Chronic outcomes of leadless vs transvenous single chamber ventricular pacemakers in high-risk subgroups

Background

The Micra leadless pacemaker (LP-VVI) has been shown to have lower chronic complications and device-related reinterventions compared to transvenous ventricular pacemakers (TV-VVI) in a large, real-world population. This study compares the complication and reintervention rate in subgroups with comorbidities associated with higher risk of pacemaker complications and hypothesized to benefit from leadless pacing.

Methods

The longitudinal Micra Coverage with Evidence Development (CED) Study compared the outcomes of Medicare patients receiving LP-VVI to those receiving a TV-VVI in the US. Patients in the Micra CED study were included in this study if they had a diagnosis of chronic kidney disease Stages 4–5 (CKD45), end-stage renal disease (ESRD), malignancy, diabetes, tricuspid valve disease (TVD), or chronic obstructive pulmonary disease (COPD) on any administrative claim in the 12 months prior to pacemaker implant. A pre-specified set of complications and system reinterventions were identified using the relevant diagnosis and procedure codes. Adjusted and unadjusted Fine-Gray competing risks models were used to compare reinterventions and complications between LP-VVI and TV-VVI patients within each subgroup. All results were adjusted for multiple comparisons using a Bonferroni correction. An ad-hoc comparison of a composite endpoint of select reinterventions (system replacement, removal, revision, and lead reinterventions) and device complications was also conducted.

Results

The sample size of patients in each subgroup ranged from 2,032 patients with ESRD to 11,936 patients with diabetes. The percent of LP-VVI patients in each subgroup ranged from 44.0 in the TVD subgroup to 74.9 in the ESRD subgroup. Compared to patients implanted with a TV-VVI, patients with a LP-VVI with malignancy, diabetes, TVD, and COPD had significantly fewer complications (Table 1; Malignancy, HR 0.68, [0.48–0.95]; Diabetes, HR 0.69, [0.53–0.89]; TVD, HR 0.60 [0.44–0.82]; COPD, HR 0.73, [0.55–0.98]). LP-VVI patients with diabetes, TVD, and COPD also had lower rates of reintervention (Table; Diabetes, HR 0.58, [0.37–0.89]; TVD, HR 0.46 [0.28–0.76]; COPD, HR 0.51, [0.29–0.90]). LP-VVI patients with malignancy, diabetes, TVD, and COPD had lower rates of the combined endpoint of device complications and select reinterventions (Table; Malignancy, HR 0.52, [0.32–0.83]; Diabetes, HR 0.52, [0.35–0.77]; TVD, HR 0.44 [0.28–0.70]; COPD, HR 0.55, [0.34–0.89]).

Conclusions

In a real-world study of US Medicare patients, the leadless pacemaker was associated with lower rates of chronic complications and reinterventions at 2 years compared with TV-VVI pacing in several high-risk subgroups.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Medtronic

Streptococcus dysgalactiae subspecies dysgalactiae in Norwegian bovine dairy herds: Risk factors, sources, and genomic diversity

Despite the importance of Streptococcus dysgalactiae ssp. dysgalactiae (SDSD) as an udder pathogen, the reservoir and epidemiological characteristics of this bacterium are largely unexplored. The aims of this study were to investigate risk factors for SDSD intramammary infections (SDSD-IMI) in Norwegian bovine dairy herds, identify sources of SDSD on animals and in the environment, and elucidate the genetic diversity of SDSD isolates. Data from herd recordings and a questionnaire were used to investigate herd-level risk factors for SDSD-IMI in 359 freestall dairy herds. Seven herds with a suspected high prevalence of SDSD-IMI were visited to sample extramammary sources (e.g., skin, wounds, mucous membranes, and freestall environment). Bacterial isolates were whole-genome sequenced to investigate the distribution of SDSD genotypes within herds and to assess the phylogenetic relationship between SDSD isolates from 27 herds across Norway. Risk factors for high incidence of SDSD-IMI in freestall dairy herds were related to housing, including closed flooring in alleys and rubber mats in cubicle bases. Parlor milking was also a risk factor compared with automatic milking systems. From herd visits, a considerable proportion of extramammary samples were SDSD positive, particularly from wounds and skin of the animals and the cubicle bases. Samples from mucous surfaces (nostrils, rectum, and vagina) and water troughs were least frequently positive. Eight multilocus sequence types (ST) were identified among the sequenced isolates from 27 herds, and phylogenetic analyses revealed 8 clades corresponding to ST. No significant association was identified between sampling site (milk, body sites, and environment) and ST. In 4 of 6 herds from which 5 or more isolates were available, one ST dominated and was found in milk and extramammary samples. One ST (ST453) was found in 15 of 27 herds, which implies that this is a widely distributed and possibly a bovine-adapted strain. Findings in this study suggest that SDSD is a cow-adapted opportunist with potential for contagious transmission, and that the freestall environment is likely to play a role in transmission between cows.

