Induction of monoclonal antibodies with predefined epitope-specificity by epitope-vaccines.
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AIDS Vaccines↗
Biomedical subjects
H Tian
Publications and source records attributed to H Tian.
Automatic segmentation algorithm for the extraction of lumen region and boundary from endoscopic images.
A new segmentation algorithm for lumen region detection and boundary extraction from gastro-intestinal (GI) images is presented. The proposed algorithm consists of two steps. First, a preliminary region of interest (ROI) representing the GI lumen is segmented by an adaptive progressive thresholding (APT) technique. Then, an adaptive filter, the Iris filter, is applied to the ROI to determine the actual region. It has been observed that the combined APT-Iris filter technique can enhance and detect the unclear boundaries in the lumen region of GI images and thus produces a more accurate lumen region, compared with the existing techniques. Experiments are carried out to determine the maximum error on the extracted boundary with respect to an expert-annotated boundary technique. Investigations show that, based on the experimental results obtained from 50 endoscopic images, the maximum error is reduced by up to 72 pixels for a 256 x 256 image representation compared with other existing techniques. In addition, a new boundary extraction algorithm, based on a heuristic search on the neighbourhood pixels, is employed to obtain a connected single pixel width outer boundary using two preferential sequence windows. Experimental results are also presented to justify the effectiveness of the proposed algorithm.
Algorithms↗
Follicle-stimulating hormone (FSH) induced internalization of porcine FSH receptor in cultured porcine granulosa cells and Chinese hamster ovary cells transfected with recombinant porcine FSH receptor cDNA.
In order to study the fate of human follicle-stimulating hormone (FSH) when hormone binds to its receptor, a quick biochemical method that can differentiate between the surface-bound and internalized hormone was used to determine the internalization induced by FSH in cultured both porcine granulosa cells and Chinese hamster ovary (CHO) cells expressing recombinant porcine FSH receptor. The results showed that FSH was slowly internalized, and the internalized radioactivity (acid resistant) reached a peak 10-12 h after addition of 125I-hFSH. It was suggested that FSHR do not get internalized rapidly under physiological circumstances precisely because the appropriate sequences are absent.
Animals↗
Stability of human follicle-stimulating hormone receptor mRNA in stably transfected cells.
In order to assess the impact of mRNA degradation on steady state levels of follicle-stimulating hormone receptor (FSHR) mRNA and on regulation of FSHR gene expression, the stability and half-life of FSHR mRNA were determined in transfected cells expressing recombinant FSHR. Time-dependent changes in FSHR mRNA content were determined by nuclease protection-solution hybridization assay (NPA) or by qualitative reverse transcription-competitive polymerase chain reaction (RT-PCR) in cultured hFSHR-YI cells, cell lines stably transfected with a human FSHR cDNA. FSHR mRNA content remained constant during 8 h control incubations of hFSHR-Y1 cells (NPA, 2.9 +/- 0.3 micrograms/mg RNA; RT-PCR, 2.7 +/- 0.3 micrograms/mg RNA). Actinomycin D (ActD, 5 micrograms/ml) inhibited mRNA synthesis, as assessed by incorporation of [3 H]uridine into total RNA, by 90% within 1 h in hFSHR-Y1 cells. No effect of ActD on cellular morphology or viability was observed. ActD caused a time-dependent decrease in FSHR mRNA content in hFSHR-Y1 cell lines with a lag time of 1 h. There were no significant differences in the rate of FSHR mRNA degradation between the two methods of mRNA quantification. The half-life of hFSHR mRNA was 3.6 +/- 0.2 h by NPA and 3.1 +/- 0.1 h by RT-PCR. The results indicated that degradation of mRNA was an important process in maintenance of steady state expression of the FSHR gene in cells stably expressing recombinant receptor.
Adrenal Cortex Neoplasms↗
HIV epitope-peptides in aluminum adjuvant induced high levels of epitope-specific antibodies.
