Biomedical subjects

Xiansheng Zhang

Publications and source records attributed to Xiansheng Zhang.

7 recordsLinked to original sources

PubMed2024

Diverse phenotypes and fertility outcomes of patients with androgen insensitivity syndrome in a Chinese family harboring identical AR gene variant.

BACKGROUND: Androgen insensitivity syndrome (AIS) is a rare genetic disorder characterized by resistance to androgens, mainly due to mutations in the androgen receptor (AR) gene. It can manifest as complete AIS, partial AIS and mild AIS. While there have been studies linking specific AR gene mutations to AIS phenotypes, different clinical AIS phenotypes are also reported in patients with the same AR gene mutation. So far, the precise correlations between phenotypes and genotypes remain incompletely understood. METHODS: We conducted a thorough investigation involving four patients diagnosed with different types of AIS from a single Chinese family. Clinical manifestations, laboratory examinations, and fertility outcomes were well-documented. Furthermore, we performed genetic sequencing to detect possible pathogenetic variants. RESULTS: Whole exome sequencing identified a hemizygous missense variant (c.2263T > C; p.Phe755Leu) of AR gene in all four affected patients with different degrees of undermasculinisation and heterogeneous spermatogenesis. The proband, diagnosed with partial AIS, opted for treatment with donated sperm due to non-obstructive azoospermia, while their older sibling, diagnosed with complete AIS, was raised as a girl. His two maternal uncles were both diagnosed with mild AIS, the older uncle fathered two girls naturally, whereas the younger uncle utilized assisted reproductive technology to conceive a boy because of severe oligoasthenozoospermia. CONCLUSION: Our study first identified the same AR variant (c.2263T > C;p.Phe755Leu) in four affected patients displaying highly diverse phenotypes of AIS and fertility outcomes, thereby significantly expanding the phenotypic spectrum of AIS. Notably, we presented a clear insight into different fertility outcomes of AIS patients with identical AR (c.2263T > C;p.Phe755Leu) variant, which provided reliable evidence that males harboring this variant may obtain biological offspring naturally or in combination with assisted reproductive technology. Furthermore, our study underscored the potential role of androgen concentration in shaping the phenotypic diversity of AIS, warranting further investigation.

Adult↗

PubMed2006

Knockout of the AtCESA2 gene affects microtubule orientation and causes abnormal cell expansion in Arabidopsis.

Complete cellulose synthesis is required to form functional cell walls and to facilitate proper cell expansion during plant growth. AtCESA2 is a member of the cellulose synthase A family in Arabidopsis (Arabidopsis thaliana) that participates in cell wall formation. By analysis of transgenic seedlings, we demonstrated that AtCESA2 was expressed in all organs, except root hairs. The atcesa2 mutant was devoid of AtCESA2 expression, leading to the stunted growth of hypocotyls in seedlings and greatly reduced seed production in mature plants. These observations were attributed to alterations in cell size as a result of reduced cellulose synthesis in the mutant. The orientation of microtubules was also altered in the atcesa2 mutant, which was clearly observed in hypocotyls and petioles. Complementary expression of AtCESA2 in atcesa2 could rescue the mutant phenotypes. Together, we conclude that disruption of cellulose synthesis results in altered orientation of microtubules and eventually leads to abnormal plant growth. We also demonstrated that the zinc finger-like domain of AtCESA2 could homodimerize, possibly contributing to rosette assemblies of cellulose synthase A within plasma membranes.

Amino Acid Sequence↗

PubMed2005

Comparison of surgical stress between laparoscopic and open appendectomy in children.

PURPOSE: The present study aimed to evaluate laparoscopic appendectomy (LA) in comparison with conventional open appendectomy (OA) in children, with special emphasis on the extent of surgical trauma after LA and OA, and to assess whether LA had any clear advantages compared with conventional OA. METHODS: A total of 160 patients with a median age of 7.9 years (range 3-15 years) were studied. Sixty-nine of them underwent LA, and the remaining 91 underwent OA. Serum interleukin (IL) 6 and C-reactive protein (CRP) levels which are thought to play a pivotal role in the pathogenesis of surgical trauma and can also be used to monitor the magnitude of surgical trauma were measured using an enzyme-linked immunosorbent assay before surgery and 12 hours after surgery. In addition, we compared operating time, hospital stay, incidence of wound infection, and incidence of intra-abdominal infection. RESULTS: The operative time of normal and suppurative appendix in the laparoscopic group was significantly shorter than that in the open group, respectively, but the operative time of gangrenous appendix was not different between the laparoscopic group and open group. The hospital stay in the laparoscopic group was also significantly shorter than that in the open group. Postoperatively, 1 patient had port-site infection in the laparoscopic group, whereas 10 had wound infection in the open group; this difference was highly significant (chi2 = 4.19, P < .05). Three patients in the open group and 2 patients in the laparoscopic group had intra-abdominal infection, and the difference had no statistically significant difference (chi2 = 0.10, P < .05). Preoperative IL-6 levels were not different between the 2 groups, but the rise (preoperative vs postoperative) of IL-6 in the laparoscopic group was remarkably less than that in the open group. Similar results were obtained for CRP; serum CRP levels in the basal state were not different between the 2 groups, but the rise (preoperative vs postoperative) of CRP in the laparoscopic group was also substantially less compared with that in the open group. CONCLUSIONS: LA for children was as safe and effective as the open procedure and had significant advantages over OA because of less operating time, less postoperative complications, less surgical trauma, and more rapid postoperative recovery.

