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Biomedical subjects

Jun Li

Publications and source records attributed to Jun Li.

At least 55 records · Page 3Linked to original sources
PubMed2006

Cloning and expression of the human augmenter of liver regeneration at low temperature in Escherichia coli.

Acute and chronic hepatic failure is a devastating illness of varied causes with considerable mortality. Human augmenter of liver regeneration (hALR) is a hepatotrophic protein and the unique cytokine which can specially stimulate hepatic origin cells to grow regardless of genus. It has been proven that ALR can promote regeneration and avoid all kinds of injury in rat and canine models. In this study, the recombinant protein hALR was expressed successfully with recombinant prokaryotic expression vector pET28a(+) in Escherichia coli BL21 (DE3). We constructed the recombinant expression vector pET28a(+)/hALR with a full-length cDNA encoding hALR protein from normal human liver tissue by one-step reverse transcription-polymerase chain reaction and his-tag recognition sequence encoding polyhistidine (6 x His). Under IPTG (isopropyl-beta-d-thiogalactopyranoside) induction for 2 h at 37 degrees C, recombinant protein hALR was expressed. The expression of recombinant polyhistidine-tagged hALR was increased under low temperature and was confirmed that the temperature of 23 degrees C was the most suitable IPTG induction condition. Under low temperature induction of IPTG, recombinant protein can be expressed as a soluble protein. Recombinant protein hALR was also purified with His Bind Kits and characterized with SDS-PAGE and Western blotting. The results showed that recombinant hALR could be expressed as a soluble protein under low temperature induction of IPTG. The successful expression of ALR in E. coli makes it possible to further study its biological function and purified recombinant hALR could be developed into a new anti-hepatic damage product.

Base Sequence↗
PubMed2006

Degradation of environmental endocrine disruptor di-2-ethylhexyl phthalate by a newly discovered bacterium, Microbacterium sp. strain CQ0110Y.

In this study di-2-ethylhexyl phthalate (DEHP)-degradation strain CQ0110Y was isolated from activated sludge. According to the biophysical/biochemical characteristics and analysis of 16S rDNA, the strain was identified as Microbacterium sp. The results of this study showed the optimal pH value and optimal temperature which influenced the degradation rate in wastewater: pH 6.5-7.5, 25-35 degrees C. Kinetics of degradation reaction had been performed at different initial concentrations and different time. Analyzed with SPSS10.0 software, the DEHP degradation can be described as the same exponential model when the initial DEHP concentration was lower than 1,350 mg/l. The kinetics equation was ln C = -0.4087t + A, with the degradation half life of DEHP in wastewater (1.59 days). To the best of our knowledge, this is the first reported case of DEHP degradation by Microbacterium sp. strain.

Actinomycetales↗
PubMed2006

Concentrations, enantiomeric compositions, and sources of HCH, DDT and chlordane in soils from the Pearl River Delta, South China.

Concentrations, and enantiomeric compositions of HCH, DDT and chlordane in 74 soils of the Pearl River Delta, South China were investigated. The mean concentrations of HCHs and DDTs descended in the order: crop soils>paddy soils>natural soils. The concentrations (ng/g dw) of p,p'-DDE, p,p'-DDT, p,p'-DDD and o,p'-DDT in crop soils were 0.14-231, 0.07-315, 0.5. An EF value >0.5 generally suggested a preferential degradation of the (-) enantiomers of both TC and CC. The racemic alpha-HCH observed in the soils with higher HCH concentrations indicated that the transformation from gamma-HCH (e.g. lindane) to alpha-HCH may be an important process in the soils. The isomer ratios of p,p'-DDT/(DDE+DDD), o,p'-DDT/p,p'-DDT and enantiomeric compositions of o,p'-DDT suggested that both illegal use of technical DDT and the DDT impurity in dicofol may be responsible for the freshly DDT input in the region. The sources of DDTs were drawn by principal component analysis-multiple linear regression (PCA-MLR). The relative contributions of dicofol-type DDT, residues, and fresh technical DDT were estimated to be 55%, 21% and 17%, respectively. In addition, CC was found to degraded faster than TC in soils from the Pearl River Delta. The study demonstrated that the combination of isomer ratios and enantiomeric composition analysis may provide critical information on the potential sources and fate of organochlorine pesticides in soil.

