Susceptibility-Weighted MRI for Predicting NF-2 Mutations and S100 Protein Expression in Meningiomas

S100 protein expression levels and neurofibromatosis type 2 (NF-2) mutations result in different disease courses in meningiomas. This study aimed to investigate non-invasive biomarkers of NF-2 copy number loss and S100 protein expression in meningiomas using morphological, radiomics, and deep learning-based features of susceptibility-weighted MRI (SWI). This retrospective study included 99 patients with S100 protein expression data and 92 patients with NF-2 copy number loss information. Preoperative cranial MRI was conducted using a 3T clinical MR scanner. Tumor volumes were segmented on fluid-attenuated inversion recovery (FLAIR) and subsequent registration of FLAIR to high-resolution SWI was performed. First-order textural features of SWI were extracted and assessed using Pyradiomics. Morphological features, including the tumor growth pattern, peritumoral edema, sinus invasion, hyperostosis, bone destruction, and intratumoral calcification, were semi-quantitatively assessed. Mann-Whitney U tests were utilized to assess the differences in the SWI features of meningiomas with and without S100 protein expression or NF-2 copy number loss. A logistic regression analysis was used to examine the relationship between these features and the respective subgroups. Additionally, a convolutional neural network (CNN) was used to extract hierarchical features of SWI, which were subsequently employed in a light gradient boosting machine classifier to predict the NF-2 copy number loss and S100 protein expression. NF-2 copy number loss was associated with a higher risk of developing high-grade tumors. Additionally, elevated signal intensity and a decrease in entropy within the tumoral region on SWI were observed in meningiomas with S100 protein expression. On the other hand, NF-2 copy number loss was associated with lower SWI signal intensity, a growth pattern described as "en plaque", and the presence of calcification within the tumor. The logistic regression model achieved an accuracy of 0.59 for predicting NF-2 copy number loss and an accuracy of 0.70 for identifying S100 protein expression. Deep learning features demonstrated a strong predictive capability for S100 protein expression (AUC = 0.85 ± 0.06) and had reasonable success in identifying NF-2 copy number loss (AUC = 0.74 ± 0.05). In conclusion, SWI showed promise in identifying NF-2 copy number loss and S100 protein expression by revealing neovascularization and microcalcification characteristics in meningiomas.

The effect of informative video before the procedure on anxiety levels in patients who will have ureteral stent removal under local anesthesia

OBJECTIVE

Our objective was to assess the impact of video-animated information on the anxiety levels of patients undergoing ureteral stent removal under local anesthesia.

METHOD

The study was designed as a randomized prospective trial. The one group received only verbal and written information before the surgery, while the other group received video-animated information in addition to the written and verbal instructions. The patients' anxiety levels were assessed using the STAI-S and STAI-T questionnaires, while their pain scores were evaluated using VAS scores. Tolerability and satisfaction scores were also evaluated on a 5-point Likert scale.

RESULTS

The video-group (Group 1) consisted of 74 patients, while the non-video group (Group 2) consisted of 82 patients. The mean pre-information STAI-T score was 34.4 ± 3.7 in Group 1 and 35.2 ± 3 in the Group 2 (p = 0.113). In the video group, pre-information STAI-S scores was 34.8 ± 3.3 and post-information STAI-S scores was 33.8 ± 3 (p < 0.001). In the non-video group, pre-information STAI-S score was 35.6 ± 2.6 and post-information STAI-S score was 35.5 ± 2.7 (p = 0.260). The mean VAS score of Group 1 is 5.7 ± 1.2 and Group 2 is 5.7 ± 1.4 (p = 0.608). The mean tolerability scores of Group 1 and Group 2 were 3.7 ± 0.9 and 2.7 ± 1, respectively. The mean satisfaction scores of Group 1 and Group 2 were 4.1 ± 0.9 and 2.6 ± 1, respectively. Both tolerability score and satisfaction score improved statistically significantly after video information (p < 0.001).

