A technique for the flow cytometric analysis of lymphocytes bearing histamine receptors

Histamine receptors have been demonstrated on lymphocyte membranes by a variety of techniques. We now report a method that allows for the flow cytometric analysis of histamine receptors on human peripheral T cells. Histamine is conjugated to fluoresceinated human albumin by the coupling agent ECDI. This conjugated histamine compound (FHA-his) binds to approximately 45% of T cells. Fluoresceinated human albumin alone (FHA), not conjugated to histamine, does not bind to T cells. In addition, unconjugated histamine can inhibit completely the binding seen with FHA-his. We conclude that this technique demonstrates specific FHA-his binding to histamine receptors on T cells and can be used to determine the number of cells bearing such receptors. In addition, the reagent could be used with a cell sorter to isolate distinct histamine-receptor-bearing (HR+) cells for further immunologic study.     

The cytoplasmic domain of P-selectin is phosphorylated on serine and threonine residues

P-selectin is an adhesion receptor for leukocytes that is redistributed from secretory granule membranes to the surfaces of activated platelets and endothelial cells. The cytoplasmic domain of P-selectin contains two serines, two threonines, and one tyrosine that could potentially be phosphorylated. We found that P-selectin was phosphorylated in both platelets and endothelial cells and that phosphorylation rapidly increased after cell activation. Approximately 0.02, 0.05, and 0.08 mol of phosphate/mol of P-selectin were incorporated, respectively, into resting, thrombin-activated, and phorbol ester-activated platelets. Phosphorylation was completely inhibited by the protein kinase C inhibitors, staurosporine, H-7, and chelerythrine, and was enhanced by the phosphatase inhibitors, okadaic acid and calyculin-A. Phosphoamino acid analysis of 32P-labeled P-selectin showed that phosphorylation occurred predominantly on serine with lesser amounts on threonine. When expressed in transfected Chinese hamster ovary cells, P-selectin was also phosphorylated. Mutagenesis studies showed that Ser788 was the principal site of phosphorylation, with minor sites on the other serine and threonine residues of the cytoplasmic domain. Phosphorylation may regulate membrane trafficking or other functions of P-selectin.     

Marrow transplantation from HLA-identical siblings for treatment of aplastic anemia: is exposure to marrow donor blood products 24 hours before high-dose cyclophosphamide needed for successful engraftment?

The present study in patients with aplastic anemia was undertaken to determine whether exposure of recipients to donor blood products 24 hr before preparation with cyclophosphamide (1) enhanced the rate of sustained engraftment of marrow from HLA-identical siblings as suggested by animal experiments, (2) increased the rejection rate, in particular in transfused patients who may already have been exposed to donor antigens by blood products, or (3) was of no relevance to the outcome of transplantation of marrow from HLA-identical siblings. One- hundred fifty-five patients were studied, of whom 78 received blood products from the marrow donor 24 hr before cyclophosphamide and 77 did not. A binary logistic regression analysis was applied to the data, simultaneously considering five previously known risk factors for rejection. Results showed that preceding transfusion of donor blood products had neither a significant beneficial nor detrimental effect on the incidence of sustained engraftment.     

Overexpression of HER-2 as a resistance mechanism to hormonal therapy for breast cancer

Hormonal therapy leads to improved survival in oestrogen receptor (ER) positive early breast cancer and long-term responses in advanced disease. However, resistance to such therapy is a serious clinical problem. This article considers the data for and against there being a significant role for the oncogene HER-2 in such resistance. Transfection of HER-2 into MCF-7 cells leads to resistance to tamoxifen but data differ in relation to the oestrogen dependence of such cells. A number of retrospective studies have been conducted of HER-2 status in adjuvant trials of tamoxifen. Most of these also suggest a negative role but individually the studies do not have the statistical power to be conclusive. Recent studies in the neoadjuvant context have shown a significant antiproliferative effect of endocrine therapy in HER-2 positive/ER positive tumours but this is much less than in HER-2 negative/ER positive tumours. It is concluded that incomplete hormonal resistance results from co-expression of HER-2 and ER and that this may differ between different hormonal agents.     

Acute myelogenous leukemia: recent advances in therapy

Results of treatment of AML have improved over the last decade. With modern remission induction chemotherapy, most patients achieve complete remission. The median remission duration is now 1 to 2 years, and a substantial fraction of patients achieve long-term disease-free survival. Bone marrow transplantation provides an improved antileukemic effect compared with chemotherapy alone, and it is the treatment of choice for selected groups of patients. The major limitation is the risk of transplant-related mortality. Most patients are not currently eligible for bone marrow transplants because of advanced age or lack of a histocompatible donor. Autologous marrow transplantation may be effective in selected setting, but this remains investigational at present. Substantial improvement in results of treatment of AML requires the development of new and effective chemotherapeutic agents that are non-cross-resistant with available drugs. Results of bone marrow transplantation may substantially improve if innovative measures to prevent major complications are successful.     

