Biomedical subjects

Jun Li

Publications and source records attributed to Jun Li.

At least 523 records · Page 29Linked to original sources

PubMed2003

Concepts in immunology and diagnosis of hydatid disease.

Echinococcosis is a cosmopolitan zoonosis caused by adult or larval stages of cestodes belonging to the genus Echinococcus (family Taeniidae). The two major species of medical and public health importance are Echinococcus granulosus and E. multilocularis, which cause cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively. Both CE and AE are both serious diseases, the latter especially so, with a high fatality rate and poor prognosis if managed inappropriately. This review discusses new concepts and approaches in the immunology and diagnosis of CE, but comparative reference has also been made to AE infection and to earlier pivotal studies of both diseases. The review considers immunity to infection in the intermediate and definitive hosts, innate resistance, evasion of the immune system, and vaccination of intermediate and definitive hosts, and it particularly emphasizes procedures for diagnosis of CE and AE, including the value of immunodiagnostic approaches. There is also discussion of the new advances in recombinant and related DNA technologies, especially application of PCR, that are providing powerful tools in the fields of vaccinology and molecular diagnosis of echinococcosis.

Allergy and Immunology↗

PubMed2003

Regulation of alternative splicing by SRrp86 and its interacting proteins.

SRrp86 is a unique member of the SR protein superfamily containing one RNA recognition motif and two serine-arginine (SR)-rich domains separated by an unusual glutamic acid-lysine (EK)-rich region. Previously, we showed that SRrp86 could regulate alternative splicing by both positively and negatively modulating the activity of other SR proteins and that the unique EK domain could inhibit both constitutive and alternative splicing. These functions were most consistent with the model in which SRrp86 functions by interacting with and thereby modulating the activity of target proteins. To identify the specific proteins that interact with SRrp86, we used a yeast two-hybrid library screen and immunoprecipitation coupled to mass spectrometry. We show that SRrp86 interacts with all of the core SR proteins, as well as a subset of other splicing regulatory proteins, including SAF-B, hnRNP G, YB-1, and p72. In contrast to previous results that showed activation of SRp20 by SRrp86, we now show that SAF-B, hnRNP G, and 9G8 all antagonize the activity of SRrp86. Overall, we conclude that not only does SRrp86 regulate SR protein activity but that it is, in turn, regulated by other splicing factors to control alternative splice site selection.

Adenosine Triphosphatases↗

PubMed2003

Promoter usage and estrogen regulation of prolactin receptor gene in the brain of the female rat.

Mechanisms underlying hormonal regulation of prolactin receptor (PRL-R) gene in the brain are unknown. The 5'-untranslated region of PRL-R mRNA in peripheral tissues contains at least three alternative first exons (1A, B, C) that are expressed as tissue-specific, suggesting the differential usage of PRL-R gene promoters. The present study aimed to investigate: (1). the possible regulation of PRL-R mRNA levels by estrogen in in vitro and in vivo tissues; (2). which exon (1A, or 1B, or 1C)-containing PRL-R mRNA transcript is expressed in the brain, and (3). how the specific exon 1-containing mRNA is affected by estrogen by using RT-PCR, Southern blot and 5'Race PCR techniques. The RT-PCR results showed that PRL-R mRNA was detected in the cerebral cortex and pons medulla in addition to the choroid plexus and hypothalamus in the female rat. The expression of PRL-R mRNA was up-regulated by estrogen treatment in the rat brain tissue and in the GT1-7 cell culture. Both exon 1A- and 1C-containing transcripts were expressed in all four regions, suggesting that promoters 1A and 1C for the PRL-R gene are utilized in the rat brain. Exon 1A-containing transcript was up-regulated by estrogen treatment in all four brain regions, whereas Exon 1C-containing transcript was up-regulated by estrogen treatment in 3 of the 4 brain regions, cerebral cortex being the exception. Exon 1B-containing transcript was neither detectable nor induced by estrogen treatment in any of the brain regions examined. The RT-PCR results were confirmed by partial isolation of 5'-untranslated regions of exon 1A- and 1C-containing PRL-R mRNA transcripts from brain tissue by using 5'Race PCR. The present result confirms the expression of PRL-R mRNA in the cerebral cortex and pons medulla in the female rat. The levels of PRL-R mRNA were up-regulated by estrogen in rat brain tissue and GT1-7 cell cultures. Detection of exon 1A- and 1C-containing transcripts implies that the promoter 1A and 1C are active in the female rat brain. Estrogen differentially regulates expression of the PRL-R mRNA in the different brain regions by increasing the utilization of PRL-R gene promoters 1A and 1C in the female rat.

