Narrative Review of Use and Continued Relevance of the Maternal Infant Responsiveness Instrument.

BACKGROUND: The Maternal Infant Responsiveness Instrument (MIRI) was developed in 2002 to measure a critical aspect of maternal-infant health. The objective of this analysis was to examine use, results, and continued relevance of the MIRI 20 years after its creation. METHODS: For the completion of this narrative review, 5 electronic databases were accessed using key search terms. Inclusion criteria were English-language, peer-reviewed research using the MIRI. Hand searches of reference lists were conducted. Five authors performed screening, data extraction, appraisal, and summarized findings. RESULTS: Fifteen studies were included. All studies reported an internal consistency of α > 0.70 for the MIRI. Positive correlations were reported with self-efficacy, infant temperament, and life satisfaction. Inverse relationships were reported with stress, depression, and experiential avoidance. Depressive symptomatology, life satisfaction, self-esteem, self-efficacy, and previous childcare experience were predictors of maternal responsiveness. DISCUSSION: Maternal well-being (postpartum depression and stress) can affect maternal responsiveness. Given the pervasive disparities in maternal health and well-being, it is important to have reliable measures of the effects of those disparities. The MIRI, a valid and reliable measure, may be useful for assessing the effectiveness of interventions designed to improve infant and maternal well-being.

Assembly of an A kinase-anchoring protein-beta(2)-adrenergic receptor complex facilitates receptor phosphorylation and signaling.

Phosphorylation of G-protein-coupled receptors by second-messenger-stimulated kinases is central to the process of receptor desensitization [1-3]. Phosphorylation of the beta(2)-adrenergic receptor (beta(2)-AR) by protein kinase A (PKA), in addition to uncoupling adenylate cyclase activation, is obligatory for receptor-mediated activation of mitogen-activated protein kinase (MAP kinase) cascades [4] [5]. Although mechanisms for linking G-protein-coupled receptor kinases to the activated receptor are well established, analogous mechanisms for targeting second messenger kinases to the beta(2)-AR at the plasma membrane have not been elucidated. Here we show that the A-kinase-anchoring protein, AKAP79/150, co-precipitates with the beta(2)-AR in cell and tissue extracts, nucleating a signaling complex that includes PKA, protein kinase C (PKC) and protein phosphatase PP2B. The anchoring protein directly and constitutively interacts with the beta(2)-AR and promotes receptor phosphorylation following agonist stimulation. Functional studies show that PKA anchoring is required to enhance beta(2)-AR phosphorylation and to facilitate downstream activation of the MAP kinase pathway. This defines a role for AKAP79/150 in the recruitment of second-messenger-regulated signaling enzymes to a G-protein-coupled receptor.

A practical method of image enhancement by interactive digital filtering.

A generalized form of the Wiener digital filter is described in which the user interactively varies two filter parameters to produce any desired number of filtered versions of a given image with differing blends of sharpening and smoothing qualities. Filtering is performed sufficiently rapidly, even without use of an array processor, to make application of the filter truly interactive. Use of the filter is illustrated with typical nuclear medicine images.

Cerebral cortex does not modulate "regulated" decrease in core temperature during hypoxemia in rats.

In newborns and adults of a number of species including humans, exposure to acute hypoxemia produces a "regulated" decrease in core temperature, the mechanism of which is unknown. Considering that various cortical areas participate in autonomic regulation including thermoregulation, the present experiments were carried out to test the hypothesis that the cerebral cortex plays a role in modulating the regulated decrease in core temperature during acute hypoxemia. This hypothesis was tested by determining the core temperature response to acute hypoxemia in chronically instrumented adult Sprague-Dawley rats before and after cortical spreading depression (i.e., functional decortication) was produced by the local application of potassium chloride to the dura overlying the cerebral hemispheres. There was no effect of cortical spreading depression on baseline core temperature. Core temperature decreased during acute hypoxemia in a similar fashion when the cerebral cortex was intact as well as during functional decortication. Thus our data do not support the hypothesis that the cerebral cortex modulates the regulated decrease in core temperature that occurs in adult rats during acute hypoxemia.

The platelet-activating factor acetylhydrolase from human erythrocytes. Purification and properties.

Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3- phosphocholine) is a biologically active phospholipid. Tissues, blood cells, and plasma contain PAF acetylhydrolases (calcium independent phospholipase A2 activities) that catalyze the hydrolysis of phospholipids containing short chain sn-2 acyl groups. They inactivate PAF and thereby determine PAF accumulation. We purified the PAF acetylhydrolase from human erythrocytes 15,600-fold. The enzyme has a molecular weight of 25,000, it behaves as a dimer during gel filtration, and it is a previously uncharacterized cytosolic esterase, as it has a unique amino-terminal sequence. The erythrocyte PAF acetylhydrolase requires the addition of sulfhydryl agents for maximal activity, is inhibited by 5,5'-dithiobis(2-nitrobenzoic acid), NaF, diisopropyl fluorophosphate, diethylpyrocarbonate, p-bromophenacylbromide, and a number of proteases. Antibodies against the purified protein precipitate all PAF hydrolase activity from erythrocyte lysates. The erythrocyte PAF acetylhydrolase is specific for short or oxidized sn-2 acyl residues. It exhibits surface dilution kinetics, suggesting that hydrolysis occurs at lipid interfaces. This suggests that this enzyme acts in vivo as a scavenger of oxidatively fragmented phospholipids that are toxic to the cell.

