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Biomedical subjects

A Ben Kheder

Publications and source records attributed to A Ben Kheder.

11 recordsLinked to original sources
PubMed2006

Information-processing under incremental levels of physical loads: comparing racquet to combat sports.

AIM: Skillful performance in combat and racquet sports consists of proficient technique accompanied with efficient information-processing while engaged in moderate to high physical effort. This study examined information processing and decision-making using simple reaction time (SRT) and choice reaction time (CRT) paradigms in athletes of combat sports and racquet ball games while undergoing incrementally increasing physical effort ranging from low to high intensities. METHODS: Forty national level experienced athletics in the sports of tennis, table tennis, fencing, and boxing were selected for this study. Each subject performed both simple (SRT) and four-choice reaction time (4-CRT) tasks at rest, and while pedaling on a cycle ergometer at 20%, 40%, 60%, and 80% of their own maximal aerobic power (Pmax). RESULTS: RM MANCOVA revealed significant sport-type by physical load interaction effect mainly on CRT. Least significant difference (LSD) posthoc contrasts indicated that fencers and tennis players process information faster with incrementally increasing workload, while different patterns were obtained for boxers and table-tennis players. The error rate remained stable for each sport type over all conditions. Between-sport differences in SRT and CRT among the athletes were also noted. CONCLUSIONS: Findings provide evidence that the 4-CRT is a task that more closely corresponds to the original task athletes are familiar with and utilize in their practices and competitions. However, additional tests that mimic the real world experiences of each sport must be developed and used to capture the nature of information processing and response-selection in specific sports.

Adolescent↗
PubMed2006

Simple and choice reaction times under varying levels of physical load in high skilled fencers.

AIM: Fencing requires rapid and accurate decision-making while competing and experiencing gradual perceived effort. This study examined the linkage between physical effort, simple reaction time and choice reaction time in fencers and non-fencer subjects. METHODS: Two age-matched groups participated in this experiment: 12 professional fencers and 12 sedentary subjects. Each subject performed both simple (SRT) and choice reaction time (CRT) tasks at rest, and while pedaling on a cycle ergometer at 20%, 40%, 60%, and 80% of their own maximal aerobic power (Pmax). RESULTS: At rest, no significant differences were found between experts and sedentary subjects neither in SRT nor CRT. The fencers showed shorter CRTs at 40%, 60% and 80% of Pmax compared to those measured at rest. In contrast, SRTs did not vary as a function of effort level. In sedentary subjects, workload did not affect SRTs and CRT. Moreover, the error rate remained stable for each group over all conditions. CONCLUSIONS: Current results showed that physical load results in enhancing information processing as measured by CRT without affecting SRT. The data provides evidence that aerobic exercise enhances attentional capability in fencers who are used to process information under similar physical conditions, but not in sedentary subjects unfamiliar to this environment. Exercise induces arousal that supports alertness to external environmental stimuli in highly trained athletes.

Adult↗
PubMed2005

[Idiopathic pulmonary hemosiderosis in adults].

Idiopathic pulmonary hemosiderosis (IPH) is a rare cause of diffuse alveolar hemorrhage characterized by abnormal deposition of hemosiderin iron in the macrophages of alveoli. Most cases occur in children. In adults, IPH is rare: almost 10 cases reported during the late 10 years. We report the case of a 20-year-old-girl with IPH. There was no evidence of pulmonary vasculitis or capillaritis. Long-term treatment with systemic corticosteroids was followed by clinical remission lasting 4 years.

Adult↗
PubMed2005

Questionnaire on health systems and national resources for control of respiratory health in low-income countries.

BACKGROUND: Due to increased exposure to risk factors such as ageing and tobacco smoking, chronic respiratory diseases (CRDs) have become a major cause of morbidity and mortality worldwide. Data on CRDs and their management in developing countries (DC) are nevertheless sparse and not comparable. OBJECTIVE: To implement and validate a standardised self-administered questionnaire to be proposed to health authorities to assess the resources of their health system for dealing with respiratory diseases. METHODS: The questionnaire concerned social security, description of the health system, human resources available within the system, initial training and continuing education of health personnel, existence of a list of essential drugs, vaccine coverage and specific resources involved in CRD and tobacco control. RESULTS: The validity of the criteria of the questionnaire was tested in Reunion Island, where health data are accessible and reliable, and was found to be satisfactory. Its acceptability and relevance were deemed appropriate in Tunisia and in Mozambique. CONCLUSION: The self-administered questionnaire is a simple, reliable and cheap tool. Although designed for the study of respiratory diseases, it can easily be transposed and adapted to other pathologies.

Chronic Disease↗
PubMed2002

[Endobronchial pulmonary rhabdomyosarcoma. A case report].

We report a case of pleiomorphous pulmonary rhabdomyosarcoma observed in a 64-year-old patient with no history of soft tissue tumor. The tumor was found extending into the right lower and middle lobes. The intra-parenchymatous extension protruded into the middle lobular bronchus and was prolonged by a 4 cm polyp. The polyp extended up to the carina and reached the contralateral common bronchus. Outcome was fatal after surgery performed in an emergency setting due to asphyxia. Explorations could not be continued to determine the primary or secondary nature of the tumor. An intraparenchymatous endobronchial localization is uncommon. Primary rhabdomyosarcoma is generally a purely intra-parenchymatous tumor. The endobronchial localization has been described before but is very exceptional. This localization would also be exceptional for secondary rhabdomyosarcoma mimicking a primary malignant tumor. The histology study revealed an undifferentiated pleiomorphous tumor. Immunohistochemistry provided the final diagnosis.

Bronchial Neoplasms↗