Biomedical subjects

H Liang

Publications and source records attributed to H Liang.

At least 19 recordsLinked to original sources

PubMed2026

Fourier-transform infrared-based genome-wide association study identifies candidate genes and variants for sow colostrum composition.

Sows with high prolificacy and better lactation traits are beneficial for weaned piglet number. Because the genetic basis of sow lactation traits remains elusive, genetic improvement for lactation traits lags behind that for litter traits, constraining the full realisation of genetic potential for large litters. Here, we measured 1 060 Fourier-transform infrared (FTIR) wavenumbers and five predicted colostrum composition traits from sow colostrum samples. Heritability estimates for both the FTIR spectra and predicted traits ranged from moderate to high. Correlation analysis revealed that lactose percentage was negatively genetically correlated with the other four predicted traits (fat percentage, protein percentage, total solid content, and urea nitrogen content) and with 24 h litter weight, which was positively genetically correlated with both protein and total solid content. Genome-wide association studies on the FTIR spectra and predicted traits identified 134 significant single-nucleotide polymorphisms (SNPs) (False discovery rate < 0.05), with most clustering on Sus scrofa chromosomes (SSC) 5 and 7. Among the candidate genes, two expressed in lactating mammary tissue have established roles in milk trait determination: (1) LALBA, which encodes a major colostrum protein and is responsible for lactose synthesis, and (2) BTN1A1, which mediates milk fat secretion. Additionally, the study detected two important candidate variants on SSC7: (1) rs691487382, which was colocalised with the expression quantitative trait locus signal for TRIM26 in the liver, a key metabolic organ supporting lactation, and (2) rs327923027, a missense variant located in a phylogenetically conserved domain of TRIM26, an E3 ubiquitin ligase implicated in liver homeostasis. Taken together, this study identifies, for the first time, candidate genes and variants for sow colostrum, providing genomic markers useful for genetic improvement.

Association analysis↗

PubMed2007

CT of jejunal diverticulitis: imaging findings, differential diagnosis, and clinical management.

AIM: To describe the imaging findings of jejunal diverticulitis as depicted at contrast-enhanced computed tomography (CT) and review the differential diagnosis and clinical management. MATERIALS AND METHODS: CT and pathology databases were searched for the diagnosis of jejunal diverticulitis. Three cases were identified and the imaging and clinical findings correlated. RESULTS: Jejunal diverticulitis presents as a focal inflammatory mass involving the proximal small bowel. A trial of medical management with antibiotics may be attempted. Surgical resection may be required if medical management is unsuccessful. CONCLUSION: The imaging findings at MDCT may allow a specific diagnosis of jejunal diverticulitis to be considered and may affect the clinical management of the patient.

Abdomen, Acute↗

PubMed2006

Combined amino acid mutations occurring in the envelope closely correlate with pathogenicity of EIAV.

The Chinese equine infectious anemia virus (EIAV) donkey-leukocyte attenuated vaccine (DLV) provides a unique natural model system to study the attenuation mechanism and immunological control of lentivirus replication. Critical consensus mutations were identified between virulent Chinese EIAV strains and vaccine strains. Based on a full-length infectious clone of EIAV vaccine strain pLGFD3, two molecular clones, mFD5-4-7 and mFD7-2-11, were successfully constructed, in which 4 and 6 critical consensus mutations in the env gene of the vaccine strain were point-mutated to the wild-type sequence, respectively by an overlap PCR mutagenesis strategy. The infectivity, virulence, and pathogenesis of the constructed clones were investigated in vitro using a reverse transcriptase assay, an indirect immunofluorescence assay, observation of cytopathogenic effect, and virion observation as well as in vivo by inoculation of animals with the resulting infectious clones. The pathogenic symptoms in horses inoculated with mFD7-2-11 were more severe than those inoculated with mFD5-4-7, whereas no pathogenic symptoms were detected in animals inoculated with their parental clone pLGFD3 strain. The results indicate that the consensus mutation residues of the env region involved in this study play significant roles in the virulence and pathogenicity of EIAV. This will contribute to the elucidation of the attenuating and protective mechanisms of the Chinese EIAV vaccine.

