The response of native Australian rodents to predator odours varies seasonally: a by-product of life history variation?

Small mammals are subject to predation from mammalian, avian and reptilian predators. There is an obvious advantage for prey species to detect the presence of predators in their environment, enabling them to make decisions about movement and foraging behaviour based on perceived risk of predation. We examined the effect of faecal odours from marsupial and eutherian predators, and a native reptilian predator, on the behaviour of three endemic Australian rodent species (the fawn-footed melomys, Melomys cervinipes, the bush rat, Rattus fuscipes, and the giant white-tailed rat, Uromys caudimaculatus) in rainforest remnants on the Atherton Tableland, North Queensland, Australia. Infrared camera traps were used to assess visit rates of rodents to odour stations containing faecal and control odours. Rodents avoided odour stations containing predator faeces, but did not avoid herbivore or control odours. The responses of the three prey species differed: in the late wet season U. caudimaculatus avoided predator odours, whereas R. fuscipes and M. cervinipes did not. In contrast, in the late dry season all three species avoided odour stations containing predator odours. We speculate that these different responses may result from variation in life history traits between the species. (c) 2006 The Association for the Study of Animal Behaviour Published by Elsevier Ltd. All rights reserved.

Ovarian necrotizing vasculitis in a patient with lupus

Ovarian vasculitis is a rare complication seen in the reproductive system and has been described in only one patient with lupus and a few patients with other rheumatic conditions (polyarteritis nodosa, giant cell arteritis, scleroderma). Three additional cases following gynecology procedures have also been reported. We report the second case of a patient with systemic lupus erythematosus, who developed ovarian vasculitis. The diagnosis was made at the age of 12 and confirmed by laparoscopy and histopathology in the presence of disease activity. She experienced late menarche at the age of 16, and she experienced a good clinical evolution after disease treatment with regular menstrual cycles and normal levels of sexual hormones. Lupus (2009) 18, 1313-1315.

Expression of constitutively activated human c-Kit in myb transformed early myeloid cells leads to factor independence, histiocytic differentiation, and tumorigenicity

The cDNAs encoding wild type (WT) human receptor tyrosine kinase c-Kit and a constitutively activated mutant, V816Kit, were introduced into granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent early murine hemopoietic cells, which had been transformed with activated Myb, WTKit cells were able to grow in the presence of the human ligand for Kit, stem cell factor (SCF), but displayed reduced growth and clonogenic potential in either SCF or GM-CSF compared with the parental cells in GM-CSF. In contrast, V816Kit cells grew without factor at a higher rate than the parental cells in GM-CSF and displayed increased clonogenicity. Dissection of the growth characteristics in liquid culture showed that in the presence of appropriate factors, the different populations had similar proliferation rates, but that V816Kit profoundly increased cell survival compared with WTKit or parental cells, This suggests that the signals transduced by WTKit activated with SCF, and by V816Kit, were not identical. Also, WTKit and V816Kit-expressing cells both varied from the early myeloid progenitor phenotype of the parental cells and gave rise to a small number of large to giant adherent cells that expressed macrophage (alpha-naphthyl acetate) esterase and neutrophil (naphtol-AS-D-chloroacetate) esterase, were highly phagocytic and phenotypically resembled histiocytes. Thus, WTKit activated by SCF and V816Kit were able to induce differentiation in a proportion of Myb-transformed myeloid cells. The factor independent V816Kit cells, unlike the parental and WTKit expressing cells, were shown to produce tumors of highly mitotic, invasive cells at various stages of differentiation in syngeneic mice. These results imply that constitutively activated Kit can promote the development of differentiated myeloid tumors and that its oncogenic effects are not restricted to lineages (mast cell and B-cell acute lymphoblastic leukemia), which have been reported previously. Furthermore, the mixed populations of cells in culture and in the tumors phenotypically resembled the leukemic cells from patients with monocytic leukemia with histiocytic differentiation (acute myeloid leukemia-M5c), a newly proposed subtype of myeloid leukemia. (C) 1997 by The American Society of Hematology.