Alternative Splicing↗

PubMed2003

Microarray technology: a review of new strategies to discover candidate vulnerability genes in psychiatric disorders.

OBJECTIVE: An international effort is in progress to discover candidate genes and pathways associated with psychiatric disorders, including two of the most serious diseases, schizophrenia and mood disorders, through the use of new technology-microarrays. Instead of studying one gene at a time, microarrays provide the opportunity to analyze thousands of genes at once. METHOD: This article reviews the steps in this discovery process, including the acquisition and characterization of high-quality postmortem brain tissue, RNA extraction, and preparation and use of microarray technology. Two alternative microarray methods and factors affecting the quality of array data are reviewed. RESULTS: New analytical strategies are being developed to process the massive data sets generated by microarray studies and to define the significance of implicated genes. Array results must be validated by other methods, including in situ hybridization and real-time polymerase chain reaction. Identified genes can also be evaluated in terms of their chromosomal locations and possible overlap with regions of suggestive linkage or association identified with genome-wide linkage analysis in psychiatry and in terms of overlap with genes identified by microarray studies in animals administered psychoactive drugs. Microarray studies are only the first major step in the process. Further efforts in the investigation involve multiple strategies for studying function and gene structure, including transgenic and knockout animal studies. CONCLUSIONS: Microarrays present a methodology that can identify genes or pathways for new and unique potential drug targets, determine premorbid diagnosis, predict drug responsiveness for individual patients, and, eventually, initiate gene therapy and prevention strategies.

Brain Chemistry↗

PubMed2003

Inhibition of proteoglycan and type II collagen synthesis of disc nucleus cells by nicotine.

OBJECT: Systemic nicotine has been hypothesized to cause degeneration of the intervertebral disc which in turn decreases vascular supply to the disc through a cholinergic receptor-mediated process. Another possible mechanism may be through direct regulatory effects on disc cells. In this study, the authors tested the hypothesis that nicotine adversely affects nucleus pulposus cells by directly inhibiting proteoglycan synthesis and gene expression of type II collagen (Phase I study). They also assessed the hypothesis that nicotine inhibits the bone morphogenetic protein (BMP)-2-induced upregulation of extracellular matrix (Phase II study). METHODS: Cells were isolated from nucleus pulposus obtained in rat lumbar discs and cultured on a monolayer. Media were treated with nicotine and/or recombinant human (rh)BMP-2 for 7 days. Sulfated glycosaminoglycan (SO4-GAG) in media was quantified using 1,9-dimethylmethylene blue (DMMB) assay. Gene assay of types I and II collagen, Sox9, and glyceraldehyde-3-phosphate dehydrogenase were quantified using reverse transcriptase-polymerase chain reaction (RT-PCR) and real time PCR. In the Phase I study, nicotine-treated (100 microg/ml) and non-treated cells were compared. The s-GAG production and messenger RNA (mRNA) of type II collagen and Sox9 decreased significantly in the nicotine-treated group. In the Phase II study, five groups were compared: 1) non-treatment; 2) rhBMP-2 only (100 ng/ml); and 3-5) with rhBMP-2 (100 ng/ml) and increasing doses of nicotine (1 [third group], 10, [fourth group], 100 [fifth group] microg/ml). The SO4-GAG production and mRNA of type II collagen and Sox9 decreased significantly in the groups treated with rhBMP-2 combined with 10 and 100 microg/ml of nicotine compared with the group treated with rhBMP-2. CONCLUSIONS: The results of this study raise the possibility that nicotine may contribute to the process of disc degeneration by a direct effect on the nucleus pulposus cells, possibly by antagonizing the effect of BMP-2.

Animals↗

PubMed2003

Effect of leflunomide on immunological liver injury in mice.

