Virtual Reality Images of the Home Are Useful for Patients With Hospital-Based Palliative Care: Prospective Observational Study With Analysis by Text Mining.

Background: Malignancy patients who need long-term hospitalization can feel loneliness affecting their quality of life. The global COVID-19 pandemic has caused visiting restrictions that could mean patients who might be missing out on family support and palliative care, therefore, need to adapt and change. We used virtual reality (VR) technology with the aim of reducing feelings of loneliness among these patients. Objectives: In a small cohort setting, we aimed to clarify the usefulness of VR viewing for this purpose by text mining interviews with the patients in palliative care after their VR experience, and to clarify the feasibility of this program. Design and Setting/Subjects: Four consecutive Japanese patients in the palliative care unit viewed personalized familiar persons or places through VR goggles, while communicating by telephone. After the VR experience, text mining of the patients' interviews was used to extract the words for the frequency count and co-occurrence analysis. Results: Four clusters were extracted: "relief from the pain of hospitalization by feeling safe and secure with family members nearby," "using VR to regain daily life," "immersive feeling of being in the same space as family," and "loneliness due to the realistic feeling of separation from the family through VR experience." There were no cases of VR sickness. Conclusion: Our results attained by text mining suggest the promising potential of VR imaging of familiar surroundings for patients in palliative care.

Role of dopamine D2 and D3 receptors in mediating the U-50,488H discriminative cue: comparison with methamphetamine and cocaine.

Substitutions of the dopamine D(2) or D(3) receptor agonists for the discriminative stimulus effect induced by U-50,488H, methamphetamine (METH) and cocaine in rats were examined. The D(2) receptor agonist R-propylnorapomorphine [(-)-NPA] failed to substitute for U-50,488H cue, while the D(3) receptor-preferred agonist (+/-)-7-hydroxy-dipropylaminotetralin hydrobromide (7-OH-DPAT) produced dose-related increases in drug-appropriate responding up to 0.03 mg/kg, which fully substituted. At doses greater than 0.03 mg/kg of 7-OH-DPAT, there was a dose-dependent decrease in the percentage of responses on the U-50,488H-appropriate lever. Furthermore (-)-NPA and 7-OH-DPAT at high doses substituted for the discriminative stimulus effect induced by both METH and cocaine, indicating that 7-OH-DPAT at high doses may interact with D(2) receptors. These results suggest that the stimulation of D(2) receptor may be critical for the production of the discriminative stimulus effect induced by METH and cocaine, whereas the stimulation of D(3) receptor may contribute to the production of the U-50,488H cue.

Sigma-1 receptor function is critical for both the discriminative stimulus and aversive effects of the kappa-opioid receptor agonist U-50488H.

The present study was undertaken to identify possible similarities between the effects of kappa-opioid receptor agonist, N-methyl-D-aspartate-receptor antagonist, and sigma receptor agonist on the discriminative stimulus effects of U-50488H, and the possible involvement of sigma receptors in the discriminative stimulus and aversive effects of U-50488H. The kappa-opioid receptor agonist U-50488H produced significant place aversion as measured by the conditioned place preference procedure, and this effect was completely abolished by treatment with the putative sigma-1 receptor antagonist NE-100. In addition, phencyclidine (+)-SKF-10047 and (+)-pentazocine, which are sigma receptor agonists, generalized to the discriminative stimulus effects of U-50488H in rats that had been trained to discriminate between U-50488H (3.0 mg/kg) and saline. Furthermore, NE-100 significantly attenuated the discriminative stimulus effects of U-50488H and the U-50488H-like discriminative stimulus effects of phencyclidine. These results suggest that the sigma-1 receptor is responsible for both the discriminative stimulus effects and aversive effects of U-50488H.

Upregulation of bradykinin receptors is implicated in the pain associated with caerulein-induced acute pancreatitis.

Although the way for pain management associated with acute pancreatitis has been searched for, there are not enough medications available for it. The aim of the present study was to investigate the role of bradykinin (BK) in pain related to acute pancreatitis. After repeated injections of caerulein (50 µg/kg and 6 times), mice showed edema in the pancreas, and blood concentrations of pancreatic enzymes (amylase and lipase) were clearly elevated. A histopathological study demonstrated that caerulein caused tissue damage characterized by edema, acinar cell necrosis, interstitial hemorrhage, and inflammatory cell infiltrates. Furthermore, the mRNA levels of interleukin-1ß and monocyte chemotactic protein (MCP)-1 were significantly increased in the pancreas of caerulein-treated mice. The sensitivity of abdominal organs as measured by abdominal balloon distension was enhanced in caerulein-injected mice, suggesting that caerulein caused pancreatic hyperalgesia. Moreover, repeated treatment with caerulein resulted in cutaneous tactile allodynia of the upper abdominal region as demonstrated by the use of von Frey filaments, indicating that caerulein-treated mice exhibited referred pain. Under this condition, the mRNA levels of bradykinin B1 receptor (BKB1R) and bradykinin B2 receptor (BKB2R) were significantly increased in the dorsal root ganglion (DRG). Finally, we found that des-Arg9-(Leu8)-bradykinin (BKB1R antagonist) and HOE-140 (BKB2R antagonist) attenuated the acute pancreatitis pain-like state in caerulein-treated mice. These findings suggest that the upregulation of BK receptors in the DRG may, at least in part, contribute to the development of the acute pancreatitis pain-like state in mice.

Effects of gabapentin on brain hyperactivity related to pain and sleep disturbance under a neuropathic pain-like state using fMRI and brain wave analysis.

