Biomedical subjects

G Maiani

Publications and source records attributed to G Maiani.

At least 37 records · Page 2Linked to original sources

PubMed1995

Thyroid homeostasis and retinol circulating complex relationships in a severe iodine-deficient area of Senegal.

In adult subjects living in a severely iodine-deficient area (median urinary iodine 10 microgram/L), we evaluated the biochemical parameters of protein malnutrition in relation to thyroid homeostasis. Serum transthyretine (TTR), retinol binding protein (RBP) and retinol, all components of the retinol circulating complex (RCC), as well as ceruloplasmin levels, were determined in 63 subjects (44 F/19 M). These comprised 21 controls, 31 who were euthyroid with goiter WHO stage 2 or 3 and 11 who met the criteria of hypothyroidism (i.e. FT4 < 8 pmol/L and TSH > 4.13 mU/L) with goiter stage no more than 1b. No differences in the values of TTR and RBP were found between males and females, whereas the retinol values were slightly higher in males. The mean retinol binding protein values were lower than the normal range in all three groups but were significantly lower (p < 0.01; < 0.05) in hypothyroid subjects than in the other two groups. All hypothyroid subjects exhibited reduced retinol binding protein levels and 1/3 of them showed a marked decrease. The circulating levels of transthyretine were also lower than the normal range for western countries. 45% of the hypothyroid, 26% of goitrous and 9% of control subjects exhibited a transthyretine lower than 12 mg/dl, but the mean values were not dissimilar. The mean retinol values were within the normal range in all three groups but were lower in hypothyroid as compared to the controls (< 0.01). The resulting retinol/RBP ratio was over 1 in both the whole sample and in the subgroups. Ceruloplasmin levels were in the normal range in all groups. The data indicated that hypothyroid subjects had reduced retinol binding protein and retinol circulating complex network compared to euthyroid subjects.

Adult↗

PubMed1995

A fluorescence-based method for measuring total plasma antioxidant capability.

The Total Radical-Trapping Antioxidant Parameter (TRAP) of 10 freshly prepared human plasmas was measured by a new fluorometric assay. In this method, the rate of peroxidation induced by 2,2'-diazobis (2-amidinopropane) dihydrochloride (ABAP) was monitored through the loss of fluorescence of the protein R-Phycoerythrin (R-PE). The lag-phase induced by plasma was compared to that induced by 6-hydroxy-2,5,7,8-tetramethylchroman-2- carboxylic acid (Trolox, a water-soluble analogue of vitamin E). Proteins (but not their sulphydryl groups) interfere with the analysis, partially protecting R-PE when all plasma antioxidants are exhausted. A Trolox-induced lag-phase must therefore be measured on each plasma sample. We found that ascorbate (2.5-5.3%), alpha-tocopherol (2.9-8.5%), urate (19.6-61.0), and thiol groups (17.3-42.3%) jointly explain up to 70% of TRAP. Thus, either other compounds present in plasma are likely to exert antioxidant action, or a marked synergistic action between antioxidants should be postulated to exist. This latter hypothesis is supported by the finding that the simultaneous inactivation of ascorbate and thiol groups produces a loss in antioxidant capacity of plasma greater (26%) than the sum of the decreases produced by the separate inactivation of each of the two compounds. The proposed method appears simple, reliable, and allows the rapid handling of a reasonable number of freshly prepared plasma samples. Given the rapid loss of TRAP upon storage, the latter characteristic is crucial in studies on humans, involving a large number of subjects.

Adult↗

PubMed1995

Accumulation of beta-carotene in normal colorectal mucosa and colonic neoplastic lesions in humans.

The quantity of beta-carotene (BC) accumulated in colonic polyps and colonic cancerous tissue in humans in situ was determined relative to the quantity accumulated in normal colon and rectal tissue. Serum concentration of BC, retinol, and alpha-tocopherol and tissue BC concentration were determined by high-performance liquid chromatography in samples obtained before and after oral supplementation with BC (30 mg/day). The serum BC and retinol concentrations significantly increased in response to supplementation in control, polyp, and cancer patients, but there was no change in serum alpha-tocopherol concentration. The BC concentration in tissue (colon, rectum, and tumor) of cancer patients was significantly less than that in tissue samples from control and polyp patients. Relative to baseline values, BC accumulated to a significant extent in tissues from all patients, including polyp and tumor tissue, during supplementation. The results indicate that BC does accumulate in colonic neoplastic tissue in humans and may potentially be utilized to augment cytotoxicity of chemotherapeutics or to prevent malignant transformation of cells.

