Diagnosis of Primary Ciliary Dyskinesia via Whole Exome Sequencing and Histologic Findings.

PURPOSE: To assess the diagnostic potential of whole-exome sequencing (WES) and elucidate the clinical and genetic characteristics of primary ciliary dyskinesia (PCD) in the Korean population. MATERIALS AND METHODS: Forty-seven patients clinically suspected of having PCD were enrolled at a tertiary medical center. WES was performed in all patients, and seven patients received biopsy of cilia and transmission electron microscopy (TEM). RESULTS: Overall, PCD was diagnosed in 10 (21.3%) patients: eight by WES (8/47, 17%), four by TEM. Among patients diagnosed as PCD based on TEM results, two patients showed consistent results with WES and TEM of PCD (2/4, 50%). In addition, five patients, who were not included in the final PCD diagnosis group, had variants of unknown significance in PCD-related genes (5/47, 10.6%). The most frequent pathogenic (P)/likely pathogenic (LP) variants were detected in DNAH11 (n=4, 21.1%), DRC1 (n=4, 21.1%), and DNAH5 (n=4, 21.1%). Among the detected 17 P/LP variants in PCD-related genes in this study, 8 (47.1%) were identified as novel variants. Regarding the genotype-phenotype correlation in this study, the authors experienced severe PCD cases caused by the LP/P variants in MCIDAS, DRC1, and CCDC39. CONCLUSION: Through this study, we were able to confirm the value of WES as one of the diagnostic tools for PCD, which increases with TEM, rather than single gene tests. These results will prove useful to hospitals with limited access to PCD diagnostic testing but with relatively efficient in-house or outsourced access to genetic testing at a pre-symptomatic or early disease stage.

Isolation and characterization of a novel endo-beta-1, 4-glucanase from a metagenomic library of the black-goat rumen

ABSTRACT The various types of lignocellulosic biomass found in plants comprise the most abundant renewable bioresources on Earth. In this study, the ruminal microbial ecosystem of black goats was explored because of their strong ability to digest lignocellulosic forage. A metagenomic fosmid library containing 115,200 clones was prepared from the black-goat rumen and screened for a novel cellulolytic enzyme. The KG35 gene, containing a novel glycosyl hydrolase family 5 cellulase domain, was isolated and functionally characterized. The novel glycosyl hydrolase family 5 cellulase gene is composed of a 963-bp open reading frame encoding a protein of 320 amino acid residues (35.1 kDa). The deduced amino acid sequence showed the highest sequence identity (58%) for sequences from the glycosyl hydrolase family 5 cellulases. The novel glycosyl hydrolase family 5 cellulase gene was overexpressed in Escherichia coli. Substrate specificity analysis revealed that this recombinant glycosyl hydrolase family 5 cellulase functions as an endo-β-1,4-glucanase. The recombinant KG35 endo-β-1,4-glucanase showed optimal activity within the range of 30-50 °C at a pH of 6-7. The thermostability was retained and the pH was stable in the range of 30-50 °C at a pH of 5-7.

Alpers-Huttenlocher Syndrome First Presented with Hepatic Failure: Can Liver Transplantation Be Considered as Treatment Option?

Mitochondria play essential role in eukaryotic cells including in the oxidative phosphorylation and generation of adenosine triphosphate via the electron-transport chain. Therefore, defects in mitochondrial DNA (mtDNA) can result in mitochondrial dysfunction which leads to various mitochondrial disorders that may present with various neurologic and non-neurologic manifestations. Mutations in the nuclear gene polymerase gamma (POLG) are associated with mtDNA depletions, and Alpers-Huttenlocher syndrome is one of the most severe manifestations of POLG mutation characterized by the clinical triad of intractable seizures, psychomotor regression, and liver failure. The hepatic manifestation usually occurs late in the disease's course, but in some references, hepatitis was reportedly the first manifestation. Liver transplantation was considered contraindicated in Alpers-Huttenlocher syndrome due to its poor prognosis. We acknowledged a patient with the first manifestation of the disease being hepatic failure who eventually underwent liver transplantation, and whose neurological outcome improved after cocktail therapy.

Identification of disease comorbidity through hidden molecular mechanisms.

Despite multiple diseases co-occur, their underlying common molecular mechanisms remain elusive. Identification of comorbid diseases by considering the interactions between molecular components is a key to understand the underlying disease mechanisms. Here, we developed a novel approach utilizing both common disease-causing genes and underlying molecular pathways to identify comorbid diseases. Our approach enables the analysis of common pathologies shared by comorbid diseases through molecular interaction networks. We found that the integration of direct genetic sharing and indirect high-level molecular associations revealed significantly strong consistency with known comorbid diseases. In addition, neoplasm-related diseases showed high comorbidity patterns within themselves as well as with other diseases, indicating severe complications. This study demonstrated that molecular pathway information could be used to discover disease comorbidity and hidden biological mechanism to understand pathogenesis and provide new insight on disease pathology.

