Bifidobacterium longum ATCC 15707 cell production during free- and immobilized-cell cultures in MRS-whey permeate medium

Bifidobacterium longum ATCC 15707 cell production was studied in MRS medium supplemented with whey permeate (MRS-WP) during free-cell batch fermentations and continuous immobilized-cell cultures. Very high populations were measured after 12 h batch cultures in MRS-WP medium controlled at pH 5.5 (1.7+/-0.5x10(10) cfu/ml), approximately 2-fold higher than in non-supplemented MRS. Our study showed that WP is a low-cost source of lactose and other components that can be used to increase bifidobacteria cell production in MRS medium. Continuous fermentation in MRS-WP of B. longum immobilized in gellan gum gel beads produced the highest cell concentrations in the effluent (4.9+/-0.9x10(9) cfu/ml) at a dilution rate (D) of 0.5 h(-1). However, maximal volumetric productivity (6.9+/-0.4x10(9) cfu ml(-1)h(-1)) during continuous cultures was obtained at D =2.0 h(-1), and was approximately 9.5-fold higher than during free-cell batch cultures at an optimal pH of 5.5 (7.2x10(8) cfu ml(-1)h(-1)).

Inflammatory myositis associated with anti-U1-small nuclear ribonucleoprotein antibodies: a subset of myositis associated with a favourable outcome

OBJECTIVES

Inflammatory myositides are rare chronic disorders which may be either isolated or associated with other conditions such as connective tissue diseases or neoplasia. A large variety of autoantibodies can be detected in patients with myositis, some of which have a diagnostic and/or a prognostic value. Myositis associated with anti-U1-small nuclear ribonucleoprotein antibodies (anti-U1-snRNP Abs) are usually considered as overlapping syndromes, mainly mixed connective tissue diseases (MCTD) in which muscle symptoms occur insidiously during the disease course and are characterized by a favourable outcome.

METHODS

The clinical, biological, immunological and pathological findings as well as the outcome of five patients with anti-U1-snRNP-associated myositis were retrospectively analysed.

RESULTS

Patients were mainly black females. In all five patients, myositis was the predominant manifestation at presentation. Associated conditions consisted of interstitial lung disease (ILD) (three), arthritis (three) and neurological symptoms (two). No patient presented Raynaud's phenomenon nor met criteria for MCTD. Biological inflammatory features, rheumatoid factor and polyclonal hypergammaglobulinaemia were present in all cases. Besides anti-U1-snRNP Abs, one patient had anti-Ro/SSA and anti-La/SSB Abs at presentation and one additional patient developed anti-double-stranded-DNA and anti-Sm Abs after a follow-up of more than 4 yr. No patient had anti-PM/sclerosis (Scl) nor anti-aminoacyl-tRNA synthetase Abs. All patients dramatically improved with steroids, and reached complete remission (CR) within 3 weeks. Two patients relapsed 18 months after CR. They both reached rapidly second CR using steroids associated or not with oral methotrexate.

CONCLUSION

Our data suggest that anti-U1-snRNP Abs may define a subset of myositis characterized by a favourable outcome, though often associated with ILD and/or neurological manifestations.

Statistical data validation methods for large cheese plant database

Production data of the cheesemaking process are used to monitor milk fat and protein recoveries in cheese, cheese yield, and composition and eventually to predict these parameters. Due to the large impact of these factors on cheese quality and plant profitability, it is very important to use reliable data for analysis, modeling, and control of the process. This paper tested six methods for detecting erroneous data in industrial cheesemaking databases. The data analyzed came from 4 yr of stirred-curd Cheddar cheese production in an industrial cheesemaking facility, comprising over 10,000 vats. Single vat outliers were detected using a simple statistical criterion of mean +/- 3.6 SD on single variable distributions, Fourier series modeling of seasonal variables (fat, protein, lactose, and total solids in milk, and protein in whey), and the multivariate Mahalanobis outlier analysis. Detection of outlier productions (corresponding to several vats) was done by applying the mean +/- 3.6 SD criterion to variables obtained through calculating the fat mass balance, fat retention coefficient, and yield efficiency. Data treatment enabled the detection of outlier data, but also pinpointed variables with a low reliability (manually registered times). Single variable and multivariable methods proved complementary, and the use of both types of methods is recommended when validating an existing database.