AIM: To study the effect of leflunomide on immunological liver injury (ILI) in mice. METHODS: ILI was induced by tail vein injection of 2.5 mg Bacillus Calmette-Guerin (BCG), and 10 d later with 10 microg lipopolysaccharide (LPS) in 0.2 mL saline (BCG+LPS). The alanine aminotransferase (ALT), aspartate aminotransferase (AST), nitric oxide (NO) level in plasma and molondiadehyde (MDA), glutathione peroxidase (GSHpx) in liver homogenate were assayed by spectroscopy. The serum content of tumor necrosis factors-alpha (TNF-alpha) was determined by ELISA. Interleukin-1 (IL-1), interleukin-2 (IL-2) and Concanavalin A (ConA)-induced splenocyte proliferation response were determined by methods of (3)H-infiltrated cell proliferation. RESULTS: Leflunomide (4, 12, 36 mg.kg(-1)) was found to significantly decrease the serum transaminase (ALT, AST) activity and MDA content in liver homogenate, and improve reduced GSHpx level of liver homogenate. Leflunomide (4, 12, 36 mg.kg(-1)) significantly lowered TNF-alpha and NO level in serum, and IL-1 produced by intraperitoneal macrophages(PMphi). Moreover, the decreased IL-2 production and ConA-induced splenocyte proliferation response were further inhibited. CONCLUSION: These findings suggested that leflunomide had significant protective action on ILI in mice.

Adjuvants, Immunologic↗

PubMed2003

Antitumor immunopreventive and immunotherapeutic effect in mice induced by hybrid vaccine of dendritic cells and hepatocarcinoma in vivo.

AIM: To develop atumor vaccine by fusion of H22 hepatocarcinoma cells and DC, and to study its protective and therapeutical effect against H22 cell. METHODS: H22-DC vaccine was produced by PEG fusion of H22 and DC induced by cytokine released from splenic mononuclear cells, sorted by CD11c magnetic microbead marker. It was injected through the tail vein of the mice and the H(22)-DC oncogenesis was detected in the liver, spleen and lung. In order to study the therapeutical and protective effect of H(22)-DC against tumor H(22), two groups were divided: immune group and therapeutic group. Immune group was further divided into P, D, HD and H subgroups, immunized by PBS, DC, H(22)-DC and inactivated H(22), respectively, and attacked by H(22) cell. The tumor size, tumor weight, mice survival time and tumor latent period were recorded and statistically analyzed; Therapeutical group was divided into three subgroups of P, D and HD, and attacked by H(22), then treated with PBS, DC, and H(22)-DC, respectively. Pathology and flow cytometry were also applied to study the mechanism how the H(22)-DC vaccine attacked on the H(22) cell. RESULTS: 1. No oncogenesis was found in spleen, lung and liver after H22-DC injection. 2. Hybrid vaccine immunized mice had strongest CTL activity. 3. In the immune group, latent period was longer in HD subgroup than that in P, H and D subgroup; and tumor size and weight were smaller in HD subgroup than that in P, H and D subgroup. 4. In therapeutic group, tumor size was smaller in HD subgroup than that in P, D subgroup. CONCLUSION: 1. H22-DC tumor vaccine is safe without oncogenesis in vivo. 2. Hybrid vaccine can stimulate potent specific CTL activity against H22. 3. H22-DC vaccine has distinctive prophylatic effect on tumor H22 and can inhibit the tumor growth.

Animals↗

PubMed2003

[Alteration of P53 protein expression and p53 gene in laryngeal carcinoma].

OBJECTIVE: To study the prevalence of P53 protein expression and p53 gene mutation in laryngeal carcinoma. METHODS: Using immunohistochemistry P53 expression was detected in 31 patients with laryngeal carcinoma. In 11 P53 negative patients,microdissection-PCR-HA technique was used to determine mutation in p53 exon 5, 6, 7, 8. RESULTS: Among the 31 patients tested with immunostaining, the overall average positive rate was 64.5%. Positive rates for T3 and T4 tumors were 86.7% vs 43.8% in T1 and T2 tumors.The positive rate was 91.7% in those with cervical node metastasis compared with 47.4% in those without lymph node metastasis. The positive P53 immunostaining was more frequently found in poor differentiated carcinoma (87.5%) and moderate-differentiated carcinoma (66.7%),than in well differentiated carcinoma (45.5%). The abnormal exon 5 or 7 of p53 gene were detected in 2 out of 11 cases, in which P53 was negative. CONCLUSION: P53 gene mutation is related with TNM grading and cervical lymph node metastasis in laryngeal carcinoma. P53 mutation tents to be correlated to pathologic grading.

Adult↗

PubMed2003

Short report: Echinococcus granulosus from Xinjiang, PR China: cDNAS encoding the EG95 vaccine antigen are expressed in different life cycle stages and are conserved in the oncosphere.

