The relevance of oral health for attenders and non-attenders: a qualitative study

BACKGROUND

Low expectations of health mean that oral health becomes a low priority for some people, an appreciation of which would help dentists when a non-attender does come to the surgery.

OBJECTIVE

To provide an insight into why oral health is not important to some people and how this attitude might hinder access to dental care.

METHOD

In this qualitative study, purposive sampling was used to recruit two groups of participants with sociably visible missing, decayed or broken teeth but apparently differing responses to that status. The data analysis used social systems theory as operationalised by grounded theory techniques.

RESULTS

The core category that emerged from the data was that people constructed their own 'margins of the relevance' of oral health. For some people oral health was highly relevant whilst for others it was not very relevant. The degree of relevance of oral health was organised along seven dimensions: the perceived 'normal' state of oral health, the perceived causes of oral health and disease, the degree of trust held in dentistry, perceptions of oral 'health' as a commodity, perceptions of the accessibility of oral health care, perceptions of 'natural' oral health and judgements of character.

CONCLUSIONS

If certain aspects of oral health are not relevant, little that is said about those aspects will be meaningful to people. The key is to either emphasize or gently challenge those ideas and beliefs that allow or hinder the margins of relevance.

A multi-centre prospective case-control study of campylobacter infection in persons aged 5 years and older in Australia

There are an estimated 277,000 cases of campylobacteriosis in Australia each year, most of which are thought to be sporadically acquired. To explore causes for these infections, we conducted a multi-centre case-control study of patients and community controls across five Australian States during 2001-2002. A total of 881 campylobacter cases and 833 controls aged 5 years were recruited into the study. Crude logistic analyses were conducted within various food and non-food exposure groups. A final most parsimonious multivariable logistic regression model was developed and adjusted odds ratios (aOR), 95% confidence intervals (95% CI) were derived together with adjusted population attributable risks (PAR). Consumption of undercooked chicken (aOR 4.7, 95% CI 2.6-8.4) and offal (aOR 2.0, 95% CI 1.0-4.0), ownership of domestic chickens aged<6 months (aOR 12.4, 95% CI 2.6-59.3) and domestic dogs aged<6 months (aOR 2.1, 95% CI 1.1-4.2) were found to be independent risk factors for illness in the final model. The PAR proportions indicate that eating chicken meat, either cooked or undercooked may account for approximately 30% of campylobacter cases that occur each year in Australia. These results justify the continued need for education of consumers and foodhandlers about the risks associated with the handling of raw chicken and the potential for cross-contamination.

Sesame seed products contaminated with Salmonella: three outbreaks associated with tahini

In November 2002, the first of three outbreaks of Salmonella Montevideo infection in Australia and New Zealand was identified in New South Wales, Australia. Affected persons were interviewed, and epidemiologically linked retail outlets inspected. Imported tahini was rapidly identified as the source of infection. The contaminated tahini was recalled and international alerts posted. A second outbreak was identified in Australia in June-July 2003 and another in New Zealand in August 2003. In a total of 68 S. Montevideo infections, 66 cases were contacted. Fifty-four (82%) reported consumption of sesame seed-based foods. Laboratory analyses demonstrated closely related PFGE patterns in the S. Montevideo isolates from human cases and sesame-based foods imported from two countries. On the basis of our investigations sesame-based products were sampled in other jurisdictions and three products in Canada and one in the United Kingdom were positive for Salmonella spp., demonstrating the value of international alerts when food products have a wide distribution and a long shelf life. A review of the controls for Salmonella spp. during the production of sesame-based products is recommended.

