Revealing the quantum nature of the voltage-induced conductance changes in oxygen engineered yttrium oxide-based RRAM devices

In this work, the quasi-analog to discrete transition occurring in the current-voltage characteristic of oxygen engineered yttrium oxide-based resistive random-access memory (RRAM) devices is investigated in detail. In particular, the focus of our research is not on the absolute conductance values of this characteristic but on the magnitude of its conductance changes occurring during the reset process of the device. It is found that the detected changes correspond to conductance values predominantly of the order of the quantum unit of conductance G0 = 2e2/h, where e is the electron charge and h the Planck constant. This feature is observed even at conductance levels far above G0, i.e. where electron transport is seemingly diffusive. It is also observed that such behavior is reproducible across devices comprising yttrium oxide layers with different oxygen concentrations and measured under different voltage sweep rates. While the oxygen deficiency affects the total number of quantized conductance states, the magnitude of the changes in conductance, close to 1 G0, is invariant to the oxygen content of the functional layer.

Effects of acute aerobic exercise on fatmetabolism in pre- and postmenopausal women of comparable body mass index

Problem: With menopause, the risk of cardiovascular diseases (CVD) increases significantly. A possible molecular mechanism is an estrogen-related change in fat metabolism. Endurance training has been demonstrated to reduce the risk of CVD and to have an impact on fat metabolism (FM). This study aims to analyze the ability of pre- (preW) and postmenopausal women (postW) of comparable body mass index (BMI) to activate their FM during endurance training. Methods: 12 preW and 12 postW were included. Serum Triglyceride, LDL, HbA1C, estradiol and body composition data were determined. The respiratory quotient (RQ) was determined during moderate 30-minute exercise (60% of the 4 mmol threshold) on an ergometer. Results: While the BMI of preW and postW was comparable, body fat (BF) (p=0.001), lean body mass (LBM) (p=0.001) and abdominal girth (AG) (p=0.003) were significantly different. Significant group effects could also be identified in HbA1c (p=0.001), cholesterol (p=0.001) and LDL (p=0.000) serum concentrations. RQ decreased during 30 minutes of cycling in preW and increased in postW (p=0.010) over time. Discussion: The higher AG and BF and the lower LBM demonstrates the change in body composition in postW. An accumulation of fat, especially in the trunk region, goes along with an increase of CVD in postW, even with a normal BMI. Conclusion: It is evident that postW show altered lipid metabolism compared to preW. Key Words: Menopause, Cardiovascular Risk Factor, Aerobic Training, Metabolism

Comparison of Cyfra 21–1, Tpa and Tps in Lung Cancer, Urinary Bladder Cancer and Benign Diseases

Recently CYFRA 21–1, a new tumor marker measuring a fragment of cytokeratin 19, was introduced and proved to be suitable for therapy monitoring and follow-up of non-small cell lung carcinomas (NSCLC), in particular squamous cell carcinomas. Besides CYFRA 21–1 there are two other tumor markers, tissue polypeptide antigen (TPA) and tissue polypeptide-specific antigen (TPS), which also measure various cytokeratins in serum. In a retrospective study we investigated the clinical significance of these three cytokeratin markers in lung cancer and in carcinoma of the urinary bladder. For this purpose we investigated the sera of 50 healthy persons, 273 patients with various benign diseases, 218 patients with histologically proven lung cancer and 88 patients with carcinoma of the urinary bladder.

In a first step the specificity was established for the different reference groups and the cutoff values were fixed at a specificity of 95%. In lung cancer the single and combined sensitivities were calculated versus benign lung diseases (n = 58) as reference group. With single determinations CYFRA 21–1 proved to have the highest sensitivity in lung cancer in general (61%), in non-small cell lung carcinomas (64%), in squamous cell carcinomas (79%), in adenocarcinomas (54%) and in large cell carcinomas (65%). In small cell lung carcinomas (SCLC) NSE was confirmed to be the marker of choice (55%). With combined determinations a clear increase in sensitivity could only be reached in large cell carcinomas (CYFRA 21–1 + TPA: 77%) and in small cell carcinomas (CYFRA 21–1 + NSE: 62%). In cancer of the urinary bladder the sensitivities were established versus benign urological diseases (n = 73). CYFRA 21–1 showed with 38% true positive test results the highest sensitivity compared to TPA (27%) and TPS (23%).

