Detection of 16 gamma-ray pulsars through blind frequency searches using the Fermi LAT

Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Direct detection of gamma-ray pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants.

Measurement of the cosmic ray e+ +e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope

Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2 m;{2} sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient electron detection strategy which provides sufficient background rejection for measurement of the steeply falling electron spectrum up to 1 TeV. Our high precision data show that the electron spectrum falls with energy as E-3.0 and does not exhibit prominent spectral features. Interpretations in terms of a conventional diffusive model as well as a potential local extra component are briefly discussed.

Analgesic requirements after major abdominal surgery are associated with OPRM1 gene polymorphism genotype and haplotype

Aims: The association between SNPs of the human OPRM1 gene encoding the µ-opioid receptor and postoperative analgesic requirements in surgical patients remains controversial. Here, we evaluate whether any of the five tag SNPs (A118G, IVS2+G691C, IVS3+G5953A, IVS3+A8449G and TAA+A2109G) representing the four linkage disequilibrium blocks of the OPRM1 gene influences postoperative analgesic requirements. Materials & methods: We studied 138 adult Japanese patients who underwent major open abdominal surgery under combined general and epidural anesthesia and received continuous postoperative epidural analgesia with opioids. Results: The 118G homozygous (GG) patients required 24-h postoperative analgesics more than 118A homozygous (AA) and heterozygous (AG) patients. Tag SNP haplotypes also were associated with 24-h postoperative analgesic requirements. Conclusions: These results suggest that OPRM1 gene tag SNP genotypes and haplotypes can primarily contribute to prediction of postoperative analgesic requirements in individual patients undergoing major open abdominal surgery.

Emergence of scale-free distribution in protein-protein interaction networks based on random selection of interacting domain pairs

Recent analyses of biological and artificial networks have revealed a common network architecture, called scale-free topology. The origin of the scale-free topology has been explained by using growth and preferential attachment mechanisms. In a cell, proteins are the most important carriers of function, and are composed of domains as elemental units responsible for the physical interaction between protein pairs. Here, we propose a model for protein-protein interaction networks that reveals the emergence of two possible topologies. We show that depending on the number of randomly selected interacting domain pairs, the connectivity distribution follows either a scale-free distribution, even in the absence of the preferential attachment, or a normal distribution. This new approach only requires an evolutionary model of proteins (nodes) but not for the interactions (edges). The edges are added by means of random interaction of domain pairs. As a result, this model offers a new mechanistic explanation for understanding complex networks with a direct biological interpretation because only protein structures and their functions evolved through genetic modifications of amino acid sequences. These findings are supported by numerical simulations as well as experimental data.

[Pharmacological classification of intractable chronic pain (drug challenge tests)]

Intractable chronic pain resists any therapy, and the mechanism of the pain varies from patient to patient even with the same disease. Therefore, patients with chronic pain tend to look for a doctor who would successfully attenuate their pain. Consequently, a patient may visit several doctors only to get similar treatments after wasting time and money. To avoid the situation, pharmacological classification (so called drug challenge test) to determine the mechanism of a patient's pain is conducted. Drugs tested are morphine, ketamine, lidocaine, thiopental, phentolamine, midazolam, ATP clomipramine, PGE1, and neurotropin. A test for each drug is conducted on a separate day. As each drug has a different pain-attenuating mechanism, mechanism of a patient's pain will be clarified when an effective drug is found. A drug is administered as a bolus several times or continuously intravenously. According to the results of our tests conducted in sixty-five patients with neuropathic pain due to peripheral nerve injuries, ketamine proves to be the most effective in alleviating pain followed by ATP, morphine and thiopental. Therapies based on the results were provided to the patients.

High doses of processed Aconiti tuber inhibit the acute but potentiate the chronic antinociception of morphine

AIM OF THE STUDY

In this study, we investigated the effects of processed Aconiti tuber (PAT), an oriental herbal medicine, at analgesic doses on acute morphine antinociception in morphine-naïve mice and morphine tolerance in morphine-tolerant mice.

