Recovery of the extensor digitorum longus muscle in the rat following L4 nerve sectioning

The purpose of this study was to define the time course and the extent of recovery of muscle weight and tension in the extensor digitorum longus (EDL) muscle following partial denervation in nine-week-old male rats (300 to 325 g). The L4 nerve underwent unilateral sectioning while the opposite side served as a sham-operated control. The muscle weight and tension of the control and the partially denervated group were examined at two (n = 15), eight (n = 15), 12 (n = 15), and 16 (n = 15) weeks after L4 nerve sectioning. The partially denervated muscle weights as a percentage of respective controls were 58.6%, 56.1%, 68.4%, and 61.9% at two, eight, 12, and 16 weeks after L4 nerve sectioning. There was no significant difference (p > 0.05) between these percentages at the respective time intervals. The tetanic tensions compared with their respective matched controls were 14.5%, 32.8%, 50.0%, and 32.4% at these respective time intervals (p < 0.05). The muscle weight (MW) and muscle weight/body weight (MW/BW) of the partially denervated side as a percentage of its contralateral control remained unchanged throughout the duration of the experiment. The twitch tension (Pt), tetanic tension (Po), Pt/Po, and the Po/MW of the partially denervated muscle relative to its matched control increased between the second and the eighth week post-partial denervation (p < 0.05). After the eighth week post-L4 nerve sectioning, there was no further increase in these parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

Heterotypic protection of mice against chlamydial salpingitis and colonization of the lower genital tract with a human serovar F isolate of Chlamydia trachomatis by prior immunization with recombinant serovar L1 major outer-membrane protein

Intrauterine infection of mice with a human genital tract isolate of Chlamydia trachomatis (serovar F) resulted in salpingitis. In some cases, oviduct damage was sufficient to cause infertility due to lumenal blockage. Parenteral immunization with a purified, heterologous, recombinant major outer-membrane (rMOMP) preparation reduced the proportion of animals developing severe salpingitis by 77% compared with mock-immunized controls, but failed to reduce chlamydial colonization of the lower genital tract. In contrast, mice immunized with rMOMP directly into the Peyer's patches to stimulate mucosal immunity shed fewer chlamydiae from the vagina than controls, but showed little reduction in oviduct damage. No consistent correlation was observed between antibody levels to rMOMP in immunized mice and reduced lower genital tract colonization. Immunization with rMOMP via the presacral space, a route previously shown to stimulate mucosal immunity in the genital tract, produced high levels of circulating anti-rMOMP IgG but only traces of anti-rMOMP IgA in vaginal secretions. There was no difference in the severity of salpingitis in these animals compared with mock-immunized controls. Immunization with rMOMP conferred no protection against infertility resulting from direct inoculation of chlamydiae into the oviducts.