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We describe two mouse mAb recognizing the putative chicken homologue of mammalian CD2 Ag and provide evidence for both structural and functional conservation between the avian and mammalian CD2 molecules. The antibodies were T cell-specific and immunoprecipitated a single diffuse band of Mr 40,000 from lysates of surface-labeled chicken thymocytes and peripheral T cells. Removal of N-linked carbohydrate with endo-beta-N-acetylglucosaminidase F revealed the core protein size of Mr 25,000. A rabbit antiserum raised against a synthetic peptide (CD2-300), composed of 18 amino acid residues of the conserved cytoplasmic domain of human, mouse, and rat CD2, precipitated an Ag similar to chicken CD2. Sequential precipitation with CD2-300 antiserum indicated the conservation of an avian and mammalian CD2 epitope. CD2 expression on thymocytes starts at day 11 of embryonic development, and, during subsequent development, thymic gamma delta cells are all CD2+, whereas most peripheral gamma delta-T cells lack CD2. Functional conservation between the chicken and mammalian CD2 molecules was demonstrated by the induction of DNA synthesis in chicken thymocytes and peripheral T cells with the combination of anti-CD2 mAb and PMA.

A digital motion control system is presented with primary applications in automatic elevator doors. Digital signal processing methods are used for generating exponential waveforms for the drive motor. The unit keeps track of the actual speed of motion and the corresponding door position. Thus the time consumed by door motion is minimized, and smooth acceleration and deceleration phases are achieved. The proposed algorithm results in an efficient bit-serial application specific IC (ASIC) implementation. >

The well-known noise problem in digital differentiation is addressed by means of using adaptive digital filtering for signal pre-processing. Rapidly responding differentiators with low-noise output can be constructed by using the adaptive filter in a predictor configuration. As the prefilter is adaptive, the approximation is more flexible than polynomial fitting. The recursive least-squares adaptive algorithm is used for prediction.

A flexible method of reducing white noise in measurement signals by means of real-time digital filtering is presented. Compared to the widely used averaging filter, the new approach significantly reduces the delay of the step response of a filter, measured typically al the 50% level of the full step. The optimum filter coefficients are obtained analytically as a function of a single weighting parameter.

Hilbert transformers are one of the very important special classes of finite impulse response (FIR) filters used in signal processing applications. A method is presented to synthesize Hilbert transformers by using wideband linear-phase FIR filters with a piecewise-polynomial-sinusoidal impulse response. The proposed method is based on merging the earlier synthesis scheme proposed by the authors with the method proposed by Chu and Burrus and by modifying it by using an arbitrary number of separately generated center coefficients instead of none used in the method by Chu-Burrus. The desired impulse response is created by using a parallel connection of several filter branches and by adding an arbitrary number of center coefficients to form it. The arithmetic complexity of these filters is proportional to the number of branches, the common polynomial order for each branch and the number of separate center coefficients. The filter coefficients are optimized by using linear programming. An example shows the benefits of these filters compared to the frequency-response masking approach (FRM) with regard to reducing the number of coefficients as well as arithmetic complexity.

More and more processors can be fabricated on a single chip today. But management of this increasing parallelism is still in a research phase. This paper introduces the idea of the hybrid data-driven control-flow processor. The hybrid processor has support for object-oriented programming methods to help programmers to manage parallelism in the network of the hybrid processors. All programs, including the operating system, can be divided to several objects and thus spread over the network. This way everything is executed truly concurrently in the network of the hybrid processors.

Design and implementation of a class of fractional-order digital FIR differentiators is described. The design approach is based on optimizing the white noise attenuation of the differentiator while assuming a polynomial signal model of a limited order. The approach avoids the noise amplification problem of many other approximations by limiting the differentiation bandwidth. A computationally efficient recursive structure makes it possible to implement the FIR differentiator with very few multipliers regardless of the length of the impulse response.

