Deoxygenation-induced changes in sickle cell-sickle cell adhesion

The tendency for sickle cells to adhere to each other is increased in oxygenated sickle blood in parallel with cell density. The increased adherence of these cells occurred despite their reduced deformability and diminished ability to form rouleaux. Using a method developed in our laboratory, we measured the yield stress: a sensitive index of cell- cell adhesion of deoxygenated suspensions of sickle cells. Deoxygenation of whole sickle blood to 30 to 50 mm Hg caused a significant increase in yield stress of all sickle blood samples. Deoxygenation caused a significant increase in yield stress of both dense and light sickle cells. Deoxygenation-induced increases in yield stress occurred at higher oxygen tensions for dense (> 55 mm Hg) than for light sickle cells (< 45 mm Hg). The increase in yield stress on deoxygenation was correlated with hemoglobin polymerization as assessed morphologically by sickling or by changes in relative viscosity. Thus, deoxygenation-induced cell sticking must involve small areas of strong membrane adhesion because the changes in yield stress occurred despite a reduction in rouleaux formation and surface area of membrane contact. Sickle trait red blood cells also exhibited increased yield stress on deoxygenation but only under hypertonic conditions where sickling occurred. Thus, deoxygenation-induced cell adhesion did not require prior membrane damage because it occurred in sickle trait cells. No change in yield stress was seen when deoxygenated sickle cells were suspended in buffer, but the addition of physiologic amounts of fibrinogen to buffer restored the deoxygenation-induced increase in cell adhesion. We speculate that the increase in sticking among sickle cells on deoxygenation results from spicule formation and may involve interaction of fibrinogen and possibly other plasma proteins with the cell membrane.     

石南藤、山蒟活性成分的分离和结构鉴定

已报道自山蒟及石南藤中分得海风藤酮(Ⅰ),denudatin B(Ⅱ),N-isobutyl-deca-trans-2-trans-4-dienamide(Ⅲ),本文继续报道自山蒟中分得一新木脂素,命名为山蒟素D(Ⅳ),X-衍射晶体结构测定为外消旋光学异构体。自石南藤分得Ⅳ的同系物,为新结构、命名为南藤素(Ⅴ),以及山蒟素C(Ⅵ),galgravin(Ⅶ),二氢毕拨明宁碱(Ⅷ)及巴豆环氧素(Ⅸ)。以上化合物皆首次自山蒟及石南藤中分得。以血小板活化因子(PAF)引起的血小板凝集实验测定活性,除Ⅲ,Ⅳ,Ⅶ,Ⅸ外皆有抑制活性。     

Increased detection of hepatitis C virus infection in commercial plasma donors by a third-generation screening assay

BACKGROUND: Routine screening of blood donations with second-generation hepatitis hepatitis C virus (HCV) assays has substantially reduced the occurrence of posttransfusion hepatitis. However, following the development of third-generation assays, several studies indicated that these assays may identify HCV-infected individuals who are not identified by second-generation assays. STUDY DESIGN AND METHODS: The sensitivity of a third-generation HCV enzyme-linked immunosorbent assay (ELISA-3) was compared with a second-generation ELISA (ELISA-2) in a side-by-side study of 9936 commercial blood donors. ELISA-reactive specimens were subjected to supplemental analysis by third-generation recombinant immunoblot assay and polymerase chain reaction. RESULTS: ELISA-3 demonstrated greater sensitivity than ELISA-2, detecting 1 additional recombinant immunoblot assay-positive specimen per 2000 tested. ELISA-3 also detected 1 additional HCV-infectious polymerase chain reaction-positive unit among approximately 10,000 units screened. CONCLUSION: The incremental sensitivity achieved with ELISA-3 can be expected to eliminate approximately 20 infectious donations per week among those made by commercial donors in the United States. In accordance with previous studies, most of the improved sensitivity of ELISA-3 derives from its increased detection of anti-c33c (NS3), rather than from the inclusion of HCV antigen NS5.     

Clinical application of human egg cryopreservation

Clinical egg cryopreservation has been applied during a 4-year period with some limited success. Mostly mature and a few immature eggs were frozen slowly and thawed rapidly in 1,2-propanediol and sucrose, and subsequently inseminated by intracytoplasmic sperm injection (ICSI). Three studies were performed in which: (i) it was established that 55% of aged unfertilized mature eggs survive freezing; (ii) in 22 cycles of thawed donated eggs cryosurvival was 24% with 15 cycles reaching transfer, and five pregnancies were initiated, one of which went to term at 39 weeks with fraternal twin boys, and one remains ongoing at 37 weeks; and (iii) in five cycles, where in-vitro fertilization patients had some of their own eggs frozen/ thawed, cryosurvival of mature eggs was poor at only 2.2%, although 44% sibling germinal vesicle (GV) stage eggs survived. A normal female infant delivered at 40 weeks arose from transfer of two embryos where GV eggs underwent in- vitro maturation post-thaw and were fertilized by ICSI. Pregnancies reported here and by others indicate a burgeoning awareness of the potential benefits of egg cryopreservation, prompting cautious optimism for the future of this technology.      

