Search PubMed⌕ Search

Biomedical subjects

J R Roberson

Publications and source records attributed to J R Roberson.

40 records · Page 3Linked to original sources
PubMed1985

The Mauch hydraulic knee unit for above knee amputation.

Hydraulic knee units provide a mechanical means of simulating normal gait in the above knee amputee. Sixty-one above the knee amputees were fitted with 70 Mauch SNS hydraulic knee units. Four of 60 patients rejected or were unable to use the hydraulic knee. Only one patient rejected the hydraulic knee unit for another design. Therefore, the rate of acceptance of the prosthesis was 93%. If inappropriate prescriptions for two triple amputees are omitted, the acceptance rate rises to 97%. A significant majority of patients stated that the hydraulic knee unit gave them a smoother gait, ability to change cadence, increased activity level, increased stability in stance phase, fewer falls, and less fatigue.

Adult↗
PubMed1983

The frequency and mutation rate of balanced autosomal rearrangements in man estimated from prenatal genetic studies for advanced maternal age.

The frequencies of balanced chromosome rearrangements were estimated from three series of advanced maternal-age prenatal genetic studies, and were compared to the frequencies that had been estimated from consecutive newborn surveys. In the maternal-age prenatal studies, the frequencies were: Robertsonian translocations, 0.11%; reciprocal translocations, 0.17%; and inversions, 0.12%. The total frequency of balanced rearrangements in the prenatal genetic studies performed with banding (0.40%, or 1 in 250) was twice that in the consecutive newborn surveys performed without banding (0.19%, or 1 in 526). The difference was limited to inversions and reciprocal translocations; the frequency of Robertsonian translocations was similar in the prenatal series and the newborn surveys. Both familial and de novo rearrangements were more common than anticipated. The de novo cases provided a mutation rate estimate of 4.3 per 10,000 gametes per generation (compared with 1.78 to 2.2 per 10,000 gametes in other surveys). These higher estimates may more reliably approximate the true mutation rate and frequencies of balanced rearrangements in the newborn population than do the newborn surveys.

Chromosome Aberrations↗
PubMedDate not supplied

Prenatal diagnosis of 22q11.2 deletion when ultrasound examination reveals a heart defect.

PURPOSE: The incidence of 22q11.2 deletion syndrome is approximately 1 in 5,000 births, and accounts for 5-30% of all heart defects, making it one of the more common genetic conditions in the population. METHODS: We employed fluorescence in situ hybridization (FISH) to study the incidence of 22q11.2 deletions in fetuses with cardiac anomalies detected on ultrasound examination. RESULTS: Of 64 cases, 18 had visible chromosome anomalies. FISH testing for 22q11.2 deletion was performed on the remaining 46 cases, and five exhibited a 22q11.2 deletion. Three of the five had de novo deletions, one was maternally inherited, and one family declined testing. CONCLUSION: FISH analysis for 22q11.2 deletion should be performed on all fetuses with cardiac defects (excluding hypoplastic left heart and echogenic focus) and a normal G-banded karyotype.

Chromosome Aberrations↗