VIDAS Enzyme-Linked Fluorescent Immunoassay for Detection of Salmonella in Foods: Collaborative Study

The VIDAS SLM method for detection of Salmonella was compared with the Bacteriological Analytical Manual (BAM)/AOAC culture method in a collaborative study. Twenty laboratories participated in the evaluation. Each laboratory tested one or more of 6 test products: milk chocolate, nonfat dry milk, dried whole egg, soy flour, ground black pepper, and ground raw turkey. No significant differences (P< 0.05) were observed between the 2 methods. The 2 methods were in agreement for 99% of 1544 samples analyzed. Of the 20 samples out of agreement, 8 were VIDAS SLM positive and BAM/AOAC negative, and 12 were VIDAS SLM negative and BAM/AOAC positive. The VIDAS SLM method for detection of Salmonella in foods has been adopted first action by AOAC INTERNATIONAL.

An elevated temperature study of a Ti adhesion layer on polyimide

Titanium layers are used to promote adhesion between polymer substrates for flexible electronics and the Cu or Au conducting lines. Good adhesion of conducting lines in flexible circuits is critical in improving circuit performance and increasingcircuit lifetime. Nominally 50 nm thick Ti films on polyimide (PI) are investigated by fragmentation testing under uniaxial tensile load in the as-deposited state, at 350 °C, and after annealing. The cracking and buckling of the films show clear differences between the as-deposited and the thermally treated samples, cracks are much straighter and buckles are smaller following heat treatment. These changes are correlated to a drop in adhesion of the samples following heat treatment. Adhesion values are determined from the buckle dimensions using a total energy approach as described in the work of Cordill et al. (Acta Mater. 2010). Cross-sectional transmission electron microscopy of the Ti/PI interface found evidence of a ~ 5 nm thick interlayer between the largely columnar Ti and the amorphous PI. This interlayer is amorphous in the as-deposited state but nano-crystalline in those coatings tested at elevated temperature or annealed. It is put forward that this alteration of the interfacial structure causes the reduced adhesion.

Access to primary dental care for patients with inherited bleeding disorders

Patients with inherited bleeding disorders (IBD) can face difficulty in accessing primary dental care either due to disease-specific or patient-related barriers. This can lead to poor oral health and increase the need for more invasive dental treatment. This study aimed to highlight actual and perceived barriers that IBD patients from the East London area were experiencing. It also gives an overview of the experience history of the General Dental Practitioners (GDPs) treating these patients. Information was gathered via pre-designed surveys as part of a service development audit. A total of 105 anonymous patient surveys and 50 GDP surveys were completed between December 2010 and July 2011. The patient survey highlighted more patients to be affected by patient-related than disease-specific barriers to access dental care. The GDP survey identified that just under half of GDPs questioned were not confident in the dental management of patients with bleeding disorders. Identifying misconceptions and barriers to access primary dental care will enable further development of our shared-care approach between General Dental Services, Hospital or Community Dental Services and Haemophilia Centre, optimizing regular preventative advice and follow ups to prevent dental disease and invasive dental treatment requiring haemostatic treatment.

Leptin: of mice and men?

A major advance in the understanding of the control of appetite, food intake, and energy expenditure came with the discovery of leptin. Leptin concentrations correlate with adipose tissue mass, and leptin acts via the central nervous system (CNS) to reduce food intake and increase energy expenditure. A variety of different neurotransmitters have been implicated in mediating the CNS effects of leptin. In humans, leptin deficiency is unlikely to be a major cause of obesity. Most humans are not leptin deficient, but have a leptin concentration raised in proportion to their fat mass. A recent clinical trial looking at the use of recombinant leptin in treating human obesity has resulted in only variable amounts of weight loss. The role of leptin extends beyond the control of food intake and energy expenditure. Leptin reverses many of the physiological responses to starvation. It is suggested that the main role of leptin might be in response to food deprivation and not in obesity.

Comparison of human telomerase reverse transcriptase messenger RNA and telomerase activity as urine markers for diagnosis of bladder carcinoma

BACKGROUND

Human telomerase reverse transcriptase (hTERT) has been identified as the catalytic subunit of telomerase ribonucleoprotein complex known to be required for cellular immortality and oncogenesis. Although human telomerase activity (hTA) is considered as a general marker for malignancy based on its presence in most malignant tumors including bladder cancer, its detection in urine is affected by many factors. The objective of this study was to compare the clinical utility of detecting urine hTERT messenger RNA (mRNA) by multiplex hTERT/GAPDH RT-PCR and urine hTA by telomerase repeat amplification protocol (TRAP) in the diagnosis of bladder cancer.

