Biomedical subjects

Jun Dai

Publications and source records attributed to Jun Dai.

At least 37 records · Page 2Linked to original sources

PubMed2005

[Apolipoprotein B is associated with metabolic syndrome in Chinese pedigrees with familial hyperlipidemia].

OBJECTIVE: To investigate the prevalence of metabolic syndrome (MS) as well as the potential predictors in families with familial combined hyperlipidemia (FCHL), familial hypertriglyceridemia (FHTG), familial hypercholesterolemia (FH) and normolipidemic families in China. METHODS: The prevalence of MS was identified among 70 different families with 560 individuals aged > or = 20, including 43 FCHL families with 379 individuals, 3 FHTG families with 30 individuals, 16 FH families with 102 individuals and 8 normolipidemic families with 49 individuals. Diagnosis of MS was based on the modified criteria of National Cholesterol Education Program, US, substituting body mass index for waist circumference. Multivariate logistic regression was used to analyze the association between MS and different pedigrees. RESULTS: MS was identified in 60.7% of the FCHL patients and 71.4% of the FHTG patients. The prevalence of MS in the family members was 36.7% for the FCHL families, 33.3% for the FHTG families, 17.6% for the FH families, and 16.3% for the normolipidemic families, with an odds ratio (OR) of 2.97 (95% CI 1.29 to 7.07) in the FCHL families compared with in the normolipidemic families. Multivariate logistic regression showed an association between apolipoprotein (apo) B and MS with an OR of 1.05 (1.03 to 1.07) in the FCHL families, an OR of 1.26 (1.03 to 1.55) in the FHTG families, and an OR of 1.07 (1.01 to 1.12) in the FH families, independent of variables such as age, gender, apoA1, and LDL cholesterol, but showed no association in the normolipidemic families (P >0.05). Similarly, apo A1 provided an OR of 0.95 (0.94 to 0.97) in the FCHL families and an OR of 0.94 (0.90 to 0.99) in the FH families, but neither in the FHTG families nor in the normolipidemic families (both P >0.05). CONCLUSION: Apo B may be regarded as a relevant factor in the assessment of MS in FCHL, FHTG and FH families in Chinese. However, this finding needs to be verified by prospective studies in diverse ethnicities and warrants additional studies to elucidate the possible mechanisms linking apoB to MS.

Adult↗

PubMed2005

The kinase haspin is required for mitotic histone H3 Thr 3 phosphorylation and normal metaphase chromosome alignment.

Post-translational modifications of conserved N-terminal tail residues in histones regulate many aspects of chromosome activity. Thr 3 of histone H3 is highly conserved, but the significance of its phosphorylation is unclear, and the identity of the corresponding kinase unknown. Immunostaining with phospho-specific antibodies in mammalian cells reveals mitotic phosphorylation of H3 Thr 3 in prophase and its dephosphorylation during anaphase. Furthermore we find that haspin, a member of a distinctive group of protein kinases present in diverse eukaryotes, phosphorylates H3 at Thr 3 in vitro. Importantly, depletion of haspin by RNA interference reveals that this kinase is required for H3 Thr 3 phosphorylation in mitotic cells. In addition to its chromosomal association, haspin is found at the centrosomes and spindle during mitosis. Haspin RNA interference causes misalignment of metaphase chromosomes, and overexpression delays progression through early mitosis. This work reveals a new kinase involved in composing the histone code and adds haspin to the select group of kinases that integrate regulation of chromosome and spindle function during mitosis and meiosis.

Amino Acid Sequence↗

PubMed2005

Phosphorylation of ACAP1 by Akt regulates the stimulation-dependent recycling of integrin beta1 to control cell migration.

