Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Chem Theory Comput ; 19(14): 4678-4688, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37097918

RESUMO

High-speed (HS) atomic force microscopy (AFM) can be used to observe structural dynamics of biomolecules under near-physiological conditions. In the AFM measurement, the probe tip scans an area of interest and acquires height data pixel by pixel so that the obtained AFM image contains a measurement time difference. In this study, to integrate molecular dynamics simulations with asynchronous HS-AFM movie data, we developed a particle smoother (PS) method for Bayesian data assimilation, one of the machine learning approaches, by extending the previous particle filter method. With a twin experiment with an asynchronous pseudo HS-AFM movie of a nucleosome, we found that the PS method with the pixel-by-pixel data acquisition reproduced the dynamic behavior of a nucleosome better than the previous particle filter method that ignored the data asynchronicity. We examined several frequencies of particle resampling in the PS method, and found that resampling once per one frame was optimal for reproducing the dynamic behavior. Thus, we found that the PS method with an appropriate resampling frequency is a powerful method for estimating the dynamic behavior of a target molecule from HS-AFM data with low spatiotemporal resolution.

2.
Arthroplast Today ; 15: 108-114, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35774886

RESUMO

Background: Fit-and-fill stems are known to have excellent outcomes; however, severe stress shielding has been reported in Japanese populations. Short fit-and-fill stems were modified for Asians; however, there have been no previous reports of its outcome. In this study, we compared the 5-year (mean 68-month) outcomes of 2 fit-and-fill stems with different lengths (standard or short). Material and methods: We reviewed 100 total hip arthroplasties in each standard- or short-stem group. Radiographs were evaluated for femoral morphology, stress shielding, bone remodeling, and fixation. Clinical evaluation was performed using the Japanese Orthopaedic Association (JOA) scores. Results: There was no difference in the degree of stress shielding between the 2 groups. Significant differences were observed in radiolucent lines in zone 4 (P = .005) and cortical hypertrophy in zone 3 (P < .0001) and 5 (P = .048) between the 2 groups. The canal flare index (P < .0003), cortical index (P < .0003), height (P < .0345), and stem size (P < .0081) individually affected stress shielding in the standard-stem group. In contrast, the cortical index (P < .0107) was the only relative factor in the short-stem group. All stems were judged to have bone ingrowth. The JOA score improved significantly (P < .0001); however, there were no significant differences between the 2 groups. Conclusion: The outcomes of both standard and short fit-and-fill stems were favorable. There were no significant differences in the stress shielding or JOA scores. Although there were a few differences in bone remodeling and factors affecting stress shielding, stem length reduction has been achieved without adverse effects with the Japanese femur.

3.
SICOT J ; 8: 24, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35699460

RESUMO

INTRODUCTION: Both hemiarthroplasty (HA) and total hip arthroplasty (THA) are widely accepted surgical procedures for hip replacement following displaced femoral neck fractures. However, in cases involving an intact joint line before surgery, the choice between HA and THA remains debatable. This study investigated the prevalence of acetabular cartilage and labral abnormalities in elderly patients with femoral neck fractures. METHODS: Thirty-seven patients underwent hip arthroplasty for femoral neck fractures between April 2020 and February 2021. After excluding 4 patients, 33 patients (6 men and 27 women; mean age = 82.2 [range = 67-98] years) with fractures in 12 left and 21 right hips were included. After femoral head removal during arthroplasty, the acetabulum was macroscopically examined for the presence of cartilage and labral lesions. Acetabular cartilage abnormalities were classified as either overall degeneration or partial damage according to the cartilage damage classification system. RESULTS: Acetabular cartilage abnormalities, including overall degeneration or partial damage, were found in all hips (100%). Out of the 33 hips, overall degeneration, partial damage, and labral abnormalities were detected in 32 (96.9%), 16 (48.4%), and 9 (27.2%) hips, respectively. DISCUSSION: In this study, most elderly patients with femoral neck fractures exhibited acetabular cartilage and labral abnormalities, which were already present at the time of surgery. Therefore, surgeons should carefully examine these abnormalities as they may impact postoperative outcomes such as pain and function.