Uncertainty and Bias in Global to Regional Scale Assessments of Current and Future Coastal Flood Risk

This study provides a literature-based comparative assessment of uncertainties and biases in global to world-regional scale assessments of current and future coastal flood risks, considering mean and extreme sea-level hazards, the propagation of these into the floodplain, people and coastal assets exposed, and their vulnerability. Globally, by far the largest bias is introduced by not considering human adaptation, which can lead to an overestimation of coastal flood risk in 2100 by up to factor 1300. But even when considering adaptation, uncertainties in how coastal societies will adapt to sea-level rise dominate with a factor of up to 27 all other uncertainties. Other large uncertainties that have been quantified globally are associated with socio-economic development (factors 2.3-5.8), digital elevation data (factors 1.2-3.8), ice sheet models (factor 1.6-3.8) and greenhouse gas emissions (factors 1.6-2.1). Local uncertainties that stand out but have not been quantified globally, relate to depth-damage functions, defense failure mechanisms, surge and wave heights in areas affected by tropical cyclones (in particular for large return periods), as well as nearshore interactions between mean sea-levels, storm surges, tides and waves. Advancing the state-of-the-art requires analyzing and reporting more comprehensively on underlying uncertainties, including those in data, methods and adaptation scenarios. Epistemic uncertainties in digital elevation, coastal protection levels and depth-damage functions would be best reduced through open community-based efforts, in which many scholars work together in collecting and validating these data.

Patients with recurrent syncope and implantable loop recorder exhibit better survival than the control group without implantable loop recorder

Introduction

In 30% of patients with syncope, the underlying cause remains unexplained after clinical investigations. Unexplained syncope tends to recur, significantly impacting patients' quality of life of patients and mortality. Thus, there is a need for timely and more accurate diagnosis to initiate treatment. Dedicated care pathways are recommended by ESC guidelines.

Purpose

Patients with recurrent syncope were followed over time and patient outcomes with ILR were compared to patients with the same syncope burden, age, gender and mortality risk score who did not receive an ILR.

Method

A representative database of 4.9 million patients insured by German company statuary health insurances (BKK) was analysed over a time period of 10 years, 2007–17. Patients with recurrent syncope (two times ICD-10 GM diagnosis codes R55), age between 45–84 and no diagnosis code for the syncope were included in the analysis and followed for at least 2 years. Patients with ILR were matched to patients without ILR based on age, gender and Charlson Comorbidity index (CCI) using mahalanobis distances. The index event was the device implant in the ILR group and the second syncope event in the control group. Life expectancy, syncope hospitalisations, fall related injuries, health care costs, diagnoses and treatment rates were compared between the groups.

Results

A total of 412 patients with ILR for recurrent unexplained syncope were matched to the control group. Overall mean age was 68, mean was CCI 2.7, 42% were females. The risk of death was 2.35 times higher in the control group during follow up as shown in Figure 1 (p-value logrank test <0.0001). Cardiovascular related diagnosis and treatment rates were higher in the ILR group with 69% of patients having a cardiology diagnosis compared to 41% in the control group. Over a quarter (27%) of ILR patients received an implantable cardiac device compared to 5% in the control group. Ablation rates were 7% in the ILR group compared to 0% in the control group. Median health care costs were € 3,847 higher in the ILR group including the costs of the ILR implant, follow up and higher rates of cardiac treatments. These extra costs appear moderate given the substantially higher mortality risk in the control group.

Conclusion

This study of patients with recurrent unexplained syncope shows a remarkable difference in life expectancy in patients with ILR compared to a matched control group. Two large claim data analysis have recently shown higher rates of cardiovascular death as well as all-cause mortality in patients with unexplained syncope. A more vigilant cardiac workup might be needed to identify a possible underlying cardiac condition. Higher rates of cardiac device therapy in the ILR group were likely to play an important role for their better life expectancy. Cardiac therapies such as pacemakers, defibrillators and ablation have also been shown to significantly improve patients' quality of life.

Life Expectancy Comparison

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): The data analysis was funded by Medtronic

Stimulated plasmon polariton scattering

Plasmon and phonon polaritons of two-dimensional (2D) and van-der-Waals materials have recently gained substantial interest. Unfortunately, they are notoriously hard to observe in linear response because of their strong confinement, low frequency and longitudinal mode symmetry. Here, we propose an approach of harnessing nonlinear resonant scattering that we call stimulated plasmon polariton scattering (SPPS) in analogy to the opto-acoustic stimulated Brillouin scattering (SBS). We show that SPPS allows to excite, amplify and detect 2D plasmon and phonon polaritons all across the THz-range while requiring only optical components in the near-IR or visible range. We present a coupled-mode theory framework for SPPS and based on this find that SPPS power gains exceed the very top gains observed in on-chip SBS by at least an order of magnitude. This opens exciting possibilities to fundamental studies of 2D materials and will help closing the THz gap in spectroscopy and information technology.

