Structural and ultrastructural characteristics of interrenal gland and chromaffin cell of matrinxã, Brycon cephalus Gunther 1869 (Teleostei-Characidae)

This work presents the structure and ultrastructure of the interrenal gland and chromaffin cells, as well as the morphology of the head kidney of Brycon cephalus. The head kidney is composed of fused bilateral lobes located anterior to the swim bladder and ventrolateral to the spinal column. The parenchyma revealed lympho-haematopoietic tissue, melano-macrophage centres, interrenal gland and chromaffin cells. The interrenal gland consisted of cords or strands of cells grouped around the posterior cardinal vein and their branches. Chromaffin cells are found in small groups, closely associated with the interrenal gland and/or under the endothelium of the posterior cardinal vein. So far, the ultrastructural analysis has revealed only one interrenal cell type which contained abundant smooth endoplasmic reticulum and numerous mitochondria with tubulo-vesicular cristae, characteristic of steroid-producing cells. Two types of chromaffin cells were observed. The first type was characterized by the presence of vesicles with round, strongly electron-dense granules, which were eccentrically located. Such cells were interpreted as noradrenaline cells. Meanwhile, cells which contained smaller vesicles and electron-lucent granules, with a small halo separating the granule from the vesicular limiting membrane, were identified as adrenaline cells.     

Pathologic features of abdominal and thoracic paragangliomas in F344/N rats

Seventeen paragangliomas were identified in a retrospective review of 200 NTP/NCI carcinogenicity studies in F344/N rats that served either as control or treated animals. Most tumors were grossly visible and located in the retroperitoneum adjacent to the vertebrae and aorta near the kidneys. Three microscopically detected paragangliomas were found at the base of the heart. Microscopically, neoplastic cells were in nests separated by reticulin fibers and capillaries. Argyrophil granules were in the cytoplasm of the retroperitoneal and mediastinal paravertebral tumors. Dense granules were found in the one tumor examined ultrastructurally. Some tumors had areas of necrosis and tumor emboli were present in the lumen of the abdominal aorta and vena cava adjacent to the tumor with metastases present in pulmonary vessels. The incidence of retroperitoneal neoplasms was 3 times more frequent in male than in female F344/N rats.     

Ultrastructural Changes in Nervous Elements associated with the Granular Cells of the Common Carotid Artery of the Domestic Fowl after Distal Vagal Ganglionectomy

Intramural granular cells of the left and right common carotid artery of the domestic fowl were examined with the electron microscope after left distal vagal ganglionectomy. The vast majority of the nerve fibers and endings associated with the granular cells of the left common carotid artery degenerated rapidly after ispilateral ganglionectomy, indicating that they are derived from the left vagus. On the other hand, left distal vagal ganglionectomy resulted in transformation of the intramural granular cells of the right common carotid artery and the few nervous elements associated with them, into a typical chemoreceptor tissue. This tissue was made up of small granule (60 -120 nm) containing cells associated with many nerve fibers, nerve endings and fenestrated capillaries. The nerve endings were of two types; presumptive afferent endings and adrenergic efferent endings. Both types of endings made synaptic junctions with the granular cells.     

Ultrastructural Aspects of the Prenatal Bovine Ovary Differentiation with a Special Focus on the Interstitial Cells

The aim of this investigation was to study the ultrastructural features during the development of fetal bovine ovaries (crown rump length ranging from 11.4 to 94.0 cm). An interesting observation was the occurrence of big elongated cells containing a variety of electron dense granules and light homogenous vacuoles/bodies. They were located between the stroma cells surrounding the germ cell cord ends, adjacent to the first formed primordial follicles, typically situated near blood vessels. ER alpha and ER beta receptor positive cells could be detected in the same regions by means of immunohistochemistry. Intercellular bridges linked the germ cells nests oogonia. Germ cell cords consisted of centrally located, large, pale oogonia, surrounded by elongated somatic cells with very long cytoplasm extensions. Primordial follicles with flat pale follicular cells could be observed on the inner end of the cords. Extrusions of the outer nuclear membrane could often been recognised in voluminous oocytes.     

A light and electron microscopic study of a normal adrenal medulla and a pheochromocytoma from a horse.

