Mammalian target of rapamycin inhibitor dyslipidemia in kidney transplant recipients

The incidence, pathogenesis, consequences and treatment of mammalian target of rapamycin (mTOR) inhibitor dyslipidemia are not well described. We conducted a systematic review of randomized controlled trials reporting cholesterol and triglycerides in mTOR versus non-mTOR inhibitor immunosuppressive treatment regimens in kidney transplant recipients. All but one of 17 trials reported higher levels of cholesterol and triglycerides, or an increased prevalence of treatment with lipid-lowering agents. Approximately 60% of mTOR inhibitor-treated patients received lipid-lowering agents (2-fold higher than controls). There appeared to be little difference between dyslipidemias caused by sirolimus (14 trials) versus everolimus (3 trials). It was difficult to determine the extent to which declines in lipids over time posttransplant were due to lipid-lowering therapy, changes in doses and/or discontinuations of mTOR inhibitors. From the four trials that measured lipoproteins, it appeared that at least some of the increase in total cholesterol with mTOR inhibitors was due to increased low-density lipoprotein cholesterol. What direct or indirect effects mTOR inhibitors have on atherosclerotic cardiovascular disease in kidney transplant patients are unknown. However, in the absence of the necessary clinical trials, dyslipidemia should be managed, as it would be in nontransplant patients at high risk for cardiovascular disease.

Photosynthesis and respiration decline with light intensity in dominant and suppressed Eucalyptus globulus canopies

Within canopy gradients in light-saturated photosynthesis (A_max), foliar nitrogen ([N]_area) and leaf dark respiration (R₁₅) were studied in the canopies of dominant and suppressed trees within an even-aged (4-year-old) Eucalyptus globulus (Labill) stand in southern Tasmania. Despite being an even-aged stand growing in a relatively uniform environment with respect to nutrient and water availability, the stand exhibited considerable structural complexity. Diameter at 1.3 m ranged between 3 cm and 21 cm, trees average 12 m height and stand leaf area index was ~6 m² m^-2 leading to strong gradients in light availability. We were interested in understanding the processes governing canopy production in trees of contrasting dominance classes. Vertical gradients in photosynthesis and foliar respiration were studied within the canopies of dominant and suppressed trees during 2006 and 2007. A_max varied from ~18 μmol m^-2 s^-1 in the upper canopy to 3 μmol m^-2 s^-1 at lower canopy positions. On average, A_max were higher in the dominant trees than in the suppressed trees. However, at any given height, A_max were similar in suppressed and dominant trees and were strongly related to leaf nitrogen content. Dark respiration varied from ~1.4 μmol m^-2 s^-1 in the upper canopy to 0.2 μmol m^-2 s^-1 in the lower canopy positions. In contrast to the patterns for A_max, dark respiration rates in the suppressed trees were higher than dominant trees at similar canopy positions. Respiration rates were also strongly related to [N]_area and to A_max.

Mammalian target of rapamycin inhibitor dyslipidemia in kidney transplant recipients

The incidence, pathogenesis, consequences and treatment of mammalian target of rapamycin (mTOR) inhibitor dyslipidemia are not well described. We conducted a systematic review of randomized controlled trials reporting cholesterol and triglycerides in mTOR versus non-mTOR inhibitor immunosuppressive treatment regimens in kidney transplant recipients. All but one of 17 trials reported higher levels of cholesterol and triglycerides, or an increased prevalence of treatment with lipid-lowering agents. Approximately 60% of mTOR inhibitor-treated patients received lipid-lowering agents (2-fold higher than controls). There appeared to be little difference between dyslipidemias caused by sirolimus (14 trials) versus everolimus (3 trials). It was difficult to determine the extent to which declines in lipids over time posttransplant were due to lipid-lowering therapy, changes in doses and/or discontinuations of mTOR inhibitors. From the four trials that measured lipoproteins, it appeared that at least some of the increase in total cholesterol with mTOR inhibitors was due to increased low-density lipoprotein cholesterol. What direct or indirect effects mTOR inhibitors have on atherosclerotic cardiovascular disease in kidney transplant patients are unknown. However, in the absence of the necessary clinical trials, dyslipidemia should be managed, as it would be in nontransplant patients at high risk for cardiovascular disease.

