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Biomedical subjects

Y Lin

Publications and source records attributed to Y Lin.

At least 271 records · Page 15Linked to original sources
PubMed1999

'Proteolytic switching': opposite patterns of regulation of gelatinase B and its inhibitor TIMP-1 during human melanoma progression and consequences of gelatinase B overexpression.

Although it is generally accepted that proteolytic degradation is an important mechanism used by malignant cells in the process of metastasis, comparatively little is known about the regulation of molecules responsible for proteolysis and how they become de-regulated during human tumour progression. Using a genetically related pair of human melanoma cell lines, derived from the same patient at different stages of disease, we analysed differences in the cytokine-mediated regulation of gelatinase B (MMP-9), an enzyme thought to play an important role in cellular invasiveness, and TIMP-1, a physiological inhibitor of this enzyme. Whereas the advanced stage (i.e. metastatic) partner of this pair (WM 239) could produce gelatinase B upon induction with interleukin (IL)-1beta or tumour necrosis factor alpha (TNF-alpha), the early stage (i.e. primary) partner (WM 115) could not. In sharp contrast, we found that TIMP-1 displayed an opposite pattern of induction in these cell lines. Specifically, the early stage cell line, WM 115, demonstrated a marked increase in the production of TIMP-1 when treated with IL-1beta or TNF-alpha whereas the advanced cell line, WM 239, showed no such increase. Treatment with the DNA demethylating agent, 2-deoxy-5-azacytidine, resulted in a marked up-regulation of both gelatinase B and TIMP-1 in both cell lines. It was further found that constitutive overexpression of gelatinase B in WM 239 cells and an additional melanoma cell line (MeWo), derived from a metastatic lesion, was able to greatly enhance lung colonization in an experimental metastasis assay while we did not observe differences in tumorigenicity. From these results we conclude that an altered responsiveness of gelatinase B and TIMP-1 to induction by similar agents is associated with disease progression in human melanoma and that this altered responsiveness can have consequences to the aggressive nature of the disease.

Animals↗
PubMed1999

Is there a difference in the function of granulosa-luteal cells in patients undergoing in-vitro fertilization either with gonadotrophin-releasing hormone agonist or gonadotrophin-releasing hormone antagonist?

Gonadotrophin-releasing hormone (GnRH) regulates gonadotrophin release. It has been shown that GnRH may have a direct effect on the ovary, as the addition of GnRH to granulosa cell cultures inhibits the production of progesterone and oestradiol. Specific GnRH receptors have been found to be present in rat and human granulosa cells. Desensitization of the pituitary by GnRH agonist has become common in in-vitro fertilization (IVF) treatment, usually by a long protocol of 2-3 weeks. With the introduction of GnRH antagonists, which produce an immediate blockage of the GnRH receptors, a much shorter exposure is needed of 3-6 days. The aim of this study was to evaluate the effect of a GnRH agonist (buserelin) and a GnRH antagonist (cetrorelix) on the function of granulosa cells cultured in vitro from IVF patients. Women were treated by IVF randomized either to have buserelin nasal spray from the luteal phase in the previous cycle or cetrorelix from day 6 of the cycle. Both groups had ovarian stimulation with human menopausal gonadotrophin (HMG) 150 IU daily, i.e. HCG was administered when the follicles were larger than 17 mm, and aspirated 36 h later. Granulosa cells, separated and washed from large follicles containing ova, were pooled. After 48 h of pre-incubation, the granulosa cells were cultured for 4 days in medium with either added testosterone or cAMP with or without HCG, with change of medium after 2 days. The progesterone and oestradiol concentrations in the culture medium were measured by immunological assay, and cellular protein was measured by microprotein assay. The results showed that granulosa cells from women treated with GnRH antagonist (cetrorelix) responded earlier to the in-vitro hormone stimulation in terms of progesterone accumulation than women treated with the GnRH agonist (buserelin). This may have been due to difference in time of exposure to the analogue. The results may indicate that the luteal function is less impaired in GnRH antagonist treatment than in GnRH agonist treatment.

