红豆杉提取物中紫杉醇的反相高效液相色谱法测定

本文报道应用反相高效液相色谱法测定红豆杉提取物中紫杉醇的含量,以倍他米松作内标,在填充以10μm LiChrosorb RP-18固定相的250×4mm不锈钢柱上以甲醇-水(30:10v/v)作流动相。228 nm处检测。本法简便、快速、准确,适用于微量样品的测定。     

Expression of phosphorylcholine-specific B cells during murine development

The TEPC 15 (T15) clonotype, a putatively germline antibody specificity, does not appear in the neonatal B-cell repertoire until approximately 1 wk of age. This report extends this observation by the demonstration that (a) the T15 clonotype follows similar kinetics of appearance in germfree as well as conventionally-reared mice; (b) maternal influences and genetic background play a minor role in the development of the T15 clonotype since CBFI neonates raised by C57BL/6 or BALB/c mothers acquire the T15 clonotype at the same time in ontogeny as BALB/c neonates; (c) the lack of phosphorylcholine (PC)-specific B cells shortly after birth is reflected in a dearth of PC-binding cells in the neonate as well; and (d) no PC-specifc B cells are found in 19-day fetal liver or in bone marrow until 7 days of life, coincident with their appearance in the spleen. These findings, along with a previous report that PC-specific splenic B cells are tolerizable as late as day 10 after birth, confirm the invariant, late occurrence of the T15 clonotype and support a highly- ordered, rigorously predetermined mechanism for the acquisition of the B- cell repertoire. The results are discussed in light of other studies on the ontogeny of B-cell specificity, and in terms of the implications on the mechanism by which antibody diversity is generated.     

Hyaluronan-dependent motility of B cells and leukemic plasma cells in blood, but not of bone marrow plasma cells, in multiple myeloma: alternate use of receptor for hyaluronan-mediated motility (RHAMM) and CD44

We investigated the ability of blood B cells, bone marrow (BM) plasma cells, and terminal leukemic plasma cells (T-PCL) from patients with multiple myeloma (MM) to migrate on extracellular matrix proteins. Hyaluronan (HA), but not collagen type I, collagen type IV, or laminin, promoted migration of MM blood B cells, as determined by time-lapse video microscopy. Between 13% and 20% of MM blood B cells migrated on HA with an average velocity of 19 micron/min, and greater than 75% of MM blood B cells exhibited vigorous cell movement and plasma membrane deformation, as did circulating T-PCL and extraskeletal plasma cells from patients with MM. In contrast, plasma cells obtained from BM of patients with MM lacked motility on all substrates tested and did not exhibit cell membrane protrusions or cellular deformation. MM blood B cells and MM plasma cells from all sources examined expressed the HA- binding receptors receptor for HA-mediated motility (RHAMM) and CD44. On circulating MM B cells, both RHAMM and CD44 participated in HA- binding, indicating their expression ex vivo in an activated conformation. In contrast, for the majority of BM plasma cells in the majority of patients with MM, expression of RHAMM or CD44 was not accompanied by HA binding. A minority of patients did have HA-binding BM plasma cells, involving both RHAMM and CD44, as evidenced by partial blocking with monoclonal antibodies (MoAbs) to RHAMM or to CD44. Despite HA binding by both RHAMM and CD44, migration of MM blood B cells on HA was inhibited by anti-RHAMM but not by anti-CD44 MoAbs, indicating that RHAMM but not CD44 mediates motility on HA. Thus, circulating B and plasma cells in MM exhibit RHAMM- and HA-dependent motile behavior indicative of migratory potential, while BM plasma cells are sessile. We speculate that a subset(s) of circulating B or plasma cells mediates malignant spread in myeloma.     

Human milk contains elements that block binding of noroviruses to human histo-blood group antigens in saliva

Noroviruses (NVs) recognize human histo-blood group antigens (HBGAs) as receptors. We characterized the interaction of human milk samples with recombinant virus-like particles representing VA387, Norwalk, VA207, and MOH. Milk samples from 60 healthy women were tested for human HBGAs and for their ability to block the binding of NVs. Fifty-four women were secretors (Se+), and 6 were nonsecretors (Se-). No women had detectable A or B antigens in their milk samples. All 54 Se+ milk samples, but 0 of 6 Se- milk samples, blocked VA387 and Norwalk virus (Se+ binders) from binding to saliva samples. All 6 Lewis-positive Se- milk samples blocked binding to VA207, and variable blocking activities were exhibited by the Se+ milk samples. No milk samples blocked the binding of MOH to A and B antigens. Secretor and Lewis, but not A or B antigens, were present in human milk and were responsible for blocking NV binding to receptors and therefore are likely to be decoy receptors that protect breast-fed infants from NV infection.     

