Biomedical subjects

Yu Zhu

Publications and source records attributed to Yu Zhu.

At least 19 recordsLinked to original sources

PubMed2026

Microglial PICALM: A novel genetic driver and therapeutic target in vascular dementia.

BACKGROUND: Vascular dementia (VaD) lacks well-defined genetic mechanisms. Cell-type-specific effects of GWAS loci remain unexplored. METHODS: We integrated single‑cell eQTL data (183 donors, eight cell types) with VaD GWAS (3624 cases, 475,484 controls) using Mendelian randomization and Bayesian colocalization, replicated in an independent cohort (2074 cases, 456,366 controls). Subtype, snRNA‑seq, cell‑cell communication, PheWAS, expression profiling, and drug prediction with BBB permeability assessment were performed. RESULTS: Microglial PICALM was the only robustly replicated signal (OR = 0.8334, p = 5.3 × 10⁻⁴; colocalization PP.H4 > 0.75). The effect was strongest in multiple infarctions dementia (OR = 0.7746). Exploratory snRNA-seq analysis (4 VaD vs. 4 controls; GSE282111) provided supporting evidence for microglial PICALM enrichment and downregulation (p < 0.001). PICALM‑high microglia showed enhanced neurovascular‑ and phagocytosis‑related communication (e.g., SPP1, GAS6, GRN). PheWAS revealed no pleiotropy. In silico drug repurposing prioritised three FDA-approved BBB-penetrant compounds (disopyramide, benzocaine, amantadine) as candidates warranting further mechanistic validation. CONCLUSIONS: Microglial PICALM is identified as a likely genetic determinant of VaD, especially in the multiple infarctions subtype. Upregulating PICALM may be associated with a neuroprotective microglial phenotype, highlighting PICALM as a candidate therapeutic target warranting further experimental validation.

Humans↗

PubMed2025

Cr3a, a candidate gene conferring fruit cracking resistance, was fine-mapped in an introgression line of Solanum lycopersicum L.

In the cultivation and production of tomato (Solanum lycopersicum L.), fruit cracking is a prevalent and detrimental issue that significantly impacts the esthetic quality and commercial value of the fruit. The complexity of the trait has resulted in a slow advancement in research aimed at identifying genes that influence tomato fruit cracking and the underlying regulatory mechanisms. In this study, a sub-introgression population for tomato crack-resistant fruit has been constructed from the cross between S. lycopersicum 1052 and Solanum pennellii LA0716, followed by 11 generations of selfing. Utilizing specifically designed InDel markers, the tomato crack-resistant gene, Cr3a, was fine-mapped, cloned, and its functionality was confirmed through transgenic and gene-knockout approaches. The precise localization of Cr3a was delineated to a 30 kb genomic region on chromosome 3, corresponding to the gene Sopen03g034650 in S. pennellii and Solyc03g115660.3 in the Heinz1706 variety. An integrated transcriptomic and metabolomic analysis of fruits with and without the Cr3a gene was finally conducted to elucidate the intricate regulatory mechanisms associated with Cr3a. The findings revealed a molecular regulatory network for tomato fruit crack resistance, characterized by 7 key metabolites, 13 pivotal genes, and 4 critical pathways: the phenylpropanoid biosynthesis pathway, the phenylalanine, tyrosine, and tryptophan biosynthesis pathway, the linolenic acid metabolism pathway, and the cysteine and methionine metabolism pathway. In summary, this research provides novel insights into the molecular underpinnings of tomato fruit crack resistance and holds substantial promise for accelerating the molecular breeding of tomatoes with enhanced fruit crack resistance.

Solanum lycopersicum↗

PubMed2006

Large common fragile site genes and cancer.

The common fragile sites are large regions of genomic instability that are found in all individuals and are hot spots for chromosomal rearrangements and deletions. A number of the common fragile sites have been found to span genes that are encoded by very large genomic regions. Two of these genes, FHIT and WWOX, have already been demonstrated to function as tumor suppressors. In this review we will discuss the large common fragile site genes that have been identified to date, and the role that these genes appear to play both in cellular responses to stress and in the development of cancer.

Acid Anhydride Hydrolases↗

PubMed2006

Tricyclohexylphosphine-cyclopalladated ferrocenylimine complexes: synthesis, crystal structures and application in Suzuki and Heck reactions.

