The β-subunits of voltage-gated Ca(2+) (Ca(V)) channels regulate the functional expression and several biophysical properties of high-voltage-activated Ca(V) channels. We find that Ca(V) β-subunits also determine channel regulation by the membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP(2)). When Ca(V)1.3, -2.1, or -2.2 channels are cotransfected with the β3-subunit, a cytosolic...

Kv7 K(+)-channel subunits differ in their apparent affinity for PIP(2) and are differentially expressed in nerve, muscle, and epithelia in accord with their physiological roles in those tissues. To investigate how PIP(2) affinity affects the response to physiological stimuli such as receptor stimulation, we exposed homomeric and heteromeric Kv7.2, 7.3, and 7.4 channels to a range of concentrati...

In an earlier study (Miwa, M., Hill, C., Kumar, R., Sugatani, J., Olson, M. S., and Hanahan, D. J. (1987) J. Biol. Chem. 262, 527-530) it was shown that an inhibitor of platelet-activating factor (PAF), a powerful endogenous mediator of platelet aggregation, was present in freeze-clamped perfused livers. Subsequently, we determined that this substance was a mixture of unsaturated free fatty aci...

This opinion article has been written on request because of the recent public controversy over silicone breast implants produced by a now-defunct company, Poly Implant Prosthese (PIP) in France. More than 300,000 PIP devices have been implanted. The purposes of my article are to (1.) provide a general overview of silicone breast implant materials, (2.) to describe the general safety of these ma...

BACKGROUND Fractures and dislocations of the proximal interphalangeal (PIP) joint of the fingers are among the most common causes of injury in the hand. Objective assessment of the kinematic alterations occurring when the supporting structures are disrupted is critical to obtain a more accurate indication of joint stability. METHODS An in vitro cadaver model of the hand was used to evaluate t...

The specific role of solid extracellular matrix components in opposing development of pulmonary interstitial edema was studied in adult anesthetized rabbits by challenging the lung parenchyma with an intravenous injection of a bolus of collagenase or heparanase. In 10 rabbits, pulmonary interstitial pressure (Pip) was measured by micropuncture in control and up to 3 h after collagenase or hepar...

Inhibition of cytochrome P450 (P450) enzymes (CYP) has been shown to lower the metabolism of drugs that are P450 substrates and to consequently alter their pharmacokinetic profiles. Curcumin (CUR), piperine (PIP), and capsaicin (CAP) are spice components (SC) that inhibit the activities of a range of P450 enzymes, but the selection of which SC to be prioritized for further development as an adj...

BACKGROUND Dupuytren disease (DD) is a fibroproliferative disorder of the palmar fasciae causing extension deficit and impaired hand function. Treatment with injection of collagenase clostridium histolyticum (CCH) is a nonsurgical treatment method. The aim of this study was to evaluate the difference in efficiency and recurrence at 12-month follow-up when treating metacarpophalangeal (MP) and p...

BACKGROUND Previous studies have indicated that complement may be activated or inherently abnormal in systemic sclerosis (SSc), and it has been suggested that immune complex deposition plays a part in the microvascular damage of this disease. OBJECTIVE To study several aspects of the complement system in 24 patients with SSc. METHODS Complement dependent prevention of immune precipitation (...

Polyphosphoinositides are among the most highly charged molecules in the cell membrane, and the most common polyphosphoinositide, phosphatidylinositol-4,5-bisphosphate (PIP(2)), is involved in many mechanical and biochemical processes in the cell membrane. Divalent cations such as calcium can cause clustering of the polyanionic PIP(2), but the origin and strength of the effective attractions le...