Detecting the symplesiomorphy trap: a multigene phylogenetic analysis of terebelliform annelids

BACKGROUND

For phylogenetic reconstructions, conflict in signal is a potential problem for tree reconstruction. For instance, molecular data from different cellular components, such as the mitochondrion and nucleus, may be inconsistent with each other. Mammalian studies provide one such case of conflict where mitochondrial data, which display compositional biases, support the Marsupionta hypothesis, but nuclear data confirm the Theria hypothesis. Most observations of compositional biases in tree reconstruction have focused on lineages with different composition than the majority of the lineages under analysis. However in some situations, the position of taxa that lack compositional bias may be influenced rather than the position of taxa that possess compositional bias. This situation is due to apparent symplesiomorphic characters and known as "the symplesiomorphy trap".

RESULTS

Herein, we report an example of the sympleisomorphy trap and how to detect it. Worms within Terebelliformia (sensu Rouse & Pleijel 2001) are mainly tube-dwelling annelids comprising five 'families': Alvinellidae, Ampharetidae, Terebellidae, Trichobranchidae and Pectinariidae. Using mitochondrial genomic data, as well as data from the nuclear 18S, 28S rDNA and elongation factor-1α genes, we revealed incongruence between mitochondrial and nuclear data regarding the placement of Trichobranchidae. Mitochondrial data favored a sister relationship between Terebellidae and Trichobranchidae, but nuclear data placed Trichobranchidae as sister to an Ampharetidae/Alvinellidae clade. Both positions have been proposed based on morphological data.

CONCLUSIONS

Our investigation revealed that mitochondrial data of Ampharetidae and Alvinellidae exhibited strong compositional biases. However, these biases resulted in a misplacement of Trichobranchidae, rather than Alvinellidae and Ampharetidae. Herein, we document that Trichobranchidae was apparently caught in the symplesiomorphy trap suggesting that in certain situations even homologies can be misleading.

Evaluation of a therapeutic diet for feline degenerative joint disease

BACKGROUND

Feline degenerative joint disease (DJD) is common and there are no approved therapies for the alleviation of the associated pain.

OBJECTIVE

To test a diet high in eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) content and supplemented with green-lipped mussel extract and glucosamine/chondroitin sulfate (test-diet) for its pain-relieving and activity-enhancing effects in cats with painful, mobility-impairing DJD over a 9-week period.

ANIMALS

Forty client-owned cats.

METHODS

Randomized, controlled, blinded, parallel group, prospective clinical study. Cats with no detectable systemic disease, and with at least 1 appendicular joint with radiographic evidence of DJD where manipulation elicited an aversive response were included. Cats were randomly allocated to the test-diet or control diet (C-diet). Outcome measures were subjective owner and veterinarian assessments, and objective activity monitoring (accelerometry). Nonparametric statistics were used to evaluate changes within and between groups for both subjective and objective data, and locally weighted scatterplot smoothing regression analysis was used to predict activity changes.

RESULTS

The primary objective outcome measures indicated that activity declined significantly (P < .001) in the C-diet group, significantly increased (P < .001) in the test-diet group and there was a significant difference between the groups (P < .001).

CONCLUSION AND CLINICAL IMPORTANCE

A diet high in EPA and DHA and supplemented with green-lipped mussel extract and glucosamine/chondroitin sulfate improved objective measures of mobility. Dietary modulation might be 1 method to use to improve mobility in cats with DJD-associated pain.

Chorioretinitis of the newborn with herpes simplex virus type 1. Report of a case

A disseminated herpes simplex virus (HSV) infection involving the central nervous system and accompanied by chrioretinitis in a a 3-week-old girl is described. The aetiologic diagnosis was established on the basis of vrius isolated from skin vesicles, and a significant rise in complement fixing antibodies to HSV type 1. The mode of transmission of the virus to the infant apparently was direct contact with an oral lesion in the mother, that was present at the time of delivery. The patient survived but became blind and microcephalic, with severe neurological sequelae. The virus isolated was identified as HSV type 1, which is an infrequent finding in herpetic chorioretinitis of the newborn.

