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BACKGROUND: Neuroblastoma (nbl) is one of the most common solid cancers in children. Prognosis in advanced nbl is still poor despite aggressive multimodality therapy. Furthermore, survivors experience severe long-term multi-organ sequelae. Hence, the identification of new therapeutic strategies is of utmost importance. Cannabinoids and their derivatives have been used for years in folk medicine and later in the field of palliative care. Recently, they were found to show pharmacologic activity in cancer, including cytostatic, apoptotic, and antiangiogenic effects. METHODS: We investigated, in vitro and in vivo, the anti-nbl effect of the most active compounds in Cannabis, Δ(9)-tetrahydrocannabinol (thc) and cannabidiol (cbd). We set out to experimentally determine the effects of those compounds on viability, invasiveness, cell cycle distribution, and programmed cell death in human nbl SK-N-SH cells. RESULTS: Both compounds have antitumourigenic activity in vitro and impeded the growth of tumour xenografts in vivo. Of the two cannabinoids tested, cbd was the more active. Treatment with cbd reduced the viability and invasiveness of treated tumour cells in vitro and induced apoptosis (as demonstrated by morphology changes, sub-G1 cell accumulation, and annexin V assay). Moreover, cbd elicited an increase in activated caspase 3 in treated cells and tumour xenografts. CONCLUSIONS: Our results demonstrate the antitumourigenic action of cbd on nbl cells. Because cbd is a nonpsychoactive cannabinoid that appears to be devoid of side effects, our results support its exploitation as an effective anticancer drug in the management of nbl.

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BACKGROUND: The coexistence of mycosis fungoides, a peripheral T-cell lymphoma, and B-cell malignancies or Hodgkin's lymphoma in the same patient is unusual. Most descriptions are isolated case reports and case series are strikingly sparse. OBJECTIVES: To detect cases of mycosis fungoides associated with B-cell malignancies or Hodgkin's lymphoma and to analyse the characteristics of and the interplay between the lymphoproliferative neoplasms. METHODS: Patients with mycosis fungoides who had B-cell malignancies or Hodgkin's lymphoma were selected from among 398 patients either treated or followed up in two tertiary medical centres during a 7-year period. RESULTS: Eleven patients with mycosis fungoides and B-cell malignancy were detected (seven of non-Hodgkin's lymphoma, three of chronic lymphocytic leukaemia, one of multiple myeloma). No case of Hodgkin's lymphoma was found. In seven patients the mycosis fungoides preceded the B-cell malignancy whereas in four it was the B-cell malignancy which occurred first. The time elapsed between onset of the two malignancies ranged from 4 to 22 years (average: 12 years). Patients who had mycosis fungoides as the first neoplasm presented with earlier stages of mycosis fungoides (four of seven: IA, three of seven: IB) than those who had mycosis fungoides as their second neoplasm (of four, one: IB, one: folliculotropic, two: IIB). Among the four patients in whom the appearance of mycosis fungoides followed the B-cell malignancy, three had been treated with multiagent chemotherapy. Two patients who presented with early-stage mycosis fungoides (IA) as the first lymphoma developed mycosis fungoides tumours after becoming immunosuppressed. In two patients infiltrates composed of both malignant T- and B-cell populations were found in a single biopsy. One showed two distinct populations of the malignant cells in the skin tumour, thus constituting a classical composite lymphoma of mycosis fungoides and chronic lymphocytic leukaemia, while in the other patient the two malignant populations of marginal B-cell lymphoma and mycosis fungoides (as evidenced by both phenotypic and genotypic findings) were intermingled. CONCLUSIONS: This case series indicates that while the coexistence of Hodgkin's lymphoma and mycosis fungoides is extremely rare, the association of mycosis fungoides and B-cell malignancies is not as rare as reflected in the literature, with non-Hodgkin's lymphoma constituting the most common associated B-cell malignancy. In this series as well as in the cases reported in the literature mycosis fungoides usually preceded the development of B-cell malignancies, which may be in accordance with previous reports of an increased risk of developing a second haematological neoplasm. The importance of a competent immune system for patients with mycosis fungoides is well demonstrated in these cases. It is suggested that for greater precision the criteria for diagnosis of composite lymphoma of the skin should include both phenotypic and genotypic features.

