Biomedical subjects

Kurt Miller

Publications and source records attributed to Kurt Miller.

40 records · Page 3Linked to original sources

PubMed2002

Cyclin A1 and gametogenesis in fertile and infertile patients: a potential new molecular diagnostic marker.

BACKGROUND: The study aim was to evaluate cyclin A1 mRNA expression levels as a potential molecular diagnostic parameter in the work-up of testicular tissue from fertile versus infertile patients. METHODS: Cyclin A1 expression was quantified in 55 cryopreserved testicular tissue specimens by fluorescence real-time RT-PCR. A conventional histological work-up was performed concomitantly in all tissue specimens with additional semi-thin sectioning in all cases of non-obstructive azoospermia (n = 12), maturation arrest (n = 17) and Sertoli cell-only syndrome (SCOS; n = 9). RESULTS: The mean (+/- SD) normalized cyclin A1 expression (N(CyclinA1)) was 3.82 +/- 2.23 relative gene expression (RGE) in tissue specimens with normal spermatogenesis, and 0.625 +/- 0.221 RGE in those with maturation arrest at the level of early spermatids. Only minimal N(CyclinA1) was detected in tissue specimens with spermatogonia only or maturation arrest at the level of primary spermatocytes (0.005 +/- 0.008). Cyclin A1 expression was absent in the majority of SCOS specimens (0.002 +/- 0.002). CONCLUSIONS: These investigations suggested that cyclin A1 expression is altered in cases of spermatogenic disorders. Moreover, the level of cyclin A1 mRNA expression correlates with gametogenic disorders and seems well suited for a molecular-diagnostic classification supplementing the histopathological evaluation of spermatogenic disorders.

Biomarkers↗

PubMed2002

Testicular sperm extraction in azoospermic patients with gonadal germ cell tumors prior to chemotherapy--a new therapy option.

BACKGROUND: In view of the high cure rates in patients with testicular germ cell tumors (TGCT), increasing clinical importance is attached to protection of fertility. Long-term infertility due to cytostatic therapy may be expected in more than 50% of the patients at a cumulative dose of cisplatin > 0.6 g/m2. The standard procedure for fertility protection in cancer patients includes cryopreservation of ejaculated spermatozoa. Considering that some patients have tumor-induced azoospermia, we examined the usefulness of testicular sperm extraction before therapy. METHOD: A survey of the literature served as a basis for investigating biological and clinical aspects of the impact of chemotherapy on male fertility. A study of our patient population also enabled us to explore the option of extracting sperm from the contralateral healthy testis prior to treatment in 14 azoospermic patients with testicular germ cell tumors. RESULTS: We were able to successfully recover haploid germ cells in 6/14 testicular biopsies from azoospermic patients with testicular germ cell cancer prior to treatment. Maturation arrest was found in 3/14 cases and Sertoli-cell-only syndrome in the rest. None of the patients had secondary healing or a treatment delay because of the testicular biopsy. CONCLUSION: Since the post-therapeutic fertility status is difficult to predict in cancer patients, we think that TESE should be regarded as a general option prior to cancer treatment and offered to azoospermic cancer patients. New guidelines should be established in this connection.

Antineoplastic Agents↗

PubMedDate not supplied

Molecular staging of pelvic surgical margins after radical prostatectomy: comparison of RT-PCR for prostate-specific antigen and telomerase activity.

The further course of prostate cancer (PC) after radical prostatectomy (RPX) is decisively influenced by the local tumor stage. Although it is now possible to assess the risk of local recurrence from the histopathology, precise predictions cannot be made. A more accurate evaluation would be desirable, mainly for early planning of adjuvant therapy. We assessed the detection of telomerase activity using the Telomeric Repeat Amplification Protocol in surgical margins compared to RT-PCR-supported prostate-specific antigen (PSA) mRNA detection and conventional histopathological examination. We examined 95 patients with local PC during RPX and 16 patients with muscle-invasive transitional bladder cancer who underwent radical cystectomy. After RPX or RCX biopsies were obtained from 4 or 3 defined areas of the prostatic fossa and processed by TRAP assay for telomerase activity and by RT-PCR for PSA using a standard protocol. Five of 48 patients (10.4%) with organ-confined prostate cancer (pT2) and 7 of 47 patients (14.9%) with locally advanced PC (>pT2) had positive detection of telomerase activity in at least one positive specimen. In contrast to RT-PCR for PSA mRNA and histological findings for organ-confined and locally advanced disease, detection of telomerase activity yielded no statistically significant correlation to clinical parameters. Only PC-patients with positive histopathological margins had a positive correlation between detection of telomerase activity and high Gleason scores (r=0.65, p=0.022). Based on the results obtained and the current state of knowledge, measurement of telomerase activity must be considered less sensitive than RT-PCR for PSA mRNA in surgical margins, although tumor specificity should theoretically be higher. It is not even sure at the present time whether a combination of both methods offers any recognizable advantage over PSA mRNA detection alone. The value of the results obtained in this study will have to be assessed in a further follow-up to determine whether patients with positive molecular detection have an increased risk of local recurrence.

Aged↗

PubMedDate not supplied

Quantification of human telomerase reverse transcriptase mRNA in testicular germ cell tumors by quantitative fluorescence real-time RT-PCR.

Telomerase is a ribonucleoprotein enzyme which is endogenously expressed in germ, stem and tumor cells, but absent in benign somatic cells. The two major telomerase components are human telomerase RNA (hTR) and human telomerase reverse transcriptase (hTERT). It has been shown that hTERT is rate-limiting for telomerase activity and that it plays a central role in human carcinogenesis. Here, we investigated the potential of hTERT and hTR gene expression as diagnostic markers in testicular germ cell tumors (TGCT). hTERT mRNA and hTR expression were quantified in 55 testicular germ cell tumors comprising 36 primary and 19 germ cell tumors from retroperitonal sides by fluorescence real-time RT-PCR using the LightCycler technology. Porphobilinogen deaminase (PBGD) was used as housekeeping gene and to enable relative quantification. For comparison to TGCTs, 38 benign testicular biopsies from patients with fertility disorders were assayed. hTERT expression was detected in all examined undifferentiated TGCTs and in the benign testicular tissue specimens with germ cell content (N(hTERT) 38-127). In contrast, mature teratomas from primary and post-chemotherapy masses, which are characterized by well-differentiated tissue components showed a nearly complete downregulation of hTERT expression (N(hTERT) 2-4, p<0.001). hTR levels however, were high in all tumors and independently of the presence of germ cells also in the benign tissue control group. hTERT mRNA is expressed in all undifferentiated TGCTs but repressed in mature teratomas. This suggests an inverse correlation between the differentiation status of germ cell tumors and hTERT expression. Thus, detection of hTERT expression in tumors histopathologically classified as mature teratomas enables a molecular-diagnostic confirmation and might aid decision making for treatment of patients presenting with this tumor subtype.

Age Factors↗