Determination of Postmortem Interval in Mice.

Despite the major use of mice in biomedical research, little information is available with regard to identifying their postmortem changes and using that information to determine the postmortem interval (PMI), defined as the time after death. Both PMI and environmental conditions influence decomposition (autolysis and putrefaction) and other postmortem changes. Severe decomposition compromises lesion interpretation and disease detection and wastes limited pathology resources.

Physiologic and Behavioral Effects in Mice Anesthetized with Isoflurane in a Red-tinted or a Traditional Translucent Chamber.

Isoflurane has been characterized as a distressing agent for rodents, causing both physiologic and behavioral effects. Using a "darkened home cage" has been recommended during CO₂ administration for rodent euthanasia; this is arguably a similar animal experience to anesthetic induction with isoflurane. Based on the premise that rodents perceive red light as darkness via the primary optic tract, we compared physiologic and behavioral markers of stress in 2 inbred strains of mice (C57BL/6J and BALB/cJ) anesthetized with isoflurane in either a red-tinted (dark) induction chamber or a traditional translucent induction chamber.

Worldwide effects of non-native species on species-area relationships.

Non-native species have invaded most parts of the world, and the invasion process is expected to continue and accelerate. Because many invading non-native species are likely to become permanent inhabitants, future consideration of species-area relationships (SARs) should account for non-native species, either separately or jointly with native species. If non-native species occupy unused niches and space in invaded areas and extinction rate of native species remains low (especially for plants), the resultant SARs (with both native and non-native species) will likely be stronger.

Changes in taxonomic and phylogenetic diversity in the Anthropocene.

To better understand how ecosystems are changing, a multifaceted approach to measuring biodiversity that considers species richness (SR) and evolutionary history across spatial scales is needed. Here, we compiled 162 datasets for fish, bird and plant assemblages across the globe and measured how taxonomic and phylogenetic diversity changed at different spatial scales (within site diversity and between sites spatial diversity). Biodiversity change is measured from these datasets in three ways: across land use gradients, from species lists, and through sampling of the same locations across two time periods.

Land snail dispersal, abundance and diversity on green roofs.

We present the first major systematic study of land snail diversity on green roofs. We surveyed 27 green roofs and the adjacent ground habitat in six major cities in the southeastern United States. We found a total of 18 species of land snails, with three considered to be non-native or invasive species.

Pattern and process of biotic homogenization in the New Pangaea.

Human activities have reorganized the earth's biota resulting in spatially disparate locales becoming more or less similar in species composition over time through the processes of biotic homogenization and biotic differentiation, respectively. Despite mounting evidence suggesting that this process may be widespread in both aquatic and terrestrial systems, past studies have predominantly focused on single taxonomic groups at a single spatial scale. Furthermore, change in pairwise similarity is itself dependent on two distinct processes, spatial turnover in species composition and changes in gradients of species richness.

Altered expression of zonula occludens-2 precedes increased blood-brain barrier permeability in a murine model of fulminant hepatic failure.

Brain edema secondary to increased blood-brain barrier (BBB) permeability is a lethal complication in fulminant hepatic failure (FHF). Intact tight junctions (TJ) between brain capillary endothelial cells are critical for normal BBB function. However, the role of TJ in FHF has not been explored.

Assessing the value of ureteral stent placement in pediatric kidney transplant recipients.

Background: Ureteral stent placement at kidney transplantation may reduce stenosis or leakage (S/L) complication rates. However, stent placement may also increase risk for early urinary tract infection (early UTI; <3 months after transplant) and BK virus allograft nephropathy (BKVAN). In children, the usefulness of stent placement is not well defined.

Pathway analysis of primary central nervous system lymphoma.

Primary central nervous system (CNS) lymphoma (PCNSL) is a diffuse large B-cell lymphoma (DLBCL) confined to the CNS. A genome-wide gene expression comparison between PCNSL and non-CNS DLBCL was performed, the latter consisting of both nodal and extranodal DLBCL (nDLBCL and enDLBCL), to identify a "CNS signature." Pathway analysis with the program SigPathway revealed that PCNSL is characterized notably by significant differential expression of multiple extracellular matrix (ECM) and adhesion-related pathways.

