Antiproton stopping power in hydrogen below 120 keV and the Barkas effect.
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Journal Article↗
Biomedical subjects
L Santi
Publications and source records attributed to L Santi.
Ifosfamide plus epirubicin at escalating doses in the treatment of locally advanced and/or metastatic sarcomas.
A total of 46 consecutive patients were entered into this study to assess the efficacy and toxicity of an epirubicin/ifosfamide combination in treating locally advanced and/or metastatic adult sarcomas (38 soft-tissue sarcomas and 7 bone sarcomas in 45 evaluable patients). Epirubicin was given at escalating doses (from 50 to 100 mg/m2) as an intravenous (i.v.) bolus on day 1, and ifosfamide was given i.v. at 1.2 g/m2 daily on days 1-5. Cycles were repeated every 4 weeks. The overall response rate was 38% (17 of 45 patients), reaching 42% (16 of 38) in the soft-tissue sarcoma group and 44% (17 of 39) in patients who had not been treated previously. In all, 4 complete responses (CRs, 9%) and 13 partial responses (PRs, 29%) were obtained. Most responses (about 68%) were reached within the first 2 cycles. The high-dose intensity of epirubicin (P < 0.04), the histologic type (P < 0.03), the presence of metastatic lesions only (P < 0.01), and the lack of previous treatment (P < 0.04) were found to be positively correlated with the probability of response. The median duration of response was 8 months. The median survival period was 10 months for all evaluable patients and 21 months for those achieving CRs and PRs (P < 0.01). The tumor grade, performance status, and extent of disease at entry into the study correlated with survival. The treatment was well tolerated; no case of sepsis occurred, and neither acute nor cumulative cardiotoxicity was observed. Epirubicin in combination with ifosfamide is therefore effective in advanced and/or metastatic disease with acceptable toxicity. The activity of this combination as compared with that of either of the two drugs given alone at optimal doses needs to be evaluated in prospective randomized trials.
Adolescent↗
Molecular oncology: from basic research towards clinical application.
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Biomarkers, Tumor↗
Molecular Probe Database: a database on synthetic oligonucleotides.
The Molecular Probe Data Base (MPDB) is designed to collect and make available on-line information on synthetic oligonucleotides. This paper briefly describes the purpose of MPDB, its content and structure, forms and mode of data distribution, and a series of additional services available to scientists using MPDB.
Amino Acid Sequence↗
Doxorubicin (or epidoxorubicin) combined with ifosfamide in the treatment of adult advanced soft tissue sarcomas.
The results of the association of doxorubicin plus ifosfamide in the treatment of locally advanced and/or metastatic adult soft tissue sarcomas as reported in the literature from 1986 up to the present time are reviewed. The data confirm the effectiveness of the association doxorubicin plus ifosfamide, with an objective response rate of 33.25% (range, 22% to 42%), with 9.3% of complete responses. The highest percentages were reported in studies using doses of doxorubicin of 60 mg/m2 or higher, with a suggested dose-response correlation. The pattern is generally well tolerated, with a prevalently haematological toxicity. Results being equal, the use of epidoxorubicin seems to allow a lower incidence of high grade leukopenia, and an higher dose-intensity of the drug administered. The two randomized studies by EORTC and ECOG indicate superiority of this combination compared to doxorubicin on its own or with other polychemotherapeutic regimens containing doxorubicin, without ifosfamide. However, the actual contribution of ifosfamide deserves further investigation. The impact on long-term disease-free survival is, however, poor and median survival time ranges from 8 to 12 months in responder patients. Future studies should be aimed at increasing the dosages of the drugs without a significant increase of toxicity, by administering them in continuous infusion or by the use of growth factors.
Antineoplastic Combined Chemotherapy Protocols↗
Perilymphatic injections of recombinant interleukin-2 (rIL-2) partially correct the immunologic defects in patients with advanced head and neck squamous cell carcinoma.
