Assessment of nutritional status in children with cancer: Significance of arm anthropometry and serum visceral proteins.

BACKGROUND: Arm anthropometry is a better indicator of nutritional status in children with cancer. The value of serum albumin and prealbumin in nutritional assesment is debatable. We investigated the nutritional status of children with cancer and their serum albumin and prealbumin levels. PATIENTS AND METHODS: At diagnosis and following induction therapies, weight, height, body mass index (BMI), mid-upper arm circumference (MUAC), and triceps skin-fold thickness (TSFT) were measured; serum albumin and prealbumin levels were determined. Prevalences of malnutrition defined by anthropometric indices were calculated. Correlations of anthropometric indices with each other, with serum albumin/prealbumin levels, and clinicopathological parameters were analyzed. RESULTS: In 81 patients, median age was 7.5 years (males/females = 50/31), tumors were located mostly in the abdomen, and abdominal tumors were more common under 5 years. Prevalence of malnutrition according to weight for age, BMI, MUAC, TSFT z scores were 14.8%, 23.5%, 27.2%, 21%, respectively. Defined by combined BMI/MUAC/TSFT measurements, 33/81 cases (40.7%) had malnutrition (z scores < -1, 23 mild; z scores < -2, 10 moderate). Malnutrition was more prevalent under 5 years (P = .03), also in abdominal tumors (P = .03) and advanced disease (P < .001). Younger age and advanced disease were risk factors for malnutrition. At diagnosis, prevalences of low serum albumin and prealbumin levels were 7.4% and 54%, respectively. Cases with malnutrition had significantly lower survival rates. CONCLUSIONS: Nutritional status is assessed best by MUAC and TSFT measurements. Serum prealbumin levels can be used to identify patients at risk of undernutrition. Presence of malnutrition is a significant poor prognostic factor. All children with cancer should undergo nutritional evaluation and active nutritional support.

Joint Modeling Approach on Evaluating Time-Dependent CutOff Values for C-Reactive Protein in Mixed Intensive Care Unit Population.

BACKGROUND: Serial C-reactive protein (CRP) biomarker values are frequently recorded from patients in adult intensive care units (ICU). The aim of this study was to assess the time-dependent diagnostic accuracy of repeated CRP measurements in predicting ICU mortality and determine the time-dependent cutoff values for this biomarker in mixed ICU population. METHODS: Joint modeling was performed to model repeated CRP measurements and survival data. Time-dependent AUC (td-AUC) values were used to assess the diagnostic performances. Maximization of the product of sensitivity and specificity rule was applied to determine the time-dependent cutoff values. RESULTS: Time-dependent diagnostic performance of serial CRP values were found as moderate in overall, observed to be higher in males than females, ranging from 0.603 to 0.624 in females and 0.639 to 0.690 in males. On the other hand, time-dependent cutoff values either remained constant or decreased through the 3rd day after the last measurement for both gender groups. CONCLUSIONS: Newly proposed time-dependent cutoff values for CRP biomarker are suggested to be used in clinics to discriminate subjects who are at risk and who are not during the first three days after the last measurement. Furthermore, taking serial CRP values in predicting the risk of death at ICU is highly recommended, to be able to assess the change in longitudinal profiles of subjects throughout the follow-up period.

Evaluation of gingival crevicular fluid and peri-implant crevicular fluid levels of sclerostin, TWEAK, RANKL and OPG.

