC). METHODS: Twenty four patients with active UC received the four trial enemas-corticosteroid, 5-amino salicylate (5-ASA), and nicotine liquid enemas and a corticosteroid foam, in a randomised order, taking one enema on each of four successive nights. Patients scored them 1 to 4 for ease of administration and retention, degree of abdominal bloating, and for their overall preference. RESULTS: Fifteen patients rated nicotine their overall favourite or second favourite, compared with 14 for corticosteroid foam and 11 for 5-ASA and corticosteroid liquids, but this was not significant (p = 0.302). Overall, there was no significant difference in overnight retention. However, the nicotine enema tended to be less well retained in patients with milder urgency but a higher proportion retained it overnight with more severe urgency (p = 0.031 compared with 5-ASA enema). CONCLUSION: There was no significant difference in patient preference or overall duration of retention for the four enemas.

Adrenal Cortex Hormones↗

Erosive effect of a new sports drink on dental enamel during exercise.

PURPOSE: To compare the potential erosive effect of a prototype carbohydrate-electrolyte drink (PCE) with a neutral control (water) and a commercially available carbohydrate-electrolyte drink (CCE) during exercise. METHODS: : Nineteen healthy adults (male, N = 16; female, N = 3) took part in this single blind, three-way crossover study. Subjects were given each of the three drinks according to a randomization schedule, approximately balanced for first-order carryover effects. At the beginning of each of the three study periods, the volunteers were fitted with an intraoral appliance containing two human enamel blocks. During each study period, volunteers exercised for 75 min.d(-1) (5 repetitions of 15 min of exercise, with 5-min rests between exercise repetitions), 5 d.wk(-1) for 3 wk. Each day, drink aliquots of 200 mL were consumed during a 5-min period before exercise and after every 15-min bout of exercise, followed by a final 400-mL aliquot ingested over a 10-min period: a total of 1400 mL per study day. Dental erosion was measured as tissue loss from the enamel blocks by profilometry at the end of each study period. RESULTS: Water, PCE, and CCE produced 0.138 microm (SD 0.090 microm), 0.138 microm (SD 0.038 microm), and 4.238 microm (SD 3.872 microm) of enamel loss, respectively. A Wilcoxon t statistic showed a significant statistical difference between the PCE and CCE drinks (P < 0.001), whereas no significant difference could be detected between the PCE drink and water (P = 0.740). CONCLUSION: The PCE solution showed minimal erosion compared with the commercially available drink, and was statistically indistinguishable from water under the conditions of this study. Use of CE solutions formulated to minimize erosion during exercise may provide significant dental benefits.

Adult↗

A methodology for testing the erosive potential of sports drinks.

OBJECTIVES: The aim of the study was to develop and test a methodology in situ, which simulated the consumption of sports drinks. A secondary aim was to assess the acceptability of the method to sedentary participants. METHODS: To select the sports drink for the study in situ, five commercially available sports drinks were examined for erosive potential in vitro. The study in situ was a single centre, 2-period, 2-treatment crossover study to compare the erosive effect of a commercially available sports drink (Test), with that of mineral water (Control), over 10 day periods on 10 healthy volunteers. Subjects wore upper removable appliances containing two human enamel specimens from 9 a.m. to 5 p.m. The regimen of intake of the drinks was 350 ml in 10, 5-min rest, 650 ml in 25, 5-min rest, 500 ml in 10 and 5-min rest. Measurements of enamel loss were made on samples after 5 and 10 days by profilometry. RESULTS: The in situ study showed a statistically significant difference in erosive potential between the test and control beverages. No specimen exposed to the control beverage displayed appreciable erosion. Erosion occurred with the test drink, but to a variable degree between subjects. The subjects unanimously found the drinking regimen unpleasant. CONCLUSIONS: The sports drink caused significantly more erosion in situ than water and as seen in other studies, there was marked variation in susceptibility to erosion between subjects. The new drinking regimen was designed to simulate pre, during and post-exercise intake. Although all the sedentary subjects participating in this study reported that they found the volume of fluids consumed over a short period of time excessive it is unlikely that this would prove problematic in the exercise environment.

Adult↗

Effectiveness of preoperative staging in rectal cancer: digital rectal examination, endoluminal ultrasound or magnetic resonance imaging?

