Incorporation of a retinal rod cGMP-dependent conductance into planar bilayers.

The light-modulated current of vertebrate retinal rods flows through a 3',5'-cyclic GMP-dependent conductance located in the outer segment plasma membrane. We report the incorporation into planar bilayers of a conductance derived from vertebrate rod outer segment membranes specifically activated by cGMP but not by cAMP, 5'-GMP, GTP, or 5'-AMP. When the mean currents were measured as a function of increasing cGMP concentration, maximal activation occurred at concentrations less than 50 microM.

Nosocomial fungemia in neonates associated with intravascular pressure-monitoring devices.

In the period from January, 1982, to March, 1983, eight infants in the neonatal intensive care unit at one hospital had blood cultures positive for Candida parapsilosis; six cases had occurred after December, 1982. Epidemiologic investigation included a case-control study comparing the 8 cases with 29 birth weight-matched controls. Logistic regression analysis indicated that the model that best fit the observed data included the following risk factors for fungemia: duration of umbilical artery catheterization; duration of receipt of parenteral nutrition; and estimated gestational age.

Voltage-dependent activation in purified reconstituted sodium channels from rabbit T-tubular membranes.

We have examined the voltage-dependent gating of batrachotoxin-modified sodium channels purified from rabbit T-tubular membranes in two ways. First, purified channels were reconstituted into planar bilayers and single-channel properties were measured. Batrachotoxin-activated channels showed steep voltage-dependent activation with half-maximal opening probabilities at potentials between -95 and -116 mV.

Transmembrane calcium movement in 20,25-diazacholesterol myotonia.

An abnormality in myoplasmic Ca2+ regulation has frequently been proposed in 20,25-diazacholesterol (20,25-D) myotonia. We report here the results of several studies of transmembrane Ca2+ movement in this animal model. (i) Physiologic Ca2+ release by intact sarcoplasmic reticulum (SR) was examined in chemically skinned single muscle fibers preloaded in EGTA-buffered Ca2+ solutions (pCa2+7.

Intermittent decathexis--a type of parental dysfunction.

This paper describes a type of parental dysfunction--intermittent decathexis--which apparently has not previously been reported although it occurs frequently, to varied extent. The dysfunction is introduced by some of the clinical material that originally brought it to the author's attention, is contrasted with the more usual parental investment in their children. Its relationship to depression and then to aggression is next clarified.

An outbreak of Candida parapsilosis bloodstream infections in patients receiving parenteral nutrition.

From July to September 1981, five patients at one hospital had bloodstream infections or colonization of an intravascular cannula with Candida parapsilosis. All five cases, but none of 34 controls, were receiving parenteral nutrition at the onset of infection or colonization (P less than 0.01; Fisher's exact test, one-tailed).

Candida ciferrii and Candida chiropterorum isolated from clinical specimens.

Ten clinical yeast isolates submitted to the Centers for Disease Control from diverse geographic areas were identified as Candida ciferrii and Candida chiropterorum. The association of C. ciferrii with clinical specimens, particularly its repeated isolation from a case of onychomycosis, suggests that this species may be an etiological agent of superficial yeast infections.

20,25-diazacholesterol myotonia: an electrophysiological study.

The electrophysiological characteristics of the myotonic syndrome produced in mammalian skeletal muscle by administration of 20,25-diazacholesterol (20,25-D) were studied in detail. In vivo electromyographic recordings confirmed widespread repetitive electrical activity, but delayed relaxation was evanescent and required isotonic rather than isometric conditions, with long recovery periods between stimuli, for clear demonstration. Subsequent administration of a potent inhibitor of membrane chloride conductance (GCl) induced profound delays in relaxation different from that after chronic 20,25-D alone.

The pathophysiology of myotonia produced by aromatic carboxylic acids.

A series of nine related aromatic monocarboxylic acids (ACAs) previously shown to inhibit muscle membrane chloride conductance (GCl) selectively in the rat were studied for their ability to produce myotonia. All nine induced characteristic repetitive electrical activity and delayed relaxation in isolated muscle, although the concentrations required for this action varied widely. In each case, myotonia was observed at concentrations that correlated closely with previously determined half-maximal concentrations for inhibition of GCl.

Multiple constrast injections in epidural venography.

Multiple contrast injections were necessary in 65% of the 140 epidural venograms performed at the Penobscot Bay Medical Center between January and December 1977. Several examples of the value of multiple injections are illustrated. Institutions interested in performing epidural venography or those performing the examination on a limited basis should be aware of the need for multiple injections, allowing time for reviewing the initial series of radiographs, for reloading the film changer and injector, and for repeating fluoroscopy and catheter manipulation.

Serum bactericidal activity in the horseshoe crab, Limulus polyphemus.

Serum from the horseshoe crab, Limulus polyphemus, was examined for bactericidal activity against five species of bacteria. Greatest activity was found against Pseudomonas putida and Flavobacterium sp.; with the former, serum dilutions as high as 1:20 were capable of reducing viable counts by 50% within 2 h.