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Biomedical subjects

G Palumbo

Publications and source records attributed to G Palumbo.

At least 163 records · Page 9Linked to original sources
PubMed1981

Direct evidence in men for a role of endogenous oestrogens on gonadotrophin release.

In six healthy subjects serum oestradiol was selectively decreased by administering an aromatase activity inhibitor, hydrotestolactone (HT). After HT administration serum oestradiol (Oe2) decreased from 18.7 +/- 2.3 (SEM) to 6.7 +/- 0.6 pg/ml whereas testosterone (T) and dihydrotestosterone (DHT) blood levels were not modified. These oestradiol changes were associated with a significant increase in serum LH and FSH concentrations (P less than 0.001). The administration of tamoxifen, an oestrogen antagonist, to 5 subjects caused a sharp increase in LH and FSH levels (P less than 0.001). Oe2 was unchanged after the treatment with tamoxifen, whereas T levels were significantly higher. The sum of these data suggests that oestradiol under physiological conditions plays a specific role in the feedback mechanism of gonadotrophin release.

Adolescent↗
PubMed1980

Human fetal insulin secretion in response to maternal glucose and leucine administration.

Maternal and fetal serum insulin response to glucose, leucine and leucine plus glucose was examined by infusions to normal pregnant women at term immediately before cesarean section. The maternal infusion of glucose (50 g) for 30 or 60 minutes was associated with a marked hyperglycemia and with a rise in serum insulin in mother and fetus. The fetal insulin response to the administration of glucose for 60 minutes was higher (p less than 0.01) than when the same dose was given for 30 minutes, while the blood glucose was lower (p less than 0.01). The maternal infusion of a smaller dose of glucose (25 g) or leucine (15 g) for 60 minutes produced an increase in serum insulin only in the mothers. However the simultaneous administration of these substances stimulated maternal and fetal insulin secretion. The fetal insulin level produced was similar to that seen after the maternal infusion of 50 g of glucose for 60 minutes, while the cord blood glucose was slightly higher but significantly different (p less than 0.01) than that seen in the saline infused group.

Dose-Response Relationship, Drug↗
PubMed1980

Concerning a new pathogenetic hypothesis of the E.P.H. gestosis (note I).

The Authors, after having evaluated the literature data, report, on the basis of their clinical experience, a new pathogenic hypothesis of the E.P.H. gestosis which would be: "Disease due to missed materno-foetal adaptation:, correlated to the activation of the maternal immunocompetent system against the "not self" antigens, carried by the trophoblast and codified by the genoma of the father's origin. It is also due to missed destruction of the tunica media of the placental bed arteries and to the thromboplastinic activity of the trophoblastic cells damaged by the immunologic reaction. This disease, clinically represents, the appearance of a "temporaneous" (pre-eclampsia) or "definitive" (eclampsia) defeat of the fibrinolytic control mechanisms against a disseminated intravascular coagulopathy.

Chorionic Gonadotropin↗
PubMed1977

Interaction of apoA-II from human high density lipoprotein with lysolecithin.

The effects of lysolecithin and hexadecyltrimethylammonium bromide on the structure and stability of apoA-II from human high density lipoprotein have been evalued by circular dichroism and fluorescence measurements. There is a profound enhancement in the stability of apoA-II to guanidinium hydrochloride denaturation when it forms a phospholipid complex with lysolecithin micelles. This complex is not only resistant to guanidinium hydrochloride denaturation, but it can be formed in a 6 M solution of this denaturant. The behavior of apoA-II in the native human high density protein is much closer to that of the lysolecithin apoA-II complex than to that of the free apoA-II.

Apoproteins↗
PubMed1976

Human maternal and fetal serum insulin and growth hormone (HGH) response to glucose and leucine.

Maternal and fetal serum insulin and HGH responses to glucose, leucine, and glucose plus leucine were examined by infusions to pregnant women at term immediately before cesarean section. Leucine (15 gm.) with glucose (50 gm.) administered for 30 minutes to the mothers stimulates markedly maternal and fetal insulin secretion while infusion of glucose (50 gm.) causes a lower insulin response. When infusing glucose alone we noted that the duration rather than the degree of hyperglycemia determined the fetal insulin response. In fact, when glucose is given to the mother for 60 minutes the fetal insulin response is higher than when the same dose is infused for 30 minutes. Maternal infusion of leucine (15 gm.) for 30 minutes elicits only a very slight increase of insulin secretion in the mother and no change in the fetus. None of the infusions causes any alteration whatsoever in either maternal or fetal HGH secretion.

Blood Glucose↗
PubMed1975

The interaction of apoA-I from human high density lipoprotein with lysolecithin.

The binding of apoA-I to lysolecithin has been studied by fluorescence and circular dichroism. The influence of the conformation of apoA-I on its interaction with lysolecithin has also been evaluated. ApoA-I is bound to lysolecithin with an association greater than 10(7) whether apoA-I is native or highly unfolded in 1.8 M guanidinium hydrochloride. The association of apoA-I with lysolecithin results in an increase in secondary structure. A 25-residue fragment of apoA-I binds to lysolecithin equally strongly as the native molecule.

Apoproteins↗
PubMed1975

The self-association of the reduced ApoA-II apoprotein from the human high density lipoprotein complex.

The molecular properties of the single linear chain form of human apoA-II, i.e., Cm apoA-II, have been evaluated by circular dichroism, polarization of fluorescence, difference absorption, and sedimentation equilibrium. The self-association of Cm apoA-II to a dimer resembles closely that of apoA-II though the free energy change is somewhat smaller. The dimerization of Cm apoA-II is accompanied by major changes in secondary and tertiary structure. The apoA-II molecule, therefore, represents a molecular association where the intramolecular structure is strongly dependent on the quaternary structure.

Apoproteins↗
PubMed1973

Relative orientation with respect to the centromere of ribosomal RNA genes of the X and Y chromosomes of Drosophila melanogaster.

We tested for recombination within the DNA that codes for ribosomal RNA (rDNA) on the X and Y chromosomes of Drosophila melanogaster. The criterion was the appearance of intermediate bb alleles on X-Y recombinants from wild bb(+) and lethal bb(1) loci carried on parental chromosomes. Recombination within the rDNA occurs only when the rDNA of the X chromosome is inverted. We conclude that rDNAs of normal X and Y chromosomes have opposite orientation with respect to the centromere. The implications of this observation are discussed.

Alleles↗
PubMedDate not supplied

A high performance liquid chromatographic procedure for the simultaneous determination of norfloxacin and furprofen in rat plasma.

A rapid and simple high performance liquid chromatographic analytical method is described for the simultaneous determination of norfloxacin and furprofen in rat plasma. Following dichloromethane extraction, the solution was chromatographed in a Vydac anion exchange column using a mobile phase of 0.05 M phosphate buffer (pH = 7.0): acetonitrile (80:20, v/v) at a flow-rate of 1.8 mL/min. The drugs were detected by UV absorption at 278 nm. The total chromatographic analysis time was 10 min. The response was linear, 0.1-5.0 micrograms/mL for norfloxacin and 0.1-3.0 micrograms/mL for furprofen, respectively. This method is useful for pharmacokinetic studies of these compounds and will facilitate detailed investigations into the interactions between quinolones and furprofen.

Animals↗