From first symptoms to diagnosis of amyotrophic lateral sclerosis: perspectives of an Irish informal caregiver cohort-a thematic analysis

OBJECTIVES

Informal caregivers play an integral part in the management of amyotrophic lateral sclerosis (ALS). The objective of this study was to explore the journey from first problem symptoms to diagnosis from the perspective of informal caregivers providing care to people with ALS.

DESIGN

As part of a semistructured interview, information was collected on a range of caregiver demographic details, and from an open-ended question their experiences of the time of symptom onset to diagnosis. We carried out descriptive statistical analysis and thematic analysis of qualitative data.

SETTING AND PARTICIPANTS

Home interviews with informal caregivers (n=74) of people with ALS attending the National ALS/Motor Neuron Disease Clinic at Beaumont Hospital, Dublin, Ireland.

RESULTS

This was a largely female and spousal cohort of caregivers, living with the patient for whom they provided informal care. The majority of patients were men and were spinal onset. Caregivers described the time from first symptoms to diagnosis. Using a primarily inductive approach, the coding was data driven and the codes and themes derived from the content of these descriptions. Two main themes were identified (1) problem signs and symptoms (A) noticing and (B) reaction; (2) interaction with the health services.

CONCLUSIONS

Exploring the perspectives of caregivers from first problem symptoms to diagnosis provides valuable insights into the development of the condition, impediments to its recognition, help-seeking behaviours and interactions with healthcare services. The journey from early symptoms to diagnosis is important for future decision-making, affects readiness for caregiving and could negatively impact on caregiver health and well-being. The early acknowledgement by healthcare professionals of stressors along the journey to diagnosis, and appreciation of their possible impact on caregivers is important. The separate needs of caregivers should be assessed on a regular basis.

Caregivers of patients with amyotrophic lateral sclerosis: investigating quality of life, caregiver burden, service engagement, and patient survival

Few studies in amyotrophic lateral sclerosis (ALS) have profiled disease-specific features of the condition in conjunction with assessment of caregivers' burden, distress, quality of life, and investigated patient survival. Eighty-four ALS patients and their primary caregivers were enrolled. Patients completed ALS-specific measures of physical and cognitive function, while caregivers completed measures of anxiety, depression, caregiver burden, and quality of life. Patient-caregiver dyads were interviewed about their health-service utilisation. Survival data were obtained through the Irish register for ALS. Participants were dichotomised into low/high groups according to the severity of self-reported caregiver burden, based on statistically derived cut-off scores. High-burdened caregivers (n = 43) did not significantly differ from low-burdened caregivers (n = 41) with respect to disease-specific characteristics, i.e., ALSFRS-R, bulbar- or spinal-onset ALS, disease duration, or survival data. However, significant differences were reported on subjective measures of anxiety (p < 0.000), depression (p < 0.001), distress (p < 0.000), and quality of life (p < 0.000). These data demonstrate the limited impact of ALS patient-related variables, i.e., ALSFRS-R and onset, on caregiver burden in ALS, and identify the importance of the psychological composition of caregivers. This study suggests that the subjective experience of individual caregivers is an important factor influencing the severity of experienced caregiver burden.

Caregiving in ALS - a mixed methods approach to the study of Burden

Background

Caregiver burden affects the physical, psychological and emotional well-being of the caregiver. The purpose of this analysis was to describe an informal caregiver cohort (n = 81), their subjective assessment of burden and difficulties experienced as a result of providing care to people with Amyotrophic Lateral Sclerosis (ALS).

Methods

Using mixed methods of data collection and analysis, we undertook a comprehensive assessment of burden and difficulties associated with informal caregiving in ALS. As part of a semi-structured interview a series of standardised measures were used to assess quality of life, psychological distress and subjective burden, and in an open-ended question caregivers were asked to identify difficult aspects of their caregiving experience.

Results

The quantitative data show that psychological distress, hours of care provided and lower quality of life, were significant predictors of caregiver burden. From the qualitative data, the caregiving difficulties were thematised around managing the practicalities of the ALS condition, the emotional and psychosocial impact; limitation and restriction, and impact on relationships.

