Intratumoral pan-ErbB targeted CAR-T for head and neck squamous cell carcinoma: interim analysis of the T4 immunotherapy study

BACKGROUND

Locally advanced/recurrent head and neck squamous cell carcinoma (HNSCC) is associated with significant morbidity and mortality. To target upregulated ErbB dimer expression in this cancer, we developed an autologous CD28-based chimeric antigen receptor T-cell (CAR-T) approach named T4 immunotherapy. Patient-derived T-cells are engineered by retroviral transduction to coexpress a panErbB-specific CAR called T1E28ζ and an IL-4-responsive chimeric cytokine receptor, 4αβ, which allows IL-4-mediated enrichment of transduced cells during manufacture. These cells elicit preclinical antitumor activity against HNSCC and other carcinomas. In this trial, we used intratumoral delivery to mitigate significant clinical risk of on-target off-tumor toxicity owing to low-level ErbB expression in healthy tissues.

METHODS

We undertook a phase 1 dose-escalation 3+3 trial of intratumoral T4 immunotherapy in HNSCC (NCT01818323). CAR T-cell batches were manufactured from 40 to 130 mL of whole blood using a 2-week semiclosed process. A single CAR T-cell treatment, formulated as a fresh product in 1-4 mL of medium, was injected into one or more target lesions. Dose of CAR T-cells was escalated in 5 cohorts from 1×107-1×109 T4+ T-cells, administered without prior lymphodepletion.

RESULTS

Despite baseline lymphopenia in most enrolled subjects, the target cell dose was successfully manufactured in all cases, yielding up to 7.5 billion T-cells (67.5±11.8% transduced), without any batch failures. Treatment-related adverse events were all grade 2 or less, with no dose-limiting toxicities (Common Terminology Criteria for Adverse Events V.4.0). Frequent treatment-related adverse events were tumor swelling, pain, pyrexias, chills, and fatigue. There was no evidence of leakage of T4+ T-cells into the circulation following intratumoral delivery, and injection of radiolabeled cells demonstrated intratumoral persistence. Despite rapid progression at trial entry, stabilization of disease (Response Evaluation Criteria in Solid Tumors V.1.1) was observed in 9 of 15 subjects (60%) at 6 weeks post-CAR T-cell administration. Subsequent treatment with pembrolizumab and T-VEC oncolytic virus achieved a rapid complete clinical response in one subject, which was durable for over 3 years. Median overall survival was greater than for historical controls. Disease stabilization was associated with the administration of an immunophenotypically fitter, less exhausted, T4 CAR T-cell product.

CONCLUSIONS

These data demonstrate the safe intratumoral administration of T4 immunotherapy in advanced HNSCC.

P164 VERY LONG TERM FOLLOW UP OF PRIMARY TRANSCATHETER PATENT FORAMEN OVALE CLOSURE FOR MIGRAINE CURE

Background and Purpose

Results of previous trials about PFO closure as a treatment for migraine are still doubtful and inconclusive. We sought to evaluate the long–term (>10 years) effectiveness of migraine treatment by means of patent foramen ovale (PFO) closure.

Method

From 2006 to 2010, 86 patients (68 female, mean age 40.0 ±3.7 years) with disabling, medication–refractory migraine and PFO were enrolled in a prospective study over a 48–month period. Criteria for transcatheter closure were all the following: presence of a permanent right–to–left shunt (RLS) having a shower/curtain pattern, presence of interatrial septal aneurysm and Eustachian valve, 3 to 4 class Migraine Disability Assessment Score (MIDAS), coagulation abnormalities, and medication–refractory migraine with or without aura.

Results

Forty patients (46.5%) (34 females, mean age 35.0±6.7 years, mean MIDAS 35.8 ± 4.7) underwent transcatheter closure. After a mean follow–up of 118.2 ±19.1 months (range 96 to 144), 37 patients continued the follow–up and experienced symptomatic improvement: aura was abolished in the totality of patients along with a durable improvement of migraine throughout the extended follow up also in patients without aura. The mean MIDAS significantly decreased in the closure group (p < 0.0001). Patients with complete migraine resolution presented a shorter history of migraine, a more severe thrombophilic profile, more severe RLS and larger left atrial diameter and volume.

Conclusions

Primary transcatheter PFO closure in selected high–risk patients having disabling refractory migraine resulted in abolition of aura and in a sustained reduction in migraine in the very long–term period.

TGF-β1 potentiates Vγ9Vδ2 T cell adoptive immunotherapy of cancer

Despite its role in cancer surveillance, adoptive immunotherapy using γδ T cells has achieved limited efficacy. To enhance trafficking to bone marrow, circulating Vγ9Vδ2 T cells are expanded in serum-free medium containing TGF-β1 and IL-2 (γδ[T2] cells) or medium containing IL-2 alone (γδ[2] cells, as the control). Unexpectedly, the yield and viability of γδ[T2] cells are also increased by TGF-β1, when compared to γδ[2] controls. γδ[T2] cells are less differentiated and yet display increased cytolytic activity, cytokine release, and antitumor activity in several leukemic and solid tumor models. Efficacy is further enhanced by cancer cell sensitization using aminobisphosphonates or Ara-C. A number of contributory effects of TGF-β are described, including prostaglandin E2 receptor downmodulation, TGF-β insensitivity, and upregulated integrin activity. Biological relevance is supported by the identification of a favorable γδ[T2] signature in acute myeloid leukemia (AML). Given their enhanced therapeutic activity and compatibility with allogeneic use, γδ[T2] cells warrant evaluation in cancer immunotherapy.

Development and Validation of a Good Manufacturing Process for IL-4-Driven Expansion of Chimeric Cytokine Receptor-Expressing CAR T-Cells

Adoptive cancer immunotherapy using chimeric antigen receptor (CAR) engineered T-cells holds great promise, although several obstacles hinder the efficient generation of cell products under good manufacturing practice (GMP). Patients are often immune compromised, rendering it challenging to produce sufficient numbers of gene-modified cells. Manufacturing protocols are labour intensive and frequently involve one or more open processing steps, leading to increased risk of contamination. We set out to develop a simplified process to generate autologous gamma retrovirus-transduced T-cells for clinical evaluation in patients with head and neck cancer. T-cells were engineered to co-express a panErbB-specific CAR (T1E28z) and a chimeric cytokine receptor (4αβ) that permits their selective expansion in response to interleukin (IL)-4. Using peripheral blood as starting material, sterile culture procedures were conducted in gas-permeable bags under static conditions. Pre-aliquoted medium and cytokines, bespoke connector devices and sterile welding/sealing were used to maximise the use of closed manufacturing steps. Reproducible IL-4-dependent expansion and enrichment of CAR-engineered T-cells under GMP was achieved, both from patients and healthy donors. We also describe the development and approach taken to validate a panel of monitoring and critical release assays, which provide objective data on cell product quality.

