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1.
World J Transplant ; 14(2): 92137, 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38947967

ABSTRACT

BACKGROUND: Lung transplantation is a well-established treatment of end-stage lung disease. A rodent model is an inexpensive way to collect biological data from a living model after lung transplantation. However, mastering the surgical technique takes time owing to the small organ size. AIM: To conduct rat lung transplantation using a shunt cannula (SC) or modified cannula (MC) and assess their efficacy. METHODS: Rat lung transplantation was performed in 11 animals in the SC group and 12 in the MC group. We devised a method of rat lung transplantation using a coronary SC for coronary artery bypass surgery as an anastomosis of pulmonary arteriovenous vessels and bronchioles. The same surgeon performed all surgical procedures in the donor and recipient rats without using a magnifying glass. The success rate of lung transplantation, operating time, and PaO2 values were compared after 2-h reperfusion after transplantation. RESULTS: Ten and 12 lungs were successfully transplanted in the SC and MC groups, respectively. In the SC group, one animal had cardiac arrest within 1 h after reperfusion owing to bleeding during pulmonary vein anastomosis. The operating time for the removal of the heart-lung block from the donor and preparation of the left lung graft was 26.8 ± 2.3 and 25.7 ± 1.3 min in the SC and MC groups, respectively (P = 0.21). The time required for left lung transplantation in the recipients was 37.5 ± 2.8 min and 35.9 ± 1.4 min in the SC and MC groups, respectively (P = 0.12). PaO2 values at 2 h after reperfusion were 456.2 ± 25.5 and 461.2 ± 21.5 mmHg in the SC and MC groups, respectively (P = 0.63), without difference between the groups. CONCLUSION: A hyperacute rat lung transplantation model using a coronary SC was created using a simple technique. The MC was inexpensive, easy to prepare, and simple to operate.

2.
Cancer Diagn Progn ; 4(4): 459-463, 2024.
Article in English | MEDLINE | ID: mdl-38962536

ABSTRACT

Background/Aim: Treatments for early laryngeal squamous cell carcinoma (SCC) include radiotherapy (RT), chemoradiotherapy (CRT), and larynx-preserving surgery. In this study, early laryngeal SCC was treated with RT in patients with stage I (T1N0) tumors and with CRT and docetaxel (DOC) in patients with stage II (T2N0) tumors and the treatment results and effectiveness of the chemotherapy were compared. Patients and Methods: A total of 78 patients with early-stage laryngeal SCC were enrolled in this study. The T1N0 patients received radiation for the primary lesions as outpatients at a total dose of 63-70 Gy. By contrast, the T2N0 patients were hospitalized and treated with CRT, receiving a total radiation dose of 66-70 Gy. Docetaxel (DOC, 10 mg/m2) was administered intravenously once a week for 6-8 consecutive weeks concurrently with radiotherapy. The adverse events and survival rates with local control rates were examined. Results: The number of non-glottic T2N0 patients was significantly higher than that of T1N0 patients. Although all patients completed their treatment schedule, significantly more grade 3 adverse events were observed in the T2N0 patients, in particular mucositis and dermatitis, than in T1N0 patients. The 5-year overall survival rate, disease specific survival rate, local control rate, and laryngeal preserve rate of the T1N0 and T2N0 patients were 86.1, 93.3, 88.6, and 94.3% and 85.9, 88.0, 93.1, and 93.1%, respectively. Conclusion: CRT with docetaxel showed the best therapeutic outcomes for the treatment of laryngeal SCC in patients with T2N0 tumours, with a higher local control rate, effective laryngeal preservation, and relatively few adverse events.

