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Journal of Radioanalytical and Nuclear Chemistry
Authors:
A. Perera Pintado
,
S. Mather
,
M. Stalteri
,
D. Allison
,
A. Prats Capote
,
A. Hernández Cairo
,
O. Reyes Acosta
, and
M. Bequet Romero

Abstract  

The aim of this work was to characterize the in vitro behavior of N4- and N3S-RGDS-derivative peptides labeled with 99mTc. Peptides AGGG-Abu-GRGDSPK-NH2 (F22) and C(acm)-GGG-Abu-GRGDSPK-NH2 (SMA1) were synthesized by solid phase. The stability of 99mTc-labeled peptides was assessed in a 30-fold molar excess of cysteine and in plasma. The affinity for plasma proteins was also evaluated. Labeling yield was >95% for both peptides. 99mTc-F22 was not stable in presence of cysteine, but 63% of 99mTc remained chelated to SMA1 up to 24 hours. Both peptides showed low affinity to plasma proteins. N3S-RGDS-derivative peptide (SMA1) showed more stable coordination binding with 99mTc and a higher stability in plasma with regard to N4-RGDS-derivative peptide (F22).

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
M. Suzarte
,
N. Rodríguez
,
J. Oliva
,
N. Iznaga
,
A. Perera
,
A. Morales
,
N. Gonzalez
,
O. Torres
, and
T. Rodríguez

Abstract  

Monoclonal antibody ior egf/r3 is a IgG2a, recognizes the epidermal growth factor receptor. The aim of the present work was to evaluate the diagnostic efficacy of the99mTc-labeled ior egf/r3 for the detection of epithelial tumors, its metastasis and its recurrences. The sensitivity by organs was: brain 100%, diegestive tract 90%, head and neck 89%, lung 84% and breast 79%. The overall sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the immunoscintigraphic imaging were 84.1%, 100%, 86.5%, 100% and 52.4%, respectively. Immunoscintigraphy with99mTc-ior egf/r3 is useful for the diagnosis and follow-up of epithelial tumors.

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Journal of Thermal Analysis and Calorimetry
Authors:
Lakshmi Kaza
,
Hany F. Sobhi
,
Jeffrey A. Fruscella
,
Chris Kaul
,
Shravan Thakur
,
Naullage I. Perera
,
Kenneth Alexander
, and
Alan T. Riga

Abstract

A standard protocol was developed to determine the water content by thermal analysis of milk of magnesia (MoM). Differential scanning calorimetry (DSC) and thermogravimetry (TG) were used in a novel manner for examining the physical characteristics of the commercial pharmaceutical suspensions. Moisture analyzer and oven-dry methods validate the proposed protocol. MoM consists primarily of water and magnesium hydroxide [Mg(OH)2]. Experimental design of the thermal analysis parameters were considered including sample size, flowing atmosphere, sample pan, and heating rate for both DSC and TG. The results established the optimum conditions for minimizing heat and mass transfer effect. Sample sizes used were: (5–15 mg) for DSC and (30–50 mg) for TG. DSC analysis used crimped crucibles with a pinhole, which allowed maximum resolution and gave well-defined mass (water) loss. TG analysis used a heating rate of 10 °C/min−1 in an atmosphere of nitrogen. The heat of crystallization, heat of fusion, and heat of vaporization of unbound water are 334, 334, and 2,257 Jg−1, respectively (Mitra et al. Proc NATAS Annu Conf Therm Anal Appl 30:203–208, 2002). The DSC average water content of (MoM) was 80 wt% for name brand and 89.5 wt% for generic brand, based on the relative crystallization, melting and vaporization heats/Jg−1 of distilled water in the recently purchased (2011) MoM samples. The TG showed a two-step process, losing water at 80–135 °C for unbound water and bound water (MgO·H2O) at 376–404 °C, yielding a total average water loss of 91.9 % for name brand and 90.7 % for generic brand by mass. The difference between the high-temperature TG and the lower-temperature DSC can be attributed for the decomposition of magnesium hydroxide or MgO·H2O. Therefore in performing this new approach to water analysis by heating to a high temperature decomposed the magnesium hydroxide residue. It was determined that the TG method was the most accurate for determining bound and unbound water.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
A. Perera
,
C. Perez
,
M. Torres
,
A. Henandez
,
F. Heres
,
T. Moreira
,
A. Gutierrez
,
A. Gigato
,
I. Hernandez
,
L. Alberti
,
O. Marrero
,
L. Martinez
,
J. Sanfiz
,
E. Sanchez
,
J. Rodriguez
,
L. Marrero
, and
G. Parra

Abstract  

The aim of this work was to obtain a freeze-dried kit for direct99mTc-labeling of human polyclonal IgG. The labeling procedure was carried out by Schwarz's method. The best yields of99mTc-IgG were obtained by using sodium pyrophosphate decahydrate as a weak chelating agent. Performed tests showed the stability of the radiopharmaceutical up to 24 hours. Plasma clearance in rats was fitted to a biexponential curve withT 1/2α=(0.1 ±0.9) h andT 1/2β=(10±3) h. The organs with higher uptake of radiopharmaceutical were lung, kidneys and blood. In a rabbit model the abscess target/background ratio was 3–6 according to time of the scintigraphic images. Thirty patients with musculoskeletal infection were studied. Twenty-one lesions were detected and confirmed by culture/biopsy.

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