Completeness and accuracy of data in spine registries: an independent audit-based study

European Spine Journal - Clinical registries are used for quality management and clinical research. Due to the importance and implications of both aims, completeness and high quality of data are of...     

A retrospective study of 113 consecutive cases of surgically treated spondylodiscitis patients. A single-center experience

Background

Recommendations for the operative treatment of spondylodiscitis are still a controversial issue.

Methods

A retrospective review identified 113 consecutive patients who underwent surgical debridement and instrumentation for spondylodiscitis between 2006 and 2010 at our department.

Results

The mean age at presentation was 65 years; 78 patients were male (69 %). Distribution of the inflammation was lumbar in 68 (60 %), thoracic in 19 (17 %) and cervical in 20 (18 %) cases. Six patients (5 %) had two concomitant non-contiguous spondylodiscitis foci in different segments of the spine. Epidural abscess was found in 33 patients (29 %). One hundred four patients (92 %) had pain. Neurological deficit was found in 40 patients (35 %). In the thoracic and lumbar cases, dorsal instrumentation alone was considered sufficient in 26 cases; additional interbody fusion from the posterior was performed in 44 cases. A 360° instrumentation was performed in 22 cases. In the cervical cases, only ventral spondylodesis and plating were performed in eight cases, only dorsal instrumentation in five and 360° instrumentation in seven. Postoperative intravenous antibiotics were administered for 14.4?±?9.3 (mean ± SD) days followed by 3.2?±?0.8 (mean ± SD) months of oral antibiosis. Complete healing of the inflammation was achieved in 111 (98 %) cases. Two patients died because of septic shock, both with fulminant endocarditis. Pain resolved in all cases. Neurological deficits were completely resolved in 20 patients, and 14 patients had a partial recovery.

Conclusion

The results of our retrospective study show that surgical treatment of spondylodiscitis with a staged surgical approach (if needed) and a short 1-2-week period of intravenous antibiotics followed by 3 months of oral antibiotics is appropriate for most patients in whom conservative treatment has failed or is not advisable. Furthermore, surgical treatment of newly diagnosed spondylodiscitis might be recommended as an initial treatment option in many cases. Thereby the choice of fusion material (autologous bone, titanium, PEEK) seems less important.     

Combined remote ischemic perconditioning and local postconditioning on liver ischemia–reperfusion injury

Background

Remote ischemic perconditioning (rPER) is the newest technique described to mitigate ischemia and reperfusion (IR) injury. Local postconditioning (POS) is also an effective technique for this purpose. It is uncertain if adding local POS to rPER provides superior liver protection, so we tested this hypothesis.

Materials and methods

Twenty five Wistar rats were assigned into five groups: sham, IR, POS, rPER, and rPER + POS. Animals were subjected to liver ischemia for 60 min. POS consisted of four cycles of 5-min liver perfusion followed by 5-min liver ischemia (40 min total) after the major ischemic period. rPER consisted of four cycles of 5-min hindlimb ischemia followed by 5 min hindlimb perfusion contemporaneously to major liver ischemic period, during its last 40 min. After 2 h, median and left lobes were harvested for malondialdehyde and Trolox equivalent antioxidant capacity (TEAC) measurement, and blood for the measurement of serum transaminases.

Results

All tissue conditioning techniques were able to reduce transaminases serum levels, having no differences among them. All tissue conditioning techniques were able to reduce hepatic tissue MDA level; however, only rPER + POS had higher values than SHAM. All tissue conditioning techniques also enhanced TEAC; however, only POS had lower TEAC than SHAM.

Conclusions

rPER appears as the most promising technique to avoid IR injury. This technique reduced oxidative stress of cell membranes and lowered transaminases serum level. There was no additive protection when POS and rPER were held together.     

