Microbial growth parameters obtained from the analysis of time to detection data using a novel rearrangement of the Baranyi-Roberts model.

AIMS: To explore the predictions of a novel rearrangement of the Baranyi-Roberts model (BRM) with time to detection data obtained from optical density data of microbial growth. METHODS AND RESULTS: Growth of Escherichia coli and Salmonella Typhimurium under mild conditions of temperature (25-37°C), salt (0·086, 0·51 and 1·03 mol l(-1)) and pH (6·85-4·5) was examined using optical density. Time to detection (TTD) data were fitted to a model based on a rearrangement of the BRM. Observations showed compatibility with standard viable count studies and produced highly accurate specific growth rates and lag phase durations. At high salt and low pH, however, there was a substantial dependency on the initial inoculum for the observation of visible growth. At 30 and 37°C, with 1·03 mol l(-1) salt, and at pH <5·75, no visible growth was recorded for E. coli at initial inoculum levels below 10(7) CFU ml(-1). CONCLUSIONS: The rearranged BRM can be used directly with TTD data obtained from optical density measurements. SIGNIFICANCE AND IMPACT OF THE STUDY: A distinct advantage of the rearranged model is that it allows for a very simple interpretation of easily obtainable data using standard nonlinear regression. The rearranged model gives to TTD data the same modelling capability that the BRM gives to plate count data.

[Assessment of the usefulness of autologous serum skin testing in chronic urticaria: a retrospective single-centre study of 74 patients]. / Evaluation de l'utilité du test au sérum autologue dans l'urticaire chronique idiopathique: étude rétrospective chez 74 patients.

BACKGROUND: Chronic urticaria (CU) is a debilitating disease, and patients and their physicians often seek an aetiological explanation. Studies have suggested that idiopathic CU is associated with the presence of serum auto-antibodies that may be detected by autologous serum skin test (ASST). AIM: To confirm the frequency of positivity of ASST and to evaluate its usefulness and possible correlation with the severity of urticaria (greater resistance to AH1, greater activity score or longer duration). PATIENTS AND METHODS: Patients referred for CU between 1 October 2001 and 31 March 2005 were submitted to standardized explorations including clinical examination, physical tests, CBC, ESR, CRP and anti-thyroperoxidase antibodies, and an ASST was ordered. Inclusion criteria included no discernible cause of CU, acceptance of the protocol, including blood sampling and injection of ASST 3 weeks later, serological tests for HBV, HCV and HIV, and discontinuation of anti-H1 agents and corticosteroids. Exclusion criteria comprised the presence of dermographism, physical urticaria, urticarial vasculitis, and failure to discontinue anti-H1 drugs or corticosteroids. In April 2006, we contacted patients by mail to assess their current treatment, their CU activity score or its resolution. RESULTS: Seventy-four patients (67 women, seven men) of mean age 43 years were included. ASST was positive in 43 patients (58 %) and negative in 31 (42 %). The only noticeable difference, although not statistically significant (p=0.23), was a positive anti-thyroperoxidase antibody result in 12 % of patients with negative ASST versus 24 % of patients with positive ASST. The occurrence of angioedema, the duration of CU, the severity score, the relative inefficiency of AH1 and the use of corticosteroids or cyclosporine were similar between the two groups. DISCUSSION: ASST was positive in more than half of the patients with idiopathic CU both in our study and in the literature, with sensitivity of around 70 % and specificity approaching 80 %. However, while this test can help patients understand their disease better and avoid both a fruitless search for other causes and unnecessary proscription of food allergens, our study shows that positive or negative ASST results have no bearing on treatment and are not associated with greater severity of urticaria or greater resistance to treatment. Consequently, we do not recommend routine use of ASST in patients presenting idiopathic CU.

[Eosinophilic fasciitis associated with Borrelia burgdorferi infection]. / Fasciite à éosinophiles survenue secondairement à une infection par Borrelia burgdorferi.

