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Biomedical subjects

J Mersch

Publications and source records attributed to J Mersch.

11 recordsLinked to original sources
PubMed2000

Evaluating the reliability and utility of cumulative intake and output.

During times of scarce resources available for providing patient care, it becomes necessary to validate the effectiveness of standard practices that consume caregivers' time and efforts. Three nurse managers of nursing units serving diverse patient populations studied the effectiveness of continuous intake and output in estimating daily fluid balance. They examined 48-hour records of daily weight and intake and output of 73 patients and correlated the two. Their findings suggest that even when caregiver charting compliance is optimal, daily intake and output recording provides unreliable results. The authors recommend daily weights alone be adopted for all patients who are not experiencing acute renal conditions.

Adult↗
PubMed1998

In Situ Investigation of Trace Metal Availability in Industrial Effluents Using Transplanted Aquatic Mosses

Three species of aquatic mosses, Rhynchostegium riparioides, Fontinalis antipyretica, and Cinclidotus danubicus, were collected from the same reference location and exposed in five industrial effluents. The purpose was to test their suitability for assessing trace metal contamination under adverse and contrasted environmental conditions. Two distinct experiments of 16 and 11 days were conducted. In spite of short residence times in the effluents, the bryophytes were considerably affected at several sites, showing a light green to yellowish color, brown-edged leaves, and even dead strands. Cinclidotus danubicus was the most resistant whereas Fontinalis antipyretica was the most sensitive species. The observed physiological damage had no obvious incidence on the accumulation capacity of the mosses. The biomonitors provided time-integrated patterns of trace metal bioavailability (copper, chromium, nickel, lead, and zinc) in the effluents with a clear discrimination between poorly, moderately, and heavily polluted sites. Compared to water analyses, these more reliable indications could be obtained with a considerably reduced sampling design. When substantial accumulation occurred in mosses, the highest concentrations were systematically found in Rhynchostegium riparioides and the lowest in Cinclidotus danubicus. As only quantitative, not qualitative, differences were observed, all investigated moss species can be recommended for the assessment of trace metals in effluents at their discharge into the natural environment.

Journal Article↗
PubMed1997

The micronucleus assay in the zebra mussel, Dreissena polymorpha, to in situ monitor genotoxicity in freshwater environments.

Caged zebra mussels, Dreissena polymorpha, were transplanted to 6 monitoring sites receiving industrial effluents suspected of containing genotoxic chemicals. After a residence time of 2 months, the induction of micronuclei (MN) in haemocytes was determined as a criterion for genetic damage. The mean MN frequencies observed in mussels exposed to effluents ranged between 5.0 and 8.8/1000. These rates were significantly higher than the baseline level of 2.0/1000 recorded in a concurrent control mussel group reintroduced at the reference location. Biological fitness descriptors (mortality, attachment biotest, condition index, gonadic index) revealed no relationship between the general well-being of the mussels exposed under contrasted environmental conditions and the frequency of MN induced in their haemocytes. The biological feasibility of the transfer technique of zebra mussels, together with a moderate, but significant, inducibility of MN, are major features towards the development of a first tool for in situ monitoring of genotoxicity in freshwater environments using a common indicator species.

Animals↗
PubMed1996

Induction of micronuclei in haemocytes and gill cells of zebra mussels, Dreissena polymorpha, exposed to clastogens.

Zebra mussels, Dreissena polymorpha, were exposed to four directly acting reference clastogens (mitomycin C, bleomycin, dimethylarsinic acid and potassium chromate) under laboratory conditions. The aim was to examine the inducibility of micronuclei (MN) in haemocytes and gill cells. Positive responses were observed in both tissues for all four substances used under the given test conditions. The mean MN frequencies in treated mussels ranged between 3.2 and 6.9/1000 in haemocytes and between 5.4 and 6.7/1000 in gill cells. The spontaneous MN levels averaged 1.2 and 2.8/1000 in haemocytes and gill cells, respectively. The MN induction capacity of the different chemicals was equivalent in both tissues, except for the treatment with dimethylarsinic acid which generated a significantly higher MN rate in gill cells than in haemocytes. Several characteristics suggest that haemolymph is the more appropriate test tissue for environmental genotoxicity assessment: (1) a shorter preparation time of slides, (2) a more accurate identification of unambiguous MN, (3) a lower baseline MN frequency and a higher induction factor.

Animals↗
PubMed1989

Renal lesions and clinical findings in thalassemia major and other chronic anemias with hemosiderosis.

Renal lesions found in 21 autopsied patients with hemosiderosis, 18 with beta-thalassemia, two with Blackfan-Diamond anemia, and one with aplastic anemia included: cellular glomeruli with increased mesangial matrix; hemosiderin deposit in visceral and parietal glomerular epithelial cells; greater hemosiderin deposit in terminal straight portions of proximal convoluted tubules and distal convoluted tubules than in connecting segments, or collecting tubules, connective tissue ferrugination; lipofuscin in tubular epithelium and vascular smooth muscle; infrequently, intimal or medial arterial thickening, and, in one patient with thalassemia, an infarct resulting from arterial thrombus. The progression of these lesions over the course of disease, and possible effects on the various lesions of high transfusion regimen, oral pancreatin, vitamin E supplementation, or treatment with intramuscular, subcutaneous, or intravenous desferrioxamine were evaluated. The results of urine and renal function studies of 4 of the autopsied patients (3 thalassemia, 1 Blackfan-Diamond anemia), and 14 patients with thalassemia and 4 with Blackfan-Diamond anemia who were not autopsied, are presented. Rarely significant until preterminal stages, the renal functional changes reflect distal more than proximal tubule dysfunction.

Adolescent↗
PubMed1988

[High-frequency artificial respiration. II. Intratracheal high-frequency pressure changes with a rotation-valve catheter].

From the history of ventilatory support, the early studies of Auer und Meltzer only now seem to find a functional explanation. A rotating valve mounted on the tip of an endotracheal tube delivers a widespread gas bolus. The turbulent flow acts as a stirring device on the intrapulmonary gas volume. The method reduces the directional selectivity that typically limits the efficiency of jet ventilation. Systematically changing the rotational frequency between 10 and 80 Hz allows sequential stimulation, compartment by compartment, of the entire lung, which also gives rise to frequency-dependent local air-trapping that sequentially inflates different compartments. Jet ventilation and high-frequency oscillation were compared in dogs with the rotating valve tube by taking blood gas samples from 4-6 intrapulmonary veins: jet ventilation is characterized by preponderant ventilation of lung compartments opposite the lower aperture of the endotracheal tube. High-frequency oscillation induces a frequency dependent repartition of alveolar ventilation. The rotating valve tube definitely contributes to the homogenisation of alveolar ventilation in a manner that is less dependant upon segmental compliance than conventional ventilation.

Animals↗