Increased 99mTc MDP activity in the costovertebral and costotransverse joints on SPECT-CT: is it predictive of associated back pain or response to percutaneous treatment?

PURPOSEPain related to costovertebral and costotransverse joints is likely an underrecognized and potentially important cause of thoracic back pain. On combined single-photon emission computed tomography and computed tomography (SPECT-CT), increased technetium-99m methylene diphosphonate (99mTc MDP) activity at these articulations is not uncommon. We evaluated whether this activity corresponds with thoracic back pain and whether it predicts response to percutaneous injection.METHODSAll 99mTc MDP SPECT-CT spine examinations completed at our institution from March 2008 to March 2014 were retrospectively reviewed to identify those with increased 99mTc MDP activity in the costovertebral or costotransverse joints. The presence of corresponding thoracic back pain, percutaneous injection performed at the relevant joint(s), and response to injection were recorded.RESULTSA total of 724 99mTc MDP SPECT-CT examinations were identified. Increased 99mTc MDP activity at costovertebral or costotransverse joints was reported in the examinations of 55 patients (8%). Of these, 25 (45%) had corresponding thoracic back pain, and nine of 25 patients (36%) underwent percutaneous injection of the joint(s) with increased activity. At clinical follow-up two days to 12 weeks after injection, one patient (11%) had complete pain relief, two (22%) had partial pain relief, and six (67%) had no pain relief.CONCLUSIONThe findings suggest that increased activity in costovertebral and costotransverse joints on 99mTc MDP SPECT-CT is only variably associated with the presence and location of thoracic back pain; it does not predict pain response to percutaneous injection.The findings suggest that increased activity in costovertebral and costotransverse joints on 99mTc MDP SPECT-CT is only variably associated with the presence and location of thoracic back pain; it does not predict pain response to percutaneous injection

Autoradiographic Characterization and Localization of Quisqualate Binding Sites in Rat Brain Using the Antagonist [ 3 H]6-Cyano-7-Nitroquinoxaline-2,3-Dione: Comparison with ( R,S )-[ 3 H]Α-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic Acid Binding Sites

Using quantitative autoradiography, we have investigated the binding sites for the potent competitive non- N -methyl-D-aspartate (non-NMDA) glutamate receptor antagonist [ 3 H]6-cyano-7-nitro-quinoxaline-2,3-dione ([ 3 H]-CNQX) in rat brain sections. [ 3 H]CNQX binding was regionally distributed, with the highest levels of binding present in hippocampus in the stratum radiatum of CA1, stratum lucidum of CA3, and molecular layer of dentate gyrus. Scatchard analysis of [ 3 H]CNQX binding in the cerebellar molecular layer revealed an apparent single binding site with a K D = 67 ± 9.0 n M and B max = 3.56 ± 0.34 pmol/mg protein. In displacement studies, quisqualate, L-glutamate, and kainate also appeared to bind to a single class of sites. However, ( R,S )- Α -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) displacement of [ 3 H]CNQX binding revealed two binding sites in the cerebellar molecular layer. Binding of [ 3 H]AMPA to quisqualate receptors in the presence of potassium thiocyanate produced curvilinear Scatchard plots. The curves could be resolved into two binding sites with K D1 = 9.0 ± 3.5 n M , B max = 0.15 ± 0.05 pmol/mg protein, K D2 = 278 ± 50 n M , and B max = 1.54 ± 0.20 pmol/mg protein. The heterogeneous anatomical distribution of [ 3 H]CNQX binding sites correlated to the binding of L-[ 3 H]glutamate to quisqualate receptors and to sites labeled with [ 3 H]AMPA. These results suggest that the non-NMDA glutamate receptor antagonist [ 3 H]CNQX binds with equal affinity to two states of quisqualate receptors which have different affinities for the agonist [ 3 H]AMPA.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65634/1/j.1471-4159.1990.tb01925.x.pd

Histopathological characterization of intimal lesions and arterial wall calcification in the arteries of the leg of elderly cadavers

Introduction: Although arteries of the leg have been studied in extensively diseased amputation specimens, little is known about the composition of vascular lesions present in the general population. The aim of this study was to describe the natural development of adaptive intimal thickening, atherosclerotic lesion development and vascular calcification in the leg of a general elderly population. Materials and Methods: Two hundred and seventy postmortem samples from the popliteal and posterior tibial arteries of 14 elderly cadavers were studied histologically. Results: Atherosclerotic lesions were more frequently observed in the popliteal (60%) than in the posterior tibial artery (34%; p <.0005). These atherosclerotic plaques were most often nonatheromatous (80% and 83% for popliteal and posterior tibial plaques, respectively). The atheroma's that were present were small (most <25% of plaque area). Atherosclerotic plaque calcification was observed more often in the popliteal (39%) than in the posterior tibial samples (17%; p <.0005). Medial arterial calcification was observed more often in the posterior tibial (62%) than in the popliteal samples (46%; p =.008). Plaque calcification and medial arterial calcification were not associated with lumen stenosis. Conclusions: In the leg of elderly cadavers, the presence of atherosclerotic plaque and intimal calcification decreases from the proximal popliteal artery to the more distal posterior tibial artery and most atherosclerotic lesions are of the fibrous nonatheromatous type. In contrast, the presence and severity of medial calcification increases from proximal to distal

Prevalence of hyperdense paraspinal vein sign in patients with spontaneous intracranial hypotension without dural CSF leak on standard CT myelography