Amino Acid Sequence↗

PubMed2006

[Activation of TH1/TH2 pathways detected through the expression of CCR4 and CCR5 on the ocular surface of glaucomatous patients treated over the long term].

PURPOSE: The aim of this work was to study, using flow cytometry, the expression of two chemokine receptors, CCR4 and CCR5, known to be related to the TH2 and TH1 systems, respectively, and the expression of HLA-DR, a hallmark of inflammation, on conjunctival impression cytology specimens (ICS) of glaucomatous patients treated over the long term. PATIENTS AND METHODS: In this case-control study, ICS were taken in a series of 35 glaucomatous patients treated with topical antiglaucoma drugs for more than 1 year (seven with beta-blockers, ten with prostaglandins, and 18 receiving multiple treatments), and 20 normal subjects. Conjunctival cells were collected and incubated with specific monoclonal antibodies directed against CCR4, CCR5, and HLA-DR, in order to measure, in a masked manner using flow cytometry, the percentage of cells positive to each marker in the conjunctival epithelium. RESULTS: Compared to normal subjects, HLA DR expression was significantly elevated in glaucomatous patients, with a tendency toward higher levels in the multitreatment group and lower levels in patients treated with prostaglandins, which did not differ significantly from control values. Both CCR4 and CCR5 significantly increased in glaucoma patients on multitreatment or monotherapy compared with normal subjects. CONCLUSION: This study demonstrates the overexpression of these two chemokine receptors in the conjunctival epithelium of patients treated for more than 1 year. Our results showing the simultaneous overexpression of CCR4 and CCR5 thus suggest that the chronic use of topical treatments may concurrently stimulate the TH1 and TH2 systems. These results evoke inflammatory mechanisms, combining allergy and toxicity, and confirm the complexity of inflammatory reactions occurring in the ocular surface of glaucoma patients.

Case-Control Studies↗

PubMed2006

[Vaccine for glaucoma, myth or reality?].

The cellular mechanisms involved in the loss of ganglion cells observed in glaucomatous neuropathy are based on a phenomenon of apoptosis: a primary apoptosis, related to the initial hypertonic process whatever its mechanism, and a secondary apoptosis via the free oxygen radicals or nitrogen monoxide, responsible for neuronal degeneration even after the initial factor has disappeared. In addition, glaucoma appears to be characterized by an increase in both TNF-alpha of the glia in the optic-nerve head and its type 1 receptor in the ganglion cells of the retina, which makes them particularly easy to stimulate by TNF-alpha. T lymphocytes also provide a certain neuroprotection by freeing neurotrophins or growth factors when neuronal lesion occurs, according to a specific and active process involving antigen-presenting cells. The T lymphocyte response was stimulated by sensitizing them by epitopes sequestered in the nervous system, notably myelinic proteins, in animal models of ganglion degeneration (obtained via a secondary apoptosis similar to that found during glaucoma). Prevention of ganglion cells loss was also observed by prior immunization of animals using a synthetic polymer close to myelin (COP1), capable of stimulating a specific lymphocyte reaction of neuronal impairment without inducing uveitis. Finally, glial cells, both activated during glaucoma and by TNF-alpha, and secreting TNF-alpha, could serve as antigen-presenting cells and thus constitute the keys to neuroprotection, using an original pathway independent of intraocular pressure control.

Animals↗

PubMed2006

[Development of a rapid subtype-screening assay for the env region of HIV-1 CRF strains in Guangxi.].

