Neural correlates of retrieval success and precision: an fMRI study.

Prior studies examining the neural mechanisms underlying retrieval success and precision have yielded inconsistent results. Here, their neural correlates were examined using a memory task that assessed precision for spatial location. A sample of healthy young adults underwent fMRI scanning during a single study-test cycle. At study, participants viewed a series of object images, each placed at a randomly selected location on an imaginary circle. At test, studied images were intermixed with new images and presented to the participants. The requirement was to move a cursor to the location of the studied image, guessing if necessary. Participants then signaled whether the presented image as having been studied. Memory precision was quantified as the angle between the studied location and the location selected by the participant. A precision effect was evident in the left angular gyrus, where BOLD activity covaried across trials with location accuracy. Multi-voxel pattern analysis also revealed a significant item-level reinstatement effect for high-precision trials. There was no evidence of a retrieval success effect in the angular gyrus. BOLD activity in the hippocampus was insensitive to both success and precision. These findings are partially consistent with prior evidence that success and precision are dissociable features of memory retrieval.

The Role of Radionuclide Imaging in Brain Death Diagnosis.

Brain death is defined as the complete and irreversible cessation of the entire brain function, including the brainstem. For the most part, the diagnosis is clinical, and ancillary testing is only needed when clinical criteria are not satisfied. Differences exist in brain death diagnosis policy in the confirmation of brain death with ancillary testing and the particular test used. Demonstration of the absence of cerebral circulation is a reliable indicator of brain death. Currently, there are no agreed-on universal criteria for ancillary imaging investigation. However, several guidelines and meta-analyses have referred to radionuclide imaging as the most reliable, accurate, and validated ancillary imaging procedure in the confirmation of brain death. Whenever available, lipophilic agents should be preferred using tomographic imaging in all or as needed. False results may occur because of slight temporal delays in flow-function interaction, and such findings may carry prognostic information. Detectable cerebral circulation in the clinical presence of brain death most probably indicates that the process of dying is not yet complete. The results of radionuclide studies may also suggest that the loss of viability in a significant proportion of brain tissue is not compatible with life.

Perceptions of adult intensive care unit patients regarding nursing presence and their intensive care experiences: A descriptive-correlational study.

AIMS AND OBJECTIVES: This study aims to determine the relationship between perceptions of nursing presence and intensive care experiences in adult intensive care unit patients'. BACKGROUND: Intensive care units (ICUs) are settings where patients have many negative emotions and experiences, which affect both treatment and post-discharge outcomes. The holistic presence of nurses may help patients turn their negative emotions and experiences into positive ones. DESIGN: A descriptive-correlational design was used and reported according to the STROBE checklist. METHODS: The sample consisted of 182 participants. Data were collected using a personal information form, the Glasgow Coma Scale (GCS), the Intensive Care Experience Scale (ICES), and the Presence of Nursing Scale (PONS). RESULTS: A strong positive correlation existed between total ICES and PONS scores (r = 0.889, p < 0.001). There was a strong positive correlation between PONS total score and ICES subscales (awareness of surroundings (r = 0.751, p < 0.001), frightening experiences (r = 0.770, p < 0.001), recall of experience (r = 0.774, p < 0.001), and satisfaction with care (r = 0.746, p < 0.001)). Males (ß = -0.139, p < 0.05), and patients who were university and higher education graduate (ß = 0.137, p < 0.05) had higher positive ICU experiences. It was also found length of ICU stay was correlated with ICU experiences and nursing presence. CONCLUSIONS: The more positively the patients perceive nurses, the better ICU experiences they have. Gender and education level were found determinants of adult ICU patients' experiences. ICU length of stay predicted what kind of experience patients have and how much they feel the presence of nurses. RELEVANCE TO CLINICAL PRACTICE: Nurses should make their presence felt completely and holistically by using their communication skills for patients have more positive intensive care experiences. Nurses should consider variables which affects patients' ICU experiences and nursing presence.

Evaluation of the quality and content of YouTube videos as an educational resource in developing patients' inhaler use skills.

