A comparison of the effects of carbon dioxide and medical air for abdominal insufflation on respiratory parameters in xylazine-sedated sheep undergoing laparoscopic artificial insemination

AIMS: To determine if abdominal insufflation with medical air will improve oxygenation and ventilation parameters when compared to insufflation with CO₂ in xylazine-sedated sheep undergoing laparoscopic artificial insemination (AI).

METHODS: Forty-seven sheep underwent oestrus synchronisation and were fasted for 24 hours prior to laparoscopic AI. Each animal was randomised to receive either CO₂ or medical air for abdominal insufflation. An auricular arterial catheter was placed and utilised for serial blood sampling. Respiratory rates (RR) and arterial blood samples were collected at baseline, after xylazine (0.1?mg/kg I/V) sedation, 2 minutes after Trendelenburg positioning, 5 minutes after abdominal insufflation, and 10 minutes after being returned to a standing position. Blood samples were collected in heparinised syringes, stored on ice, and analysed for arterial pH, partial pressure of arterial O₂ (PaO₂), and CO₂ (PaCO₂). The number of ewes conceiving to AI was also determined.

RESULTS: Repeated measures ANOVA demonstrated temporal effects on RR, PaO₂, PaCO₂ and arterial pH during the laparoscopic AI procedure (p<0.001), but no difference between insufflation groups (p>0.01). No sheep experienced hypercapnia (PaCO₂>50?mmHg) or acidaemia (pH<7.35). Hypoxaemia (PaO₂<70?mmHg) was diagnosed during the procedure in 14/22 (64%) ewes in the CO₂ group compared with 8/23 (35%) ewes in the medical air group (p=0.053). Overall, 15/20 (75%) ewes in the CO₂ group conceived to AI compared with 16/22 (72.7%) in the medical air group (p=0.867).

CONCLUSIONS AND CLINICAL RELEVANCE: There were no statistical or clinical differences in RR, PaO₂, PaCO₂, pH, or conception to AI when comparing the effects of CO₂ and medical air as abdominal insufflation gases. None of the sheep experienced hypercapnia or acidaemic, yet 42% (19/45) of sheep developed clinical hypoxaemia, with a higher percentage of ewes in the CO₂ group developing hypoxaemia than in the medical air group. Based on the overall analysis, medical air could be utilised as a comparable alternative for abdominal insufflation during laparoscopic AI procedures.     

Effects of Confluent, Roscovitine Treatment and Serum Starvation on the Cell-cycle Synchronization of Bovine Foetal Fibroblasts

The present study was designed to examine the effects of cell-cycle synchronization protocols, such as confluent, roscovitine treatment and serum starvation, in bovine foetal fibroblasts on synchronization accuracy at G0/G1, viability, apoptosis, necrosis and ploidy for use as a nuclei donor. The cells in 5-10 passages were randomly allocated into three treated groups. Cells were cultured either in Dulbecco's modified Eagle's medium (DMEM) + 10% foetal bovine serum (FBS) until 90% confluent (group 1, confluent), in DMEM + 10% FBS + 30 microM roscovitine for 12 h (group 2, roscovitine), or in DMEM + 0.5% FBS for 5 days (group 3, serum starvation). Most of the cells (>80%) in all groups were arrested at the G0/G1 stage. Although the rates did not differ, cells in group 1 showed an increased cell population arrested at the G0/G1 phase. Significantly (p < 0.05) higher rates of apoptosis occurred in group 3 than in group 1 and 2 (10% vs 6% and 6%, respectively). No differences in chromosomal abnormality were observed among groups. However, by increasing the number of cell culture passages up to 15, significantly (p < 0.05) higher chromosomal abnormality was observed than in 5 and 10 passages (39% vs 28% and 23%, respectively) in group 1. The results clearly indicated that bovine foetal fibroblasts could be effectively synchronized at G0/G1 stages by all the three different treatments, confluent, roscovitine and serum starvation. However, cells in confluent showed reduced apoptosis and necrosis when they underwent 5-10 passages, exhibiting increased percentage of cells with stable chromosome diversity. Hence, cells in confluent merit further studies before they could be used as nuclear donors.     

