Biomedical subjects

S Li

Publications and source records attributed to S Li.

At least 559 records · Page 31Linked to original sources

PubMed2000

The effect of liposome encapsulated daunorubicin on rabbit eyes after extracapsular lens extraction.

PURPOSE: To investigate the effect of liposome encapsulated daunorubicin (DNR) on rabbit eyes when it was used in prevention of posterior capsule opacification (PCO). METHODS: The liposome encapsulated DNR was prepared by modified freeze-thawing method. Each eye was injected with 0.1 ml liposomes (0.2 mg/ml and 20 micrograms/ml DNR) into the capsular bag during the extracapsular lens extraction (ECLE) in 10 rabbit eyes respectively. The phosphate buffer solution (PBS) was injected as control. Besides biomicroscope observation and histology examination of all eyes, the concentration of DNA in aqueous humor was also determined by high performance liquid chromatography (HPLC). RESULTS: The morphology of liposome encapsulated DNR were similar to the blank liposome with round or ellipse shape. The encapsulated effeciency of liposome encapsulated DNR was 45.1%. The inflammatory response was much more severe both in 0.2 mg/ml and 20 micrograms/ml DNR group than the control after liposome injection. All eyes in DNR group were showed severe corneal edema and opacity and lasted for 4 to 8 weeks. Histopathological study revealed that lens epithelial proliferation occured by 4 weeks and Soemmering's ring developed by 8 weeks in control; However, in DNR group eye only a few LECs remained in the bag and there were obvious corneal edema and eosinophiles infiltration. Corneal endothelial cells were severely lost. CONCLUSION: The results suggest that liposome encapsulated DNR could inhibit metaplasia and proliferation of remnant lens epithelial cells after ECLE in rabbit eyes, but the severe toxicity must be avoided by further study.

Animals↗

PubMed2000

Growth inhibition, induction of apoptosis by green tea constituent (-)-epigallocatechin-3-gallate in cultured rabbit lens epithelial cells.

PURPOSE: To evaluate effect of green tea extract (-)-Epigallocatechin-3-gallate (EGCG) in cultured rabbit lens epithelial cells in order to pave a new way to postcapsular opacity (PCO) prevention. METHODS: Cell survival rate was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) coloimetric assay. Cell apoptosis was detected by electron microscopy, Hochest 33258 stain and flow cytometer. DNA fragment was detected using agarose gel electrophoresis. RESULT: Proliferation of the cultured rabbit lens epithelia cells was inhibited by EGCG in a dose and time dependent manner. Morphologic study showed that the cells became shrunk, round shaped with their nuclei condensed and broken. Apoptotic bodies were also seen under electron microscope and in Hochest 33258 stain assay 24 hours after EGCG was added to the medium. DNA ladders were shown in agarose gel electrophoresis. In flow cytometry assay, apoptosis peak was also evident. CONCLUSION: Green Tea Constituent(-)-Epigallocatechin-3-gallate could inhibit cultured rabbit lens epithelial cells proliferation by inducing their apoptosis in the concentration used by us, which indicates that it is possible to prevent PCO by using herb extract.

Animals↗

PubMed2000

Preliminary study on in vitro induced differentiation of embryonic stem cells into neurons.

PURPOSE: To study preliminarily in vitro induced differentiation of embryonic stem cells into neurons for further investigation of an alternative for the treatment of glaumatous neuropathy. MATERIALS AND METHODS: Supernatant of cultured Buffalo rat liver cells (buffalorat liver cell-conditioned medium, BRL-CM) was used for culturing embryonic stem cells (ES-D3 cell line). Morphological features of undifferentiated ES cells were studied by HE staining and electron microscopy. Based on the methods used by Bain et al, we modified the methods and used retinoic acid (RA) as an inducer to differentiate ES-D3 cells and cytosine arabinoside (Ara-C) as inhibitor of proliferative cells. The growth of the cells was observed under phase contrast microscope. RESULTS: ES-D3 cells cultured by BRL-CM grew in aggregates and remained undifferentiated. Electromicroscopy showed large nucleus and a large amount of mitochondria in undifferentiated ES cells and many processes on the surfaces. In the first day after the adding of retinoic acid, some neuron-like cells with one, two or more processes were present. In the second day after adding RA and the first day after the plus of 10 microns Ara-C, a large amount of neuron-like cells appeared, with the formation of neuron-like networks. CONCLUSIONS: Combined use of RA and Ara-C can induce ES cells to differentiate into neuron-like cells. Our present preliminary study might provide insights into an alternative for the treatment of glaucomatous neuropathy by the transplantation of embryonic stem cells.