BACKGROUND: The combination of local and systemic factors play role in the pathogenesis of periodontal and peri-implant diseases. Host-derived enzymes, cytokines and other proinflammatory mediators play an integral role in this destruction. The aim of this study is to evaluate gingival crevicular fluid (GCF) and peri-implant crevicular (PICF) fluid levels of sclerostin, TNF-related weak inducer of apoptosis (TWEAK), receptor activator of nuclear factor kappa-beta ligand (RANKL) and osteoprotegerin OPG in periodontal and peri-implant tissues in disease and health conditions and also to assess the potential for use as biomarkers. MATERIALS AND METHODS: The study population was consisted of 50 women and 41 men, in the total of 91 individuals, with a mean age of 51.84 ±â€¯14.05. Periodontitis (n = 22), periodontal health (n = 17), peri-implantitis (n = 27) and peri-implant health (n = 25) groups were established according to clinical and radiographic examination results of 39 teeth and 52 implants restored with fixed prosthetic restorations. In all groups, periodontal and peri-implant parameters (probing depth, gingival recession, gingival bleeding time index, gingival index, and plaque index) were recorded and GCF and PICF samples were also collected. Sclerostin, TWEAK, RANKL and OPG levels in GCF and PICF were measured with ELISA tests. RESULTS: Peri-implantitis group presented significantly higher levels of Sclerostin (p = 0.002), TWEAK(p < 0.0001), RANKL(p < 0.0001), and OPG (p = 0.037) compared to peri-implant health group. Similarly, significantly higher levels of TWEAK (p = 0.001), RANKL(p < 0.0001), and OPG(p = 0.025) were detected in periodontitis group when compared to periodontal health group. Statistically significant correlations were also noted between biochemical parameters and clinical parameters. CONCLUSION: Findings of this study evaluating four different bone metabolism related proteins at the same time, suggests levels of sclerostin may be a biomarker for peri-implant disease presenting significantly higher levels in the peri-implantitis group than in the peri-implant health group. Moreover, levels of TWEAK can be a good indicator for both periodontal and peri-implant disease, due to the correlations with periodontal clinical parameters and the higher levels of TWEAK in diseased sites compared to the healthy sites for both dental implants and teeth.

Ti (IV) attached-phosphonic acid functionalized capillary monolith as a stationary phase for in-syringe-type fast and robust enrichment of phosphopeptides.

In this study, poly(vinylphosphonic acid-co-ethylene dimethacrylate), poly(VPA-co-EDMA) capillary monolith was synthesized as a starting material for obtaining a stationary phase for microscale enrichment of phosphopeptides. The chelation of active phosphonate groups with Ti (IV) ions gave a macroporous monolithic column with a mean pore size of 5.4 µm. The phosphopeptides from different sources were enriched on Ti (IV)-attached poly(VPA-co-EDMA) monolith using a syringe-pump. The monolithic capillary columns exhibited highly sensitive/selective enrichment performance with phosphoprotein concentrations as low as 1.0 fmol/mL. Six different phosphopeptides were detected with high intensity by the treatment of ß-casein digest with the concentration of 1.0 fmol/mL, using Ti (IV)@poly(VPA-co-EDMA) monolith. Highly selective enrichment of phosphopeptides was also successfully carried out even at trace amounts, in a complex mixture of digested proteins (molar ratio of ß-casein to bovine serum albumin, 1:1500) and three phosphopeptides were successfully detected. Four highly intense signals of phosphopeptides in human serum were also observed with high signal-to-noise ratio and a clear background after enrichment with Ti (IV)@poly(VPA-co-EDMA) monolith. It was concluded that the capillary microextraction system enabled fast, efficient and robust enrichment of phosphopeptides from microscale complex samples. The whole enrichment process was completed within 20 min, which was shorter than in the previously reported studies.

A multicenter nationwide reference intervals study for common biochemical analytes in Turkey using Abbott analyzers.

BACKGROUND: A nationwide multicenter study was organized to establish reference intervals (RIs) in the Turkish population for 25 commonly tested biochemical analytes and to explore sources of variation in reference values, including regionality. METHODS: Blood samples were collected nationwide in 28 laboratories from the seven regions (≥400 samples/region, 3066 in all). The sera were collectively analyzed in Uludag University in Bursa using Abbott reagents and analyzer. Reference materials were used for standardization of test results. After secondary exclusion using the latent abnormal values exclusion method, RIs were derived by a parametric method employing the modified Box-Cox formula and compared with the RIs by the non-parametric method. Three-level nested ANOVA was used to evaluate variations among sexes, ages and regions. Associations between test results and age, body mass index (BMI) and region were determined by multiple regression analysis (MRA). RESULTS: By ANOVA, differences of reference values among seven regions were significant in none of the 25 analytes. Significant sex-related and age-related differences were observed for 10 and seven analytes, respectively. MRA revealed BMI-related changes in results for uric acid, glucose, triglycerides, high-density lipoprotein (HDL)-cholesterol, alanine aminotransferase, and γ-glutamyltransferase. Their RIs were thus derived by applying stricter criteria excluding individuals with BMI >28 kg/m2. Ranges of RIs by non-parametric method were wider than those by parametric method especially for those analytes affected by BMI. CONCLUSIONS: With the lack of regional differences and the well-standardized status of test results, the RIs derived from this nationwide study can be used for the entire Turkish population.

