Left ventricular assist device implantation after plasma exchange for heparin-induced thrombocytopenia

Treating a patient with heparin-induced thrombocytopenia can be challenging particularly when the patient requires urgent cardiac surgery that uses heparin for anticoagulation. We herein report a case of a 61-year-old man with idiopathic dilated cardiomyopathy associated with heparin-induced thrombocytopenia and who underwent plasma exchange to remove heparin-induced thrombocytopenia antibodies before undergoing left ventricular assist device implantation. The surgery was performed using cardiopulmonary bypass and unfractionated heparin.     

Three‐dimensional structures of bacteriophage neck subunits are shared in Podoviridae,Siphoviridae and Myoviridae

Tailed bacteriophages (Caudovirales) are divided into three families: Myoviridae with long contractile tails, Siphoviridae with long noncontractile tails and Podoviridae with short noncontractile tails. All have an icosahedral head with a portal vertex connected to a neck structure followed by a tail. Bacteriophage Mu belongs to the Myoviridae family. Herein, the gp29 portal subunit and neck subunits gp35, gp36 and gp37 of the Mu phage were purified to elucidate their arrangement in the neck. Both gp29 and gp36 were monomeric in solution, like the corresponding subunits of Podoviridae P22 and Siphoviridae SPP1. X‐ray crystal structure of gp36 showed structural similarity to neck subunits of Siphoviridae and Podoviridae. The gp36 structure has a characteristic aromatic hydrophobic core, and the structure of the ring form of the Mu phage connector deduced from the Siphoviridae and Podoviridae connector showed that this feature builds the contact surface between gp36 subunits. Structural comparison with the neck of Siphoviridae and Podoviridae also implies direct interaction between gp36 and gp29. Because gp35 and gp36 form a stable complex, we predict that the head‐portal ring (gp29), the connector complex (gp36 and gp35), the tail terminator (gp37) and the tube (gp40) are arranged in the Mu phage neck in this order.     

RAF1–MEK/ERK pathway-dependent ARL4C expression promotes ameloblastoma cell proliferation and osteoclast formation

Ameloblastoma is an odontogenic neoplasm characterized by slow intraosseous growth with progressive jaw resorption. Recent reports have revealed that ameloblastoma harbours an oncogenic BRAFV600E mutation with mitogen-activated protein kinase (MAPK) pathway activation and described cases of ameloblastoma harbouring a BRAFV600E mutation in which patients were successfully treated with a BRAF inhibitor. Therefore, the MAPK pathway may be involved in the development of ameloblastoma; however, the precise mechanism by which it induces ameloblastoma is unclear. The expression of ADP-ribosylation factor (ARF)-like 4c (ARL4C), induced by a combination of the EGF–MAPK pathway and Wnt/β-catenin signalling, has been shown to induce epithelial morphogenesis. It was also reported that the overexpression of ARL4C, due to alterations in the EGF/RAS–MAPK pathway and Wnt/β-catenin signalling, promotes tumourigenesis. However, the roles of ARL4C in ameloblastoma are unknown. We investigated the involvement of ARL4C in the development of ameloblastoma. In immunohistochemical analyses of tissue specimens obtained from 38 ameloblastoma patients, ARL4C was hardly detected in non-tumour regions but tumours frequently showed strong expression of ARL4C, along with the expression of both BRAFV600E and RAF1 (also known as C-RAF). Loss-of-function experiments using inhibitors or siRNAs revealed that ARL4C elevation depended on the RAF1–MEK/ERK pathway in ameloblastoma cells. It was also shown that the RAF1–ARL4C and BRAFV600E–MEK/ERK pathways promoted cell proliferation independently. ARL4C-depleted tumour cells (generated by knockdown or knockout) exhibited decreased proliferation and migration capabilities. Finally, when ameloblastoma cells were co-cultured with mouse bone marrow cells and primary osteoblasts, ameloblastoma cells induced osteoclast formation. ARL4C elevation in ameloblastoma further promoted its formation capabilities through the increased RANKL expression of mouse bone marrow cells and/or primary osteoblasts. These results suggest that the RAF1–MEK/ERK–ARL4C axis, which may function in cooperation with the BRAFV600E–MEK/ERK pathway, promotes ameloblastoma development. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Capsular polysaccharide antibodies after pneumococcal polysaccharide vaccination in patients with chronic respiratory disease]

