MRI在膝关节损伤诊断中的应用价值

目的:通过膝关节损伤MRI影像的分析,确定其诊断价值及意义。材料和方法:本文收集了自1992年以来我院所检查的42例膝关节损伤患者,52个膝关节成像。其中男性34人;女性8人,各年龄组以30～40岁组最多。损伤以前交叉韧带和外侧半月板损伤者多见,分别占总损伤数的20％及30％。损伤又以左膝多见,占总数的61％。结果:MRI能较明确地显示膝关节的半月板、关节软骨、韧带、滑膜及骨质的改变,明显地比CT所能看到的层次多,对软组织的损伤显示清晰。结论:只要正确地应用不同序列及切层方向、厚度等技术,可清晰地显示其信号特征,从而能确定其损伤部位、程度。     

Expression and activation of 15-lipoxygenase pathway in severe asthma: relationship to eosinophilic phenotype and collagen deposition

BACKGROUND: Although 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE), a product of 15-lipoxygenase (15-LO), may be involved in mild to moderate asthma, little is known about its potential roles in severe asthma. OBJECTIVES: This study was performed to evaluate 15(S)-HETE levels in bronchoalveolar lavage fluid (BALF) from severe asthmatics with and without airway eosinophils and from the control groups. In addition, 15-LO protein expression was examined in endobronchial biopsy, while its expression and activation were evaluated in BAL cells. RESULTS: While 15(S)-HETE levels in BALF were significantly higher in all severe asthmatics than normal subjects, severe asthmatics with airway eosinophils had the highest levels compared with mild, moderate asthmatics and normal subjects. 15(S)-HETE levels were associated with tissue eosinophil numbers, sub-basement membrane thickness and BALF tissue inhibitor of metalloproteinase-1 levels, and were accompanied by increased 15-LO expression in bronchial epithelium. In addition, activation of 15-LO was suggested by the increased proportion of 15-LO in the cytoplasmic membrane of alveolar macrophages from severe asthmatics. CONCLUSION: The data suggest that severe asthmatics with persistent airway eosinophils manifest high levels of 15(S)-HETE in BALF, which may be associated with airway fibrosis. It is likely that 15-LO expression and activation by airway cells explain the increased 15(S)-HETE levels.     

Diagnosis in Prader-Willi syndrome.

Thirty one patients with the putative diagnosis of Prader-Willi syndrome were reassessed clinically and by DNA analysis. Eleven patients were judged not to have Prader-Willi syndrome and 20 to have the condition. This was confirmed by DNA analysis in all but one case. The diagnosis of Prader-Willi syndrome, especially in early infancy, should be made with caution unless confirmed by molecular genetic studies.     

Staging patterns and early cancer detection.

There is a great deal of indirect, nonexperimental evidence that a pattern of earlier-stage disease at diagnosis has a better outcome. Increased early detection activities can change, these stage patterns while various biases and the question of generalizability need to be kept in mind in their interpretation. The indirect evidences of possible benefit from early detection activities includes an increase in the number of cases detected, a pattern of more early- and less advanced-stage cases, an increase in the overall site-specific survival rate, and a decrease in the case fatality rate. Unless these intermediate markers are favorable, it is unlikely that early detection will reduce mortality. In addition, one should also differentiate a reduced incidence or a change in treatment as a cause for reduced mortality.     

In vivo evidence that ethosuximide is a substrate for cytochrome P450IIIA.