Acute Alcohol Intoxication-Related Metabolic and Biochemical Disturbances in Adolescents: A Matched Case-Control Study.

We aimed to investigate clinical and laboratory characteristics of acute alcohol intoxication (AAI) in adolescents who presented to the pediatric emergency department (ED) at a tertiary referral center from 2006 to 2019. All consecutive adolescents with AAI (n = 335) and their sex- and age-matched control subjects (n = 335) with undetectable ethanol levels were included in this case-matched study. Mean serum ethanol level was 156.4 ± 58.4 (range: 50.8-341.2) mg/dL in the acute alcohol intoxication (AAI) group. Glasgow coma scores were lower in AAI group (14 [14-15] vs 15 [15-15], P < .001). Acidosis (16.3%), hyperlactatemia (60.9%), hypoglycemia (1.7%), hypernatremia (2.2%), hypokalemia (12.3%), hyperchloremia (20.4%), hypocalcemia (13.9%), hypermagnesemia (9.7%), and hyperalbuminemia (10.4%) were significantly more common in the AAI group than the control group. Blood pH, lactate, Na+, K+, Ca++, Mg++, albumin, blood urea nitrogen (BUN), and uric acid levels were correlated with serum ethanol levels. This study shows that AAI frequently leads to mild to moderate metabolic/biochemical derangements in adolescents.

Evaluation of GCF IL-17, IL-10, TWEAK, and sclerostin levels after scaling and root planing and adjunctive use of diode laser application in patients with periodontitis.

BACKGROUND: The aim of the present study was to evaluate the clinical efficacy of the diode laser as an adjunct to scaling and root planing (SRP) and also determine the biochemical profile by evaluating the gingival crevicular fluid (GCF) levels of interleukin (IL)-17, IL-10, tumor necrosis factor-related weak inducer of apoptosis (TWEAK), and sclerostin. METHODS: A total of 40 systemically healthy, patients with Stage III periodontitis were included in this randomized controlled study. Participants were randomly divided into two groups as SRP + diode laser (L) (0.80W power, 940 nm wavelength and 0.80J/s energy level) and only SRP group. Recording of periodontal parameters and collecting GCF samples were performed at baseline, first and 3rd months. Biomarker levels in GCF were measured with ELISA RESULTS: At baseline, no significant difference was detected between groups in terms of both clinical and biochemical parameters. All biochemical parameters (except for IL-10 in control group), presented a statistically significant difference for 3 months study period in both groups. When laser and control groups were compared, significant differences were not observed, except the lower GCF IL-17 levels (P = 0.025), bleeding on probing (P = 0.028), and clinical attachment level (CAL) (P = 0.0002) values in laser group at third, first, and third months, respectively. Statistically significant correlations were also noted between biochemical parameters and clinical parameters. CONCLUSIONS: The GCF IL-17, TWEAK, and sclerostin levels may be useful for monitoring response to SRP+L therapy. However, long-term studies on higher populations are needed to evaluate the effectiveness of adjunctive use of diode laser application to SRP.

Dental caries and associated salivary biomarkers in patients with cystic fibrosis.