The EG95-based vaccine protects sheep from infection with the dog tapeworm Echinococcus granulosus. The EG95 encoding gene is a member of a multigene family, several members of which are expressed in the oncosphere, believed to be the target of immunity induced by the vaccine. E. granulosus exhibits extensive intraspecific (strain) variation, and variability of the eg95 gene in different isolates of E. granulosus may directly impact the effectiveness of the EG95-based vaccine. We analyzed the eg95 gene from E. granulosus collected in Xinjiang, in northwest China, where hydatid disease is hyperendemic. The gene is expressed in oncospheres, protoscoleces, and immature and mature adult worms, and the eg95 gene family was shown to comprise two basic sequence types. Very limited sequence variation was evident in the EG95 protein from oncospheres. This high degree of sequence conservation predicts that the vaccine will continue to be effective in China and elsewhere.

Amino Acid Sequence↗

PubMed2003

Tricuspid valve detachment in closure of congenital ventricular septal defect.

From January 1991 through December 2001, 600 patients underwent closure of a perimembranous ventricular septal defect through a right atrial approach at our institution. In 122 of these patients, the operation included temporary detachment of a tricuspid valve septal leaflet from the annulus to allow complete visualization of a perimembranous ventricular septal defect The mean age of the patients at surgery was 4.6 years in those who underwent leaflet detachment and 4.7 years in the 478 patients who did not (P > 0.05). Preoperatively, all patients were in sinus rhythm. Echocardiography showed trivial tricuspid regurgitation in 21 of the patients undergoing detachment and in 39 of the non-detachment patients. There was no difference in bypass time or aortic cross-clamp time between the 2 groups. Postoperatively, 3 patients in the non-detachment group had heart block; all other patients were in sinus rhythm. Echocardiograms on the 7th postoperative day showed small residual ventricular septal defects in none of the patients who underwent valve detachment and in 10 of the non-detachment patients; mild tricuspid regurgitation was present in 12 non-detachment patients only; and trivial tricuspid regurgitation was present in 19 patients who underwent valve detachment and in 29 who did not. There was no hospital death in either group. Long-term follow-up showed no progression of tricuspid regurgitation or tricuspid stenosis. All patients remained in sinus rhythm. This study suggests that tricuspid valve detachment is a safe, effective technique that improves exposure for ventricular septal defect repair and does not adversely affect valve competence.

Cardiac Surgical Procedures↗

PubMed2003

Microanatomical and neuroendoscopic studies of the internal auditory meatus and its surrounding structures.

OBJECTIVE: To observe the morphology of the internal auditory meatus in relation with its surrounding structures in Chinese people, for the purpose of providing microanatomical reference for surgeries adopting retro-sigmoid approach. METHODS: The retro-sigmoid surgical approach was simulated on 5 fresh specimens of human head, in which the internal auditory meatus and its surrounding structures were observed through a neuroendoscope and a surgical microscope. The distances from the posterior inferior edge of the internal auditory meatus to the central point of the posterior edge of the sigmoid sinus and to the posterior edge of the posterior semicircular canal were measured. RESULTS: The internal auditory meatus was located at the center of the medial surface of the petrous bone, and the cranial nerve VII ran through its anterior-superior part while the cranial nerve VIII through its posterior-inferior part. After forming an arterial loop at the internal auditory meatus, the anterior-inferior cerebellar artery branched into 1 to 3 internal auditory arteries. The distance from the posterior-inferior edge of the internal auditory meatus to the central point of the posterior edge of the sigmoid sinus was 32.15+/-1.76 mm on the left side, and 33.34+/-1.57 mm on the right, and the distance to the posterior edge of the posterior semicircular canal was 12.51+/-2.15 mm on the left side, and 13.26+/-2.44 mm on the right. CONCLUSION: Thorough knowledge of the microanatomy of the internal auditory meatus and its surrounding structures is of crucial importance to preserve the functions of the cranial nerves VII and VIII in the surgical removal of acoustic neuroma.

Asian People↗

PubMed2003

Treatment of open supracondylar fracture of humerus.

