Tension as a key factor in skin responses to pollution.

Being the more apparent organ exposed to the outdoor stressors, the effect of pollution on the skin has been widely studied in the last few decades. Although UV light is known as the most aggressive stressor to which our cutaneous tissue is daily exposed, other components of the tropospheric pollution have also shown to affect skin health and functionality. Among them, ozone has been proven to be one of the most toxic due to its high reactivity with the epidermal lipids. Studying the cutaneous effect of pollution in a laboratory setting presents challenges, therefore it becomes critical to employ appropriate and tailored models that aim to answer specific questions. Several skin models are available nowadays: in vitro models (2D cell lines and 3D cutaneous tissues), ex vivo skin explants and in vivo approaches (animals and humans). Although in the last 20 years researchers developed skin models that closely resemble human skin (3D cutaneous tissues), ex vivo skin explants still remain one of the best models to study cutaneous responses. Unfortunately, one important cutaneous property that is not present in the traditional ex vivo human skin explants is the physiological tension, which has been shown to be a cardinal player in skin structure, homeostasis, functional properties and responses to external stimuli. For this reason, in this study, to confirm and further comprehend the harmful mechanism of ozone exposure on the integumentary system, we have performed experiments using the state of art in cutaneous models: the innovative TenSkin™ model in which ex vivo human skin explants are cultured under physiologically relevant tension during the whole experimental procedure. Specifically, we were interested in corroborating previous findings showing that ozone exposure modulates the expression of cutaneous antimicrobial peptides (AMPs). The present work demonstrates that cutaneous exposure to ozone induces AMPs gene and protein levels (CAMP/LL-37, hBD2, hBD3) and that the presence of tension can further modulate their expression. In addition, different responses between tension and non-tension cultured skin were also observed during the evaluation of OxInflammatory markers [cyclooxygenase-2 (COX2), aryl hydrocarbon receptor (AhR), matrix-metallo-proteinase 9 (MMP9) and 4-hydroxy-nonenal (4HNE)]. This current study supports our previous findings confirming the ability of pollution to induce the cutaneous expression of AMPs via redox signaling and corroborates the principle that skin explants are a good and reliable model to study skin responses even though it underlines the need to holistically consider the role of skin tension before extrapolating the data to real life.

The tight attachment achieved by the male discoidal setae is possibly a counter-adaptation to the grease layer on female integument surfaces in green dock beetles.

Green dock beetles Gastrophysa viridula exhibit sexual dimorphism in tarsal attachment setae: females have only pointed, lanceolate and spatula-like setae, while males additionally possess discoidal ones. The sexual dimorphism is probably attributed to the necessity of male discoidal setae to adhere to the smooth back of the female during copulation. We aimed to understand its possible mechanism of attachment with G. viridula. Pull-off forces of both females and males were measured on (i) alive females, (ii) dead and dried females, and (iii) resin replicas of fresh females. The attachment ability tended to increase on dead and replicated female surfaces in both sexes, which indicates that the epicuticular grease layer on the integument of alive intact beetles decreases the attachment. This tendency was prominent in females. The present study clearly showed that in G. viridula discoidal setae enable the males to adhere stronger to female surfaces. The divergent performance found between the sexes differing in their setal composition is probably caused by the stiffness difference between the setae types and by the specific shape of the setal tips. A peculiar reproductive biology in G. viridula is probably attributed to this remarkable divergence of labour in their attachment pads between the sexes.

SeBLOS2 knockout via CRISPR/Cas9 leads to the loss of larval integument coloration in Spodoptera exigua (Lepidoptera: Noctuidae).

