Hepatic Ablation Promotes Colon Cancer Metastases in an Immunocompetent Murine Model.

OBJECTIVE: To determine the impact of radiofrequency (RF) and microwave (MW) energy compared to direct cautery on metatstatic colon cancer growth. BACKGROUND: Hepatic ablation with MW and RF energy creates a temperature gradient around a target site with temperatures known to create tissue injury and cell death. In contrast, direct heat application (cautery) vaporizes tissue with a higher site temperature but reduced heat gradient on surrounding tissue. We hypothesize that different energy devices create variable zones of sublethal injury that may promote tumor recurrence. To test this hypothesis we applied MW, RF, and cautery to normal murine liver with a concomitant metastatic colon cancer challenge. METHODS: C57/Bl6 mice received hepatic thermal injury with MW, RF, or cautery to create a superficial 3-mm lesion immediately after intrasplenic injection of 50K MC38 colon cancer cells. Thermal imaging recorded tissue temperature during ablation and for 10 seconds after energy cessation. Hepatic tumor location and volume was determined at day 7. RESULTS: Cautery demonstrated the highest maximum tissue temperatures (129°C) with more rapid return to baseline compared to MW or RF energy. All mice had metastasis at the ablation site. Mean tumor volume was significantly greater in the MW (95.3 mm; P = 0.007) and RF (55.7 mm; P = 0.015) than cautery (7.13 mm). There was no difference in volume between MW and RF energy (P = 0.2). CONCLUSIONS: Hepatic thermal ablation promotes colon cancer metastasis at the injury site. MV and RF energy result in greater metastatic volume than cautery. These data suggest that the method of energy delivery promotes local metastasis.

Instrument-Assisted Soft-Tissue Mobilization for the Management of Chronic Plantar Heel Pain: A Pilot Study.

BACKGROUND: The purpose of this study was to determine feasibility of further investigation of treatment with instrument-assisted soft-tissue mobilization (IASTM), using the Graston technique, compared with conservative care for treatment of chronic plantar heel pain (CPHP). METHODS: Eleven participants with plantar heel pain lasting 6 weeks to 1 year were randomly assigned to one of two groups, with each group receiving up to eight physical therapy visits. Both groups received the same stretching, exercise, and home program, but the experimental group also received IASTM using the Graston technique. Outcome measures of pain and function were recorded at baseline, after final treatment, and 90 days later. Feasibility of a larger study was determined considering recruitment and retention rates, compliance, successful application of the protocol and estimates of the treatment effect. RESULTS: Both groups demonstrated improvements in current pain (pain at time of survey), pain with the first step in the morning, and function after final treatment and at 90-day follow up. Medium-to-large effect sizes between groups were noted, and sample size estimates demonstrated a need for at least 42 participants to realize a group difference. A larger-scale study was determined to be feasible with modifications including a larger sample size and higher recruitment rate. CONCLUSIONS: This pilot study demonstrates that inclusion of IASTM using the Graston technique for CPHP lasting longer than 6 weeks is a feasible intervention warranting further study. Clinically important changes in the IASTM group and moderate-to-large between-group effect sizes suggest that further research is warranted to determine whether these trends are meaningful.

Adding interventions to mass measles vaccinations in India.

OBJECTIVE: To quantify the impact on mortality of offering a hypothetical set of technically feasible, high-impact interventions for maternal and child survival during India's 2010-2013 measles supplementary immunization activity. METHODS: We developed Lives Saved Tool models for 12 Indian states participating in the supplementary immunization, based on state- and sex-specific data on mortality from India's Million Deaths Study and on health services coverage from Indian household surveys. Potential add-on interventions were identified through a literature review and expert consultations. We quantified the number of lives saved for a campaign offering measles vaccine alone versus a campaign offering measles vaccine with six add-on interventions (nutritional screening and complementary feeding for children, vitamin A and zinc supplementation for children, multiple micronutrient and calcium supplementation in pregnancy, and free distribution of insecticide-treated bednets). FINDINGS: The measles vaccination campaign saved an estimated 19 016 lives of children younger than 5 years. A hypothetical campaign including measles vaccine with add-on interventions was projected to save around 73 900 lives (range: 70 200-79 300), preventing 73 700 child deaths (range: 70 000-79 000) and 300 maternal deaths (range: 200-400). The most effective interventions in the whole package were insecticide-treated bednets, measles vaccine and preventive zinc supplementation. Girls accounted for 66% of expected lives saved (12 712/19 346) for the measles vaccine campaign, and 62% of lives saved (45 721/74 367) for the hypothetical campaign including add-on interventions. CONCLUSION: In India, a measles vaccination campaign including feasible, high-impact interventions could substantially increase the number of lives saved and mitigate gender-related inequities in child mortality.

