Stratum Spongiosum Research Articles

Study of Histological Skin Structure of Python reticulatus and Varanus salvator

Reptile skin is covered with scales that form a protective barrier, making it waterproof and enabling life on land. The present study investigated the histological structure of the skin of the Python reticulatus and Varanus salvator. The samples used were Python reticulatus and Varanus salvator skin taken from the dorsal region. Preparations were made using the hematoxylin eosin (HE) staining method which was carried out at the Microbiology of the leather processing technology, Politeknik ATK Yogyakarta. The results showed that the histological structure of Python reticulatus skin consisted of two layers, epidermis and dermis. The epidermis was composed of stratum corneum, stratum granulosum, and stratum basale. The dermis consists of an outer layer called the stratum laxum (stratum spongiosum) and an inner layer called the stratum compactum. Meanwhile, the histological skin structure of Varanus salvator skin consists of epidermis which included oberhautchen, α-keratin layer, β-keratin layer, supra basale layer, and basale layer. The dermis consists of superficial dermis and deep dermis. There are differences between Python reticulatus skin that is distinguished by its ability to ecydis (skin shedding) the epidermis and Varanus salvator skin have osteoderm (OD) within their dermis layer

Dexamethasone's effect on endometrial inflammatory response in jennies after artificial insemination with frozen donkey semen

Artificial insemination (AI) with frozen donkey semen leads to low fertility rates in jennies. This might be due to an exacerbation of the acute inflammatory endometrial response to frozen semen, as seen in mares with persistent post breeding endometritis. Higher pregnancy rates were obtained in these mares when treated with dexamethasone at breeding time. The aim of this study was to evaluate the effect of dexamethasone on endometrial inflammatory responses in jennies after AI with frozen donkey semen. This study was performed from August to December 2022 in Argentina. Six healthy jennies of proven fertility were included in a crossover experimental design. All animals passed through an estrous cycle with no treatment before crossover between treatments. Jennies were subjected to 1) no AI and no treatment in estrus (control, C); 2) AI with no treatment (D-); and 3) AI with administration of dexamethasone, 50 mg IV at AI time (D+). Post ovulation. deep AI was performed with frozen donkey semen (700 × 106 progressively motile sperm (PMS). Endometrial samples (cytology and biopsies) were taken at estrus and 24 hours post AI. Cytology smears were stained with Diff-Quick™; 200 cells were counted under an optical microscope (Nikon Eclipse™ NI-U) and the percentage (%) of polymorphonuclear neutrophils (PMN) and eosinophils was calculated.Endometrial biopsies were taken from the bifurcation of the uterine body, fixed in 10% buffered formalin prior to hematoxylin-eosin staining. Five fields were selected per sample at 400x and average cell counts were calculated. The effect of treatments on % PMN and % eosinophils in cytology and biopsies were evaluated by the Kruskal Wallis test followed by the Dunn test for multiple comparisons. Values are expressed as median and interquartile ranges. The cytology smears of all animals showed an inflammatory response to semen deposition. There were differences (P = 0.003) between % PMN in C [0.625 (0.50 - 0.94)] and the other two groups [D-: 35.00 (22.50 - 46.00); D+: 39.50 (28.63 - 40.25)]. No eosinophils were observed. The inflammatory pattern in biopsies showed a diffuse infiltration of PMN and eosinophils in the luminal epithelium, stratum compactum and stratum spongiosum. There were differences (P = 0.003) between % PMN in C [0.30 (0.05 - 0.40) and the other two groups [D-: 41.90 (28.60 - 43.50); D+: 28.70 (10.35 - 49.00)]. Eosinophils were different (P = 0.005) for the three groups [C: 0.40 (0.20 - 1.20); D-: 21.50 (11.35 - 60.60); D+: 4.60 (1.30 - 7.75)]. In conclusion, a single dose of dexamethasone at AI in jennies did not decrease endometrial PMN but decreased eosinophils 24 hours after insemination.