3.
J Clin Med ; 13(11)2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38893025

ABSTRACT

Background/Objectives: Particle beam therapy (PBT) was approved in April 2018 for head and neck malignancies and has since been introduced as a radical therapy for parotid malignancies. However, its prevalence and effectiveness in relation to surgical treatment have not been investigated. Methods: In this study, we evaluated 36 patients with parotid malignancy who underwent surgery (n = 26) or PBT (n = 10) and then analyzed the annual changes in the number of patients, survival rates, and clinical factors affecting prognosis. Results: Of the ten patients who opted for PBT, two and eight patients underwent PBT before and after 2018, respectively. There was a significant difference between these two groups of patients (p = 0.04). Of the ten patients who underwent PBT, five patients were recurrent cases; meanwhile, all twenty-six patients who underwent surgery were receiving initial treatment. Only one patient in each group had local recurrence after the treatment. Conclusions: The use of PBT as a radical therapy for parotid malignancies has been increasing since 2018, and patients with recurrent tumors tended to choose PBT. The outcome of the patients who underwent PBT did not seem to be inferior compared with those of the patients who underwent surgery. The histopathological type was a crucial issue in the outcomes of patients who underwent radical therapy for parotid malignancies.

4.
Article in English | MEDLINE | ID: mdl-38941034

ABSTRACT

Many patients visit outpatient clinics suffering from cervical lymphadenopathy. For those patients, ultrasonography is useful in differentiating inflammatory diseases and malignant tumors. On ultrasonographic images, normal lymph nodes are indicated as hypoechogenic masses with a well-defined border. The medullary portion near the lymph node hilum is hyperechogenic, so-called fatty hilum (FH). Color Doppler imaging reveals that blood flows from the lymph node hilum to FH. In lymph node metastasis, a metastatic focus grows within lymph nodes, which displaces and destroys the structure of normal lymph nodes. Ultrasonography can be used to detect FH, disappearance and unevenness of blood flow within lymph nodes, cyst formation, and so on. It is important to closely observe the inside of lymph nodes and make a diagnosis via ultrasonography, based on the criteria for diagnosing lymph node metastasis from head and neck squamous cell carcinoma. Additionally, it is also necessary to distinguish among inflammatory lymphadenopathy and malignant lymphoma.

5.
Pediatr Res ; 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38902452

ABSTRACT

BACKGROUND: Children born with very low birth weight (VLBW) are at higher risk for cognitive impairment, including language deficits and sensorimotor difficulties. Voice-evoked response (P1m), which has been suggested as a language development biomarker in young children, remains unexplored for its efficacy in VLBW children. Furthermore, the relation between P1m and sensory difficulties in VLBW children remains unclear. METHODS: 40 children with VLBW were recruited at 5-to-6 years old (26 male, 14 female, mean age of months ± SD, 80.0 ± 4.9). We measured their voice-evoked brain response using child-customized magnetoencephalography (MEG) and examined the relation between P1m and language conceptual inference ability and sensory characteristics. RESULTS: The final sample comprised 36 children (23 boys, 13 girls; ages 61-86 months; gestational ages 24-36 weeks). As a result of multiple regression analysis, voice-evoked P1m in the left hemisphere was correlated significantly with language ability (ß = 0.414 P = 0.015) and sensory hypersensitivity (ß = 0.471 P = 0.005). CONCLUSION: Our findings indicate that the relation between P1m and language conceptual inference ability observed in term children in earlier studies is replicated in VLBW children, and suggests P1m intensity as a biomarker of sensory sensitivity characteristics. IMPACT: We investigated brain functions related to language development and sensory problems in very low birth-weight children. In very low birth weight children at early school age, brain responses to human voices are associated with language conceptual inference ability and sensory hypersensitivity. These findings promote a physiological understanding of both language development and sensory characteristics in very low birth weight children.

