Effects of alpha-tocopherol, phenobarbital, and butylated hydroxyanisole during promotion of diethylnitrosamine-initiated rat hepatocarcinogenesis

The promotion-suppressing ability of two antioxidants was measured to determine the role of oxidative stress in hepatocarcinogenesis. Four-day-old female F344/N rats were dosed with diethylnitrosamine (10 mg/kg). After weaning, they were fed semipurified diets with and without 500 ppm alpha-tocopherol, or the same two diets containing 500 ppm phenobarbital, or 5,000 ppm butylated hydroxyanisole (BHA) for 3 or 11 months. By 11 months, phenobarbital-fed groups had eaten 30% more than other groups did (p less than 0.05), suggesting a role for increased caloric intake in phenobarbital promotion. Phenobarbital and BHA significantly reduced body weights and increased liver weights compared with control rats. After three months, alpha-tocopherol significantly suppressed mean volume of placental glutathione S-transferase (PGST)-positive altered hepatic foci (AHF), regardless of xenobiotic treatment. Phenobarbital increased and BHA decreased the numbers of AHF compared with those of the control group. After 11 months, mean focal volume was significantly suppressed by BHA compared with that of the control group, and phenobarbital increased the total volume of AHF [PGST-positive plus gamma-glutamyltransferase (GGT)-positive AHF] compared with rats fed either control or BHA diets. BHA treatment also increased hepatic glutathione levels by 40% compared with control and rats fed phenobarbital. In conclusion, alpha-tocopherol had only a slight, early effect to suppress promotion of hepatocarcinogenesis. BHA suppressed some indices of promotion at both times and increased hepatic glutathione; however, BHA's toxicity (which suppressed body weight) may also be a factor in its supposable promotion-inhibitory effects.

Phenobarbital increases rat hepatic prostaglandin F2 alpha, glutathione S-transferase activity and oxidative stress

Eight-week-old female F344/N rats were fed 3.0 or 6.0% of calories (kcal%) as linoleate with or without 0.05% phenobarbital (PB) for 35 days. PB treatment increased glutathione S-transferase (GST) activity by 80% and prostaglandin (PG) F2 alpha levels 4-fold (p less than 0.05). PB decreased hepatic alpha-tocopherol significantly. Hepatic linoleate was decreased by PB in rats fed 6 kcal% but not 3 kcal% linoleate. Increased dietary linoleate had no significant effect on hepatic PGF2 alpha or alpha-tocopherol levels or GST activity. This study suggests that PB hepatotoxicity and tumor-promoting ability may be mediated, at least in part, by PGF2 alpha. PB's effect on PGF2 alpha could be a result of both GST-mediated prostaglandin synthesis and oxidative stress. The removal of significant amounts of hepatic alpha-tocopherol during oxidative stress induced by PB might diminish endogenous inhibition of hepatic PG synthesis by a-tocopherol.

Effects of postnatal ethanol exposure on glial cell development in rat optic nerve

This study morphologically evaluated the effects of limited postnatal alcohol exposure on the development of glial cells in the rat optic nerve. Rat pups were artificially reared on Days 5-18 with a supplemented milk diet fed via a chronic gastrostomy tube. Experimental animals received 4% ethanol in their diet on Days 5-9, otherwise the experimental and control animals received identical diets. Optic nerve tissues were prepared for electron microscopy on Days 10, 16, 22, 29, and 90. There were fewer glial cells per cross section and the cross-sectional areas of optic nerves were smaller on Days 10 and 16 in the ethanol-exposed animals. The alcohol caused a delay in the maturation of oligodendroglial cells at 10 days as evidenced by decreases in the total number of oligodendroglia present and by a delay in the appearance of immature cells within the oligodendroglial lineage. All of these effects were compensated for at later ages. There was no evidence of alcohol-induced degeneration of glial cells or their organelles. Thus, postnatal alcohol exposure causes a delay in oligodendrocyte maturation but appears to have no long-term effects on the glial cell population of rat optic nerve.

Accurate determination of the transaortic valve gradient using simultaneous left ventricular and femoral artery pressures

Accurate determination of the transaortic valve gradient has required two catheters, one in the left ventricle and one in the ascending aorta. We now report a new technique for measurement of the transaortic valve gradient from the simultaneous left ventricular (LV) and femoral artery (FA) pressure tracings. This technique was compared with the "true" gradient obtained by measurement of the simultaneous LV and central aortic pressures, and is accurate (R = 0.999) and relatively simple. Other approaches used to determine the mean transaortic valve gradient were less accurate: simultaneous LV-FA (R = 0.991); aligned LV-FA (R = 0.974); averaged simultaneous and aligned LV-FA (R = 0.981); and nonsimultaneous LV-aorta pullback (R = 0.953). Thus, this new technique provides an accurate transaortic valve gradient without requiring the use of two central catheters.