Endosonographic Features of Gastric Schwannoma: A Single Center Experience.

BACKGROUND/AIMS: Gastric schwannomas are rare benign mesenchymal tumors that are difficult to differentiate from other mesenchymal tumors with malignant potential, such as gastrointestinal stromal tumors. This study aimed to evaluate the characteristic findings of gastric schwannomas via endoscopic ultrasonography (EUS). METHODS: We retrospectively reviewed the EUS findings of 27 gastric schwannoma cases that underwent surgical excision at Pusan National University Hospital during 2007 to 2014. RESULTS: Gastric schwannomas were mainly located in the middle third of the stomach with a mean tumor size of 32 mm. All lesions exhibited hypoechoic echogenicity, and 24 lesions (88.9%) exhibited heterogeneous echogenicity. Seventeen lesions (63.0%) exhibited decreased echogenicity compared to the normal proper muscle layer. Distinct borders were observed in 24 lesions (88.9%), lobulated margins were observed in six lesions (22.2%), and marginal haloes were observed in 24 lesions (88.9%). Hyperechogenic spots were observed in 21 lesions (77.8%), calcifications were observed in one lesion (3.7%), and cystic changes were observed in two lesions (7.4%). CONCLUSIONS: During EUS, gastric schwannomas appear as heterogeneously hypoechoic lesions with decreased echogenicity compared to the normal proper muscle layer. These features may be helpful for differentiating gastric schwannomas from other mesenchymal tumors.

Variations in plasma and urinary lipids in response to enzyme replacement therapy for Fabry disease patients by nanoflow UPLC-ESI-MS/MS.

A deficiency of α-galactosidase A causes Fabry disease (FD) by disrupting lipid metabolism, especially trihexosylceramide (THC). Enzyme replacement therapy (ERT) is clinically offered to FD patients in an attempt to lower the accumulated lipids. Studies on specific types of lipids that are directly or indirectly altered by FD are very scarce, even though they are crucial in understanding the biological process linked to the pathogenesis of FD. We performed a comprehensive lipid profiling of plasma and urinary lipids from FD patients with nanoflow liquid chromatography electrospray-ionization tandem mass spectrometry (nLC-ESI-MS/MS) and identified 129 plasma and 111 urinary lipids. Among these, lipids that exhibited alternations (>twofold) in patients were selected as targets for selected reaction monitoring (SRM)-based high-speed quantitation using nanoflow ultra-performance LC-ESI-MS/MS (nUPLC-ESI-MS/MS) and 31 plasma and 26 urinary lipids showed significant elevation among FD patients. Higher percentages of sphingolipids (SLs; 48% for plasma and 42% for urine) were highly elevated in patients; whereas, a smaller percentage of phospholipids (PLs; 15% for plasma and 13% for urine) were significantly affected. Even though α-galactosidase A is reported to affect THC only, the results show that other classes of lipids (especially SLs) are changed as well, indicating that FD not only alters metabolism of THC but various classes of lipids too. Most lipids showing significant increases in relative amounts before ERT decreased after ERT, but overall, ERT influenced plasma lipids more than urinary lipids.

Unravelling the mechanism of action of enzyme replacement therapy in Fabry disease.

Fabry disease (FD) is a rare X-linked recessive glycosphingolipid-storage disorder caused by deficient activity of the lysosomal enzyme alpha-galactosidase A. Intravenous enzyme replacement therapy (ERT) has been used to supplement deficient enzyme activity in patients with FD. Despite its clinical effect and manifestations, clear criteria for the clinical effectiveness and cost-effectiveness of ERT have not been well established. In this study, we investigated the pharmacodynamic actions and short-term effects of ERT in patients with FD through direct molecular profiling from blood samples of patients before and after ERT. Based on this comparison, we observed that immune/inflammation-related pathways and growth factor-related pathways such as innate/adaptive immune pathway, lymphocyte proliferation and leukocyte proliferation were actively regulated under ERT. We also found that TINAGL1, DAAM2, CDK5R1 and MYO5B known to be related with clinical symptoms of FD showed increased levels after ERT, leading to the amelioration of clinical manifestations. Especially the catabolic process-related genes, including USP15 and ERUN1, showed direct increasing after ERT in vivo in male patients. These results suggest that male patients with FD respond more actively to ERT than do female patients with FD. Pathway analysis revealed that oxidative phosphorylation pathway-related genes are downregulated under ERT. ERT has a role to protect the proteins from oxidative damage and such deactivation of oxidative phosphorylation is one of direct pharmacodynamic actions of ERT. These results extended our understanding of the pathophysiology of ERT. To our knowledge, this is the first study to observe the molecular basis for the mechanism of ERT in vivo through the comprehensive comparison of transcriptome study with next-generation sequencing data.