6.
Neuroimage ; 292: 120589, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38575041

ABSTRACT

Child maltreatment can adversely affect brain development, leading to vulnerabilities in brain structure and function and various psychiatric disorders. Among the various types of child maltreatment, neglect has the highest incidence rate (76.0%); however, data on its sole adverse influence on the brain remain limited. This case-control brain magnetic resonance imaging (MRI) study identified the changes in gray matter structure and function that distinguish neglected children with no other type of maltreatment (Neglect group, n = 23) from typically developing children (TD group, n = 140), and investigated the association between these structural and functional differences and specific psychosocial phenotypes observed in neglected children. Our results showed that the Neglect group had a larger right and left anterior cingulate cortex (R/L.ACC) and smaller left angular gyrus (L.AG) gray matter volume. The larger R/L.ACC was associated with hyperactivity and inattention. Resting-state functional analysis showed increased functional connectivity (FC) between the left supramarginal gyrus (L.SMG) in the salience network (SN) and the right middle frontal gyrus (R.MFG) simultaneously with a decrease in FC with the L.ACC for the same seed. The increased FC for the R.MFG was associated with difficulty in peer problems and depressive symptoms; a mediating effect was evident for depressive symptoms. These results suggest that the structural atypicality of the R/L.ACC indirectly contributes to the disturbed FCs within the SN, thereby exacerbating depressive symptoms in neglected children. In conclusion, exposure to neglect in childhood may lead to maladaptive brain development, particularly neural changes associated with depressive symptoms.


Subject(s)
Brain , Child Abuse , Magnetic Resonance Imaging , Humans , Child , Male , Female , Child Abuse/psychology , Brain/diagnostic imaging , Brain/physiopathology , Brain/pathology , Gray Matter/diagnostic imaging , Gray Matter/pathology , Case-Control Studies , Connectome , Nerve Net/diagnostic imaging , Nerve Net/physiopathology
8.
Oral Maxillofac Surg ; 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38528193

ABSTRACT

PURPOSE: The aim of this retrospective study was to determine orthognathic surgery indicators for Japanese patients with jaw deformities using both Index of Orthognathic Functional Treatment Needs (IOFTN) and maxillofacial morphometric analysis. SUBJECTS AND METHODS: The subjects were 89 patients treated with orthognathic surgery and 92 patients treated with orthodontic treatment alone, and were classified as class I, II, or III according to the ANB angle. Based on the results for IOFTN and the results of cephalometric analysis, the indication criteria for orthognathic surgery were examined. RESULTS: In IOFTN analysis, none of patients in the orthognathic surgery group were classified as category 1 or 2, while 48% of the patients in the orthodontic treatment group were classified as category 4 or 5. The results of the cephalometric analysis of patients in classified categories 4 and 5 showed that the orthognathic surgery group had significantly greater lateral mandibular deviation in Class I cases, significantly more severe degree of mandibular retrusion in Class II cases, and significantly more severe degree of mandibular prognathism in Class III cases. The results of the logistic regression analysis showed that IOFTN was a common variable as an indication criterion for orthognathic surgery, and several different variables were also selected from the cephalometric measurements in each group. CONCLUSION: IOFTN is a highly sensitive and useful indicator as a criterion for orthognathic surgery. However, in the choice of treatment strategy, maxillofacial morphometric analyses and the patient's desired goal are important.

9.
J Gastroenterol ; 59(4): 302-314, 2024 04.
Article in English | MEDLINE | ID: mdl-38277006

ABSTRACT

BACKGROUND: Hospitalization for ulcerative colitis (UC) is potentially life-threatening. Severe disease in the Japanese criteria which modifies the Truelove-Witts' criteria might encompass more fulminant cases than the definition for acute severe UC. However, few studies have investigated the predictive factors for clinical remission (CR) after medical treatments for severe hospitalized patients by Japanese criteria. METHODS: Medical treatment selection, CR rates, and factors contributing to CR on day 14 were assessed in severe patients by Japanese criteria. We also investigated whether the reduction rate in patient-reported outcome 2 (PRO2) on day 3 could predict short-term prognosis. RESULTS: Eighty-five severe hospitalized patients were selected. Corticosteroids, tacrolimus, and infliximab were mainly selected as first-line treatments (76/85; 89.4%). The CR rates on day 14 were 26.8%, 21.4%, and 33.3% in patients receiving corticosteroids, tacrolimus, and infliximab, respectively. Extensive disease (odds ratio [OR] 0.022; 95% confidence interval [CI] 0.002-0.198), higher PRO2 (OR 0.306; 95% CI 0.144-0.821), and higher reduction rate in PRO2 on day 3 (OR 1.047; 95% CI 1.019-1.075) were independent factors predicting CR on day 14. If the cutoff value for the reduction rate in PRO2 on day 3 was 18.3%, sensitivity was 0.714 and specificity was 0.731 to predict CR on day 14. A higher reduction rate in PRO2 on day 3 (OR 0.922; 95% CI 0.853-0.995) was a negative factor to predict surgery within 28 days. CONCLUSIONS: Tacrolimus and infliximab in addition to corticosteroids were used as first-line treatment in severe hospitalized patients. PRO2 on day 3 is a useful marker for switching to second-line therapy or colectomy.


