COVID19 infection in a patient with paroxysmal nocturnal hemoglobinuria: A case report

Introduction:Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired, life-threatening hemopoietic stem cell disorder characterized by the triad of hemolytic anemia, thrombosis, and impaired bone marrow function. Evidence suggests that severe outcomes in COVID19 infection are attributed to the excessive activation of the complement cascade leading to acute lung injury and associated is with an increased prothrombotic state.Patient concerns:A 27-year-old Caucasian man with PNH presented to the Emergency Department of our hospital with acute onset shortness of breath, cough and blood in urine.Diagnosis:The patient was diagnosed with acute hemolytic exacerbation of PNH complicated with moderate COVID19 pneumonia.Outcomes:The patient was initiated with an anticoagulant unfractionated heparin, dexamethasone, and cefuroxime injection. His symptoms quickly resolved, and he was discharged after 5 days.Conclusion:The complement system activation is a critical component in the sequalae of COVID19 infection. Evidence suggests that severe outcomes in COVID19 infection are attributed to the excessive activation of the complement cascade leading to acute lung injury and associated is with an increased prothrombotic state. Notably, C5a concentration was noted to be higher in patients with COVID19 infection. The use of complement inhibitors to attenuate immune mediated damage in COVID19 nevertheless represents a very interesting theoretical approach. However, careful consideration as to which patients may benefit will be required and the outcome of clinical trials needed.     

Admixed phenotype of NEDD4L associated periventricular nodular heterotopia: A case report

Rationale:Periventricular nodular heterotopia-7 (PVNH7) is a neurodevelopmental disorder associated with improper neuronal migration during neurogenesis in cortex development caused by pathogenic variants in the NEDD4L gene.Patient concerns:We report the case of a polystigmatized 2-year-old boy having significant symptomatologic overlap with PVNH7, such as delayed psychomotor and mental development, seizures and infantile spasms, periventricular nodular heterotopia, polymicrogyria, cleft palate, 2 to 3 toe syndactyly, hypotonia, microretrognathia, strabismus, and absent speech and walking. The patient showed also distinct symptoms falling outside PVNH7 symptomatology, also present in the proband''s older brother, such as blue sclerae, hydronephrosis, transversal palmar crease (found also in their father), and bilateral talipes equinovarus. In addition, the patient suffered from many other symptoms.Diagnoses:The boy, his brother and their parents were subjected to whole-exome sequencing. Because of uncertainties in symptomatology and inheritance pattern, the top-down approach was hard to apply. Using the bottom-up approach, we identified a known pathogenic variant, NM_001144967.2(NEDD4L):c.2677G>A:p.Glu893Lys, in the proband''s genome that absented in any other analyzed family member, suggesting its de novo origin.Interventions and outcomes:The patient was treated with Convulex 300 mg/mL for the successful seizure control and Euthyrox 25mg for the treatment of thyroid malfunction. He also took various supplements for the metabolism support and digestion regulation. Moreover, the patient underwent the corrective surgeries of cleft palate and talipes equinovarus.Lessons:We successfully identified the causative mutation NM_001144967.2(NEDD4L):c.2677G>A:p.Glu893Lys explaining symptoms overlapping those reported for PVNH7. Symptoms shared with the brother were not explained by this variant, since he was not a carrier of the pathogenic NEDD4L variant. These are most likely not extended phenotypes of PVNH7, rather an independent clinical entity caused by a yet unidentified genetic factor in the family, highlighting thus the importance of thorough evaluation of symptomatology and genomic findings in affected and unaffected family members, when such data are available.     

Molecular Imaging of Membrane Transporters’ Activity in Cancer: a Picture is Worth a Thousand Tubes

Molecular imaging allows the non-invasive assessment of membrane transporter expression and function in living subjects. Such technologies have the potential to become diagnostic and prognostic tools, allowing detection, localization, and prediction of response of tumors and their metastases to therapy. Beyond tumors, imaging can also help understand the role of transporters in adverse drug effects and drug clearance. Here, we review molecular imaging technologies that monitor transporter-mediated processes. We emphasize emerging probe substrates and potential clinical applications of imaging the function of membrane transporters in cancer.KEY WORDS: membrane transporters, molecular imaging, multidrug resistance, near infrared, optical imaging     

<Emphasis Type="Italic">Rickettsia</Emphasis> species in fleas collected from small mammals in Slovakia

