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Biomedical subjects

Jing Lin

Publications and source records attributed to Jing Lin.

At least 37 records · Page 2Linked to original sources
PubMed2005

Enantioselective fluorescent recognition of a soluble "supported" chiral acid: toward a new method for chiral catalyst screening.

The long-chain aliphatic-group-substituted mandelic acid 3c, which is soluble only in THF and insoluble in water and many polar/nonpolar organic solvents, has been synthesized. This unique solubility allows 3c to be easily isolated from reaction mixtures and makes it potentially useful for catalyst screening. The fluorescent sensors (R)- and (S)-1 can be used to determine the ees of various samples of 3c generated from a series of catalyst screening experiments. The fluorescence measurements correlate well with the conventional HPLC-chiral column analysis. This work demonstrates that the enantioselective fluorescent recognition of organic substrates can lead to a fundamentally new method for chiral catalyst screening. [reaction: see text]

Catalysis↗
PubMed2005

[CD14 genomic polymorphism influences CD14 expression in whole blood culture].

OBJECTIVE: To investigate whether -159C/T promoter polymorphism of the CD14 gene influences the CD14 expression as well as release in whole blood culture. METHODS: One hundred and eighteen healthy human blood donors were included in the present study. CD14 mRNA expression and soluble CD14 levels were measured using a whole blood cell culture model with or without lipopolysaccharide (LPS) stimulation. The CD14 gene polymorphism was determined by polymerase chain reaction and subsequent HaeIII restriction enzyme digestion of the polymerase chain reaction products. TNF-alpha production in the whole blood culture was also measured. RESULTS: Among the 118 individuals, there were 40 subjects homozygous for the T allele (TT), 62 were heterozygous (CT), and 16 had the genotype CC. The CD14 mRNA expression in leukocytes and soluble CD14 levels in supernatant were higher in TT homozygotes and carriers of the genotype TC compared with individuals homozygous for the C allele (P < 0.05 or 0.01). In addition, the highest values of TNF-alpha production were found in TT homozygote [(352 +/- 215) pg/ml] compared with both genotype TC and CC [(261 +/- 163) pg/ml, (198 +/- 122) pg/ml, both P < 0.05]. CONCLUSION: The -159C/T promoter polymorphism of the LPS receptor CD14 may influence the CD14 expression as well as release in whole blood culture, and it might be associated with TNF-alpha response to LPS stimulation.

Adolescent↗
PubMed2005

Quantitative relationships between molecular structures, environmental temperatures and solid vapor pressures of PCDD/Fs.

Based on quantum chemical and topological descriptors, temperature-dependent predictive models for solid vapor pressure (PS) of PCDD/Fs were developed. The inclusion of the two topological descriptors, Kier symmetry index (S0K) and Kier flexibility index (PHI), as predictor variables, improved the statistical significance of models. Thus the entropic factors described by the two topological descriptors play a role in influencing the PS values. The cumulative variance of the dependent variable explained by the PLS components and determined by cross-validation (Qcum2), for the final model, is 0.972, indicating that the model has good predictive ability and robustness, and could be used to estimate PS values of PCDD/Fs at different temperatures. The main factors governing log PS values of PCDD/Fs, from important to less important, are temperature, intermolecular dispersive interactions, entropic factor, and intermolecular dipole-dipole and dipole-induced dipole interactions.

Benzofurans↗
PubMed2005

Inhibitory effect of tumor suppressor p33(ING1b) and its synergy with p53 gene in hepatocellular carcinoma.

