Collagen type I of rat cortical and trabecular bone differs in the extent of posttranslational modifications

This study sought to evaluate whether the architecture of the matrix of cortical and trabecular bone is exactly the same. For this purpose we analyzed the extent of some posttranslational modifications of type I collagen, which is the major component of bone matrix. Ten female and 10 male 100-day-old rats were sacrificed and the content of hydroxylysine, glycosylated hydroxylysine, and pyridinium cross-links of collagen from cortical and trabecular bone was determined. The amount of each compound was expressed as a molar ratio with hydroxyproline. The collagen posttranslational modification pattern appears to be the same in both sexes but with a higher extent of differences in females compared with males. Comparing cortical and trabecular bone, the former contains a higher amount of hydroxylysine residues whereas in the latter, glycosylation of hydroxylysine is higher and pyridinium cross-link concentration is lower. Moreover, an inverse linear relationship between glycosylated hydroxylysine and pyridinium cross-links concentration was established, both for female (r =−0.455, P= 0.04) and male rats (r =−0.426; P= 0.06). This paper discusses what these findings may mean in functional terms. Received: 14 March 1995 / Accepted: 9 August 1995     

Synovial osteochondromatosis: the spectrum of imaging findings

Imaging plays a vital role in the diagnosis and management of synovial osteochondromatosis, a proliferative disorder of the synovium with associated loose body formation. The aim of this pictorial review is to illustrate the radiographic, computed tomographic and magnetic resonance appearances of various stages of the disease.     

Ablation of the cavotricuspid isthmus. Randomized prospective study of radiofrequency ablation with irrigated catheters versus standard catheters]

INTRODUCTION AND OBJECTIVES: An important limitation of the ablation with standard catheter is the volume and limited depth of the lesions created. The irrigated catheters, due to a larger and deeper lesion could be useful in patients with typical atrial flutter. The aim of this study was to prospectively compare the ablation procedure with an irrigated-tip catheter versus the standard catheter in this group of patients. METHODS: A total of 37 consecutive patients referred to ablation of the cavotricuspid isthmus for typical atrial flutter were randomized either to be performed by an standard catheter (20 patients with mean age of 62 18 years, 18 males) or an irrigated-tip catheter (17 patients with mean age 71 4 years, 13 males). RESULTS: With standard catheters, complete ablation of the cavotricuspid isthmus was achieved in 18 patients (90%). With a mean of 19 15 applications. With the irrigated-tip catheters the complete ablation of the isthmus was achieved with a mean of 8 7 applications (p < 0.001). Both mean duration of the procedure (164 56 versus 70 35 minutes) and fluoroscopic time (40 16 versus 16 8 minutes) was significantly less with irrigated catheters (p < 0.001). There were no significant clinical complications during the procedure nor later on. No patient presented ischemic symptoms nor alterations on the ST segment. CONCLUSIONS: The employment of irrigated-tip catheters achieved a high success rate with safety shortening the procedure time and radiation exposure.     

Enjeux psychiques du don de moelle osseuse

Organ transplantation development has imposed the elaboration of laws which apprehend and legitimate organ donation. The principal characteristic of bone marrow donation is a donation from living donors. Bone marrow donors are either related, and they are siblings, or unrelated. A review is proposed for understanding psychological issues of bone marrow donation to show the necessity of taking into account donors in this procedure.     

腹腔感染后白蛋白mRNA表达的变化及相关因素的影响

目的 :明确腹腔感染后低白蛋白血症的发生机理。　 方法 :以盲肠结扎穿孔的大鼠( CL P)为模型 ,观察 CL P后白蛋白 m RNA表达的变化 ,并通过多元回归和直线相关分析 ,了解激素、细胞因子和内毒素的影响。　 结果 :CL P后白蛋白 m RNA表达显著下降 ,并与血浆白蛋白水平的下降密切相关 ( r=0 .92 ,P<0 .0 1)。白蛋白 m RNA的变化与门脉血内毒素水平明显相关 ( r=- 0 .89,P<0 .0 1) ,而与血中胰岛素、胰高血糖素、胰高血糖素 /胰岛素比值、皮质醇、TNF、IL - 1和IL- 6浓度的变化无明显相关。　 结论 :1白蛋白 m RNA表达受抑是腹腔感染后低白蛋白血症的重要原因 ;2腹腔感染时 ,白蛋白 m RNA表达受抑与内毒素有关     

Characterization of transmitral flow using color-coded Doppler in a case of left atrial myxoma

The authors describe the transmitral flow pattern by color flow imaging in a patient with left atrial myxoma. The usefulness of color Doppler relays in the identification of the eccentric direction of transmitral flow, possibly present in such situation.     

Temporomandibular joint: MR assessment of rotational and sideways disk displacements

The accuracy of coronal and sagittal magnetic resonance (MR) imaging was examined in the assessment of rotational and sideways displacements of the temporomandibular joint (TMJ) disk. Rotational disk displacement implies a combination of anterior and medial or lateral displacements, whereas sideways displacement implies pure medial or lateral displacement without an anterior component. Multiple 3-mm-thick coronal and sagittal MR images were obtained of 18 fresh TMJ autopsy specimens and compared with the observations in corresponding coronal cryosections. MR imaging correctly delineated the mediolateral position of the disk in 15 joints (83%) and incorrectly delineated it in three joints (17%). Osseous anatomy was correctly assessed in 17 joints (94%). On cryosections, six joints (33%) showed medial disk displacement and two joints (11%) showed lateral displacement. In five of these eight joints the medial or lateral displacement occurred in conjunction with an anterior displacement, that is, rotational displacement. Clinical MR imaging in 37 patients (61 joints with coronal images) showed medial or lateral disk displacement in 16 joints (26%). This study suggests that rotational and sideways displacements of the TMJ disk are an important aspect of internal derangement. The multiplanar capabilities of MR are suitable for an assessment of these abnormalities.     

Chondroitin sulphate proteoglycan and embryonic brain enlargement in the chick

Previous studies of the early development of the neural tube have shown the existence of an intraneural fluid, which causes a positive pressure inside this primordium, and seems to play a key role in the early development of the central nervous system. In the present study we investigated the composition and synthesis of this intraneural fluid. By using a sequential method, which includes fixation with glutaraldehyde plus cetylpyridinium chloride, opening the neural cavity after critical point drying and scanning electron microscopy analysis, we found a water-soluble extracellular matrix that filled up the brain vesicles of chick embryos at the earliest stages of the neural tube. An ultrastructural study of the neural epithelium during these stages revealed the existence of a secretion process in the neural cells toward the apical side, the future neural cavity. An immunocytochemical study to asses the nature of the secreted material has shown that the intraneural matrix contains chondroitin sulphate proteoglycan, which appeared homogenously distributed throughout the neural cavity. Our findings demonstrate that the intraneural liquid is a fluid of complex composition and includes chondroitin sulphate proteoglycan as an osmotically active molecule. This suggests a morphogenetic role for the proteoglycan during early brain enlargement. The neural ectoderm is a polarized epithelium from early developmental stages and secretes the intraneural matrix.