Search PubMed⌕ Search

Biomedical subjects

J L Sever

Publications and source records attributed to J L Sever.

At least 163 records · Page 9Linked to original sources
PubMed1978

Experimental group B streptococcal infection in the rhesus monkey. I. Disease production in the neonate.

Group B streptococci (GBS) are responsible for serious infections of newborn infants. An experimental model for GBS infection was developed in the newborn rhesus monkey in order to obtain more information concerning the pathogenesis of such infections. A series of 29 newborn monkeys were inoculated with either type Ic or type III GBS or sterile broth. Fatal neonatal meningitis without associated pneumonia was produced consistently following intracerebral inoculation with either type Ic or type III; intracerebral inoculation with sterile broth produced no apparent disease. Variable disease production followed intravenous or intra-amniotic GBS inoculation, and clinical manifestations ranged from no apparent disease to fatal meningitis and pneumonia. This monkey model may be useful for further investigation of treatment and prevention of neonatal GBS infection.

Animals↗
PubMed1978

Brain tumors in owl monkeys inoculated with a human polyomavirus (JC virus).

Owl monkeys were inoculated intracerebrally, subcutaneously, and intravenously with JC, BK, or SV40 virus. Two of four adult owl monkeys inoculated with JC virus, a human polyomavirus, developed brain tumors at 16 and 25 months after inoculation, respectively. A grade 3 to grade 4 astrocytoma (resembling a human glioblastoma multiforme) was found in the left cerebral hemisphere and brainstem of one monkey. The second monkey developed a malignant tumor in the left cerebral hemisphere containing both glial and neuronal cell types. Impression smears prepared from unfixed tissue of this tumor showed cells that contained polyomavirus T antigen. Virion antigens were not detected. Tumor cells cultured in vitro also contained T antigen but were negative for virion antigen. Infectious virus was not isolated from extracts of this tumor.

Antibodies, Viral↗
PubMed1978

Viral infections in pregnancy.

The responsibility of the physician for viral infections in pregnancy has changed dramatically in the last 15 years. Genital herpes infections have become much more frequent, and the recognition of these infections in women near term is particularly important. Cytomegaloviruses have been found to be the most commom cause of congenital infection, but no satisfactory methods are available for prevention or treatment. Varicella is now recognized as a teratogen when infection occurs in the first 4 months of pregnancy. It can also cause severe generalized disease in the newborn when infection takes place in the last few days of gestation. Hepatitis B infections are becoming more frequent in many populations, and this virus can transmit to the child, particularly when maternal infection occurs in the last trimester. Venezuelan equine encephalitis virus has been found to be a teratogen. This must be considered in southern states such as Florida and Texas, as well as in Central and South America. Rubella, fortunately appears to be coming under control with the intensive use of serodiagnosis and vaccines in the United States.

Chickenpox↗
PubMed1978

Enzyme-linked immunosorbent assay determination of specific rubella antibody levels in micrograms of immunoglobulin G per milliliter of serum in clinical samples.

A "microgram assay" is described in which solid-phase enzyme-linked immunosorbent assay is used for the determination of specific rubella immunoglobulin G (IgG) antibody levels in micrograms per milliliter of serum. The quantitation was based on a standard curve obtained by using a reference serum, for which the specific IgG content was assayed by immunochemical purification. IgG was first purified and specific rubella antibodies were separated by an immunoadsorbent prepared by linking rubella virus antigens to Sepharose 4B. By using IgG-specific conjugate, the levels of specific rubella IgG antibodies could then be determined from clinical samples. Seronegative samples showed antibody levels less than 1 microgram/ml, whereas levels up to several hundred micrograms per milliliter were detected in some postinfection sera. The correlation between microgram antibody levels and hemagglutination inhibition titers was linear. The method offers a simple and sensitive antibody assay which could be used both for the laboratory diagnosis of acute rubella and for the evaluation of immunity.

Antibodies, Viral↗
PubMed1978

Multiple sclerosis associated agent (MSAA): failure to confirm an association with multiple sclerosis.

Recent reports indicate that a multiple sclerosis agent (MSAA) has been isolated. This agent was detected in mice by a depression in the percentage of mouse polymorphonuclear neutrophils (PMNs). We attempted to repeat these studies using coded specimens. The test, itself, was extremely variable and difficult to reproduce. In the first study, three of three multiple sclerosis (MS) patients and one of two control patients' specimens showed some PMN depression. In a repeat study of these same samples, one of three MS patients and one of two controls were associated with PMN depression. With a second set of coded specimens, one of four MS patients, one of three patients with neurologic diseases, and none of three controls showed PMN depression. We were unable to confirm the presence of MSAA and conclude that the results were random.

