Ethanol, Mallory Bodies, and the Microtubular System

Author(s):  
H. Denk
1982 ◽  
Vol 13 (1) ◽  
pp. 81-85 ◽  
Author(s):  
René P. Michel ◽  
James J. Limacher ◽  
R. John Kimoff

2010 ◽  
pp. 152-153
Author(s):  
Margit Pavelka ◽  
Jürgen Roth
Keyword(s):  

2002 ◽  
Vol 13 (10) ◽  
pp. 3441-3451 ◽  
Author(s):  
Ikuo Nakamichi ◽  
Shigetsugu Hatakeyama ◽  
Keiichi I. Nakayama

Mallory bodies (MBs) are cytoplasmic inclusions that contain keratin 8 (K8) and K18 and are present in hepatocytes of individuals with alcoholic liver disease, nonalcoholic steatohepatitis, or benign or malignant hepatocellular neoplasia. Mice fed long term with griseofulvin are an animal model of MB formation. However, the lack of a cellular model has impeded understanding of the molecular mechanism of this process. Culture of HepG2 cells with griseofulvin has now been shown to induce both the formation of intracellular aggregates containing K18 as well as an increase in the abundance of K18 mRNA. Overexpression of K18 in HepG2, HeLa, or COS-7 cells also induced the formation of intracellular aggregates that stained with antibodies to ubiquitin and with rhodamine B (characteristics of MBs formed in vivo), eventually leading to cell death. The MB-like aggregates were deposited around centrosomes and disrupted the microtubular array. Coexpression of K8 with K18 restored the normal fibrous pattern of keratin distribution and reduced the toxicity of K18. In contrast, an NH2-terminal deletion mutant of K8 promoted the formation of intracellular aggregates even in the absence of K18 overexpression. Deregulated expression of K18, or an imbalance between K8 and K18, may thus be an important determinant of MB formation, which compromises the function of centrosomes and the microtubule network and leads to cell death.


PEDIATRICS ◽  
1961 ◽  
Vol 28 (1) ◽  
pp. 107-127
Author(s):  
Hans F. Smetana ◽  
G. Gordon Hadley ◽  
Satyavati M. Sirsat

Infantile cirrhosis is a very serious, often fatal, liver disease, largely limited to India or to descendants of Indians residing in the region of southern Asia. It occurs most frequently in children between 1 and 3 years of age and affects both sexes with about equal frequency; familial instances are not uncommon. The clinical picture is characterized by irritability, gastrointestinal upsets, jaundice, anemia and retarded development. In a number of cases there is a history of fever in some stages of the disease. Children with advanced cases develop hepatosplenomegaly, a sharp and hard anterior edge of the liver, and evidence of effects of progressive portal hypertension. The basic pathogenetic process leading to this liver disease is characterized histopathologically by evidence of profound injury to individual liver cells, resulting in severe degenerative changes and dissociation of the cytoplasmic contents; marked swelling; partial hyalinization of the cytoplasm (Mallory bodies); "bird's eye" nuclei, indicating difficulty in protein synthesis; and satellitosis about Mallory bodies—probably an attempt to remove the necrobiotic liver cells. In certain cases there is massive progressive degeneration and necrosis of liver cells, causing hepatic insufficiency without formation of regenerative pseudolobules and without development of portal hypertension. This course is interpreted as the result of a severe, diffuse injury of hepatic cells, which are unable to regenerate. This condition can perhaps be compared with the experimental massive acute necrosis due to thiamin deficiency in animals and with the diffuse hepatic necrosis seen in "florid cirrhosis" in human beings. In the majority of cases, however, there is development of a portal type of cirrhosis with formation of unilobular, regenerative islets, followed by rising portal hypertension with its usual consequences; not infrequently the regenerated elements are again destroyed by the persisting injurious process. Evidence of a causal relationship between viral hepatitis and infantile cirrhosis cannot be considered established; neither epidemiologic features nor histopathologic findings are thought to be compatible with the effects of viral hepatitis. The familial occurrence appears to be related to environmental factors rather than to a common source of infection from a silent carrier or to heredity. The nonspecific inflammatory infiltrates (satellites) accompanying this process are interpreted as a scavenger reaction secondary to the injury, degeneration, and necrosis of liver cells. Regeneration of liver cells can take place only if there are viable hepatic elements. The resulting cirrhosis of the liver is characterized by regenerated pseudolobules developing from such surviving liver cells, embedded in and surrounded by the collapsed pre-existent parenchymal stromal elements, including the surviving tissues from the portal canals. The role of the supporting tissue is considered to be entirely passive and incidental to the primary process of cell destruction. The necrobiotic changes of individual liver cells, with formation of Mallory bodies, the progressive destruction of the hepatic parenchyma, and the development of a portal type of cirrhosis are quite indicative of a nutritional cause, despite the absence of fatty metamorphosis. The histologic changes are unlike those described in persistent viral hepatitis or in the developing stages of posthepatitic (coarse, nodular) cirrhosis. The obliterative vascular changes of advanced infantile cirrhosis are interpreted as secondary phenomena accompanying the complete reorganization of the liver parenchyma. Electron microscopic studies of liver tissue from cases of histologically established infantile cirrhosis demonstrate profound disorganization of ultramicroscopic structures of liver cells, with reduction in number, distortion and partial obliteration of mitochondria, secretory granules and microsomes; deformity and distention of the channels of the intracytoplasmic reticulum; and alteration of nuclei and nuclear components. The "alcoholic hyalin" of the Mallory body appears to be the result of condensation and fusion of damaged, distorted and obliterated mitochondria.


