The possible use of mitochondrial complementation as an indicator of yield heterosis in breeding hybrid wheat

Summary Nine hybrid wheats and their six parental lines were grown in a field trial at two seed densities. The ADP:0 ratios for mitochondria extracted from the six parental lines and for the appropriate 1:1 mixtures of mitochondria from these parental lines were measured. The percentage additional mitochondrial efficiency of the mixtures over their more efficient parental line was found to be significantly correlated with the percentage yield heterosis of fully restored relatively disease-free hybrids grown at the lower seed density. These results indicate that measurements of mitochondrial complementation may have some value as a first screening of potential parental lines and may thus facilitate the rational choice of suitable material for producing hybrid wheat.     

Rapeseed meal and egg taint: Association with sinapine

1. The “fishy” taint of brown‐shelled eggs from susceptible birds due to the presence of trimethylamine following the feeding of rapeseed meal has been shown to be associated with the presence of sinapine in the rapeseed meal.     

CARDIOPULMONARY PHYSIOLOGY — AS IT RELATES TO THORACIC SURGERY

The supplying of oxygen to tissues, and the removal of gaseous wastes are quickly compromised once the chest has been surgically invaded. Of necessity the expansion of the lungs becomes one of a positive rather than a negative pressure process. Abnormal positioning of lobes of the lungs to facilitate exposure for surgery, reduced rate of respiration, atelectasis due to underinflation as well as diseased areas aggrevate the situation. Return of vascular flow to the heart is impaired by loss of negative pressure in the chest cavity. Blood flow through the pulmonary vasculature is impaired by anything that adds resistence. Life itself is very dependent on the delicate balance between hydrostatic and osmotic pressures within the pulmonary capillaries in order for there to be adequate oxygenization. Retention of CO₂ or undersupply of oxygen to tissues contribute to an acidotic state. This acidosis can accelerate a viscious shock cycle if not controlled. Body temperature must not be allowed to drop excessively without careful monitoring of all vital parameters. Motility of cillia along the respiratory tree is slowed by drop in temperature. Phagacytosis within the alveoli undoubtedly diminishes as the temperature drops or the tissues become dehydrated. The heart and respiratory rates are controlled by many autonomic mechanisms which, if interrupted, may need to be compensated for and which must be returned to body control at the end of surgery. The chest is not an area which should be entered with fear but with much respect for its contents and their functions. The surgeon should keep this well in mind and should thus enter the chest as though it were his own.     

Sleep after exercise

After moderate treadmill exercise, marked decreases in operant responding and in latency to onset of behavioral sleep occurs in cats. The sleep produced is characterized by enhancement of synchronized electroencephalographic activity with suppression of the desynchronized phase. The result is consistent with the theory that a function of synchronized sleep is to facilitate recovery from fatigue.     

Respiratory oxidation by mitochondria from tomatoes at different stages of ripeness

A number of factors in the isolation of good quality mitochondria from tomato fruit wall tissue have been critically examined. Particles from tomatoes at a number of stages during maturation and senescence were isolated and their ability to oxidise succinate, malate and -ketoglutarate tested. In general, oxidation rates of the mitochondria and their respiratory control and ADP to oxygen uptake ratios reached a maximum with incipient ripeness and then declined with the onset of senescence. Thiamine pyrophosphate increased the oxidation rate of malate and -ketoglutarate at all stages and appeared to prevent instances of inhibition probably due to the accumulation of oxaloacetate. Particles from the green side of blotchy fruit had characteristics similar to those from normal fruit at the mature green stage, while the red side yielded particles that were similar to those from evenly coloured overripe fruit. Fruit having the dominant allele Never ripe, which causes extreme slowness in ripening, appeared to have mitochondria comparable in behaviour with those isolated from fruit undergoing normal maturation and senescense.

