Thrombotic thrombocytopenic purpura associated to dual checkpoint inhibitor therapy for metastatic melanoma.

Dual checkpoint inhibitor therapy has known immune-related adverse events. However, checkpoint inhibitor-associated thrombotic thrombocytopenic purpura is very rarely reported. We present a case of a 70-year old man with advanced melanoma, presenting with severe thrombocytopenia, hemolytic anemia with schistocytes and suppressed ADAMTS-13 activity by ADAMTS-13 inhibitors. We discuss differential diagnoses and speculated mechanisms of this obviously therapy-related adverse event, which should be considered by clinicians prescribing these drugs.

Relevant pericardial effusion caused by cytomegalovirus infection in an immunocompetent patient: a case report.

BACKGROUND: Cytomegalovirus infection is known to cause symptomatic disease in immunocompromised patients, while an infection in immunocompetent individuals normally causes few or no symptoms. We present the case of an immunocompetent adult patient with unexpected severe evolution. CASE PRESENTATION: An otherwise healthy, 72-year-old Caucasian woman presented with complaints of progressive shoulder pain and dyspnoea on exertion. The blood test results showed elevated inflammation parameters and elevated hepatic transaminase levels. Radiologic examinations were carried out, and the computed tomography scan revealed a hepatomegaly and a chest X-ray showed evidence of a unilateral pleural effusion. A transthoracic echocardiography detected pericardial effusion with consecutive hemodynamic changes. Since it was considered that using ultrasound-guided pericardiocentesis could significantly increase the risk of liver injury due to hepatomegaly, a pericardial window was performed instead. Further investigation showed that our patient tested positive for an acute cytomegalovirus infection in the serologic tests. Laboratory findings included new evidence of immunoglobulin M seroconversion and high immunoglobulin G avidity, so we considered the possibility that a former cytomegalovirus infection may be coexisting with a new cytomegalovirus reinfection. CONCLUSIONS: In immunocompetent individuals, a symptomatic cytomegalovirus primary infection or reinfection should be considered in patients presenting with pericardial effusion and serositis.

Neuroprotection with the P53-Inhibitor Pifithrin-µ after Cardiac Arrest in a Rodent Model.

BACKGROUND: The small molecule pifithrin-µ reversibility inhibits the mitochondrial pathway of apoptosis. The neuronal effects of pifithrin-µ applied after cardiac arrest are unknown. We hypothesized that pifithrin-µ reduces neuronal damage in the most vulnerable brain region, the hippocampus, after cardiac arrest. METHODS: In two randomized controlled series we administered pifithrin-µ or control in 109 rats resuscitated after 8 or 10 min of cardiac arrest. Neuronal damage was blindly assessed with histology (Fluoro Jade B: FJB, cresyl violet: CV) in the most vulnerable brain region (CA1 segment of hippocampus) and with a series of neurobehavioral tests (Open Field Task, Tape-Removal Test, Morris Water Maze test). Mixed ANOVA was used to combine both series, simple comparisons were done with t tests or Mann-Whitney U test. RESULTS: Pifithrin-µ reduced the number of degenerating, FJB-positive neurons by 25% (mixed ANOVA p group = 0.014). This was more prominent after 8 min cardiac arrest (8 min arrest pifithrin-µ 94 ±â€Š47 vs control 128 ±â€Š37; n = 11 each; 10 min arrest pifithrin-µ 78 ±â€Š44, n = 15 vs control 101 ±â€Š31, n = 18; p group* arrest length interaction = 0.622). The reduction of ischemic CV-positive neurons in pifithrin-µ animals was not significant (ANOVA p group = 0.063). No significant group differences were found in neurobehavioral testing. CONCLUSION: Temporarily inhibition of apoptosis with pifithrin-µ after cardiac arrest decreases the number of injured neurons in the CA1 segment of hippocampus in a cardiac arrest rat model, without clinical correlate. Further studies should elucidate the role of this neuroprotective agent in different settings and with longer cardiac arrest.

Massive Arteriovenous Malformation with Stroke-Like Presentation.

We report of a 75-year-old patient with stroke-like presentation, where cerebral imaging led to the diagnosis of a massive arteriovenous malformation (AVM) of the whole left hemisphere. We suggest considering AVM as a differential diagnosis in patients with symptoms of acute stroke despite age and, in the absence of contraindications, in this setting to obtain MRI or CT angiography of the brain.

A randomized trial of the effects of the noble gases helium and argon on neuroprotection in a rodent cardiac arrest model.

