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1.
Nature ; 600(7888): 319-323, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34819663

RESUMO

Lung cancer is one of the most aggressive tumour types. Targeted therapies stratified by oncogenic drivers have substantially improved therapeutic outcomes in patients with non-small-cell lung cancer (NSCLC)1. However, such oncogenic drivers are not found in 25-40% of cases of lung adenocarcinoma, the most common histological subtype of NSCLC2. Here we identify a novel fusion transcript of CLIP1 and LTK using whole-transcriptome sequencing in a multi-institutional genome screening platform (LC-SCRUM-Asia, UMIN000036871). The CLIP1-LTK fusion was present in 0.4% of NSCLCs and was mutually exclusive with other known oncogenic drivers. We show that kinase activity of the CLIP1-LTK fusion protein is constitutively activated and has transformation potential. Treatment of Ba/F3 cells expressing CLIP1-LTK with lorlatinib, an ALK inhibitor, inhibited CLIP1-LTK kinase activity, suppressed proliferation and induced apoptosis. One patient with NSCLC harbouring the CLIP1-LTK fusion showed a good clinical response to lorlatinib treatment. To our knowledge, this is the first description of LTK alterations with oncogenic activity in cancers. These results identify the CLIP1-LTK fusion as a target in NSCLC that could be treated with lorlatinib.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Transformação Celular Neoplásica/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Proteínas Associadas aos Microtúbulos/genética , Proteínas de Neoplasias/genética , Proteínas de Fusão Oncogênica/genética , Receptores Proteína Tirosina Quinases/genética , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Aminopiridinas/farmacologia , Aminopiridinas/uso terapêutico , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Linhagem Celular Tumoral , Transformação Celular Neoplásica/efeitos dos fármacos , Cromossomos Humanos Par 12/genética , Cromossomos Humanos Par 15/genética , Humanos , Lactamas/farmacologia , Lactamas/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Camundongos , Camundongos Nus , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Proc Natl Acad Sci U S A ; 119(32): e2113795119, 2022 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-35917346

RESUMO

KIF1A is a kinesin superfamily motor protein that transports synaptic vesicle precursors in axons. Cargo binding stimulates the dimerization of KIF1A molecules to induce processive movement along microtubules. Mutations in human Kif1a lead to a group of neurodegenerative diseases called KIF1A-associated neuronal disorder (KAND). KAND mutations are mostly de novo and autosomal dominant; however, it is unknown if the function of wild-type KIF1A motors is inhibited by heterodimerization with mutated KIF1A. Here, we have established Caenorhabditis elegans models for KAND using CRISPR-Cas9 technology and analyzed the effects of human KIF1A mutation on axonal transport. In our C. elegans models, both heterozygotes and homozygotes exhibited reduced axonal transport. Suppressor screening using the disease model identified a mutation that recovers the motor activity of mutated human KIF1A. In addition, we developed in vitro assays to analyze the motility of heterodimeric motors composed of wild-type and mutant KIF1A. We find that mutant KIF1A significantly impaired the motility of heterodimeric motors. Our data provide insight into the molecular mechanism underlying the dominant nature of de novo KAND mutations.


Assuntos
Transporte Axonal , Caenorhabditis elegans , Cinesinas , Doenças Neurodegenerativas , Vesículas Sinápticas , Animais , Transporte Axonal/genética , Caenorhabditis elegans/genética , Modelos Animais de Doenças , Genes Dominantes , Humanos , Cinesinas/genética , Atividade Motora/genética , Mutação , Doenças Neurodegenerativas/genética , Vesículas Sinápticas/genética , Vesículas Sinápticas/metabolismo
3.
Gan To Kagaku Ryoho ; 50(1): 110-112, 2023 Jan.
Artigo em Japonês | MEDLINE | ID: mdl-36760003

