Interaction of monocytes with tumor cells coated with complement with or without antibody

Raji, a human B lymphoblastoid cell line has the ability to activate the complement cascade by alternate pathway mechanisms with subsequent fixation of C3 to receptors on the Raji cell membrane. Using this property, we examined the role that complement plays in mediating a cytolytic event between human peripheral blood monocytes and Raji cells coated with C3b, antibody, or both. Presence of C3 was confirmed by immune adherence. IgG bound to the Raji membrane was quantitated using I¹²⁵ Staphylococcal protein A assay. The presence of alternate pathway-activated C3 on Raji cells failed to produce monocyte-mediated cytotoxicity. These same target cells subsequently coated with antibody concentration ranging from 200 to >600,000 SPA molecules per Raji cell produced neither enhancement nor inhibition of antibody-dependent, cell-mediated cytotoxicity (ADCC). ADCC was enhanced by complement when complement activation and binding of C3 to the cell surface occurred by classical pathway mechanisms. ADCC of 32% ± 3.2 occurred with undiluted antiserum (625,000 SPA molecules bound/Raji cell) with enhancement to 52% ± 1.1 in the presence of C3. IgG inhibition of ADCC was unaffected by the presence of membrane-bound C3.     

Staining with Fluorescein Diacetate Correlates with Hepatocyte Function

To establish the importance of fluorescein diacetate (FDA) as a viability stain for cultured hepatocytes. we hypothesized that FDA staining would correlate positively with hepatocyte viability and function. Mixtures of live and dead cells were stained with FDA and scanned by flow cytometry. A close correlation was observed between the live cell fraction and percent viability as determined by FDA staining (R² = 0.962). Hepatocytes were also sorted into low fluorescence and high fluorescence groups. Both albumin production and lidocaine metabolism (P-450 activity) were significantly increased in the high fluorescence group compared to the low fluorescence group. An automated, fluorescence-activated assay was useful for rapid assessment of hepatocyte viability. In addition. the intensity of green fluorescence following staining with FDA correlated well with two specific measures of hepatocyte function.     

Schoolchildren cooperate more successfully with non-kin than with siblings

Cooperation plays a key role in the development of advanced societies and can be stabilized through shared genes (kinship) or reciprocation. In humans, cooperation among kin occurs more readily than cooperation among non-kin. In many organisms, cooperation can shift with age (e.g. helpers at the nest); however, little is known about developmental shifts between kin and non-kin cooperation in humans. Using a cooperative game, we show that 3- to 10-year-old French schoolchildren cooperated less successfully with siblings than with non-kin children, whether or not non-kin partners were friends. Furthermore, children with larger social networks cooperated better and the perception of friendship among non-friends improved after cooperating. These results contrast with the well-established preference for kin cooperation among adults and indicate that non-kin cooperation in humans might serve to forge and extend non-kin social relationships during middle childhood and create opportunities for future collaboration beyond kin. Our results suggest that the current view of cooperation in humans may only apply to adults and that future studies should focus on how and why cooperation with different classes of partners might change during development in humans across cultures as well as other long-lived organisms.     

Chronic pretreatment with methylphenidate induces cross-sensitization with amphetamine

Consequence of the long-term use of psychostimulants as treatment for attention deficit/hyperactivity disorder (ADHD) is unknown, particularly whether treatment with psychostimulants at an early age increases an individual's potential for cross-sensitization to other stimulants exposed at a later age. Cross-sensitization occurs when pretreatment with one stimulant leads to greater sensitivity to another stimulant. The aims of this study were to investigate whether chronic treatment with methylphenidate (MPD; Ritalin) in both juvenile and adult rats induced cross-sensitization to amphetamine at a later time and whether this cross-sensitization to amphetamine was age-dependent. Male Sprague-Dawley rats were randomly divided into four treatment groups: (1) group treated intraperitoneally (i.p.) with saline as juveniles and adults, (2) group treated with 0.6 mg/kg amphetamine, i.p., as juveniles and adults, (3) group treated with 2.5 mg/kg MPD, i.p., as juveniles and adults, and (4) group treated with saline, i.p., as juveniles and 2.5 mg/kg MPD, i.p., as adults. All of the animals received an amphetamine (0.6 mg/kg, i.p.) challenge on the last experimental day. We examined the effects of chronic MPD treatment in juvenile and adult rats on their locomotor response to an acute amphetamine exposure. Three different locomotor indices were studied using an automated activity monitoring system. Changes in the locomotor responses to amphetamine of these animals were compared to those of control rats that were pretreated with saline as juveniles and as adults. It was found that prior chronic treatment with MPD produced cross-sensitization to the locomotor response to amphetamine as observed in the horizontal activity and total distance traveled. It also appears that this cross-sensitization to amphetamine may not be dependent on the age of the subjects, i.e., whether subjects were juvenile or adult rats when they received drugs, but rather it depended on the behavioral index examined.     

