Anticoagulant rodenticides in urban bobcats: exposure, risk factors and potential effects based on a 16-year study.

Anticoagulant rodenticides (ARs) are increasingly recognized as a threat to nontarget wildlife. High exposure to ARs has been documented globally in nontarget predatory species and linked to the high prevalence of an ectoparasitic disease, notoedric mange. In southern California, mange associated with AR exposure has been the proximate cause of a bobcat (Lynx rufus) population decline. We measured AR exposure in bobcats from two areas in southern California, examining seasonal, demographic and spatial risk factors across landscapes including natural and urbanized areas. The long-term study included bobcats sampled over a 16-year period (1997-2012) and a wide geographic area. We sampled blood (N = 206) and liver (N = 172) to examine exposure ante- and post-mortem. We detected high exposure prevalence (89 %, liver; 39 %, blood) and for individuals with paired liver and blood data (N = 64), 92 % were exposed. Moreover, the animals with the most complete sampling were exposed most frequently to three or more compounds. Toxicant exposure was associated with commercial, residential, and agricultural development. Bobcats of both sexes and age classes were found to be at high risk of exposure, and we documented fetal transfer of multiple ARs. We found a strong association between certain levels of exposure (ppm), and between multiple AR exposure events, and notoedric mange. AR exposure was prevalent throughout both regions sampled and throughout the 16-year time period in the long-term study. ARs pose a substantial threat to bobcats, and likely other mammalian and avian predators, living at the urban-wildland interface.

Neurologic outcome at school entry for newborns treated with extracorporeal membrane oxygenation for noncardiac indications.

The neurologic outcomes at school age in children who underwent neonatal extracorporeal membrane oxygenation for noncardiac indications in a single institution surviving till the age of 5 years was determined by standardized neurologic assessment. Of 42 newborns undergoing extracorporeal membrane oxygenation, 24 underwent neurologic assessment by a single neurologist at 5 years of age. In all, 12 (50%) had a normal neurologic outcome. Lower gestational age and birth weight was found to be associated with an abnormal outcome as was septic shock as an indication for extracorporeal membrane oxygenation initiation. The number of peri-extracorporeal membrane oxygenation complications experienced by a child was associated with later epilepsy. Although invasive and implemented in critically ill infants, half of newborns undergoing extracorporeal membrane oxygenation will have a normal neurologic outcome at school age. Preexisting factors, rather than factors related to the extracorporeal membrane oxygenation itself, appear to be greater determinants of later neurologic outcomes.

Frequent transmission of immunodeficiency viruses among bobcats and pumas.

With the exception of human immunodeficiency virus (HIV), which emerged in humans after cross-species transmissions of simian immunodeficiency viruses from nonhuman primates, immunodeficiency viruses of the family Lentiviridae represent species-specific viruses that rarely cross species barriers to infect new hosts. Among the Felidae, numerous immunodeficiency-like lentiviruses have been documented, but only a few cross-species transmissions have been recorded, and these have not been perpetuated in the recipient species. Lentivirus seroprevalence was determined for 79 bobcats (Lynx rufus) and 31 pumas (Puma concolor) from well-defined populations in Southern California. Partial genomic sequences were subsequently obtained from 18 and 12 seropositive bobcats and pumas, respectively. Genotypes were analyzed for phylogenic relatedness and genotypic composition among the study set and archived feline lentivirus sequences. This investigation of feline immunodeficiency virus infection in bobcats and pumas of Southern California provides evidence that cross-species infection has occurred frequently among these animals. The data suggest that transmission has occurred in multiple locations and are most consistent with the spread of the virus from bobcats to pumas. Although the ultimate causes remain unknown, these transmission events may occur as a result of puma predation on bobcats, a situation similar to that which fostered transmission of HIV to humans, and likely represent the emergence of a lentivirus with relaxed barriers to cross-species transmission. This unusual observation provides a valuable opportunity to evaluate the ecological, behavioral, and molecular conditions that favor repeated transmissions and persistence of lentivirus between species.

Long-term pulmonary sequelae of severe bronchopulmonary dysplasia.

