Histological Observations on the Wing of the Grey-Headed Flying-Fox (Pteropus-Poliocephalus) (Chiroptera, Pteropodidae)

1994 ◽  
Vol 42 (2) ◽  
pp. 215 ◽  
Author(s):  
GV Crowley ◽  
LS Hall
Keyword(s):  
Membrane Surface ◽  
Light And Electron Microscopy ◽  
Basal Layer ◽  
Epidermal Keratinocytes ◽  
Electron Microscope Level ◽  
Wing Membrane ◽  
Pteropus Poliocephalus ◽  
Bat Wing ◽  
Dorsal Epidermis ◽  
Flying Fox

The histological features of the wing membrane of Pteropus poliocephalus are described at both the light and electron microscope level. A method is described for the processing of bat wing tissue for both light and electron microscopy. The flight membrane of P. poliocephalus had a dorsal and ventral layer of epidermis with a common dermis in between. There was no hypodermis and all layers were greatly reduced in comparison with the skin of other mammals. The epidermis consisted of three layers of active keratinocytes, covered by 7-10 layers of cornified cells. Melanocytes were generally confined to the basal layer and were more numerous in the dorsal epidermis. Prominent droplets of a lipid-like substance were found in the epidermal keratinocytes and these coalesced towards the superficial layers. It is postulated that the substance contained in these droplets is a waterproofing agent. The dermis consisted mainly of collagen bundles with a network of elastin bands. An array of hair-dome complexes were found on the wing membrane surface. These receptors are similar to those described in several microchiropterans, where it is thought they provide information on airflow patterns over the wing.

scholarly journals Diversified Stimuli-Induced Inflammatory Pathways Cause Skin Pigmentation

2021 ◽  
Vol 22 (8) ◽  
pp. 3970
Author(s):  
Md Razib Hossain ◽  
Tuba M. Ansary ◽  
Mayumi Komine ◽  
Mamitaro Ohtsuki
Keyword(s):  
Inflammatory Responses ◽  
Light Exposure ◽  
Skin Pigmentation ◽  
Basal Layer ◽  
Decisive Role ◽  
Skin Inflammation ◽  
Dermal Fibroblasts ◽  
Epidermal Keratinocytes ◽  
Hair Color ◽  
Microbial Infection

The production of melanin pigments by melanocytes and their quantity, quality, and distribution play a decisive role in determining human skin, eye, and hair color, and protect the skin from adverse effects of ultraviolet radiation (UVR) and oxidative stress from various environmental pollutants. Melanocytes reside in the basal layer of the interfollicular epidermis and are compensated by melanocyte stem cells in the follicular bulge area. Various stimuli such as eczema, microbial infection, ultraviolet light exposure, mechanical injury, and aging provoke skin inflammation. These acute or chronic inflammatory responses cause inflammatory cytokine production from epidermal keratinocytes as well as dermal fibroblasts and other cells, which in turn stimulate melanocytes, often resulting in skin pigmentation. It is confirmed by some recent studies that several interleukins (ILs) and other inflammatory mediators modulate the proliferation and differentiation of human epidermal melanocytes and also promote or inhibit expression of melanogenesis-related gene expression directly or indirectly, thereby participating in regulation of skin pigmentation. Understanding of mechanisms of skin pigmentation due to inflammation helps to elucidate the relationship between inflammation and skin pigmentation regulation and can guide development of new therapeutic pathways for treating pigmented dermatosis. This review covers the mechanistic aspects of skin pigmentation caused by inflammation.

scholarly journals Developmental, cellular, and biochemical basis of transparency in clearwing butterflies

2021 ◽  
Author(s):  
Aaron F. Pomerantz ◽  
Radwanul H. Siddique ◽  
Elizabeth I. Cash ◽  
Yuriko Kishi ◽  
Charline Pinna ◽  
...  
Keyword(s):  
Lower Layer ◽  
Membrane Surface ◽  
Developmental Time ◽  
Scale Growth ◽  
Wing Membrane ◽  
Biochemical Basis ◽  
Cytoskeletal Organization ◽  
Surface Nanostructures ◽  
Insight Into ◽  
Confocal And Electron Microscopy

The wings of butterflies and moths (Lepidoptera) are typically covered with thousands of flat, overlapping scales that endow the wings with colorful patterns. Yet, numerous species of Lepidoptera have evolved highly transparent wings, which often possess scales of altered morphology and reduced size, and the presence of membrane surface nanostructures that dramatically reduce reflection. Optical properties and anti-reflective nanostructures have been characterized for several ‘clearwing’ Lepidoptera, but the developmental processes underlying wing transparency are unknown. Here, we apply confocal and electron microscopy to create a developmental time-series in the glasswing butterfly, Greta oto, comparing transparent and non-transparent wing regions. We find that during early wing development, scale precursor cell density is reduced in transparent regions, and cytoskeletal organization during scale growth differs between thin, bristle-like scale morphologies within transparent regions and flat, round scale morphologies within opaque regions. Next, we show that nanostructures on the wing membrane surface are composed of two layers: a lower layer of regularly arranged nipple-like nanostructures, and an upper layer of irregularly arranged wax-based nanopillars composed predominantly of long-chain n-alkanes. By chemically removing wax-based nanopillars, along with optical spectroscopy and analytical simulations, we demonstrate their role in generating anti-reflective properties. These findings provide insight into morphogenesis and composition of naturally organized micro- and nanostructures and may provide bioinspiration for new anti-reflective materials.

