The Reactions of Oxicam and Sulfoanilide Non Steroidal Anti-Inflammatory Drugs with Hypochlorous Acid: Determination of the Rate Constants with an Assay Based on the Competition with Para-aminobenzoic Acid Chlorination and Identification of Some Oxidation Products

Hypochlorous acid (HOCl) is an oxygen-derived species involved in physiological processes related to the defence of the organism that may cause adverse effects when its production is insufficiently controlled. In order to examine its reactivity with potential scavenging molecules from the non steroidal anti-inflammatory drugs (NSAIDs) family, a competition assay based on para-aminobenzoic acid (PABA) chlorination was developed. The original optimised in vitro fluorimetric procedure offered the possibility to determine rate constants (ks) for the reaction with HOCl in physiologically relevant conditions. The specificity of the system was improved by a liquid chromatography (LC) which allows the separation of the drugs and their oxidation products. After determination of the rate constant for PABA chlorination by HOCl (mean +/- SD in M(-1) s(-1): 4.3 +/- 0.3 x 10(3)), the applied mathematical model for a chemical competition permits to obtain linear curves from competition studies between several NSAIDs and PABA. Their slopes provided the following rate constants for the different studied drugs: tenoxicam: 4.0 +/- 0.7 x 10(3), piroxicam: 3.6 +/- 0.7 x 10(3), lornoxicam: 4.3 +/- 0.7 x 10(3), meloxicam: 1.7 +/- 0.3 x 10(4), nimesulide: 2.3 +/- 0.6 x 10(2). Meloxicam therefore reacted significantly faster than the other oxicams and nimesulide, which is the weakest scavenger of the studied series. The identification of some of the oxidation products by NMR or MS permitted to explore the reaction mechanism and to examine some aspects of the structure/activity relationships for the molecules of the same chemical family.

[Legislation and risk potential of harmful use of complementary nutrition supplements]

Ophthalmologists have to deal with the prescription of commercial preparations containing essential nutrients and/or phytonutrients with antioxidant or other properties that are presented as able to protect the eyes against several degenerative diseases. This kind of preparation has to be in conformity with the Belgian Legislation on food and food products that mentions the nature and the quantity of active components they are allowed to contain. Nevertheless, they cannot mention allegations related to health or to the treatment of diseases. Carotenoids such as lutein, zeaxanthin or lycopene are not covered by this Legislation as they are not pro-vitamin A. Therefore, they have to be considered as potentially harmful according to the Belgian Legislation dated March 3, 1992. Finally, their long-term toxicity has never been documented and no dietary recommendations exist as far as they are concerned. On the contrary, several warnings have been published about their chronic intake at supranutritional doses. Even if a complementary administration of these carotenoids is in some way meaningful, it is a pity that their commercial use has preceded the scientific data that remain necessary to collect about them. It seems preferable to advise "dietary" alternatives and avoid the use of unbalanced food complements.

Serum selenium and cancer mortality: a nested case-control study within an age- and sex-stratified sample of the Belgian adult population

OBJECTIVE

To study the predictive power of serum selenium with regard to cancer mortality in a large sample of the Belgian population given the lack of coherence in the results of observational epidemiological studies in this domain.

DESIGN

A prospective case-control study within a stratified sample of the Belgian male and female population.

SUBJECTS

A total of 201 cases randomly selected from all cancer deaths (N=343) during a 10-y mortality follow-up of a large age- and sex-stratified sample of the total Belgian population aged 25-74 y were matched for age and gender with 603 controls.

STATISTICS

Conditional logistic regression for both univariate and multivariate analyses using tertile distribution of serum selenium in controls. Odds ratios (ORs) are adjusted for 10 baseline characteristics.