AIM: To investigate the inhibitory effect of tumor suppressor p33(ING1b) and its synergy with p53 gene in hepatocellular carcinoma (HCC). METHODS: Recombinant sense and antisense p33(ING1b) plasmids were transfected into hepatoma cell line HepG2 with lipofectamine. Apoptosis, G0/G1 arrest, cell growth rate and cloning efficiency in soft agar of HepG2 were analyzed after transfection. In three hepatoma cell lines with different endogenous p53 gene expressions, the synergistic effect of p33(ING1b) with p53 was analyzed by flow cytometry and luciferase assay was performed to detect the activation of p53 downstream gene p21(WAF1/CIP1). In addition, the expression and mutation rates of p33(ING1b) in HCC tissues were measured by immunohistochemistry and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). RESULTS: Overexpression of p33(ING1b) inhibited cell growth of HepG2, induced more apoptosis and protected cells from growth in soft agar. Combined transfer of p33(ING1b) and p53 gene promoted hepatoma cell apoptosis, G0/G1 arrest and elevated expression of p21(WAF1/CIP1). Immunostaining results showed co-localized P33(ING1b) with P53 protein in HCC tissues and there was a significant relation between protein expression rates of these two genes (P<0.01). Among 28 HCC samples, p33(ING1b) presented a low gene mutation rate (7.1%). CONCLUSION: p33(ING1b) collaborates with p53 in cell growth inhibition, cell cycle arrest and apoptosis in HCC. Loss or inactivation of p33(ING1b) normal function may be an important mechanism for the development of HCC retaining wild-type p53.

Apoptosis↗
PubMed2005

[Biological impact of the COOH-terminal 40 amino acid deletions of hepatitis B virus X protein in hepatocellular carcinoma cells].

OBJECTIVE: To investigate the biological impact of the wild type hepatitis B virus X protein (HBx) and HBx3'-40, an engineered deletion mutant of HBx lacking the last 40 C-terminal amino acids and a transcriptional transactivator on hepatoma cells. METHODS: Human hepatocellular cells of the lines Huh7 and SMMC-7721 were transfected with HBx3'-40 or HBx constructs. The integration of the plasmid DNA and the expression of HBx3'-40 and HBx were confirmed by Neo gene PCR and Western blotting respectively. The growth curves of different cells were obtained by MTT method. Plate clone formation test to calculate the clone formation rate. Flow cytometry (FCM), and Chloramphenicol acetyl transferase (CAT)-ELISA. Male BALB/c mice were divided into 3 groups to be inoculated subcutaneously with plasmids pcDNA3HBx, pcDNA3HBx3'-40, and blank plasmas pcDNA3 as controls. The mice were killed 15 and 30 days after and the tumors were taken out to undergo measurement and immunohistochemistry. RESULTS: Growth curve showed that after transfection the HBx3'-40 group cells grew faster than HBx and pcDNA3 transfected group cells. FCM analysis showed that HBx3'-40 transfection enhanced the progression of G(1) --> S phase in Huh7 cell cycle and HBx did not show such impact. The clone formation rates of pcDNA3HBx3'-40 group was 12.2% +/- 1.4%, significantly higher than those of the pcDNA3HBx, blank vector, and control groups (6.3% +/- 0.7%, 4.1% +/- 0.9%, and 6.1% +/- 1.1% respectively, all P < 0.05) in the Huh7 cells. The situation was the similar in the SMMC-7721 cells: 83% +/- 6% vs.49% +/- 8%, 27% +/- 3%, and 51% +/- 5% respectively (all P < 0.05). The apoptotic rates of SMMC-7721 cells under no serum condition transfected with HBx and HBx3'-40, especially the former, were 12.57% and 9.15%, significantly higher than that of the pcDNA3HBx group. The CAT expression of the pcDNA3HBx-transfected SMMC-7721 cells was 2.913 and 3.652 times those of the pcDNA3HBx3'-40 group and pcDNA3 group. The tumor weights of the mice inoculated with pcDNA3HBx3'-40, pcDNA3HBx, and blank vector-transfected Huh7 cells were 1.2 g +/- 0.17 g, 0.55 g +/- 0.12 g, and 0.48 g +/- 0.15 g respectively. The tumor weights of the mice inoculated with pcDNA3HBx3'-40, pcDNA3HBx, and blank vector-transfected SMMC-7721 cells showed similar features. CONCLUSION: HBx3'-40 protein significantly promote the proliferation of hepatocellular carcinoma cells and is involved in cell apoptosis and invasion, thus supporting the hypothesis that HBx mutants play a key role in hepatocarcinogenesis by modifying the biological functions of HBx. Besides, C-terminal mutants of HBx makes p53 tumor suppressor gene lose its cancerostatic function.