MATERIALS AND METHODS

In acute experiments, mice received subcutaneous (s.c.) morphine (2, 5, or 10 mg/kg) and oral distilled water or PAT (0.3, 1.0, or 3.0 g/kg). The mechanical nociceptive threshold (MNT) and thermal nociceptive latency (TNL) were measured with the tail pressure test and tail flick test, respectively, before, and at 30, 60, 90, and 120 min after s.c. morphine injection. In chronic experiments, mice received s.c. morphine (10 mg/kg) and oral distilled water or PAT (0.3, 1.0, or 3.0 g/kg) once daily for 11 days. MNT was measured before, and at 60 min after, and TNL was measured before, and at 30 min after, daily morphine injections on days 1-11.

RESULTS

PAT at analgesic doses inhibited the acute antinociceptive effect of morphine dose-dependently in morphine-naïve mice. In contrast, PAT at analgesic doses potentiated the chronic antinociceptive effect of morphine dose-dependently by inhibiting the development of morphine tolerance dose-dependently. These effects of PAT on acute and chronic morphine antinociception were mediated through activation of kappa-opioid receptors.

CONCLUSIONS

These results indicated that chronic co-administration of PAT at analgesic doses with morphine could provide better-maintained morphine analgesia in a long-term morphine treatment after initial inhibition of acute morphine antinociception for a brief period of time.

[Selection of drugs suitable for the treatment of intractable chronic pain patients by using drug challenge tests]

Intractable chronic pain is very difficult to treat. Nowadays, small amounts of drugs, that have different actions on the mechanism of pain relief are administered intravenously, and the effects of the test drugs on individual chronic pain patients are investigated by using the evaluation method of the visual analogue scale (VAS). This will enable elucidation of the mechanisms of pain in each chronic pain patient. Based on this information, drugs that are effective for the treatment of individual chronic pain patients can be prescribed. Drugs that are used for the drug challenge tests are phentolamine, barbiturate, morphine, lidocaine, ketamine, benzodiazepine, adenosine-3-phosphate (ATP), neurotropine, and prostaglandine E1. Phentolamine is effective for the management of sympathetically maintained pain. Barbiturate and morphine are effective for the treatment of deafferentation pain and nociceptive pain, respectively. Lidocaine is effective for the treatment of neuropathic pain; ketamine, for allodynia; and benzodiazepine, for anxiety-related pain. ATP exerts a positive effect in total pain management. Neurotropine and prostaglandine E1 are effective for the management of neuropathic pain and ischemic pain, respectively. These tests aid in the selection of drugs that maybe useful for the treatment of intractable chronic pain in patients.

The comparison of effects of processed Aconiti tuber, U50488H and MK-801 on the antinociceptive tolerance to morphine

In the previous studies, we demonstrated that an oriental herbal medicine, processed Aconiti tuber (PAT), at subanalgesic doses could inhibit or reverse the antinociceptive tolerance to morphine. In the present study, we compared the effect of PAT, trans-(+/-)-3,4-dichloro-N-methyl-N-(2-(1-pyrrolidin)cyclohexyl)-benzeneacetamide methane sulfonate hydrate (U50488H), a selective kappa opioid receptor (KOR) agonist, and (-)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine-maleate (MK-801), a N-methyl-D-aspartate (NMDA) receptor antagonist, on the antinociceptive tolerance to morphine in the same experimental condition. Mice received subcutaneous morphine (10 mg/kg), and oral PAT at a subanalgesic dose (0.3 g/kg for mechanical or 1.0 g/kg for thermal test), or intraperitoneal U50488H at a subanalgesic dose (3 mg/kg), or MK-801 at a subanalgesic dose (0.1 mg/kg) once daily for 14 days. The mechanical nociceptive threshold was measured before, and at 60 min by tail pressure testing, and thermal nociceptive latency was measured before, and at 30 min by hot plate testing, after daily morphine injections. PAT and U50488H could not only inhibit the development of morphine tolerance but also reverse the already-developed morphine tolerance, while MK-801 could only inhibit the development of morphine tolerance but not reverse the already-developed morphine tolerance, in both mechanical and thermal nociceptive tests. These data suggested that PAT, an indirect-acting KOR agonist, share the common pharmacological property of KOR agonists on morphine tolerance, and that PAT may be superior to some NMDA receptor antagonists which do not reverse already-developed morphine tolerance.

