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Biomedical subjects

R Negri

Publications and source records attributed to R Negri.

At least 55 records · Page 3Linked to original sources
PubMed1987

Neoplastic invasion of the connective stalks in transitional cell papillary tumors (TCPT) of the bladder.

Neoplastic invasion into the connective stalks of transitional cell papillary tumors of the bladder was assessed in TUR specimens from new cases. There were 21 G1 cases, none of which showed invasion of the connective tissue stalk; this compared with definite invasion in 19 of 77 G2 cases (25%) and in 16 of 17 G3 cases (94%). During a 5 year follow-up period more of the stalk invasive cases had an unfavorable course (fatal outcome or total cystectomy) than of the stalk non-invasive cases; this was statistically significant (p less than 0.01) for the whole group of patients and for the smaller group of patients with G2 tumors (p less than 0.05).

Carcinoma, Papillary↗
PubMed1987

Enhancement of immune response of murine Peyer's patches by a diet supplemented with yogurt.

The first line of defense against pathogens that enter the host by the oral route involves the Peyer's Patches (PP). For centuries many populations of the mediterranean basin have empirically administered soured milk (yogurt) to prevent and treat diarrhoea and entero-colitis. Recent reports have offered evidence in favour of a possible influence of yogurt on the host's immunocompetence. Scope of the present study was to evaluate the influence of a diet supplemented with yogurt on the PP from BALB/c mice. The results reported here suggest that yogurt feeding potentiates the host's cell-mediated immune response by increasing the percentage of B lymphocytes and the PHA and LPS-induced proliferative responses of PP cell suspensions.

Animals↗
PubMed1987

Topological properties of DNA domains and interaction with RNA polymerase II.

We have analyzed the relationship between the alterations of the DNA structure induced by topological constraint and the template properties of promoters in vitro. A cause-effect relationship has been defined in several instances. Experimental protocols have been developed for the study of the topological properties of RNA polymerase II promoters. The goal of these studies is the definition of the intrinsic structural informations of DNA.

DNA↗
PubMed1986

Structure of RNA polymerase II promoters. Coordinate conformational alteration of the upstream activator of the TATA- and RNA-initiation sequences under moderate torsional stress.

Different conformations of the circular DNA domains containing the intergenic region of the Saccharomyces cerevisiae GAL1-GAL10 divergent genes (914 base pairs) were modified by in vitro ligation in various conditions. The effect of increasing torsional stress on the conformation of the composing elements was determined by analysis of the sensitivity to the single strand-specific S1 endonuclease and it was observed that the sites of conformational alterations correspond to the positions relevant for promoter function (upstream activator sequence, TATA sequence, and RNA initiation site).

Base Sequence↗
PubMed1986

Structure of RNA polymerase II promoters. Conformational alterations and template properties of circularized Saccharomyces cerevisiae GAL1-GAL10 divergent promoters.

A DNA fragment encompassing the Saccharomyces cerevisiae GAL1--GAL10 divergent promoters (914 bp) has been circularized in vitro with T4 DNA ligase. We have defined a set of conditions that allows the production of a series of nine topoisomers covering a range from relaxed to highly negatively supercoiled DNA. Topoisomers were recovered in pure form from agarose gels and were analysed singly for the presence of sites sensitive to the single strand-specific endonuclease Pl. In this way, the occurrence of conformational alterations as a function of the linking deficiency of the closed DNA domain has been determined. Interestingly, sites of Pl hypersensitivity localize on the three sequences identified as relevant for the in vitro transcription of the GAL1 moiety of the divergent promoter: the upstream activator sequence (UAS), the TATA sequence, and the RNA initiation site (RIS). In vitro transcription with purified S. cerevisiae RNA polymerase II shows that activation of transcription parallels the appearance of conformational alterations on the UAS, the TATA and the RIS sequences.

Base Composition↗
PubMed1985

Activation of in vitro transcription and topology of closed DNA domains.

Activation of in vitro transcription of otherwise inert DNA sequences by purified yeast RNA polymerase II has been observed following the introduction in closed DNA domains of fragments of various origin. This enhancer-like effect on the in vitro transcriptional capacity is only detected in negatively supercoiled DNA domains and is characterized for each chimaeric plasmid by the superhelical density (- sigma) at which a sharp transition toward activation takes place. We have analyzed the topological state (as defined by localization and evaluation of the relative occurrence of secondary structures sensitive to S1 endonuclease) of the activated closed domains as a function of the conditions that determine the transcriptional enhancer effect, i.e. superhelical density, size, and nature of the components of the domains. We observe that variations in transcriptional capacity coincide with a defined pattern of secondary structures. These observations support a cause-effect relation between topology and regulation of transcription.

