Biomedical subjects

Ming Fu

Publications and source records attributed to Ming Fu.

At least 19 recordsLinked to original sources

PubMed2026

Surface shaving proteomics reveals a parasite-encoded protein embedded in the spore filaments of Ameson portunus.

The surfaces of microsporidian spores are frequently adorned with filamentous appendages of unknown origin and function. Although some studies suggest that these structures may be host-acquired, the absence of identified parasite-encoded components has hindered our understanding of their biogenesis and role in infection. Here, we applied surface shaving proteomics to profile the surface-exposed proteins of Ameson portunus -a microsporidian pathogen causing severe myopathy in portunid crabs. Our analysis identified 120 candidate surface proteins. Nineteen of these were highly enriched by both direct shaving and SDS-assisted methods, representing a high-confidence surfome. Among these, a previously uncharacterized protein, designated 8-2.11, was confirmed via immunofluorescence assay and immunoelectron microscopy. It was expressed early in development stage and specifically localized to the spore wall and hair-like projections (HLPs) of microsporidia. Notably, polyclonal antibodies against recombinant 8-2.11 recognized a native protein in spores, specifically labeled the HLP structures, and showed no cross-reactivity with host cells. Our results provide the first evidence of a parasite-encoded protein that is integral to HLP formation, challenging the prevailing hypothesis that these surface filaments are solely host-derived. This study establishes surface shaving as a powerful tool for microsporidian research and highlights 8-2.11 as a promising candidate for future functional studies on spore surface biology and host-parasite interactions.

Animals↗

PubMed2007

Reduced endothelin converting enzyme-1 and endothelin-3 mRNA in the developing bowel of male mice may increase expressivity and penetrance of Hirschsprung disease-like distal intestinal aganglionosis.

Hirschsprung disease (distal intestinal aganglionosis, HSCR) is a multigenic disorder with incomplete penetrance, variable expressivity, and a strong male gender bias. Recent studies demonstrated that these genetic patterns arise because gene interactions determine whether enteric nervous system (ENS) precursors successfully proliferate and migrate into the distal bowel. We now demonstrate that male gender bias in the extent of distal intestinal aganglionosis occurs in mice with Ret dominant-negative mutations (RetDN) that mimic human HSCR. We hypothesized that male gender bias could result from reduced expression of a gene already known to be essential for ENS development. Using quantitative real-time polymerase chain reaction (PCR) we demonstrated reduced levels of endothelin converting enzyme-1 and endothelin-3 mRNA in the male mouse bowel at the time that ENS precursors migrate into the colon. Other HSCR-associated genes are expressed at comparable levels in male and female mice. Testosterone and Mullerian inhibiting substance had no deleterious effect on ENS precursor development, but adding EDN3 peptide to E11.5 male RetDN heterozygous mouse gut explants in organ culture significantly increased the rate of ENS precursor migration through the bowel.

Animals↗

PubMed2006

BMP signaling regulates murine enteric nervous system precursor migration, neurite fasciculation, and patterning via altered Ncam1 polysialic acid addition.

The enteric nervous system (ENS) forms from migrating neural crest-derived precursors that differentiate into neurons and glia, aggregate into ganglion cell clusters, and extend neuronal processes to form a complex interacting network that controls many aspects of intestinal function. Bone morphogenetic proteins (BMPs) have diverse roles in development and influence the differentiation, proliferation, and survival of ENS precursors. We hypothesized that BMP signaling might also be important for the ENS precursor migration, ganglion cell aggregation, and neurite fasciculation necessary to form the enteric nervous system. We now demonstrate that BMP signaling restricts murine ENS precursors to the outer bowel wall during migration. In addition, blocking BMP signaling causes faster colonization of the murine colon, reduces ganglion cell aggregation, and reduces neurite fasciculation. BMP signaling also influences patterns of neurite extension within the developing bowel wall. These effects on ENS precursor migration and neurite fasciculation appear to be mediated at least in part by increased polysialic acid addition to neural cell adhesion molecule (Ncam1) in response to BMP. Removing PSA enzymatically reverses the BMP effects on ENS precursor migration and neurite fasciculation. These studies demonstrate several novel roles for BMP signaling and highlight new functions for sialyltransferases in the developing ENS.

