禽类输卵管精子腺组织学与组织化学研究

采用解剖学、组织学及组织化学方法,观察了鸡、鸭、鹅、鹌鹑的输卵管精子腺形态学特点。结果表明,禽类输卵管精子腺是由单层柱状上皮或锥形细胞围绕而成的单管状腺,分布于黏膜固有层内;含输卵管精子腺的环状黏膜带的宽度因输卵管的机能状态及种类不同存在差异;鸡、鹌鹑和鹅的输卵管精子腺细胞,在产卵期和休止期均呈过碘酸雪夫染色(PAS)阳性反应,而鸭呈PAS阴性反应;产卵期和休止期鸡精子腺细胞,均呈脂肪染色强阳性反应,而鸭、鹅、鹌鹑的精子腺细胞呈阴性反应。     

Bovine nasal granuloma. Gross and microscopic lesions.

The anterior nasal mucosa of 21 cattle had small closely-packed polypoid nodules. These had a distribution pattern similar to that of inhaled particles. Acute inflammatory changes consisting of eosinophil infiltration, mast cell and globule leucocyte hyperplasia, and oedema were frequent in the epithelium, terminal gland ducts and adjacent lamina propria. Epithelium over nodules was metaplastic to non-keratinising stratified squamous, whilst epithelium of terminal gland ducts was metaplastic to mucus-secreting pseudostratified columnar. Focal accumulation of granulation tissue between gland ducts caused herniations of the superficial lamina propria to form the nodules.     

雌性空怀双峰驼生殖道的形态结构

应用组织学方法观察了雌性空怀双峰驼生殖道的形态结构。结果显示，双峰驼生殖道的基本结构与其他哺乳动物相似，但微细结构有差异。双峰驼输卵管粘膜皱襞极其发达，分支多而呈复杂的网状迷路。皱襞基部的迷路酷似固有膜而存在腺体，迷路网格内常见细胞团块。虽然双峰驼怀孕时胎儿位于左侧子宫角，但左、右子宫角以及子宫体的组织结构基本相同。子宫内膜无肉阜，上皮下陷于固有膜内，形成大量长而弯曲的单管状腺。子宫颈固有膜浅层分布有许多小腺体，深层分布有成群的较大腺体。这些腺体为分支管状腺，腺上皮PAS强阳性。阴道粘膜上皮为复层上皮。从输卵管到阴道，粘膜上皮主要为单层柱状上皮，由纤毛细胞和分泌细胞组成，局部可见假复层柱状纤毛上皮。纤毛细胞由前向后逐渐减少，但在子宫颈仍可见到。粘膜上皮和腺上皮内夹有许多淋巴细胞或中性粒细胞，后段局部甚至见到这些免疫细胞浸润于上皮细胞间。固有膜内分布有大量淋巴细胞、中性粒细胞、肥大细胞、浆细胞和巨噬细胞，有时出现淋巴滤泡。     

牦牛皱胃组织结构及黏膜免疫相关细胞研究

为揭示牦牛皱胃组织结构和黏膜免疫相关细胞的分布与数量变化的规律,采用组织化学法、图像分析法及透射电镜技术,对牦牛皱胃组织结构及上皮内淋巴细胞、浆细胞和肥大细胞变化进行了研究.结果表明:牦牛皱胃胃壁由黏膜层、黏膜下层、肌层和浆膜构成.皱胃幽门腺区胃小凹深度最深、腺体最长、肌层最厚;3个腺区肌层厚度、腺体长度之间差异极显著(P＜0.01);幽门腺区与胃底腺区、贲门腺区之间胃小凹差异极显著(P＜0.01),胃底腺区与贲门腺区之间差异不显著(P＞0.05).牦牛皱胃黏膜上皮内淋巴细胞数量和浆细胞数量,3个腺区之间差异不显著(P＞0.05);肥大细胞数量以胃底腺区最多,幽门腺区最少,两者之间差异极显著(P＜0.01),贲门腺区与胃底腺区和幽门腺区之间差异不显著(P＞0.05).皱胃各腺区固有层中均有大量的弥散淋巴细胞和孤立淋巴小结.电镜观察表明,胃小凹柱状上皮细胞排列紧密.幽门腺区固有层中有大量的黏液细胞,黏液细胞呈高柱状或锥体状,核位于基底部,在细胞顶端常聚集有较多的电子密度较高的颗粒.胃底腺区和贲门腺区有大量的壁细胞和主细胞.牦牛皱胃的组织结构和其他反刍动物基本相似,但各层有其明显特点.牦牛皱胃各腺区固有层中均有大量弥散淋巴细胞和孤立淋巴小结,使牦牛皱胃具有比其他反刍动物更强的黏膜免疫功能.     

