Showing papers by "Université libre de Bruxelles published in 1988"
TL;DR: In this paper, it was shown that a map (f>:{M,g)-+(N,h) between Riemannian manifolds which is continuous and of class L\\ is harmonic if and only if it is a critical point of the energy functional.
Abstract: (1.1) Some of the main results described in [Report] are the following (in rough terms; notations and precise references will be given below): (1) A map (f>:{M,g)-+(N,h) between Riemannian manifolds which is continuous and of class L\\ is harmonic if and only if it is a critical point of the energy functional. (2) Let (M, g) and (N, h) be compact, and <̂ 0: (M, g) -> (N, h) a map. Then ^0 can be deformed to a harmonic map with minimum energy in its homotopy class in the following cases: (a) Riem ' f t ^0; (b) dim M = 2 and n2(N) = 0. (3) Any map 0O: S m -> S can be deformed to a harmonic map provided m ^ 7. More generally, suitably restricted harmonic polynomial maps can be joined to provide harmonic maps between spheres. (4) The homotopy class of maps of degree 1 from the 2-torus T to the 2-sphere S has no harmonic representative, whatever Riemannian metrics are put on T and S. (5) If in (2) M has a smooth boundary, then various Dirichlet problems have solutions in case (a) and (b); and also when the boundary data is sufficiently small.
551 citations
TL;DR: In this article, a new and alternative specification is put forward and tested, which assumes that in the investment decision process, foreign locations are in competition not only with each other but also with the home country of the investor.
538 citations
University of Edinburgh1, Curie Institute2, University of Gothenburg3, University of Oslo4, Netherlands Cancer Institute5, Institut Gustave Roussy6, Université libre de Bruxelles7, University of Glasgow8, University of Zurich9, Russian Academy10, University of Alabama at Birmingham11, Martin Luther University of Halle-Wittenberg12
TL;DR: The absence ofLocal recurrence in the group of patients with a primary melanoma thinner than 1 mm and the very low rate of local recurrences indicate that narrow excision is a safe and effective procedure for such patients.
Abstract: Although wide surgical excision is the accepted treatment for thin malignant melanomas, there is reason to believe that narrower margins may be adequate. We conducted a randomized prospective study to assess the efficacy of narrow excision (excision with 1-cm margins) for primary melanomas no thicker than 2 mm. Narrow excision was performed in 305 patients, and wide excision (margins of 3 cm or more) was performed in 307 patients. The major prognostic criteria were well balanced in the two groups. The mean thickness of melanomas was 0.99 mm in the narrow-excision group and 1.02 mm in the wide-excision group. The subsequent development of metastatic disease involving regional nodes and distant organs was not different in the two groups (4.6 and 2.3 percent, respectively, in the narrow-excision group, as compared with 6.5 and 2.6 percent in the wide-excision group). Disease-free survival rates and overall survival rates (mean follow-up period, 55 months) were also similar in the two groups. Only three patients had a local recurrence as a first relapse. All had undergone narrow excision, and each had a primary melanoma with a thickness of 1 mm or more. The absence of local recurrence in the group of patients with a primary melanoma thinner than 1 mm and the very low rate of local recurrences indicate that narrow excision is a safe and effective procedure for such patients.
445 citations
TL;DR: It is shown that the variabilities in interbeat intervals are not random but exhibit short range correlations governed by deterministic laws, which may be related to the accelerating and decelerating physiological processes.
Abstract: With the help of several independent methods of nonlinear dynamics, the electrocardiograms (ECG) of four normal human hearts are studied qualitatively and quantitatively. A total of 36 leads were tested. The power spectrum, the autocorrelation function, the phase portrait, the Poincare section, the correlation dimension, the Lyapunov exponent and the Kolmogorov entropy all point to the fact that the normal heart is not a perfect oscillator. The cardiac activity stems from deterministic dynamics of chaotic nature characterized by correlation dimensions D 2 ranging from 3.6 to 5.2. Two different phase spaces are constructed for the evaluation of D 2: the introduction of time lags and the direct use of space vectors give similar results. It is shown that the variabilities in interbeat intervals are not random but exhibit short range correlations governed by deterministic laws. These correlations may be related to the accelerating and decelerating physiological processes. This new approach to the cardiac activity may be used in clinical diagnosis. Also they are valuable tools for the evaluation of mathematical models which describe cardiac activity in terms of evolution equations.
