Loss Of Cuticle Research Articles

Architecture of vibrissae in eight rodent species of Ctenohystrica (Rodentia): A comparative SEM study

Our study was conducted within the framework of comparative functional morphology of mammalian skin (Sokolov 1982) and “Trichomorphology” (Hausmann 1930; 1944; Teerink 1991) focusing in particular on specialized tactile organs such as whiskers (vibrissae). The architecture of vibrissae was studied for the first time using SEM in the relict rodent Laonastes aenigmamus and in some other representatives of the clade Ctenohystrica (Rodentia): Ctenodactylus gundi, Pectinator spekei, Proechimys guyannensis, Echimys sp., Trichomys apereoides, Chinchilla lanigera, and Octodon degus with the aim to identify the specific characters for each species. The vibrissal architecture is specific and polymorphic: the rod shape and structure of the medulla show differences between species of different genera and differ from those of guard hairs and spines of the same species. In L. aenigmamus, the vibrissal medulla is peculiar in its internal structure, which, together with the structure of guard hairs in this species, confirms its phylogenetically distinct position within Ctenohystrica. For the compared species, the complex medulla is with variously arranged systems of keratinized septa and different degrees of development of air spaces between them (ranging from unstructured and irregular to uni- or biserial ladder-like, cellated or pyramidal). The vibrissae have a non-specialized cuticle serving mostly for protection during tactile contacts, which distinguishes it from the diverse and multifunctional cuticle of guard hairs, spines, and quills. The tactile function of vibrissae is corroborated by the presence of scuff marks, scratches and even cuticle loss at the tip and on the ventral side of the rod, a thickened dense cortex and a poorly developed medullar layer but diverse its internal architecture, which provides only a very limited thermal protection, unlike that of the hair pelage. The SEM study of vibrissal architecture is a promising line of research, because a better knowledge of vibrissae may contribute to the biology and biomimetics.

Case Study

ABSTRACT This is a case study of a 55-year-old woman presenting with dystrophic nails that arose during her teenage years and has worsened over the last few years. The patient reported frequent wet work, exposure to irritants, and cuticle manipulation. The physical examination showed proximal nail fold bolstering, loss of cuticle, and a wavy dorsal nail plate resembling a “washboard.” She was diagnosed with chronic paronychia and onychotillomania. She was prescribed clobetasol ointment and sulfacetamide in ethanol and was counseled on hygiene and at-home care. One month after the regimen was started, there was noticeable reduction of inflammation to the cuticle.

Novel compound heterozygous cadherin 3 mutations in hypotrichosis and juvenile macular dystrophy.

Novel compound heterozygous cadherin 3 mutations in hypotrichosis and juvenile macular dystrophy.

Exoskeleton ageing and its relation to longevity and fecundity in female Australian leaf insects (

Senescence is a decline in reproduction and survival rate with advancing age resulting from deterioration of somatic tissues and systems throughout the body. Age-related somatic changes (somatic ageing) have been studied extensively in vertebrates but are less well known in other animals, including insects. Since adult insects have very limited ability to repair their exoskeleton, somatic ageing could involve deterioration and discolouration of the cuticle. We investigated age-related changes in wing pigmentation and abdominal cuticle necrosis in females of the Australian leaf insect Phyllium monteithi. Adult females varied markedly in the extent and pattern of pigmentation on their bodies, and we found that pigment spots on the forewings increased in size with age in most individuals. As females aged, most individuals also exhibited increasing levels of abdominal cuticle necrosis, resulting in the loss of abdominal cuticle along the margin of the abdomen. Neither the extent of pigmentation nor cuticle loss were clearly associated with reduced fecundity or longevity in the protected laboratory environment, but it remains unknown whether these age-related changes have functional implications in the wild. Our results show that the P. monteithi exoskeleton undergoes complex changes with age, with potential implications for functional traits and fitness.