Integrated renal care: are nephrologists ready for change in renal care delivery models?

The Affordable Care Act is the most visible element of health care reform. However, both before the Affordable Care Act and now with the acceleration since its passage, the Centers for Medicare and Medicaid have been and are testing integrated care models in medicine in general as well as nephrology. The pressures to do so come from the well known increasing costs of health care in the face of a number of clear gaps in quality. The future will likely be more and more integrated care with less and less fee for service. More measurement of quality and the linking of quality measures to payments are also all but certain future elements of the health care economy. Nephrologists need to educate themselves on these trends and be prepared to engage them for the good of the profession and the improvement in care for patients.

Low-threshold calcium channel subunit Ca(v) 3.3 is specifically localized in GABAergic neurons of rodent thalamus and cerebral cortex.

Relatively little is known about the subcellular localization of low threshold Ca²+ channels (T-channels) in the brain. Using immunocytochemical labeling and preembedding immunoperoxidase and silver-enhanced immunogold electron microscopy, we localized T-channel subunit Ca(v) 3.3 in rodent cerebral cortex and thalamus. Double immunofluorescent staining demonstrated that Ca(v) 3.3-labeled neurons in cerebral cortex are a subgroup of GABAergic interneurons that coexpress calbindin and in half of the cases parvalbumin. In the thalamus, virtually all reticular nucleus (RTN) neurons were immunopositive for Ca(v) 3.3, while neurons in dorsal thalamic nuclei were nonimmunoreactive. At the electron microscopic (EM) level, in cortical layers IV-V and RTN neurons, Ca(v) 3.3 immunoreactivity was mainly associated with membranes of dendrites but with some localization in cytoplasm. None was found in axon terminals. In cortex, ≈73% of immunogold particles were present in close proximity to synaptic contacts (<0.5 µm from the postsynaptic density), while 27% were distributed along membranes at extrasynaptic sites (>0.5 µm from the postsynaptic density). In RTN, ≈57% particles were evenly distributed along perisynaptic membranes and the remaining 43% of particles were diffusely localized at extrasynaptic membranes. The density of particles along the dendritic membranes of cortical neurons was 40% higher than in RTN neurons. These results suggest that Ca(v) 3.3 plays a role in regulating GABAergic neurons whose actions underlie thalamocortical rhythmicity.

Expression patterns of corticotropin-releasing factor, arginine vasopressin, histidine decarboxylase, melanin-concentrating hormone, and orexin genes in the human hypothalamus.

The hypothalamus regulates numerous autonomic responses and behaviors. The neuroactive substances corticotropin-releasing factor (CRF), arginine-vasopressin (AVP), histidine decarboxylase (HDC), melanin-concentrating hormone (MCH), and orexin/hypocretins (ORX) produced in the hypothalamus mediate a subset of these processes. Although the expression patterns of these genes have been well studied in rodents, less is known about them in humans. We combined classical histological techniques with in situ hybridization histochemistry to produce both 2D and 3D images and to visually align and quantify expression of the genes for these substances in nuclei of the human hypothalamus. The hypothalamus was arbitrarily divided into rostral, intermediate, and caudal regions. The rostral region, containing the paraventricular nucleus (PVN), was defined by discrete localization of CRF- and AVP-expressing neurons, whereas distinct relationships between HDC, MCH, and ORX mRNA-expressing neurons delineated specific levels within the intermediate and caudal regions. Quantitative mRNA signal intensity measurements revealed no significant differences in overall CRF or AVP expression at any rostrocaudal level of the PVN. HDC mRNA expression was highest at the level of the premammillary area, which included the dorsomedial and tuberomammillary nuclei as well as the dorsolateral hypothalamic area. In addition, the overall intensity of hybridization signal exhibited by both MCH and ORX mRNA-expressing neurons peaked in distinct intermediate and caudal hypothalamic regions. These results suggest that human hypothalamic neurons involved in the regulation of the HPA axis display distinct neurochemical patterns that may encompass multiple local nuclei.