Patients with advanced head and neck squamous cell carcinoma (HNSCC) are severely immunocompromised. In virtually all such patients who have been studied, reduced numbers of circulating CD3+ T-cell-receptor (TCR)alpha/beta+ T lymphocytes, a reduction of natural killer (NK) activity, and a poor induction of lymphokine-activated killer (LAK) cell activity (following in vitro treatment with recombinant interleukin-2 [rIL-2]) have been detected. Recently, however, it has been demonstrated that perilymphatic injections of low doses of rIL-2 may induce a local reduction of tumor masses in these patients. The present study, a cooperative pilot effort on the clinical effects of this route of administration, showed an activation of the lytic machinery in lymphocytes belonging to the T-cell lineage, as well as a potentiation of NK activity in the peripheral blood. These findings demonstrated that the severe immunodeficiency of HNSCC patients may be at least partially corrected by in vivo administration of rIL-2.
Aged↗
Tumor cell invasion inhibited by TIMP-2.
The 72-kd type IV collagenase is a member of the collagenase enzyme family that has been closely linked with the invasive phenotype of cancer cells. Previous studies have shown that both normal cells and highly invasive tumor cells produce the 72-kd type IV procollagenase enzyme in a complexed form consisting of the proenzyme and a novel tissue inhibitor of metalloproteinases, TIMP-2. The balance between activated enzyme and available inhibitor is thought to be a critical determinant of the matrix proteolysis associated with a variety of pathologic processes, including tumor cell invasion. In the present study, we demonstrate that alteration of the metalloproteinase-metalloproteinase-inhibitor balance in favor of excess inhibitor blocks human fibrosarcoma HT-1080 tumor cell invasion of a reconstituted basement membrane. The HT-1080 cell line produces both the 72-kd and the 92-kd type IV collagenases. Alteration of the type IV collagenase-inhibitor balance was achieved by addition of free TIMP-2 or antibodies to 72-kd type IV collagenase. Native, purified TIMP-2 was inhibitory in the range of 1-25 micrograms/mL. Addition of specific antiserum against the 72-kd type IV collagenase, which did not cross-react with the 92-kd type IV collagenase, inhibited HT-1080 cell invasion to the same extent. These results suggest that metalloproteinases, in particular the 72-kd type IV collagenase, are critical for tumor cell invasion of the reconstituted basement membrane. Our findings demonstrate that addition of the endogenous inhibitor TIMP-2 is able to block invasion. Thus, we recommend initiation of in vivo studies of the therapeutic potential of TIMP-2 to block tumor cell invasion and intravasation into the circulation.
Animals↗
In vitro effects of beta-carotene on human oral keratinocytes from precancerous lesions and squamous carcinoma.
Human keratinocytes, obtained from bioptic specimens of healthy and preneoplastic oral mucosa, and from human cell lines from oral cavity tumors (KB and SCC-25) were treated with beta-carotene (10 microM). The colony forming efficiency (CFE), the proliferation rate and the frequency of micronucleated cells were measured in these cultures. CFE was significantly reduced (p less than 0.05) by beta-carotene treatment in cells from healthy mucosa and in KB cells. Decreases (p greater than 0.05; NS) were also observed in cells from pathological mucosa and in SCC-25 cells. Cell proliferation rate was not substantially affected by beta-carotene in all cultures. Finally, a decreased frequency of micronucleated cells was found in treated cultures, but significant reductions (p less than 0.05) were only observed in cultures from oral mucosa (healthy and pathological) as well as in KB cell cultures. Our results indicate that beta-carotene is able to reduce the clonogenic activity (CFE), even if it does not seem to influence cell proliferation, and that it has a protective effect against genotoxic damage.
Adolescent↗
Inelastic proton scattering from Pt isotopes and the interacting boson model.
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Journal Article↗
Anandron (RU 23908) in metastatic prostate cancer: preliminary results of a multicentric Italian study.
Between March 1986 and March 1987, 48 patients with stage D prostate carcinoma were entered into a multicentric pilot study using the pure nonsteroidal antiandrogen nilutamide (Anandron--RU 23908) at the dose of 100 mg t.i.d. as the only therapy until disease progression or the occurrence of toxicity. Minimum follow-up was 15 months. Median age of patients was 72 (56 to 83) and median initial Performance Status (PS) was 1 (0 to 3). Of the 48 patients, 29 were untreated, while 19 patients were progressing following treatment by orchiectomy, LHRH analogs, or other endocrine therapies. According to the National Prostatic Cancer Project (NPCP) criteria, 43 patients were evaluable for response. Overall best response in untreated patients was partial response (PR), 41.6%; stationary disease (SD), 54.1%; 73.6% of pretreated patients achieved SD. Median progression-free survival and overall survival in untreated patients were 325 and 696 days, respectively, and 174 and 447 days, respectively, in pretreated patients. The more common side effects were G.I. toxicity (65%), hemeralopia (27%), and alcohol intolerance (6.2%). Results of this study suggest that Anandron may be a safe and effective treatment for patients with advanced prostatic cancer.