Animals↗

PubMed2000

Quantitative study of basic fibroblast growth factor in vitreous with proliferative vitreoretinopathy.

OBJECTIVE: To quantitatively study basic fibroblast growth factor (bFGF) in the vitreous of proliferative vitreoretinopathy (PVR) in order to understand the role of bFGF in the development of PVR. METHOD: High sensitive sandwich enzyme immunoassay technique (ELISA) was used to measure bFGF level in vitreous of normal eyes, the eyes of PVR-C or PVR-D grade, eyes of vitreous hemorrhage and the serum levels of bFGF in PVR-D patients. RESULTS: The levels of bFGF in the vitreous were: median 5.20 ng/L, quartile 15.47 ng/L in 20 normal eyes; median 3.12 ng/L, quartile 10.48 ng/L in 35 PVR-C eyes; median 46.56 ng/L, quartile 113.96 ng/L in 26 PVR-D eyes; median 1.40 ng/L, quartile 6.25 ng/L in 25 vitreous hemorrhage eyes. The vitreous bFGF level in PVR-D group was significantly higher than that in the normal group, PVR-C group and vitreous hemorrhage group (P < 0.01). The mean of serum-bFGF level was 18.33 +/- 3.39 ng/L. The vitreous bFGF level of PVR-D group was significantly higher than serum-bFGF level (P < 0.01). And the vitreous-bFGF level in PVR-D group was significantly higher in larger retinal tear subgroup. CONCLUSION: The results suggested that bFGF is involved in the development of PVR.

Adult↗

PubMed2000

[Sodium salicylate induced intracellular Ca2+ concentration change in guinea pig outer hair cells].

OBJECTIVE: In order to explore the mechanism of sodium salicylate ototoxicity the effect of sodium salicylate on intracellular Ca2+ ([Ca2+]i) of the outer hair cells (OHCs) and the effects of calcium channel antagonist on sodium salicylate-induced [Ca2+]i changes of the OHCs were examined. METHODS: The OHCs of guinea pig cochlear were isolated using an enzyme-machine methods and loaded with 10 mumol/L Fluo-3/AM for 30 min at 37 degrees C. Individual Fluo-3 loaded OHC was examined with a confocal microscope (ACAS Ultima, USA) using a 20 x objective lens and linear scan mean. The fluorescent images, collected each 5-sec for 300 sec, were stored in a computer. The fluorescent intensity of the OHCs were analyzed by the software cooperated with the confocal microscope, and a curve of fluorescent intensity changes trend against time was obtained. RESULTS: The [Ca2+]i of OHCs were steady under normal extracellular liquid perfusion. Salicylate increased [Ca2+]i in OHCs in calcium-free medium(10/10) and standard medium (8/10). 3 mmol/L lidocaine inhibited [Ca2+]i increase in OHCs induced by salicylate(0/10). The [Ca2+]i increase in OHCs induced by salicylate could be blocked by flunarizine(3/12). Nimodipin failed to block the [Ca2+]i increase of OHCs induced by salicylate (7/7). CONCLUSION: Sodium salicylate can result in [Ca2+]i increase in OHC markedly, which may be due to the Ca2+ release from intracellular calcium stores. The effects of salicylate on [Ca2+]i in OHCs might be one of the mechanisms of salicylate ototoxicity.

Animals↗

PubMed2000

[CT anatomic measurement of the optic canal and its clinical significance].

