Practical and theoretical considerations for the determination of δ13 CVPDB values of methylmercury in the environment.

RATIONALE: Analytical methods that can identify the source and fate of mercury and organomercury compounds are likely to be useful tools to investigate mercury in the environment. Carbon isotope ratio analysis of methylmercury (MeHg) together with mercury isotope ratios may offer a robust tool to study environmental cycling of organomercury compounds within fish tissues and other matrices. METHODS: MeHg carbon isotope ratios were determined by gas chromatography/combustion-isotope ratio mass spectrometry (GC/C-IRMS) either directly or following derivatization using sodium tetraethylborate. The effects of a normalization protocol and of derivatization on the measurement uncertainty of the methylmercury δ13 CVPDB values were investigated. RESULTS: GC/C-IRMS analysis resulted in a δ13 CVPDB value for an in-house MeHg reference material of δ13 CVPDB = -68.3 ± 7.7‰ (combined standard uncertainty, k = 1). This agreed very well with the value obtained by offline flow-injection analysis/chemical oxidation/isotope ratio mass spectrometry of δ13 CVPDB = -68.85 ± 0.17‰ (combined standard uncertainty, k = 1) although the uncertainty was substantially larger. The minimum amount of MeHg required for analysis was determined to be 20 µg. CONCLUSIONS: While the δ13 CVPDB values of MeHg can be obtained by GC/C-IRMS methods with or without derivatization, the low abundance of MeHg precludes such analyses in fish tissues unless there is substantial MeHg contamination. Environmental samples with sufficient MeHg pollution can be studied using these methods provided that the MeHg can be quantitatively extracted. The more general findings from this study regarding derivatization protocol implementation within an autosampler vial as well as measurement uncertainty associated with derivatization, normalization to reporting scales and integration are applicable to other GC/C-IRMS-based measurements.

Prospective evaluation of complications in laparoscopic urology at a mid-volume institution using standardized criteria: Experience of 1023 cases including learning curve in 9 years.

AIM: To evaluate the laparoscopic operations performed in our department according to the modified Clavien classification system of complications. MATERIALS AND METHODS: Between September, 2005 and February, 2014, a total of 1023 laparoscopic cases were performed. This period was divided into three terms (Terms 1, 2 and 3 consisting of 38, 32 and 32 months, respectively). According to the European Scoring System (ESS), easy (E), slightly difficult (SD), fairly difficult (FD), difficult (D), very difficult (VD) and extremely difficult (ED) cases were 35, 88, 170, 390, 203 and 137, respectively. The perioperative complications were evaluated based on the 3 time periods, with a specific emphasis on determining the learning curve according to the modified Clavien classification system of complications. RESULTS: A total of 236 (23.1%) complications were observed according to the modified Clavien classification. The minor (Clavien I-II) and major (Clavien III, IV and V) complication rates were 20.5% (n = 210) and 2.4% (n = 26), respectively. Clavien I was the most frequently encountered type of complication (n = 120, %11.7). No significant difference was observed among all 3 time periods regarding total complication rates. The D cases had the highest complication rate compared to E, SD, FD, VD and ED cases among all three terms. The total number of complications increased significantly with increasing grade of technical difficulty according to the ESS. CONCLUSION: Complications encountered in our laparoscopic surgery experience were predominantly minor, and the rate of complications was not significantly increased during the learning curve. The present data can provide guidance and manage expectations for surgeons introducing laparoscopy into their practice.

International system of units traceable results of Hg mass concentration at saturation in air from a newly developed measurement procedure.

