Monitoring of magmatic-hydrothermal system by noble gas and carbon isotopic compositions of fumarolic gases.

We repeatedly measured isotopic compositions of noble gases and CO2 in volcanic gases sampled at six fumaroles around the Kusatsu-Shirane volcano (Japan) between 2014 and 2021 to detect variations reflecting recent volcanic activity. The synchronous increases in 3He/4He at some fumaroles suggest an increase in magmatic gas supply since 2018. The increase in magmatic gas supply is also supported by the temporal variations in 3He/CO2 ratios and carbon isotopic ratios of CO2. The 3He/40Ar* ratios (40Ar*: magmatic 40Ar) show significant increases in the period of high 3He/4He ratios. The temporal variation in 3He/40Ar* ratios may reflect changes in magma vesicularity. Therefore, the 3He/40Ar* ratio of fumarolic gases is a useful parameter to monitor the current state of degassing magma, which is essential for understanding the deep process of volcanic unrest and may contribute to identifying precursors of a future eruption. These results provide additional validation for the use of noble gas and carbon isotopic compositions of fumarolic gases for monitoring magmatic-hydrothermal systems.

Magnetization of mesenchymal stem cells using magnetic liposomes enhances their retention and immunomodulatory efficacy in mouse inflamed skeletal muscle.

Sarcopenia, an age-related reduction in skeletal muscle mass and strength, is mainly caused by chronic inflammation. Because mesenchymal stem cells (MSCs) have the capacity to both promote myogenic cell differentiation and suppress inflammation, they are a promising candidate for sarcopenia treatment. In this study, to achieve the long-term retention of MSCs in skeletal muscle, we prepared magnetized MSCs using magnetic anionic liposome/atelocollagen complexes that we had previously developed, and evaluated their retention efficiency and immunomodulatory effects in mouse inflamed skeletal muscle. Mouse MSCs were efficiently magnetized by incubation with magnetic anionic liposome/atelocollagen complexes for 30 min under a magnetic field. The magnetized MSCs differentiated normally into osteoblasts and adipocytes. Additionally, non-magnetized MSCs and magnetized MSCs increased IL-6 and inducible nitric oxide synthase mRNA expression and decreased TNF-α and IL-1ß mRNA expression in C2C12 mouse skeletal muscle myotubes through paracrine effects. Moreover, magnetized MSCs were significantly retained in cell culture plates and mouse skeletal muscle after their local injection in the presence of a magnetic field. Furthermore, magnetized MSCs significantly increased IL-6 and IL-10 mRNA expression and decreased TNF-α and IL-1ß mRNA expression in inflamed skeletal muscle. These results suggest that magnetized MSCs may be useful for effective sarcopenia treatment.

Enhanced macrophage delivery to the colon using magnetic lipoplexes with a magnetic field.

Magnetically guided cell delivery systems would be valuable to achieve effective macrophage-based cell therapy for colonic inflammatory diseases. In the current study, we developed a method for the efficient and simultaneous introduction of superparamagnetic iron oxide nanoparticles (SPIONs) and plasmid DNA (pDNA) into RAW264 murine macrophage-like cells using SPION-incorporated cationic liposome/pDNA complexes (magnetic lipoplexes). SPIONs and pDNA were introduced for magnetization and functionalization of the macrophages, respectively. We also evaluated the adhesive properties of magnetized RAW264 cells using magnetic lipoplexes in the murine colon under a magnetic field. Significant cellular association and gene expression without cytotoxicity were observed when magnetic cationic liposomes and pDNA were mixed at a weight ratio of 10:1, and SPION concentration and magnetic field exposure time was 0.1 mg/mL and 10 min, respectively. We also observed that cytokine production in magnetized RAW264 cells was similar to that in non-treated RAW264 cells, whereas nitric oxide production was significantly increased in magnetized RAW264 cells. Furthermore, magnetized RAW264 cells highly adhered to a Caco-2 cell monolayer and colon in mice, under a magnetic field. These results suggest that this magnetic cell delivery system can improve the colonic delivery of macrophages and its therapeutic efficacy against colonic inflammatory diseases.

Assessment of the relationship between the mandibular cortex on panoramic radiographs and the risk of bone fracture and vascular disease in 80-year-olds.

