The Yale-Brown Obsessive Compulsive Scale. II. Validity

The development design and reliability of the Yale-Brown Obsessive Compulsive Scale have been described elsewhere. We focused on the validity of the Yale-Brown Scale and its sensitivity to change. Convergent and discriminant validity were examined in baseline ratings from three cohorts of patients with obsessive-compulsive disorder (N = 81). The total Yale-Brown Scale score was significantly correlated with two of three independent measures of obsessive-compulsive disorder and weakly correlated with measures of depression and of anxiety in patients with obsessive-compulsive disorder with minimal secondary depressive symptoms. Results from a previously reported placebo-controlled trial of fluvoxamine in 42 patients with obsessive-compulsive disorder showed that the Yale-Brown Scale was sensitive to drug-induced changes and that reductions in Yale-Brown Scale scores specifically reflected improvement in obsessive-compulsive disorder symptoms. Together, these studies indicate that the 10-item Yale-Brown Scale is a reliable and valid instrument for assessing obsessive-compulsive disorder symptom severity and that it is suitable as an outcome measure in drug trials of obsessive-compulsive disorder.

MR imaging detection of cerebral microbleeds: effect of susceptibility-weighted imaging, section thickness, and field strength

BACKGROUND AND PURPOSE

The emergence of cerebral microbleeds (CMB) as common MR imaging findings raises the question of how MR imaging parameters influence CMB detection. To evaluate the effects of modified gradient recalled-echo (GRE) MR imaging methods, we performed an analysis of sequence, section thickness, and field strength on CMB imaging properties and detection in subjects with cerebral amyloid angiopathy (CAA), a condition associated with microhemorrhage.

MATERIALS AND METHODS

Multiple MR images were obtained from subjects with probable CAA, with varying sequences (GRE versus susceptibility-weighted imaging [SWI]), section thicknesses (1.2-1.5 versus 5 mm), and magnetic field strengths (1.5T versus 3T). Individual CMB were manually identified and analyzed for contrast index (lesion intensity normalized to normal-appearing white matter signal intensity) and diameter. CMB counts were compared between 1.5T thick-section GRE and thin-section SWI for 3 subjects who underwent both protocols in the same scanning session.

RESULTS

With other parameters constant, use of SWI, thinner sections, and a higher field strength yielded medium-to-large gains in CMB contrast index (CI; Cohen d 0.71-1.87). SWI was also associated with small increases in CMB diameter (Cohen d <0.3). Conventional thick-section GRE identified only 33% of CMB (103 of 310) seen on thin-section SWI. Lesions prospectively identified on GRE had significantly greater CI and diameter measured on the GRE image than those not prospectively identified.

CONCLUSIONS

The examined alternatives to conventional GRE MR imaging yield substantially improved CMB contrast and sensitivity for detection. Future studies based on these techniques will most likely yield even higher prevalence estimates for CMB.

Synthesis and antifungal activity of (Z)-5-arylidenerhodanines

An efficient microwave-assisted synthesis of new (Z)-5-arylidenerhodanines under solvent-free conditions is described and their in vitro antifungal activity was evaluated following the CLSI (formerly NCCLS) guidelines against a panel of both standardized and clinical opportunistic pathogenic fungi. An analysis of the structure-activity relationship (SAR) along with computational studies showed that the most active compounds (F- and CF(3)-substituted rhodanines) possess high logP values and low polarizability. Mechanism-based assays suggest that active compounds neither would bind to ergosterol nor would produce a damage to the fungal membrane.

CD3delta couples T-cell receptor signalling to ERK activation and thymocyte positive selection

Thymocytes from mice lacking the CD3delta chain of the T-cell receptor (TCR), unlike those of other CD3-deficient mice, progress from a CD4- CD8- double-negative to a CD4+ CD8+ double-positive stage. However, CD3delta-/- double-positive cells fail to undergo positive selection, by which double-positive cells differentiate into more mature thymocytes. Positive selection is also impaired in mice expressing inactive components of the Ras/mitogen activated protein (MAP) kinase signalling pathway. Here we show that CD3delta-/- thymocytes are defective in the induction of extracellular signal-regulated protein kinase (ERK) MAP kinases upon TCR engagement, whereas activation of other MAP kinases is unaffected. The requirement for CD3delta maps to its extracellular or transmembrane domains, or both, as expression of a tail-less CD3delta rescues both ERK activation and positive selection in CD3delta-/- mice. Furthermore, the defect correlates with severely impaired tyrosine phosphorylation of the linker protein LAT, and of the CD3zeta chain that is localized to membrane lipid rafts upon TCR engagement. Our data indicate that the blockade of positive selection of CD3delta-/- thymocytes may derive from defective tyrosine phosphorylation of CD3zeta in lipid rafts, resulting in impaired activation of the LAT/Ras/ERK pathway.

