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Biomedical subjects

I Sarov

Publications and source records attributed to I Sarov.

At least 91 records · Page 5Linked to original sources

Serum IgG and IgA antibodies specific for Chlamydia trachomatis in salpingitis patients as determined by the immunoperoxidase assay.

The feasibility of applying elevated Chlamydia trachomatis specific IgG antibody and serum IgA antibodies as a non-invasive screening test for C. trachomatis associated salpingitis was analysed in 54 salpingitis patients and 294 apparently healthy women by the single antigen (L2) immunoperoxidase assay (IPA). The prevalence rate of C. trachomatis IgG antibody (titre greater than or equal to 64) was significantly higher in the salpingitis patients in comparison to control (67% versus 23%). The prevalence rate of elevated C. trachomatis IgG titres (greater than or equal to 128, greater than or equal to 256 and greater than or equal to 512) was significantly higher in the salpingitis patients as compared to the controls. For example, at an IgG titre of greater than or equal to 128 the prevalence rate was 57% in the salpingitis patients and 8% in the healthy controls (p less than 0.0001). The prevalence of C. trachomatis IgA antibodies (titre greater than or equal to 16) was significantly higher in salpingitis patients in comparison to controls (37% versus 4%). The prevalence of elevated IgA titres (greater than or equal to 32 and greater than or equal to 64) was found to be significantly higher in salpingitis patients as compared to controls. All the IgG seropositive salpingitis patients were also found to have C. trachomatis IgG antibodies. It appears that testing for IgG antibodies at a serum dilution of 1:128, and for IgA antibodies at a dilution of 1:16 by the IPA test comprises the best combination for the differentiation between the salpingitis patients and apparently healthy controls, and it is suggested that this be used as a marker of active C. trachomatis infection.

Adolescent↗

Recent advances in Chlamydia trachomatis.

Chlamydia trachomatis is an obligate intracellular energy parasitic bacterium with a genome of 660 X 10(6) daltons, possessing a plasmid and unique life cycle which includes the differentiation of the infective elementary body to a replicative reticulate body. C. trachomatis is the etiological agent of trachoma, which affects approximately 500 million people in developing countries. Recently it became evident that in industrialised Western nations certain strains of C. trachomatis are the most common cause of sexually transmitted infections such as non-gonococcal urethritis, cervicitis, endometritis, salpingitis and subsequent ectopic pregnancies or infertility, perihepatitis, neonatal conjunctivitis and pneumonia, adult conjunctivitis and epididymitis. Since C. trachomatis infections are often asymptomatic, widespread screening of sexually active young people is needed in order to initiate early antibiotic treatment which may prevent serious complications such as ectopic pregnancies and infertility. Development of sensitive and simple techniques for mass screening for detection of Chlamydia in excretions as well as techniques for detection of specific markers of chronic internal infections (such as Chlamydia specific IgA antibodies) is of great importance.

Chlamydia Infections↗

Detection of rotavirus-specific IgG antibodies by immunoperoxidase assay and enzyme-linked immunosorbent assay.

An indirect immunoperoxidase assay (IPA) has been developed for determination of IgG antibodies to rotavirus. The technique employed as antigen, SA-11 infected MA 104 cells, which were air-dried on glass slides and acetone-fixed. In parallel, rota-specific IgG antibodies were determined by enzyme-linked immunosorbent assay (ELISA). Specific IgG antibodies to rotavirus were determined in sera of healthy children and in sera of patients suffering from gastroenteritis. A good correlation (r = 0.92) and (r = 0.98) for healthy children and patients, respectively, was found between IPA and ELISA techniques. The IPA technique is rapid and simple and positive results, because of the intensive staining, are easily read by low-power light microscope. The potential application of IPA and ELISA methods in serodiagnosis of rotavirus infections is discussed.

Adult↗

Determination of specific cytomegalovirus IgM antibodies using infected air dried cells and isolated nuclei by immunoperoxidase assay.

