Biomedical subjects

T Dimopoulos

Publications and source records attributed to T Dimopoulos.

6 recordsLinked to original sources

PubMed2001

A combination therapy of dexamethasone and somatostatin analog reintroduces objective clinical responses to LHRH analog in androgen ablation-refractory prostate cancer patients.

We evaluated whether the combination of triptorelin, a LHRH analog (LHRH-A), with dexamethasone and lanreotide, a somatostatin analog, can produce objective clinical responses in metastatic androgen ablation-refractory prostate cancer (stage D3) patients who have relapsed, after combined androgen blockade (LHRH-A plus antiandrogen) and antiandrogen withdrawal. Eleven stage D3 patients with diffuse bony metastases, who had progressed despite initial responses (lasting <12 months) to combined androgen blockade therapy and subsequently failed antiandrogen withdrawal, received oral dexamethasone (4 mg daily for the first month, tapered down to 2 mg after the first month and 1 mg after the second month, and continued on 1 mg thereafter) and lanreotide (30 mg im every 14 d) in combination with triptorelin (3.75 mg im every 28 d). Serum prostate-specific antigen, alkaline phosphatase, performance status, and bone pain were assessed monthly during therapy. Fasting blood glucose was measured biweekly, and serum IGF-I, T, and dehydroepiandrosterone sulfate levels were assessed at baseline, at response to the combination therapy, and at relapse from it. Ten of 11 stage D3 patients [90.9% of patients; 95% confidence interval (CI), 58.7-99.8%] had durable objective clinical responses (including > or = 50% prostate-specific antigen decline in 8 patients, 72.7%; 95% CI, 39-94%). All patients reported significant and durable improvement of bone pain (for a median duration of 13 months; 95% CI, 12-14 months; range, 6-22 months) and performance status (median duration, 19 months; 95% CI, 13-25 months; range, 7-22 months) without major treatment-related side effects. The median progression-free survival was 7 months (95% CI, 4-10 months; range, 3-17 months), and the median overall survival was 18 months (95% CI, 16-20 months; range, 7-22 months). Five of six total deaths occurred secondary to disease progression. We observed a statistically significant (P = 0.018) reduction in serum IGF-I levels at response to the combination therapy (60% reduction of baseline IGF-I levels). Dehydroepiandrosterone sulfate levels, although already significantly suppressed at baseline, had an additional significant reduction (P < 0.02) at response to therapy. T levels remained suppressed within castration levels (<3 nmol/liter, at baseline and throughout therapy, including relapse). The combination therapy of LHRH-A with dexamethasone plus somatostatin analog produces objective clinical responses and symptomatic improvement in androgen ablation (LHRH-A) refractory prostate cancer patients.

Aged↗

PubMed2000

Tunneling phenomena as a probe to investigate atomic scale fluctuations in Metal/Oxide/Metal magnetic tunnel junctions

Local transport properties of Al2O3 tunnel barriers have been investigated at a nanometric spatial scale with an unconventional near field microscope. Using the tunneling effect, which is extremely sensitive to fluctuations of the barrier parameters (less than 1 to 2 A), a unique method is introduced to investigate the tunnel barrier quality. This technique provides atomic scale information on the barrier characteristics which cannot be obtained by conventional surface analysis techniques since they are all subject to averaging over surface and depth.

Journal Article↗

PubMed2000

The significance of PSA/IGF-1 ratio in differentiating benign prostate hyperplasia from prostate cancer.

The importance of insulin-like growth factor 1 (IGF-1) in human serum for the early diagnosis of prostate cancer is controversial. The IGF-1/PSA ratio may improve the performance of prostate specific antigen (PSA) as a prostate cancer marker. IGF-1, along with PSA and free PSA concentration, was measured in the serum of 34 patients with prostate cancer and in 131 patients with benign prostatic hyperplasia (BPH). Although IGF-1 concentration did not significantly differ between the groups, PSA/IGF-1 ratio could clearly distinguish the two groups. In patients with cancer but not in patients with BPH, IGF-1 concentration correlated with PSA and free PSA. The values of PSA and free PSA correlated with each other for both groups. Receivers Operating Curve (ROC) analysis indicated a better sensitivity to specificity ratio for PSA/IGF-1 than for PSA or Free/Total (F/T) PSA.