OBJECTIVE: To evaluate the long-term pulmonary sequelae of survivors of bronchopulmonary dysplasia (BPD) of sufficient severity to have required supplemental oxygen for at least 1 month after term. STUDY DESIGN: Fifteen patients with a mean age of 1.1 years were matched to preterm infants of similar gestational age and age at time of study. Pulmonary function testing included spirometry, plethysmographic lung volumes, carbon monoxide diffusion capacity, and in 9 of 15 subjects with BPD, measurement of lung static elastic recoil pressures. RESULTS: The subjects with BPD had a mean expiratory volume in 1 second (FEV1) of 64% +/- 21% predicted (4 had an FEV1 < 50% predicted) compared with 85% +/- 11% (P < .01) for the preterm children in the control group. Subjects with BPD had a significant degree of gas trapping with a residual volume to total lung capacity ratio of 37% +/- 13% compared with 25% +/- 4% for the control group (P < .01). An inverse relationship was seen between the FEV1 and the time on supplemental oxygen (r = -0.84, P < .0001), with 3 of the 4 children whose FEV1 was < 50% requiring oxygen for more than 900 days. Those with the greatest degree of airflow limitation and gas trapping had the greatest abnormalities in both shape and position of the pressure volume curves of the lung. CONCLUSION: Severe BPD may result in moderate to severe long-term abnormalities in pulmonary function tests.

Bartonella henselae antibody prevalence in free-ranging and captive wild felids from California.

In order to determine the importance of wild felids in the epidemiology of Bartonella spp. infection, 136 Nobuto strips or serum samples from free-ranging mountain lions (Felis concolor) and bobcats (Felis rufus) captured in California (USA) between 1985 and 1996 were tested for B. henselae antibodies (titer > or = 1:64) using an immunofluorescence test. Similarly, 124 serum samples from 114 captive wild cats representing 26 species or subspecies collected between 1991 and 1995 were retrieved from the serum banks of four California zoological parks. Fifty-three percent (33/62) of the bobcats, 35% (26/74) of the mountain lions, and 30% (34/114) of the captive wild felids (genera Acinonyx, Panthera and Felis) had B. henselae antibodies. In captive wild felids, prevalence varied widely among the species, but seropositivity was more likely to occur in the genus Felis than in the genus Acinonyx or Panthera. Prevalence was evenly distributed between sexes, except for free-ranging mountain lions. Antibody prevalence ranged from 25% in 0- to 2-yr-old captive felids to 35% in cats > or = 9-yr-old, but the highest antibody titers were observed in cats < 5-yr-old.

Characterization of human erythrocyte choline transport in chronic renal failure.

BACKGROUND: Membrane transport of choline cations is elevated in renal failure in erythrocytes and cerebral tissue but the origins and clinical importance of this are unknown. METHODS: The membrane transport changes have been characterized using erythrocytes from patients on maintenance haemodialysis (HD), patients on continuous ambulatory peritoneal dialysis (CAPD), and control subjects. Data were obtained from cells depleted of intracellular choline to create zero-trans (ZT) conditions for choline influx. [14C]-choline influx measurements provided a kinetic description of choline flux as the sum of a saturable transport system (defined by Vmax and Km) and an apparent diffusion pathway. Inhibition of choline transport by hemicholinium-3 (HC-3), quinine and N-ethylmaleimide (NEM) has been studied. Actions of three cationic polyamine putative uraemic toxins (putrescine, spermidine, spermine) were tested in control erythrocytes. RESULTS: Mean (SEM) Vmax (ZT) was increased in HD at 45.0 (3.0) mumol/l cells/h and in CAPD at 46.6 (2.5) mumol/l cells/h compared to controls (30.0 (2.0) mumol/l cells/h). Mean Km (ZT) was not significantly altered in HD or CAPD (HD: 6.1 (1.6) microM; CAPD: 5.5 (0.7) microM; control: 5.1 (0.9) microM). The sensitivity of choline transport to the inhibitors tested was not altered in HD. 1.0 mM quinine, 2.0 mM NEM and 1.0 mM HC-3 caused 75-90% inhibition of transport in both HD and controls. For inhibition of ZT influx of 25 microM choline the mean IC50 of quinine was 90 (9) microM in HD and 101 (13) microM in controls (n.s.). The ZT influx of 200 microM choline was not altered by any of the polyamines at concentrations up to 1.0 mM. CONCLUSIONS: Membrane choline transport in CRF remains protein-mediated and exhibits normal substrate and inhibitor affinities; high values of Vmax seem to occur through increased surface expression of an active normal choline transporter. Increases in plasma polyamines cannot explain the choline transport changes in CRF.

