Hyperdipsia in sheep bearing lesions in the medial septal nucleus.

Previous experiments in rodents showed that ablation of the septal brain region caused hyperdipsia. We investigated which part of the septal region needs ablation to produce hyperdipsia in sheep, and whether increased drinking was a primary hyperdipsia. Following ablation of the medial septal region (n = 5), but not parts of the lateral septal region (n = 4), daily water intake increased from ~2.5-5 L/day up to 10 L/day for up to 3 months post-lesion. In hyperdipsic sheep, plasma osmolality increased on the first day post-lesion and body weight fell, suggesting that initial hyperdipsia was secondary to fluid loss. However hyperosmolality was not sustained long-term and plasma hypo-osmolality persisted from 0.5 to 3 months post-lesion. Acute dipsogenic responses to intravenous hypertonic saline, intravenous or intracerebroventricular angiotensin II, water deprivation for 2 days, or feeding over 5 h were not potentiated by medial septal lesions, showing that the rapid pre-systemic inhibitory influences that cause satiation of thirst upon the act of drinking were intact. However, hyperdipsic sheep continued to ingest water when hyponatremic (plasma [Na] was 127-132 mmol/l) and plasma osmolality was 262-268 mosmol/kg due to retention of ingested fluid resulting from intravenous infusion of vasopressin administered to maintain a basal blood level of antidiuretic hormone. The results show that septal lesion-induced hyperdipsia is not due to disruption of acute pre-systemic influences associated with drinking water that initiates rapid satiation of thirst. Rather, inhibitory influences of hyponatremia, hypo-osmolality or hypervolemia on drinking appear to be disrupted by medial septal lesions.

Characterization of Autophagic Responses in Drosophila melanogaster.

Drosophila is an excellent model system for studying autophagy during animal development due to the availability of genetic reagents and opportunity for in vivo cell biological analysis. The regulation and mechanism of autophagy are highly evolutionarily conserved and the role of autophagy has been characterized during various stages of Drosophila development as well as following starvation. Studies in Drosophila have revealed novel insights into the role of distinct components of the autophagy machinery. This chapter describes protocols for examining autophagy during Drosophila development. A crucial step in the induction of autophagy is the incorporation of Atg8a into the autophagosome. This can be measured as autophagic puncta using live fluorescent imaging, immunostaining, or immunoblot analysis of LC3/Atg8a processing. The level of autophagy can also be examined using other specific components of the autophagy pathway as markers detected by immunofluorescent imaging. Based on the distinct morphology of autophagy, it can also be examined by transmission electron microscopy. In addition, one of the advantages of using Drosophila as a model is the ability to undertake genetic analysis of individual components of the autophagy machinery. Current approaches that can be used to monitor autophagy, including the overall flux and individual steps in Drosophila melanogaster, will be discussed.

Large scale accelerator production of 225Ac: Effective cross sections for 78-192MeV protons incident on 232Th targets.

Actinium-225 and 213Bi have been used successfully in targeted alpha therapy (TAT) in preclinical and clinical research. This paper is a continuation of research activities aiming to expand the availability of 225Ac. The high-energy proton spallation reaction on natural thorium metal targets has been utilized to produce millicurie quantities of 225Ac. The results of sixteen irradiation experiments of thorium metal at beam energies between 78 and 192MeV are summarized in this work. Irradiations have been conducted at Brookhaven National Laboratory (BNL) and Los Alamos National Laboratory (LANL), while target dissolution and processing was carried out at Oak Ridge National Laboratory (ORNL). Excitation functions for actinium and thorium isotopes, as well as for some of the fission products, are presented. The cross sections for production of 225Ac range from 3.6 to 16.7mb in the incident proton energy range of 78-192MeV. Based on these data, production of curie quantities of 225Ac is possible by irradiating a 5.0gcm-2 232Th target for 10 days in either BNL or LANL proton irradiation facilities.

Distinct requirements of Autophagy-related genes in programmed cell death.

Although most programmed cell death (PCD) during animal development occurs by caspase-dependent apoptosis, autophagy-dependent cell death is also important in specific contexts. In previous studies, we established that PCD of the obsolete Drosophila larval midgut tissue is dependent on autophagy and can occur in the absence of the main components of the apoptotic pathway. As autophagy is primarily a survival mechanism in response to stress such as starvation, it is currently unclear if the regulation and mechanism of autophagy as a pro-death pathway is distinct to that as pro-survival. To establish the requirement of the components of the autophagy pathway during cell death, we examined the effect of systematically knocking down components of the autophagy machinery on autophagy induction and timing of midgut PCD. We found that there is a distinct requirement of the individual components of the autophagy pathway in a pro-death context. Furthermore, we show that TORC1 is upstream of autophagy induction in the midgut indicating that while the machinery may be distinct the activation may occur similarly in PCD and during starvation-induced autophagy signalling. Our data reveal that while autophagy initiation occurs similarly in different cellular contexts, there is a tissue/function-specific requirement for the components of the autophagic machinery.

