Morphological and pathological changes of Eustachian tube mucosa in an animal model of eosinophilic otitis media.

INTRODUCTION: Eosinophilic otitis media is an intractable otitis media and a fairly common middle ear disease. However, the pathogenesis of eosinophilic otitis media is obscure. OBJECTIVE: To observe the pathological and ultrastructural changes of the Eustachian tube mucosal epithelium in rats with eosinophilic otitis media and further explore the pathogenesis of eosinophilic otitis media. METHODS: Animals were intraperitoneally injected with 2000 mg ovalbumin and 100 mg aluminum hydroxide (alum) on day 0, followed by 100 mg ovalbumin and 100 mg alum injection on days 7 and 14. Next they were topically boosted by daily application of 100 mg ovalbumin solution via nasal drip and intratympanic injection of 0.1 mL ovalbumin (1000 mg/mL) in the right ear (group A, n = 80) and 0.1 mL saline in the left ear as control (group B, n = 80) starting on day 21 and continuing for 14 days. The temporal bones were dissected on the 35th, 38th, 41st and 43rd day separately under anesthesia. Scanning electron microscopy, hematoxylin-eosin and toluidine blue staining were used to observe the pathological and morphological changes of Eustachian tube mucosa stained samples. Moreover, inflammatory cells and cilia were counted. RESULTS: The epithelium of the Eustachian tube in group A was swollen and thickened. The cilia were arranged in a disorderly manner and partially detached. Eosinophils infiltrated the submucosal layer of the Eustachian tube, and their number increased significantly compared with that in group B (p < 0.05). Simultaneously, mast cell degranulation was observed in group A. Scanning electron microscopy revealed that the cilia were lodged and gathered along the whole length of Eustachian tube in group A. Ciliated cell density was significantly lower than that in Group B (p < 0.01). CONCLUSION: In the eosinophilic otitis media model, allergy caused significant changes in pathology and morphology of the Eustachian tube mucosa, affecting the normal function of the Eustachian tube which played an important role in the occurrence and development of eosinophilic otitis media.

The structure of the skin, types and distribution of mucous cell of yangtze sturgeon ( Acipenser dabryanus ) / La estructura de la piel, los tipos y distribución de las células mucosas del esturión yangtze ( Acipenser dabryanus )

The structural characteristics of the skin, types and distribution of mucous cells of Yangtze sturgeon (Acipenser dabryanus) were studied at the light microscope level, stained with Haematoxylin-eosin (HE) and Alcian blue-periodie acid Schiff (ABPAS). The skin of both was composed of epidermis and dermis. The dermis was divided into stratum spongiosum and stratum compactum. The stained color of stratum compactum was stained more deeply than that of stratum spongiosum. The skin thickness displayed differences in the fish at different body positions. The thickest of epidermis layer was on the dorsal region for Yangtze sturgeon, reversely, the thinnest was the mandibular region; Stratum spongiosum on the mandibular region was the thickest, the stratum spongiosum of the maxillary region was not obvious. In summary, keratinized spines, a kind of keratin derivative, are widely distributed in the mandibular, ventral, dorsal, and caudal peduncle skin surface for Yangtze sturgeon, and some pit organs mainly present in the skin surface of the maxillary and ventral regions. In short, the small amount of mucous cells in the skin of Yangtze sturgeon and the type of mucous cell were main Type IV, nevertheless there was a distribution of a few Type III.