OBJECTIVE: To explore the injury mechanism and treatment principle of open supracondylar fracture of humerus. METHODS: The data of 32 patients with open supracondylar fracture of humerus hospitalized in our department in the recent 20 years were analyzed retrospectively. On an average, they were followed up for 30 months. The relationship between the fracture type, situation of wounds, operating time, operating method and time for postoperative functional exercise and final function of elbow joint were evaluated with Flynn scoring standard. RESULTS: Excellent therapeutic effect was found in 14 cases, good in 12 and bad in 6, with the percentage of fine therapeutic effect of 81.25%. CONCLUSIONS: For the patients with open supracondylar fracture of humerus, debridement and internal fixation should be made as early as possible, for thorough debridement and correct internal fixation are the key points to improve the prognosis.

Adolescent↗

PubMed2003

[Isolation and structural identification of phenylethanoid glycosides from Corallodiscus flabellata].

AIM: To study the chemical constituents from Corallodiscus flabellata. METHODS: The compounds were isolated and purified by macroporous adsorption resin, silica gel column chromatography and identified on the basis of their physiochemical and spectral data. RESULTS: Three phenylethanoid glycosides (I-III) were obtained from the n-BuOH fraction of water-extracts. Their structures were elucidated as 3,4-dihydroxyphenylethanol-8-O-[beta-D-apiofuranosyl (1-->3)]-beta-D-glucopyranoside (I), 3,4-dihydroxyphenylethanol-8-O-[4-O-trans-caffeoyl-beta-D-apiofuranosyl (1-->3)-beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (II) and 3,4-dihydroxyphenylethanol-8-O-[beta-D-apiofuranosyl(1-->3)-beta- D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (III). CONCLUSION: Compounds I, II and III are new compounds.

Caffeic Acids↗

PubMed2003

[Studies on the lignan chemical constituents from pine needles of Pinus massoniana Lamb].

AIM: To study the chemical constituents of the pine needles from Pinus massoniana Lamb.. METHODS: Various chromatographic techniques were used for the separation and purification. The physicochemical properties and spectral data were used to elucidate the structures. RESULTS: Three compounds were isolated from the n-BuOH fraction of water-extracts. The structures were identified as (7S,8R)-4,9'-dihydroxyl-3, 3'-dimethyoxyl-7, 8-dihydrobenzofunan-1'-propanolneolignan-9-O-alpha- L-rhamnopyranoside (massonianoside D, 7), 4,4',9,9'-tetrahydroxyl-3,3'-dimethyoxyl-tetrahydrocyclolignan ((+)-isolariciresinol, 8) and 4,4',9'-trihydroxyl-3,3'-dimethyoxyl-tetrahydrocyclolignan-9-O-beta-D- xylopyranoside (isolariciresinol-9-O-xyloside, 9) on the basis of spectral data (ORD, UV, IR, MS, 1HNMR, 13CNMR, 1H-1HCOSY, HMQC and HMBC etc.). CONCLUSION: Compound 7 is a new compound, while compounds 8 and 9 were isolated from this plant for the first time.

Drugs, Chinese Herbal↗

PubMed2003

[Two new phenylethanoid glycosides from Corallodiscus flabellata].

AIM: To study the chemical constituents from Corallodiscus flabellata. METHODS: Fresh plant of Corallodiscus flabellata was extracted twice with boiling water, filtered to remove insoluble materials, concentrated under reduced pressure at temperature 55 degrees C to a small volume. The concentrated liquor was subjected to solvent-solvent partitioning using ether, ethyl acetate, and n-butanol (saturated with water). The fraction of ethyl acetate extract was chromatographed over macroporous adsorption resin (Diaion HP-20) eluted with a mixture of H2O and MeOH in increasing MeOH content. Their fractions from resin were repeatedly chromatographed over Sephadex LH-20, Toyopearl HW-40, gel MCI, Gel CHP-20 and silica gel column. Structures of compounds obtained were identified on the basis of their spectral data, hydrolysis and chemical correlation. RESULTS: Two phenylethanoid glycosides (I, II) and three phenolic acids were obtained from the EtOAc fraction of water-extracts. Their structures were identified as 3,4-dihydroxyphenylethanol-8-O-[beta-D-apiofuranosyl (1-->2)]-beta-D-glucopyranoside (I), 3,4-dihydroxyphenylethanol-8-O-[(5-O- Vanilloyl)-beta-D-apiofuranosyl(1-->2)]-beta-D-glucopyranoside (II), vanillic acid (III), syringic acid (IV) and ferulic acid (V). CONCLUSION: I and II are new compounds. Compounds III, IV and V were isolated from this plant for the first time.