Taxanes for the adjuvant treatment of early breast cancer: systematic review and economic evaluation

OBJECTIVES

To estimate the clinical effectiveness and cost-effectiveness of docetaxel and paclitaxel compared with non-taxane, anthracycline-containing chemotherapy regimens, for the adjuvant treatment of women with early-stage breast cancer.

DATA SOURCES

Major electronic databases were searched between October 2005 and February 2006.

REVIEW METHODS

A systematic review of the literature on adjuvant taxane versus anthracycline non-taxane chemotherapy for women with early breast cancer was undertaken. A mathematical model was developed to synthesise the available data on costs, disease-free survival and health-related quality of life (HRQoL) of patients receiving taxane-containing chemotherapy versus non-taxane-containing chemotherapy.

RESULTS

Eight of the 11 selected trials (six docetaxel and five paclitaxel) reported a significant improvement in disease-free survival (DFS) or time to recurrence (TTR) for taxanes over comparator regimens. Docetaxel was associated with more adverse events than paclitaxel, most notably febrile neutropenia. Taxanes produced cardiotoxicity, although this was not reported to be greater than for anthracycline comparator arms in all trials. Treatment-related deaths were uncommon. Where reported, all chemotherapy regimens caused HRQoL to deteriorate during treatment. Following treatment, there were no clinically significant differences between taxane and comparator treatment groups. There were few data available comparing licensed regimens of taxanes with chemotherapy regimens commonly used in the UK. The three trials selected as the basis for the economic analysis were those that used the taxanes in accordance with current UK marketing authorisation and had also reported in full. The estimated incremental cost-effectiveness ratio for docetaxel compared to FAC6, based on the BCIRG 001 study, is 12,000 pounds (7000-39,000 pounds) and for paclitaxel compared with Adriamycin/cyclophosphamide, based on the NSABP B28 and CALGB 9344 studies, is 43,000 pounds (16,000 pounds-dominated) and 39,000 pounds (12,000 pounds-dominated), respectively. However, the comparators used in these trials restrict the generalisability of the results, as they do not conform to current standard care in the UK, typically FEC6 and E4-CMF4. An exploratory indirect comparison shows that the benefits of taxane containing regimens compared to regimens in current use in the UK is subject to large uncertainty due to the lack of direct trial comparisons between these interventions. Assumptions regarding the benefits in the taxane arm after the trial follow-up period and the annual rate of recurrence in this period have the most significant influence on the ICER.

CONCLUSIONS

There is a large degree of heterogeneity in the evidence base for the effectiveness of taxane- compared with non-taxane-containing regimens in terms of the interventions, comparators and populations. Eight of the 11 trials providing effectiveness data reported a significant improvement in DFS or TTR for taxanes over comparator regimens. The remaining three trials found no significant differences between the groups in DFS/TTR. The cost-effectiveness results suggest that the cost per quality-adjusted life-year for taxane- compared with non-taxane-containing chemotherapy varies between 12,000 pounds and 43,000 pounds, depending on the taxane under consideration and the specific trial used as the basis of the analysis. However, the comparators used in these trials do not conform to current standard care in the UK. More research is needed, comparing taxanes used in line with their current UK marketing authorisation and with anthracycline-containing regimens commonly used in the UK. The on-going TACT trial is expected to provide useful data. There are currently few data on the effectiveness of taxanes for the over-70s. Further research is required into the long-term outcomes of taxane therapy, such as whether there are any long-term adverse events that significantly impact on overall survival or quality of life and whether the increases in DFS will translate into increases in overall survival.

Simultaneous liver-kidney transplantation: evaluation to decision making

Questions about appropriate allocation of simultaneous liver and kidney transplants (SLK) are being asked because kidney dysfunction in the context of liver failure enhances access to deceased donor organs. There is specific concern that some patients who undergo combined liver and kidney transplantation may have reversible renal failure. There is also concern that liver transplants are placed prematurely in those with end-stage renal disease. Thus to assure allocation of transplants only to those truly in need, the transplant community met in March 2006 to review post-MELD (model for end-stage liver disease) data on the impact of renal function on liver waitlist and transplant outcomes and the results of SLK.

