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Biomedical subjects

J van der Veen

Publications and source records attributed to J van der Veen.

At least 19 recordsLinked to original sources
PubMed1994

Controlled release of paracetamol from amylodextrin tablets: in vitro and in vivo results.

Amylodextrin is a suitable excipient for the design of solid controlled-release systems. The release of paracetamol from tablets containing 30% drug and 70% amylodextrin was studied in vitro and in vivo. In vitro dissolution profiles showed almost-constant drug release rates during 8 hr, when measured in 0.05 M buffer, pH 6.8. Peroral administration of the tablets to man showed almost-constant paracetamol plasma levels up to 14 hr, as compared to fast absorption and fast elimination of a reference paracetamol solution. The plasma profiles of eight volunteers demonstrated a small intersubject variability during the first day after tablet administration. Increasing variability and decreasing plasma levels during the second day were caused by excretion of tablets from the bodies. Cumulative input as a function of time showed near-zero-order drug release during the first day. The in vivo results indicate that amylodextrin tablets are not hydrolyzed by alpha-amylase, present in the gastrointestinal tract.

Acetaminophen↗
PubMed1988

Adult onset Still's disease and viral infections.

Several micro-organisms, especially viruses, have been associated with juvenile and adult onset Still's disease. In the present study a search for probable triggering viral infections in five consecutive patients with early, active adult onset Still's disease has been made. In one patient echovirus 7 was identified as a probable triggering agent. Evidence of infection with this virus was acquired by virus cultures and serological tests. In two patients the illness was probably initiated by a rubella reinfection. Both had initially high stable monospecific IgG antibody titres but no IgM antibodies to this virus. In the remaining two cases no particular triggering viral infection could be designated. Evidence of a viral infection was thus found in three of these five patients. Adult onset Still's disease may represent a reaction pattern to certain infections.

Adult↗
PubMed1985

Use of enzyme-labeled antigen for the detection of immunoglobulin M and A antibody to herpes simplex virus in serum and cerebrospinal fluid.

A direct enzyme-linked immunosorbent assay (ELISA that used peroxidase-labeled antigen) was developed for detection of IgM and IgA antibody to herpes simplex virus (HSV). The assay uses immuno-affinity-purified antihuman IgM or IgA antibody-coated wells of microtiter plates to separate IgM or IgA from other classes of antibody in serum or cerebrospinal fluid (CSF). The presence of specific IgM or IgA is detected by subsequent, consecutive incubation with peroxidase-labeled antigen and substrate. HSV antigen was purified by sucrose gradient centrifugation and coupled with peroxidase by the periodate method. By examining sucrose-gradient-fractionated sera the assays were shown to be specific for IgM and IgA classes of antibody. None of the sera from patients with Epstein-Barr virus (n = 20), cytomegalovirus (n = 20), or varicella-zoster virus (n = 8) infection or with both rheumatoid factor and IgG antibody to HSV (n = 13) reacted positively. Only one out of 78 sera from healthy persons was positive for IgA antibody to HSV, and none for IgM antibody. All 33 patients with HSV infection developed HSV-IgA, 22 developed HSV-IgM. Of the 11 patients with primary infection, all had IgM antibody in their first sera and six had IgA antibody. The corresponding figures for the 22 patients with recurrent infection were five and nine. Furthermore, HSV-IgA antibody was found in serum and CSF of all five patients with HSV encephalitis in the second week after onset of symptoms, indicating the usefulness of the assay as a noninvasive technique for diagnosing HSV encephalitis.

Antibodies, Viral↗
PubMed1985

Diagnosis of parainfluenza virus infection in children and older patients by detection of specific IgM antibody.