The ultrastructure of the cardiac Purkinje strand in the dog: a morphometric analysis

1983 ◽  
Vol 217 (1207) ◽  
pp. 191-213 ◽  
Keyword(s):  
Electron Microscopy ◽  
Electrical Properties ◽  
Connective Tissue ◽  
Surface Area ◽  
Series Resistance ◽  
Membrane Surface ◽  
Light And Electron Microscopy ◽  
Total Surface Area ◽  
Membrane Surface Area ◽  
Extracellular Ions

Purkinje strands from both ventricles of adult mongrel dogs were excised, and electrical properties were studied by the voltage-clamp technique. The strands were then examined with light and electron microscopy and structural properties were analysed by morphometric techniques. The canine Purkinje strand contains (by volume) about 28% myocyte and 55% dense outer connective tissue. The remainder of the volume is taken up by the inner shell of loosely packed connective tissue within 10 μm of a myocyte membrane. These volume fractions vary considerably from one strand to another. Clefts less than 10 μm wide occupy 18% of the myocyte volume and clefts less than 1 μm wide occupy 1%. The membrane surface area of the myocytes can be divided into three categories by reference to the size of the adjacent cleft. About 47.8% of the membrane surface area faces clefts wider than 1 μm, another 22.2% faces clefts between 0.1 and 1 μm wide, and the final 30% faces clefts less than 0.1 μm wide. The surface area facing the narrowest clefts (less than 0.1 μm wide) is divided between nexuses 3%, desmosomes 10%, and unspecialized membrane 17% (each figure is expressed as a percentage of the total surface area of myocyte membrane). The canine Purkinje strand has a more favourable anatomy than the sheep Purkinje strand for most physiological experiments. We expect that the complicating effects of series resistance and change in the concentration of extracellular ions will be much smaller than in sheep strands, but still not negligible.

Molecular investigation of Hepatocystis parasites in the Australian flying fox Pteropus poliocephalus across its distribution range

2019 ◽  
Vol 75 ◽  
pp. 103978
Author(s):  
Juliane Schaer ◽  
Wayne S.J. Boardman ◽  
Adam McKeown ◽  
David A. Westcott ◽  
Kai Matuschewski ◽  
...  
Keyword(s):  
Distribution Range ◽  
Pteropus Poliocephalus ◽  
Molecular Investigation ◽  
Flying Fox

scholarly journals Psoriasiform Drug Eruption Caused by Abatacept: Immunohistochemical Investigation of STAT Signaling

2015 ◽  
Vol 7 (2) ◽  
pp. 166-170 ◽  
Author(s):  
Kayo Tanita ◽  
Taku Fujimura ◽  
Aya Kakizaki ◽  
Sadanori Furudate ◽  
Yoshiyuki Kusakari ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Adverse Effects ◽  
Immunohistochemical Staining ◽  
Drug Eruption ◽  
Psoriasis Vulgaris ◽  
Basal Layer ◽  
Epidermal Keratinocytes ◽  
Immunological Mechanisms ◽  
Stratum Spinosum ◽  
Old Japanese

Abatacept is a biological immune modifier that is used for the treatment of rheumatoid arthritis. Although psoriasiform drug eruption is reported as one of the cutaneous adverse effects of abatacept, the precise mechanisms are not fully understood. In this report, we describe a 65-year-old Japanese man with psoriasiform drug eruption caused by abatacept. Interestingly, immunohistochemical staining revealed that the epidermal keratinocytes in the basal layer and lower layers of the stratum spinosum were positive for pSTAT3, partially positive for pSTAT1 and negative for pSTAT6, which is similar to conventional psoriasis vulgaris. Our present study suggests that psoriasiform drug eruption caused by abatacept might develop by similar immunological mechanisms as those of psoriasis vulgaris.

Daytime behaviour of the grey-headed flying fox Pteropus poliocephalus Temminck (Pteropodidae: Megachiroptera) at an autumn/winter roost.

2006 ◽  
Vol 28 (1) ◽  
pp. 7 ◽  
Author(s):  
K. A. Connell ◽  
U. Munro ◽  
F. R. Torpy
Keyword(s):  
Management Strategies ◽  
Reproductive Period ◽  
Urban Environments ◽  
Flying Foxes ◽  
Fruit Bat ◽  
Open Forest ◽  
Pteropus Poliocephalus ◽  
Baseline Information ◽  
Daytime Behaviour ◽  
Flying Fox

The grey-headed flying fox (Pteropus poliocephalus Temminck) is a threatened large fruit bat endemic to Australia. It roosts in large colonies in rainforest patches, mangroves, open forest, riparian woodland and, as native habitat is reduced, increasingly in vegetation within urban environments. The general biology, ecology and behaviour of this bat remain largely unknown, which makes it difficult to effectively monitor, protect and manage this species. The current study provides baseline information on the daytime behaviour of P. poliocephalus in an autumn/winter roost in urban Sydney, Australia, between April and August 2003. The most common daytime behaviours expressed by the flying foxes were sleeping (most common), grooming, mating/courtship, and wing spreading (least common). Behaviours differed significantly between times of day and seasons (autumn and winter). Active behaviours (i.e., grooming, mating/courtship, wing spreading) occurred mainly in the morning, while sleeping predominated in the afternoon. Mating/courtship and wing spreading were significantly higher in April (reproductive period) than in winter (non-reproductive period). Grooming was the only behaviour that showed no significant variation between sample periods. These results provide important baseline data for future comparative studies on the behaviours of flying foxes from urban and ?natural? camps, and the development of management strategies for this species.

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