Prognostic significance of blood pressure variability after thrombolysis in acute stroke

OBJECTIVE

To evaluate the impact of early blood pressure (BP) changes on diffusion-weighted imaging (DWI) lesion evolution and clinical outcome in patients with stroke treated with IV tissue plasminogen activator (tPA).

METHODS

We prospectively evaluated 80 patients with stroke with a documented middle cerebral artery occlusion treated with IV tPA. Multiple repeated systolic (SBP) and diastolic (DBP) BP measurements were obtained during 24 hours after admission. All patients underwent DWI, perfusion-weighted imaging, and magnetic resonance angiography before and 36-48 hours after thrombolysis. Recanalization was assessed on transcranial Doppler at 6 hours of stroke onset. NIH Stroke Scale scores were recorded at baseline and 24 hours. Modified Rankin Scale was used to assess 3-month outcome.

RESULTS

Recanalization occurred in 44 (55%) patients. BP variability, estimated as the SD of the mean, was associated with DWI lesion growth (r = 0.46, p = 0.0003 for SBP and r = 0.26, p = 0.02 for DBP), early clinical course (p = 0.06 for SBP and p = 0.01 for DBP), and 3-month outcome (p = 0.002 for SBP and 0.07 for DBP). However, the prognostic significance of BP changes differed depending on the presence of recanalization. SBP variability emerged as an independent predictor of DWI lesion growth (beta: 6.9; 95% CI, 3.2 to 10.7, p = 0.003) and worse stroke outcome (OR: 11; 95% CI: 2.2 to 56.1; p = 0.004) in patients without recanalization, but not in recanalized patients.

CONCLUSION

Blood pressure variability is associated with greater diffusion-weighted imaging lesion growth and worse clinical course in patients with stroke treated with IV tissue plasminogen activator. However, its impact varies depending on the occurrence of early recanalization after thrombolysis.

Impaired visual evoked flow velocity response in cerebral amyloid angiopathy

OBJECTIVE

Animal models of cerebral amyloid angiopathy (CAA) exhibit abnormal vascular reactivity. We determined whether vascular reactivity, measured by transcranial Doppler ultrasound (TCD), is reduced in humans with CAA.

METHODS

Cases were recruited from an established prospective study of CAA. Healthy controls were recruited from a study of normal aging. Evoked mean flow velocity increase in the posterior cerebral artery (PCA) was measured while subjects viewed a flashing alternating checkerboard stimulus. In a separate but partially overlapping cohort we measured the mean flow velocity increase in the middle cerebral artery (MCA) while subjects inhaled carbon dioxide.

RESULTS

The visual evoked mean flow velocity increase was 8.0 +/- 6.1% in CAA (n = 11) compared to 17.4 +/- 5.7% in controls (n = 9, p = 0.002). The PCA pulsatility index, a marker of distal vascular resistance, was higher in CAA (CAA 1.35 +/- 0.35, control 1.04 +/- 0.14, p = 0.03). Among CAA subjects, lower visual evoked mean flow velocity increase was associated with a higher number of hemorrhages seen on MRI (r = -0.87, p = 0.0005) and higher MRI white matter hyperintensity volume (r = -0.67, p = 0.02). The MCA response to carbon dioxide did not differ between CAA and control in 20 subjects (9 CAA, 11 control, p = 0.54).

CONCLUSIONS

Cerebral amyloid angiopathy (CAA) was associated with decreased vascular reactivity in response to visual stimulation, possibly reflecting the occipital predilection of the disease. The association of posterior cerebral artery (PCA) evoked flow velocity response with elevated PCA pulsatility index and MRI markers of small vessel disease suggests that abnormal PCA evoked flow velocity in CAA is caused by pathology of the distal resistance vessels.

Plasma d-dimer predicts poor outcome after acute intracerebral hemorrhage

OBJECTIVE

To investigate if systemic d-dimer activation occurs after acute intracerebral hemorrhage (ICH) and to study its influence on clinical outcome.

METHODS

The authors determined plasma baseline d-dimer in 98 consecutive acute (<24 hours) ICH patients. Glasgow Coma Scale and NIH Stroke Scale scores were recorded to assess neurologic status on baseline and follow-up visits (24 hours, 48 hours, 7th day, and 3rd month). They also determined the d-dimer temporal profile at follow-up visits in a subgroup of 21 patients. ICH volume was measured on baseline and follow-up CT scans. Early neurologic deterioration (END) and mortality during the 1st week were recorded.