RESULTS

Unadjusted ORs of cancer deaths taking the highest tertile of serum selenium as a reference: in male subjects T1/T3 is 2.2 (CI 1.3-3.7) (P for trend 0.011), whereas in female subjects a nonsignificant OR of 0.8 is observed. In multivariate analyses, no significant modifications of the ORs are observed for the predictive relation of serum selenium with cancer mortality. Besides serum selenium, beta-carotene intake and smoking are independent predictors in male subjects.

CONCLUSIONS

In this nested case-control study of a stratified sample from the Belgian population, serum selenium is an independent predictor of cancer mortality in male subjects only, in a country with rather high serum selenium levels with respect to most other European countries.

Selenium, iodine and fungal contamination in Yulin District (People's Republic of China) endemic for Kashin-Beck disease

We studied the status of selenium, iodine and fungal contamination in 353 school children (age 5-14 years) from four rural villages in the District of Yulin. In three villages Kashin-Beck disease (KBD) was endemic, whereas there were no cases of KBD in the fourth village. Clinical, biological and radiological examinations (right hand) were performed and KBD was established by X-ray diagnosis. The prevalence rate of KBD was 30.2%, 44.2% and 45.3% in the three endemic villages. Mean hair selenium and urine iodine concentrations were lower in affected than in unaffected children and fungal contamination in cereal grains stored in families with KBD was more elevated than in families without KBD. Low hair selenium concentration and presence of fungal cereal contamination were significantly associated with an increased risk of KBD, but low urine iodine was not.

Zinc supplementation increases bone alkaline phosphatase in healthy men

Zinc takes part in the metabolism of bone as a constituent of the matrix and as an activator of several metallo-enzymes. Animal in vitro and in vivo studies strongly suggest that zinc supplementation could stimulate bone formation and inhibit bone resorption but data in humans remain rare. The biological effects of 50 mg zinc given orally as gluconate in 20 healthy male volunteers were investigated in a 12 weeks double-blind placebo-controlled randomized trial. To investigate bone turnover, total alkaline phosphatases activity (ALP), bone specific alkaline phosphatase activity (BAPE) and BAP mass (BAP-M) concentration were measured as parameters of bone formation while urine calcium and C-terminal collagen peptide were determined as parameters of bone resorption. Samples were obtained in fasting subjects at baseline and after 6 and 12 weeks. In zinc treated subjects, a significant increase was observed at least after 12 weeks in total ALP (p < 0.01), BAP-M (p < 0.05) and BAP-E (p < 0.02). These parameters did not significantly change in the placebo group. Urine zinc/creatinine ratio significantly increased after 6 (p < 0.03) and 12 weeks (p < 0.04) in the zinc-treated group and was significantly different from the placebo group (p < 0.002). There was no significant effect of zinc supplementation on parameters of bone resorption. In conclusion, zinc supplementation at supraphysiological doses increased parameters of bone formation in healthy men while parameters of bone resorption remained unchanged.

Temporal relationship between immune cell influx and the expression of inducible nitric oxide synthase, interleukin-4 and interferon-gamma in pancreatic islets of NOD mice following adoptive transfer of diabetic spleen cells

