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Hindbrain catecholaminergic (CA) neurons are required for critical autonomic, endocrine, and behavioral counterregulatory responses (CRRs) to hypoglycemia. Recent studies suggest that CRR initiation depends on hindbrain astrocyte glucose sensors (McDougal DH, Hermann GE, Rogers RC. Front Neurosci 7: 249, 2013; Rogers RC, Ritter S, Hermann GE. Am J Physiol Regul Integr Comp Physiol 310: R1102–R1108, 2016). To test the proposition that hindbrain CA responses to glucoprivation are astrocyte dependent, we utilized transgenic mice in which the calcium reporter construct (GCaMP5) was expressed selectively in tyrosine hydroxylase neurons (TH-GCaMP5). We conducted live cell calcium-imaging studies on tissue slices containing the nucleus of the solitary tract (NST) or the ventrolateral medulla, critical CRR initiation sites. Results show that TH-GCaMP5 neurons are robustly activated by a glucoprivic challenge and that this response is dependent on functional astrocytes. Pretreatment of hindbrain slices with fluorocitrate (an astrocytic metabolic suppressor) abolished TH-GCaMP5 neuronal responses to glucoprivation, but not to glutamate. Pharmacologic results suggest that the astrocytic connection with hindbrain CA neurons is purinergic via P2 receptors. Parallel imaging studies on hindbrain slices of NST from wild-type C57BL/6J mice, in which astrocytes and neurons were prelabeled with a calcium reporter dye and an astrocytic vital dye, show that both cell types are activated by glucoprivation but astrocytes responded significantly sooner than neurons. Pretreatment of these hindbrain slices with P2 antagonists abolished neuronal responses to glucoprivation without interruption of astrocyte responses; pretreatment with fluorocitrate eliminated both astrocytic and neuronal responses. These results support earlier work suggesting that the primary detection of glucoprivic signals by the hindbrain is mediated by astrocytes.

Die bronchoalveolare Lavage [BAL] ist ein wichtiger diagnostischer Standard in der Diagnosestellung zahlreicher Lungenerkrankungen. Einen besonderen Stellenwert hat sie insbesondere bei den entzundlichen und interstitiellen Lungenparenchymerkrankungen. Fragestellung Im Rahmen der Diagnosestellung des Lungenkarzinoms ist der Zusatznutzen einer Bronchiallavage unklar. Daten zu einem moglicherweise typischen Verteilungsmuster in der Differenzialzytologie und in den Lymphozytenpopulationen in der BAL bei Lungenkrebspatienten fehlen. Insbesondere vor dem Hintergrund der mittlerweile beim nicht kleinzelligen Lungenkarzinom fest etablierten immunonkologischen Therapien, konnte es jedoch fur das Nebenwirkungsmanagement dieser Therapie von Bedeutung sein, ob Lungenkarzinome aufgrund einer Immunaktivierung ein typisches Verteilungsmuster in der BAL-Differenzialzytologie verursachen. Methodik Im Rahmen einer Hypothesen-generierenden retrospektiven Analyse untersuchten wir das Verteilungsmuster in der Differenzialzytologie der BAL von Lungenkrebspatienten im Rahmen der Erstdiagnose. Dabei wurden die BAL-Befunde von 38 Patienten im Rahmen der Erstdiagnose eines Lungenkarzinoms erfasst und ausgewertet. Ergebnis Es konnte eine Tendenz zu erhohten CD25-Lymphozytenanteilen und eine Erhohung DR-positiver Lymphozyten festgestellt werden. Beide gelten als Marker der Lymphozytenaktivierung. Ein typisches Verteilungsmuster konnte weder in der Differenzialzytologie noch in der Verteilung der Lymphozytensubpopulationen festgestellt werden. Moglicherweise konnten Untersuchungen zu microRNA-Mustern in Zukunft spezifische Veranderungen bei Lungenkrebspatienten zeigen, die dann die Diagnostik in Erstdiagnose und Nachsorge unterstutzen.

Proinflammatory cytokines impact islet β-cell mass and function by altering the transcriptional activity within pancreatic β-cells, producing increases in intracellular nitric oxide abundance and the synthesis and secretion of immunomodulatory proteins such as chemokines. Herein, we report that IL-1β, a major mediator of inflammatory responses associated with diabetes development, coordinately and reciprocally regulates chemokine and insulin secretion. We discovered that NF-κB controls the increase in chemokine transcription and secretion as well as the decrease in both insulin secretion and proliferation in response to IL-1β. Nitric oxide production, which is markedly elevated in pancreatic β-cells exposed to IL-1β, is a negative regulator of both glucose-stimulated insulin secretion and glucose-induced increases in intracellular calcium levels. By contrast, the IL-1β-mediated production of the chemokines CCL2 and CCL20 was not influenced by either nitric oxide levels or glucose concentration. Instead, the synthesis and secretion of CCL2 and CCL20 in response to IL-1β were dependent on NF-κB transcriptional activity. We conclude that IL-1β-induced transcriptional reprogramming via NF-κB reciprocally regulates chemokine and insulin secretion while also negatively regulating β-cell proliferation. These findings are consistent with NF-κB as a major regulatory node controlling inflammation-associated alterations in islet β-cell function and mass.

Severe autonomic dysfunction, including the loss of control of the cardiovascular, respiratory, and gastrointestinal systems, is a common comorbidity of stroke and other bleeding head injuries. Previous studies suggest that this collapse of autonomic control may be caused by thrombin acting on astrocytic protease-activated receptors (PAR1) in the hindbrain. Using calcium imaging and electrophysiological techniques, we evaluated the mechanisms by which astrocytic PAR1s modulate the activity of presynaptic vagal afferent terminals and postsynaptic neurons in the rat nucleus of the solitary tract (NST). Our calcium-imaging data show that astrocytic and neuronal calcium levels increase after brain slices are treated with the PAR1 agonist SFLLRN-NH2. This increase in activity is blocked by pretreating the slices with the glial metabolic blocker fluorocitrate. In addition, PAR1-activated astrocytes communicate directly with NST neurons by releasing glutamate. Calcium responses to SFLLRN-NH2in the astrocytes and neurons significantly increase after bath application of the excitatory amino acid transporter blockerdl-threo-β-benzyloxyaspartic acid (TBOA) and significantly decrease after bath application of the NMDA receptor antagonistdl-2-amino-5-phosphonopentanoic acid (dl-AP5). Furthermore, astrocytic glutamate activates neuronal GluN2B-containing NMDA receptors. Voltage-clamp recordings of miniature EPSCs (mEPSCs) from NST neurons show that astrocytes control presynaptic vagal afferent excitability directly under resting and activated conditions. Fluorocitrate significantly decreases mEPSC frequency and SFLLRN-NH2significantly increases mEPSC frequency. These data show that astrocytes act within a tripartite synapse in the NST, controlling the excitability of both postsynaptic NST neurons and presynaptic vagal afferent terminals.