CONCLUSION

Providing video-animated information in addition to written and verbal information before removing the ureteral stent reduces patients' preoperative anxiety. Furthermore, patient tolerance and satisfaction are higher when informative videos are included.

The Efficiency of Focused Assessment with Sonography for Trauma in Pediatric Patients with Blunt Torso Trauma

Introduction

Focused Assessment with Sonography for Trauma (FAST) has attracted attention for its use in the detection of intra-abdominal pathology for pediatric patients. However, computed tomography (CT) remains the gold standard for the assessment of blunt torso trauma. The study examines the effectiveness of FAST both in the detection of intra-abdominal pathology in pediatric patients (<19 years) with blunt torso trauma and in the determination of the need for CT for further examination.

Methods

The study was designed as a retrospective observational investigation of diagnostic value. The pediatric patients who were admitted to the Emergency Department with blunt torso trauma between January 2013 and October 2016 were included in the study. The sample of the study comprised 255 patients who met the inclusion criteria. The primary outcome was the effectiveness of FAST in the detection of intra-abdominal pathology and the determination of the need for CT. The secondary outcome was to identify the agreement between CT and FAST for intra-abdominal injuries. The Chi-square test and Fisher's exact test were used for comparisons. A logistic regression model was developed to determine the variables that independently affect the agreement between FAST and CT.

Results

FAST was determined to have low sensitivity (20.3%) despite its high specificity (87%). However; FAST had a good negative likelihood ratio. There was a poor agreement between CT and FAST in terms of the presence of both intra-abdominal and intrathoracic injuries in pediatric patients with blunt trunk trauma. The error rate of FAST increased by five-fold, especially in the presence of concomitant thorax trauma. However, FAST had a good negative likelihood ratio.

Conclusion

FAST should not be regarded as an equivalent tool to CT for pediatric patients with blunt torso trauma. It is, instead, a noteworthy complementary tool that is a negative predictor.

Association between vitamin D receptor gene FokI polymorphism and mortality in patients with sepsis

BACKGROUND

Sepsis is life-threatening organ dysfunction as a result of the host's dysregulated immune response to infection. The vitamin D receptor (VDR) gene FokI polymorphism influences immune cell behavior. In the present study, we aimed to investigate the association between VDR FokI polymorphism and mortality in sepsis and non-sepsis patients in the intensive care unit (ICU).

METHODS AND RESULTS

This is a prospective observational study involving 96 sepsis and 96 non-sepsis patients admitted to the Ege University ICU. VDR FokI polymorphisms were investigated, as well as the relationship between the identified polymorphisms and mortality.  In-hospital mortality was 27.1% in the sepsis group and 8.33% in the non-sepsis group (p = 0.001). The frequencies of VDR FokI TT, TC, and CC genotypes were 8 (8.33%), 48 (50.0%), and 40 (41.7%) in the sepsis group, and 11 (11.5%), 42 (43.8%), and 43 (44.8%) in the non-sepsis group, respectively (p = 0.612). In the sepsis group, the frequencies of Fokl TT, TC, and CC genotypes did not differ significantly between survivors and non-survivors. However, homozygous C allele carriers had lower overall mortality (p = 0.047).

CONCLUSION

The VDR FokI polymorphism, particularly the CC genotype, appears to be associated with lower mortality in ICU patients.

Development and pharmaceutical investigation of novel cervical cancer-targeting and redox-responsive melittin conjugates

Cervical cancer has recently become one of the most prevalent cancers among women throughout the world. Traditional cancer therapies generate side effects due to off-target toxicity. Thus, novel cancer medications coupled with suitable drug delivery systems are required to improve cancer therapies. Melittin peptide has a high affinity to disrupt cancer cells. In this study, we designed targeted and redox-responsive Melittin conjugates for cervical cancer and then tested them in vitro. Folic acid and squamous cell carcinoma-specific peptide (CKQNLAEG) were used as targeting agents to design various conjugates. Our findings indicate that both anticancer conjugates were effective against different cancer cell lines, including MCF-7, C33A, and HeLa. Moreover, these conjugates were found to have antioxidant and antibacterial effects as well as reduced hemolytic activity. The CM-Target (N-terminus cysteine modified-Melittin-targeting peptide-functionalized conjugate) has become more stable and acted specifically against squamous cell carcinoma, whereas folic acid (FA)-containing conjugates acted efficiently against all cancer types studied, especially for breast cancer. According to our results, these anticancer conjugates may be possible anticancer drug candidates that have fewer adverse effects.

