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1.
Two strains of the agent of virus pneumonia, were tested for the ability to propagate in 12 types of cell cultures and in chicken embryos. The 5 primary cell cultures used were: swine kidney, lung, bone marrow, testicle, and chicken embryo kidney; and the 7 serial passage cell cultures were: swine kidney, kidney-tumor, testicle, bone-marrow, bovine kidney, and human cervical carcinoma (HeLa). The agent of virus pneumonia was propagated in primary swine kidney and in HeLa cell cultures as shown by the production of typical gross and microscopic lesions in pigs inoculated with cell future fluids. Third passage cell culture fluids, produced typical gross lesions in pigs, but fourth passage cell culture fluids produced only microscopic lesions, and no lesions were produced by sixth and eleventh passage fluids. Control pigs receiving fluids from uninoculated cell cultures remained free of gross or microscopic lesions, as did uninoculated controls. Cytopathic effects were not detected in any of the inoculated cell cultures and no cellular changes were detected by staining with Giemsa stain or acridine orange. Neither lesions nor deaths occurred in chicken embryos inoculated with both strains of virus pneumonia virus. Pneumonia was not produced in pigs inoculated with suspensions from second chicken embryo passage of the 2 strains inoculated by the chorioallantioic sac, the amniotic sac, and the yolk sac routes. Identical gross and microscopic lesions were produced in pigs inoculated with either pneumonic lung suspensions or with virulent cell culture fluids. Gross lesions consisted of areas of light to reddish-purple consolidation usually limited to the anterior, cardiac, and intermediate lobes of the lungs. Pleuritis and pericarditis were never present in experimentally produced virus pneumonia. The microscopic lesions were characterized by: 1. perivascular and peribronchiolar lymphoid infiltration and hyperplasia, 2. alveolar interstitial thickening and infiltration, and 3. alveolar exudates consisting of alveolar cells, lymphocytes, plasma cells, and neutrophiles.  相似文献   

2.
Techniques for detecting various levels of both field and vaccine strains of infectious bronchitis virus in a deliberately contaminated Newcastle disease vaccine were compared using chick embryos, chick kidney cells, chick tracheal organ cultures and chickens with a view to determining the most appropriate method for screening vaccines for freedom from IBV contamination. Techniques examined included detection of abnormalities and deaths in embryos, cytopathic effect in chick kidney cells, ciliostasis in chick tracheal organ cultures and clinical signs and virus isolation in chickens as well as the fluorescent antibody test, negative contrast electron microscopy and serology where appropriate. Results showed that the techniques capable of detecting both strains of infectious bronchitis virus were, in order of sensitivity, the fluorescent antibody test on allantoic cells from infected embryos, ciliostasis and direct electron microscopy of allantoic fluid. One surprising feature was the poor results obtained using chickens. Some detection was achieved with tracheal virus isolation and tracheal organ cultures prepared from inoculated birds and to a lesser extent with histology and clinical signs, but no technique detected the field strain.  相似文献   

3.
Bortezomib, a novel proteasome inhibitor approved for the treatment of cancer in adults, has recently been introduced in pediatric clinical trials. Any tissue-specific side effects on bone development have to our knowledge not yet been explored. To address this, we experimentally studied the effects of bortezomib in vivo in young mice and in vitro in organ cultures of rat metatarsal bones and human growth plate cartilage, as well as in a rat chondrocytic cell line. We found that bortezomib while efficiently blocking the ubiquitin/proteasome system (UPS) caused significant growth impairment in mice, by increasing resting/stem-like chondrocyte apoptosis. Our data support a local action of bortezomib, directly targeting growth plate chondrocytes leading to decreased bone growth since no suppression of serum levels of insulin-like growth factor-I (IGF-I) was observed. A local effect of bortezomib was confirmed in cultured rat metatarsal bones where bortezomib efficiently caused growth retardation in a dose dependent and irreversible manner, an effect linked to increased chondrocyte apoptosis, mainly of resting/stem-like chondrocytes. The cytotoxicity of bortezomib was also evaluated in a unique model of cultured human growth plate cartilage, which was found to be highly sensitive to bortezomib. Mechanistic studies of apoptotic pathways indicated that bortezomib induced activation of p53 and Bax, as well as cleavage of caspases and poly-ADP-ribose polymerase (PARP) in exposed chondrocytes. Our observations, confirmed in vivo and in vitro, suggest that bone growth could potentially be suppressed in children treated with bortezomib. We therefore propose that longitudinal bone growth should be closely monitored in ongoing clinical pediatric trials of this promising anti-cancer drug.  相似文献   

