Alterations of selected intestinal enzymes in hamsters with hamster enteritis syndrome.

Portions of duodenum, jejunum, and ileum from 21 hamsters clinically affected with enteritis were examined for enzymes. Utilizing a variety of techniques, the activities of alkaline phosphatase, nonspecific esterases, leucine aminopeptidase, beta-glucuronidase, and methyl green pyroninophilia were determined. The activities of enzymes normally associated with tissue proliferation and active protein synthesis were decreased, whereas those enzymes associated by cytolysis were increased.     

An experimental sod seeder

The design and development of an efficient sod‐seeder for the Ngongoni Veld of Natal is described.     

Comparison of biopsy samples obtained using standard endoscopic instruments and the harmonic scalpel during laparoscopic and laparoscopic-assisted surgery in normal dogs

Objectives— To compare tissue specimens of canine abdominal organs collected by standard techniques (ST) and harmonic scalpel (HS) and to determine the effect of each technique on wound healing.
Study Design— Experimental.
Animals— Twelve dogs.
Methods— Paired biopsy samples (ST, HS) were collected from liver, spleen, adrenal gland, pancreas, stomach, jejunum, and bladder using laparoscopic or laparoscopic-assisted methods. Hemorrhage at biopsy sites was assessed (present or absent). Specimens were evaluated for diagnostic quality and histologic changes. Dogs were necropsied at 4 or 14 days postoperatively.
Results— HS incision caused less frequent hemorrhage of all organs except spleen. HS specimens had more coagulation necrosis than ST specimens, but both techniques yielded specimens that were sized similarly and were of diagnostic quality. At necropsy, HS biopsy sites of the stomach, jejunum, bladder, adrenal gland, and pancreas were more hyperemic than ST sites. There were more adhesions at jejunal and pancreatic ST biopsy sites. HS biopsy sites had more coagulation necrosis at days 4 and 14 postoperatively. Differences in fibrin deposition, inflammation, and fibrosis were present at biopsy sites of some organs at days 4 or 14 and in comparisons between days 4 and 14.
Conclusions— Diagnostic quality biopsy specimens were obtained with HS and ST. Although HS-induced gross and histologic changes during the first 2 postoperative weeks, no clinical complications were observed.
Clinical Relevance— Both HS and ST can yield specimens with minimal hemorrhage and HS resulted in no apparent postoperative problems in normal dogs. Although HS caused more inflammation and adhesions at biopsy sites of the pancreas, adrenal gland, and jejunum, no clinical complications occurred.     

Genotypic and environmental variation in crop yield. A method of estimating the interdependence of the components of yield

Summary Because yield components do not behave as independent attributes the conclusions derived from simple yield analyses are of limited value in plant breeding programmes. By calculating a function W of the variances and covariances of the yield components, it is possible to estimate, on a scale from 0 to 1, the degree to which the variations in yield components were independent of one another in any given experiment. By this approach examples of almost complete compensation among the components (W = 0), of mutual independence of the components (W = 0.5), and of additivity of the components (W = 1.0) have been discovered in original data and in the literature. Reasons, and possible applications for these findings are discussed. Investigations into the sampling properties of W are reported in an appendix.     

The effect of phenothiazine on cobalt-deficient and cobalt-dosed lambs

The mean serum folate concentrations of Large White sows were compared between one group of 13 animals, 43–80 days pregnant and another group of 9 animals at weaning when the litters were 28–30 days old. The mean concentration was higher in sows at weaning (p<0.05) and the lowest levels were found in sows no more than 51 days pregnant (p<0.05).     

Glutathione transferase activities toward herbicides used selectively in soybean

Using extracts from suspension-cultured cells of soybean (Glycine max cv. Mandarin) as a source of active enzymes, the activities of glutathione transferases (GSTs) catalysing the conjugation of 1-chloro-2,4-dinitrobenzene (CDNB) and selective herbicides were determined to be in the order CDNB≫ fomesafen>metolachlor=acifluorfen>chlorimuron-ethyl. GST activities showed a thiol dependence in a substrate-specific manner. Thus, GST activities toward acifluorfen and fomesafen were greater when homoglutathione (hGSH), the endogenously occurring thiol in soybean, was used as the co-substrate rather than glutathione (GSH). Compared with GSH, hGSH addition either reduced or had no effect on GST activities toward other substrates. In the absence of enzyme, the rates of hGSH conjugation with acifluorfen, chlorimuron-ethyl and fomesafen were negligible, suggesting that rapid hGSH conjugation in soybean must be catalysed by GSTs. GST activities were subsequently determined in 14-day-old plants of soybean and a number of annual grass and broadleaf weeds. GST activities of the plants were then related to observed sensitivities to post-emergence applications of the four herbicides. When enzyme activity was expressed on a mg^-1 protein basis, all grass weeds and Abutilon theophrasticontained considerably higher GST activity toward CDNB than soybean. With fomesafen as the substrate, GST activities were determined to be in the order soybean≫Echinochloa crus-galli>Digitaria sanguinalis>Sorghum halepense=Setaria faberi with none of the broadleaf weeds showing any activity. This order related well to the observed selectivity of fomesafen, with the exception of A. theophrasti, which was partially tolerant to the herbicide. Using metolachlor as the substrate the order of the GST activities was soybean>A. theophrasti≫S. halepense>Amaranthus retroflexus>Ipomoea hederacea, with the remaining species showing no activity. GST activities toward metolachlor correlated well with the selectivity of the herbicide toward the broadleaf weeds but not toward the grass weeds. Acifluorfen and chlorimuron-ethyl were selectively active on these species, but GST activities toward these herbicides could not be detected in crude extracts from whole plants. © 1997 SCI