Ultrasonographic findings in dogs and cats with oxalate nephrosis attributed to ethylene glycol intoxication: 15 cases (1984-1988)

Renal ultrasonographic findings in 12 dogs and 3 cats determined to have oxalate nephrosis presumed to be secondary to ethylene glycol intoxication were examined. Ultrasonographic changes varied from mild to marked increases in renal cortical echogenicity. A pattern of greater than normal cortical and medullary echogenicity with persistence of areas of lesser echo intensity at the corticomedullary junction and central medullary regions was observed. This pattern, termed the halo sign, was recognized in 7 dogs and 1 cat concurrent with the development of clinical anuria. Ultrasonographic patterns in these clinical cases were similar to those observed in a previous study of dogs with experimentally induced ethylene glycol nephrosis. Ultrasonographic findings were not considered pathognomonic of ethylene glycol nephrosis. Due to the high death rate reported in the cases surveyed, detection of ultrasonographic changes was considered to warrant a guarded to poor prognosis. Because of the association of the halo sign with anuria, its detection was considered to warrant a grave prognosis.     

MOST DOGS WITH MEDULLARY RIM SIGN ON ULTRASONOGRAPHY HAVE NO DEMONSTRABLE RENAL DYSFUNCTION

The medullary rim sign is a distinct hyperechoic line in the renal medulla parallel to the corticomedullary junction that has been reported in dogs with a variety of renal diseases. To examine the association between medullary rim sign and renal disease, the medical records of thirty-two dogs that had medullary rim sign were reviewed retrospectively. Eighteen dogs (56%) had no evidence of renal dysfunction; 14 (44%) had clinicopathological evidence of renal disease, including 6 (19%) that had hypercalcemic nephropathy. Most dogs (72%) in which medullary rim sign was the only ultrasonographic finding affecting the kidneys had no evidence of renal dysfunction. In contrast, 78% dogs that had medullary rim sign and other renal signs (reduced size, increased medullary echogenicity, and pyelectasia) had renal disease. On the basis of this study, the medullary rim sign appears to be a non-specific ultrasonographic sign; however, the possibility cannot be excluded that is a sentinel sign of subclinical renal disease.     

RENAL MEDULLARY RIM SIGN: ULTRASONOGRAPHIC EVIDENCE OF RENAL DISEASE

An echogenic line in the outer zone of the renal medulla, paralleling the corticomedullary junction is described as the renal medullary rim sign. This renal ultrasonographic change is demonstrated in 4 dogs and 2 cats with a range of renal diseases. The renal medullary rim sign provides additional ultrasonographic criteria indicating primary renal disease in some patients. However the renal medullary rim sign may prove to be a poor correlate for prognosis across the range of differentials present in these clinical patients.     

Prenatal Metanephrogenesis of The Camel: Morphological Evidence of Epithelial–Mesenchymal Interaction

The present investigation examined histogenesis of epithelial, stromal and angiogenic elements of the prenatal camel permanent or metanephric kidney. The primitive metanephros was first observed at the 13‐mm crown vertebral rump length (CVRL) stage as an ovoid structure composed of a centrally located epithelial ureteric bud and peripheral circumscribed masses of undifferentiated mesenchymal cells. The first morphological evidence of glomerulogenesis was observed at the 28‐mm CVRL stage. Developing renal corpuscles became obvious at the 35‐mm CVRL stage. At the 60‐mm CVRL stage, the epithelial renal pelvis gave rise to tubular branches that extended towards the cortical zone. These branches represented the presumptive collecting ducts. Differentiation of renal tubules into the proximal and distal convoluted tubules was observed at the 95‐mm CVRL stage. At the 130‐mm CVRL stage, the renal medulla was clearly delineated into medullary pyramids, which in association with the corresponding cortical caps formed the morphological basis of the renal lobar formation. A gradual nephrogenic decline was noticed from the 940‐mm CVRL on; however, the process of nephrogenesis persisted throughout all the studied foetal stages.     

