Twenty-four hour Holter monitoring in finishing cattle housed outdoors.

INTRODUCTION: Atrial premature complexes have been reported to be the most common arrhythmia in cattle and is suspected to be secondary to systemic disease, especially gastrointestinal disease. In order to properly identify pathologic arrhythmia in cattle, the normal rhythm and arrhythmia prevalence should be defined. The objective of this study was to determine the normal heart rate, rhythm, number of ventricular premature complexes (VPCs), and atrial premature complexes (APCs) in unrestrained Angus steers. ANIMALS: Twenty-seven client owned steers with unremarkable physical examinations and serum biochemical analyses were used. MATERIALS AND METHODS: Twenty-four hour Holter monitors, attached by a custom-made harness, were retrospectively evaluated. Three lead electrocardiographic registrations of good quality and normal sinus rhythm were obtained from all steers in the study. RESULTS: The mean heart rate was 66.8 bpm ± 16.4 bpm. Ventricular premature complexes were rare (noted in 14.8% of steers), and APCs were common (noted in 85% of the steers). Simple second degree AV block was observed in 18.5% of the steers. CONCLUSION: In summary, healthy steers have rare single VPCs, although it is possible for an individual animal to have apparent more frequent VPCs. Mean heart rate varies with a diurnal pattern similar to other species. Atrial premature complexes are the most prevalent abnormality observed in feedlot steers.

Cattle handling technique can induce fatigued cattle syndrome in cattle not fed a beta adrenergic agonist.

Angus crossbred steers (n = 40; 563 ± 44 kg) were used to examine the effects of handling method and fat thickness on the blood chemistry and physiology of market steers. Steers were blocked by backfat (BF) thickness and were randomly assigned to treatment groups: low-stress handling (LSH) and aggressive handling (AH). Cattle were then ran¬domly assigned to one of 5 blocks containing 4 steers from the LSH and AH treatments. Steers in the LSH treatment were walked and AH cattle were run through a course of 1,540 m. Blood samples were obtained via jugular venipuncture before handling (BASE), at 770 m (LAP1), at 1,540 m (LAP2), and at1 h (1H) and 2 h (2H) after finishing the course. Blood samples were analyzed for plasma lactate (LAC), creatinine kinase (CK), base excess (BE), blood pH (pH), serum cortisol (CORT) concentrations, and venous carbon dioxide (PvCO2) and oxygen (PvO2) pressures. Heart rate (HR), respiratory rate (RR), and rectal temperature (TEMP) were measured at the same intervals. Cattle in the AH treatment had greater ( < 0.05) LAC than those in LSH at BASE (4.1 vs. 3.0 mmol/L), LAP1 (16.5 vs. 2.3 mmol/L), LAP2 (22.3 vs. 2.4 mmol/L), 1H (7.2 vs. 2.7 mmol/L), and 2H (4.0 vs. 2.5 mmol/L), respectively. Creatinine kinase and RR were not different (P > 0.14). Blood pH in AH cattle was decreased compared with that in LSH cattle ( < 0.05) at LAP1 (7.25 vs. 7.45) and LAP2 (7.19 vs. 7.48) but was not different ( > 0.13) at BASE, 1H, or 2H. Heart rate and TEMP were increased in AH cattle compared to LSH ( > 0.01). Serum cortisol was increased ( < 0.05) in AH compared to that in LSH cattle at LAP1 (87.5 vs. 58.9 nmol/L), LAP2 (144.4 vs. 93.1 nmol/L), and 1H (113.5 vs. 53.1 nmol/L). Although RR was not differ¬ent between LSH and AH, PvCO2 was decreased in AH compared to that in LSH ( < 0.05) at LAP2 (30.6 vs. 39.3 mmHg) and PvO2 was increased at LAP1 (42.7 vs. 33.5 mmHg) and at LAP2 (51.5 vs. 36.6 mmHg). Lactate was increased in AH cattle in the thicker BF group at 1H ( < 0.05), and blood pH was decreased at LAP1, LAP2, and 1H ( < 0.05) compared to the thinner BF cohorts. Four AH steers became exhausted (EXH) and did not complete the course. Increased CK, decreased PvCO2, and muscle tremors occurred in EXH steers compared to non-exhausted AH cohorts. Results of this study show that AH causes physiologic and blood chemistry changes in steers, which can be potentially detrimental to cattle, emphasizing the need for low-stress handling practices.

