PubMed Health⌕ Search

Biomedical subjects

S Burke

Publications and source records attributed to S Burke.

At least 19 recordsLinked to original sources
PubMed1991

Endoscopic band ligation for treatment of non-variceal upper gastrointestinal bleeding.

An endoscopic band ligation method was successful in achieving hemostasis in two patients who had severe coagulopathy and profuse gastrointestinal bleeding from a visible vessel in the stomach. Bleeding was not controlled by multiple epinephrine injections or BICAP electrocoagulation. The technique of band ligation was easy to perform and may provide an alternative treatment for non-variceal upper gastrointestinal bleeding in selected cases.

Aged↗
PubMed1991

Importance of central noradrenergic and serotonergic pathways in the cardiovascular actions of rilmenidine and clonidine.

We examined the role of central monoamine neurotransmitters noradrenaline and serotonin in the cardiovascular actions of the alpha 2-adrenoceptor agonist rilmenidine in the conscious rabbit and compared it to clonidine. Rilmenidine and clonidine were equieffective in producing a maximum 24% reduction in blood pressure and heart rate when given intracisternally (i.c.), but rilmenidine was approximately 20-30 times less potent than clonidine. The effective i.c. doses of both drugs were 25-30 times lower than those required peripherally (i.v.). Comparison of the time course of an equieffective dose of rilmenidine and clonidine showed that the time to reach maximum effect was 10 min for both drugs but time to recovery was greater for rilmenidine (2.5-3 h vs. 1.5 h for clonidine). Destruction of central noradrenergic neuron pathways with i.c. 6-hydroxydopamine attenuated the hypotensive and bradycardic actions of both rilmenidine and clonidine at 2, 4, and 8 weeks after treatment. The maximum observed attenuation of the hypotension was at 8 weeks (40% of control for rilmenidine and 29% for clonidine), while for the bradycardia this was at 2 weeks (9 and 2% of control, respectively) with some recovery by 8 weeks (29 and 50% of control). Destruction of the central serotonergic neurons with i.c. 5,6-dihydroxytryptamine also attenuated the hypotension and bradycardia to rilmenidine and clonidine but was slower in onset, needing the full 8 weeks to reach its maximum effect. At this time the hypotension and bradycardia to rilmenidine and clonidine were reduced to between 35 and 48% of control.(ABSTRACT TRUNCATED AT 250 WORDS)

5,6-Dihydroxytryptamine↗
PubMed1991

The beneficial effect of lys-plasminogen upon the thrombolytic efficacy of urokinase in a dog model of peripheral arterial thrombosis.

The efficacy of thrombolytic therapy may be limited by local availability of plasminogen near a poorly perfused thrombus. The purpose of this study was to determine if the local (i.e., clot site) administration of 0.5 mg glu-plasminogen (glu-plg) or 0.5 mg lysplasminogen (lys-plg) could safely increase the thrombolytic efficacy of a 30-min intraarterial injection of 3,500 U kg-1 of two-chain urokinase plasminogen activator (UK) in a dog model of arterial thrombosis. Thrombolysis was measured by monitoring the continuous decrement of 125I-gamma emissions from a radiolabeled thrombus. Reflow was evaluated by a distally placed flowmeter and by direct visual examination. Forty-two dogs (mean weight 10.1 +/- 1.9 kg) were randomly sorted into six groups of 7 each. The dogs in each group were given either saline plus saline (group 1), saline plus UK (group 2), glu-plg plus saline (group 3), glu-plg plus UK (group 4), lys-plg plus saline (group 5), or lys-plg plus UK (group 6) by selective arterial catheterization 60 min after formation of an occlusive thrombus. Ninety minutes following drug administration, all groups which received UK (groups 2, 4, and 6) showed greater lysis (p less than 0.05) than the groups which received only saline or either glu- or lys-plg plus saline. Group 6, which received lys-plg plus UK, showed significantly greater lysis (34 +/- 4%) than both group 2 (23 +/- 2%), which received saline plus UK, and group 4 (19 +/- 3%), which received glu-plg plus UK (p less than 0.05). All dogs (7/7) in group 6 had reflow at 90 min whereas only 3/7 dogs had reflow in both groups 2 and 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

The protective effect of heparin in a dog model of rethrombosis following pharmacologic thrombolysis.

