Biologically-variable rhythmic auditory cues are superior to isochronous cues in fostering natural gait variability in Parkinson's disease.

INTRODUCTION: Rhythmic auditory cueing improves certain gait symptoms of Parkinson's disease (PD). Cues are typically stimuli or beats with a fixed inter-beat interval. We show that isochronous cueing has an unwanted side-effect in that it exacerbates one of the motor symptoms characteristic of advanced PD. Whereas the parameters of the stride cycle of healthy walkers and early patients possess a persistent correlation in time, or long-range correlation (LRC), isochronous cueing renders stride-to-stride variability random. Random stride cycle variability is also associated with reduced gait stability and lack of flexibility. METHOD: To investigate how to prevent patients from acquiring a random stride cycle pattern, we tested rhythmic cueing which mimics the properties of variability found in healthy gait (biological variability). PD patients (n=19) and age-matched healthy participants (n=19) walked with three rhythmic cueing stimuli: isochronous, with random variability, and with biological variability (LRC). Synchronization was not instructed. RESULTS: The persistent correlation in gait was preserved only with stimuli with biological variability, equally for patients and controls (p's<0.05). In contrast, cueing with isochronous or randomly varying inter-stimulus/beat intervals removed the LRC in the stride cycle. Notably, the individual's tendency to synchronize steps with beats determined the amount of negative effects of isochronous and random cues (p's<0.05) but not the positive effect of biological variability. CONCLUSION: Stimulus variability and patients' propensity to synchronize play a critical role in fostering healthier gait dynamics during cueing. The beneficial effects of biological variability provide useful guidelines for improving existing cueing treatments.

Use of polymerase chain reaction for improved diagnosis of tuberculosis in children.

OBJECTIVE: To study the value of a rapid diagnostic method based on the amplification by polymerase chain reaction (PCR) of a fragment of the IS6110 insertion element for the detection of Mycobacterium tuberculosis in children. DESIGN: We tested 199 specimens obtained from 68 children referred for evaluation of suspected tuberculosis. RESULTS: In 83.3% of children with active disease and 38.9% with tuberculous infection but no evidence of disease, at least one positive PCR result was observed. No child without tuberculosis had positive PCR results (100% specificity). The sensitivity of the PCR was increased by testing of multiple samples from the same child and use of Chelex particles (Bio-Rad Laboratories, Ivry, France) rather than guanidine isothiocyanate-silica particles for DNA extraction. Bronchoalveolar lavage samples were no more useful than gastric aspirates. CONCLUSIONS: If appropriate laboratory methods are used, DNA amplification is a reliable method for the early diagnosis of tuberculosis in children and appears to be very helpful in clinical pediatric practice when the diagnosis of active tuberculosis is difficult or needs to be rapidly confirmed.

Diagnosis of tuberculosis by DNA amplification in clinical practice evaluation.

Various polymerase chain reaction (PCR) assays have been devised for the rapid identification of mycobacteria in clinical specimens. To assess the value of such assays in routine laboratory work the results obtained by PCR were compared with those obtained by standard microbiological methods for 514 specimens collected for investigation of mycobacterial infection. Specimens were tested for the presence of Mycobacterium tuberculosis complex and atypical mycobacteria in two assays, one based on amplification of the 65 kDa gene and the other on the IS6110 insertion sequence. For the 489 samples that did not contain inhibitors of the amplification reaction PCR findings correlated well with bacteriological and/or clinical data in 476 (97.4%). 6 PCR results turned out to be false negatives, 3 to be false positives and 4 to be mis-identification of strains. Pre-treatment of samples with guanidium thiocyanate reduced the proportion of false-negative results and of samples that contained inhibitors. This study confirms the potential of DNA amplification for early diagnosis of mycobacterial infections.