Inhibition of Listeria innocua in cheddar cheese by addition of nisin Z in liposomes or by in situ production in mixed culture

The effect of addition of purified nisin Z in liposomes to cheese milk and of in situ production of nisin Z by Lactococcus lactis subsp. lactis biovar diacetylactis UL719 in the mixed starter on the inhibition of Listeria innocua in cheddar cheese was evaluated during 6 months of ripening. A cheese mixed starter culture containing Lactococcus lactis subsp. lactis biovar diacetylactis UL719 was selected for high-level nisin Z and acid production. Experimental cheddar cheeses were produced on a pilot scale, using the selected starter culture, from milk with added L. innocua (10(5) to 10(6) CFU/ml). Liposomes with purified nisin Z were prepared from proliposome H and added to cheese milk prior to renneting to give a final concentration of 300 IU/g of cheese. The nisin Z-producing strain and nisin Z-containing liposomes did not significantly affect cheese production and gross chemical composition of the cheeses. Immediately after cheese production, 3- and 1.5-log-unit reductions in viable counts of L. innocua were obtained in cheeses with encapsulated nisin and the nisinogenic starter, respectively. After 6 months, cheeses made with encapsulated nisin contained less than 10 CFU of L. innocua per g and 90% of the initial nisin activity, compared with 10(4) CFU/g and only 12% of initial activity in cheeses made with the nisinogenic starter. This study showed that encapsulation of nisin Z in liposomes can provide a powerful tool to improve nisin stability and inhibitory action in the cheese matrix while protecting the cheese starter from the detrimental action of nisin during cheese production.

Quantitative determination of the spatial distribution of pure- and mixed-strain immobilized cells in gel beads by immunofluorescence

A new method was developed to detect and quantify two strains, Lactococcus lactis subsp. lactis biovar. diacetylactis MD and Bifidobacterium longum ATCC 15707, immobilized separately and co-immobilized in gel beads, using specific polyclonal antibodies and confocal laser-scanning microscopy. The establishment of biomass concentration profiles for each strain was measured during colonization of beads using successive pH-controlled batch fermentations. Growth occurred preferentially in 200- and 300-microm peripheral layers of the beads for L. diacetylactis and B. longum, respectively. Repeated-batch cultures with immobilized cells permitted the production of a mixed culture containing a non-competitive strain of bifidobacteria, as a result of immobilized-cell growth and high cell-release activity from the beads. During co-immobilized fermentations, there were no apparent interactions between the strains.

Analysis of underlying diseases and prognosis factors associated with Pneumocystis carinii pneumonia in immunocompromised HIV-negative patients

The aim of this retrospective study was to determine the underlying diseases associated with Pneumocystis carinii pneumonia (PCP) in immunocompromised HIV-negative patients and to identify prognosis factors in this population. One hundred three cases of PCP were diagnosed over a 5-year period. Diagnosis was established on the basis of clinical features and by detection of Pneumocystis carinii cysts in bronchoalveolar lavage fluid. Underlying diseases comprised hematologic malignancies (n=60; 58%), inflammatory diseases (n=27; 26%), and solid tumors (n=18; 17.5%); 9 (8%) patients were solid organ transplant recipients. Seventy-one (69%) patients received cytotoxic drugs, 57 (55%) were treated with long-term corticotherapy, and 15 (14.7%) underwent bone marrow transplantation. Fifty-eight (56%) patients were admitted to the intensive care unit, and 52 (41%) required mechanical ventilation. Thirty-nine (38%) patients died of PCP; data from these patients were compared with those from surviving patients. The following factors were associated with a poor prognosis: high respiratory rate (P=0.005), high pulse rate (P=0.0003), elevated C-reactive protein (P=0.01), elevated serum lactate dehydrogenase level (P=0.02), and mechanical ventilation (OR, 14.4; 95%CI, 5-50). The results suggest that PCP can occur during the course of many immunosuppressive diseases, particularly various hematologic malignancies. The diagnosis of PCP should be considered more frequently and advocated earlier in immunocompromised HIV-negative patients, since prompt diagnosis may improve the prognosis of these patients.

