Mycobacterium bovis infection in goats from the Northeast Region of Brazil

A total of 8,058 male and female mixed-breed goats and 1-4 years of age were slaughtered over a period of 7 months at the public slaughterhouse of Patos city, Paraíba state, in the Northeast region of Brazil; 822 animals were inspected for gross lesions of tuberculosis, and 12 (1.46%) had lesions suggestive of tuberculosis in the mammary gland, lungs, liver and mediastinal, mesenteric, submandibular, parotid and prescapular lymph nodes. Presence of granulomatous lesions was confirmed in the submandibular lymph node of one (8.3%) goat at the histopathological examination and at the mycobacterium culture the same sample was confirmed positive. Isolate was confirmed as belonging to the M. tuberculosis complex by PCR restriction enzyme analysis (PRA). Spoligotyping identified the isolate into spoligotype SB0295 on the M. bovis Spoligotype Database website (www.mbovis.org), and it was classified as M. bovis. The occurrence of M. bovis in goats in this study suggests that this species may be a potential source of infection for humans and should be regarded as a possible problem in the advancement of control and eradication program for bovine tuberculosis in Brazil.

Multiple trichoblastomas in a dog

Background – Hair follicle tumours generally present as benign, solitary masses and have a good prognosis following surgical resection. Hypothesis/Objectives – This report describes a case of multiple trichoblastomas in a dog. Animal – A 2-year-old crossbred dog presented with multiple soft cutaneous periocular, perilabial, submandibular and nasal nodules, between 2 and 9 cm in diameter, located on the right side of the face. New nodules were observed on the same side of the face at a second consultation 3 weeks later. Methods – Surgical resection of all nodules was performed in two procedures. Three nodules were initially resected and submitted for histolopathology and immunohistochemistry. The diagnosis was trichoblastoma for all three. At the time of the second consultation, new and remaining nodules were biopsied and the diagnosis of trichoblastoma confirmed. The dog was treated with doxorubicin and piroxicam for 30 days prior to the second surgical procedure in an attempt to reduce new tumour growth and the size of present tumours. All nodules were resected and the defects closed using rotation flaps. Results – No recurrence of the neoplasm was noted within 10 months after surgery. Conclusions and clinical importance – Trichoblastomas are generally benign but can present as multiple neoplasms that may require surgical resection and may respond to chemotherapy. To the authors’ knowledge, this is the first report of multiple trichoblastomas in a dog.

Activation of central α(2)-adrenoceptors mediates salivary gland vasoconstriction

OBJECTIVE: Peripheral treatment with the cholinergic agonist pilocarpine increases salivary gland blood flow and induces intense salivation that is reduced by the central injection of moxonidine (α(2)-adrenoceptors/imidazoline agonist). In the present study, we investigated the effects of the intracerebroventricular (i.c.v.) injection of pilocarpine alone or combined with moxonidine also injected i.c.v. On submandibular/sublingual gland (SSG) vascular resistance. In addition, the effects of these treatments on arterial pressure, heart rate and on mesenteric and hindlimb vascular resistance were also tested. DESIGN: Male Holtzman rats with stainless steel cannula implanted into lateral ventricle and anaesthetized with urethane+α-chloralose were used. RESULTS: Pilocarpine (500nmol/1μl) injected i.c.v. Reduced SSG vascular resistance and increased arterial pressure, heart rate and mesenteric vascular resistance. Contrary to pilocarpine alone, the combination of moxonidine (20nmol/1μl) and pilocarpine injected i.c.v. Increased SSG vascular resistance, an effect abolished by the pre-treatment with the α(2)-adrenoceptor antagonist yohimbine (320nmol/2μl). The increase in arterial pressure, heart rate and mesenteric resistance was not modified by the combination of moxonidine and pilocarpine i.c.v. CONCLUSION: These results suggest that the activation of central α(2)-adrenoceptors may oppose to the effects of central cholinergic receptor activation in the SSG vascular resistance.

Increased SGLT1 expression in salivary gland ductal cells correlates with hyposalivation in diabetic and hypertensive rats

Background Oral health complications in diabetes and hypertension include decreased salivary secretion. The sodium-glucose cotransporter 1 (SGLT1) protein, which transports 1 glucose/2 Na+/264 H2O molecules, is described in salivary glands. We hypothesized that changes in SGLT1 expression in the luminal membrane of ductal cell may be related to an altered salivary flow. Findings By immunohistochemistry, we investigated SGLT1 expression in ductal cells of parotid and submandibular glands from Wistar Kyoto rats (WKY), diabetic WKY (WKY-D), spontaneously hypertensive rats (SHR) and diabetic SHR (SHR-D), as well as in parotid glands from WKY subjected to sympathetic stimulation, with or without previous propranolol blockade. Diabetes and hypertension decreased the salivary secretion and increased SGLT1 expression in the luminal membrane of ductal cells, and their association exacerbated the regulations observed. After 30 min of sympathetic stimulation, SGLT1 increased in the luminal membrane of ductal cells, and that was blocked by previous injection of propranolol. Conclusions SGLT1 expression increases in the luminal membrane of salivary gland ductal cells and the salivary flow decreases in diabetic and hypertensive rats, which may be related to sympathetic activity. This study highlights the water transporter role of SGLT1 in salivary glands, which, by increasing ductal water reabsorption, may explain the hyposalivation of diabetic and hypertensive subjects

