Purified radiolabeled antithrombin III metabolism in three families with hereditary AT III deficiency: application of a three-compartment model

Purified human radioiodinated antithrombin III (125I-AT III) was used to study its metabolism in six members from three different families with a known hereditary AT III deficiency. Six healthy volunteers served as a control group. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and crossed immunoelectrophoresis (CIE) showed the purified AT III to be homogeneous. Amino acid analysis of the protein revealed a composition identical to a highly purified internal standard. The specific activity was 5.6 U/mg. Analysis of plasma radioactivity data was performed, using a three-compartment model. Neither plasma disappearance half-times nor fractional catabolic rate constants differed significantly between patients and control subjects. The mean absolute catabolic rate in the patient group was significantly lower than that of the control group at 2.57 +/- 0.44 and 4.46 +/- 0.80 mg/kg/day, respectively. In addition, the mean patient alpha 1-phase, flux ratio (k1,2 and k2,1) of the second compartment alpha 2-phase and influx (k3,1) of the third compartment were significantly reduced as compared with control values. It has been tentatively concluded that the observed reduction in the second compartment may be caused by a decrease in endothelial cell surface binding.     

Metabolic, membrane, and functional responses of human polymorphonuclear leukocytes to platelet-activating factor

The phospholipid mediator of anaphylaxis, platelet-activating factor (PAF) is chemotactic for polymorphonuclear leukocytes (PMN). We have examined this agent's effects on several other PMN functions. Human PMN were prepared from heparinized venous blood by Ficoll gradient. Metabolic burst was examined by measurement of O2 use and O2.- production in the presence or absence of PAF (10(-6)--10(-9) M). Unless cells were treated with cytochalasin-B (5 micrograms/ml), no significant respiratory burst was demonstrated. However, pretreatment with PAF (10(-7) M) enhanced approximately threefold the O2 utilization found when cells were subsequently stimulated with 10(-7) M FMLP. PAF also stimulated arachidonic acid metabolism in 14C-arachidonic acid- labeled PMN. Thin-layer chromatography analysis of chloroform-methanol extracts showed substances that comigrated with authentic 5- hydroxyeicosatetraenoic acid had a marked increase in radioactivity following PAF stimulation at 10(-7) M. PAF failed to stimulate release of granule enzymes, B-glucuronidase, lysozyme, or myeloperoxidase unless cytochalasin-B were added. PAF from 10(-6) M to 10(-10) M affected PMN surface responses. PMN labeled with the fluorescent dye, chlorotetracycline, showed decreased fluorescence upon addition of PAF, suggesting translocation of membrane-bound cations. Further, the rate of migration of PMN in an electric field was decreased following PAF exposure, a change consistent with reduced cell surface charge. PMN self-aggregation and adherence to endothelial cells were both influenced by PAF (10(-6) M--10(-9) M). Aggregation was markedly stimulated by the compound, and the percent PMN adhering to endothelial cell monolayers increased almost twofold in the presence of 10(-8) M PAF. Thus, PAF promotes a variety of PMN responses: enhances respiratory burst, stimulates arachidonic acid turnover, alters cell membrane cation content and surface charge, and promotes PMN self- aggregation as well as adherence to endothelial cells.     

Primary pulmonary mucinous adenocarcinoma in a 15-year-old boy.

Bronchogenic carcinomas are rare in childhood. Furthermore, mucinous (so-called colloid) adenocarcinoma, an unusual variant of pulmonary adenocarcinoma, is extremely rare in the first decade of life. To the best of our knowledge, we report the first case with primary pulmonary mucinous adenocarcinoma at the age of 15. Another interesting aspect of this tumor was its metastasis to thyroid, because metastasis of primary bronchogenic carcinomas to thyroid is uncommon. One can face up with difficulties in the establishment of the definite diagnosis due to its complex and often indistinguishable histopathologic pattern. In this paper we report a patient with pulmonary solid mass and thyroid nodule, initially diagnosed as metastatic thyroid carcinoma in whom postoperative resective surgery confirmed primary pulmonary mucinous adenocarcinoma with synchronous metastasis to thyroid.     

Comparison of biomechanical behaviour of maxilla following Le Fort I osteotomy with 2- versus 4-plate fixation using 3D-FEA: Part 3: Inferior and anterior repositioning surgery

Having studied the effect of maxillary advancement and maxillary impaction in parts 1 and 2 of this research, the purpose of this study was to investigate the biomechanical behavior of different fixation models in inferiorly and anteriorly repositioned maxilla following Le Fort I osteotomy. Two separate three-dimensional finite element models, simulating the inferiorly advanced maxilla at Le Fort I level, were used to compare 2- and 4-plate fixation. Model INF-2 resulted in 247 897 elements and 53 247 nodes and INF-4 consisted of 273 130 elements and 59 917 nodes. The stresses occurring in and around the bone and plate–screw complex were computed. The highest Von Mises stresses on the plates and maximum principal stresses on the bones were found in INF-2, especially under horizontal and oblique loads, when compared with INF-4. The present biomechanical study shows that the traditionally used 4-plate fixation technique, following Le Fort I inferior and anterior repositioning surgery, without bone grafting, provides fewer stress fields on the maxillary bones and fixation materials.     

PDGF受体、TGF-β1及其受体在视网膜下液中的表达

目的　了解视网膜下液中转化生长因子 - β1(T GF- β1)及其受体、血小板源性生长因子 (PDGF)受体的表达及与增生性玻璃体视网膜病变 (PVR )之间的关系。方法　采用 EL ISA和免疫组化技术分别对 3 7例和 3 3例伴有 PV R患者的视网膜下液进行检测。结果　 3 7例患者的视网膜下液 TG F-β1水平为 84 6.7ng· L- 1± 3 2 2 .6ng· L- 1,显著高于正常玻璃体 (3 77.78ng· L- 1± 87.2 9ng· L- 1) ,3 3例中的大多数标本可见 PDGFα(n=2 7)和β(n=2 0 )受体、TGF-β1受体 (n=2 3 )阳性表达细胞。结论　视网膜脱离伴 PV R患者视网膜下液的 PDGF、T GF-β1高表达提示 2个生长因子在 PVR发生中的作用 ,视网膜色素上皮细胞、神经节细胞可能是这 2个生长因子的靶细胞。