Lethal morphine intoxication in a patient with a sickle cell crisis and renal impairment: case report and a review of the literature

Morphine-6-glucuronide, the active metabolite of morphine, and to a lesser extent morphine itself are known to accumulate in patients with renal failure. A number of cases on non-lethal morphine toxicity in patients with renal impairment report high plasma concentrations of morphine-6-glucuronide, suggesting that this metabolite achieves sufficiently high brain concentrations to cause long-lasting respiratory depression, despite its poor central nervous system penetration. We report a lethal morphine intoxication in a 61-year-old man with sickle cell disease and renal impairment, and we measured concentrations of morphine and morphine-6-glucuronide in blood, brain and cerebrospinal fluid. There were no measurable concentrations of morphine-6-glucuronide in cerebrospinal fluid or brain tissue, despite high blood concentrations. In contrast, the relatively high morphine concentration in the brain suggests that morphine itself was responsible for the cardiorespiratory arrest in this patient. Given the fatal outcome, we recommend to avoid repeated or continuous morphine administration in renal failure.     

Pharmacokinetics of miltefosine in Old World cutaneous leishmaniasis patients

The pharmacokinetics of miltefosine in leishmaniasis patients are, to a great extent, unknown. We examined and characterized the pharmacokinetics of miltefosine in a group of patients with Old World (Leishmania major) cutaneous leishmaniasis. Miltefosine plasma concentrations were determined in samples taken during and up to 5 months after the end of treatment from 31 Dutch military personnel who contracted cutaneous leishmaniasis in Afghanistan and were treated with 150 mg miltefosine/day for 28 days. Samples were analyzed with a validated liquid chromatography-tandem mass spectrometry assay with a lower limit of quantification (LLOQ) of 4 ng/ml. Population pharmacokinetic modeling was performed with nonlinear mixed-effect modeling, using NONMEM. The pharmacokinetics of miltefosine could best be described by an open two-compartment disposition model, with a first elimination half-life of 7.05 days and a terminal elimination half-life of 30.9 days. The median concentration in the last week of treatment (days 22 to 28) was 30,800 ng/ml. The maximum duration of follow-up was 202 days after the start of treatment. All analyzed samples contained a concentration above the LLOQ. Miltefosine is eliminated from the body much slower than previously thought and is therefore still detectable in human plasma samples taken 5 to 6 months after the end of treatment. The presence of subtherapeutic miltefosine concentrations in the blood beyond 5 months after treatment might contribute to the selection of resistant parasites, and moreover, the measures for preventing the teratogenic risks of miltefosine treatment should be reconsidered.     

Rats and mice immunised with chimeric human/mouse proteinase 3 produce autoantibodies to mouse Pr3 and rat granulocytes

Aim

In this study, we employed chimeric human/mouse Proteinase 3 (PR3) proteins as tools to induce an autoantibody response to PR3 in rats and mice.

Method

Rats and mice were immunised with recombinant human PR3 (HPR3), recombinant murine PR3 (mPR3), single chimeric human/mouse PR3 (HHm, HmH, mHH, mmH, mHm, Hmm) or pools of chimeric proteins. Antibodies to mPR3 and HPR3 were measured by ELISA. Antibodies to rat PR3 were determined by indirect immunofluorescence (IIF) on rat white blood cells. Urinalysis was performed by dipstick analysis. Kidney and lung tissue was obtained for pathological examination.

Results

In mice, immunisation with the chimeric human/mouse PR3 Hmm led to an autoantibody response to mPR3. Rats immunised with the chimeric human/mouse PR3 Hmm, HmH and mmH, or a pool of the chimeric human/mouse PR3 proteins, produced antibodies selectively binding to rat granulocytes as detected by IIF. No gross pathological abnormalities could be detected in kidney or lungs of mice or rats immunised with chimeric human/mouse PR3.

