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Biomedical subjects

K Ritter

Publications and source records attributed to K Ritter.

At least 55 records · Page 3Linked to original sources
PubMed1993

Cationic glycoproteins in sera of patients with acute infections identified as kappa light chain glycosylated IgG.

In half of the sera from patients with acute bacterial infections and 15% of the sera from patients with acute viral infections glycoproteins were found that form a scalariform pattern in the cationic range upon isoelectric focusing. The cationic glycoproteins appeared with the clinical illness. After subsidence of the symptoms they disappeared within 4 to 6 weeks. The proteins were identified as immunoglobulin G (IgG) by determination of the NH2-terminal amino acid sequence. Remarkably, these IgG only contained light chains of the kappa type with high proportions of carbohydrates. Both, N-glycosidic- and O-glycosidic-bound glycans were present. The glycosylated light chains may render the cationic IgG multireactive. Thus, it may be part of an early nonspecific immune defense mechanism.

Acute Disease↗
PubMed1992

Generation of macaque B lymphoblastoid cell lines with simian Epstein-Barr-like viruses: transformation procedure, characterization of the cell lines and occurrence of simian foamy virus.

Two simian Epstein-Barr-like viruses, a rhesus Epstein-Barr virus and Herpesvirus papio, were used to transform B cells from rhesus or cynomolgus macaques. The resulting cell lines exhibited predominantly a B lymphocyte phenotype and expressed Epstein-Barr virus antigens. The majority of B lymphoblastoid cell lines from macaques, which were seropositive for simian foamy virus, developed giant cells in culture. The cytopathic agent was identified as a foamy virus and was transmissible to human embryonal fibroblasts. Treatment of cell cultures with AZT abolished giant cell formation.

Animals↗
PubMed1992

Successful plasmapheresis in corticosteroid-resistant hemolysis in infectious mononucleosis: role of autoantibodies against triosephosphate isomerase.

A 19-year-old girl fell ill with a high temperature and cervical lymphadenopathy. The detection of heterophile antibodies as well as Epstein-Barr-virus-specific antibodies confirmed the diagnosis of infectious mononucleosis. In the course of the infection, the patient developed severe hemolytic anemia with her hemoglobin falling from 14 to 8 g/dl. High-dose corticosteroid therapy did not stop hemolysis; this could only be achieved by seven plasmapheresis sessions. Antibodies against triosephosphate isomerase (TPI) and the blood group marker 'i' were found in the patient's serum. Anti-i cold agglutinins were not active at 37 degrees C, whereas antibodies against TPI caused increased 51Cr release from marked patient's erythrocytes in vitro. Plasmapheresis removed the autoantibodies effectively and stopped the hemolysis. After 8 weeks, the patient gradually recovered.

Adrenal Cortex Hormones↗
PubMed1991

Affinity purification of antibodies from sera using polyvinylidenedifluoride (PVDF) membranes as coupling matrices for antigens presented by autoantibodies to triosephosphate isomerase.

Polyvinylidenedifluoride (PVDF) membranes covered with antigen can be used for affinity purification of antibodies from sera. These antibodies serve as an appropriate substitute for monoclonal antibodies when performing cytological and analytical experiments with the respective antigen. The usefulness of this method is demonstrated with the purification of IgM autoantibodies produced against human triosephosphate isomerase in acute Epstein-Barr virus infection. Compared with the original serum, the specific activity of the purified antibodies was up to 1400-fold higher, and the recovery of the anti-triosephosphate isomerase activity between 25 and 33%.

Animals↗
PubMed1991

Immunoblot for densitometric estimation of antibodies (IDEA): a useful method for quantification of intrathecally produced antibodies against individual antigens in infectious diseases of the central nervous system.

Intrathecally produced antibodies specific for the infectious agent can be shown by immunoblot. A quantification is practicable by titration. Densitometric evaluation of the immunoblot by a new technique, IDEA (immunoblot for densitometric estimation of antibodies), does not only render titration unnecessary, but also has the advantage of presenting the differentiated local immune response against individual antigens of the infectious agent. Preliminary studies for the densitometric evaluation were performed with a measles virus immunoblot which had been developed with a cerebrospinal fluid (CSF) sample of a patient suffering from multiple sclerosis containing high antibody titers. A peroxidase-labeled anti-immunoglobulin antibody had been added. The intensity of the color reaction on the membrane dependent on the antibody concentration follows a saturation kinetics comparable to the Michaelis-Menten kinetics in enzymology. Thus, indices for the intrathecal antibody synthesis of each individual viral antigen can be calculated by taking the permeability of the blood-CSF barrier into consideration. This method is illustrated in a patient with zoster meningoencephalitis.

Antibodies, Viral↗
PubMed1990

[Infectious mononucleosis: hemolysis by autoantibodies against triosephosphate isomerase].

