PubMed Health⌕ Search

Biomedical subjects

S Kuijper

Publications and source records attributed to S Kuijper.

At least 19 recordsLinked to original sources
PubMed2006

Cytokine response to antigen stimulation of whole blood from patients with Mycobacterium ulcerans disease compared to that from patients with tuberculosis.

Mycobacterium ulcerans disease (Buruli ulcer) is a skin-ulcerating infection common in some parts of the tropics. We have investigated cytokine secretion after stimulation of whole blood from Buruli ulcer (BU) patients in a region of endemicity in Ghana with M. ulcerans sonicate or culture filtrate antigens to investigate the development of the response over time and its specificity by comparison with the response to Mycobacterium tuberculosis sonicate in human immunodeficiency virus-negative tuberculosis patients. Significant gamma interferon (IFN-gamma) production in response to whole-blood stimulation with M. ulcerans sonicate was detected in patients with ulcers, which was higher than that in patients with nodules but similar to subjects with healed BU. The mean IFN-gamma response in household contacts of BU patients was not significantly different from that in healthy control subjects from an area of nonendemicity. Results in patients with untreated, smear-positive pulmonary tuberculosis and tuberculosis patients on treatment for more than 2 weeks showed that BU patients responded better to M. ulcerans antigens than tuberculosis patients. In contrast, interleukin-10 results were higher in patients with active M. ulcerans disease than in those with healed lesions, but the pattern of response was similar to that seen in tuberculosis. A similar pattern of cytokine secretion was found using M. tuberculosis sonicate as an antigen. Neither of the two culture filtrate antigens of M. ulcerans appeared to be more specific than M. ulcerans sonicate. In the early stages of M. ulcerans disease there was a mixed Th1 and Th2 cytokine response, but the Th1 response emerged as the dominant type.

Adolescent↗
PubMed2006

Light emitting diodes for auramine O fluorescence microscopic screening of Mycobacterium tuberculosis.

We describe the simple adaptation of a standard fluorescent microscope for illumination using a 'Royal Blue' Luxeon light emitting diode (LED) and demonstrate that this form of illumination is suitable for the detection of auramine O stained Mycobacterium spp. The low cost, low power consumption, safety and reliability of LEDs makes them attractive alternatives to mercury vapour lamps.

Benzophenoneidum↗
PubMed2005

Sensitivity of PCR targeting the IS2404 insertion sequence of Mycobacterium ulcerans in an Assay using punch biopsy specimens for diagnosis of Buruli ulcer.

Punch biopsy specimens from Mycobacterium ulcerans disease lesions were used to compare the sensitivities and specificities of direct smear, culture, PCR, and histopathology in making a diagnosis of M. ulcerans disease in a field setting. PCR for the insertion element IS2404 was modified to include uracil-N-glycosylase and deoxyuridine triphosphate instead of deoxythymidine triphosphate to reduce the risk of cross contamination. The "gold standard" for confirmation of clinically diagnosed Buruli ulcer was a definite histological diagnosis, a positive culture for M. ulcerans, or a smear positive for acid-fast bacilli (AFB), together with a possible histological diagnosis. For 70 clinically diagnosed cases of M. ulcerans disease, the modified PCR was 98% sensitive and gave a rapid result. The sensitivities of microscopy, culture, and histology were 42%, 49%, and 82%, respectively. The use of a 4-mm punch biopsy specimen was preferred to a 6-mm punch biopsy specimen since the wound was less likely to bleed and to need stitching. Given adequate technical expertise and the use of controls, the PCR was viable in a teaching hospital setting in Ghana; and in routine practice, we would recommend the use of Ziehl-Neelsen staining of biopsy specimens to detect AFB, followed by PCR, in AFB-negative cases only, in order to minimize costs. Histology and culture remain important as quality control tests, particularly in studies of treatment efficacy.

Adolescent↗
PubMed2004

In vitro killing of Mycobacterium ulcerans by acidified nitrite.

Mycobacterium ulcerans, which causes Buruli ulcer, was exposed to acidified nitrite or to acid alone for 10 or 20 min. Killing was rapid, and viable counts were reduced below detectable limits within 10 min of exposure to 40 mM acidified nitrite. M. ulcerans is highly susceptible to acidified nitrite in vitro.

Acids↗
PubMed2002

1 Patterning the limb before and after SHH.

The Summer Meeting of the Anatomical Society of Great Britain and Ireland was held at the University of Dundee, from 23rd to 25th July 2002. It included a symposium on 'How to make a hand'. The following are abstracts of communications and posters presented at the meeting.