Some neutralizing epitopes on HIV-1 envelope proteins were shown to induce antibodies that could effectively inhibit the infection of different HIV-1 strains in vitro. But only very low levels of antibodies to these epitopes were determined in the HIV-1 infected individuals. In this study, the aluminum (alum) adjuvant to increase the immunogenicity of the neutralizing epitopes was used. Three epitope-peptides [C-(ELDKWAG)4, C-(RILAVERYLKD-G)2 and C-(GPGRAFY)2], which contain three epitopes (ELDKWA, RILAVERYLKD, GPGRAFY) from the HIV-1 Env proteins, were synthesized and conjugated to carrier protein keyhole limpet hemocyanin (KLH). The epitope-vaccines C-(ELDKWAG)4-KLH and C-(RILAVERYLKD-G)2-KLH in alum induced high levels of epitope-specific antibodies recognizing the epitopes from epitope-peptides C-(ELDKWAG)4 and C-(RILAVERYLKD-G)2, as well as the gp41 C-domain peptides P2 [C-TSLIHSLIEESQNQQEKNEQELLELDKWA (aa 646-674)] and P1 [LQARILAVERYLKDQQL (aa 583-599)] and the recombinant soluble gp41 (rsgp41) bearing both epitopes (antibody titer in rabbit sera was 1:12800-25,600 dilution). Immunoblotting analysis demonstrated that the antibodies in both antisera bound to rsgp41, indicating that both antibodies recognized the natural epitopes on rsgp41 protein. The epitope-vaccines C-(GPGRAFY)2-KLH induced moderate GPGRAFY epitope-specific antibody response with a titer of 1:6,400. In contrast, as it was demonstrated in previous studies, the immunization with rgp160 induced weak antibody response to these three epitopes (titer of 1:400-1600). This suggests that epitope-peptides conjugated to KLH when infected with alum significantly increases immunogenicity of gp41 neutralizing epitopes providing a hope for the development of an HIV-1 vaccine.
AIDS Vaccines↗
A comparison of dietary and non-dietary factors of hypertension and normal blood pressure in a Chinese population.
The aim of this study was to compare the differences of dietary and non-dietary factors in hypertension and normal blood pressure (BP) of Chinese urban people. Two cross-sectional population surveys were carried out in Tianjin, one of the three largest cities in China. A total of 2068 subjects aged 35-64 years were selected by a random stratified cluster sampling, 367 men and 395 women were hypertensive, and 623 men and 683 women had normal BP. The diet was assessed by food weighing plus consecutive individual 3-day food records. Health status, health behaviours and anthropomentry were assessed. The whole population had a high sodium and low potassium consumption level. Hypertensive men and women had significantly higher daily dietary sodium intake (P < 0.05) and hypertensive women had higher dietary sodium-to-potassium ratio (P < 0.01) than men and women with normal BP. Age, body mass index, overweight and family history of hypertension were positively related to high BP. dietary sodium intake and dietary sodium-to-potassium ratio were positively associated with high BP. Education level in women and commuting physical activity in men were inversely associated with high BP.
Adult↗
Antigenicity and predefined specificities of the multi-epitope vaccine in candidate consisting of neutralizing epitope and mutated epitopes suggested a new way against HIV-1 mutation.
A seven-amino acid epitope GPGRAFY located inside the V3 loop on envelope protein gp120 of HIV-1 is the principal neutralizing epitope (PNE), and a subset of anti-V3 antibodies specific for this epitope show a broad range of neutralizing activity. But this epitope undergoes restricted mutation. In this study, three epitope peptides [C-(GPGRAFY)2, C-(GPGQTFY)2 and C-(GPGQAWY)2] that contain neutralizing epitope GPGRAFY and its two mutated epitope GPGQTFY and GPGQAWY, were synthesized and then conjugated to carrier protein KLH (keyhole limpet hemocyanin). the epitope-vaccines C-(GPGRAFY)2-KLH, C-(GPGQTFY)2-KLH and C-(GPGQAWY)2-KLH induced high levels of antibodies to three V3 loop peptides that contain these epitopes respectively, and the antibody response induced by each epitope-vaccine showed predefined epitope-specific. When these three epitope-peptides mixed together and conjugated to carrier protein, or conjugated to carrier protein separately and then mixed together, high levels of epitope-specific antibodies which respectively recognized these epitopes on V3 loop peptide and both mutated peptides all can be induced by both of them. In blotting assay, these epitope-specific antibodies all recognized the neutralizing epitope and mutated epitopes on peptides respectively. In addition, the reactivity of the antibodies with whole gp120 molecule which contained the epitope GPGRAFY was tested. Only the GPGRAFY-epitope-specific antibodies but not the other antibodies recognized the gp120 molecule. These results provide experimental evidence that the candidate multi-epitope-vaccine containing neutralizing epitope and mutated epitopes may bring new hope against viral mutation resulting in HIV-1 immune evasion and may be developed as an effective vaccine with a broad neutralizing activity against HIV-1 infection.