OBJECTIVE: To probe into the normal anatomy of the optic canal and its clinical significance. METHODS: The optic canals of 200 normal subjects were examined by thin layer CT scan in axial nd coronal positions. The distance and anatomic relationship with circumferentral structure were measured. RESULTS: In average: (1) The transverse diameter of the optic canal was (3.57 +/- 0.61) mm, the longitudinal diameter was (4.82 +/- 0.38) mm, the length of the inner wall was (12.62 +/- 2.59) mm, the length of the outer wall was (10.18 +/- 2.19) mm, and the length of the optic canal was (11.46 +/- 2.35) mm. The angle between optic canal and the middle line of the skull was 34.34 degrees +/- 6.48 degrees, the angle between optic canal and the intraorbital optic was 10.69 degrees +/- 6.48 degrees. The thickness of the inner wall was (0.68 +/- 0.46) mm. It showed no significant difference between the two sides of the optic canal in diameters(P > 0.05). (2) The optic canal, the superior orbital fissure and the inferior orbital fissure were respectively shown as track, crack and gorge type in CT axial pictures, while in the coronal pictures, they were respectively shown as butterfly eyes, horizontal fissure and vertical fissure type. (3) The relationship of the posterior ethmoid sinus and the optic canal was: anterocanal(42.00%), semicanal(27.5%), whole-canal(18.75%), sella turcica(9.75%) and circumcanal(2.00%). (4) The relationship of the position of the sphenoidal sinus and the optic canal was: I degree sphenoidal sinus(20%), II degree (63%) and III degree (17%). (5) The incidence of the bony defect of the inner optic canal wall was 25.5%. The range of the defect was (5.07 +/- 2.52) mm. CONCLUSION: It's a reliable way to show the relation of the optic canal and circumcanal by CT, and it is of important value in operation.

Adolescent↗

PubMed2000

[Expression of human papillomavirus DNA in cholesteatoma of the middle ear].

OBJECTIVE: To reveal the role of HPV in the occurrence and development of cholesteatoma of the middle ear. METHOD: PCR and nuclear acid hybridization were applied in screening 44 cases of middle ear cholesteatoma for detection of HPV DNA, and a comparison analysis with the pathological results of 35 cases of middle ear cholesteatoma was made. RESULTS: Pathologically, the characteristics of HPV induced-lesions was found in 12 of 35 specimens (34.3%). 44 cases of middle ear cholesteatoma were examined with consensus primers PCR and digoxigenin labeled HPV general probes. HPV DNA positive rates were 29.5% (13/44) and 25.0% (11/44) respectively. HPV DNA positive rate was 58.3% (7/12) and 13.0% (3/23) respectively in 12 cases with pathological characteristics of HPV induced-lesions and in 23 cases without those characteristics. There was significant difference(chi 2 = 7.926, P < 0.005). CONCLUSIONS: HPV infection can arouse the cleavage and proliferation of cholesteatoma epithelium and may play certain role in the occurrence and development of middle ear cholesteatoma. Aggressive, papillomatous growth and koilocytes can be served as the initial proof of HPV infection in cholesteatoma of the middle ear.

Adolescent↗

PubMed2000

[Histological study of the local-regional invasion of pyriform sinus carcinoma].

OBJECTIVE: In order to offer the basis for the operation of the pyriform sinus carcinoma, the local-regional invasion patterns of the pyriform sinus carcinoma were investigated. METHODS: Twenty-six surgical specimens obtained from patients who undergone laryngopharyngectomy were subjected to a whole organ section study. RESULTS: Tumors located in the lateral wall of the pyriform sinus spread mainly towards the lateral wall of the hypopharynx. Tumors located in the inner wall of the pyriform sinus spread mainly towards the larynx and opposite side pyriform sinus, the paraglottic space and thyroid cartilage were particularly frequent invaded. It was rare of the invading of the cricoid cartilage. The invasion of the epiglottis and preepiglottic space across the midline had not been found. There were two invading routines, the paraglottic space and preepiglottic space. The invasion of the paraglottic space was through the aryepiglottic fold and the inner surface of the thyroid cartilage. The invading of the preepiglottic space was through the aryepiglottic fold and the upper part of the inner surface of the thyroid cartilage. CONCLUSIONS: The invading of the preepiglottic space was not the contraindication of the partial laryngectomy. It is practicable to preserve the laryngeal function in most of the patients while tumors located on the lateral or inner wall of the pyriform sinus. There was a tendency to the invading to the contralateral side in the inner wall of the pyriform or postcricoidarytenoid region. Attention should be paid to the submucosal spreading in the postcricoidarytenoid region.

Adult↗

PubMed2000

[Preoperative superselective intra-internal iliac arterial chemotherapy for invasive bladder cancer and curative analysis].