Base Sequence↗
PubMed1979

Levamisole in cancer treatment: modifications in time of cellular immunity. (Preliminary report).

Some preliminary observations are reported on a restricted case-list of patients with neoplastic disease in remission, after suitable treatment (surgical and/or radiant and/or antiblastic), treated with levamisole. The results obtained, even if preliminary, stress the close relationship between the immunorestorative effect and the length of the administration. Besides, the restoration of the secondary delayed immunity turned out promptly, in comparison with the primary delayed immunity. Very scanty the side effects observed.

Adult↗
PubMedDate not supplied

General practitioners and mammographic screening uptake: influence of different modalities of general practitioner participation. Working Group.

AIMS AND BACKGROUND: To compare the impact of different modalities of general practitioner (GP) involvement, including the introduction of target payments, on the attendance rate of organized population-based screening programs for breast cancer in Italy. STUDY DESIGN: The study was conducted between 1994 and 1996 in four Italian cities where mammographic screening programs are active: Caltanissetta (CL), Firenze (FI), Modena (MO) and Torino (TO). The impact on attendance rate of different invitation strategies based on active GP involvement was tested in each center. The additional effect of economic incentives was also assessed. The incentives were proportional to the level of compliance attained by each GP and weighted by the size of his eligible patients' list. RESULTS: In the Firenze project, an invitation signed by the GP and the project co-ordinator attained a statistically significant higher participation (difference: 4.2%, chi2 = 7.42, P = 0.006). In Caltanissetta and Torino there was a significant increase of about 7% in the response rate to the postal reminder in the groups contacted by the GPs. No difference was observed in the Modena project between the two groups. CONCLUSIONS: The main contributions of GP involvement can be: "cleaning up" the invitation lists, especially when computerized archives with the mammographic history of the target population are not available; increasing the women's participation by signing the invitation letter, by counseling and active participation in the invitation phase; co-operating in the reminder phase by recalling women non responders at first invitation. The offer of target payment had a certain impact on the screening uptake, but not easily distinguishable from GP signature of the invitation letter; further studies of appropriate design should be planned. Organizational factors, such as availability of a list of non-responders, might be crucial in order to enhance the effect of the GPs' action.

Family Practice↗
PubMedDate not supplied

["Fetal memory" in the "care" of preterm newborn infants in the incubator].

Prenatal ultrasound evaluation of non-identical twins, with a postnatal follow-up up to the age of two allowed the Author to identify a specific "fetal personality". This features is revealed by the relationships between the fetus and its environment. A review of the prenatal ultrasound videotapes at follow-up has allowed the identification of behavioral patterns clearly related to a well structured function of "fetal memory". The Author discusses several implications of the fetal memory in close relationship with clinical practice in the Neonatal Intensive Care Units.

Embryonic and Fetal Development↗
PubMedDate not supplied

The morphological characteristics and ultrastructural aspects of cervical ripening induced by sulprostone.

Cervical tissue biopsies from fifteen pregnant women who were seeking a second trimester elective abortion were examined before and after sulprostone systemic administration, to evaluate the hystological and ultrastructural modifications. While light microscopy showed an increase in vascularity and a submucosal edema with an infiltration of inflammatory cells, electron microscopy pointed out a complete dissociation of collagen fibers with a large increase of basic substance constituents. These features are similar to modifications found in the ripening process at term, demonstrating that sulprostone can be useful to prime uterine cervix.

Abortifacient Agents↗
PubMedDate not supplied

Cytologic diagnosis of prostatic malakoplakia. Report of three cases.

Three cases of prostatic malakoplakia are reported. The cytologic findings in the smears obtained by transrectal fine needle aspiration biopsy are compared with the histologic findings obtained by simultaneously performed transrectal punch biopsy. The striking cytologic finding was the presence of large isolated histiocytes with abundant foamy cytoplasm. The concentrically laminated Michaelis-Gutmann bodies that are characteristic of malakoplakia were seen both within the histiocytes and, occasionally, in the extracellular background. The smears were further characterized by a granulomatous inflammatory reaction, consisting of large numbers of polymorphonuclear leukocytes, lymphocytes and plasma cells. These findings appear to be sufficient to make a diagnosis of this rare lesion in a prostatic aspirate. To our knowledge, this is the first description of the cytology of prostatic malakoplakia.

Aged↗