Time course of systolic and diastolic blood pressure decreases during the preintubation period of anesthesia induction: modeling with a logistic function

STUDY OBJECTIVE

To investigate whether systolic (SBP) and diastolic blood pressure (DBP) decreases during the preintubation period could be expressed as 4-parameter logistic and cubic functions giving S-shaped curves.

DESIGN

Prospective, clinical study.

SETTING

Operating room of a metropolitan general hospital.

PATIENTS

Seven ASA physical status I and II patients scheduled for elective spinal surgery during general anesthesia.

INTERVENTIONS

Anesthesia was induced with fentanyl, propofol, and vecuronium injection followed by inhalation of sevoflurane.

MEASUREMENTS

The SBP and DBP data were recorded at all beats from fentanyl injection to direct laryngoscopy. The respective changes were analyzed using a logistic function: P(t) = p(L) + (q(L) - p(L))/(1 + exp{[4 m(L)/(q(L) - p(L))][k(L) - t]}) and a cubic function: P(t) = at(3) + bt(2) + ct + d, where parameter p(L) is the upper asymptote, q(L) is the lower asymptote, m(L) is the slope at the inflection point, and k(L) is the time to the inflection point and where a, b, and c are coefficients, and d are constants. Goodness of fit of the two functions was compared using a correlation coefficient and residual mean squares. Each parameter was compared with the corresponding observed data.

MAIN RESULTS

Logistic correlation coefficient values for SBP and DBP decreases were larger than the cubic correlation coefficient values (0.990 [Z transformation: 2.64 +/- 0.32] vs 0.981 [Z: 2.32 +/- 0.37] and 0.977 [Z: 2.22 +/- 0.33] vs 0.967 [Z: 2.05 +/- 0.34], respectively; P < 0.05). Logistic residual mean squares values for SBP and DBP decreases were smaller than cubic residual mean squares values (20.6 vs 41.0 and 9.2 vs 13.7 mmHg(2), respectively; P < 0.05). There were significant correlations between p(L) and SBP or DBP after anesthesia induction, between q(L) and SBP or DBP before endotracheal intubation, and between k(L) and time to maximal rate of the SBP or DBP decrease (dP/dt(min)), but no significant correlation between m(L) and dP/dt(min) for SBP or DBP.

CONCLUSIONS

Time courses of SBP and DBP decreases during the preintubation period of anesthesia induction are modeled effectively by a logistic function.

Effects of topical application of clonidine cream on pain behaviors and spinal Fos protein expression in rat models of neuropathic pain, postoperative pain, and inflammatory pain

BACKGROUND

Clonidine can effectively reduce pain and/or hypersensitivity. However, the antihypersensitivity effects of clonidine topically applied in cream (CC) have not been investigated. The authors evaluated effects of topical application of CC on pain behaviors and spinal Fos-like immunoreactivity in rats with hypersensitivity.

METHODS

Clonidine (30, 100, and 300 microg/g) was prepared in a cream base. In rat models of neuropathic pain, inflammatory pain, and postoperative pain, the authors evaluated effects of CC (0.1 g), topically applied onto the plantar surface of the injured or uninjured paw, on thermal hyperalgesia and mechanical allodynia to von Frey filaments. The authors also evaluated effects of CC on lumbar spinal Fos-like immunoreactivity.