Se estudiaron las características estructurales de la piel, los tipos y la distribución de las células mucosas del esturión Yangtze (Acipenser dabryanus) con microscopio de luz, teñidas con hematoxilina-eosina (HE) y azul alcián-ácido de Schiff (AB-PAS). La piel estaba compuesta por epidermis y dermis. La dermis se dividía en estrato esponjoso y estrato compacto. El grosor de la piel mostró diferencias en los peces en diferentes posiciones del cuerpo. La capa más gruesa de la epidermis se observó en la región dorsal del esturión Yangtze; a la inversa, la más delgada en la región mandibular. El estrato esponjoso en la región mandibular era el más grueso, el estrato esponjoso de la región maxilar no era visualizado. En resumen, las espinas queratinizadas, un tipo derivado de la queratina, estaban ampliamente distribuidas en la superficie de la piel del pedúnculo mandibular, ventral, dorsal y caudal en el esturión Yangtze, y algunos órganos en fosas, presentes principalmente en la superficie de la piel de las regiones mandibular y ventral. En resumen, la pequeña cantidad de células mucosas en la piel del esturión Yangtze y el tipo de célula mucosa eran células principales tipo IV, sin embargo, se observaron algunas células tipo III.

Lactococcus lactis carrying the pValac eukaryotic expression vector coding for IL-4 reduces chemically-induced intestinal inflammation by increasing the levels of IL-10-producing regulatory cells.

BACKGROUND: Inflammatory bowel diseases are characterized by chronic intestinal inflammation that leads to severe destruction of the intestinal mucosa. Therefore, the understanding of their aetiology as well as the development of new medicines is an important step for the treatment of such diseases. Consequently, the development of Lactococcus lactis strains capable of delivering a eukaryotic expression vector encoding the interleukin 4 (IL-4) of Mus musculus would represent a new strategy for the elaboration of a more effective alternative therapy against Crohn's disease. RESULTS: The murine IL-4 ORF was cloned into the eukaryotic expression vector pValac::dts. The resulting plasmid-pValac::dts::IL-4-was transfected into CHO cells so that its functionality could be evaluated in vitro. With fluorescent confocal microscopy, flow cytometry and ELISA, it was observed that pValac::dts::IL-4-transfected cells produced IL-4, while non-transfected cells and cells transfected with the empty vector did not. Then, pValac::dts::IL-4 was inserted into L. lactis MG1363 FnBPA(+) in order to evaluate the therapeutic potential of the recombinant strain against TNBS-induced colitis. Intragastric administration of L. lactis MG1363 FnBPA(+) (pValac::dts::IL-4) was able to decrease the severity of colitis, with animals showing decreased levels of IL-12, IL-6 and MPO activity; and increased levels of IL-4 and IL-10. Finally, LP-isolated cells from mice administered TNBS were immunophenotyped so that the main IL-4 and IL-10 producers were identified. Mice administered the recombinant strain presented significantly higher percentages of F4/80(+)MHCII(+)Ly6C(-)IL-4(+), F4/80(+)MHCII(+)Ly6C(-)IL-10(+), F4/80(+)MHCII(+)Ly6C(-)CD206(+)CD124(+)IL-10(+) and CD4(+)Foxp3(+)IL10(+) cells compared to the other groups. CONCLUSIONS: This study shows that L. lactis MG1363 FnBPA(+) (pValac::dts::IL-4) is a good candidate to maintain the anti-inflammatory and proinflammatory balance in the gastrointestinal tract, increasing the levels of IL-10-secreting regulatory cells and, thus, demonstrating the effectiveness of this novel DNA delivery-based strategy.

Morphology of mucosa-associated lymphoid tissue in odontocetes.

This study describes the mucosa-associated lymphoid tissue (MALT) in odontocetes from the Brazilian coast and freshwater systems. Seven species were evaluated and tissue samples were analyzed by light, scanning and transmission electron microscopy, and immunohistochemistry. Laryngeal tonsil was a palpable oval mass located in the larynx, composed of a lymphoepithelial complex. Dense collections of lymphocytes were found in the skin of male fetus and calf. Clusters of lymphoid tissue were found in the uterine cervix of a reproductively active juvenile female and along the pulmonary artery of an adult female. Lymphoid tissues associated with the gastrointestinal tract were characterized by diffusely arranged or organized lymphocytes. The anal tonsil was composed of an aggregate of lymphoid tissue occurring exclusively in the anal canal, being composed of squamous epithelium branches. MALT was present in different tissues and organic systems of cetaceans, providing constant protection against mucosal pathogens present in their environment.