Animals↗
PubMed2005

Antiangiogenic and antitumor activity of a selective PDGFR tyrosine kinase inhibitor, CP-673,451.

CP-673,451 is a potent inhibitor of platelet-derived growth factor beta-receptor (PDGFR-beta) kinase- and PDGF-BB-stimulated autophosphorylation of PDGFR-beta in cells (IC(50) = 1 nmol/L) being more than 450-fold selective for PDGFR-beta versus other angiogenic receptors (e.g., vascular endothelial growth factor receptor 2, TIE-2, and fibroblast growth factor receptor 2). Multiple models have been used to evaluate in vivo activity of CP-673,451 and to understand the pharmacology of PDGFR-beta inhibition and the effect on tumor growth. These models include an ex vivo measure of PDGFR-beta phosphorylation in glioblastoma tumors, a sponge model to measure inhibition of angiogenesis, and multiple models of tumor growth inhibition. Inhibition of PDGFR-beta phosphorylation in tumors correlates with plasma and tumor levels of CP-673,451. A dose of 33 mg/kg was adequate to provide >50% inhibition of receptor for 4 hours corresponding to an EC(50) of 120 ng/mL in plasma at C(max). In a sponge angiogenesis model, CP-673,451 inhibited 70% of PDGF-BB-stimulated angiogenesis at a dose of 3 mg/kg (q.d. x 5, p.o., corresponding to 5.5 ng/mL at C(max)). The compound did not inhibit vascular endothelial growth factor- or basic fibroblast growth factor-induced angiogenesis at concentrations which inhibited tumor growth. The antitumor efficacy of CP-673,451 was evaluated in a number of human tumor xenografts grown s.c. in athymic mice, including H460 human lung carcinoma, Colo205 and LS174T human colon carcinomas, and U87MG human glioblastoma multiforme. Once-daily p.o. x 10 days dosing routinely inhibited tumor growth (ED(50) < or = 33 mg/kg). These data show that CP-673,451 is a pharmacologically selective PDGFR inhibitor, inhibits tumor PDGFR-beta phosphorylation, selectively inhibits PDGF-BB-stimulated angiogenesis in vivo, and causes significant tumor growth inhibition in multiple human xenograft models.

Angiogenesis Inhibitors↗
PubMed2005

Mesenchymal stem cells differentiate into an endothelial phenotype, enhance vascular density, and improve heart function in a canine chronic ischemia model.

BACKGROUND: Bone marrow-derived stem cells are under investigation as a treatment for ischemic heart disease. Mesenchymal stem cells (MSCs) have been used preferentially in the acute ischemia model; data in the chronic ischemia model are lacking. METHODS AND RESULTS: Twelve dogs underwent ameroid constrictor placement. Thirty days later, they received intramyocardial injections of either MSCs (100x10(6) MSCs/10 mL saline) (n=6) or saline only (10 mL) (controls) (n=6). All were euthanized at 60 days. Resting and stress 2D echocardiography was performed at 30 and 60 days after ameroid placement. White blood cell count (WBC), C-reactive protein (CRP), creatine kinase MB (CK-MB), and troponin I levels were measured. Histopathological and immunohistochemical analyses were performed. Mean left ventricular ejection fraction was similar in both groups at baseline but significantly higher in treated dogs at 60 days. WBC and CRP levels were similar over time in both groups. CK-MB and troponin I increased from baseline to 48 hours, eventually returning to baseline. There was a trend toward reduced fibrosis and greater vascular density in the treated group. MSCs colocalized with endothelial and smooth muscle cells but not with myocytes. CONCLUSIONS: In a canine chronic ischemia model, MSCs differentiated into smooth muscle cells and endothelial cells, resulting in increased vascularity and improved cardiac function.