Early renal ultrasonographic findings in dogs with experimentally induced ethylene glycol nephrosis

Renal ultrasonographic changes were evaluated in 5 dogs administered 10 ml of commercial antifreeze (95% ethylene glycol)/kg of body weight, PO, and in 2 dogs given placebos. Studies were made prior to and after ingestion on an hourly basis over a period of 8 to 10 hours. All dogs were anesthetized immediately after toxin or placebo ingestion for the duration of the study. Renal cortical echogenicity was evaluated in comparison with that of the adjacent liver and spleen. Echogenicity of the renal medulla and definition of the corticomedullary junction were assessed. Within 4 hours after ethylene glycol administration, renal cortical echogenicity of all intoxicated dogs increased from normal to surpass that of liver and approach or equal that of the spleen. Medullary echogenicity in all intoxicated dogs progressively increased over the course of the study, with changes recognized within 5 hours after ethylene glycol administration. An ultrasonographic pattern consisting of nearly equal, marked increase in cortical and medullary echogenicity and relatively hypoechoic corticomedullary junction and central medullary regions was recognized concurrent with the development of anuria in 3 of the 5 intoxicated dogs. Mild, transient increases in cortical and medullary echogenicity were observed in anesthetized control dogs. However, no statistical difference (P less than 0.05) was detected between baseline, peak, and terminal echogenicity values in these dogs. Blood and urine samples were collected hourly from intoxicated dogs to coincide with ultrasonographic studies. Most clinicopathologic values derived from these samples were not statistically different (P less than 0.05) from those reported in a study that used a similar intoxication protocol in nonanesthetized dogs.     

RENAL SONOGRAPHIC MEASUREMENTS IN THE DOG PRECEDING AND FOLLOWING UNILATERAL NEPHRECTOMY

The purpose of this study was to establish sonographic baseline values for normal kidneys initu and to document sonographic changes following unilateral nephrectomy. Normal canine renal measurements were determined sonographically prior to and following unilateral nephrectomy. These included: cortical thickness (cranial, caudal, dorsal, ventral, lateral and medial), medullary measurements (cranial and caudal) and measurements of the renal silhouette (length, height and width). The latter group of measurements was obtained to determine renal volume. Normal parameters were obtained from sixteen healthy dogs prior to nephrectomy; the unilateral nephrectomy group was comprised of eight of these animals, the remaining eight dogs were part of an allo-transplant study.¹ The mean sonographic value for the length of the kidney was 60.3 mm ± 6.4 (n = 26) while the widths and heights were 34.7 ± 3.8 (n = 27) and 27.8 mm ± 3.3 (n = 26) respectively. Renal cortical measurements were found to be smallest dorsally and ventrally on sagittal and transverse sonograms. The largest volumes were the cranial pole on sagittal scans and the lateral pole on the transverse scans. Pearson correlation coefficient for volume resulted in r values of 0.88, 0.78 and 0.72 for length, height and width (n = 25, dif = 24) respectively.     

ULTRASONOGRAPHIC EVALUATION OF RENAL SIZE IN DOGS WITH ACUTE ALLOGRAFT REJECTION

The purpose of this study was to determine the best method to ultrasonographically monitor renal size changes associated with acute allograft rejection in dogs. Qualitative changes in renal cortical and medullary echogenicity were also evaluated, although this was not a major focus of the study. Four unrelated, mixed-breed dogs underwent bilateral nephrectomies and heterotopic renal allograft transplantation. Ultrasound examinations of transplanted kidneys were initiated at 3 days after surgery and continued at 2–3 day intervals until death (38±2 days). Ultrasound measurements of kidney length, width, height, cross-sectional area, and estimated volume were used to assess relative changes in renal size associated with transplantation and rejection. Transplanted kidneys had a rapid increase in volume and cross-sectional area that averaged 103% and 83% above baseline levels, respectively, by 17 days after transplantation. The increased size was attributed to a combination of hypertrophy and acute rejection, the latter of which was confirmed at postmortem. Kidney volume decreased to approximately 35% above baseline volume by day 34 as rejection became more advanced. Qualitative changes associated with rejection included medullary enlargement with decreased echogenicity early in the study, followed by increased cortical thickness and echogenicity with poor cortical medullary definition in the latter stages of the survival period. It was concluded that relative changes in renal allograft size can be easily monitored with ultrasound. In regard to linear measurements, changes in renal width were more pronounced than changes in height or length with acute rejection. Therefore measurements that incorporate the width, namely volume or cross-sectional area, appear to be the most sensitive for monitoring changes in allograft size. Renal cross-sectional area measurements are preferred because they are simple to perform using the automated calculation capability of most newer ultrasound units.     

