Vascular changes in the cheek pouch of the golden hamster during infection with Trichinella spiralis larvae

Abstract

Iiicreasecl vascularity in tlie immediate vicinity of muscle fibers infected with Trichivzelln spiralis larvae has been observed in post-mortem studies. Pagensteclier (1865) observed the extraordinary developnient of the mesh of blood vessels around infected muscle fibers before the beginning of encapsul'ation and published a drawing of such a vascular netmorlc. Ogielslii ('49), after a post-mortem injection of China ink in mice, sliomed a ''netting of capillaries" around the site of each larva in the muscle fibers. He observed no vascular networks through the 22nd day after infection, but a t 33 days iietmorks of vessels were present around the coiled l a i~a e . After 46 days, the muscle striations began to disappear, and the site of each larva bccanie distinct and sharply limited from the surrounding area. He suggested that one of the reasons why the larvae settle mostly in certain places, for example, the diaphragm, inay be that these muscles have a large number of richly ramified vessels.Because of the hemostasis which occurs after death, it is virtually impossible to distinguish vessels of capillary size in freshly pressed muscle mitliout previous injection of colored 'This iiivestigatioii n n s supported (in part)

Effect of X-irradiation and Beta Emanation on Circulation in the Hamster Cheek Pouch

“…An initial leukocytosis following x-irradiation was reported previously for the rabbit and the chicken by Prosser. 8 In the hamster, the latent period was essentially the same (2 to 3 hours) and the duration similar (12 horn's) for all doses. This response of the leukocytes was absent in control hamsters observed for comparable periods of time.…”

Trichinella spiralis: Vascular Endothelial Growth Factor Is Up-Regulated within the Nurse Cell during the Early Phase of Its Formation

“…In addition, some VEGF mRNA was detected in the surrounding inflammatory cells at days 15 and 17 (data not shown). New vessels begin to form around the nurse cell at about day 12 after infection (Humes and Akers, 1952) and are probably stimulated to do so solely by the initial synthesis of VEGF emanating from the developing nurse cell. However, as the parasite and nurse cell further increase their biomass, hypoxia increases and, at the same time, demand for nutrients increases.…”

“…The nurse cell is fully developed by day 20 after the newborn larva enters the myocyte (Despommier, 1983). Cellular events associated with nurse cell development include (1) complete remodeling of the cytoplasmic matrix, replacing all contractile filaments with whorls of smooth membranes and altered mitochondria (vacuolated inner matrices; Despommier, 1975); (2) all host cell nuclei divide once and each nucleus then replicates its DNA again, resulting in 4N nuclei (Jasmer, 1993); (3) 4N nurse cell nuclei enlarge and remain so throughout the infection (Despommier, 1975;Despommier et al, 1991) and all nurse cell nuclei are transcriptionally active; and (4) a collagen capsule (Ritterson, 1966) Beginning on about day 12, the circulatory rete develops (Pagenstecher, 1865; Humes and Akers, 1952;Wright et al, 1989;Baruch and Despommier, 1991). The biological significance of the rete for the nurse cell is apparent.…”

Coordinated Control of Immunity to Muscle StageTrichinella spiralisby IL-10, Regulatory T Cells, and TGF-β

“…The diaphragm, tongue, and masseter muscles are all preferred sites of infection in mice (2). Each NBL invades a single, terminally differentiated muscle cell (myotube) and, over a period of 20 days, both the parasite and the host cell undergo a process of coordinated growth and development, marked by dramatic host cell remodeling (3)(4)(5)(6). If larvae survive this developmental period, they establish a chronic infection that is essential for transmission.…”