Combined Therapy of Radiofrequency Ablation and Ethanol Injection of Rabbit Liver: An <Emphasis Type="Italic">In Vivo</Emphasis> Feasibility Study

Our purpose was to compare the effects of percutaneous radiofrequency ablation (RFA) combined with percutaneous ethanol injection (PEI) on the extent of ablation in in vivo rabbit liver tissue as compared with either therapy alone. Twenty-two New Zealand white rabbits were included in this study and allocated into three groups: group A: conventional RFA (n = 6); group B: PEI (n = 6); group C: combined RFA and PEI (n = 10). For combined RFA and PEI, under ultrasound guidance, 1 mL of absolute ethanol was injected into the target area of the liver parenchyma through a 21-gauge Chiba needle before performing RFA. RFA was performed using a 17- gauge internally cooled electrode with 1-cm active tip, and RF energy (30 W) was applied for 3 minutes, with or without ethanol injection. After RFA or PEI, contrast-enhanced computed tomography and CT-pathologic correlation were performed. The short- axis and long-axis diameters of thermal lesions of each group were compared. All procedures were technically successful and a total of 38 lesions were produced. The mean short-axis and long-axis diameter of the coagulation necrosis in rabbits of group C (combination of RFA and PEI), were significantly larger than those of other groups: group A: 10.3 ± 2 mm and 11.4 ± 2 mm; group B: 3.1 ± 1 mm and 4.3 ± 2 mm; group C: 12.8 ± 3 mm and 17.8 ± 6 mm (p < 0.05). On contrast-enhanced CT scan, the lesions of rabbits of the group C appeared to be more frequently irregular compared to those of group A (20% in group A vs. 67% in group C). There were three complications including two localized hematomas and one cardiopulmonary failure. Combined RFA and PEI could increase the dimension of coagulation necrosis without increasing complications and therefore, may be successfully used for treating larger lesions.     

Acoustic radiation force impulse elastography of the liver: can fat deposition in the liver affect the measurement of liver stiffness?

Purpose  

The aim of this study was to compare acoustic radiation force impulse (ARFI) results between livers with and without fat deposition.     

Historical record and source apportionment of polycyclic aromatic hydrocarbons in the Lianhuan Lake sediments

Polycyclic aromatic hydrocarbons (PAHs) in a sediment core from the north Lianhuan Lake were collected to investigate its historical changes in the last one hundred years and its possible influence on ecological system in the lake. GC–MS was used to determine the concentrations of PAHs, and sediment chronological age was examined by ¹³⁷Cs dating approach. The concentrations of 16 different kinds of PAHs in the sediment samples ranged from 297 to 1,327 ng g⁻¹, and the low molecular weight (LMW) were predominant. The intensification of industrial and anthropogenic activities in the Daqing oil field may play the key role in the increase of PAHs concentrations in the late 1950s. To the early 1980s, the PAHs concentrations significantly decreased due to the grain size coarsening in the sediment samples, which was confirmed by the precipitation information. The 5–6 rings PAHs concentrations increased in the early 1980s may be attributed to the consumption of petroleum, coal and wood. The results showed that both the PAHs historical record and current concentrations may cause some influence on the Lianhuan Lake ecological system. The toxicology research on this ecological system should be done in the further investigations for determining the PAHs damage on human and ecological system health.     

Intra-specific variation in nitrate tolerance in tadpoles of the Natterjack toad

Anthropogenic sources of nitrogen that pollute bodies of water can have toxic and sub-lethal effects on amphibians. It has been hypothesized that such exposure may promote local adaptation, that is, selection for higher tolerance in individuals in populations exposed to pollutants. We tested this hypothesis with respect to the Natterjack toad (Bufo calamita Laurenti, 1768), by comparing the nitrate dose response of tadpoles from eight populations (doses: 0, 50, 100, 500 and 1000 mg/l nitrate) from relatively unpolluted and intensively farmed environments. We evaluated the effect of nitrate exposure by observing the behavior (movements) of tadpoles exposed to different concentrations of nitrates. Exposure to high nitrate levels did not cause tadpole mortality in the populations used in our experiments; however, we did observe changes in activity for all populations, with these changes being either dose-related responses (decreased activity after exposure to 500 or 1000 mg/l), or more complex responses (increased activity when exposed to 50 or 100 mg/l nitrate, followed by decreased activity at higher concentrations). Natterjack toad tadpoles exhibited variable behavioural responses among the tested populations. Although these populations were selected on the basis of their potential agrochemical contamination, the observed variation in population tolerance was not related to the parameters used to estimate this contamination in these breeding sites. Possible explanations for this apparent lack of local adaptation in B. calamita tadpoles include inadequate estimates of the toads’ actual nitrate exposure in the field, and the biological characteristics of B. calamita, which may limit the effects of exposure or favor phenotypic plasticity.     

