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Biomedical subjects

L Marcucci

Publications and source records attributed to L Marcucci.

At least 37 records · Page 2Linked to original sources
PubMed1991

Human cells (normal and ataxia telangiectasia) transfected with pR plasmid are hypersensitive to DNA strand-breaking agents.

Ataxia telangiectasia (AT) cells are known to be hypersensitive to ionizing radiations and to drugs such as bleomycin and epipodophyllotoxin VP16, a topoisomerase II poison. Both of these produce DNA double-strand breaks even if through different mechanisms. In this work we analyzed the sensitivity to bleomycin and to epipodophyllotoxin of AT cells after transfection with pR plasmid. This plasmid, interacting with bacterial SOS repair pathways, expresses itself in mammalian cells conferring cell resistance to the SOS inducers UV and 4NQO and cell sensitivity to different drugs such as bleomycin. This effect is presumably due to the interaction of pR products with double-strand breaks. Our findings indicate that pR plasmid, in both AT lines tested (AT5BIVA fibroblasts and ATL6 lymphoblasts), expresses itself (increasing UV protection) and amplifies the already enhanced AT cell sensitivity to both bleomycin and VP16.

Ataxia Telangiectasia↗
PubMed1991

["Shark tooth" in the excision of so-called giant cell circumdigital tumors of the tendon sheaths. Results apropos of a series of 74 patients].

The authors propose an easily extended incision around the finger for giant cell tumors of the tendon sheath: two distally based triangles, one palmar, one dorsal, joining at the midlateral line. A V-Y plasty allows further enlargement and decreases the excess of skin bulkiness. Used in circumferentially extensive tumors, a decreased recurrence rate (4%) was noted compared to the classical approach (15%).

Adolescent↗
PubMed1990

Antibiotic prophylaxis in ear, nose and throat surgery: a comparison of a single preoperative dose with three peri-operative doses of ceftazidime.

An open prospective randomized trial was conducted in three Italian ear, nose and throat (ENT) surgery departments on 120 patients aged 10 to 84 years, to compare a single pre-operative dose vs. three peri-operative doses of ceftazidime in surgical prophylaxis. Sixty patients in group I received 1 g ceftazidime intramuscularly (im) or intravenously (iv) 1 h before surgery, and 60 in group II received three 1 g doses of ceftazidime, im or iv, 1 h before, and 6 and 12 h after surgery. Post-operative infections were observed in six group I patients (10.1%) and seven group II patients (11.6%). All infections arose in patients who had undergone 'moderate-risk' (6.7%) or 'high-risk' surgery (30.5%). We conclude that a single pre-operative 1 g dose of ceftazidime is as efficacious as multiple peri-operative doses in the prophylaxis of infectious complications following this type of surgery.

Adolescent↗
PubMed1990

[Tiaprofenic acid: a clinical study of 1186 patients with inflammatory ORL diseases].

A multicenter trial is presented involving 39 Italian university and hospital centers and 1186 patients (mean age 37.6 +/- 0.46 years) suffering from phlogistic aural (33.7%), rhino-sinusal (22.5%) or pharyngolaryngeal (43.8%) pathology. These patients were treated with 600 mg of tiaprofenic acid daily for a period of 7 days. The drug was administered either as monotherapy (53.2% of the cases) or in association with antibiotics (46.8%). Tiaprofenic acid showed similar therapeutic efficacy under both conditions, carrying out a clear antipyretic, anti-inflammatory, mainly analgesic action in the pathologies of all three otolaryngological areas. Treatment tolerance and compliance proved quite good. Only 20% of the patients claimed light side effects. The treatment was interrupted only in 18 (1.5%) of the 1186 patients studied.

Adolescent↗
PubMed1987

The rep region of pR plasmid regulates the expression of SOS system.

By using an artificial hybrid between phage lambda and the pR plasmid, we have shown that the rep region of the pR plasmid encodes a function which regulates the expression of the muc genes (plasmid genes that are under the negative control of lexA and responsible for an increased rate of spontaneous mutagenesis and resistance to UV and chemicals). Expression of the muc genes were monitored by a fusion between the muc promoter and the lacZ structural gene. When E. coli cells containing such a fusion are infected by the hybrid lambda pR phasmid, beta-galactosidase activity is enhanced, indicating that pR encodes an antagonist of lexA. By deletion mapping we have located the gene encoding the antagonist of lexA (bat) in the rep region of the plasmid. The bat gene product can also antagonize the lambda cI repressor as shown by the observation that lambda pR phasmids are virulent on a homoimmune lysogen. We have exploited this latter property to carry out genetic and functional analysis of the bat region. This region is organized as a classical operon where the expression of the bat structural gene is negatively regulated by a repressor gene that encodes a proteic product.

Chromosome Deletion↗
PubMed1987

Use of ceftazidime in the treatment of otorhinolaryngoiatric bacterial infections.

Within the framework of an investigation into otorhinolaryngoiatric bacterial infections in Italy conducted in 1159 patients (607 with otitis media, 354 with pharyngo-tonsillitis and 198 with sinusitis), 124 ceftazidime-treated subjects (92 with otitis media, 22 with pharyngo-tonsillitis and 10 with sinusitis) were observed. The authors report the examination of a number of microbial isolates obtained in the various forms of otorhinolaryngoiatric bacterial infection. Gram-negative organisms were found as causative agents in such diseases, particularly in otitis media. Bacterial resistance to ceftazidime was assessed in all 1159 cases and proved relatively infrequent (3.6%) and markedly less than the detected resistance to other antibiotics (10.7% resistance to cefotaxime, 35% resistance to ampicillin, 43% resistance to penicillin). Ceftazidime, used mainly in otitis media, showed very substantial clinical efficacy with positive results in as many as 97% of cases treated, which is particularly significant, if one considers that roughly 64% of the infections were caused by "difficult" gram-negative bacteria (49% by Pseudomonas).

