RELATIONSHIPS BETWEEN GLANDULAR AND LYMPHOID TISSUES IN HUMAN TONGUE AND PHARYNGEAL WALLS IN POSTNATAL ONTOGENESIS

The article aims for description of glandular/lymphoid interactions within digestive tract over the postnatal ontogenesis which is of special importance for clinical immunology. We have examined lingual salivary glands obtained from 299 autopsies, using macroscopic and histological techniques. Their age ranged from newborns to senile individuals; both males and females were included. The biological material was sampled at the local pathology departments at the Moscow Bureau for Forensic and Medical Expertise, according to approval by Russian federal law (No. 323, art. 47, 4180-1, 355н). The cases with pathological changes of digestive system revealed upon autopsies were excluded from evaluation. The transverse tissue sections were stained with H&E and picro fuchsin by van Gieson technique.The minor salivary lingual and pharyngeal glands, being located in the depth of tongue and pharyngeal walls, perform an important endocrine function, i.e they participate in oral immunity responses. A lot of publications concerns regenerative changes of oral mucosa caused by secretory IgA which plays a main role in regulation of local immunity. The article describes important age-dependent changes of both lingual and pharyngeal minor salivary glands. Typical scarcity of the glands in childhood may be caused by the uniform nutrition at this age, whereas decreased secretory IgA production, is generally leading to development of common inflammatory events in the oropharyngeal area. With increasing age, the glandular apertures become wider and more numerous, thus leading to increased local immunity in oral cavity and oropharynx. Sufficient involutional changes are observed in old and senile age cohorts, accompanied by diminished secretory IgA production, and, respectively, by decreased indexes of local and humoral immunity. These results are entirely reflecting topographical interrelations between the glands and lymphoid cells, and appropriate data are quite important for clinical immunology

Epidemiologic and Molecular Analysis of Human Tularemia, United States, 1964–2004

Distinct subpopulations of F. tularensis differ in their clinical manifestations, geographic distribution, and likely modes of transmission

Identification of Genes Contributing to the Virulence of Francisella tularensis SCHU S4 in a Mouse Intradermal Infection Model

Background: Francisella tularensis is a highly virulent human pathogen. The most virulent strains belong to subspecies tularensis and these strains cause a sometimes fatal disease. Despite an intense recent research effort, there is very limited information available that explains the unique features of subspecies tularensis strains that distinguish them from other F. tularensis strains and that explain their high virulence. Here we report the use of targeted mutagenesis to investigate the roles of various genes or pathways for the virulence of strain SCHU S4, the type strain of subspecies tularensis. Methodology/Principal Findings: The virulence of SCHU S4 mutants was assessed by following the outcome of infection after intradermal administration of graded doses of bacteria. By this route, the LD\u2085\u2080 of the SCHU S4 strain is one CFU. The virulence of 20 in-frame deletion mutants and 37 transposon mutants was assessed. A majority of the mutants did not show increased prolonged time to death, among them notably \u394pyrB and \u394recA. Of the remaining, mutations in six unique targets, tolC, rep, FTT0609, FTT1149c, ahpC, and hfq resulted in significantly prolonged time to death and mutations in nine targets, rplA, wbtI, iglB, iglD, purL, purF, ggt, kdtA, and glpX, led to marked attenuation with an LD\u2085\u2080 of >10\ub3 CFU. In fact, the latter seven mutants showed very marked attenuation with an LD\u2085\u2080 of 6510\u2077 CFU. Conclusions/Significance: The results demonstrate that the characterization of targeted mutants yielded important information about essential virulence determinants that will help to identify the so far little understood extreme virulence of F. tularensis subspecies tularensis.Peer reviewed: YesNRC publication: Ye