Neuroactive steroids and diabetic complications in the nervous system.

Important complications of diabetes mellitus in the nervous system are represented by diabetic peripheral neuropathy and diabetic encephalopathy. In this context, an important link is represented by neuroactive steroids (i.e., steroids coming from peripheral glands and affecting nervous functionality as well as directly synthesized in the nervous system). Indeed, diabetes does not only affect the reproductive axis and consequently the levels of sex steroid hormones, but also those of neuroactive steroids. Indeed, as will be here summarized, the levels of these neuromodulators present in the central and peripheral nervous system are affected by the pathology in a sex-dimorphic way. In addition, some of these neuroactive steroids, such as the metabolites of progesterone or testosterone, as well as pharmacological tools able to increase their levels have been demonstrated, in experimental models, to be promising protective agents against diabetic peripheral neuropathy and diabetic encephalopathy.

Testing Aß toxicity on primary CNS cultures using drug-screening microfluidic chips.

Open microscale cultures of primary central nervous system (CNS) cells have been implemented in microfluidic chips that can expose the cells to physiological fluidic shear stress conditions. Cells in the chips were exposed to differently aggregated forms of beta-amyloid (Aß), i.e. conditions mimicking an Alzheimer's Disease environment, and treated with CNS drugs in order to assess the contribution of glial cells during pharmacological treatments. FTY720, a drug approved for the treatment of Multiple Sclerosis, was found to play a marked neuroprotective role in neuronal cultures as well as in microglia-enriched neuronal cultures, preventing neurodegeneration after cell exposure to neurotoxic oligomers of Aß.

Treatment of advanced neuroblastoma: feasibility and therapeutic potential of a novel approach combining 131-I-MIBG and multiple drug chemotherapy.

Biological and clinical observations suggest that initial marked reduction of resistant clones may be critical in any attempt to improve long-term results in advanced neuroblastoma (NB). The aim of this pilot study is to determine short-term toxicity and efficacy of a new therapeutic model based on the simultaneous use of multiple drug chemotherapy and specific irradiation using 131-I-MIBG. The study population consisted of 21 patients, from 1 to 8 years of age with good 131-I-MIBG uptake. 16 extensively pre-treated patients with refractory or relapsed disease were divided into 2 groups. In Group 1 (9 patients) the basic chemotherapy regimen consisted in cisplatin at the dose of 20 mg/m(2) i.v. per day infused over 2 h, for 4 consecutive days; on day 4 Cy 2 g/m(2) i.v. was administered over 2 h followed by Mesna. Group 2 (7 patients) was treated with basic chemotherapeutic regimen plus VP16 and Vincristine. VP16 at the dose of 50 mg/m(2) i.v. per day was administered as a 24 h infusion on days 1-3; Vincristine 1.5 mg/m(2) i.v. was administered on days 1 and 6. On day 10 a single dose of 131-I-MIBG (200 mCi) with a high specific activity (>1.1 GBq/mg) was administered to both Groups by i.v. infusion over 4-6 hours. A further 5 patients were treated at diagnosis: 2 with the same regimen as Group 1 and 3 with the same as Group 2. The severity of toxicity was graded according to World Health Organization (WHO) criteria. Assessment of tumour response was monitored 4-6 weeks after the beginning of combined therapy (CO-TH). Response was defined according to INSS (International Neuroblastoma Staging System) criteria. No extra-medullary toxicity was observed in any patient. Haematological toxicity was the only toxicity observed and seemed mainly related to chemotherapy. Myelosuppression was mild in the 5 patients treated at diagnosis. No serious infections or significant bleeding problems were observed. In the 16 resistant patients, 12 PR, 1 mixed response and 3 SD were obtained. In the 5 patients treated at diagnosis 2 PR, 1 CR and 2 VGPR were observed. No alteration in 131-I-MIBG uptake was observed after the chemotherapy preceding radio-metabolic treatment. The therapeutic results of this pilot regimen of CO-TH resulted in a high percentage of major response after only a single course in both resistant patients and patients treated at diagnosis. Because of the minimal toxicity observed in patients studied at diagnosis so far, there is room for gradual intensification of the treatment. It is to be hoped that this suggested novel approach may represent an important route of investigation to improve final outcome in patients with advanced NB.

Antitumour activity of oxaliplatin in neuroblastoma cell lines.