Influence of sperm viability on uterine leukocyte chemotaxis

The immune system can differentiate live from dead microorganisms, generating a response as necessary; there has been limited study of equine sperm. We aimed to compare the uterine cellular immune response to artificial insemination (AI) with live versus dead equine sperm. Twenty mares in estrus (follicles ≥ 35 mm, uterine edema), without intrauterine fluid or polymorphonuclear leukocytes (PMNs) were selected from a population of horses sent to an abattoir during the breeding season. Their average age was 10.8 ± 0.9 years (range 6 - 20), body condition score > 3 (scale 1 - 5), and they were clinically healthy. Mares were randomly allocated into two groups. Frozen semen, a pool from two stallions, was inseminated into the uterine body: either LIVE (n = 10), 3.0 mL of 900 × 106 sperm (≥ 35% progressive motility), or DEAD (n = 10), 3.0 mL of 900 × 106 sperm killed by snap freezing in liquid nitrogen. Four hours post AI, mares were slaughtered; ex vivo uteri were subjected to a low-volume lavage (LVL) with 50 mL of PBS and three endometrial tissue samples were collected (both uterine horns and uterine body). The fluid recovered was analyzed in a Neubauer chamber. Endometrial samples were processed for histologicalevaluation using bright-field microscopy. For each mare, the three uterine samples were pooled for analysis. The number of PMNs in the stratum compactum (SC) and spongiosum (SS) was counted in 5 fields per uterine sample at 400x magnification, totaling 15 fields/stratum/mare. Groups were considered independent factors. Leukocyte concentrations in the LVL and PMN presence in both strata were considered dependent factors. Leukocyte concentrations in the LVL were analyzed with a Mann-Whitney test (median ± IQR) and the number of PMNs per field of each stratum using a t-test (mean ± SEM). The significance level was defined as p ≤ 0.05. Mares in the DEAD group presented a lower concentration of leukocytes in the LVL than in the LIVE group (33.2 × 106/mL ± 62.6 versus 63.2 × 106/mL ± 56.5; p = 0.05). Correspondingly, the mean PMN number per field in the SC (50.5 ± 5.2/field versus 69.0 ± 5.3/field; p = 0.02) and SS (32.8 ± 6.2/field versus 54.4 ± 5.7/field; p = 0.02) of mares in the DEAD group were lower than mares in the LIVE group. In conclusion, dead sperm elicited a less intense inflammatory response 4 hours after AI compared to live sperm, suggesting that as with bacteria, the immune system may differentiate sperm according to viability.

A novel corporoplasty technique with a urethral plate flap in hypospadias repair.

To report a novel corporoplasty technique with a urethral plate flap in hypospadias repair and evaluate its safety and efficacy for ventral lengthening. Data were retrospectively collected from consecutive patients with hypospadias who underwent urethral plate flap corporoplasty between July 2021 and March 2022. All patients underwent hypospadias repair using the Duckett technique. The corporoplasty procedure involved the following key steps: the half-spongiosum of the urethral plate was harvested as a flap (with a pedicle attached to the corpus cavernosum); a transverse incision of the tunica albuginea was made adjacent to the pedicle; and the flap was patched onto the corporal defect. The study included 10 patients, with a median age of 20 months. The initial meatal location was penile in two patients, penoscrotal in four patients, and scrotal in four patients. The median ventral curvature was 45° after degloving and urethral plate transection. The median ventral lengthening distance proportional to penis length was 0.21. During the median follow-up of 13.8 months, complications occurred in three cases, including two cases of fistula and one case of urethral stricture with secondary diverticulum. No cases of recurrent ventral curvature, meatal stenosis, or urethral dehiscence were noted. Postoperative ultrasonography showed a good continuation of the tunica albuginea and integrity of the stratum spongiosum at the corporoplasty site. Urethral plate flap corporoplasty is a simple and effective ventral lengthening procedure. The novel corporoplasty technique allows for anatomical and architectural repair of corporal disproportion.

