Tuberculosis vaccine candidates based on mycobacterial cell envelope components.

Even after decades searching for a new and more effective vaccine against tuberculosis, the scientific community is still pursuing this goal due to the complexity of its causative agent, Mycobacterium tuberculosis (Mtb). Mtb is a microorganism with a robust variety of survival mechanisms that allow it to remain in the host for years. The structure and nature of the Mtb envelope play a leading role in its resistance and survival. Mtb has a perfect machinery that allows it to modulate the immune response in its favor and to adapt to the host's environmental conditions in order to remain alive until the moment to reactivate its normal growing state. Mtb cell envelope protein, carbohydrate and lipid components have been the subject of interest for developing new vaccines because most of them are responsible for the pathogenicity and virulence of the bacteria. Many indirect evidences, mainly derived from the use of monoclonal antibodies, support the potential protective role of Mtb envelope components. Subunit and DNA vaccines, lipid extracts, liposomes and membrane vesicle formulations are some examples of technologies used, with encouraging results, to evaluate the potential of these antigens in the protective response against Mtb.

Objective measurement of motor speech characteristics in the healthy pediatric population.

OBJECTIVE: To obtain objective measurements of motor speech characteristics in normal children, using a computer-based motor speech software program. METHODS: Cross-sectional, observational design in a university-based ambulatory pediatric otolaryngology clinic. Participants included 112 subjects (54 females and 58 males) aged 4-18 years. Participants with previously diagnosed hearing loss, voice and motor disorders, and children unable to repeat a passage in English were excluded. Voice samples were recorded and analysed using the Motor Speech Profile (MSP) software (KayPENTAX, Lincoln Park, NJ). The MSP produced measures of diadochokinetics, second formant transition, intonation, and syllabic rates. RESULTS: Demographic data, including sex, age, and cigarette smoke exposure were obtained. Normative data for several motor speech characteristics were derived for children ranging from age 4 to 18 years. A number of age-dependent changes were indentified, including an increase in average diadochokinetic rate (p<0.001) and standard syllabic duration (p<0.001) with age. There were no identified differences in motor speech characteristics between males and females across the measured age range. Variations in fundamental frequency (Fo) during speech did not change significantly with age for both males and females. CONCLUSIONS: To our knowledge, this is the first pediatric normative database for the MSP progam. The MSP is suitable for testing children and can be used to study developmental changes in motor speech. The analysis demonstrated that males and females behave similarly and show the same relationship with age for the motor speech characteristics studied. This normative database will provide essential comparative data for future studies exploring alterations in motor speech that may occur with hearing, voice, and motor disorders and to assess the results of targeted therapies.