Immunosuppression with cyclophosphamide favors reinfection with recombinant Toxoplasma gondii strains

The aim of this study was to verify the effect of immunosuppression by cyclophosphamide (Cy) on susceptibility of BALB/c mice subjected to challenge with recombinant strains of Toxoplasma gondii. Animals were prime infected with the D8 (recombinant I/III) or the ME49 (type II) non-virulent strains, weekly immunosuppressed with Cy and challenged with the CH3 or EGS virulent strains (I/III). Parasites recovered from surviving mice were submitted to PCR-RFLP analysis to confirm co-infection. Prime-infection with the D8 strain conferred more protection against challenge with the CH3 and EGS strains when compared with ME49 prime infection. Cy treatment caused significant leukopenia in the infected mice, what probably favors reinfection after challenge. Reinfection was associated with increased levels of IgA. Otherwise, Cy-treated mice presented significantly lower IgA levels after challenge, suggesting involvement of this immunoglobulin on protection against reinfection. In conclusion, BALB/c mice susceptibility to reinfection by T. gondii is related to genetic differences among the strains used for primary and challenge infections. Alteration of the host's immune integrity by Cy probably compromises the protection previously established by primary infection.     

Hemorrhagic fever with renal syndrome associated with acute pancreatitis

Hemorrhagic fever with renal syndrome (HFRS) is a systemic infectious disease caused by Hantaviruses and characterized by fevers,bleeding tendencies,gastrointestinal symptoms and renal failure.It encom...     

Interactions of retinol with binding proteins: studies with retinol-binding protein and with transthyretin.

The interactions within the molecular complex in which retinol circulates in blood were studied. To monitor binding between retinol-binding protein (RBP) and transthyretin (TTR), TTR was labeled with a long-lived fluorescence probe (pyrene). Changes in the rotational volume of TTR following its association with RBP were monitored by fluorescence anisotropy of the probe. Titration of TTR with holo-RBP revealed the presence of 1.5 binding sites characterized by a dissociation constant Kd = 0.07 microM. At 0.15 M NaCl, binding of RBP to TTR showed an absolute requirement for the native ligand, retinol. At higher ionic strength (0.5 M NaCl), RBP complexed with retinal also bound to TTR with high affinity (Kd = 0.134 microM). RBP containing retinoic acid did not bind to TTR even at the high salt concentration. The data suggest that the TTR binding site on RBP is in close proximity to the retinoid binding site and that the head group of retinoic acid, when bound to RBP, presents steric hindrance for the interactions with TTR. The implications of the data for selectivity in retinoid transport in the circulation are discussed. The kinetics of the steps leading to complete dissociation of the retinol-RBP-TTR complex was also studied. The first step of this process was dissociation of retinol, which had a rate constant of 0.06/min. Following loss of retinol, the two proteins dissociate. The rate of dissociation is slow (k = 0.055/h), however, indicating that the complex apo-RBP-TTR will be an important factor in regulating serum levels of retinol.     