Conclusions

The collection and analysis of quantitative and qualitative data better explores the complexity of caregiver burden in ALS. Understanding the components of burden and the difficulties experienced as a result of caring for someone with ALS allows for better supporting the caregiver, and assessing the impact of burden on the care recipient.

Electronic supplementary material

The online version of this article (doi:10.1186/s12904-016-0153-0) contains supplementary material, which is available to authorized users.

Tumourigenic non-small-cell lung cancer mesenchymal circulating tumour cells: a clinical case study

BACKGROUND

Over the past decade, numerous reports describe the generation and increasing utility of non-small-cell lung cancer (NSCLC) patient-derived xenografts (PDX) from tissue biopsies. While PDX have proven useful for genetic profiling and preclinical drug testing, the requirement of a tissue biopsy limits the available patient population, particularly those with advanced oligometastatic disease. Conversely, 'liquid biopsies' such as circulating tumour cells (CTCs) are minimally invasive and easier to obtain. Here, we present a clinical case study of a NSCLC patient with advanced metastatic disease, a never smoker whose primary tumour was EGFR and ALK wild-type. We demonstrate for the first time, tumorigenicity of their CTCs to generate a patient CTC-derived eXplant (CDX).

PATIENTS AND METHODS

CTCs were enriched at diagnosis and again 2 months later during disease progression from 10 ml blood from a 48-year-old NSCLC patient and implanted into immunocompromised mice. Resultant tumours were morphologically, immunohistochemically, and genetically compared with the donor patient's diagnostic specimen. Mice were treated with cisplatin and pemetrexed to assess preclinical efficacy of the chemotherapy regimen given to the donor patient.

RESULTS

The NSCLC CDX expressed lung lineage markers TTF1 and CK7 and was unresponsive to cisplatin and pemetrexed. Examination of blood samples matched to that used for CDX generation revealed absence of CTCs using the CellSearch EpCAM-dependent platform, whereas size-based CTC enrichment revealed abundant heterogeneous CTCs of which ∼80% were mesenchymal marker vimentin positive. Molecular analysis of the CDX, mesenchymal and epithelial CTCs revealed a common somatic mutation confirming tumour origin and showed CDX RNA and protein profiles consistent with the predominantly mesenchymal phenotype.

CONCLUSIONS

This study shows that the absence of NSCLC CTCs detected by CellSearch (EpCAM(+)) does not preclude CDX generation, highlighting epithelial to mesenchymal transition and the functional importance of mesenchymal CTCs in dissemination of this disease.

Survival analysis of geospatial factors in the Irish ALS cohort

Variations in environmental risk factors potentially influence incidence and progression in complex multifactorial diseases. Few studies have examined the association of survival in amyotrophic lateral sclerosis (ALS) with environmental geospatial variables. Here we use data from the Irish ALS cohort to perform such an analysis. Geographic data sources were used to generate small area values for four geospatial variables (population density, social deprivation, distance to coast, and distance to ALS multidisciplinary (MDT) clinic) for each ALS case on the Irish ALS register. These were combined with follow-up data and used as covariates in Royston-Parmar regression survival analysis including age of onset, site of onset, diagnostic delay, riluzole prescription and MDT clinic attendance as covariates. One thousand, two hundred and thirty-two patients with median survival of 2.31 years from disease onset were included. After addition of the individual geospatial variables in turn, none of the four variables was found to be associated with survival with a p-value <0.05. The results may reflect the public healthcare system that provides riluzole prescription and access to the MDT to all patients free of charge, and is also congruent with our recent finding that social deprivation is not associated with ALS incidence in Ireland.

Patient journey to a specialist amyotrophic lateral sclerosis multidisciplinary clinic: an exploratory study

Background

The multidisciplinary approach in the management of Amyotrophic Lateral Sclerosis (ALS) has been shown to provide superior care to devolved care, with better survival, improved quality of care, and quality of life. Access to expert multidisciplinary management should be a standard for patients with ALS. This analysis explores the patient journey from symptom onset and first engagement with health services, to the initial visit to a specialist ALS Multidisciplinary Clinic (MDC) in Dublin, Ireland.