CRISPR/Cas9 technology is a precise and powerful tool for functionally exploring insect genes. The present study tested CRISPR/Cas9 as a way of undertaking effective gene mutagenesis in an important agricultural pest, the beet armyworm Spodoptera exigua. Based on a S. exigua transcriptome database, the entire complementary DNA sequence of SeBLOS2 encoding 140 amino acid residues was cloned. The gene was highly expressed in late larval stages (L3-L5). Using the CRISPR/Cas9 method, SeBLOS2 was knocked out by altering two sites in the coding region. This resulted in 70%-74% of the G0 generation (L4-L5) larvae displaying mosaic translucent integument. Four different mutations occurred at SeBLOS2-specific target sites, as demonstrated by further polymerase chain reaction-based genotypic analysis. Homozygote mutant L3 larvae were obtained in the G1 generation, with complete loss of white stripes and spots on their larval integument. These results demonstrate a crucial role of SeBLOS2 in integument pigmentation and suggest that the gene can act as a suitable nonlethal marker for functional research on genes in S. exigua and other Lepidopteran pests.

Route of pesticide spread on the body surface of Blattella germanica (Linnaeus): a NanoSuit-energy dispersive X-ray spectroscopy analysis.

Numerous studies have focussed on the mechanisms of entry of pesticides into insect body parts such as oral intake, penetration through the integument of the body wall, and inhalation through spiracles. However, little is known about how insecticides spread to the points of entry or the paths on the body surface that are used to reach the target sites. In this study, elemental signals of pesticide-mimicking test solutions were tracked and their routes of spreading in experimental insects (Blattella germanica L.) were investigated using NanoSuit (a method of surface modification) and energy dispersive X-ray spectroscopy, combined with high-resolution scanning electron microscopy. When the test solution initially adhered to the dorsal and/or ventral body surface, it tended to spread horizontally to reach lateral plates. Whereas, when the solution directly adhered to the anterior side of the lateral plates, it spread to posterior segments. In this case, however, spreading in the opposite direction (i.e., the solution directly adhered to the posterior side of the lateral plates) was interrupted at a boundary erected by different groups of fine structures; each protrusion was large, and the arrangement was rather dense in the posterior segments. Morphological features of these fine structures and chemical characteristics of the hydrophobic surface substances potentially regulate the strength of the capillary force, which determines pesticide spreading.

Wake-like skin patterning and neural activity during octopus sleep.

While sleeping, many vertebrate groups alternate between at least two sleep stages: rapid eye movement and slow wave sleep1-4, in part characterized by wake-like and synchronous brain activity, respectively. Here we delineate neural and behavioural correlates of two stages of sleep in octopuses, marine invertebrates that evolutionarily diverged from vertebrates roughly 550 million years ago (ref. 5) and have independently evolved large brains and behavioural sophistication. 'Quiet' sleep in octopuses is rhythmically interrupted by approximately 60-s bouts of pronounced body movements and rapid changes in skin patterning and texture6. We show that these bouts are homeostatically regulated, rapidly reversible and come with increased arousal threshold, representing a distinct 'active' sleep stage. Computational analysis of active sleep skin patterning reveals diverse dynamics through a set of patterns conserved across octopuses and strongly resembling those seen while awake. High-density electrophysiological recordings from the central brain reveal that the local field potential (LFP) activity during active sleep resembles that of waking. LFP activity differs across brain regions, with the strongest activity during active sleep seen in the superior frontal and vertical lobes, anatomically connected regions associated with learning and memory function7-10. During quiet sleep, these regions are relatively silent but generate LFP oscillations resembling mammalian sleep spindles11,12 in frequency and duration. The range of similarities with vertebrates indicates that aspects of two-stage sleep in octopuses may represent convergent features of complex cognition.

Oxidative Stress Status and Its Relationship to Skin Aging.

Skin and cellular aging are impacted by various toxins in our environment such as air pollution, water contamination, an increased prevalence of light-emitting diodes, electromagnetic frequencies, various yeast and other fungi, parasitic infections, and mold and heavy metal toxicity. Basic topical skin care is insufficient to adequately protect an individual's integumentary system and other organs from these types of daily cellular stressors. These stressors impact the level of oxidative stressstatus (OSS). OSS is measurable through biomarker analysis of various body fluids including blood, saliva, urine, and breath. This poses a unique assessment challenge for aesthetic practitioners as the OSS of a patient impacts their overall aging process. Aesthetic practitioners observe the aging process through visual assessment of a patient's skin quality, skin barrier function, and the presence of solar lentigines, erythema, edema, telangiectasia, loss of collagen and elastin, bone density, and redistribution of subcutaneous tissue. Mitigating a patient's daily exposure to OS and its impacts on the skin, other organ tissues, and metabolism poses a unique challenge in medical aesthetic treatment planning. For this reason, the use of stem cells and exosomes is gaining popularity in aesthetic medicine. The purpose of this literature review is to highlight currently available research, applications, limitations, and mitigation strategies in reducing OSS on the integumentary system and aging processes.

