A method for assessing accurate application of the Partin Tables in the pre-therapy evaluation of patients with prostate cancer.

AIMS: The treatment of prostate cancer is frequently influenced by the Partin Tables. This predictive model has been internally and externally validated since it was conceived, and has proved to be remarkably reliable and consistent. This paper proposes that, by using the statistical programme for the social sciences (SPSS) and receiver-operator characteristic curves, it is possible to detect institutions that apply this model sub-optimally. MATERIALS AND METHODS: This theory was supported by a PUBMED search using relevant search words. RESULTS: This is a novel technique with the potential to allow retrospective and prospective accrual of results. CONCLUSIONS: A systematic institutional review of how accurately a hospital assesses the clinical stage, Gleason score and PSA has the potential to increase an institution's predictive accuracy when it uses the Partin Tables. The proposed method allows for quantitation of the level of error and comparison of predictive accuracy between institutions. It also may be used as an internal outcome measure to assess improvement in a hospital's investigative procedures over time.

4,4-Disubstituted piperidine high-affinity NK1 antagonists: structure-activity relationships and in vivo activity.

Previously reported studies from these laboratories described the design of a novel series of high-affinity NK1 antagonists based on the 4,4-disubstituted piperidine ring system. Further structure-activity studies have now established that for high NK1 affinity the benzyl ether side chain must be 3,5-disubstituted and highly lipophilic, the optimal side chain being the 3, 5-bis(trifluoromethyl)benzyl ether, 12 (hNK1 IC50 = 0.95 nM). Additional studies have shown that this class of NK1 antagonist tolerates a wider range of substituents on the piperidine nitrogen, including acyl (38) (hNK1 IC50 = 5.3 nM) and sulfonyl (39) (hNK1 IC50 = 5.7 nM) derivatives. Following preliminary pharmacokinetic analysis, two compounds (32 and 43) were selected for in vivo study in the resiniferotoxin-induced vascular leakage model, both showing excellent profiles (ID50 = 0.22 and 0.28 mg/kg, respectively).

Serine derived NK1 antagonists. 1: The effect of modifications to the serine substituents.

A series of novel serine derived NK1 antagonists is described. The effect of variations in the N-benzyl, O-benzyl and serine groups are used to define the elements which are necessary for binding.

Tryptophan-derived NK1 antagonists: conformationally constrained heterocyclic bioisosteres of the ester linkage.

The 3,5-bis(trifluoromethyl)benzyl ester of N-acetyl-L-tryptophan 1 (L-732,138) has been identified previously as a potent and selective substance P receptor antagonist. A series of analogs which introduced a 6-membered heterocyclic ring into the backbone of this structure were prepared for evaluation as bioisosteric replacements of the ester linkage of 1. The 2,5-dioxopiperazine 2 had very weak receptor affinity, but 2-oxopiperazine 5 exhibited modest activity. Examination of the conformations accessible to the substituents on these templates led to exploration of the corresponding 5-membered heterocyclic rings. This study culminated in the identification of oxazolidinedione 14 as a suitable ester mimic in terms of the retention of good NK1 binding affinity.

Identification of L-tryptophan derivatives with potent and selective antagonist activity at the NK1 receptor.

As part of a program of screening the Merck sample collection, N-ethyl-L-tryptophan benzyl ester was identified as a weak antagonist at the substance P (NK1) receptor. Structure-activity studies showed that the indole ring system could be replaced by 3,4-dichlorophenyl, alpha- or beta-naphthyl, or benzthiophene with retention or only small loss of affinity. It was found that acylation of the tryptophan nitrogen gave compounds with higher affinity than N-ethyl or other basic amines. Optimization of substitution on the benzyl ester led to the identification of the 3,5-bis-(trifluoromethyl)benzyl ester of N-acetyl-L-tryptophan 26 as a potent and selective substance P receptor antagonist. Compound 26 blocked substance P induced dermal extravasation in vivo and was the most potent compound from this structurally novel class of antagonists which further adds to the diversity of small molecules that bind to the (NK1) receptor.

The formation of a dimeric product of raffinose by the action of galactose oxidase.