This paper presents a rapid approach for designing and implementing stack filters in the hardware. The design cycle is speeded up using VHDL based synthesis and parametrizable models. To achieve a short implementation time, the filters are prototyped using Field Programmable Cate Arrays (FPGAs) from Xilinx Inc. The main emphasis is on finding out the efficient ways of describing nonlinear filter structures on VHDL, and mapping to the dedicated FPGA architecture. The performance and logic capacity studies are used to find out reasonable algorithms and applications to be implemented with FPGAs.

An efficient noise reduction technique for unevenly sampling polynomial predictors is introduced. Our prediction procedure is based on Newton's classical divided-difference interpolation formula. The optimal smoothing filter is derived for the linear Newton predictor, and it is shown to perform well also in nonlinear prediction. The improved algorithm finds applications, for example, in predictive upsampling or synchronization of unevenly spaced samples.

An application specific signal processor architecture supporting nonlinear operations has been designed. The most essential block of the processor core is a programmable order statistic filter, for which the most feasible structure consists of a switch array and a programmable positive Boolean function. The core architecture supports rank order filters, linear and hybrid filtering.

The signs shown by 96 dogs recovering at home after day-case soft tissue operations were assessed by their owners for three days. On the day of the operation there were behavioural changes in all the animals, but by two days after the operation changes in behaviour were detected in only 85 per cent of them. The most common changes were in the dogs' demeanour and their way of moving; there were decreases in overall activity and playfulness, and increases in contact seeking. The dogs also showed signs of pain: the highest ratings were observed on the day of the operation, when the median value on a visual analogue scale from 0 to 100 mm was 43 mm, with a range from 0 to 95 mm. The type of operation significantly affected the signs observed.

We introduce an evolutionary programming based method for designing robust and computationally efficient adaptive bandpass filters. These predictive filters are optimized for generating current references in active power filters (APFs). The accuracy (phase/amplitude) of the reference current is crucial in current injection type systems, because it directly affects the harmonics reduction ability of the APF. Our digital filtering approach has the following advantages: selective bandpass response, efficient attenuation of specific harmonic components, capability to handle typical frequency alteration, small number of multiplications, and structural simplicity. In an illustrative example, the total harmonic distortion of an artificial current waveform was reduced from 36.7% to less than 3.7% within the line frequency range 49-51 Hz. The proposed scheme is a combination of the hard computing (HC) type multiplicative general parameter method and evolutionary programming that is a constituent of soft computing (SC). Such fusion thinking is emerging among researchers and engineers, and it can potentially lead to efficient combinations of HC and SC methodologies - both on the algorithm level and on the system level.

We introduce a genetic algorithm (GA)-based method for structural optimization of multiplicative general parameter (MGP) finite impulse response (FIR) filters. These computationally efficient reduced-rank adaptive filters are robust, suitable for predictive configurations, and they have numerous applications in 50/60 Hz power systems instrumentation. The design process of such filters has three independent stages: Lagrange multipliers-based optimization of the sinusoid-predictive basis filter, genetic algorithm-based search of optimal FIR tap cross-connections and, finally, the online MGP-adaptation phase guided by variations in signal statistics. Thus, our multi-stage design procedure is a complementary fusion of hard computing (HC) and soft computing (SC) methodologies. Such advantageous fusion (or symbiosis) thinking is emerging among researchers and practicing engineers, and it can potentially lead to competitive combinations of individual HC and SC methods.

Linearly constrained LMS adaptive filter algorithms are considered for digital processing of 50/60 Hz line-frequency signals. The constraints are set such that the primary sinusoidal waveform is guaranteed to pass the filter unaltered, and the adaptation is used to dynamically optimize the noise attenuation properties. In order to reduce the computational complexity of the constrained algorithm, selective coefficient updating is used, and the update formulas are derived accordingly. The approach is efficient in suppressing noise and harmonics in applications such as reactive power estimation and zero-crossing detection.

This paper presents a self-timed, asynchronous, parallel finite impulse response (FIR) filter architecture capable of high-speed operation. Using self-timed, parallel structures even slow calculation blocks, such as simple multiplier-accumulators (MACs), can be used to implement high-speed filters. The building blocks are implemented using specific current-sensing completion detection (CSCD) standard cells also presented in this paper. The simulation results are very promising and especially the design of the control revealed several pitfalls and possibilities that require specific solutions when designing asynchronous circuits.