China↗
PubMed2006

[Association between serotonin 1D gene polymorphisms and attention deficit hyperactivity disorder comorbid or not comorbid disruptive behavior disorder].

OBJECTIVE: To investigate the relationship between two HTR1D gene polymorphisms, that is 1350T > C and 1236A > G polymorphisms, and attention deficit hyperactivity disorder (ADHD) comorbid or not comorbid disruptive behavior disorder (DBD). METHODS: Blood samples were taken from 90 trios with probands of ADHD comrbid DBD and 182 trios with probands of ADHD not comorbid DBD. DNA was extracted. 1350T > C and 1236A > G were genotyped by restriction fragment length polymorphism analysis. Transmit/disequilibrium test and haplotype analysis were used to test the association of the two polymorphisms of HTR1D gene and ADHD comorbid or not comorbid disruptive behavior disorder (DBD) separately. RESULTS: 1350T allele(chi2 = 3.67, P = 0.055)and G/T haplotype(chi2 = 3.84, P = 0.050)were overtransmitted, while 1350C allele(chi2 = 3.67, P = 0.055) and G/C haplotype(chi2 = 5.22, P = 0.022)were undertransmitted to probands of ADHD with DBD. No biased transmission of any allele and haplotype was found in families with probands of ADHD without DBD. CONCLUSION: ADHD comorbid or not comorbid DBD are different at the level of HTR1D gene polymrohisms of 1350T > C and 1236A > G. The current results indicate that ADHD with DBD has more heritable backgrounds when compared with ADHD without DBD.

Adolescent↗
PubMed2006

[Effects of different methods of anesthesia and analgesia on early postoperative cognitive dysfunction after non-cardiac surgery in the elderly].

OBJECTIVE: To determine if different methods of anesthesia and analgesia will influence the incidence of early postoperative cognitive dysfunction (POCD) after non-cardiac surgery in the elderly. METHODS: One hundred and three elderly patients undergoing elective abdominal surgery were randomly allocated to receive either general anesthesia followed with postoperative intravenous analgesia (general anesthesia group, 53 cases) or combined general-epidural anesthesia followed with postoperative epidural analgesia (combined general-epidural anesthesia group, 50 cases). Cognitive function was assessed preoperatively and 7 days postoperatively using a battery of nine neuropsychological tests. A postoperative deficit in any test was defined when decline by more than or equal to 20% of the preoperative value of that test occurred. Any patient showing deficit in 2 or more tests was defined as having postoperative cognitive dysfunction. RESULTS: Ninety-two patients completed both preoperative and postoperative neuropsychological tests. On day 7, POCD occurred in 20/45 patients (44.4%) in the general anesthesia group and in 23/47 patients (48.9%) in the combined general-epidural anesthesia group. No significant difference was found between the two groups. Logistic regression analysis showed that short duration of education and operation of general surgery were independent risk factors of the occurrence of early POCD. CONCLUSION: Early POCD occurred in 46.7% of the elderly patients undergoing abdominal surgery. However, there was no significant difference between the effects of two different methods of anesthesia and postoperative analgesia on the incidence of POCD. Short duration of education and operation of general surgery were risk factors of early POCD.

Abdominal Cavity↗
PubMed2006

Atomic force microscopy study of different effects of natural and semisynthetic beta-lactam on the cell envelope of Escherichia coli.