Animals↗

PubMed2006

[Veracity of cortical somatosensory evoked potential monitoring and influencing factors in operation for cervical spondylitic myelopathy].

OBJECTIVE: To investigate the veracity of cortical somatosensory evoked potential (CSEP) and the influencing factors of manipulation of CSEP monitoring during the operation for cervical spondylitic myelopathy (CSM). METHODS: Sixty-eight CSM patients, 45 males and 23 females, aged 52.3, underwent CSEP monitoring at the ulnar, median, and posterior tibial nerves. The impact and level to CSEP of different period and manipulation during operation were recorded. The spinal cord function of post-operation were analyzed and evaluated. RESULTS: The CSEP monitoring was successful in all cases. CSEP pre-warning appeared 44 times in 24 cases. Among them 31 times of common pre-warning of CSEP were recorded because of operative manipulations and all of the 31 times of common pre-warning recovered after careful manipulation. Dangerous pre-warning was recorded for 11 times, and then the operation had to be stopped to search for the causes and awaken test was needed in one case. When the agents causing dangerous pre-warning of CSEP were found and corrected, the CSEP was able to recover. Not a patient showed aggravation of nervous function damage and no false negative result was found. CONCLUSION: CSEP can monitor the spinal cord function immediately and exactly. The main factors of operative manipulation causing pre-warning of CSEP include overextension and overflexion, overbrazing the space, operative manipulations for spinal cord thorough decompression, and overdeepening of graft.

Adult↗

PubMed2006

Differential gene expression and functional analysis implicate novel mechanisms in enteric nervous system precursor migration and neuritogenesis.

Enteric nervous system (ENS) development requires complex interactions between migrating neural-crest-derived cells and the intestinal microenvironment. Although some molecules influencing ENS development are known, many aspects remain poorly understood. To identify additional molecules critical for ENS development, we used DNA microarray, quantitative real-time PCR and in situ hybridization to compare gene expression in E14 and P0 aganglionic or wild type mouse intestine. Eighty-three genes were identified with at least two-fold higher expression in wild type than aganglionic bowel. ENS expression was verified for 39 of 42 selected genes by in situ hybridization. Additionally, nine identified genes had higher levels in aganglionic bowel than in WT animals suggesting that intestinal innervation may influence gene expression in adjacent cells. Strikingly, many synaptic function genes were expressed at E14, a time when the ENS is not needed for survival. To test for developmental roles for these genes, we used pharmacologic inhibitors of Snap25 or vesicle-associated membrane protein (VAMP)/synaptobrevin and found reduced neural-crest-derived cell migration and decreased neurite extension from ENS precursors. These results provide an extensive set of ENS biomarkers, demonstrate a role for SNARE proteins in ENS development and highlight additional candidate genes that could modify Hirschsprung's disease penetrance.

Animals↗

PubMed2006

Gadd45a interacts with aurora-A and inhibits its kinase activity.

Centrosome stability is required for successful mitosis in mammalian cells. Amplification of the centrosome leads to chromosomal missegregation and generation of aneuploidy, which are closely associated with cell transformation and tumorigenesis (Doxsey, S. J. (2001) Nat. Cell Biol. 3, E105-E108; Hinchcliffe, E. H., and Sluder, G. (2001) Genes Dev. 15, 1167-1181; Pihan, G. A., Purohit, A., Wallace, J., Malhotra, R., Liotta, L., and Doxsey, S. J. (2001) Cancer Res. 61, 2212-2219). However, there are currently limited insights into mechanism(s) for this critical biological event. Here we show that Gadd45a, a DNA damage-inducible protein that is regulated by tumor suppressors p53 and BRCA1, participates in the maintenance of centrosome stability. Mouse embryonic fibroblasts derived from gadd45a knock-out mice exhibit centrosome amplification (designated as increased centrosome numbers). Introduction of exogenous Gadd45a into mouse embryonic fibroblasts isolated from gadd45a-null mice substantially restored the normal centrosome profile. In contrast to p21(waf1/cip1), which ensures coordinated initiation of centrosome, Gadd45a had no significant effect on centrosome duplication in S phase. Interestingly Gadd45a was found to physically associate with Aurora-A protein kinase, whose deregulated expression results in centrosome abnormality. Furthermore Gadd45a was demonstrated to strongly inhibit Aurora-A kinase activity and to antagonize Aurora-A-induced centrosome amplification. These findings identify a novel mechanism for Gadd45a in the maintenance of centrosome stability and broaden understandings of p53- and BRCA1-regulated signaling pathways in maintaining genomic fidelity.