Advanced Lemierre syndrome requiring surgery

A 38-year-old homeless man was admitted with a 2-week history of a sore throat, increasing shortness of breath, and high fever. Clinical examination showed enlarged and tender submandibular and anterior cervical lymph nodes and a pronounced enlargement of the left peritonsillar region (Figure 1a). CT scan of the throat and the chest showed left peritonsillar abscess formation, occlusion of the left internal jugular vein with inflammatory wall thickening and perijugular soft tissue infiltration, pulmonary abscesses, and bilateral pleural effusions (Figures 1b-e, arrowed). Anaerobe blood cultures grew Fusobacterium necrophorum, leading to the diagnosis of Lemierre's syndrome. Treatment with high-dose amoxicillin and clavulanic acid improved the oropharyngeal condition, but the patient's general status declined further, marked by dyspnea and tachypnea. Repeated CT scans showed progressive lung abscesses and bilateral pleural empyema. Bilateral tonsillectomy, ligation of the left internal jugular vein, and staged decortication of bilateral empyema were performed. Total antibiotic therapy duration was 9 weeks, including a change to peroral clindamycin. Clinical and laboratory findings had returned to normal 12 weeks after surgery.The patient's history and the clinical and radiological findings are characteristic for Lemierre's syndrome. CT scans of the neck and the chest are the diagnostic methods of choice. F. necrophorum is found in over 80% of cases of Lemierre's syndrome and confirms the diagnosis. Prolonged antibiotic therapy is usually sufficient, but in selected patients, a surgical intervention may be necessary. Reported mortality rates are high, but in surviving patients, the recovery of pulmonary function is usually good.

Intussusceptive microvascular growth: a common alternative to capillary sprouting.

Intussusceptive capillary growth represents a new principle for microvascular growth as described in the lungs of growing rats. According to this concept, the capillary network expands by the formation of slender transcapillary tissue pillars, which give rise to new vascular meshes. The process was first observed in Mercox casts of the lung microvasculature, which revealed the existence of multiple tiny holes with diameters around 1.5 microns. Consecutive transmission electron microscopic investigation of serial sections demonstrated that the holes corresponded to slender tissue pillars (Burri and Tarek, 1990). The corrosion cast technique thus appears to be an adequate screening method for intussusceptive growth. In the present investigation, Mercox casts of various vascular systems, namely, those of the eye, submandibular gland, heart, liver, stomach, small and large intestine, trachea, kidney, uterus and ovary were prepared from rats aged between 4 and 9 weeks in order to screen them for the existence of the typical tiny holes representing tissue pillars. In all organs investigated, these structures were observed in various locations to a variable degree. They were mainly encountered within dilated vascular segments or at triple or quadruple branching points of the circulation. Even in capillary networks with a three-dimensional arrangement could these pillars be detected. Intussusception thus appears to be a principle of growth appertaining to many vascular systems.

Induction of ovulation in rabbit does using purified nerve growth factor and camel seminal plasma

The presence of an ovulation-inducing factor (OIF) in the seminal plasma (SP) of several species with spontaneous and induced ovulation, including the rabbit, has been documented. Recent studies have demonstrated that the OIF in the SP of camels (SPCAM) is a nerve growth factor (β-NGF). The aim of this study was to determine if purified β-NGF from mouse submandibular glands or SPCAM could provoke ovulation induction in the rabbit doe. A total of 35 females were synchronized with 25 IU of equine chorionic gonadotropin (Serigan, Laboratorios Ovejero, Spain) and allocated into 4 groups. Forty-eight hours later (Day 0), does were given a single dose (IM) of 1 mL of saline solution (SS; n = 8); 1 mL of gonadorelin (GnRH; Inducel, Laboratorios Ovejero, Spain; n = 9); 24 µg of β-NGF (2.5S-NGF; Promega, USA; n = 10); or 1 mL of centrifuged raw camel SP (SPCAM; 127 pg mL–1 NGF; n = 8). After treatment, an empty catheter was introduced through the vagina to simulate the nervous/mechanical stimulus of coitus (4 animals per group). Plasma LH concentrations were determined in blood samples taken 30 min before treatment and at 0, 30, 60, 90, and 120 min after injection. Progesterone concentrations were assessed at 0 and 120 min and every 2 days until Day 6 after treatment. Concentrations of β-NGF in camel SP and hormone determinations were made by enzyme immunoassay. Ovulation rate (OR) was determined after euthanasia on Day 7.