From our investigations it was evident that TPA detects at least partially the same substance as CYFRA 21–1 (the sensitivities compared to the markers TPS, CEA, SCC and NSE were rather high, but not as high as for CYFRA 21–1) whereas TPS represents a completely different parameter of clinical chemistry (lowest number of true positive test results over the whole investigation), which apparently measures something completely different. These findings cleary correspond with the very recent results of immunoblotting comparing CYFRA 21–1, TPA and TPS.

Desmopressin testing in children with von Willebrand syndrome in haemostaseologic centers of Saxonia, Saxonia-Anhalt and Thuringia

The influence of desmopressin on hemostasis is mediated by the release of von Willebrand factor and of coagulation factor VIII from vascular endothelium. The necessity of testing desmopressin effectiveness on hemostasis is a matter of controversy and the performance of the test is not yet standardized. For this reason the desmopressin tests in 114 children with von Willebrand syndrome (type 1, n=98; type 2A, n=12; type 2M, n=2; type 2N, n=2) carried out in 7 paediatric haemostaseologic centers were retrospectively analyzed. The effectiveness of desmopressin was assessed using defined response criteria. As expected, the test performance showed a wide variation among the centers. In 99 children desmopressin was given intravenously as a short infusion at a dosage ranging from 0.25 to 0.41 μg/kg and in 15 intranasally at an absolute dose of 40 to 300 μg. The points of time for blood taking after desmopressin application ranged from 0.5 to 12 h. The absent desmopressin response in 7 patients (6%) and the partial response in 15 indicate the necessity of testing desmopressin effectiveness before the first therapeutic use. The application of desmopressin was well tolerated by the patients.

RNase 7 downregulates TH2 cytokine production by activated human T cells

BACKGROUND

The antimicrobial peptide (AMP) RNase 7 is constitutively expressed in the epidermis of healthy human skin and has been found to be upregulated in chronic inflammatory skin diseases such as atopic dermatitis and psoriasis. Activated T cells in lesional skin of patients with atopic dermatitis (AD) and psoriasis (PSO) might be directly exposed to RNase 7. In addition to their antimicrobial activity, immunoregulatory functions have been published for several AMPs. In this study, we investigated immunoregulatory effects of the antimicrobial peptide RNase 7 on activated T cells.

METHODS

Isolated human CD3+T cells were stimulated with RNase 7 and screened for possible effects by mRNA microarray analysis. The results of the mRNA microarray were confirmed in isolated CD4+T cells and in polarized TH2 cells using skin-derived native RNase 7 and a recombinant ribonuclease-inactive RNase 7 mutant. Activation of GATA3 was analysed by electrophoretic mobility shift assay.

RESULTS

Treatment of activated human CD4+T cells and TH2 cells with RNase 7 selectively reduced the expression of TH2 cytokines (IL-13, IL-4 and IL-5). Experiments with a ribonuclease-inactive recombinant RNase 7 mutant showed that RNase 7 ribonuclease activity is dispensable for the observed regulatory effect. We further demonstrate that CD4+T cells from AD patients revealed a significantly less pronounced downregulation of IL-13 in response to RNase 7 compared to healthy control. Finally, we show that GATA3 activation was diminished upon cultivation of T cells with RNase 7.

CONCLUSION

Our data indicate that RNase 7 has immunomodulatory functions on TH2 cells and decreases the production of TH2 cytokines in the skin.

Interleukin-10 is downregulated in mononuclear cells from endotoxin tolerant humans

It has been shown that induction of endotoxin tolerance results in a decreased potential to produce pro-inflammatory cytokines such as TNF or IL-1. The present study was carried out to examine the capacity of peripheral blood mononuclear cells (PBMC) from endotoxin tolerant humans to synthesize the anti-inflammatory cytokines IL-10 and TGFβ in response to endotoxin. Four individuals were rendered endotoxin tolerant by daily i.v. injections of endotoxin. PBMC were isolated before tolerance induction and on day 4 after the last endotoxin treatment. The cells were stimulated with endotoxin ex vivo and cytokines in culture supernatants were determined. PBMC isolated on day 4 of all of the volunteers showed decreased TNFα, IL-6 and IL-10 synthesis upon endotoxin treatment in vitro compared to pretolerant cells, while no differences occurred with regard to the amount of TGFβ formed by PBMC before and after tolerance induction. Furthermore, no changes were found in the expression of HLA-DR on PBMC after tolerance induction.

