Relationships that Heal: Beyond the Patient-Healer Dyad in Mayan Therapy

Biomedicine fosters particular styles of interaction and behaviors, with the therapeutic relationship seen as occurring between a doctor and patient. In contrast, where alternative modalities of healing are practiced, relationships go beyond a dyadic interaction and include wider social networks. In this article, we propose the existence of a ‘therapeutic unit’ in Maya healing practices in Guatemala that binds healer, wellness seeker, family, and community members, along with the spiritual and natural realms, into a coherent system requiring all of these elements to achieve success. Drawing on interviews with 67 Maya healers, we describe healers’ understanding of raxnaq’il nuk’aslemal (well-being), and show how these interactions activate wider networks that play crucial roles during treatments. We highlight how holism is expressed in relationships typical of indigenous healing systems, and how an appreciation of this is important for developing culturally appropriate health care provision systems.     

Diagnostic challenges for a novel SH2D1A mutation associated with X‐linked lymphoproliferative disease

Mutations in SH2D1A, encoding the intracellular adaptor signaling lymphocyte activation molecule associated protein (SAP), are associated with X‐linked lymphoproliferative disease type 1 (XLP1). We identified a novel hemizygous SH2D1A c.49G > A (p.E17K) variant in a 21‐year‐old patient with fatal Epstein‐Barr virus infection–associated hemophagocytic lymphohistiocytosis. Cellular and biochemical assays revealed normal expression of the SAP variant protein, yet binding to phosphorylated CD244 receptor was reduced by >95%. Three healthy brothers carried the SH2D1A c.49G > A variant. Thus, data suggest that this variant represents a pathogenic mutation, but with variable expressivity. Importantly, our results highlight challenges in the clinical interpretation of SH2D1A variants and caution in using functional flow cytometry assays for the diagnosis of XLP1.     

Continuously moving table 3D MRI with lateral frequency-encoding direction.

A method is presented for 3D MRI in an extended field of view (FOV) based on continuous motion of the patient table and an efficient acquisition scheme. A gradient-echo MR pulse sequence is applied with lateral (left-right (L/R)) frequency-encoding direction and slab selection along the direction of motion. Compensation for the table motion is achieved by a combination of slab tracking and data alignment in hybrid space. The method allows fast k-space coverage to be achieved, especially when a short sampling FOV is chosen along the direction of table motion, as is desirable for good image quality. The method can be incorporated into different acquisitions schemes, including segmented k-space scanning, which allows for contrast variation with the use of magnetization preparation. Head-to-toe images of volunteers were obtained with good quality using 3D spoiled gradient-echo sequences. As an example of magnetization-prepared imaging, fat/water separated images were acquired using chemical shift selective (CHESS) presaturation pulses.     

The Membrane Lipid Cholesterol Modulates Anesthetic Actions on a Human Brain Ion Channel

Background: Molecular theories of general anesthesia often are divided into two categories: (l) Anesthetics may bind specifically to proteins, such as ionic channels, and alter their function directly, and (2) anesthetics may alter the functions of integral membrane proteins indirectly through modification of the physical properties of the membrane. Recent studies have provided evidence that anesthetics can bind to proteins and modify their function directly, bringing into question the role of the membrane in anesthetic interactions. To reexamine the role of membrane lipids in anesthetic interactions, an experimental approach was used in which the membrane lipid composition could be systematically altered and the impact on anesthetic interactions with potential targets examined.

Methods: Sodium channels from human brain cortex were incorporated into planar lipid bilayers with increasing cholesterol content. The anesthetic suppression of these channels by pentobarbital was quantitatively examined by single channel measurements under voltage-clamp conditions.

Results: Changes in cholesterol content had no effect on measured channel properties in the absence of anesthetic. In the presence of pentobarbital, however, cholesterol inhibited anesthetic suppression of channel ionic currents, with 1.9% (weight/weight, corresponding to 3.5 mol%) cholesterol decreasing anesthetic suppression of sodium channels by half.