Seminal plasma and seminal plasma proteins added to bulk sorted sperm do not alter the mRNA expression of in vitro produced bovine embryos.

Although sex-sorted sperm have been used for AI and IVF for over a decade there is still need to improve the technology as the results are highly variable. The goal of the present study was to assess the effect of seminal plasma and seminal plasma proteins as a supplement to sorted sperm on subsequent embryonic development, as a beneficial effect of these substances has been reported. In vitro matured oocytes were fertilized in vitro with either unsorted sperm (n = 215; Group 1), bulk sorted sperm (n = 226; Group 2), bulk sorted sperm extended in the presence of 1% seminal plasma (n = 185; Group 3) or bulk sorted sperm supplemented with seminal plasma proteins (4 mg mL(-1); n = 254; Group 4). An additional group of oocytes (n = 307; Group 5) was fertilized with the semen of another bull routinely used for IVF and served as a laboratory standard control. Subsequently, the presumptive zygotes were cultured for 8 days under standard conditions (SOFaa, 39 °C, 5% CO(2), 5% N(2)). Cleavage rates were assessed on day 3 p.i. (post insemination; group 1: 30.5 ± 14.7%; group 2: 28.8 ± 9.8%; group 3: 20.8 ± 14.9%; group 4: 25.7 ± 8.2%; group 5: 54.8 ± 11.5%). Development rates were documented on days 7 p.i. (group 1: 7.3 ± 6.6%; group 2: 5.6 ± 3.1%, group 3: 6.2 ± 7.7%, group 4: 6.7 ± 5.9%, group 5: 20.2 ± 6.9%) and 8 p.i. (group 1: 8.9 ± 7.0%; group 2: 6.0 ± 2.9%; group 3: 8.6 ± 11.3%; group 4: 7.8 ± 6.2%; group 5: 23.3 ± 7.8%), respectively. Significant differences among cleavage and development rates could only be seen for Group 5 compared to all other groups. However, this difference between Groups 1-4 vs. Group 5 regarding the development rates on Day 8 could not be detected when assessing the development rates on base of the number of cleaved embryos instead of the number of oocytes fertilized (group 1: 31.4 ± 17.2%; group 2: 26.0 ± 21.0%; group 3: 33.3 ± 19.05%; group 4: 26.6 ± 17.8%; group 5: 42.6 ± 11.3%). The relative abundance of six different developmentally important gene transcripts (G6PD, HSP1A1, SLC2A3, BAX, BCL2L1, DNMT3A) was determined using single Day 8 expanded blastocysts of all five groups. No significant differences were seen among the embryos of the five groups. Our results show that neither the bulk sorting procedure nor the addition of seminal plasma or seminal plasma proteins, respectively, affected cleavage and development rates when sperm from a specific bull was used. Additionally, sorting and subsequent exposure of sperm to either seminal plasma or seminal plasma proteins did not influence mRNA expression in bovine IVP embryos.

Insemination with sex sorted fresh bovine spermatozoa processed in the presence of antioxidative substances.

Flow cytometrically sex sorted spermatozoa are reduced in their fertilizing capacity, particularly when stored either in cooling extender or after freezing in liquid nitrogen. So far, preservation methods for sorted spermatozoa have differed only marginally from procedures used for unsorted semen. In the present study, a TRIS extender was modified to balance major cell damage caused by the sorting process and by liquid storage of the sorted spermatozoa. The new extender, containing a combination of antioxidants (AO) and bovine serum albumin (BSA), significantly increased the lifespan and fertilizing capacity of sex sorted spermatozoa. No significant differences were observed between unsorted controls and sorted samples for motility and status of sperm membranes as tested by fluorescein-isothiocyanat-peanut agglutinin/propidium iodide (FITC-PNA/PI). Acrosome integrity of spermatozoa was significantly better when semen was stored at 15 degrees C for 24 and 48 h in an extender containing AO with or without BSA as compared with controls (p < 0.05). There were no significant differences, in pregnancy rates of heifers inseminated at a natural oestrus, between unsorted controls (16/24, 66.7%) and both sorted groups (AO + BSA: 18/31, 58.1% and AO-BSA: 12/22, 54.5%). Additionally, it was shown for the first time that artificial insemination (AI) with liquid sexed bull spermatozoa stored for 72 h after sorting can result in pregnancy rates similar to AI with non-sorted semen.