Hypothermia and infection in Wernicke's encephalopathy

Two cases of acute Wernicke's encephalopathy with severe hypothermia as the major presenting feature are reported. Treatment with thiamine was rapidly introduced, but hypothermia nevertheless persisted for several weeks, at times masked by intercurrent infections.

Non-pharmacological treatment and prevention of bone loss after spinal cord injury: a systematic review

OBJECTIVE

Review the literature on non-pharmacological prevention and treatment of osteoporosis after spinal cord injury (SCI).

METHODS

PubMed, EMBASE and the Cochrane Controlled Trials Register were searched. All identified papers were read by title, abstract and full-length article when relevant. Hand search of the articles' sources identified additional papers. For included studies, the level of evidence was determined.

RESULTS

No studies conclusively showed an effective intervention. However, there are few randomized controlled trials (RCTs), and those that exist assess interventions and outcome measures that could be improved. Five studies on weight-bearing early post-injury are conflicting, but standing or walking may help retain bone mineral. In the chronic phase, there was no effect of weight bearing (12 studies). One study found that an early commencement of sports after SCI improved bone mineral, and the longer the period of athletic career, the higher the (leg) bone mineral. Early after SCI, there may be some effects of electrical stimulation (ES) (five studies). Chronic-phase ES studies vary (14 studies, including mixed periods after injury), but improvement is seen with longer period of training, or higher frequency or stimulus intensity. Improvements correspond to trabecular bone in the distal femur or proximal tibia. Impact vibration and pulsed electromagnetic fields may have some positive effects, whereas pulsed ultrasound does not. Six studies on the influence of spasticity show inconsistent results.

CONCLUSIONS

Bone mineral should be measured around the knee; the length and intensity of the treatment should be sufficiently long and high, respectively, and should commence early after SCI. If bone mineral is to remain, the stimulation has to be possibly continued for long term. In addition, RCTs are necessary.

Mortality after discharge from the intensive care unit during the early weekend period: a population-based cohort study in Denmark

BACKGROUND

As a result of a shortage of intensive care capacity, patients may be discharged prematurely early during weekends which may lead to an increased mortality and risk of readmission to intensive care units (ICU). We examined whether discharge from the ICU during the first part of the weekend was associated with an increased mortality and readmission to the ICU.

METHODS

The study was conducted at a university clinic of internal medicine and included all patients admitted for the first time to the ICU, and discharged alive in the period 1 January 2001 to 31 December 2005. Patients were divided in those discharged between 00.00 h Friday and 24.00 h Saturday (weekend group) and those discharged Sunday to Thursday (non-weekend group). The main outcome was time from discharge from the ICU to the combined endpoint death or re-admission to ICU which ever came first. We used Kaplan-Meier analysis and Cox's proportional-hazards regression to compute survival curves and risk ratio estimates.

RESULTS

There were 228 patients in the weekend group and 555 patients in the non-weekend group. Crude and adjusted 28-day risk ratio of the combined endpoint was 1.50 [95% confidence interval (CI): 1.15-1.97] and 1.43 (1.09-1.87) in the weekend group. Although an increased risk of death was observed in the weekend group immediately after discharge from the ICU, the difference in mortality between the two groups had disappeared after 2 years.

CONCLUSION

Medical patients discharged from the ICU early in the weekends seem to have an increased mortality and risk of readmission to the ICU.

Different composition of intrahepatic lymphocytes in the immune-tolerance and immune-clearance phase of chronic hepatitis B

