Disruption of NREM sleep and sleep-related spatial memory consolidation in mice lacking adult hippocampal neurogenesis

Cellular plasticity at the structural level and sleep at the behavioural level are both essential for memory formation. The link between the two is not well understood. A functional connection between adult neurogenesis and hippocampus-dependent memory consolidation during NREM sleep has been hypothesized but not experimentally shown. Here, we present evidence that during a three-day learning session in the Morris water maze task a genetic knockout model of adult neurogenesis (Cyclin D2^-/-) showed changes in sleep macro- and microstructure. Sleep EEG analyses revealed a lower total sleep time and NREM fraction in Cyclin D2^-/- mice as well as an impairment of sleep specific neuronal oscillations that are associated with memory consolidation. Better performance in the memory task was associated with specific sleep parameters in wild-type, but not in Cyclin D2^-/- mice. In wild-type animals the number of proliferating cells correlated with the amount of NREM sleep. The lack of adult neurogenesis led to changes in sleep architecture and oscillations that represent the dialog between hippocampus and neocortex during sleep. We suggest that adult neurogenesis-as a key event of hippocampal plasticity-might play an important role for sleep-dependent memory consolidation and modulates learning-induced changes of sleep macro- and microstructure.

Chapter One - Ubiquitination and Deubiquitination of G Protein-Coupled Receptors

The seven-transmembrane containing G protein-coupled receptors (GPCRs) constitute the largest family of cell-surface receptors. Transmembrane signaling by GPCRs is fundamental to many aspects of physiology including vision, olfaction, cardiovascular, and reproductive functions as well as pain, behavior and psychomotor responses. The duration and magnitude of signal transduction is tightly controlled by a series of coordinated trafficking events that regulate the cell-surface expression of GPCRs at the plasma membrane. Moreover, the intracellular trafficking profiles of GPCRs can correlate with the signaling efficacy and efficiency triggered by the extracellular stimuli that activate GPCRs. Of the various molecular mechanisms that impart selectivity, sensitivity and strength of transmembrane signaling, ubiquitination of the receptor protein plays an important role because it defines both trafficking and signaling properties of the activated GPCR. Ubiquitination of proteins was originally discovered in the context of lysosome-independent degradation of cytosolic proteins by the 26S proteasome; however a large body of work suggests that ubiquitination also orchestrates the downregulation of membrane proteins in the lysosomes. In the case of GPCRs, such ubiquitin-mediated lysosomal degradation engenders long-term desensitization of transmembrane signaling. To date about 40 GPCRs are known to be ubiquitinated. For many GPCRs, ubiquitination plays a major role in postendocytic trafficking and sorting to the lysosomes. This chapter will focus on the patterns and functional roles of GPCR ubiquitination, and will describe various molecular mechanisms involved in GPCR ubiquitination.

FATAL INFECTION OF IRRADIATED WHITE MICE WITH EUROPEAN TYPHUS BY THE INTRA-ABDOMINAL ROUTE

A fatal infection of irradiated white mice with the Breinl strain of European typhus has been established and passed serially for 22 passages by the intra-abdominal route. Rickettsiae were abundant and easily demonstrable in the moribund or dead mice. The mortality of irradiated mice infected with passage material (peritoneal washings or blood) was nearly 100 per cent as contrasted to no mortality in the control mice given the same dose of x-ray (450 R) and the same volume of fluid intra-abdominally. (The observation period of control mice was arbitrarily limited to 14 days.) After eighteen passages in irradiated mice no increase in virulence for non-irradiated adult mice was detected. After passage in guinea pigs, the rickettsial infection deriving from the mouse passage material was identical with the Breinl strain as judged by fever, cross immunity tests, and brain lesions in sections.