358 citations
TL;DR: Molecular clones of NLK have been expressed in monkey COS cells and the product was shown to have the same biological and biochemical properties as the extracted protein, and its amino-acid sequence is 90% homologous to the sequence of mouse neuroleukin.
Abstract: Neuroleukin (NLK) is a protein of relative molecular mass (Mr) 56,000 (56K) secreted by denervated rat muscle1 and found in large amounts in muscle, brain, heart and kidneys2. The protein is a neurotrophic factor for spinal and sensory neurons2 and a lymphokine product of lectin-stimulated T-cells3. It also induces immunoglobulin secretion by human mononuclear cells3. Molecular clones of NLK have been expressed in monkey COS cells and the product was shown to have the same biological and biochemical properties as the extracted protein. NLK is abundant in muscle, brain and kidney, but is active at concentrations of 10−9 to 10−11 M, similar to those for other polypeptide factors. We have cloned the gene for pig muscle phosphohexose isomerase (PHI) (EC 5.3.1.9) which catalyses the conversion of glucose-6-phosphate to f ructose-6-phosphate, an obligatory step in glycolysis, and determined its amino-acid sequence. Surprisingly, it is 90% homologous to the sequence of mouse neuroleukin.
240 citations
TL;DR: The pathology of the BLV-induced disease, most notably the absence of chronic viraemia, a long latency period and lack of preferred proviral integration sites in tumours, is similar to that of adult T-cell leukaemia/lymphoma induced by HTLV-I.
194 citations
TL;DR: The results show for the first time that an immune state against HIV can be obtained in man using the V25 recombinant vaccinia virus/bacteriophage T7 expression system.
Abstract: The first experimental immunization of humans against the AIDS retrovirus, HIV-1, was started in a series of HIV seronegative, healthy volunteers in November 1986. For the primary vaccination recombinant vaccinia virus (V25) expressing the complete gp160 env protein of the HTLV-IIIB strain of HIV-1 was introduced by scarification. This elicited a weak primary response which we subsequently attempted to enhance by additional immunizations (boosting), using four different immunization protocols. We report here that intravenous injection of paraformaldehyde-fixed autologous cells infected in vitro with V25 (individual D.Z.) gave the best results. This individual received second and third boosts of intramuscular gp160 derived from an HTLV-IIIB clone using the hybrid vaccinia virus/bacteriophage T7 expression system. An anamnestic humoral and cellular immune reaction was achieved for over one year after the original vaccination, with high levels of antibodies to the viral envelope, and neutralizing antibodies against divergent HIV-1 strains such as HTLV-IIIB and HTLV-IIIRF (also called HTLV-III HAT) after the first boost. In addition, group-specific cell-mediated immunity and cell-mediated cytotoxicity against infected T4 cells were obtained after the primary vaccine and enhanced by the boosts. Finally, skin tests showed both immediate and delayed hypersensitivity to gp160 in vivo. Although this protocol is not practical for a large scale vaccine trial, our results show for the first time that an immune state against HIV can be obtained in man.
186 citations
TL;DR: The authors analyzes contracts as means of strategic commitment, that is, commitment against outside parties to the agreement, and considers the example of an incumbent firm which enters a contractual relationship with its workers in order to deter entry.
Abstract: The paper analyzes contracts as means of strategic commitment, that is, commitment against outside parties to the agreement. It considers the example of an incumbent firm which enters a contractual relationship with its workers in order to deter entry. It assumes away the possibility for the parties to precommit not to make Pareto-improving renegotiations of the agreement once entry has taken place. Under symmetric information, the contract is thus found to be useless for entry deterrence. If the incumbent firm or workers possess some private information, excessive post-entry production levels can however be sustained ex post, since output reductions may not be incentive compatible. While information asymmetries are usually welfare-decreasing when the goal is optimal risk sharing, they can thus be welfare-improving for the contracting parties when commitment against outsiders is the goal of the contract. The role of the renegotiation process as a constraint on sustainable agreements is stressed in the paper, and the general relevance of strategic contractual commitment is discussed.
175 citations
TL;DR: It is shown that intermittent systems of Manneville as well as some countable Markov chains may be sporadic and, furthermore, that the dynamical fluctuations of these systems may be of Lévy's type rather than Gaussian.
