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Biomedical subjects

J D Edwards

Publications and source records attributed to J D Edwards.

At least 91 records · Page 5Linked to original sources
PubMed1986

Retroperitoneal perforation of the appendix presenting as subcutaneous emphysema of the thigh.

Retroperitoneal abscesses may develop insidiously, resulting in delayed diagnosis with significant morbidity and mortality. Subcutaneous emphysema of the thigh may be a late manifestation of this process, and often heralds a poor prognosis because of associated myonecrosis and fulminant sepsis. The presentation and clinical course of such a patient is summarized, and the relevant anatomy of the retroperitoneal spaces that predisposes to this condition is described.

Abscess↗
PubMed1986

Significance and management of intractable supraventricular arrhythmias in critically ill patients.

In a heterogeneous group of 23 critically ill patients with recurrent and intractable bouts of supraventricular arrhythmia, increases in pulmonary artery wedge pressure significantly decreased cardiac output and exacerbated respiratory failure. Most patients were eventually stabilized on a long-term iv infusion of the calcium antagonist verapamil which, with appropriate monitoring, was well tolerated. We suggest that the use of verapamil infusion may play a significant role in the management of such patients and that further studies are justified.

Adolescent↗
PubMed1986

Acute polycythemia increases the disappearance rate of clottable fibrinogen in the newborn dog.

To explore the pathophysiology of the necrotizing enterocolitis caused by polycythemia in the newborn dog, the effect of acute polycythemia on fibrinogen disappearance rate was studied in 38 puppies (3-14 days). All pups received an exchange transfusion removing 65 ml/kg of blood and transfusing 85 ml/kg of either whole blood (control, resulting hematocrit = 37), or packed red blood cells (polycythemia, resulting hematocrit = 68). Necrotizing enterocolitis was found in 15 of 19 polycythemic and four of 19 control pups (p less than 0.01). 125I fibrinogen and Evan's blue (an albumin marker) were injected 2 h after transfusion and the concentration of clottable labeled fibrinogen and albumin tracer were measured at 1/2 and 2 h after injection. The fraction of the tracer that disappeared over the 1 1/2-h period was calculated. In the polycythemic group 45 +/- 18 SD% of the clottable fibrinogen disappeared versus only 28 +/- 15% in the control group (p less than 0.01). In the polycythemic group 36 +/- 21% of the albumin tracer disappeared versus 31 +/- 12% in the control group (NS). Thus polycythemia in the newborn dog is associated with an increased disappearance rate of clottable fibrinogen not associated with a general increase in protein disappearance rate. Thus an intravascular coagulopathy is evident in the polycythemic animals. Whether this coagulopathy is the cause of the necrotizing enterocolitis or is secondary to the necrotizing enterocolitis seen in this animal model cannot be determined from this experiment.

Animals↗
PubMed1984

Myocardial depression in streptococcal cellulitis.

A previously healthy woman developed streptococcal cellulitis of the leg after falling and lacerating her knee. On admission her blood pressure was unrecordable and her respiratory rate greater than 60 beats/minute. Mechanical ventilation was necessary, and plasma volume expansion was started, with little effect. Infusion of dopamine restored the blood pressure to 150/90 mm Hg, but interrupting the infusion for as little as 30 seconds resulted in profound hypotension. Insertion of a second central venous catheter allowed the dopamine to be given continuously, and the infusion was stopped successfully four days after her admission. She eventually made a complete recovery. This case highlights the need for intensive supportive treatment in many streptococcal infections and, in particular, the need for inotropic support.

Adult↗
PubMed1983

More lambs.

Explore the source record for details and available documents.

Letter↗
PubMed1983

Normal joint mobility in mitral valve prolapse.

Thirty-seven adults (19 male, 18 female) with mitral valve prolapse (MVP) were examined for evidence of joint hypermobility scored on a 0-9 scale. None of the patients had hypermobility scores exceeding 3, and comparison with 37 healthy age and sex matched controls recruited from hospital staff failed to show an increased prevalence of hypermobility in MVP. There was no evidence that the MVP syndrome is a forme fruste of a heritable disorder of connective tissue.

Adolescent↗
PubMed1983

Mitral valve prolapse: an assessment of clinical features, associated conditions and prognosis.