BACKGROUND: YouTube has educational videos on inhalers. However, their content and quality are not adequately known. OBJECTIVES: This study investigated the quality and content of educational YouTube videos on inhalers. METHODS: This descriptive study analyzed 178 YouTube videos on inhalers between May and July 2022. Two researchers independently evaluated the videos. The Global Quality Score (GQS), Journal of American Medical Association (JAMA) Benchmark Criteria, and Inhaler Application Checklist (IAC) were used to assess the quality and content of the videos. Spearman's correlation, Kruskal-Wallis, Mann-Whitney U, ANOVA, and Post hoc analysis Bonferroni test were used for data analysis. RESULTS: The videos had a mean GQS score of 3.70 ± 1.24, and JAMA score of 2.22 ± 0.60. A negative correlation was between the quality score of the videos and views, likes, comments, duration, and likes/views (respectively; r = -0.237 p < 0.005, r = -0.217 p < 0.003, r = -0.220 p < 0.005, r = -0.147, p < 0.005). The videos narrated by nurses and doctors had significantly higher mean JAMA and GQS scores than others (p = 0.001). The videos missed some procedural steps [gargling (29.1%), adding no more than five ml of medication and device cleaning (41.9%), and exhaling through the nose (37.5%)]. Videos uploaded by individual missed significantly more procedural steps than professional organizations (p < 0.05). CONCLUSIONS: YouTube videos about inhaler techniques have a moderate level of quality. Videos uploaded by doctors and nurses as content narrators were of higher quality. The videos missed some procedural steps. Individual video uploaders had higher missed procedural steps. Counseling should be provided to patients regarding the reliability of online information.

Evaluation of Imaging Findings in Patients with Pretransplant and Posttransplant Tertiary Hyperparathyroidism.

OBJECTIVES: Tertiary hyperparathyroidism, characterized by autonomous overproduction of parathyroid hormone, can be seen in patients with long-standing secondary hyperparathyroidism (pretransplant) or after renal transplant (posttransplant). Parathyroid scintigraphy and ultrasonography are the most commonly used imaging procedures for the preoperative localization of abnormal parathyroid glands. We aimed to evaluate imaging findings in pretransplant and posttransplant tertiary hyperparathyroidism. MATERIALS AND METHODS: This study included 32 patients with pretransplant tertiary hyperparathyroidism and 20 patients with posttransplant tertiary hyperparathyroidism. On parathyroid scintigraphy with technetium-99m sestamibi, early-phase and latephase images were acquired. Images were evaluated for the presence and the number of active foci and the degree of uptake on the late-phase image. The existence of an autonomous gland was based on latephase retention and was scored from 0 to 2 (retention score). On ultrasonography, the criteria threshold for autonomy was the maximum length of the largest gland ≥10 mm (ultrasonography score). RESULTS: On parathyroid scintigraphy, the most commonly observed pattern in the pretransplant group was positivity in ≥3 glands, and in the posttransplant group the most commonly observed pattern was positivity in 1 to 2 glands. In pretransplant and posttransplant groups, the criteria threshold for the presence of an autonomous parathyroid gland on parathyroid scintigraphy (grade 2 retention) was met in 26 (81%) and 9 (45%) patients and on ultrasonography in 25 (78%) and 10 (50%) patients, respectively. In the whole group of patients (n = 52), correlation existed between ultrasonography score and retention score. Glandular weight was correlated with both retention score and ultrasonography score. CONCLUSIONS: Higher numbers of detectable glands and the presence of parathyroid autonomy were more common in the pretransplant group. This might be explained by parathyroid gland involution after transplant. The results may also suggest that factors other than autonomy are responsible for posttransplant tertiary hyperparathyroidism.

Dissociative Effects of Age on Neural Differentiation at the Category and Item Levels.