Components of intracellular signaling that mediate the stimulation-dependent recycling of integrins are being identified, but key transport effectors that are the ultimate downstream targets remain unknown. ACAP1 has been shown recently to function as a transport effector in the cargo sorting of transferrin receptor (TfR) that undergoes constitutive recycling. We now show that ACAP1 also participates in the regulated recycling of integrin beta1 to control cell migration. However, in contrast to TfR recycling, the role of ACAP1 in beta1 recycling requires its phosphorylation by Akt, which is, in turn, regulated by a canonical signaling pathway. Disrupting the activities of either ACAP1 or Akt, or their assembly with endosomal beta1, inhibits beta1 recycling and cell migration. These findings advance an understanding of how integrin recycling is achieved during cell migration, and also address a basic issue of how intracellular signaling can interface with transport to achieve regulated recycling.

ADP-Ribosylation Factor 6↗

PubMed2005

Expression, purification of human vasostatin120-180 in Escherichia coli, and its anti-angiogenic characterization.

According to codon preference of Escherichia coli, the optimized coding sequence of human vasostatin120-180aa (VAS) was obtained by chemical synthesis and molecular cloning methods. Using PCR and enzyme digestion, the full encoding sequence for VAS was cloned into the E. coli expression vector pALEX and expressed as a GST fusion protein in BL21 (DE3) strain. GST-VAS protein approximately accounted for 45% of the total bacterial proteins. Most of target protein existed in inclusion body. To improve the solubility of GST-VAS, the contribution of low temperature and molecular chaperone co-expression to the solubility of GST-VAS was tested. The results showed that co-expression with chaperons, TF and GroES/GroEL, and low expression temperature cooperatively improved the solubility of GST-VAS from 10 to 85%, and the yield of soluble GST-VAS was sixfold increased. When purified by GST affinity chromatography, 50 mg GST-VAS was obtained with purity over 85% from 1 L culture. Intact VAS was released by enterokinase digestion and further purified by Sephadex G50 gel filtration chromatography. About 7.2 mg intact homogeneous VAS protein was finally produced from 1L bacterial culture. The identity of GST-VAS and VAS was validated by Western blotting analysis. Recombinant VAS protein displayed distinct inhibition of endothelial cell proliferation and anti-angiogenic activity by chick embryo chorioallantoic membrane assay.

Angiogenesis Inhibitors↗

PubMed2005

Analysis of clinical characteristics of dyspeptic symptoms in Shanghai patients.

OBJECTIVE: To improve the management of dyspepsia by analyzing the clinical characteristics of dyspeptic symptoms in patients from Shanghai. METHODS: 782 patients with functional dyspepsia (FD) or organic dyspepsia (OD) completed a questionnaire about dyspepsia. The questionnaire asked participants to score 12 previously validated common upper abdominal symptoms. The clinical characteristics of dyspepsia including severe symptoms; and the relationship between symptoms and meals were then analyzed. RESULTS: Among the 782 dyspeptic patients, 543 cases (69.4%) were classed as FD and 239 (30.6%) OD. The proportion of males was significantly higher in the OD group. There was no difference in average dyspepsia scores between the 2 dyspeptic groups (21.5 vs 20.4, P > 0.05), but the scores of 'stomach' pain and 'stomach' pain before meals were higher in OD patients than in FD patients (2.65 +/- 1.11 vs 2.16 +/- 0.92, 2.26 +/- 1.26 vs 1.79 +/- 0.92, P < 0.05). In 45.2% of the OD patients and 47.7% of the FD patients, respectively, the severity of symptoms was not related to meals. In subgroups of ulcer-like, dysmotility-like and unspecified dyspepsia, the proportion of patients with symptoms not related to meals was 59.6%, 50.9% and 35.2%, respectively. 2.5% (6/239) of OD patients presented with progressive dysphagia, compared with 2.8% (15/543) of FD patients who presented with intermittent dysphagia. Approximately 8.8% (21/239) of OD patients reported dramatic weight loss accompanied with other severe symptoms, compared with 5.9% (32/543) of FD patients who had no other severe symptoms. A shift in symptom subtypes during the follow-up period was found in 13.8% of FD patients. The infection rate of Helicobacter pylori was higher in the OD group than in the FD group (53.1%vs 42.2%, P < 0.01), but no difference was found among the three subgroups of FD patients (P > 0.05). Halitosis was more often found in dyspeptic patients with H. pylori infection (44.9%vs 17.0% in OD, 47.3%vs 25.4% in FD, P < 0.01). CONCLUSIONS: When dyspepsia patients present with 'stomach' pain or 'stomach' pain before meals, a diagnosis of OD should be considered. Intermittent dysphagia, weight loss not accompanied with other severe symptoms, and halitosis (more often seen in patients with H. pylori infection) might be regarded as the relatively unique symptoms of dyspepsia in some FD patients. In FD, we found that the severity of dyspepsia symptoms was not related to meals in half of the patients, and symptom subtypes might shift over time, this adds difficulty to the management of FD.

