Involvement of the Wiskott-Aldrich syndrome protein (WASp) in promoting cell activation requires its release from autoinhibitory structural constraints and has been attributed to WASp association with activated cdc42. Here, however, we show that T cell development and T cell receptor (TCR)-induced proliferation and actin polymerization proceed normally in WASp Ϫ / Ϫ mice expressing a WASp transgene lacking the cdc42 binding domain. By contrast, mutation of tyrosine residue Y291, identified here as the major site of TCR-induced WASp tyrosine phosphorylation, abrogated induction of WASp tyrosine phosphorylation and its effector activities, including nuclear factor of activated T cell transcriptional activity, actin polymerization, and immunological synapse formation. TCR-induced WASp tyrosine phosphorylation was also disrupted in T cells lacking Fyn, a kinase shown here to bind, colocalize with, and phosphorylate WASp. By contrast, WASp was tyrosine dephosphorylated by protein tyrosine phosphatase (PTP)-PEST, a tyrosine phosphatase shown here to interact with WASp via proline, serine, threonine phosphatase interacting protein (PSTPIP)1 binding. Although Fyn enhanced WASpmediated Arp2/3 activation and was required for synapse formation, PTP-PEST combined with PSTPIP1 inhibited WASp-driven actin polymerization and synapse formation. These observations identify key roles for Fyn and PTP-PEST in regulating WASp and imply that inducible WASp tyrosine phosphorylation can occur independently of cdc42 binding, but unlike the cdc42 interaction, is absolutely required for WASp contributions to T cell activation.

The amino acid sequence at the F2/F1 cleavage site of the F0 fusion protein of 17 strains of Newcastle disease virus (NDV) was deduced from sequencing a 32 nucleotide area of the genome by reverse transcription and polymerase chain reaction (PCR) techniques. With the addition of sequences at the same area previously published for 9 other viruses comparisons were made of a total of 26 NDV strains and isolates (11 of low virulence, 15 of high virulence or mesogenic) covering ten antigenic groups determined by reactions with monoclonal antibodies. All the virulent viruses and the mesogenic strain Komarov showed the amino acid sequence 112R/K-R-Q-K/R-R116 for the C-terminus of the F2 protein and phenylalanine (F) at the N-terminus of the F1 protein, residue 117. The mesogenic isolate of the antigenic variant NDV responsible for the recent panzootic in racing pigeons, often termed "pigeon paramyxovirus type 1", examined in this study had the sequence 112G-R-Q-K-R-F117. The deduced amino acid sequence in the corresponding region of all viruses of low virulence was 112G/E-K/R-Q-G/E-R-L117. The virulent virus, PMV-1/chicken/Ireland/34/90 (34/90), which had a close antigenic relationship to a group of avirulent viruses, three of which were examined in the present study as representatives of the monoclonal antibody group H, showed between 4-6 nucleotide differences from these viruses in the 32 nucleotide region studied. These resulted in differences in the deduced amino acid sequence at residue 112 E-->K, 115 E-->K and 117-->F, giving 34/90 a typical virulent virus motif at the cleavage site. Despite the extremely small portion of the genome studied there were several areas which appeared characteristic for 34/90 and the three group H viruses of low virulence, which suggests that they may have arisen from the same gene pool.

Candida lusitaniae associated with infection in a patient with acute myelogenous leukemia developed resistance to amphotericin B during systemic treatment of the patient. The organism, when isolated initially, was inhibited by 0.31 μg of amphotericin B per ml in yeast nitrogen base agar, but when isolated (20 days later) just antemortem and postmortem, required 100 and 50 μg/ml, respectively, for complete inhibition at 48 h.

Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) is the preferred method of confirming the administration of exogenous testosterone by athletes. This relies on synthetic testosterone preparations being depleted in (13) C compared to natural testosterone. There is concern, however, about the existence of synthetic testosterone products that are unexpectedly (13) C-enriched and which may allow athletes to circumvent the current GC-C-IRMS test. Further to the reported studies of legitimate pharmaceutical-grade testosterone products, a detailed analysis of seized materials from border-level seizures was required to obtain intelligence concerning trends in 'black market' testosterone manufacture and distribution. The sample set collected for this study between 2006 and 2009 inclusive provided a δ(13) C range (n = 266) of -22.9‰ to -32.6‰ with mean and median values of -28.4‰ and -28.6‰, respectively. Within this distribution there were 24 samples (9%) confirmed to have δ(13) C values in the range reported for endogenous urinary steroid metabolites (≥ -25.8‰). The benefit of δ(13) C profiling for testosterone preparations was demonstrated by the ability to identify specific seized products that can be target tested for future intelligence purposes. In addition, the potential of stable hydrogen isotope ratio ((2) H/(1) H; δ(2) H) discrimination to complement δ(13) C analysis was investigated. Methodologies for the determination of δ(2) H values by gas chromatography-thermal conversion-isotope ratio mass spectrometry (GC-TC-IRMS) were developed to provide a δ(2) H range (n = 173) of -177‰ to -268‰ with mean and median values of -231‰ and -234‰, respectively.

Newcastle disease (ND) virus (APMV-1) isolates submitted to the International Reference Laboratory for ND were characterised antigenically by their ability to cause binding of mouse monoclonal antibodies (mAbs) to cell cultures infected with the isolate. Since the availability of the mAbs 1526 viruses have been examined using a panel of nine mAbs and 818 with an extended panel of 26 mAbs. Using the nine mAb panel a total of 14 different patterns was seen and viruses grouped by the same pattern showed relationships with each other which were either biological, temporal or geographical or more than one of these. There was a marked tendency of viruses placed in the same group to show similar virulence for chickens. Extension of the panel to 26 mAbs produced 39 distinct patterns, although some of these were seen with only a single virus. Again, viruses inducing similar binding patterns shared similar properties and some binding patterns were specific for viruses causing discrete epizootics. Cluster analysis of the mAb binding patterns did not produce concise, discrete groupings, but did emphasise some relationships between virus properties and antigenicity. Examples of the usefulness of this approach were the ability to link two important outbreaks to the contamination of stored food by infected feral pigeons, and the demonstration of two separate viruses responsible for outbreaks in countries of the European Union during 1991 to 1994 thus preventing erroneous epizootiological tracing.

Antigenic characterisation of two highly virulent virus isolates from outbreaks of Newcastle disease on two closely connected farms in County Monaghan, Republic of Ireland, in 1990 showed the viruses to be indistinguishable but unlike other Newcastle disease viruses so far tested. However, they appeared to be antigenically closest to avirulent viruses isolated from waterfowl from several countries and from chickens in Northern Ireland in 1986. Despite the antigenic differences, chickens vaccinated with a live commercial Hitchner B1 vaccine were protected against intramuscular challenge with one of the virulent isolates.

Conventional chemical profiling of methylamphetamine has been used for many years to determine the synthetic route employed and where possible to identify the precursor chemicals used. In this study stable isotope ratio analysis was investigated as a means of determining the origin of the methylamphetamine precursors, ephedrine and pseudoephedrine. Ephedrine and pseudoephedrine may be prepared industrially by several routes. Results are presented for the stable isotope ratios of carbon (delta(13)C), nitrogen (delta(15)N) and hydrogen (delta(2)H) measured in methylamphetamine samples synthesized from ephedrine and pseudoephedrine of known provenance. It is clear from the results that measurement of the delta(13)C, delta(15)N and delta(2)H stable isotope ratios by elemental analyzer/thermal conversion isotope ratio mass spectrometry (EA/TC-IRMS) in high-purity methylamphetamine samples will allow determination of the synthetic source of the ephedrine or pseudoephedrine precursor as being either of a natural, semi-synthetic, or fully synthetic origin.

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