Characterization of the gastric immune response in cheetahs (Acinonyx jubatus) with Helicobacter-associated gastritis

Captive cheetahs have an unusually severe progressive gastritis that is not present in wild cheetahs infected with the same strains of Helicobacter. This gastritis, when severe, has florid lymphocyte and plasma cell infiltrates in the epithelium and lamina propria with gland destruction, parietal cell loss, and, in some cases, lymphoid follicles. The local gastric immune response was characterized by immunohistochemistry in 21 cheetahs with varying degrees of gastritis. The character of the response was similar among types of gastritis except that cheetahs with severe gastritis had increased numbers (up to 70%) of lamina proprial CD79a+CD21- B cells. CD3+CD4+ T cells were present in the lamina propria, and CD3+CD8α+ T cells were within the glandular epithelium. Lymphoid aggregates had follicular differentiation with a central core of CD79a+/CD45R+ B cells and with an outer zone of CD3+ T cells that expressed both CD4 and CD8 antigens. MHC II antigens were diffusely expressed throughout the glandular and superficial epithelium. No cheetah had evidence of autoantibodies against the gastric mucosa when gastric samples from 30 cheetahs with different degrees of gastritis were incubated with autologous and heterologous serum. These findings indicate that T-cell distribution in cheetahs is qualitatively similar to that in other species infected with Helicobacter but that large numbers of lamina propria activated B cells and plasma cells did distinguish cheetahs with severe gastritis. Further research is needed to determine whether alterations in the Th1:Th2 balance are the cause of this more plasmacytic response in some cheetahs.     

Ultrastructure of the Uterotubal Junction in Preovulatory Pigs

The ultrastructure of the surface epithelia from the uterotubal junction (UTJ), and the adjacent tubal isthmic and endometrial regions, was studied in preovulatory oestrus gilts, either unmated or inseminated 12 h before with fresh boar semen. The simple columnar epithelium of the UTJ consisted of non-ciliated (secretory) and ciliated cells. Secretory vesicles occurred in the secretory cells, especially in inseminated gilts. Lymphocytes, monocytes and macrophages were found dispersed basally among the epithelial cells. Phagocytosis of epithelial cells undergoing apoptosis was seen throughout the UTJ at oestrus, increasing after insemination. Neutrophilic granulocytes were found in the lamina propria of the uterine component of the UTJ, but only occasionally in the epithelium. After insemination, neutrophils invaded the uterine epithelium, to actively participate in intraepithelial phagocytosis or move into the lumen, engulfing spermatozoa. Neutrophils were absent from the UTJ proper and the isthmic epithelium, irrespective of the presence of spermatozoa in the lumen. Those spermatozoa in the uterine lumen that escaped phagocytosis had severely damaged plasma membranes, whereas those in the UTJ proper--concentrated towards the deep furrows of the diverticulae--mostly showed normal sperm ultrastructure.     

Immune cell populations within the duodenal mucosa of dogs with enteropathies

The mucosal immune system may play a critical role in the pathogenesis of small intestinal enteropathies. The aim of the current study was to assess mucosal immune cell populations in dogs with inflammatory bowel disease (IBD), idiopathic antibiotic-responsive diarrhea (ARD), and adverse reactions to food (FR). Endoscopic biopsies were performed of the duodenum of dogs with these conditions and from a group of dogs without enteric disease. Additional control samples were collected after death from other dogs that did not have evidence of enteric disease. Immunohistochemistry and computer-aided morphometry were used to assess the distribution of immune cell subsets in both lamina propria and intestinal epithelium. Compared with controls, dogs with ARD had increased numbers of lamina propria immunoglobulin (Ig) A- plasma cells and CD4+ cells. More marked alterations were noted in dogs with IBD, with significant increases in lamina propria IgG+ plasma cells, T cells (CD3+), CD4+ cells, macrophages, and neutrophils, but with reduced mast cell numbers. Increased intraepithelial CD3+ T cells were also present in the dogs with IBD, compared with controls. However, lamina propria and epithelial populations were unaltered in dogs with FR when compared with controls. The altered mucosal immune cell populations observed in dogs with ARD or IBD may reflect an underlying immunologic pathogenesis in these disorders.     