4.
Trauma Case Rep ; 32: 100447, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33732859

RESUMO

Most surgical treatment options for metastatic acetabular lesions involve variants of total hip arthroplasty (THA). However, these are technically complex reconstructions performed in very frail patients, and previous reports indicate complications such as dislocation, deep infection, aseptic loosening, and intraoperative death. A 73-year-old man presented to the emergency department at our hospital with right hip pain following a fall. He had undergone nephrectomy for the treatment of right kidney cancer at the age of 68 years. Four years after the nephrectomy, multiple lung metastases, pelvic bone metastases, and right femoral head and neck bone metastases were found. A radiograph of the hip joint showed a pathological proximal femoral fracture with a radiolucent lesion of the acetabulum. THA with acetabular reconstruction using a Kerboull-type (KT) plate through the direct anterior approach (DAA) was performed. After removal of the femoral head, curettage of the metastatic acetabular dome lesion was carefully performed under fluoroscopic guidance. After the KT plate was placed, cementation of the metastatic acetabular dome lesion was performed, and an optimally sized polyethylene liner was fixed with cement. A cemented stem was inserted after confirming the hip joint stability. At the 14-month follow-up, he could walk steadily without any complications and his modified Harris hip score was 100. The DAA conserves soft tissue because it is an intermuscular approach. Accordingly, postoperative recovery is fast and thus associated with a low dislocation rate and effective pain reduction. The acetabulum with metastatic disease was reconstructed using a KT plate for hip joint stability. Bone with metastatic disease that appears adequate at the time of THA may become incompetent after a few years. THA with acetabular reconstruction using a KT plate through the DAA was an effective treatment for metastatic bone disease of the acetabulum combined with pathological proximal femoral neck fracture.

5.
Sci Rep ; 10(1): 18393, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33110182

RESUMO

High-speed atomic force microscopy (HS-AFM) is a scanning probe microscopy that can capture structural dynamics of biomolecules in real time at single molecule level near physiological condition. Albeit much improvement, while scanning one frame of HS-AFM movies, biomolecules often change their conformations largely. Thus, the obtained frame images can be hampered by the time-difference, the asynchronicity, in the data acquisition. Here, to resolve this data asynchronicity in the HS-AFM movie, we developed Kalman filter and smoother methods, some of the sequential Bayesian filtering approaches. The Kalman filter/smoother methods use alternative steps of a short time-propagation by a linear dynamical system and a correction by the likelihood of AFM data acquired pixel by pixel. We first tested the method using a toy model of a diffusing cone, showing that the Kalman smoother method outperforms to reproduce the ground-truth movie. We then applied the Kalman smoother to a synthetic movie for conformational change dynamics of a motor protein, i.e., dynein, confirming the superiority of the Kalman smoother. Finally, we applied the Kalman smoother to two real HS-AFM movies, FlhAC and centralspindlin, reducing distortion and noise in the AFM movies. The method is general and can be applied to any HS-AFM movies.

6.
Yakugaku Zasshi ; 140(9): 1175-1183, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32879249

RESUMO

The mock patches were prepared with novel acrylic polymers as adhesive layer where biphenyl-4-ylacetic acid (BAA) or 2-(2-fluorobiphenyl-4-yl) propanoic acid (FPA) was used as model active pharmaceutical ingredients (APIs). In addition, the mock patches were formulated with typical ester ingredients for transdermal dosage forms. The molecular state of the model APIs in the adhesive layer was observed by polarized microscope and microscopic Raman spectroscopy, which contains both conventional and low frequency (LF) region. Crystallization behavior would be depended on the interaction between API and polymers in the adhesive layer. In particular, LF Raman measurement was useful to discriminate API polymorphs. The pharmaceutical properties including dissolution and skin permeation of APIs were also evaluated for mock patches. The drug release and transdermal permeation were enhanced with the ester ingredients such as isopropyl myristate and diethyl sebacate due to their diffusion to the test solution or the skin stratum corneum as well as reducing the interaction between API and polymers. Further, the tack strength was not changed, but the peel strength was weakened by the additives. Thus, the adhesive properties were controllable by formulation with the additives. These findings could enable to evaluate the interaction between API and the polymers for adhesive layer and select the appropriate polymer and additives for used APIs when designing the drug products.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Polímeros , Adesivo Transdérmico , Adesividade , Administração Cutânea , Ácidos Decanoicos , Liberação Controlada de Fármacos , Miristatos , Fenilacetatos/administração & dosagem , Fenilacetatos/metabolismo , Propionatos/administração & dosagem , Propionatos/metabolismo , Absorção Cutânea , Solubilidade , Análise Espectral Raman
7.
Drug Metab Dispos ; 48(10): 934-943, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32665417

