Prostatic acid phosphatase and sperm in the post-coital vagina

The High Content of Fructose in Human Semen Competitively Inhibits Broad and Potent Antivirals That Target High-Mannose Glycans

Semen is the primary transmission vehicle for various pathogenic viruses. Initial steps of transmission, including cell attachment and entry, likely occur in the presence of semen. However, the unstable nature of human seminal plasma and its toxic effects on cells in culture limit the ability to study in vitro virus infection and inhibition in this medium. We found that whole semen significantly reduces the potency of antibodies and microbicides that target glycans on the envelope glycoproteins (Envs) of HIV-1. The extraordinarily high concentration of the monosaccharide fructose in semen contributes significantly to the effect by competitively inhibiting the binding of ligands to α1,2-linked mannose residues on Env. Infection and inhibition in whole human seminal plasma are accurately mimicked by a stable synthetic simulant of seminal fluid that we formulated. Our findings indicate that, in addition to the protein content of biological secretions, their small-solute composition impacts the potency of antiviral microbicides and mucosal antibodies.IMPORTANCE Biological secretions allow viruses to spread between individuals. Each type of secretion has a unique composition of proteins, salts, and sugars, which can affect the infectivity potential of the virus and inhibition of this process. Here, we describe HIV-1 infection and inhibition in whole human seminal plasma and a synthetic simulant that we formulated. We discovered that the sugar fructose in semen decreases the activity of a broad and potent class of antiviral agents that target mannose sugars on the envelope protein of HIV-1. This effect of semen fructose likely reduces the efficacy of such inhibitors to prevent the sexual transmission of HIV-1. Our findings suggest that the preclinical evaluation of microbicides and vaccine-elicited antibodies will be improved by their in vitro assessment in synthetic formulations that simulate the effects of semen on HIV-1 infection and inhibition.

An Optimized Centrifugal Method for Separation of Semen from Superabsorbent Polymers for Forensic Analysis

Connection of a perpetrator to a sexual assault is best performed through the confirmed presence of semen, thereby proving sexual contact. Evidentiary items can include sanitary napkins or diapers containing superabsorbent polymers (SAPs), complicating spermatozoa visualization and DNA analysis. In this report, we evaluated the impact of SAPS on the current forensic DNA workflow, developing an efficient centrifugal protocol for separating spermatozoa from SAP material. The optimized filtration method was compared to common practices of excising the top layer only, resulting in significantly higher sperm yields when a core sample of the substrate was taken. Direct isolation of the SAP-containing materials without filtering resulted in 20% sample failure; additionally, SAP material was observed in the final eluted DNA samples, causing physical interference. Thus, use of the described centrifugal-filtering method is a simple preliminary step that improves spermatozoa visualization and enables more consistent DNA yields, while also avoiding SAP interference.

SPERM HY-LITER™ for the identification of spermatozoa from sexual assault evidence

Accurate microscopic identification of human spermatozoa is important in sexual assault cases. We have compared the results of examinations with (1) a fluorescent microscopy method, SPERM HY-LITER™, and (2) Baecchi's method for identification of human spermatozoa. In 35 artificial, forensic type samples, spermatozoa were identified in 45.7% with SPERM HY-LITER™ in Copenhagen, in 54.3% in the laboratory of the manufacturer of SPERM HY-LITER™, and 40.0% of the samples with Baecchi's staining method. When differences occurred between the two methods, it was significantly more often that SPERM HY-LITER™ detected spermatozoa when Baecchi's method did not (ts=6.567, df=1, P=0.048). This trend was also seen in selected compromised or degraded samples and in selected adjudicative samples. The reactions with spermatozoa from dog, horse, pig and bull were negative with SPERM HY-LITER™, whereas Baecchi's method was non-selective. Data from forensic casework samples in Copenhagen from two years (2008 and 2009) are presented. The samples from 2008 were investigated using Baecchi's method, while those from 2009 were investigated using SPERM HY-LITER™. The frequencies of positive results were similar between the two methods for the two years (27.9% and 32.1% respectively). Analysis of acid phosphatase (ACP) activity for the positive results obtained for these two years does not support the use of a negative ACP result as a prescreen for microscopic analysis for spermatozoa.

Comparison between prostate specific antigen and acid phosphatase for detection of semen in vaginal swabs from raped women

OBJECTIVE

To compare the effectiveness of the prostate specific antigen (PSA) test and the acid phosphatase (AP) test for semen detection in human vaginal samples.

MATERIAL AND METHOD

The source materials were vaginal swabs that were tested at Ramathibodi Hospital between 2008 and 2010 from 2450 cases of raped women. Each swab was tested for semen by three methods: sperm detection by light microscopy, the AP enzymatic reaction, and the presence of PSA by using an immuno-chromatographic rapid kit test. The efficiencies of the AP and PSA tests were compared using the light microscopy result for the presence of sperm as the gold standard.