1. Galactose oxidase is known to catalyze the oxidation of the C-6 hydroxymethyl group of galactose to an aldehyde group. 2. When the products of a galactose oxidase-catalase treatment of raffinose were examined by gel filtration and ion exchange chromatography, we found that in addition to the expected 6"-aldehydroaffinose, two other components were present. 3. One component was neutral and had an elution volume close to that of maltopentaose and on treatment with sodium borohydride or hypoiodite, this component was converted to raffinose or 6"-carboxyraffinose, respectively. 4. Fast atom bombardment mass spectroscopy in the negative mode indicated that the major molecular ion had an M/Z of 1003. 5. These data are consistent with this component being a dimer of 6"-aldehydoraffinose.

Purification of galactose oxidase from Dactylium dendroides by affinity chromatography on melibiose-polyacrylamide.

Galactose oxidase is a fungal enzyme which is known to oxidize the C-6 hydroxymethyl of galactose and galactosamine to an aldehyde group. It has been widely used in glycoconjugate research, for example in the labeling of asialoglycoproteins. We have developed a simple affinity purification for galactose oxidase using melibiose-polyacrylamide. This affinity procedure was used to purify the enzyme from ammonium sulfate precipitates of culture filtrates of Dactylium dendroides. The material containing proteases and other contaminants is eluted in the buffer wash. The galactose oxidase is then specifically eluted from the column with buffer containing 0.1 M D-fucose or D-galactose. Using this procedure, the enzyme was also purified from commercial samples of galactose oxidase which contain high proteolytic activity.

Preparation and characterization of beta-D-fructofuranosyl O-(alpha-D-galactopyranosyl uronic acid)-(1----6)-O-alpha-D-glucopyranoside and O-(alpha-D-galactopyranosyl uronic acid)-(1----6)-D-glucose.

beta-D-Fructofuranosyl O-(alpha-D-galactopyranosyl uronic acid)-(1----6)-O-alpha-D-glucopyranoside (3) was prepared by treating raffinose with D-galactose oxidase, followed by hypoiodite oxidation of the resulting aldehyde. Mild acid hydrolysis of 3 gave O-(alpha-D-galactopyranosyl uronic acid)-(1----6)-D-glucose.

Re-examination of the products of the action of galactose oxidase. Evidence for the conversion of raffinose to 6''-carboxyraffinose.

Galactose oxidase is a fungal enzyme which is known to oxidize the C-6 hydroxymethyl of galactose to an aldehyde group. When the products of a galactose oxidase-catalase treatment of raffinose were examined by gel filtration and ion exchange chromatography, we found that, in addition to the expected 6''-aldehydoraffinose, two other components were present. Of these two components, the major one was retained on a column of AG 1-X8 (formate), gave a positive carbazole reaction for uronic acid, and on paper chromatograms had a mobility identical with that of 6''-carboxyraffinose. The infrared spectrum of the compound showed a carbonyl absorbance at 1725 cm-1 and was distinguishable from the spectra of raffinose and 6''-aldehydoraffinose. These data showed that raffinose was partly converted to 6''-carboxyraffinose when treated with galactose oxidase and catalase. The conversion of [3H]raffinose to [3H]6''-carboxyraffinose increased gradually with time of oxidation from 22% at 6 h to 68% at 96 h. Results of other experiments provided evidence that this was an enzymic conversion and depended on the presence of galactose oxidase. The activities responsible for the formation of aldehyde and uronic acid could not be separated by affinity chromatography, gel electrophoresis, or ion exchange chromatography, indicating that the same enzyme is responsible for both activities. Treatment of galactose, melibiose, and stachyose with galactose oxidase and catalase also resulted in the formation of the corresponding uronic acids. These studies indicate that galactose oxidase not only converts the C-6 hydroxymethyl group of galactose to an aldehyde group, but also catalyzes further oxidation to the carboxyl group.

Dispersion of protein solutions in short, open capillary tubes as a method for rapid molecular weight determination.

A method has been developed by which the molecular weight of proteins and other freely diffusing species can be estimated on the basis of chromatographic peak shapes developed by injection of a sample into an open capillary tube in a liquid chromatography system. In chromatographic peaks obtained from such a system, there are contributions from both convection and diffusion. Thus, peak shape is dependent upon the diffusion coefficient of the molecular species, the flow rate, and the length of the capillary tube. In the work reported here it has been found that for samples of different proteins ranging from 2000 to 14,000 molecular weight, each injected at the same mobile phase flow rate, the ratio (R) of h1, the height of the peak primarily due to convection, to h2, the height of the "makeup" peak, primarily due to diffusion from the capillary wall, is a direct measure of protein molecular weight. Linear plots of R vs molecular weight are obtained under certain conditions.