Telomerase activity in patients with chronic myeloid leukemia and lymphoma

Telomeres are repeated DNA sequences, positioned at the ends of chromosomes and are essential for the stable maintenance of chromosomes. The telomere length serves as a mitotic clock determining the remaining replicative capacity of the cell. Telomeric sequences are lost during each cell division, leading to a process thought to contribute to senescence and cell death. The enzyme telomerase adds 5'-TTAGGG-3' repeats to the mammalian telomeres and maintains the telomere length. Telomerase is normally inactive in most somatic cells but telomerase activity is observed in malignancies. In this study telomerase activity was analyzed in patients with chronic myeloid leukemia (CML) and lymphoma by PCR and ELISA. This approach combines highly specific amplification of the telomerase-mediated elongation products with nonradioactive detection in a highly sensitive photometric ELISA. The PCR products were also analyzed by Southern blotting. The telomerase-specific PCR products were seperated by electrophoresis and transferred to a nylon membrane with subsequent detection of the biotinylated amplificates. High activity levels were detected in 17 CML ( 34%) patients. On the other hand, no activity was observed in lymphoma patients. An increase in the shorter telomeric bands was observed in CML patients who displayed a high level of telomerase activity. In contrast to the low enzyme activity, evidence of telomeric repeats were also found in some lymphoma patients by Southern blotting. This may indicate that lymphoma cells may make use of different pathways for maintaining the length of their telomeres.     

Telomerase activity of peripheral blood lymphocytes in patients with chronic hepatitis B

Chronic hepatitis B is the immunocompromising condition. The decrease of lymphocyte telomerase is linked to immunosenescence in hosts. To know whether telomerase activity of lymphocytes is involved in immunopathogenesis in patients with chronic hepatitis B, telomerase activity of peripheral lymphocytes was determined in such patients. The results showed that telomerase activity in resting peripheral lymphocytes of healthy subjects was detectable at low level, and obviously increased (P<0.001) after stimulation in vitro with phytohaemagglutinin (PHA). Telomerase activity of lymphocytes decreased with age in both groups with or without PHA stimulation. Telomerase activity of resting lymphocytes in patients with chronic hepatitis B was also observed at detectable level and markedly upregulated after PHA stimulation. The decreased telomerase activity of resting lymphocytes was found in patients with chronic hepatitis B (n=14, 0.32+/-0.27) compared to that in healthy subjects (n=17, 0. 52+/-0.28; P<0.05). However, there was no difference present between these two groups in telomerase activity of activated lymphocytes with PHA. In addition, no effect of recombinant human interleukin-12 (rhIL-12) on telomerase expression was observed in either the patient group or the healthy group. We concluded that the decreased telomerase activity of lymphocytes in chronic hepatitis B patients is present, which may be partly responsible for immunosuppressive condition in such patients.     

正常人淋巴细胞端粒酶活性的观察

目的：探讨正常人外周血淋巴细胞端粒酶活性表达情况。方法：采用聚合酶链反应－酶联免疫吸附（ＰＣＲ－ＥＬＩＳＡ）法测定正常人淋巴细胞经植物血凝素（ＰＨＡ）刺激前后端粒酶的活性水平及重组人白细胞介素１２（ｒｈＩＬ－１２）对端粒酶活性的影响。结果：正常人外周血静息淋巴细胞有低水平的端粒酶活性表达,但经ＰＨＡ刺激后活性明显升高,没有发现ｒｈＩＬ－１２对端粒酶活性的影响。结论：正常人外周血淋巴细胞可表达端粒酶     

Telomerase activity in gestational trophoblastic disease

AIMS: To investigate the pattern of telomerase activity in hydatidiform mole as compared with normal placenta and choriocarcinoma, and to determine the prognostic significance of telomerase activity in hydatidiform mole. METHODS: Telomerase activity in 35 cases of hydatidiform mole, 35 normal placentas, one choriocarcinoma sample, and two choriocarcinoma cell lines (JAR, JEG3) was determined using the sensitive polymerase chain reaction based telomeric repeat amplification protocol (TRAP) assay. Two cases of breast carcinoma and two cases of ovarian carcinoma were also included as positive controls in the telomerase assay. RESULTS: Telomerase activity was detected in 11 of 30 early placentas (36.7%), one of five term placentas (20%), five of 27 hydatidiform moles which regressed spontaneously (18.5%), and six of eight hydatidiform moles which developed persistent trophoblastic disease (75%) (including three which developed metastases). Hydatidiform moles which subsequently developed persistent disease, especially those which metastasised, were more likely to express telomerase activity (p < 0.01). However, there was no significant difference in the frequency of telomerase activity between early placentas and hydatidiform mole. Strong telomerase activity was observed in choriocarcinoma tissue, choriocarcinoma cell lines, and ovarian and breast carcinomas. CONCLUSIONS: Telomerase activation occurs in hydatidiform mole with a similar incidence to early normal placentas. This supports the concept that hydatidiform mole is essentially an abnormal conceptus. There is an association between telomerase activation and the development of persistent trophoblastic disease. Further study is warrant to confirm the prognostic significance of telomerase activity in hydatidiform mole.     

