Development of a new thiol-reactive prosthetic group for site-specific labeling of biomolecules with radioactive iodine

In this report, we describe the radiosynthesis of a new thiol-targeting prosthetic group for efficient radioactive iodine labeling of biomolecules. Radioiodination using the precursor 3 was performed to obtain ¹²⁵I-labeled tetrazole 4b with high radiochemical yield (73%) and radiochemical purity. Using the radiolabeled 4b, a single free cysteine containing peptide and human serum albumin were labeled with ¹²⁵I in modest-to-good radiochemical yields (65-99%) under mildly reactive conditions. A biodistribution study of [¹²⁵I]7 in normal ICR mice exhibited lower thyroid uptake values than those of ¹²⁵I-labeled human serum albumin prepared via a traditional radiolabeling method. Thus, [¹²⁵I]7 could be employed as an effective radiotracer for molecular imaging and biodistribution studies. The results clearly demonstrate that 4b has the potential to be effectively implemented as a prosthetic group in the preparation of radiolabeled biomolecules.

An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter

Here, we demonstrate a detail protocol for the preparation of nanomaterials-embedded composite membranes and its application to the efficient and ion-selective removal of radioactive iodines. By using citrate-stabilized gold nanoparticles (mean diameter: 13 nm) and cellulose acetate membranes, gold nanoparticle-embedded cellulose acetate membranes (Au-CAM) have easily been fabricated. The nano-adsorbents on Au-CAM were highly stable in the presence of high concentration of inorganic salts and organic molecules. The iodide ions in aqueous solutions could rapidly be captured by this engineered membrane. Through a filtration process using an Au-CAM containing filter unit, excellent removal efficiency (>99%) as well as ion-selective desalination result was achieved in a short time. Moreover, Au-CAM provided good reusability without significant decrease of its performances. These results suggested that the present technology using the engineered hybrid membrane will be a promising process for the large-scale decontamination of radioactive iodine from liquid wastes.

Diagnostic accuracy of glypican-3 in differentiating hepatocellular carcinoma from metastatic liver tumours

OBJECTIVE

To determine the diagnostic accuracy of Glypican-3 in differentiating hepatocellular carcinoma from metastatic liver tumours while taking histopathology as the gold standard..

METHODS

The cross-sectional study was conducted at Shaukat Khanum Memorial Cancer Hospital, Lahore, Pakistan, from January 1 to June 30, 2016, and comprised cases of malignant liver tumours. Samples were collected from the pathology department. Glypican-3was applied on them. Tumours were classified as positive when they showed >5% positivity and negative when showing <5% positivity. Frequencies and percentages of cases showing GPC3 positivity and negativity along with frequency and percentages of hepatocellular carcinoma and metastatic tumours were calculated.

RESULTS

Of the 240 patients, 143(59.58%) were males and 97 (40.42%) were females. Overall mean age was 54.65 ± 13.46 years. On histopathology, 134 cases were hepatocellular carcinoma (55.83%) and 106 (44. 17%) cases turned out to be metastatic carcinoma. Glypican-3staining was positive in 116 (48.33%) cases and negative in 124(51.67%). Sensitivity was 82%, Specificity 94.33%, positive predictive value 94.82% and negative predictive value 80.64%. Diagnostic accuracy was 87.5%.

CONCLUSIONS

Glypican-3 was found to be a highly sensitive and specific Immunohistochemistry stain distinguishing hepatocellular carcinoma from the clear majority of metastatic carcinomas of the liver.

Efficient and Site-Specific 125I-Radioiodination of Bioactive Molecules Using Oxidative Condensation Reaction

In this report, the novel and site-specific radioiodination of biomolecules by using aryl diamine and alkyl aldehyde condensation reaction in the presence of a Cu²⁺ catalyst under ambient conditions was reported. ¹²⁵I-labeled alkyl aldehyde was synthesized using a tin precursor with a high radiochemical yield (72 ± 6%, n = 5) and radiochemical purity (>99%). The utility of the radioiodinated precursor was demonstrated through aryl diamine-installed c[RGDfK(C)] peptide and human serum albumin (HSA). Radioiodinated c[RGDfK(C)] peptide and HSA protein were synthesized with high radiochemical yields and purity. ¹²⁵I-HSA protein showed excellent in vivo stability and negligible thyroid uptake as compared with directly radioiodinated HSA by using the tyrosine group. Excellent reaction kinetics and the in vitro and in vivo stabilities of ¹²⁵I-labeled alkyl aldehyde have suggested the usefulness of the strategy for the radioiodination of bioactive molecules.

