FDG PET/MRI examination of the body is routinely performed from the skull base to the mid thigh. Many types of brain abnormalities potentially could be detected on PET/MRI if the head was included. ...The objective of this study was therefore to identify and characterize brain findings incidentally detected on PET/MRI of the body with the head included.
We retrospectively identified 269 patients with FDG PET/MRI whole-body scans that included the head. PET/MR images of the brain were reviewed by a nuclear medicine physician and neuroradiologist, first individually and then concurrently. Both PET and MRI findings were identified, including abnormal FDG uptake, standardized uptake value, lesion size, and MRI signal characteristics. For each patient, relevant medical history and prior imaging were reviewed.
Of the 269 subjects, 173 were women and 96 were men (mean age, 57.4 years). Only the initial PET/MR image of each patient was reviewed. A total of 37 of the 269 patients (13.8%) had abnormal brain findings noted on the PET/MRI whole-body scan. Sixteen patients (5.9%) had vascular disease, nine patients (3.3%) had posttherapy changes, and two (0.7%) had benign cystic lesions in the brain. Twelve patients (4.5%) had serious nonvascular brain abnormalities, including cerebral metastasis in five patients and pituitary adenomas in two patients. Only nine subjects (3.3%) had a new neurologic or cognitive symptom suggestive of a brain abnormality.
Routine body imaging with FDG PET/MRI of the area from the skull base to the mid thigh may miss important brain abnormalities when the head is not included. The additional brain abnormalities identified on whole-body imaging may provide added clinical value to the management of oncology patients.
Undifferentiated mesenchymal cells were isolated from mouse embryonic lungs and plated at subconfluent and confluent densities. During the first 5 hours in culture, all the cells were negative for ...smooth muscle markers. After 24 hours in culture, the mesenchymal cells that spread synthesized smooth muscle alpha-actin, muscle myosin, desmin and SM22 in levels comparable to those of mature smooth muscle. The cells that did not spread remained negative for smooth muscle markers. SM differentiation was independent of cell-cell contact or proliferation. In additional studies, undifferentiated lung mesenchymal cells were cocultured with lung embryonic epithelial cells at high density. The epithelial cells aggregated into cysts surrounded by mesenchymal cells and a basement membrane was formed between the two cell types. In these cocultures, the mesenchymal cells in contact with the basement membrane spread and differentiated into smooth muscle. The rest of the mesenchymal cells remained round and negative for smooth muscle markers. Inhibition of laminin polymerization by an antibody to the globular regions of laminin beta1/gamma1 chains blocked basement membrane assembly, mesenchymal cell spreading and smooth muscle differentiation. These studies indicated that lung embryonic mesenchymal cells have the potential to differentiate into smooth muscle and the process is triggered by their spreading along the airway basement membrane.
PURPOSEThe aim of this study was to understand the imaging features of fluorine-18 fluorodeoxyglucose (F-FDG) PET-computed tomography (CT) in postcryoablation lung cancer patients that could help ...predict recurrence.
METHODSWe identified 28 patients with 30 lesions treated by means of percutaneous cryoablation for stage I non-small-cell lung cancer. Two experienced nuclear radiologists blindly reviewed baseline images and follow-up F-FDG PET-CT scans for a minimum of 24 months, with discrepancy in interpretation resolved by consensus. Nineteen lesions had undergone baseline PET-CT studies, whereas 11 lesions had undergone only baseline CT studies. Follow-up PET-CT studies were analyzed for up to 24 months, whereas the recurrence-free survival analysis was performed for 36 months.
RESULTSThe average maximum standardized uptake value (SUVmax) at baseline (n=19) was 5.2±3.9 and the average CT area at baseline was 2.2±1.6 cm. Only the CT area was significantly different between recurring and nonrecurring lesions at baseline (P=0.0028). The Kaplan–Meier survival analysis showed that dichotomizing lesions around 2 cm on CT did not result in a statistically significant survival difference (hazard ratio=1.42, 95% confidence interval0.63–2.21). The average SUVmax at first follow-up was 1.9±1.8 for 27 lesions, whereas the average SUVmax of recurrent lesions was 2.2±2.2 and that of nonrecurrent lesions was 1.5±0.3 (P=0.17). Six lesions had SUVmax more than or equal to 2.5 within 24 months, all of which recurred in the ablation zone.
CONCLUSIONF-FDG PET-CT is a valuable tool for determining treatment response and for distinguishing benign from malignant lesions after cryoablation. The CT area was most predictive of future recurrence at baseline, whereas SUVmax more than or equal to 2.5 was most predictive of future recurrence at first follow-up.
BACKGROUND:FDG PET-CT plays a critical role in the management of head and neck cancer patients. After therapy, many patterns of altered physiologic FDG uptake have been recognized. In our ...institution, we noticed patterns of head and neck muscle uptake that were unique in the post-therapy scans of head and neck cancer patients.