The outer medullary (juxtacortical) zone of a normal equine adrenal gland had columnar chromaffin-positive cells arranged with their long axes perpendicular to fine vascular channels. The deeper medullary regions were composed of smaller irregularly round to polygonal chromaffin positive cells in small packets. Both cell types contained two types of membrane-bound cytoplasmic secretory granules. Osmiophilic granules with a homogeneous core, crenated membrane and narrow submembranous halo predominated in the columnar juxtacortical cells. The rounder, central medullary cells contained predominantly electron dense granules with a wide irregular electron lucent space between an eccentric core and the granule membrane. In contrast, irrespective of cell type or zone, cells from a pheochromocytoma contained only one type of granule similar to that described for the juxtacortical region of the normal equine adrenal medulla. The tumor cells could be classified into three subtypes based on density of granule packing but the granules were morphologically similar in all tumor cells.     

On the Ultrastructure of Mast Cells and Globule Leucocytes in the Common Bile Duct of Cattle Chronically Infected With Fasciola Hepatica

Mast cells and globule leucocytes in the walls of the common bile ducts of seven uninfected slaughtered cows and of five cows chronically infected with Fasciola hepatica were studied by electron microscopy. The mast cells displayed numerous small intracytoplasmic granules, the matrixes of which were either strongly electron-opaque and homogeneous or less dense with a fine-granular ultrastructure. Unattached ribosomes were abundant in the cytoplasm of the cells. Many mast cells in the walls of chronically infected bile ducts were normal-looking while the cells in the subepithelial tissues often showed striking irregularities in the ultrastructure of the granules. Globule leucocytes were most numerous in the surface epithelium and were not connected by desmosomes to the epithelial cells. The nuclei of the globule leucocytes were similar to those in the mast cells except that indentations caused by the globules were more usually seen. The globules were considerably larger than the mast cell granules but bounded by similar agranular capsules. The matrix of most globules was dense and homogeneous while the other globules showed dense reticulate or lamellate structures. The relationship between the mast cell and globule leucocyte in the liver is briefly discussed with reference to recent reports on these cells in the intestinal wall.     

Normal ultrastructure and histochemical characteristics of canine lacrimal glands

Lacrimal glands of 12 dogs free of ocular disease were examined to determine the normal structure of these glands. The glands consisted of tubuloacinar cells that ultrastructurally and histochemically were of a single type of secretory cell in the tubules and possibly 3 types of secretory cells in the acini. The tubular epithelium contained homogenous electron-dense granules that stained as neutral glycoconjugates (periodic acid-Schiff positive and Alcian blue and high iron diamine negative). The predominant acinar cells contained granules of lesser electron density than those of the tubules, and stained as sialomucin (Alcian blue [pH 2.5] and periodic acid-Schiff-positive, and high iron diamine-negative). A second type of acinar cell was in peripheral lobules that ultrastructurally and histochemically appeared like lipid granules (positive with oil red O and osmium tetroxide). Ultrastructurally, a third type of acinar granule was finely granular, electron-lucent, and frequently coalesced. It was not readily apparent whether the latter was an artifact, a stage in the maturation of the sialomucin granules, or a third type of acinar granule. Individual acinar cells usually had a predominance of 1 granule type, but greater than 1 granule type could be found in some cells. The basal surfaces of the acinar, tubular, and ductal cells were incompletely ensheathed by myoepithelial cells. Plasma cells, lymphocytes, mast cells, endothelial cells, fat cells, and Schwann cells composed the cellular elements of the interstitium. Lymphocytes, mast cells, and nerve endings also were found in the parenchyma.     

Cerebral granular cell tumor (myoblastoma) in a dog: case report and literature review.

An infiltrative granular cell tumor (myoblastoma) occurred in the superficial parieto-occipital cortex of an ataxic 12-year-old dog. The neoplasm was characterized by cells with numerous small PAS-positive, diastase-resistant cytoplasmic granules. The neoplasm also had numerous cells with large globular PAS-positive bodies (angulate bodies). Ultrastructurally, the neoplastic cells were characterized by numerous homogenous electron-dense, sharply bounded granules and large pleomorphic, indistinctly bounded granules. The angulate bodies were composed of 8- to 10-nm fibrils, a few of which formed parallel arrays or tubule-like structures. This represents the first report of a granular cell tumor in the central nervous system of the dog.     

Peliosis hepatis-like lesion in aging rats

The incidence of peliosis hepatis-like lesions in two-year-old Charles River-CD Sprague-Dawley rats (Charles River Breeding Laboratories, Wilmington, MA) was almost twice as high in males as females. Blood lakes developed from progressive expansion of sinusoids with destruction of the hepatic cell cords. The endothelial processes of the blood lakes had edematous swelling, vesiculation, and denudation. The microvilli of hepatocytes became swollen, blunted, and sloughed where the endothelial processes were disrupted. Subsequently, the hepatocytes were exposed directly to circulating blood cells and had degenerative changes with accumulation of red blood cells in the cytoplasm. The membrane-bound cysts were observed with the blood lakes and were bounded with atrophic hepatocytes or membranous wall extending to the Disse's space of adjacent hepatocytes. The cysts were filled with proteinaceous fluid, fibrin, and a few red blood cells. The wall of membrane-bound cysts consisted of endothelial processes extending from the endothelial cells of adjacent hepatocytes. The wall appeared to develop from adhesion of endothelial processes surrounding sinusoidal spaces of the hepatocytes following lysis of atrophic hepatocytes.     