The botanist effect revisited: plant species richness, county area, and human population size in the United States.

The "botanist effect" is thought to be the reason for higher plant species richness in areas where botanists are disproportionately present as an artefactual consequence of a more thorough sampling. We examined whether this was the case for U.S.

Aging elevates metabolic gene expression in brain cholinergic neurons.

The basal forebrain (BF) cholinergic system is selectively vulnerable in human brain diseases, while the cholinergic groups in the upper pons of the brainstem (BS) resist neurodegeneration. Cholinergic neurons (200 per region per animal) were laser-microdissected from five young (8 months) and five aged (24 months) F344 rats from the BF and the BS pontine lateral dorsal tegmental/pedunculopontine nuclei (LDTN/PPN) and their expression profiles were obtained. The bioinformatics program SigPathway was used to identify gene groups and pathways that were selectively affected by aging.

Establishment of cholinergic neuron-like cell lines with differential vulnerability to nitrosative stress.

Cholinergic cell lines were established by fusion of embryonic day 17 wild-type neurons from rat basal forebrain (BF) and upper brainstem (BS) with N18tg neuroblastoma cells. Isolated clones expressed choline acetyltransferase (ChAT) and neuronal nitric oxide synthase (nNOS) activities that were increased upon differentiation with retinoic acid. Clones from the BF expressed high levels of the tyrosine kinase type A (TrkA) receptor expression and activation of the mitogen-activated kinase ERK2 upon treatment with nerve growth factor.

Aging causes partial loss of basal forebrain but no loss of pontine reticular cholinergic neurons.

Cholinergic degeneration occurs in several neurodegenerative diseases. To investigate whether normal aging causes selective neurodegeneration, we compared counts of cholinergic neurons in the medial septum/vertical limb of the diagonal band and pedunculopontine and laterodorsal tegmental nuclei of the brainstem in young and aged Long-Evans rats characterized for their spatial learning ability in the Morris water maze. A subset of aged rats (aged-unimpaired) learned the spatial learning task as young rats, whereas another group (age-impaired) showed poorer learning than young animals.

Aging is neuroprotective during global ischemia but leads to increased caspase-3 and apoptotic activity in hippocampal neurons.

Previously, we found a significantly greater number of surviving CA1 neurons to global ischemia in the aged (24-month-old) F344 rats than in young (4-month-old) rats. The present study tests the hypothesis that aging retards neuronal death in the hippocampal CA1 region following cerebral ischemia. The CA1 "living cell ratio" was significantly greater in aged than in young rats at three days (62+/-8% vs.

Practical aspects of radioligand binding.

Radioligand binding has been used for many years to identify new binding sites, characterize receptors, and identify novel ligands. Although various techniques have been developed to improve the efficiency of preparing the biological source of the receptors and for detecting bound radioligand, the principles of the assays remain the same. This unit reviews theory and provides examples of the parameters that can be calculated from radioligand binding data to characterize ligand-receptor interactions.

Matrix metalloproteinase-9 contributes to brain extravasation and edema in fulminant hepatic failure mice.

Background/aims: Fulminant hepatic failure (FHF) can be dreadful. When coma sets in, brain edema develops taking FHF into a lethal course. Mechanisms of brain extravasation leading to brain edema remain incompletely understood.

Aging blunts ischemic-preconditioning-induced neuroprotection following transient global ischemia in rats.

The present study examines the hypothesis that aging defined by the 50% survival age compromises neuroprotection afforded by ischemic preconditioning (IPC). Sixty-four male F344 rats aged 4- and 24-months, respectively, were subjected to IPC, (3-min ischemia) or sham-surgery followed by 10-min (full) ischemia or sham-surgery 2 days later. There were 4 groups at each age: sham-surgery-sham-surgery (SS), preconditioning-sham-surgery (PS), preconditioning-ischemia (PI) and sham-surgery-ischemia (SI) groups.