The role of DTI in early detection of cervical spondylotic myelopathy: a preliminary study with 3-T MRI

Introduction  

The radiological diagnosis of cervical spondylotic myelopathy (CSM) has to be made as soon as possible, since surgery performed in earlier stages during the course of CSM was reported to be more successful when compared with later stages. We hypothesized that diffusion tensor imaging (DTI) may detect CSM in earlier stages, before the appearance of signal increase in T2-weighted sequences.     

Mitral valve replacement in children under 3 years of age

Objective: This study was undertaken to review our experience of mitral valve replacement in children under 3 years of age. Methods: Between January 1990 and May 2004,18 patients under 3 years of age underwent a total of 20 mitral valve replacements using a bileaflet mechanical prosthetic valve. There were 9 males and 11 females. The age at surgery ranged from 3 months to 3 (mean=1.02±0.72) years and body weight varied between 3.4 and 13.2 (mean=7.08±2.74) kg. Results: There were 4 early and 2 late deaths, and these occurred in severe cases aged less than 1 year of age. Re-replacement of mitral valve was required in 3 patients (valve thrombosis in 2 and pannnus formation in 1). Orifice size of the implanted prosthesis (OS) as compared with the predicted normal size of the mitral valve (NS) was well correlated with maximum transprosthetic flow velocity estimated by Doppler echocardiography. In this study, the OS/NS>0.65 was maintained in all patients, and none required re-replacement because of prosthesis-patient mismatch. Conclusion: Patients less than 1 year of age had significant mortality and morbidity. The results were satisfactory in the remainder (1–3 years). During this follow-up period, none required re-replacement due to somatic growth, but it will be an unavoidable problem in the future. The OS/NS, which can be checked with a regular physical examination, may serve as a guide to determine the most appropriate timing for the second surgery.     

New Insights into Molecular Pathogenesis of Bone Marrow Failure in Paroxysmal Nocturnal Hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is caused by the clonal expansion of hematopoietic stem cells with mutations of the phosphatidylinositol glycan-class A gene (PIGA). PNH clones then fail to generate glycosylphosphatidylinositol (GPI) or to express a series of GPI-linked membrane proteins including complement-regulatory proteins, resulting in complement-mediated intravascular hemolysis and thrombosis. Bone marrow failure is another characteristic feature of PNH. It is currently considered that immune-mediated injury of hematopoietic cells is implicated in PNH marrow failure as well as in aplastic anemia, a well-known PNH-related disorder. There is increasing evidence that the autoimmune attack allows PNH clones to selectively survive in the injured marrow, leading to clinical manifestations characteristic of PNH. As candidate molecules that trigger the immune attack on marrow cells, stress-inducible membrane proteins and Wilms’ tumor protein WT1 have been proposed. Among the stress-inducible proteins, GPI-linked proteins, such as cytomegalovirus glycoprotein UL16-binding protein, are distinct candidates that not only induce immune attack, but also allow PNH clones to survive the attack. Here, we overview the current understanding of the molecular pathogenesis of bone marrow failure in PNH.     

Primary epithelioid sarcoma of the vulva in pregnancy

Primary epithelioid sarcoma (ES) of the vulva is an extremely rare tumor, and to date, only 20 cases have been reported. We report the second case of vulvar ES presenting in pregnancy. A 25-year-old woman, at 6 weeks of gestation, was diagnosed as having vulvar sarcoma and was referred to our hospital. Immunohistochemical studies revealed that the tumor cells were positive for cytokeratin, epithelial membrane antigen (EMA), and wimentin. The tumor cells did not stain for S-100, SMA, HMB-45, desmin, LCA, CD-34, or estrogen and progesterone receptors. The tumor showed diffuse and strong staining for CD-117 (c-kit). After the curettage, she underwent local wide excision and left inguinal lymph node dissection and received external-beam radiation therapy. At 16 months of follow-up the patient was well without any disease recurrence. The appropriate treatment of vulvar ES is not clear, and the role of chemotherapy is disappointing; however, it might be worth investigating the role of Imatinib in c-kit overexpressing vulvar ES.