Administration, Inhalation↗
PubMed1999

Lysine deficiency alters diet selection without depressing food intake in rats.

Under states of protein deficiency, the dietary limiting amino acid, rather than protein content, can act as the dietary stimulus to control diet selection. If fact, threonine-deficient rats will alter their diet selection patterns solely on the basis of very small changes (0.009 g/100 g) in the dietary threonine concentration. In these studies, we assessed whether lysine-deficient rats will also alter their diet selection patterns on the basis of small changes in dietary Lys concentration. In all experiments, growing rats were adapted to diets in which the protein fraction (purified amino acids or wheat gluten) was limiting in Lys. They were then given a choice between the adaptation diet (AD) diet and a slightly more deficient diet. Rats that were adapted to a Lys-deficient diet (0.25 g Lys/100 g) selected their AD over diets containing as little as 0.01% less Lys (P < 0.01) within 5 d. To determine how deficient rats must be before they alter their selection patterns, rats were adapted to diets containing various levels of Lys, i.e., 2 levels below the requirement for growth and 2 levels above the requirement for growth, but below the requirement for maximal nitrogen retention. Only rats adapted to diets containing Lys below their requirement for growth selected their AD over a diet containing 0.05% less Lys (P < 0.005). Finally, to determine whether rats will alter their selection to whole protein-based diets, rats were adapted to 25% wheat gluten diets supplemented with 0.03-0.21% Lys. Rats selected the AD over a diet containing as little as 0.09% less supplemental Lys by d 4 of the trial (P < 0.05). We conclude that rats are sensitive to changes as small as 0.01% in dietary Lys concentration, but that sensitivity requires prior adaptation to Lys-deficient diets.

Adaptation, Physiological↗
PubMed1999

Renal dysfunction associated with the perioperative use of diclofenac.

UNLABELLED: Postoperative renal dysfunction in rats is induced by ketorolac dosed concurrently with gentamicin. Herein, we report the renal effects of diclofenac in four groups of rats: control (C = anesthesia, surgery); diclofenac (D = anesthesia, surgery, diclofenac 18 mg x kg(-1) x d(-1)); gentamicin (G = anesthesia, surgery, gentamicin 20 mg x kg(-1) x d(-1)); and diclofenac and gentamicin (DG = anesthesia, surgery, diclofenac, gentamicin). Renal function, after three treatment days, was assessed using histology, p-aminohippurate (PAH), and iothalamate (IOT) clearances, serum and urine electrolytes, osmolality, urea, and creatinine. Urine output was increased (from 5.2 to 12.5 mL/24 h), and urine osmolality was decreased (from 2121 to 883 mOsm/kg) in the DG group. PAH and IOT clearances were decreased in the G and DG groups (PAH by 18%, IOT by 22%; PAH by 38%, IOT by 43%, respectively); there were no changes in the C and D groups. Urea and creatinine clearances were decreased by 61% and 43%, respectively, in the DG group. Kidney sections showed the most severe pathologic changes in the DG group. Our data indicate that the perioperative combination of diclofenac and gentamicin was deleterious to renal function. IMPLICATIONS: Diclofenac alone does not result in significant perioperative renal dysfunction, but the combination of gentamicin and diclofenac is deleterious to renal function. Considering this and previous findings, the evidence suggests that treatment with aminoglycosides may be a significant risk factor for inducing perioperative renal failure during treatment with nonsteroidal antiinflammatory drugs.

Animals↗
PubMed1999

Pharmacokinetics of epsilon-aminocaproic acid in patients undergoing aortocoronary bypass surgery.