AIDS Vaccines↗
Different worlds, different tasks for health promotion: comparisons of health risk profiles in Chinese and Finnish rural people.
The aim of this study was to compare cardiovascular risk factors of working-aged people in Chinese and Finnish rural villages. The surveys were carried out in 1989 in Tianjin, China, and in Kuopio, Finland. Altogether, 897 Chinese inhabitants and 795 Finnish subjects participated in the surveys. Health behaviours were recorded, and height, weight, blood pressure, heart rate and serum lipids were measured. Generally Finns had a significantly higher mean body-mass index, systolic and diastolic blood pressures, and serum total cholesterol, low-density lipoprotein cholesterol, and total cholesterol/high-density lipoprotein ratio than the Chinese. However, no difference was seen between Chinese and Finnish women in diastolic blood pressure and serum triglycerides. Lower high-density lipoprotein cholesterol levels were observed in Finnish men than in Chinese men, whereas a higher mean level was shown in Finnish women than in Chinese women. There were significantly higher mean heart rates and prevalence of smoking in Chinese than in Finnish populations. More people who were overweight, obese and hypertensive were found in the Finnish than in the Chinese populations. Most of the Finns had two or more cardiovascular risk factors compared with the Chinese, the majority of whom were in the group with less than two risk factors. In conclusion, the risk profiles are clearly somewhat different in these two countries. A major task for the Chinese health policy and health care system is to decrease smoking and to prevent obesity and hypertension. In Finland, the biggest task seems to be the reduction of weight and lipid abnormalities, and the prevention of hypertension.
Adult↗
Capillary and microchip electrophoresis for rapid detection of known mutations by combining allele-specific DNA amplification with heteroduplex analysis.
BACKGROUND: Detection of mutations by gel electrophoresis and allele-specific amplification by PCR (AS-PCR) is not easily scaled to accommodate a large number of samples. Alternative electrophoretic formats, such as capillary electrophoresis (CE) and microchip electrophoresis, may provide powerful platforms for simple, fast, automated, and high-throughput mutation detection after allele-specific amplification. METHODS: DNA samples heterozygous for four mutations (185delAG, 5382insC, 3867G-->T, and 6174delT) in BRCA1 and BRCA2, and homozygous for one mutation (5382insC) in BRCA1 and two mutations (16delAA and 822delG) in PTEN were chosen as the model system to evaluate the capillary and microchip electrophoresis methods. To detect each mutation, three primers, of which one was labeled with the fluorescent dye 6-carboxyfluorescein and one was the allele-specific primer (mutation-specific primer), were used to amplify the DNA fragments in the range of 130-320 bp. AS-PCR was combined with heteroduplex (HD) analysis, where the DNA fragments obtained by AS-PCR were analyzed with the conditions developed for CE-based HD analysis (using a fluorocarbon-coated capillary and hydroxyethylcellulose). The CE conditions were transferred into the microchip electrophoresis format. RESULTS: Three genotypes, homozygous wild type, homozygous mutant, and heterozygous mutant, could be identified by CE-based AS-PCR-HD analysis after 10-25 min of analysis time. Using the conditions optimized with CE, we translated the AS-PCR-HD analysis mutation detection method to the microchip electrophoresis format. The detection of three heterozygous mutations (insertion, deletion, and substitution) in BRCA1 could be accomplished in 180 s or less. CONCLUSIONS: It is possible to develop a CE-based method that exploits both AS-PCR and HD analysis for detecting specific mutations. Fast separation and the capacity for automated operation create the potential for developing a powerful electrophoresis-based mutation detection system. Fabrication of multichannel microchip platforms may enable mutation detection with high throughput.
BRCA1 Protein↗
[Hypoglycemic effect of chitosan-microcapsulated insulin on the blood glucose level of streptozotocin-diabetic Wistar rats].