RESUMO

The patient underwent partial sigmoid colon resection for sigmoid colon cancer with hyper CEA blood(1,110.6 ng/mL) and concurrent liver metastases mostly in the right lobe of the liver, followed by systemic chemotherapy(SOX plus BEV). Seven courses of chemotherapy resulted in PR on imaging, and CEA was reduced to 5.0 ng/mL, which was within reference values. As he continued chemotherapy, frequent hematologic toxicities and adverse events forced frequent dose reductions and changes in the chemotherapy schedule. About 2 years after surgery(19 courses of SOX plus BEV), the liver metastases became slightly enlarged on imaging, and the CEA was also increasing. The patient did not wish to undergo systemic chemotherapy and requested hepatic arterial infusion chemotherapy(HAIC), which has relatively few side effects and adverse events. HAIC with pyrimidine fluoride alone is ongoing for 22 courses, and tumor markers have decreased again with PR on imaging. Performance status has been good without hematologic toxicity or adverse events for approximately 1 year during the course of HAIC. HAIC is a weakly recommended therapy in the colorectal cancer treatment guidelines, but it is considered one of the most effective therapies with relatively few side effects.


Assuntos
Neoplasias Colorretais , Neoplasias Hepáticas , Neoplasias do Colo Sigmoide , Masculino , Humanos , Fluoruracila , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Infusões Intra-Arteriais , Neoplasias do Colo Sigmoide/tratamento farmacológico , Neoplasias do Colo Sigmoide/cirurgia , Neoplasias do Colo Sigmoide/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/secundário , Artéria Hepática/patologia , Neoplasias Colorretais/cirurgia
4.
Int J Mol Sci ; 23(21)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36362023

RESUMO

Tumor-associated macrophages (TAMs) and abnormalities in cancer cells affect cancer progression and response to therapy. TAMs are a major component of the tumor microenvironment (TME) in breast cancer, with their invasion affecting clinical outcomes. Programmed death-ligand 1 (PD-L1), a target of immune checkpoint inhibitors, acts as a suppressive signal for the surrounding immune system; however, its expression and effect on TAMs and the clinical outcome in breast cancer are unknown. In this study, we used high-throughput multiple immunohistochemistry to spatially and quantitatively analyze TAMs. We subjected 81 breast cancer specimens to immunostaining for CD68, CD163, PD-1, PD-L1, CD20, and pan-CK. In both stromal and intratumoral areas, the triple-negative subtype had significantly more CD68/CD163, CD68/PD-L1, and CD163/PD-L1 double-positive cells than the estrogen receptor (ER)/progesterone receptor (PR) subtype. Interestingly, a higher number of CD68+/PD-L1+/CK-/CD163- TAMs in the intratumoral area was correlated with a favorable recurrence rate (p = 0.048). These findings indicated that the specific subpopulation and localization of TAMs in the TME affect clinical outcomes in breast cancer.


Assuntos
Antígeno B7-H1 , Neoplasias de Mama Triplo Negativas , Macrófagos Associados a Tumor , Humanos , Antígeno B7-H1/metabolismo , Macrófagos/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Microambiente Tumoral , Macrófagos Associados a Tumor/citologia , Biomarcadores Tumorais
5.
Biophys J ; 120(9): 1605-1614, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33617835

RESUMO

Synaptic cargo transport by kinesin and dynein in hippocampal neurons was investigated by noninvasively measuring the transport force based on nonequilibrium statistical mechanics. Although direct physical measurements such as force measurement using optical tweezers are difficult in an intracellular environment, the noninvasive estimations enabled enumerating force-producing units (FPUs) carrying a cargo comprising the motor proteins generating force. The number of FPUs served as a barometer for stable and long-distance transport by multiple motors, which was then used to quantify the extent of damage to axonal transport by dynarrestin, a dynein inhibitor. We found that dynarrestin decreased the FPU for retrograde transport more than for anterograde transport. This result indicates the applicability of the noninvasive force measurements. In the future, these measurements may be used to quantify damage to axonal transport resulting from neuronal diseases, including Alzheimer's, Parkinson's, and Huntington's diseases.


