Evaluation of ionic equilibria in mixed-buffer isothermal titration calorimetry and continuously stirred tank reactors.

Determination of an equilibrium pH value in complex aqueous solution and deconvolution of this equilibrium to evaluate phenomena related to mixing, dilution, or progress of reaction is increasingly important in areas ranging from water quality to pharmaceutical formulations and manufacturing. Linearization of pH problems by simple algebraic substitution enables equilibria within complex buffered aqueous solutions to be modeled as an eigenvalue problem. This formulation approach makes rigorous determination of equilibrium pH values and reactor dynamics more accessible than with previous calculation methods, even when activity coefficients and non-ideality are considered.

A high-throughput pH-based colorimetric assay: application focus on alpha/beta hydrolases.

Research involving α/β hydrolases, including α-amino acid ester hydrolase and cocaine esterase, has been limited by the lack of an online high throughput screening assay. The development of a high throughput screening assay capable of detecting α/β hydrolase activity toward specific substrates and/or chemical reactions (e.g.

Angioscopic visualization of blood vessel interior in animals and humans.

The purpose of this study is to describe the use of angioscopes in flowing bloodstreams of animals and humans, to demonstrate the ability to precisely deliver laser energy to an intravascular target using visual guidance and to determine the information content and spatial content of angioscopy. Angioscopy was performed in 5 living dogs, 16 cadaver vascular segments, and 14 patients at the time of peripheral or coronary bypass surgery. Five canine femoral artery segments received angioscopically directed intravascular Nd:YAG laser irradiation.

Lack of effect of cyclandelate in peripheral arterial disease.

While cyclandelate is widely used in the therapy of peripheral arterial disease, objective evidence of its efficacy remains controversial. For this reason, 12 patients with intermittent claudication (average age of 66.8 years) received both cyclandelate 400 mg qid and placebo in a double-blind crossover trial lasting two months.

Unloading effects of molsidomine on peripheral circulation and cardiac hemodynamics in patients with acute myocardial infarction.

The unloading mechanisms and side of peripheral action of the new antianginal drug molsidomine was compared with isosorbide dinitrate (ISDN) in 14 patients with acute myocardial infarction using a Swan-Ganz catheter and venous occlusion plethysmography. Sublingual molsidomine (2-4 mg) increased calf venous capacitance (CVC) (0.42 +/- 0.

Observations on the relationship between digital heat loss and systemic hemodynamics in patients with heart disease.

A concomitant study of finger heat discharge and systemic hemodynamics was undertaken in a series of 19 patients (mean age 54 years) suffering from various forms of heart disease. Finger heat discharge, as measured by calorimetry, was found to correlate significantly with mean circulation time (-0.760), cardiac index (+0.

Peripheral hemodynamics in patients with Fabry's disease.

Altered vasomotor activity has been reported as a clinically prominent feature of Fabry's disease (angiokeratoma corporis diffusum universale). While symptomatic cardiovascular involvement occurs eventually in most patients with this disorder, little is known concerning the effect of Fabry's disease on peripheral hemodynamics. Peripheral hemodynamics in the extremities and digits were studied in eight patients with Fabry's disease by means of segmental and venous occlusion pneumoplethysmography and thermal probes, and the results obtained were compared with those of 10 normal subjects.

Unloading effects of vasodilators on peripheral circulation and cardiac hemodynamics in patients with acute myocardial infarction.

Effects of three representative vasodilators on peripheral and cardiac hemodynamics were studied in 20 patients with heart failure due to acute myocardial infarction (PCWP greater than 18 mmHg, C1 greater than 2.20 L/min/m2) using venous occlusion plethysmography and a Swan-Ganz catheter. Sublingual isosorbide dinitrate (ISDN) significantly increased calf venous capacitance (CVC) from 5 to 60 min (p less than 0.

Cardiac arrhythmias associated with treadmill claudication testing.

Eighty-one consecutive patients of an average age of 58 years with suspected lower limb arterial disease underwent standard 5-minute treadmill claudication testing. Prior to, during, and after testing the patients were monitored electrocardiographically. The number of electrocardiographic abnormalities seen in 81 patients undergoing study increased from 33 (40.

Effect of cardiac dysrhythmia on cerebral perfusion.

Extracranial carotid arterial obstructive disease has been the entity most commonly associated with transient cerebrovascular insufficiency. A nonobstructive, frequently overlooked cause of cerebral ischemia is cardiac dysrhythmia. We have explored this by observations of experimental animals and of man.