Biotype Q of<Emphasis Type="Italic">Bemisia tabaci</Emphasis> identified in Israel

The biotype status of samples of the whiteflyBemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) collected from several field and greenhouse sites in Israel during 1999–2000 was determined by polyacrylamide gel electrophoresis (PAGE) for general esterases, and by RAPD-PCR using primers of arbitrary sequence. Results of this survey provide the first published evidence for the occurrence of theB. tabaci Q biotype, alongside the more widely distributed B biotype. Based on the collected samples, it appears that both the B and Q biotypes are present in Israel, and that field populations consist of a mixture of the two biotypes. A possible link betweenB. tabaci biotypes and insecticide resistance is discussed. Contribution no. 508/02 from the Inst. of Plant Protection, ARO, The Volcani Center, Bet Dagan, Israel. http://www.phytoparasitica.org posting Dec. 5, 2002.     

Performance of serologic tests used to detect heartworm infection in cats

OBJECTIVE: To compare heartworm serum antibody (Ab) and antigen (Ag) test results, using commercial laboratories and in-house heartworm test kits, with necropsy findings in a population of shelter cats. DESIGN: Prospective study. ANIMALS: 330 cats at an animal shelter. PROCEDURE: Between March and June 1998, 30 ml of blood was collected from the cranial and caudal venae cavae of 330 cats that were euthanatized at a local animal shelter. Results of heartworm Ab and Ag serologic tests for heartworm infection were compared with necropsy findings in this population of cats, using commercial laboratories and in-house test kits to measure serum Ab and Ag concentrations. RESULTS: On necropsy, adult Dirofilaria immitis were found in 19 of 330 (5.8%) cats. Combining results from serum Ab and Ag tests achieved higher sensitivities than using serum Ab and Ag test results alone (i.e., maximum sensitivities of 100% vs 89.5%, respectively, whereas use of serum Ag and Ab test results alone achieved higher specificities compared with the use of a combination of serum Ab and Ag results (i.e., maximum specificities of 99.4% vs 92.9%, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of our findings, if a cat has clinical signs that suggest heartworm disease despite a negative heartworm serum Ab test result, an alternative heartworm Ab test, a heartworm Ag test, thoracic radiography, or two-dimensional echocardiography should be performed.     

Rh factor: prevention of isoimmunization and clinical trial on mothers

The results on the use of gammaG-immunoglobulin to Rh factor for the prevention of active immunization of Rh-negative mothers at risk appear most promising. One hundred and seven mothers in the clinical trial have been followed for periods of about 6 months to 1(1/2)12 years after delivery. Of these, 48 were treated mothers who received 5 ml gammaG-immunoglobulin to Rh, and 59 were untreated mothers. Of the 48 treated mothers none are actively immunized; seven of the 59 control mothers have become actively immunized to Rh.     

INTRACRANIAL SUBARACHNOID HEMORRHAGE FOLLOWING LUMBAR MYELOGRAPHY IN TWO DOGS

Intracranial subarachnoid hemorrhage is a rare but serious complication of lumbar puncture in humans. Possible sequelae include increased intracranial pressure, cerebral vasospasm, or mass effect, which can result in dysfunction or brain herniation. We describe two dogs that developed intracranial subarachnoid hemorrhage following lumbar myelography. In both dogs, myelography was performed by lumbar injection of iohexol (Omnipaque). Both the dogs underwent uneventful ventral decompressive surgery for disk herniation; however, the dogs failed to recover consciousness or spontaneous respiration following anesthesia. Neurologic assessment in both dogs postoperatively suggested loss of brain stem function, and the dogs were euthanized. There was diffuse subarachnoid hemorrhage and leptomeningeal hemorrhage throughout the entire length of the spinal cord, brain stem, and ventrum of brain. No evidence of infectious or inflammatory etiology was identified. The diagnosis for cause of brain death was acute subarachnoid hemorrhage. Our findings suggest that fatal subarachnoid hemorrhage is a potential complication of lumbar myelography in dogs. The cause of subarachnoid hemorrhage is not known, but may be due to traumatic lumbar tap or idiosyncratic response to contrast medium. Subsequent brain death may be a result of mass effect and increased intracranial pressure, cerebral vasospasm, or interaction between subarachnoid hemorrhage and contrast medium.     