Assuntos
Dineínas , Cinesinas , Transporte Axonal , Dineínas/metabolismo , Cinesinas/metabolismo , Miosinas , Pinças Ópticas
6.
Medicina (Kaunas) ; 57(9)2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34577875

RESUMO

Background and objectives: Our department has been performing primary breast reconstruction for breast cancer surgery, incorporating a transverse rectus abdominis myocutaneous flap (TRAM)/vertical rectus abdominis myocutaneous flap (VRAM) since 1998 and a deep inferior epigastric artery perforator flap (DIEP) since 2008. Currently, most gastrointestinal operations in abdominal surgery are performed laparoscopically or are robot-assisted. Cases in which abdominal surgery was performed after breast reconstruction using an abdominal flap were reviewed. Method: A total of 119 cases of primary breast reconstruction using an abdominal flap performed in our department were reviewed. Result: The reconstructive techniques were DIEP in 69 cases and TRAM/VRAM in 50 cases. After breast surgery, seven abdominal operations were performed in six cases. In DIEP cases, one robotic surgery was performed for uterine cancer, and one laparoscopic surgery was performed for ovarian tumor. In TRAM/VRAM cases, two laparoscopic cholecystectomies, one laparoscopic total gastrectomy, one laparoscopic ileus reduction, and one open total hysterectomy oophorectomy were performed. Six surgeries were completed by laparoscopy or robotic assistance. Conclusion: The survival rate after breast cancer surgery is improving, and the choice of breast reconstruction procedure should take into account the possibility of performing a prophylactic resection of the ovaries due to the genetic background and possibly postoperative abdominal surgery due to other diseases. However, in cases in which laparoscopic surgery was attempted after breast reconstruction using an abdominal flap, the laparoscopic surgery could be completed in all cases.


Assuntos
Neoplasias da Mama , Laparoscopia , Mamoplastia , Retalho Perfurante , Neoplasias da Mama/cirurgia , Feminino , Humanos , Ovariectomia , Complicações Pós-Operatórias , Reto do Abdome/cirurgia , Estudos Retrospectivos
7.
Gan To Kagaku Ryoho ; 48(13): 1652-1654, 2021 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-35046286

RESUMO

A 60-year-old woman underwent laparoscopic total gastrectomy for gastric cancer with a good postoperative course. At the age of 45, she had underwent skin-sparing total mastectomy, sentinel node biopsy, and right rectus abdominis flap reconstruction for left breast cancer. Since there is a certain risk of abdominal wall hernia after the abdominal flap reconstruction, laparoscopic surgery with less abdominal wall damage might be useful. Although the umbilicus is hollowed out and sutured to a small hole in the cranial skin after abdominal flap reconstruction, there seems to be no problem in using the umbilicus for the port. The abdominal wall is scarred after the abdominal flap reconstruction, but normal insufflation pressure was sufficient to perform the operation in our case. Additionally, we must be careful not to damage the flap pedicle, and it would be useful to check its location by ultrasonography before starting the operation.


Assuntos
Neoplasias da Mama , Laparoscopia , Mamoplastia , Neoplasias Gástricas , Neoplasias da Mama/cirurgia , Feminino , Gastrectomia , Humanos , Mastectomia , Pessoa de Meia-Idade , Reto do Abdome/transplante , Neoplasias Gástricas/cirurgia
8.
Gan To Kagaku Ryoho ; 48(13): 1598-1600, 2021 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-35046268

RESUMO

A 54-year-old man underwent laparoscopic distal gastrectomy with D2 lymph node dissection and ante-colic Roux-en-Y reconstruction for gastric cancer. The histopathological diagnosis was pT2N3aM0, pStage ⅢA, HER2 negative. After 8 courses of S-1 plus oxaliplatin as adjuvant chemotherapy, he was diagnosed as peritoneal dissemination and treated with ramucirumab(RAM)plus paclitaxel(PTX). On the 12th day of course 10, he visited to our hospital with abdominal pain. CT showed free air and massive ascites. Emergent surgery was performed under the diagnosis of gastrointestinal perforation. A small intestinal perforation in front of the jejunal limb near gastric-jejunal anastomosis was identified and there was no peritoneal dissemination. We performed partial resection of remnant stomach and jejunal limb by linear stapler and reconstruction by end to side gastric-jejunal anastomosis. Because the gastric and intestinal wall were quite fragile and RAM impaired wound healing as adverse event, we feared about leakage, but he had no major postoperative complications and discharged on the 33th day after surgery. After 24 courses of nivolumab as third-line chemotherapy, the peritoneal dissemination disappeared. He has been alive without recurrence for about 1 year since then.