MATERIALS AND METHODS:A total of 32 patients with head and neck cancers who had both pretherapy and posttherapy FDG PET-CT scans were retrospectively analyzed. Regional anatomic muscle groups that had increased PET uptake on either pretherapy or post-therapy scans were identified.
RESULTS:On the pretherapy scans, the majority of patients (24/32 patients) did not have increased PET activity in the predefined muscle groups. On the post-therapy scans, the majority of patients (25/32 patients) demonstrated increased uptake in at least 1 head and neck muscle group, with an average of 3 muscle groups per patient. The muscle groups with the greatest frequencies were the prevertebral (50%), the accessory neck (47%), the posterior paravertebral (47%), and the scalene muscles (38%). Relative to pretherapy scans, the mean intensity of the post-therapy elevations corresponded to greater SUVs.
CONCLUSION:FDG PET-CT scan commonly depicts an elevated FDG muscle uptake in all regional anatomic muscle groups in the post-therapy head and neck cancer patient. This uptake should be considered as a consequence of treatment and perhaps changes in altered biomechanics, and not be confused with residual or recurrent neoplastic activity.
The binding of Escherichia coli LexA repressor to the recA operator was examined as a function of the concentration of NaCl, KCl, NaF, and MgCl2 at pH 7.5, 21 °C. The effects of pH at 100 mM NaCl ...were also examined. Changes both in the qualitative appearance of the binding isotherms and in the magnitude of the apparent binding affinity with changes in solution conditions suggest that binding of anions and protons by LexA repressor is linked to oligomerization and/or operator binding. Binding of LexA repressor to the recA operator in the presence of NaCl ranging from 25 to 400 mM at picomolar DNA concentration showed a broad, apparently noncooperative, binding isotherm. Binding of LexA repressor in NaF at the same DNA yielded binding isotherms with a narrow transition, reflecting an apparently cooperative binding process. Also, the apparent binding affinity was weaker in NaF than in NaCl. Furthermore, the binding affinity and also the apparent binding mode, cooperative vs noncooperative, were pH dependent. The binding affinity of LexA repressor for operator was greatest near neutral pH. The apparent binding mode was noncooperative at pH 7−9 but was cooperative at pH 6 or 9.3. These observations suggest that the specific cation and anion composition and concentrations must be considered in understanding the details of regulation of the SOS system.
For electronic equipment, especially medical imaging systems, this doubling of processing power also implies greater availability of network bandwidth, larger storage capacity, smarter computer ...algorithms, and better understanding of clinical information. The chapters on personal healthcare discuss future scenarios in which individuals take increasing responsibility for managing their own healthcare, especially through their use of electronic remote monitoring devices and day-to-day interaction via a variety of platforms such as Web browsers, cell phones, and digital medium devices.
Freshly isolated colonocytes as well as detergent-solubilized colonic mucosa and lectin purified receptor-enriched mucosal preparations were utilized to compare ligand-induced activation of ...EGF-receptor (EGF-R) tyrosine kinase (Tyr-k) activity between young (4 months) and aged (24 months) rats. In all three mucosal preparations, EGF and TGF-α produced a significantly greater stimulation in EGF-R Tyr-k activity in aged than in young rats, when compared with the corresponding basal levels. This was observed in spite of a significantly higher basal EGF-R Tyr-k activity in the colonic mucosa of aged rats than in young animals. Neither in young nor in aged rats did bombesin cause any significant change in EGF-R Tyr-k activity in the colonic mucosa. In aged rats, TGF-α also caused a stimulation in tyrosine phosphorylation of EGF-R and autophosphorylation of the 165 kDa band (a molecular mass that corresponds to EGF-R) and several other mucosal proteins (M, 120, 110, 70, 60, 55 and 50 kDa). We suggest that mitogenic activation of EGF-R Tyr-k may be an important event for the development of hyperproliferative state in the colonic mucosa of aged rats.
Undifferentiated embryonic mesenchymal cells are round/cuboidal in shape. During development, visceral myogenesis is shortly preceded by mesenchymal cell elongation. To determine the role of the ...cell's shape on smooth muscle development, undifferentiated embryonic mesenchymal cells from intestine (abundant visceral muscle), lung (some visceral muscle) or kidney (no visceral muscle) were plated under conditions that maintained cell rounding or promoted elongation. Regardless of their fate in vivo, all the cells differentiated into smooth muscle upon elongation as indicated by the expression of smooth muscle-specific proteins and the development of membrane potentials of â60 mV and voltage-dependent Ca2+ currents, characteristic of excitable cells. Smooth muscle differentiation occurred within 24 hours and was independent of cell proliferation. Regardless of their fate in vivo, all the round cells remained negative for smooth muscle markers, had membrane potentials of â30 mV and showed no voltage-activated current. These cells, however, differentiated into smooth muscle upon elongation. The role of the cell's shape in controlling smooth muscle differentiation was not overcome by treatment with retinoic acid, TGF-beta1, PDGF BB or epithelial-conditioned medium (all modulators of smooth muscle differentiation). These studies suggest that the mesenchymal cell shape plays a main role in visceral myogenesis.
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