Manejo de reações adversas dermatológicas em pacientes submetidos à terapia quimioterápica antineoplásica / Management of dermatological adverse reactions in patients undergoing antineoplastic chemotherapy

Objetivo: o presente estudo tem como objetivo reunir recomendações de cuidados considerando a prevenção e tratamento de lesões de pele induzidas pelo tratamento com quimioterápicos antineoplásicos, de acordo com os estudos e consensos atuais. Metodologia: realizou-se um estudo bibliográfico para levantamento das relações entre os principais fármacos antineoplásicos e suas intercorrências dermatológicas, bem como seus respectivos manejos, para subsidiar a orientação e aconselhamento aos profissionais de saúde que acompanham o paciente oncológico. Resultado: os principais problemas dermatológicos decorrentes do uso de antineoplásicos correspondem às lesões de pele, tais como a descoloração, hiperpigmentação, fotossensibilidade, eritemas, descamação e prurido. Também são recorrentes os efeitos adversos que acometem os pelos e cabelos, resultando em alopecia, e a modificação do crescimento e lesões nas unhas. Tratamentos específicos para cada caso são capazes de amenizar ou reverter os problemas. Conclusão: as reações adversas aos medicamentos envolvendo quimioterapia são frequentes na prática oncológica, e variam em termos de frequência e gravidade, atingindo diversos anexos cutâneos. O adequado manejo destes efeitos melhora a integridade da pele e demais estruturas, proporcionando a esses pacientes a melhoria da autoestima e da qualidade de vida.

Objective: the present study aims to gather care recommendations considering the prevention and treatment of skin lesions induced by treatment with antineoplastic chemotherapy, according to current studies and consensus. Methodology: a bibliographical study was carried out to survey the relationships between the main antineoplastic drugs and their dermatological intercurrences, as well as their respective management, to subsidize the guidance and counselling of health professionals who treat cancer patients. Result: the main dermatological problems arising from the use of antineoplastic agents correspond to skin lesions, such as discoloration, hyperpigmentation, photosensitivity, erythema, scaling and pruritus. Adverse effects that affect hair and body hair are also recurrent, resulting in alopecia, and the modification of growth and lesions on the nails. Specific treatments for each case can alleviate or reverse the problems. Conclusion: adverse drug reactions involving chemotherapy are frequent in oncology practice, and vary in terms of frequency and severity, affecting various skin appendages. Proper management of these effects improves the integrity of the skin and other structures, providing these patients with improved self-esteem and quality of life.

Microscopic anatomy of the integument in the ribbon worm Micrura bella (Stimpson, 1857) (Pilidiophora, Nemertea).

The integument of ribbon worms in the order Heteronemertea is distinct from the integuments in the other taxa of nemerteans due to the presence of a special subepidermal glandular layer, the cutis. Among heteronemerteans, the ultrastructure of the cutis has been studied only in the Lineus ruber species complex. In the current study, ultrastructural (transmission electron microscopy) and histochemical studies of the epidermis and the cutis of Micrura bella from the basal Lineage A of the family Lineidae were performed. The epidermis consisted of ciliated and serous gland cells and is separated from the cutis by a layer of the subepidermal extracellular matrix; the basal lamina was not detected. The cutis comprised musculature, two types of mucous and four types of granular gland cells, and pigment cells with four types of granules. In the cutis of juvenile worms, type II granular gland cells and type II mucous cells were not observed. The integument of the caudal cirrus consisted of ciliated and serous gland cells and two intraepidermal lateral nerve cords; the cutis was absent. The compositions of the integument glands of M. bella and the L. ruber species complex are similar, except for the presence of type IV granular gland cells with narrow rod-shaped and lamellated granules exhibiting an alternating dark and light transverse layers and type II mucous cells found only in M. bella.