Assuntos
Perfuração Intestinal , Neoplasias Gástricas , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Gastrectomia , Humanos , Perfuração Intestinal/induzido quimicamente , Perfuração Intestinal/cirurgia , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/cirurgia , Ramucirumab
9.
Gan To Kagaku Ryoho ; 47(13): 1780-1782, 2020 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-33468827

RESUMO

A 77-year-old man was given a diagnosis of pT4aN0M1a(PUL2), stage Ⅳ, RAS mutant type, after the operation for advanced ascending colon cancer. He was administered mFOLFOX6 plus Bmab as first-line chemotherapy. He showed consciousness disturbance on the 2nd day during the 6 cycles. Because of head computed tomography and magnetic resonance imaging showing no abnormal findings, we diagnosed convulsive seizure. His consciousness level gradually improved after intravenous infusion. He showed consciousness disturbance on the 2nd day during the 7 cycles again. Because blood ammonia level were high at 400µg/dL, he was diagnosed as hyperammonemic encephalopathy. His consciousness level rapidly recovered after branched chain amino acid(BCAA)infusion. SOX plus Bmab therapy was started as a post-treatment, he developed hyperammonemia(NH3 288µg/dL)again, on the 4th day during the 3 cycles. After taking of oral administration of BCAA and lactulose, the recurrence of hyperammonemic encephalopathy was not found. Therefore, 3 cycles of SOX plus Bmab therapy and 12 cycles of IRIS plus Bmab therapy were administered.


Assuntos
Encefalopatias , Neoplasias do Colo , Hiperamonemia , Neoplasias Retais , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias do Colo/tratamento farmacológico , Humanos , Hiperamonemia/induzido quimicamente , Hiperamonemia/tratamento farmacológico , Masculino , Recidiva Local de Neoplasia , Neoplasias Retais/tratamento farmacológico
10.
Gan To Kagaku Ryoho ; 46(13): 2482-2484, 2019 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-32156972

RESUMO

A 33-year-old man was diagnosed with bowel obstruction due to advanced sigmoid colon cancer and underwent an emergency laparotomy. The sigmoid colon cancer turned out to be unresectable because of firm invasion to the retroperitoneum with severe adhesions and diffuse dissemination. Therefore, unplanned jejunostomy was performed, which was complicated by high-output stoma and short bowel syndrome. His condition was stable enough to receive chemotherapy via parenteral nutrition and parenteral electrolyte solution infusion added to the diet. mFOLFOX6 plus cetuximab therapy was started 4 weeks postoperatively. Although oxaliplatin was discontinued because of worsening numbness, he was sustained without cancer progression by receiving chemotherapy for a year. Chemotherapy was interrupted by a Candida fungemia 13months postoperatively, and he died 4 months later. Patients with jejunostomy may have difficulty absorbing enough water and nutrients in the intestine; therefore, they are at risk of dehydration and electrolyte depletions due to high stomal output, and malnutrition due to the short bowel. These complications may prevent colorectal cancer patients with jejunostomy to be indicated for chemotherapy.


Assuntos
Neoplasias Peritoneais/secundário , Síndrome do Intestino Curto , Neoplasias do Colo Sigmoide , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cetuximab , Fluoruracila , Humanos , Jejunostomia , Leucovorina , Masculino , Compostos Organoplatínicos , Neoplasias Peritoneais/tratamento farmacológico , Síndrome do Intestino Curto/complicações , Neoplasias do Colo Sigmoide/tratamento farmacológico
11.
Phys Chem Chem Phys ; 20(5): 3403-3410, 2018 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-29349444

RESUMO

Kinesin superfamily protein UNC-104, a member of the kinesin-3 family, transports synaptic vesicle precursors (SVPs). In this study, the number of active UNC-104 molecules hauling a single SVP in axons in the worm Caenorhabditis elegans was counted by applying a newly developed non-invasive force measurement technique. The distribution of the force acting on a SVP transported by UNC-104 was spread out over several clusters, implying the presence of several force-producing units (FPUs). We then compared the number of FPUs in the wild-type worms with that in arl-8 gene-deletion mutant worms. ARL-8 is a SVP-bound arf-like small guanosine triphosphatase, and is known to promote unlocking of the autoinhibition of the motor, which is critical for avoiding unnecessary consumption of adenosine triphosphate when the motor does not bind to a SVP. There were fewer FPUs in the arl-8 mutant worms. This finding indicates that a lack of ARL-8 decreased the number of active UNC-104 motors, which then led to a decrease in the number of motors responsible for SVP transport.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Cinesinas/metabolismo , Vesículas Sinápticas/metabolismo , Animais , Transporte Axonal , Axônios/metabolismo , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , GTP Fosfo-Hidrolases/química , GTP Fosfo-Hidrolases/genética , Cinesinas/química , Microscopia de Fluorescência , Mutagênese , Vesículas Sinápticas/química
12.
Gan To Kagaku Ryoho ; 45(13): 1925-1927, 2018 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-30692399