Exercise ability in survivors of severe bronchopulmonary dysplasia.

There is limited information concerning the exercise performance of long-term survivors of bronchopulmonary dysplasia (BPD), and much of what is available pertains to those with relatively mild disease. The present study was undertaken to describe exercise responses in patients with a history of severe BPD, defined as those patients with a clinical and radiographic diagnosis of BPD who required supplemental oxygen at least until they were 44 wk postconceptual age and who were discharged home on oxygen. Fifteen children with a history of severe BPD were matched for gestational age with 15 children who had previously had respiratory distress syndrome but who did not develop BPD (Prem). These Prem control children were subsequently compared with 13 healthy control children born at term (Control) who were of similar postnatal age. Participants underwent pulmonary function testing, progressive exercise testing on a cycle ergometer, and a steady-state exercise test with cardiac output determined by CO2-rebreathing. Despite the patients with BPD having a lower FEV1 than those in the Prem group, who had lower values than the Control group (BPD, 64 +/- 21%; Prem, 85 +/- 11%; Control, 95 +/- 8%), the exercise capacity did not differ between the BPD and the Prem and between the Prem and the Control groups (BPD, 84 +/- 15%; Prem, 81 +/- 17%; Control, 91 +/- 12%). However, the BPD patients used a greater percentage of their ventilatory reserve (VEmax/40 FEV1: BPD, 93 +/- 20%; Prem, 67 +/- 12%; Control, 59 +/- 13%). Of the four patients with BPD who had significant oxygen desaturation with exercise, three had the lowest values for FEV1. Cardiac output was appropriate for oxygen consumption in most patients.

Goal directed therapy with dobutamine in a porcine model of septic shock: effects on systemic and renal oxygen transport.

Systemic and renal haemodynamic and functional indices were measured in 15 anaesthetised pigs during systemic sepsis induced by faecal peritonitis. Five animals were assigned to maintenance of cardiac output (CO) at baseline, pre-infection values throughout the study (controls n = 5). In the remaining 10 animals, CO was increased by 25% prior to induction of sepsis and maintained at this level for the duration of the study using volume expansion with intravenous colloid and an infusion of either 20 micrograms/kg/min dobutamine (n = 5) or placebo (n = 5). Hourly measurements were made of CO, left renal blood flow, arterial and renal venous oxygen saturation, urine output, creatinine clearance and arterial partial pressure of oxygen until the animal died or until termination 8 h. Systemic indices of oxygen transport did not reflect the behaviour of the renal vascular bed during the management of sepsis. In the dobutamine group systemic oxygen uptake (VO2) increased from 173 +/- 30 to 277 +/- 73 ml/min (P less than 0.05), however this resulted in a decrease in renal DO2 (20 +/- 9 to 10 +/- 2 ml/min P less than 0.05) and there was no equivalent rise in renal VO2 (3.3 +/- 1.6 to 3.2 +/- 1.5 ml/min). There was however no significant difference in the effect on renal function of the three management protocols. Agents used to increase cardiac output during systemic sepsis may result in significantly different effects on the renal vascular bed which are not revealed by the measurement of systemic indices alone.

The long-term pulmonary sequelae of prematurity: the role of familial airway hyperreactivity and the respiratory distress syndrome.

Respiratory distress syndrome of the newborn, prematurity, and familial airway hyperreactivity may contribute to long-term pulmonary sequelae. We assessed the role of each by testing pulmonary function and airway reactivity in 11 prematurely born children who survived the respiratory distress syndrome and in 11 prematurely born children who had no neonatal respiratory disease, each of whom was paired with a sibling born at term. The subjects were between 7 and 12 years of age when studied. Airway reactivity was also assessed in their mothers. The group who had had the respiratory distress syndrome had higher ratios of residual volume to total lung capacity and lower values for forced expiratory volume in one second than did their siblings or normal controls (P less than 0.01). Expiratory flow was decreased in both groups born prematurely (P less than 0.02) and was related to neonatal exposure to oxygen (r = -0.71, P less than 0.02). The incidence of airway hyperreactivity was elevated in all groups, including the mothers. These data suggest that long-term pulmonary sequelae of the respiratory distress syndrome of the newborn are related to the disease, its treatment, or both, and to airway hyperreactivity. In prematurely born children without neonatal lung disease, the sequelae are related to airway hyperreactivity. The possibility of a relation between familial airway hyperreactivity and premature birth is suggested.