Wet chemical synthesis of TGA capped Ag2S nanoparticles and their use for fluorescence imaging and temperature sensing in living cells.

In this work, we describe a simple wet chemical route for preparing silver sulfide nanoparticles (Ag2S) encapsulated with thioglycolic acid (TGA). By using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDS) microanalysis, transmission electron microscopy (TEM), and dynamic light scattering (DLS), we have found that these nanoparticles were enrobed by TGA molecules and they have an Ag/S ratio nearly equal to 2.2 and a nearly spherical shape with two average size populations. Photoluminescence (PL) spectroscopy has shown that these nanoparticles are highly luminescent, photostable and photobleaching resistant and they emit in the first biologic window with a band peaking in the NIR region at 915 nm. We have demonstrated through a 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay protocol and using U-87 MG human living cells that these nanoparticles are biocompatible with a viability ratio higher than 80% for a concentration equal to 100 µg mL-1. By investigating the effect of pH, ionic strength and thermal quenching on the PL emission, we have shown that these nanoparticles provide a convenient stable tool to measure temperature in the biological range with a relative thermal sensitivity higher than 5% per °C and they may be used as suitable fluorescent probes for living cell imaging and intracellular temperature mapping.

[Evaluation of efficacy and clinical impact of 18F-FDG-PET in the diagnosis of recurrent medullary thyroid cancer with increased calcitonin and negative imaging test]. / Evaluación de la eficacia y del impacto clínico de la PET-18F-FDG en el diagnóstico de recurrencia del carcinoma medular de tiroides con calcitonina elevada y pruebas de imagen negativas.

AIM: To evaluate the efficacy and clinical impact of the FDG-PET in the diagnosis of suspicion of recurrence of medullary thyroid cancer (MTC) in patients with elevated serum calcitonin and negative imaging test. MATERIAL AND METHODS: We performed a retrospective study of 31 consecutive cases from february 2001 to october 2007 of 17 women and 14 men, mean age 56.2 years (range: 26-88), with anatomical-pathology diagnosis of medullary thyroid cancer and suspicion of recurrence due to abnormal elevation of calcitonin and negative imaging tests. All of the patients underwent whole body FDG-PET scan with a dedicated PET or PET-CT 60 minutes after intravenous injection of 333-434 MBq of (18)F-FDG. Results were confirmed by pathology study in 45.2% of the patients and by clinical follow-up with a mean of 4 years (range: 16 m-8 years) RESULTS: Sensitivity was 88%, specificity 84.6%, positive predictive value 88%, negative predictive value 84.6% and diagnostic accuracy 87%. The results of the FDG PET modified the therapeutic strategy in 14 cases (45.2%). A comparison was made of the mean values of calcitonin using the Student's "t" test between positive PET studies for the disease and negative ones. No significant differences were found (P=.3). CONCLUSIONS: In patients with MTC and suspected recurrence with elevated calcitonin and negative imaging test, the FDG is the best test for the diagnosis of occult recurrence in MTC with elevated calcitonin and negative imaging techniques with elevated clinical impact. It facilitates the therapeutic management of the patients with MTC recurrence, and should be included in the diagnosis algorithm in these patients.

[18F-FDG PET-CT in a case of solitary plasmacytoma of the soft palate]. / Tomografía por emisión de positrones con ¹8F-fluorodeoxy-glucosa en un caso de plasmocitoma solitario de paladar blando.

Solitary plasmacytoma is an uncommon tumor of plasma cells that can appear in the head and neck. It must be differentiated from multiple myeloma because of its initial presentation. A case of solitary plasmacytoma on the palate is presented. Furthermore, role of ¹8F-fluorodeoxyglucose Positron Emission Tomography (¹8F-FDG-PET) in its initial staging is analyzed.

[Clinical impact of FDG-PET in patients with suspected recurrent ovarian cancer]. / Impacto clínico de la PET-FDG en pacientes con sospecha de recurrencia de cáncer de ovario.

