Thoracic tumors in children with neurofibromatosis-1

Lymphocytes were isolated from volunteers before and after receiving a single supplement of vitamin C, vitamin E or beta-carotene. The lymphocytes were treated with H2O2, and DNA strand breaks were measured by single cell gel electrophoresis (the comet assay). Significant protection against oxidative DNA damage was evident 2-4 h after vitamin C intake, and 18-24 h after consumption of the other antioxidants. Lymphocytes from smokers were more sensitive to DNA damage than those from non-smokers, and they showed at least as great a protective effect with antioxidants.     

Erectile response to transurethral alprostadil, prazosin and alprostadil-prazosin combinations

PURPOSE: Transurethral alprostadil has been shown to be efficacious in many men with erectile dysfunction. We compared transurethral alprostadil and prazosin alone, and in combination to treat this disorder. MATERIALS AND METHODS: In this double-blind, placebo controlled study the erectile responses to transurethral alprostadil, prazosin and alprostadil-prazosin combinations were assessed in 234 men 26.8 to 81.5 years old with complete organic erectile dysfunction. Patients self-administered a random sequence of 7 doses in the clinic in 4 weeks. The erectile response was assessed using categorical and visual analog scales. RESULTS: Full penile enlargement or rigidity was achieved by 165 of the 234 men (70.5%) after at least 1 active dose of medication. The most effective alprostadil dose (500 microg.) resulted in full penile enlargement or rigidity in 51.8% of administrations, whereas the most effective prazosin dose (2,000 microg.) and placebo resulted in a similar response in 12.7 and 2.7%, respectively (p <0.001). The 500/2,000 microg. alprostadil/prazosin combination, which resulted in full enlargement or rigidity in 58.9% of doses, was only slightly better than the most effective dose of alprostadil alone (500 microg.). However, combinations of 125/500 and 250/500 microg. alprostadil/prazosin were more effective (p <0.01) than 125 and 250 microg. alprostadil given alone, respectively. The most common side effect of therapy was penile pain, which rarely led to study discontinuation. Hypotension most commonly developed at the higher alprostadil-prazosin combination. CONCLUSIONS: Transurethral alprostadil and alprostadil-prazosin combinations produced erections in men with complete organic erectile dysfunction. This combination therapy may be an option in patients who do not respond to transurethral alprostadil alone.     

Autonomic effects on noise recorded during signal-averaged electrocardiography

The purpose of this study was to assess the effects of autonomic stimulation and blockade on noise levels and to compare the noise measurements in the ST and TP segments of the signal-averaged ECG. Five-minute electrocardiographic data were recorded in 14 normal volunteers (8 males and 6 females; mean age 28.5 +/- 5.0 years) on two separate days (day 1-baseline, epinephrine infusion, isoproterenol infusion, beta-blockade, and combined adrenergic and parasympathetic blockade; day 2-baseline, phenylephrine infusion, parasympathetic blockade, and during phenylephrine infusion following atropine). Signal averaging was done off-line on 100 beats and noise was measured in both the ST and TP segments as the standard deviation of voltage in the segment of interest. For all conditions tested, the mean noise level measured in the ST segment (0.46 +/- 0.16 microV) was significantly less than that measured in the TP segment (0.52 +/- 0.24 microV; P = 0.0003), but there was good correlation between the noise measured in the ST and the TP segment (R2 = 0.62, P < 0.0001). Noise increased with isoproterenol infusion and decreased following adrenergic blockade. In addition, day 2 baseline noise was less than baseline noise on day 1. Finally, neither parasympathetic stimulation or blockade nor alpha-adrenergic stimulation significantly affected signal-averaged electrocardiography (SAECG) noise levels. Thus, the data support the notion that enhanced sympathetic tone increases noise levels and beta-adrenergic blockade may decrease noise levels, likely due to effects from muscle sympathetic nerve activity. These findings are important since the target population for the SAECG are patients with myocardial infarction and congestive heart failure, conditions associated with increased sympathetic tone, which may in turn impact on the reproducibility or technical aspects of the SAECG. In addition, because noise in the ST and TP segments are highly correlated and the noise measured in the ST segment is less than that in the TP segment, uniform adoption of noise measurement in the ST segment seems most appropriate.     

Microleakage of multi-step and simplified-step bonding systems

PURPOSE: To measure and compare the microleakage of Class V resin composite restorations using the following three pairs of multi- and simplified-step dentin bonding systems (DBS): OptiBond vs. OptiBond FL, All-Bond 2 vs. One-Step, and Tenure vs. Tenure Quik. MATERIALS AND METHODS: V-shaped cavities were prepared in the mesial and distal surfaces of 30 extracted human mandibular molars with margins in both enamel and cementum, and randomly assigned into three equal groups of 10 each. All DBSs were applied strictly following manufacturers' specifications before three incremental layers of resin composite (Pertac-Hybrid) were applied in all cavities. Specimens were stored for 7 days in 37 degrees C water, thermocycled for 300 cycles between 5 degrees C and 55 degrees C, immersed in 0.5% basic fuchsin solution for 24 hours, and embedded in resin before being sectioned longitudinally in multiple sections. Dye solution penetration at the tooth/composite interface was scored from 0 to 4 under a microscope at x100 at both enamel (E) and cementum (C) margins. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests with alpha = 0.05. RESULTS: OptiBond FL and One-Step showed less microleakage at the cementum margins compared to their multi-step versions. At the enamel margins Tenure Quik showed less microleakage compared to Tenure, and none of the other DBSs tested showed significant dye penetration at that interface. All DBSs showed significantly less microleakage at the enamel margins compared to the cementum margins except for OptiBond FL and One-Step that did not show any significant dye penetration at the cementum margins as well.     