An overview of CAR T-cell clinical trial activity to 2021

Immunotherapy of cancer using chimeric antigen receptor-engineered T-cells has transformed the management of selected haematological malignancies, triggering intense clinical trial activity in this arena. This article summarises trial activity that has been published to date across the spectrum of haematological and solid tumour types.

High Purity Factor IX and Prothrombin Complex Concentrate (PCC): Pharmacokinetics and Evidence that Factor IXa Is the Thrombogenic Trigger in PCC

Recent studies using assays for surrogate markers of thrombogenic-ity in man have demonstrated that activation of the coagulation system occurs following infusion of clinical doses of prothrombin complex concentrates (PCC) but not after the same doses of high-purity factor IX concentrates (HP-FIX) in patients with haemophilia B. Here we have investigated the mechanism of such thrombogenesis by applying assays that detect early-through to late-events in coagulation system activation in a pharmacokinetic cross-over study of 50 IU/kg PCC and a new HP-FIX product in haemophilia B patients. Satisfactory recoveries and half-lives were observed for both concentrates.

HP-FIX caused no increases in thrombin-antithrombin III complex (TAT), prothrombin activation peptide fragment F1+2 (F1+2), factor X activation peptide (FXAP) or factor Vila (FVIIa). In contrast the same dose of factor IX in the form of PCC was followed by significant increases over pre-infusion levels of TAT, F1+2 and FXAP, but not FVIIa. Elevations of FIXAP occurred after both HP-FIX and PCC but did not reach normal levels and were attributed to normalisation of the FIX concentration in those patients whose levels of FIXAP were initially low. We conclude that the thrombogenic trigger associated with PCC infusion occurs at the level of factor X activation. In the absence of any increase in FVIIa, we would attribute this to the likely presence of FIXa in the PCC.

Gastric Acid Secretion, Calcitonin and Secondary Hyperparathyroidism in Uremic Patients Undergoing Regular Dialysis Therapy (RDT)

Fortyseven uremic patients on RDT underwent a gastric secretion study and a contemporary evaluation of serum levels of Calcium (Ca), Phosphate (iP), Magnesium (Mg), Alkaline Phosphatase (AP), immunoreactive gastrin (Gas), parathyroid hormone (PTH), calcitonin (CT). Secretory test (pentagastrin 6 μg/kg) was performed in the morning, after 12 hours of fasting, in the interdialytic interval. Female patients, male patients on RDT from less 1 year and hyposecretor patients were excluded from the study. On the basis of these criteria 25 normal or hyper-secretor males between 20 and 55 years old were selected. A significant positive correlation was found between PTH and CT, while a negative significant correlation was found between CT and BAO and CT and PAO. Similarly, a significant negative correlation was found between PTH and BAO and PTH and PAO. Multiple regression study showed that the negative influence of CT on BAO and PAO is more relevant than the positive influence of PTH. These data suggest that PTH and CT are involved in gastric acid secretion in uremia. Since the inhibitory effect of CT is prevailing on the stimulating effect of PTH, patients with higher levels of PTH and CT have a lower gastric acid secretion. CT might therefore be considered as a protective factor against hypersecretion in uremia.

Tissue Factor Is Rapidly Elevated in Plasma Collected from the Pericardial Cavity during Cardiopulmonary Bypass

There is growing evidence that the tissue factor/factor VIIa pathway of coagulation is enhanced during cardiopulmonary bypass. Hitherto, available evidence has suggested that upregulated monocyte bound tissue factor is made available, either in the blood collected from the site of surgery or on circulating cells. However, cellular upregulation is slow, while generation of factor VIIa in blood collected from the pericardial cavity is rapid. We have therefore investigated the possibility of an alternative source of tissue factor, plasma (as opposed to cellular) tissue factor in blood samples taken from the central vein catheter (systemic circulation) and collected from the pericardial cavity during cardiopulmonary bypass. Six patients undergoing first time cardiopulmonary bypass grafting were studied. Tissue factor antigen was found to be rapidly elevated (by 15 min) in the pericardial plasma, ∼5-fold above systemic levels (p <0.004). Similar elevations were found in markers of coagulation activation, factor VIIa antigen (p = 0.066), prothrombin fragment F1+2 (p <0.003) and thrombin-antithrombin complex (p <0.03). To explore whether plasma tissue factor was (or had been) functionally active, factor VIIa was measured also with the soluble tissue factor functional assay after removal of heparin. Functional factor VIIa activity fell significantly in the systemic circulation, probably due to the heparin-induced increase (∼15-fold) in tissue factor pathway inhibitor (TFPI), but was elevated in pericardial blood compared with that taken from the central line catheter (p <0.006). These results demonstrate that both components of the activation complex for the extrinsic pathway of coagulation are rapidly generated in pericardial blood during bypass.

Abstract CT118: T4 immunotherapy of head and neck squamous cell carcinoma using pan-ErbB targeted CAR T-cells

Striking progress has been achieved in CD19+ hematologic malignancies using chimeric antigen receptor (CAR) T-cells following lymphodepletion. Nonetheless, toxicity remains significant, due to cytokine release syndrome (CRS) and neurologic dysfunction. The frequent emergence of resistance due to antigen loss provides a strong rationale for engagement of multiple targets. Solid tumors impose additional challenges. Foremost, a paucity of targets that are tumor-specific, or restricted to dispensable tissues. Moreover, active CAR T-cells need to home to, penetrate and persist within profoundly immunosuppressive tumors. Cognizant of these obstacles, we designed T4 immunotherapy. T4+ T-cells are retroviral transduced to co-express (i) T1E28ζ, a CAR coupling a promiscuous ErbB ligand derived from EGF and TGFα to a fused CD28+CD3ζ endodomain; and (ii) 4αβ, a chimeric cytokine receptor containing the IL-4Rα ectodomain coupled to the IL-2Rβ endodomain. T1E28ζ engages 8/9 possible ErbB dimers, providing broad anti-tumor activity while minimizing risk of antigen escape. 4αβ enables IL-4-driven selective enrichment and expansion of CAR T-cells during manufacture. Pre-clinical data demonstrate potent anti-tumor activity in head and neck squamous cell carcinoma (HNSCC), mesothelioma, ovarian and breast cancer. However, risk of on-target off-tumor toxicity is significant, due to low-level ErbB expression in normal tissues. Indeed, CRS can be modeled when human T4+ T-cells are administered to the peritoneal cavity of SCID Beige mice. To de-risk T4 immunotherapy in man, a dose-escalation intra-tumoral Phase I trial was commenced, without lymphodepletion. HNSCC was selected due to the unmet need presented by locally advanced or recurrent disease. Ninety percent of patients were lymphopenic yet T4 immunotherapy was successfully generated from a 130mL blood draw, in a closed manufacturing process. Batches contained up to 7.5 x 109 cells, of which 63.8+ 12.1% were T4+, comprising a variable mixture of central and effector memory CD4+ and CD8+ T-cells. Cohorts of 1, 3 and 10 x 107 T4+ T-cells were treated. Patient 5 died of advanced HNSCC, prior to treatment. Intra-tumoral 1-2mL injections of T4 immunotherapy were administered as a single dose. Treatment-related AEs were &lt; grade 2, with no dose-limiting toxicities (CTCAE v4.0). Common AEs were tumor swelling/ pain and fatigue. All patients experienced a self-limited rise in CRP. Grade 1 chills occurred in cohort 3 within 24h. Circulating T4+ T-cells were not seen. Disease control rate was 44% with all three patients in cohort 3 achieving stable disease (RECIST 1.1 at 6 weeks). These data demonstrate the safe intra-tumoral administration of T4-immunotherapy in patients with advanced HNSCC, with disease control observed at the highest dose tested. Further dose escalation and combination with immune-modulating agents is warranted.