Piscine Orthoreovirus-1 (PRV-1) Has Been Present in Chilean Salmon Aquaculture since at Least 1994

Heart and skeletal muscle inflammation (HSMI) caused by Piscine orthoreovirus (PRV) was first described in farmed Atlantic salmon in Chile in 2011. However, as PRV induces long-lasting infections, it is not known when Chilean farmed salmon may have started to show PRV positivity. This study aimed to evaluate the presence/absence of PRV-1 in formalin-fixed, paraffin-embedded Atlantic salmon heart tissues (FFPE) cultured in Chile during 1992 and 1999. The most frequent histopathological findings in the 42 FFPE blocks were mild focal cardiomyocyte degeneration (57.1%) and a mild focal mononuclear inflammatory infiltrate (21.4%) in the ventricular stratum spongiosum of the heart. One of the 42 heart samples analyzed by RT-qPCR was positive for PRV-1 (2.4%). All samples were negative for other viral and bacterial pathogens that can induce similar histological changes in the heart. Taken together, our results show that PRV-1 has been present in Chile—as a low-virulence genogroup—since at least 1994, 17 years before the first HSMI outbreak in 2011. Finally, archaeovirology can be a valid alternative to contribute to the understanding of the epidemiology of diseases in aquaculture.

Ladies in armor: A micro-computed tomographic study of skin calcification in European toads (genus Bufo).

Micro-computed tomography is a powerful tool toward the detailed reconstruction of internal and external morphology, in particular for ossified and other dense tissues. Here, we document and compare the level of calcification in the skin of the head and the parotoids (the external skin glands) in males and females of common and spined toads, Bufo bufo and B. spinosus. In some anurans, including Bufo species, a specific acellular calcified tissue layer within the dermis has been documented (the Eberth-Katschenko, or EK-layer). By a combination of micro-computed tomography and classical histology, we detected additional calcium deposits located in the dermal layer stratum spongiosum, positioned above the EK-layer. We showed that the level of calcification and the presence of additional calcium deposits are size and sex related, increasing in the order B. bufo males, B. spinosus males, B. bufo females to B. spinosus females. The last of these groups is the least variable. Bufo spinosus females have dense calcium deposits in the parotoids and the dorsal and ventral skin. Three-dimensional volume renderings and cross-sectional slices obtained by micro-CT scanning indicate that this approach is a promising technique for further studies on bufonid skin anatomy and geographic variation in skin calcification.

Phosphate, calcium, and vitamin D signaling, transport, and metabolism in the endometria of cyclic ewes

BackgroundRecent evidence suggests important roles for progesterone (P4) and interferon tau in the regulation of calcium, phosphate, and vitamin D signaling in the uteri of pregnant sheep. However, the effects of P4 and estradiol (E2), with respect to the expression of their receptors PGR and ESR1, respectively, in uterine epithelia on mineral signaling during the estrous cycle has not been investigated. Estrous cycles of mature Suffolk ewes were synchronized, prostaglandin F2α was administered, and ewes were observed for estrus (designated as Day 0) in the presence of vasectomized rams. On Days 1, 9, or 14 of the estrous cycle, hysterectomies were performed.Results25-hydroxyvitamin D was more abundant in plasma from ewes on Day 14 than Day 1 (P < 0.05). Expression of fibroblast growth factor receptor 2 (FGFR2), a disintegrin and metalloprotease 17 (ADAM17), and parathyroid hormone-related protein (PTHrP) mRNAs was greater in endometria on Day 9 compared to Days 1 and 14 (P < 0.01). Similarly, expression of transient receptor potential cation channel subfamily V member 6 (TRPV6) mRNA was greater in endometria on Day 9 than Day 1 (P < 0.05). ATPase plasma membrane Ca2+ transporting 4 (ATP2B4) and S100 calcium binding protein G (S100G) mRNA expression was greater in endometria on Day 14 than on Days 1 and 9 (P < 0.01). In contrast, endometrial expression of vitamin D receptor (VDR) mRNA was lower on Days 9 and 14 than Day 1 (P < 0.01). Expression of klotho (KL) (P < 0.05) and cytochrome P450 family 24 subfamily A member 1 (CYP24) (P < 0.01) mRNAs was lower on Day 14 than Days 1 and 9. ADAM17, FGF23, CYP2R1, CYP27B1, KL, and VDR proteins immunolocalized to the uterine myometrium, blood vessels, and uterine luminal (LE), superficial glandular (sGE), and glandular (GE) epithelia. S100A9 protein was weakly expressed in the uterine myometrium, LE, sGE, and GE. Immunoreactivity of CYP2R1 and KL proteins in uterine LE and sGE was less on Day 1 than on Days 9 and 14. In contrast, S100G protein was expressed exclusively by GE, and immunoreactive S100G protein was less on Day 9. S100A12 protein localized to stromal cells of the uterine stratum spongiosum and blood vessels, but not by uterine epithelial cells.ConclusionCollectively, these results implicate E2, P4, and PGR in the regulation of phosphate, calcium, and vitamin D signaling in cyclic ewes.