Least-squares design of FIR filters is considered for a structure consisting of a tapped cascaded interconnection of identical subfilters. By using computationally efficient substructures, savings are achieved in the number of multiplications, as compared to direct form designs of comparable integrated squared error. Analytical formulas are derived for the optimum tap coefficients, based on the time-domain composition of the overall impulse response. Examples of linear-phase lowpass and bandpass filter design are given.

This paper shows how the current-sensing completion detection (CSCD) method can be applied for standard cell based digital system design. With the proposed method, conventional synchronous CMOS logic circuit blocks can easily be modified for self-timed asynchronous operation. To illustrate the usage of the method a self-timed CSCD multiplier-accumulator (MAC) was constructed. Simulation results and VHDL synthesized layouts of the CSCD MAC show that the CSCD method and the various proposed design practices can be used for the construction of self-timed asynchronous logic systems.

The effects of propofol infusion were compared with propofol/isoflurane anaesthesia in six beagles premedicated with 10 microg/kg intramuscular (i.m.) dexmedetomidine. The suitability of a cold pressor test (CPT) as a stress stimulus in dogs was also studied. Each dog received isoflurane (end tidal 1.0%, induction with propofol) with and without CPT; propofol (200 microg/kg/min, induction with propofol) with and without CPT; premedication alone with and without CPT in a randomized block study in six separate sessions. Heart rate and arterial blood pressures and gases were monitored. Plasma catecholamine, beta-endorphin and cortisol concentrations were measured. Recovery profile was observed. Blood pressures stayed within normal reference range but the dogs were bradycardic (mean heart rate70 bpm). PaCO2 concentration during anaesthesia was higher in the propofol group (mean57 mmHg) when compared with isoflurane (mean52 mmHg). Recovery times were longer with propofol than when compared with the other treatments. The mean extubation times were 8 +/- 3.4 and 23 +/- 6.3 min after propofol/isoflurane and propofol anaesthesia, respectively. The endocrine stress response was similar in all treatments except for lower adrenaline level after propofol infusion at the end of the recovery period. Cold pressor test produced variable responses and was not a reliable stress stimulus in the present study. Propofol/isoflurane anaesthesia was considered more useful than propofol infusion because of milder degree of respiratory depression and faster recovery.

The well-known noise problem in digital differentiation is addressed by means of using adaptive digital filtering for signal preprocessing. Rapidly responding differentiators with low-noise output can be constructed by using the adaptive filter in a predictor configuration. As the prefilter is adaptive, the approximation is much more flexible than polynomial fitting, for instance, and different types of signals can be processed. The RLS algorithm is used for prediction because of its good convergence properties.

A digit-serial design of a third order wave digital filter using a mixture of static and TSPC logic styles is presented. A fixed-coefficient digit-serial multiplier has been developed and used in the design. The design offers a small area, large density, and low power consumption comparing with previously published results. Digit-serial computation style is discussed and different computational styles are compared with regard to area, speed, and power consumption.

An adaptive digital notch filter is considered for 50/60 Hz line frequency signal processing. An adaptive algorithm allows tracking of the main frequency component such that the notch frequency is the only changing parameter. Since the power line frequency is known to within a narrow tolerance band, it is possible to apply soft or hard limiting on the notch frequency. Soft and hard limiting are compared for Laplacian noise, and the effect of filtering is investigated for a signal with strong harmonic contents.

Two computationally efficient recursive structures are introduced for generating arbitrary polynomial responses. For an Mth-order polynomial, M+1 coefficients are required to obtain the desired shape regardless of the length of the response. For truncating the response, M+1 additional integer-valued coefficients are needed. The proposed structures can be used in a straightforward manner for constructing computationally efficient predictors as well as linear-phase FIR filters with piecewise-polynomial impulse responses.

