Immunohistochemical localization of glycosaminoglycans and proteoglycans in predentin and dentin of rat incisors.

We examined immunocytochemically the type and distribution of glycosaminoglycans and proteoglycans (PG) in predentin and dentin demineralized with EDTA after aldehyde fixation of rat incisors using (a) four monoclonal antibodies (1-B-5,9-A-2,3-B-3, and 5-D-4) which recognize epitopes in unsulfated chondroitin (C0-S), chondroitin 4-sulfate (C4-S), chondroitin 6-sulfate (C6-S), and keratan sulfate (KS) associated with the PG, and (b) monoclonal (5-D-5) and polyclonal antibodies specific for the core protein of large and small dermatan sulfate (DS) PG. Light microscope immunoperoxidase staining after pre-treatment of tissue sections with chondroitinase ABC localized the majority of stainable PG (C4-S, KS, DSPG, C0-S, and C6-S) in predentin and, to a lesser extent (C4-S and small DSPG), in the dentin matrix. The former site demonstrated relatively homogeneous PG distribution, whereas the latter site revealed that strong staining of C4-S and small DSPG was confined mostly to dentinal tubules surrounding odontoblastic processes, with only weak staining in the rest of the dentin matrix. These results indicate that there is not only a definite difference between PG of predentin and dentin but also a selective decrease in the concentration or alteration of these macromolecules during dentinogenesis and mineralization.

Differential distribution and ultrastructural staining of oxytalan and elastic fibers in the periodontal ligament of Alligator mississippiensis.

We have investigated ultrastructural cytochemical properties of elastic elements in Alligator periodontal ligaments decalcified with EDTA and stained with 1) the tannic acid-uranyl acetate (TA-UA) method for elastin in combination with elastase digestion; 2) the high iron diamine-thiocarbohydrazide-silver proteinate (HID-TCH-SP) method with prior treatment of specimens with either monopersulphate or cupric-sulphite reagent for the localization of disulphide- and/or sulphydryl-containing material (i.e., oxytalan fibers); and 3) HID-TCH-SP alone for sulphated complex carbohydrates. Many microfibrils accumulated to form either large or small bundles. Large bundles having a diameter of 2.50 +/- 1.10 microns (mean +/- SD; n = 50) each showed an apico-occlusal distribution, although small bundles measuring 0.63 +/- 0.13 microns (mean +/- SD; n = 50) in diameter each were exclusively localized in interstitial areas rich in vessels and nerves. The former bundles always lacked TA-UA reactivity and represented oxytalan fibers; the latter bundles frequently contained TA-UA-reactive elastase digestible components and were similar in appearance to immature elastic fibers or elaunin fibers. HID-TCH-SP after oxidation strongly stained both the oxytalan and elastic fiber microfibrils but stained the amorphous elastin very weakly or not all. In nonoxidized specimens, there was no definite HID-TCH-SP staining of microfibrils and the amorphous elastin, although adjacent matrix proteoglycans stained consistently. These results indicate that although there is a marked difference in the distribution and size of oxytalan and elastic fibers in Alligator periodontal ligaments, their associated microfibrils lack stainable sulphate groups but are enriched with disulphide and/or sulphydryl groups, as has been described in mammals.

Qualitative and quantitative changes in thoracic duct lymph during canine experimental shock.

Changes of the body fluid exchange and of the composition of metabolites in the hepatosplanchnic area in canine hemorrhagic and endotoxin or septic shock models were studied by investigating the qualitative and quantitative changes in thoracic duct lymph draining from abdominal organs. In the present study, it might be summarized that the changes in the flow rate and composition of thoracic duct lymph were put forward to much more directly and apparently indicate the degree of hepatosplanchnic cellular impairment in canine experimental shock than in the circulating blood.