PET-CT在非完全实性肺结节中的应用价值

肺癌在中国恶性肿瘤的发病率位居第一,随着低剂量薄层CT在肺癌筛查中的广泛应用,临床发现更多表现为非完全实性结节的肺腺癌,目前众多研究使CT影像学特征和肺腺癌病理的关系得到更进一步的认知,虽然CT能对部分非完全实性结节做出定性和定位诊断,但仍有部分非完全实性结节诊断困难,PET-CT结合了病灶的代谢信息和精确的定位信息,从而提高对肺部结节诊断的敏感性、特异性、准确性,综合多个文献PET-CT在非完全实性结节中的诊断分期价值较CT无明显提升,却在评估预后和制定合适手术方案上可以起到一定的作用,本文就PET-CT在SSN中的应用价值进行阐述。     

烟青虫感染核型多角体病毒后围食膜的病变

昆虫的围食膜是衬在昆虫中肠内一种网状的结构,它可充作虫体抵御外来病原侵染的一道屏障。关于鳞翅目昆虫幼虫感染了昆虫病毒后围食膜的病变问题,国内外鲜有报道。尤锡镇和康慧娟(1985)曾以实验证明家蚕围食膜对核型多角体病毒有灭活作用,而且认为核型多角体病毒不能侵染和破坏围食膜。Derksen和Granados(1988)则证明染病幼虫的围食膜因不同杆状病毒(包括两种核型多角体病     

A Novel Zeolite Coating for Protection of Concrete Sewers from Biological Sulfuric Acid Attack

Microbial growth inhibition and resistance to biological deterioration of concrete specimens coated with silver-loaded zeolite was evaluated by measuring the time course of bacterial growth, biological sulfur oxidation, and sulfate production using Acidithiobacillus thiooxidans as a corrosive agent. Live bacterial cells declined from an initial inoculum concentration of 1.1 × 10₄ cell ml_-1 to zero in 10 days, during which only 0.5–1% of the initial sulfur concentration of 10 g l_-1 was biologically oxidized, corresponding to sulfate production rates of 35–42 mg SO ₄ ^{2 ?} g ^{? 1} S ^{? 1} . Leaching coefficients of calcium and silicon in the specimens coated with silver-loaded zeolite of 1.6 × 10 ^{? 4} to 4.6 × 10 ^{? 2} cm ² d ^{? 1} respectively, were only 0.8% and 1% of the uncoated specimens.     

Somatoform disorders among patients attending walk-in clinics in Trinidad: prevalence and association with depression and anxiety

Objectives Somatoform disorders are common in international primary care settings, but have been little studied in the developing world. The objective of this study was to determine the prevalence of severe undifferentiated somatoform disorder, and its relationship to depression and anxiety, among patients attending walk-in clinics in Trinidad.Methods The study participants, who were all aged 18 years or older and attending walk-in clinics at 16 randomly selected health centres, were surveyed between May and August 2007 using the PRIME-MD questionnaire.Results There were 594 participants (the response rate was 92%), of whom 72.7% were female. Their ages ranged from 18 to 93 years, and 54.5% were over 50 years of age. In total, 37.2% were married and 25.9% were single. Indo-Trinidadians represented 43.1% and Afro-Trinidadians represented 36% of the study sample; 56.5% of the participants reported that their income was less than US$ 400 per month, and 65.7% were unemployed. At walk-in clinics in Trinidad, the estimated prevalence of severe undifferentiated somatoform disorder was 10.3% (95% CI: 7.86–12.74), that of hypochondriasis was 28.5% (95% CI: 24.9–32.1), and that of body dysmorphic disorder was 15.8% (95% CI: 11.9–18.7). Severe undifferentiated somatoform disorder was statistically significantly associated with gender and ethnicity but not with age, level of education, employment status or income. Chi-square testing found significant associations between the presence of severe undifferentiated somatoform disorder and both depression and anxiety (P < 0.05), between hypochondriasis and both anxiety and depression (P < 0.05), and between body dysmorphic disorder and depression (P < 0.05) but not anxiety. Regression analysis suggested that the demographic features that predicted severe undifferentiated somatoform disorder were being female or Indo-Trinidadian.Conclusions Walk-in clinics in Trinidad that serve older patients on a lower income have a high proportion of patients with somatoform disorders as measured by the PRIME-MD scale. These patients exhibit many features of anxiety and depression. These findings have implications for medical training and service delivery.     

Traditional medicinal plant knowledge and use by local healers in Sekoru District, Jimma Zone, Southwestern Ethiopia

The knowledge and use of medicinal plant species by traditional healers was investigated in Sekoru District, Jimma Zone, Southwestern Ethiopia from December 2005 to November 2006. Traditional healers of the study area were selected randomly and interviewed with the help of translators to gather information on the knowledge and use of medicinal plants used as a remedy for human ailments in the study area. In the current study, it was reported that 27 plant species belonging to 27 genera and 18 families were commonly used to treat various human ailments. Most of these species (85.71%) were wild and harvested mainly for their leaves (64.52%). The most cited ethnomedicinal plant species wasAlysicarpus quartinianus A. Rich., whose roots and leaves were reported by traditional healers to be crushed in fresh and applied as a lotion on the lesions of patients ofAbiato (Shererit). No significant correlation was observed between the age of traditional healers and the number of species reported and the indigenous knowledge transfer was found to be similar. More than one medicinal plant species were used more frequently than the use of a single species for remedy preparations. Plant parts used for remedy preparations showed significant difference with medicinal plant species abundance in the study area.     