4.
A rabbit antiserum (A2) directed against the detergent-solubilized fraction of the simian virus 40-transformed mouse embryo fibroblast cell line VLM detects common antigens in primary cell cultures from BALB/c mouse embryos and in transformed cell lines from various species. Positively reacting cell cultures show a set of polypeptides with molecular weight species p86, p74, p68, p46, p42, p40, and p35. As tested by Western blotting procedures, all immunoprecipitated proteins carry immunologically reactive determinants. By analysis with two-dimensional gel electrophoresis, all precipitated polypeptides show charge heterogeneities. Concerning the two major members of the protein set, p40 consists of at least four subspecies with isoelectric points in the range of pH 6.2-6.8, whereas p35 is composed of two subspecies focusing between pH 6.4 and pH 7.2. By comparison of the two-dimensional patterns of p35 of various transformed cell lines, a basic (pH 6.6-7.2) and an acidic (6.4-6.6) charge type of p35 could be observed. Comparative analyses of primary cell cultures from 12-16-day mouse embryos show the immunoprecipitated set of polypeptides only in the 16-day embryo cell cultures. After six further propagations, these cells express the immunoreactive proteins as strongly as the primary cell cultures. In embryonic cell cultures of day 14 of gestation the expression of this set of antigens is induced only when cells are propagated at least six times. Under identical conditions these proteins could not be induced in cell cultures of 18-day-old mouse embryos. None of the polypeptides could be immunoprecipitated from primary mouse kidney cell cultures of 12-day-old mice even when the cultures were propagated at least 15 times. This set of polypeptides is also present in simian virus 40-transformed cells of hamster, rat, monkey, and human origin. These findings suggest that in simian virus 40-transformed mouse cells, in addition to p53, the synthesis of other embryonic antigens is reactivated. The presence of the described set of polypeptides in polyoma virus-transformed cells of rat and mouse origin and in cell lines derived from malignant human tumors might indicate common functions in metabolic patterns of transformed cells.  相似文献   

5.
In this study, the ability of recombinant human macrophage (M) and murine granulocyte-macrophage (GM) colony stimulating factor (CSF) to affect both basal and stimulated bone resorption in fetal rat long-bone organ cultures was assessed. It was found that M-CSF does not affect basal bone resorption or bone resorption stimulated by parathyroid hormone, recombinant human interleukin 1 beta, prostaglandin E2 (PGE2), and 1,25 dihydroxy vitamin D3. Specifically, M-CSF at concentrations as high as 30 nM (1 microgram/mL) did not modulate 45Ca release from fetal rat long bones stimulated by these agents. The addition of recombinant murine GM-CSF (at equal molar concentration to M-CSF) also did not affect bone resorption stimulated by parathyroid hormone and interleukin 1 beta. On the other hand, GM-CSF stimulated basal bone resorption over a 120-h period and augmented the resorption mediated by exogenous PGE2 over a 48-h incubation. In addition, GM-CSF was shown to stimulate production of endogenous PGE2 in cultures of bone rudiments. These effects on bone resorption were blocked by the addition of prostaglandin synthesis inhibitors and specific antibodies to murine GM-CSF. These data indicate that M-CSF does not act as a regulator of bone turnover, but GM-CSF may cause bone resorption by stimulating the synthesis of PGE2 in bone.  相似文献   