Onychomycosis in onychodystrophy: a hospital-based clinico-mycological study

<p class="abstract"><strong>Background:</strong> Onychomycosis and onychodystrophy are both characterised clinically as disruption of nail plate characterised by thickening, disfiguration and discolouration. Onychomycosis in onychodystrophy is a diagnostic challenge. Similarly, onychodystrophy could also be treated unwarrantedly for fungus. Hence this study was carried out to determine the prevalence of onychomycosis in patients with onychodystrophy and to study the risk factors associated with the same.</p><p class="abstract"><strong>Methods:</strong> This descriptive study was done in 50 patients with onychodystrophy attending DVL OPD in a tertiary care hospital. After getting informed consent the nails were cleansed with absolute alcohol and nail clipping was taken for KOH and culture. The results were entered in a master sheet and analyzed.<strong></strong></p><p class="abstract"><strong>Results:</strong> Onycholysis, onychomadesis, chromonychia, thickened nail plate and loss of cuticle were the common features observed. Culture from 13/50 (26%) patients were found to be positive for fungal growth. In 13 patients with onychomycosis, 5 patients belonged to more than 50 years, seven patients (53.8%) were housewives. Three patients with onychodystrophy had psoriasis of which 2 (15.4%) patients proved positive for onychomycosis<em>. Aspergillus niger</em> 10 (76.9%) was the most common organism followed by <em>Rhizopus</em> 2 (15.4%) patients and 1 (7.7%) patient with <em>Geotrichium candidum</em>.</p><p class="abstract"><strong>Conclusions:</strong> We concluded that prevalence of onychomycosis in patients with onychodystrophy was 26%. Male gender, age >50, household activities and wetworks were associated risk factors of onychomycosis. Since clinical diagnosis of onychomycosis in onychodystrophy is difficult, appropriate lab investigations like KOH mount and fungal culture should be made mandatory to enable better patient care and clinical outcome.</p>

Sea Star Wasting Disease in Asterias forbesi along the Atlantic Coast of North America.

As keystone species, sea stars serve to maintain biodiversity and species distribution through trophic level interactions in marine ecosystems. Recently, Sea Star Wasting Disease (SSWD) has caused widespread mass mortality in several sea star species from the Pacific Coast of the United States of America (USA) and Asterias forbesi on the Atlantic Coast. A densovirus, named Sea Star associated Densovirus (SSaDV), has been associated with the wasting disease in Pacific Coast sea stars, and limited samples of A. forbesi. The goal of this research is to examine the pathogenesis of SSWD in A. forbesi on the Atlantic Coast of the USA and to determine if SSaDV is associated with the wasting disease in this species. Histological examination of A. forbesi tissues affected with SSWD showed cuticle loss, vacuolation and necrosis of epidermal cells, and oedema of the dermis, but no consistent evidence indicating the cause of the lesions. Challenge experiments by cohabitation and immersion in infected water suggest that the cause of SSWD is viral in nature, as filtration (0.22 μm) of water from tanks with sea stars exhibiting SSWD did not prevent the transmission and progression of the disease. Death of challenged sea stars occurred 7–10 d after exposure to infected water or sea stars, and the infectivity crossed species (A. forbesi and Pateria miniata) with equal penetrance. Of the 48 stars tested by quantitative real time PCR, 29 (60%) were positive for the SSaDV VP1 gene. These stars represent field-collected sea stars from all geographical regions (South Carolina to Maine) in 2012–2015, as well as stars exposed to infected stars or water from affected tanks. However, a clear association between the presence of SSaDV and SSWD signs in experimental and field-collected A. forbesi was not found in this study.

Age-dependent damage of hair cuticle: contribution of S100A3 protein and its citrullination.

There are two types of damage pattern of human hair cuticle: type L, where the cell membrane complex is split and the cuticle lifts up, and type E, where the fragile substructure of the cuticle cell (endocuticle) is broken. In our previous paper, it was reported that the dominant damage pattern shifts from type L to E with the subjects' age around the 40s. Loss of the cuticle due to daily grooming stresses increases with the subjects' age and is related to the level of type E damage. It is supposed that deterioration of endocuticle advances the loss of cuticle. S100A3 protein, located at the endocuticle, was found to be citrullinated and transformed into tetramer to improve its Ca(2+) -binding ability. It is postulated that this biochemical property affects the maturation of cuticle and contributes to its reinforcement. This study aims to elucidate the role that S100A3 plays in age-dependent cuticle damage. Hair fibers collected from Japanese females were evaluated for the content and citrullination rate of S100A3, incidence of type E damage, and resistance of cuticle. In the aged hair, the content of S100A3 was positively correlated with the level of type E damage and low resistance to stress. Hair fibers in which S100A3 is highly citrullinated, however, showed low levels of type E damage and high resistance of cuticle, even in the aged hair as well as at younger ages. S100A3 and its citrullination process are related to rigidity of endocuticle of aged hair.

Age-dependent changes in damage processes of hair cuticle.