Endotoxin-tolerant mice produce an inhibitor of tumor necrosis factor synthesis

The present study was carried out to investigate a new aspect of early endotoxin tolerance in mice. Evidence was obtained that early endotoxin tolerance is associated with the production of an activity interfering with the synthesis of tumor necrosis factor α (TNFα). LPS-tolerant mice, challenged with lipopolysaccharide (LPS) had lower serum levels of TNF than LPS-treated normal animals. In parallel, whole blood of tolerant mice, treated with LPS ex vivo generated lower levels of TNF than blood of normal animals. Plasma obtained 30 min after challenge with LPS from tolerant mice was inhibitory for TNF synthesis in whole blood of normal mice ex vivo. This seems to be specific for tolerant mice, since plasma prepared from normal, endotoxin-challenged mice was devoid of inhibitory activity for TNF production. The TNF-inhibitor in plasma of endotoxin tolerant mice did not interfere with the cytotoxic activity of murine recombinant TNFα on WEHI cells. Heat treatment of plasma destroyed the activity.

Fish or n3-PUFA intake and body composition: a systematic review and meta-analysis

Obesity is a major public health issue and an important contributor to the global burden of chronic disease and disability. Studies indicate that fish and omega-3 polyunsaturated fatty acids (n3-PUFA) supplements may help prevent cardiovascular and metabolic diseases. However, the effect of fish oil on body composition is still uncertain, so we performed a systematic review of randomized controlled trials and the first meta-analysis on the association between fish or fish oil intake and body composition measures. We found evidence that participants taking fish or fish oil lost 0.59 kg more body weight than controls (95% confidence interval [CI]: -0.96 to -0.21). Treatment groups lost 0.24 kg m(-2) (body mass index) more than controls (-0.40 to -0.08), and 0.49 % more body fat than controls (-0.97 to -0.01). Fish or fish oil reduced waist circumference by 0.81 cm (-1.34 to -0.28) compared with control. There was no difference for fat mass and lean body mass. Further research is needed to confirm or refute our findings and to reveal possible mechanisms by which n3-PUFAs might reduce weight.

Depression in early adulthood: prevalence and psychosocial correlates among young Swiss men

QUESTION UNDER STUDY

Depression in young adults is common, but data from Switzerland are scarce. Our study gives a point prevalence estimate of depression in young Swiss men, and describes the association between depression and education, material and social resources, and job/school satisfaction.

METHODS

We used data from the cross-sectional Swiss Federal Surveys of Adolescents (ch-x) from 2010 to 2011 comprising 9,066 males aged between 18 and 25 years. Depression was assessed by means of self-reports using the Patient Health Questionnaire (PHQ-9). Persons were categorised into three groups: depression, subthreshold depression, and no depression. We assessed the relationship between depression and education, material and social resources, and satisfaction with job/school. Differences according to depression status were tested with chi-square tests for categorical variables and one-way analyses of variance for continuous variables.

RESULTS

Point prevalence of depression (3.60%) and subthreshold depression (3.62%) was high. Poor mental health was associated with lower education in young adults (p <0.001), and with their parents' education (p = 0.024). Social resources in persons with depression and subthreshold depression were substantially reduced (i.e., social support and satisfaction with social relations; both p <0.001). Young men with depression and subthreshold depression also reported a current lack of satisfaction with job/school (p <0.001).

CONCLUSIONS

Prevalence of (subthreshold) depression is high in young Swiss men. Depression at this age might result in a bad long-term prognosis owing to its association with low satisfaction with job/school and low self-efficacy. Interventions should especially consider the lower social resources of young men with depression.

