On the spatial distribution of citrus tristeza virus disease

The spatial spread of citrus tristeza virus (CTV) disease was studied using data from two infected groves. Statistical analysis indicated a spatial grouping of infected trees. A gamma distribution was fitted to the empirical distribution of the distances between nearest infected neighbors. The findings suggest that, after locating a newly infected tree, additional inspections to detect CTV should be carried out mainly on trees within 14 m of that tree.     

The global impact of scaling up HIV/AIDS prevention programs in low- and middle-income countries

A strong, global commitment to expanded prevention programs targeted at sexual transmission and transmission among injecting drug users, started now, could avert 28 million new HIV infections between 2005 and 2015. This figure is more than half of the new infections that might otherwise occur during that period in 125 low- and middle-income countries. Although preventing these new infections would require investing about U.S.$122 billion over this period, it would reduce future needs for treatment and care. Our analysis suggests that it will cost about U.S.$3900 to prevent each new infection, but that this will produce a savings of U.S.$4700 in forgone treatment and care costs. Thus, greater spending on prevention now would not only prevent more than half the new infections that would occur from 2005 to 2015 but would actually produce a net financial saving as future costs for treatment and care are averted.     

Accidental fatal aflatoxicosis due to contaminated commercial diet in 50 dogs

Aflatoxins, produced by Aspergillus spp., are toxic contaminants of stored grain. This study describes 50 dogs presented with foodborne aflatoxicosis. Common clinical signs included lethargy (78%), vomiting (76%), anorexia (74%), icterus (66%), depression (66%), melena (60%), haematuria (36%) and diarrhoea (36%). Common laboratory abnormalities included increased activities of aspartate aminotransferase (86%), alkaline phosphatase (84%) and alanine aminotransferase (79%), hypoantithrombinaemia (86%), prolonged prothrombin (PT, 82%) and activated partial thromboplastin times (aPTT, 80%), hyperbilirubinaemia (73%), hypocholesterolaemia (60%) hypoalbuminemia (47%) and thrombocytopenia (42%). Non-survivors had longer PT and aPTT and lower antithrombin (P<0.001) at presentation compared to survivors (23.8s vs.10.5; 37.9 vs.17.6s and 5% vs. 54%, respectively). Hyperbilirubinaemia (>56.6 μmol/L) and albumin concentration <32.5 g/L at presentation were risk factors for mortality (P<0.0001). Common complications included disseminated intravascular coagulation (58%), hepatic encephalopathy (35%) and acute kidney injury (4%). The mortality rate was 68%, suggesting that dogs with aflatoxicosis have poor prognosis.     

α‐6 Integrin Expression in Bovine Spermatogonial Cells Purified by Discontinuous Percoll Density Gradient

The study of spermatogonial stem cells (SSCs) provides a model to better understand adult stem cell biology. Besides the biomedical potential to perform studies of infertility in many species, SSCs hold a promising application at animal transgenesis. Because stem cells are thought to be associated with basement membranes, expression of α‐6 integrin has been investigated as a marker of type A spermatogonial cells, which are considered SSCs because of their undifferentiated status and self‐renewal ability. In this manner, the aim of this study was to isolate type A SSCs from adult bulls by a two‐step enzymatic procedure followed by a discontinuous Percoll density gradient purification and verify the expression of α‐6 integrin by flow cytometry and real‐time RT‐PCR before and after Percoll purification. Spermatogonial cells were successfully obtained using the two‐step enzymatic digestion. An average of 1 × 10⁵ viable cells per gram of testis was isolated. However, the discontinuous Percoll did not purify isolated cells regarding α‐6 integrin expression. Flow cytometry analysis demonstrated no differences in the α‐6 integrin expression between cell samples before and after Percoll purification (p = 0.5636). The same was observed in the real‐time PCR analysis (p > 0.05). In addition to α‐6 integrin, the expression of GFRa‐1 and PGP9.5, known bovine SSCs markers, was detected in all samples studied. Considering that Percoll can reduce cell viability, it is possible to conclude that Percoll density gradient is not suitable to purify bovine SSC, according to α‐6 integrin expression.     

Hemodynamic effects of sevoflurane in spontaneously breathing cats

Sevoflurane has recently been introduced in feline anesthesia. However, its cardiovascular effects have not, to our knowledge, been reported in this species. Six healthy cats, aged 1.81 ± 0.31 years (mean ± SEM) and weighing 3.47 ± 0.11 kg, were studied. Anesthesia was induced and maintained with sevoflurane in oxygen. Body temperature was maintained between 38.5 and 39.55 °C. After instrumentation, end‐tidal sevoflurane concentration was randomly set at 1.25, 1.5, and 1.75 times the individual minimum alveolar concentration (MAC), determined in a previous study, according to a Latin Square Design. Thirty minutes of stabilization was allowed after each change of concentration. ECG and heart rate, systemic and pulmonary arterial pressures, central venous pressure (CVP), and core body temperature were continuously monitored and recorded. Inspired and end‐tidal oxygen, carbon dioxide, and sevoflurane concentrations were measured using a Raman spectrometer, calibrated every 80 minutes with three calibration gases of known sevoflurane concentration (1, 2, and 5%). Moreover, at selected times, pulmonary artery occlusion pressure and cardiac output (thermodilution) were measured, and arterial and mixed venous blood samples were collected for pH and blood gas analysis, hemoglobin concentration, hemoglobin oxygen saturation, packed cell volume (PCV) and total protein determination, and lactate concentration measurement. Cardiac index (CI), stroke index (SI), systemic and pulmonary vascular resistance indices, rate‐pressure product, left and right ventricular stroke work indices (LVSWI and RVSWI, respectively), arterial and mixed venous oxygen contents, oxygen delivery, oxygen consumption, and oxygen utilization ratio were calculated. Data were analyzed by a Repeated Measure Latin Square Design followed by a Tukey's test for 2 × 2 comparisons. Arterial pH significantly decreased from 7.40 ± 0.05 to 7.29 ± 0.07 with the administration of increasing concentrations of sevoflurane. Similarly, LVSWI decreased from 3.72 ± 0.60 to 2.60 ± 0.46 g m^?2. Mean arterial pressure, PaO₂, mixed venous pH, CI, SI, and oxygen delivery tended to decrease dose‐dependently, whereas CVP, PaCO₂, Pv CO₂, PCV, and arterial and mixed venous hemoglobin concentrations tended to increase dose‐dependently with the administration of sevoflurane. However, these trends did not reach statistical significance, possibly because of the limited number of animals studied. Sevoflurane seemed to induce dose‐dependent cardiovascular depression in cats.