Variation in anaesthesia for the laser treatment of retinopathy of prematurity—a survey of ophthalmologists in the UK

PURPOSE

Laser treatment for retinopathy of prematurity (ROP) may be associated with systemic stress for the infant. No national consensus on the optimum method of anaesthesia for the treatment of ROP currently exists. This study ascertains the anaesthetic practices employed for the treatment of ROP by ophthalmologists in the United Kingdom (UK), and also their attitudes towards these practices.

MATERIALS AND METHODS

A postal questionnaire was sent to 46 consultant ophthalmologists identified as performing treatment for ROP in the UK. The consultants were asked to estimate the annual number of babies with ROP that they treated with laser, what methods of anaesthesia they employed, for comments regarding the arrangements for, and types of anaesthesia employed and whether they believed that the neonatal stress response to laser treatment was associated with a significant risk of systemic complications.

RESULTS

In all, 35 (76%) questionnaires were returned. A total of 30 (86%) respondents reported performing laser treatment for ROP. Of these, 15 (50%) used general anaesthesia for all cases and 11 (37%) intravenous sedation combined with topical anaesthesia for all cases. Oral sedation combined with topical anaesthesia, rectal chloral hydrate and paracetamol combined with topical anaesthesia, intravenous ketamine combined with topical anaesthesia, and subtenon's local anesthesia were used by one (3%) respondent each. There were no ophthalmologists using subconjunctival or topical anaesthetic alone or treating without anaesthesia.

CONCLUSION

This survey reveals considerable variation in practice among UK ophthalmologists regarding the anaesthetic methods employed in the treatment of ROP, and their beliefs regarding the systemic stress associated with treatment.

Primary isolation of the bovine spongiform encephalopathy agent in mice: agent definition based on a review of 150 transmissions

In the epizootic of bovine spongiform encephalopathy (BSE) in Great Britain, the cattle in which a positive diagnosis was made numbered almost 180 000, but strain characterization was performed on only a very small sample of these cases. This report describes the results of BSE transmission to Prnp(a) mice from 150 transmission experiments at the Veterinary Laboratories Agency (VLA) over the last decade. These data, derived from a large sample of BSE-affected cattle, confirmed previous reports that show no evidence for diversity in BSE isolates. The agent was readily transmitted to mice, with a mean incubation period of 408 days in the RIII strain. Because the incubation period was related to the titre of the inoculum, it is not a reliable characteristic of strain type on primary isolation. Consistent neuropathological changes associated with infection by the BSE agent in RIII and C57Bl mice included focal vacuolation in the dorsal cochlear nuclei, vacuolation of the granule cell layer of the cerebellum, absence of lesions in the hippocampus and in the molecular layer of the cerebellum, and a fine particulate distribution of disease-specific PrP (demonstrated immunohistochemically), with few or no amyloid plaques. These features, together with the conventional lesion profile, will be of use in distinguishing the agents of BSE and scrapie in sheep.

The Value of Abdominal Examination in the Diagnosis of Abdominal Aortic Aneurysm

BACKGROUND

There is considerable variability in the reported value of clinical examination in the diagnosis of abdominal aortic aneurysms (AAA). This study aims to assess accuracy of abdominal examination by a doctor, a nurse and the patient in the diagnosis of AAA and whether this accuracy is related to the size of the aneurysm and/or the BMI of the patient.

METHODS

164 patients, 138 men and 26 women, median age 71 years, consented to participate in this prospective, single blind, controlled study. Thirty-nine patients attending for carotid duplex were used as controls. Abdominal examination was performed by a doctor and a nurse. Patients then performed self-examination.

RESULTS

Examination by a doctor, a nurse and the patient were similar in accuracy in diagnosing/excluding AAA which was directly related to AAA size and patient BMI. The Negative Predicted Value of abdominal examination exceeds 0.9 with AAA diameters > or =4 cm and the Positive Predictive Value exceeds 0.8 with AAA diameters > or =5 cm.

