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Biomedical subjects

J Buckley

Publications and source records attributed to J Buckley.

At least 73 records · Page 4Linked to original sources
PubMed1986

Effects of norepinephrine on the dog common carotid, coronary and renal arteries: in vitro studies.

The effects of norepinephrine were studied on segments of the common carotid, left circumflex and renal arteries of dogs with the endothelium intact and removed. Norepinephrine induced a dose-dependent increase in tension in segments of the renal and carotid artery but did not produce any effect on the coronary artery. Although the absence of endothelium did not affect the magnitude of the norepinephrine-induced vasoconstriction of the renal artery, it elicited a more pronounced response in the carotid artery in which the endothelium was removed. Our data suggest that the vascular response to norepinephrine is dependent upon the specific arterial bed and, secondly, that the endothelium plays a determinant role in the magnitude of the response of the carotid artery.

Animals↗
PubMed1986

Magnetic resonance imaging and placenta previa.

Twenty-five women with diagnoses of placenta previa on ultrasound examination underwent magnetic resonance imaging examination. An assessment of placental position and the relationship of the lower placental edge to the internal os was made with both techniques and the results were compared. There was complete correlation of placental localization but significant differences were found in the determination of the degree of placenta previa. This occurred more often with posteriorly situated placentas. Magnetic resonance imaging directly affected management with regard to delivery in seven cases. Magnetic resonance imaging provides a technique capable of accurately assessing placental position and its relationship to the cervix, thereby leading to a reduction in hospitalization and inappropriate operations.

Cervix Uteri↗
PubMed1986

Magnetic resonance imaging--its application to cervical carcinoma.

Twenty-five women with primary carcinoma of the cervix were examined with magnetic resonance imaging (MRI). A number of different pulse sequences with T1 and T2 weighting were employed to determine optimum tissue contrast, and the potential for staging cervical cancer was assessed and compared with the clinical findings. MRI is seen to give a unique view of cervical cancer in particular in stage I and II disease where other imaging techniques have known limitations. In addition, stages III and IV were well seen with demonstration of tumour comparable with that of computerized axial tomography (CT).

Adenocarcinoma↗
PubMed1986

Magnetic resonance imaging and hydatidiform mole.

Five women with complete and partial hydatidiform mole were examined by magnetic resonance imaging (MRI). Spin-echo pulse sequences (T2 weighted) were found to provide excellent resolution, while inversion-recovery pulse sequences (T1 weighted) gave better pathological detail. The myometrium was clearly seen on each patient and no invasion by the tumour detected. This corresponded to the histological findings. The potential uses of magnetic resonance in the diagnosis of primary and recurrent trophoblastic disease and its role in management are discussed.

Female↗
PubMed1986

Magnetic resonance imaging and discography in the diagnosis of disc degeneration. A comparative study of 50 discs.

The lumbar spines of 22 patients were examined for disc degeneration by magnetic resonance imaging (MRI) and by discography. The results from 50 intervertebral discs visualised by both techniques were independently assessed and graded on a five-point scale from normality to gross degeneration and then compared. In 44 discs the results agreed. Of the six discs which gave differing results, four discrepancies were due to observer error and two to incorrect placement of the discographic needle. MRI was shown to be more accurate than discography in the diagnosis of disc degeneration. It has several major advantages, which should make it the investigation of choice.

Adult↗
PubMed1986

The changes in the intervertebral disc after chemonucleolysis demonstrated by magnetic resonance imaging.

Magnetic resonance imaging (MRI) of the spine produces images which reflect the chemical composition of the intervertebral disc. We have conducted a prospective study of the serial changes in the MRI appearance of the intervertebral disc after chemonucleolysis with the enzyme chymopapain. Fourteen patients were studied after single-level chemonucleolysis and the results compared with a control group of 17 discs in six patients who had diagnostic discography without enzyme insertion. A consistent pattern of gradual loss of signal from the nucleus pulposus culminating in complete loss of nuclear signal was seen in all cases after chemonucleolysis. Chymopapain therefore produced MRI changes analogous with premature gross disc degeneration. The rate at which this occurred varied; complete loss of signal took at least six weeks. Transitory minor end-plate changes were present in five patients, probably representing a mild chemical discitis. No similar changes were seen in the discography group.

Acute Disease↗
PubMed1986

Identifying a limited number of foods important in supplying selected dietary nutrients.

Three methods were developed to identify a limited number of foods that are important dietary contributors of fat, dietary fiber, and vitamins A, C, and E. In the first method, foods were ranked by the amount of each nutrient supplied per person per day and the effect each food had on the relative ranking of individuals with respect to the intake of those nutrients. Foods scoring high on both scales for a given nutrient were selected as important dietary contributors of that nutrient. In the second method, foods were selected according to the mean nutrient contribution per consumer (nonconsumers of a food were eliminated from this estimation procedure). In the third method, foods were selected that contributed a relatively large percentage of the total dietary intake of a given nutrient. The three methods were applied to data from an extensive dietary questionnaire. The authors then compared the limited lists of foods identified by each method. Generally, the methods yielded similar food lists. Regression analysis was then employed to test the ability of the selected foods to predict the nutrient totals calculated from the original, more extensive dietary questionnaire. The results suggest that a limited number of foods may have strong predictive ability, but that has not been tested in any other population.