METHODS AND RESULTS

Cystoscopy urine samples or bladder washes prospectively collected from 35 patients with confirmed (35) or clinically suspected (5) transitional cell carcinoma (TCC) of the bladder were examined by TRAP, hTERT/GAPDH RT-PCR, and urine cytology. The control group comprised 21 healthy volunteers and 3 patients without TCC. The hTERT/GAPDH RT-PCR test showed significantly higher diagnostic sensitivity than TRAP assay (94.3% vs 48.6%, P <.001) and urine cytology (95.2% vs 61.9%, P =.008) for confirmed TCCs. In particular, for superficial TCCs low grade (I-II), the hTERT/GAPDH RT-PCR test outperformed TRAP (90% vs 25%, P <.001) and urine cytology (91.7% vs 58.3%, P =.46). The overall specificity of the hTERT/GAPDH RT-PCR, TRAP and urine cytology was 92% (22/24), 100% (24/24), and 100% (3/3), respectively. A positive hTERT mRNA expression was also detected in urologic specimens from 3 patients with previous history of TCC, 3 to 6 months before cystoscopic evidence of cancer.

CONCLUSION

In this pilot study, the hTERT mRNA expression in urine sediments is a more sensitive marker for diagnosis of TCC of the bladder than hTA and cytology. However, there is a higher false-positive rate.

Experienced nurses learning with medical students: a case study

Although there are successful examples of interdisciplinary education this generally relates to pre-registration health-care professionals. Post-registration projects are usually confined to skills workshops or social science subjects, which rarely include medical staff. This project was unusual in its attempt to combine the needs of experienced practitioners with those of medical students. There are practical issues for this form of learning such as, the organization of modules into 'systems' when health-care professionals (as part of a parallel project) indicated their interests lay in courses that related to clinical practice organized around disease processes/conditions. This case study demonstrates that concerns related to the potential mismatch of clinical expertise, maturity and scientific background are not insurmountable problems, and that clear benefits can be gained. It could be argued that until pre- and post-graduate medical staff are integrated with other disciplines, the real benefits of shared understanding, enhanced team work and mutual respect will remain illusive. It is not anticipated that this form of learning would be suitable for the majority of practitioners, whose core needs are generally met by existing opportunities. However, there is a need for a greater depth of academic understanding particularly for those in senior positions or in specific specialized areas (also identified in the parallel study) and for those whose roles are expanding. These practitioners are more likely to have the ability to apply their new knowledge to clinical practice, using reflective techniques with minimal facilitation to enhance their established clinical expertise. For them this model of learning offers the opportunity to tailor education to the individual needs of the practitioner without the costly establishment of complete new programmes of learning. This case study proved particularly successful for the participants as they enhanced understanding and confidence in the knowledge underpinning their practice. This enabled them to better anticipate patients needs, to identify complications and initiate action at an earlier stage. Their appreciation of rationale underpinning medical treatment has enabled them to support junior medical staff, and to promote the continuity of appropriate care. They are more active in the education of patients, relatives and staff, and have identified specific developments which will be informed by the knowledge they have gained. It also proved beneficial to junior medical staff with whom interdisciplinary working has improved. Each organization involved in facilitating the initiative also benefited by gaining mutual understanding and appreciation of systems, constraints and opportunities. Equally, relationships among them have been strengthened and key issues with practical solutions have been identified to inform future joint ventures. Indications suggest that there would be value in using this case study to inform a structured pilot project involving other modules of learning and potentially other disciplines. If successful it could benefit all health-care professionals, particularly those senior staff who are expanding their roles and have educational needs unmet by existing provision. In addition to providing complementary opportunities this format provides a mechanism to enhance the mutual understanding essential to effective teamwork.

An encyclopedia of mouse genes

The laboratory mouse is the premier model system for studies of mammalian development due to the powerful classical genetic analysis possible (see also the Jackson Laboratory web site, http://www.jax.org/) and the ever-expanding collection of molecular tools. To enhance the utility of the mouse system, we initiated a program to generate a large database of expressed sequence tags (ESTs) that can provide rapid access to genes. Of particular significance was the possibility that cDNA libraries could be prepared from very early stages of development, a situation unrealized in human EST projects. We report here the development of a comprehensive database of ESTs for the mouse. The project, initiated in March 1996, has focused on 5' end sequences from directionally cloned, oligo-dT primed cDNA libraries. As of 23 October 1998, 352,040 sequences had been generated, annotated and deposited in dbEST, where they comprised 93% of the total ESTs available for mouse. EST data are versatile and have been applied to gene identification, comparative sequence analysis, comparative gene mapping and candidate disease gene identification, genome sequence annotation, microarray development and the development of gene-based map resources.

How much should patients be told about their medication?