贝氏莫尼茨绦虫感染绵羊对小肠局部黏膜淋巴组织的影响

为了研究贝氏莫尼茨绦虫自然感染绵羊对小肠黏膜免疫组织的影响,分别从宏观、微观及亚微观水平对自然感染贝氏莫尼茨绦虫的成年绵羊(感染组)肠道进行了细致地观察,并与正常成年绵羊(正常组)进行了比较.结果显示,感染组肠道所见虫体平均长度为1.5m,头节主要吸附在空肠淋巴集结分布丰富的部位,一般寄生数量为1～2条.眼观,虫体寄生部位黏膜增厚,表面有大量灰白色黏液附着,其间可见点状出血.镜下,局部黏膜上皮脱落,而在完整的黏膜上皮处,其上皮细胞、上皮内淋巴细胞、杯状细胞的数量都明显增多;固有层内毛细血管充血,淋巴细胞、浆细胞、弥散淋巴组织以及肠腺杯状细胞均有不同程度的增生,头节寄生处部分肠腺坏死;黏膜下层淋巴小结、淋巴集结显著增生,部分增生凸入固有层形成新的圆顶区;固有层与黏膜下层以及黏膜肌层可见大量嗜酸性粒细胞浸润.扫描电镜下,感染组肠黏膜上皮脱落;贝氏莫尼茨绦虫头节呈椭球状,有4个吸盘,无顶突,小沟,表面覆盖一层致密的微绒毛.研究结果表明,肠黏膜增厚,主要是局部黏膜免疫相关细胞在寄生虫虫体表面覆盖的微绒毛的不断刺激下,机体抗感染自身组织增生所致.成年绵羊对抗贝氏莫尼茨绦虫的感染可能是通过黏膜免疫相关组织增生来加强局部免疫力而实现的.     

Ultrastructure of plasma cells in harderian gland of laying hens

Ultrastructure of plasma cells in Harderian gland was investigated using the transmission electron microscopy. For this research, we examined the glands of 32 laying hens collected at 1, 7, 20 and 40 days and 4, 6, 8 and 12 months of the birds' ages. The research showed that the stroma of the gland contains a large number of lymphocytes and plasma cells. Most of the plasma cells are mature, but morphologically do not show productive activity. Only some individual plasma cells, situated under the secretory epithelium of primary and secondary ducts, have extremely dilated cisternae of rough endoplasmic reticulum which contain moderately dense, granular material. The morphology of these cells indicates that they are in active stage of immunoglobulin production. Also, we identified plasma cells with two types of Russell bodies. One type of these bodies was small, round or oval, while the other had irregular, angular shape. It was noted that one plasma cell never contains both type of Russell bodies at the same time. These cells were often affected by apoptosis. Among them, in deeper part of the stroma, were situated the small plasmablast cells.     

Ultrastructural Features of the Bovine Cecal Mucosa

The cecal surface epithelium of cattle was lined entirely by columnar cells except near the openings of the glands where a few partially depleted goblet cells were encountered. Surface columnar cells with pale cytoplasm, indented (sometimes dome-shaped) apical border and irregular microvilli, were also found near the gland orifices. Surface columnar cells -near the openings of the glands contained large cytoplasmic vacuoles and lysosomal-like bodies. Near the extrusion zone, however, the columnar cells contained highly indented and apically displaced nuclei. The glands were usually long and straight and lined by an epithelium concisting mainly of undifferentiated and goblet cells. There were few entero-endocrine and non-epithelial cells (intra-epithelial lymphocytes and globule leukocytes). Paneth cells were absent. The undifferentiated cells contained many free ribosomes and apical secretory granules. Some of these cells were undergoing mitotic division. Goblet cells exhibited a typical brandy-glass appearance and showed dark and light mucigenous granules. Endocrine cells with polymorphic secretory granules and cells with more uniform secretory granules were identified in the basal part of the epithelium. Globule leukocytes and intra-epithelial lymphocytes were usually encountered near the basal part of the epithelium. The lamina propria was highly cellular. It contained many plasma cells, mast cells and small lymphocytes, and few eosinophils, neutrophils and globule leukocytes. Some of the plasma cells contained large, dense Russell bodies within the cisternae of the rough-surfaced endoplasmic reticulum. The neutrophils displayed distinct populations of small and large cytoplasmic granules. Some of the eosinophilic granules showed narrow crystalline cores. Large lymphocytes were found in the lamina propria, but occurred less frequently than small lymphocytes.     