Increasing age is associated with age-related neural dedifferentiation, a reduction in the selectivity of neural representations, which has been proposed to contribute to cognitive decline in older age. Recent findings indicate that when operationalized in terms of selectivity for different perceptual categories, age-related neural dedifferentiation and the apparent age-invariant association of neural selectivity with cognitive performance are largely restricted to the cortical regions typically recruited during scene processing. It is currently unknown whether this category-level dissociation extends to metrics of neural selectivity defined at the level of individual stimulus items. Here, we examined neural selectivity at the category and item levels using multivoxel pattern similarity analysis (PSA) of fMRI data. Healthy young and older male and female adults viewed images of objects and scenes. Some items were presented singly, while others were either repeated or followed by a "similar lure." In agreement with recent findings, category-level PSA revealed robustly lower differentiation in older than in younger adults in scene-selective, but not object-selective, cortical regions. By contrast, at the item level, robust age-related declines in neural differentiation were evident for both stimulus categories. Additionally, we identified an age-invariant association between category-level scene selectivity in the parahippocampal place area and subsequent memory performance, but no such association was evident for item-level metrics. Lastly, category- and item-level neural metrics were uncorrelated. Thus, the present findings suggest that age-related category- and item-level dedifferentiation depend on distinct neural mechanisms.

The Association of Serum Uric Acid Levels and Various Uric Acid-Related Ratios with Insulin Resistance and Obesity: A Preliminary Study in Adolescents.

BACKGROUND: Studies have shown that serum uric acid levels and uric acid-related ratios, such as uric acid-to-albumin ratio (UAR), uric acid-to-creatinine ratio (UCR), uric acid-to-high-density lipoprotein cholesterol (HDL cholesterol) ratio (UHR), and uric acid-to-lymphocyte ratio (ULR), are associated with various diseases and their complications, and that these ratios can be used as biomarkers. In the current study, we aimed to investigate uric acid levels in obese adolescents and the relationship of uric acid-related ratios with insulin resistance and obesity for the first time in the literature. METHODS: A total of 100 adolescents (60 obese and 40 healthy) aged 10-17 years were retrospectively included. Participants were assigned to two groups: the obese group and the healthy control group. Obesity was defined as a body mass index (BMI) >the 95th percentile for age and gender. Demographic and laboratory data (serum glucose, urea, creatinine, uric acid, albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), C-reactive protein (CRP), total cholesterol, triglyceride, HDL cholesterol, thyroid-stimulating hormone (TSH), free T4 (fT4), insulin levels, and complete blood count) were obtained from the laboratory information management system. A homeostatic model of assessment for insulin resistance (HOMA-IR), low-density lipoprotein cholesterol (LDL cholesterol), and uric acid-related ratios were calculated. RESULTS: Uric acid, UAR, UCR, and UHR levels of obese adolescents were significantly higher than the healthy group (p < 0.05). We found that HOMA-IR was positively correlated with uric acid, UAR, and UHR. No correlation was found between BMI and uric acid or uric acid-related ratios. We did not find any difference between the two groups in terms of ULR levels, and we did not find any correlation between BMI and HOMA-IR. CONCLUSION: High levels of serum uric acid, UAR, UCR, and UHR were associated with obesity. Furthermore, we found that uric acid, UAR, and UHR were positively correlated with insulin resistance.

Comparison of parathyroid scintigraphy findings in pediatric and adult patients with secondary hyperparathyroidism.

OBJECTIVES: Secondary hyperparathyroidism (sHPT) is a compensatory complication of chronic kidney disease. The aim of this study was to compare PS findings in pediatric and adult patients with sHPT. METHODS: This study included 50 pediatric and 50 adult patients with sHPT. Parathyroid scintigraphy was performed with Tc-99m sestamibi. After radiopharmaceutical injection, early-phase (15 min) and late-phase (60-90 min) images were acquired. Planar images were interpreted visually for the presence / number of active foci compatible with a parathyroid lesion, the presence and degree of uptake in skeletal structures, and the degree of thyroid sestamibi uptake. Parathyroid surgery was performed in 21 pediatric and 28 adult patients. RESULTS: Serum PTH and ALP values were significantly higher in pediatric than in adult patients ( P < 0.05 for each). In operated patients, on a lesion-based analysis, the sensitivity of PS in pediatric and adult patients were 40% and 71%, respectively. A nonlocalizing scan was observed in 24% of pediatric patients. Pediatric patients had a higher incidence of reduced thyroid sestamibi uptake (42% versus 2%). Skeletal sestamibi uptake was detected in 40% of pediatric and 30% of adult patients and the degree of uptake was higher in pediatric patients. CONCLUSIONS: The results revealed more significant changes in the biochemical profile of pediatric compared with adult patients with sHPT. The sensitivity of PS was lower, and the likelihood of a nonlocalizing scan was higher in pediatric patients. The results may also suggest more severe skeletal findings in pediatric patients. Reduced thyroid sestamibi uptake in children needs further evaluation.

