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Biomedical subjects

H Feldmeier

Publications and source records attributed to H Feldmeier.

At least 73 records · Page 4Linked to original sources
PubMed1993

A synoptic inventory of needs for research on women and tropical parasitic diseases. II. Gender-related biases in the diagnosis and morbidity assessment of schistosomiasis in women.

A synoptic inventory developed by us (Feldmeier and Krantz, 1993) was used for systematically reviewing existing data as to how and to what degree gender- and sex-related factors influence the validity of the diagnosis of schistosomiasis in women. Diagnostic sectors comprising survey methodology, parasitological methods, immunodiagnosis, detection of pathology and diagnosis of schistosomiasis in the female genital tract have thus been scrutinized. In this way we have identified important gaps in the scientific knowledge of diagnosis of an important parasitic infection. Socio-cultural and gender-related determinants have never been studied systematically, and it is mostly by circumstantial evidence that we can point out potential biases, sometimes for sex but more often for gender, in much of the published material concerning diagnostic categories suitable for schistosomiasis. These errors in diagnostic procedures and the ensuing lack of validity deserve attention from the fields of biomedicine and social science, preferably in a collaborative effort.

Adolescent↗
PubMed1993

Immunochemotherapy of visceral leishmaniasis: a pilot trial of sequential treatment with recombinant interferon-gamma and pentavalent antimony.

The clinical, parasitological, hematological, and serological evolution of visceral leishmaniasis in Brazilian patients was assessed during treatment with human recombinant interferon-gamma (rIFN-gamma; 0.1 mg/m2 i.m. days 1-14) followed by pentavalent antimony (Sbv; 10 mg/kg days 22-28). At day 30, 6 patients had improved, 2 had slightly improved, and 1 patient had deteriorated. IFN-gamma was well tolerated in the dose tested and may be very effective as an adjunct to conventional therapy with antimony.

Adolescent↗
PubMed1993

Trichinosis: a prospective controlled study of patients ten years after acute infection.

The existence of chronic trichinosis as a disease entity is still a matter of debate. For 10 years after an outbreak of infection with Trichinella spiralis, we conducted a prospective controlled study of the patients involved. At the termination of this investigation, we undertook clinical, biochemical, serological, immunologic, neuroradiological, radiological, and psychological studies of 128 originally infected persons and 16 controls. The categories of symptoms most often documented in persons who had been infected were muscular (90%), ocular (59%), neurological (52%), and psychological (52%). Impaired muscle strength (56%), conjunctivitis (55%), and impaired coordination (32%) were the clinical manifestations most frequently encountered. Thirty-eight percent of the 128 originally infected patients still had IgG antibodies to T. spiralis after 10 years. Magnetic resonance imaging of the brain revealed no abnormalities. No calcifications of residual larvae were detected by mammography or muscle biopsy. The level of performance in psychometric tests was lower in the originally infected population than in the general population. Although patients who had had trichinosis differed significantly from controls in terms of a variety of parameters even after 10 years, we found insufficient evidence on which to conclude that chronic trichinosis exists as a distinct entity.

Adult↗
PubMed1992

Urine test strips: reliability of semi-quantitative findings under tropical conditions.

Semi-quantitative urinalysis with urine reagent strips (URS) for erythrocyturia (EU), leucocyturia (LU) and proteinuria (PU) was performed in Congolese and Sudanese school children with Schistosoma haematobium and/or S. mansoni infection. Quantitative urinalysis was performed on the same specimen using microscopy and a Neubauer counting chamber for EU and LU and the Coomassie blue dye-binding assay for PU. Microscopically detectable EU of more than 10 cells/microliters was found in 63% of all samples and LU of more than 20 cells/microliters was found in 60% of all samples. With the Coomassie blue method, PU of more than 150 mg/l was detected in 51% of all samples. URS gave positive results of grade 1-3 for EU in 69% of all samples, for LU in 63% of all samples and for PU in 66% of all samples. The sensitivity and specificity of URS compared with standard reference methods were as follow: EU 95% and 75%, LU 81% and 81% and PU 90% and 56%. When the results of all three test were combined, URS differentiated abnormal from normal urine specimens with a sensitivity of 94% and a specificity of 70%. Median quantitative results showed a good correlation with semiquantitative URS readings for all parameters, but there was a wide range of URS scores. We concluded that URS sensitivity detect urinary abnormalities and thus may be used as a general screening method under field conditions when more specific methods cannot be performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Congo↗
PubMed1992

Sonographic organometry in Brazilian and Sudanese patients with hepatosplenic schistosomiasis mansoni and its relation to the risk of bleeding from oesophageal varices.