Morphological ontogeny of Carinogalumna erciyesi sp. nov. (Acari, Oribatida, Galumnidae) from Turkey, with comments on Carinogalumna Engelbrecht.

The morphological ontogeny of Carinogalumna erciyesi sp. nov. from Turkey is described and illustrated. The adult of this species is most similar to that of C. montana Engelbrecht, 1973 but differs from it mainly by the shape of the bothridial seta and porose areas Aa and A2. The larva of C. erciyesi has 12 pairs of gastronotal setae, including alveolar h3, nymphs have 15 pairs; most setae are of medium size and barbed, except for short p2 and p3, smooth in protonymph; setae p2 and p3 are inserted on unsclerotized integument. In all juveniles the bothridial seta is clavate with long, narrow, barbed head. The gastronotal shield is well-developed with setae of d-, l-series and h1 in the larva, and of d-, l-, h-series and p1 in the nymphs. Setae of c-series of juveniles are inserted on microsclerites, and genital opening is placed on a large sclerite. In all juveniles a humeral organ is present, with porose area above it.

Redescription of three species of Aponychus from China with ontogenetic development and morphological variations of A. corpuzae (Acariformes: Tetranychidae).

Ontogenetic development of leg chaetotaxy, stylophore and striae of the dorsal integument, and variations of leg setal counts and length of idiosomal setae in Aponychus corpuzae are discussed. The following changes were observed during the ontogenetic development of A. corpuzae: the depth of the depression in stylophore increases; the dorsal striae gradually reduce in number and prominence; the length of dorsal setae sc1, c12, d12 and e1 reduce in size; adult dorsal setae much thicker than those of immature stages. There are a significant number of setae suppressed in A. corpuzae, often resulting in unique patterns and sexual dimorphism. The adult males and females of Aponychus firmianae and A. taishanicus from mainland China are redecribed, and a key to all Aponychus from mainland China is provided.

Morphological ontogeny of Zachvatkinibates svanhovdi (Acari, Oribatida, Punctoribatidae).

The morphological ontogeny of Zachvatkinibates svanhovdi A. Seniczak & S. Seniczak, 2023 is described and illustrated. The juveniles of this species are light brown with slightly darker colour on the prodorsum, gastronotal shield, surrounding of gla opening, and legs. The larva has 12 pairs of gastronotal setae, most are of medium size and barbed; the nymphs have 15 pairs, most are short and smooth. In all juveniles, the setae of c-series are inserted on unsclerotized integument. In the larva, the pygidial shield is absent but, in the nymphs, the gastronotal shield is present and the setae p2 and p3 are inserted on unsclerotized integument. In the larva, a humeral organ is absent but is present in the nymphs.

CPR Gene Contributes to Integument Function and Ovary Development in a Rice Planthopper.

Nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P450 reductase (CPR) is an essential enzyme that transfers electrons from NADPH to cytochrome P450 monooxygenases. CPR is involved in cuticular hydrocarbon (CHC) synthesis in insects and is vital for insect development and survival. Here, we clarify the physiological function of a CPR gene in Nilaparvata lugens, an important rice pest, by using RNA interference. CPR gene knockdown leads to the functional loss of waterproofing and water retention in the integument of female adults, which causes significantly reduced body weight and a lethal phenotype. Scanning electron microscopy shows that the lipid layer on the outermost surface of the abdominal cuticle becomes thin in dsCPR-injected adults. Furthermore, CHC profile analysis reveals that CPR knockdown significantly decreases the contents of CHCs with a carbon chain length ≥ C27 in adult females. Moreover, we find that CPR knockdown generates a deficient phenotype in ovaries with deformed oocytes and a complete failure of egg-laying. These findings suggest that CPR plays multiple functional roles in CHC biosynthesis and embryo development in insects.

