Comparative analysis of event-related potentials during Go/NoGo and CPT: decomposition of electrophysiological markers of response inhibition and sustained attention

Neuropsychological tests target specific cognitive functions; however, numerous cognitive subcomponents are involved in each test. The aim of this study was to decompose the components of two frontal executive function tests, Go/NoGo (GNG) and cued continuous performance task (CPT), by analyzing event-related potentials (ERPs) of 24 subjects both in time and time-frequency domains. In the time domain, P1, N1, P2, N2 and P3 peak amplitudes and latencies and mean amplitudes of 100 ms time windows of the post-P3 time period were measured. For GNG, the N1 amplitude and for both GNG and CPT N2 amplitudes were significantly higher in the NoGo condition compared with the Go condition. P3 had a central maximum in the NoGo conditions of both paradigms in contrast to a parietal maximum in the Go conditions. All peaks except P1 and mean amplitudes of the post-P3 period were more positive in CPT compared to those of GNG. N1, N2 and P3 latencies were longer for the NoGo condition than the Go condition in the CPT. In time-frequency analyses, the NoGo condition evoked higher theta coefficients than the Go condition, whereas the CPT and GNG paradigms differed mainly in the delta band. These results suggest that theta component reflects response inhibition in both GNG and CPT, whereas delta component reflects the more demanding sustained attention requirement of the CPT. The latency prolongation observed with the NoGo condition of the CPT paradigm was thought to be due to perseverance/inhibition conflict enhanced by the primer stimuli in CPT.     

The midterm results of cardiac transplantation patients

OBJECTIVE: Cardiac transplantation is an important treatment option that increases the survival and decreases the limitations in effort capacity among patients with end-stage heart disease. In this study we have presented the midterm results of 13 patients who underwent cardiac transplantation between 2003 and 2007. PATIENTS AND METHODS: There were 10 male and three female patients of mean age of 32 +/- 13.27 years (12 to 54). In one patient, we performed combined cardiac and renal transplantation. Ischemic cardiac disease was present in six patients and cardiomyopathy in seven patients. The mean age of the donors was 23.3 +/- 11.8 years (12 to 46). Corticosteroids, cyclosporine, and mycophenolate mofetil were used for immunosuppression. Sirolimus was employed in five cases due to impaired renal function. Patients were followed by echocardiography, endomyocardial biopsy, and dobutamine stress echocardiography. RESULTS: The mean follow-up was 18.6 +/- 13.4 (1 to 38) months. In four patients, there was grade IIIA (II-R) rejection. In five patients, tacrolimus or cyclosporine was replaced with sirolimus due to elevated creatinine levels. Dobutamine stress echocardiography was positive in one patient, who displayed a severe left main coronary artery lesion. There was no operative mortality. There was only one hospital mortality (7.6%). Two patients died in the midterm. The overall mortality on follow-up was 3 (23.1%). The survival rates in the first, second, and third years were 92%, 88%, and 75%, respectively. Ejection fraction were more than 50%; all of posttransplant survivors showed good effort capacity. CONCLUSION: Cardiac transplantation is a definitive, safe, and effective treatment for patients with end-stage heart failure.     

Free nerve endings and morphological features of the ligamentum capitis femoris in developmental dysplasia of the hip

A conflict exists on whether the ligamentum capitis femoris has the neuro-morphological structures required for nociception or proprioception of the hip joint. Therefore, we investigated the morphological features and the presence of mechanoreceptors in 24 ligamentum capitis femoris biopsies obtained at open reduction in patients with developmental dysplasia of the hip. Of these 24 hips, 16 were completely dislocated and eight were subluxated. The mean age was 33.8 months (range 13-52 months) at the time of surgery. En bloc ligamentum capitis femoris and pulvinar were taken for biopsy specimen. Ligamentum capitis femoris was dissected and the weight of each ligament was determined using a highly sensitive balance. Specimens were stained with hematoxylin and eosin and Masson trichrome for routine histolopathological evaluation and examined immunohistochemically using monoclonal antibody against S-100 protein. All specimens were graded on a four-grade system according to the amount of coarse-thick collagen bundles and hyalinization. The mean number and type of mechanoreceptors of each specimen were recorded. When the mean age, the patient's weight and the ligamentum capitis femoris weight of each group (completely dislocated vs. subluxated) were compared, there were no significant differences. In the ligamentum capitis femoris of the dislocated hips, the cells were irregularly distributed, had different shapes, and appeared to be in different stages of functional activity. The collagen fiber bundles were thicker than in the subluxated hips, distributed and of varied thickness. The elastic fibers of the dislocated hips were thicker and more numerous than those in the subluxated hips. We found a significant difference between the two groups with regard to the grade of collagen and hyalinization of ligamentum capitis femoris (P<0.004). We found type IVa, free nerve endings in 16 of 24 samples of ligamentum capitis femoris. The 66.6% presence of free nerve endings in the ligamentum capitis femoris suggests a role in nociception/proprioception of the hip in developmental dysplasia of the hip. Interestingly, the percentage and the mean numbers of free nerve endings containing ligamentum capitis femoris were similar in completely dislocated hip group and the subluxated group (62.5 vs. 75%, 12.13+/-9.07 vs. 9.37+/-9.24, respectively). We conclude that the morphological features of ligamentum capitis femoris are influenced by the severity of developmental dysplasia of the hip, whereas the distribution of free nerve endings are not influenced.     