Conclusion

Immunisation with chimeric human/mouse proteins induces autoantibodies to PR3 in rats and mice. Chimeric proteins can be instrumental in developing experimental models for autoimmune diseases.Wegener''s granulomatosis (WG) is associated with antineutrophil cytoplasmic antibodies (ANCA),¹ in particular to Proteinase 3 (PR3).² PR3‐ANCA are a specific and sensitive marker for WG, whereas other ANCA‐associated vasculitides are associated with antimyeloperoxidase (MPO) antibodies.³ The association between fluctuations in PR3‐ANCA and relapsing disease in WG suggests a pathogenic role for PR3‐ANCA.⁴ However, although animal models support a pathogenic role for MPO‐ANCA in vasculitis development⁵ attempts to develop an animal model for PR3‐ANCA‐associated vasculitis have not been successful thus far.⁶ Recently, chimeric Pr3 proteins that are partly composed of the human amino acid sequence and partly of the sequence of the mouse homologue have been described.⁷ In this study, we employed these chimeric proteins as immunological tools to induce an autoantibody response in rats and mice to PR3. We hypothesised that, by epitope spreading,⁸ antibodies could develop to rat or mouse PR3 leading to an autoimmune response to PR3. As the homology between rat and mouse PR3 is 94%, antibodies to mouse PR3 will likely also recognise rat PR3.⁹In a set of experiments, rats and mice were immunised with separate chimeric human/mouse PR3 proteins or combinations thereof. Indeed, rats immunised with chimeric human/mouse PR3 developed autoantibodies to mouse PR3 and rat granulocytes and mice immunised with one specific chimeric human/mouse PR3 induced antibodies to mouse PR3. The results provide the first evidence that an autoantibody response can be generated in rats and mice by immunisation with chimeric proteins.     

Exposure–Response Analysis of Osimertinib in EGFR Mutation Positive Non-Small Cell Lung Cancer Patients in a Real-Life Setting

Pharmaceutical Research - Osimertinib, an irreversible inhibitor of the epidermal growth factor receptor (EGFR) is an important drug in the treatment of EGFR-mutation positive non-small cell lung...     

Stress doses of hydrocortisone in septic shock: beneficial effects on opsonization-dependent neutrophil functions

Objective To assess the effects of stress doses of hydrocortisone (HC) on clinical parameters and neutrophil functions in patients with septic shock. Design Prospective, double-blind, randomized, placebo-controlled study. Setting Intensive care units of a university hospital. Patients and participants 30 adult patients with septic shock. Interventions Patients were allocated to receive either HC (intravenous bolus of 100 mg preceding a continuous infusion 10 mg/h, n = 15) or placebo (n = 15), respectively. The effects of HC were assessed at baseline and after 24 h. Measurements and results As compared with placebo-treated patients, administration of HC significantly decreased norepinephrine requirements (from 1.5 to 0.8 mg/h; p < 0.001), interleukin-6 serum concentrations (from 388.8 to 88.8 pg/ml; p < 0.02), and the spontaneous release of hydrogen peroxide (H₂O₂) by neutrophils (−33.0%; p < 0.05). Additionally, HC treatment preserved the autologous plasma-induced amplification of phagocytosis of zymosan particles [factor of opsonin-induced amplification of phagocytosis of unopsonized particles: 1.80 for placebo vs. 1.75 for HC at baseline (not significant between groups) and 0.50 for placebo vs. 1.75 for HC after 24 h of treatment (p < 0.05)]. These effects were paralleled by respective changes in the phagocytosis-associated H₂O₂ production. Conclusions In patients with septic shock stress doses of HC exert beneficial effects in terms of improvements in hemodynamics, decrease in pro-inflammatory mediators, and oxidative stress without the compromise of opsonization-dependent phagocytic neutrophil functions; thus, HC treatment does not aggravate non-specific immunosuppression but instead improves innate immunity in the early stage of septic shock.     

Neurons of the rat suprachiasmatic nucleus show a circadian rhythm in membrane properties that is lost during prolonged whole-cell recording

The suprachiasmatic nucleus is commonly considered to contain the main pacemaker of behavioral and hormonal circadian rhythms. Using whole-cell patch-clamp recordings, the membrane properties of suprachiasmatic nucleus neurons were investigated in order to get more insight in membrane physiological mechanisms underlying the circadian rhythm in firing activity. Circadian rhythmicity could not be detected either in spontaneous firing rate or in other membrane properties when whole-cell measurements were made following an initial phase shortly after membrane rupture. However, this apparent lack of rhythmicity was not due to an unhealthy slice preparation or to seal formation, as a clear day/night difference in firing rate was found in cell-attached recordings. Furthermore, in a subsequent series of whole-cell recordings, membrane properties were assessed directly after membrane rupture, and in this series we did find a significant day/night difference in spontaneous firing rate, input resistance and frequency adaptation. As concerns the participation of different subpopulations of suprachiasmatic nucleus neurons expressing circadian rhythmicity, cluster I neurons exhibited strong rhythmicity, whereas no day/night differences were found in cluster II neurons. Vasopressin-containing cells form a subpopulation of cluster I neurons and showed a more pronounced circadian rhythmicity than the total population of cluster I neurons. In addition to their strong rhythm in spontaneous firing rate they also displayed a day/night difference in membrane potential.