Morphological Studies on the Harderian Gland in the Ostrich (Struthio camelus domesticus) on the Embryonic and Post‐natal Period

The present investigation was performed on 50 ostriches from 28th day of incubation until the 7th month of life. The morphological (morphometric, histological, histometric and histochemical) studies were conducted. Tissue sections were stained with haematoxylin–eosin, methyl green‐pyronin Y, periodic acid–Schiff, alcian blue pH 2.5, aldehyde fuchsin and Hale's dialyzed iron studies. The Harderian gland becomes macroscopically visible on the 28th day of incubation. It is situated in the ventronasal angle of the orbit near inter‐orbital septum, between medial rectus muscle, pyramidal and ventral oblique muscles. The Harderian gland of ostrich is a tubulo‐acinar gland. The acini were composed of tall conical cells which formed a small lumen and were surrounded by myoepithelial cells. These cells had a granular basophilic, vacuolated cytoplasm. Each of the lobes has a system of complex branching ducts – tertiary, secondary and primary. In the III of research group (3rd week of life), the presence of few plasma cells was demonstrated, which were located within acini and tertiary and secondary ducts, whereas the biggest concentration of plasma cells was observed in group IV of research tissue (4th month of life). The dark cells were observed first time in main ducts 72 h after hatching of nestlings (group II). The morphometric and histometric studies showed that the most intensive growth of Harderian gland occurred between the third week and the seventh month of birds' life. The histochemical study indicated the presence of neutral and acidic mucins, glycoproteins and carboxylated acid mucopolysaccharides.     

Species-specific differences of the avian oesophagus: Histological and Ultrastructural study

The oesophagus is a muscular tube comprised of cervical and thoracic regions. Several studies have clarified the histological structure of the oesophagus. However, its histoarchitecture in relation to variable dietary habits of each species is still unclear. In the current study, 21 pigeons, cattle egrets and ducks, n = 7, each was used. Macroscopically, the oesophagus of cattle egrets either the cervical or thoracic parts was the longest among the pigeons and ducks. Histologically, the oesophagus comprised of four distinct tunicae: mucosa, propria submucosa, musculosa and adventitia or serosa. A great structural variation in these layers among the three investigated species was recorded. In the cervical oesophagus of pigeons, the superficial squamous cells showed perinuclear halo zone, the propria submucosa was characteristically lacked any gland. Moreover, its musculosa was very thick. On the other hand, the intraepithelial glands were characteristically distributed along the whole length of the cattle egret’s oesophagus. Interestingly, the cervical esophagus of the ducks showed submucosal associated lymphatic tissue; diffuse and nodular Ultrastructurally, the oesophageal glands showed secretory granules of variable electron densities, electron - lucent in the pigeons and ducks and electron - dense in the cattle egrets.     

Enterocecocolitis associated with intraepithelial Campylobacter-like bacteria in rabbits (Oryctolagus cuniculus)

We examined 28 suckling, weanling, and young adult rabbits with lethargy, inappetence, and mucinous, semifluid feces. Sixteen of the rabbits had intestinal lesions. In eight of these rabbits, the primary changes were multifocal to diffuse epithelial proliferation and accumulation of lymphocytes, macrophages, or both in the lamina propria of the small intestine, cecum, and sacculated colon. In two of these rabbits, the accumulation of macrophages in the lamina propria was extensive. The other eight rabbits had erosive and suppurative cecocolitis, and four of the rabbits with proliferative lesions also had suppurative cecocolitis. In Warthin-Starry-stained sections of affected intestine, curved or spiral bacteria were visible within degenerated or hyperplastic epithelium, in luminal exudate, or in both. Such organisms were sparse or not found in the other 12 rabbits, which did not have intestinal lesions. The bacteria ultrastructurally resembled intraepithelial Campylobacter-like bacteria previously observed in proliferative enteritis in a variety of species and in acute typhlitis in young rabbits. In immunofluorescence tests, Campylobacter-like bacteria in epithelial cells, crypt lumina, and in luminal exudates in both proliferative and erosive lesions bound monoclonal antibodies and polyclonal antisera prepared against intracellular bacteria found in proliferative enteritis in pigs, hamsters, and ferrets. These observations indicate that a condition similar to proliferative enteritis of swine, hamsters, and other species also occurs in laboratory rabbits.     

