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     

Spoilage association of chicken skin.

The bacterial succession on the skin of broiler chicken carcasses stored at 2 degrees C was traced, and the ability of representative isolates to produce off-odors was determined by using sterile leg and breast muscle sections. Off-odors were identified by olfactory and chemical means. The inability of peptone-iron agar to detect sulfide-producing strains was noted.     

Effect of solar radiation and predacious microorganisms on survival of fecal and other bacteria.

The effect of solar radiation and predacious microorganisms on the survival of bacteria of fecal and plant origin was studied. The decline in the numbers of Escherichia coli cells in estuarine water samples was found to be significantly greater in the presence of both naturally occurring microbial predators and solar radiation than when each of these factors was acting independently. The effect of solar radiation on microbial predators was negligible, whereas the susceptibility of bacteria to light-induced decay varied from one organism to another, as follows: Klebsiella pneumoniae greater than E. coli greater than Salmonella typhimurium, Streptococcus faecium, Enterobacter aerogenes, Erwinia herbicola.     

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.     

Behaviour of Listeria monocytogenes under combined chilling processes

The behaviour of Listeria monocytogenes under chilling processes was investigated. Growth kinetics were measured at 7 degrees C in TSBYE culture medium as a function of pH (7.2 and 6.2), pre-incubation temperatures (4 or 7 degrees C), cooling (0.05 or 0.1 degree C min-1) and freezing (0 and -5 degrees C) treatments. Growth curves generated were fitted by Gompertz and Baranyi functions. The Baranyi function gave better parameter estimation values than the Gompertz equation which over-estimated the specific growth rate values. Listeria monocytogenes grew at 7 degrees C without a lag phase, except when the sub-culture was performed at 37 degrees C, whereas the specific growth rate was affected by the chilling processes. In fact, L. monocytogenes grew slightly faster at 7 degrees C when a 4 degrees C pre-incubation treatment was applied than with a 7 degrees C pre-incubation treatment. These results suggest that to mimic the processes of contamination in industry, predictive microbiology studies with L. monocytogenes should be performed with organisms cultured at low temperatures.     

Sterol and Squalene Content of a Docosahexaenoic-Acid-Producing Thraustochytrid: Influence of Culture Age, Temperature, and Dissolved Oxygen

Thraustochytrid strain ACEM 6063, rich in omega-3 polyunsaturated fatty acids, was cultured at 15°C and 20°C in high (>40%) and low (<5%) dissolved oxygen (DO), and at 25°C in low-DO media. Samples were taken 4, 2, and 0 days before each culture reached peak biomass (T₋₄, T₋₂, and T_p, respectively). Twenty sterols, 13 of which were identified, were detected. Predominant were cholest-5-en-3β-ol, 24-ethylcholesta-5,22E-dien-3β-ol, 24-methylcholesta-5,22E-dien-3β-ol, and 2 coeluting sterols, one of which was 24-ethylcholesta-5,7,22-trien-3β-ol. These 4 sterols comprised 50% to 90% of total sterols. Cultures grown at high DO had simpler sterol profiles than those grown at low DO. Only the 4 sterols mentioned above were present at more than 3% of total sterols in high-DO cultures. In low-DO cultures, up to 6 additional sterols were present at more than 3% of total sterols. Culture age, temperature, and DO influenced squalene and sterol content. Total sterols (as a proportion of total lipids) decreased with increasing culture age. If organisms such as ACEM 6063 are to be used for commercial production of lipid products for human consumption, both their sterol content and factors influencing sterol production need to be characterized thoroughly. Received January 8, 2001; accepted March 6, 2001.