A CYP380C10 gene is required for waterproofing and water retention in the insect integument.

Cuticular hydrocarbons (CHCs) are important components in the integument of insects and are required for development and survival. Insect-specific CYP4G subfamily, of the P450 enzymes, catalyze the oxidative decarbonylation step in the biosynthesis of CHCs. Here, we characterized CYP380C10 gene function in a Hemiptera rice pest, Nilaparvata lugens. We used RNA interference-mediated expression silencing to reveal that NlCYP380C10 played a key role in waterproofing and water-retention in the integument of N. lugens. Knockdown of NlCYP380C10 significantly reduced body weight and caused mortality. Scanning electron microscopy showed the loss of the lipid layer on the surface of the abdominal cuticle of the dsNlCYP380C10-injected adults. Furthermore, CHC profile analysis revealed that NlCYP380C10 knockdown significantly decreased the amounts of CHCs in adult females. This suggested that NlCYP380C10 was involved in CHC biosynthesis. Reduction of CHC content caused the loss of the intact lipid layer of the cuticle, which resulted in loss of the waterproofing and water-retention functions. This led to failure of molting and eclosion. Our findings expanded the knowledge of CHC biosynthesis in the insect integument and led to a better understanding of the functional roles of CYP450 genes involved in waterproofing and water-retention in insects.

A new Early Cretaceous lizard in Myanmar amber with exceptionally preserved integument.

We here report on a well-preserved juvenile lizard specimen in Albian amber (ca. 110 mya) from the Hkamti site (Myanmar). This new taxon is represented by an articulated skull and the anterior portion of the trunk, including the pectoral girdle and forelimbs. The scleral ossicles and eyelid are also visible, and the specimen exhibits pristine detail of the integument (of both head and body). In a combined molecular and morphological analysis, it was consistently recovered as a scincoid lizard (Scinciformata), as sister to Tepexisaurus + Xantusiidae. However, the phylogenetic position of the new taxon should be interpreted with caution as the holotype is an immature individual. We explored the possibility of miscoding ontogenetically variable characters by running alternative analyses in which these characters were scored as missing data for our taxon. With the exception of one tree, in which it was sister to Amphisbaenia, the specimen was recovered as a Pan-xantusiid. Moreover, we cannot rule out the possibility that it represents a separate lineage of uncertain phylogenetic position, as it is the case for many Jurassic and Cretaceous taxa. Nonetheless, this fossil offers a rare opportunity to glimpse the external appearance of one group of lizards during the Early Cretaceous.

Comparison of vertebrate skin structure at class level: A review.

The skin is a barrier between the internal and external environment of an organism. Depending on the species, it participates in multiple functions. The skin is the organ that holds the body together, covers and protects it, and provides communication with its environment. It is also the body's primary line of defense, especially for anamniotes. All vertebrates have multilayered skin composed of three main layers: the epidermis, the dermis, and the hypodermis. The vital mission of the integument in aquatic vertebrates is mucus secretion. Cornification began in apmhibians, improved in reptilians, and endured in avian and mammalian epidermis. The feather, the most ostentatious and functional structure of avian skin, evolved in the Mesozoic period. After the extinction of the dinosaurs, birds continued to diversify, followed by the enlargement, expansion, and diversification of mammals, which brings us to the most complicated skin organization of mammals with differing glands, cells, physiological pathways, and the evolution of hair. Throughout these radical changes, some features were preserved among classes such as basic dermal structure, pigment cell types, basic coloration genetics, and similar sensory features, which enable us to track the evolutionary path. The structural and physiological properties of the skin in all classes of vertebrates are presented. The purpose of this review is to go all the way back to the agnathans and follow the path step by step up to mammals to provide a comparative large and updated survey about vertebrate skin in terms of morphology, physiology, genetics, ecology, and immunology.

Melanin synthesis genes BgTH and BgDdc affect body color and cuticle permeability in Blattella germanica.