RESULTS

ICH patients showed higher plasma d-dimer level than reference laboratory values at baseline (1,780 vs 360 ng/mL; p = 0.013) and 3 months after ICH onset (1,530 vs 470 ng/mL; p = 0.013). The d-dimer level was related to baseline ICH volume (r = 0.23, p = 0.049) and to the presence of intraventricular (2,370 vs 1,360 ng/mL; p = 0.019) or subarachnoid (4,180 vs 1,520 ng/mL; p = 0.001) extension. Nearly one-fourth of patients presented END, and 20% died as a result of ICH. As predictors of END, the authors identified d-dimer level >1,900 ng/mL (odds ratio [OR] 4.5, 95% CI 1.03 to 20.26, p = 0.045) and systolic blood pressure >182 mm Hg (OR 6.8, 95% CI 1.25 to 36.9, p = 0.026). Moreover, ICH volume >30 mL (OR 19.13, 95% CI 2.06 to 177, p = 0.009) and d-dimer levels >1,900 ng/mL (OR 8.75, 95% CI 1.41 to 54.16, p = 0.020) emerged as independent predictors of mortality.

CONCLUSION

Increased plasma d-dimer level following acute intracerebral hemorrhage is associated with early neurologic deterioration and poor outcome.

A broad molecular phylogeny of ciliates: identification of major evolutionary trends and radiations within the phylum

The cellular architecture of ciliates is one of the most complex known within eukaryotes. Detailed systematic schemes have thus been constructed through extensive comparative morphological and ultrastructural analysis of the ciliature and of its internal cytoskeletal derivatives (the infraciliature), as well as of the architecture of the oral apparatus. In recent years, a consensus was reached in which the phylum was divided in eight classes as defined by Lynn and Corliss [Lynn, D. H. & Corliss, J. O. (1991) in Microscopic Anatomy of Invertebrates: Protozoa (Wiley-Liss, New York), Vol. 1, pp. 333-467]. By comparing partial sequences of the large subunit rRNA molecule, and by using both distance-matrix and maximum-parsimony-tree construction methods (checked by boot-strapping), we examine the phylogenetic relationships of 22 species belonging to seven of these eight classes. At low taxonomic levels, the traditional grouping of the species is generally confirmed. At higher taxonomic levels, the branching pattern of these seven classes is resolved in several deeply separated major branches. Surprisingly, the first emerging one contains the heterotrichs and is strongly associated with a karyorelictid but deeply separated from hypotrichs. The litostomes, the oligohymenophorans, and the hypotrichs separate later in a bush-like topology hindering the resolution of their order of diversification. These results show a much more ancient origin of heterotrichs than was classically assumed, indicating that asymmetric, abundantly ciliated oral apparatuses do not correspond to "highly evolved" traits as previously thought. They also suggest the occurrence of a major radiative explosion in the evolutionary history of the ciliates, yielding five of the eight classes of the phylum. These classes appear to differ essentially according to the cytoskeletal architecture used to shape and sustain the cellular cortex (a process of essential adaptative and morphogenetic importance in ciliates).

Structural analysis of inhibitor binding to human carbonic anhydrase II

X-ray crystal structures of carbonic anhydrase II (CAII) complexed with sulfonamide inhibitors illuminate the structural determinants of high affinity binding in the nanomolar regime. The primary binding interaction is the coordination of a primary sulfonamide group to the active site zinc ion. Secondary interactions fine-tune tight binding in regions of the active site cavity >5 A away from zinc, and this work highlights three such features: (1) advantageous conformational restraints of a bicyclic thienothiazene-6-sulfonamide-1,1-dioxide inhibitor skeleton in comparison with a monocyclic 2,5-thiophenedisulfonamide skeleton; (2) optimal substituents attached to a secondary sulfonamide group targeted to interact with hydrophobic patches defined by Phe131, Leu198, and Pro202; and (3) optimal stereochemistry and configuration at the C-4 position of bicyclic thienothiazene-6-sulfonamides; the C-4 substituent can interact with His64, the catalytic proton shuttle. Structure-activity relationships rationalize affinity trends observed during the development of brinzolamide (Azopt), the newest carbonic anhydrase inhibitor approved for the treatment of glaucoma.

The gender gap in stroke: a meta-analysis

Several studies have indicated that gender differences might exist in stroke.

OBJECTIVES AND METHODS

Our goal was to perform a comprehensive meta-analysis in order to evaluate and quantify stroke gender disparities through a systematic search of relevant articles published up to October 2009 and addressing gender related differences in ischemic stroke risk factors, stroke subtype and severity, diagnostic tests, and acute phase and secondary prevention treatments.