In vitro efficacy of different PEGylation designs on cathelicidin-like peptide with high antibacterial and antifungal activity

Recent reports on antibiotic resistance have highlighted the need to reduce the impact of this global health issue through urgent prevention and control. The World Health Organization currently considers antibiotic resistance as one of the most dangerous threats to global health. Therefore, Antimicrobial peptides (AMPs) are promising for the development of novel antibiotic molecules due to their high antimicrobial effects, non-inducing antimicrobial resistance (AMR) properties, and broad spectrum. Hence, in this study, we developed novel antimicrobial peptide/polymer conjugates to reduce the adverse effects of TN6 (RLLRLLLRLLR) peptide. We demonstrate how our constructs function in vitro in terms of antimicrobial activity, hemolytic activity, cytotoxicity, and protease resistance. Our findings show that our molecules are effective against different types of microorganisms such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant S. aureus, vancomycin-resistant Enteroccus faecium, and Candida albicans, which are known to be pathogenic and antibiotic-resistant. Our constructs generally showed low cytotoxicity relative to the peptide in HaCaT and 3T3 cells. Especially these structures are very successful in terms of hemotoxicity. In the bacteremia model with S. aureus, the naked peptide (TN6) was hemotoxic even at 1 µg/mL, while the hemotoxicity of the conjugates was considerably lower than the peptide. Remarkably in this model, the hemolytic activity of PepC-PEG-pepC conjugate decreased 15-fold from 2.36 to 31.12 µg/mL compared to the bacteria-free 60-min treatment. This is proof that in the case of bacteremia and sepsis, the conjugates specifically direct to bacterial cell membranes rather than red blood cells. In addition, the PepC-PEG-pepC conjugate is resistant to plasma proteases. Moreover, morphological and intracellular damage of the peptide/conjugates to Escherichia coli are demonstrated in SEM and TEM images. These results suggest our molecules can be considered potential next-generation broad-spectrum antibiotic molecule/drug candidates that might be used in clinical cases such as bacteremia and sepsis.

Bioinspired Multi-Layer Biopolymer-Based Dental Implant Coating for Enhanced Osseointegration

The major drawbacks of metal-based implants are weak osseointegration and post-operational infections. These limitations restrict the long-term use of implants that may cause severe tissue damage and replacement of the implant. Recent strategies to enhance the osseointegration process require an elaborate fabrication process and suffer from post-operative complications. To address the current challenges taking inspiration from the extracellular matrix (ECM), the current study is designed to establish enhanced osseointegration with lowered risk of infection. Natural biopolymer pectin, peptide amphiphiles, and enzyme-mimicking fullerene moieties are governed to present an ECM-like environment around the implant surfaces. This multifunctional approach promotes osseointegration via inducing biomineralization and osteoblast differentiation. Application of the biopolymer-based composite to the metal surfaces significantly enhances cellular attachment, supports the mineral deposition, and upregulates osteoblast-specific gene expression. In addition to the osteoinductive properties of the constructed layers, the inherent antimicrobial properties of multilayer coating are also used to prevent infection possibility. The reported biopolymer-artificial enzyme composite demonstrates antimicrobial activity against Escherichia coli and Bacillus subtilis as a multifunctional surface coating.

Retrospective evaluation of the efficacy of daily paroxetine/tadalafil combination in patients with premature ejaculation and erectile dysfunction

OBJECTIVE

Premature ejaculation (PE) and erectile dysfunction (ED) are sexual dysfunction diseases affecting males. The phosphodiesterase type 5 (PDE5) inhibitors such as tadalafil are used to treat ED whereas selective serotonin reuptake inhibitors (SSRIs) are preferred for PE. Most of the patients with ED also suffer from PE simultaneously. The combined drug therapies are commonly preferred as they favor elevated intra-vaginal ejaculation latency time (IELT) scores and improved sexual function. The study aimed to evaluate the efficacy and safety of daily paroxetine and tadalafil combination therapy in patients with PE and ED.