We investigated the antibody response to a 23-valent pneumococcal polysaccharide vaccine (23PSV), in 151 patients (average age: 70 years old) with chronic respiratory disease. Serotype-specific IgG antibodies to 4 pneumococcal capsular polysaccharides (6B, 14, 19F, and 23F) were analyzed by ELISA before, and one month after, 23PSV vaccination in all patients. Patients showed a significant increase in specific IgG levels to Streptococcus pneumoniae after 23PSV vaccination (5.5 times-20.9 times). Even patients aged over 80, patients with respiratory failure, and patients receiving corticosteroid therapy developed a significant immunologic response to 23PSV. Local pain or induration occurred in 9.1-14.3% and fatigue or chills occurred in 0.7-6.5% of patients. All adverse reactions disappeared in 2 or 3 days and there was no severe adverse events. Further studies are needed to confirm the exact protective antibody level and to examine the decline of antibody level after vaccination.     

Video‐assisted segmental resection of an intrapulmonary bronchogenic cyst mimicking a middle mediastinal cystic tumor

We report a case of an intrapulmonary bronchogenic cyst that radiologically mimicked a cystic tumor of the middle mediastinum. During video‐assisted thoracoscopic surgery, the lesion was confirmed to be in the lung parenchyma rather than in the mediastinum. A video‐assisted thoracoscopic anterior basal segmentectomy was eventually performed, and an intrapulmonary bronchogenic cyst was the diagnosis based on histology.     

A diagnosed, cured case of an HIV-infected Japanese subject developing disseminated penicilliosis after Thailand travel

Disseminated penicilliosis-an AIDS-indicator disease in Southeast Asian countries -but not Japan- is a systemic fungal infection caused by Penicillium marneffei. A 30-year-old HIV-positive Japanese man visiting Southeast Asia three months before admission and reporting fever, general fatigue, and enlarged lymph nodes lasting over one month was admitted for detailed tests. Blood culture and fine-needle aspiration lymph node biopsy a led to a diagnosis of disseminated penicillioisis, later cured by several anti-fungal agents. Caution is thus recommended regarding the possibility of this disease, given the large number of travelers visiting overseas, geographical proximity to Southeast Asia, and increasing numbers of HIV patients in Japan.     

GABAB receptor agonist baclofen improves methamphetamine-induced cognitive deficit in mice

In this study, we investigated the effects of GABA_A and GABA_B receptor agonists on the methamphetamine-induced impairment of recognition memory in mice. Repeated treatment with methamphetamine at a dose of 1 mg/kg for 7 days induced an impairment of recognition memory. Baclofen, a GABA_B receptor agonist, ameliorated the repeated methamphetamine-induced cognitive impairment, although gaboxadol, a GABA_A receptor agonist, had no significant effect. GABA_B receptors may constitute a putative new target in treating cognitive deficits in patients suffering from schizophrenia, as well as methamphetamine psychosis.     

