Accelerated 3D echo-planar spectroscopic imaging at 4 Tesla using modified blipped phase-encoding.

Whole-brain echo-planar spectroscopic imaging (EPSI) often substantially lengthens MRI/MRSI (magnetic resonance spectroscopic imaging) protocols. To halve acquisition time, application of a blipped phase-encoding (PE) gradient during the EPSI readout (RO) was previously suggested by PE of the even RO echoes in k-space at an interstitial location along k(PE), separated from the odd RO echoes, effectively reducing the number of PEs by a factor of 2. However, the approach is very susceptible to phase inconsistencies between even and odd RO echoes in the presence of B(0) inhomogeneities and gradient imbalance, leading to ghosting in the PE direction. In this work, the blipped PE gradient is placed in between pairs of even/odd RO gradient lobes to avoid these problems. This approach is demonstrated in a phantom and in normal human brain in vivo at 4T. While the proposed method allows substantial reduction in metabolite ghosting, it may be limited by the presence of a relatively large spurious signal at the Nyquist frequency.     

电视硬质气管镜治疗大气道良性肿瘤

目的探讨电视硬质气管镜在大气道良性肿瘤治疗中的价值.方法2002年9月～2005年4月,我院应用电视硬质气管镜治疗大气道良性肿瘤7例,其中气管1例,隆突1例,左主支气管3例,右主支气管2例.手术采用静脉全身麻醉,喷射通气供氧,探查评估气道后,首先冷冻或电凝肿瘤,破坏肿瘤血供,再以活检钳分块取出,蒂部采用冷冻或氩气凝固处理;对于宽蒂肿瘤,内镜下将肿瘤主体清除后中转开胸行气管局部切除吻合术.结果7例手术均顺利,无一例死亡和严重并发症发生.6例气管窄蒂良性肿瘤镜下完整摘除,1例气管膜部宽蒂平滑肌瘤先内镜清除肿瘤主体后中转开胸行气管局部切除.术后病理为错构瘤2例,平滑肌瘤3例,嗜酸性肉芽肿性腺瘤1例,炎症组织1例.7例随访3～36个月,平均17.3月,无肿瘤复发.结论电视硬质气管镜治疗大气道良性肿瘤安全可靠.     

Conventional 4-field box radiotherapy technique for cancer cervix: potential for geographic miss without CECT scan-based planning

BACKGROUND: The advantage of 4-field radiation to the pelvis is that the use of lateral portals spares a portion of the small bowel anteriorly and rectum posteriorly. The standard lateral portals defined in textbooks are not always adequate especially in advanced cancer cervix. METHODS: An analysis was done to determine adequacy of margins of standard lateral pelvic portals with CECT defined tumor volumes. The study included 40 patients of FIGO stage IIB and IIIB treated definitively for cancer cervix between 1998 and 2000. An inadequate margin was defined if the cervical growth and uterus were not encompassed by the 95% isodose. RESULTS: An inadequate posterior margin was common with bulky disease (P = 0.06) and with retroverted uterus (P = 0.08). Menopausal status, FIGO stage, associated myoma, and age were of no apparent prognostic significance. Bulk retained significant on multivariate analysis. An inadequate anterior margin was common in premenopausal (P = 0.01); anteverted uterus (P = 0.02); associated myoma (P = 0.01); and younger patients (P = 0.03). It was not influenced by bulk or stage. Menopausal status and associated myoma retained significant on multivariate analysis. CONCLUSION: Without the knowledge of precise tumor volume, the 4-field technique with standard portals is potentially risky as it may under dose the tumor through lateral portals and the standard AP/ PA portals are a safer option.     

Cerebral Cortical Aquaporin-4 Expression in Brain Edema following Cardiac Arrest in Rats

OBJECTIVES: Brain edema occurs following clinical as well as experimental cardiac arrest (CA) and predicts a poor neurologic outcome. The objective of this study was to determine the expression of cerebral cortex aquaporin (AQP)-4, a member of a family of membrane water-channel proteins, in brain edema formation following normothermic or hypothermic CA. METHODS: Twenty-four rats were subjected to time-matched normothermic (N-Sham, 37.5 degrees C +/- 0.5 degrees C, n = 6) or hypothermic (H-Sham, 34 degrees C +/- 0.5 degrees C, n = 6) sham experiments and normothermic (N-CA, n = 6) or hypothermic (H-CA, n = 6) CA induced by asphyxiation for 8 minutes. Hypothermia was induced before CA. The animals were resuscitated with cardiopulmonary resuscitation, ventilation, and epinephrine administration. Brain edema was determined by brain wet-to-dry weight ratio at one hour of resuscitation. AQP4 immunoactivity in the cerebral cortex was determined using immunohistochemical staining and was semiquantified as an intensity of staining with an automated cell imaging system. RESULTS: Mild hypothermia in the sham experiments did not alter cerebral cortex AQP4 immunoactivity (mean +/- SD) (55.0 +/- 3.7 in H-Sham vs. 53.3 +/- 1.7 in N-Sham, p > 0.05). N-CA resulted in a significant increase in AQP4 immunoactivity (61.8 +/- 4.5) compared with N-Sham (p = 0.01) and H-Sham (p = 0.03). H-CA attenuated AQP4 compared with N-CA (53.4 +/- 1.3, p = 0.01). Brain wet-to-dry weight ratios were 4.41 +/- 0.07 in N-Sham, 4.40 +/- 0.08 in H-Sham (p > 0.05 vs. N-Sham), 4.55 +/- 0.04 in N-CA (p = 0.004 vs. N-Sham; p = 0.005 vs. H-Sham), and 4.43 +/- 0.09 in H-CA (p = 0.02 vs. N-CA; p > 0.05 vs. N-Sham and H-Sham). CONCLUSIONS: Cerebral cortical AQP4 expression is up-regulated after normothermic CA, which is attenuated by hypothermia induced before CA.     