OBJECTIVES: The objective of this study was to assess cortical measurements on panoramic radiographs in 80-year-old subjects to predict bone fracture and vascular disease risks. METHODS: The cortical width and shape (normal cortex, mildly to moderately eroded cortex, and severely eroded cortex) were evaluated on 659 panoramic radiographs obtained from 262 men and 397 women, all of whom were 80 years old. At baseline, a general medical examination, including heel bone density, was performed in all subjects. Fractures and vascular disease occurring within 5 years after the baseline examination were determined in 191 subjects and in 108 subjects who died within 5 years after the baseline examination. RESULTS: There were significant correlations between heel bone density and cortical width (r = 0.435, P < .001) and shape (r = 0.231, P < .001). However, cortical measurements on panoramic radiographs were not significantly associated with the occurrence of fractures and vascular disease within 5 years after the baseline examination. CONCLUSIONS: Among the elderly, cortical measurements on panoramic radiographs may be associated with bone mineral density and physical activity, but they are not useful markers for the subsequent occurrence of fractures and vascular disease.

Can the presence of carotid artery calcification on panoramic radiographs predict the risk of vascular diseases among 80-year-olds?

OBJECTIVE: The purpose of this study was to evaluate whether subsequent vascular diseases and related death could be predicted by the presence of carotid artery calcification detected on panoramic radiographs among elderly persons. STUDY DESIGN: We evaluated 659 panoramic radiographs from 262 male and 397 female 80-year-old subjects and their general medical examination data to assess the relationship between the presence of carotid artery calcification and vascular disease risk at baseline examination. Of these subjects, the occurrence of vascular diseases within 5 years after baseline examination was examined in 191 subjects. Further, the causes of death were examined in 108 subjects who died within 5 years after baseline examination. RESULTS: There was a significant difference in the history of past vascular diseases among subjects with and without carotid artery calcifications; however, no significant difference in the occurrence of subsequent vascular diseases was found among them. Further, there was no significant difference in the occurrence of vascular disease-related death within 5 years after baseline examination among subjects with and without carotid artery calcifications (P = 0.719). CONCLUSION: Our results suggest that the presence of carotid artery calcifications on panoramic radiographs may be related to the history of past vascular diseases; however, this is not a useful marker for subsequent vascular diseases and related death among 80-year-olds.

Utility of diffusion-weighted images using fast asymmetric spin-echo sequences for detection of abscess formation in the head and neck region.

OBJECTIVE: The objective of this study was to evaluate the utility of new diffusion-weighted magnetic resonance images (DWI) using fast asymmetric spin-echo (FASE) sequences for the detection of abscess formation in patients with phlegmon in the oral and maxillofacial regions. METHODS: We compared diffusion-weighted images using FASE sequences with those using the gradient-echo type of echo-planar images (EPI) in 10 control volunteers and 10 patients with phlegmon in the oral and maxillofacial regions. RESULTS: Many kinds of tissues in the oral and maxillofacial regions were relatively well visualized in all subjects on FASE-DWI, but not well on EPI-DWI. Apparent diffusion coefficients calculated from FASE sequences in abscess areas of patients with phlegmon were significantly lower than those in abscess-free areas; however, apparent diffusion coefficients calculated from EPI were not significantly different due to prominent distortion in small sample size study. CONCLUSIONS: We could accurately recognize the presence of abscess formation within inflammatory tissue in 5 patients with phlegmon using FASE-DWI. As an additional magnetic resonance examination, FASE-DWI might be useful in the detection of abscess formation in the oral and maxillofacial regions.

Three-dimensional identification of hemangiomas and feeding arteries in the head and neck region using combined phase-contrast MR angiography and fast asymmetric spin-echo sequences.

OBJECTIVE: To evaluate a proposed technique for the 3-dimensional (3D) detection of hemangiomas, including vascular malformation and their feeding arteries, in the head and neck. The new technique combines phase-contrast magnetic resonance angiography (PCMRA) without contrast medium and 3D fast asymmetric spin-echo (FASE) sequences. METHODS: The technique was applied to 3 patients having hemangiomas in the head and neck region. In 1 patient the image obtained with the proposed technique was compared to that obtained by standard contrast angiography. RESULTS: In all 3 patients, the 3D presence of the hemangiomas and the feeding arteries were well defined in images created by the proposed technique. Additionally, the characterization of the hemangioma's 3D structure and distribution of the feeding arteries coincided with those observed using contrast angiography in the case for which contrast angiography was also performed. CONCLUSIONS: Preliminary experience shows that the proposed technique combining 3D-FASE and 3D-PCMRA is useful to visualize both the 3D structure of hemangiomas and to identify the 3D distribution of the feeding arteries without using contrast medium.

