Presence of lysine at aa 335 of the hemagglutinin-neuraminidase protein of mumps virus vaccine strain Urabe AM9 is not a requirement for neurovirulence

The recent global resurgence of mumps has drawn attention to the continued need for robust mumps immunization programs. Unfortunately, some vaccines derived from inadequately attenuated vaccine strains of mumps virus have caused meningitis in vaccinees, leading to withdrawal of certain vaccine strains from the market, public resistance to vaccination, or in some cases, cessation of national mumps vaccination programs. The most widely implicated mumps vaccine in cases of postvaccination meningitis is derived from the Urabe AM9 strain, which remains in use in some countries. The Urabe AM9 vaccine virus has been shown to exhibit a considerable degree of nucleotide and amino acid heterogeneity. Some studies have specifically implicated variants containing a lysine residue at amino acid position 335 in the hemagglutinin-neuraminidase (HN) protein with neurotoxicity, whereas a glutamic acid residue at this position was associated with attenuation. To test this hypothesis we generated two modified Urabe AM9 cDNA clones coding either for a lysine or a glutamic acid at position 335 in the HN gene. The two viruses were rescued by reverse genetics and characterized in vitro and in vivo. Both viruses exhibited similar growth kinetics in neuronal and non-neuronal cell lines and were of similar neurotoxicity when tested in rats, suggesting that amino acid 335 is not a crucial determinant of Urabe AM9 growth or neurovirulence.     

Study of interaction of styrene oxide with angiotensin by mass spectrometry.

The present study describes how mass spectrometry was extensively applied to the characterization and quantification of modified amino acids within the polypeptide chain of Angiotensin I, chosen as model substrate, combining the use of fast atom bombardment mass spectrometry with gas chromatography--mass spectrometry. The reaction products after in vitro incubation of Angiotensin I with styrene oxide, a well known carcinogen, under different conditions, have been characterized: a prominent reactivity of several potential nucleophilic sites of Angiotensin I was shown, including two histidine residues and a tyrosine residue; it is worth noting that it has never been stated that tyrosine is highly reactive with styrene oxide. The results obtained demonstrate the usefulness of mass spectrometry for the structural determination of chemically modified amino acids in peptides and proteins, and the presence of a reliable relationship between reaction conditions and the production of alkylated amino acids. This characterization procedure offers the possibility of identifying reactive sites following exposure to unknown alkylating agents.     

Effects of rufloxacin in Salmonella typhimurium infection in mice.

This study was undertaken to investigate the efficacy of rufloxacin, a new quinolone which is interesting due to its pharmacokinetics characterized by a long plasma half-life, in the treatment of systemic salmonella infections in the mouse typhoid model. Innately susceptible BALB/c and resistant CBA mice were used to investigate the efficacy of rufloxacin in controlling systemic salmonella infections when given for brief or prolonged periods. The present study shows that rufloxacin is not only very effective on both mouse strains, but can completely eradicate the salmonellae from livers and spleens when given early in the infection of CBA resistant mice.     

Systematic pelvic and para-aortic lymphadenectomy in advanced ovarian cancer patients with no residual intraperitoneal disease

A comparative non-randomized study was carried out to evaluate the role of systematic pelvic and para-aortic lymphadenectomy (SL) on patients with no residual intraperitoneal disease (NRID) of advanced ovarian cancer (stage IIIC–IV). A total of 142 optimally cytoreduced patients (macroscopic disease absent on peritoneal surface) were divided into two groups: Group A, consisting of 98 patients (53 previously untreated and 45 pretreated at other Institutions), who underwent SL; Group B, consisting of 44 patients (21 previously untreated and 23 pretreated at other Institutions), who did not undergo SL. Each group had statistically equivalent histology, grading, performance status and variety of cytoreductive operations performed. Group A pretreated patients had a greater number of stage III than Group B ( P  = 0.03). Systematic pelvic and para-aortic lymphadenectomy could be carried out with an acceptable morbidity and no mortality. All 142 patients received post-operative chemotherapy including carboplatin. The number of chemotherapy sessions did not differ between the two groups. Comparison of survival revealed that SL significantly improved the survival of previously untreated patients ( P  = 0.02). The survival was significantly different with nodal status ( P  = 0.006). Cox's proportional hazard analysis showed that only systematic lymphadenectomy was a significant covariate. The survival was not significantly different in Group A vs Group B pretreated patients; however, it was significantly different with respect to nodal status ( P <0.001). Cox's proportional hazard analysis showed that only the initial stage of disease was a significant covariate. The results of the present study shows that aggressive surgical cytoreduction with SL could be therapeutic in previously untreated patients with NRID. Currently, an international prospective randomized study is ongoing to clarify definitively the clinical role of SL.     

gamma-Interferon increases metaiodobenzylguanidine incorporation and retention in human neuroblastoma cells.

Iodine-labeled m-iodobenzylguanidine (MIBG) is a widely used radiopharmaceutical for both diagnosis and biologically targeted radiotherapy of neuroblastoma. However, resistance to the radiotherapeutic effects of MIBG is often encountered, mainly due to lack of MIBG accumulation by neoplastic cells. We have investigated whether the induction of neuroblastoma cell differentiation modifies MIBG incorporation and retention. LAN-5 cells were selected, due to their moderate ability to take up MIBG. Treatment of these cells with gamma-interferon (IFN-gamma) resulted in morphological changes accompanied by a significant increase in overall cell-associated MIBG. Desimipramine, but not reserpine, easily depleted IFN-gamma-treated LAN-5 cells of their MIBG content. This suggests that the mechanism involved is an uptake enhancement rather than an improved storage ability. Indeed, IFN-gamma induces de nov synthesis of MIBG receptor-transporters, as demonstrated by polymerase chain reaction amplification and semiquantitative analysis. Our results suggest that pretreating neuroblastoma patients with IFN-gamma before MIBG administration may enhance the efficacy of both biologically targeted radioimaging and therapy of this tumor.