[Methemoglobinemia induced by repeated abuse of lidocaine viscous gel]

Lidocaine use may lead to methemoglobinemia. Lidocaine is clinically widely used as an anaesthesic drug, however its toxic effect is rare. We report a high methemoglobinemia level of 31.1% following repeated Xylocaine gel oral applications. New metabolic pathways of lidocaine have been reported leading to dimethylphenylhydroxylamine in humans. This metabolism is very similar to the aniline derivative ones, and may explain lidocaine methemoglobinemia effect.

Tinea pedis in European marathon runners

BACKGROUND

Epidemiological studies suggest that 15% of the population in industrial countries suffer from tinea pedis (athlete's foot) and that persons who do sports are a high-risk population.

OBJECTIVE

To investigate the responsibility of dermatophytes in interdigital lesions of the feet in European marathon runners and to identify associated risk factors.

SUBJECTS AND METHODS

Runners of the 14th Médoc Marathon (n = 147) were interviewed on risk factors for tinea pedis and underwent physical and mycological examinations.

RESULTS

Interdigital lesions of the feet were found in 66 runners (45%). A dermatophyte was isolated in 45 runners (31%), 12 of whom were asymptomatic. Trichophyton interdigitale and T. rubrum accounted for 49% and 35.5%, respectively, of the cases of tinea pedis. Thirty-three (22%) of the 102 runners free of dermatophyte infection had lesions resembling those of tinea pedis. Increasing age and use of communal bathing facilities were predictive of T. rubrum culture.

CONCLUSIONS

Marathon runners are at high risk for tinea pedis, but dermatophytes are responsible for only half of the foot lesions found in runners. The existence of asymptomatic carriers calls for prophylactic measures.

Smoking cessation counseling practices of general practitioners in Montreal

BACKGROUND

Despite the cost-effectiveness of physician smoking cessation counseling, many physicians do not adhere to current clinical practice guidelines.

METHODS

A cross-sectional mail survey was conducted in a random sample of general practitioners in Montreal to document cessation-counseling practices and identify correlates of these activities.

RESULTS

Of 440 eligible general practitioners, 337 (77%) completed the questionnaire. Despite favorable beliefs/attitudes about cessation counseling, only 10.5% of general practitioners provided "thorough" counseling. While high proportions of general practitioners ascertained smoking status and encouraged patients to quit, relatively few offered adjunct support (i.e., for patients preparing to quit, 49.8% offered follow-up visits; 42.5% offered educational material; 20% referred patients to community resources). Correlates of counseling completeness included high self-efficacy to provide counseling (odds ratio (OR) = 2.0, 95% confidence interval (1.1-3.6)) and favorable beliefs/attitudes about counseling (OR = 3.6 (2.0-6.4)). Correlates of ascertaining smoking status included female gender (OR = 2.3 (1.5-3.5)), high self-efficacy (OR = 3.5 (2.0-5.9)), and favorable beliefs/attitudes (OR = 2.7 (1.6-4.5)). Correlates of offering adjunct support included female gender (OR = 1.9 (1.1-3.2)), awareness of stages of change (OR = 2.4 (1.3-4.4)), and knowledge of community resources to help patients quit (OR = 2.3 (1.3-3.9)).

CONCLUSION

Support, training, and intervention programs to overcome lack of awareness and knowledge, unfavorable beliefs/attitudes, and low self-efficacy could increase and enhance cessation counseling practices among general practitioners.