Adolescent↗
PubMed1986

Cellular response to DNA damage is enhanced by the pR plasmid in mouse cells and in Escherichia coli.

The pR plasmid, which enhances the survival of Escherichia coli C600 exposed to UV light by induction of the SOS regulatory mechanism, showed the same effect when it transformed mouse LTA cells (tk-, aprt-). With Tn5 insertion mutagenesis which inactivates UV functions in the pR plasmid, we recognized two different regions of the plasmid, uvp1 and uvp2. These pR UVR- mutants exhibited the same effect in LTA transformed cells, demonstrating that resistance to UV light, carried by the pR plasmid, was really due to the expression of these two regions, which were also in the mouse cells. Statistical analysis showed that the expression of the uvp1 and uvp2 regions significantly increased (P less than 0.01) the survival upon exposure to UV light in mouse cells and bacteria. These results might suggest the presence of an inducible repair response to DNA damage in mouse LTA cells.

4-Nitroquinoline-1-oxide↗
PubMed1984

Premature centromere splitting in a presumptive mild form of Roberts syndrome.

Cytogenetic investigations performed on lymphocytes from a 29-year-old woman with no severe anomalies, allowed us to recognize a mild form of Roberts syndrome. The proposita's metaphases showed a consistent centromere splitting, especially affecting chromosomes 16, 19, 21, and 22. This centromere separation sequence seems to be unique to Roberts syndrome cells. The experiments also showed that no diffusible factor, involved in the mechanism of sister chromatid pairing-disjunction, exists.

Abnormalities, Multiple↗
PubMed1983

The pR UV+ plasmid, transfected into mammalian cells, enhances their UV survival.

It has been recently reported that the pR plasmid enhances the UV survival in E.coli c600. In order to test whether this function may be expressed also in mammalian cells, LTA (tk- aprt-) mouse cells were cotransformed with pR plasmid DNA and ptk1 plasmid as selectable marker. Tk+ transformants were analyzed for their UV survival and for the presence of pR DNA sequences by blot-hybridization. The results show a correlation between the enhanced UV survival and presence of pR DNA sequences in cotransformed LTA mouse cells.

Adenine Phosphoribosyltransferase↗
PubMed1981

Identification of a protein coded by pR plasmid and involved in SOS repair in E. coli.

The TP120 plasmid is known to determine enhanced UV survival in E. coli wild type an uvrB and PolA mutants but not in RecA mutant. In order to analyze the function involved in the SOS repair, we have constructed a new plasmid named pR derived by cleavage of TP120 with Hind III endonuclease. This new plasmid maintains the Ap and UV resistance. The insertion of Tn5 transposon in the plasmid allows to select several pR::Tn5 plasmids whose UV resistance was inactivated by the transposition. The comparison of the protein synthesis in the minicells of the pR and pR::Tn5 shows that the pR codes for a 22.000 M.W. dalton protein which is absent in protein pattern of pR::Tn5.

Bacterial Proteins↗
PubMed1980

Peculiar mosaicism 47,XYY/48,XYYY/49,XYYYY in man.

The chromosome analysis in a 9 years-old boy showed the presence of three cell lines : 47,XYY (28%) ; 48,XYYY (68%); 49,XYYYY (4%). Since the most frequent cells bear three Y chromosomes and the karyotype of the propositu's father is normal, it is suggest that the propositus arose from an YYY sperm and that the observed mosaicism originated from a subsequent postzygotic non-disjunction.

Child↗
PubMedDate not supplied

The pR plasmid: a tool for discriminating between DNA lesions induced by different types of cytotoxic agents in cultured mammalian cells.

The LA-D cells, obtained by cotransformation of LTA mouse cells (tk- aprt-) with pR plasmid and with tk gene as selective marker, are significantly more resistant to UV light and 4-nitroquinoline-N-1-oxide than LTA control cells. In this work, we report that the LA-D cells exhibit different degrees of response to various DNA-damaging agents: wild-type survival to mitomycin, increased sensitivity to bleomycin, cis-diamminedichloroplatinum and N-methyl-N'-nitro-N-nitrosoguanidine. The pR plasmid could, therefore, play an important role in the DNA-repair mechanisms that modulate the cytotoxic effect of the DNA-inhibitory agents. The possible interactions between pR plasmid products and the different repair enzymes involved are discussed.

Animals↗
PubMedDate not supplied

[Primary amelanotic melanoma of the nasal fossa. Importance of ultrastructural study for diagnosis].

Primitive malignant melanoma of the nasal fossae is rare and amelanotic melanoma of the same site is highly unusual. The present work reports a case where positive diagnosis was only possible by means of ultrastructural study. Giving evidence of the premelanosomes, this technique made it possible to differentiate from other types of cancers (in particular from olfactory neuroblastoma, non differentiated small cell carcinomas and lymphoma). Although in all cases we are dealing with malignancies, the need for a precise histological diagnosis is fundamental to work up an adequate therapeutic protocol. Given the difficulties in getting an electronic microscope in any hospital, the method used in the present case is quite significant since it made precise diagnosis possible even on bioptic fragments fixed in non buffered formalin. Finally some problems regarding diagnosis and treatment linked to diagnosis by means of electronic microscopy are discussed.

Aged↗