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Biomedical subjects

A De Rouck

Publications and source records attributed to A De Rouck.

At least 19 recordsLinked to original sources
PubMed1995

Evaluation of the applicability of amplified rDNA-restriction analysis (ARDRA) to identification of species of the genus Corynebacterium.

The 16S rRNA genes (rDNA) of 50 strains belonging to 26 different coryneform bacterial species and genomospecies and of the type strain of Rhodococcus equi were enzymatically amplified. Amplified rDNA restriction analysis (ARDRA) with the enzymes AluI, CfoI and RsaI was carried out. The combination of the ARDRA patterns obtained after restriction with these three different enzymes enabled the differentiation between the following species: Corynebacterium accolens (number of strains = 2), C. afermentans subsp. afermentans (2), C. afermentans subsp. lipophilum (2), C. amycolatum (3), CDC coryneform group ANF-1-like (1), CDC coryneform group ANF-3-like (1), C. cystitidis (1), C. diphtheriae (4), C. jeikeium (3), C. macginleyi (2), C. minutissimum (1), C. pilosum (1), C. pseudotuberculosis (2), C. renale (2), C. striatum (2), C. urealyticum (3), C. xerosis (1), CDC coryneform groups B-1 (2), B-3 (2), F-1, genomospecies 1 and 2 (6), G, genomospecies 1 (1) and G, genomospecies 2 (2). The following strains or species could not be differentiated from each other: C. pseudodiphtheriticum (2) from C. propinquum (former CDC coryneform group ANF-3) (2), CDC coryneform group F-1, genomospecies 1 (4) from genomospecies 2 (2) and C. jeikeium genomospecies A (1) from genomospecies C (2). ARDRA may represent a possible alternative for identification of coryneforms, since this technique enabled the identification of most coryneforms tested and since DNA extraction (i.e. cell lysis by boiling), amplification, restriction and electrophoresis can be carried out within 8 hours. This might allow quick identification of C. diphtheriae and other possible pathogens of the genus Corynebacterium.

Corynebacterium↗
PubMed1994

X linked progressive cone dystrophy. Localisation of the gene locus to Xp21-p11.1 by linkage analysis.

Six affected males, three female carriers, and two possible carriers were evaluated from a three generation pedigree with X linked progressive cone dystrophy. The affected males presented with progressive decrease of visual acuity, impairment of colour vision, and deterioration of electroretinogram, which ranged from absent response to red light in all young patients to abnormal cone-rod responses in the elderly ones. In most affected males dark adaptation curves were monophasic and the electro-oculogram values were reduced. While some obligate carriers showed functional anomalies, they all had reduced electroretinogram response to red light. The a1/aT ratio for 1 joule white light was an appropriate indicator for carrier state. The family was studied with seven DNA markers from the proximal part of the short arm of the human X chromosome. So far, significant linkage has been found between three DNA markers and COD1, which assigns the progressive cone dystrophy gene (COD1) in this family to Xp21-p11.1. Differential diagnosis with congenital cone dystrophies is discussed.

Adult↗
PubMed1993

Identification of Mycobacterium species by using amplified ribosomal DNA restriction analysis.

A rapid procedure for the identification of cultured Mycobacterium isolates, based on the combination of enzymatic amplification and restriction analysis, is described. The 16S rRNA genes (rDNA) of 99 strains belonging to 18 different species of the genus Mycobacterium were enzymatically amplified. Amplified rDNA restriction analysis with the enzymes CfoI, MboI, and RsaI was carried out. The combination of the amplified rDNA restriction analysis patterns obtained after restriction with CfoI and MboI enabled differentiation between Mycobacterium asiaticum (number of strains = 4), M. avium (n = 22), M. chelonae (n = 5), M. flavescens (n = 1), M. fortuitum (n = 6), M. gordonae (n = 6), M. intracellulare (n = 13), M. marinum (n = 7), M. nonchromogenicum (n = 1), M. simiae (n = 5), M. terrae (n = 5), the M. tuberculosis complex (n = 11), and 2 of 4 strains of M. xenopi. Further restriction with RsaI was necessary to differentiate between the species M. kansasii (n = 5), M. scrofulaceum (n = 4), and the 2 other M. xenopi strains. The M. avium-M. intracellulare complex was characterized by a specific MboI pattern, and M. avium and M. intracellulare strains could further be differentiated by restriction with CfoI. The whole procedure, including sample preparation prior to the polymerase chain reaction, can be carried out within 8 h, starting from a pure culture.

Base Sequence↗
PubMed1992

Rapid identification of bacteria of the Comamonadaceae with amplified ribosomal DNA-restriction analysis (ARDRA).

Ribosomal rRNA gene fragments (rDNA) encompassing the 16S rDNA, the 16S-23S rDNA spacer region and part of the 23S rDNA of 95 strains belonging to 13 well-described taxa of the eubacterial family Comamonadaceae (beta subclass of the Proteobacteria or rRNA superfamily III) were enzymatically amplified using conserved primers. The fragments of approximately 2400 base pairs were subjected to restriction analysis. Restriction fragment length patterns obtained with HinfI enabled us to distinguish 9 of the 13 taxa studied. Restriction with CfoI was necessary to differentiate Acidovorax delafieldii from A. temperans and Hydrogenophaga flava from H. pseudoflava. The results indicate that amplified rDNA restriction analysis is a simple and reliable tool for the identification of bacterial species.

