Symptoms, acid exposure and motility in patients with Barrett's esophagus.

INTRODUCTION: Barrett's esophagus, a syndrome in which the squamous mucosa that normally lines the distal esophagus is replaced with columnar epithelium, is found in a small percentage of patients presenting with gastroesophageal reflux disease (GERD). The columnar epithelium may be protective, guarding people afflicted with Barrett's esophagus from experiencing symptoms related to acid reflux. The purpose of this study was to investigate whether people with Barrett's esophagus subjectively experience fewer symptoms or symptoms of decreased severity, despite sustaining greater acid exposure, than those with GERD but without Barrett's syndrome. METHODS: We conducted a chart review of patients with GERD. Criteria for inclusion in the study were esophagogastroscopy, motility testing and a 24-hour pH study. Fifty-eight patients (29 men, 29 women) fulfilled these criteria. The diagnosis of GERD was based on an abnormal 24-hour pH study (DeMeester score). Of these 58 patients, 21 (14 men, 7 women) were found to have histologically confirmed Barrett's esophagus. A questionnaire to assess the key symptoms of GERD was administered, with a severity score ranging from 0 to 3 (3 being the most severe) for each symptom. RESULTS: Patients with Barrett's esophagus experienced symptoms significantly less severe (p < 0.01) than those with GERD. Patients with Barrett's esophagus also had a greater degree of acid exposure as identified by higher DeMeester scores (p = 0.056), longer episodes of acid exposure, a greater number of long episodes (> 5 min) of acid exposure (p = 0.033) and an increased percentage of time when their pH was less than 4. Patients with Barrett's esophagus had decreased resting lower esophageal sphincter tone, and number and amplitude of peristaltic contractions. CONCLUSIONS: For patients with Barrett's esophagus, the columnar epithelium may serve a protective function in guarding against symptoms of acid reflux. This has implications for the diagnosis and management of this condition.     

An assessment of the characteristics of n-type diodes for use in electron beam radiotherapy.

Diodes are now commercially available for use in electron beams. This paper aims to assess their response and limitations under different clinical conditions. Parameters considered were applicator factors, focus skin distance (FSD), angle of incidence, and temperature dependence. The beam perturbation was also measured. The beam energies used varied from 5 to 17 MeV. Applicator factors, measured at the surface of a phantom, differed by up to 7% compared with ion chamber measurements at Dmax. Similarly, large differences were found in FSD dependence. The temperature dependence was found to be approximately double the manufacturer's specification at 0.7% per degree Centigrade and the angular dependence was within the specification of +/- 2% for angles of +/- 30 degrees. The beam perturbation was measured as a maximum of 25% for 5-MeV electrons. The measurements were compared to other published data but this is highly dependent on the methodology employed. It was concluded that the diodes could be used in some circumstances, but only if used with extreme caution. An extensive set of commissioning measurements would be required before introducing the diodes into use clinically.     

Genetic contributions to Parkinson's disease

Sporadic Parkinson's disease (PD) is a common neurodegenerative disorder, characterized by the loss of midbrain dopamine neurons and Lewy body inclusions. It is thought to result from a complex interaction between multiple predisposing genes and environmental influences, although these interactions are still poorly understood. Several causative genes have been identified in different families. Mutations in two genes [α-synuclein and nuclear receptor-related 1 (Nurr1)] cause the same pathology, and a third locus on chromosome 2 also causes this pathology. Other familial PD mutations have identified genes involved in the ubiquitin–proteasome system [parkin and ubiquitin C-terminal hydroxylase L1 (UCHL1)], although such cases do not produce Lewy bodies. These studies highlight critical cellular proteins and mechanisms for dopamine neuron survival as disrupted in Parkinson's disease. Understanding the genetic variations impacting on dopamine neurons may illuminate other molecular mechanisms involved. Additional candidate genes involved in dopamine cell survival, dopamine synthesis, metabolism and function, energy supply, oxidative stress, and cellular detoxification have been indicated by transgenic animal models and/or screened in human populations with differing results. Genetic variation in genes known to produce different patterns and types of neurodegeneration that may impact on the function of dopamine neurons are also reviewed. These studies suggest that environment and genetic background are likely to have a significant influence on susceptibility to Parkinson's disease. The identification of multiple genes predisposing to Parkinson's disease will assist in determining the cellular pathway/s leading to the neurodegeneration observed in this disease.     