Beta cell destruction in NOD mice can be accelerated by adoptive transfer of diabetic spleen cells into irradiated adult NOD mice. Here mice receiving diabetic spleen cells were examined at days 0, 7, 14, 21 and at onset of diabetes for the resulting insulitis and the number of intra-islet CD4 and CD8 cells and macrophages. The progression of insulitis and the number of intra-islet CD4 and CD8 cells and macrophages were correlated with the expression and co-localization of inducible nitric oxide synthase, interferon-gamma and interleukin-4 by dual-label light and confocal immunofluorescence microscopy. Diabetes developed in 7/8 mice by 27 days following cell transfer. The insulitis score increased slightly by day 7 but rose sharply at day 14 (p = 0.001) and was maintained until diabetes. The mean number of intra-islet CD4 and CD8 cells and macrophages showed a similar trend to the insulitis scores and were present in almost equal numbers within the islets. Immunolabelling for inducible nitric oxide synthase was observed at day 7 in only some cells of a few islets but increased sharply from day 14. It was restricted to islets with insulitis and was co-localized in selective macrophages. Weak intra-islet interleukin-4 labelling was observed at days 7 and 14 but became more pronounced at day 21 and at onset of diabetes, being present in selective CD4 cells. Intra-islet labelling for interferon-gamma was first observed at day 21, but became more intense at onset of diabetes and was co-localized in a proportion of macrophages. Both cytokines were expressed in islets with advanced insulitis. Interferon-gamma staining was also observed within endothelial cells located in the exocrine pancreas. We conclude that transfer of diabetic spleen cells results in a rapid influx of CD4 and CD8 cells and macrophages within the pancreas of recipient mice. During the period of heightened insulitis, selective immune cells begin to express inducible nitric oxide synthase and the opposing cytokines, interferon-gamma and interleukin-4. Expression of these molecules becomes more pronounced immediately prior to and during the onset of diabetes.

[Kashin-Beck disease in China: osteochondrodysplasia related to nutrition and environment]

Kashin-Beck disease is a endemic juvenile osteochondrodysplasy, whose association with selenium deficiency and/or mycotoxin toxicity has been corroborated by epidemiological studies in China, including Tibet. Iodine deficiency appears to be a new etiological factor. Together with the geographical and epidemiological exploration of the disease, scientific multidisciplinary investigations (clinics, radiological imaging, histology, environmental and molecular biology) should afford to understand the cause of the disease before it disappears as a consequence of the evolution of the Chinese Society, including in Tibet.

Sideroxylonal C, a new inhibitor of human plasminogen activator inhibitor type-1, from the flowers of Eucalyptus albens

Sideroxylonal C (3), a new phloroglucinol dimer, was isolated from the flowers of Eucalyptus albens through bioassay-guided fractionation. The structure elucidation was based on 1D and 2D NMR experiments, MS analysis, and comparison with sideroxylonals A (1) and B (2). Sideroxylonal C inhibited human plasminogen activator inhibitor type-1 at 4.7 microM without any significant effect on human tissue plasminogen activator.

Trace element deficiency and toxicity

Trace elements are involved in enzymatic activities, immunological reactions, physiological mechanisms and carcinogenesis. Deficiency in some trace elements, such as iron and iodine, is still an important health problem, especially in developing countries. Some groups of individuals are more likely to develop trace element deficiency. The role of trace elements deficiency is suspected in various clinical situations and is now confirmed by well designed supplementation studies. Although toxicity of trace elements with clinical manifestations is rare, it has been observed that manganese toxicity may occur in patients receiving parenteral nutrition. Recent data about trace elements deficiency and toxicity are indicated in this review.

Forward-masked intensity discrimination: duration effects and spectral effects

Three experiments were completed to examine the effect of masker duration and spectrum on forward-masked intensity discrimination. Four listeners participated in each experiment. Intensity discrimination was measured in quiet and in the presence of forward maskers using adaptive forced-choice procedures. The standard duration was either short (10 ms) or long (250 ms) in experiment 1 and short (10 ms) in experiment 2. The standard always occurred 100 ms after the offset of the masker. In the first experiment employing 1.0-kHz maskers and standards, a short duration masker (10 ms) produced more masking than a long duration masker (250 ms). A mid-level elevation of the Weber fraction was observed for all conditions. To ensure that the results of experiment 1 were not influenced by off-frequency listening, the second experiment employed a broadband noise masker. As before, a short duration (10 ms) masker produced more masking than a long duration masker (100 ms) and a mid-level elevation of Weber fractions was observed. This outcome is inconsistent with a peripheral sensory effect for which an increase in masker duration should result in a greater amount of adaptation, and, as a consequence more masking. A third experiment employing a broadband noise masker and standard showed the greatest amount of masking for low-level standards, but only when the duration of the masker and standard was short. This result is similar to one seen for a single listener in the first experiment for short duration tonal maskers and standards. For this listener, a second tone presented at 4.133 kHz presented simultaneously with the 1.0 kHz masker reduced significantly the amount of masking for low-level standards, but the mid-level elevation of the Weber fraction remained. Taken together, these results suggest that perceptual similarity plays a role in forward-masked intensity discrimination but does not account entirely for the mid-level elevation of the Weber fraction.

