Spontaneously and pharmacologically provoked coronary arterial spasm in Prinzmetal variant angina

Eleven of 21 consecutive patients with Prinzmetal angina (PMA) exhibited no significant fixed stenoses of the coronary arteries. Spontaneous coronary arterial spasm was demonstrated in 3 patients. Ergonovine maleate produced near-total occlusion of a major vessel in 3 of 4 other patients with PMA, but did not provoke spasm in 10 without PMA. The current study documents spasm as the mechanism of myocardial ischemia in some patients with normal coronary arteries and provides initial and favorable diagnostic results with provocative pharmacoangiography in this entity.     

High-throughput plasmid mini preparations facilitated by micro-mixing

We have developed a reliable high-throughput plasmid isolation system using a 96-well plate format. This system combines a novel glass bead micro-mixing method with modified alkaline lysis and Sephacryl S-500 DNA purification procedures. Mechanical forces generated by vortexing glass beads inside each well of the 96-well plates ensure that the bacterial pellets are homogeneously resuspended, the cells are completely lyzed, and the resulting bacterial lysates are thoroughly mixed with the potassium acetate solution. The vortexing speed and duration for glass bead mixing have been standardized to facilitate plasmid DNA yields without significant adjustments.     

Therapy for the maintenance of remission in sixty-five patients with generalized Wegener's granulomatosis. Methotrexate versus trimethoprim/sulfamethoxazole

OBJECTIVE: To compare the efficacy of low-dose intravenous (IV) methotrexate (MTX; 0.3 mg/kg once weekly), both with and without concomitant prednisone, versus daily oral trimethoprim/sulfamethoxazole (T/S; 160 mg of trimethoprim + 800 mg of sulfamethoxazole twice a day), with and without prednisone, in maintaining remission in patients with generalized Wegener's granulomatosis (WG). METHODS: In this study, 65 patients with generalized WG whose disease had entered remission with cyclophosphamide (CYC) and prednisone therapy were started on one of the following remission-maintenance regimens: MTX alone (group A; n = 22), T/S alone (group B; n = 24), MTX plus concomitant prednisone (group C; n = 11), and T/S plus concomitant prednisone (group D; n = 8). Clinical, radiographic, and seroimmunologic data were evaluated to assess the efficacy of the 4 regimens and to seek possible predictive factors concerning outcome in each group. RESULTS: Partial or complete remission was maintained in 86% of the patients in group A, but in only 58% of those in group B (P < 0.05). In group C, 91% of patients remained in remission, which is in sharp contrast to group D, in which all patients experienced a relapse after a median of 14.5 months (P < 0.005). Side effects occurred twice as often with MTX (n = 12) as with T/S (n = 6) treatment and could usually be resolved by supplemental folinic acid. Two patients taking MTX and 3 patients taking T/S were withdrawn from the study medication because of side effects. In none of the patients were the adverse effects life threatening. No statistically significant factors predictive of poor outcome emerged in any group. CONCLUSION: Low-dose MTX was found to be superior to T/S for the safe and effective maintenance of remission in patients with generalized WG. The use of concomitant prednisone was not associated with a worse outcome with MTX treatment. Since T/S, especially with concomitant prednisone, seemed to increase the chance of relapse, neither T/S alone nor T/S plus prednisone can be recommended for the maintenance of remission in patients with generalized WG.     

Use of multiple surveys to estimate mortality among never, current, and former smokers: changes over a 20-year interval

OBJECTIVES: This study sought to demonstrate how data from publicly available large-scale cross-sectional health surveys can be combined to analyze changes in mortality risks among never, current, and former smokers. METHODS: Data from the 1966/68 and 1986 National Mortality Followback Surveys and the 1970 and 1987 National Health Interview Surveys were used to estimate the distribution of never, current, and former smokers among the US population at risk and decedents. Standardized mortality ratios and quotients of standardized mortality ratios were used to estimate mortality risks. RESULTS: Generally, during the period from 1966 through 1986, mortality rates in the United States for most causes of death declined among all smoking groups. However, mortality rates from respiratory diseases increased for current and former smokers. CONCLUSIONS: The reported changes in never and current smoker mortality risks are similar in magnitude and direction to those reported in a previous study based on longitudinal data. The use of combined data from the National Mortality Followback Survey and the National Health Interview Survey offers several advantages as an epidemiological tool.     

Tyrosine kinase inhibitors. 14. Structure-activity relationships for methylamino-substituted derivatives of 4-[(3-bromophenyl)amino]-6-(methylamino)-pyrido[3,4-d]pyrimidine (PD 158780), a potent and specific inhibitor of the tyrosine kinase activity of receptors for the EGF family of growth factors

The 4-[(3-bromophenyl)amino]pyrido[3,4-d]pyrimidine PD 158780 is a very potent in vitro inhibitor of the tyrosine kinase activity of the epidermal growth factor receptor (EGFR) (IC50 0.08 nM), and other members of the erbB family, by competitive binding at the ATP site of these signal transduction enzymes. A series of analogues of PD 158780 bearing solubilizing functions off the 6-methylamino substituent were prepared by reaction of the 6-fluoro derivatives with appropriate amine nucleophiles. These were evaluated for their ability to inhibit the tyrosine phosphorylating action of EGF-stimulated full-length EGFR enzyme and for inhibition of autophosphorylation of the EGFR in A431 human epidermoid carcinoma cells in culture. The most effective analogues were those bearing weakly basic substituents through a secondary amine linkage, which proved water-soluble (> 10 mM) and potent (IC50S generally < 1 nM). No clear SAR could be discerned for these compounds with respect to amine base strength or the distance of the cationic center from the chromophore, suggesting that 6-substituents are in a favorable area of bulk tolerance in the enzyme binding site. More distinct SAR emerged for the ability of the compounds to inhibit EGFR autophosphorylation in A431 cells, where analogues bearing lipophilic weak bases were preferred. Representative analogues were evaluated for antitumor effectiveness against four in vivo tumor models. Significant in vivo activity was observed in estrogen-dependent MCF-7 breast and A431 epidermoid tumors. Marginal activity was seen in an EGFR-transfected tumor model, suggesting that while this cell line requires EGF for clone formation in soft agar, other growth factors may be able to replace EGF in vivo. Also, no activity was seen against the SK-OV-3 ovarian cancer model, which is known to express other EGF receptor family members (although it is not clear whether these are absolutely required for growth in vivo). While substantial growth delays were seen in A431 and MCF-7 tumor models, the treated tumors remained approximately the same size throughout therapy, suggesting that the compounds are cytostatic rather than cytotoxic under these test conditions. It remains to be determined if more prolonged therapy has cytotoxic effects in vivo, resulting in net tumor cell kill.