Cerebrospinal fluid findings in adults with acute Lyme neuroborreliosis

Presence of BB-specific antibodies in the cerebrospinal fluid (CSF) with evidence of their intrathecal production in conjunction with the white cell count in the CSF and typical clinical symptoms is the traditional diagnostic gold standard of Lyme neuroborreliosis (LNB). Few data are available on the CSF lactate concentration in European adults with the diagnosis of acute LNB. The objective of the study was to investigate the CSF changes during acute LNB. Routine CSF parameters [leukocyte count, protein, lactate and albumin concentrations, CSF/serum quotients of albumin (QAlb), IgG, IgA and IgM, and oligoclonal IgG bands] and the Borrelia burgdorferi (BB)-specific antibody index were retrospectively studied in relation to the clinical presentation in patients diagnosed with acute LNB. A total of 118 patients with LNB were categorized into the following groups according to their symptoms at presentation; group 1: polyradiculoneuritis (Bannwarth’s syndrome), group 2: isolated facial palsy and group 3: predominantly meningitic course of the disease. In addition to the CSF of patients with acute LNB, CSF of 19 patients with viral meningitis (VM) and 3 with neurolues (NL) were analyzed. There were 97 patients classified with definite LNB, and 21 as probable LNB. Neck stiffness and fever were reported by 15.3% of patients. Most of these patients were younger than 50 years. Polyradiculoneuritis was frequently found in patients older than 50 years. Lymphopleocytosis was found in all patients. Only 5 patients had a CSF lactate ≥3.5 mmol/l, and the mean CSF lactate level was not elevated (2.1 ± 0.6 mmol/l). The patients with definite LNB had significantly higher lactate levels than patients with probable LNB. Elevated lactate levels were accompanied by fever and headache. In the Reiber nomograms, intrathecal immunoglobulin synthesis was found for IgM in 70.2% followed by IgG in 19.5%. Isoelectric focussing detected an intrathecal IgG synthesis in 83 patients (70.3%). Elevated BB AIs in the CSF were found in 97 patients (82.2%). Patients with VM showed lower CSF protein concentration and CSF/serum quotients of albumin than LNB patients. In acute LNB, all patients had elevated cerebrospinal fluid (CSF) leukocyte counts. In contrast to infections by other bacteria, CSF lactate was lower than 3.5 mmol/l in all but 5 patients. The CSF findings did not differ between polyradiculoneuritis, facial palsy, and meningitis. The CSF in LNB patients strongly differed from CSF in VM patients with respect to protein concentration and the CSF/serum albumin quotient

Efficient Fail-Stop Signatures from the Factoring Assumption

Abstract. In this paper, we revisit the construction of fail-stop signatures from the factoring assumption. These signatures were originally proposed to provide information-theoretic-based security against forgeries. In contrast to classical signature schemes, in which signers are protected through a computational conjecture, fail-stop signature schemes protect the signers in an information theoretic sense, i.e., they guarantee that no one, regardless of its computational power, is able to forge a signature that cannot be detected and proven to be a forgery. Such a feature inherently introduced another threat: malicious signers who want to deny a legitimate signature. Many construction of fail-stop signatures were proposed in the literature, based on the discrete logarithm, the RSA, or the factoring assumptions. Several variants of this latter assumption were used to construct fail-sop signature schemes. Bleumer et al. (EuroCrypt ’90) proposed a fail-stop signature scheme based on the difficulty of factoring large integers and Susilo et al. (The Computer Journal, 2000) showed how to construct a fail-stop signature scheme from the so-called “strong factorization ” assumption. A later attempt by Schmidt-Samoa (ICICS ’04) was to propose a fail-stop signature scheme from the p 2 q factoring assumption. Compared to those proposals, we take a more traditional approach by considering the Rabin function as our starting point. We generalize this function to a new bundling homomorphism while retaining Rabin’s efficient reduction to factoring the modulus of the multiplicative group. Moreover, we preserve the efficiency of the Rabin function as our scheme only requires two, very optimized, modular exponentiations for key generation and verification. This improves on older constructions from factoring assumptions which required either two unoptimized or four exponentiations for key generation and either two unoptimized or three modular exponentiations for verifying. Key words: Fail-stop signature schemes, Digital signatures, Rabin function, Factorin