Morphological alterations in salivary glands of Rhipicephalus sanguineus ticks (Acari: Ixodidae) exposed to neem seed oil with known azadirachtin concentration.

Neem (Azadirachta indica) has attracted the attention of researchers worldwide due to its repellent properties and recognized effects on the morphology and physiology of arthropods, including ticks. Therefore, this study aimed to demonstrate the effects of neem seed oil enriched with azadirachtin on salivary glands of Rhipicephalus sanguineus ticks, targets of great veterinary interest because of their ability to transmit pathogens to dogs. For this, R. sanguineus semi-engorged females were subjected to treatment with neem seed oil, with known azadirachtin concentrations (200, 400 and 600ppm). After dissection, salivary glands were collected and evaluated through morphological techniques in light microscopy, confocal scanning laser microscopy and transmission electron microscopy, so that the possible relation between neem action and further impairment in these ectoparasites feed performance could be established. Neem oil demonstrated a clear dose-dependent effect in the analyzed samples. The agranular (type I) and granular acini (types II and III) showed, particularly in individuals treated with the highest concentrations of the product, cells with irregular shape, intense cytoplasmic disorganization and vacuolation, dilation of rough endoplasmic reticulum lumen, besides alterations in mitochondrial intermembrane space. These morphological damages may indicate modifications in salivary glands physiology, demonstrating the harmful effects of compounds present in neem oil on ticks. These results reinforce the potential of neem as an alternative method for controlling R. sanguineus ticks, instead of synthetic acaricides.

Morphological effects of neem (Azadirachta indica A. Juss) seed oil with known azadirachtin concentrations on the oocytes of semi-engorged Rhipicephalus sanguineus ticks (Acari: Ixodidae).

The concern about the harmful effects caused by synthetic pesticides has led to the search for safe and ecological alternatives for pest control. In this context, the neem tree (Azadirachta indica) stands out due to its repellent properties and effects on various arthropods, including ticks. For this reason, this study aimed to demonstrate the potential of neem as a control method for Rhipicephalus sanguineus ticks, important vectors of diseases in the veterinary point of view. For this, R. sanguineus semi-engorged females were subjected to treatment with neem seed oil enriched with azadirachtin, its main compound, and ovaries were assessed by means of morphological techniques in conventional light microscopy, confocal laser scanning microscopy, and transmission electron microscopy. Neem demonstrated a clear dose-dependent effect in the analyzed samples. The observed oocytes presented, especially in the groups treated with higher concentrations of neem oil, obvious signs of cytoplasmic disorganization, cellular vacuolization, nuclear and nucleolar irregularity, dilation in mitochondrial cristae, alterations in mitochondrial matrix, and swelling of rough endoplasmic reticulum. Intracellular microorganisms were observed in all analyzed groups, reinforcing the importance of ticks in the transmission of pathogens. A greater quantity of microorganisms was noted as the concentration of neem increased, indicating that the damaged oocytes may be more susceptible for their development. Such morphological alterations may promote future damages in reproductive performance of these animals and demonstrate the potential of neem seed oil for the control of R. sanguineus ticks, paving the way for new, cheaper, and safer methods of control.

Morphological alterations in the synganglion and integument of Rhipicephalus sanguineus ticks exposed to aqueous extracts of neem leaves (Azadirachta indica A. JUSS).

Currently, the necessity of controlling infestation by ticks, especially by Rhipicephalus sanguineus, has led researchers and public health managers around the world to search for new and more efficient control methods. This way, we can highlight neem (Azadirachta indica A. Juss) leaf, bark, and seed extracts, which have been very effective on tick control, and moreover causing less damage to the environment and to the host. This study showed the potential of neem as a control method for R. sanguineus through morphological and morphometric evaluation of the integument and synganglion of females, in semiengorged stage. To attain this, routine techniques of optical microscopy, scanning electron microscopy and morphometry of the cuticle and subcuticle of the integument were applied. Expressive morphological alterations were observed in both organs, presenting a dose-dependent effect. Integument epithelial cells and nerve cells of the synganglion showed signs of cell vacuolation, dilated intercellular boundaries, and cellular disorganization, alterations not previously reported in studies with neem. In addition, variations in subcuticle thickness were also observed. In general, the effects of neem are multiple, and affect the morphology and physiology of target animals in various ways. The results presented in this work are the first evidence of its effects in the coating and nervous system of ticks, thus allowing an indication of neem aqueous extracts as a potential control method of the brown dog tick and opening new perspectives on acaricide use.

