Cryopreservation of equine sperm: optimal cooling rates in the presence and absence of cryoprotective agents determined using differential scanning calorimetry.

Optimization of equine sperm cryopreservation protocols requires an understanding of the water permeability characteristics and volumetric shrinkage response during freezing. A cell-shape-independent differential scanning calorimeter (DSC) technique was used to measure the volumetric shrinkage during freezing of equine sperm suspensions at cooling rates of 5 degrees C/min and 20 degrees C/min in the presence and absence of cryoprotective agents (CPAs), i.e., in the Kenney extender and in the lactose-EDTA extender, respectively. The equine sperm was modeled as a cylinder of length 36.5 microm and a radius of 0.66 microm with an osmotically inactive cell volume (V(b)) of 0.6V(o), where V(o) is the isotonic cell volume. Sperm samples were collected using water-insoluble Vaseline in the artificial vagina and slow cooled at < or = 0.3 degrees C/min in an Equitainer-I from 37 degrees C to 4 degrees C. By fitting a model of water transport to the experimentally obtained DSC volumetric shrinkage data, the best-fit membrane permeability parameters (L(pg) and E(Lp)) were determined. The combined best-fit parameters of water transport (at both 5 degrees C/min and 20 degrees C/min) in Kenney extender (absence of CPAs) are L(pg) = 0.02 microm min(-1) atm(-1) and E(Lp) = 32.7 kcal/mol with a goodness-of-fit parameter R(2) = 0.96, and the best-fit parameters in the lactose-EDTA extender (the CPA medium) are L(pg)[cpa] = 0.008 microm min(-1) atm(-1) and E(Lp)[cpa] = 12.1 kcal/mol with R(2) = 0.97. These parameters suggest that the optimal cooling rate for equine sperm is approximately 29 degrees C/min and is approximately 60 degrees C/min in the Kenney extender and in the lactose-EDTA extender. These rates are predicted assuming no intracellular ice formation occurs and that the approximately 5% of initial osmotically active water volume trapped inside the cells at -30 degrees C will form innocuous ice on further cooling. Numerical simulations also showed that in the lactose-EDTA extender, equine sperm trap approximately 3.4% and approximately 7.1% of the intracellular water when cooled at 20 degrees C/min and 100 degrees C/min, respectively. As an independent test of this prediction, the percentage of viable equine sperm was obtained after freezing at 6 different cooling rates (2 degrees C/min, 20 degrees C/min, 50 degrees C/min, 70 degrees C/min, 130 degrees C/min, and 200 degrees C/min) to -80 degrees C in the CPA medium. Sperm viability was essentially constant between 20 degrees C/min and 130 degrees C/min.

Physiological properties of liver, gonads and muscle during maturation of female Atlantic salmon, Salmo salar. Comparison between a control and xenobiotics containing fish feed.

1. Atlantic salmon, Salmo salar, in their 4th year were maintained in a sea-based farm in the Baltic Sea, salinity 0.2-0.4%. The fish were fed a control diet or a diet containing, among the lipid-soluble xenobiotics, 60 parts of dioxin per 10(12) parts of fish oil. 2. In the fish that attained sexual maturity the liver and gonadal wet weight increased, but decreased after stripping of the roe. Vitellogenesis was also apparent as an elevated level of plasma vitellogenin which was higher after than 2 months prior to removal of the roe. 3. In muscle protein content was highest prior to the removal of the roe. RNA content decreased with time. Following the taking of the roe glycogen content and acid proteinase activity were elevated. 4. Comparison between the feeding groups showed, in the fish fed the experimental diet, a higher gonadal wet weight and plasma vitellogenin content, and in muscle, after stripping of the roe, a lower glycogen content and an elevated level of acid proteinase activity.

Viability and vascularization of an expanded buttock island flap in the pig.

In 14 of 16 buttock island flaps, half of which had been expanded within their cranial arterial part before elevation, areas of skin necrosis were noted within the caudal random part. The mean area of necrosis on the expanded side did not differ from that on the control side. In vivo angiograms indicated that the circumflex iliac artery was more tortuous and wider on the expanded side than on the control side. The findings suggest that expanding the arterial part of the flaps has no apparent negative effects on the circulation. The concept of expanding skin to be used as a free flap, so that the size of the flap may fulfill demands in special circumstances, is supported.

Digitized intra-operative video-fluoroscopy cholangiography. An analysis of 100 cases.

Experience is reported of intra-operative fluoroscopy in 100 cholecystectomized patients using bilateral video- and tele-communicating systems between the surgeon and the conducting radiologist. The radiologist's guidance and the surgeon's realtime observation of the intra-operative study together with reduction in the mean operation time constitute the main advantages of this technique.

Adverse reactions to intravascularly administered contrast media.