CONCLUSIONS

Abdominal examination by a doctor, a nurse and the patient is of value in the exclusion and diagnosis of significant AAA. It should be promoted and may represent a useful adjunct to population screening with ultrasound.

Capillary and arterial cerebral amyloid angiopathy in Alzheimer's disease: defining the perivascular route for the elimination of amyloid beta from the human brain

Accumulation of amyloid beta (Abeta) in the extracellular spaces of the cerebral cortex and in blood vessel walls as cerebral amyloid angiopathy is a characteristic of Alzheimer's disease (AD) and the ageing human brain. Studies in animals suggest that Abeta is eliminated from the brain either directly into the blood or along perivascular interstitial fluid drainage channels. The aim of the present study is to define the perivascular route for the drainage of Abeta from the human brain. Smears and paraffin sections of post-mortem cortical tissue from 17 cases of AD and from two controls were stained with thioflavin and for Abeta by immunohistochemistry. Histology and confocal microscopy showed that deposits of Abeta in the cortical parenchyma were continuous with Abeta in capillary walls but Abeta in artery walls was not in continuity with Abeta in brain parenchyma. Quantitative studies supported these observations. The results of this study suggest that when Abeta is eliminated from the extracellular spaces of the human brain by the perivascular route, it enters pericapillary spaces and from there drains along the walls of cortical arteries to leptomeningeal arteries. Factors such as overproduction of Abeta, entrapment of Abeta in drainage pathways and poor drainage of Abeta due to functional changes in ageing arteries might result in the failure of elimination of Abeta from the ageing brain and play a major role in the pathogenesis of AD. Such factors might affect therapies for AD that entail administration of anti-Abeta antibodies to eliminate Abeta from the human brain.

The effect of either a pre or post exercise stretch on straight leg raise range of motion (SLR-ROM) in females

This study examined the order effect of a hamstring muscle stretch and resisted hamstring exercises on straight leg raise range of movement (SLR-ROM), in a group of twenty females aged 20-34 years. The stretch was applied either immediately before or Immediately after a resisted hamstring exercise. Exercise significantly decreased SLR-ROM (p < 0.05) and stretching significantly increased SLR-ROM (p < 0.05). The overall change in SLR-ROM for the two groups showed that a significant increase in SLR-ROM was detected (at a low force level) in Group 1 subjects who performed exercise and then stretched. A non-significant increase in SLR-ROM was detected by the higher force level in Group 1 subjects. In contrast, Group 2 subjects (stretch then exercise) showed a non-significant reduction in SLR-ROM at both levels of force.

N-acyl-homoserine lactone inhibition of rhizobial growth is mediated by two quorum-sensing genes that regulate plasmid transfer

The growth of some strains of Rhizobium leguminosarum bv. viciae is inhibited by N-(3-hydroxy-7-cis tetradecenoyl)-L-homoserine lactone (3OH-C(14:1)-HSL), which was previously known as the small bacteriocin before its characterization as an N-acyl homoserine lactone (AHL). Tn5-induced mutants of R. leguminosarum bv. viciae resistant to 3OH-C(14:1)-HSL were isolated, and mutations in two genes were identified. These genes, bisR and triR, which both encode LuxR-type regulators required for plasmid transfer, were found downstream of an operon containing trb genes involved in the transfer of the symbiotic plasmid pRL1JI. The first gene in this operon is traI, which encodes an AHL synthase, and the trbBCDEJKLFGHI genes were found between traI and bisR. Mutations in bisR, triR, traI, or trbL blocked plasmid transfer. Using gene fusions, it was demonstrated that bisR regulates triR in response to the presence of 3OH-C(14:1)-HSL. In turn, triR is then required for the induction of the traI-trb operon required for plasmid transfer. bisR also represses expression of cinI, which is chromosomally located and determines the level of production of 3OH-C(14:1)-HSL. The cloned bisR and triR genes conferred 3OH-C(14:1)-HSL sensitivity to strains of R. leguminosarum bv. viciae normally resistant to this AHL. Furthermore, bisR and triR made Agrobacterium tumefaciens sensitive to R. leguminosarum bv. viciae strains producing 3OH-C(14:1)-HSL. Analysis of patterns of growth inhibition using mutant strains and synthetic AHLs revealed that maximal growth inhibition required, in addition to 3OH-C(14:1)-HSL, the presence of other AHLs such as N-octanoyl-L-homoserine lactone and/or N-(3-oxo-octanoyl)-L-homoserine lactone. In an attempt to identify the causes of growth inhibition, a strain of R. leguminosarum bv. viciae carrying cloned bisR and triR was treated with an AHL extract containing 3OH-C(14:1)-HSL. N-terminal sequencing of induced proteins revealed one with significant similarity to the protein translation factor Ef-Ts.