Adolescent↗

PubMed2004

Role of urokinase plasminogen activator and its receptor in metastasis and invasion of neuroblastoma.

BACKGROUND/PURPOSE: Urokinase plasminogen activator (uPA) is a serine proteinase that has been suggested to play an important role in tumor invasion and metastasis. It binds to a specific membrane receptor, uPA receptor (uPAR), and activates plasminogen to form plasmin, which participates in tissue degradation and proteolysis. Binding of uPA to its receptor accelerates the activation of uPA from pro-uPA, enhancing the activity of the uPA/uPAR cascade. Because of the high metastatic and invasive potential of neuroblastoma (NB) cells, the authors have analyzed in the current study, the concomitant of uPA and its receptor in NB. METHODS: The expression and distribution of uPA and uPAR were analyzed by immunostaining in 52 neuroblastoma tissues; at the same time we use the reverse transcriptase polymerase chain reaction (RT-PCR) for neuroendocrine protein gene products 9.5 (PGP 9.5) mRNA to detect small numbers of NB cells in the peripheral blood and bone marrow (BM) and study the relationship uPA and uPAR to the ability of invasion and metastasis of NB cells. To identify risk factors for disease progression, the authors performed a retrospective analysis of clinical (age, sex, and risk group) and tumor biologic markers (histology, MYCN, DNA ploidy, chromosome 1 p, PGP9.5, uPA, uPAR, and combined uPA and uPAR) in all patients. Survival curves were estimated using the Kaplan-Meier method. Univariate analysis was performed with the log-rank test. Multivariate analysis was performed using the Cox proportional hazards regression model. RESULTS: The results of immunohistochemistry showed that uPA and uPAR were localized mainly in the membrane and cytoplasm of tumor cells. The positive rate of uPA in the high-risk group (23 of 25, 92.0%) was remarkably higher than that in intermediate-risk group (8 of 17, 47.1%) and low-risk group (3 of 10, 30.0%), in UH (26 of 29, 89.7%) was higher than in FH (8 of 23, 34.8%), respectively, and statistical significance was remarkable both P < .01). Similar results were obtained for uPAR. The positive rate of uPAR in the high-risk group (22 of 25, 88.0%) was substantially higher compared with that in intermediate-risk group (6 of 17, 35.3%) and low-risk group (2 of 10, 20.0%; P < .01). The positive rate of uPAR in UH (24 of 29, 82.8%) was higher compared with that in FH (6 of 23, 26.1%), and statistical significance was remarkable (P < .01). PGP9.5 mRNA in peripheral blood and BM was detected in 24 of 52 (45.2%) patients. The positive rate of PGP 9.5 mRNA in peripheral blood and BM in the cases positive for uPA (22 of 34, 64.7%) was markedly higher than that in the cases negative for uPA (11.1%, 2 of 18), and statistical significance was remarkable (P < .01). There was significant difference in the positive rate of PGP9.5 mRNA between the group positive for uPAR (66.7%, 20 of 30) and the group negative for uPAR (18.2%, 4 of 22), and a larger difference was found between the group positive for both uPA and uPAR (73.1%, 19 of 26) and the group negative for uPA or uPAR (19.2%, 5 of 26). The overall survival (OS) and event-free survival (EFS) rates at 5 years for all patients were, respectively, 70% +/- 3% and 63% +/- 3% with a median follow-up of 65 months (range 13 to 20). Among all the biologic and clinical features analyzed, multivariate analysis using Cox proportional hazards regression showed that age, MYCN, and combined uPA and uPAR remained significant predictors for both OS and EFS (P < .01, respectively). Both EFS rate and OS rate were significantly better for patients who positively expressed uPA and uPAR than those who negatively expressed uPA or uPAR. CONCLUSIONS: This study showed that uPA and uPAR were overexpressed in high-risk and UH tumor of NB, and that overexpression of both factors was associated with the ability of invasion, metastasis, and prognosis of NB. The presence of high levels of combined uPA and uPAR may be a new prognostic marker that would allow us to identify patients with poorer prognosis who might benefit from more aggressive surgical and adjuvant treatment.