The two alternative design approaches discussed in this paper are dedicated DSP architectures and the core processor based design methodology. By the development of area-efficient high resolution A/D converters, it has become feasible to integrate the analog interface on the same chip with the DSP operations. However, lack of an interdisciplinary high-level CAE environment tends to lengthen the design times of DSP-ASICs. >

A digital motion control system with primary applications in automatic elevator doors is presented. Digital signal processing methods are used for generating exponential waveforms for the drive motor. The unit keeps track of the actual speed of motion and the corresponding door position. Thus, the time consumed by door motion is minimized, and smooth acceleration and deceleration phases are achieved. The proposed algorithm results have been implemented in an efficient bit-serial ASIC implementation. >

Differentiation by means of digital signal processing is needed for estimating the rate of change or slope of digitized signals in many motion control and automation applications, including acceleration measurement. Since the ideal differentiator is unrealizable, several kinds of approximations have been proposed in the literature. In this work, we propose a digital differentiation scheme which is flexible and in many cases avoids the unfavourable noise properties of wideband approximation approaches. This is achieved by cascading an integrator and a FIR filter in an adaptive loop such that the filter adapts as an application-specific differentiator. Examples of operation with different signal classes are given, including piecewise polynomials, frequently encountered in motion control applications.

A digital filter design and optimization method for sampling rate alteration of narrow-band signal waveforms is presented, using the sinusoidal signal model. The resulting filters are linear-phase finite impulse response filters which remove the aliasing or imaging frequency components before the sampling rate is changed. Two approaches are discussed according to whether the sample rate is changed by an integer factor M or a rational factor M/L. The proposed narrow-band multirate techniques can be applied in digital measurement or control systems in industrial electronics.

Acceleration feedback can improve the performance of motion control in motor drives. Acceleration control is, however, seldom implemented in practical drive systems due to the unsatisfactory results of most acceleration measurement methods. In this paper, we introduce a computationally efficient (Finite Impulse Response) filter-based algorithm which makes it possible to differentiate the polynomial-like velocity signal with optimal white noise attenuation. The proposed signal processing algorithm does not delay the acceleration signal but, instead, the prediction step can be freely adjusted to compensate for various delays in the physical implementation. Our algorithm can be implemented by utilizing recursive structure so that the amount of multiplications and additions required does not depend on the filter length. No additional hardware is required to implement the algorithm because it can be programmed as part of the control software. The performance of the new algorithm is evaluated by applying it to a simulated motion control application.

A new multistage digital filter is proposed for 50 Hz line frequency signal processing in zero-crossing detectors and synchronous power systems. The purpose of the filter is to extract the fundamental sinusoidal signal from noise and impulsive disturbances so that the output is accurately in phase with the primary input signal. This is accomplished with a cascade of a median filter, a linear-phase FIR filter and a phase corrector. A 10 kHz output timing resolution is achieved by up-sampling with a customized interpolation filter.

We describe two adaptive multistage digital filters for line-frequency signal processing in zero-crossing detectors and synchronous power systems. These filters combine a median filter with adaptive, predictive filters, thus making it possible to extract the sinusoidal signals from noise and strong disturbances without phase shifting the primary frequency component. The median filter is used as a prefilter because it can efficiently remove deep commutation notches from the waveform. Adaptation allows the filter to track the time-varying line-frequency and avoids the misadjustment problem encountered with a fixed predictive filter. An FIR (Finite Impulse Response) filter-based predictor is attractive when there are large frequency variations, and an IIR (Infinite Impulse Response) filter-based cascade predictor has better attenuation characteristics for undesired frequency components.

