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Biomedical subjects

S Ledda

Publications and source records attributed to S Ledda.

45 records · Page 3Linked to original sources

[Histological follow-up after implantation of grains of I-125 for prostatic cancer].

The authors report a preliminary study of 12 cases of carcinoma of the prostate confined to the prostate (T1, T2, T3, NO, MO) treated by pelvic lymphadenectomy and the implantation of grains of I 125 in the prostatic tissue. Irradiation continued for six months, providing most dose of 100 Gy in the prostate. Interstitial irradiation caused not only the destruction of tumour cells but also "radiation prostate" lesions with vascular obliteration which itself caused sufficient impairment of the vitality of the prostatic tissue for any residual tumour to disappear with a frequency which increased with the time elapsing between the follow up prostatic biopsy and the implantation of radioactive iodine. Experience remains limited but the initial figures given here suggest the validity of continuing along these lines.

Adenocarcinoma↗

[Use of common glass in radiation protection].

The X-ray absorption meter (Diagnostic energy between 20-60 Kev) of common place-glass has been studied. The possibility of replacing lead glass with a reinforced type, also very cheap, has been examined.

Absorption↗

Embryo transfer and related technologies in sheep reproduction.

This paper reviews the status of embryo transfer and the major technologies applied to preimplantation of embryos in sheep. Embryo production from superovulated ewes is hindered by an unpredictable response to hormonal treatment. Progress in this area should be expected by an appropriated control of follicular development with gonadotropin-releasing hormone (GnRH) agonist or antagonist prior to gonadotrophin administration. Simple protocols for the cryopreservation of sheep embryos by vitrification are already available and the development of frozen-thawed blastocysts to term is close to the fresh ones. Further research is required to identify factors able to promote the maturation in vitro of oocytes, namely those obtained from prepubertal animals. Semen and embryo sexing procedures are available in cattle although much less attention was paid to their application to sheep. Among all the reproductive technologies, cloning with embryonic and foetal cells has progressed dramatically in sheep and nuclear transfer has been used to produce transgenic animals as an alternative to pronuclear injection. The production of the first lamb cloned from a somatic cell opened new opportunities in animal breeding as well as exciting lines of basic research. The overall conclusions are that, apart from superovulation, the application of in vitro technologies is likely to evolve rapidly and once applied, a great impact on traditional and new animal productions should be expected. However, a better understanding of the changes in gene expression, induced in embryos by different in vitro manipulation procedures, is necessary to prevent abnormal foetal development.

Animals↗

Follicular size affects the meiotic competence of in vitro matured prepubertal and adult oocytes in sheep.

Non-atretic follicles dissected from prepubertal and adult ovaries were allocated in three groups: a) < 1 mm; b) 1-2 mm; c) > 2 mm. After 24 h of maturation, a lower percentage of adult oocytes from group a (P < 0.01) reached metaphase II than those from groups b and c (70.4 versus 89.5 and 95.5). Prepubertal oocytes showed similar results (P < 0.01; 27.2 versus 79.8 and 81.8). There was a significant difference (P < 0.01) in meiotic progression between prepubertal and adult oocytes of < 1 mm follicles. The diameter of prepubertal oocytes derived from group a was significantly lower (P < 0.01) compared to groups b and c (138.1 versus 142.1 and 145.6); adult oocytes showed similar results (P < 0.01; 142.2 versus 157.2 and 158.1). Oocytes with the same diameter derived from different follicles of prepubertal and adult ovaries showed similar meiotic progression rates.

Animals↗

Sheep embryos derived from FSH/eCG treatment have a lower in vitro viability after vitrification than those derived from FSH treatment.

In the non breeding period, the effect of two superovulatory treatments (eCG/FSH in single dose or FSH alone in four decreasing doses) on the production of embryo quality following in vitro viability after vitrification procedures was investigated using forty-four adult Sarda breed ewes. In sheep treated with eCG/FSH, the mean number of corpora lutea was significantly (P < 0.05) higher (11.8+/-4.0 vs. 8.05+/-3.8), although the recovery rate was significantly (P < 0.01) lower (74.6 vs. 59.9) than with FSH alone. After vitrification (ethylene glycol and glycerol) was repeated three times, the rates of re-expansion at first and second warming were significantly (P < 0.01) higher in embryos derived from FSH alone than in those with both gonadotrophins (94.9 and 41.9 vs. 72.8 and 18.6) and after the last vitrification the hatched blastocyst rates were 22.5 and 7.6. After differential stain, blastocysts derived from FSH alone showed a mean number of cells significantly higher than blastocysts from eCG/FSH (184.2 vs. 157.7). It was concluded that superovulatory treatment with eCG/FSH may increase the ovarian responses compared with FSH alone, but these embryos showed a reduction in viability rates after repeated vitrification.

Animals↗

[The general surgeon facing acute abdomen caused of gynecologic cause: diagnostic and therapeutic considerations on 2 cases].

The general surgeon has sometimes to face problems arising from an acute abdomen due to gynecologic causes. Such conditions are mainly found in women in reproductive age; the most frequent pathologies are due to complications of ovarian cysts, perlvic inflammatory disease and extrauterine pregnancy. Some short clinical commentaries are herein presented on two cases of gynecologic acute abdomen: the first case reported is related to an intraperitoneal rupture of a large uterine sarcoma and the second an ovarian neoplasm associated with a diffuse peritonitis from perforation of tubo-ovarian abscess.

Abdomen, Acute↗