Fluorescence in Situ Hybridization (FISH) for Differential Diagnosis of Soft Tissue Sarcomas

Introduction:

Soft tissue sarcomas are rare tumors comprising 1 percent of solid malignancies. The latest edition of WHO soft tissue pathology lists 94 benign and malignant soft tissue tumors. Many of these show a large degree of morphological overlap. Immunohistochemistry has been shown to be reliable in many cases for differential diagnosis of lesions, although cytogenetic tests are considered the gold standard for many entities.Fluorescence in-situ hybridization (FISH) is a cytogenetic technique that uses fluorescent probes that bind to only those parts of the chromosome which have a high degree of sequence complementarity. Many soft tissue tumors show recurrent genetic mutations that are now being used as diagnostic markers. Knowledge of the molecular identity allows prediction of behavior, prognosis and treatment response.

Objective:

The aim of this study was to identify genetic mutations in soft tissue sarcomas using FISH testing and to assess correlations with histological diagnosis.

Material and methods:

A total of 25 cases of different soft tissue sarcomas diagnosed on histology with the help of immunohistochemical staining and for which FISH studies were requested were included in this study. Three pathologists with a special interest in soft tissue sarcomas reviewed the cases. FISH tests for EWS, the X:18 translocation, FOXO1 and MDM2 were respectively applied for 8 cases of Ewing sarcoma, 8 cases of synovial sarcoma, 2 cases of rhabdomyosarcoma and 7 cases of dedifferentiated liposarcoma and atypical lipomatous tumors/well differentiated liposarcomas.

Results:

EWS gene fusion was detected in 7 out of 8 cases of Ewing sarcoma and the X: 18 translocation was positive in 3 of the 8 cases of synovial sarcoma. FOXO1 was not detected in either of the two rhabdomyosarcomas. MDM2 by FISH was detected in only one out of 5 cases of atypical lipomatous tumors and 1 out of 2 dedifferentiated liposarcomas.

Conclusion:

FISH is a useful adjunct in the diagnostic assessment of different types of soft tissue sarcomas. It is easy to set up, is relatively inexpensive and has the ability to diagnose sarcomas with great accuracy, especially in cases which can not be accurately classified even after thorough histological and immunohistochemical evaluation. It may play a very important role in the accurate diagnosis and correct management of patients.

Radiolabeling and preliminary biodistribution study of 99mTc-labeled antibody-mimetic scaffold protein repebody for initial clearance properties

Antibody-mimetic proteins are intensively being developed for biomedical applications including tumor imaging and therapy. Among them, repebody is a new class of protein that consists of highly diverse leucine-rich repeat (LRR) modules. Although all possible biomedical applications with repebody are ongoing, it's in vivo biodistribution and excretion pathway has not yet been explored. In this study, hexahistidine (His₆)-tag bearing repebody (rEgH9) was labeled with [^99mTc]-tricarbonyl, and biodistribution was performed following intravenous (I.V.) or intraperitoneal (I.P.) injection. Repebody protein was radiolabeled with high radiolabeling efficiency (>90%) and radiolabeled compound was more than 99% pure after purification. Biodistribution data indicates radiotracer has a rapid clearance from blood and excreted through the kidneys for intravenous (I.V.) injection, but comparatively slow clearance for an intraperitoneal (I.P.) injection. SPECT-CT images were found to be in agreement with biodistribution data, high activity was found inside kidneys. The observed result for rapid blood clearance and renal excretion of repebody (rEgH9) provide useful information for the further development of therapeutic strategy.

Discovery of anti-microbial and anti-tubercular molecules from Fusarium solani: an endophyte of Glycyrrhiza glabra

AIMS

Glycyrrhiza glabra is a high-value medicinal plant thriving in biodiversity rich Kashmir Himalaya. The present study was designed to explore the fungal endophytes from G. glabra as a source of bioactive molecules.

