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M Vernet

Publications and source records attributed to M Vernet.

At least 73 records · Page 4Linked to original sources

[The coefficient of saturation of iron in transferrin].

Theoretical iron fixation capacity of transferrin (FCT) can be calculated on its immunochemical titration: (FCT (mumol/l = transferrin (g/l) x 25). Today, its reckoning is more advisable to serum total iron binding capacity measurement. The authors studied the effects of this new proceeding upon usual values interval of transferrin saturation (i.e. serum iron/FCT ratio). The mean value and the distribution of transferrin saturation appear displaced with regard to those achieved by chemical measurement of serum total iron binding capacity. We discuss interpretation of transferrin saturation related to its methods of determination and its semiological interest.

Adolescent↗

[Reference values of serum transferrin in newborn infants, children and adults].

The authors have studied the evolution of serum transferrin concentration in relation with age (newborn child, infant, adult). The mean concentration of serum transferrin is the lowest for neonates (2.15 g/l). At 10 months, it increases to reach a value of about 3.10 g/l then reduces at 24 (3.0 g/l) and 48 months (2.8 g/l). By the 4 to 18 years subjects, serum transferrin is approaching that of 10 months children (3.15 g/l). At last it doesn't support any modification during all the adult life. The diversity of the obtained results dependent of the used technique and/or of the laboratory, justifies that each one defines his own reference values.

Adolescent↗

[Tissue and blood ferritins and isoferritins].

Ferritins which can store excess iron are localised principally in tissue. Ferritins have on apoprotein shell which is composed of 24 sub-units, from 2 types of sub-units: "H" (molecular weight about 21 000) and "L" (molecular weight about 19 000) that assemble in different proportions and give multiple forms. Protein pattern depends on tissue nature. Since 1972, radio-immunology assays have shown very low serum ferritin levels. There is a good correlation between these levels and the amount of storage iron in the body. However it was demonstrated that elevation of serum ferritin could also occur without iron metabolism trouble by various mechanisms.

Chemical Phenomena↗

[Legionnaires' disease. First observations in Catalonia (author's transl)].

The authors report the first two cases of legionnaires' disease from Catalonia. Both patients were chronic bronchitic males, and the cases were sporadic. The onset of the disease was characterized by a febrile illness with muscle and joint pains, respiratory symptoms (cough and mucous sputum production), and mental changes. There were no digestive complaints. Pulmonary consolidation occurred in both patients in the left upper lobe. Blood chemistries disclosed the existence of an absolute lymphopenia, altered liver function tests, and elevated CPK levels. Bacterial cultures of blood and sputum, respiratory virus screening (influenza A and B, parainfluenza 1, 2 and 3, and adenoviruses), and tests for Mycoplasma pneumoniae, Coxiella burnetti and Chlamydia psittaci were all negative. Antibody titers against Legionella pneumophila by indirect immunofluorescence were 1/1024 (positive) for serotype 1 and 1/1024 (positive) for serotype II in one patient, and 1/1024 (positive) for serotype I and 1/128 (negative) for serotype II in the other patient. The authors review the epidemiological, clinical, biochemical and diagnostic aspects of legionnaires' disease, which knowledge will undoubtedly allow to detect an increasing number of cases.

Bronchitis↗

[Urinary tract infection in postmenopausal diabetic women. Clinical survey of hospital and nonhospital populations (author's transl)].

The incidence and clinical course of urinary tract infections in postmenopausal diabetic patients in comparison to non-diabetic women have been evaluated. All cases with former history of urinary instrumentation or underlying conditions favoring urinary infections were rejected. Urinary tract infection was present in 14.9 percent of postmenopausal diabetics versus 10.5 percent in the non-diabetics. The incidence of urinary tract infection in premenopausal women was 12.5 percent. Urinary pathogenes showed similar incidence rate in both groups: E. coli (41 versus 57 percent), P. mirabilis (20 versus 28 percent) and Klebsiella (11 versus 20 percent). Diabetic women showed a higher rate of sepsis and infection recurrence than non-diabetic (10.7 and 17.8 percent versus 2.6 and 2.6 percent, respectively). Severe impairment of renal function (plasma creatinine clearance > 2 mg/100 ml) was registered in 12.5 percent of postmenopausal patients with diabetes mellitus, but none of the non-diabetics suffered renal damage (p < 0.01).