PURPOSE:A recently identified and treatable cause of spontaneous intracranial hypotension (SIH) is cerebrospinal fluid (CSF)-venous fistula, and a recently described computed tomography myelogram (CTM) finding highly compatible with but not diagnostic of this entity is the hyperdense paraspinal vein sign. We aimed to retrospectively measure the prevalence of the hyperdense paraspinal vein sign on CTMs in SIH patients without dural CSF leak, in comparison with control groups.METHODS:Three CTM groups were identified: 1) SIH study group, which included dural CSF leak-negative standard CTMs performed for SIH, with early and delayed imaging; 2) Early control CTMs, which were performed for indications other than SIH, with imaging shortly after intrathecal contrast administration; 3) Delayed control CTMs, which included delayed imaging. CTMs were retrospectively reviewed for the hyperdense paraspinal vein sign by experienced neuroradiologists, blinded to the group assignment. All CTMs deemed by a single reader to be positive for the hyperdense paraspinal vein sign were independently reviewed by two additional neuroradiologists; findings were considered positive only if consensus was present among all three readers. For positive cases, noncontrast CTs and prior CTMs, if available, were reviewed for the presence of the sign.RESULTS:Seven of 101 (7%) SIH patients had contrast in a spinal/paraspinal vein consistent with the hyperdense paraspinal vein sign; no patient in either control group (total n=54) demonstrated the hyperdense paraspinal vein sign (P = 0.0463). The finding occurred only at thoracic levels. Each patient had a single level of involvement. Six (86%) occurred on the right. Four occurred in female patients (57%). The sign was seen on early images in 3 of 7 cases (43%) and on both early and delayed images in 4 of 7 cases (57%). In 2 of 7 patients (29%), a noncontrast CT covering the relevant location was available and negative for the sign. A prior CTM was available in 2 of 7 patients (29%), and in both cases the hyperdense paraspinal vein sign was also evident.CONCLUSION:The prevalence of the hyperdense paraspinal vein sign in SIH patients with dural CSF leak-negative standard CTM was 7%. As the sign was not seen in control groups, this sign is highly compatible with the presence of CSF-venous fistula. Since the CTMs were not specifically dedicated to identifying hyperdense paraspinal veins (i.e., they were not dynamic and were not preceded by digital subtraction myelography), the true prevalence of the sign may be higher. Radiologists should scrutinize conventional CTMs for this sign, especially in patients in whom a traditional dural CSF leak is not identified

Predicting High-Flow Spinal CSF Leaks in Spontaneous Intracranial Hypotension Using a Spinal MRI-Based Algorithm: Have Repeat CT Myelograms Been Reduced?

ABSTRACT BACKGROUND AND PURPOSE: We adopted an imaging algorithm in 2011 in which extradural fluid on spinal MR imaging directs dynamic CT myelography. We assessed algorithm compliance and its effectiveness in reducing repeat or unnecessary dynamic CT myelograms

Kainate Receptor-Mediated Modulation of Hippocampal Fast Spiking Interneurons in a Rat Model of Schizophrenia

Kainate receptor (KAR) subunits are believed to be involved in abnormal GABAergic neurotransmission in the hippocampus (HIPP) in schizophrenia (SZ) and bipolar disorder. Postmortem studies have shown changes in the expression of the GluR5/6 subunits of KARs in the stratum oriens (SO) of sectors CA2/3, where the basolateral amygdala (BLA) sends a robust projection. Previous work using a rat model of SZ demonstrated that BLA activation leads to electrophysiological changes in fast-spiking interneurons in SO of CA2/3. The present study explores KAR modulation of interneurons in CA2/3 in response to BLA activation. Intrinsic firing properties of these interneurons through KAR-mediated activity were measured with patch-clamp recordings from rats that received 15 days of picrotoxin infusion into the BLA. Chronic BLA activation induced changes in the firing properties of CA2/3 interneurons associated with modifications in the function of KARs. Specifically, the responsiveness of these interneurons to activation of KARs was diminished in picrotoxin-treated rats, while the after-hyperpolarization (AHP) amplitude was increased. In addition, we tested blockers of KAR subunits which have been shown to have altered gene expression in SO sector CA2/3 of SZ subjects. The GluR5 antagonist UBP296 further decreased AP frequency and increased AHP amplitude in picrotoxin-treated rats. Application of the GluR6/7 antagonist NS102 suggested that activation of GluR6/7 KARs may be required to maintain the high firing rates in SO interneurons in the presence of KA. Moreover, the GluR6/7 KAR-mediated signaling may be suppressed in PICRO-treated rats. Our findings indicate that glutamatergic activity from the BLA may modulate the firing properties of CA2/3 interneurons through GluR5 and GluR6/7 KARs. These receptors are expressed in GABAergic interneurons and play a key role in the synchronization of gamma oscillations. Modulation of interneuronal activity through KARs in response to amygdala activation may lead to abnormal oscillatory rhythms reported in SZ subjects

Productivity growth, Smith effects and Ricardo effects in Euro Area's manufacturing industries

We analyse the determinants of labour productivity across (a sample of) EA member states. We focus on the divergent dynamics before and after the financial crisis, and of core countries relative to peripheral countries. We ground our empirical analysis in Paolo Sylos‐Labini's productivity equations. We test different models, including a Panel 2S‐LS model and a Panel vector autoregression model. Our preliminary findings confirm and strengthen Sylos‐Labini's main insights. Labour productivity in manufacturing industries is strongly and positively correlated with the market size (Smith effect), the relative cost of labour (Ricardo effect), the absolute cost of labour (organization effect) and past investment, whereas it is negatively correlated with current investment. Furthermore, we find evidence that the crisis has affected the size of these effects. Focusing on the core periphery dichotomy, the signs of the effects are the same for both groups of countries, although the Smith, Ricardo and long‐run investment effects are usually stronger for core countries compared to peripheral countries. The opposite holds for the organization effect, while investment effects are less clear