Human hair cuticle is always exposed to various stresses and then gradually lost in daily life. There are two typical patterns of cuticle damage: type L, where the cell membrane complex, the structure located between cuticle cells, is split and the cuticle lifts up, and type E, where the fragile substructure of the cuticle cell (endocuticle) is damaged so that its rugged residue is exposed. We previously reported that type L damage preferentially occurs in the case of Japanese females in their 20s to 40s. This study aims to elucidate the age-dependent change of cuticle and its effect on hair properties. Hair fibers collected from Japanese females (ranging from 10 to 70years old) were evaluated in the aspects of inclination for each type of damage, resistance of cuticle against grooming stresses and content of fatty acid 18-MEA on hair surface. It was revealed that the dominant damage pattern shifts from type L to E with aging. Furthermore, the cuticle becomes gradually less resistant to daily grooming stress. The dominance of type E damage accelerates cuticle loss. Reduction of 18-MEA on weathered hair is accelerated with aging on elder hair. It has been reported that various age-dependent changes of whole hair shaft, such as diameter, density, elasticity, etc., occur in the age range of 40s and 50s. In this study, it was revealed that cuticle becomes more fragile and the hair surface properties deteriorate in the same age range.

Multiple habit-induced nail problems including diffuse brownish chromonychia.

Dear Editor: Chromonychia is the discoloration of the nail plate or subungual soft tissue with various causes1. Exogenous causes such as occupational agents, trauma or infection may provoke nail color change, and rarely, overproduction or storage of endogenous pigments is also responsible for chromonychia1,2. External dye stains the nail plate along the proximal fold, whereas endogenous pigmentation follows the shape of the lunula2. Melanonychia is a specific type of chromonychia with brown or black pigmentation1. Several reports have indicated that nail associated habits induce longitudinal melanonychia3,4,5, but none mentioned diffuse brownish chromonychia. Herein, we report a case of brownish chromonychia occurred with other nail deformities because of nail irritating habits. This study is approved by Catholic Medical Center (IRB No. SC13RISI0039). A 15-year-old girl presented with diffuse dark brown discoloration of the fingernails for several months. The patient had no remarkable medical or family history. The physical examination revealed brownish chromonychia, periungual erythema and swelling, cuticle loss and nail pitting on the left 3rd, 4th, and 5th fingernails (Fig. 1A). Onychoschizia and onycholysis with irregular grooves on the left thumbnail were also detected (Fig. 1C). Moreover, her right 4th fingernail had a longitudinal depression on its medial side (Fig. 2A). She said that she had been poking under the proximal nail folds of the left 3rd, 4th, and 5th fingers with the lead of a mechanical pencil. She had been sucking and biting the left thumbnail and had a peculiar pencil grip that was supported by the right 4th fingernail (Fig. 2B). Fig. 1 (A) Brown chromonychia on the left 3rd, 4th, and 5th fingernails. (B) After 4 months of treatment. (C) Onychoschizia and onycholysis with irregular grooves on the left thumbnail. (D) Left thumbnail fully recovered after 4 months of treatment. Fig. 2 (A) A longitudinal groove on the right 4th fingernail. (B) Probably the effect of a peculiar pencil grip. Because the patient's nail trauma history and development of melanonychia presented sequentially, we considered a strong association between them and delayed nail matrix biopsy. We educated her on discontinuing all habits and applying diflucortolone valerate 0.3% ointment to the periungual area of the affected fingernails regularly. In 4 months of follow-up, the fingernails gradually restored their natural shapes and colors (Fig. 1B, D). Because of the diffuse brownish pigmentation along the proximal nail fold and obvious improvement after stopping habit, we presumed that the lead had stained the nail plate. Repetitive mechanical stimulation on the nail matrix such as picking, chewing, breaking or rubbing would fluctuate the nail formation and make nail thickness irregular1,3. These habitual behaviors are easily seen in children, as 60% of children and 45% of teenagers are indulged in onychophagia1. In our case, we observed diffuse brownish chromonychia with other forms of nail deformities caused soley by her habits. Observing multiple nail problems in different fingers of a patient simultaneously is notable, because habit induced nail problem usually occurs as one type at a time. Fortunately, she managed to stop all habits so that the disfigurements improved. Occasionally, children with onychophagia may need psychiatric consultation for the obsessive-compulsive features and treatment with a selective serotonin reuptake inhibitor1. Thorough history taking and physical examination would be enough for diagnosis in children with nail irritating behaviors, avoiding unnecessary invasive examination including nail matrix biopsy4,5.