Aged↗
Anti-smoking messages during military service.
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Adolescent↗
Molecular epidemiology of cancer in immune deficiency.
Molecular epidemiology may help fill the gap between epidemiological and biological models for cancerogenesis, allowing useful comparisons between series of cases carrying different biological characteristics. The defective regulation of immune responses is probably the common basis of cancer origin in genetically determined immune deficiency (GDID). Lymphomas are the most common neoplasms, showing an extremely high incidence in early age, frequent unusual location (extra-nodal) and histology, and rapid progression and spread with little response to therapy. A high incidence of lymphoma is also found in acquired (AIDS) or iatrogenic (transplant recipients) immune defective patients. The emergence of a malignant clone may be linked to unregulated polyclonal B- or T-cell proliferation and to disturbances in chromosomal rearrangements and in clonal selection, which are unique features of the immune cells regulation. It is useful to compare patterns of malignancies observed in GDIDs and in chromosomal breakage syndromes (CBS). In ataxia-teleangectasia (AT), selective errors at sites of special recombination involved in immune cell rearrangements may account for both immune deficiency and frequent types of malignant transformation. Different cytogenetic alterations and different types of malignancies are more common in Bloom syndrome, and in other GDIDs unrelated to chromosomal fragility, possibly due to different regulatory impairments. Viral infection (EBV, HPV, CMV) is likely to be a factor in any of the above steps. Therefore, individual exposure to viral (or other environmental) agents may be related to frequent location (skin, ano-genital areas, digestive tracts) of nonlymphatic cancers both in some GDIDs and in acquired or iatrogenic immune deficiencies. Cells that are homozygous for GDID are not malignant themselves, but are more likely to undergo new mutations to malignancy, due both to disregulation of the immune system and to environmental agents.
Humans↗
Lack of correlation between alkaline DNA fragmentation and DNA covalent binding induced by polychloroethanes after in vivo administration. Problems related to the assessment of a carcinogenic hazard.
The DNA-damaging activity of polychloroethanes was tested in mouse liver by the fluorometric assay of DNA unwinding. With the exception of 1,2-dichloroethane, all components of this chemical class had negative results. The failure of the parameter alkaline "DNA fragmentation" to detect the DNA-damaging activity of polychloroethanes is in sharp contrast with the measurement of DNA covalent binding, another short-term parameter of genotoxicity. Since covalent DNA adducts appear to be quantitatively well correlated with the oncogenic potencies of chloroethanes in liver, the negative results obtained with the present method can perhaps be explained in terms of quality of DNA adducts; these may be incapable of producing DNA breaks or alkali-labile sites detectable as alkaline DNA fragmentation. It is however worth noting that carcinogenicity of chloroethanes appears to depend not only on DNA damaging capability, but also on promoting activity during the carcinogenic process.
Alkalies↗
Tumor progression by DNA flow cytometry in human colorectal cancer.
We wished to better understand the role of aneuploidy during the progression of human colorectal cancer. Fresh or frozen multiple samples from 221 human colorectal adenomas, 93 carcinomas, and corresponding control mucosa were investigated using high-resolution DNA flow cytometry. A total number of 164 DNA abnormal clones were observed and characterized by a quantitative index of DNA aneuploidy (DI). In precancerous lesions the vast majority of DNA abnormal clones (almost 3/4 in adenomas with mild to moderate dysplasia) was hypo- and hyper-diploid with DI values from 0.8 to 1.2 (near-diploidy). In moderately to poorly differentiated carcinomas the vast majority of abnormal clones was near-triploid and hypotetraploid with DI values from 1.4 to 1.8 (near hypertriploidy) and only 12% were near-diploid. Adenomas with foci of carcinomas, a group of special interest since they represent a link in colorectal tumor progression, had median triploid DNA content. In addition to an increase in DI values, the carcinomas had a clear increase in the proportion of cells actively synthesizing DNA (S-phase fraction). These results are interpreted as evidence for a ploidy-evolution model according to which near-diploid clones in adenomas at early stages of dysplasia would derive from abnormal mitotic cells that divide their DNA unequally between two daughter cells. Tetrapolidization of these near-diploid cells and successive DNA loss would then lead in later stages of tumor progression to near-hypertriploid clones characterized by a balance of chromosomes bearing growth-promoting and growth-suppressing genes confering a selective proliferative advantage.
