The lysate from bovine erythrocytes infected withBabesia bovis

A group ofBabesia bovis antigens obtained by a lengthy biochemical procedure involving disruption of infected erythrocytes has previously been shown to be highly protective. This study shows that these antigens can be found in a simple lysate of infected erythrocytes. The antigens have been characterized by gel filtration and nitrocellulose transfer and consist of a wide spectrum of molecular sizes. Some of the antigens exist in complex form and are easily dissociated. The lysate was polymerized with glutaraldehyde and injected per se into four splenectomized calves. All the calves produced antibody toB. bovis but did not produce erythrocytic isoantibodies. The vaccinated calves and a control group of four splenectomized calves were challenged with virulentB. bovis. Statistically, the vaccinated group differed significantly in parasitaemia, temperature change and pathophysiological parameters from the control group. All of the control group died whereas two of the vaccinated group survived infection.     

Antiviral factor isolated from infected cell cultures

An antiviral factor of protein nature inhibiting reproduction of VEE, herpes, vaccinia VSV, fowl plague viruses was isolated from infected cell cultures. The factor has no virucidal or prophylactic effect, stable to low pH values and heating at 100 degrees C for 30 min.     

Persistence of cytomegalovirus in human lymphoblasts and peripheral leukocyte cultures.

The in vitro susceptibility of human peripheral lymhpocytes and lymphoblastoid (F265) cells to infection by human cytomegalovirus was examined. Infection of these cell types with cytomegalovirus resulted in a persistent type of infection rather than the typical growth curve observed with permissive fibroblastic cells. When infection of peripheral lymphocytes was associated with a blastogenic response, the virus persisted for a longer time and at a higher titer than in cells in which a blastogenic response did not occur. Autoradiographic studies and infectious-center assays indicated that only a small number of cells, resembling lymphocytes, were involved in virus persistence. Whether or not the persistence of the virus indicates release of input virus or synthesis or new virus was not determined.     

Islet cell cultures obtained from bovine fetal pancreas

Research Institute of Transplantology and Artificial Organs, Ministry of Health, Moscow. (Presented by Academician V. I. Shumakov, Academy of Medical Sciences.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 4, pp. 404–406, April, 1992.     

Purification of merozoites ofTheileria sergenti from infected bovine erythrocytes

A simple and rapid method for purifying merozoites ofTheileria sergenti from infected bovine erythrocytes was developed. Infected erythrocytes were lysed by the use of a cytolytic toxin produced byAeromonas hydrophila and the lysate was subjected to ultracentrifugation in a Percoll discontinuous density gradient. Pure and morphologically intact merozoites free of erythrocyte membrane were recovered from a band formed at the interface of 40% and 60% (by vol.) Percoll solutions. In this merozoite fraction, contamination of erythrocyte membrane proteins was not detected as examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.     

The relationship between mitochondrial genotype and mitochondrial phenotype in lymphoblasts with a heteroplasmic mtDNA deletion

The relationship between mitochondrial genotype and mitochondrialphenotype was investigated in lymphoblasts derived from a patientwith the Pearson syndrome. In 70% of the mtDNA of this Pearsoncell line a deletion from within the COX II gene to within theND5 gene was present. The deletion led to a reduced expressionof the deleted genes, but the severely lowered synthesis ofe.g. subunlt II of cytochrome c oxidase was not reflected ina significant decrease in the cytochrome c oxidase activity.Moreover, there were no obvious differences between controlcells and Pearson cells regarding the capacity for oxidativephosphorylation. Analysis of the synthesis and assembly of bothnuclearly and mitochondrially encoded subunlts of cytochromec oxidase showed that normally mtDNA-encoded polypeptides areproduced in excess. This overproduction fully explained thediscrepancy between the severe defect in the expression of themitochondrial genome and the normal mitochondrial function inthe Pearson cells. These data demonstrate that the expressionof one or more mitochondrial genes can be reduced specificallyat intermediate percentages of deleted mtDNA. However, the dataalso suggest that whether or not a lower expression of mitochondrialgenes encoding subunits of enzymes involved In oxidative phosphorylationinfluences the normal function of these enzymes depends on therelative abundance of the mitochondrial subunits In tissuesor cells with deleted mtDNA.     