Communicating Hydrocephalus Onset Following a Traumatic Tension Pneumocephalus.

The entrapment of intracranial air from the check valve system results in a tension pneumocephalus. It should be distinguished from simple pneumocephalus because they are intracranial space-occupying masses that can threaten life. Communicating hydrocephalus is a serious and frequent complication of post-traumatic head injury. Head injury is one of the most common causes in etiopathogenesis of communicating hydrocephalus. Here, we describe a case of a 65-year-old man who developed communicating hydrocephalus after a post-traumatic tension pneumocephalus. To the best of our knowledge, this is the first reported case of communicating hydrocephalus developed after a post-traumatic tension pneumocephalus. Although the exact pathogenic mechanisms underlying the cascade following trauma remain unclear, communicating hydrocephalus after a tension pneumocephalus could be considered a possible complication.

Endoscopic Submucosal Dissection for Gastric Subepithelial Tumors: A Single-Center Experience.

Background and Aims. Endoscopic submucosal dissection (ESD) has been accepted as a treatment modality for gastrointestinal epithelial tumors. Recently, ESD has been applied to resect subepithelial tumors (SETs) in the gastrointestinal tract, but clinical evidence on its efficacy and safety is limited. The aim of this study was to investigate the efficacy and safety of ESD for gastric SETs and to assess possible predictive factors for incomplete resection. Patients and Methods. Between January 2006 and December 2013, a total of 49 patients with gastric SET underwent ESD at our hospital. Clinicopathologic characteristics of patients and SETs, therapeutic outcomes, complications, and follow-up outcomes were evaluated. Results. The overall rates of en bloc resection and complete resection were 88% (43/49) and 84% (43/49), respectively. Complete resection rates in tumors originating from the submucosal layer were significantly higher than those in tumors originating from the muscularis propria layer (90% versus 56%, P = 0.028). In multivariate logistic regression analyses, tumor location (upper third: odds ratio [OR] 12.639, 95% confidence interval [CI] 1.087-146.996, P = 0.043) and layer of tumor origin (muscularis propria: OR 8.174, 95% CI 1.059-63.091, P = 0.044) were independently associated with incomplete resection. Procedure-related bleeding and perforation rates were both 4%. No recurrence was observed in patients with complete resection at a median follow-up period of 29 months (range: 7-83 months). Conclusions. ESD is an effective, safe, and feasible treatment for gastric SETs. The frequency of incomplete resection increases in tumors located in the upper third of the stomach and in those originating from the muscularis propria layer.

Germline mutation of Glu70Lys is highly frequent in Korean patients with von Hippel-Lindau (VHL) disease.

Von Hippel-Lindau (VHL) disease is an inherited tumor syndrome caused by germline mutations in the VHL tumor suppressor gene. It is characterized by hemangioblastoma in the central nervous system and retina, renal cell carcinoma, pancreatic tumor and cysts, and pheochromocytoma. In this study, we detected 26 germline mutations in the VHL gene of Korean patients, of which 1 was a novel mutation, c.417_418insT. We also integrated our data from this study with the published literature to identify 55 VHL germline mutations in Koreans, and identified a unique hotspot at codon 70. Nine unrelated patients (9/55, 16.4%) had the same amino-acid substitution at codon 70 (Glu70Lys) and showed VHL type 1 phenotypes. Although this mutation was shown to have a mild effect on VHL function, four of the nine patients (44.4%) subsequently developed multiple central nervous system hemangioblastomas or retinal hemangioblastoma. However, this hotspot has not been identified in Chinese or Japanese patients. This study provides information on the spectrum of VHL mutations in Korean VHL disease and contributes to a better understanding of VHL disease in terms of improvements in the clinical management of VHL families.

The first case of familial Mediterranean fever associated with renal amyloidosis in Korea.

Familial Mediterranean fever (FMF) is an auto-inflammatory disease characterized by periodic episodes of fever and recurrent polyserositis. It is caused by a dysfunction of pyrin (or marenostrin) as a result of a mutation within the MEFV gene. It occurs mostly in individuals of Mediterranean origin; however, it has also been reported in non-Mediterranean populations. In this report, we describe the first case of FMF in a Korean child. As eight-year-old boy presented recurrent febrile attacks from an unknown cause, an acute scrotum and renal amyloidosis. He also showed splenomegaly, lymphadenopathy, pleural effusion, ascites and elevated acute phase reactants. After MEFV gene analysis, he was diagnosed as FMF combined with amyloidosis.

