Temozolomide and interferon-alpha in metastatic melanoma: a phase II study of the Italian Melanoma Intergroup

Temozolomide (TMZ) is a new oral alkylating agent which has proven to be as active as dacarbazine (DTIC) in the treatment of melanoma, but with a lower toxicity. A multicentric phase II trial was conducted in an out-patient setting to determine the therapeutic activity and safety of TMZ in combination with interferon-alpha (IFN-alpha). From June 2000 to July 2001, 41 patients were recruited to receive TMZ 200 mg/m orally on days 1-5 every 28 days and with 5 MU IFN-alpha subcutaneously three times a week, continuously for eight cycles or until disease progression occurred. Of the 40 treated patients, two complete responses (5%) and three partial responses (7.5%) were observed, with a median duration of 4 months (range, 1.5-13.5 months). Thirteen patients (32.5%) had stable disease for a median of 2.5 months. Time to progression was 2.6 months and the median overall survival was 11.8 months. Nine patients (22.5%) developed brain metastases. The grade 4 toxicity observed in seven patients was of a transient haematological nature. This combination therapy is well tolerated but does not appear to increase the response rate or overall survival with respect to TMZ alone or to chemotherapeutic regimens. Further and more complex associations of these two drugs could be investigated in specific subsets of patients, in particular to evaluate its real efficacy in preventing brain metastases.     

Transforming growth factor-beta released by PPD-presenting malignant mesothelioma cells inhibits interferon-gamma synthesis by an anti-PPD CD4+ T-cell clone

Besides acting complexly on both normal and tumor cells, transforming growth factor-beta (TGF-beta) can determine the nature of the response to the antigen, strongly inhibiting the differentiation of naive CD4+ T-cells toward a T helper-1 (Th-1) phenotype; in a number of experimental models, TGF-beta also appeared to be a potent immunosuppressant factor. TGF-beta was shown to be released by some human malignant mesothelioma (MMe) cells, which affects the immune response to this tumor. Thus, for a better understanding of the role of TGF-beta in the immune response to MMe cells, we evaluated the production of a Th-1 cytokine (IFN-gamma) and of a Th-2 cytokine (IL-4), following Purified Protein Derivative (PPD) recall antigen presentation by human MMe cells to a class-II major histocompatibility complex (MHC-II)-matched PPD clone (PPD clone). Our data confirm that human MMe cells possess the unusual capability of presenting a common recall antigen to CD4+ lymphocytes but also show that these tumor cells can abrogate Th-1 immune response, as evidenced by a shift in favor of the production of IL-4 over that of IFN-gamma, through a TGF-beta-mediated pathway; only the simultaneous block of TGF-beta1 and beta2 effects can significantly restore a typical Th-1 pattern of cytokine production by PPD clone in response to PPD presentation by MMe. Even though the role of TGF-beta in the promotion of MMe growth should be further and better defined, this effect should be considered when designing new therapeutical approaches aimed at improving the immune response to MMe.     

Allelic variants of natriuretic peptide receptor genes are associated with family history of hypertension and cardiovascular phenotype

OBJECTIVE: Abnormalities in the natriuretic peptide system could play a key role in the genesis of hypertension. We evaluated the associations between a family history of hypertension, cardiovascular phenotype and allelic variants of Npr1 and Npr3, two candidate genes that codify for natriuretic peptide receptors. METHODS: We genotyped 45 young normotensive subjects (19 males, 26.8 +/- 3.7 years) with accurately assessed family history of hypertension (FH+) and 52 (26 males, 26.1 +/- 3.1 years) without (FH-) for the known variants of Npr1 and Npr3 genes, and for a novel length difference (3C/4C) polymorphism at position 15129 in the 3'-untranslated region of the Npr1 gene. Blood pressure, echocardiography and plasma brain natriuretic peptide were assessed. RESULTS: Both the novel Npr1 3C allele (59 versus 33%, P < 0.001) and the 3C/3C genotype (31 versus 8%; P < 0.001) were significantly more frequent in FH+ than in FH-. The inverse distribution of the 4C/4C genotype suggested that a casual association was very unlikely. Moreover, the 3C/3C homozygous had significantly higher systolic blood pressure (121.1 +/- 6.3 versus 115.6 +/- 7.8 mmHg in 4C/4C; P < 0.05) and a longer left ventricular isovolumic relaxation time (67 +/- 10 versus 61 +/- 9 ms; P < 0.05). The Npr3 C(-55) allele variant was also more frequent in FH+ (88 versus 76%, P < 0.05), but was not associated with the cardiovascular phenotype. CONCLUSIONS: The novel Npr1 gene 3C variant and the Npr3 gene C(-55) allele are associated with hypertensive family history. Moreover, the functional Npr1 3C variant, when homozygous, is also associated with higher systolic blood pressure and prolonged ventricular relaxation.     