RESULTS

Forty-five articles were included in the analysis, representing a total of 673,935 patients. Women were globally older than men (+5.2 years) and suffered more hypertension (P = 0.017) and atrial fibrillation (P < 0.001), although they were less likely to drink alcohol (P < 0.001), smoke cigarettes (P < 0.001), present hyperlipidemia (P = 0.033) or diabetes (P = 0.003) than men. Baseline stroke severity was not different between genders. Women suffered more cardioembolic strokes, while men had more atherothrombotic strokes. Moreover, women were less likely to receive stroke-related treatments, such as antiplatelets (P < 0.001), statins (P < 0.001), and tPA (P < 0.001) than men. Although meta-regression did not identify age or stroke etiology as sources of heterogeneity, caution should be taken as that analysis was possible only for gender differences in secondary prevention with antiplatelets because of limited data for other end points.

CONCLUSIONS

Gender differences have been identified on the risk factors profile and diagnostic and therapeutic management of patients with ischemic stroke. Active measures should thus be taken to avoid bias in clinical practice.

Mirtazapine substitution in SSRI-induced sexual dysfunction

BACKGROUND

Sexual side effects are a common and bothersome reaction to selective serotonin reuptake inhibitors (SSRIs), frequently leading to cessation of treatment. Mirtazapine, an alpha2-adrenoceptor and serotonin-2/3 receptor antagonist, appears to cause few sexual problems.

METHOD

Nineteen patients (12 women and 7 men), with SSRI-induced sexual dysfunction who were in remission from major depressive disorder (total Hamilton Rating Scale for Depression [HAM-D] score < or = 10), were switched to open-label mirtazapine for up to 6 weeks. Mirtazapine was titrated from 7.5 mg to 45 mg daily, as tolerated. Sexual functioning was measured weekly with the Arizona Sexual Experiences Scale (ASEX), and depression was measured weekly with the HAM-D.

RESULTS

Eleven patients (58%) had a return of normal sexual functioning (mean +/- SD ASEX score = 12+/-3), and another 2 (11%) reported significant improvement in sexual functioning (mean ASEX score reduced from 24+/-1 to 20+/-0). All nineteen patients maintained their antidepressant response (HAM-D score after 6 weeks of mirtazapine = 6+/-3). The most commonly reported side effects (using moderate/severe rating on a symptom checklist) were initial sedation (N = 3), irritability (N = 6), and muscle soreness and stiffness (N = 3). Weight gain of 10 to 20 lb (4.5-9 kg) was seen in 3 patients (2 women and 1 man).

CONCLUSION

Mirtazapine is an effective antidepressant for many patients experiencing SSRI-induced sexual dysfunction.

A panel of biomarkers including caspase-3 and D-dimer may differentiate acute stroke from stroke-mimicking conditions in the emergency department

BACKGROUND AND AIMS

At present, a rapid and widely available diagnostic test for stroke remains elusive. The aim of this study was to examine the predictive value of a panel of blood-borne biochemical markers for stroke diagnosis.

DESIGN

Consecutive patients with strokes or stroke-mimicking conditions (mimics) were evaluated within 24 h from symptom onset (915 strokes and 90 mimics). Blood samples were analysed by enzyme-linked immunosorbent assay for C-reactive protein, d-dimer, soluble receptor for advanced glycation end products (sRAGE), metalloproteinase 9 (MMP-9), S100B, brain natriuretic peptide, caspase-3, neurotrophin-3, chimerin and secretagogin.

RESULTS

The main independent predictors of stroke versus mimics were caspase-3 >1.96 ng mL(-1) [odds ratio (OR) = 3.32; 95% confidence interval (CI) 1.88-5.88, P < 0.0001], d-dimer >0.27 μg mL(-1) (OR = 2.97; 95% CI 1.72-5.16, P = 0.0001), sRAGE >0.91 ng mL(-1) (OR = 2.19; 95% CI 1.26-3.83, P = 0.006), chimerin <1.11 ng mL(-1) (OR = 0.4; 95% CI 0.19-0.81, P = 0.011), secretagogin <0.24 ng mL(-1) (OR = 0.51; 95% CI 0.27-0.97, P = 0.041) and MMP-9 > 199 ng mL(-1) (OR = 1.66; 95% CI 1.01-2.73, P = 0.046). The model's predictive probability of stroke when the six biomarkers are above/below these cut-off levels was 99.01%. The best combination of biomarkers in the model was caspase-3 and d-dimer. Moreover, a model developed for samples obtained within the first 3 h showed high sensitivity (Se) and specificity (Sp) (threshold at 25th percentile: Se 0.87, Sp 0.55; threshold at 75th percentile: Se 0.28, Sp 0.99).

