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P Preziosi

Publications and source records attributed to P Preziosi.

At least 127 records · Page 7Linked to original sources
PubMed1994

Iron status of a healthy French population: factors determining biochemical markers.

The iron status of a representative population sample in a district of Paris area (France) was assessed using a biochemical and dietary approach. Complete data were obtained for 1,108 subjects 6 months to 97 years old. Total iron intake increased up to adolescence and then remained stable in adult life. Iron intake was higher in men than in women. Most children and menstruating women presented a dietary iron intake below the recommended allowances. While anemia was not very common, iron deficiency (defined as the existence of at least two abnormal values in the four independent indicators of iron status: serum ferritin, erythrocyte protoporphyrin, transferrin saturation and MCV) was particularly common in infants, young children, menstruating women and elderly men. Serum ferritin, erythrocyte protoporphyrin and transferrin saturation were significantly correlated with inflammatory markers. Significant correlations were found between dietary total iron and serum ferritin (r = 0.29, p < 0.001) and hemoglobin (r = 0.44, p < 0.001). After adjustment for age, sex and inflammation, using multiple linear regression models, the relationship between both heme and nonheme iron intake and serum ferritin remained significant. Serum ferritin and hemoglobin levels were negatively correlated with calcium and phosphorus intake.

Adolescent↗
PubMed1994

Carbon monoxide as a novel neuroendocrine modulator: inhibition of stimulated corticotropin-releasing hormone release from acute rat hypothalamic explants.

Although recent evidence suggests that the gas nitric oxide (NO) can modulate the secretion of corticotropin-releasing hormone (CRH) from acute rat hypothalamic explants, another gas, carbon monoxide (CO), has been suggested to play a role in neural signaling in the brain; CO may complement the activity of NO in long term potentiation. In this study, we have investigated whether CO shares with NO the ability to modify the release of CRH from the rat hypothalamus. Hemin, a specific CO precursor through the enzyme heme oxygenase (the enzymatic pathway synthesizing endogenous CO), was found to inhibit in a dose-dependent manner KCl-stimulated CRH release, with a maximal effect at 1 microM, while showing no effect on basal CRH secretion. The stimulation of CRH by interleukin-1 beta (100 ng/ml) was also significantly antagonized by hemin (1 microM). An inhibitor of heme oxygenase, zinc-protoporphyrin-9, had no effect on basal or stimulated CRH release up to a maximal dose of 10 microM. When hemin and zinc-protoporphyrin-9 were given together, the hemin-induced inhibition of CRH release was completely antagonized by the enzyme inhibitor. These findings provide evidence that endogenous CO may play a role in the control of CRH release; by analogy with NO, CO may represent a major new neuroendocrine modulator.

Animals↗
PubMed1994

Lipopolysaccharide modulation of eicosanoid and corticotrophin-releasing hormone release from rat hypothalamic explants and astrocyte cultures in vitro: evidence for the involvement of prostaglandin E2 but not prostaglandin F2 alpha and lack of effect of nerve growth factor.

Bacterial lipopolysaccharide (LPS) and prostaglandins (PG) E2 and F2 alpha are putative activators of the hypothalamo-pituitary-adrenal axis. Certain of the biological effects of LPS may be mediated by cytokines such as interleukin-1 beta (IL-1 beta), while IL-1 beta itself may operate via induction of the prostaglandins and/or nerve growth factor (NGF). As IL-1 beta stimulates the release of corticotrophin-releasing hormone (CRH) from acute rat hypothalamic explants directly, the effects of these substances on the release of CRH in vitro were investigated in short- and medium-term (20 and 60 min) incubations. The effect of LPS on the release of PGE2 and PGF2 alpha from these explants, as well as from cortical astrocyte cultures, was also studied. LPS did not modify the release of CRH, PGE2 or PGF2 alpha in 20-min incubations. In 60-min incubations, LPS stimulated the release of PGE2, whereas the release of CRH was weakly, but significantly, reduced; PGF2 alpha was not altered. PGE2 significantly stimulated CRH release in the 60-min but not in the 20-min experiments. This effect appeared to be selective for PGE2, since PGF2 alpha did not modify CRH release, alone or in combination. LPS also selectively released PGE2 but not PGF2 alpha from cortical astrocyte cultures after 24-h incubation. NGF had no effect on the release of explant CRH, regardless of the length of incubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Vitamin status of a healthy French population: dietary intakes and biochemical markers.