A simple immunoperoxidase assay (IPA), adapted for detection of serum IgM antibodies to cytomegalovirus (CMV) is described. The antigen consisted of CMV infected human embryonic fibroblasts or isolated nuclei. The sera were absorbed with aggregated gamma-globulins prior to testing. Rabbit anti-human IgM peroxidase conjugate was used to detect IgM bound to viral antigen. In parallel the enzyme linked immunosorbent assay (ELISA) technique was used to determine IgG and IgM antibodies to CMV, respectively. All patients with acute CMV infections who were tested had CMV-specific IgM antibodies by IPA, both whole cell and nuclei antigen. The maximal IgM titers were higher by ELISA than by IPA but in 3 of the CMV patients IgM was detected earlier by IPA (with both types of antigens) than by ELISA. In 3 of 5 transplant patients with recurrent CMV infection IgM was demonstrated by immunoperoxidase techniques, while by ELISA IgM was demonstrated in only 2 of them. No cross reactivity with other herpes viruses was observed. The described IPA is simple, rapid and has the potential for widespread use in routine laboratories.

Adult↗

Interaction between human polymorphonuclear leucocytes and Chlamydia trachomatis elementary bodies: electron microscopy and chemiluminescent response.

Incubation of human polymorphonuclear leucocytes (HPMN) with highly purified Chlamydia trachomatis serotype L2/434/Bu elementary bodies (EB), in the presence and absence of specific antibody, resulted in a 10(3)-fold reduction of viable count after 24 h incubation. Electron microscopy observations indicated activation of the HPMN by the EB. Attachment of the EB to the HPMN cell membrane, formation of a cytoplasmic cup and EB-containing vacuoles were observed. In addition, two types of phagocytic vacuoles were observed after 30 min incubation; in one type, a single EB was tightly surrounded by the vacuolar membrane, while the other type was enlarged and held one or more intact EB or degenerated EB or both. A fuzzy coat was observed on EB located in the HPMN vacuoles only in the presence of specific antibody. Empty vacuoles containing degenerated EB were observed in the HPMN after 24 h incubation. HPMN exposed to EB of C. trachomatis produced a marked chemiluminescent response with a peak 14 times greater than the peak value of the control. A second stimulation with phorbol 12-myristate 13-acetate and zymosan was achieved. The chemiluminescent peak value in the presence of heat-treated EB (56 degrees C, 20 min) was 50% of that obtained in the presence of untreated EB. The significance of the chemiluminescent response in the killing mechanism of C. trachomatis EB by HPMN is discussed.

Cells, Cultured↗

Inhibition of growth of Chlamydia trachomatis by human gamma interferon.

Treatment of HEp-2 cell cultures with highly purified human gamma interferon before infection resulted in the reduction of Chlamydia trachomatis (L2/434/Bu) infectious particle yield. Electron microscope studies showed that interferon did not affect chlamydial conversion to reticulate bodies but influenced the extent of maturation to elementary bodies. High interferon concentrations (greater than 350 IU/ml) inhibited inclusion body formation and resulted in the appearance of aberrant reticulate bodies.

Cell Line↗

Interaction between polymorphonuclear leukocytes and varicella-zoster virus-infected cells.

The addition of polymorphonuclear leukocytes (PMNL) to human fibroblasts infected with varicella-zoster virus (VZV) resulted in a reduced virus yield. The reduction was greater when antibodies specific for VZV were added to the system. Addition of VZV-specific antibodies without PMNL also reduced virus yield, but a 10-fold greater concentration of antibodies was required to effect the same reduction. PMNL adhered to and formed rosettes around VZV-infected cells. By electron microscopy, it was possible to observe activation of PMNL incubated with VZV-infected fibroblasts. Activated PMNL extended cytoplasmic projections toward virions and had vacuoles containing virions in various stages of digestion.

Cells, Cultured↗

Studies on HSV specific IgA antibodies in lacrimal fluid from patients with herpes keratitis by solid phase radioimmunoassay.

A highly sensitive solid phase radioimmunoassay (RIA) was adapted for determination of herpes simplex virus (HSV) specific IgA antibodies in lacrimal fluids. The RIA procedure was applied to examine HSV IgA antibodies in serial samples of lacrimal fluid and in sera from 14 patients with herpes keratitis. HSV-specific IgA antibodies were detected in the lacrimal fluid of the affected eye in 12 of the 14 patients. HSV IgA antibodies were also detected in the lacrimal fluid of the unaffected eye of 7 of these patients in titers lower than those found in the corresponding affected eye. Evidence for local HSV antibody production in lacrimal fluid in herpes keratitis was supported by examination for antibodies to the unrelated measles antigen. Detection of lacrimal fluid HSV IgA antibodies might be a useful adjunct in rapid diagnosis of herpes keratitis. The advantage of characterizing the local immune response as well as viral expression in the affected vs. the unaffected eye in the same individual as a model for understanding the factors leading to subclinical vs. clinical manifestations of recurrent ocular herpes virus infections will be discussed.

