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1.
Int J Implant Dent ; 10(1): 24, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38722448

ABSTRACT

PURPOSE: The objective of the present study was to ascertain the effect of immediate occlusal loading after implant placement on osseointegration and the micro/nanostructure of the surrounding bone. METHODS: After extraction of a rat maxillary right second molar, an implant was placed immediately with initial fixation (2 N< ). The implants were placed to avoid occlusal loading due to mastication, and in the loaded group, a superstructure was fabricated and subjected to occlusal loading. Bone morphometry, collagen fiber anisotropy, and biological apatite (BAp) crystallite alignment were quantitatively evaluated in both groups after extraction and fixation of the jaw bone at Days 7 and 21 after surgery. RESULTS: Osseointegration was observed in both groups. Bone morphometry showed significant differences in bone volume, trabecular number, trabecular thickness and bone mineral density (BMD) at Days 21 postoperatively (P < 0.05). A significant difference was also found in the trabecular separation at Days 7 postoperatively (P < 0.05). In the evaluation of collagen fiber anisotropy, collagen fiber bundles running differently from the existing bone were observed in both groups. In terms of BAp crystallite alignment, a specific structure was observed in the reconstructed new bone after implantation, and preferential orientation of BAp crystallite alignment was observed in the longitudinal direction of the implants in the Day 21 postoperative loaded group. CONCLUSION: When sufficient initial fixation is achieved at the time of dental implant placement, then the applied masticatory load may contribute to rapidly achieving not only bone volume, but also adequate bone quality after implant placement.


Subject(s)
Immediate Dental Implant Loading , Osseointegration , Animals , Rats , Osseointegration/drug effects , Male , Bone Density/physiology , Dental Implants , Rats, Wistar , Maxilla/surgery , Collagen/metabolism , X-Ray Microtomography
2.
Ann Anat ; 254: 152246, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38460858

ABSTRACT

BACKGROUND: In adults, the intermediate tendon of digastricus muscle usually runs along the medial or lateral side of the stylohyoideus muscle insertion. To provide a better understanding of the variations, we examined the topographical anatomy of the muscle and tendon in fetuses. METHODS: We examined histological sections from six early-term, 26 mid-term and six near-term fetuses (approximately 8-9, 12-18 weeks and 25-33 weeks). RESULTS: At early-term, an initial sheath of intermediate tendon of digastricus muscle received the stylohyoideus muscle at the superior aspect. The muscle and tendon was distant from the hyoid. At mid-term, near the insertion to the hyoid greater horn, the stylohyoideus muscle consistently surrounded more than 2/3 of the intermediate tendon circumference. In contrast, we found no near-term specimen in which the stylohyoideus muscle surrounded the intermediate tendon. The multilayered tendon sheath was fully developed until near-term and connected to the body of hyoid by an intermuscular septum between the thyrohyoideus muscle and one or two of suprahyoid muscles. Therefore, the hyoid insertion of the styloglossus muscle was a transient morphology at mid-term. CONCLUSION: The stylohyoideus muscle insertion was appeared to move from the tendon sheath to the hyoid greater horn and, until near-term, return to the tendon sheath. A fascia connecting the tendon sheath to the body of hyoid was strengthened by the suprahyoid and infrahyoid muscles. The latter muscles seemed to regulate fixation/relaxation of the intermediate tendon to the hyoid. The stylohyoideus muscle slips sandwiching the intermediate tendon might be a rare morphology.


Subject(s)
Fetus , Hyoid Bone , Tendons , Hyoid Bone/anatomy & histology , Hyoid Bone/embryology , Humans , Tendons/anatomy & histology , Tendons/embryology , Fetus/anatomy & histology , Neck Muscles/anatomy & histology , Neck Muscles/embryology , Female , Male
3.
Bull Tokyo Dent Coll ; 65(1): 11-17, 2024 Mar 07.
Article in English | MEDLINE | ID: mdl-38355117