Toxicity of cerium oxide nanoparticles to the earthworm Eisenia fetida: subtle effects

Environmental context This study investigates the toxicity of cerium oxide nanoparticles to earthworms, key organisms in soil ecosystems. Cerium oxide did not affect survival or reproduction of the earthworms but did exert histological changes. We conclude that current soil guidelines, based simply on metal toxicity, appear to adequately protect against cerium exposure risk, at least for earthworms. Abstract The toxicity of cerium oxide (CeO2) nanoparticles (NPs) in soils is largely unknown. This study aimed to investigate the toxicity of three different CeO2 NPs to the earthworm, Eisenia fetida, for effects on survival (at day 28) and reproduction (at day 56), as well as bioaccumulation and histopathological effects. Eisenia fetida were exposed in standard Lufa 2.2 soil to three CeO2 NPs of different size ranges (5–80nm), one larger particle (300nm) and a cerium salt (ammonium cerium nitrate) over an exposure range from 41–10000mgCekg–1. Survival and reproduction were not affected by the four CeO2 particles, even at the highest exposure concentration tested. Alternatively, 10000mgCekg–1 cerium salt affected survival and reproduction; Median lethal concentration (LC50) and effective concentration (EC50) values were 317.8 and 294.6mgCekg–1. Despite a lack of toxic effect from the different forms of CeO2 particles, there was a dose-dependent increase in cerium in the organisms at all exposure concentrations, and for all material types. Earthworms exposed to CeO2 particles had higher concentrations of total cerium compared to those exposed to ionic cerium, but without exhibiting the same toxic effect. Histological observations in earthworms exposed to the particulate forms of CeO2 did, however, show cuticle loss from the body wall and some loss of gut epithelium integrity. The data suggest that that CeO2 NPs do not affect survival or reproduction in E. fetida over the standard test period. However, there were histological changes that could indicate possible deleterious effects over longer-term exposures.

Characterization of hair follicles in Hirosaki hairless rats with deletion of basic hair keratin genes. Enlarged medulla, loss of cuticle and long catagen

Characterization of hair follicles in Hirosaki hairless rats with deletion of basic hair keratin genes. Enlarged medulla, loss of cuticle and long catagen

Effects of mutations at the stambh A locus of Drosophila melanogaster.

We report novel findings on the cytogenetic location, functional complexity and maternal and germline roles of the stambh A locus of Drosophila melanogaster. stmA is localized to polytene bands 44D1.2 on 2R. stmA mutations are of two types: temperature-sensitive (ts) adult and larval paralytic or unconditional embryonic or larval lethal. Twelve alleles reported in this study fall into two intragenic complementing groups suggesting that stmA is a complex locus with more than one functional domain. Some unconditional embryonic lethal alleles show a 'neurogenic' phenotype of cuticle loss accompanied by neural hypertrophy. It is shown that embryos of ts paralytic alleles also show mild neural hypertrophy at permissive temperatures while short exposure to heat induces severe cuticle loss in these embryos. stmA exerts a maternal influence over heat-induced cuticle loss. Unconditional embryonic lethal alleles of stmA are also germline lethal.

Effect of Retting Enzymes on the Structure and Composition of Flax Cell Walls

Commercial enzyme mixtures are tested for their possibly selective degradation of flax ( Linum usitatissimum L.) stem components in relation to the retting process in producing linen. Structural and chemical compositional results from treatments are obtained using scanning electron microscopy, histochemistry, gas-liquid chromatography, 13C cp mas nmr spectrometry, and mid-infrared spectroscopy. Flaxzyme and Ultrazym and an enriched pectinase mixture (epm), which was not developed for flax retting but is included for comparison, are tested for their activity toward cell wall components and used in various concentrations for “enzyme-retting” of flax. Ariane flax stem sections are incubated with enzymes in a rotary incubator and the fibers are manually separated from the residual core. All of the commercial enzyme mixtures have cellulase, pectinase, and hemicellulase activities, but individual enzyme activities vary. Activities against the soluble test substrates do not predict the activity against natural fibers. At about equal protein concentrations, Flaxzyme treatment appears to facilitate bast fiber removal better than the other enzymes, with Ultrazym nearly as effective and epm the least effective. The ranking of effectiveness is generally supported by the amounts of uronic acid, arabinose, and xylose removed from the stems analyzed chemically. Increased enzyme levels generally facilitate removal of matrix carbohydrates from the flax. All enzymes separate bast fibers from the lignified core and partially from the cuticle near the cut surface of the stem sections, but the enzymes do not work far from the exposed ends. Retting quality is defined more by the degree of cell wall degradation and fiber separation than by any differences in kinds of cell walls degraded by the various enzymes. The cuticle remains attached to the fiber at times, apparently reducing access of the enzymes to the matrix polysacchrides and suggesting some recalcitrance of epidermal cells (and therefore loss of cuticle) to biodegradation. Lignin remains in the middle lamellae after enzyme retting and would likely prevent separation of the fiber bundles. Some solubilzation of the inner secondary wall of the flax fiber appears to occur with Flaxzyme. The structural and chemical analyses characterize alterations in flax bast after enzyme retting and would be useful in ranking the specificity and effectiveness of cell wall degradation.