The vitamin status of a representative population sample in a French district in the Paris area was assessed using a biochemical and dietary approach. Complete data were obtained for 1039 subjects 6 to 97 years old. Dietary intakes of most vitamins increased up to adolescence and then remained stable or decreased slightly in adult life. Total vitamin intakes were higher in men than in women (except for ascorbic acid), but the vitamin density of the diet was higher in females. Most subjects presented dietary intakes below the French recommended allowances for vitamin B1, B6, C, A and E. A variation in biochemical parameters according to age and sex was observed only for serum concentration of retinol, beta-carotene, vitamin E and C. Multiple regression analysis showed that dietary vitamin intakes were related to the biological status for vitamin B2, B6, C, folates, beta-carotene and vitamin E. Tobacco smoking, alcohol consumption and oral contraceptive were significantly correlated with biological status for several vitamins. While biochemical evidence of severe vitamin deficiency was not observed, a sizeable minority of the French population is not lavishly supplied with some vitamins, and this situation deserves investigation to see if any deleterious effects are associated with it.

Adolescent↗
PubMed1994

Serum trace elements in Zairian mothers and their newborns.

OBJECTIVES: Pregnant women in developing countries might be at risk of trace element deficiencies. These deficiencies could have deleterious effects on fetus. Therefore, serum trace elements were determined at delivery in Zairian mothers and their newborns. DESIGN: Prospective study. SETTING: Maternity ward of Kinshasa University Hospital (Zaire). SUBJECTS: 166 pregnant women admitted for delivery and their newborns. MAIN OUTCOME MEASURES: Zinc, copper and selenium were determined by atomic absorption spectrometry. Haematocrit, lymphocyte count, transferrin, ferritin and anthropometric indices (birth weight, length, head and arm circumferences; mother weight) were also evaluated. RESULTS: Serum selenium concentrations were high [mothers: 0.76-1.56 mumol/l (60-124 micrograms/l), newborns: 0.45-1.21 mumol/l (36-96 micrograms/l)]; zinc concentrations were low [mothers: 3.9-11.9 mumol/l (253-773 micrograms/l), newborns: 5.8-17.4 mumol/l (378-1130 micrograms/l)] and copper concentrations were in the range of previous works [mothers: 16.2-49.0 mumol/l (1020-3088 micrograms/l), newborns: 0.7-14.3 mumol/l (44-900 micrograms/l)]. Mother serum indices, age, weight and parity had little influence on newborn serum trace elements. In umbilical serum, copper was correlated to selenium (r = 0.340, P < 0.01); selenium (r = 0.310, P < 0.001) and copper (r = 0.404, P < 0.001) were correlated to transferrin. Newborn selenium (r = 0.310, P < 0.001) and copper (r = 0.257, P < 0.01) concentrations were related to head circumference. Newborn selenium concentration varied according to birth weight [< 2500 g: 0.58-0.86 mumol/l (45-67 micrograms/l); > 2500 g: 0.48-1.20 mumol/l (37-94 micrograms/l). Umbilical serum copper concentration was related to birth length (r = 0.197, P < 0.05). CONCLUSIONS: These results suggest that: (1) copper and selenium status at delivery in Zairian mothers are similar to those in developed countries, whereas zinc status is poor; (2) trace element and nutritional status in the mother and fetus are independent.

Adolescent↗
PubMed1994

Relationship between urinary iodine concentration and hearing capacity in children.

