Paraganglioma of the cauda equina with associated intramedullary cyst: MR findings.

The MR imaging features of a paraganglioma of the cauda equina with associated spinal cord cysts are presented. MR imaging showed the tumor to be isointense with the spinal cord on all pulse sequences and to enhance homogeneously. The intramedullary cysts had increased signal intensity on proton density- and T2-weighted images, and involved the cervical and thoracic regions.     

Benign osteoblastoma of the parietal bone

A 5-year-old girl presented with a 1-year history of a subcutaneous swelling in the right parietal region. There were no cerebral symptoms or signs. Plain X-ray of the skull showed a lytic bony lesion with sclerotic margin. Computed tomography showed a hypodense, osteolytic lesion with thinned and bulged inner and outer skull tables with intact continuity. There was no intracranial lesion. At operation, the mass was found to be pink and granular, and was totally enucleated. Histology revealed it to be a benign osteoblastoma.     

Unattached fraction and size distribution of aerosol-attached radon progeny in the open air

Unattached fractions of the radon progeny ²¹⁸Po and ²¹⁴Pb, size distributions for both unattached ²¹⁸Po and ²¹⁴Pb, and attached ²¹⁴Pb and ²¹⁴Bi, along with condensation nuclei (aerosol-particle concentrations), were measured in the open air of the city of El-Minia, Egypt. The measurements were performed with a wire-screen diffusion battery and a low-pressure Berner cascade impactor using standard methodologies. The results for parameters of derived distributions demonstrate that the distributions for the former (unattached ²¹⁸Po and ²¹⁴Pb) are nearly similar. The diffusion equivalent diameters (d_f) of ²¹⁸Po and ²¹⁴Pb were determined to be 1.4 and 1.55 nm with relative geometric standard deviations (σ_g) of 1.65 and 2.1, respectively. The latter distributions (attached ²¹⁴Pb and ²¹⁴Bi) are nearly identical. Most of the activities were associated with the aerosol particles of the accumulation mode. The mean activity median aerodynamic diameters (AMAD) of ²¹⁴Pb and ²¹⁴Bi have the same value of 380 nm but the relative geometric standard deviation of the log-normal distribution of ²¹⁴Pb shows a broader activity distribution than ²¹⁴Bi (σ_g = 2.2 for ²¹⁴Pb and σ_g = 2.05 for ²¹⁴Bi).     

Enhancement of transdermal delivery of 6-beta-naltrexol via a codrug linked to hydroxybupropion.

Naltrexone (NTX) is a potent opioid antagonist used in the treatment of alcohol dependence and heroin abuse. Compared with naloxone, NTX has a longer duration of action largely attributed to its major active metabolite, 6-beta-naltrexol. The purpose of this study was to increase the delivery of 6-beta-naltrexol across human skin in vitro via a novel codrug. A carbonate codrug of 6-beta-naltrexol linked to hydroxybupropion was synthesized and evaluated. In vitro human skin permeation rates were measured using a flow-through diffusion cell system. The drug melting points, solubilities, chemical stability, and skin disposition were determined. The carbonate codrug was hydrolyzed on passing through skin and appeared as a combination of intact codrug and parent drugs, 6-beta-naltrexol and hydroxybupropion, in the receiver solution. The codrug provided a significantly (p<0.05) higher 6-beta-naltrexol flux across human skin than 6-beta-naltrexol base. The extent of parent drug regeneration in the skin ranged from 56 to 86%. A higher stratum corneum partition coefficient and rapid bioconversion of the carbonate codrug in the skin correlated with increased 6-beta-naltrexol delivery rates.     

Histological, histochemical and electron microscopic changes of the placenta induced by maternal exposure to hyperthermia in the rat.