China↗

PubMed2005

[Coronary angiography by transradial approach with 5F universal catheter].

OBJECTIVE: To probe the efficacy and feasibility of the transradial approach for diagnostic coronary angiography with 5F universal catheter. METHODS: Transradial coronary angiography was performed in 3094 consecutive patients, 2396 men and 698 women, aged 30 - 81 years, mean age (56.1 +/- 9.8) years, from July 2000 to April 2004. Patients were divided into 5F improved Terumo catheter group (improved Terumo group, n = 985), 5F universal Terumo catheter group (Terumo group, n = 1024) and 5F universal Medtronic catheter group (Medtronic group, n = 1085). The procedure success rate, duration of operation and fluoroscopy between groups were compared. RESULTS: The procedure success rate was 98.4% in improved Terumo group, 98.0% in Terumo group, and 96.0 % in Medtronic group, respectively. The success rate was higher in improved Terumo group than in Medtronic group (P < 0.05). The average duration of operation and fluoroscopy in improved Terumo group was (17.9 +/- 5.8) min and (4.8 +/- 1.8) min, in Terumo group was (18.2 +/- 5.5) min and (5.0 +/- 1.7) min, but (21.1 +/- 7.2) min and (5.2 +/- 1.9) min in Medtronic group. There were significant differences among group (P < 0.05). CONCLUSIONS: (1) Transradial coronary angiography with small diameter universal catheter is safe and easy to perform with a higher success rate and allow earlier patient ambulation, and should be strongly encouraged and recommended. (2) Option of angiographic catheter plays a key role in the safety, efficacy and quality of transradial coronary angiography. Seemingly, the improved Terumo group was excellent and shoud be popularized.

Adult↗

PubMed2005

[The influence of diabetes mellitus on the procedural and in-hospital outcomes after selective percutaneous coronary intervention].

OBJECTIVE: To compare the procedural and in-hospital outcomes in a large series of diabetic and non-diabetic patients undergoing selective percutaneous coronary intervention (PCI) and to evaluate the influence of diabetes mellitus on the procedural and in-hospital outcomes. METHODS: 1294 consecutive patients underwent selective PCI from January to December 2002 in this institution were analyzed retrospectively. Baseline clinical, in-lab and in-hospital outcome information were recorded. Rates of procedural success, device success and clinical success were analyzed and logistic regression was performed to model the association between diabetes status and outcomes. RESULTS: Two hundred and sixty-nine patients (20.8%) complicated with diabetes. Type C lesion, double and triple vessel diseases were more prevalent in diabetics than those in non-diabetics. The pre-PCI diameter stenosis of diabetics was significantly more severe than that of non-diabetics (91.00 +/- 6.62 vs 89.81 +/- 6.64, P < 0.01). The balloon length, maximum balloon diameter and maximum balloon inflation pressure, maximum inflation duration were larger in diabetics than those in non-diabetics [(17.07 +/- 6.31) mm vs (16.07 +/- 7.28) mm, (2.30 +/- 1.11) mm vs (2.12 +/- 0.94) mm, (9.86 +/- 4.40) atm vs (9.05 +/- 4.75) atm, (20.94 +/- 14.69) s vs (18.26 +/- 14.65) s, respectively, P < 0.05]. The stent diameter was smaller in diabetics than that in non-diabetics [(3.15 +/- 0.47) mm vs (3.23 +/- 0.43) mm, P < 0.05]. The procedural success rate showed no significant difference between two groups (89.6% vs 90.3%, P > 0.05). But a higher incidence of acute/subacute stent thrombosis was observed in diabetics compared with that in non-diabetics (1.9% vs 0.5%, P < 0.05). The rate of clinical success was similar between diabetics and non-diabetics (99.3% vs 99.2%, P > 0.05). Diabetes was not an independent predictor of acute outcomes in the regression model. CONCLUSIONS: A higher incidence of acute/subacute stent thrombosis was observed in diabetics. The incidence of procedural and in-hospital major adverse cardiac events and the rate of clinical success were similar between diabetics and non-diabetics. Diabetes was not an independent predictor of in-hospital outcomes after selective PCI.