Effect of inoculum composition and low KCl supplementation on the biological and rheological stability of an immobilized-cell system for mixed mesophilic lactic starter production

Two strains of Lactococcus lactis subsp. lactis (L. lactis KB and KBP) and one of L. lactis subsp. lactis biovar. diacetylactis (L. diacetylactis MD) were immobilized separately in kappa-carrageenan-locust bean gum gel beads. Continuous fermentations were carried out in supplemented whey permeate in a 1-L pH-controlled stirred tank reactor inoculated with a 30% (v/v) bead inoculum and a bead ratio of 55:30:15 for KB, KBP, and MD, respectively. The process demonstrated a high productivity and microbial stability during the 7-week continuous culture. Compared with previous experiments carried out with an inoculum bead ratio of 33:33:33 for KB, KBP, and MD beads, respectively, the modification of the inoculum bead ratio had apparently little effect on free and immobilized, total and specific populations. A dominant behavior of L. diacetylactis MD over the other strains of the mixed culture was observed both with free-cell populations in the effluent and with immobilized-cell populations. Additional experiments were carried out with other strain combinations for continuous inoculation-prefermentation of milk. The data also confirmed the dominance of L. diacetylactis during long-term continuous immobilized-cell fermentations. This dominance may be tentatively explained by the local competition involved in the development of the bead cross-contamination and in citrate utilization by L. diacetylactis strains. The gel beads demonstrated a high rheological stability during the 7-week continuous fermentation even at low KCl supplementation of the broth medium (25 mM KCl).

New method for exopolysaccharide determination in culture broth using stirred ultrafiltration cells

A new method to remove simple carbohydrates from culture broth prior to the quantification of exopolysaccharides (EPS) was developed and validated for the EPS-producing strain, Lactobacillus rhamnosus RW-9595M. This method uses ultrafiltration (UF) in stirred cells followed by polysaccharide detection in the retentate by the phenol-sulfuric acid method. The UF method was compared with a conventional method based on ethanol extraction, dialysis, protein removal by trichloroacetic acid (TCA) and freeze-drying. EPS production during pH-controlled batch fermentations in basal minimum medium, whey permeate (WP). and whey permeate supplemented with yeast extract, minerals and Tween-80 (SWP) was determined by the new UF and conventional methods. EPS recovery by the new method ranged from 83% to 104% for EPS added in the concentration range 40-1,500 mg/l in 0.1 M NaCl solution or culture medium. The UF method was rapid (8 h), accurate and simple, and required only a small sample volume (1-5 ml). A very high maximum EPS production was measured in SWP by both the UF and conventional methods (1,718 and 1,755 mg/l).

Physicians Taking Action Against Smoking: an intervention program to optimize smoking cessation counselling by Montreal general practitioners

In 1997 the Direction de la santé publique de Montréal-Centre initiated "Physicians Taking Action Against Smoking," a 5-year intervention program to improve the smoking cessation counselling practices of general practitioners (GPs) in Montreal. Program development was guided by the precede-proceed model. This model advocates identifying factors influencing the outcome, in this case counselling practices. These factors are then used to determine the program objectives, to develop and tailor program activities and to design the evaluation. Program activities during the first 3 years included cessation counselling workshops and conferences for GPs, publication of articles in professional interest journals, publication of clinical guidelines for smoking cessation counselling and dissemination of educational material for both GPs and smokers. The program also supported activities encouraging smokers to ask their GPs to help them stop smoking. Results from 2 cross-sectional surveys, conducted in 1998 and 2000, of random samples of approximately 300 GPs suggest some improvements over time in several counselling practices, including offering counselling to more patients and discussing setting a quit date. More improvements were observed among female than male GPs in both psychosocial factors related to counselling and specific counselling practices. For example, improvements were noted among female GPs in self-perceived ability to provide effective counselling and in the belief that it is important to schedule specific appointments to help patients quit; in addition, the perceived importance of several barriers to counselling decreased among female GPs. A greater proportion of the female respondents to the 2000 survey offered written educational material than was the case in 1998, and a greater proportion of the male GPs devoted more time to counselling in 2000 than in 1998; however, among male GPs the proportion who discussed the pros and cons of smoking with patients in the pre-contemplation stage declined between 1998 and 2000, as did the proportion who referred patients in the preparation stage to community resources. Our experience suggests that an integrated, theory-based program to improve physicians' counselling practices could be a key component of a comprehensive strategy to reduce tobacco use.