From the Cover: Trypanosomal TAC40 constitutes a novel subclass of mitochondrial β-barrel proteins specialized in mitochondrial genome inheritance

Mitochondria cannot form de novo but require mechanisms allowing their inheritance to daughter cells. In contrast to most other eukaryotes Trypanosoma brucei has a single mitochondrion whose single-unit genome is physically connected to the flagellum. Here we identify a β-barrel mitochondrial outer membrane protein, termed tripartite attachment complex 40 (TAC40), that localizes to this connection. TAC40 is essential for mitochondrial DNA inheritance and belongs to the mitochondrial porin protein family. However, it is not specifically related to any of the three subclasses of mitochondrial porins represented by the metabolite transporter voltage-dependent anion channel (VDAC), the protein translocator of the outer membrane 40 (TOM40), or the fungi-specific MDM10, a component of the endoplasmic reticulum–mitochondria encounter structure (ERMES). MDM10 and TAC40 mediate cellular architecture and participate in transmembrane complexes that are essential for mitochondrial DNA inheritance. In yeast MDM10, in the context of the ERMES, is postulated to connect the mitochondrial genomes to actin filaments, whereas in trypanosomes TAC40 mediates the linkage of the mitochondrial DNA to the basal body of the flagellum. However, TAC40 does not colocalize with trypanosomal orthologs of ERMES components and, unlike MDM10, it regulates neither mitochondrial morphology nor the assembly of the protein translocase. TAC40 therefore defines a novel subclass of mitochondrial porins that is distinct from VDAC, TOM40, and MDM10. However, whereas the architecture of the TAC40-containing complex in trypanosomes and the MDM10-containing ERMES in yeast is very different, both are organized around a β-barrel protein of the mitochondrial porin family that mediates a DNA–cytoskeleton linkage that is essential for mitochondrial DNA inheritance.Mitochondria are a hallmark of all eukaroytic cells. They derive from an endosymbiontic event between a free-living bacterium and a presumably prokaryotic host cell. More than 1.5 billion years of evolution resulted in a great diversification of mitochondria. As a consequence, the shape and number of organelles per cell as well as size, content, copy number, and organization of their genomes vary greatly between different taxons (1). However, all eukaryotes must be able to faithfully transmit mitochondria to their offspring (2, 3).Unlike most other eukaryotes, the parasitic protozoa Trypanosoma brucei has a single mitochondrion throughout its life and its cell cycle. Due to the single-unit nature of the mitochondrion, its duplication must be coordinated with the duplication of the nucleus (4). The mitochondrial genome of T. brucei, termed kinetoplast DNA (kDNA), is essential for growth of both the procyclic insect stage and the bloodstream form of the parasite (5). It consists of a disk-shaped single-unit kDNA network that localizes to a distinct region within the mitochondrial matrix (6). The kDNA is physically connected with the cytosolic basal body, the organizing center of the eukaryotic flagellum, via a high-order transmembrane structure termed tripartite attachment complex (TAC) (7) of which only few components have been identified (8–10). Replication of the kDNA network occurs at a defined stage of the cell cycle shortly before the onset of the nuclear S phase. After replication, the kDNA networks need to be correctly positioned so that during cell and mitochondrial division each daughter cell receives a single organelle with a single kDNA network. This process requires an intact TAC and is mediated by the movement of the basal body: one kDNA network remains connected to the basal body of the old flagellum whereas the other one segregates with the basal body of the new flagellum (7, 11).Unlike trypanosomes, Saccharomyces cerevisiae propagates by budding and contains highly dynamic mitochondria that constantly divide and fuse (12, 13). Mitochondrial inheritance in budding yeast therefore requires a mechanism to move mitochondria and their genomes from the mother cell into the growing bud. The protein-associated mitochondrial genomes of S. cerevisiae, termed nucleoids, localize to dozens of globular foci that are distributed all over the organelles. Most actively replicating nucleoids are associated with a protein complex that includes the outer membrane (OM) protein MDM10 as a central unit, as well as the proteins MDM12, MDM34, and MMM1 (14–16). The protein complex forms the endoplasmic reticulum (ER)–mitochondria encounter structure (ERMES) tethering the ER to the mitochondrion (17). The ERMES has also been suggested to connect to cytosolic actin fibers that mediate the movement of mitochondria to the bud of dividing yeast cells (14, 18, 19). Besides its role in mitochondrial inheritance, the ERMES has been implicated in maintenance of mitochondrial morphology and in phospholipid and calcium exchange as well as in the assembly of the protein translocase of the mitochondrial OM (TOM) (20, 21). Some of the proposed ERMES functions are controversial and there is evidence that some of them might be due to secondary effects caused by the drastically altered mitochondrial morphology (22).The central ERMES subunit, the β-barrel protein MDM10 belongs to the mitochondrial porin superfamily, which comprises the three members voltage-dependent anion channel (VDAC), Tom40, and MDM10. Whereas VDAC and Tom40 have so far been found in all eukaryotes, including T. brucei (23, 24), MDM10 is specific to the fungal clade.In this study we identify a mitochondrial OM protein of T. brucei as a novel component of the TAC. We show that the protein defines a novel subclass of the mitochondrial porin superfamily that is specialized in mitochondrial DNA inheritance.     

