T1-weighted parenchyma attenuated inversion recovery: A novel sequence that improves contrast ratio of enhancing brain lesions

PURPOSE

The purpose of this study was to develop and test a parenchyma attenuated T1-weighted inversion recovery MR sequence (PAIR) that increases the contrast between enhancing and non-enhancing tissues in the brain and to compare the contrast ratio of enhancing brain tumors on this sequence compared to spin echo magnetization transfer (SEMT).

PATIENTS AND METHODS

PAIR sequence parameters were developed to reduce signal from gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) in a healthy adult volunteer. Forty-one patients (17 men and 24 women) with a mean age of 55±13 (SD) years (range: 21-78years) with known or suspected brain tumors underwent PAIR and SEMT imaging after intravenous administration of gadobenate dimeglumine. In patients with confirmed tumors, PAIR and SEMT images were compared for contrast ratio of tumor-to-WM, tumor-to-GM, and tumor-to-CSF.

RESULTS

A total of 23 enhancing neoplastic lesions were found in 14/41 patients. All tumors were visualized on both contrast enhanced PAIR and SEMT images. PAIR images showed a 2.5 fold increase in maximum tumor-to-GM contrast ratio (P<0.0001), a 1.4 fold increase in maximum tumor-to-WM contrast ratio (P=0.0007) and a 5-fold increase in maximum tumor-to-CSF contrast ratio (P<0.0001).

CONCLUSION

PAIR provides improved lesion-to-background contrast ratio compared to SEMT and may be useful as an added sequence in tumor evaluation.

Clinical and demographic characteristics predictive of treatment outcomes for certolizumab pegol in moderate to severe Crohn's disease: analyses from the 7-year PRECiSE 3 study

BACKGROUND

Clinical factors were previously identified as predictors of short-term treatment efficacy in Crohn's disease (CD). The PRECiSE 3 (P3) 7-year trial provides an opportunity to study predictors of short- and long-term clinical remission among CD patients treated with certolizumab pegol (CZP).

AIM

To identify factors that influence long-term remission of CD with CZP treatment.

METHODS

Patients who had completed placebo-controlled studies (PRECiSE 1/PRECiSE 2, P1/P2) enrolled in P3 and received open-label CZP 400 mg every 4 weeks up to 7 years. Baseline predictors included, but were not limited to, smoking status, disease duration, prior inflammatory bowel disease (IBD) surgery, Harvey-Bradshaw Index (HBI), albumin, haematocrit and CZP exposure; association with time to initial remission (HBI ≤4) was tested for patients who received CZP in P1/P2; time to loss of remission/frequency of maintenance of remission was also tested. Univariate analyses and multivariate Cox or logistic regression models were used.

RESULTS

Predictors for initial remission (N = 377) included age, haematocrit, prior IBD surgery and entry HBI (P < 0.05 for all). Predictors for loss of remission (N = 437) included HBI, serum albumin concentration, haematocrit, smoking status and exposure. Predictors of maintenance of remission (N = 437) included haematocrit, IBD surgery, HBI, disease duration, serum albumin concentration and exposure. Significant predictors were confirmed with stepwise multivariate regression models.

CONCLUSIONS

These analyses identified several influential parameters for short-and long-term remission of Crohn's disease with certolizumab pegol treatment. The data yield valuable hypotheses regarding factors that influence certolizumab pegol treatment. More investigation is needed. (ClinicalTrials.gov identifier NCT00552058).

Computed tomography-directed fine needle aspiration of skull base parapharyngeal and infratemporal fossa masses

Suspicious findings in the parapharyngeal region on computed tomographic (CT) or magnetic resonance imaging studies can be a diagnostic problem. Blind biopsy through the mucosa can be inadequate, since the abnormality is not directly visible. With CT guidance, fine needle aspiration (FNA) of parapharyngeal masses can be performed with a needle confidently placed within the lesion. Vital structures such as the carotid artery are avoided. We present a series of 33 CT-guided FNA on 30 patients to evaluate the safety and the degree of accuracy of the procedure. Most of the patients had been treated previously for local malignancy. All patients had surgical pathologic study, autopsy, or clinical and imaging follow-up to confirm the FNA cytology results. Twenty of the 33 biopsies were positive for malignant cells, confirming recurrence of the primary head and neck malignancy. Of the 33 CT-directed FNA, 13 were negative for malignant cells. Three of these 13 were found to be false-negative FNA. None of the patients had complications from the procedure. CT directed FNA of masses at the skull base or in the parapharyngeal area can be performed safely. A high degree of accuracy is achieved, with 30 (90.9%) accurate in identifying the presence or absence of malignancy in our series.