Citation Format: Sophie Papa, Antonella Adami, Michael Metoudi, Daniela Achkova, May van Schalkwyk, Ana Parente Pereira, Leticia Bosshard-Carter, Lynsey Whilding, Sjoukje van der Stegen, David M. Davies, Teresa Guerrero-Urbano, Jean Pierre Jeannon, James Spicer, John Maher. T4 immunotherapy of head and neck squamous cell carcinoma using pan-ErbB targeted CAR T-cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT118. doi:10.1158/1538-7445.AM2017-CT118

Oxygen deficit during supramaximal cycling exercise in humans: a new estimation method

AIM

We propose a method to estimate O2 deficit (DefO2) during supramaximal exercise based on the analysis of gas exchanges.

METHODS

We determined in 14 male subjects breath-by-breath ∙VO2 at the onset of step exercise of moderate and supramaximal intensities. ∙VO2 response during moderate-intensity exercise was fitted as a bi-exponential model. Third, we modelled a theoretical ∙VO2 kinetics during supramaximal exercise assuming that it conformed to the ∙VO2 kinetics measured during moderate-intensity exercise and tended towards a ∙VO2 equal to that hypothetically elicited by the workload. The difference between the O2 volume that would have been consumed in the hypothetical condition and that actually taken up during exercise yielded the lactacid fraction of DefO2. Finally, the difference between the estimated total energy requirement and the theoretical O2 volume consumed by the subject yielded in the alactacid fraction of total DefO2.

RESULTS

Total DefO2 was 77.6 mL O2 kg-1; its anaerobic alactic and lactic fractions amounted to 38.5 and 39.1 mL O2 kg-1, respectively. The latter did not differ significantly from the value calculated independently from the peak increase in lactate concentration during supramaximal exercise times the energy equivalent of lactate.

CONCLUSIONS

These results suggest that supramaximal DefO2 and its components may be estimated from an analysis of gas exchange kinetics. In addition, they are consistent with the view that the mechanism regulating muscular O2 uptake is regulated by the muscular concentration of putative metabolites.

Detection and Classification of Movements in Bed using Load Cells

The quality of our life is tied to the quality of our sleep. People with sleep deficits may experience impaired performance, irritability, lack of concentration, and daytime drowsiness. Increased mobility in bed can be a sign of disrupted sleep. Therefore, body movements in bed represent an important behavioral aspect of sleep. In this paper, we propose a method for detection and classification of movement that uses load cells placed at each corner of a bed. The detection of movements is based on short-term analysis of the mean-square differences of the load cell signals. Movement classification is based on features extracted from a wavelet-based tiresolution analysis (MRA) to classify the type of movement into two classes: small and large. A linear classifier is trained on each level of the MRA, and the decisions of the 4 classifiers are combined using a Bayesian combination rule. The method is evaluated on load cell data collected from 6 subjects. Each subject performed 5 trials composed of 20 pre-defined movements including small shifts of position to large movements of torso and limbs. The performance measure for the detection problem is the equal error rate (EER). We show that the detection method achieves a 2.9% EER and that the classification method has a classification error of 4%.

Anti-Gal titers in healthy adults and inflammatory bowel disease patients

INTRODUCTION

ALPHA-GAL is a glycoconjugate present on cell membranes of mammals and bacteria but not humans who display anti-Gal antibodies (AB) in high titers provoked by the commensal gut flora. In the present study, we sought to determine the longitudinal course of alpha-Gal specific AB titers of all isotypes over 8 weeks among healthy adult subjects. Furthermore, we hypothesized that inflammatory bowel disease (IBD) patients display increased anti-Gal titers.

MATERIALS AND METHODS

We drew serum from healthy probands (n=20) weekly for 8 weeks and obtained plasma samples of from patients suffering from Crohn's disease (n=20) and ulcerative colitis (n=20). We measured anti-Gal ABs of all isotypes and total immunoglobulin (Ig) content using an enzyme-linked immunosorbent assay technique. For statistical evaluation of the longitudinal titers, we calculated confidence intervals for the slopes of a random intercept model, comparing variances between and within the probands. For group comparisons, we performed paired student t-tests and Pearson correlations.

RESULTS

Alpha-Gal specific IgG, IgM, IgD, and IgA titers remained unvaried within a narrow range upon longitudinal observation. Most probands did not display alpha-Gal specific IgE ABs. Crohn's disease patients showed highly increased alpha-Gal-specific IgA titers compared with control subjects (P<.01).

CONCLUSION

Apart from IgE, alpha-Gal-specific ABs of all isotypes remained constant over longer time periods in healthy subjects. Thus, significant titer changes actually represent increased antigen exposure and a specific anti-alpha-Gal response. Crohn's disease patients display increased anti-Gal IgA titers compared with healthy controls, which reflects a chronically impaired mucosal gut barrier in this patient cohort.

Cerebral distribution of white matter lesions in migraine with aura patients

OBJECTIVE

The objective of the study was to compare the cerebral distribution of white matter lesions (WMLs) between migraine patients with different aura symptoms.

METHODS

Migraine with aura (MA) patients were consecutively enrolled as part of the Shunt-Associated Migraine (SAM) study. According to clinical symptoms, aura was classified as motor, aphasic, sensory, visual or vertebrobasilar. Standard and FLAIR (fluid attenuated inversion recovery) T(2)-weighted MRI sequences were inspected for WMLs by three independent raters blinded to clinical data. WMLs were assessed in the periventricular areas (PV-WMLs) with the Fazekas scale and in the deep white matter (D-WMLs) with the Schelten's scale. Interobserver agreement was good to excellent (k = 0.64 to 0.96, p < .0001).

RESULTS

One hundred and eighty-five patients (77% women) were included. Aura symptoms were classified as visual in 172 (99%) patients, sensory in 76 (42%), aphasic in 54 (30%), motor in 39 (21%) and vertebrobasilar in 17 (9%) patients. One hundred and four patients (57%) exhibited more than one type of aura. D-WMLs were mainly detected in the frontal lobes (86%). There was no association between type of aura and the presence of WMLs in any cerebral location.

CONCLUSION

Aura symptoms do not influence the cerebral distribution of WMLs associated with migraine disease.

