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Biomedical subjects

G Palmieri

Publications and source records attributed to G Palmieri.

At least 127 records · Page 7Linked to original sources
PubMed1994

A new enzyme immobilization procedure using copper alginate gel: application to a fungal phenol oxidase.

A new procedure was developed for enzyme immobilization by entrapment in copper alginate gel. The mechanical properties of the copper alginate gel were characterized and compared with those of the most widely used calcium alginate. The system was applied to the immobilization of a fungal phenol oxidase. Optimal conditions for enzyme immobilization were set up: the system immobilized 85% of the enzyme, and the remaining 15% was recovered in the aqueous immobilization medium. The stability and activity of the immobilized enzyme were studied. After immobilization, the enzyme was active in a wider pH range, the temperature of its optimal activity was shifted to lower values, and the possibility of storage at 4 degrees C was greatly improved. The immobilized enzyme generally increased the rate of oxidation of various substrates. The results indicate a potential use of this system for the construction of bioreactors to be used in the detoxification of polluted waste waters.

Agaricales↗
PubMed1994

Combination of vinorelbine, cisplatin, and etoposide in advanced non-small cell lung carcinoma: a pilot study.

The combination of vinorelbine (VNR), cisplatin (CDDP) and etoposide (VP16) was reported to obtain major responses in more than 40% of patients with advanced non-small cell lung carcinoma (NSCLC). However, optimal dosages and schedule of the three drugs has remained unsettled. This trial was carried out to further assess the activity and toxicity of this regimen. We treated 19 patients (all males) affected by NSCLC, with a median age of 62 years and a median ECOG performance status of 1. Eleven of them had locally advanced disease and 8 showed distant metastases. The dose of CDDP was 30 mg/m2 i.v., while VP16 was given at 80 mg/m2 i.v. Both drugs were administered for 3 consecutive days every 3 weeks. The first 7 patients also received VNR 25 mg/m2 i.v. on days 1 and 8, while in the subsequent 12 cases VNR was administered at 30 mg/m2 i.v. on day 1. An overall activity of 42% (95% confidence limits, 20%-66%) was observed among treated patients, with no significant differences related to stage or histology. The dose limiting toxicity was essentially a grade 3-4 neutropenia occurring during treatment in 50% of patients, regardless of schedule employed. The actual median dose intensity of VNR was 13 mg/m2/wk (78% of the planned one) in the first 7 patients, and 9 mg/m2/wk (90% of the ideal one) in the following 12 patients. Though eight patients are still alive from 18+ to 29+ weeks at the time of this analysis, the overall median survival time was only 25 weeks. Our results support the high activity of this three-drug regimen in advanced NSCLC. However, the actual impact of this treatment on survival of patients should be defined with randomized trials.

Aged↗
PubMed1994

Cytosine arabinoside (Ara-C) plus alpha-interferon (alpha IFN) determine prolonged complete remissions in patients with aggressive non-Hodgkin's lymphoma partially responsive to first-line doxorubicin-containing regimens.

Ten patients with aggressive NHL who failed to achieve a complete remission with first-line chemotherapy were treated with Ara-C and alpha IFN. Ara-C was administered subcutaneously at 100 mg on day 1, 150 mg on day 2 and 200 mg on days 3, 4 and 5 of a 28 d cycle; alpha IFN was given at 3 million International Units three times a week and continued for 2 years in CR patients. Six CR were attained with a median duration of 36+ months. Toxicity was mild. A new approach to second-line therapy for aggressive NHL is proposed.

Aged↗
PubMed1993

Inhibition of tumor growth and enhancement of metastasis after transfection of the gamma-interferon gene.

Cells from the spontaneous metastatic TS/A mammary adenocarcinoma of a BALB/c mouse were transfected with the murine gamma-interferon (IFN-gamma) gene. Six clones (IFN-gamma clones) releasing between 2 and 6,000 international units (IU) of IFN-gamma/ml culture medium, were compared to TS/A parental cells (TS/A-pc) and to cells transfected with neomycin resistance gene only (NEO cells). Autocrine IFN-gamma up-regulated membrane expression of H-2 class-I and Ly-6 glycoproteins, but did not alter cellular proliferation in vitro. All IFN-gamma clones gave rise to progressive tumors with a growth rate significantly slower than that of tumors induced by TS/A-pc and NEO cells, and inversely correlated with the amount of IFN-gamma secreted. TS/A-pc and NEO tumors displayed a marginal reactive infiltrate, whereas those formed by IFN-gamma clones were massively infiltrated mostly by macrophages. In T- and NK-deficient mice the growth of tumors formed by IFN-gamma clones was not enhanced. In vitro tests showed that IFN-gamma clone cells were markedly more lysed by macrophages than TS/A-pc and NEO cells, while they remained poorly sensitive to NK and LAK cells. These data as a whole suggest that the development of solid tumors by IFN-gamma clones is primarily hampered by macrophages and not by T-lymphocytes or NK cells. When spontaneous metastatic ability was compared, 2 IFN-gamma clones releasing 2-4 IFN-gamma IU/ml were significantly more metastatic, while most IFN-gamma clones appeared to be as metastatic as NEO cells. By contrast, following intravenous challenge, all IFN-gamma clones produced 5-10 times more experimental metastases than NEO cells. The higher metastatic ability of IFN-gamma clones was attributed to increased resistance to NK cells since, in NK-depleted BALB/c mice, metastatic spread of IFN-gamma clones was not enhanced, whereas a 50-fold increase in the number of metastases was found upon injection of NEO cells.

