Comparison of different methods for thin section EM analysis of Mycobacterium smegmatis

Bacteria are generally difficult specimens to prepare for conventional resin section electron microscopy and mycobacteria, with their thick and complex cell envelope layers being especially prone to artefacts. Here we made a systematic comparison of different methods for preparing Mycobacterium smegmatis for thin section electron microscopy analysis. These methods were: (1) conventional preparation by fixatives and epoxy resins at ambient temperature. (2) Tokuyasu cryo-section of chemically fixed bacteria. (3) rapid freezing followed by freeze substitution and embedding in epoxy resin at room temperature or (4) combined with Lowicryl HM20 embedding and ultraviolet (UV) polymerization at low temperature and (5) CEMOVIS, or cryo electron microscopy of vitreous sections. The best preservation of bacteria was obtained with the cryo electron microscopy of vitreous sections method, as expected, especially with respect to the preservation of the cell envelope and lipid bodies. By comparison with cryo electron microscopy of vitreous sections both the conventional and Tokuyasu methods produced different, undesirable artefacts. The two different types of freeze-substitution protocols showed variable preservation of the cell envelope but gave acceptable preservation of the cytoplasm, but not lipid bodies, and bacterial DNA. In conclusion although cryo electron microscopy of vitreous sections must be considered the 'gold standard' among sectioning methods for electron microscopy, because it avoids solvents and stains, the use of optimally prepared freeze substitution also offers some advantages for ultrastructural analysis of bacteria.

Farming Systems and Resilience Building in a Changing Climate On-Farm Comparisons of Organic and Conventional Cocoa Cultivation in Alto Beni, Bolivia

Resilience research has been applied to socioeconomic as well as for agroecological studies in the last 20 years. It provides a conceptual and methodological approach for a better understanding of interrelations between the performance of ecological and social systems. In the research area Alto Beni, Bolivia, the production of cocoa (Theobroma cacao L.), is one of the main sources of income. Farmers in the region have formed producers’ associations to enhance organic cocoa cultivation and obtain fair prices since the 1980s. In cooperation with the long-term system comparisons by the Research Institute of Organic Agriculture (FiBL) in Alto Beni, aspects of the field trial are applied for the use in on-farm research: a comparison of soil fertility, biomass and crop diversity is combined with qualitative interviews and participatory observation methods. Fieldwork is carried out together with Bolivian students through the Swiss KFPE-programme Echanges Universitaires. For the system comparisons, four different land-use types were classified according to their ecological complexity during a preliminary study in 2009: successional agroforestry systems, simple agroforestry systems (both organically managed and certified), traditional systems and conventional monocultures. The study focuses on interrelations between different ways of cocoa cultivation, livelihoods and the related socio-cultural rationales behind them. In particular this second aspect is innovative as it allows to broaden the biophysical perspective to a more comprehensive evaluation with socio-ecological aspects thereby increasing the relevance of the agronomic field studies for development policy and practice. Moreover, such a socio-ecological baseline allows to assess the potential of organic agriculture regarding resilience-building face to socio-environmental stress factors. Among others, the results of the pre-study illustrate local farmers’ perceptions of climate change and the consequences for the different crop-systems: all interviewees mentioned rising temperatures and/or an extended dry season as negative impacts more with regard to their own working conditions than to their crops. This was the case in particular for conventional monocultures and in plots where slash-and-burn cultivation was practised whereas for organic agroforestry systems the advantage of working in the shade was stressed indicating that their relevance rises in the context of climate change.

[Historical review and future orientations of the conventional vascular microanastomoses]

Microvascular surgery has become an important method for reconstructing surgical defects due to trauma, tumors or after burn. The most important factor for successful free flap transfer is a well-executed anastomosis. The time needed to perform the anastomosis and the failure rate are not negligible despite the high level of operator's experience. During the history, many alternatives were tried to help the microsurgeon and to reduce the complications. A Medline literature search was performed to find articles dealing with non-suture methods of microvascular anastomosis. Many historical books were also included. The non-suture techniques can be divided into four groups based on the used mechanism of sutures: double intubation including tubes and stents, intubation-eversion including simple rings, double eversion including staples and double rings, and wall adjustement with adhesives or laser. All these techniques were able to produce a faster and easier microvascular anastomosis. Nevertheless, disadvantages of the suturless techniques include toxicity, high cost, leakage or aneurysm formation. More refinement is needed before their widespread adoption. Thus, laser-assisted microvascular anastomosis using 1,9 μm diode laser appeared to be a safe and reliable help for the microsurgeon and may be further developed in the near future.

