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Vasopressin (antidiuretic hormone) release has been thought to be controlled by interacting osmoreceptors and [Na.sup.+]-detectors for >20 years. Only recently, however, have molecular and cellular advances revealed how changes in the external concentration of [Na.sup.+] and osmolality are detected during acute and chronic osmotic perturbations. In rat vasopressin-containing neurons, local osmosensitivity is conferred by intrinsic stretch-inactivated cation channels and by taurine release from surrounding glia. [Na.sup.+] detection is accomplished by acute regulation of the permeability of stretch-inactivated channels and by changes in [Na.sup.+] channel gene expression. These features provide a first glimpse of the integrative processes at work in a central osmoregulatory reflex.

Background: NEPA, a combination antiemetic of a neurokinin‐1 (NK1) receptor antagonist (RA) (netupitant [oral]/fosnetupitant [intravenous; IV]) and 5‐HT3RA, palonosetron] offers 5‐day CINV prevention with a single dose. Fosnetupitant solution contains no allergenic excipients, surfactant, emulsifier, or solubility enhancer. A phase III study of patients receiving cisplatin found no infusion‐site or anaphylactic reactions related to IV NEPA. However, hypersensitivity reactions and anaphylaxis have been reported with other IV NK1RAs, particularly fosaprepitant in patients receiving anthracycline‐cyclophosphamide (AC)‐based chemotherapy. This study evaluated the safety and efficacy of IV NEPA in the AC setting. Materials and Methods: This phase IIIb, multinational, randomized, double‐blind study enrolled females with breast cancer naive to highly or moderately emetogenic chemotherapy. Patients were randomized to receive a single 30‐minute infusion of IV NEPA or single oral NEPA capsule on day 1 prior to AC, in repeated (up to 4) cycles. Oral dexamethasone was given to all patients on day 1 only. Results: A total of 402 patients were included. The adverse event (AE) profiles were similar for IV and oral NEPA and consistent with those expected. Most AEs were mild or moderate with a similarly low incidence of treatment‐related AEs in both groups. There were no treatment‐related injection‐site AEs and no reports of hypersensitivity or anaphylaxis. The efficacy of IV and oral NEPA were similar, with high complete response (no emesis/no rescue) rates observed in cycle 1 (overall [0–120 hours] 73.0% IV NEPA, 77.3% oral NEPA) and maintained over subsequent cycles. Conclusion: IV NEPA was highly effective and safe with no associated hypersensitivity and injection‐site reactions in patients receiving AC. Implications for Practice: As a combination of a neurokinin‐1 (NK1) receptor antagonist (RA) and 5‐HT3RA, NEPA offers 5‐day chemotherapy‐induced nausea and vomiting prevention with a single dose and an opportunity to improve adherence to antiemetic guidelines. In this randomized multinational phase IIIb study, intravenous (IV) NEPA (fosnetupitant/palonosetron) was safe and highly effective in patients receiving multiple cycles of anthracycline‐cyclophosphamide (AC)‐based chemotherapy. Unlike other IV NK1RAs, the IV NEPA combination solution does not require any surfactant, emulsifier, or solubility enhancer and contains no allergenic excipients. Hypersensitivity reactions and anaphylaxis have been reported with other IV NK1RAs, most commonly with fosaprepitant in the AC setting. Importantly, there were no injection‐site or hypersensitivity reactions associated with IV NEPA. Netupitant and palonosetron (NEPA) is a combination antiemetic that offers five‐day prevention of chemotherapy‐induced nausea and vomiting with a single dose. This article evaluates the safety and efficacy of intravenous NEPA in the setting of anthracycline/cyclophosphamide chemotherapy. [ABSTRACT FROM AUTHOR]

