Development of a Real-Time PCR Assay for the Detection and Identification of Rubus Stunt Phytoplasma in Rubus spp

Rubus stunt, caused by 'Candidatus Phytoplasma rubi' (Rubus stunt phytoplasma; RSP), is an economically important disease of Rubus. This disease occurs in wild and cultivated Rubus spp. in Europe but has not been reported from North America; however, its major leafhopper vector is well established in western Canada and the U.S.A. RSP has the potential to impact the cane-fruit industry by significantly compromising yields and impacting export potential for Rubus propagation material. To mitigate the risk of this disease entering or establishing, import and export testing of propagation material is a phytosanitary requirement in Canada, the U.S.A., and other countries regulating RSP. In the absence of a specific test for RSP, the current testing scheme involves the use of a generic test to screen for phytoplasmas followed by additional time-consuming procedures to confirm the phytoplasma species. In this study, a real-time PCR assay, targeting a 154-bp region of tuf gene, was developed for sensitive and specific detection of RSP in Rubus spp. The developed assay detected a minimum of five target copies, and no cross-reactivity was observed even with the 'Ca. P. rubi'-related strain associated with blackberry witches' broom, which differs from RSP only by a single nucleotide polymorphism in the target region. Repeatability of the developed assay was checked on two real-time PCR platforms with acceptable results. In conclusion, this real-time PCR assay provides a sensitive and specific detection of RSP for mitigating the introduction and spread of Rubus stunt disease in Rubus spp.

New Frontiers in Colorectal Cancer Treatment Combining Nanotechnology with Photo- and Radiotherapy

Colorectal cancer is the third most common cancer worldwide. Despite recent advances in the treatment of this pathology, which include a personalized approach using radio- and chemotherapies in combination with advanced surgical techniques, it is imperative to enhance the performance of these treatments and decrease their detrimental side effects on patients' health. Nanomedicine is likely the pathway towards solving this challenge by enhancing both the therapeutic and diagnostic capabilities. In particular, plasmonic nanoparticles show remarkable potential due to their dual therapeutic functionalities as photothermal therapy agents and as radiosensitizers in radiotherapy. Their dual functionality, high biocompatibility, easy functionalization, and targeting capabilities make them potential agents for inducing efficient cancer cell death with minimal side effects. This review aims to identify the main challenges in the diagnosis and treatment of colorectal cancer. The heterogeneous nature of this cancer is also discussed from a single-cell point of view. The most relevant works in photo- and radiotherapy using nanotechnology-based therapies for colorectal cancer are addressed, ranging from in vitro studies (2D and 3D cell cultures) to in vivo studies and clinical trials. Although the results using nanoparticles as a photo- and radiosensitizers in photo- and radiotherapy are promising, preliminary studies showed that the possibility of combining both therapies must be explored to improve the treatment efficiency.

Multilocus sequence typing of diverse phytoplasmas using hybridization probe-based sequence capture provides high resolution strain differentiation

