Biomedical subjects
Publications and source records attributed to B L Schmidt.
We present two cases of massive gingival enlargement and osteolysis of alveolar bone in a 30-year-old female and a 36-year-old male. The etiology could not be established in either case. Histologically, both lesions contained hyperplastic fibrous connective tissue and intense plasma cell infiltrates. Both patients responded well to extensive gingivectomy, extraction of all teeth, and alveoplasty.
A total of 359 sera of untreated patients with syphilis were examined by three methods for the detection of Treponema pallidum specific IgM antibodies, the 19S-IgM-FTA-ABS test, the IgM solid phase haemadsorption assay (IgM-SPHA), and the IgM Captia assay. The results were compared and evaluated. In primary syphilis, the 19S-IgM-FTA-ABS and IgM-captia yielded reactive results in all patients, whereas only 40% were positive in the IgM-SPHA; the corresponding values for early latent syphilis wee 96.0%, 89.8% and 73.1%, respectively. In secondary syphilis, the reactivity of one serum out of 27 was missed by IgM captia and that of another, by the IgM-SPHA. Mean values (ELISA units = extinction/cut-off) of IgM-captia were higher in primary (2.25) than in secondary syphilis (1.70). In neurosyphilis, only the IgM-SPHA test detected reactivity in all sera, sensitivity for 19S-IgM FTA-ABS and IgM-Captia was 50.0% and 23.1%, respectively. Specificity of the IgM-Captia test results, determined in 386 sera, was 91.2%. The results of specific IgM tests are essential in the diagnosis of congenital syphilis as well as in the recognition of reinfection; they indicate the need for treatment and are useful in the assessment of the effectiveness of therapy.
The structure of the submental platysma muscle was evaluated in 20 preserved cadavers. Four distinct patterns were identified, depending on the pattern of merging of the right and left platysma bundles. Fifteen percent of cases showed a complete platysma diaphragm submentally, while in the other 85% there was some degree of midline dehiscence. In the 85% of cases where right and left fibers merged or crossed to form a V or U shape, the apex of the V or U was measured relative to the chin point. The distance between right and left fibers was measured at two locations posterior to the chin point. The width of the midline dehiscence (when present) was 6-24 mm (mean 11.8 mm) 1 cm posterior to its apex and 10-44 mm (mean 20.00 mm) 2 cm posterior to the apex. The wider and more divergent the dehiscence and the more U-shaped the dehiscence between left and right platysma bundles, the greater may be the tendency to a "turkey gobbler" deformity with inadequate medial support for the skin and subcutaneous tissues.
A solution hybridization assay using acridinium ester labelled probes is described for detection of amplified HIV-1 DNA segments. Amplification was achieved by 30 cycles of the polymerase chain reaction using SK38/SK39 primers specific for a constant region of the HIV-1 gag region together with HLA DQ alpha primers as internal control. Discrimination between hybridized and non-hybridized probes by differential hydrolysis resulted in a three log reduction of the chemiluminescence signal of the non-hybridized probe within 6 min without significant changes in the hybridized probes due to protection of the acridinium ester to hydrolysis by intercalation formation. Chemiluminescence was measured by a two-step-injection method with hydrogen-peroxide and NaOH. About 50 attomols of HIV-1 gag DNA could be detected. Chemiluminescence results, given in relative light units (RLU) of 159 HIV-1-infected patients (range 4013-458319) showed clear discrimination from 64 noninfected control samples (range 838-1477) (cut off 2000 RLU). Comparison with parallel detection of amplified products with autoradiography (32P) and ethidium bromide-stained agarose gels or a p24 antigen ELISA demonstrated better sensitivity and reproducibility of the chemiluminescence assay. The time required for the assay, including measurements, is less than 30 min, which allows reporting 'PCR results' on the same day.
