ABSTRACT
Murine macrophages of the J774A.1 line are hydrogen sulphide-producing cells with the primary role of γ-cystathionase (CTH) and secondary role of 3-mercaptopyruvate sulfurtransferase (limited by cysteine availability) and with a negligible role of cystathionine ß-synthase (CBS) in H2S generation. J774A.1 cells stimulation with lipopolysaccharide (LPS) or interferon-gamma (IFNγ) resulted in decreased H2S levels after 24 h of incubation; however, they were restored to the control level after 48 h. Negligible CBS expression and activity in J774A.1 cells can result in homocysteine availability for CTH-catalyzed, H2S-generating reactions. This was supported by an increased CTH expression (IFNγ, 24 h and 48 h, and LPS, 48 h) and activity (24 h, LPS) in the stimulated cells. The results confirm the suggested feedback regulation between CBS and CTH.
Subject(s)
Hydrogen Sulfide/metabolism , Interferon-gamma/pharmacology , Lipopolysaccharides/pharmacology , Macrophages/metabolism , Animals , Cell Line , Cystathionine beta-Synthase/metabolism , Cystathionine gamma-Lyase/biosynthesis , Cystathionine gamma-Lyase/metabolism , Cysteine/metabolism , Homocysteine/metabolism , Macrophages/drug effects , Mice , Mice, Inbred BALB C , Sulfurtransferases/biosynthesis , Sulfurtransferases/metabolismABSTRACT
Numerous cases of paralytic poliomyelitis occurred during epidemic years and in interepidemic periods in recent years in the Gaza Strip and the West Bank. During the epidemics of 1974 and 1976, more than 100 paralytic cases were recorded each year. The dominant poliovirus was type 1. In interepidemic years, especially in the Gaza Strip, type 3 poliovirus was the prevalent type. The age group affected were infants and children up to 3 years and 50% of cases occurred during the first 12 months of life. Since 1968, oral poliovirus vaccine has been administered extensively to infants, 2 to 13 months of age. Though vaccine coverage was far from being complete, 3 doses of trivalent oral vaccine were given to the great majority of infants of this age group. Many of the paralytic cases occurred in unvaccinated or incompletely vaccinated (1-2 doses) children. However, numerous cases were recovered in children given three and four feedings. Serologic studies carried out on many of the paralyzed children indicated that "vaccine failures" had occurred. It seems that many of the vaccine failures were due to the massive and widespread circulation of various types of interfering enteroviruses. Laboratory tests of vaccine samples returned from the field prove that the vaccines used were undoubtedly of adequate potency. For these reasons we are planning a program of combined use of oral and inactivated vaccine in order to bypass the interference phenomenon.
Subject(s)
Disease Outbreaks/epidemiology , Poliomyelitis/epidemiology , Age Factors , Allergy and Immunology , Child, Preschool , Humans , Immunization Schedule , Infant , Israel , Poliovirus Vaccine, Oral/administration & dosage , Risk , Seasons , Time Factors , VaccinationABSTRACT
Poliomyelitis is an important problem of public health in warm-climate countries. Studies of serological responses to vaccination in these countries have given conflicting results but in many investigations the rates have been considerably less than in countries with temperate climates. In this study three possible factors influencing sero-conversion were investigated - the season of the year when vaccine was given, the social status of the mother (as indicated by the number of years of schooling) and the presence of non-poliomyelitis viruses (NPV) in the gut when vaccine was given.Over 200 children about 2 months of age were included in the study. Each was given three doses of trivalent vaccine at 6-week intervals.The sero-conversion rates of the groups fed in winter were excellent but were slightly less good in summer. The differences were greatest in children in the lower socio-economic groups and in children excreting other enteroviruses.The conclusions are that, provided a potent vaccine is used, the factors which diminish the effectiveness of immunization in warm-climate countries can be overcome: (1) by giving three doses of trivalent vaccine; (2) by beginning vaccination at the earliest possible age (when enteroviruses are fewest); (3) by concentrating special attention on the lower socio-economic groups and if necessary by giving a reinforcing dose several months after the third dose has been given - preferably in the colder months.