Immunohistochemical study of Langerhans cells in cutaneous lesions of the Jorge Lobo`s disease

Jorge Lobo`s disease is a chronic infection caused by the fungus Lacazia loboi endemic in South America. The infection is characterized by the appearance of parakeloidal, ulcerated or verrucous nodular or plaque-like cutaneous lesions. The histopathological aspect is characterized by poorly organized granulomas with histiocytes and multinucleated giant cells. Little is known about local immune response in lobomycosis skin lesions. Thirty-three skin biopsies from patients with Jorge Lobo`s disease were selected from Ambulatory of Dermatology, UFPA. The control group was constituted by ten biopsies from normal skin. Langerhans cells were identified by immunohistochemistry using anti-CD1a antibody (Serotec). The number of positive cells was statistically analyzed. Langerhans cells were visualized along the epidermis in biopsies from Jorge Lobo`s disease and the morphology and the number of Langerhans cells did not differ from normal skin (p > 0.05). In Jorge Lobo`s disease, this cell population probably presents some escape mechanism of the local immune system to evade the antigen presentation by those cells. (C) 2010 Published by Elsevier B.V.

High-Resolution Genomic Mapping Reveals Consistent Amplification of the Fibroblast Growth Factor Receptor Substrate 2 Gene in Well-Differentiated and Dedifferentiated Liposarcoma

Well-differentiated liposarcoma (WDLS) is one of the most common malignant mesenchymal tumors and dedifferentiated liposarcoma (DDLS) is a malignant tumor consisting of both WDLS and a transformed nonlipogenic sarcomatous component. Cytogenetically, WDLS is characterized by the presence of ring or giant rod chromosomes containing several amplified genes, including MDM2, TSPAN31 CDK4, and others mainly derived from chromosome bands 12q13-15. However, the 12q13-15 amplicon is large and discontinuous. The focus of this study was to identify novel critical genes that are consistently amplified in primary (nonrecurrent) WDLS and with potential relevance for future targeted therapy. Using a high-resolution (5.0 kb) ""single nucleotide polymorphism""/copy number variation microarray to screen the whole genome in a series of primary WDLS, two consistently amplified areas were found on chromosome 12: one region containing the MDM2 and CPM genes, and another region containing the FRS2 gene. Based on these findings, we further validated FRS2 amplification in both WDLS and DDLS. Fluorescence in situ hybridization confirmed FRS2 amplification in all WDLS and DDLS tested (n = 57). Real time PCR showed FRS2 mRNA transcriptional upregulation in WDLS (n = 19) and DDLS (n = 13) but not in lipoma (n = 5) and normal fat (n = 9). Immunoblotting revealed high expression levels of phospho-FRS2 at 1436 and slightly overexpression of total FRS2 protein in liposarcoma but not in normal fat or preadipocytes. Considering the critical role of FRS2 in mediating fibroblast growth factor receptor signaling, our findings indicate that FRS2 signaling should be further investigated as a potential therapeutic target for liposarcoma. (C) 2011 Wiley-Liss, Inc.

Anaplastic Thyroid Carcinoma Morphologic Findings and PAX-8 Expression in Cytology Specimens

Objective To evaluate the morphologic findings most encountered in anaplastic thyroid carcinomas (ATCs) and evaluate for the expression of PAX-8. Study Design The cytology specimens from 21 cases of ATC were evaluated for the following several cytologic criteria, cell morphology, pleomorphism, presence or absence of multinucleated cells, neutrophilic infiltrate and well-differentiated component. Immunohistochemical studies for PAX-8 were performed on cell blocks in selected cases. Results The most common morphology present was epithelioid, followed by spindle, multinucleated giant cell and rhabdoid, with 75% demonstrating more than 1 cell morphology. Marked pleomorphism (81%), neutrophilic infiltrate (90%) and necrosis (63%) were frequent. No nuclear grooves, colloid or well-differentiated component was idenrifled in any case. Immunocytochemical stains for PAX-8 were negative in 5 cases in which a cell block was available. Conclusion ATC is a tumor with diverse morphologic characteristics, and more than 1 cell morphology is usually present A neutrophilic infiltrate is a common finding and represents a clue to the correct diagnosis. (Acta Cytol 2010;54:668-672)

