A smart contrast agent for magnetic resonance imaging (MRI) can be used to exploit an enzymatic activity specific to the tissue or disease state signified by converting an MRI-inactivated agent to an activated MRI agent. In this study, a beta-galactopyranose-containing gadolinium(III) complex [Gd(DOTA-FPG)(H 2O)] was designed, synthesized, and characterized as being potentially suitable for a bioactivated MRI contrast agent. The (17)O NMR experiments were conducted to estimate the water exchange rate k e x 298 and rotational correlation time tau R 298 . The k ex 298 value of [Gd(DOTA-FPG)(H 2O)] is similar to that of [Gd(DO3A-bz-NO 2)(H 2O)]. The rotational correlation time value of [Gd(DOTA-FPG)(H 2O)] is dramatically longer than that of [Gd(DOTA)(H 2O)] (-) Relaxometric studies show that the percentage change in the T 1 value of [Gd(DOTA-FPG)(H 2O)] decreases dramatically in the presence of beta-galactosidase and human serum albumin. The T(1) change percentage of [Gd(DOTA-FPG)(H 2O)] (60%) is significantly higher than those of Egad and gadolinium(III)-1-(4-(2-(1-(4,7,10-triscarboxymethyl-(1,4,7,10-tetraazacyclododecyl)))-ethylcarbamoyloxymethyl)-2-nitrophenyl)-beta- d-glucopyronuronate. The signal intensity of the MR image for [Gd(DOTA-FPG)(H 2O)] in the presence of human serum albumin and beta-galactosidase (2670 +/- 210) is significantly higher than that of [Gd(DOTA-FPG)(H 2O)] in the sodium phosphate buffer solution (1490 +/- 160). In addition, the MR images show a higher-intensity enhancement in CT26/beta-gal tumor with beta-galactosidase gene expression but not for the CT26 tumor without beta-galactosidase gene expression. We conclude that [Gd(DOTA-FPG)(H 2O)] is a suitable candidate for a bioactivated MRI contrast agent in tracing gene expression.

No abstract

Pulmonary hypoplasia is a rare but usually lethal disease. We report a full-term male neonate who presented with respiratory failure immediately after birth. Chest X-ray revealed a small lung volume despite advanced ventilator support. Respiratory failure persisted and this baby died at 40.5 hours of age. The autopsy showed a lung-to-birth weight ratio of 0.69% and a radial alveoli count of 2.97. All this information confirmed the diagnosis of primary congenital pulmonary hypoplasia.

Purpose:To evaluate the potential of a new lipophilic paramagnetic complex [Gd(Bz-TTDA)] 2-[(4s)-4-benzyl-3,6,10-tri(carboxymethyl)-3,6,10-triazadodecandioic acid] 2-designed for use as a hepatobiliary MR contrast agent. Materials and Methods:MR imaging studies for normal and hepatocellular carcinoma (HCC) rat models were performed using a 1.5-T scanner. Sequential multislice T1-weighted turbo field echo (TFE) (TR/TE/flip angle: 15 msec/6.1 msec/25°) coronal images of normal rats were obtained before and after intravenous injections of 0.1 mmol/kg [Gd(Bz-TTDA)] 2-in study groups (N ϭ 12) or 0.1 mmol/kg gadopentate dimeglumine (Gd-DTPA) 2-in control groups (N ϭ 12). Similar protocols of MR imaging with additional T2-weighted images were used for the rats with implanted HCC in both study and control groups (N ϭ 12, in each group). MR images were analyzed to evaluate the time-enhancement change (% increase of signal-to-noise ratio [SI/N]) in normal liver, renal cortex, renal medulla, and tumors. The liver-lesion contrast-to-noise ratios (CNR) were also evaluated in study and control groups. The rats were killed immediately after the last MR scan to undergo autopsy and histopathologic observation. The acute toxicity test (medial lethal dose, LD50) in mice was also done. Results:The liver enhancement in normal rats reached a plateau 5-50 minutes after injection of [Gd(Bz-TTDA)] 2-, maintained for three hours, then gradually declined. Intensity of enhancement in liver, renal cortex, and medulla after injection of [Gd(Bz-TTDA)] 2-was significantly higher than with Gd-DTPA. The efficacy of tumor characterization with injection of [Gd(Bz-TTDA)]2-was similar to that of Gd-DTPA at the early dynamic phase of the contrast study. However, the liver-lesion CNRs were significantly higher in the study group in the later phase, when tumor enhancement decreased and liver enhancement persisted. The dose of LD50 in acute toxicity test of [Gd(Bz-TTDA)] 2-in mice was 7.5 mmol/kg. Conclusion:The preliminary results in this animal study indicated that [Gd(Bz-TTDA)] 2-has the potential of becoming a reliable liver MR contrast agent.

Spontaneous pneumothorax is a rare manifestation of primary lung cancer or metastasis. We report a 39-year-old man with well-differentiated squamous cell carcinoma of the tongue and cervical lymph node metastases. He developed lung metastases and spontaneous pneumothorax 22 months later after intra-arterial infusion chemotherapy. The patient was managed with partial lung resection under thoracotomy. The pneumothorax resolved completely after the operation. Histological examination demonstrated metastatic squamous cell carcinoma, which had led to a bronchopleural fistula with subsequent induction of pneumothorax. The patient recovered uneventfully and continued to receive adjuvant chemotherapy in the oncology surgery outpatient department. Unfortunately, the tumors of the tongue and cervical lymph nodes progressively enlarged despite treatment. Eventually, the patient died of respiratory failure 5 months later. In most of the previously reported cases, pulmonary metastases associated with spontaneous pneumothorax usually originate from osteogenic or soft-tissue sarcomas. Although rare, pulmonary metastasis should be considered in the etiology of spontaneous pneumothorax. Despite advanced disease, surgical treatment may be feasible.

No abstract

Mature teratomas are common neoplasms in the anterior mediastinum. However, a primary carcinoid tumor occurring in a mature teratoma is extremely rare. To our knowledge, there are only 2 published articles in the literature to date reporting a mature cystic teratoma of the mediastinum containing a carcinoid. We herein report another case of primary carcinoid tumor arising from a mature cystic teratoma in the anterior mediastinum.

To evaluate the competitive potential of a new lipophilic paramagnetic complex, Gd-Bz-TTDA [4-benzyl-3,6,10-tri (carboxymethyl)-3,6,10-triazado-decanedioic acid] compared with two other commercially available MR hepatobiliary contrast agents, gadobenate dimeglumine (Gd-BOPTA) and gadoxetic acid (Gd-EOB-DTPA), dynamic MR imaging studies were performed on normal and hepatocellular carcinoma (HCC) rat models using a 1.5-Tesla MR scanner. The results indicate that normal rats that were injected with 0.1 mmol/kg Gd-Bz-TTDA showed significantly more intense and persistent liver enhancement than those that were injected with the same dose of Gd-EOB-DTPA or Gd-BOPTA. All of these agents showed similar enhancement patterns in the implanted HCC. The liver-lesion contrast-to-noise ratios were higher and more persistent in rats that were injected with Gd-Bz-TTDA. These results indicate that Gd-Bz-TTDA is comparable with the commercially available hepatobiliary agents, Gd-EOB-DTPA and Gd-BOPTA, and can result in more intense and prolonged liver enhancement while still providing better liver-lesion discrimination. These results warrant further large-scale studies.