PATIENTS AND METHODS

A total of 81 PE patients with ED were enrolled in the study. Patients were treated with daily paroxetine 20 mg and tadalafil 5 mg for 4 weeks. Pre- and post-treatment IELT, premature ejaculation profile (PEP), and International Index of Erectile Function-Erectile Function (IIEF-EF) scores of the patients were analyzed.

RESULTS

The mean IELT and PEP index scores, and mean IIEF-EF values improved after combination therapy (p<0.001 for each). When lifelong and acquired PE+ED patients were compared, significant improvements were observed in IELT, PEP, and IIEF-EF scores in both groups (p<0.001).

CONCLUSIONS

Even though the treatment methods are different, combined therapies to treat simultaneous PE and ED presence are effective compared to monotherapies. However, there is still no definitive treatment that can cure all subtypes of PE or ED.

Melatonin in preservation solutions prevents ischemic injury in rat kidneys

Transplantation is lifesaving and the most effective treatment for end-stage organ failure. The transplantation success depends on the functional preservation of organs prior to transplantation. Currently, the University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) are the most commonly used preservation solutions. Despite intensive efforts, the functional preservation of solid organs prior to transplantation is limited to hours. In this study, we modified the UW solution containing components from both the UW and HTK solutions and analyzed their tissue-protective effect against ischemic injury. The composition of the UW solution was changed by reducing hydroxyethyl starch concentration and adding Histidine/Histidine-HCl which is the main component of HTK solution. Additionally, the preservation solutions were supplemented with melatonin and glucosamine. The protective effects of the preservation solutions were assessed by biochemical and microscopical analysis at 2, 10, 24, and 72 h after preserving the rat kidneys with static cold storage. Lactate dehydrogenase (LDH) activity in preservation solutions was measured at 2, 10, 24, and 72. It was not detectable at 2 h of preservation in all groups and 10 h of preservation in modified UW+melatonin (mUW-m) and modified UW+glucosamine (mUW-g) groups. At the 72nd hour, the lowest LDH activity (0.91 IU/g (0.63–1.17)) was measured in the mUW-m group. In comparison to the UW group, histopathological damage score was low in modified UW (mUW), mUW-m, and mUW-g groups at 10, 24, and 72 hours. The mUW-m solution at low temperature was an effective and suitable solution to protect renal tissue for up to 72 h.

Simple concentration method enables the use of gargle and mouthwash instead of nasopharyngeal swab sampling for the diagnosis of COVID-19 by PCR

Since its emergence in December 2019, SARS-CoV-2 is causing one of the most devastating pandemics in human history. Currently, the most important method for definitive diagnosis of COVID-19 is identification of SARS-CoV-2 RNA in nasopharyngeal swab samples by RT-PCR. Nasopharyngeal swab sampling is a discomforting procedure sometimes with adverse effects, which also poses a risk for infection for the personnel performing the sampling. We have developed a new method for concentrating biological samples, which enabled us to use gargle and mouthwash samples to be used in RT-PCR, for the diagnosis of COVID-19, as an alternative to nasopharyngeal swab samples. We have analyzed nasopharyngeal and gargle and mouthwash samples, before and after concentration, of 363 patients by RT-PCR for the presence of SARS-CoV-2. Among 114 patients in which SARS-CoV-2 was identified in at least one of their samples, the virus was identified in 76 (66.7%), 67 (58.8%), and 101 (88.6%) of nasopharyngeal swab, gargle, and mouthwash samples before and after concentration, respectively. When concentrated by our new method, gargle and mouthwash samples can be used instead of nasopharyngeal samples in identification of SARS-CoV-2 by RT-PCR, with the same or better sensitivity. Eliminating the need for nasopharyngeal sampling will save the patients from an invasive and painful procedure and will lower the risk of infection for the healthcare personnel taking the sample. This easy sampling procedure may decrease the workload of hospitals, shorten the turnaround time of obtaining test results, and thus enable rapid isolation of infected patients.