BACKGROUND: Epsilon-aminocaproic acid (EACA) is commonly infused during cardiac surgery using empiric dosing schemes. The authors developed a pharmacokinetic model for EACA elimination in surgical patients, tested whether adjustments for cardiopulmonary bypass (CPB) would improve the model, and then used the model to develop an EACA dosing schedule that would yield nearly constant EACA blood concentrations. METHODS: Consenting patients undergoing elective coronary artery surgery received one of two loading doses of EACA, 30 mg/kg (group I, n = 7) or 100 mg/kg (group II, n = 6) after CPB, or (group III) a 100 mg/kg loading dose before CPB and a 10 mg x kg(-1) x h(-1) maintenance infusion continued for 4 h during and after CPB (n = 7). Two patients with renal failure received EACA in the manner of group III. Blood concentrations of EACA, measured by high-performance liquid chromatography, were subjected to mixed-effects pharmacokinetic modeling. RESULTS: The EACA concentration data were best fit by a model with two compartments and corrections for CPB. The elimination rate constant k10 fell from 0.011 before CPB to 0.0006 during CPB, returning to 0.011 after CPB. V1 increased 3.8 l with CPB and remained at that value thereafter. Cl1 varied from 0.08 l/min before CPB to 0.007 l/min during CPB and 0.13 l/min after CPB. Cl2 increased from 0.09 l/min before CPB to 0.14 l/min during and after CPB. Two patients with renal failure demonstrated markedly reduced clearance. Using their model, the authors predict that an EACA loading infusion of 50 mg/kg given over 20 min and a maintenance infusion of 25 mg x kg(-1) x h(-1) would maintain a nearly constant target concentration of 260 microg/ml. CONCLUSIONS: EACA clearance declines and volume of distribution increases during CPB. The authors' model predicts that more stable perioperative EACA concentrations would be obtained with a smaller loading dose (50 mg/kg given over 20 min) and a more rapid maintenance infusion (25 mg x kg(-1) x h(-1)) than are typically employed.

Adolescent↗
PubMed1999

Control of pollen tube tip growth by a Rop GTPase-dependent pathway that leads to tip-localized calcium influx.

We have shown that Rop1At, a pollen-specific Rop GTPase that is a member of the Rho family of small GTP binding proteins, acts as a key molecular switch controlling tip growth in Arabidopsis pollen tubes. Pollen-specific expression of constitutively active rop1at mutants induced isotropic growth of pollen tubes. Overexpression of wild-type Arabidopsis Rop1At led to ectopic accumulation of Rop1At in the plasma membrane at the tip and caused depolarization of pollen tube growth, which was less severe than that induced by the constitutively active rop1at. These results indicate that both Rop1At signaling and polar localization are critical for controlling the site of tip growth. Dominant negative rop1at mutants or antisense rop1at RNA inhibited tube growth at 0.5 mM extracellular Ca(2+), but growth inhibition was reversed by higher extracellular Ca(2+). Injection of anti-Rop antibodies disrupted the tip-focused intracellular Ca(2+) gradient known to be crucial for tip growth. These studies provide strong evidence for a Rop GTPase-dependent tip growth pathway that couples the control of growth sites with the rate of tip growth through the regulation of tip-localized extracellular Ca(2+) influxes and formation of the tip-high intracellular Ca(2+) gradient in pollen tubes.

Arabidopsis↗
PubMed1999

A rapid non-culture-based assay for clinical monitoring of phenotypic resistance of human immunodeficiency virus type 1 to lamivudine (3TC).

