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Biomedical subjects

G Benagiano

Publications and source records attributed to G Benagiano.

At least 19 recordsLinked to original sources

Non-surgical female sterilization with quinacrine: an update.

The intrauterine installation of quinacrine represents a simple, inexpensive, effective, and seemingly safe method of non-surgical female sterilization. Existing clinical data on its use are very encouraging: Results of a large study conducted in Vietnam with an overall sample of over 30,000 women showed high effectiveness; in addition, when a retrospective study was conducted in these women, cumulative 5-year pregnancy rates were estimated to be 13% in women younger than 35 years and 6.8% in the women older than 35. Overall, failure rates with quinacrine have been estimated, at 10 years, to be between 1.9 and 4 times higher than those obtainable with conventional surgical procedures of tubal interruption. Unfortunately, existing toxicology for topical use of quinacrine pellets is incomplete. This prompted an expert group convened by WHO, to comment, in 1994, that the toxicology of locally applied quinacrine is inadequate. To counter this statement the proponents of the method argue that it is unfair to apply the stringent pre-clinical requirements that are mandatory in the industrialized world, to methods utilized in countries plagued by both high fertility and high maternal mortality. This controversy will soon be resolved since conventional toxicological evaluation is now underway. In conclusion, the future of quinacrine for non-surgical female sterilization will depend on the results of long-term animal studies, as well as the retrospective human studies now being carried out.

Adult↗

Effect of pH on the structure and aggregation of human glycodelin A. A comparison with beta-lactoglobulin A.

The effect of pH on the structure of glycodelin A (GdA) and of beta-lactoglobulin A (beta-LgA) has been investigated by means of circular dichroism, steady state fluorescence, synchrotron radiation small angle X-ray scattering (SR-SAXS) and gel permeation chromatography. The comparison between GdA and beta-LgA shows that, at pH 7.0, both proteins are dimers with an extended content of beta-sheet conformation, but pH 2.0 and 9.0 yield a different secondary, tertiary and quaternary structural organisation. Whilst beta-LgA is a monomer, that conserves beta-sheet conformation at pH 2.0 and 9.0, GdA has a stable dimeric structure at alkaline pH, but at pH 2.0 increases its alpha-helix content and it aggregates soon. SR beam has been used to perform SAXS comparative measurements of the two proteins. SR-SAXS data provide the radius of gyration and the radii of the cross-section and of the thickness. GdA aggregation at acid pH has been characterised by calculating the distance distribution function (P(r)). Isoelectric focusing and chromatofocusing data show a different charge distribution on the surfaces of the two proteins, supporting the hypothesis that the presence of oligosaccharides deeply influences the conformational state and the aggregation process of GdA at different pH values. In particular, the presence of sialic acid residues, within the oligosaccharide moiety of the GdA, might be responsible for the differences observed between the two proteins.

Animals↗

Decreasing the need for abortion: challenges and constraints.

Voluntary abortion is the most controversial act in the entire field of medical practice, although today, it is a practice that, under different conditions, has been legalized in more than 100 countries, mostly in the developed world. The United Nations has agreed that in no case should abortion be promoted as a method of family planning and, therefore, it should be utilized only when contraception has failed. Overall, 61% of humanity lives in countries where abortion is legal and widely available; 14% in countries where termination is allowed to protect a woman's health; physical, mental, or both; 21% in countries where it can be performed only to save the mother's life and 4% in countries where abortion is not permitted at all. Restrictive legislation, per se, does not represent a valid deterrent to prevent abortion, while it may contribute to an increase in morbidity and mortality associated with pregnancy. In addition, because abortion is outlawed, nothing is done to actively reduce the reasons leading to it. Indeed, the countries with the lowest abortion rates are those where, on the one hand, pregnancy termination is legal and, on the other, sex education and contraceptive knowledge are widely spread.

Abortion, Illegal↗

The endometrium and hormonal contraceptives.

Contraceptive progestogens have a series of effects on the endometrium that depend on the existence of oestrogen priming and therefore on the time of administration, the route through which the hormone is released to the body (systemic or locally in utero) and the available daily dose. The effects of a contraceptive progestogen can be divided into two main categories: changes in the endometrial structure and vascularization and alterations of the menstrual bleeding pattern. Whereas orally administered progestogens usually cause endometrial decidualization and an important stromal reaction, the i.m., or local, intrauterine delivery is more apt to cause atrophia. Finally, all progestogens, when given alone at contraceptive doses (and irrespective of their mechanism of action), cause some disruption of menstrual bleeding patterns. This is maximal with injectable, long-acting progestogens, such as depot-medroxyprogesterone acetate and norethisterone enantate.

Contraceptive Agents, Female↗

Rapid purification and properties of human glycodelin (endometrial alpha2-globulin).

The method presented can easily produce milligram amounts of glycodelin from pregnancy endometrium, with a 19% yield. It involves anion-exchange chromatography, gel permeation and chromatofocusing; it results in one stainable band at Mr 28,000 after sodium dodecyl sulphate-polyacrylamide electrophoresis, as well as after immunoblot analysis, performed using an affinity-purified IgG fraction from an antiserum against glycodelin. In spite of this, the corresponding gel isoelectric focusing pattern gives four stainable bands with pI values between 4.55 and 5.2. Western immunoblot analysis of tissue extracts indicates the presence of glycodelin epitopes associated with materials heavier than the native protein. Circular dichroism spectra of the highly purified protein in water solutions indicate a large amount of beta-sheet conformation, whereas those obtained with different proportions of 2-propanol in water, show an increased proportion of alpha-helix conformation.

Anions↗

Comparative clinical evaluation of the effect on carbohydrate and lipid metabolism of two norethisterone-containing hormonal contraceptives: Mesigyna and TriNovum.

The effect on carbohydrate and lipid metabolism of two hormonal contraceptive preparations containing norethisterone (commercially known as Mesigyna and TriNovum) was studied in a total of 60 women, before and after 6 months of treatment. Carbohydrate metabolism was evaluated by means of a euglycemic glucose clamp test; lipid metabolism was monitored by measuring total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, and triglycerides. The two groups were properly matched with the exception of pretreatment levels of cholesterol and LDL-cholesterol. At the end of treatment, no difference was found within or between groups in fasting glucose and insulin levels and in glucose rate of disappearance. A significant increase in total cholesterol, HDL-cholesterol, and VLDL-cholesterol was found in both groups at the end of the treatment period; in addition, TriNovum caused a significant increase also in triglycerides. In conclusion, the safety of both preparations with regard to carbohydrate metabolism was confirmed using the most accurate method available; furthermore, changes in lipid metabolism were such as to have little clinical significance.

Adolescent↗