Dissociative effects of age on neural differentiation at the category and item level.

Increasing age is associated with age-related neural dedifferentiation, a reduction in the selectivity of neural representations which has been proposed to contribute to cognitive decline in older age. Recent findings indicate that when operationalized in terms of selectivity for different perceptual categories, age-related neural dedifferentiation, and the apparent age-invariant association of neural selectivity with cognitive performance, are largely restricted to the cortical regions typically recruited during scene processing. It is currently unknown whether this category-level dissociation extends to metrics of neural selectivity defined at the level of individual stimulus items. Here, we examined neural selectivity at the category and item levels using multivoxel pattern similarity analysis (PSA) of fMRI data. Healthy young and older male and female adults viewed images of objects and scenes. Some items were presented singly, while others were either repeated or followed by a 'similar lure'. Consistent with recent findings, category-level PSA revealed robustly lower differentiation in older than younger adults in scene-selective, but not object-selective, cortical regions. By contrast, at the item level, robust age-related declines in neural differentiation were evident for both stimulus categories. Moreover, we identified an age-invariant association between category-level scene-selectivity in the parahippocampal place area and subsequent memory performance, but no such association was evident for item-level metrics. Lastly, category and item-level neural metrics were uncorrelated. Thus, the present findings suggest that age-related category- and item-level dedifferentiation depend on distinct neural mechanisms.

Association of SARS-CoV-2 IgG Antibody Levels with Clinical/Laboratory Characteristics in COVID-19 Patients: Data from a Turkish Study.

BACKGROUND: COVID-19 causes clinical manifestations ranging from asymptomatic infection to multi-organ failure. It is reported that those with severe disease have higher anti-SARS-CoV-2 antibody titers compared to asymptomatic or mild cases. We evaluated the correlation of antibody responses with laboratory and clinical indicators in COVID-19 patients. METHODS: Seventy-nine male and 66 female patients (mean age: 39) with at least one positive SARS-CoV-2 RT-PCR test and SARS-CoV-2 IgG antibody result after acute infection were included. RESULTS: Seventy-six (52%), 45 (31%), and 24 (17%) patients had mild, moderate, and severe clinical findings, respectively. Patients with high body mass index and advanced age had significantly more severe disease (p < 0.001). A significant correlation was found between the increase in lymphopenia, C-reactive protein, ferritin, D-dimer, and lactate dehydrogenase and the severity of clinical findings (p = 0.0001). SARS-CoV-2 IgG antibody test was positive in 128 (88.3%) patients. A significant correlation was found between disease severity and antibody levels in the comparison of all groups (p < 0.001). CONCLUSIONS: Long-term monitoring of immune responses will be required to determine the appropriate time for the administration of new vaccines.

Anti-SARS-CoV-2 IgG and Neutralizing Antibody Levels in Patients with Past COVID-19 Infection: A Longitudinal Study