Hematologic effects of subcutaneous administration of recombinant human granulocyte colony-stimulating factor (filgrastim) in healthy alpacas

OBJECTIVE: To determine the effects of SC administration of filgrastim on cell counts in venous blood and bone marrow of healthy adult alpacas. ANIMALS: 10 healthy alpacas. PROCEDURES: Alpacas were randomly assigned to receive treatment with filgrastim (5 microg/kg, SC; n=5) or an equivalent volume of physiologic saline (0.9% NaCl) solution (5) once a day for 3 days. Blood samples were obtained via jugular venipuncture 1 day prior to treatment and once a day for 5 days commencing 24 hours after the first dose was administered. Complete blood counts were performed for each blood sample. Bone marrow aspirates were obtained from the sternum of each alpaca 48 hours before the first treatment was administered and 72 hours after the third treatment was administered. Myeloid-to-erythroid cell (M:E) ratio was determined via cytologic evaluation of bone marrow aspirates. RESULTS: In filgrastim-treated alpacas, substantial increases in counts of WBCs and neutrophils were detected within 24 hours after the first dose was administered. Band cell count and percentage significantly increased 24 hours after the second dose. Counts of WBCs, neutrophils, and band cells remained high 48 hours after the third dose. Red blood cell counts and PCV were unaffected. The M:E ratio also increased significantly after treatment with filgrastim. CONCLUSIONS AND CLINICAL RELEVANCE: Filgrastim induced rapid and substantial increases in numbers of circulating neutrophils and M:E ratios of bone marrow in healthy alpacas. Therefore, filgrastim may be useful in the treatment of camelids with impaired bone marrow function.     

Interannual variability in growth of larval and juvenile walleye pollock Theragra chalcogramma in the western Gulf of Alaska, 1983–91

Interannual variability in growth of larval walleye pollock Theragra chalcogramma was examined from 1983 to 1991 and of juveniles from 1985 to 1990. ANCOVA was used to assess differences in population growth rates, and an alternate method was developed to examine variations between annual length-at-age data and average 'expected' values over different age groupings. For larvae, the years 1986, 1987, 1989 and 1990 had higher than average length-at-age, and 1988 and 1991 had lower than average values. Relationships between growth and SST and larval density were not clear. A tentative relationship between copepod nauplii abundance and larval length-at-age was noted. The consequence of larval growth to larval mortality, late larval abundance or recruitment was not clear. We conclude that larval mortality rates are highly variable and tend to mask effects of moderate variability in growth on later abundance. For juveniles, 1987 had significantly lower than average length-at-age and 1988 had higher than average values. Although there are few years of data, they tend to support the importance of juvenile growth in the recruitment process. Conditions for the large 1988 year class are documented and discussed, including warm SST, calm winds, relatively low larval growth rates, low abundances of potential predators on larvae, low larval mortality rates, and high juvenile growth rates.     

Observed patches of walleye pollock eggs and larvae in Shelikof Strait, Alaska: their characteristics, formation and persistence

Using observations from 38 ichthyoplankton surveys conducted near Shelikof Strait, Alaska between 1979 and 1992, we characterized the horizontal distribution and spatial patchiness of the early life stages of walleye pollock ( Theragra chalcogtamma ). Lloyd's index of patchiness ranged from 3.9-6.1 for eggs and 3.9–16.2 for larvae. This index was size (age) dependent: low for eggs, high for newly hatched larvae, then decreasing through late larval stage. By the early juvenile stage, patchiness increased as pollock began to school. The percentage of larvae in a patch (defined as the percentage of larvae present at stations where larval counts exceeded the mean by one standard deviation during the given survey) varied greatly (26–92%). Larval distributions were used to deduce physical mechanisms responsible for patches. Three categories of patches were identified: those created by interaction of larvae with time-dependent currents, those in the vicinity of Sutwik Island, and those associated with eddies. Simulation experiments were utilized to examine processes influencing patch formation and the role of larval swimming. Between 5 and 6 weeks after hatching, larvae have swimming abilities that enable them to maintain a patch already created by physical mechanisms.