Degradation of ioxynil by a soil fungus, Fusarium solani

A fungus, Fusarium solani, isolated from the soil, degraded ioxynil (3,5-diiodo-4-hydroxyben-zonitrile) in pure culture into at least eight products. Five products were detected in the organic fractions extracted from a culture grown in [¹⁴C]cyano-labeled ioxynil. Three additional products were separated by ion-exchange chromatography of the acidified aqueous phase. Cultures grown in the presence of [¹⁴C]ring-labeled ioxynil produced the same products in the organic extract and four to five products in the aqueous phase. The cyano-carbon of ioxynil was released as CO₂ at a faster rate than that of ring-carbons and was released after the initial ring cleavage. Two of the metabolites were identified as 3,5-diiodo-4-hydroxybenzamide and 3,5-diiodo-4-hydroxybenzoic acid.     

Seasonal Effect on Zebu Embryo Quality as Determined by Their Degree of Apoptosis and Resistance to Cryopreservation

In order to optimize the production of embryos under tropical conditions and to test a possible seasonal effect on embryo quality, 40 Zebu cows were superovulated during the dry season (April to May) and during the rainy season (July to August). A total of 116 (average 2.7/cow) and 83 embryos (3.5 average/cow) were obtained during the respective seasons. After classification as good, fair or poor quality, embryos were tested based on their ultrastructural differences (n = 53 dry season 16 good, 20 fair and 17 poor and n = 61 rainy season 21 good, 20 fair and 20 poor) and their degree of apoptosis using the TUNEL technique (n = 30 during the dry season and n = 55 in the rainy season). Structural characteristics determining embryo quality varied between good and fair quality embryos. No difference, however, was observed between good, fair and poor quality embryos from the two seasons. The number of TUNEL-positive cells was different among embryos (p < 0.001), being lower in labelled cells of good quality embryos regardless of the season. Fewer apoptotic cells were observed in embryos assigned in all three quality levels during the rainy season (p < 0.001). Ultrastructural evaluations confirmed the results obtained by TUNEL. Cryopreserved embryos of good (n = 25 in each season) and fair quality (n = 11 dry season; n = 17 rainy season) showed a significant decrease of TUNEL-positive cells during the rainy season (p < 0.05). Results suggest that embryos collected in the dry season have more cellular damage in contrast; embryos cryopreserved in the rainy season appeared morphologically better equipped to result in a pregnancy following transfer.     

Ovarian hemangioma in swine

Eighteen (3.9%) ovarian hemangiomas were diagnosed in a survey of reproductive disorders in 460 sows from two to eight years of age during a three-year study. Ovarian hemangiomas only were observed in sows aged over 30 months, and no such neoplasms were found in 42 gilts. The incidence of ovarian hemangioma was highest at five to eight years of age. Of the 18 sows with ovarian hemangioma, one was purebred and 17 were crossbred pigs; of these, twelve had farrowed 12 to 15 litters, four had farrowed six to 11 litters and two had farrowed three litters. All 18 sows with ovarian hemangioma had one or more clinical signs related to reproductive disorders including small litter size, agalactia, fertilization failure, fetal death, silent estrus, anestrus, abortion, and stillbirth. The pathological features of the neoplasms in sows were similar to those described previously in swine and in man. Spontaneous ovarian hemangioma might provide a model for investigation of the etiology and pathogenesis of ovarian hemangioma in man.     

Use of hyperimmune serum, vaccination, and certain management procedures for control of pseudorabies in swine

A program involving use of hyperimmune serum, vaccination, and certain management procedures for the control of pseudorabies was evaluated on several farms on which the disease was enzootic. Neonatal mortality and reproductive failures on farms utilizing the program were compared with death losses and reproductive failures on farms not utilizing the program. The reduction in preweaning mortality and reproductive failures between the treated and nontreated groups were 42.1% and 39.6%, respectively.     

Antibacterial effect of chloramphenicol, thiamphenicol and florfenicol against aquatic animal bacteria

The minimum inhibitory concentration (MIC) was measured to evaluate the antibacterial activities of chloramphenicol (CP), thiamphenicol (TP) and florfenicol (FFC) against the aquatic bacterial isolates from soft-shell turtles, fish and shellfish. Amoxicillin (AMPC), oxytetracycline (OTC) and oxolinic acid (OA) were included to compare with above protein synthesis inhibitors. The results showed that the order of MIC range of the isolates from soft-shell turtles for tested drugs was OA>FFC, CP>TP> AMPC, OTC. The percentage of the resistant strains indicated that OA was the lowest (7.14%) and OTC was the highest (85.07%). The order of antibacterial activity against the isolates from fish was OA>FFC>CP>AMPC>OTC>TP. The percentage of the resistant strains revealed that OA (13.64%) and OTC (80.91%) were the lowest and the highest, respectively. For the isolates from shellfish, the order of antimicrobial activity was OA>CP, FFC>AMPC, OTC, TP. TP showed the greatest percentage of the resistant strains (58.7%), but that of OA was the lowest (4.35%). The most common resistant patterns of the isolates from turtles, fish and shellfish were AMPC-OTC, CP-TP-AMPC-OTC, and FFC-CP-TP-AMPC-OTC, respectively. There were partially-complete resistance of the resistant isolates among CP, TP and FFC. The findings indicated that previous treatment might affect the choice of drug to use for aquatic bacterial diseases.     