1969 ◽  
Vol 5 (2) ◽  
pp. 479-493 ◽  
Author(s):  
J. D. DODGE ◽  
R. M. CRAWFORD

The eyespot of the marine dinoflagellate Glenodinium foliaceum is a flattened orange structure, more or less trapezoid in shape with an anterior hook-like projection. It is situated on the ventral side of the organism in the vicinity of the flagellar bases at the anterior end of the sulcus. In the electron microscope the eyespot is seen to contain two layers of osmiophilic granules 80-200 nm in diameter which usually show hexagonal close-packing. The eyespot is surrounded by a triple-membraned envelope and is not connected to any other organelle. Adjacent to the eyespot is a distinctive organelle termed the ‘lamellar body’. This consists of a stack of up to 50 flattened vesicles or disks, each 16 nm thick and about 750 nm wide, the whole being orientated in an antero-posterior direction. The lamellae are continuous, at the ends of the stack, with rough endoplasmic reticulum and are joined together by occasional bridges at their edges. The bases of the two flagella lie just ventral to the lamellar body and from them roots arise which pass by the eyespot and join the subthecal microtubular system. The eyespot of Glenodinium is unique both in structure and the presence of the associated lamellar body. It differs from eyespots which have been described from other algal groups and also from the more complex ocellus found in certain dinoflagellates belonging to the order Warnowiaceae. The method by which the eyespot functions is discussed and it is suggested that unidirectional stimuli could be perceived by shading of the lamellar body.


2001 ◽  
Vol 114 (13) ◽  
pp. 2427-2435 ◽  
Author(s):  
Bunshiro Goto ◽  
Koei Okazaki ◽  
Osami Niwa

Chromosomes are not packed randomly in the nucleus. The Rabl orientation is an example of the non-random arrangement of chromosomes, centromeres are grouped in a limited area near the nuclear periphery and telomeres are located apart from centromeres. This orientation is established during mitosis and maintained through subsequent interphase in a range of species. We report that a Rabl-like configuration can be formed de novo without a preceding mitosis during the transition from the sexual phase to the vegetative phase of the life cycle in fission yeast. In this process, each of the dispersed centromeres is often associated with a novel Sad1-containing body that is contacting a cytoplasmic microtubule laterally (Sad1 is a component of the spindle pole body (SPB)). The Sad1-containing body was colocalized with other known SPB components, Kms1 and Spo15 but not with Cut12, indicating that it represents a novel SPB-related complex. The existence of the triplex structure (centromere-microtubule-Sad1 body) suggests that the clustering of centromeres is controlled by a cytoplasmic microtubular system. Accordingly, when microtubules are destabilized, clustering is markedly reduced.


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