Role of diffusive surface scattering in nonlocal plasmonics

The recent generalised nonlocal optical response (GNOR) theory for plasmonics is analysed, and its main input parameter, namely the complex hydrodynamic convection-diffusion constant, is quantified in terms of enhanced Landau damping due to diffusive surface scattering of electrons at the surface of the metal. GNOR has been successful in describing plasmon damping effects, in addition to the frequency shifts originating from induced-charge screening, through a phenomenological electron diffusion term implemented into the traditional hydrodynamic Drude model of nonlocal plasmonics. Nevertheless, its microscopic derivation and justification is still missing. Here we discuss how the inclusion of a diffusion-like term in standard hydrodynamics can serve as an efficient vehicle to describe Landau damping without resorting to computationally demanding quantum-mechanical calculations, and establish a direct link between this term and the Feibelman d parameter for the centroid of charge. Our approach provides a recipe to connect the phenomenological fundamental GNOR parameter to a frequency-dependent microscopic surface-response function. We therefore tackle one of the principal limitations of the model, and further elucidate its range of validity and limitations, thus facilitating its proper application in the framework of nonclassical plasmonics.

Lung cancer screening by low-dose CT among asbestos-exposed workers: first results of a pilot program

Background

Occupational asbestos exposure (OAE) is a risk factor for lung cancer (LC) and can cause malignant diseases decades after exposure. Lung cancer screening with low-dose computed tomography (LCS) in heavy smokers has shown LC-mortality reductions in two large trials. Recent guidelines advocate LCS in high-risk populations with OAE and additional smoking history.

Methods

A structured pilot program on LCS in three German regions has been implemented from 2014 to 2018. Eligibility criteria are: OAE ≥10 years starting before 1985 or diagnosis of OAE-related lung disease other than cancer, age ≥55 years and smoking history ≥30 pack years. Eligible persons are centrally invited for LCS on a voluntary basis in 12 months intervals. All persons willing to participate receive obligatory physician counselling before LCS. CT scans are performed according to a standardized protocol. The program provides technical quality assurance as well as independent double reading of all suspicious findings and of a random sample of all CT scans.

Results

Of 2715 and 1534 persons invited to first and second LCS, 1571 (57.9%) and 715 (46.6%) agreed to participate, respectively. Main reason for disagreement was principal refusal of LCS (15.5% in first and 22.2% in second LCS), whereas 8.5% and 6.9%, respectively, refused after counselling. Additionally, 12.9% and 5.7% did not respond at all. Effectively, 68.8% and 70.6% of those who initially agreed, received first and second LCS, respectively. Variations between regions were observed (range 61.0% to 79.8%). First preliminary outcome assessment shows detection rates of 0.019 and 0.011 in first and second LCS, respectively.

Conclusions

A substantial group of eligible persons with OAE participated in LCS after physician counselling. Participation remained stable over two screening rounds. First results show detection of LC in the expected range. The effectiveness of early detection of LC in OAE needs to be evaluated further.

Key messages

Participation over the first two screening rounds in structured lung cancer screening remained stable among eligible persons with OAE and smoking history who were counselled by physicians. Detection of lung cancer in a structured pilot screening program in three German regions seems to be within the range to be expected from previous research.

Stimulated Brillouin scattering in layered media: nanoscale enhancement of silicon

We report a theoretical study of stimulated Brillouin scattering (SBS) in general anisotropic media, incorporating the effects of both acoustic strain and local rotation. We apply our general theoretical framework to compute the SBS gain for layered media with periodic length scales smaller than all optical and acoustic wavelengths, where such composites behave like homogeneous anisotropic media. We predict that a layered medium composing nanometer-thin layers of silicon and As₂S₃ glass has a bulk SBS gain of 1.28×10^-9  W^-1 m. This is more than 500 times larger than that of silicon and almost double the gain of As₂S₃. The enhancement is due to a combination of roto-optic, photoelastic, and artificial photoelastic contributions in the composite structure.