Mechanical ventilation for newborn infants with respiratory failure due to pulmonary disease

BACKGROUND

Before the 1960s newborn infants with severe lung disease, usually due to respiratory distress syndrome (RDS), had a very high mortality rate. Standard treatment consisted of supportive measures including supplemental oxygen and correction of metabolic acidosis. Mechanical ventilation (MV) was introduced in the 1960s to correct hypoxaemia and respiratory acidosis in infants who were likely to die. MV is now standard treatment for infants with severe RDS but the degree to which this made a contribution to the outcome of such infants compared with standard neonatal care, is uncertain.

OBJECTIVES

To evaluate the effects of the use of MV compared with no MV on mortality and morbidity in newborn infants with severe respiratory failure due to pulmonary disease.

SEARCH STRATEGY

Searches were last updated in March 2002 on the Cochrane Controlled Trials Register (Cochrane Library Issue 1, 2002), MEDLINE from 1966 and EMBASE from 1980. In order to detect trials that may not have been published in full, searches carried out of the Oxford Database of Perinatal Trials and for abstracts published by the Society for Pediatric Research (1967 to 2001) and the European Society for Pediatric Research 1970 to 1977. Experts were consulted with emphasis on those who were in active neonatal practice in the 1960s and 1970s when the majority of these trials were likely to have been done.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials in newborn infants with respiratory failure due to pulmonary disease evaluating the use of MV versus standard neonatal care without MV.

DATA COLLECTION AND ANALYSIS

The standard methods of the Cochrane Collaboration and its Neonatal Review Group were used. Two authors independently assessed eligibility, methodological quality of each trial and extracted the data. Additional information was obtained from all trial authors on methodology or data. The data were analysed using relative risk and risk difference and their 95% confidence intervals. A fixed effect model was used for meta-analyses.

MAIN RESULTS

The five trials reported on a total of 359 infants with RDS. In one study there is a higher neonatal mortality in the mechanical ventilation group [7/10 vs 1/10; RR 7.00 (1.04, 46.95)]. Overall any reported mortality is less frequent in the mechanical ventilation group with the upper 95% confidence limit on 1.00 [summary RR 0.86 (0.74, 1.00), RD -0.10 (-0.20, -0.01), NNT 10 (5, 100)]. In infants with a birth weight of 1 - 2 kg, no significant difference in mortality is found [summary RR for two trials 0.86 (0.70, 1.07)]. In infants with a birth weight of more than 2 kg, one study reports a significant reduction in mortality in the MV group compared with control [RR 0.67 (0.51, 0.86)]; overall for this birth weight group there is a significant reduction in mortality with MV in the two trials [summary RR 0.67 (0.52, 0.87), RD -0.27 (-0.45, -0.10), NNT 4 (2, 10)]. Any IVH at autopsy is not significantly different between the groups in any study or overall in four studies reporting on 202 infants who had an autopsy. Pneumothorax was reported in two studies of 275 infants and there is a non-significant trend towards an increase in the mechanical ventilation group [summary RR 2.75 (0.72, 10.45)].

REVIEWER'S CONCLUSIONS

When MV was introduced in the 1960s to treat infants with severe respiratory failure due to pulmonary disease, trials showed an overall reduction in mortality which was most marked in infants born with a birthweight of more than 2 kg. This review does not provide information to evaluate the relative benefits or harms of MV in the setting of modern perinatal care. In settings without modern neonatal care, the introduction of MV should ideally be evaluated in randomised controlled trials for its relative benefits, harms and costs.

