PubMed Health⌕ Search

Biomedical subjects

Peng Wei

Publications and source records attributed to Peng Wei.

At least 19 recordsLinked to original sources
PubMed2026

highSpaClone enables copy number alteration inference and tumor subclone analysis for high-resolution spatial transcriptomics.

High-resolution spatially resolved transcriptomics (SRT) offers unprecedented opportunities to investigate tumor heterogeneity but poses substantial computational and analytical challenges. Here, we present highSpaClone, a computational framework for copy number alteration (CNA) inference and tumor subclone identification from high-resolution SRT data across multiple spatial scales. By integrating spatial constraints into CNA estimation and clonal clustering, highSpaClone enables neighboring spatial locations to share information, thereby improving the robustness of genomic signals and the accuracy of subclone delineation. Across multiple Xenium and Visium HD datasets, highSpaClone revealed unique transcriptional programs, clonal evolutionary trajectories, and distinct tumor-microenvironment interactions. Furthermore, in human colorectal cancer samples, highSpaClone detected CNA events in histologically normal epithelial regions, highlighting early genomic alterations associated with field cancerization. These findings establish highSpaClone as a scalable framework for studying clonal architecture and tumor evolution.

CP: cancer biology↗
PubMed2006

Dose-related actions of GnRH II analog in the cycling rhesus monkey.

INTRODUCTION: Gonadotropin-releasing hormone (GnRH) II expression, specific high-affinity receptors for GnRH II and its potent bioactivity in human and baboon tissues led us to hypothesize that GnRH II is a bioactive peptide in primates. We recently demonstrated the contraceptive activity of GnRH II analog in rhesus monkeys. In the present experiment, we extended those studies to the dose-related action of this analog on parameters of luteal function and conception. METHODS: GnRH II analog (0-32 microg/day) or saline was administered via osmotic minipumps for 6 days (Days 1-6 postovulation) to regularly cycling rhesus monkeys mated with fertile males around the time of ovulation. Cycle dynamics was monitored through circulating luteinizing hormone, progesterone and estradiol. Pregnancy was determined by circulating chorionic gonadotropin concentrations. RESULTS: Progesterone production (Days 3-11) was significantly less (p<.05) for animals treated with 2, 4 or 8 microg/mL GnRH II analog than for controls, yet with higher doses of GnRH II analog (i.e., 16 or 32 microg/day), luteal progesterone was not different from that of saline-treated controls. The length of the luteal phase in all treated groups was similar to that of controls. In 18 animals mated at the time of ovulation and then treated with GnRH II analog (2-32 microg/day), no pregnancies resulted. In saline-treated controls, five of eight animals (62.5%) became pregnant. Thus, the contraceptive activity of this GnRH II analog did not correlate with luteal progesterone inhibition. CONCLUSIONS: These data demonstrate a dose-related action of GnRH II analog on luteal progesterone and establish the contraceptive activity of 2-32 microg/day GnRH II analog administered postovulation.

Animals↗
PubMed2006

Temporal and spatial expression of MMP-2, -9, -14 and their inhibitors TIMP-1, -2, -3 in the corpus luteum of the cycling rhesus monkey.

The corpus luteum (CL) is a transient endocrine organ that secretes progesterone to support early pregnancy. If implantation is unsuccessful, luteolysis is initiated. Extensive tissue remodeling occurs during CL formation and luteolysis. In this study, we have studied the possible involvement of MMP-2, -9, -14, and their inhibitors, TIMP-1, -2, -3 in the CL of cycling rhesus monkey at various stages by in situ hybridization, immunohistochemistry and microscopic assessment. The results showed that the MMP-2 mRNA and protein were mainly expressed in the endothelial cells at the early and middle stages of the CL development, while their expressions were observed in the luteal cells at the late stage during luteal regression. MMP-9 protein was detected in the CL at the early and middle stages, and obviously increased at the late stage. The expressions of MMP-14 and TIMP-1 mRNA were high at the early and late stages, and low at the middle stage. TIMP-2 mRNA was high throughout all the stages, the highest level could be observed at the late stage. The TIMP-3 production was detected throughout all the stages, but obviously declined during CL regression. MMP-9, -14 and TIMP-1, -2, -3 were mainly localized in the cytoplasm of the steroidogenic cells. The results suggest that the MMP/TIMP system is involved in regulation of CL development in the primate, and the coordinated expression of MMP-2, -14 and TIMP-1, -3 may have a potential role in the CL formation and the functional maintaining, while the interaction of MMP-2, -9, -14 and TIMP-1, -2, -3 might also play a role in CL regression at the late stage of CL development in the primate.

