Oval cells

It was an adaptation of the Castner cell to sodium chloride for fused caustic electrolysis. A mixture of sodium chloride and other chlorides, molten at 620°C, was electroly2ed ia rectangular or oval cells heated only by the current. Several cells have been patented for the electrolysis of fused salt ia cells with molten lead cathodes (65). However, it is difficult to separate the lead from the sodium (see Electrochemical processing). 

The third of the cellular elements within the blood are the platelets (thrombocytes). Platelets are actually small, round or oval cell fragments. They are about 2 to 4 pm in diameter and have no nuclei. Platelets are formed in the red bone marrow as pinched-off portions of the very large megakaryocytes. Each megakaryocyte, which is confined to the bone marrow, can produce... 

Nakamura, Y., Trosko, J. E., Chang, C. C., and Upham, B. L. (2004). Psyllium extracts decreased neoplastic phenotypes induced by the Ha-Ras oncogene transferred into a rat liver oval cell line. Cancer Lett. 203,13-24. 

Petersen BE, Bowen WC, Patrene KD, Mars WM, Sullivan AK, Murase N et al (1999). Bone marrow as a potential source of hepatic oval cells. Science 284 1168-1170. 

Acetous fermentation [souring) is caused by Mycoderma aceti, which consists of oval cells with a marked constriction in the middle, resemblance to the figure 8 being thus produced. The cells are considerably smaller (about 10 times) than those of M. vini. In some cases several individuals are joined in a chain. 

Mazurek, S., Eigenbrodt, E., Failing, K., Steinberg, P. (1999). Alterations in the glycolytic and glutaminolytic pathways after malignant transformation of rat liver oval cells./. CeU Physiol. 181,136-146. 

In addition to hepatic parenchymal cells which are hepatocytes, hepatocyte stem cells, termed oval cells, are reported to be located in the canals of Hering where bile canaliculi from the hepatic cords converge on bile ductules of the portal triad. It is postulated that new hepatocytes travel down hepatic cords to replace the aging and damaged zone 3 hepatocytes. 

Stem cells are progenitor cells which are not yet specifically formed. They can multiply almost infinitely and form nearly all 210 tissue types in the human being. Depending on their derivation, they are defined as follows .) embryonal (= taken from the inner cell mass of the blastocysts), (2.) foetal (= isolated from 5-9 week-old abortive foetuses, and (5.) adult (= taken from the tissue of adults or children by means of biopsy or from the umbilical cord of newborns. Adult stem cells are limited in number and life span they do, however, have a broader development potential than so far assumed. They have also been found in the liver. The transformation of stem cells from the bone marrow into hepatocytes has been carried out successfully. Liver stem cells (7-15 gm) can develop both primary cell types of the liver, (7.) mature hepatocytes and (2.) biliary epithelial cells. These stem cells are deemed to be genuine liver stem cells, and not merely derived from the activation of immature oval cells in the liver. (54,59, 60, 81) (s. fig. 2.20)... 

Liver Foci of cellular alteration Hepatocellular hyperplasia Oval cell proliferation Cholangiofibrosis... 

Pityrosporum (3) none (these yeasts are difficult to cultivate) isolated from mammals require lipids spherical or oval cells with monopolar budding not filamentous 61... 

Trigonopsis (1) none few sugars three-cornered or oval cells not filamentous 79... 

The blood supply to each acinus consists of three zones (Figure 47-3). Zone 1 is the area immediately adjacent to the portal tract and is enriched with lysosomes and mitochondria. The periphery of the acinus, zone 3, is enriched with endoplasmic reticulum, is very active meta-bolically, and has relatively low oxygen tension. Tills area is most susceptible to injury, although zone 1 appears to be involved with protecting the liver from external injury and providing a base for hepatic regeneration (by means of the oval cells of periportal bile ductules, the apparent hepatic stem cells). 

Desmoplastic small round cell tumor Young adults, often adolescent boys. Abdomen and pelvis, peritoneal implants. Round/oval cells in desmoplastic stroma in classic cases, other cases with variable morphology Vimentin+, cytokeratin+, EMA+, desmin+, WT1 + RT-PCR for EWS-WT1... 

Ruck P, Xiao JC, Pietsch T, et al. Hepatic stem-like cells in hepatoblastoma expression of cytokeratin 7, albumin and oval cell associated antigens detected by OV-1 and OV-6. Histopathology. 1997 31 324-329. 

Fausto N, Campbell J S (2003). The role of hepatocytes and oval cells in liver regeneration and repopulation. Mech. Dev. 120 117-130. 

Shimano K, Satake M, Okaya A, et al. (2003). Hepatic oval cells have the side population phenotype defined by expression of ATP-binding cassette transporter ABCG2/ BCRPl. Am. J. Pathol. 163 3-9. 

Paku S, Schnur J, Nagy P, et al. (2001). Origin and structural evolution of the early proliferating oval cells in rat liver. Am. J. Pathol. 158 1313-1323. 

Petersen B E, Goff J P, Greenberger J S, et al. (1998). Hepatic oval cells express the hematopoietic stem cell marker Thy-1 in the rat. Hepatol. 27 433-445. 

Binding of (3-lactam antibiotics to PBP-1A and PBP-1 B (transpeptidase) of Escherichia coii leads to cell lysis to PBP-2 (transpeptidase) leads to oval cells deficient in rigidity and to inhibition of cell division to PBP-3 (transpeptidase) leads to abnormally long, filamentous shapes by failure to produce a septum and to PBP-4 through PBP-6 (carboxypeptidases) leads to no lethal effects. Approximately 8% of a dose of benzylpenicillin binds to PCP-1, 0.7% to PCP-2, 2% to PBP-3, 4% to PBP-4, 65% to PBP-5, and 21% to PBP-6. Thus, the majority of the penicillin dose bonds to PBPs for which the function remains obscure. Binding to PBP-1 is lethal. Other (3-lactam antibiotics display different binding patterns. Amoxicillin and the cephalosporins bind more avidly to PBP-1, methicillin and cefotaxime to PBP-2, and mezlocillin and cefuroxime to PBP-3. All these drugs are lethal to susceptible bacteria. 

Surgical models also exit for evaluation of hepatic fibrosis. The most common method employed is ligation of the common bile duct in rats or mice. The subsequent response involves not only fibrosis but also proliferation of biliary epithelial cells, oval cells, portal inflammation, and, of course, cholestasis. With time, there is progression to biliary cirrhosis and hepatic failure. Relatively high mortality... 

The presence of adult multipotent stem cells has been established in many tissue types in humans including haematopoietic stem cells (HSCs), pancreatic progenitor cells, retinal progenitor cells, neural stem cells (NSCs), epidermal stem cells, cardiomyocytes, oval cells (liver) and satellite cells (muscle), although their regenerative capacity and even their existence have been controversial in many cases (Figure 4.3). In most cases in humans these tissue... 

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