CONCLUSIONS

A combination of biomarkers including caspase-3 and d-dimer appears to be the most promising to achieve a rapid biochemical diagnosis of stroke. If replicated, this approach could be used as a tool for urgent referral of stroke patients to hospitals in which acute treatments are available.

In-hospital stroke: a multi-centre prospective registry

BACKGROUND

in-hospital strokes (IHS) are relatively frequent. Avoidable delays in neurological assessment have been demonstrated. We study the clinical characteristics, neurological care and mortality of IHS.

METHODS

multi-centre 1-year prospective study of IHS in 13 hospitals. Demographic and clinical characteristics, admission diagnosis, quality of care, thrombolytic therapy and mortality were recorded.

RESULTS

we included 273 IHS patients [156 men; 210 ischaemic strokes (IS), 37 transient ischaemic attacks (TIA) and 26 cerebral haemorrhages]. Mean age was 72 ± 12 years. Cardiac sources of embolism were present in 138 (50.5%), withdrawal of antithrombotic drugs in 77 (28%) and active cancers in 35 (12.8%). Cardioembolic stroke was the most common subtype of IS (50%). Reasons for admission were programmed or urgent surgery in 70 (25%), cardiac diseases in 50 (18%), TIA or stroke in 30 (11%) and other medical illnesses in 71 (26%). Fifty-two per cent of patients were evaluated by a neurologist within 3 h of stroke onset. Thirty-three patients received treatment with tPA (15.7%). Thirty-one patients (14.7%) could not be treated because of a delay in contacting the neurologist. During hospitalization, 50 patients (18.4%) died, 41 of them because of the stroke or its complications.

CONCLUSIONS

cardioembolic IS was the most frequent subtype of stroke. Cardiac sources of embolism, active cancers and withdrawal of antithrombotic drugs constituted special risk factors for IHS. A significant proportion of patients were treated with thrombolysis. However, delays in contacting the neurologist excluded a similar proportion of patients from treatment. IHS mortality was high, mostly because of stroke.

Isolation and characterization of libraries of monoclonal antibodies directed against various forms of tubulin in Paramecium

Ciliates are very good models for studying post-translationally generated tubulin heterogeneity because they exhibit highly differentiated microtubular networks in combination with reduced genetic diversity. We have approached the analysis of tubulin heterogeneity in Paramecium through extensive isolation and characterization of monoclonal antibodies using various antigens and several immunization protocols. Eight monoclonal antibodies and 10 hybridoma supernatants were characterized by: i) immunoblotting on ciliate and pig brain tubulins as well as on peptide maps of Paramecium axonemal tubulin; ii) immunoblotting on ciliate tubulin fusion peptides generated in E coli, a procedure which allows in principle to discriminate antibodies that are directed against tubulin sequence (reactive on fusion peptides) from those directed against a post-translational epitope (non-reactive); and iii) immunofluorescence on Paramecium, 3T3 and PtK2 cells. Twelve antibodies labeled all microtubules in Paramecium cells and were found to be directed against tubulin primary sequences (nine of them being located in the alpha N-terminal domain, one in the beta C-terminal one, and two in alpha and beta central stretches). The remaining ones decorated only a specific subset of microtubules within the cell and were presumably directed against post-translational modifications. Among these, three antibodies are directed against an N-terminal acetylated epitope of alpha-tubulin whereas the epitopes of three other ones (TAP 952 degrees, AXO 58 and AXO 49 degrees) apparently correspond to still unidentified post-translational modifications, located in the C-terminal domain of both alpha- and beta-tubulins. The AXO 49 degrees specificity is similar to that of a previously described polyclonal serum raised against Paramecium axonemal tubulin [2]. The results are discussed in terms of identification and accessibility of the epitopes and immunogenicity of ciliate tubulin with reference to mammalian and ciliate tubulin sequences.