Generalized adenopathy and splenomegaly developed in an 18-year-old youth after a severe tonsillitis followed by headache, tiredness and weight loss for several weeks. Infectious mononucleosis (acute Epstein-Barr virus infection) was confirmed by the demonstration of virus-specific antibodies. A reticulocytosis (24%), decreased haptoglobin concentration (0.6 mg/dl) and increased lactate dehydrogenase activity (657 U/l) indicated marked haemolysis. The bone marrow showed increased erythropoiesis with abnormal maturation. Antibodies against triosephosphate isomerase and against blood group marker "i" were demonstrated in the patient's serum. Antibodies against triosephosphate isomerase from the patient's serum were purified by affinity-chromatography. They strongly reacted with the patient's erythrocytes and under complement activation induced an increased 51Cr liberation from marked erythrocytes. No corresponding effect of anti-i-antibodies was noted at 37 degrees C. With the fall in antibodies against triosephosphate isomerase the haemolysis receded and the patient became free of symptoms after 7 weeks.

Adolescent↗
PubMed1990

Autoantibodies against triosephosphate isomerase. A possible clue to pathogenesis of hemolytic anemia in infectious mononucleosis.

In sera from patients with acute EBV, infection and the clinical symptoms of infectious mononucleosis antibodies of the Ig class M were found that are directed against two cellular proteins. The molecular mass of these proteins was determined to be 29 (p29) and 26 kD (p26), respectively, in SDS-PAGE. P29 was identified as part of the glycolytic enzyme triosephosphate isomerase (TPI) by comparison of the NH2-terminal amino acid sequences. A purified antibody against TPI induces a 51Cr release from human erythrocytes. Possibly, anti-TPI causes hemolysis, which is an infrequent but serious symptom of infectious mononucleosis.

Amino Acid Sequence↗
PubMed1990

Fine specificities of antibodies in sera and cerebrospinal fluid in herpes virus infections of the central nervous system as detected by the antigen variable immunoblot technique.

Applying the immunoblot technique a sensitive and specific method was developed for the detection of intrathecally synthesized antibodies against individual specific proteins that are antigens of various infectious agents causing encephalitis. Paired serum and cerebrospinal fluid (CSF) samples from five patients with herpes virus infections of the central nervous system (CNS) (three herpes simplex virus encephalitis, one varicella zoster virus encephalitis, one zoster ganglionitis) were investigated for the presence of locally produced IgG against the electrophoretically separated antigens of herpes simplex virus (HSV), varicella zoster virus (VZV) and human cytomegalovirus (HCMV), as well as for IgM antibodies in one case of HSV encephalitis. In two cases (HSV encephalitis and VZV encephalitis) four and one antibody, respectively, were found that were synthesized intrathecally only. In the other cases the patterns of sera and CSF antibodies were similar, the CSF antibodies showing an all-over stronger reaction, at identical IgG concentrations. In contrast to the conception of a 'limited heterogeneity' of intrathecal antibody synthesis in encephalitis, we thus found an 'expanded heterogeneity' of the intrathecally synthesized antibodies in comparison to the corresponding serum antibodies.

Adult↗
PubMed1990

Countertransference in the movies: effects on beliefs about psychiatric treatment.

This study examined the effect of viewing the movie Lovesick on college students' beliefs about countertransference and psychiatric practice. Consistent with the concerns of Gebbard and Gebbard (1985) that the public may develop erroneous beliefs about psychiatry from watching such movies, after seeing the film subjects were more accepting of sexual behavior between analyst and patient and were cynical about the motivation of the mental health professions in prohibiting such behavior.

Adult↗
PubMed1990

IgM autoantibodies against two cellular antigens always appear in acute Epstein-Barr virus infection.

In the course of infectious mononucleosis, IgM antibodies are formed against 2 proteins present in nucleated and non-nucleated vertebrate cells. Antibodies were found in sera of all patients suffering from acute Epstein-Barr virus infection. In 40% of the cases these antibodies are monoclonal. Persons with former Epstein-Barr virus infection were negative. The antibodies against the 2 proteins were first detected in Raji cells with an IgM-specific immunofluorescence test. The proteins were demonstrated in extracts of different cells and tissues by immunoblot technique. The molecular weight of the proteins measured in SDS polyacrylamide gel electrophoresis was 26 kd and 29 kd, respectively. Their presence in the cells does not depend on the presence of the Epstein-Barr virus genome. The relevance of the new findings concerning diagnostics as well as pathogenetic aspects remains to be established.

Antibodies, Viral↗
PubMed1988

[The so-called "ocular histoplasmosis syndrome"].