This study was conducted to observe the hypoglycemic effect of chitosan-microcapsulated insulin (insulin-microspheres) on blood glucose (BG), in diabetic rats by gavage. Using the scanning electron microscope, we observed the shape and distribution of insulin-microspheres in the tissues of liver, spleen, and small intestine of normal rats after gavage. The following groups of rats were studied: normal control rats (NC, n = 5); streptozotocin (STZ)-inducing diabetic control rats(DC, n = 6); STZ-diabetic rats treated with insulin-microsphere [120 u/kg] by gavage (DF, n = 6); STZ-diabetic rats treated with subcutaneous insulin injection [24 u NPH/kg] (DT, n = 6). Blood glucose was measured at 0-7 days after the treatments. The insulin-microspheres was found in small intestine, liver and spleen at 1, 2, 3 and 7 days. In DF group, the average blood glucose level decreased significantly from 24.7 +/- 3.2 mmol/L to 16.9 +/- 5.5 mmol/L during the first day of treatment and reached the lowest level (12.1 +/- 5.7 mmol/L) on the second day. From the third day on, the BG gradually elevated to the level before treatment; the maximum decrease of blood glucose level was 50.2%. In DT group, the average blood glucose level decreased from 25.2 +/- 3.8 mmol/L to 10.4 +/- 5.2 mmol/L during the first day of treatment and then went up gradually from the 2nd day on; the maximum decrease of glucose level was 58.7%. No significant difference was seen in maximum decrease between the two groups. These data demonstrate that oral chitosan-microcapsulated insulin has the antihyperglycemic effect on the blood glucose level of streptozotocin-diabetic rats.
Animals↗
Central norepinephrine pathways are involved in cardiovascular response to intracerebroventricular substance P.
AIM: To study the role of norepinephrine system in the cardiovascular response to intracerebroventricular substance P (SP) in rabbit. METHODS: SP was given intracerebroventricularly in anesthetized rabbits pretreated with the catecholaminergic neurotoxin, 6-hydroxydopamine (6-OHDA). The density and affinity of SP receptors on synaptosomal membranes of the hypothalamus and the ventral medulla of rabbits were determined by [125I]SP receptor assay. Arterial blood pressure and heart rate were recorded. RESULTS: Intracerebroventricular (icv) pretreatment of rabbits with 6-OHDA, reduced norepinephrine in the hypothalamus (by 86.7 %) and in the ventral medulla (by 77.0 %) respectively. The pressor response and tachycardia of these rabbits to icv SP (3.55 nmol . kg-1) were attenuated. The density and the affinity of SP receptors in the hypothalamus and the ventral medulla of 6-OHDA-lesioned rabbits were decreased. The Bmax (pmol . g-1 protein) of SP receptors in hypothalamus and the ventral medulla are 108 +/- 5, 35.9 +/- 2.2 in control group, and 42 +/- 18, 20 +/- 5 in 6-OHDA-lesioned rabbits, respectively. Kd (nmol . L-1) of SP receptors in the two regions are 0.015 +/- 0.004, 0.014 +/- 0.006 in control group and 0.029 +/- 0.001, 0.015 +/- 0.003 in 6-OHDA group. There is a significant difference of Bmax (P < 0.01) and Kd (P < 0.01, P < 0.05) in both regions between 6-OHDA groups and control groups. CONCLUSION: The results suggested that central norepinephrine pathways are involved in the cardiovascular response to icv SP.
Animals↗
[Expression of the human papillomavirus type 58L1 capsid protein in E.coli and preparation of the HPV58 L1 mouse antiserum].
BACKGROUND: Human papillomavirus type 58 (HPV58) has been shown to be one of the most important highly-oncogenic, risky HPV types. The present study aimed at investigating the expression of the HPV58 L1 major capsid protein by E.coli and preparation of HPV58 L1 antiserum. METHODS: The full length L1 coden region of HPV58 L1 was amplified by PCR, the cloned, sequenced. The expression vector pRSETB58 L1 was constructed to produce HPV58 L1 protein. The protein expressed was purified by SDS-PAGE, and used to immunize BALB/c mice. RESULTS: HPV58 L1 protein was expressed in E. coli, which has cross reaction with anti-HPV16 L1 antibody. The mouse anti-HPV58 L1 antibody was obtained and used to test the HPV58 L1 protein expressed in insect cell. CONCLUSIONS: HPV58 L1 major capsid protein was efficiently expressed in E. coli. The mouse anti-HPV58 L1 specific antibody was prepared, which can be used to test the HPV58 L1 protein expressed in eukaryotic cell.
