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Biomedical subjects

G Harms

Publications and source records attributed to G Harms.

70 records · Page 4Linked to original sources

Risk factors for HIV infection in German i.v. drug abusers. Clinical, serological and epidemiological features.

A series of 320 German i.v. drug abusers (32.2% female, 67.8% male) were tested in a cross-sectional study for antibodies against HIV. Seroprevalence increased from 0 in those who discontinued i.v. drug abuse before 1982 to 37.2% in those who stopped injecting drugs in 1985/1986 or who were still addicted. Antibodies to HIV were significantly associated with lymphadenopathy and clinical symptoms (fever, weight loss, diarrhea, fatigue, night sweat, dermal lesions) and with markers of hepatitis A and hepatitis B virus infection. Participants of the study admitted in 92.5% of cases to "needle sharing" and in 83.1% of cases to sexual contacts among drug abusers. Prostitution and drug abuse in prison were significantly correlated with seropositivity. No antibodies to HIV infection were detected in 131 subjects of a control group of household contacts.

Acquired Immunodeficiency Syndrome↗

Simultaneous immunohistochemical demonstration of antigen expression and 5-bromodeoxyuridine incorporation in plastic embedded sections.

In this study a double immunohistochemical staining procedure is described for the simultaneous demonstration of antigen expressing cells and replicating cells in rat thymus. As markers for cell surface antigen expression a monoclonal antibody against Ia-expressing cells (His 19) and a monoclonal antibody against cells of the monocyte-macrophage lineage (ED2) were used. Replicating cells were demonstrated by the incorporation of 5-bromodeoxyuridine (BrdUrd). Tissue pieces were fixed in a periodate-lysine-paraformaldehyde fixative and embedded in glycol methacrylate. To demonstrate Ia-expressing cells or ED2-positive macrophages in plastic embedded sections a digestion with trypsin is necessary. The staining procedure was applied sequentially and was performed with a peroxidase and an alkaline phosphatase labeled reagent yielding respectively a brown and a blue reaction product. Results with this staining procedure on plastic embedded sections of rat thymus, an organ with a high DNA synthesizing capacity, showed incorporation of BrdUrd predominantly in the cortex. ED2-positive macrophages were only found in the cortex. The Ia-positive epithelial reticular cells demonstrated extremely well their stellate form.

Animals↗

Immunohistochemical demonstration of DNA-incorporated 5-bromodeoxyuridine in frozen and plastic embedded sections.

The application of an immunohistochemical method in the detection of replicating cells, that have incorporated 5-bromodeoxyuridine (BrdUrd), was studied on frozen and plastic embedded sections of different rat tissues. Hydrolysis conditions employed in the Feulgen procedure are essential in making the incorporated BrdUrd accessible to the monoclonal anti-BrdUrd antibodies. To demonstrate the incorporated BrdUrd in plastic embedded sections a subsequent etching with xylene and digestion with protease is necessary. Data obtained with this method are completely comparable with those found by the tritiated thymidine method. In comparison with the thymidine method, the BrdUrd method is much less time consuming and does not require precautions in working with radioactivity. The BrdUrd-method enables a more precise localization as is especially shown in the plastic embedded sections.

Animals↗

Immunohistochemical demonstration of FC receptors in rat tissues using immune complexes as ligand.

To demonstrate the presence and localization of Fc receptors, rat liver cryostat sections were incubated with heterologous and autologous immune complexes (ICx) and immunoglobulin (Ig) aggregates. Binding was demonstrated using the immunoperoxidase technique. Autologous and heterologous ICx as well as aggregates from human and rat Ig appeared to bind to the sinusoidal wall. ICx bind in preference to aggregates. Monomeric Ig and aggregated Ig from swine and rabbit did not bind. The results demonstrated that ICx and rat and human Ig aggregates were bound via an Fc receptor. This Fc receptor was still intact in livers from carbontetra chloride and galactosamine treated rats. The receptor could also be demonstrated on spleen macrophages and on kidney interstitial cells. This method turned out to be an useful functional histochemical method to localize Fc receptors and to demonstrate their affinity and species specificity in tissues.