RESULT

The specificities of the AP, the PSA and the combined AP-PSA tests were 96.4%, 92.3% and 91.9%, respectively, and the sensitivities were 65.5%, 80.4% and 84.5%, respectively. The receiver operating characteristic (ROC) area of the AP, PSA and combined AP-PSA tests were 0.8091, 0.8639 and 0.8823, respectively. The ROC area of the PSA test was significantly greater than that of the AP test (p < 0.0001), and the ROC area of the combined AP-PSA test was significantly greater than both the tests individually (p < 0.0001).

DISCUSSION

Based on the ROC area, the PSA test was better than the AP test for semen detection in the vaginal swabs, and the combined results (AP + PSA) were better than the individual tests. The specificity of the AP test was higher than the PSA test in this study because a positive detection was made within only 15 s. While the PSA test was more convenient as it was available in a rapid test kit format, our recommendation is PSA detection should be done together with AP test and spermatozoa examination to identify evidence of rape.

CONCLUSION

Using these three tests together (AP, PSA, and spermatozoa detection) was recommended as a forensic tool for investigations of vaginal swabs of the rape victims.

Evaluation of semen detection in vaginal secretions: comparison of four methods

PROBLEM

To determine the best method to detect semen in human vaginal secretions.

METHOD OF STUDY

Vaginal secretions from 302 pregnant women at mean 11.8 weeks' gestation were analyzed. Semen detection was assessed with: (i) measurement of total prostate-specific antigen (PSA), (ii) acid phosphatase activity, (iii) microscopic measurement of spermatozoa on Gram stain, and (iv) self-reported sexual intercourse in the past 2 days. Sensitivity and specificity were calculated for each technique in comparison with PSA levels.

RESULTS

A total of 119 (39.4%) women had a detectable PSA. Compared with measurable PSA, the sensitivity and specificity for other methods were: acid phosphatase (26.9%, 98.4%), Gram stain (36.1%, 98.4%), and self-report of intercourse in the past 48 hr (41.9%, 88.8%).

CONCLUSION

Compared with PSA levels, commonly used assays for recent semen exposure are inaccurate. This inaccuracy may affect the results of studies, which measure vaginal immune factors like cytokines or retrieve DNA from vaginal specimens.

Rapid detection of sperm: comparison of two methods

Sperm detection can be an important factor in confirming sexual assault in cases of rape. This paper compares two biochemical methods used in forensic medicine: the first detects the presence of zinc, the second detects acid phosphatase activity. The population studied was composed of 174 consenting women seen at the Male Infertility Center in Toulouse, France. The date of their last sexual intercourse was known accurately. Cytology was the reference test to confirm the presence of sperm in the vaginal samples. We studied the sensitivity, specificity, and positive and negative predictive value of the two biochemical methods. Acid phosphatase detection was the most valuable technique, but its use is limited in time. The zinc test gave disappointing results in our study and does not seem to be a useful reference method for the forensic physician.

Persistence of spermatozoa and prostatic acid phosphatase in specimens from deceased individuals during varied postmortem intervals

The survival of spermatozoa and the persistence of prostatic acid phosphatase has been an area of interest for investigators of sexual assault. However, not much documentation exists concerning the examination of a deceased individual with regard to the postmortem interval and presence of such evidence. The authors reviewed cases referred to the medical examiner's office during a 10-year period. During this time, 199 cases were both autopsied and examined for sexual assault. In particular, these examinations included procurement of swabs for Papanicolaou staining of smears and for quantitation of prostatic acid phosphatase. Most of the victims were female, although a few were male. In the majority of cases, the swabs for smears and prostatic acid phosphatase were taken from oral, vaginal, and anorectal areas in females and oral and anorectal areas in males. The smears all were stained with the routine Papanicolaou stain, and intact spermatozoa and spermatozoan heads were sought. The prostatic acid phosphatase was analyzed by the microparticle enzyme immunoassay method and reported as ng/ml. A level of greater than 100 ng/ml was considered positive. The cases were analyzed with respect to postmortem interval; presence or absence of intact spermatozoa or spermatozoan heads; presence of an elevated prostatic acid phosphatase; body location of the specimen; the time of year; location of the victim; and physical injury (anogenital) of sexual assault. The authors hope that by examining the laboratory evidence of sexual assault, a correlation can be drawn between the presence or absence of such evidence and the aforementioned variables.

Trichomonad invasion of the mucous layer requires adhesins, mucinases, and motility

BACKGROUND/OBJECTIVE

Trichomonas vaginalis, the causal agent of trichomonosis, is a flagellated parasitic protozoan that colonises the epithelial cells of the human urogenital tract. The ability of T vaginalis to colonise this site is in part a function of its ability to circumvent a series of non-specific host defences including the mucous layer covering epithelial cells at the site of infection. Mucin, the framework molecule of mucus, forms a lattice structure that serves as a formidable physical barrier to microbial invasion. The mechanism by which trichomonads traverse the mucous covering is unknown. Proteolytic degradation of mucin, however, may provide for a mechanism to penetrate this layer. The goal, therefore, was to determine how trichomonads cross through a mucous layer.