ABSTRACT

The morphogenetic process of development of the circumference of the mandibular fossa during tooth eruption, which involves the replacement of deciduous teeth with permanent teeth, is strongly affected by occlusion. To the best of our knowledge, no studies have investigated the effect of occlusion on this process. This study investigated the morphogenetic process of development during tooth eruption using dried skulls harvested from Indian donors. The average distance between the ala-major-squamosa suture and the foramen ovale according to age group was as follows: 3.24 mm in the 8-month-old group and 8.92 mm in the adult group. The average distance between the ala-major-squamosa suture and the apex of the articular tubercle according to age groups was as follows: 10.38 mm in the 8-month-old group and 19.34 mm in the adult group. The average distance between the point of intersection of the petrosquamous fissure and petrotympanic fissure located on the perpendicular line drawn posteriorly from the shortest distance of the medio-lateral axis between the ala-major-squamosa suture and the apex of the articular tubercle according to age group was as follows: 9.68 mm in the 8-month-old group and 14.3 mm in the adult group. These results suggest that the mandibular fossa is strongly affected by load due to occlusion, unlike the growth of the neurocranium. This indicates that the effect of occlusion is a secondary element in the morphogenetic process of development of the circumference of the mandibular fossa.


Subject(s)
Temporal Bone , Temporomandibular Joint , Cephalometry/methods , Dental Occlusion , Mandibular Condyle
4.
Int J Implant Dent ; 9(1): 49, 2023 Dec 08.
Article in English | MEDLINE | ID: mdl-38066306

ABSTRACT

OBJECTIVES: The objective was to investigate the details of the attachments of the mylohyoid muscle to the mandible anterior to the hyoid and mylohyoid lines to understand the positional relationship between the sublingual space and the mylohyoid, knowledge that is essential for dental implant surgery in the incisal region, as well as the routes of communication between the sublingual space and other spaces. METHODS: While evaluating the presence or absence of an anterior mylohyoid muscle fiber attachment to the mandible, sublingual gland herniation, spaces between muscle fascicles were also recorded as sites of penetration. The mean muscle thickness in each of these areas was also calculated. RESULTS: In all specimens, the mylohyoid originated not only from the mylohyoid line but also from the lingual surface of the center of the mandibular body (the mandibular symphysis) below the mental spines. The mylohyoid muscle fascicles were thickest in the posterior region, and further anterior to this, they tended to become thinner. Sublingual gland herniations passing through the mylohyoid were noted in the anterior and central regions, but not in the posterior region. Penetration between the muscle fascicles was most common in the central region, and no such penetration was evident in the posterior region. CONCLUSIONS: These results suggest that the mylohyoid functions only incompletely as a septum, and that routes of communication from the sublingual space to the submandibular space may be present in both the anterior and central muscle fascicles of the mylohyoid. Therefore, bleeding complications during dental implant placement in the anterior mandible can be serious issues. There is a potential for sublingual hematoma that could compromise the airway by pressing the tongue against the soft palate into the pharynx.


Subject(s)
Dental Implants , Mouth Floor/surgery , Neck Muscles , Sublingual Gland/surgery , Tongue/surgery
5.
Int J Nanomedicine ; 17: 4567-4578, 2022.
Article in English | MEDLINE | ID: mdl-36217496

ABSTRACT

Background: NK105 is a paclitaxel (PTX)-incorporating "core-shell-type" polymeric micellar nanoparticle formulation composed of block copolymers (polyethylene glycol and a polyamino acid). The efficacy and safety of NK105 and paclitaxel in advanced or recurrent breast cancer have never been compared at equivalent dose levels. Patients and Methods: Patients were randomly assigned to either NK105 or PTX in a 1:1 ratio. The study drug was administered on Day 1, 8, and 15 of a 28-day cycle with 80 mg/m2. The primary endpoint was overall response rate (ORR), secondary endpoints were progression-free survival (PFS), overall survival (OS), and adverse events. Results: A total of 123 patients (NK105, n=62; PTX, n=61) received one of the two drugs. There was no significant difference in ORR, the median PFS, or OS (NK105 group: 41.9%, 9.1, and 27.5 months, respectively; PTX group: 45.9%, 7.8, and 32.4 months, respectively). Neutropenia occurred more frequently in the NK105 group, but most patients did not require granulocyte-colony stimulating factor or dose-reduction. The median time to onset of peripheral sensory neuropathy (PSN) in the NK105 group was significantly longer than that in the PTX group (p=0.001), and PSN (≥ grade 3) was not observed in the NK105 group. Conclusion: Weekly NK105 administration was well-tolerated. Efficacy was similar in both groups. The PSN profile was better in the NK105 group.