Aged↗

PubMed2005

[Formation mechanism of Sr2CeO4 and its effect on spectral properties].

The phase composition of SrCO3 and CeO2 (2:1) powder mixture calcined at different temperatures was identified by X-ray diffraction method. It was found that there were two types of formation mechanism of Sr2CeO4. When the starting powder mixture was fired above 1000 degrees C, the unstable intermediate phase SrCeO3 developed, which then reacted with SrCO3 to form the final product Sr2CeO4, however when the sintering temperature was lower, SrCO3 and CeO2 were converted directly to Sr2CeO4. The excitation spectra of Sr2CeO4 were quite different for different formation mechanism. The strong excitation band presented maxima at about 280 nm for the samples formed by the former mechanism, while the maxima were at about 254 nm for the samples formed by the latter mechanism. The formation mechanism had no effect on the emission spectra.

Cerium↗

PubMed2004

ACAP1 promotes endocytic recycling by recognizing recycling sorting signals.

Cargo sorting that promotes the transport of cargo proteins from a membrane compartment has been predicted to be unlikely in the endocytic recycling pathways. We now show that ACAP1 binds specifically and directly to recycling cargo proteins. Reducing this interaction for TfR inhibits its recycling. Moreover, ACAP1 binds to two distinct phenylalanine-based sequences in the cytoplasmic domain of TfR that function as recycling sorting signals to promote its transport from the recycling endosome. Taken together, these findings indicate that ACAP1 promotes cargo sorting by recognizing recycling sorting signals.

ADP-Ribosylation Factor 6↗

PubMed2004

[Investigation on the alteration of hepatitis B virus (HBV) markers in liver allograft of HBV related recipients in perioperative period].

OBJECTIVE: To investigate the alteration of HBV markers in liver allograft of HBV related recipients pre and post liver transplantation under Lamivudine or combination of Lamivudine with HBIG prophylaxis and explore the mechanism of HBV de nova infection in liver allograft after orthotopic liver transplantation, as well as seek to establish a optimal prophylactic protocol. METHODS: The serial liver biopsy specimens of 90 liver allograft and sera of 78 liver transplant recipients during operation and after 1 week, 1 month, 3 months, 6 months, 12 months, 24 months post transplantation have been collected and detected for HBV markers with enzyme-linked radioimmunoassay, fluorescent quantitative assay for HBV-DNA in serology and with immunohistochemistry stain, HBV-DNA in situ hybridization in histology for detection of HBV markers in liver allograft samples. RESULTS: Whether recipients with active replicative or inactive replicative HBV preoperatively, none of positive HBV-DNA, HBsAg and HBcAg in 100% liver biopsy specimens with HBV-DNA hybridization in situ and immunohistochemistry stains in histology within 2 hours after reperfusion. CONCLUSION: Whatever HBV replicative status the recipients have before surgery, no evidence of HBV particles direct invasion to the liver allograft from HBV related cirrhotics during operation under current prophylactic measures. However, the further supposed mechanism and its significance in HBV de nova infection of liver allograft remained to be disclosed further.

Adolescent↗

PubMed2004

[Simulated moving bed technology and its applications].

Simulated moving bed (SMB) chromatography is a modernized separation technology. The history of its development and principle operation are introduced in details. The major applications of SMB chromatography are also reviewed.