METHODS

Secreted trichomonad proteinases were analysed for mucinase activity by mucin substrate-sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The importance of trichomonad mucinases for traversing the mucous layer was examined on an artificial mucin layer in invasion chambers. Adherence to mucin and tissue culture cells was measured using a microtitre plate assay.

RESULTS

Trichomonad isolate 24402 secreted five proteinases when incubated in PBS. All five proteinases were shown to possess mucinase activity. These mucinases were able to degrade bovine submaxillary mucin and to a lesser extent porcine stomach mucin. These enzymes were active over a pH range of 4.5-7.0 and were inhibited with cysteine proteinase inhibitors. Furthermore, T vaginalis was shown to bind to mucin possibly via a lectin-like adhesin. Adherence to mucin was increased threefold when parasites were grown in iron deficient medium. Adherence to soluble mucin prevented attachment to HeLa cells. Proteinase activity, adherence, and motility were required for trichomonads to traverse a mucin layer in vitro.

CONCLUSIONS

These results show that trichomonads can traverse the mucous barrier first by binding mucin followed by its proteolytic degradation. The data further underscore the importance of trichomonad proteinases in the pathogenesis of trichomonosis. Finally, this study suggests that interference with trichomonad mucin receptors and proteinases may be a strategy to prevent colonisation by this parasite.

Vaginocervical cytology in victims of sexual assault

To investigate the role of vaginocervical smears in alleged victims of rape, we reviewed the findings in 4,220 consecutive rape victims between the years 1982 and 1989. These rape victims showed a slight increase in cellular abnormalities (1.18% vs. .93%) when compared to a group of 17,187 routine smears from an indigent population in 1989. While the differences in the spectrum of cellular abnormalities were not statistically significant, the increase in abnormal smears is remarkable because of the younger age distribution and lower risk factors for cervical cancer in this group of rape victims (41% of the victims were never seen at our institution before their evaluation for alleged rape and were most probably of higher socioeconomic status and at lower risk for cervical cancer than the indigent population served at our hospital). This finding may reflect the low incidence of vaginocervical cytology screening among the general population of which rape victims are a random sample. Fifty-seven percent of the rape victims with cellular abnormalities who were also regular patients at our hospital returned for follow-up by appropriate repeat smears or biopsies. This was lower than the 95% general follow-up rate of vaginocervical smear abnormalities among the rest of the population screened at our hospital. We detected spermatozoa in 56% of the smears from victims who were examined within three days of the alleged sexual assault. Cytology adds to the criminal investigation of rape cases as we detected spermatozoa in four of 16 semen-negative cases from a random sample of 53 cases evaluated by the state crime lab.

Child sexual abuse: the emergency department response

Each child who presents with a suspicion of sexual abuse must have immediate access to a complete medical evaluation performed by a competent and knowledgeable examiner. This evaluation should include, at a minimum, a history, a complete physical examination with a detailed genital examination, treatment of identified medical problems, and collection of evidence. It is not appropriate to perform a cursory examination simply because there was a time delay between the abuse and the examination or because the history is suspect. Each sexual abuse workup must be medically and forensically complete. In addition, each child presenting with suggestive complaints should have sexual abuse strongly considered in the differential diagnosis. A report to the appropriate social and legal agencies is indicated even if the suspicion cannot be confirmed. If sexually abused children are to be examined in hospital emergency departments, a protocol should be developed to ensure rapid, thorough, uniform, and caring evaluation. With planning, preparation, and education, most current inadequacies in the emergency medical assessment of sexually abused children can be resolved so that child victims receive sensitive and comprehensive medical care.

Clinical findings and legal resolution in sexual assault

Female sexual assault victims who received medical evaluation at Detroit Receiving Hospital from July to December 1980 and were seen by the Rape Counseling Center (RCC) were evaluated. Data were abstracted from the emergency department record, RCC file, and gynecology clinic; 372 patients were evaluated. One hundred twenty-seven patients (34%) were given DES, including 17 women who had been raped at least once before. Data regarding DES dosage were available only on 34 patients, with 27 stating they took the entire course; 5, an incomplete course; and 2 refusing to answer. DES is still approved for post-coital contraception in rape. However, if there is one major concern about its administration, it is that close follow-up be provided to anticipate or eliminate complications, especially those associated with inadvertent pregnancy. The extremely poor medical follow-up, the surprising lack of an "appropriate chief complaint" when follow-up does occur, the large number of sexual assault victim repeaters in an inner city population, and the socioeconomic and demographic characteristics of an urban, inner-city sexual assault victim population which make it impossible to determine the effectiveness of DES are strong arguments for the severe restriction of use of DES in the urban, inner city setting. There is no need for pretreatment GC cultures or VDRL assays. Patients should be treated in conformity with current CDC recommendations. Where a rape counseling center is available, it is suggested that the unit assume close and direct responsibility of directing patients for medical follow-up, regardless of emergency department treatment.