Background This study investigated the effects of medication overuse and withdrawal on modulation of pain processing in women with migraine. Temporal summation of laser-evoked thermal pain was used to measure the effects of conditioned pain modulation. Methods 36 female participants (12 healthy volunteers, 12 with episodic migraine and 12 with medication overuse headache) were included in a two session protocol. Medication overuse headache subjects were also tested three weeks after medication overuse headache withdrawal. Mechanical and laser-evoked thermal pain thresholds were measured on the back of the non-dominant hand where, later, temporal summation of laser-evoked thermal pain to repetitive thermal stimuli was elicited for 30 min, at an intensity producing moderate pain. Between the 10th and 20th minutes, the contralateral foot was immersed into a water bath at a not painful (30℃) or painfully cold (8℃; conditioned pain modulation) temperature. Results Episodic migraine, medication overuse headache and medication overuse headache withdrawal were associated with an increase in extracephalic temporal summation of laser-evoked thermal pain as compared to healthy volunteer subjects, while there was no alteration of laser-evoked thermal and mechanical extracephalic pain thresholds in these subjects. Conditioned pain modulation was highly efficient in temporal summation of laser-evoked thermal pain in healthy volunteer subjects, with a solid post-effect (reduction of pain). Conditioned pain modulation was still present, but reduced, in episodic migraine. By contrast, conditioned pain modulation was normal in medication overuse headache and strongly reduced in medication overuse headache withdrawal. Furthermore, in medication overuse headache withdrawal, the post-effect was no longer a decrease, but a facilitation of pain. Conclusions These data show that a decrease in conditioned pain modulation does not underlie medication overuse headache in women. On the contrary, medication overuse reinstated conditioned pain modulation in female migraine patients. They also identify different phenotypes of pain modulation in migraine patients. Registration number N° 2008-A00471-54. [ABSTRACT FROM AUTHOR]

Antiemetic therapy for chemotherapy-induced nausea and vomiting in patients with non-Hodgkin lymphoma (NHL) receiving moderately emetogenic chemotherapy (MEC) generally includes a serotonin-type 3 (5-HT3) receptor antagonist (RA). The efficacy and safety of the second-generation 5-HT3 RA, palonosetron, in patients with NHL receiving MEC was assessed. Patients received a single iv bolus injection of 0.25 mg palonosetron and chemotherapy on day 1 of the first chemotherapy cycle, and up to three further consecutive cycles. Eighty-eight patients were evaluable for efficacy and safety. The primary endpoint, the percentage of patients with a complete response in the overall phase (0-120 h after chemotherapy in each cycle), increased from 68.2% (cycle 1) to 80.5% (cycle 2), remaining high for the following cycles, and > 90% patients were emesis-free without using aprepitant during therapy. Across all cycles, 78.4% of patients experienced treatment-emergent adverse events, but only 8% related to study drug, confirming palonosetron's good safety profile (EudraCT Number: 2008-007827-14). [ABSTRACT FROM AUTHOR]

Dynamic mechanical allodynia is a widespread and intractable symptom of neuropathic pain for which there is a lack of effective therapy. We recently provided a novel perspective on the mechanisms of this symptom by showing that a simple switch in trigeminal glycine synaptic inhibition can turn touch into pain by unmasking innocuous input to superficial dorsal horn nociceptive specific neurons through a local excitatory, NMDA-dependent neural circuit involving neurons expressing the gamma isoform of protein kinase C. Here, we further investigated the clinical relevance and processing of glycine disinhibition. First, we showed that glycine disinhibition with strychnine selectively induced dynamic but not static mechanical allodynia. The induced allodynia was resistant to morphine. Second, morphine did not prevent the activation of the neural circuit underlying allodynia as shown by study of Fos expression and extracellular signal regulated kinase phosphorylation in dorsal horn neurons. Third, in contrast to intradermal capsaicin injections, light, dynamic mechanical stimuli applied under disinhibition did not produce neurokinin 1 (NK1) receptor internalization in dorsal horn neurons. Finally, light, dynamic mechanical stimuli applied under disinhibition induced Fos expression only in neurons that did not express NK1 receptor. To summarize, the selectivity and morphine resistance of the glycine-disinhibition paradigm adequately reflect the clinical characteristics of dynamic mechanical allodynia. The present findings thus reveal the involvement of a selective dorsal horn circuit in dynamic mechanical allodynia, which operates through superficial lamina nociceptive-specific neurons that do not bear NK1 receptor and provide an explanation for the differences in the pharmacological sensitivity of neuropathic pain symptoms. [ABSTRACT FROM AUTHOR]