The significance of detecting specific antibody of the IgM class for the diagnosis of parainfluenza infections was examined. Paired sera from 763 children and adults admitted to the hospital for acute respiratory disease were tested for significant antibody titer rises in the hemagglutination inhibition (HI) test and for specific IgM antibody with the hemadsorption immunosorbent techniques (HIT). Sera were collected during two 6-month periods, January through June, 1982 and 1983. Evidence of parainfluenza infections was found in 122 patients (16%): 83 (25%) in 1982 and 39 (9.1%) in 1983. The HIT was superior to the HI test for detection of parainfluenza infection, in particular in infants and aged patients, 94 patients were positive only in the HIT test, 12 in the HI test, and 16 in both tests. In a control group of 120 persons (time- and age-matched to the patients of 1982) admitted for nonrespiratory illness, six (5%) showed parainfluenza IgM in their serum. Blocking experiments and retrospective clinical information indicated that the IgM antibody detected in these individuals is specific IgM acquired after a mild parainfluenza infection. Most (66%) patients showed IgM antibody titer rises or high titers (greater than 1,280) in both sera, and in 23%, a fall in IgM antibody titer was found. Detection of specific IgM antibody by HIT permitted early presumptive diagnosis in 71% of the patients with parainfluenza infection. IgM antibody persisted for 2-11 weeks. The HIT appears to be an important supplement for the diagnosis of parainfluenza infections.

Adolescent↗
PubMed1985

Quantitation of immunoglobulin E antibody to cytomegalovirus by antibody capture enzyme-linked immunosorbent assay.

An antibody capture enzyme-linked immunosorbent assay was developed for detection of immunoglobulin E antibody to cytomegalovirus (CMV-IgE). Affinity-purified anti-human IgE-coated microtiter plates were used to separate IgE from other classes of antibody in serum. Virus-specific IgE was detected by subsequent incubation with horseradish peroxidase-labeled CMV antigen and substrate. The assay was shown to be very sensitive, since in most positive sera CMV-IgE was still detected at a dilution of 1:5,000. Of 45 patients with primary CMV infection, 43 (96%) were found to produce CMV-IgE. In contrast, CMV-IgE was detected in only 4 (9%) of 44 patients with recurrent CMV infection and in 1 of 144 healthy controls. Furthermore, the level of CMV-IgE in patients with recurrent CMV infection appeared to be lower than that in patients with primary infection. Preliminary examination of successive sera suggested that CMV-IgE is produced somewhat slower than CMV-IgM and -IgA but persists for a shorter period. These results suggest that CMV-IgE may be used as an indicator of primary CMV infection.

Antibodies, Viral↗
PubMed1983

Enzyme-linked immunosorbent assay that uses labeled antigen for detection of immunoglobulin M and A antibodies in toxoplasmosis: comparison with indirect immunofluorescence and double-sandwich enzyme-linked immunosorbent assay.

A direct enzyme-linked immunosorbent assay (ELISA) is described that uses horseradish peroxidase-labeled antigen for detection of immunoglobulin M (IgM) and IgA antibodies to toxoplasma. In this assay, polystyrene microtiter plates were sensitized with anti-human IgM or IgA antibody to separate IgM or IgA from other classes of antibody. The presence of IgM or IgA antibodies to toxoplasma (Tox-IgM, Tox-IgA) was then detected by sequential addition of soluble horseradish peroxidase-labeled toxoplasma antigen and substrate. As judged by examining sucrose gradient-fractionated sera, the assay was specific for IgM or IgA classes of antibody. In contrast to the indirect immunofluorescence for IgM antibodies to toxoplasma, no inhibition of IgM reactivity by specific IgG antibodies could be detected. Furthermore, rheumatoid factor did not cause false-positive results. Of 80 single sera with high antibody titer to toxoplasma in indirect immunofluorescence and complement fixation, 40 were positive in the direct ELISA for Tox-IgM, 36 were positive in the double-sandwich ELISA, and only 21 were positive in the indirect immunofluorescence for Tox-IgM when whole serum was used. In the indirect immunofluorescence, another 13 sera became positive after sucrose gradient fractionation. The direct ELISA for IgA antibodies to toxoplasma was positive in 43 sera, of which 39 were positive in the direct ELISA for Tox-IgM. High levels of IgM antibodies were found within 3 months after the onset of symptoms, slowly decreasing thereafter. Tox-IgM may persist for more than 1 year after infection.