Apoptosis and reduced microvascular density of the lamina propria during tooth eruption in rats.

During tooth eruption, structural and functional changes must occur in the lamina propria to establish the eruptive pathway. In this study, we evaluate the structural changes that occur during lamina propria degradation and focus these efforts on apoptosis and microvascular density. Fragments of maxilla containing the first molars from 9-, 11-, 13- and 16-day-old rats were fixed, decalcified and embedded in paraffin. The immunohistochemical detection of vascular endothelial growth factor (VEGF), caspase-3 and MAC387 (macrophage marker), and the TUNEL method were applied to the histological molar sections. The numerical density of TUNEL-positive cells and VEGF-positive blood vessel profiles were also obtained. Data were statistically evaluated using a one-way anova with the post-hoc Kruskal-Wallis or Tukey test and a significance level of P ≤ 0.05. Fragments of maxilla were embedded in Araldite for analysis under transmission electron microscopy (TEM). TUNEL-positive structures, fibroblasts with strongly basophilic nuclei and macrophages were observed in the lamina propria at all ages. Using TEM, we identified processes of fibroblasts or macrophages surrounding partially apoptotic cells. We found a high number of apoptotic cells in 11-, 13- and 16-day-old rats. We observed VEGF-positive blood vessel profiles at all ages, but a significant decrease in the numerical density was found in 13- and 16-day-old rats compared with 9-day-old rats. Therefore, the establishment of the eruptive pathway during the mucosal penetration stage depends on cell death by apoptosis, the phagocytic activity of fibroblasts and macrophages, and a decrease in the microvasculature due to vascular cell death. These data point to the importance of vascular rearrangement and vascular neoformation during tooth eruption and the development of oral mucosa.

The intricate role of mast cell proteases and the annexin A1-FPR1 system in abdominal wall endometriosis.

Endometriosis is a continuous and progressive disease with a poorly understood aetiology, pathophysiology and natural history. This study evaluated the histological differences between eutopic and ectopic endometria (abdominal wall endometriosis) and the expression of mast cell proteases (tryptase and chymase), annexin A1 (ANXA1) and formyl peptide receptor 1 (FPR1). Ectopic endometrium from 18 women with abdominal wall endometriosis and eutopic endometrium from 10 women without endometriosis were obtained. The endometrial samples were analysed by histopathology, immunohistochemistry and ultrastructural immunogold labeling to determine mast cell heterogeneity (tryptase and chymase positive cells) and the expression levels of ANXA1 and FPR1. Histopathological analysis of the endometriotic lesions showed a glandular pattern of mixed differentiation and an undifferentiated morphology with a significant influx of inflammatory cells and a change in mast cell heterogeneity, as evidenced by a significant increase in the number of chymase-positive cells and endogenous chymase expression. The undifferentiated glandular pattern of endometriotic lesions was positively associated with a marked increase and co-localization of ANXA1 and FPR1 in the epithelial cells. In conclusion, the co-upregulated expression of mast cell chymase and ANXA1-FPR1 system in ectopic endometrium suggests their involvement in the development of endometriotic lesions.

Ultrastructure of the oviductal mucosa of Leptodactylus chaquensis. Analysis of the preovulatory and postovulatory periods.

In the present study we analysed the ultrastructural characteristics of the oviductal mucosa of Leptodactylus chaquensis during the preovulatory period and immediately after ovulation. Epithelial secretory cells, ciliated cells, basal cells and glandular secretory cells are described. During the preovulatory period, the oviduct exhibits its maximum degree of development at both the epithelial and the glandular levels, with numerous secretory cells that contain a large number of secretory granules whose contents are released into the oviductal lumen by apocrine and exocytotic secretory processes. The secretory cells present throughout the oviduct display considerable variability in the characteristics of their secretory granules, which show different shapes, sizes, organization of the material contained and electron density. The different cell types are distributed following a characteristic pattern for each oviductal zone, thus creating an ultrastructural mosaic along the oviduct. During the postovulatory period, the number of secretory cells decreases and the remaining ones exhibit a marked reduction in secretory granules. Ciliated cells show a typical ultrastructural organization that is not modified throughout the reproductive cycle. Basal cells, located at the basal region of the epithelium, are characterized by their heterochromatic nuclei and electron-lucent cytoplasm, while glandular secretory cells exhibit oval, round or polyhedric granules, most of them with a prominent core. Our results, which indicate a high heterogeneity of secretory cell contents, allow us to suggest differential synthesis and secretion of specific products in each oviductal zone.