BACKGROUND: To develop a simple and rapid subtype-screening assay for the env region of the circulating recombinant form (CRF) of human immunodeficiency virus type 1 (HIV-1) in Guangxi. METHODS: Proviral DNA from HIV-1 positive samples were extracted and subjected to the first round PCR with universal primers for the env region that can detect HIV-1 M group isolates. In the second round PCR, two pairs of subtype-specific primers that were designed to detect subtype C or B'/C and CRF01-AE respectively were added into one tube. The PCR products of different subtypes could be distinguished in agarose-gel electrophoresis. Additionally, all of these samples were sequenced and analyzed phylogenetically. RESULTS: Phylogenetic analysis of the env region of 50 samples showed that 3 samples (6%) were infected with CRF08-BC, 43 (86%) with CRF01-AE, and 4 (8%) remained unclassifiable. Detection of the subtype-specific primer sets revealed that 3 were subtype C or B'/C (100%), 39 were CRF01-AE (90.7%), with an adequate sensitivity (91.3%) and a high specificity (100%). Non-specific bands occasionally appeared but did not interfere with interpretation of the results. The phylogenetic analysis was consistent with subtype-specific primer sets and the consistency rate was 92%. The average reproducibility was 100% for CRF08-BC samples and 93.8% for CRF01-AE samples. CONCLUSION: A simple, rapid and low cost assay was developed for subtype-screening of CRF01-AE in Guangxi.

China↗

PubMed2005

Extraction of gastric slow waves from electrogastrograms: combining independent component analysis and adaptive signal enhancement.

The electrogastrogram (EGG), a cutaneous measurement of gastric electrical activity, is a mixture of gastric slow waves and noise. To detect the propagation of gastric slow waves, it is desired to obtain gastric slow waves in each of multichannel EGGs. Recently, independent component analysis (ICA) has shown its efficiency in separating the gastric slow wave from noisy multichannel EGGs. However, this method is not able to recover gastric slow waves in each of the multichannel EGGs. In this paper, a two-stage combined method was proposed for extracting gastric slow waves. First, ICA was performed to separate the gastric slow wave component from noisy multichannel EGGs. Second, adaptive signal enhancement with a reference input derived by the ICA in the first stage was employed to extract gastric slow waves in each channel. Quantitative analysis showed that, with the proposed method, the maximum root-mean-square error between the estimated time lag and its theoretical value in the simulations was only 0.65. The results from real EGG data demonstrated that the combined method was able to extract gastric slow waves from individual channels of EGGs which are important to identify the slow wave propagation. Therefore, the proposed method can be used to detect propagation of gastric slow waves from multichannel EGGs.

Biological Clocks↗

PubMed2005

Aclarubicin and low-dose Cytosine arabinoside in combination with granulocyte colony-stimulating factor in treating acute myeloid leukemia patients with relapsed or refractory disease and myelodysplastic syndrome: a multicenter study of 112 Chinese patients.

One hundred twelve patients with geriatric acute myeloid leukemia (AML), refractory or relapsed AML, or myelodysplastic syndrome and refractory anemia with excess of blasts in transformation (MDS-RAEBt) were entered into this study to receive CAG (aclarubicin and low-dose cytosine arabinoside [Ara-C]in combination with granulocyte colony-stimulating factor [G-CSF]) with the objective of evaluating the efficacy and tolerance of this regimen. Low-dose Ara-C was given subcutaneously at a dosage of 10 mg/m2 every 12 hours on days 1 to 14. Aclarubicin was administered intravenously at a dosage of 14 mg/m2 per day on days 1 to 4 (CAG regimen A) or 7 mg/m2 on days 1 to 8 (CAG regimen B). Recombinant G-CSF was given subcutaneously at a dosage of 200 3g/m2 per day on days 1 to 14. We demonstrated comparable overall complete remission rates for the 4 groups of patients: 30.8% (8/26) in the elderly patients, 48.4% (30/62) in the refractory AML patients, 44.4% (8/18) in the relapsed AML patients, and 38.5% (5/13) in the MDS-RAEBt patients. Of the 52 patients followed up, the 12-month progression-free survival (PFS) and overall survival (OS) rates estimated by the Kaplan-Meier method were 40.73% 3 8.15% and 42.85% 3 8.23%, respectively. The median PFS and OS times were 9.0 3 2.2 months and 11.0 3 1.6 months, respectively. Toxic effects were very rare and mainly consisted of neutropenia and thrombocytopenia due to myelosuppression; approximately 70% to 80% of patients had neutropenia or thrombocytopenia that exceeded National Cancer Institute grade II. Nonhematologic toxicities were not observed in this study. The CAG regimen seems promising, with acceptable toxicity, for the treatment of various categories of poor-prognosis AML and MDS-RAEBt.