Phenotypic effects of expanded ataxin-1 polyglutamines with interruptions in vitro.

Spinocerebellar ataxia type 1 is a neurodegenerative disease caused by expansion of an uninterrupted glutamine repeat in ataxin-1 protein. Protein aggregation and immunoreactivity to 1C2 monoclonal antibody are two distinct pathognomonic features of expanded ataxin-1, as well as of other polyglutamine disorders. Rare cases of non-affected elderly subjects carrying expanded ataxin-1 alleles were found in random population. However, in these alleles the glutamine stretch was interrupted by histidines. Due to lack of phenotype, these alleles should be considered "normal". Most importantly, occurrence of these unusual alleles provides a unique opportunity to investigate which molecular properties of expanded ataxin-1 are not coupled to polyglutamine pathogenesis. Towards this goal, we compared in vitro the immunoreactivity to 1C2 antibody and the ability to form aggregates of interrupted and uninterrupted alleles. Immunoblotting showed that expanded-interrupted ataxin-1 had an affinity to 1C2 resembling that of normal ataxin-1. On the contrary, filter assay showed that aggregation rate of expanded-interrupted ataxin-1 resembles that of expanded-uninterrupted ataxin-1. These observations indicate that affinity for 1C2 does not directly correlate with self-aggregation of ataxin-1. Moreover, self-aggregation is not directly affected by histidine interruptions. In conclusion, these results support the hypothesis that mechanisms underlying neuronal degeneration are triggered by protein misfolding rather than by protein aggregation.     

An outbreak of acute schistosomiasis at Porto de Galinhas beach, Pernambuco, Brazil

We recently confirmed several cases of acute schistosomiasis in Porto de Galinhas beach, Northeast Brazil. A total of 662 patients were diagnosed by parasitological and clinical examinations. The infection likely occurred during the September 7 national holiday, when heavy rainfall flooded the Ipojuca River and people were infected when the water covered their yards. Families were continuously exposed to infection for a period of three weeks until the water had completely dried up. Previous investigation suggests that snail vectors were introduced as a result of landfill in marshy areas. The swamp-flooding of such areas facilitated the emergence of slums surrounded by snail breeding sites. Heavy rainfall caused open-air sewage ditches to overflow, allowing for infection of snails by Schistosoma mansoni. Thus, continuous floods were responsible for the spread of human infection. Clinical and laboratory results identified 62% of acute cases of S. mansoni. Complementary studies are being conducted to define the impact and epidemiological meaning of the acute schistosomiasis outbreak.     

Mitoxantrone, L-leucovorin and 5-fluorouracil: an effective and well tolerated first-line treatment for advanced breast cancer