Animals↗
PubMed2006

Combining gene annotations and gene expression data in model-based clustering: weighted method.

It has been increasingly recognized that incorporating prior knowledge into cluster analysis can result in more reliable and meaningful clusters. In contrast to the standard modelbased clustering with a global mixture model, which does not use any prior information, a stratified mixture model was recently proposed to incorporate gene functions or biological pathways as priors in model-based clustering of gene expression profiles: various gene functional groups form the strata in a stratified mixture model. Albeit useful, the stratified method may be less efficient than the global analysis if the strata are non-informative to clustering. We propose a weighted method that aims to strike a balance between a stratified analysis and a global analysis: it weights between the clustering results of the stratified analysis and that of the global analysis; the weight is determined by data. More generally, the weighted method can take advantage of the hierarchical structure of most existing gene functional annotation systems, such as MIPS and Gene Ontology (GO), and facilitate choosing appropriate gene functional groups as priors. We use simulated data and real data to demonstrate the feasibility and advantages of the proposed method.

Algorithms↗
PubMed2006

[Treatment of complex acetabular fractures by a modified extended iliofemoral approach].

OBJECTIVE: To evaluate the effect of the modified extended iliofemoral approach on treating complex acetabular fractures. METHODS: Thirty-six cases of complex acetabular fractures were treated by the open reposition and internal fixation by a modified extended iliofemoral approach. RESULTS: Thirty-six cases were followed up for 7-46 months, with an average of 23.8 months. According to the Matta standard, anatomical reposition was performed in 24 cases, perfect reposition in 8 cases, and unsatisfactory reposition in 4 cases. By the modified d'Aubigne-postel score, among the 36 cases, 22 had an excellent result, 9 had a good result, and 5 had a poor result. CONCLUSION: The modified extended iliofemoral approach facilitates the operative exposure of the anterior and posterior walls and both columns of the acetabulum in the surgically-treated acetabular fractures by the open reposition and internal fixation. Because of the reconstruction, the functions of the abductor muscle mass managed by the lag-screw-fixed osteotomies of the iliac crest, and greater trochanter, the patients can achieve a rapid rehabilitation of the joint.

Acetabulum↗
PubMed2005

Dedifferentiation of adult monkey Sertoli cells through activation of extracellularly regulated kinase 1/2 induced by heat treatment.

Sertoli cells play a key role in triggering and regulating the process of spermatogenesis. Failure of a Sertoli cell to mature functionally will presumably render it incapable of supporting germ cell survival and development that appeared after puberty. Expression of cytokeratin 18 (ck-18) intermediate filaments indicates a state of undifferentiation usually observed in Sertoli cells of prepubertal testis. In this study we demonstrated that local testicular heat treatment of adult monkey with water at 43 C for 30 min once daily for 2 consecutive days was capable of activating reexpression of ck-18 in Sertoli cells, which was coincident with activation of ERK1/2 and Akt kinases. Using primary Sertoli cell culture isolated from adult monkey testis, we further confirmed that the heat treatment of the cells at 43 C could also induce ck-18 reexpression, which was similar to the in vivo treatment. ERK MAPK was also induced by the heat treatment in a time- and protein kinase A (PKA)-dependent manner. After blocking the ERK MAPK signaling pathway, an inhibition of ck-18 expression in the cultured Sertoli cells was observed, and this inhibitory effect was also detected by blocking the PKA activation. However, ck-18 activation in Sertoli cells remained unaltered when the phosphatidylinositol 3-kinase/Akt pathway was blocked. In conclusion, the heat treatment of adult monkey Sertoli cells are capable of inducing a reversible change in the Sertoli cells from an adult differentiated state to an immature-like dedifferentiated state through PKA-ERK MAPK-dependent pathways but not via the phosphatidylinositol 3-kinase/Akt pathway.