BIMG-14. IDENTIFICATION OF IDH MUTATION STATUS USING PROTON MR SPECTROSCOPY AND MASS SPECTROMETRY: A STUDY OF 178 GLIOMAS

IDH mutation, a key factor in predicting glioma prognosis, alters the levels of some metabolites in brain, including 2-hydroxyglutarate (2HG), glutamine (Gln), and glutathione (GSH). While proton MR spectroscopy (¹H-MRS) enables in-vivo detection of these metabolites, liquid chromatography-mass spectrometry (LC-MS/MS) is a sensitive in-vitro method to measure absolute metabolite concentrations. This study aims to examine the correlation of metabolic concentrations measured using ¹H-MRS and LC-MS/MS in gliomas, and to detect IDH mutation with machine learning based on ¹H-MRS and LC-MS/MS metabolic intensities. The patient cohort included 178 glioma patients (111M/67F, mean age:44.09±13.95 years, 100 IDH-mut, 78 IDH-wt). The patients were scanned pre-surgery by a 3T MR scanner with a 32-channel head coil. ¹H-MRS was obtained from a manually placed region of interest with no necrosis, edema, and hemorrhage, using a Point Resolved Spectroscopy (PRESS) sequence (TR/TE=2000/30ms). LCModel software was used for quantification of eighteen metabolites of ¹H-MRS data. Metabolite concentrations including creatine (Cr), choline (Cho), Gln, glutamate (Glu), gamma-aminobutyric acid (GABA), N-acetyl aspartate (NAA), myo-inositol (mIns), 2HG, and lactate (Lac) were also determined with LC-MS/MS for surgical specimen of the same patients. Spearman correlation coefficients were calculated between the metabolite concentrations measured with ¹H-MRS and LC-MS/MS. Additionally, machine-learning algorithms were used to detect IDH mutation in gliomas based on metabolite concentrations obtained with ¹H-MRS and LC-MS/MS. Consequently, there were statistically significant correlations between ¹H-MRS and LC-MS/MS results for 2HG (p=0.036), Cr (p=0.009), mIns (p<0.001), Lac (p=0.007) and NAA (p=0.004). IDH mutation was detected with an accuracy of 92.42% (sensitivity=91.70%, specificity=93.46) and 82.94% (sensitivity=84.04, specificity=81.43) based on LC-MS/MS and ¹H-MRS metabolic intensities, respectively. In conclusion, ¹H-MRS and LC-MS/MS metabolic intensities were highly correlated and these techniques were successful in identifying IDH mutation in gliomas. This study has been supported by TUBITAK 1003 grant 216S432.

NF-κB-Induced Upregulation of miR-548as-3p Increases Invasion of NSCLC by Targeting PTEN

BACKGROUND

Non-Small Cell Lung Cancer (NSCLC) is an aggressive cancer type due to high metastatic capacity. Nuclear Factor Kappa B (NF-κB) is a consistently active transcription factor in malignant lung cancer cells and has crucial significance in NSCLC progression. It is also implicated in the transcriptional regulation of many genes including microRNAs (miRNAs) that function as tumor suppressor or oncogene. It has been increasingly reported that several miRNAs defined as gene members are induced by NF-κB. The present study aimed to find novel miRNAs that are regulated by NF-κB.

METHODS

Chromatin İmmunoprecipitation Sequencing (ChIP-Seq) experiment and bioinformatic analysis were used to determine NF-κB-dependent miRNAs. Western blot analysis, quantitative real-time polymerase chain reaction (qRT-PCR), luciferase reporter gene assays were carried out to investigate the target genes of miRNAs. To determine biologic activity, transwell invasion and MTT assay were carried out on H1299 NSCLC cell line. miRNA expression level was evaluated in metastatic and non-metastatic tissue samples of NSCLC patients.