RESUMO

The is a case involving a 55-year-old man with advanced rectal cancer(type 3). MRI showed urinary tract and regional lymph node metastases without distant metastasis. The tumor was reduced(PR)after neoadjuvant chemotherapy(mFOL FOX6 plus Bmab, 4 courses). The patient underwent an abdominoperineal resection. Because infiltration of the tumor into the lower urinary tract was deep, it was also resected and repaired. The clip was placed to mark the repaired region. Pathological examination revealed that excision stump at the anterior wall of the urethra was cancer positive without lymph node metastasis. He was then administered chemotherapy(mFOLFOX6 4 courses)and irradiated 60 Gy in both sides of the inguinal lymph node to prevent metastasis to the pelvicdomain. One year and 6 months postoperatively, as the left inguinal lymph node swelled at 3.7 cm irregularly, he further received chemotherapy(FOLFIRI 8 courses). The size of the lymph node became normal with a good response to FOLFIRI. Six years postoperatively, he remains alive and well with no evidence of recurrence.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Retais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Intervalo Livre de Doença , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Recidiva Local de Neoplasia , Neoplasias Retais/tratamento farmacológico , Neoplasias Retais/cirurgia
13.
Int J Qual Health Care ; 28(3): 281-7, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26921258

RESUMO

OBJECTIVE: The aim of this study was to examine the association between accessibility to cardiovascular emergency centers and cardiovascular mortality in Japan. DESIGN: A semi-ecological study. SETTING: Three databases were generated: accessibility to emergency cardiovascular centers, population records and death records. MAIN OUTCOME MEASURES: The standardized mortality ratio (SMR) for cardiovascular disease was adjusted by age and sex. Accessibility was represented by transfer time, number of cardiovascular emergency hospitals, and the proportion of habitable areas. Combinations of the three were divided into Categories 1-8 from the worst to the best, and the association with SMR was analyzed. RESULTS: There were 1998 cardiovascular emergency hospitals. The median of crude mortality was 0.16%. The median SMR of the reference Category 8 (transfer time <30 min and habitable area ≥50% with cardiovascular emergency hospitals) was 0.96, but that of the low accessibility Category 1 (transfer time ≥30 min and habitable area <50% without cardiovascular emergency hospitals) was 1.10. The SMR of accessibility Category 1 : Category 8 was 1.18 (95% confidence interval: 1.14-1.21). CONCLUSIONS: Decreased accessibility to cardiovascular emergency hospitals was associated with increased SMR. Areas with less accessibility and higher cardiovascular mortality were characterized by geographical variability in Japan.


Assuntos
Institutos de Cardiologia/estatística & dados numéricos , Doenças Cardiovasculares/mortalidade , Serviço Hospitalar de Emergência/estatística & dados numéricos , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Adolescente , Adulto , Idoso , Feminino , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/terapia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Transferência de Pacientes/organização & administração , Transferência de Pacientes/estatística & dados numéricos , Características de Residência/estatística & dados numéricos , Fatores de Risco , Fatores de Tempo , Adulto Jovem
14.
Phys Rev Lett ; 114(24): 248101, 2015 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-26197015

RESUMO

The giant acceleration (GA) of diffusion is a universal phenomenon predicted by the theoretical analysis given by Reimann et al. [Phys. Rev. Lett. 87, 010602 (2001)]. Here we apply the theory of the GA of diffusion to a single-molecule experiment on a rotary motor protein, F(1), which is a component of F(o)F(1) adenosine triphosphate synthase. We discuss the energetic properties of F(1) and identify a high energy barrier of the rotary potential to be 20k(B)T, with the condition that the adenosine diphosphates are tightly bound to the F(1) catalytic sites. To conclude, the GA of diffusion is useful for measuring energy barriers in nonequilibrium and single-molecule experiments.