Monitoring for lamivudine (3TC) resistance is important both for the clinical management of human immunodeficiency virus type 1 (HIV-1)-infected patients treated with 3TC and for surveillance of transmission of 3TC-resistant HIV-1. We developed a novel non-culture-based assay for the rapid analysis of phenotypic resistance to 3TC of HIV-1 in plasma. The assay measures the susceptibility of HIV-1 reverse transcriptase (RT) activity to 3TC triphosphate (3TC-TP) in plasma. RT detection was done by the Amp-RT assay, an ultrasensitive PCR-based RT assay. Under our assay conditions, we found that 5 microM 3TC-TP inhibited RT activity from wild-type (WT), zidovudine-resistant, or nevirapine-resistant HIV-1 but not from HIV-1 carrying either the M184V mutation or multidrug (MD) resistance mutations (77L/116Y/151M or 62V/75I/77L/116Y/151M). Mixing experiments showed a detection threshold of 10% 3TC-resistant virus (M184V) in a background of WT HIV-1. To validate the assay for the detection of phenotypic resistance of HIV-1 to 3TC in plasma samples, HIV-1 RT in 30 plasma specimens collected from 15 patients before and during therapy with 3TC was tested for evidence of phenotypic resistance by the Amp-RT assay. The results were compared with those of genotypic analysis. The RT in 12 samples was found to be 3TC sensitive, while the RT in 18 samples had evidence of phenotypic resistance. All 12 samples with 3TC-sensitive RT had WT genotypes at codon 184 and were retrieved before treatment with 3TC. In contrast, all 18 specimens with 3TC-resistant RT were posttherapy samples. This assay provides a simple, rapid, and reliable method for the detection of phenotypic resistance of HIV-1 to 3TC in plasma.

Anti-HIV Agents↗
PubMed1999

Multiple pathways for repair of DNA double-strand breaks in mammalian chromosomes.

To study repair of DNA double-strand breaks (DSBs) in mammalian chromosomes, we designed DNA substrates containing a thymidine kinase (TK) gene disrupted by the 18-bp recognition site for yeast endonuclease I-SceI. Some substrates also contained a second defective TK gene sequence to serve as a genetic donor in recombinational repair. A genomic DSB was induced by introducing endonuclease I-SceI into cells containing a stably integrated DNA substrate. DSB repair was monitored by selection for TK-positive segregants. We observed that intrachromosomal DSB repair is accomplished with nearly equal efficiencies in either the presence or absence of a homologous donor sequence. DSB repair is achieved by nonhomologous end-joining or homologous recombination, but rarely by nonconservative single-strand annealing. Repair of a chromosomal DSB by homologous recombination occurs mainly by gene conversion and appears to require a donor sequence greater than a few hundred base pairs in length. Nonhomologous end-joining events typically involve loss of very few nucleotides, and some events are associated with gene amplification at the repaired locus. Additional studies revealed that precise religation of DNA ends with no other concomitant sequence alteration is a viable mode for repair of DSBs in a mammalian genome.

Animals↗
PubMed1999

Panax quinquefolium L. inhibits thrombin-induced endothelin release in vitro.

Endothelial cell damage is considered to be the initial step in the genesis of thrombosis and arteriosclerosis, the common precursors of cardiovascular disorders. In this study, we evaluated the protective effects of American ginseng or Panax quinquefolium L. extracts on endothelial cell injury, and investigated effects of ginseng extracts on thrombin-induced endothelin release using cultured human umbilical vein endothelial cells. We observed that when endothelial cells pretreated with 1, 10, and 100 micrograms/ml of Panax quinquefolium L. extracts were incubated for 4 and 24 hr with thrombin, the concentration of endothelin was significantly decreased in a concentration dependent, time related manner (at 4 hr, IC50 = 5.1 micrograms/ml; at 24 hr, IC50 = 6.2 micrograms/ml). We further evaluated the effects of NG-nitro-L-arginine (NLA), a nitric oxide (NO) synthetase inhibitor, on the activity of Panax quinquefolium L. extracts. Following pretreatment of cultured endothelial cells with NLA, the inhibition of thrombin-induced endothelin release by Panax quinquefolium L. was significantly reduced (P < 0.05). This result suggests that the pharmacological action of Panax quinquefolium L. is, at least partially, due to NO release. Our data demonstrate that American ginseng may play a therapeutic role in facilitating the hemodynamic balance of vascular endothelial cells.

Cells, Cultured↗
PubMed1999

Differences in the urinary excretion of 6-beta-hydroxycortisol/cortisol between Asian and Caucasian women.