Equine pituitary pars intermedia dysfunction: current understanding and recommendations from the Australian and New Zealand Equine Endocrine Group

The purpose of this article is to provide a review of the current knowledge and opinions about the epidemiology, clinical findings (including sequelae), diagnosis, treatment and monitoring of equine pituitary pars intermedia dysfunction, particularly in the Australian context. This information and the recommendations provided will assist practitioners in making informed decisions regarding the diagnosis and management of this disorder.     

Seed banks of some arable soils in the English midlands

Numbers of viable seeds in the 0–15 cm soil layer were determined for 64 arable fields, mainly heavy soils cropped with cereals and leys, in north Oxfordshire and south Warwickshire. When first sampled in 1972 or 1973, there was a range from 1500 to 67 000 seeds m^?2 with a median of 4360 m^?2. Seeds of Poa annua L. occurred in all fields, often in large numbers (up to 35 550 m^?2), while Polygonum aviculare L., Stellaria media (L.) Vill., Bilderdykia convolvulus (L.) Dumort., Aethusa cynapium L., Alopecurus myosuroides Huds., Veronica persica Poir., Chenopodium album L., Veronica arvensis L. and Capsella bursa-pastoris (L.) Med. also occurred frequently. When the fields were sampled again 2 and 4 years later many showed little change either in total seed bank or in species representation. The most pronounced fluctuations involved the annual grasses A. myosuroides, which tended to increase where winter cereals were grown, and P. annua which increased where leys were established. The results are discussed in relation to crop management and compared with those from other surveys. Les stocks de graines dans quelques sols arables des Midlands d'Angleterre Le nombre des graines viables présentes entré 0 et 15 cm de profondeur a été déterminé pour 64 sols arables, principalement des sols lourds occupés par des céréales et des prairies temporaires, dans le nord de l'Oxfordshire et le sud du Warwickshire. Lors de la première estimation, en 1972 ou 1973, les comptages ont donné de 1500 à 67 000 graines m^?2 avec une médiane de 4360. Des graines de Poa annua L. ont été trouvées dans tous les champs, souvent en grand nombre (jusqu'à 35 550 m^?2); on a aussi trouvé fréquemment des graines de Polygonum aviculare L., Stellaria media (L.) Vill., Bilderdykia convolvulus (L.) Dumort., Aethusa cynapium L., Alopecurus myosuroides Huds., Veronica persica Poir., Chenopodium album L., Veronica arvensis L. et Capsella bursa-pastoris (L.) Med. Beaucoup de dénombrements opérés 2 et 4 ans plus tard n'ont montré que peu de changements du nombre total de graines ou de la représentation des diverses espèces. Les fluctuations les plus notables ont été observées à propos des graminées annuelles A. myosuroides, qui tendaient à s'accroitre dans les cultures de céréales, et P. annua, qui augmentait dans les prairies temporaires. Les résultats sont discutés en relation avec la conduite des cultures et comparés avec ceux d'autres dénombrements. Samenvorrat in einigen Ackerböden in Mittelengland In den obersten 15 cm von 64, meist schweren, mit Getreide oder Grasgemischen bepflanzten Ackerböden im nördlichen Oxfordshire und südlichen Warwickshire wurde die Anzahl keimfähiger Samen bestimmt. Bei der ersten, 1972 oder 1973 erfolgten, Bestandesaufnahme wurden zwischen 1500 und 67 000, im Mittel 4360 Samen m^?2 gezählt. In allen Böden wurden Samen von Poa annua L., oft in sehr grosser Zahl (bis zu 35 550 m^?2), gefunden. Häufig waren auch Polygonum aviculare L., Stellaria media (L.) Vill., Bilderdykia convolvulus (L.) Dumort., Aethusa cynapium L., Alopecurus myosuroides Huds., Veronica persica Poir., Chenopodium album L., Veronica arvensis L. und Capsella bursa-pastoris (L.) Med. 2 und 4 Jahre später durchgeführte Zählungen zeigten in vielen Fällen nur geringe Veränderungen, sowohl in Bezug auf Samenzahl als auch auf vorhandene Arten. Die markantesten Aenderungen wurden bei anuellen Gräsern festgestellt; so zeigte A. myosuroides eine zunehmende Tendenz auf mit Wintergetreide bepflanzten Flächen, während P. annua in höherer Anzahl auf Flächen gefunden wurde, wo Grasland angelegt worden war. Die Ergebnisse werden in Bezug auf Kulturmethoden und Fruchtwechsel diskutiert und mit den Resultaten anderer Untersuchungen verglichen.