Progress in the clinical application of immunosuppressive drugs in renal transplantation

Although only very few new immunosuppressive drugs have been approved over the past two decades, the introduction of each new drug has progressively reduced the incidence of acute rejection and raised hopes that there would be an increase in long-term allograft survival. It is now consistently possible to achieve acute rejection rates of between 10 and 20%, and in many studies the rate has fallen below 10%. This is important, as acute rejection is one of the most important factors reducing the long-term survival of the allograft as a consequence of the development of chronic allograft nephropathy. The availability of these new agents has allowed experimentation with diverse protocols that explore the possibility of reduced exposure to calcineurin inhibitors and corticosteroids. These include both 'avoidance' and 'withdrawal' protocols. The target of rapamycin inhibitors, sirolimus and everolimus, have extended this paradigm. It is possible, but not yet proved, that their antiproliferative effect on smooth muscle will retard the vascular remodelling characteristic of chronic allograft nephropathy, atherosclerosis and hypertension. This review concentrates on the current progress being made in clinical immunosuppression, and includes data presented at the Transplant 2001 meeting of the American Society of Transplantation and the American Society of Transplant Surgeons, held in May 2001.

Cyclosporine microemulsion- and mycophenolate mofetil-related lymphoid aggregates are not associated with acute rejection

BACKGROUND

Microemulsion cyclosporine, mycophenolate mofetil, and prednisone have become a common immunosuppressive protocol in renal transplantation. We identified lymphocytic infiltrates in transplant fine-needle aspirates and core biopsies from patients on this regimen without acute rejection clinically or by standardized morphological criteria and investigated this inflammatory response.

METHODS

Twenty-eight aspirates from 21 patients were included and assessed in the standard fashion. Nine core biopsies showing interstitial lymphocytic infiltration were evaluated with antibodies against CD3, CD4, CD8, CD20, CD30, CD56, KP1, and epithelial membrane antigen (EMA). Aspirates and biopsies were assessed for tubular cell major histocompatibility complex (MHC) class II antigen and for gamma-interferon (gamma-IFN), interleukin-4 (IL-4), and IL-10 mRNAs by reverse transcription-polymerase chain reaction.

RESULTS

Fifteen aspirates showed immune activation solely due to mature lymphocytes and monocytes; 13 had no immune activation. All aspirates were negative for MHC class II antigens. Of 6 activated aspirates assessed for gamma-IFN mRNA, 5 were negative. All 21 patients had similar clinical characteristics and recovered renal function without rejection treatment. The core biopsies had lymphocytes in 5-30% of the interstitium. The cells were 70-85% CD3+, with 50-85% CD4+, 3-10% KP1+, and rare cells CD56+. No T-cell activation was present (EMA- and CD30-). Seven biopsies were assessed and were negative for gamma-IFN mRNA; only one biopsy had weakly positive MHC class II staining. Two activated aspirates were negative for IL-4 and IL-10 mRNA, while three biopsies each contained IL-4 and IL-10 mRNAs.

CONCLUSIONS

Inactive interstitial lymphoid infiltrates are frequent in patients on this drug regimen and should not be interpreted as acute rejection, particularly in aspirate samples. These lymphocytes may play a role in long-term allograft acceptance.

Bacterial DNA ligases

DNA ligases join breaks in the phosphodiester backbone of DNA molecules and are used in many essential reactions within the cell. All DNA ligases follow the same reaction mechanism, but they may use either ATP or NAD+ as a cofactor. All Bacteria (eubacteria) contain NAD+-dependent DNA ligases, and the uniqueness of these enzymes to Bacteria makes them an attractive target for novel antibiotics. In addition to their NAD+-dependent enzymes, some Bacteria contain genes for putative ATP-dependent DNA ligases. The requirement for these different isozymes in Bacteria is unknown, but may be related to their utilization in different aspects of DNA metabolism. The putative ATP-dependent DNA ligases found in Bacteria are most closely related to proteins from Archaea and viruses. Phylogenetic analysis suggests that all NAD+-dependent DNA ligases are closely related, but the ATP-dependent enzymes have been acquired by Bacterial genomes on a number of separate occasions.