Adenomatous Polyps↗

PubMed1994

Relationship between fat-free mass and urinary excretion of creatinine and 3-methylhistidine in adult humans.

The urinary excretion of endogenous creatinine (CRTN) and 3-methylhistidine (3-MH) has been proposed as a predictor of fat-free mass (FFM) in healthy subjects. In this study, we report the relationship between FFM, estimated by densitometry plus deuterium dilution, and daily urinary excretion of CRTN and 3-MH in a sample of 20 healthy adult subjects of both sexes. 3-MH and CRTN were measured in 2 days of urine collection, which followed 4 days of meat-free diet. Meat-free diet was maintained throughout the period of urine collection. The mean of 2 days of excretion of 3-MH was 237.7 +/- 87.3 (SD) and 138.9 +/- 31.2 mumol/day in men and women, respectively. The mean CRTN excretion was 1.51 +/- 0.22 and 0.98 +/- 0.15 g/day in men and women, respectively. CRTN excretion was found well associated with FFM (R2 = 0.89; P < 0.0001), whereas 3-MH was lightly associated with FFM (R2 = 0.33; P < 0.01). Residuals from the regression of 3-MH vs. FFM were found to be correlated with CRTN excretion and FFM (R2 = 0.57 and 0.67, respectively), suggesting that muscularity and the absolute amount of lean mass are relevant for the error in predicting FFM from 3-MH excretion. Data confirm that urinary CRTN excretion can be an expedient indirect method for evaluating body composition in healthy adult subjects. Data also suggest that the relationship between 3-MH and FFM is complex, limiting the possibility of predicting body composition from the excretion of this metabolite.

Adult↗

PubMed1993

Vitamin A.

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Humans↗

PubMed1993

Vitamin C.

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Ascorbic Acid↗

PubMed1992

Salicylate hydroxylation as an early marker of in vivo oxidative stress in diabetic patients.

In vivo metabolism of salicylic acid produces two main hydroxylated derivatives (2,5- and 2,3-dihydroxybenzoic acid). The former can be produced by enzymatic pathways through the cytochrome P-450 system, while the latter is reported to be solely formed by direct hydroxyl radical attack. Therefore, measurement of 2,3-dihydroxybenzoate, following oral administration of salicylate in its acetylated form (aspirin), has been proposed for assessment of oxidative stress. In this article we report plasma levels of 2,3- and 2,5-dihydroxybenzoates following the administration of 1 g aspirin and plasma levels of thiobarbituric acid-reactive material (TBARM) in well-controlled diabetic patients and in healthy subjects. 2,3-Dihydroxybenzoate levels were significantly higher (23%) in diabetic patients than in controls (63.4 +/- 20.1 versus 49.0 +/- 6.8 nM; p < .05). On the other hand, TBARM values were not significantly different between groups. These results suggest that the method is useful to reveal in vivo oxidative stress independently from the peroxidation of lipids, and they support the hypothesis that oxygen radicals are involved in the pathogenesis of chronic complications of diabetes.

Adult↗

PubMed1989

Beta-carotene serum response in young and elderly females.

This study was designed to investigate the effects of aging and food intake on the serum beta-carotene (BC) response curve in humans. Ten elderly (71 +/- 4 years) and 17 young (28 +/- 7 years) healthy females were given 15 mg BC with a semi-solid test meal devoid of BC and vitamin A. All the elderly and 10 young subjects (control A) received a test meal of 500 kcal while the remaining 7 young subjects (control B) were given 700 kcal. Subsequently, blood was drawn hourly for 8 h and again at 24 and 48 h. Serum carotenoids and retinoids were measured by HPLC and triglycerides (TG) and cholesterol by enzymatic methods. Small intestinal transit time was determined in the elderly and in control group A by a breath hydrogen test following ingestion of lactulose (12 g) with the test meal. The area under the absorption curve (AUC) of serum BC over the first 8 h was higher in the elderly subjects than in either control group A or B (P less than 0.001). The slopes of the BC and TG curves were significantly higher as compared to control A, but similar to control B. There was a positive correlation between the ascending slopes of the BC and TG absorption curves of all groups (P less than 0.001). The AUC of the retinyl ester serum response of the elderly group was greater than that of control A (P less than 0.001). The slope of this curve was steeper (P less than 0.01) in the elderly group as compared to control A, but was similar to control B. Intestinal transit time was similar in all groups. In young subjects, the larger test meal of control group B appeared to increase the rate of absorption of BC. These data indicate that the rate of intact BC absorption and its conversion to retinyl esters may be enhanced in old age as compared to younger subjects receiving the same amount of food. Age-related alterations of enterocytes and the intestinal lumen could account for this phenomenon.