Aclarubicin↗

PubMed2005

Risk assessment model for venothromboembolism in post-hospitalized patients.

AIM: Venothromboembolism (VTE) is an important condition in hospitalized patients accounting for significant morbidity and mortality, and the risk of VTE often continues post-hospitalization. Although risk assessment models have been developed to predict the risk of deep venous thrombosis (DVT) in hospitalized patients, no models have been developed that determine the risk of DVT during the post-hospitalization period. The objective of this study was to create a risk profile using risk factor assessment that could be used to predict which patients are at highest risk of developing DVT within 60 days following hospital discharge. METHODS: The computerized medical records of 380 patients (190 with DVT and 190 without DVT) who received care from 1995-2002 and were subsequently re-hospitalized within 60 days of discharge were retrospectively reviewed. Univariate and multivariate logistic regression analyses were conducted to identify risk variables related to VTE. A novel risk assessment model was created using risk factors from the logistic regression analyses. RESULTS: The prevalence of VTE was found to be 93.2% (69/74) in the high-risk category, 52.9% (109/206) in the moderate-risk category, and 12% (12/100) in the low-risk category. CONCLUSIONS: Once validated, this risk assessment model may be applied to identify patients who may be at increased risk of developing VTE post-hospitalization. Those at high risk should be considered for anticoagulation therapy during the post-hospitalization period. Availability of a risk profile using risk factor assessment to guide decisions related to anticoagulation therapy will have important ramifications relative to patient outcomes including morbidity, mortality, and reductions in VTE-associated cost.

Hospitalization↗

PubMed2004

Focal trough and patient positioning.

Panoramic radiography is a common imaging modality used in dentistry. Panoramic radiographs provide an overall view of the dentomaxillofacial complex and are often used along with intraoral radiographs during the diagnostic phase of patient treatment. In recent years, identification of potential stroke victims has been included as a benefit of panoramic radiographs. This has stimulated an increased interest in panoramic radiography both by oral and maxillofacial radiologists and by general dentists.

Aged↗

PubMed2004

Lingual vascular canals of the interforaminal region of the mandible: evaluation with conventional tomography.

The presence of lingual vascular foramina and canals in the interforaminal region may increase the risk of surgical complications during implant placement, bone grafting procedures and osteodistraction. Oral and maxillofacial radiologists should recognize this anatomical variant and include a description in their interpretative report to inform the referring clinician of the potential for surgical complications.

Angiography↗

PubMed2003

Recombinant prostate specific antigen inhibits angiogenesis in vitro and in vivo.

BACKGROUND: Prostate specific antigen (PSA) is a kallikrein family member with serine protease activity commonly used as a diagnostic marker for prostate cancer. We recently described anti-angiogenic properties of PSA [Fortier et al.: JNCI 91:1635-1640]. METHODS: Two forms of PSA were cloned and expressed in Pichia pastoris: one, an intact PSA with an N-terminus of IVGGVS em leader; the second, an N-1 PSA variant. The recombinant proteins were tested for serine protease activity and for anti-angiogenic activity in vitro and in vivo. RESULTS: The rate of substrate hydrolysis by the intact recombinant PSA was similar to that of PSA isolated and purified from human seminal plasma. In contrast, the N-1 PSA variant lacked serine protease activity. In an endothelial cell migration assay, the concentration that resulted in 50% inhibition (IC(50)) was: 0.5 microM for native PSA, 0.5 microM for intact recombinant protein, and 0.1 microM for the N-1 variant PSA. Both the intact recombinant and the N-1 recombinant PSA inhibited angiogenesis in vivo. CONCLUSIONS: Purified recombinant PSA inhibits angiogenesis, proving the concept that PSA is an anti-angiogenic, and serine protease activity, as determined by synthetic substrate hydrolysis, is distinct from the anti-angiogenic properties of PSA.