Evaluation of high-definition and conventional oscillometric blood pressure measurement in anaesthetised dogs using ACVIM guidelines

OBJECTIVES: To evaluate high-definition and conventional oscillometry in comparison with direct blood pressure measurements in anaesthetised dogs. METHODS: Eight simultaneous readings for systolic, diastolic and mean pressure were obtained directly and with each of two devices in nine anaesthetised dogs. Measurement procedure and validation were based on the 2007 ACVIM guidelines. RESULTS: Sixty-three simultaneous readings were evaluated for each device and direct measurements. The mean differences (bias) to direct values were within 10 mmHg for both devices although bias for systolic and diastolic blood pressures was higher for Memodiagnostic. The standard deviations of differences (precision) were within 15 mmHg for Dinamap but exceeded for Memodiagnostic. Correlation coefficients were higher for Dinamap than Memodiagnostic but both failed to reach a correlation of 0.9. Over 50% of values lay within 10 mmHg of direct measures for both devices, but this percentage was greater for Dinamap than Memodiagnostic. Over 80% of values lay within 20 mmHg of direct measures for Dinamap but not for Memodiagnostic. CLINICAL SIGNIFICANCE: Both devices failed to meet ACVIM guideline validation. However, Dinamap only failed with regards to correlation. Memodiagnostic failed on several requirements, and based on poor correlation, accuracy and precision, this device cannot be currently recommended for dogs under anaesthesia.

Complementary and conventional medicine in Switzerland: comparing characteristics of general practitioners

OBJECTIVES: Do structural characteristics of general practitioners (GPs) who practice complementary medicine (CAM) differ from those GPs who do not? Assessed characteristics included experience and professional integration of general practitioners (GPs), workload, medical activities, and personal and technical resources of practices. The investigated CAM disciplines were anthroposophic medicine, homoeopathy, traditional Chinese medicine, neural therapy and herbal medicine. MATERIAL AND METHODS: We designed a cross-sectional study with convenience and stratified samples of GPs providing conventional (COM) and/or complementary primary care in Switzerland. The samples were taken from the database of the Swiss medical association (FMH) and from CAM societies. Data were collected using a postal questionnaire. RESULTS: Of the 650 practitioners who were included in the study, 191 were COM, 167 noncertified CAM and 292 certified CAM physicians. The proportion of females was higher in the population of CAM physicians. Gender-adjusted age did not differ between CAM and COM physicians. Nearly twice as many CAM physicians work part-time. Differences were also seen for the majority of structural characteristics such as qualification of physicians, type of practice, type of staff, and presence of technical equipment. CONCLUSION: The study results show that structural characteristics of primary health care do differ between CAM and COM practitioners. We assumed that the activities of GPs are defined essentially by analyzed structures. The results are to be considered for evaluations in primary health care, particularly when quality of health care is assessed.

Physicians' philosophy of care: a comparison of complementary and conventional medicine

BACKGROUND: This project is part of an evaluation of complementary and alternative medicine (CAM) aimed at providing a scientific basis for the Swiss Government to include 5 CAM methods in basic health coverage: anthroposophic medicine, homeopathy, neural therapy, phytotherapy and Traditional Chinese Medicine (TCM). OBJECTIVES: The objective was to explore the philosophy of care (convictions and values, priorities in medical activity, motivation for CAM, criteria for the practice of CAM, limits of the used methods) of conventional and CAM general practitioners (GPs) and to determine differences between both groups. MATERIALS AND METHODS: This study was a cross-sectional survey of a representative sample of 623 GPs who provide complementary or conventional primary care. A mailed questionnaire with open-ended questions focusing on the philosophy of care was used for data collection. An appropriate methodology using a combination of quantitative and qualitative approaches was developed. RESULTS: Significant differences between both groups include philosophy of care (holistic versus positivistic approaches), motivation for CAM (intrinsic versus extrinsic) and priorities in medical activity. Both groups seem to be aware of limitations of the therapeutic methods used. The study reveals that conventional physicians are also using complementary medicine. DISCUSSION: Our study provides a wealth of data documenting several aspects of physicians' philosophy of care as well as differences and similarities between conventional and complementary care. Implications of the study with regard to quality of care as well as ethical and health policy issues should be investigated further.

