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S de Blok

Publications and source records attributed to S de Blok.

12 recordsLinked to original sources
PubMed2002

Localization and staging of cervical intraepithelial neoplasia using double ratio fluorescence imaging.

A phase zero evaluation of a new fluorescence imaging technique for diagnosing cervical intraepithelial neoplasia (CIN) was performed. The fluorescence imaging prototype performed quantitative imaging of Protoporphyrin induced by a topically applied aminolevulinic acid using double ratio (DR) fluorescence imaging technique developed by our group. A total of 38 patients were in the protocol, with 16 colposcopically selected for biopsy. Fluorescence images of these 16 patients were taken, 19 sites were biopsied, and the disease was staged histopathologically. DR fluorescence imaging of the cervix using our general purpose prototype appeared to be cumbersome but feasible. In four cases strongly localized fluorescent hotspots were observed at the location where the disease was colposcopically visible. In the other cases the fluorescence showed a more diffuse multifocal image. The value of the DR determined at the site of biopsy correlated in a statistically significant way with the histopathologically determined stage of the disease [Spearman rank correlation, r=0.881, p<0.001 (confidence interval 0.7044-0.9552)]. This suggests that noninvasive staging of CIN using this technique is feasible. We believe that the results of this study justify the development of a dedicated device that combines regular white light colposcopy with DR fluorescence imaging.

Adult↗
PubMed2002

Virilisation.

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Adult↗
PubMed2000

Decrease in the number of abdominal hysterectomies after introduction of laparoscopic hysterectomy.

STUDY OBJECTIVE: To compare two 3-year periods before and after laparoscopic hysterectomy was introduced into our resident training program. DESIGN: Retrospective analysis (Canadian Task Force classification II-2). SETTING: Teaching hospital in the Netherlands. PATIENTS: Women undergoing hysterectomy from 1992 to 1994 and 1995 to 1997. INTERVENTION: Abdominal, vaginal, and laparoscopic hysterectomies. MEASUREMENTS AND MAIN RESULTS: Laparoscopic hysterectomy significantly (p<0.002) reduced the number of abdominal hysterectomies. CONCLUSION: To reduce the number of abdominal hysterectomies, it is essential that the laparoscopic procedure be taught to residents.

Adult↗
PubMed2000

Urogenital Chlamydia trachomatis serovars in men and women with a symptomatic or asymptomatic infection: an association with clinical manifestations?

To determine whether certain Chlamydia trachomatis serovars are preferentially associated with a symptomatic or an asymptomatic course of infection, C. trachomatis serovar distributions were analyzed in symptomatically and asymptomatically infected persons. Furthermore, a possible association between C. trachomatis serovars and specific clinical symptoms was investigated. C. trachomatis-positive urine specimens from 219 asymptomatically infected men and women were obtained from population-based screening programs in Amsterdam. Two hundred twenty-one C. trachomatis-positive cervical and urethral swabs from symptomatically and asymptomatically infected men and women were obtained from several hospital-based departments. Serovars were determined using PCR-based genotyping, i.e., restriction fragment length polymorphism analysis of the nested-PCR-amplified omp1 gene. The most prevalent C. trachomatis serovars, D, E, and F, showed no association with either a symptomatic or asymptomatic course of infection. The most prominent differences found were (i) the association of serovar Ga with symptoms in men (P = 0.0027), specifically, dysuria (P < 0.0001), and (ii) detection of serovar Ia more often in asymptomatically infected people (men and women) (P = 0.035). Furthermore, in women, serovar K was associated with vaginal discharge (P = 0.002) and serovar variants were found only in women (P = 0.045).

Adolescent↗
PubMed1998

Monitoring of Chlamydia trachomatis infections after antibiotic treatment using RNA detection by nucleic acid sequence based amplification.