6.
To clarify the pathogenicity of Akabane virus for ovine embryos, pregnant ewes were inoculated intravenously with the virus. As a result, all of them were affected with viremia and showed an increase in neutralizing antibody 2 weeks after inoculation. The virus was recovered from many organs of embryos which were inoculated with it at 29--45 days of pregnancy and sacrificed 9--30 days later. In particular, some of these embryos which were sacrificed 15 days after inoculation were found suffering from systemic infection. A large quantity of virus was recovered from the organs all over the body of them. No virus, however was recovered from any organ of embryos which were inoculated with the virus at 81 days of pregnancy and sacrificed 30 days later. Abnormal changes were observed in neonatal lambs born from ewes inoculated with the virus at 30--50 days of pregnancy. They were especially severe when the virus was inoculated at 30 days of pregnancy. They consisted of ankylosis of the limbs, scoliosis, hydranencephaly, porencephaly, stillbirth with dwarfism, and death after birth with dwarfism and weakness. Nothing abnormal was found in any neonatal lambs born from ewes inoculated with the virus at 91--101 days of pregnancy. When embryos exceeded 64 days of intra-uterine life more than 29 days after virus inoculation, it was possible to detect immunoglobulin, IgM or IgG or both, and antibody from the serum. Attempts failed to detect either immunoglobulin from embryos less than 59 days of intrauterine life. No IgA was detected from the serum of any embryo. In almost all the neonatal lambs born from ewes inoculated with the virus at 28--101 days of pregnancy, neutralizing antibody was detected from the serum at the time of birth.  相似文献   

7.
Cardiovascular abnormalities are the leading cause of neonatal death among patients with congenital rubella syndrome (CRS). Although persistence of rubella virus (RV) in fetal endothelium has been repeatedly suggested as a possible cause of cardiovascular birth defects, evidence of the permissiveness of fetal endothelial cells to RV is lacking. In this study we evaluated the ability of RV to infect and persist in primary fetal endothelial cells derived from human umbilical vein (HUVEC). We found that wild type (wt) low passage clinical RV productively infected HUVEC cultures without producing cytopathology or ultrastructural changes. RV did not inhibit host cell protein synthesis, cell proliferation, or interfere with the cell cycle. Persistently infected cultures were easily established at low and high multiplicities of infection (MOI) with both laboratory and wt clinical RV strains. However, synchronous infections of entire HUVEC monolayers were only observed with clinical RV strains. The release of infectious virions into media remained at consistently high levels for several subcultures of infected HUVEC. The results indicate that macrovascular fetal endothelial cells are highly permissive to RV and allow slow persistent RV replication. The findings provide more evidence for the suggestion that vascular pathologies in CRS are triggered by persistent rubella virus infection of the endothelium.  相似文献   

8.
A series of 19 different primary and serial tissue cultures were investigated for their sensitivity to virulent or attenuated rubella virus (RV). Primary guinea pig tissues, a serial passage of baby hamster kidney, and primary human amnion were comparable to African green monkey kidney tissue cultures in their sensitivity. In general, primary human tissues were relatively insusceptible to the Gilchrist strain of RV. RV interfered with the growth of vesicular stomatitis virus. Based on this finding, it was possible to develop an assay method in guinea pig tissue cultures by using VSV as the challenge virus. This system appeared to be comparable in sensitivity to the use of primary monkey kidney tissue cultures for the detection of small amounts of RV and offers the advantages of economy, rapidity, and safety.  相似文献   

9.
Inhibitory factors towards IL-1 have been identified in the urine and in the supernatants of human monocyte cultures and have been shown to act as receptor antagonists. We have investigated whether a natural inhibitor purified from human urine (uIL-1ra) and a recombinant molecule expressed using the gene for an IL-1 antagonist isolated from monocytes (rIL-1ra) can alter responses to human rIL-1 alpha in organ cultures of fetal rat long bones and neonatal mouse calvariae. The two preparations probably contained similar or identical molecules, because an antibody to rIL-1ra reacted with uIL-1ra by Western blot analysis. uIL-1ra and rIL-1ra specifically blocked stimulation of bone resorption by rIL-1 in both culture systems, as well as the increase in PGE2 production in cultured calvariae. Resorptive effects of parathyroid hormone and TNF-alpha were not blocked. The uIL-1ra preparation had some intrinsic resorbing activity, but on gel chromatography this appeared in fractions that eluted earlier than uIL-1ra. Concentration ratios of rIL-1ra to rIL-1 as low as 10 could block the resorptive response of fetal rat long bones, whereas concentration ratios of 100 to 1000 were required to block IL-1 action on neonatal mouse calvariae. The inhibitory effects appeared to be competitive, because increasing concentrations of IL-1 overcame the block of bone resorption in both systems and the inhibition of PGE2 production in calvariae.  相似文献   

