The relative contributions of anthropometric variables to vertical jumping ability and leg power in Tunisian children.

The purpose of this study was to examine the relative contributions of anthropometric variables to vertical jumping ability and leg power and to establish reference values of vertical jumping parameters in athletic Tunisian children aged 7-13 years in both sexes. Three hundred and ninety-one athletic Tunisian children (208 boys and 183 girls) aged 7-13 years were randomly selected to participate in our study. They were asked to perform squat jumps and countermovement jumps.

[Determining factors of pulmonary function in healthy Tunisian children].

Introduction Pulmonary function parameters are known to vary with age, sex, height and ethnic extraction. No normal values have been reported for pulmonary function in Tunisian children. Moreover, little attention has been paid to the factors affecting the development of lung function in Tunisian healthy children.

Factors affecting the development of lung function in Tunisian children.

We undertook to evaluate the impacts of morphology at birth, physical activity, anthropometric, socioeconomic and environmental factors on lung function in healthy Tunisian children. Pulmonary function parameters were measured with a Minato portable spirometer in a randomized population of 756 healthy children (388 males and 368 females) aged between 6 and 16. The morphology at birth, the gestational age, the physical activity, the socioeconomic status, the type of habitation, and the environmental factors were all assessed by a standard questionnaire.

Spirometric values in Tunisian children: relationship with pubertal status.

Background: Little is known about the effect of pubertal stages on lung function parameters in Tunisian children.

Aim: The purpose of this study is to determine the relationship between lung function and pubertal stage in Tunisian children using anthropometric parameters.

Subjects And Methods: Pulmonary function parameters were measured with a Minato portable spirometer in 684 healthy Tunisian children (351 males and 333 females) aged between 8 and 16.

Carvedilol inhibits right ventricular hypertrophy induced by chronic hypobaric hypoxia.

Right ventricular hypertrophy induced by chronic hypoxia is mainly due to a mechanical stress upon the ventricular wall secondary to pulmonary arterial hypertension. However, the hypoxic chronic activation of the sympathetic nervous system can contribute to the development of right ventricular hypertrophy either via myocardial adrenergic receptors and/or a vasoconstriction and remodeling of pulmonary arteries. To highlight the specific role of the sympathetic nervous system on hypoxia-induced right ventricular hypertrophy and particularly the efficiency of carvedilol, our study compared physiological, myocardial, and pulmonary arterial morphometric data in rats treated by alpha-(prazosin), or beta-(propranolol) or alphabeta-(carvedilol) antagonist and exposed to chronic hypobaric hypoxia (2 weeks at 380 mmHg barometric pressure).

Time course of ventilatory acclimatisation to hypoxia in a model of anemic transgenic mice.

We questioned the assumption that polycythemia is essential for adaptation to chronic hypoxia. Thus, the objective of our study was to determine if anemic Epo-TAg(h) mice could survive in hypoxia despite low oxygen carrying capacity. We explored the possibility that ventilatory acclimatisation is involved in the strategy used by anemic transgenic mice to adapt to chronic hypoxia.

Characterisation of the ventilatory response to hypoxia in a model of transgenic anemic mice.

Both polycythemia and the increase in hypoxic ventilatory response (HVR) are considered as important factors of acclimatization to hypoxia. The objective of this study was to characterise the ventilation pattern at different inspired oxygen fraction in a model of chronic anemic mice. These mice have a targeted disruption in the 5' untranslated region of the Epo gene that reduces Epo expression such that the homozygous animal is severely anemic.

Effects of nifedipine-induced pulmonary vasodilatation on cardiac receptors and protein kinase C isoforms in the chronically hypoxic rat.

In chronic hypoxia, pulmonary hypertension induces a right ventricular (RV) hypertrophy (RVH) and the catecholamine-activated adrenergic system modulates cardiovascular responses through alpha- and beta-adrenergic pathways. The alpha(1)-adrenergic receptor (alpha(1)-AR) and protein kinase C (PKC) may play an important role in the signaling pathway leading to RVH. The aim of this study was to examine the relationship between nifedipine-induced pulmonary vasodilatation, the blunting of RVH and the modifications in the density of alpha(1)-AR, PKC activity and expression of PKC isoforms.

Calcitonin gene-related peptide-immunoreactive nerves and neuroendocrine cells after lung transplantation in the rat.

