Identification and Distribution of Phenylacetic Acid in the Brain of the Rat

Abstract: Phenylacetic acid, the major metabolite of phenylethylamine, has been identified and quantitated in rat brain regions by capillary column high-resolution gas chromatography mass spectrometry. Its distribution is heterogeneous and correlates with that of phenylethylamine. The values obtained were (ng/g ± SEM): whole brain, 31.2 ± 2.7; caudate nucleus, 64.6 ± 6.5; hypothalamus, 60.1 ± 7.4; cerebellum, 31.3 ± 2.9; brainstem, 33.1 ± 3.3, and the "rest," 27.6 ± 3.0.     

Borrelia sp. in ticks recovered from white-tailed deer in Alabama.

Six hundred sixty-five hunter-killed white-tailed deer (Odocoileus virginianus) from 18 counties in Alabama (USA) were examined for ticks. Most of the collections were made at state-operated wildlife management areas. Four species of ticks (n = 4,527) were recovered: the lone star tick Amblyomma americanum (n = 482); the Gulf Coast tick A. maculatum (n = 11); the winter tick Dermacentor albipictus (n = 1,242); and the black-legged tick Ixodes scapularis (n = 2,792). Fifty-six percent of the ticks (n = 2,555) were examined for Borrelia sp. spirochetes using an immunofluorescent, polyclonal antibody assay. Spirochetes were detected in I. scapularis (five females, seven males) from Barbour, Butler, Coosa, and Lee counties and A. americanum (four males, four nymphs) from Hale, Lee, and Wilcox counties. Area-specific prevalences in ticks were as high as 3.3% for I. scapularis and 3.8% for A. americanum.     

Identification and Distribution of m- and p-Hydroxyphenylacetic Acids in the Brain of the Rat

The m and p isomers of hydroxyphenylacetic acid have been identified and quantitated in whole rat brain and in several regions using a capillary column high resolution gas chromatography–mass spectrometry procedure. Their concentrations were: for m-hydroxyphenylacetic acid (mean ± S.E., number of determinations in parentheses)—whole brain, 2.3 ± 0.3 ng/g (7); hypothalamus, 1.2 ± 0.3 ng/g (5); caudate nucleus, 5.5 ± 0.6 ng/g (5); brain stem, 1.8 ± 0.1 ngig (5); cerebellum, 1.2 ± 0.1 ng/g (5) and the “rest,” 1.7 ± 0.1 ng/g (5); and for p-hydroxyphenylacetic acid–whole brain, 10.6 ± 0.7 ng/g (7); hypothalamus, 4.5 ± 0.1 ng/g (4); caudate nucleus, 28.3 ±1.6 ng/g (5); brain stem, 8.6 ± 0.6 ng/g (5); cerebellum, 8.1 ± 0.4 ng/g (9, and the “rest,” 5.3 ± 0.5 ng/g (5). This heterogeneous distribution parallels closely that exhibited by their respective precursor amines, m- and p-tyramine.     

Fatal Asphyxiation in Bottlenose Dolphins (Tursiops truncatus) from the Indian River Lagoon

Multiple single case reports of asphyxiation in dolphins caused by fish lodged in the esophagus exist. However, the significance of this cause of mortality in a single population has not been documented. We performed a retrospective evaluation of pathology records from stranded bottlenose dolphins (Tursiops truncatus) from the Indian River Lagoon to evaluate the impact of this cause of death on this population. From 1997 to 2011, asphyxiation due to choking was identified as the cause of death in 14 of 350 cases (4%). Sampling of an unrelated but adjacent population over this same period yielded 186 necropsy cases of bottlenose dolphins with no cases of asphyxiation. Asphyxiated animals presented with a fish lodged in the cranial esophagus associated with a dislocated and obstructed or compressed larynx. There was no clear sex predilection. Affected animals included 12 adults and two juveniles. The fish species involved included sheepshead, black chin tilapia and striped mojarra. In five cases, recreational fishing gear was also present. Cetacean choking is related to selection of prey fish species with strong dorsal spines and may be secondarily associated with fish attached to fishing gear. Prey abundance and dolphin behavior may influence these selections. Environmental alterations leading to changes in prey availability or increased interactions with fishing gear may change the significance of fatal choking in dolphin populations.     