Relationship between growth arrest and autophagy in midgut programmed cell death in Drosophila.

Autophagy has been implicated in both cell survival and programmed cell death (PCD), and this may explain the apparently complex role of this catabolic process in tumourigenesis. Our previous studies have shown that caspases have little influence on Drosophila larval midgut PCD, whereas inhibition of autophagy severely delays midgut removal. To assess upstream signals that regulate autophagy and larval midgut degradation, we have examined the requirement of growth signalling pathways. Inhibition of the class I phosphoinositide-3-kinase (PI3K) pathway prevents midgut growth, whereas ectopic PI3K and Ras signalling results in larger cells with decreased autophagy and delayed midgut degradation. Furthermore, premature induction of autophagy is sufficient to induce early midgut degradation. These data indicate that autophagy and the growth regulatory pathways have an important relationship during midgut PCD. Despite the roles of autophagy in both survival and death, our findings suggest that autophagy induction occurs in response to similar signals in both scenarios.

Cell death by autophagy: facts and apparent artefacts.

Autophagy (the process of self-digestion by a cell through the action of enzymes originating within the lysosome of the same cell) is a catabolic process that is generally used by the cell as a mechanism for quality control and survival under nutrient stress conditions. As autophagy is often induced under conditions of stress that could also lead to cell death, there has been a propagation of the idea that autophagy can act as a cell death mechanism. Although there is growing evidence of cell death by autophagy, this type of cell death, often called autophagic cell death, remains poorly defined and somewhat controversial. Merely the presence of autophagic markers in a cell undergoing death does not necessarily equate to autophagic cell death. Nevertheless, studies involving genetic manipulation of autophagy in physiological settings provide evidence for a direct role of autophagy in specific scenarios. This article endeavours to summarise these physiological studies where autophagy has a clear role in mediating the death process and discusses the potential significance of cell death by autophagy.

Cortical activation and lamina terminalis functional connectivity during thirst and drinking in humans.

The pattern of regional brain activation in humans during thirst associated with dehydration, increased blood osmolality, and decreased blood volume is not known. Furthermore, there is little information available about associations between activation in osmoreceptive brain regions such as the organum vasculosum of the lamina terminalis and the brain regions implicated in thirst and its satiation in humans. With the objective of investigating the neuroanatomical correlates of dehydration and activation in the ventral lamina terminalis, this study involved exercise-induced sweating in 15 people and measures of regional cerebral blood flow (rCBF) using a functional magnetic resonance imaging technique called pulsed arterial spin labeling. Regional brain activations during dehydration, thirst, and postdrinking were consistent with the network previously identified during systemic hypertonic infusions, thus providing further evidence that the network is involved in monitoring body fluid and the experience of thirst. rCBF measurements in the ventral lamina terminalis were correlated with whole brain rCBF measures to identify regions that correlated with the osmoreceptive region. Regions implicated in the experience of thirst were identified including cingulate cortex, prefrontal cortex, striatum, parahippocampus, and cerebellum. Furthermore, the correlation of rCBF between the ventral lamina terminalis and the cingulate cortex and insula was different for the states of thirst and recent drinking, suggesting that functional connectivity of the ventral lamina terminalis is a dynamic process influenced by hydration status and ingestive behavior.

Drosophila Ndfip is a novel regulator of Notch signaling.

In the Drosophila wing, the Nedd4 ubiquitin ligases (E3s), dNedd4 and Su(dx), are important negative regulators of Notch signaling; they ubiquitinate Notch, promoting its endocytosis and turnover. Here, we show that Drosophila Nedd4 family interacting protein (dNdfip) interacts with the Drosophila Nedd4-like E3s. dNdfip expression dramatically enhances dNedd4 and Su(dx)-mediated wing phenotypes and further disrupts Notch signaling. dNdfip colocalizes with Notch in wing imaginal discs and with the late endosomal marker Rab7 in cultured cells. In addition, dNdfip expression in the wing leads to ectopic Notch signaling. Supporting this, expression of dNdfip suppressed Notch(+/-) wing phenotype and knockdown of dNdfip enhanced the Notch(+/-) wing phenotype. The increase in Notch activity by dNdfip is ligand independent as dNdfip expression also suppressed deltex RNAi and Serrate(+/-) wing phenotypes. The opposing effects of dNdfip expression on Notch signaling and its late endosomal localization support a model whereby dNdfip promotes localization of Notch to the limiting membrane of late endosomes allowing for activation, similar to the model previously shown with ectopic Deltex expression. When dNedd4 or Su(dx) are also present, dNdfip promotes their activity in Notch ubiquitination and internalization to the lysosomal lumen for degradation.