A series of novel tricyclohexylphosphine (PCy(3))-cyclopalladated ferrocenylimine complexes 2c-2g have been easily synthesized. These new palladacycles are thermally stable and are not sensitive to air and moisture. Their detailed structures have been determined by single-crystal X-ray analysis and six different types of intermolecular hydrogen bonds are found to be existed in the crystals of these complexes. The use of 2c-2g as catalysts for Suzuki and Heck reactions was examined. They were found to be very efficient for the Suzuki reaction of aryl chlorides with phenylboronic acid. Typically, using 0.1 mol% of catalyst in the presence of 1.5 equivalent of Cs(2)CO(3) as base in dioxane at 100 degrees C provided coupled products in excellent yields. These complexes also displayed good activity in the Heck reaction of a range of aryl bromides with acrylic acid ethyl ester although they were not particularly useful for the activation of aryl chlorides.

Catalysis↗

PubMed2006

Studies on cage-type tetranuclear metal clusters with ferrocenylphosphonate ligands.

Reaction of FcCH(2)PO(3)H(2) [Fc=(eta(5)-C(5)H(5))Fe(eta(5)-C(5)H(4))] (H(2)FMPA) and 1,10-phenanthroline (phen) with Cd(OAc)(2).2 H(2)O or ZnSO(4).7 H(2)O in methanol in the presence of triethylamine resulted in the formation of two new ferrocenylphosphonate metal-cage complexes [M(4)(fmpa)(4)(phen)(4)] 7 CH(3)OH (M=Cd 1, M=Zn 2). Both structures contain two kinds of isomeric tetranuclear metal phosphonate cages, which are linked to one another by pi-pi interactions between the phen molecules. In 1, the Cd1, Cd3, and Cd4 atoms are all pentacoordinate, while the Cd2 atom is coordinated by four oxygen atoms from three phosphonate ligands and two nitrogen atoms from the chelating phen in a distorted octahedral geometry. Four Cd atoms from each unit are interconnected through bridging phosphonate ligands with different coordination modes, such as 5.221, 4.211, and 2.11 (Harris notation), yielding a {Cd(4)} cage. In 2, each Zn atom is coordinated by three oxygen atoms from three phosphonate ligands and two nitrogen atoms from phen, leading to a distorted square-pyramidal geometry. The four Zn atoms of each isomeric unit are also interconnected through four bridging phosphonate ligands to yield a {Zn(4)} cage. Fluorescent studies indicate that ligand-to-ligand charge-transfer photoluminescence is observed for 1, while the emission bands of 2 can be assigned to an admixture of ligand-to-ligand and metal-to-ligand charge transfer. Solution-state differential pulse voltammetry indicates that the half-wave potentials of the ferrocenyl moieties in 1 and 2 have different deviations relative to the relevant H(2)FMPA ligand. This may be because the highest occupied molecular orbital (HOMO) in 1 is located in the FMPA(2-) groups, while in 2 the HOMO is located in the phen and Zn(II) groups, so the Fe(II) centers in complex 1 are more easily oxidized to Fe(III) centers than those of 2. The third-order nonlinear optical (NLO) measurements show that both 1 and 2 exhibit strong third-order NLO self-focusing effects; hence, they are promising candidates for NLO materials. By calculating the component of the lowest unoccupied molecular orbitals of 1 and 2, we confirmed that the co-planar phen rings control their optical nonlinearity, while the H(2)FMPA ligands and metal ions have only a weak influence on their NLO properties.

Journal Article↗

PubMed2006

Primary pigmented nodular adrenocortical disease: report of 5 cases.

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Adolescent↗

PubMed2006

[Down regulation of mitogen activated protein kinase phosphatase-1 mediate acquired multidrug resistance in pancreatic adenocarcinoma cell line SW1990/Fu].