The effects of native and semisynthetic beta-lactam on the surface of E. coli cells were investigated using tapping mode atomic force microscopy (AFM). These studies were done on both single cell and cell colonies. This allowed us to achieve a complete understanding of the effects, since previous related AFM analysis was only performed on single cells. Our results indicated that although amoxycillin and penicillin could both induce nanoporous damage to the envelope of E. coli, the distribution of the pores was different: those induced by penicillin were randomly distributed on the cell surface, while those induced by amoxycillin were far more numerous and mainly on the two ends of the cell. These findings could explain why the effect of amoxycillin is stronger than that of native penicillin. Ofloxacin was used as a control due to its inactive membrane, and no cell wall damages were observed. Our results demonstrate that AFM is a useful tool in discerning and verifying antibiotic mechanisms and can be helpful to explain the relationship between chemical structure and the function of antibiotics.

Anti-Bacterial Agents↗
PubMed2006

[Change in the joint line after total knee arthroplasty].

OBJECTIVE: To investigate the change in joint line after knee arthroplasty. METHODS: A total of 43 patients had 25 primary cruciate-retaining total knee replacements (Link Gemini MKII) and 25 rotational knee replacements (Link Endo-Model Rotational Knee System) sacrificing collateral ligaments and cruciate ligaments. Lateral radiographs were made both preoperatively and postoperatively. The change in the relative position of the joint line preoperatively and postoperatively was defined as the difference between the perpendicular distance from the weight-bearing surface of the tibial plateau to the tibial tubercle of the natural tibia (JL) and perpendicular distance from the weight-bearing surface of the prosthetic tibial component to the tibial tubercle (JL'). This distance was JL'-JL. The statistical differences between 2 groups were analyzed. RESULTS: The distance of JL'-JL was 2.0 mm (-1.3 - 7.2 mm) in 22 patients with Gemini replacement, whereas the distance was 3.1 mm (-1.5 - 12.3 mm) in the other patients with rotational knee system. The difference was significant. CONCLUSIONS: If the collateral ligaments and cruciate ligaments are removed during the knee replacement operations, the prosthetic joint line is likely to be malpositioned proximally. The fibular styloid and medial or lateral epicondylar reference points can be used to determine proper position of the joint line during operation.

Aged↗
PubMed2006

A pharmacokinetic formalism explicitly integrating the patient drug compliance.

The adherence phenomenon is now well recognized to seriously compromise drug efficacy. In this paper, we analyze the role of compliance through drug intake history as an integral part of the pharmacokinetic process. Being concerned with what is accessible in medical practice, we develop a stochastic approach to model the drug intake behavior that we combine with a conventional pharmacokinetic model in order to investigate the effect of drug intake history on the pharmacokinetic time-course. For this purpose, we explicitly formalize the plasma concentration variations for the most common administration routes. This analytical approach allows to characterize drug concentration variations directly inherited from patient compliance.

Animals↗
PubMed2006

[Meta-analysis of short-term efficacy and safety after laparoscopic resection for colorectal cancer].

OBJECTIVE: To evaluate the short-term curative effects and safety of laparoscopic resection (LR) in treatment of colorectal cancer. METHODS: The databases PubMed, Embase, CCTR, and CBMdisc were retrieved and 15 medical journals published in different countries were retrieved manually to search the literatures related to randomized controlled trials (RCTs) on the comparison between the effects and safety of LR and open resection (OR) in treatment of colorectal cancer that were published before the end of 2005. After selected based on the inclusion and exclusion standards, the valid literature were appraised by 2 reviewers independently. RESULTS: Nine articles, with a mean quality score of 7.6 +/- 0.6 were included into the meta-analysis. The baseline characteristics of the LR group were similar to those of the OR group. In comparison with the OR group, the incision length of the LR group was shorter by 12 cm [95% CI (-13.51, -10.49), P < 0.01], blood loss was less by 75 ml [95% CI (-86.06, -62.99), P < 0.01], intensity of pain in the first day after operation was lower [weight mean deviation = -0.80, 95% CI (-1.26, -0.34), P < 0.01], parenteral narcotic requirement was lower [standard mean deviation = -0.31, 95% CI (-0.42, -0.21), P < 0.01], and average times before the post-operative first flatus, first bowel movement, and diet resumption, and discharge were all shorter (all P < 0.05); however, the operation time was longer by 42 min [95% CI (32.18, 52.50), P < 0.01]. There were no significant differences in the length of resected specimen, positive rate of resection margin, number of retrieved lymph nodes, and morbidity rates of intra-operative and post-operative complications. CONCLUSION: With faster recovery and less pain compared with OR, LR is safe and effective in the treatment of colorectal cancer.