Synchrony in the interconnected circuitry of the thalamus and cerebral cortex.

The corticothalamic system is organized to play a key role in synchronizing the activities of thalamic and cortical neurons. Its synapses dominate the inputs to relay cells and to the GABAergic cells of the reticular nucleus; its organization in focused and diffuse projections promotes both coherent activity of relay neurons and the spread of activity across the cortex and thalamus. The capacity of relay neurons to operate in voltage-dependent tonic or burst mode permits corticothalamic inputs to directly excite the relay cells or indirectly inhibit them via the reticular nucleus. This enables the corticothalamic projection to synchronize high- or low-frequency oscillatory activity, respectively, in the thalamo-corticothalamic network. Differences in the subunit composition of AMPA receptors at synapses formed by branches of the same corticothalamic axon in the reticular nucleus and dorsal thalamus are an important element in the capacity of the cortex to synchronize low-frequency oscillations in the network. Intrinsic voltage-gated calcium channels of different kinds expressed in the relay neurons form a substrate for corticothalamic interactions with the relay cells that promote high- or low-frequency oscillations. Focused corticothalamic axons arising from layer VI cortical cells and diffuse corticothalamic axons arising from layer V cortical cells, in conjunction with the core and matrix cells of the dorsal thalamus, form a substrate for synchronization of widespread populations of cortical and thalamic cells during high-frequency oscillations that underlie discrete conscious events.

Early withdrawal of axons from higher centers in response to peripheral somatosensory denervation.

The mechanisms responsible for long-term, massive reorganization of representational maps in primate somatosensory cortex after deafferentation are poorly understood. Sprouting of cortical axons cannot account for the extent of reorganization, and withdrawal of axons of deafferented brainstem and thalamic neurons, permitting expression of previously silent synapses, has not been directly demonstrated. This study is focused on the second of these. In monkeys, deafferented for two years by section of the cuneate fasciculus at the C1 level, there was extensive withdrawal of axon terminals from thalamus and cortex, detectable a decade before visible atrophy of their parent neuronal somata in the cuneate nucleus or thalamus. Slow, inexorable progression of lemniscal and thalamocortical axonal withdrawal is a neurodegenerative phenomenon likely to be a powerful inducement to compensatory long-term plasticity, a mechanism that can explain the long-term evolution of cortical reorganization and, with it, phantom sensations in spinal patients and amputees.

Vesicular glutamate transporters define two sets of glutamatergic afferents to the somatosensory thalamus and two thalamocortical projections in the mouse.

The ventral posterior nucleus of the thalamus (VP) receives two major sets of excitatory inputs, one from the ascending somatosensory pathways originating in the dorsal horn, dorsal column nuclei, and trigeminal nuclei, and the other originating from the cerebral cortex. Both systems use glutamate as neurotransmitter, as do the thalamocortical axons relaying somatosensory information from the VP to the primary somatosensory cortex (SI). The synapses formed by these projection systems differ anatomically, physiologically, and in their capacity for short-term synaptic plasticity. Glutamate uptake into synaptic vesicles and its release at central synapses depend on two isoforms of vesicular glutamate transporters, VGluT1 and VGluT2. Despite ample evidence of their complementary distribution, some instances exist of co-localization in the same brain areas or at the same synapses. In the thalamus, the two transcripts coexist in cells of the VP and other nuclei but not in the posterior or intralaminar nuclei. We show that the two isoforms are completely segregated at VP synapses, despite their widespread expression throughout the dorsal and ventral thalamus. We present immunocytochemical, ultrastructural, gene expression, and connectional evidence that VGluT1 in the VP is only found at corticothalamic synapses, whereas VGluT2 is only found at terminals made by axons originating in the spinal cord and brainstem. By contrast, the two VGluT isoforms are co-localized in thalamocortical axon terminals targeting layer IV, but not in those targeting layer I, suggesting the presence of two distinct projection systems related to the core/matrix pattern of organization of thalamocortical connectivity described in other mammals.