价格随供求变化的捕获问题

本文对开放式渔场建立了价格随供求而变化的捕获模型,对模型进行了详细的分析,并从生态学和经济学的角度对结果作了解释。为生物资源的实际管理提供了理论依据。     

A population pharmacokinetic model with time-dependent covariates measured with errors

We propose a population pharmacokinetic (PK) model with time-dependent covariates measured with errors. This model is used to model S-oxybutynin's kinetics following an oral administration of Ditropan, and allows the distribution rate to depend on time-dependent covariates blood pressure and heart rate, which are measured with errors. We propose two two-step estimation methods: the second-order two-step method with numerical solutions of differential equations (2orderND), and the second-order two-step method with closed form approximate solutions of differential equations (2orderAD). The proposed methods are computationally easy and require fitting a linear mixed model at the first step and a nonlinear mixed model at the second step. We apply the proposed methods to the analysis of the Ditropan data, and evaluate their performance using a simulation study. Our results show that the 2orderND method performs well, while the 2orderAD method can yield PK parameter estimators that are subject to considerable biases.     

Identification of biomarkers correlated with hypertrophic cardiomyopathy with co-expression analysis

Hypertrophic cardiomyopathy (HCM) is reported to be the most common genetic heart disease. To identify key module and candidate biomarkers correlated with clinical prognosis of patients with HCM, we carried out this study with co-expression analysis. To construct a co-expression network of hub genes correlated with HCM, the Weighted Gene Co-expression Network Analysis (WGCNA) was performed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed by Database for Annotation, Visualization and Integrated Discovery (DAVID). The protein-protein interaction network analysis of central genes was performed to recognize the interactions of central genes. Gene set enrichment analyses were carried out to discover the possible mechanisms involved in the pathways promoted by hub genes. To validate the hub genes, quantitative real-time polymerase chain reaction (RT-PCR) was performed. Based on the results of topological overlap measure based clustering, 2,351 differentially expressed genes (DEGs) were identified. Those genes were included in six different modules. Of these modules, the yellow and the blue modules showed a pivotal correlation with HCM. DEGs were enriched in immune system procedure associated GO terms and KEGG pathways. We identified nine hub genes (TYROBP, STAT3, CSF1R, ITGAM, SYK, ITGB2, LILRB2, LYN, and HCK) affected the immune system significantly. Among the genes we validated with RT-PCR, TYROBP, CSF1R, and SYK showed significant increasing expression levels in model HCM rats. In conclusion, we identified two modules and nine hub genes, which were prominently associated with HCM. We found that immune system may play a crucial role in the HCM. Accordingly, those genes and pathways might become therapeutic targets with clinical usefulness in the future.     

Effect of Pretreatment with Carbimazole in Patients with Thyrotoxicosis Subsequently Treated with Radioactive Iodine

Preliminary treatment with carbimazole in a series of 181 patients with thyrotoxicosis selected for treatment with radioactive iodine did not make any significant difference to the subsequent response to ¹³¹I therapy.     

Identification and Characterization of Gangliosides Reacting with IgM Paraproteins in Three Patients with Neuropathy Associated with Biclonal Gammopathy

IgM monoclonal antibodies from three patients with polyneuropathy associated with biclonal gammopathy reacted with monosialoganglioside GM1 on thin-layer chromatograms. An IgM paraprotein in one of the patients with a predominantly motor neuropathy also reacted strongly with the ganglioside GD1b and asialo-GM1. All three of these antigenic lipids have a Gal(beta 1-3)GalNAc moiety in common which would appear to be the antigenic determinant. However, this IgM also cross-reacted weakly with paragloboside which has an N-acetyllactosaminyl [Gal(beta 1-4)GlcNAc] terminal structure. The specificity of the other paraprotein in this patient is not known. The IgM paraproteins reacting with GM1 in both of the other patients exhibited different specificity because they did not react with GD1b and asialo-GM1, but reacted strongly with GM2 ganglioside. The data suggest that the epitope for both of these IgMs is in the GalNAc(beta 1-4)(NeuAc alpha 2-3)Gal(beta 1-4)Glc region of the gangliosides that is common to both GM2 and GM1. The second IgM paraproteins in both of these latter patients react with the myelin-associated glycoprotein (MAG) and two 3-sulfoglucuronyl glycolipids that share antigenic determinants with MAG.     