Melanin is involved in cuticle pigmentation and sclerotization of insects, which is critical for maintaining structural integrity and functional completeness of insect cuticle. The 2 key enzymes of tyrosine hydroxylase (TH) and dopa decarboxylase (DDC) predicted in melanin biosynthesis are usually conserved in insects. However, it is unclear whether their function is related to epidermal permeability. In this study, we identified and cloned the gene sequences of BgTH and BgDdc from Blattella germanica, and revealed that they both showed a high expression at the molting, and BgTH was abundant in the head and integument while BgDdc was expressed highest in the fat body. Using RNA interference (RNAi), we found that knockdown of BgTH caused molting obstacles in some cockroaches, with the survivors showing pale color and softer integuments, while knockdown of BgDdc was viable and generated an abnormal light brown body color. Desiccation assay showed that the dsBgTH-injected adults died earlier than control groups under a dry atmosphere, but dsBgDdc-injected cockroaches did not. In contrast, when dsRNA-treated cockroaches were reared under a high humidity condition, almost no cockroaches died in all treatments. Furthermore, with eosin Y staining assay, we found that BgTH-RNAi resulted in a higher cuticular permeability, and BgDdc-RNAi also caused slight dye penetration. These results demonstrate that BgTH and BgDdc function in body pigmentation and affect the waterproofing ability of the cuticle, and the reduction of cuticular permeability may be achieved through cuticle melanization.

Drenaje percutáneo ecoguiado vs. drenaje quirúrgico en abscesos cervicales profundos de origen odontógeno. Ensayo clínico controlado y aleatorizado / Ultrasound-guided drainage vs surgical drainage of deep neck space abscesses: A randomized controlled trial

Introducción: La causa más frecuente de infecciones profundas del cuello son las infecciones odontógenas. Son diagnosticadas con examen físico, estudios por imágenes, ecografía o tomografía computarizada. Debe realizarse siempre el drenaje quirúrgico de forma clásica o percutánea según el caso de las colecciones en forma precoz. El objetivo fue comparar las técnicas de drenaje percutáneo guiado por ecografía vs. drenaje quirúrgico en abscesos cervicales profundos de origen odontógeno en forma controlada y aleatorizada. Métodos: Se realizó un ensayo clínico controlado aleatorizado de enero de 2015 a diciembre de 2019. Se evaluó como variable de eficacia los días de ingreso. Se analizaron los datos epidemiológicos y variables secundarias (tumoración, trismus, fiebre, dolor), leucocitosis, resultado cosmético comparando ambas técnicas. El análisis estadístico se llevó a cabo con STATA v 14.0. Resultados: Fueron analizados 128 pacientes, 51 mujeres y 77 hombres. Edad promedio 27,3 (SD = 10,13). El grupo percutáneo presentó una media de 3,03 (SD = 2,86) días de ingreso y el grupo quirúrgico 5,46 (SD = 2,96). El valor de p resultó <0,001. Los resultados cosméticos mostraron diferencias favor del grupo de drenaje percutáneo. Ninguna de las demás variables mostró resultados estadísticamente significativos. Discusión: Ante la evidencia de una colección extensa en espacios profundos la realización del tratamiento quirúrgico (cervicotomía y desbridamiento) debe hacerse en forma precoz. Los procedimientos mínimamente invasivos guiados por imágenes son una alternativa. Estos pueden realizarse en colecciones bien localizadas, uniloculares, y siempre que no exista compromiso de la vía aérea del paciente. Pueden realizarse técnicas de punción y aspiración, y si es necesario en forma seriada, o bien punción con colocación de drenajes. (AU)