Oxaliplatin appears non cross-resistant with cisplatin and has a comparable antitumour effect both in preclinical and clinical studies. We compared the antitumour effect of oxaliplatin with that of cisplatin in human neuroblastoma cell lines SK-N-DZ, LAN-1 and BE(2)M17 following 24 h exposure at concentrations ranging from 0.5 to 5 microM. Oxaliplatin was less potent with IC50 values 1.08-3.4-fold higher than cisplatin. Like cisplatin, oxaliplatin induced a cell cycle block in the G2/M phase although to a lesser extent than that caused by cisplatin. The concomitant increase of DNA fragmentation and decrease of G2/G1 ratio at 72 h indicated that a fraction of blocked cells underwent apoptosis. Morphological analysis confirmed these data, although oxaliplatin appeared to be 2-3 times less potent than cisplatin in inducing apoptosis. Our results indicate that oxaliplatin is active in neuroblastoma in vitro and this finding warrants in vivo preclinical studies.

Influence of cisplatin and doxorubicin on 125I-meta-iodobenzylguanidine uptake in human neuroblastoma cell lines.

The combination of 131I-meta-iodobenzylguanidine (MIBG) with chemotherapy has recently been employed in the treatment of advanced stage neuroblastoma with encouraging results. However, the mechanisms underlying the interaction between these two different modalities of treatment have not yet been explored. In this study, human neuroblastoma cell lines pretreatment with cisplatin and doxorubicin increased cellular 125I-MIBG accumulation in a dose-dependent manner. Cell cycle analysis showed that increased 125I-MIBG accumulation correlated with the drug-induced G2/M phase block. Northern blot analysis demonstrated an increase in gene expression of the noradrenaline transporter induced by doxorubicin, but not by cisplatin treatment. Increased 125I-MIBG accumulation was also observed in murine xenografts of the human neuroblastoma cell line SK-N-DZ or BE(2)M17 treated intraperitoneally (i.p.) with cisplatin or doxorubicin, respectively. These results suggest that the combination of 131I-MIBG and these drugs could selectively increase radiation doses delivered to neuroblastomas.

Progressive disease in children with medulloblastoma/PNET during preradiation chemotherapy.

The overall prognosis in children with medulloblastoma/PNET has not significantly improved over the past decade. Intensive neoadjuvant chemotherapy has not yet adequately explored. We evaluated the short-term clinical results of an intensive chemotherapy regimen in high risk children with newly diagnosed MB/PNET, after surgery and before radiation. Twelve previously untreated patients with high-risk medulloblastoma/PNET, according to Chang's classification, were treated with the following chemotherapy regimen: high dose carboplatin 600 mg/m2/day on days 1 and 2; the same course was administered 4 weeks later. One month later, high dose cyclophosphamide 2 g/m2/day on days 1 and 2, followed by an identical course 4 weeks later. Vincristine 1, 5 mg/m2 i.v. was given on the first day of each course. Systemic evaluation of the disease included imaging of the entire neuraxis, including MRI of the entire spine. Out of 12 enrolled, 7 patients were able to be evaluated for a residual disease after surgery. After two cycles of high dose carboplatin, we noted 1 CR, 4 PR and 2 MR. After the subsequent two cycles of high dose cyclophosphamide we observed an additional response in 4 cases. On the other hand, 4 patients clearly showed evidence of PD immediately after the first course of cyclophosphamide (2 cases) or following the second course. Three of the 4 patients had shown respectively 1 CR and 2 PR after the second course of carboplatin. Whereas it was confirmed that 2 courses of high dose carboplatin is effective in high risk MB/PNET children, we observed an unacceptable number of PD during the subsequent high dose cyclophosphamide therapy. A review from the literature also suggests that, in general, the longer radiotherapy is delayed, the higher the incidence of PD. In the search for the optimal drug combination in "sandwich chemotherapy" for children with high risk MB/PNET, PD must be reduced to an acceptable incidence, since a high number of PD may significantly lower the probability of long-term survival.

Veno-occlusive disease of the liver in right-sided Wilms' tumours.

Veno-occlusive disease of the liver (VOD) is an important complication in children with Wilms' tumour. Although in most patients this complication resolves uneventfully, fatal cases have been reported. Several observations strongly suggest that actinomycin-D is the likeliest cause of VOD in Wilms' tumour, but VOD seems to be rather uncommon in other malignancies treated with chemotherapy including actinomycin-D. The present case of VOD and the review of the literature stress the pathogenetic and clinical implications of VOD in the presence of a Wilms' tumour treated with actinomycin-D, originating in the right kidney. Greater awareness of this 'predisposing factor' may alert paediatricians to the presence of minimal signs of the syndrome.

