Spontaneously hypertensive rat as experimental model of salivary hypofunction

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Oral Rehabilitation After Surgical Removal of Pleomorphic Adenoma

Although tumors of minor salivary glands are rare, the pleomorphic adenoma is the most common pathology among the benign neoplasm and can be found with high prevalence in the junction between hard palate and soft palate. The treatment of choice for most of maxillary tumors is surgical through either a total or partial maxillectomy. However, surgical defects caused by such type of treatment lead to both clinical and psychologic disorders for the patient. The immediate oral rehabilitation using interim palate obturator after maxillectomy provides optimization on the healing process, recovers the stomatognathic functions after surgery, and avoids psychosocial sequelae for the patients. This clinical report aimed to present the rehabilitation with immediate palate obturator of a patient who underwent a partial maxillectomy due to a hard palate pleomorphic adenoma of minor salivary glands. We report the clinical importance of the prosthetic rehabilitation and the improvements on both quality of life and stomatognathic functions of this patient. It can be concluded that the immediate rehabilitation of the patient after partial maxillectomy by using an interim palate obturator was a great option and provided clinical benefits in the immediate postoperative period, improving the patient's quality of life, allowing the patient's reinsertion into society, and reducing the surgical treatment sequelae.

Protective efficacy of Psidium cattleianum and Myracrodruon urundeuva aqueous extracts against caries development in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Congenital fistulae of the lower lip in Van der Woude syndrome: A histomorphological study

Objective: To evaluate a significant number of cases of fistulae of the lower lip with the light microscope in order to investigate the histological variation and to attempt to define the histopathological pattern of the lesion.Methods: Congenital fistulae of the lower lips of 17 patients with Van der Woude syndrome were analyzed by light microscopy,Results and Conclusion: the walls of most of the fistulae consisted of stratified nonkeratinized squamous epithelium and a lamina propria of dense connective tissue with areas of lymphohistiocytic inflammatory infiltrates. Bundles of striated muscle fibers, blood vessels, nerves, adipose tissue, and mixed acinar glands were observed. These glands surrounded the entire wall of the lesion, and their excretory ducts opened into the lumen of the fistula, explaining the clinical observation of elimination of mucous secretion through the opening of the fistula, Two microform cases of fistula were analyzed that presented only a depression in the epithelium at the site corresponding to the opening of the fistula.

Damage of the medial preoptic area impairs peripheral pilocarpine-induced salivary secretion

The existence of neural connections between the medial preoptic area (MPOA) and the salivary glands and the increase in salivation by thermal or electrical stimulation of the MPOA have suggested an important role of MPOA in the control of salivary gland function. Although direct cholinergic activation of the salivary glands induces salivation, recent studies have suggested that salivation produced by i.p. pilocarpine may also depend on the activation of central mechanisms. Therefore, in the present study, we investigated the effects of bilateral electrolytic lesions of the MPOA on the salivation induced by i.p. pilocarpine. Adult male Holtzman rats (n = 11-12/group) with bilateral sham or electrolytic lesions of the MPOA were used. One, five, and fifteen days after the brain surgery, under ketamine anesthesia, the salivation was induced by i.p. pilocarpine (1 mg/kg of body weight), and saliva was collected using preweighted small cotton balls inserted into the animal's mouth. Pilocarpine-induced salivation was reduced 1 and 5 days after MPOA lesion (341 +/- 41 and 310 +/- 35 mg/7 min, respectively, vs. sham lesions 428 +/- 32 and 495 +/- 36 mg/7 min, respectively), but it was fully recovered at the 15th day post-lesion (561 +/- 49 vs. sham lesion: 618 27 mg/7 min). Lesions of the MPOA did not affect baseline non-stimulated salivary secretion. The results confirm the importance of MPOA in the control of salivation and suggest that its integrity is necessary for the full sialogogue effect of pilocarpine. However, alternative mechanisms probably involving other central nuclei can replace MPOA function in chronically lesioned rats allowing the complete recovery of the effects of pilocarpine. (c) 2006 Published by Elsevier B.V.

Sympathetic mediation of salivation induced by intracerebroventricular pilocarpine in rats

Central cholinergic activation by pilocarpine induces salivation dependent on the integrity of forebrain areas. The present work investigates the autonomic mediation of this salivation. Pilocarpine (500 nmol/rat) was injected into the lateral ventricle (LV) of tribromoethanol-anesthetized adult male rats. Preweighed cotton balls were inserted into the oral cavity and weighed again 7 min later. ol-adrenoceptor antagonists (3-50 mu mol/kg) prazosin (alpha(1)), yohimbine (alpha(2)) or propranolol (beta) injected intraperitoneally (i.p.) produced, 80%, 20% and 0% inhibition respectively of the LV pilocarpine-induced salivation. Intracerebroventricular injections (160 nmol) of the antagonists did not alter the effects of pilocarpine injected into the LV. Bilateral section of chorda tympani nerve or bilateral sympathetic cervical ganglionectomy produced 0% and 40% inhibition of pilocarpine-induced salivation, respectively. Ganglionectomy did not alter salivation induced by i.p, injection of pilocarpine (4 mu mol/kg). The results indicate that there is a large sympathetic contribution to the salivation induced by central cholinergic activation. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Lesions of the lateral hypothalamus impair pilocarpine-induced salivation in rats