Artemisia extracts have been used as remedies for a variety of maladies related to metabolic and gastrointestinal control. Because the vagal afferent-nucleus of the solitary tract (NST) synapse regulates the same homeostatic functions affected by Artemisia, it is possible that these extracts may have activity at the synaptic level in the NST. Therefore, we evaluated how extracts of three common medicinal Artemisia species, Artemisia santolinifolia (SANT), Artemisia scoparia (SCO), and Artemisia dracunculus L (PMI-5011), modulate the excitability of the glutamatergic vagal afferent-NST synapse. Our in vitro live cell calcium imaging data from prelabeled vagal afferent terminals show that SANT extract is a positive modulator of vagal afferent calcium levels, as the extract significantly increased the calcium signal relative to the time control. Neither SCO nor PMI-5011 extract altered the vagal calcium signals compared to the time control. Furthermore, whole cell voltage-clamp recordings from NST neurons corroborated the vagal terminal calcium data in that SANT extract also significantly increased miniature excitatory postsynaptic current (mEPSC) frequency in NST neurons. These data suggest that SANT extract could be a pharmacologically significant mediator of glutamatergic neurotransmission within the CNS.

Fasting and hypoglycemia elicit powerful gastrointestinal contractions. Whereas the relationship between utilizable nutrient and gastric motility is well recognized, the explanation of this phenomenon has remained incomplete. A relatively recent controversial report suggested that astrocytes in the dorsal hindbrain may be the principal detectors of glucoprivic stimuli. Our own studies also show that a subset of astrocytes in the solitary nucleus (NST) is activated by low glucose. It is very likely that information about glucopenia may directly impact gastric control because the hindbrain is also the location of the vago-vagal reflex circuitry regulating gastric motility. Our in vivo single unit neurophysiological recordings in intact rats show fourth ventricular application of 2-deoxyglucose (2-DG) inhibits NST neurons and activates dorsal motor nucleus (DMN) neurons involved in the gastric accommodation reflex. Additionally, as shown in earlier studies, either systemic insulin or central 2-DG causes an increase in gastric motility. These effects on motility were blocked by fourth ventricle pretreatment with the astrocyte inactivator fluorocitrate. Fluorocitrate administered alone has no effect on gastric-NST or -DMN neuron responsiveness, or on gastric motility. These results suggest that glucoprivation-induced increases in gastric motility are dependent on intact hindbrain astrocytes.

Objective St. John’s Wort (SJW) extract, which is commonly used to treat depression, inhibits the reuptake of several neurotransmitters, including glutamate, serotonin, norepinephrine, and dopamine. Glutamatergic visceral vagal afferents synapse upon neurons of the solitary tract (NST); thus, the aim of this study was to evaluate whether SJW extract modulates glutamatergic neurotransmission within the NST. Methods We used live cell calcium imaging to evaluate whether SJW and its isolated components hypericin and hyperforin increase the excitability of prelabeled vagal afferent terminals synapsing upon the NST. We used voltage-clamp recordings of spontaneous miniature excitatory postsynaptic currents (mEPSCs) to evaluate whether SJW alters glutamate release from vagal afferents onto NST neurons. Results Our imaging data show that SJW (50 μg/mL) increased the intracellular calcium levels of stimulated vagal afferent terminals compared with the bath control. This increase in presynaptic vagal afferent calcium by the extract coincides with an increase in neurotransmitter release within the nucleus of the solitary tract, as the frequency of mEPSCs is significantly higher in the presence of the extract compared with the control. Finally, our imaging data show that hyperforin, a known component of SJW extract, also significantly increases terminal calcium levels. Conclusion These data suggest that SJW extract can significantly increase the probability of glutamate release from vagal afferents onto the NST by increasing presynaptic calcium. The in vitro vagal afferent synapse with NST neurons is an ideal model system to examine the mechanism of action of botanical agents on glutamatergic neurotransmission.

Glucoprivation is a strong signal for the initiation of gastrointestinal contractions. While this relationship between utilizable nutrient levels and gastric motility has been recognized for more than 100 years, the explanation of this phenomenon has remained incomplete. Using widely differing approaches, recent work has suggested that the hindbrain is responsible for this chemoreflex effect. Surprisingly, astrocytes may be the main glucodetector elements under hypoglycemic conditions. Our own work using in vitro live cell calcium imaging shows that astrocytes in the NST increase cytoplasmic calcium in a concentration dependent manner in reaction to reductions in glucose. This effect is reversed on restoration of normal glucose concentrations. In vivo single unit neurophysiological recordings show that brainstem neurons driving gastric motility are activated by glucoprivic stimuli. Studies in intact animals verify that both dorsal medullary and systemic glucoprivation significantly increases gastric motility. Astrocyte inactivation with fluorocitrate blocks the pro-motility effects of glucoprivation. Thus, it appears that intact astrocyte signaling may be essential to glucoregulatory control over gastric motility.

