Retrospective Study: Cause and clinical characteristics of rib fractures in cats: 33 cases (2000–2009)

Objective – To characterize the clinical features and population differences among cats sustaining traumatic and nontraumatic rib fractures. Design – Retrospective clinical study. Setting – University small animal hospital. Animals – Thirty‐three cats with radiographic evidence of rib fractures. Interventions – None. Measurements and Main Results – Cats with rib fractures were identified by performing a computer search of the radiology database. Thirty‐three cats that sustained rib fractures were identified between January 2000 and September 2009. Seventeen cats had fractures due to trauma and 16 were deemed to occur from nontraumatic causes. A Mann‐Whitney rank‐sum test revealed statistically significant differences in the median ages between the 2 groups. Older cats were more likely to sustain rib fractures as a result of a presumed nontraumatic causes. A Chi‐square analysis showed that nontraumatic fractures occurred significantly more often in the midbody region and involved the 9th–13th ribs. The majority of cats with presumed nontraumatic rib fracture had respiratory disease; the remaining cats had chronic renal disease or neoplasia. Cats with traumatic rib fractures had external signs of trauma. Conclusion – Rib fractures in cats may be clearly associated with trauma, or may be an incidental finding in cats with comorbidities. Cats with diseases that cause prolonged respiratory effort or coughing, metabolic diseases, or certain neoplasms, are at increased risk of spontaneous nontraumatic rib fractures.     

Ecological and Physiological Studies of Gymnodinium catenatum in the Mexican Pacific: A Review

This review presents a detailed analysis of the state of knowledge of studies done in Mexico related to the dinoflagellate Gymnodinium catenatum, a paralytic toxin producer. This species was first reported in the Gulf of California in 1939; since then most studies in Mexico have focused on local blooms and seasonal variations. G. catenatum is most abundant during March and April, usually associated with water temperatures between 18 and 25 ºC and an increase in nutrients. In vitro studies of G. catenatum strains from different bays along the Pacific coast of Mexico show that this species can grow in wide ranges of salinities, temperatures, and N:P ratios. Latitudinal differences are observed in the toxicity and toxin profile, but the presence of dcSTX, dcGTX2-3, C1, and C2 are usual components. A common characteristic of the toxin profile found in shellfish, when G. catenatum is present in the coastal environment, is the detection of dcGTX2-3, dcSTX, C1, and C2. Few bioassay studies have reported effects in mollusks and lethal effects in mice, and shrimp; however no adverse effects have been observed in the copepod Acartia clausi. Interestingly, genetic sequencing of D1-D2 LSU rDNA revealed that it differs only in one base pair, compared with strains from other regions.     

Thermally induced phase separation in supported bilayers of glycosphingolipid and phospholipid mixtures

The authors have studied microstructure evolution during thermally induced phase separation in a class of binary supported lipid bilayers using a quantitative application of imaging ellipsometry. The bilayers consist of binary mixtures consisting of a higher melting glycosphingolipid, galactosylceramide (GalCer), which resides primarily in the outer leaflet, and a lower melting, unsaturated phospholipid, 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC). Three different bilayer compositions of GalCer/DLPC mixtures at 35:65, 20:80, and 10:90 molar ratios were cooled at controlled rates from their high-temperature homogeneous phase to temperatures corresponding to their phase coexistence regime and imaged in real time using imaging ellipsometry. During the thermotropic course of GalCer gelation, we find that two distinct types of morphological features modulate. First, the formation and growth of chain and fractal-like defects ascribed to the net change in molecular areas during the phase transition. The formation of these defects is consistent with the expected contraction in the molecular area during the liquid crystalline to gel-phase transition. Second, the nucleation and growth of irregularly shaped gel-phase domains, which exhibit either line-tension dominated compact shape or dendritic domains with extended interfaces. Quantifying domain morphology within the fractal framework reveals a close correspondence, and the quantization of the transition width confirms previous estimates of reduced phase transition cooperativity in supported bilayers. A comparison of domain properties indicates that thermal history, bilayer composition, and cooling rate all influence microstructure details including shapes, sizes, and distributions of domains and defects: At lower cooling rates and lower GalCer fractions compact domains form and at higher GalCer fractions (or at higher cooling rates) dendritic domains are evident. This transition of domain morphology from compact shapes to dendritic shapes at higher cooling rates and higher relative fractions of GalCer suggests kinetic control of shape equilibration in these phospho- and glycolipid mixtures.     

Genetic Analysis of Water Use Efficiency in Rice (Oryza sativa L.) at the Leaf Level

Carbon isotope discrimination (?¹³C) is considered as an index of leaf-level water use efficiency, an important objective for plant breeders seeking to conserve water resources. We report in rice a genetic analysis for ?¹³C, leaf structural parameters, gas exchange, stomatal conductance, and leaf abscisic acid (ABA) concentrations. Doubled haploid and recombinant inbred populations, both derived from the cross IR64 × Azucena, were used for quantitative trait locus (QTL) analysis following greenhouse experiments. ?¹³C QTLs on the long arms of chromosomes 4 and 5 were colocalized with QTLs associated with leaf blade width, length, and flatness, while a QTL cluster for ?¹³C, photosynthesis parameters, and ABA was observed in the near-centromeric region of chromosome 4. These results are consistent with phenotypic correlations and suggest that genetic variation in carbon assimilation and stomatal conductance contribute to the genetic variation for ?¹³C in this population.     

Mycoparasitism by Pythium oligandrum and P. acanthicum

Isolates of the reported mycoparasites Pythium oligandrum, P. acanthicum and P. periplocum markedly reduced growth and cellulolysis by Botryotrichum piluliferum, grew rapidly across agar plates precolonized by Phialophora radicicola var radicicola (sensu Deacon) and, where tested (not P. periplocum), were non-pathogenic towards higher plants. Isolates of P. echinulatum, P. mamillatum. P. megalacanthum, P. spinosum, P. ultimum and one isolate of P. acanthicum behaved differently from the mycoparasites and could, themselves, be placed in two groupings in these tests. It is suggested that the ability or otherwise to grow on Phialophora-precolonized agar plates may help to distinguish broad biological groupings within the genus Pythium, but these groupings may cut across conventional taxonomic ones.One isolate of P. acanthicum was tested for its effects on a range of cellulolytic fungi: it reduced their growth to different extents, as did P. oligandrum.Plates of potato-dextrose agar precolonized by Phialophora radicicola were used to isolate selectively P. oligandrum and similar fungi from soils, but the use of hemp seed baits in conjunction with precolonized plates was less selective for these fungi.Straw pieces precolonized by P. oligandrum and buried in soil decomposed at the same rate as virgin straws or those precolonized by P. ultimum or Mucor hiemalis. Subsequently, Stachyholrys atra appeared to colonize straws more frequently from soil, and Fusarium spp. less so, in the presence of P. oligandrum than in its absence. In the laboratory, P. oligandrum was antagonized by Slachyholrys, whereas Fusarium spp. were frequently overgrown by the Pythium.