Seasonal morphological variations and age-related changes of the seminal vesicle of viscacha (Lagostomus maximus maximus): an ultrastructural and immunohistochemical study.

The viscacha is a seasonal rodent that exhibit an annual reproductive cycle with periods of maximum reproductive activity and gonadal regression. We studied seasonal variations in the morphology and cellular population of the seminal vesicles (SVs) during both periods and in impuber animals. Seminal vesicles were studied by light and electronic microscopy. Measurements of epithelial height, nuclear diameter, luminal diameter, and muscular layer were performed. Also, we studied the distribution of androgen receptors (AR) in this gland during the reproductive cycle and in impuber animal. During gonadal regression, principal and clear cells showed signs of reduced functional activity. These were characterized by an epithelium of smaller height, irregular nuclei, and cytoplasm with few organelles, dilated cisterns, and glycogen granules. In impuber animals, the principal cells showed large nuclei with chromatin lax and cytoplasm with small mitochondria, poorly developed Golgi apparatus, and granules of glycogen. On the other hand, the cells exhibited seasonal variations in the distribution and percentage of immunolabeled cells to AR throughout the annual reproductive cycle. During the gonadal regression period, glandular mucosa exhibited numerous epithelial cells with intense nuclear staining. However, fibromuscular stromal cells were weakly positive for AR in contrast to what was observed during the activity period. Considering that testosterone values are lower in adult animals during the period of gonadal regression and in impuber animals, our immunohistochemical results show a significant correlation with the percentage of AR-immunopositive cells. In conclusion, these results demonstrate that the structure of the SVs changes in the activity period of viscacha, probably because of elevated levels of testosterone leading to an increase in the secretory activity of epithelial cells.

[Lipoid proteinosis of Urbach-Wiethe: a case report]. / Lipóido-proteinose de Urbach Wiethe: Relato de caso.

Lipoid proteinosis or Urbach-Wiethe disease is a rare autosomal recessive mucocutaneous disorder caused by mutation in the EMC1 gene. Hoarseness is observed in early childhood associated with infiltration and thickening of skin. Multiple systemic manifestations develop involving mucosal deposition of hyalin material. We describe a 12-year-old boy with typical manifestations: a hoarse voice, thick skin with yellowish papules, including the typical disposition on the margin of the eyelids, infiltration of the tongue and lips, and varicella-like scars. Histopathological examination revealed deposition of hyaline substance with PAS-positive diastase-resistance at the dermoepidermal junction and around vessels. Ultrastructural study showed considerable thickening of the basal lamina of vessels besides the intense deposition of amorphous material in the dermis. Genetic analysis was not available.

The presence of a vocal ligament in fetuses: a histochemical and ultrastructural study.