Transfer of human serum IgG to nonobese diabetic Igμnull mice reveals a role for autoantibodies in the loss of secretory function of exocrine tissues in Sjögren’s syndrome

The NOD (nonobese diabetic) mouse has been studied as an animal model for autoimmune insulin-dependent diabetes and Sjögren’s syndrome. NOD.Igμnull mice, which lack functional B lymphocytes, develop progressive histopathologic lesions of the submandibular and lachrymal glands similar to NOD mice, but in the absence of autoimmune insulitis and diabetes. Despite the focal appearance of T cells in salivary and lachrymal tissues, NOD.Igμnull mice fail to lose secretory function as determined by stimulation of the muscarinic/cholinergic receptor by the agonist pilocarpine, suggesting a role for B cell autoantibodies in mediating exocrine dryness. Infusion of purified serum IgG or F(ab′)2 fragments from parental NOD mice or human primary Sjögren’s syndrome patients, but not serum IgG from healthy controls, alters stimulated saliva production, an observation consistent with antibody binding to neural receptors. Furthermore, human patient IgG fractions competitively inhibited the binding of the muscarinic receptor agonist, [3H]quinuclidinyl benzilate, to salivary gland membranes. This autoantibody activity is lost after preadsorption with intact salivary cells. These findings indicate that autoantibodies play an important part in the functional impairment of secretory processes seen in connection with the autoimmune exocrinopathy of Sjögren’s syndrome.

Mice lacking DNA topoisomerase IIIβ develop to maturity but show a reduced mean lifespan

Targeted gene disruption in the murine TOP3β gene-encoding DNA topoisomerase IIIβ was carried out. In contrast to the embryonic lethality of mutant mice lacking DNA topoisomerase IIIα, top3β−/− nulls are viable and grow to maturity with no apparent defects. Mice lacking DNA topoisomerase IIIβ have a shorter life expectancy than their wild-type littermates, however. The mean lifespan of the top3β−/− mice is about 15 months, whereas that of their wild-type littermates is longer than 2 years. Mortality of the top3β−/− nulls appears to correlate with lesions in multiple organs, including hypertrophy of the spleen and submandibular lymph nodes, glomerulonephritis, and perivascular infiltrates in various organs. Because the DNA topoisomerase III isozymes are likely to interact with helicases of the RecQ family, enzymes that include the determinants of human Bloom, Werner, and Rothmund–Thomson syndromes, the shortened lifespan of top3β−/− mice points to the possibility that the DNA topoisomerase III isozymes might be involved in the pathogenesis of progeroid syndromes caused by defective RecQ helicases.

Prolactin increases CD4/CD8 cell ratio in thymus-grafted congenitally athymic nude mice.

One distinctive effect on T-cell development was analyzed by selectively increasing serum prolactin (PRL) concentration in thymus-grafted congenitally athymic nude mice and by neutralizing PRL in suspension cultures of thymus from 1-day-old neonatal mice. Flow cytometric analysis of single-positive CD4+ and CD8+ cells derived from inguinal lymph nodes revealed a CD4/CD8 cell ratio of 2.2 +/- 0.18 (mean +/- SEM) in thymus-grafted nude mice that is similar to the ratio for immune-competent BALB/c mice (2.0 +/- 0.06). Addition of the pituitary to thymus-grafted nude mice significantly elevated serum PRL (P < 0.005) and increased the CD4/CD8 cell ratio (2.8 +/- 0.12; P < 0.005), demonstrating preferential stimulation of CD4+ cell development. T cells in nude mice receiving sham (submandibular salivary gland) or pituitary grafts alone were below detectable levels. Suspension cultures of neonatal thymus treated with anti-mouse PRL antiserum resulted in 20% and 30% decreases in double-positive CD4+8+ thymocytes and thymocyte viability, respectively. A 10-fold increase in double-negative CD4-8- thymocytes expressing the interleukin 2 receptor alpha chain, CD25, was also observed concurrently. Our findings illustrate an important way in which PRL may participate in two interrelated mechanisms: the regulation of peripheral single-positive cells and the maintenance of thymocyte viability during the double-positive stage of intrathymic differentiation.