The polymerase chain reaction (PCR) allows the detection of minimal amounts of DNA segments, and thus is used for the laboratory diagnosis of HIV (human immunodeficiency virus). In the present study a solution hybridization assay using acridinium ester-labelled probes was applied for detection of amplified HIV-1 DNA segments. Amplification was achieved by 30 cycles of the polymerase chain reaction using SK38/SK39 primers specific for a constant region of the HIV-1 gag region. Amplified products were hybridized with acridinium phenyl ester-labelled probes and measured by chemiluminescence. All of 163 blood samples obtained from HIV-infected patients (CDC II-CDC IV) were reactive, while autoradiography with a 32P-labelled SK19 probe only detected 146 patients (89.5%). The combination of PCR with chemiluminescence avoids the use of radioactive material and is sensitive and quick, allowing the "PCR results" to be reported on the same day.
We briefly describe the principal techniques of antigen detection and discuss the pros and cons of routine screening and conformation assays. Regarding the differentiation of HIV 1 and HIV 2 infection, synthetic peptides corresponding to the antigenic epitopes of gp36 (HIV 2) and gp41 (HIV 1) yielded the best results. Commercially available antigen tests are relatively insensitive. New techniques, such as the polymerase chain reaction, allow the dedection of viral DNA in one infected cell out of 100,000 non-infected cells. However, since these methods are based on nucleic acid probes, they are rather laborious and cannot replace antibody tests; but they may be of use for early identification of HIV-infected infants or for the confirmation of the acute phase of the infection (CDCI). With regard to early prognosis--i.e. up to 2 years before the development of clinical symptoms__the following markers have been found useful: neopterine, beta-2-microglobulin, the lymphocyte subsets CD4, CD8, Leu2+7+, activated T-cells, as well as the decrease of antibodies against p31, p24 and p17.
Serological testing aimed at the detection of antibodies against the human immunodeficiency virus (HIV) is now performed throughout the world to screen stored blood for transfusion, for the diagnosis of HIV infection and of AIDS, and to determine the prognosis of AIDS patients. The present report, based on 258,090 serum samples screened for HIV antibodies, gives an overview of the theoretical and practical aspects of both modern screening methods and confirmation tests for HIV1 and HIV2, the demonstration of serological antigen and IgM, and HIV serology of the cerebrospinal fluid. Knowledge of HIV serology appears to be important for any physician, and in particular for the dermatologist, since HIV infection (like syphilis) can cause a variety of dermatological manifestations mimicking other dermatoses.
AIDS serology is of worldwide importance for the diagnosis of HIV-infection and AIDS, for conducting epidemiological studies, for the control of blood donations and blood products and for the determination of infectivity and prognosis in AIDS patients. In future serological methods may be of importance for the management of anti-HIV-therapy. Screening methods, such as ELISA and hemagglutination assays and confirmatory tests (Western blot and immunofluorescence) nowadays offer clear cut and reliable results. Discussions on the "AIDS-tests" in the past have not been free from emotions; from the medical standpoint, however, it is for sure that the affected patient should know about his infection, in order to protect himself as well as others. The physician must know the HIV-status of his patient, in case major diagnostic or therapeutic measures, such as operations are to be performed or drugs are going to be prescribed, which may influence the immune system. The present paper describes the AIDS serologic methods based upon 197.956 tests performed in our laboratories, HIV-IgM-diagnostic methods, HIV-status in the cerebrospinal fluid and the serologic diagnosis of HIV 2-infection are discussed. In future the serologic control and the serologic prognosis parameters will gain major importance for monitoring AIDS-patients before and under treatment. This paper describes the methods (virus specific antibody tests; tests for the demonstration of immune system activation; immunstatus) which might be used for this purpose.
145.990 sera obtained from AIDS-risks groups, hospitalized patients, blood donors etc. were tested for the presence of antibodies against the AIDS-Virus (HIV:Human Immunodeficiency Virus). All sera were submitted to ELISA screening. Sera with positive and questionable results were submitted to two independent confirmatory tests (Western Blot and immunofluorescence). In case of discordant confirmatory tests sera were additionally tested with the Abbott anti-HIV envelope/anti HIV core ELISA. The results of the present study demonstrate: 1. HIV serology has been definitely improved during the last year due to the development of high quality reagents. 2. Provided skilled and trained personnel the combined use of HIV confirmatory tests (Western Blot and immunofluorescence) does not give false negative or false positive results. 3. The results of both confirmatory assays may not always be interpretable ("problem sera"); this occurs more often with the Western Blot technique than with immunofluorescence. 4. Discrepant results in confirmatory tests necessitate the evaluation of many additional tests as possible. Such persons or patient should be further controlled serologically and clinically. 5. Checking the "problem sera" for antibodies against HTLV I gave only one single positive result in a Japanese.