Data most commonly used at present to calibrate measurements of mercury vapor concentrations in air come from a relationship known as the "Dumarey equation". It uses a fitting relationship to experimental results obtained nearly 30 years ago. The way these results relate to the international system of units (SI) is not known. This has caused difficulties for the specification and enforcement of limit values for mercury concentrations in air and in emissions to air as part of national or international legislation. Furthermore, there is a significant discrepancy (around 7% at room temperature) between the Dumarey data and data calculated from results of mercury vapor pressure measurements in the presence of only liquid mercury. As an attempt to solve some of these problems, a new measurement procedure is described for SI traceable results of gaseous Hg concentrations at saturation in milliliter samples of air. The aim was to propose a scheme as immune as possible to analytical biases. It was based on isotope dilution (ID) in the liquid phase with the (202)Hg enriched certified reference material ERM-AE640 and measurements of the mercury isotope ratios in ID blends, subsequent to a cold vapor generation step, by inductively coupled plasma mass spectrometry. The process developed involved a combination of interconnected valves and syringes operated by computer controlled pumps and ensured continuity under closed circuit conditions from the air sampling stage onward. Quantitative trapping of the gaseous mercury in the liquid phase was achieved with 11.5 µM KMnO4 in 2% HNO3. Mass concentrations at saturation found from five measurements under room temperature conditions were significantly higher (5.8% on average) than data calculated from the Dumarey equation, but in agreement (-1.2% lower on average) with data based on mercury vapor pressure measurement results. Relative expanded combined uncertainties were estimated following a model based approach. They ranged from 2.2% to 2.8% (k = 2). The volume of air samples was traceable to the kilogram via weighing of water for the calibration of the sampling syringe. Procedural blanks represented on average less than 0.1% of the mass of Hg present in 7.4 cm(3) of air, and correcting for these blanks was not an important source of uncertainty.

Obstructive sleep apnoea syndrome in patients with primary open-angle glaucoma.

OBJECTIVE: To investigate the prevalence of obstructive sleep apnoea syndrome in patients with primary open-angle glaucoma. DESIGN: Case series. SETTING: School of Medicine, Düzce University, Turkey. PATIENTS: Twenty-one consecutive primary open-angle glaucoma patients (12 females and 9 males) who attended the out-patient clinic of the Department of Ophthalmology between July 2007 and February 2008 were included in this study. All patients underwent polysomnographic examination. RESULTS: The prevalence of obstructive sleep apnoea syndrome was 33.3% in patients with primary open-angle glaucoma; the severity of the condition was mild in 14.3% and moderate in 19.0% of the subjects. The age (P=0.047) and neck circumference (P=0.024) in patients with obstructive sleep apnoea syndrome were significantly greater than those without the syndrome. Triceps skinfold thickness in glaucomatous obstructive sleep apnoea syndrome patients reached near significance versus those without the syndrome (P=0.078). Snoring was observed in all glaucoma cases with obstructive sleep apnoea syndrome. The intra-ocular pressure of patients with primary open-angle glaucoma with obstructive sleep apnoea syndrome was significantly lower than those without obstructive sleep apnoea syndrome (P=0.006 and P=0.035 for the right and left eyes, respectively). There was no significant difference in the cup/disc ratio and visual acuity, except visual field defect, between primary open-angle glaucoma patients with and without obstructive sleep apnoea syndrome. CONCLUSIONS: Although it does not provide evidence for a cause-effect relationship, high prevalence of obstructive sleep apnoea syndrome in patients with primary open-angle glaucoma in this study suggests the need to explore the long-term results of coincidence, relationship, and cross-interaction of these two common disorders.

LKB1 mutations and their correlation with LKB1 and Rheb expression in bladder cancer.

Although there are extensive studies on the genetics of bladder cancer, several questions remain unanswered. One of the pathways which are altered in bladder cancer is the mTOR signaling pathway. In the present study, we analyzed the expression of Rheb gene and genetic alterations in the LKB1 gene which are the key components of mTOR pathway. Nine exons of the LKB1 gene were analyzed by direct sequencing in 51 bladder cancer patients. To investigate the expression of Rheb and LKB1, real-time quantitative RT-PCR was performed in bladder tumor and normal bladder tissue samples. We did not observed a statistically significant difference in Rheb or LKB1 expression between the tumor and normal tissue samples. We detected a novel missense mutation creating stop codon in a high percent of the tumor samples. Five different single nucleotide substitutions were also observed in the introns. Our results indicate that LKB1 gene may play a role in the progression of bladder cancer.

Future prospects in the diagnosis and management of localized prostate cancer.