Detection of thrombosis in microvessels with indocyanine green videoangiography

Atherosclerosis is a systemic condition that is responsible for many diseases, and becomes a problem in cases where plaques form at several sites. The formation of a thrombotic embolus may jeopardise vascular operations, including microvascular anastomoses in replantation procedures or free tissue transfers. A mobile imaging tool for the detection of thrombosis preoperatively or intraoperatively would be valuable. An intimal injury, simulating removal of atherosclerotic plaques, was made microsurgically in 60 rat aortas, and results were analysed macroscopically, histologically, and with intraoperative indocyanine green (ICG) videoangiography immediately postoperatively. The Spearman and Pearson correlation tests were used to compare the three techniques. The sensitivity and specificity of ICG videoangiography was calculated in relation to both macroscopic and histological results. Detection of thrombosis was possible in 25 cases, and in 18 cases no thrombosis was correctly diagnosed by all methods used. In 31 of 60 specimens formation of thrombus was detected histologically, and in 29 of 60 examinations it was detected clinically, which yielded a correlation of 93.5% between the two examinations. Macroscopic analysis correlated better with ICG videoangiography (sensitivity 86.2% and specificity 64.5%) than histological observations (sensitivity 80.6% and specificity 62.1%). There was a significant correlation among all comparisons (each p≤0.001) with correlation indexes of 0.94, 0.52, and 0.44 for macroscopic/histological, clinical/ICG videoangiographic, and ICG videoangiographic/histological results, respectively. Our results show that ICG videoangiography is an important method for the detection of formation of acute thrombi and may be an important tool in vascular procedures.

Biosecurity aspects of cattle production in Western Uganda, and associations with seroprevalence of brucellosis, salmonellosis and bovine viral diarrhoea

BACKGROUND

Many low-income countries have a human population with a high number of cattle owners depending on their livestock for food and income. Infectious diseases threaten the health and production of cattle, affecting both the farmers and their families as well as other actors in often informal value chains. Many infectious diseases can be prevented by good biosecurity. The objectives of this study were to describe herd management and biosecurity routines with potential impact on the prevalence of infectious diseases, and to estimate the burden of infectious diseases in Ugandan cattle herds, using the seroprevalence of three model infections.

RESULTS

Farmer interviews (n = 144) showed that biosecurity measures are rarely practised. Visitors' hand-wash was used by 14%, cleaning of boots or feet by 4 and 79% put new cattle directly into the herd. During the 12 months preceding the interviews, 51% of farmers had cattle that died and 31% had noticed abortions among their cows. Interestingly, 72% were satisfied with the health status of their cattle during the same time period. The prevalence (95% CI) of farms with at least one seropositive animal was 16.7% (11.0;23.8), 23.6% (16.9;31.4), and 53.4% (45.0;61.8) for brucella, salmonella and BVD, respectively. A poisson regression model suggested that having employees looking after the cattle, sharing pasture with other herds, and a higher number of dead cattle were associated with a herd being positive to an increasing number of the diseases. An additive bayesian network model with biosecurity variables and a variable for the number of diseases the herd was positive to resulted in three separate directed acyclic graphs which illustrate how herd characteristics can be grouped together. This model associated the smallest herd size with herds positive to a decreasing number of diseases and having fewer employees.

CONCLUSION

There is potential for improvement of biosecurity practices in Ugandan cattle production. Salmonella, brucella and BVD were prevalent in cattle herds in the study area and these infections are, to some extent, associated with farm management practices.

Stimulated Brillouin scattering enhancement in silicon inverse opal waveguides

Silicon is an ideal material for on-chip applications, however its poor acoustic properties limit its performance for important optoacoustic applications, particularly for stimulated Brillouin scattering (SBS). We theoretically show that silicon inverse opals exhibit a strongly improved acoustic performance that enhances the bulk SBS gain coefficient by more than two orders of magnitude. We also design a waveguide that incorporates silicon inverse opals and which has SBS gain values that are comparable with chalcogenide glass waveguides. This research opens new directions for opto-acoustic applications in on-chip material systems.

Metamaterial control of stimulated Brillouin scattering

Using full opto-acoustic numerical simulations, we demonstrate enhancement and suppression of the SBS gain in a metamaterial comprising a subwavelength cubic array of dielectric spheres suspended in a dielectric background material. We develop a general theoretical framework and present several numerical examples using technologically important materials. For As₂S₃ spheres in silicon, we achieve a gain enhancement of more than an order of magnitude compared to pure silicon and for GaAs spheres in silicon, full suppression is obtained. The gain for As₂S₃ glass can also be strongly suppressed by embedding silica spheres. The constituent terms of the gain coefficient are shown to depend in a complex way on the filling fraction. We find that electrostriction is the dominant effect behind the control of SBS in bulk media.