This paper presents an adaptive estimator for predictive filtering of smoothly-varying signals. The hybrid estimator uses a multilayer backpropagation neural network as a derivative detector that identifies whether the first, second, and third derivative exist in the incoming signal. The detector is used to control the path multipliers of the estimator. Therefore, the estimator order can be changed dynamically when the piecewise polynomial signal changes its characteristics in different time segments. The use of a neural network requires to determine the optimal number of input and hidden nodes needed for successful derivative detection. In this paper, a method of Predictive Minimum Description Length (PMDL) has been used to solve this problem so that over-fitting and under-fitting can be penalized automatically. This results in a network that has both excellent generalization capability and moderate computational complexity

A class of analog continuous-time filters is introduced, having predictive properties for specified narrow-band signal models, such as low-order polynomials or sinusoids. Such filters are designed by using model transfer functions designed in the discrete-time domain. 2- to s-domain mapping is done using the inverse bilinear transformation. Predictive analog filters are implemented using active-RC structures. Several examples of constructed and measured prototypes are given, using the state-variable structure for biquads, and a single-op-amp structure for real poles and zeros.

A class of computationally efficient adaptive algorithms for transversal filters is discussed. The algorithms, which are based on the so-called general parameter method, use typically one or a few dynamically adjusted parameters, each to be added to a block of coefficients of a fixed basis FIR filter. Thus the overall filter is adapted so that the output error is minimized. The adaptive extension can be constructed as an 'add-on' element to be used in parallel with fixed-coefficient filters. An efficient implementation structure is proposed, and the stability and convergence properties of the multiple-parameter algorithm are analyzed.

The FPGA design for both one- and two-dimensional order statistic filters is developed based on an efficient approach for implementing such filters in the binary domain. The order statistic filters are configurable so that different order statistic filtering functions can be realized using the same structure. The design was completed in an integrated computer-aided design environment. The design cycle is shortened by using VHDL based synthesis and FPGA technology.

Although linear filters have been the dominating filter class throughout the history of digital signal processing, not all signal processing problems can be satisfactorily addressed through the use of linear filters and in some cases nonlinear filters outperform linear filters. In this paper, we present a design with FPGAs of an efficient architecture for a wide class of nonlinear filters called stack filters. The functional block of the architecture, which determines the filter's operation, is implemented as random access memory (RAM) so that the filter is programmable to realize an arbitrary stack filtering function. The design is completed in an integrated design environment, which provides a fast way to design, evaluate and implement different algorithms and architectures.

The efficiency and properties of nonlinear digital filters are difficult to quantify with formal methods. Therefore, determining the effects of a nonlinear digital filter on overall system performance often requires simulations or prototyping. This paper presents a fast way to design a configurable order statistic filter with field programmable gate arrays (FPGAs) in a unified computer-aided design environment. Based on an innovative architecture, a window size nine, eight-bit filter fits in a single small and inexpensive component.

We present the design and performance of an experimental cell constructed for matrix isolation studies of H and D atoms in solid H2/D2 films, which are created by molecular beam deposition at temperatures below 1 K. The sample cell allows sensitive weighing of the films by a quartz microbalance (QM) and their studies by magnetic resonance techniques in a strong magnetic field of 4.6 T. We are able to regulate the deposition rate in the range from 0.01 to 10 molecular layers/s, and measure the thickness with ≈0.2 monolayer resolution. The upper QM electrode serves as a mirror for a 128 GHz Fabry-Perot resonator connected to an electron spin resonance (ESR) spectrometer. H and D atoms were created by RF discharge in situ in the sample cell, and characterized by ESR and electron-nuclear double resonance. From the magnetic resonance measurements we conclude that the films are smooth and provide homogeneous trapping conditions for embedded atoms. The current sample cell design also makes it possible to calibrate the ESR signal and estimate the average and local concentrations of H and D radicals in the film.

CD5 is a transmembrane glycoprotein on all T cells and on a subpopulation of B cells. Based on the analysis of chicken CD5-cDNA we have previously shown that the structure of the CD5 protein is conserved between species. Here we report the isolation and chromosomal mapping of the chicken CD5 gene. The gene spans 3.4 kb and is extremely compact with a high GC-nucleotide content. There are 10 exons and the introns are spliced out similarly to those in the human CD5 gene. Each of the three extracellular scavenger receptor cysteine-rich (SRCR) domains is encoded as an exon of its own, as is the proline-rich hinge region that separates the first two membrane-distal SRCR domains. The fluorescence in situ hybridization (FISH) technique was used to map the gene to chromosome five. This is the first report describing the organization of the CD5 gene from a nonmammalian species.

