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Biomedical subjects

R J Gardner

Publications and source records attributed to R J Gardner.

At least 109 records · Page 6Linked to original sources
PubMed1982

Short-term inhalation toxicity of perfluoroisobutylene.

Perfluoroisobutylene (PFIB) is a highly toxic, colorless gas. The 4-hour Approximate Lethal Concentration in male rats is 0.5 ppm (v/v). The median lethal concentration (LC50) was calculated for groups of 10 male Crl:CD rats, exposed, nose-only, for either 0.25, 0.50, 1, 2, 5, or 10 minutes to various concentrations of PFIB. Atmospheric concentrations of PFIB were determined by gas chromatography (electron capture detector). No mortalities or signs of respiratory irritation were seen during exposure. Weight loss and respiratory impairment were evident up to 48 hours post-exposure. Affected rats either died with gross pathological signs of pulmonary congestion or recovered with no apparent residual effects. The 0.25-minute LC50 was 361 ppm (321--415 ppm, 95% Confidence Limits); the 10-minute LC50 was 17 ppm (15--19 ppm, 95% Confidence Limits). The steep slope of the concentration-mortality curve at each time interval reflected the narrow range of concentrations that produced mortality (LC1-LC99). In addition, a "Concentration x Time = Constant" relationship was apparent from 0.25 to 10 minutes.

Animals↗
PubMed1980

A ring 15 chromosome in a girl with minor abnormalities.

A 13 year old girl with a ring 15 chromosome is described. The only major clinical abnormalities were shortness of stature and mental dullness. The usefulness of a chromosomal investigation in patients who have relatively minor mental and/or physical defects is emphasised.

Adolescent↗
PubMed1980

Dic(21;21) in a Down's syndrome child with an unusual chromosome 9 variant in the mother.

A child with characteristic clinical features of Down's syndrome and raised red cell SOD-1 activity was found to have, in addition to a single chromosome 21, a reverse dicentric tandem translocation of two No 21s with dual NORs and C band regions. The breakpoints on the chromosomes involved in the translocation were at the most distal end of the long arms (21q223). The phenotypically normal mother carried a rare variant of a chromosome 9.

Adult↗
PubMed1980

A further report on a kindred with cases of 4p trisomy and monosomy.

An extended study on a previously described family, in which a rcp(4;12) (p14;p13) translocation is segregating, is reported. 2 further individuals with 4p trisomy are described. The risk to translocation carriers of having liveborn offspring with either 4p trisomy or monosomy is calculated to be 25%.

Adult↗
PubMed1979

Upper limb ischemia resulting from arterial thromboembolism.

Acute ischemia of the upper limb is commonly caused by trauma and embolic arterial occlusion. However, primary atherosclerotic thrombosis is found infrequently and concern regarding its incidence, recognition, and treatment prompted a review of our clinical experience. Of 36 patients with acute ischemia of the upper limb, 17 (47.2 per cent) had embolic occlusion, 9 (25 per cent) iatrogenic thrombosis in the brachial artery, and 10 (27.8 per cent) primary arterial thrombosis. Of the total group, noncardiac arterial emboli (two patients) and primary atherosclerotic thrombosis (six patients) accounted for 8 of 36 (22.2 per cent) ischemic limbs. Including 2 additional patients who had atherosclerotic thrombosis associated with trauma, the total number represented 10 of 36 (27.8 per cent). An aggressive approach to the undiagnosed patient with acute ischemia of the upper limb is warranted, including the use of arteriography in most cases. In patients with iatrogenic thrombosis in the brachial artery, we believe that the routine use of intraoperative arteriograms may improve the operative results.

Adolescent↗
PubMed1977

Surgical repair of gastroesophageal reflux with sliding hiatal hernia.

A controlled prospective study of forty-two patients shows it is feasible to correct gastroesophageal reflux complicating sliding hiatal hernia by modifying Allison's repair, using the technic of vertical mattress sutures and Dacron pledgets to approximate the crura and reattach the esophagus to the narrowed hiatus. There was no operative mortality and minimal morbidity. The follow-up period ranges from six to eighty-two months (mean, 38.5 months). One recurrence was noted clinically and verified by esophagogram, esophagoscopy, and motility studies. The remainder have no symptoms of gastroesophageal reflux, and no recurrence has been seen on repeat esophagograms.

Adult↗
PubMed1977

A new estimate of the achondroplasia mutation rate.

An estimate is derived of the mutation of achondroplasia based upon the accumulated data of recent newborn studies in four cities. In a total of 242,257 births, seven infants had mutant achondroplasia, the diagnosis being confirmed radiologically in all but one. From this, the rate of mutation of the normal to the achondroplasia allele is calculated to be 1.4 x 10(-5) +/- standard error 0.5 x 10(-5). Certain shortcomings of this estimate are discussed.

Achondroplasia↗
PubMed1977

The current status of chemodectomas.

An analysis of the current status of chemodectomas including the report of two additional cases is presented. One patient with a rare malignant intrathoracic tumor failed to survive palliative pneumonectomy. To our knowledge, this represents the seventeenth histologically proved case. The other patient had the more common carotid body tumor which was managed satisfactorily by subadventitial carotid excision. Comments are made regarding the clinical recognition and treatment of chemodectomas in general. Historical, anatomic, physiologic, and pathologic features are emphasized.

Adult↗