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Biomedical subjects

N de Jonge

Publications and source records attributed to N de Jonge.

At least 37 records · Page 2Linked to original sources
PubMed1995

High plasma antithrombin levels in acute hepatitis A.

BACKGROUND: Laboratory testing of antithrombin serves to demonstrate a decreased concentration that is indicative of a thrombotic tendency. We report unexpected high levels of antithrombin in a patient with hepatitis A. METHODS: A 37-year-old woman with a 4-week history of acute hepatitis A was studied. The diagnosis of cholestatic hepatitis A was confirmed by positive serology and liver biopsy. The patient recovered completely within 6 months. RESULTS: Antithrombin activity was increased (234%; reference range, 80-120%). This high activity was confirmed by an antithrombin antigen of 210%. On recovery antithrombin activity returned to normal. CONCLUSIONS: We are unaware of other reports of such high levels of antithrombin, in particular in patients with hepatitis A. It is not clear whether the high concentration observed in this case is due to an acute-phase reaction or to impaired clearance by the liver. The presence of a molecular variant with different secretion characteristics is unlikely, since antithrombin activity returned to normal on recovery, suggesting base-line values within the normal range.

Acute Disease↗
PubMed1994

Reduction of donor-specific cytotoxic T lymphocyte precursors in peripheral blood of allografted heart recipients.

Tolerance to allografted hearts in human recipients has been observed both in clinical situations and in in vitro experiments. To elucidate whether a quantitative change of alloreactive CTL is one of the mechanisms accounting for this graft tolerance, CTL precursor (CTLp) frequencies in the peripheral blood of 10 heart recipients were measured against spleen cells from donors and HLA nonidentical third-party persons. In this longitudinal follow-up study, we showed that the rejection reaction(s) in the grafted heart correlated with CTLp frequencies in samples taken before transplantation against the donor spleen cells, but not with the CTLp frequencies against the spleen cells from the third-party persons. The CTLp frequencies against the spleen cells from donors decreased 4-6 months after transplantation, and remained at a low level afterward. However, the CTLp frequencies against spleen cells from third-party persons in blood samples obtained 1 year after transplantation were not significantly different from those before transplantation. Therefore, we conclude that donor-reactive CTLs are important in rejecting allografted heart. The decrease in donor-specific CTLp after transplantation could explain the donor-specific tolerance. The decrease may be due to homing of the specific CTLp to the graft, or by clonal deletion of the donor-reactive CTL caused by chronic alloantigen stimulation in the presence of immunosuppressive therapies.

Blood Cells↗
PubMed1994

Monitoring the efficacy of different doses of praziquantel by quantification of circulating antigens in serum and urine of schistosomiasis patients.

We evaluated the quantitation of two schistosome circulating antigens in serum and urine as a tool for the assessment of the efficacy of praziquantel dosage regimens (40 versus 60 mg/kgbw). In addition we compared the efficacy of two different brands of praziquantel (Biltricide and Distocide), given at the same dosage (40 mg/kgbw). Thirty five Egyptian hospitalized schistosomiasis mansoni patients participated in this study. Thirteen patients (Group 1) received 60 mg/kgbw Biltricide, administered in 3 oral doses of 20 mg in one day; 22 individuals (Group 2) were treated with 40 mg/kgbw (12 Biltricide, 10 Distocide), given in one oral dose. Circulating anodic antigen (CAA) and circulating cathodic antigen (CCA) were quantitated by monoclonal antibody-based ELISA's before, and 1, 3 and 6 weeks after chemotherapy. Before treatment, all patients were positive for at least one of the circulating antigen assays. Three to six weeks after treatment significantly more patients were found to be negative in Group 1 compared to Group 2 (X2 = 7.13, P = 0.008, n = 35). Also the levels of CCA and CAA in serum and of CCA in urine were found to be significantly higher in Group 2 (Mann-Whitney U < 85, P < 0.05, n = 35). These results were confirmed by parasitological data. No differences were found between treatment with Biltricide or Distocide.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1993

Innervation of the endomyocardium in the first period after heart transplantation.

Serial endomyocardial biopsies from 5 patients during the first 3 months after heart transplantation were studied by immunohistochemistry for the neural markers neurofilament 200 kD, neuron-specific protein 9.5 (PGP9.5), S100 (Schwann cell marker), and tyrosine hydroxylase (TH). In normal endomyocardium, nerves immunoreactive for neurofilament 200 kD and PGP9.5 occurred in the interstitium around blood vessels, in close contact with myocyte fibrils. Immunoreactive fibers identified for S100 and TH were also present. In biopsies taken after transplantation, the basic nerve structure in neurofilament labeling was intact. There was a disappearance of immunolabeling for PGP9.5, S100, and TH during the first month after transplantation. Immunoreactivity reappeared during the second month, at first in the interstitium around blood vessels. This was observed for PGP9.5 and TH between 4 and 6 weeks after transplantation, and for S100 (in two of five patients) starting after 6 weeks. There was no apparent relation between reappearance and occurrence of rejection.

