Haemoprotozoa in wild short-beaked echidnas (Tachyglossus aculeatus).

The occurrence and clinical significance of the protozoal parasite reported as Hepatozoon tachyglossi in wild short-beaked echidnas (Tachyglossis aculeatus) have long been uncertain, as has its potential as a prognostic indicator. This retrospective survey of free-ranging short-beaked echidnas admitted to a wildlife hospital used morphological evidence to identify a H. tachyglossi prevalence of 56%, with parasitaemias affecting 0%-36% of monocytes. There was no statistical association between H. tachyglossi intensity and clinical status (P-value = 0.12; 95% confidence interval = 0.1 to 1.3), nor between the presence of H. tachyglossi and age, reason for admission, outcome, season or location. Piroplasms, presumed to be Theileria tachyglossi, were concurrently identified in the erythrocytes of 88% of short-beaked echidnas with no association between age, outcome, season or location, but a statistical association with the location where the animal was found (either on a road, airport runway, exposed urban area, or entangled). Given the current results, intracellular parasitism due to H. tachyglossi may be considered as an incidental finding on haematologic examination of short-beaked echidnas and is likely not an effective prognostic indicator. Further research using molecular tools is required to resolve the uncertain identity of H. tachyglossi which has been based on morphologic characteristics alone.

Tick paralysis in Australian birds caused by Ixodes holocyclus.

Tick paralysis is an uncommon cause of neuromuscular paralysis affecting 0.12% of wild birds presented to Currumbin Wildlife Sanctuary, Queensland, with a strong seasonal predilection towards spring and summer. Clinical signs and progression of paralysis showed similarities to companion animals and were consistent across 20 species. Tick location, number of engorged ticks and number of clinical signs did not affect the outcome; however, all mortalities occurred within 4 days of admission. Treatment with canine-derived tick antiserum resulted in clinical improvement within 24 h and a recovery rate of 73%. Average time to resolution of clinical signs was 4.3 days, with juvenile birds recovering more quickly than adults. The treatment and release of wild birds affected by tick paralysis are both achievable and rewarding, further research is required to establish treatment guidelines in birds.

Genetic analysis of porcine circovirus type 2 (PCV2) in Queensland, Australia.

OBJECTIVE: To determine the current porcine circovirus type 2 (PCV2) genotypes circulating in pigs in Queensland (QLD). METHODS: The PCV2 infection status of pigs was determined by real-time PCR testing of 210 lymph nodes and 30 serum samples derived from 45 QLD farms. PCV2-positive samples from 22 pigs from 15 farms were subjected to conventional polymerase chain reaction (PCR) and sequencing of the full PCV2 genome. Phylogenetic analysis of 17 of these sequences in relation to published PCV2 sequences was then performed, and the genotypes were compared. RESULTS: PCV2 DNA was detected in 95 lymph nodes and 15 serum samples. Phylogenetic analysis of 17 PCV2 sequences demonstrated that seven belonged to genotype PCV2b, two to PCV2d, one to PCV2f and seven to an "intermediate group" that clustered with PCV2d on the full genome analysis. CONCLUSION: This work confirms earlier studies reporting the presence of PCV2b in Australia. It is the first study to report that PCV2d and PCV2f are also present in this country. PCV2d is currently a fast-spreading genotype globally, with reported high virulence. The potential implications of these findings with respect to pathogenicity and vaccine efficacy require further investigation.

Molecular and morphological description of Haemoproteus (Parahaemoproteus) bukaka (species nova), a haemosporidian associated with the strictly Australo-Papuan host subfamily Cracticinae.

Linking morphological studies with molecular phylogeny is important to understanding cryptic speciation and the evolution of host-parasite relationships. Haemosporidian parasites of the Australo-Papuan bird family Artamidae are relatively unstudied. Only one parasite species from the subfamily Cracticinae has been described, and this was based solely on morphological description. This is despite many Cracticinae species being easily observed and abundant over large ranges and in close proximity to human populations. We used morphological and molecular methods to describe a new Haemoproteus species (H. bukaka sp. nov.) from an endemic Butcherbird host (Cracticus louisiadensis) in a relatively unstudied insular area of high avian endemism (Papua New Guinea's Louisiade Archipelago). Phylogenetic reconstructions using parasite cyt-b gene sequences placed the proposed Haemoproteus bukaka sp. nov. close to other host-specialist Haemoproteus species that infect meliphagid honeyeater hosts in the region, e.g. H. ptilotis. Distinct morphological characters of this haemosporidian include macrogametocytes with characteristic large vacuoles opposing a subterminal nucleus on the host cell envelope. Among 27 sampled individuals, prevalence of H. bukaka sp.nov. was high (74 % infection rate) but strongly variable across four islands in the archipelago (ranging from 0 to 100 % prevalence). Parasitaemia levels were low across all infected individuals (0.1-0.6 %). We suspect host density may play a role in maintaining high prevalence given the close proximity and similar physical environments across islands. The findings are discussed in the context of the host genus Cracticus and theory relating to parasite-host evolution and its conservation implications in Papua New Guinea.