Subject(s)
Colitis, Ulcerative , Humans , Colitis, Ulcerative/diagnosis , Colitis, Ulcerative/drug therapy , Colitis, Ulcerative/chemically induced , Infliximab/therapeutic use , Immunosuppressive Agents/therapeutic use , Tacrolimus/therapeutic use , Japan , Adrenal Cortex Hormones/therapeutic use , Treatment Outcome , Colectomy , Retrospective Studies
11.
Anticancer Res ; 44(1): 403-407, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38159973

ABSTRACT

BACKGROUND/AIM: Despite the global rise in the incidence of human papillomavirus (HPV)-positive oropharyngeal carcinoma (OPC) in recent years, its prevalence and oncological outcomes in patients living in rural areas of Northern Japan has not been explored and should be investigated. PATIENTS AND METHODS: A total of 105 patients with oropharyngeal squamous cell carcinoma who underwent HPV screening and received first-line treatment were included in this study. The annual changes in the number of patients, survival rates, and clinical factors affecting prognosis were examined. RESULTS: The HPV-positive rate in patients with OPC was low, with the lowest rate of 10.0% in 2013 and the highest rate of 46.7% in 2020. The number of HPV-negative cases remained almost unchanged, whereas the overall number of cases increased with the increasing number of HPV-positive cases. Additionally, HPV-positive cases exhibited a fairly good prognosis. CONCLUSION: The number of OPC cases increased not only in urban areas, but also in rural areas. HPV-positive cases had better outcomes than HPV-negative cases.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Oropharyngeal Neoplasms , Papillomavirus Infections , Humans , Squamous Cell Carcinoma of Head and Neck , Carcinoma, Squamous Cell/epidemiology , Carcinoma, Squamous Cell/therapy , Japan/epidemiology , Papillomavirus Infections/complications , Papillomavirus Infections/epidemiology , Papillomavirus Infections/diagnosis , Retrospective Studies , Oropharyngeal Neoplasms/epidemiology , Oropharyngeal Neoplasms/therapy , Oropharyngeal Neoplasms/pathology , Prognosis , Papillomaviridae
12.
Clin Case Rep ; 11(12): e8330, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38094138

ABSTRACT

Key Clinical Message: Angiosarcoma is a rare malignant disease with an extremely poor prognosis, showing rapid progression of the local tumor and/or distant metastases. Although multidisciplinary approach including systemic chemotherapy and radiation therapy is ideal for this disease, surgical resection have a role in disease control and should be performed as soon as possible. Abstract: Angiosarcomas originating from the tongue are rare and have extremely malignant features, leading to a poor prognosis. Herein, we report the case of a patient with angiosarcoma arising from the tongue who was successfully treated surgically. A 71-year-old man was diagnosed with a mass on the right side of his tongue and visited the Department of Oral and Maxillofacial Surgery at our hospital. The patient was referred to our department for further examination and treatment after a biopsy of the right edge of the tongue. An irregularly raised tumor 50 mm in length was noted on the right lingual border. The preoperative diagnosis was a primary angiosarcoma of the tongue (clinical stage, T3N2bM0, Stage IV). As his tumor had been growing rapidly, he emergently underwent partial right-sided tongue resection and right neck dissection without reconstructive surgery. The histopathological diagnosis was pT3N0. Postoperatively, the patient showed no signs of recurrence or metastasis during the 1-year follow-up. As for angiosarcomas, surgical resection is the only curative treatment, and surgery should be performed as soon as possible after the final diagnosis.