AIM: To investigate the value of RNA detection by nucleic acid sequence based amplification (NASBA) for the monitoring of Chlamydia trachomatis infections after antibiotic treatment. METHODS: Cervical smears (n = 97) and urine specimens (n = 61) from 25 C trachomatis positive female patients were analysed for the presence of C trachomatis 16S ribosomal RNA (rRNA) by NASBA and C trachomatis plasmid DNA by the polymerase chain reaction (PCR) before and up to five weeks after antibiotic treatment. RESULTS: Chlamydia trachomatis RNA was found in all cervical smears taken before antibiotic treatment (n = 24) and in two smears taken one week after antibiotic treatment; no C trachomatis RNA was detected after two weeks or more. In contrast, C trachomatis DNA was found in all such specimens before treatment, and 21 of 25, six of 21, and five of 20 smears were found to be positive at one, two, and three weeks after treatment, respectively. After four weeks, only one of six smears was positive, and this smear had been negative in the two preceding weeks. Of the 61 urine samples investigated, C trachomatis DNA and C trachomatis RNA were found in all before treatment (n = 15), whereas one week after treatment four of 15 were C trachomatis DNA positive and C trachomatis RNA was detected in one sample only. CONCLUSIONS: These data show that RNA detection by NASBA can be used successfully to monitor C trachomatis infections after antibiotic treatment. Furthermore, it might be possible to use urine specimens as a test of cure because neither C. trachomatis DNA or RNA could be detected two weeks or more after treatment.

Anti-Bacterial Agents↗
PubMed1996

RNA amplification by nucleic acid sequence-based amplification with an internal standard enables reliable detection of Chlamydia trachomatis in cervical scrapings and urine samples.

In the present study, the suitability of RNA amplification by nucleic acid sequence-based amplification (NASBA) for the detection of Chlamydia trachomatis infection was investigated. When comparing different primer sets for their sensitivities in NASBA, use of both the plasmid and omp1 targets resulted in a detection limit of 1 inclusion-forming unit (IFU), while the 16S rRNA appeared to be the most sensitive RNA target for amplification (10(-3) IFU). In contrast, for DNA amplification by PCR, the plasmid target was optimal (10(-2) IFU), which is 10 times less sensitive than rRNA NASBA. To exclude false negativity in NASBA detection because of inhibition of amplification and/or inefficient sample preparation, an internal standard was developed. The internal control was added prior to sample preparation. This 16S rRNA NASBA with an internal control was compared with a plasmid DNA PCR by using a group of C. trachomatis-negative (n = 41) and -positive (n = 37) cervical scrapings, as determined by enzyme immunoassay (EIA). In addition, urine samples from the EIA-positive women were tested (n = 17). Both NASBA and PCR assays were able to detect C. trachomatis in all EIA-positive cervical scrapings, the corresponding urine samples, and two samples from the EIA-negative group. The internal NASBA standard was found clearly in all EIA-negative samples. In conclusion, these results indicate that detection of C. trachomatis by RNA amplification by NASBA with an internal standard is a suitable and highly sensitive detection method, with potential use in the diagnosis of urogenital C. trachomatis infections with cervical scrapings as well as urine specimens.

Bacterial Outer Membrane Proteins↗
PubMed1992

[Hysteroscopy].

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Biopsy↗
PubMed1980

The fibrous tissue architecture of the female perineal region.

In relation to the question which type of episiotomy should be preferred, the subcutaneous layer of the anatomical perineum of three adult female subjects was bluntly dissected. In the urogenital triangle constantly five fibrous septa were observed, and in the posterior (anal) triangle several antero-posterior septa as well as septa radiating from the walls of the anal canal and the vagina. In addition, dense connective tissue structures overly the ischial tuberosity. Microscopical studies showed that all septa contain blood vessels and bundles of smooth muscle fibres. Only the dorsal, median septum which connects the anal canal to the coccyx, contains bundles of striated muscle fibres, too. The results show that only the median episiotomy leaves the system of subcutaneous perineal fibrous tissue septa unimpaired.

Adipose Tissue↗