In rectal cancer, preoperative staging should identify early tumours suitable for treatment by surgery alone and locally advanced tumours that require therapy to induce tumour regression from the potential resection margin. Currently, local staging can be performed by digital rectal examination (DRE), endoluminal ultrasound (EUS) or magnetic resonance imaging (MRI). Each staging method was compared for clinical benefit and cost-effectiveness. The accuracy of high-resolution MRI, DRE and EUS in identifying favourable, unfavourable and locally advanced rectal carcinomas in 98 patients undergoing total mesorectal excision was compared prospectively against the resection specimen pathological as the gold standard. Agreement between each staging modality with pathology assessment of tumour favourability was calculated with the chance-corrected agreement given as the kappa statistic, based on marginal homogenised data. Differences in effectiveness of the staging modalities were compared with differences in costs of the staging modalities to generate cost effectiveness ratios. Agreement between staging and histologic assessment of tumour favourability was 94% for MRI (kappa=0.81, s.e.=0.05; kappa(W)=0.83), compared with very poor agreements of 65% for DRE (kappa=0.08, s.e.=0.068, kappa(W)=0.16) and 69% for EUS (kappa=0.17, s.e.=0.065, kappa(W)=0.17). The resource benefits resulting from the use of MRI rather than DRE was 67164 UK pounds and 92244 UK pounds when MRI was used rather than EUS. Magnetic resonance imaging dominated both DRE and EUS on cost and clinical effectiveness by selecting appropriate patients for neoadjuvant therapy and justifies its use for local staging of rectal cancer patients.

Adult↗

Predictors of non-sentinel lymph node metastasis in breast cancer patients.

In many patients, the sentinel lymph node (SLN) is the sole site of regional nodal metastasis. This subgroup of patients would not be expected to benefit from completion axillary lymph node dissection (CALND). This study evaluated the factors that may determine the likelihood of additional positive nodes in the axilla in the presence of sentinel node metastasis. A total of 618 breast cancer patients underwent SLN biopsy based on lymphoscintigraphy, intraoperative gamma probe detection, and blue dye mapping using 99mTc-nanocolloid and Patent Blue V injected peritumourally. This was followed by standard axillary node clearance at the same operation. Of the 201 patients with a positive SLN, 105 (52%) patients had no further positive nodes in the axilla, 96 (48%) patients had additional metastasis in non-sentinel lymph nodes (NSLN) upon CALND. In patients with a positive SLN, increasing tumour size and tumour grade significantly increased the frequency of additional positive nodes on univariate analysis. The number of SLNs removed and the number of negative SLNs were significant negative predictors. Increasing tumour burden in the sentinel nodes (determined by the number of positive SLNs) was significantly associated with increasing likelihood of positive NSLNs. Multivariate analysis revealed that the rest of the axilla is more likely to be positive if there are more positive than negative SLNs removed and more likely to be negative otherwise. A group of cases from one centre (Cardiff) were subjected to further detailed analysis. Tumour burden in the positive SLN was assessed by measuring the size of metastasis, percentage replacement of the SLN by tumour and by documenting extracapsular extension (ECE) around the SLN. Of the 64 patients with a positive SLN, 34 (53%) patients had no further positive nodes in the axilla, 30 patients (47%) had additional metastasis in NSLNs upon CALND. Increasing tumour burden in the SLN was associated with additional positive nodes in the axilla. Multivariate analysis revealed that size of the SLN metastasis is the most important predictor of involvement of only the SLN. Overall, in patients with a positive SLN, the difference in the number of positive and negative SLNs removed and size of the metastasis in the SLN, all predicted the frequency of additional positive nodes.

Adult↗

Sentinel lymph node biopsy in male breast cancer patients.

The concept of sentinel node biopsy has been validated for female breast cancer patients whereas, ALND remains the standard of care for male breast cancer patients with similar tumours. We evaluated the results of SLN biopsy in male breast cancer patients with clinically negative axillae. This study included all male breast cancer patients who underwent SLN biopsy between February 1998 and October 2003. All patients had negative axillae on clinical examination. All patients underwent pre-operative lymphoscintigraphy. SLN biopsy was performed using a combination of Patent blue V and 99mTc-radiolabelled colloidal albumin injected peritumourally. Nine patients, 26-79 years of age, were included in the study. Pre-operative lymphoscinitgraphy identified SLNs in all patients. Intraoperatively, SLNs were successfully localised in all patients. The mean number of SLNs encountered was 2.4. Five patients had a positive SLN, four a negative SLN. Five patients (one with a negative SLN, four with a positive SLN) had been elected pre-operatively to undergo ALND regardless of findings on SLN biopsy. ALND confirmed the SLN to be negative in one patient (false-negative rate: 0%) and three of the four patients with positive SLN(s) had additional positive nodes in the axilla. SLN biopsy accurately predicted axillary lymph node status in these five patients. These findings compare favourably with findings reported in the literature regarding SLN biopsy in female breast cancer patients. SLN biopsy accurately staged the axilla in male breast cancer patients and should be considered for axillary staging in male breast cancer patients with clinically negative axillae.

Adult↗