Mechanical characterization of thin TiO2 films by means of microelectromechanical systems-based cantilevers

The measurement of mechanical parameters by means of microcantilever structures offers a reliable and accurate alternative to traditional methods, especially when dealing with thin films, which are extensively used in microfabrication technology and nanotechnology. In this work, microelectromechanical systems (MEMS)-based piezoresistive cantilevers were realized and used for the determination of Young's modulus and residual stress of thin titanium dioxide (TiO(2)) deposited by sputtering from a TiO(2) target using a rf plasma discharge. Films were deposited at different thicknesses, ranging from a few to a hundred nanometers. Dedicated silicon microcantilevers were designed through an optimization of geometrical parameters with the development of analytical as well as numerical models. Young's modulus and residual stress of sputtered TiO(2) films were assessed by using both mechanical characterization based on scanning profilometers and piezoresistive sensing elements integrated in the silicon cantilevers. Results of MEMS-based characterization were combined with the tribological and morphological properties measured by microscratch test and x-ray diffraction analysis.

Radiation exposure prior to ischemia decreases lesion volume, brain edema and cell death

PURPOSE

To investigate the neuronal response to ischemic injury following exposure to whole brain proton irradiation.

METHODS

Brain only proton irradiation (8 Gy, 250 MeV) was performed ten days prior to middle cerebral artery occlusion (MCAO) in 1 year old male Sprague Dawley rats. MCAO was induced in two animal groups: proton irradiated (MCAO + Rad) and MCAO only. Magnetic resonance imaging (MRI) and quantitative analysis were performed prior to and 2 days after irradiation, and then 2, 14 and 28 days after MCAO. After the last imaging time point animals were sacrificed and TUNEL staining was performed on 4% paraformaldehyde - fixed brain sections.

RESULTS

Neuroimaging demonstrated a reduction in ischemic lesion volume in the MCAO + Rad group compared with MCAO alone. Neurological deficits did not differ between ischemia groups. Interestingly, there was a 34% decrease in the number of TUNEL-positive cells in MCAO + Rad brains compared to MCAO alone.

CONCLUSION

Our results suggest that radiation treatment reduces brain edema, ischemic lesion volume and peri-ischemic apoptosis. The underlying mechanisms are currently unknown and additional studies will elucidate the significance of these results.

Expanding CEP290 mutational spectrum in ciliopathies

Ciliopathies are an expanding group of rare conditions characterized by multiorgan involvement, that are caused by mutations in genes encoding for proteins of the primary cilium or its apparatus. Among these genes, CEP290 bears an intriguing allelic spectrum, being commonly mutated in Joubert syndrome and related disorders (JSRD), Meckel syndrome (MKS), Senior-Loken syndrome and isolated Leber congenital amaurosis (LCA). Although these conditions are recessively inherited, in a subset of patients only one CEP290 mutation could be detected. To assess whether genomic rearrangements involving the CEP290 gene could represent a possible mutational mechanism in these cases, exon dosage analysis on genomic DNA was performed in two groups of CEP290 heterozygous patients, including five JSRD/MKS cases and four LCA, respectively. In one JSRD patient, we identified a large heterozygous deletion encompassing CEP290 C-terminus that resulted in marked reduction of mRNA expression. No copy number alterations were identified in the remaining probands. The present work expands the CEP290 genotypic spectrum to include multiexon deletions. Although this mechanism does not appear to be frequent, screening for genomic rearrangements should be considered in patients in whom a single CEP290 mutated allele was identified.

Is migraine associated with right-to-left shunt a separate disease? Results of the SAM study

Migraine with aura (MA) is associated with the persistence of patent foramen ovale (PFO) in about 50% of cases, and migraineurs tend to have larger shunts than controls, suggesting that right-to-left shunt (RILES) determined by PFO could play a role in triggering migraine attacks. Moreover, some preliminary reports have suggested that PFO closure may give relief to both migraine and aura attacks. The aim of this study was to clarify if shunt-associated migraine (SAM) has clinical features that allow a distinction from shunt-unrelated migraine (SUM), in a prospective, multicentre, observational study (SAM study). We enrolled consecutive MA patients, who underwent a structured, standardized questionnaire for family and personal history and for detailed migraine features. All were systematically screened for RILES with transcranial Doppler, and for coagulation disorders. Overall, 460 patients were included; the SUM and SAM classes comprised 58% and 42% of patients, respectively. SAM patients were significantly younger (34.1 +/- 10 vs. 37.1 +/- 11 years), had a more frequent family history of migraine (76% vs. 66%) and a higher frequency of sensory symptoms of aura (51% vs. 41%); by contrast, there was a lesser association of SAM with other cardiac abnormalities and with coagulation disorders. The SAM study suggests that the effect of RILES on migraine features is not relevant. The higher family history of migraine in SAM suggests a possible genetic linkage between migraine and RILES.

GAMT deficiency: Features, treatment, and outcome in an inborn error of creatine synthesis

BACKGROUND

Guanidinoactetate methyltransferase (GAMT) deficiency is an autosomal recessive disorder of creatine synthesis. The authors analyzed clinical, biochemical, and molecular findings in 27 patients.

METHODS

The authors collected data from questionnaires and literature reports. A score including degree of intellectual disability, epileptic seizures, and movement disorder was developed and used to classify clinical phenotype as severe, moderate, or mild. Score and biochemical data were assessed before and during treatment with oral creatine substitution alone or with additional dietary arginine restriction and ornithine supplementation.

RESULTS

Intellectual disability, epileptic seizures, guanidinoacetate accumulation in body fluids, and deficiency of brain creatine were common in all 27 patients. Twelve patients had severe, 12 patients had moderate, and three patients had mild clinical phenotype. Twenty-one of 27 (78%) patients had severe intellectual disability (estimated IQ 20 to 34). There was no obvious correlation between severity of the clinical phenotype, guanidinoacetate accumulation in body fluids, and GAMT mutations. Treatment resulted in almost normalized cerebral creatine levels, reduced guanidinoacetate accumulation, and in improvement of epilepsy and movement disorder, whereas the degree of intellectual disability remained unchanged.

CONCLUSION

Guanidinoactetate methyltransferase deficiency should be considered in patients with unexplained intellectual disability, and urinary guanidinoacetate should be determined as an initial diagnostic approach.