OBJECTIVE: To study clinical effects of preoperative intra-internal iliac-arterial chemotherapy for invasive bladder cancer. METHODS: 14 cases of invasive bladder cancer underwent superselective intra-internal iliac-arterial chemotherapy before conservative cystectomy. RESULTS: After 2-3 week therapy, reduction of cancer volume (20%-50%), clotted by thrombus in the blood vessels of the cancer or circumferential tissue, and decreased bleeding were found. Pathomorphological features included large patchy necrosis, degeneration, and inflammatory changes of carcinoma tissue. Follow-up ranged from 5 to 42 months (mean 19.6 months). One T3 N1 M0) of the cases (0.7%) relapsed into T1N0M0 and the others did not. CONCLUSIONS: The intra-internal iliac-arterial method, simple, safe, coordinates in pre-operation for invasive bladder cancer, and increases the operative opportunity for preservation of functional bladder.

Aged↗

PubMed2000

[Effects of urapidil and cimetidine on wedged hepatic venous pressure and systemic hemodynamics in cirrhotic patients with portal hypertension].

OBJECTIVE: To compare the effects of urapidil and cimetidine on portal pressure and systemic hemodynamics. METHODS: We observed the effects of urapidil (urapidil HCl, n = 15), cimetidine (n = 20) and placebo (0.9% sodium chloride, n = 10) on wedged hepatic venous pressure (WHVP), hepatic venous pressure gradient (HVPG), and systemic hemodynamics. RESULTS: Urapidil at a dosage of 25 mg intravenously reduced WHVP from 33.33 +/- 7.85 cm H2O to 23.75 +/- 6.83 cm H2O, the average value was 28.75% +/- 9.81% (P > 0.01); and HVPG from 21.92 +/- 2.34 cm H2O to 14.07 +/- 3.57 cm H2O, the average value was 35.81% +/- 8.71% (P < 0.01). The free hepatic venous pressure (FHVP) however was not changed significantly (P > 0.05). The heart rate was increased from 70 +/- 13 BPM to 79 +/- 21 BPM (P < 0.05), and the systolic blood pressure and the diastolic blood pressure were reduced from 122 +/- 40 mm Hg to 95 +/- 32 mm Hg and 75 +/- 17 mm Hg to 55 +/- 15 mm Hg respectively (P < 0.01). After cimetidine administered at a dosage of 400 mg intravenously, WHVP and HVPG were reduced from 34.25 +/- 7.34 cm H2O to 29.05 +/- 7.03 cm H2O and 23.14 +- 8.15 cm H2O to 17.13 +/- 4.28 cm H2O; and the average value was 15.18% +/- 8.64% and 26.00% +/- 12.19% respectively (P < 0.01). But heart rate, blood pressure and FHVP were not altered after use of cimetidine ( P > 0.05). In the control group (n = 10), WHVP, HVPG, FHVP, heart rate, as well as blood pressure were not changed after placebo treatment. CONCLUSIONS: Both urapidil and cimetidine could reduce WHVP and HVPG significantly in cirrhotic patients with portal hypertension, and the effect of the two agents on WHVP and HVPG was not obviously different (P > 0.05). However, the systemic hemodynamic effects induced by urapidil were more significant compared with cimetidine.

Adult↗

PubMed2000

The value of 99mTc-MIBI myocardial perfusion spect imaging in detecting coronary artery disease in patients with valvular disease before operation.

OBJECTIVE: The aim of this study was to detect coronary artery disease using 99mTc-MIBI myocardial perfusion imaging in patients with valvular disease. METHODS: Thirty patients with valvular disease confirmed by echocardiography underwent 99mTc-MIBI myocardial perfusion imaging using multiSPECT 1h after stress test (exercise, dipyridamole or dobutamine test) and were performed coronary angiography within 1 month before valvular operation. RESULTS: For 29 out of the 30 patients, the results of 99mTc-MIBI myocardial perfusion imaging were similar with those of coronary angiography, the concordance rate was 96.7% and the negative predictability was 100%. CONCLUSION: 99Tc-MIBI myocardial perfusion imaging is a reliable non-invasive method for detecting coronary artery disease in patients with valvular disease and so as to draw up suitable operation programs for them.

Coronary Angiography↗

PubMed2000

[Expression of IL-2 receptors on the surfaces of L1210 cells and bioactivity assay for IL-2-toxin fusion proteins].