Administration, Oral↗

PubMed1989

Psychosocial responses to disease stimuli: preliminary findings.

In the present study cognitive-verbal differences are evaluated in chronic obstructive lung disease (COLD) patients. Nineteen subjects with chronic respiratory failure (CRF) and sixty subjects without CRF completed two psychometric instruments: CBA-2.0 primary scales and the respiratory illness opinion survey. The results show that social and psychological problems are connected to the severity of illness.

Adaptation, Psychological↗

PubMed1988

Habitual alcohol consumption and nutritional status of the elderly.

The interrelationship between habitual alcohol consumption, dietary intakes and vitamin status was examined in 393 elderly subjects (188 men, 205 women, age range 65-90 years) resident in seven retirement homes throughout Italy. Individual food intake was assessed by the 7-day precise weighing method. Fasting blood was tested for riboflavin (erythrocyte glutathione reductase activity coefficient), thiamine (erythrocyte transketolase activity), retinol (fluorimetry) and folic acid status. Alcohol contributed on average 12 per cent of total energy intake in men, and 6 per cent in women. Forty-eight per cent of males and 39 per cent of females were classified as heavy drinkers (HD) with 48 and 28 g/d average alcohol intakes respectively. There was a general tendency for women to add alcohol to their habitual diet, as revealed by the positive correlation between total energy intake and alcohol intake. The higher energy intakes of HD women were also reflected in their higher body weights. Men tended to displace food energy partially by alcohol. Dietary risk of malnutrition, high for vitamin A, and moderate to low for vitamins B1 and B2, did not increase with alcohol consumption. Biochemical evidence of malnutrition indicated a significant deterioration of folate status in HD of both sexes, and for B1 in HD males only; there was no change in riboflavin status. Plasma levels of retinol were higher, and prevalence of vitamin A deficiency lower, in HD, a finding that warrants further investigation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1984

Vitamin E status in Italian children subsisting on a Mediterranean diet.

Serum vitamin E levels and food intake of 83 Italian children subsisting on a 'Mediterranean-type' diet were measured. Total fat intake was 66 g/d and polyunsaturated fatty acids (PUFA) intake was 7.6 g/d. The dietary ratio of polyunsaturated to saturated fatty acids (P/S) was 0.30. Vitamin E intake was estimated to be about 4.5 mg/d and the theoretical requirement, calculated on the basis of their PUFA intake was 4.6 mg/d. The mean serum concentration of vitamin E was found to be 1.02 mg/dl which is similar or higher than reported by others. No correlation was found between serum level of vitamin E and total or HDL cholesterol, while a slightly significant correlation was found between PUFA intake and serum vitamin E. We conclude that the Mediterranean type of diet, characterized by a relatively low P/S ratio and PUFA content, provides a satisfactory vitamin E status.

Body Height↗

PubMed1983

[Determination of glutathione reductase activity in erythrocytes and whole blood as an indicator of riboflavin nutrition].

Recent developments in riboflavin statis assessment suggest the possibility of satisfactory replacement of the method based on the determination of glutathione reductase (GRe) (EC 1, 6, 4, 2) activity in erythrocytes by one on whole blood. The advantages would be the elimination of the steps of separation and washing of the erythrocytes, which may be of problematic execution under the difficult logistic conditions of field studies. In order to verify the interchangeability of the two methods, we have undertaken a comparison of the results obtained on 81 subjects. Our data show that the results of the whole blood method closely replicate those obtained on the erythrocytes and that all cases are correctly classified in terms of riboflavin status assessment. A linear regression analysis shows that the two methods overlap perfectly, with a highly significant (P less than 1%) correlation coefficient (r = 0.82). Sixty five percent of the variance of the dependent variable (CA GRsi) is accounted for by the variation of the independent variable CA GRe).