EVALUATION OF ONYX HD-500 EMBOLIC SYSTEM IN THE TREATMENT OF 84 WIDE-NECK INTRACRANIAL ANEURYSMS

OBJECTIVE: We report our results using Onyx HD-500 (Micro Therapeutics, Inc., Irvine, CA) in the endovascular treatment of wide-neck intracranial aneurysms, which have a high rate of incomplete occlusion and recanalization with platinum coils. METHODS: Sixty-nine patients with 84 aneurysms were treated. Most of the aneurysms were located in the anterior circulation (80 of 84 aneurysms), were unruptured (74 of 84 aneurysms), and were incidental. Ten presented with subarachnoid hemorrhage, and 15 were symptomatic. All aneurysms had wide necks (neck >4 mm and/or dome-to-neck ratio <1.5). Fifty aneurysms were small (<12 mm), 30 were large (12 to <25 mm) and 4 were giant. Angiographic follow-up was available for 65 of the 84 aneurysms at 6 months, for 31 of the 84 aneurysms at 18 months, and for 5 of the 84 aneurysms at 36 months. RESULTS: Complete aneurysm occlusion was seen in 65.5% of aneurysms on immediate control, in 84.6% at 6 months, and in 90.3% at 18 months. The rates of complete occlusion were 74%, 95.1%, and 95.2% for small aneurysms and 53.3%, 70%, and 80% for large aneurysms at the same follow-up periods. Progression from incomplete to complete occlusion was seen in 68.2% of all aneurysms, with a higher percentage in small aneurysms (90.9%). Aneurysm recanalization was observed in 3 patients (4.6%), with retreatment in 2 patients (3.3%). Procedural mortality was 2.9%. Overall morbidity was 7.2%. CONCLUSION: Onyx embolization of intracranial wide-neck aneurysms is safe and effective. Morbidity and mortality rates are similar to those of other current endovascular techniques. Larger samples and longer follow-up periods are necessary.

Gingival juvenile xanthogranuloma in an adult patient: case report with immunohistochemical analysis and literature review

Juvenile xanthogranuloma (JXG) is a non-Langerhans cell histiocytosis (nonLCH). It is a benign and self-healing disorder that generally affects infants and children. Oral lesions in adult patients are rare, although the microscopic findings are similar to those observed in other locations. A 56-year-old white man presented with a chief complaint of a gingival mass that had appeared 6 months before and had grown slowly. An intraoral examination revealed the presence of a solitary, softened gingival mass affecting the mandibular lingual gingiva at the right central incisor area. A biopsy of the lesion showed multiple large macrophages and numerous giant cells of Touton type. The immunohistochemistry positivity for CD68, fascin, factor XIIIa, alpha-antitrypsin and negativity for S-100, beta-actin, CD1a, and desmin confirmed the diagnosis of JXG. The occurrence of adult oral JXG is extremely rare. It is a nonLCH that may present variable clinical and microscopic aspects, which leads to a diversity of clinical misdiagnoses. A precise diagnosis of these lesions requires an accurate evaluation of clinical, microscopic, and immunohistochemical features.

Percutaneous Laser Ablation of Sacrococcygeal Teratoma in a Hydropic Fetus with Severe Heart Failure - Too Late for a Surgical Procedure?