The functional evaluation of salivary glands using dynamic MR sialography following citric acid stimulation: a preliminary study.

OBJECTIVE: We introduce a new technique for the functional evaluation of the salivary glands using continuous magnetic resonance (MR) sialography before and after citric acid stimulation. METHODS: In 10 volunteers, the time-dependent changes in the maximum area of the detectable parotid gland ducts on MR sialographic images taken every 30 seconds before and after citric acid stimulation were analyzed. The time period to the occurrence of the maximum duct area poststimulation was noted, and then the time for the area to return to its 50% value pre-citric acid stimulation was also observed. This new technique was clinically applied in 1 patient with an excessive supply impression of saliva and in 1 patient with a short supply impression with saliva. RESULTS: In all volunteers after citric acid stimulation, the maximum area of the detectable salivary gland ducts first increased and then decreased. A strong relationship was found between the maximum area of the detectable salivary gland ducts before citric acid stimulation and total saliva volume (Pearson r = 0.672, P = .031). Compared with all the volunteers, the ratio of change in the detectable ducts was the highest in the patient with an excessive supply impression of saliva, but lowest in the patient with a short supply impression with saliva. CONCLUSIONS: This initial study suggests that dynamic MR sialography allows for functional and morphological evaluation of the salivary glands. This technique appears to have many possible applications and further investigation in this field is necessary.

Utility of magnetic resonance cisternography using three-dimensional fast asymmetric spin-echo sequences with multiplanar reconstruction: the evaluation of sites of neurovascular compression of the trigeminal nerve.

OBJECTIVE: To evaluate the utility of magnetic resonance (MR) cisternography using 3-dimensional (3D) fast asymmetric spin-echo (FASE) sequences with multiplanar reconstruction (MPR) for detection of the sites of neurovascular compression (NVC) in patients with trigeminal neuralgia. STUDY DESIGN: Both MR cisternography with 3D-FASE sequences and MR angiography (MRA) were performed on 150 patients with clinical signs and symptoms that suggested trigeminal neuralgia. Results from the original MR cisternography with 3D-FASE sequences, the original MRA, and 4 reformatted images were used for interpretation. Images with inversion between black and white were used from the MR cisternography with 3D-FASE sequences to evaluate NVC. A diagnosis of NVC was made from the presence of vascular contact with the trigeminal nerve at the root entry zone (REZ) and the nature of the involved vessels. For the patients with NVC detectable on 3D-FASE or MRA images, the relationship between the clinically manifested regions and the NVC sites was also evaluated. RESULTS: Of the 150 patients evaluated, 89 were deemed to have NVC. Of these 89 patients, 3 underwent surgery that identified the artery that was involved with the trigeminal nerve. The correlation between the clinically manifested regions and the NVC sites was significantly detectable using both 3D-FASE images and MRA in 89 patients with detectable NVC. The correlation coefficient using 3D-FASE imaging was a little higher than that using MRA. Of the 61 patients deemed not to have NVC, 6 were found to have brain tumors that invaded the root entry zone of the trigeminal nerve. However, the remaining 55 patients had no identifiable cause for trigeminal neuralgia. NVC was found in the asymptomatic side in 27 (18%) of the 150 patients with trigeminal neuralgia using MR cisternography with 3D-FASE sequences. CONCLUSIONS: The technique of MR cisternography using 3D-FASE sequences with MPR is more accurate and useful than MRA for detection of the site of NVC in patients with trigeminal neuralgia. Patients with trigeminal neuralgia should be further examined using MR imaging to rule out a brain tumor. Radiologists should understand that a few subjects with no symptoms could show NVC with MR cisternography.

Evaluation of the relationship between periapical lesions/sclerotic bone and general bone density as a possible gauge of general health among 80-year-olds.

