Dissipation of chlorpyrifos from tap, river and brackish waters in glass aquaria

Persistence of Dursban 2E formulation of chlorpyrifos was studied in aerated and unaerated tap, river and brackish water, under laboratory conditions. Adsorption of residues onto a glass surface over 12-24 h was 12%. The half-lives of the residues in aerated and unaerated (data in parenthesis) tap, river and brackish waters were 23 and (403) h, 3.2 and (60) h, and 5.8 and 232 h, respectively. The kinetics of dissipation of residues from aerated and unaerated tap, river and brackish waters suggested a linear relationship for most of the data sets, and could not be ascribed to distinct first- or second-order models.

Effects of simulated space vacuum on bacterial cells

The effect of vacuum on bacterial cells is related to water desorption. Below water vapour pressure the inactivation remains constant, independent of total pressure and exposure time. In subsequent growth, the lag-phase of the survivors is delayed. Combined treatment with vacuum and radiation (X-rays or uv of 254 nm wavelength) results in synergistic effects, whereas vacuum and heat can act antagonistically. The vacuum inactivated cells (indicated as loss of colony-forming ability) are completely damaged. They do not show cellular elongation, phage production or respiration. The cellular membrane becomes permeable by vacuum exposure: biomolecules are released from the cells when re-suspended after vacuum treatment.

Evidence-based laboratory medicine

Evidence-based medicine (EBM) is a method for solving problems concerning the assessment of laboratory testing in patient care. Practising EBM involves the use of the available evidence to make health care decisions. The best way to practice EBM is the development, validation and implementation of guidelines. Guidelines are considered as the process by which healthcare research and experience are translated into improved patient care. In laboratory diagnostics EBM can be best demonstrated in high-prevalence conditions. Because of the number of patients encountered, high-prevalence conditions have a greater impact on patient morbidity and health care expenditure. In evidence-based laboratory medicine the best evidence comes from systematic reviewing studies of diagnostic tests. The reviewing of diagnostic trials and the development of good practice guidelines on the basis of these studies must be an important task of the scientific associations of clinical chemistry and laboratory medicine.

Effect of space factors on Escherichia coli B/r cells

Stationary phase cells of Escherichia coli B/r were inactivated when they were exposed to high vacuum (10(-6) torr). About 5% of the cells were still able to form a colony after 45 min exposure. Vacuum dried cells (0.5 torr, 120 min) show colony forming ability of 30% or more. They were inactivated to about 5% by further vacuum treatment. Vacuum treated cells showed higher permeability for various cell components. UV irradiated E. coli B/r cells in vacuum showed increased UV sensitivity. DNA-protein cross-links were preferentially formed in a vacuum. To obtain 63% of DNA cross linked with protein required 852 erg mm-2 (D37) of UV irradiation in suspension and only 72 erg mm-2 of UV irradiation in vacuum. The protein components of DNA-protein cross-links were hydrolysed with pronase E and the amino acids directly bonding to DNA were determined. The most important amino acids concerned in DNA-protein cross-links seem to be glycine and alanine, followed by aspartic acid (asparagine), glutamic acid (glutamine) and histidine. The sensitivity to X-rays of stationary phase E. coli B/r cells seems to depend on the remaining gas atmospheric in the vacuum since it varies with different pumping systems.

Informal carers in cancer contexts

This paper considers some of the challenges involved in studying informal carers in cancer contexts. It reviews current knowledge by examining, first, the dominant psycho-oncological research tradition that focuses on psychological distress among carers and, second, the more recent sociologically informed body of work examining what carers actually do and the contribution that they make to patient care. The authors suggest that this second sociologically informed approach offers an important counter-weight to the psycho-oncological perspective. The developing research agenda for a sociology of cancer caring is briefly outlined.

The need to know: informal carers and information1

There is a growing recognition that the carers of cancer patients require information. A key source of this information is the formal health care system that patients, and thus carers, encounter. However, the research literature suggests a lack of clarity on the part of service providers concerning the type, amount, timing and purpose of information for carers. This lack of clarity is reflected in the ways carers have been 'tacked on' to patients and thus are often treated as co-clients. That carers are also an active participants in the illness scenario is not always fully recognized, resulting in failure to provide appropriate information. Carers' interactions with health service providers are complex and context bound, and entail potential tensions of allegiance in the arena of information exchange. This article suggests that the following research and practice is required: a clearer understanding of the informational needs of carers in variable situations, specific ways to address these needs, where carers 'fit in' to the health care system, and how processes of information exchange with carers can be improved.

Cancer and faith. Having faith--does it make a difference among patients and their informal carers?