Background: Monitoring the longevity of immunoglobulin G (IgG) responses following severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections is vital to understanding the role of antibodies in preventing infection. Aims: To determine the quantitative IgG responses specific to the Spike-S1 (S1) receptor-binding domain (S1/RBD) region of the virus in serum samples taken between 4 weeks and 7 months after polymerase chain reaction (PCR) positivity in patients who are diagnosed with coronavirus disease-2019 (COVID-19). Study Design: A longitudinal study. Methods: This study included 113 patients with a clinical and molecular diagnosis of COVID-19. The first and second serum samples were taken 1 and 7 months, respectively, after the PCR positivity. S1/RBD-specific IgG antibody response was assayed using anti-SARS-CoV- 2 QuantiVac ELISA (IgG) kit (Euroimmun, Lübeck, Germany). The neutralizing antibodies were investigated in 57 patients whose IgG test results were above the cut-off value. Results: In 57 patients with SARS-CoV-2 IgG, the anti-SARS-CoV-2 IgG quantitative antibody levels significantly decreased after 7 months (Z = −2.197, p = 0.028). A correlation was detected between the anti-SARS-CoV-2 IgG and nAb percent inhibition (IH%) levels detected in 1 month (rs = 0.496, p < 0.001), but without significant correlation in serum samples taken on 7 months. The nAb IH% levels of the first and second were compared for COVID-19 severity and revealed no statistical difference (p = 0.256). In the second serum sample, the nAb IH%s of patients with moderate COVID-19 showed a statistically significant difference from patients with mild COVID-19 (p = 0.018), but without significant differences between severe and moderate or mild COVID-19. Conclusion: SARS-CoV-2 quantitative IgG antibody titers are significantly reduced at long-term follow-up (> 6 months). Due to the limited information on seroconversion, comprehensive studies should be conducted for long-term follow-up of the immune response against SARS-CoV-2.

Evaluation of cyclic direct radionuclide cystography findings with DMSA scintigraphy results in children with a prior diagnosis of vesicoureteral reflux.

OBJECTIVES: Direct radionuclide cystography (DRC) with cyclic imaging is a sensitive method used for the detection of vesicoureteral reflux (VUR). Radionuclide cystography is generally recommended for follow-up evaluation of VUR. The aim of this study was to evaluate cyclic DRC with DMSA scan results during the follow-up period in children with a prior diagnosis of VUR. PATIENTS AND METHODS: DRC findings of 85 children with VUR were evaluated together with DMSA findings during follow-up. VUR grade was classified anatomically as grades I, II, and III reflux. Reflux grades of II and III were regarded as high-grade reflux. Reflux was also graded functionally as transient and continuous on the basis of the presence of reflux on either filling or voiding phases (transient) or both phases (continuous) of at least one cycle. RESULTS: Among 85 children, 32 (38%) exhibited reflux. In five patients, reflux was observed on both sides, and a total of 37 refluxing units (RUs) were evaluated. According to the highest grade attained in either cycle, 31 (84%) units had grade II, five had grade I and one had grade III reflux. Reflux was continuous in 23 (62%) and transient in 14 (38%) RUs. The incidence of an abnormal scan result was higher in continuous reflux group (78%) than in high-grade anatomic reflux group (59%). The addition of a second cycle resulted in the diagnosis of continuous reflux in six (26%) more RUs. DMSA scan findings correlated significantly with functional reflux classification (P<0.05), but not with anatomic reflux classification (P>0.05). CONCLUSION: Functional classification of VUR into continuous and transient reflux resulted in higher correlation with DMSA scan findings compared with anatomic reflux grading in follow-up patients with VUR. Cyclic imaging contributed to continuous reflux diagnosis. The significance of functional information obtained from cyclic DRC in initial diagnostic workup, management, and follow-up of children with urinary tract infection needs to be determined with further studies.

Fragmented QRS on 12-Lead Electrocardiogram Is Correlated With Severe Coronary Artery Disease and Abnormal Myocardial Perfusion Scintigraphy Results in Renal Transplant Candidates.

