巨细胞病毒感染对新生豚鼠胸腺的影响

新生豚鼠皮下接种豚鼠巨细胞病毒(GPCMV)后,导致动物胸腺急性感染。感染豚鼠胸腺在接种后第五天开始出现病毒,第十天达高峰。此外,感染动物胸腺的发育受到抑制,细胞总数和T淋巴细胞数随朐腺中病毒滴度的增高而进行性下降,至接种GPCMV后第十天最显著。由于病毒对T细胞的作用,细胞表面红细胞受体的丧失导致胸腺Null细胞百分比高于对照动物。     

Intralobular lymphatic vessels and their relationship to blood vessels in the mouse thymus

Summary The spatial distribution and fine structure of the lymphatic vessels within the thymic lobules of normal and hydrocortisone-injected mice were studied by light- and electron microscopy. The lymphatic vessels of the cortex and medulla of normal thymus are irregularly shaped spaces closely associated with branches of the intralobular artery and vein. The overall distribution of these vessels in the greatly involuted thymus of hydrocortisone-treated mice is essentially the same as in the normal thymus. The wall of the lymphatic vessels consists of only a layer of endothelial cells supported by underlying reticular cells. The luminal surface of the endothelial cell is smooth, but trabecular processes are often seen. There are three morphological types of intercellular contacts between contiguous cells, namely, end-to-end, overlapping and interdigitating. The lymphatic vessel has anchoring filaments and collagen fibrils, but a basal lamina is either absent, or if present, is discontinuous. This is in contrast to the continuous basal lamina of the venule. The perivascular space surrounding the postcapillary venule opens into a terminal lymphatic vessel at the cortico-medullary junction and in the medulla. Lymphocytes are seen penetrating the lymphatic endothelium, particularly in acutely involuted thymuses. These findings suggest that the intralobular lymphatic vessels may originate from the vacuities that surround the postcapillary venules, and the lymphatic system may function as a pathway for the migration of lymphocytes into or out of the lymphatic circulation.     

Implantation of cultured thymic fragments in congenitally athymic (nude) rats

Summary Cultured thymic fragments correspond to the thymic microenvironment depleted of lymphocytes and dendritic cells. When these fragments are implanted under the kidney capsule of congenitally athymic rats, lymphocytes and dendritic cells of host origin enter the graft and induce thymus-dependent immunity in the recipient. This paper describes the ultrastructure of the fragments and the changes that occur during the restoration of normal thymic architecture. At the end of the culture period of 6–9 days and in the early stages after implantation, the grafts consist of keratin-containing epithelial cells of unusual morphology that can be labelled with antibodies raised against the epithelium of the mid/deep cortex and the subcapsule/medulla. Normal thymic architecture develops, including nerves and blood vessels, as lymphocytes populate the environment, and by 4–6 weeks the epithelial cells are the same phenotypically and ultrastructurally as those found in normal rat thymus. However, some areas without lymphocytes still contain the atypical epithelial cells seen before implantation. Large multinucleated giant cells are also present with a few associated epithelial cells of subcapsular/medullary phenotype. In conclusion, the cultured thymic fragments contain a hitherto unknown precursor epithelial cell with an atypical ultrastructure and phenotype that is not seen in normal development.     

Distribution and ultrastructure of S-100-immunoreactive cells in the human thymus

Summary The present study deals with the localization and ultrastructure of S-100-immunoreactive cells in the human thymus. These immunoreactive cells are distributed mainly in the medulla with some scattered elements in the cortex. Electron-microscopic observation revealed that the cells are characterized by an irregularly shaped nucleus, tubulovesicular structures in the cytoplasm and characteristic interdigitations of the plasma membrane. The cells often embrace lymphocytes with their branched processes. On the basis of these morphological features, the immunostained elements were identified as interdigitating cells (IDCs). The immunocytochemistry for S-100 visualizes the precise distribution and extension of the IDCs under the light microscope and indicates that the IDCs form no structural networks such as those established by the thymic epithelial cells. Since the IDCs in human lymph nodes have also been reported to contain S-100-like immunoreactivity, S-100 protein can be regarded as a useful marker for identifying the IDCs in the human thymus and other lymphoid organs.     

Tobacco smoking and alcohol consumption as risk factors for thymoma – A European case-control study

PurposeHardly anything is known about the aetiology of thymoma. This paper presents data regarding tobacco smoking and alcohol consumption in relation to thymoma from the first case-control study performed on this rare tumour.MethodsA European multi-centre case-control study including incident cases aged 35–69 years with thymoma between 1995 and 1997, was conducted in seven countries. A set of controls, used in seven parallel case-control studies by the same research group was used, including population-based controls from five countries and hospital controls with colon cancer from two countries. Altogether 103 cases, accepted by a reference pathologist, 712 colon cancer controls, and 2071 population controls were interviewed.ResultsTobacco smoking was moderately related with thymoma (OR 1.4, 95% CI 0.9–2.2), and a tendency to dose-response was shown (p = 0.04), with an increased risk for heavy smokers defined as ≥41 pack-years (OR 2.1, 95% CI 1.1–3.9). A high consumption of spirits defined as ≥25 g of alcohol per day was associated with an increased risk of thymoma (OR 2.4, 95% CI 1.1–5.4), whereas no association was found with beer or wine.ConclusionsTobacco smoking and a high intake of spirits were indicated as risk factors for thymoma.     

