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Biomedical subjects

G Farrell

Publications and source records attributed to G Farrell.

At least 37 records · Page 2Linked to original sources
PubMed1984

Visual evoked response changes following intrathecal injection of water-soluble contrast media: a possible method of assessing neurotoxicity and a comparison of metrizamide and iopamidol.

An investigation was carried out to ascertain if there was a change in visual evoked responses following the intrathecal injection of water-soluble contrast media for myeloradiculography and if this change provided an indication of neurotoxicity as assessed by the onset of headache during a period of 20 h following the radiological examination. The patients were unselected and examined, when facilities for measuring the visual evoked response were available, immediately before and at 1 and 20 h after the examination. Control readings were carried out before, 1 h and 20 h after lumbar puncture in patients who did not have an injection of contrast medium. The first 25 patients in the series received metrizamide; when iopamidol became available a change to the newer medium was made and iopamidol was used on all subsequent patients. All the injections were carried out by the same radiologist and the patients were kept in hospital overnight and interviewed the next morning, avoiding a specific reference to headache unless the patient denied all symptoms. It was found that the latency of the visual evoked response was affected in some cases by the presence of contrast medium in the cerebrospinal fluid and that there was a correlation between the severity of headaches and the delay in the visual evoked response at the 20 h post-myelogram measurement, but not at 1 h after the examination. It would appear, therefore, that the visual evoked response measurement is a valid method of assessing, in the short term, the neurotoxicity of intrathecal water-soluble contrast media and that, on this evidence, iopamidol is less neurotoxic than metrizamide. We are not aware of any long-term complications resulting from the use of either contrast medium.

Contrast Media↗
PubMed1983

[5 years' experience with revascularization of the corpus cavernosum by a new microsurgical technic in the treatment of vascular sexual impotence].

Treatment of 138 patients with sexual impotence of vascular origin involved revascularization of the dorsal and/or cavernous arteries of the penis by means of a venous auto or homograft branched on the external iliac or femoral arteries. Arteries requiring revascularization can be clearly detected by peroperative arteriography. Two or three shunts are usually necessary. The branches of the venous graft are firstly anastomosed microsurgically (under a 25 to 30 magnification) to the dorsal and/or cavernous arteries of the penis after their microsurgical dissection. The origin of the graft is then joined to the femoral or terminal iliac arteries. Results were generally excellent and there were very few complications: thrombosis during the first 30 postoperative days in 9 cases, hemorrhage in only one case during the last 3 years, frequent but rapidly regressing edema of the foreskin, and obturation of the shunt after the first month (between the 6th and 32nd months) in 4 patients. Postoperative priapism was never noted. This technique, in contrast to that employing direct implantation of the epigastric arteries into the corpus cavernosum, ensures the return of normal physiological erections. Follow-up after a minimum of 6 months showed that recovery was total in 78.6%, the condition being made worse in only 8.8%.

Angiography↗
PubMed1979

Symptomatic lower esophageal ring: treatment of 24 patients.

The lower esophageal ring, or Schatzki's ring, consists of a thin, submucosal, circumferential scar which forms a thin incomplete diaphragm in the lower esophageal lumen. The symptoms may be either episodic aphagia or progressive dysphagia, and the severity of symptoms is related to the diameter of the ring. Between 1970 and 1978, we saw 24 patients with lower esophageal rings and complaints of episodic aphagia or progressive dysphagia. Symptoms of esophagitis were present in 20 of the 24. Twenty were treated surgically by interrupting the rings and repairing the sliding hiatal hernias. Two were treated by dilatation and two received no treatment to the ring. Hiatal hernias have recurred in two patients. In one, there is a recurrent ring and in the other, an acid peptic stricture. The ring has responded to dilatation and the peptic stricture to dilatation and repair of the recurrent hernia. Two patients without symptoms of esophagitis, treated by dilatation, are doing well but the follow-up period is so far too short to draw any conclusion.

Aged↗
PubMed1978

Response bias in category and magnitude estimation of difference and similarity for loudness and pitch.

Interval scales of sensory magnitude were derived from magnitude and category estimates of loudness differences, loudness similarities, pitch differences, and pitch similarities. In each of the four loudness experiments, a loudness scale was constructed from a nonmetric analysis of the rank order of the judgments. The four loudness scales so constructed were found to be equivalent to one another and indicated that loudness was a power function of sound pressure with an exponent of .29. A similar analysis for the four pitch experiments found the pitch scales derived in each case to be equivalent to one another and linear with the mel scale of pitch. Thus the same sensory and similarities for two distinct perceptual continua. For both pitch and loudness, these sensory scales were used to generate scales of sensory differences. A comparison of the category and magnitude estimates of sensory differences with the scale of sensory differences derived from the nonmetric analyses indicated the presence of significant response biases in both category and magnitude estimation procedures.

Acoustic Stimulation↗
PubMed1971

Metabolic disease in mental retardation: a study in Texas.

Reported are the results of a study of patients admitted to the State Schools for the Mentally Retarded in Texas, over a two-year period from 1968-1970. Of 2029 cases, 185 were found on a detection battery screening to have possible metabolic disease. The report summarizes the findings on 93 cases studied in the metabolic ward at the Texas Research Institute.

Female↗