Deficiency in antioxidant factors in patients with alcohol-related chronic pancreatitis

Free radicals have been suspected to play a role in the pathogenicity of alcohol-related chronic pancreatitis. The aim of this study was to determine the status of several antioxidant parameters in these patients and examine the factors that are likely to influence them. Thirty-five subjects (23 males and 12 females, mean age 48 +/- 8 years) with disease proven by endoscopic pancreatography and 14 healthy controls (6 males and 8 females, mean age 44 +/- 7 years) were included in the study. Biochemical antioxidant parameters included: selenium, zinc, and copper levels in plasma; glutathione peroxidase in plasma and erythrocytes; plasma malondialdehyde concentrations assessed by thiobarbituric acid reactants; and serum vitamin E and A levels. Selenium and vitamin E oral intake was assessed by a five-day diet analysis. Hemoglobin (130 +/- 16 vs 143 +/- 15 g/liter), vitamin E (8 +/- 5 vs 16 +/- 9 mg/liter), vitamin A (30 +/- 11 vs 49 +/- 12 micrograms/dl), selenium (54 +/- 20 vs 87 +/- 11 micrograms/liter), and plasma glutathione peroxidase (903 +/- 313 vs 1326 +/- 168 units/liter) were significantly lower in patients than in controls (P < 0.05). In contrast, white blood cell count, C-reactive protein, and plasma copper levels were significantly higher in patients than in controls. Cholesterol, triglycerides, iron, ferritin, total proteins, zinc, and malondialdehyde were not different. Vitamin E was lower in patients with steatorrhea, while vitamin A was lower in patients with concomitant diabetes mellitus. Dietary intakes were not different between patients and controls. In conclusion, patients with alcohol-related chronic pancreatitis have low blood levels in many antioxidant factors. Dietary intakes of some of them (selenium and vitamin E) are adequate, however. Such deficiencies are secondary to pancreatic insufficiency and probably to increased requirements related to enhanced oxidative stress.

Reference values for serum selenium in various areas-evaluated according to the TRACY protocol

Published reports on selenium concentrations in serum and plasma were critically reviewed according to the criteria set up by the expert group of the international project TRACY. The aim was to examine both pre-analytical (sampling conditions and characteristics of the group) and analytical factors described in papers to establish reference values for evaluation of persons with deficiency or excessive exposure to the element. Out of 291 papers published during the period 1983 to 1993, which we reviewed, 36 were considered suitable for the TRACY project. In order to eliminate sources of variation due to age and health status, only data concerning healthy adults were retained. Of the sampling and other pre-analytical factors, geographical area and time of sampling were found to be of high importance. Gender, occupation, diet data and use of supplements or medications were also considered important determinants, but ethnic origin, smoking and fasting, contamination control and storage of sample were held to be of relatively low importance. Concerning analytical factors, accuracy criteria were generally satisfied although not extensively documented. Reference materials for serum selenium, which contribute to better analytical reliability have been available for over 10 years. Due to the geographical variation of selenium intake, one universal reference serum selenium value for the world's population was not feasible but the data selected allowed documentation of the serum selenium concentration levels among populations of different areas, mostly in Europe. Critical use of the published TRACY criteria in future papers will certainly extend their reliability and scientific significance.