Observations on Red Mark Syndrome in juvenile rainbow trout farmed in RAS system.

Observations on Red Mark Syndrome in juvenile rainbow trout farmed in RAS system.

Histological and Ultrastructural Description of Benign Adipocytic Tumors in Farmed Striped Sea Bream (Lythognathus mormyrus).

Simple SummaryMesenchymal neoplasms of the skin are common tumors in domestic animals and often reported in fish pathology. Among them, lipomas are frequently observed, but the definition of their different histological features and their classification in fish are still in their primordial stages. In the present work, the authors describe different type of lipomas found in a wild stock of striped seabream and outline their key differential microscopical features. Two new types of lipoma never observed in fish pathology, defined as spindle cell lipoma and atypical spindle cell-like lipoma, are reported.Cutaneous neoplasms affecting wild striped bream (Lythognathus mormyrus) have been recorded after their introduction in a marine aquaculture farm in the Adriatic Sea. The tumors were evident on 24% of the reared fish, showing single or multiple nodules, with a diameter ranging between 0.5–4.0 cm. Histologically, all the neoplastic lesions were located in the stratum spongiosum of the dermis and were surrounded by a thin capsule of connective tissue. The tumors were predominantly composed of adipocytes grouped and surrounded by a thin net of fibroblasts and collagen fibers. In some lipomas a mixture of adipocytes and uniform spindle cells were also observed. Fibroblasts and collagen fibers, or spindle cells, showing few mitotic figures were mainly observed in other nodules. Three of the tumors showed bands of cells with elongated nuclei. Five neoplasms differed from the classic spindle cell lipoma due to the presence of scattered giant cells. These cells presented acidophilic abundant cytoplasm with multiple hyperchromatic nuclei showing a concentric “floret-like” arrangement. The tumors were further characterized by ultrastructural observations that allowed ruling out the presence of virus-like particles within the lesions. Histological features of the masses lead to the identification of four prevalent patterns of neoplasms: lipoma, fibrolipoma, spindle cell lipoma (SCL), and atypical spindle cell-like lipoma (ASCL). The different neoplasms could arise from the transformation of mesenchymal cells of dermal origin. To the author’s knowledge, this is the first report describing key differential histological and ultrastructural features of these neoplasms in striped sea bream.

Histological structure of striped catfish (Pangasius Hypophthalmus) skin from different body size (age) and its relation to the quality of gelatin based on the melting point

Gelatin is a protein derived from collagen denaturation. Currently, fish gelatin has been developed as an alternative to halal gelatin. Fish gelatin can be extracted from the skin of several fish including striped catfish (Pangasius hypophthalmus), because the skin’s connective tissue contains a lot of collagen. In industrial applications, melting point is a very important characteristic of gelatin. The biological factors of raw materials such as the size or age of fish are thought to influence the content of collagen, thereby affecting the melting point of gelatin. The aim of this study was to compare the histological structure of the striped catfish skin at different body sizes, especially the observation of collagen in the skin’s connective tissues and to determine its relationship with the quality of its gelatin product based on melting point. The gelatin pre-treatment was performed using acid-base treatment, extraction with distilled water (55°C) were conducted prior to melting point measurement. The results of histological analysis showed that the connective tissue in the skin of larger fish contained thicker stratum compactum and thinner of stratum spongiosum. The melting point of large catfish skin gelatin has a higher melting point (25.5 °C) than the smaller size (24 °C).