Fifty-nine patients with hepatosplenic schistosomiasis mansoni were investigated by sonography in Northeast Brazil and Central Sudan. The sizes of the organs usually involved in this disease were quantitatively assessed according to a standardized protocol, and measurements were adjusted to the body height of the individual. The results were compared with those of healthy controls matched by sex, age, geographical origin and socio-economic status. Considerable differences were found between patients and controls as well as between residents from the two areas. The liver of both patients and controls from the Sudan was significantly smaller than that of patients and controls from Brazil. Only in Brazil, but not in the Sudan, was the left liver lobe larger in patients than in the controls. The diameter of the portal and the splenic vein, the spleen size and the thickness of the gallbladder wall were significantly increased in patients from both areas. The increase of the portal and splenic vein diameter was significantly correlated with the degree of hepatic periportal fibrosis and the frequency of bleeding from endoscopically proven oesophageal varices in the patients, irrespective of their geographic origin. In contrast, such correlations were not found for the degree of splenomegaly nor for the degree of gallbladder-wall thickening. It is concluded that standardized sonographic organometry permits the assessment of morbidity in hepatosplenic schistosomiasis mansoni under different endemic conditions. Especially the measurement of the portal vein diameter may allow estimation of the risk of gastrointestinal haemorrhage in these patients.

Adolescent↗
PubMed1992

Hepatosplenic schistosomiasis: comparison of sonographic findings in Brazilian and Sudanese patients--correlation of sonographic findings with clinical symptoms.

Twenty-seven Brazilian and 32 Sudanese patients with hepatosplenic schistosomiasis from areas where the disease is endemic were examined with ultrasound (US). Hyperechoic periportal areas indicating periportal fibrosis (PPF) were present in all patients irrespective of their origin. Nonspecific findings were splenomegaly (all patients), gallbladder wall thickening (81% and 92%, respectively, in Brazilian and Sudanese patients), portal vein (74% and 87%, respectively) and splenic vein (59% and 70%, respectively) enlargement, and portosystemic vascular shunts (62% and 61%, respectively). The hepatic alterations were congruent and the frequency of their occurrence was similar in both patient groups. With a standardized grading system, it was shown that grade of PPF was significantly correlated with a history of bleeding from endoscopically proved esophageal varices and with distention of the portal vein as measured with US. It was concluded that sonographic grading may be used in patients with hepatosplenic Schistosoma mansoni infection who originate from completely different endemic areas.

Adolescent↗
PubMed1992

A comparative study of four serological methods for diagnosis of acute and chronic Chagas' disease in Brazilian patients.

Complement fixation (CF), indirect immunofluorescence (IFAT), latex agglutination (LA) and the enzyme-linked immunosorbent assay (ELISA) were applied to assess the diagnostic value of antibody determination in Brazilian patients with acute or chronic Chagas' disease. Patients with various forms of leishmaniasis and healthy individuals from the endemic region were used as specificity controls. Whereas LA, IFAT and ELISA identified 81% of acutely ill patients, CF had no diagnostic potential in this phase of the disease. In later stages CF showed a sensitivity of 69% as compared to 100% for LA, IFAT and ELISA, irrespective whether patients presented clinically as chronic asymptomatic or chronic symptomatic cases. Cross-reactivity with anti-leishmania antibodies was observed in 23%, 38% and 77% of serum samples in LA, ELISA and IFAT, respectively, but not in CF.

Acute Disease↗
PubMed1991

New clinical and experimental aspects of intestinal magnesium transport.

Mg transport across various segments of the rat small and large bowel was measured in the absence of electrochemical gradients and using the voltage clamp technique. In the mucosa-to-serosa (ms) Mg flux across the duodenum, ileum, and colon a cellular part is involved, amounting to 40-70% of the total ms Mg flux measured across the short-circuited tissue. However, serosa-to-mucosa (sm) Mg flux is purely passive, suggesting that net Mg transport is largely determined by convectively driven Mg flux across the paracellular pathway. Mg is absorbed across the colon and ileum but in the duodenum paracellularly it is secreted due to an 'anomalous solvent drag effect'. Mg in the caecum decreases cellular ms Ca transport but in the other segments only passive ms Ca flux is reduced by a decrease of the paracellular permeability for Ca, or by a Mg-induced decrease in water absorption. Mg transport across all segments is insensitive to 1,25(OH)2D3. Dexamethasone abolishes cellular Ca transport but stimulates paracellular ms Mg flux in the duodenum. It is concluded that in the rat (a) Mg and Ca are transported by distinct cellular and paracellular mechanisms; (b) Mg transport is largely confined to the paracellular pathway; (c) the ileum and the colon are the major sites for the gut regulation of Mg homeostasis.