Phytoplasmas are insect-vectored, difficult-to-culture bacterial pathogens that infect a wide variety of crop and non-crop plants, and are associated with diseases that can lead to significant yield losses in agricultural production worldwide. Phytoplasmas are currently grouped in the provisional genus ‘Candidatus Phytoplasma’, which includes 49 ‘Candidatus’ species. Further differentiation of phytoplasmas into ribosomal groups is based on the restriction fragment length polymorphism (RFLP) pattern of the 16S rRNA-encoding operon, with more than 36 ribosomal groups (16Sr) and over 100 subgroups reported. Since disease symptoms on plants are not associated with phytoplasma identity, accurate diagnostics is of critical importance to manage disease associated with these microorganisms. Phytoplasmas are typically detected from plant and insect tissue using PCR-based methods targeting universal taxonomic markers. Although these methods are relatively sensitive, specific and are widely used, they have limitations, since they provide limited resolution of phytoplasma strains, thus necessitating further assessment of biological properties and delaying implementation of mitigation measures. Moreover, the design of PCR primers that can target multiple loci from phytoplasmas that differ at the sequence level can be a significant challenge. To overcome these limitations, a PCR-independent, multilocus sequence typing (MLST) assay to characterize an array of phytoplasmas was developed. Hybridization probe s targeting cpn60, tuf, secA, secY, and nusA genes, as well as 16S and rp operons, were designed and used to enrich DNA extracts from phytoplasma-infected samples for DNA fragments corresponding to these markers prior to Illumina sequencing. This method was tested using different phytoplasmas including ‘Ca. P. asteris’ (16SrI-B), ‘Ca. P. pruni’ (16SrIII-A),‘Ca. P. prunorum’ (16SrX-B), ‘Ca. P. pyri’ (16SrX-C), ‘Ca. P. mali’ (16SrX-A), and ‘Ca. P. solani’ (16SrXII-A). Thousands of reads were obtained for each gene with multiple overlapping fragments, which were assembled to generate full-length (typically >2 kb), high-quality sequences. Phytoplasma groups and subgroups were accurately determined based on 16S ribosomal RNA and cpn60 gene sequences. Hybridization-based MLST facilitates the enrichment of target genes of phytoplasmas and allows the simultaneous determination of sequences corresponding to seven different markers. In this proof-of-concept study, hybridization-based MLST was demonstrated to be an efficient way to generate data regarding ‘Ca. Phytoplasma’ species/strain differentiation.

Assessment of myocardial viscoelasticity with Brillouin spectroscopy in myocardial infarction and aortic stenosis models

Heart diseases are associated with changes in the biomechanical properties of the myocardial wall. However, there is no modality available to assess myocardial stiffness directly. Brillouin microspectroscopy (mBS) is a consolidated mechanical characterization technique, applied to the study of the viscoelastic and elastic behavior of biological samples and may be a valuable tool for assessing the viscoelastic properties of the cardiac tissue. In this work, viscosity and elasticity were assessed using mBS in heart samples obtained from healthy and unhealthy mice (n = 6 per group). Speckle-tracking echocardiography (STE) was performed to evaluate heart deformation. We found that mBS was able to detect changes in stiffness in the ventricles in healthy myocardium. The right ventricle showed reduced stiffness, in agreement with its increased compliance. mBS measurements correlated strongly with STE data, highlighting the association between displacement and stiffness in myocardial regions. This correlation was lost in pathological conditions studied. The scar region in the infarcted heart presented changes in stiffness when compared to the rest of the heart, and the hypertrophied left ventricle showed increased stiffness following aortic stenosis, compared to the right ventricle. We demonstrate that mBS can be applied to determine myocardial stiffness, that measurements correlate with functional parameters and that they change with disease.

Brillouin Spectroscopy: From Biomedical Research to New Generation Pathology Diagnosis

Brillouin spectroscopy has recently gained considerable interest within the biomedical field as an innovative tool to study mechanical properties in biology. The Brillouin effect is based on the inelastic scattering of photons caused by their interaction with thermodynamically driven acoustic modes or phonons and it is highly dependent on the material's elasticity. Therefore, Brillouin is a contactless, label-free optic approach to elastic and viscoelastic analysis that has enabled unprecedented analysis of ex vivo and in vivo mechanical behavior of several tissues with a micrometric resolution, paving the way to a promising future in clinical diagnosis. Here, we comprehensively review the different studies of this fast-moving field that have been performed up to date to provide a quick guide of the current literature. In addition, we offer a general view of Brillouin's biomedical potential to encourage its further development to reach its implementation as a feasible, cost-effective pathology diagnostic tool.

Biomedical Applications of Tissue Clearing and Three-Dimensional Imaging in Health and Disease

Three-dimensional (3D) optical imaging techniques can expand our knowledge about physiological and pathological processes that cannot be fully understood with 2D approaches. Standard diagnostic tests frequently are not sufficient to unequivocally determine the presence of a pathological condition. Whole-organ optical imaging requires tissue transparency, which can be achieved by using tissue clearing procedures enabling deeper image acquisition and therefore making possible the analysis of large-scale biological tissue samples. Here, we review currently available clearing agents, methods, and their application in imaging of physiological or pathological conditions in different animal and human organs. We also compare different optical tissue clearing methods discussing their advantages and disadvantages and review the use of different 3D imaging techniques for the visualization and image acquisition of cleared tissues. The use of optical tissue clearing resources for large-scale biological tissues 3D imaging paves the way for future applications in translational and clinical research.