Treatment of the male with follicle-stimulating hormone in intrauterine insemination with husband's spermatozoa: a randomized study

We have examined the potential of follicle-stimulating hormone (FSH) therapy for the male to improve pregnancy rates in intrauterine insemination (IUI) with husband's spermatozoa. A prospective randomized trial was performed in 148 couples undergoing IUI because of male subfertility. In the treatment group, 150 IU FSH were administered to the husbands, either i.m. or s.c., three times a week, starting 3 months before the beginning of IUI cycles and maintained until the fifth IUI cycle. In the control group no treatment was given. FSH therapy did not change semen parameters. The pregnancy rate per cycle was 13.47% in the FSH group versus 10.07% in the non-FSH group; the pregnancy rate per woman was 44.38% in the FSH group versus 37.18% in the non-FSH group. Although the pregnancy rate increase was > 30% per cycle and > 20% per woman, statistical significance was not achieved. The cumulative pregnancy rate was 59.20% in the FSH group versus 42.91% in the non-FSH group. The pregnancy rate outside the IUI cycle was 14.70% (10/68) in the FSH group versus 2.5% (2/80) in the non-FSH group, the difference being statistically significant. In conclusion, a non-significant trend towards higher pregnancy rates in IUI was observed in the FSH group.

Microtubule diversity in ciliated cells: evidence for its generation by post-translational modification in the axonemes of Paramecium and quail oviduct cells

The diversity of microtubular networks was analyzed in quail oviduct and in Paramecium cells using conventional and confocal immunofluorescence as well as pre- and post-embedding EM immunocytochemistry with a variety of anti-tubulin antibodies. The 6-11B-1 monoclonal antibody, specific for the post-translational acetylation of Lys 40 of alpha-tubulin, and a polyclonal antibody raised against Paramecium axonemal tubulin (anti-PA tubulin antibody) both decorated stable microtubular arrays in Paramecium ie ciliary axonemes and a set of microtubular bundles associated with the cortex, suggesting that the two antibodies may be directed against the same epitope. However, several differences in the immunocytological patterns yielded by each antibody on the two cell types were evident. For example, in quail, as in all other Metazoa, the anti-PA tubulin antibody only decorated axonemes enclosed in normal ciliary membrane while it was unreactive on cytoplasmic tubulins. Immunoblotting of peptide maps of axonemal tubulins demonstrated that the epitopes of the two antibodies were indeed completely different. Double immunolabelling of dividing paramecia using a universal anti-tubulin antibody and the anti-PA tubulin one revealed that all newly assembled microtubular arrays were first detected by the universal antibody and, only shortly afterwards, by the anti-PA tubulin one. This provided a strong indication that the anti-PA tubulin antibody is directed against a post-translational modification taking place on already assembled microtubules (MTs) (as previously known to be the case for acetylation and detyrosination). In taxol-treated quail cells undergoing ciliogenesis, massive assembly of MTs and even axonemes occurred in the cytoplasm. These MTs were not decorated by the anti-PA tubulin antibody however, suggesting that in Metazoa the post-translational modification can only take place within the ciliary lumen. The present work provides one further mechanism for generating MT immunological and biochemical diversity post-translationally; this may account for the high multiplicity of tubulin isoforms observed in ciliates which contain very little if any genetic diversity of tubulin genes.

Rho regulates T cell receptor ITAM-induced lymphocyte spreading in an integrin-independent manner

T cell receptor (TCR) engagement increases integrin-mediated adhesion to APC, resulting in the stabilization of the T cell : APC interaction and the close apposition of the two cell membranes. Here we show that engagement of either the TCR or CD3 chimeras with immobilized antibodies causes the rapid spreading of T cells in an integrin-independent fashion. This effect concurs with the polymerization of the actin cytoskeleton and is dependent on the integrity of the immunoreceptor tyrosine-based activation motifs of the CD3 subunits. Expression of a dominant negative mutant of RhoA, as well as the Rho-specific inhibitor C3 toxin, abolished TCR-induced spreading. In contrast, constitutively active or dominant negative forms of Rac and Cdc42 did not affect cell spreading. We conclude that signals emanating from the TCR can directly induce T cell spreading, independently of integrins, and via a Rho-dependent reorganization of the actin cytoskeleton.

Antidepressants and the brain

The pathophysiology and effects of antidepressants in the brain are still poorly understood. While it is generally accepted that increasing the levels of monoamine in the brain is an effective way to alleviate depression, the precise neurobiological mechanisms are unclear. The evidence that monoamine function is impaired in individuals with depression is largely indirect. However, the neurotransmitter depletion model allows a more direct investigation of the role of the monoamines. In this model, tryptophan depletion is used to lower levels of serotonin and alpha-methylparatyrosine is used to induce catecholamine depletion in the brain. Studies have shown that such depletion transiently reverses antidepressant responses in the majority of patients, the response being dependent on the type of antidepressant used. However, depletion in unmedicated patients with depression did not worsen the depressive symptoms, neither did it cause depression in healthy subjects with no history of mental illness. The cause(s) of depression therefore appears to be more complex than simply a reduction in levels of monoamine or diminished function in these systems. The pathophysiology of depression may relate to dysfunction in brain areas modulated by monoamine systems. Antidepressant drugs may mediate their effects by causing adaptive changes in neurones localised in these brain areas.

