神经纤维瘤病I型的MRI研究

目的：回顾神经纤维瘤病I型（NF1）患者MRI表现，分析MR扫描序列及其诊断价值，以建立合适的MR成像方案，为NF1影像诊断提供有价值的依据。方法：对30例临床确诊为NF1患者采用本组MR成像方案进行扫描，主要包括：轴面SE序列T2WI；平扫矢状面SE脉冲序列T1WI；增强轴面或矢状面SE脉冲序列T1WI；轴面或冠状面液体衰减反转恢复（FLAIR）序列，同时分析病变的发病部位、数目、形态、信号的变化和病变的强化情况等。结果：MRI可见下列3种表现：（1）多发性脑内错构瘤：30例中25例在SE脉冲序列T2WI和FlAIR脉冲序列见高信号病灶，病灶主要位于苍白球、小脑和脑干。另外，25例中20例可见海马回、海马旁回等区晕状高信号改变。（2）视通道或下丘脑胶质瘤：视神经、视交叉增粗、扭曲；视交叉或下丘脑肿块，SE脉冲序列T2WI和FlAIR序列表现为不规则分叶状混杂信号肿块，在增强SE脉冲序列T1WI有明显不规则强化。（3）脊柱多发性神经纤维瘤：SE脉冲序列T2WI和脂肪抑制短时反转恢复（STIR）序列显示高信号沿脊神经分布的多发性肿瘤。结论：MRI能够作为1种 常规的影像检查方法对NF1患者进行诊断和追踪。本组MR成像方案能较好地显示NF1的多发性或多灶性病变。     

Acid phosphatase activity in mononuclear phagocytes and the U937 cell line: monocyte-derived macrophages express tartrate-resistant acid phosphatase

Tartrate-resistant acid phosphatase (TRAcP) is used as a marker for osteoclasts, which are believed to be derived from phagocytic cells or phagocyte stem cell precursors. To further investigate the relationship between monocytic phagocytes and osteoclasts, acid phosphatase (AcP) activity was measured by three different techniques in human peripheral blood monocytes, monocyte-derived macrophages, and the U937 cell line. We found that cytochemistry and gel electrophoresis led to similar results, but that the colorimetric assay was inconsistent. Normal human peripheral monocytes expressed both tartrate-sensitive and -resistant AcP. In culture these cells formed polykaryons and expressed TRAcP activity that was further identified as an isoenzyme associated with bone tissue. In contrast, the U937 cells did not express TRAcP activity as measured by gel electrophoresis. Both U937 cells and monocytes possess material that interferes with interpretation of the colorimetric assay of AcP. The presence of TRAcP in monocyte-derived macrophages further supports the relationship between phagocytic cells and bone osteoclasts.     

Membrane-disorganizing property of polymyxin B nonapeptide

The possibility of improving the antibacterial activities of drugs normally excluded by Gram-negative bacteria with polymyxin B nonapeptide (PMBN) has been explored. In vitro, PMBN rendered clindamycin, erythromycin, novobiocin, rifampicin and vancomycin very active against a number of Gram-negative enteric bacteria. The drug also sensitized the previously resistant bacterial strains to human, mouse or guinea pig serum. However, parenterally administered PMBN failed to influence bacterial growth in chambers implanted into mice and guinea pigs. It was also ineffective in experimental septicaemia at a dose of up to 200 mg/kg or when combined with antibiotics with which it interacted synergistically in vitro.     

Influence of overweight and obesity on physician costs in adolescents and adults in Ontario, Canada

The study purpose was to perform an obesity cost-of-illness analysis for individuals living in the province of Ontario, Canada. The participants consisted of a representative sample of 25 038 adults and 2440 adolescents (aged 12–17 years) who participated in the 2000/2001 Canadian Community Health Survey (CCHS). The CCHS data set includes measures of body mass index (BMI) (classified as normal weight, overweight or obese) and relevant covariates (age, income, smoking, alcohol, physical activity). The CCHS data set was linked to the Ontario Health Insurance Plan providers' database to obtain physician costs for 2002–2003. A two-part modelling approach was used to calculate and compare the average annual physician cost according to BMI. After adjusting for the covariates, physician costs were not significantly higher in overweight men and women compared with those with a normal weight. Physician costs were 14.7% higher in obese men and 18.2% higher in obese women than in men and women with a normal weight. Average physician costs were comparable in normal-weight and overweight/obese adolescents ($233 per year in both groups). Because Ontario operates a publicly funded healthcare system, the findings of this study have relevance for other provinces/states and countries that operate similar healthcare systems.     