OBJECTIVE: To confirm that L1210 cells surfaces express IL-2 receptors (IL-2R) and to establish experimental models for studying the cytotoxic effect of IL-2-toxin fusion protein in vivo and in vitro. METHODS: IL-2R on mouse leukemia L1210 cells was analyzed with immunofluorescence stain and FACS. The cytotoxic effects in vitro of these fusion proteins IL-2-PEZNM and IL-2-K-PEZNM were assayed by MTT method; mice ascitic L1210 leukemia was induced by i.p. L1210 cells and the therapeutic effect of IL-2-K-PEZNM was observed. RESULTS: 86.3% of L1210 cells expressed IL-2R on their surfaces and the relative fluorescence intensity was 51.55. Two fusion proteins IL-2-PEZNM and IL-2-K-PEZNM showed dose-related cytotoxicities to L1210 cells in vitro with the IC50 of 0.51 and 0.67 microgram/ml respectively. IL-2-K-PEZNM (5 micrograms/d) showed significantly inhibitory effect on L1210 cells and prolonged the survival time of mice by 78.6%. CONCLUSIONS: L1210 cells as a model system to measure the cytotoxic activity of IL-2-toxin fusion proteins both in vitro and in vivo is simpler, stabler, and safer model than those with other cells such as Hut102 and activated T lymphocytes.

Animals↗

PubMed2000

The treatment of chylothorax.

OBJECTIVES: To understand and grasp the diagnosis and treatment of chylothorax caused by variou reasons. METHOD: The treatment results of 31 cases of chylothorax in PUMC hospital from 1963 approximately 1997 were retrospectively analyzed. RESULTS: Among 31 cases, 18 underwent surgery, 14 of 18 were cured, 2 died. In the 13 treated conservatively, 2 were cured, 3 died. Eleven cases were congenital, iatrogenic and traumatic chylothorax, 8 of them received surgical treatment and 6 of 8 were cured. The spontaneous chylothorax of unknown cause were 10 cases, 7 were treated by surgery and 6 were cured. CONCLUSION: Surgical intervention should be aggressively recommended for the traumatic, congenital, and iatrogenic chylothorx. The definite reason must be found out for the spontaneous chylothorax, corresponding management will be given according to the reason. Surgical ligation of the thoracic duct will contribute good result for the chylothorax of unknown cause, but combination of multiple treatment measures will be necessary for a successful management.

Adolescent↗

PubMed2000

[Determination of trace elements Cu, Zn, Mg, Cr, Mn in serum of people with hepatoma, cirrhosis, hepatapstema disease].

Using AAS method, we detected serum Zn, Cu, Mn, Cr, Mg in the people with hepatoma, cirrhosis and hepatophyma disease. The results showed that the level of serum Cu of people with hepatoma and cirrhosis were significantly higher than those in the healthy control and with hepatophyma disease (P < 0.01). The levels of serum Mn, Cr of those with hepatoma and cirrhosis disease were significantly lower than those with hepatophyma and the healthy control (P < 0.01). It is concluded that determination of Cu, Mn, Cr may be one of the methods to diagnose hepatoma and cirrhosis disease.

Adolescent↗

PubMed2000

[Determination of nickel based on the fluorescence quenching of phenanthroline].

A new selective and sensitive spectrofluorimetric method for the determination of trace amounts of nickel in industrial waste water has been developed. This method is based on the quenching of fluorescence of phenanthroline due to the formation of complex Ni (II)-Phen. The exitation and emission wavelengths were found to be 272 and 366 nm, respectively. There was a linear relationship in the range of 10.0-120 ng.mL-1 for Ni. This method is simple and rapid, and has been applied to the determination of nickel in industrial waste water.

Nickel↗

PubMed1999

Th1 and Th2 deviation of myelin-autoreactive T cells by altered peptide ligands is associated with reciprocal regulation of Lck, Fyn, and ZAP-70.

