Progression of Epididymal Maldevelopment Into Hamartoma-like Neoplasia in VHL Disease

Inactivation of the von Hippel-Lindau (VHL) gene and activation of the hypoxia-inducible factor (HIF) in susceptible cells precedes formation of tumorlets and frank tumor in the epididymis of male VHL patients. We performed detailed histologic and molecular pathologic analysis of tumor-free epididymal tissues from VHL patients to obtain further insight into early epididymal tumorigenesis. Four epididymides from two VHL patients were serially sectioned to allow for three-dimensional visualization of morphologic changes. Areas of interest were genetically analyzed by tissue microdissection, immunohistochemistry for HIF and markers for mesonephric differentiation, and in situ hybridization for HIF downstream target vascular endothelial growth factor. Structural analysis of the epididymides revealed marked deviations from the regular anatomic structure resulting from impaired organogenesis. Selected efferent ductules were represented by disorganized mesonephric cells, and the maldeveloped mesonephric material was VHL-deficient by allelic deletion analysis. Furthermore, we observed maldeveloped mesonephric material near cystic structures, which were also VHL-deficient and were apparent derivatives of maldeveloped material. Finally, a subset of VHL-deficient cells was structurally integrated in regular efferent ductules; proliferation of intraductular VHL-deficient cells manifests itself as papillary growth into the ductular lumen. Furthermore, we clarify that that there is a pathogenetic continuum between microscopic tumorlets and formation of tumor. In multiple locations, three-dimensional reconstruction revealed papillary growth to extend deeply into ductular lumina, indicative of progression into early hamartoma-like neoplasia. We conclude epididymal tumorigenesis in VHL disease to occur in two distinct sequential steps: maldevelopment of VHL-deficient mesonephric cells, followed by neoplastic papillary proliferation.     

乳酸脱氢酶实验检测细胞新陈代谢的实验研究

目的 探索LDH实验检测细胞活力的可行性。方法 原代培养骨髓细胞和软骨细胞，用LDH实验测定上述两组细胞的活力，并与镜下活体观察到细胞的生长状况相比较。与目前比较成熟的测定细胞活力的MTS实验的测得的值相比较。结果 LDH实验对上述两组细胞的活力的测定结果与镜下活体观察到的结果相符合。与MTS实验的测得的结果经统计学处理无显著差异。结论 LDH实验可用于细胞活力的直接测定，而对活细胞的生存、繁殖无影响。     

Mutations in the Ca(2+)-sensing receptor gene cause autosomal dominant and sporadic hypoparathyroidism

Parathyroid hormone secretion is negatively regulated by a 7- transmembrane domain, G-protein coupled Ca(2+)-sensing receptor. We hypothesized that activating mutations in this receptor might cause autosomal dominant hypoparathyroidism (ADHP). Consistent with this hypothesis, we identified, in two families with ADHP, heterozygous missense mutations in the Ca(2+)-sensing receptor gene that cosegregated with the disorder. None of 50 normal controls had either mutation. We also identified a de novo, missense Ca(2+)-sensing receptor mutation in a child with severe sporadic hypoparathyroidism. The amino acid substitution in one ADHP family affected the N-terminal, extracellular domain of the receptor. The other mutations involved the transmembrane region. Unlike patients with acquired hypoparathyroidism, patients with these mutations had hypercalciuria even at low serum calcium concentrations. Their greater hypercalciuria presumably reflected activation of Ca(2+)-sensing receptors in kidney cells, where the receptor negatively regulates calcium reabsorption. This augmented hypercalciuria increases the risk of renal complications and thus has implications for the choice of therapy.      