Associations Between Macrolevel Economic Factors and Weight Distributions in Low- and Middle-Income Countries: A Multilevel Analysis of 200?000 Adults in 40 Countries

Objectives. We examined associations between macrolevel economic factors hypothesized to drive changes in distributions of weight and body mass index (BMI) in a representative sample of 200 796 men and women from 40 low- and middle-income countries.Methods. We used meta-regressions to describe ecological associations between macrolevel factors and mean BMIs across countries. Multilevel regression was used to assess the relation between macrolevel economic characteristics and individual odds of underweight and overweight relative to normal weight.Results. In multilevel analyses adjusting for individual-level characteristics, a 1–standard-deviation increase in trade liberalization was associated with 13% (95% confidence interval [CI] = 0.76, 0.99), 17% (95% CI = 0.71, 0.96), 13% (95% CI = 0.76, 1.00), and 14% (95% CI = 0.75, 0.99) lower odds of underweight relative to normal weight among rural men, rural women, urban men, and urban women, respectively. Economic development was consistently associated with higher odds of overweight relative to normal weight. Among rural men, a 1–standard-deviation increase in foreign direct investment was associated with 17% (95% CI = 1.02, 1.35) higher odds of overweight relative to normal weight.Conclusions. Macrolevel economic factors may be implicated in global shifts in epidemiological patterns of weight.Cardiovascular diseases are among the leading causes of death in low- and middle-income countries (LMICs),1 where mortality from such diseases has been increasing and is expected to continue doing so until 2030.2 In parallel to this trend, there has been an increase in average body mass index (BMI; defined as weight in kilograms divided by the square of height in meters) in most regions of the world.3 With population-based studies indicating a U- or J-shaped relation between BMI and cardiovascular disease mortality,4,5 these shifts in BMI may increase the proportion of the population at greatest risk for cardiovascular diseases. As such, increases in BMI may contribute to escalating cardiovascular disease mortality in LMICs,6 highlighting the need for understanding BMI patterns and predictors.Comparative longitudinal data that can be used to monitor BMI changes (often expressed according to prevalence of underweight, overweight, and obesity) across LMICs are scant; however, existing data suggest that the prevalence of underweight has decreased, the prevalence of overweight and obesity has increased, and, in general, there is a greater burden of overweight than underweight in most LMICs, particularly in urban areas.7–9 Shifts in the key determinants of weight, including diet and physical activity, are hypothesized to influence these patterns.3 Major changes in global dietary consumption have increased per capita food intake in LMICs, as well as the proportion of people’s daily diet derived from energy-dense and fatty foods.3,10–12 Although cross-national and longitudinal data on physical activity are limited, available evidence suggests that forms of transportation, employment, and leisure activities have become more sedentary and may contribute to changing patterns of weight at the population level.13,14Macrolevel economic factors, including economic development, urbanization, foreign investment, and trade liberalization, are hypothesized to drive shifting patterns of dietary composition, physical activity, and other determinants of nutritional outcomes.3,15 Economic growth and attendant increases in per capita income, for example, are associated with increased consumption of energy-dense foods,16 and recent cross-national analyses suggest that economic development is associated with a faster rate of growth in the prevalence of overweight among lower-income groups in LMICs.17,18 Urbanization is hypothesized to increase access to processed diets, reduce opportunities for physical activity, and expose residents to food marketing, thereby promoting a more sedentary lifestyle associated with less energy expenditure and greater caloric intake.15The influx of foreign direct investment (FDI), defined as investments by an enterprise in one country intended to acquire a lasting management interest in an enterprise operating in a foreign economy, represents one mechanism through which transnational corporations enter into new markets. FDI inflows are, along with greater openness to trade,19 hypothesized to be a key element in reshaping the global market for food, particularly in LMICs, by threatening traditional modes of agricultural production and facilitating the processing, distribution, and marketing of lower-cost, energy-dense food.20,21Despite the potential role that these macrolevel economic factors may play in shaping the epidemiological pattern of diet, behavior, and weight in LMICs, few empirical studies have investigated the relation between contextual factors and individual weight. A limited number of ecological studies have been conducted,9,22 but their results cannot be used to draw inferences about health at the individual level. Furthermore, the social patterning of diet and physical activity according to area of residence (urban or rural) and gender suggests that the macrolevel factors posited to drive changes in weight may have distinct implications for particular groups of individuals,23,24 and ecological studies cannot assess whether associations between macrolevel economic characteristics and weight vary according to such individual-level characteristics.We used data from a sample of approximately 200 000 adults from 40 LMICs to describe the ecological associations between macrolevel economic factors hypothesized to drive changes in determinants of weight (i.e., economic development, urbanization, FDI, trade liberalization) and average BMIs across countries and examine the association between macrolevel characteristics and the probability at the individual level of underweight and overweight or obesity relative to normal weight. We also assessed cross-level interactions of macrolevel factors with gender and area of residence.     