Clock gene expression in the liver of streptozotocin-induced and spontaneous type 1 diabetic rats

Several investigations have shown a relation between diabetes and alterations of the liver circadian clock. We investigated the diurnal expression of clock genes and clock-controlled genes (CCGs) in 3-hour intervals for a 24-h period in the livers of male streptozotocin (STZ)-treated rats, male spontaneous type 1 diabetic LEW.1AR1-iddm (Iddm) rats, and Iddm rats treated for 10 days with insulin. Hepatic mRNA was extracted, and the relative expression of clock genes (Per1, Per2, Bmal1, Clock, Cry1), as well as CCGs (Dbp, E4bp4, RevErbα, Rorα, Pparγ), was analyzed by reverse transcription followed by real-time polymerase chain reaction. Diabetic STZ and Iddm rats, as well as insulin-substituted Iddm rats, exhibited a significant diurnal expression pattern of clock genes as determined by Cosinor analysis; however, the MESOR (midline estimating statistic of rhythm) of Bmal1, Per2, and Clock transcript expression was altered in Iddm and insulin-substituted Iddm rats. The hepatic expression of the CCGs Dbp and RevErbα revealed a diurnal rhythm in all investigated groups. Insulin administration to Iddm rats normalized the enhanced MESOR in the expression of Dbp, RevErbα, and E4bp4 to the levels of normoglycemic controls. Cosinor analysis indicated no diurnal rhythm of Pparγ expression in the livers of diabetic STZ or Iddm rats or in those of insulin-substituted Iddm rats. Also, insulin substitution could not reverse the decreased MESOR of Pparγ expression in Iddm rats. In consequence of the diabetic disease, changes in the expression of clock genes and CCGs suggest alterations in the hepatic peripheral clock mechanism.

GLUT4 in the endocrine pancreas--indicating an impact in pancreatic islet cell physiology?

The glucose transporter GLUT4 is well known to facilitate the transport of blood glucose into insulin-sensitive muscle and adipose tissue. In this study, molecular, immunohistochemical, and Western blot investigations revealed evidence that GLUT4 is also located in the mouse, rat, and human endocrine pancreas. In addition, high glucose decreased and insulin elevated the GLUT4 expression in pancreatic α-cells. In contrast, high glucose increased GLUT4 expression, whereas insulin led to a reduced expression level of the glucose transporter in pancreatic β-cells. In vivo experiments showed that in pancreatic tissue of type 2 diabetic rats as well as type 2 diabetic patients, the GLUT4 expression is significantly increased compared to the nondiabetic control group. Furthermore, type 1 diabetic rats exhibited reduced GLUT4 transcript levels in pancreatic tissue, whereas insulin treatment of type 1 diabetic animals enhanced the GLUT4 expression back to control levels. These data provide evidence for the existence of GLUT4 in the endocrine pancreas and indicate a physiological relevance of this glucose transporter as well as characteristic changes in diabetic disease.

Catecholamines are the key for explaining the biological relevance of insulin-melatonin antagonisms in type 1 and type 2 diabetes

In this paper, we analyze the biological relevance of melatonin in diabetogenesis. As has recently been demonstrated, melatonin decreases insulin secretion via specific melatonin receptor isoforms (MT1 and MT2) in the pancreatic β-cells. In addition, type 2 diabetic rats, as well as patients, exhibit decreased melatonin levels, whereas the levels in type 1 diabetic rats are increased. The latter effects were normalized by insulin substitution, which signifies that a specific receptor-mediated insulin-melatonin antagonism exists. These results are in agreement with several recent genome-wide association studies, which have identified a number of single nucleotide polymorphisms in the MTNR1B gene, encoding the MT2 receptor, that were closely associated with a higher prognostic risk of developing type 2 diabetes. We hypothesize that catecholamines, which decrease insulin levels and stimulate melatonin synthesis, control insulin-melatonin interactions. The present results support this assertion as we show that catecholamines are increased in type 1 but are diminished in type 2 diabetes. Another important line of inquiry involves the fact that melatonin protects the β-cells against functional overcharge and, consequently, hinders the development of type 2 diabetes. In this context, it is striking that at advanced ages, melatonin levels are reduced and the incidence of type 2 diabetes is increased. Thus, melatonin appears to have a protective biological role. Here, we strongly repudiate misconceptions, resulting from observations that melatonin reduces the plasma insulin level, that the blockage of melatonin receptors would be of benefit in the treatment of type 2 diabetes.