Based on virological and biochemical parameters patients with chronic hepatitis B virus (HBV) are divided into distinct clinical phases: the immune-tolerance phase, the immune-clearance phase, and the inactive carrier state. Unclear is whether these phases have characteristic intrahepatic immune responses. The composition of liver-derived lymphocytes in patients with chronic HBV infection was studied. In 47 patients the composition of liver-derived lymphocytes was analyzed by flow cytometry of fine needle aspiration biopsies of the liver. The proportion natural killer (NK) cells in the liver was significantly higher in immune-tolerant than in immune-clearance patients and inactive carriers. No differences were found in proportion CD4+ T-cells and CD8+ T-cells, in these phases. However, when patients in the immune-clearance phase, with similar alanine transaminase (ALT), were grouped according to viral load, the proportion CD8+ T-cells was higher in those with high viral load. In contrast, the proportion CD4+ T-cells was increased in patients with low HBV-DNA. These differences were absent in the peripheral blood (PB). Intrahepatic HBV-specific CD8+ T-cells were mainly found in immune-clearance patients with low viral load. In conclusion, clear differences in the intrahepatic cellular infiltrate were found between the various clinical phases of chronic HBV infection. These findings are relevant to the design of new, individualized anti-viral strategies.

Polymorphisms in the T cell regulatory gene cytotoxic T lymphocyte antigen 4 influence the rate of acute rejection after liver transplantation

BACKGROUND

The cytotoxic T lymphocyte antigen 4 (CTLA-4) gene encodes for a membrane bound (mCTLA-4) and a soluble (sCTLA-4) isoform, which are both involved in regulation of T cell function. The CTLA-4 +49A/G single nucleotide polymorphism (SNP) influences expression of mCTLA-4; +6230G/A SNP affects the production of sCTLA-4.

AIM

To examine whether these functional SNPs influence the rate of rejection after liver transplantation.

PATIENTS AND METHODS

Liver graft recipients (n = 483) were genotyped for both SNPs, and haplotypes were reconstructed. Association with rejection was tested by the log rank test using the Kaplan-Meier method with time to the first acute rejection episode as outcome. Multiple analysis of SNPs together with demographic factors was performed by Cox regression.

RESULTS

Three haplotypes were observed in the cohort: +49A/+6230A, +49A/+6230G, and +49G/+6230G. The +49A/+6230G haplotype was significantly and dose dependently associated with acute rejection (p = 0.01). Of the demographic factors tested, only underlying liver disease was significantly associated with rejection. Adjusted for underlying liver disease, each additional +49A/+6230G haplotype allele resulted in a significantly higher risk of acute rejection (risk ratio 1.34 (95% confidence interval 1.04-1.72); p = 0.02). Patients who lacked this haplotype had the lowest, carriers an intermediate, and homozygotes the highest risk of acute rejection.

CONCLUSION

The CTLA-4 +49A/+6230G haplotype, which encodes for normal mCTLA-4 expression but reduced sCTLA-4 production, is a co-dominant risk allele for acute rejection after clinical liver transplantation. This implies that even under immunosuppression, CTLA-4 is critically involved in the regulation of the human immune response to allogeneic grafts.

Effects of soy supplementation on blood lipids and arterial function in hypercholesterolaemic subjects

BACKGROUND

Studies on soy supplementation suggest a cardioprotective potential.

OBJECTIVE

To examine the effects on LDL cholesterol and arterial function as a result of dietary enrichment with soy supplementation.

DESIGN

A Randomized, double blind, parallel intervention trial.

SETTING

Department of Endocrinology and Metabolism C, Aarhus University Hospital, and Department of Human Nutrition, The Royal Veterinary and Agricultural University, Denmark.

SUBJECTS

In all, 100 hypercholesterolaemic but otherwise healthy subjects were included in the study of which 89 completed it.

INTERVENTIONS

Subjects were randomly assigned to 24 weeks of daily intake of either a soy supplement, Abalon (30 g soy protein, 9 g cotyledon fibre and 100 mg isoflavones) or placebo (30 g of casein). The soy supplement and placebo were provided in two sachets daily that were stirred in water. Fasting plasma lipids, TNF-alpha, homocysteine, insulin sensitivity, homeostasis model assessment (HOMA-IR), serum insulin, serum glucose, blood pressure as well as Glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and plasma lipids to a fat-rich meal were recorded before and after the intervention. In a sub study in 32 subjects, arterial dilatory capacity, compliance, and distensibility were recorded before and after the intervention.

RESULTS

In the main study, no difference in fasting plasma lipid levels or insulin sensitivity was found between soy-based supplement and placebo. A significant postprandial increase in GIP to the meal test was observed in the soy group (P < 0.05). In a substudy, no difference between the groups in changes in flow-mediated vasodilatation (P = 0.84) was detected, while the soy supplementation caused a reduction in LDL and total cholesterol.