Naturally occurring mutations in the thrombomodulin gene leading to impaired expression and function

Sporadic mutations in the thrombomodulin (TM) gene occur in patients with both arterial and venous thrombosis, but the effects of these mutations on expression and function are largely unexplored. Full-length wild-type TM complementary DNA (cDNA) was incorporated into vector pcDNA6 for transfection into COS-7 cells for transient expression. Mutagenesis was performed to create 7 TM mutants with natural mutations either previously identified (Ala25Thr, Gly61Ala, Asp468Tyr, Pro477Ser, Pro483Leu) or reported here (an 11-base pair [bp] deletion, del791-801, leading to STOP306, and a missense mutation, Arg385Ser). Four mutations were found to detrimentally affect the level of expression of the TM protein. Of the missense mutations, 3 had reduced expression compared to wild-type TM (100%), Arg385Ser (50.2% +/- 5%, P <.001), Pro477Ser (76.8% +/- 1%, P <.001), Pro483Leu (82.1% +/- 8%, P <.007). No TM protein expression could be detected on the cell surface for mutation del791-801. The cofactor activity of TM in protein C activation was also evaluated. The Michaelis constant (K(m)) for wild-type thrombin-TM complex was 634 +/- 6 nmol/L. Two mutants, with Arg385Ser and Pro477Ser, had increased (P <.0001) K(m), 2967 +/- 283 nM, and 2342 +/- 219 nM, respectively, demonstrating impaired function of the thrombin-TM complex. This work presents biochemical evidence that certain (but not all) natural mutations in the TM gene reduce expression and impair function of the protein on the cell surface, and helps clarify the suggested contribution that these mutations might make to the risk of thromboembolic disease.

Relationship between severity of MR perfusion deficit and DWI lesion evolution

OBJECTIVE

To assess whether a quantitative analysis of the severity of the early perfusion deficit on MRI in acute ischemic stroke predicts the evolution of the perfusion/diffusion mismatch and to determine thresholds of hypoperfusion that can distinguish between critical and noncritical hypoperfusion.

METHODS

Patients with acute ischemic stroke were studied in whom perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI MRI) were performed within 7 hours of symptom onset and again after 4 to 7 days. Patients with early important decreases in points on the NIH Stroke Scale were excluded. Maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were created. These hemodynamic parameters were correlated with the degree of recruitment of the baseline PWI lesion by the DWI lesion.

RESULTS

Twelve patients had an initial PWI > DWI mismatch of >20%. A linear relationship was observed between the initial MTT and the degree of recruitment of the baseline PWI lesion by the DWI lesion at follow-up (R(2) = 0.9, p < 0.001). Higher CBV values were associated with higher degrees of recruitment (rho = 0.732, p < 0.007). The volume of MTT of >4 (R(2) = 0.86, p < 0.001) or >6 seconds (R(2) = 0.85, p < 0.001) predicted final infarct size.

CONCLUSION

Among patients who have had an acute stroke with PWI > DWI, who do not have dramatic early clinical improvement, the degree of expansion of the initial DWI lesion correlates with the severity of the initial perfusion deficit as measured by the mean transit time and the cerebral blood volume.

CD23 and CD69 expression on human neutrophils of healthy subjects and patients with peripheral arterial occlusive disease

In this work we studied, on human neutrophils from healthy donors and patients with peripheral arterial occlusive disease, the expression of CD23 and CD69 and the modulatory effects of IFN-gamma, GM-CSF and IL-4. Neutrophils were isolated from 9 patients and 9 healthy subjects and cultured for 24 h in absence or presence of IFN-gamma (1000 U/ml), GM-CSF (10 U/ml) and IL-4 (10 ng/ml). Expression of CD23 and CD69 was analyzed by FACScan cytofluorimeter. Neutrophils of both patients and healthy donors resulted negative for CD23 and CD69 expression immediately after isolation. After 24 h without stimuli, neutrophils from some patients and healthy donors expressed CD23 and CD69. IFN-gamma and GM-CSF had opposite effects on these two antigens, down-regulating CD23 and up-regulating CD69. IFN-gamma, GM-CSF and IL-4 were not able to induce CD23 expression, while CD69 expression was induced in some negative healthy donors and patients by IFN-gamma, GM-CSF and IL-4 respectively. From our data, we identified two subpopulations of neutrophils that, independently from the vascular pathology, showed a different behaviour towards temperature and some cytokines.

Pharmacokinetics of intrathecal transferrin-ricin a chain immunotoxin

We have studied the pharmacokinetics of an anti-transferrin receptor immunotoxin following intrathecal (i.t.) and intravenous (i.v.) bolus inoculation in healthy rats. After i.t. inoculation of 4.9 microg transferrin-ricin A-chain (Tfn-RTA) we have measured the immunotoxin concentration in the cerebrospinal fluid (CSF), in the brain tissue and in the peripheral blood. After i.v. administration of 4.9 microg Tfn-RTA the concentration of Tfn-RTA immunotoxin was evaluated in the peripheral blood. We found that the clearance of Tfn-RTA from the CSF is rapid (9.1 microLmin(-1)), the immunotoxin then diffuses into the brain tissue and in the peripheral blood where it reaches concentrations below the MTC50 (Minimum Toxin Concentration 50%). The rate of immunotoxin elimination from the peripheral blood following either i.v. or i.t. administration are similar (kel = 0.0021 min(-1) vs. 0.0025 min(-1)). Thus, in the healthy rat the immunotoxin does not accumulate following i.t. inoculation, reaching non toxic concentrations in the brain tissue and in the peripheral blood, whereas in the CSF as well as at the interface CSF/brain tissue the immunotoxin may reach potentially therapeutic concentrations. In conclusion we believe that the i.t. inoculation of an immunotoxin could be considered a potentially useful route of administration in the treatment of leptomeningeal carcinomatosis.

Prediction of hemorrhagic transformation following acute stroke: role of diffusion- and perfusion-weighted magnetic resonance imaging

BACKGROUND

Acute diffusion-weighted (DWI) and perfusion-weighted (PWI) magnetic resonance imaging (MRI) findings may correlate with secondary hemorrhagic transformation (HT) risk in patients with stroke. This information could be of value, particularly in individuals being considered for thrombolytic therapy.

OBJECTIVE

To determine the relationship between DWI and PWI findings and the risk of secondary HT in patients with acute stroke.

DESIGN

Retrospective case series.

SETTING

Academic medical center.

PATIENTS

Twenty-seven patients with acute stroke capable of being evaluated with DWI/PWI 8 hours or less after symptom onset.

MAIN OUTCOME MEASURES

Apparent diffusion coefficient values, perfusion delay measurements, and subsequent MRI or computed tomographic scans detected HT.

RESULTS

The mean +/- SD apparent diffusion coefficient of ischemic regions that experienced HT was significantly lower than the overall mean +/- SD apparent diffusion coefficient of all ischemic areas analyzed (0.510 +/- 0.140 x 10(-3) mm(2)/s vs 623 +/- 0.113 x 10(-3) mm(2)/s; P =.004). This difference remained significant when comparing the HT-destined ischemic areas with the non-HT-destined areas within the same ischemic lesion (P =.02). Patients receiving recombinant tissue-type plasminogen activator (rt-PA) experienced HT significantly earlier than patients not receiving rt-PA (P =.002). Moreover, a persistent perfusion deficit in the area of subsequent hemorrhage at 3 to 6 hours after the initial MRI scan was identified in significantly more patients who experienced HT than in those who did not (83% vs 30%; P =.03).

CONCLUSION

Both DWI and PWI scans detect abnormalities that are associated with HT. These findings support a role for MRI in identifying patients who are at increased risk for secondary HT following acute ischemic stroke.