肉鸡腹水症心肝肺显微和超微结构研究

运用光镜、电镜技术，观察了肉鸡腹水症自然发病鸡心、肝、肺的显微和超微结构。肺呈弥散性充血和水肿，三级支气管和肺房扩张，平滑肌肥大，软骨样和骨样小结节病灶明显增多，呼吸毛细管上皮细胞内出现大量空泡，肺气－血屏障结构受破坏。心脏肥大，右心扩张，心肌纤维间淤血、水肿，充满大量炎性细胞和结缔组织细胞。心肌变性坏死，肌原纤维断裂，有的横纹消失。肝充血肿大，表面被覆一层灰白色或淡黄色胶冻样物。肝血窦扩张，肝细胞索排列紊乱，肝细胞界限不明显，肝细胞质内的线粒体嵴模糊不清     

恒河猴肾上腺髓质嗜铬细胞的电镜观察

应用透射电镜观察了恒河猴肾上腺髓质含有的 3种嗜铬细胞 ,即明嗜铬细胞、暗嗜铬细胞和小颗粒嗜铬细胞的超微结构特征。明嗜铬细胞卵圆形或略微不规则形 ,电子密度较低 ,胞核圆形 ;胞质内含有大量的分泌颗粒。分泌颗粒多为圆形 ,直径 130～ 35 0 nm,根据其超微结构 ,可分为 2型 : 型颗粒 ,电子密度高 ,核芯呈均质状 ,有的核芯偏于颗粒一侧 ; 型颗粒 ,电子密度中等或较低 ,核芯为细粒状 ,不偏位。暗嗜铬细胞多边形或不规则形 ,电子密度较高 ,胞核不规则形 ;分泌颗粒与明嗜铬细胞相似。小颗粒嗜铬细胞与明嗜铬细胞相似 ,但分泌颗粒较小 ,直径 10 0～ 2 5 0 nm。     

Morphological Study of Mast Cell Localization in the Wall of the Proximal Tubule in the Domestic Swine Kidney

Morphological studies to localize mast cells in the wall of the convoluted and straight parts of the proximal tubules of the domestic swine kidney were performed. Kidney perfusion was carried out in 8-month-old pigs and semi-thin and ultrathin sections were prepared after a routine treatment. A light microscopic study showed that mast cells were not frequently found. Most were localized in the wall of the proximal convoluted tubule, while in the proximal straight tubule wall they were fewer in number. Most of the mast cells were oval in shape, their size being typical for this species, and the granules were reddish in colour. Three types of granule containing an evenly distributed granular-fibrous substance were found by TEM examination: the first type had a single electron-optically dense belt under the membrane; the second showed optically empty spaces between the substance and the cell membrane; the granules from the third type had two parallel dense belts below the granular membrane and were the smallest in size. Some of the granules of the first type were connected with the granular endoplasmic reticulum. A very narrow intercellular area and single desmosome-like junctions were found between the mast cells and the epithelial cells. Protrusions of plasmalemma and granules outside the cells were not established. On the basis of these results and data from the scientific literature, a comparative analysis was carried out. This showed certain differences between the results obtained and previous findings on the morphology of domestic swine mast cells and granules.     