Two new species of Stivalius (Siphonaptera--Pygiopsyllidae--Pygiopsyllinae) from Indonesia

The fleas, S. meridionalis n. sp. from Timor and S. franciscae n. sp. from Sulawesi, Indonesia are described and illustrated. S. meridionalis was collected in Central Timor (Timor Tengah) at elevations between 930 m and 1,520 m, mainly from the murine rodent Rattus tanezumi, although one specimen was recovered from a house shrew, Suncus murinus. S. franciscae was collected in Central Sulawesi (Sulawesi Tengah) at known elevations between 950 m and 2,255 m from six species of native endemic murine rodents, especially Rattus hoffmanni, and from two species of commensal murine rodents. One specimen of S. franciscae was also collected from the native endemic murine Paruromys dominator in North Sulawesi (Sulawesi Utara) at 1,780 m. These two new flea species are compared with the previously described taxa included in the genus Stivalius sensu stricto.     

Tick infestations of birds in coastal Georgia and Alabama

Mist-netted birds were examined for ticks on Jekyll Island, Glynn Co., Georgia (32 bird species) in 1996-1998, and at Fort Morgan, Baldwin Co., Alabama (36 species) in 1998 during fall migration. Sixty-two (14.7%) of 423 birds from Jekyll Island and 22 (13.3%) of 165 birds from Fort Morgan were infested with ticks. The mean number of ticks per infested bird was 2.0 on Jekyll Island and 6.3 at Fort Morgan. Ten species of birds were infested with ticks on Jekyl1 Island where 87% of all ticks were recovered from 3 species: the common yellowthroat (Geothlypis trichas), gray catbird (Dumetella carolinensis), and northern waterthrush (Seiurus noveboracensis). Eight species of birds were infested with ticks at Fort Morgan where 83% of all ticks were recovered from 3 species: the brown thrasher (Toxostoma rufum), swamp sparrow (Melospiza georgiana), and common yellowthroat. Six species of ticks (Amblyomma americanum, Amblyomma maculatum, Haemaphysalis leporispalustris, Ixodes brunneus, Ixodes minor, and Ixodes scapularis) were recovered from the Georgia birds, whereas 3 species (A. maculatum, H. leporispalustris, and Ixodes dentatus) were recovered from the Alabama birds. Attempts to isolate Borrelia burgdorferi sensu stricto, the etiologic agent of Lyme borreliosis, from Ixodes spp. ticks recovered from birds were unsuccessful.     

Ectoparasites and gastrointestinal helminths of southern flying squirrels in southeast Georgia

Southern flying squirrels (Glaucomys volans) from southeastern Georgia were examined for ectoparasites and gastrointestinal helminths. Ten species of ectoparasites were recovered, including 3 species of sucking lice (Hoplopleura trispinosa, Microphthirus uncinatus, and Neohaematopinus sciuropteri), 1 species of flea (Orchopeas howardi), 2 species of ticks (Amblyomma maculatum and Ixodes scapularis), 3 species of mesostigmatid mites (Androlaelaps casalis, A. fahrenholzi, and Haemogamasus ambulans), and 1 species of chigger (Leptotrombidium peromysci). Only the sucking lice and fleas were common on this host. M. uncinatus is reported for the first time from eastern North America. The 2 most commonly collected ectoparasites, N. sciuropteri (prevalence = 63%) and O. howardi (prevalence = 47%), have previously been shown to be vectors of the rickettsial zoonotic agent that causes sporadic epidemic typhus. Also, 3 nematodes (Citellinema bifurcatum, Strongyloides robusius, and Syphacia thompsoni), 1 unidentified cestode, and 1 acanthocephalan (Moniliformis clarki) were found in flying squirrel gastrointestinal tracts. With the exception of S. thompsoni, which was common and relatively abundant in the cecum (prevalence = 94%, intensity = 51+/-12), both the prevalence and intensity of helminth parasites were low. The nematode S. thompsoni and the acanthocephalan M. clarki are new state records for tree squirrels in Georgia.     