Testicular morphometry of rats with Walker 256 tumor supplemented with L-glutamine

Glutamine is often used to treat metabolic changes associated with anorexia-cachexia syndrome in patients with malignant neoplasms. Walker 256 tumor is an excellent model for studying these changes associated with cancer in different organs, including injuries in testicular functions. However, the effects of supplementing glutamine on testicular morphometry in this model have not yet been investigated. Thus, the objective of this study was to evaluate the effect of L-glutamine supplementation on testicular morphometry in rats transplanted with Walker 256 tumor cells. Forty puberty Wistar rats were divided into four groups: control without L-glutamine (C); control supplemented with L-glutamine (CG); inoculated with Walker 256 tumor cells (WT) and inoculated with Walker 256 tumor cells and supplemented with L-glutamine (WTG). The testicles were removed, weighed, fixed in Bouin, and included in paraffin for histomorphometric analysis. Walker 256 tumor caused quantitative changes in the tubular and intertubular compartments and tunica albuginea, with reductions in the percentages of lumen and tunica albuginea, number of Sertoli cells per gram of testis; number of Leydig cells; percentage of blood vessels and connective tissue in intertubule. However, glutamine supplementation prevented part of these changes caused by the tumor, presenting mainly a protective effect on the tunica albuginea and percentage of blood and lymph vessels in the intertubule. These results indicate the potential of L-glutamine was able to recover for testicular dysfunction associated with cancer.     

Circulating factor with ouabain-like immunoreactivity in patients with primary aldosteronism

Circulating factor with ouabain-like immunoreactivity was studied in patients with primary aldosteronism. Anti-ouabain antibody was prepared from specific pathogen-free rabbits. In the plasma of patients with primary aldosteronism, the level of a factor with ouabain-like immunoreactivity was 2.59 +/- 1.39 pmol ouabain equivalent/ml plasma. This value was significantly (p less than 0.05) higher than that of age-matched normotensive subjects, 1.06 +/- 0.86 pmol ouabain equivalent/ml plasma. The plasma level of ouabain-like immunoreactivity correlated significantly (p less than 0.05) with blood pressure. These results indicate that the factor with ouabain-like immunoreactivity may play a pathophysiological role in the maintenance of the high blood pressure observed in patients with primary aldosteronism.     

Nitric oxide levels in patients with psoriasis treated with methotrexate

Psoriasis is a chronic, recurrent, inflammatory, and hyperproliferative disease. Recently there have been studies regarding increases in the levels of NO in inflammatory dermatoses including psoriasis. In this study, 22 patients with psoriasis were scored with PASI (psoriasis area and severity index) and the levels of serum nitrite-nitrate were evaluated before and after therapy with methotrexate (Mtx). The results were compared with age- and sex-matched healthy volunteers. The relation of the results with the clinical severity and the cumulative Mtx dose were also evaluated. The serum levels of nitrite-nitrate of the psoriatic patients with active lesions were found to be significantly higher than the levels of the healthy volunteers and the patients after therapy. The elevated nitrite-nitrate serum levels in the inflammatory period may suggest the possible role of this mediator in the etiopathogenesis of psoriasis and the potential future use of NO inhibitors in the treatment of psoriasis.     

Partnering with gastroenterologists to evaluate patients with chronic constipation

Constipation is a highly prevalent and bothersome disorder that negatively affects patients' social and professional lives and imposes a heavy economic burden on patients and society. Most patients with chronic constipation are evaluated and treated in the primary care setting. Primary care clinicians often underestimate how much they can accomplish in the evaluation of a patient with constipation before they make a referral. There are numerous steps that primary care clinicians can take to address these issues and maximize the benefits of the referral process, including understanding key elements of an effective diagnostic work-up, familiarizing themselves with the utility of various diagnostic tests of colonic and anorectal function, implementing strategies/instruments to optimally communicate what they are striving to achieve through the referral process (eg, via a referral form), and developing a network of long-term working relationships with local gastroenterologists.     