Chromatography↗

PubMed2003

Comparison of the chromatography of octadecyl silane bonded silica and polybutadiene-coated zirconia phases based on a diverse set of cationic drugs.

In this study, we compare the separation of basic drugs on several octadecyl silane bonded silica (ODS) phases and a polybutadiene-coated zirconia (PBD-ZrO2) phase. The retention characteristics were investigated in detail using a variety of cationic drugs as probe solutes. The ODS phases were selected to cover a relatively wide range in silanol activity and were studied with ammonium phosphate eluents at pH 3.0 and 6.0. Compared to any of the ODS phases, the PBD-ZrO2 phase showed very significant differences in selectivities towards these drugs. Due to the presence of both reversed-phase and ion-exchange interactions between the stationary phase and the basic analyte on ODS and PBD-ZrO2, mixed-mode retention takes place to some extent on both types of phases. However, very large differences in the relative contributions from ion-exchange and reversed-phase interactions on the two types of phases led to quite different selectivities. When phosphate is present in the eluent and adsorbs on the surface, the PBD-ZrO2 phase takes on a high negative charge over a wide pH range due to phosphate adsorption on its surface. On ODS phases, ion-exchange interactions result from the interactions between protonated basic compounds and ionized residual silanol groups. Since the pH of the eluent influences the charge state of the silanol groups, the ion-exchange interactions vary in strength depending on pH. At pH 6.0, the ion-exchange interactions are strong. However, at pH 3.0 the ion-exchange interactions on ODS are significantly smaller because the silanol groups are less dissociated at the lower pH. Thus, not only are the selectivities of the ODS and PBD-ZrO2 phases different but quite different trends in retention are observed on these two types of phases as the pH of the eluent is varied. More importantly, by using the large set of "real" basic analytes we show the extreme complexity of the chromatographic processes on the reversed stationary phases. Both the test condition and solute property influence the column performance. Therefore, use of only one or two probe solutes is not sufficient for column ranking.

Butadienes↗

PubMed2003

Effect of amine counterion type on the retention of basic compounds on octadecyl silane bonded silica-based and polybutadiene-coated zirconia phases.

In a previous paper, we compared the mixed-mode retention characteristics of cationic solutes on octadecyl silane-bonded silica (ODS) and polybutadiene-coated zirconia (PBD-ZrO2) phases. It is well recognized that both reversed-phase and ion-exchange interactions contribute to the retention of cations on ODS phases. The reversed-phase interaction results from the bonded hydrocarbon chain; the ion-exchange interaction originates in the ionized residual silanol groups. These two types of interactions also exist on the PBD-ZrO2 phase. The polybutadiene contributes to the reversed-phase interaction and the ionized zirconol, but primarily, the adsorbed Lewis base anions, such as phosphate or fluoride, contribute to the ion-exchange interaction. We have shown that on ODS phases, reversed-phase interactions are much more important, whereas the opposite is true of PBD-ZrO2 phases. In this work, we investigate the effect of several amine mobile phase counterions on the retention of cationic solutes on ODS and PBD-ZrO2 phases. The effects of the chain length and the type of amine (1 degree, 2 degrees, 3 degrees) counterion on the retention of basic compounds were studied. In contrast to older studies of type A silica-based phases, the results show that the chain length and type of the amine blocker do not have a large effect on the retention of basic compounds with the newer type B silica-based materials. However, on the PBD-ZrO2 phase, very striking differences in retention were observed with different amine counterions. We show that the molecular geometry of the amine counterion has a significant effect on the retention of basic solutes on the PBD-ZrO2 phase.

Amines↗

PubMed2003

Analysis and critical comparison of the reversed-phase and ion-exchange contributions to retention on polybutadiene coated zirconia and octadecyl silane bonded silica phases.