Knockout Serum Replacement Promotes Cell Survival by Preventing BIM from Inducing Mitochondrial Cytochrome C Release

Knockout serum replacement (KOSR) is a nutrient supplement commonly used to replace serum for culturing stem cells. We show here that KOSR has pro-survival activity in chronic myelogenous leukemia (CML) cells transformed by the BCR-ABL oncogene. Inhibitors of BCR-ABL tyrosine kinase kill CML cells by stimulating pro-apoptotic BIM and inhibiting anti-apoptotic BCL2, BCLxL and MCL1. We found that KOSR protects CML cells from killing by BCR-ABL inhibitors—imatinib, dasatinib and nilotinib. The protective effect of KOSR is reversible and not due to the selective outgrowth of drug-resistant clones. In KOSR-protected CML cells, imatinib still inhibited the BCR-ABL tyrosine kinase, reduced the phosphorylation of STAT, ERK and AKT, down-regulated BCL2, BCLxL, MCL1 and up-regulated BIM. However, these pro-apoptotic alterations failed to cause cytochrome c release from the mitochondria. With mitochondria isolated from KOSR-cultured CML cells, we showed that addition of recombinant BIM protein also failed to cause cytochrome c release. Besides the kinase inhibitors, KOSR could protect cells from menadione, an inducer of oxidative stress, but it did not protect cells from DNA damaging agents. Switching from serum to KOSR caused a transient increase in reactive oxygen species and AKT phosphorylation in CML cells that were protected by KOSR but not in those that were not protected by this nutrient supplement. Treatment of KOSR-cultured cells with the PH-domain inhibitor MK2206 blocked AKT phosphorylation, abrogated the formation of BIM-resistant mitochondria and stimulated cell death. These results show that KOSR has cell-context dependent pro-survival activity that is linked to AKT activation and the inhibition of BIM-induced cytochrome c release from the mitochondria.     

Haemodipsus brachylagi n. sp. (Phthiraptera: Anoplura: Polyplacidae), a new sucking louse from the pygmy rabbit in Nevada

The male and female of Haemodipsis brachylagi n. sp. (Phthiraptera: Anoplura) are described from specimens collected from a pygmy rabbit, Brachylagus idahoensis (Merriam) (Lagomorpha: Leporidae), from Nevada. Morphological features that differentiate the new species from other known species of Haemodipsus are elucidated, and an identification key to both sexes of the 3 species now known from this genus in North America is included. Geographical distributions of the other 4 species of Haemodipsus known from other parts of the world are highlighted.     

Molecular basis for a direct interaction between the Syk protein-tyrosine kinase and phosphoinositide 3-kinase

After engagement of the B cell receptor for antigen, the Syk protein-tyrosine kinase becomes phosphorylated on multiple tyrosines, some of which serve as docking sites for downstream effectors with SH2 or other phosphotyrosine binding domains. The most frequently identified binding partner for catalytically active Syk identified in a yeast two-hybrid screen was the p85 regulatory subunit of phosphoinositide 3-kinase. The C-terminal SH2 domain of p85 was sufficient for mediating an interaction with tyrosine-phosphorylated Syk. Interestingly, this domain interacted with Syk at phosphotyrosine 317, a site phosphorylated in trans by the Src family kinase, Lyn, and identified previously as a binding site for c-Cbl. This site interacted preferentially with the p85 C-terminal SH2 domain compared with the c-Cbl tyrosine kinase binding domain. Molecular modeling studies showed a good fit between the p85 SH2 domain and a peptide containing phosphotyrosine 317. Tyr-317 was found to be essential for Syk to support phagocytosis mediated by FcgammaRIIA receptors expressed in a heterologous system. These studies establish a new type of p85 binding site that can exist on proteins that serve as substrates for Src family kinases and provide a molecular explanation for observations on direct interactions between Syk and phosphoinositide 3-kinase.