This research considers the impact of having a religious faith on the cancer experience of patients and informal carers, focusing primarily on the association between faith and psychosocial needs. A questionnaire survey of 1000 patients in the north-west of England returned 402 completed questionnaires; around two-thirds of patients indicated they had an informal carer. Using logistic regression analysis, we examine the relationship between the importance of 48 needs and faith for 189 paired patients and carers, while controlling for the effect of eight socio-demographic and clinical variables. Patients with expressed faith identified fewer psychosocial needs than those without faith. In contrast, carers with expressed faith identified more needs than those without faith in relation to support from family and neighbours. Carers also needed more help with finding a sense of purpose and meaning, and help in dealing with unpredictability. Not surprisingly, both patients and carers with faith identified a greater need for opportunities for personal prayer, support from people of their own faith and support from a spiritual adviser. Various explanations of these differences between patients and carers are proposed. The crucial point is that one should not too readily assume that the cancer experience is shared in the same way by patients and carers. In understanding the faith dimension, one needs to consider both the spiritual and secular aspects of having a religious faith.

Effects of vaginal distension on urethral anatomy and function

OBJECTIVE

To determine the effect of repeated and prolonged vaginal distension on the leak-point pressure (LPP) and urethral anatomy in the female rat, as prolonged vaginal distension has been clinically correlated with signs of stress urinary incontinence (SUI).

MATERIALS AND METHODS

Sixty female rats were placed into one of five groups; four groups underwent one of four vaginal distension protocols using a modified 10 F Foley catheter, i.e. prolonged (1 h), brief (0.5 h), intermittent (cycling inflated/deflated for 0.5 h) or sham distension. All animals had a suprapubic bladder catheter implanted 2 days after and were assessed urodynamically 4 days after vaginal distension. The fifth group of rats acted as controls and did not undergo vaginal distension, but did have a suprapubic bladder catheter placed and urodynamics assessed. To measure LPP the rats were anaesthetized with urethane, placed supine and the bladder filled with saline (5 mL/h) while bladder pressure was measured via the bladder catheter. LPPs were measured three times in each animal by manually increasing the abdominal pressure until leakage at the urethral meatus, when the external abdominal pressure was rapidly released. Peak bladder pressure was taken as the LPP and a mean value calculated for each animal. Immediately after measuring LPP the urethra was removed and processed routinely for histology (5 micro m sections, stained with haematoxylin/eosin and trichrome). The means (sem) were compared using a Kruskal-Wallis one-way anova on ranks, followed by a Dunn's test, with P < 0.05 indicating a significant difference.

RESULTS

Both LPP and the external increase in abdominal pressure were significantly lower after prolonged distension, at 31.4 (1.7) and 19.8 (1.2) cmH2O, than in the sham group, at 41.1 (3.2) and 32.0 (4.7) cmH2O, respectively. There were no significant differences in LPP or in the increase in abdominal pressure between the brief, intermittent and sham groups. Qualitative histology showed that prolonged distension resulted in extensive disruption and marked thinning of urethral skeletal muscle fibres. Brief and intermittent distension showed mild and focal disruptions, respectively.

CONCLUSIONS

As observed clinically, prolonged vaginal distension results in a lower LPP, greater anatomical injury and increased severity of SUI. These results suggest that ischaemia is important in the development of SUI after prolonged vaginal distension.

Culturability, injury and morphological dynamics of thermophilic Campylobacter spp. within a laboratory-based aquatic model system

AIMS

To study the survival processes of thermophilic Campylobacter spp. within a modelled aquatic system and particularly the involvement and survival potential of viable but non-culturable forms.

METHODS AND RESULTS

The survival and morphological characteristics of populations of thermophilic Campylobacter species exposed to simulated aquatic conditions were examined using a combination of cultural and microscopic techniques. Populations underwent progressive decay when exposed to simulated aquatic conditions. The rates of population decay were observed to be significantly greater at the higher temperature (20 degrees C) with a rapid transition of the dominant sub-populations from non-stressed to dead cells occurred within 3 days. At 10 degrees C the rate of culturability loss was much reduced with substantial development (approx. 80% of total population) of viable but non-culturable (VBNC) populations by all species within 3 days, declining to represent approximately 5-25% of the total population at day 60. Significant differences (P < 0.001) were identified between decay rates as a consequence of different species, sub-populations and temperature but not between sub-populations of different species. Morphological variants including spiral, elongated spirals and rods, short rods and coccoid forms were identified. The endpoints of morphological transition were temperature-independent and isolate-specific yet the rate of morphological transition was directly related to temperature and approximately equivalent between species.