Journal Article↗
PubMed2000

Development of antigen detection assay for diagnosis of tuberculosis using sputum samples.

The rising incidence of tuberculosis worldwide means an increasing burden on diagnostic facilities, so tests simpler than Ziehl-Neelsen staining are needed. Such tests should be objective, reproducible, and have at least as good a detection limit as 10(4) bacteria/ml. A capture enzyme-linked immunosorbent assay (ELISA) was developed for detection of lipoarabinomannan (LAM) in human sputum samples. As a capture antibody, we used a murine monoclonal antibody against LAM, with rabbit antiserum against Mycobacterium tuberculosis as a source of detector antibodies. The sensitivity of the capture ELISA was evaluated by using purified LAM and M. tuberculosis whole cells. We were able to detect 1 ng of purified LAM/ml and 10(4) M. tuberculosis whole cells/ml. LAM could also be detected in culture filtrate of a 3-week-old culture of M. tuberculosis. The culture filtrate contained approximately 100 microgram of LAM/ml. The detection limit in sputum pretreated with N-acetyl-L-cysteine and proteinase K was 10(4) M. tuberculosis whole cells per ml. Thirty-one (91%) of 34 sputum samples from 18 Vietnamese patients with tuberculosis (32 smear positive and 2 smear negative) were positive in the LAM detection assay. In contrast, none of the 25 sputum samples from 21 nontuberculous patients was positive. This specific and sensitive assay for the detection of LAM in sputum is potentially useful for the diagnosis of tuberculosis.

Antibodies, Bacterial↗
PubMed2000

Polymerase chain reaction based method for the detection of BCG retention after intravesical instillation in guinea pig bladders.

OBJECTIVE: In intravesical Bacille bilié de Calmette-Guérin (BCG) immunotherapy of superficial bladder cancer, a T cell mediated immunological reaction is associated with the antitumor activity. To gain insight into the approximate number of BCG bacteria retained in the normal, noninjured, urinary bladder after intravesical application responsible for induction of the immune reaction, the utility of a sensitive polymerase chain reaction (PCR) based assay was investigated in a guinea pig model. METHODS: After one single or six subsequent weekly instillations with 1x10(7) CFU of BCG, the bladders were resected and processed for BCG determination with PCR. The bladders were resected 24 h after instillation, aiming at (semi)quantifying the number of BCG organisms able to resist the natural voiding washout of the bladder. The PCR was based on amplification of a 249 base pair fragment of the insertion element IS6110 and is specific for bacteria belonging to the Mycobacterium tuberculosis complex which includes Mycobacterium bovis BCG. RESULTS: After one single instillation no detectable BCG retention was found. However, after six weekly instillations, BCG bacteria could be demonstrated in 2 out of 5 guinea pig bladders, indicating that the number of adhering BCG organisms was around the detection limit of the assay (600-1,000 BCG bacteria per bladder). CONCLUSIONS: The data suggest that after six instillations, the retention of BCG in the guinea pig bladder is enhanced as compared with one single instillation. This finding is suggestive of a role of the inflammatory process that is, besides immune system mediated reactions, associated with intravesical BCG instillations. The nature of the molecules involved in enhanced BCG retention after repeated instillations remains to be investigated.

Administration, Intravesical↗
PubMed1998

Stabilized, freeze-dried PCR mix for detection of mycobacteria.

We report here the development of a freeze-drying procedure allowing stabilization at ambient temperature of preoptimized, premixed, and predispensed PCR mixes aimed at the detection of mycobacteria in clinical materials. The freeze-dried mixes retained activity at 4 degrees C and at 20 degrees C for 1 year and for 3 months at 37 degrees C, as judged by their performance with 50 and 500 fg of purified Mycobacterium bovis BCG target DNA.

DNA, Bacterial↗
PubMed1998

Clinical utility of the polymerase chain reaction in the diagnosis of extrapulmonary tuberculosis.