CONCLUSIONS

No significant effects on blood lipids were observed in the main study to a soy supplementation in hypercholesterolaemic subjects after 24 weeks. In the substudy, the soy supplementation, however, reduced LDL and total cholesterol but did not influence markers of arterial function.

Outcome following liver transplantation for primary sclerosing cholangitis in the Nordic countries

BACKGROUND

Primary sclerosing cholangitis (PSC) is the most common indication for liver transplantation in the Nordic countries. Because these patients are difficult to evaluate with regard to timing of liver transplantation, it is important to establish predictors of post-transplant survival.

METHODS

Data from two groups of patients receiving liver allografts during 1982-2001 were recorded: (a) PSC patients and (b) comparison patients. Outcome following transplantation has been recorded for all patients. Regression analyses have been performed for PSC patients to analyse predictors of patient and graft survival.

RESULTS

A total of 245 PSC and 618 comparison patients received a first liver allograft in the period 1982 until the end of the study. The overall 1-, 3- and 5-year patient survival rates were 82%, 77% and 75%, and 80%, 77% and 74% in the PSC group and comparison group, respectively. Survival following transplantation has increased with time in both the PSC and the comparison group. Recent year of transplantation, no previous hepatobiliary surgery and a lower MELD score were predictors of survival following transplantation for PSC patients. PSC patients had a higher rate of re-transplantations (13% versus 8%, P = 0.01). Predictors of re-transplantation in PSC patients were an episode of early rejection and vascular thrombosis.

CONCLUSION

In PSC patients, year of transplantation, previous hepatobiliary surgery and MELD score are predictors of survival following transplantation and these patients are more frequently in need of re-transplantation compared to the comparison group.

Mechanical properties of the skin: a comparison between two suction cup methods

BACKGROUND/AIMS

The objective measure of mechanical properties of the skin is relevant to the clinician as well as to the researcher concerned with skin physiology. The lack of standardization among methods used to obtain visco-elastic data from the skin is however, apparent and represents an obstacle to comparison of the results derived from the various studies concerning the subject.

METHODS

The mechanical properties of the ventral forearm were studied in 35 healthy volunteers. The Dermaflex and the DermaLab (Both Cortex Technology, Hadsund, Denmark) were compared. The results were analyzed with descriptive statistics and correlations using non-parametric methods. Measurement accuracy was assessed using coefficient of variation. Sub analysis was made in groups according to gender and age.

RESULTS

The overall correlations between the two methods were moderate (r = 0.383-0.437). A greater coefficient of variation was found in the DermaLab machine. Significant differences were found between all values of both methods when comparing the mechanical properties of the skin in 30-39 years olds versus the group of 40-58 years olds. No differences were found between the genders.

CONCLUSIONS

The results indicate that both methods are useful in the study of the mechanical aspects of the skin, especially for detecting age-related changes. The Dermaflex seems to produce more accurate for data. This is thought to be due to the conceptual design differences between the two methods. The methods measure related but not identical values of the mechanical properties of the skin, as reflected by the limited positive correlation between them.

Assessing non-linear estimation procedures for human growth models

BACKGROUND

In the last 20 years several non-linear models with a relatively small number of parameters have provided useful descriptions of the complete human growth curve. However, some aspects of the estimation procedures used have not been properly studied, e.g. estimation of biases, measures of non-linearity, and the possibility of autocorrelated errors and heteroscedasticity.

OBJECTIVES

To present a detailed analysis of these aspects for five well-known non-linear models (Preece-Baines, Shohoji-Sasaki and three models proposed by Jolicoeur et al.) and a large data set (the MRC Edinburgh Longitudinal Study).

SUBJECTS

A cohort of 74 females and 103 males collected for the Edinburgh Longitudinal Study for the MRC Human Genetics Unit, Edinburgh, UK, comprising approximately quarterly height measurements for small ages and semestral height measurements for the remaining ages up to the early twenties.