The diagnostic value of different laboratory methods in detecting Chlamydia trachomatis infections in high risk groups was analysed. The efficiency of a direct specimen test was compared with serology (IgG and IgM ELISA) and culture in L929 cells, stained either with fluorescein conjugated monoclonal antibodies or with iodine. Patients (no. = 1041) with localized genital infections attending a STD clinic, sexual contacts and patients with ascending infections from urological and gynecological clinics were examined. Chlamydia trachomatis was detected in 225 patients: 210 (93.3%) were reactive in the direct test (smears stained with monoclonal antibodies), whereas culture missed only 5 (sensitivity 97.8%) when stained by the same method. Cultures stained with iodine produced the lowest recovery rate (73.8%), but this rate increased to 80.9% when a second passage was performed. In addition the prevalence of Neisseria gonorrhoeae, Mycoplasma hominis, Ureaplasma urealyticum, Candida albicans and Trichomonas vaginalis was investigated. In patients with non-gonococcal urethritis (no. = 331) and cervicitis (no. = 353), Chlamydia trachomatis was isolated in 32.3% and 12.8% respectively. However, this pathogen could be isolated in only 3 (15.8%) out of 19 patients with epididymitis and 15 (14%) out of 107 patients with adnexitis, although 66.7% and 93.3% respectively had specific IgG antibodies. Specific IgM could by detected with a sandwich ELISA in patients with adnexitis (46.7%), epididymitis (33.3%), cervicitis (22.2%), non-gonococcal urethritis (14%) and in the sexual partners of patients with genital infections (35.7%). The direct specimen test with monoclonal antibodies is the method of choice for the diagnosis of a C. trachomatis infection in patients with urethritis and cervicitis.(ABSTRACT TRUNCATED AT 250 WORDS)
1,032 sera of diverse origin (AIDS risk groups, prostitutes, inpatients, blood donors) exhibiting a positive HIV (HTLV III/LAV) ELISA result (Organon and/or Abbott) were investigated with different HIV confirmation assays (Western blot, WB; immunofluorescence, IF; competitive enzyme immunoassay against cloned gp41- and p24-antigen). Sera were finally evaluated as positive if at least two confirmation assays turned out positive (IF and WB; IF and p24, gp41; WB and p24, gp41; IF and WB and p24, gp41). Test results were considered false if the respective finding (IF or WB or p24, gp41) differed from two other confirmatory assays. 1,001 out of 1,032 sera (97%) yielded corresponding results in IF and WB. The remaining 3% of the investigated sera showed false positive, false negative, non-interpretable IF results and non-interpretable WB findings. The present study demonstrates that a positive HIV test should be confirmed by at least two confirmatory tests, one of which should be the WB. Non-corresponding results in confirmatory tests necessitate a third test system.
Tissue culture for Chlamydiae requires facilities that are not generally available, are costly and require 3 to 7 days for completion. With the introduction of specific monoclonal antibodies Chlamydia trachomatis can be recognized within 30 minutes. Therefore the direct specimen test should be performed as the method of choice. In complicated, ascending forms of the disease requiring special methods for sample collection (e.g. laparoscopy), serology may aid in the diagnosis of a Chlamydia trachomatis infection.
The first human retroviruses have been discovered during the past seven years. They cause two diseases which involve disturbances of the growth of the T4-lymphocyte. This target cell type, which is central to the regulation of the immune system is induced by human T-lymphotropic virus type I (HTLV-I) to excessive proliferation (leukaemia) and by HTLV-III/LAV (lymphadenopathy associated virus) to premature death (acquired immune deficiency syndrome [AIDS]). Both also seem to be indirectly involved in several other disorders. The genetic structures of these retroviruses and the mechanisms by which they usurp host-cell functions are novel among retroviruses. The continuous increase in the number of AIDS cases for whom no effective therapy is currently possible mandates attempts at developing primary prevention by a vaccine. Based on past attempts at developing vaccines against retroviruses, the most feasible configuration will be the glycoprotein linked to its transmembrane protein. Any virus preparation containing nucleic acids could be considered less safe. Potential problems exist in that there is extensive heterogeneity among various HTLV-III isolates, particularly in the env-gene. This fact and the known relationship of HTLV-III to some Lentiviruses suggest that functional antigenic variation could be encountered. The methodology of developing a vaccine against the retroviruses causing AIDS should also be helpful in designing vaccine strategies against human leukaemia and lymphomas caused by other members of this virus family.