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Spontaneous fluctuations in activity of low-grade B cell lymphomas are common but not understood. An explanation may be offered by studying an atypical SLL/CLL case characterized by recurrent cycles of leukemic phase alternating with spontaneous remission (1). During remissions, residual IgMkappa+ leukemic cells exhibited resting phenotype, low proliferative response to CD4O-ligand and delayed apoptosis. In contrast, the acute phase counterparts were phenotypically activated, underwent rapid apoptosis in culture and proliferated extensively in response to membrane-anchored CD40-ligand. Transient bursts of serum TNFalpha and IL-10 preceded the acute phases, which were characterized by the co-existence of CD40-ligand+ T lymphocytes and lymphoma cells in the bone marrow. Based on ex-vivo and in-vitro data, we suggest that changes in the lymphoma milieu affect the neoplastic cell activation status, rate of proliferation in response to activated T cells and rate of apoptosis. These responses may underlie both the induction and spontaneous regression of the acute phases in this unique lymphoma. Our findings raise the possibility that part of this mechanism may have evolved during transformation of indolent common CLL to its more aggressive form.

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Several of the beta1 integrin receptors [very late antigen (VLA) molecules] for extracellular matrix (ECM) proteins are expressed by malignant T cells in cutaneous T-cell lymphoma (CTCL). We evaluated the function of VLA-1, a beta1 integrin specifically expressed in epidermotropic mycosis fungoides (MF), in CD4+ leukemic T cells Jurkat line). We found that Jurkat cells adhere significantly to collagens only after their activation with phorbol 12-myristate 13-acetate (PMA). However, the adhesion to collagen IV (but not to collagen I) of Jurkat cells selected for expressing increased levels of VLA-1 (with unchanged levels of VLA-2, the second collagen integrin receptor) was significantly enhanced relative to that of "VLA-1 low" cells. Monoclonal antibody (mAb) 1B3.1, directed against the collagen binding domain of VLA-1, inhibited adhesion to collagen IV and to collagen I by 36.67%+/-5.25% and 18%+/-4.32%, respectively (p<0.05), whereas the inhibition by anti-VLA-2 mAb PIE6 was comparable on both collagens (25%+/-7.48% and 36.3%+/-0.94%, respectively; p<0.09). Immuno-histochemical studies of skin biopsies from 10 untreated MF patients showed that in all cases at least 10% of the lymphocytes residing in the epidermis are VLA-1+VLA-2-. While not directly applicable to MF, the demonstrated functions of VLA-1 in leukemic Jurkat cells, together with its expression in MF skin, suggest a role for VLA-1 integrins in epidermotropism in a small proportion of leukemic MF cells.

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The ras proto-oncogene, a key component in the signal transduction cascade of activated growth factors, is involved in multiple tumor types, including basal cell carcinoma (BCC). rasGTPase activating protein (rasGAP), is a dual function protein in the ras signaling pathway, i.e., it downregulates activated ras via its catalytic domain, and it also participates in the downstream effector signaling pathway by mediating protein-protein interaction. Missense mutations presumably leading to rasGAP activation were previously detected in this gene, in a subset of BCCs. To assess the role of rasP21 and rasGAP in BCC tumorigenesis, we performed an immunohistochemical analysis of 48 BCCs, of which 45 were of the circumscribed variant (indolent-growth tumors) and the remaining 3 (2 morpheaform, 1 infiltrative), were aggressive-growth variants. rasGAP overexpression was demonstrated in 7 of 48 BCC cases, i.e., in 4 (8.8%) of 45 indolent-growth cases and in all of the 3 aggressive-growth cases. We detected tumor-specific reduction of rasP21 levels in 5 (11.1%) of 45 cases. There was no overlap between the tumors displaying rasGAP and rasP21 alternations and a high proliferation index, as assessed by Ki-67 staining, except for one case of aggressive-growth variant. We conclude that rasGAP overexpression is associated with BCC tumorigenesis in a ras-independent manner, is not reflective of the proliferation status of the tumor, and is more characteristic of aggressive-growth BCCs.