Relationship between apparent diffusion coefficient and subsequent hemorrhagic transformation following acute ischemic stroke

BACKGROUND AND PURPOSE

A method for identifying patients at increased risk for developing secondary hemorrhagic transformation (HT) after acute ischemic stroke could be of significant value, particularly in patients being considered for thrombolytic therapy. We hypothesized that diffusion-weighted MRI might aid in the identification of such patients.

METHODS

We retrospectively analyzed 17 patients with ischemic stroke who received diffusion-weighted MRI within 8 hours of symptom onset and who also received follow-up neuroimaging within 1 week of initial scan. The apparent diffusion coefficient (ADC) for each pixel in the whole ischemic area was calculated, generating a histogram of values. Areas subsequently experiencing HT were then compared with areas not experiencing HT to determine the relationship between ADC and subsequent HT.

RESULTS

A significantly greater percentage of pixels possessed lower ADCs (</=550x10(-)(6) mm(2)/s) in HT lesions compared with non-HT lesions (47% versus 19%; P:<0.001). Moreover, >40% of the pixels possessed values </=550x10(-)(6) mm(2)/s in all lesions experiencing secondary HT, compared with <31% of the pixels in the non-HT-destined lesions.

CONCLUSIONS

HT-destined stroke regions possess a significantly great percentage of low ADC values than non-HT-destined regions. Early measurement of ADC values may be a useful tool for assessing secondary HT risk.

Tissue factor is rapidly elevated in plasma collected from the pericardial cavity during cardiopulmonary bypass

There is growing evidence that the tissue factor/factor VIIa pathway of coagulation is enhanced during cardiopulmonary bypass. Hitherto, available evidence has suggested that upregulated monocyte bound tissue factor is made available, either in the blood collected from the site of surgery or on circulating cells. However, cellular upregulation is slow, while generation of factor VIIa in blood collected from the pericardial cavity is rapid. We have therefore investigated the possibility of an alternative source of tissue factor, plasma (as opposed to cellular) tissue factor in blood samples taken from the central vein catheter (systemic circulation) and collected from the pericardial cavity during cardiopulmonary bypass. Six patients undergoing first time cardiopulmonary bypass grafting were studied. Tissue factor antigen was found to be rapidly elevated (by 15 min) in the pericardial plasma, approximately 5-fold above systemic levels (p <0.004). Similar elevations were found in markers of coagulation activation, factor VIIa antigen (p = 0.066), prothrombin fragment F(1+2) (p <0.003) and thrombin-antithrombin complex (p <0.03). To explore whether plasma tissue factor was (or had been) functionally active, factor VIIa was measured also with the soluble tissue factor functional assay after removal of heparin. Functional factor VIIa activity fell significantly in the systemic circulation, probably due to the heparin-induced increase (approximately 15-fold) in tissue factor pathway inhibitor (TFPI), but was elevated in pericardial blood compared with that taken from the central line catheter (p <0.006). These results demonstrate that both components of the activation complex for the extrinsic pathway of coagulation are rapidly generated in pericardial blood during bypass.

Occurrence of selected bacterial groups in the faeces of piglets fed with Bacillus coagulans as probiotic

A microbiological analysis of piglet faeces was performed on samples collected from animals fed a diet without any additive, animals fed a diet that contained Bacillus coagulans CNCMI-1061 as probiotic, and animals fed a diet that contained Zn-bacitracin. The analysis was carried out in concurrence with a zootechnical trial. Selected bacterial groups (lactic acid bacteria, lacotococci, enterococci, aerobic and anaerobic cocci, total and faecal coliforms, clostridia, bacteroides, bifidobacteria) were determined at day 1 and after 1, 4 and 10 weeks of life. Numbers of enterococci, coliforms (especially faecal coliforms) showed a decrease over time with probiotic, more evident than with the antibiotic. Daily administration of B. coagulans allowed this bacterium to become integrated into the enteric microflora where it is transient. These results seem to show a positive effect of B. coagulans addition on cocci and faecal coliforms. We suggest that this probiotic may represent an alternative to antibiotics.

Influence of an acute exercise on neutrophil and platelet adhesion, nitric oxide plasma metabolites in inactive and active subjects

In this work we studied the influence of an acute exercise either on nitrite/nitrate plasma levels or on neutrophil and platelet adhesion in inactive and active subjects. Twelve healthy subjects (6 inactives and 6 actives) exercised on a racing cycle ergometer performing stepwise increases in intensity until reaching, within 5 min, a heart rate of 150 beats x min(-1) which represents an oxygen consumption of about 75 % of the individual maximum rate of oxygen uptake. From peripheral venous blood samples (drawn from all subjects before, immediately after the end of exercise, and 1 hour later) neutrophils and platelets were isolated to test plate adhesion, and nitrite/nitrate concentrations were measured in the plasma. Immediately after the acute exercise, in active subjects we observed a significant decrease in the percentage of neutrophil adhesion (7.96+/-2.38 vs. 14.10+/-3.14), associated with an increase in nitrite/nitrate plasma levels (81.38+/-10.76 vs. 41.08+/-8.13 micromol x l(-1)), restored by a 40 min pre-incubation with NG-nitro-L-arginine methyl ester (L-NAME). In unstimulated platelets we observed a significant lower percentage of platelet adhesion in active subjects compared to inactives after exercise. With thrombin or adenosine 5'-diphosphate as agonists platelet adhesion did not result significantly different in active subjects compared to inactives. In conclusion, our data show that physical exercise can induce changes in some cell activities, even if transient, and favour the generation of nitric oxide. The lower adhesion of neutrophils and platelets induced by regular exercise could be an important goal in the prevention of vascular and inflammatory diseases.

Relationships between homocysteine, factor VIIa, and thrombin generation in acute coronary syndromes

BACKGROUND

It has been suggested by clinical, epidemiological, and experimental in vitro studies that homocysteine potentiates thrombin generation. This prothrombotic effect however has not previously been demonstrated in patients presenting with acute coronary syndromes (ACS).

METHODS AND RESULTS

Patients with ACS (n =117) presenting with confirmed acute myocardial infarction (MI) (n =57) or unstable angina pectoris (UAP) (n =60) were consecutively recruited together with patients (n =18) in whom the presenting chest pain was not of cardiac origin (NCP), included as controls. Plasma samples were collected on admission and before clinical intervention. Homocysteine was assayed by high performance liquid chromatography, and both Factor VIIa and prothrombin fragment F1+2 were analyzed by ELISA. There were significant elevations in F1+2 in MI (P<0.001) and UAP (P=0.003), and modest elevations in Factor VIIa in UAP (P<0.05) compared with NCP but no differences in homocysteine levels among those groups. On dividing patients with ACS into quartiles of homocysteine, there was a stepwise increase in F1+2 (P<0.0001) and of Factor VIIa (P<0.05). There were significant correlations in ACS between homocysteine and F1+2 (r=0.46, P<0.0001), homocysteine and Factor VIIa (r=0.24, P<0.01), and F1+2 and Factor VIIa (r=0.41, P<0.0001). There was no correlation between homocysteine and either F1+2 (r=-0.15, P=0.57) or Factor VIIa (r=0. 22, P=0.37) in the NCP patients.

