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Biomedical subjects

H Feldmeier

Publications and source records attributed to H Feldmeier.

At least 109 records · Page 6Linked to original sources
PubMed1987

Kinetics of humoral response during the acute and the convalescent phase of human trichinosis.

After a common source outbreak of trichinosis in Bitburg, FRG, 107 patients, for whom time and source of infection were precisely known, were prospectively studied for a period of eight months in order to investigate the kinetics of the humoral immune response. Antibodies were assessed by IHA, and by ELISA to quantify IgG, IgM and IgE isotypes. For four different periods of the observation time sensitivity and predictive value of tests to identify acute or convalescent trichinosis were determined. The results demonstrated characteristic kinetics of the different antibody isotypes and varying diagnostic value of the tests. Only IgG-ELISA and double-sandwich IgM-ELISA reliably identified diseased patients shortly after onset of clinical illness and showed a negative predictive value of almost 100% from seven weeks to eight months after infection. IgE antibodies and elevation of total serum IgE occurred only in about 20% of patients and showed no consistent pattern during the course of the disease. Circulating immune complexes were moderately increased four weeks after infection. They rapidly returned to normal values, after the symptoms of the acute phase had disappeared.

Acute Disease↗
PubMed1987

Clinical experience with metrifonate. Review with emphasis on its use in endemic areas.

Metrifonate is an excellent drug for the treatment of urinary schistosomiasis in areas with S. haematobium monoinfection. Toxicity apparently is negligible. Side effects due to the inhibition of acetylcholinesterase are usually scarce, light and transient in nature. At the recommended dosage of 3 times 10 mg/kg the chemotherapeutic potential of metrifonate to cure can be expected to range between 60 and 90%. Each dose of metrifonate reduces egg excretion by almost 90%. Treatment with metrifonate clearly reverses lower and upper renal tract pathology. An intermittent course of metrifonate may be administered by minimally trained health personnel. When appropriately timed with regards to local transmission dynamics the minimal requirement to achieve 99% reduction of egg excretion may be as low as three or four doses spaced over a period of two years.

Animals↗
PubMed1987

Active immunization against hepatitis B: immunogenicity of a recombinant DNA vaccine in females, heterosexual and homosexual males.

Three groups of subjects (58 females, 54 heterosexual males, and 50 homosexual males) received three doses of a recombinant DNA yeast-derived hepatitis B vaccine according to a 0, 1, and 6 month vaccination schedule. Local and general side effects were mild. Seroconversion rates after three injections were not significantly different between the groups. Females showed a significantly higher anti-HBs response than both groups of males, and heterosexual males had higher antibody titres than homosexual males. Among the four homosexual non-responders, three were carriers of the human immunodeficiency virus.

Adolescent↗
PubMed1986

Human schistosomiasis: deficiency of large granular lymphocytes and indomethacin-sensitive suppression of natural killing.

Twenty-eight children infected with Schistosoma haematobium and S. mansoni were tested for natural killer (NK) cell activity in vitro using the myeloid/erythroid cell line K562 as target. In addition, the frequency of large granular lymphocytes (LGL) and the number of HNK-1+ lymphocytes were examined in peripheral blood. NK cell activity was found to be markedly reduced in most patients when compared with a group of healthy Caucasian individuals (P less than 0.005). Moreover, the impairment of NK activity clearly correlated with the intensity of infection, which was quantified by parasite ova excretion in stool and urine. Within the lymphocyte compartment the percentages of cells with the NK phenotype (HNK-1+) were found to be normal, although the majority of patients exhibited decreased numbers of LGL (P less than 0.005). The absolute and relative frequencies of LGL and HNK-1+ lymphocytes by no means correlated with the parasite load. In vitro results suggest an at least partly prostaglandin-mediated and interferon-resistant functional defect of NK cells.

Child↗
PubMed1986

The effect of metrifonate in mixed Schistosoma haematobium and Schistosoma mansoni infections in humans.