Urinary iodine excretion was assessed in 1222 healthy children aged 10 months (n = 456), 2 years (n = 368) and 4 years (n = 398) living in the Paris area and originating from continental France (55.2%), North Africa (15.7%), the West Indies (9.7%), West Africa (8.2%), Southeast Asia (5.5%), and southern Europe (5.7%). Iodine excretions (median values) were, respectively, 18.1, 13.4 and 11.6 micrograms/100 ml at 10 months, 2 years and 4 years, and risk of mild to moderate iodine deficiency (< 10 micrograms/100 ml) was 18.0%, 32.3% and 37.2% for the same age groups. Urinary iodine excretion was highest among Southeast Asian children, and lowest among West Africans. Hearing acuity was measured either by conventional mono-aural pure-tone audiometry or by binaural free field testing depending on the child's age. Hearing loss at 4000 Hz and average hearing impairment at speech frequencies (500, 1000 and 2000 Hz) were more severe among children at risk of mild to moderate iodine deficiency (less than 10 micrograms/100 ml) compared with those with urinary excretion above 10 micrograms/100 ml.

Anthropometry↗
PubMed1993

Interleukin-1 alpha and tumour necrosis factor inhibit rat gastric fundus motility in vitro.

In this study, the effects of tumour necrosis factor (TNF) and interleukins 1 alpha and 6 (IL-1 alpha and IL-6) on rat gastric fundus motility were investigated in vitro. IL-1 alpha and TNF induced rapid dose-dependent inhibition of stomach motility, with maximal relaxation equal to that induced by 100 microM papaverin, and respective EC50s of 20 and 450 pg/ml. IL-6 had no effect on gastric motility up to a 3 ng/ml concentration.

Animals↗
PubMed1993

The immune response in iron-deficient young children: effect of iron supplementation on cell-mediated immunity.

The effects of iron deficiency on immunity remain controversial. This study was designed to assess the impact of iron supplementation on the immune status, in 81 children aged 6 months-3 years, at high risk for iron deficiency, using a longitudinal double blind randomised and placebo-controlled study. Lymphocytes of iron-deficient children produced less interleukin-2 in vitro. Iron supplementation for 2 months increased mean corpuscular volume, serum ferritin and serum transferrin, but had no effect on the parameters of T-cell mediated immunity. The lower interleukin-2 levels in iron-deficient suggest that cell-mediated immunity may be impaired in iron deficiency.

Anemia, Hypochromic↗
PubMed1993

Effects of vasoactive intestinal polypeptide on antigen-induced bronchoconstriction and thromboxane release in guinea-pig lung.

1. Exogenous vasoactive intestinal polypeptide (VIP) infused into the pulmonary artery of isolated and ventilated lungs of guinea-pigs decreased, in a dose-dependent fashion (1.0-10.0 nmol), airway resistance and thromboxane B2 (TXB2, the stable hydrolysis product of TXA2) release in the perfusion medium. Prostacyclin (PGI2) synthesis, as reflected by the release of its stable hydrolysis product 6-oxo-PGF1 alpha, was unaffected. Pretreatment with the 5-lipoxygenase inhibitor BWA4c (3.5 x 10(-5) M) did not modify the bronchodilatory effect of VIP or its inhibitory action on TXB2 release. 2. Basal release of immunoreactive VIP from perfused lungs decreased from an initial value of 0.96 +/- 0.10 ng min-1 (mean +/- s.e.mean) in the first 2 min to an average of 0.58 +/- 0.10 ng min-1 in the following 15-20 min. 3. Antigen challenge with ovalbumin (0.1%) in sensitized lungs caused an anaphylactic reaction in 45% of tested lungs, concomitant with a 5 fold increase in both VIP and TXB2 release. Tetrodotoxin pretreatment (10(-6) M) reduced basal VIP release by > 80% and abolished the VIP increase observed during anaphylaxis, without modifying TXB2 release or the bronchoconstrictor response. 4. Indomethacin (10(-6) M) inhibited TXB2 synthesis and release by > 90%, delayed the bronchoconstrictor response and blunted the increased VIP release during lung anaphylaxis, without influencing basal VIP release. 5. The 5-lipoxygenase inhibitor BWA4c (3.5 x 10(-5) M) blunted the increase of TXB2 and VIP release from guinea-pig lung and attenuated the bronchoconstrictor response following ovalbumin challenge. 6. The administration of exogenous VIP as a continuous infusion (10-8 M) attenuated the bronchoconstriction and the release of cyclo-oxygenase metabolites following antigen challenge.7. Acetylcholine (10-6-l0-5 M) infused into the pulmonary artery induced a dose-dependent bronchoconstriction not associated with enhanced VIP or TXB2 release.8. The TXA2 mimetic U-46619 (0.1-1.0 nmol) caused dose-dependent increases in airway resistance,concomitant with an up to 10 fold increase in VIP release. VIP inhibited arachidonate-induced in vitro aggregation of washed rabbit platelets in a dose-dependent manner over a dose range 10-8 10-6 M.Despite the antiaggregatory effect of VIP, TXB2 and PGE2 synthesis was reduced only to a minor extent,and there was no redirection of arachidonate metabolism from TXA2 to PGE2, indicating that VIP does not act as a TX synthase inhibitor in vitro.9. We conclude that VIP may play a role in regulating bronchial smooth muscle reactivity in lung anaphylaxis by inhibiting the synthesis and release of TXA2, a potent vasoactive and bronchoconstrictor agent. TXA2, on the other hand, strongly enhances neuronal VIP release.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1993