Intraepithelial lymphocytes (IEL) of the small intestine are anatomically positioned to be in the first line of cellular defense against enteric pathogens. Therefore, determining the origin of these cells has important implications for the mechanisms of T cell maturation and repertoire selection. Recent evidence suggests that murine CD8 alpha alpha intestinal IELs (iIELs) can mature and undergo selection in the absence of a thymus. We analyzed IEL origin by cell transfer, using two congenic chicken strains. Embryonic day 14 and adult thymocytes did not contain any detectable CD8 alpha alpha T cells. However, when TCR(+) thymocytes were injected into congenic animals, they migrated to the gut and developed into CD8alphaalpha iIELs, while TCR(-) T cell progenitors did not. The TCR V beta 1 repertoire of CD8 alpha alpha(+) TCR V beta 1(+) iIELs contained only part of the TCR V beta 1 repertoire of total iIELs, and it exhibited no new members compared with CD8(+) T cells in the thymus. This indicated that these T cells emigrated from the thymus at an early stage in their developmental process. In conclusion, we show that while CD8 alpha alpha iIELs originate in the thymus, T cells acquire the expression of CD8 alpha alpha homodimers in the gut microenvironment.

Lysinuric protein intolerance (LPI) is characterized by defective cellular transport of the dibasic amino acids, secondary dysfunction of the urea cycle, aversion to dietary protein, failure to thrive, hepatosplenomegaly and osteoporosis. Because several patients have suffered from recurrent respiratory infections and/or severe generalized varicella, and a few have developed systemic lupus, vasculitis or other autoimmune diseases, we have now evaluated the function of patients' immune systems. Serum concentrations of one to three IgG subclasses were decreased in 10 of the 12 patients studied. Antibody titres against diphtheria, tetanus and Haemophilus influenzae (Hib) were below the detection limit of the assay in four, three and eight of the 11 patients examined, respectively. (Re)vaccination of these 11 patients led to satisfactory responses against tetanus, but two patients still failed to develop measurable antibodies against diphtheria, two against Hib and six against one or more of the three serotypes of 23-valent pneumococcus vaccine. The proportions of T cells of all lymphocytes and the proliferative responses of the peripheral blood mononuclear cells were normal. In conclusion, humoral immune responses in some patients with LPI are defective and these patients may benefit from intravenous immunoglobulin therapy.

In this prospective study we evaluated the multiple effects of long-term GM-CSF therapy on blood counts, granulocyte functions and disease progression in patients with chronic lymphocytic leukemia (CLL) with chronic neutropenia and recurrent bacterial infections. The treatment duration varied from 2 to 12 weeks. The neutrophil count was raised in all patients, by the median of 6.6-fold. The neutrophil level of 1.0 x 10(9)/l was usually reached after two weeks. The initial dose of GM-CSF was 5 microg/kg/day, and 1-7 microg/kg/day was required to maintain the neutrophil level above 1.0 x 10(9)/l. Granulocyte functions, i.e. chemiluminescence (CL), random migration, and fMLP-stimulated chemotaxis were initially depressed in all patients when compared to healthy controls. GM-CSF enhanced significantly CL even when given at small doses (less than 1 microg/kg/day), even lower than the dose required to promote granulopoiesis. We conclude that GM-CSF is effective in improving CLL associated chronic neutropenia and also enhances impaired granulocyte chemiluminescence. Thus, GM-CSF could be helpful for giving chemotherapy without neutropenic delays and for prophylaxis of infectious complications in CLL patients.