A serological study with an enzyme-linked immunosorbent assay using the axial filament of Treponema phagedenis biotype Reiter as antigen was performed on 1899 sera to evaluate the sensitivity and specificity. The sensitivity as compared with the fluorescent treponemal antibody-absorption test (FTA-ABS) and the automated microhaemagglutination assay with Treponema pallidum antigen ( AMHA -TP) was 94.6% and 93.1%, respectively. The specificity was 98.5% compared to both assays. Furthermore, preliminary results for the determination of IgM antibodies with the same antigen are presented. All procedures including dispensing, washing, optical reading and evaluation of results were performed automatically using a newly-developed ELISA processor connected with an electronic surveillance and control device.
SPHA-test was performed on 317 treated and 78 untreated patients with syphilis and partly compared to 19S-IgM-FTA-ABS- as well as VDRL-test. Equivalent results were obtained in a reference laboratory, the correspondence being 94.8 percent regarding SPHA and 95.6 percent concerning 19S-IgM-FTA-ABS. In comparison to 19S-IgM-FTA-ABS, increased numbers of weakly reactive values occurred in SPHA correlating with the Latex-test. Because of its specificity and sensitiveness, SPHA turned out to be superior to VDRL with regard to the control of treatment. The biological significance of weakly reactive SPHA results is still unclear and does not indicate a necessity for therapy.
Serological investigations for the diagnosis of syphilis have been performed in a special subunit at the Department of Dermatology to Lainz Hospital, Vienna, since 70 years. At present 80,000 to 100,000 sera are tested annually. The classical test systems VDRL, TPHA, AMHA-TP and FTA-ABS demonstrate, in particular, the presence of IgG antibodies and are, thus, suitable for the diagnosis of the disease, but do not permit conclusions on the activity of the disease and the actual need for antisyphilitic treatment. The newly developed IgM diagnosis of syphilis with the IgM-SPHA- and the 19S-IgM-FTA-ABS test solve these problems and can be performed even under routine conditions using the methods of solid phase haemadsorption and computerized high pressure liquid chromatography. In addition, the serological diagnosis of neurosyphilis has been worked out by the determination of the TPHA-index and the detection of antitreponemal IgM-antibodies in the cerebrospinal fluid. The relative frequency of latent syphilis infections has increased over the past years and serodiagnosis of syphilis, thus, become more and more important. The availability of five independent test systems has enabled the elaboration of a test profile which keeps the margin of error to below 0.1%. A further method, the ELISA technique is at present under investigation and renders promising results by the use of recently developed reagents.
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Abundant evidence suggests that Treponema pallidum (T.p.) escapes humoral immune defence despite the host produces antibodies early in the infection. Since the serologic responses in syphilis have been studied in detail this paper focuses on the cellular immune mechanisms. For this purpose the leukocyte migration inhibition was investigated in 17 patients in different stages of syphilis. Leukocyte migration inhibition assay was performed before, and 7 days, 3 weeks, 2 mo. and 1 yr after start of treatment. Ultrasonicated T.p. were used as antigen corresponding to 5 X 10(6) to 2 X 10(7) Treponema pallida per ml. Controls without antigen, with addition of Concanavalin. A instead of T.p. and using cells of normal volunteers were run. There was no leukocyte migration inhibition before treatment, suggesting nonexistent or depressed cellular immunity in the untreated syphilitic patient. Significant leukocyte migration inhibition, however, was observed as early as 2 days after start of treatment, being most pronounced after 1 week. Hypothetical circulating blocking factors for cellular immune reactions might be present in the untreated syphilitic patient, which become abolished after therapy. Since stimulation with Con A of syphilitic leukocytes gave normal results even before treatment in the syphilitic patient, there might be a specific block of leukocyte migration inhibition against T.p.