ERP evidence of impaired central nervous system function in virally suppressed HIV patients on antiretroviral therapy.

OBJECTIVE: To examine the effects of human immunodeficiency virus (HIV) on central nervous system (CNS) function in patients receiving antiretroviral therapy (ART) who have suppressed viral loads. METHODS: Event-related brain potentials (ERPs) were recorded from 15 virally suppressed HIV patients and 15 age-, sex-, and education-matched controls while they performed a 3-stimulus auditory oddball task. The amplitude and latency of the P3a, P3b, and early auditory components were examined in HIV patients and controls. RESULTS: Virally suppressed HIV patients on ART were more depressed than controls, as determined by the Beck Depression Inventory (BDI). After controlling for the effects of depression, HIV patients had smaller P2, P3a, and P3b amplitudes and longer P3a and P3b latency than control subjects. BDI scores correlated positively with N1 latency in HIV patients and negatively with P3b amplitude in all subjects. CONCLUSIONS: These electrophysiological results suggest that, even in the absence of detectable levels of HIV in the peripheral blood, viral replication persists in the CNS and continues to cause disease in HIV patients on ART.     

Pseudo-outbreak of Acinetobacter lwoffii infection in a tertiary care center in Thailand.

We describe a pseudo-outbreak of Acinetobacter lwoffii infection that was recognized early. The pseudo-outbreak involved 16 patients and occurred 3.5 months after the GNS-506 Vitek automated system was introduced in the microbiology laboratory. Prompt confirmation of incomplete use of the automated system's algorithm as the point source of the misidentified A. lwoffii clinical isolates averted a full outbreak investigation and excess use of infection control resources.     

Medical imaging of fetal ventriculomegaly

Five cases of fetal ventriculomegaly are described in detail. Following ultrasonography, either computerized tomography or magnetic resonance imaging was used in an attempt to clarify the structural pathology of the ventriculomegaly. In two patients, a precise diagnosis was achieved while a probable diagnosis was established in a third patient. The diverse etiology of fetal ventriculomegaly in these five cases demonstrates that ancillary medical imaging may be necessary to achieve diagnostic precision prior to therapeutic intervention.     

Mitigation of hearing loss from semi-circular canal transection in pseudomonas otitis media with ciprofloxacin-dexamethasone irrigation.

HYPOTHESIS: Irrigation of the mastoid with a quinolone antibiotic-steroid solution may mitigate hearing loss caused by iatrogenic semicircular canal injury in the presence of Pseudomonas aeruginosa (PA) otitis media (OM). BACKGROUND: Studies have shown the cochlea to be more vulnerable to semicircular canal transection (SCT)-related hearing loss in the presence of PA OM. Prophylactic systemic antibiotics and steroids may decrease this hearing loss, but SCT is usually not planned. The aim of this study was to determine if irrigation with ciprofloxacin-dexamethasone (cipro-dex) could improve hearing outcomes following SCT in PA OM. METHODS: PA OM was induced in 28 animals. After three to five days, unilateral SCT was performed in each animal, with sham SCT on the contralateral ear. At surgery, half of the animals (n = 14) underwent irrigation of the both mastoid bullae with cipro-dex; the second group of animals (n = 14) underwent irrigation of the bullae with sterile saline. Auditory thresholds were obtained immediately prior to SCT and 7-10 days after SCT. RESULTS: SCT ears treated with cipro-dex showed a mean click threshold improvement of 4.6 dB from pre-transection to 7-10 days post-transection, whereas thresholds in the SCT ears treated with saline worsened by 7.5 dB (p = 0.15). CONCLUSION: Irrigation of the guinea pig bulla with cipro-dex following SCT in the setting of PA OM appears safe and may yield beneficial effects on hearing.