Endocrine and ingestive behavioral responses to fluid deprivation in sheep chronically exposed to ethanol.

Endocrine responses to fluid deprivation/restoration and preference for ethanol solution vs. water were assessed in sheep maintained for 5 months on a 10% ethanol solution as their sole source of fluid. Blood pressure, body weight, plasma composition and hormone levels of the alcohol maintained sheep were all within a normal range, except for high plasma concentrations of ANG II and ALDO. During fluid deprivation, AVP concentration increased and fluid-deprived sheep displayed a natriuresis and then a rehydration anti-natriuresis. Sheep did not drink the 10% ethanol solution avidly upon fluid restoration, preferring to drink steadily over the following 24 h; there was an associated increase in blood alcohol concentration (BAC). PRC, ANG II and ALDO all increased throughout the fluid restoration period, whereas plasma AVP and ANP gradually fell. In a separate experiment when water was also supplied to the sheep, they preferred water to 10% ethanol; however, alcohol intake was not eliminated. Overall, this degree of chronic consumption of 10% ethanol solution did not appear to adversely affect physiological mechanisms concerned with body fluid homeostasis after fluid deprivation conditions.

The role of primordial emotions in the evolutionary origin of consciousness.

Primordial emotions are the subjective element of the instincts which are the genetically programmed behaviour patterns which contrive homeostasis. They include thirst, hunger for air, hunger for food, pain and hunger for specific minerals etc. There are two constituents of a primordial emotion--the specific sensation which when severe may be imperious, and the compelling intention for gratification by a consummatory act. They may dominate the stream of consciousness, and can have plenipotentiary power over behaviour. It is hypothesized that early in animal evolution complex reflex mechanisms in the basal brain subserving homeostatic responses, in concert with elements of the reticular activating system subserving arousal, melded functionally with regions embodied in the progressive rostral development of the telencephalon. This included the emergent limbic and paralimbic areas, and the insula. This phylogenetically ancient organization subserved the origin of consciousness as the primordial emotion, which signalled that the organisms existence was immediately threatened. Neuroimaging confirms major activations in regions of the basal brain during primordial emotions in humans. The behaviour of decorticate humans and animals is discussed in relation to the possible existence of primitive awareness. Neuroimaging of the primordial emotions reveals that rapid gratification of intention by a consummatory act such as ingestion causes precipitate decline of both the initiating sensation and the intention. There is contemporaneous rapid disappearance of particular regions of brain activation which suggests they may be part of the jointly sufficient and severally necessary activations and deactivations which correlate with consciousness [Crick, F. & Koch, C. (2003). A framework for consciousness. NatureNeuroscience,6, 119-126].

Occupational burnout and work engagement: a national survey of dentists in the United Kingdom.

OBJECTIVE: To determine the levels of burnout and work engagement among dentists in the United Kingdom.Study design Postal survey of 500 dentists selected at random from the General Dental Council register. METHODS: Respondents completed a questionnaire pack comprising the Utrecht Work Engagement Scale (UWES-17) and the Maslach Burnout Inventory-Human Services Survey (MBI-HSS), together with questions on demographic characteristics. RESULTS: Approximately 8% of respondents had scores suggestive of burnout on all three scales of the MBI-HSS and a further 18.5% had high scores in two of the domains. Eighty-three percent of respondents had work engagement scores suggestive of moderate or high work engagement. Dentists with postgraduate qualifications and those who work in larger teams had lower burnout scores and more positive work engagement scores. Dentists who spend a greater proportion of their time in NHS practice showed lower work engagement and higher levels of burnout. CONCLUSIONS: Burnout affects a small but significant proportion of dental practitioners in the United Kingdom. A larger proportion of practitioners show low work engagement, suggesting a negative attitude to their work. Higher burnout scores and lower work engagement scores were found in dentists without postgraduate qualifications, those in small teams and in those who spend a greater proportion of their time in NHS practice.

Mitigation assessment of vegetated drainage ditches for collecting irrigation runoff in California.

