Complex genetic counselling and prenatal analysis in a woman with external ophthalmoplegia and deleted mtDNA.

Single large mitochondrial DNA deletions (DeltamtDNA) are usually spontaneously occurring and cause a wide variety of symptoms, ranging from severe infantile multisystem disorders to adult onset progressive external ophthalmoplegia (PEO). There is always heteroplasmy with a mixture of normal and mutant mtDNA and the levels usually vary widely between tissues. There is at present insufficient scientific basis for accurate genetic counselling of women with DeltamtDNA, but it is reasonable to assume that DeltamtDNA can be transmitted if it is present in the female germ cells.

An ethnographic study of differentiated practice in an operating room.

An ethnographic study was conducted to investigate implementation of the clinical nurse III or team leader (TL) role as part of a newly executed nursing differentiated practice model. The six TLs studied were employed in the operating room (OR). Through participant observation, interviews, and document analysis, the TL role--as well as perceptions of the role by the TLs and OR staff--were studied.

Mitochondrial medicine--recent advances.

Mitochondria contain the respiratory chain enzyme complexes that carry out oxidative phosphorylation and produce the main part of cellular energy in the form of ATP. Mitochondrial DNA (mtDNA) encodes essential subunits of the respiratory chain and is thus critical for maintaining cellular energy production. The first pathogenic mtDNA mutations were reported in 1988, and today more than 50 disease-causing mtDNA mutations have been identified.

Developing quality measures for adolescent care: validity of adolescents' self-reported receipt of preventive services.

Objective: To demonstrate the feasibility of directly surveying adolescents about the content of preventive health services they have received and to assess the validity of adolescent self-reported recall.

Data Sources/setting: Audiotaped encounters, telephone interviews, and chart reviews with 14-21 year olds being seen for preventive care visits at 15 pediatric and family medicine private practices, teaching hospital clinics, and health centers.

Design: 537 adolescents presenting for well visits were approached, 400 (75 percent) consented, 374 (94 percent) were audiotaped, and 354 (89 percent) completed telephone interviews either two to four weeks or five to seven months after their visits.

Failure to achieve gene conversion with chimeric circular oligonucleotides: potentially misleading PCR artifacts observed.

Recently, a novel strategy for nucleotide exchange of target DNA using chimeric RNA/DNA oligonucleotides (CO) was reported. The CO can easily be transfected into cells, remain stable within the cells, and migrate to the nucleus. We have in this study used 42 similar constructs for targeting six different human and canine loci.

Dilated cardiomyopathy and atrioventricular conduction blocks induced by heart-specific inactivation of mitochondrial DNA gene expression.

Mutations of mitochondrial DNA (mtDNA) cause several well-recognized human genetic syndromes with deficient oxidative phosphorylation and may also have a role in ageing and acquired diseases of old age. We report here that hallmarks of mtDNA mutation disorders can be reproduced in the mouse using a conditional mutation strategy to manipulate the expression of the gene encoding mitochondrial transcription factor A (Tfam, previously named mtTFA), which regulates transcription and replication of mtDNA. Using a loxP-flanked Tfam allele (TfamloxP) in combination with a cre-recombinase transgene under control of the muscle creatinine kinase promoter, we have disrupted Tfam in heart and muscle.

Refined genetic localization of the Best disease gene in 11q13 and physical mapping of linked markers on radiation hybrids.

Best's macular dystrophy, also known as vitelliform macular degeneration type 2 (VMD-2), is an autosomal dominant eye disorder that causes reduced visual acuity. It generally manifests itself in the teenage years. The gene mutated in VMD-2 patients may provide valuable insight into the biological mechanisms of the far more common disorder age-related macular degeneration.

Fine mapping of the gene for autosomal dominant juvenile-onset glaucoma with iridogoniodysgenesis in 6p25-tel.

Glaucoma is a group of ocular disorders leading to reduced visual capabilities and sometimes blindness. The biochemical defect is unknown but it is shown that reduced drainage of the aqueous humour from the anterior chamber may lead to increased intraocular pressure and gradual atrophy of the optic neurons. Families with various forms of autosomal dominant (AD) glaucoma have been linked to 1q21-31, 2cen-q13, 4q25-27, and 13q14 and autosomal recessive congenital glaucoma have been localized to chromosome 1p36 and 2p21.

Genetic mapping using fluorescent quantification of allele frequencies in pooled DNA loaded by solid support.

An efficient and labour-saving method for fragment analysis in linkage studies using biotinylated primers and streptavidin-coated combs is presented. The level of streptavidin attached to the combs was used to control the amount of immobilised material. Thus, the need for titration of PCR products to fit the dynamic range of the sequencer was reduced.

Glutamate participates in the peripheral modulation of thermal hyperalgesia in rats.

While the effects of excitatory amino acids have been well characterized in the central nervous system, relatively little is known about their possible modulation of elements responsible for hyperalgesia within peripheral tissue. The presented experiments demonstrate that the intraplantar (i.pl.

Confirmation of linkage to 1q21-31 in a Danish autosomal dominant juvenile-onset glaucoma family and evidence of genetic heterogeneity.

Autosomal dominant juvenile-onset open-angle glaucoma has been mapped to 1q21-31 in a number of American families. Our study confirms linkage in a Danish five-generation dominant juvenile-onset glaucoma family with a maximum two-point lod score of 6.67 at the D1S210 locus.

Fine mapping of Best's macular dystrophy localizes the gene in close proximity to but distinct from the D11S480/ROM1 loci.

The Best's macular dystrophy (BMD) gene has previously been mapped to the 11q13 region. In this study, recombination data localizes the BMD gene to the 6-cM genetic interval between the markers Fc epsilon RI and D11S480/ROM1 in a large Swedish 12-generation BMD family. Mutation analyses of the candidate gene ROM1 did not reveal any mutations that could explain the disease phenotype.

The gene for Best's macular dystrophy is located at 11q13 in a Swedish family.

A large Swedish family with more than 250 cases of Best's macular dystrophy has been clinically and genetically studied. The gene was traced to a couple born in central Sweden in the 17th century. Highly significant evidence for genetic linkage to DNA markers on chromosome 11q13 was detected.

Recording electrophysiological signals from small moving animals: electrode fixation and low torque swivel for recording a weakly electric fish in a group.

A silicone rubber ring maintains an electrode on the electric organ of a mormyrid fish. The electrode is connected with a novel swivel, which allows free motion of the wire around its axis. The principle of the rotating contact is based on magnetic contact between a steel pin (moving) and a steel ball (fixed).