RESULTS

In neuropathic rats, CC applied onto the injured paw reduced thermal hyperalgesia and mechanical allodynia dose dependently, whereas CC applied onto the uninjured paw had no effect. The antihypersensitivity effects of CC were antagonized by intraperitoneal yohimbine (10 mg/kg). Further, CC reduced Fos-like immunoreactivity in neuropathic rats. In contrast, CC in a single dose had no effects on hyperalgesia, allodynia, or Fos-like immunoreactivity in rats with inflammatory or postoperative pain. In rats with postoperative pain, CC repeatedly applied for 6 days reduced thermal hyperalgesia, but not mechanical allodynia, in the postoperative days, whereas it had no effects on hyperalgesia or allodynia in those with inflammatory pain.

CONCLUSIONS

Topical CC in concentrations examined significantly reduced hypersensitivity and lumbar spinal Fos-like immunoreactivity in rats with neuropathic pain, probably through activation of peripherally located alpha2 adrenoceptors. However, CC was only partially effective and totally ineffective in rats with postoperative pain and inflammatory pain, respectively.

Inhibitory effect of processed Aconiti tuber on the development of antinociceptive tolerance to morphine: evaluation with a thermal assay

In the previous studies, we demonstrated that an oriental herbal medicine processed Aconiti tuber (PAT) at subanalgesic doses could inhibit the development of mechanical antinociceptive tolerance to morphine using the tail pressure test. In the present study, we evaluated whether PAT could inhibit thermal antinociceptive tolerance to morphine using the high temperature (55 degrees C) hot plate test. Mice received subcutaneous morphine (10mg/kg), and oral PAT at doses that did not inhibit the hot plate response (0.3, 0.5, 1.0, and 2.0 g/kg), once daily for 14 days. The thermal nociceptive latency was measured at 30 min after daily morphine injections. Compared with placebo, oral PAT partially and dose-dependently inhibited the development of morphine tolerance in morphine-naïve mice, and reversed already-developed morphine tolerance in morphine-tolerant mice. These data suggested that PAT at subanalgesic doses could dose-dependently inhibit and reverse thermal antinociceptive tolerance to morphine.

[Effects of linear polarized light irradiation around the lumbar sympathetic ganglion area upon the skin temperature of lower extremities]

BACKGROUND

The effect of linear polarized light irradiation around the lumbar sympathetic ganglion area upon the skin temperature of legs may be similar to that of irradiation of near stellate ganglion area upon arms.

METHODS

Linear polarized light irradiation was induced with SUPER LIZER (Tokyo Iken, Tokyo, Japan). The C probe of SUPER LIZER was placed on the left side of the supine at the level of L2.

RESULTS

Seven-minute irradiation around the lumbar sympathetic ganglion area increased significantly the skin temperature of the irradiated side leg.

CONCLUSIONS

These results suggest that linear polarized light irradiation around the lumbar sympathetic ganglion area might be useful and beneficial for clinical application.

Pain-relieving effects of intravenous ATP in chronic intractable orofacial pain: an open-label study

PURPOSE

Chronic orofacial pain is often refractory to conventional pain therapies. We conducted an open-label study to determine whether adenosine 5'-triphosphate (ATP) could alleviate chronic intractable orofacial pain, and if so, which type of pain could respond to ATP.

METHODS

In 8 and 16 patients with non-neuropathic and neuropathic intractable orofacial pain, respectively, ATP was intravenously infused at a rate of 100 microgxkg(-1)xmin(-1) over 120 min. The magnitudes of spontaneous pain and brush-evoked allodynia were graded with a visual analog scale (VAS). When a VAS score for spontaneous pain was decreased by 50% or more by ATP, the patient was classified as a responder.

RESULTS

The patients could be clearly divided into 10 responders and 14 non-responders. Ten of the 16 patients (62.5%) with neuropathic pain, but none of the 8 patients with non-neuropathic pain, responded to ATP. In particular, all of 8 patients with neuropathic pain following pulpectomy, with or without subsequent tooth extraction, responded to ATP. In the 10 responders, VAS scores for spontaneous pain decreased slowly but progressively during the infusion period, and eventually, ATP reduced the VAS scores for spontaneous pain and allodynia by 82 +/- 15% and 74 +/- 9%, respectively. In these responders, the analgesic and anti-allodynic effects of ATP outlasted the infusion period for medians of 7 and 12 h, respectively.