Widespread contamination of California water bodies by the organophosphate insecticides diazinon and chlorpyrifos is well documented. While their usage has decreased over the last few years, a concomitant increase in pyrethroid usage (e.g., permethrin) (replacement insecticides) has occurred. Vegetated agricultural drainage ditches (VADD) have been proposed as a potential economical and environmentally efficient management practice to mitigate the effects of pesticides in irrigation and storm runoff. Three ditches were constructed in Yolo County, California for a field trial. A U-shaped vegetated ditch, a V-shaped vegetated ditch, and a V-shaped unvegetated ditch were each amended for 8 h with a mixture of diazinon, permethrin, and suspended sediment simulating an irrigation runoff event. Water, sediment, and plant samples were collected spatially and temporally and analyzed for diazinon and permethrin concentrations. Pesticide half-lives were similar between ditches and pesticides, ranging from 2.4 to 6.4 h. Differences in half-distances (distance required to reduce initial pesticide concentration by 50%) among pesticides and ditches were present, indicating importance of vegetation in mitigation. Cis-permethrin half-distances in V ditches ranged from 22 m (V-vegetated) to 50 m (V-unvegetated). Half-distances for trans-permethrin were similar, ranging from 21 m (V-vegetated) to 55 m (V-unvegetated). Diazinon half-distances demonstrated the greatest differences (55 m for V-vegetated and 158 m for V-unvegetated). Such economical and environmentally successful management practices will offer farmers, ranchers, and landowners a viable alternative to more conventional (and sometimes expensive) practices.

Effect of aging on regional cerebral blood flow responses associated with osmotic thirst and its satiation by water drinking: a PET study.

Levels of thirst and ad libitum drinking decrease with advancing age, making older people vulnerable to dehydration. This study investigated age-related changes in brain responses to thirst and drinking in healthy men. Thirst was induced with hypertonic infusions (3.1 ml/kg 0.51M NaCl) in young (Y) and older (O) subjects. Regional cerebral blood flow (rCBF) was measured with positron emission tomography (PET). Thirst activations were identified by correlating rCBF with thirst ratings. Average rCBF was measured from regions of interest (ROI) corresponding to activation clusters in each group. The effects of drinking were examined by correlating volume of water drunk with changes in ROI rCBF from maximum thirst to postdrinking. There were increases in blood osmolality (Y, 2.8 +/- 1.8%; O, 2.2 +/- 1.4%) and thirst ratings (Y, 3.1 +/- 2.1; O, 3.7 +/- 2.8) from baseline to the end of the hypertonic infusion. Older subjects drank less water (1.9 +/- 1.6 ml/kg) than younger subjects (3.9 +/- 1.9 ml/kg). Thirst-related activation was evident in S1/M1, prefrontal cortex, anterior midcingulate cortex (aMCC), premotor cortex, and superior temporal gyrus in both groups. Postdrinking changes of rCBF in the aMCC correlated with drinking volumes in both groups. There was a greater reduction in aMCC rCBF relative to water drunk in the older group. Aging is associated with changes in satiation that militate against adequate hydration in response to hyperosmolarity, although it is unclear whether these alterations are due to changes in primary afferent inflow or higher cortical functioning.

Differential effects of aging on fluid intake in response to hypovolemia, hypertonicity, and hormonal stimuli in Munich Wistar rats.

A significant proportion of aged humans may have impaired thirst and inadequate fluid intake after a period of fluid deprivation. We have studied the water drinking responses, relative to body weight, of Munich Wistar (MW) rats in response to osmotic, hypovolemic, dehydrational, and angiotensin (Ang)-related stimuli as they aged from 3 to 24 months. Young 3-months-old (m.o.) rats had the largest daily fluid intakes and drinking responses to hypertonic and dehydrational stimuli, suggesting that they have accentuated thirst in comparison with older age groups. There were no differences in daily fluid intake from 6-24 m.o.; however, drinking responses to i.p. injection of hypertonic 0.4 mol/liter NaCl gradually declined over this period so that in 24-m.o. rats the response was only half that of 6-m.o. rats. Water intake after 24-h water deprivation also declined gradually over 24 months. Drinking responses to hypovolemia induced by s.c. injection of colloid (polyethylene glycol) were unchanged in 6- to 15-m.o. rats, then declined precipitously in 18- to 24-m.o. rats. Drinking responses to s.c. Ang II or s.c. isoproterenol were not reduced in 24-m.o. rats, nor was the drinking associated with feeding. Therefore, there are specific impairments of water intake in response to hypertonicity and hypovolemia in aged MW rats, but Ang-related drinking is not reduced. Like aged humans, aged MW rats exhibit high plasma atrial natriuretic peptide levels and impaired cardiovascular reflexes that could contribute to the impairment of thirst with age.

Eyelid rejuvenation: a marriage of old and new.

