Thrombotic Obstruction of the Björk-Shiley Aortic Valve Prosthesis. Report of Four Cases

We present four cases of late thrombotic obstruction of the Björk-Shiley aortic valve prosthesis. The incidence of this complication reported in the literature to vary from 0.7% to 5%. In our experience of a total of 623 Björk-Shiley aortic valve replacements, we observed this complication in only 4 patients (0.6%). Two of them had poorly controlled anticoagulation therapy. The clinical presentation was subacute in all four patients. Surgical treatment, thrombectomy and debridement, was performed in all of them. The diagnosis was made upon abrupt and progressive onset of dyspnoea, physical examination data and echocardiographic and radioscopic findings. Angiocardiographic studies were needed in two patients.     

Lipocalin-2 Regulates the Inflammatory Response During Ischemia and Reperfusion of the Transplanted Heart

Ischemia and reperfusion (IR) are known to negatively affect early allograft function following solid organ transplantation. Lipocalin-2 (Lcn-2) has been described as a marker and potential positive modulator of acute inflammation during these processes. Using a heterotopic murine heart transplant model we previously found that IR resulted in a pronounced upregulation of Lcn-2 mRNA in the heart at 12 (22.7-fold increase) and 24 h (9.8-fold increase) of reperfusion. We now confirm this increase at the protein level and provide evidence for infiltrating polymorphonuclear cells as the primary source of Lcn-2 protein. Lcn-2 levels are increased 6.6-fold at 12 h, 11.4-fold at 24 h and 6.4 fold at 48 h after reperfusion. In Lcn-2(-/-) grafts the number of infiltrating granulocytes is reduced by 54% (p < 0.05) at 2 h, 79% (p < 0.01) at 12 h, 72% (p < 0.01) at 24 h and 52% (p < 0.01) at 48 h after reperfusion compared to Lcn-2(+/+) grafts, without any differences in cardiomyocyte apoptosis. These data suggest a function of Lcn-2 in the initiation of the inflammatory response. Moreover, an increase in Lcn-2 is not only restricted to the transplanted heart, but is also observed in the kidney, hinting at a possible involvement of Lcn-2 in the systemic response to IR.     

Effects of psychosocial stress or food restriction on body mass and blood cellular immunity in laboratory rats

Immunological changes were studied in socially stressed loser rats and in rats restricted of food or water. Seven days of chronic social confrontation resulted in a significant loss of body mass as well as in marked alterations of blood cellular immunity in loser rats. Loser males showed increased numbers of granulocytes, reduced numbers of CD4 T cells, CD8 T cells, and B cells, as well as a lowered proliferative response of lymphocytes to concanavalin A. To test the possibility of whether the immunological change in loser males is a direct effect of altered nutritional state, non‐confronted males were restricted of food (?90 per cent) for 7 days to mimic the weight loss of loser males. While losers and food restricted males lost a similar 15 per cent of their initial body mass, their immunological outcome largely differed: food or water restriction had little immunological impact, except on granulocytes (reduced numbers). Obviously, social stress alters granulocyte numbers in a different direction than under food or water restriction. Together the data indicate that modulation of blood cellular immunity in loser males is unlikely to be caused by altered nutritional state during socially stressful confrontations. Copyright © 2001 John Wiley & Sons, Ltd.     

发热伴血小板减少综合征病例中无形体病鉴别诊断与治疗

目的 确定发热伴血小板减少综合征患者中是否存在人粒细胞无形体病(human granulocytic anaplasmosis,HGA),并进行HGA临床分析.方法 将2010年收治的42例发热伴血小板减少综合征患者血液标本,送中国疾病预防控制中心(Centers for Disease Control and Pre...     

Expression of an anti-CD33 single-chain antibody by Pichia pastoris

CD33 is a cell surface glycoprotein expressed on cells of myelomonocytic lineage, leukaemic cells, but not haematopoietic stem cells. By virtue of its expression pattern, CD33 has become a popular target for new immunotherapeutic approaches to treat acute myeloid leukaemia. The methylotrophic yeast Pichia pastoris strain KM71H was used to produce an anti-CD33 single chain variable fragment (scFv), with the intention of conjugation to a radioisotope, for therapeutic use. To direct secreted expression of the anti-CD33-scFv the alpha-mating factor secretory signal sequence (alpha-MF) was used, with constructs containing a complete (CS) and incomplete (INCS) cleavage site to accommodate the potential outcomes of dibasic endopeptidase, Kex2, and dipeptidyl amino peptidase, Ste13, processing. The anti-CD33-scFv was expressed in BMMY cultures using both constructs, with a final yield of 48 mg/l (CS) and 11 mg/l (INCS). N-terminal sequencing showed that the CS-scFv had not been cleaved by Ste13, leaving amino acids EAEA at the N-terminus. The INCS-scFv construct produced a mixture of 50% authentic scFv and 50% with 11 amino acids from the alpha-MF remaining at the N-terminus. Despite the aberrations in alpha-MF processing, the anti-CD33-scFv's produced from both constructs were found to be functional. Flow cytometry and Biacore analysis demonstrated binding to target antigen CD33 on the surface of human leukaemic cell line HL-60, and to recombinant soluble CD33 respectively.     