Dealing with death and dying.

We instituted two thanatology seminars for medical students and residents which emphasized feelings more than objective data. The seminars began with students filling out a death certificate on themselves. Eighty-four per cent predicted that their own probable cause of death would be from an acute illness. Discussion and reflection on this experience helped them realize how difficult it would be to deal with a chronic illness. By answering a question about what they were most grateful for, they became aware that they valued family and friends most highly. We believe that this experience legitimized feelings which form the basis of empathy.

Angiography is useful in detecting the source of chronic gastrointestinal bleeding of obscure origin.

The treatment of patients with chronic gastrointestinal bleeding can be a frustrating diagnostic challenge. In the past 10-15 years, a variety of new diagnostic procedures (e.g., fiber-optic endoscopy, scintigraphy, and double-contrast barium studies) have become available to examine these patients. Despite these new procedures, a small number of patients continue to bleed without a defined cause. We sought to evaluate the role of visceral angiography in patients with chronic gastrointestinal bleeding in whom findings on an extensive noninvasive workup have been normal. Between 1983 and 1990, we obtained angiograms on 36 such patients. The cause of bleeding was established by angiography in 16 patients (44%). In 11 of these 16, angiography revealed only a structural abnormality without active bleeding. Twenty patients had normal angiographic findings. No angiograms were false-positive, but three were false-negative (8%). No complication occurred as a result of the angiographic procedures. Our experience shows that visceral angiography can provide a positive diagnosis in a significant number of patients with chronic gastrointestinal bleeding of obscure origin in whom all other diagnostic measures have been unrevealing. Despite improvements in noninvasive diagnostic techniques, angiography still remains an important tool for examining this group of patients.

Mechanism of A-kinase-anchoring protein 79 (AKAP79) and protein kinase C interaction.

The A-kinase-anchoring protein AKAP79 co-ordinates the location of cAMP-dependent protein kinase, phosphatase 2B (PP2B/calcineurin) and protein kinase C (PKC) at postsynaptic sites in neurons. In this report we focus on the mechanism of interaction between AKAP79 and PKC. We show that neither lipid activators nor kinase activation are required for association with AKAP79. The anchoring protein binds and inhibits the conserved catalytic core of PKCbetaII. AKAP79 also associates with conventional, novel and atypical isoforms of PKC in vitro and in vivo, and immunofluorescence staining of rat hippocampal neurons demonstrates that the murine anchoring-protein homologue AKAP150 is co-distributed with PKCalpha/beta, PKCepsilon or PKCiota. Binding of the AKAP79(31-52) peptide, which inhibits kinase activity, exposes the pseudosubstrate domain of PKCbetaII, allowing endoproteinase Arg-C proteolysis in the absence of kinase activators. Reciprocal experiments have identified two arginine residues at positions 39 and 40 that are essential for AKAP79(31-52) peptide inhibition of PKCbetaII. Likewise, the same mutations in the full-length anchoring protein reduced inhibition of PKCbetaII. Thus AKAP79 associates with multiple PKC isoforms through a mechanism involving protein-protein interactions at the catalytic core where binding of the anchoring protein inhibits kinase activity through displacement of the pseudosubstrate.

Choledochoscopic stone removal through a T-tube tract: experience in 75 consecutive patients.

Retained biliary stones remain a common clinical problem in patients after surgery. Since 1984, the authors have used choledochoscopy in the treatment of suspected retained biliary stones in 75 patients. These procedures were performed in the radiology department with use of local anesthesia supplemented by an intravenously administered sedative and analgesic. A 15-F flexible fiberoptic choledochoscope was used. Fifty-one of the 75 patients were treated as outpatients. Treatment was successful in 74 of 75 patients; in one patient, intrahepatic stones were not completely removed. Electrohydraulic lithotripsy was used to fragment calculi in 11 patients (15%). Biopsies were performed in four patients (5%). Five minor complications occurred; three required overnight admission. Choledochoscopic-assisted removal of retained biliary calculi is a highly effective and safe procedure. Advantages over standard fluoroscopic stone removal include the ability to directly visualize and fragment adherent or impacted stones and visualize noncalculous filling defects, such as air bubbles, mucus, and biliary tumors.