Rhipicephalus sanguineus (Acari: Ixodidae) female ticks exposed to castor oil (Ricinus communis): an ultrastructural overview.

Tick control has been accomplished through the use of synthetic acaricides, which has created resistant individuals, as well as contaminating the environment and nontarget organisms. Substances of plant origin, such as oils and extracts of eucalyptus and neem leaves, have been researched as an alternative to replace the synthetic acaricides. Ricinoleic acid esters from castor oil have recently been shown as a promising alternative in eliminating bacterial contamination during ethanol fermentation, by acting as an effective biocide. The same positive results have been observed when these esters are added to the food given to tick-infested rabbits. This study tested the effect of these substance on the reproductive system of Rhipicephalus sanguineus females, added to rabbit food, more specifically on oogenesis. For this, four groups were established: four control groups (CG1, CG2, CG3, and CG4) and four treatment groups (TG1, TG2, TG3, and TG4) with one rabbit in each (New Zealand White), used as hosts. After full 4 days feeding (semi-engorgement), the females were collected and had their ovaries extracted. In this study, it was observed that R. sanguineus females exposed to esters had their ovaries modified, which was demonstrated through transmission electron microscopy techniques. The addition of ricinoleic esters to the diet of tick-infested rabbits revealed how toxic such substances are for the cytoplasmic organelles of oocytes and pedicel cells. These compounds can change the morphophysiology of germ and somatic cells, consequently influencing their viability and, therefore, confirming that the ricinoleic acid esters from castor oil are a promising substance in the control of R. sanguineus.

Prolonged acceptance of skin grafts induced by B cells places regulatory T cells on the histopathology scene.

The participation of regulatory T (Treg) cells in B cell-induced T cell tolerance has been claimed in different models. In skin grafts, naive B cells were shown to induce graft tolerance. However, neither the contribution of Treg cells to B cell-induced skin tolerance nor their contribution to the histopathological diagnosis of graft acceptance has been addressed. Here, using male C57BL/6 naive B cells to tolerize female animals, we show that skin graft tolerance is dependent on CD25+ Treg cell activity and independent of B cell-derived IL-10. In fact, B cells from IL-10-deficient mice were able to induce skin graft tolerance while Treg depletion of the host inhibited 100% graft survival. We questioned how Treg cell-mediated tolerance would impact on histopathology. B cell-tolerized skin grafts showed pathological scores as high as a rejected skin from naive, non-tolerized mice due to loss of skin appendages, reduced keratinization and mononuclear cell infiltrate. However, in tolerized mice, 40% of graft infiltrating CD4+ cells were FoxP3+ Treg cells with a high Treg:Teff (effector T cell) ratio (6:1) as compared to non-tolerized mice where Tregs comprise less than 8% of total infiltrating CD4 cells with a Treg:Teff ratio below 1:1. These results render Treg cells an obligatory target for histopathological studies on tissue rejection that may help to diagnose and predict the outcome of a transplanted organ.

Secretory process of salivary glands of female Amblyomma cajennense (Acari: Ixodidae) ticks fed on resistant rabbits.

Ticks have great economic and health importance since infested animals have reduced milk and meat production, and, besides that, they are expensive ectoparasites to control. While feeding, ticks can transmit to their hosts a large amount of pathogens, including Rickettsia rickettsii responsible for the "spotted fever" or "fever of the mountains." It is known that animals infested with ticks or artificially immunized with their salivary gland extracts develop resistance, which is related to a decrease in engorged female weight, in egg-laying by adults, in egg viability and, in some cases, in the capacity of pathogens transmission. The present study aimed to examine morpho-histochemically the female salivary glands of semi and engorged Amblyomma cajennense fed on resistant rabbits. The results revealed that acinus I had no changes when compared to that of females fed on naive rabbits. The c cells of acinus II showed signs of early degeneration, which may result in feeding efficiency decrease. In acinus III d cells, activity time was longer. Such occurrence was associated with the time of female fixation, which increased in females fed on resistant hosts.