Influence of sorbitol on protein crowding in solution and freeze-concentrated phases.

Small-angle neutron scattering was employed to study protein crowding under freezing conditions that mimic those used in pharmaceutical processing. The results demonstrate that, although there is an increase in heterogeneity as the temperature is reduced, sorbitol reduces protein crowding in both solution and freeze-concentrated phases, thus protecting the protein from forming oligomers or irreversible aggregates.

Can NCAST and HOME Assessment Scales be used with Hmong refugees?

This descriptive study of a convenience sample of 32 recently settled, preliterate Hmong families tested the applicability of the NCAST and HOME assessment tools in the Hmong refugee population. The sample means on the Nursing Child Assessment Feeding Scale (NCAFS), Nursing Child Assessment Teaching Scale (NCATS), and the Home Observation for Measurement of the Environment (HOME) were compared to a randomly selected sample of white (n = 60), African American (n = 60), and Hispanic (n = 60) families from the University of Washington NCAST (Nursing Child Assessment Satellite Training) normative data bank. The NCAFS and NCATS Hmong total means were not significantly different when compared to the combined normative sample total means. However, when the ethnic groups were compared using ANCOVA with ethnicity and education as covariates, the parent, child, and scale total means were found to be significantly different (p < .05). Hmong HOME total means were significantly lower when compared to the combined normative sample (p < .05) and with separate ethnic group comparisons (p < .05). Although lower for this population lacking formal education, scores were not significantly different when compared to the combined normative sample means. Findings suggest that the NCAST tools should be used with respect for the impact of ethnicity and education on total scores. Findings do not support the use of the HOME scale with this population except as a teaching guide.

Mother-child interaction among the Alaskan Eskimos.

This is an exploration of the world of the Yup'ik Eskimos, who live on the Bering seacoast in rural Alaska. The Eskimos have an ancient culture that has survived the harshest of environments. Although geographically isolated, the Eskimos have become increasingly acculturated to the Western culture. The authors studied maternal-child interaction and quality of the home environment in two remote villages and report their experiences, the Yup'ik Eskimo culture, research findings, and implications for nursing practice.

Using NCAST and the HOME with a minority population: the Alaska Eskimos.

PURPOSE: To test applicability of the NCAST and HOME assessment tools in the Eskimo population. METHOD: A cross-sectional descriptive study of Alaskan native families from two villages used the NCAST and HOME child assessment tools. Comparisons using t-test were made to normative data. ANCOVA was used to test effects of demographic differences. RESULTS: Several significant differences were found on subscales of the NCAFS, NCATS, and HOME, although the total scores of the NCAFS and the NCATS were not significantly different. Caregiver education and ethnicity were significant covariates. CONCLUSIONS: NCAFS and NCATS appears to have sufficient breadth to allow for cultural differences. The HOME scale items measure some aspects of the environment that appear to be culture specific.

Reducing exposures during the pouring operations of a brass foundry.

The focus of this exposure assessment and control technology study was a brass foundry and the lead exposures of workers involved in the transportation and pouring of metal. Controls in place at the foundry included ventilation systems at the furnace and along the continuous and stationary pouring lines. Real-time measurements were made to determine which tasks were the primary exposure sources, and a hand-held aerosol monitor was used to measure real-time aerosol exposures (as a surrogate for lead) in the workers' breathing zones. Data were collected over two 30-min sampling periods while worker activities were monitored using a video camera. Analysis of the data showed that the greatest aerosol exposures occurred during the transportation of an unventilated, full ladle, resulting in an average concentration of at least twice that of the other tasks. The study concluded that the addition of exhaust ventilation such as a moveable hood and duct system during the ladle transport and pouring tasks, and the implementation of a side draft hood at the pigging area, could result in a reduction of worker exposure to aerosols during the continuous pouring operation by up to 40%. The controls and techniques suggested in this study could be applied to pouring operations throughout the industry to reduce worker exposure to metal fumes.

Silica exposure in hand grinding steel castings.

