Prothrombin Houston: a dysprothrombin identifiable by crossed immunoelectrofocusing and abnormal Echis carinatus venom activation

A 72-yr-old male with a lifelong history of easy bruisability and posttraumatic bleeding had a prolonged prothrombin time and activated partial thromboplastin time. His plasma Stypven, Taipan, and Echis carinatus venom clotting times were prolonged. The presence of a dysprothrombin was confirmed by the discrepancy between plasma prothrombin coagulant activity and prothrombin antigen levels. His plasma prothrombin was capable of being completely absorbed onto and then eluted from barium sulfate. Crossed immunoelectrophoresis of his plasma prothrombin, and normal plasma prothrombin, into agarose containing rabbit anti-human factor II antibody were similar. Crossed immunoelectrofocusing, a procedure combining isoelectric focusing in disc gels with electroimmunoassay in the second dimension, demonstrated that the patient's prothrombin antigen was more basic than normal. The eluate from barium sulfate absorbtion of patient plasma, when reacted with Echis carinatus venom (which directly cleaves prothrombin to thrombin) clotted purified fibrinogen at a rate slower than normal plasma eluate. SDS-slab gel electrophoresis revealed that the prothrombin present in the patient's eluate was cleaved by Echis carinatus venom. These studies suggest that the coagulopathy of prothrombin Houston results from the generation of a dysfunctional thrombin.     

Marrow accessory cell infection and alterations in hematopoiesis accompany severe neutropenia during experimental acute infection with feline immunodeficiency virus

Severe neutropenia and bone marrow (BM) morphologic abnormalities occur during experimentally induced primary infection with feline immunodeficiency virus (FIV), a lentivirus biologically similar to human immunodeficiency virus (HIV). To further characterize the mechanisms involved in this acute infection model of lentivirus-induced BM suppression, peripheral blood counts, histologic BM studies, and BM culture assays were performed on 12 cats that underwent necropsy at regular intervals postinoculation (PI) with FIV Petaluma. Plasma viremia developed at week 3 PI and neutropenia was initially detected at week 6 PI. Low neutrophil counts, but normal hematocrits and platelet counts, persisted through week 12 PI. Infected BM mononuclear cells and megakaryocytes were identified by in situ hybridization assays for FIV nucleic acids in BM sections of cats that underwent necropsy at weeks 4 to 12 PI, correlating with detection of soluble FIV p24 antigen and identification of infected mononuclear and macrophage cells in BM buffy-coat cell cultures from these cats. At weeks 1.5 to 4 PI, the mean frequencies (number per 10(5) BM mononuclear cells) of erythroid progenitors (erythroid colony-forming units [CFU-E] and erythroid burst-forming units [BFU-E] and granulocyte/macrophage progenitors (CFU-granulocyte/macrophage [CFU-GM]) were increased to 508 +/- 74, 143 +/- 24, and 110 +/- 17, respectively (n = 5 cats) as compared with controls (172 +/- 24, 86 +/- 26, and 44 +/- 10; n = 3 cats; P < .02), and the percentages of progenitors in the DNA-synthetic phase of the cell cycle were equivalent to controls. In contrast, the progenitor frequencies at weeks 6 to 12 PI were significantly decreased (72 +/- 16, 43 +/- 6, and 19 +/- 4, respectively; n = 7 cats; P < .01), and these progenitors were more frequently in S-phase. Autologous serum significantly inhibited (P < .05) the growth of CFU-GM in 6 of 9 cats and failed to support the maximal growth of BFU-E in 4 of 9 cats studied at weeks 4 to 12 PI, whereas no such abnormalities were observed in colony assays containing autologous sera from control cats (n = 3) or cats studied at weeks 1.5 or 3 PI (n = 3). In comparison, sera from FIV-infected cats did not inhibit the growth of normal, allogeneic progenitors. However, FIV serum frequently failed to support maximal in vitro growth of normal CFU-GM as compared with uninfected allogeneic sera, further suggesting a lack of progenitor growth- promoting substances in infected cat sera.(ABSTRACT TRUNCATED AT 400 WORDS)     

Rapid detection of deletions causing delta beta thalassemia and hereditary persistence of fetal hemoglobin by enzymatic amplification