Adenocarcinoma↗
PubMed1993

1.5-Mb YAC contig in Xq28 formatted with sequence-tagged sites and including a region unstable in the clones.

A contig of 20 yeast artificial clones (YACs) has been assembled across 1.5 Mb of Xq28 and formatted with nine previously reported probes and nine STSs developed from the sequence of probes and end fragments of YACs. YAC end fragments were obtained by subcloning, Alu-vector PCR, or primer-ligation PCR methods. Eighteen of the YACs were recovered from a library specific for Xq24-q28; two that fill a gap were obtained from a second library made from total human DNA. One region, containing probes pX78c and 2A1.1, was unstable in YACs, but it was possible to generate a self-consistent map of DNA over the entire contig. Overlaps were confirmed by Southern blot analyses of YAC DNAs, and pulsed-field gel electrophoresis confirmed the extent of the contig and identified at least four CpG islands in the region.

Base Sequence↗
PubMed1993

Actin-binding protein (ABP-280) filamin gene (FLN) maps telomeric to the color vision locus (R/GCP) and centromeric to G6PD in Xq28.

Actin-binding protein-280 (ABP-280) is a dimeric actin filament crosslinking protein that promotes orthogonal branching of actin filaments and links actin filaments to membrane glycoproteins. We have mapped the ABP-280 filamin gene (FLN) to Xq28 by Southern blot analysis of somatic cell hybrid lines, by fluorescence in situ hybridization, and through identification of portions of the FLN gene within cosmids and YACs mapped to Xq28. The FLN gene is found within a 200-kb region centromeric to the G6PD locus and telomeric to DSX52 and the color vision locus.

Blotting, Southern↗
PubMed1993

Stability and activity of a phenol oxidase from the ligninolytic fungus Pleurotus ostreatus.

Three different phenol oxidases produced by the basidiomycete fungus Pleurotus ostreatus have been isolated and their main structural, enzymatic and physico-chemical properties characterized. Studies have focused on the most abundantly secreted of these proteins, a copper-enzyme specific towards ortho-diphenol substrates. This protein was purified to homogeneity and part of its primary structure determined by direct protein sequencing. The influence of pH, temperature and presence of water-soluble or water-insoluble organic solvents on the activity and stability of the enzyme were also investigated. These data can be used for applying bioreactors to problems of environmental concern such as waste-water treatment.

Amino Acid Sequence↗
PubMed1993

Low-dose dopamine induces early recovery of recombinant interleukin-2--impaired renal function.

Recombinant interleukin-2 (rIL-2) can produce impairment of renal function with hypotension, fluid retention, elevated blood urea nitrogen, oliguria and low fractional sodium excretion; these side-effects are a common cause of reduction or interruption of rIL-2 infusion. The aim of this study was to investigate the control and treatment of renal toxicity induced by rIL-2 therapy. Here we show that dopamine, at a low dose of 2 micrograms/kg/min, completely prevented renal toxicity induced by rIL-2. While continuing rIL-2 therapy, 24-h continuous infusion of low-dose dopamine produced a rapid normalisation of urine output and a significant decrease in serum creatinine levels and body weight (P < 0.01), with an early and complete recovery of the rIL-2--impaired renal function: mean recovery time of renal function in patients treated with dopamine was significantly lower (P < 0.05) than in nontreated patients (4.8 days vs. 10 days, respectively).

Adult↗
PubMed1993

Synthesis of 9,10-anthraquinone monoalkylaminoalkylhydrazones as potential antitumor drugs.

In the constant search for new compounds endowed with antitumor activity we have synthesized a series of anthraquinone hydrazones, which can bee seen either as opened-cycle modified anthrapyrazoles or as chromophore-modified anthracenediones. Seven 9,10-anthraquinone monoalkylaminoalkylhydrazones (3c-i) were synthesized from 10,10-dibromoanthrone (4) and a suitable N-alkylhydrazine. The hydrazones were converted into hydrochlorides and tested for their cytotoxic activity against L1210 murine leukemia cells. Two of them possess marginal activity in vitro.