Although it is currently believed that the vocal ligament of humans undergoes considerable development postnatally, there is no consensus as to the age at which it first emerges. In the newborn infant, the lamina propria has been described as containing a sparse collection of relatively unorganized fibres. In this study we obtained larynges from autopsy of human fetuses aged 7-9 months and used light and electron microscopy to study the collagenous and elastic system fibres in the lamina propria of the vocal fold. Collagen fibres were viewed using the Picrosirius polarization method and elastic system fibres were stained using Weigert's resorcin-fuchsin after oxidation with oxone. The histochemical and electron microscopic observations were consistent, showing collagen populations with an asymmetric distribution across different compartments of the lamina propria. In the central region, the collagen appeared as thin, weakly birefringent, greenish fibres when viewed using the Picrosirius polarization method, whereas the superficial and deep regions contained thick collagen fibres that displayed a strong red or yellow birefringence. These findings suggest that the thin fibres in the central region consist mainly of type III collagen, whereas type I collagen predominates in the superficial and deep regions, as has been reported in studies of adult vocal folds. Similarly, elastic system fibres showed a differential distribution throughout the lamina propria. Their distribution pattern was complementary to that of collagen fibres, with a much greater density of elastic fibres apparent in the central region than in the superficial and deep regions. This distribution of collagen and elastic fibres in the fetal vocal fold mirrors that classically described for the adult vocal ligament, suggesting that a vocal ligament has already begun to develop by the time of birth. The apparently high level of organization of connective tissue components in the newborn is in contrast to current hypotheses that argue that the mechanical stimuli of phonation are essential to the determination of the layered structure of the lamina propria and suggests that genetic factors may play a more significant role in the development of the vocal ligament than previously believed.

Gross morphology and surface ultrastructure of the gills of Odontesthes argentinensis (Actinopterygii, Atherinopsidae) from a Southwestern Atlantic coastal lagoon.

Odontesthes argentinensis was collected from Mar Chiquita Coastal Lagoon, the Southernmost coastal Atlantic Lagoon of Argentina. The morphology of the gills was analyzed by scanning electron microscopy. The morphology of the superficial structures of the gill filaments and pharyngeal region of the gill arch was discussed and related to their functional aspects. The gills arches are structurally similar to those of other teleosts and bring out the osmoregulatory capacity of this species. The epithelium that covers the surface of the filaments and the pharyngeal region of the gill arch is formed by polygonal pavement cells with conspicuous microridges. These folds in the membrane are not denoted in the epithelium of the respiratory lamellae. Apical crypts of chloride cells are present on the afferent and interlamellar filament surfaces, but are absent elsewhere on the gill arch. The highest density of mucous cells is observed into the gill filament and the pharyngeal region which indicates the existence of a protective strategy of the respiratory lamellae and the pharynx. The epithelium of the gill arches and the rakers is studded with spines. There are taste buds along the whole pharyngeal region that may be associated with their participation in tasting at this zone.

Disarrangement of collagen fibers in Reinke's edema.

OBJECTIVE/HYPOTHESIS: To describe the arrangement of collagen fibers in the superficial layer of the lamina propria of the vocal folds with Reinke' edema. STUDY DESIGN: Cross sectional analysis of the lamina propria of the vocal folds with Reinke's edema (RE). METHOD: The picrosirius polarization method was used to study the arrangement of collagen fiber. Findings of collagen disarrangement were categorized semiquantitatively and correlated with RE severity, age, cigarette smoking and duration of dysphonia. RESULTS: Analysis of 20 specimens of vocal folds with RE showed that the intertwined network of collagen fibers resembling a wicker-basket normally observed in vocal folds was disarranged in RE. The collagen fibers were loosely arranged, fragmented and intermixed with varying amounts of myxoid stroma. Moderate and large areas of disarrangement (90% of cases) predominated. Collagen fiber arrangement in the region underneath the epithelium was better preserved when compared with fibers in the deeper region of the superficial layer of the lamina propria. There was a statistical difference in collagen disarrangement between grade II and grade III severity (P = .007) that appeared to be due to the large areas of disarrangement observed in 73% of patients with grade III severity and in 44% of grade II severity. Age was the only variable correlated with collagen fiber disarrangement (r = 0.47, P = .037). CONCLUSION: Our findings suggest that the flexible framework which maintains the uniformity of the lamina propria was lost in RE caused by the disarrangement of the collagen fibers.

Histological evaluation of maxillary sinus mucosa after functional endoscopic sinus surgery.