Linear and non linear competition plots in the deoxyribose assay for determination of rate constants for reaction of nonsteroidal antiinflammatory drugs with hydroxyl radicals

Performing the deoxyribose (DR) assay for determination of the rate constants for reaction of non steroidal antiinflammatory drugs with hydroxyl radicals led to some unusual competition plots. The molecules from the arylpropionic family of drugs: ibuprofen, flurbiprofen, ketoprofen and naproxen produced the linear relationship. However, acemetacin, diclofenac Na, flufenamic acid, indometacin, indometacin, niflumic acid, tolmetin Na and sulindac presented non linear competition plots manifesting at relatively low drug concentrations. This effect was corrected by increasing DR concentrations from 2.8 mM to 15 mM. The modification did not affect rate constants values for those derivatives which already presented a linear plot at 2.8 mM, but allowed to calculate rate constants for other compounds. It is suggested that the experimental conditions have to be adapted particularly for those derivatives with a relatively high rate constant for reaction with the radical species. The oxicam derivatives (tenoxicam and piroxicam) presented another kind of deviation that revealed a prooxidant effect in this system: non linear plots were also observed at relatively low drug concentrations, but in the opposite direction than for the other molecules. This last effect was independent of DR concentration but could be corrected by increasing ascorbate concentration in the system.

Precision and accuracy of in vivo bone mineral measurement in rats using dual-energy X-ray absorptiometry

The aim of this study was to evaluate the precision and accuracy of dual-energy X-ray absorptiometry (DXA) for measuring bone mineral content at different sites of the skeleton in rats. In vitro the reproducibility error was very small (< 1%), but in vivo the intra-observer variability ranged from 0.9% to 6.0%. Several factors have been shown to affect in vivo reproducibility: the reproducibility was better when the results were expressed as bone mineral density (BMD) rather than bone mineral content (BMC), intra-observer variability was better than the inter-observer variability, and a higher error was observed for the tibia compared with that for vertebrae and femur. The accuracy of measurement at the femur and tibia was assessed by comparing the values with ash weight and with biochemically determined calcium content. The correlation coefficients (R) between the in vitro BMC and the dry weight or the calcium content were higher than 0.99 for both the femur and the tibia. SEE ranged between 0.0 g (ash weight) and 2.0 mg (Ca content). Using in vitro BMC, ash weight could be estimated with an accuracy error close to 0 and calcium content with an error ranging between 0.82% and 6.80%. The R values obtained between the in vivo and in vitro BMC were 0.98 and 0.97 respectively for femur and tibia, with SEE of 0.04 and 0.02 g respectively. In conclusion, the in vivo precision of the technique was found to be too low. To be of practical use it is important in the design of experimentation to try to reduce the measurement error.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma and liver selenium levels in the rat during supplementation with 0.5, 2, 6, and 15 ppm selenium in drinking water

Plasma and liver selenium of Wistar rats were determined after 1, 3, and 6 mo supplementation with 0.5, 2, 6, or 15 ppm selenium as sodium selenite in drinking water. Plasma selenium was not different from control values at additional intake of 0.5 ppm but increased above usual levels at higher intakes. A highly significant correlation was observed between the total quantity of selenium ingested and plasma selenium after 1 mo treatment (r = 0.99, p < 0.01), but was less pronounced after 3 and 6 mo (0.94, p < 0.05, and 0.78, p < 0.05, respectively). The decrease in plasma selenium with time of treatment was more pronounced at higher intakes. There was also a highly significant correlation between total selenium intake and liver selenium concentration (r = 0.99, p < 0.01) after 1 mo of treatment, but this time liver selenium did not change with time, and the correlation remained highly significant throughout the investigation. Liver selenium therefore appears as a more sensitive and more representative measure of selenium intake than plasma selenium. Most supplements did not affect body weight and survival of animals, except when the diet was supplemented with 15 ppm for 6 mo; however, alterations in biochemical parameters concerning lipid status and hepatic function were observed at levels above 2.0 ppm.

