Combined differentiating therapy for myelodysplastic syndromes: a phase II study.

An in vitro synergism between different inducers of AML cell differentiation has been previously observed. Therefore, we treated 53 myelodysplastic (MDS) patients with a low dose combination of cis-retinoic acid (cRA, 20-40 mg/day) and 1,25 alpha (OH)2 cholecalciferol [(OH)2D3, 1-1.5 micrograms/day] +/- intermittent 6-thioguanine (30 mg/m2/day). The latter was reserved for patients with bone marrow (BM) blast excess (> or = 5%). The treatment was well tolerated, without major toxicity. Among 25 patients with BM blasts less than 5%, we observed one complete, eight partial and four minor responses (response rate 52%) with a median response duration of 8 months (2 +/- 24). Median survival, which did not correlate with response, is projected at 76 months. Thirty-one patients with BM blast excess (> or = 5%), including three of the previous group who progressed to refractory anemia with excess of blasts (RAEB), were treated with the three-drug protocol. One complete, 12 partial and six minor responses were obtained (response rate 61%) with a median response duration of 6 months (2-29+). A significant difference in survival (P < 0.005) was observed between the 19 responders (median 25 months) and the 12 non-responders (median 9 months). A reduction in the transfusion need was observed in 41% of the transfusion-dependent patients with blast excess and in 53% of those without blast excess. Therefore, combined differentiating therapy seems more effective than previously reported single agent treatments and should be considered for a larger randomized study to assess its actual impact on survival of MDS patients.

Efficacy and safety of short intravenous amiodarone in supraventricular tachyarrhythmias.

The safety and efficacy of short intravenous therapy with amiodarone were evaluated in 44 patients (24 males, 20 females), aged 21-84 years, with supraventricular tachyarrhythmias newly arisen in less than 24 hours. The study group consisted of 15 patients with paroxysmal supraventricular tachycardia, 8 patients with atrial flutter and 21 patients with atrial fibrillation. They were treated with a single infusion of amiodarone up to 2 hours after the restoration of a stable sinus rhythm, or up to a maximum dose of 2400 mg in 24 hours. Our study shows that 88.6% of all supraventricular tachyarrhythmias reverts to sinus rhythm in less than 24 hours: 100% of paroxysmal supraventricular tachycardia, 75% of atrial flutter, and 85.7% of atrial fibrillation. Intravenously administered amiodarone proves to take effect rapidly (0.5 to 22 hours). The plasma amiodarone concentrations at sinus rhythm restoration showed a wide range (405-3800 ng/ml). Piecewise analysis suggested that the probability of sinus rhythm was 14.4-fold greater in paroxysmal supraventricular tachycardia. No linear statistical relationship was detectable between the log-dose-body mass index and log-QTc. Total amiodarone dose and left atrial volume are inversely correlated with a statistically significant difference. The toxicity in our short intravenous course with amiodarone was not relevant. We conclude that short high-dose intravenous amiodarone shows efficacy and safety in all newly occurring supraventricular tachyarrhythmias.

[The acute treatment of supraventricular tachycardia with endovenous amiodarone]. / Trattamento acuto delle tachicardie sopraventricolari con amiodarone endovena.

In the present study we evaluated 35 patients of both sexes, aged 21-84, with newly occurring supraventricular tachyarrhythmias, 19 atrial fibrillation (AF), 6 atrial flutter (FL) and 10 paroxysmal supraventricular tachycardias (PSVT). They were treated with a single amiodarone infusion up to two hours after the restoration of a stable sinus rhythm or to a maximus dose of 2,400 mg (in 24 hours). Plasma amiodarone concentration and QTc were measured at the restoration of sinus rhythm and twelve hours after the amiodarone withdrawal. Amiodarone infusion restored a stable sinus rhythm in all 10 patients of the PSVT group (100%), in 5 of the FL group (83%) and in 16 of the AF group (84%). The average dose needed to stop PSVT was lesser than for AF and FL (M + SE: 473.3 +/- 36.88 vs 1842.1 + 259.6 vs 1548.8 +/- 345.5 mg; p less than 0.001). The average plasma amiodarone concentration at the restoration of sinus rhythm was 2450.4 +/- 175.9 SE ng/ml in all the tachyarrhythmias as a whole without any statistically significant difference among PSVT, FL and AF. Moreover no correlation exists between plasma amiodarone concentrations and the amount of amiodarone infused. QTc showed a statistically significant transient lengthening at the restoration of sinus rhythm, but not twelve hours after amiodarone withdrawal. In conclusion, a single dose of amiodarone is effective and safe in all newly occurring supraventricular tachyarrhythmias, without any important side effect and with a high therapeutic index in pharmacologic cardioversion as alternative treatment to cardioversion.