Antibody Specificity↗
PubMed1982

Detection of parainfluenza IgM antibody by hemadsorption immunosorbent technique.

A hemadsorption immunosorbent technique (HIT) was developed for the detection of immunoglobulin M (IgM) to parainfluenza virus types 1, 2, and 3. Twenty-six (90%) of twenty-nine patients under 6 yr of age from whom parainfluenza virus was isolated showed parainfluenza IgM antibody in one or both of their paired sera, with titres ranging from 320 to 81,920. In about one third of the cases IgM antibody was demonstrated in the initial sera taken 1 to 3 days after the onset of illness. Heterotypic IgM antibody responses were observed in about 20% of the patients. The HIT test was more sensitive than the hemagglutination inhibition (HI) and complement fixation tests in detecting a seroresponse in the 29 virus-positive children. The results of studies in older patients with HI titre rises to parainfluenza virus suggested that reinfection probably induced IgM antibody in a proportion of cases. The HIT test proved to be specific for the IgM class of antibody and avoided false-positive results due to rheumatoid factor. It permits an early presumptive diagnosis in a proportion of patients with parainfluenza infection.

Adolescent↗
PubMed1982

Hemadsorption immunosorbent technique for determination of mumps immunoglobulin M antibody.

We used hemadsorption immunosorbent technique (HIT) to detect mumps immunoglobulin M (IgM) antibody. IgM from human sera was adsorbed into anti-human IgM-coated wells in plates, and mumps-specific IgM was detected by adding mumps virus hemagglutinin and guinea pig erythrocytes consecutively. Specific IgM-positive sera showed hemadsorption, whereas negative sera showed hemagglutination. All 81 patients with current mumps infections tested showed mumps-specific IgM antibody, with titers ranging from 160 to 327,680. In most cases IgM antibody was already present on day 1 or 2 after the onset of illness. IgM antibody persisted for 6 to 10 weeks. Of 57 patients with acute respiratory illnesses caused by parainfluenza virus, 5 showed cross-reactions in the hemadsorption immunosorbent technique assay for mumps IgM. The hemadsorption immunosorbent technique assay is specific for the IgM class of antibody and avoids false-positive results due to rheumatoid factor. This test is an efficient and sensitive method for rapid and early diagnosis of mumps infections.

Animals↗
PubMed1981

Hemadsorption immunosorbent technique for determination of rubella immunoglobulin M antibody.

A highly specific and sensitive hemadsorption immunosorbent technique for measuring rubella immunoglobulin M (IgM) antibody is described. IgM from human sera was absorbed into anti-human IgM-coated wells in plates and rubella-specific IgM was detected by adding rubella virus hemagglutinin and a small quantity of sheep erythrocytes. Centrifugation of the plates facilitated reading of the test. Specific IgM-positive sera showed hemadsorption, whereas negative sera showed hemagglutination. Rheumatoid factor and rubella-specific IgG antibody did not interfere with the results. The test was clearly more sensitive than the solid-phase immunosorbent technique for detection of rubella IgM antibody by hemagglutination inhibition and at least as sensitive as the hemagglutination inhibition test on IgM fractions from a sucrose density gradient and the indirect immunofluorescence test for IgM antibody with absorbed serum. All of 40 sera from 17 rubella patients taken 4 to 49 days after the onset of rash were positive in the new test, with antibody titers ranging from 2,560 to 81,920 between 4 and 28 days. The test is reliable, practical, and suitable for general diagnostic use.

Antibodies, Viral↗
PubMed1981

Direct enzyme-linked immunosorbent assay that uses peroxidase-labeled antigen for determination of immunoglobulin M antibody to cytomegalovirus.