OBJECTIVES: Coronary artery disease is a major cause of mortality and morbidity after renal transplant. Fragmented QRS on standard 12-lead electrocardiograms has been proposed as a marker of myocardial scar, mainly due to coronary artery disease. Here, we aimed to investigate fragmented QRS to detect severe coronary artery disease in renal transplant candidates. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 534 patients with end-stage renal failure who were on the deceased-donor renal transplant wait list at Baskent University Faculty of Medicine due to having no living kidney donor available. We evaluated patients with standard 12-lead electrocardiograms, myocardial perfusion scintigraphy, and coronary angiography. We compared fragmented QRS prevalence versus myocardial perfusion scintigraphy abnormalities and severe coronary artery disease. Correlations among these were analyzed. RESULTS: Of 92 renal transplant candidates (median age of 56.5 y; range, 24-80 y), 87 patients (94.6%) had myocardial perfusion defects and 72 (78.3%) had myocardial wall motion abnormalities on myocardial perfusion scintigraphy. Forty-four patients (47.8%) had severe coronary artery disease on coronary angiography, and 51 patients (55.4%) had fragmented QRS. Fragmented QRS was significantly more common among patients with myocardial scar. Coronary artery disease was significantly more common in patients with fragmented QRS (P = .042) and in those with fragmented QRS combined with myocardial perfusion defects (P < .01). Fragmented QRS was significantly correlated with presence of myocardial scar and any perfusion defects. When combined with myocardial perfusion defects, fragmented QRS was significantly correlated with severe coronary artery disease (P < .05). CONCLUSIONS: Fragmented QRS was significantly correlated with abnormal myocardial perfusion scintigraphy and severe coronary artery disease in renal transplant candidates. This simple parameter can provide valuable information on severe coronary artery disease and help to prevent excess patient morbidity and mortality from this disease after renal transplant.

Hematoma de la vaina de los rectos en un recién nacido macrosómico después de un parto distócico: A propósito de un caso / Rectus sheath hematoma in a macrosomie neonate following difficult delivery: Case report

La macrosomía es un factor de riesgo de traumatismos obstétricos y se asocia con morbimortalidad neonatal. El cefalohematoma y la fractura clavicular son los más frecuentes. Los traumatismos intrabdominales son poco frecuentes. El hematoma de la vaina de los rectos es una acumulación de sangre en la vaina del músculo recto mayor del abdomen. Se asocia con traumatismos, cirugías y tratamiento anticoagulante, en especial en los adultos y las personas de edad avanzada. En este artículo presentamos el caso de un recién nacido de sexo masculino con parto vaginal distócico. Durante el examen físico se observó un hematoma periumbilical de 1 x 1 cm y un cefalohematoma parietal de 1 x 1 cm. En la ecografía abdominal y la tomografía computada del abdomen se observó un hematoma de la vaina del recto derecho de 7 x 4 x 2 cm.

Macrosomia is a risk factor for birth injuries and is associated with neonatal morbidity and mortality. Cephalohematoma and clavicular fracture are the most frequent birth injuries. Intraabdominal injuries are uncommon birth injuries. Rectus sheath hematoma (RSH) is an accumulation of blood in the sheath of rectus abdominis muscle. It is associated with trauma, operations and anticoagulant therapy, especially in adults and elders. We present a macrosomic male neonate with difficult vaginal delivery, who had in the physical examination periumblical ecchymose of 1x1 cm and a parietal cephalohametoma of 1x1 cm. The abdominal ultrasonogram and the computed tomography scan of the abdomen showed a 7x4x2 cm right rectus sheath hematoma.

Rectus sheath hematoma in a macrosomie neonate following difficult delivery. Case report. / Hematoma de la vaina de los rectos en un recién nacido macrosómico después de un parto distócico. A propósito de un caso.

Macrosomia is a risk factor for birth injuries and is associated with neonatal morbidity and mortality. Cephalohematoma and clavicular fracture are the most frequent birth injuries. Intraabdominal injuries are uncommon birth injuries. Rectus sheath hematoma (RSH) is an accumulation of blood in the sheath of rectus abdominis muscle. It is associated with trauma, operations and anticoagulant therapy, especially in adults and elders. We present a macrosomic male neonate with difficult vaginal delivery, who had in the physical examination periumblical ecchymose of 1x1 cm and a parietal cephalohametoma of 1x1 cm. The abdominal ultrasonogram and the computed tomography scan of the abdomen showed a 7x4x2 cm right rectus sheath hematoma.

