Genital infections

Direct detection of Molluscum contagiosum virus in clinical specimens by in situ hybridization using biotinylated probe

Molluscum contagiosum virus (MCV) is an unclassified poxvirus which has recently become recognized as causing a major sexually transmitted disease. At present no assay is available for specific detection of MCV because the virus cannot be serially propagated in cell culture. Since MCV produces an abortive, limited growth with some cytopathic effect in certain cell lines, we were able to develop an in situ hybridization assay for detection of MCV genome in clinical specimens. Human fetal diploid lung cell monolayers were infected with clinical specimens, and after proper incubation and fixation in paraformaldehyde, hybridization was performed under full stringency conditions with a molecularly cloned biotinylated probe. Only MCV infected cells showed homology to the MCV probe with a purple-brown cytoplasmic staining. Additionally, we have described an in situ hybridization assay for direct detection of MCV genome in formalin-fixed, paraffin-embedded biopsies. Characteristic intracytoplasmic Molluscum bodies (Henderson-Paterson bodies) were detected in stratum spinosum cells of the epidermis. Striking staining similarities have been observed between in situ hybridization and haematoxylin-eosin cytostaining. These procedures are the first successful identification of MCV genome in clinical samples by molecular hybridization, with sensitivity and specificity equal to or greater than electron microscopy.

Cloning and characterization of a Chlamydia trachomatis L3 DNA fragment that codes for an antigenic region of the major outer membrane protein and specifically hybridizes to the C- and C-related-complex serovars

Chlamydia trachomatis L3 DNA was cloned and expressed in lambda gt11. A recombinant plaque that expressed an antigen that reacted with rabbit polyclonal antichlamydial L3 serum and with two monoclonal antibodies specific for serovars L3 and I was selected from this Chlamydia genomic library. The beta-galactosidase Chlamydia fusion protein was purified by immunoaffinity chromatography and injected into mice to produce monoclonal antibodies. These monoclonal antibodies reacted by Western (immuno-) blot with both the fusion protein and the major outer membrane protein from purified L3 elementary bodies. The chlamydial DNA fragment was shown by DNA sequence analysis to be 168 base pairs in length and to correspond to the constant regions 1 and 2 and the variable segment 1 of the major outer membrane protein gene. The recombinant chlamydial DNA fragment hybridized under stringent conditions by Southern and dot blot analysis exclusively with the DNA from the C- and C-related-complex C. trachomatis serovars.

The role of chlamydial serology in fertile and subfertile men

The incidence of serum antibodies to Chlamydia trachomatis and the possible association of a positive serology on semen parameters in 120 subfertile men were studied. The findings were compared with those of 120 fertile volunteers fathering two or more children. The two groups were divided into those without and those with a history of genito-urinary infection. There was no significant difference (p greater than 0.1) in the prevalence of antibody testing between the subgroups of fertile population. A statistically significant difference in the incidence of antibodies was found between the two subgroups of subfertile population. No significant difference was noted in the semen parameters between Chlamydia-positive and Chlamydia-negative fertile and subfertile patients.

Protective role of magnesium in the neutralization by antibodies of Chlamydia trachomatis infectivity

Neutralization of the infectivity of Chlamydia trachomatis was assessed by using polyclonal antisera and monoclonal antibodies (MAbs). Polyclonal antisera and a species-reactive MAb as well as a subspecies-specific MAb, both of which were directed toward the major outer membrane protein of C. trachomatis, reduced the number of chlamydial inclusion-forming units in an in vitro assay. Neutralization was dependent on the presence of complement. The species-specific MAb reacted with all 15 serovars by a microimmunofluorescence assay and a dot blot enzyme-linked immunosorbent assay with heat-treated elementary bodies. On the other hand, this same MAb reacted with all serovars, except those in the C complex, by the dot blot enzyme-linked immunosorbent assay with viable organisms and neutralized in vitro all 10 serovars tested, except those in the C complex. When neutralization assays were performed in a solution containing Mg2+, neutralization by both polyclonal antisera and MAbs was significantly reduced. A dose response to Mg2+ supplied as MgSO4 revealed that all concentrations tested from 50 to 800 microM had some effect. Concentrations of greater than or equal to 400 microM MgSO4 completely abolished neutralization at the lowest dilution of polyclonal antisera and species-reactive MAb tested. Although Mg2+ also blocked the neutralization effect of the subspecies-specific MAb, this neutralization was not as complete as that observed with the species-reactive MAb. Addition of Mg2+ to the assay over the initial 45 min of incubation of C. trachomatis with MAb and complement showed that the organisms could be rescued to some extent over the first 30 min of incubation, after which time neutralization of infectivity could not be reversed. C. trachomatis treated with Mg2+, the species-reactive MAb, and complement were lethal to mice in an in vivo toxicity and infectivity assay, whereas mice injected with organisms incubated with the same MAb and complement without Mg2+ survived.

