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Biomedical subjects

S Orlando

Publications and source records attributed to S Orlando.

At least 37 records · Page 2Linked to original sources

Satellite DNA sequences flank amplified DHFR domains in marker chromosomes of mouse fibrosarcoma cells.

This study centers on marker chromosomes carrying expanded chromosomal regions which were observed in two independent derivatives of the AA12 murine fibrosarcoma line, the 10(-3) M MTX-res H2 and the 5 x 10(-7) M MTX-res E. Previous characterization of the marker chromosomes of MTX-res variants showed their common derivation from a marker chromosome (m) of the parental line, endowed with two interstitial C-bands. Cytogenetic evidence pointed to one C-band of m as the site involved in the chromosomal rearrangements leading to the HSR/ASR chromosomes. ISH of a 3H-labeled satellite DNA probe allowed satellite sequences flanking the HSR/ASR in the marker chromosomes, where the C-band was no longer visible, to be detected. FISH experiments using biotinylated DHFR and satellite DNA probes showed that the respective target sequences are contiguous in new marker chromosomes. They also allowed inter- and intrachromosomal rearrangements to be seen at DHFR amplicons and satellite sequences. Double-color FISH using digoxygenated satellite DNA and biotinylated pDHFR7 showed that in a marker chromosome from the H2 cell line the two target sequences are not only adjacent, but closer than 3 Mb, as indicated by overlapping of the different fluorescence signals given by the two probes. Another marker chromosome in the E variant was shown to display a mixed ladder structure consisting of a head-to-head tandem of irregularly-sized satellite DNA blocks, with two symmetrical interspersed DHFR clusters.

Animals↗

Clinical aspects and microbiology of HIV-associated periodontal lesions.

This study examines the clinical aspects of HIV-associated periodontal lesions and the prevalence of periodontal pathogens. Subgingival plaque samples were taken from 55 subjects in six study groups: 1) HIV-seropositive patients with gingivitis, 2) necrotizing gingivitis, 3) periodontitis or 4) with health periodontium, 5) patients with rapidly progressive periodontitis or 6) periodontally healthy in whom there was no evidence of HIV infection. Among HIV-positive patients there was a majority (66%) of intravenous drug users. We detected more Bacteroides intermedius, B. buccae and B. oralis in HIV-infected patients with periodontal lesions and in HIV-negative subjects with rapidly progressive periodontitis than in the other groups. High levels of Spirochetes were recovered in both HIV associated necrotizing gingivitis and periodontitis. The results indicate that there is a similarity in the microbiological profile of HIV-associated gingivitis, necrotizing gingivitis, periodontitis and rapidly progressive periodontitis of HIV-negative subjects although significant differences in the clinical aspects of the lesions and in the immune status of the host have been observed.

AIDS-Related Opportunistic Infections↗

Idiopathic headache as a possible risk factor for phantom tooth pain.

Following tooth pulp extirpation, some subjects suffer from persistent pain which affects edentate sites in absence of any local pathology. As regards this peculiar pain, called phantom tooth pain (PTP), what is puzzling is the fact there is a low prevalence of PTP in a very large population showing identical conditions of tooth pulp extirpation. The present investigation indicates that PTP mainly affects migraine (M) and cluster headache (CH) sufferers, whereas it does not affect subjects who have a negative personal and family history for idiopathic headache (IH). These results circumscribe the presence of PTP to a specific section of the population. The present results, besides indicating that PTP may be the result of a peculiar neuronal predisposition relating to IH pathogenesis, suggests some practical therapeutic hints. In fact, successful anti- M and anti-CH prophylactic treatment greatly improve PTP syndrome.

Cluster Headache↗

[Effect of the resection margin and the extrarectal spread on the recurrence following 2 types of surgical procedures in rectal cancer].

A prospective unrandomized clinical study was conducted to determine the incidence of local recurrences after radical surgery and to ascertain whether the anterior resection could be an effective approach in cases of the tumours of the rectum, also in presence of the unsatisfied distal clearance and the extraparietal spread. For this purpose the length of the rectum below the tumor, mesorectum included, was cut in little cubes of 1 square cm and 10 microslices/cm at random were histologically examined to locate the intramural diffusion and extraparietal spread. Sixty-one patients undergoing curative surgery for rectal cancer entered the trial. Thirty-seven of them have been operated on by anterior resections (AR) and twenty-four by abdominal-perineal amputation. Thirteen local recurrences (21.3%) have been recorded during a five-year follow-up: 9 after AR and 4 after Miles operation. Nine relapses were among the cases with distal clearance less than 3 cm an eight of these have undergone anterior resections. No recurrence was seen in cases with distal clearance greater than 5 cm. Spread was found in 11 (18%) patients. Five recurrences were recorded all belonging to the group with anterior resection. No statistical difference exists between conservative surgical procedure and abdominal-perineal operation. We have been able to demonstrate only the direct relationship between relapse and Dukes C stage after curative rectal surgery.

Actuarial Analysis↗

Recurrent testicular infiltrates following radiation therapy for lymphoid malignancy.

From a group of 28 patients with biopsy-proven testicular leukemia seen at our institution since 1979, we describe two boys with lymphoid malignancy who, subsequent to 1,800 rad and 2,400 rad testicular radiation, had second overt testicular relapses. This experience suggests that these patients need careful follow-up physical examinations, that higher doses may be needed for prolonged local control, and that there may be a role for follow-up testicular biopsies.

Adolescent↗