CTX, a cortical thymocyte marker in Xenopus, is an immunoglobulin superfamily (Igsf) member comprising one variable and one constant C2-type Igsf domain, a transmembrane segment and a cytoplasmic tail. Although resembling that of the TCR and immunoglobulins, the variable domain is not encoded by somatic rearrangement of the gene but by splicing of two half-domain exons. The C2 domain, also encoded by two exons, has an extra pair of cysteines. The transmembrane segment is free of charged residues, and the cytoplasmic tail (70 amino acids) contains one tyrosine and many glutamic acid residues. ChT1, a chicken homologue of CTX, has the same structural and genetic features, and both molecules are expressed on the thymocyte surface. We cloned new mouse (CTM) and human (CTH) cDNA and genes which are highly homologous to CTX/ChT1 but not lymphocyte specific. Similarity with recently described human cell surface molecules, A33 antigen and CAR (coxsackie and adenovirus 5 receptor), and a number of expressed sequence tags leads us to propose that CTX defines a novel subset of the Igsf, conserved throughout vertebrates and extending beyond the immune system. Strong homologies within vertebrate sequences suggest that the V and C2 CTX domains are scions of a very ancient lineage.

The chicken CD5 cDNA was isolated by COS cell expression cloning utilizing a novel mAb 2-191. The cDNA contains a 1422-nucleotide open reading frame encoding a mature protein with 32% and 30% identity to mouse and human CD5 polypeptides, respectively. The molecule consists of a 330-amino acid extracellular region with three repeats of the scavenger receptor cysteine-rich domain, a 29-amino acid hydrophobic transmembrane domain, and a 93-amino acid cytoplasmic tail. The cytoplasmic region contains motifs that are highly conserved between species, including several potential phosphorylation sites. The chicken CD5 is a 64-kDa phosphorylated glycoprotein with a protein core of 57 kDa as determined by immunoprecipitation and SDS-PAGE analysis. Alphabeta T cells express a homogeneously high level of CD5, whereas low or intermediate CD5 expression on gammadelta T cells depends on their tissue location. In contrast to human and mouse, CD5 is found at low levels on all chicken B cells. The high conservation of structural features, as well as signaling motifs, implies a conserved role for CD5 both in lymphocyte development and function.

Leukocyte functions were studied in 22 patients with chronic lymphocytic leukaemia (CLL) and were related to the patients' susceptibility to infections. In CLL patients with a history of infections, compared with CLL patients without infections or healthy controls, there were significant impairments of most granulocyte functions; random migration, N-formyl-methionylleucylphenylalanine (fMLP) and C5a stimulated chemotaxis and chemiluminescence response were decreased. No differences in these functions between CLL patients without infections and healthy controls were observed. Phagocytosis and intracellular killing of granulocytes were intact in all patients with CLL. By univariate analysis, neutrophil count and serum IgG level also predicted susceptibility to infections. By multivariate analyses, granulocyte chemotaxis and chemiluminescence remained as statistically significant predictors of infections. The lymphocyte functions (mitogen-induced lymphocyte proliferation and immunoglobulin production in vitro) were equally impaired in all patients with CLL and differed significantly from the respective functions in healthy control subjects. We conclude that impairments in granulocyte functions contribute to susceptibility to infections in CLL.

Gold sodium thiosulphate (GSTS) in patch test series commonly yields positive reactions. In this study of dental patients, the clinical relevance of these positive reactions, the suitability of gold compounds as patch test materials, and value of the lymphocyte proliferation test in gold contact allergy, were evaluated. The frequency of positive patch test reactions to GSTS was 12.4% in the dental series. Fifty-two patients, only two of whom were male, were studied. Thirteen (25%) had had symptoms from jewellery or dental restorations. However, in most cases gold allergy was subclinical. A 10% aqueous solution of gold sodium thiomalate (GSTM) was almost as good as 0.5% GSTS in petrolatum as a marker of gold contact allergy, but 0.001% potassium dicyanoaurate (PDCA) yielded a high percentage of false-negative results. Seventy-three per cent of the subjects with positive patch tests to GSTS responded to gold compounds in vitro in the lymphocyte proliferation test, whereas 13 controls without gold contact sensitivity were negative. Consistent results in skin and lymphocyte proliferation tests provide support for the concept that gold salt-induced 'allergic-like' reactions are truly allergic in nature.