Methods

A retrospective exploratory multi-method study details the patient journey to the MDC. Data from medical interviews and systematic chart review identifies interactions with the health services and key timelines for thirty five new patients presenting with a diagnosis of ALS during a 6 month period in 2013.

Results

The time from first symptom to diagnosis was a mean of 16 months (median 13 months), with a mean interval of 19 months (median 14.6) from first symptoms to arrival at the MDC. The majority of patients were seen by a general practitioner, and subsequently by neurology services. There was an average of four contacts with health services and 4.8 investigations/tests, prior to their first Clinic visit. On the first visit to the MDC patients are linked into an integrated ‘system’ that can provide specialist care and link with voluntary, palliative and community services as required.

Conclusions

Engagement with a multidisciplinary team has implications for service utilization and quality of life of patients and their families. We have demonstrated that barriers exist that delay referral to specialist services. Comprehensive data recording and collection, using multiple data sources can reconstruct the timelines of the patient journey, which can in turn be used to identify pathways that can expedite early referral to specialist services.

Opening-wedge high tibial osteotomy with a secure bone allograft (Osteopure™) and locked plate fixation: Retrospective clinical and radiological evaluation of 69 knees after 7.5years follow-up

BACKGROUND

Medial opening-wedge high tibial osteotomy (OWHTO) provides reliable and long-lasting benefits, despite the wide range of wedge-filling and internal-fixation techniques used. The purpose of this work was to assess the clinical and radiological outcomes in a case-series of OWHTO performed using a secure bone allograft and locked plate fixation.

HYPOTHESIS

The clinical and radiological outcomes of OWHTO with a high-safety bone allograft and locked plate fixation are similar to those reported in previous case-series studies.

MATERIALS AND METHODS

A single-centre retrospective design was used to study 69 knees in 64 patients with a mean age of 51.8years (31-53years) and a preoperative hip-knee-ankle (HKA) angle of 173° (165°-180°). The wedge was filled with secure Osteopure™ bone allograft and fixation was achieved using an Integra Surfix(®) locked plate. Mean follow-up was 7.5years (5-9.3years). Clinical and functional outcomes were assessed by determining the IKS and KOOS-PS scores and recording complications related or unrelated to the allograft. The main criterion for assessing OWHTO survival was the time to revision surgery for symptom recurrence. Radiological assessment criteria were the HKA angle, tibial slope, patellar height, and osteoarthritis grade. GESTO criteria were used to evaluate the behaviour of the allograft.

RESULTS

Of the 69 knees, 64 (92.8%) were re-evaluated. The survival rate after 9.3years was 95%±2.7% (3 failures managed with arthroplasty). The functional IKS score improved significantly, by 20 points (P<0.001). Mean increases of 7.8° for the HKA angle and 3.5° for tibial slope were recorded. Bone healing without radiological abnormalities was consistently achieved within 6months. There were no complications related to the allograft (infections, allergies; local or systemic toxicity).

DISCUSSION

The clinical, radiological, and safety outcomes documented in our study were similar to those reported in earlier work.

LEVEL OF EVIDENCE

IV, retrospective case-series study.

Caregiver burden in amyotrophic lateral sclerosis: a cross-sectional investigation of predictors