RESULTS

ChIP-Seq and qRT-PCR experiments showed that miR-548as-3p is transcriptionally regulated by NF- κB in response to Tumor Necrosis Factor-α (TNF-α) treatment. Then, we found that tumor suppressor Phosphatase and Tension homolog (PTEN) is a direct target of miR-548as-3p. Furthermore, miR-548as-3p mediates phosphatidylinositol-3-OH kinase (PI3K)/Akt pathway and NF-κB-implicated genes including Matrix Metalloproteinases 9 (MMP9), Slug and Zeb1. We further showed that miR-548as-3p increased invasiveness of NSCLC cells and was upregulated in metastatic tumor tissues compared to non-metastatic ones.

CONCLUSION

All these findings provide a miRNAs-mediated novel mechanism for NF-κB signaling and that miR-548as-3p could be a biomarker for NSCLC metastasis.

Nivolumab, a new immunomodulatory drug, a new adverse effect; adrenal crisis

Owing to the advancements in medicine, new information is obtained regarding cancer, new antineoplastic agents are developed. Frequent use of these new pharmacological agents emergency physicians to be vigilant about their side effects. We present a case of adrenal crisis in a patient with non-small cell lung cancer (NSCLC), caused by an immunomodulatory drug; nivolumab. While adverse events are related to other immunomodulatory drugs have been reported in literature, our case is the first nivolumab-related adrenal failure to be reported. A patient with lung cancer presented to the emergency room(ER) with nausea and vomiting. Hyponatremia, hyperkalemia, persistent hypoglycemia led to the diagnosis of adrenal crisis. Having direct effect on the immune system, these drugs were claimed to be highly reliable. However, there is no reliable data on the side effect profile of these agents. It should be kept in mind that life-threatening auto-immune reactions may occur.

Perchlorate Exposure Through Water and Milk in Istanbul

Perchlorate is a chemical pollutant that inhibits iodide uptake and may possibly impair thyroid function. Our previous study found widespread perchlorate exposure in non-pregnant, non-lactating, healthy women residing in Istanbul. The aim of this study is to assess the relative amounts of perchlorate exposure attributable to consumption of municipal water, bottled water and boxed milk available in Istanbul. Only trace levels of perchlorate were found in treated municipal water (58 % detectable, mean = 0.13 µg/L, maximum = 0.75 µg/L) and bottled water (7.4 % detectable, mean = <LOD, maximum = 0.19 µg/L). Conversely, all 30 boxed milk samples contained measurable levels of perchlorate (mean = 4.53 µg/L; maximum = 6.21 µg/L). Median perchlorate exposure attributable to water and milk (0.007 µg/kg/day) is small compared both to the reference dose (0.7 µg/kg/day) and to total perchlorate exposure (0.13 µg/kg/day) in Istanbul. Therefore, additional studies are needed to identify the major sources of perchlorate exposure in Istanbul.

The administration sequence of propofol and remifentanil does not affect the ED50 and ED95 of rocuronium in rapid sequence induction of anesthesia: a double-blind randomized controlled trial

OBJECTIVE

The topic of drug administration sequence in rapid sequence induction (RSI) is still an object of interest in terms of rocuronium effectiveness. The aim of this prospective, randomized trial was to evaluate the effect of administration sequence of propofol and remifentanil on ED50 and ED95 of rocuronium in a RSI model.

PATIENTS AND METHODS

Eighty-four patients were randomized into Group Remifentanil (Group R, n = 43), where induction of general anesthesia started with remifentanil (2 µg/kg) and followed by propofol (2 mg/kg) and rocuronium administrations; and Group Propofol (Group P, n = 41), where induction of general anesthesia started with propofol and followed by remifentanil and rocuronium. First patients in each group were paralyzed by 0.8 mg/kg rocuronium. In case of acceptable intubation as evaluated according to the criteria described by Viby-Mogensen et al, rocuronium dose was decreased by 0.1 mg/kg for the next patient; otherwise, rocuronium dose was increased by 0.1 mg/kg. After three crossover points, increments or decrements in rocuronium dosage were set to 0.05 mg/kg. The process was repeated until a total of ten crossover points were obtained.