BACKGROUND: This study was performed to evaluate the histological changes of the maxillary sinus mucosa of patients with chronic rhinosinusitis (CRS) after functional endoscopic sinus surgery (FESS). METHODS: In a cohort study, biopsy specimens were collected from the maxillary sinus of patients submitted for FESS. One year after surgery, patients were clinically reassessed. Patients showing recurrence of disease (group 1) required a revision surgery, through which a second biopsy specimen was collected. Patients showing a favorable clinical response (group 2) were submitted to an outpatient maxillary biopsy through the previous opened middle meatus antrostomy. Biopsy material from four cadavers was used as control. The histological and electron microscope findings were analyzed. RESULTS: At the initial surgery, patients presented many histopathological alterations, such as an inflammatory process infiltrating the submucosa, atypical respiratory epithelium with an important increase in goblet cells, metaplasia, or mixed epithelium. Group 1 patients persisted with the same alterations 1 year later, but ciliary dysmorphy was more accentuated. Group 2 patients presented a predominantly pseudostratified epithelium, but some areas contained an increased number of goblet cells and a reduction in the number of ciliated cells. CONCLUSION: Recovery of the maxillary sinus mucosa of patients with CRS, observed by electron and light microscopy, was incomplete 1 year after endoscopic surgery, even in nonsymptomatic patients; nevertheless, these alterations were more important in symptomatic patients than in asymptomatic patients.

Mucous Membrane of the Rumen of Ovines, Fed With Spineless, Forrage Cactus or Palm (Barbary Fig) (Opuntia ficus indica Mil): Hystochemical Study by Means of Light Microscopy / Membrana Mucosa del Rumen de Ovinos, Alimentados con Forraje de Cactus Sin Espinas o Palmeras (Barbary Fig) (Opuntia ficus indica Mil): Estudio Histoquímico por Medio de Microscopía de Luz

The mucosa of the rumen performs the functions of absorption, transportation, metabolism and protection, due to the presence of microorganisms in this compartment of the digestive tract, which are responsible for the digestion of approximately 60% of the organic material apparently digested. The histological structure and the histochemical profile of glicoconjugate of the mucosa of the stomach of sheep that were being fed with forrage cactus or palm (Giant Palm - Opuntia ficus indica Mil)1. Twelve sheep were used, with approximately 14 months old, which were oddly distributed in four diets: D1- 60.0% forrage palm + 40.0% concentrated ration; D2- 47.5% forrage palm + 12.5% elephant, napier grass + 40.0% concentrated ration, and D3 - 34,8% forrage palm + 25.2% elephant, napier grass + 40.0% concentrated ration and D4 - 60.0% elephant, napier grass + 40.0% concentrated ration. The experience period lasted 90 days, and, at the end, the animals were euthanized and fragments of different compartments of their stomachs were taken right after. The animals having consumed diets D1, D2 e D3 presented more developed papillas, while the ones of diet D4, presented less developed papillas. The stratum corneum of the epithelium of the rumen coating of the animals in diet D1 presented a slight erosion, when compared to those in diets D2, D3 and D4.

La mucosa del rumen actúa en la absorción, transporte, metabolismo y protección, debido a la presencia de microorganismos en este compartimiento del tracto digestivo, los cuales son responsables de la digestión de aproximadamente el 60% de material orgánico aparentemente digerido. Se analizó la estructura histológica y el perfil histoquímico de las estructuras de glicoconjugados de la mucosa del estómago de las ovejas que fueron alimentadas con forraje de cactus o palmeras (Giant Palm - Opuntia ficus indica Mil)1. Fueron utilizadas 12 ovejas, con aproximadamente 14 meses de edad, las cuales fueron distribuidas de manera impar en cuatro dietas: D1- 60.0% forraje de palmera + 40.0% ración concentrada; D2- 47.5% forraje de palmera + 12.5% hierba alta africana + 40.0% ración concentrada, y D3 - 34,8% forraje de palmera + 25.2% hierba alta africana + 40.0% ración concentrada y D4 - 60.0%hierba alta africana + 40.0% ración concentrada. La experiencia duró 90 días y al final, los animales fueron sacrificados y fragmentos de diferentes compartimientos de sus estómagos fueron directamente recogidos. Los animales que habían consumido dietas D1, D2 y D3 presentaron papilas más desarrolladas, mientras que los alimentados con dieta D4 presentaron papilas menos desarrolladas. El estrato córneo del epitelio del rumen de los animales de la dieta D1 presentaron pequeña erosión, cuando fueron comparados con los animales sometidos a las dietas D2, D3 y D4.