Apple hammerhead viroid-like RNA is a bona fide viroid: Autonomous replication and structural features support its inclusion as a new member in the genus Pelamoviroid

Apple hammerhead viroid-like RNA (AHVd RNA) has been reported in different apple cultivars and geographic regions and, considering the presence of hammerhead ribozymes in both polarity strands, suspected to be either a viroid of the family Avsunviroidae or a viroid-like satellite RNA. Here we report that dimeric head-to-tail in vitro transcripts of a 433-nt reference variant of AHVd RNA from cultivar "Pacific Gala" are infectious when mechanically inoculated to apple, thus showing that this RNA is a bona fide viroid for which we have kept the name apple hammerhead viroid (AHVd) until its pathogenicity, if any, is better assessed. By combining thermodynamics-based predictions with co-variation analyses of the natural genetic diversity found in AHVd we have inferred the most likely conformations for both AHVd polarity strands in vivo, with that of the (+) polarity strand being stabilized by a kissing loop-interaction similar to those reported in peach latent mosaic viroid and chrysathemum chlorotic mottle viroid, the two known members of the genus Pelamoviroid (family Avsunviroidae). Therefore, AHVd RNA fulfills the biological and molecular criteria to be allocated to this genus, the members of which, intriguingly, display low global sequence identity but high structural conservation.

Improving stall design: use of 3-D kinematics to measure space use by dairy cows when lying down

Uncomfortable stalls reduce the time cows spend resting and are a risk factor for lameness. Although recommendations for stall dimensions are available, little research supports these recommendations. In this study, kinematic techniques were used to provide the first accurate measures of space used by Holstein dairy cows during lying-down movements in an open space and in a free stall. Cows (n=5, mean parity 3.2 +/- 1.0, body weight=607 +/- 21 kg) used up to 300 cm of longitudinal space when lying down, more than is typically provided by current industry recommendations for stall length. Cows used up to 109 cm of lateral space (180% of hip width), an estimate that is within current recommendations for stall width. During the lying-down movement, maximal lateral displacements at the hip occurred in two vertical zones: one between 95 and 135 cm, and the second less than 50 cm above the lying surface. Maximal longitudinal displacements of the nose were clustered 10 to 30 cm above the surface. These heights should be taken into account when designing and positioning stall partitions. Maximum instantaneous velocity of body markers approached 220 cm/s, indicating that cows can contact inappropriately placed stall partitions and the lying surface with considerable force. Kinematic techniques are promising ways of assessing spatial requirements of cattle to improve stall design. Further work is required to assess a wider range of cow sizes and stall configurations.

Cost-effectiveness of flexible intensive insulin management to enable dietary freedom in people with Type 1 diabetes in the UK

AIMS

To determine the cost-effectiveness of a structured treatment and teaching programme (STTP) combining dietary freedom with insulin adjustment for Type 1 diabetes.

METHODS

Incremental cost-effectiveness analysis based on effectiveness data from three RCTs in Germany, Austria, and Dose Adjustment for Normal Eating (DAFNE) in the UK, to model the long-term microvascular complications of Type 1 diabetes.

RESULTS

The STTP approach yields effectiveness gains at a lower cost compared with current standard practice for treatment of Type 1 diabetes. STTPs are likely to save 0.05 life years, yield 0.12 EuroQol 5 dimensions (EQ-5D) and 0.09 visual analogue scale (VAS) incremental quality-adjusted life years, and save approximately pound 2200 per patient treated discounted over 10 years.

CONCLUSIONS

Introducing STTPs as standard treatment for people with Type 1 diabetes in the UK may help to achieve the primary goal of the National Service Framework (NSF) for Diabetes by enabling individuals to manage their own lifestyle and condition. In doing so it could save valuable resources for the NHS and yield important morbidity and mortality gains.

