Surface shield: device to reduce personnel radiation exposure

A simple device is described that can reduce personnel exposure from scatter radiation by up to 75%. The device consists of an oblong piece of shielding (0.75-mm lead equivalent) that is taped to the side of the patient during percutaneous renal stone removal and other interventional procedures. Contrary to other shields and barriers, this does not interfere with access to the patient. Scatter exposure data from phantom studies are presented and the rationale for surface shielding discussed.     

Systemic lupus erythematosus presenting as chronic serositis with no demonstrable antinuclear antibodies

Approximately 5 percent of patients with systemic lupus erythematosus by clinical and pathologic criteria have no demonstrable antinuclear antibodies. This figure is likely to be an underestimate, as it does not include the antinuclear antibody-negative patients with limited manifestations in whom the diagnosis of systemic lupus erythematosus is missed. A 23-year-old woman is described who had a history of perplexing bilateral pleural effusions with development of peritoneal effusion after 18 months and positive antinuclear antibody results after 22 months. Tissue pathologic features, initially interpreted as nonspecific, on review revealed striking lymphocytic periarteritis with endothelial swelling and leukocytoclastic vasculitis often seen in systemic lupus. A selective defect in the suppression of T cell effector function, such as direct cell-mediated cytotoxicity, with intact suppressor systems for B cell effector function, such as antibody production, can be postulated in this patient. This would explain the active cellular tissue pathology with the lack of prominent antinuclear antibody production.     

Changes in serotonin levels, N-acetyltransferase activity, hydroxyindole-O-methyltransferase activity, and melatonin levels in the pineal gland of the Richardson's ground squirrel in relation to the light-dark cycle

Pineal serotonin and melatonin levels and the activities of hydroxyindole-O-methyltransferase (HIOMT) and N-acetyltransferase (NAT) were studied over a 24-hour period in the pineal gland of the diurnally active Richardson's ground squirrel (Spermophilus richardsonii). Under alternating light-dark conditions (light:dark hours 14:10), pineal serotonin and melatonin levels exhibited a rhythm with high values occurring either during the day (serotonin) or during the night (melatonin). NAT activity was also markedly increased during darkness. HIOMT activity exhibited no 24-hour variation. Exposure of squirrels to constant light for 7 days exaggerated the serotonin rhythm, but obliterated the cycles of NAT and melatonin. Under constant darkness (for 7 days), the rhythms in serotonin, melatonin and NAT persisted, each having a period of about 24 h. In the second study, ground squirrels were exposed to light-dark cycles of either 8:16, 10:14 or 14:10. Under each of these photoperiodic environments, rhythms in pineal NAT and melatonin were apparent. Increasing the daily dark period from 10 to 14 h caused a prolongation of the elevated NAT and melatonin levels. However, a further prolongation of the daily dark period (to 16 h) did not further increase the duration of the rise in NAT and melatonin. The results show that continual light exposure (irradiance of 200 microW/cm2) for 7 days suppresses the pineal rhythms in both NAT activity and melatonin level in the Richardson's ground squirrel. Conversely, light exposure, rather than depressing the serotonin rhythm, actually exaggerates it. Constant darkness for 7 days has little influence on the 24-hour rhythms of either NAT or melatonin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Monitoring systemic oxidative stress in an animal model of amyotrophic lateral sclerosis

A mutant form of the ubiquitous copper/zinc superoxide dismutase (SOD1) protein has been found in some patients with amyotrophic lateral sclerosis (ALS). We monitored oxidative stress in an animal model of ALS, the SOD^G93A mouse, which develops a disease similar to ALS with an accelerated course. The aim of this work was to show that ALS damages several organs and tissues, from an oxidative stress point of view. We measured lipid and protein oxidative damage in different tissue homogenates of SOD^G93A mice. The biomarkers that we analyzed were malondialdehyde + 4-hydroxyalkenal (MDA + 4-HDA) and carbonyls, respectively. The spinal cord and brain of SOD^G93A mice showed increased lipid peroxidation after 100 or 130 days compared to age-matched littermate controls. The CNS was most affected, but lipid peroxidation was also detected in the skeletal muscle and liver on day 130. No changes were observed in protein carbonylation in the homogenates. Our results are consistent with a multisystem etiology of ALS and suggest that oxidative stress may play a primary role in ALS pathogenesis. Thus, oxidative stress represents a potential biomarker that might be useful in developing new therapeutic strategies for ALS.     

Differential effects of granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor in children with severe congenital neutropenia.