Disaccharides↗

PubMed2003

[Microsurgical repair of skin-degloving injury of whole hand or foot].

OBJECTIVE: To investigate the clinical effects of the microsurgical treatment for the skin-degloving injury of the whole hand or foot. METHODS: From March 1984 to October 2001, we treated 6 cases of skin-degloving injury of the whole hand and foot. In 2 cases of skin-degloving hands, one was treated with free great omentum transplantation plus skin graft, the other with pedical abdominal S-shaped skin flap as well as mid-thick skin graft. In 4 cases of skin-degloving injury of the foot, 2 cases was repaired with free latissimus dosi musculocutaneous flap, 1 case with distall-based lateral skin flap of the leg and 1 case with free tensor fasciae latae muscle flap. The flap size ranged from 7 cm x 9 cm to 22 cm x 15 cm. One case was operated on the emergency stage, the other 5 cases on the delayed stage. The delayed time ranged from 2 to 14 days with an average of 6.6 days. RESULTS: All the flaps survived. After 1-2 year follow-up, the appearance and function of the hand and the foot were good. CONCLUSION: Microsurgery technique in repairing skin-degloving injury of the whole hand and foot can achieve good results. The keys to success are thorough debridement of the recipient area, appropriate selection of the donor site, good vascular anastomosis and active postoperative rehabilitation.

Adult↗

PubMed2003

[Study of severe hepatitis treated with a hybrid artificial liver support system].

OBJECTIVES: To evaluate the efficacy of a hybrid artificial liver support system in the treatment of chronic severe hepatitis. METHODS: The hybrid artificial liver support system (HALSS) consisted of a bioreactor containing more than 5 x 10(9) porcine hepatocytes and plasma exchange device. 15 patients with chronic severe viral hepatitis were treated with the hybrid system. RESULTS: All the patients experienced a reduction in symptoms, such as fatigue, abdominal distention or ascites. After each treatment serum total bilirubin decreased markedly (from 493.5 micromol/L+-139.8 micromol/L to 250.9 micromol/L+-91.3 micromol/L, t=8.695, P<0.001), while prothrombin activity increased (from 24.5%+-8.4% to 30.6%+-6.3%, t=3.325, P<0.01). There were 11 patients whose progress of hepatocytes necrosis stopped after HALSS treatment, and finally they recovered completely. Four patients died of their worsen conditions. No serious adverse events were noted in the 15 patients. CONCLUSION: HALSS is a reliable hepatic support device for chronic severe hepatitis.

Adult↗

PubMed2003

[Association studies of dopamine D4 receptor gene and dopamine transporter gene polymorphisms in Han Chinese patients with attention deficit hyperactivity disorder].

OBJECTIVE: To investigate association of the 48 bp variable number of tandem repeat (VNTR) polymorphism in the D4 receptor gene (DRD4) exon 3 and 40 bp VNTR polymorphism in the dopamine transporter gene (DAT1) 3' untranslated region with attention deficit hyperactivity disorder (ADHD) in Han Chinese children. METHODS: The study samples were comprised of 340 ADHD children, 226 unrelated controls and 202 integrated ADHD trios (included proband and biological parents). The polymorphisms consisted of 48 bp VNTR in exon 3 of DRD4, and 40 bp VNTR in the 3' untranslated region of DAT1. Associations of polymorphisms with ADHD and its subtypes were examined by: (i) comparing cases and controls; and (ii) using family-based association study in an extension of exact transmission-disequilibrium test (ETDT) and haplotype-based haplotype relative risk (HHRR). RESULTS: The repeat numbers at the DRD4 48 bp locus ranged from 2-6 repeats in the Han Chinese controls, with the most common being the 4-repeat (77%) and 2-repeat (19.4%) alleles. Neither the 7-repeat allele nor longer repeats were found. For the DAT1, the repeat numbers at the 40 bp locus ranged from 6-7 repeats and 9-11 repeats. The 10-repeat allele was the most frequent (90.7%). The long-repeat alleles of DRD4 (ranging from 4-6 repeats) and DAT1 (ranging from 11-12 repeats), were present more frequently in ADHD probands than in controls. Our primary analyses failed to replicate the associations between ADHD and 7-repeat allele of DRD4 and the 10-repeat allele of DAT1. CONCLUSION: The long-repeat alleles of DRD4 (after a stratification by gender) and DAT1 may increase the risk for ADHD in Han Chinese children.

Alleles↗