Development of second-generation schizonts,gamonts and oocysts of Eimeria bovis in bovine kidney cells

Summary First-generation merozoites of Eimeria bovis, obtained from calves which had been inoculated 14, 14 1/2 and 15 days earlier, were inoculated into monolayers of Madin-Darby bovine kidney (MDBK) and primary embryonic bovine kidney (BEK-1), as well as kidney cell aggregates (BEK-2). Cultures were examined at intervals of 1–12 hr for 168 hr with phase-contrast microscopy and then fixed, stained and re-examined with bright-field microscopy. Fourteen-day merozoites entered all cell types, whereas 14 1/2- and 15-day merozoites did not enter any. Development beyond the first-generation merozoite stage occurred in BEK-1 and BEK-2, but not MDBK. Intermediate and mature second-generation schizonts with 24–36 merozoites were seen at 48–108 hr. Merozoites were 4.5 by 1.4 m, with a posteriorly located nucleus. Young, intermediate, and mature microgamonts were seen at 72–96 hr, 72–120 hr, and 96–120 hr, respectively. Young, intermediate, and mature macrogamonts were seen at 48–96 hr, 72–120 hr, and 96–120 hr, respectively. Mature microgamonts and macrogamonts were 14.7 m in diameter and 19.5 by 15 m, respectively. At 120–168 hr, zygotes in various stages of oocyst wall formation and oocysts (24.4 by 15 m) were seen. A crescent body was present in the parasitophorous vacuole of some schizonts and gamonts.Abbreviations to All Figures C crescent body - HN host cell nuclcus - M merozoite - MI microgamete - N nucleus of parasite - NU nucleolus of parasite - PG plastic granule - PV parasitophorous vacuole - OW oocyst wall - S satellite body This investigation was supported by PHS Research Grant No. AI-04788 from the National Institute of Allergy and Infectious Diseases. Published as Journal Paper No. 1468, Utah Agricultural Experiment Station.     

The fine structural demonstration of monoaminergic synapses in immature rat neocortex

The radial distribution of monoaminergic (MA) synapses has been studied in lateral neocortex (SI) of infant rats using an electron microscopic histochemical technique. Systemically administered 5-hydroxydopamine crosses the blood-brain barrier and produces small granular vesicles (SGV) in 30% of all synaptic terminals in SI. In the primordium of layer IV, at six days postnatal, 70% of the synaptic terminals contain SGVs. Immature cortex thus contains a high proportion of synapses with a vesicular uptake-storage mechanism for catecholamines. It is proposed that in infant rat there is a major projection from brain stem MA nuclei to the neocortex; this projection may exert a potent influence on the activity of neurons in layer IV.     

Subacute encephalitis and hydrocephalus in hamsters caused by measles virus from persistently infected cell cultures

Newborn hamsters were inoculated intracerebrally with measles virus materials from Lu 106 and Vero carrier cell lines. Extracellular and cell-associated materials from cultures incubated at 37°C and at 33°C were used. The lower temperature allows accentuated virus replication. No animals contracted acute encephalitis, but 8 animals developed advanced neurological disease (unsteady gait, serial myoclonic jerks, hypoactivity) 79 to 212 days after injection. Seven out of these 8 animals belonged to a group of 50 animals, which had been inoculated with cell-associated material from cultures incubated at 33°C. Viral antigen and nucleocapsids were found in neurons and glial cells from diseased animals, which showed degenerative changes and inflammation, particularly in the mesencephalon. Some of these animals also had hydrocephalus, which, however, also occurred in many apparently healthy animals. Also this pathological alteration occurred most frequently (5 out of 11 animals examined 9–10 months after inoculation) in hamsters receiving cell-associated material from carrier cultures incubated at 33°C. Possible mechanisms for the appearance of hydrocephalus are discussed.     