Animals↗
PubMed1991

Sequelae after infection with Trichinella spiralis: a prospective cohort study.

It is still a matter of debate whether or not infection with Trichinella spiralis is followed by long lasting sequelae. A common source epidemic of trichinosis which occurred in Bitburg, FRG, in October 1982 gave us the opportunity of performing a controlled cohort study (171 patients and 51 controls). 145 patients and 44 controls completed the 3 year follow-up. Complaints persisted in 36% of patients aged less than 30 years and in 100% of patients aged greater than 50 years. Complaints in order of frequency were: muscular complaints 84%, ocular complaints 63%, cardiac complaints 48%, cephalgia 43%, neurological complaints 35%, gastrointestinal complaints 18%, m fatigue and weakness 18%, oedema 12% and fever less than 1%. IgG antibodies to T. spiralis were still present in all but 5 patients 3 years after infection. IgM antibodies were either low or absent. In our patients the frequency and pattern of complaints and the correlation to the specific antibody response provide evidence that trichinosis causes long-lasting disease. Yet, from our data we were unable to draw conclusions as to the causative pathophysiological mechanisms.

Adolescent↗
PubMed1990

Mixed Schistosoma haematobium and S. mansoni infection: effect of different treatments on the serum level of circulating anodic antigen (CAA).

In this study, levels of circulating anodic antigen (CAA) in serum were investigated after differential treatment of 160 Sudanese patients with mixed Schistosoma haematobium and S. mansoni infections. The patients were randomly divided into four groups, which were treated with metrifonate (two doses of 10 mg/kg bodyweight), oxamniquine (60 mg/kg), praziquantel (40 mg/kg), or a multivitamin preparation, respectively. Serum, stool and urine samples were taken prior to treatment as well as one month and five months after chemotherapy. Before chemotherapy CAA levels were similar in the four groups. Antigenemia remained unchanged in the control group. In patients treated with praziquantel or oxamniquine the concentration of CAA decreased to a similar extent. However, whereas in the praziquantel group absence of CAA was already observed one month after treatment, clearing of CAA from the circulation seemed to take longer in patients treated with oxamniquine. Treatment with metrifonate did not result in a reduction of the CAA titres.

Animals↗
PubMed1990

Re-infection in human schistosomiasis mansoni: a prospective field study 18 months after praziquantel therapy.

Twenty-eight Zairean patients with Schistosoma mansoni infection were investigated and treated with praziquantel. Of these, 22 were re-examined 18 months later and 13 were found to be re-infected. Eighteen uninfected Zaireans were monitored concurrently to control for variations unrelated to schistosomiasis. Pathophysiological changes related to liver fibrosis were assessed by the determination of serum cholylglycine and procollagen-III-peptide. Circulating T-cell subsets were quantitated, and shedded T-cell antigens were measured in sera. In patients initially presenting with hepatomegaly, the biochemical indicators for egg-induced immunopathology became normal after therapy and remained normal even after re-infection, when the parasite load attained about 50% of the pretreatment level. Among T-cell phenotypes, CD4+ cells transiently increased by three months after treatment, but after 18 months the CD4/CD8 ratios both in patients then re-infected and in those not re-infected had reverted to the respective balances which had been observed at the start of the investigation. Both soluble CD8 antigen and interleukin 2 receptor in patients' sera were significantly elevated throughout the study period. The results indicate a dissociation of factors regulating fibrogenesis and immunomodulation after treatment and re-infected.

Adolescent↗
PubMed1990

Immune response in patients during and after Plasmodium falciparum infection.