[Some factors influencing the bioavailability of zinc in oral pharmaceutical dosage forms]

Absorption and distribution of zinc in 6 dosage forms were determined in 10 subjects by performing a pharmacokinetic study of the serum zinc profile after oral administration of a dose corresponding to 45 mg elemental zinc. The aim of this study was to document the influence on zinc bioavailability of factors such as the chemical form of zinc, the pharmaceutical form, and the division of the administered dose. The pharmacokinetic parameters indicate for gelatin capsules without excipients taken in a non divided dose better performances for zinc gluconate in comparison to zinc sulfate. Concerning the pharmaceutical form, little difference is observed between an aqueous solution and a gelatin capsule for zinc sulfate and a non divided dose; on the contrary, a commercial gelatin capsule containing zinc gluconate with various excipients show better performances than gastro-resistant tablets when zinc intake is 3 times 15 mg. Finally, the division in 3 parts of the dose of zinc sulfate given in gelatin capsules very significantly improves zinc absorption. These results demonstrate the interest of the developed pharmacokinetic method in the assessment of zinc bioavailability in different pharmaceutical dosage forms.

Clinical implications of trace elements in endocrinology

The implications of essential trace elements in endocrinological processes, mainly thyroid function, growth, gonadal function, adrenal hormones, prolactin, glucose homeostasis, calcium-phosphorus metabolism, and thymulin activity, are reviewed. Most concerned elements in this field include iodine, zinc, selenium, copper, chromium, manganese and vanadium. The minerals are powerful modulators of several physiological functions that can be considerably perturbed in deficiency states. The resulting biochemical and clinical modifications can be prevented and/or corrected by adequate supplementation. Sometimes, however, they act like pharmacological agents when their beneficial effects are not the result of a correction of a nutritional deficiency state. Their potentialities as therapeutic agents are perfectly described in many cases, but some indications deserve further investigations.

Effects of acute prednisolone administration on plasma and liver copper in rats with adjuvant arthritis

Several studies in animals and humans have shown that copper metabolism could be affected by inflammation or by corticosteroids. The relative importance of these two factors, often imbedded in clinical practice, was assessed by investigating the effects of acute prednisolone administration (30 mg/kg, ip) on healthy and adjuvant arthritis rats. Plasma copper levels were significantly higher in arthritic rats compared to healthy animals, whereas there was a slight, but nonsignificant increase in liver copper. Acute prednisolone administration in healthy rats resulted in a significant increase in plasma copper (10-15%) as early as 4 h after corticosteroid administration, which was maintained for 12 h. In arthritic rats, the response was much higher (25-40%), but somewhat delayed and shorter. Liver copper was not clearly modified by prednisolone treatment in both groups. This time-controlled study showed that acute prednisolone administration increased plasma copper in both healthy and arthritic rats, but in different ways, indicating that inflammation and corticosteroids may act synergistically.

[The nutritional importance and pharmacologic effects of cobalt and vitamin B 12 in man]

Cobalt is an unique trace element for man as it can only reveal its essential properties if provided directly as its biological active form, cobalamin or vitamin B12, the daily requirement of which is 1 to 2 micrograms in adults. This vitamin takes part in the activity of the enzyme methylmalonyl coenzyme A mutase, involved in the conversion of propionyl CoA to succinyl CoA, an intermediary product of the citrate cycle, and of the 5-methyltetrahydrofolate: homocystein methyltransferase, working in the metabolism of methionin and in DNA synthesis. Vitamin B12 deficiency is responsible for a megaloblastic anemia called pernicious anemia and for specific neurological disorders that can be corrected by adequate supplementation. Inorganic cobalt salts can therefore not be considered as essential micronutrients for man, but being able to induce polycythemia, they have a pharmacological property that was recommended in the treatment of various anemias, and they are also used in the management of cyanide poisoning.