Exposure to silica dust was studied in the grinding of castings in a steel foundry that used conventional personal sampling methods and new real-time sampling techniques developed for the identification of high-exposure tasks and tools. Approximately one-third of the personal samples exceeded the National Institute for Occupational Safety and Health recommended exposure limit for crystalline silica, a fraction similar to that identified in other studies of casting cleaning. Of five tools used to clean the castings, the tools with the largest wheels, a 6-in. grinder and a 4-in. cutoff wheel, were shown to be the major sources of dust exposure. Existing dust control consisted of the use of downdraft grinding benches. The size of the casting precluded working at a distance close enough to the grates of the downdraft benches for efficient capture of the grinding dust. In addition, measurements of air recirculated from the downdraft benches indicated that less than one-half of the respirable particles were removed from the contaminated airstream. Previous studies have shown that silica exposures in the cleaning of castings can be reduced or eliminated through the use of mold coatings, which minimize sand burn-in on the casting surface; by application of high-velocity, low-volume exhaust hoods; and by the use of a nonsilica molding aggregate such as olivine. This study concluded that all these methods would be appropriate control options.

Preservation of the ischemic canine myocardium: a comparison of hypothermia, lidoflazine, and ketanserin.

The purpose of this study was to determine whether ketanserin protects the globally ischemic canine heart and whether such protection, if present, is independent of that provided by hypothermia or calcium channel blockade with lidoflazine. Forty mongrel dogs, anesthetized with halothane, were divided into eight groups of five and subjected to one hour of global myocardial ischemia during hypothermic (30 degrees C; groups 1 to 4) or normothermic (37 degrees C; groups 5 to 8) cardiopulmonary bypass (CPB). Dogs in groups 1 and 5 served as controls with respect to prebypass myocardial protective therapy, and received only placebo (a normal saline bolus) prior to CPB. Before bypass, dogs in groups 2 and 6 received lidoflazine, 1.25 mg/kg intravenously (IV); those in groups 3 and 7 received ketanserin, 5 mg IV bolus, followed by a continuous infusion at 33 microg/min during bypass. Animals in groups 4 and 8 were given both lidoflazine and ketanserin according to the dosing schedules above. No type of pharmacologic or mechanical cardiovascular support was provided after termination of CPB. Postbypass hemodynamic performance and survival of the unsupported animal were assumed to reflect the degree of myocardial protection during CPB. One minute after bypass, mean arterial pressure and cardiac output were decreased in all groups. Cardiac output was lower in groups 5 to 8 (normothermic CPB) than in groups 1 to 4 (hypothermic CPB). After CPB, left ventricular filling pressures were elevated in all groups kept normothermic and in group 3 (hypothermic CPB plus ketanserin). By 15 minutes after CPB, there were no survivors in groups 5, 7, and 8. Sixty percent of animals in group 6 (normothermic CPB plus lidoflazine) survived to the end of the study. Relative odds of survival were increased 110-fold by hypothermia and sevenfold by lidoflazine. Conversely, treatment with ketanserin was associated with an increased likelihood of nonsurvival. It is concluded that, at the doses studied, ketanserin does not protect the canine myocardium against ischemic injury and may exert a detrimental effect when combined with calcium channel blockade in this setting.

Antagonism of postoperative opioid-induced respiratory depression: nalbuphine versus naloxone.

The authors compared naloxone and nalbuphine as antagonists of opioid-induced respiratory depression to determine the relative efficacies and safety of the two agents. In a double-blind, randomized fashion, 90 anesthetized patients received a mean dose of 25 micrograms/kg fentanyl during surgery. Inadequate spontaneous respirations at the end of anesthesia were treated with either naloxone 0.08 mg or nalbuphine 2.5 mg IV every 2 min while heart rate (HR), systolic and diastolic blood pressures (SBP, DBP), respiratory rate (RR), and tidal volume (TV) were measured at 2-min intervals. Arterial blood samples for analysis of PaCO2, PaO2, and pH were drawn when spontaneous ventilation resumed, and 30 and 60 min later. Narcotic antagonism and respiration were deemed adequate when TV was greater than or equal to 4 ml/kg and RR greater than or equal to 8 breaths/min. Heart rate, SBP, DBP, TV and RR were recorded, as were the occurrence of renarcotization (RR less than 8) and analgesic requirements every 5 min during the recovery room stay. Sixty of 90 patients required narcotic antagonism at the end of surgery. No patient required more than three doses (0.24 mg) of naloxone or four doses (10 mg) of nalbuphine. Both antagonists produced similar and moderate increases in SBP and HR while restoring adequate spontaneous ventilation. There were no significant differences in TV, RR, or arterial blood gases (ABGS) between the two groups after narcotic reversal.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of sufentanil-N2O and fentanyl-N2O in patients without cardiac disease undergoing general surgery.