In order to examine the effect of metrifonate, 156 patients with mixed Schistosoma haematobium and mansoni infection were randomly divided into three groups and treated with metrifonate (twice 10 mg/kg body weight), oxamniquine (60 mg/kg) and praziquantel (40 mg/kg), respectively. The output of S. haematobium and S. mansoni ova were quantitatively assessed in urine and stool. Application of metrifonate resulted in a similar reduction of S. haematobium and S. mansoni eggs in the urine, whereas no effect on egg excretion was observed in the stool irrespective of the parasite species. In contrast, oxamniquine influenced the output of S. mansoni ova in stool and urine, but showed no effect on S. haematobium egg excretion. praziquantel was equally effective against both parasite species. The chemotherapeutic effects were not of transient nature since the number of ova of both parasite species remained unchanged five months after treatment. The results clearly indicate that metrifonate acted exclusively on adult worms located in the perivesical plexus irrespective of the parasite species.

Adolescent↗
PubMed1986

Detection of Dirofilaria immitis microfilariae in peripheral blood. A quantitative comparison of the efficiency and sensitivity of four techniques.

Four techniques for the detection and quantification of Dirofilaria immitis microfilariae in peripheral blood were compared, namely the conventional thick smear, thick films prepared by cytocentrifugation, filtration of blood through polycarbonate membranes, and density gradient centrifugation followed by membrane filtration. The efficiency of the methods and their sensitivity was assessed by determining quantitatively the recovery of known numbers of microfilariae from defined volumes of blood. Polycarbonate membrane filtration either alone or in combination with density gradient centrifugation showed an efficiency of 0.9 and 0.8, respectively, and reached 100% sensitivity with microfilariae densities of greater than or equal to 10 microfilariae per ml of blood. Conventional thick smears and cytocentrifugation were of considerably lower efficiency (0.02 and 0.03, respectively) and reached 100% sensitivity with more than 200 microfilariae per ml.

Animals↗
PubMed1986

Detection and quantification of circulating antigen in schistosomiasis by monoclonal antibody. II. The quantification of circulating antigens in human schistosomiasis mansoni and haematobium: relationship to intensity of infection and disease status.

Circulating cathodic and circulating anodic antigens were quantified in sera of patients infected with S. mansoni, S. haematobium or both parasites. A monoclonal antibody and a polyclonal antiserum were applied in precipitation and solid phase immunosorbent techniques using radio- and enzyme-labelled antibody as a tracer to detect the cathodic and anodic antigen respectively. The results show that circulating cathodic antigen can frequently be detected in an immunoprecipitation or an immunoradiometric assay in serum of infected patients. The serum concentration of this antigen was found to be significantly correlated to the number of S. mansoni worms and to be higher in patients with the hepatosplenic form of the disease than in those without such complications. Examining paired serum samples before and after specific treatment the determination of this antigen by monoclonal antibody reliably indicated efficacy of chemotherapy in patients having received different forms of treatment.

Adolescent↗
PubMed1985

Proteinuria, hematuria, and leukocyturia in children with mixed urinary and intestinal schistosomiasis.

Quantitative parasitological assessment and quantitative analysis of proteinuria, hematuria, and leukocyturia were carried out in 182 Sudanese schoolboys with mixed urinary and intestinal schistosomiasis. Pathological proteinuria was found in 73% of patients (median = 380, 95% confidence limits = 200 to 500 mg/liter). The median protein/creatinine ratio was 0.54. SDS polyacrylamide gel electrophoresis showed an excretion of albumin, transferrin, and IgG consistent with a postrenal pattern of proteinuria. Pathological erythrocyturia occurred in 84% of patients (median = 255, 95% CL = 95 to 629 cells/microliter) and leukocyturia in 77% of patients (median = 148, 95% CL = 93 to 246 cells/microliter). Phase contrast microscopy revealed intact erythrocytes, suggestive of postrenal hemorrhage. Proteinuria, erythrocyturia, and leukocyturia correlated significantly with the ova excretion in the urine, but not with egg excretion in the stool. Oxamniquine reduced ova excretion in the stool but did not influence pathological urine findings. In patients treated effectively with Praziquantel or Metrifonate, pathological PU, EU, and LU decreased markedly 1 month post treatment. PU in severely proteinuric patients reached physiological values 5 months post therapy. We suggest that the proteinuria, erythrocyturia, and leukocyturia in mixed schistosomiasis were of postrenal origin.

