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Biomedical subjects

M Boiocchi

Publications and source records attributed to M Boiocchi.

206 records · Page 12Linked to original sources
PubMedDate not supplied

Effect of hyperthermia on intracellular drug accumulation and chemosensitivity in drug-sensitive and drug-resistant P388 leukaemia cell lines.

Enhancements of the drug-induced cytotoxicity and modifications of drug transmembrane equilibria caused by hyperthermic treatment were analysed on P388/S and P388/R murine leukaemia cell lines. The P388/R cell line was derived from the P388/S cell line by drug selection of mutant, drug-resistant clones; it expresses a pleiotropic drug resistance towards some chemotherapeutic drugs such as doxorubicin, daunorubicin and etoposide, but is only weakly resistant towards other drugs as cis-diammine-dichloroplatinum. Hyperthermic treatment enhanced the drug cytotoxic effects much more on the P388/R cell line than on the P388/S line, but the cytotoxic enhancements were consistent only for the drug towards which the P388/R cell line expresses pleiotropic resistance. Intracellular drug accumulation analysis and drug transmembrane equilibria determinations indicated that the resistance of both cell lines to the intracellular drug was not affected by hyperthermic treatment, whereas variations in drug influx, but not in drug extrusion, were induced by heat treatment. The study suggested, therefore, that hyperthermia does not modify intracellular chemosensitivity of either cell line, but acts on membrane permeability by facilitating attainment of the intracellular drug concentrations needed to cause the cytotoxic effect.

Animals↗
PubMedDate not supplied

Microsatellite instability and MLH1 and MSH2 germline defects are related to clinicopathological features in sporadic colorectal cancer.

Clinical and pathological features were evaluated to predict tumor microsatellite instability (MSI) and germline mutations in MLH1 and MSH2 DNA mismatch repair genes in two patient groups with sporadic colorectal cancer (CRC): 38 young patients (age </=45 years) and 31 old patients (age >/=60 years). Nine (25.7%) young patients out of 35 and five (16%) old patients out of 31 exhibited MSI in their cancers. MSI+ cancers were related to proximal cancer and mucinous carcinoma independently of the age at cancer onset. Three (7.9%) out of 38 young patients had mutations in MLH1 and MSH2 genes that led to truncated protein products; they were all at age <35 years and showed MSI in their tumors, with mucinous histotype in two cases. In conclusion, histopathological and clinical features of CRC allow identification of cancers showing DNA microsatellite instability. MSI in CRC at very early onset (age <35 years) appears useful to predict germline MMR gene defects.

Adaptor Proteins, Signal Transducing↗
PubMedDate not supplied

Lack of Fas and Fas-L mutations in patients with lymphoproliferative disorders associated with Sjögren's syndrome and type II mixed cryoglobulinemia.

OBJECTIVE: Murine models (MRL/gld/gld mice) and recent evidence in humans suggest a possible role of Fas and Fas ligand (Fas-L) germline mutations in the pathogenesis of autoimmune-related lymphoproliferation, including adult cases. In this study, the presence of Fas and Fas-L germline mutations was investigated in a consecutive series of adult patients with lymphoproliferative disorders occurring in the context of Sjögren's syndrome (SS) and type II mixed cryoglobulinemia (MC). METHODS: 11 patients (8 primary SS and 3 type II MC; F/M: 10/1; mean age 64 yrs.) were investigated. All patients were suffering from atypical lymphoproliferative disorders or MALT lymphoproliferative lesions (mean duration 3.5 yrs.). Four patients later developed a malignant lymphoma. DNA from peripheral blood mononuclear cells from 11 patients and 10 controls was tested for germline mutations in the Fas gene (exons 4, 8 and 9) and Fas-L gene (exon 4) by the polymerase chain reaction-single strand conformation polymorphism (SSCP) method. RESULTS: All DNA samples from both patients and controls showed amplification of Fas and Fas-L specific fragments. Identical SSCP migration patterns were observed in all the cases, indicating the lack of mutations in the whole series. CONCLUSION: Although it cannot be excluded that Fas and Fas-L mutations might be present in exons different from those analyzed, our data do not support the hypothesis that germline mutations in these genes are responsible for a major subset of lymphoproliferative syndromes in adult patients with SS and type II MC. Additional studies would be worthwhile in SLE-related lymphoproliferation, which is, however, a subset of limited clinical relevance when considering all cases with autoimmune-related lymphoproliferation.

Aged↗
PubMedDate not supplied

[Cerebrospinal rhinorrhea from an ethmoido-sphenoidal mucocele. Description of a rare clinical case].

The authors give a brief introduction on the subject of mucocele and emphasize the rarity of the ethmoid-sphenoid location (55 cases listed by Lundgren in 1961). The principal clinical features are discussed which are: ocular and periocular and sometimes, occipital pain; ocular symptoms, often bilateral, of compression of the optic nerve and of the 3rd and 4th cranial nerves; and only rarely, slight signs of nasal obstruction or of hypopituitarism. Of the various surgical approaches, the lower trans nasal septum operation seems to be the best choice. A case report of a patient with copious spontaneous rhinorrhea followed by meningitis is reported. The authors note that this symptom, not previously encountered in the literature, permitted a diagnosis to be made before the lesion became bilateral, which prior to this case, had always been observed. The lower trans-septum surgical approach with the aid of a microscope was employed, permitting total removal of the mucocele and tamponage of the cerebrospinal fluid fistula.