Formation and breakage of flocs using dual polymers

The effect of shear on the formation and break-up of flocs generated using cationic, anionic and non-ionic polymers, and dual combinations of these, has been investigated using conventional jar test procedure and by continuous optical monitoring. The breakage of flocs was followed at a high stirring speed, corresponding to average shear rate (G) of approximately 520 s(-1). Most of the breakage occurred within a few seconds of increasing the shear rate. After each breakage, the stirring rate was reduced to the original value of 50 rpm (G approximately 23 s(-1)) to allow the flocs to regrow. For cationic-anionic polymers case, the regrowth of flocs was fully reversible and the breakage factors were smallest indicating highest floc strength. In contrast, flocs formed using non-ionic polymer together with anionic or cationic did not produce as strong flocs. It is found that the sequence of polymer addition is not very significant for floc formation and reformation when the cationic-anionic dual system is used.

The effect of polymeric flocculants on floc strength and filter performance

Polymeric flocculants are widely used throughout the water industry as flocculant aids, they are known to increase floc density and aid settlement in the clarification stage of the water treatment process. In this research, polymeric flocculants were used to improve floc strength prior to filtration on a dissolved air flotation (DAF) plant in an attempt to prevent filter breakthrough. A modified jar test procedure using a PDA (photometric dispersion analyser) optical flocculation monitor was developed in order to evaluate the system floc strength. Filtration trials were carried out on a pilot filter rig situated on a surface water treatment works in Yorkshire. The filter feed originated from the main plant filter channel. Filter performance was assessed by continuous online monitoring of effluent particle counts, turbidity and headloss over the period of the filter run. Results indicated that low doses of polymeric flocculants had a beneficial effect on filtered water quality, as measured by particle counts, turbidity, UV254 absorption and dissolved organic carbon (DOC). Polymeric flocculants also had the effect of extending filter run length. The modified jar test results indicated that the flocculants used improved the floc strength and enhanced reflocculation of the micro flocs present after the flotation process.

A review of floc strength and breakage

The main focus of the paper is to review current understanding of floc structure and strength. This has been done by reviewing current theoretical understanding of floc growth and breakage and an analysis of different techniques used for measuring floc strength. An overview has also been made of the general trends seen in floc strength analysis. The rate of floc formation is a balance between breakage and aggregation with flocs eventually reaching a steady-state size for a given shear rate. The steady-state floc size for a particular shear rate can, therefore, be a good indicator of floc strength. This has resulted in the development of a range of techniques to measure floc size at different applied shear levels using a combination of one or more of the following tools: light scattering and transmission; microscopy; photography; video and image analysis software. Floc strength may be simply quantified using the initial floc size for a given shear rate and the floc strength factor. More complex techniques have used theoretical modelling to determine whether flocs break by large-scale fragmentation or smaller-scale surface erosion effects, although this interpretation is open to debate. Impeller-based mixing, ultrasound and vibrating columns have all been used to provide a uniform, accurate and controllable dissipation of energy onto a floc suspension to determine floc strength. Other more recent techniques have used sensitive micromanipulators to measure the force required to break or compress individual flocs, although these techniques have been limited to the measurement of only a few hundred flocs. General trends emerge showing that smaller flocs tend to have greater strength than larger flocs, whilst the use of polymer seems to give increased strength to only some types of floc. Finally, a comparison of the strength of different types of floc (activated sludge flocs, organic matter flocs, sweep flocs and charge neutralised flocs) has been made highlighting differences in relative floc strength.

Teduglutide (ALX-0600), a dipeptidyl peptidase IV resistant glucagon-like peptide 2 analogue, improves intestinal function in short bowel syndrome patients

BACKGROUND AND AIMS

Glucagon-like peptide 2 (GLP-2) may improve intestinal absorption in short bowel syndrome (SBS) patients with an end jejunostomy. Teduglutide (ALX-0600), a dipeptidyl peptidase IV resistant GLP-2 analogue, prolongs the intestinotrophic properties of GLP-2 in animal models. The safety and effect of teduglutide were investigated in SBS patients with and without a colon in continuity.