The objective of the study was to investigate whether cognitive and behavioural impairment in Amyotrophic Lateral Sclerosis (ALS) contributes to caregiver burden, and whether carer burden affects patient outcome. Thirty-three dyads of incident patients with ALS and their primary caregivers (n = 33) completed a series of measures to determine cognitive and behavioural profiles, (patients) and carer burden (carers) to investigate the psychological impact of ALS, and the impact of behavioural change since the onset of ALS. Caregivers were divided into high- and low-burden groups using previously established norms. High burden in carers was associated with significantly higher apathy (p = 0.009), disinhibition (p = 0.005), and executive dysfunction (p = 0.015) in patients. Regression analyses for burden confirmed significant predictors such as change in apathy (r = 0.390, F = 5.19, p = 0.03), disinhibition (r = 0.530, F = 11.32, p = 0.002), and executive dysfunction (r = 0.372, F = 4.66, p = 0.039), with total behaviour change contributing to 31 % of caregiver burden (r = 0.563, F = 4.17, p = 0.015). Total distress as measured by the Hospital Anxiety and Depression Scale was also a significant predictor of caregiver burden, contributing to 38.5 % of variance (r = 0.621, F = 18.79, p < 0.000). Caregiver burden did not affect survival (p = 0.496). Caregiver burden in ALS is modulated by patient's cognitive and behavioural status, but does not significantly impact patient survival.

End-of-life management in patients with amyotrophic lateral sclerosis

Most health-care professionals are trained to promote and maintain life and often have difficulty when faced with the often rapid decline and death of people with terminal illnesses such as amyotrophic lateral sclerosis (ALS). By contrast, data suggest that early and open discussion of end-of-life issues with patients and families allows time for reflection and planning, can obviate the introduction of unwanted interventions or procedures, can provide reassurance, and can alleviate fear. Patients' perspectives regarding end-of-life interventions and use of technologies might differ from those of the health professionals involved in their care, and health-care professionals should recognise this and respect the patient's autonomy. Advance care directives can preserve autonomy, but their legal validity and use varies between countries. Clinical management of the end of life should aim to maximise quality of life of both the patient and caregiver and, when possible, incorporate appropriate palliation of distressing physical, psychosocial, and existential distress. Training of health-care professionals should include the development of communication skills that help to sensitively manage the inevitability of death. The emotional burden for health-care professionals caring for people with terminal neurological disease should be recognised, with structures and procedures developed to address compassion, fatigue, and the moral and ethical challenges related to providing end-of-life care.

The importance of composite foods for estimates of vegetable and fruit intakes

Objective:

To evaluate the contribution of composite foods to vegetable and fruit intakes in Irish adults and to compliance with dietary guidelines for vegetable and fruit intake.

Design:

Data were analysed from the North/South Ireland Food Consumption Survey of 18–64-year-old adults (n= 1379; 662 men, 717 women), which used a 7-day food diary to estimate food intake.

Results:

The mean intake of vegetables (excluding potatoes) was 140g day−1(men 149g day−1; women 132g day−1), of fruit was 136 g day−1(men 133g day−1; women 140 g day−1) and of potatoes was 227 g day−1(men 296g day−1; women 163 g day−1). The mean daily intakes of vegetables, fruit and potatoes from composite foods were 37 g (26%), 6 g (5%) and 17 g (7%), respectively. The mean intake of vegetables from composite foods was unrelated to age or gender, but increased with increasing social class and level of education attained. The proportions of men and women meeting the recommendation for ≥400g day−1(5 servings of 80 g per day) of vegetables and fruit were 21% (15% excluding composite foods) and 19% (12% excluding composite foods), respectively. Compliance with the dietary recommendation decreased with decreasing levels of educational attainment and social class.

Conclusion:

Intakes of vegetables and fruit are low compared with current dietary recommendations, particularly in those of lower levels of educational attainment and social class. Composite foods are an important source of vegetables (less importantly of fruit) and should be included when estimating vegetable intakes. Failure to do so may result in bias in estimates of intake and of compliance with dietary guidelines for population groups, as well as misclassification of individuals by level of intake.

Evaluation of a spray-dried lacticin 3147 powder for the control of Listeria monocytogenes and Bacillus cereus in a range of food systems

AIMS

The potential of a powdered preparation of the bacteriocin, lacticin 3147, was investigated for the inhibition of Listeria monocytogenes and Bacillus cereus.

METHODS AND RESULTS

A 10% solution of reconstituted demineralized whey powder was fermented with Lactococcus lactis DPC3147 for the generation of a lacticin 3147 containing powdered product. A 99.9% reduction in L. monocytogenes numbers occurred in the presence of the lacticin 3147 powder within 2 h in natural yogurt, and an 85% reduction was observed in cottage cheese within the same time frame. Counts of B. cereus were reduced by 80% in soup, in the presence of 1% (w/w) lacticin 3147 powder, within 3 h.