Colorectal Neoplasms↗
PubMed2006

Isolation and characterization of a novel thermostable non-specific lipid transfer protein-like antimicrobial protein from motherwort (Leonurus japonicus Houtt) seeds.

In screening for potent antimicrobial proteins from plant seeds, a novel heat-stable antimicrobial protein, designated LJAMP2, was purified from seeds of the motherwort (Leonurus japonicus Houtt), a medicine herb, with a procedure involving cation exchange chromatography on a CM FF column, and reverse phase HPLCs on C8 column and C18 column. LJAMP2 exhibited a molecular mass of 6.2 kDa determined. Automated Edman degradation determined the partial N-terminal sequence of LJAMP2 to be NH2-AIGCNTVASKMAPCLPYVTGKGPLGGCCGGVKGLIDAARTTPDRQAVCNCLKTLAKSYSG, which displays homology with plant non-specific lipid transfer proteins (nsLTPs). In vitro bioassays showed that LJAMP2 inhibits the growth of a variety of microbes, including filamentous fungi, bacteria and yeast. The growth of three phytopathogenic fungi, Alternaria brassicae, Botrytis maydis, and Rhizoctonia cerealis, are inhibited at 7.5 microM of LJAMP2, whereas Bacillus subtilis is about 15 microM. The IC(50) of LJAMP2 for Aspergillus niger, B. maydis, Fusarium oxysporum, Penicillium digitatum and Saccharomyces cerevisiae are 5.5, 6.1, 9.3, 40.0, and 76.0 microM, respectively.

Amino Acid Sequence↗
PubMed2006

B lymphocytes from early vertebrates have potent phagocytic and microbicidal abilities.

The present paradigm dictates that phagocytosis is accomplished mainly by 'professional' phagocytes (such as macrophages and monocytes), whereas B cells lack phagocytic capabilities. Here we demonstrate that B cells from teleost fish have potent in vitro and in vivo phagocytic activities. Particle uptake by B cells induced activation of 'downstream' degradative pathways, leading to 'phagolysosome' formation and intracellular killing of ingested microbes. Those results indicate a previously unknown function for B cells in the innate immunity of these primitive animals. A considerable proportion of Xenopus laevis B cells were also phagocytic. Our findings support the idea that B cells evolved from an ancestral phagocytic cell type and provide an evolutionary framework for understanding the close relationship between mammalian B lymphocytes and macrophages.

Aeromonas hydrophila↗
PubMed2006

Major myelin protein gene (P0) mutation causes a novel form of axonal degeneration.

Mutations in the major peripheral nervous system (PNS) myelin protein, myelin protein zero (MPZ), cause Charcot-Marie-Tooth Disease type 1B (CMT1B), typically thought of as a demyelinating peripheral neuropathy. Certain MPZ mutations, however, cause adult onset neuropathy with minimal demyelination but pronounced axonal degeneration. Mechanism(s) for this phenotype are unknown. We performed an autopsy of a 73-year-old woman with a late-onset neuropathy caused by an H10P MPZ mutation whose nerve conduction studies suggested severe axonal loss but no demyelination. The autopsy demonstrated axonal loss and reorganization of the molecular architecture of the axolemma. Segmental demyelination was negligible. In addition, we identified focal nerve enlargements containing MPZ and ubiquitin either in the inner myelin intralaminar and/or periaxonal space that separates axons from myelinating Schwann cells. Taken together, these data confirmed that a mutation in MPZ can cause axonal neuropathy, in the absence of segmental demyelination, thus uncoupling the two pathological processes. More important, it also provided potential molecular mechanisms as to how the axonal degeneration occurred: either by disruption of glial-axon interaction by protein aggregates or by alterations in the molecular architecture of internodes and paranodes. This report represents the first study in which the molecular basis of axonal degeneration in the late-onset CMT1B has been explored in human tissue.