Detection of apoptotic cell death in the thymus of dexamethasone treated rats using [<Superscript>123</Superscript>I]Annexin V and in situ oligonucleotide ligation

In the present study we aimed to establish an animal model of dexamethasone (DEX)-induced apoptosis in the thymus of rats. The degree of apoptosis was determined in the same animals at 6 and 11 h after a single administration of DEX (5 mg/kg, ip) by (a) in vivo biodistribution of the uptake of [¹²³I]Annexin V, a biomarker of the early stages of apoptosis; (b) in vitro evaluation of the apoptotic index (percentage of number of apoptotic cells versus total number of cells) in the form of DNA fragmentation, on tissue sections using in situ oligo ligation (ISOL). ISOL demonstrated a 62- and 90-fold increase of apoptotic index at 6 and 11 h after DEX administration respectively, in the outer part of the thymic lobule (cortex) and a 25- and 54-fold increases in the inner part of the thymic lobule (medulla) in the corresponding treatment groups. In the biodistribution study, [¹²³I]Annexin V uptake was significantly increased in the thymus of rats 11 h after DEX administration (by 1.3- to 1.4-fold) and significantly decreased at the 6-h time point. We conclude that the specificity of the apoptotic signal provided by isotopic methods in vivo would always require confirmation by complementary in vitro techniques that verify the assessment of ongoing apoptosis accurately.     

生于豆科植物上的链格孢属真菌一新种

报道生于豆科植物沙冬青Ammopiptanthus mongolicus上的链格孢属真菌一新种,沙冬青链格孢Alternaria ammopiptanthi。此种不同于已从豆科植物上报道的5个长喙链格孢种(复喙链格孢A.multirostrata、决明链格孢A.cassiae、猪屎豆生链格孢A.crotalariicola、瓜尔豆链格孢A.cyamopsidis和长喙链格孢A.longirostrata),主要是其分生孢子的长喙不分枝和孢身细瘦。研究过的模式标本(PSNXAAFS267852)保存在宁夏农林科学院植物病害标本室。     

The thymus as a target for mycobacterial infections

Mycobacterial infections are among the major health threats worldwide. Ability to fight these infections depends on the host's immune response, particularly on macrophages and T lymphocytes produced by the thymus. Using the mouse as a model, and two different routes of infection (aerogenic or intravenous), we show that the thymus is consistently colonized by Mycobacterium tuberculosis, Mycobacterium avium or Mycobacterium bovis BCG. When compared to organs such as the liver and spleen, the bacterial load reaches a plateau at later time-points after infection. Moreover, in contrast with organs such as the spleen and the lung no granuloma were found in the thymus of mice infected with M. tuberculosis or M. avium. Since T cell differentiation depends, to a large extent, on the antigens encountered within the thymus, infection of this organ might alter the host's immune response to infection. Therefore, from now on, the thymus should be considered in studies addressing the immune response to mycobacterial infection.     

Activity of Six Essential Oils Extracted from Tunisian Plants against Legionella pneumophila

The aim of this study was to investigate the composition of six essential oils extracted from Tunisian plants, i.e., Artemisia herba‐alba Asso , Citrus sinensis (L.) Osbeck , Juniperus phoenicea L., Rosmarinus officinalis L., Ruta graveolens L., and Thymus vulgaris L., and to evaluate their activity against Legionella pneumophila (microdilution assays). Eight Legionella pneumophila strains were studied, including the two well‐known serogroup 1 Lens and Paris strains as controls and six environmental strains isolated from Tunisian spas belonging to serogroups 1, 4, 5, 6, and 8. The essential oils were generally active against L. pneumophila. The activities of the A. herba‐alba, C. sinensis, and R. officinalis essential oils were strain‐dependent, whereas those of the J. phoenicea and T. vulgaris oils, showing the highest anti‐Legionella activities, with minimum inhibitory concentrations (MICs) lower than 0.03 and lower than or equal to 0.07 mg/ml, respectively, were independent of the strains' serogroup. Moreover, the microorganisms treated with T. vulgaris essential oil were shorter, swollen, and less electron‐dense compared to the untreated controls. Isoborneol (20.91%), (1S)‐α‐pinene (18.30%) β‐phellandrene (8.08%), α‐campholenal (7.91%), and α‐phellandrene (7.58%) were the major components isolated from the J. phoenicea oil, while carvacrol (88.50%) was the main compound of the T. vulgaris oil, followed by p‐cymene (7.86%). This study highlighted the potential interest of some essential oils extracted from Tunisian plants as biocides to prevent the Legionella risk.     

百里香研究进展

百里香属植物在我国分布广泛,具有优良的生态适应性和潜在的园林观赏价值,近年来开始被开发利用。主要将近年来有关百里香繁殖栽培技术方面的研究作一综述,同时在百里香育种方面提出期望,为进一步开发应用提供参考。