Records of iodine isotopes (129I, 127I) in the Barkol peat bog from northwest China and their sources, transport and preservation

The research on geochemical behaviors of iodine is significant for deep understanding of the source and distribution of iodine on the earth. However, as one of the most important sources, the ocean emissions and relative transport pathways of iodine, as well as the preservation after deposition are still not well known, especially in the arid areas of central Asia. A peat sediment core collected nearby Barkol Lake from northwest China was analyzed for iodine isotopes (¹²⁷I and ¹²⁹I). The observed high ¹²⁷I concentration in the top 2 cm indicated a significant accumulation of iodine in the surface oxic conditions due to the continuous sources of incompletely decomposed organic matter. Dissociation of iodine into pore waters occurred once the anoxic conditions established beneath the surface by a serial reduction reaction during the degradation of organic matter. The temporal variation of anthropogenic ¹²⁹I in the peat sediment recorded its sources and transport pathways. Besides the global fallout ¹²⁹I during late 1950s and early 1960s, the significantly increased air releases from the European nuclear fuel reprocessing plants during 1975-1997 and the increased marine discharges since 1990s contributed the major portion of ¹²⁹I in the peat core. The major transport pathway of ¹²⁹I from the Europe was through Westerlies following the re-emission of the marine discharged ¹²⁹I to the atmosphere, indicating a clearly ocean emitted iodine in the concerned central Asia.

Kinetic and solvent isotope effects in oxidation of halogen derivatives of tyramine catalyzed by monoamine oxidase A

The isotope effects approach was used to elucidate the mechanism of oxidative deamination of 3'-halotyramines, catalyzed by monoamine oxidase A (EC 1.4.3.4). The numerical values of kinetic isotope effect (KIE) and solvent isotope effect (SIE) were established using a non-competitive spectrophotometric technique. Based upon KIE and SIE values, some of the mechanistic details of investigated reaction were discussed.

[Efficacy and dosimetric analysis of (125)I seeds implantation for pelvic recurrent cervical cancer after radiotherapy under CT guidance]

Objective: To evaluate the relationship of dosimetry parameters and efficacy of (125)I seeds implantation for pelvic recurrent cervical cancer (PRCC) after external beam radiotherapy(EBRT) under CT guidance. Methods: A retrospective analysis was made on 30 PRCC patients after EBRT in Peking University Third Hospital with (125)I seeds implantation under CT guidance. Postoperative plans were made to evaluate the dosimetric parameters. Kaplan-Meier method was used to calculate local progression free survival (LPFS) rate and overall survival (OS) rate, and Log-rank test and Cox regression were used for univariate and multivariate analysis. Results: The 1-year and 2-year LPFS rate was 39.4% and 22.5%, respectively. The 1-year and 2-year OS rate was 57.3% and 27.4%, respectively. On postoperative plan, D(90) was (132±47) Gy, D(100) was (51±24) Gy, V(100) was 88%±10%, V(150)was 69%±15%, V(200) was 51%±18%.LPFS time would be longer while D(90) ≥105 Gy or D(100) ≥ 55 Gy or V(100) ≥ 91% (all P<0.05). D(100) was significantly related to LPFS (P<0.05). But these dosimetry parameters got no effect on OS. Conclusions: LPFS time of (125)I seeds implantation for PRCC after EBRT under CT guidance would be longer when D(90)≥105 Gy or D(100)≥ 55 Gy, or V(100)≥ 91%. D(100) is an independent factor related to LPFS.

Malignant Malanoma of the Penis

In a series of 720 malignant melanomas there was one case of primary malignant melanoma of the penis, in a 43-year old patient. He was subjected to total amputation of the organ together with the inguino-iliac lymph nodes and endolymphatic radiotherapy with 131I Lipiodol.

Dietary Iodine Exposure and Brain Structures and Cognition in Older People. Exploratory Analysis in the Lothian Birth Cohort 1936

BACKGROUND

Iodine deficiency is one of the three key micronutrient deficiencies highlighted as major public health issues by the World Health Organisation. Iodine deficiency is known to cause brain structural alterations likely to affect cognition. However, it is not known whether or how different (lifelong) levels of exposure to dietary iodine influences brain health and cognitive functions.

METHODS

From 1091 participants initially enrolled in The Lothian Birth Cohort Study 1936, we obtained whole diet data from 882. Three years later, from 866 participants (mean age 72 yrs, SD±0.8), we obtained cognitive information and ventricular, hippocampal and normal and abnormal tissue volumes from brain structural magnetic resonance imaging scans (n=700). We studied the brain structure and cognitive abilities of iodine-rich food avoiders/low consumers versus those with a high intake in iodine-rich foods (namely dairy and fish).