The thalamus of the monotremes: cyto- and myeloarchitecture and chemical neuroanatomy.

Echidna and platypus brains were sectioned and stained by Nissl or myelin stains or immunocytochemically for calcium-binding proteins, gamma aminobutyric acid (GABA) or other antigens. Cyto- and myeloarchitecture revealed thalami that are fundamentally mammalian in organization, with the three principal divisions of the thalamus (epithalamus, dorsal thalamus and ventral thalamus) identifiable as in marsupials and eutherian mammals. The dorsal thalamus exhibits more nuclear parcellation than hitherto described, but lack of an internal medullary lamina, caused by splaying out of afferent fibre tracts that contribute to it in other mammals, makes identification of anterior, medial and intralaminar nuclear groups difficult. Differentiation of the ventral nuclei is evident with the ventral posterior nucleus of the platypus enormously expanded into the interior of the cerebral hemisphere, where it adopts a relationship to the striatum not seen in other mammals. Other nuclei such as the lateral dorsal become identifiable by expression of patterns of calcium-binding proteins identical to those found in other mammals. GABA cells are present in the ventral and dorsal thalamic nuclei, and in the ventral thalamus form a remarkable continuum with GABA cells of the two segments of the globus pallidus and pars reticulata of the substantia nigra.

Nucleus- and cell-specific gene expression in monkey thalamus.

Nuclei of the mammalian thalamus are aggregations of neurons with unique architectures and input-output connections, yet the molecular determinants of their organizational specificity remain unknown. By comparing expression profiles of thalamus and cerebral cortex in adult rhesus monkeys, we identified transcripts that are unique to dorsal thalamus or to individual nuclei within it. Real-time quantitative PCR and in situ hybridization analyses confirmed the findings. Expression profiling of individual nuclei microdissected from the dorsal thalamus revealed additional subsets of nucleus-specific genes. Functional annotation using Gene Ontology (GO) vocabulary and Ingenuity Pathways Analysis revealed overrepresentation of GO categories related to development, morphogenesis, cell-cell interactions, and extracellular matrix within the thalamus- and nucleus-specific genes, many involved in the Wnt signaling pathway. Examples included the transcription factor TCF7L2, localized exclusively to excitatory neurons; a calmodulin-binding protein PCP4; the bone extracellular matrix molecules SPP1 and SPARC; and other genes involved in axon outgrowth and cell matrix interactions. Other nucleus-specific genes such as CBLN1 are involved in synaptogenesis. The genes identified likely underlie nuclear specification, cell phenotype, and connectivity during development and their maintenance in the adult thalamus.

Bilateral thalamic lesions affect recollection- and familiarity-based recognition memory judgments.

The contribution of the thalamus to different forms of explicit memory is poorly understood. In the current study, explicit memory performance was examined in a 40-year-old male (RG) with bilateral anterior and medial thalamic lesions. Standardized tests indicated that the patient exhibited more severe recall than recognition deficits and his performance was generally worse for verbal compared to nonverbal memory. Recognition memory tests using the remember-know (R/K) procedure and the confidence-based receiver operating characteristic (ROC) procedure were used to examine recollection- and familiarity-based recognition. These tests revealed that RG had deficits in recollection and smaller, but consistent deficits in familiarity. The results are in agreement with models indicating that the anteromedial thalamus is important for both recollection- and familiarity-based recognition memory.

Switching of NMDA receptor 2A and 2B subunits at thalamic and cortical synapses during early postnatal development.