Bone and joint tuberculosis concurrent with tuberculosis of other organs

OBJECTIVES: To study the characteristics of bone or joint tuberculosis (TB) accompanied by TB in other organs (especially the lung), and to study patients' and doctors' delay in detecting bone or joint TB. SUBJECTS AND METHODS: A retrospective study was conducted on 33 patients with bone or joint TB concurrent with TB of other organs, especially the lung, who were admitted to our hospital between 1981 and 2005. The patients were divided into the following three groups according to the organ of concurrent TB : (1) miliary TB group (N = 10), (2) pulmonary TB group (N = 19), and (3) other TB site group (N = 4). The relationship between bone/joint TB and TB of other organs was studied by comparing the three groups with respect to the time of appearance of musculo-skeletal symptoms or signs such as swelling and pain and that of symptoms or signs originating from other organs, such as cough, sputum, miliary pattern on chest radiograph and superficial lymph node swelling. RESULTS: The mean age (SD) of patients was 50.5 (18.9) yr, and the male to female ratio was 23 : 10. Among 33 patients, bone TB (including 18 spinal TB) was detected in 24 patients, joint TB in 14, and abscess in 3 (concurrent lesions in some patients). The mean intervals from onset of symptoms to consultation (patients' delay), from consultation to diagnosis (doctors' delay) and from symptom onset to diagnosis (total delay) were 5.5 (13.9), 3.4 (5.2) and 8.9 (13.9) months, respectively. (1) Bone/joint TB concurrent with miliary TB (N = 10) In 8 patients with mean age of 61.0 (17.4) yr, musculo-skeletal symptoms/signs preceded respiratory symptoms or appearance of miliary pattern on chest radiograph by 7.8 (7.2) (range; 1-24) months. The patients', doctors' and total delays were 0.4 (0.5), 7.3 (7.8), and 7.7 (7.6) months, respectively. In most cases, bone/joint TB was diagnosed after the onset of miliary pattern on chest radiograph. In one patient with simultaneous onset of musculo-skeletal and respiratory symptoms/signs (age 21 yr), the interval of total delay was 1 month, and in one patient with musculoskeletal symptoms which appeared six months later than respiratory symptoms (age 28 yr), the interval of total delay was 2 months. (2) Bone/joint TB concurrent with active pulmonary TB (N = 19). In this group, the mean age was 52.2 (17.1) yr, and males were predominant (M/F = 15/4). Active pulmonary TB was diagnosed by positive sputum culture in 13 patients, by positive sputum smear or PCR results in 4 patients, and by the clinical course in 2 patients. Ten patients (53%) had a previous TB history. Cavitary lesion was observed in 15 patients, and the upper lobes were predominantly involved on chest radiograph in 19 patients, indicating that the pulmonary TB was probably post-primary (reactivation) in all patients. In 9 patients with mean age of 49.7 (15.7) yr, musculo-skeletal symptoms/signs preceded respiratory symptoms by 14.1 (14.0) (range; 4-48) months. The patients', doctors' and total delays were 13.3 (17.8), 3.8 (6.6), and 17.1 (16.1) months, respectively. On the other hand, in 10 patients with mean age of 54.5 (18.7) yr, musculo-skeletal symptoms/signs and respiratory symptoms/signs appeared simultaneously, and the total delay was 2.7 (1.9) months. Twelve of 19 patients (63%) had complications such as diabetes mellitus, steroid use, and liver diseases. In cases with miliary or pulmonary tuberculosis, the total delay in diagnosis (Y) correlates positively with the time lag from onset of musculo-skeletal symptoms to respiratory symptoms/signs (X), and the regression line (Y = 0.94X + 2.3, r = 0.98, p < 0.001) was almost linear (Y = X), indicating that the diagnosis of bone/joint TB was made just after the diagnosis of miliary or pulmonary TB. (3) Bone/joint TB concurrent with TB of other sites (N = 4) In 2 female cases (21 and 28 yrs) with cervical lymph node TB, musculo-skeletal symptoms/signs and cervical lymph node swelling appeared simultaneously. In a 54-yr male patient, musculo-skeletal symptoms/signs appeared 5 years after appearance of testicular enlargement, and testicular TB was diagnosed by biopsy simultaneously. In a 33 year-old male patient, musculo-skeletal symptoms/signs appeared 7 months after the drainage of pleural and pericardial effusions (TB was not diagnosed initially), and then the diagnosis of bone/joint, pleural, and pericardial tuberculosis was made for the first time. CONCLUSIONS: In middle-aged or elderly patients with active bone/joint TB, miliary TB is sometimes caused by bacillemia originating from the infected bone/joint lesions. In cases with bone/joint TB and concurrent pulmonary TB, bone/joint TB and pulmonary TB are probably reactivated independently as a result of decreased systemic immunocompetence.