Cerebrospinal Fluid Rhinorrhea↗
PubMedDate not supplied

Cellular and molecular bases of B-cell clonal expansions.

The concept that lymphomagenesis is a multistep process is now widely accepted. Various factors are involved in the development and malignant progression of B-cell lymphoproliferative disorders. The most frequently recognized alterations in these disorders are chromosomal translocations which lead to the activation of proto-oncogenes (c-myc) or genes encoding for proteins involved in the control of the cell cycle (cyclin D1), differentiation (bcl-6) and apoptosis (bcl-2). In addition, genetic changes that inactivate tumor suppressor genes (p53, Rb, p16) have recently been identified. Infectious agents may also play a role in lymphomagenesis either by directly driving B-cell proliferation (EBV) or by inducing a chronic antigenic stimulation (EBV, HCV, HBV, helicobacter pylori). Finally, several data indicate that local cytokine networks and, in particular, autocrine (IL-6, IL-10) and/or paracrine (IL-2, IL-4, IL-6) loops probably play a contributory role in the development and evolution of B-cell lymphoproliferation. In the last few years, the advent of molecular biology techniques has allowed important advances in the definition of the events involved i the earlier phases of lymphoma development. This has been made possible, in particular, by the study of a series of oligoclonal or monoclonal lymphoproliferative disorders characterized by an indolent or "smoldering" clinical course, such as follicular lymphoma and the lymphoproliferation associated with autoimmune diseases, which are at high risk of evolution to a highly malignant lymphoma. In nearly all of these conditions, the clonal B-cells responsible for the early stages of the disease are probably not fully transformed and retain various degrees of responsiveness to a wide variety of microenvironmental stimuli (antigen or autoantigen stimulation, interactions with "reactive" T lymphocytes, local cytokine networks). These latter in turn may induce the regression of pathological lesions, maintain the disease in an active state or contribute to the evolution towards an overtly malignant lymphoma. These findings open new avenues for the design of unconventional strategies of intervention aimed at preventing the malignant evolution of pre-lymphomatous lesions and controlling the clinical course of certain low-grade B-cell lymphomas.

Animals↗
PubMedDate not supplied

The role of molecular analyses of B-cell and T-cell clonality in the study of B-cell lymphomagenesis.

While the simple detection of B-cell clonality does not imply B-cell malignancy, comprehensive analyses of B-cell clonality are crucial to investigate the pathobiology of B-cell lymphoproliferative disorders. Our recent studies in patients with Sjögren's syndrome have highlighted how multiple molecular analyses of B-cell clonality (Southern blot, polymerase chain reaction, single strand conformation polymorphism, and DNA sequence analysis) in prelymphomatous lesions may be of great value in helping to define the stages of progression towards low-grade malignancy. The study of T-cell expansion may also be important in investigations of the pathobiology of the different stages of B-cell lymphoproliferation (fully benign, pseudolymphomatous, or definitely malignant), which may still be T-cell-and antigen/ autoantigen-dependent.

B-Lymphocytes↗
PubMedDate not supplied

Pharmacology of chronic oral daily administration of idarubicin.

Idarubicin (4-demethoxydaunorubicin) (IDA) is a daunorubicin analogue with substantial activity in hematologic malignancies and solid tumors. Among several reasons, IDA is of interest because of its main metabolite derivative, the C-13 alcohol analogue, idarubicinol (IDOL). Previous studies have suggested that IDOL, unlike other anthracycline metabolic derivatives, possesses a striking growth-inhibitory activity in tumor cell lines. This suggests that IDOL, like IDA could be useful in circumventing MDR. IDA is bioavailable in an oral dosage form. After oral administration of IDA to the patients, the concentration of IDOL quickly exceeds that of IDA and is retained in the plasma for a longer period. Hence, administration of IDA to cancer patients results ina much greater overall exposure of the tumor to IDOL than to the parent compound. At the Oncology Center (CRO) in Aviano we performed a dose-finding and pharmacokinetic (PK) study of chronic daily oral IDA with intrapatient escalation in patients with metastatic breast cancer (MBC). All the patients were pretreated with anthracyclines (the cumulative dose was 530 mg and 264 mg, respectively, for epirubicin and (DOX) and had at admittance a PS < or = 2 and a left ventricular ejection fraction > 50%. IDA (1 mg capsules) was administered orally twice a day for 21 days every two weeks. Treatment was continued at escalating doses until progression or intolerance. Twenty-five patients were enrolled. MTD has not yet been reached and clinical results are reported in Table 1. Treatment was well-tolerated in all but one patient (300 ANC at day 28). Three patients had tox G3 ANC for more than three weeks after 3, 6, and 7 mg doses, respectively. Two of them stopped chemotherapy after 1 cycle and 1 patient stopped after 2 cycles (6 mg doses). Despite previous treatments with anthracyclines (the mean cumulative dose before entering the study was 530 and 264 mg, respectively, for epirubicin and DOX) no cardiotoxicity due to IDA treatment was observed. This trial demonstrates the feasibility of chronic daily IDA administration. At the dosage reported, treatment was generally well tolerated. The PK findings (high IDOL concentrations) and the unexpected G4 myelotoxicity in patients with the highest IDOL plasma concentrations suggest that IDOL is clinically relevant.

Administration, Oral↗