OBJECTIVE: To investigate the role of mitogen activated protein kinase phosphatase-1 (MKP-1) in mediating acquired multidrug resistance in pancreatic adenocarcinoma cell line SW1990/Fu. METHODS: To detect MKP-1 mRNA expression, Northern blot analysis was carried out in well established drug resistant pancreatic adenocarcinoma cell line SW1990/Fu, SW1990 and MiaPaCa-2 cell lines. To further elucidate the exact role of MKP-1, Western blot hybridization was performed in these three cell lines. RESULTS: Northern blot analysis of total RNA isolated from SW1990/Fu, SW1990 and MiaPaCa-2 cell lines revealed the presence of the 2400 bp MKP-1 transcript 7 at relatively high levels in pancreatic cancer cell lines SW1990 and MiaPaCa-2. In the SW1990/Fu, the MKP-1 transcript was detectable at very low level. Densitometric analysis with normalization to 7S indicated that MKP-1 mRNA expression level was significantly decreased in SW1990/Fu in comparison with the parental and MiaPaCa-2 cell lines. MKP-1 protein expression level in SW1990/Fu detected by Western blot was coincident with mRNA level. CONCLUSIONS: MKP-1 may be involved in acquired multidrug resistance in pancreatic adenocarcinoma, and we could hypothesized that alterations of intra-cellular transduction signal system acts as an important role in multidrug resistance of tumor cells.

Adenocarcinoma↗

PubMed2006

CD8+ lymphocyte-mediated injury of dorsal root ganglion neurons during lentivirus infection: CD154-dependent cell contact neurotoxicity.

Neuronal damage in dorsal root ganglia (DRGs) with accompanying axonal injury is a key feature of human immunodeficiency virus (HIV)-related distal sensory polyneuropathy (DSP). In a model of HIV-related DSP, we observed numerous CD3+ T lymphocytes (p < 0.05) in DRGs from feline immunodeficiency virus (FIV)-infected animals, which also exhibited low CD4+ and high CD8+ lymphocyte levels in blood accompanied by a selective loss of small-diameter sural nerve axons (p < 0.05). FIV-infected lymphocytes cocultured with syngeneic DRGs caused neuronal damage, indicated by neurite retraction, neuronal soma atrophy, and loss (p < 0.05). In contrast, supernatants from FIV-infected or uninfected lymphocytes were minimally neurotoxic, despite high FIV virion levels. Among lymphocyte subsets cocultured with DRG cultures, CD8+ T cells from both FIV-infected and uninfected lymphocytes selectively caused DRG neuronal injury (p < 0.05). FIV-infected CD8+ T cells showed markedly increased CD154 expression (p < 0.05), whereas neurons were the predominant cells expressing CD40 in DRGs. Blocking CD154 on activated CD8+ T cells protected DRG neurons (p < 0.05). These findings indicated that CD8+ T cells were principal effectors of DRG neuronal injury after FIV infection through a CD40-CD154 interaction in a cell contact-dependent manner.

Animals↗

PubMed2006

[Prevention of incontinence after radical prostatectomy].

OBJECTIVE: To discuss the effect of urine control after radical retropubic prostatectomy by preserve the membranous part of sphincter urethrae and the neurovascular bundle, or to rebuild the bladder neck. METHODS: The radical retropubic prostatectomy was performed on a total of 32 cases of prostate cancer. We preserve the membranous part of sphincter urethrae and the neurovascular bundle lateral to the prostate. We evaginate the posterior wall of the bladder adequately and make an additional folding stitch to rebuild the bladder neck. RESULTS: The follow up is of 6-72 months. All patients could void without difficulty, no tumor recurrence and only 2 cases occurred slight incontinence. Other 30 cases regained the ability of controlling their urinations within 6 months. CONCLUSIONS: The incontinence after radical retropubic prostatectomy could be reduced by the method of preserving the membranous part of sphincter urethrae and preserving the neurovascular bundle lateral to the prostate in operation. It could also be avoided by evaginate the posterior wall of the bladder adequately and make an additional folding stitch to the bladder neck.

Aged↗

PubMed2006

A series of metal-organic polymers assembled from MCl2 (M = Zn, Cd, Co, Cu): structures, third-order nonlinear optical and fluorescent properties.