Angiogenesis Inhibitors↗

PubMed2003

Multiple idiopathic cervical root resorption: systematic review and report of four cases.

OBJECTIVES: The objectives of this study were to report four cases of multiple idiopathic cervical root resorption and to systematically review the literature on this condition. METHODS: The clinical and radiographic findings and the medical/dental histories of four patients who presented with multiple idiopathic cervical root resorption were recorded. Additionally, 10 references from the literature that reported on 14 patients were reviewed. RESULTS: Multiple idiopathic cervical root resorption was an incidental finding on routine clinical and radiographic examination. There appeared to be no correlation between this type of resorption and any medical/dental finding. Radiographically, multiple idiopathic cervical root resorption was found to begin at the cemento-enamel junction and then either progress to involve the entire cervical region or, at some point, spontaneously arrest. Those cases that progressed to involve the entire cervical region required extraction. The number of teeth that demonstrated this condition ranged from 5 to 24 per patient. More teeth became involved as the condition was followed in time. There was no detectable frequency of occurrence for any particular dental region or tooth among the involved teeth. Of a total of 18 patients, 13 were females whose ages ranged from 7 years to 68 years. Ten of the 18 patients were Caucasian. CONCLUSIONS: Multiple idiopathic cervical root resorption was found most frequently associated with younger females. This condition appeared to be of unknown aetiology and uncertain natural history.

Adult↗

PubMed2003

Intraosseous oral leiomyoma: systematic review and report of one case.

OBJECTIVES: The objectives of this study were to report one case of intraosseous oral leiomyoma and to systematically review the English literature. METHODS: The clinical and radiographic findings of a patient who presented with intraosseous oral leiomyoma were recorded. In addition, 11 references from the English literature that reported 12 patients were reviewed. RESULTS: Thirteen patients (age range 8 months to 71 years; mean 36 years, median 25 years) were reported to present with intraosseous oral leiomyoma. After excluding one patient whose sex was not reported, there were five female patients (42%) and seven males (58%). The majority of patients presented with either no symptoms or with an asymptomatic swelling. Eleven of 13 lesions occurred in the mandible; the most common site was the posterior of the jaw. Radiographically, intraosseous oral leiomyoma was found to present as either a unilocular or multilocular radiolucency with either well defined or ill defined borders and frequent cortical involvement. CONCLUSIONS: Intraosseous oral leiomyoma was found to occur in the mandibular posterior region of relatively young patients, with cortical involvement and a slight male gender preference. Surgical excision was the treatment of choice and no recurrence has been encountered.

Child↗

PubMed2001

Early intestinal Th1 inflammation and mucosal T cell recruitment during acute graft-versus-host reaction.

Little is understood about the earliest cytokine responses and the role(s) of donor CD4 T cells in the intestine during the induced graft-vs-host reaction (GVHR). We investigated the activation and mucosal homing phenotype of the donor CD4 cells and the kinetics of cytokine responses within the intestine and associated lymphoid tissues during early GVHR. Significant frequencies of donor CD4 cells accumulated within recipient Peyer's patches (PP), mesenteric lymph nodes (MLN), lamina propria (LP), and spleen (SP), during the first 9 days of GVHR. Many donor CD4 cells in SP, MLN, and LP expressed CD44 and also expressed de novo the mucosal homing integrin alpha(4)beta(7) (LPAM-1). A large IFN-gamma response occurred by day 3 in cells from PP and MLN, but much later (day 9) in SP and LP cells. IL-10 production by SP and MLN cells was elevated initially but declined substantially by day 9. IL-4 production by SP, MLN, and PP cells was low on day 3 and showed gradual decline in LP by day 9. IL-5 production by LP cells gradually increased in direct contrast to IL-5 production by MLN cells. The MLN CD4 cells showed the most dynamic changes, with high numbers of activated/effector donor CD4 cells and altered cytokine production consistent with a developing Th1 response. The IFN-gamma responses in PP and MLN preceded that of the SP, suggesting an intestinal origin for some Th1 effector cells in GVHR. Donor CD4 T cells apparently acquire the ability to home to the LP during early GVHR.