PURPOSE: To evaluate the caries status of the Cystic fibrosis (CF) children and adolescents with the comparation of some biochemical markers, secretory-immunoglobulin-A (sIgA), and antimicrobial peptides in the saliva. METHODS: In this cross-sectional descriptive study, the approval Ethics Board was obtained. Unstimulated saliva samples were collected from CF and healthy control children (non-CF) patients. Both groups underwent the same dental and periodontal evaluation scheme of the assessment. Human beta defensin (HBD1), human alpha defensin (HNP-1), cathelicidin (LL-37), sIgA in saliva were evaluated by enzyme-linked immunoassay method. A general biochemical analysis was performed. Statistical analysis was performed by using Statistical Package for the Social Sciences Version 20.0 (SPSS Inc.). RESULTS: A total of 21 (9 male, 12 female) CF and 23 (11 male, 12 female) control patients were participated with the mean age of 10.17 ± 3.38 and 9.52 ± 2.15 years, respectively. In control children, DMFT/S (decayed-missing-filled-tooth/surface-in-permanent-dentition), dmft/s (decayed-missing-filled-tooth/surface-in-primary-dentition) values were higher; DT (decayed-tooth in permanent dentition), ft (filled-tooth in primary dentition) and plaque index values were statistically significantly higher (p = 0.042, p = 0.005, p = 0.038, respectively) than CF patients. Bicarbonate was higher in control group; sodium, chloride, and total protein were higher in CF group; magnesium, calcium and phosphate levels were similar in each group (p > 0.05). Alpha and beta defensin-1 levels in control group was statistically significantly higher (p = 0.037 and p = 0.020, respectively), while LL37 and sIgA were not statistically significantly higher (p > 0.05) than CF group. CONCLUSIONS: Children with CF had lower caries in permanent teeth, filling in primary teeth, and an altered salivary biomarker profile, especially in HNB1, HNP1. Therefore, it is important to conduct periodic oral-dental controls among CF patients during their childhood.

Cutoff level to detect heterozygous alpha 1 antitrypsin deficiency in Turkish population.

BACKGROUND: Alpha 1 antitrypsin (AT) deficiency is a hereditary disorder leading to the defective defence system against neutrophil elastasis in lung and accumulation of insoluble heterodimer AT molecules in hepatocytes. Knowledge of the prevalence of AT deficiency in each country is important to organize the public health policy. The aim of this study is to determine the prevalence of AT deficiency in Turkish population and to define the cutoff value of AT level in serum to detect heterozygous AT deficient subjects. MATERIALS AND METHODS: Serum samples from 1,203 healthy blood donors were used, attending the Blood Bank of Hacettepe Medical Faculty. Isoelectric focusing method for determining PIM, PIS, and PIZ alleles and rate immune nephelometry for measuring the level of AT in serum were used. RESULTS: Out of 1,203 healthy blood donors enrolled, 1,164 (%96.8) had normal variant PI MM allelee, 9 (%0.7) PI MZ, 7 (%0.6) PI MS, 6 (%0.5) MF, and 17 (%1.4) PI M? (unidentified variants with existing standards). Most individuals (89.6%) with low AT level (cutoff <100 mg/dl) in serum were positive for PI MM allele. The cutoff value to investigate PI MZ was 100.5 mg/dl, which had PPV and NPV of 5.0 and 99.9%, respectively. AT deficiency is a rare hereditary disorder in asymptomatic healthy Turkish blood donors. Although the cutoff value of 100.5 mg/dl for AT level in serum was able to detect heterozygous AT deficiency in the healthy population, this finding should be conformed to case-control studies.

The Effect of Pubertal Stage on the Concentrations of the Novel Adipomyokine, Irisin, in Male Adolescents