Abstract: We define the class of sporadic dynamical systems as the systems where the algorithmic complexity of Kolmogorov [Kolmogorov, A. N. (1983) Russ. Math. Surv. 38, 29-40] and Chaitin [Chaitin, G. J. (1987) Algorithmic Information Theory (Cambridge Univ. Press, Cambridge, U.K.)] as well as the logarithm of separation of initially nearby trajectories grow as nv0(log n)v1 with 0 < v0 < 1 or v0 = 1 and v1 < 0 as time n → ∞. These systems present a behavior intermediate between the multiperiodic (v0 = 0, v1 = 1) and the chaotic ones (v0 = 1, v1 = 0). We show that intermittent systems of Manneville [Manneville, P. (1980) J. Phys. (Paris) 41, 1235-1243] as well as some countable Markov chains may be sporadic and, furthermore, that the dynamical fluctuations of these systems may be of Levy's type rather than Gaussian.
167 citations
TL;DR: It is suggested that changes in muscle motoneuron pool excitability closely control joint mobilization during slow or static stretching of the human soleus muscle.
Abstract: Change of motoneuron excitability has been studied during the three basic modalities of slow or static stretching of the human soleus muscle. Tendon (T) and Hoffmann (H) reflexes were analyzed during static stretching (SS). The H response was compared in SS, in SS preceded by a maximal isometric contraction of the muscle or contraction-relaxation (CR) and during stretching of the muscle by contracting the antagonistic muscles (AC). During progressive dorsiflexion of the foot there is a significant difference (p less than 0.05) between T and H reflexes during SS, although the amplitude of direct motor (M) response, evoked by a maximal stimulation of the motor nerve, is not changed. The maximal joint mobilization during SS, CR and AC modalities appears to be closely related to the decrease in the H response during stretching. This decrease is significantly (p less than 0.05) smaller in SS than in AC or CR. In this last method, the duration of the maximal isometric contraction does not affect the results. In these three basic stretching procedures, the H reflex quickly recovers as soon as the manoeuvre is interrupted. It is suggested that changes in muscle motoneuron pool excitability closely control joint mobilization during slow or static stretching. The inhibition of the motoneurons observed during SS, CR and AC modalities is limited to the duration of the stretching manoeuvre.
160 citations
TL;DR: Analysis of associations between short amino acid sequence patterns and protein secondary structure classes suggests that secondary structure of proteins can be determined locally by sequence motifs of high predictive value, but at present the ability to find these motifs is limited by the size of the available data bases.
Abstract: Associations between short amino acid sequence patterns and protein secondary structure classes can be found by searching a data base of known protein structures. Analysis of these associations suggests that secondary structure of proteins can be determined locally by sequence motifs of high predictive value, but at present our ability to find these motifs is limited by the size of the available data bases.
TL;DR: In this paper, the galvanostatic anodization of commercially pure titanium is studied with current densities lower than 500 A m −2 in 1 M sulphuric acid between 25 and 75°C.
TL;DR: A pilot study with amphotericin B incorporated in sonicated liposomes (ampholiposomes) made of egg phosphatidylcholine, cholesterol and stearylamine in a molar ratio 4:3:1 was performed in cancer patients with fungal infections, concluding that ampholiposome have a better therapeutic index than Fungizone.
TL;DR: The Loire estuary has been surveyed from 1982 to 1985 by 13 isochronous longitudinal profiles realized at low tide as mentioned in this paper, and the results show that there is a regeneration of dissolved SiO2 and PO43−, a marked NH4+ maximum, while NO3− is conservative or depleted when the HTZ is nearly anoxic.
Abstract: The Loire estuary has been surveyed from 1982 to 1985 by 13 isochronous longitudinal profiles realized at low tide. Nutrient (SiO2, NO3−, NH4+, PO3−4, particulate organic carbon or POC) patterns are very variable depending on the season, the estuarine section [river, upper-inner estuary, upstream of the fresh-water-saline-water interphase FSI, the lower-inner estuary characterized by the high turbidity zone (HTZ), the outer estuary] and the river discharge. Biological processes are dominant. In the eutrophied River Loire (summer pigment > 100 μg l−1), the high algal productivity (algal POC > 3 mg l−1) results in severe depletion of SiO2, PO43−, NO3−. The enormous biomass (55 000 ton algal POC/year) is degraded in the HTZ where bacterial activity is intense. As a result, there is generally a regeneration of dissolved SiO2 and PO43−, a marked NH4+ maximum, while NO3− is conservative or depleted when the HTZ is nearly anoxic. Other processes can be considered including pollution from fertilizer plans (PO43−, NH4+) and from a hydrothermal power plant (NH4+). In the less turbid outer estuary, nutrients are generally conservative. Major variations of concentrations are observed in the lowest chlorinity section (Cl− < 1 g kg−) and also upstream the FSI, defined here as a 100% increase in Cl−. Nutrient inputs to the ocean are not significantly modified for SiO2 and NO2−, but are increased by 70% and 180% for PO43− and NH4+ and depleted by 60% for POC. Odd hydrological events, especially some floods, may perturbate or even mask the usual seasonal pattern observed in profiles.