10.
Japanese strains of rubella virus have been claimed not to be teratogenic, and tests on three Japanese strains showed that they induced high levels of interferon in human placental cell cultures obtained from conceptuses ranging from 13 to 24 weeks'' gestational age, whereas two strains derived from the U.S.A. induced low levels. Both Japanese and U.S. strains induced similar but low levels in fetal lung cell cultures and leucocyte preparations. A representative Japanese strain and a U.S. strain were both interferon-sensitive. If indeed a strain can be shown to be non-teratogenic it could lead to an alternative, safer rubella vaccine.  相似文献   

11.
The goal of this work was to develop and validate a whole bone organ culture model to be utilized in biomimetic mechanotransduction research. Femurs harvested from 2-day-old neonatal rat pups were maintained in culture for 1 week post-harvest and assessed for growth and viability. For stimulation studies, femurs were physiologically stimulated for 350 cycles 24 h post-harvest then maintained in culture for 1 week at which time structural tests were conducted. Comparing 1 and 8 days in culture, bones grew significantly in size over the 7-day culture period. In addition, histology supported adequate diffusion and organ viability at 2 weeks in culture. For stimulation studies, 350 cycles of physiologic loading 24 h post-harvest resulted in increased bone strength over the 7-day culture period. In this work, structural proof of concept was established for the use of whole bone organ cultures as mechanotransduction models. Specifically, this work established that these cultures grow and remain viable in culture, are adequately nourished via diffusion and are capable of responding to a brief bout of mechanical stimulation with an increase in strength.  相似文献   

12.
The aim of this study was to investigate whether cells of early goat embryos isolated from in vivo-fertilized goats interact with the caprine arthritis-encephalitis virus (CAEV) in vitro and whether the embryonic zona pellucida (ZP) protects early embryo cells from CAEV infection. ZP-free and ZP-intact 8-16 cell embryos were inoculated for 2 h with CAEVat the 10(4) tissue culture infectious dose 50 (TCID50)/ml. Infected embryos were incubated for 72 h over feeder monolayer containing caprine oviduct epithelial cells (COECs) and CAEV indicator goat synovial membrane (GSM) cells. Noninoculated ZP-free and ZP-intact embryos were submitted to similar treatments and used as controls. Six days postinoculation, infectious virus assay of the wash fluids of inoculated early goat embryos showed typical CAEV-induced cytopathic effects (CPE) on indicator GSM monolayers, with fluids of the first two washes only. The mixed cell monolayer (COEC + GSM) used as feeder cells for CAEV inoculated ZP-free embryos showed CPE. In contrast, none of the feeder monolayers, used for culture of CAEV inoculated ZP-intact embryos or the noninoculated controls, developed any CPE. CAEV exposure apparently did not interfere with development of ZP-free embryos in vitro during the 72 h study period when compared with untreated controls (34.6 and 36% blastocysts, respectively, P > 0.05). From these results one can conclude that the transmission of infectious molecularly cloned CAEV-pBSCA (plasmid binding site CAEV) by embryonic cells from in vivo-produced embryos at the 8-16 cell stages is possible with ZP-free embryos. The absence of interactions between ZP-intact embryos and CAEV in vitro suggests that the ZP is an efficient protective embryo barrier.  相似文献   

13.
The pathogenicity of avian nephritis virus (ANV) for embryonating hen's eggs was studied by various routes of inoculation. When inoculated with ANV by the yolk sac route, 6-day-old embryos showed the highest susceptibility and all of them died 3 to 14 days postinoculation (PI). They manifested hemorrhage and edema of the whole body (3 to 6 days PI) and stunting (7 to 14 days PI). The 50% egg-infective dose of the virus by yolk sac inoculation coincided well with the virus titer expressed in plaque-forming units determined on the monolayer of chicken kidney cell cultures. The virus could be passed serially through the chorioallantoic membrane (CAM) of embryonating hen's eggs. In these eggs the CAM presented edematous thickening at the inoculation site, and the embryo stunting. when inoculated by the CAM route, high virus doses killed all embryos, but low virus doses allowed some of the infected embryos to hatch normally. When inoculated by the allantoic cavity route, the virus did not multiply in the allantoic cavity of embryonating eggs, but some of these eggs became infected. Fluorescent antigens were present only in the kidneys and CAM of embryos infected with the virus. The virus was recovered at a low rate from cloacal swabs of chicks from normally hatched eggs inoculated with the virus by the CAM route. These chicks were variable in growth, but had antibodies against the virus and developed nephritis at 36 days of age.  相似文献   