Corynebacterium pseudotuberculosis exotoxin: fatal hemolytic anemia induced in gnotobiotic neonatal small ruminants by parenteral administration of preparations containing exotoxin

Inoculation of live Corynebacterium pseudotuberculosis, culture supernatant, ammonium sulfate-fractionated crude exotoxin, or chromatographically purified exotoxin preparations into gnotobiotic small ruminants (n = 13) caused death of the ruminants within 48 hours. Characteristic changes observed in animals living greater than or equal to 2 hours after inoculation included hemorrhage and edema at the site of injection, severe hemolytic anemia and hemoglobinuria, dark red fluid in body cavities, lung edema, and icterus. The crude exotoxin preparation caused a syndrome of acute shock in 2 lambs that died within 15 minutes after inoculation. Clinical and pathologic responses of animals inoculated with culture supernatant and purified toxin were similar. Histopathologic evidence indicated that the exotoxin caused necrotic changes in the proximal convoluted tubules of the kidneys. Inoculation with live organisms caused multiple foci of suppurative inflammation in skeletal muscle and adjacent adipose tissue, whereas such changes were not observed in animals administered exotoxin preparations. Although C pseudotuberculosis exotoxin induced a hemolytic anemia in the experimental animals, it did not lead to in vitro lysis of ovine, caprine, or bovine erythrocytes, unless they had been sensitized with Rhodococcus (Corynebacterium) equi filtrate. The toxic sphingomyelin-specific phospholipase D from C pseudotuberculosis had a molecular weight of 31,000 daltons and an isoelectric point of approximately 9.6. The elution profile of exotoxin on a carboxymethyl Sephadex column was studied and the majority of the enzymatic activity was eluted by a NaCl gradient (0.25M to 0.7M) with a maximum at 0.35M NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)     

Antagonism of xylazine-pentobarbital anesthesia by yohimbine in ponies

Effects of yohimbine on xylazine-pentobarbital anesthesia were evaluated in ponies. Five minutes after the IV injection of xylazine (1.1 mg/kg of body weight), pentobarbital sodium (12.7 mg/kg, IV) and additional xylazine (2.2 mg/kg, IM) were given and produced anesthesia in 12 ponies for 64.0 +/- 16.4 minutes (mean +/- SD) as well as immobilization for 89.8 +/- 34.2 minutes. Eleven ponies were given yohimbine (0.1 mg/kg, IV) 50 minutes after pentobarbital dosing. In these 11 ponies, durations of anesthesia and immobilization were shorter, 52.0 +/- 1.4 and 65.5 +/- 14.8 minutes, respectively. The xylazine-pentobarbital combination caused bradycardia that was reversed by yohimbine injection. Xylazine-pentobarbital produced a small, but steady, decrease of mean arterial blood pressure, which was compounded by yohimbine administration and was evident for approximately 2 minutes. Within a minute after yohimbine injection, the ponies' respiratory rate decreased and the length of inspiration and expiration and thoracic breathing increased. This lasted approximately 2 to 3 minutes and was followed by an increase in respiratory rate. The anesthesia also produced a decrease in PaO2 that gradually returned to base line in 12 control ponies, but was more pronounced in 11 ponies given yohimbine. The PaCO2, although remaining moderately high in control ponies, returned to base line after yohimbine injection. An increased pHa was seen 60 minutes after induction of anesthesia and was especially noticeable after yohimbine administration. Decreases in the number of WBC, hemoglobin content, PCV, plasma protein and serum aspartate transaminase resulting from xylazine-pentobarbital were reversed by yohimbine. Conversely, serum glucose values and creatine kinase activities were increased by xylazine-pentobarbital.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early migration of radiolabeled larvae of Fasciola hepatica in the mouse

Metacercariae of Fasciola hepatica were labeled with 75Se by exposure of infected Lymnaea columella to 75Se-M, 20 muCi/snail, in 5 ml of water. Seventy-two mice were inoculated with 50 75Se-labeled metacercariae. At intervals after infection, the distribution of metacercariae in gut, body cavities and liver was studied by compressed organ autoradiography, and a variant of this technique adapted to gut content and body cavity washes. Ag degree focus counts from autoradiograms expressed as percentage of actual exposure level were subjected to probit analysis. Estimates of the average departure time of radio-labeled maritas from gastrointestinal tracts and average arrival time into the abdominal cavities were 12.2 and 12.5 h, respectively. The peak accumulation of maritas in abdominal cavities occurred at 24 h post-inoculation. A 7.7-h discrepancy between estimated average departure time from abdominal cavities (92 h) and average arrival time at livers (99.7 h) was attributed to experimental error.     

On mechanical behavior of traditional timber shear wall in Taiwan I: background and theory derivation

The objectives of this study were to explore the mechanical behavior of traditional timber shear walls in Taiwan and to propose a theoretical model to predict their lateral force resistance. An extensive field investigation was conducted, and the dimensions, tectonic detail, and materials used were recorded. The data collected were used as the reference for theoretical derivation and experimental design. In the theoretical model, the moment resistance of entire shear walls was derived from the contributions of the moment-resisting capacity supplied not only by embedment and friction action between board units and beams but also the dowel action of bamboo nails. Timber shear walls with various geometric conditions and material properties are considered. The theoretical model demonstrated in this study can be used to predict the mechanical behavior of timber shear walls and will be verified by experiments in our next article.     

Shrinkage stresses in wood logs considered as layered,cylindrically orthotropic materials

Summary The deformation and stresses in a circular wood log resulting from an arbitrary radial moisture distribution are examined. In this paper the log is modeled as a layered cylinder, with each layer assumed to be linearly elastic, cylindrically orthotropic, and homogeneous. The general solution to the equations of elasticity for a representative layer is given; constants of integration in the solution are determined through application of appropriate continuity conditions at the layer interfaces. Numerical examples are presented for logs of Scots pine which illustrate the effect of nonuniform moisture content upon the displacement and stress distributions.