Половая изменчивость гистологических параметров кожи сибирского углозуба, Salamandrella keyserlingii (Amphibia, Caudata), в воднуюи наземнуюфазы сезонного цикла

Histological features of the dorsal (DS), throat (TS) and tail skins (caudal skin, CS) were examined in Salamandrella keyserlingii females of the aquatic and terrestrial morphotypes. Using histological and statistical methods, sexual differences in the relative areas of epidermis, strata compactum and spongiosum, connective tissue in the whole, granular and mucous glands were measured. In the aquatic phase, males, in comparison with females, have larger areas of the connective tissue in TS and DS, a larger area of the epidermis in CS, but smaller areas of the granular glands in the upper part of CS and elements of the connective tissue in the lower part of CS. In the terrestrial phase, sexual differences were weakly expressed. Females, in comparison with males, have larger areas of the connective tissue in the whole and its stratum spongiosum in the upper part of CS. Elements of the connective tissue made the greatest contribution to the formation of sexual differences of the skin in S. keyselingii.

A new species of Myxobolus Bütschli, 1882 (Bivalvulida: Myxobolidae) infecting stratum spongiosum of the imperiled sicklefin redhorse, Moxostoma sp. (Cypriniformes: Catostomidae) from the Little Tennessee River, North Carolina, USA.

The sicklefin redhorse, Moxostoma sp. (Cypriniformes: Catostomidae), is an innominate imperiled catostomid endemic to the Hiwassee and Little Tennessee river basins, which has been restricted to a few tributaries of these systems by impoundments. During collections to propagate sicklefin redhorse for reintroduction, a myxozoan, described herein, was observed infecting sicklefin redhorse in the Little Tennessee River Basin, North Carolina. Myxobolus naylori Ksepka et Bullard sp. n. infects the stratum spongiosum covering the scales of sicklefin redhorse. Myxospores of the new species differ from all congeners by the combination of having a mucous envelope, intercapsular process, and sutural markings as well as lacking an iodinophilic vacuole in the sporoplasm. A phylogenetic analysis of the 18S rDNA gene recovered the new species in a polytomy with Myxobolus marumotoi Li et Sato, 2014 and a clade comprised of species of Myxobolus Bütschli, 1882; Thelohanellus Kudo, 1933, and Dicauda Hoffman et Walker, 1973. Histological sections of infected sicklefin redhorse skin revealed myxospores within a plasmodium in the stratum spongiosum dorsal to scales, encapsulated in collagen fibres, and associated with focal erosion of scales directly beneath the plasmodium; in some instances, the scale was perforated by the plasmodium. The specificity of the new species to sicklefin redhorse may make it a useful biological tag to differentiate sicklefin redhorse from morphologically similar species. The new species is the first parasite reported from sicklefin redhorse, a species of concern to the United States Fish and Wildlife Service. No species of Myxobolus has been reported from species of Moxostoma in the Southeast United States. As it was observed that Myxobolus minutus Rosser, Griffin, Quiniou, Alberson, Woodyard, Mischker, Greenway, Wise et Pote, 2016 is a primary junior homonym of Myxobolus minutus Nemeczek, 1911, we propose the replacement name Myxobolus diminutus (Rosser, Griffin, Quiniou, Alberson, Woodyard, Mischker, Greenway, Wise et Pote, 2016).