CONCLUSIONS

A powdered preparation of lacticin 3147 was effective for the control of Listeria and Bacillus in natural yogurt, cottage cheese and soup.

SIGNIFICANCE AND IMPACT OF THE STUDY

The bioactive lacticin 3147 powder may find broad applications for control of Gram-positive pathogens/spoilage bacteria in a range of foods.

Physical activity patterns in a nationally representative sample of adults in Ireland

OBJECTIVE

To evaluate habitual levels of physical activity in a nationally representative sample of adults in Ireland.

DESIGN

Cross-sectional survey using a self-administered questionnaire. Usual levels of work, recreational and household activities were evaluated in relation to anthropometric, demographic and socio-economic characteristics. The amount and intensity of all activities were quantified by assigning metabolic equivalents (METS) to each activity.

SETTING

Republic of Ireland and Northern Ireland, 1997-1999.

SUBJECTS

Random sample of 1379 adults aged 18-64 years.

RESULTS

Men were approximately twice as active in work and recreational activity (139.7 +/- 83.9 METS) as women (68.5 +/- 49.8 METS; P<0.001) but women were three times more active in household tasks (65.9 +/- 58.7 METS vs. 22.6 +/- 24.6 METS; P<0.001). Overall levels of physical activity declined with increasing age, particularly leisure activity in men. In women the decline in work activity was offset by spending more time in household pursuits. Twenty-five per cent of the subjects were extremely overweight (body mass index (BMI>28 kg m(-2)) or obese (BMI >30 kg m (-2)). Fewer obese subjects reported higher levels of work and leisure activities. However, a higher percentage of obese women reported participation in the higher levels of household activities. Participation rates in recreational activities were low. Walking was the most important leisure activity of both men (41%) and women (60%). In terms of hours per week spent in vigorous physical activity, men were more active than women, professional and skilled non-manual women were more active than women in other social classes, and younger subjects (aged 18-35 years) were more active than older subjects.

CONCLUSIONS

The holistic approach used in the assessment of physical activity in this study has revealed important and subtle differences in the activity patterns of men and women. Failure to fully characterise the respective activity patterns of men and women could lead to ill-informed public health policy aimed at promoting and sustaining lifetime habits of physical activity. The results suggest that simple population-focused programmes to promote physical activity are unlikely to offer the same chance of long-term success as more sensitive and individualised strategies.

High prevalence of the very rare Wilson disease gene mutation Leu708Pro in the Island of Gran Canaria (Canary Islands, Spain): a genetic and clinical study

The molecular basis of Wilson disease (WD), an autosomal recessive disorder, is the presence of mutations in the ATP7B gene, a copper transporting ATPase. Hospital records indicated a higher prevalence of WD (1 in 2,600) in some counties in the northeastern region of the island of Gran Canaria (Canary Islands, Spain) that was around 10-fold higher than that described for European populations (1 in 30,000). The ATP7B gene was analyzed for mutations in 24 affected subjects, revealing a high prevalence of the rare Leu708Pro mutation present in 12 homozygous and 7 heterozygous individuals. In these patients, who constitute one of the largest described cohorts of WD homozygotes, we found a variable clinical presentation of the disease, although the biochemical picture was homogenous and characteristic, thereby confirming that the Leu708Pro change is indeed a mutation associated with WD. Haplotype analysis of subjects homozygous for the Leu708Pro mutation showed a conserved shared region smaller than 1 centimorgan (cM), and the region of linkage disequilibrium between the Leu708Pro mutation and neighboring microsatellite markers extended approximately 4.6 cM. When comparing the amount of linkage disequilibrium versus genetic distance from the disease mutation, it was estimated that a common ancestral Leu708Pro chromosome may have been introduced in Gran Canaria over 56 generations ago, dating it back to pre-Hispanic times. The prevalence, and the tight geographical distribution of the Leu708Pro chromosome suggests that the Canary Islands can be considered a genetic isolate for linkage disequilibrium studies.