This study examines the diagnostic utility of the polymerase chain reaction (PCR) in 156 patients (five human immunodeficiency virus (HIV) seropositive) suspected of extrapulmonary tuberculosis. The results of PCR in 226 samples from 11 different sites were compared with the results of microscopy and culture. Positive culture results were predicted in 86% of samples by PCR but in only 31% by microscopy. Specificity of PCR was 92%. In cases with culture-proven tuberculosis, PCR identified all 11 microscopy positive cases and 19 of 24 (79%) of the microscopy-negative cases. In four patients, PCR excluded the diagnosis of tuberculosis in microscopy-positive samples, which were later shown to contain mycobacteria other than Mycobacterium tuberculosis or laboratory contaminants. In 20 patients (microscopy, PCR and culture negative) a trial of antituberculous drugs was given, but patients showed no improvement and treatment was stopped. In 17 patients, all culture negative (in nine PCR was positive, three of whom also had positive microscopy) the diagnosis was probable tuberculosis based on clinical findings and response to treatment. This polymerase chain reaction has a much higher sensitivity than microscopy and can facilitate therapeutic decisions for those with suspected extrapulmonary tuberculosis.

AIDS-Related Opportunistic Infections↗
PubMed1997

Simultaneous detection and strain differentiation of Mycobacterium tuberculosis for diagnosis and epidemiology.

Widespread use of DNA restriction fragment length polymorphism (RFLP) to differentiate strains of Mycobacterium tuberculosis to monitor the transmission of tuberculosis has been hampered by the need to culture this slow-growing organism and by the level of technical sophistication needed for RFLP typing. We have developed a simple method which allows simultaneous detection and typing of M. tuberculosis in clinical specimens and reduces the time between suspicion of the disease and typing from 1 or several months to 1 or 3 days. The method is based on polymorphism of the chromosomal DR locus, which contains a variable number of short direct repeats interspersed with nonrepetitive spacers. The method is referred to as spacer oligotyping or "spoligotyping" because it is based on strain-dependent hybridization patterns of in vitro-amplified DNA with multiple spacer oligonucleotides. Most of the clinical isolates tested showed unique hybridization patterns, whereas outbreak strains shared the same spoligotype. The types obtained from direct examination of clinical samples were identical to those obtained by using DNA from cultured M. tuberculosis. This novel preliminary study shows that the novel method may be a useful tool for rapid disclosure of linked outbreak cases in a community, in hospitals, or in other institutions and for monitoring of transmission of multidrug-resistant M. tuberculosis. Unexpectedly, spoligotyping was found to differentiate M. bovis from M. tuberculosis, a distinction which is often difficult to make by traditional methods.

Bacterial Typing Techniques↗
PubMed1997

Multiplex PCR assay for immediate identification of the infecting species in patients with mycobacterial disease.

Rapid identification of infecting mycobacterial species enables appropriate medical care decisions to be made. Our aim was to demonstrate the clinical usefulness of the multiplex PCR assay, a test based on PCR, which permits direct identification of 12 mycobacterial species in clinical specimens. A total of 259 specimens from 177 patients who had clinical symptoms of mycobacterial disease but for whom there were difficulties in diagnosis were tested. Specimens were analyzed within 48 h of receipt of the sample. Mycobacteria were identified in 102 specimens; 66 specimens contained nontuberculous mycobacteria, and 36 specimens contained Mycobacterium tuberculosis complex mycobacteria. The PCR assay identified the mycobacterial species in 43 (97.7%) of 44 microscopy- and culture-positive specimens and in 15 (93.8%) of 16 culture-positive, microscopy-negative specimens. It also permitted species identification in infections caused by more than one mycobacterial species. For 56 (96.5%) of the 58 specimens from patients with infections caused by opportunistic mycobacteria, the organisms were identified with the PCR assay. The test was useful also for the identification of fastidious mycobacteria, e.g., M. genavense, and those that cannot be cultured, e.g., M. leprae. After resolution of discrepant results, the sensitivity of the PCR assay was 97.9%, the specificity was 96.9%, the positive predictive value was 95.0%, and the negative predictive value was 98.7%. For culture these values were 60.8, 100, 100, and 81.0%, respectively. Thus, the multiplex PCR assay enables prompt diagnosis when rapid identification of infecting mycobacteria is necessary.

AIDS-Related Opportunistic Infections↗
PubMed1996

The potential contribution of the polymerase chain reaction to the diagnosis of tuberculous meningitis.