Introduction: The most common cause of deep neck infections is dental infection. They are diagnosed with physical examination, imaging studies, ultrasound, or computed tomography. Surgical drainage of collections should always be performed early in a classical or percutaneous way, depending on the case. The aim of the study was to compare ultrasound-guided percutaneous drainage techniques vs. surgical drainage in deep cervical abscesses of odontogenic origin in a controlled and randomized trial. Methods: A randomized controlled clinical trial was performed from January 2015 to December 2019. Hospital stay was evaluated as an efficiency variable. Epidemiological and secondary variable data (tumour, trismus, fever, pain), leukocytosis, cosmetic result comparing both techniques were analysed. Statistical analysis was carried out with STATA v 14.0. Results: 128 patients were analysed, 51 women and 77 men. Average age 27.3 (SD = 10.13). The percutaneous group had a mean hospital stay of 3.03 (SD = 2.86) days and the surgical group 5.46 (SD = 2.96). The p-value was <.001. Cosmetic results showed differences favouring the percutaneous drainage group. None of the other variables showed statistically significant results. Discussion: Surgical treatment (cervicotomy and debridement) should be undertaken early with evidence of extensive collection in deep spaces. Minimally invasive image-guided procedures are an alternative. These can be performed in well-located, unilocular collections, without compromising of the patient's airway. Percutaneous drainage and suction techniques if necessary, serially, or drainage placement may be performed. (AU)

Morphological ontogeny of Hermanniella septentrionalis (Acari, Oribatida, Hermanniellidae) and comments on Hermanniella Berlese.

The morphological ontogeny of Pilogalumna tenuiclava (Berlese, 1908) is redescribed and illustrated. The prodorsal setae of juveniles are of medium size or long and barbed, and bothridial seta is fusiform, with thick, barbed head. Larva has 11 pairs of gastronotal setae, including h2, most are short and smooth, except for longer and barbed c2, c3, dp, h1 and h2. The nymphs have 15 pairs of these setae, most are short and smooth, except for longer and barbed c3. Gastronotal shield of juveniles is poorly developed, with setae of d-, l-series, and h1 in the larva, and d-, l-, h-series and p1 in the nymphs, setae of c-series, p2 and p3 are inserted on unsclerotized integument. In all juveniles, a humeral organ is present.

Morphological ontogeny of Pilogalumna tenuiclava (Acari, Oribatida, Galumnidae) and comments on Pilogalumna Grandjean.

The morphological ontogeny of Pilogalumna tenuiclava (Berlese, 1908) is redescribed and illustrated. The prodorsal setae of juveniles are of medium size or long and barbed, and bothridial seta is fusiform, with thick, barbed head. Larva has 11 pairs of gastronotal setae, including h2, most are short and smooth, except for longer and barbed c2, c3, dp, h1 and h2. The nymphs have 15 pairs of these setae, most are short and smooth, except for longer and barbed c3. Gastronotal shield of juveniles is poorly developed, with setae of d-, l-series, and h1 in the larva, and d-, l-, h-series and p1 in the nymphs, setae of c-series, p2 and p3 are inserted on unsclerotized integument. In all juveniles, a humeral organ is present.

The bioactive compound carvacrol as a potential acaricide: An assessment of its effects on the integument of female Rhipicephalus sanguineus sensu lato ticks.

Studies seeking control methods for infestation of Riphicephalus sanguineus sensu lato (s.l.) ticks (dog ticks) have been carried out in order to minimize damage to both the tick's hosts and the environment, the latter due to the misuse of acaricide products. In this regard, carvacrol has been used as a natural alternative against ticks as it displays several properties including acaricidal. In this context, the present study aimed to evaluate the ultramorphology and morphohistochemistry of the integument of semi-engorged R. sanguineus s.l. females exposed to different carvacrol concentrations. The findings indicate that the integument surface of females exposed to the highest carvacrol concentration (25 µl/ml) became wrinkled, suggesting dehydration or the result of integument cuticular and epithelial layer disorganization in response to the toxic product. Morphohistochemical integument layer alterations were more significant and intense in females exposed to the highest carvacrol concentration (25 µl/ml), confirming dose-dependent carvacrol action. Among other cell and tissue alterations, changes in epithelial cell shape, size, and arrangement (epidermal layer) were noted, alongside altered and pyknotic-shaped nuclei, suggesting a death process for these cells. This epithelium changed from simple cubic to stratified, also in response to the presence of the evaluated bioactive compound. Thus, the findings reported herein demonstrate that carvacrol may be an alternative for an efficient and more sustainable tick control in the near future.