Adult↗
PubMed2006

Exploring candidate genes for human brain diseases from a brain-specific gene network.

It is believed that large numbers of genes are involved in common human brain diseases. Here, we propose a novel computational strategy for simultaneously identifying multiple candidate genes for genetic human brain diseases from a brain-specific gene network-level perspective. By integrating diverse genomic and proteomic datasets based on Bayesian statistical model, we built a large-scale human brain-specific gene network. Based on this network and minor prior knowledge of a specific brain disease, we can effectively identify multiple candidate genes for this disease. When four known Alzheimer's disease genes were used as the prior knowledge, among the top 46 high-scoring genes that we have found, 37 were previously reported to be associated with Alzheimer's disease. And the higher score a gene has, the more likely this gene is a disease-related one. The results suggest that the proposed method is effective, convenient, and applicable in the future genetic studies.

Alzheimer Disease↗
PubMed2006

Association between polymorphisms in serotonin 2C receptor gene and attention-deficit/hyperactivity disorder in Han Chinese subjects.

Attention deficit hyperactivity disorder (ADHD) is much more frequent in males than females, so several genes on the X chromosome (e.g., MAOA and MAOB) have been pursued as candidates for influencing risk for the disorder. HTR2C is also located on the X chromosome. In the current study, we examined the relationship between the C-759T and G-697C polymorphisms of HTR2C and ADHD in 488 Han Chinese families. Transmission Disequilibrium Test (TDT) analysis showed that the -759C allele, the -697G allele, and haplotype -759C/-697G were significantly over-transmitted to affected probands, while haplotypes -759C/-697C and -759T/-697C were under-transmitted. When families were divided into three subtypes according to the diagnosis of probands, the -697G allele and haplotype -759C/-697G were significantly over transmitted to ADHD-C probands, while haplotype -759T/-697C was under-transmitted to these individuals; however, no biased transmission of any allele or haplotype was observed for probands with ADHD-I, suggesting that different subtypes of ADHD have different genetic influences. Our findings highlight the need to explore the role of 5-HT2C receptor dysfunction in the pathogenesis of ADHD.

Attention Deficit Disorder with Hyperactivity↗
PubMed2006

Late onset of severe graft-versus-host disease following liver transplantation.

Graft versus host disease (GVHD) is an uncommon but lethal complication following liver transplantation that results from the engraftment of T lymphocytes associated with the liver graft. It usually occurs 2 to 6 weeks after the procedure. We herein report a case of late onset of severe GVHD 4 months after cadaveric liver transplantation for hepatocellular carcinoma in a 54-year-old woman, which was characterized by refractory diarrhea and abdominal pain. Moreover we discuss risk factors of GVHD including the recipient age and cytomegalovirus (CMV) infection.

Abdominal Pain↗
PubMed2006

Reactions of cerium atoms and dicerium molecules with CO: formation of cerium carbonyls and photoconversion to CO-activated insertion molecules.

Reactions of cerium with carbon monoxide molecules in solid argon have been studied using matrix isolation infrared absorption spectroscopy. The cerium carbonyls CeCO and Ce2CO are produced spontaneously on annealing and they are photochemically rearranged to the CCeO and c-Ce2(mu-C)(mu-O) isomers, where Ce and Ce2 are inserted into the CO triple bond. Theoretical calculations indicate that CeCO is an end-on-bonded carbonyl with a quintet ground state, whereas Ce2CO is a rare dinuclear lanthanide carbonyl complex with CO serving as an asymmetrically bridged, side-on ligand. The CCeO molecule was theoretically characterized to have a linear structure with a singlet ground state. Evidence is also presented for the CeCO- anion and other cerium carbonyls with higher coordination numbers.

Carbon Monoxide↗