Animals↗

PubMed2006

Reduced MTA1 expression by RNAi inhibits in vitro invasion and migration of esophageal squamous cell carcinoma cell line.

To distinguish aggressive esophageal squamous cell carcinoma from indolent disease is the important clinical challenge. Studies have indicated that metastasis-associated gene 1(Mta1) played a role in the process of metastasis of carcinoma. The overexpression of Mta1 gene has been found in a variety of tumors. To identify the detailed roles of MTA1 protein in the carcinogenesis of esophageal squamous cell carcinoma, this study analyzed the pathological specimens on tissue microarray derived from 72 patients using immunohistochemistry. MTA1 expression increased in the nuclear with the development of esophageal squamous cell carcinoma from normal epithelial cell, dysplasia, to invasive cancer. In biological studies with human esophageal squamous cell carcinoma cell line, MTA1 plays its roles to promote cancer cell invasion, adhesion and movement. RNA interference (RNAi) against MTA1 decreased the malignant phenotypes. Gene microarray analysis revealed some metastasis-associated genes were altered by MTA1 RNAi. This study started an effective beginning to explore metastasis mechanisms and cancer gene therapy strategy targeting MTA1.

Base Sequence↗

PubMed2006

Administration of PUMA adenovirus increases the sensitivity of esophageal cancer cells to anticancer drugs.

Esophageal cancer is one of the most lethal human tumors, characterized by relative chemoresistance and poor prognosis. Researchers have been seeking for multimodality to improve its outcome of therapy. PUMA (p53 upregulated modulator of apoptosis) is a potent proapoptotic molecule that is rapidly induced in cells following DNA damage and is required for p53-induced apoptosis. We evaluated the therapeutic potential of PUMA adenovirus against esophageal cancer cell lines (KYSE-150, KYSE-410, KYSE-510 and YES-2). Infection with Ad-PUMA (PUMA Adenovirus) resulted in the more powerful cytotoxicity in these cell lines compared with Ad-p53. Furthermore, we assessed the efficacy of a combined treatment with Ad-PUMA and anticancer drug (cisplatin, paclitaxel, 5-fluorouracil, respectively) for these cells and found PUMA significantly increased the chemosensitivity of esophageal cancer cells, which may result from more abundant apoptosis induction. Interestingly, Ad-PUMA was found to be more efficient than Ad-p53 in inhibiting cell growth and enhancing the chemosensitivity of esophageal cancer cell lines irrespective of the p53 status. These results suggest that Ad-PUMA is a potent cytotoxic agent and could be a promising alternative in the cancer gene therapy in combination with chemotherapeutic agents.

Antineoplastic Agents↗

PubMed2006

Induction of protective and therapeutic antitumour immunity using a novel tumour-associated antigen-specific DNA vaccine.

DNA vaccination has become an attractive immunization strategy against cancer. However, a major problem of DNA vaccination is its limited potency to be taken up by the antigen-presenting cells. In contrast, loss of immunogenic epitopes of tumour cells has urged the development of vaccines against multiple epitopes. In this study, we developed a novel strategy for the APC to efficiently cross-present a fusion tumour antigen, which contains both MHC class I-restricted and class II-restricted T-cell epitopes from Her-2/neu and p53 in a cognate manner. The N-terminus of the fusion Her-2/neu, p53 protein was linked to the sequence encoding for human secondary lymphoid-tissue chemokine for secretion and chemokinesis, and the C-terminus of the fusion protein was linked to a cell-binding domain of IgG (Fc portion, the cell-binding domain of IgG) for receptor-mediated internalization. Here, we show that the introduction of fused-gene DNA vaccine by gene gun reduced the size of established tumours and prolonged the lifespan of tumour-bearing mice. Results show that this DNA vaccination strategy can broadly enhance the antigen-specific cellular and humoral immune responses. This vaccine is capable of inducing adaptive immunity and may provide a novel, generic design for the development of therapeutic and preventive DNA vaccines.

Animals↗

PubMed2006

[Expression profile of nasal NK/T cell lymphoma by cDNA microarray].