Dieta enriquecida em fibras e ácidos graxos poli-insaturados: efeitos no controle glicêmico e perfil lipídico de ratos diabéticos / Diet enriched in fiber and polyunsaturated fatty acids: effects in glucose control and lipid profile in diabetic rats

O uso de alimentos funcionais na promoção da saúde e controle de doenças crônicas não transmissíveis tem sido amplamente estudado. As fibras têm sido utilizadas na dieta de animais em que o controle glicêmico está prejudicado em decorrência do diabetes. Contudo, não foram encontrados estudos avaliando a utilização de dieta incluindo combinação de alimentos ricos em fibras e ácidos graxos poliinsaturados em modelos experimentais dessa doença. Este trabalho avaliou o efeito de dieta enriquecida em fibras e ácidos graxos poli-insaturados sobre o controle glicêmico e perfil lipídico de ratos diabéticos. Ratos Wistar machos foram distribuídos aleatoriamente em três grupos de sete animais: diabético controle (D); diabético com suplementação alimentar a base de aveia, linhaça, gergelim e girassol (DS); e controle normal (C) constituído por animais que receberam tampão citrato (0,2 mL/100g de peso corporal i.v.) no momento da indução do diabetes. O tratamento foi iniciado no 5º dia após indução do diabetes com estreptozocina 40 mg/kg i.v. em tampão citrato. Foram considerados diabéticos animais com glicemia de jejum ≥250 mg/dL. Após 50 dias de tratamento foram determinados os níveis séricos de glicose, frutosamina, colesterol total e frações e triglicerídeos, e o percentual de hemoglobina glicada. O peso corporal, diurese, consumo alimentar e ingestão hídrica também foram mensurados, além da composição química das rações utilizadas também foi determinada. A análise estatística foi realizada por meio do teste t pareado e ANOVA seguida de teste de Tukey. diabetes resultou em polifagia, poliúria e polidpisia, além de aumento nos níveis de colesterol total, LDL-c, triglicerídeos, frutosamina, e glicação da hemoglobina em relação aos animais não diabéticos. A suplementação produziu redução nos níveis de triglicerídeos e LDL-c quando comparados com o grupo D. Embora a suplementação da dieta tenha resultado em níveis de triglicerídeos e LDL-c semelhantes aos do grupo C e redução dos níveis de colesterol total, não foi eficiente em melhorar o controle metabólico de diabetes induzido por estreptozotocina.

The use of functional foods in health promotion and the control of chronic non-transmittable diseases has been extensively studied. The fibers have been used in the diet of animals that glycemic control is impaired due to diabetes, but no studies were found evaluating the use of combination of diet including food rich in fiber and polyunsaturated fatty acids in experimental models of this disease. This study evaluated the effect of diet enriched with fiber and polyunsaturated fatty acids on the glycemic control and lipid profile of diabetic rats. Male Wistar rats were randomly divided into the following three groups of seven animals: diabetic control (D), diabetic with dietary supplementation (DS), and normal control (C) consisting of animals that received citrate buffer (0.2 mL/100 g body weight i.v.) instead of diabetogenic drug. Treatment started on the fifth day after induction of diabetes with 40 mg/kg i.v. streptozotocin. Animals were considered diabetic when their fasting glucose was≥250 mg/dL. After 50 days of treatment were determined serum levels of glucose, fructosamine total and fractions cholesterol, triglycerides, and the percentage of glycated hemoglobin. Body weight, urine output, food consumption and water intake were also measured. Diets chemical compositions were determined. Statistical analysis was carried out using the paired t test and ANOVA followed by Tukey's test. The diabetes resulted in polyphagia, polyuria and polidpisia and increased levels of total cholesterol, LDL cholesterol, triglycerides, fructosamine, and hemoglobin glycation when compared with the non- diabetic animals. Supplementation produced a reduction in triglycerides and LDL-c when compared with group D. Although the supplementation of the diet resulted in levels of triglycerides and LDL-c similar to those of group C and a reduction of total cholesterol levels, it was not effective at improving metabolic control in streptozotocin-induced DM.