RESUMO

The PXB-mouse is potentially a useful in vivo model to predict human hepatic metabolism and clearance. Four model compounds, [14C]desloratadine, [3H]mianserin, cyproheptadine, and [3H]carbazeran, all reported with disproportionate human metabolites, were orally administered to PXB- or control SCID mice to elucidate the biotransformation of each of them. For [14C]desloratadine in PXB-mice, O-glucuronide of 3-hydroxydesloratadine was observed as the predominant metabolite in both the plasma and urine. Both 3-hydroxydesloratadine and its O-glucuronide were detected as major drug-related materials in the bile, whereas only 3-hydroxydesloratadine was detected in the feces, suggesting that a fraction of 3-hydroxydesloratadine in feces was derived from deconjugation of its O-glucuronide by gut microflora. This information can help understand the biliary clearance mechanism of a drug and may fill the gap in a human absorption, distribution, metabolism, and excretion study, in which the bile samples are typically not available. The metabolic profiles in PXB-mice were qualitatively similar to those reported in humans in a clinical study in which 3-hydroxydesloratadine and its O-glucuronide were major and disproportionate metabolites compared with rat, mouse, and monkey. In the control SCID mice, neither of the metabolites was detected in any matrix. Similarly, for the other three compounds, all human specific or disproportionate metabolites were detected at a high level in PXB-mice, but they were either minimally observed or not observed in the control mice. Data from these four compounds indicate that studies in PXB-mice can help predict the potential for the presence of human disproportionate metabolites (relative to preclinical species) prior to conducting clinical studies and understand the biliary clearance mechanism of a drug. SIGNIFICANCE STATEMENT: Studies in PXB-mice have successfully predicted the human major and disproportionate metabolites compared with preclinical safety species for desloratadine, mianserin, cyproheptadine, and carbazeran. In addition, biliary excretion data from PXB-mice can help illustrate the human biliary clearance mechanism of a drug.


Assuntos
Eliminação Hepatobiliar , Fígado/metabolismo , Animais , Bile/metabolismo , Biotransformação , Carbamatos/administração & dosagem , Carbamatos/farmacocinética , Ciproeptadina/administração & dosagem , Ciproeptadina/farmacocinética , Avaliação Pré-Clínica de Medicamentos/métodos , Hepatócitos/metabolismo , Hepatócitos/transplante , Humanos , Fígado/citologia , Loratadina/administração & dosagem , Loratadina/análogos & derivados , Loratadina/farmacocinética , Masculino , Mianserina/administração & dosagem , Mianserina/farmacocinética , Camundongos , Quimeras de Transplante/metabolismo
8.
Basic Clin Pharmacol Toxicol ; 122(6): 577-587, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29345044

RESUMO

TAK-063 is currently being developed to treat schizophrenia. In this study, we investigated the absorption, distribution, metabolism and excretion (ADME) properties of TAK-063 using several paradigms. Following oral administration of TAK-063 at 0.3 mg/kg, bioavailability of TAK-063 was 27.4% in rats and 49.5% in dogs with elimination half-lives of 3.1 hr in rats and 3.7 hr in dogs. TAK-063 is a highly permeable compound without P-glycoprotein (P-gp) or breast cancer resistance protein substrate liability and can be readily absorbed into systemic circulation via the intestine. TAK-063 can also cross the blood-brain barrier. TAK-063 was metabolized mainly by CYP2C8 and CYP3A4/5, while incubation with human liver microsomes produced the major human metabolite, M-I as well as several unknown minor metabolites. Metabolism of TAK-063 to M-I occurs through hydroxylation of the mono-substituted pyrazole moiety. In vitro, TAK-063 was observed to inhibit CYP2C8, CYP2C19 and P-gp with IC50 values of 8.4, 12 and 7.13 µM, respectively. TAK-063 was primarily excreted in the faeces in rats and dogs with M-I as a predominant component. The pre-clinical data from these ADME studies demonstrate a favourable pharmacokinetic profile for TAK-063 with good brain distribution supporting the feasibility of targeting central nervous system regions involved in schizophrenia pathophysiology. TAK-063 has recently been investigated in a phase 2 clinical trial (NCT02477020).