RESULTS

We found little evidence of extreme curvature and relatively small, cyclical patterns in the residuals. The estimates obtained with ordinary non-linear least squares were very close to those obtained with more complicated estimation procedures.

CONCLUSIONS

The five models studied are reasonably robust against most of the problems encountered when fitting non-linear models to human growth data; this confirms some conjectures which have been taken for granted by a large number of authors. The presence of cyclical patterns is a consequence of the global description of growth attempted by these five models.

When should densitometry be repeated in healthy peri- and postmenopausal women: the Danish osteoporosis prevention study

Intervention should be considered in postmenopausal women with bone mineral density (BMD) > or = 1 SD below the reference (T or Z score < -1). However, it is unclear when densitometry should be repeated. This study aimed at determining the need for repeat DXA within 5 years in untreated peri-/postmenopausal women to detect declines of T or Z score to below -1 with 85% confidence. A cohort of 925 healthy women (aged 51.2 +/- 2.9 years) were followed within the Danish Osteoporosis Prevention Study (DOPS) for 5 years without hormone-replacement therapy (HRT). DXA of spine, hip, and forearm was done at 0,1, 2, 3, and 5 years (Hologic QDR-1000/2000). The annual loss in SD units was 0.12 +/- 0.10 at the spine (1.3%), 0.10 +/- 0.09 at the femoral neck (1.2%), and 0.07 +/- 0.09 at the ultradistal (UD) forearm (1.0%). Accordingly, T scores below -1 developed earlier at the spine. The need for a future DXA scan to predict declines of T and Z scores below -1 depended strongly on baseline BMD. In subjects with a positive T score, the risk of developing T < -1 remained at <15% for 5 years at all measured sites. A new scan was needed after 1 year if the T score was below -0.5, and after 3 years if the T score was between 0 and -0.5. Slightly longer intervals apply if Z scores are used. Follow-up densitometry in untreated women should be individually targeted from baseline BMD rather than scheduled at fixed time intervals. An algorithm for planning repeat densitometry in perimenopausal women is provided.

Advanced glycation end products impair the scavenger function of rat hepatic sinusoidal endothelial cells

AIMS/HYPOTHESIS

We have previously reported that advanced glycation end products are eliminated from the circulation mainly by scavenger receptor-mediated uptake in hepatic sinusoidal endothelial cells. Our experiments showed that the degradation of AGE-modified protein after endocytosis in hepatic sinusoidal endothelial cells occurs slowly compared with that of other scavenger receptor ligands. The aim of this study was to investigate further the mechanism whereby AGE-modified protein affects the important scavenger function of hepatic sinusoidal endothelial cells.

METHODS

Primary cultures of hepatic sinusoidal endothelial cells were pre-incubated with unlabelled ligand, unbound ligand was washed off, and the endocytic capacity was measured by addition of radiolabelled ligand, and immune electron microscopy.

RESULTS

Pre-incubation with unlabelled AGE-modified bovine serum albumin reduced subsequent endocytosis of radiolabelled scavenger receptor ligands AGE-modified bovine serum albumin, formaldehyde-treated serum albumin, oxidized low density lipoprotein and acetylated low density lipoprotein by 50, 56, 32 and 20%, respectively. Non-scavenger receptor-mediated endocytosis was not affected by pre-exposure to AGE-modified protein. Pre-incubation with a number of non-AGE-ligands did not affect subsequent endocytosis via any of the major endocytosis receptors in hepatic sinusoidal endothelial cells. Incubation in fresh medium for 6 h after pre-exposure to AGE-modified protein almost completely restored normal scavenger receptor-mediated endocytic activity. Quantitative immune electron microscopy showed that the amount of a newly described scavenger receptor for AGE-modified protein is reduced after pre-incubation with AGE-modified protein. Subcellular fractionation showed that pre-incubation with AGE-modified protein delays intracellular transport of scavenger receptor ligands.

CONCLUSION/INTERPRETATION

Endocytosis of AGE-modified protein leads to loss of scavenger receptors and delayed intracellular transport in hepatic sinusoidal endothelial cells.