Immunohistochemical study of the local humoral immune system of the equine respiratory mucosa

An indirect immunoperoxidase technique was used to demonstrate both free immunoglobulin and immunoglobulin-containing plasma cells of IgG, IgA, and IgM classes in the mucosa of the equine respiratory tract. IgA-producing plasma cells predominated in the upper airways, whereas IgG-producing cells predominated in the lower respiratory tract. IgM-secreting cells were uncommon, but present in their highest numbers in the nasopharynx. Plasma cells specific for all of the immunoglobulin classes were identified in the surface epithelium, lamina propria connective tissue, glandular tissue and organised lymphoid tissue. The surface epithelium stained strongly for free IgA and IgM, but weakly for IgG, whereas glandular cells and the lamina propria connective tissue stained most strongly for IgG.     

Local immunity of the respiratory mucosal system in chickens and turkeys

This review article presents fundamental mechanisms of the local mucosal immunity in selected regions of the respiratory tract in healthy birds and in some pathological conditions. The respiratory system, whose mucosa come into direct contact with microorganisms contaminating inhaled air, has some associated structures, such as Harderian gland (HG), conjunctive-associated lymphoid tissue (CALT) and paranasal glands (PG), whose participation in local mechanisms of the mucosal immunity has been corroborated by numerous scientific studies. The nasal mucosa, with structured clusters of lymphoid tissue (NALT - nasal-associated lymphoid tissue) is the first to come into contact with microorganisms which contaminate inhaled air. Lymphoid nodules, made up of B cells with frequently developed germinal centres (GC), surrounded by a coat of CD4+ cells, are the major NALT structures in chickens, whereas CD8+ cells are situated in the epithelium and in the lamina propria of the nasal cavity mucosa. Studies into respiratory system infections (e.g. Mycoplasma gallisepticum) have shown the reactivity of the tracheal mucosa to infection, despite a lack of essential lymphoid tissue. Bronchus-associated lymphoid tissue (BALT) takes part in bronchial immune processes and its structure, topography and ability to perform defensive function in birds is largely age-dependent. Mature BALT is covered by a delicate layer of epithelial cells, called follicle-associated epithelium (FAE). Germinal centres (GC), surrounded by CD4+ cells are developed in most mature BALT nodules, while CD8+ lymphocytes are dispersed among lymphoid nodules and in the epithelium, and they are rarely present in GC. Macrophages make up the first line of defence mechanisms through which the host rapidly responds to microorganisms and their products in the respiratory mucosal system. Another very important element are polymorphonuclear cells, with heterophils being the most important of them. Phagocytic cells obtained from lung lavages in birds are referred to as FARM (free avian respiratory macrophages). Their number in chickens and turkeys is estimated to be 20 times lower than that in mice and rats, which indicates a deficit in the first-line of defence in the birds' respiratory system. There are numerous B cells and antibody secreting cells (ASC) present throughout the respiratory system in birds. Their role comes down to perform antigen-specific protection by producing antibodies (IgM, IgY or IgA class) as a result of contact with pathogenic factors.     

胶质纤维酸性蛋白在黄羽肉鸡肠道中的分布研究

本研究旨在探究胶质纤维酸性蛋白（glial fibrillary acidic protein,GFAP）在黄羽肉鸡肠道中的分布规律。使用免疫组织化学SABC-AP法,观察鸡肠道中GFAP的分布规律。结果显示,GFAP在鸡小肠黏膜上皮、小肠腺细胞腔面、小肠黏膜下神经丛和肌间神经丛及其血管壁周围均呈强阳性表达,在黏膜固有膜上呈阳性表达;GFAP在鸡大肠黏膜上皮、大肠腺中呈阳性表达,在大肠黏膜下神经丛和肌间神经丛均呈强阳性表达。GFAP是肠神经胶质细胞的特异性标记物之一,观察其在鸡肠道的分布特征有助于阐明肠神经胶质细胞在肠道各段的分布规律,为研究鸡肠神经胶质细胞的功能提供形态学依据。     

Study on the Distribution of Glial Fibrillary Acidic Protein in Intestine of Yellow Feather Broiler

The experiment was conducted to explore the distribution of glial fibrillary acidic protein (GFAP) in Yellow feather broiler,and to investigate the morphological characteristics of glial cells of chicken. The distribution of GFAP was studied by immunohistochemistry SABC-AP method. The results showed that GFAP were expressed strong positively in chicken small intestinal mucosa epithelium, intestinal gland cell cavity surface, submucosal plexus and myenteric plexus; The expressions of GFAP were positive in the mucosal lamina propria and myenteric nerve plexus around the blood vessel; In avian escherichia sticky epithelial membrane, colorectal adenocarcinoma,GFAP were expressed positively, and the expressions were strong positive in mucosa epithelium, submucosal plexus and myenteric plexus. GFAP was one of the specific marker of enteric glial cells, and the observation of distribution of GFAP in chicken intestinal tract was help for elucidating the enteric glial cells in the distribution of the intestine and providing the morphological basis for the study of chicken glial cell function.     