Animals↗
PubMed2005

Trefoil factor family-3 is associated with aggressive behavior of colon cancer cells.

BACKGROUND AND AIM: Trefoil factor family 3 (TFF3) is expressed by intestinal epithelial cells and it mainly functions to protect the mucosa from injury. Expression of TFF3 has been correlated with a poor prognosis in patients with cancer, but little is known about whether TFF3 directly contributes to the malignant behavior of cancer cells. The present study was conducted to determine whether TFF3 expression contributes to the malignant behavior of cancer cells in vitro and in vivo. METHODS: Two subclones of a metastatic rat colorectal cancer cell line, demonstrated previously to manifest aggressive (LN cells) and non-aggressive (LP cells) growth in vivo, were analyzed for expression of TFF3 and tested in assays of cancer cell migration, invasion, and apoptosis in vitro, and mortality in vivo. RESULTS: The aggressive LN cell line endogenously expressed TFF3 and supported the transcription of a TFF3 promoter-driven reporter construct, whereas the non-aggressive LP cell line did not express TFF3. LN cells demonstrated enhanced migration, invasion, and less apoptosis compared to LP cells. Transfecting TFF3 into LP cells enhanced their ability to migrate, invade, block apoptosis, and behave more aggressively in vivo, thereby resembling the phenotype of LN cells. CONCLUSIONS: In rat colon cancer cells, both endogenous and constitutive expression of TFF3 correlates with an aggressive phenotype. These data provide direct evidence that TFF3 contributes to the malignant behavior of cancer cells.

Animals↗
PubMed2005

Is there an advantage of using pressure support ventilation with volume guarantee in the initial management of premature infants with respiratory distress syndrome? A pilot study.

OBJECTIVE: To evaluate the feasibility of using the pressure support ventilation with volume guarantee (PSV-VG) as an initial ventilatory mode in preterm infants with respiratory distress syndrome (RDS) after surfactant treatment to achieve accelerated weaning of peak inspiratory pressure (PIP) and mean airway pressure (MAP). STUDY DESIGN: Initial 24-hour ventilatory parameters were compared in two groups of preterm infants managed by PSV-VG and the synchronized intermittent mandatory ventilation (SIMV) mode in a randomized controlled pilot study after surfactant treatment for RDS. A total of 16 babies were randomized to PSV-VG (1198+/-108 g [mean+/-SEM]; 27.9+/-0.6 weeks) and 18 babies to SIMV (birth weight 1055+/-77 g; gestational age 27.4+/-0.5 weeks). Repeated measures analysis of variance was used to compare serial values of PIP and MAP in the two groups. RESULTS: The PIP and MAP decreased over time (p<0.001) during the first 24 hours after surfactant administration in both groups but the decrease in MAP was faster in the SIMV group compared to PSV-VG group (p=0.035). The median numbers of blood gases during the first 24 hours were four and two in the SIMV and PSV-VG groups, respectively (p<0.001). The overall outcomes were not significantly different between the two groups. CONCLUSION: PSV-VG did not offer any ventilatory advantage over SIMV in the initial management of surfactant-treated premature newborns with RDS except for minimizing the number of blood gases.

Blood Gas Analysis↗
PubMed2005

Short-chain fatty acid induces intestinal mucosal injury in newborn rats and down-regulates intestinal trefoil factor gene expression in vivo and in vitro.