OBJECTIVE: To investigate the changes of gene expression profile in nasal NK/T cell lymphoma. METHODS: Total RNA was extracted from the fresh nasal NK/T cell lymphoma tissue and normal lymph node. Fluorescent labeled cDNA was obtained through synthesizing process by reverse transcription. After hybridization in the two identical microarrays consisting of 4096 genes, overexpressed or underexpressed tumor related genes were analyzed. RESULTS: In both experimental group and control group, there were six samples. A total of 365 (8.9%) genes was found to be differentially expressed by a factor of twofold or greater in both of two identical cDNA microarrays, which included oncogenes, tumor supressor genes, cell cycle regulators, apoptotic and antiapoptotic factors, DNA transcription factors, DNA repair and recombination factors, signal transduction genes, protein translation genes, as well as a large number of metabolic genes. Thirty-seven of these genes were found to be differentially expressed by a factor of fourfold or greater. The biochemical functions of these differentially expressed genes were diverse. CONCLUSION: This study demonstrates that many different kinds of genes are possibly involved in the initiation and progression of nasal NK/T lymphoma. cDNA microarray technique is useful in screening cancer gene expression for nasal NK/T lymphoma.

Antigens, CD20↗

PubMed2005

Population differences in the polyalanine domain and 6 new mutations in HLXB9 in patients with Currarino syndrome.

BACKGROUND: The combination of partial absence of the sacrum, anorectal anomalies, and presacral mass constitutes Currarino syndrome (CS), which is associated with mutations in HLXB9. METHODS: We analyzed 5 CS families and 6 sporadic cases for HLXB9 mutations by direct sequencing. Potentially pathologic expansions of HLXB9 GCC repeats were analyzed in patients, 4 general populations [Chinese, Japanese, Yoruba, and Centre du Etude Polymorphisme Human (CEPH)] from the HapMap project, and 145 healthy Chinese. RESULTS: We identified 6 novel mutations affecting highly conserved residues (Ser185X, Trp215X, Ala26fs, Ala75fs, Met1Ile, and Arg273Cys). GCC allele and genotype distributions showed marked statistically significant differences. (GCC)11 was the most common allele overall; its frequency ranged from 90% in CEPH to 68% in Yoruba and 50% in Chinese and Japanese populations. (GCC)9 was almost as common as (GCC)11 in Chinese and Japanese populations, whereas its frequency was <10% in Yoruba and CEPH populations. The Yoruba population had the highest frequency of the largest alleles [(GCC)12 and (GCC)13], which were almost absent in the other groups. CONCLUSIONS: Lack of HLXB9 mutations in some patients and the presence of variable phenotypes suggest DNA alterations in HLXB9 noncoding regions and/or in other genes encoding HLXB9 regulatory molecules or protein partners. If HLXB9, like other homeobox genes, has a threshold beyond which triplet expansions are pathologic, those populations enriched with larger alleles would be at a higher risk. The data illustrate the importance of ethnicity adjustment if these polymorphic markers are to be used in association studies.

Abnormalities, Multiple↗

PubMed2005

Optical properties of transparent copper nanorod and nanowire arrays embedded in anodic alumina oxide.

Transparent copper nanorod/nanowire arrays and anodic alumina oxide composite films have been prepared by alternating current electrodeposition, and their linear optical properties have been systematically characterized by absorption spectra. In the experimental spectra, there exist transverse and longitudinal resonance peaks, which are caused by the surface-plasmon resonance along the diameter and the length of the copper nanorods, respectively. The transverse resonance peak is affected by the diameter and aspect ratio of the nanorod. The longitudinal resonance peak appears at longer wavelength when a polarized light illuminates the film with an angle of incidence of about 70 degrees , where the angle is defined with respect to the surface normal. Moreover, the longitudinal resonance mode is sensitive to the polarization direction when compared with the transverse resonance mode.

Journal Article↗

PubMed2005

Pharmacokinetic and cytotoxic studies of pegylated liposomal daunorubicin.