OBJECTIVE: To examine diagnostic utility of polymerase chain reaction (PCR) on cerebrospinal fluid (CSF) in tuberculous meningitis (TBM). DESIGN: Comparison study. SETTING: Referral center for tuberculosis diagnosis and treatment in Ho Chi Minh City, Vietnam, and research laboratory in Amsterdam, the Netherlands. PATIENTS: One hundred thirty-six consecutive patients, aged 4 months to 85 years, with features compatible with TBM seen during a 12-month period. MEASUREMENTS: Clinical examination; cytology; Gram, india ink, and Ziehl-Neelsen staining; culture of CSF for bacteria, mycobacteria, fungi, and viruses; and CSF chloride, protein, and glucose. All these tests were performed in Vietnam. The PCR on CSF was performed in the Netherlands. RESULTS: Patients were managed in Vietnam without knowledge of PCR results. Based on clinical grounds and the results of initial CSF microscopy, antituberculous treatment was given to 104 patients, 66 of whom had evidence of extraneural tuberculosis. Among the 39 patients with confirmed TBM (ie, positive Ziehl-Neelsen staining or culture or PCR results for Mycobacterium tuberculosis), PCR detected 32 patients (82%), 1 case was proven positive through microscopy and 17 (44%) had positive culture results. There were no false-positive PCR results. In 99 patients with a final diagnosis of confirmed or probable TBM (ie, clinical features of TBM and response to antituberculous treatment), PCR had a sensitivity of 32%; culture, 17% and microscopy, 1%. CONCLUSIONS: Many patients who respond to treatment for TBM do not have M tuberculosis in the CSF identifiable by microscopy, PCR, or culture. Polymerase chain reaction on CSF is the best method for the laboratory diagnosis of TBM. Polymerase chain reaction is especially useful for the early diagnosis of TBM in those without active extraneural tuberculosis.

Adolescent↗
PubMed1995

Early diagnosis of tuberculous meningitis by polymerase chain reaction.

BACKGROUND: Rapid detection of Mycobacterium tuberculosis is of vital importance for patients with tuberculous meningitis. We evaluated an improved polymerase chain reaction (PCR) technique for rapid and specific identification of M tuberculosis in CSF. METHODS: The technique was used on CSF samples from 42 patients (3 of whom were human immunodeficiency virus seropositive) with clinical symptoms, signs and laboratory findings suggestive of tuberculous meningitis. The target for amplification was a nucleotide sequence located within IS6110. A small amount of DNA from M smegmatis strain 1008, containing a modified IS6110, was added in the PCR as a control for inhibitors and to quantitate the PCR for M tuberculosis. RESULTS: On the basis of symptoms and clinical findings, antituberculous treatment was started in 35 patients, but was later stopped in 11 because of lack of response. From 12 patients responding to treatment and with a positive diagnostic test, 11 cases were detected by PCR, nine cases were culture positive, and two cases microscopy positive. Of the remaining 12 patients who had negative CSF by microscopy, PCR, and culture, 11 were diagnosed as having tuberculous meningitis on the basis of the response to treatment (three had active pulmonary tuberculosis) and one had mycobacteria other than M tuberculosis in sputum and urine. The sensitivity of the PCR was 48% in those with a final diagnosis of tuberculous meningitis (culture or PCR confirmed cases, plus those with clinical evidence and who responded to antituberculous treatment), which is much higher than the 9% sensitivity of microscopy. There were no false-positive PCR results. CONCLUSIONS: PCR on CSF is a rapid method for the accurate diagnosis of tuberculous meningitis.

Adolescent↗
PubMed1994

A more reliable PCR for detection of Mycobacterium tuberculosis in clinical samples.

Diagnostic techniques based on PCR have two major problems: false-positive reactions due to contamination with DNA fragments from previous PCRs (amplicons) and false-negative reactions caused by inhibitors that interfere with the PCR. We have improved our previously reported PCR based on the amplification of a fragment of the Mycobacterium tuberculosis complex-specific insertion element IS6110 with respect to both problems. False-positive reactions caused by amplicon contamination were prevented by the use of uracil-N-glycosylase and dUTP instead of dTTP. We selected a new set of primers outside the region spanned by the formerly used primers to avoid false-positive reactions caused by dTTP-containing amplicons still present in the laboratory. With this new primer set, 16 copies of the IS6110 insertion element, the equivalent of two bacteria, could be amplified 10(10) times in 40 cycles, resulting in a mean efficiency of 77% per cycle. To detect the presence of inhibitors of the Taq polymerase, which may cause false-negative reactions, part of each sample was spiked with M. tuberculosis DNA. The DNA purification method using guanidinium thiocyanate and diatoms effectively removed most or all inhibitors of the PCR. However, this was not suitable for blood samples, for which we developed a proteinase K treatment followed by phenol-chloroform extraction. This method permitted detection of 20 M. tuberculosis bacteria per ml of whole blood. Various laboratory procedures were introduced to reduce failure or inhibition of PCR and avoid DNA cross contamination. We have tested 218 different clinical specimens obtained from patients suspected of having tuberculosis. The samples included sputum (n=145), tissue biopsy samples (n=25), cerebrospinal fluid (n=15), blood (n=14), pleural fluid (n=9), feces, (n=7), fluid from fistulae (n=2), and pus from a wound (n=1). The results obtained by PCR were consistent with those obtained with culture, which is the "gold standard." We demonstrate that PCR is a useful technique for the rapid diagnosis of tuberculosis at various sites.