Objective: Irisin is a recently discovered protein and is defined as an adipomyokine. The relation of irisin with carbohydrate metabolism and other hormone parameters have been investigated. However, studies evaluating the relationship between irisin and puberty are limited and inconclusive. The aim was to evaluate serum concentrations of irisin during different pubertal stages in male adolescents. Methods: The study included normal weight pubertal male adolescents between the ages of 136/12-1411/12 who had entered puberty. Fasting serum irisin concentrations were evaluated, and bioelectrical impedance analysis was used to measure body fat ratio (BFR) and fat-free mass (FFM). BFR was also calculated by caliper measurement of subcutaneous fat at the triceps. Results: Sixty-eight adolescents were enrolled. The number of adolescents in pubertal stage 2, 3, 4 and 5 were n=17 (25%), n=13 (19.1%), n=21 (30.1%) and n=17 (25%), respectively. The median values of the irisin are 8.80, 8.20, 9.15 and 7.24 ng/mL according to the 2-5 pubertal stages, respectively. The levels of circulating irisin did not differ according to the pubertal stage. Additionally, there was no significant relationship between irisin levels and body fat percentage or FFM. Conclusion: Irisin levels do not differ after the onset of puberty or with progressing pubertal maturation. This study strengthens the evidence that there is no change in irisin concentration as puberty progresses. This may have important implications when using this adipomyokine in the future for diagnosis or treatment of obesity-related diseases.

Assessment of the results of a three-year program for National Standardization and Quality Improvement of Medical Laboratories on Drug of Abuse Testing by the Ministry of Health in Turkey.

The aim of this study is to assess the results of inspections in the last three years of drug abuse testing in medical laboratories according to the latest regulations in Turkey. The on-site inspections of medical laboratories for drugs abuse testing performed in Alcohol and Drug Addiction Treatment Centers during 2014-2016 are described, and laboratory processes and performance evaluated. The performance of 35 laboratories in 2014, 62 laboratories in 2015, and 94 laboratories in 2016 were scored as the sum of the scores for all answers on the inspection form. An inspected laboratory was considered to have an unconformity if the total score was less than 2/3 of maximum score. The total scores of inspections and the number of laboratories with between years were compared using one-way analysis of variance and slope Chi-square for trend test, respectively. Total scores increased statistically significantly from 35.9 ± 16.2 in 2014, to 43.5 ± 16.3 in 2015 and 49.1 ± 1.3 in 2016 (p < 0.001). The laboratories with unconformities decreased statistically significantly from 57% in 2014 to 37% in 2015 and 22% in 2016 (p < 0.001). The published legislation and the inspections contributed to national standardization and improved quality of service in medical laboratories for drug abuse testing.

Lower bone mineral density in geriatric patients with monoclonal gammopathy of undetermined significance.

The aim of this study was to investigate the prevalence of monoclonal gammopathy of undetermined significance (MGUS) in a geriatric population in Turkey and compare bone mineral densities and related laboratory parameters of MGUS patients with those who do not have MGUS. Among 1,012 patients enrolled, monoclonal band was detected in serum samples of 22 patients (2.17%), most of which were IgG type. Further tests revealed multiple myeloma and lung carcinoma in two patients. The remaining 20 patients were diagnosed with MGUS (1.97%). The clinical and laboratory parameters of patients with and without MGUS were mostly comparable; however, bone mineral density measurements of patients with MGUS were significantly lower than those without MGUS (p = 0.007). We suggest evaluation of geriatric patients with MGUS for the presence of osteopenia/osteoporosis considering the high frequency observed in this study.

Heat shock protein70: a new marker for subsequent atrial fibrillation development?

Atrial fibrillation (AF) is a common arrhythmia, after cardiac surgery, and it is associated with a twofold increase in cardiovascular mortality and morbidity. Reperfusion injury and inflammation associated with cardiac surgery are thought to be involved in its pathogenesis. Heat shock proteins (HSPs) are a family of chaperone proteins which assist in preservation of cellular integrity by maintaining proteins in their correctly folded state. The aim of this study was to investigate pre-postoperative heat shock protein70 (HSP70) and high-sensitivity C-reactive protein in serum from patients in preoperative sinus rhythm. We prospectively screened 45 consecutive patients admitted to the hospital for elective coronary artery bypass surgery (CABG). Electrocardiogram characteristics and cardiovascular risk profile were documented. Pre- and postoperative blood samples were collected. HSP70 value was 8.9 +/- 4.8 ng/mL in Group A (study group) preoperatively and decreased to 7.7 +/- 7.0 ng/mL postoperatively. In contrast, preoperative value of HSP70 was 4.2 +/- 2.2 ng/mL and decreased to 2.7 +/- 2.6 ng/mL postoperatively in Group B (control group). Statistical analysis showed significant difference regarding preoperative HSP70 levels in Group A compared to Group B. To our knowledge, with this study, the association of pre- and postoperative circulating HSP70 with postoperative AF was demonstrated for the first time.