Prostate cancer (PCa) is the commonest visceral cancer in men worldwide. Introduction of serum PSA as a highly specific biomarker for prostatic diseases has led to a dramatic increase in the diagnosis of early stage PCa in last decades. Guidelines underline that benefits as well as risks and squeals of early diagnosis and treatment should be discussed with patients. There are several new biomarkers (Pro-PSA, PCA-3 test, and TMPRSS2-ERG) available on the market but new ones are awaited in order to improve specificity and sensitivity. Investigators have also focused on identifying and isolating the gene, or genes, responsible for PCa. Current definitive treatment options for clinically localized PCa with functional and oncological success rates up to 95% include surgery (radical prostatectomy), external-beam radiation therapy, and interstitial radiation therapy (brachytherapy). Potential complications of overdiagnosis and overtreatment have resulted in arguments about screening and introduced a new management approach called "active surveillance." Improvements in diagnostic techniques, especially multiparametric magnetic resonance imaging, significantly ameliorated the accuracy of tumor localization and local staging. These advances will further support focal therapies as emerging treatment alternatives for localized PCa. As a conclusion, revolutionary changes in the diagnosis and management of PCa are awaited in the near future.

Premacular hemorrhage due to isotretinoin use.

Isotretinoin is a vitamin A derivative used for serious acne that is refractory to other modes of treatment. The most common side effects include dryness of the skin and mucous membranes. Itching as a result of neurological, hematological and ocular side effects has also been reported. Here, we present a 19-year-old female patient who developed premacular hemorrhage and consequent loss of vision in the left eye after oral use of isotretinoin. To the best of our knowledge, this is the first report of the development of premacular hemorrhage as a result of isotretinoin use.

Use of a combined retroperitoneoscopic and transperitoneal laparoscopic technique for the management of renal cell carcinoma with level I tumor thrombi.

BACKGROUND: To report our initial experiences using a combined retroperitoneoscopic and transperitoneal laparoscopic technique for the management of renal cell carcinoma with level I tumor thrombi. MATERIALS AND METHODS: Two patients underwent this technique for tumors 11- and 13-cm in diameter. After transection of the renal artery with limited mobilization of the kidney using a retroperitoneoscopic approach, additional ports were placed, and the management of the tumor thrombus was performed in the large working space provided by the transperitoneoscopic approach. RESULTS: The technique was feasible in the present 2 cases. The total operative times were 170 and 200 min, respectively. The estimated blood loss was 450 cc in the first case and 200 cc in the second case. No complications were observed in either of the patients. CONCLUSIONS: Based on the initial clinical experience, we have presented a feasible surgical option for the laparoscopic management of renal cell carcinoma with level I thrombi.

Unilateral Multiple Evanescent White Dot Syndrome-Like Reaction Following the CyberKnife Stereotactic Radiotherapy for Choroidal Malignant Melanoma.

A 58-year-old otherwise healthy man received a diagnosis of choroidal malignant melanoma (CMM) in June 2021 and underwent a single session of (21 Gy) CyberKnife stereotactic radiotherapy (SRT). Eleven months later, we noticed 3+ anterior chamber cells with occasional vitreous cells in the left eye. Though the tumor looked regressed, there were mild optic disc leakage, early hypofluorescent and late hyperfluorescent punctate lesions scattered 360 degrees, and late staining of the mass on fluorescein angiogram. The findings were compatible with a unilateral multiple evanescent white dot syndrome (MEWDS)-like reaction that was most likely related to CyberKnife SRT-induced tumor necrosis, and a dexamethasone implant was administered intravitreally into the left eye together with topical steroids. A second intravitreal injection of dexamethasone was given three months later due to remittance of the angiographic features. As there are only a few reports on CyberKnife SRT for the treatment of CMM, we wanted to share our interesting observation of a post-treatment MEWDS-like reaction likely related to tumor necrosis syndrome with the ophthalmic community.

Ground temperature estimations for Bolu, Turkey.

The approximation of the soil temperature profile may be considered for many energy, environmental, and agriculture applications. In this study, temperature approximation model of ground in Bolu is developed. Unsteady state one-dimensional semi-infinite solid model is used to calculate temperature variation in ground. The results of the temperature equation which are obtained by using analytical method are compared with experimental data obtained from The Turkish State Meteorological Service. Developed model to predict soil temperature variation for Bolu has been solved by using MATLAB computer program. Satisfactory agreement is observed between them.

The first case of primary testicular germ cell tumor containing nephroblastoma as the only one non-germ cell component.