[Effect of somatostatin and salmon calcitonin on carcinoid syndrome. A clinical case]. / Effetto della somatostatina e della calcitonina di salmone nella sindrome da carcinoide. Caso clinico.

In carcinoid syndrome, calcitonin administration proved to have an effective action in reducing symptomatology. During the perioperative period, treatment with somatostatin, thanks to the ease of administration of the drug and the reductive action of gastroenteric secretion, demonstrated its usefulness in countering the action of serotonin. In the present case, the data reported in the most recent literature on the use of the two drugs in the carcinoid syndrome are confirmed.

[ Action of low doses of vincristine, lidocaine and verapamil on DNA replication in vitro]. / Azione "in vitro" di basse dosi di Vincristina, di Lidocaina e di Verapamil sulla duplicazione del DNA.

Lidocaine and Verapamil at pharmacological doses which for single drug are not cytotoxic, when used together in vitro, inhibit DNA replication in PHA-stimulated lymphocytes but not in Jurkat cell (T-ALL line) cultures. At the same concentration the two drugs used in association with very low doses of Vincristine are cytotoxic to PHA-stimulated lymphocytes and Jurkat cells. Cytotoxic action of Doxorubicin is not increased by Lidocaine or by Verapamil or by an association of the two drugs. Changes in calcium ion concentration in the medium did not show any significant effect. These results suggest that Lidocaine and Verapamil have a common mechanism of action and have a toxic action on the same cell structure of Vincristine; furthermore the cytotoxic action of Vincristine is considerably increased. These in vitro effects could be tested in animal models.

[Verapamil inhibits the in vitro synthesis of DNA. I. Study of human lymphocyte cultures]. / Il Verapamil inibisce la sintesi del DNA "in vitro". I. Studio su colture di linfociti umani.

Verapamil in vitro reduced 3H-TdR incorporation into lymphocytes. High doses of Verapamil were lethal for cells; low doses inhibit DNA synthesis, but cell viability by the Trypan blue exclusion method is preserved. Increasing the concentration of Ca++ in the medium partially improved lymphocyte viability and 3H-TdR incorporation. Modification of the Na+ and K+ content in the medium did not interfere with Verapamil action. The inhibitory action was not completely reversible even when the cells were exposed to the drug for a short time (15'). Our results confirm the dependency of lymphocyte blast transformation on Ca++ during the first 20 h. Nifedipine did not inhibit cell replication, which suggests a different mechanism of action. Our investigation suggests that there is more than one model for calcium-antagonism and that the action of Verapamil can not be explained only by its influence on transmembrane Ca++ flux. We believe that Verapamil has a negative action on cell metabolism directly through an interaction on transmembrane Ca++ flux and on intracellular Ca++.

[Verapamil inhibits DNA synthesis in vitro. II. Study of the MCF7 and Jurkat neoplastic cell lines]. / II verapamil inibisce la sintesi del DNA "in vitro". II. Studio delle linee neoplastiche MCF7 e Jurkat.

Verapamil in cultures of mammary carcinoma MCF7 cells and Jurkat A.L.L. cells decreased the 3H-TdR incorporation. The action of Verapamil is dose-dependent. The inhibition percentage of 3H-TdR incorporation into Jurkat cells by Verapamil was lower than into MCF7 cells. No change of the mitotic inhibition was observed with higher Ca++ concentration in the medium. Modification of the Na++ and K++ content in the medium did not change action of Verapamil; this is in agreement with the independence of neoplastic cells from the culture medium. Our investigation suggests that Verapamil does not work through a block of transmembrane Ca++ flux, but rather through an intracellular interaction.

[In vitro inhibition of DNA replication by local anesthetics. Effects on human MCF7 neoplastic cells]. / Inibizione "in vitro" della duplicazione del DNA da parte di anestetici locali. Effetti su cellule neoplastiche umane MCF7.

The action of two local anesthetics (Lidocaine and Bupivacaine) on cells of mammary carcinoma MCF7 was investigated. 3H-TdR incorporation decreases in relation to the dose, and viability by Trypan blue does not significantly change but at high doses of anesthetic. Intercell adhesion decreases only at high concentration. When Lidocaine is removed after the fourth hour and Bupivacaine after the second hour the antimitotic action is irreversible. The inhibiting action of drugs is related to the cell number and unrelated to the time of adding the drug. There was no change of Lidocaine and Bupivacaine action on neoplastic cells at different concentration of Na+, K+ and Ca++ in the medium. Neoplastic cells are partially independent from Ca++ and we think the antimitotic effect of local anesthetics we observed can be due to: antagonist action to calmodulin; inhibition of aminoacylation of tRNA; inhibition of cholesterol synthesis; modification of membrane permeability which is however significant only for high concentration of the drug.