Effects of São Paulo air pollution on the upper airways of mice.

The nose is the first region of the respiratory tract to come in contact with airborne pollutants. Previous studies have shown that the nasal mucosa can be altered in response to air pollution. In this study, we quantified neutral and acidic mucus in three different levels of the nasal cavity of mice exposed to ambient levels of air pollution in the city of São Paulo, Brazil. Two groups of 6-day-old male Swiss mice were placed in two exposure chambers. Mice were maintained in the chambers 24 h/day, 7 days/week for 5 months. The first chamber contained an air filter device (clean chamber; n=20), whereas the second one received ambient air pollution (polluted chamber; n=20). We measured the concentration of PM(2.5), nitrogen dioxide (NO2), and black carbon inside both chambers. The nasal cavity was transversely sectioned at three specific anatomic locations (proximal, medial, and distal levels) and submitted to quantitative analysis of the amounts of neutral and acidic mucosubstances. We observed a 37.85% decrease in NO2, 54.77% decrease in PM(2.5), and 100% decrease in black carbon concentration in the clean chamber compared to the polluted chamber. Significant differences between polluted and clean chambers were observed in the epithelium lining the septum of proximal and medial levels of the nasal mucosa, with an increase in the percentage of acidic mucus in the polluted chamber (P=0.037, proximal level; P=0.023, medial level). We conclude that prolonged exposure to low levels of ambient air pollution from an early age shows evidence of causing secretory changes in the nasal cavity of mice, with increased production of acidic mucosubstances.

Paul Langerhans: aspectos relacionados con su vida y obra / Paul Langerhans: aspects related to his life and work

Se describen los aspectos relacionados con la vida y obra de Paul Langerhans, con especial atención a las células de Langerhans de la piel y mucosas, y a los islotes de Langerhans del páncreas (AU)

Ultrastructure of the urethra of the Mongolian gerbil.

OBJECTIVE: The urethra is the main port of entry of sexually transmitted pathogens. However, papers on the morphology of the urethra are scarce. The Mongolian gerbil is a rodent native of the Mongolia and China and has been utilized as a laboratory animal since the 1960s. This work describes the ultrastructure of the urethra of the Mongolian gerbil to provide data for future experimental studies. METHODS: The urethra of ten adult male gerbils was studied by transmission electron microscopy. RESULTS: The epithelium of the pelvic urethra possesses two cell types: I and II, without the formation of cellular layers, while the penile urethra possesses cellular layers: basal, intermediate and superficial. The urethra presents neurosecretory cells belonging to the amine precursor uptake and decarboxylation system. CONCLUSIONS: The urethral epithelium of the gerbil is a neurosecretory epithelium, part of the amine precursor uptake and decarboxylation system.

Serous cutaneous glands in new world hylid frogs: an ultrastructural study on skin poisons confirms phylogenetic relationships between Osteopilus septentrionalis and Phrynohyas venulosa.

Transmission electron microscope investigations of the serous (poison) skin glands in the New World tree frogs Osteopilus septentrionalis and Phrynohyas venulosa revealed that they produce granules with closely similar substructures, namely, a dense cortex and pale medulla. In both species these features, that contrast the complex, sometimes repeating patterns described in other hylid frogs, derive from similar secretory and maturational processes starting from the Golgi phase of poison biosynthesis. Observations on secretory discharge showed that the two species share common release mechanisms, based on bulk discharge (holocrine) processes. Our data provide novel evidence of the extensive ultrastructural polymorphism of serous skin products in Hylidae and agree with phylogenies that regard this family as polyphyletic in origin. Assuming that ultrastructural features of cutaneous poison biosynthesis and maturation are adequate clues for tracking anuran phylogeny, the present findings also support a close relationship between Osteopilus and Phrynohyas taxa as previously suggested by osteological evidence.