One hundred and eighty-two patients (100 females, 82 males) with mitral valve prolapse (MVP) confirmed by echocardiography are described. Their ages range from 12 to 87 years (mean 48 years). The symptoms of breathlessness, pain in the chest and palpitations were analysed. They were associated with left ventricular failure, co-existing ischaemic heart disease and arrhythmias in some, but in a proportion the symptoms were thought to be due to psychoneurosis. Seventy-two patients (40 per cent) were referred because of complications of MVP. In 67 patients (37 per cent) the condition was discovered by chance and in 43 patients (24 per cent) neurotic symptoms had led to referral to hospital. A systolic click was heard in 117 patients (54 per cent); 41 patients (23 per cent) had a late systolic murmur and 30 patients (16 per cent) had a pansystolic murmur. The incidence of murmurs rose with increasing age, and pansystolic murmurs were more frequent in males. Thirty-two patients (18 per cent) had neither a click nor a murmur. Twenty-four patients (13 per cent) had associated supraventricular tachycardia and 22 (12 per cent) atrial fibrillation. Twelve patients (7 per cent) had severe mitral incompetence and eight (4 per cent) developed bacterial endocarditis. Only three patients had symptoms suggesting cerebral ischaemia. Twelve patients (7 per cent) had associated aortic incompetence. Twenty-two patients had had an inguinal hernia, the incidence in males over 50 being 26 per cent. Twenty-six patients (14 per cent) had non-specific T wave changes in the electrocardiogram. Echocardiography showed that 112 patients (62 per cent) had mid-systolic buckling of the posterior leaflet and 70 patients (38 per cent) had holosystolic prolapse. In view of the high incidence of complications it is felt that the long-term prognosis not as good as has been generally believed.

Adolescent↗
PubMed1980

Effects of scopolamine, pentobarbital, and amphetamine on radial arm maze performance in the rat.

Rats were trained to obtain food pellets from the end of each arm of an eight-arm radial maze. Baseline performance was characterized by very few entries into arms from which the food pellet had already been obtained. In Experiment 1, neither d-amphetamine (0.1-3.0 mg/kg) nor pentobarbital (1.0-10.0 mg/kg) affected choice accuracy, although the rate of arm-entry increased after d-amphetamine and decreased after pentobarbital. Scopolamine (0.1-1.0 mg/kg), on the other hand, reduced both accuracy and the rate of arm entry. In a second experiment, the effects of scopoalmine were replicated using a between-subjects design. Methylscopolamine (0.17, 1.0 mg/kg) was found to have little effect on performance. Multiple response criteria were also compared in the second experiment. Scopolamine was found to affect runs farther out the arm differently than it affected abbreviated arm entrances. A post-trial feeding test was also included to evaluate changes in reinforcer effectiveness, and showed that food continued to be a reinforcer after both scopolamine and methylscopolamine.

Animals↗
PubMed1979

Effects of diazepam and ethanol alone and in combination on conditioned suppression of key-pecking in the pigeon.

Pigeons were intermittently given grain reinforcement for key pecks. Occasional 30-sec keylight changes (warning stimulus) were followed by a brief electric shock, which suppressed responding during the warning stimuli. This suppression was reduced by diazepam and ethanol, yet combinations of the two drugs did not reduce suppression (antagonistic effect). Each drug reduced responding in the absence of the warning stimulus, and combinations of the drug produced still greater reductions in this safe-period responding (synergistic effect).

Animals↗
PubMed1978

Dual actions of substance P on nociception: possible role of endogenous opioids.

Substance P produces analgesia when administered to mice in very small doses by the intraventricular route (1.25 to 5 nanograms per mouse). The analgesic effect can be blocked by naloxone. At higher doses (greater than 50 nanograms per mouse), this activity is lost. At these higher doses, however, substance P produced hyperalgesia when combined with naloxone and analgesia when combined with baclofen [beta-(4-chlorophenyl)-gamma-aminobutyric acid]. Substance P may have dual actions in brain, releasing endorphins at very low doses and directly exciting neuronal activity in nociceptive pathways at higher doses.

Animals↗
PubMed1978

Schedule-dependent effect of d-amphetamine on pausing by pigeons.

Two pigeons were exposed to a multiple schedule of grain reinforcement where key-pecks were reinforced according to a fixed ratio schedule in the presence of one stimulus and a fixed interval schedule in another stimulus. The fixed interval was adjusted to match average interreinforcer time for the fixed ratio schedule. d-Amphetamine decreased overall rate of responding in the fixed ratio schedule -- primarily by increasing pausing, especially just after a change from the fixed interval component. Rate of responding in the fixed interval schedule was increased for one bird and little affected for the other bird by d-Amphetamine. Again, changes in pausing primarily determined rate change. Since pausing was differently affected, a schedule-dependent rather than rate-dependent effect was indicated.

Animals↗