THE EXPERIMENTAL INFECTION OF THE HUMAN BODY LOUSE, PEDICULUS HUMANUS CORPORIS, WITH MURINE AND EPIDEMIC LOUSE-BORNE TYPHUS STRAINS

Experiments are described which demonstrate that human body lice (Pediculus humanus corporis), were infected experimentally with murine and epidemic louse-borne strains of typhus fever by feeding on suitably prepared rabbits. Details of the two methods of infection, the "bleb technique" and the "I.V. technique," are presented. It is concluded that the experimental infection of human lice with typhus can be accomplished very easily and rapidly with these methods. The possible applications of the method are discussed.

Endogenous lung stem cells and contribution to disease

Epithelial branching during the process of lung development results in the establishment of distinct functional zones, each of which is characterized by a unique cellular composition and repertoire of local progenitor cells. Significant new insights into cellular and molecular mechanisms of epithelial maintenance that provide insights into the pathophysiology of lung disease have been made in recent years. This review focuses on the complex structure-function relationship in the airway epithelium, how this epithelium is maintained in the normal state and repaired following injury, and how deregulation may contribute to airway disease and cancer.

Effects of culturing on the population structure of a hyperthermophilic virus

The existence of a culturing bias has long been known when sampling organisms from the environment. This bias underestimates microbial diversity and does not accurately reflect the most ecologically relevant species. Until now no study has examined the effects of culture bias on viral populations. We have employed culture-independent methods to assess the diversity of Sulfolobus spindle-shaped viruses (SSVs) from extremely hyperthermal environments. This diversity is then compared to the viral diversity of cultured samples. We detected a clear culturing bias between environmental samples and cultured isolates. This is the first study identifying a culture bias in a viral population.

Potential of solid phase extraction disks to aid determination of dislodgeable foliar residues of chlorpyriphos, malathion, diazinon, and acephate

The utility of solid phase extraction (SPE) for concentrating four organophosphate insecticides from solutions of water and sodium dioctyl sulfosuccinate, a surfactant, was evaluated. Reverse phase (C18, octadecyl bonded silica) sorbent in the form of a disk was the SPE medium evaluated. Chlorpyriphos, malathion, and diazinon, but not acephate, were retained on and eluted from the SPE disks. For pesticides that were retained on SPE disks, recoveries from the disks were equal to or higher than recoveries achieved by solvent partitioning. Dislodgeable foliar residues of acephate were successfully concentrated for analysis by lyophilization of water-surfactant solutions. Recoveries of pesticides from SPE disks stored at -15 degrees C for one week were equal to or higher than those of pesticides stored in water-surfactant for one week at -15 degrees C. Malathion- and diazinon-fortified samples in watersurfactant and on SPE disks were prepared in one state and shipped for analysis in another state. Pesticides in the water-surfactant samples were concentrated by solvent partitioning and were underestimated by 41% (diazinon) and 16% (malathion). Conversely, diazinon samples on the SPE disks were on average underestimated by 3% and malathion was overestimated by an average of 55%. The overestimation of malathion was attributed to a matrix effect during analysis associated with the presence of surfactant, which was retained on and subsequently eluted from the SPE disks. The retention of surfactant by the SPE disks and its subsequent elution may considerably limit their usefulness in determination of dislodgeable foliar residues.

Sustainable soil management practices and quality of potato grown on erodible lands