The insulin-melatonin antagonism: studies in the LEW.1AR1-iddm rat (an animal model of human type 1 diabetes mellitus)

AIMS/HYPOTHESIS

It is well documented that melatonin influences insulin secretion mediated by G-protein-coupled melatonin receptor isoforms MT1 and MT2, which are present in rat and human pancreatic islets, as well as in rat insulinoma cells. Recent investigations have proven that hyperinsulinaemic Goto-Kakizaki (GK) rats, which are a rat model of type 2 diabetic rats, and humans have decreased melatonin plasma levels, whereas a streptozotocin-induced rat model of diabetes developed reduced insulin levels combined with increased melatonin levels.

METHODS

Plasma levels of glucose, insulin and melatonin as well as RNA expression of pineal Aanat, Hiomt (also known as Asmt), insulin receptor, adrenoceptor β1 and the clock genes Per1 and Bmal1 (also known as Arntl) were determined in male and female LEW.1AR1-iddm rats as well as in insulin-substituted LEW.1AR1-iddm rats.

RESULTS

Severe hypoinsulinaemia in diabetic LEW.1AR1-iddm rats was associated with decreased body weight and increased melatonin plasma levels combined with mainly elevated expression of Aanat, Hiomt, pineal insulin receptor and adrenoceptor β1. The changes were normalised by insulin substitution. Diurnal profiles of plasma melatonin and of antagonistic clock genes Per1 and Bmal1 were maintained in diabetic and insulin-substituted rats.

CONCLUSIONS/INTERPRETATION

The assumed causal relation between elevated melatonin and reduced insulin levels in LEW.1AR1-iddm rats is supported by the observation that insulin substitution normalised these changes. Further support for this interpretation comes from the observation that in GK rats an increase of plasma insulin was combined with a decrease of plasma noradrenaline (norepinephrine), the most important activator of melatonin synthesis. These relationships between the noradrenergic and insulin pathway support the existence of melatonin-insulin antagonism.

Unmasking of a Recessive SCARF2 Mutation by a 22q11.12 de novo Deletion in a Patient with Van den Ende-Gupta Syndrome

Van den Ende-Gupta syndrome (VDEGS) is a congenital condition characterized by craniofacial and skeletal manifestations, specifically blepharophimosis, malar and maxillary hypoplasia, distinctive nose, arachnocamptodactyly, and long slender bones of the hands and feet. To date, only 24 patients have been described. It is generally thought that the syndrome is transmitted by an autosomal recessive mode of inheritance, although evidence for genetic heterogeneity has recently been presented. We report on a girl followed from birth up to 3 years of life with a set of peculiar minor anomalies, arachnocamptodactyly of hands and feet, characteristic of VDEGS in association with a 22q11.12 deletion. Recently, the VDEGS gene was mapped to the DiGeorge syndrome region on 22q11.2, and homozygous mutations in the SCARF2 gene were identified. We now report the first patient with VDEGS due to compound heterozygosity for the common 22q11.2 microdeletion and a hemizygous SCARF2 splice site mutation.

[Desmopressin testing in children with von Willebrand syndrome in haemostaseologic centers of Saxonia, Saxonia-Anhalt and Thuringia]

The influence of desmopressin on hemostasis is mediated by the release of von Willebrand factor and of coagulation factor VIII from vascular endothelium. The necessity of testing desmopressin effectiveness on hemostasis is a matter of controversy and the performance of the test is not yet standardized. For this reason the desmopressin tests in 114 children with von Willebrand syndrome (type 1, n=98; type 2A, n=12; type 2M, n=2; type 2N, n=2) carried out in 7 paediatric haemostaseologic centers were retrospectively analyzed. The effectiveness of desmopressin was assessed using defined response criteria. As expected, the test performance showed a wide variation among the centers. In 99 children desmopressin was given intravenously as a short infusion at a dosage ranging from 0.25 to 0.41 microg/kg and in 15 intranasally at an absolute dose of 40 to 300 microg. The points of time for blood taking after desmopressin application ranged from 0.5 to 12 h. The absent desmopressin response in 7 patients (6%) and the partial response in 15 indicate the necessity of testing desmopressin effectiveness before the first therapeutic use. The application of desmopressin was well tolerated by the patients.