Sacrococcygeal teratoma (SCT) is the commonest solid fetal tumor. Perinatal prognosis is usually favorable, but sometimes it can be complicated by fetal hydrops being responsible for high risk of mortality. Fetal therapy in such cases has so far not been established. We report a case with a giant solid SCT associated with fetal hydrops and severe heart failure. 2D- and 3D-Doppler ultrasonography revealed great vessels originated from the medial sacral artery. Percutaneous laser ablation of these vessels was performed at 24 weeks of gestation. During the procedure, severe anemia was also diagnosed (hemoglobin 4.3 g/dl). Two days later, the fetus died and pathological examination revealed local tumor necrosis and blood hemorrhage inside the mass. We suggest that in such cases, fetal surgery may not be enough, being too late, and perhaps fetal clinical therapy for anemia and heart failure could be the best option at a gestational age of less than 28 weeks. Copyright (C) 2009 S. Karger AG, Basel

Disseminated blue naevus and malignant blue naevus associated with excessive aromatase syndrome

We report a case of a 17-year-old boy who had a giant congenital blue naevus with multiple satellite pigmented lesions. Later the patient developed melanoma arising in the pre-existing lesion. He also had gynaecomastia and was diagnosed as having aromatase excess syndrome. To our knowledge, the association of these two rare conditions has not been previously reported. Further studies should be performed to investigate this unusual combination, which may have a genetic, endocrine or local cutaneous link leading to its occurrence.

Conus perimedullary arteriovenous fistula in a child: unusual angio-architectural features and pathophysiology

Introduction The perimedullary arteriovenous fistulas are located on the pial surface and are usually supplied by spinal medullary arteries, that is, either by the anterior or posterior spinal arteries, with no intervening nidus between the feeder arteries and the venous drainage. The clinical findings are, more commonly, caused by progressive radiculomedullary ischemic processes secondary to steal vascular mechanism. As the vascular supply to the spinal cord and to the arteriovenous fistulas (AVF) is not shared with one another, the vascular steal phenomenon cannot be implicated in this case`s physiopathology. Most probably, the mass effect caused by the giant venous dilatation was the pathophysiological mechanism involved in this lesion Case report The authors describe the case of a 6-year-old girl with an intradural ventral arteriovenous fistula, with a giant venous dilatation, fed directly by L2 and L3 radiculomedullary arteries at the conus medullaris. There was no arterial supply to the fistula from the anterior or posterior spinal arteries. Selective spinal angiography showed an arteriovenous fistula supplied directly by two radiculomedullary arteries, with a large draining vein caudally. Interposing the arterial and venous vessels was a giant venous aneurysmal dilatation located ventral to the conus medullaris and extending from L3 to T6. The patient was successfully treated by a surgical approach through a laminotomy from L3 to T11. Conclusion The type IV-C spinal arteriovenous malformations or perimedullary AVFs are rare lesions predominately described at the conus medullaris with various types of angio-architecture and controversial treatment.

Prelimbic but not infralimbic cortex is involved in the pressor response to chemoreflex activation in awake rats

The ventral portion of the medial prefrontal cortex comprises the prelimbic cortex (PL) and the infralimbic cortex (IL). Several studies have indicated that both the PL and the IL play an important role in cardiovascular control. Chemoreflex activation by systemic administration of potassium cyanide (KCN) evokes pressor and bradycardiac responses in conscious rats, in addition to an increase in respiratory frequency. We report here a comparison between the effects of pharmacological inhibition of PL and IL neurotransmission on blood pressure and heart rate responses evoked by chemoreflex activation using KCN (i.v.) in conscious rats. Bilateral microinjection of 200 nl of the unspecific synaptic blocker CoCl(2) (1 mm) into the PL evoked a significant attenuation of the pressor response, without affecting the chemoreflex-induced heart rate decrease. However, IL local synapse inhibition evoked no changes in cardiovascular responses induced by chemoreflex activation. Thus, our results suggest that the pressor but not the bradycardiac response to chemoreflex activation is, at least in part, mediated by local neurotransmission present in the PL cortex, without influence of the IL cortex.