Heterozygous TREM2 mutations in frontotemporal dementia

A causative association was recently demonstrated between homozygous TREM2 mutations and frontotemporal dementia (FTD)-like syndrome and between heterozygous TREM2 exon2 genetic variations and late-onset Alzheimer's disease (AD). The objective of this study was to evaluate whether heterozygous TREM2 genetic variations might be associated to the risk of FTD. TREM2 exon 2 was sequenced in a group of 1030 subjects—namely, 352 patients fulfilling clinical criteria for FTD, 484 healthy control subjects (HCs), and 194 patients with AD. The mutation frequency and the associated clinical characteristics were analyzed. We identified 8 missense and nonsense mutations in TREM2 exon 2 in 24 subjects. These mutations were more frequent in patients with FTD than in HCs (4.0% vs. 1.0%, p = 0.005). In particular, TREM2 Q33X, R47H, T66M, and S116C mutations were found in FTD and were absent in HCs. These mutations were associated with either the semantic variant of primary progressive aphasia or the behavioral variant FTD phenotypes. The FTD and AD groups were not significantly different with regard to TREM2 genetic variation frequency (AD: 2.6%, p = 0.39). Heterozygous TREM2 mutations modulate the risk of FTD in addition to increasing susceptibility to AD. Additional studies are warranted to investigate the possible role of these mutations in the pathogenesis of neurodegenerative disorders.     

High-load resistance exercise with superimposed vibration and vascular occlusion increases critical power, capillaries and lean mass in endurance-trained men

Purpose

It is a widely accepted premise in the scientific community and by athletes alike, that adding resistance exercise to a regular regimen of endurance training increases endurance performance in endurance-trained men. However, critical power (CP), capillarization, and myofiber size remain unaffected by this addition. Therefore, we tested whether the superimposition of resistance exercise with whole-body vibration and vascular occlusion (vibroX) would improve these variables in endurance-trained males relative to resistance exercise alone.

Methods

Twenty-one young, endurance-trained males were randomly assigned either to a vibroX (n = 11) or resistance (n = 10) training group. Both groups trained in a progressive mode twice a week for 8 weeks. Pre and post training, histochemical muscle characteristics, thigh muscle size, endurance and strength parameters were determined.

Results

vibroX increased CP (P = 0.001), overall capillary-to-fiber ratio (P = 0.001) and thigh lean mass (P < 0.001), while these parameters were unaffected by resistance training. The gain in CP by vibroX was positively correlated with the gain in capillarization (R ² = 0.605, P = 0.008), and the gain in thigh lean mass was paralleled by increases in MyHC-1 and MyHC-2 fiber cross-sectional areas and strength. Maximum voluntary torque and the finite work capacity above CP (W′) increased significantly only following resistance training.

Conclusions

We achieved a proof of concept by demonstrating that modification of resistance exercise by superimposing side-alternating whole-body vibration and sustained vascular occlusion induced further improvements in CP, capillarization and hypertrophy, all of which were not observed with resistance training alone.