Objective To describe the prevalence of incidental prostate cancer in patients undergoing radical cystoprostatectomy for bladder malignancy; to quantify the association between incidental prostate cancer and mortality in these patients; and to quantify the association between incidental prostate cancer and age in radical cystoprostatectomy specimens. Methods Consecutive patients undergoing radical cystoprostatectomy for bladder malignancy at six academic institutions were assessed. End-points were the histological diagnosis of prostate cancer in the radical cystoprostatectomy specimens and mortality. The association between incidental prostate cancer and mortality was calculated by multivariable Cox regression, and the association between age and the occurrence of prostate cancer was calculated by logistic regression. Results A total of 1122 patients (aged 65.6 ± 10 years) were included in this analysis. Prostate cancer was detected in 17.8% (n = 200) of the cystoprostatectomy specimens. After multivariable adjustment, prostate cancer was significantly associated with mortality (hazard ratio 1.27, 95% confidence interval 1.03–1.56). There was a significant association between age and the presence of prostate cancer in the cystoprostatectomy specimen. The odds ratio for the presence of prostate cancer was 1.028 (95% confidence interval 1.011–1.045; P

Previous studies from our laboratory illustrated the potential for stromal cell-derived factor one [CXCL12; also referred to as SDF-1] to act on its receptor [CXCR4] within the dorsal vagal complex [DVC] of the hindbrain to suppress gastric motility (Hermann et al., 2008). While CXCR4 receptors are essential for normal brain development, they also play a critical role in the proliferation of the HIV virus and initiation of metastatic cell growth in the brain. Anorexia, nausea, and failed autonomic regulation of gastrointestinal function are significant causes of morbidity and are contributory factors in the mortality associated with these disease states. The implication of our previous study was that CXCL12 caused gastric stasis by acting on gastric reflex circuit elements in the DVC. This hindbrain complex includes vagal afferent terminations in the solitary nucleus, neurons in the solitary nucleus (NST) and visceral efferent motorneurons in the dorsal motor nucleus (DMN) that are responsible for the regulation of digestive functions from the oral cavity to the transverse colon. In the current study, in vivo single-unit neurophysiological recordings from physiologically-identified NST and DMN components of the gastric accommodation reflex show that while injection of femtomole doses of CXCL12 onto NST or DMN neurons has no effect on their basal activity, CXCL12 amplifies the effect of gastric vagal mechanosensory input to activate the NST and, in turn, inhibit DMN motor activity.

The early proinflammatory cytokine tumor necrosis factor (TNF) is released in significant quantities by the activated immune system in response to infection, leukemia, autoimmune disorders, and radiation sickness. Nausea, emesis, and anorexia are common features of these disorders. TNF action on vagal afferent terminals in the brainstem is a likely cause of the malaise associated with these disorders. Our previous work has shown that TNF action to excite vagal afferents occurs as a result of sensitization of ryanodine channels in afferent nerve terminals. For millennia, cannabinoids (CB) have been used to combat the visceral malaise associated with chronic disease, although the mechanism of action has not been clear. Previous work in culture systems suggests that CB1 agonists can suppress neurotransmission by downregulating ryanodine channels through a protein kinase A (PKA)-dependent mechanism. Laser confocal calcium imaging methods were used to directly examine effects of CB1 cannabinoid agonists and TNF on visceral afferent signaling in the rat hindbrain. CB1 agonists blocked the effects of TNF to amplify vagal afferent responsiveness; blockade of PKA with H89 also eliminated the TNF amplification effect. These results help to explain the effectiveness of cannabinoids in blocking the malaise generated by TNF-releasing disease processes by opposing effects on ryanodine channels.

Cholecystokinin (CCK) is a potent regulator of visceral functions as a consequence of its actions on vago-vagal reflex circuit elements. This paper addresses three current controversies regarding the role of CCK to control gastric function via vago-vagal reflexes. Specifically: (a) whether CNS vs. peripheral (vagal afferent) receptors are dominant, (b) whether the long (58) vs. short (8) isoform is more potent and (c) whether nutritional status impacts the gain or even the direction of vago-vagal reflexes. Our in vivo recordings of physiologically identified gastric vagal motor neurones (gastric-DMN) involved in the gastric accommodation reflex (GAR) show unequivocally that: (a) receptors in the coeliac-portal circulation are more sensitive in amplifying gastric vagal reflexes; (b) in the periphery, CCK8 is more potent than CCK58; and (c) the nutritional status has a marginal effect on gastric reflex control. While the GAR reflex is more sensitive in the fasted rat, CCK amplifies this sensitivity. Thus, our results are in stark contrast to recent reports which have suggested that vago-vagal reflexes are inverted by the metabolic status of the animal and that this inversion could be mediated by CCK within the CNS.

The nucleus of the solitary tract (NST), located in the dorsomedial medulla, is the site of visceral sensory modulation of a variety of homeostatic reflexes. Given recent advancements in the understanding of active regulation of synaptic information flow by astrocytes, we sought to determine whether afferent sensory inputs to NST neurons also activates NST astrocytes. Using confocal, live-cell calcium imaging of brainstem slices, we investigated the possibility that stimulation of vagal sensory afferents, the major sensory input into the NST, activated NST astrocytes, as indicated by increases in astrocytic intracellular calcium concentrations ([Ca2+]i). Astrocytes and neurons were preloaded with the calcium reporter dye Calcium Green, and astrocytes were selectively stained by sulforhodamine 101. Electrical stimulation of vagal afferent axons produced rapid increases in [Ca2+]iin NST astrocytes as well as neurons. Surprisingly, this effect on astrocytes was blocked by the AMPA receptor antagonist NBQX and was unaffected by antagonism of NMDA and metabotropic glutamate receptors. Bath application of AMPA also activated astrocytes. This activation was dependent on extracellular Ca2+influx through both typical AMPA receptors and calcium-permeable AMPA receptors. This AMPA-mediated Ca2+influx was further amplified by actions of the ryanodine receptor by way of calcium-induced calcium release. Our immunohistochemical staining of NST cells further verified the presence of the AMPAR subunit GluR1 on astrocytes. These observations suggest that NST astrocytes may be active participants in the regulation of autonomic reflexes even in the normal, healthy state.

