GFRα-1 is expressed in parvalbumin GABAergic neurons in the hippocampus

Glial cell line derived neurotrophic factor (GDNF) is a potent survival factor for several types of neurons. GDNF binds with high affinity to GDNF-family receptor α-1 (GFRα-1). This receptor is expressed in different areas of the brain, including the hippocampus and dentate gyrus. By using in situ hybridization and immunohistochemistry, we found that 19% to 37% of glutamic acid decarboxylase (GAD) expressing neurons co-expressed GFRα-1 in the hippocampus. GFRα-1/GAD co-expression was found mainly in the stratum (s) pyramidale (29–37%) and s. oriens (20–25%). Further characterization of GFRα-1 expressing interneurons, based on their calcium-binding protein immunoreactivity, demonstrated that many parvalbumin (PV) immunoreactive neurons express GFRα-1 in the s. pyramidale of CA1 (72%), CA2 (70%) and CA3 (70%) subfields of the hippocampus. GFRα-1/PV double labeled neurons were also detected in the s. oriens of CA1 (52%), CA2 (27%) and CA3 (36%) subfields. The expression of GFRα-1 in principal neurons and in a specific sub-population of GABAergic neurons (PV-containing neurons) suggest that GDNF might modulate, in a selective manner, functions of the entire adult hippocampus.     

Polymorphisms of genes encoding interleukin-4 and its receptor in Iranian patients with juvenile idiopathic arthritis

As cytokines, including interleukin-4 (IL-4), seem to have a pivotal role in the pathogenesis of juvenile idiopathic arthritis (JIA), this study is aimed at investigating of association of polymorphisms in IL-4 and IL-4 receptor α (IL-4RA) genes with susceptibility to JIA. A case-control study was conducted on 53 patients with JIA and 139 healthy unrelated controls. Single nucleotide polymorphisms of IL-4 gene at positions -1098, -590, and -33, as well as IL-4RA gene at position +1902 were genotyped using polymerase chain reaction with sequence-specific primers method and compared between patients and healthy individuals. At the allelic level, C allele at IL-4 -33 was found to be more frequent in patients compared to control (P value <0.01). At the genotypic level, CC genotype at IL-4 -590 (P value <0.01), together with CC and TT genotypes at IL-4 -33 (P value <0.01), were significantly higher in patients with JIA, while TC genotypes at IL-4 -590 and -33 positions were found to be lower in case group (P value <0.01). At the haplotypic level, IL-4 (positions -1098, -509, -33) TTC, GCC, and TTT haplotypes were significantly lower than controls (P value <0.01, P value?=?0.03, and P value?=?0.04, respectively). Although, TCC haplotype at the same positions was found to be higher in patients (P value <0.01). Polymorphic site of +1902 IL-4RA gene did not differ between cases and controls. Polymorphisms in promoter region of IL-4 but not IL-4RA genes confer susceptibility to JIA and may predispose individuals to adaptive immune responses.     

Prognostic value of positive T wave in lead aVR in patients with non‐ST segment myocardial infarction

Background

Lead aVR provides prognostic information in various settings in patients with ischemia. We aim to investigate the role of a positive T wave in lead aVR in non‐ST segment myocardial infarction (NSTEMI).

Methods

In a prospective cohort study, we included 400 patients with NSTEMI. Presentation electrocardiogram (ECG) was investigated for presence of a positive T wave as well as ST segment elevation (STE) in aVR and study variables were compared. Predictors of primary outcome defined as hospital major adverse cardiovascular events (MACE) and secondary outcome, defined as three‐vessel coronary disease and/or left main coronary artery stenosis (3VD/LMCA) stenosis in angiography, were determined in multivariate logistic regression analysis.

Results

Patients with a positive T wave in aVR were significantly older and were more likely to be female. Left ventricular ejection fraction was significantly lower in patients of positive T group. Positive T group was more likely to have 3VD/LMCA stenosis (58.3% vs. 19.8%, p < .001). The prevalence of a positive T wave in aVR was significantly higher in MACE group (54.9 % vs. 24.8%, p < .001). However, in multivariate analysis, it was not an independent predictor of MACE (OR: 1.083 95% CI: [0.496–2.365], p: .841). Though, it was independently associated with presence of 3VD/LMCA stenosis (OR: 3.747 95% CI: [2.058–6.822], p < .001).

