PLAY-DOH® AND WATER-SOAKED GAUZE SPONGES AS ALTERNATIVE BOLUS MATERIAL FOR COBALT-60 TELETHERAPY

A study was performed to determine if carefully made boluses of either Play-Doh, or water-soaked cotton gauze sponges differed from the commercial bolus material, Superflab, in producing maximum radiation dose when irradiated with cobalt-60 photons. The radiation doses were measured with thermoluminescent dosimeters calibrated to be accurate for cobalt-60 photon energies at doses less than 10.0 cGy. The resulting radiation doses were similar when using Play-Doh, water-soaked sponges, or Superlab. Doses resulting from Play-Doh boluses more consistently approximated those of Superflab. The results of this study suggest that either Play-Doh or water-soaked cotton gauze sponges can suffice as material for carefully made bolus for cobalt-60 teletherapy.     

Proteolytic enzymes from Trichinella spiralis larvae.

Trichinella spiralis larvae infect their hosts by the penetration of small intestine enterocytes. The exact mechanism of penetration is unknown, but the presence of proteolytic enzymes is suspected. In this study, whole worm extracts and excretory-secretory (ES) components were obtained and their proteolytic enzymes examined. Enzymes from worm extracts were capable of hydrolysing azocoll, a general protease substrate in a wide range of pH (2-8), with maximal activity at pH 5. Trichinella spiralis larval enzymes were sensitive to metalloprotease and serine protease inhibitors. Three proteases were identified in worm extracts at molecular weight (MW) 48, 54 and 62 kDa by incorporating a gelatine substrate into a standard or a modified sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) set-up, in which we used low SDS concentration in gel and electrophoresis buffer (0.01%). Intact larvae incubated in a medium containing azocoll showed azocollytic activity. Subsequent analysis of ES products by modified SDS-PAGE in gels containing gelatine demonstrated the presence of three protease of apparent MW 33, 62 and 230 kDa.     

Effect of photoperiod manipulation on daily rhythms of melatonin and reproductive hormones in caged European sea bass (Dicentrarchus labrax)

There are few studies regarding the daily changes in reproductive hormone profiles in teleosts. The aim of the present research was to investigate the effects of photoperiod manipulation on daily rhythms of melatonin and reproductive hormones (pituitary and plasma LH, testosterone [T] and 11-ketotestosterone [11KT]) in juvenile sea bass, kept in net cages under farming conditions in winter. Our results provide the first evidence for the presence of daily variations in pituitary and plasma LH and plasma T in sea bass. Artificial lights suppressed circulating plasma melatonin levels and significantly affected the daily rhythm of LH storage and release.     

Experimental infection of sheep with bovine leukemia virus: infectivity of blood, nasal and saliva secretions

This study was designed to determine the relative infectivity of lymphocytes and secretions from BLV-infected cattle with and without persistent lymphocytosis (BLV+PL+ and BLV+PL-). Ninety-seven sheep of mixed sex and age were assembled into 21 experimental groups. The recipient sheep were inoculated intravenously with serial dilutions of whole blood, saliva or nasal secretions from BLV+PL+ and BLV+PL- donor cows. Between 200 to 20,000 cells from single and mixed BLV+PL+ or single and mixed BLV+PL- donor cattle were used for inoculation. A very small number of BLV-infected lymphocytes (200 cells) was sufficient to induce BLV infection in sheep inoculated with diluted whole blood from BLV+PL+ cattle. The inoculation of whole blood (containing up to 20,000 lymphocyte cells) from BLV+PL- cattle did not induce BLV infection in recipient sheep. Saliva and nasal secretions also failed to bring about BLV transmission.     

IN VITRO EVALUATION OF CANINE GRANULOCYTES LABELED WITH 99mTC-HEXAMETHYLPROPYLENEAMINE OXIME:

Technetium-99m hexamethylpropyleneamine oxine (^99mTc-HMPAO) and Indium-111 oxine (¹¹¹In-oxine) labeled canine gramulocytes were evaluated in vitro over a six hour period. Labeling efficiency for ^99mTC-HMPAO and ¹¹¹In-oxine labeled granulocytes was 39.6%± 8.0% and 60.6%± 17.6% (mean ± SD) respectively. The mean in vitro elution of the radiolabel ranged from 8.7-14.0% for the ^99mTc-HMPAO grannulocytes and from 6.1-9.0% for the ¹¹¹In-oxine granulocytes. Mean cell viability, for the ^99mTc-HMPAO, ¹¹¹In-oxine and non-radiolabeled control granulocytes ranged from 97.8-99.4%, 96.4-98.5% and 98.2-99.0%, respectively. The phagocytic ability of the ^99mTc-HMPAO, ¹¹¹In-oxine and control granulocytes ranged from 47.5-54.1%, 38.9-56.2% and 46.6-57.8% respectively over the six hour study period. Although labeling efficiency using ¹¹¹In-oxine was significantly (P=0.05) better than ^99mTc-HMPAO, there was no significant difference in label retention of the two radiolabels. There was no significant difference in viability or phagocytic function during the six hour study period. Considering the potential cost advantage and the superior imaging qualities of Technetium-99m relative to Indium-111, ^99mTc-HMPAO appears to be a good alternative to ¹¹¹In-oxine as a granulocyte label.     