Subject(s)
Breast Neoplasms , Peripheral Nervous System Diseases , Antineoplastic Combined Chemotherapy Protocols , Breast Neoplasms/drug therapy , Colony-Stimulating Factors/therapeutic use , Female , Humans , Paclitaxel/analogs & derivatives , Paclitaxel/therapeutic use , Peripheral Nervous System Diseases/chemically induced , Polyethylene Glycols/therapeutic use , Polymers
7.
Article in English | MEDLINE | ID: mdl-34653003

ABSTRACT

Evaluation of stability or loss of balance in walking persists as an open question. Although an inverted pendulum model is often adopted to evaluate stance leg balance, a stumbling-related balance loss should be associated with the swing leg. We propose a new framework based on a compass gait model that determines whether the current state (i.e., position and velocity) in the swing phase can maintain steady state walking or, instead, fall without active joint torque, which is termed as balance map analysis. The forward and backward balance loss regions are derived by a linear compass gait model. To test the balance map analysis, measurement experiments of steady state walking and stumbled walking are used to validate two hypotheses: 1) the state during steady-state walking is not located in the balance loss region; and 2) if stumbling occurs, the state moves toward the forward balance loss region. The results of the balance map analysis showed good agreement with our prediction in the hypotheses. The minimum Euclid distance from the balance loss region is defined as the margin, and the margin from forward balance loss rapidly decreased after the stumbling perturbation. The statistical results reveal that the margin from the forward balance loss region after perturbation is significantly smaller than the margin in steady state walking. These results suggest that balance map analysis provides a new aspect of walking balance, expanded for the stumbling and recovery behavior of human walking.The code for the balance map analysis is available at https://github.com/TakahiroKagawa/GaitAnalysis_BM.


Subject(s)
Gait , Walking , Accidental Falls , Biomechanical Phenomena , Humans , Postural Balance
8.
Heliyon ; 4(9): e00788, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30225382

ABSTRACT

Next-generation effects and further transgenerational effects of an endocrine disruptor, bisphenol A (BPA), were investigated in zebrafish. The effects of BPA treatment through dietary administration in male and female zebrafish on reproductive factors, such as gonadal activity, fertility, hatching rate and malformation in subsequent generations, were examined through the third filial (F3) generation. BPA treatment of initial generation (F0) not only caused retraction of the ovaries and testes but also lowered the survival rate and increased the rate of malformation of the offspring. Although the overall phenotypes of the surviving first filial (F1) generation offspring of treated fish initially appeared to be normal, we found abnormalities in their reproductive tissues after they matured to adulthood. Although the juveniles were fed a normal diet, the ovaries of 40% of the F1 generation fish remained small and did not develop vitellogenic oocytes. Moreover, sterile male fish appeared at a higher percentage (48%) than control (10%). Adverse transgenerational effects on the fecundity of the second filial (F2) and F3 generation fish were also observed. In each generation, survival rate of embryos were significantly low and abnormal embryos were appeared in offspring from BPA treated ancestral. These results demonstrate that the effects of BPA are transferred to subsequent generations not only through oocytes but also through sperm.

9.
Water Res ; 122: 557-569, 2017 10 01.
Article in English | MEDLINE | ID: mdl-28628878

ABSTRACT

A study was performed to evaluate the effect of thermal hydrolysis pretreatment (THP) temperature on subsequent digestion performance and operation, as well as downstream parameters such as dewatering and cake quality. A blend of primary and secondary solids from the Blue Plains treatment plant in Washington, DC was dewatered to about 16% total solids (TS), and thermally hydrolyzed at five different temperatures 130, 140, 150, 160, 170 °C. The thermally hydrolyzed solids were then fed to five separate, 10 L laboratory digesters using the same feed concentration, 10.5% TS and a solids retention time (SRT) of 15 days. The digesters were operated over a six month period to achieve steady state conditions. The higher thermal hydrolysis temperatures generally improved the solids reduction and methane yields by about 5-6% over the temperature range. The increased temperature reduced viscosity of the solids and increased the cake solids after dewatering. The dissolved organic nitrogen and UV absorbance generally increased at the higher THP temperatures. Overall, operating at a higher temperature improved performance with a tradeoff of higher dissolved organic nitrogen and UV adsorbing materials in the return liquor.