Role of 131I-metaiodobenzylguanidine in the treatment of neuroblastoma.

BACKGROUND: Standard chemo-radiotherapy methods for the treatment of children with advanced neuroblastoma (NBL) including bone marrow transplant approaches have been disappointing. These poor results can be ascribed to the evolution of residual drug-resistant cell populations. Curative attempts should therefore be directed to their elimination during induction treatment. This can best be accomplished through the use of multiple, non-cross-resistant agents early in therapy. 131I-Metaiodobenzylguanidine (131I-MIBG) provides a mechanism for the delivery of high doses of radiation to NBL lesions. Experience reported from several institutions indicates an approximate 50% response rate in previously treated children with advanced NBL. CONCLUSIONS: A better strategy is to employ 131I-MIBG together with intensive chemotherapy at the time of diagnosis. A pilot study adopting these principles and supported by laboratory data has been designed and is underway.

Cytogenetic evidence for a less malignant leukemic cell population in the central nervous system in a critical case of acute myeloblastic leukemia.

BACKGROUND: With the exception of a single study the cytogenetic aspects of leukemic cells in the central nervous system (CNS) have not been investigated. PATIENTS AND RESULTS: During the course of a work-in-progress on the chromosomal constitution both of the spinal fluid and of bone marrow (BM) in children with acute myeloblastic leukemia (AML), we have observed a unique case of AML and CNS leukemia (CNSL) at diagnosis. The patient showed the simultaneous presence at diagnosis of a 46 cytogenetic line in the spinal fluid and a 47 (+8) cell line in the BM, present in the great majority of the metaphases examined. DISCUSSION: This observation allows hypotheses on the relationship between BM and CNS disease in AML. Regardless of the pathogenetic mechanism, the cytogenetic findings of the present case clearly suggest that the leukemic population in the CNS compartment represents a less malignant cell process compared to the BM leukemic population. This easily fits in with the usually less malignant course of CNSL in AML. CONCLUSION: The foregoing findings may have critical pathogenetic and therapeutic implications.

Optimal use of the 131-I-metaiodobenzylguanidine and cisplatin combination in advanced neuroblastoma.

Neuroblastoma (NB), a childhood radiosensitive tumor, is very aggressive and malignant, in its disseminated form, despite very intensive chemotherapy, prognosis continues to be dismal. Owing to its capacity to concentrate in NB lesions, large doses of 131-I-MIBG, have given very encouraging therapeutic results in patients resistant to conventional therapy as well as at diagnosis. We recently reported the first attempt in combination therapy (CO-TH) using 131-I-MIBG and cisplatin. This new form of CO-TH appears very effective in obtaining a rapid and excellent response in relapsed patients. In this report, we describe the results of further experience with CO-TH in disseminated NB. We have attempted to verify to what extent interaction between the effects of the two agents may produce therapeutic benefit, and we have sought the optimization of CO-TH use. Three stage IV NB patients were treated with CO-TH. The following treatment schedule, was planned: day 1, cisplatin 50 mg/m3 i.v. over 6 h; day 2, 131-I-MIBG 100-130 mCi at high specific activity (-1.1 Gbq/mg) i.v. over 6 h followed, a week later, by the same treatment combination. The therapeutic results were encouraging. However, hematological toxicity continued to represent a major limiting factor. In view of the overall effectiveness of CO-TH, at the price of lasting hematological toxicity, it may be indicated as a consolidation regimen some time before conditioning chemotherapy for autologous bone marrow transplantation.

The treatment of neuroblastoma with [131I]MIBG at diagnosis.