Prostaglandin E2 and bacterial lipopolysaccharide stimulate bioactive interleukin-1 release from rat hypothalamic explants.

While interleukin-1 (IL-1) is intimately involved in locally modulating the acute inflammatory response, it is also able to influence processes at remote sites, i.e., in an endocrine manner. While there is as yet little evidence that IL-1 can cross the blood-brain barrier, many effects such as fever, increased slow-wave sleep, anorexia and the modulation of neuroendocrine function suggest an action of circulating IL-1 at regulatory sites within the hypothalamus. However, there is accumulating evidence for IL-1 originating within the central nervous system (CNS), and it is currently unclear as to whether the neurally mediated manifestations of the acute inflammatory response are due to activation of central or peripheral (circulating) IL-1. In this study we have characterized the release of IL-1 from rat hypothalamic explants, and we have investigated the effects of putative modulators of IL-1 release, lipopolysaccharide (LPS) and the prostaglandins E2 (PGE2) and F2 alpha (PGF2 alpha). After 1 h of incubation, IL-1-like activity in hypothalamic supernatants ranged between 175 and 2,304 munits/mg of protein; this was substantially inhibited by the addition to the bioassay system of antibodies (1:200) against IL-1 alpha, but not against IL-1 beta. LPS and PGE2 significantly stimulated IL-1 release at 100 and 1 ng/ml respectively, whereas PGF2 alpha had no effect in the range of doses tested. It is therefore concluded that the control of hypothalamic IL-1 release may be investigated by means of acute rat hypothalamic explants.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Effect of iron supplementation during pregnancy on trace element (Cu, Se, Zn) concentrations in serum and breast milk from Nigerian women.

Trace element concentrations in serum and breast milk were studied longitudinally in 197 Nigerian women from 6 months of gestation to 6 months postpartum; 99 of them received a daily iron supplement of 100 mg from 6 months of gestation to delivery. During the last 3 months of pregnancy, serum selenium declined, whereas serum zinc remained unchanged and serum copper increased. After delivery, copper concentration in maternal serum decreased, whereas serum zinc increased from delivery to 3 months postpartum and then reached a plateau. Serum selenium increased from delivery to 6 months postpartum. In breast milk, selenium and zinc decreased from 5 days to 6 months postpartum. Copper in breast milk also declined during the course of lactation but reached a plateau by 3 months postpartum. Iron concentration in breast milk remained unchanged during the study. Iron supplementation had no significant effect upon the concentrations of copper, selenium and zinc in mother serum and breast milk. In umbilical serum, iron status, copper and zinc levels were similar in the two groups, whereas, unexpectedly, selenium concentration was significantly decreased (p < 0.03) in the iron-supplemented group. Taken together, our results suggest that the beneficial effect of iron supplementation on iron deficiency was not associated with an adverse effect on copper and zinc status. On the other hand, our results suggest that Nigerian women had a marginal zinc status but an adequate selenium status.

