Improved method for analysis of cysteinyldopa in human serum

5‐S‐l‐Cysteinyl‐l‐dopa is a well‐known pigment intermediate and analysis of its serum concentration is well suited for evaluation of treatment and follow‐up of stage III and IV malignant melanoma. A simplified analytical method is described using organic extraction followed by clean‐up on a boronate gel to capture the compound containing vicinal hydroxyls. Weak acid solution elutes the 5‐S‐cysteinyldopa suitable for high‐performance liquid chromatography (HPLC). The absolute recoveries of cysteinyldopa and its diastereomer 5‐S‐D‐cysteinyl‐l‐dopa (used as an internal standard) were 81.5±2.8% and 81.3±2.7%, respectively, and use of the internal standard for the whole procedure gave an analytical recovery of 101±0.8%. The limit of quantitation was 1.5?nmol/L and the imprecision of the method was <5.0% over the analytical range 1.5–500?nmol/L. The method is cheap and easy to perform and compares well with other described techniques. The use of the method is illustrated by results obtained during treatment of a patient with metastatic malignant melanoma.     

Involvement of AMPA Receptors in CSD‐Induced Impairment of LTP in the Hippocampus

Objective.— To investigate the alteration of hippocampal long‐term plasticity and basal synaptic transmission induced by repetitive cortical spreading depressions (CSDs). Background.— There is a relationship between migraine aura and amnesia attack. CSD, a state underlying migraine attacks, may be responsible for hippocampus‐related symptoms. However, the precise role of CSD on hippocampal activity has not been investigated. Methods.— Male Wistar rats were divided into CSD and control groups. Repetitive CSDs were induced in vivo by topical application of solid KCl. Forty‐five minutes later, the ipsilateral hippocampus was removed, and hippocampal slices were prepared for a series of electrophysiological studies. Results.— Repetitive CSDs led to a decrease in the magnitude of long‐term potentiation in the hippocampus. CSD also reduced hippocampal synaptic efficacy, as shown by a reduction in post‐synaptic α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor responses. In contrast, the post‐synaptic N‐methyl‐d ‐aspartate receptor responses remained unchanged. In addition, there were no changes in paired‐pulse profiles between the groups, indicating that CSD did not induce any presynaptic alterations. Conclusion.— These findings suggest that a reduction of post‐synaptic α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor responses is the mechanism responsible for impaired hippocampal long‐term potentiation induced by CSD.     

Activation of PAR‐2 Elicits NO‐Dependent and CGRP‐Independent Dilation of the Dural Artery

(Headache 2010;50:1017‐1030) Objectives.— The goal of this study was to determine the vascular effects of protease‐activated receptor‐2 (PAR‐2) activation in the rat cranial vasculature. Background.— The role of PAR‐2 in pain and inflammatory conditions has been established but the information available on its effects and receptor distribution in the trigeminal vascular axis is limited. We studied the dilatory function and expression of PAR‐2 in the neuro‐vascular circuit, critical in migraine pathogenesis. We also investigated the interaction of PAR‐2 with calcitonin gene‐related peptide (CGRP) and dural mast cells. Methods.— We used an improved model of intravital microscopy on the closed cranial window in rats to study the vascular effects of PAR‐2 activating peptides (PAR‐2 APs; SLIGRL‐NH₂, 2‐Furoyl‐LIGRLO‐NH₂) in the dural vasculature. Measurement of immunoreactive CGRP in skull halves and in trigeminal nucleus caudalis was done by using an enzyme‐linked immunosorbent assay. We also analyzed the presence of PAR‐2 in different migraine relevant tissues by quantitative real‐time PCR and Western blot analysis. Results.— PAR‐2 APs and trypsin induced a dose‐dependent increase in dural artery diameter. The topical application of a nonspecific nitric oxide synthase (NOS) inhibitor, L‐N^G‐Nitroarginine methyl ester, attenuated SLIGRL‐NH₂ responses. Olcegepant, a CGRP receptor antagonist, did not a have significant effect on the SLIGRL‐NH₂ responses, though exogenous CGRP responses were completely blocked. There was no significant release of CGRP from skull halves incubated with SLIGRL‐NH₂ as compared with those incubated with the corresponding negative peptide. Chronic mast cell degranulation did not change the vascular effects of PAR‐2 APs. mRNA and protein expression of PAR‐2 were found throughout trigeminovasuclar axis. Conclusion.— PAR‐2 activation leads to vasodilation of dural arteries and these responses are partially mediated by nitric oxide. As PAR‐2 is present throughout trigeminovasuclar axis, it may have a role in migraine pathogenesis, independent of CGRP and mast cell mediated mechanism.     