Power limits and a figure of merit for stimulated Brillouin scattering in the presence of third and fifth order loss

We derive a set of design guidelines and a figure of merit to aid the engineering process of on-chip waveguides for strong Stimulated Brillouin Scattering (SBS). To this end, we examine the impact of several types of loss on the total amplification of the Stokes wave that can be achieved via SBS. We account for linear loss and nonlinear loss of third order (two-photon absorption, 2PA) and fifth order, most notably 2PA-induced free carrier absorption (FCA). From this, we derive an upper bound for the output power of continuous-wave Brillouin-lasers and show that the optimal operating conditions and maximal realisable Stokes amplification of any given waveguide structure are determined by a dimensionless parameter ℱ involving the SBS-gain and all loss parameters. We provide simple expressions for optimal pump power, waveguide length and realisable amplification and demonstrate their utility in two example systems. Notably, we find that 2PA-induced FCA is a serious limitation to SBS in silicon and germanium for wavelengths shorter than 2200nm and 3600nm, respectively. In contrast, three-photon absorption is of no practical significance.

Formal selection rules for Brillouin scattering in integrated waveguides and structured fibers

We derive formal selection rules for Stimulated Brillouin Scattering (SBS) in structured waveguides. Using a group-theoretical approach, we show how the waveguide symmetry determines which optical and acoustic modes interact for both forward and backward SBS. We present a general framework for determining this interaction and give important examples for SBS in waveguides with rectangular, triangular and hexagonal symmetry. The important role played by degeneracy of the optical modes is illustrated. These selection rules are important for SBS-based device design and for a full understanding the physics of SBS in structured waveguides.

Germanium as a material for stimulated Brillouin scattering in the mid-infrared

In a theoretical design study, we propose buried waveguides made of germanium or alloys of germanium and other group-IV elements as a CMOS-compatible platform for robust, high-gain stimulated Brillouin scattering (SBS) applications in the mid-infrared regime. To this end, we present numerical calculations for backward-SBS at 4 μm in germanium waveguides that are buried in silicon nitride. Due to the strong photoelastic anisotropy of germanium, we investigate two different orientations of the germanium crystal with respect to the waveguide's propagation direction and find considerable differences. The acoustic wave equation is solved including crystal anisotropy; acoustic losses are computed from the acoustic mode patterns and previously published material parameters.

European proficiency study with control serum for the tumor marker CA 19-9 measured on different test systems

BACKGROUND

Reliable and precise CA 19-9 testing is required for the long-term follow-up of patients with pancreatic carcinoma during therapy. The aim of this longitudinal proficiency study was to evaluate the comparability, linearity, and precision of CA 19-9 determinations performed in different laboratories using currently available test systems under routine conditions.

METHODS

During the one year study period, 15 laboratories applied 7 different tests and included a liquid BIOREF control serum with pancreatic carcinoma derived CA 19-9 in their routine testing and quality control procedures. The results were collected centrally and evaluated statistically.

RESULTS

The comparability of CA 19-9 results is limited especially when different tests are used, albeit, some tests show a good correlation: The CA 19-9 values obtained by different laboratories using different test systems vary up to a factor of 2. The precision of CA 19-9 determinations was acceptable in most laboratories with coefficients of variation ranging between very low 3.2% and high 17.8%. The imprecision was slightly increased when automatic dilution procedures of the analysers were used.

CONCLUSIONS

The comparability of CA 19-9 test results must be improved. The precision is acceptable in most cases. In order to monitor key performance parameters, every laboratory should participate in external quality assessment schemes and should perform a routine internal quality control with a control serum independent from the test kit manufacturer.

Association of the intronic polymorphism rs891512 (G24943A) of the endothelial nitric oxide synthase gene with hypertension in Chilean type 2 diabetes patients

We investigated two single nucleotide polymorphisms of the NOS3 gene in type 2 diabetic patients (n=93) and healthy non-diabetic controls (n=76) and their relationship with smoking habits, body mass index, hypertension and dyslipidemia. Results showed that eNOS polymorphism rs891512 (G24943A) is associated with hypertension in Chilean individuals (p<0.05).

Effect of maximal and slow versus recreational muscle contractions on energy expenditure in trained and untrained men

AIM

The primary purpose of this study was to compare energy expenditure among resistance exercise protocols using maximally explosive or slow contractions versus recreational in trained and untrained men.

METHODS

Seven trained (21.9±2.1 yrs) and seven untrained men (20.1±2.2 yrs) performed three nearly identical exercise protocols, and a no-exercise (CONTROL) session in a randomly assigned, counterbalanced order. Subjects performed three sets of squats, dumbbell-row, deadlift, bench press, lat-pulldown, shoulder press, arm curls and dips using either recreational (REC), 2s (SLOW) or maximally explosive contractions (MAX). Expired air was collected continuously for 15 min before, ~37-43 min during, and 2 hr postexercise. Finger prick samples (25 µL) were collected and analyzed for blood lactate (BL) (mmol.L-1) before, immediately after, and during 120 min of recovery.