Skin infection of greater amberjack (Seriola dumerili) by monogenean ectoparasite neobenedenia girellae: A morphological and histopathological descriptive study

Neobenedenia girellae is considered an epizootic infection for intensively cultured fish species. Particularly, for greater amberjack (Seriola dumerili) N. girellae causes high mortality rates and supposes a bottleneck during its on-growing period. Thus, the objective of this work was to describe the skin morphological alterations caused by a N. girellae infection on greater amberjack. Greater amberjack juveniles were sampled pre and post experimental infection with N. girellae obtaining cranial and dorsal skin samples. Samples were processed for morphological and ultrastructural studies and revealed clear differences in the structure of both regions, confirming the cranial region as the most susceptible region to be parasitized due to an absence of scales and lower goblet cells density. N. girellae adhesion disrupted the structure of epidermal epithelial cells by overpressure. Stratum spongiosum surface-epithelial cells located near the parasite presented a clear cell degradation process, associated in some cases with cellular detachment. N. girellae infection induced epidermal hydropic degeneration and, in some cases, focal spongiosis. Tissue ulcerative lesions caused by the parasite’s attachment structures were characterized by a specific mobilization of leucocytes to the fixation areas. Thus, N.girellae induces important alterations in greater amberjack epidermis independently of the skin region that explain the appearance of secondary infections and associated mortalities.

IgM+ and IgT+ B Cell Traffic to the Heart during SAV Infection in Atlantic Salmon.

B cells of teleost fish differentiate in the head kidney, and spleen, and either remain in the lymphatic organs or move to the blood and peripheral tissues. There is limited knowledge about piscine B cell traffic to sites of vaccination and infection and their functional roles at these sites. In this work, we examined the traffic of B cells in Atlantic salmon challenged with salmonid alphavirus (SAV). In situ hybridization (RNAScope) showed increased numbers of immunoglobin (Ig)M+ and IgT+ B cells in the heart in response to SAV challenge, with IgM+ B cells being most abundant. An increase in IgT+ B cells was also evident, indicating a role of IgT+ B cells in nonmucosal tissues and systemic viral infections. After infection, B cells were mainly found in the stratum spongiosum of the cardiac ventricle, colocalizing with virus-infected myocardial-like cells. From sequencing the variable region of IgM in the main target organ (heart) and comparing it with a major lymphatic organ (the spleen), co-occurrence in antibody repertoires indicated a transfer of B cells from the spleen to the heart, as well as earlier recruitment of B cells to the heart in vaccinated fish compared to those that were unvaccinated. Transcriptome analyses performed at 21 days post-challenge suggested higher expression of multiple mediators of inflammation and lymphocyte-specific genes in unvaccinated compared to vaccinated fish, in parallel with a massive suppression of genes involved in heart contraction, metabolism, and development of tissue. The adaptive responses to SAV in vaccinated salmon appeared to alleviate the disease. Altogether, these results suggest that migration of B cells from lymphatic organs to sites of infection is an important part of the adaptive immune response of Atlantic salmon to SAV.

Inhibiting fibroblast aggregation in skin wounds unlocks developmental pathway to regeneration

Salamanders are capable of full-thickness skin regeneration where removal of epidermis, dermis and hypodermis results in scar-free repair. What remains unclear is whether regeneration of these tissues recapitulates the cellular events of skin development or occurs through a process unique to regenerative healing. Unfortunately, information on the post-embryonic development of salamander skin is severely lacking, having focused on compartments or cell types, but never on the skin as a complete organ. By examining coordinated development of the epidermis and dermis in axolotls we establish six distinct stages of skin development (I-VI): I–V for normally paedomorphic adults and a sixth stage following metamorphosis. Raising animals either in isolation (zero density pressure) or in groups (density pressure) we find that skin development progresses as a function of animal size and that density directly effects developmental rate. Using keratins, p63, and proliferative markers, we show that when the dermis transforms into the stratum spongiosum and stratum compactum, keratinocytes differentiate into at least three distinct phenotypes that reveal a cryptic stratification program uncoupled from metamorphosis. Lastly, comparing skin regeneration to skin development, we find that dermal regeneration occurs through a unique process, relying heavily on remodeling of the wound extracellular matrix, rather than proceeding through direct development of a dermal lamella produced by the epidermis. By preventing fibroblast influx into the wound bed using beryllium nitrate, we show that in the absence of fibroblast generated ECM production skin regeneration occurs through an alternate route that recapitulates development.