Presidential address. Changing world of health care competition and the spinal neurosurgeon

A case of early autograft endocarditis occurring three weeks after a Ross operation is described. The origin of the infection appeared to be the proximal suture line of the autograft and the pathology included subvalvular destruction of the autograft, a pseudoaneurysm between the autograft and the left atrium, and a fistula to and a vegetation in the roof of the left atrium. The valve cusps were unaffected and there was only slight autograft insufficiency (grade I-II). The autograft was removed and successfully replaced with a homograft.     

Three- to 5-year prospective follow-up of outcome in major depression

STUDY OBJECTIVES: Recurrent chylothorax as a complication of lymphoma has had unsatisfactory outcomes. Serial thoracentesis, tube thoracostomy, and pleurodesis via chest tube have been ineffective and compromise the nutritional and immune status of the patient. Medical thoracoscopic talc pleurodesis has been safe and effective in the treatment of some other varieties of recurrent pleural effusions. Our objective was to investigate the safety and efficacy of medical thoracoscopic talc pleurodesis in the palliation of chylothorax related to lymphoma. DESIGN: This is a report of 24 hemithoraces treated in 19 consecutive patients with lymphoma-related chylothorax, failing chemotherapy or radiation therapy. The average patient age was 55 years. INTERVENTIONS: Medical thoracoscopy was performed under local anesthesia and conscious sedation in a bronchoscopy suite. Sedation included midazolam (mean dose, 6 mg; range, 2-14 mg) with either meperidine (mean dose, 94 mg; range 25-140 mg), or morphine (mean dose, 18 mg; range 4-40 mg). Pleurodesis was performed with insufflation of sterile asbestos-free talc, (4-8 g). After pleurodesis, chest tubes were placed, with the mean duration of chest tube placement being 4 days, range 3 to 10 days. RESULTS: One patient died a few days after the procedure due to causes related to the primary disease process. Follow-up was for at least 90 days following the procedure. Patients were assessed at 30, 60, and 90 days following the procedure. At each of these endpoints, all patients remaining alive were without recurrence of pleural effusions, which was confirmed by chest radiography. Eight patients in the series died of the effects of their malignancy during the 90-day evaluation interval. Complications included medication reactions in two patients (8.3%) and ARDS in one patient (4.1%). CONCLUSION: Many patients with lymphoma-related chylothorax are refractory to chemotherapy and/or radiation therapy. In this group, medical thoracoscopic talc pleurodesis has an acceptable complication rate and a 100% success rate in the prevention of recurrence of pleural effusions at 30, 60, and 90 days following the procedure.     

Plasma lipoprotein (a) levels in men and women consuming diets enriched in saturated, cis-, or trans-monounsaturated fatty acids

Studies that have shown adverse effects of trans-unsaturated fatty acids on plasma lipoprotein (a) [Lp(a)] levels have used levels of trans-fatty acid that are higher than those in the average U.S. diet. This study was conducted to clarify the effects on Lp(a) of trans-fatty acids levels commonly found in U.S. diets. Lp(a) levels were measured in a double-blind study of 29 men and 29 women who ate 4 controlled diets in random order for 6 weeks each. Fatty acids represented 39% to 40% of energy. The diets were: (1) Oleic (16.7% of energy as oleic acid); (2) Moderate trans (3.8% of energy as trans-monoenes, approximately the trans content of the U.S. diet); (3) High trans (6.6% of energy as trans-monoenes); (4) Saturated (16.2% of energy as lauric plus myristic plus palmitic acids). The Saturated diet lowered Lp(a) levels significantly (by 8% to 11%). Compared to the Oleic diet, the trans diets had no adverse effect on Lp(a) levels when all subjects were considered collectively. A subset with initially high levels of Lp(a) (> or = 30 mg/dL), however, responded to the High trans diet with a slight (5%) increase in Lp(a) levels relative to the Oleic and Moderate trans diets. Thus, in amounts commonly found in the typical U.S. diet, saturated fatty acids consistently decrease Lp(a) concentrations. The adverse effects of replacing cis- with trans-fatty acids are only suggestive and are restricted to high trans intakes in subjects with high Lp(a) levels.     

Variations of hepatitis B virus core gene sequence in Western patients with chronic hepatitis B virus infection

Heterogeneity of the hepatitis B virus (HBV) core gene has been reported to be associated with the presence of active liver disease in Japanese patients with chronic HBV infection. This study evaluated the significance of HBV core gene heterogeneity in Western patients with chronic HBV infection. The hepatitis B virus precore/core gene from 45 patients (inactive:active liver disease ratio 16:29) was amplified from serum by polymerase chain reaction (PCR). Gel electrophoresis was employed to detect large deletions. The PCR amplicons from 13 patients (all HBV serotype adw but with a different spectrum of liver disease) were cloned and sequenced. Hepatitis B surface antigen (HBsAg) serotypes were tested by enzyme immunoassay (EIA) and hepatic expression of HBV antigens was assessed by immunohistochemistry. The HBV core gene was amplified from the serum of all 45 patients. Three patients had mixed infection with both precore mutant and wild-type HBV and all three had active liver disease. No patient had a large deletion of the HBV core gene. Hepatitis B virus core gene sequence variations were more common in the midcore region and there was no difference in the number of silent and missense substitutions between those with inactive and active liver disease. There was no correlation between the nucleotide or encoded amino acid substitutions and the clinical and biochemical parameters, including the subsequent response to interferon-alpha therapy (n = 37) or hepatic HBV antigen expression. Variation of the HBV core gene was not found to be preferentially associated with active liver disease in Western patients with chronic HBV infection. The pattern of hepatitis B core gene variation is in accord with the genomic organization of HBV.