Nuclear organization of some immunohistochemically identifiable neural systems in two species of the Euarchontoglires: A Lagomorph,Lepus capensis,and a Scandentia,Tupaia belangeri

The present study describes the organization of the nuclei of the cholinergic, catecholaminergic, serotonergic and orexinergic systems in the brains of two members of Euarchontoglires, Lepus capensis and Tupaia belangeri. The aim of the present study was to investigate the nuclear complement of these neural systems in comparison to previous studies on Euarchontoglires and generally with other mammalian species. Brains were coronally sectioned and immunohistochemically stained with antibodies against choline acetyltransferase, tyrosine hydroxylase, serotonin and orexin-A. The majority of nuclei revealed in the current study were similar between the species investigated and to mammals generally, but certain differences in the nuclear complement highlight potential phylogenetic interrelationships within the Euarchontoglires and across mammals. In the northern tree shrew the nucleus of the trapezoid body contained neurons immunoreactive to the choline acetyltransferase antibody with some of these neurons extending into the lamellae within the superior olivary nuclear complex (SON). The cholinergic nature of the neurons of this nucleus, and the extension of cholinergic neurons into the SON, has not been noted in any mammal studied to date. In addition, cholinergic neurons forming the medullary tegmental field were also present in the northern tree shrew. Regarding the catecholaminergic system, the cape hare presented with the rodent specific rostral dorsal midline medullary nucleus (C3), and the northern tree shrew lacked both the ventral and dorsal divisions of the anterior hypothalamic group (A15v and A15d). Both species were lacking the primate/megachiropteran specific compact portion of the locus coeruleus complex (A6c). The nuclei of the serotonergic and orexinergic systems of both species were similar to those seen across most Eutherian mammals. Our results lend support to the monophyly of the Glires, and more broadly suggest that the megachiropterans are more closely related to the primates than are any other members of Euarchontoglires studied to date.     

Electromagnetic field and brain development

Rapid advances in technology involve increased exposures to radio-frequency/microwave radiation from mobile phones and other wireless transmitting devices. As cell phones are held close to the head during talking and often stored next to the reproductive organs, studies are mostly focused on the brain. In fact, more research is especially needed to investigate electromagnetic field (EMF)’s effects on the central nervous system (CNS). Several studies clearly demonstrate that EMF emitted by cell phones could affect a range of body systems and functions. Recent work has demonstrated that EMF inhibit the formation and differentiation of neural stem cells during embryonic development and also affect reproductive and neurological health of adults that have undergone prenatal exposure. The aim of this review is to discuss the developing CNS and explain potential impacts of EMF on this system.     

Projections from the rat cuneiform nucleus to the A7, A6 (locus coeruleus), and A5 pontine noradrenergic cell groups

Stimulation of neurons in the cuneiform nucleus (CnF) produces antinociception and cardiovascular responses that could be mediated, in part, by noradrenergic neurons that innervate the spinal cord dorsal horn. The present study determined the projections of neurons in the CnF to the pontine noradrenergic neurons in the A5, A6 (locus coeruleus), and A7 cell groups that are known to project to the spinal cord. Injections of the anterograde tracer, biotinylated dextran amine in the CnF of Sasco Sprague-Dawley rats labeled axons located near noradrenergic neurons that were visualized by processing tissue sections for tyrosine hydroxylase-immunoreactivity. Anterogradely labeled axons were more dense on the side ipsilateral to the BDA deposit. Both A7 and A5 cell groups received dense projections from neurons in the CnF, whereas locus coeruleus received only a sparse projection. Highly varicose anterogradely labeled axons from the CnF were found in close apposition to dendrites and somata of tyrosine hydroxylase-immunoreactive neurons in pontine tegmentum. Although definitive evidence for direct pathways from CnF neurons to the pontine noradrenergic cell groups requires ultrastructural analysis, the results of the present studies provide presumptive evidence of direct projections from neurons in the CnF to the pontine noradrenergic neurons of the A7, locus coeruleus, and A5 cell groups. These results support the suggestion that the analgesia and cardiovascular responses produced by stimulation of neurons in the CnF may be mediated, in part, by pontine noradrenergic neurons.     