Single atoms in an optical dipole trap: towards a deterministic source of cold atoms

We describe a simple experimental technique which allows us to store a small and deterministic number of neutral atoms in an optical dipole trap. The desired atom number is prepared in a magneto-optical trap overlapped with a single focused Nd:YAG laser beam. Dipole trap loading efficiency of 100% and storage times of about one minute have been achieved. We have also prepared atoms in a certain hyperfine state and demonstrated the feasibility of a state-selective detection via resonance fluorescence at the level of a few neutral atoms. A spin relaxation time of the polarized sample of 4.2+/-0.7 s has been measured. Possible applications are briefly discussed.

Searching online and Web-based resources for information on natural products used as drugs.

Finding and evaluating information on natural products used as drugs can present challenges to the information professional. In this study, eight databases including resources retrieved on the Web were compared for relevancy and uniqueness. Ten reference questions related to natural products used as drugs were searched in the latest three year file of a number of databases, including MEDLINE, International Pharmaceutical Abstracts, and EMBASE/Excerpta Medica. In addition, the Web was searched for relevant Internet sites using the Alta Vista search engine. EMBASE/Excerpta Medica retrieved the largest number of relevant citations for four of the ten questions. MEDLINE, the Health Reference Center, and Alta Vista each retrieved the largest numbers in two questions. Overall, the standard medical databases were the first choice for the health professional and for many lay people because of their more extensive indexing and coverage of authoritative journals.

Mutational analysis of the Streptomyces lividans recA gene suggests that only mutants with residual activity remain viable.

Temperature-sensitive integration plasmids carrying internal fragments of the Streptomyces lividans TK24 recA gene were constructed and used to inactivate the chromosomal recA gene of S. lividans by gene disruption and gene replacement. Integration of these plasmids resulted in recA mutants expressing C-terminally truncated RecA proteins, as deduced from Southern hybridization experiments. Mutants FRECD2 in which the last 42 amino acids, comprising the variable part of bacterial RecA proteins, had been deleted retained the wild-type phenotype. The S. lividans recA mutant FRECD3 produced a RecA protein lacking 87 amino acids probably including the interfilament contact site. FRECD3 was more sensitive to UV and MMS than the wild-type. Its ability to undergo homologous recombination was impaired, but not completely abolished. Integration of the disruption plasmid pFRECD3 in S. coelicolor "Müller" caused the same mutant phenotype as S. lividans FRECD3. In spite of many attempts no S. lividans recA mutants with deletions of 165 C-terminal amino acids or more were isolated. Furthermore, the recA gene could not be replaced by a kanamycin resistance cassette. These experiments indicate a crucial role of the recA gene in ensuring viability of Streptomyces.

Oxidative stress and ageing in the fungus Podospora anserina.

The ageing phenomenon exhibited by the ascomycetous fungus Podospora anserina can be either delayed or induced by either different carbon sources or effectors. As these effects seem to have analogy to catabolite-repression of respiratory genes, experiments concerning respiratory functions have been carried out. Ageing is parallelled by switching from cytochrome c-oxidase-mediated respiration to alternative, cyanide-resistant respiration for reasons still unknown. The latter is always accompanied by appearance of the phenol oxidizing enzyme laccase (EC 1.10.3.2), which seems to act as an alternative oxidase. The existence of a second, non-mitochondrially encoded respiratory pathway relieves the selective pressure on mitochondria leading to disintegrated, non-functional mtDNA and thereby whole mitochondria which accumulate in the hyphal cells. Mutants lacking cytochrome c-oxidase aa3 or laccase have stable mitochondrial populations and live eternally.

Oral diadochokinesis in hearing-impaired adolescents.

Oscillographic tracings for time-by-count measures of diadochokinetic syllable rate (Fletcher, 1972) were collected from a group of 30 hearing-impaired and five normal-hearing high-school students. Results indicated that hearing-impaired subjects performed significantly slower on all speech-timing tasks than their normal-hearing peers. Within-group differences were identified for the hearing-impaired subjects with respect to speech intelligibility, degree of hearing loss, and gender. The differences, in general, indicate that for varying degrees of hearing loss severity there are speech-timing coordination deficits commensurate to that level.