Role of CD23 in astrocytes inflammatory reaction during HIV-1 related encephalitis

Soluble factors released by intra-cerebral activated cells are implicated in neuronal alterations during central nervous system inflammatory diseases. In this study, the role of the CD23 pathway in astrocyte activation and its participation in human immunodeficiency virus-1 (HIV-1)-induced neuropathology were evaluated. In human primary astrocytes, CD23 protein membrane expression was dose-dependently upregulated by gp120. It was also upregulated by gamma-interferon (gamma-IFN) and modulated by interleukin-1-beta (IL-1beta) whereas microglial cells in these stimulation conditions did not express CD23. Cell surface stimulation of CD23 expressed by astrocytes induced production of nitric oxide (NO) and IL-1beta which was inhibited by a specific inducible NO-synthase (iNOS) inhibitor (aminoguanidine), indicating the implication of this receptor in the astrocyte inflammatory reaction. On brain tissues from five out of five patients with HIV-1-related encephalitis, CD23 was expressed by astrocytes and by some microglial cells, whereas it was not detectable on brain tissue from five of five HIV-1-infected patients without central nervous system (CNS) disease or from two of two control subjects. In addition, CD23 antigen was co-localized with iNOS and nitrotyrosine on brain tissue from patients with HIV1-related encephalitis, suggesting that CD23 participates in iNOS activation of astrocytes in vivo. In conclusion, CD23 ligation is an alternative pathway in the induction of inflammatory product synthesis by astrocytes and participates in CNS inflammation.

Relationship between environmental fungal contamination and the incidence of invasive aspergillosis in haematology patients

Invasive aspergillosis (IA) is a major opportunistic infection in haematology patients. Spore inhalation is the usual route of Aspergillus infection, suggesting a determining role of environmental contamination by spores in the epidemiology of IA. We prospectively examined the relationship between environmental contamination by Aspergillus and other fungal species and the incidence of invasive nosocomial aspergillosis (INA) in a bone marrow transplantation unit and two haematology wards. During a four-year period, levels of air and surface fungal contamination were determined bi-monthly in patients' rooms (some equipped with HEPA filters and LAF systems), and various common sites in each ward (corridors, nursing stations, etc.). Results were compared to the incidence of INA. A total of 3100 air and 9800 surface samples were collected, and 79 cases of IA were diagnosed, of which 64 were probably or possibly INA. Patterns of fungal contamination were comparable in the three wards, with a gradient ranging from high levels in common sites to a virtual absence in rooms equipped with HEPA filters and LAF systems. Using a regression model, a significant relationship was found between the incidence of INA and the degree of fungal contamination of air and surfaces in conventional patient rooms (not equipped with HEPA) and common sites. This study shows that in a non-epidemic setting, there is a significant relationship between environmental fungal contamination in haematology wards and the incidence of INA. Our findings underline the importance of environmental surveillance and strict application of preventive measures.

Production and characterization of anti-nisin Z monoclonal antibodies: suitability for distinguishing active from inactive forms through a competitive enzyme immunoassay

As a pre-requisite to monoclonal antibody development, an efficient purification strategy was devised that yielded 72 mg of nisin Z from 14.5 1 of Lactococcus lactis subsp. lactis biovar. diacetylactis UL 719 (L. diacetylactis UL719) culture in supplemented whey permeate. Specific monoclonal antibodies (mAbs) were produced in mice against the purified nisin Z using keyhole limpet hemocyanin as a carrier protein. These antibodies did not recognize nisin A, suggesting that the asparagine residue at position 27 is involved in antibody recognition to nisin Z. However, the high reactivity of mAbs against biologically inactive nisin Z degradation products, produced during storage of freeze-dried pure nisin Z at -70 degrees C, indicated that the dehydroalanine residue at position 5 (Dha5), required for biological activity, is not necessary in nisin Z recognition by the mAb. A competitive enzyme immunoassay (cEIA) using the specific anti-nisin Z mAb was developed and used for rapid and sensitive detection and quantification of nisin Z in fresh culture supernatant, milk and whey. Detection limits of 78 ng/ml in phosphate-buffered saline, 87 ng/ml in culture supernatant, 106 ng/ml in milk and 90.5 ng/ml in whey were obtained for this assay. The cEIA using specific mAbs can be used to quantify nisin Z in food products.