Fas/Apo-1在下肢静脉性溃疡的表达

目的 探讨Fas/Apo-1(CD95)在下肢静脉性溃疡的表达及意义.方法 采用流式细胞技术、半定量逆转录-聚合酶链反应(RT-PCR)和免疫组织化学方法检测不同体位下肢外周血和局部皮肤Fas/Apo-l(CD95)的表达.结果 溃疡组平卧位、下垂位血液中Fas/Apo-1(CD95)阳性细胞数分别为41.45±14.25、40.20±12.42,mRNA为0.74±0.33、0.78±0.22,皮肤中阳性细胞数为42.62±22.19、46.50±20.12,分别与无溃疡组和对照组比较,差异均有统计学意义(P<0.05);无溃疡组和对照组比较,差异无统计学意义(P>0.05);不同体位之间Fas/Apo-1(CD95)阳性细胞数和含量比较,差异无统计学意义(P>0.05).结论 Fas/Apo-1高表达可能与下肢静脉性溃疡发生密切相关.     

CD24 expression on human keratinocytes

Abstract: CD24 or Nectadrin is a cell surface glycoprotein expressed in pre-B lymphocytes, T lymphocytes, neurons, muscle cells and carcinoma cells. Its function is not completely known, but it has been suggested that it is involved in cell adhesion and signalling. CD24 has recently been identified as the human molecule homologous to the murine heat-stable antigen (HSA). HSA is expressed by murine keratinocytes and delivers costimulatory signals in T-cell activation. Long-term cultures of normal human keratinocytes (HKC) were obtained from skin of human female breast sections and either left untreated or were treated with phorbol-12-myristate-13-acetate (PMA) at 10–100 ng/ml, calcium 0.5–2 mM or IFN-γ 100–1000 U/ml, for 24–48 h. Using RT-PCR and flow cytometry we showed that HKC express low levels of CD24 even under basal conditions, and the treatment with calcium, PMA or IFN-γ increased levels of CD24 mRNA and protein. To the best of our knowledge, this is the first report to measure CD24 expression and production by cultured HKC in basal conditions and after stimulation. Further studies are needed to determine biological and therapeutical relevance of these findings.     

Cardiovascular effects of Leu-enkephalin in the nucleus tractus solitarius of the rat

Microinjections of Leu-enkephalin into the dorsal vagal complex induced hypotension and bradycardia. Both naloxone, given at a dose conferring selectivity for μ receptors, and the S antagonist ICI 154,129 prevented the cardiovascular effects of Leu-enkephalin. Naloxone was also found to decrease the gain of the baroreflex. These results suggest that Leu-enkephalin is involved in cardiovascular regulation through activation of δ-, and possibly μ-, opioid receptors in the dorsal vagal complex.     

Abnormal cardiac histology in severe intrauterine growth retardation infants

Four infants with severe intrauterine growth retardation (IUGR) weighing less than 1000 g at birth developed heart failure and died in our unit, where heart failure of IUGR infants is the main reason of death in extremely low birth-weight infants. The causes of their heart failure are one of the main themes in current neonatal medicine. The subjects of this study were four small for gestational age infants; all died due to heart failure 5 to 10 days after birth. Microscopic specimens of hearts from autopsies were evaluated with respect to the following characteristics: thickness of myocardial fibers, maturation of nuclei, presence of dysgenesis or necrosis in myocardium, and amount of glycogen in the heart. Neither dysgenesis nor infarction of the heart was found but hypoplasia in myocardial fibers and decreased glycogen levels were observed. Maturation delay in myocytes' nuclei did not appear to be severe. We conclude that these infants' hearts failed to adapt to postnatal hemodynamic changes because of inadequate myocardial function and inadequate glycogen reserves.     

聚对苯乙炔（PPV）及其衍生物的研究进展

评价了ＰＰＶ系列衍生物的电学性质、非线性光学性质及其应用。     

The effectiveness of intermittent isotretinoin treatment in mild or moderate acne

BACKGROUND: Isotretinoin is the only drug that affects almost all factors in acne pathogenesis. Recently, its use for the treatment of chronic mild or moderate acne unresponsive to long-term antibiotic therapy, and with a tendency to cause scarring and leading to negative psychological effects, has became popular. The aim of the study was to investigate the effectiveness of intermittent isotretinoin treatment in mild or moderate acne. METHODS: Sixty patients with mild or moderate acne localized to the face were enrolled in the study. The treatment regimen consisted of isotretinoin, 0.5-0.75 mg/kg per day, applied for 1 week every 4 weeks for a total period of 6 months, according to the degree of acne and number of inflammatory lesions. RESULTS: Forty-one (68.3%) of the 60 patients completed the 6-month therapy. At the end of the treatment complete improvement was observed in 34 patients (82.9%) out of 41. All adverse effects were mild and discontinuation of the treatment was not necessary. CONCLUSION: Intermittent isotretinoin treatment was found to be a safe and effective choice for patients with mild or moderate acne.