SONOGRAPHIC AND SCINTIGRAPHIC EVALUATION OF ACUTE RENAL ALLOGRAFT REJECTION IN CATS

The sonographic features of acute renal allograft rejection in humans and dogs are manifested by increase in renal cross-sectional area and reduction in renal cortical blood flow. These changes have not been investigated in cats. The objectives of this study were to evaluate sonographic and scintigraphic changes during acute renal allograft rejection in cats. Eight SPF, intact, adult, male cats received heterotopic renal allotransplantations. Immunosuppressive doses of cyclosporine and prednisolone were administered for 14 days and then discontinued to allow acute allograft rejection to occur. Serial measurements of renal cross-sectional area, resistive index (RI), echogenicity, and glomerular filtration rate (GFR) were performed to evaluate changes during acute rejection. Upon sonographic confirmation of absent diastolic blood flow or a 20% increase in cross-sectional area of the allograft, a nephrectomy and histopathologic evaluation were performed. Acute allograft rejection was confirmed histologically in all cats. Significant increases in renal cross-sectional area (P < 0.001) occurred postoperatively and during rejection. There were no significant changes in RI (P = 0.43) at any time. A subjective increase in medullary echogenicity and a decrease in corticomedullary demarcation were observed in the rejection period. While GFR decreased significantly in the immediate postoperative period (P < 0.001), no further change occurred during rejection (P = 0.42). Changes in RI and GFR do not appear to be sensitive indicators of acute renal allograft rejection in cats. Serial measurements of renal cross-sectional area appear to be a sensitive method for the early diagnosis of allograft rejection in feline renal transplant recipients.     

Development of the Bovine Metanephros

This study presents the gross and light microscopic features of the developing bovine metanephros. Thirty-six specimens, consisting of 19 whole embryos and foetuses, 15 foetal metanephroi, one calf kidney and one cow kidney, were examined. The development of the collecting duct system and nephron induction and formation were similar to those processes described for the human kidney but appeared to follow an accelerated time course. The bovine metanephros by 15–18 weeks gestation, had a well organized internal structure consisting of dilated major calyces, prominent minor calyces and papillae, and a definize cortex and medulla. Nephron induction started as early as 4–6 weeks gestation and was completed around 28 weeks.     

Rodent renal structure differs among species

In the present study, we histologically and morphometrically investigated species differences in renal structure using laboratory rodents (mice, gerbils, hamsters, rats, and guinea pigs). Morphometric parameters were as follows, 1) diameter of the cortical renal corpuscles, 2) diameter of the juxtamedullary renal corpuscles, 3) percentage of the renal corpuscles with a cuboidal parietal layer, 4) number of nuclei in proximal convoluted tubules (PCTs) per unit area of cortex, 5) semi-quantitative score of the periodic acid-Schiff (PAS) -positive granules in PCTs, and 6) semi-quantitative score of the PAS-positive granules in proximal straight tubules (PSTs). Significant species differences were detected for each parameter, and particularly severe differences were observed in the PAS-positive granules of PCTs and PSTs. Granular scores varied among species and sexes. Vacuolar structures that did not stain with PAS or hematoxylin-eosin were observed in the renal proximal tubules. The appearance and localization of these vacuolar structures differed remarkably between species and sexes.     

ULTRASONOGRAPHIC FINDINGS IN ETHYLENE GLYCOL (ANTIFREEZE) POISONING IN A PREGNANT QUEEN AND 4 FETAL KITTENS

A one year old female Siamese-Persian mixed breed cat in late third trimester of pregnancy was presented for anorexia and lethargy. Abdominal radiographs were normal. Abdominal ultrasound revealed markedly increased cortical and moderately increased medullary echogenicity of the maternal kidneys. Cortical echogenicity of all fetal kidneys were similarly increased in echogenicity. Premortem clinicopathologic and postmortem histopathologic findings were indicative of ethylene glycol nephrosis presumably secondary to antifreeze ingestion.     

黄腹角雉肾的解剖和组织形态学观察

采用常规方法对1只人工繁殖的黄腹角雉进行解剖,观察其肾的解剖学特征;并取黄腹角雉的肾脏,制作石蜡组织切片,进行H-E染色和在显微镜下观察其组织形态结构。结果表明,其肾脏表面有极薄的结缔组织包被,被膜的结缔组织深入实质,形成含量较少的小叶间结缔组织,内有淋巴组织和丰富的毛细血管。肾实质主要由大量肾小叶构成,每个肾小叶形似倒梨状,内有许多肾单位,分为皮质部肾单位和髓质部肾单位。但其皮质部和髓质部不如哺乳动物那样界线明显,肾单位数量与体重之比较哺乳动物高。     

Sarcomatoid renal cell carcinoma with scant epithelial components in an Angora cat

CASE HISTORY: A 6-year-old, neutered, female Angora cat presented with a history of lethargy and anorexia for 2 months and a clinically palpable and gradually enlarging, solid mass in the abdominal cavity extending from the last costal arch to the pelvic cavity.