14.
Comparison of Three Methods Used to Isolate Dengue Virus Type 2   总被引:3,自引:0,他引:3       下载免费PDF全文
During the 1969 dengue epidemic in Puerto Rico, human sera and Aedes aegypti mosquitoes were collected for virus isolation and identification. Three methods of isolation were used and compared. In the first method, we inoculated newborn mice by the intracranial route, noted any signs of illness, and serially passed specimens in mice until virus was isolated. In the second method, we inoculated tube cultures of LLC-MK(2) cells, noted any cytopathic effect (CPE), and assayed fluids for virus by plaque formation in LLC-MK(2) cell monolayers. The third method was different from the second only in that the original specimens were first inoculated into fluid cultures of Singh's A. albopictus cells. No significant CPE was seen in LLC-MK(2) cultures; however, distinct syncytial CPE was observed in A. albopictus cells. About the same number of virus isolates were made in each isolation system. Virus isolates from both sera and mosquitoes were identified as dengue type 2 by a plaque-reduction neutralization test in LLC-MK(2) cells. The utility of the three methods, individually or in combination, is discussed and related to diagnostic and epidemic situations.  相似文献   

15.
Stocks of three Indian Chandipura virus (CHPV) isolates; one isolate from an adult febrile case in 1965 from Chandipura town, Maharashtra, and two isolates from two pediatric encephalitis cases from Andhra Pradesh, 2003 were inoculated in 10-day-old chick embryos by allantoic route. All three virus isolates replicated in chick embryos showing titre of log 10(12) to log 10(13) EID50. The results demonstrated that chick embryos are susceptible to CHPV and virus grows to high titres in this system. Therefore chick embryos can be used as an alternative host system for cultivation and isolation of CHPV as they are less expensive than laboratory animals and have several other advantages over cell cultures. Also this system can be used for the development of vaccine and diagnostic reagents.  相似文献   

16.
Neurological disease resulting from lentivirus (including human immunodeficiency virus) infections is usually caused by a strain of virus that replicates productively in microglia in vivo and in macrophage cultures in vitro. We undertook this study using the model of simian immunodeficiency virus in macaques (SIVmac) to test the hypothesis that macrophage tropism is a prerequisite for neurotropism of the virus. Using molecularly cloned SIVmac239, a virus which is lymphocyte- but not macrophagetropic, we showed that this virus failed to infect brain after intracerebral (i.c.) inoculation into two macaques. Rather, these inoculations resulted in disseminated infection in lymphoid organs and the bone marrow. Two sequential passages of infected bone marrow cells inoculated i.c. into new macaques resulted in severe neurological disease and classical neuropathological lesions. Virus obtained from affected brain answered the hypothetical question: it was neurotropic and macrophagetropic. New findings in the study were that both lymphocyte- and macrophage-tropic viruses were present in the animals, but the viruses localized in different tissues: the lymphotropic virus in the spleen, lymph nodes, and plasma and the macrophagetropic virus in the brain and lungs. To determine whether the brain virus was preferentially neurotropic and whether it had neuroinvasive properties, infectious brain homogenate was inoculated into one animal i.c. and into two others peripherally. The i.c. inoculated animal developed fatal encephalitis 5 months later, and examination of tissues showed cell-free virus only in brain homogenates. Only microglia were infected despite persistent viremia and infection in bone marrow cells. The two macaques inoculated peripherally remained healthy and were euthanized at 6 months. Virus replication was detected only in the bone marrow cells and peripheral blood mononuclear cells. No infection in any macrophage population in visceral organs was detected, and the virus did not invade the brain. The strictly microglial specificity of this virus suggested that different macrophage populations in the body may select specific phenotypes of lentivirus from the quasispecies of virus in the bone marrow. This could provide the basis for specific disease affecting different organ systems.  相似文献   