The authors describe seven patients presenting with ophthalmoscopic findings typical of "presumed ocular histoplasmosis syndrome." However, no humoral antibodies could be demonstrated. Moreover, the results of skin tests were all negative even after "boostering." Hence, the diagnosis of ocular histoplasmosis had to be ruled out. Tests for listeriosis, lues, leptospirosis, ornithosis, Toxocara canis, toxoplasmosis, Larva migrans, and Candida albicans were also negative. There are evidently other, so far unknown, agents which lead to an ophthalmoscopic picture that mimics ocular histoplasmosis with its typical "punched-out lesions" and central hemorrhagic chorioretinopathy. One of these agents may be Epstein-Barr virus, because two of six patients had increased antibody levels of Epstein-Barr nuclear antigen and early antigen, indicating an active or persistent state of viral infection.

Adult↗
PubMed1986

Cytostatic effect of gangliosides present in the membrane of macrophages.

Stimulated macrophages are known to inhibit the growth of certain tumor cells. Using mouse peritoneal exudates as a source of macrophages and the mastocytoma cell line P815 as the target, the inhibition was found to depend on direct contact between the macrophages and the growing cells. Cytostatic activities were detected in extracts of macrophages as well as in membranes of macrophages bound to substances of low molecular weight. Physical and biochemical characteristics of the cytostatic activity hint toward N-acetylneuraminic acid containing glycosphingolipids (gangliosides). The different macrophage gangliosides were separated by thin-layer chromatography. All types showed cytostatic activity, but the most effective gangliosides were identified as monosialoganglioside GM1 and disialoganglioside GD3.

Animals↗
PubMed1985

Lymphadenopathy and antibodies to HTLV-III in homosexual men. Clinical, laboratory and epidemiological features.

The study provides information on the epidemiology of HTLV-III infection and the lymphadenopathy syndrome (LAP) in 374 German homosexual men. Sexual contacts in the USA and rectal enemas before receptive anal intercourse are the main risk factors associated with virus transmission. HTLV-III seropositivity is significantly correlated with LAP. Prominent clinical signs are infrequent. Immunological and haematological abnormalities are prevalent, and the retrovirus infection is frequently associated with serological markers of other viruses (hepatitis B, herpes group viruses). Lymphadenopathy as a manifestation of HTLV-III infection is discussed within the context of AIDS-related disorders.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Antibodies to adult T-cell leukemia virus (ATLV/HTLV-I) in AIDS patients and people at risk of AIDS in Germany.

A total of 2048 serum samples from Germany were examined for antibodies to adult T-cell leukemia virus (ATLV) structural polypeptides with an enzyme-linked immuno sorbent assay (ELISA) and confirmative immuno precipitation. The origin of the sera samples was: 850 samples taken for virological or protozoal diagnosis; 626 samples from male homosexuals, about 20% of whom had lymphadenopathy syndrome; 164 from hemophiliacs; 184 were from multiple transfused, mostly dialysis patients; 9 from intravenous drug abusers; 182 from suspected cases of acquired immuno deficiency syndrome (AIDS) and 33 from AIDS-patients. In none of these sera did we detect antibodies to ATLV, except in the serum of one patient who had been on hemodialysis for over 11 years. Obviously infection with ATLV or a serologically related agent is very rare in our country and an association with AIDS could not be observed.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Active immunization against hepatitis B: immunogenicity study in homosexual men.

In a group of 238 homosexual men a hepatitis B vaccine developed at the National Reference Center for Viral Hepatitis (Göttingen/Germany) was evaluated. The vaccine was well tolerated. Three intramuscular injections of inactivated HBsAg (subtype ad; 11300 Natl. Units/dose) induced antibody production in 89.7% of the subjects. Four participants exhibited signs of hepatitis B infection. Vaccine recipients younger than 30 years produced higher antibody levels than older vaccinees. More than one half of the subjects who had only anti-HBs (anti-HBc negative) prior to immunization did not show an anamnestic booster response but formed IgM-anti-HBs. Antibody levels were significantly lower in anti-HBs negative/anti-HBc positive recipients than in subjects who had only anti-HBs or no hepatitis B markers. Immunological studies of T and B cell function did not provide conclusive evidence for the underlying cause of the different immune responses.

Adult↗
PubMed1985

Proliferative responses to human cytomegalovirus in lymphocyte cultures of male homosexuals.

29 healthy adults and 32 male homosexuals were investigated for their humoral and cellular immunity against human cytomegalovirus (HCMV). In contrast to 30% of the controls, all homosexuals had HCMV serum antibodies. In addition, 84% of the homosexuals reacted positively in HCMV induced in vitro lymphocyte proliferation as compared to 66% of the controls. The study group also showed significantly higher mean reactivities in the lymphoproliferative response towards HCMV. In the group of homosexuals, a correlation could be established between the humoral and cellular immune reactivity to HCMV.

Adult↗