Pulse pressure responses in patients treated with Valsartan and hydrochlorothiazide combination therapy.

In a randomized, double-blind, parallel-group study of middle-aged and elderly patients, we examined the effects of treatment with the angiotensin receptor blocker valsartan (Val) in combination with hydrochlorothiazide (HCTZ) on pulse pressure (PP). After a 2-week washout period, patients entered a 4-week single-blind Val 160 mg once daily run-in period before randomization to one of three treatment groups: Val 160 mg (n = 666), Val 160 mg/HCTZ 12.5 mg (n = 670) or Val 160 mg/HCTZ 25 mg (n = 666), once daily for eight weeks. Sitting PP at baseline was similar in all groups. From baseline to randomization, Val monotherapy reduced PP by 4.7 +/- 10.2 mmHg (mean +/- SD). At the end of the study, overall reductions in PP were 6.7 mmHg for Val 160/HCTZ 12.5 and 7.5 mmHg for Val 160/HCTZ 25. Val monotherapy reduced PP in mild-to-moderate hypertensive patients. Val combined with HCTZ provides an additional dose-related reduction in PP.

Ongoing clinical trials in systemic hypertension.

Hypertension was identified as a cardiovascular risk factor in the late fifties and still remains a public health issue. The number of patients treated reaches only half of those diagnosed and, of those treated, half fail to reach target blood pressure. Furthermore, the number of antihypertensive drugs reaching the market has increased exponentially in the last few years, however, the impact on treatment and on attaining target blood pressure levels remains to be seen. The high percentage of treated patients who do not reach target blood pressure, combined with the high number of patients requiring more than one antihypertensive drug, have triggered a series of long-term morbidity and mortality trials comparing different therapeutic approaches ('new' pharmacological classes vs. 'old' pharmacological classes). These are described in this paper.

Immunologically unrelated Heliothis sp. and Spodoptera sp. midgut membrane-proteins bind Bacillus thuringiensis CryIA(b) delta-endotoxin.

The Bacillus thuringiensis toxins, CryIA(a), CryIA(b), CryIA(c) and CryIC were used in a ligand-blot assay to detect specific toxin-binding proteins in the brush-border membranes of Heliothis virescens, Helicoverpa zea, Spodoptera littoralis, Spodoptera exigua and Spodoptera litura. While CryIA(a) and CryIA(b) always recognize the same protein(s) in a given species, CryIA(c) and CryIC were found to bind to other proteins. Polyclonal antibodies directed against the CryIA(b) binding protein of H. virescens and polyclonal anti-idiotype antibodies recognizing some determinants of the CryIA(b)-binding protein involved in the interaction with the toxin, were used to analyse immunological relationships among the toxin-binding proteins. The results showed that the 170-kDa toxin-binding proteins from the H. virescens and H. zea are immunologically related. However, the toxin-binding proteins from the Spodoptera species did not cross-react with either type of antibodies. Therefore, we conclude that the CryIA(b) toxin has different binding determinants on the toxin molecules itself which can interact with specific binding sites on the toxin-binding proteins from Heliothis sp. and Spodoptera sp.

Identification and characterization of Heliothis virescens midgut membrane proteins binding Bacillus thuringiensis delta-endotoxins.

To investigate the specificity of Bacillus thuringiensis var. kurstaki strain HD1 insecticidal crystal proteins (ICP), we used membrane preparations obtained from the midgut of Heliothis virescens larvae to perform separate ligand-blot experiments with the three activated CryIA toxins. The CryIA(a) and the CryIA(b) toxins bind the same 170-kDa protein, but most likely at two different binding sites. The CryIA(c) toxin binds two proteins of molecular masses 140 kDa and 120 kDa. We also demonstrate that the binding proteins for each of the B. thuringiensis toxins are not part of a covalent complex. Although the 170-kDa protein is a glycoprotein, endoglycosidase treatment does not prevent the binding of the CryIA(a) or CryIA(b) toxin. This indicates that the sugars are not important for the binding of these toxins. A model for a protein complex binding the B. thuringiensis HD1 ICPs is presented. Our results support the idea that binding proteins on membranes of the gut epithelial cells of H. virescens larvea are important for the specificity of the bacterial toxins.

Monoclonal antibodies neutralizing mammalian DNA topoisomerase I activity.

We have isolated three different monoclonal antibodies specific for mammalian type-I DNA topoisomerase. The antibodies react with three closely adjacent epitopes located in a central section of the enzyme (between amino acid residues 344 and 483). Two of the antibodies inhibit an early step of the nicking/closing pathway. We provide evidence showing that the antibodies do not block the association of the enzyme with DNA. The antibodies are useful for immunocytochemical investigation and for further exploration of the biochemical function of mammalian type-I DNA topoisomerase.