k阿片受体激动剂抑制大鼠吗啡戒断症状的发生

用多次注射吗啡的方法造成大鼠对吗啡的依赖，给大鼠脊髓蛛网下腔（ｉ．ｔ．）注射ｋ（ｋａｐｐａ）阿片受体激动剂Ｕ－５０，４８８Ｈ（２．５、５、１０μｌ）或ｋ受体拮抗剂ｎｏｒ—ＢＮＩ（１．２５、２．５、５μｌ／１０μｌ）后，用纳洛酮（ＮＸ）催瘾，观察并记录四种戒断症状：湿科（ｗｅｔｓｈａｋｅｓ）、咬牙（ｔｅｅｔｈｃｈａｔｔｅｒｉｎｇ）、逃跑企图（ｅｓｃａｐｅａｔｔｅｍｐｔｓ）、体重丢失（ｗｅｉｇｈｔｌｏｓｅ）。结果表明Ｕ—５０，４８８Ｈ可以明显减轻湿抖、咬牙和逃跑企图，并呈量效关系；ｎｏｒ—ＢＮＩ则使温抖、咬牙和体重丢失三种症状明显加重，也呈量效关系。上述结果表明，激活脊髓。受体对吗啡戒断症状有明显的抑制作用，阻断Ｋ受体则加重戒断症状。     

头孢噻肟在实验性糖尿病鼠的药代动力学和药效学研究

用四氧嘧啶(alloxan)引起的大鼠糖尿病模型,观察糖尿病早期对头孢噻肟(CTX)药代动力学和药效学的影响。HPLC方法测定CTX的血药浓度,用计算机计算各项药代参数。糖尿病组动物的血药峰浓度和AUC值明显低于对照组,但两组的T_1/2ka和T<>/i>_1/2ke无明显差别,提示糖尿病早期不影响CTX的吸收和消除速度。但由于CTX的蛋白结合率降低,游离药物浓度增加,大量游离药物进入组织液,可使血中药物总浓度降低。CTX对两组动物肺炎球菌感染的PD₅₀无明显差别,可能与糖尿病大鼠血中游离的药浓度提高有关。     

Parathyroid hormone resistance and B cell lymphopenia in propionic acidemia

The mechanisms of hypocalcemia, recurrent infections and hypogammaglobulinemia associated with metabolic decompensation of propionic acidemia due to propionyl-CoA carboxylase deficiency have not been defined. A 7-week-old infant with this disorder presented with severe hypocalcemia and B cell lymphopenia during an episode of metabolic acidosis and hyperammonemia. Hypocalcemia (1.1 mmoll ¹) was associated with elevated serum intact parathyroid hormone (122 ng 1 ¹), hyperphosphatemia, hypophosphaturia and hypercalcuria, indicating parathyroid hormone resistance. B cell lymphopenia (20 cells μl^-1) was associated with transient neutropenia, anemia and subsequent hypogammaglobulinemia (IgG < 294mgdl^-1, IgM < 8mgdl^-1, IgA < 8mgdl ¹), while T cells were normal. Parathyroid hormone resistance and B cell lymphopenia resolved following treatment with hemodialysis, diet and carnitine. These complications may be due to interference with parathyroid hormone renal tubular action and B cell maturation/proliferation by accumulated organic acids.     

氟康唑治疗复发性真菌性阴道炎32例

0　引言　真菌性阴道炎是妇科常见病 ,常因治疗不彻底 ,反复发作而转为慢性 .2 a来我们采用氟康唑治疗复发性真菌性阴道炎 32例 ,取得较好疗效 .1　对象和方法1.1　对象　本组 32例 ,年龄 18～ 6 2 (平均 33岁 ) .未婚 2例 .已婚 30例 ,病程 0 .5～ 8a,平均 10 mo.诊断 :1明显自觉症状 :外阴、阴道瘙痒、烧灼感 ,皮肤粘膜充血 ,白带增多、豆渣样 .2阴道分泌物涂片 :显微镜下找到菌丝及芽孢 .3反复发作 :1a内有 4次复发症状出现 ,除外其他病变 [1 ,2 ] .1.2　方法　氟康唑由第二军医大学药学院提供 ,15 0 mg顿服 ,2～ 3wk1次 .治疗期间停用与…