Adolescent↗
PubMed1985

Circadian variation of ova excretion, proteinuria, hematuria, and leukocyturia in urinary schistosomiasis.

Urine samples from five boys (7 to 9 years) with urinary schistosomiasis were collected at 6 A.M. and thereafter at 3-hr intervals until 9 P.M. on 5 consecutive days. Ova excretion in the urine, proteinuria (PU), erythrocyturia (EU), and leucocyturia (LU) were assessed quantitatively. Egg excretion followed a circadian rhythm with a peak at 12 noon and was paralleled closely by pathological PU. Maximal erythrocyturia occurred at 6 P.M., whereas leucocyturia revealed two distinct peak times. Taking the congruent patterns of egg excretion and PU together with the results of qualitative urinary protein analysis into account, it was concluded that PU was linked causally to ova excretion and could be explained by bleeding and exudation of serum proteins during penetration of ova through the bladder mucosa. In contrast, EU and LU seemed to be caused by different pathological mechanisms. EU followed a time-delayed circadian rhythm, possibly induced by persistent bleeding, whereas LU may have indicated a concomitant inflammatory component of the bladder.

Child↗
PubMed1985

Relationship between intensity of infection and immunomodulation in human schistosomiasis. I. Lymphocyte subpopulations and specific antibody responses.

Cellular and humoral immune responsiveness in 44 Sudanese children with schistosomiasis was studied and related to the intensity of infection. The parasite load was quantitated by accurate assessment of the excretion of ova of S. mansoni and S. haematobium in stool and urine, respectively. Lymphocyte subpopulations (T3+, T4+, T8+, TAC+, HNK1+, Ia+, SIg+, LGL+, ANAE+) as well as specific IgE and IgG antibodies to adult schistosome antigens were determined. The relationships existing between intensity of infection and cellular and humoral immune responsiveness revealed a distinct pattern of anti-parasite immunity: The percentage of pan-T cells (T3+) and the T helper (T4+):T suppressor (T8+) ratio were inversely correlated to the intensity of infection. In contrast, the percentage of T suppressor cells positively correlated to the parasite load. Ia+, TAC+, HNK1+ and T4+ cell counts did not show a significant relationship to worm burden. Specific IgE and IgG antibodies to S. mansoni and S. haematobium adult worm antigen clearly increased with the parasite load. The dichotomy of decreased T cell parameters and increased antibody response in heavily infected individuals represents a unique feature in helminthic infections.

Antibody Formation↗
PubMed1985

Relationship between intensity of infection and immunomodulation in human schistosomiasis. II. NK cell activity and in vitro lymphocyte proliferation.

Natural killer (NK) cell activity against K-562 targets and lymphoproliferative responses to Con A, interleukin-2 (IL-2) and Con A + IL-2 were examined in a group of 41 Sudanese children suffering from schistosomiasis mansoni and haematobium. The results were correlated to the intensity of infection as determined by enumeration of parasite ova in urine and stool. NK cell activity measured at three effector to target cell ratios was significantly depressed in the patient group as compared to a German control group. Impairment of NK cell activity showed a direct relationship with the patients' parasite load. Furthermore lymphoproliferation to Con A, IL-2 and Con A + IL-2 was depressed in the group of patients. Interestingly the costimulation effect of IL-2 expressed as coefficient of delta ct/min(Con A + IL-2)/delta ct/minCon A correlated significantly to the intensity of infection suggesting that lymphocytes from heavily infected patients were defective in producing appropriate amounts of IL-2 in response to Con A. Our findings support the concept that heavy infections with S. mansoni and/or S. haematobium induce a peculiar dichotomy of cellular and humoral immune parameters. Whereas T cell-dependent cellular immune responsiveness and NK cell function decrease with increasing worm burden specific IgE and IgG antibody responses increase.