BACKGROUND: Luminal administration of short-chain fatty acids (SCFAs) induces dose-dependent intestinal mucosal injury in newborn rats. However, the mechanism underlying the injurious effects of SCFAs on intestinal mucosa in neonates is unclear. Intestinal trefoil factor (ITF) is a factor important for the maintenance and repair of the intestinal mucosal barrier. Regulation of ITF gene expression by SCFAs may be involved as one of the mechanisms. OBJECTIVES: To examine the effect of butyrate-induced colonic injury on ITF gene expression in vivo and to determine the molecular mechanisms underlying the butyrate regulation of ITF gene expression in vitro. METHODS: Whole-section colonic tissues from 9- to 10-day-old Sprague-Dawley rats that have received butyric acid at two different concentrations (150 mmol/L and 300 mmol/L) and for different time periods were processed for total RNA extraction and Northern blot analysis. Littermates that received normal saline or lactic acid at 300 mmol/L served as controls. The effect of butyrate on ITF gene expression was also examined in vitro with human colonic epithelial LS 174T cells. To further define ITF gene regulation by butyrate, transient transfection assays were performed on a 930 bp human ITF promoter-luciferase reporter gene plasmid in LS174T cells with or without the presence of butyrate. RESULTS: Concurrent with mucosal injury, butyric acid inhibited ITF gene expression in colonic tissues of newborn rats as well as in intestinal epithelial cells in a dose- and time-dependent manner. Furthermore, butyrate reduced ITF promoter report gene activity in transfected LS174T cell, suggesting that butyric acid regulation of ITF gene is by way of a specific ITF promoter. CONCLUSIONS: Butyric acid induced-intestinal mucosal injury in newborn rats is associated with down-regulation of ITF gene expression. The changes in ITF gene expression in vivo may play a role in the pathogenesis of SCFA-induced intestinal mucosal injury.

Animals↗
PubMed2005

Vectored Gag and Env but not Tat show efficacy against simian-human immunodeficiency virus 89.6P challenge in Mamu-A*01-negative rhesus monkeys.

Simian-human immunodeficiency virus (SHIV) challenge studies in rhesus macaques were conducted to evaluate the efficacy of adenovirus-based vaccines in the context of different major histocompatibility complex class I genetic backgrounds and different vaccine compositions. Mamu-A*01 allele-negative rhesus monkeys were immunized with one of the following vaccine constructs: (i) replication-defective recombinant adenovirus type 5 (Ad5) expressing human immunodeficiency virus type 1 (HIV-1) Tat (Ad5/HIVTat); (ii) Ad5 vector expressing simian immunodeficiency virus (SIV) Gag (Ad5/SIVGag); (iii) Ad5 vector expressing the truncated HIV-1(jrfl) Env, gp140 (Ad5/gp140_jrfl); (iv) Ad5 vector expressing the SHIV-89.6P gp140 (Ad5/gp140_89.6P); or (v) the combination of Ad5/SIVGag and Ad5/gp140_jrfl. Following intravenous challenge with SHIV-89.6P, only those cohorts that received vaccines expressing Gag or Env exhibited an attenuation of the acute viremia and associated CD4-cell lymphopenia. While no prechallenge neutralizing antibody titers were detectable in either Ad5/gp140-vaccinated group, an accelerated neutralizing antibody response was observed in the Ad5/gp140_89.6P-vaccinated group upon viral challenge. The set-point viral loads in the Ad5/SIVGag- and Ad5/gp140_jrfl-vaccinated groups were associated with the overall strength of the induced cellular immune responses. To examine the contribution of Mamu-A*01 allele in vaccine efficacy against SHIV-89.6P challenge, Mamu-A*01-positive monkeys were immunized with Ad5/SIVGag. Vaccine-mediated protection was significantly more pronounced in the Mamu-A*01-positive monkeys than in Mamu-A*01-negative monkeys, suggesting the strong contributions of T-cell epitopes restricted by the Mamu-A*01 molecule. The implications of these results in the development of an HIV-1 vaccine will be discussed.

AIDS Vaccines↗
PubMed2005

Combination of acute preoperative plateletpheresis, cell salvage, and aprotinin minimizes blood loss and requirement during cardiac surgery.