RESULTS

We identified individuals (n=189) with contrasting diets, i) belonging to the lowest quintiles for dairy and fish consumption, ii) milk avoiders, iii) belonging to the middle quintiles for dairy and fish consumption, and iv) belonging to the middle quintiles for dairy and fish consumption. Iodine intake was secured mostly though the diet (n=10 supplement users) and was sufficient for most (75.1%, median 193 µg/day). In individuals from these groups, brain lateral ventricular volume was positively associated with fat, energy and protein intake. The associations between iodine intake and brain ventricular volume and between consumption of fish products (including fish cakes and fish-containing pasties) and white matter hyperintensities (p=0.03) the latest being compounded by sodium, proteins and saturated fats, disappeared after type 1 error correction.

CONCLUSION

In this large Scottish older cohort, the proportion of individuals reporting extreme (low vs. high)/medium iodine consumption is small. In these individuals, low iodine-rich food intake was associated with increased brain volume shrinkage, raising an important hypothesis worth being explored for designing appropriate guidelines.

EXTRAVASCULAR AND INTRATUBULAR DIFFUSION OF LABELED SERUM PROTEINS IN THE RAT TESTIS

Rat whole serum, albumin, globulins, and fibrinogen were labeled with fluorescent dyes (sulforhodamine B. CI No. 45100 and fluorescein isothiocyanate); albumin was also tagged with radioactive iodine (I131) and tritium (H3). In addition heterologous albumin was also labeled with fluorescent dyes and radioiodine. The proteins were intravenously injected in prepubertal, pubertal and adult rats, and their decay in the circulation and histological distribution in the testis and epididymis was studied. As controls other animals were similarly injected with free labels alone and with labeled denatured and degraded albumin; also unlabeled homologous and heterologus albumins were administered followed by incubation of both organs with the corresponding labeled antisera applying the Coons' technique. It was observed: 1) with the exception of fibrinogen, labeled serum proteins rapidly appeared in the lumina of vessels, diffused extravascularly in the intertubular spaces and finally arrived inbetween the germinal cells and in the lumina of seminiferous tubules. Also labeled material was present in the lumen of epididymal canaliculi but not in the ductus deferens. 2) This extravascular and intratubular diffusion was parallel to the fast component of the time decline curve of labeled homologous serum proteins in the circulation. 3) There was no great difference between young and adult rats in the extravascular diffusion process, but intratubular passage was higher in pubertal and adult animals. 4) Control experiments revealed time presence of some fluorescent material only in the vessels and macrophages, whereas the immunofluorescent technique showed to very similar localization of unlabeled proteins to that provided by the injection of directly labeled proteins.

Observation of the Intracellular Behavior of RecombinantYersinia pseudotuberculosisInvasin Protein

In this study, we observed the intracellular behavior of recombinant invasin, a 103-kDa outer membrane protein of Yersinia pseudotuberculosis. To mimic the in vivo behavior of bacterial invasin, a polyvalent form of invasin was generated by incubation of biotinylated GST-fused invasin C-terminal portion protein (GST-INVS) with avidin. Several experiments confirmed that the recombinant invasin could consistently reproduce the invasin-mediated entry to mammalian epithelial cells. We analyzed the molecular kinetics of polyvalent INVS by western blotting, (125) I-uptake, and immunofluorescent microscopy. The internalized polyvalent INVS was rapidly translocated to the RIPA-insoluble (polymerized-actin enriched) fraction and formed cytoplasmic vesicles, while monovalent invasin did not show such kinetics. From these observations, we concluded that our bacterial-free system is able to analyze the action of invasin for Yersinia pseudotuberculosis entry.

Binding of the radioligand SIL23 to α-synuclein fibrils in Parkinson disease brain tissue establishes feasibility and screening approaches for developing a Parkinson disease imaging agent

Accumulation of α-synuclein (α-syn) fibrils in Lewy bodies and Lewy neurites is the pathological hallmark of Parkinson disease (PD). Ligands that bind α-syn fibrils could be utilized as imaging agents to improve the diagnosis of PD and to monitor disease progression. However, ligands for α-syn fibrils in PD brain tissue have not been previously identified and the feasibility of quantifying α-syn fibrils in brain tissue is unknown. We report the identification of the (125)I-labeled α-syn radioligand SIL23. [(125)I]SIL23 binds α-syn fibrils in postmortem brain tissue from PD patients as well as an α-syn transgenic mouse model for PD. The density of SIL23 binding sites correlates with the level of fibrillar α-syn in PD brain tissue, and [(125)I]SIL23 binding site densities in brain tissue are sufficiently high to enable in vivo imaging with high affinity ligands. These results identify a SIL23 binding site on α-syn fibrils that is a feasible target for development of an α-syn imaging agent. The affinity of SIL23 for α-syn and its selectivity for α-syn versus Aβ and tau fibrils is not optimal for imaging fibrillar α-syn in vivo, but we show that SIL23 competitive binding assays can be used to screen additional ligands for suitable affinity and selectivity, which will accelerate the development of an α-syn imaging agent for PD.