A hypothesis is formulated about the mechanisms causing adverse reactions to contrast media. Contrast media act in two ways. They stimulate the mast cells to release histamine and leukotrienes, and they inhibit the enzymes which otherwise degrade leukotrienes. Thus individuals, especially those with a history of allergy, are easily exposed to undue amounts of leukotrienes and these are responsible for the adverse reactions.

High mobility group proteins in skeletal muscle of pre- and postsmolt salmon (Salmo salar).

HMG proteins were extracted from whole skeletal muscle of pre- and postsmolt salmon (Salmo salar). The proteins were identified by SDS and acid-urea polyacrylamide gel electrophoresis. Semi-quantitative analysis revealed an increase in the ratio of HMG H6 to F protein and of HMG T to HMG H6 protein in the postsmolt as compared with the presmolt stage of the salmon. The results demonstrate a change in relative amounts of skeletal muscle HMG proteins which was dependent on the developmental stage of the fish.

Renal artery aneurysms. Natural history and prognosis.

Eighty-three patients out of 8,525 undergoing renal angiography during the years 1970-1979 were found to have renal artery aneurysm, which in six patients were bilateral and in 11 multiple. This corresponds to an incidence of almost 1% in this group of patients. Sixty-nine patients were treated conservatively and followed for a mean of 4.3 years. At that time nine patients had died. The cause of death was in no case related to the aneurysm. None of the 60 living patients had symptoms which could be related to the aneurysm. Reports of 36,656 autopsies, including most of the sudden deaths occurring in southern Sweden during a ten-year period, were analyzed. Nineteen cases of ruptured arterial aneurysms in the branches of abdominal aorta were found, but in no case were the renal arteries involved. It is concluded that the risk for rupture of a renal artery aneurysm is extremely small. The indications to operate renal artery aneurysms are discussed.

An angiographic study of erection in the dog.

Erections were produced in dogs by stimulating the pudendal, the pelvic and the hypogastric nerves either singly or in combination and angiographic studies were then performed. During an erection an increase in blood flow to the erectile tissue could be demonstrated together with an impaired venous return.

Estimation of renal pelvic volume in free urinary flow and in ureteral stasis. An experimental study in the rabbit.

At urography the radiopacity of the pelvis increases with the product of iodine concentration of the urine and its layer thickness. The layer thickness is proportional to the third root of the volume. Using this knowledge, we estimated the volume of the renal pelvis in rabbits and found it to be proportional to the diuresis up to a level of approximately 0.8 ml per min, after which a maximal dilatation seemed to be reached. By this means, the estimated density of the renal pelvis can be calculated. This model of evaluating urographic contrast agents is thought to be more appropriate than and complementary to the mere determination of urinary iodine concentration.

Electrolytic destruction of lung tissue in the rabbit.

Tissue destruction was produced by electrolysis after insertion of electrodes into the rabbit lung. The anode was the active electrode and the best electrode material was platinum. The lesions formed around the electrode were well demarcated and their size varied in relation to the charge applied. Complications were few and the lesions healed quickly. Tissue injury occurs as the result of chlorine liberation at the anode, the basis for which is chloride ion oxidation.

Effect of interposed skin at Doppler flow estimation at 5 and 10 MHz. With a description of a calibration device.

Flow measurements with high ultrasound frequencies (Doppler technique) can be used at quantitative estimations of flow. A calibrator for Doppler equipments is presented. The effect of skin as interposed material with 10 MHz and 5 MHz is discussed as are limitations in the apparatus itself especially when using 10 MHz ultrasound.

Quantitative flow estimations of arteriovenous fistulas with Doppler and dye-dilution techniques.

The flow in operatively created arteriovenous fistulas of 14 patients was calculated with Doppler and dye-dilution techniques. Good correlation was found between the 2 methods. Differences in the results and future examination techniques are discussed.

Complications at balloon catheter angiography. Experiments in rabbits and dogs.

Overdistension of a balloon catheter may injure an artery and this risk increases with decreasing vessel calibre. Before balloon occlusion an estimation of the calibre of the vessel at a preliminary angiography is recommended.

Transabdominal lymphography after intraperitoneal injection of Rous virus in newborn rats.

Newborn rats were inoculated in the peritoneal cavity with Rous sarcoma virus (Schmidt-Ruppin strain). They were studied lymphographically and histologically after various intervals of time. As a result of lesions of the lymph vessels and nodes, the lymphatic drainage of the peritoneal cavity was increasingly impaired. Pleural effusion developed as a result of leakage through the walls of the lymphatics. The passage through the lymph nodes was blocked and large lymph cysts arose in the mediastinum and retroperitoneally.

A dye-dilution method for the determination of blood flow in Cimino-Brescia arteriovenous fistulae.

In 15 patients with large Cimino-Brescia fistulae, arm blood flow and cardiac output were determined by a dye-dilution technique. The mean blood flow through the arm with the shunt open was 1600 ml per min. On compression of the shunt the appearance time increased by 10 sec and there was a moderate decrease in cardiac output.