[The nutritional importance and physiopathology of molybdenum in man]

Molybdenum is an essential trace element taking part in the active site of three human enzymes: xanthine oxidase, aldehyde oxidase and sulfite oxidase, playing a role in the detoxification of the organism and/or the production of important intermediary products. The perturbation of the first two enzymes has no established clinical consequence, but a decrease in activity of the third one is harmful for the organism, particularly the nervous system during pre- or post-natal development. The anomalies in the function of these enzymes are generally inherited and linked to the impaired production of the molybdenum cofactor, an organic molecule complexed to the element in the active site. However, several pathological cases in animals and one case in man have been clearly attributed to molybdenum deficiency. It is the reason why molybdenum supplementation has been recommended in long term total parenteral nutrition in infants and adults.

[Selenium and pregnancy]

Selenium is an essential trace element with protective properties against endogenous or exogenous aggression, mainly due to the hyperproduction of oxygen derivatives. During pregnancy, a depletion in plasma selenium occurs regulated by hormones from the placenta. Selenium requirement is simultaneously increased which is partly satisfied by the increased retention of the element resulting from a decrease in selenium urinary excretion. The foetus accumulates selenium at the end of pregnancy by storing it in the liver. However, after birth, selenium stores rapidly deplete. Selenium deficiency is apparently not responsible for pregnancy or delivery problems in man. However, the infant is exposed to pronounced deficiency symptoms or to the worsening of some diseases liable to affect the young baby, particularly if premature because the usual selenium dietary intake is marginal in this country, selenium supplementation with 25 to 50 micrograms selenium per day is advisable and should be considered among other trace elements as a food supplement for pregnant and lactating woman.

[Metabolic disorders of essential trace elements related to rheumatic disorders]

Trace elements are usually considered as "alternative" therapy. The present work is devoted to the analysis of the modifications in zinc, copper and selenium status in rheumatic diseases. The effect of the usual drug treatment is further studied as well as the therapeutic opportunities in "classic" medicine.

[Selenium and cardiovascular pathology]

Selenium deficiency has established implications in cardiovascular diseases, particularly on cardiac muscle integrity. The essential trace element takes part not only in the direct protection of endothelial cells against the accumulation of aggressive oxygen species, but also in the biosynthesis of arachidonic acid derivatives involved in platelet and leucocyte functions, or in the regulation of cholesterol. Moreover, it prevents toxic effects of cadmium and mercury, and modulates the active transport of calcium. Some clinical investigations have underlined its importance in the cardiac function and the prevention of coronary atherosclerosis, and several recent prospective epidemiological studies have attributed to selenium deficiency a greater incidence of cardiovascular diseases. Further studies should be devoted to the influence of marginal deficiency in this trace element whose optimal requirement does not seem to be met by the usual dietary intake.

Effects of chronic and acute corticosteroid therapy on zinc and copper status in rheumatoid arthritis patients

The modifications in plasma, erythrocyte and urine zinc and copper concentrations induced by chronic or acute corticotherapy were studied in patients suffering from rheumatoid arthritis and the results compared with those from controls. Patients not treated with corticosteroids had low plasma zinc and high plasma copper, which significantly correlated with inflammatory parameters (erythrocyte sedimentation rate and C-reactive protein); no change was observed in erythrocyte and urine zinc and copper. Oral long-term treatment with corticosteroids (less than 10 mg prednisolone/day) was associated with a further decrease in plasma zinc only in patients with moderate inflammation. Changes induced by such a treatment were less intense than those due to severe inflammation. The administration of intravenous high doses (1 g methylprednisolone/day) resulted in a rapid decrease in plasma zinc with a return to baseline levels two days after withdrawal. The modification was associated with a sustained increase in urine zinc and copper without changes in diuresis.