The kinetics of adenovirus infection and spread in cell cultures infected with low multiplicity

Summary The cause for the long incubation period required till the appearance of the CPE in cell cultures inoculated with small amounts of adenovirus was investigated with adenovirus type 5 in HeLa cell cultures. The spread of virus in a culture from cell to cell is minimal, as shown in cultures with antiserum in the medium. The spread by spontaneously released virus via the medium is much more important. It can be accelerated by repeated subcultivation after freezing and thawing the cells in 2 or 3 days' intervals. The quantity of virus produced by one infected HeLa cell was found to be 200 TCID₅₀ within 48 hours, independent of the MOI. The growth cycle too is largely independent of the virus dose. The data suggest that the long duration of the incubation period is fully explained by a burst size of 200, a cycle length of 40 to 48 hours and the assumption of a slow and steadily working process of spontaneous release of virus into the medium. Some other possible causes, like impurities in the inoculum or slow and asynchronous early stages of infection, have been ruled out by appropriate experiments.With 9 FiguresAided by a grant from the Deutsche Forschungsgemeinschaft.     

The production of bovine interferon in foetal and adult organ cultures and in leukocytes

Interferon response in bovine foetal and adult organ cultures after induction in vitro with Radom velogenic strain of Newcastle disease virus (NDV-R) was studied. Interferon was produced in foetal organ cultures derived from skin, liver, heart, lungs, kidneys, tongue and also from amniotic membranes and placenta; however, no correlation between the gestational age and levels of interferon produced by different tissues was observed. In comparison with foetal tissues the organ cultures derived from liver, heart, lungs, kidneys and spleen of cows produced higher interferon titers. In contrast to organ cultures, the interferon response of in vitro cultivated leukocytes isolated from spleen and liver of foetuses and cows was comparable. The antiviral substance both from foetal and adult animals was characterized as interferon by standard criteria; however, higher acid lability of "foetal" interferon in comparison with that of "adult" was observed.     

Cell cultures from the bovine fetal pancreas obtained by the use of collalytin

The morphological characteristics of primary monolayer cultures obtained from the bovine fetal pancreas are described. Dispersion of the pancreatic tissue was achieved by combined treatment with solutions of trypsin and collalytin, a preparation with collagenase activity. The cultures thus obtained included many epithelial cells corresponding in their morphological and functional characteristics to cells of the islets of Langerhans: Aldehyde-fuchsinophilic granules were found in their cytoplasm; degranulation of these cells took place if the glucose concentration in the nutrient medium was increased.Laboratory of Pathomorphology, Institute of Transplantation of Organs and Tissues, Ministry of Health of the USSR. Laboratory of Technology of Organ Preparations, All-Union Scientific-Research Institute of the Meat Industry, Ministry of the Meat and Dairy Industry of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 350–353, March, 1977.     

Light and electron microscopic examination of endothelial cells from bovine retinal vessels in long-term cultures

The aim of the present work was to examine and compare the ultrastructure of bovine retinal endothelial cells (BRECs) in vitro during several passages in a medium selective for endothelial cells. The identity of the endothelial cells was confirmed immunohistochemically, up to the tenth passage. Changes in their ultrastructure in comparison to endothelial cells in vivo occurred at the onset of culturing and not progressively with repeated passages. The cultured BRECs show high metabolic activity in all passages. While retaining their identity as endothelial cells, they modify their lipid metabolism, so that lipids are stored. This change in lipid metabolism was induced by the medium. Received: 19 May 1999 / Accepted: 4 August 1999     

The fine structural localization of acetylcholinesterase activity in the rat parotid and sublingual glands

The fine structural localization of acetylcholinesterase activity was studied in the rat parotid and sublingual glands. In both glands, reaction product was found in association with the axolemmae of stromal axons invested by Schwann cells and between the contact with effector cells. In the sublingual gland, reaction product was also found in association with surface vesicles and pits and the rough endoplasmic reticulum of myoepithelial cells.     

The growth of foot-and-mouth disease virus in organ cultures of bovine tissues

Summary Various bovine tissues were culturedin vitro, the dorsal soft palate and the lateral pharyngeal wall were maintained satisfactorily but tongue epithelium, lymph node and lingual muscle did not survive well.Where cultures of tongue epithelium and the lateral pharyngeal wall were infected with a high input of virulent virus at 2 days post-culture, reproducible results in terms of virus yield were obtained, other tissues gave more variable results but in all cases, replication occurred.The multiplication of attenuated and virulent strains in organ cultures was compared and it was found that attenuated strains did not multiply to as high a titre as virulent strains and the percentage of successful infections was lower.It was concluded that organ cultures were suitable for differentiating between certain attenuated and virulent strains of FMDV.