Ultrasound and computed tomography findings of hepatic portal venous gas associated with acute appendicitis in a paediatric patient: A case report.

Introduction: Hepatic portal venous gas is a rare and life-threatening condition characterised by the presence of gas in the portal vein. Hepatic portal venous gas is frequently associated with intestinal ischaemia and necrosis. We present the case of a paediatric patient with acute appendicitis with hepatic portal venous gas detected using ultrasonography. Case report: A 5-year-old boy was admitted to our hospital with a respiratory tract infection. The boy started vomiting on day 2 of hospitalisation. He did not complain of any symptoms due to developmental retardation. We performed bedside point-of-care ultrasound, which detected hepatic portal venous gas, although the appendix could not be detected due to an acoustic shadow associated with bowel gas. Contrast-enhanced computed tomography revealed perforated appendicitis and pneumatosis intestinalis associated with paralytic ileus. An emergency laparoscopic appendectomy was performed. He was discharged on day 25 of hospitalisation after antibiotic therapy. Discussion: The present case suggests that the mechanism of hepatic portal venous gas was paralytic ileus, which caused gas-forming bacterial proliferation. The gas produced by bacteria and/or the gas-forming bacteria entered the bowel wall, which caused pneumatosis intestinalis. The bubbles in the intestinal wall floated in the portal system and were detected as hepatic portal venous gas. Perforated appendicitis and paralytic ileus seemed to be caused by a delayed diagnosis of appendicitis. The point-of-care ultrasound examination was useful for detecting hepatic portal venous gas and for helping establish the diagnosis of appendicitis. Conclusion: Hepatic portal venous gas is a rare finding associated with appendicitis in children. In addition, point-of-care ultrasound is useful for detecting hepatic portal venous gas in paediatric patients.

Childhood primary angiitis of the central nervous system following COVID-19 vaccination (BNT162b2/Pfizer-BioNtech): A case report.

Childhood primary angiitis of the central nervous system (cPACNS) is a vasculitis of unknown etiology that is confined to the central nervous system (CNS) and can lead to repeated cerebral infarctions if left untreated. Several cases of cPACNS after COVID-19 have been reported. Herein, we present a case of post-vaccination cPACNS. A 9-year-old healthy boy presented with persistent headache and fever after receiving the second COVID-19 vaccine (BNT162b2/Pfizer-BioNtech) dose. Brain magnetic resonance angiography (MRA) performed on the sixth day of symptom onset after vaccination revealed stenosis of the left middle cerebral artery; the patient was referred to our department on the 12th day of symptom onset. Blood tests indicated only minimal evidence of inflammation, whereas cerebrospinal fluid examination indicated pleocytosis. Brain magnetic resonance imaging (MRI) revealed vascular wall thickening and contrast enhancement of the artery with worsened stenosis. We diagnosed the patient as having cPACNS and treated him with three courses of methylprednisolone pulse therapy. The headaches and fever disappeared with improvement of vascular stenosis. The patient has been in remission for more than 1 year since cPACNS onset. This is the first report of a case of cPACNS after mRNA vaccination for COVID-19. Most previous cases of COVID-19-associated cPACNS presented with ischemic stroke. However, the present case could be treated for vasculitis prior to stroke and thus had a favorable prognosis. The mRNA vaccine for COVID-19 differs from other existing vaccines, and further accumulation of data of cases is required to determine adverse CNS reactions.

Interleukin-33/ST2 Axis as Potential Biomarker and Therapeutic Target in Kawasaki Disease.

Kawasaki disease (KD) is an acute, self-limiting, febrile systemic vasculitis of unknown cause associated with the development of coronary artery lesions (CALs) during childhood. Damage-associated molecular patterns (DAMPs) from cell death and oxidative stress have been shown to be involved in the development of KD vasculitis. Interleukin (IL)-33 is released from damaged endothelial cells and acts as a DAMP. We studied whether IL-33 and its receptor (ST2) might be involved in KD pathogenesis. Serum levels of soluble ST2 (sST2) in KD patients were measured before their first therapy. Furthermore, we investigated the impact of IL-33 on human coronary artery endothelial cells (HCAECs). Serum levels of sST2 were significantly higher in KD patients with CALs than in those with normal coronary arteries. In vitro, IL-33 upregulated the expression of ST2L and increased production of sST2, IL-6, IL-8, and monocyte chemoattractant protein-1 in HCAECs in a time- and concentration-dependent manner. Moreover, IL-33 induced significantly greater production of IL-6 and IL-8 in HCAECs compared to the condition stimulated with isoconcentration of tumor necrosis factor-α. The results of the present study suggest that the IL-33/ST2 axis might be involved in the development of KD vasculitis. The IL-33/ST2 axis may be a therapeutic target for the treatment of KD.

Successful Mitral Valve Replacement in an Infant with Neonatal Marfan Syndrome due to a Novel Missense Mutation of the FBN1 Gene.

Marfan syndrome is an autosomal dominant genetic disorder of the fibrous connective tissue caused by pathogenic mutations in the fibrillin-1 gene. Neonatal Marfan syndrome is a rare type of Marfan syndrome that is genotypically and phenotypically different from classical Marfan syndrome and has a poor prognosis. Most patients with neonatal Marfan syndrome die during infancy due to severe and rapidly progressive cardiovascular disorders. Here, we present a case of an 11-year-old girl with neonatal Marfan syndrome due to a novel missense mutation in exon 27 of the fibrillin-1 gene. Her condition was critical due to progressive mitral and tricuspid regurgitation. Mitral valve replacement, performed at the age of 6 months, improved her critical condition. Our case suggests that early mitral valve replacement may lead to better outcomes in patients with neonatal Marfan syndrome.

Responses to Treatment According to the Cytokine Profiles of Pericardial Effusion in Two Children with Idiopathic Pericarditis.

Acute pericarditis is inflammation of the pericardium with or without pericardial effusion. In the pediatric population, most patients with acute pericarditis are diagnosed with idiopathic pericarditis. Herein, we present two children with idiopathic pericarditis who underwent immunological assessment of pericardial effusion for the first time. Both patients showed equally high levels of interleukin-6 in the pericardial effusion. However, they had different treatment responses, in accordance with the pericardial effusion and serum interleukin-10 concentrations. Our present cases suggest that interleukin-10 may be associated with the response to anti-inflammatory therapy in idiopathic acute pericarditis.

Cerebral Insufficiency Caused by Diazoxide in a Premature Neonate with Congenital Hyperinsulinism.

Diazoxide is a peripheral vasodilator that has been used for intravenous treatment of hypertensive emergencies. However, it is currently used mainly for hyperinsulinemic hypoglycemia in lower dose orally, and its major side effects are edema and pulmonary hypertension. Herein, we report the first association between periventricular leukomalacia (PVL) and intractable hypotension due to diazoxide. A Japanese female premature infant showed hypoglycemia concomitant with hyperinsulinemia. She was diagnosed with congenital hyperinsulinism, and oral diazoxide was started. Six days after starting diazoxide, she suddenly showed peripheral coldness, oliguria, and severe hypotension. The hypotension was refractory to general vasopressor therapies and persisted even after the discontinuation of diazoxide. Cranial echography showed periventricular echodensities followed by cystic PVL. Low-dose vasopressin effectively treated the hypotension. This single case reminds us the serious adverse events of diazoxide that have been forgotten, especially in premature neonates.