Telomerase activity and the risk of lung cancer

Telomerase play a key role in the maintenance of telomere length and chromosome integrity. We have evaluated the association between telomerase activity and the risk of lung cancer in peripheral blood. Telomerase activity in peripheral blood mononuclear cells was measured by a PCR-designed telomeric repeat amplification protocol in 63 lung cancer patients and 190 healthy controls that were matched for age, gender, and smoking status. Telomerase activity was significantly lower in the lung cancer patients than in controls (mean ± standard deviation; 1.32 ± 1.65 vs 2.60 ± 3.09, P < 1 × 10(-4)). When telomerase activity was categorized into quartiles based on telomerase activity in the controls, the risk of lung cancer increased as telomerase activity reduced (P(trend) = 1 × 10(-4)). Moreover, when the subjects were categorized based on the median value of telomerase activity, subjects with low telomerase activity were at a significantly increased risk of lung cancer compared to subjects with high telomerase activity (adjusted odds ratio = 3.05, 95% confidence interval = 1.60-5.82, P = 7 × 10(-4)). These findings suggest that telomerase activity may affect telomere maintenance, thereby contributing to susceptibility to lung cancer.     

Immune privilege and inflammation of the testis – lessons from the infertile male

Immune cells are regular components of the testis and likely to participate in the complex local regulation of testicular function. Studies in experimental animals indicate that the testis is an immunologically privileged site where germ cell antigens are protected from autoimmune attack and foreign tissue grafts may survive for extended periods. However, the testicular environment does not preclude immune activation resulting in inflammatory reactions. Active immunization with testicular tissue or adoptive transfer of specific T lymphocytes causes autoimmune orchitis. Whereas symptomatic orchitis due to viral or bacterial infections is considered to be rare in man, recent studies among infertile males revealed a high prevalence of asymptomatic testicular inflammatory reactions associated with impaired spermatogenesis. Notably, the infiltration of T lymphocytes into the testis reflects disturbance of the delicate local immunoregulation. Both predominant peritubular localization of lymphocytes and characteristic morphological changes of the seminiferous tubules support the concept that activation of autoreactive T cells inducible by various etiological factors including noninfectious agents is involved. With regard to localization and functional polarization of T lymphocytes, adhesion molecules as well as chemokines and their receptors have to be considered as crucial components. In conclusion, immunopathological reactions in the testis should not be neglected as underlying reason or cofactor of male infertility. Further investigation of the mechanisms that regulate testicular immune functions in health and disease may encourage the search for appropriate therapeutic strategies such as specific immunomodulation.     

An ultrastructural study on the presence of various types of crystals in the infertile human testis

Summary Testicular biopsies obtained from 23 infertile outpatients, found to be normal except for oligospermia, were investigated using a Zeiss electron microscope. Ultrastructural changes in the Sertoli cells were encountered frequently, whilst most of the spermatogenic cells were degenerative. Sertoli cells exhibited abundant microfilaments which were seen to form small clusters leading to the formation of Charcot-Böttcher crystals, whilst the Leydig cells of the same specimens revealed the presence of small microtubular arrays and numerous small sized crystals. Fusion of small sized crystals resulted in the formation of typical Reinke crystals in the Leydig cells. Crystalloid structures similar to those seen in the Sertoli cells were also observed in the cytoplasm of type-A-spermatogonia and in a number of multinucleated cells with cytoplasmic characteristics of spermatogonia and Sertoli cells. Similar crystallization processes in both Sertoli and Leydig cells imply a close relationship between crystallization processes and impairment of spermatogenesis.Part of this study was presented at the 7th European Anatomical Congress held in Innsbruck, 1984     