The two major modes of retention of basic compounds in reversed-phase liquid chromatography on both octadecyl silane bonded silica-based (ODS) and polybutadiene coated zirconia (PBD-ZrO2) materials are hydrophobic and ion-exchange (Coulombic) interactions. Although the influence of reversed-phase and Coulombic interactions on the chromatography of organic cations is qualitatively well recognized, the quantitative relationship between hydrophobic and ion-exchange interactions remains unclear. In this work, the retention mechanisms on both of the above types of phases were probed by studying the retention of a homologous series of p-alkylbenzylamines as a function of the ammonium concentration in the eluent. The various columns tested were studied in terms of plots of retention factor vs. the inverse of the displacingcation concentration. The analysis of such plots as well as plots of log k' vs. number of methylene groups in the solutes and plots of log k' vs. log[NH4+] clearly shows that at least two types of sites--a pure reversed-phase site and a "hydrophobically-assisted ion-exchange site" similar to the type of site described by Neue [J. Chromatogr. A 925 (2001) 49] are needed to explain the observations. In addition, we have found a quantitative measure of the relative amount of reversed-phase and ion-exchange interaction on a given solute has on a given stationary phase which allows unambiguous classification of columns. It is now clear that ion-exchange contributions to retention on PBD-ZrO2, sometimes exceeding 90%, are even more important than previously thought and relative to hydrophobic interaction much more significant on PBD-ZrO2 than on ODS type-B silicas.

Buffers↗

PubMed2002

MT(1) melatonin receptor overexpression enhances the growth suppressive effect of melatonin in human breast cancer cells.

Melatonin inhibits the proliferation of estrogen receptor alpha (ERalpha)-positive (MCF-7), but not ERalpha-negative (MDA-MB-231) breast cancer cells. Here, we assessed the effect of MT(1) melatonin receptor stable overexpression in MCF-7 and MDA-MB-231 breast cancer cells on the growth-suppressive effects of melatonin. Parental and vector-transfected MCF-7 cells demonstrated a modest, but significant, growth-suppressive response to melatonin; however, melatonin treatment of MT(1)-transfected MCF-7 cells resulted in significantly enhanced growth-suppression. This response was blocked by an MT1/MT2 melatonin receptor antagonist. Interestingly, MT(1)-overexpression did not induce a melatonin-sensitive phenotype in melatonin-insensitive MDA-MB-231 cells. Finally, Northern blot analysis demonstrated an enhanced inhibition of ERalpha mRNA expression and an enhanced induction of pancreatic spasmolytic polypeptide (pS2) by melatonin in MT(1)-transfected MCF-7 cells relative to vector-transfected MCF-7 cells. These data suggest the involvement of the MT(1) melatonin receptor in mediation of melatonin effects on growth-suppression and gene-modulation in breast cancer cells.

Adenocarcinoma↗

PubMed2002

Modulation of intracellular calcium and calmodulin by melatonin in MCF-7 human breast cancer cells.

The pineal hormone, melatonin, has been shown to inhibit the proliferation of the estrogen receptor alpha (ERalpha)-positive macrophage chemotactic factor (MCF)-7 human breast cancer cells. Previous studies from other systems indicate that melatonin modulates the calcium (Ca2+)/calmodulin (CaM) signaling pathway either by changing intracellular calcium concentration ([Ca2+]i) via activation of its G-protein coupled membrane receptors, or through a direct interaction with CaM. In this study, although melatonin alone had no effect on basal [Ca2+]i in MCF-7 cells, it significantly enhanced the elevation of [Ca2+]i induction by extracellular adenosine triphosphate (ATP), which increases [Ca2+]i via the G protein-coupled P2y-purinoceptor and the phospholipase C (PLC) pathway. Pretreatment of MCF-7 cells with 10(-7) M melatonin increased the 10(-5) M ATP-induced [Ca2+]i peak change from 79.4 +/- 11.6 nM to 146.2 +/- 22.3 nM. Furthermore, without changing total cellular CaM levels, melatonin markedly increased the amount of membrane-bound CaM to 237 and 162% of control levels after I and 6 hr of treatment, respectively. Cytosolic CaM levels were also elevated to 172% of control after 6 hr of melatonin treatment. Correlative growth studies demonstrated that ATP (10(-5) M) can stimulate MCF-7 cell growth, that melatonin can suppress MCF-7 cell proliferation, but that pretreatment of MCF-7 cells with melatonin followed by ATP(10(-5) M), like 10(-4) M ATP can further suppress MCF-7 cell proliferation; this indicates that melatonin's potentiation of ATP induced [Ca2+]i may be above the threshold for cell growth. Given the important role of [Ca2+]i and CaM in tumor cell homeostasis and proliferation and melatonin's modulation of [Ca2+]i, melatonin's effects on the Ca2+/CaM signaling pathway may play an important role in mediating the growth-inhibitory effect of melatonin on MCF-7 human breast cancer cells.