AIM: To evaluate the efficacy and clinical impact of FDG-PET in patients with suspected recurrent ovarian cancer. METHODS: Between October 2001 and October 2006, we retrospectively studied 49 FDG-PET performed in 40 women (age: 52.4 +/- 12.2 years) with ovarian cancer, who had suspicion of recurrent disease by positive morphologic imaging tests (MIT) or increased tumour markers and negative MIT. All patients underwent whole body FDG-PET after the injection of 370-434 MBq of (18)FDG. The results were confirmed by histology in 31 cases, and by clinical-radiological follow-up in 18. RESULTS: Prevalence of disease was 79.6 %. We obtained a global sensitivity and positive predictive value of 87.2 % and 87.2 %, and an accuracy of 79.6 %. Results led to a change in the patient's management in 25 cases (51 %). Subgroup results were: Sensitivity of 81.8 % in patients with increased tumour markers and negative MIT, and 89.3 % in patients with operable malignant lesions. CONCLUSIONS: FDG-PET has high sensitivity and clinical impact in patients with suspicion of recurrent ovarian cancer. Better results were obtained in patients with increased tumour markers and negative MIT.

Levels of heavy metals and metalloids in critically endangered Iberian lynx and other wild carnivores from Southern Spain.

The Iberian lynx (Lynx pardinus) is the most endangered felid in the world with a wild population which probably stands at less than 200 individuals inhabiting two areas in Southern Spain (Doñana and Sierra Morena) that are known to have been contaminated by heavy metals and metalloids due to a long history of mining activities. This contamination may pose a threat to long term conservation efforts and hence, the concentrations of seven elements (As, Se, Cd, Zn, Cu, Pb, Hg) were determined in the liver, muscle and bone of 9 lynx, as well as 17 red foxes (Vulpes vulpes), 11 Egyptian mongooses (Herpestes ichneumon), 4 common genets (Genetta genetta) and 1 Eurasian badger (Meles meles). The mean concentrations found were below the threshold levels indicative of chronic intoxication in all the species studied. In general, genet and red fox were species with the highest concentrations of several elements in Doñana, whilst Iberian lynx had the lowest levels of most of them. Lynx from Sierra Morena had significantly higher concentrations of bone Pb (2.05 microg/g d.w.) than those from Doñana (0.13 microg/g d.w.), probably due to the mineralised underlying geology and/or the abandoned mine workings in Sierra Morena. Egyptian mongoose presented liver concentrations of Hg up to 9.7 microg/g d.w. A strong relationship between Hg and Se levels was found in liver and muscle samples of all the studied species, especially in mongoose. In conclusion, levels of the studied elements do not appear to represent a significant threat for the lynx or for the other carnivores studied. However, given the critical status of the Iberian lynx, a continuous monitoring scheme remains necessary.

Transfer of lead from shot pellets to game meat during cooking.

We evaluated the transfer of Pb from shot to meat during the preparation of breasts of quails with 0, 1, 2 or 4 embedded Pb shot. A traditional Spanish recipe was used which utilizes vinegar during cooking to enhance the long-term preservation of the meat. The effect of the acidic conditions generated by the vinegar on Pb transfer was compared with the same recipe when the vinegar was substituted with water. The effect of up to 4 weeks of storage on Pb transfer has been also evaluated. The transfer of Pb from the embedded shot to the meat was much higher when cooking with vinegar than with water. However, the Pb transfer under acidic conditions did not increase significantly during long-term storage at room temperature. The consumption of only half a pickled quail per week with embedded shot may cause the provisional tolerable weekly intake (PTWI) of Pb by the Spanish consumer to be exceeded.

[F-18-fluordeoxyglucose positron emission tomography on patients with differentiated thyroid cancer who present elevated human serum thyroglobulin levels and negative I-131 whole body scan]. / PET con 18FDG en pacientes con cáncer diferenciado de tiroides que presentan niveles elevados de tiroglobulina sérica y rastreos con 131I negativos.

UNLABELLED: This study aimed to evaluate the role of Fluorine-18-fluorodeoxyglucose positron emission tomography (PET-FDG) in patients with elevated serum thyroglobulin (hTg) levels where thyroid cancer tissue does not concentrate radioiodine, rendering false-negative results on I-131 scanning. MATERIAL AND METHODS: Whole-body PET imaging using FDG was performed in 54 patients (37 female, 17 male) aged 17-88 years: 45 with papillary tumors and 9 with follicular tumors who were suspected of having recurrent thyroid carcinoma due to elevated thyroglobulin levels (hTg > 2 ng/ml) under thyroid-stimulating hormone (TSH > or = 30 microIU/ml) in whom the iodine scan was negative. All whole body scans were obtained with diagnostic doses (185 MBq). Whole body PET imaging was performed in fasting patients following i.v. administration of 370 MBq FDG while the patients were receiving full thyroid hormone replacement. Before PET, 99mTc methoxyisobutylisonitrile scintigraphy (99mTc-MIBI) was done in 14 patients and morphologic imaging in 26 by CT scan. RESULTS: Positive PET results confirmed the presence of hypermetabolic foci in 25/54 patients (46.29 %). Positive findings were found for PET-FDG in patients with hTg levels higher than 10 ng/ml receiving full thyroid hormone replacement. 99mTc-MIBI demonstrated lesions in 7/14 patients (50 %). PET-FDG and 99mTc-MIBI had congruent positive results in 4/7 patients. All the lesions found by CT were detected by PET-FDG, while recurrent disease was found in 12/21 patients with previous negative CT. CONCLUSIONS: These results suggest that PET-FDG seems to be a promising tool in the follow-up of thyroid cancer and should be considered in patients suffering from differentiated thyroid cancer with suspected recurrence and/or metastases by elevated thyroglobulin levels, and negative I-131 whole body scans. PET-FDG might be more useful at hTg levels > 10 ng/ml.