The role of various subfamilies of rat hepatic cytochrome P450 in the oxidation of ethosuximide was evaluated by comparing ethosuximide clearance in control rats and those pretreated with relatively selective P450 inducers and/or inhibitors. Clotrimazole pretreatment increased ethosuximide clearance threefold (p less than 0.005). Dexamethasone increased ethosuximide clearance twofold (p less than 0.001), and the dexamethasone effect was completely abolished by a single dose of triacetyloleandomycin. These results suggest a prominent role for cytochrome P450IIIA in ethosuximide metabolism in the rat. Isoniazid increased ethosuximide clearance twofold (p less than 0.001), and this effect was abolished by a single dose of diallylsulfide, suggesting that ethosuximide is also processed by cytochrome P450IIE1 in rats. Phenobarbital pretreatment increased ethosuximide clearance 2-2.7 fold (p less than 0.001); an effect that was only partially reversed by orphenadrine, an inhibitor of cytochrome P450IIB/IIC enzymes. This suggests a quantitatively less important role for the IIB/IIC subfamilies in processing ethosuximide, since phenobarbital is an inducer of P450 subfamilies IIB, IIC, IIE, and IIIA. Neither the cytochrome P450IA inducer, beta-naphthoflavone, nor the inhibitor, alpha-naphthoflavone altered ethosuximide clearance. Ajmaline, an inhibitor of cytochrome P450IID, had no effect on ethosuximide clearance. Together, these findings suggest that ethosuximide is principally oxidized by cytochrome P450IIIA, and that cytochrome P450IIE may play an important role. Cytochromes P450IIB/C play less prominent roles in ethosuximide oxidation, and neither cytochrome P450IA nor cytochrome P450IID is involved.     

Short-term dermal toxicity and mutagenicity of coal coprocessing products in the rat.

The present study was conducted to determine the dermal toxicity of coal coprocessing products and to assess their potential health hazards. Groups of 10 male and 10 female Sprague-Dawley rats were administered dermally coal coprocessing products (light gas oil, LGO; heavy gas oil I, HGOI; heavy gas oil II, HGOII) at 1 g/kg body weight/d for 14 d. The control and positive control groups received normal saline and a coal liquefaction product (CLP) at the same dose level, respectively. Treatment with either the three fractions of coprocessing products or CLP caused decreased growth rate and food consumption in animals of both sexes. Liver enlargement occurred in groups treated with HGOI, HGOII, and CLP. Decreased serum glucose was observed in animals of both sexes treated with the three fractions and CLP. Treatment with HGOI and CLP caused an elevation of hepatic microsomal ethoxyresorufin deethylase activity in the rat of both sexes. The three fractions and CLP caused mild anemia. Mild treatment-related histological changes were observed in the liver, spleen, thyroid, bone marrow, and kidney. All three fractions of coprocessing products were tested for their mutagenicity in five strains of Salmonella typhimurium: TA98, TA100, TA1535, TA1537, and TA1538. HGOI, after metabolic activation, was found to be mutagenic in the strains of TA98, TA100, and TA1538. In contrast, HGOII was mutagenic in the five strains with or without metabolic activation. These data indicate that HGOI and HGOII are more toxic than LGO, and should be subjected to further studies to determine their long-term effects.     

甲状腺肿瘤X线造影与超声检查对比分析

本文报告了经手术病理证实的53例甲状腺肿瘤,均作了甲状腺造影和B超检查.通过比较分析,我们认为造影对确定肿瘤的良、恶性以及延伸到胸骨后的异位甲状腺肿瘤有其优越性,是一项有效的检查方法;超声则能准确地判断肿瘤的囊、实性,适合碘过敏患者的检查.两种检查各有特点,配合使用有利于对甲状腺肿瘤的诊断和治疗.     

Intracellular pH regulation by a Na+/H+ exchanger in cultured bovine trabecular cells.

Intracellular pH (pHi) of cultured bovine trabecular cells was measured using video-imaging techniques with a pH-sensitive intracellular fluorescent dye, BCECF. In bicarbonate-rich Ringer at pH 7.4, pHi was 7.29 +/- 0.03 (+/- SEM, n = 12 monolayers, 120 cells sampled). Exposure to 20 mM NH4Cl immediately alkalinized pHi: replacement with a Na(+)-rich solution acidified pHi before recovery to resting levels. When NH4Cl was replaced by a low Na+ solution, acidification was sustained but pHi recovery occurred after Na(+)-rich solution. A pHi of 7.11 +/- 0.02 (n = 2 monolayers, 20 cells) occurred in pH 6.8 and pHi was 7.72 +/- 0.03 (n = 2 monolayers, 20 cells) in pH 8.0. Amiloride (1 mM) acidified pHi but DIDS (1 mM) treatment, HCO3(-)-free condition, 1 mM ouabain, 50 mM K+, and 2 mM BaCl2 failed to change pHi. Hydrogen peroxide (1 mM) acidified pHi but no change occurred with 50 microM. Trabecular cells possess an Na+/H+ exchanger similar to that in other cell types.