Assuntos
Modelos Químicos , ATPases Translocadoras de Prótons/química , Difusão , Hidrólise , Cinética , Termodinâmica
15.
BMC Pediatr ; 15: 29, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25886476

RESUMO

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is now a candidate therapy for children with acute respiratory failure. CASE PRESENTATION: We report our experience of using central ECMO therapy for acute respiratory distress syndrome followed by seizure in a 15-month-old girl with a severe epileptic disorder. Her respiratory distress was refractory to standard medical treatment and mechanical ventilatory support. Her condition was complicated by development of a pneumothorax. The patient was successfully weaned off ECMO and discharged without deterioration of her neurological status. CONCLUSION: The successful outcome in this case resulted from the central ECMO, which enabled "lung rest" and adequate cerebral blood flow. In skilled ECMO facilities, early implementation of ECMO would give some advantages to patients such as the one presented here. Given the invasiveness and the ease of the procedure, introduction of dual-lumen catheters adequately sized for pediatric patients in Japan is required.


Assuntos
Epilepsia/complicações , Oxigenação por Membrana Extracorpórea , Insuficiência Respiratória/complicações , Insuficiência Respiratória/terapia , Feminino , Ventilação de Alta Frequência/efeitos adversos , Humanos , Lactente , Pneumotórax/etiologia
16.
Eur Biophys J ; 43(8-9): 415-22, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25012687

RESUMO

Vacuolar-type H(+)-pumping ATPases (V-ATPases) perform remarkably diverse functions in eukaryotic organisms. They are present in the membranes of many organelles and regulate the pH of several intracellular compartments. A family of V-ATPases is also present in the plasma membranes of some bacteria. Such V-ATPases function as ATP-synthases. Each V-ATPase is composed of a water-soluble domain (V1) and a membrane-embedded domain (Vo). The ATP-driven rotary unit, V[Formula: see text], is composed of A, B, D, and F subunits. The rotary shaft (the DF subcomplex) rotates in the central cavity of the A3B3-ring (the catalytic hexamer ring). The D-subunit, which has a coiled-coil domain, penetrates into the ring, while the F-subunit is a globular-shaped domain protruding from the ring. The minimal ATP-driven rotary unit of V[Formula: see text] is comprised of the A3B3D subunits, and we therefore investigated how the absence of the globular-shaped F-subunit affects the rotary torque generation of V[Formula: see text]. Using a single-molecule technique, we observed the motion of the rotary motors. To obtain the torque values, we then analyzed the measured motion trajectories based on the fluctuation theorem, which states that the law of entropy production in non-equilibrium conditions and has been suggested as a novel and effective method for measuring torque. The measured torque of A3B3D was half that of the wild-type V1, and full torque was recovered in the mutant V1, in which the F-subunit was genetically fused with the D-subunit, indicating that the globular-shaped F-subunit reinforces torque generation in V1.


Assuntos
Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Torque , ATPases Vacuolares Próton-Translocadoras/química , ATPases Vacuolares Próton-Translocadoras/metabolismo , Evolução Molecular , Modelos Moleculares , Estrutura Terciária de Proteína , Rotação
17.
Diagnostics (Basel) ; 14(15)2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39125527

RESUMO

BACKGROUND: High breast density found using mammographs (MGs) reduces positivity rates and is considered a risk factor for breast cancer. Research on the relationship between Volpara density grade (VDG) and compressed breast thickness (CBT) in the Japanese population is still lacking. Moreover, little attention has been paid to pseudo-dense breasts with CBT < 30 mm among high-density breasts. We investigated VDG, CBT, and apparent high breast density in patients with breast cancer. METHODS: Women who underwent MG and breast cancer surgery at our institution were included. VDG and CBT were measured. VDG was divided into a non-dense group (NDG) and a dense group (DG). RESULTS: This study included 419 patients. VDG was negatively correlated with CBT. The DG included younger patients with lower body mass index (BMI) and thinner CBT. In the DG, patients with CBT < 30 mm had lower BMI and higher VDG; however, no significant difference was noted in the positivity rate of the two groups. CONCLUSIONS: Younger women tend to have higher breast density, resulting in thinner CBT, which may pose challenges in detecting breast cancer on MGs. However, there was no significant difference in the breast cancer detection rate between CBT < 30 mm and CBT ≥ 30 mm.