Health status and health care utilisation of patients in complementary and conventional primary care in Switzerland--an observational study

BACKGROUND: The study is part of a nationwide evaluation of complementary and alternative medicine (CAM) in primary care in Switzerland. OBJECTIVES: Patient health status with respect to demographic attributes such as gender, age, and health care utilisation pattern was studied and compared with conventional primary care. METHODS: The study was performed as a cross-sectional survey including 11932 adult patients seeking complementary or conventional primary care. Patients were asked to document their self-perceived health status by completing a questionnaire in the waiting room. Physicians were performing conventional medicine and/or various forms of complementary primary care such as homeopathy, anthroposophic medicine, neural therapy, herbal medicine, or traditional Chinese medicine. Additional information on patient demographics and yearly consultation rates for participating physicians was obtained from the data pool of all Swiss health insurers. These data were used to confirm the survey results. RESULTS: We observed considerable and significant differences in demographic attributes of patients seeking complementary and conventional care. Patients seeking complementary care documented longer lasting and more severe main health problems than patients in conventional care. The number of previous physician visits differed between patient groups, which indicates higher consumption of medical resources by CAM patients. CONCLUSIONS: The study supports the hypothesis of differences in socio-demographic and behavioural attributes of patients seeking conventional medicine or CAM in primary care. The study provides empirical evidence that CAM users are requiring more physician-based medical services in primary care than users of conventional medicine.

THA performed using conventional and navigated tissue-preserving techniques

Less invasive methods of performing total hip arthroplasty have been considered controversial after increased complication rates and component malpositioning were reported. A new method of performing total hip arthroplasty through an incision in the superior capsule, posterior to the abductors and anterior to the posterior capsule, was developed with the aim of producing a technique that maintained the joint stability of the transgluteal exposure and the rapid abductor recovery of the posterior exposure. We assessed the recovery and complications of this technique performed with surgical navigation. The study group was compared with similar subjects who had conventional total hip arthroplasty, without surgical navigation, using the transgluteal exposure. There were 185 consecutive total hip arthroplasties in the study group and 189 nonconsecutive historical total hip arthroplasties in the control group. The two groups were controlled for complexity and had no differences in body mass index, gender, diagnosis, operative side, bilateral operations, and previous surgeries. Patients were evaluated for clinical recovery and perioperative complications at 9 and 24 weeks. The study group recovered faster at both followup examinations. The study group had fewer perioperative and postoperative complications compared with the control group. Accuracy of component positioning was not compromised compared to the control group. Less invasive surgery with the philosophy of maximally preserving the abductors, posterior capsule, and short rotators may result in a safer operation with faster recovery than traditional techniques.

[Conventional vs minimally invasive total hip arthroplasty. A prospective study of rehabilitation and complications]

BACKGROUND: In a prospective, nonrandomized study the outcome in terms of rehabilitation and complications of total hip arthroplasty (THA) through a superior capsulotomy exposure (study group) was compared to THA performed through a direct lateral exposure (control group). PATIENTS AND METHODS: The study group (106 THA) and the control group (107 THA) were controlled for complexity and had no significant differences in age, sex, diagnosis, or body mass index. RESULTS: The study group had improved recovery at 6 weeks after surgery which was statistically significant (p<0.001). In addition, the study group had a lower incidence of perioperative complications. CONCLUSION: The current study demonstrates the potential that less-invasive surgical techniques with the philosophy of maximally preserving the abductors, posterior capsule, and short rotators may result in a safer operation with an accelerated recovery.