BACKGROUND: The noble gas xenon is considered as a neuroprotective agent, but availability of the gas is limited. Studies on neuroprotection with the abundant noble gases helium and argon demonstrated mixed results, and data regarding neuroprotection after cardiac arrest are scant. We tested the hypothesis that administration of 50% helium or 50% argon for 24 h after resuscitation from cardiac arrest improves clinical and histological outcome in our 8 min rat cardiac arrest model. METHODS: Forty animals had cardiac arrest induced with intravenous potassium/esmolol and were randomized to post-resuscitation ventilation with either helium/oxygen, argon/oxygen or air/oxygen for 24 h. Eight additional animals without cardiac arrest served as reference, these animals were not randomized and not included into the statistical analysis. Primary outcome was assessment of neuronal damage in histology of the region I of hippocampus proper (CA1) from those animals surviving until day 5. Secondary outcome was evaluation of neurobehavior by daily testing of a Neurodeficit Score (NDS), the Tape Removal Test (TRT), a simple vertical pole test (VPT) and the Open Field Test (OFT). Because of the non-parametric distribution of the data, the histological assessments were compared with the Kruskal-Wallis test. Treatment effect in repeated measured assessments was estimated with a linear regression with clustered robust standard errors (SE), where normality is less important. RESULTS: Twenty-nine out of 40 rats survived until day 5 with significant initial deficits in neurobehavioral, but rapid improvement within all groups randomized to cardiac arrest. There were no statistical significant differences between groups neither in the histological nor in neurobehavioral assessment. CONCLUSIONS: The replacement of air with either helium or argon in a 50:50 air/oxygen mixture for 24 h did not improve histological or clinical outcome in rats subjected to 8 min of cardiac arrest.

An improved simple rat model for global cerebral ischaemia by induced cardiac arrest.

OBJECTIVES: Cerebral hypoxic-ischaemic injury following cardiac arrest is a devastating disease affecting thousands of patients each year. There is a complex interaction between post-resuscitation injury after whole-body ischaemia-reperfusion and cerebral damage which cannot be explored in in vitro systems only; there is a need for animal models. In this study, we describe and evaluate the feasibility and efficiency of our simple rodent cardiac arrest model. > METHODS: Ten wistar rats were subjected to 9 and 10 minutes of cardiac arrest. Cardiac arrest was introduced with a mixture of the short-acting beta-blocking drug esmolol and potassium chloride. RESULTS: All animals could be resuscitated within 1 minute, and survived until day 5. General health score and neurobehavioural testing indicated substantial impairment after cardiac arrest, without differences between groups. Histological examination of the hippocampus CA1 segment, the most vulnerable segment of the cerebrum, demonstrated extensive damage in the cresyl violet staining, as well as in the Fluoro-Jade B staining and in the Iba-1 staining, indicating recruitment of microglia after the hypoxic-ischaemic event. Again, there were no differences between the 9- and 10-minute cardiac arrest groups. DISCUSSION: We were able to establish a simple and reproducible 9- and 10-minute rodent cardiac arrest model with a well-defined no-flow-time. Extensive damage can be found in the hippocampus CA1 segment. The lack of difference between 9- and 10-minute cardiac arrest time in the neuropsychological, the open field test and the histological evaluations is mainly due to the small sample size.

Do different anesthesia regimes affect hippocampal apoptosis and neurologic deficits in a rodent cardiac arrest model?

BACKGROUND: Different anesthesia regimes are commonly used in experimental models of cardiac arrest, but the effects of various anesthetics on clinical outcome parameters are unknown. We conducted a study in which we subjected rats to cardiac arrest under medetomidine/ketamine or sevoflurane/fentanyl anesthesia. METHODS: Asystolic cardiac arrest for 8 minutes was induced in 73 rats with a mixture of potassium chloride and esmolol. Daily behavioral and neurological examination included the open field test (OFT), the tape removal test (TRT) and a neurodeficit score (NDS). Animals were randomized for sacrifice on day 2 or day 5 and brains were harvested for histology in the hippocampus cornus ammonis segment CA1. The inflammatory markers IL-6, TNF-α, MCP-1 and MIP-1α were assessed in cerebrospinal fluid (CSF). Proportions of survival were tested with the Fisher's exact test, repeated measurements were assessed with the Friedman's test; the baseline values were tested using Mann-Whitney U test and the difference of results of repeated measures were compared. RESULTS: In 31 animals that survived beyond 24 hours neither OFT, TRT nor NDS differed between the groups; histology was similar on day 2. On day 5, significantly more apoptosis in the CA1 segment of the hippocampus was found in the sevoflurane/fentanyl group. MCP-1 was higher on day 5 in the sevoflurane/fentanyl group (p = 0.04). All other cyto- and chemokines were below detection threshold. CONCLUSION: In our cardiac arrest model neurological function was not influenced by different anesthetic regimes; in contrast, anesthesia with sevoflurane/fentanyl results in increased CSF inflammation and histologic damage at day 5 post cardiac arrest.