18.
J Imaging ; 10(9)2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39330431

RESUMO

Although several studies have been conducted on artificial intelligence (AI) use in mammography (MG), there is still a paucity of research on the diagnosis of metachronous bilateral breast cancer (BC), which is typically more challenging to diagnose. This study aimed to determine whether AI could enhance BC detection, achieving earlier or more accurate diagnoses than radiologists in cases of metachronous contralateral BC. We included patients who underwent unilateral BC surgery and subsequently developed contralateral BC. This retrospective study evaluated the AI-supported MG diagnostic system called FxMammo™. We evaluated the capability of FxMammo™ (FathomX Pte Ltd., Singapore) to diagnose BC more accurately or earlier than radiologists' assessments. This evaluation was supplemented by reviewing MG readings made by radiologists. Out of 1101 patients who underwent surgery, 10 who had initially undergone a partial mastectomy and later developed contralateral BC were analyzed. The AI system identified malignancies in six cases (60%), while radiologists identified five cases (50%). Notably, two cases (20%) were diagnosed solely by the AI system. Additionally, for these cases, the AI system had identified malignancies a year before the conventional diagnosis. This study highlights the AI system's effectiveness in diagnosing metachronous contralateral BC via MG. In some cases, the AI system consistently diagnosed cancer earlier than radiological assessments.

19.
Biophys J ; 105(10): 2385-91, 2013 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-24268150

RESUMO

Protein conformational fluctuations modulate the catalytic powers of enzymes. The frequency of conformational fluctuations may modulate the catalytic rate at individual reaction steps. In this study, we modulated the rotary fluctuation frequency of F1-ATPase (F1) by attaching probes with different viscous drag coefficients at the rotary shaft of F1. Individual rotation pauses of F1 between rotary steps correspond to the waiting state of a certain elementary reaction step of ATP hydrolysis. This allows us to investigate the impact of the frequency modulation of the rotary fluctuation on the rate of the individual reaction steps by measuring the duration of rotation pauses. Although phosphate release was significantly decelerated, the ATP-binding and hydrolysis steps were less sensitive or insensitive to the viscous drag coefficient of the probe. Brownian dynamics simulation based on a model similar to the Sumi-Marcus theory reproduced the experimental results, providing a theoretical framework for the role of rotational fluctuation in F1 rate enhancement.


Assuntos
Biocatálise , ATPases Translocadoras de Prótons/metabolismo , Rotação , Trifosfato de Adenosina/metabolismo , Fenômenos Biomecânicos , Fricção , Hidrólise , Cinética , Modelos Biológicos , Sondas Moleculares/metabolismo , Fosfatos/metabolismo , Viscosidade
20.
Neurosci Res ; 197: 25-30, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37734449

RESUMO

Kinesin motor proteins play crucial roles in anterograde transport of cargo vesicles in neurons, moving them along axons from the cell body towards the synaptic region. Not only the transport force and velocity of single motor protein, but also the number of kinesin molecules involved in transporting a specific cargo, is pivotal for synapse formation. This collective transport by multiple kinesins ensures stable and efficient cargo transport in neurons. Abnormal increases or decreases in the number of engaged kinesin molecules per cargo could potentially act as biomarkers for neurodegenerative diseases such as Alzheimer's, Parkinson's, amyotrophic lateral sclerosis (ALS), spastic paraplegia, polydactyly syndrome, and virus transport disorders. We review here a model constructed using physical measurements to quantify the number of kinesin molecules associated with their cargo, which could shed light on the molecular mechanisms of neurodegenerative diseases related to axonal transport.


Assuntos
Esclerose Lateral Amiotrófica , Cinesinas , Humanos , Cinesinas/metabolismo , Transporte Axonal/fisiologia , Axônios/metabolismo , Dineínas/metabolismo , Esclerose Lateral Amiotrófica/metabolismo
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