Over-production of exopolysaccharide by Lacticaseibacillus rhamnosus CNCM I-3690 strain cutbacks its beneficial effect on the host.

Most lactobacilli produce extracellular polysaccharides that are considered to contribute to the probiotic effect of many strains. Lacticaseibacillus rhamnosus CNCM I-3690 is an anti-inflammatory strain able to counterbalance gut barrier dysfunction. In this study ten spontaneous variants of CNCM I-3690 with different EPS-production were generated and characterized by their ropy phenotype, the quantification of the secreted EPS and genetic analysis. Amongst them, two were further analysed in vitro and in vivo: an EPS over-producer (7292) and a low-producer derivative of 7292 (7358, with similar EPS levels than the wild type (WT) strain). Our results showed that 7292 does not have anti-inflammatory profile in vitro, and lost the capacity to adhere to the colonic epithelial cells as well as the protective effect on the permeability. Finally, 7292 lost the protective effects of the WT strain in a murine model of gut dysfunction. Notably, strain 7292 was unable to stimulate goblet cell mucus production and colonic IL-10 production, all key features for the beneficial effect of the WT strain. Furthermore, transcriptome analysis of colonic samples from 7292-treated mice showed a down-regulation of anti-inflammatory genes. Altogether, our results point out that the increase of EPS production in CNCM I-3690 impairs its protective effects and highlight the importance of the correct EPS synthesis for the beneficial effects of this strain.

The role of aminopeptidase PepS in the growth of Streptococcus thermophilus is not restricted to nitrogen nutrition.

AIMS: To investigate the effect of an absence of aminopeptidase PepS on the growth of Streptococcus thermophilus on different media and at different temperatures. METHODS AND RESULTS: Using gene interruption, a negative mutant of the Strep. thermophilus CNRZ385 strain was constructed for the aminopeptidase PepS (strain DeltapepS). Checks were first of all made using biochemical assays that the DeltapepS strain lacks the peptide hydrolase activity of aminopeptidase PepS. It was demonstrated that the absence of the aminopeptidase PepS exerted a negative effect on growth whatever the culture medium (M17, chemically defined medium, milk). The role of aminopeptidase PepS in growth was enhanced at a high temperature (45 degrees C vs 37 degrees C). The DeltapepS strain was more resistant to lysozyme than the wild-type strain. CONCLUSIONS: We were able to demonstrate that aminopeptidase PepS probably plays a pleiotropic role through its involvement in growth via nitrogen nutrition, as well as via other cellular functions/metabolisms (such as peptidoglycane metabolism). SIGNIFICANCE AND IMPACT OF THE STUDY: This study constitutes the first report on the role of a member of the M29 MEROPS family of metallopeptidases (http://merops.sanger.ac.uk/).

Heparin does not inhibit oncogene induction in rabbit aorta following balloon denudation.

OBJECTIVE: Smooth muscle cell proliferation and migration are the predominant responses to intimal and medial injury after percutaneous transluminal coronary angioplasty. The in vivo inhibitory effect of heparin on these responses is well documented. To test the hypothesis that the antiproliferative effect of heparin in vivo may be related to an inhibition of proto-oncogene expression, the effects of pretreatment with heparin on the expression of the c-myc, c-fos and c-jun proto-oncogenes were examined in a rabbit model of balloon denudation. METHODS: Animals were randomised 5 h before balloon denudation to receive a subcutaneous injection of unfractionated heparin (7500 IU.kg-1, n = 7) or saline (n = 6). Total RNA extracted from the aorta 1 h after balloon denudation was analysed by northern blot technique. A histological study was also performed in saline treated (n = 4) and heparin treated (n = 4) animals 28 d after balloon denudation. RESULTS: The histological study showed that the degree of neointimal thickening was significantly less in heparin treated animals. However, the level of expression of the proto-oncogenes we studied was similar in both groups. CONCLUSIONS: Heparin inhibits neointimal thickening after balloon denudation. This inhibition is not associated with an overall decrease in the level of expression of the c-myc, c-fos, or c-jun proto-oncogenes in the arterial wall, suggesting that the antiproliferative effect of heparin may be due to an effect on other events in the cell cycle.

SPEM impairment in drug-naive schizophrenic patients: evidence for a trait marker.

Smooth-pursuit eye movements (SPEM) were assessed in healthy subjects and in drug-naive, chronic, and residual schizophrenic patients. SPEM gain was found to be decreased in all the schizophrenic patients who also exhibited a significant increase in the rate of saccades. The frequency of square-wave jerks was the same in schizophrenic patients and normal controls, suggesting that the primary abnormality in schizophrenic patients was a low gain rather than a defect of the saccadic system. Patients were retested 1 month later, and stability of gain was high even in formerly drug-naive subjects who had been treated for 1 month with neuroleptic drugs. Altogether these results confirm the conclusions of most previous studies, extend them to drug-naive schizophrenic patients, and favor the hypothesis that SPEM impairment is a trait marker in schizophrenia.

Normal vestibular responses to air caloric tests in children.