RESULTS

The ED50 and ED95 doses of rocuronium were similar in Group R (0.182 mg/kg, and 0.244 mg/kg, respectively) and Group P (0.121 mg/kg, and 0.243 mg/kg, respectively) according to 95% CI of the estimates. There was no statistically significant difference in terms of clinically acceptable intubation conditions between the two groups (56.1% in Group R vs. 59% in Group P, p = 0.795).

CONCLUSIONS

The choice of administration sequence of propofol and remifentanil does not have an impact on estimated ED50 and ED95 of rocuronium in providing acceptable intubation conditions in the RSI technique.

Post-translational modifications of transthyretin affect the triiodonine-binding potential

Transthyretin (TTR) is a visceral protein, which facilitates the transport of thyroid hormones in blood and cerebrospinal fluid. The homotetrameric structure of TTR enables the simultaneous binding of two thyroid hormones per molecule. Each TTR subunit provides a single cysteine residue (Cys₁₀), which is frequently affected by oxidative post-translational modifications. As Cys₁₀ is part of the thyroid hormone-binding channel within the TTR molecule, PTM of Cys₁₀ may influence the binding of thyroid hormones. Therefore, we analysed the effects of Cys₁₀ modification with sulphonic acid, cysteine, cysteinylglycine and glutathione on binding of triiodothyronine (T3) by molecular modelling. Furthermore, we determined the PTM pattern of TTR in serum of patients with thyroid disease by immunoprecipitation and mass spectrometry to evaluate this association in vivo. The in silico assays demonstrated that oxidative PTM of TTR resulted in substantial reorganization of the intramolecular interactions and also affected the binding of T3 in a chemotype- and site-specific manner with S-glutathionylation as the most potent modulator of T3 binding. These findings were supported by the in vivo results, which indicated thyroid function-specific patterns of TTR with a substantial decrease in S-sulphonated, S-cysteinylglycinated and S-glutathionylated TTR in hypothyroid patients. In conclusion, this study provides evidence that oxidative modifications of Cys₁₀ seem to affect binding of T3 to TTR probably because of the introduction of a sterical hindrance and induction of conformational changes. As oxidative modifications can be dynamically regulated, this may represent a sensitive mechanism to adjust thyroid hormone availability.

Quantification of fibrin degradation products in glioma and meningioma patients

BACKGROUND

DR-70 is an immunoassay for fibrin and FDP in plasma and it has been shown useful in detection of over 14 different cancers. This study investigated the validity of the DR-70 test in gliomas as well as meningiomas.

METHODS

77 brain tumor patients as well as 40 healthy individuals were prospectively included in the study and investigated using DR-70 kit. The glioma cohort of 33 patients consisted of 1, 11, 6 and 15 WHO grade 1, 2, 3 and 4 gliomas, respectively. The meningioma cohort of 44 patients contained 38, 5 and 1 WHO grade 1, 2 and 3 tumors.

RESULTS

Test results were significantly higher than control values for both gliomas and meningiomas. The most balanced sensitivity and specificity values were obtained at cut-off level of 0.5 μg/ml FDP for both gliomas and meningiomas. Above this cutoff level the relative-risk for having a glioma was 5.1 times higher compared to controls with sensitivity and specificity of 76% and 85%, respectively. The relative-risk for meningioma was 5.8 with a sensitivity and specificity of 87% and 85%, respectively.

CONCLUSION

FDP testing, which is a nonspecific cancer screening tool, is sensitive to the two most common primary brain malignancies, gliomas and meningiomas.