Adult extrarenal nephroblastomas (Wilms' tumor) are extremely rare tumors. They show a higher incidence of non-seminomatous elements and these so-called 'teratoid' Wilms' tumors are suggested to be of germ cell origin. To date, however, the number of reported cases with gonadal teratoma containing nephroblastoma is very low, and due to this reason, there are no standardized criteria for the categorization and treatment of these lesions. To our knowledge, the first case of nephroblastoma arising in a non-atrophic testis has been reported and it is associated with a teratoma as morphologically identifiable germ cell tumor and rhabdomyosarcoma as a second non-germ cell element. We report the second case of an adult nephroblastoma that arose within the primary testicular teratoma in a non-atrophic testis. Teratoma and nephroblastoma within the same testis may have an important point to clarify the developmental mechanism in nephroblastomatous differentiation of germ cell tumors.

Quantification of tributyltin in seawater using triple isotope dilution gas chromatography-inductively coupled plasma mass spectrometry achieving high accuracy and complying with European Water Framework Directive limits.

A triple isotope dilution GC-ICPMS method for the determination of tributyltin (TBT) was developed and validated to meet the European Water Framework Directive (WFD) requirements. The validation procedure involved the evaluation of trueness, precision (repeatability, intermediate precision), limit of detection (LOD) and limit of quantification (LOQ), stability, measurement uncertainty and traceability studies. The method is one of the most sensitive methods published to date with good accuracy, 103% average recovery in the range with %RSDs of 2.8-6.7%. A LOD value of 0.015 ng L-1 for the TBT cation was achieved with a sample volume of 12 mL seawater. TBT was derivatized using 20 µL sodium tetraethylborate solution (0.05% NaBEt4) to make volatile for GC-ICPMS. Measurement uncertainty was in the range of 4.8-13% which was achieved through dissolution of tributyltinchloride (TBTCl) in 1-propanol, a low-volatility solvent combined with the use of a triple isotope dilution (ID) calibration technique. Isotope dilution calibration was performed by adding 117Sn isotopically enriched TBT to the seawater samples. The stability test results showed that TBT concentration was stable for three months in seawater samples after passing through a 0.2 µm filter and stored in amber glass bottles at 4°C. The response surface methodology (RSM) approach was successfully implemented to provide optimal conditions for large volume injection (LVI) to obtain the maximum analytical signal. The key variables selected in the experimental design were evaporation time, evaporation temperature, carrier flow, and injection speed. This method was applied to seawater samples collected from the Bay of Izmit, Kocaeli, Turkey, where TBT pollution has not been measured yet.

CyberKnife Stereotactic Radiotherapy in Secondary Vasoproliferative Tumor of the Retina.

A 16-year-old boy with X-linked retinoschisis was examined for the visual decline on his left eye. Upon examination, a vasopermeable elevated mass lesion was determined at the lower temporal retinal periphery associated with surrounding arc-like hard exudates which is consistent with a vasoactive proliferative tumor of the retina. After discussing the therapeutic options with the patient and his parents, 3 successive dexamethasone implants 6 months apart were administered. As no satisfactory regression was noticed, CyberKnife stereotactic radiosurgery (SRS) was performed. Regression of the exudative tumor was obtained in follow-up examinations at 12 and 24 months after the SRS session and the thickness of the lesion was markedly reduced.

Laparoscopic nephrectomy in patients undergoing hemodialysis treatment.