CONCLUSIONS

Elevated plasma homocysteine is associated with and may cause elevated Factor VIIa and thrombin generation in patients presenting with ACS. These findings suggest an explanation for the prothrombotic effect of homocysteine in ACS.

Expression of FCepsilonII/CD23 on human neutrophils isolated from rheumatoid arthritis patients

CD23, the low affinity receptor for IgE, is a 45 kilodalton molecule belonging to the C-type lectin family, some members of which have been identified as adhesion molecules. Since it has been described upregulated in different cells in chronic inflammatory diseases and in rheumatoid arthritis in particular, where neutrophils are directly involved in tissue damage, our interest, in this work, has been focused on the expression and regulation of this antigen on neutrophil membrane. We studied 22 patients suffering from rheumatoid arthritis and 22 healthy control subjects. CD23 expression on neutrophil membrane was analyzed by immunofluorescence. Neutrophils of 9 out of 22 patients expressed CD23 molecules, neutrophils of 11 out of 22 patients expressed CD23 only after 24 h of incubation in RPMI; only 2 out of 22 patients did not express the CD23 antigen on neutrophil membrane either after isolation or after a 24 h incubation. On the contrary neutrophils isolated from healthy subjects did not express CD23 molecules upon isolation. Only in 7/22 control subjects neutrophils resulted positive after 24 h of incubation in RPMI. Moreover, we found that in our experimental conditions the presence of IFN-g or GM-CSF alone or in combination with IL-4 inhibited CD23 expression during the 24 h incubation. Our results show that there is a strong association between neutrophil ability to express CD23 and rheumatoid arthritis, and that such expression may be regulated by GM-CSF, IFN-gamma and IL-4.

Feasibility of prenatal diagnosis of lysinuric protein intolerance by linkage analysis: a case report

Lysinuric protein intolerance (LPI) is a rare autosomal recessive defect of cationic amino acid transport (CAA), relatively common in Finland and Italy. After weaning, LPI patients present poor feeding, vomiting and failure to thrive. A severe pulmonary complication and episodes of metabolic imbalance may lead to death. Prenatal diagnosis has not been available due to lack of either biochemical or molecular markers to be used in the fetal period. The LPI locus has recently been assigned to chromosome 14q12, very close to the T-cell receptor alpha-chain (TCRA) locus. We carried out a prenatal diagnosis for LPI by linkage analysis in one LPI Italian family after CVS. For the haplotype analysis 11 DNA markers from the LPI critical region were used (D14S742, D14S50, D14S283, five TCRA intragenic polymorphic sites, D14S990, MYH7 and D14S80). It was concluded that the haplotype analysis indicated that the fetus was healthy as he had inherited the two wild alleles of the LPI locus. After birth, the clearances of CAA were measured and found to be in the normal range, thus confirming the result of the prenatal diagnosis. The prenatal diagnosis of LPI can now be offered to families affected by LPI.

[Anomic aphasia in a 5-year-old child following herpetic encephalitis]

Aphasia is a rare neurologic disorder in childhood. Nevertheless some authors believe that some subtle aphasic syndromes as anomic aphasia are not always identified and the real prevalence of aphasia in childhood is higher. We observed a case of aphasia during the acute period of Herpes Simplex Encephalitis in a 5 years old, right handed, boy with a good level of fluent speech. Six weeks after his initial assessment language was spontaneous, fluent, with normal prosodhy and articulation, but reduced, without content words, with frequent circunlocutory speech, semantic paraphasias, anomic latencies, real anomias, "pass partout" words. This picture was suggestive for anomic aphasia in a normally fluent context. Anomic aphasia can be produced by the disconnection between cortical and subcortical systems. Documented cases of anomic aphasia in childhood are rare. Our case present great similarities with adult cases in terms of localisation and denomination difficulties.

Biotransformation and cytotoxic properties of NO-donors on MCF7 and U251 cell lines

Previous studies have shown a role for nitric oxide (NO) as a cytotoxic effector. In the present work, two chemically different NO-donors such as glyceryl trinitrate (GTN) and S-nitroso-N-acetylpenicillamine (SNAP) were evaluated for both NO release and cytostatic/cytotoxic properties. Nitrite accumulation in the supernatant of MCF-7 and U251 cell lines indicated a greater and quickly release of NO derived from SNAP. A time-course of hemoglobin absorption spectral changes showed a greater release of NO derived from GTN in presence of cells compared to the values observed in the media, confirming that the release of NO by GTN can be enzymatic and non-enzymatic. On the contrary, SNAP generated NO without contribution of cellular components and saturated oxyhemoglobin quickly, within 2 hours. Both NO-donors inhibited thymidine incorporation in a similar manner and dose-dependently in U251 cells, but not in MCF-7 cells, where SNAP at the highest tested dose of 1000 microM induced only a 33% cytostatic effect. About trypan blue exclusion test, after 24 h GTN and SNAP, releasing similar amounts of NO, showed comparable cytotoxic effects on U251 cells (50% dead cells), but not on MCF-7 cells, where GTN resulted more cytotoxic. From our data, the "in vitro" antitumoral activity of NO-donors seems to be related to the type of tumor cell lines, to the amount and duration of NO release.

Performance of broiler chickens supplemented with Bacillus coagulans as probiotic

1. A newly isolated Bacillus coagulans strain as probiotic was assayed as the only dietary additive for chickens. 2. Chickens receiving no additive at all or only virginiamycin were used for comparison. 3. Two trials each carried out on 75 chickens showed that, in terms of efficacy in growth and food conversion ratio, the B. coagulans biomass as a probiotic had a growth-promoting, prophylactic effect comparable to that of virginiamycin.

Neutrophil behavior following exposure to in vivo or in vitro zinc in normal and acutely-inflamed rats: studies on lysozyme secretion, superoxide anion release and platelet adhesion

The mechanism was studied of the anti-inflammatory effect of oral zinc (114 mg/kg/day of elemental metal, given for 14 days) on the development of the carrageenan-induced paw oedema of the rat, and the impact of in vivo treatment on the activity of neutrophils isolated from the blood of inflamed and non-inflamed animals. The effects of the in vitro incubation with the metal on either non-inflamed or inflamed neutrophils coming from zinc-untreated rats were also examined. It was found that the administration of oral zinc inhibited markedly the process of ex vivo adhesion of the cells obtained from the inflamed rats (an observation confirmed by the in vitro experiments). In vitro release of lysozyme and superoxide anion productions were measured: in the absence of zinc, the 30' of pre-incubation carried out before stimulating with PMA did not influence the cell's reactivity of the non-inflamed neutrophils. It was, on the contrary, capable of significantly reducing that of the inflamed ones. As a consequence, it is quite difficult to properly interpret the data obtained studying the activity of the cells exposed to the metal in vitro.