[Analysis of 190 strains of Neisseria gonorrhoeae isolated in Yaounde from 1984 to 1987: auxotypes, plasmidic contents, antibiotic sensitivity]. / Analyse de 190 souches de Neisseria gonorrhoeae isolées à Yaoundé de 1984 à 1987: auxotypes, contenus plasmidiques, sensibilité aux antibiotiques.

Gonococcal infections are always a public health problem in Cameroon. From January 1984 to December 1987, 2,074 strains have been isolated in the "Centre Pasteur du Cameroun". Among these strains, 190 had been studied in details concerning antibiotic susceptibility, auxotypes and plasmidic content. Penicillinase producing Neisseria gonorrhoeae (PPNG) were increasingly isolated: 32.28% (1984); 59.57% (1987). Auxotypes prototrophes and proline requiring were more often isolated. Plasmidic content showed essentially african type (with or without conjugative plasmid) but also asian type.

[The combined measles-yellow fever vaccination in African infants aged 6 to 10 months]. / Etude de la vaccination combinée rougeole-fièvre jaune chez l'enfant African âgé de 6 à 10 mois.

The compared tolerance and immunogenicity of vaccines against yellow fever and measles, separately administered or combined, have been evaluated in a group of 319 children from North Cameroon, aged 6-10 months. The clinical tolerance was excellent for both the isolated and the combined vaccines. The seroconversion level is higher after administration of the combined vaccine: 89.9% against 83.5% for measles, 95.8% against 92.6% for yellow fever, but these results are not significantly different. 30 days after vaccination, the antibody titers are higher with the combined vaccine: 215.3 against 156.5 for measles (non significant difference), 34 against 22.6 for yellow fever (highly significant difference). Whatever the vaccination method is, the antibody levels are protecting. It becomes then possible to include the combined vaccination against yellow fever and measles in the EPI of yellow fever endemic countries.

[Surveillance of Plasmodium falciparum drug sensitivity in Yaounde and its surroundings (Cameroon). In vivo and in vitro study]. / Surveillance de la chimiosensibilité de Plasmodium falciparum à Yaoundé et ses environs (Cameroun). Etude in vivo, in vitro.

Among 172 strains collected in Yaoundé 60% are chloroquine-resistant, 37% are amodiaquine-resistant, instead of quinine and mefloquine which are completely efficient. Among 30 strains collected at a rural health center (where self treatment decreases), 27% are chloroquine-resistant. New therapeutic schemes for first and second line treatment in endemic areas must be evaluated.

Chlamydia ophthalmia neonatorum in Cameroon.

In the Ndoungué Hospital in Cameroon 449 new-born babies were examined for a month to check on the occurrence of ophthalmia neonatorum. Silver nitrate eyedrops 1% were applied at birth. The incidence of ophthalmia neonatorum was 19.4%; Chlamydia was found in 8 cases (incidence 1.8%) and gonococci in 4 cases (0.9%). Chemical conjunctivitis was suspected in 13 cases (2.9%). Slight conjunctivitis was seen in 68 cases and severe conjunctivitis in 19 cases (4.2%). A sexually transmitted agent was demonstrated in 6% of the slight cases and in 42% of the severe cases. Ophthalmia neonatorum due to Chlamydia was significantly more frequently severe and without specific features than those due to other agents. Although silver nitrate is still considered to be one of the most effective prophylactic measures for gonococcal ophthalmia neonatorum, in 4 cases this disease still developed. Silver nitrate is ineffective against Chlamydia and is also often the cause of a chemical conjunctivitis. The search is advocated for more efficient medicines in Africa which are effective against both Chlamydia and resistant gonoccoci.

[Prevalence of carriers of antibodies against human immunodeficiency virus (HIV-1 and HIV-2) in South Cameroon. Results of attempts to isolate retroviruses]. / Prévalence des porteurs d'anticorps contre les virus de l'immunodéficience humaine (VIH1 et VIH2) dans le Sud-Cameroun. Résultats des tentatives d'isolement de rétrovirus.