Aphyllin, the first isoferulic acid glycoside and other phenolics from Tamarix aphylla flowers

The first glycosylated isoferulic acid, isoferulic acid 3-O-beta-glucopyranoside, together with the new phenolics, tamarixetin 3,3'-di-sodium sulphate and dehydrodigallic acid dimetyl ester have been characterized from a flower extract of Tamarix aphylla. The structures were established on the basis of spectral data. The extract exhibited a distinct radical scavenging effect and to improve the viability of human keratinocytes (HaCaT cells). Also, the known isoferulic acid and ferulic acid which have been determined to be the major components of the investigated extract by HPLC/ESI mass spectrometric screening have been separated, characterized and evaluated as active antioxidants and as cell activity stimulating agents as well.

Measurement of CD4+ T cells in point-of-care settings with the Sysmex pocH-100i haematological analyser

The decision to provide antiretroviral therapy to HIV-positive patients mainly depends on the CD4(+) T-cell count, with therapy indicated at a cut-off value of <350-200 CD4(+) T cells/microl blood. Monitoring patients is still a major problem in countries with limited resources where blood samples often have to be transported over long distances to regional referral centres in which the count can be performed on flow cytometers. We have evaluated a newly developed simple and inexpensive method for CD4(+) T-cell quantification. It is a variation of the Invitrogen T4 Quant kit, with manual isolation of nuclei from CD4(+) T cells and subsequent counting on the small haematology analyser pocH-100i, Sysmex. We have demonstrated that this new method is highly reproducible and gives stable and linear results over a wide range of CD4(+) T-cell concentrations. Method comparison to two different flow cytometers showed excellent correlation with concordances of about 93%. Overall, this method is rapid, easy to perform and offers a good reliable alternative to measurement by flow cytometry. The pocH-100i has the additional benefit of providing a complete blood count with a three-part white blood cell differential and software for patient data storage and handling.

Design Modifications and Optimization of a Commercially Available Knee Simulator

To determine the wear behavior of knee endoprostheses, implants are tested in knee simulators before being introduced to the market. Implants may undergo mechanical failure and wear debris is generated. The magnitude and morphology of this debris are determined to gain information about its biological reactivity. In this study, we describe the modifications made to the AMTI multistation knee simulator. The simulator is not capable to ensure a medially biased load distribution as required per ISO 14243, and therefore the usage of the simulator is limited. Thus, simulator modifications were made to implement a wear test as outlined in ISO 14243, and to improve both user-friendliness of operation and cost of simulation. In particular, this involved modifying the implant holders and controlling implant kinematics during the simulation. For component design, a 3D computer-aided design software was used. After the manufacturing of all components had been completed, the redesigned system was put into operation. In a final wear test, functionality and conformance with the ISO standard were tested for the modified simulator. After implementation of design modifications, it is possible to run wear tests with a medially biased load distribution according to ISO 14243.

Identification of RELMgamma, a novel resistin-like molecule with a distinct expression pattern

We have identified RELMgamma, a novel member of the resistin-like molecule/found in inflammatory zone (RELM/FIZZ) family in mice and rats. Microarray and real-time RT-PCR experiments revealed a repression of RELMgamma mRNA in nasal respiratory epithelium of cigarette smoke-exposed versus untreated rats. The analysis of the physiological tissue-specific expression revealed highest expression in hematopoietic tissues, suggesting a cytokine-like role for RELMgamma. RELMgamma is most closely related to RELMalpha/FIZZ1. Despite the high similarity, the expression properties of the two genes are clearly distinct. While RELMgamma (approved symbol retnlg) is expressed in rat white adipose tissue, minute to no expression of RELMalpha was detected in that system. Thus, previous reports analyzing RELMalpha expression in rat adipose tissue might have been influenced by cross-hybridization with RELMgamma. Finally we could demonstrate that white adipose tissue of mice shows strong RELMalpha expression but only low levels of RELMgamma, indicating a species-specific gene regulation.