BACKGROUND AND OBJECTIVES: To report our experience with laparoscopic nephrectomy (LN) in patients undergoing hemodialysis compared with normal counterparts. METHODS: Seventeen patients (20 renal units, Group 1) undergoing hemodialysis underwent LN, which was indicated due to nonfunctioning kidney in 17 and suspected malignancy in 3 renal units. Radical nephrectomy (RN), simple nephrectomy (SN), and simple nephroureterectomy (SNU) were performed in 3, 9, and 8 cases, respectively. For comparison, 101 patients (Group 2) without CRF (chronic renal failure) who had undergone LN were evaluated. In this group, RN, SN, SNU and radical nephroureterectomy (RNU) were performed in 48, 41, 8, and 4 patients, respectively. RESULTS: The mean age (36.9 ±13.1 vs. 48.7±19.4yr, P=0.002) and BMI (22.1±4.8 vs. 26.2±5.1kg/m(2), P=0.001) were lower in Group 1, whereas ASA (physical status score of American Society of Anesthesiologists) score (2.8±0.4 vs. 1.5±0.7, P<0.001) was lower in Group 2. The estimated blood loss (111±114 vs. 184±335mL, P=0.34) was higher in Group 2. Both groups were comparable in regard to mean operative time (133±79 vs. 119±45, P±0.70), hematocrit drop (4.69±3.9 vs. 3.86±3.0, P=0.29) and hospital stay (3.6±3.3 vs. 3.3±2.4 days, P=0.34). Meanwhile, when only patients undergoing SN and SNU in the study cohort (n=17 in Group 1 and n=49 in Group 2) are taken into consideration, no significant difference was observed between the 2 groups in terms of any kind of above-mentioned perioperative parameters. No case in Group 1 was converted to open surgery due to metabolic problems. CONCLUSIONS: LN in patients undergoing hemodialysis may be performed safely by an experienced laparoscopy team.

Hyperbaric Oxygen: an important treatment modality in severe hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation.

OBJECTIVE: Hemorrhagic cystitis (HC) is a generally self-limited complication of hematopoietic stem cell transplantation (HSCT). It may occur in the early or late posttransplant period and can promote sometimes severe morbidity. We analyzed our data regarding HC in allogeneic HSCT patients in order to establish the efficacy of hyperbaric oxygen (HBO) therapy in severe HC and to document the main problems during its use. METHODS: Between March 1993 and August 2006, 161 patients received allogeneic HSCT. Mesna, hyperhydration and forced diuresis were used as early HC prophylaxis of cyclophosphamide-induced HC. However, HC was diagnosed in 49 of the 161 recipients and 17 of them were considered as severe HC. We analyzed their data retrospectively. RESULTS: Forced diuresis with hyperhydration (up to 8 L/day) and transfusion support to maintain a platelet count above 30x109/L were sufficient in 10 of the 17 patients with severe HC. Alternative therapies used included intravesical irrigation with formalin and prostaglandin (PG)F2 alpha and HBO, and HBO appeared to be the most useful among them. CONCLUSION: We conclude that HBO offers a noninvasive therapeutic alternative in the management of intractable HC in the HSCT setting.

A reversible thermosensitive adhesive for retinal implants: in vivo experience with plasma-deposited poly(N-isopropyl acrylamide).

PURPOSE: To study the in vivo effects of a thermosensitive retinal adhesive, plasma-polymerized N-isopropyl acrylamide (ppNIPAM), in rabbit eyes. METHODS: Parylene C(poly(monochloro-p-xylylene)) (20 microm) and poly(dimethyl siloxane) (PDMS) (> or =200 microm) coated with ppNIPAM were used as implant materials. Following pars plana vitrectomy (PPV), ppNIPAM coated parylene (n = 3) and PDMS (n = 3) implants were inserted over the retina in six rabbits. Baseline and follow-up imaging (color fundus photographs, fluorescein angiography, and optic coherence tomography [OCT]) and electroretinogram recordings were performed. Histologic evaluation was performed following enucleation at 6 weeks. RESULTS: Intraoperative retinal adhesion occurred in all eyes with ppNIPAM coated parylene and PDMS implants. Two eyes developed retinal tears during the implantation procedure and the ppNIPAM coated implants closed the retinal tears successfully preventing retinal detachment. OCT findings confirmed the retinal adhesion in all eyes. Four weeks after implantation one parylene and one PDMS implant detached partly from the retinal surface. Histology showed mild changes at the outer retinal segments. There was no evidence of ocular toxicity and inflammation. None of the eyes that had an implant covering the retinal tear developed a retinal detachment but had some inflammatory changes around the implants. CONCLUSIONS: ppNIPAM coated implants may provide retinal adhesion in vivo without measurable ocular toxicity in the short term. Covering a retinal tear, the ppNIPAM coated implants may prevent retinal detachment.

Primary urethral plasmacytoma: a case report and literature review.