Cells, Cultured↗
PubMed1984

[Epidemiology of Trichinella spiralis infections in the Eifel region, 1982].

In November 1982 146 persons became ill within a few days with trichinosis in Bitburg (GFR). Prompt epidemiological and immunodiagnostic investigations demonstrated the high likelihood of infection by ingestion of raw sausage produced at a butcher's near Bitburg. The diagnosis of trichinosis could be ascertained still in the acute phase of disease by demonstration of the Trichinella larvae in peripheral blood. Retrospective analysis of earlier disease from the same area showed that the same infection source had led to a smaller epidemic already in August/September of 1982. This investigation confirms that epidemic trichinosis may occur in the GFR despite law-enforced assessment of meat for Trichinella. However, by combination of epidemiological and immunodiagnostic methods the mode and source of infection can be established promptly and reliably.

Disease Outbreaks↗
PubMed1984

Serum antibody levels in human paragonimiasis before and after therapy with praziquantel.

Enzyme immunoassays (ELISA) and indirect haemagglutination (IHA) were used to determine IgG and IgE serum antibody levels in 43 patients from Ecuador before and after therapy with praziquantel. ELISA indicated infection more sensitively than IHA. The tendency of increasing antibody levels between the first and second month after therapy was more distinct when measured by IHA, whereas the decreases of antibody levels between the third and sixth month after treatment was more distinct when measured by ELISA. The IgG ELISA for detecting long persisting antibody was more sensitive than IHA.

Antibodies↗
PubMed1984

Intermittent chemotherapy with trichlorfon (metrifonate) reverses proteinuria, hematuria, and leukocyturia in urinary schistosomiasis: results of a three-year field study.

Trichlorfon (metrifonate) was given intermittently to 37 schoolboys with urinary schistosomiasis living in a hyperendemic area of the Sudan. Patients were followed up for three years. Initially, 10 mg of trichlorfon/kg of body weight was administered; this dosage was repeated 14 days and 16 months later. Patients still excreting eggs after 24 months received a fourth dose. At month 24, 61% and at month 36, 56% of the patients had no detectable egg excretion; the others showed severe reduction of egg output. The number of ova excreted was always paralleled by a combined scale of hematuria, leukocyturia , and proteinuria, as assessed by urine analysis reagent strips. Quantitative urine analysis at month 36 revealed pathological findings in only eight individuals. Thus, trichlorfon given three or four times in a dose of 10 mg/kg of body weight spaced over a period of two years was highly effective in reducing parasite load and disease in children living under hyperendemic conditions.

Child↗
PubMed1984

Numerical and functional alterations of lymphocytes in human schistosomiasis.

Peripheral blood mononuclear cells from 29 Sudanese children heavily infected with Schistosoma haematobium and S. mansoni were examined for lymphocyte subpopulations, for mitogen responsiveness in the absence and presence of interleukin-2 (IL-2), and for natural killer (NK) cell activity. The nutritional status was assessed by anthropometric and biochemical measurements. In comparison with a group of healthy Caucasian individuals the children with schistosomiasis showed a profound alteration of their cellular immune variables, reflecting a severe acquired immunodeficiency syndrome. The T-cell compartment, in particular the OKT4+ helper/inducer subset, was numerically reduced at the expense of an increased B-cell compartment. The patients' OKT4/OKT8 ratios were significantly diminished (median, 1.2; 95% confidence limits, 0.8-1.7) corresponding to a decreased responsiveness to the T-cell mitogen concanavalin A. Since addition of exogeneous IL-2 significantly enhanced the patients' lymphocyte proliferation in response to Con A, a defective IL-2 production was assumed to be at the origin of the impaired mitogenic response in chronic schistosomiasis. With regard to NK cell activity, most patients' lymphocytes failed to mediate significant cytotoxicity against the K562 target cell line, although normal percentages of cells with the NK phenotype (HNK-1+) were present. The results are discussed in view of immunological alterations seen in other parasitic infections with a heavy parasitic load.

Child↗