Chronobiologic aspects of recurrent transient ischemic attack.

An epidemiologic study was conducted from 1979 through 1984 on subjects presenting transitory ischemic attacks (TIA) and admitted into our Institute. We investigated year, season, month, day, and hour of every attack on 80 patients aged between 51 and 88 years. Time-series analysis showed a seasonal pattern of disease onset in early spring.

Synthesis and biological activity of carboxyl terminally extended dermorphins.

Dermorphinoyl(DMR)-glycine, DMR-sarcosine and DMR-glycyl-arginine have been prepared in order to examine the effect of C-terminal extension of dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2) on opioid activity. On GPI preparation the addition of Gly, Sar, or Gly-Arg to the carboxyl terminus of dermorphinoic acid was detrimental to mu activity: dermorphinoyl-derivatives, in fact, retain only 5-20% of dermorphin potency. Following intracerebroventricular administration (tail-flick test), whereas the analgesic activities of compounds showed the trend dermorphin greater than DMR-Sar greater than DMR-Gly-Arg greater than DMR-Gly greater than morphine, the nonapeptide displayed highest activity after subcutaneous injection in mice: DMR-Gly-Arg was 2.

Dehydro-dermorphins. II. Synthesis and biological activity of unsaturated dermorphin hexa and heptapeptides.

The Phe3 and/or Tyr5 residues in dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2) and its N-terminal hexapeptide-amide were replaced by delta-Phe or by Phe5 in order to examine the effect on opioid activity. On GPI preparation, the substitution of Phe5 for Tyr5 was well tolerated, whereas the hexa and heptapeptides containing delta Phe in position 3 and/or 5 displayed low potency. The unsaturation at position 3 alone or at positions 3 and 5 was particularly detrimental to mu activity.

Dehydro-dermorphins. I. Influence of the stereo-orientation of aromatic groups in dermorphin-(1-5)-peptides to opioid activity.

Dehydrophenylalanine having the Z-configuration (delta Phe) and D-Phe were incorporated in positions 3 and/or 5 into dermorphin-(1-5)-peptide amide (H-Tyr-D-Ala-Phe-Gly-Tyr-NH2) in order to study the effect of structure or configurational changes. On GPI preparation, whereas the activity of [L-Phe5]-pentapeptide was fourfold higher than parent peptide and comparable to that of dermorphin, the substitution of Phe3 by its D-enantiomer was barely tolerated. The pentapeptides containing delta Phe in positions 3 and/or 5 displayed even lower potency: particularly the unsaturation at position 3 alone or at position 3 and 5 was very detrimental to mu activity.

Dehydro-dermorphins. III. Circular dichroism investigation of conformation in solution.

Dehydropeptide analogs of dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2) and N-terminal fragments containing one or two dehydrophenylalanine residues in the 3rd and/or 5th position, have been investigated by means of CD spectroscopy. The results indicate that the above dehydropeptides can adopt different conformations in alcohol and water solutions. In methanol and trifluoroethanol, the CD spectra are mainly consistent with the presence of folded structures, probably stabilized by intramolecular hydrogen bonds.

Synthesis and opioid activity of dermorphin tetrapeptides bearing D-methionine S-oxide at position 2.

Eight new dermorphin tetrapeptides, X-Tyr-D-MetO-Phe-aa-Y (X = H, H2N = C(NH); aa = Gly, 2-aminoethanol, sarcosine; Y = NH2, NH-alkyl), were prepared and tested for opioid activity. They show dose-related naloxone-reversible opioid effects in vitro and in vivo. H-Tyr-D-MetO-Phe-Gly-NH2 (I) (guinea pig ileum IC50 = 13.

Immunostaining of transferrin and transferrin receptor in human seminiferous tubules.

Transferrin (TF) and transferrin receptor (TFr) were studied in human testicular biopsy specimens with the use of immunostaining techniques. A polyclonal antibody to human TF (obtained in goat), a murine monoclonal antibody (B3/25) to human TFr, and antisera antigoat IgG and antimouse IgG, both labeled with peroxidase, were used. In seminiferous tubules of subjects with normal spermatogenesis, TF was found mainly in Sertoli cells and, in lesser amounts (probably related to the presence of receptor-TF complexes), in spermatocytes and early spermatids.

Erythropoietin levels in heterozygous alpha-thalassemia.

In guinea pig bone marrow cultures with heterozygous alpha-thalassemic serum, 59Fe uptake values are elevated above iron values of cultures with serum of normal subjects. These results show that erythropoietin (EP) activity values in heterozygous alpha-thalassemia are comparable to those previously observed by ourselves in heterozygous beta-thalassemia despite of the different Hb concentration in these thalassemic syndromes. This points to the existence of signals which regulate Ep synthesis independently of Hb levels.

Opioid peptides. VIII. Synthesis and preliminary biological activity of [D-Phe3]- or [alpha,beta-dehydro-Phe3]dermorphin tetrapeptides.

We describe the synthesis and preliminary in vitro pharmacological testing of two new tetrapeptide analogues of the opioid heptapeptide dermorphin H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2. The replacement of Phe3 by its D-enantiomer was hardly if at all tolerated. The unsaturated analogue carrying the phenyl ring of the delta Phe3 residue in the Z-configuration, was almost inactive.

Synthesis and pharmacological activity of partially modified retro-inverso dermorphin tetrapeptides.