METHODS

Teduglutide was given subcutaneously for 21 days once or twice daily to 16 SBS patients in the per protocol investigational group, 10 with end jejunostomy (doses of 0.03 (n = 2), 0.10 (n = 5), or 0.15 (n = 3) mg/kg/day), one with <50% colon in continuity (dose 0.03 mg/kg/day), and five with > or = 50% colon in continuity (dose 0.10 mg/kg/day). Nutrient balance studies, D-xylose tests, and intestinal mucosa biopsies were performed at baseline, on the last three days of treatment, and after three weeks of follow up. Pre-study fasting native GLP-2 levels were determined for the five patients with > or = 50% colon in continuity.

RESULTS

Pooled across groups and compared with baseline, teduglutide increased absolute (+743 (477) g/day; p<0.001) and relative (+22 (16)%; p<0.001) wet weight absorption, urine weight (+555 (485) g/day; p<0.001), and urine sodium excretion (+53 (40) mmol/day; p<0.001). Teduglutide decreased faecal wet weight (-711 (734) g/day; p = 0.001) and faecal energy excretion (-808 (1453) kJ/day (-193 (347) kcal/day); p = 0.040). In SBS patients with end jejunostomy, teduglutide significantly increased villus height (+38 (45)%; p = 0.030), crypt depth (+22 (18)%; p = 0.010), and mitotic index (+115 (108)%; p = 0.010). Crypt depth and mitotic index did not change in colonic biopsies from SBS patients with colon in continuity. The most common side effects were enlargement of the stoma nipple and mild lower leg oedema. The improvements in intestinal absorption and decreases in faecal excretion noted after treatment had reversed after the drug free follow up period. A controlled study with a more robust design is ongoing in order to determine the optimal dosage of teduglutide for SBS patients to achieve the maximal effect and utility of this drug in clinical practice.

CONCLUSION

Teduglutide, at three dose levels for 21 days, was safe and well tolerated, intestinotrophic, and significantly increased intestinal wet weight absorption in SBS patients with an end jejunostomy or a colon in continuity.

The metabolic marker tumour pyruvate kinase type M2 (tumour M2-PK) shows increased expression along the metaplasia-dysplasia-adenocarcinoma sequence in Barrett's oesophagus

BACKGROUND

Proliferating and tumour cells express the glycolytic isoenzyme, pyruvate kinase type M2 (M2-PK). In tumours cells, M2-PK usually exists in dimeric form (tumour M2-PK), causing the accumulation of glycolytic phosphometabolites, which allows cells to invade areas with low oxygen and glucose concentrations.

AIMS

To investigate the expression of tumour M2-PK during the metaplasia-dysplasia-adenocarcinoma sequence of Barrett's oesophagus, and to assess the prognostic usefulness of tumour M2-PK in oesophageal cancer.

MATERIALS/METHODS

One hundred and ninety cases selected from the histopathology archives as follows: 17 reflux oesophagitis, 37 Barrett's oesophagus, 21 high grade dysplasia, 112 adenocarcinomas, and three control tumours. Sections were stained immunohistochemically with antibody to tumour M2-PK.

RESULTS

Tumour M2-PK was expressed in all cases, and increased cytoplasmic expression was seen with progression along the metaplasia-dysplasia-adenocarcinoma sequence. All cases of adenocarcinoma showed 100% staining so that tumour M2-PK was not a useful prognostic marker.

CONCLUSIONS

Tumour M2-PK is not a specific marker of Barrett's adenocarcinoma, but may be important as a marker of transformed and highly proliferating clones during progression along the metaplasia-dysplasia-adenocarcinoma sequence.

A review of 187 gunshot wound admissions to a teaching hospital over a 54-month period: training and service implications

BACKGROUND

Violence involving the use of firearms has increased in the UK over the past decade. This study assesses the implications of such injuries for service provision and training by reviewing the experience at one hospital.

METHODS

Accident and emergency triage data were searched for patients presenting with gunshot wounds over a 54-month period. Case notes were reviewed and patterns of care established. The resources required for clinical management were ascertained, and the financial consequences determined at contemporary full cost.