The relationship of Prohepcidin levels with anemia and inflammatory markers in non-diabetic uremic patients: a controlled study

Introduction: Hepcidin, a small peptide hormone synthesized in the liver, plays central role in regulation of iron metabolism. Hepcidin generation in chronic kidney disease (CKD) is dependent on iron status, anemia, inflammation, and hypoxia and erythropoietin levels. In our study, the relationship between Prohepcidin levels and inflammation and iron indices in non-diabetic uremic patients was investigated. Methods: This study has a cross-sectional design which includes four groups: Non-diabetic 21 patients with stage 4 CKD (predialysis), 20 hemodialysis (HD) and 21 peritoneal dialysis (PD) patients and 17 healthy volunteers as the control group. Complete blood count, iron, total iron binding capacity (TIBC), ferritin, high-sensitive C-reactive protein (hsCRP), fibrinogen, parathyroid hormone, interleukin (IL)-6 and Prohepcidin levels were recorded. Results: Serum Prohepcidin levels in the predialysis, HD, PD and the control groups were 119.6?±?45.1?ng/mL, 140.2?±?41.8?ng/mL, 148.2?±?35.0?ng/mL and 93.8?±?21.9?ng/mL, respectively (p?r?=?0.345, p?=?0.002), creatinine (r?=?0.465, p?r?=?0.253, p?=?0.025), hsCRP (r?=?0.275, p?=?0.019), duration of dialysis treatment (r?=?0.443, p?r?=?0.467, p?r?=?0.615, p?r?=??0.286, p?r?=??0.573, p?r?=??0.473, p?r?=??0.351, p?=?0.002) and hematocrit (r?=??0.342, p?=?0.002) levels. Discussion: Prohepcidin levels increase with deepening anemia and show positive correlation with inflammatory markers. Therapeutic interventions regarding Prohepcidin action on inflammatory status may play a role in the treatment of anemia due to inflammation. Functional iron deficiency is frequent in uremic patients. It may be beneficial to measure Prohepcidin level together with ferritin among these patients.     

Emergency thyroidectomy: Due to acute respiratory failure

INTRODUCTION

Giant cervical and mediastinal goiter may lead to acute respiratory failure caused by laryngotracheal compression and airway obstruction. Here, we present a case admitted to the emergency service with a giant goiter along with respiratory failure and poor general health status, which required urgent surgical intervention.

PRESENTATION OF CASE

A 71-year-old female admitted to the emergency room with shortness of breath and poor general health status resulting from a giant cervical swelling progressively increased during the last 7 years and constituted severe respiratory failure which has become severe in the last one month. A giant nodular goiter of the left thyroid lobe extending retrosternally, causing tracheal compression, limiting the neck movements was detected with clinical examination and bedside ultrasound. Emergency thyroidectomy was planned. Fiberoptic-assisted awake nasal intubation was performed in the operating room. Emergency total thyroidectomy was performed for the life-threatening respiratory failure. Postoperative period was uneventful. She was transferred from intensive care unit to the ward on postoperative day 3 and was discharged from the hospital on the postoperative 7th day. Benign multinodular hyperplasia was reported on the histopathological report. Patient was included in routine follow-up.

DISCUSSION

In the present case tracheal destruction due to compression of the giant goiter was found in agreement with previous reports. Emergency thyroidectomy was performed after awake intubation since it is a common surgical option for the treatment of giant goiter causing severe airway obstruction.

CONCLUSION

Respiratory failure due to giant nodular goiter is a life-threatening situation and should be treated immediately by performing awake endotracheal intubation following emergency total thyroidectomy.     

Lipid profiles of patients with a transplanted heart before and after the operation

Background

Graft coronary artery disease, a serious problem after orthotopic heart transplantation (OHT), has multifactorial etiologies with dyslipidemia as one of the major risk factors. In this study we examined lipid profiles and drug therapy of our patients before and after OHT.