Performance of a conventional sealant and a flowable composite on minimally invasive prepared fissures

Three different fissure preparation procedures were tested and compared to the non-invasive approach using a conventional unfilled sealant and a flowable composite. Eighty permanent molars were selected and divided into 4 groups of 20 teeth each. All the teeth were split into 2 halves, and the exposed fissures were photographed under a microscope (35x) before and after being prepared using the following methods: (I) Er:YAG laser (KEY Laser, KaVo) 600 mJ pulse energy, 6 Hz; (II) diamond bur; (III) Er: YAG laser (KEY Laser, KaVo) 200 mJ pulse energy, 4 Hz; (IV) Control group: Powder jet cleaner (Prophyflex, KaVo, Germany). The pre-and postimages were superimposed in order to evaluate the amount of hard tissue removed. Ten teeth in each group were then acid etched and sealed with an unfilled sealant (Delton opaque, Dentsply), while the remaining 10 teeth were acid etched, primed and bonded (Prime ; Bond NT, Dentsply) and sealed with a flowable composite (X-flow, DeTrey, Dentsply). Material penetration and microleakage were evaluated after thermocycling (5000 cycles) and staining with methylene blue 5%. ANOVA and Mann-Whitney tests were applied for statistical analysis. The laser 600 mJ and bur eliminated the greatest amount of hard tissue. The control teeth presented the least microleakage when sealed with Delton or X-flow. A correlation between material penetration and microleakage could not be statistically confirmed. Mechanical preparation prior to fissure sealing did not enhance the final performance of the sealant.

Performance of four dentine excavation methods in deciduous teeth

This in vitro study aimed to assess the speed and caries removal effectiveness of four different new and conventional dentine excavation methods. Eighty deciduous molars were assigned to four groups. Teeth were sectioned longitudinally through the lesion centre. Images of one half per tooth were captured by light microscope and confocal laser scanning microscopy (CLSM) to assess the caries extension. The halves were then reassembled and caries removed using round carbide bur (group 1), Er:YAG laser (group 2), hand excavator (group 3) and a polymer bur (group 4). The time needed for the whole excavation in each tooth was registered. After excavation, the halves were photographed by light microscope. Caries extension obtained from CLSM images were superimposed on the post-excavation images, allowing comparison between caries extension and removal. The regions where caries and preparation limits coincided, as well as the areas of over- and underpreparation, were measured. Steel bur was the fastest method, followed by the polymer bur, hand excavator and laser. Steel bur exhibited also the largest overpreparation area, followed by laser, hand excavator and polymer bur. The largest underpreparation area was found using polymer bur, followed by laser, hand excavator and steel bur. Hand excavator presented the longest coincidence line, followed by polymer and steel burs and laser. Overall, hand excavator seemed to be the most suitable method for carious dentine excavation in deciduous teeth, combining good excavation time with effective caries removal.

Diagnostic accuracy of 64-slice computed tomography for detecting angiographically significant coronary artery stenosis in an unselected consecutive patient population: comparison with conventional invasive angiography

BACKGROUND: Multislice computed tomography (MSCT) is a promising noninvasive method of detecting coronary artery disease (CAD). However, most data have been obtained in selected series of patients. The purpose of the present study was to investigate the accuracy of 64-slice MSCT (64 MSCT) in daily practice, without any patient selection. METHODS AND RESULTS: Using 64-slice MSCT coronary angiography (CTA), 69 consecutive patients, 39 (57%) of whom had previously undergone stent implantation, were evaluated. The mean heart rate during scan was 72 beats/min, scan time 13.6 s and the amount of contrast media 72 mL. The mean time span between invasive coronary angiography (ICAG) and CTA was 6 days. Significant stenosis was defined as a diameter reduction of > 50%. Of 966 segments, 884 (92%) were assessable. Compared with ICAG, the sensitivity of CTA to diagnose significant stenosis was 90%, specificity 94%, positive predictive value (PPV) 89% and negative predictive value (NPV) 95%. With regard to 58 stented lesions, the sensitivity, specificity, PPV and NPV were 93%, 96%, 87% and 98%, respectively. On the patient-based analysis, the sensitivity, specificity, PPV and NPV of CTA to detect CAD were 98%, 86%, 98% and 86%, respectively. Eighty-two (8%) segments were not assessable because of irregular rhythm, calcification or tachycardia. CONCLUSION: Sixty-four-MSCT has a high accuracy for the detection of significant CAD in an unselected patient population and therefore can be considered as a valuable noninvasive technique.