The potential role [131I]MIBG therapy in untreated, inoperable cases of neuroblastoma (NB) in children was evaluated. Six children, aged 10 months-5 years, were treated at diagnosis. Five (4 stage III and 1 stage IV NB) underwent [131I]MIBG treatment alone (single doses ranging from 2.9 to 6.1 GBq of high specific activity [131I]MIBG. In one case (stage IV NB) [131I]MIBG was preceded by Cisplatin administration (20 mg/m2/day) given over a 5 day period. The results obtained in the first 5 cases were as follows: 1 complete response still lasting after 5 years; 1 partial and 1 minor response allowing further surgery and chemotherapy; 2 stabilization of the disease. The treatment was well tolerated with minimal toxicity. However, apart from the first case all these children relapsed and subsequently died. Therefore [131I]MIBG therapy (9.1 GBq given in 2 courses) combined with Cisplatin as a "radiosensitizer" was used in the sixth case, a patient with widespread bone metastases and massive bone marrow involvement. A very good partial response was obtained in this case. Further surgery (of the primary NB) and multidrug chemotherapy was then possible. In conclusion, [131I]MIBG therapy at diagnosis appears to be effective, low toxic treatment of NB; when integrated with Cisplatin its efficacy seems to improve even more.

Constitutional trisomy 8 and myelodysplasia: report of a case and review of the literature.

A diagnosis of myelodysplastic syndrome was made in an 18-year-old patient with Warkany syndrome due to constitutional trisomy 8 mosaicism. The possible causal role of this particular chromosome constitution with respect to myelodysplasia and embryonal childhood tumors is discussed.

Carboplatin in childhood medulloblastoma/PNET: feasibility of an in vivo sensitivity test in an "up-front" study.

Sixteen patients with high risk MB/PNET at diagnosis were included in a pilot study employing carboplatin (CBDCA) as a single drug prior to conventional therapy. The main goal of the study was to identify in a short-term trial a significant response that would predict further response to CBDCA in the single patient. Exploration of CBDCA activity was focused on response after the first course as compared to the response following the second course. A course consisted of CBDCA 600 mg/m2 on days 1 and 2 administered in a 1 h infusion to be repeated 3-4 weeks later. After two cycles we observed 1 CR and 9 PR, that is a 62% response rate. The first course resulted in 5 PR, 5 MR, 5 SD, and 1 PD; after the subsequent course in all responding patients, response persisted or improved whereas in no patient with SD any improvement was observed. The correlation of response to the first course with response to the second course was statistically significant (P = 0.0009). The main toxicity of the single course was hematologic and consisted of rapidly reversible grade 3-4 neutropenia and thrombocytopenia in 94% of patients. Pharmacokinetic studies showed a very limited interpatient variability of both Cmax 57.6 +/- 9.9 micrograms/ml) and AUC (15.3 +/- 1.5 mg/ml.min) of free CBDCA, which eliminates an important variable in the evaluation of response. In conclusion, this "in vivo test" appears effective, reasonably safe, and reproducible in identifying patients likely to benefit from CBCDA: after a period of time as short as 3-4 weeks following the first course, multidrug chemotherapy including CBDCA may be employed in the responding patients, whereas an alternative regimen would be indicated in the non-responding patients.

A new approach in the treatment of stage IV neuroblastoma using a combination of [131I]meta-iodobenzylguanidine (MIBG) and cisplatin.

The outlook for disseminated neuroblastoma (NB) continues to be dismal. NB is a radiosensitive tumour. Owing to its high concentration in NB lesions, [131I]meta-iodobenzylguanidine [131I]MIBG has the potential for specifically delivering very large radiation doses to the malignant cells. Encouraging results have been reported with [131I]MIBG used alone in patients resistant to conventional therapy and at diagnosis. We report the first attempt to explore the integration of this new treatment modality with chemotherapy. Among the drugs effective in NB, cisplatin was chosen because of its high degree of activity against NB, its mild haematological toxicity and the known synergism between cisplatin and radiation. 4 patients, 3 with relapsed, heavily pre-treated, progressive stage IV NB, and 1 with stage IV NB at diagnosis, all with a good [131I]MIBG uptake, were investigated with combined therapy (CO-TH). Two complete remissions and one partial remission were observed in these patients 4-6 weeks following only a single course of both cisplatin and [131I]MIBG at "standard" dosage. The only toxicity was haematological, which was significant and relatively long-lasting, but was not associated with any serious infections or bleeding tendency. The general condition of these patients during the entire study period was excellent. The fourth patient, investigated at diagnosis with a modified less intensive treatment, obtained a partial remission with mild haematological toxicity. During the subsequent courses of intensive multidrug chemotherapy, this patient showed haematological toxicity comparable with that experienced by patients treated with an identical drug combination, but without previous treatment with CO-TH. The provisional conclusion of this ongoing study is that this new form of CO-TH appears most effective in obtaining a rapid and excellent response in heavily pretreated relapsed patients with progressive disease, and should be further investigated in earlier stages of the disease.