Animals↗

Studies on the mechanism of binding and uptake of immune complexes by various cell types of rat liver in vivo.

Soluble heterologous immune complexes (IC) were used to study the mechanism of IC binding to rat liver in vivo. Binding of IC to the various cell types of the liver, endothelial cells, hepatocytes, and Kupffer cells, was only inhibited by aggregated swine immunoglobulins. Binding was not inhibited by the absence of complement components. Intravenous injection of asialoglycoproteins, to block the galactose receptor, could not prevent IC binding. We conclude that Fc receptors play an important role in the binding of soluble heterologous IC to hepatocytes, endothelial cells, and Kupffer cells.

Animals↗

Hepatic uptake of autologous immune complexes in the rat.

The hepatic uptake of autologous immune complexes (ICx) was studied in Wistar rats immunized with bovine serum albumin (BSA). After attaining a suitable serum titre of rat anti-BSA Ig (RatABSA) they were injected intravenously with 2 mg BSA. The antibody levels were measured with an ELISA and the rate of disappearance of BSA from the circulation was studied by labelling the antigen with FITC. At various times after injection of BSA the uptake of ICx in the different types of liver cells was studied with the immunoperoxidase technique at the light microscope and ultrastructural levels. Within 5 min of injection with BSA ICx appeared to be bound and internalized by Kupffer cells, endothelial cells, and hepatocytes. After 2 h hepatocytes showed many large vacuoles containing ICx, whereas most microvilli had disappeared from the sinusoidal plasma membrane of these cells. In rats with a high antibody titre BSA had disappeared almost completely (92%) from the blood within 2 h. Rats with low antibody titre showed a lower disappearance rate of BSA, whereas a considerable amount of antibody was still present in the blood after 2 h. We conclude that autologous ICx are bound and endocytosed by Kupffer cells, endothelial cells and hepatocytes of the liver. The affinity for the antigen from the circulation. Uptake of autologous ICx by hepatocytes occurs only in the presence of large amounts of circulating ICx.

Animals↗

Zonal heterogeneity of rat hepatocytes in the in vivo uptake of 17 nm colloidal gold granules.

The in vivo uptake in hepatocytes of intravenously injected colloidal gold granules with a diameter of 17 nm or 79 nm and coated with bovine serum albumin or with polyvinyl-pyrrolidone was studied. Irrespective of coating only the 17 nm granules were taken up in hepatocytes. Perivenous hepatocytes did take up much more gold granules than periportal hepatocytes. The gold granules were found in lysosomes around bile canaliculi. Two hours after injection hepatocytes contained the maximal amount of granules. At least a portion of the granules was discharged into the bile. The observed zonal gradient in the uptake of 17 nm gold granules might be caused by the greater supply of granules to the perivenous hepatocytes as a combined result of the higher porosity of the endothelial lining and the smaller number of Kupffer cells with a low endocytic activity in this zone.

Animals↗

A histochemical study about the involvement of rat liver cells in the uptake of heterologous immune complexes from the circulation.

Intravenously injected immune complexes (ICx) composed of bovine serum albumin (BSA) and rabbit anti-BSA were taken up by the liver. Insoluble complexes, made in antibody excess, were rapidly taken up by Kupffer cells and were metabolized within 24 h. Soluble complexes, made in antigen excess, were only partly taken up by Kupffer cells. In addition these complexes were bound, taken up and metabolized by endothelial cells. Until 2 h after injection soluble complexes could also be observed along the microvilli of hepatocytes. No signs of endocytosis in hepatocytes could be observed. It is concluded, that ICx can be taken up by Kupffer cells as well as by endothelial cells. The physical state of the complexes, soluble or insoluble, determines the cell type in which uptake occurs.

Animals↗

[Importance of orientation on visual and neuronal resolution (author's transl)].

Spatial resolution of gratings of different orientation has been evaluated in 39 patients, by means of projected slides and by laser interference fringes. Both methods reveal a significantly higher resolution (about 12%) for vertical or horizontal bars compared to oblique ones. The similarity of findings for both methods is indicative of the neuronal origin of this orientation-dependent effect and exclude an optical origin.