Pegylated liposomes have been studied for nearly two decades. However, fewer pharmacological studies about its application in daunorubicin (DNR) than those in doxorubicin have been reported. In order to conduct a complete pharmacokinetic study, radiolabeled DNR was encapsulated in pegylated liposomes. Its in vitro drug release kinetics was determined to be in a slow manner, which was reflected in its cytotoxic effect on four cell lines. The lethal dose, plasma pharmacokinetics as well as tissue distribution of the formulation were evaluated in comparison with free DNR. The results revealed that liposomal daunorubicin significantly reduced the toxicity of the drug, with a half lethal dose of 29.35 mg/kg, compared with 5.45 mg/kg for free drug. Pharmacokinetic study of liposomal DNR demonstrated a slower clearance rate, an elevated area under the concentration-time curve, as well as increased half-lives compared to free drug. In addition, an altered tissue distribution of liposomal DNR was observed, with lower cardiac accumulation. Taken together, pegylated liposome-loaded DNR may be a promising anticancer drug and worth further therapeutic study.

Animals↗

PubMed2005

B23 regulates GADD45a nuclear translocation and contributes to GADD45a-induced cell cycle G2-M arrest.

Gadd45a is an important player in cell cycle G2-M arrest in response to genotoxic stress. However, the underlying mechanism(s) by which Gadd45a exerts its role in the control of cell cycle progression remains to be further defined. Gadd45a interacts with Cdc2, dissociates the Cdc2-cyclin B1 complex, alters cyclin B1 nuclear localization, and thus inhibits the activity of Cdc2/cyclin B1 kinase. These observations indicate that Gadd45a nuclear translocation is closely associated with its role in cell cycle G2-M arrest. Gadd45a has been characterized as a nuclear protein, but it does not contain a classical nuclear localization signal, suggesting that Gadd45a nuclear translocation might be mediated through different nuclear import machinery. Here we show that Gadd45a associates directly with B23 (nucleophosmin), and the B23-interacting domain is mapped at the central region (61-100 amino acids) of the Gadd45a protein using a series of Myc tag-Gadd45a deletion mutants. Deletion of this central region disrupts Gadd45a association with B23 and abolishes Gadd45a nuclear translocation. Suppression of endogenous B23 through a short interfering RNA approach disrupts Gadd45a nuclear translocation and results in impaired Gadd45a-induced cell cycle G2-M arrest. These findings demonstrate a novel association of B23 and Gadd45a and implicate B23 as an important regulator in Gadd45a nuclear import.

Active Transport, Cell Nucleus↗

PubMed2005

Hoxb3 vagal neural crest-specific enhancer element for controlling enteric nervous system development.

The neural and glial cells of the intrinsic ganglia of the enteric nervous system (ENS) are derived from the hindbrain neural crest at the vagal level. The Hoxb3 gene is expressed in the vagal neural crest and in the enteric ganglia of the developing gut during embryogenesis. We have identified a cis-acting enhancer element b3IIIa in the Hoxb3 gene locus. In this study, by transgenic mice analysis, we examined the tissue specificity of the b3IIIa enhancer element using the lacZ reporter gene, with emphasis on the vagal neural crest cells and their derivatives in the developing gut. We found that the b3IIIa-lacZ transgene marks only the vagal region and not the trunk or sacral region. Using cellular markers, we showed that the b3IIIa-lacZ transgene was expressed in a subset of enteric neuroblasts during early development of the gut, and the expression was maintained in differentiated neurons of the myenteric plexus at later stages. The specificity of the b3IIIa enhancer in directing gene expression in the developing ENS was further supported by genetic analysis using the Dom mutant, a spontaneous mouse model of Hirschsprung's disease characterized by the absence of enteric ganglia in the distal gut. The colonization of lacZ-expressing cells in the large intestine was incomplete in all the Dom/b3IIIa-lacZ hybrid mutants we examined. To our knowledge, this is the only vagal neural crest-specific genetic regulatory element identified to date. This element could be used for a variety of genetic manipulations and in establishing transgenic mouse models for studying the development of the ENS.

Animals↗

PubMed2005

Angiogenesis inhibitor Z24 induces endothelial cell apoptosis and suppresses tumor growth and metastasis.

