An evolutionarily conserved dileucine motif in Shal K+ channels mediates dendritic targeting

The molecular mechanisms underlying polarized sorting of proteins in neurons are poorly understood. Here we report the identification of a 16 amino-acid, dileucine-containing motif that mediates dendritic targeting in a variety of neuronal cell types in slices of rat brain. This motif is present in the carboxy (C) termini of Shal-family K+ channels and is highly conserved from C. elegans to humans. It is necessary for dendritic targeting of potassium channel Kv4.2 and is sufficient to target the axonally localized channels Kv1.3 and Kv1.4 to the dendrites. It can also mediate dendritic targeting of a non-channel protein, CD8.     

Anti-clumping factor A immunoglobulin reduces the duration of methicillin-resistant Staphylococcus aureus bacteremia in an experimental model of infective endocarditis

SA-IGIV is a human polyclonal immunoglobulin containing elevated levels of antibodies specific for the fibrinogen-binding MSCRAMM protein clumping factor A (ClfA). In vitro, SA-IGIV specifically recognized ClfA that was expressed on the surface of Staphylococcus aureus and inhibited bacterial adherence to immobilized human fibrinogen by >95%. Moreover, SA-IGIV efficiently opsonized ClfA-coated fluorescent beads and facilitated phagocytosis by human polymorphonuclear leukocytes. To determine its potential therapeutic efficacy, SA-IGIV was evaluated in combination with vancomycin in a rabbit model of catheter-induced aortic valve infective endocarditis (IE) caused by methicillin-resistant S. aureus (MRSA). The combination therapy was more effective than vancomycin alone in sterilizing all valvular vegetations when used therapeutically during early (12-h) IE. The combination therapy resulted in clearance of bacteremia that was significantly faster than that of vancomycin alone in animals with well-established (24-h) IE. Therefore, in both early and well-established MRSA IE, the addition of SA-IGIV to a standard antibiotic regimen (vancomycin) increased bacterial clearance from the bloodstream and/or vegetations.     

Clinical application of opioid equianalgesic data

Physicians and other healthcare professionals may often be faced with the need to change opioids during the course of a patient's opioid analgesic care due to a number of clinical reasons. The act of converting opioid analgesics, for many physicians, nurses, and pharmacists, who do not receive adequate training, remains a challenging and often uncomfortable aspect of pain treatment. Part of the challenge clinicians face is secondary to the relatively weak literature evidence base that exists to support the equianalgesic ratios provided in textbooks, journals, and other medical resources. Another aspect involves the lack of a widely recognized treatment algorithm or guideline to assist clinicians with opioid conversion. The final decision on which opioid dose to prescribe must involve a thorough clinical assessment to minimize the risk of prescribing inappropriate opioid doses over or under the patient's actual need. The purpose of this paper is to provide the clinician with an approach for dealing with the conversion between opioid analgesics that is standardized, yet allows for individualized results to meet unique patient needs. We present a 5-step process as a guide for clinicians faced with the need to change a patient's opioid regimen. This approach may help to build a comfort level when dealing with the clinical challenges of converting from one opioid to another.     

In vitro-cultivation of human periosteum derived cells in bioresorbable polymer-TCP-composites

Bone replacement materials for reconstruction of bone defects must be biocompatible and biodegradable and must have osteoconductive or even osteogenic potential. Ideally, their shape should also be adaptable to the defect and they should possess long-term adaptability to the biomechanical situation at the implantation site. Human mesenchymal stem cells of the cambium layer of the periosteum were cultivated, placed in a fibrin suspension on a preformed carrier structure (PGLA polymer + beta-TCP), and cultivated under conditions of osteogenic differentiation. After 10, 20, 30, and 40 days, histological examination was performed, alkaline phosphatase activity and levels of osteocalcin, DNA, and collagen were determined, and the influence of addition of TGF-beta1 at a concentration of 5 ng/ml to the culture medium was investigated. Demonstration of bone-specific marker proteins indicated that the in vitro combination of mesenchymal stem cells, PGLA polymer, beta-TCP, and fibrin resulted in de-novo synthesis of human preosseous tissue, while addition of TGF-beta1 resulted in greater new bone formation with significantly higher concentrations of marker proteins. Histological examination showed the presence of newly formed bone at the surface of the implant. As compared with the use of structured TCP or hydroxyapatite implants as in earlier works, use of a combination of autologous cell material, PGLA polymer, and beta-TCP results in a malleable, vital implant that is adaptable to the bone defect. This combination thus may represent a new option for the treatment of bone defects.     

