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J Rhodes

Publications and source records attributed to J Rhodes.

357 records · Page 20Linked to original sources

Echocardiographic assessment of the right ventricular response to exercise.

Although exercise echocardiography has been widely used among adult patients, its application in the pediatric population has not been well explored. A few studies have examined the response of the pediatric left ventricle (LV) to exercise. However, although many congenital heart defects result in abnormalities of right ventricle (RV) anatomy and function, little is known about the RV's response to exercise. The purpose of this study was to assess the effect of exercise on RV dimensions and function and to compare the RV's response to that of the LV. Twenty-nine consecutive pediatric subjects (age 12.1 +/- 3.2 years) with structurally normal hearts, who were referred for exercise stress testing, were studied echocardiographically prior to and within 2 minutes following peak exercise. Adequate studies were obtained in 28 of the 29 patients. RV dimensions and area during the first 2 minutes following the termination of exercise were slightly smaller than those observed prior to exercise. However, the decline in RV area at end systole was proportionally greater than the decline in RV area at end diastole. Consequently, the RV fractional area change following exercise exceeded the preexercise value. The response of the LV to exercise was qualitatively similar to that observed for the RV. This study demonstrates that echocardiographic measurement of RV size and function immediately after exercise is feasible. Data from this study can be used as normal reference standards against which data from patients with congenital heart defects may be compared.

Adolescent↗

Immunoregulatory properties of novel specific inhibitors of 5-lipoxygenase.

The immunoregulatory properties of novel specific inhibitors of 5-lipoxygenase (5-LO) were investigated in vitro. These novel acetohydroxamic acids were found to inhibit the proliferation of lymphocytes in response to Interleukin-1 (IL-1) and Interleukin-2 (IL-2). Mitogen- and antigen-induced lymphoproliferation were likewise inhibited and so too was the spontaneous proliferation of transformed cells of myeloid and lymphoid origin. In this respect the compounds were one-tenth as potent as azathioprine on a molar basis. The production of IL-1 and IL-2 remained unaffected. Inhibition of lymphocyte proliferation was not related to inhibition of 5-LO. The latter occurred at 40-fold lower concentrations of 5-LO inhibitor. Moreover, inhibition of lymphoproliferation was not reversible in the presence of excess arachidonic acid. IL-1-induced collagenase production by chondrocytes was unaffected by 5-LO inhibitors. Contrary to a number of published reports, products of 5-LO do not appear to be obligatory mediators in IL-1 and IL-2 signal transduction. The immunosuppressive action of the 5-LO inhibitors described here seems to be a novel secondary property of the compounds.

Animals↗

A survey of the monosodium glutamate content of foods and an estimation of the dietary intake of monosodium glutamate.

The MSG contents of a wide range of manufactured foods (over 200 samples) were measured using the AOAC Procedure (ion-exchange chromatography followed by formol potentiometric titration). The results obtained were used, in conjunction with published data on UK food consumption, to calculate tentative estimates of the dietary intake of MSG for specific groups of the UK population.

Adolescent↗

Effect of dietary bran on serum lipids in patients with previous myocardial infarction, with gallstones, and in normal subjects.

Sixteen subjects received between 50 g to 121 g of wheat bran in their diet for between 6 to 26 weeks. Five were normal subjects, 5 had gallstones, and 6 young men had suffered a previous myocardial infarction. The serum cholesterol did not show any consistent change in the normal subjects, but there was a fall in cholesterol at 20 weeks in patients with gallstones; patients with previous myocardial infarction had a rise in cholesterol which returned to normal at 20 weeks. There was no significant change in the serum triglyceride.

Adult↗

A new low profile balloon atrial septostomy catheter: initial animal and clinical experience.

OBJECTIVE: To evaluate the safety and efficacy of a new low profile balloon septostomy catheter in neonatal animals as well as in one newborn infant. BACKGROUND: Balloon atrial septostomy remains one of the most commonly performed palliative procedures in pediatric cardiology. The currently available septostomy catheter requires a large introducer sheath (6 or 7F), does not have an end hole for confirmation of position or pressure measurement and is limited in patients with a small left atrium due to its large balloon inflated diameter. METHODS: Four neonatal piglets (average weight 3.9 kg) underwent percutaneous balloon atrial septostomy using the new balloon catheter inflated to 1 cc via a 5F sheath in the femoral vein. Two other piglets (average weight 4.9 kg) underwent septostomy with the conventional catheter inflated to 3.5 cc via a 6 or 7F sheath in the femoral vein. All animals underwent transthoracic echocardiography pre and post septostomy. All animals were sacrificed after the procedure and the size of the atrial defect created was measured. One neonate with Taussig-Bing anomaly underwent septostomy with the new balloon catheter. RESULTS: The left atrium was entered in all piglets. It was easier to enter the left atrium with an end hole catheter which was exchanged over a wire with the septostomy catheter. Septostomy was performed with the new or conventional catheters without complications. Echocardiography demonstrated a very small patent foramen ovale prior to the procedure and a large atrial defect after septostomy. The average size of the defect created by the new catheter was 11.3 x 10 mm in diameter and 11 x 10 mm using the conventional catheter. A 10 x 10 mm atrial communication was created in the neonate. CONCLUSIONS: This study demonstrates the safety and efficacy of this new catheter. This catheter will be of potential importance in patients with a small left atrium and in small neonates with congenital heart disease requiring septostomy.

Animals↗

The tarsal tunnel.

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Foot↗

Is transdermal nicotine associated with cardiovascular risk?

We had the unique opportunity to study the effects of transdermal nicotine on markers of haemostasis and serum lipids in patients with ulcerative colitis; all were non-smokers and were given transdermal nicotine to assess its value in maintenance therapy for colitis. In a controlled double-blind trial, 45 patients with ulcerative colitis in remission on 5-aminosalicylic acid, were randomly allocated to receive transdermal nicotine (20) or placebo (25) patches. Markers of haemostasis, including platelet activation (platelet volume and surface expression of P selectin), endothelial damage (plasma von Willebrand factor antigen) and plasma fibrinogen were measured at the beginning and after 12 weeks of treatment. The white cell count and serum lipids were also measured. Nicotine significantly lowered plasma fibrinogen but did not affect markers of platelet activation, endothelial damage, white cell count and serum lipids. The possibility that transdermal nicotine may beneficially influence cardiovascular risk factors warrants further exploration.

Administration, Cutaneous↗