Revisiting a series of epithelial salivary gland tumors in children and adolescents in southern Portugal

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Endolymphatic sac tumor : A report of 2 cases with long term follow-up

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Growth hormone and epidermal growth factor in salivary glands of giant and dwarf transgenic mice

Epidermal growth factor (EGF) in rat salivary glands is regulated by testosterone, thyroxin, and growth hormone (GH). Salivary glands of 45-day-old giant and dwarf male and female transgenic mice were examined histologically and by immunohistochemistry (IHC) for EGF. Male giants showed no significant differences from wild-type (WT) parotid and submandibular glands. However, their sublingual glands expressed EGF diffusely and strongly in granular cells within the striated ducts, where they were not found in WT mice. Submandibular gland ducts of female WT were different, having individual granular cells strongly positive for EGF and distributed sporadically along the striated duct walls. Neither female GH-antagonist dwarf mice nor GH-receptor knockout mice had any granular cells expressing EGF in any gland. Obvious presence of granular duct cells in the sublingual glands of giant male mice suggests GH-upregulated granular cell EGF expression. Furthermore, absence of granular duct cells from all glands in female GH-antagonist and GH-receptor knockout transgenic mice suggests that GH is necessary for the differentiation of the granular cell phenotype in female salivary glands.

Calcium channels controlling acetylcholine release from preganglionic nerve terminals in rat autonomic ganglia

Little is known about the nature of the calcium channels controlling neurotransmitter release from preganglionic parasympathetic nerve fibres. In the present study, the effects of selective calcium channel antagonists and amiloride were investigated on ganglionic neurotransmission. Conventional intracellular recording and focal extracellular recording techniques were used in rat submandibular and pelvic ganglia, respectively. Excitatory postsynaptic potentials and excitatory postsynaptic currents preceded by nerve terminal impulses were recorded as a measure of acetylcholine release from parasympathetic and sympathetic preganglionic fibres following nerve stimulation. The calcium channel antagonists omega-conotoxin GVIA (N type), nifedipine and nimodipine (L type), omega-conotoxin MVIIC and omega-agatoxin IVA (P/Q type), and Ni2+ (R type) had no functional inhibitory effects on synaptic transmission in both submandibular and pelvic ganglia. The potassium-sparing diuretic, amiloride, and its analogue, dimethyl amiloride, produced a reversible and concentration-dependent inhibition of excitatory postsynaptic potential amplitude in the rat submandibular ganglion. The amplitude and frequency of spontaneous excitatory postsynaptic potentials and the sensitivity of the postsynaptic membrane to acetylcholine were unaffected by amiloride. In the rat pelvic ganglion, amiloride produced a concentration-dependent inhibition of excitatory postsynaptic currents without causing any detectable effects on the amplitude or configuration of the nerve terminal impulse. These results indicate that neurotransmitter release from preganglionic parasympathetic and sympathetic nerve terminals is resistant to inhibition by specific calcium channel antagonists of N-, L-, P/Q- and R-type calcium channels. Amiloride acts presynaptically to inhibit evoked transmitter release, but does not prevent action potential propagation in the nerve terminals, suggesting that amiloride may block the pharmacologically distinct calcium channel type(s) on rat preganglionic nerve terminals. (C) 1999 IBRO. Published by Elsevier Science Ltd.

VIP and PACAP potentiation of nicotinic ACh-evoked currents in rat parasympathetic neurons is mediated by G-protein activation

The effects of vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP27 and PACAP38) on isolated parasympathetic neurons of rat intracardiac and submandibular ganglia were examined under voltage clamp using whole-cell patch-clamp recording techniques. VIP and PACAP (less than or equal to 10 nm) selectively and reversibly increased the affinity of nicotinic acetylcholine receptor channels (nAChRs) for their agonists resulting in a potentiation of acetylcholine (ACh)-evoked whole-cell currents at low agonist concentrations. VIP-induced potentiation was observed with either ACh or nicotine as the cholinergic agonist. The VIP- but not the PACAP-induced potentiation of ACh-evoked currents was inhibited by [Ac-Tyr(1), D-Phe(2)]-GRF 1-29, amide (100 nm), a selective antagonist of VPAC(1) and VPAC(2) receptors; whereas the PACAP38- but not the VIP-induced potentiation was inhibited by 100 nm PACAP6-38, a PAC(1) and VPAC(2) receptor antagonist. The signal transduction pathway mediating VIP- and PACAP-induced potentiation of nicotinic ACh-evoked currents involves a pertussis toxin (PTX)-sensitive G-protein. Intracellular application of 200 mu m GTP gamma S or GDP beta S inhibited VIP-induced potentiation of ACh-evoked whole-cell currents. GTP gamma S alone potentiated ACh- and nicotine-evoked currents and the magnitude of these currents was not further increased by VIP or PACAP. The G-protein subtype modulating the neuronal nAChRs was examined by intracellular dialysis with antibodies directed against alpha(o), alpha(i-1,2), alpha(i-3) or beta G-protein subunits. Only the anti-G alpha(o) and anti-G beta antibodies significantly inhibited the effect of VIP and PACAP on ACh-evoked currents. The potentiation of ACh-evoked currents by VIP and PACAP may be mediated by a membrane-delimited signal transduction cascade involving the PTX-sensitive G(o) protein.