Using statistical process control methods to improve herd performance.

Statistical process control (SPC) is a set of analytic methods that uses the theory of variation as a means of explaining with statistical certainty when process performance is improving, staying the same, or getting worse. SPC techniques have been used successfully for 80 years in manufacturing as a quality management tool. It is apparent that these techniques can be applied equally well to livestock production systems. The availability of large amounts of automatically collected data, the advances in computer capability, and the obvious need for more timely fact-based information for day-to-day management make SPC application the next step in improving herd management quality.     

Surgical denervation of porcine ovaries during the middle luteal phase of the oestrous cycle changes their morphology and steroidogenic activity

Changes in both the morphology and the steroidogenic activity of porcine ovaries denervated surgically on day 12 of the oestrous cycle were studied. Neurectomy of the plexus and the superior ovarian nerves caused a dramatic reduction in the number (or even a disappearance) of dopamine-beta-hydroxylase- and/or neuropeptide tyrosine-immunoreactive nerve terminals. On day 20 of the subsequent oestrous cycle, the number of small follicles increased (P < 0.01) and that of large follicles decreased (P < 0.05) in the denervated ovaries, as compared to the controls. Neurectomy led to a decrease in the level of progesterone (P4; P < 0.001) and androstenedione (A4; P < 0.01) in the fluid from small follicles, A4 (P < 0.001) and testosterone (T; P < 0.05) in the fluid from medium-sized follicles, as well as in the content of all these steroids in the fluid from large-sized follicles (P < 0.001 for P4 and P < 0.05 for A4 and T). Denervation also caused a decrease in the content of A4 (P < 0.01) and T (P < 0.001) in the wall of follicles. Neurectomy resulted in a significant increase in the immunoexpression of cholesterol side-chain cleavage cytochrome P450 in the follicles and a decrease of 33-hydroxysteroid dehydrogenase. After denervation, plasma levels of LH, P4, A4, T, oestrone and oestradiol-17beta were lower (P < 0.05-0.001) on the particular days of the study than in the control group. Our data revealed that the denervation of ovaries during the middle luteal phase of the oestrous cycle in gilts caused distinct changes in both the morphology and the steroidogenic activity of the organ, confirming an important role of the peripheral nervous system in the control of the gonad in this species.     

Early stages of infection of maize (Zea mays) and Pennisetum setosum roots by the parasitic plant Striga hermonthica

Infection of young roots of maize (Zea mays L.) by the parasitic plant Striga hermonthica (Del.) Benth. was examined. Attachment to and penetration of roots occurred within 1–2 days after inoculation. Subsequent growth through the cortex to the host stele and proliferation of parasite xylem tissue was commonly completed by 3–4 days after inoculation. Histochemical staining showed that young maize roots do not contain major wall-thickening components. However, an increase in cell wall fluorescence and endodermal cell wall thickness was often seen at the site of infection and in the surrounding maize root tissue at 3 days after inoculation. This host response was variable and did not prevent rapid and successful penetration by the parasite. In contrast, uninfected roots of Pennisetum setosum (Sw.) L. Rich., a species resistant to S. hermonthica, had substantial thickening of the inner endodermal cell walls and exhibited further cell wall thickening at the stele upon infection. Examination of infections on both hosts demonstrated the presence of autofluorescent material at the host-parasite interface. This material was thicker and more extensive at the P. setosum-S. hermonthica interface than at the maize-S. hermonthica interface, and contained polyphenols and lignin. Examination of the host-parasite xylem connections in maize revealed substantial invasion of the host stele by both parenchyma and tracheary elements. In a few cases of P. setosum infection, parasite cells entered the stele; however, this did not lead to successful establishment of the parasite.     

The effect of inotropic and/or vasopressor support on postoperative survival following equine colic surgery