Dipeptidyl peptidase IV (DDP IV) in NASH patients.

OBJECTIVE(S): Non-alcoholic steatohepatitis (NASH) is a chronic liver disease with unknown etiology. The insulin resistance, immune mechanisms and oxidative stress are the main factors in its pathogenesis. Dipeptidyl peptidase IV (DPPIV) or CD26 is a protein with endocrine and immune functions. This study aimed to elicudate the changes related to DPPIV in NASH patients. METHODS: Serum and urinary DPPIV activities were measured in 31 NASH patients and 17 healthy controls. The liver biopsies of 29 patients were immunolabeled for CD26. RESULTS: The mean age of patients were 46 +/- 11 years and 14 (45%) of them were female. The serum DPPIV activity was higher in patients (57.3 +/- 7.8 U/L) than controls (43.6 +/- 10.6 U/L) (p < 0.0001), and correlated with the histopathological grade (p = 0.038, r = 0.373) and hepatosteatosis (p = 0.018, r = 0.423) but not with stage (p = 0.286), class (p = 0.286) or CD26 staining (p = 0.743). The urinary DPPIV activity was similar in patients (1.52 +/- 0.94 U/mmol creatinine) and controls (1.37 +/- 0.68 U/mmol creatinine) (p = 0.861). Three acinar zones of liver had equal CD26 expression (p = 0.076). The intensity of CD26 immunostaining was correlated with histopathological grade (p = 0.001) and hepatosteatosis (p = 0.003) but no correlation with stage or class could be detected (p = 0.610 and 0.956, respectively). In CONCLUSIONS: The serum DPPIV activity and the staining intensity of CD26 in liver are correlated with histopathologic grade of NASH and hepatosteatosis. DPPIV can be proposed as a novel candidate with several potential functions in NASH pathogenesis.

Oral and dental findings in children with Fanconi anemia.

PURPOSE: The purpose of this study was to investigate the oral and dental findings in children with Fanconi anemia (FA). METHODS: The study included 26 FA patients who came to the hospital (Hacettepe University Faculty of Medicine, Pediatric Hematology Unit) from the central region of Anatolia (17 [65%] mole, 9 [35%] female; mean age = 10.0 +/- 5.2 years (range = 2-18; median = 9 years]). Oral and radiological examinations and salivary collection were performed at the Department of Pediatric Dentistry of Hacettepe University Faculty of Dentistry. RESULTS: Among 26 FA children: (a) 16 (62%) had never visited a dentist; (b) 6 (23%) had visited a dentist once; and (c) 4 (15%) had visited a dentist regularly. Furthermore: (a) only 5 children (19%) brushed their teeth regularly; (b) 7 (27%) had never brushed their teeth previously; and (c) the other 14 (54%) had brushed their teeth rarely. The prevalence of dental caries was 35% in this study's patients. Gingival examination revealed that 9 (35%) children had gingivitis and the other 17 (65%) had normal gingival health status. Examination of the oral cavity revealed that: (a) 3 children (12%) had a coated tongue; and (b) 1 (4%) had papillary atrophy. No leukoplakia or other precancerous lesion was detected in this patient group. Salivary flow rate was less than 0.7 ml/minute in 56% of the patients. No patients had a salivary pH less than 5. Salivary buffering capacity of less than 5, however, was detected in 5 patients (33%). Radiological evaluation revealed that the most common congenital dental abnormalities were: (1) microdontia (44%); (2) congenitally missing teeth (26%); (3) transposition (9%); and (4) supernumerary teeth (4%). CONCLUSION: These results demonstrate that poor oral hygiene, dental decay, gingivitis, and congenital dental abnormalities--including generalized microdontia, supernumerary teeth, transposition, and congenitally missing teeth--are common oral and dental findings in this group of Turkish children with Fanconi anemia.