CONCLUSION

The VBNC state is a transitory stage in the degeneration of Campylobacter population within the aquatic environments simulated during this study.

SIGNIFICANCE AND IMPACT OF THE STUDY

VBNC cells form the most persistent, viable, potentially pathogenic sub-population of Campylobacter populations exposed to aquatic stress conditions.

H RAS mutations in haematologically normal individuals

INTRODUCTION

Point mutations in N, K and H RAS have been found in adverse haematological malignancies. The background frequency of RAS mutations in the normal population has yet to be determined. Here we report the results of a screen for RAS mutations from normal individuals.

MATERIALS AND METHODS

DNA from peripheral blood or bone marrow from 115 haematologically normal individuals was screened for point mutations in N, K and H RAS, at amino acid positions 12, 13 and 61. The screening was done using polymerase chain reaction and oligonucleotide hybridisation and candidate mutations were subsequently confirmed by cloning and sequencing.

RESULTS AND CONCLUSION

Point mutations were identified in DNA from two of the 115 individuals. Both mutations resulted in an amino acid substitution at position 12 in H RAS. Both individuals with detectable H RAS mutations remain haematologically normal.

[Computer-assisted development of epitheses after optical recording of facial defects]

A major drawback of conventional impression techniques used for customizing facial prostheses is the fact that pressure applied deforms soft tissue, thus reducing accuracy and causing patient discomfort. A possible solution is the use of optical 3-D coordinate measuring techniques, such as the fringe projection technique, which enables precise and contact-free recording of facial surfaces. The application of this method is demonstrated on a patient who lost his left eye and part of the jaw bone during surgery for cancer. 3-D CAD software that supports the construction of a facial prosthesis from the data obtained has been developed. For this purpose, spline functions are used to define border curves, and the intact half of the face is used as a model for the prosthetic surface. The resulting digital data are used to construct first a model made of synthetic resin, and then a final wax model with the aid of rapid prototyping techniques.

In vivo and in vitro modulation of HLA-DM and HLA-DO is induced by B lymphocyte activation

Ag presentation via HLA class II molecules in B lymphocytes depends on the coordinated action of HLA-DM, the catalyst of class II-peptide loading, and HLA-DO, a pH-dependent modulator of DM, the expression of which is almost completely restricted to B lymphocytes. The relative expression levels of both class II modulators are critical for the composition of the HLA class II peptide repertoire. The data in this work demonstrate that DO and DM expression are both dependent on the cellular activation status in primary human B lymphocytes. In vivo low-density activated primary human B lymphocytes show a prominent reduction in DO and DM expression when compared with high-density resting primary B lymphocytes. In vitro, reduction of DO and DM expression can be induced by B lymphocyte activation via the B cell receptor or by use of the phorbol ester, PMA. Specific inhibition of protein kinase C resulted in a significant reduction of HLA-DO and is potentially due to protein degradation in lysosomal compartments as the phenomenon is reversed by chloroquine. Thus, the expression of the dedicated HLA class II chaperone DM and its pH-dependent modulator DO is regulated and tightly controlled by the activation status of the B lymphocyte.

The psychosocial needs of cancer patients: findings from an observational study

The objectives of this study were to identify the prevalence of psychosocial need, and the contributory factors to need, among cancer patients, using a descriptive cross-sectional questionnaire survey of adult cancer patients. The participants were 1,000 patients from four hospitals in the north west of England with the following characteristics: tumour type (breast, colorectal, lymphoma, lung), being 1 month from a 'critical moment' in the cancer journey (i.e. (i) diagnosis, (ii) end of first treatment, (iii) recurrence, (iv) move from active treatment to palliative care), and aged over 18 years. The main outcome measure was a psychosocial needs inventory comprising seven needs categories (48 need items). A sample of 402 was achieved (40% response rate). Psychosocial needs relating to the need categories 'health professionals', 'information' and 'support networks' are commonly expressed and strongly felt by cancer patients. Needs relating to 'identity', 'emotional and spiritual' issues and 'practical' issues are less commonly expressed but are also strongly felt. Particular needs are related to tumour type, illness 'critical moment', age, gender, health status, socioeconomic and other social factors. This information should increase awareness among cancer care professionals about a range of psychosocial needs and may help them target particular patient groups for particular support interventions.