One hundred and forty normal children, divided into four age-groups (2-3, 4-5, 6-7, 8-10 years old) have been submitted to a vestibular examination by caloric tests with air, and the responses were recorded. This technique is sure and easily reproducible. Frequency of nystagmus, and maximum eye speed in slow phase of nystagmus (M.E.S.) were examined during 30 sec after caloric stimulation. Frequency of nystagmus increases, and M.E.S. decreases as the children become older. A significant difference between the 2-3 and 4-5 year old groups is also noticed. Normal variations are fixed for each age group. A quantitative relation between frequency, M.E.S. and height is established.

Vestibular habituation in flightcrew.

Vestibular habituation is a general reaction to any repetitive sensory stimulation. It can be characterized by four main features: acquisition, retention, loss or dishabituation, and transfer. This study concerns three groups of subjects: The first group consists of a) 27 pilots at present serving in the French Air Force, b) 12 pilots at present serving in the major civil airlines, c) 8 navigators, radio-navigators, and crew mechanics, some of whom are flying club pilots, and d) 3 professional pilots trained in flying clubs. All of these subjects had more than 2000 h flying time. They were from 27 to 50 years old. The second group consists of airline stewards. The third group consists of trainee pilots still in flying school. All of these subjects were examined for their suitability, in particular undergoing a damped swing test. The first oscillation was in an anticlockwise direction and the damping extended over 20 periods. The following parametre was measured: the ratio of total left nystagmus frequency to total right nystagmus frequency. In "normal" control subjects the ratio is greater than 1. The results were: The first group: In 41 out of 50 subjects, the ratio of left tremors frequency to right tremors frequency was less than or approximately equal to 1. In the second group: The results showed no significant differences in comparison with a control group of subjects. In the third group: Zero flying time--the results were identical with those of control subjects; 40 h flying time--the ratio approached 1; 100 h flying time--the ratio was less than 1. Vestibular habituation, that is inversion of the preponderance of the total number of left tremors over the total number of right tremors, was observed in the technical flightcrew. The appearance of this inversion during the pilots' training was studied and its retention tested. This test for showing vestibular habituation may be of use for monitoring the function of equilibrium and the development of habituation during flight training. In this report, we shall first review the definition and characteristics of vestibular habituation, and the main body of recent work on this phenomenon in flightcrew. Our own findings will be then presented.

[Systemic form of sarcoid-like necrotizing granulomatosis with ocular, pulmonary and cerebral involvement]. / Forme systémique de granulomatose nécrosante sarcoïdosique avec atteinte oculaire, pulmonaire et cérébrale.

Sarcoid-like necrotizing granulomatosis is an exceptional condition characterized by lesions of epithelioid granulomatosis and signs of vasculitis. It usually involves the lungs and has a favourable prognosis. We report the case of a young woman with a systemic form of the disease which affected not only the lung, but also the eye and the central nervous system. Under corticosteroid therapy the pulmonary lesions and the biological inflammatory syndrome disappeared, but the brain lesions followed a course of their own despite the addition to steroid treatment of an immunosuppressive therapy. This case highlights the superiority of MRI over CT of the brain in the diagnosis and monitoring of brain lesions: CT became normal after corticosteroid therapy was initiated, where as the neurological signs became worse and the brain lesions progressed on MR images.

[Leiomyosarcoma of the superior vena cava. Case report]. / Leiomyosarcome de la veine cave supérieure. A propos d'un cas.

Leiomyosarcoma of the blood vessels is a rare malignant tumor, and its localization in the superior vena cava is exceptional. We had the opportunity to study such a case and we compared our clinical, histological and ultrastructural results with those of 5 other reported cases.

[Pure bronchial adenoma. Anatomico-clinical and ultrastructural study of a case]. / Adénome bronchique pur. Etude anatomoclinique et ultrastructurale d'un cas.

We report a case of monomorphic bronchial cystadenoma (or mucous gland adenoma). This exceptional tumor (only 34 cases reported up to now) is benign, but a lobectomy is often necessary because of severe inflammatory lesions of the surrounding lung. Ultrastructurally it was different from the other tumors of bronchial glands, since it contained mucous cells, myoepithelial cells, and oncocytic cells, and the basement membrane was thickened.

[Purulent meningitis and bacteremia from Bacteroides fragilis revealing a meningioma]. / Méningite purulente et bactériémie à Bacteroïdes fragilis révélatrices d'un méningiome.

We report the case of a 78-year-old-woman with a meningitis caused by Bacteroides fragilis revealing a malignant tumor. The epidemiologic, etiologic and therapeutic features of these meningitis are reviewed.

[Lithium poisoning]. / Intoxication au lithium.

A case of therapeutic overdosage in a 58-year-old woman is reported. Lithium plasma level was 3.7 mmol.l. All clinical and biological disturbances regressed in 3 days after controlled rehydration only. Aetiology, clinical picture, biological characteristics and treatment according to the severity of the lithium poisoning are discussed.

[Lemierre's syndrome]. / Syndrome de Lemierre.

Lemierre's syndrome is a rare disease, mostly affecting young adults in good health, which can lead to significant morbidity and mortality. We report one case with favourable outcome and clinical features stereotypics: angina, septic thrombosis of the internal jugular vein, pulmonary septic metastasis, Fusobacterium necrophorum on blood cultures. Antibiotic therapy targeting anaerobes has been rapidly initiated and maintained 4-6 weeks. The anticoagulation has been maintained 4 weeks.