Anxiolytic-like effects induced by acute reversible inactivation of the bed nucleus of stria terminalis

There is conflicting evidence concerning the role of the bed nucleus of the stria terminalis (BNST) in fear and anxiety-elicited behavior. Most of the studies investigating this role, however, employed irreversible lesions of this nucleus. The objective of the present study was to investigate the effects of an acute and reversible inactivation of the BNST in rats submitted to the Vogel conflict test (VCT) and contextual fear conditioning, two widely employed animal models that are responsive to prototypal anxiolytic drugs. Male Wistar rats were submitted to stereotaxic surgery to bilaterally implant cannulae into the BNST. Ten minutes before the test they received bilateral microinjections of cobalt chloride (COCl(2)) (1 mM/100 nL), a nonselective synapse blocker. COCl(2) produced anxiolytic-like effects in tests, increasing the number of punished licks in the VCT and decreasing freezing behavior and the increase in mean arterial blood pressure and heart rate of animals re-exposed to the context where they had received electrical foot shocks 24 h before. The results indicate that the BNST is engaged in behavioral responses elicited by punished stimuli and aversively conditioned contexts, reinforcing its proposed role in anxiety. (C) 2008 IBRO. Published by Elsevier Ltd. All rights reserved.

Effects of reversible inactivation of the dorsal hippocampus on the behavioral and cardiovascular responses to an aversive conditioned context

In rats, conditioned fear to context causes freezing immobility and cardiovascular changes. The dorsal hippocampus (DH) has a critical role in several memory processes, including conditioning fear to contextual information. To explore a possible involvement of the DH in contextual fear conditioning-evoked cardiovascular (mean arterial pressure and heart rate increases) and behavioral (freezing) responses, DH synaptic transmission was temporarily inhibited by bilateral microinjections of 500 nl of the nonselective synapse blocker, cobalt chloride (COCl2, 1 mmol/l), at different periods of the experimental procedure. During re-exposure to the foot shock chamber in which conditioning had taken place, bilateral DH inhibition 10 min before the conditioning session had no effect on either behavioral or cardiovascular responses. Bilateral DH inhibition immediately after the conditioning session (110 min) decreased both behavioral and cardiovascular responses during the context test. Finally, 48 h after the conditioning session, bilateral DH inhibition 10 min before re-exposure to the foot shock chamber significantly reduced cardiovascular responses but not freezing responses. These results suggest that contextual fear conditioning acquisition does not depend on the DH. This structure, however, is crucial for the consolidation of contextual fear. Moreover, although the DH appears to be less important for the behavioral (freezing) changes induced by re-exposure to the aversive conditioned context, it may play an important role on the cardiovascular responses generated by this model.

A novel role for MNTB neuron dendrites in regulating action potential amplitude and cell excitability during repetitive firing

Principal cells of the medial nucleus of the trapezoid body (MNTB) are simple round neurons that receive a large excitatory synapse (the calyx of Held) and many small inhibitory synapses on the soma. Strangely, these neurons also possess one or two short tufted dendrites, whose function is unknown. Here we assess the role of these MNTB cell dendrites using patch-clamp recordings, imaging and immunohistochemistry techniques. Using outside-out patches and immunohistochemistry, we demonstrate the presence of dendritic Na(+) channels. Current-clamp recordings show that tetrodotoxin applied onto dendrites impairs action potential (AP) firing. Using Na(+) imaging, we show that the dendrite may serve to maintain AP amplitudes during high-frequency firing, as Na(+) clearance in dendritic compartments is faster than axonal compartments. Prolonged high-frequency firing can diminish Na(+) gradients in the axon while the dendritic gradient remains closer to resting conditions; therefore, the dendrite can provide additional inward current during prolonged firing. Using electron microscopy, we demonstrate that there are small excitatory synaptic boutons on dendrites. Multi-compartment MNTB cell simulations show that, with an active dendrite, dendritic excitatory postsynaptic currents (EPSCs) elicit delayed APs compared with calyceal EPSCs. Together with high- and low-threshold voltage-gated K(+) currents, we suggest that the function of the MNTB dendrite is to improve high-fidelity firing, and our modelling results indicate that an active dendrite could contribute to a `dual` firing mode for MNTB cells (an instantaneous response to calyceal inputs and a delayed response to non-calyceal dendritic excitatory postsynaptic potentials).