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Biomedical subjects

E Pretorius

Publications and source records attributed to E Pretorius.

53 records · Page 3Linked to original sources
PubMed1985

Antibodies to spermatozoa: XI. The use of immunobeads for the detection of sperm antibodies in serum.

Two procedures were developed and evaluated that used either larger or smaller volumes for the detection of sperm antibodies in serum by means of an indirect immunobead test (IBT). The immunobeads, coated with rabbit antibody to each of the major human immunoglobulins (IgG, IgA, or IgM), were mixed with preparations of donor sperm, onto which antibody had been coated by passive transfer from various serum samples. The results of the IBT could be evaluated in various ways: (1) positive or negative; (2) if positive, whether binding is to the tail, the head, or the head and tail of the sperm cells; (3) if positive, whether binding is by IgG, IgA, or IgM. The diverse IBT results were obtained from a group of 50 serum samples; these sera were also tested by two sperm agglutination methods; the gelatin agglutination test (GAT) and the tube-slide agglutination test (TSAT). There was an excellent agreement between the IBT and the GAT; it was not as good between the IBT and the TSAT. However, considering both agglutination methods together, 90% of the IBT-positive sera were agglutination-positive. In terms of morphological sites, tail binding occurred in 27 of 31 sera, head binding in 12 of 31 sera, and head-tail binding in 15 of 31 sera. The number with tail binding was very close to the number that were GAT-positive (26). As for the immunoglobulins, the most frequent class was IgG. IgA was 83% as frequent and IgM was only 25% as frequent as IgG.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗
PubMed1985

Important semen parameters during postcoital testing.

One hundred and sixty-two females who attended our infertility clinic were selected according to the quality of their cervical mucus. Only mucus of extremely high quality was used in the study to determine the influence of different semen parameters on the postcoital test results. All mucus samples were evaluated 8 h following coitus. The results of the postcoital tests were divided into group I (less than 7 spermatozoa per 400 X magnification) and group II (greater than 7 spermatozoa per 400 X magnification). The results of the statistical analysis indicated the order of importance of the different semen parameters during postcoital testing. By using the stepwise discriminant analyses, it was calculated that the sperm concentration and forward progression rate of the spermatozoa are discriminating factors between the two groups.

Cervix Mucus↗
PubMed1984

IgG-coated latex particles and the identification of sperm antibodies.

The identification of sperm surface antibodies forms an integral part of the investigation of male infertility. We tested 39 randomly selected men for the presence of sperm surface antibodies by using IgG-coated latex particles during mixed antiglobulin reaction (MAR) testing. The latex MAR test results were compared with the red blood cell MAR and the Friberg sperm agglutination test results. The latex MAR is a sensitive indicator and can be employed by physicians to identify the presence of sperm antibodies on the sperm surfaces.

Antibodies↗
PubMed1984

Second pregnancies among immunologically infertile women: a preliminary report.

Two females with sperm antibody activity in their blood serum and cervical mucus were treated with high dosages of methylprednisolone. Both patients became pregnant during therapy. Following the birth of their first offspring, one was treated with steroids and the other conceived without steroids in order to establish their second pregnancies. The sperm antibody activity showed a sharp decline in the blood serum and cervical mucus during therapy. The response of the females showed drastic modification in the antibody activity in that the females revealed a complete disappearance or a significant decrease in their initial sperm antibody reactions after treatment with high dosages of steroids.

Antibodies↗
PubMed1984

Lymphocyte transformation rates of homosexual men in presence of seminal plasma.

The peripheral lymphocytes of eleven healthy homosexual men and six heterosexual males were used in microlymphocyte culture systems to compare their transformation rates in the presence of PHA-M. Two homosexual men were randomly selected from the group to investigate the influence of seminal plasma fractions on their lymphocytes. The seminal plasma fractions were obtained from heterosexual normozoospermic men. Seventy two percent of the homosexual T-cell responsiveness to PHA was inhibited compared with the lymphocytes of the heterosexual men. The lymphocytes of the homosexual male seem to be less sensitive for the inhibition components present in seminal plasma.

Adult↗
PubMed1984

Sperm selection capacity of cervical mucus.

Seventeen couples who attended the Infertility Clinic for routine fertility investigations were used in the study. Complete morphological examinations were performed on the ejaculates and cervical mucus samples following coitus in order to determine the morphological selective capacity of the mucus. It was concluded that both the motility of the spermatozoa and ability of the cervical mucus to select morphological abnormal spermatozoa contributed to the high percentage of normal spermatozoa present in the cervical mucus during the post coital test.

Cervix Mucus↗
PubMedDate not supplied

Detection of villous conidia of Conidiobolus coronatus in a blood sample by scanning electron microscopy investigation.