Distribution of methionine-enkephalin in the minipig brainstem

We have studied the distribution of immunoreactive cell bodies and axons are containing methionine-enkephalin in the minipig brainstem. Immunoreactive axons were widely distributed, whereas the distribution of perikarya was less widespread. A high or moderate density of axons containing methionine-enkephalin were found from rostral to caudal levels in the substantia nigra, nucleus interpeduncularis, nucleus reticularis tegmenti pontis, nucleus dorsalis raphae, nucleus centralis raphae, nuclei dorsalis and ventralis tegmenti of Gudden, locus ceruleus, nucleus sensorius principalis nervi trigemini, nucleus cuneatus externalis, nucleus tractus solitarius, nuclei vestibularis inferior and medialis, nucleus ambiguus, nucleus olivaris inferior and in the nucleus tractus spinalis nervi trigemini. Immunoreactive perikarya were observed in the nuclei centralis and dorsalis raphae, nucleus motorius nervi trigemini, nucleus centralis superior, nucleus nervi facialis, nuclei parabrachialis medialis and lateralis, nucleus ventralis raphae, nucleus reticularis lateralis and in the formatio reticularis. We have also described the presence of perikarya containing methionine-enkephalin in the nuclei nervi abducens, ruber, nervi oculomotorius and nervi trochlearis. These results suggest that in the minipig the pentapeptide may be involved in many physiological functions (for example, proprioceptive and nociceptive information; motor, respiratory and cardiovascular mechanisms).     

The centrally projecting Edinger–Westphal nucleus—I: Efferents in the rat brain

The oculomotor accessory nucleus, often referred to as the Edinger–Westphal nucleus [EW], was first identified in the 17th century. Although its most well known function is the control of pupil diameter, some controversy has arisen regarding the exact location of these preganglionic neurons. Currently, the EW is thought to consist of two different parts. The first part [termed the preganglionic EW—EWpg], which controls lens accommodation, choroidal blood flow and pupillary constriction, primarily consists of cholinergic cells that project to the ciliary ganglion. The second part [termed the centrally projecting EW—EWcp], which is involved in non-ocular functions such as feeding behavior, stress responses, addiction and pain, consists of peptidergic neurons that project to the brainstem, the spinal cord and prosencephalic regions. However, in the literature, we found few reports related to either ascending or descending projections from the EWcp that are compatible with its currently described functions. Therefore, the objective of the present study was to systematically investigate the ascending and descending projections of the EW in the rat brain. We injected the anterograde tracer biotinylated dextran amine into the EW or the retrograde tracer cholera toxin subunit B into multiple EW targets as controls. Additionally, we investigated the potential EW-mediated innervation of neuronal populations with known neurochemical signatures, such as melanin-concentrating hormone in the lateral hypothalamic area [LHA] and corticotropin-releasing factor in the central nucleus of the amygdala [CeM]. We observed anterogradely labeled fibers in the LHA, the reuniens thalamic nucleus, the oval part of the bed nucleus of the stria terminalis, the medial part of the central nucleus of the amygdala, and the zona incerta. We confirmed our EW–LHA and EW–CeM connections using retrograde tracers. We also observed moderate EW-mediated innervation of the paraventricular nucleus of the hypothalamus and the posterior hypothalamus. Our findings provide anatomical bases for previously unrecognized roles of the EW in the modulation of several physiologic systems.     

Effect of low estrogen on neurons in the preoptic area of hypothalamus of ovariectomized rats

The purpose of this study was to investigate the difference in neuronal activity in the preoptic area of the hypothalamus (POAH) under low estrogen condition induced by ovariectomy. One hundred and twenty sham-operated (SHAM) and ovariectomized (OVX) rats were placed in different temperatures for 2 h. Twelve rats from each group were stimulated by 4 °C, 10 °C, 25 °C, 33 °C and 38 °C, respectively. c-Fos expression in the POAH was detected by immunohistochemistry. Following exposure to warm and cold stimuli, there were markedly lower c-Fos-positive cell densities in the OVX group compared with the SHAM group in the median preoptic nucleus (MnPO) at 4 °C, 10 °C, 33 °C and 38 °C, in the medial preoptic area (MPA) at 25 °C and 38 °C, in the ventromedial preoptic nucleus (VMPO) at 4 °C, 10 °C and 38 °C and in the ventrolateral preoptic nucleus (VLPO) at 4 °C and 38 °C. Both temperature and surgery had an impact on c-Fos expression by two-way ANOVA method except in the lateral preoptic area (LPO). c-Fos expression differed within different nuclei of the two groups in the same and different temperature stimuli. This indicated that the temperature-sensitive nuclei in the POAH exhibited lower and different activities during temperature stimuli following ovariectomy, which possibly resulted in abnormal thermoregulation and menopausal symptoms.     