In this work are summarized the results of the serological investigations about HIV1 and HIV2 done since 1986 in the Republic of Cameroon, using the Henderson's cluster sampling method (2). With regard to neighbour countries' results, the prevalence of specific antibodies against HIV1 is weak (less than or equal to 0.5%). This is confirmed by the few number of AIDS (53) since 1985. The prevalence of the HIV2 antibodies carriers is null. Since 1987, the Centre Pasteur of Cameroon is able to isolate retrovirus. The lymphocyte cultures from false positive samples were always negatives.

[Burkitt's lymphoma in Cameroon. Anatomo-clinical and epidemiologic considerations of 66 cases seen from 1980 to 1986]. / Le lymphome de Burkitt au Cameroun. Considérations anatomo-cliniques et épidémiologiques sur 66 cas recensés de 1980 à 1986.

An epidemiological study of 66 cases of Burkitt's lymphoma, a census taken between 1980 and 1986 permitted us to ascertain that, in Cameroon, this disease does not only affect children under the age of 15 years, and that the distribution is almost the same in both sexes. Geographically, the littoral and the western region are more affected than the rest of the country. Clinically although the maxillo-facial localisations are not negligible (29.6%), the abdomen involvement is more common (50%; particularly ovary in women). The clinical aspects met are fairly often advanced or generalized cases.

[Chlamydia trachomatis: a prevalence study among pregnant and infertile female patients and among men suffering from chronic urethritis]. / Chlamydia trachomatis: etude de la prevalence chez la femme enceinte, la femme infeconde, et l'homme souffrant d'une uretrite chronique.

PIP: In recent years, Chlamydia trachomatis infections have been found to be among the major causes of salpingitis throughout the world. In order to determine in the 1st trimester of pregnancy the prevalence of this infection in a previously unscreened population by direct immunofluorescence (Microtrak), we examined 3 groups: women (n=58), infertile women (n=87) and males with subacute urethritis (n=24). Infertility was defined as incapacity to achieve a pregnancy after 12 months of unprotected coitus; subacute urethritis patients had been treated previously for an acute disease and later presented with persistent urethral complaints. The overall prevalence of Chlamydia in all 3 population groups was 13.0% among 169 patients. This rate was divided as follows: pregnant women--8.6%; infertile women--11.5%; men with subacute urethritis--29.2%. Compared to the pregnant group, the infertile and subacute urethritis groups had a significantly high risk of harboring a chlamydial infection. In all female patients, the risk of chlamydial infection decreased with increasing parity, suggesting an association between chlamydial infection and infertility. (author's)^ieng

[Antibiotic resistance of strains of Vibrio cholerae eltor isolated in Douala (Cameroon)]. / Résistance aux antibiotiques des souches de Vibrio cholerae eltor isolées à Douala (Cameroun).

Endemic cholera has been prevalent in Douala since 1972, with sudden epidemic outbreaks occurring every two years during the dry season. The massive and systematic use of chemoprophylaxis since April, 1983 has led to the selection of strains of Vibrio cholerae eltor that are resistant to sulphamide and tetracycline. During the 1984-1985 epidemic, 89.3% of the isolated strains were resistant to sulphamides, 87.5% to a sulfamethoxazole-trimethoprim combination and to the 0/129 disk, 55.3% to tetracycline, 91.1% to chloramphenicol, 73.2% to streptomycin and 94.6% to ampicillin. The epidemic aspect of this multiple resistance to antibiotics raises the issue of the role of a group C incompatibility resistance plasmid. As regards prophylaxis, until hygiene conditions can be improved, which is the only way cholera can be eradicated from our region, vaccination with oral vaccines such as that of the Institut Pasteur seems to be the best way of preventing further epidemics.

[Prevalence of markers of viral hepatitis B in northern Cameroon]. / Prévalence des marqueurs de l'hépatite à virus B dans le nord du Cameroun.