Both clinical and experimental investigations have shown that maternal hyperthermia during critical stages of embryo development can induce malformations in the offspring. Studies of the effect of heat stress on the placental functions are limited to the ewes, but that on microscopic structure is unknown. In the present study, rats were exposed to 41 or 42 degrees C for 1 h on gestation day (GD) 9. The controls were sham treated. Fetuses and placentas were collected on GD 20. Intrauterine growth retardation (IUGR) and several craniofacial malformations were observed in the fetuses of the heat-treated group. The placentas of the 42 degrees C group were significantly lighter in weight than those of the control. Light microscopy (LM) revealed thickening, hyalinization and occasional lymphocytic infiltration of the decidua basalis. Giant cells were prominent and glycogen cells had degenerated, leaving behind large cysts in the basal (spongy) zone. Best's carmine stain with or without diastase indicated the reduction in number and degeneration of glycogen cells and cyst formation. The labyrinthine zone was relatively thin in comparison to that of the controls. Perivascular fibrosis and paucity of vascularization were other features of the placentas of the hyperthermia group. Electron microscopy (EM) revealed lipid droplet accumulation in the trophoblast, the presence of myelin bodies and an increased production of collagen in the basal zone. Perivascular fibrosis appeared to have contributed to placental barrier thickening. EM also revealed accumulation of glycogen and lipid droplets in the trophoblasts and fibrin secretion into the extracellular space of the labyrinthine zone. These data suggest that placental pathology possibly contributes to fetal growth retardation in maternally heat-stressed rat fetuses.     

Pulsed mode versus near-continuous mode delivery of diode laser photocoagulation for high-risk retinopathy of prematurity.

OBJECTIVE: To compare structural and functional outcomes and efficiency of diode laser photocoagulation for retinopathy of prematurity (ROP) when delivered in a pulsed mode versus a near-continuous mode. METHODS: A retrospective study was conducted of 138 patients who underwent diode laser photocoagulation for threshold ROP using either pulsed or near-continuous delivery. Laser-related complications and structural and functional outcomes were analyzed. Prospectively, time efficiency and total energy used were evaluated in nine infants with bilateral symmetric high-risk prethreshold ROP in which one eye of each infant was randomized to pulsed and the fellow eye to near-continuous delivery. RESULTS: There was no significant difference between groups with regards to prevalence of posterior disease (Zone 1 or posterior Zone 2) (p = 0.11), postoperative vitreous haze (p = 0.60), postoperative complications (p = 0.38), retinal detachment (p = 0.90), strabismus (p = 0.73), amblyopia (p = 0.69), or refractive error (p = 0.95). Mean time for treatment was 23 minutes using pulsed delivery versus 14 minutes per eye with near-continuous delivery (p < 0.001). The mean total power used per eye with pulsed mode delivery was 1.5 x 10(5) W versus 1.1 x 10(5) W with near-continuous delivery (p = 0.015). CONCLUSIONS: No differences in complications, functional outcome, or structural outcome were found between using pulsed mode and near-continuous mode diode laser delivery for high-risk ROP. Near-continuous laser delivery, in our hands, was more time-efficient and used less total power.     

A suggested clinical score to predict the severity of adenoid obstruction in children

Chronic nasal obstruction in children is a very common disorder. Obstructing adenoid is usually the first to blame. Though the clinical assessment is essential, it is often considered unreliable or insufficient. We conducted a prospective clinical study to validate a clinical score predicting the severity of adenoid obstruction in symptomatic children. The clinical score (CS) included mouth breathing, snoring, restless sleep, frequent waking-up at night and obstructive breathing during sleep. Each item received a score of 0 or 1. The palatal airway was evaluated on a lateral nasopharyngeal x-ray. The degree of obstruction was assessed intra-operatively by a laryngeal mirror using a 3-grade scale. The volume of each adenoid specimen was measured. Eighty-six patients were enrolled, 51 boys and 35 girls, aged 13–181 months (mean 52, median 45). The CS correlated very well with the intra-operative findings (p < 0.01) and with the degree of palatal airway obstruction (p < 0.05) but not with the volume of the adenoid removed (p > 0.05). The CS was higher in children younger than 3 years (CS > 3 in 85.7% vs. 29.2%), having more frequent obstructive breathing during sleep (71.43% vs. 21.54%). A CS of three or higher, predicted severe obstruction in 96.5% of patients, as detected intra-operatively. The suggested CS is simple to use and is highly reliable in identifying children in need for adenoidectomy, in the context of normal anterior rhinoscopy and tonsils less than grade three.This work was presented at the podium of the XVIII IFOS in Rome, Italy on June 26, 2005.