Morphogenesis of the Epithelium and the Lamina Propria of the Rumen in Bovine Fetuses and Neonates

Developmental changes in the mucous membrane of the rumen in bovine fetuses were observed by scanning electron microscopy (SEM). The ruminal epitheliums were obtained from 20 bovine fetuses and 4 bovine neonates. The samples were divided into 3 groups. Group 1 was examined in the epithelial surface by SEM. Group 2 was examined in the surface of the lamina propria and the reverse face of the epithelium by SEM, after having separate the epithelium from the lamina propria by Scallata's PBS-EDTA method. Group 3 was examined in histological aspect.
The ruminal papillae appeared first in early in the 5th month of gestation. On the other hand, the papillae of the lamina propria appeared first in early 4th month or late 4th month of gestation. It seemed that the formation of papillae in the lamina propria always preceded that of ruminal papillae. Meanwhile, some epithelial cells were exfoliated from the ruminal surface cells during late 4th month to early 5th month of gestation. Ruminal surface cells came to have keratohyaline granules from the 5th month of gestation onward.     

Flow cytometric analysis of canine colonic mucosal lymphocytes from endoscopically obtained biopsy specimens

OBJECTIVE: To validate use of canine colonic biopsy specimens obtained via endoscopy as a source of mucosal lymphocytes (ML) for flow cytometric analysis. SAMPLE POPULATION: Mucosal biopsy specimens from 10 adult dogs. PROCEDURE: Mucosal lymphocyte subsets obtained from excised colon were compared with ML subsets obtained from biopsy specimens obtained by use of an endoscopic forceps (6 dogs). Endoscopic colonic biopsy specimens from 4 other dogs were used to define whether obtained ML were predominantly of intraepithelial or lamina propria origin. Mucosal lymphocytes were isolated and labeled, using commercially available monoclonal antibodies directed against canine cell surface antigens. Lymphocyte subsets (cytotoxic or helper T cells; B cells) were determined by use of flow cytometric analysis. RESULTS: A large number of viable ML was obtained after dissociation of the colonic epithelium from excised colon (45.5 + 21.5 X 10(6)) and endoscopic (7.2+/-3.4 X 10(6)) biopsy specimens. Lymphocyte subsets obtained with both methods were identical for each dog and consisted predominantly of intraepithelial lymphocytes, with some lymphocytes from the lamina propria. Collagenase digestion of excised colon also yielded a large number of viable lymphocytes from the lamina propria (56.7+/-20.4 X 10(6)), but collagenase digestion of endoscopic biopsy specimens was less rewarding. CONCLUSION AND CLINICAL RELEVANCE: A representative sample of viable intraepithelial ML is obtainable from endoscopic biopsy specimens. Flow cytometric analysis, a minimally invasive technique, can be used to study ML of client-owned animals.     

Pathogenesis of sialodacryoadenitis in gnotobiotic rats.

The pathogenesis of sialodacryoadenitis was studied in gnotobiotic CD rats inoculated intranasally with the causal virus. Virus replication was detected sequentially in the nasopharynx, tracheobronchial tree, cervical lymph nodes, submaxillary and parotid salivary glands, exorbital gland, and Harderian gland. Acute rhinitis appeared within 2 days after inoculation, and salivary glands had lesions in 4 days. Early changes in salivary and exorbital glands were characterized by necrosis of ductal epithelium, which rapidly progressed to widespread acinar necrosis, marked inflammation, edema and total effacement of glandular architecture. Harderian glands also had massive necrosis of tubuloalveolar units. Repair in all glands was characterized by marked squamous metaplasia of tubuloalveolar units. Repair in all glands was characterized by marked squamous metaplasia of ducts. Neutralizing and complement-fixing antibodies were detected in 7 days, and there was a concomitant decrease in tissue-virus titers. There was no detectable evidence for hematogenous spread of virus or for retrograde infection by way of major salivary ducts.