Telomerase activity in the human endometrium throughout the menstrual cycle

In a total of 41 endometrial tissue samples, the relationship between telomerase activity and proliferating cell nuclear antigen (PCNA) labelling index was studied. In samples of endometrium from the proliferative phase of the menstrual cycle, telomerase activity was found in 15 out of 17 cases (88%). Two samples from the early proliferative phase showed negative telomerase activity and a low PCNA labelling index. However, three out of 16 samples of early secretory phase endometrium showed telomerase activity and a PCNA labelling index. In mid- to late secretory phase endometrium, in menopausal endometrium and in decidualized endometrium induced by progesterone neither telomerase activity nor PCNA labelling was found. These results suggest that telomerase activity of the endometrium may be correlated with the proliferative potential of the epithelial cells and that its activity may be regulated by oestrogen.      

Effects of treatment with carnitines in infertile patients with prostato-vesiculo-epididymitis.

BACKGROUND: We have recently shown that patients with prostato-vesiculo-epididymitis (PVE) have a greater reactive oxygen species (ROS) overproduction than patients with prostatitis or prostato-vesiculitis. Since this biochemical stress persists even after treatment with antimicrobials, it may relate to an imbalance between pro- and anti-oxidant factors at the epididymal level. METHODS: To evaluate the effects of antioxidant treatment of patients with PVE, whether in the presence or absence of pro-oxidant factors, abacterial PVE infertile patients with normal (<1x10(6)/ml, group A, n = 34) or abnormal (>1x10(6)/ml, group B, n = 20) seminal white blood cell (WBC) concentrations received carnitines (L-carnitine 1 g and acetyl-carnitine 0.5 g twice/day) for 3 months followed by a wash-out period of 3 months. Semen parameters, ROS production and pregnancy outcome were evaluated before, during and following carnitine treatment. RESULTS: Carnitines increased sperm forward motility and viability in group A patients. This was associated with a significant reduction in ROS production which persisted during wash-out. Carnitines increased only the percentage of viable spermatozoa in group B patients. Within 3 months after the discontinuation of carnitines, the rate of spontaneous pregnancy in group A patients was significantly higher than that of group B patients, being 11.7% (4/34) compared with 0%. CONCLUSION: These results indicate that carnitines are only an effective treatment in patients with abacterial PVE and elevated ROS production when seminal WBC concentration is normal.     

Telomerase activity in human gynaecological malignancies.

AIM: To evaluate whether increased telomerase activity can be clinically useful for detecting malignant cells in a variety of gynaecological specimens. METHODS: Telomerase activity was examined in frozen tissue samples of histologically confirmed lesions of the endometrium, ovary, and cervix. It was also assessed in exfoliated cells in cervical smears from patients with premalignant and malignant lesions and in ascitic fluid obtained from cases with malignant or non-malignant ovarian tumours. RESULTS: Solid tissues from carcinomas were telomerase positive in all specimens of endometrial (6/6) and cervical (6/6) origin, and in almost all from the ovary (12/13). Normal tissues from the cervix (0/5) and the ovary (0/5) were telomerase negative, but samples from normal endometrium were found to show telomerase activity, possibly due to the cyclical regenerative nature of this tissue. Conversely, dissociated cells in cervical smears from preneoplastic and frankly neoplastic lesions rarely showed detectable telomerase activity. Thus smears from patients with malignant tumours were only positive in one of two patients, whereas those from CIN-2 (0/5) and CIN-3 (1/17) lesions and from normal (0/10) samples were almost all negative. Telomerase activity was also scarcely detectable in cells obtained from ascitic fluid from patients with ovarian tumours. CONCLUSIONS: As in many other organs, telomerase activity is increased in solid tissue specimens from malignant tumours of the female reproductive tract, but it is not yet a reliable indicator of the presence of exfoliated cancerous or precancerous cells in clinical specimens from such lesions. Interpretation should be guarded until more extensive studies have been conducted. The data on solid tissues presented here confirm that activation of this enzyme is a major hallmark of the neoplastic process.     