Biomarkers, Tumor↗

PubMed2004

Monitoring of gene expression profiles and isolation of candidate genes involved in pollination and fertilization in rice ( Oryza sativa L.) with a 10K cDNA microarray.

To monitor gene expression profiles during pollination and fertilization in rice at a genome scale, we generated 73,424 high-quality expressed sequence tags (ESTs) derived from the green/etiolated shoot and pistil (0-5 h after pollination, 5hP) of rice, which were subsequently used to construct a cDNA microarray containing ca. 10 000 unique rice genes. This microarray was used to analyze gene expression in pistil unpollinated (UP), 5hP and 5DAP(5 days after pollination), anther, shoot, root, 10-day-old embryo (10EM) and 10-day-old endosperm (10EN). Clustering analysis revealed that the anther has a gene-expression profile more similar to root than to pistil and most pistil-preferentially expressed genes respond to pollination and/or fertilization. There are 253 ESTs exhibiting differential expression (e +/- 2-fold changes) during pollination and fertilization, and about 70% of them can be assigned a putative function. We also recovered 20 genes similar to pollination-related and/or fertility-related genes previously identified as well as genes that were not implicated previously. Microarray and real-time PCR analyses showed that the array sensitivity was estimated at 1-5 copies of mRNA per cell, and the differentially expressed genes showed a high correlation between the two methods. Our results indicated that this cDNA microarray constructed here is reliable and can be used for monitoring gene expression profiles in rice. In addition, the genes that differentially expressed during pollination represent candidate genes for dissecting molecular mechanism of this important biological process in rice.

Cluster Analysis↗

PubMed2004

Sequencing and analysis for the full-length genome RNA of foot-and-mouth disease virus China/99.

The complete nucleotide sequence of genomic RNA of foot and mouth disease virus (FMDV) strain China/99 from infected bovine tongue epithelium is presented. The nucleotide sequence extending from the 5' end of the genomic RNA to the 5' end of poly (A) tail contains 8173 nucleotides (nt). Its open reading frame, which encodes a single polypeptide of 2332 amino acids, encompasses 6999 nt starting from the initiation codon AUG and terminating at the UAA codon 93 bases upstream from the 5' end of poly (A) tract. The 5' untranslated region (UTR) is composed of 1081 nt. The consensus of the 1d gene of FMDV strain China/99 compared with that of UKG/6/2001, UKG/12/2001, China/99HN4 and China/3/Tibet is over 97%. The result showed the stains belong to the members of the Pan-Asia family. There is a remarkable differentiation in the function-unknown (FUR), p2 and p3 regions between FMDV isolates from infected cattle and swine, especially in 3a gene. No deletion was found in genes I, 1a, 1b, 2a, 2c, 3b, and 3d. These genes might be indispensable to the surviving of FMDV. The secondary structures of small (S) fragments, FUR and an internal ribosome entry site can be classified into three types, and the S fragment and 3' UTR of the positive-sense RNA fold into stem-loop structures similar to the shape of clover.

Animals↗

PubMed2004

[Applied study on small-dose growth hormone supplement for aging-related symptom complex].

OBJECTIVE: To assess the response of aging-related symptom complex to small-dose supplement of growth hormone. METHODS: Thirty patients, aged 42 to 77, with aging-related symptom complex and normal serum testosterone were studied. Each subject received growth hormone at the dosage of 0.04 U/kg, 3 times/week for six months. Before and after treatment, body weight, grip strength, abdomen circumference, IPSS, uroflow rate, prostate volume, serum testosterone, cholesterol, triglyceride, PSA, IGF-1, glucose and side effects were determined in every case. Self Rating Scale used by Bosphorus university was adopted. RESULTS: After the treatment, the rating scores were significantly improved, grip strength and serum level of IGF-1 increased, and abdomen circumference and serum cholesterol decreased. Whereas, IPSS, uroflow rate, prostate volume, serum testosterone, triglyceride, PSA, glucose and body weight were not significantly changed. CONCLUSION: Six months treatment with small-dose growth hormone can improve aging-related symptom complex with little adverse effect.

Adult↗