Direct muscle neurotization after end-to-side neurorrhaphy

Over the recent years, end-to-side neurorrhaphy has reemerged in the literature for reconstructive nerve surgery. Another technique, in which interest has remained continuous during the last century, is direct nerve implantation into muscle belly, so-called direct muscle neurotization (DMN). In this work, the authors present a new technique to recover muscle innervation through direct nerve implantation into muscle belly, by means of a nerve graft, and sutured with end-to-side neurorrhaphy. They carried out experiments on 20 Wistar rats divided into two groups. In Group 1 (10 rats), on the right side, the peroneal nerve was sutured to the tibial nerve with end-to-side neurorrhaphy. Subsequently, the terminal branches of the same nerve were implanted in the anterior tibial muscle (ATM). On the left side, the peroneal nerve was severed, and the ATM completely denervated. In Group 2 (10 rats), on the right side, the same technique was used as in first group. On the left side, the normal innervation of the ATM was maintained. After 4 months, all muscles and nerves were harvested and evaluations carried out on the morphologic aspect, weight, and histology of the ATM, as well as the histology of the nerves. The authors analyzed the results, which demonstrated good reinnervation of the muscles deprived of any nerve connection.

Comparison of the activity spectra against pathogens of bacterial strains producing a mutacin or a lantibiotic

The increase of drug resistance among bacterial pathogens is currently a major threat in hospital settings. New and more efficient antibiotic compounds have to be developed to fight infectious diseases. In the present work, a deferred antagonism test was used to determine the activity of different bacterial strains producing either a mutacin or a lantibiotic against bacterial pathogens. The mutacins A, B, C, D, I, K, L, M, and nisins A and Z were active against all enterococci tested. Mutacins A and B, and nisins A and Z inhibited all the staphylococci tested. Except for the strains producing mutacins P, Q, and X, all the other producing strains inhibited the streptococci tested. Mutacins A, B, I, J, T, nisins A and Z, and epidermin inhibited the two antibiotic-resistant strains of Neisseria gonorrhoeae tested. Mutacins A, B, C, D, and nisins A and Z inhibited Campylobacter jejuni and Helicobacter pylori. Thus, the wide activity spectra of nisin A and Z are confirmed. These results also indicate that many of the mutacins, especially those of groups A, B, C, D, I, J, K, L, M, and T, could be candidates for further development as useful antibiotics.

[Epidemiology of tinea capitis]

PREDOMINANT IN CHILDREN: Tinea capitis is the most frequent fungal infection in children under the age of puberty. It occurs only rarely in men but is observed in adult women. Human-to-human, animal-to-human and soil-to-human transmission can be involved.

HISTORICAL BACKGROUND

The spectrum of fungal species known to cause tinea capitis has steadily grown for more than a century, varying with the local urban or rural environment. Since the beginning of the 20th century and up to the advent of griseofulvin in the sixties, M. audouinii, an anthropophilic species, caused major epidemics in France, England and the USA. In the sixties to eighties, M. canis was the cause of most cases observed throughout the world. Over the last 20 years, anthropophilic species have again become the leading cause of tinea capitis epidemics, particularly in large cities, in relationship with immigration: T. tonsuransi in the USA and England and T. soudanense and M. langeronii in France.

HYGIENE AND EDUCATION

Despite the benign curable nature of the disease, interhuman transmission of tinea capitis is nevertheless a considerable public health problem due to the increasing number of children affected and the risk of contagion in schools. The considerations resulting from recent studies point out the fact that transmission occurs more often in the family than the school setting, particularly indirectly by common use of grooming instruments. This would explain the high percentage of tinea capitis in large immigrant families where hair combing habits favor transmission. In France, these observations should lead to a revision of the current regulations concerning expulsion from school of children affected by tinea capitis. Better education would be a more appropriate response to the problem.