Epidemiological and epizootiological studies of Rickettsia felis and other Rickettsia spp. are very important, because their natural cycle has not yet been established completely. In total, 315 fleas (Siphonaptera) of 11 species of Ceratophyllidae, Hystrichopsyllidae and Leptopsyllidae families were tested for the presence of Rickettsia species and Coxiella burnetii with conventional and specific quantitative real-time PCR assays. Fleas were collected from five rodent hosts (Myodes glareolus, Apodemus flavicollis, Apodemus agrarius, Microtus subterraneus, Microtus arvalis) and three shrew species (Sorex araneus, Neomys fodiens, Crocidura suaveolens) captured in Eastern and Southern Slovakia. Overall, Rickettsia spp. was found in 10.8 % (34/315) of the tested fleas of Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus uncinatus and Nosopsyllus fasciatus species. Infected fleas were coming from A. flavicollis, A. agrarius, and M. glareolus captured in Eastern Slovakia. C. burnetii was not found in any fleas. R. felis, Rickettsia helvetica, unidentified Rickettsia, and rickettsial endosymbionts were identified in fleas infesting small mammals in the Ko?ice region, Eastern Slovakia. This study is the first report of R. felis infection in C. solutus male flea collected from A. agrarius in Slovakia.     

Effect of Matrix Metalloproteinase Inhibition by Doxycycline on Myocardial Healing and Remodeling after Myocardial Infarction

Summary The aim of conducting this study was to assess the clinical relevance of matrix metalloproteinase (MMP) inhibition by doxycycline, an effective MMP inhibitor, in a rat model of extensive myocardial infarction (MI) and left ventricular (LV) dysfunction. Rats (n = 22) were subjected to extensive anterior MI. Doxycycline (25 mg SC, daily) or saline (control) injections were started for nine days thereafter. The effect of doxycycline on MMP activity in the infarcted and remote myocardium was measured by zymography, in another subgroup (n = 8), nine days after MI. Echocardiography and magnetic resonance imaging (MRI) studies were performed at one and thirty days after MI to assess LV remodeling and function. After 4 weeks, hearts were fixed, and subjected to morphometric and histological analysis. Compared with control, doxycycline treatment attenuated MMP-9 and -2 activity in both infarcted and remote myocardium. Serial echocardiography studies showed that doxycycline failed to attenuate scar thinning, LV dilatation and dysfunction. MRI study showed that doxycycline impaired LV compensatory hypertrophy. Furthermore, compared with control, doxycycline reduced vessel density (/mm² ± SEM) in the infarcted myocardium (84 ± 16 vs. 46 ± 9/mm², respectively; p < 0.05). Our work suggest that effective MMPs’ inhibition in the infarcted and remote myocardium by doxycycline does not prevent LV remodeling and dysfunction but impairs angiogenesis and compensatory LV hypertrophy. Our findings caution against aggressive, non-selective inhibition of MMPs in the early healing phase after MI.     

Dynamics of the heart rate variability and oxygen saturation response to acute normobaric hypoxia within the first 10 min of exposure

Although the heart rate variability (HRV) response to hypoxia has been studied, little is known about the dynamics of HRV after hypoxia exposure. The purpose of this study was to assess the HRV and oxygen saturation (SpO₂) responses to normobaric hypoxia (FiO₂ = 9·6%) comparing 1 min segments to baseline (normoxia). Electrocardiogram and SpO₂ were recorded during a 10‐min hypoxia exposure in 29 healthy male subjects aged 26·0 ± 4·9 years. Baseline HRV values were obtained from a 5‐min recording period prior to hypoxia. The hypoxia period was split into 10 non‐overlapping 1‐min segments and time domain HRV indexes (RMSSD and SDNN) were calculated for each segment. Differences (Δ) from baseline values were calculated and transformed using natural logarithm (Ln). This study revealed that the decrease in ΔSpO₂ became significant (P<0·001) in the first minute of hypoxia, the decrease in ΔLn RMSSD became significant (P = 0·002) in the second minute, and the decrease in ΔLn SDNN became significant (P = 0·001) in the third minute. Between the second and fifth minute of hypoxia, ΔSpO₂ correlated with ΔLn RMSSD (r = 0·57, P<0·001) and ΔLn SDNN (r = 0·44, P<0·001). Five min after the onset of hypoxia, ΔSpO₂ was significantly (P = 0·002) decreased but changes in ΔLn RMSSD (P = 0·344) and ΔLn SDNN (P = 0·558) were not significant. In conclusion, the decrease in HRV was proportional to desaturation but only during the first 5 min of hypoxia.