Aged↗
PubMed1986

Pre-operative magnetic resonance imaging of stage 1 endometrial adenocarcinoma.

Twelve women with stage I endometrial adenocarcinoma were examined by magnetic resonance imaging before definitive surgery. Using this technique the depth of myometrical invasion, tumour site and cervical involvement were assessed and the results compared with the operative and pathological findings. Magnetic resonance imaging is a unique non-invasive method of assessing the early stages of endometrial adenocarcinoma before radiotherapy and surgery.

Adenocarcinoma↗
PubMed1985

A vasopressin-mediated diminution of potassium excretion in water-loaded man.

Intravenous vasopressin (1-3 mu-units min-1 kg-1) had an antidiuretic effect on water-loaded man and also diminished potassium excretion. As noted by others, aspirin (2.4 g) enhanced the antidiuretic effect of vasopressin, but the fall in potassium excretion was not modified by prior administration of aspirin, which makes it unlikely that the fall was due to the release of endogenous prostaglandins. After terminating the infusion of vasopressin, the fall in potassium output persisted longer than the antidiuresis, which makes it unlikely that the antikaliuretic effect of vasopressin is secondary to its effect on urine flow. The unchanged antikaliuretic effect of vasopressin after aspirin treatment, together with its persistence after terminating the infusion, suggest the possible existence of vasopressin-mediated potassium absorption in the distal nephron in certain circumstances. Aspirin administration had specific effects of its own in water-loaded man. It decreased both the water diuresis and sodium excretion but did not alter potassium excretion or urine osmolality.

Adult↗
PubMed1985

Correlation of chromosome abnormalities with patient characteristics, histologic subtype, and induction success in children with acute nonlymphocytic leukemia.

Cytogenetic analyses of bone marrow cells were performed in 195 children with acute nonlymphocytic leukemia (ANLL) at diagnosis, as part of Childrens Cancer Study Group Study No. 251. Ninety-six patients (49%) exhibited clonal abnormalities, including trisomy 8 in 18 patients, t(8;21) in 11, t(15;17) in seven, loss of a sex chromosome in seven, monosomy 7 in seven, and the Philadelphia chromosome in four. Clonal abnormalities were found significantly more often in younger patients. Furthermore, recurring cytogenetic abnormalities tended to correlate with specific ages. For example, t(8;21) was associated significantly with children over four years of age, while -7 associated with overall loss of genetic material from the long arm of chromosome 7 (7q) and 11q- were associated significantly with younger children. Recurring chromosome abnormalities also correlated with specific ANLL histologic subtypes, such as t(8;21) with acute myelogenous leukemia and t(15;17) with acute promyelocytic leukemia. Presence or absence of cytogenetic abnormalities was compared with the ability of patients to achieve remission. Individuals exhibiting clonal abnormalities in bone marrow cells had an equally likely chance of achieving remission (74%) as those individuals with normal karyotypes (75%). Nonrandom chromosome abnormalities associated with a high induction success rate included +8 with a 94% induction success rate (P = .13) and t(8;21) with a 91% success rate (P = .46). Patients exhibiting the -7 abnormality associated with overall loss of 7q had a significantly less successful induction outcome, with only 28% achieving remission (P = .02); three of seven patients with t(15;17) died during induction therapy.

Acute Disease↗
PubMed1985

The old and the new: a study of five contrast media for urography.

Five contrast media, Conray 280 and 420, Urografin 370, Uromiro Sodium 300 and Niopam 370, were compared in a randomised trial involving a total of 482 patients. The best urographic agent was Conray 420 and the worst Conray 280, these control agents defining the ends of the scoring system. Uromiro Sodium 300 was very nearly as good as Conray 420. A non-ionic agent, Niopam 370, scored nearly equal with Urografin 370; both were rather better than Conray 280. There was little difference in minor reactions between the media. No reason was found to prefer non-ionic to ionic agents for general use in urography; indeed for a diagnostic examination the sodium salt of an ionic agent is preferable.

Adult↗
PubMed1984

Radiotherapy of a pseudotumor in a hemophiliac with Factor VIII inhibitor.

An 11-year-old hemophiliac with a high level of Factor VIII inhibitor (50 Bethesda units) developed a pseudotumor of the mandible. Treatment with Factor IX concentrates was unsuccessful. Since surgical management was contraindicated, the patient was given 600 rad to the mandibular lesion, which resulted in complete recovery. The authors stress that radiotherapy may be successful in pseudotumor when surgery is contraindicated.

Child↗