Th0 clones recognizing an immunodominant peptide of myelin basic protein (residues 83-99) were derived from patients with multiple sclerosis. We demonstrate that analogue peptides with alanine substitution at Val86 and His88 had a unique partial agonistic property in inducing Th0 -->Th1 and Th0 -->Th2 deviation of the myelin basic protein-reactive T cell clones, respectively. Th0 to Th1 deviation induced by peptide 86V-->A correlated with up-regulation of Fyn and ZAP-70 kinase activities. Conversely, Th0 to Th2 deviation induced by peptide 88H-->A was associated with complete failure to activate Fyn and ZAP-70 kinases. The observed Th1 and Th2 shift also correlated, to a lesser extent, with Lck kinase activity that was down-regulated with Th1 deviation and increased with Th2 deviation in some T cell clones. We demonstrated that the Th1 and Th2 shift induced by the analogue peptides was a reversible process, as the T cell clones previously exposed to either 86V-->A or 88H-->A peptide could revert to an opposite phenotype when rechallenged reciprocally with a different analogue peptide. The study has important implications in our understanding of regulation of TCR-associated tyrosine kinases by altered peptide ligands and its role in cytokine regulation of autoreactive T cells.

Alanine↗

PubMed1999

Calorimetric and molecular mechanics studies of the thermotropic phase behavior of membrane phospholipids.

In this review, we summarize the results of recent studies on the main phase transition behavior of phospholipid bilayers using the combined approaches of molecular mechanics simulations and high-resolution differential scanning calorimetry. Following a brief overview of the phase transition phenomenon exhibited by the lipid bilayer, we begin with the review by showing how several structural parameters underlying various phospholipids including phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol are defined and determined. Specifically, these structural parameters are obtained with saturated lipids packed in the gel-state bilayer using computer-based molecular mechanics calculations. Then we proceed to present the calorimetric data obtained with the lipid bilayer composed of saturated phospholipids as it undergoes the gel-to-liquid-crystalline phase transition in excess water. The general equations that can correlate the gel-to-liquid-crystalline phase transition temperature (T(m)) of the lipid bilayer with the structural parameters of the lipid molecule constituting the lipid bilayer are subsequently presented. From these equations, two tables of predicated T(m) values for well over 400 molecular species of saturated phosphatidylcholine and saturated phosphatidylethanolamine are generated. We further review the structure and chain-melting behavior of a large number of sn-1 saturated/sn-2 unsaturated phospholipids. Two T(m)-diagrams are shown, from which the effects of the number and the position of one to five cis carbon-carbon double bonds on T(m) can be viewed simultaneously. Finally, in the last part of this review, simple molecular models that have been invoked to interpret the characteristic T(m) trends exhibited by lipid bilayers composed of unsaturated lipids with different numbers and positions of cis carbon-carbon double bonds as seen in the T(m)-diagram are presented.

Calorimetry, Differential Scanning↗

PubMed1999

Prevention of neural-tube defects with folic acid in China. China-U.S. Collaborative Project for Neural Tube Defect Prevention.

BACKGROUND AND METHODS: Periconceptional administration of folic acid can reduce a woman's risk of having a fetus or infant with a neural-tube defect. As part of a public health campaign conducted from 1993 to 1995 in an area of China with high rates of neural-tube defects (the northern region) and one with low rates (the southern region), we evaluated the outcomes of pregnancy in women who were asked to take a pill containing 400 microg of folic acid alone daily from the time of their premarital examination until the end of their first trimester of pregnancy. RESULTS: Among the fetuses or infants of 130,142 women who took folic acid at any time before or during pregnancy and 117,689 women who had not taken folic acid, we identified 102 and 173, respectively, with neural-tube defects. Among the fetuses or infants of women who registered before their last menstrual period and who did not take any folic acid, the rates of neural-tube defects were 4.8 per 1000 pregnancies of at least 20 weeks' gestation in the northern region and 1.0 per 1000 in the southern region. Among the fetuses or infants of the women with periconceptional use of folic acid, the rates were 1.0 per 1000 in the northern region and 0.6 per 1000 in the southern region. The greatest reduction in risk occurred among the fetuses or infants of a subgroup of women in the northern region with periconceptional use who took folic acid pills more than 80 percent of the time (reduction in risk, 85 percent as compared with the fetuses or infants of women who registered before their last menstrual period and who took no folic acid; 95 percent confidence interval, 62 to 94 percent) [corrected]. In the southern region the reduction in risk among the fetuses or infants of women with periconceptional use of folic acid was also significant (reduction in risk, 41 percent; 95 percent confidence interval, 3 to 64 percent). CONCLUSIONS: Periconceptional intake of 400 microg of folic acid daily can reduce the risk of neural-tube defects in areas with high rates of these defects and in areas with low rates.

Adult↗