Much has been written on the education of patients about their medication, and yet what patients need to know has not been identified and agreed upon by professionals. This study sought to design a tool for this purpose using a series of interviews with experts to identify categories of information. Many core categories were identified and ambiguous sections such as 'side-effects' were clarified. A test-re-test strategy was used to identify the reliability of the resulting questionnaire. A high level of inconsistencies and a low response rate were, in part, attributable to poor design and distribution of the questionnaire. Other contributory factors and the reluctance/inability of respondents to identify what they felt patients should know about their medication are discussed. Some deficits are identified, in addition to an agreement that current systems for educating patients are inadequate. Areas for future research are also identified.

Learning from patients

Patients and relatives often assume nurses have a higher level of knowledge than they actually possess. In the search for a professional body of knowledge, nurses may underestimate the valuable lessons patients can teach them. The nursing press may exacerbate the theory-practice gap by underrepresenting the experiences of patients, careers and relatives.

Expression of the connexin43 gap junctional protein in tissues at the tip of the chick limb bud is related to the epithelial-mesenchymal interactions that mediate morphogenesis

The pattern of connexin43 expression in developing chick limb buds was examined using a site-specific polyclonal antibody and confocal microscopy. Connexin43 is expressed at stages of limb development when epithelial-mesenchymal interactions are occurring that mediate morphogenesis. Extensive labeling was observed in the apical ectodermal ridge and labeling was also found in underlying mesenchyme cells at the tip of the bud. In mouse limb buds, the same gap junction protein is expressed only in the apical ridge. Manipulations of developing chick wing buds show that mesenchymal expression of connexin43 appears to be controlled by the apical ectodermal ridge. When the apical ridge is surgically removed and limb truncations result, mesenchymal labeling is markedly reduced and conversely the grafting of an additional ridge induces connexin43 expression between underlying mesenchymal cells which do not normally show expression at this stage of development. In addition, a treatment with retinoic acid that flattens the apical ridge and inhibits bud outgrowth reduces expression in both mesenchymal and epithelial tissues. The abolition of connexin43 expression in mesenchymal and epithelial domains when bud outgrowth is halted suggests that synthesis of this gap junction protein is related to the epithelial-mesenchymal interactions that mediate morphogenesis of the bud.

Lack of demonstrable chromosome allele loss in hepatocellular adenoma

Several studies of loss of constitutional genetic heterozygosity in the development of hepatocellular carcinoma have been carried out with the aim of determining the location of relevant tumour suppressor genes, but there is as yet no report of a similar investigation in hepatocellular adenomas. In this study we analyzed six such patients searching for evidence of chromosome allele loss, or loss of heterozygosity, with 25 DNA probes recognising restriction fragment length polymorphisms. The 25 probes have been assigned to 21 chromosome arms. None of those probes detected allele loss in any of the 6 tumours. One of the patients had a synchronous hepatocellular carcinoma. Chromosome 17p allele loss was detected in her hepatocellular carcinoma but not in the adenoma. The study suggests that chromosome allele loss is not a frequent genetic change in the development of hepatocellular adenoma.

Loss of constitutional heterozygosity on chromosomes 5 and 17 in cholangiocarcinoma

It has been established that loss of tumour suppressor genes is crucial in carcinogenesis. There has been no reported study on searching for tumour suppressor genes in cholangiocarcinomas as yet. In order to investigate the loss of heterozygosity (LOH), which may represent such gene loss, in cholangiocarcinoma, we studied 14 patients with this tumour using restriction fragment length polymorphism analysis. Twenty-two probes assigned to chromosomes 1, 5, 7, 9, 11, 12, 13, 14, 16, 17 and 18 were used. Allelic losses were found in chromosomal regions 5q35-qter and 17p13. Loss of genetic material in these regions in cholangiocarcinoma was shared with hepatocellular carcinoma. Probes for other chromosomes have as yet shown no consistent LOH. In conclusion, this study for the first time showed LOH on chromosomes 5 and 17 in cholangiocarcinoma.

Molecular genetic evidence for the delineation of a more severe form of familial adenomatous polyposis which results from fresh mutation

Familial adenomatous polyposis, an inherited pre-malignant condition, is caused by mutation in the adenomatous polyposis coli (APC) gene at chromosome 5q22. The lifetime risk of carcinoma approaches 100%, with an average age at death from cancer of 40 years, allowing most patients to complete reproduction. Since there is no evidence for a rising incidence, this is at variance with an apparently high mutation rate. We present evidence for the delineation of a severe form, which hitherto has largely been maintained by fresh mutation. An atypically high frequency of loss of heterozygosity at chromosome 5q22 in small adenomas correlated with an early age of onset or malignancy in two patients, both due to fresh mutation. In both cases, the mutation in APC was shown to be a commonly occurring deletion, leading us to postulate the co-existence of a modifying gene.

