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Biomedical subjects

A Lanza

Publications and source records attributed to A Lanza.

At least 55 records · Page 3Linked to original sources
PubMed1996

Human DNA topoisomerase I-mediated cleavages stimulated by ultraviolet light-induced DNA damage.

DNA topoisomerases have been proposed as the proteins involved in the formation of the DNA-protein cross-links detected after ultraviolet light (UV) irradiation of cellular DNA. This possibility has been investigated by studying the effects of UV-induced DNA damage on human DNA topoisomerase I action. UV lesions impaired the enzyme's ability to relax negatively supercoiled DNA. Decreased relaxation activity correlated with the stimulation of cleavable complexes. Accumulation of cleavable complexes resulted from blockage of the rejoining step of the cleavage-religation reaction. Mapping of cleavage sites on the pAT153 genome indicated UV-induced cleavage at discrete positions corresponding to sites stimulated also by the topoisomerase I inhibitor camptothecin, except for one. Subsequent analysis at nucleotide level within the sequence encompassing the UV-specific cleavage site revealed the precise positions of sites stimulated by camptothecin with respect to those specific for UV irradiation. Interestingly, one of the UV-stimulated cleavage sites was formed within a sequence that did not contain dimerized pyrimidines, suggesting transmission of the distortion, caused by photodamage to DNA, into the neighboring sequences. These results support the proposal that DNA structural alterations induced by UV lesions can be sufficient stimulus to induce cross-linking of topoisomerase I to cellular DNA.

Base Sequence↗
PubMed1996

Comparative evaluation of two serologic typing methods for hepatitis C virus.

Serologic methods of typing for hepatitis C virus offer advantages over PCR-based typing methods in terms of speed and simplicity of sample preparation and in the use of standard laboratory equipment. We examined the sensitivities and specificities of two hepatitis C virus serotyping assays which use sets of type-specific antigenic peptides derived from the core or the nonstructural 4 (NS4) regions and compared the results with those of molecular typing with type-specific primers from the core region. Although there was a good concordance between serotyping by either assay and genotyping, we found that the sensitivities of both serologic assays were less than optimal compared with that of molecular typing, with only about 50% of samples being unequivocally typed. Moreover, amino acid sequence similarities within the regions of the genome used for serotyping preclude differentiation into subtypes, which may have important clinical and therapeutic implications.

Adolescent↗
PubMed1996

Species belonging to the "Streptococcus milleri" group: antimicrobial susceptibility and comparative prevalence in significant clinical specimens.

The association between the three species belonging to the "Streptococcus milleri" group and different sites of isolation was examined for 73 successive strains recovered from clinically significant, purulent infections. Susceptibility testing was performed on 64 of these strains. The present study supports the association of particular species with different clinical sources. Susceptibility data suggest that emerging penicillin resistance among Streptococcus anginosus and Streptococcus intermedius isolates may represent a potential clinical problem in the therapeutic management of infections caused by these species.

Anti-Bacterial Agents↗
PubMed1996

Cervical cerclage for the treatment of patients with placenta previa.

Over a ten year period, placenta previa occurred in 103 instances among 12,965 deliveries. In six of these, cervical cerclage was undertaken to prevent severe bleeding while prolonging pregnancy between the 24th and the 30th weeks of gestation, according to the McDonald technique. We performed cesarean section delivery in all cases. The medium prolongation of the pregnancy was of 8.2 weeks and the foetus weighed from 1,820 to 3,360 g. No complications due to fetal respiratory distress were observed. No patients needed transfusions. Postpartum and the puerperium were regular. These results support the use of cervical cerclage for the treatment of patients with symptomatic placenta previa early in gestation.

Cervix Uteri↗
PubMed1996

Endometrial carcinoma in women 45 years of age or younger.

Adenocarcinoma of the endometrium in patients 45 years or age of younger accounts for 21% of all endometrial neoplasms diagnosed. The clinical and pathological findings in 17 cases of endometrial adenocarcinoma patients aged 45 years or younger treated between January 1976 and December 1992 in Department B of the Gynecologic and Obstetric Institute, University of Torino, Italy are reported. The patients age ranged from 31 to 45 years, with a median age of 39.3 years. Thirteen of the 17 neoplasms (76.4%) were stage IB (FIGO 1988), two (11.7%) stage IIB, one (5.8%) IIIC and one IVA. Histologically all patients had endometrial adenocarcinoma, eight were well-differentiated tumors (G1), six were moderately-differentiated tumors (G2) and three poorly-differentiated tumors (G3). Three of the patients treated from 1976 to 1979 received post-operative administration of 17-hydroxiprogesterone-19-norcapronate (500 mg i.m. weekly for one year) and 14 of the patients treated from 1980 to 1992 received, according to neoadjuvant hormonal protocols, Medroxiprogesterone acetate (MPA) 1,000 mg daily per os for 90 days and 500 mg per os for one year. The aim of this paper is to draw attention to the existence of this neoplasm in an unexpected age range.

17-alpha-Hydroxyprogesterone↗
PubMed1996

Reduced IL-2 level concentration in patients with breast cancer as a possible risk factor for relapse.

Reduced interleukin 2 (IL-2) production has been described as one of the most frequent immune dysfunctions observed at relapse in patients with disseminated solid neoplasms. It was seen that patients treated for breast cancer (NED-no evidence of disease- at check-up) have a relapse percentage of 4.7% if the IL-2 plasmatic level is normal while the relapse percentage increased to 33.3% if it is low after a 10-12 month follow-up. This link between low IL-2 and the host immune response is a new prognostic indicator and one not strictly related to the tumour itself.