Animals↗
PubMed2005

Synthesis of triphenylamine-cored dendritic two-photon absorbing chromophores.

[structure: see text]. A new series of dendritic two-photon absorbing chromophores containing triphenylamine moiety as a core or branching points have been synthesized through a convergent synthetic strategy. One-photon and two-photon optical properties of these molecules were characterized. In the nanosecond time domain, these molecules exhibited large two-photon absorption (TPA) cross sections up to 7.56-12.2 x 10(-44) s cm(4) at 800 nm, indicating that these molecular structures were viable candidates for various two-photon related applications.

Journal Article↗
PubMed2005

Factors affecting stereocontrol during glycosidation of 2,3-oxazolidinone-protected 1-tolylthio-N-acetyl-D-glucosamine.

[reaction: see text] It is demonstrated that a ring-fused 2,3-oxazolidinone-protected derivative of 1-tolylthio-N-acetyl-D-glucosamine undergoes high-yield glycosidation under mild donor activation conditions. Stereoselective formation of alpha-linked or beta-linked glycosides is dependent on reactivity of acceptor alcohols, where rate of glycosidation correlates to stereochemical outcome. Evidence for the role of glycosyl triflate intermediates and the N-acetyl substituent of the 2N,3O-oxazolidinone ring in stereochemical control is presented.

Glucosamine↗
PubMed2005

Expression of Bcl-2 and p53 at the fetal-maternal interface of rhesus monkey.

To study the apoptosis and its mechanism at the fetal-maternal interface of early gestation, localization of apoptotic cells in the implantation sites of the rhesus monkey on day 17, 19, 28 and 34 of pregnancy were first examine by using the TUNEL technique. The expression of Ki67, a molecular marker of proliferating cells, and two apoptotic proteins, B cell lymphoma/leukaemia-2 (Bcl-2) and P53, were then studied by immunohistochemistry. Apoptotic nuclei were observed mainly in the syncytiotrophoblast. Ki67 was confined almost exclusively to cytotrophoblasts. The localization of Bcl-2 protein follows that of the apoptotic nuclei and its expression level increased as the development of the placenta progressed on. P53 was detected to some extent in cytotrophoblasts and syncytiotrophoblast covering the basal feet of the anchoring villi during the late stage of placentation. Based on these observations, it might be suggested that Bcl-2 could be possible to play an interesting role in limiting degree of nuclear degradation and sustaining cell survival in the multi-nucleated syncytiotrophoblast cells during early pregnancy, and P53 could also be essential in regulating the trophoblastic homeostasis by controlling its proliferation or apoptosis.

Animals↗
PubMed2005

Anti-apoptotic action of stem cell factor on oocytes in primordial follicles and its signal transduction.

Stem cell factor (SCF) is essential for the development of primordial follicles. One of its functions is to prevent oocytes from apoptosis. However, the underlying mechanism remains largely unknown. By using cultured ovaries that are rich in primordial follicles, the anti-apoptotic action of SCF and the potential signal transduction pathways were investigated. The apoptosis was evaluated by means of in situ 3'-end labeling. The expressions of proteins were analyzed with immunohistochemistry and Western blot. The data showed that SCF significantly prevented oocytes from apoptosis in the cultured organs. Addition of a specific pharmacological inhibitor of PI3K abolished the anti-apoptotic action of SCF while that of a MEK inhibitor did not. The phosphorylation of two mitogen activated protein kinases (MAPKs) (p42 and p44) and AKT, the respective substrates of MEK and PI3K, were enhanced by SCF treatment. Not surprisingly, the MAPK activation occurred only in theca cells. The expressions of apoptosis-related gene products, the Bcl-2 family proteins, in response to SCF treatment were also investigated. While SCF up-regulated the expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL, it did the opposite to the pro-apoptotic factor Bax. The PI3K inhibitor reversed the regulation of SCF on Bcl-xL and Bax but not on Bcl-2. Therefore, it seemed that SCF initiated an anti-apoptotic signal starting from its membrane receptor c-kit to Bcl-2 family members through PI3K/AKT and other signaling cascades in the oocytes of primordial follicles.