CONCLUSION

Intravenous ATP did not relieve non-neuropathic orofacial pain. However, it exerted slowly expressed but long-lasting analgesic and anti-allodynic effects in patients with neuropathic orofacial pain, especially in those suffering from neuropathic pain following pulpectomy and/or tooth extraction.

Encephalopathy and rhabdomyolysis induced by iotrolan during epiduroscopy

PURPOSE

We describe a complication of epiduroscopy with encephalopathy and rhabdomyolysis associated with the contrast medium iotrolan.

CLINICAL FEATURES

A 76-yr-old man with failed back surgery syndrome underwent epiduroscopy. Sufficient lysis could not be achieved in the epidural space above the level of L4 due to dense adhesions and scar tissue. After epidural injections of iotrolan and mepivacaine, he developed motor weakness and hypoesthesia in both legs, which lasted for three hours. He also became confused, agitated, disoriented, and developed neck stiffness and tremors involving the head and legs. Computed tomography revealed diffuse contrast enhancement within the intracranial cerebrospinal fluid (CSF) spaces, indicating an intraoperative dural tear. Marked increases in serum creatinine phosphokinase and myoglobin indicated subsequent acute rhabdomyolysis. Crystalloid infusion and semi-recumbent positioning facilitated iotrolan absorption from the CSF, and the patient recovered uneventfully.

CONCLUSIONS

Dural tear during epiduroscopy may allow access of contrast media into the CSF. Neurotoxicity secondary to iotrolan within the CSF was a likely contributing factor to the encephalopathy and subsequent rhabdomyolysis. This is an instructive example of the importance of diagnosing inadvertent dural tear during epiduroscopy under iotrolan, for avoidance of adverse events such as encephalopathy and rhabdomyolysis.

Transient decreases in Bispectral Index without associated changes in the level of consciousness during photic stimulation in an epileptic patient

This case report describes a patient with a history of epileptic seizures who showed unusual decreases in the Bispectral Index (BIS) attributable to the induction of abnormal slow electroencephalographic (EEG) waves by photic stimulation, without any associated decrease in his level of consciousness. After starting anticonvulsive therapy, photic stimulation no longer induced abnormal EEG activity nor decreased BIS values. These findings suggest that BIS values may not accurately reflect a patient's actual level of consciousness in the presence of epilepsy-related abnormal EEG activity and that the BIS monitor may be able to track such EEG changes.

The Characteristics of Intravenous Adenosine-Induced Antinociception in a Rabbit Model of Acute Nociceptive Pain: A Comparative Study with Remifentanil

BACKGROUND

Adenosine and remifentanil are potent IV analgesics with ultrashort half-lives. The antinociceptive effect of IV adenosine has not been clearly characterized. We compared the antinociceptive effects of adenosine and remifentanil in rabbits.

METHODS

Sixteen rabbits, placed on a sling allowing reasonably free movement, received IV adenosine (400 microg x kg(-1) x min(-1)) or remifentanil (0.4 microg x kg(-1) x min(-1)) over 240 min.

RESULTS

Both drugs produced profound antinociception, as assessed by the number of animals unresponsive to clamping the forepaw and the electrical stimulation threshold of escape movement. With remifentanil, the antinociceptive effect increased rapidly, reaching its peak at 60 min, and then began to decline despite continued infusion. After stopping the infusion, it decreased rapidly and disappeared within 30 min. The vasodilating effect of IV adenosine was immediate in onset and ultrashort in duration. The antinociceptive effect of adenosine increased slowly but progressively during the infusion, reaching its peak only when the infusion ended. Then it decreased slowly over the following 360 min after terminating the infusion.

CONCLUSION

Remifentanil had a rapid onset and short duration of action, and probably showed signs of tolerance development, whereas the antinocieptive effect of adenosine was slow in onset and long-lasting, despite its ultrashort plasma half-life and the immediate on-off profiles of its vasodilating effect.