RESULTS

There were 187 attendances with 247 wounds. Mean age was 21 years (range, 8-63 years). Of the attendances, 69% were out of normal working hours. Of the 187 cases, 97 patients were admitted to one hospital (83 of whom required surgery) and 10 patients were transferred to other hospitals (6 for plastic surgery not available at the Manchester Royal Infirmary and 4 due to lack of beds). Of the 80 patients who were not admitted, 4 died in accident and emergency, the rest were either air gun wounds or relatively simple higher calibre injuries. A wide range of surgical specialties was involved (limb injury, 53; thoraco-abdominal and vascular, 28; head and neck, 5; and orbit, 2), and combinations of injuries transgressed specialty and sub-specialty boundaries. The total cost of patient care was pound 267,000.

CONCLUSIONS

Gunshot wounds present a heavy demand on the clinical and financial resources of the receiving hospital, and surgeons responsible for unselected acute admissions in "general surgery" should be capable of dealing with these indiscriminate injuries. Current training and service trends towards increasing sub-specialisation may mitigate against them achieving or retaining this capability.

Monitoring floc formation and breakage

Monitoring of flocculation processes is of great practical importance and can give very useful information on the action of different coagulants under various conditions. It is shown that a continuous optical monitoring technique provides a convenient means of following the formation, break-up and regrowth of flocs under standard mixing and stirring conditions. Examples of results using this approach are given, with alum and PACl coagulants as well as a cationic polyelectrolyte. PACl products give larger flocs than with alum, but they show about the same relative degree of breakage when the shear rate is increased. With all of these coagulants, floc breakage is not fully reversible; i.e. flocs only re-grow to a limited extent when the shear rate is reduced. This is in marked contrast to the action of a cationic polyelectrolyte, where floc breakage is almost completely reversible. Some possible reasons for these observations are discussed, but, so far, there is no adequate model available.

Temperature effects on flocculation, using different coagulants

Temperature is known to affect flocculation and filter performance. Jar tests have been conducted in the laboratory, using a photometric dispersion analyser (PDA) to assess the effects of temperature on floc formation, breakage and reformation. Alum, ferric sulphate and three polyaluminium chloride (PACI) coagulants have been investigated for temperatures ranging between 6 and 29 degrees C for a suspension of kaolin clay in London tap water. Results confirm that floc formation is slower at lower temperatures for all coagulants. A commercial PACl product, PAX XL 19, produces the largest flocs for all temperatures; and alum the smallest. Increasing the shear rate results in floc breakage in all cases and the flocs never reform to their original size. This effect is most notable for temperatures around 15 degrees C. Breakage, in terms of floc size reduction, is greater for higher temperatures, suggesting a weaker floc. Recovery after increased shear is greater at lower temperatures implying that floc break-up is more reversible for lower temperatures.

Synthesis and biological evaluation of 7,8,9,10-tetrahydroimidazo[1,2-c]pyrido[3,4-e]pyrimdin-5(6H)-ones as functionally selective ligands of the benzodiazepine receptor site on the GABA(A) receptor

Benzodiazepines are allosteric modulators of the GABA(A) receptor. The traditionally prescribed benzodiazepines are nonselective and suffer from numerous side effects. Upon the identification of receptor subtypes, we set out to discover selective agents with the anticipation that these agents would have superior therapeutic potential. Herein, we describe the synthesis and biological evaluation of substituted 7,8,9,10-tetrahydroimidazo[1,2-c]pyrido[3,4-e]pyrimidin-5(6H)-ones and disclose that these compounds exhibit functional selectivity at the benzodiazepine receptor of GABA(A) receptor subtypes. The alpha(2)/alpha(3)-selective partial agonist 42 exhibited potent in vivo activity.