Land productivity can decline when top soil is lost. In Kentucky, limited resource farmers often produce vegetable crops on erodible lands. The objectives of this study were 1) to quantify the impact of three soil management practices (SMPs) on quantity of potato produced on erodible land, 2) to evaluate the impact of pyrethrin and azadirachtin insecticides on potato tuber quality, and 3) to assess the impact of yard waste compost on the chemical composition (ascorbic acid, free sugars, phenol contents) of potato tubers. Potatoes (Solanum tuberosum L. cv. Kennebec) were grown in a silty loam soil of 10% slope. Plots (n= 18) were 3.7 m wide and 22 m long (10% slope), with metal borders of 20 cm above ground level. Two botanical insecticides, Multi-Purpose Insecticide (containing pyrethrin 0.2%) and Neemix 4EC (containing 0.25% azadirachtin) were sprayed twice on potato foliage during each of two growing seasons (1997 and 1999) at the recommended rates of 6 lbs and 2 gallons.acre(-1), respectively. The SMPs were tall fescue strips (FS) intercropped between each two potato rows, soil mixed with yard waste compost (COM) and no-mulch (NM) treatment (roto-tilled bare soil). The experimental designwas a 2 x 3 x 3 factorial with main factors of two insecticides and three SMPs replicated three times. Average potato yield was lowest in NM and FS and highest in COM treatments. Yield obtained from the bottom of the plots was greater than that obtained from the top of plots. Tuber defects (rot, scab, sun green, hollow heart, necrosis, and vascular discoloration) were significantly different between the two growing seasons. The two insecticidal treatments did not have much influence on potato yield or tuber defects. Tubers obtained from tall fescue treatments had low levels of ascorbic acid and reducing sugars compared to compost treatments.

Pyrethrins and piperonyl butoxide residues on potato leaves and in soil under field conditions

Residues of pyrethrin-I (Py-I) and pyrethrin-II (Py-II), the major insecticidal components of the pyrethrum daisy (Tanacetum cinerariifolium) as well as residues of piperonyl butoxide (PBO, a pyrethrum synergist) were determined in soil and on potato foliage grown under field conditions. A pyrethrum formulation (Multi-Purpose Insecticide) containing the three active ingredients was sprayed twice at the rate of 6 lbs of formulated product.acre(-1) ( 5.4 and 27.2 g A.I. of pyrethrin and PBO, respectively) on potato foliage during the growing season. In soil, three management practices (yard waste compost, grass filter strips, and a no mulch treatment) were used to study the impact of surface soil characteristics on the amount of pyrethrins (Pys) and PBO retained in soil. Soil samples and potato leaves were collected at different time intervals after spraying. Samples were purified and concentrated using solid-phase extraction columns containing C18-Octadecyl bonded silica. Residues were quantified by high-performance liquid chromatograph equipped with a UV detector. The first spray resulted in mean initial deposits of 0.18, 0.40, and 0.99 microg.g(-1) potato leaves for Py-I, Py-II, and PBO, respectively. Residues in soil were higher in compost treatments compared to no mulch treatments.

ORTHOSTATIC HYPOTENSION: A Potential SIDE EFFECT of Psychiatric Medications

1. Orthostatic hypotension is a major underrecognized side effect of antipsychotic and antidepressant medications. It has been associated with falls, fractures, and lacerations, particularly in the elderly. 2. Orthostatic vital signs need to be routinely measured in patients susceptible to orthostasis. A standardized procedure should be available and must include a stable baseline measurement in the supine position at 30 seconds and 2 minutes in the sitting or standing position. 3. Measures to counteract orthostasis include nutrition/hydration assessment, environmental safety, and patient teaching.

When Staff are ASSAULTED: A Nursing Consultation Support Service

Increasing patient to staff assaults led to the development of a Nursing Consultation Service, which can respond to the needs of assault victims and set the tone for institutional attitudes of nonblaming concern. A member of the consultation service meets with each known assault victim to review the incident, offer support, and provide assistance in addressing issues aroused by the incident. Implementation of this service and the use of a continuous monitor to track assault incidents is vital to highlight problem areas and develop assault prevention strategies.

Rapid estimation of potato tuber total protein content with coomassie brilliant blue G-250

A new method for measuring protein with Coo-massie Brilliant Blue G-250 has been adapted for use as a screening method in a potato tuber protein improvement breeding program. The method is simple, fast and inexpensive, and has successfully estimated the total protein content of a broad range of tuber genotypes having dissimilar amino acid profiles and tuber maturities. Correlation between the Coomassie method and a modified micro-Kjeldahl method, the standard method used in the potato breeding program, was 0.93. Free amino acids and other compounds which interfere with other methods for measuring protein do not interfere with the Coomassie Brilliant Blue procedure.