Assuntos
Antipsicóticos/farmacocinética , Inibidores de Fosfodiesterase/farmacocinética , Diester Fosfórico Hidrolases/efeitos dos fármacos , Pirazóis/farmacocinética , Piridazinas/farmacocinética , Animais , Antipsicóticos/metabolismo , Biotransformação , Células CACO-2 , Inibidores das Enzimas do Citocromo P-450/farmacologia , Cães , Meia-Vida , Humanos , Absorção Intestinal , Masculino , Inibidores de Fosfodiesterase/metabolismo , Ligação Proteica , Pirazóis/metabolismo , Piridazinas/metabolismo , Ratos , Ratos Long-Evans , Ratos Sprague-Dawley , Distribuição Tecidual
9.
Wilderness Environ Med ; 28(4): 313-317, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28867139

RESUMO

A 74-year-old man was attacked by a wild boar while on his way home from his farm in the daytime in winter 2017 on the rural Izu peninsula. He did not provoke the boar; however, hunters were hunting animals in the mountains near the farm around the same time. The boar bit his left leg, and the man fell to the ground. The boar continued biting the man's left leg, and the man delivered a few kicks to the boar's face with his right leg. The boar then bit his right foot and ran away. The man was taken to a hospital, and a physical examination revealed 3 bite wounds on his left leg and right foot. The wounds were irrigated with sterilized saline and closed with sutures under local anesthesia. He received antibiotics and a tetanus toxoid booster. The next day, his wounds were found to be infected, and pus was drained from them. After these treatments, his wounds healed successfully. Animal bite wounds are frequently contaminated. Accordingly, in addition to early proper wound treatment, close observation of the wound is required for both the early detection of any signs of infection and early medical intervention, including appropriate drainage of pus and irrigation as necessary.


Assuntos
Agressão , Mordeduras e Picadas/tratamento farmacológico , Mordeduras e Picadas/cirurgia , Sus scrofa/fisiologia , Idoso , Animais , Mordeduras e Picadas/etiologia , Humanos , Japão , Masculino , Resultado do Tratamento
10.
Chem Pharm Bull (Tokyo) ; 64(6): 602-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27250795

RESUMO

A toxic mushroom, Russula subnigricans, causes fatal poisoning by mistaken ingestion. In spite of the potent bioactivity, the responsible toxin had not been identified for about 50 years since its first documentation. Recently, we isolated an unstable toxin and determined the structure. The slow elucidation was partly due to the instability of the toxin and also due to misidentification of R. subnigricans for similar mushrooms. To discriminate genuine Russula subnigricans from similar unidentified Russula species, we searched for a unique chemical marker contained in the mushroom. Cyclopropylacetyl-(R)-carnitine specific to R. subnigricans was identified as a novel compound whose (1)H-NMR signals appearing in the upfield region were easily recognizable among the complicated signals of the crude extract.


Assuntos
Agaricales/química , Carnitina/análogos & derivados , Carnitina/análise , Estrutura Molecular , Espectroscopia de Prótons por Ressonância Magnética , Estereoisomerismo
11.
Ultrasonics ; 44 Suppl 1: e491-6, 2006 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-16793082

RESUMO

As a method to measure the concentration and property of a particle suspension, we proposed an ultrasonic measurement method using a plano-concave ultrasonic transducer. To carry out the experiment, we used a focused ultrasonic impulse with a broad frequency bandwidth radiated from the transducer, instead of utilizing continuous waves as in the conventional method. By analyzing the frequency components of the echo returned from the reflector put at the focal region of the transducer in suspension, we measured the concentration, etc., from variations of attenuation in the frequency spectrum. As specimens, we used some substances containing fine particles for which the acoustic properties or sizes are heterogeneous to each other. Specifically, the milk fat included in milk was examined in detail to characterize the best-tasting milk. In conclusion, we determined that the particle concentration and acoustic properties were easily and instantaneously measurable using the frequency spectrum obtained from pulse echoes passed through the specimen liquid, and the plano-concave transducer was advantageous in these measurements.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...