Bronchial epithelium: morphology, function and pathophysiology in asthma

Human bronchial epithelium has a number of mechanical functions, including mucociliary clearance and protection against noxious agents. Bronchial epithelial cells are also able to release a variety of mediators, including cytokines, chemokines, growth factors, and arachidonic acid metabolites, which are able to regulate the recruitment, activation, and differentiation of inflammatory cells. They also modulate the function of the underlying smooth muscle cells by the release or metabolism of bronchoactive mediators. Finally, bronchial epithelial cells may control inflammatory reactions by the release of anti-inflammatory mediators or by the inactivation of pro-inflammatory mediators. Morphological or functional abnormalities of the bronchial epithelium may contribute to the initiation, perpetuation and prolongation of inflammatory processes and thereby to the pathogenesis of asthma. In this review, the morphology of the bronchial epithelium, its function with regard to host defense, and its immunological potential will be reviewed. Alterations associated with asthma will be emphasized.     

Frontometaphyseal dysplasia: evidence for autosomal dominant inheritance

Frontometaphyseal dysplasia is a syndrome that encompasses cranial hyperostosis, abnormal tubulation of cylindrical bones, and other skeletal and extraskeletal abnormalities. The most striking features are overgrowth of the supraorbital ridges which results in a Mephistophelian facial appearance and a radiographic configuration of the skull that has been likened to a soldier's helmet. Most patients have severe hearing loss, defective dentition, poorly developed musculature, and joint contractures. Dominant inheritance has been suggested in previous reports, but an appropriate pedigree has been documented in only one family. This paper describes three additional patients in two unrelated families: (1) an 8-year-old boy whose mother has mild metaphyseal dysplasia and several minor skeletal abnormalities that have occurred in patients with the syndrome; and (2) two maternal half-brothers. These cases provide additional evidence that frontometaphyseal dysplasia is an autosomal dominant trait with variable penetrance.     

Endothelium-medicated control of the coronary circulation. Exercise training-induced vascular adaptations

This review discusses the role of the endothelium in the regulation of coronary vascular function. The role of endothelium-mediated mechanisms at rest, during exercise, in exercise training-induced adaptations of coronary function and in the presence of coronary heart disease (CHD) are examined. Mechanisms of control of coronary blood flow are briefly discussed with emphasis on endothelium-mediated control of vascular resistance. The concept that the relative importance of vascular control mechanisms differs as a function of position along the coronary arterial tree is developed and discussed. Metabolic, myogenic and endothelium-mediated control systems contribute in parallel to regulating coronary blood flow. The relative importance of these mechanisms varies throughout the coronary arterial tree. Endothelium-dependent vasodilation contributes to maintenance of resting coronary blood flow but the endothelium's role in dilation of small resistance arteries, thereby increasing coronary blood flow during exercise, remains in question. In contrast, the endothelium plays an essential role in dilation of the conduit coronary arteries during exercise. Atherosclerosis and CHD convert this exercise-induced dilation to a vasoconstriction, apparently due to endothelium dysfunction. Long term increases in physical activity and exercise training alter the control of coronary blood flow. Adaptations in endothelium-mediated control play a role in these changes. However, the effects of the mode, frequency, and intensity of exercise training bouts and duration of training on adaptive changes in endothelial function have not been established. The role of the endothelium in control of the permeability characteristics of the exchange vessels in the coronary circulation is discussed. Current evidence indicates that vascular permeability is a dynamic characteristic of the vessel wall that is controlled, at least in part, by endothelium-dependent phenomena. Also, preliminary results indicate that exercise training alters microvessel permeability and the control of permeability in the coronary circulation. Further research is needed to provide clarification of the effects of exercise training on coronary endothelial control of vascular resistance and vascular permeability in atherosclerosis and CHD.     

Predictive accuracy of bioelectrical impedance in estimating body composition of Native American women

The predictive accuracy of race-specific and fatness-specific bioelectrical impedance analysis (BIA) equations for estimating criterion fat-free mass (FFM) derived from two-component (2C) and multicomponent (MC) models was examined. Body density (Db) of Native American women (n = 151) aged 18-60 y was measured by hydrostatic weighing at residual volume. Total body bone ash was obtained by dual-energy, x-ray absorptiometry. Cross-validation of the Rising (5), Segal (3), and Gray (4) equations against FFM2C yielded high correlation coefficients (0.86-0.95) and acceptable SEEs (1.47-2.72 kg). Cross-validation of these equations against criterion FFMMC, with Db adjusted for total body mineral, yielded similar correlation coefficients (0.82-0.94) and SEEs (1.69-2.80 kg). However, each BIA equation significantly overestimated FFMMC. A new race-specific BIA equation based on an MC model was developed: FFMMC = 0.001254(HT2)-0.04904(R) + 0.1555(WT) + 0.1417(Xc) - 0.0833(AGE) + 20.05 (R = 0.864, and SEE = 2.63 kg).     

Early pregnancy diagnosis in alpaca (Lama pacos) and llama (Lama glama) by ultrasound

An ultrasonography study of early pregnancy diagnosis was carried out in 19 alpacas and 12 llamas, after controlled matings. The aim was to determine the earliest gestational age at which pregnancy diagnosis by transrectal ultrasonography could be achieved, and to generate an empirical formula for gestational sac diameter (GSD) growth as a function of gestational age (GA), allowing an estimate of GA during the first month of pregnancy. We found that pregnancy diagnosis may be carried out as early as 9 days after mating in alpacas and 7 days in llamas. This diagnosis was found to be accurate at 23 days in alpacas and 34 days in llamas. The empirical relations that best describe the relationship between GSD and GA were GA = logGSD + 1.2339/0.0585 r = 0.85; P < 0.001 in alpacas, and GA = logGSD + 1.2649/0.0546 r = 0.77, P < 0.001 in llamas, where GA is measured in days and GSD in centimeters. Our results also indicate that ultrasonography is a reliable technique for early pregnancy diagnosis. Furthermore, the empirical formulae reliably make it possible to estimate GA from GSD during the first month of pregnancy and their use might improve the efficiency of camelid breeders.     

U-95666E: a potential anti-parkinsonian drug with anxiolytic activity

1. U-95666E, a D2 selective dopamine agonist, was investigated for its effect on rat striatal acetylcholine (ACh) concentration and the results were compared with those obtained with pergolide, pramipexole and bromocriptine under similar conditions. 2. U-95666E, pergolide, pramipexole and bromocriptine dose-dependently increased striatal ACh concentration both in the non-reserpinized and reserpinized rats. 3. Intrinsic activity of U-95666E was similar to pergolide and pramipexole in non-reserpinized rats, but significantly lower in reserpinized rats. 4. The sensitivity of these dopamine agonists for increasing ACh levels in the denervated as compared to innervated striatum were significantly (p < 0.01) higher. 5. U-95666E also has anxiolytic activity in mice. 6. In conclusion, U-95666E may have potential for the treatment of Parkinson's Disease and associated anxiety.     

The metabolic characteristics of patients with multiple sclerosis

A comprehensive clinical and biochemical evaluation has been carried out in patients with multiple sclerosis (MS). Measured in the patients' blood were levels of cholesterol, triglycerides, malonic dialdehyde, and superoxidedysmutase activity. The interrelationship revealed between the above measures provides a deeper insight into the mechanisms of pathometabolism in MS.