The urinary ratio of 6-beta-hydroxycortisol/cortisol has been used as a noninvasive probe for human cytochrome P450 3A4 isoforms (CYP3A4). Ethnic-related differences in the ratio have not been evaluated. The aim of this study was to determine if there are differences in the ratio between Asian and Caucasian women over a menstrual cycle. First-morning urine samples were collected every other day starting from the second day of menstruation for a complete menstrual cycle from 15 Asians and 16 Caucasian women who were 18 to 40 years old, healthy, nonsmoking, and alcohol and drug free, including oral contraceptives. Urine concentrations of 6-beta-hydroxycortisol and cortisol were measured by high-pressure liquid chromatography (HPLC). For statistical analysis, three phases of the menstrual cycle were evaluated: menstruation (days 1-4), follicular or postmenstruation (days 6-10), and the luteal phase (days 21-24) based on the average menstrual cycle (28 days). Statistical analysis was performed by an independent sample t-test using the Bonferroni correction for repeated measures. Large intersubject and intrasubject variations of the 6-beta-hydroxycortisol/cortisol ratios were observed during the menstrual cycles in both ethnic groups. Asian women had a statistically significant lower ratio than Caucasian women did for all three phases of the menstrual cycle: 2.2 +/- 1.1 versus 5.1 +/- 3.5, 2.1 +/- 1.1 versus 6.0 +/- 4.9, and 2.8 +/- 1.6 versus 5.6 +/- 3.0 for the menstruation, follicular, and luteal phases, respectively. The two- to threefold lower 6-beta-hydroxycortisol/cortisol ratios in Asian women suggest that Asian women may have a lower CYP3A activity compared with Caucasian women. Differences in ethnicity may mask potential gender-related effects if ethnic background is not evaluated as a contributing factor.

Adolescent↗
PubMed1999

Dietary intake and sources of isoflavones among Japanese.

We examined the dietary intake and sources of isoflavones (daidzein and genistein) among Japanese subjects based on dietary records (DRs). The subjects comprised two groups: 1,232 who completed one-day DRs (Group 1) and 88 men and women who kept four four-day (16-day) DRs. For quantitative data on the level of daidzein and genistein in soy foods, we extensively reviewed the literature, particularly for Japanese soy foods, and adopted the median value for each food. The median intake of daidzein was 12.1 and 9.5 mg/day among Groups 1 and 2, respectively, while the corresponding values for genistein were 19.6 and 14.9 mg/day. The top four foods (tofu, miso, natto, and fried tofu) covered about 90% of the population intake of daidzein and genistein. It did not seem feasible to estimate one's intake of isoflavones by using dietary recording/recall in epidemiological studies, since the day-to-day variation in intake was too large, the within-person coefficient of variation being 89.1% for daidzein and genistein. Therefore, we should use other methods, such as food-frequency questionnaires, focusing on the four major sources of isoflavones, to assess individual isoflavone intake.

Diet↗
PubMed1999

A simple food frequency questionnaire for Japanese diet--Part I. Development of the questionnaire, and reproducibility and validity for food groups.

We developed a simple food frequency questionnaire (FFQ) based on one-day dietary records (DRs) among 1001 subjects in Nagoya, Japan. A total of 97 foods and dishes were selected through a two-step procedure; first by ranking food items according to the contribution to the population intake of nutrient variables, and second by stepwise multiple regression analyses of individual food items as the independent variables and of total nutrient intake as the dependent variables. For simplicity, questions on portion sizes were not included except for a few selected food items, which resulted in short time (about 20 minutes) to complete the questionnaire. This FFQ was validated for food groups by referring to four 4-day DRs among 88 men and women in central Japan, from 1996 to 1997. The energy-, sex- and age-adjusted test-retest correlation coefficients between the two FFQs administered at an one year interval ranged from 0.34 to 0.78. The de-attenuated, energy-, sex- and age-adjusted correlation coefficients between the second FFQ and the DRs were larger than 0.40 for most food groups, indicating the usefulness of this simple FFQ with its sufficient validity in epidemiological surveys.