Weathering of hair in trichothiodystrophy.

The structure of hairs from three patients with sulphur-deficient hair, trichothiodystrophy, has been studied by light, plane-polarizing and scanning electron microscopy. Severe cuticular and secondary cortical degeneration was evident along almost the entire length of the hair shaft, with cuticle loss, trichorrhexis nodosa formation and trichoschisis. The severity of these changes varied between patients. The role of the cuticle in protecting hair from environmental damage is discussed.

Comparison of Two Methods of Fecal Analysis of Herbivore Diet

Two techniques for determining the proportions of different plant species eaten by the brushtailed opossum (Trichosurus vulpecula) were compared. Both techniques-bacterial degradation and chemical maceration of feces-produced similar results, and confirmed that a correction factor is needed to allow for the differential loss of cuticle of some plant foods during digestion or preparation of feces for microscopic examination. J. WILDL. MANAGE. 43(2):468-473 A reliable method for measuring the species composition and proportions of foods in the diet of herbivores is required; this is especially important where the management of animals or vegetation is contemplated. All the techniques used have drawbacks. Directly observing the feeding animals or the resulting browsed or grazed vegetation to assess species and amounts eaten does not always give accurate results (Wallmo et al. 1973). Examining the macroor microscopic contents of stomachs or rumens is not practicable on live animals, and the results may be unreliable (Westoby et al. 1976). Examining the microscopic fragments in feces is potentially 1 of the best ways, but this can be difficult, and some workers doubt the accuracy of the results obtained (Slater and Jones 1971). However, an advantage of this method is the ease of collecting and storing material. Fresh fecal samples can be kept refrigerated in air-tight containers, or stored in a simple preservative such as 70% ethanol. One of the problems associated with fecal analysis is that of identifying the plant fragments seen on the microscope slide. For predominantly leaf-eating animals, including most ungulates and the brush-tailed opossum, this is simplified by the characteristic shape and arrangement of the epidermal cells of the leaves of each plant species. These features are molded on the overlying cutin, which is indigestible and passes through the gut of herbivores. Some cuticles, however, may break down physically to such an extent that they cannot be recognized. A number of herbs, grasses, and more fragile-leaved tree species have long cells of the epidermis that are too poorly defined to produce a diagnostic cuticle, but they almost always have characteristic stomata, cell inclusions, glands, or hairs, particularly on the abaxial surface of the leaf. Thus, in most cases identification is possible with the aid of a reference collection of representative leaf cuticles. Identifying fragments of food items other than leaves may not be so straightforward. Seeds may be identified either macroor microscopically, and fragments of flowers, petioles, stems, fruit, and other plant parts may sometimes be identified to species. However, even when the available or likely food plants are known, the preparation of reference material to include all these plant parts is very time consuming and often impracticable. 468 J. Wildl. Manage. 43(2):1979 This content downloaded from 157.55.39.181 on Thu, 29 Sep 2016 06:16:05 UTC All use subject to http://about.jstor.org/terms FECAL ANALYSIS OF HERBIVORE DIET Fitzgerald and Waddington 469 A more intractable problem with food studies using fecal analysis is determining whether the proportions in which various species are represented on the microscope slides are similar to the proportions in which they were eaten, or whether the digestive processes of the animal and the methods of preparing material have altered the proportions. Various techniques have been used to prepare fecal material for microscopic examination. For example, Dusi (1949) and Voth and Black (1973) used chloral hydrate solution to clear the cuticle fragments. Martin (1955) and Stewart (1967) used nitric acid to macerate the fecal samples, removing mesophyll while leaving cuticles identifiable, while Dunnet et al. (1973) used a mixture of nitric acid and chromic acid. Williams (1969), after initial mechanical preparation of fecal samples, added boiling water and finally sodium hypochlorite (domestic bleach). Cuticles can also be separated by macerating the plant material with bacteria. This method has been used by Skoss (1955) to study the structure and composition of cuticles, by Luow et al. (1949) on rumen samples, and by Rogerson et al. (1976) on feces from sheep. Rogerson et al. claimed that this is a simpler and more effective technique than chemical preparation, and that it gave repeatable results in terms of botanical composition. To test this claim, we attempted to compare the bacterial technique with the chemical one used by Dunnet et al. (1973) and Fitzgerald (1976) in studies of the diet of the brush-tailed opossum. We also took the opportunity to validate, for each plant species eaten, the use of predetermined correction factors which take into account both the destructive effect of nitric-chromic acid and the digestive processes of the animals. We are grateful to R. E. Brockie, D. G. Dawson, M. R. Rudge, and B. M. Fitzgerald for help with this paper.