In this paper four metal-organic polymers {[Zn(fcz)Cl2].CH3OH}n 1, {[Cd(fcz)2Cl2].CH3OH.2H2O}n 2, {[Co(fcz)2Cl2].2CH3OH}n 3 and {[Cu(fcz)2Cl2].2CH3OH}n 4 (fcz = fluconazole: alpha-(2,4-difluorophenyl)-alpha-(1H-1,2,4-triazol-l-ylmethyl)-1H-1,2,4-triazole-l-ethanol) were synthesized and characterized by X-ray single crystal diffraction. Polymer consists of 1-D infinite chains arranged along the b-axis. All of polymers 2-4 exhibit a 2-D rhombohedral grid structure. We study the third-order nonlinear optical properties of fcz and polymers 1-4 in DMF solution by using 8 ns laser pulses at 532 nm, and find that 1 and 4 exhibit different NLO properties from fcz and both 2 and 3 show similar NLO properties to fcz. 1 possesses strong NLO refractive effects and large NLO absorptive behaviors. 2, 3 and fcz exhibit strong refractive effects, but their NLO absorptive behaviors are weaker than that of 1. The NLO effects of 4 are very weak. The study of optical limiting (OL) effects by using 40 ps laser pulses at 532 nm shows that fcz and polymer 3 possess a strong OL effect. The optical limiting threshold values of 0.15 J cm(-2) for fcz and 0.16 J cm(-2) for are comparable to those of many heterothiometallate clusters. Polymers 1, 2 and 4 show a weak OL effect. The fluorescent spectra in DMF solution (concentration: 1 x 10(-4) mol dm(-3)) show that polymers 1-4 exhibit different luminescence properties from fcz. The maximum wavelength of polymers 1-3 are blue shifted gradually by 2-12 nm while polymer 4 exhibits a fluorescent self-quenching phenomenon. These results demonstrate that metal ions play an important part in the NLO and fluorescent properties of coordination polymers.

Journal Article↗

PubMed2006

[Relationship between apoptosis induced by 2-butylamino-2-demethoxy-hypocrellin B in human pancreatic cancer cells Capan-1 and photosensitization of mitochondria].

OBJECTIVE: To explore the possible mechanism of apoptosis induced by photodynamic therapy (PDT) in human pancreatic cancer cells Capan-1 with 2-butylamino-2-demethoxy-hypocrellin B (BAHB) as photosensitizer. METHODS: The localization of BAHB in Capan-1 cells was studied, apoptosis was determined by DNA gel electrophoresis after PDT. The mitochondria membrane potential (DYm) and cytochrome C release were observed by laser scan confocal microscopy and Western blotting. RESULTS: The low concentration photosensitizer was mainly localized in mitochondria and also in lysosomes when the concentration is high. DNA ladder analysis showed characteristic of apoptosis. The mitochondria membrane potential (DYm) showed a loss of 30% around, after 6 hours by PDT under laser scan confocal microscopy, which is caused by a sudden increase in the permeability of mitochondria membrane accompanied with apoptosis. In Western blotting, cytochrome C release was observed from the mitochondria into the cytoplasm during BAHB-induced apoptosis. CONCLUSION: The research suggests that BAHB-induced apoptosis is related to photosensitization of mitochondria.

Apoptosis↗

PubMed2006

Identification of Rhodospirillum rubrum GlnB variants that are altered in their ability to interact with different targets in response to nitrogen status signals.

In Rhodospirillum rubrum, NifA, the transcriptional activator for the nif genes, is posttranslationally activated only by the uridylylated form of GlnB, one of three P(II) homologs in the organism. We have used the yeast two-hybrid system to detect variants of GlnB that interact better with NifA than does wild-type GlnB. When examined for physiological effects in R. rubrum, these GlnB* variants activated NifA in the presence of NH(4)(+), which normally blocks NifA activation completely, and in the absence of GlnD, whose uridylylation of GlnB is also normally essential for NifA activation. When these variants were tested in the two-hybrid system for their interaction with NtrB, a receptor that should interact with the nonuridylylated form of GlnB, they were uniformly weaker than wild-type GlnB in that interaction. When expressed in R. rubrum either as single-copy integrants or on multiple-copy plasmids, these variants were also dramatically altered in terms of their ability to regulate several other receptors involved in nitrogen metabolism, including GlnE, NtrB/NtrC, and DRAT (dinitrogenase reductase ADP-ribosyl transferase)-DRAG (dinitrogenase reductase-activating glycohydrolase). The consistent pattern throughout is that these GlnB variants partially mimic the uridylylated form of wild-type GlnB, even under nitrogen-excess conditions and in strains lacking GlnD. The results suggest that the role of uridylylation of GlnB is primarily to shift the equilibrium of GlnB from a "nitrogen-sufficient" form to a "nitrogen-deficient" form, each of which interacts with different but overlapping receptor proteins in the cell. These GlnB variants apparently shift that equilibrium through direct structural changes.