Adult↗
PubMed1999

A simple food frequency questionnaire for Japanese diet--Part II. Reproducibility and validity for nutrient intakes.

A self-administered 97-item simple food frequency questionnaire (FFQ), without portion size questions for most items, was completed twice at an one-year interval by 88 men and women in central Japan to evaluate its reproducibility. This FFQ was further validated by referring to four 4-day weighed dietary records (DRs) which were performed at 3-month intervals. Mean energy and 18 nutrient intakes measured by the first and the second FFQs were quite similar to those measured by the DRs. In our reproducibility study, Pearson and intraclass correlation coefficients, adjusted for energy intake, sex and age, ranged from 0.48 to 0.82 (median = 0.67). In the validation study, adjusted and de-attenuated correlation coefficients between the second FFQ and the DRs ranged from 0.42 for iron to 0.83 for calcium (median = 0.61). The proportion of subjects classified by the FFQ into the same or adjacent quintiles defined by the DRs was between 65.9% and 83.0% (median = 69.9%). These findings essentially suggested that our FFQ is well reproducible and sufficiently valid, and therefore, reasonably useful for nutritional epidemiological studies for Japanese diets, particularly for those of Tokai Area.

Adult↗
PubMed1999

Hyperglycemia inhibits insulin activation of Akt/protein kinase B but not phosphatidylinositol 3-kinase in rat skeletal muscle.

Sustained hyperglycemia impairs insulin-stimulated glucose utilization in the skeletal muscle of both humans and experimental animals--a phenomenon referred to clinically as glucose toxicity. To study how this occurs, a model was developed in which hyperglycemia produces insulin resistance in vitro. Rat extensor digitorum longus muscles were preincubated for 4 h in Krebs-Henseleit solution containing glucose or glucose + insulin at various concentrations, after which insulin action was studied. Preincubation with 25 mmol/l glucose + insulin (10 mU/ml) led to a 70% decrease in the ability of insulin (10 mU/ml) to stimulate glucose incorporation into glycogen and a 30% decrease in 2-deoxyglucose (2-DG) uptake, compared with muscles incubated with 0 mmol/l glucose. Glucose incorporation into lipid and its oxidation to CO2 were marginally diminished, if at all. The alterations of glycogen synthesis and 2-DG uptake were first evident after 1 h and were maximal after 2 h of preincubation; they were not observed in muscles preincubated with 25 mmol/l glucose + insulin for 5 min. Preincubation for 4 h with 25 mmol/l glucose in the absence of insulin produced a similar although somewhat smaller decrease in insulin-stimulated glycogen synthesis; however, it did not alter 2-DG uptake, glucose oxidation to CO2, or incorporation into lipids. Studies of insulin signaling in the latter muscles revealed that activation of Akt/protein kinase B (PKB) was diminished by 60%, compared with that of muscles preincubated in a glucose-free medium; whereas activation of phosphatidylinositol (PI) 3-kinase, an upstream regulator of Akt/PKB in the insulin-signaling cascade, and of mitogen-activated protein (MAP) kinase, a parallel signal, was unaffected. Immunoblots demonstrated that this was not due to a change in Akt/PKB abundance. The results indicate that hyperglycemia-induced insulin resistance can be studied in rat skeletal muscle in vitro. They suggest that impairment of insulin action in these muscles is related to inhibition of Akt/PKB by events that do not affect PI 3-kinase.

Animals↗
PubMed1999

Role of a potent inhibitory monoclonal antibody to cytochrome P-450 3A4 in assessment of human drug metabolism.