Effect of aztreonam upon human polymorphonuclear leukocyte functions.

Aztreonam (SQ 26,776), a new synthetic monobactam with an excellent antibacterial spectrum was analyzed in vitro. In this paper, the effect of aztreonam on the phagocytic process of human neutrophils isolated from fifteen healthy volunteers was studied. Chemotaxis was not modified with aztreonam at any of the doses used (10, 20, 40, 60, 80 and 100 micrograms/ml). On the other hand, this antibiotic at 100 micrograms/ml significantly increases (P less than 0.05) Candida albicans ingestion as well as their digestion by neutrophils at 10 and 100 micrograms/ml.     

Landscape capability models as a tool to predict fine-scale forest bird occupancy and abundance

Context

Species-specific models of landscape capability (LC) can inform landscape conservation design. Landscape capability is “the ability of the landscape to provide the environment […] and the local resources […] needed for survival and reproduction […] in sufficient quantity, quality and accessibility to meet the life history requirements of individuals and local populations.” Landscape capability incorporates species’ life histories, ecologies, and distributions to model habitat for current and future landscapes and climates as a proactive strategy for conservation planning.

Objectives

We tested the ability of a set of LC models to explain variation in point occupancy and abundance for seven bird species representative of spruce-fir, mixed conifer-hardwood, and riparian and wooded wetland macrohabitats.

Methods

We compiled point count data sets used for biological inventory, species monitoring, and field studies across the northeastern United States to create an independent validation data set. Our validation explicitly accounted for underestimation in validation data using joint distance and time removal sampling.

Results

Blackpoll warbler (Setophaga striata), wood thrush (Hylocichla mustelina), and Louisiana (Parkesia motacilla) and northern waterthrush (P. noveboracensis) models were validated as predicting variation in abundance, although this varied from not biologically meaningful (1%) to strongly meaningful (59%). We verified all seven species models [including ovenbird (Seiurus aurocapilla), blackburnian (Setophaga fusca) and cerulean warbler (Setophaga cerulea)], as all were positively related to occupancy data.

Conclusions

LC models represent a useful tool for conservation planning owing to their predictive ability over a regional extent. As improved remote-sensed data become available, LC layers are updated, which will improve predictions.

     

Nutritional planning for Nellore heifers post-weaning to conception at 15 months of age: performance and nutritional,metabolic, and reproductive responses

Tropical Animal Health and Production - The objective of this study was to evaluate the effects of strategic supplementation in the dry period and dry/rainy transition period on the performance and...     

The pharmacokinetics of cytarabine administered at three distinct subcutaneous dosing protocols in dogs with meningoencephalomyelitis of unknown origin

The objective of this study was to evaluate the pharmacokinetics of the standard cytarabine (Ara‐C) protocol (50 mg/m² subcutaneously every 12 hr for 2 days) used for dogs with neuroinflammatory disease and compare it to two more practical protocols (a single 200 mg/m² subcutaneous dose and two 100 mg/m² subcutaneous doses every 12 hr). Four client‐owned dogs previously diagnosed with meningoencephalomyelitis of unknown origin were administered three distinct Ara‐C protocols with a 21‐day washout between each protocol. A complete blood count was performed seven days after each dosing protocol to assess for clinically relevant myelosuppression. No adverse events were observed. Plasma Ara‐C concentrations were measured using a validated liquid chromatography coupled to tandem mass spectrometry assay. The mean maximal concentrations in this study were 4,230, 9,293, and 16,675 ng/ml for a single dose of 50, 100, and 200 mg/m², respectively. There was a linear relationship between dose and drug exposure. Drug exposure was similar regardless of the dosing protocol when the total dose was analyzed, with an area under the concentration versus time curve of 37,026, 38,465, and 32,510 ng × hr/ml for 50, 100, and 200 mg/m², respectively.