Animals↗
[Influence of oral administration of realgar on contents of copper, zinc and selenium in rat tissues].
OBJECTIVE: To investigate the changes of copper, zinc and selenium levels in rat tissues after long-term oral administration of Realgar. METHODS: Rats were given Realgar with dosage of 50, 150, 450 mg.kg-1.d-1 for 5 weeks, and the concentrations of copper, zinc and selenium in different rat tissues as well as the contents of metallothionein in rat liver and kidney were determined with atomic absorption and hydride generation-atomic fluorescent technique. The total amount of copper excreted from feces and urine of each rat 5 days before the rat was killed was also measured. RESULTS: No significant changes of levels of copper, zinc and selenium in rat tissues were found after administration of low and middle dosages of Realgar. But higher dosage (450 mg.kg-1.d-1) of Realgar administration could induce a small but significant decrease of zinc concentration in hearts and a increase of copper contents in spleen and tibia, as well as twice more copper concentration of kidney. CONCLUSION: Copper deposit in kidney was the most significant change found among the trace elements levels in rat tissues, and this might be one of the mechanisms for kidney toxicity of Realgar.
Administration, Oral↗
[Study on gastric motility and its relevant factors in type 2 diabetes].
OBJECTIVE: In this study radionuclide semi-liquid gastric emptying (GE) study was adopted to test the gastric motility in 129 patients with type 2 diabetes. Further study was made to explore the relationship between gastric motility disorder of diabetes and the influential factors. METHODS: The variables to be measured and analyzed were age, BMI, duration of illness, level of glycemia, HbAlc, plasma insulin, motilin, gastrin, glucagon and Mg2+. RESULTS: Of the 129 cases, 80 had delayed GE with an occurrence of 62.02%, and there was a close correlation between gastric motility disorder and the duration of illness, BMI, FPG, PPG, serum insulin, motilin levels and HbAlc as well. CONCLUSION: These findings imply that gastric motility disorder of diabetes is influenced by multiple factors. The results also suggest that gastric motiligy disorder is much more common than expected, and radionuclide gastric emptying test is a useful aid for the early detection of this clinical entity.
Adult↗
[The abnormal changes of apolipoprotein(s) in patients with type 2 diabetes mellitus].
OBJECTIVE: To investigate the changes of the apolipoproteins(apoA I, A II, B100, C II, C III, E) in patients with type 2 diabetes mellitus. METHODS: The levels of fasting plasma glucose(FBG), insulin, TG, TC, apoA I, A II, B100, C II, C III, E were all measured in 127 non-diabetic subjects and 143 type 2 diabetic patients (20 associated with coronary heart disease (CHD) and 66 associated with hypertriglyceridemia(HTG), 55 associated with hypercholesterolemia). RESULTS: In male type 2 diabetic patients, the levels of FBG, WHR and apoC II were significantly higher (P < 0.05) and apoA I, A II levels were significantly lower (P < 0.05) than those in male non-diabetic subjects. In female type 2 diabetic patients, the levels of FBG, BMI, WHR, TG significantly elevated while HDL-C, apoA I, A II levels significantly decreased as compared with those in female non-diabetic subjects. In type 2 diabetic group, the levels of WHR, FBG and TG in HTG patients were elevated significantly as compared with those without HTG, and the levels of HDL-C, apoA I and apoA II were decreased; the levels of WHR, TG, TC, apoB100, C II, C III, E in patients with HTC were significantly higher than those whose cholesterol levels were normal. In patients with CHD, the levels of fasting insulin, apoB100, apoC II and apoE were significantly higher than those in patients without CHD, and the levels of HDL-C and apoA II were decreased significantly. CONCLUSION: Abnormal changes of apo(s) in type 2 diabetes mellitus may be a cause of type 2 diabetes associated with HTG and CHD.
Adult↗
[The mechanism of protective effects of enalapril on experimental diabetic nephropathy of rats].