Adult↗

PubMed1982

Riboflavin status among rural children in Southern Italy.

A sample of 107 boys aged 7-10 in a rural area of Southern Italy was studied for riboflavin deficiency and its association with milk consumption. The boys represented 74 per cent of the total male population of that age group in the study area. The nutritional status was assessed by means of anthropometric indicators, dietary intakes by a 24-h recall method and the riboflavin status was evaluated by the assay of erythrocyte glutathione reductase activity. The nutritional status was found to be generally satisfactory with about one tenth of the children presenting stunting, wasting, or obesity. This picture is comparable to that recorded at the national level. The overall incidence of biochemical riboflavin deficiency was 13 per cent. No clinical sign of riboflavin deficiency was observed. None of the anthropometric indicators of malnutrition appeared to be related to biochemical evidence of riboflavin malnutrition. Dietary data showed that the children consumed a relatively small amount of milk and dairy products (mean 224 +/- 109 g/d). Thirteen out of 14 children with biochemical evidence of riboflavin deficiency belonged to the group who consumed less than 300 g/d of milk. However, only 15 per cent of the children consuming less than 300 g/d of milk and dairy products had biochemical evidence of riboflavin deficiency. It appears that the dietary pattern in rural areas with traditionally low milk consumption is compatible with a relatively satisfactory riboflavin nutriture. This finding suggests that milk and dairy products may occupy, under different dietary practices, a role less critical than usually attributed.

Animals↗

PubMed1981

[Evolution of psychological pattern during rehabilitation in a group of patients with recent myocardial infarction (author's transl)].

The aim of this study was to verify the evolution of the psychological characteristics of a group of patients with recent myocardial infarction, during a supervised physical training procedure. The study group consisted of 70 males, aged from 35 to 65 (mean 50 +/- 9). Every patient underwent a psychometric test battery before and after his rehabilitation program. The following tests were used: - Minnesota Multiphasic Personality Inventory - 16 Personality Factors Inventory - IPAT Anxiety Scale - Eysenck Personality Inventory. No patient had psychotherapic nor pharmacological treatment. Comparing the test results before and after training, a significant reduction of deviances from normal patterns was found. A clear trend towards normal values of both high and low scores was found after rehabilitation. Our data are in agreement with the concept that a supervised physical training program is able to promote psychological benefits in patients with recent myocardial infarction. These benefits can be summarized both in stronger emotional stability and in better adaptative capability. This makes their return to normal life easier.

Adult↗

PubMedDate not supplied

Determinants of nutritional status in hospital patients in Italy.

The prevalence of protein-calorie malnutrition (PCM) and micronutrient deficiency (MND) at the time of admission and discharge from hospital was evaluated in 91 patients consecutively admitted to the Surgery Clinic of the University Hospital of Rome. Anthropometric parameters and circulating levels of vitamins (A, E, C, B1, and B2) and visceral proteins [retinol-binding protein (RBP, prealbumin (PA), and transferrin] were measured. Twenty-one patients (23%) had moderate to severe PCM, and 70 patients (77%) had normal nutritional status (NNS) at admission. Two patients with PCM died in the hospital. At discharge, the prevalence of PCM was unchanged in the remaining 19 patients. Single or multiple MND was observed initially in 71% of patients with PCM and in 36% with apparently normal nutritional status. Despite vitamin supplementation, MND was present at the time of discharge in 73% of patients with PCM and 44% with NNS. Nutritional status at the time of admission was assessed in hospitals in six different Italian cities. The criterion for admission to the study was the diagnosis of chronic (greater than 1 yr duration) illness (excluding cancer and multiple organ disorders). Two hundred eighty-four patients (145 males, 139 females), ages 25-88 yr, were selected. The findings indicated a high prevalence of MND (64%). Also, in disorders that usually do not have significant alterations of digestion or absorption, such as uncomplicated cardiorespiratory disease, the prevalence of MND was high (9-38%). The prevalence of MND was not related to body mass index (BMI). PCM was more common among patients with chronic gastrointestinal disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Antioxidant agents and colorectal carcinogenesis: role of beta-carotene, vitamin E and vitamin C.