Switching of the NMDA receptor 2A (NR2A) and NR2B subunits at NMDA receptors is thought to underlie the functional changes that occur in NMDA receptor properties during the developmental epoch when neural plasticity is most pronounced. The cellular expression of NR2A and NR2B and the NR2 synaptic binding protein postsynaptic density-95 (PSD-95) was examined in the mouse somatosensory cortex and thalamus from postnatal day 2 (P2) to P15 using reverse transcription-PCR, in situ hybridization histochemistry, and immunocytochemistry. The localization of NR2A and NR2B subunits and PSD-95 was then studied at synapses in layer IV of somatosensory cortex and in the ventral posterior nucleus of the thalamus using high-resolution immunoelectron microscopy. At both cortical and thalamic synapses, a quantitative switch in the dominant synaptic subunit from NR2B to NR2A was accompanied by a similar change in the cellular expression of NR2A but not of NR2B. Synaptic PSD-95 developed independently, although both NR2A and NR2B colocalized with PSD-95. Displacement of NR2B subunits from synapses was not accompanied by an increase in an extrasynaptic pool of this subunit. Thus, the switch in synaptic NR2 subunit predominance does not occur by changes in expression or displacement from synapses and may reflect the formation of new synapses from which NR2B is lacking.

Histological analysis of the location of effective thalamic stimulation for tremor. Case report.

Chronic electrical stimulation of the thalamus is an effective treatment for essential and parkinsonian tremor. Although the preferred surgical target is generally accepted to lie within the ventral intermediate nucleus (Vim), the relationship between the surgically defined target and the true histologically defined target is addressed in only a few reports, due in large measure to the need for advanced cytoarchitectonic techniques to define the borders of the thalamic nuclei. The authors report on a patient who underwent effective thalamic deep brain stimulation (DBS) for tremor. By defining the boundaries of the thalamic nuclei, they were able to relate effective DBS to electrode location within the anterior region of the ventral posterior lateral nucleus--the proprioceptive shell of the sensory nucleus--and the posteroventral region of the ventral lateral nucleus, which are equivalent to the Vim defined by Hassler, et al.

Fine structural localization of connexin-36 immunoreactivity in mouse cerebral cortex and thalamus.

The mounting physiological evidence for low-resistance electrical coupling between thalamic and cortical neurons contrasts with a lack of morphological data on gap junctions in thalamus and cortex. Connexin-36 is a neuronally specific protein associated with low-resistance gap junctions in the central nervous system. Connexin-36 localization was studied in the mouse somatosensory cortex and thalamus by using immunocytochemistry and immunoelectron microscopy. Expression of connexin-36 immunoreactivity is widespread in the forebrain and significantly enhanced in the barrel cortex and thalamic reticular nucleus during the second postnatal week, but it extends to other thalamic nuclei as well. At the electron microscopic level, pre- and postembedding immunogold labeling revealed that 70-76% of connexin-36-immunolabeled particles were localized at focal sites on apposed plasma membranes of cortical and thalamic dendrites; approximately 5% of the particles were associated with parasynaptic membranes; but on no occasion could overt, morphologically identifiable gap junctions be demonstrated in association with connexin-36 immunoreactivity. The widespread distribution of focal concentrations of connexin-36 subunits could provide a basis for the electrical coupling that exists between cortical and reticular thalamic neurons, but morphologically definable gap junctions may be too small to be adequately visualized by conventional immunoelectron microscopy.

Two epochs in the development of gamma-aminobutyric acidergic neurons in the ferret thalamus.