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Zusammenfassung Eine Reihe von Faktoren, eine gute Qualität von Mitochondrien aus Fruchtschalengeweben von Tomaten zu isolieren, wurde kritisch untersucht. Teilchen von Tomaten einer Reihe von Reife- und Altersstadien wurden isoliert und ihre Fähigkeit geprüft, Succinat, Malat und -Ketoglutarat zu oxidieren.Im allgemeinen erreichen die Oxidationsraten der Mitochondrien und ihre Steuerung der Atmung sowie die ADP/O-Aufnahme-Verhältnisse ein Maximum mit beginnender Reife und nehmen ab mit einsetzendem Alter. Thiaminpyrophosphat erhöht die Oxidationsrate von Malat und -Ketoglutarat in allen Stadien und scheint Fälle von Hemmung zu verhindern, die wahrscheinlich auf eine Anhäufung von Oxalacetat zurückzuführen sind. Teilchen der grünen Seite fleckiger Früchte wiesen Charakteristika auf, die denen normaler Früchte im grünen Reifestadium entsprachen, während die rote Seite Teilchen ergab, die ähnlich denen normaler überreifer Früchte waren. Früchte mit dem dominanten Allel Never ripe, das ein extrem langsames Reifen hervorruft, scheinen Mitochondrien zu besitzen, die in ihren Eigenschaften denen vergleichbar sind, die aus Früchten normaler Reife und von normalen Alter isoliert wurden.

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Resume Un certain nombre de facteurs intervenant dans l'isolement de mitochondries de bonne qualité à partir des tissus de la paroi du fruit de la tomate ont été examinés. Des particules extraites de tomates à différents stades de maturation et de sénescence ont été isolées et leur capacité d'oxyder le succinate, le malate et l'-cétoglutarate a été testée.En général, les vitesses d'oxydation des mitochondries, leur contrôle respiratoire et leur rapport ADP/O fixé atteignent une valeur maximum avec la maturité et puis décroissent avec l'instauration de la sénescence. L'addition de pyrophosphate de thiamine augmente la vitesse d'oxydation du malate et de l'-cétoglutarate à tous les stades et semble empêcher des inhibitions probablement dues à l'accumulation d'oxaloacétate. Des particules isolées de parties vertes de fruits blotchy présentent des caractéristiques similaires à celles extraites à partir de fruits normaux au stade de maturité verte, tandis que le côté rouge fournit des particules semblables à celles provenant des fruits trop mûrs uniformément colorés.Les fruits possédant l'allèle Never Ripe dominant, qui provoque une extrême lenteur dans la maturation, semblent présenter des mitochondries dont le comportement est comparable à celui des mitochondries isolées à partir de fruits subissant une maturation et une sénescence normales.

     

Clinical Techniques: Surgical Removal of Elodontomas in the Black-Tailed Prairie Dog (Cynomys ludovicianus) and Eastern Fox Squirrel (Sciurus niger)

Acquired dental disease and the formation of elodontomas are often diagnosed in sciurids. The formation of the elodontoma may be preceded by a traumatic tooth injury or other initiating factors. The degree of disease severity varies based on individual presentation and the time of detection. Maxillary elodontomas in sciurid species cause airway obstruction that can prove fatal for these obligate nasal-breathing animals. A thorough understanding of rodent dental anatomy and a complete diagnostic workup are required for diagnosis, prognosis, and surgical planning of elodontoma presentations. This article highlights 2 successful surgical techniques for the removal of the maxillary incisors in sciurid patients with almost total occlusion of the nasal passage.     

Effects of the glycoprotein IIb/IIIa antagonist abciximab on thrombus formation and platelet function in cats with arterial injury

An established model of arterial injury was used to evaluate the ability of the glycoprotein (GP) IIb/IIIa antagonist abciximab to inhibit platelet function and deter thrombus formation in cats. The study was a blinded evaluation, with control cats receiving aspirin and placebo and treatment cats receiving aspirin plus abciximab. The group treated with aspirin plus abciximab had significantly (P<.05) less thrombus formation based on a smaller number and frequency of cyclic flow reductions and reduced luminal thrombus area than cats treated with aspirin plus placebo. Abciximab administered in addition to aspirin also resulted in significant (P<.05) inhibition of platelet function based on mucosal bleeding time and change in bleeding time from baseline.     

Femoral venipuncture for collection of multiple blood samples in the nonanesthetized rat

A technique for blood collection via the femoral vein was developed for use in nonanesthetized rats. The technique was useful for single or serial blood collection. Volumes of 0.1 to 1 ml were collected for serum biochemical or venous blood gas determinations. The technique was effective, reproducible, did not require anesthesia, and was less stressful than other methods of blood collection in the rat.