The respiratory cycle modulates brain potentials,sympathetic activity,and subjective pain sensation induced by noxious stimulation

To test the hypothesis that a respiratory cycle influences pain processing, we conducted an experimental pain study in 10 healthy volunteers. Intraepidermal electrical stimulation (IES) with a concentric bipolar needle electrode was applied to the hand dorsum at pain perceptual threshold or four times the perceptual threshold to produce first pain during expiration or inspiration either of which was determined by the abrupt change in an exhaled CO₂ level. IES-evoked potentials (IESEPs), sympathetic skin response (SSR), digital plethysmogram (DPG), and subjective pain intensity rating scale were simultaneously recorded. With either stimulus intensity, IES during expiration produced weaker pain feeling compared to IES during inspiration. The mean amplitude of N200/P400 in IESEPs and that of SSR were smaller when IES was applied during expiration. The magnitude of DPG wave gradually decreased after IES, but a decrease in the magnitude of DPG wave was less evident when IES was delivered during expiration. Regardless of stimulus timing or stimulus intensity, pain perception was always concomitant with appearance of IESEPs and SSR, and changes in DPG. Our findings suggest that pain processing fluctuates during normal breathing and that pain is gated within the central nervous system during expiration.     

Mutations in rpoB gene and rifabutin susceptibility of multidrug-resistant Mycobacterium tuberculosis strains isolated in Australia.

Control of tuberculosis, the single largest killer among the infectious diseases, has been threatened by the emergence of multidrug-resistant Mycobacterium tuberculosis (MDRTB) infection due to the limited treatment options. Rifampicin (RIF) resistance is considered as a marker for MDRTB. The aim of this study was the detection of rpoB gene mutations and rifabutin resistance in MDRTB strains recently isolated in Australia by a line probe assay (INNO-LiPA Rif. TB, Innogenetics). Rifabutin and RIF susceptibility of 20 MDRTB and 16 RIF-sensitive M. tuberculosis complex clinical isolates were studied. The overall concordance of the line probe assay (LiPA) with phenotypic RIF susceptibility test was 96%. Seven distinct nucleotide substitutions were identified in 21 of 22 RIF-resistant isolates of diverse geographical origins, but in none of the RIF-sensitive strains. The majority (71%) of mutations occurred in the 526-533 codons and were associated with resistance to rifabutin and RIF. Of the RIF-resistant MDRTB strains, 18% appeared to be rifabutin-sensitive and produced delta S2 and delta S3 INNO-LiPA patterns. We conclude that amino acid substitutions at Asp516 and Ser522 in the rpoB gene in RIF-resistant M. tuberculosis predict rifabutin susceptibility for MDRTB. Use of the LiPA for RIF and rifabutin resistance may facilitate the rapid response required to limit the extent and severity of MDRTB transmission and infection.     

Effect of mobile telephony on blood-brain barrier permeability in the fetal mouse brain

AIMS: To study the effect of mobile telephone exposure on blood-brain barrier (BBB) permeability in the immature brain. METHODS: Using a purpose-designed exposure system at 900 MHz, pregnant mice were given a single, far-field, whole body exposure at a specific absorption rate of 4 W/kg for 60 min/day from day 1 to day 19 of gestation. Pregnant control mice were sham-exposed or freely mobile in a cage without further restraint and a positive control group with cadmium-induced BBB damage was also included. Immediately prior to parturition on gestational day 19, fetal heads were collected, fixed in Bouin's fixative and paraffin embedded. Disruption of BBB integrity was detected immunohistochemically using endogenous albumin as a vascular tracer in cerebral cortex, thalamus, basal ganglia, hippocampus, cerebellum, midbrain and medulla. RESULTS: No albumin extravasation was found in exposed or control brains. CONCLUSION: In this animal model, whole of gestation exposure to global system for mobile communication-like radiofrequency fields did not produce any increase in vascular permeability in the fetal brain regions studied using endogenous albumin as a light microscopic immunohistochemical marker.     