These studies chart the development of gamma-aminobutyric acid (GABA)-ergic neurons in the three divisions of the thalamus (ventral thalamus, dorsal thalamus, and epithalamus). GABAergic neurons were identified by in situ hybridization to localize mRNA for 67-kDa glutamic acid decarboxylase (GAD(67)) and related to the morphological maturation of the thalamus in fetal and postnatal brains and to expression of transcription factors Gbx-2 and Tbr-1. Origins of GABAergic neurons were sought in in vitro slice preparations incubated in bromodeoxyuridine or injected with a carbocyanine dye. GABA neurons of ventral thalamus (reticular nucleus, ventral lateral geniculate nucleus, zona incerta, and nucleus of the fields of Forel) and of epithalamus appear at least 14 days before those intrinsic to dorsal thalamus. Ventral thalamus GABA cells are derived from a region connecting the ventricular zone of the third ventricle to the caudal ganglionic eminence. This region is delimited ventrally by the Tbr-1-expressing prethalamic eminence and dorsally by the Gbx-2-expressing part of the dorsal thalamus. GABA neurons of epithalamus are derived from the embryonic pretectum. Neurons continue to be added to the ventral thalamus, perireticular nucleus, entopeduncular nucleus, and substantia nigra from the ganglionic eminence as development proceeds. GAD(67)-expressing cells of dorsal thalamus become detectable only at birth and populate the thalamus from posterior to anterior over the first week of life. Although a very small number reaches the dorsal lateral geniculate nucleus from the caudal ganglionic eminence, there is no obvious new source of proliferating neurons at this stage. Intrinsic GABA cells of dorsal thalamus may, therefore, derive from an early generated population of cells that turns on a GABAergic phenotype only late in development.

Neuroanatomical term generation and comparison between two terminologies.

An approach and software tools are described for identifying and extracting compound terms (CTs), acronyms and their associated contexts from textual material that is associated with neuroanatomical atlases. A set of simple syntactic rules were appended to the output of a commercially available part of speech (POS) tagger (Qtag v 3.01) that extracts CTs and their associated context from the texts of neuroanatomical atlases. This "hybrid" parser. appears to be highly sensitive and recognized 96% of the potentially germane neuroanatomical CTs and acronyms present in the cat and primate thalamic atlases. A comparison of neuroanatomical CTs and acronymsbetween the cat and primate atlas texts was initially performed using exact-term matching. The implementation of string-matching algorithms significantly improved the identification of relevant terms and acronyms between the two domains. The End Gap Free string matcher identified 98% of CTs and the Needleman Wunsch (NW) string matcher matched 36% of acronyms between the two atlases. Combining several simple grammatical and lexical rules with the POS tagger ("hybrid parser") (1) extracted complex neuroanatomical terms and acronyms from selected cat and primate thalamic atlases and (2) and facilitated the semi-automated generation of a highly granular thalamic terminology. The implementation of string-matching algorithms (1) reconciled terminological errors generated by optical character recognition (OCR) software used to generate the neuroanatomical text information and (2) increased the sensitivity of matching neuroanatomical terms and acronyms between the two neuroanatomical domains that were generated by the "hybrid" parser.

Thalamic organization and function after Cajal.

Cajal's many contributions to understanding the thalamus have been hidden by his body of work on the cerebral cortex. He delineated many thalamic nuclei in rodents, defined afferent fibers, thalamocortical relay neurons and interneurons, was first to demonstrate thalamocortical fibers and their terminations in the cortex, and recognized the feed-back provided by corticothalamic fibers. This presentation outlines modern methods for identifying classes of thalamic neurons, their chemical characteristics, synaptology and differential connections, and describes the intrinsic circuitry of the thalamus, showing how interactions between GABAergic cells of the reticular nucleus and glutamatergic relay cells underlie rhythmic activities of neurons in the thalamo-cortico-thalamic network, activities associated with changes in the conscious state, and which are generated and maintained by the corticothalamic projection. Corticothalamic fibers interact with reticular nucleus cells and relay cells through NMDA, AMPA and metabotropic receptors while interactions between reticular nucleus cells and relay cells are mediated by GABAA and GABAB receptors. Differing strengths of synaptic input to the two cell types, from which oscillatory behavior commences, depend upon differential expression at individual synapses of specific AMPA receptor subunits which modulate excitatory postsynaptic conductances. Two classes of relay cells can be distinguished by differential staining for calbindin and parvalbumin. The first forms a matrix in the thalamus, unconstrained by nuclear borders; the second is concentrated in certain nuclei in which it forms the topographically organized core. In projecting diffusely to the cortex, calbindin cells provide a substrate for binding together activities of multiple cortical areas that receive focused input from single thalamic nuclei. This, and the presence of specific and diffuse corticothalamic projections may serve to promote coherent activity of large populations of cortical and thalamic neurons in perception, attention and conscious awareness.