Adenoma↗
Mutagenic and carcinogenic potency indices and their correlation.
We have analyzed a significant number of studies existing in the literature, in which the ability of different short-term tests for predicting carcinogenicity in rodents was investigated. We have separated these studies into two groups. In the better known group of studies, qualitative predictivity was investigated (sensitivity and specificity). In the second group of studies (analyzed in greater detail), positive results were examined for the correlation between carcinogenic potency and potency of response in a given short-term test. There is substantial agreement between qualitative and quantitative predictivity; both appear to be situated between a low and moderate level. We have analyzed the interesting possibility of using the quantitative approach not only for positive data but for combined positive and negative data as well. We have stressed that short-term tests of genotoxicity should be asked to predict only initiation and irreversible alterations in the genome and not to predict a combination of these events, including promotion and modulation of differentiation. Even with regard to only initiation, genotoxicity data should be related to comparative metabolism, as well as to considerations of the significance of different end points and structure-activity relationship data. In conclusion, the information coming from short-term tests of genotoxicity is probably useful but should be used in conjunction with other types of information and only for predicting one particular class of events in the entire process of carcinogenesis.
Carcinogenicity Tests↗
Chemotherapy versus tamoxifen versus chemotherapy plus tamoxifen in node-positive, estrogen receptor-positive breast cancer patients: results of a multicentric Italian study. Breast Cancer Adjuvant Chemo-Hormone Therapy Cooperative Group.
Between November 1, 1983 and June 30, 1987, 510 node-positive, estrogen receptor (ER)-positive breast cancer patients have been randomly allocated to receive either chemotherapy (six intravenous [IV] cyclophosphamide, methotrexate, and fluorouracil [CMF] courses followed by four IV epirubicin courses) or 5 years of tamoxifen treatment or a combination of both therapies. After a median follow-up of 40 months, patients receiving the combined treatment achieved the best results, and those treated with chemotherapy alone achieved the worst, the difference being particularly evident in postmenopausal women. However, while the concurrent use of chemotherapy and tamoxifen did improve the results achieved by chemotherapy alone, particularly in postmenopausal women and in those with four or more involved nodes, it did not significantly improve the results achieved by tamoxifen alone, particularly in patients with higher ER tumor concentrations. Side effects were more numerous and more severe in patients receiving chemotherapy (with or without tamoxifen). Our findings, although still preliminary, confirm that tamoxifen should be the treatment of choice for postmenopausal breast cancer patients with node-positive, ER-positive tumors. In addition, the findings suggest that tamoxifen may represent a safe alternative to chemotherapy (at least to the cytotoxic regimen we used) for younger women, provided they have ER-positive tumors. In patients with ER-positive tumors, the addition of chemotherapy to tamoxifen does not seem to improve significantly the effectiveness of tamoxifen alone.
Adult↗
Quantitative predictability of carcinogenicity of the covalent binding index of chemicals to DNA: comparison of the in vivo and in vitro assays.
The capability of covalent binding to DNA to predict the initiating potential of chemical carcinogens was compared for the assays performed in vivo (rodent liver DNA) and in vitro (purified DNA incubated in the presence of mouse and rat liver microsomes). A quantitative correlation between DNA adducts and carcinogenic potency was investigated. The in vivo assay appeared slightly, but not significantly, more predictive than the in vitro assay. Also predictivity was slightly higher both in vivo and in vitro when we referred to liver carcinogenicity instead of overall carcinogenicity. The predictive ability found for DNA covalent binding (both in vivo and in vitro) was similar to that of many short-term tests (such as mutagenicity, DNA damage/repair, SCEs, and cell transformation tests). The covalent DNA binding, measured after incubation with DNA in vitro in the presence of liver microsomes, could therefore be a reasonable short-term test offering greater rapidity of execution and requiring the sacrifice of fewer animals than the corresponding in vivo test.
Animals↗