Adolescent↗

A randomized trial comparing a pentavalent antimonial drug and recombinant interferon-gamma in the local treatment of cutaneous leishmaniasis.

In a randomized prospective trial N-methyl-glucamine antimoniate (Glucantime) and human recombinant interferon-gamma were infiltrated around lesions of cutaneous leishmaniasis caused by Leishmania tropica in Syria. A previous trial had shown that intradermal application of interferon-gamma promoted the healing of similar lesions in the study area. Twenty patients with 38 lesions received 1-3 ml Glucantime and 20 patients with 37 lesions received 25 micrograms of interferon-gamma intradermally once weekly for 5 consecutive weeks. While all lesions treated with Glucantime were free of parasites after the third injection, only 69% of those treated with interferon-gamma were parasitologically cured by week 10. Within 10 weeks, lesions treated with Glucantime healed completely in 29/38, and partially in 9/38, cases, whereas 1/37 and 13/37 lesions treated with interferon-gamma healed completely and partially, respectively. Perilesional application of Glucantime was highly effective and superior to interferon-gamma for treatment of cutaneous leishmaniasis caused by L. tropica.

Administration, Cutaneous↗

Pattern of sexually transmitted diseases in a Malagasy population.

BACKGROUND: Data concerning the spectrum and antimicrobial susceptibility of STDs in Madagascar are scarce. OBJECTIVES: Improvement of STD patient management in Madagascar. GOAL OF THE STUDY: Assessment of the spectrum of STDs and improvement of therapy. STUDY DESIGN: Etiologic study of 400 patients (169 men, 231 women) under consultation at the major STD service in Antananarivo for one or more of the STD syndromes, urethral discharge, cervicovaginal discharge, genital ulcers, or condylomata according to a fixed diagnostic schedule. RESULTS: Of genital ulcers, syphilis accounted for 46%, lymphogranuloma venereum for 24%, chancroid for 16%, and herpes for 1%. Of the syphilis cases, 51% presented as condyloma lata. Discharge was found in 124 men and 210 women. Counting concomitant infections separately, gonorrhea occurred in 69% of the men and 20% of the women with discharges, chlamydia infection in 42% and 52%, trichomoniasis in 9% and 31%, candidiasis in 12% and 30%. Bacterial vaginosis was found in 37% of the women with discharges. In 32% of male and 71% of female gonorrhea cases, there was concurrent chlamydia infection. Infection with HIV 1 or 2 was not detected. Determination of the antibiotic susceptibility of Neisseria gonorrhoea revealed high efficacy of ampicillin, ciprofloxacin, and spectinomycin; but frequent resistance to tetracycline and cotrimoxazole. CONCLUSIONS: High priority should be given to the management of infections with chlamydia and with Treponema pallidum as well as to educational measures to increase awareness of genital ulcer disease.

Adolescent↗

Imported schistosomiasis in Europe: sentinel surveillance data from TropNetEurop.

BACKGROUND: Schistosomiasis is a major parasitic disease, increasingly imported into temperate climates by immigrants from and travelers to endemic areas. METHOD: To generate valid data on imported infectious diseases to Europe and to recognize trends over time, the European Network on Imported Infectious Diseases Surveillance (TropNetEurop) was founded in 1999. Three hundred and thirty-three reports of schistosomiasis were analyzed for epidemiologic and clinical features. RESULTS: Male patients accounted for 64% of all cases. The average age of all patients was 29.5 years. The majority of patients were of European origin (53%). Europeans traveled predominantly for tourism (52%). Main reasons for travel for people from endemic areas were immigration and refuge (51%) and visits to relatives and friends (28%). The majority of infections were acquired in Africa; 92 infections were clearly attributable to Schistosoma haematobium, 130 to Schistosoma mansoni, and 4 to Schistosoma intercalatum. Praziquantel was the only treatment used. No deaths were recorded. CONCLUSION: TropNetEurop sentinel provides valuable epidemiologic and clinical data on imported schistosomiasis to Europe.

Adolescent↗