Subcellular localization and activation of ADAM proteases in the context of FasL shedding in T lymphocytes

The “A Disintegrin And Metalloproteinases” (ADAMs) form a subgroup of the metzincin endopeptidases. Proteolytically active members of this protein family act as sheddases and govern key processes in development and inflammation by regulating cell surface expression and release of cytokines, growth factors, adhesion molecules and their receptors. In T lymphocytes, ADAM10 sheds the death factor Fas Ligand (FasL) and thereby regulates T cell activation, death and effector function. Although FasL shedding by ADAM10 was confirmed in several studies, its regulation is still poorly defined. We recently reported that ADAM10 is highly abundant on T cells whereas its close relative ADAM17 is expressed at low levels and transiently appears at the cell surface upon stimulation. Since FasL is also stored intracellularly and brought to the plasma membrane upon stimulation, we addressed where the death factor gets exposed to ADAM proteases. We report for the first time that both ADAM10 and ADAM17 are associated with FasL-containing secretory lysosomes. Moreover, we demonstrate that TCR/CD3/CD28-stimulation induces a partial positioning of both proteases and FasL to lipid rafts and only the activation-induced raft-positioning results in FasL processing. TCR/CD3/CD28-induced FasL proteolysis is markedly affected by reducing both ADAM10 and ADAM17 protein levels, indicating that in human T cells also ADAM17 is implicated in FasL processing. Since FasL shedding is affected by cholesterol depletion and by inhibition of Src kinases or palmitoylation, we conclude that it requires mobilization and co-positioning of ADAM proteases in lipid raft-like platforms associated with an activation of raft-associated Src-family kinases.     

New immunomodulatory role of neuropeptide Y (NPY) in Salmo salar leucocytes

Neuropeptide Y (NPY) plays different roles in mammals such as: regulate food intake, memory retention, cardiovascular functions, and anxiety. It has also been shown in the modulation of chemotaxis, T lymphocyte differentiation, and leukocyte migration. In fish, NPY expression and functions have been studied but its immunomodulatory role remains undescribed. This study confirmed the expression and synthesis of NPY in S. salar under inflammation, and validated a commercial antibody for NPY detection in teleost. Additionally, immunomodulatory effects of NPY were assayed in vitro and in vivo. Phagocytosis and superoxide anion production in leukocytes and SHK cells were induced under stimulation with a synthetic peptide. IL-8 mRNA was selectively and strongly induced in the spleen, head kidney, and isolated cells, after in vivo challenge with NPY. All together suggest that NPY is expressed in immune tissues and modulates the immune response in teleost fish.     

Broadsheet. Number 50: Diagnosis of human cytomegalovirus infection and disease.

Human cytomegalovirus (CMV) remains an important cause of illness in immunocompromised individuals and the most common viral cause of congenital malformation. The tests available for diagnosis of CMV include serology, antigen detection, virus culture, tissue histopathology and nucleic acid detection. The diagnosis of CMV remains difficult because of the issues of virus latency, virus infection versus clinical disease and virus reactivation. The tests available and the use of these tests are undergoing significant changes. This Broadsheet presents a review of these tests, particularly in the diagnosis of congenital infection and infection in pregnant women and immunocompromised individuals.     

Viral regulators of complement activation: Structure,function and evolution

The complement system surveillance in the host is effective in controlling viral propagation. Consequently, to subvert this effector mechanism, viruses have developed a series of adaptations. One among these is encoding mimics of host regulators of complement activation (RCA) which help viruses to avoid being labeled as ‘foreign’ and protect them from complement-mediated neutralization and complement-enhanced antiviral adaptive immunity. In this review, we provide an overview on the structure, function and evolution of viral RCA proteins.     