C-reactive protein predicts further ischemic events in transient ischemic attack patients

BACKGROUND AND PURPOSE

Although patients with transient ischemic attack (TIA) experience cardiovascular events frequently, strong clinical predictors of recurrence are lacking. High-sensitivity C-reactive protein (hs-CRP) has been shown to be a powerful predictor of future first-ever and recurrent coronary and cerebral ischemic events. We aimed to investigate the relationship between hs-CRP and the risk of further ischemic events in TIA patients.

METHODS

High-sensitivity C-reactive protein level was determined <24 h after symptom onset among 135 consecutive TIA patients and stroke recurrence or any new vascular event was recorded during 1 year follow-up period.

RESULTS

A total of 38 (28.1%) patients experienced an end point event: 28 (20.7%) cerebral ischemic events, six (4.4%) heart ischemic events, four (3%) peripheral arterial disease, and nine (6.7%) vascular deaths. Cox proportional hazards multivariate analyses identified age [hazard ratio (HR) 1.07, 95% confidence interval (CI) 1.01-1.12, P = 0.01], large-artery occlusive disease (HR 2.73, 95% CI 1.16 to 6.41, P = 0.02) and hs-CRP> 4.1 mg/l (HR 2.81, 95% CI 1.12-7.10, P = 0.03) as independent predictors of stroke. Moreover, age (HR 1.05, 95% CI 1.01-1.10, P = 0.02), large-artery occlusive disease (HR 3.12, 95% CI 1.48-6.58, P < 0.01), coronary disease (HR 2.39, 95% CI 1.11-5.16, P = 0.03), and hs-CRP> 4.1 mg/l (HR 2.71, 95% CI 1.16-6.30, P = 0.02) were also independent predictors of any vascular event.

CONCLUSIONS

High-sensitivity C-reactive protein serum level predicts further ischemic events following TIA. Routine CRP measurement might be a useful tool for identifying high-risk TIA patients in order to plan aggressive diagnostic protocols and prevention therapies.

Validation of the n-alkane technique to estimate intake, digestibility, and diet composition in sheep consuming mixed grain:roughage diets

The usefulness of the n-alkane technique to estimate intake, digestibility, and diet composition in sheep fed mixed diets was tested in an experiment with 16 ewes consuming 4 different proportions of barley grain and straw ranging from 15:85 to 60:40. Two cases were considered: (1) straw as one component or (2) straw separated into leaves and stems. The relationship between estimated (Y) and observed (X) proportion of grain in the diet was highly significant (1: Y = 0.2355 + 0.9945X, r2 = 0.9999; 2: Y = –2.472 + 1.0063X, r2 = 0.9999). Actual intake was overestimated in (1) by 3.43–12.40%, the largest discrepancies corresponding to the lowest proportions of grain. In (2) actual intake was either overestimated (2.69%) or underestimated (5.38–6.85%), without a clear effect of the diet. A similar pattern was observed for digestibility, which was overestimated in (1) by 1.65–9.59% and overestimated, (by 2.07%) or underestimated (by 3.80–4.62%) in (2). Due to the small discrepancies between observed and estimated values, it may be concluded that the n-alkane technique might be a valid method for estimating intake, digestibility, and diet composition in sheep consuming mixed diets, for the two latter provided that faecal recovery of individual n-alkanes is calculated with enough accuracy.

Brain natriuretic peptide is associated with worsening and mortality in acute stroke patients but adds no prognostic value to clinical predictors of outcome

BACKGROUND

At the present time, the determination of the outcome of stroke patients is based on the analysis of clinical and neuroimaging data. The use of prognostic blood biomarkers could aid in decision-making processes, e.g. admitting patients to specialized stroke units. Although the prognostic role of natriuretic peptides has been studied in heart failure and coronary diseases, the value of brain natriuretic peptide (BNP) is less known within the field of strokes.

OBJECTIVE

We aimed to study the relationship between plasma levels of BNP and acute neurological worsening or mortality after stroke in a large cohort of patients (investigating both ischemic and hemorrhagic disease).

METHODS

Consecutive stroke patients (ischemic and hemorrhagic) admitted to the Stroke Unit of our University Hospital within 24 h of the onset of symptoms were included. Stroke severity was assessed according to the National Institutes of Health Stroke Scale (NIHSS) at admission and at discharge. Neurological worsening was defined as an increase of 4 or more points in the NIHSS score or death during the patient's stay at the Stroke Unit. Blood samples were drawn upon admission to measure plasma levels of BNP (Biosite Inc., San Diego, Calif., USA). Statistical analysis was performed using SPSS 15.0 and R software.