OBJECTIVE: To elucidate the mechanisms of renoprotective effects of ACEI on diabetic animals and patients. METHODS: STZ-induced diabetic rats were treated with Enalapril and the levels of urine protein, TGF-beta and AGEs in renal tissue were measured and compared. RESULTS: The results of TGF-beta quantitation and AGE fluorescence of Enalapril treatment group rats were the same as those of diabetic control rats. CONCLUSION: Suppression of TGF-beta overexpression or AGEs accumulation was not implicated in the mechanisms of renoprotective effects of ACEI.
Angiotensin-Converting Enzyme Inhibitors↗
[A multicenter randomized controlled clinical trial on lipids regulating effects of domestic simvastatin].
OBJECTIVE: This clinical trial was designed to assess the lipids regulating effects of domestic simvastatin (DS, produced by Chengdu Huayu Pharmaceutical Co.) in patients with hyperlipidemia. METHODS: 160 hyperlipidemic patients were randomly divided into 3 groups (A, B and C). Groups A and B were subjected to single-blind trial; group C was for open trial. Group A took DS 10 mg q.n., group B Zocor 10 mg q.n. and group C DS 10 mg q.n. respectively for 8 weeks. All the patients were followed up at the 4th week and 8th week. 155 patients finished the trial with 59 cases in group A, 47 cases in group B and 39 cases in group C. RESULTS: At the 4th week, serum total cholesterol (TC) in group A, B and C decreased by 16.88%, 19.23% and 14.10%; serum triglycerides (TG) decreased by 19.27%, 15.66% and 17.96%; HDL-C increased by 7.69%, 7.46% and 6.69%; and LDL-C decreased by 23.02%, 27.84% and 24.43%, respectively; there was no significant difference among the three groups (P > 0.05). At the 8th week, serum TC in groups A, B and C decreased by 25.03%, 26.53% and 25.22%. TG decreased by 23.85%, 24.74% and 24.75%; HDL-C increased by 9.23%, 8.95% and 8.39%; and LDL-C decreased by 33.72%, 35.50% and 30.99%, respectively; still, no significant difference among the three groups was observed (P > 0.05). The incidence rates of side effects in the three groups were similar. The clinical effects were more significant at the 8th week than at the 4th week for Zocor and DS. CONCLUSION: These data suggest that DS is as effective and safe as Zocor in clinical use for lipids regulating serum.
Adult↗
Deletion of tyrosine hydroxylase gene reveals functional interdependence of adrenocortical and chromaffin cell system in vivo.
Catecholamines are produced in the medulla of the adrenal gland and may participate in the intraglandular regulation of its cortex. We analyzed the adrenal structure and function of albino tyrosine hydroxylase-null (TH-null) mice that are deficient in adrenal catecholamine production. Adrenal catecholamines were markedly reduced, and catecholamine histofluorescence was abrogated in 15-day-old TH-null mice. Chromaffin cell structure was strikingly altered at the ultrastructural level with a depletion of chromaffin vesicles and an increase in rough endoplasmic reticulum compared with wild-type mice. Remaining chromaffin vesicles lined up proximally to the cell membrane in preparation for exocytosis providing a "string-of-pearls" appearance. There was a 5-fold increase in the expression of proenkephalin mRNA (502.8 +/- 142% vs. 100 +/- 17.5%, P = 0.016) and a 2-fold increase in the expression of neuropeptide Y (213.4 +/- 41.2% vs. 100 +/- 59.9%, P = 0.014) in the TH-null animals as determined by quantitative TaqMan (Perkin-Elmer) PCR. Accordingly, immunofluorescence for met-enkephalin and neuropeptide tyrosine in these animals was strongly enhanced. The expression of phenylethanolamine N-methyl transferase and chromogranin B mRNA was similar in TH-null and wild-type mice. In TH-null mice, adrenocortical cells were characterized by an increase in liposomes and by tubular mitochondria with reduced internal membranes, suggesting a hypofunctional state of these steroid-producing cells. In accordance with these findings, plasma corticosterone levels were decreased. Plasma ACTH levels were not significantly different in TH-null mice. In conclusion, both the adrenomedullary and adrenocortical systems demonstrate structural and functional changes in catecholamine-deficient TH-null mice, underscoring the great importance of the functional interdependence of these systems in vivo.
Adrenal Glands↗