Yttrium-90 Radiation Segmentectomy in Oligometastatic Secondary Hepatic Malignancies

PURPOSE

To evaluate the safety and efficacy of yttrium-90 (⁹⁰Y) radiation segmentectomy (RS) in the treatment of oligometastatic secondary hepatic malignancies.

MATERIALS AND METHODS

This institutional review board-approved retrospective study evaluated 16 patients with oligometastatic secondary hepatic malignancies who were treated with RS. The median patient age was 61.9 years (range, 38.6-85.7 years). Of the 16 patients, 11 (68.8%) presented with solitary lesions. The median index tumor size was 3.1 cm (95% CI, 2.3-3.9). Primary outcomes were evaluation of clinical and biochemical toxicities using National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0, and imaging response using Response Evaluation Criteria in Solid Tumors, version 1.1. Secondary outcomes were time to progression (TTP) and overall survival (OS) as estimated by the Kaplan-Meier method.

RESULTS

Clinical Grade 3 toxicities were limited to 1 (6.7%) patient who experienced fatigue, abdominal pain, nausea, and vomiting. Biochemical Grade 3 toxicities occurred in 1 (6.7%) patient who experienced lymphopenia. No Grade 4 clinical or biochemical toxicities were identified. Disease control was achieved in 14 (93.3%) of 15 patients. The median TTP of the treated tumor was 72.9 months (95% CI, 11.2 to no estimate). The median OS was 60.9 months (95% CI, 24.7 to no estimate).

CONCLUSIONS

⁹⁰Y RS displayed an excellent safety profile and was effective in achieving a high disease control rate in the treatment of oligometastatic secondary hepatic malignancies.

NMDAR-Activated PP1 Dephosphorylates GluN2B to Modulate NMDAR Synaptic Content

In mature neurons, postsynaptic N-methyl-D-aspartate receptors (NMDARs) are segregated into two populations, synaptic and extrasynaptic, which differ in localization, function, and associated intracellular cascades. These two pools are connected via lateral diffusion, and receptor exchange between them modulates synaptic NMDAR content. Here, we identify the phosphorylation of the PDZ-ligand of the GluN2B subunit of NMDARs (at S1480) as a critical determinant in dynamically controlling NMDAR synaptic content. We find that phosphorylation of GluN2B at S1480 maintains NMDARs at extrasynaptic membranes as part of a protein complex containing protein phosphatase 1 (PP1). Global activation of NMDARs leads to the activation of PP1, which mediates dephosphorylation of GluN2B at S1480 to promote an increase in synaptic NMDAR content. Thus, PP1-mediated dephosphorylation of the GluN2B PDZ-ligand modulates the synaptic expression of NMDARs in mature neurons in an activity-dependent manner, a process with profound consequences for synaptic and structural plasticity, metaplasticity, and synaptic neurotransmission.

The dynamic regulation of synaptically expressed NMDA receptors (NMDARs) is essential for synaptic function. Here, Chiu et al. describe a mechanism controlling this process in mature neurons by showing that increases in NMDAR synaptic content are driven by PP1-mediated dephosphorylation of extrasynaptic NMDARs within their GluN2B PDZ-ligands.

An Antibody Feeding Approach to Study Glutamate Receptor Trafficking in Dissociated Primary Hippocampal Cultures

Cellular responses to external stimuli heavily rely on the set of receptors expressed at the cell surface at a given moment. Accordingly, the population of surface-expressed receptors is constantly adapting and subject to strict mechanisms of regulation. The paradigmatic example and one of the most studied trafficking events in biology is the regulated control of the synaptic expression of glutamate receptors (GluRs). GluRs mediate the vast majority of excitatory neurotransmission in the central nervous system and control physiological activity-dependent functional and structural changes at the synaptic and neuronal levels (e.g., synaptic plasticity). Modifications in the number, location, and subunit composition of surface expressed GluRs deeply affect neuronal function and, in fact, alterations in these factors are associated with different neuropathies. Presented here is a method to study GluR trafficking in dissociated hippocampal primary neurons. An "antibody-feeding" approach is used to differentially visualize GluR populations expressed at the surface and internal membranes. By labeling surface receptors on live cells and fixing them at different times to allow for receptors endocytosis and/or recycling, these trafficking processes can be evaluated and selectively studied. This is a versatile protocol that can be used in combination with pharmacological approaches or overexpression of altered receptors to gain valuable information about stimuli and molecular mechanisms affecting GluR trafficking. Similarly, it can be easily adapted to study other receptors or surface expressed proteins.