The antichlamydial, antiviral, and antiproliferative activities of human gamma interferon are dependent on the integrity of the C terminus of the interferon molecule

The effects of recombinant human gamma interferon (rHuIFN-gamma; two identical monomers of 140 residues in length) and of two re-engineered C-terminal variants, rHuIFN-gamma Tetra-Ser (residues 129 to 132 replaced by serine) and rHuIFN-gamma 125 (two identical monomers of 125 residues each with the last 14 residues plus an additional alanine from the C terminus deleted), were compared in terms of several in vitro biological activities. By using three different human cell lines (HeLa 229, HEp-2, and A549), the interferons were tested for their ability to inhibit: (i) growth of Chlamydia trachomatis; (ii) replication of encephalomyocarditis virus; and (iii) cell growth. rHuIFN-gamma restricted the growth of chlamydiae to 50% of the non-IFN-treated control at concentrations ranging from 0.01 to 0.05 ng/ml, depending on the cell type assayed. One of the modified proteins, rHuIFN-gamma Tetra-Ser, also decreased the growth of chlamydiae, but it required a concentration of approximately 0.5 ng/ml to produce 50% inhibition. rHuIFN-gamma 125 had the lowest antichlamydial activity of the three IFN-gamma variants tested; concentrations of 1 to 20 ng/ml were needed to reduce the growth of C. trachomatis to 50% of that of the control. The relative antiviral and antiproliferative activities of the three IFN-gamma preparations paralleled their antichlamydial activities in these three cell lines. The antiencephalomyocarditis virus activities of rHuIFN-gamma Tetra-Ser and rHuIFN-gamma 125 were reduced by approximately 10-fold and 10(2)- to 10(3)-fold, respectively, compared with the antiviral activity of rHuIFN-gamma. Proliferation of the three cell lines was restricted to approximately 50% of the control with 0.5 to 10 ng of rHuIFN-gamma per ml. Inhibition of cell growth by rHuIFN-gamma Tetra-Ser was significant only at concentrations equal to or greater than 30 ng/ml, and the rHuIFN-gamma 125 variant did not significantly decrease the growth of any of the three cell lines at the concentrations tested. These results suggest that the C-terminal portion of rHuIFN-gamma is critical for maintaining the conformation necessary for inducing the antichlamydial, antiviral, and antiproliferative activities of the molecule.

Comparison of techniques for the selection of bacteria-free sperm preparations

The authors compared the three most commonly used sperm preparation techniques--swim-up, fall-down, and Percoll gradient--for their ability to recover highly motile sperm and minimize bacterial contamination. Eleven human semen samples collected by masturbation were used and run in parallel with the three methods. A semiquantitative bacterial analysis was performed in all samples and results expressed in colony-forming units per milliliter (CFU/ml). The Percoll gradient technique resulted in an average sperm concentration of 5.81 +/- 4.4 X 10(6) ml, and the average bacterial concentration dropped from 8.66 +/- 12.96 X 10(3) CFU/ml in semen to 0.01 +/- 0.03 X 10(3) CFU/ml. The bacterial count was not significantly different when the raw semen was compared with the swim-up or the fall-down preparations. The authors conclude that the Percoll gradient method yields an adequate sperm concentration, with high motility and improved morphology, while eliminating bacterial contamination.

Male fertility and positive Chlamydial serology. A study of 61 fertile and 82 subfertile men

In this study, the frequency and titers of serum antibodies to Chlamydia trachomatis in fertile and subfertile subjects and possible correlations between a positive serology and the values of conventional semen parameters were investigated. The subfertile subjects were divided into those without and those with a history of genitourinary infection. No difference was noted between the proportion of seropositive patients in the fertile group (26.2%) as compared with those in the subfertile group with no history of genitourinary infection (27.7%). The percentage of positive tests was significantly increased only in the subfertile group with past genitourinary infection (53.5%). No difference was found between the antibody titers of the fertile and subfertile groups. Only the fertile group had any semen parameter, namely, the volume of the ejaculate, that was significantly different between the seropositive and seronegative patients. In conclusion, three main points should be stressed; the high frequency of serum antibodies to Chlamydia trachomatis in the control subjects and the apparent absence of effects of a positive serology on their fertility; the significant correlation between a past genitourinary infection and the presence of serum antibodies to Chlamydia trachomatis; and the need for a test to assess Chlamydia in semen.

The demonstration of papilloma virus in cervical dysplasia and/or neoplasia

Thirty-three random biopsy specimens of uterine cervix were studied by immunoperoxidase technique to evaluate the presence of HPV antigen in dysplastic and neoplastic cells. Four cases of mild dysplasia, nine cases of moderate to severe dysplasia, two cases of carcinoma in situ and one case of invasive carcinoma were associated with condylomatous lesions. Intranuclear dark-brown precipitates were observed in superficial and intermediate zones of the dysplastic epithelium. Positive reaction was seen in condylomatous epithelium associated with neoplasia. No nuclear precipitates were observed in carcinoma cells, but one noncondylomatous lesion with moderate dysplasia showed positive intranuclear staining. These preliminary findings suggest that papilloma viruses may play a role in the development of human cervical neoplasias.