13.
Case Rep Gastroenterol ; 17(1): 339-345, 2023.
Article in English | MEDLINE | ID: mdl-38020466

ABSTRACT

A 19-year-old man with a history of Peutz-Jeghers syndrome (PJS) and two previous partial small bowel resections because of intussusception presented with lower abdominal pain. Computed tomography (CT) showed concentric multilayer and cord-like structures in the transverse colon. Colo-colonic intussusception was suspected and he was hospitalized. After two therapeutic enemas were unsuccessful, a colonoscopy was performed. The intussusception was reduced and a 40-mm transverse colon polyp with a thick stalk was resected. After the procedure, his abdominal pain was relieved and he was discharged on the sixth hospital day. This case and several previous reports suggest that PJS polyps with tumor diameter exceeding 30 mm and location in the transverse or sigmoid colon can cause intussusception. Endoscopic treatment should be considered for these lesions.

14.
JGH Open ; 7(11): 777-782, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38034048

ABSTRACT

Background and Aim: Cold snare polypectomy (CSP) for small colorectal polyps is a safe technique; however, there is little evidence on whether dietary restriction after CSP is essential. This study aimed to determine whether dietary restriction after CSP is necessary to prevent delayed bleeding. Methods: This is a randomized, controlled, non-inferiority trial conducted between November 2021 and March 2022. Patients with non-pedunculated small colorectal polyps (<10 mm) and who did not take anticoagulants were randomly allocated to two groups: (i) the normal diet (ND) group, and (ii) the low-residue diet (LRD) group. The ND group was instructed to eat anything after CSP, whereas the LRD group was advised to take LRD for 3 days after CSP. The primary endpoint was the occurrence of delayed major bleeding that needed endoscopic hemostasis. Results: A total of 193 patients (average 57.5 years old, 51.9% male) were enrolled in the study. Subsequently, 97 and 96 patients were allocated to the ND and LRD group, respectively. The occurrence of delayed major bleeding was 1.0% in the ND group and 2.1% in the LRD group (95% confidence interval [CI]: -4.4% to 2.4%; difference: -1.1%), which showed the non-inferiority of the ND group. In addition, there was no difference between the two groups with respect to the occurrence of minor delayed bleeding (3.1% and 4.2%, respectively; difference: -1.1% [95% CI: -6.4% to 4.2%]). Conclusion: Dietary restriction after CSP for low-bleeding-risk colorectal polyps is not necessary for the prevention of delayed bleeding (Registration number: UMIN000045669).

15.
J Gastroenterol ; 58(12): 1198-1210, 2023 12.
Article in English | MEDLINE | ID: mdl-37831183

ABSTRACT

BACKGROUND: This multicenter observational cohort study aimed to evaluate the utilization and short-term efficacy of advanced therapy (AT) in hospitalized patients with acute severe ulcerative colitis (ASUC). METHODS: In total, 221 patients with ASUC were enrolled between August 2020 and July 2021. The primary endpoint was clinical remission (CR, defined as a patient-reported outcome score < 2 with no blood in the stool) rate on Day 7 and 14 in hospitalized patients who received corticosteroids (CS) and AT. RESULTS: Among patients with ASUC, 120 and 101 patients received CS or any AT as first-line treatment, respectively. The CR rates on Day 7 and 14 were 22.5% and 35.0%, respectively, in hospitalized patients who received CS as first-line treatment. Most patients who used ATs had CS-dependent or frequent recurrences. Eight different ATs (apheresis, tacrolimus, infliximab, golimumab, tofacitinib, vedolizumab, ustekinumab, and cyclosporine) were used as first-line treatment in patients with ASUC, and the CR rates on Day 7 and 14 were 16.8% and 29.7%, respectively. Twenty-five patients received the second ATs after hospitalizations, and the CR rates on Day 7 and 14 were 0% and 12%, respectively. The CR rates on Day 14 were significantly higher in patients who changed to AT than in those whose dose of CS increased (34.0% vs 10.7%, p = 0.020) among patients who had already used CS before hospitalization. CONCLUSION: Most first-use ATs were effective for patients with ASUC, while second-use ATs might have had limited benefits in inducing CR. These findings may contribute to considerations for the management of hospitalized patients.