Leptin exerts a powerful permissive influence on neurogenic thermogenesis. During starvation and an absence of leptin, animals cannot produce thermogenic reactions to cold stress. However, thermogenesis is rescued by restoring leptin. We have previously observed a highly cooperative interaction between leptin and thyrotropin releasing hormone [TRH] to activate hindbrain generated thermogenic responses (Hermann et al., 2006). In vivo physiological studies (Rogers et al., 2009) suggested that the thermogenic impact of TRH in the hindbrain is amplified by the action of leptin through a leptin receptor-mediated production of phosphoinositiol tris phosphate [PIP3]. In turn, PIP3 can activate a tyrosine kinase whose target is the Src-SH2 regulatory site on the phospholipase C [PLC] complex. The TRH receptor signals through the PLC complex. Our immunohistochemical studies (Barnes et al., 2010) suggest that this transduction interaction between leptin and TRH occurs within neurons of the solitary nucleus [NST], though this interaction had not been verified. The present in vitro live cell calcium imaging study shows that while medial NST neurons are rarely activated by leptin alone, leptin pretreatment significantly augments NST neurons’ responsiveness to TRH. This leptin-mediated priming of NST neurons was uncoupled by pretreatment with the phosphoinositol-tris phosphate kinase [PI3K] inhibitor [wortmannin], the phospholipase C inhibitor [U73122] and the Src-SH2 antagonist [PP2]. TTX did not eliminate the synergistic response of the agonists, thus the sensitization cannot be attributed to pre-synaptic mechanisms. It seems likely that NST neurons are involved in the leptin mediated increase in BAT temperature by sensitizing the TRH-PLC-IP3-calcium release mechanism.

We have reported a highly cooperative interaction between leptin and thyrotropin releasing hormone (TRH) in the hindbrain to generate thermogenic responses (Hermann et al., 2006) (Rogers et al., 2009). Identifying the locus in the hindbrain where leptin and TRH act synergistically to increase thermogenesis will be necessary before we can determine the mechanism(s) by which this interaction occurs. Here, we performed heat-induced epitope recovery techniques and in situ hybridization to determine if neurons or afferent fibers in the hindbrain possess both TRH type 1 receptor and long-form leptin receptor [TRHR1; LepRb, respectively]. LepRb receptors were highly expressed in the solitary nucleus [NST], dorsal motor nucleus of the vagus [DMN] and catecholaminergic neurons of the ventrolateral medulla [VLM]. All neurons that contained LepRb also contained TRHR1. Fibers in the NST and the raphe pallidus [RP] and obscurrus [RO] that possess LepRb receptors were phenotypically identified as glutamatergic type 2 fibers (vglut2). Fibers in the NST and RP that possess TRHR1 receptors were phenotypically identified as serotonergic [i.e., immunopositive for the serotonin transporter; SERT]. Co-localization of LepRb and TRHR1 was not observed on individual fibers in the hindbrain but these two fiber types co-mingle in these nuclei. These anatomical arrangements may provide a basis for the synergy between leptin and TRH to increase thermogenesis.

Bleeding head injury is associated with gastric stasis, a symptom of collapse of autonomic control of the gut described by Cushing around 1932. Recent work suggests that the proteinase thrombin, produced secondary to bleeding, may be the root cause. Results from ourin vivophysiological studies show that fourth ventricular injection of PAR1 agonists, as well as thrombin itself, produced significant reductions in gastric transit in the awake rat. We expected that the PAR1 effect to inhibit gastric transit was the result of direct action on vagovagal reflex circuitry in the dorsal medulla. Surprisingly, our immunohistochemical studies demonstrated that PAR1 receptors are localized exclusively to the astrocytes and not the neurons in the nucleus of the solitary tract (NST; principal locus integrating visceral afferent input and part of the gastric vagovagal reflex control circuitry). Ourin vitrocalcium imaging studies of hindbrain slices revealed that PAR1 activation initially causes a dramatic increase in astrocytic calcium, followed seconds later by an increase in calcium signal in NST neurons. The neuronal effect, but not the astrocytic effect, of PAR1 activation was eliminated by glutamate receptor antagonism. TTX did not eliminate the effects of PAR1 activation on either glia or neurons. Thus, we propose that glia are the primary CNS sensors for PAR agonists and that the response of these glial cells drives the activity of adjacent (e.g., NST) neurons. These results show, for the first time, that changes in autonomic control can be directly signaled by glial detection of local chemical stimuli.

Tumor necrosis factor [TNF] produces a profound anorexia associated with gastrointestinal stasis. Our work suggests that the principal site of action of TNF to cause this change in gastric function is via vagal afferents within the nucleus of the solitary tract [NST]. Excitation of these afferents presumably causes gastric stasis by activating downstream NST neurons that, in turn, suppress gastric motility via action on neurons in the dorsal motor nucleus of the vagus that project to the stomach. Results from our parallel studies on gastric vago-vagal reflexes suggest that noradrenergic neurons in the NST are particularly important to the generation of reflex gastroinhibition. Convergence of these observations led us to hypothesize that TNF action in the NST may preferentially affect putative noradrenergic neurons. The current study confirms our observations of a dose-dependent TNF activation of cells [as indicated by cFOS production] in the NST. The phenotypic identity of these TNF-activated neurons in the NST was approximately 29% tyrosine hydroxylase [TH]-positive [i.e., presumably noradrenergic neurons]. In contrast, less than 10% of the nitrergic neurons were activated after TNF exposure. Surprisingly, another 54% of the cFOS-activated cells in the NST were phenotypically identified to be astrocytes. Taken together with previous observations, the present results suggest that intense or prolonged vagal afferent activity [induced by visceral pathway activity, action of gut hormones or cytokines such as TNF] can alter local astrocyte immediate early gene expression that, in turn, can provoke long-term, perhaps permanent changes in the sensitivity of vagal-reflex circuitry.