In consideration of findings reported in the literature and of our study, we examined the correlation between antioxidants (beta-carotene, vitamin C, vitamin E) and colorectal carcinogenesis. Although diagnostic progress has been made in the last decades, no significant improvements in death rates have been achieved in the western world. Exogenous factors might be responsible for a complex alteration process of might be responsible for a complex alteration process of normal colonic mucosa into adenoma and carcinoma. Free radicals and reactive oxygen metabolites, due to increased production or to reduced inactivation, following a decrease in the antioxidant burden in the mucosa, might cause damage to DNA, thereby resulting in genetic alterations. This might represent the cause of the transformation process: normal mucosa --> adenoma --> carcinoma. In a prospective study, we observed a reduction of beta-carotene levels in normal colonic mucosa in patients with polyps and colorectal cancer. We also showed that beta-carotene supplementation raises levels of this micronutrient in the colonic mucosa of these patients. Findings from the literature and our trials show a significant decrease in the antioxidant capacity of colorectal mucosa in patients affected by colorectal cancer, although there is a significant interindividual variability. Such results suggest a possible chemopreventive role of antioxidant agents in colorectal cancer.

Animals↗

PubMedDate not supplied

Pattern of thyroid hormones in mildly protein-deficient women in area endemic for goiter.

This study refers to 23 nonpregnant and 5 pregnant Ethiopian women living in a severely iodine-deficient area exposed to marginal chronic protein malnutrition. About half the study group exhibited goiter. The components of retinol circulating complex have been measured: transthyretin, retinol, and retinol-binding protein were 31 +/- 8 mg/dl, 36 +/- 6 micrograms/dl, and 3.1 +/- 0.6 mg/dl, respectively. No differences in circulating thyroid hormone pattern were found among goitrous and nongoitrous subjects. In nonpregnant women, the circulating thyroid hormone pattern was characterized by a low total T4 (TT4, 53 ng/ml), whereas free T4 (FT4, 0.5 ng/dl) was below the lower level of the range. Thyroid-stimulating hormone and FT3 were in the normal range, and TT3 was at the upper level of the range. The pregnant women exhibited the expected increase in total thyroid hormones (TT3 3.0 ng/ml, TT4 96 ng/ml), whereas the free fractions were equal to those of the nonpregnant subjects (FT3 2.5 pg/ml, FT4 0.6 ng/dl). In the whole group, the T3-T4 ratio was 3.4 x 10(-2), i.e., twice the normal ratio. No antibodies against thyroid structures were detected. These results indicate that the circulating thyroid hormone pattern of these marginally malnourished women differs from that reported for subjects with pure protein-calorie malnutrition or exposed to chronic iodine deficiency only. The main difference is that, even in the presence of low TT4 and FT4, the hypophysis-thyroid axis has apparently remained unchanged. The normal levels of TT3 and FT3, may account for the normal thyroid-hypophysis feedback.

Adult↗

PubMedDate not supplied

Use of PABA test to check completeness of 24-h urine collections in elderly subjects.

The p-aminobenzoic acid (PABA) test has been successfully used as an indicator of completeness of 24-h urine collection in field studies of the general population. Our study was designed to investigate its validity for elderly people. Urinary excretion of fractionated oral doses of PABA was measured in 21 young control subjects (19-39 yr old) and 356 elderly (60-89 yr old) men and women. PABA excretion over 24 h was lower in elderly than in control subjects. Subjects aged greater than or equal to 70 yr had a lower recovery of the PABA dose than subjects aged 60-69 yr over the first 24 h, followed by a higher recovery over the next 24-48 h. The cumulative 48-h recovery was similar in all age classes of elderly subjects. However, 48% of the elderly subjects had a cumulative PABA recovery below the conventional cutoff for completeness (85%). These subjects also had consistently lower creatinine output and urinary volume. The lower 24-h urinary PABA recovery over 70 yr of age is interpreted to reflect the delayed renal clearance of the marker substance and indicates that the PABA test is unsuitable for this age group. The low 48-h cumulative recoveries found in all age classes of the elderly are thought to be caused by small unreported losses, which are recurrent in free-living populations.

4-Aminobenzoic Acid↗