Physical mapping of the CXC chemokine locus on human chromosome 4

A physical map of the CXC chemokine locus on chromosome 4 has been constructed by PCR analysis and PFGE mapping of YAC clones. The genes for IL8, GRO1, PPBP, PF4, SCYB5 (ENA-78) and SCYB6 (GCP-2) have been co-localized on a 335-kb genomic fragment. The GRO2 and GRO3 genes did not map within this region and based on analysis of a YAC contig overlapping IL8 we speculate that GRO2 and GRO3 map downstream of this region. We have also assigned the novel CXC chemokine gene, SCYB9B (alias H174/betaR1) to chromosome 4q21, upstream and within 12 kb of INP10. Like INP10 and MIG, INP10 and SCYB9B are arranged in a head to tail manner. The chromosomal arrangement of these genes appears to reflect the evolution of this multigene family and supports the theory that it arose by gene duplication.

Melanocortin 3 receptor (MC3R) gene variants in extremely obese women

OBJECTIVE

Following several reports of linkage of obesity related phenotypes to human chromosome 20q we sought to determine whether variations of the melanocortin 3 receptor (MC3R) gene are associated with obesity.

DESIGN

We screened the MC3R gene coding region and approximately 2 kb of 5' and 3' flanking sequences for DNA variants in unrelated extremely obese women and average weight controls using polymerase chain reaction (PCR) single strand conformation polymorphism (SSCP) analysis and DNA sequencing.

SUBJECTS

124 unrelated extremely obese women (body mass index, (BMI)>/=40 kg/m2) and 85 average weight controls (BMI<27 kg/m2).

MEASUREMENTS

Radiation hybrid (RH) mapping was performed to localize the MC3R gene. 5' and 3' flanking sequences of MC3R gene were cloned. PCR-SSCP and DNA sequencing were used to detect mutations in the MC3R gene coding region and flanking sequences.

RESULTS

RH mapping localized the MC3R gene to 20q13, between markers D20S100 and D20S149. 1083 bp 5' and 653 bp 3' flanking region of the MC3R gene were cloned. A missense mutation (+241, codon 81 ATT/GTT, Ile-->Val) was found in the MC3R coding region. Four more variants were detected in the 5' flanking sequence: -201(C-->G), -239 (A-->G), -762(A-->T) and -769(T-->C). Compared with controls, no significant allele frequency differences were found. Racial differences were found for the +241, -201, -239 and -762 polymorphisms.

CONCLUSIONS

Several sequence variants were found in the MC3R gene coding region and in 5' flanking sequences. However, none of the variants were associated with obesity phenotypes. The linkage of extreme human obesity on 20q13 is likely caused by genes other than MC3R. International Journal of Obesity (2000) 24, 206-210

Development of a lacticin 3147-enriched whey powder with inhibitory activity against foodborne pathogens

The broad-spectrum bacteriocin lacticin 3147, produced by Lactococcus lactis DPC3147, is inhibitory to a wide range of gram-positive food spoilage and pathogenic organisms. A 10% solution of demineralized whey powder was fermented with DPC3147 at a constant pH of 6.5. The fermentate was spray dried, and the resulting powder exhibited inhibitory activity. The ability of the lacticin 3147-enriched powder to inhibit Listeria monocytogenes Scott A and Staphylococcus aureus 10 was assessed in buffer at both acidic (pH 5) and neutral (pH 7) pH. In addition, the ability of the powder to inhibit L. monocytogenes Scott A in an infant milk formulation was assessed. Resuspension of approximately 10(8) midexponential phase L. monocytogenes Scott A cells in a 10% solution of the lacticin 3147-enriched powder resulted in a 1,000-fold reduction in viable cells at pH 5 and pH 7 after 3 h at 30 degrees C. In the case of S. aureus 10, resuspension of 2.5 x 10(7) midexponential phase cells in a 15% solution of the lacticin 3147-enriched powder at pH 5 resulted in only a 10-fold reduction in viable cell counts, compared with a 1,000-fold reduction at pH 7, following incubation for 3 h at 30 degrees C. The use of the lacticin 3147 powder in an infant milk formulation resulted in greater than a 99% kill of L. monocytogenes within 3 h at 30 degrees C. These results suggest that this bioactive lacticin 3147 food ingredient may find applications in many different foods, including those with pH close to neutrality.

