Publications by authors named "Kazuhiko Nakayama"

Recently, virus-like particles have been regarded as a promising platform for displaying foreign peptides or proteins on their surface. In this study, a dual-protein-displaying platform based on the norovirus-like particle (NoV-LP) was developed using SpyTag (SpT)/SpyCatcher (SpC) protein bioconjugation. A short 14-amino-acid SpT peptide was added to the C-terminus of VP1, with a rigid "EAAAK" spacer in between.

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Background: The European Chronic Thromboembolic Pulmonary Hypertension (CTEPH) registry, conducted between 2007 and 2012, reported the major impact of pulmonary endarterectomy (PEA) on the long-term survival of patients with CTEPH. Since then, 2 additional treatments for inoperable CTEPH have become available: balloon pulmonary angioplasty (BPA), and an approved oral drug therapy with the guanylate cyclase stimulator riociguat. The current registry aimed to evaluate the effect of these new therapeutic approaches in a worldwide context.

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  • The INCREASE trial demonstrated that inhaled treprostinil enhances exercise capacity in patients with pulmonary hypertension linked to interstitial lung disease (PH-ILD), but lacked specific hemodynamic and pharmacokinetic data.
  • A new trial in Japan evaluated the drug's effects on hemodynamics, exercise capacity, safety, and pharmacokinetics, administering inhaled treprostinil at escalating doses.
  • Results showed a significant reduction in pulmonary vascular resistance and an increase in walking distance over 16 weeks, along with manageable side effects like cough and low blood pressure, indicating the drug's efficacy and safety in this patient group.
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The bear roundworm Baylisascaris transfuga has been identified in several host bears (Ursinae). However, limited genetic information is available on the bear roundworm in Japanese populations. This study evaluated the genetic composition of bear roundworms isolated from wild Japanese black bears indigenous to Lake Towada, Japan.

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Background: Malaria, a global health concern, is caused by parasites of the Plasmodium genus, which undergo gametogenesis in the midgut of mosquitoes after ingestion of an infected blood meal. The resulting male and female gametes fuse to form a zygote, which differentiates into a motile ookinete. After traversing the midgut epithelium, the ookinete differentiates into an oocyst on the basal side of the epithelium.

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  • Recent guidelines recommend against using PAH-targeted therapies in patients with pulmonary hypertension (PH) linked to respiratory diseases, highlighting the need for better assessment of treatment effectiveness.
  • The study analyzed 270 patients with precapillary PH, categorizing them into severe and mild cases to evaluate the impact of initial treatments on their prognosis.
  • Findings indicated that patients with severe PH and mild ventilatory impairment who received initial treatment showed a significantly better response and prognosis compared to those who did not, while such benefits were not seen in mild PH cases.
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Plasmodium parasites within mosquitoes are exposed to various physiological processes, such as blood meal digestion activity, the gonotrophic cycle, and host responses preventing the entry of parasites into the midgut wall. However, when in vitro-cultured ookinetes are injected into the hemocoel of mosquitoes, Plasmodium parasites are not affected by the vertebrate host's blood contents and do not pass through the midgut epithelial cells. This infection method might aid in identifying mosquito-derived factors affecting Plasmodium development within mosquitoes.

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Background: Heart failure (HF) causes extracardiac organ congestion, including in the hepatic portal system. Reducing venous congestion is essential for HF treatment, but evaluating venous congestion is sometimes difficult in patients with chronic HF. The portal vein (PV) flow pattern can be influenced by right atrial pressure.

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  • Philopinna higai is a parasitic species found in fish of the Sarcocheilichthys genus, mainly in Lake Biwa and southwestern Japan, with a study investigating its presence in the northeastern Tohoku region.
  • Research confirmed P. higai’s distribution across seven river systems in Tohoku, showing no variation in 28S rDNA sequences but identifying 10 distinct haplotypes in the CO1 gene from the parasite.
  • The sarcocheilichthys fish in Tohoku shared identical haplotypes with those from Lake Biwa, indicating that while P. higai is genetically the same in both regions, the Tohoku population exhibits some genetic differentiation.
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Malaria needs new strategies for its control. Plasmodium spp., the causative agent of malaria, is transmitted by mosquitoes.

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Objective: To determine whether complications of pulmonary hypertension (PH) can be predicted by noninvasive screening tests in systemic sclerosis (SSc).

Methods: Forty-seven of 113 SSc patients underwent right heart catheterization (RHC) during 2011-2014. Clinical data, hemodynamic features, echocardiography, and pulmonary function tests had been followed up from the first RHC until 5 years later.

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Crithidia mellificae (C. mellificae) and Lotmaria passim (L. passim) are trypanosomatids that infect Apis mellifera.