Role of endogenous and exogenous nitric oxide on intestinal mucosa and microflora in the rat

In the present study the effects of exogenous and endogenous nitric oxide (NO) on intestinal bacteria and on the intestinal tissue integrity have been investigated in healthy rats and in rats receiving bacterial endotoxin (LPS). A segment of jejunum was taken in order to evaluate tissue damage and hematoxylin-eosin staining; microbiological studies were carried out collecting stool samples. Administration of LPS (5 mg kg-1 i.v.) induced a moderate jejunal damage, which was completely prevented by NG-nitro-L-arginine methyl ester (L-NAME), 5 mg kg-1 s.c.), thus suggesting a damage of endogenous NO on the intestinal mucosa; sodium nitroprusside (SNP, 10 mg kg-1 os) reduced significantly jejunal damage induced by LPS. Endogenous NO produced by the administration of LPS resulted to be cytotoxic for all examined aerobic and anaerobic bacteria, while exogenous NO, released from SNP, showed an inhibitory effect only on Entero. faecalis and E. coli growth. From our data, it seems reasonable to conclude that high local levels of NO are required in order to observe jejunal damage and cytotoxic effects on aerobic and anaerobic faecal flora.

A novel specific immunoassay for plasma two-chain factor VIIa: investigation of FVIIa levels in normal individuals and in patients with acute coronary syndromes

We report the development of an enzyme-linked immunosorbent assay (ELISA) that is specific for factor VIIa (FVIIa). This assay uses a neoantigen specific capture antibody directed to the amino acid peptide sequence N terminal to the FVII cleavage activation site. The antibody exhibits approximately 3,000-fold greater reactivity to FVIIa than FVII on a molar basis. Experiments using plasma with added (exogenous) human FVIIa gave quantitative recovery in the ELISA over a range of 0.20 to 3.2 ng/mL of FVIIa. The intra- and inter-assay coefficient of variation (CVs) of the ELISA are 4.5% and 9.8%, respectively. The ELISA shows excellent correlation (r = .99) with a functional assay (using recombinant soluble tissue factor) in detecting FVIIa added to plasma over the range 0.05 to 18.0 ng/mL. However, a major discrepancy exists between the two assays when normal endogenous plasma concentrations of FVIIa are measured. Using normal plasma (n = 14) the functional assay reported 3.10 +/- 0.30 ng/mL (mean +/- SE) whereas only 0.025 +/- 0.010 ng/mL was detected in the same samples by the immunoassay. Patients (n = 43) presenting with acute coronary syndromes (myocardial infarction and unstable angina) exhibited elevations (P < .05) in immunologically detected FVIIa, 0.093 +/- 0.013 ng/mL (mean +/- SE) compared to patient controls (n = 20) contemporaneously admitted with noncardiac chest pain, 0.048 +/- 0.007 ng/mL (mean +/- SE). These elevations in the acute coronary syndromes were accompanied by increased (P < .05) and correlating prothrombin fragment F1 + 2 levels (Spearman correlation coefficient rs = .4, P < .01), demonstrating that thrombin generation is certainly associated with, and may even be caused by, extrinsic pathway activation.

Pharmacokinetics of a new nitroderivative of acetylsalicylic acid after a single dose in rats

The pharmacokinetics of a new ASA-nitroderivative compound, NCX 4016 (ASA-NO2), was evaluated using an HPLC method. After single equimolar doses of ASA (35 mg kg(-1)) or ASA-NO2 (65 mg kg(-1)), no detectable levels of these compounds have been observed in rat plasma samples. SA peak levels were obtained at 3 h and 6 h after ASA and ASA-NO2 administration respectively. The elimination rate constants of SA were similar after ASA and ASA-NO2, suggesting a similar elimination phase of this metabolite in rats. From these data it is evident that ASA-NO2 is slowly metabolized in ASA, which is rapidly converted to SA.

[Pain in the extremities as a symptom of the onset of Guillain-Barré syndrome in infancy]

Guillain-Barré syndrome's diagnosis is not usually difficult, but diagnostic difficulty occurs for the variable initial presentation. Pain may be predominant as an initial symptom. Pain may be the primary complaint in the week preceding the onset of paralysis in some children. When irritability and withdrawal from child's usual activities is predominant the clinician is first concerned about an encephalopathic process. When the primary problem at presentation is limb and back pain the pathology appears to be in the musculoskeletal rather than in neurological system. The awareness of this presentation of Guillain-Barré syndrome will eliminate delay in diagnosis.

High purity factor IX and prothrombin complex concentrate (PCC): pharmacokinetics and evidence that factor IXa is the thrombogenic trigger in PCC

Recent studies using assays for surrogate markers of thrombogenicity in man have demonstrated that activation of the coagulation system occurs following infusion of clinical doses of prothrombin complex concentrates (PCC) but not after the same doses of high-purity factor IX concentrates (HP-FIX) in patients with haemophilia B. Here we have investigated the mechanism of such thrombogenesis by applying assays that detect early-through to late-events in coagulation system activation in a pharmacokinetic cross-over study of 50 IU/kg PCC and a new HP-FIX product in haemophilia B patients. Satisfactory recoveries and half-lives were observed for both concentrates. HP-FIX caused no increases in thrombin-antithrombin III complex (TAT), prothrombin activation peptide fragment F1+2 (F1+2), factor X activation peptide (FXAP) or factor VIIa (FVIIa). In contrast the same dose of factor IX in the form of PCC was followed by significant increases over pre-infusion levels of TAT, F1+2 and FXAP, but not FVIIa. Elevations of FIXAP occurred after both HP-FIX and PCC but did not reach normal levels and were attributed to normalisation of the FIX concentration in those patients whose levels of FIXAP were initially low. We conclude that the thrombogenic trigger associated with PCC infusion occurs at the level of factor X activation. In the absence of any increase in FVIIa, we would attribute this to the likely presence of FIXa in the PCC.

Vasodilating properties of a new non-steroidal anti-inflammatory drug, nitroflurbiprofen, on rat aortic rings

The effects of nitroflurbiprofen (NFP), a new non-steroidal anti-inflammatory drug containing a nitroxybutyl moiety, on rat aortic rings were compared with those of flurbiprofen (FP) and glyceryl trinitrate (GTN). NFP and GTN relaxed, in a dose-dependent manner, either intact or rubbed aortic rings precontracted with epinephrine. Pretreatment with FP did not influence the relaxant activity of NFP in both endothelium-intact and -denuded arteries. In unrubbed preparations, FP did not affect contraction induced by epinephrine, while in rubbed ones a moderate relaxation was observed. Methylene blue and oxyhaemoglobin completely reversed the vasodilating effect of NFP in both rubbed and unrubbed preparations. Moreover, the addition of cysteine 5 mmol l-1 at the end of the cumulative application of NFP resulted in a further relaxation of aortic rings. These results indicate that NFP possesses vasodilatory activity which appears to be dependent on the release of nitric oxide or nitric oxide derivatives.