Subject(s)
Hydrolysis , Sewage , Anaerobiosis , Temperature , Water Purification
10.
Plant Signal Behav ; 5(11): 1433-6, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21051956

ABSTRACT

We recently reported that the cwa1 mutation disturbed the deposition and assembly of secondary cell wall materials in the cortical fiber of rice internodes. Genetic analysis revealed that cwa1 is allelic to bc1, which encodes glycosylphosphatidylinositol (GPI)-anchored COBRA-like protein with the highest homology to Arabidopsis COBRA-like 4 (COBL4) and maize Brittle Stalk 2 (Bk2). Our results suggested that CWA1/BC1 plays a role in assembling secondary cell wall materials at appropriate sites, enabling synthesis of highly ordered secondary cell wall structure with solid and flexible internodes in rice. The N-terminal amino acid sequence of CWA1/BC1, as well as its orthologs (COBL4, Bk2) and other BC1-like proteins in rice, shows weak similarity to a family II carbohydrate-binding module (CBM2) of several bacterial cellulases. To investigate the importance of the CBM-like sequence of CWA1/BC1 in the assembly of secondary cell wall materials, Trp residues in the CBM-like sequence, which is important for carbohydrate binding, were substituted for Val residues and introduced into the cwa1 mutant. CWA1/BC1 with the mutated sequence did not complement the abnormal secondary cell walls seen in the cwa1 mutant, indicating that the CBM-like sequence is essential for the proper function of CWA1/BC1, including assembly of secondary cell wall materials.


Subject(s)
Cell Wall/metabolism , Gene Expression Regulation, Plant/physiology , Oryza/metabolism , Plant Proteins/metabolism , Receptors, Cell Surface/chemistry , Receptors, Cell Surface/metabolism , Amino Acid Sequence , Bacterial Proteins/chemistry , Conserved Sequence , Molecular Sequence Data , Mutation , Oryza/genetics , Plant Proteins/chemistry , Plant Proteins/genetics , Receptors, Cell Surface/genetics
11.
Planta ; 232(1): 257-70, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20424856

ABSTRACT

The plant secondary cell wall is a highly ordered structure composed of various polysaccharides, phenolic components and proteins. Its coordinated regulation of a number of complex metabolic pathways and assembly has not been resolved. To understand the molecular mechanisms that regulate secondary cell wall synthesis, we isolated a novel rice mutant, cell wall architecture1 (cwa1), that exhibits an irregular thickening pattern in the secondary cell wall of sclerenchyma, as well as culm brittleness and reduced cellulose content in mature internodes. Light and transmission electron microscopy revealed that the cwa1 mutant plant has regions of local aggregation in the secondary cell walls of the cortical fibers in its internodes, showing uneven thickness. Ultraviolet microscopic observation indicated that localization of cell wall phenolic components was perturbed and that these components abundantly deposited at the aggregated cell wall regions in sclerenchyma. Therefore, regulation of deposition and assembly of secondary cell wall materials, i.e. phenolic components, appear to be disturbed by mutation of the cwa1 gene. Genetic analysis showed that cwa1 is allelic to brittle culm1 (bc1), which encodes the glycosylphosphatidylinositol-anchored COBRA-like protein specifically in plants. BC1 is known as a regulator that controls the culm mechanical strength and cellulose content in the secondary cell walls of sclerenchyma, but the precise function of BC1 has not been resolved. Our results suggest that CWA1/BC1 has an essential role in assembling cell wall constituents at their appropriate sites, thereby enabling synthesis of solid and flexible internodes in rice.


Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis/genetics , Cell Wall/metabolism , Genes, Plant , Mutation , Oryza/genetics , Base Sequence , Cloning, Molecular , DNA Primers , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission
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