Biomedical subjects

J Hua

Publications and source records attributed to J Hua.

111 records · Page 7Linked to original sources

PubMedDate not supplied

Combretastatin A-1 phosphate potentiates the antitumor activity of carboplatin and paclitaxel in a severe combined immunodeficiency disease (SCID) mouse model of human ovarian carcinoma.

In search for new therapeutic modalities to target epithelial ovarian carcinomas, we investigated the effect of the antiangiogenic drug combretastatin A-1 phosphate (CA1P) as a single treatment or in combination with established therapy, ie, carboplatin and paclitaxel. Five different human epithelial ovarian carcinoma cell lines were inoculated subcutaneously into FOX CHASE CB-77 severe combined immunodeficiency disease (SCID) mice. When tumors reached a volume of approximately 100 mm(3), the treatment was initiated. All drugs were given intraperitoneally at weekly doses. CA1P was more effective as an antitumor agent than combretastatin A-4 phosphate as a single-drug treatment or in combination with carboplatin and paclitaxel. CA1P had a strong tumor outgrowth inhibiting effect on four out of five tumors included in this study. Comparing animals receiving CA1P with animals receiving a combination of carboplatin and paclitaxel, CA1P was more effective on two out of three tested tumors, whereas carboplatin and paclitaxel were more effective on one out of three of the tumors. We show that treatment of human ovarian carcinomas with CA1P in the SCID mouse model results in a strong antitumor effect both as a single-drug treatment and as an enhancement of the therapeutic effect in a combination treatment protocol with carboplatin and paclitaxel.

Animals↗

PubMedDate not supplied

Some noise properties of 2DFT MR images from asymmetrically sampled data.

This report describes noise statistics in 2DFT MR images, expanding the earlier work of Henkelman and others to include variably asymmetric sampling and conjugate synthesis reconstruction. The effects of low-order polynomial and Fourier phase correction used with conjugate synthesis are also explicitly considered. This analysis shows that complex images obtained by conjugate synthesis have an elliptical noise distribution, with the smaller axis corresponding to the imaginary image channel. Derivations and simulations predict a ratio of mean to standard deviation in the background of magnitude images varying from the known value of square root of pi/(4 - pi) (approximately 1.91) for full symmetry to square root of 2/(pi - 2) (approximately 1.32) at fully asymmetric or half-echo sampling; these predictions are validated over a range of asymmetry by experimental measurements. These results are important for predicting and interpreting image noise when using asymmetric sampling.

Fourier Analysis↗

PubMedDate not supplied

Comparison of antitumor activity of declopramide (3-chloroprocainamide) and N-acetyl-declopramide.

Previous studies have suggested that some of the antitumor activity of declopramide (3-chloroprocainamide) could be due to its metabolites. One metabolite has been identified as N-acetyl-declopramide (N-acetyl-3-chloroprocainamide). The aim of this study is to investigate the bioactivity of N-acetyl-declopramide and to compare it with its parent compound. The data have shown that N-acetyl-declopramide inhibited tumor cell growth in vitro in HL60 and K562 cells, and in vivo in scid mice xenografted with a human brain astrocytoma (T24), which was evaluated after oral doses of 20 and 40 mg/kg given at 0, 24 and 48 hr +/- a single im dose of cisplatin (7.5 mg/kg). The action was presumably by inducing DNA strand breaks and apoptosis. No acute toxic symptoms and no body weight loss were observed. N-acetyl-declopramide given orally or im gave a similar drug level in mouse serum 30 minutes after administration (p > 0.05). It had a greater antitumor activity in vitro in HL60 or K562 cells and a similar efficacy of inhibiting tumor growth in vivo, when compared with declopramide. These data provided an explanation for the primary result obtained in this study, i.e. declopramide administered orally at 40 mg/kg gave the same efficacy of inhibiting tumor growth as im injection although oral administration had a lower bioavailability due to the formulation of N-acetyl-declopramide. Based on these data, it was concluded that the antitumor properties of declopramide administered orally were not compromised by metabolism to N-acetyl-declopramide because the latter also has strong antitumor properties.

Acetylation↗