The recent outbreaks of human coronaviruses: A medicinal chemistry perspective

Coronaviruses (CoVs) infect both humans and animals. In humans, CoVs can cause respiratory, kidney, heart, brain, and intestinal infections that can range from mild to lethal. Since the start of the 21st century, three β‐coronaviruses have crossed the species barrier to infect humans: severe‐acute respiratory syndrome (SARS)‐CoV‐1, Middle East respiratory syndrome (MERS)‐CoV, and SARS‐CoV‐2 (2019‐nCoV). These viruses are dangerous and can easily be transmitted from human to human. Therefore, the development of anticoronaviral therapies is urgently needed. However, to date, no approved vaccines or drugs against CoV infections are available. In this review, we focus on the medicinal chemistry efforts toward the development of antiviral agents against SARS‐CoV‐1, MERS‐CoV, SARS‐CoV‐2, targeting biochemical events important for viral replication and its life cycle. These targets include the spike glycoprotein and its host‐receptors for viral entry, proteases that are essential for cleaving polyproteins to produce functional proteins, and RNA‐dependent RNA polymerase for viral RNA replication.     

In vitro inhibitory effects of Wen-pi-tang-Hab-Wu-ling-san on human cytochrome P450 isoforms

What is known and Objective: Although Wen‐pi‐tang‐Hab‐Wu‐ling‐san (WHW), an oriental herbal medicine, has been prescribed for the treatment of chronic renal failure (CRF) in Korean clinics, no studies regarding WHW–drug interactions had been reported. The purpose of this study was to evaluate the possibility that WHW inhibits the catalytic activities of major cytochrome P450 (CYP) isoforms. Methods: The abilities of various WHW extracts to inhibit phenacetin O‐de‐ethylation (CYP1A2), tolbutamide 4‐methylhydroxylation (CYP2C9), omeprazole 4′‐hydroxylation (CYP2C19), dextromethorphan O‐demethylation (CYP2D6), chlorzoxazone 6‐hydroxylation (CYP2E1) and midazolam 1‐hydroxylation (CYP3A4) were assessed using human liver microsomes. Results and Discussion: WHW extract at concentrations up to 100 μm showed negligible inhibition of the six CYP isoforms tested (CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4), with apparent IC₅₀ values (concentration of the inhibitor causing 50% inhibition of the original enzyme activity) of 817.5, 601.6, 521.7, 310.2, 342.8 and 487.0 μg/mL, respectively. What is new and Conclusion: Our in vitro findings suggest that WHW extract at concentrations corresponding to a clinically recommended dosage range has no notable inhibitory effects on CYP isoforms. Therefore, we believe that WHW extract may be free of drug–herb interactions when co‐administered with other medicines. However, in vivo human studies are needed to confirm these results.     

Outcome of patients hospitalized for COVID‐19 and exposure to angiotensin‐converting enzyme inhibitors and angiotensin‐receptor blockers in France: results of the ACE‐CoV study

Data are lacking on the impact of ACEI/ARB exposure on unfavorable outcome in the population of patients hospitalized for COVID‐19 with hypertension/cardiovascular disease, particularly in Europe. The ACE‐CoV study was designed to assess this question. The study was conducted in the Covid‐Clinic‐Toul cohort, which contains data about all patients hospitalized at Toulouse University hospital, France with a SARS‐CoV‐2 infection since March, 2020. We selected the patients with a history of cardiovascular disease (heart failure or coronary disease) and/or arterial hypertension. We conducted a subgroup analysis in patients with arterial hypertension. ACEI/ARB exposures at admission were assessed. The outcome was composite: admission to intensive care unit, need of mechanical ventilation or death during the 14 days after admission to hospital. We used logistic regression models with propensity scores (PS) weighted by overlap weighting (OW) and inverse probability of treatment weighting (IPTW). Between March 2020 and April 20, 2020, the Covid‐Clinic‐Toul included 263 patients. Among them, 111 were included in the ACE‐CoV study population. In OW‐PS‐adjusted analyses, the association of exposure to ACEIs or ARBs with outcome occurrence was OR: 1.56 (95% CI: 0.73–3.33). It was 0.99 (95% CI: 0.68–1.45) for ACEIs and 1.64 (95% CI: 0.77–3.50) for ARBs. Analyses with weighting by the IPTW‐PS method gave similar results. Results were similar when considering the subgroup of patients with arterial hypertension. The ACE‐CoV study found no association between exposure to ACEIs or ARBs and unfavorable outcome in hospitalized patients for COVID‐19 with a history of cardiovascular disease/arterial hypertension.     

