X-linked syndrome of platelet dysfunction, thrombocytopenia, and imbalanced globin chain synthesis with hemolysis

An unusual family is described with a congenital bleeding disorder present in four males belonging to three generations. Of the three surviving affected males, all had splenomegaly and petechiae. The three had moderate thrombocytopenia (55-90 X 10(9)/liter) and markedly prolonged Ivy-template bleeding times (greater than 30 min). They were also noted to have reticulocytosis and, upon further investigation, imbalanced globin chain synthesis resembling that of beta-thalassemia minor. Studies on nine additional family members in four generations were normal except for slight elevations of reticulocyte counts in female members, one of whom had the abnormal globin chain synthesis ratio. In male members, the bleeding tendency and clinical signs always occurred in the presence of the globin chain synthesis defect and reticulocytosis. This previously undescribed condition was apparently transmitted as an X-linked disorder.     

pH-induced platelet ultrastructural alterations. A possible mechanism for impaired platelet aggregation.

After the observation that lavages with alkaline solutions exert a beneficial effect on the bleeding tendency and increase platelet aggregation in patients with intragastric hemorrhage, studies were undertaken to find a relationship between changes of pH and platelet morphology. Transmission and scanning electron microscopy showed that at a pH lower than 7.4, normal human platelets change their internal structure as well as their shape, becoming spheres deprived of pseudopodia. On the other hand, a pH higher than 7.4 induces transformation of platelet internal organelles similar to that caused by thrombin. At an alkaline pH, the platelets develop multiple pseudopodia that facilitate their attachment to each other. These findings may explain the increased platelet aggregation in alkaline medium demonstrated in one of our previous works.     

基于受体结构的药物分子设计系统:维甲类分子与其结合蛋白之间相互作用的研究

大分子解剖程序,配体分子契合适配和DOCK程序,以及计算化学的其它程序等,已集成为基于受体结构和分子间相互作用的进行分子设计的软件系统,定名为BIOS(Biomolecularinteractionsandorientationsimulator)。BIOS软件可在普通的微机上运行。使用BIOS分别剥离了细胞浆维甲结合蛋白(CRBP)和副睾维甲酸结合蛋白(E-RABP)两种蛋白的配体结合腔,剥离是围绕配体以同样的分子距离进行的。从而得到了芳香性残基分布相似的两个结合腔,其结合位点的几何排布却有相当差别。揭示出的结合腔已用于一系列的维甲类化合物的DOCK研究。E-RABP的结合腔可做为设计新维甲类分子的模板。     

Proton spectroscopic imaging (Dixon method) of the liver: clinical utility

The contribution of proton spectroscopic (PS) imaging to magnetic resonance (MR) imaging of the liver was assessed at 0.5 T in 55 patients with known or suspected hepatic malignancy. PS images were compared subjectively with T1- and T2-weighted spin-echo (SE) images for hepatic lesion detection and conspicuity. For hepatic metastases (n = 27), PS images were equal to T1-weighted images in lesion detection in 17 patients but showed fewer lesions in five patients and false-negative results in two. When compared with T2-weighted images, PS images depicted more lesions in six patients, an equal number of lesions in 18, and fewer lesions in two. Hepatomas (n = 8) were detected with each sequence in all patients. Hepatomas were often more conspicuous on PS images than on T2-weighted images; they were of equal conspicuity on PS and T1-weighted images in most cases. Whereas fatty infiltration (n = 16) appeared on PS images as areas of low signal intensity similar to that of paraspinal muscle, it produced no detectable abnormality on either T1- or T2-weighted images. PS imaging is inferior to T1-weighted SE imaging in the detection of hepatic metastases. The major role of PS imaging at intermediate field strength is to differentiate focal fatty infiltration from hepatic metastases.     

Kissing osteochondromata leading to synostoses

Our aim was to determine the incidence of synostoses in the bones of the lower limbs in patients with multiple cartilaginous exostosis (MCE) and use the available imaging to suggest the cause and mechanism of its development. Radiographs of the lower legs of 21 patients with MCE were reviewed. With the intention of demonstrating the exact site and extent of synostoses and other bone deformities, such as bone pressure atrophy or erosions in five patients, 8 proximal and 6 distal tibiofibular joints were examined by CT scans. No synostoses were present in 11 patients and 10 patients had 1 to 4 synostoses. Of these synostoses, 14 were localized below the knee joint and 9 above the ankle joint. A growing osteochondroma arising from tibia or fibula can cause an erosion in the contagious surface of the neighbouring bone. If facing osteochondromata are present in both bones and show an interlocking growth at abutting parts, on osseous fusion can take place with formation of a synostosis in the proximal or distal tibiofibular joint region. In adult patients with MCE and abundant osteochondromata synostoses between the neighbouring bones of the lower legs are common findings; they are always caused by coalescence of “kissing” osteochondromata. Received 18 April 1996; Revision received 25 July 1996; Accepted 31 July 1996     

Shoulder joint: arthrographic CT and long-term follow-up, with surgical correlation

One hundred two computed tomographic (CT) arthrograms of the shoulder were retrospectively reviewed and compared with conventional double-contrast arthrograms from 101 patients (24 females and 77 males aged 9-70 years). One- to 4-year follow-up was obtained in 84 patients, 40 of whom underwent open-shoulder surgery or arthroscopy. Morphology of the normal portions of each labrum was categorized according to length, width, and tip shape. Correlation between morphology and age was weak, but abnormal labra were more common in younger patients. Conventional radiography was more accurate for detecting bony glenoid margin fractures, but CT was more accurate for detecting Hill-Sach fractures. CT was also more reliable than conventional arthrography in the detection of rotator cuff tears. Hence, few if any conventional radiographs are necessary between contrast material injection and CT imaging. A reduction in the number of images obtained will result in decreased radiation dose, less cost, and shorter examination time without loss of diagnostic accuracy.     

Adherent Cells as Targets in Mitogenic T-Lymphocyte Stimulation: Replacement of Lymphocyte-Bound Mitogens by Nonmitogenic Substances

The sequence of events in mitogenic T-lymphocyte activation was investigated by employing purified mouse peritoneal adherent cells and T-lymphocyte populations. After treatment of adherent cells with the oxidizing agents sodium periodate or neuraminidase plus galactose oxidase and removal of the mitogens, the cells acquired the ability to stimulate purified T-lymphocytes added subsequently. For this process of T-lymphocyte activation, the additional presence of the membrane interacting substances polyethylene glycol, dextran, nonmitogenic Helix pomatia agglutinin, or inactivated sendai virus was required. Lysates of mitogen-treated peritoneal adherent cells were able to replace the adherent cells in the cultures.     

Magnetic resonance imaging of the brainstem: normal structure and basic functional anatomy

Normal structure and basic functional anatomy of the brainstem were studied using anatomic sections obtained with a cryomicrotome whole-organ sectioning technique. Major tracts and nuclei were identified and their function summarized. Magnetic resonance imaging of the brainstem was performed on 10 normal volunteers. By comparing these images with the corresponding anatomic sections, normal structures, including major tracts and nuclei, were identified. Knowledge of location and function of clinically important brainstem nuclei and tracts is necessary for optimal magnetic resonance image interpretation.     

SEM observations on the mechanism of platelet release from megakaryocytes

Normal human bone marrow megakaryocytes were examined with the scanning electron microscope (SEM) to clarify the mechanism of platelet release. Several types of megakaryocytes were dtected according to their surface appearance, i.e. with wrinkles, ridges, villous formations, round blebs and cells with platelets still attached to the cell membrane. These observations are consistent with the concept that bleb formation is at least one of the mechanisms for platelet liberation.