BACKGROUND: Eosinophilic fasciitis (Shulman syndrome) is defined by the association of sclerodermatous skin changes involving underlying fascia and hypereosinophilia. While the aetiology is unknown, some observations suggest an infectious origin. We report the association of eosinophilic fasciitis with an infection involving Borrelia burgdorferi. PATIENTS AND METHODS: A 54 year-old man consulted for a hardened oedema and stiffness of the calves associated with an oedema of the left hand evolving for 4 months. Routine blood tests showed hypereosinophilia at 1.01 G/l and moderate inflammatory syndrome. Diagnosis of eosinophilic fasciitis was confirmed by MRI and muscle biopsy. Since the patient had reported previous tick bites some months before onset, he was tested for Lyme disease. An ELISA test revealed IgG directed against Borrelia burgdorferi and this was confirmed by Western blot analysis. DISCUSSION: The association of eosinophilic fasciitis with Lyme disease raises the question of a real link or a fortuitous association between the two conditions. Similar cases have been described in the literature with or without isolation of the spirochete from skin or fascia lesions. The incidence of eosinophilic fasciitis remains low compared to the prevalence of the infection in endemic areas. We suggest that in some patients, perhaps genetically predisposed, infection with B. burgdorferi may be at the origin of fasciitis.

[National neonatal screening program for cystic fibrosis: management and organization]. / Le programme national de dépistage néonatal de la mucoviscidose: mise en place et organisation.

France has decided to add to the national neonatal screening program (Phenylketonuria, Hypothyroidism, Congenital Adrenal Hyperplasia, Sickle cell disease) the screening of cystic fibrosis (CF). The screening of CF will be implemented in all regions of France by the end of 2002 and will cover all newborn (near 800,000/year). Based on the recommendation of the French Screening Foundation, the project has been approved by the Health Ministry and will be financed by the social security. CF neonatal screening is now technically feasible and reliable. The proposed methodology includes: immunoreactive trypsin (IRT) dosage on all newborns at day 3 (by radioimmunology "Cis Bio" or immunofluorescence "Delfia") followed by genotype CFTR analysis if IRT level is above 60 micrograms/L. Screening for 29 mutations is planned. If genotype is negative, control of IRT at day 21 will be obtained. Several requirements are included in the program: a protocol of care for the newly diagnosed CF in a specialised CF center; information to all parents of newborns; results of CFTR genotype has to be given during a clinical visit, even if negative. This screening program should allow to screen 98% of the cystic fibrosis patients before the age of 1 month. In order to ensure perfect efficacy, the CF screening program will be evaluated and modified if necessary.

Neonatal screening for cystic fibrosis: France rises to the challenge.

This paper describes the adjustments to the French neonatal screening programme required by the introduction of systematic screening for cystic fibrosis (CF), taking into account both the legal and statutory framework and the lessons of a pilot study carried out 10 years ago. The French association for the screening and prevention of infant handicaps (AFDPHE) has been mandated by its regulatory agencies to organize screening for CF in France (metropolitan and overseas territories). During the year 2001, expert groups (Technical Aspects, Information, Ethics and Genetics, Criteria for CF Centres, Protocol for the Care of a Newborn with CF) issued recommendations for the establishment of a national programme that would guarantee efficiency and adequate patient care from the time of diagnosis onward. The programme is based on a strategy combining immunoreactive trypsin (IRT) assay and the analysis of DNA mutations in dried blood samples obtained at 3 days of age. When an elevated IRT value is found, DNA analysis is performed on the same sample. Owing to the relative regional heterogeneity existing in France, 30 selected mutations are used, which provide 85% coverage. The Ethics and Genetics Committee recommended that, in order to avoid arousing anxiety by a recall, informed consent, according to the French legislation on bioethics, should be obtained for all neonates at birth by having the parents sign directly on the sampling paper. Information brochures for parents and health professionals have been designed. A new organization of patient care, involving the creation of CF centres recognized by the Ministry of Health, has been decided; all children diagnosed are to be referred to such centres, where they can be well cared for by a trained staff with sufficient means. The programme was implemented region by region in France, from the beginning of the year 2002 to early 2003. The expert groups still meet periodically to evaluate the implementation of the programme and to check that the terms of the agreement between the AFDPHE and the Social Security Agency are complied with.