A vacuole is a membrane-bound subcellular structure involved in intracellular digestion. Instead of the large "vacuolar" organelles that are found in plants and fungi, animal cells possess lysosomes that are smaller in size and are enriched with hydrolytic enzymes similar to those found in the vacuoles. Large vacuolar structures are often observed in highly differentiated mammalian tissues such...

Light microscopy was used to study the structure and function of vacuoles in living protoplasts of barley (Hordeum vulgare cv Himalaya) aleurone. Light microscopy showed that aleurone protoplasts contain two distinct types of vacuole: the protein storage vacuole and a lysosome-like organelle, which we have called the secondary vacuole. Fluorescence microscopy using pH-sensitive fluorescent prob...

The vacuole is the largest compartment of a mature plant cell and may occupy up to 95% of the total cell volume. In such mature cells, the cytosol is visible only as a thin layer, which is separated from the cell wall by the plasma membrane, and from the vacuolar sap (cell sap) by the vacuolar membrane (tonoplast). The constituents of the cell sap are mainly inorganic salts and water. The vacuo...

Spongiform change is a hallmark of transmissible spongiform encephalopathies (TSEs) in prion diseases. They are defined as small round or oval empty spaces in the neuropil. When confluent, they merge to form "morula-like" structures. Their neuroanatomical distribution and grading within each of defined neuroanatomical areas underlie the lesion profile method used to discriminate strains in rode...

In the present study, various developmental stages of Liza aurata oocyte, especially IV and V stages have been described. On the basis of histological investigations, oocyte development in L. aurata comprises immature (I), the early maturing (II), the late maturing (III), mature (IV), ripe (V), and spent (VI) stages. In the stages I and II, nucleus occupied large volume of oocyte. Vacuolization...

The obligate intracellular bacterium Coxiella burnetii, the agent of Q fever in humans and of coxiellosis in other animals, survives and replicates within large, acidified, phagolysosome-like vacuoles known to fuse homo- and heterotypically with other vesicles. To further characterize these vacuoles, HeLa cells were infected with C. burnetii phase II; 48 h later, bacteria-containing vacuoles we...

Peripheral nerves undergoing degeneration are favorable material for studying the types, origins, and functions of lysosomes. The following lysosomes are described: (a) Autophagic vacuoles in altered Schwann cells. Within these vacuoles the myelin and much of the axoplasm which it encloses in the normal nerve are degraded (Wallerian degeneration). The delimiting membranes of the vacuoles appare...

The involvement of the visual system is well recognised in TSEs. The present review summarises the ultrastructural changes in the optic nerves in experimental infections of laboratory rodents with the agents of two human TSEs (CJD and GSS) and with two isolates of the scrapie agent. Vacuoles of myelinated fibres were found within myelin sheaths and themselves contained secondary vacuoles (vacuo...

The intracellular distributions of the cation-independent mannose 6-phosphate receptor (MPR) and a 120-kD lysosomal membrane glycoprotein (lgp120) were studied in rat hepatoma cells. Using quantitative immunogold cytochemistry we found 10% of the cell's MPR located at the cell surface. In contrast, lgp120 was not detectable at the plasma membrane. Intracellularly, MPR mainly occurred in the tra...

OBJECTIVE The presence of sperm-head vacuoles has been suspected to be deleterious to the outcomes of assisted reproductive technology (ART). It is difficult to accurately distinguish morphologically abnormal sperm with vacuoles under a light microscope. This study was performed to analyze the result of the observation of sperm-head vacuoles using Papanicolaou staining under a light microscope ...