[Parameters of cellular immunity in subjects with bronchial squamous cell tumors]. / Alcuni parametri dell'immunità cellulare in soggetti con neoplasia bronchiale a cellule squamouse.

We studied some cell mediated immunologic assay in a normal population and in patients with squamous cell carcinoma of the bronchus. In cancer patients lymphocyte mitogen stimulation with PHA and PWM did not show any significant difference from normal population; PPD antigenic stimulation was lower in eight patients of ten. E-total rosette forming cells count was reduced, there was no difference in E-active rosette forming cells. Electrophoretic mobility of lymphocytes showed that a part of lymphocytes have a lower electrophoretic cell migration. Lymphocytes subpopulations isolated by E rosetting technique are different in cancer patients from subpopulations separated by electrophoresis; in controls similar subpopulations were obtained by the two methods. In cancer patients cell mediated immunity shows altered functions which is though not uniformly modified. We think that serum factors and cells with blocking action cause these effects rather than intrinsic changes of lymphocytes.

[In vitro lymphocyte immunoreactivity in sarcoidosis patients. Stimulation with Kveim antigens]. / Immunoreattività linfocitaria "in vitro" in pazienti affetti da sarcoidosi. Stimolazione con antigene di Kveim.

12 patients suffering from sarcoidosis have been studied in addition to clinical and bioptic investigations, they were submitted to intradermal reaction with PPD, Candida Albicans and Kveim's antigen. Lymphocytes from the 12 patients were placed in culture and stimulated with phytohaemagglutinin (PHA), pokeweed mitogen (PWM), concanavalin A (CON-A), PPD, Candidin and Kveim's antigen. Six patients proved positive to Kveim's antigen in vivo, and four of them (66%) in vitro also. No patient was immunodepressed. Of the 6 patients negative to Kveim's antigen both in vivo and in vitro, 4 were clearly immunodepressed, as shown by the reduced mitogen response, the negative response to antigen stimulation, and to the intradermal reaction. The results are discussed in the light of recent findings regarding the role of the immunocompetent system in sarcoidosis.

[Lymphocyte immunoreactivity in subjects vaccinated with Calmette-Guerin bacillus (BCG)]. / Immunoreattività linfocitaria in soggetti vaccinati con bacillo di Calmette e Guerin (BCG).

PHA, Pokeweed and PPD lymphocytes transformation in vitro was studied in four groups of people. One group was negative to PPD skin testing; one was positive for a "naturally" acquired infection; the third group were people vaccinated with BCG in the last year; fourth group people vaccinated with BCG within one and five years. Last two groups had generally low or negative reaction to PPD skin test. PPD was used at different concentration, from 0.025 to 35 microgram/ml; maximum stimulation was at 1 microgram/ml. Stimulation index was lower in vaccinated people than in "natural" positive. Lymphocytes of people vaccinated from more than one year showed no difference from PPD negative people. Highly significant difference was observed between these two groups and people "naturally" positive and within one year of vaccination. We discuss our data and interpret the findings as showing that there are less PPD sensitive lymphocytes in patients vaccinated with BCG than in people with a "natural" infection and that this circulating population of lymphocytes disappears or decreases in the years following vaccination.

[The action of insulin on human lymphocytes stimulated with mitogens "in vitro". I. Study on normal subjects]. / L'azione dell'insulina sui linfociti umani stimolati con mitogeni "in vitro". I--Studio su soggetti normali.

Insulin at 25, 50, 250, 500 and 1000 mcU/ml concentration added to lymphocyte cultures under PHA stimulation increases [3H] Thymidine incorporation. Maximum effect is obtained at 50 mcg/ml of PHA and 250 mcU/ml of insulin after 96 hours of incubation. Insulin stimulates cultures when it is added between the 12th and the 24th hour. Cultures stimulated wih high dose (250 mcg/ml) of PHA do not show any increase in mitosis. Ours and other Authors results seem to show that the mechanism of action of insulin works through specific receptors on lymphocytes. These receptors appear some hours after mitogen stimulation; our results showing maximum effect when insulin is added after 12-24 hours support this hypothesis.