子宫内膜异位症不孕患者行辅助生殖技术的结果分析

目的分析子宫内膜异位症（EMs）不孕患者行辅助生殖技术（ART）的最优方案。方法对281例行ART的EMs不孕患者回顾性分析,观察各分期及各种用药方案的ART结局。结果Ⅱ、Ⅲ、Ⅳ期各组间行IVF超促排卵周期窦卵泡数目、Gn的剂量及用药时间、HCG日血清E2水平、内膜厚度、获卵数、成熟卵泡数、胚胎数、D1时2PN胚胎数、D3时1级胚胎数、妊娠率、累计妊娠率均无显著性差异（P〉0.05）。Ⅲ/Ⅳ期患者IVF超促排卵周期窦卵泡数目及HCG日内膜厚度各用药方案三组间无显著性差异（P〉0.05）。Gn的剂量及用药时间、HCG日血清E2水平、内膜厚度、获卵数、成熟卵泡数、胚胎数、D1时2PN胚胎数、D3时1级胚胎数、妊娠率、累计妊娠率,三组间差异均有统计学意义（P〈0.05）。Ⅲ/Ⅳ期长方案组Gn用量明显少于超长方案组;Gn时间超长方案组明显长于其他两组;获卵数、成熟卵泡数、胚胎数、D3时1级胚胎数短方案及拮抗剂方案明显少于其他两组,但在长方案中获得D1时2PN胚胎数明显高于其他两组;妊娠率及累积妊娠率由低到高依次为短方案及拮抗剂组、长方案组和超长方案组（P〈0.05）。结论Ⅰ/ⅡEMs患者促排卵及IUI数周期后不成功应积极行IVF治疗;超长方案是最适合EMs患者的IVF用药方案。     

Dominance,plasma testosterone levels,and testis size in house mice artificially selected for high activity levels

Male house mice (Mus domesticus) from four replicate lines selectively bred for high voluntary wheel-running behavior were compared with four random-bred control lines with respect to dominance, testis size, and plasma testosterone level. Behavior was measured with a tube apparatus in which focal mice encountered a standard opponent from an inbred strain, and positions of mice were scored over a 10-min period; the test was replicated the following day. Blood samples were taken from undisturbed mice 1 week prior to testing (baseline condition) and immediately after the first tube test; plasma testosterone was measured by enzyme immunoassay with chromatography. As compared with control lines, mice from selected lines tended to be smaller in body mass, to have larger testes, and were significantly less likely to advance towards their opponent during the second tube-test encounter. However, no significant differences in either baseline or post-encounter testosterone levels were detected. Significant differences in body mass, relative testis size, position during the first tube-test encounter, and baseline testosterone were found among the replicate lines within linetype, which indicates founder effects, random genetic drift, unique mutations, and/or multiple responses to selection. At the level of individual variation (residuals from nested analysis of covariance models), an inverse relationship between baseline testosterone and advancing in the tube test was observed, and the relationship was stronger during the second test day. This unexpected result may reflect an alternate coping strategy.     

Inconstant ascending testis as a potential risk factor for spermatogenesis in infertile men with no history of cryptorchism

The usual testicular location, either low or high in the scrotum, as well as testis ascent into suprascrotal position at least once a week from a usually scrotal position reported by the patient to occur spontaneously and regularly, were recorded in 85 fertile and 1014 infertile men, including 95 with a history of cryptorchism. The frequency of at least one testis being in a high scrotal location was similar in fertile (16.5%) and non-cryptorchid infertile (17%) men but higher in previously cryptorchid infertile men (27.2%), a difference probably due to cryptorchism. Testicular ascent was more frequent when scrotal location was high rather than low. An ascending testis was encountered more frequently in previously cryptorchid (30.4%) than in non-cryptorchid infertile men without any history of cryptorchism (18.3%) or in fertile men (11.8%). Moreover, in infertile men, spermatogenesis was more depressed in cases of testicular ascent than when both testes were never ascending, independently of a varicocele. Testis ascent could be a risk factor for spermatogenesis in infertile men without any history of maldescended testicle.      

组织端粒酶活性与宫颈癌相关研究

目的为了了解宫颈组织端粒酶活性与宫颈癌的关系.方法在30例宫颈癌、72例宫颈CIN和16例正常宫颈新鲜组织中,端粒酶重复序列扩增法(TRAP)用于检测组织端酶活性.结果3组端粒酶活性阳性分别有22例,21例和1例(P＜0.01),平均端粒酶活性分别为1.362±0.768、0.4236±0.247和0.048±0.026(P＞0.01).结论组织端粒酶活性的异常表达与宫颈癌进展密切相关,且随病程的进展端粒酶平均活性程度逐渐升高.