Enhanced Production of Monomeric Interferon-β by CHO Cells through the Control of Culture Conditions

The enhancement of recombinant protein expression of a transfected cell line is essential for the development of an efficient large-scale bioprocess. The effect of various media additives and temperature conditions were studied in an attempt to optimize protein production, stability, and protein glycosylation from a Chinese hamster ovary (CHO) cell line producing human beta-interferon (Hu-beta-IFN). We observed a decrease in the ELISA response of the glycoprotein in the later stages of batch cultures, which was attributed to molecular aggregation. Cells were subjected to various concentrations of glycerol, dimethyl sulfoxide (DMSO), and sodium butyrate (NaBu) in a variety of culture systems and conditions. The addition of both NaBu and DMSO resulted in higher specific productivities but reduced growth rates that resulted in a net reduction of interferon produced. Glycerol appeared to stabilize the secreted beta-IFN, resulting in reduced aggregation, despite a decrease in cell growth rate. Glycosylation analysis of isolated beta-IFN showed a time-dependent decrease in sialylation in batch culture that was ameliorated by the presence of glycerol. Low-temperature conditions (30 degrees C) had the greatest effect on productivity with a significant increase in beta-IFN titer as well as a reduction in the degree of molecular aggregation.

Antisense oligodeoxyribonucleotide inhibition of TGF-beta 1 gene expression and alterations in the growth and malignant properties of mouse fibrosarcoma cells

Transforming growth factor (TGF-beta) is a family of multifunctional signalling molecules that play a fundamental role in both normal and malignant cell behavior. Procedures that alter mouse TGF-beta 1 gene expression provide an important approach for analyzing the complex regulatory processes associated with this member of the growth factor family. Therefore, we have designed oligodeoxyribonucleotides (oligos) in an antisense orientation, which are complementary to regions of the TGF-beta 1 message, in an attempt to obtain an oligo sequence that specifically reduces TGF-beta 1 synthesis. We observed that oligos containing a mixture of phosphorothioate and phosphodiester linkages were less toxic and more specific when compared to those only containing phosphorothioate. A non-toxic sequence was identified that markedly reduced the levels of TGF-beta 1 in oligo-treated malignant mouse fibrosarcoma cells. The invasive and metastatic properties of these fibrosarcoma cells were also significantly decreased following treatment with the antisense oligo. The results indicate an important role for altered TGF-beta 1 expression in the regulation of malignant cell proliferation, invasion and metastasis. These results also indicate that this oligo sequence is a useful tool for studies directed towards understanding the complex relationships between TGF-beta 1 and cellular regulation.

Growth factor modulation of metastatic lung colonization

Altered production and response to growth factors is often involved in neoplasia but little is known about their effect on the dissemination of tumors. Therefore, we have examined the effect of growth factors on metastatic lung colonization. Autocrine induction of the metastatic phenotype was demonstrated in NIH-3T3 cells transformed by a signal peptide-bFGF gene but not bFGF in the absence of the signal peptide. In addition, exogenous growth factor regulation of metastasis was demonstrated. Treatment of ras transformed C3H-10T 1/2 cells and ras or src transformed NIH-3T3 cells with bFGF prior to intravenous injection resulted in potent inhibition of metastatic potential. Stimulation of v-fms transformed cells by the natural fms-ligand, CSF-1, resulted in potent stimulation of metastatic behavior in freshly plated or refed cells, whereas following autocrine conditioning of the medium, the metastatic properties of these cells were sensitive to inhibitory effects of CSF-1. These observations indicate that specific growth factors can regulate the metastatic phenotype and, depending on the oncogenes responsible for cell transformation and autocrine conditioning, these effects can be either stimulatory or inhibitory.