We studied the effect of partial retro-inverso modification of selected peptide bonds of N-terminal tetrapeptide analogues of dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2). Among the 14 compounds synthesized and tested for opioid activity, some tetrapeptides have the C-terminus carrying different amide moieties; retromodifications concern the Phe-Gly bond (Ia-f) and/or the C-terminal carboxamide function (IIIa-d, IIa-d). All pseudotetrapeptide derivatives showed opioid activity in vitro and in vivo.

Synthesis and opioid activity of partial retro-inverso analogs of dermorphin.

We studied the effect of partial retro-inverso modification of selected peptide bonds of dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2. The modifications concern two consecutive peptide bonds (Phe3-Cly4-Tyr5, I) or a single one (Gly4-Tyr5-, II or Phe3-Gly4, III). All pseudoheptapeptides showed low opioid activity in the in vitro and in vivo tests.

[Effect of laser irradiation on collagen production by fibroblasts in vitro].

The effects of the low power laser irradiation (Space Mix 5 Mid Laser) on the 3H-proline incorporation in the collagenic proteins produced by two lines of normal human fibroblasts in vitro were studied. The 3H-thymidine incorporation in cultures of control and irradiated fibroblasts of the same lines was also evaluated. The obtained results show that in the experimental conditions considered, laser irradiation may have a positive effect on the production of collagen by the fibroblasts in vitro.

Structure-activity relationships of dermorphin tetrapeptides carrying a ketomethylene linkage.

The synthesis and in vitro pharmacological tests of 5 ketomethylene tetrapeptide analogues of the opioid heptapeptide dermorphin H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2 are described in this study. The substitution of the original Phe-Gly peptide bond (-CO-NH-) by the ketomethylene linkage (-CO-CH2-) provided analogues with reduced opioid activity.

Synthetic tetrapeptides related to dermorphin: potent long lasting analgesic action following subcutaneous administration.

To examine the opioid properties of D-MetO2-dermorphin tetrapeptides, eight new analogues based on the following formula, X-Tyr-D-MetO-Phe-aa-Y, were prepared. All these peptides show dose-related naloxone-reversible opioid effects in vitro and in vivo. Substitution of Sar or Gly-ol for Gly4 were well tolerated by the isolated guinea pig-ileum preparation as well as in the tail-flick test, while alkyl-amidation of the C-terminal proved detrimental.

Synthesis and opioid activity of [Sar4]dermorphin-tetrapeptide analogues.

The modification of the dermorphin-(1-4)-tetrapeptide structure led to analogues with potent opioid activity in vitro and in vivo. [Sar4]Tetrapeptides such as H2N-CH(NH)-Tyr-D-Ala-Phe-Sar-D-NH-CH(CH3)C6H5 (VII) whose terminal amino group is replaced by the guanidino function and whose C-terminus is amidated by (R)-(+)-alpha-methylbenzylamine, show peripheral and central opioid activities comparable to or higher than those of dermorphin. The potency of VII in the different tests was as follows: guinea-pig ileum (GPI) IC50 = 0.

Opioid peptides. Structure-activity relationships of dermorphin endothiotetrapeptides. VII.

We describe the synthesis and preliminary in vitro and in vivo pharmacological tests of five endothiotetrapeptide analogues of the opioid heptapeptide dermorphin H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser.-NH2. The modification obtained by substituting Phet for Phe3 or Glyt for Gly4 provided further analogues with significant opioid activity.

Erythropoietin levels in heterozygous beta-thalassemia.

In the present work the capacity of serum of beta-thalassemic heterozygous and normal subjects to stimulate 59Fe uptake into heme in guinea pig bone marrow cultures is analyzed. The results show that labelled iron uptake is higher in cultures with thalassemic serum than in cultures with normal serum. No correlation between labelled iron uptake and Hb level or sex has been found in either group.

[Relaxin in ovarian follicles].

Since the first observations of HISAW, the knowledge on the chemistry and the biological properties of relaxin improved in an important way. It is now well known that relaxin is a peptide hormone, strictly related to insulin. The extraction and purification of porcine relaxin and the application of radio-immunological and immuno-histochemical methods have provided a lot of data concerning the activity and the sites of production of the hormone.

[Dark cells of the rat olfactory epithelium].

Two types of basal cells can be identified in the olfactory epithelium: a) the clear basal cells, round in shape, which are true stem cells capable of giving rise to the olfactory and the supporting cells; b) the dark basal cells characterized by a very irregular shape and by the presence in the cytoplasm of numerous mitochondria and bundles of microfilaments. In the aim of interpreting the significance of these dark cells we studied them with the light and electron microscope in the olfactory epithelium of male and female prepubertal and postpubertal rats. The nature of the microfilaments was investigated with the indirect immunofluorescence method for prekeratin and actin.

[Mast cells in rat lymph nodes].

The histochemical and ultrastructural features of mastocytes have been studied in rat parathymic, para-aortic, inguinal and mesenteric lymph nodes. 1) In the parathymic lymph nodes, as well as in the lymph nodes of other sites in the body, all the stages of evolution of mastocytes may be detected, related to a progressive sulfation of the granular mucopolysaccharides. 2) It can be suggested that in the rat lymph nodes a genesis of mastocytes, probably from undifferentiated mesenchymal elements, might occur.