Structures of human MAP kinase kinase 1 (MEK1) and MEK2 describe novel noncompetitive kinase inhibition

MEK1 and MEK2 are closely related, dual-specificity tyrosine/threonine protein kinases found in the Ras/Raf/MEK/ERK mitogen-activated protein kinase (MAPK) signaling pathway. Approximately 30% of all human cancers have a constitutively activated MAPK pathway, and constitutive activation of MEK1 results in cellular transformation. Here we present the X-ray structures of human MEK1 and MEK2, each determined as a ternary complex with MgATP and an inhibitor to a resolution of 2.4 A and 3.2 A, respectively. The structures reveal that MEK1 and MEK2 each have a unique inhibitor-binding pocket adjacent to the MgATP-binding site. The presence of the potent inhibitor induces several conformational changes in the unphosphorylated MEK1 and MEK2 enzymes that lock them into a closed but catalytically inactive species. Thus, the structures reported here reveal a novel, noncompetitive mechanism for protein kinase inhibition.     

Regulation of SLC11A3 by inflammation

Acute and chronic inflammatory states are characterized by changes in body iron metabolism. These changes include a drop in serum iron, an increase in the rate of plasma iron disappearance, a decline in the rate of plasma iron turnover, reticuloendothelial system (RES) cell iron sequestration and a decline in intestinal iron absorption. This response is elicited by a variety of metabolic conditions and acute bacterial infections, especially gram-negative bacteria, and by experimental mediators of inflammation such as endotoxin and turpentine. These changes in iron metabolism contribute to the development of the anemia of chronic diseases. SLC11A3 (aka MTP1, ferroportin 1, IREG1) is a metal transporter that exports iron from the cytosol of cells and was initially identified as the duodenal epithelial basolateral iron transporter. Recent identification of a MTP1 mutation leading to hemochromatosis in man adds further weight to the hypothesis that MTP1 is involved in iron homeostasis. RES cells are responsible for the recycling of iron from the breakdown of heme from senescent erythrocytes and MTP1 has been hypothesized to be the key iron exporter in these cells. Supporting this hypothesis is the observation that MTP1 is expressed in the RES macrophages of the spleen, Kupffer cells, bone marrow and lymph node histiocytes, mesangial cells, brain microglial cells. In a mouse (C57/Bl6) model of lipopolysaccharide (LPS) induced acute inflammation, MTP1 expression in the cells of the RES is regulated by acute inflammation. Immunohistochemical staining of tissues, using an anti-MTP1 antibody, of mice given parenteral injections of LPS demonstrated down-regulation of MTP1 expression in the RES cells of the spleen and liver and also in the duodenal epithelial cells compared to control animals. Western blotting of total liver and spleen lysates confirmed the decline in MTP1 protein expression induced by LPS. In addition, RT-PCR analysis showed that LPS treatment also resulted in a decline in MTP1 mRNA in spleen, liver and duodenum compared to controls. One clue to the molecular signaling mechanism for MTP1 down-regulation by LPS comes from the study of the C3H/HeJ mouse, which lacks a functional LPS receptor, toll-like receptor 4 (TLR4). C3H/HeJ mice are resistant to the toxic and hypoferraemic effects of LPS. Similarly, a down-regulation of MTP1 in response to LPS in the C3H/HeJ mice was not observed. This finding indicates that the down-regulation of MTP1 by LPS requires signaling through TLR4. Despite resistance to LPS, treatment of C3H/HeJ mice with turpentine, an inducer of sterile inflammation, for a period of 24 hours resulted in down-regulation of MTP1 expression in the spleen. These data indicate that LPS mediated down-regulation of MTP1 requires a functional TLR4, but that there are non-TLR4 dependent mechanisms for the down-regulation of MTP1 by inflammatory stimuli. In vitro treatment of mouse adherent splenocytes with 5 ug ml of LPS also resulted in down-regulation of MTP1 mRNA. This in vitro down-regulation was not abrogated by co-treatment of cells with pyrrolidinedithiocarbamate (PDTC), a well-characterized inhibitor of NF-KB activation or anti-tumor necrosis factor-a antibodies. In addition, in vitro treatment of mouse splenocytes with recombinant TNF- did not result in down-regulation of MTP1 mRNA. The lack of antagonism between LPS and PDTC and the lack of an effect of TNF- in vitro indicates that NF-B activation may not be required for MTP1 mRNA down-regulation. This inflammation-mediated down-regulation of MTP1 expression in the RES may be a component responsible for iron sequestration in the RES in both acute and chronic inflammatory states.     

Haptoglobin in lung defence

Haptoglobin (Hp) has been known to be associated with the host defence response to infection and inflammation. The biological functions of Hp can be related to its ability to bind haemoglobin or to modulate immune response. Hp is expressed at a high level in lung cells, yet its protective role(s) in the lung is not known. Using transgenic mice overexpressing Hp, we demonstrated that Hp can reduce blood-induced lung injury. Hp-mediated haemoglobin catabolism in lung cells appears to be linked to iron mobilization, and may be an efficient mechanism to reduce oxidative damage associated with haemolysis.