Placebo-controlled trials of Chinese herbal medicine and conventional medicine - comparative study

BACKGROUND: Chinese herbal medicine (CHM) is increasingly used in the West, but the evidence on its effectiveness is a matter of debate. We compared the characteristics, study quality and results of clinical trials of CHM and conventional medicine. METHODS: Comparative study of placebo-controlled trials of CHM and conventional medicine. Eleven bibliographic databases and searches by hand of 48 Chinese-language journals. Conventional medicine trials matched for condition and type of outcome were randomly selected from the Cochrane Controlled Trials Register (issue 1, 2003). Trials described as double-blind, with adequate generation of allocation sequence and adequate concealment of allocation, were assumed to be of high quality. Data were analysed using funnel plots and multivariable meta-regression models. RESULTS: 136 CHM trials (119 published in Chinese, 17 published in English) and 136 matched conventional medicine trials (125 published in English) were analysed. The quality of Chinese-language CHM trials tended to be lower than that of English-language CHM trials and conventional medicine trials. Three (2%) CHM trials and 10 (7%) conventional medicine trials were of high quality. In all groups, smaller trials showed more beneficial treatment effects than larger trials. CHM trials published in Chinese showed considerably larger effects than CHM trials published in English (adjusted ratio of ORs 0.29, 95% confidence intervals 0.17-0.52). CONCLUSIONS: Biases are present both in placebo-controlled trials of CHM and conventional medicine, but may be most pronounced in CHM trials published in Chinese-language journals. Only few CHM trials of adequate methodology exist and the effectiveness of CHM therefore remains poorly documented.

Patients motives for choosing a physician: Comparison between conventional and complementary medicine in Swiss primary care

Background The study is part of a nationwide evaluation of complementary and alternative medicine (CAM) in primary care in Switzerland. The Objective was to identify patients' expectations and reasons governing the choice of complementary medicine compared with conventional primary care (CONV). Methods The data were derived from the PEK study (Programm Evaluation Komplementärmedizin), which was conducted in 2002–2003 with 7879 adult patients and parents of 1291 underage patients, seeking either complementary (CAM) or conventional (CONV) primary care. The study was performed as a cross-sectional survey. The respondents were asked to document their (or their children's) self-perceived health status, reasons governing their choice, and treatment expectations. Physicians were practicing conventional medicine and/or complementary methods (homeopathy, anthroposophic medicine, neural therapy, and traditional Chinese medicine). Reasons governing the choice of physician were evaluated on the basis of a three-part classification (physician-related, procedure-related, and pragmatic/other reasons) Results and Discussion Patients seeing CAM physicians tend to be younger and more often female. CAM patients referred to procedure-related reasons more frequently, whereas pragmatic reasons dominated among CONV patients. CAM respondents expected fewer adverse side effects compared to conventional care patients. Conclusion The majority of alternative medicine users appear to have chosen CAM mainly because they wish to undergo a certain procedure; additional reasons include desire for more comprehensive treatment, and expectation of fewer side-effects.

Comparison of amplification methods for transcriptomic analyses of low abundance prokaryotic RNA sources

Microarrays have established as instrumental for bacterial detection, identification, and genotyping as well as for transcriptomic studies. For gene expression analyses using limited numbers of bacteria (derived from in vivo or ex vivo origin, for example), RNA amplification is often required prior to labeling and hybridization onto microarrays. Evaluation of the fidelity of the amplification methods is crucial for the robustness and reproducibility of microarray results. We report here the first utilization of random primers and the highly processive Phi29 phage polymerase to amplify material for transcription profiling analyses. We compared two commercial amplification methods (GenomiPhi and MessageAmp kits) with direct reverse-transcription as the reference method, focusing on the robustness of mRNA quantification using either microarrays or quantitative RT-PCR. Both amplification methods using either poly-A tailing followed by in vitro transcription, or direct strand displacement polymerase, showed appreciable linearity. Strand displacement technique was particularly affordable compared to in vitro transcription-based (IVT) amplification methods and consisted in a single tube reaction leading to high amplification yields. Real-time measurements using low-, medium-, and highly expressed genes revealed that this simple method provided linear amplification with equivalent results in terms of relative messenger abundance as those obtained by conventional direct reverse-transcription.