Glutamatergic synaptic currents elicited in second-order neurons in the nucleus of the solitary tract (nTS) by activation of chemosensory and other visceral afferent fibers are severely reduced following 10 days of chronic intermittent hypoxia (CIH). The mechanism by which this occurs is unknown. A strong candidate for producing the inhibition is dopamine, which is also released from the presynaptic terminals and which we have shown exerts a tonic presynaptic inhibition on glutamate release. We postulated that tonic activation of the D2 receptors inhibits presynaptic calcium currents to reduce transmitter release and that in CIH this occurs in conjunction with an increase in the dopamine inhibitory response due to the increase in presynaptic D2 receptors or an increase in dopamine release further suppressing the evoked excitatory postsynaptic current (eEPSC). Thus we predicted that blockade of the D2 receptors would return the EPSC to values of animals maintained under normoxic conditions. We found that dopamine and quinpirole, the selective D2-like agonist, inhibit calcium currents via the D2 receptors by acting on the N-type calcium channel in presynaptic neurons and their nTS central terminals. However, in brain slice studies from CIH animals, although the D2 antagonist sulpiride increased the CIH-reduced amplitude of synaptic currents, EPSCs were not restored to normal levels. This indicates that while the dopamine inhibitory effect remains intact in CIH, most of the reduction in the eEPSC amplitude occurs via alternative mechanisms.

The intermediate reticular formation (IRt) subjacent to the rostral (gustatory) nucleus of the solitary tract (rNST) receives projections from the rNST and appears essential to the expression of taste-elicited ingestion and rejection responses. We used whole cell patch-clamp recording and calcium imaging to characterize responses from an identified population of prehypoglossal neurons in the IRt to electrical stimulation of the rNST in a neonatal rat pup slice preparation. The calcium imaging studies indicated that IRt neurons could be activated by rNST stimulation and that many neurons were under tonic inhibition. Whole cell patch-clamp recording revealed mono- and polysynaptic projections from the rNST to identified prehypoglossal neurons. The projection was primarily excitatory and glutamatergic; however, there were some inhibitory GABAergic projections, and many neurons received excitatory and inhibitory inputs. There was also evidence of disinhibition. Overall, bath application of GABAA antagonists increased the amplitude of excitatory currents, and, in several neurons, stimulation of the rNST systematically decreased inhibitory currents. We have hypothesized that the transition from licks to gapes by natural stimuli, such as quinine monohydrochloride, could occur via such disinhibition. We present an updated dynamic model that summarizes the complex synaptic interface between the rNST and the IRt and demonstrates how inhibition could contribute to the transition from ingestion to rejection.

Indexed and Fibred category theory have a long tradition in computer science as a language to formalize different presentations of the notion of a logic, as for instance, in the theory of institutions and general logics, and as unifying models of (categorical) logic and type theory as well. Here we introduce the notions of indexed and fibred frames and construct a rich mathematical workspace where many relevant and useful concepts of logics can be elegantly modelled. To demonstrate the applicability of these tools, essential ideas around the theory of institutions are recasted and described.

Explanations of leptin induction of thermogenesis typically involve primary detection elements in the hypothalamus. In turn, these circuits control medullary raphe neurons that regulate spinal efferent sympathetic projections to heat-producing brown adipose tissue (BAT). The hindbrain may be capable of considerable thermoregulatory capacity independent of the hypothalamus, though little is known about the site(s), mechanism(s) of action, or the physiological consequences of leptin action in the hindbrain. Several reports describe the presence of leptin receptor in the solitary nucleus, and there is functional evidence that leptin can act in the dorsal medulla to suppress feeding. We examined the effects of leptin, applied to the dorsal medulla, on BAT thermogenesis. Leptin alone (or =25 microg) had no independent effect on BAT thermogenesis. We hypothesized that, while leptin may not be capable of activating thermocontrol mechanisms in the hindbrain directly, it may modulate the efficacy of other neural signals involved in the control of thermogenesis such as thyrotropin-releasing hormone (TRH). We tested the hypothesis that leptin and TRH, acting in the hindbrain, co-regulate thermogenesis. As expected, TRH (0.1 microg), alone, produces a small increase (+0.75 degrees C) in BAT temperature. Co-application of leptin (5 mug) and TRH (0.1 microg) to the dorsal medulla produces an increase in BAT and core temperature more than 300% greater than TRH alone (+3.5 degrees C). This effect is undiminished in the acute decerebrate rat, suggesting that the effect is mediated entirely by the hindbrain.

The cytokine tumor necrosis factor(alpha) (TNF(alpha)) is associated with a constellation of physiological and behavioral characteristics that follow in response to infection such as fever, fatigue, listlessness, loss of appetite, malaise, and tactile hypersensitivity. These responses are examples of central nervous system (CNS) functions modified by the activated immune system. Our studies have focused on the involvement of TNF(alpha) in CNS control of gastrointestinal function and "visceral malaise". We have demonstrated that TNF(alpha) can elicit gastric stasis in a dose-dependent fashion via its interaction with vago-vagal neurocircuitry in the brainstem. Sensory elements of the vago-vagal reflex circuit (i.e., neurons of the solitary tract [NST] and area postrema [AP]) are activated by exposure to TNF(alpha), while the efferent elements (i.e., dorsal motor neurons of the vagus [DMN]) cause gastroinhibition. Transient exposure to low doses of TNF(alpha) cause potentiated (exaggerated) NST responses to stimulation. Subsequent studies suggest that TNF(alpha) presynaptically modulates the release of glutamate from primary afferents to the NST. Using immunohistochemical studies, we have observed the constitutive expression of the TNFR1 receptor on central vagal afferents and spinal trigeminal afferents in the medulla, as well as on cells and afferent fibers within the dorsal root ganglia and within laminae I and II of the dorsal horn throughout the spinal cord. The constitutive presence of these receptors on these afferents may explain why inflammatory or infectious processes that generate TNF(alpha) can disrupt gastrointestinal functions and cause tactile hypersensitivity. These receptors may also play a critical role in the chronic allodynia and hyper-reflexia observed after spinal cord injury or peripheral nerve damage.