Animals↗
PubMed2005

Fas, FasL, Bcl-2, and Bax in the endometrium of rhesus monkey during the menstrual cycle.

To study possible role and regulation of apoptosis occurred in primate endometrium, the expression of apoptosis-related molecules, Fas, FasL, B cell lymphoma/leukaemia-2 (Bcl-2), and Bax were analyzed in relation to occurrence of apoptosis and proliferation in the cycling endometrium of the rhesus monkey using immunohistochemistry and Western blot. The cell apoptosis and proliferation were evaluated by means of in situ 3'-end labeling and Ki67 immunostaining, respectively. The results showed that the expressions of Fas, Fas ligand (FasL), Bcl-2, and Bax were co-localized predominantly in the epithelial cells of the endometrium. Modest Fas staining with no obvious change was detected throughout the menstrual cycle, while the levels of FasL and Bax protein in the epithelial cells increased in the secretory phase when apoptosis was most prevalent. In contrast, epithelial immunostaining for Bcl-2 was maximal during the proliferative phase and decreased in the secretory phase. Bcl-2 immunoreactivity was also detected in some immunocytes. The coordinated expression of Fas, FasL, Bcl-2, and Bax in the cycling endometrium of the rhesus monkey suggests that the cyclic changes in endometrial growth and regression may be regulated by the balance of these factors under the action of ovary steroids.

Animals↗
PubMed2005

Involvement of molecules related to angiogenesis, proteolysis and apoptosis in implantation in rhesus monkey and mouse.

We have established the well-defined cycling, pseudo-pregnant and pregnant rhesus monkey models, and used these to analyze expression of the common molecules specifically related to angiogenesis, apoptosis or proteolysis, such as vascular endothelial growth factor (VEGF) and its receptors KDR, flt-1, flt-4 and flk-1, basic fibroblast growth factor (bFGF) and its receptors Flg, transforming growth factor-alpha and beta1 (TGF-a/beta1), and TGF-beta1 receptor type I (TbetaR-I) and type II (TbetaR-II), as well as steroidogenic acute regulatory protein (StAR), tissue type plasminogen activator/urokinase plasminogen activator/plasminogen activator inhibitor type 1 (tPA/uPA/PAI-1) and matrix matalloproteinase type 1, -3/tissue inhibitor matalloproteinase type 1, -2, -3 (MMP-1, -3/TIMP-1, -2, -3), Fas/FasL, BcL-2/Bax, in the corpus luteum (CL), in the functional layer of the endometrium and in the materno-fetal boundary of the implantation site. We have demonstrated that: expression of these molecules in the monkey CL, endometrium and materno-fetal boundary of the implantation site is correlated well with CL functional and vascular development and with the processes involved in the establishment of the implantation window as well as with the early stages of placentation. A coordinated increase in tPA and its inhibitor PAI-1 expression in the monkey and rat CL may be instrumental in initiating luteal regression in both species, and correlated well with the timing of the closure of the implantation window, whereas high uPA activity in the CL is important for the early formation of the CL and for maintaining its function which is closely correlated to the period of establishment of the implantation window. Apoptosis, proteolysis and angiogenesis occur in the CL and in the endometrium during the time of establishment of the implantation window, as well as in the materno-fetal boundary of the implantation site at the early stages of placentation. It seems that these processes occur in these tissues in a coordinated and time- and cell-dependent manner, and are reliant on each other. Based on these observations, we have designed experiments to test the actions of some related available compounds on mouse implantation, used alone or in combination. The preliminary data showed that the compounds which could effectively affect apoptosis, angiogenesis or proteolysis in the implantation site were capable of effectively inhibiting implantation by acting on the endometrium and/or on the CL. Furthermore, the combined use of these compounds produced an obvious additive effect on inhibiting implantation. This finding suggested this may be a good approach for developing an anti-implantation agent.