A direct enzyme-linked immunosorbent assay was developed for the measurement of immunoglobulin M (IgM) antibody to cytomegalovirus (CMV). Wells of microtiter plates were coated with anti-human IgM. Each patient's serum was added at a dilution of 1:100, and IgM from the serum was allowed to react with anti-human IgM. The amount of CMV-specific IgM antibody bound was determined by measuring the intensity of color change after the addition of peroxidase-labeled CMV antigen and substrate. Nuclei of infected cells served as an antigen source. CMV IgM could be detected only in IgM fractions of sera from patients with a recent CMV infection. Rheumatoid factor did not cause false-positive results. No cross-reactions were observed when paired sera from 22 patients with herpes simplex or varicella and single sera from 12 patients with suspected infectious mononucleosis were tested by the direct enzyme-linked immunosorbent assay. Each of 17 patients with a seroconversion for CMV antibody showed CMV-specific IgM antibody. In six of these patients the antibody was detected in the initial serum. The direct enzyme-linked immunosorbent assay for CMV IgM is a specific and sensitive test for the diagnosis of recent CMV infections and possesses distinct advantages over indirect tests.

Antibodies, Viral↗
PubMed1981

Enzyme-linked immunosorbent assay for measurement of antibody against cytomegalovirus and rubella virus in a single serum dilution.

Enzyme-linked immunosorbent assays (ELISA) were developed for quantifying cytomegalovirus (CMV) and rubella antibodies using a single serum dilution (1/800) in conjunction with a standard curve. A near linear relation was found between the logarithms of absorbance values of sera at a dilution of 1/800 and the titres as determined by an end point dilution ELISA. The reproducibility of the single dilution ELISA was good; the within-test coefficients of variation averaged 7.5% for CMV antibody and 12.4% for rubella antibody. A close correlation was found between ELISA and complement-fixing (CF) antibody titres to CMV and between ELISA and haemagglutination-inhibition (HI) antibody titres to rubella virus. The titres in ELISA were 200 to 1000 times higher than in CF for CMV and 50 to 100 times higher than in HI for rubella virus.

Antibodies, Viral↗
PubMed1980

Epidemiology of hepatitis A in Amsterdam, October 1978--December 1979.

The epidemiology of hepatitis A was studied in Amsterdam during a 15 month period from October 1978 through December 1979. 349 cases of viral hepatitis were reported of which 135 were serologically identified as hepatitis A. The diagnosis was established by testing a single acute-phase serum sample with ELISA for the detection of hepatitis A IgM antibodies. Most cases were sporadic; there were no outbreaks involving more than three cases. A seasonal variation was recognized with the highest incidence in later autumn and early winter. The peak attack rate was found in the age group of 5--9 and a smaller peak was noticed in the age group of 30--34. Recent exposure to a known case of hepatitis A or to a jaundiced person was the probable source of infection in 27% of the patients; 23% contracted hepatitis A within 7 weeks of visiting a tropical or subtropical country and in 50% no source was found. 50 patients provided stool specimens within 2 weeks of the onset of jaundice. Specimens were examined for the presence of hepatitis A virus antigen by ELISA and seven patients had positive stools, all within the first week of the onset of jaundice.

Age Factors↗
PubMed1980

Prevalence of toxoplasma antibodies according to age with comments on the risk of prenatal infection.

Sera from 1661 persons in 12 age groups from 0 to 79 years were titrated for toxoplasma antibodies in the indirect immunofluorescence test. The sera were collected from patients with symptoms suggestive of acute, mainly respiratory, viral infections. After the first year of life, the prevalence of antibodies started to rise, reaching 59% between 40 and 79 years of age. From the prevalence of antibodies in different age groups the annual infection risk, i.e, the risk of a non-immune person acquiring toxoplasma infection, was estimated for successive age periods. The estimated annual infection risk increased from 0 . 5% in early childhood to 3% during adolescence and early adult life. Approximately 70--80% of females entered the age of reproduction without evidence of seroimmunity to toxoplasma. The risk of primary infection during pregnancy was estimated from the age distribution of parturient women in The Netherlands in 1975 and the age-specific incidence of primary infections, i.e. the incidence in the total population of susceptible and immune persons. This incidence of primary infection decreased from 1 . 62% per 9 months at the age of 17 1/2--20 years to 0 . 37% at the age of 37--45 years. The incidence of primary infections in pregnant women was estimated to be 1 . 25%.

Adolescent↗