Bacterial Proteins↗

PubMed2006

[Mutation screening of RET proto-oncogene in Chinese sporadic patients with pheochromocytoma].

OBJECTIVE: To screen the mutations of RET proto-oncogene in sporadic patients with pheochromocytoma. METHODS: Forty-two cases of sporadic pheochromocytoma were tested for mutations of RET gene. Of these 42 DNA samples, 12 were extracted from peripheral blood cells and 30 from paraffin-embedded pheochromocytoma specimens. The PCR product of exon 10 and exon 11 was used to molecular analysis of the RET proto-oncogene. RESULTS: Among 42 patients, 2 were found to have RET gene mutations. One of mutations located at codon 634 (TGC>TAC) in exon 11 of RET proto-oncogene. Another one located at codon 632 (GAG>AAG). CONCLUSION: Some patients with apparently sporadic pheochromacytoma were carrier of mutations, a routine genetic analysis for mutations of RET gene is indicated for these patients.

Adrenal Gland Neoplasms↗

PubMed2006

[Karyotype analysis in 119 patients with chronic myeloid leukemia at blast crisis].

To investigate the karyotype of chronic myeloid leukemia in blast crisis (CML-BC), karyotype analysis was performed with R-banding technique in 119 patients with CML-BC. Dual fusion fluorescence in situ hybridization (FISH) was used to detect derivative chromosome 9 deletions in randomly selected 28 cases of them. The results showed that 11 cases (8.9%) were Ph negative; 113 cases (91.1%) were Ph positive; 104 cases (83.9%) had standard Ph translocation; 9 cases (7.2%) showed variant translocation, including 4 cases (3.2%) with simple variant translocation and 5 cases (4.0%) with complex variant translocation. 72.6% of Ph negative CML-BC had extra chromosomal abnormalities, with the most common ones being i (17q) and +14. 72.3% of Ph positive CML-BC had extra cytogenetic changes and +Ph, +8, i (17q) were the most frequent. The average time between diagnosis and blast crisis was 29.0 months (range 2 to 66 months) for Ph negative cases and 34.2 months (range 1 to 127 months) for Ph positive cases. 5 cases (5/28, 17.9%) with der (9) deletions were detected by FISH technique. It is concluded that extra chromosomal abnormalities are common in CML-BC patients and FISH can effectively detect the der (9) deletions.

Adult↗

PubMed2005

Profiling an electrospray plume using surface-enhanced Raman spectroscopy.

We report the use of silver nanoparticles to obtain surface-enhanced Raman spectra of Crystal Violet in an electrospray plume. Surface enhancement allowed detection at low concentrations with the high specificity afforded by vibrational spectroscopy. SERS spectra were used to obtain an axial concentration profile closely matching that obtained in previous fluorescence experiments. SERS can provide more analyte structural information than has been obtainable from fluorescence studies of the plume.

Electrochemistry↗

PubMed2005

Common fragile sites, extremely large genes, neural development and cancer.