Adolescent↗
PubMed1993

Interrelation between plasma sex hormone-binding globulin and plasma insulin in healthy adult women: the telecom study.

In order to study the relationship between plasma sex-hormone-binding globulin (SHBG) and insulin levels in healthy women, we investigated the association between plasma SHBG and insulin in an occupational sample of 786 nonhormone-using women. Levels of plasma SHBG showed a stepwise decrease with increasing fasting plasma insulin in premenopausal as well as in postmenopausal women. In these cross-sectional data, this significant negative relationship between SHBG and insulin was shown to be independent of age, body mass index, subscapular skinfold, fasting and 2-h plasma glucose in both groups. The etiology and the consequences of this inverse association between SHBG and insulin are unclear. Prospective and clinical studies in women will be necessary to determine the direction and causal nature of the association between SHBG and insulin, as well as its mechanism and its physiological and/or pathophysiological consequences.

Adult↗
PubMed1993

Selenium determination in human milk in Niger: influence of maternal status.

Selenium (Se) was determined in human milk from women residing in Niamey (Niger) at different periods of lactation. To this purpose, a rapid electrothermal atomic absorption spectrometric (EAAS) method using Zeeman background correction and palladium matrix modifier was developed. Linear range (10 nmol/L-6.25 mumol/L, 0.8-494 micrograms/L), within-run (7.6%), between-run (10.4%), precision and recovery of standard addition (101 +/- 7%) were sufficient to allow routine determination of Se in breast milk. Values of breast milk Se decreased from 5 days to 6 months postpartum. No significant correlation was found between the milk Se and any of the following parameters: mother serum Se, parity, age of the mother, age of the previous child. In mother serum, Se concentration increased from delivery to 3 months postpartum and remained stable afterwards. The Se concentrations found in breast milk and in mother serum suggest that Se status is adequate in Niger.

Adolescent↗
PubMed1992

The effects of 5-HT3 receptor antagonists on cisplatin-induced emesis in the pigeon.

In the present study, the emetic effect of the anticancer drug cisplatin, and the protective effects of 5-HT3 receptor antagonists against cisplatin emesis were investigated in the pigeon. The experimental set-up involved the i.v. administration of drugs and subsequent observation of the percentage of vomiting animals and the number of emetic episodes per vomiting animal. It was observed that cisplatin induced dose-dependent emesis in the pigeon. 5-HT3 receptor antagonists afforded partial protection against cisplatin emesis, although some of them, i.e. indole, indole-like derivatives and zacopride, displayed intrinsic emetic activity. A serotonergic mechanism appears to be involved in both cisplatin- and 5-HT3 receptor antagonist-induced emesis, since pretreatment with an inhibitor of 5-HT synthesis, para-chlorophenylalanine (pCPA), prevented vomiting induced by either cisplatin or 5-HT3 receptor antagonists. It is concluded that the intrinsic emetic effects of 5-HT3 receptor antagonists provide pharmacological evidence of species differences in the properties of 5-HT3 receptors.

Animals↗
PubMed1992

The influence of aging on plasma sex hormones in men: the Telecom Study.

From April 1985 to July 1987, 1,408 healthy white men aged 20-60 years in Paris, France, recruited on an occupational basis, underwent a physical examination and measurements of plasma sex hormones in a cross-sectional study. Both total testosterone and estradiol showed a significant stepwise decrease with age (p less than 0.001) starting in the early adult years, while estrone did not vary. These relations of testosterone and estradiol with age remained significant after adjustment for body mass index, subscapular skinfold, and tobacco and alcohol consumptions, and they were not modified by exclusion of the men who reported chronic disease. Both the mechanism for the early decrease in testosterone and its clinical significance merit further investigation.

Adult↗