The nucleus of the solitary tract (NST) processes substantial visceral afferent input and sends divergent projections to a wide array of CNS targets. The NST is essential to the maintenance of behavioural and autonomic homeostasis and is the source, as well as the recipient, of considerable noradrenergic (NE) projections. The significance of NE projections from the NST to other CNS regions has long been appreciated, but the nature of NE action on NST neurones themselves, especially on the α-1 receptor subtype, is controversial. We used a combination of methodologies to establish, systematically, the effects and cellular basis of action of the α-1 agonist, phenylephrine (PHE), to control NST neurones responsible for vago-vagal reflex regulation of the stomach. Immunocytochemical and retrograde tracing studies verified that the area postrema, A2, A5, ventrolateral medulla and locus coeruleus regions are sources of catecholaminergic input to the NST. In vivo electrophysiological recordings showed that PHE activates physiologically identified, second-order gastric sensory NST neurones. In vivo microinjection of PHE onto NST neurones caused a significant reduction in gastric tone. Finally, in vitro calcium imaging studies revealed that PHE caused dramatic cytosolic calcium oscillations in NST neurones. These oscillations are probably the result of an interplay between agonist-induced and inositol 1,4,5-trisphosphate (IP3)-mediated intracellular calcium release and Ca2+-ATPase control of intracellular calcium storage pumps. The oscillations persisted even in perfusions of zero calcium–EGTA Krebs solution suggesting that the calcium oscillation is mediated principally by intracellular calcium release–reuptake mechanisms. Cyclical activation of the NST may function to increase the responsiveness of these neurones to incoming afferent input (i.e., elevate the ‘gain’). An increase in gain of afferent input may cause an amplification of the response part of the reflex and help explain the powerful effects that α-1 agonists have in suppressing gastric motility and producing anorexia.

The dorsal motor nucleus of the vagus (DMV) receives more noradrenergic terminals than any other medullary nucleus; few studies, however, have examined the effects of norepinephrine (NE) on DMV neurons. Using whole cell recordings in thin slices, we determined the effects of NE on identified gastric-projecting DMV neurons. Twenty-five percent of DMV neurons were unresponsive to NE, whereas the remaining 75% responded to NE with either an excitation (49%), an inhibition (26%), or an inhibition followed by an excitation (4%). Antrum/pylorus- and corpus-projecting neurons responded to NE with a similar percentage of excitatory (49 and 59%, respectively) and inhibitory (20% for both groups) responses. A lower percentage of excitatory (37%) and a higher percentage of inhibitory (36%) responses were, however, observed in fundus-projecting neurons. In all groups, pretreatment with prazosin or phenylephrine antagonized or mimicked the NE-induced excitation, respectively. Pretreatment with yohimbine or UK-14304 antagonized or mimicked the NE-induced inhibition, respectively. These data suggest that NE depolarization is mediated by α1-adrenoceptors, whereas NE hyperpolarization is mediated by α2-adrenoceptors. In 16 neurons depolarized by NE, amplitude of the action potential afterhyperpolarization (AHP) and its kinetics of decay (τ) were significantly reduced vs. control. No differences were found on the amplitude and τ of AHP in neurons hyperpolarized by NE. Using immunohistochemical techniques, we found that the distribution of tyrosine hydroxylase fibers within the DMV was significantly different within the mediolateral extent of DMV; however, distribution of cells responding to NE did not show a specific pattern of localization.

Our previous studies have shown that tumor necrosis factor-alpha (TNF-alpha) activates solitary nucleus neurons involved in vago-vagal reflex control of gastric motility. Here, we describe the dual role of TNF-alpha as also modulating neurons in the dorsal motor nucleus of the vagus (DMN) that respond to gastric distention. A large majority of physiologically identified DMN neurons are rapidly and completely inhibited by exposure to TNF-alpha, suggesting that TNF-alpha may induce gastric stasis by functioning as a hormone that modulates both portions of this reflex pathway during illness.

Our previous studies suggested that the cytokine tumor necrosis factor-alpha (TNF-alpha) may act within the neural circuitry of the medullary dorsal vagal complex (DVC) to affect changes in gastric function, such as gastric stasis, loss of appetite, nausea, and vomiting. The definitive demonstration that endogenously generated TNF-alpha is capable of affecting gastric function via the DVC circuitry has been impeded by the lack of an antagonist for TNF-alpha. The present studies used localized central nervous system applications of the TNF-adsorbant construct (TNFR:Fc; TNF-receptor linked to the Fc portion of the human immunoglobulin IgG1) to attempt to neutralize the suppressive effects of endogenously produced TNF-alpha. Gastric motility of thiobutabarbital-anesthetized rats was monitored after systemic administration of lipopolysaccharide (LPS) to induce TNF-alpha production. Continuous perfusion of the floor of the fourth ventricle with TNFR:Fc reversed the potent gastroinhibition induced by LPS, i.e., central thyrotropin-releasing hormone-induced increases in motility were not inhibited. This disinhibition of gastric stasis was not seen after intravenous administration of similar doses of TNFR:Fc nor ventricular application of the Fc fragment of human immunoglobulin. These results validate our previous studies that suggest that circulating TNF-alpha may act directly within the DVC to affect gastric function in a variety of pathophysiological states.

In vivo and in vitro electrophysiological experiments were performed on the rat dorsal vagal complex (DVC, i.e. nucleus of the tractus solitarius, NTS, and dorsal motor nucleus of the vagus, DMV) to examine the effects of corticotropin releasing hormone (CRF) on the central components of the vago-vagal reflex control of gastric function. When applied to gastrointestinal projecting DMV neurones, CRF (10-300 nm) induced a concentration-dependent membrane depolarization, an increase in action potential firing rate and decrease in amplitude of the action potential afterhyperpolarization (P < 0.05). Pretreatment with the non-selective CRF antagonist, astressin (0.5-1 μM) or the selective CRF2 receptor antagonist, astressin 2B (500 nm) attenuated the CRF-induced increase in firing rate but did not alter basal discharge rate. CRF (30-300 nm) increased the amplitude of excitatory postsynaptic currents (EPSCs) evoked by stimulation of the NTS (P < 0.05). An alteration in the paired pulse ratio indicated the EPSC's increase occurred due to actions at presynaptic sites. In the in vivo anaesthetized rat preparation, bilateral microinjections (20 fmol in 20 nl for each site) of CRF in the DVC decreased gastric motility in rats pretreated with the muscarinic agonist, bethanecol (P < 0.05). The effects of CRF were abolished by systemic administration of the NOS inhibitor, l-NAME, or by bilateral vagotomy. We concluded that CRF had both a direct and an indirect excitatory effect on DMV neurones via activation of CRF2 receptors and the decrease in gastric motility observed following microinjection of CRF in the DVC is due to the activation of an inhibitory non-adrenergic non-cholinergic input to the gastrointestinal tract.

