Phase I Clinical Trial Using [99mTc]Tc-1-thio-D-glucose for Diagnosis of Lymphoma Patients.

Similar to [18F]-FDG, [99mTc]Tc-1-thio-D-glucose ([99mTc]Tc-TG) also binds to GLUT receptors. The aim of this Phase I study was to evaluate the safety, biodistribution and dosimetry of [99mTc]Tc-TG. Twelve lymphoma patients were injected with 729 ± 102 MBq [99mTc]Tc-TG. Whole-body planar imaging was performed in 10 patients at 2, 4, 6 and 24 h after injection. In all 12 patients, SPECT/CT (at 2 h) and SPECT (at 4 and 6 h) imaging was performed. Vital signs and possible side effects were monitored during imaging and up to 7 days after injection. [99mTc]Tc-TG injections were well-tolerated and no side effects or alterations in blood and urine analyses data were observed. The highest absorbed dose was in the kidneys and urinary bladder wall, followed by the adrenals, prostate, bone marrow, lungs, myocardium, ovaries, uterus, liver and gall bladder wall. [99mTc]Tc-TG SPECT/CT revealed foci of high activity uptake in the lymph nodes of all nine patients with known nodal lesions. Extranodal lesions were detected in all nine cases. In one patient, a lesion in the humerus head, which was not detected by CT, was visualized using [99mTc]Tc-TG. Potentially, [99mTc]Tc-TG can be considered as an additional diagnostic method for imaging GLUT receptors in lymphoma patients.

Factors influencing the attenuation of serotype 1 Marek's disease virus by serial cell culture passage and evaluation of attenuated strains for protection and replication.

This study was carried out to better understand factors that influenced the process of attenuation of Marek's disease (MD) virus by serial passage in cell cultures. Three virulent (v) pathotype and three very virulent plus (vv+) pathotype strains were passed by three techniques up to 131 times, and the passage level at attenuation was determined. The 18 attenuated or partially attenuated viruses were evaluated for protection against challenge with virulent MD virus, and the virus load (latent infection) in blood lymphocytes at 14-21 days postvaccination was determined. Viral pathotype strongly influenced the rate of attenuation. The mean passage level at attenuation for v and vv+ strains was 74 and >109, respectively. Full attenuation was achieved for nine of nine passage series with v pathotype strains but for only four of nine passage series with vv+ pathotype strains. Time to attenuation was not significantly influenced by multiplicity of infection at passage or by cell type, although a possible advantage of alternate high- and low-multiplicity passage was noted. Protection was not significantly influenced by pathotype or time to attenuation. Protection varied from 50% to 95% for the 18 passaged virus preparations; six attenuated viruses provided high protection that did not differ from that of the prototype Rispens strain. Virus load was not influenced by pathotype or by passage strategy and showed no positive correlation with protection. In several cases the most protective vaccines had the least virus load. This finding differs from previous reports and warrants further study. Variation among different strains within the same pathotype was documented for attenuation rate, protection, and virus load. Also, variation was evident when the same strain was passaged by different strategies, probably reflecting random changes during serial passage. Strain 596A (v pathotype) was the first to become attenuated, provided the best protection, and had one of the lowest virus loads. In contrast, strain 617A (v pathotype) provided the least protection and had one of the highest virus loads. Such strains provide fertile opportunities for further study.

Evaluation of Marek's disease field isolates by the "best fit" pathotyping assay.

Although determination of the pathotype is central to the study of Marek's disease (MD) field isolates, methods are not standardized and results from different laboratories may not compare well with the original Avian Disease and Oncology Laboratory assay. This study was designed to investigate the validity of the "best fit" pathotyping assay, a simplified method recently described for testing of field isolates of MD virus (MDV). Twenty serotype 1 MDV strains were isolated from 12 breeder and commercial flocks in eight regions of the Russian Federation and were pathotyped by the best fit assay using vaccinated and non-vaccinated chickens from Schelkovo specific pathogen free breeders. Lesion responses induced by field isolates were compared with those induced by reference strains JM/102W, Md5, and 648A representing pathotypes v, vv and vv+, respectively. Based on comparison with reference strains, we determined the pathotype of eight isolates as vv+, 11 isolates as vv and one isolate as v. Lesion responses induced by the three reference strains consistently differentiated the respective pathotypes in non-vaccinated chickens and in chickens vaccinated with FC126 (serotype 3) alone or with a bivalent FC126 + 301B/1 vaccine (serotypes 3 and 2, respectively). Variation between reference strain responses in replicate trials was minimal. In some cases, calculation of the proportional distance between pairs of reference strains aided in the classification of field isolates. These results indicate that the "best fit" pathotyping assay can be conducted with local chicken strains and, in the absence of statistical analysis, provides pathotype designations that are consistent with those obtained by the Avian Disease and Oncology Laboratory method. In addition, the pathogenicity of Russian isolates appeared comparable with that of United States isolates.