Z24, a small molecular compound with similar chemical structure to SU5416 designed and synthesized by our lab, has been proved to be an angiogenesis inhibitor. In this study, Z24 was shown to induce human umbilical venous endothelial cell (HUVEC) apoptosis confirmed by morphologic changes including the presence of apoptotic bodies, significant apoptotic sub-G1 peak upon flow-cytometric analysis, formation of DNA ladders upon agarose gel electrophoresis, and TUNEL (TdT mediated X-dUTP nick-end labeling) results. Systemic administration of Z24 at non-toxic dose in nude mice resulted in inhibition of subcutaneous tumor growth of human colon cancer HCT-8, while it did not inhibit this cell line in vitro, with 100-fold more potent growth-inhibition against endothelial cells. The immunohistochemical results showed that the microvessel density of tumor tissue of the Z24 group was significantly lower than that of the control groups (P<0.05), which supported its anti-angiogenic property. We further found that Z24 inhibited the pulmonary metastasis of mouse lung adenocarcinoma LA795, with fewer surface lung metastases (89.6%, P<0.0001) and decreased lung weights (38.5%, P<0.01) compared to the vehicle group. All these findings support that Z24 is a promising angiogenesis inhibitor for limiting tumor growth and metastasis.

Angiogenesis Inhibitors↗

PubMed2005

[The mechanism of resistance to 2', 2'-difluorodeoxycytidine (gemcitabine) in a pancreatic cancer cell line].

OBJECTIVE: To study the mechanism of resistance and its reversal to 2', 2'-difluorodeoxycytidine (gemcitabine) in a pancreatic cancer cell line SW1990. METHODS: Immunohistochemistry and RT-PCR techniques were used to investigate the mechanism of drug resistance. Salvicine (SAL) was used to reverse the drug resistance in a gemcitabine-resistant pancreatic cancer cell line (SW1990-GEM). RT-PCR, flow cytometry and MTT assay were employed to evaluate the effect of reversing drug resistance by salvicine. RESULTS: SW1990-GEM cells showed weak expression of P-glycoprotein (P-gp) revealed by immunohistochemistry, while its parental SW1990 cells were negative. Both cell lines did not express multidrug-resistance-related protein (MRP). As compared to the parental SW1990 cells, the mRNA expression of deoxycytidine kinase (dCK) was decreased while that of ribonucleotide reductase (RR) and mdr-1 was increased. With a concentration of 4 nmol/L, at one hr and 24 hr after SAL treatment, there was no change in mdr-1 mRNA expression, and the IC(50) of gemcitabine was 121.36 micromol/L and 121.64 micromol/L, respectively. However, when the concentration of SAL was increased to 30, 60, and 90 nmol/L, there was a dose-dependent down-regulation of mdr-1 mRNA expression in SW1990-GEM cells. The accumulation of rhodamine 123 was concomitantly increased, and the IC(50) of gemcitabine was correspondingly decreased. CONCLUSION: The resistance to gemcitabine of a pancreatic cancer cell line is due to decreased expression of dCK and increased expression of RR and mdr-1. Salvicine, only in toxic concentrations, can reverse the drug resistance by down-regulating mdr-1 gene and P-gp expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

TTF-1 and RET promoter SNPs: regulation of RET transcription in Hirschsprung's disease.

Single nucleotide polymorphisms (SNPs) of the coding regions of receptor tyrosine kinase gene (RET) are associated with Hirschsprung's disease (HSCR, aganglionic megacolon). These SNPs, individually or combined, may act as a low penetrance susceptibility locus and/or be in linkage disequilibrium (LD) with another susceptibility locus located in RET regulatory regions. Because two RET promoter SNPs have been found associated with HSCR, in LD with HSCR-associated RET coding region haplotypes, their implication in the transcriptional regulation of RET is of major interest. Analysis of 172 sporadic HSCR patients also revealed the presence of HSCR-associated RET promoter SNPs in LD with the main coding region RET haplotype observed in Chinese patients. By using a weighted logistic regression approach, we determined that of all SNPs tested in our study, the promoter SNPs are the most correlated to the disease. Functional analysis of the RET promoter SNPs in the context of additional 5' regulatory regions demonstrated that the HSCR-associated alleles decrease RET transcription. These SNPs overlap a TTF-1 binding site and TTF-1-activated RET transcription is also decreased by the HSCR-associated SNPs. Moreover, we identified an HSCR patient with a Gly322Ser TTF-1 mutation that compromises activation of transcription from HSCR-associated RET promoter haplotypes. Interestingly, we show that the pattern of RET and TTF-1 expression is coincident in developing human gut. We also present a detailed profile of the RET gene in our population, which provides an insight into the higher incidence of the disease in China.

Alleles↗