Abnormal sphincter of oddi response to cholecystokinin in postcholecystectomy syndrome patients with irritable bowel syndrome

Standard biliary manometry, including cholecystokinin (CCK) provocation, was performed on 42 consecutive patients (36 F, 6 M, median age 45 years) with postcholecystectomy syndrome (PCS) who had no evidence of organic disease but who had objective clinical features suggesting sphincter of Oddi dysfunction (SOD) (classes I and II). Patients were subdivided into those with (N=14) and without (N=28) irritable bowel syndrome (IBS) using a validated symptom questionnaire based on the modified Rome criteria. Resting sphincter of Oddi (SO) motor parameters (basal pressure, contractile amplitude and frequency, and proportion of retrograde contractions), the presence of abnormal manometry, and the presence of an abnormal response to CCK were compared in the two groups. No significant differences in resting parameters of SO motor activity between patients with and without IBS were observed, and abnormal biliary manometry as a whole was not more prevalent in either group (8/13 and 18/27, respectively). An abnormal response to CCK (failure of complete inhibition of phasic contractions), however, was demonstrated in five of 12 patients with IBS compared with only one of 23 patients without IBS (P=0.01). In patients with postcholecystectomy SOD, an abnormal response of the SO to CCK thus appears to be an important feature of the subset of patients with concomitant IBS.     

肝纤维化的发生机制与治疗进展

肝纤维化是各种致病原因引起细胞外基质(ECM)在肝内过多沉积的病理过程．在细胞和分子发病机制方面的研究显示,细胞因子作用于窦周间隙静止的肝星状细胞(HSC)使其转变为激活状态,继而增殖,合成ECM．因此认为激活的HSC是产生ECM的主要细胞,其他如肝静脉区成纤维细胞和骨髓源性肌成纤维细胞也是某些肝纤维化初期的主要纤维原性细胞．目前认为,进展性肝纤维化具有可逆性．药物旨在通过抑制HSC的激活、诱导其凋亡和防止ECM沉积的干预性治疗在实验性肝纤维化已取得疗效,但人类抗肝纤维化的有效性和安全性有待于进一步研究和论证．     

Marrow harvesting from normal donors

The experience at a single institution in harvesting marrow for allogeneic transplantation on 1,270 occasions from 1,160 normal donors is presented in detail, together with an analysis of all the donor complications. Four donors were less than 2 years old, and the youngest was 6 1/2 months. No special difficulties were encountered with these young donors. Hospitalization time was three days or less for 99% of the procedures. Six donors had life-threatening complications; three of a cardiopulmonary and two of an infectious nature, and one cerebrovascular embolic episode. Significant operative site morbidity, usually transient neuropathies, occurred in ten procedures. Ten percent of the donations were associated with transient postoperative fever of unknown origin. Increasing donor age was associated with a reduction of the cellularity of the marrow harvest. The use of stored autologous blood permitted the avoidance of blood bank transfusion in 81% of males, 69% of females, and 50% of children. It was concluded that the procedure was associated with a very low risk of complication, but that the involvement of normal donors in such an operation justifies stringent monitoring.     

Prevention of graft rejection following bone marrow transplantation

Bone marrow transplantation from an HLA-identical sibling is increasingly used in the treatment of severe aplastic anemia. One major problem with this approach is graft rejection that occurs in 25%-60% of patients conditioned for transplantation with cyclophosphamide. At most transplant centers it has been difficult to accurately identify patients at high risk for graft rejection. We studied a conditioning regimen of cyclophosphamide (200 mg per kg) and low-dose total body irradiation (3 Gy; equivalent to 300 rad) in 23 consecutive unselected patients with aplastic anemia followed for a minimum of 6 mo. There was only one episode of graft rejection. Graft-versus-host disease and interstitial pneumonitis were not increased by the more intensive conditioning regimen. Actuarial survival was 61% at 1 yr and 49% at 2.5 yr. Cyclophosphamide and low-dose total body irradiation is an effective conditioning regimen in patients with aplastic anemia. It may be particularly useful when accurate predictive tests of graft rejection are not available as is the case in most transplant centers.     

Allogeneic marrow transplantation for refractory anemia: a comparison of two preparative regimens and analysis of prognostic factors

From 1990 to 1993 we performed a prospective study of busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) in 30 patients with refractory anemia (RA) undergoing related (n = 17) or unrelated (n = 13) donor marrow transplantation. Nineteen patients survive disease free (63% 3- year actuarial disease-free survival [DFS]) and no patient relapsed. These results were compared to those of 38 historical controls with RA treated with cyclophosphamide and total body irradiation, of whom 22 are disease-free survivors and 1 relapsed. After correcting for significant variables between the two treatment groups, we found no statistically significant difference in outcome based on preparative regimen. Combining data from these 68 patients plus 2 additional patients with RA treated before 1993 with busulfan and cyclophosphamide, we identified four variables independently associated with improved survival: younger age, shorter disease duration, lower neutrophil count pretransplant, and lower hematocrit pretransplant. We also found that 15 patients 40 to 55 years of age had a 46% 3-year actuarial DFS and 26 patients receiving unrelated or mismatched related donor marrow had a 50% 3-year actuarial DFS. We conclude that there does not appear to be any significant difference in outcome based on preparative regimen in this patient population. In addition, allogeneic bone marrow transplantation may be a reasonable approach to therapy of RA early after diagnosis. However, whether early intervention with transplantation prolongs survival over that expected without transplantation cannot be ascertained with certainty from available data.