Animals↗
PubMed2005

[Effects of ethyl pyruvate on cell-mediated immune function in rats with delayed resuscitation after burn injury].

OBJECTIVE: To investigate the effects of ethyl pyruvate (EP) on cell-mediated immune function in rats with delayed resuscitation after burn injury, and its potential regulatory mechanism. METHODS: Wistar rats were subjected to 30% full-thickness scald injury with delayed resuscitation. One hundred and three male rats were randomly divided into normal controls (n=7), sham scald group (n=32), scald group (n=32) in which 40 ml/kg normal saline was infused peritoneally 6 hours after scald, and EP treatment group (n=32) in which 40 mg/kg EP was injected peritoneally 6 hours after scald. Animals were sacrificed on postburn day 1, 3, 5, and 7, and spleen was collected to determine splenocyte proliferation, IL-2 production and cell-surface IL-2 receptor (IL-2R) expression. RESULTS: Splenic lymphocyte proliferation responses to T cell mitogen, concanavalin A (Con A), were depressed from 1 to 7 days after scald injury (all P<0.05). Meanwhile, in comparison with sham scald group, burn injury resulted in a significant decrease in splenic production of IL-2 on postburn day 1, 3, as well as 5, and a marked suppression of IL-2R expression on days 1 and 3 postburn (all P<0.05). Treatment with EP after burn injury showed a dramatic restoration of lymphocyte proliferation rate and increased production of IL-2 at various time points (all P<0.05). However, treatment with EP did not affect IL-2R expression compared with scalded rats (all P>0.05). CONCLUSION: Treatment with EP could markedly elevate splenic T lymphocyte proliferation response and increase production of IL-2 following burn injury, thereby improving cell-mediated immunity in thermally injured rats with delayed resuscitation.

Animals↗
PubMed2005

[Effects of ethyl pyruvate on splenocyte proliferation and apoptosis in burn rats with delayed resuscitation].

OBJECTIVE: To investigate the effects of ethyl pyruvate (EP) on splenocyte proliferation and apoptosis in burn rats with delayed resuscitation, and its potential underlying mechanism. METHODS: Seventy two male Wistar rats were randomly divided into sham-scalded control group (n=24), scald group (n=24), and scald with EP treatment group (n=24). Animals were sacrificed on days 1, 3, and 5 postburn, and spleen samples were collected to determine splenocyte proliferation and apoptosis. RESULTS: Splenic lymphocyte proliferation response to T cell mitogen, concanavalin A (Con A), as significantly depressed from 1 to 5 days after burn injury (all P<0.05). Meanwhile, burn injury resulted in a marked increase in splenic CD3(+)CD4(+)T lymphocyte apoptosis in comparison with that in sham-scalded controls on day 1 postburn (P<0.05). Treatment with EP after burns resulted in a dramatic restoration of lymphocyte proliferation response and reduction of splenic CD3(+)CD4(+)T lymphocyte apoptosis compared with scald group (P<0.05). CONCLUSION: Administration of EP can markedly improve the splenocyte proliferation response and inhibit splenic CD3(+)CD4(+)T lymphocyte apoptosis in thermally injured rats.

Animals↗
PubMed2004

[Effect of RU486 on apoptosis and p53 expression at the boundary of fetal-maternal interface of rhesus monkey (Macaca mulatta)].