Acute preoperative plateletpheresis (APP), cell salvage (CS) technique, and the use of aprotinin have been individually reported to be effective in reducing blood loss and blood component transfusion while improving hematological profiles in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). In this prospective randomized clinical study, the efficacy of these combined approaches on reducing blood loss and transfusion requirements was evaluated. Seventy patients undergoing primary coronary artery bypass grafting (CABG) were randomly divided into four groups: a control group (group I, n = 10) did not receive any of the previously mentioned approaches. An APP and CS group (group II, n = 20) experienced APP in which preoperative platelet-rich plasma was collected and reinfused after reversal of heparin, along with the cell salvage technique throughout surgery. The third group (group III, n = 22) received aprotinin in which 5,000,000 KIU Trasylol was applied during surgery, and a combination group (group IV, n = 18) was treated with all three approaches, i.e., APP, CS, and aprotinin. Compared with group I (896+/-278 mL), the postoperative total blood loss was significantly reduced in groups II, III, and IV (468+/-136, 388+/-122, 202+/-81 mL, respectively, p < 0.05). The requirements of packed red blood cells in the three approached groups (153+/-63, 105+/-178, 0+/-0 mL, respectively) also were reduced when compared with group I (343+/-118 mL, p < 0.05). In group I, six patients (6/10) received fresh-frozen plasma and three patients (3/10) received platelet transfusion, whereas no patients in the other three groups required fresh-frozen plasma and platelet. In conclusion, both plateletpheresis concomitant with cell salvage and aprotinin contribute to the improvement of postoperative hemostasis, and the combination of these two approaches could minimize postoperative blood loss and requirement.

Acute Disease↗
PubMed2005

[Killing effect of 131I-Herceptin on breast cancer cell lines in vitro].

OBJECTIVE: To study the specific killing effect of (131)I-labeled Herceptin on breast cancer cell lines positive for Her-2 expression. METHODS: Anti-Her-2 monoclonal antibody Herceptin was labeled with (131)I by means of IODO-GEN, and the killing effects of Herceptin on SK-BR-3, MCF-7 and A549 cell lines expressing Her-2 were evaluated with MTT assay. RESULTS: (131)I-Herceptin had immunoactivity had to that of Herceptin but possessed stronger killing effects on the cell lines expressing Her-2 than Herceptin and (131)I used alone (P<0.05). Its killing effect on cell lines negative or only weakly positive for Her-2 expression was similar to that of (131)I and Herceptin. CONCLUSION: (131)I-Herceptin can specifically kill Her-2-positive cancer cells in vitro.

Antibodies, Monoclonal↗
PubMed2005

[Effect of Chinese herbal medicine on patients with primary hepatic carcinoma in III stage during perioperational period: a report of 42 cases].

OBJECTIVE: To investigate the synergetic effect of general therapy of Chinese herbal medicine with surgical operation. METHODS: Fourty-two patients in the integrative group were treated with jiedu xiaozheng yin for 7 days before operation, and fuzheng yiliu recipe after operation for 2 years, and 30 patients in the control group underwent operation alone. Their cellular immune function, survival rate and recurrence rate were compared and analyzed. RESULTS: The accumulative survival rate of 6-month, 12-month, 24-month and 36-month in the integrative group was 97.6%(41/42), 85.7%(36/42), 52.3% (22/42) and 45.5(17/42)% respectively and those in the control group 96.7% (29/30), 83.3% (25/30), 50.0% (15/30) and 30.0% (9/30), respectively, among them the 36-month survival rate was significantly different between the two groups (P < 0.05). The 24-month recurrence rate in the two groups was 54.8% and 80.0% respectively, the difference between the two was significant (P < 0.05). CONCLUSION: Administration of compound Chinese herbal medicine in peri-operational period has definite effect on primary hepatic carcinoma in III stage, it can improve patients' immune function, decrease the recurrence rate and increase the cumulative survival rate.

Adult↗
PubMed2005

[Hepatitis B virus and deletion of its COOH-terminal forty amino acids: proliferative impact on hepatoma cell line SMMC-7721].