Acute Disease↗

PubMed2001

Endostatin binds tropomyosin. A potential modulator of the antitumor activity of endostatin.

The mechanism of action of Endostatin, an endogenous inhibitor of angiogenesis and tumor growth, remains unknown. We utilized phage-display technology to identify polypeptides that mimic the binding domains of proteins with which Endostatin interacts. A conformed peptide (E37) was identified that shares an epitope with human tropomyosin implicating tropomyosin as an Endostatin-binding protein. We show that recombinant human Endostatin binds tropomyosin in vitro and to tropomyosin-associated microfilaments in a variety of endothelial cell types. The most compelling evidence that tropomyosin modulates the activity of Endostatin was demonstrated when E37 blocked greater than 84% of the tumor-growth inhibitory activity of Endostatin in the B16-BL6 metastatic melanoma model. We conclude that the E37 peptide mimics the Endostatin-binding epitope of tropomyosin and blocks the antitumor activity of Endostatin by competing for Endostatin binding. We postulate that the Endostatin interaction with tropomyosin results in disruption of microfilament integrity leading to inhibition of cell motility, induction of apoptosis, and ultimately inhibition of tumor growth.

Actin Cytoskeleton↗

PubMed2001

Determination of albumin and myoglobin in dialysate and ultrafiltrate samples by high-performance size-exclusion chromatography.

A high-performance size-exclusion chromatographic method was developed, validated and implemented for simultaneous and quantitative determination of albumin and myoglobin along with inulin, vancomycin and creatinine in dialysate and ultrafiltrate samples from in vitro hemodialysis experiments. The experimental parameters including mobile phase pH, ionic strength, detection wavelength, flow-rate, injection volume were first optimized for the determination of albumin, myoglobin, inulin, vancomycin and creatinine. The peak height ratio and detection limits of the proteins were then comparatively studied at 210, 254 and 280 nm by UV and diode array detection. The method was further validated by evaluating the linearity, precision and accuracy of the proteins. The assay was finally implemented to the simultaneous and quantitative determination of the proteins in dialysate and ultrafiltrate samples.

Albumins↗

PubMed2001

Reciprocal phosphorylation and regulation of endothelial nitric-oxide synthase in response to bradykinin stimulation.

Endothelial nitric-oxide synthase (eNOS) is phosphorylated at Ser-1179 (bovine sequence) by Akt after growth factor or shear stress stimulation of endothelial cells, resulting in increased eNOS activity. Purified eNOS is also phosphorylated at Thr-497 by purified AMP-activated protein kinase, resulting in decreased eNOS activity. We investigated whether bradykinin (BK) stimulation of bovine aortic endothelial cells (BAECs) regulates eNOS through Akt activation and Ser-1179 or Thr-497 phosphorylation. Akt is transiently activated in BK-stimulated BAECs. Activation is blocked completely by wortmannin and LY294002, inhibitors of phosphatidylinositol 3-kinase, suggesting that Akt activation occurs downstream from phosphatidylinositol 3-kinase. BK stimulates a transient phosphorylation of eNOS at Ser-1179 that is correlated temporally with a transient dephosphorylation of eNOS at Thr-497. Phosphorylation at Ser-1179, but not dephosphorylation at Thr-497, is blocked by wortmannin and LY294002. BK also stimulates a transient nitric oxide (NO) release from BAECs with a time-course similar to Ser-1179 phosphorylation and Thr-497 dephosphorylation. NO release is not altered by wortmannin. BK-stimulated dephosphorylation of Thr-497 and NO release are blocked by the calcineurin inhibitor, cyclosporin A. These data suggest that BK activation of eNOS in BAECs primarily involves deinhibition of the enzyme through calcineurin-mediated dephosphorylation at Thr-497.

Androstadienes↗