Common fragile sites (CFSs) are large regions of profound genomic instability found in all individuals. They are biologically significant due to their role in a number of genomic alterations that are frequently found in many different types of cancer. The first CFS to be cloned and characterized was FRA3B, the most active CFS in the human genome. Instability within this region extends for over 4.0 Mbs and contained within the center of this CFS is the FHIT gene spanning 1.5 Mbs of genomic sequence. There are frequent deletions and other alterations within this gene in multiple tumor types and the protein encoded by this gene has been demonstrated to function as a tumor suppressor in vitro and in vivo. In spite of this, FHIT is not a traditional mutational target in cancer and many tumors have large intronic deletions without any exonic alterations. There are several other very large genes found within CFS regions including Parkin (1.37 Mbs in FRA6E), GRID2 (1.47 Mbs within 4q22.3), and WWOX (1.11 Mbs within FRA16D). These genes also appear to function as tumor suppressors but are not traditional mutational targets in cancer. Each of these genes is highly conserved and the regions spanning them are CFSs in mice. We have now examined lists of the largest human genes and found forty that span over one megabase. Many of these are derived from chromosomal bands containing CFSs. BACs within these genes are being utilized as FISH probes to determine if these are also CFS genes. Thus far we have identified the following as CFS genes: CNTNAP2 (2.3 Mbs in FRA7I), DMD (2.09 Mbs in FRAXC), LRP1B (1.9 Mbs in FRA2F), CTNNA3 (1.78 Mbs in FRA10D), DAB1 (1.55 Mbs in FRA1B), and IL1RAPL1 (1.36 Mbs in FRAXC). Although, these genes are also not traditional mutational targets in cancer they do exhibit loss of expression in multiple tumor types suggesting that they may also function as tumor suppressors. Many of the large CFS genes are involved in neurological development. Parkin is mutated in autosomal recessive juvenile Parkinsonism and deletions in mice are associated with the mouse mutant Quaking (viable). Spontaneous mouse mutants in GRID2 and DAB1 are associated with Lurcher and Reelin, respectively. In humans, alterations in IL1RAPL1 cause X-linked mental retardation and loss of WWOX is associated with Tau phosphorylation. We propose that the instability-induced alterations in these genes contribute to cancer development in a two-step process. Initial alterations will primarily occur within intronic regions, as these genes are greater than 99% intronic. These are not benign. Instead, they alter the repertoire of transcripts produced from these genes. As cancer progresses deletions will begin to encompass exons resulting in gene inactivation. These two types of alterations occurring in multiple large CFS genes may contribute significantly to the heterogeneity observed in cancer. There are also important potential linkages between normal neurological development and the development of cancer mediated by alterations in these genes.

Acid Anhydride Hydrolases↗

PubMed2005

Conductance of an ensemble of molecular wires: a statistical analysis.

We report on a first principles analysis of quantum transport through molecular wires made of 4,4'bipyridine and 6-alkanedithiol contacted by Au electrodes. We investigate how charge transport is altered due to small structure changes at the molecule-electrode contacts. These changes include distance between the molecule and the contact, extra metal atoms at the Au surface, binding sites, molecular orientation, and bias voltages. By investigating hundreds of wires we extract a statistical picture on transport properties of the two different molecules. We compare quantitatively with the corresponding experimental data.

Journal Article↗

PubMed2005

[Clinicopathologic features and surgical treatment of nonfunctioning islet cell tumors (78 case report)].

OBJECTIVE: To investigate surgical treatment results and clinical pathological specifics in the treatment of non-functional islet cell tumor. METHODS: To perform retrospective analysis of 78 cases of non-functional islet cell tumor treated at Peking Union Medical College Hospital from July 1968 through January 2005, and summarize clinical symptoms and signs, primary diagnosis before surgery, surgical treatment, pathologic specifics and immuno-histological analysis. RESULTS: Of 78 cases, 27 cases (34.6%) was found in physical examinations, the most common symptoms was upper abdominal pain and upper abdominal discomfort, 30.7% (24 cases) and 26.9% (21 cases) respectively; the most common sign being abdominal masses 35.9% (28 cases). B-us and CT are most commonly used forms of preoperative examination, with positive rates being 98.6% (71/72), 100% (53/53) respectively. Operative mortality was 1.28%, Radical surgery of malignant cases with 5 year survival rate 75% (9/12). Immuno-histological examinations showed that tumors with multi peptide linked hormones 78.6% (55/70), a larger number of positive examinations of neuron specific enolase and chromaffin, 91.4% (32/35) and 79.4% (27/34) respectively. Insulin, glucagon, pancreatic polypeptide, somatostatin, vasoactive intestinal peptide and gastrin positive rates are 64.6% (42/65), 47.5% (22/53), 45.8% (22/48), 37.5% (21/56), 23.9% (11/46) and 22.6% (7/31). CONCLUSIONS: Non-functional islet cell tumor lack specificity, Bus and CT are primary examination methods, immuno-histological analysis indicates various different hormones, but lacks the presence of related clinical symptoms. Surgery is an effective form of treatment in the treatment of non-functional islet cell tumor, even with distal metastasis, immediate surgical removal and treatment, extend prognosis.

Adenoma, Islet Cell↗