Primate placentation involves a series of cell proliferation, immigration and apoptosis which account for the progressive tissue remodelling at the implantation site. p53 is an important proto-oncogene involved in the regulation of cell-cycle and apoptosis. To study the effect of RU486 on apoptosis and expression of p53 at the fetal-maternal interface, the location of apoptotic cells and expression of p53 were examined using in situ 3'-end labeling method, immunohistochemistry and Western blot assay at the fetal-maternal interface of normal and RU486 treated rhesus monkey. Western blot analysis showed the specificity of the anti-human antibody used with the monkey tissue. In the placental villi, the apoptotic nuclei were observed mainly in the syncytiotrophoblast and part of the cytotrophoblast within the cell column; p53 protein was detected mainly in the cytotrophoblast. In the endometrium, positive signals for apoptosis and p53 were detected in some stromal cells. After two days of mifepristone treatment, the apoptotic cells increased significantly in both placental villi and endometrium. In the villi, the increased apoptotic nuclei were mainly localized to the cytotrophoblast. At the same time, p53-positive nuclei also increased in both villous cytotrophoblast cells and endometrial stromal cells, after the treatment of RU486. These results suggest that apoptosis and expression of p53 are essential in regulating trophoblastic homeostasis by controlling its proliferation in normal placenta, whereas the up-regulation of p53 protein may play an important role in apoptosis that happens at the fetal-maternal interface induced by RU486.

Abortifacient Agents, Steroidal↗
PubMed2004

VEGF, bFGF, and their receptors in the endometrium of rhesus monkey during menstrual cycle and early pregnancy.

A number of cytokines and growth factors are known to modulate proliferation and differentiation of human endometrium. In this study, the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and VEGF receptors, fms-like tyrosine kinase (Flt1) and kinase insert domain-containing region (KDR), and bFGF receptor 1 (Flg) were examined in the endometrium of rhesus monkey on Day 5, 10, 16, 20, 25 of menstrual cycle and on Day 19 of early pregnancy. Western blot analysis showed the specificity of the anti-human antibodies with the monkey tissue. The expression of mRNA and protein of VEGF was correlated with that of its receptor KDR, which was detected in epithelial, vascular, and myometrial cells. The localization of bFGF and its receptor Flg was similar to that of VEGF, except that the Flg was absent in the endothelial cells. Strong expression of VEGF and bFGF in the glandular epithelial cells was observed in the proliferative phase, declined in the secretory phase during the cycle. Stronger staining of these factors was also observed in the decidual cells of the pregnant uterus, as compared with the stromal cells of cycling uterus. No expression of Flt1 was detected in the tissue examined in this study. These data suggest that VEGF, bFGF, and their receptors play important roles in epithelial and stromal development, angiogenesis, and blood vessel function in the endometrium during the menstrual cycle and early pregnancy of the rhesus monkey.

Animals↗
PubMed2004

Contraceptive action of a gonadotropin-releasing hormone II analog in the rhesus monkey.

GnRH I (mammalian GnRH) was previously thought to be the only isoform of GnRH expressed in mammals, but GnRH II (chicken II GnRH) has now been identified in tissues of numerous mammalian species. Specific high-affinity receptors, which bind GnRH II and its analogs, have been identified throughout the reproductive tract, and GnRH II regulation of progesterone and human chorionic gonadotropin have been demonstrated. Thus, we hypothesized that GnRH II acts as a paracrine factor to regulate extrahypothalamic tissue functions and could be used as an effective contraceptive agent. In these studies, we examined the effect of a stable analog of GnRH II (GnRH II analog) on ovarian steroidogenesis, implantation, and maintenance of pregnancy in the rhesus monkey. GnRH II analog or saline was administered by osmotic minipumps on d 1-6, d 6-11, or d 11-17 to cycling monkeys mated with fertile males. Circulating progesterone and estradiol were determined during the luteal phase, and the cycle length before, during, and after treatment was observed. Circulating monkey chorionic gonadotropin was used to determine implantation. In animals treated with GnRH II analog on d 1-6, no pregnancies resulted; but in saline-treated controls, five of eight animals (62.5%) became pregnant. In animals treated with analog on d 6-11, two of five (40.0%); and on d 11-17, one of three (33.3%); implanted and normal pregnancies ensued. Cycle length or progesterone production was not affected by analog treatment. These data demonstrate that this GnRH II analog can act as a contraceptive agent when administered chronically around the time of ovulation or early luteal development. These findings suggest that GnRH II may play a role in reproductive physiology and that GnRH II analogs may serve as an effective, nonsteroidal, postcoital contraceptive.

Animals↗