Synthesis and binding of 3-aminopyridine derivatives at central nicotinic receptors

A series of secondary and tertiary pyridyl amides as potential central nicotinic acetylcholine receptors (nAChRs) ligands were prepared. Amides displayed negligible or very low affinity, whereas two amines achieved by reduction of corresponding secondary amides, showed affinity in the nanomolar range for nAChRs.     

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. TFrs were found only in spermatocytes and early spermatids. In patients with spermatogenetic disorders, TF was always found in Sertoli cells, whereas TFrs were found in spermatocytes only when they were present. These results seem to demonstrate that in human seminiferous tubules, Sertoli cells are devoted to the production and/or storage of TF, whereas spermatocytes and early spermatids use TF.     

Characterization of N,N(Me)2-Dmt-Tic-OH, a delta selective opioid dipeptide antagonist

N,N(Me)2-Dimethyl-tyrosine-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid-OH (N,N(Me)2-Dmt-Tic-OH) is a very selective delta opioid dipeptide with elevated antagonist activity. We have radiolabelled this compound by catalytic tritiation of the N,N(Me)2-Dmt(3',5'-I2)-Tic-OH precursor. The ligand labelled rat brain membranes with a Kd value of 0.42 nM and a Bmax of 63.12 fmol/mg protein. The new tritiated ligand showed high affinity for the delta opioid receptor whereas its binding at mu and kappa opioid receptors was weak. N,N(Me)2-Dmt-Tic-OH was able to inhibit the agonist-stimulated binding of the non-hydrolysable GTP analogue ?35SGTPgammaS, thus attenuating the activation of G proteins via opioid receptors. This simple opioid dipeptide in both normal and labelled form may serve as a useful tool to study delta opioid receptors in vitro and in vivo.     

Alfa-inhibin and transferrin in human fetal testis

Aim of this research was to investigate the immunohistochemical localization of alfa-inhibin and transferrin in the human fetal testis. In addition, an attempt was made to identify the Sertoli cells in primary cell cultures of fetal testes by the demonstration of the mRNA for transferrin and the presence of the FSH receptor. 15 fetal testes (8-12 weeks) were utilized. The results of this study show: 1. In sections, immunoreactivity for alfa-inhibin was present in the interstitial cells, whereas transferrin was localized in Sertoli cells; 2. After 20 days of primary culture: a) the percentage of immunoreactive cells for both the substances was about 15%; b) the presence of FSH receptor and the expression of transferrin mRNA were observed in 12-15% of cells. These findings suggest: 1. alfa-inhibin and transferrin are present in the human fetal testis; 2. the expression of transferrin mRNA and the presence of the FSH receptor permit the identification of the Sertoli cells in primary cultures of fetal testes (8-12 weeks).     

Isolation of DNTNP, which encodes a potential nuclear protein that is expressed in the developing, dorsal neural tube.

We have performed a screen to identify genes expressed in a functionally significant anatomic region of the vertebrate dorsal neural tube, the dorsomedial roof of the third ventricle (DMRTV). The DMRTV includes the primordia of a series of circumventricular organs. The screen searched for genes preferentially expressed in the DMRTV of stage 18-25 chicken embryos, relative to their telencephala and ventral diencephalon. Through this screen, we have cloned a series of genes strongly expressed in the dorsal but not ventral neural tube. We describe here the first of these genes, DNTNP (dorsal neural tube nuclear protein). DNTNP is highly expressed in the dorsal regions of the diencephalon, the midbrain, the hindbrain, and the spinal neural tube in the chicken stage 18 embryo. Expression is also observed in the telencephalon, the branchial arches, the heart, and somites, but is absent from the presomitic mesoderm. The amino acid sequence of DNTNP reveals that it belongs to an uncharacterized protein family with at least two additional members. All the members of this family possess a basic region reminiscent of a nuclear localization signal (NLS). We demonstrate that the putative NLS of DNTNP can indeed direct nuclear localization of green fluorescent protein (GFP). The dorsal localization of DNTNP in the early embryonic central nervous system suggests roles for this molecule in specifying dorsal cell fates within the neural tube.     

Experimental keratitis in rabbits by human HSV-1 variants: prevention and treatment

The efficacy of different therapies and vaccine preparations was assessed for treating or preventing herpetic ocular keratitis induced by experimental inoculation in rabbits with two HSV-1 variants that display different pathogenetic potential. Early administration of acyclovir (ACV) promoted fast healing and prevented neurologic involvements: alpha-interferon (alpha-IFN) was less efficient than ACV; combined therapy with both drugs increased the antiviral effects. In an attempt to prevent the disease, rabbits were vaccinated with a slightly pathogenic HSV-1 variant or with a secreted form of an engineered HSV-1 glycoprotein gB (gB-1s) and were subsequently challenged with a highly pathogenic HSV-1 variant. Immunization of rabbits with gB-1s was much more efficient than immunization with live virus in reducing the severity of herpetic keratitis and in preventing CNS disease.     

Behcet's disease associated with HLA-B51 and DRw52 antigens in Italians

Thirty-eight Italian patients with Behcet's disease, all with ocular involvement, (28 complete type and ten incomplete) were typed for HLA A,B,DR, and DQ antigens. A significant increase of HLA-B51 (p less than 0.00001) and DRw52 (p = 0.045) with no significant difference between complete and incomplete syndrome was found. The involvement of B51 antigen as the main immunogenetic factor in the disease is suggested by the high value of relative risk (RR = 16.03). However, the association with the II class antigen DRw52 (RR = 2.77) cannot be easily explained as a secondary association due to linkage disequilibria with B51.