The histology of developing porcine adipose tissue

At each of the following days after conception (45, 60, 75, 90 and 105), pig fetuses were removed from sows representing lean and fat stains. From two additional litters, postnatal pigs were sacrificed at 1, 3, 6, 9, 12, 15, 18 and 21 d. Pelikan dye was injected into fetuses and pigs. The whole of the dorsal subcutaneous tissue, including some underlying muscle, was removed. Tissue was fixed into paraffin blocks or was frozen. Paraffin and frozen sections were stained and examined for stromal-vascular and cellular changes during growth. Organized stromal-vascular changes occurred during a period of adipocyte formation from 45 d gestation until 9 d postnatally. At 45 d gestation, the subcutaneous tissue contained many short unorganized connective tissue fibers. Gradually, these fibers became more organized in a ventral to dorsal and caudal to cranial gradient, so that by 1 d postnatally, they formed complete lobules around all existing fat cell clusters. The presumptive adipose space of the complete lobules contained delicate strands of connective tissue and reacted metachromatically for mucin. Connective tissue around lobules became progressively thinner throughout the remaining postnatal ages. Vascularity of the subcutaneous tissue increased as the stromal became organized. Lipid was not present in the subcutaneous tissue at 45 d gestation, but some deposition was apparent in the inner layer at 60 d. Between 60 d gestation and 9 d postnatally, fat cells filled both subcutaneous layers in a ventral to dorsal formation. Presumptive adipose lobules were the source of adipocytes and capillaries of developing fat cell clusters. Adipocytes from fetuses through 1-d postnatal pigs were multilocular, while unilocular fat cells were first observed at 3 d. At 9 d, multilocular adipocytes were found singly or in groups within unilocular fat cell lobules.     

Ultrastructural studies of the lung of turkeys (Meleagris gallopavo) inoculated intratracheally with Escherichia coli.

To test the hypothesis that walls of air capillaries are a site for Escherichia coli to pass the air-blood barrier, fimbriated and nonfimbriated strains of E. coli were inoculated intratracheally into 18-day-old turkeys. Venous blood was cultured, and turkeys were necropsied from 0.5 to 8 hours post-inoculation. Lungs were processed for histopathology and electron microscopy. E. coli 078 was identified ultrastructurally using rabbit anti-lipopolysaccharide antibody and protein A-colloidal gold. All birds developed bacteremia; there was no significant difference between groups given fimbriated or nonfimbriated bacteria. Bacteria adhered to the plasma membrane of air capillary epithelial cells and were seen within vacuoles of portions of these cells that lined the fornices of air capillaries. Bacteria were also seen in the basement membrane at the basal surface of air capillary epithelial cells and, rarely, in vacuoles of subjacent endothelial cells. Infected granular and non-granular cells that lined air atria were necrotic 4 hours post-inoculation. Bacteria were within the overlying trilaminar substance and between reticular fibers of the interstitial stroma and pleura at 30 minutes post-infection and thereafter. Thus, the pulmonary air capillaries are a site for entrance of E. coli into the pulmonary blood capillaries, but fimbriae play little or no role in passage across the air-blood barrier.     

The influence of restraint immobilization stress on the concentration qf bioamines and cortisol in plasma of Pietrain and Duroc pigs

Forty-five Duroc (recognized as not susceptible to stress) and 34 Pietrain (susceptible to stress) pigs were subjected to immobilization stress in a prone position for 5, 15, 30 and 60 min. Plasma concentrations of epinephrine (E), norepinephrine (NE), dopamine (DA) and cortisol (C) were determined in response to restraint stress. The concentrations of E, NE and DA were different between the two strains of pigs (some significant interactions); the highest response was seen after 5 min of stress. The concentration of plasma C increased with duration of stress and there was a significant interaction between strain of animals and the time of stress. Our data substantiate the use of E, NE, DA and C as indicators of stress in swine as early as 5 min after exposure to the stressor. It is also shown that stress-susceptible Pietrain pigs had higher plasma concentrations of E, NE and DA than Duroc pigs.     

Piecemeal degranulation (PMD) morphology in feline circulating eosinophils

Buffy coat preparation from six cats with 600-4560 circulating eosinophils/microL was collected by either blood centrifugation or sedimentation, fixed in 2.5% glutaraldehyde, post-fixed in either 1% osmium or in 1.5% potassium ferrocyanide-reduced osmium, ultra-sectioned and examined by transmission electron microscopy. Ultrastructural changes of piecemeal degranulation (PMD), which is a mechanism of eosinophil granule contents release indicative of eosinophil activation, were observed in specific granules from all the samples examined. The spectrum of PMD included coarsening of the granule matrix, budding vesicles, fragmented granule cores and lucent granules. The number of presumably activated eosinophils with ultrastructural evidence of PMD did not correlate with the level of eosinophilia. The lack of correlation suggested that, analogously with humans, blood eosinophil count might not represent the best criterion to evaluate the contribution of eosinophils to tissue damage in certain feline eosinophil-associated diseases.     

