严重烧伤患者外周血T淋巴细胞亚群、NK细胞活性及sIL-2R水平的变化

目的观察严重烧伤患者伤后T淋巴细胞亚群、NK细胞活性和sIL2R水平的变化,探讨其免疫功能改变的可能机制。方法测定35例严重烧伤患者伤后T淋巴细胞亚群,NK细胞活性和sIL2R的水平,并与正常对照组进行比较。结果与正常对照组比较,烧伤组:CD3+、CD4+和CD4+/CD8+比值均明显下降(P均<0.01),CD8+明显升高(P<0.05),烧伤组NK细胞活性明显下降(P<0.05),sIL-2R明显升高(P<0.01)。结论严重烧伤患者T淋巴细胞亚群中细胞比例发生了明显改变,NK细胞活性降低sIL-2R水平升高,三者互相影响,共同构成烧伤患者伤后免疫功能紊乱的因素之一。     

Translumbar catheter redirection using a tip-deflector technique

A new technique is described for reversing the direction of the catheter tip during translumbar aortography, without the need for partial withdrawal of the catheter from the aortic lumen. The method ensures optimal delivery of contrast medium at the desired level, while avoiding the risk of retroperitoneal bleeding or dislodgement during catheter manipulation.     

Tryptophan 650 of human granulocyte colony-stimulating factor (G-CSF) receptor, implicated in the activation of JAK2, is also required for G- CSF-mediated activation of signaling complexes of the p21ras route

Granulocyte colony-stimulating factor (G-CSF) induces rapid phosphorylation of JAK kinases as well as activation of the p21ras route through interaction with its specific receptor (G-CSF-R). The cytoplasmic membrane-proximal region of G-CSF-R (amino acids 631 to 684) is necessary for proliferation induction and activation of JAK2. In contrast, activation of Shc and Syp, signaling molecules implicated in the p21ras signaling route, depends on the phosphorylation of tyrosine residues located in the membrane-distal region (amino acids 685 to 813) of G-CSF-R. We investigated whether G-CSF-induced activation of signaling complexes of the p21ras route depends on the function of the membrane-proximal cytoplasmic region of G-CSF-R. A G- CSF-R mutant was constructed in which tryptophan 650 was replaced by arginine and expressed in BAF3 cells (BAF/W650R). In contrast to BAF3 cell transfectants expressing wild-type G-CSF-R, BAF/W650-R cells did not proliferate and did not show activation of JAK2, STAT1, or STAT3 in response to G-CSF. Immunoprecipitations with anti-Shc and anti-Grb2 antisera showed that mutant W650R also failed to activate Syp and Shc. These data indicate that the membrane-proximal cytoplasmic domain of G- CSF-R is not only crucial for proliferative signaling and activation of JAK2 and STATs, but is also required for activation of the p21ras route, which occurs via the membrane-distal region of G-CSF-R.     

Multicenter trial of octreotide in patients with refractory acquired immunodeficiency syndrome-associated diarrhea

Diarrhea is a significant problem in patients with acquired immunodeficiency syndrome (AIDS). The aim of this study was to determine octreotide effectiveness in refractory AIDS-associated diarrhea. In a 3-week protocol, 129 patients with a stool weight of >500 g/day despite standard antidiarrheal therapy were randomized to receive octreotide or placebo (3:2 ratio). Octreotide dose was increased 100 μg weekly to a maximum of 300 μg three times a day based on weekly 72-hour stool collections. Subsequently, patients received open-label octreotide at doses of up to 500 μg three times a day. A 30% decrease in stool weight defined response. After 3 weeks, 48% of octreotide- and 39% of placebo-treated patients had responded (P = 0.43). At 300 μg three times a day, 50% of octreotide- and 30.1% of placebo-treated patients responded (P = 0.12). At a baseline stool weight of 1000–2000 g/day, 57% of octreotide- and 25% of placebo-treated patients responded (P = 0.06). Response rates based on CD4 counts, diarrhea duration, body weight, human immunodeficiency virus risk factor, and presence or absence of pathogens showed no benefit of octreotide. Adverse events were more frequent in the octreotide-treated group. In the doses studied, octreotide was not more effective than placebo in patients with refractory AIDS-associated diarrhea. This lack of effectiveness may be attributable to inadequate sample size, doses, and duration of study treatment.     

Hepatosplenic T-cell lymphoma: sinusal/sinusoidal localization of malignant cells expressing the T-cell receptor gamma delta

Peripheral T-cell lymphomas consist of a clinically heterogeneous group of malignant disorders whose immunophenotype usually corresponds to that of normal mature T cells. We describe and correlate the clinical, histopathologic, phenotypic, and genotypic findings in two patients with malignant lymphoma presenting with hepatosplenic disease. The morphologic pattern of lymphoma was that of a sinusal/sinusoidal infiltration in spleen, marrow, and liver. This morphologic characteristic was associated with the presence of a productive clonal rearrangement of the T-cell receptor (TCR) delta gene. Lymphoma cells expressed a CD3-TCR-gamma delta- phenotype. They were also double negative (ie, CD4-CD8-) and lacked the CD5 and CD7 antigens. In one patient, tumor progression was associated with phenotypic changes that resulted in a CD3-TCR-gamma delta- phenotype with the same delta-gene rearrangement as initially. These observations suggest the existence of a new type of peripheral T-cell lymphoma characterized by its hepatosplenic presentation, and by the sinusal/sinusoidal tropism and the TCR-gamma delta phenotype of the malignant cells.     

Fetal liver cells produce both fetal and adult erythrocytes in semiallogeneic radiation chimeras: possible influence of adult environment

Two kinds of erythrocytes are released in the blood of irradiated adult hybrid mice grafted with parental fetal liver cells: fetal antigen- bearing erythrocytes (Ft+ cells) and adult-type Ft- erythrocytes. Both are of parental origin, as determined by immune lysis using histocompatibility alloantigens. The latter cells make up all the recipient's red blood cells 2 mo after receipt of the graft, Ft+ cells then being no longer detected. The transient duality of erythropoiesis in irradiated adults grafted with fetal liver cells has been confirmed by studying the kinetics of CFU-E populations, as characterized by their ability to give rise to Ft+ or Ft- erythrocytes. The results are discussed in terms of environmental factors that influenc erythroid differentiation.     

Comparing human and mouse salivary glands: A practice guide for salivary researchers

Mice are a widely utilized in vivo model for translational salivary gland research but must be used with caution. Specifically, mouse salivary glands are similar in many ways to human salivary glands (i.e., in terms of their anatomy, histology, and physiology) and are both readily available and relatively easy and affordable to maintain. However, there are some significant differences between the two organisms, and by extension, the salivary glands derived from them must be taken into account for translational studies. The current review details pertinent similarities and differences between human and mouse salivary glands and offers practical guidelines for using both for research purposes.