Follicle Deviation in Miniature Mares

Endometritis constitutes a major problem in the management of broodmares; hence, diagnostic tests with a high sensitivity and specificity are highly appreciated. The aim of this study was to compare the results from endometrial, cytologic, and bacteriologic examinations obtained by a newly developed, double-guarded, flushing technique versus standard diagnostic tests, the double-guarded swab and biopsy. The described double-guarded flush technique requires the use of a disposable uterine flushing tube, a sanitary sleeve, a sterile steel speculum, and a 250 mL fluid bag. Endometrial biopsies, swabs, and low-volume lavage samples were obtained from 34 research mares at six different time points in four estrous cycles and were evaluated cytologically and bacteriologically. Endometrial biopsies from the first cycle (n = 34) were examined for the presence of polymorphonuclear neutrophils (PMNs) in the stratum compactum and stratum spongiosum and used as a gold standard for calculation of diagnostic sensitivity and specificity. In all samples, Escherichia coli was most frequently isolated (lavage, 30%; swab, 21%; and biopsy, 12%) followed by β-hemolytic streptococci (lavage, 11%; swab, 8%; and biopsy, 7%). Positive cytology was less likely to occur when E coli was isolated from the diagnostic tests compared with the growth of β-hemolytic streptococci. Isolation of pathogens from uterine samples was highly associated with the presence of PMNs in the stratum compactum and straum spongiosum on histology. Using the presence of PMNs in the tissue specimens as the gold standard for diagnosing endometritis, the sensitivity of low-volume lavage culture was 0.75 and the specificity was 0.72. In conclusion, the double-guarded, low-volume, lavage technique was a rapid and accurate method for diagnosing mares with endometritis, and the risk of false-positive samples is considered to be minimal compared with other flushing techniques described.

Progesterone and 5α-dihydroprogesterone (DHP) in Cyclic Mares, and in Ovariectomized Mares and Geldings After Progesterone Administration

Endometritis constitutes a major problem in the management of broodmares; hence, diagnostic tests with a high sensitivity and specificity are highly appreciated. The aim of this study was to compare the results from endometrial, cytologic, and bacteriologic examinations obtained by a newly developed, double-guarded, flushing technique versus standard diagnostic tests, the double-guarded swab and biopsy. The described double-guarded flush technique requires the use of a disposable uterine flushing tube, a sanitary sleeve, a sterile steel speculum, and a 250 mL fluid bag. Endometrial biopsies, swabs, and low-volume lavage samples were obtained from 34 research mares at six different time points in four estrous cycles and were evaluated cytologically and bacteriologically. Endometrial biopsies from the first cycle (n = 34) were examined for the presence of polymorphonuclear neutrophils (PMNs) in the stratum compactum and stratum spongiosum and used as a gold standard for calculation of diagnostic sensitivity and specificity. In all samples, Escherichia coli was most frequently isolated (lavage, 30%; swab, 21%; and biopsy, 12%) followed by β-hemolytic streptococci (lavage, 11%; swab, 8%; and biopsy, 7%). Positive cytology was less likely to occur when E coli was isolated from the diagnostic tests compared with the growth of β-hemolytic streptococci. Isolation of pathogens from uterine samples was highly associated with the presence of PMNs in the stratum compactum and straum spongiosum on histology. Using the presence of PMNs in the tissue specimens as the gold standard for diagnosing endometritis, the sensitivity of low-volume lavage culture was 0.75 and the specificity was 0.72. In conclusion, the double-guarded, low-volume, lavage technique was a rapid and accurate method for diagnosing mares with endometritis, and the risk of false-positive samples is considered to be minimal compared with other flushing techniques described.