Rethrombosis is an important clinical problem for patients who have benefitted from pharmacologic thrombolysis. The present study describes a dog model of arterial thrombosis, which includes endothelial denudation, intimal damage, and stenosis, and is suitable for studying the phenomena of both thrombolysis and subsequent rethrombosis. The model was used to determine the effect of tissue-type plasminogen activator (t-PA), high and low dose heparin, and saline upon the incidence of rethrombosis after t-PA-induced thrombolysis. Initial thrombolysis with reflow was achieved with 0.4 mg/kg t-PA, intravenous bolus injection, followed immediately by 0.4 mg/kg t-PA, 30 min infusion, in 40 of 42 dogs (95%) that had an occlusive, 125I-labelled thrombus created in a segment of femoral artery. The 40 dogs in which reperfusion was achieved were randomly sorted into 4 groups of 10 each which then received either saline, t-PA (0.4 mg kg-1 infused over 1 h), low dose heparin (500 U bolus injection then 250 U h-1 for 24 h), or high dose heparin (1,500 U bolus injection then 500 U h-1 for 24 h). Sixty percent (6/10) of the saline treated dogs showed occlusive rethrombosis at 24 h. The incidence of occlusive rethrombosis was 9/10 in the t-PA treated group (p = NS), 3/10 in the low dose heparin treated group (p = NS), and 0/10 in the high dose heparin treated group (p less than 0.01). Two smaller groups consisting of 5 dogs each were treated with either saline or high dose heparin alone (no t-PA). None of the dogs in either group showed thrombolysis with reflow.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Gastrointestinal bleeding in a 15 month old male. A presentation of Munchausen's syndrome by proxy.

Munchausen's syndrome by Proxy is a well-described entity that may not always be immediately considered in a complicated case. We describe this syndrome being portrayed through the guise of gastrointestinal bleeding in a 15 month old male and discuss not only the difficulty involved in solidifying this diagnosis but also the consequences that may occur should this diagnosis not be entertained. Failure to diagnose Munchausen's syndrome by proxy often results from failure to consider the diagnosis. These cases frequently have specific characteristics that allow seasoned clinicians to suspect the diagnosis. Once the diagnosis is considered, it is crucial to take steps to protect not only the index patient but also siblings who not infrequently are also recipients of this life threatening form of child abuse.

Child Abuse↗
PubMed1990

Comparison of the effects of two viscoelastic agents, Healon and Viscoat, on postoperative intraocular pressure after penetrating keratoplasty.

Sixty-two patients undergoing penetrating keratoplasty were randomized to receive Healon (1% sodium hyaluronate) or Viscoat (3% sodium hyaluronate and 4% chondroitin sulfate) as a means of maintaining the anterior chamber during surgery. Neither viscoelastic agent was irrigated from the eye at the end of the procedure. Intraocular pressures (IOPs) were measured at 4, 10, 24, and 72 hours postoperatively. For the Healon group, IOPs were 16.52, 23.50, 28.31, 23.27, and 16.03 mm Hg at baseline and at the four follow-up periods, respectively. For the Viscoat group, they were 19.10, 28.33, 23.48, 18.62, and 16.17 mm Hg at those points, respectively. IOPs were significantly elevated over baseline in the Healon group at 4, 10, and 24 hours, and in the Viscoat group at 4 and 10 hours. There were no statistically significant differences between the Healon and Viscoat groups at 4, 10, and 72 hours. At 24 hours, the Healon group had a mean pressure rise over baseline of 6.5 mm Hg, while the Viscoat group had returned to baseline levels (P = .02). We conclude that both Healon and Viscoat raise postoperative IOPs, but that Healon appears to elevate IOPs for a longer period after surgery than Viscoat.

Adolescent↗
PubMed1986

Detection of proopiomelanocortin mRNA by in situ hybridization with an oligonucleotide probe.