RESULTS

Rates of energy expenditure were significantly (P≤0.05) greater for MAX than SLOW and REC during all exercises and +5 min after exercise in trained men, and MAX was greater than REC during all exercises except deadlift in untrained men. In trained men, total kcal were significantly greater (P≤0.05) with MAX (507±48) compared to REC (431±47), but not in untrained. Conversely, BL was significantly greater (P≤0.05) after SLOW compared to REC in trained and untrained men, while BL was only greater after MAX versus REC in trained men.

CONCLUSION

For whole-body resistance exercise programs, maximally explosive contractions optimize energy expenditure in trained men, but slow contractions are recommended for untrained exercisers. Therefore, contraction intensity should be considered a program design variable for exercise prescriptions aimed to improve general health and fitness.

Targeted therapies in cancer - challenges and chances offered by newly developed techniques for protein analysis in clinical tissues

In recent years, new anticancer therapies have accompanied the classical approaches of surgery and radio- and chemotherapy. These new forms of treatment aim to inhibit specific molecular targets namely altered or deregulated proteins, which offer the possibility of individualized therapies.The specificity and efficiency of these new approaches, however, bring about a number of challenges. First of all, it is essential to specifically identify and quantify protein targets in tumor tissues for the reasonable use of such targeted therapies. Additionally, it has become even more obvious in recent years that the presence of a target protein is not always sufficient to predict the outcome of targeted therapies. The deregulation of downstream signaling molecules might also play an important role in the success of such therapeutic approaches. For these reasons, the analysis of tumor-specific protein expression profiles prior to therapy has been suggested as the most effective way to predict possible therapeutic results. To further elucidate signaling networks underlying cancer development and to identify new targets, it is necessary to implement tools that allow the rapid, precise, inexpensive and simultaneous analysis of many network components while requiring only a small amount of clinical material.Reverse phase protein microarray (RPPA) is a promising technology that meets these requirements while enabling the quantitative measurement of proteins. Together with recently developed protocols for the extraction of proteins from formalin-fixed, paraffin-embedded (FFPE) tissues, RPPA may provide the means to quantify therapeutic targets and diagnostic markers in the near future and reliably screen for new protein targets.With the possibility to quantitatively analyze DNA, RNA and protein from a single FFPE tissue sample, the methods are available for integrated patient profiling at all levels of gene expression, thus allowing optimal patient stratification for individualized therapies.

[Update on protein analysis of fixed tissues]

Tissue samples have been routinely used for decades to distinguish healthy from diseased tissue in histopathological characterization. While nucleic acid-based methodologies have been successfully in use for many years, protein-based techniques, in contrast, are at a very early stage (with the exception of immunohistochemistry). One reason for this delay may be that the scientific community has long thought that formalin-fixed and paraffin embedded (FFPE) tissues are unfit for protein analysis. However, recent reports demonstrate that many protein methods that are routinely used for frozen tissues can also be applied for FFPE tissues, including Western blot, protein microarray, matrix-assisted laser desorption/ionization (MALDI) imaging and 2D gel electrophoresis. The present article provides an overview of recent developments in this field, focussing particular attention on quantitative analysis and high throughput technologies that have the potential to be integrated into the routine workflow of clinical pathology laboratories.

Fabrication and characterization of silicon woodpile photonic crystals with a complete bandgap at telecom wavelengths

By using direct laser writing into a novel commercially available photoresist and a silicon-double-inversion procedure followed by tempering of the silicon structures, we realize high-quality centered-tetragonal woodpile photonic crystals with complete photonic bandgaps near 1.55 microm wavelength. The 6.9% gap-to-midgap ratio bandgap is evidenced by the comparison of measured transmittance and reflectance spectra with band-structure and scattering-matrix calculations.

Validation of a national disease recording system for dairy cattle against veterinary practice records

In Sweden, morbidity in dairy cattle is monitored through a national disease recording system. This system gives valuable information for research as well as advisory work and genetic evaluation. Our main objective was to evaluate the completeness in the disease recording system. Farm copies of veterinary records (n=851) from 112 herds, from March 2003 to April 2004, were compared with the information registered in the recording system. The evaluation of completeness was performed at two stages: (i) in the raw data transferred from the Swedish Board of Agriculture (SBA) to the Swedish Dairy Association (for records, cases and diagnostic events) and (ii) in the dairy disease database (DDD) at the Swedish Dairy Association (for diagnostic events). The evaluation was stratified by record type: manual and computerized records from state-employed veterinarians and private veterinarians, respectively. The completeness was high both for records (95-100%) and cases (90-99%) except manual records from private veterinarians (76% for records and 74% for cases). The overall completeness for diagnostic events was 75% in the DDD, with significant differences between record types. For all record types other than manual records from private veterinarians, the majority of diagnostic events lost disappeared after registration in the raw data from the SBA. The reasons for loss found suggest that there is potential for improvement. A multilevel logistic regression analysis showed that the completeness of diagnostic events in the DDD depended on region, diagnosis and veterinary employment. The random effect of veterinarian accounted for 35% of the modeled variation. Future studies are needed to assess how the differential misclassification affect estimates based on the data, and how to account for it.

