Mechanisms of signal change during intraoperative somatosensory evoked potential monitoring of the spinal cord.

In scoliosis surgery, intraoperative somatosensory evoked potential (SSEP) monitoring has reduced the incidence of postoperative neurologic deficits. Many factors affect the amplitude and latency of SSEP waveforms during surgery. Somatosensory evoked potential amplitude decreases with ischemia and anoxia because of temporal dispersion of the afferent volley and conduction block in damaged axons. In conjunction with surgical manipulations, minor drops in blood pressure may result in substantial SSEP changes that reverse when perfusion pressure is increased. Irreversible anoxic injury to central nervous system white matter with loss of SSEP waveforms is dependent on calcium influx into the intracellular space. Somatosensory evoked potential monitoring may be less sensitive for detecting acute insults in the presence of preexisting white matter lesions. Increased extracellular potassium from acute baro-trauma can block axonal conduction transiently even when there is no axonal disruption. Marked temperature-related drops in SSEP amplitude may occur after exposure of the spine but before instrumentation and deformity correction. Hypothermia may increase false-negative outcomes. Short-interval double-pulse stimulation may improve the sensitivity of the SSEP in detecting early ischemic changes. For neurosurgical procedures on the spinal cord the use of SSEP monitoring in improving postoperative outcome is less well established.     

Natural and anthropogenic radioactivity levels and the associated radiation hazard in the soil of Oodalia Tea Estate in the hilly region of Fatickchari in Chittagong,Bangladesh

Radioactivity in the soil of a tea garden in the Fatickchari area in Chittagong, Bangladesh, was measured using a high-resolution HPGe detector. The soil samples were collected from depths of up to 20 cm beneath the soil surface. The activity concentrations of naturally occurring ²³⁸U and ²³²Th were observed to be in the range of 27 ± 7 to 53 ± 8 Bq kg⁻¹ and 36 ± 11 to 72 ± 11 Bq kg⁻¹, respectively. The activity concentration of ⁴⁰K ranged from 201 ± 78 to 672 ± 81 Bq kg⁻¹, and the highest activity of fallout ¹³⁷Cs observed was 10 ± 1 Bq kg⁻¹. The average activity concentration observed for ²³⁸U was 39 ± 8 Bq kg⁻¹, for ²³²Th was 57 ± 11 Bq kg⁻¹, for ⁴⁰K was 384 ± 79 Bq kg⁻¹ and for ¹³⁷Cs was 5 ± 0.5 Bq kg⁻¹. The radiological hazard parameters (representative level index, radium equivalent activity, outdoor and indoor dose rates, outdoor and indoor annual effective dose equivalents, and radiation hazard index) were calculated from the radioactivity in the soil.     

Immunological appraisal of modified gluten to trim down celiac toxicity

The aim of the present research was to modify wheat gluten by binding methionine to gluten proteins to develop bread for celiac disease (CD) patients. The highest protein content, wet gluten content, dry gluten content and sodium dodecyl sulphate-sedimentation value were shown by the wheat variety AARI-11, therefore, it was selected for gluten modification. The bound methionine to gluten proteins was found increasing along the reaction time as the reaction proceeds and at a maximum near to 60 minutes and then it starts decreasing. The lowest immunoreactivity of the modified gluten was obtained near to 60 min of reaction at pH 10. The results for immunoglobulin A (IgA) index showed that the serum of each patient had positive IgA index to gliadins from unmodified gluten, but just sera of two patients had positive IgA index to gliadins from modified gluten and when these proteins were digested, the sera of no patient's serum had positive IgA reactivity. Among physical characteristics of breads 2 hours after baking, the specific volume of the modified gluten containing bread (4.13 ± 0.14 cm³/g) was lower than the control bread (4.59 ± 0.21 cm³/g). However, bread made with modified gluten had higher specific volumes than other gluten-free breads. Texture of the modified gluten was also affected by modification. Finally, the gluten content in the modified gluten bread was 79 ppm which is under the limits set by the Codex Alimentarius for food with reduced gluten content should have from 20 to 100 ppm. The study concludes that the incorporation of steric immensity into gluten proteins in order to shun immune recognition is the most promising approach to acquire wheat-based products that are tolerated by CD patients.     