Synthetic oligonucleotide probes can be easily obtained and used, in contrast to cDNA cloning to develop probes, and thus the present study was carried out to determine whether such probes could also be useful for in situ hybridization. A 24-base synthetic oligonucleotide complementary to part of the alpha-melanocyte-stimulating hormone (alpha-MSH) coding region of proopiomelanocortin (POMC) mRNA was 5'-end-labeled by using [gamma-32P]ATP with T4 polynucleotide kinase or was 3' tailed by using [alpha-32P]dATP or [3H]dCTP with terminal deoxynucleotidyltransferase. Blot analysis of pituitary poly(A)+ RNA showed that the oligonucleotide hybridized to a single species with a molecular size of approximately 1200 nucleotides, consistent with that determined previously for POMC mRNA. The oligonucleotide, regardless of labeling method, hybridized to cells in the pituitary intermediate lobe, but not in the posterior lobe. Only the 3H-labeled probe gave resolution of individual pituitary anterior lobe cells. The specificity of the hybridization was determined by showing that the intermediate lobe signal was blocked by prehybridization of the tissue with unlabeled alpha-MSH oligonucleotide probe. Furthermore, the hybridized probe exhibited a sharp sigmoid curve when melted off. Finally, the oligonucleotide probe detected, in situ, the haloperidol-induced elevation of intermediate lobe POMC mRNA. Thus, the oligonucleotide probe exhibited hybridization in an anatomically and biochemically specific manner, and it detected a tissue-specific change in mRNA levels in situ.

Animals↗
PubMed1986

Hypothalamic dynorphin and vasopressin mRNA expression in normal and Brattleboro rats.

Peptides derived from prodynorphin and provasopressin precursors coexist within neurosecretory vesicles of magnocellular neurons of the rat hypothalamus projecting to the posterior pituitary. The secretory activity of these neurons can be stimulated with physiological manipulations that elevate plasma levels of vasopressin (VP), such as dehydration and salt-loading. Evidence indicates that both VP- and prodynorphin-derived peptides are secreted under such conditions. With chronic osmotic challenge, the mRNAs for both prodynorphin and provasopressin increase in parallel in the supraoptic and paraventricular nuclei of the hypothalamus, and not within nonmagnocellular cell groups projecting elsewhere in the brain. The results indicate an example of coordinate regulation of mRNA expression for coexisting peptides within the brain. These results from microdissected tissues have been coupled with the more anatomically precise method of in situ hybridization histochemistry. Using 35S-radiolabeled synthetic oligonucleotides complementary to VP and dynorphin mRNAs, these mRNAs have been autoradiographically localized to magnocellular parikarya in the rat hypothalamus. Results also indicate that this technology can be used for regulatory studies, as evidenced by the increased hybridization of VP oligonucleotide to hypothalamic nuclei from salt-loaded rats.

Animals↗
PubMed1985

Lymphedema of the lower abdominal wall in pregnancy.

Two patients with lymphedema of the lower abdominal wall in late pregnancy are presented. Prominent tortuous, dilated lymphatic channels were observed clinically. Mechanical obstruction of lymphatic drainage is thought to be the cause. Both patients improved after delivery.

Abdominal Muscles↗
PubMed1977

Pulmonary allescheriasis: report of a case from Ontario, Canada.

A case of pulmonary allescheriasis in a 53-year-old woman residing in London, Ontario, Canada, is described. This patient entered the hospital complaining of dyspnea, a productive cough, and pains in the neck and left shoulder. Roentgenograms of the chest revealed a large cavity in the upper lobe of the right lung, and xerograms showed an intracavitary mycetoma. Monosporium apiospermum, the imperfect form of the fungus Allescheria boydii, was grown from her sputum and from the mycetoma as well. Treatment with amphotericin B had no effect on the infection, and the upper lobe of the right lung was resected. The cough cleared completely and the patient made an excellent recovery. This case of pulmonary allescheriasis once again emphasizes that the most satisfactory form of treatment available at present for this mycosis is surgical excision of the infected area.

Female↗