Methods

Thirteen patients who underwent OHT at our center were enrolled in the study. We noted the patients’ clinical and demographic data and current medications as well as pre- and postoperative lipid values.

Results

The mean age of the study group was 32.0 ± 13.2 years with three women. Compared to the preoperative values, significant increases were detected in the mean levels of low-density lipoprotein (LDL) (81.3 ± 29.1 vs 103.5 ± 22.2 mg/dL; P = .03) and total cholesterol (142.0 ± 58.5 vs 184.0 ± 37.8 mg/dL; P = .02), while triglyceride (113.5 ± 67.3 vs 137.0 ± 69.9 mg/dL; P = .1) and high-density lipoprotein (42.7 ± 10.2 vs 48.7 ± 14.4 mg/dL; P = .2) levels did not change significantly at 2 to 3 months postoperatively. On follow-up eight patients were prescribed a statin (atorvastatin in all), one of whom was on ezetimibe in addition to statin and one, fenofibrate. The patients tolerated lipid-lowering agents well; no significant side effect was noted.

Conclusion

These findings demonstrated increased lipid values, mainly in total cholesterol and LDL levels, after OHT. Regarding the importance of dyslipidemia as a major atherosclerotic risk factor, we believe that statins in the absence of a contraindication should be part of the treatment protocol in patients with a transplanted heart.     

Impact of surgical treatment on respiratory muscle dysfunction in symptomatic hyperparathyroidism

HYPOTHESIS: We hypothesized that surgical treatment would improve respiratory muscle strength in symptomatic hyperparathyroidism (HPT). DESIGN: Prospective clinical trial. SETTING: A tertiary referral center. PATIENTS: Fifteen consecutive patients with symptomatic HPT and 10 with euthyroid multinodular goiter (control group) without a history of obstructive or restrictive lung disease. INTERVENTIONS: Forced vital capacity and forced expiratory volume in 1 second were measured before and 6 months after surgery to estimate respiratory muscle involvement. These measurements were compared with the reference values estimated individually in each patient. Mann-Whitney and Wilcoxon signed rank tests were used for statistical analysis, and P<.05 was considered statistically significant. MAIN OUTCOME MEASURES: Respiratory dysfunction in patients with symptomatic HPT, pulmonary function after parathyroidectomy, and the correlation between the preoperative serum parathyroid hormone and total serum calcium values and the impairment in pulmonary function. RESULTS: Preoperative forced vital capacity and forced expiratory volume in 1 second measurements were below the reference values in 11 (73%) and 9 (60%) patients, respectively. All the patients were normocalcemic, and forced vital capacity and forced expiratory volume in 1 second measurements significantly improved at postoperative month 6 (P = .001). No significant difference was detected in the control group. Improvement in pulmonary function correlated with preoperative serum calcium and parathyroid hormone values in patients with HPT (P<.05 and P<.001, respectively). CONCLUSIONS: Symptomatic HPT impairs inspiratory and expiratory components of respiratory function, and normalization of serum calcium levels after surgical treatment is associated with a significant improvement in lung function.     

Apoptosis and Proliferation of Cardiomyocytes and Interstitial Mononuclear Cells: Association With Rejection and Macrophage Infiltration

Previous studies have noted that acute rejection episodes (AREs) may lead to loss of cardiomyocytes in transplanted hearts. The aim of this study was twofold; first, to assess the degree of apoptotic cells and to compute the proliferation index of cardiomyocytes and mononuclear interstitial infiltrates in cardiac allografts. Second, we sought to determine whether apoptosis involved in AREs was associated with macrophage infiltration. Among 28 endomyocardial biopsies, 18 showed AREs and the remaining 10 biopsies, nonspecific changes, the control group. All biopsies were immunostained with Ki-67 and CD68 antibodies. Apoptotic cells were counted using the terminal deoxyncleotidyl transferase dUTP nick end labeling method. Apoptotic death of cardiac myocytes and interstitial mononuclear cells was significantly greater in cases of allograft rejection compared with the control group (P < .05). In addition, compared to the control group, ARE cases showed a greater proliferation index of cardiac myocytes and interstitial cells (P < .05). Macrophage infiltration was significantly greater in ARE cases and macrophage infiltration showed a linear association with both apoptosis and proliferation of myocytes and interstitial cells (P < .001). In conclusion, we verified the presence of apoptotic cell death during acute rejection in heart transplants. Apoptotic cell death was significant among interstitial cells but it was less among cardiac myocytes. Macrophage infiltration had a great influence on apoptotic cell death of myocytes and interstitial cells.