CLINICAL FINDINGS: Examination of the cat revealed jaundice, dehydration and hypothermia. Haematological manifestations included lymphopenia and substantial decrease in haematocrit value. Biochemical analysis of the blood revealed hypoglycaemia, three-fold elevated blood urea nitrogen values, increased level of serum aspartate aminotransferase and increased total bilirubin while the creatinine level was normal. Ultrasonographic examination of the abdomen showed a disrupted and large hypoechoic area around the left kidney. The cat was anaesthetised and the left kidney was removed, but the cat died following surgery.

PATHOLOGICAL FINDINGS: On post-mortem examination, the left kidney was markedly enlarged and both the cortical and medullary parenchyma were replaced by confluent, multilobulated, pale tan-white, firm nodular masses protruding above the capsular surface. Metastasis was not observed. Cytological examination revealed a population of spindle-shaped cells of variable size, with abundant coarse chromatin and occasionally prominent nucleoli. Initial sections of the kidney were indicative of undifferentiated sarcoma confirmed by immunohistochemistry revealing vimentin-positive and cytokeratin-negative results in all tumour tissues. Additional sections showed very small amounts of both cytokeratin-positive and vimentin-positive areas.

DIAGNOSIS: Sarcomatoid renal cell carcinoma (SRCC) with scant epithelial components originating from left kidney.

CLINICAL RELEVANCE: Clinical and pathological features were similar to those of human SRCC, even though there was no evidence of metastases. Immunohistochemistry for vimentin and cytokeratin may be useful for definitive diagnosis of renal cell carcinoma with sarcomatoid differentiation, although staining of sections from several different parts of the tumour may be necessary. When a primary renal tumour is presented, SRCC should be considered as this diagnosis may influence treatment protocols and the clinical outcome.     

AGE AND DIET EFFECTS ON RELATIVE RENAL ECHOGENICITY IN GERIATRIC BITCHES

Under controlled, but varied dietary conditions 35 geriatric, uninephrectomized, spayed Beagle bitches (dogs) observed for 4 years, renal cortical and renal medullary echogenicity was measured relative to hepatic and splenic echogenicity. Regardless of the diet fed, 60-75% of these aged dogs had renal cortical echogenicity less than that of either the liver or spleen across time; 25-35% of these dogs had renal cortical echogenicity equal to that of the liver, but less than that of the spleen across time. Less than 3% of these dogs had renal cortical echogenicity greater than that of the liver, but less than that of the spleen. Only 1 (one) of these dogs had renal cortical echogenicity equal to that of the spleen and that occurred at only one of the 14 chronologic assessments. Therefore, in either mature or aged dogs imaged with 4.0 to 5.0 MHz equipment, the renal cortical echogenicity should be considered normal if it is less than or equal to that of the liver and less than that of the spleen. In 29 dogs imaged with the 4.0/5.0 MHz equipment and 6 dogs imaged with 7.5 MHz equipment, there was no significant diet or individual dog effect. The 7.5 MHz (6 dog) group had significantly higher average cortical echogenicity scores than the 4.0/5.0 MHz (29 dog) group. However, the occurrence of renal cortical echogenicity greater than liver echogenicity was seen in only 5 of 83 samples (approximately 6.0%) made on 6 dogs imaged with 7.5 MHz equipment and only 1 of 375 samples (approximately 0.27%) made on 29 dogs with 4.0/5.0 MHz equipment. With the exception of one occurrence, all dogs had renal medullary echogenicity less than that of the liver or spleen regardless of imaging equipment frequency. The renal medulla was always hypoechoic compared to the cortex.     