Evaluation of ultrastructural changes associated with encephalomyocarditis virus in the myocardium of experimentally infected piglets

OBJECTIVE: To evaluate the ultrastructural changes and localization of encephalomyocarditis virus (EMCV) and viral pathogenesis in the myocardium of experimentally infected piglets. ANIMALS: Eight 20-day-old piglets. PROCEDURE: Six piglets were inoculated oronasally with 5 ml (10(6) median tissue culture infective dose/ml) of EMCV suspension, and 2 were used as uninfected controls. Piglets were euthanatized or died between postinoculation days 1 and 3. Samples of heart tissue from all piglets were evaluated histologically, by virus isolation, and by use of immunohistochemistry and electron microscopy. RESULTS: All infected piglets had gross or microscopic lesions of interstitial myocarditis. immunohistochemically, EMCV antigen was detected in the cytoplasm of cardiac muscle cells, Purkinje fibers, and endothelial cells and in the nucleus of cardiac muscle cells and Purkinje fibers. Ultrastructural lesions were characterized by degeneration and necrosis of cardiac muscle cells and Purkinje fibers. Virus was present intracytoplasmically in cardiac muscle cells, Purkinje fibers, and endothelial cells of capillaries and intranuclearly in cardiac muscle cells. The cell membranes of the Purkinje fibers and endothelial cells had distinct protrusions that contained virus particles. In control piglets, no lesions were found, and no EMCV antigen was detected. CONCLUSIONS: Localization of EMCV intracytoplasmically or intranuclearly in various myocardial cells may well reflect the sites of viral proliferation. The presence of virus particles in cell membrane protrusions and in vacuoles within the lumen of capillaries indicates that virus is released not only by disintegration of the host cell but also via exocytosis.     

The Fine Structure of Mast Cells in the Normal Bovine Mammary Gland

The mast cells from the mammary gland of the cow greatly resemble the mast cells of man and small laboratory animals. However, certain ultrastructural differences are found in the mast cell granules. These granules are divided into four different types according to their morphology. All contain a granular material of varying fineness, bounded by a membrane. In addition a fibrous or crystalline part is found in some granules, while in others a large light vacuole can be seen. All the granules are surrounded by a unit membrane.     

苦白石颗粒治疗仔猪白痢实验性临床试验

为评价苦白石颗粒对仔猪白痢的治疗效果,选取85头7日龄~21日龄自然患白痢的仔猪进行临床试验研究。设苦白石颗粒高、中、低剂量组,苦参止痢颗粒组,感染对照组和空白对照组。各试验组病例于用药前进行肠道致病性病原菌的分离鉴定,开始给药及连续给药5 d后,根据症候分级标准和疗效判断标准,观察、记录猪的临床症状和体重。结果显示,从25份检测样品中分离出23株大肠埃希菌,其中2株O157、2株O55和1株O44,对小鼠有致病力;用药5 d后,苦白石颗粒高、中、低剂量组和苦参止痢颗粒药物对照组仔猪的症候积分均显著低于感染对照组(P<0.05),与空白对照组差异不显著(P>0.05);苦白石颗粒高、中、低剂量组和苦参止痢颗粒药物对照组仔猪的平均增重显著高于感染对照组(P<0.05),中剂量组仔猪的平均增重显著高于空白对照组(P<0.05);苦白石颗粒高、中剂量组的治愈率为85%,低剂量组治愈率为80%,均高于苦参止痢颗粒的75%。结果表明,苦白石颗粒中剂量组对仔猪白痢具有较好的治疗效果。     

The guinea fowl spleen at embryonic and post-hatch periods

The spleen of the guinea fowl was bean-shaped but without a dented hilus. It is supplied by three short arteries that came from the ventral surface, two on the cranial end and one at the caudal end of the organ. The whole organ had a thin but tough capsule covering the outer surface except at the point of entry of the blood vessels. By day 18 of incubation, the spleen had a thin but well-defined capsule and internal to this been complete network of sinusoids filled with erythrocytes, lymphocytes and granulocytes. By day 19, dark and light staining zones, which could be termed red and white pulps, had appeared. By day 20, the granulocytes with a lot of granules within their cytoplasm, had become the biggest-sized cells in the spleen. At day 21, arteries and veins were noticed clearly in the spleen and many lymphocytes, few granulocytes and reticular cells surrounded these. Red pulp with its sinusoids was now distinct. A giant cell containing three nuclei was seen within the red pulp. At day 1 post-hatch, the capsule was at its greatest thickness so far and muscle cells were seen at the inner most part of the capsule. Granulocytes that had been a constant feature suddenly disappeared. At day 5, the small lymphocytes had dominated the large and medium-sized ones. By 2 weeks, the red and white pulps were virtually equal in distribution but by 3 weeks, the red pulp was convincingly greater. By 7 weeks, plasma cells had appeared in the peripheral splenic cords. Monocytes were observed in the sinusoids. Two germinal centres were identified for the first time in week 13 post-hatch.