Biomarkers↗
PubMed1993

Slow conduction in the infarcted human heart. 'Zigzag' course of activation.

BACKGROUND: Ventricular tachycardias occurring in the chronic phase of myocardial infarction are caused by reentry. Areas of slow conduction, facilitating reentry, are often found in the infarcted zone. The purpose of this study was to elucidate the mechanism of slow conduction in the chronic infarcted human heart. METHODS AND RESULTS: Spread of activation was studied in infarcted papillary muscles from hearts of patients who underwent heart transplantation because of infarction. Recordings were carried out on 10 papillary muscles that were superfused in a tissue bath. High-resolution mapping was performed in areas revealing slow conduction. Activation delay between sites perpendicular to the fiber direction and 1.4 mm apart could be as long as 45 milliseconds. Analysis of activation times revealed that activation spread in tracts parallel to the fiber direction. Conduction velocity in the tracts was between 0.6 and 1 m/s. Although tracts were separated from each other over distances up to 8 mm, they often connected with each other at one or more sites, forming a complex network of connected tracts. In this network, wave fronts could travel perpendicular to the fiber direction. Separation of tracts was due to collagenous septa. At sites where tracts were interconnected, the collagenous barriers were interrupted. CONCLUSIONS: Slow conduction perpendicular to the fiber direction in infarcted myocardial tissue is caused by a "zigzag" course of activation at high speed. Activation proceeds along pathways lengthened by branching and merging bundles of surviving myocytes ensheathed by collagenous septa.

Electrocardiography↗
PubMed1992

Magnetic bead antigen capture enzyme-linked immunoassay in microtitre trays for rapid detection of schistosomal circulating anodic antigen.

We have developed a new magnetic bead antigen capture enzyme-linked immunoassay for the detection of schistosomal circulating anodic antigen. The assay utilizes IgG1 monoclonal antibody coated monodisperse magnetic beads in microtitre trays fitted to a special magnet. The total test time was found to be 1-2 h, using 0.05 mg beads per well. The lower detection level was 0.7 ng AWA-TCA per ml (approximately 0.07 ng CAA per ml). Validation by sera from uninfected and Schistosoma mansoni infected Africans and Norwegians resulted in an assay specificity of 100% and sensitivity was close to 90% for cases excreting more than 100 eggs per gram faeces. At such clinically relevant levels the inter-assay CV was below 10% and photometric absorbance correlated to antigen levels was nearly linear. There was a significant correlation between the magnetic bead EIA absorbance values and the titres obtained using the previously established ELISA. The new bead assay, however, was easier and less laborious because TCA pretreatment and the titration of positive results were unnecessary.

Africa↗
PubMed1992

Detection of circulating anodic antigen before and after specific chemotherapy in experimental murine Schistosomiasis mansoni.

In two groups of mice infected with 60 (group I) and 120 (group II) Schistosoma mansoni cercariae, respectively, the effects of intensity and duration of infection, and of praziquantel therapy (curative vs subcurative dose) on the levels of circulating anodic antigen (CAA), were studied. CAA was measured in trichloracetic acid-treated serum samples with an avidin-biotin enzyme-linked immunosorbent assay (AB-ELISA) using the monoclonal anti-CAA antibody. Total worm burdens, oogram patterns and ova counts/g liver and intestine were followed up. The lowest detectable level of CAA was about 1.0 ng/ml, and was positive with a worm load of 3-5/mouse. CAA levels became already detectable as early as 1-2 weeks post-infection (pi) before any parasitological parameter and showed a significant drop from the 11th-12th week pi onwards. A positive correlation was demonstrated between the CAA level and worm load. Following successful praziquantel therapy, CAA disappeared earlier than any of the other parameters studied.

Animals↗
PubMed1991

Assessment of cure in schistosomiasis patients after chemotherapy with praziquantel by quantitation of circulating anodic antigen (CAA) in urine.