Role of vasoactive intestinal peptide in the light input to the circadian system

The neuropeptide vasoactive intestinal peptide (VIP) is expressed at high levels in a subset of neurons in the ventral region of the suprachiasmatic nucleus (SCN). While VIP is known to be important for the synchronization of the SCN network, the role of VIP in photic regulation of the circadian system has received less attention. In the present study, we found that the light-evoked increase in electrical activity in vivo was unaltered by the loss of VIP. In the absence of VIP, the ventral SCN still exhibited N-methyl-d-aspartate-evoked responses in a brain slice preparation, although the absolute levels of neural activity before and after treatment were significantly reduced. Next, we used calcium imaging techniques to determine if the loss of VIP altered the calcium influx due to retinohypothalamic tract stimulation. The magnitude of the evoked calcium influx was not reduced in the ventral SCN, but did decline in the dorsal SCN regions. We examined the time course of the photic induction of Period1 in the SCN using in situ hybridization in VIP-mutant mice. We found that the initial induction of Period1 was not reduced by the loss of this signaling peptide. However, the sustained increase in Period1 expression (after 30 min) was significantly reduced. Similar results were found by measuring the light induction of cFOS in the SCN. These findings suggest that VIP is critical for longer-term changes within the SCN circuit, but does not play a role in the acute light response.

Human multipotent stromal cells (MSCs) increase neurogenesis and decrease atrophy of the striatum in a transgenic mouse model for Huntington's disease

Background

Implantation of human multipotent stromal cells from bone marrow (hMSCs) into the dentate gyrus of the hippocampus of mice was previously shown to stimulate proliferation, migration and neural differentiation of endogenous neural stem cells. We hypothesized that hMSCs would be beneficial in a mouse model of Huntington disease (HD) due to these neurogenic effects.

Results

We implanted hMSCs into the striatum of transgenic mice (N171-82Q) that are a model for HD. The implanted hMSCs rapidly disappeared over 3 to 15 days. However, they increased proliferation and neural differentiation of endogenous neural stem cells for up to 30 days. They also increased neurotrophic signaling and decreased atrophy of the striatum in 3-month old HD mice implanted with hMSCs one month earlier.

Conclusions

The results therefore suggested that neural implantation of hMSCs may be of benefit in HD but a number of parameters of dose, treatment schedule, and route of administration need to be optimized.

3-D image guidance for minimally invasive robotic coronary artery bypass

BACKGROUND

The introduction of a robot-assisted microsurgical system has made endoscopic coronary artery bypass grafting (ECABG) possible. Despite the success of this approach, surgeons still require better visualization tools for pre-surgical planning and intra-operative image guidance. Such visualization tools could, for example, assist in the placement of thoracic ports to acquire optimum access to the target vessels. In this paper we discuss the essential steps toward image-guided completely endoscopic coronary bypass surgery with robot assistance, and we present our preliminary efforts toward the development of a three-dimensional (3-D) virtual cardiac surgical planning platform (VCSP) for ECABG.

METHODS

Preoperative 3-D images of the thorax acquired with computed tomography and electrocardiogram-gated magnetic resonance imaging are imported into VCSP. Using VCSP, a user may interactively visualize and manipulate the simulated thoracic ports in 3-D within the reconstructed thoracic region. We have also implemented a virtual endoscope to simulate the endoscopic view observed by the surgeon during the operation. Once the port placements for optimal access to the target vessels are determined, the positions of the simulated tools can be recorded and marked on the patient to specify the positions for port incisions.

RESULTS

A static thorax phantom was used to verify the port placements obtained from VCSP simulations. The angles and the distances between the ports, the endoscope and the markers that were placed on the surface of the phantom were measured, and the results were compared with those obtained from simulation. The physical measured distances and angles agreed with the simulated results with average errors of 4 mm and 2 degrees, respectively.

CONCLUSIONS

The VCSP image-guided surgical system allows a surgeon to visualize a patient's thorax in a 3-D interactive environment for planning surgical procedures, and to determine the optimum port placement based on preoperative 3-D images. However, during an operation, the positions and orientation of the heart and the coronary arteries are changed from their corresponding locations in the preoperative images due to carbon-dioxide insufflation, lung deflation, and dynamic motions of the beating heart. One of our future goals of this project is the use of mathematical models that correct for these changes so that our system could be applied to intra-operative image guidance.