Heat shock protein 60 antibody. A new marker for subsequent atrial fibrillation development.

OBJECTIVE: To examined the pre- and post- operative anti-HSP60 antibodies of serum from patients in preoperative sinus rhythm. METHODS: We prospectively studied 45 consecutive patients admitted for elective CABG from 2004 to 2005. We randomly selected 10 patients developing AF (study sample [Group A]) and 10 postoperative patients without AF (control [Group B]. The study took place at the Department of Cardiovascular Surgery, Hacettepe University, Ankara, Turkey. RESULTS: Anti-HSP60 IgG value was 27.76 +/- 12.69 absorbance units (AU) in Group A preoperatively and decreased to 13.73 +/- 5.51 AU postoperatively. Controversially, preoperative value of anti-HSP60 IgG was 9.94 +/- 2.92 AU and decreased to 6.72 +/- 1.89 AU, postoperatively in Group B. Statistical analysis showed significant difference regarding preoperative anti-HSP60 IgG levels in Group A compared to Group B, which might be interpreted as an association between postoperative AF and preoperative levels of anti-HSP60 IgG. CONCLUSION: We provide the first evidence demonstrating the association of pre- and post- operative circulating anti-HSP60 antibodies with postoperative AF. These results suggest that serum HSP60 antibody levels may be a marker for subsequent development of AF.

[The Scope, Quality and Safety Requirements of Drug Abuse Testing]. / Yasadisi ve Kötüye Kullanilan Madde Analizlerinin Kapsami, Kalite ve Güvenlik Gereklilikleri.

The aim of this review is to inform about the scopes and requirements of drug abuse testing. Drug abuse testing is one of the tools for determination of drug use. It must fulfill the quality and safety requirements in judgmental legal and administrative decisions. Drug abuse testing must fulfill some requirements like selection of the appropriate test matrix, appropriate screening test panel, sampling in detection window, patient consent, identification of the donor, appropriate collection site, sample collection with observation, identification and control of the sample, specimen custody chain in preanalytical phase; analysis in authorized laboratories, specimen validity tests, reliable testing METHODS, strict quality control, two-step analysis in analytical phase; storage of the split specimen, confirmation of the split specimen in the objection, result custody chain, appropriate cut-off concentration, the appropriate interpretation of the result in postanalytical phase. The workflow and analytical processes of drug abuse testing are explained in last regulation of the Department of Medical Laboratory Services, Ministry of Health in Turkey. The clinical physicians have to know and apply the quality and safety requirements in drug abuse testing according to last regulations in Turkey.

Highly selective enrichment of phosphopeptides by titanium (IV) attached monodisperse-porous poly(vinylphosphonic acid-co-ethylene dimethacrylate) microspheres.

A seeded polymerization protocol was developed for the synthesis of monodisperse-porous poly(vinylphosphonic acid-co-ethylene dimethacrylate), [poly(VPA-co-EDMA)] microspheres with superior porous properties. The protocol allowed the direct synthesis of phosphonic acid functionalized porous microspheres with the mean size of ∼4µm and the specific surface area of 420m2g-1 without applying any complicated post-derivatization protocol for the attachment of phosphonic acid group. The phosphonic acid content of poly(VPA-co-EDMA) microspheres was determined as 1.5mmol H2PO3g-1 microspheres. Ti(IV) ions were attached onto the microspheres via metal-chelate complex formation by phosphonate-groups and Ti(IV) carrying monodisperse-porous poly(vinylphosphonic acid-co-ethylene dimethacrylate), [Ti(IV)@poly(VPA-co-EDMA)] microspheres were obtained as a new sorbent for phosphopeptide enrichment via immobilized metal affinity chromatography. The phosphopeptides in the enriched samples were identified by matrix-assited laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Four different phosphopeptides were detected with extremely high intensity by the treatment of ß-casein digest prepared with the concentration of 10 fmol/mL with Ti(IV)@poly(VPA-co-EDMA) microspheres. Highly selective enrichment of phosphopeptides was also successfully carried out even at trace amounts in a complex mixture of digested proteins (molar ratio of ß-casein to BSA, 1:1000) and eight different phosphorylated peptides from BSA digest were successfully identified. Moreover, four highly intense signals of the phosphopeptides in human serum were observed with high S/N ratio and clear background after enrichment by using Ti(IV)@poly(VPA-co-EDMA) microspheres.