Adult↗
PubMed1996

Management of patients with intrauterine fetal death.

Fetal death incidence is 5-10 per 1,000 births. About 25% of the women who carry a dead fetus for more than 4 weeks will show significant alterations in their coagulation system. The treatment for a patient with endouterine fetal death depends on when the pregnancy is terminated, based on the ecographic fetus age. There were 15,070 births from January 1983 to December 1994 in Department B of the Institute of Obstetrics and Gynecology, University of Torino. We took into consideration the cases ofintrauterine fetal death between the 26th and 40th week before labour. This study is based on a cohort of 57 cases of intrauterine fetal demise from the 24th to the 40th week of pregnancy before spontaneous labour.

Abortion, Therapeutic↗
PubMed1995

[The malignant transformation of leukoplakia of the oral cavity. A review of the literature and clinical case reports].

After considering the leukoplakia as defined by the WHO, the authors examine the quantitative, qualitative, histopathologic and clinical aspects of leukoplastic lesions. Afterwards, the data concerning the incidence of the malignant evolution of leukoplakia are shown. Data that have been collected and shown during years of study and that are often discordant. For this reason a study on the literature since 1931 is carried out and all the possible causes that could have led to different results are mentioned. Than the authors, among 98 cases of leukoplakia, examine those that turned malignant. In five cases, after the first biopsy, the histopathological report found the presence of microcarcinoma while, in three other cases, in the follow-up, a malignant evolution was observed. This This study points out a percentage of malignant transformation of the leukoplakia equal to 2,94% in agreement with the study of Pindborg and Banoczy.

Aged↗
PubMed1995

[The therapy of leukoplakia of the oral cavity. A review of the literature].

The authors examine the different therapeutic approaches that can be used to treat the leukoplakia of the oral cavity by examining the literature and doing a critical evaluation. Great importance is attached to methods like CO2 laser therapy, to the treatments with natural or synthetic retinoids, and at last, but not least traditional surgery. These seem to be the most efficient treatments. The data reported seem to confirm the role of surgery (traditional, laser) and the validity of pharmacological therapy with retinoids. On the other hand it is not possible to find long term follow up with bleomycin, selenium and beta interferon, even if at the beginning they seemed to be arouse lively interest.

Antineoplastic Agents↗
PubMed1995

[Calcifying odontogenic cyst. A clinical case].

The calcifying odontogenic cyst (COC) is a rare lesion that involves the jaws which, at times, may evolve into a solid, benign, tumor-like mass. There is no significant sex predilection, but it is probably more common in later life. The diagnosis is base only on histologic examination that represents, in the best of cases, the only way to differentiate the COC from other pathologies. Such lesions include: odontogenic cyst, residual cyst, globulomaxillary cyst, lateral periodontal cyst, ameloblastoma (multicystic and unicystic), odontogenic mixoma, and still with calcifying odontogenic epithelial tumor (Pindborg tumor) and adenomatoid odontogenic tumor. The authors report a case of COC, starting point for a review of the clinical, radiographic and histomorphologic features of the lesion.

Calcinosis↗
PubMed1994

The ultimate carcinogen of 4-nitroquinoline 1-oxide does not react with Z-DNA and hyperreacts with B-Z junctions.

DNA secondary and tertiary structures are known to affect the reaction between the double helix and several damaging agents. We have previously shown that the tertiary structure of DNA influences the reactivity of 4-acetoxyaminoquinoline 1-oxide (Ac-4-HAQO), the ultimate carcinogen of 4-nitroquinoline 1-oxide (4-NQO), being more reactive with naturally supercoiled DNA than with relaxed DNA. The relative proportion of the three main stable adducts and of an unstable adduct, that resulted in strand scission and/or AP sites, was also affected by the degree of supercoiling of plasmid DNA. In this study we examined the influence of Z-DNA structure on the reactivity of Ac-4-HAQO by mapping the distribution of the two main Ac-4-HAQO adducts, C8-guanine and N2-guanine, along a (dC-dG)16 sequence inserted at the BamHI site of pBR322 plasmid DNA. This insert adopted the left-handed Z and right-handed B structure depending on the superhelical density of the plasmid. Sites of C8-guanine adduct formation were determined by hot piperidine cleavage of Ac-4-HAQO modified DNA, while N2-guanine adducts were mapped by the arrest of the 3'-5' exonuclease activity of T4 DNA polymerase. The results showed that Ac-4-HAQO did not react with guanine residues when the (dC-dG)16 sequence was in Z conformation, while hyperreactivity at the B-Z junction was observed. These results indicate that Ac-4-HAQO can probe the polymorphism of DNA at the nucleotide level.

4-Nitroquinoline-1-oxide↗
PubMed1994

Microinvasive carcinoma of the uterine cervix. Diagnostic and therapeutic dilemma.

Squamous microcarcinomas of the uterine cervix represent a focus of controversy regarding a useful clinical definition. The confusion of terminology and numerous pathological definitions have led to a great variety of surgical treatments from the cone to the radical hysterectomy, with pelvic adenectomy. This report analyses retrospectively 133 cases of Stage IA cervical cancers which have been followed up for 10-240 months. The purpose of this work is to seek a uniform therapeutical approach to cervical microcarcinoma with the review of International Literature.

Carcinoma, Squamous Cell↗