Iodine status in Turkish populations and exposure to iodide uptake inhibitors

Perchlorate, nitrate, and thiocyanate are competitive inhibitors of the sodium iodide symporter of the thyroid membrane. These inhibitors can decrease iodine uptake by the symporter into the thyroid gland and may disrupt thyroid function. This study assesses iodine status and exposure to iodide uptake inhibitors of non-pregnant and non-lactating adult women living in three different cities in Turkey (Istanbul, Isparta and Kayseri). We measured iodine and iodide uptake inhibitors in 24-hr urines collected from study participants (N = 255). All three study populations were mildly iodine deficient, with median urinary iodine (UI) levels of 77.5 µg/L in Istanbul, 58.8 µg/L in Isparta, and 69.8 µg/L in Kayseri. Perchlorate doses were higher in the study population (median 0.13 µg/kg/day), compared with a reference population (median 0.059 µg/kg/day), but lower than the U.S. EPA reference dose (0.7 µg/kg/day). Urinary thiocyanate levels increased with increasing exposure to tobacco smoke, with non-smokers (268 µg/L) significantly lower than light smokers (1110 µg/L), who were significantly lower than heavy smokers (2410 µg/L). This pilot study provides novel data indicating that study participants were moderately iodine deficient and had higher intakes of the iodide uptake inhibitor perchlorate compared with a reference population. Further investigation is needed to characterize the thyroid impact resulting from iodine deficiency coupled with exposure to iodide uptake inhibitors such as perchlorate, thiocyanate and nitrate.

Reference interval of pregnancy-associated plasma protein-a in healthy men and non-pregnant women

OBJECTIVE

The serum pregnancy-associated plasma protein-A (PAPP-A) concentration is a predictor of ischemic cardiac events and renal impairment. However, the reference interval of PAPP-A has not been determined. This study determined the reference interval of PAPP-A in men and non-pregnant women.

METHODS

The study enrolled 126 apparently healthy individuals (52 males and 74 females). The mean age of the men and women was 34.7 (range 20-66) years and 34.6 (range 18-65) years, respectively. Serum PAPP-A concentrations were determined using an ultrasensitive enzyme-linked immunoassay kit. Reference intervals were calculated using the bootstrap method.

RESULTS

The results for three subjects were outliers, so the reference interval of PAPP-A was calculated using the data for 123 subjects. PAPP-A was undetectable in 26 subjects. The reference interval of PAPP-A for men and women (with the 90% confidence interval) was <22.9 ng/mL (19.7-23.3) and <33.6 ng/mL (25.2-36.7), respectively. In male subjects, serum PAPP-A levels of smokers [3.10 (UD, 7.30)ng/mL] were significantly lower than that of non-smokers [11.00 (UD, 24.4)ng/mL] (p<0.001) and there was a positive correlation between serum PAPP-A levels and subjects' age (r=0.439; p<0.001).

CONCLUSIONS

The reference interval of PAPP-A differed for men and non-pregnant women. In clinical practice, <22.9 ng/mL for men and <33.6 ng/mL for non-pregnant women may be used as reference intervals for PAPP-A.

Conjugation of type I antifreeze protein to polyallylamine increases thermal hysteresis activity

Antifreeze proteins (AFPs) are ice binding proteins found in some plants, insects, and Antarctic fish allowing them to survive at subzero temperatures by inhibiting ice crystal growth. The interaction of AFPs with ice crystals results in a difference between the freezing and melting temperatures, termed thermal hysteresis, which is the most common measure of AFP activity. Creating antifreeze protein constructs that reduce the concentration of protein needed to observe thermal hysteresis activities would be beneficial for diverse applications including cold storage of cells or tissues, ice slurries used in refrigeration systems, and food storage. We demonstrate that conjugating multiple type I AFPs to a polyallylamine chain increases thermal hysteresis activity compared to the original protein. The reaction product is approximately twice as active when compared to the same concentration of free proteins, yielding 0.5 °C thermal hysteresis activity at 0.3 mM protein concentration. More impressively, the amount of protein required to achieve a thermal hysteresis of 0.3 °C is about 100 times lower when conjugated to the polymer (3 μM) compared to free protein (300 μM). Ice crystal morphologies observed in the presence of the reaction product are comparable to those of the protein used in the conjugation reaction.