Base Sequence↗
PubMed1988

Electrophysiologic studies in birdshot chorioretinopathy.

We investigated retinal function in 16 patients with birdshot chorioretinopathy. Consistent abnormalities of dark adaptation, color vision, visual field, electro-oculography, electroretinography, and visual-evoked cortical potentials were found. They included raised thresholds of dark adaptation, acquired dyschromatopsia, mainly of the blue-yellow type, an electroretinogram with reduced amplitude, increased latency of the b-wave and absent oscillatory potentials, an abnormal electro-oculogram, and in many a marked disturbance in the pattern reversal visual-evoked cortical potential. The a-wave of the electroretinogram, the fast oscillations of the standing potential, and the flash visual-evoked cortical potential were well preserved. The nature of the abnormalities suggests that dysfunction was caused by inner retinal disease. Little evidence indicated outer retinal dysfunction resulting from choroidal inflammation.

Adult↗
PubMed1986

Statistical evaluation of visual functions in dominant and recessive autosomal pigmentary retinopathy.

A statistical study of the progress of fundus lesions and functional loss in relation with age and with inheritance modus was performed in patients with pigmentary retinopathy. A three-way interaction was found between following parameters: inheritance modus, age and pigment anomalies of the fundus; inheritance modus, age and visual field; inheritance modus, age and ERG; inheritance modus, vision and ERG; inheritance modus, dark adaptation and visual field.

Adolescent↗
PubMed1986

Chronic carbon disulphide poisoning: a 4 year follow-up study of the ophthalmological signs.

Thirty workers of a viscose rayon industry had a complete eye examination in 1979 including visual acuity, perimetry, colour vision testing, fluorescein angiography, ERG and EOG, for possible signs of chronic carbon disulphide poisoning. They were divided into two groups, group A included workers exposed to relatively high CS2 levels (at least 50 mg/m3), group B working in the relatively safe bleaching division. In both groups fundus anomalies and abnormal EOG's en ERG's were found. Twenty-nine of these thirty workers were reexamined in 1983. A number of them were no longer exposed to CS2 for a period varying between 1 and 43 months. The fundus signs (pigmentary changes and vascular lesions) increased in frequency, even if the patient was no longer exposed. The light/dark ratio of the EOG after 4 years was decreased in comparison with the first EOG, although this was not statistically significant. The ERG improved on follow-up. This could be related either to a shift to supranormal amplitudes or to recovery from subnormal amplitudes after the patient was no longer exposed.

Carbon Disulfide↗
PubMed1982

ERG in childhood.

Explore the source record for details and available documents.

Adolescent↗
PubMed1980

Ophthalmological aspects of chronic CS2 intoxication.

As a pilot study preliminary to a large scale survey on chronic CS2 toxicity 30 workers of a viscose rayon industry in Belgium have been examined. Twenty of them were working in the xanthation spinning department where chronic CS2 intoxication is more likely to occur and ten controls were chosen form the supposedly safe bleaching division. Ophthalmological evaluation included visual fields, coulour vision testing, fluoro-angiography, ERG and EOG. In both groups fundus anomalies, abnormal EOG's and subnormal or supranormal ERG's were found. The fundus anomalies consisted either of discrete pigmentary changes in the posterior pole or microvascular retinal lesions.

Adult↗
PubMed1977

Electrophysiological studies before and after argon-laser photocoagulation in diabetic retinopathy.

50 eyes with diabetic retinopathy were studied before and after treatment with argon-laser coagulation. After treatment, decreases of the L/D ratios of the EOGs and of the amplitudes of all ERG components were found. The scotopic b waves were more involved than the photopic b waves. The peak times were hardly modified. The dark-adaptation curves were not modified. Interesting was the fact that in the pretreatment findings the EOGs were involved before the ERGs. The decreases of the L/D ratios started when avascular and ischemic zones were seen on fluorescein angiography.

Adult↗
PubMed1976

Progressive cone dystrophies.

Patients with progressive generalized cone dystrophy often present nystagmus (or strabism) and complain of photophobia, decrease in visual acuity or disturbances in colour perception. The most classic fundus abnormality is the bull's eye maculopathy or a pallor of the optic disc. Minimal macular changes are sometimes seen, which may progress to a bull's eye type of macular degeneration. The photopic ERG is always very affected, whereas at first the scotopic ERG seems normal. Progressive deterioration of the visual functions is accompanied by increasing fundus lesions and rod involvement, as suggested by the modifications of the dark adaptation curve and the scotopic ERG. However, the progression of typical generalized cone dysfunction is very slow. On the contrary, in some cases of so-called Stargardt's disease with peripheral participation, a very rapid progression has been observed. In such cases a normal ERG does not necessarily mean that the disease will remain localized to the macular area. No definite prognosis can be made on one single ERG. In 3 cases with sector pigmentary retinopathy the photopic ERG was more affected than the scotopic ERG. However, these cases are probably primary cone-rod dystrophies. Although there is no electrophysiological control, our clinical impression is that the evolution, if possible, is very slow.

Adolescent↗