Bronchial innervation is interrupted at lung transplantation. Nerve fibers with cell bodies above the section, such as sensory C fibers, should degenerate. Using histofluorescence, we evaluated calcitonin gene-related peptide (CGRP) immunoreactivity in syngeneic Lewis rats 1 and 5 mo after unilateral lung transplantation and in controls.

Phenotypic and quantitative changes in mast cells after syngeneic unilateral lung transplantation in the rat.

1. Lung transplantation causes a total interruption of the inneration and vascularization within the transplanted organ, followed by repair processes. This is frequently associated with bronchial hyper-responsiveness.

Do nasal mast cells release histamine on stimulation with substance P in allergic rhinitis?

The effects of nasal administration of increasing doses of exogenous substance P have been studied in patients with allergic rhinitis treated with placebo or with the H1 antagonist cetirizine (10 mg twice daily for 3 days). Responses to substance P were assessed by posterior rhinomanometry (measuring nasal airway resistance) and by measure of histamine, protein and albumin production and cell recovery in nasal lavage fluids before and after challenge. Substance P induced a dose-dependent increase in nasal airway resistance which was similar after treatment with either cetirizine or placebo (maximal increase in nasal airway resistance was 4.

In vitro bronchial hyperresponsiveness after lung transplantation in the rat.

In this study, we examined the effect of unilateral lung transplantation on in vitro responses of bronchial smooth muscle to electrical field stimulation (EFS) and exogenous acetylcholine (ACh). In syngeneic Lewis rats, we compared the contractile responses of the left hilar transplanted bronchus with that of the nontransplanted right bronchus and the left and right bronchi from control and sham-operated animals. Atropine-sensitive bronchial contraction to EFS was greater on left transplanted than on right nontransplanted bronchi at all frequencies and voltages used.

Application of new calculation algorithms to oxygenation parameters of cirrhotic patients. A comparison between calculated and measured data.

Oxygen status from both arterial and mixed venous blood was analyzed by reliable methods in 39 cirrhotic patients. These measured data were checked with computed oxygen parameters by new calculation algorithms. Calculated oxygen contents were higher than directly measured values but there was a highly significant correlation between them.

Is P50 the most representative P(SO2) to evaluate HbO2 affinity?

Off-line computer assistance allowed a correct visualization of the actual data included in any experimental whole oxygen-hemoglobin association curve. The affinity of hemoglobin for oxygen (characterized by the successive PO2 corresponding to any saturation value: P(SO2)), the shape of the association curve (Hill's curve and Hill's numbers) and the Bohr coefficients all along the oxygenation process, were determined with great accuracy. Results agreed with literature values obtained for successive steps of oxygenation.

Lung function of children treated for malignant extrapulmonary tumors.

Lung function was studied in 29 children suffering from extrapulmonary tumors of varying etiology (Wilm's tumor, n = 7; bone malignancy, n = 17; nasopharyngeal epithelioma, n = 5). Lung volume: vital capacity (VC) and functional residual capacity (FRC), lung mechanics: lung resistance (RL), dynamic lung compliance (CLdyn) and static lung compliance (CLstat) and lung transfer factor for CO (TLCO), and blood gases were determined at different stages of therapy: at t0, before any aggressive treatment for respiratory function; at t1, after the initiation of polychemotherapy with or without local tumoral treatment (surgery or local irradiation); at t2, less than 6 months after onset of thoracopulmonary irradiation (whole lung irradiation at 20 grays) (group I), or local thoracopulmonary irradiation at high exposure greater than 40 grays (group II); at t3 after more than 6 months following irradiation with chemotherapy maintained; at t4, after cessation of all treatment (mean: 25 months +/- 14 after cessation of treatment). At t0, lung function data in children without pulmonary metastases did not deviate from predicted values.

Lung mechanics and breathing pattern during wakefulness and sleep in children with enlarged tonsils.

Thirteen children (mean age, 45 months) with nocturnal symptoms of upper airway obstruction, the result of enlarged tonsils, were tested during wakefulness (W) and sleep (S) induced by chloral hydrate (less than or equal to 50 mg/kg). During W, lung mechanics, blood gas, breathing pattern, and airflows during tidal breathing were in the normal range. During S, total lung resistance increased significantly, and dynamic lung compliance and transcutaneous PO2 decreased significantly.

Occlusion pressure and breathing pattern in healthy children.

The breathing pattern was investigated in 62 children aged 4 to 16 years together with the mouth pressure generated 0.1 s after an occlusion at the endexpiratory level (P0.1).