Comparison of three techniques for percutaneous balloon aortic valvuloplasty of aortic stenosis in adults

Three different techniques for percutaneous balloon aortic valvuloplasty h have been described: retrograde single balloon, retrograde double balloon, and antegrade techniques. This report describes our experience using the three techniques in twenty-five consecutive procedures. All techniques resulted in a significant decrease in transvalvular pressure gradient and an increase in calculated aortic valve area, without significant difference among the three. There was no increase in the degree of aortic regurgitation after valvuloplasty by any of the techniques. Vascular complications occurred only with the retrograde double balloon technique. Cardiac tamponade during balloon inflation occurred with both the retrograde single and double balloon techniques. Three deaths occurred; two during the antegrade technique and one after the retrograde double balloon technique. Thus, balloon aortic valvuloplasty can be effectively performed using any of the three techniques. However, the differing techniques have inherent advantages in specific situations, as well as potential complications.

Right-to-left shunt through patent foramen ovale complicating right ventricular infarction. Successful percutaneous catheter closure

A patient with right ventricular infarction and severe hypoxemia secondary to right-to-left shunting through a patent foramen ovale is presented. A balloon tip catheter was positioned in the left atrium and retracted against the atrial septum and the hypoxemia resolved.

Echocardiographic evaluation of potential cardiac transplant donors

Since the initiation of the UTAH Cardiac Transplant Program, echocardiography has been used to evaluate 74 potential donors including 65 of 71 hearts ultimately used for transplantation. Of these 65 donors, 46 had normal studies, nine had pericardial effusions, five had mild septal hypokinesia with otherwise normal function, four had equivocal mitral valve prolapse, and only one heart could not be visualized. All transplants were successful and all donor hearts exhibited satisfactory hemodynamic function immediately after transplantation, including the hearts that were mildly abnormal before transplantation. These hearts included 21 (29%) that could have been excluded by conventional screening criteria. Nine potential donor hearts with grossly abnormal echocardiograms were not used for transplantation, including eight hearts with severe hypokinesia and one heart with significant mitral and tricuspid regurgitation. Inspection or histologic analysis confirmed the presence of severe dysfunction or morphologic damage in those hearts subjected to these additional measures. We conclude that echocardiographic screening is a useful method of evaluating potential cardiac transplant donors. It can identify potential donors that would otherwise have been excluded and it can identify potential donors with severe cardiac dysfunction without the need for direct surgical inspection.

Temporary pacemaking by general internists

The medical records of 126 patients requiring 129 temporary pacemakers were viewed retrospectively. The pacemakers were inserted by general internists using venous access from subclavian and internal jugular veins under ECG guidances. Fluoroscopy was not used. There was 14% incidence of pacemaker electrode malfunction and a 4% risk of complication with no pacemaker-related mortality. These results compare favorably with reports from university cardiology services. Temporary pacemakers can be safely inserted by general internists without fluoroscopy.

Protein-losing enteropathy complicating the Mustard procedure

Protein-losing enteropathy is a reported complication of several cardiac diseases. Recently we encountered a patient with protein-losing enteropathy acquired as a late surgical complication of the Mustard procedure. An obstructed superior vena caval conduit was repaired surgically and the enteropathy was resolved.

Membranous subaortic stenosis complicated by aneurysm of the membranous septum and mitral valve prolapse

The clinical, echocardiographic, and catheterization findings in a patient with discrete subaortic stenosis, aneurysm of the membranous interventricular septum, and mitral valve prolapse are presented. Echocardiography showed a subaortic membrane, abnormal aortic valve motion, accentuated systolic anterior motion of the membranous interventricular septum, and prolapsing mitral leaflets. Cardiac catheterization confirmed the diagnoses. The possible functional interrelationship of these lesions is discussed.

Left atrial appendage aneurysm: correlation of noninvasive with clinical and surgical findings: report of a case

Congenital left atrial appendage aneurysm is rarely diagnosed on the basis of an abnormal cardiac silhouette. Patients with a left atrial appendage aneurysm often present with symptoms of systemic emboli or supraventricular arrhythmias. A patient with left atrial appendage aneurysm was diagnosed by correlation of two noninvasive techniques echocardiography and radionuclide scintiscanning. Angiography was confirmatory and aneurysmectomy was successfully performed.

Echocardiographic Mimics of aortic root dissection

Echocardiograms were recorded in two patients with suspected aortic root dissection. In the first patient with a massive pulmonary embolus, a simultaneous recording of the mitral ring and posterior aortic wall created a pattern similar to true posterior aortic wall dissection; in the second patient with severe generalized atherosclerosis, thickened aortic walls recorded echocardiographically were found at autopsy to be atherosclerotic plaques. These cases emphasize the potential for the false positive ultrasonic diagnosis of aortic root dissection.