METHODS AND RESULTS

The extracts prepared from the isolated endophytes were evaluated for anti-microbial activities using broth micro-dilution assay. The endophytic strain coded as A2 exhibiting promising anti-bacterial as well as anti-tuberculosis activity was identified as Fusarium solani by ITS-5.8S ribosomal gene sequencing technique. This strain was subjected to large-scale fermentation followed by isolation of its bioactive compounds using column chromatography. From the results of spectral data analysis and comparison with literature, the molecules were identified as 3,6,9-trihydroxy-7-methoxy-4,4-dimethyl-3,4-dihydro-1H-benzo[g]isochromene-5,10-dione (1), fusarubin (2), 3-O-methylfusarubin (3) and javanicin (4). Compound 1 is reported for the first time from this strain. All the four compounds inhibited the growth of various tested bacterial strains with MIC values in the range of <1 to 256 μg ml^-1 . Fusarubin showed good activity against Mycobacterium tuberculosis strain H37Rv with MIC value of 8 μg ml^-1 , whereas compounds 1, 3 and 4 exhibited moderate activity with MIC values of 256, 64, 32 μg ml^-1 , respectively.

CONCLUSIONS

To the best of our knowledge, this is the first study that reports significant anti-tuberculosis potential of bioactive molecules from endophytic F. solani evaluated against the virulent strain of M. tuberculosis. This study sets background towards their synthetic intervention for activity enhancement experiments in anti-microbial drug discovery programme.

SIGNIFICANCE AND IMPACT OF THE STUDY

Due to the chemoprofile variation of same endophyte with respect to source plant and ecoregions, further studies are required to explore endophytes of medicinal plants of all unusual biodiversity rich ecoregions for important and or novel bioactive molecules.

Efficient bioremediation of radioactive iodine using biogenic gold nanomaterial-containing radiation-resistant bacterium, Deinococcus radiodurans R1

A new bioremediation method is developed by using a gold nanomaterial-containing radiation-resistant bacterium.

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group

Here, we demonstrate a detailed protocol for the radiosynthesis of a ¹²⁵I-labeled azide prosthetic group and its application to the efficient radiolabeling of DBCO-group-functionalized gold nanoparticles using a copper-free click reaction. Radioiodination of the stannylated precursor (2) was carried out by using [¹²⁵I]NaI and chloramine T as an oxidant at room temperature for 15 min. After HPLC purification of the crude product, the purified ¹²⁵I-labeled azide (1) was obtained with high radiochemical yield (75 ± 10%, n = 8) and excellent radiochemical purity (>99%). For the synthesis of radiolabeled 13-nm-sized gold nanoparticles, the DBCO-functionalized gold nanoparticles (3) were prepared by using a thiolated polyethylene glycol polymer. A copper-free click reaction between 1 and 3 gave the ¹²⁵I-labeled gold nanoparticles (4) with more than 95% of radiochemical yield as determined by radio-thin-layer chromatography (radio-TLC). These results clearly indicate that the present radiolabeling method using a strain-promoted copper-free click reaction will be useful for the efficient and convenient radiolabeling of DBCO-group-containing nanomaterials.

Aggressive Disease Course of Papillary Thyroid Carcinoma with Focal Undifferentiated Component: A Case Report

We report an aggressive papillary thyroid carcinoma (PTC) with focal undifferentiated component in a 32-year-old female. She had limited disease confined within the thyroid gland at diagnosis. Within 12 months of thyroidectomy and radioiodine ablation, thyroglobulin (Tg) levels were elevated. Second radioiodine ablative dose was given, however, stimulated Tg levels showed an upward trend with negative iodine scan within 12 months. An ¹⁸F fludeoxyglucose-avid solitary pulmonary nodule that was detected on positron emission tomography/computed tomography scan was resected followed by empiric radioiodine therapy. Within the next 10 months she developed multifocal bone metastases. The multifocal disease was rendered inoperable and treated with external beam radiation. The patient is on follow-up, and the Tg level continues to rise with local disease progression. In a small percentage of patients, PTC behaves as a very aggressive disease despite treatment. Focally undifferentiated thyroid carcinoma is an expression of the extreme end of the spectrum of differentiated thyroid carcinoma.