The kinetics of circulating anodic antigen (CAA) levels in urine were studied in Egyptian male patients infected with Schistosoma mansoni or with both S. mansoni and S. haematobium, before treatment, and at one, three and six weeks after chemotherapy. A quantitative enzyme-linked immunosorbent assay (ELISA) demonstrated CAA in 82% of the serum and 89% of the urine samples from these 28 patients. To evaluate the possibility of circadian variability in urine CAA levels, samples were examined in 15 patients at four intervals during a 24-hour period. No significant differences in CAA titers were observed. Seventeen patients were subsequently treated with praziquantel and followed for six weeks. CAA titers in serum and urine decreased significantly one week after therapy. Thereafter, the profile of CAA titer in urine continued to show a parallel but delayed decline compared to that in serum. While all serum CAA titers became negative three to six weeks after treatment, urine titers were negative in 47% at three weeks and 69% at six weeks. The remaining positive patients had low titers. A significant quantitative correlation in CAA titer was found between serum and urine before and after treatment. Seventeen Egyptian control subjects with no active schistosome infection were negative for CAA in both serum and urine. Our results confirm that the CAA urine assay could be used as a sensitive and non-invasive method to diagnose the disease, and indicate that the assay can be used to monitor efficacy of schistosome chemotherapy.

Adolescent↗
PubMed1991

Urinary schistosomiasis in the Sichili Health Zone, Western Province, Zambia.

The distribution of Schistosoma haematobium in the Sichili Health Zone in the Western Province of Zambia was studied by performing cross-sectional surveys in Mwanalulenga (n = 493), a cluster of rural settlements along the Namakala stream and the Machili river, Mulobezi (n = 114), a semi-urban settlement along the Mulobezi river; and school-based surveys in Mulauli (n = 85), a small rural settlement along the Machili river, and in Sichili (n = 199), along the Namakala stream. The S. haematobium infection was assessed by the urine filtration technique. Prevalences ranged from 20.6 to 87.1%, 23.8% of all people were heavily infected (greater than or equal to 50 eggs per 10 ml of urine).

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

Immunodiagnosis of schistosomiasis patients in The Netherlands: comparison of antibody and antigen detection before and after chemotherapy.

We investigated in a retrospective study the application of an enzyme-linked immunosorbent assay (ELISA) for the quantitative detection of the schistosome circulating anodic antigen (CAA) to the diagnosis of schistosomiasis in our laboratory. CAA-titres were compared with IgG-titres as determined with an ELISA using soluble egg antigen (SEA) and IgM-titres as determined in an immuno fluorescence assay (IFA) on sections of Rossman's fixed schistosomes. Pre- and post-treatment serum samples of 182 individuals, suspected for schistosomiasis, were used for this study, including 100 control samples. CAA was detected in 20.7% of all patients who were positive in either IFA or SEA-ELISA or both. CAA-titres did not correlate with either IgM-titres or IgG-titres. No significant drop in IgG level was found after specific treatment (Wilcoxon's P = 0.35). In contrast, a significant fall in both IgM-titre (P less than 0.01), and CAA-level (P less than 0.01) was observed. All CAA-titres became negative after chemotherapy.

Animals↗
PubMed1990

Valsalva termination of ventricular tachycardia in myocardial infarction.

A 66-yr-old patient with recurrent monomorphic ventricular tachycardias subsequent to a previous myocardial infarction is reported. The tachycardia could repeatedly be terminated by the Valsalva manoeuvre. Procainamide, infused shortly before, possibly had an additional effect. As far as we know, this is the first report of ventricular tachycardias, as a result of an old myocardial infarction, that could be terminated by the Valsalva manoeuvre.

Aged↗
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

New approaches to the measurement of morbidity in intestinal schistosomiasis.

New approaches for the assessment of morbidity due to schistosomiasis infection include the substitution of egg counts by quantitative assays for circulating schistosomal antigens, simple parameters for global immune responsiveness and functional hepatic alterations, and ultrasonography as an imaging technique. Quantification of circulating schistosome antigens in sera of S. mansoni, S. haematobium or S. intercalatum infected patients by sensitive immunoassays provides an exact measure for the individual worm burden. The effect of chemotherapy on immunomodulation was assessed by a panel of cutaneous recall antigens. Non-specific cell-mediated immune responses returned to subnormal pretreatment levels in the event of reinfection. Immunological morbidity can be monitored in this way. Pathophysiological alterations of the liver in S. mansoni infection can be assessed by the determination of unconjugated bile acids in the systematic circulation. The regression of intrahepatic vascular lesions in schistosomiasis with hepato(spleno)megaly can be detected earlier by this parameter than by ultrasonography. Ultrasonography provides characteristic, if not pathognomonic, images of Symmers fibrosis, and may be of value in the long-term evaluation of hepatic fibrosis.

Animals↗