Is knowledge important? Empirical research on nuclear risk communication in two countries

Increasing audience knowledge is often set as a primary objective of risk communication efforts. But is it worthwhile focusing risk communication strategies solely on enhancing specific knowledge? The main research questions tackled in this paper were: (1) if prior audience knowledge related to specific radiation risks is influential for the perception of these risks and the acceptance of communicated messages and (2) if gender, attitudes, risk perception of other radiation risks, confidence in authorities, and living in the vicinity of nuclear/radiological installations may also play an important role in this matter. The goal of this study was to test empirically the mentioned predictors in two independent case studies in different countries. The first case study was an information campaign for iodine pre-distribution in Belgium (N = 1035). The second was the information campaign on long-term radioactive waste disposal in Slovenia (N = 1,200). In both cases, recurrent and intensive communication campaigns were carried out by the authorities aiming, among other things, at increasing specific audience knowledge. Results show that higher prior audience knowledge leads to more willingness to accept communicated messages, but it does not affect people’s perception of the specific risk communicated. In addition, the influence of prior audience knowledge on the acceptance of communicated messages is shown to be no stronger than that of general radiation risk perception. The results in both case studies suggest that effective risk communication has to focus not only on knowledge but also on other more heuristic predictors, such as risk perception or attitudes toward communicated risks.

An NMR thermometer for cryogenic magic-angle spinning NMR: the spin-lattice relaxation of (127)I in cesium iodide

The accurate temperature measurement of solid samples under magic-angle spinning (MAS) is difficult in the cryogenic regime. It has been demonstrated by Thurber et al. (J. Magn. Reson., 196 (2009) 84-87) [10] that the temperature dependent spin-lattice relaxation time constant of (79)Br in KBr powder can be useful for measuring sample temperature under MAS over a wide temperature range (20-296 K). However the value of T(1) exceeds 3 min at temperatures below 20K, which is inconveniently long. In this communication, we show that the spin-lattice relaxation time constant of (127)I in CsI powder can be used to accurately measure sample temperature under MAS within a reasonable experimental time down to 10 K.

Expression of benign and malignant thyroid tissue in ovarian teratomas and the importance of multimodal management as illustrated by a BRAF-positive follicular variant of papillary thyroid cancer

BACKGROUND

The most common type of ovarian germ cell tumor is the teratoma. Thyroid tissue, both benign and malignant, may be a component of an ovarian teratoma. Here we review this topic and illustrate major features by presenting multimodal management of a patient with BRAF-positive disseminated follicular thyroid cancer arising in an ovarian teratoma.

SUMMARY

Malignant thyroid tissue is often difficult to distinguish from benign thyroid tissue arising in ovarian teratomas. Preoperatively, an elevated thyroglobulin (Tg) level, laboratory or clinical evidence of hyperthyroidism, or ultrasonography appearance of "struma pearl" should prompt referral to oncologist for surgical management of a possibly malignant ovarian teratoma. Postoperatively, tumor tissue should be referred to pathologists experienced with differentiating benign from malignant struma ovarii. Once diagnosed, treatment of this rare condition should be handled by a team of specialists with combined treatment modalities. We cared for woman with disseminated thyroid cancer arising in an ovarian teratoma whose history illustrates the complexity of managing ovarian teratomas with malignant thyroid tissue. At age 33 she had an intraoperative rupture of an ovarian cyst, thought to be struma ovarii. During her next pregnancy, pelvic masses were noted; biopsies revealed well-differentiated papillary thyroid carcinoma, follicular variant. She was euthyroid, but had elevated serum Tg levels. Surgical staging demonstrated widely metastatic intraabdominal dissemination. A thyroidectomy revealed no malignancy. A post-(131)I treatment scan revealed diffuse uptake throughout the abdomen. She then developed abdominal pain and, on computed tomography, was found to have multiple intraabdominal foci of disease. Serum Tg was 264 ng/mL while on L-thyroxine for hypothyroidism and to obtain thyrotropin suppression. A 18 fluorodeoxyglucose positron emission tomography scan showed no pathological uptake. The tumor was found to be BRAF mutation positive (K601E). She underwent extensive secondary debulking and a second course of (131)I with lithium pretreatment. Posttreatment scan revealed diffuse abdominal uptake. Six months posttherapy, the patient is asymptomatic with a serum Tg of 18.1 ng/mL.

CONCLUSIONS

Aggressive multimodal management appears to be the most promising approach for malignant thyroid tissue arising in ovarian teratomas.