La macrosomía es un factor de riesgo de traumatismos obstétricos y se asocia con morbimortalidad neonatal. El cefalohematoma y la fractura clavicular son los más frecuentes. Los traumatismos intrabdominales son poco frecuentes. El hematoma de la vaina de los rectos es una acumulación de sangre en la vaina del músculo recto mayor del abdomen. Se asocia con traumatismos, cirugías y tratamiento anticoagulante, en especial en los adultos y las personas de edad avanzada. En este artículo presentamos el caso de un recién nacido de sexo masculino con parto vaginal distócico. Durante el examen físico se observó un hematoma periumbilical de 1 x 1 cm y un cefalohematoma parietal de 1 x 1 cm. En la ecografía abdominal y la tomografía computada del abdomen se observó un hematoma de la vaina del recto derecho de 7 x 4 x 2 cm.

Partial nephrectomy in horseshoe kidney: Primary carcinoid tumor.

Primary neuroendocrine carcinoma of the kidney is a rarely observed clinical condition because neuroendocrine cells are not found in kidney parenchyma. It's not clinically and radiologically possible to distinguish from other kidney tumors. Incidence with horseshoe kidney anomaly, it should be considered as a definitive diagnosis for the patients with this condition. In this case report, we reported about a carcinoid tumor in horseshoe kidney in a 37-year-old woman.

Metal Complexation Properties of Schiff Bases Containing 1,3,5-Triazine Derived from 2-Hydroxy-1-Naphthaldehyde in Solution. A Simple Spectrofluorimetric Method to Determine Mercury (II).

Four new Schiff base ligands carrying naphthalene groups were prepared from the reaction of 2,4-diamino-6-methyl-1,3,5-triazine and 2,4-diamino-6-undecyl-1,3,5-triazine with 2-hydroxy-1-naphthaldehyde. The influence of a series of metal ions including Cu2+, Co2+, Hg2+, Al3+, Cr3+, Fe3+, Pb2+, Ni2+, Cd2+, Zn2+, Mn2+, Ag+, Ba2+, Ca2+ and Mg2+ on the spectroscopic properties of the ligands was investigated by means of absorption and emission spectrometry. The results of spectrophotometric and spectrofluorimetric titrations disclosed the complexation stoichiometry and complex stability constant of the ligands with metal ions. A simple spectrofluorimetric method was developed using the Schiff base derived from 2,4-diamino-6-undecyl-1,3,5-triazine to determine Hg2+ ion. No cleanup or enrichment of the tap water sample was required. A modified standard addition method was used to eliminate matrix effect. The standard addition graph was linear between 0.2 and 2.6 mg/L in determination of Hg2+. Detection and quantification limits were 0.08 and 0.23 mg/L, respectively. The simple and cost-effective method can be applied to water samples.

Percutaneous transluminal balloon angioplasty in stenosis of native hemodialysis arteriovenous fistulas: technical success and analysis of factors affecting postprocedural fistula patency.

PURPOSE: We aimed to determine the predictors of technical success and patency after percutaneous transluminal angioplasty (PTA) of de novo dysfunctional hemodialysis arteriovenous fistulas (AVF). METHODS: We performed a retrospective analysis of first time PTA in 228 patients (129 men, 99 women; mean age, 56.8±14.6 years). Anatomical (location, length, grade, and number of stenoses) and clinical variables (sex, age, prior AVF, diabetes mellitus, AVF age, side, and location) were reviewed. RESULTS: A total of 330 stenoses were found in 228 patients. PTA was technically successful in 96.3% of the stenoses (n=319). Clinical success was achieved in 97.2% (n=321). Early dysfunction (within six months) was positively correlated with patient age (P < 0.001) and diabetes (P < 0.005). Older age (P < 0.001) and diabetes (P = 0.002) were associated with a lower primary patency rate. Patient age (P %lt; 0.001), presence of diabetes (P = 0.023), length of stenosis (P = 0.003), early recurrence (P = 0.003) and presence of residual stenosis (P = 0.014) were associated with a lower secondary patency rate. CONCLUSION: Patency of dysfunctional hemodialysis fistulas can be maintained safely with continuous follow-up and repeated interventions without shortening the venous segment by surgical revision. Percutaneous approach to hemodialysis access stenosis is an alternative to the conventional surgical approach and PTA is an effective treatment method for dysfunctional AVF.