The authors report the results of a sample survey made in January 1985 in a Northern Cameroon Division following the observation of a very high mortality rate by serious jaundice in 1983 and 1984. Within a representative population sample of 395 persons of more than 4 years old, they observed that: 100 were HBs antigen carriers (detected by ELISA), 25.3% +/- 5.5%, 19 were HBe antigen carriers (RIA), 4.8% +/- 2.4%, and 202 were HBs antigen or HBs antibody carriers: 51.1% +/- 6.5%, There was only one carrier of delta antigen. There is no difference in HBs antigen bearing according to sex or age, but HBe antigen appears to be more frequent among young people.

[In vitro virucidal activity of antiseptics and disinfectants. I. Draft of the AFNOR virucidal activity standard]. / Activité virucide in vitro des antiseptiques et désinfectants. I. Projet de la norme "activité virucide" de l'AFNOR.

An antiseptic (ATS) or disinfectant (DSF) is defined as virucidal if it produces a 10 000-fold (4 log) or greater reduction in the number of infective units (IU) of three viral species (Sabin type I poliovirus, type 5 adenovirus, and vaccinia virus) and three E. coli bacteriophages (MS2, T2 and phi X174). and three E. coli bacteriophages (MS2, T2 and phi X174). Preliminary trials produce viral suspensions at concentrations of 10(6) to 10(9) IU/ml, and determine the subtoxic dilution "d" of the tested agent, susceptibility of treated cells to the viral infection, and antiviral activity termination dilution "D". Actual trials may be performed with one of three methods: simple dilution, dilution-ultrafiltration-reconcentration, or gel column filtration. With these techniques, virucidal activity can be determined after a set time of contact (15 to 60 mn) at a given temperature (21 degrees C or 37 degrees C) by titrating the viral suspension after elimination or neutralization of the ATS or DSF.

[Multicenter study of the antimicrobial activity of antiseptics on the hands. Protocols and results]. / Etude multicentrique de l'activité antimicrobienne des antiseptiques sur les mains. Protocoles et résultats.

Quantitative evaluation of in vivo activity of antiseptics in surgical-type handwashing is achieved by comparing bacterial counts on one hand after disinfection and on the other untreated hand. Handwashing, bacterial recovery and bacterial counts must be performed according to strictly standardized methods. A large number of participants is required.

[In vitro virucidal activity of antiseptics and disinfectants. II. Simple dilution technic]. / Activité virucide in vitro des antiseptiques et désinfectants. II. Technique par dilution simple.

The simple dilution technique is based on termination of the tested agent's antiviral activity by sudden cold dilution (D). It can be used only if D less than or equal to 10(3) but is the most simple method. We used this technique to study ATS and demonstrate the strong virucidal activity of glutaraldehyde, inefficiency of chlorhexidine digluconate and questionable activity of povidone-iodine and noxythiolin.

[In vitro virucidal activity of antiseptics and disinfectants. III. Dilution-ultrafiltration-reconcentration technic]. / Activité virucide in vitro des antiseptiques et désinfectants. III. Technique par dilution-ultrafiltration-reconcentration.

The method for in vitro investigation of virucidal activity of antiseptics (ATS) of disinfectants (DSF) using dilution-ultrafiltration-reconcentration includes two phases following contact of the virus with ATS or DSF: termination of antiviral activity by sudden cold dilution, and one or more filtrations on an immersible molecule separator designed to bring the tested agent's concentration below the cytotoxic level and to reconcentrate the treated viral suspension. Advantages of this technique are the following: precision of time of contact between virus and ATS or DSF, reconcentration of the viral suspension which partly offsets the termination dilution, relative simplicity, and study of true virucidal activity. Drawbacks are: inappropriateness for some agents such as povidone-iodine, and, in some instances, unreliability of immersible separators. Apart for those obtained with povidone-iodine, results are comparable to those yielded by simple dilution or gel filtration, particularly for glutaraldehyde, chlorhexidine and noxythiolin.