Annulate lamellae represent a poorly understood class of cytomembranes (see references 14-18). The structural resemblance and proximity (in some cases) between the nuclear envelope and annulate lamellae have led to the concept that the annulate lamellae represent a product of the nuclear envelope although the methods propoundedly involved in the morphogenesis of annulate lamellae are indeed var...

widespread use of nanosilver can be led the contamination of aquatic environment and impact on living organisms such as fishes. we investigated histopathological changes in the gills tissue of caspian roach fingerlings after two weeks exposure to sublethal concentrations of nanosilver. following one and two weeks exposure, necrosis, shortening of secondary lamellae, edema, destruction of epithe...

Semi-isolated annulate lamellae were prepared from single newt oocytes (Triturus alpestris) by a modified Callan-Tomlin technique. Such preparations were examined with the electron microscope, and the negative staining appearance of the annulate lamellae is described. The annulate lamellae can be detected either adhering to the nuclear envelope or being detached from it. Sometimes they are obse...

Introduction: Planar deformation features (PDFs) in quartz are diagnostic impact evidence. Using light microscopy, it is often impossible to distinguish between PDFs and tectonic deformation lamellae. [1] showed that PDFs can be imaged using a cathodoluminescence (CL) detector in a scanning electron microscope (SEM) and that in SEM-CL images PDFs can be distinguished from tectonic microfracture...

The intracellular sites of glycogen degradation in the mid to late uterine chick embryo were determined by cytochemical localization of glucose-6-phosphatase at the ultrastructural level. Enzyme activity was found between the two membranes of the nuclear envelope, in the annulate lamellae and in specialized glycogen-containing membrane scrolls. Annulate lamellae and glycogen scrolls were most f...

We show that crucian carp (Carassius carassius) living in normoxic (aerated) water have gills that lack protruding lamellae, the primary site of O(2) uptake in fish. Such an unusual trait leads to a very small respiratory surface area. Histological examination showed that the lamellae (secondary lamellae) of these fish were embedded in a cell mass (denoted embedded lamellae). When the fish were...

Arapaima gigas, a fresh water fish found in the Amazon Basin, resist predation by piranhas through the strength and toughness of their scales, which act as natural dermal armour. Arapaima scales consist of a hard, mineralized outer shell surrounding a more ductile core. This core region is composed of aligned mineralized collagen fibrils arranged in distinct lamellae. Here we show how the Bouli...

The vitelline body in the mature oocyte of the spider Tegenaria parietina is composed of 4 different zones. 1. The central zone contains granular areas, vesicles, and a few lamellae. 2. The lamellar zone consists of numerous concentric lamellae. These sheets, 45 A in thickness, are stacked in groups. The fine structure and the regular arrangement recall those of myelin sheets, retinal rods, and...

Annulate lamellae have been observed in the myocardium of 18-day-old chick embryos maintained at the normal temperature of 100 degrees F and at 90 degrees F during the last week of incubation. An increased number of annulate lamellae was observed in heart muscle of embryos incubated at 90 degrees F. This is probably caused by a persistent production of these organelles, since annulate lamellae ...

Lamellae or cracks are distributed throughout tooth enamel in both deciduous and permanent dentitions. While earlier authors postulated that lamellae may be pathways of entry for caries, no evidence was adduced and the theory appears to have been discounted. The present study seeks to show that, at least in some cases, lamellae are permeable to dyes, may be associated with caries initiated in t...