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Ablation of rat myenteric plexus with benzalkonium chloride has provided a model of intestinal aganglionosis, but the degenerative
responses are not well understood. We examined the effects of this detergent on neurons and glia, including expression of
c-Myc, c-Jun, JunB, and c-Fos, and on immunocytes in the guinea-pig ileum. Benzalkonium chloride (0.1%) or saline was applied
to the serosal surface of distal ileum. Tissues were analyzed 2, 3, or 7 days later and compared with cyclosporine-treated
and untreated animals. More than 90% of myenteric neurons were destroyed in ileal segments 3–7 days after benzalkonium-chloride
treatment. Glia withdrew processes from around neurons after 2 days and were mostly gone after 3 days. Neuronal c-Myc began
to disappear while c-Fos, c-Jun, and JunB were evident in some neuronal nuclei after 2 or 3 days. After 3 days, widespread
apoptosis was evident in the myenteric plexus. Populations of T cells, B cells, and macrophage-like cells in untreated and
saline-treated myenteric plexuses were substantially increased 3 and 7 days after benzalkonium-chloride treatment. Cyclosporine
delayed significant neuronal loss. We conclude that a variety of degenerative mechanisms may be active in this model, including
an immune response which may actively contribute to tissue destruction.
Received: 13 September 1996 / Accepted: 20 January 1997 相似文献
84.
85.
M. Masuyama 《Biometrical journal. Biometrische Zeitschrift》1991,33(6):725-733
A mathematical model of the linearized growth curve and its physiological interpretation by the introduction of proper age, which is proportional to the chronological age, are presented here. In the second phase, but not in the first phase, this constant of proportionality is highly correlated with the age at menarche. 相似文献
86.
The concept of the blood-aqueous barrier is largely based on the use of horseradish peroxidase (HRP). The present investigation
was designed to check its reliability as a macromolecular tracer, especially with regard to the transport of plasma proteins.
Rabbits were killed 5 min to 24 h after being intravenously injected with HRP. The tracer diffused rapidly, reaching the aqueous
humor of the eye in 3 min or less and was detected at high concentration in the narrow space between the outer epithelial
layer of the ciliary epithelium and the wall of the pervious capillaries in the stroma of the processes. HRP appeared to migrate
from the blood to the posterior chamber, permeating the tight junctions, viz., the anatomical basis of the blood-aqueous barrier.
It was detected at higher concentration at the anterior surface of the iris, at short time intervals; this was interpreted
as penetration of the tracer from the aqueous humor of the anterior chamber. The choroid was also labeled in continuation
with the reaction in the stroma of the pars plana of the ciliary body which, in turn, sometimes reached the iris root. Therefore,
the pervious blood vessels of the choroid could be a source of macromolecules for the iris root. HRP also induced the formation
of lysosomes in the ciliary epithelium. This can hardly be accepted as the way in which plasma proteins are physiologically
transported to the aqueous humor. However, the pathway of HRP migration over short time intervals seems to be in agreement
with previous research indicating that the entrance of serum albumin into the posterior chamber is the first step of its incorporation
into the aqueous humor.
Received: 7 June 1996 / Accepted: 15 January 1997 相似文献
87.
88.
N. Fujii N. Tomaru K. Okuyama T. Koike T. Mikami K. Ueda 《Plant Systematics and Evolution》2002,232(1-2):21-33
CpDNA variation in Japanese beech, Fagus crenata (Fagaceae), was studied in 45 populations distributed throughout the species' range. Two cpDNA regions were sequenced: the
non-coding region between the trnL (UAA) 5′exon and trnF (GAA), and the trnK region (including matK). Thirteen distinct cpDNA haplotypes were recognized and each haplotype was found to be geographically structured. Two major
clades (I and II+III) were revealed in phylogenetic analyses among the haplotypes using F. sylvatica as an outgroup. The haplotypes of Clade I were distributed mainly along the Japan Sea side of the Japanese Archipelago, while
those of Clade II+III occurred chiefly along the Pacific Ocean side. Consequently, the distribution of the two major cpDNA
clades suggests that there were two migration routes in the history of F. crenata; one along the Japan Sea and the other along the Pacific Ocean side of the Japanese Islands.
Received March 19, 2001 Accepted November 22, 2001 相似文献
89.
90.