OBJECTIVE: To determine the effects of dobutamine and phenylephrine on intra- and postoperative survival in horses undergoing emergency abdominal surgery. STUDY DESIGN: Retrospective case analysis. ANIMALS: A total of 637 client-owned horses undergoing colic surgery. METHODS: Clinical details of horses admitted for colic surgery were recorded on a computer database. Information collected included history, clinical variables observed before surgery, anaesthesia and surgical details, and postoperative survival and morbidity rates. Details of specific importance for this study were those recorded during anaesthesia, in particular the duration of dobutamine and phenylephrine administration, separately and combined, and total anaesthesia time. Two outcomes were considered: 1) intra-operative death, i.e. death between time of pre-anaesthetic medication and recovery from anaesthesia (defined as horse walking from recovery box); and 2) all deaths, i.e. death at any time after induction of anaesthesia. The definition of 'death' included euthanasia. Univariable and multivariable statistical analyses were performed to evaluate the associations between dobutamine and/or phenylephrine use and these two outcomes. RESULTS: Results from univariable analyses suggested that dobutamine administration was not significantly associated with increased intra- or postoperative mortality. Phenylephrine administration showed univariable association with intra- and postoperative death. However, in multivariable models adjusted for the effects of heart rate and packed cell volume at admission, the phenylephrine effect was not significantly associated with intra-operative, or other types of death. CONCLUSION: This study provides no evidence to suggest that dobutamine or phenylephrine administration is associated with altered survival rates during or after colic surgery. CLINICAL RELEVANCE: Our study supports previous work, suggesting that pre-existing cardiovascular status is an important prognostic determinant in equine colic cases. It provides no evidence that dobutamine or phenylephrine administration is associated with survival.     

Passage of heme-iron across the envelope of Staphylococcus aureus

The cell wall envelope of Gram-positive pathogens functions as a scaffold for the attachment of virulence factors and as a sieve that prevents diffusion of molecules. Here the isd genes (iron-regulated surface determinant) of Staphylococcus aureus were found to encode factors responsible for hemoglobin binding and passage of heme-iron to the cytoplasm, where it acts as an essential nutrient. Heme-iron passage required two sortases that tether Isd proteins to unique locations within the cell wall. Thus, Isd appears to act as an import apparatus that uses cell wall-anchored proteins to relay heme-iron across the bacterial envelope.     

DOPPLER ECHOCARDIOGRAPHY IN THE DOG: MEASUREMENT VARIABILITY AND REPRODUCIBILITY

Serial Doppler echocardiographic examinations were carried out in random order on six boxer dogs, on 3 separate days, by two experienced Doppler echocardiographers, to assess measurement variability and reproducibility of 65 parameters. Large numbers of parameters exhibited significant differences for each of the categories of intraobserver, interobserver, interday and interoperator. The coefficients of variation for all parameters measured ranged from 5.03 to 46.43%, but most were less than 20%. In general, least variation was found for the intraobserver category, and the best reproducibility for M-mode and left ventricular volumetric data. The worst reproducibility was found for tricuspid inflow and pulmonary venous flow measurements. The results of this study suggest differences greater than 20% for serial scans must be achieved to document genuine change, although the specific data should be consulted. Furthermore, variability and reproducibility are improved if a single experienced operator/observer acquires and measures serial scans.     

A functional dosage compensation complex required for male killing in Drosophila

Bacteria that selectively kill males ("male-killers") were first characterized more than 50 years ago in Drosophila and have proved to be common in insects. However, the mechanism by which sex specificity of virulence is achieved has remained unknown. We tested the ability of Spiroplasma poulsonii to kill Drosophila melanogaster males carrying mutations in genes that encode the dosage compensation complex. The bacterium failed to kill males lacking any of the five protein components of the complex.     

A metastatic secretory gastric plasmacytoma with aberrant CD3 expression in a dog

A 10‐year‐old crossbred dog was presented with a 6‐week history of hematemesis, melena, anorexia, and lethargy. Clinical evaluation revealed a gastric mass with a regional lymphadenomegaly as well as a monoclonal gammopathy manifesting as hyperglobulinemia. Cytologic and histopathologic analyses were consistent with a round cell neoplasm; neoplastic cells showed nuclear immunoreactivity for MUM1 and diffuse cytoplasmic reactivity for CD3. Polymerase chain reactions performed on fixed and fresh tissue identified a clonal rearrangement with an IgH primer set. An extramedullary plasmacytoma (EMP) was confirmed by cellular morphology and molecular diagnostics. Following an objective response to chemotherapy, the dog was euthanized 8 months after diagnosis, and a postmortem examination confirmed the clinical findings. This is the first reported case of a monoclonal gammopathy secondary to a gastric EMP coupled with aberrant expression of CD3 in an aggressive plasmacytic tumor, and highlights the utility of molecular diagnostics for classifying atypical hemolymphoid neoplasms.