Anaphylaxis to dill

BACKGROUND

Allergic symptoms caused by spices and herbs are infrequent and usually mild, although occasionally, severe allergic reactions do occur. Symptoms of pruritus, rhinitis, cough, and edema have been reported to spices including curry, paprika, pepper, and mustard. To our knowledge, this is the first case of confirmed dill allergy, and the patient had severe allergic symptoms.

OBJECTIVE

It is important to alert physicians to the possibility of allergic reactions caused by dill.

METHODS AND RESULTS

The patient, who has a history of allergic rhinitis, developed symptoms of oral pruritus, tongue and throat swelling, urticaria, and immediate vomiting and diarrhea following ingestion of foods cooked with dill and subsequently with inhalation of foods prepared with dill. Skin testing with fresh dill preparation was positive.

CONCLUSION

These findings confirm that dill can cause IgE-mediated reactions.

Minocycline treatment and pseudotumor cerebri syndrome

PURPOSE

To demonstrate the association between minocycline treatment and development of the pseudotumor cerebri syndrome.

METHODS

A retrospective study was conducted of 12 patients from five neuro-ophthalmic referral centers who developed pseudotumor cerebri syndrome after being treated with standard doses of minocycline for refractory acne vulgaris. The main outcome measures included resolution of headaches, transient visual obscurations, diplopia, papilledema, and visual fields static thresholds after withdrawal of minocycline and treatment for increased intracranial pressure.

RESULTS

Nine (75%) of the 12 patients developed symptoms of the pseudotumor cerebri syndrome syndrome within 8 weeks of starting minocycline therapy; six were not obese. Two patients developed symptoms only after a year had elapsed because of commencement of treatment with minocycline. One patient was asymptomatic, and pseudotumor cerebri syndrome was diagnosed by finding papilledema on routine examination 1 year after minocycline was started. None of the patients developed recurrences for at least 1 year after the discontinuation of minocycline and treatment for increased intracranial pressure, but three (25%) of the 12 patients had substantial residual visual field loss.

CONCLUSION

Minocycline is a cause or precipitating factor in pseudotumor cerebri syndrome. Although most patients have prominent symptoms and are diagnosed promptly, others are asymptomatic and may have optic disk edema for a long period of time before diagnosis. Withdrawal of minocycline and treatment for increased intracranial pressure lead to resolution of the pseudotumor cerebri syndrome, but visual field loss may persist.

HPLC analysis of an amino bisphosphonate in pharmaceutical formulations using postcolumn derivatization and fluorescence detection

Monosodium 4-amino-1-hydroxybutane-1, 1-diphosphonic acid (MK-217) is a bone resorption inhibitor implicated in the treatment of malignant hypercalcemia. This compound is very water soluble and has five ionizable groups with pKa values over the entire pH range. As a result, it is difficult to maintain a single species in solution for chromatographic separation. Since there is no chromophore in the molecular structure, UV detection is ineffective. The compound and its potential degradation products are separated by ion-pair chromatography using 0.01 M cetyltrimethylammonium bromide as the ion-pairing agent and a polymeric stationary phase. Detection is by fluorescence detection after postcolumn derivatization of the primary amine with ophthalaldehyde and mercaptoethanol (OPA-MERC). Optimization of the chromatographic separation and the postcolumn reaction has been carried out, and the method has been applied to the analysis of MK-217 in intravenous solutions and tablet formulations.

3,4-Dihydro-2H-1-benzopyran-2-carboxylic acids and related compounds as leukotriene antagonists

Evaluation of a series of 3,4-dihydro-2H-1-benzopyran-2-carboxylic acids linked to the 2-hydroxyacetophenone pharmacophore present in the standard peptidoleukotriene antogonist FPL 55712 (1) has led to the discovery of Ro 23-3544 (7), an antagonist possessing greater potency and duration of action vs LTD4 than the standard (aerosol route of administration, guinea pig bronchoconstriction model). Interestingly, this compound also potently inhibited bronchoconstriction induced by LTB4 whereas 1 did not. Attempts to establish structure--activity relationships in this series involved modifications in the 2-hydroxyacetophenone moiety, the linking chain, and the chroman system. All variations produced analogues which were either inactive or possessed reduced potency relative to acid 7. Optical resolution of 7 was achieved by two methods. Absolute configurations of the enantiomers were determined via X-ray crystallographic analyses of an intermediate as well as a salt of the S enantiomer. Although the enantiomers exhibited similar potencies in in vitro assays and in vivo when administered intravenously, significant differences were observed in the guinea pig bronchoconstriction model vs LTC4 and LTD4 when administered by the aerosol route (S antipode 15-fold more potent). The properties of 7 have been compared with several recently reported leukotriene antagonists.