Laboratory testing of anticoagulants: the present and the future

This review provides an update on laboratory testing and monitoring for existing and emerging anticoagulants, starting with an overview of haemostasis and the routine coagulation tests currently employed within most haemostasis laboratories, including the prothrombin time (PT)/international normalised ratio (INR) and the activated partial thromboplastin time (APTT). Current anticoagulant therapy and laboratory monitoring is then discussed in terms of benefits and limitations, followed by a similar brief discussion of the new and emerging anticoagulants. The main focus, however, is laboratory testing related to vitamin K antagonists, heparin, lepirudin and the new agents dabigatran etexilate and rivaroxaban. Although the newer agents do not require laboratory monitoring, laboratory testing will occasionally be required, and pathology laboratories should become proactive in developing appropriate strategies. The tests most likely to fulfill this role are the ecarin clotting time (or chromogenic alternatives), and the chromogenic anti-Xa assay. Nevertheless, the dilute Russell viper venom time (dRVVT) assay may provide another alternative, and existing routine tests are also likely to be utilised for the foreseeable future, potentially also for laboratory testing of the new anticoagulants, albeit perhaps in modified form.     

Cytotoxicity evaluation and antioxidant enzyme expression related to heavy metals found in tuna by-products meal: An in vitro study in human and rat liver cell lines

Heavy metals can accumulate in organisms via various pathways, including respiration, adsorption and ingestion. They are known to generate free radicals and induce oxidative and/or nitrosative stress with depletion of anti-oxidants. Tuna by-product meal (TBM) is rich in proteins and can, therefore, offer an attractive protein source for animals. This study was undertaken to assess the effects of metals present in TBM, namely cadmium (Cd), lead (Pb), and mercury (Hg), separately or in combination with oxidative stress, on cell viability. Three cell models: rat liver FTO2B, human hepatoma HepG2, and human hepatic WRL-68, were used. Cell viability was determined following exposure to various concentrations of the metals. Two antioxidant genes, catalase (CAT) and superoxide dismutase (SOD), were measured to obtain a better understanding of oxidative stress-associated gene expression. Among the metals present in TBM, only Cd at a concentration of 30 μM was noted to exhibit cytotoxic effects. This cytotoxicity was even more pronounced after co-stimulation with H₂O₂, used to mimic systemic oxidative stress. At non-toxic concentrations, Hg and Pb were noted to aggravate oxidative stress toxicity. The results further revealed that exposure to Cd, Pb, and a co-stimulation of H₂O₂ with Hg resulted in the increased expression of antioxidant gene SOD. A risk assessment of toxic contaminants in TBM indicated that food safety objectives should consider the human health impacts of foods derived from animals fed on contaminated meal and that much care should be taken when TBM is used in animal diet.     

Protein expression levels of carcinoembryonic antigen (CEA) in Danish ovarian cancer patients: from the Danish 'MALOVA'ovarian cancer study

AIMS: To determine the variation in expression of carcinoembryonic antigen (CEA) in 760 epithelial ovarian tumours from Denmark, and to correlate expression with clinicopathological parameters and prognosis for the disease. METHODS: Using tissue arrays (TA), we analysed CEA expression in tissues from 189 women diagnosed with low malignant potential ovarian tumours (LMP, borderline ovarian tumours) and 571 women diagnosed with ovarian cancer (OC). RESULTS: Using 30% as the cut-off level for CEA over-expression, 18% of LMPs and 4% of OCs were positive. A higher proportion of mucinous tumours were positive compared with other histological subtypes (p<0.00001). A univariate survival analysis suggested a shorter disease specific survival for patients with 30% or higher CEA expression in the tumour tissue (p = 0.004). In a Cox survival analysis, which included 569 OC cases subgrouped by stage (I to IV), the highest CEA expression compared with no expression was found to be a prognostic factor (level 3 versus negative: HR = 2.12, 95%CI 1.11-4.05). FIGO stage, residual tumour after primary surgery, age at diagnosis, other histological types versus serous adenocarcinoma and low versus high histological grade tumours were also prognostic factors. CONCLUSION: These data suggest that CEA expression is an independent prognostic factor for mucinous OC in Danish patients.