Rat preparations were used to investigate long-term changes in external anal sphincter (EAS) contractions and reflexive penile erection following electrolytic lesions of the nucleus raphe obscurus (nRO) or the rostral ventrolateral medulla. EAS contractions were measured electromyographically (EAS EMG) following distention of the EAS with a 5-mm probe. Penile erections were measured using a standard ex copula reflex testing paradigm. At 48 h postlesion, 100% of nRO-lesioned animals displayed reflexive erections and the magnitude of EAS EMG was significantly greater in lesioned animals than in sham controls. These results suggested EAS hyperreflexia following destruction of the nRO. By 14 days postlesion, EAS responsiveness in nRO-lesioned animals had returned to levels comparable to nonlesioned animals. No measures of penile erection were affected by nRO lesions. In animals with nucleus gigantocellularis (Gi) and lateral nucleus paragigantocellularis (Gi-lPGi) lesions, no significant changes to EAS reflexes were observed at any time point. At 48 h postoperative, Gi-lPGi lesions significantly reduced the latency to first erection and increased the number of erections elicited relative to controls. Similar facilitation of erection latency was observed at 14 days postlesion, while erection number and flip total were no longer significantly different from controls. These and previous studies suggest that the nRO regulates defecatory reflexes in the rat. These data further suggest that the comingled EAS and bulbospongiosus (BS) motoneurons are controlled by discrete and separate brainstem circuits and that increases in EAS and penile reflexes after spinal cord lesions are mediated by loss of different descending inputs.

Pancreatic cystic neoplasms are uncommon, but it is important to differentiate them from pseudocysts and ductal adenocarcinoma. A retrospective review was performed to determine distinguishing characteristics and optimal treatment. In 51 patients operated on between 1981 and 1994 at a referral center, the following cystic neoplasms were found: 20 serous cystadenomas, 10 mucinous cystadenomas, 11 mucinous cystadenocarcinomas, five cases of mucinous ductal ectasia, and five papillary cystic neoplasms. Both mucinous ductal ectasia and papillary cystic neoplasms had distinguishing features when compared to other cystic neoplasms. Mucinous ductal ectasia was seen only in men, presented with typical symptoms, and had distinctive features on endoscopic retrograde cholangiopancreatography. Papillary cystic neoplasms occurred in young women (mean age 31 years) and were larger (mean 10.3 cm). Mucinous tumors were always symptomatic, whereas 55% of serous tumors were asymptomatic (P

The management of common bile duct stones traditionally required laparotomy for extraction. Recent advances have occurred in radiologic, endoscopic, and surgical techniques to broaden our options to treat patients with choledocholithiasis. The surgical approaches to the common duct stone have expanded to include open and laparoscopic techniques. Despite the increased surgical armamentarium, the principles of surgical management have not been altered. This chapter addresses the traditional surgical approaches to common bile duct stones.

In reactive arthritis (ReA), sterile synovitis is an immunological sequela following gastrointestinal or urogenital infection with facultatively intracellular bacteria (Yersinia, Salmonella, Shigella, Chlamydia). It is widely accepted now that the development of arthritis is closely related to the persistance of bacteria or bacterial antigens in extraarticular mucosal or lymphoid tissues (i.e. gut mucosa, gut associated lymphoid tissue, genitourinary mucosa); however, it is still unclear which host mechanisms are responsible for the poorer elimination of arthritis-causing microorganisms in those ReA patients. Bacterial components are also camed to the joints where they can be demonstrated in synovial fluid (SF) immune complexes (1) as well as intracellularly in SF phagocytes (2) and synovial membrane cells (3). Although the clinical arthrological picture is very similar in postveneric and postenteric ReA, there seem to be differences in terms of the intraarticular detection of viable bacteria. In postveneric Reiter’s disease, Chlamydial DNA has been detected in synovial membrane specimens using the polymerase chain reaction (PCR) (4). In contrast, Yersinia DNA has been sought in SF cells with negative results so far (5) suggesting that only parts of the Yersinia microorganisms enter the’joint to initiate humoral and cellular immune reactions in Yersinia induced ReA. Our group has focussed attention on the T cellular immune events at the site of synovitic inflammation. We favor the concept of deposition of bacterial components in the synovial compartment of ReA patients. Consecutively, specific recognition of bacterial antigens by synovial T lymphocytes initiates an antibacterial immune response. The immune-mediated inflammation may then be maintained by HLA-B27 restricted, by unspecific or autoreactive immune events even after the bacterial antigens have been cleared. If this hypothesis is correct it will be of interest to study

The cytokine tumor necrosis factor(alpha) (TNF(alpha)) is associated with a constellation of physiological and behavioral characteristics that follow in response to infection such as fever, fatigue, listlessness, loss of appetite, malaise, and tactile hypersensitivity. These responses are examples of central nervous system (CNS) functions modified by the activated immune system. Our studies have focused on the involvement of TNF(alpha) in CNS control of gastrointestinal function and "visceral malaise". We have demonstrated that TNF(alpha) can elicit gastric stasis in a dose-dependent fashion via its interaction with vago-vagal neurocircuitry in the brainstem. Sensory elements of the vago-vagal reflex circuit (i.e., neurons of the solitary tract [NST] and area postrema [AP]) are activated by exposure to TNF(alpha), while the efferent elements (i.e., dorsal motor neurons of the vagus [DMN]) cause gastroinhibition. Transient exposure to low doses of TNF(alpha) cause potentiated (exaggerated) NST responses to stimulation. Subsequent studies suggest that TNF(alpha) presynaptically modulates the release of glutamate from primary afferents to the NST. Using immunohistochemical studies, we have observed the constitutive expression of the TNFR1 receptor on central vagal afferents and spinal trigeminal afferents in the medulla, as well as on cells and afferent fibers within the dorsal root ganglia and within laminae I and II of the dorsal horn throughout the spinal cord. The constitutive presence of these receptors on these afferents may explain why inflammatory or infectious processes that generate TNF(alpha) can disrupt gastrointestinal functions and cause tactile hypersensitivity. These receptors may also play a critical role in the chronic allodynia and hyper-reflexia observed after spinal cord injury or peripheral nerve damage.