PURPOSE OF REVIEW: Lower lid anatomy and the subtleties of this region have been studied extensively in the past. The variations that are found in the lower eyelid can lead to complications if the surgeon does not have a complete understanding. Lower lid blepharoplasty techniques have progressed over the past from simple skin excisions to midface and lower eyelid repositioning. With these modifications, our understanding of the anatomy and the function of the lower eyelid improve. This review highlights the findings of lower eyelid anatomy and rejuvenating techniques reported over the past year. RECENT FINDINGS: Over this past year anatomic studies have been performed focusing on the aging eye and midface in both Asians and non-Asians. Controversial work has been presented using an injectable (phosphatidylcholine) to ablate fat in the lower eyelids. A myriad of articles have discussed various options for combined midface and lower eyelid rejuvenation. The age-old argument of transconjunctival vs skin muscle techniques has been presented. More recent debates over fat volumetric preservation continue. Finally, a highlight of this year was a retrospective study looking at a conservative approach to blepharoplasty. SUMMARY: This has been a year of confirmation of old techniques and anatomic findings and a year of increasing complexity in midface lower eyelid rejuvenation. What is clear is that no one technique is ideal for every patient. A basic understanding of lower eyelid anatomy, preoperative evaluation, and a grasp of the multiple techniques will allow us to formulate a treatment algorithm that can be safe and effective for our patients.

Cardiovascular effects of long-term central and peripheral administration of urocortin, corticotropin-releasing factor, and adrenocorticotropin in sheep.

The neuroendocrine hormones ACTH and corticotropin- releasing factor (CRF), which are involved in the stress response, have acute effects on arterial pressure. New evidence indicates that urocortin (UCN), the putative agonist for the CRF type 2 receptor, has selective cardiovascular actions. The responses to long-term infusions of these hormones, both peripherally and centrally, in conscious animals have not been studied. Knowledge of the long-term effects is important because they may differ considerably from their acute actions, and stress is frequently a chronic stimulus. The present experiments investigated the cardiovascular effects of CRF, UCN, and ACTH in conscious sheep. Infusions were made either into the lateral cerebral ventricles (i.c.v.) or i.v. over 4 d at 5 microg/h. UCN infused i.c.v. or i.v. caused a prolonged increase in heart rate (HR) (P < 0.01) and a small increase in mean arterial pressure (MAP) (P < 0.05). CRF infused i.c.v. or i.v. progressively increased MAP (P < 0.05) but had no effect on HR. Central administration of ACTH had no effect, whereas systemic infusion increased MAP and HR (P < 0.001). In conclusion, long-term administration of these three peptides associated with the stress response had prolonged, selective cardiovascular actions. The striking finding was the large and sustained increase in HR with i.c.v. and i.v. infusions of UCN. These responses are probably mediated by CRF type 2 receptors because they were not reproduced by infusions of CRF.

Physiological and pathophysiological influences on thirst.

Thirst motivates animals to seek fluid and drink it. It is regulated by the central nervous system and arises from neural and chemical signals from the periphery interacting in the brain to stimulate a drive to drink. Our research has focussed on the lamina terminalis and the manner in which osmotic and hormonal stimuli from the circulation are detected by neurons in this region and how that information is integrated with other neural signals to generate thirst. Our studies of osmoregulatory drinking in the sheep and rat have produced evidence that osmoreceptors for thirst exist in the dorsal cap of the organum vasculosum of the lamina terminalis (OVLT) and in the periphery of the subfornical organ, and possibly also in the median preoptic nucleus. In the rat, the hormones angiotensin II and relaxin act on neurons in the periphery of the subfornical organ to stimulate drinking. Studies of human thirst using functional magnetic resonance imaging (fMRI) techniques show that systemic hypertonicity activates the lamina terminalis and the anterior cingulate cortex, but the neural circuitry that connects sensors in the lamina terminalis to cortical regions subserving thirst remains to be determined. Regarding pathophysiological influences on thirst mechanisms, both excessive (polydipsia) and inadequate (hypodisia) water intake may have dire consequences. One of the most common primary polydipsias is that observed in some cases of schizophrenia. The neural mechanisms causing the excessive water intake in this disorder are unknown, so too are the factors that result in impaired thirst and inadequate fluid intake in some elderly humans.

Hand rejuvenation.

Both skin and subcutaneous tissues are targeted in this multistage hand rejuvenation protocol. Topical therapies and intense pulsed light are used for skin thickening, rejuvenation, and improvement of age spots and leathery texture. Autologous fat is injected into multiple tissue layers to fill out underlying tissue. Excess skin is excised with a small, well-hidden incision on the ulnar surface.