Infrequent chromosome allele loss in fibrolamellar carcinoma

As yet, there is no reported study of chromosome allele loss in fibrolamellar carcinoma (FLC), a distinct, rare variant of hepatocellular carcinoma (HCC). We searched for evidence of allele loss in FLC using 18 DNA probes for 10 chromosomes and compared the pattern of loss with our series of HCC. Two of the probes, lambda MS32 (1q42-43) and cMS621 (5p) showed allele losses in one tumour, while other probes showed no loss. The frequency of allele loss in FLC was much lower than in HCC, which may be associated with their different prognoses.

The putative tumor suppressor gene on chromosome 5q for hepatocellular carcinoma is distinct from the MCC and APC genes

We have previously shown that the tumor suppressor gene for hepatocellular carcinoma (HCC) without cirrhosis may be located on chromosome 5q35-qter. In this study, we analyzed nine cases of primary HCC without cirrhosis using probes from the MCC and APC genes, which are in the region 5q21-22. None of the informative cases had allele loss detected by these probes, whereas the probe lambda MS8 for the region 5q35-qter showed allele loss in six out of six informative cases. The results confirm that the putative tumor suppressor gene for HCC without cirrhosis on chromosome 5q is distinct from the MCC and APC genes.

Different DNA changes in primary and recurrent hepatocellular carcinoma

DNA restriction fragment length polymorphism analysis was carried out on a primary and recurrent hepatocellular carcinoma in a hepatitis B virus negative patient. For the primary tumour, allele losses were found on the short arm of chromosome 17 (probe: p144-D6, 17p13) and the long arm of chromosome 5 with the probe Lambda MS8 (5q35-qter); other probes showed either no allele loss or a non-informative pattern. The recurrent cancer also showed allele loss with p144-D6, but not with Lambda MS8. In addition, the recurrent tumour had allele losses with Lambda MS43 (12q24.3-qter), pYNZ22 (17p13), and DNA rearrangement revealed by the probe Lambda MS32 (1q42-43), a pattern not seen in the primary lesion. These results indicate that the second hepatocellular carcinoma was of independent clonality and probably represents a de novo neoplasm rather than a recurrence.

Loss of heterozygosity on chromosomes 1 and 11 in carcinoma of the pancreas

Little is known of the molecular-genetic changes in carcinoma of the pancreas (CaP). In order to investigate the allele loss, or loss of heterozygosity (LOH), in CaP, we studied 13 patients with exocrine CaP and two with endocrine CaP using restriction fragment length polymorphism analysis. Twenty probes assigned to chromosomes 1, 5, 7, 9, 11, 12, 13, 14, 16, 17 and 18 were used. The frequency of LOH, or fractional allele loss (FAL), was found in two endocrine tumours to be 0.333 and 0.455 respectively; and FAL in 13 oxocrine tumours ranged from 0 to 0.25. Allele loss was shown in both exocrine and endocrine tumours by the probes Lambda MS1 at 1p33-35, and pMS51 at 11q13. Probes for other chromosomes have as yet shown no consistent LOH. In conclusion, the study showed LOH on chromosomes 1 and 11 in both exocrine and endocrine CaP.

Loss of constitutional heterozygosity on chromosome 5q in hepatocellular carcinoma without cirrhosis

Suppressor gene loci involved in the development of hepatocellular carcinoma (HCC) have not been fully identified. The aim of this study was to look for consistent allele loss, or loss of heterozygosity (LOH), in HCC which might represent such gene loci. We have prepared DNA from tumour and non-tumour material from 16 patients with HCC (nine with and seven without liver cirrhosis). Tumour DNA was compared with non-tumour DNA by Southern analysis performed with a panel of 22 probes recognising restriction fragment length polymorphisms assigned to chromosomes 1, 4, 5, 7, 9, 11, 12, 13, 14, 16, 17, 18 and 20. Non-tumour DNA from five of the seven patients with HCC without cirrhosis was heterozygous with the probe Lambda MS8 (5q35-qter), and in all five there was LOH in tumour DNA. Probes for other regions of chromosome 5 have as yet shown no LOH in this group of patients. Cirrhotic HCC patients exhibited LOH on chromosomes 1q and 5p but not in the region 5q35-qter. Both groups of HCC showed LOH on chromosome 17p13. Screening with other probes has not shown any consistent LOH in either group as yet. A comparison of LOH on chromosome 5 in seven patients with colorectal metastasis in the liver showed a different pattern, which suggests that the proposed tumour suppressor gene locus for HCC without cirrhosis on chromosome 5 appears to be distinct from the familial adenomatous polyposis coli gene.