Skin Development in H. huso Larvae

Introduction Fish skin is important for life and protection mechanisms. Sturgeon skin also has an economical potential for its leather. Materials and Methods This article is a light microscopy study for knowledge the development of epidermis and dermis in one species of sturgeon (Huso. huso). The fishes from different days of week-1 to week-6 were caught from Shahid Marjani propagation center and were processed. Results From 1(dph) the epidermis as two layers and dermis as a very thin collagen layer had formed. Sensory buds in epidermis and chromatophore cells in dermis of head and also arranged the dermal endothelial cells were features of 3 (dph). At 10 (dph) there was an increase in epidermal cell line, existence the circular cells as club cells in epidermis and increase in dermal thickness observed. From the character of 20 (dph) was organized epidermis to three layers and collagen fibrils as parallel to body. From 25- 40 (dph) an increase in cell lines of epidermis up to 10 rows in some areas was observed. Conclusion The most important changes were the events occurred in dermis. The self-organized collagen fibrils to several lamellae, invading the fibroblasts to derm and forms of stratum campactum and stratum spongiosum.

Myxobolus pseudowulii sp. n. (Myxozoa: Myxosporea), a new skin parasite of yellow catfish Tachysurus fulvidraco (Richardson) and redescription of Myxobolus voremkhai (Akhmerov, 1960).

Two species of Myxobolus Bütschli, 1882 were found in yellow catfish Tachysurus fulvidraco (Richardson). A species of Myxobolus infecting the gills was morphologically identified as Myxobolus voremkhai (Akhmerov, 1960) and it was characterised here with additional morphological and molecular data. The other species of Myxobolus infecting the host's skin did not conform to any known myxosporean species. It is characterised by the presence of round, black or milky white plasmodia with black spots. Myxospores are pyriform in frontal view and lemon-shaped in lateral view, measuring 12.9-16.2 μm (14.6 ± 0.7 μm) in length, 8.1-10.8 μm (9.4 ± 0.5 μm) in width, and 6.1-8.1 μm (7.0 ± 0.4 μm) in thickness. Two ampullaceous polar capsules are slightly unequal in size, larger polar capsule 7.2-9.5 μm (7.9 ± 0.4 μm) long by 3.0-3.9 μm (3.5 ± 0.2 μm) wide, smaller capsule 6.9-8.0 μm (7.4 ± 0.3 μm) long by 2.9-3.9 μm (3.4 ± 0.2 μm) wide. Polar filaments are coiled with seven to nine turns. Histologically, the plasmodia develop in the stratum spongiosum of skin dermis, resulting in epithelial cell shedding and immunological cell infiltration. Given the morphological and molecular differences between this species and other species of Myxobolus, we proposed the name of Myxobolus pseudowulii sp. n. for this parasite from the skin of yellow catfish. Interestingly, some spores of the new species possess Henneguya-like caudal appendages. Phylogenetically, M. pseudowulii sp. n. and M. voremkhai infecting yellow catfish group together in one clade with other parasites of Siluriformes, indicating that parasites clustering according to the fish host order may be an important factor affecting the evolution of species within the Myxobolus clade.

Morphometric Variations in the Skin Layers of Frogs: An Exploration Into Their Relation With Ecological Parameters in Leptodactylus (Anura, Leptodactylidae), With an Emphasis on the Eberth-Kastschenko Layer.

Leptodactylus is a genus of frogs known to live in diverse habitats and to show both aquatic and terrestrial breeding habits. We studied 21 species of Leptodactylus to explore whether skin structure specialization relates to habitats and habit variation. Morphometric analyses of the skin thickness revealed that phylogeny has a strong influence on variations in the thickness of the epidermis, stratum spongiosum, Eberth-Kastschenko layer, and stratum compactum, while habitat and habits display no significant correlation. The optimization of the phylogenetic hypothesis suggested that a pattern of intermediate values for skin layer thickness are plesiomorphic for this group. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1895-1909, 2017. © 2017 Wiley Periodicals, Inc.