Conclusion

Though positive T wave in lead aVR was more common in patients with MACE; it was not an independent predictor. Additionally, a positive T wave in aVR was an independent predictor of 3VD/LMCA stenosis in NSTEMI.

     

Physicochemical characterization and optimization of glycolipid biosurfactant production by a native strain of Pseudomonas aeruginosa HAK01 and its performance evaluation for the MEOR process

In this study, a glycolipid type of biosurfactant (BS) was produced, its characteristics were evaluated and several flooding tests were conducted in a micromodel to investigate its potential for enhancing oil recovery. A rhamnolipid BS producer strain was identified as a bacterium belonging to the genus Pseudomonas aeruginosa. This BS showed good stability at temperatures of 40–121 °C, pH values of 3–10 and salinity up to 10% (w/v) NaCl which is important in Microbial Enhanced Oil Recovery (MEOR). The rhamnolipid decreased the surface tension of water from 72 to 28.1 mN m⁻¹ with a critical micelle concentration of 120 ppm. Thin layer chromatography, FTIR spectroscopy, ¹H-NMR and ¹³C-NMR spectroscopy revealed the glycolipid structure of the BS. Response surface methodology was applied to optimize BS production. Several micromodel flooding tests were conducted to study the capability of the produced rhamnolipid in enhanced oil recovery for the first time. An oil recovery factor of 43% was obtained at 120 ppm of BS solution whereas the recovery factor obtained for water flooding was 16%. Contact angle measurements showed that BS solutions altered the wettability of a glass surface from oil wet to a strongly water wet state. Also the results illustrated that all BS solutions were impressive in microbial enhanced oil recovery (MEOR) and using the produced BS a considerable amount of trapped oil can be extracted due to interfacial tension reduction, wettability alteration towards water wet conditions and improving the mobility ratio.

In this study, a glycolipid type of biosurfactant (BS) was produced, its characteristics were evaluated and several flooding tests were conducted in a micromodel to investigate its potential for enhancing oil recovery.     

County Versus Private Hospitals: Access of Care, Management and Outcomes for Patients with Appendicitis

Background and Objectives:

Race/ethnicity and socioeconomic status may affect healthcare access (higher appendiceal perforation [AP] rates), management (lower laparoscopic appendectomy [LA] rates), and outcomes in patients with appendicitis. This study determines if disparities exist between county and private hospitals.

Methods:

A review of patients ≥18 years treated for appendicitis from 1998 through 2007 was performed. Data from a county hospital were compared to data from 12 private hospitals. Study outcomes included length of hospitalization (LOH), and rates of AP, LA, and abscess drainage. Predictor variables collected included age, sex, race/ethnicity, per-capita income, and hospital type.

Results:

For this study, 16,512 patients were identified (county=1,293, private=15,219). On univariate analysis, patients at the county hospital had lower mean per-capita incomes ($13,412 vs. $17,584, P<.0001), similar AP rates at presentation (26% vs. 24%, P=.10), and lower abscess drainage (0.2% vs. 2.1%, P<.0001). However, multivariate analysis demonstrated a higher AP (OR 1.4, CI 1.2–1.6) and LA rate (OR 1.9, CI 1.7–2.2), a lower abscess drainage rate (0.07, 95%CI 0.02–0.27), and longer LOH (parameter estimate = 0.4, P<.0001) at the county hospital. Within the county hospital cohort, LOH and rates of AP, LA, and abscess drainage were similar across all races/ethnicities and income levels.

Conclusions:

When compared to private hospital patients, adults with appendicitis treated at a county hospital were of lower socioeconomic background, had higher AP rates and longer LOH, but were more likely to undergo LA and less likely to require abscess drainage. Since racial and socioeconomic disparities were no longer apparent once within the county hospital cohort, these differences may be due to differences in access to healthcare.     