Adult↗
PubMed1978

Multiple sclerosis: cellular and humoral immune responses to several viruses.

One hundred and eight multiple sclerosis (MS) patients and 108 matched controls were studied for antibody levels and cellular immune responses to several viruses. There were significant increases in the mean titers of complement fixation (CF) or hemagglutination inhibition (HI), and complement-mediated cytotoxicity (CMC) tests for measles antibodies in MS patients; there was no increase in antibody titers to herpesviruses 1 and 2, or cytomegalovirus (CMV). The direct migration inhibition (DMI) tests showed no difference between MS patients and controls for measles, CMV, herpesviruses 1 and 2, or vaccinia virus antigens. Lymphocyte-mediated cytotoxicity (LMC) tests showed no difference between patients and controls, using cultures infected with measles and CMV viruses. In a study of stimulation or blocking of the LMC response by serum or cerebrospinal fluid (CSF), no effect was found. Therefore, increased levels of measles antibody in serum were again demonstrated in MS patients, but there was no difference in these patients' cellular immunity to measles virus versus that of the controls, and there was no abnormality of cellular immunity against the other viruses tested.

Antibodies, Viral↗
PubMed1977

Absence of measles-virus antigen in jejunum of multiple-sclerosis patients.

Measles antigen was not demonstrated in the jejunal tissue of four patients with multiple sclerosis. There was non-specific staining in cells of the lamina propria, basement membrane, and epithelial cells of the jejunum from patients with multiple sclerosis, human controls, and normal monkeys. This staining was not observed after proper absorption of reagents nor after application of Evans-blue counterstain.

Animals↗
PubMed1977

Congenital cerebral and ocular malformations induced in rhesus monkeys by Venezuelan equine encephalitis virus.

Rhesus monkey fetuses were inoculated with Venezuelan Equine Encephalitis (VEE) vaccine virus by the direct intracerebral route at approximately 100 days gestation to determine possible teratogenicity of the virus. Congenital micrencephaly, hydrocephalus and cataracts were found in all animals and porencephaly in 67 percent of the cases. The virus replicated in the brain and other organs of the fetus. VEE vaccine virus is teratogenic for non-human primates and must be considered a potential teratogen of man.

Animals↗
PubMed1977

Comparison of the enzyme-linked immunosorbent assay and the indirect hemagglutination test for detection of antibody to cytomegalovirus.

Thirty samples of serum were tested for antibody to cytomegalovirus by enzyme-linked immunosorbent assay (ELISA) and indirect hemagglutination (IHA). The two tests were in extremely close agreement. Of the 30 sera evaluated by ELISA, 16 were considered to be positive and 14 were considered negative. In all 16 positive samples, the titers by ELISA were at least twofold to 10-fold higher than the indirect hemagglutination titers. Two of the 14 sera evaluated as negative by the ELISA test had low indirect hemagglutination titers (1:8 and 1:4). They were not detectable at the initial dilution (1:50) of the ELISA test. These two sera might have been classified as positive if the initial dilution in ELISA had been lower than 1:50.

Animals↗
PubMed1977

Disodium phosphonoacetate in cream base as a possible topical treatment for skin lesions of herpes simplex virus in cebus monkeys.

Disodium phosphonoacetate (PAA) in a cream-ointment base was applied to herpesvirus skin lesions on the genitalia of cebus monkeys. The lesions had been produced by the intradermal injection of herpes simplex virus type 2. Concentrations of 0.2, 2, and 5% PAA were used. Liberal application of PAA at concentrations of 2 and 5% proved extremely irritating and produced extensive, severe lesions over the treated area. The 2% PAA, when applied carefully to the lesion area, proved less irritating, but did not reduce healing time when compared with the placebo-treated animals. The 0.2% PAA caused slight reduction in lesion size and duration, but these differences were not statistically significant when compared with placebo-treated animals.

Animals↗
PubMed1977

Lack of association between defective delinquents and antibody of herpesvirus hominis.

Several groups have reported a relation between herpesvirus hominis infection and certain psychiatric disorders. We have investigated herpes antibody levels in chronic criminal offenders who were diagnosed as defective delinquents and in criminals who were not defective delinquents. We found no difference in the frequency of titers of herpesvirus type I or type 2 antibody in these groups.

Adolescent↗