Almen L. Barron

Characteristics of the BGM line of cells from African green monkey kidney. Brief report.

Since a number of different cont inuous lines or ig inat ing f rom Afr ican green m o n k e y k idney are cur ren t ly in use in virological research, (5, 6, 10) i t was of in teres t to present some of the character is t ics of a cell line f rom th is source, des igna ted BGM, which was in i t i a t ed in our l a bo ra to ry in March, 1962. Studies using BGM cells in research on enteroviruses, m u m p s virus, and herpes s implex virus have been prev ious ly r epor ted (2, 3, 4, 8, 9).

Effects of various doses of estradiol on chlamydial genital infection in ovariectomized guinea pigs.

The effect of various doses of estradiol on genital tract infection by the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC) was investigated in ovariectomized guinea pigs. Prolongation of infection, as determined by chlamydial inclusion counts of cells in Giemsa-stained smears of vaginal scrapings, was observed in animals receiving daily doses of 1.0, 10.0, 100.0, or 1000 μg of estradiol. In contrast to controls, ascending infection resulting in endometritis was found in animals receiving doses of ≥1.0 μg of estradiol per day. Response to estradiol treatment was reflected in an increase in cervical-uterine wet weight and uterine wall thickness. No differences were observed in time of appearance of antibody titers to GPIC in serum, but a delay in appearance of IgA antibody to GPIC in genital secretions was found in estradiol-treated animals receiving doses of ≥1.0 μg per day.

Distinctive Cytopathology of ECHO Viruses Types 22 and 23.

Summary The cytopathology of ECHO 22 and 23 was compared with other enteroviruses and found to be distinctive. The important differentiating features appeared in the nucleus. An eventual disappearance of the nucleolus and nuclear chromatin and a thickening and increase in staining intensity of the nuclear membrane resulted in appearance of an empty nucleus. Seven isolates of ECHO 22 were found to have similar cytopathic changes. It is suggested that detailed study of the cytopathic effect of viruses in tissue culture may play an important role in relating new agents to the enterovirus group.

Phase variation in ECHO virus type 6

Abstract Strains of ECHO virus type 6 isolated during an epidemic of aseptic meningitis in 1955 were shown to react poorly in neutralization test with homologous or heterologous ECHO 6 antisera (virus in S phase). However, after passage in monkey kidney tissue culture, the strains reacted very well with such sera (virus in B phase). Alteration in other biologic characteristics accompanied this change in phase.

Absence of progesterone effects on chlamydial genital infection in female guinea pigs

The effect of progesterone alone and in combination with estradiol was investigated in ovariectomized and gonadally intact female guinea pigs infected with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). The course of the infection, as determined by the percentage of cells with GPIC (chlamydia) inclusions in Giemsa-stained vaginal scrapings, was not affected in animals receiving 5.0 mg of progesterone daily. Progesterone had no influence on the enhancement of infection by estradiol. In comparison with sesame oil-treated controls, infection was prolonged by four to six days (P less than .05) in animals receiving a combination of 5.0 mg of progesterone plus 1.0 microgram of estradiol or 1.0 microgram of estradiol alone each day. In ovariectomized animals, estradiol delayed the appearance of IgA antibody in genital secretions, whereas progesterone alone had no effect. Guinea pigs treated with estradiol or progesterone plus estradiol manifested an acute endometritis not observed in animals treated with progesterone alone or in controls receiving sesame oil. Although cervical ectopy, analogous to that seen in women with high levels of progesterone, was identified by histopathology in animals treated with progesterone, no enhancement of the chlamydial infection was observed.

Chlamydial salpingitis in female guinea pigs receiving oral contraceptives.

Female guinea pigs were given daily doses of a combination of oral contraceptive (OC) agents, consisting of mestranol and norethynodrel suspended in sesame oil or distilled H2O, and were infected in the genital tract with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). Counts of chlamydial inclusions in cells of vaginal smears collected during infection, showed prolongation and enhancement of infection in OC-treated animals as compared with controls. Appearance of IgG and IgA antibodies to GPIC in genital secretions, as determined by enzyme-linked immunosorbent assay (ELISA), was also delayed in OC-treated animals as compared with controls. OC-treated infected animals were killed on days 15 and 43, and gross pathological evidence for ascending infection culminating in salpingitis was found in all of five and four of five animals, respectively. On the other hand, among untreated infected controls on each sacrifice day, only one of five animals had any evidence for ascending infection. Chlamydiae were detected by light and electron microscopy in fallopian tube tissue collected on day 15 following OC-treatment but not in tissue from control animals.

Cystitis associated with chlamydial infection of the genital tract in male guinea pigs.

Male guinea pigs were infected with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC) by intraurethral injection of chlamydiae or by placement of a drop of chlamydial suspension on the meatus of the extruded penis. Transient urethritis and cystitis were observed in animals infected by either method. The production of cystitis by the drop-on technique indicated that chlamydiae are able to ascend the urethra and that the bladder may be a target organ of chlamydial infection. When infected animals were immunosuppressed with cyclophosphamide, the number of guinea pigs with cystitis was increased, and chlamydiae could be detected in the bladder for as long as 50 days after infection. In contrast, GPIC was not detected in the bladders of untreated animals after day 18.

Studies on a strain of vaccinia virus defective in surface antigen production.

Summary A strain of vaccinia, V1-010, was discovered which is defective in surface antigen production as detected by mixed agglutination. Evidence for existence of major and minor surface antigens on vaccinia-infected cells was obtained. Minor surface antigen could be distinguished from the major antigen serologically as well as by the pattern of mixed agglutination reactions. V1-010 was capable of producing minor surface antigen and hemagglutinin.

Comparative cytopathology of canine distemper and measles viruses in ferret kidney cell cultures

Multinucleated giant cells, cytoplasmic and intranuclear inclusions were characteristic findings in ferret kidney cultures inoculated with canine distemper virus. Variations observed among strains were of a quantitative nature and these did not serve as distinguishing features. Contracted giant cells were observed which were interpreted as being degenerative forms of the multinucleated giant cells. Ferret kidney cell cultures inoculated with measles virus showed the same characteristics.

Gel precipitation with ECHO 4 and other enteroviruses.

Summary Double diffusion gel precipitation was used to detect antibodies in sera of patients suffering from ECHO infections. Two lines of precipitation were observed. One of them was apparently group specific and represented an antigen shared by human enteroviruses. The other line was serotype specific. The pattern of reactions with patient sera as well as animal immune sera confirmed the previous observation on serologic difference between prototype and Shropshire strains of ECHO 4.