RESULTS

Altogether, 896 patients were included in the study. BNP plasma levels were higher among patients who deteriorated the most over time (n = 112; 90.5 vs. 61.2 ng/l; p = 0.006) or died (n = 83; 118.2 vs. 60.9 ng/l; p < 0.001). Multivariate logistic regression analysis indicated that plasma BNP level was an independent predictor of neurological worsening [BNP >56.7 ng/l; odds ratio (OR) = 1.64; p = 0.04] and death after stroke (BNP >65.3 ng/l; OR = 1.97; p = 0.034). Adding BNP level to other well-known clinical predictors of bad outcome did not significantly increase the predictive value.

CONCLUSIONS

Plasma levels of BNP measured during the acute phase of stroke are associated both with early neurological worsening and mortality. However, this biological information does not supply prognostic information which would add to clinical variables, which limits its use as a biomarker. Further investigation and systematic reviews are needed to clarify the role of natriuretic peptides in stroke outcome.

17 alpha-substituted analogs of estradiol for the development of fluorescent estrogen receptor ligands

For the successful development of a high-affinity fluorophore-estradiol conjugate, the fluorophore must be attached to the estradiol molecule at a position that interferes least with its binding to the receptor. We have concentrated on 17 alpha substituents as models for fluorophore attachment, based on literature precedent and on our earlier work with small 17 alpha side chains. In this report, we describe syntheses and estrogen receptor binding affinities of 19 analogs of estradiol substituted in the 17 alpha position with larger side chains (of six to 11 carbons), some of which may be synthetically modified to link a fluorophore. These analogs were synthesized either by nucleophilic cleavage of estrone-17 beta-oxirane 3-benzyl ether and subsequent debenzylation (4 to 18), by cross-coupling of alkynes (21 to 24), by alkylation of 17 alpha-ethynylestradiol 3,17-bis(tetrahydropyranyl ether) and subsequent acidic hydrolysis (25 to 28), or by reacting estrone either with appropriate aryl/alkynyllithium reagents (29, 30, and 32) or with benzylmagnesium bromide (31). Relative binding affinities of these newly synthesized analogs were determined for estrogen receptor (rat uterus) using a standard competition assay. The results suggest that analogs with reduced mobility and/or more polarizable electron density in the side chain generally bind more strongly to the receptor. The relative affinities of several selected compounds were also determined in the presence of 4% dimethylformamide; some compounds bearing larger, nonpolar 17 alpha substituents showed dramatically improved affinities, while affinities for compounds with shorter nonpolar side chains remained largely unchanged. These binding affinity results should be useful in designing new high-affinity fluorescent ligands for the estrogen receptor.

Novel esters and amides of nonsteroidal antiinflammatory carboxylic acids as antioxidants and antiproliferative agents

A series of phenolic antioxidant ester and amide derivatives of the nonsteroidal antiinflammatory drug naproxen was designed to have both antiinflammatory and cytoprotective activity. Compounds were evaluated in vitro both for antioxidant activity, as assessed indirectly by thiobarbituric acid reactive substance (TBARS) formation in a membrane lipid peroxidation assay, and for antiproliferative activity, as indexed by the inhibition of DNA synthesis in cultured human vascular endothelial cells. Compounds of this series exhibited potent antioxidant activity, with IC50 values (1.6-11.63 microM) 2-6-fold lower than that of Trolox (6-hydroxy-2,5, 7,8-tetramethylchroman-2-carboxylic acid) and 400-1300-fold lower than that of vitamin E. Structural modifications of the ester or amide substructure (5a and 6a) did not affect antioxidant activity, but methylation of the 6-hydroxy substituent resulted in compound 6f which was devoid of antioxidant activity. Although indistinguishable in antioxidant activity, the amide derivatives tended to be more potent as antiproliferative agents than the corresponding esters. The IC50's for the amide derivatives (3, 5a-e, 8) ranged from 2 to 7 microM, while the IC50's for the structurally related esters (1, 2a-c, 6a-e) ranged from 9 to 22 microM. Moreover, studies with compound 6a indicate that the observed inhibition of DNA synthesis is reversible, suggesting that the antiproliferative activity is due to a cytostatic rather than cytotoxic activity of the compounds. Thus, the antioxidant-naproxen derivatives represent a novel series of agents that both protect against free-radical damage and possess cytostatic activity in vascular endothelial cells. Studies are in progress to assess the utility of these compounds as potential components of an ocular irrigating solution.