Bacteriological Techniques↗
PubMed1994

Mycobacterium smegmatis strain for detection of Mycobacterium tuberculosis by PCR used as internal control for inhibition of amplification and for quantification of bacteria.

For the detection of Mycobacterium tuberculosis by PCR, the IS6110 sequence was used. A modified target was constructed by insertion of 56 nucleotides in the IS6110 insertion element of Mycobacterium bovis BCG. This modified insertion sequence was integrated into the genome of Mycobacterium smegmatis, a mycobacterium species which does not contain the IS6110 element. When DNA from the modified M. smegmatis 1008 strain was amplified with IS6110-specific primers INS1 and INS2, a band of 301 bp was seen on agarose gel, whereas the PCR product of M. tuberculosis complex DNA was a 245-bp fragment with these primers. The addition of a small number of M. smegmatis 1008 cells to clinical samples before DNA purification enables the detection of problems which may be due to the loss of DNA in the isolation procedure or to the presence of inhibitors. The presence of inhibitors of the amplification reaction can be confirmed by the addition of M. smegmatis 1008 DNA after the DNA isolation procedure. Furthermore, competition between the different target DNAs of M. smegmatis 1008 DNA and M. tuberculosis complex DNA enables the estimation of the number of IS6110 elements in the clinical sample.

Base Sequence↗
PubMed1993

Identification of a novel 27-kDa protein from Mycobacterium tuberculosis culture fluid by a monoclonal antibody specific for the Mycobacterium tuberculosis complex.

Mycobacterium tuberculosis antigens inducing species-specific immune responses are likely to be particularly important for serodiagnosis or for skin testing of tuberculosis. In the present study, we describe the characterization of two novel monoclonal antibodies (MoAbs) A3h4 (IgG2a) and B5g1 (IgM) that are directed to M. tuberculosis 27-kDa and 25-kDa proteins respectively. Specificity analysis by immunoblotting using 20 different species of mycobacterial sonicates revealed that MoAb A3h4 was specific for M. tuberculosis complex alone while MoAb B5g1 showed a limited cross-reactivity. Direct comparison with previously characterized MoAbs revealed that these MoAbs A3h4 and B5g1 defined new antigenic determinants of M. tuberculosis. By using M. tuberculosis complex-specific MoAb A3h4 we have identified a distinct 27-kDa protein in the M. tuberculosis H37Rv culture fluid. Since this MoAb did not bind to the previously characterized MPT44, MPT59, MPT45, MPT51 and MPT64 proteins as well as the 23-kDa superoxide dismutase (SOD) protein of M. tuberculosis, we conclude that MoAb A3h4 recognizes a novel protein in the M. tuberculosis H37Rv culture fluid. Studies of the subcellular distribution of these MoAb-reactive proteins indicate that the MoAb A3h4-reactive 27-kDa protein is present not only in the culture fluid but also in the cytosol and the cell wall of M. tuberculosis. By contrast, B5g1-reactive protein is mainly a cytosolic protein. When these MoAbs were tested in a previously established ELISA with intact mycobacteria derived from early cultures, only MoAb A3h4 showed the positive reactivity to mycobacteria belonging to the M. tuberculosis complex. In addition, during the present comparative studies of MoAbs we have also found that the previously described MoAb F116-5, which is known to recognize the mycobacterial 23-kDa SOD protein [17], cross-reacted with the MPT44, MPT59, MPT45 and MPT51 secreted proteins but not with MPT64 and MPB70. These findings indicate that the family of four secreted proteins of M. tuberculosis share a common epitope with M. tuberculosis SOD protein.

Antibodies, Monoclonal↗