[Evaluation of efficacy and clinical impact of FDG-PET in patients with suspicion of recurrent colorectal cancer]. / Evaluación de la eficacia y del impacto clínico de la PET-FDG en pacientes con sospecha de recurrencia de cáncer colorrectal.

AIMS: To evaluate the utility and clinical impact of Positron Emission Tomography with FDG (FDG-PET) in patients with suspected recurrent colorectal cancer (RCR). MATERIALS AND METHODS: Eighty five (85) patients with suspicion of RCR (Group A: 35 for increased tumor markers and negative imaging tests, Group B: 25 operable malignant lesions and Group C: 25 with non-conclusive morphological tests) were studied retrospectively. In all patients a whole body scan was performed with FDG-PET. In 29 cases the results were confirmed by histology and clinical evolution (follow-up period > 12 months) and imaging test in 56. RESULTS: Prevalence of RCR was 89.4 %. FDG-PET was positive in 30/35 patients in Group A, with confirmation in 29 cases (PPV: 96.6 %) and 4/5 were true negative (TN) (NPV: 80 %). FDG-PET enabled surgery for 6 patients. In Group B, PET was positive in 22/25, and all of them had confirmation (PPV: 100 %) but surgery was performed in only 7 patients. NPV was 66.6 %. Out of the 25 cases of Group C, FDG-PET obtained 21 TP, 1 FP case, 1 TN, 2 FN, and was able to avoid surgery in 8 patients (PPV: 95.4 % and NPV: 33.3 %). Overall sensitivity, specificity, PPV, NPV and accuracy were 94.7 %, 77.7 %, 97.2 %, 63.3 % and 92.9 %, respectively. CONCLUSIONS: FDG-PET has high clinical impact in patients with suspicion of recurrent colorectal cancer, and should be incorporated in the diagnostic protocols before making a surgery decision.

[Recombinant human thyrotropin in the follow-up of patients with differentiated thyroid carcinoma]. / La TSH humana recombinante en el seguimiento de pacientes con cáncer diferenciado de tiroides.

PURPOSE: To determine the value of the use of radio-iodine scanning diagnostic and radio-iodine therapy during the follow-up of advanced differentiated thyroid cancer without stopping thyroid hormone suppression therapy. MATERIAL AND METHODS: We performed 7 radio-iodine scans and 4 radioiodine therapies in 5 men and 1 woman, aged 39 to 79 years. Five patients had papillary thyroid cancer and one follicular thyroid cancer. Human recombinant thyrotropin was given intramuscularly at a dose of 0.9 mg/ml once a day for two days. Twenty-four hours after the second dose, serum thyrotropin, thyroglobulin (Tg) and thyroglobulin autoantibodies were measured and each patient was given 2 mCi of 131I in postsurgery scans and 5 mCi of 131I in patients previously treated with 131I. Whole-body scans were obtained within 54 hours of injection and in the cases of diagnostic uncertainty a second scan was performed 72 hours after the injection. RESULTS: Four scans were positive and two were negative. One positive scan patient was not treated due to a serious clinical condition. An effective increase of serum TSH was observed in all 6 patients. Four patients had an effective increase of serum Tg; the other 2 cases had a decrease of serum Tg: One case was undifferentiated and in the other case the mass was smaller after surgery. CONCLUSIONS: rhTSH is an effective means of stimulating TSH levels and allowing scan and/or radioiodine treatment. rhTSH has no significant adverse effects. The use of rhTSH avoids all the disadvantages of hypothyroidism and maintains quality of life.