Antiulcerogenic activity of Combretum leprosum.

This study investigates the effects of an ethanolic extract from the stem bark of Combretum leprosum Mart. & Eiche (Combretaceae) on experimental ulcers induced by ethanol and indomethacin and on gastric secretion and mucus content in pylorus-ligated rats. The effects were compared with those of ranitidine and carbenoxolone. Combretum leprosum orally administered elicited a complete inhibition of the appearance of gastric lesions induced by ethanol and a partial reduction when indomethacin was used as an ulcerogenic agent. Moreover, the protection against gastric ulceration induced by ethanol was decreased with indomethacin pretreatment. The intraduodenal administration of Combretum leprosum in four-hour pylorus-ligated rats increased the volume and pH of gastric juice while decreasing the acid output and produced a significant increase in gastric wall mucus content. The major compounds detected in a preliminary phytochemical screening were triterpenes, flavonoids, taninns and saponins. This study provides evidence that the ethanolic extract of Combretum leprosum possesses gastroprotective and anti-ulcerogenic effects, which are related to the inhibition of the gastric acid secretion and an increase of mucosal defensive factors such as mucus and prostaglandin.

Morphological changes in the salivary glands of Amblyomma cajennense females (Acari: Ixodidae) in different feeding stages on rabbits at first infestation.

This study examined salivary glands of unfed, partially engorged, and engorged females of the tick Amblyomma cajennense on rabbits at first infestation using histological and histochemical techniques. In type I acini, no significant changes were observed among the three feeding conditions. In type II acini of unfed females, c1, c2, and c4 cells were described for the first time in this species. In a comparison among the three feeding conditions, an increase in this acinus was observed, due to the increase in secretion in c1, c2, and c4 cells and the appearance of c3 cells. In engorged females, some cells were still active. Type III acini presented cells d, e, and f containing secretion in unfed females. In partially engorged females, these cells were devoid of secretion. In engorged females, type III acini exhibited a reduced lumen. After engorgement, all acini underwent a degenerative process, as observed in females after two to five days post-engorgement.

[Nursing and AIDS: knowledge and paradigm]. / Enfermagem e AIDS: saber e paradigma.

This study is a part of a research that comments the relation between Nursing Knowledge and AIDS. The actual period of time is treated like a period of transition between the modern science and one new paradigm. This is called post-modern science. It brings the dynamics of AIDS in Brazil after the registration of 79,908 cases from 1980 to 1996. The main objective is to describe nursing knowledge that has based nursing care to seropositive and aidetic patients in an University-Hospital located in Rio de Janeiro, Brazil.

Basosquamous cell carcinoma of the skin with metastases.

Two cases of basosquamous cell carcinoma of the skin with lymph node, lung and bone metastases are reported. Metastases occurred 4 and 7 years after identification of the primary tumour. Both the primary and metastatic lesions had areas of typical basal cell carcinoma and squamous cell carcinoma and also intermediate carcinomatous tissue. In the bone metastasis of one case there were rudimentary hair follicles and areas of matrical differentiation. These cases further support the existence of basosquamous cell carcinoma and emphasize its metastatic potential.

Antipyretic activity of an aqueous extract of Zizyphus joazeiro Mart. (Rhamnaceae).

Bark infusions of Zizyphus joazeiro Mart. (Rhamnaceae) have been employed in Northeastern Brazil as a remedy for fever. This study investigated the antipyretic activity of an aqueous extract of the plant in rabbits rendered febrile by intravenous injection of E. coli endotoxin. Fever responses were significantly decreased (P less than 0.05) by the oral administration of a bark infusion of Z. joazeiro Mart. These results lend support to the popular use of infusions of this plant in folk medicine as a remedy for fever and suggest that the characterization of the principle(s) responsible for such activity deserves further investigation.