Adenosine Triphosphate↗

PubMed2002

Development of cellulose-DNA immunoadsorbent.

The aim of this study was to prepare a DNA immunoadsorbent for the specific, extracorporeal removal of anti-DNA antibodies from the blood of patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Two kinds of cellulose beads were applied as a carrier. Calf thymus DNA was covalently coupled to the carrier using the epichlorohydrin method. Efforts were focused on optimization of conditions for activation and coupling, trying to couple as much DNA as possible to a certain amount of carrier. It was found that the activation level increased with the increase of NaOH concentration and the amount of epichlorohydrin used. The mole of epichlorohydrin must be in excess of that of NaOH because excess NaOH could react further with the epoxy groups in the beads resulting in a decrease of activation level. High activation level could be obtained in a medium of 3.0 M NaOH. The DNA coupling was found to be mainly temperature and pH dependent. Using 0.1 M Tris-HCl buffer, pH 8 at a temperature of 50-90 degrees C, more than 3 mg of DNA could be coupled to 1 ml of wet beads. Prolonging the coupling reaction under 50 degrees C to 72 h resulted in the same coupling capacity as that obtained under 90 degrees C. To evaluate the adsorption ability for anti-DNA of this immunoadsorbent, batch and circulation tests were applied using SLE patient plasma. The immunoadsorbents showed excellent adsorption capacity, especially the cellulose with smaller size (200-300 microm). The incubation of 20 ml of patient's plasma with 1 ml of adsorbent resulted in an 80% decline in the anti-DNA antibody level. In the circulation tests, 30 ml of plasma was circulated through a column containing 3 ml of adsorbent. The maximum decline in anti-DNA level, 80%, was obtained after 60 min. Such high adsorption capacity and high adsorption rate suggest this immunoadsorbent may be used for treatment. For comparison, 1,4-butanediol diglycidyl ether activation method and other DNA sources were tested with the same protocol.

Adsorption↗

PubMed2002

Detection of apoptotic alterations in sperm in subfertile patients and their correlations with sperm quality.

BACKGROUND: The aim of the present study was to define the effect of apoptosis on sperm quality and function. METHODS: The apoptotic features in sperm were assessed in 60 subfertile subjects, using Annexin-V staining for phosphatidylserine (PS) externalization and Tdt-mediated dUTP nick end labelling (TUNEL) assay for DNA fragmentation. RESULTS: On average, about 45% of the sperm were found to be apoptotic based on the results from Annexin-V staining, including both early (Annexin-V-positive, PI-negative) and late apoptosis (Annexin-V-positive, PI-positive). TUNEL-positive cells (median value 15%) significantly correlated to late apoptosis but not early apoptosis, indicating that DNA fragmentation only occurs at the later stage of sperm apoptosis. TUNEL-positive and late apoptotic cells (Annexin-V-positive, PI-positive) were found to be inversely correlated to sperm motility and vitality, and positively to abnormal sperm morphology. On the other hand, it is surprising to note that the apoptotic alterations in sperm positively correlated to sperm concentration or total sperm counts. CONCLUSIONS: Overall results from this study support the abortive apoptosis theory; apoptosis in mature sperm is initiated during spermatogenesis, after which some cells earmarked for elimination via apoptosis may escape the removal mechanism and contribute to poor sperm quality.

Adult↗