17.
Nerve growth factor in skeletal tissues of the embryonic chick   总被引:3,自引:0,他引:3  
Summary This study demonstrates, via immunohistochemistry and bioassay, the presence of NGF in embryonic bone and cartilage of the chick. Embryos were killed on days 6–9 of incubation at 12 h intervals, and on days 10–18 at 24 h intervals. Paraffin-embedded sections of hind limbs or buds were immunostained with a polyclonal antibody against NGF and the biotin-avidin-horseradish peroxidase technique. Immunostaining was positive in both bone and cartilage, with cartilage staining more intensely. For bioassay, bones from the hind limbs of 9- and 12-day embryos were fast-frozen, lyophilized, and homogenized with Medium 199 (M199). Dorsal root ganglia from 8-day embryos were cultured for 24–36 h with rooster plasma, M199, and varying concentrations of bone homogenate. Significant neurite outgrowth was seen, with the greatest response elicited by 12-day bone homogenate. Addition of anti-NGF to the cultures abolished neurite outgrowth. The results indicate that NGF is present in cartilage and bone of the chick embryo; it may determine the density of sympathetic innervation to the developing skeletal tissues.  相似文献   

18.
The fetal brain is highly vulnerable to teratogens, including many infectious agents. As a consequence of prenatal infection, many children suffer severe and permanent brain injury and dysfunction. Because most animal models of congenital brain infection do not strongly mirror human disease, the models are highly limited in their abilities to shed light on the pathogenesis of these diseases. The animal model for congenital lymphocytic choriomeningitis virus (LCMV) infection, however, does not suffer from this limitation. LCMV is a well-known human pathogen. When the infection occurs during pregnancy, the virus can infect the fetus, and the developing brain is particularly vulnerable. Children with congenital LCMV infection often have substantial neurological deficits. The neonatal rat inoculated with LCMV is a superb model system of human congenital LCMV infection. Virtually all of the neuropathologic changes observed in humans congenitally infected with LCMV, including microencephaly, encephalomalacia, chorioretinitis, porencephalic cysts, neuronal migration disturbances, periventricular infection, and cerebellar hypoplasia, are reproduced in the rat model. Within the developing rat brain, LCMV selectively targets mitotically active neuronal precursors. Thus, the targets of infection and sites of pathology depend on host age at the time of infection. The rat model has further shown that the pathogenic changes induced by LCMV infection are both virus-mediated and immune-mediated. Furthermore, different brain regions simultaneously infected with LCMV can undergo widely different pathologic changes, reflecting different brain region-virus-immune system interactions. Because the neonatal rat inoculated with LCMV so faithfully reproduces the diverse neuropathology observed in the human counterpart, the rat model system is a highly valuable tool for the study of congenital LCMV infection and of all prenatal brain infections In addition, because LCMV induces delayed-onset neuronal loss after the virus has been cleared, the neonatal rat infected with LCMV may be an excellent model system to study neurodegenerative or psychiatric diseases whose etiologies are hypothesized to be virus-induced, such as autism, schizophrenia, and temporal lobe epilepsy.  相似文献   

19.
Direct evidence that IGF-I has any significant effect on embryo growth is lacking. We therefore studied the effect of administration of IGF-I on the chick embryo in ovo. Five hundred ng pure IGF-I (purified from human plasma) were given to chick embryos on 2 occasions (7 and 14 d) by injection directly into the allantoic sac. Treated and control (saline injected) chicks hatched on the same day and were killed. IGF-I appeared to reach the tissues as the [35S]-sulphate uptake of treated sternal cartilage was significantly greater than that of control (P less than 0.02). However, there were no significant effects of treatment on total body weight, bone length measurements, organ (lung, liver, heart) weights, muscle DNA, RNA or protein levels. From these results we conclude that administration of exogenous IGF-I to the chick embryo at 7 and 14 d does not stimulate further growth of the chick embryo.  相似文献   

20.
A case is reported of a term newborn with intra uterine growth retardation and numerous malformations such as complex heart disease, abnormalities of distal limbs, cleft palate. Death occurred after two days. The diagnosis of rubella embryopathy was confirmed by the following criteria: a high level of rubella antibodies in mother and newborn (1/1000) an isolation of rubella virus from the infant's urine. Diagnosis of rubella after reinfection was documented by a high level of antibodies in the mother three years before this pregnancy. Other observations reported in literature confirm the extreme rarity of congenital rubella after reinfection.  相似文献   

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