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  • Malaria, caused by Plasmodium species, involves a complex life cycle where meiosis generates genetic variation through homologous recombination (HR), but the mechanisms of HR in Plasmodium are poorly understood.
  • A potential BRCA2 homolog, identified in Plasmodium berghei, was confirmed through interactions with Rad51 and involved in meiosis, leading to investigations into its role in parasite proliferation.
  • Knockout of PbBrca2 resulted in reduced parasite growth and differentiation in hosts, with alterations in life stages observed, although the overall morphology remained similar to wild-type parasites.
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Trichodectes pinguis, referred to commonly as the bear-biting louse, has been reported in several bear species. However, graphical (blurred or coarse) and genetic information on the louse is limited. In this study, we identified T.

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Background: Right ventricular (RV) afterload is widely assessed by pulmonary vascular resistance (PVR). However, RV afterload is underestimated because PVR does not account for the pulsatile load. The pulsatile load is often evaluated by pulmonary arterial compliance (PAC).

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Background: Pulmonary endarterectomy (PEA), pulmonary arterial hypertension (PAH) therapy and balloon pulmonary angioplasty (BPA) are currently accepted therapies for chronic thromboembolic pulmonary hypertension (CTEPH). This international CTEPH Registry identifies clinical characteristics of patients, diagnostic algorithms and treatment decisions in a global context.

Methods: 1010 newly diagnosed consecutive patients were included in the registry between February 2015 and September 2016.

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Background: Plasmodium sp., which causes malaria, must first develop in mosquitoes before being transmitted. Upon ingesting infected blood, gametes form in the mosquito lumen, followed by fertilization and differentiation of the resulting zygotes into motile ookinetes.

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The definitive hosts of Metagonimus hakubaensis are reported to be hamsters, rats, mice, dogs, cats, chickens, and quails in experimental infection and Japanese water shrews in natural infection. Here we report that raccoon dogs are new natural definitive hosts of M. hakubaensis, based on morphological and molecular analyses of Metagonimus flukes collected from the host species from Aomori Prefecture, Japan.

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Background: There is limited evidence for pulmonary arterial hypertension (PAH)-targeted therapy in patients with pulmonary hypertension associated with respiratory disease (R-PH). Therefore, we conducted a multicenter prospective study of patients with R-PH to examine real-world characteristics of responders by evaluating demographics, treatment backgrounds, and prognosis.

Methods and results: Among the 281 patients with R-PH included in this study, there was a treatment-naïve cohort of 183 patients with normal pulmonary arterial wedge pressure and 1 of 4 major diseases (chronic obstructive pulmonary diseases, interstitial pneumonia [IP], IP with connective tissue disease, or combined pulmonary fibrosis with emphysema); 43% of patients had mild ventilatory impairment (MVI), whereas 52% had a severe form of PH.

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The existence of microvasculopathy in patients with chronic thromboembolic pulmonary hypertension has been suggested. Recently, dual-energy computed tomography has been used to produce a sensitive iodine distribution map in lung fields to indicate microvasculopathy according to poor subpleural perfusion. Our aim was to evaluate the impact of microvasculopathy on pathophysiology in chronic thromboembolic pulmonary hypertension.

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Background/objective: Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary arterial pressure and pulmonary vascular resistance that can lead to right-sided heart failure. Connective tissue disease-associated PAH (CTD-PAH) often has poorer outcomes than idiopathic or hereditary PAH, suggesting the presence of non-PAH factors that could affect the prognoses. This cohort study aimed to identify prognostic factors for CTD-PAH management.

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Bosentan, an endothelin receptor antagonist, has been widely used as a first-line medication for the treatment of pulmonary arterial hypertension (PAH). It has been shown to improve symptoms of hypertension, exercise capacity, and hemodynamics and prolong time to clinical worsening. However, liver dysfunction is a major side effect of bosentan treatment that could hamper the optimal management of patients with PAH.

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Functional tricuspid regurgitation (FTR) is associated with prognosis for various heart diseases, but its association with pulmonary hypertension (PH) remains unclear. We studied 111 PH patients. Mid-term follow-up echocardiography was performed 7.

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This case report concerns a 22-year-old woman with large patent ductus arteriosus and atrial septal defect. She was referred to our hospital because of exertional dyspnea and was revealed to have advanced pulmonary arterial hypertension (PAH) with a mean pulmonary arterial pressure (PAP) of 79 mmHg. Although both shunts had bidirectional flow, based on the results of acute pulmonary vasoreactive testing, one-stage surgical closure was performed followed by up-front combination therapy for post-operative pulmonary hypertensive crisis and residual PAH.

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