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Tumorigenesis has been shown to proceed through a series of genetic alterations involving protooncogenes and tumor suppressor genes. However, the investigation of genomic instability of microsatellites has disclosed a new mechanism for human carcinogenesis, which is involved not only in hereditary nonpolyposis colon cancer (HNPCC) but in a number of other malignancies as well. To determine whether microsatellite instability is involved in Hodgkin's disease, we screened 16 such tumors using 7 microsatellite marker loci on 6 chromosome arms 4, 5, 9p, 9q, 11, 14, and 17. Using the polymerase chain reaction method, DNA samples from the tumors and from normal peripheral blood leukocytes from each patient were compared for the allelic pattern produced at each locus. Five cases of genomic instability were identified, suggesting that this mechanism is relevant to the pathogenesis of HD.

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A 48-year-old man presented with recurrent syncope which was preceded by facial edema and difficulty in breathing. Physical examination, laboratory tests, abdominal CT and bone scan were all within normal limits. Bone marrow biopsy was consistent with mastocytosis. Systemic mastocytosis consists of a spectrum of disorders characterized by aberrant proliferation of tissue mast cells, and are mainly related to mast cell mediator release.

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We describe the occurrence of malignant lymphoma as a possible complication of immunosuppression associated with low dose methotrexate (MTX) therapy for juvenile rheumatoid arthritis (JRA). A 6-year-old girl with systemic onset JRA who had received low dose MTX therapy for 16 months developed diffuse peripheral lymphadenopathy and enlargement of the lymph nodes in the mediastinum, hilum of the lungs, and liver. Lymph node histology disclosed mixed cellularity Hodgkin's lymphoma; the neoplastic cells were positive for CD30 and CD15, but negative for Epstein-Barr virus RNA or EBV latent membrane protein. After chemotherapy, the girl had complete remission of her disease lasting for 18 months; however, the disease relapsed and autologous peripheral stem cell transplantation was performed. Although the occurrence of lymphoma may be associated with autoimmune diseases, our observations suggest that in pediatric patients, the increasing use of low dose MTX therapy for JRA may be an additional factor for the development of lymphoproliferative disease.

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We present a case of a 14-year-old girl with gastric large cell lymphoma. The girl's lymphoma was characterized by the presence of mucosa-associated lymphoid tissue. Infection with Helicobacter pylori (HP) was ascertained at the time of diagnosis. The girl was successfully treated by a combination of chemotherapy (MACOP-B) and anti-HP drugs (omeprazole plus amoxicillin). Thrombus of the inferior vena cava, a rare complication, evolved during treatment.

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Alterations in protein kinase C (PKC) activity have been implied in the pathogenesis of common variable immunodeficiency (CVID). We analyzed amiloride-sensitive red blood cell Na+/H+ exchange (sodium-proton antiport, SPA) and its response to protein kinase stimulation in a patient with CVID. Compared with healthy subjects or patients with sepsis, a unique pattern of SPA activation has been shown. The patient's SPA was decreased and unresponsive to PKC stimulation, whereas stimulation by insulin, a tyrosine kinase activator, restored SPA activity. An alteration of serine-threonine phosphorylation is suggested as a possible mechanism for the immune failure.

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The possibility that apoptosis and/or cell proliferation have a role in tumour progression in a murine T cell lymphoma was tested. The model consisted of the comparison of primary (PT) and metastatic tumour (MT) cells. The PT cells, but not the MT cells displayed a very pronounced tendency for spontaneous apoptosis. Proliferative capacity of MT cells was lower than that of PT cells, suggesting that it does not contribute to the metastatic phenotype in this system. Release from apoptosis does however, probably, play a role in the aggressiveness of the lymphoma.

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Recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) administered to bone marrow (BM) transplant recipients is associated with earlier recovery. We have investigated the possibility of stimulating normal donor mice in vivo with GM-CSF. Donor balb/c mice were injected i.p. with GM-CSF (5000 u) or saline. Seventy-two hours later 5 x 10(5)BM cells from either GM-CSF-treated or control donors were infused into lethally irradiated (850 R) recipients. In the recipients of BM from GM-CSF-treated donors, significantly higher CFU-S and significantly higher survival rate (57% [n = 65]; vs. 30% [n = 63]; p < 0.05) were noted. Donor mice of the GM-CSF group did not differ in bone-marrow cellularity and composition from their controls. However, recipients of BM from GM-CSF-treated mice had higher blood counts of haemoglobin, leukocytes and platelets compared to controls. These data demonstrate that pretreatment of BM donors with GM-CSF may be of benefit in improving survival and marrow engraftment in mice.