Aged↗

Ozone and UV radiation over southern South America: climatology and anomalies.

Ozone and UV radiation were analyzed at eight stations from tropical to sub-Antarctic regions in South America. Ground UV irradiances were measured by multichannel radiometers as part of the Inter American Institute for Global Change Radiation network. The irradiance channels used for this study were centered at 305 nm (for UV-B measurements) and 340 nm (for UV-A measurements). Results were presented as daily maximum irradiances, as monthly averaged, daily integrated irradiances and as the ratio of 305 nm to 340 nm. These findings are the first to be based on a long time series of semispectral data from the southern region of South America. As expected, the UV-B channel and total column ozone varied with latitude. The pattern of the UV-A channel was more complex because of local atmospheric conditions. Total column ozone levels of < 220 Dobson Units were observed at all sites. Analysis of autocorrelations showed a larger persistence of total column ozone level than irradiance. A decreasing cross-correlation coefficient between 305 and 340 nm and an increasing cross-correlation coefficient between 305 nm and ozone were observed at higher latitudes, indicating that factors such as cloud cover tend to dominate at northern sites and that ozone levels tend to dominate at southern sites. These results highlight the value of long-term monitoring of radiation with multichannel radiometers to determine climatological data and evaluate the combination of factors affecting ground UV radiation.

Journal Article↗

Simulation of ozone depletion using ambient irradiance supplemented with UV lamps.

In studies of the biological effects of UV radiation, ozone depletion can be mimicked by performing the study under ambient conditions and adding radiation with UV-B lamps. We evaluated this methodology at three different locations along a latitudinal gradient: Rimouski (Canada), Ubatuba (Brazil) and Ushuaia (Argentina). Experiments of the effect of potential ozone depletion on marine ecosystems were carried out in large outdoor enclosures (mesocosms). In all locations we simulated irradiances corresponding to 60% ozone depletion, which may produce a 130-1900% increase in 305 nm irradiance at noon, depending on site and season. Supplementation with a fixed percentage of ambient irradiance provides a better simulation of irradiance increase due to ozone depletion than supplementation with a fixed irradiance value, particularly near sunrise and sunset or under cloudy skies. Calculations performed for Ushuaia showed that, on very cloudy days, supplementation by the square-wave method may produce unrealistic irradiances. Differences between the spectra of the calculated supplementing irradiance and the lamp for a given site and date will be a function of the time of day and may become more or less pronounced according to the biological weighting function of the effect under study.

Canada↗

[Recommended algorithms of prescription in the diagnosis of iron deficiency and overload].

In view of the recent development of new tests of biochemistry and molecular biology the assessment of iron status should be reconsidered and updated. The French Society of Clinical Biology (SFBC) and the French Society of Hematology (Cellular Hematology Group) recommend algorithms in the diagnosis of iron deficiency and iron overload bearing in mind the best efficiency and health economy. These recommendations are based on the known sensibility and specificity of each test. The analytical requirements for the determination of the tests as well as the clinical and biological signs evoking an iron deficiency or overload are recalled.

Adult↗

[Serum ferritin assay. Value and limitations].

There is a good correlation between serum ferritin and the amount of iron stored in the body. Reduced levels of serum ferritin are always found in iron deficiency but elevation of serum ferritin can occur without any iron overload. According to pathological situations, red cell ferritin, glycosylated ferritin or acidic ferritin measurements are useful tests for the differential diagnosis of increased serum ferritin concentration.

Adolescent↗