Efficacy of moxifloxacin for treatment of penicillin-, macrolide- and multidrug-resistant Streptococcus pneumoniae in community-acquired pneumonia

This pooled analysis of six prospective, multicentre trials aimed to determine the efficacy of moxifloxacin in community-acquired pneumonia (CAP) due to penicillin-, macrolide- and multidrug-resistant Streptococcus pneumoniae (MDRSP). At a central laboratory, isolates were identified and antimicrobial susceptibility determined (microbroth dilution). MDRSP was defined as resistance > or =3 drug classes. Patients received oral or sequential intravenous/oral 400 mg moxifloxacin once daily for 7-14 days. The primary endpoint was clinical success at test-of-cure for efficacy-valid patients with proven pretherapy S. pneumoniae infection. Of 140 S. pneumoniae isolated (112 respiratory, 28 blood), 23 (16.4%) were penicillin resistant, 26 (18.6%) macrolide resistant and 31 (22.1%) MDRSP. The moxifloxacin MIC90 was 0.25 microg/ml. Clinical cure with moxifloxacin was 95.4% (125/131) overall, and 100% (21/21) for penicillin-, 95.7% (22/23) for macrolide- and 96.4% (27/28) for multidrug-resistant strains. Moxifloxacin provided excellent clinical and bacteriological cure rates in CAP due to drug-resistant pneumococci.     

Adjunct therapeutic plasma exchange for anti-N-methyl-D-aspartate receptor antibody encephalitis: a case report and review of literature

Encephalitis associated with autoantibodies directed against the N-methyl-D-aspartate receptor (NMDAR) is usually a paraneoplastic syndrome that presents in young females with ovarian teratomas. We report a case of a previously healthy 14-year-old girl with sudden-onset paranoia, hallucinations, hyperactivity, increased speech, decreased sleep, seizures, and violent behavior deteriorating to catatonia. Her cerebrospinal fluid tested positive for anti-NMDAR antibodies. She was treated with five sessions of therapeutic plasma exchange (TPE) after having failed therapy with antibiotics, intravenous steroids, intravenous immunoglobulin (IVIG), one dose of rituximab, and seven sessions of electroconvulsive therapy (ECT). The American Society for Apheresis assigns a Category III (Grade 2C) recommendation for TPE in paraneoplastic neurologic syndromes; however, apheresis specifically for anti-NMDAR encephalitis has not been well studied. Literature review revealed two case reports describing outstanding improvement in patients with anti-NMDAR encephalitis following TPE. We report no improvement in our patient's symptoms after plasma exchange and discuss possible reasons for why it failed along with review of the literature.     

Memantine for the treatment of general neuropathic pain: a narrative review

Neuropathic pain (NP) is difficult to treat and is associated with a decline in quality of life. NP aetiologies are numerous and a number of pathologies display neuropathic characteristics. Of the various N‐methyl‐d ‐aspartate antagonists that are alternatives to be recommended in first‐line NP treatment, memantine has the safest side‐effect profile and has long been approved in Alzheimer's disease. The review covers memantine studies in postherpetic neuralgia, diabetic pain, postoperative pain, complex regional pain syndrome, chronic phantom limb pain, opioid‐refractory pain and fibromyalgia. Results were inconclusive because of studies with poor levels of evidence, paucity of trials and small samples. Two recent randomized trials, however, showed significant efficacy of memantine: one demonstrated prophylactic effects against postoperative neuralgia and pain‐associated psychological impairment; in the other, memantine improved pain and cognition in fibromyalgia. Both studies found no side effects or adverse events. Given the high rate of therapeutic failure in chronic states, often because of adverse events, the excellent benefit/risk ratio of memantine in these pilot studies encourages further exploration of this drug in NP prevention and in fibromyalgia in larger‐scale studies.