Journal Article•
TL;DR: A general conclusion from these trials is that studies of the management of infection in GCP should include sufficient numbers of eligible patients to allow for evaluation of bacteremic patients at highest risk of death.
TL;DR: In this paper, a stochastic framework is developed in which an individual'state' is formalized as a distribution on the set of all possible knowledge states, and the question asked and the response observed are used to update the likelihood function.
Abstract: The knowledge state of an individual with respect to a particular body of information is conceptualized as the set of all the questions that this individual is capable of solving. The goal of an assessment procedure is to identify, by a sequence of appropriately chosen questions, the individual's state among all possible ones. A deterministic procedure is conceivable, but not realistic, in that it does not account for possible inconsistencies in the observed responses. Such inconsistencies may arise from careless errors or lucky guesses from the subject, but may also be of a more fundamental character. A stochastic framework is developed here, in which an individual ‘state’ is formalized as a distribution on the set of all possible knowledge states. On each trial, the assessor has a likelihood function on the set of knowledge states which provides the basis for selecting the question to be asked on that trial. The response is assumed to depend on the individual ‘state’. The question asked and the response observed are used to update the likelihood function. Several examples of questioning rules and of updating rules are discussed, which lead to Markov processes. A central problem is to describe conditions ensuring that the latent distribution corresponding to the subject's ‘state’ can be estimated. We show that, under general conditions, the ‘state’ of a subject is uncoverable if the latent distribution is concentrated on a particular knowledge state.
TL;DR: The penetration of several antibiotics into human polymorphonuclear leucocytes was measured with a bioassay and the concentration of vancomycin and teicoplanin associated with the neutrophils appeared to be saturable over the range of extracellular concentrations tested.
Abstract: The penetration of several antibiotics into human polymorphonuclear leucocytes was measured with a bioassay. The aminoglycosides (gentamicin, netilmicin), oxacillin and LY146032, a new lipopeptidic antibiotic, had a penetration which was generally less than 60%, whereas new fluoro-quinolones (enoxacin, ciprofloxacin, CI934, Ro236240) and rifamycins (rifampicin, LM427) were concentrated 2.4 to 14.2-fold. The concentration of vancomycin and teicoplanin associated with the neutrophils appeared to be saturable over the range of extracellular concentrations tested (5-20 mg/l). Coumermycin, an inhibitor of DNA-gyrase, was highly concentrated (11.3 to 16.6-fold) within the neutrophils. The penetration of clindamycin and erythromycin was low (0.60- to 1.48-fold).
TL;DR: Light microscopic immunohistochemical investigations were performed on neurofibrillary tangles in four histologically confirmed cases of Alzheimer's disease and in five patients with a progressive supranuclear palsy, indicating a much more extensive disruption of fibrillar proteins in PSP subcortical neurons than previously reported.
Abstract: Light microscopic immunohistochemical investigations were performed on neurofibrillary tangles (NFT) in four histologically confirmed cases of Alzheimer's disease (AD) and in five patients with a progressive supranuclear palsy (PSP). The antibody panel included antisera to the neuronal microtubule-associated protein, tau, and to isolated paired helical filaments (PHF), as well as mouse monoclonal antibodies (MAbs) to phosphorylated epitopes on high and medium molecular weight neurofilament subunits (RT97 and BF10, respectively). Paraffin sections were also impregnated with the Gallyas silver method, which specifically stains tangles and cortical neuropil threads in AD, but does not stain normal neurofilaments. All tangles in PSP and AD showed consistent immunostaining with antibodies to tau protein and isolated PHF, regardless of their localization. MAbs RT97 and BF10, however, did not stain or only weakly stained, subcortical tangles in PSP and AD, whereas most cortical NFT in AD were intensely immunostained. All tangles in PSP were as heavily impregnated with Gallyas as they were in AD. Furthermore there were extensive networks of Gallyas-positive, tau- and PHF-immunoreactive neurites in subcortical gray areas containing NFT, and bundles of positive axons in white matter tracts interconnecting subcortical nuclei of PSP. Our studies indicate a much more extensive disruption of fibrillar proteins in PSP subcortical neurons than previously reported. They furthermore indicate a very similar antigenic profile of NFT in PSP and AD, as far as subcortical neurons are concerned.