壳聚糖/聚乙二醇琥珀酸酯薄膜的制备及其与肌成纤维细胞的相容性

目的：制备防粘连壳聚糖/聚乙二醇琥珀酸酯薄膜并观察其与肌成纤维细胞的相容性。方法：实验于2006-05/11在南方医科大学附属珠江医院中心实验室完成。实验材料：在透析后的壳聚糖与聚乙二醇琥珀酸酯或聚乙二醇共混后置入冻干机冻干制得壳聚糖/聚乙二醇琥珀酸酯薄膜或壳聚糖/聚乙二醇膜，并将新生2～5d的SD大鼠骨骼肌成纤维细胞种植于膜片上。实验评估：①MTT法测定肌成纤维细胞接种在不同膜片上的吸光度值，计算相对贴附率。相对贴附率=不同膜的A490nm/培养板的A490nm×100%。②MTT法测定肌成纤维细胞在不同膜片上的生长1，5d后的吸光度值。③相差显微镜下观察肌成纤维细胞的生长形貌。结果：①肌成纤维细胞在不同膜片上的贴附率：肌成纤维细胞在壳聚糖/聚乙二醇琥珀酸酯薄膜上能良好黏附、增殖，而在壳聚糖/聚乙二醇膜、壳聚糖膜上黏附性差。联合培养12h，5d后MTT法结果显示，壳聚糖/聚乙二醇琥珀酸酯组的A值分别为0.074±0.009，0.141±0.031，分别为壳聚糖组的6.17倍和6.13倍（P〈0.05）。②肌成纤维细胞的生长特性：肌成纤维细胞在壳聚糖/聚乙二醇琥珀酸酯膜上的活性最高，增殖能力最强，增长速度最快，其次为壳聚糖/聚乙二醇膜，但两者差异无显著性意义（P〉0.05），而细胞在壳聚糖膜上的增殖能力较低，膜上细胞数目较少，与其他组比较差异有显著性意义（P〈0.05）。③肌成纤维细胞与不同膜片联合培养1，5d时的生长形貌：壳聚糖膜上细胞未贴壁生长，为透明的圆球形，呈游离状态，未能很好舒展，且有些皱缩，生长活力也不旺盛;细胞与壳聚糖/聚乙二醇膜、壳聚糖/聚乙二醇琥珀酸酯膜片联合培养的生长情况要明显好于壳聚糖膜，细胞相互融合成片，多呈长梭形，细胞间隙狭窄，紧密排列成束，成指纹状结构且聚集生长的趋势也更明显。结论：将接支琥珀酰基的聚乙二醇与壳聚糖共混组成的网状系统改进了膜片的力学性能，提高了膜片的柔韧性，使其成膜性更好;壳聚糖/聚乙二醇琥珀酸酯薄膜具有良好的生物相容性，肌成纤维细胞在壳聚糖/聚乙二醇琥珀酸酯薄膜上的黏附及生长情况明显好于壳聚糖薄膜。     

Cell-based therapy in Alzheimer's disease: can human fetal cholinergic neurons “untangle the skein”?

正Alzheimer’s disease(AD)is a devastating neurodegenerative disorder and the most common form of old-age dementia.The disease is characterized by a progressive decline in cognitive functions,gradual loss of memory and ability to perform everyday activities,and leads to inevi-     

Giant condyloma acuminatum of the anorectum: successful radical surgery with anal reconstruction

Buschke-L?wenstein tumor, or giant condyloma acuminatum, is a relatively uncommon lesion of the anus with aggressive local invasive behavior which may present as a large warty tumor of the genital region with expansive and destructive growth. Many sporadic reports have been published suggesting various therapeutic strategies. We report a case of Buschke-L?wenstein tumor treated with conservative surgery followed by reconstructive procedures without a loop colostomy     

Metastasis of sigmoid colon cancer in cryptorchid testis: report of a case

Isolated testicular metastasis from colorectal cancer is considered an unusual event. In this case report we describe for the first time a metastasis from an adenocarcinoma of the sigmoid colon to a cryptorchid testis. The patient developed a painless testicular nodule three years after the diagnosis of primary sigmoid colon cancer. Recent reports have suggested that the incidence of genitourinary abnormalities in human males has increased over the past 50 years; in particular, cryptorchid testes increase the clinical risk factors for primary or metastatic testicular cancer. In conclusion, there should be awareness of the risk of metastasis of colorectal cancer to the testis in the workup of patients with testicular symptoms. Furthermore, patients with colorectal cancer and cryptorchidism should be managed with a single surgical intervention: when the primary colorectal tumor is removed, the cryptorchid testicle should also be removed to reduce the risk of late metastases.     

Effects of riboflavin/UVA corneal cross‐linking on keratocytes and collagen fibres in human cornea

Purpose: To evaluate the effects of corneal cross‐linking on keratocytes and collagen fibres in human corneas. Methods: Fifteen corneal buttons were examined. Ten were from patients with keratoconus submitted to penetrating keratoplasty and five of them were treated with cross‐linking 6 months before penetrating keratoplasty. Five normal corneal buttons from healthy donors were used as controls. All samples were prepared for TUNEL assay and Western blot analysis for the detection of keratocyte apoptosis and immunohistochemical analysis for the morphological evaluation of keratocytes and collagen fibre diameter. Results: Normal corneas exhibited no TUNEL‐positive keratocytes and keratoconic and cross‐linked corneas showed moderate apoptotic cells mainly in the anterior part of the stroma. This apoptotic trend was confirmed by the cleavage of poly (ADP‐ribose) polymerase assessed using Western blot. The Ki‐67 staining showed a significant increase in the keratocyte proliferation in cross‐linked corneas compared with normal and keratoconus. In cross‐linked corneas CD34‐positive keratocytes were regularly distributed throughout the whole corneal stroma as in the control, and keratoconus was associated with patchy loss of immunoreactivity. The immunohistochemical analysis of collagen type I showed a significant increase in fibre diameter of cross‐linked corneas compared with control and keratoconus. Conclusion: Corneal cross‐linking leads to keratocyte damage; after 6 months a repopulation by proliferating cells, a distribution of CD34‐positive keratocytes as in control and an increase in collagen fibre diameter were observed. These modifications are the morphological correlate of the process leading to an increase in biomechanical stability.