光化学疗法治疗神经性皮炎60例临床疗效观察

采用光化学疗法,外涂0.2%8-MOP半小时后以光化肤康灯(主峰波长365 nm,终端输出功率25.4 W连续可调,幅照度:930μW/cm2)照射,治疗神经性皮炎60例,平均治疗间期1月,治愈率51.67%,显效率23.33%,有效率21.67%,无效率3.33%。未发现明显毒副作用。结果显示光化学疗法对神经性皮炎有很好的疗效。     

DEDD association with cytokeratin filaments correlates with sensitivity to apoptosis

The cytokeratin 8/18 (CK8/18) cytoskeleton network is an early target for caspase cleavage during apoptosis. Recent reports suggest that the highly conserved and ubiquitous death effector domain containing DNA binding protein (DEDD) plays a role in the recruitment of procaspase-9 and -3 at this CK8/18 scaffold. DEDD interacts with both the CK8/18 intermediate filament network and procaspase-3 and –9. It is suggested that the CK8/18 fibrils may provide a scaffold for the proximity-induced autocleavage and activation of procaspase-9 in close association with caspase-3. We addressed this issue by investigating DEDD staining patterns in various cell lines and by correlating these expression patterns with the sensitivity of these cell lines for roscovitine-induced apoptosis. We showed that in some cell lines DEDD revealed a bright filamentous staining pattern in others DEDD staining was weak and diffusely distributed in the cytoplasm of the cells. The difference in staining patterns was irrespective of the phosphorylation status of the cytokeratin filaments. In cells showing a filamentous staining pattern, DEDD was strongly associated with the CK8/18 cytokeratin filaments as evidenced by double immunofluorescence and its resistance to extraction with Triton X-100. Subcellular fractionation indicates that DEDD co-purifies with CK18, which corroborates a strong association of DEDD and the cytokeratin network. DEDD was either mono- or diubiquinated. Cells showing a filamentous DEDD distribution are more apoptosis-prone as evidenced by the rapid appearance of M30 CytoDeath-positive cells after induction of apoptosis. The sensitivity towards apoptosis is irrespective of the procaspase-3 content of the cells. Our data support the notion that DEDD-mediated accumulation of procaspases at the cytokeratin scaffold leads to an increase in the local concentration, which renders cells more apoptosis-prone.     

依达拉奉联合瑞舒伐他汀对高血压患者PCI术后对比剂肾病的预防作用

目的:探讨依达拉奉联合瑞舒伐他汀对高血压患者经皮冠状动脉介入治疗(PCI)后对比剂肾病的预防作用,旨在为高血压患者PCI术后的治疗提供参考。方法:选择120例择期行PCI术的高血压患者,随机分为依达拉奉组(ED组)、瑞舒伐他汀组(RO组)、依达拉奉与瑞舒伐他汀联合组(C组),各40例。ED组给予静脉滴注生理盐水100 mL+依达拉奉30 mg,每12小时一次;RO组给予瑞舒伐他汀10 mg口服,每晚一次;C组将2者联合应用。所有患者均于术前3天开始用药。观察3组患者入院时及术后第1天血尿素氮(BUN)、肌酐(Scr)、血清胱抑素(Cys C)、血清丙二醛(MDA)、超氧化物歧化酶(SOD)以及对比剂肾病的发病率。结果:ED组、RO组、C组CIN的发病率分别为10%、7.5%、2.5%,C组CIN发病率明显低于ED组与RO组,差异有统计学意义(P0.05)。术后C组Scr、BUN、Cys C、MDA浓度明显低于ED组与RO组(P0.05),SOD含量高于ED组与RO组(P0.05)。结论:依达拉奉联合瑞舒伐他汀能明显降低高血压患者PCI术后对比剂肾病的发病率,机制可能与抗氧化应激反应有关。     

Formation of cyclodextrins with cyclodextrin glucosyltransferase stimulated with polarized light

After illumination with white, linearly polarized light (WLPL), cyclodextrin glycosyltransferase produced mixture of α‐, β‐, and γ‐cyclodextrins (CD) with higher overall yield than did that enzyme when nonilluminated. The illumination also influenced the ratio of those CD and that effect depended on concentration of enzyme and illumination time. At a high enzyme concentration (0.64 U/cm³), regardless the illumination time, formation of β‐CD predominated. The highest yield of β‐CD was afforded after 1 h illumination and 2 h illumination led to a significant increase in the yield of γ‐CD. Three‐month storage of enzyme illuminated with WLPL did not reduce its enhanced activity. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009