Developing applications for lactococcal bacteriocins

While much of the applied research carried out to date with bacteriocins has concerned nisin, lactococci produce other bacteriocins with economic potential. An example is the two component bacteriocin lacticin 3147, which is active over a wide pH range and has a broad spectrum of activity against gram-positive bacteria. Since the genetic determinants for lacticin 3147 are encoded on a large self-transmissible plasmid, the bacteriocin genes may be conveniently transferred to different lactococcal starters. The resulting food-grade strains can then be used to make a significant impact on the safety and quality of a variety of fermented foods, through the inhibition of undesirable microflora. The bacteriocin is heat stable so it can also be used as an ingredient in a powdered form such as a spray-dried fermentate. Given the observation that lacticin 3147 is effective at physiological pH, there is also considerable potential for biomedical applications. Field trials have demonstrated its efficacy in the prevention of mastitis infections in dairy cows. In contrast to lacticin 3147, the lactococcin bacteriocins A, B and M have a narrow spectrum of activity limited to lactococci. Strains which produce these inhibitors can be exploited in the acceleration of cheese ripening by assisting the premature lysis of starter cultures.

Fast and reliable screening of mutations in human tumors: use of multiple fluorescence-based long linker arm nucleotides assay (mf-LLA)

Human tumor samples were screened for point mutations by adapting a mobility-shift assay to automated DNA sizing. This screen identifies the type of point mutation and relative amount of mutated DNA sequences present in a sample. Test samples having known hypoxanthine-guanine phosphoribosyl transferase (hprt)/exon-3 sequence mutations were characterized by: (i) PCR amplification, (ii) fluorescent dye-primer extension with 36-atom linker derived deoxycytosine or deoxyuridine triphosphate and the remaining three natural nucleotides and (iii) sizing of the resulting fluorescently labeled modified strands, using an automated DNA sequencer. Routinely, a range of sizes is observed among the sequence variants of a single DNA target sequence. This is because nucleotide analogs are incorporated into DNA strands in a sequence-dependent manner, resulting in composition-dependent electrophoretic mobility. Thus, point mutations are identified as shifts in mobility between the fluorescently labeled modified strands of the control and test samples. The twenty different hprt/exon-3 single-base substitution mutations tested were easily identified, even at fourfold dilution with control DNA.

Lacticin 3147 displays activity in buffer against gram-positive bacterial pathogens which appear insensitive in standard plate assays

Lacticin 3147 is a broad-spectrum bacteriocin produced by Lactococcus lactis subsp. lactis DPC3147, which has been shown to be active against a range of food-borne bacteria. The reported inhibitory range for lacticin is extended to include methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis, penicillin-resistant Pneumococcus, Propionibacterium acne and Streptococcus mutans. This extended host range is not obvious from traditional agar plate-based methods, but reductions in bacterial cell numbers by up to 6 log10 cfu ml-1 was observed after 2 h in time-kill curve studies conducted in broth, suggesting that the bacteriocin may have potential as a therapeutic agent in the treatment of human infections.

"A satellite primer on tuberculosis:" a collaboration in distance education

"A Satellite Primer on Tuberculosis" was offered as a distance-based certificate course on tuberculosis (TB) fundamentals to a national audience of over 5,000 individuals. The course was a collaborative effort of a school of public health, a state health department, and the Centers for Disease Control and Prevention. Instruction was provided through print-based self-study modules that were complemented by live, interactive satellite conferences. Course completers, over 70 percent of whom were nurses and employees of public health departments, scored significantly higher on a course posttest than on a pretest, and the vast majority felt the course provided valuable training.