Conidiobolus coronatus is a major insect pathogen belonging to the fungal order Entomophthorales, causing a rare subcutaneous infection of the nasofacial region, resulting in swelling of predominantly the nose, mouth, and perinasal tissue. Later in the course of the infection firm, painless, subcutaneous nodules develop that are attached to the underlying tissues but not to the skin. No morphological studies are available in the literature on the morphology of C. coronatus in vivo and all morphological studies have been conducted on in vitro cultures. Here the authors report on the ultrastructural pathology as seen with a scanning electron microscope (SEM) of villous conidia of C. coronatus, detected in a 37-year-old woman who presented to the casualty department at Pretoria Academic Hospital, South Africa with left-sided facial pain and headache. The diagnosis of C. coronatus was confirmed by LightCycler real-time flourescence PCR technique. Research shows that typically diagnosis of the pathogen is established only on histological examination, and in over 85% of cases cultures for the causative organism is negative. This pathogen has not previously been found in a blood sample and the authors present for the first time the morphology of C. coronatus in blood using the SEM.

Adult↗
PubMedDate not supplied

Structural changes in the fibrin network of a pretoria family with dysfibrinogenemia: a scanning electron microscopical study.

Inborn errors of fibrinogen structure are by definition congenital dysfibrinogenemias. The present study assesses the scanning electron microscope characteristics in the fibrin network morphology in a Pretoria family with an amino-acid substitution defect at position 139 on the gamma chain where the cystein residue is replaced by tyrosine. This anomaly results in a disturbance of the interchain disulfide bond, an ultrastructural defect that interferes with fibrin polymerization. Clinical manifestations showed that 2 of the family members presented with thrombosis, as well as a bleeding tendency, while 2 were asymptomatic. Fibrin clot analysis revealed that in all 4 family members a tighter fibrin network with increased fibrin density and reduced pore size was present. The fibers showed a "stellate" appearance where they converge and some were fused longitudinally to form sheets of "matted" fibrin. Furthermore, there was a conspicuous absence of platelets. Fibrin dysfunction is associated with the development of vascular complications, while proneness to the formation of tight and rigid fibrin networks is independently associated with thrombotic disease. Although this does not explain the proneness of some family members who present with excess bleeding, bleeding might be related to the defective binding of fibrin to activated platelets, resulting in inadequate prothrombotic stimulus that is normally enhanced by the second wave of thrombin generation, which occurs on the platelet surface.

Afibrinogenemia↗
PubMedDate not supplied

Ultrastructural investigation of Zimmermann-Laband syndrome.

Zimmermann-Laband syndrome (ZLS) is a very rare autosomal dominant inherited condition characterized by 3 major clinical findings of which gingival hyperplasia are always present. The great heterogenicity of the syndrome is illustrated by the numerous variable clinical findings described in the literature. The purpose of the study was to examine a patient diagnosed with ZLS and to describe possible new characteristics of this rare syndrome, including the ultrastructural morphology using a transmission electron microscope (TEM) of the gingival and dermal fibroblasts. The ultrastrucutral morphology as has not previously been described in the literature. Tissue was collected from the alveolar ridge and skin of the forearm for TEM. TEM studies indicated the presence of prominent fibroblasts situated among numerous regular dense connective tissue bundles. Genetic analysis showed a new chromosomal insertion, ins(12;8)(p11.2;q11.2q24.3), suggesting that the gene responsible for the syndrome lies on chromosome 8.

Abnormalities, Multiple↗
PubMedDate not supplied

Anaerobic bacteremia and necrotizing fasciitis in a patient with Crohn's disease.

Crohn's disease is a chronic, granulomatous disease that affects the gut that is frequently treated with immunosuppressive therapy. Infectious complications are common and are usually related to the transmural nature of the inflammation, frequently manifesting as abscesses or perianal sepsis. Necrotizing fasciitis has not been reported in Crohn's disease. A case of a fatal necrotizing fasciitis in a patient with Crohn's disease after gut biopsies and corticosteroid therapy is reported.

Adult↗
PubMedDate not supplied

The immunobead technique: an indicator of disturbed sperm cervical mucus interaction.

A group of 20 couples with repeatedly poor post coital tests (PCT's) where no coital disorders or cervical mucus abnormalities were present, were included in the study. The results of the Direct Immunobead (IB) and Tray-agglutination tests were compared with the results of the sperm-cervical-mucus-contact (SCMC) and post coital tests (PCT's) of each couple in order to determine the sensitivity, specificity and predictive value of the Direct IBT as a screening test for sperm antibodies. The positive predictive value of the IBT was 80%. It was also clear that a strong positive SCMC-T result correlated with agglutinating antibodies in the semen or seminal plasma. In conclusion, the IBT is a sensitive, specific and predictable test for sperm antibodies.

Cervix Mucus↗
PubMedDate not supplied

The predictive value of the postcoital test for auto- and isoimmunity to spermatozoa.

Twenty eight infertile couples with sperm antibodies were used in the study. The immunologic factors in the husbands and wives were compared with the results of the post coital test. The results of the study showed that the post coital test had a predictive value of 75% for male auto-immunity to sperm while only 37% of the females with sperm antibodies had a poor post coital test. It was concluded that the post-coital test is an important screening predictor of auto-immunity to spermatozoa.

Antibodies↗