In the present study we investigated the effects of electrolytic lesions of the lateral hypothalamus (LH) in the salivation induced by intracerebroventricular (i.c.v.) or intraperitoneal (i.p.) injection of the cholinergic agonist pilocarpine. Rats with sham or LH lesions and stainless steel cannulas implanted into the lateral ventricle (LV) were used. In rats anesthetized with urethane (1.25 mg/kg of body weight) saliva was collected using pre-weighed cotton balls inserted in the animal mouth during a period of 7 min following i.c.v. or i.p. injection of pilocarpine. Injection of pilocarpine (1 mg/kg of body weight) i.p. in sham-operated rats (6 h, 2, 7, and 15 days after the surgery) induced salivation (497+/-24, 452+/-26, 476+/-30, and 560+/-75 mg/7 min, respectively). The effects of i.p. pilocarpine was reduced 6 h, 2 and 7 days after LH lesions (162+/-37, 190+/-32, and 229+/-27mg/7 min, respectively), not 15 days after LH lesions (416+/-89mg/7 min). Injection of pilocarpine (120 mug/mul) i.c.v., in sham-operated rats (6 h, 2, 7, and 15 days after the surgery) also produced salivation (473 20, 382 16, 396 14, and 427 47 mg/7 min, respectively). The salivation induced by i.c.v. pilocarpine was also reduced 6 h, 2 and 7 days after LH lesions (243+/-19, 278+/-24, and 295+/-27 mg/7 min, respectively), not 15 days after LH lesions (385 48 mg/7 min). The present results show the participation of the LH in the salivation induced by central or peripheral injection of pilocarpine in rats, reinforcing the involvement of central mechanisms on pilocarpine-induced salivation. (C) 2002 Elsevier B.V. All rights reserved.

Central muscarinic receptors signal pilocarpine-induced salivation

Although cholinergic agonists such as pilocarpine injected peripherally can act directly on salivary glands to induce salivation, it is possible that their action in the brain may contribute to salivation. To investigate if the action in the brain is important to salivation, we injected pilocarpine intraperitoneally after blockade of central cholinergic receptors with atropine methyl bromide (atropine-mb). In male Holtzman rats with stainless steel cannulas implanted into the lateral ventricle and anesthetized with ketamine, atropine-mb (8 and 16 nmol) intracerebroventricularly reduced the salivation induced by pilocarpine (4 mumol/kg) intraperitoneally (133 +/- 42 and 108 +/- 22 mg/7 min, respectively, vs. saline, 463 +/- 26 mg/7 min), but did not modify peripheral cardiovascular responses to intravenous acetylcholine. Similar doses of atropine-mb intraperitoneally also reduced pilocarpine-induced salivation. Therefore, systemically injected pilocarpine also enters the brain and acts on central muscarinic receptors, activating autonomic efferent fibers to induce salivation.

Central muscarinic receptor subtypes involved in pilocarpine-induced salivation, hypertension and water intake

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Staining methods applied to glycol methacrylate embedded tissue sections

The use of glycol methacrylate (GMA) avoids some technical artifacts, which are usually observed in paraffin-embedded sections, providing good morphological resolution. on the other hand, weak staining have been mentioned during the use of different methods in plastic sections. In the present study, changes in the histological staining procedures have been assayed during the use of staining and histochemical methods in different GMA-embedded tissues.Samples of tongue, submandibular and sublingual glands, cartilage, portions of respiratory tract and nervous ganglion were fixed in 4% formaldehyde and embedded in glycol methacrylate. The sections of tongue and nervous ganglion were stained by H&E. Picrosirius, Toluidine Blue and Sudan Black B methods were applied, respectively, for identification of collagen fibers in submandibular gland, sulfated glycosaminoglycans in cartilage (metachromasia) and myelin lipids in nervous ganglion. Periodic Acid-Schiff (PAS) method was used for detection of glycoconjugates in submandibular gland and cartilage while AB/PAS combined methods were applied for detection of mucins in the respiratory tract. In addition, a combination of Alcian Blue (AB) and Picrosirius methods was also assayed in the sublingual gland sections.The GMA-embedded tissue sections showed an optimal morphological integrity and were favorable to the staining methods employed in the present study. In the sections of tongue and nervous ganglion, a good contrast of basophilic and acidophilic structures was obtained by H&E. An intense eosinophilia was observed either in the striated muscle fibers or in the myelin sheaths in which the lipids were preserved and revealed by Sudan Black B. In the cartilage matrix, a strong metachromasia was revealed by Toluidine Blue in the negatively-charged glycosaminoglycans. In the chondrocytes, glycogen granules were intensely positive to PAS method. Extracellular glycoproteins were also PAS positive in the basal membrane and in the region occupied by the lamina externa and reticular fibers surrounding each smooth muscle cells of the blood vessels. In the epithelial cells of the respiratory tract, acid and neutral mucins were histochemically detected by AB and PAS methods, respectively. Moreover, granules containing acid and neutral mucins were revealed in purple by AB and PAS concomitantly. In the sublingual gland sections, a distinct affinity of acid mucins by AB (in turquoise-blue) and collagen fibers by Picrosirius (in red) was obtained when these methods were combined. Although some routine dyes used in paraffin sections have showed a weak stain in historesin sections, our results showed that different dyes could be applied in GMA sections if modified staining procedures were assayed. Therefore, appropriate staining contrast and, thus, detection of one or different substances in a same section can be acquired in association to the good morphological resolution provided by GMA. (C) 2003 Elsevier Ltd. All rights reserved.