神经内分泌细胞在鸭胸腺中的表达特征

应用免疫组化技术并结合图像分析软件研究了β-内啡肽、胃泌素、胰高血糖素、5-羟色胺、血管活性肠肽、神经肽Y、生长抑素细胞在鸭胸腺中的表达特征。结果显示：7种神经内分泌细胞在胸腺中呈强阳性表达;β-内啡肽阳性细胞在皮质部较多,而胃泌素、胰高血糖素、5-羟色胺、血管活性肠肽、神经肽Y、生长抑素阳性细胞在髓质和皮髓质交界区的数量高于皮质部;除胰高血糖素外,其余6种神经内分泌激素在胸腺小体中呈不同程度的阳性反应。本试验结果说明,鸭胸腺不仅是中枢免疫器官,而且具有重要的神经内分泌功能;β-内啡肽阳性细胞在T淋巴细胞的发育中发挥重要作用;胃泌素、胰高血糖素、5-羟色胺、生长抑素、血管活性肠肽、神经肽Y阳性细胞在髓质部和皮髓质交界区的表达有利于其通过内分泌、自分泌或旁分泌方式调节T细胞的发育。同时,也探讨了胸腺小体的功能。     

The biomorphosis of the kidney in swine. 2. Kidney cortex and kidney medulla

Information recorded from structural development of kidney in swine foetuses of different age and in piglets together with functional data has shown that, notwithstanding progressing maturation, the capacity of renal corpuscles and tubules in piglets was less developed than in other species. Milk deficit or insufficient drinking water or medication may be considerable burdens on the kidney of newborn piglets and may cause stress-related damage.     

Morphometrical analysis of sex and strain differences in the mouse nephron.

In the present study, we investigated the sexual dimorphisms, effects of castration and sex hormone treatment, and strain differences in the morphology of mouse kidney by measuring the percentage of renal corpuscles with cuboidal cells in the parietal layer of the glomerular capsule, the diameter of renal corpuscles and the number of nuclei of epithelial cells in the proximal convoluted tubule. In ICR mice, the percentage of renal corpuscles with cuboidal cells and the diameter of renal corpuscles were larger in males than in females, and the numbers of nuclei were lower in males than in females. All of these parameters became similar to those of intact females by orchiectomy, and restored to levels similar to those in intact males after testosterone treatment to orchiectomized males. On the other hand, ovariectomy and estradiol treatment gave no effects to any of these parameters. Similar sexual dimorphisms were observed in BALB/c, C57BL/6, C3H/He and DBA/2 mice as in ICR mice, although the diameter of renal corpuscles was not significantly different between males and females in BALB/c mice. Strain differences were observed in each of these three parameters among the 5 strains. In conclusion, the present study demonstrated sexual dimorphisms, effects of castration and sex hormone treatment, and strain differences in the morphology of mouse kidney by morphometrical analysis.     

磺胺类药物对猪肾脏损害的病理学观察

对14例含有磺胺结晶的猪肾脏用10%中性福尔马林固定,常规石蜡切片技术切片染色,对肾脏进行组织病理学观察。结果显示,皮质区肾小管上皮细胞肿胀变性、髄质区肾小管破坏较为严重,大部分肾小管、集合管上皮细胞脱落、变性坏死,并引起梗阻性肾病,同时,肾小球囊腔扩张、血管球萎缩。结果证实,超剂量或长期使用磺胺类药物会严重损害肾实质,导致肾功能下降甚至肾衰竭。     

Lipid Content of Non-cultured and Cultured Pig Embryo

The objectives of the study were: (i) to work out a precise and efficient method for quantitative analysis of lipid content and (ii) to quantitatively determine the lipid content in non-cultured and cultured pig embryos . The experiment was carried out on pig embryos from zygote to late blastocyst stages produced in vivo and embryos collected at the zygote stage and then cultured in vitro up to blastocyst stage . Embryos were fixed, dehydrated, embedded in epoxy resin and cut into semi-thin sections to analyse the quantity of lipids in fat droplets. Stained sections were then analysed with Cavalieri and point counting methods to evaluate the following stereological parameters of the embryo: total embryo volume – V(e), volume density of cytoplasm per unit volume of embryo – Vv(c,e), volume density of lipid droplets per unit volume of embryo cytoplasm – Vv(fat,c) and total volume of lipid droplets per whole embryo – V(fat). Values of Vv(fat,c) and V(fat) remained unchanged up to the morula stage, but decreased significantly at blastocyst and late blastocyst stages both in cultured and non-cultured embryos. Volume density of lipid droplets per unit volume of embryo cytoplasm and total volume of lipid droplets for cultured embryos showed statistically significant differences between late blastocyst and almost all other stages. Comparisons of Vv(fat,c) in embryos at the same stages of development but differing in origin of embryos (non-cultured or cultured) show that statistically significant differences exist for all analysed stages. In conclusion, differences in lipid content observed in pig embryos were dependent on the developmental stage of the embryo as well as the culture conditions (i.e. cultured and non-cultured embryos at the same stage of development).