Noniatrogenic Aneurysm of the Distal Radial Artery: A Case Report

Radial artery aneurysms are extremely rare. The majority are traumatic in origin and are iatrogenic pseudoaneurysms following arterial cannulation. We present an unusual case of an idiopathic isolated aneurysm of the most distal portion of the radial artery. Interestingly, upon performance of the Allen test, it was determined that the majority of blood flow to the hand was derived from the aneurysmal artery. Arteriography showed an occluded ulnar artery, a tortuous superficial palmar arch and absent deep palmar arch, and multiple small vessels that arose from the aneurysm that supplied the thumb. Given these findings, it was determined that there would be a significant risk of digital ischemia and gangrene if operative repair was attempted. A course of nonoperative management with observation was recommended.     

The 80-hour resident workweek does not adversely affect patient outcomes or resident education

PURPOSE: To determine whether the 80-hour resident workweek adversely affects patient outcomes or resident education. METHODS: To assess patient outcomes, the authors reviewed trauma patient morbidity and mortality at the second busiest level I trauma center in Los Angeles County before (July 1998-June 2003, Period 1) and after (July 2003-June 2005, Period 2) implementation of the duty hour limitation via a retrospective review of a prospective database. All patients were operated and managed by residents under faculty supervision. Patient characteristics included the injury severity score (ISS), mechanism of injury, complications, and death. To assess resident education, the authors compared ABSITE percentile scores, first-time pass rates on the American Board of Surgery Qualifying and Certifying Examinations, and total and chief resident operative case volumes. In addition, they estimated institutional costs incurred to comply with the new duty hour rules. RESULTS: Patient outcomes. Over the entire 7-year study period, 11,518 trauma patients were transported to Harbor-UCLA Medical Center. Compared with Period 1, Period 2 experienced an increase in average yearly patient volume from 1510 to 1981 (p 0.01). The average ISS also increased, from 7.9 to 9.6 (p < 0.0001), as did the proportion of penetrating trauma from 14.8% to 17.6% (p < 0.0001). Morbidity and mortality rates remained unchanged. Resident education. Mean ABSITE scores and first-time Qualifying and Certifying Exam pass rates were unchanged. Mean resident total major case volumes increased significantly in Period 2 from 831 to 1156 (p < 0.0001), whereas chief resident year case volumes were unchanged. The estimated cost incurred by this institution to conform to the new work hour standards was approximately 359,000 dollars per year. CONCLUSIONS: Despite concerns that the 80-hour workweek might threaten patient care and resident education, the morbidity and mortality rates at a busy level I trauma center remained unchanged. The quality of surgical resident education, as measured by operative volumes, ABSITE scores, and written and oral board examination pass rates were likewise unchanged. The reorganization of the authors' general surgery residency program to comply with the duty hour restrictions was achieved within reasonable cost.     

Comparison of select cancer biomarkers in human circulating and bulk tumor cells using magnetic nanoparticles and a miniaturized micro-NMR system

Circulating tumor cells (CTC) harvested from peripheral blood have received significant interest as sources for serial sampling to gauge treatment efficacy. Nanotechnology and microfluidic based approaches are emerging to facilitate such analyses. While of considerable clinical importance, there is little information on how similar or different CTCs are from their shedding bulk tumors. In this clinical study, paired tumor fine needle aspirate and peripheral blood samples were obtained from cancer patients during image-guided biopsy. Using targeted magnetic nanoparticles and a point-of-care micro-NMR system, we compared selected biomarkers (EpCAM, EGFR, HER-2 and vimentin) in both CTC and fine needle biopsies of solid epithelial cancers. We show a weak correlation between each paired sample, suggesting that use of CTC as “liquid biopsies” and proxies to metastatic solid lesions could be misleading.From the Clinical EditorIn this clinical study, paired tumor fine needle aspirate and peripheral blood samples were obtained from patients with solid epithelial cancers during image-guided biopsy. Using targeted magnetic nanoparticles and a point-of-care micro-NMR system, the authors compared selected biomarkers in both circulating tumor cells (CTC) and fine needle biopsies, demonstrating a weak correlation between each paired sample, suggesting that use of CTC could be misleading in this context.