Ti(IV) carrying polydopamine-coated, monodisperse-porous SiO2 microspheres with stable magnetic properties for highly selective enrichment of phosphopeptides.

A marked decrease in the saturation magnetization by the formation of functional shells around the magnetic core is an important disadvantage of magnetic core-shell nanoparticles. Another drawback of Ti(IV)-functionalized immobilized metal affinity chromatography (IMAC) sorbents is the acidic character of the binding medium used for Ti4+ attachment onto composite magnetic nanoparticles, which causes an additional decrease in the saturation magnetization owing to the chemical interaction between the acidic moiety and the magnetic core. An IMAC sorbent in the form of magnetic microspheres with superior and stable magnetic properties with respect to magnetic core-shell nanoparticles was designed for phosphopeptide enrichment. Magnetic, monodisperse-porous silica microspheres (MagSiO2) 6µm in size were synthesized by a new staged-shape template hydrolysis-condensation protocol. A porous-silica shell layer was generated around the microspheres to protect the magnetic core from the acidic medium during Ti4+ attachment (MagSiO2@SiO2). The MagSiO2@SiO2 microspheres were coated with a polydopamine shell (MagSiO2@SiO2@PDA) and Ti4+ was attached onto the composite microspheres (MagSiO2@SiO2@PDA@Ti(IV)). Formation of the PDA layer and Ti4+ attachment did not cause any significant decrease in the saturation magnetization. The platform exhibited excellent performance for phosphopeptide enrichment from the digests of phosphorylated proteins. Selectivity was investigated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The detection limit for phosphopeptide enrichment by the MagSiO2@SiO2@PDA@Ti(IV) microspheres from the tryptic digests of ß-casein was 50 fmol/mL. Usability of the proposed magnetic sorbent with complex biological samples was demonstrated by successful enrichment of four phosphopeptides from human serum. The proposed sorbent showed stable performance over five repeated uses.

A Boronate Affinity-Assisted SERS Tag Equipped with a Sandwich System for Detection of Glycated Hemoglobin in the Hemolysate of Human Erythrocytes.

Phenylboronic acid-functionalized, Ag shell-coated, magnetic, monodisperse polymethacrylate microspheres equipped with a glycoprotein-sensitive sandwich system were proposed as a surface-enhanced Raman scattering (SERS) substrate for quantitative determination of glycated hemoglobin (HbA1c). The magnetization of the SERS tag and the formation of the Ag shell on the magnetic support were achieved using the bifunctional reactivity of newly synthesized polymethacrylate microspheres. The hemolysate of human red blood cells containing both HbA1c and nonglycated hemoglobin was used for determination of HbA1c. The working principle of the proposed SERS tag is based on the immobilization of HbA1c by cyclic boronate ester formation between glycosyl residues of HbA1c and boronic acid groups of magnetic polymethacrylate microspheres and the binding of p-aminothiophenol (PATP)-functionalized Ag nanoparticles (Ag NPs) carrying another boronic acid ligand via cyclic boronate ester formation via unused glycosyl groups of bound HbA1c. Then, in situ formation of a Raman reporter, 4,4'-dimercaptoazobenzene from PATP under 785 nm laser irradiation allowed for the quantification of HbA1c bound onto the magnetic SERS tag, which was proportional to the HbA1c concentration in the hemolysate of human erythrocytes. The sandwich system provided a significant enhancement in the SERS signal intensity due to the plasmon coupling between Ag NPs and Ag shell-coated magnetic microspheres, and low HbA1c concentrations down to 50 ng/mL could be detected. The calibration curve obtained with a high correlation coefficient between the SERS signal intensity and HbA1c level showed the usability of the SERS protocol for the determination of the HbA1c level in any person.