Adolescent↗

Specific IgG and IgA antibodies to herpes simplex virus (HSV)-induced surface antigen in patients with HSV infections and in healthy adults.

Herpes simplex virus (HSV)-specific IgG and IgA antibody response in patients with HSV infection and in healthy adults was studied by the immunoperoxidase antibody-membrane antigen (IPAMA) technique. In all HSV infections in which specific IgM antibodies were detected by enzyme-linked immunosorbent assay (ELISA), a significant rise in the titer of HSV IgG and IgA antibodies was found. In contrast, in patients with recurrent herpes labialis in which no specific HSV IgM antibodies were detected by ELISA, HSV IgG and IgA antibodies were not found to fluctuate significantly during the course of infection. A higher geometric mean titer (GMT) for HSV IgG and for IgA antibodies was found in seropositive individuals with a previous history of recurrent HSV than in seropositive individuals without a previous history of recurrent HSV infection. Nineteen of 26 HSV IgG seropositive healthy medical students without a previous history of recurrent HSV infection had HSV IgA antibodies to membrane antigen. The significance of this finding in understanding the mechanism of latency in healthy seropositive individuals without previous history of HSV recurrent infections is discussed.

Adult↗

A simple immunoperoxidase method for detecting enteric adenovirus and rotavirus in cell culture.

A technique which includes the use of indirect immunoperoxidase antibody (IPA) has been developed for detecting enteric adenovirus and rotavirus antigens in cell cultures and has been compared with immunofluorescence antibody assay (IFA). The IPA technique was as sensitive as the IFA. The number of positive cells detected by both techniques in tissue cultures was the same; false positive results were not observed. The applicability of IPA in clinical virology is discussed.

Adenoviridae↗

Serum specific IgA antibody to Chlamydia trachomatis in patients with chlamydial infections detected by ELISA and an immunofluorescence test.

Sera obtained from 34 men with Chlamydia trachomatis positive non-gonococcal urethritis, 34 men with C trachomatis negative non-gonococcal urethritis, 42 women with acute salpingitis, 38 healthy women, and 34 healthy men were studied for the presence of specific serum C trachomatis IgA and IgG antibodies. Serological results were correlated with C trachomatis isolation in cell culture. An enzyme linked immunosorbent assay (ELISA) for C trachomatis specific serum IgA was employed using highly purified elementary bodies of C trachomatis serotype L2 grown in LLC-MK2 cells. Results obtained for C trachomatis IgA antibody by the ELISA test were compared with results obtained for the same sera by a single antigen immunofluorescence technique. A good correlation (r = 0.91) was found between two methods. Serum IgG antibody was also determined in the same sera by the immunofluorescence technique. Patients with C trachomatis positive non-gonococcal urethritis had a significantly (p less than 0.0005) higher prevalence (94.1%) of serum IgA antibody by ELISA compared with patients with C trachomatis negative non-gonococcal urethritis (20.5%) or healthy men (5.9%). Similarly, women with acute salpingitis had a significantly (p less than 0.005) higher prevalence of serum IgA antibody (45.2%) compared with healthy controls (5.2%). Comparable results were obtained for C trachomatis serum IgA antibody using the immunofluorescence technique. The prevalence of C trachomatis IgG antibody was significantly higher in patients with C trachomatis positive non-gonococcal urethritis (97.0%) compared with those with C trachomatis negative non-gonococcal urethritis (33.3%) and healthy controls (23.5%). The importance of using specific C trachomatis serum IgA in the identification of chlamydial infection is discussed.

Adult↗

Infection of endometrial cells with human cytomegalovirus.

In order to understand the mechanism of congenital human cytomegalovirus (CMV) infection we studied the effect of CMV on epithelial cell culture of the endometrium. Endometrial cells proved to be sensitive to CMV as indicated by morphologic alterations, success to support growth of infectious virus and positive immunoperoxidase staining. The infected cells were enlarged, multinuclear and revealed intranuclear inclusions. Electron microscopy detected the presence of the viral particles in the CMV-infected endometrial cells. The possibility that CMV infection of the endometrial cells may play a role in transmitting the virus to the embryo will be discussed.

Cells, Cultured↗