TL;DR: The RNA polymerase transcribing the actin gene exhibited the same sensitivity to inhibition by alpha-amanitin as that transcribing both the spliced leader and the bulk of polyadenylated mRNAs.
Abstract: In Trypanosoma brucei, the actin gene is present in a cluster of two, three, or four tandemly linked copies, depending on the strain. Each cluster seems to exist in two allelic versions, as suggested by the polymorphism of both gene number and restriction fragment length in the DNA from cloned trypanosomes. The amplification of the gene copy number probably occurs through unequal sister chromatid exchange. The chromosomes harboring the actin genes belong to the large size class. The coding sequence was 1,128 nucleotides long and showed 60 to 70% homology to other eucaryotic actin genes. Surprisingly, this homology seemed weaker with Trypanosoma congolense, Trypanosoma cruzi, Trypanosoma vivax, Trypanosoma mega, or Leishmania actin-specific sequences. The mRNA was around 1.6 kilobases long and was synthesized at the same level in bloodstream and procyclic forms of the parasite. Large RNA precursors, up to 7.7 kilobases, were found in a pattern identical in strains containing either two or three gene copies. Probing of the flanking regions of the gene with either steady-state or in vitro transcripts, as well as S1 nuclease protection and primer extension experiments, allowed mapping of the 3' splice site of the actin mRNA, 38 nucleotides upstream from the translation initiation codon. A variably sized poly(dT) tract was found about 30 base pairs ahead of the splice site. The largest detected actin mRNA precursor seemed to give rise to at least two additional stable mRNAs. The RNA polymerase transcribing the actin gene exhibited the same sensitivity to inhibition by alpha-amanitin as that transcribing both the spliced leader and the bulk of polyadenylated mRNAs.
TL;DR: In the folding model proposed for cytochrome b, all mutation sites are not only located on the same side of the membrane but are also in close proximity in the three-dimensional structure.
TL;DR: The data on experimental diabetes in the rat demonstrate that the maternal diabetic environment exerts a diabetogenic influence on the offspring as a consequence of hyperactivity of these B cells during the intrauterine life.
TL;DR: In this article, the topological and correlation dimensions of physiological chaotic attractors are evaluated and the latter are embedded in phase spaces reconstructed using the laging method, multi-channel recordings and the singular value decomposition technique.
TL;DR: In this paper, it was shown that many systems of nonlinear differential equations of interest in various fields are naturally imbedded in a new family of differential equations, and each equation belonging to that family can be brought into a factorized canonical form for which integrable cases can be easily identified and solutions can be found by quadratures.
Journal Article•
TL;DR: In this paper, the transferable belief model (TBM) is defined as a generalization of the Bayesian model or of the upper and lower probabilities model, and its interpretation is discussed.
Abstract: Two models are proposed to quantify someone's degree of belief, based respectively on probability functions, the Bayesian model, and on belief functions, the transferable belief model (Shafer 1976). The first, and by far the oldest, is well established and supported by excellent axiomatic and behaviour arguments. The model based on belief functions is often understood as some kind of generalization either of the Bayesian model or of the upper and lower probabilities model. Therefore we present our interpretation of the model developed initially by Shafer in his book (1977) and called here the transferable belief model. The major point of our interpretation is the fact-we try to dissociate completely the transferable belief model from any model based on probability functions.
01 Jan 1988
TL;DR: The greater European spruce bark beetle, Dendroctonus micans (Kugelann) (Coleoptera: Scolytidae), is the only palaearctic representative of its genus, and its closest relative is the Alaskan D. punctatus LeConte.
Abstract: The greater European spruce bark beetle, Dendroctonus micans (Kugelann) (Coleoptera: Scolytidae), is, with the Chinese species Dendroctonus armandi Tsai and Li, the only palaearctic representative of its genus. It appears to have moved to Eurasia in relatively recent times, and its closest relative is the Alaskan D. punctatus LeConte, the two species being doubtfully distinct.79
TL;DR: In this article, the efficiencies of different anodic reactions observed during the galvanostatic anodization of commercially pure titanium in 1 M sulphuric acid between 25 and 75°C have been studied.