Cytochrome P-450 (CYP) 3A4 is an inordinately important CYP enzyme that catalyzes the metabolism of a vast array of clinically used drugs. Microsomal proteins of Spodoptera frugiperda (Sf21) insect cells infected with recombinant baculoviruses encoding CYP3A4 cDNA were used to immunize mice and to develop a monoclonal antibody (mAb(3A4a)) specific to CYP3A4 through the use of hybridoma technology. The mAb is both a potent inhibitor and a strong binder of CYP3A4. One and 5 microl (0.5 and 2.5 microM IgG(2a)) of the mAb mouse ascites in 1-ml incubation containing 20 pmol of CYP3A4 strongly inhibited the testosterone 6beta-hydroxylation by 95 and 99%, respectively, and, to a lesser extent, cross-inhibited CYP3A5 and CYP3A7 activity. mAb(3A4a) exhibited no cross-reactivity with any of the other recombinant human CYP isoforms (CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1) in the course of CYP reaction phenotyping and Western immunoblot analyses. The potency of mAb-induced inhibition is insensitive to substrate concentration in human liver microsomes. Therefore, mAb(3A4a) was used to assess the quantitative role of CYP3A4/5 to the metabolism of testosterone and diazepam in five human liver microsomes. The results showed that CYP3A4 and CYP3A5 contribute >95% to both testosterone 6beta-hydroxylation and diazepam 3-hydroxylation and 52 to 73% to diazepam N-demethylation, respectively. In addition, mAb(3A4a) significantly inhibited testosterone 6beta-hydroxylase activity in rhesus monkey liver microsomes to a degree equal to that observed with CYP3A4 in human liver microsomes. By comparison, no inhibition of testosterone 6beta-hydroxylase activity was observed in the presence of dog, rat, and mouse liver microsomes. The selectivity of ketoconazole, a chemical inhibitor of CYP3A4, was probed with mAb(3A4a) and was shown to be highly concentration dependent in the diazepam N-demethylation by human liver microsomes. The results demonstrate that inhibitory and immunoblotting mAb(3A4a) can offer a precise and useful tool for quantitative identification of CYP3A4/5 in the metabolism of drugs in clinical use and drugs in development.

Adult↗
PubMed1999

[Intra- and inter-individual variations in diets of the middle-aged and the elderly].

This study was conducted to examine intra- and inter-individual variations in diets of the middle-aged and the elderly (40 years or older, 46 men and 42 women). The coefficients of variations for intakes of nutrients and food groups were computed from four 4-day weighed dietary records performed at 3-month intervals from June 1996. The results were as follows: a) The highest intra-individual variation (%) for nutrient intake was observed in retinol (men 293.5, women 283.8) and the lowest in carbohydrate (men 17.7, women 22.1). b) The highest inter-individual variation (%) was found in retinol (58.2) in men, and in carotene (56.7) in women. The lowest inter-individual variation (%) was observed in magnesium (17.0) in men, and in carbohydrate (14.4) in women. c) Nuts and seeds showed the highest intra-individual variation (%) for food group intake (men 291.5, women 391.8), while rice presented the lowest (men 30.5, women 38.9). d) The highest inter-individual variation for food group intake (%) was seen in milk and dairy products (111.7) in men and in alcoholic beverages (162.3) in women. The lowest inter-individual variation was observed in potatoes and starches (20.7) in men and in pulses (26.0) in women. e) The number of days necessary to estimate true average nutrient intake was much longer for such vitamins as retinol and carotene (over 50 days) than for macronutrients (3-5 days) except for fat. More than one year was required to estimate intake of nuts and seeds in both sexes and alcoholic beverages or seaweeds in women, whereas only 9-15 days for intake of rice. In conclusion, energy, protein and carbohydrate can be estimated by short-period dietary recalls or records, since their intra-individual variations were relatively small. On the other hand, many days, were found to be required to estimate usual dietary intake of such vitamins as retinol or carotene and that of each food group except for rice. It would therefore be very difficult to estimate usual intake of these nutrients and food groups by short-period dietary recalls or records.

Diet↗