The use of sequential studies in a salmonellosis outbreak linked to continental custard cakes

We investigated an outbreak of 54 cases of Salmonella Typhimurium phage type 9 (STM9) with a specific antibiotic resistance pattern. We used sequential analytic studies: two retrospective cohort studies, a case-control study, and a modified case-control study. An outbreak of salmonellosis due to Salmonella Typhimurium PT9 SSu (resistant to streptomycin and sulphafurazole) was identified. Fifty-four cases had illness onset from November 1998 to March 1999. Notifications commenced following a restaurant birthday party in December 1998. An initial cohort and case control study found no association with consumption of custard cake. However, case follow-up identified another cohort of people who had attended a birthday party in February at which 8/27 people who consumed a continental custard cake were ill compared to 0/10 who did not (P = 0.07). A revised case control study found illness was strongly associated with consumption of a particular continental custard cake (Mantel-Haenszel matched OR infinity, P = 0.00004). This report highlights the epidemiological value of using sequential study types, and persisting with the investigation of apparently sporadic food-borne outbreaks.

Selenium status and associated factors in a British National Diet and Nutrition Survey: young people aged 4-18 y

OBJECTIVE

Assessment of selenium status to provide normative reference values, and investigation of associated socio-demographic factors, in a national sample of British young people aged 4-18 y.

SETTING

National Diet and Nutrition Survey-a nationwide cross-sectional sample of young people aged 4-18 y living in mainland Britain in 1997.

METHODS

Selenium status was measured, mainly in fasting blood samples, by plasma selenium concentration in 1127 participants, by red blood cell (RBC) selenium concentration in 1112, and by whole-blood glutathione peroxidase (GPx) activity in 658.

RESULTS

No evidence of severe selenium deficiency or toxicity was observed. Plasma selenium concentration was directly correlated with RBC selenium concentration, and both were associated directly, although less strongly, with GPx activity. Plasma and RBC selenium concentrations increased significantly with age, with RBC concentrations significantly higher in older girls than boys. Region of domicile exhibited a significant relationship. Associations also occurred with parental occupational social class, selenium concentrations being higher in more socially advantaged children. Black and Indian children had considerably higher concentrations than Caucasian children. Concentrations, especially of plasma selenium, were significantly lower in children either (or both) of whose parents were smokers, although, unexpectedly, there was no evidence that children who themselves smoked had lower levels.

CONCLUSIONS

The observed associations between selenium status indices and age, gender, social class, parental smoking and ethnic group indicate a complex network of biological factors which determine selenium concentrations in blood components, and which thus need to be controlled for when using these indices to assess selenium status in young people.

SPONSORSHIP

The survey was commissioned jointly by the Department of Health and the Ministry of Agriculture, Fisheries and Food, whose responsibility has since been transferred to the Food Standards Agency. Support for the further analysis presented in this paper was provided by the Department of Health.

The interaction of humic substances with cationic polyelectrolytes

The anionic charge carried by aquatic humic substances plays a major part in their interaction with metal ions and other cationic species. Removal of such substances by coagulation and flocculation can be, at least partly, determined by charge neutralisation. In this work, the charge densities of a commercial humic acid and an aquatic humic extract have been investigated by studying their interactions with a series of synthetic cationic polyelectrolytes. These covered a range of charge densities and molecular weights. The techniques used were colloid titration by spectrophotometry and streaming current detection, and flocculation determined by colour removal and by an optical monitoring method. For a given cationic polyelectrolyte, all four methods gave charge densities for humic substances which were in good agreement. However, systematic differences in the apparent humic charge density were found, depending on the charge density of the cationic polyelectrolyte used. With low charge density polyelectrolytes, the apparent anionic charge of the humic substances was found to be low. With higher polyelectrolyte charge densities, the apparent humic substance charge density increases and reaches a limiting value when the polyelectrolyte charge is greater than about 3 meq/g. This indicates a non-stoichiometric interaction between the anionic sites of the humic substances and the cationic charges of the low-charge polyelectrolytes. Optimum flocculation of humics occurred with less cationic charge in the case of low-charge polyelectrolytes than those with higher charge density. However, the degree of removal was considerably better in the latter case. In all cases, the molecular weight of the cationic polyelectrolytes (over a range from about 50,000 to 15 million) appeared to have no effect on the results.