Adenocarcinoma↗

PubMed1999

Novel concept of antisurvival factor (ASF) therapy produces an objective clinical response in four patients with hormone-refractory prostate cancer: case report.

BACKGROUND: Osteoblasts and osteoblast-derived survival growth factors, such as insulin-like growth factor I (IGF I), inhibit chemotherapy apoptosis of prostate cancer cells, thereby producing cytotoxic drug-resistant tumor growth, in vitro. METHODS: We tested a novel therapeutic approach, referred to as antisurvival factor (AFS) therapy, that aimed at reduction of osteoblast-derived IGFs, using dexamethasone (4 mg per os, qD) and growth hormone (GH)-dependent liver-derived IGFs, using a somatostatin-analog (lanreotide, 30 mg, intramuscularly (i.m.), q14D) in combination with triptorelin (3.75 mg, intramuscularly, q28D) to produce a clinical response in 4 patients with progressing hormone-refractory prostate cancer. RESULTS: The patients given ASF therapy exhibited an excellent improvement of clinical performance and a decline of prostate-specific antigen (PSA) within 2 months of ASF therapy. One of them experienced excellent clinical response (normalization of PSA), two experienced good clinical response (decline of PSA of more than 50%), and one experienced stabilization (decline of PSA of less than 50%). CONCLUSIONS: We conclude that this novel concept of combination therapy, using ASF with hormone ablation, is a promising salvage therapy that should be further assessed with a randomized clinical trial.

Aged↗

PubMed1992

The ultrastructure of the noninvolved urothelium of tumor-bearing patients before and after interferon treatment.

The ultrastructural morphology of the noninvolved urothelium of tumor-bearing patients before and after interferon-alpha 2b (IFN-alpha 2b) treatment was investigated. The ultrastructure of the normal bladder urothelium has been reported. The noninvolved urothelium of our patients already showed deviation from the normal. At the end of therapy, we noted a partial restoration of the urothelium to its normal morphology with the reestablishment of some of its normal features, i.e., a well-developed Golgi apparatus, the existence of parts of the asymmetric unit membrane, and the appearance of nuclear bodies. Prevention of tumor recurrence by restoring the ultrastructural morphology of the noninvolved urothelium with IFN-alpha 2b is a subject worthy of further investigation.

Aged↗

PubMedDate not supplied

Conversion of nested reverse-transcriptase polymerase chain reaction from positive to negative status at peripheral blood during androgen ablation therapy is associated with long progression-free survival in stage D2 prostate cancer patients.

BACKGROUND: Nested reverse-transcriptase polymerase chain reaction (nested rt-PCR) for the detection of mRNA of prostate specific antigen (PSA) and prostate specific membrane antigen (PSMA) in peripheral blood samples (PB) and bone marrow biopsies (BM) can assess the extraprostatic growth of prostate cells. MATERIALS AND METHODS: Nested rt-PCR for PSA and PSMA at PB and BM was performed (a) at diagnosis, (b) after 6 months from the initiation of combined androgen blockade [(CAB); triptorelin 3.75 mg, i.m., q28 days plus flutamide 250 mg, per os, tid] and, (c) at progression to androgen refractory stage in 28 patients with newly-diagnosed stage D2 prostate cancer. RESULTS: At diagnosis, all patients were found to be rt-PCR positive for PSA and PSMA at BM while 7 (25%) were rt-PCR negative for PSA and PSMA at PB. Nine out of 21 patients with rt-PCR-positive status have converted to rt-PCR-negative status at PB during CAB while they remained rt-PCR-positive at BM. The rt-PCR-negative status at PB during CAB was associated with progression-free survival >12 months (p=0.029). At progression to androgen refractory stage all but 2 patients were rt-PCR-positive at PB for PSA and PSMA, among them 3 who were rt-PCR-negative at diagnosis. CONCLUSION: Our data suggest that conversion to rt-PCR-negative status at PB for PSA and PSMA during objective clinical response to CAB is associated with long progression-free survival in stage D2 disease.

Androgen Antagonists↗