This article describes the conception and structure of the German Food Code and Nutrient Data Base (BLS). The data bank contains approx. 12,000 coded foods, menus and menu components in different stages of processing with up to 158 nutritional data for each product. Since comparatively few analytical data on the composition of foods are available, the majority of the data in the BLS are based on nutritional data calculated from recipes. Thus, a standard instrument for an uninterrupted (no missing values) evaluation of consumption surveys is made available.

Gastric stasis is frequently seen in conjunction with critical infectious illness, chronic inflammatory disorders, radiation sickness, and carcinogenesis. These conditions are associated with elevated circulating levels of the cytokine tumor necrosis factor-alpha (TNF-alpha). The present studies examined the relationship between endogenously produced TNF-alpha and the central neural mechanisms that augment gastric motility. Systemic lipopolysaccharide (LPS) was employed to induce TNF-alpha production in thiobutabarbital-anesthetized rats. Sixty minutes after intravenous LPS injection, gastric motility could not be stimulated by a potent centrally acting gastrokinetic stimulant, thyrotropin-releasing hormone (TRH). This failure to elicit gastric motility via central mechanisms coincided with high circulating levels of TNF-alpha. However, intravenous injections of bethanecol, a peripherally acting cholinergic agonist with direct gastrokinetic effects, were still able to elicit normal increases in gastric motility in the presence of TNF-alpha and LPS. Therefore, the inability to stimulate gastric motility via central TRH could not be attributed to the direct inhibitory effects of either LPS or TNF-alpha on the stomach. If the production of endogenous TNF-alpha was suppressed via the use of urethan as the anesthetic agent, then intravenous injections of LPS were no longer effective in suppressing gastric motility. Thus these effects on gastric motility are not directly attributable to LPS nor are they due to direct effects on the gastric smooth muscle. Our previous study demonstrated that microinjection of femtomole quantities of TNF-alpha in the brain stem dorsal vagal complex (DVC) can modulate gastric motility. This central TNF-alpha effect on gastric motility was dose dependent and required an intact vagal efferent pathway. The results from these two studies suggest that systemically produced TNF-alpha may gain access to the DVC to modulate gastric function.

stress, defined as the perception of threatening stimuli and the emotion and mental activity expended contemplating the threat, has been associated medically with the derangement of normal bowel function since ancient times ( Nature of Man , Hippocrates, circa 630 BC). More recently, Bockus ([2][1

This study assesses the long-term results of operations for benign gastric ulcers. Three-hundred forty-nine patients operated upon between 1950-1979 have been followed over the past 20 years with a mean and median follow-up of 11.8 and 11.1 years. Fifty-five per cent of the patients had a gastric resection without vagotomy; 19.8 per cent had gastric resection with vagotomy; and 20.3 per cent had vagotomy, pyloroplasty, and wedge excision or biopsy of the ulcer. Operations were selected based on the type of ulcer (Types 1-4), whether the surgeon suspected cancer preoperatively, whether the operations was elective or an emergency, and the age and general health of the patient (presence of significant co-morbid disease). Overall mortality was 6.9 per cent, with a mortality for elective operations 3.6 per cent, and for emergency operations of 32.5 per cent. Age and cardiovascular disease were significant factors in operative mortality and morbidity. All operations were equivalent in long-term results. Excellent to good results were obtained in 92 per cent of patients, with an ulcer recurrence rate of 4 per cent. We conclude that vagotomy, pyloroplasty, and wedge excision or biopsy of a benign gastric ulcer is a comparable operation to a more major gastric resection, with or without vagotomy, in the surgical management of gastric ulcer. The addition of vagotomy to gastric resection does not appear to improve long-term results.

The aim of this study is to assess in vitro the efficacy of a plasma fractionator to remove trypsin complexed alpha 2MG (alpha-2 macroglobulin) from human plasma in a manner analogous to the reticuloendothelial system (RES). Eval filter type "4A" (Kuraray Co., Osaka, Japan) was chosen as a plasma fractionator. Two and one half liters of bovine trypsin spiked human plasma was perfused in vitro through the fractionator in a single pass mode (n = 5). The concentrations of complexed alpha 2MG, total alpha 2MG, albumin, and IgM were measured before and after fractionation, and the concentration of free alpha 2MG and the sieving coefficients of each solute were calculated. The concentration of the trypsin complexed alpha 2MG measured by ELISA was significantly decreased by fractionation with Eval "4A" from 103.7 +/- 16.7 to 13.8 +/- 8.2 mg/L (reduction of 86.7%). Mean sieving coefficients of each solute were 0.133 +/- 0.079 in complexed alpha 2MG, 0.203 +/- 0.065 in free alpha 2MG, 0.203 +/- 0.065 in total alpha 2MG, 0.770 +/- 0.130 in albumin, and 0.070 +/- 0.010 in IgM. Although in vivo study will be required in patients with acute pancreatitis, in vitro study shows the feasibility of membrane plasma fractionation in eliminating trypsin complexed alpha 2MG.

Expanding RN utilization in the ambulatory care setting provides numerous cost and patient care benefits during a time when health care costs are rising. Ambulatory care management personnel and physicians should analyze their present staffing and patient mix to determine if using a diversified nursing practice could benefit their practice. Nurses have been an integral part of the health care team since the 1800s. As the 21st Century quickly approaches, the role of the RN will be critical as ambulatory medicine attempts to improve patient satisfaction and patient access while continuing to provide quality care in a cost-effective manner.

The results of adjuvant chemotherapy (CMF), endocrine therapy (t), and immunotherapy (BCG) in 318 women who had undergone mastectomy for Stage II breast cancer are reported after 45 months of life table analysis. CMFT therapy was found to be more effective than CMF alone in increasing recurrence-free survival. This beneficial effect appears to be limited to patients with estrogen receptor-positive tumors (ER+). Patients with estrogen receptor-negative tumors (ER-) (< 3 fmol/mg) have increased recurrence rates and higher mortality.