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Biomedical subjects

T Rosenberg

Publications and source records attributed to T Rosenberg.

At least 19 recordsLinked to original sources
PubMed1995

[Molecular genetics of red-green color blindness].

Normal colour vision is trichromatic and is mediated by the blue, green and red visual pigments present in the corresponding blue, green, and red cone cells of the retina. The red and green pigment genes have evolved from an ancestral pigment gene and reside in a head-to-tail tandem array on the long arm of the X chromosome. This arrangement and a high degree of homology predispose to illegitimate recombination between the red and green pigment genes explaining the various forms and the high frequency of red-green colour vision defects.

Color Vision Defects↗
PubMed1995

[Molecular genetic examination in sex-linked color blindness].

The molecular structure of the X-linked colour-vision locus was studied in a family where mild red-green colour-vision deficiency (deuteranomaly) segregated, and in a male with complete absence of red and green colour-vision (blue cone monochromasy). In individuals with normal colour-vision the red and green pigment genes had normal molecular structure whereas individuals with deuteranomaly, in addition to normal red and green genes, also had an abnormal hybrid gene consisting of parts of the green and red pigment genes. The individual with blue cone monocromasy had only a red-green hybrid gene inactivated by a critical mutation in codon 203. Thus, the phenotypes predicted from the individual genotypes were in complete accord with the observed phenotypes.

Adult↗
PubMed1995

[Hereditary optic nerve atrophy. A clinical-genealogical status over Danish families with Leber disease].

An update on Leber's hereditary optic neuropathy (LHON) in Denmark disclosed 32 families with at least one live affected member, or recent disease onset (Table 1). Mitochondrial DNA analysis in the 30 families available for blood sampling identified the pathogenic mutation in all of them: ND4/11778 (26 families), ND1/3460 (three families), and ND6/14484 (one family). A previous distinct male dominance (sex ratio 4.6:1 in 157 ND4-patients with onset before 1968) seems to level (sex ratio 2.6:1 in 69 ND4-patients with onset in 1968 or later). Among possible explanations, we discuss improved diagnostic abilities and possible changes in women's alcohol consumption and smoking habits.

Adolescent↗
PubMed1995

Assignment of congenital cataract Volkmann type (CCV) to chromosome 1p36.

Congenital cataract, type Volkmann (McKusick no 115665, gene symbol CCV) is an autosomal dominant eye disease. The disease is characterized by a progressive, central and zonular cataract, with opacities both in the embryonic, fetal and juvenile nucleus and around the anterior and posterior Y-suture. We examined blood samples from 91 members of a Danish pedigree comprising 426 members, by using highly informative short tandem repeat polymorphisms and found the closest linkage of the disease gene (CCV) to a (CA)n dinucleotide repeat polymorphism at locus D1S243 (Zmax = 14.04 at theta M = 0.025 theta F = 0.000), at a penetrance of 0.90. Using two additional chromosome 1 markers, we were able to map the CCV gene in the sequence 1pter-(CCV, D1S243)-D1S468-D1S214. The (enolase 1) gene has been mapped to this area; however, a mutation described in this gene did not give eye disease.

Cataract↗
PubMed1995

Leber's hereditary optic neuropathy: implications of the sex ratio for linkage studies in families with the 3460 ND1 mutation.

Leber's hereditary optic neuropathy (LHON), which is associated with mutations in mitochondrial DNA (mtDNA), is commoner in males than females. A study of over 30 LHON families with a mutation at position 3460 of mtDNA demonstrates a significantly decreased male excess from that generally quoted, with evidence for a marked bias in the ascertainment of males over females. This has implications for the analysis of those factors which give rise to the male bias.

Adult↗
PubMed1995

Laboratory measurements of the transport of radon gas through concrete samples.

Experiments were conducted to measure the transportability of radon gas through common concrete samples which were characterized by their mix proportions, dimensions, porosity, air permeability, and radon gas diffusion coefficient. Several innovative test systems and methods were designed, fabricated, and calibrated to accurately measure these radon gas transport characteristics for concrete and to overcome many of the shortcomings of previously published experimental works. From the experimental results, it was found that diffusion is the dominant transport mechanism by which radon gas moves through an intact concrete slab. It was also shown that indoor radon entry rates can be greatly affected by the type of concrete mix employed. The results of this study can be utilized to improve the present technology of radon-resistant construction techniques for new residential construction.