TL;DR: Eight-stranded beta-sheets in nine protein structures containing "TIM (triose phosphate isomerase) barrels" are shown to be fitted satisfactorily by hyperboloids, the generating lines of which pass through the beta-strands.
Abstract: Eight-stranded beta-sheets in nine protein structures containing "TIM (triose phosphate isomerase) barrels" are shown to be fitted satisfactorily by hyperboloids, the generating lines of which pass through the beta-strands. Simple parameterizations of the hyperboloid model are then used to determine the constraints that govern key parameters, such as the number of strands in the barrel, and to rationalize the remarkable conservation of strand number, observed to be eight, in nearly all the known examples of parallel beta-barrels. It is shown that the requirement to exclude solvent from the barrel interior, while at the same time keeping an upper limit on strand twist and interstrand distance so as to foster extensive hydrogen bonding interactions within the sheet, imposes strong constraints on barrel geometry. A formal description of the relationships between beta-sheet twist, strand number, and barrel dimensions is given here. It could have important implications for studies of protein folding and design.
TL;DR: It is indicated that electrostimulation augments the muscle force of contraction by changing peripheral processes associated with intra-cellular events, without modifying the nervous command of the contraction.
Abstract: This paper compares the effects of 6 wk of sub-maximal training by electrostimulation (100 Hz) and voluntary contractions on the contractile properties of the adductor pollicis muscle in intact man. The daily training program consisted of ten series of twenty 1-s isotonic contractions (60 to 65% of maximum) separated by 1-s intervals. The observed increase in muscle force, tested in maximal voluntary and electrically evoked contractions, appears to be significantly smaller during electrostimulation than during a training session performed by voluntary contractions. The increase in force recorded during electrostimulation is not associated with changes in the tetanus rates of tension development and tension relaxation (dP0/dt). Conversely, the tetanus time course is found to be significantly accelerated in muscles trained by voluntary contractions. No change of the surface action potential total area was observed during both training procedures. Furthermore, electrostimulation does not improve muscle resistance to fatigue, which is observed to be significantly increased after training by voluntary contractions. This study indicates that electrostimulation augments the muscle force of contraction by changing peripheral processes associated with intra-cellular events, without modifying the nervous command of the contraction. The comparison of the peripheral changes recorded during sub-maximal training by electrostimulation and voluntary contractions suggests that electrostimulation is less efficient, but complementary to voluntary training because the number and the type of trained motor units are different in the two procedures.
TL;DR: The BRUGEL package as discussed by the authors is a fully integrated molecular modeling package designed for macromolecules and is used for the analysis of protein structure and function and to problems of protein design.
TL;DR: Both genes appear to be coordinately regulated by these inducers, and a well conserved 19-bp segment located just upstream of the TATA box of these genes is also homologous to the minimal region needed for the inducibility by poly(rI).poly(rC) of the interferon-beta gene.
Abstract: The IFI-56K and IFI-54K genes are transcriptionally stimulated when cells are treated by interferon. We have previously shown that the IFI-56K gene is in addition directly induced by poly(rI) · poly(rC), and inducer of interferon-β. Since the regulation of the IFI-56K and IFI-54K genes by interferon are very much alike, we tested whether the IFI-54K gene is also directly regulated by poly(rI) · poly(rC). Treatment of various cell lines with poly(rI) · poly(rC) leads to a clear accumulation of the IFI-54K mRNA to a level which sometimes even exceeds that obtained with high doses of interferon. Several interferon-resistant cell lines were investigated for the inducibility of both the IFI-56K and IFI-54K genes by interferons, poly(rI) · poly(rC) and viruses (which are the natural inducers of interferon-α and -β). Both genes appear to be coordinately regulated by these inducers. It was thus interesting to search for common regulatory element(s) in the control region of these two genes. The IFI-54K gene promoter region was isolated, from which a 520-base-pair segment was sequenced and compared with the promoter region of the IFI-56K gene that we had previously sequenced. The only homology was found is a well conserved 19-bp segment located just upstream of the TATA box of these genes; interestingly, this sequence is also homologous to the minimal region needed for the inducibility by poly(rI) · poly(rC) of the interferon-β gene. This conserved sequence might be responsible for the coordinate induction of the IFI-56K and IFI-54K genes by interferon, poly(rI) · poly(rC) and viruses.