Plasmacytomas of the urethra are extremely rare neoplasias; they may occur as isolated tumors or concomitantly with generalized multiple myeloma. Herein, we describe the clinical presentation and characteristics of a patient with primary plasmacytoma of the urethra. A 51-year-old man presented with terminal hematuria and a palpable penile mass. Magnetic resonance urethrography revealed a 3-cm long stenotic segment along which the urethral mucosa was found to be irregular. On urethroscopy, papillary mucosal projections extending to the presphincteric area were noted. Lesions were found to be composed primarily of neoplastic plasma cells capable of producing mainly lambda light chain. Upon diagnosis, the patient received external beam radiation therapy targeting the pelvic region. The lesion diminished in size progressively during the treatment course. He was disease-free after 6 months. Although it is a relatively rare disease, primary urethral plasmacystoma should be considered in the differential diagnosis of urethral tumors and radiation therapy should be an integral part of the treatment strategy.

The association between variant urothelial histologies, pathological stage and disease specific survival in patients with bladder cancer.

OBJECTIVE: We aimed to compare the oncological outcomes of patients with variant urothelial histologies (VH) with pure urothelial histology (PUH) in bladder cancer (BC) patients. MATERIAL AND METHODS: This study includes 223 patients who underwent radical cystectomies (RCs) between September 2006 and July 2016 with complete follow-up data A retrospective screening was performed to identify the patients with PUH and VH. The primary outcomes of interest were pathological stage of disease at RC and disease-specific survival (DSS). For comparison of categorical variables, Fisher's exact test and Pearson chi- square and for continuous variables Wilcoxon rank-sum and Mann-Whitney U tests were used. Kaplan-Meier (KM) method was used for survival analysis and log-rank test was used for comparison of survival rates. Predictors of survival were detected with mulitivariable Cox-proportional hazards model including the variables such as gender, age, existence of VH, lymph node dissection (LND) type and pathological stage of the disease. RESULTS: A moderate-degree correlation was detected between VH and pathological stages of RC (r=0.45, p<0.001). In PUH group, 39 (25.8%) of 151 patients died after a median follow-up of 20 (0-107) months; whereas 37 (51.4%) of 72 patients with VH died after a median follow-up of 16.5 (0-104) months (p<0.001). In terms of pathological stage, the number of patients with PUH and VH were at stages pT0-2 (n=100; 66.2% vs. n=19; 26.4%), pT3-4 (n=35; 23.2% vs. 38; 52.8%, and in 16 (10.6%) and 15 (20.8%) patients with LN positivity, respectively (p<0.001). KM survival analysis revealed a significantly decreased DSS in patients with VH compared to PUH (p<0.001). Meanwhile, pathological disease stage and existence of VH were found to be associated with decreased DSS in the multivariate model. CONCLUSION: The present study revealed that VH is associated with advanced pathological tumor stage at RC and decreased DSS compared to patients with PUH in patients with BC.

The effect of squamous and/or glandular differentiation on recurrence, progression and survival in urothelial carcinoma of bladder.

INTRODUCTION: The effects of squamous and/or glandular differentiation in urothelial carcinoma of bladder on recurrence, progression and survival rate were evaluated in this study. PATIENTS AND METHODS: Between 1998 and 2003, a total of 223 patients who had been treated with transurethral resection for bladder cancers were evaluated. The patients were divided into two groups as; Group I: tumor patients with squamous and/or glandular differentiation, Group II: patients without these findings. RESULTS: Histologically 189 (84.7%) were conventional urothelial carcinoma and 34 (15.2%) were tumors with squamous and/or glandular differentiation. The mean age of the patients was 64.4 +/- 12.7 (range 36-81) years. Survival rates within a period of 46.23 +/- 14.8 (12-67) months were 76.47% for Group I and 89.94% for Group II (P = 0.027). The stage distribution as pTa, pT1, and >/=pT2 was 2 (5.9%), 18 (52.9%), and 14 (41.2%) in Group I and 101 (53.4%), 51 (27%) and 37 (19.6%) in group II, respectively (P = 0.001). There was a statistically significant tendency towards higher stage at presentation in Group I and the grade distribution was significantly higher in Group I than Group II (P < 0.001). CONCLUSION: High recurrence rates and poor prognosis of these patients should be kept in mind in the follow-up period. In this respect, these patients should be followed up closely.