Severe congenital neutropenia (SCN) is a disorder of myelopoiesis characterized by severe neutropenia secondary to a maturational arrest at the level of promyelocytes. We treated five patients with SCN with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) for 42 days and subsequently, between 1 and 3 months later, with rhG-CSF for 142 days. The objective was to evaluate the safety and ability of these factors to elicit a neutrophil response. rhGM-CSF was administered at a dose of 3 to 30 micrograms/kg/d (30 to 60 minutes, intravenously). In all patients, a specific, dose-dependent increase in the absolute granulocyte counts was observed. However, in four patients this increase was due to an increase in eosinophils, and in only one patient it was due to an increase in the absolute neutrophil counts (ANC). Subsequently, all patients received rhG-CSF at a dose of 3 to 15 micrograms/kg/d subcutaneously. In contrast to rhGM-CSF treatment, all five patients responded to rhG-CSF during the first 6 weeks of treatment with an increase in the ANC to above 1,000/microL. The level of ANC could be maintained during maintenance treatment. In one patient, the increase in ANC was associated with an improvement of a severe pneumonitis caused by Peptostreptococcus and resistant to antibiotic treatment. No severe bacterial infections occurred in any of the patients during CSF treatment. All patients tolerated rhGM-CSF and rhG-CSF treatment without severe side effects. These results demonstrate the beneficial effect of rhG-CSF in SCN patients.     

Effects of upright posture on atrioventricular accessory pathway conduction

The electrophysiologic effects of 45 degrees head-up tilt were studied in 19 patients with atrioventricular accessory pathways. Upright posture enhanced both anterograde and retrograde accessory pathway conduction when compared to the supine position: the anterograde block cycle length decreased from 374 +/- 52 ms (mean +/- standard error) (supine) to 303 +/- 33 ms (tilt) (p less than 0.05); anterograde effective refractory period decreased from 286 +/- 17 to 249 +/- 10 ms (p less than 0.05); retrograde block cycle length shortened from 331 +/- 36 to 291 +/- 35 ms (p less than 0.05); retrograde effective refractory period decreased from 312 +/- 26 ms to 274 +/- 15 ms (p less than 0.05). During induced atrial fibrillation the mean RR interval and the shortest RR interval between preexcited beats decreased approximately 10% with head-up tilt. During orthodromic reciprocating tachycardia, tachycardia cycle length shortened 15%. Tachycardia rate during electrophysiologic study in the head-up position more closely approximated the rate of clinical tachycardia than did the rate in the supine position. Head-up tilt significantly enhances anterograde and retrograde accessory pathway conduction, increases the rate of arrhythmias using an accessory pathway and may be clinically useful in the assessment of patients with an accessory pathway.     

Radical prostatectomy then and now: Surgical overtreatment of prostate cancer is declining from 2009 to 2016 at a tertiary referral center

Background

In the era of increasing scrutiny of delivery of quality care, efforts to decrease surgical overtreatment of insignificant prostate cancer (iCaP) continue.

Dimeric versus monomeric nonionic contrast agents in visualization of coronary arteries

A cubital intravenous iodine contrast agent enhancement is used to visualize coronary arteries using EBT. The quality of the coronary artery visualization however is limited by the nearly simultaneous approximation of CT values in coronary arteries and myocardial tissue. The objective of the study was to evaluate if "under real clinical circumstances" the lower iodine concentration and the dimeric based characteristic of iodixanol may effect the kinetic of the applied contrast agent and the visualization of coronary arteries studied noninvasively by EBT. A double-blind, randomized, parallel study was performed in 111 cardiac patients, using iodixanol 270 mg I/ml or iohexol 300 mg I/ml. The kinetics of contrast enhancement was studied in the flow mode measuring following parameters: mean arrival time and mean time to reach peak CT values in the pulmonary trunk, transit time from the pulmonary trunk to the aorta as well as mean and maximum CT values in the left ventricular chamber and in the myocardium with respect to the body mass index. The mean difference of CT values in the left ventricular chamber and the myocardium was calculated. The length of the visualized coronary arteries was assessed and the diagnostic quality of coronary artery visualization scored on a visual analogue scale. Although iodixanol was used with a lower iodine concentration than iohexol there was no significant statistical difference between both groups with respect to the diagnostic visualization and length assessment of the coronary arteries as well as in the mean difference of CT values in the left ventricular chamber and the myocardium. This means that the advantageous dimeric characteristics of iodixanol may be used to reduce the amount of applicated iodine in contrast agents without loss of diagnostic image quality and information.