表皮生长因子在睾丸生精过程中的调节作用

表皮生长因子(Epidermal Growth Factor,EGF)是一种多肽激素,具有多种生物学活性,包括刺激各种上皮细胞的分裂与增殖。在雄性小鼠体内,大量的EGF产生于颌下腺。Tsutsumi指出EGF可能通过刺激生精发生过程中的减数分裂,而对男性生殖功能具有一种生理调节作用。我们通过对成熟与未成熟的小鼠施行颌下腺切除术,并于术后35天,对睾丸生精上皮周期中第7期与第8期的各级生精细胞进行了定量分析,结果显示未成熟小鼠在施行颌下腺切除手术后,生精上皮中各级生精细胞均少于相应的对照组;而成熟期小鼠在施行上述手术后仅A型精原细胞以后的各级生精细胞少于相应的对照组。这表明在精子发生过程中EGF不仅对减数分裂有刺激作用,而且对有丝分裂也有刺激作用。提示在控制精子发生过程中存在一个颌下腺-睾丸轴。     

Lymphadenopathy detected by ultrasound examination as first diagnostic hint of chronic lymphocytic leukaemia in a patient with melanoma

Recent reports indicate that patients with malignant melanoma might be at higher risk for developing a non-cutaneous unrelated second malignancy. We describe the case of a 46-year-old woman who had a malignant melanoma on her right shoulder that was treated in 1998 by surgical excision combined with axillary lymph node dissection. In 1999, ultrasound examination of peripheral lymph nodes revealed one suspicious echopoor structure in the woman's right axilla that was not palpable. Diagnostic excision and histopathological examination revealed a small B-cell lymphocytic lymphoma, and further investigations led to a diagnosis of chronic lymphocytic B-cell leukaemia (B-CLL). We would like to point out the value of high-resolution ultrasound examination in the follow-up of patients with malignant melanoma; this examination can detect early metastasis as well as other unrelated malignancies.     

Hypertrophy of C-1 anterior arch: useful sign to distinguish os odontoideum from acute dens fracture

Dens fractures are often difficult to detect radiographically because of overlapping structures. The lateral radiographs were examined of all patients at the authors' institution who demonstrated an abnormal odontoid process or an abnormal anterior arch of C-1. Six patients were found: Four had os odontoideum, one had rheumatoid arthritis, and one had a congenital defect in the posterior arch of C-1. All had hypertrophy of the C-1 anterior arch on the lateral view. The width of the anterior arch of C-1 and the cortical thickness of the anterior arch in these six patients were measured and compared with the findings in a control group of 20 patients; the measurements from the six patients were found to be significantly greater. Hypertrophy of the anterior arch of C-1 is a useful sign of a chronic pathologic condition at the atlantoaxial articulation, and in the setting of acute trauma it may be an important clue that prevents unnecessary invasive treatment for a mistaken diagnosis of fractured dens.     

不同血液净化方法对维持性血液透析患者微炎症的影响比较

目的观察LFHD、HFHD及HDF三种血液净化方法对MHD患者微炎症状态的影响。方法将125例MHD患者根据血液净化方法分为三组：低通量血液透析（LFHD）组42例、高通量血液透析（HFHD）组41例和血液透析滤过（HDF）组42例。观察各组患者的CRP、IL-6、IL-8及TNF-α水平。结果 LFHD组患者透析前、首次透析后及透析6个月后的CRP、IL-6、IL-8及TNF-α水平无显著性差异（P〉0.05）;HFHD组患者透析6个月后CRP、IL-6、IL-8及TNF-α水平较透析前显著下降（P〈0.01）;HDF组首次透析后及透析6个月后CRP、IL-6、IL-8及TNF-α水平较透析前显著下降（P〈0.01）;HDF组透析6个月后CRP、IL-6、IL-8及TNF-α水平显著低于HFHD组（P〈0.01）。结论 HDF治疗及长期的HFHD治疗均能有效的改善MHD患者的微炎症状态,且HDF治疗的效果好于HFHD治疗。     

Small cell osteosarcoma of a toe phalanx: a case report and review of literature

This report describes the radiological and histological findings of a small cell osteosarcoma of a toe phalanx in a 38 year old man. This man presented with pain, swelling and redness of the left third toe. Medical history revealed an osteomyelitis of this toe eight years prior. Based on clinical findings and medical history the lesion was diagnosed as an osteomyelitis. However, peroperatively the lesion had a malignant aspect. Histological examination revealed a small cell osteosarcoma of the proximal phalanx.     

Pelvic exenteration and sphincter preservation in the treatment of soft tissue sarcomas.

BACKGROUND: Pelvic sarcomas are rare and there are very few effective therapeutic alternatives. A complete resection is considered the main factor associated to a good prognosis, which justifies the employment of a pelvic exenteration (PE) in selected cases. METHODS: Between 1980 and 2000, 96 PE were performed, nine of which were for sarcomas. The clinical characteristics, surgical and anatomopathological aspects and the patients' evolution were described. RESULTS: The median follow-up time was 24 months (ranging from 1 to 57 months). In relation to the sphincters preservation, at least one sphincter was preserved in five patients. There were two post-operative deaths. In the last follow-up, six patients were alive without any evidence of the disease. CONCLUSION: Pelvic exenterations should be performed for the treatment of selected cases of locally advanced pelvic sarcomas. Sphincter preservation may be performed, provided that oncological resection principles are obeyed.     

Molecularly designed alginate hydrogels susceptible to local proteolysis as three-dimensional cellular microenvironments

The development of sophisticated three-dimensional (3-D) cell culture microenvironments that recreate some of the complexity of the natural extracellular matrix (ECM) remains a challenging task. Here, the modification of alginate through partial crosslinking with a matrix metalloproteinase (MMP) cleavable peptide (proline-valine-glycine-leucine-isoleucine-glycine, PVGLIG) is described, and its use in the preparation of injectable, in situ crosslinkable hydrogel-like matrices is proposed. PVGLIG-grafted alginates were synthesized by carbodiimide chemistry and characterized. Their biological performance was evaluated by comparing the response of 3-D cultured mesenchymal stem cells (MSCs) to alginate hydrogels containing only cell-adhesion peptides (RGD-alginate) or both peptides (PVGLIG/RGD-alginate). After 1 week, cells remained essentially round within RGD-alginate, while they exhibited an elongated morphology within PVGLIG/RGD-alginate hydrogels, forming cellular networks. This suggests that cells were able to structurally reorganize the matrix, through enzymatic hydrolysis of PVGLIG residues, overcoming biophysical hydrogel resistance. As shown by gelatine-zymography, MSC presented higher activity of MMP-2 when cultured within alginate functionalized with MMP-sensitive peptide, suggesting that the cell's proteolytic phenotype was modulated by the matrix composition. Additionally, PVGLIG/RGD-alginate hydrogels were clearly degraded in cell culture. Taken together, the results demonstrate that the co-incorporation of MMP-labile peptides in cell-adhesive RGD-alginate hydrogels improved their performance as ECM analogues, providing a more dynamic and physiological 3-D cellular microenvironment.     

HIV感染前的药物预防

尽管全球人类免疫缺陷病毒(HIV)感染在目前已趋稳定并呈下降趋势,但2008年整个世界仍有2 700万新感染HIV的病人,因此预防HIV-1感染者向正常人群的传播仍是当务之急[1]。近些年来,HIV-1感染的预防研究集中在男子包皮环切、疫苗、局部杀微生物药和用抗逆转录病毒药物(ARVs)作