Identification of RELMgamma, a novel resistin-like molecule with a distinct expression pattern

We have identified RELMgamma, a novel member of the resistin-like molecule/found in inflammatory zone (RELM/FIZZ) family in mice and rats. Microarray and real-time RT-PCR experiments revealed a repression of RELMgamma mRNA in nasal respiratory epithelium of cigarette smoke-exposed versus untreated rats. The analysis of the physiological tissue-specific expression revealed highest expression in hematopoietic tissues, suggesting a cytokine-like role for RELMgamma. RELMgamma is most closely related to RELMalpha/FIZZ1. Despite the high similarity, the expression properties of the two genes are clearly distinct. While RELMgamma (approved symbol retnlg) is expressed in rat white adipose tissue, minute to no expression of RELMalpha was detected in that system. Thus, previous reports analyzing RELMalpha expression in rat adipose tissue might have been influenced by cross-hybridization with RELMgamma. Finally we could demonstrate that white adipose tissue of mice shows strong RELMalpha expression but only low levels of RELMgamma, indicating a species-specific gene regulation.

Cessation of embolic signals after antithrombotic prevention is related to reduced risk of recurrent arterioembolic transient ischaemic attack and stroke

OBJECTIVES

To evaluate the reduction of embolic signals after the initiation of an antithrombotic secondary prevention in patients with recent arterioembolic stroke and to determine the predictive value of decreased microembolism on the risk of early stroke recurrence.

METHODS

Eighty six consecutive patients (55 men, 31 women; mean age 60.6 years) with a non-disabling arterioembolic ischaemic event in the anterior circulation within the last 30 days and a medium grade or high grade stenosis (> or =50%) of the ipsilateral carotid or middle cerebral artery underwent 1 hour transcranial Doppler monitoring as part of the admission examinations. Antithrombotic secondary prevention was started after completion of admission. Patients in whom embolic signals were detected underwent a second monitoring within 4 days (mean time 1.8 days). All patients were followed up prospectively to evaluate the relation between presence and persistence of embolic signals and the risk of recurrent transient ischaemic attack (TIA) and stroke within the next 6 weeks.

RESULTS

In 44 patients, embolic signals were detected at admission, a mean 5.4 days (range 0 to 21 days) after the initial event. Twenty five were positive for embolic signals also at the second monitoring, in 19 signals had ceased. Forty two patients without embolic signals at admission served as controls. During follow up, six ischaemic events (two stroke, three TIA, one amaurosis fugax) occurred in 25 patients with persisting embolic signals but none in 19 patients in whom signals had ceased by the second monitoring. One patient in the control group had a TIA. The incidence of a recurrent event was 0.45 per 30 patient-days if embolic signals persisted compared with 0.015 if signals could not be detected or had ceased. Persistence of embolic signals was an independent predictor of a recurrent TIA or stroke (adjusted odds ratio 37.0; 95% confidence interval (95% CI) 3.5 to 333; p<0.003). Cessation and decrease of embolic signals was associated with the administration of antiplatelet agents but not with anticoagulation with intravenous heparin (p<0.001).

CONCLUSIONS

Rapid cessation of embolic signals detected in patients with recently symptomatic arterial stenosis decreases increased risk of an early ischaemic recurrence. Effect of antithrombotic agents on embolic signals might serve as a marker for their efficacy on preventing stroke recurrence.

Microarray probe selection strategies

During recent years, DNA microarrays have become the method of choice to monitor the expression level of a large number of genes. Depending on the focus of the study and the method of microarray fabrication, a number of different strategies for probe selection may be most appropriate. One consideration concerns the length of the probe, ranging from some 25 residues used for oligonucleotide arrays to complete cDNAs. Unless resources are truly unlimited, an important decision to be made is the amount of effort to be put into the selection of genes and gene fragments. While high-throughput cDNA arraying projects usually will select from a collection of existing cDNA clones, smaller projects focusing on a number of selected genes can afford to selectively amplify fragments optimised for that purpose. This paper discusses the full scope of probe selection strategies, highlighting the problems that may be encountered in the various systems.