Role of transforming growth factor beta in peritoneal fibrosis

SUMMARY: Technique survival of peritoneal dialysis is seriously limited by the development of peritoneal fibrosis. the mesothelial cell layer lining the peritoneum is important in the pathogenesis of peritoneal fibrosis. Mesothelial cells are able to produce transforming growth factor beta (TGF-β), and respond to stimulation by this cytokine. In this review, we will detail the evidence available so far for the role of the complex interaction between TGF-β and mesothelial cells in the development of peritoneal fibrosis.     

Pulmonary lymphangiomyomatosis: correlation of CT with radiographic and functional findings

In 14 patients with biopsy-proved lymphangiomyomatosis, disease extent at computed tomography (CT) was correlated with findings at chest radiography and pulmonary-function testing. The CT scans and chest radiographs were read independently by two chest radiologists. Disease extent was assessed on CT scans by using a visual score (0%-100% involvement of the lung parenchyma) and on radiographs by using an adaptation of the International Labour Office classification of the pneumoconioses. There was good concordance between the two observers for CT and radiographic scores (Kendall tau greater than or equal to .86, P less than .01). A significant but relatively low correlation was present between CT findings and radiographic severity of disease (r = .59, P less than .05). Impairment in gas exchange as assessed with the diffusing capacity correlated better with disease extent seen on CT scans (r = .69) than with chest radiographic findings (r = .59). Three patients had evidence of parenchymal disease on the CT scans but not on the radiographs. In one patient CT findings were negative despite a positive finding on chest radiographs. The authors conclude that CT is superior to chest radiography in the assessment of patients with lymphangiomyomatosis.     

Effect of methemoglobin formation on the MR appearance of subarachnoid hemorrhage

Subarachnoid hemorrhage has a much higher intensity in magnetic resonance (MR) images with the passage of time. Acute subarachnoid hemorrhage is difficult to see; within 1 week its appearance has become intensified on T1-weighted images. Different concentrations of blood and lysed red blood cells in cerebrospinal fluid (CSF) were examined spectroscopically but did not significantly alter T1 and T2 relaxation of CSF acutely. Ultraviolet visible spectroscopy of bloody CSF stored hypoxically for 3 days showed the presence of methemoglobin. The iron in methemoglobin is paramagnetic; in combination with water this facilitates T1 relaxation. It is concluded that methemoglobin formation with T1 shortening at least partially accounts for the increasing intensity of the MR appearance of subarachnoid hemorrhage over time in the central nervous system and may also explain the intense appearance of subacute hemorrhage in MR images elsewhere in the body.     

朝藿素D的分离和结构

从朝鲜淫羊藿(Epimedium koreanum)地上部分分离得到一新黄酮成分(I)和一已知化合物(II)。经光谱解析,证明I的结构为5,7,3',4'-tetrahydroxy-5'-prenylflavone,命名为朝藿素D(epimedokoreanin D);II为2-hydroxy-3,4,6,7-tetramethoxy-9,10-dihydrophenanthren。     

Leadership in the nursing unit: relationships with nurses' well-being

The head nurse occupies an important position in the nursing unit Concerning leadership style, a distinction is traditionally made between consideration and initiating structure Sometimes a third style is distinguished as well, namely 'production-orientated' leadership In a study of 561 nurses from 16 general hospitals in The Netherlands, the influence of two leadership styles upon the reactions of nurses (job satisfaction, experienced meaningfulness, health complaints and absenteeism) to their work situations was examined, namely the styles of social (i e consideration) and instrumental leadership (a combination of the styles initiating structure and production-onentated) The separate effects of the two styles were studied, as well as the connection between combinations of leadership styles and reactions The results indicate that social leadership contributes positively to nurses' reactions to their job Instrumental leadership, on the other hand, leads to health complaints From the analyses of combinations of leadership styles it appears that nurses are most satisfied if the head nurse pays much attention to both dimensions of leadership For health complaints, a tendency in this directions is also found Finally, it becomes clear that nurses with a great need for autonomy prefer a different type of leadership from nurses with little need for autonomy     

Platelet adhesion to collagen types I through VIII under conditions of stasis and flow is mediated by GPIa/IIa (alpha 2 beta 1-integrin)

Platelet adhesion to fibrillar collagens (types I, II, III, and V) and nonfibrillar collagens (types IV, VI, VII, and VIII) was investigated in the presence of physiologic concentrations of divalent cations under conditions of stasis and flow. Under static conditions, platelet adhesion was observed to collagen types I through VII but not to type VIII. Under flow conditions, platelet adhesion to collagen types I, II, III, and IV was almost independent of shear rates above 300/s. Collagen type V was nonadhesive. Platelet adhesion to collagen type VI was shear rate-dependent and optimal at a rate of 300/s. Collagen types VII and VIII showed minor reactivity and supported platelet adhesion only between shear rates 100 to 1,000/s. Monoclonal antibody (MoAb) 176D7, directed against platelet membrane glycoprotein Ia (GPIa; very late antigen [VLA]-alpha 2 subunit), completely inhibited platelet adhesion to all collagens tested, under conditions of both stasis and flow. Platelet adhesion to collagen type III at shear rate 1,600/s was only inhibited for 85%. The concentration of antibody required for complete inhibition of platelet adhesion was dependent on the shear rate and the reactivity of the collagen. An MoAb directed against GPIIa (VLA-beta subunit) partially inhibited platelet adhesion to collagen. These results show that GPIa-IIa is a major and universal platelet receptor for eight unique types of collagen.     

Anterior chest wall mass in an elderly male

A case of chondrosarcoma arising from the right anterior second rib in an 84-year-old man is described. Radiographic features include amorphous calcification within a chest wall mass. CT findings include calcification and necrosis within the 8 X 8 X 10 cm tumor, and extension into the adjacent lung. The presence of zones of dedifferentiation into fibrosarcoma in the surgically resected tumor indicates a poor prognosis, with a high likelihood of early recurrence and pulmonary metastasis.