AIMS AND BACKGROUND: The combination of mitoxantrone plus leucovorin/fluorouracil in heavily pretreated patients with advanced breast cancer has shown significant activity and extremely good tolerability. The aim of this study was to evaluate the activity of this combination in patients not previously submitted to chemotherapy. METHODS: From May 1993 to December 1995 we treated 80 patients with advanced breast cancer with a combination of mitoxantrone, l-leucovorin and 5-fluorouracil. All patients had histologically or cytologically proven breast cancer, WHO performance status 0-3, normal hematological parameters and normal serum bilirubin. Prior chemotherapy for metastatic disease was not allowed, whereas adjuvant CMF (cyclophosphamide, methotrexate and 5-fluorouracil) or adjuvant anthracycline (doxorubicin or epirubicin) therapy was allowed; a single prior hormone treatment was permitted. Chemotherapy consisted of mitoxantrone 12 mg/m2 i.v. day 1, l-leucovorin 150 mg/m2 i.v. days 1, 2 and 3 and 5-fluorouracil 350 mg/m2 i.v. days 1, 2 and 3. The courses were repeated every 3 weeks. RESULTS: Objective response (CR + PR) was observed in 46/80 (57%) patients (95% CI, 46%-68%). Complete response (CR) was observed in 21/80 cases (26%). Response was observed in 14/24 (58%) patients with soft tissues as the dominant site of disease, in 22/34 (65%) patients with visceral involvement and in 10/22 (45%) of those with bone as the dominant site of disease. The median duration of response and survival was 9 months (range, 3-16) and 22 months (range, 2-48+), respectively. Toxicity was very manageable, with grade 4 leukopenia and thrombocytopenia in 6/80 (7.5%) and 1/80 (1.25%) patients, respectively, and negligible non-hematological toxicity. CONCLUSIONS: The combination of mitoxantrone, 5-fluorouracil and high-dose l-leucovorin is a safe and effective regimen for first-line treatment of advanced breast cancer.     

Encapsulation of adriamycin in human erythrocytes.

Adriamycin (doxorubicin) was encapsulated in human erythrocytes by means of a dialysis technique involving transient hypotonic hemolysis followed by isotonic resealing. Up to 1.6 mg of the drug was entrapped per ml of packed erythrocytes, with the efficiency of encapsulation being 60-80%. In vitro incubation of the Adriamycin-loaded erythrocytes in autologous plasma was accompanied by progressive release of unaltered Adriamycin in the medium. The efflux was still evident after 50 hr. The metabolism of encapsulated Adriamycin was restricted to limited formation of the C-13 hydroxylated metabolite, adriamycinol, in the normal erythrocytes but not in erythrocytes from individuals deficient in glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP+ 1-oxidoreductase, EC 1.1.1.49) activity. Reductive bioactivation of encapsulated Adriamycin to yield the corresponding aglycones was not observed in a variety of conditions. However, when NADPH ferredoxin reductase and ferredoxin, both purified from spinach leaves, were co-entrapped within erythrocytes and allowed to catalyze electron transfer to Adriamycin intracellularly under N2, a quantitative conversion to 7-deoxyadriamycin aglycone was obtained. Adriamycin-loaded erythrocytes did not show any significant oxidative damage, except for a variable increase of methemoglobin, suggesting some redox cycling between native Adriamycin and its semiquinone radical. Encapsulation of Adriamycin in autologous human erythrocytes may represent a therapeutic strategy for the slow release in circulation of this antineoplastic drug in order to reduce or prevent its adverse effects and especially the delayed cardiotoxicity that limits its use in patients with neoplastic disease.     

Intra-periaqueductal grey microinjections of an imidazo[1,2-b]pyridazine derivative, DM2, affects rostral ventromedial medulla cell activity and shows antinociceptive effect

The 6-methoxy-2-phenylimidazo[1,2-b]pyridazine-3-carboxylic acid, DM2, exerts anti-absence activity and blocks Cav3.1 channel, a T-type voltage-dependent Ca²⁺ channel subtype, in vitro. The current study investigated the effect of intra-ventrolateral periaqueductal grey (VLPAG) administration of DM2 on formalin-induced nocifensive responses in rats. In addition, the effect of intra-VLPAG microinjection of DM2 on the ongoing and tail flick-related activities of rostral ventromedial medulla (RVM) cell population was also investigated. Formalin was injected subcutaneously into the dorsal surface of the hind paws of awake rats. We found that DM2 reduced nocifensive responses in the late phase of the formalin test. Moreover, in the RVM, the intra-VLPAG microinjection of DM2 reduced the ongoing and tail flick-related activity of the nociceptive ON cells, whereas it increased the ongoing activity and reduced the tail flick-induced pause of the antinociceptive OFF cells, consistent with antinociception. Behavioural and electrophysiological effects were reproduced by intra-VLPAG microinjection of ethosuximide, a conventional T-type Ca²⁺ channel blocker. Finally, DM2 administration did not produce any adverse cardiovascular effects as blood pressure and heart rate remained unchanged. In conclusion, DM2 plays an analgesic role in vivo and changes RVM cell activity, consistent with antinociception. These effects were even more potent than those elicited by ethosuximide treatments.