The kinetics of indicators of lymphocyte activation were determined in non- and semiimmune patients with uncomplicated Plasmodium falciparum infection and in control subjects in Acre, Brazil. Delayed type hypersensitivity (DTH) to seven recall antigens was weakest in nonimmune patients. Both patient groups differed significantly from controls on admission (P less than .001 for both) and improved considerably after clindamycin therapy. Total serum IgG and IgM, but not antimalarial antibodies, were highest in nonimmune patients compared with semiimmune patients and controls during acute malaria. Immunoglobulin levels normalized after chemotherapy. A striking decrease of CD4+ peripheral blood lymphocytes, normalizing after chemotherapy, was seen in both patient groups, and was more pronounced in nonimmune patients. A slight increase in interleukin-2 receptor (IL-2R)-bearing cells was found in nonimmune patients. In addition, soluble plasma IL-2R was significantly elevated in them (P less than .001) and to a lesser extent in semiimmune patients. These findings were paralleled by significantly decreased IL-2 concentrations in plasma (P less than .001) during the acute phase of malaria, suggesting pronounced general immunosuppression in nonimmune malaria patients.

Adolescent↗
PubMed1990

Tumour necrosis factor in hepatosplenic schistosomiasis.

Periportal fibroplasia is the dominating feature of hepatosplenic schistosomiasis. Since monokines play an important role in the regulation of fibroplasia, tumour necrosis factor (TNF) and interleukin 1 beta (IL-1 beta) were assessed in sera and cell culture supernatants from patients with intestinal and hepatosplenic schistosomiasis before and 3-6 months after treatment with praziquantel. Uninfected controls were from the study area in Alagoas, Brazil. TNF was measured using an L-M mouse fibroblast bioassay and radioimmunoassays specific for TNF-alpha. Whereas TNF-alpha was elevated threefold in the patients' sera, three- to five-fold reductions of TNF were observed by radioimmunoassay and bioassay, respectively, in cell culture supernatants of hepatosplenic schistosomiasis patients. Significant deviations, in opposite directions, from TNF levels in control sera and supernatants are most plausible in the event of a sequestration of TNF-alpha-producing cells from the circulation. This process may be disease stage-specific since a dichotomy between incipient and advanced cases of hepatosplenic schistosomiasis became apparent in the amplitude and kinetics of changes during the follow-up after treatment.

Adolescent↗
PubMed1989

Presence of circulating anodic antigen in serum of Schistosoma intercalatum-infected patients from Gabon.

The presence of the schistosome circulating anodic antigen (CAA) in serum of Schistosoma intercalatum-infected patients from Gabon has been investigated using an enzyme-linked immunosorbent assay (ELISA). Blood samples were collected from 10 endemic controls, 29 patients which excreted viable S. intercalatum eggs in rectal mucosa and stool, six persons in which only non-viable eggs were found in rectal biopsy specimens and one person in which besides non-viable eggs a small number of viable eggs was found in the rectal biopsy specimen. CAA, a genus-specific antigen, could be demonstrated in 58.6% of the patients with S. intercalatum eggs in their stools. In comparison to S. mansoni infections, very light infections (0.6 eggs per gram faeces) could be detected by the ELISA. A strong correlation between parasite burden (eggs per gram faeces) and antigen-level (CAA-titer) was found (Spearman's rho = 0.65). Only one positive ELISA-results was found in the group with solely non-viable eggs in rectal tissue. As no false positive results were detected for the negative controls, the present results suggest, in accordance with results earlier obtained for schistosomiasis mansoni, that only in active S. intercalatum infections is antigen demonstrable.

Animals↗
PubMed1989

Immunological alterations in uncomplicated Plasmodium falciparum malaria. Relationship between parasitaemia and indicators of macrophage activation.

Numerical alterations of circulating lymphocytes were investigated in 37 Brazilian patients with uncomplicated Plasmodium falciparum malaria and in a group of 15 healthy controls. The number of CD4+ T helper/inducer cells was significantly lower in patients than controls, whereas absolute numbers of CD8+ suppressor/cytotoxic T cells did not differ between the groups. TNF and neopterin levels were markedly increased in the plasma of patients and remained slightly elevated after chemotherapy with clindamycin. Neopterin, but not TNF levels, were significantly correlated with parasitaemia. TNF was inversely related to monocyte counts. Interferon gamma could not be detected in the plasma of control subjects and was observed in only one patient. We conclude that in uncomplicated falciparum malaria the distribution of phenotypes of circulating lymphocytes are altered slightly and that the high plasma levels of TNF and neopterin indicate excessive release of these molecules by activated macrophages and the activation of cellular immune mechanisms during the infection.

Adolescent↗