High laryngeal mask airway pressures resulting from nitrous oxide do not increase pharyngeal mucosal injury in dogs.

PURPOSE: During general anesthesia, nitrous oxide (N2O) diffuses rapidly into the air-filled laryngeal mask airway (LMA) cuff, increasing intracuff pressure. There is no clear correlation between LMA intracuff pressure and pressure on the pharynx. We have studied the effects of high LMA intracuff pressures secondary to N2O on the pharyngeal mucosa of dogs. METHODS: Sixteen mongrel dogs were randomly allocated to two groups: G1 (intracuff volume, 30 mL; n=8) breathed a mixture of O2 (l L x min(-1)) and air (l L x min(-1)) and G2 (intracuff volume, 30 mL; n=8) a mixture of O2 (l L x min(-1)) and N2O (l L x min(-1)). Anesthesia was induced and maintained with pentobarbitone. LMA cuff pressure was measured at zero (control), 30, 60, 90 and 120 min after #4 LMA insertion. The dogs were sacrificed, and biopsy specimens from seven predetermined areas of the pharynx in contact with the LMA cuff were collected for light (LM) and scanning electron microscopic (SEM) examination by a blinded observer. RESULTS: LMA intracuff pressure decreased with time in G1 (P <0.001) and increased in G2 (P <0.001). There was a significant difference between the groups (P <0.001). In both groups, the LM study showed a normal epithelium covering the pharyngeal mucosa and mild congestion in the subepithelial layer. There were no differences between the groups (P >0.10) or among the areas sampled (P >0.05). In both groups, the SEM study showed a normal pharyngeal mucosa with mild superficial desquamation. Few specimens in G1 and G2 showed more intense epithelial desquamation. CONCLUSION: High LMA intracuff pressures produced by N2O do not increase pharyngeal mucosal injury in dogs.

[New observations on the structure of the lingual filiform papillae epithelium of the toad Bufo marinus L.: Light and transmission electron microscopy study]. / Nuevas observaciones en la estructura del epitelio de las papilas filiformes de la lengua del sapo Bufo marinus L.: estudio con microscopia de luz y electrónica de transmisión.

There are several inconsistencies and confusions about the microscopic structure in the anurans dorsal, non-sensory, mucosal epithelium of the tongue. The aim of this work was to differentiate the structure of the epithelium covering filiform papillae from the glandular epithelium. For this, samples of the dorsal distal mucosa of Bufo marinus tongue were processed for light microscopy (LM) and transmission electron microscopy (TEM). For LM, stained 1 micron sections were used. The results showed that the filiform papillae were covered by a biestratified epithelium formed by a basal layer of dendritic cells and an upper surface layer consisting of numerous seromucous secretory cells, dendritic cells apical processes, and some goblet cell-like and ciliated cells. LM revealed that most filiform papillae showed the seromucous secretory cells in apparent resting state. These cells were characterized by a basal, round nucleus, pale cytoplasm with small, dispersed, stained granules in the supranuclear region. With TEM, seromucous secretory cells exhibited poorly developed RER, scattered medium electron dense secretory granules and microridges at the apical surface. Dendritic cells were seen as branched cells completely surrounding the basolateral surfaces of secretory cells. In addition, some dendritic cell processes have microvilli at their abutting endings. Goblet cell-like cells theca showed a continuous mesh of medium electron dense, partially fused, mucous granules and irregular microvilli-like processes at the apical end. Ciliated cells were mostly localized at the lateral wall of filiform papillae. Results suggest that at the filiform papillae, yuxtacrine or paracrine interactions mediated by physical contacts between dendritic and secretory cells may exist.