Ultrastructural features of the glandular region of the stomach of Piaractus mesopotamicus (Holmberg, 1887) with emphasis on the oxyntopeptic cell

The characteristics of the lining and glandular epithelial types of the wall of the stomach of pacu (Piaractus mesopotamicus Holmberg, 1887) were studied by transmission electron microscopy. Columnar mucous cells were observed in the lining epithelial surface and the glandular epithelium that invaginated in the lamina propria showed secretory cells or oxyntopeptic cells as called by some authors in the literature. The columnar epithelial cells are narrow and show a basal nucleus. They are rich in organelles and contain secretory granules of round or rectangular shape heterogeneously electron dense in the apical portion. In the basal region of the glands there are secretory cells. The luminal half of these cells has abundant tubules (tubulo-vesicular system) that communicate with the external medium. Deeper basally in the cytoplasm there are the nucleus, mitochondria of various shapes and other scattered organelles.

Alcoholism and coagulating gland: Androgen and insulin like growth factor-1 receptor features

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Ultrastructure and cytochemistry of the pearl gland in Piper regnellii (Piperaceae)

Pearl glands are scattered throughout the lamina of developing leaves and rarely found on adult leaves of Piper regnellii (Piperaceae). The pearl gland is a bicellular secretory trichome composed of a short broad basal cell and a spatula-like, semiglobular apical cell. Four different stages of the pearl grand were determined during its ontogenesis: origin, pre-secretory, secretory and post-secretory. During the pre-secretory stage, mitochondria, ribosomes, dictyosomes, rough endoplasmic reticulum, and plastids with electron dense inclusions were present in the cytoplasm of the apical cell. During the secretory stage, the most remarkable characteristics of the apical cell are the proliferation of dictyosomes and their vesicles, rough endoplasmic reticulum, and modified plastids. At this stage, electron-dense oil drops occur in the plastids as well as scattered within the cytoplasm, proteins and polysaccharides are seen in the plastids, vesicles, and vacuoles. Only polysaccharides are present in the periplasmic space, wall cavities, and on the surface of the apical cell. The polysaccharides are one of the main components of the mucilagenous exudate that covers the developing leaf structures. The apical cell of the senescing trichomes undergoes a progressive degeneration of its cellular components, the plastids being the first organelles to undergo lysis.

Ovary peltate trichomes of Zeyheria montana (Bignoniaceae): Developmental ultrastructure and secretion in relation to function

center dot Background and Aims Nectar production in the Bignoniaceae species lacking a nectariferous functional disc is ascribed to trichomatic glands around the ovary base and/or on the inner corolla wall. Nevertheless, knowledge about the secretion and function of these glands is very incomplete. The purpose of this paper is to study, from a developmental viewpoint, the ultrastructure, histochemistry and secretory process of the peltate trichomes on the ovary of Zeyheria montana, a species in the Bignoniaceae which has a rudimentary disc.center dot Methods Samples of the gynoecium at various developmental stages were fixed and processed for light and electron microscopy. Histochemistry and cytochemistry tests were performed to examine the chemical composition of exudates. Thin layer chromatography was used to determine the presence of alkaloids and terpenes in gynoecium and fruit extracts, and in fresh nectar stored in the nectar chamber.center dot Key Results Peltate trichomes at different developmental stages appear side by side from floral budding up to pre-dispersal fruit. Large plastids with an extensive internal membrane system consisting of tubules filled with lipophilic material, abundant smooth endoplasmic reticulum, few Golgi bodies, lipophilic deposits in the smooth endoplasmic reticulum and mitochondria, and scattered cytoplasmic oil droplets are the main characteristics of mature head cells. The secretion which accumulates in the subcuticular space stains positively for hydrophilic and lipophilic substances, with lipids prevailing for fully peltate trichomes. Histochemistry and thin layer chromatography detected terpenes and alkaloids. Fehling's test to detect of sugars in the secretion was negative.center dot Conclusions the continuous presence and activity of peltate trichomes on the ovary of Z. montana from early budding through to flowering and fruiting set, and its main chemical components, alkaloids and terpenes, suggest that they serve a protective function and are not related to the floral nectar source or to improving nectar quality.

Morfologia de nectários em Leguminosae senso lato em áreas de caatinga no Brasil

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