Neuropathic pain is the most difficult pain to manage in the pain clinic, and sleep problems are common among patients with chronic pain including neuropathic pain. In the present study, we tried to visualize the intensity of pain by assessing neuronal activity and investigated sleep disturbance under a neuropathic pain-like state in mice using functional magnetic resonance imaging (fMRI) and electroencephalogram (EEG)/electromyogram (EMG), respectively. Furthermore, we investigated the effect of gabapentin (GBP) on these phenomena. In a model of neuropathic pain, sciatic nerve ligation caused a marked decrease in the latency of paw withdrawal in response to a thermal stimulus only on the ipsilateral side. Under this condition, fMRI showed that sciatic nerve ligation produced a significant increase in the blood oxygenation level-dependent (BOLD) signal intensity in the pain matrix, which was significantly decreased 2 h after the i.p. injection of GBP. Based on the results of an EEG/EMG analysis, sciatic nerve-ligated animals showed a statistically significant increase in wakefulness and a decrease in non-rapid eye movement (NREM) sleep during the light phase, and the sleep disturbance was almost completely alleviated by a higher dose of GBP in nerve-ligated mice. These findings suggest that neuropathic pain associated with sleep disturbance can be objectively assessed by fMRI and EEG/EMG analysis in animal models. Furthermore, GBP may improve the quality of sleep as well as control pain in patients with neuropathic pain.

Sleep disturbances in a neuropathic pain-like condition in the mouse are associated with altered GABAergic transmission in the cingulate cortex.

Insomnia is a common problem for people with chronic pain. Cortical GABAergic neurons are part of the neurobiological substrate that underlies homeostatic sleep regulation. In the present study, we confirmed that sciatic nerve ligation caused thermal hyperalgesia and tactile allodynia in mice. In this experimental model for neuropathic pain, we found an increase in wakefulness and a decrease in non-rapid eye movement sleep under a neuropathic pain-like state. Under these conditions, membrane-bound GABA (γ-aminobutyric acid) transporters (GATs) on activated glial fibrillary acidic protein-positive astrocytes were significantly increased in the cingulate cortex, and extracellular GABA levels in this area after depolarization were rapidly decreased by nerve injury. Furthermore, sleep disturbance induced by sciatic nerve ligation was improved by the intracingulate cortex injection of a GAT-3 inhibitor. These findings provide novel evidence that sciatic nerve ligation decreases extracellular-released GABA in the cingulate cortex of mice. These phenomena may, at least in part, explain the insomnia in patients with neuropathic pain. Neuropathic pain-like stimuli suppress the GABAergic transmission with increased GABA (γ-aminobutyric acid) transporters located on activated astrocytes in the cingulate cortex related to sleep disturbance.

Effects of halothane and isoflurane on acetylcholine-induced, endothelium-dependent vasodilation in perfused rat mesenteric arterial beds.

PURPOSE: The present study was designed to examine the effects of halothane and isoflurane on acetylcholine-induced, endothelium-dependent vasodilation in rat mesenteric arterial beds perfused at a constant flow both in vitro and in situ. METHODS: In the in-vitro preparation, the mesenteric artery was cannulated and perfused (5 ml x min(-1)). The perfusion pressure was continuously monitored. Under active tone induced by methoxamine, the effects of halothane and isoflurane on the vasodilator response to acetylcholine in either the presence or absence of NG-nitro-L-arginine (L-NA), tetraethylammonium (TEA), or KCl (30 mM)-depolarization were examined. All experiments in these preparations were performed in the presence of indomethacin (10 mM). In the in-situ experimental model, rats were anesthetized with pentobarbital and the lungs were mechanically ventilated via a tracheostomy with a ventilator. The superior mesenteric artery was cannulated and used for the monitoring of the perfusion pressure. Blood shunting with constant flow (2 ml x min(-1)) from the carotid artery to the superior mesenteric artery was introduced with clamping at the immediately distal portion of the mesenteric artery branching. Following 20-min ventilation with halothane or isoflurane at 1 minimum alveolar concentration (MAC) in oxygen, acetylcholine was given from the mesenteric artery, under active tone induced by norepinephrine (100 mg x kg(-1) x hr(-1)). RESULTS: In the in-vitro preparation, the nitric oxide synthase inhibitor, L-NA (100 microM) did not affect vasodilations to acetylcholine (1, 10 nM), while the K+ channel inhibitor TEA (10 mM), as well as KCl (30 mM), significantly reduced these vasodilations. However, only in the presence of L-NA, TEA and KCl completely abolished the vasodilations produced by acetylcholine. The higher concentrations of halothane (2.0%, 3.0%), but neither isoflurane (3.0%) nor the lower concentration of halothane (1.0%), significantly impaired vasodilator responses to acetylcholine in the presence of L-NA, whereas the volatile anesthetics did not affect these vasodilations in the absence of L-NA. Halothane (2.0%) did not alter the vasodilation produced by acetylcholine in the presence of TEA or KCl. In the in-vivo preparation, the vasodilator effects of acetylcholine (1 and 10 nmol) were not affected by the inhalation of halothane (1.0%) or isoflurane (1.3%). CONCLUSION: These results suggest that, in resistance arteries in conditions of constant flow, halothane and isoflurane do not affect vasodilations in response to an endothelium-dependent agonist. However, in these preparations, once the enzymatic activity of nitric oxide synthase is inhibited, higher concentrations of halothane, but neither isoflurane nor the lower concentration of halothane, appear to impair endothelium-dependent relaxations, probably mediated by TEA-sensitive K+ channels.