Circadian variations in plasma zinc and cortisol in man

Circadian variations of zinc and cortisol concentrations in plasma were studied in six healthy adult men. Three of them were tested over two different 24-h periods. Results were analyzed by computerizing a best-fit curve for each 24-h profile. Plasma zinc displayed a morning peak between 8.00 and 9.00 a.m. followed by an almost linear decline throughout the day with lowest values observed shortly before 6.00 p.m. A transitory increase occurred between 6.00 p.m. and 8.00 p.m. followed by a slow decrease reaching its nadir around midnight. Thereafter zinc increased steadily until 8.00 a.m. A similar profile was observed in a seventh subject who was undergoing therapeutic starvation for obesity (fifth day of the starvation period). In all subjects the time course of plasma cortisol fluctuations paralleled that of zinc. Our results confirm the existence of a circadian rhythm in plasma zinc independent of zinc intake and temporally related to the circadian rhythm of cortisol.

Selenium status in relation to clinical variables and corticosteroid treatment in rheumatoid arthritis

Plasma selenium levels, erythrocyte selenium levels and activity of the selenoenzyme glutathione peroxidase in erythrocytes were determined in patients with rheumatoid arthritis (RA) and acute inflammatory arthritis. Results were compared with those from age and sex matched controls. These variables were not statistically different from controls in patients with inflammatory arthritis and in patients with RA not treated with corticosteroids. No correlation was found in RA between plasma selenium biological variables of inflammation and most clinical indices of disease severity. Therefore, acute or chronic inflammation was not the main factor that accounted for low plasma selenium levels in RA. Corticosteroid treatment, particularly at high doses (20-60 mg prednisolone/day), was significantly related to the depressed plasma selenium levels of some patients with RA. The mechanisms underlying this modification remain poorly understood.

Plasma and erythrocyte zinc, copper and selenium in cystic fibrosis

Plasma and erythrocyte zinc, copper and selenium were measured in 20 cystic fibrosis children, aged 7 to 19 years. Mean plasma zinc and copper levels were not different from those in age-matched controls but very low zinc levels occurred sporadically. Plasma zinc concentrations were significantly lower in patients with moderate-to-severe growth retardation and with severe pulmonary disease as compared to patients without growth failure and with moderate pulmonary disease. Mean erythrocyte zinc (40.8 micrograms/g Hb +/- 9.2) and copper levels (3.56 micrograms/g Hb +/- 0.50) were very significantly increased (30.4 micrograms/g Hb +/- 5.2 and 2.73 micrograms/g Hb +/- 0.30 respectively, for age-matched controls). Mean plasma and erythrocyte selenium levels (63 ng/ml +/- 15 and 329 ng/g Hb +/- 86) were significantly lower than those in age-matched controls (82 ng/ml +/- 13 and 404 ng/g Hb +/- 116). The trace element concentrations in erythrocytes are discussed in relation to the activities of the copper- and zinc-containing enzyme superoxide dismutase and the seleno-enzyme glutathione peroxidase. We consider that more data on trace element metabolism in CF should be collected before specific supplementation is considered.

Protein-energy malnutrition and anemia in Kivu

Protein-energy malnutrition in Kivu is associated with a discrete normocytic, normochromic anemia. An attempt to define the physiopathology of this anemia disclosed the following results. As compared with local controls, both iron and total iron binding capacity were low, but with siderophilin saturation and sideroblast counts either normal or elevated; serum and erythrocyte folate was normal, plasma vitamin B12 was normal or elevated, and serum ascorbic acid was normal or elevated. The riboflavin nutritional status was normal. During refeeding, iron and riboflavin deficiencies became apparent. Characteristic findings on admission were the presence of giant erythroblasts and a diminished erythrocyte survival time implicated to an intracorpuscular hemolysis. Two results from the present study could contribute to explanation for the aforementioned abnormalities: low plasma vitamin E levels and, perhaps more importantly, low plasma selenium levels. In conclusion, the anemia of protein-energy malnutrition, as observed in Kivu, is a classifiable nonadaptive anemia that cannot be explained by isolated iron or vitamin deficiencies and whose physiopathology is distinct from that of the anemia of chronic disorders. It is suggested that a selenium deficiency may play an important role in the pathogenesis of this anemia.