Animals↗
PubMed1993

[New perspectives in calcium metabolism].

Although Ca in small quantities plays a fundamental role in cell activation, excessive intracellular Ca accumulation results in severe cellular damage and is a major factor in the pathophysiology of multiple diseases. Paradoxically, high Ca intake may be beneficial in unrelated disorders such as arterial hypertension, nephrolithiasis and in the prevention of colon cancer. Parathyroid hormone (PTH) could be the link capable to explain this paradox. PTH stimulates cellular calcium influx. Under normal conditions, this effect takes place only in target tissues for the hormone, but in the presence of altered cell-membrane permeability for calcium, normal plasma PTH may be detrimental, enhancing cellular calcium influx. Thus, the suppression of PTH secretion by a high Ca intake would result in a reduced PTH-induced cellular Ca accumulation in genetically predisposed tissues with a loose cellular Ca control. Thus, parathyroid ablation in dystrophic hamster reduces the elevated muscle Ca observed in muscular dystrophy and causes histological improvement without altering the serum Ca concentration. The amount of dietary Ca required is not firmly established, but anthropological observations suggest a daily intake of approximately 1600 mg, much higher than the present average Ca intake in Western societies. Thus, a higher Ca intake would be beneficial in the treatment, and more importantly, in the prevention of multiple diseases.

Animals↗
PubMed1993

The pyramidal tract of the hedgehog (Erinaceus europaeus) and its relationship with the olfactory bulb.

The pyramidal tract of the hedgehog has been investigated. The motor cerebral cortex was first located electrophysiologically and subsequently ablated. Ablation of the motor cortex did not apparently cause motor deficits. The cerebral hemisphere of the operated side, brain stem and spinal cord were removed for histological examination. The Nauta-Gygax and the horseradish peroxidase methods were employed to study the course and origin of the above mentioned tract. The pyramidal tract runs ipsilaterally in the cerebral peduncle, and does not go beyond the first cervical segments of the spinal cord (C3-C4); moreover, their fibers do not cross at spinal level. The close relation between this anatomical pathway and the olfactory bulb of the same side is also reported.

Animals↗
PubMed1992

Tumor necrosis factor alters synaptic transmission in rat hippocampal slices.

The effects of human recombinant tumor necrosis factor (TNF-alpha) on the synaptic transmission were studied in rat hippocampal slices by using extracellular field potential recordings. Population spikes and/or excitatory postsynaptic potentials were extracellularly recorded in hippocampus CA1 region from stratum pyramidale and stratum radiatum, respectively, and synaptic transmission was examined in the Schaffer collateral/commissural-CA1 pathway. Basal neurotransmission slightly and promptly increased in slices acutely exposed to TNF-alpha (1-100 nM). Examination of the long-term potentiation (LTP) revealed that a brief treatment with the cytokine did not influence LTP, while a long-lasting application of TNF-alpha (50 min or more) inhibited LTP in a dose-dependent way in the range of 1-100 nM. A role for TNF-alpha as a peptide of immunological significance belonging to the family of brain neuromodulators is discussed.

Animals↗
PubMed1992

Triggering through CD16 or phorbol esters enhances adhesion of NK cells to laminin via very late antigen 6.

Very late antigens VLA-1, VLA-2, VLA-3, and VLA-6, belonging to the beta 1 subfamily of integrins, have been identified as receptors for different binding domains of laminin (LM). We have detected VLA-6, but not VLA-1 and VLA-2 on a subset (50-70%) of fresh peripheral blood CD3-, CD16+, CD56+ human natural killer (NK) cells by immunofluorimetric and biochemical analysis. Binding assays performed on LM-coated plates showed that 10-15% of NK cells spontaneously adhere to LM, and this adhesion is mediated by VLA-6. Activation of NK cells through CD16 triggering or by phorbol ester results in a rapid increase of adhesion to LM, which is still mediated by VLA-6. The enhanced adhesiveness is not associated with changes in beta 1 LM receptor expression, while it correlates with changes in the phosphorylation status of alpha 6 subunit. The expression of VLA-6 on NK cells and the modulation of its avidity by activating stimuli may be relevant for NK cell migration and tissue location during inflammation or immune response.

Animals↗
PubMed1992

Differential expression of granzyme A and granzyme B proteases and their secretion by fresh rat natural killer cells (NK) and lymphokine-activated killer cells with NK phenotype (LAK-NK).