Subject(s)
Colitis, Ulcerative , Humans , Colitis, Ulcerative/drug therapy , Treatment Outcome , Infliximab/adverse effects , Tacrolimus/therapeutic use , Adrenal Cortex Hormones/therapeutic use
16.
Respirol Case Rep ; 11(11): e01237, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37854460

ABSTRACT

Endobronchial lipomas are rare; nonetheless, physicians should consider them as a differential diagnosis in patients with repeated pneumonia. Computed tomography and bronchoscopy are recommended for diagnosis. In this case, the patient's cough was ameliorated after undergoing a right basal segmentectomy.

17.
Kyobu Geka ; 76(9): 726-730, 2023 Sep.
Article in Japanese | MEDLINE | ID: mdl-37735734

ABSTRACT

Scimitar syndrome is a subtype of partial anomalous pulmonary venous connection, a rare congenital disorder associated with hypoplasia of the right lung. In addition to the difficulty of isolated lung ventilation, resection of the left lung is associated with the risk of developing right heart failure due to increased right-to-left shunts. We report a case of a left lung metastasis of a patient with scimitar syndrome. The patient, a 58-year-old male, was diagnosed with scimitar syndrome at the age of 26 but had never experienced any symptoms. He underwent chemoradiotherapy for mid-pharynx carcinoma and achieved complete response. During follow-up, a nodule appeared in the lower lobe of the left lung. Since right heart catheterization revealed a pulmonary blood flow/systemic blood flow ratio (Qp/Qs) ratio of 2.6, intra-cardiac blood flow was diverted prior to pulmonary resection. Stanford type A acute aortic dissection occurred intra-operatively, and total aortic arch replacement was performed. Three months later, partial pulmonary resection was performed with extracorporeal membrane oxygenation (ECMO) on standby. As oxygenation was maintained by placing a blocker in the left lower lobe bronchus and ventilating the left upper lobe with high frequency jet ventilation, the operation was completed without using ECMO. The nodule was pathologically diagnosed as metastasis of mid-pharynx carcinoma. He did not develop heart failure and was discharged on post operated day 15.


Subject(s)
Aortic Dissection , Carcinoma , Lung Neoplasms , Scimitar Syndrome , Male , Humans , Middle Aged , Scimitar Syndrome/diagnostic imaging , Scimitar Syndrome/surgery , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/surgery , Thorax , Bronchi
18.
Development ; 150(18)2023 09 15.
Article in English | MEDLINE | ID: mdl-37665168

ABSTRACT

Chicken embryos are a powerful and widely used animal model in developmental biology studies. Since the development of CRISPR technology, gene-edited chickens have been generated by transferring primordial germ cells (PGCs) into recipients after genetic modifications. However, low inheritance caused by competition between host germ cells and the transferred cells is a common complication and greatly reduces production efficiency. Here, we generated a gene-edited chicken, in which germ cells can be ablated in a drug-dependent manner, as recipients for gene-edited PGC transfer. We used the nitroreductase/metronidazole (NTR/Mtz) system for cell ablation, in which nitroreductase produces cytotoxic alkylating agents from administered metronidazole, causing cell apoptosis. The chicken Vasa homolog (CVH) gene locus was used to drive the expression of the nitroreductase gene in a germ cell-specific manner. In addition, a fluorescent protein gene, mCherry, was also placed in the CVH locus to visualize the PGCs. We named this system 'germ cell-specific autonomous removal induction' (gSAMURAI). gSAMURAI chickens will be an ideal recipient to produce offspring derived from transplanted exogenous germ cells.