Sufentanil (mean total dose 2 micrograms/kg) was compared with fentanyl (mean total dose 15 micrograms/kg) as a supplement to 60% N2O anesthesia in 30 adult patients undergoing general surgical procedures. Comparisons were made with respect to stability of hemodynamic variables (heart rate and systolic and diastolic blood pressure), changes in stress hormones (cortisol, antidiuretic hormone, epinephrine, norepinephrine, and dopamine), recovery of alertness and orientation, time to extubation, postoperative analgesia, and measures of respiratory depression (resting end-tidal carbon dioxide tension [PETCO2], CO2 response curve for minute ventilation [delta VE/delta PETCO2]). Hemodynamic variables remained stable and similar in both groups throughout the study. Plasma hormone levels remained similar to baseline in both groups until 1 h postoperatively when epinephrine levels were significantly elevated in both groups (P less than 0.05). Recovery times, including time to extubation, were similar in both groups. Patients given sufentanil had less pain 30 min postoperatively than those given fentanyl, although at 60 min postoperatively pain levels were similar in both groups. Small but significant elevations in resting PETCO2 were seen in both groups postoperatively (P less than 0.05), but postoperative delta VE/delta PETCO2 responses were significantly depressed only in patients receiving fentanyl (P less than 0.05). The results of this study demonstrate that sufentanil-N2O anesthesia is as effective as fentanyl-N2O in attenuating the hemodynamic and hormonal responses to the stress of general surgery. Because continuous intraoperative PETCO2 monitoring was not employed in this study, intraoperative hypocapnea cannot be strictly excluded as a possible influence on the postoperative measures of ventilatory drive.(ABSTRACT TRUNCATED AT 250 WORDS)

Failure of nalbuphine to antagonize morphine: a double-blind comparison with naloxone.

The authors studied the respiratory and analgesic effects of nalbuphine (0.21 mg/kg, intravenous), naloxone (0.014 mg/kg, intravenous), and placebo (normal saline) when given after morphine (0.21 mg/kg, intravenous) in a double-blind, randomized fashion. Resting end-tidal CO2 (PETCO2), ventilatory and occlusion pressure responses to CO2 rebreathing, and pain threshold were measured in 12 healthy adult volunteers before, 5 min, and 30 min after morphine. Nalbuphine, naloxone, or saline were administered 55 min after morphine, and the above measurements were repeated 5 min later (60 min after morphine) as well as 90, 120, 180, and 240 min after morphine. Whereas naloxone reversed respiratory depression as measured by all three respiratory parameters, nalbuphine either further depressed (resting PETCO2) or did not affect (ventilatory and occlusion pressure responses to CO2 rebreathing) respiratory drive. Morphine produced a significant elevation of the pain threshold. Significant decreases in the pain threshold were seen only after naloxone. Saline and nalbuphine did not significantly alter the pain threshold. The data indicate that nalbuphine may not reliably antagonize moderate doses of morphine.

Pulmonary arterial catheterization before anesthesia in patients undergoing cardiac surgery. Placement of the pulmonary arterial catheter before anesthesia for cardiac surgery: safe, intelligent, and appropriate use of invasive hemodynamic monitoring.

Should one catheterize the pulmonary artery (PA) for cardiac surgery before or after induction of anesthesia? Issues of central importance to this question include (1) the patient's preexisting hemodynamic abnormalities, (2) cardiovascular effects of anesthetic induction drugs, and (3) hemodynamic stress caused by laryngoscopy, endotracheal intubation, and PA catheter insertion. Some clinicians use the PA catheter immediately before anesthetic induction to detect and correct acute abnormalities in preload and ventricular function. This approach has been described as being partially responsible for decreased morbidity and mortality in patients with cardiovascular disease. Hemodynamic instability during induction has been reported with many of the common anesthetic induction agents, especially in patients with poor ventricular function. Since blood pressure is the product of cardiac output and systemic vascular resistance, accurate interpretation and treatment of hypotension are possible only when these variables are provided by vigorous use of the PA catheter. Early detection of myocardial ischemia is possible with examination of acute changes in the pulmonary capillary wedge pressure tracing. However, the lack of such information can restrict even the best anesthetist. Insertion of the PA catheter in the awake patient can be accomplished effectively and with minimal risk, so long as good patient rapport, adequate premedication, and continuation of antianginal medication until the time of surgery are assured. Preinduction placement of the PA catheter provides valuable, objective information for the cardiac anesthesiologist without incurring significant risk to the patient.