DNA adducts in granulocytes of hospital workers exposed to ethylene oxide

BACKGROUND: Ethylene oxide (EtO), an important industrial chemical intermediate and sterilant, is classified as a human carcinogen. Occupational EtO exposure in many countries is regulated at 1 ppm (8-hr TWA), but levels of EtO-DNA adducts in humans with low occupational EtO exposures have not been reported. METHODS: We examined the formation of N7-(2'-hydroxyethyl)guanine (N7-HEG), a major DNA adduct of EtO, in 58 EtO-exposed sterilizer operators and six nonexposed workers from ten hospitals. N7-HEG was quantified in granulocyte DNA (0.1-11.5 microg) by a highly sensitive and specific gas chromatography-electron capture-mass spectrometry method. Cumulative exposure to EtO (ppm-hour) was estimated during the 4-month period before the collection of blood samples. RESULTS: There was considerable inter-individual variability in the levels of N7-HEG with a range of 1.6-241.3 adducts/10(7) nucleotides. The mean levels in the nonexposed, low (< or =32 ppm-hour), and high (>32 ppm-hour) EtO-exposure groups were 3.8, 16.3, and 20.3 adducts/10(7) nucleotides, respectively, after the adjustment for cigarette smoking and other potential confounders, but the differences were not statistically significant. CONCLUSIONS: This study has demonstrated for the first time, detectable levels of N7-HEG adducts in granulocytes of hospital workers with EtO exposures at levels less than the current U.S. standard of 1 ppm (8-hr TWA). A nonsignificant increase in adduct levels with increasing EtO exposure indicates that further studies of EtO-exposed workers are needed to clarify the relationship between EtO exposure and N7-HEG adduct formation.     

In vivo kinetics of 111indium-labelled autologous granulocytes following i.v. administration of granulocyte-macrophage colony-stimulating factor (GM-CSF).

Administration of both glycosylated and non-glycosylated recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) induces an immediate transient granulocytopenia of 1-3 hours' duration. In order to explore this phenomenon, granulocytes were labelled with 111Indium and the effect on the kinetics of granulocytes after administration of rhGM-CSF was studied in 10 previously untreated patients with malignant lymphoma. For both types and doses of rhGM-CSF, a significant and dramatic accumulation of the 111Indium-labelled granulocytes was observed in the lung within a few minutes after i.v. injection of rhGM-CSF. The accumulation of radioactivity coincided with the pronounced and transient granulocytopenia in peripheral blood. The 111Indium-labelled granulocytes later reappeared in the peripheral blood, indicating reversible pulmonary vascular margination of the granulocytes. Half-life of labelled granulocytes after reappearance was comparable to half-life values under normal conditions. The transient accumulation of granulocytes in the pulmonary vessels seems not to be of clinical importance in the management of patients, but it may to some degree explain previously described side-effects, such as transient hypoxemia ("first-dose" reaction) following administration of rhGM-CSF.     

Typing of the granulocyte-specific NA antigens by restriction fragment length polymorphism analysis

SUMMARY. An RNA-based method has been developed to genotype donors for the granulocyte-specific alloantigens NA1 and NA2. mRNA was isolated from granulocytes, reversely transcribed into cDNA and amplified using an Fcgamma-receptor III-1 sequence-specific primer in the polymerase chain reaction (PCR). PCR products were analysed by restriction fragment length polymorphism (RFLP) using the restriction endonuclease Taq I, which provided a distinct restriction fragment pattern corresponding to the NA alleles. 17 donors were typed by PCR-RFLP and the results were in close accordance with those obtained by serological phenotyping by granulocyte immunofluorescence and the antigen capture assay MAIGA.     

Adsorptive granulocyte and monocyte apheresis for refractory Crohn’s disease: an open multicenter prospective study

Background Active Crohns disease (CD) is often associated with elevated levels of platelets, granulocytes, and monocytes that are activated and resistant to apoptosis. The level of neutrophils in the intestinal mucosa has been quantitatively related to the severity of intestinal inflammation in CD. We postulated that patients with CD that is refractory to conventional medications might respond to a reduction of granulocytes and monocytes by adsorptive apheresis.Methods Twenty-one patients with a CD activity index (CDAI) of 200–399 and unresponsive to standard medication, which included nutritional intervention, received granulocyte and monocyte adsorptive apheresis (GCAP) as an adjunct to their ongoing medication. GCAP was performed with an Adacolumn, which adsorbs granulocytes, monocytes, and a small fraction of lymphocytes (FcR and complement receptor-bearing leucocytes). Patients received one GCAP session/week for 5 consecutive weeks. CDAI, International Organization for the Study of Inflammatory Bowel Disease (IOIBD), and IBD questionnaire (IBDQ) scores were evaluated.Results During the initial conventional/nutritional therapy, no significant improvement was seen in any patient. However, at week 7 of GCAP therapy, significant improvements in CDAI, IOIBD, and IBDQ scores were observed. The CDAI, IOIBD, and IBDQ scores before GCAP were 275.6 ± 54.2, 3.4 ± 1.4, and 152 ± 22, respectively. The corresponding values after GCAP were 214.8 ± 89.2 (P = 0.0005), 2.54 ± 1.5 (P = 0.0224), and 165 ± 29 (P = 0.0327), respectively.Conclusions GCAP could be effective for inducing remission and improving quality of life in patients with active CD that is refractory to conventional therapy.