Air Pollution, Indoor↗
PubMed1995

Leber's hereditary optic neuropathy associated with a disorder indistinguishable from multiple sclerosis in a male harbouring the mitochondrial DNA 11778 mutation.

This report describes a multiple sclerosis (MS)-like disorder in a male patient with Leber's hereditary optic neuropathy (LHON) harbouring the mitochondrial DNA 11778 base pair mutation. Given the population frequencies of MS and LHON, coincidental occurrence is unlikely. Hypothetically the mitochondrial mutation underlying LHON may contribute to presumably immunologically mediated involvement of other myelinated axons in the central nervous system in susceptible individuals, producing a disorder indistinguishable from MS. We recommend that investigation for oligoclonal bands in CSF, evoked potentials and MR brain scan in these patients be supplemented with mitochondrial DNA analysis.

Adult↗
PubMed1995

Clinical pathology and retinal vascular structure in the Bardet-Biedl syndrome.

A comparative study of clinical pathology and retinal vascular structure is described as studied by vascular casting in an eye of a patient with the Bardet-Biedl syndrome. At the time of examination the eye had been almost blind for at least 4 years. The histopathological examination showed a largely uniform loss of the outer retinal layers. The gross pathological examination of the cast ocular fundus showed three distinct zones, an inner zone inside the temporal vascular arcades where retinal vessels had been cast, a mid peripheral zone with bone spicules, and a peripheral zone with neither cast vessels nor bone spicules. The findings are discussed in relation to possible pathophysiological mechanisms involved in the development of retinal dystrophy in the Bardet-Biedl syndrome.

Female↗
PubMed1994

[Retinopathy of prematurity in Denmark 1974-1991. Analysis of the data from the Danish Registry of Diseases].

This study deals with registered Danish children with visual handicap due to retinopathy of prematurity (ROP) born between 1974 and 1991. There are 141 such children, corresponding to a frequency of 13.1 per 100.000 liveborn. The data was analysed for trends in time by chronologically subdividing the material into thirds, each group comprising 47 subjects. Birth weight and gestational age showed a decline over the period, median values in the three groups in chronological order being respectively 1.250 g, 1.100 g, and 960 g and 30, 28, and 27 weeks. Associated CNS handicaps were recorded in 17, 38, and 34%. Visual impairment was severe in all groups, the median corrected acuity of the better eye being below 1/60. Geographically there was a significant shift from an even distribution nationwide towards there being a preponderance of severe ROP cases in the Copenhagen area.

Denmark↗
PubMed1994

Mapping of the choroideremia-like (CHML) gene at 1q42-qter and mutation analysis in patients with Usher syndrome type II.

The human choroideremia-like (CHML) gene and a locus for Usher syndrome type 2 (USH2) were recently mapped to the 1q31-qter region employing physical mapping and genetic linkage studies, respectively. Using a human-rodent hybrid cell line, we could refine the assignment of CHML in this study to 1q42-qter. USH2 was shown to map to the same chromosomal segment as evidenced by the fact that D1S58, a polymorphic marker previously shown to be located proximal to the USH2 locus, was also assigned in the 1q42-qter segment. To investigate a possible role of the CHML gene in the pathogenesis of USH2, we investigated 10 Dutch and 9 Danish USH2 patients for point mutations in the open reading frame of the CHML gene. Employing polymerase chain reaction-single-strand conformation polymorphism analysis and direct sequencing, we found no disease-specific mutations. These results suggest that CHML is not involved in the pathogenesis of USH2.

Animals↗
PubMed1994

Heterozygous missense mutation in the rod cGMP phosphodiesterase beta-subunit gene in autosomal dominant stationary night blindness.

The locus for autosomal dominant congenital stationary night blindness (adCSNB) has recently been assigned to distal chromosome 4p by linkage analysis in a large Danish family. Within the candidate gene encoding the beta-subunit of rod photoreceptor cGMP-specific phosphodiesterase (beta PDE), we have identified a heterozygous C to A transversion in exon 4, predicting a His258Asp change in the polypeptide. We found a perfect cosegregation (Zmax = 22.6 at theta = 0.00) of this mutation with the disease phenotype suggesting that this missense mutation is responsible for the disease in this pedigree. Homozygous nonsense mutations in the beta PDE gene have been found recently in patients with autosomal recessive retinitis pigmentosa, a common hereditary photoreceptor dystrophy.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1994

Evaluation of waste anesthetic gases, monitoring strategies, and correlations between nitrous oxide levels and health symptoms.