Analysis of the intronic single nucleotide polymorphism rs#466452 of the nephrin gene in patients with diabetic nephropathy

We present the analysis of an intronic polymorphism of the nephrin gene and its relationship to the development of diabetic nephropathy in a study of diabetes type 1 and type 2 patients. The frequency of the single nucleotide polymorphism rs#466452 in the nephrin gene was determined in 231 patients and control subjects. The C/T status of the polymorphism was assessed using restriction enzyme digestions and the nephrin transcript from a kidney biopsy was examined. Association between the polymorphism and clinical parameters was evaluated using multivariate correspondence analysis. A bioinformatics analysis of the single nucleotide polymorphism rs#466452 suggested the appearance of a splicing enhancer sequence in intron 24 of the nephrin gene and a modification of proteins that bind to this sequence. However, no change in the splicing of a nephrin transcript from a renal biopsy was found. No association was found between the polymorphism and diabetes or degree of renal damage in diabetes type 1 or 2 patients. The single nucleotide polymorphism rs#466452 of the nephrin gene seems to be neutral in relation to diabetes and the development of diabetic nephropathy, and does not affect the splicing of a nephrin transcript, in spite of a splicing enhancer site.

[Cystatin C and adiponectin in diabetics with and without coronary artery disease]

BACKGROUND

Patients with type 2 diabetes have a high incidence of coronary artery disease, which is even higher among those with renal failure. A serum level of cystatin C are used to assess renal function and is a potential cardiovascular risk factor. Adiponectin is an anti-atherogenic factor.

AIM

To measure cystatin C and adiponectin in type 2 diabetic patients with and without coronary artery disease.

MATERIAL AND METHODS

Nine diabetic patients with coronary artery disease aged 76+/- 10 years, 20 diabetics without coronary artery disease aged 61 +/-5 years and 20 non diabetic subjects aged 57+/-10 years, were studied.

RESULTS

Serum levels of cystatin C (mg/L) were 1.5 (range 0.89-219), 0.81 (range 0.71-1.08) and 0.68 mg/L (range 055-0.75) in diabetics with and without coronary artery disease and controls, respectively (p <0.0001). No differences in adiponectin between groups and no association between cystatin C and adiponectin, were observed. No association between both parameters and body mass index orglycosilated hemoglobin Ale was observed. Cystatin C had a positive correlation with serum creatinine (r =0.57 p <0.001).

CONCLUSIONS

Diabetics with coronary artery disease have higher levels of cystatin C, that are closely correlated with serum creatinine levels.

FENOTIPIA E CONCENTRAÇÃO INIBITÓRIA MÍNIMA (CIM) EM LINHAGENS DE ESCHERICHIA COLI ISOLADAS DE LEITÕES COM DIARRÉIA NAS FASES DE MATERNIDADE, CRECHE, CRESCIMENTO E TERMINAÇÃO

RESUMO Escherichia coli é reconhecida como causa freqüente de diarréia em suínos em todo o mundo. O objetivo do presente estudo foi caracterizar fenotipicamente os tipos fimbriais de 349 linhagens de E. coli isoladas de suínos com diarréia, em diferentes faixas etárias, utilizando os testes de microhemaglutinação e soroaglutinação, bem como determinar o perfil de suscetibilidade frente aos principais antimicrobianos utilizados em granjas de suínos. Do total de 159 linhagens de E. coli que não aglutinaram eritrócitos no teste de hemaglutinação manose-resistente (HAMR), 57 (35%) foram positivas para a expressão do antígeno fimbrial F6 no teste de soroaglutinação rápida em placa. Considerando a faixa etária e o fenótipo fimbrial, os sorotipos de E. coli, potencialmente patogênicos mais prevalentes até a terceira semana de idade, foram F5 (K99), F6 (987P), F42 e F41 em, respectivamente, 29%, 23%, 11% e 10% das linhagens. Em leitões com mais de 25 dias, predominaram fimbrias F4 (K88) em 44,6% (58) das linhagens. Os animais foram suscetíveis às cepas contendo F4, durante todas as faixas etárias, mas com maior predominância em idades mais avançadas, acima de 76 dias. Os maiores índices de resistência das linhagens foram observados para oxitetraciclina (84,0%), gentamicina (76,0 %) e amoxicilina (72,0%). Os menores valores de Concentração Inibitória Mínima (CIM) 50 e 90 foram observados para o ceftiofur.

Clinicopathologic features of breast disease in Jamaica: findings of the Jamaican Breast Disease Study, 2000-2002

OBJECTIVE

To describe the clinicopathologic profile of breast disease in Jamaica.