A considerable number of deletions of variable size and position that involve the beta-globin gene complex on chromosome 11 are associated with the clinical entities of hereditary persistence of fetal hemoglobin (HPFH) and delta beta thalassemia. Specific deletions appear to be associated with consistent phenotypes and some are known to be recurrent. To facilitate the molecular diagnosis of uncharacterized patients with HPFH and delta beta thalassemia, oligonucleotide primers have been designed to enzymatically amplify deletion-specific products for nine known deletions, which include those responsible for HPFH-1, HPFH-2, HPFH-3, Spanish (delta beta)zero thalassemia, hemoglobin (Hb) Lepore, Sicilian (delta beta)zero thalassemia, Chinese G gamma(A gamma delta beta)zero thalassemia, Asian-Indian inversion-deletion G gamma(A gamma delta beta)zero thalassemia, and Turkish inversion-deletion (delta beta)zero thalassemia. Using this approach, we have successfully characterized the molecular basis for delta beta thalassemia in 23 individuals from 16 families of diverse ethnic origins. Thirteen individuals from this group were shown to be heterozygous for the 13.4- kb Sicilian deletion, two were heterozygous for the 100-kb Chinese G gamma(A gamma delta beta)zero deletion, four were heterozygous for the Turkish form of inversion-deletion delta beta thalassemia, and three were heterozygous for the Asian-Indian form of inversion-deletion G gamma(A gamma delta beta)zero thalassemia. One Vietnamese subject was heterozygous for a 12.6-kb deletion, which we have fully characterized at the molecular level. Sequence analysis of the breakpoint regions of the Chinese deletion and the Turkish rearrangement indicates that, in each case, the mutation is likely to have arisen from a single origin. This hypothesis is supported by the evident geographical clustering of the various deletions described here.     

A cell line secreting stimulating factors for CFU-GEMM culture

The multipotent hemopoietic stem cell has fastidious growth requirements in vitro. Traditionally, phytohemagglutinin-stimulated leukocyte conditioned medium has been used to supply the undefined growth factors required for culture of the human multipotent hemopoietic progenitor. We describe the use of medium conditioned by the bladder carcinoma cell line, 5637, to replace PHA-LCM in CFU-GEMM cultures and show that the properties of this conditioned medium closely mimic those of PHA-LCM in two separate CFU-GEMM culture systems.     

食管球囊联合超细胃镜扩张贲门失弛缓症1例

对1例中年贲门失弛缓症患者于超细胃镜直视下应用食管球囊预扩张一次的基础上,将胃镜插至胃底反转对球囊定位后再次扩张.扩张口径满意,无穿孔；症状缓解,随访1mo无复发.     

胃黏膜保护的基础与临床研究进展

长期以来胃黏膜保护一直是基础和临床研究的重点与热点.近年来人们对胃黏膜保护的细胞和分子机制已有了全面深入的认识,发现具有胃黏膜细胞保护作用的物质有很多种,具有细胞保护作用的器官和组织也不仅仅限于胃黏膜,在胰腺、肝脏、肾脏、心脏和脑等都发现有类似现象.因此细胞保护概念的内涵和外延都有拓展.我们对三叶因子、氧自由基、幽门螺杆菌、酒精、非甾体类抗炎药及细胞因子等研究热点与胃黏膜保护相互作用的机制进行初步的探讨.     

Genetic differences in red cell osmotic fragility: analysis in allophenic mice

Mice of strain DBA/2J were found to produce red cells considerably more resistant to osmotic lysis than cells from C57BL/6J or the F1 hybrid between the two strains. Such strain-specific differences in osmotic fragility could be the result of genetically determined humoral or other systemic differences that indirectly influence red cell properties. Alternatively, this phenotypic variation might be an inherent property of the erythrocyte themselves and be directly controlled by their genotype. Analysis of red cells from allophenic (mosaic) mice of the strain composition C57BL/6J in equilibrium DBA/2J demonstrated that the latter possibility is the case. In such mice, erythrocytes of the DBA/2J genotype are relatively more resistant to osmotic lysis than are those of the C57BL/6J genotype; partial lysis of allophenic blood at intermediate salt concentrations results in marked enrichment for DBA/2J cells among the survivors. Future experiments designed to determine the mechanism underlying this difference can now focus on the properties of the red blood cells per se with the certainty that this property is inherent to the genotype of each cell.     

Platelet-type von Willebrand's disease: characterization of a new bleeding disorder

An autosomally transmitted bleeding diathesis sharing some, but not all, features previously described in von Willebrand's disease (vWd) was studied in five patients representing three generations of a single family. Bleeding times in the upper normal range in conjunction with low-normal platelet counts, normal factor VIII coagulant activity and VIII-related antigen, decreased VIII-ristocetin cofactor activity, selective decrease of the higher molecule weight factor VIII/von Willebrand factor (VIII/vWF) multimers, and increased ristocetin- induced platelet agglutination at low ristocetin concentrations were characteristic. Binding of patient VIII/vWF to washed normal platelets was within normal limits, whereas binding of normal VIII/vWF to patient platelets was significantly increased (p less than 0.001 at 0.6 mg/ml ristocetin). This disorder accordingly appears to involve an intrinsic platelet abnormality affecting platelet-VIII/vWF interactions. It is proposed that the concept of vWD be broadened to include patients with this abnormality, which may appropriately be called "Platelet-type von Willebrand's disease."