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Blood pressure control and its influence on the rat remnant kidney function were studied. The deterioration in kidney function was followed for up to 20 weeks at 4-weekly intervals in four groups of 5/6th nephrectomised rats. The groups studied were: (1) Control, untreated (C), given normal rat chow containing 21% protein; (2) nisoldipine (a dihydropyridine calcium channel blocker) treated (N), given nisoldipine freshly mixed daily in normal chow (0.3-0.6 mg/kg body weight); (3) dihydralazine-treated (H), fed normal chow and given dihydralazine added daily to the drinking water, about 15-25 mg/kg body weight daily; and (4) low-protein (6%) diet (LP), isocaloric and having the same sodium content as the normal chow. Proteinuria, serum creatinine, blood urea, histological damage as seen by light microscopy, and cumulative survival were taken to assess the severity of the chronic renal failure. All three therapeutic regimens attenuated significantly the rise in blood pressure which developed within less than 4 weeks in the rats with the remnant kidney. At the 16th week, means +/- standard deviations were, in group C, 237 +/- 20 mmHg; group N, 147 +/- 20 mmHg; group H, 164 +/- 23 mmHg; and group LP 149 +/- 16. Systolic blood pressure at the 8th week had a significant correlation with the serum creatinine of the 12th and of the 16th weeks. There was a strong correlation between blood pressure and the serum creatinine at the 16th week. This indicates that a time lag is necessary for the hypertension to have an effect on kidney function. Proteinuria, serum creatinine and blood urea were much higher in the untreated group.(ABSTRACT TRUNCATED AT 250 WORDS)

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A 67 year old woman developed a fatal febrile illness 8 years after mitral valve replacement for rheumatic valvular heart disease. The final disease persisted for 1 year and was characterized clinically by weakness, weight loss, congestive heart failure and multiple embolic events to the central nervous system and abdominal organs. The source of the emboli was a tumor, malignant fibrous histiocytoma of the left atrium, originating from the anulus fibrosus around the covered base of the prosthetic valve. This unique case suggests the possibility that chronic exposure to materials, such as Dacron, covering prosthetic valves may induce local malignant tumors.

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The possible alleviating effect of verapamil, a calcium entry blocker, on the resulting renal damage from the combination of a short episode of ischemia and CyA was studied in rats. Immediately after right nephrectomy the rats were divided into five experimental groups. Group 1: left renal pedicle clamping for 20 minutes. Group 2: as group 1 plus CyA 60 mg/kg bw i.p. Group 3: CyA as in group 2 but sham operated. Group 4: as group 2 plus verapamil 10 mg% in the drinking water. Group 5: as group 3 plus verapamil given as in group 4. The experiments lasted 4 days. By analysis of variance: CyA + ischemia (group 2) showed lower creatinine clearance (p less than 0.001), higher blood urea (p less than 0.01), fractional excretion of sodium (p less than 0.05) and fractional excretion of potassium (p less than 0.01) and fractional excretion of negative free water clearance (p less than 0.001) compared to ischemia alone (group 1). The CyA + ischemia rats treated with verapamil had higher creatinine clearance (p less than 0.05), lower blood urea (p less than 0.01), fractional excretion of sodium (p less than 0.001), fractional excretion of potassium (p less than 0.001) and fractional excretion of negative free water clearance (p less than 0.05) compared with the untreated verapamil CyA + ischemia group. The CyA + sham operated verapamil treated group had similar creatinine clearance with the corresponding verapamil untreated group. The CyA + ischemia group had the higher mean daily body weight reduction compared with all other groups. Histology showed more vacuolization of tubular epithelial cells in the CyA + ischemia than in ischemia alone.(ABSTRACT TRUNCATED AT 250 WORDS)

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