Subject(s)
Chickens , Metronidazole , Chick Embryo , Animals , Chickens/genetics , Germ Cells/metabolism , Nitroreductases/metabolism
19.
Arch Microbiol ; 205(9): 310, 2023 Aug 18.
Article in English | MEDLINE | ID: mdl-37596383

ABSTRACT

A salt-tolerant exo-ß-1,3-glucosidase (BGL_MK86) was cloned from the xerophilic mold Aspergillus chevalieri MK86 and heterologously expressed in A. oryzae. Phylogenetic analysis suggests that BGL_MK86 belongs to glycoside hydrolase family 5 (aryl-phospho-ß-D-glucosidase, BglC), and exhibits D-glucose tolerance. Recombinant BGL_MK86 (rBGL_MK86) exhibited 100-fold higher expression than native BGL_MK86. rBGL_MK86 was active over a wide range of NaCl concentrations [0%-18% (w/v)] and showed increased substrate affinity for p-nitrophenyl-ß-D-glucopyranoside (pNPBG) and turnover number (kcat) in the presence of NaCl. The enzyme was stable over a broad pH range (5.5-9.5). The optimum reaction pH and temperature for hydrolysis of pNPBG were 5.5 and 45 °C, respectively. rBGL_MK86 acted on the ß-1,3-linked glucose dimer laminaribiose, but not ß-1,4-linked or ß-1,6-linked glucose dimers (cellobiose or gentiobiose). It showed tenfold higher activity toward laminarin (a linear polymer of ß-1,3 glucan) from Laminaria digitata than laminarin (ß-1,3/ß-1,6 glucan) from Eisenia bicyclis, likely due to its inability to act on ß-1,6-linked glucose residues. The ß-glucosidase retained hydrolytic activity toward crude laminarin preparations from marine biomass in moderately high salt concentrations. These properties indicate wide potential applications of this enzyme in saccharification of salt-bearing marine biomass.


Subject(s)
Sodium Chloride , beta-Glucosidase , beta-Glucosidase/genetics , Biomass , Hydrolysis , Phylogeny , Glucans , Glucose
20.
Cells Dev ; 176: 203874, 2023 12.
Article in English | MEDLINE | ID: mdl-37453484

ABSTRACT

Understanding the mechanism of stem cell maintenance underlies the establishment of long-term and mass culture methods for stem cells that are fundamental for clinical and agricultural applications. In this study, we use chicken primordial germ cell (PGC) as a model to elucidate the molecular mechanisms underlying stem cell maintenance. The PGC is a useful experimental model because it is readily gene-manipulatable and easy to test gene function in vivo using transplantation. Previous studies to establish a long-term culture system have shown that secreted factors such as FGF2 are required to maintain the self-renewal capability of PGC. On the other hand, we know little about intracellular regulators responsible for PGC maintenance. Among representative stem cell factors, we focus on RNA-binding factors LIN28A and LIN28B as possible central regulators for the gene regulatory network essential to PGC maintenance. By taking advantage of the CRISPR/Cas9-mediated gene editing and a clonal culture technique, we find that both LIN28A and LIN28B regulate the proliferation of PGC in vitro. We further showed that colonization efficiency of grafted PGC at the genital ridges, rudiments for the gonads, of chicken embryos were significantly decreased by knockout (KO) of LIN28A or LIN28B. Of note, overexpression of human LIN28 in LIN28-KO PGC was sufficient to restore the low colonization rates, suggesting that LIN28 plays a key role in PGC colonization at the gonads. Transcriptomic analyses of LIN28-KO PGC reveal that several genes related to mesenchymal traits are upregulated, including EGR1, a transcription factor that promotes the differentiation of mesodermal tissues. Finally, we show that the forced expression of human EGR1 deteriorates replication activity and colonization efficiency of PGCs. Taken together, this work demonstrates that LIN28 maintains self-renewal of PGC by suppressing the expression of differentiation genes including EGR1.


Subject(s)
Chickens , RNA-Binding Proteins , Animals , Chick Embryo/cytology , Chick Embryo/metabolism , Humans , Cell Differentiation , Chickens/genetics , Germ Cells/metabolism , Gonads/metabolism , Transcription Factors/genetics , RNA-Binding Proteins/metabolism
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