Increased severity of acute cerebral ischemic injury correlates with enhanced stem cell induction as well as with predictive behavioral profiling.

An 8-vessel-occlusion (8VO) method was developed to compare with the conventional 4-vessel-occlusion (4VO) in hippocampal ischemic damage and progenitor cell induction 10 days following ischemia in female rats. Eight posture-relevant tests were performed following ischemia to correlate grades of postural abnormality with the histological outcome. The total hippocampal living cell ratio including 7 hippocampal subregions in 8VO group (n=11) was much lower than that in 4VO group (n=10, 51+/-5% vs.

Hippocampal progenitor cells express nestin following cerebral ischemia in rats.

This study addresses whether hippocampal progenitor cells express nestin following cerebral ischemia in rats. Cell counts within the hippocampal hilus were significantly greater following severe (eight-vessel occlusion) ischemia than following intermediate (four-vessel occlusion) ischemia (1527+/-87/mm2 vs. 918+/-71/mm2).

Brain cholinergic vulnerability: relevance to behavior and disease.

The major populations of cholinergic neurons in the brain include two "projection" systems, located in the pontine reticular formation and in the basal forebrain. These two complexes comprise, in part, the anatomical substrates for the "ascending reticular activating system" (ARAS). The pontine cholinergic system relays its rostral influences mainly through thalamic intralaminar nuclei, but it also connects to the basal forebrain and provides a minor innervation of cortex.

The role of glutathione in nitric oxide donor toxicity to SN56 cholinergic neuron-like cells.

Our study was designed to determine if compounds used experimentally to generate nitric oxide excess differ in ability to elicit degenerative stress to cholinergic neurons and, if so, what mechanisms account for their differences. Nitric oxide donors are often used experimentally in attempts to emulate the bioactivities of endogenous NO, but the pharmacological actions of NO donors can vary dramatically according to the species of NO (NOx) and other agents (e.g.

Pontine cholinergic neurons depend on three neuroprotection systems to resist nitrosative stress.

Brainstem cholinergic populations survive in neurodegenerative disease, while basal forebrain cholinergic neurons degenerate. We have postulated that variable resistance to oxidative stress may in part explain this. Rat primary cultures were used to study the effects of several nitrosative/oxidative stressors on brainstem (upper pons, containing pedunculopontine and lateraldorsal tegmental nuclei; BS) cholinergic neurons, comparing them with medial septal (MS), and striatal cholinergic neurons.

PBDEs in the San Francisco Bay Area: measurements in harbor seal blubber and human breast adipose tissue.

To explore the levels of polybrominated diphenyl ethers (PBDEs) in California, samples from 11 archived harbor seals (Phoca vitulina Richardsi) from the San Francisco Bay and breast adipose tissue samples from 23 women were analyzed. The levels of PBDEs in human tissue samples were in the low ng/g fat range, with PBDEs 47, 153, 154, 99, and 100 as the major congeners. Average sigma PBDEs (86 ng/g fat) in these California women are the highest human levels reported to date.

Atmospheric pressure ionization LC-MS-MS determination of urushiol congeners.

This paper describes atmospheric pressure ionization (API) LC-MS-MS determination of urushiols, 3-n-alkenyl- and -alkyl-substituted catechols responsible for poison oak dermatitis. Urushiol was isolated from Western poison oak according to the method of Elsohly et al. (1) (J.

TITANOTHERE ALLOMETRY, HETEROCHRONY, AND BIOMECHANICS: REVISING AN EVOLUTIONARY CLASSIC.

A reanalysis of Osborn's titanothere data indicates that extrapolative growth of a constant allometric relationship alone ("hypermorphosis") does not account for the trend toward body and horn size increase. Empirically, we also observe possible positive changes in the y-intercept ("predisplacement" or early onset of development), and possibly, changes in the slope ("acceleration/neoteny" or changes in growth rate) between the Oligocene and Eocene groups. Theoretically, these may be responses to more massive body shapes, perforce accompanying size increase, which increase the amount of force to which the horns were subjected.