Insertional mutagenesis of genes required for seed development in Arabidopsis thaliana

The purpose of this project was to identify large numbers of Arabidopsis genes with essential functions during seed development. More than 120,000 T-DNA insertion lines were generated following Agrobacterium-mediated transformation. Transgenic plants were screened for defective seeds and putative mutants were subjected to detailed analysis in subsequent generations. Plasmid rescue and TAIL-PCR were used to recover plant sequences flanking insertion sites in tagged mutants. More than 4200 mutants with a wide range of seed phenotypes were identified. Over 1700 of these mutants were analyzed in detail. The 350 tagged embryo-defective (emb) mutants identified to date represent a significant advance toward saturation mutagenesis of EMB genes in Arabidopsis. Plant sequences adjacent to T-DNA borders in mutants with confirmed insertion sites were used to map genome locations and establish tentative identities for 167 EMB genes with diverse biological functions. The frequency of duplicate mutant alleles recovered is consistent with a relatively small number of essential (EMB) genes with nonredundant functions during seed development. Other functions critical to seed development in Arabidopsis may be protected from deleterious mutations by extensive genome duplications.

Informal carers of cancer patients: what are their unmet psychosocial needs?

This paper considers the significant unmet psychosocial needs of the informal carers of cancer patients, drawing on data generated in a 3-year UK study (1997-2000) on the psychosocial needs of cancer patients and their main carers. While the needs of the carers of cancer patients are increasingly being recognised in healthcare policy documents, there is relatively little published literature on these needs. A "significant unmet need" is defined here as a need deemed important by the carer, but which has not been met. A descriptive cross-sectional survey of carers was conducted and the responses of 195 carers relating to 48 psychosocial need items were analysed. A subset of these carers (n = 32) were interviewed. Forty-three per cent of carers had significant unmet needs. They were more likely to be those where the relationship to the patient was not that of a partner or spouse, more likely to have other caring responsibilities, and less likely to have friends or relations to call upon for help. Carers with unmet needs were also more likely to be in poor health themselves or to be caring for a patient who had reached the palliation-only phase in their cancer journey. The majority of carers expressed the importance of needs such as having good relationships with healthcare professionals and receiving honest information, but few expressed dissatisfaction with these aspects of need. Items of significant unmet need clustered around aspects of managing daily life, emotions, and also social identity for a sizeable minority of carers. These are the same areas of significant unmet need that concern patients. However, carers have more of these concerns, reflecting their comparative neglect. The paper also considers how these widespread concerns can be addressed.

The significant unmet needs of cancer patients: probing psychosocial concerns

'Significant unmet needs' are those needs that patients identify as both important and unsatisfied. In this article we ask whether the overall needs of cancer patients are actually being met. We believe that the range of unmet need, and the kinds of patients who are more likely to claim unmet need, should be carefully identified. The needs responses of a series of 295 cancer patients in a cross-sectional survey were analysed. The majority expressed the opinion that information and good relationships with health care professionals were important, and few expressed dissatisfaction with these aspects of need. Similarly, needs items about support from family and friends were largely rated as important and satisfied. For a sizeable minority of patients, items of significant unmet need cluster around aspects of managing daily life, emotions, and social identity. The distribution of significant unmet needs is not random but is more likely to be experienced by patients who are younger, have a long-standing illness or disability, do not own/have use of a car, and/or have no religious faith. Furthermore, significant unmet needs relate to patients' ability to talk freely to a carer about the cancer, the degree to which the cancer interferes with social activities, and whether financial difficulties are experienced. Most of the significant unmet need is beyond the remit of services primarily designed for the treatment of disease. We consider whether multidisciplinary cancer teams can be expected to deal with all aspects of the cancer experience.

A study of occlusal variation in the primary dentition of Australian twins and singletons

In this study, we quantified the extent of variation in different occlusal features of Australian children of European descent with complete primary dentitions, but no permanent teeth present in the mouth. The study group consisted of 412 individuals, aged between 3 and 7 years, including 70 monozygous (MZ) twin pairs, 68 same-sexed dizygous (DZ) twin pairs, 11 opposite-sexed DZ twin pairs, and 114 singletons. Occlusal traits, including inter-dental spacing, incisal overbite and overjet, arch breadth and arch depth, were obtained directly from dental casts or indirectly from photocopies or impressions of the casts. Descriptive statistics summarised the data and indicated that distributions were similar to those published for other populations. Univariate genetic analysis, using the structural equation modelling package Mx, was carried out on the quantitative data using the normal assumptions of the twin model. Genetic modelling indicated that a model incorporating additive genetic (A) and unique environmental variation (E) was the most parsimonious for interdental spacing, overbite, overjet and arch dimensions. Estimates of heritability for interdental spacing ranged from 0.62 to 0.81. Estimates for overbite and overjet were 0.53 and 0.28, respectively, and estimates for arch dimensions ranged from 0.69 to 0.89. These results indicated a moderate to relatively high genetic contribution to observed variation.