Influence of vessel diameter on the efficacy of distal protection devices during saphenous vein graft intervention

We sought to determine the influence of vessel diameter on the efficacy of distal protection devices during saphenous vein graft intervention. From the Filterwire EX Randomized Evaluation trial, in which patients who underwent saphenous vein graft stenting were randomized to distal protection with the GuardWire or FilterWire EX, outcomes in 572 patients were examined in vessel size tertiles. The 30-day composite incidence of major adverse cardiac events (MACEs) increased with vessel size and was 6.9%, 9.7%, and 14.9% in the smallest, middle, and largest tertiles, respectively (p = 0.04). MACE rates were relatively vessel size independent for the GuardWire but increased steadily with vessel size with the FilterWire EX. In the smallest tertile, MACEs were reduced by 71% with the FilterWire EX compared with the GuardWire (p = 0.05), with the devices showing similar event rates in the other tertiles.     

Outcomes of endoscopic treatment of gastroduodenal Dieulafoy's lesion with rubber band ligation and thermal/injection therapy

BACKGROUND: Dieulafoy's lesion is a rare but important cause of upper gastrointestinal bleeding. Current endoscopic methods used to treat Dieulafoy's lesion include injection, with or without thermal methods, and mechanical methods. The latter include variceal ligation and hemoclips. There are no studies comparing the outcomes of rubber band ligation and injection with or without thermal therapy. AIM: To report the outcomes of Dieulafoy's lesion treated endoscopically with rubber band ligation and injection with or without thermal therapy at a single institution. METHODS: Patients with the diagnosis of Dieulafoy's lesion treated endoscopically at the Carl T. Hayden VA Medical Center in Phoenix, between August 1994 and August 2002 were analyzed. Demographic data, mode of presentation, risk factors for gastrointestinal bleeding, hemodynamic parameters, blood transfusion requirements, endoscopic findings, details of endoscopic therapy, length of stay in ICU/hospital, complications, recurrence of bleeding, and mortality rates were collected and compared between those receiving endoscopic band ligation (EBL group) and those receiving injection with or without thermal therapy (non-EBL group). RESULTS: Twenty-three patients with Dieulafoy's lesion (14 in the EBL group and nine in the non-EBL group) were studied. All patients were men. The mean age, hemoglobin levels on admission, and the transfusion requirements before therapy were similar in both groups. Fourteen patients (eight in the EBL- and six in the non-EBL groups) presented with hematemesis and the remaining with melena. The majority of Dieulafoy's lesions (91.3%) were located in the stomach and two in the duodenum. Active bleeding at the time of endoscopy was seen in 61% of cases, and immediate hemostasis was achieved with either method in 100% of patients. Early rebleeding (within 72 hours of endoscopic therapy) occurred in only one patient treated with epinephrine plus heater probe therapy. The length of stay in ICU was longer in the non-EBL group (6.7 days) compared with the EBL group (1.8 days) (P = 0.2). There were six deaths (three in the non-EBL group and three in the EBL group) within 30 days of the index hospitalization. The causes of death included infection/sepsis (n = 3), complications of acute myocardial infarction (n = 2), and end-stage liver disease (n = 1). CONCLUSIONS: Endoscopic rubber band ligation is as effective as injection with or without thermal therapy in the treatment of Dieulafoy's lesion.     

Short-term effects of ambient (outdoor) air pollution on cardiovascular death in Tehran,Iran – a time series study

Abstract

The aim of this study was to estimate the effect of ambient air pollutants on cardiovascular deaths in Tehran, Iran. In this time series study, air pollutant data were acquired from the Environmental Protection Agency. Meteorological data were acquired from the meteorological organization, and death data were acquired from the Tehran’s cemetery registration. Generalized Additive Models (GAM) were used for estimating the Rate Ratio. NO₂, SO₂ and PM₁₀ were associated with total cardiovascular deaths. PM₁₀ and NO₂ showed stronger relations with deaths in the elder age group. The result of this study showed that NO_2, SO₂, PM₁₀ and O₃ are probably responsible for part of the cardiovascular deaths that happen daily in Tehran.     

Cognitive neuroscience of hemispatial neglect

Introduction. Patients with neglect often fail to be aware of stimuli located on their contralesional side - the side of space opposite their brain damage. Some patients show impairments in extrapersonal space; others within personal (body) space; and some in both. Although the neglect syndrome may be associated with a distorted perception of extrapersonal or personal space, recent investigations suggest that attentional, memory and motor deficits may be important additional components. Conclusion. Better understanding of these cognitive impairments holds the key to offering effective treatment for neglect, as well as providing important insights into normal brain function.