Palliative care curriculum development: a model for a content and process-based approach

To ensure its success, a new curriculum has to meet the needs of learners, patients, and the institution. A review of the literature indicates that despite a tremendous need for palliative care services and a lack of appropriate knowledge and attitudes among physicians, few palliative care curricula for medical residents have been developed. Most are developed by national organizations, and as a result can not meet the individual needs of different institutions. This paper outlines the process of developing a palliative care curriculum in the context of available institutional resources that meets the learners' needs. The development of a curriculum can be divided into four phases: needs assessment, curricular design, implementation, and evaluation. Content (curricular content, instructional strategies and available resources for the curriculum and the developmental process) and process (methods through which the curriculum is developed and institutional issues are addressed) issues that are pertinent to the successful completion of each phase are discussed. Two hypothetical institutions are used to illustrate relevant issues. Methods that have been successfully used to develop residency curricula are discussed.     

Analysis of the nuclear distribution of the translocation t(8;21)-derived fusion protein AML1/ETO by confocal laser scanning microscopy

The AML1/ETO protein derived from the t(8;21) translocation retains the DNA binding domain of AML1, the runt homology domain (RHD), and nearly the complete ETO protein with its four nervy homology regions (NHR1-4). To analyze which domains of AML1/ETO are responsible for its intranuclear transport and its subnuclear distribution, AML1/ETO deletion constructs tagged with green fluorescence protein were expressed transiently in 293 cells. The subcellular distribution was analyzed by confocal laser scanning microscopy. The nuclear localization signal (NLS) of AML1/ETO was mapped to a region encoded by the carboxy-terminal part of NHR1 and the sequences following up to NHR2 corresponding to the amino acids 304-489 of the AML1/ETO protein. A speckled subnuclear distribution was found with those constructs containing the NHR2 and/or the NHR3 and NHR4 domains. Co-localization with AML1/ETO was complete with constructs containing the NHR2 domain, indicating that NHR2 has a crucial role in the subnuclear distribution of AML1/ETO. Co-localization with AML1 seems to be supported by RHD, whereas the NHR3 and NHR4 regions possibly counterbalance this effect. Finally, AML1/ETO could not be co-localized with PML and SUMO-1, indicating that AML1/ETO is not part of the nuclear bodies and probably not SUMOylated.     

Refusing artificial nutrition and hydration: does statutory law send the wrong message?

Ethical consensus and appellate court decisions view artificial nutrition and hydration (ANH) as medical treatment that can be refused like other treatments. However, advance directive statutes may produce obstacles for refusal of ANH, as distinct from other life-sustaining treatments, in patients who lack capacity.This paper reviews state statutes and appellate case law regarding medical decision making for patients who lack decisional capacity. Twenty states (39%) have one or more explicit statutory provisions delineating a separate and more stringent standard for ANH refusal. These standards include higher evidentiary standard; requirement for specific preauthorization, qualifying medical conditions, second medical opinion, or judicial review; refusal not permitted; refusal not permitted if death would result from "starvation" or "dehydration"; and previous law with higher standard applies to old documents. In 11 of these states and in eight others, statutory law contains language that could be misinterpreted, implying, but not rising to, an explicitly higher standard. Four appellate decisions departed from the judicial consensus that ANH can be refused like other treatments, but subsequent court decisions or legislative enactments reduced or eliminated their impact.Legislators and the courts should ask whether higher standards for ANH refusal are appropriate in light of case law authority that ANH should not be treated differently and in light of statutory language that preserves those common law rights. These higher standards may make it more difficult in certain states to refuse ANH for patients who lack capacity or place a burden on good practice by making providers fearful of the law.     

Combination immunotherapy with rituximab and interleukin 2 in patients with relapsed or refractory follicular non-Hodgkin's lymphoma

Rituximab has significant activity as a single agent in the treatment of follicular non-Hodgkin's lymphoma (NHL). Interleukin 2 (IL-2) is a lymphokine that increases effector cell number. In an effort to augment antibody-dependent cell-mediated cytotoxicity (ADCC) associated with rituximab therapy, low-dose IL-2 was added to a standard rituximab regimen and patients were evaluated for safety and efficacy. Twenty patients with relapsed or refractory follicular NHL were treated with IL-2 (1.2 MIU/m(2)/d for 56 d subcutaneously) as outpatients. Rituximab (375 mg/m(2)) was given on d 15, 22, 29 and 36. The regimen was well tolerated and only three patients required dose adjustments in IL-2. Infusional toxicity associated with rituximab was not exacerbated by IL-2. Peripheral blood immunophenotyping demonstrated significant increases in circulating CD8+ and CD56+ lymphocytes in all evaluable patients (P = 0.0002). Increases in total eosinophil number were observed in all patients. Eleven patients responded to therapy, for an overall response rate of 55%. Four additional patients had stable disease. For these 15 patients, the median time to progression exceeded 13 months. We conclude concomitant cytokine therapy to enhance ADCC with monoclonal antibody therapy was well tolerated and did not exacerbate antibody-related infusional toxicity. Further studies of this rational combination are warranted and ongoing.