Evidence for direct action of human biosynthetic (recombinant) GM-CSF on erythroid progenitors in serum-free culture

The biologic activity of human biosynthetic granulocyte-monocyte colony stimulating factor (GM-CSF) was investigated in serum-free culture of erythroid progenitors derived from adult peripheral blood. The morphology of erythroid bursts and the cloning efficiency of BFU-E under serum-free conditions were similar to those observed in dishes with fetal bovine serum (FBS). For these experiments, progenitor cells were partially purified by Ficoll-Paque density centrifugation, adherence to a plastic surface, and complement-mediated cytotoxicity of Leu-1+ elements. For some studies, blastlike cells were harvested directly from 6-day-old semisolid cultures. In serum-free culture of the light-density cell fraction, biosynthetic erythropoietin (Ep) was sufficient for formation of pure and mixed erythroid colonies whereas GM-CSF was required for granulocyte-monocytic colonies. When adherent and Leu-1+ cells were removed, or when in vitro differentiated blast cells were used as a source of progenitors, neither Ep or GM-CSF alone induced colony formation. In dishes supplemented with both growth factors, erythroid bursts were detected. Although the presence of GM- CSF alone did not induce formation of any colony or clusters, BFU-E were recorded when Ep was added 8 days later, suggesting that BFU-E could be maintained. Terminal maturation of the resulting erythroid bursts was delayed by 8 days. These results provide evidence that GM- CSF acts directly on early erythroid progenitors. Furthermore, they suggest that both Ep and GM-CSF are necessary to start the differentiation process.     

Hair Contamination of Sheepdog and Pet Dogs with Toxocara canis Eggs

Background

We tried to investigate the hair contamination of pet dogs and farm sheepdog with Toxocara eggs in terms of the different sex and age groups in north-west of Iran (Urmia and its suburbs).

Methods

Hair samples were collected from a total of 138 pet and farm sheepdogs from November 2008 to June 2009 in Urmia City and the suburb (West Azerbaijan-Iran) and examined for the presence of T. canis eggs.

Results

T. canis eggs found in 60 samples altogether (pet and shepherd dogs) showed a contamination rate of 36.2%. The number of observed T. canis eggs in each microscope field was varied from 1 to > 400. The age of the dog was found a significant factor to influence the prevalence and intensity of contamination, with 82% of all the eggs recovered from puppies (six months and younger). Additionally, the numbers of eggs in farm sheepdogs were significantly higher than pet dogs (P<0.05).

Conclusion

This report shows that direct contact with T. canis infected dogs, particularly puppies from shepherd dogs, may pose a serious hazard to human. Besides, as they may harbor a considerable number of eggs on their hair, they can contaminate the soil and the environment.     

Introducing Alphitobius diaperinus, (Insecta: Tenebrionidae) as a New Intermediate Host of Hadjelia truncata (Nematoda)

Background

Hadjelia truncata is a nematode that causes lesions in the gizzard lining of pigeons, which may even lead to death. The aim of this study was to introduce Alphitobius diaperinus as a new intermediate host for Hadjelia truncata.

Methods

H. truncata infection was identified in a pigeon flock in Ahvaz City, Khuzestan Province, Iran by performing fecal examination and autopsy. Adult and larval stages of beetles were collected from the litter of pigeon houses, and identified morphologically. The beetle larvae were cultured in a medium, containing feces of the infected pigeons. Nematode larval stages from naturally and experimentally (culturally) infected adult beetles were fed to two groups of pigeons

Results

The collected beetles were identified as Alphitobius diaperinus. Average length and width of the adult beetles were 6.31 mm and 2.88 mm respectively. Infection rates of naturally and experimentally infected beetles with larval stages of the nematode were 66.2% and 45.1% respectively. The adult nematodes collected from gizzards of experimentally infected pigeons were identified as H. truncata. Nematode infection rates in pigeons after feeding the infective larvae collected from naturally and experimentally infected beetles were 44.7% and 32.5% respectively.

Conclusion

A. diaperinus can serve as a natural intermediate host for H. truncata.     

The coagulant-active phospholipid content is a major determinant of in vivo thrombogenicity of prothrombin complex (Factor IX) concentrates in rabbits

In vitro evaluation of prothrombin complex concentrates in a thrombin generation assay, using DAPA and purified components of the prothrombinase complex, demonstrated significant levels of coagulant- active "phospholipid replacing" activity. Quantification of this activity showed a significant correlation (r = 0.8747, p less than 0.01) with thrombogenicity measured in vivo in a stasis model in rabbits. Extracted lipid material retained full phospholipid replacing activity in the vitro assay. Thin-layer chromatographic characterization confirmed the presence of phospholipids with known coagulant activity in vitro. In vivo, the extracted material was nonthrombogenic but augmented the thrombogenicity of purified factor Xa. Substitution of a synthetic coagulant-active phospholipid (phosphatidylcholine-phosphatidylserine lipid vesicles) for the extracted phospholipid produced a similar augmentation of a factor-Xa- induced thrombogenicity in vivo. It is concluded that the coagulant- active phospholipid content of prothrombin complex concentrates is a major determinant of thrombogenicity but requires the presence of activated clotting factors for its expression in vivo.