当北极不再是北极

北极在许多人心中意味着遥远、寒冷和神秘，是一个冰天雪地的童话世界。然而，近年来气候变暖和油气田开发对北极带来了很大冲击，当地特有的景观、传统和生活方式随着冰雪的消融在慢慢发生变化。     

Clinical Results Following Nonoperative Management for Rupture of the Cranial Cruciate Ligament in Dogs

Eighty-five dogs were diagnosed as having rupture of the cranial cruciate ligament. They were managed by restriction of activity to leash walks for 3 to 6 weeks, weight loss if indicated, and analgesic medication as needed. Twenty-four of 28 dogs that had a body weight of 15 kg or less (85.7%) were considered to be clinically normal (no lameness and normal range of motion in stifle, 21 dogs) or improved (3 dogs) after an average follow-up period of 36.6 months. Lameness in the remaining four dogs persisted or worsened over an average period of 8.2 months (minimum 6 months), and surgical replacement of the cruciate ligament was performed. Eleven of 57 dogs that had a body weight of 15 kg or greater (19.3%) were classified as normal (4 dogs) or improved (7 dogs) after an average follow-up period of 49.1 months. Lameness in the remaining 46 dogs persisted or worsened over an average period of 10.2 months (minimum 6 months), and surgical replacement of the cruciate ligament was performed.     

THE SCINTIGRAPHIC EVALUATION OF SOLID PHASE GASTRIC EMPTYING IN NORMAL CATS

The gastric emptying half-time of solid food in normal cats was determined using a scintigraphic technique. ^99mTc-sulfur colloid was applied to dry food. Sequential images were acquired post prandial, and the gastric emptying half-time was determined for several different acquisition and processing parameters. Good correlation was found between different acquisition and processing methods, some of which made use of edge detection applications, while others used different views, or number of views from which the gastric emptying half-time was calculated. The mean ± standard deviation, (range) and median of the gastric emptying half-time determined using the geometric mean of total counts in hand-drawn regions of interest from the lateral and ventral images were 2.47 × 0.71, (1.42–3.61) and 2.37 hours respectably.     

Conservative Versus Surgical Management of Gastrointestinal Linear Foreign Bodies in the Cat

Twenty-four cases of gastrointestinal linear foreign bodies (LFB) in cats were reviewed. Nine cats were successfully managed conservatively, with passage of the LFB occurring 1 to 3 days after presentation. Ten cats that were initially managed conservatively were subsequently treated surgically. The decision to operate was based on worsening of clinical signs and failure to pass the LFB. Five cats were initially treated surgically. The cats that were managed successfully via conservative treatment had a shorter duration of clinical signs before presentation, decreased incidence of abdominal pain and palpable intestinal plication, and less severe hematologic abnormalities. Radiographic signs were of little benefit in deciding whether to treat the cats conservatively or surgically. None of the cats died.     

ESTIMATION OF BLADDER VOLUME USING ULTRASONOGRAPHIC DETERMINATION OF CROSS-SECTIONAL AREAS AND LINEAR MEASUREMENTS

The purpose of this study was to determine if ultrasonographic measurement of multiple cross-sectional areas combined with linear dimensions of the bladder could be used as a method of estimating bladder volume in the dog, and, if so, to compare the accuracy of this estimation with that described previously using linear measurements alone. Fifty-two live dogs undergoing investigation for urological disease and 37 fresh canine cadavers were used for bladder volume determination. Maximal length, depth, width, and area were measured from the maximal longitudinal and transverse sonograms in each living animal. In cadavers, the cross-sectional area of the longitudinal section of the bladder was measured at one centimeter intervals, and the measurements were summed. Based on sequential partial regression analysis, the cross-sectional area of the longitudinal section of the bladder and length were the best predictors of actual bladder volume in living animals. However, based on the cadaver experiment, the best predictor of actual bladder volume was summed parasagittal area alone, and, in cadavers, this was a much better predictor of actual bladder volume than the combination of the cross-sectional area of the longitudinal section of the bladder and length. The formula derived in living dogs using the corss-sectional area of the longitudinal section of the bladder and length gave a less accurate estimation of bladder volume than a previously published formula where only linear measurements were used.     

Clinical observations on changes in concentrations of hormones in plasma of two stallions with thermally-induced testicular degeneration

To investigate effects of thermally-induced testicular degeneration on hormonal and seminal parameters in stallions, the scrotum was insulated for 36 hours in two mature (5-year-old mixed breed and 11-year-old Throughbred) stallions. Semen was collected daily for 10 days (DSO) prior to, and at intervals after, scrotal insulation. When DSO determinations were not being made, semen was collected 3 times weekly. Jugular blood samples were collected at 15-minute intervals for 6 hours from each stallion prior to, and at intervals after, scrotal insulation. A mouse interstitial cell testosterone assay was modified to quantify biologic activity of equine luteinizing hormone (BLH) in plasma samples. Immunoactive luteinizing hormone (ILH) and testosterone (T) concentrations were determined in plasma samples by routine RIA procedures. Percentages of progressively motile and morphologically normal spermatozoa began to decrease by 1 to 2 weeks postinsulation, reached nadir values at 3 to 3-1/2 weeks postinsulation, and returned to preinsulation values by 7 weeks postinsulation. Total number of spermatozoa and total number of progressively motile, morphologically normal spermatozoa in ejaculates at DSO returned to normal by 8 weeks postinsulation in stallion 2 and 12 weeks postinsulation in stallion 1. Concentrations of BLH and ILH increased, and while T concentrations decreased, immediately postinsulation. The increase in ILH concentrations was greater than the increase in BLH concentrations, resulting in a decrease in the BLH:ILH (B:I) ratio. Following the peak in LH secretion immediately postinsulation, LH concentrations gradually decreased while T concentrations increased. The B:I ratio was elevated from 1 to 13 weeks postinsulation compared to immediately postinsulation. In addition to changes in spermatozoal quality in ejaculates, stallion response to scrotal insulation included increased secretion of luteinizing hormone and impaired Leydig cell function (as determined by reduced testosterone concentration in circulating plasma). The proportion of biologically active LH secreted in response to thermal testicular injury increased during the recovery phase.