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W Meulemans

Publications and source records attributed to W Meulemans.

5 recordsLinked to original sources

Nutritional assessment: the problem of clinical-anthropometrical mismatch.

OBJECTIVE: To study risk factors for and prevalence and validity of clinical-anthropometrical mismatch (CAM) defined as the presence of clinical signs of protein-energy malnutrition despite normal weight-for-age (WFA). DESIGN: A semi-longitudinal study of nutrition and morbidity with a longitudinal assessment of mortality. SETTING: The rural health zone of Bwamanda in Northern Zaire. SUBJECTS: 4238 children of age 0-6 years enrolled by random cluster sampling. INTERVENTION: Clinical nutritional staging, anthropometry, diagnosis of diarrhoea and severe respiratory infection in the rainy (first survey) and the subsequent dry season (second survey). Recording of mortality during 27 months after the second survey. RESULTS: Prevalence of CAM was high above various cut-off levels of WFA and was accompanied by increased morbidity and long-term mortality. Of all the children with clinical signs of malnutrition, a high proportion had normal WFA. CAM was associated with weight loss within the limits of the international reference. CONCLUSIONS: If a child has a normal weight but clinical malnutrition signs are present, the clinical diagnosis should prevail. Weight charts are not fully appropriate for nutritional classification purposes. The clinical nutritional staging used in this study is sufficiently reproducible and capable of identifying children with functional malnutrition.

Anthropometry↗

Transport of the cationic fluorochrome rhodamine 123 in an insect's Malpighian tubule: indications of a reabsorptive function of the secondary cell type.

The pathway of rhodamine 123 was examined after injection into Sarcophaga flies and after in vitro labeling of the Malpighian tubules. After in vitro labeling the primary cells only retained this potential-sensitive dye for a short period while all secondary cells accumulated the dye from the tubule lumen. In vivo the secondary cells also accumulated rhodamine 123 from the lumen, but the primary cells in the distal parts of all four tubules retained the dye for prolonged periods. This was most pronounced in the distal part of the anterior Malpighian tubules, where rhodamine 123 was eventually precipitated on the luminal concretions. Rhodamine 123 initially accumulated in the secondary cell mitochondria and eventually in intensely fluorescing vesicles, probably lysosomes. No evidence for endocytotic processes from the lumen was found using Lucifer Yellow CH, fluorescent dextrans and fluorescent albumin. Prior incubation with the ionophores valinomycin, nigericin, CCCP (all 1 micrograms/ml), dinitrophenol (1 mM) and NaN3 (10(-2) M) inhibited the selective accumulation of rhodamine 123 to a large extent while monensin (1-5 micrograms/ml) showed little inhibitory effect. Furthermore, only cationic and no anionic or neutral dyes were accumulated by the secondary cells. In the fleshfly Calliphora and the fruitfly Drosophila, the dye rhodamine 123 also selectively accumulated in the secondary cells, as well in vitro as in vivo.

2,4-Dinitrophenol↗

Cytoskeletal F-actin patterns in whole-mounted larval and adult salivary glands of the fleshfly, Sarcophaga bullata.

The patterns of filamentous actin were analysed in different larval, pupal and adult stages in the salivary glands of the fleshfly Sarcophaga bullata. Using the rhodamine labelled phalloidin staining method in combination with detergent extraction specific actin filament distribution was detected. The salivary glands which are histolysed during the process of metamorphosis show distinct cellular morphology and actin filament patterns in larvae and adults. The large third instar larval salivary gland cells contain a well developed apicolateral microvillar zone. In third instar larvae this microvillar zone invaginates and expands in the basal part of the lateral membranes. Larval salivary gland cells also contain numerous parallel basal actin bundles. The larval glands are histolysed during metamorphosis and adult glands are formed out of the imaginal cell group. At the onset of metamorphosis these basal actin bundles form a network of crossing bundles. The filamentous actin patterns of the proximal part of adult gland cells is confined to the apicolateral microvillar membranes. The cells in the distal, tubular part of the adult salivary glands show intense staining of their folded lateral membranes.

Actin Cytoskeleton↗

Cytoskeletal F-actin patterns in whole-mounted insect Malpighian tubules.

The distribution of actin filaments in Malpighian tubules of the fleshfly Sarcophaga bullata (Parker) was investigated before and after metamorphosis by means of the rhodamine phalloidin staining method. The numerous primary cells show a pattern of thick basal actin bundles resembling stress fibres of cultured cells, while the apical microvillar zone shows a bright and homogeneous labelling. The less abundant stellate cells contain no such basal actin bundles and their apical microvillar zone gets only faintly stained. Late larval stages display fingerlike infoldings and an increased actin filament concentration at the apical membrane of the stellate cells. During metamorphosis the Malpighian tubules dedifferentiate and eventually redifferentiate to give rise to adult tubules resembling larval ones. The different types of actin filament organisation in the primary and stellate cells of the Malpighian tubules are discussed.

Actin Cytoskeleton↗