Primary intestinal lymphangiectasia diagnosed by capsule endoscopy and double balloon enteroscopy.

Primary intestinal lymphangiectasia (PIL) is a rare disorder characterized by dilated intestinal lymphatics and the development of protein-losing enteropathy. Patients with PIL develop hypoalbuminemia, hypocalcemia, lymphopenia and hypogammaglobulinemia, and present with bilateral lower limb edema, fatigue, abdominal pain and diarrhea. Endoscopy reveals diffusely elongated, circumferential and polypoid mucosae covered with whitish enlarged villi, all of which indicate intestinal lymphangiectasia. Diagnosis is confirmed by characteristic tissue pathology, which includes dilated intestinal lymphatics with diffusely swollen mucosa and enlarged villi. The prevalence of PIL has increased since the introduction of capsule endoscopy. The etiology and prevalence of PIL remain unknown. Some studies have reported that several genes and regulatory molecules for lymphangiogenesis are related to PIL. We report the case of a patient with PIL involving the entire small bowel that was confirmed by capsule endoscopy and double-balloon enteroscopy-guided tissue pathology who carried a deletion on chromosome 4q25. The relationship between this deletion on chromosome 4 and PIL remains to be investigated.

X-linked myotubular myopathy in a family with two infant siblings: a case with MTM1 mutation.

X-linked myotubular myopathy (XLMTM) is a rare congenital muscle disorder, caused by mutations in the MTM1 gene. Affected male infants present severe hypotonia, and generalized muscle weakness, and the disorder is most often complicated by respiratory failure. Herein, we describe a family with 2 infants with XLMTM which was diagnosed by gene analysis and muscle biopsy. In both cases, histological findings of muscle showed severely hypoplastic muscle fibers with centrally placed nuclei. From the family gene analysis, the Arg486STOP mutation in the MTM1 gene was confirmed.

The First Report of Antrodia sitchensis (Polyporaceae, Basidiomycota) in Korea.

An unrecorded Antrodia species was collected in South Korea and based on morphological characteristics, the species was identified as Antrodia sitchensis. To confirm its affinity within the polypores, the phylogenetic relationships of A. sitchensis and allied species were established using large subunit rDNA sequences.

Cerrena aurantiopora sp. nov. (Polyporaceae) from eastern Asia.

A new species of polypore in genus Cerrena was discovered in Kangwon Province, Korea. The resupinate basidiocarp and light orange, poroid hymenophore were sufficiently different to be distinguished from previously recorded species of Cerrena, C. consors, C. cystidiata, C. sclerodepsis and C. unicolor. Based on the results of morphological and phylogenetic analyses, we propose this new polypore as Cerrena aurantiopora sp. nov.

Behavioral improvement after transplantation of neural precursors derived from embryonic stem cells into the globally ischemic brain of adolescent rats.

PURPOSE: We intended to determine whether transplanted neural precursors, derived from mouse embryonic stem (ES) cells, can migrate and differentiate into mature neurons and glial cells in damaged brains and improve functional deficits caused by global cerebral ischemic injury in adolescent rats. METHODS: Global ischemia was induced using the four-vessel occlusion method. ES cells that display enhanced expression of yellow fluorescent protein were co-cultured in N2 supplemented media with PA6 cells that had stromal derived inducing activity. Neural precursor cells were directly transplanted bilaterally into hippocampal C3 areas 2 weeks after induction of global ischemia. Assessments of the Morris water-maze test at eight weeks and, the Open field activity levels at two, four, six and eight weeks after transplantation were carried out according to standard methods. RESULTS: From neural precursors, we were able to generate neural lineages, including neurons and glial cells in vitro. Eight weeks following transplantation, cellular migration as well as generation of neural cells including neurons, astrocytes, and oligodendrocytes developed from the grafted ES cell-derived neural precursors were observed. Cell-transplanted animals exhibited enhanced functional recovery on sensorimotor and behavioral tests, compared to vehicle-treated control animals. CONCLUSION: Therefore, transplantation of mouse ES cell-derived neural precursor cells shows promise for improving recovery after global ischemia in adolescent rats.

The first report of two species of Polyporus (Polyporaceae, Basidiomycota) from South Korea.

Based on morphological examination, two species of Polyporus, P. dictyopus, and P. tuberaster, were identified, which constitutes the first record of these species in South Korea. To confirm their affinity within the genus Polyporus, the phylogenetic relationships of Polyporus and allied genera were established from nuclear large subunit ribosomal DNA (nLSU rDNA) sequences, and a morphological diagnostic key is presented to clarify the Korean species of Polyporus.