OBJECTIVE: To explore the biological impact of 40 amino acid deletion at the C-terminal of hepatitis B virus X on the proliferation of hepatoma cells. METHODS: Cells of SMMC-7721 hepatoma cell line were transfected with HBx and its derivative HBx3'-40, harboring the 40 amino acid deletion at the distal C-terminal region. Cell growth curve, colony formation in soft agar plate and tumorigenesis assay in nude mice were used to observe the alterations induced by the transfection of HBx and HBx3'-40. The expression level of PCNA in tumor cells was also investigated. RESULTS: The growth rates of the cells transfected with HBx and HBx3'-40 were markedly increased as compared with that of the control group. The colony formation rates were enhanced in the cells transfected with HBx(48.7 +/- 8.1) and HBx3'-40 (82.8+/-6.0), comparing with the control (26.9 +/- 3.5) %. In the tumorigenic assay, the size and weight of tumors were significantly increased in the cells transfected with HBx (0.412 +/- 0.212, 0.395 +/- 0.159) % and HBx3'-40 (1.476 +/- 0.232, 0.987 +/- 0.279) %, as compared with the control group (0.051 +/- 0.024, 0.033 +/-0.004) %. The expression level of PCNA in tumors was increased in both HBx (59.00 +/- 2.58) % and HBx3'-40 (69.25 +/- 3.77) % transfected cells, comparing with the control (37.67 +/- 2.52) %. Overall, the cells transfected with HBx3'-40 demonstrated the highest proliferative capacity. CONCLUSION: The deletion of 40 amino acids in the C-terminal of HBx is correlated with an enhanced proliferation of hepatoma cells and may play an important role in the malignant transformation of the liver.

Amino Acid Sequence↗
PubMed2004

Short-chain fatty acids induce colonic mucosal injury in rats with various postnatal ages.

Short chain fatty acids (SCFAs) may play a role in the pathogenesis of neonatal necrotizing enterocolitis. To evaluate the injurious effect of SCFAs on the colonic mucosa of rats at various postnatal developmental stages, we studied a total of 170 newborn Sprague-Dawley rats at postnatal ages days 3, 9, and 23. A 1.8-F silastic catheter or umbilical catheter was inserted rectally deep into the proximal colon of the rats. Rats from each of the three postnatal age groups were randomly divided to receive one of the following distinct SCFA solutions: acetic acid, butyric acid, propionic acid, or a mixture of above SCFAs solutions. An additional subgroup of rats from each of the age groups received normal saline as a control. The concentration of each SCFA solution was 300 mM, and the pH of all solutions was adjusted to 4.0. The volume of administered solution was 0.1 mL/10 g of body weight. After 24 h, all rats were killed and the daily weight change was recorded and proximal colon was collected for histologic examination. A histologic injury score was used to quantify the severity of mucosal injury. The severity of mucosal injury induced by luminal SCFAs administration decreased as the rats matured; by postnatal day 23, the injury caused by SCFAs was minimal. Thus, the severity of the colonic mucosal injury induced by luminal SCFAs is maturation dependent; the immature state of the mucosal defense in early postnatal age in newborn rat may explain its greater vulnerability to luminal SCFAs.

Acetic Acid↗
PubMed2004

The major human structural IgE epitope of the Brazil nut allergen Ber e 1: a chimaeric and protein microarray approach.

A protein microarray system containing different dilutions of 77 related and non-related proteins was used to show that IgE from subjects allergic to Brazil nut specifically recognise the seed 2S albumin protein (Ber e 1). Further, correctly folded chimaeric 2S albumin proteins containing structural epitope replacement were constructed and directed to the secretion pathway of the methylotropic yeast Pichia pastoris. Through the use of a chimaeric protein microarray system together with sera from a panel of 18 well-characterised Brazil nut allergic subjects, a structural IgE epitope of Ber e 1 was mapped to a helix-loop-helix region. The same structural region has been previously reported as the immunodominant region in related food allergens by different techniques. In conclusion, the combination of chimaeric proteins and protein microarrays will greatly facilitate the screening of a large number of individuals for a particular structural epitope and help to further our understanding of how proteins are recognised by the adaptive immune system.

2S Albumins, Plant↗