The release of waste anesthetic gases (WAG) in hospital operating rooms (ORs) was evaluated to determine if staff exposure to nitrous oxide exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) and investigate possible correlations between symptoms and nitrous oxide exposure. The monitoring strategy consisted of nitrous oxide measurements by personal monitoring of the anesthetists and scrub nurses, and area monitoring at the exhaust grills. In addition, room ventilation rates and carbon dioxide concentrations were measured. Self-administered questionnaires were given to both the operating room personnel and staff on control wards. Nitrous oxide levels exceeded the current TLV of 50 ppm in 4 of 12 ORs. Anesthetists typically received the highest nitrous oxide exposure. There was a strong correlation (r2 = 0.90) for nitrous oxide dosimetry results between anesthetists and scrub nurses, and a fair correlation (r2 = 0.35) between area monitoring results and the anesthetists' personal exposures. Carbon dioxide levels commonly exceeded 1000 ppm on control wards. A correlation between reported symptoms and nitrous oxide exposure was not demonstrated. Reported symptoms more closely correlated with carbon dioxide levels. Nitrous oxide dosimetry of the anesthetists appears to be the only accurate strategy for monitoring human exposure to WAG in an operating room.

Air Pollutants, Occupational↗
PubMed1994

Gene for autosomal dominant congenital stationary night blindness maps to the same region as the gene for the beta-subunit of the rod photoreceptor cGMP phosphodiesterase (PDEB) in chromosome 4p16.3.

We studied a large multigeneration Danish family with autosomal dominant congenital stationary night blindness. Both electrophysiological and psychophysical findings in affected family members were identical to those reported in patients from the 'Nougaret family'. The disease locus in the Danish family has now been mapped by demonstrating close linkage without recombination (Q = 0.00 at Zmax = 14.4) to the locus for alpha-L-iduronidase assigned to chromosome 4p16.3. Interestingly the gene for the beta-subunit of the rod photoreceptor cGMP-specific phosphodiesterase maps to the very same chromosomal region.

Chromosome Mapping↗
PubMed1994

Dominant optic atrophy (OPA1) mapped to chromosome 3q region. I. Linkage analysis.

Dominant optic atrophy, type Kjer (McKusick no. 165500) is an autosomal dominant eye disease. The disease is characterized by moderate to severe visual impairment with an insidious onset during the first decade of life, blue-yellow dyschromatopsia and centrocecal scotoma of varying density. We examined three extended Danish pedigrees using highly informative short tandem repeat polymorphisms and found linkage of the disease gene (OPA1) to a (CA)n dinucleotide repeat polymorphism at locus D3S1314 (Zmax = 10.34 at theta M = F = 0.075). Using two additional chromosome 3 markers we were able to map the OPA1 gene in the region between D3S1314 and D3S1265 (3q28-qter).

Chromosome Mapping↗
PubMed1994

Age differences of visual field impairment and mutation spectrum in Danish choroideremia patients.

Visual prognosis is a crucial theme in the counselling of individuals affected by a progressive retinal dystrophy. Unfortunately prognostic predictions are hampered by large interindividual differences in disease courses even within well defined nosological entities. Ten patients from 8 families affected by choroideremia were studied. The clinical signs in our patients were rather uniform. Deterioration of the peripheral visual fields typically began in the second decade of life, and progressed during the following one or two decades. Esterman transformation of peripheral visual field measurements was chosen as the best single indicator of visual impairment. Noticeable age differences in residual visual fields among patients were demonstrated. The age difference between the mildest and the severest cases amounted to 25 years. One of the expectations of the exploration of disease genes, is the potential predictive value of mutation identification with regard to phenotypic variability. Different presumed causative mutations were identified. Nevertheless, all the mutations are predicted to cause premature stops during translation, resulting in a non-functional or missing protein. Consequently, the observed age variation in the photopic visual field degradation must be due to still unrecognized factors, either constitutional and/or environmental.

Adolescent↗