Biomedical subjects
Publications and source records attributed to J J Engelen.
We report a mentally retarded girl with minimal dysmorphic signs. Cytogenetic examination showed an interstitial deletion of chromosome 8: 46, XX, del(8)(p21.2p22). This deletion has not been reported before. We compare the patient with the literature data.
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We report on 2 girls with mosaic tetrasomy 8p. Patient 1 showed the extra iso 8p chromosome in 20% of cultured lymphocytes and 18% of cultured fibroblasts [46,XX/47,XX,+i(8p)]. She presented with growth retardation, mild facial alterations, and motor developmental delay. Patient 2 presented with developmental delay, hypotonia, and slight facial alterations; she had the extra iso 8p chromosome in 94% of cultured peripheral lymphocytes. The patients are compared to the 6 previously reported cases. In our experience, the presently reported patients clinically resemble children with inv dup(8)(p21-p22) and patients with mosaic trisomy 8.
The vast majority of individuals with the fragile X syndrome show expanded stretches of CGG repeats in the 5' non-coding region of FMR1. This expansion coincides with abnormal methylation patterns in that area resulting in the silencing of the FMR1 gene. Evidence is accumulating that this directly causes the fragile X phenotype. Very few other mutations in FMR1, causing the fragile X phenotype have been reported thus far and all concerned isolated cases. We, however, report a family, in which 11 individuals have a deletion of 1.6 kb proximal to the CGG repeat of the FMR1 gene. Although fragile X chromosomes were not detected, all 4 affected males and 2 of the carrier females show characteristics of the fragile X phenotype. Using RT-PCR we could demonstrate that FMR1 is not expressed in the affected males, strongly suggesting that the FMR1 promoter sequences 5' to the CGG repeat are missing. The deletion patients have approximately 45 CGG repeats in their FMR1 gene, though not interspersed by AGG triplets that are usually present in both normal and expanded repeats. It is hypothesized that prior to the occurrence of the deletion, an expansion of the repeat occurred, and that the deletion removed the 5' part of the CGG repeat containing the AGG triplets. Transmission of the deletion through the family could be traced back to the deceased grandfather of the affected males, which supports the hypothesis that the FMR1 gene product is not required for spermatogenesis. Finally, the data provide additional evidence that the fragile X syndrome is a single gene disorder.
Fluorescent in situ hybridization with probes specific for a chromosomal subregion and chromosome-specific libraries (chromosome painting) are important new methods for assessing chromosome rearrangements. In this paper we present four patients with additional chromosomal material on chromosome 8p who have been studied using G-banding techniques, chromosome painting and FISH with cosmid probes specific for the region 8p23.1-->8pter. In all cases we found a partial inversion duplication of 8p along with a deletion of the region 8p23.1-->8pter.
We report one patient with a de novo inversion duplication 18 (pter-->cen) and two cases of direct tandem duplication 18 (pter-->cen), one due to maternal inheritance and the other arising as mosaicism of unknown origin. The duplications are demonstrated by high resolution banding. They were verified by in situ hybridization with a paint specific for chromosome 18 and with DNA probe LI.84 specific for the centromere region of chromosome 18. FISH with the genomic DNA probe pHRR68 specific for 18p11.32 revealed a subtle deletion concomitantly involved in the case of inversion duplication 18p. The patients exhibit slight developmental delay/moderate mental retardation and only a few dysmorphic features. The literature on trisomy 18p is reviewed and the present cases are compared to it.
We report on a girl with a terminal deletion (46,XX,del(4)(q33-->ter). She presented with developmental delay and slight facial dysmorphism. The clinical features are compared with the patients in the literature and a review of the psychologic data is given.
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The pneumoconioses are associated with chronic inflammatory processes during which increased amounts of reactive oxygen species are formed in the lower respiratory tract. To characterize the effect(s) of these processes on the defense system against free radicals, we studied 91 individuals with long-term occupational exposure to coal mine dust. Thirty-one subjects were classified with radiological evidence to be pneumoconiotics, while 58 control miners had no pulmonary disorders. We measured antioxidant parameters in red blood cells, considering the latter to reflect the oxidative stress in the lung. Glutathione levels were significantly decreased (p = 0.04) in red blood cells of miners with coal workers' pneumoconiosis with radiograph classification 0/1 to 2/1, while in miners with classification 3/2 to 3/3, the plasma iron concentrations were significantly decreased (p = 0.04). Moreover, some factors of the anti-oxidant system (superoxide dismutase, catalase, glutathione peroxidase) were correlated in the diseased but not in the control miners. Taken together, all data support the role of the erythrocyte as a circulating anti-oxidant carrier and also that changes in red blood cell anti-oxidant factors reflect the oxidative stress imposed by the pneumoconiotic (inflammatory) processes in the lung.
It is generally accepted that fibrotic lung diseases are mediated by macrophage-derived cytokines. We investigated the release of the monokine tumor necrosis factor-alpha (TNF) from blood monocytes in a group of 66 coal miners and 12 non-dust-exposed individuals. Twenty-seven miners had simple Coal Workers' Pneumoconiosis (CWP). Control miners (n = 39) were matched with respect to age, years underground, and smoking. Monocytes were assayed for TNF release, spontaneously or in response to soluble (endotoxin) or particulate (coal mine dust, silica) stimulation. TNF was measured with a TNF-specific ELISA. Monocytes of all subjects responded to stimulants by the release of TNF. Dust-exposed controls' monocytes revealed higher TNF release as compared to normal controls. The greatest discriminator between control miners and cases (CWP) was coal mine dust-induced TNF release. Interestingly, the largest difference was observed between controls and those cases with a small number of opacities (0/1, 1/0, 1/1, and 1/2), giving an odds ratio of 6.3 to find an individual with a "high" dust-induced TNF release in the patient group.
Health surveillance of workers exposed to fibrogenic agents ideally should identify individuals at risk or detect pulmonary fibrosis in preclinical stages. We investigated serum procollagen type III N-terminal peptide (PIIIP) in several groups of active miners and in a nondust-exposed control group. The purpose of this study was to determine the applicability of PIIIP as an early noninvasive marker of pulmonary fibrosis in workers exposed to coal mine dust. PIIIP levels were significantly elevated in miners without radiological signs of coal workers pneumoconiosis (CWP) as compared with the nonexposed controls. However, in coal miners with CWP beyond ILO classification 1/0, PIIIP levels were not significantly different from nondust-exposed controls. Trend analysis within the miners group indicated a decrease in PIIIP levels with progression of the fibrosis. Our data suggest that detection of early lung fibrosis by measuring serum PIIIP values may be more sensitive than radiological diagnosis of CWP. However, follow-up of the control miners with respect to serum PIIIP and chest radiography is essential to validate PIIIP as a biological marker for CWP.