Second-generation microstimulator

The first-generation injectable microstimulator was glass encased with an external tantalum capacitor electrode. This second-generation device uses a hermetically sealed ceramic case with platinum electrodes. Zener diodes protect the electronics from defibrillation shocks and from electrostatic discharge. The capacitor is sealed inside the case so that it cannot be inadvertently damaged by surgical instruments. This microstimulator, referred to as BION, is the main component of a 255-channel wireless stimulating system. BION devices have been implanted in rats for periods of up to 5 months. Results show benign tissue reactions resulting in identical encapsulation around BION and controls. Stimulation threshold levels did not change significantly over time and ranged between 0.81 to 1.35 mA for all the animals at a 60 micros pulse width. All of the tests performed to date indicate that the BION is safe and effective for long-term human implant. We have elected to develop BION applications by seeking collaboration with the research community through our BION Technology Partnership.

Physiotherapy following cardiac surgery: is it necessary during the intubation period?

This randomised controlled clinical trial investigated whether physiotherapy during the period of mechanical ventilation following cardiac surgery influenced subject outcomes. Two hundred and thirty-six subjects admitted to the intensive care unit (ICU) following elective or semi-urgent cardiac surgery were randomised to either a treatment group, which received physiotherapy during the intubated phase, or a control group where physiotherapy was commenced only once the subject was extubated. No significant differences between the two groups were detected for length of intubation period, length of ICU stay, length of hospital stay, maximal daily incentive spirometry values or the incidence of post-operative pulmonary complications. For individuals following routine uncomplicated cardiac surgery, the provision of physiotherapy interventions during the post-operative intubation period does not improve outcomes.

Carcinoma of the lung in three brothers and two sisters

Documentation of familial aggregation of five siblings with lung cancer is presented. Lung cancer was not observed in their parents nor among their children, which is consistent with the hypothesis of recessive inheritance, although strong environmental factors such as tobacco smoking may contribute to the development of lung cancer in such families.

Prenatal diagnosis for inborn errors of metabolism and haemoglobinopathies: the Montreal Children's Hospital experience

We reviewed all referrals for prenatal diagnosis for inborn errors of metabolism and haemoglobinopathies performed at the Montreal Children's Hospital Prenatal Diagnosis Centre/McGill University during the period 1990-1995; 92 procedures were performed for these indications (less than 1 per cent of all referrals for prenatal diagnosis). All prenatal diagnoses for haemoglobinopathies (n = 55) were exclusively DNA-based. The three most frequent referrals were for beta-thalassaemia, sickle cell anaemia, and Tay-Sachs disease, accounting for 68 per cent of cases; the other indications were predominantly for untreatable inborn errors of metabolism. Our unit maintains population-based carrier screening programmes in high schools for beta-thalassaemia and Tay-Sachs diseases. Carriers detected in these programmes accounted for the majority of referrals for these two conditions. This study indicates that carrier testing and screening for sickle cell anaemia may be also welcomed by at-risk groups in Quebec.

In vivo measurements of indwelling tracheo-oesophageal prostheses in alaryngeal speech

Over the last 5 years, detailed air pressure, flow and voice measurements have been made on indwelling tracheo-oesophageal speaking valves whilst inserted in patients, using specially designed apparatus. This study was set up to investigate the relationship between speech and in vivo parameters. In vivo pressure measurements were generally lower for Groningen low resistance than Groningen high resistance, while flow and voice measurements were higher. A plot of opening pressure against pressure at maximum flow for all valves suggested a straight line relationship. A graph of maximum voice against composite parameter score for all valves showed a cluster of points between the composite score of 0-15. The advances in knowledge about these valves should be of use in the design of improved valves.

Speech assessment of patients using three types of indwelling tracheo-oesophageal voice prostheses

A multidisciplinary prospective study compared speech acceptability between three types of indwelling tracheo-oesophageal voice prostheses. Twenty male laryngectomees took part over five years, using 42 prostheses. Speech was assessed on a discrete scale by trained and untrained personnel. The majority scored in the mid-range for each assessor. The kappa coefficient was used to test similarity between assessors, and for all pairings agreement was significant (p < 0.05). The speech and language therapist tended to give higher scores and the patient lower. A relationship was found between patients' ages categorized by decade and the surgeon's score alone. This relationship held for Groningen high resistance and Provox prostheses individually too (p < 0.05). The untrained assessed similarly to the professionals--humans are all voice listeners. The analysis suggests surgeons find tracheo-oesophageal speech in older patients better than in younger ones; or make more allowances for the elderly. There was a trend for Provox prostheses to produce the best scores.