Granzymes A-G are a family of serine proteases localized in the cytoplasmic granules of cytotoxic T lymphocytes (Masson, D. et al. Cell 1987. 49: 679) and granzyme A is secreted by T lymphocytes in response to antigenic stimulation. Granzyme A is also expressed by natural killer (NK) and lymphokine-activated killer (LAK) cells. Here we show that fresh rat NK cells constitutively express granzyme B and that granzyme A and granzyme B are differentially regulated in unstimulated NK cells vs. LAK cells with NK phenotype (LAK-NK cells). We also show that both granzymes A and B are secreted in a calcium-dependent manner, by NK and LAK-NK cells in response to stimuli which trigger NK cell functions.

Animals↗
PubMed1992

Phorbol 12-myristate 13-acetate induces resistance of human melanoma cells to natural-killer- and lymphokine-activated-killer-mediated cytotoxicity.

Human melanoma cells are sensitive to the lytic activity of natural killer (NK) and lymphokine-activated killer (LAK) cells in vitro. The events resulting in tumour cell killing by lymphocytic effectors have not been completely clarified, and the same target cell determinants regulating responsiveness to immune cytolysis have not yet been identified. Indeed, changes in the differentiative status of leukemia cells as well as in the expression of major histocompatibility complex (MHC) antigens have been described to modulate sensitivity to cytotoxic effectors; moreover surface expression of adhesion factors or extracellular matrix proteins by the cancer cells can promote the activation of the cytolytic effectors and has been described to correlate with tumour cell sensitivity to cytolytic cells. We reasoned that treatment with differentiation inducers could modulate melanoma cell sensitivity to NK and LAK cells. The present study demonstrates that human melanoma GLL-19 cells, when treated with the phorbol diester phorbol 12-myristate 13-acetate (PMA) in vitro, undergo growth inhibition and neuron-like differentiation. Moreover, PMA treatment induces an evident inhibition of GLL-19 cell sensitivity to NK- and LAK-mediated cytotoxicity. GLL-19 cells express constitutively MHC class I antigens. PMA treatment, however, does not modify the expression of MHC class I and class II DR antigens in human melanoma GLL-19 cells. We have finally evaluated the effects of PMA on the expression at the cell surface of adhesion factors such as ICAM-1, and extracellular matrix proteins such as collagen IV, laminin and fibronectin; we have also studied the expression of the integrin vitronectin receptor, a membrane receptor for adhesive proteins. While adhesion factors and extracellular matrix proteins appear to play an important role in the interaction between immune effector and tumour target, it can be supposed that the modulation of such membrane-associated proteins or glycoproteins induces NK and LAK resistance in cancer cells. We indeed found that PMA treatment induced in GLL-19 a marked reduction of membrane expression of collagen IV and ICAM-1; moreover PMA reduced the cell membrane expression of the integrin vitronectin receptor. On the other hand, membrane expression of fibronectin and laminin was not affected by PMA. These data indicate that the acquisition of a NK- and LAK-resistant phenotype by GLL-19 cells occurs together with cell differentiation, down-regulation of membrane expression of collagen IV, ICAM-1 and vitronectin receptor, but in the absence of changes in MHC antigens.

Cell Adhesion Molecules↗
PubMed1992

The iduronate sulfatase gene: isolation of a 1.2-Mb YAC contig spanning the entire gene and identification of heterogeneous deletions in patients with Hunter syndrome.

A recently isolated cDNA clone from the iduronate sulfatase (IDS) gene has been used both to seed a contig of overlapping yeast artificial chromosomes (YACs) and to investigate the molecular defect in patients with Hunter syndrome (MPS II). Six YAC clones were found to span the IDS gene, and those and 14 other YACs were assembled into a 1.2-Mb contig around the gene in Xq27-q28. The physical map of the region identifies several putative CpG islands, suggesting the presence of other genes in the vicinity. DNA from a patient with a translocation breakpoint in the gene also permitted the orientation of the contig in the chromosome. Southern analysis of DNA from 25 unrelated Italian Hunter syndrome patients revealed 4 with deletions or rearrangements in the IDS gene.

Blotting, Southern↗
PubMed1992

Age-related modification of average volume and anisotropy of vascular smooth muscle cells.

The aim of this study was to determine what changes in the arterial wall are related to age. In two groups of rabbits, one young and one adult, the aorta and carotid were studied using a morphometric approach based on stereological axioms and planimetric morphometry. The problem of anisotropy of smooth muscle cells is discussed in detail. Two forms of anisotropy must be distinguished, that of single cell and that due to the histological pattern of the smooth muscle cells in the arterial wall. Our results show in adult animals, as compared to the young ones, statistically significant decrease in anisotropy of the cell pattern which tends to become more regular. Moreover, in aorta and carotid of young and adult animals there is an increment of 95.39% and 80% of the absolute cell volume, respectively. We suggest that there may be a direct relationship between aging and phenotypical modulation of the smooth muscle cells and that the modification of the architectural cell pattern with age may represent an adaptive event related to the change in forces acting upon the arterial wall.

Aging↗