Subcranial anterior skull base dural repair with galeal frontalis flap.

The pericranial flap has been widely used to repair surgically created anterior skull base defects during craniofacial resection. This report describes a technique of subcranial dural repair with a galeal frontalis flap after resection of an ethmoidal adenoid cystic carcinoma.     

Pion therapy at TRIUMF. Treatment results for astrocytoma grades 3 and 4: a pilot study

At TRIUMF, (located on the University of B.C. Campus), 53 patients with supratentorial astrocytoma grades 3 and 4 were treated with pions between 1982 and 1985. A 3-dimensional spot-scanning treatment technique has proven to be practical. The accuracy of the beam alignment system used for treatment was reproducible daily within 2 mm. Low pion flux has hindered optimal beam shaping but this will soon be remedied as flux improves. The overall median survival observed (53 patients) is 262 days from date of first radiation treatment. Younger (less than 49 years) patients have significantly better survival than older (greater than 50 years) patients (p = 0.001). From a base line dose of 40 Gy photons whole brain and 17.5 Gy pion boost, doses were escalated to 33 Gy pions localised to the primary tumour and the median survival improved from 198 to 436 days. Survival curves for patients treated with localised pion techniques to doses above 30 Gy are significantly better than for those treated with schedules of pions mixed with photons (p = 0.04). It appears that optimal pion dose for brain tumours is 33 Gy minimum with a possible maximum of 36 Gy and doses delivered in 15 fractions in 3 weeks. Requirements for future trials are discussed.     

Inhibition of carrageenan induced inflammation in the rat knee joint by substance P antagonist.

The pathophysiology of acute joint inflammation remains unclear. Evidence is available to suggest a neurally mediated component to the inflammatory process. Acute joint inflammation in the rat knee, induced by intra-articular injection of 2% carrageenan, was reduced by 44% in animals whose knee had previously been injected with 1% capsaicin, while chronic joint denervation produced a 37% reduction. These results indicate a significant neurogenic component in this model of acute joint inflammation. Substance P may be the mediator of this response as intra-articular injection of this agent provoked an acute inflammatory response. Pretreatment of the test knee with the substance P antagonist d-Pro4,d-Trp7 9 10-SP(4-11), however, resulted in a 93% reduction of the inflammatory response to carrageenan. This unexpectedly large effect suggests that this substance P antagonist blocks both neurogenic and non-neurogenic mediators of inflammation. Sympathetic efferent fibres innervating the knee joint were not found to contribute to the neurogenic component of the inflammatory process.     

In vivo use of a radioiodinated somatostatin analogue: dynamics, metabolism, and binding to somatostatin receptor-positive tumors in man.

Somatostatin analogues, labeled with gamma-emitting radionuclides, are of potential value in the localization of somatostatin receptor-positive tumors with gamma camera imaging. We investigated the application in man of a radioiodinated analogue of somatostatin, 123I-Tyr-3-octreotide, which has similar biologic characteristics as the native peptide. The radiopharmaceutical is cleared rapidly from the circulation (up to 85% of the dose after 10 min) mainly by the liver. Liver radioactivity is rapidly excreted into the biliary system. Until 3 hr after injection, radioactivity in the circulation is mainly in the form of 123I-Tyr-3-octreotide. Thereafter, plasma samples contain increasing proportions of free iodide. Similarly, during the first hours after injection, radioactivity in the urine exists mainly in the form of the unchanged peptide. Thereafter, a progressive increase in radioiodide excretion is observed, indicating degradation of the radiopharmaceutical in vivo. Fecal excretion of radioactivity amounts to only a few percent of the dose. The calculated median effective dose equivalent is comparable with values for applications of other 123I-radiopharmaceuticals (0.019 mSv/MBq).