New method for stem cell quantification: applications to the management of peripheral blood stem cell transplantation

A dramatic increase in peripheral blood stem cells (PBSC) is observed after high-dose chemotherapy followed by haematopoietic growth factors. The degree of mobilisation of PBSC is quantified by the level of clonogenic cells detected by CFU assays (CFU-GM or CFU-GEMM) or CD34+ cell determination. Working under the hypothesis that, in peripheral blood, mononuclear cells in DNA synthesis (MCDS) are proliferating stem cells, we decided to detect these cells by flow cytometric measurement of their DNA content. The relations between the number of MCDS and well-known haematopoietic progenitor indicators such as CFU-GM or CD34+ cells were analysed. We studied the kinetics of recruitment of PBSC in cancer patients, treated with rmeHuG-CSF following VP-16 cytoxan chemotherapy, until the first day of leukapheresis. For the 31 patients studied the individual curves of peripheral MCDS and CFU-GM reconstitutions showed identical profiles and a good correlation was noted between the numbers of peripheral MCDS and CFU-GM (r = 0.73). In the leukapheresis product, the predictive value of MCDS was equivalent to CFU-GM for PBSC quantification (r = 0.70). In conclusion, MCDS analysis by flow cytometry provides reliable results and appears to be an alternative to CFU-GM assay or CD34+ cell determination for PBSC quantification.

Cervical epithelial abnormalities among women with vulval warts-no more common than among controls

Eighty-four women with vulval warts and 46 controls were examined for cervical epithelial abnormalities by cytology and colposcopy. The prevalence of colposcopically detected abnormalities was the same in the two groups. Minor cytologic abnormalities (less than moderate dyskaryosis) were more common among women with warts than among controls. It is concluded that women with vulval warts are no more likely than controls to have evidence of cervical epithelial abnormalities. These findings are discussed in the light of apparently contradictory findings by other workers.

Taking cervical smears in departments of genitourinary medicine

The smear taking practices of departments of genitourinary medicine were investigated by telephone inquiry. Departments seem to be broadly and equally divided into those where the smear is taken before the cervix is wiped or endocervical specimens are taken for microbiology, and those where the smear is taken afterwards. In the unit at Guy's Hospital we compared cervical smears taken in both of these sequences and concluded that, to diagnose more cases of premalignant cervical disease, smears should be taken before any other cervical samples.

Neuromuscular electrical stimulation for the head-injured patient

Recent research has shown that electrical stimulation is effective in treatment programs designed to maintain or gain range of motion, to facilitate voluntary motor control, and to strengthen muscles weakened by disuse. All of these treatment goals are relevant to the head-injured patient who frequently demonstrates profound disuse atrophy, joint contractures with excessive muscle tone, and decreased voluntary motor capabilities. As the cognitive status of the head-injured patient improves, electrical stimulation can be incorporated into traditional treatment programs to enhance their effectiveness. This article discusses using neuromuscular electrical stimulation with programs aimed at managing contractures, reducing spasticity, and facilitating voluntary motion. The limitations of electrical stimulation in the head-injured patient population are addressed.

Results of Mayo lung project: an interim report

Screening for lung cancer by chest roentgenography and sputum cytology can be conducted by mail. Detection, localization, and treatment of early presymptomatic lesions are possible. The initial prevalence of lung cancer in men older than age 45 years who were heavy smokers was almost 1%. Rescreening at 4-monthly intervals detected 4.7 new cases of lung cancer per 1,000 subjects per year. Three times as many postsurgical stage I lesions were detected in the screened group as in the control group. Although survival seems to have been improved by screening, mortality from lung cancer is not yet significantly different in the 4-monthly surveillance and control groups. Longer follow-up is necessary for determination of the ultimate usefulness of screening.