METHODS

The Jamaican Breast Disease Study is an ongoing prospective, multidisciplinary investigation of breast disease at the University Hospital of the West Indies (UHWI). The initial phase was a prevalence survey comprising all consenting patients referred to the Surgical Outpatient Department (SOPD) UHWI, for breast disease. Demographic, clinical, radiologic and pathologic information were recorded for each patient and the data for the first three years (2000-2002) were analyzed.

RESULTS

A total of 1189 patients was enrolled for the study period (28.8% of all new SOPD patients). The age range was 10 to 93 years (mean/SD = 36.5 +/- 16.4 years) with a female : male ratio of 14:1. Most patients (67.8%) presented with a palpable lump and the clinical diagnosis was benign in the majority (70.4%) of patients. Fibroadenoma was the most common benign histologic result (39.4% of all biopsies) followed by non-proliferative (fibrocystic) disease (19.3% of all biopsies). Proliferative disease without atypia, complex fibroadenoma and atypical ductal hyperplasia accounted for 6.9%, 2.6% and 0.4% of biopsies respectively. Overall, 23.4% of biopsies showed malignant histology (10.8% patients); invasive ductal carcinoma accounted for the majority of these cases (69.5%).

CONCLUSIONS

The majority of patients with breast disease in Jamaica are young women with clinically benign disease. There was a low prevalence of clinically significant premalignant disease. This is the first study to prospectively describe the clinicopathologic features of breast disease in Jamaica and supports the need for advocating breast cancer screening to facilitate detection of significant premalignant disease and early stages of breast cancer.

[Porphyria and pregnancy. Review of 17 women]

BACKGROUND

Hormonal changes, prolonged fasting due to vomiting and some medications used during pregnancy, may cause an acute crisis of porphyria, sometimes unveiling a latent disease. Porphyria may also affect the evolution of pregnancy.

AIM

To study the reciprocal influence in the evolution of both pregnancy and porphyria.

MATERIAL AND METHODS

Retrospective review of medical records of women with porphyria followed by the authors. If additional information was required, an additional visit to the clinic was scheduled. The characteristics of pregnancy, delivery and the newborn were analyzed.

RESULTS

Information about 60 pregnancies in 17 women aged 18 to 43 years was gathered. Among women with acute porphyria, one with coproporphyria had four pregnancies, nine with variegate porphyria had a total of 34 pregnancies and two with acute intermittent porphyria had six pregnancies. Five women with porphyria cutánea had a total of 16 pregnancies. Influence of porphyria in pregnancy: Compared to the general population, no differences were observed in birth weight of newborns, frequency of gestational hypertension, term or preterm deliveries of live newborns, spontaneous abortions nor in tubal pregnancies; there was a high frequency of hyperemesis gravidarum. Influence of pregnancy in porphyria: 5 of the 12 patients with acute porphyria, had an acute porphyria crisis, 3 during the puerperal period and 2 during pregnancy (42% of women, 11% of pregnancies). All these crisis were associated to the administration of medications. All patients survived. Two of these women had six ulterior pregnancies without complications.

CONCLUSIONS

Women with porphyria that become pregnant have a higher frequency of hyperemesis gravidarum. Crises among women with acute porphyrias, were always associated with the use of potentially dangerous medications.

[Biphasic insulin aspart for the management of diabetic patients with unsatisfactory metabolic control]

BACKGROUND

Biophasic insulin aspart (InAsBi) is a mixture of 30% of rapid acting soluble aspart insulin and 70% aspart insulin retarded with protamine. The soluble portion reduces postprandial serum glucose rises and the retarded portion reduces basal glucose levels.

AIM

To assess the efficacy of biphasic insulin aspart in diabetics with a bad metabolic control.

MATERIAL AND METHODS

Multicentríc study that included diabetic patients with a glycosilated hemoglobin over 7% that were transferred to treatment with InAsBi, given in one to three daily doses, according to glycemic control and followed for 12 weeks. At the end of follow up, glycosilated hemoglobin levels (HbA1c) were measured again.

RESULTS

One hundred ninety six patients were enrolled and 154, age 59+/- 12 (84 females), completed the follow up. HbA 1 c levels decreased in at least 1% in 96 and increased in eight cases. In the total group HbA1c decreased from 10.1+/- 1.7 to 8.4+/-1.4% (p <0.01). Those with higher initial values and with oral therapy, had the greatest reductions. At the end of the observation period, 29 patients received one daily dose of InAsBi, 114 two doses and 11 three doses. Two patients had allergy, one systemic and one in the injection site.

CONCLUSIONS

In this group of diabetic patients with a bad metabolic control, the use of InAsBi was associated with a significant reduction of glycosilated hemoglobin levels.