OBJECTIVES: To evaluate the incidence among 80-year-olds of periapical lesions as detected on panoramic radiographs and to determine the relationship between sclerotic bone around the periapical lesions to heel bone density, body height, and hand-grip strength. STUDY DESIGN: Six hundred fifty-nine panoramic radiographs (262 males, 397 females), obtained from 80-year-old residents of Fukuoka Prefecture, Japan, were used for evaluation of periapical lesions. These findings were correlated with physical examination results to determine the relationship to general health. RESULTS: Of 659 panoramic radiographs, 31 (5%) were noted to have periapical lesions. Average size of the 31 periapical lesions was 6.1 +/- 2.2 mm. Of the 31 periapical lesions, 21 (68%) were accompanied by linear or diffuse types of sclerotic bone. Of the 21 sclerotic bones, 10 (48%) were of a linear type of sclerotic bone and 11 (52%) of a diffuse type of sclerotic bone. Of the 11 diffuse types of sclerotic bone, 10 (91%) were in the mandible and 1 (9%) in the maxilla. Periapical lesions in the mandible were more frequently accompanied by a diffuse type of sclerotic bone than those in the maxilla (P < .01). The hand-grip strength of those having periapical lesions, accompanied by a diffuse type of sclerotic bone, was stronger than those having no periapical lesions (P < .01) and those accompanied by a linear type of sclerotic bone (P < .03). However, there was no relationship between presence of sclerotic bone and heel bone density or body height. CONCLUSIONS: Periapical lesions accompanied by a diffuse type of sclerotic bone were more frequently seen in the mandible of 80-year-olds. To evaluate the clinical significance of sclerotic bone around periapical lesions in 80-year-olds, further study to evaluate the significance of endodontic treatment needs to be done.

Alternation of the magnetic resonance signals characteristic of mandibular condyles during growth.

OBJECTIVE: In a previous study, we named the magnetic resonance imaging (MRI) signal that is characteristic of mandibular condyles in growing children the "double contour-like structure" (DCLS). In the current study, we evaluated the alternating appearance and disappearance of the DCLS in children as they grow to elucidate the significance of the DCLS. STUDY DESIGN: In 11 subjects who were 9-14 years old at the time of the first examination, MRI characteristics of mandibular condyles were sought from fast spin-echo intermediate-weighted images; 2 or 3 years later, repeat MRI were obtained from the same subjects. RESULTS: At the second examination, 10 of the 16 DCLSs detected at the first examination had disappeared. A significant relationship was found between the alternation of the DCLS and the bone marrow conversion from red to yellow in mandibular condyles. Alternation of the DCLS tended to coincide with eruption of the permanent maxillary second molars. The DCLS was also shown to appear as a hypersignal on T2-weighted images. CONCLUSIONS: Double contour-like structure signals in mandibular condyles appeared and disappeared as children grew, and these signal alternations may be useful as a criterion for the staging of mandibular condyle development in children. Possible constituents of the DCLS may be hypervascular loose fibrous tissue and a proliferation of cartilage.

Clinical application of magnetic resonance sialographic 3-dimensional reconstruction imaging and magnetic resonance virtual endoscopy for salivary gland duct analysis.

PURPOSE: In a previous study, we showed that the new and fast sequence 3-dimensional (3D)-fast asymmetric spin-echo sequencing could be applied in magnetic resonance (MR) sialographic 3D reconstruction imaging of the parotid gland ducts and in producing virtual endoscopic views of the parotid gland with MR data. MATERIALS AND METHODS: In the present study, we examined the clinical application of these MR sialographic 3D reconstruction imaging and virtual endoscopy of the salivary gland ducts using MR data sets with 3D-fast asymmetric spin-echo sequencing. RESULTS: The MR sialographic 3D reconstruction images showed a complete view in the branch paths from all angles, and the MR virtual endoscopic views showed conditions in the endoluminal tracts of the large branches in 20 patients with salivary gland duct abnormalities, including Sjögren syndrome, cyst, tumor, sialadenitis, and salivary calculi. CONCLUSION: The clinical use of MR sialographic 3D reconstruction imaging and MR virtual endoscopy for salivary gland ducts may enhance understanding of the 3D relationship between the ducts and the surrounding tissue, as well as the endoluminal circumstance within ducts. Possible future applications abound, and further investigation in this field is expected.

Significance of frequency-selective fat saturation T2-weighted MR images for the detection of bone marrow edema in the mandibular condyle.

The objective of this study was to evaluate the utility of frequency-selective fat saturation (FS) T2-weighted images (T2WI) for the detection of bone marrow edema in the mandibular condyle. MR evidence of bone marrow abnormalities was examined on the set of FS T2WI and conventional T1WI or of conventional T2WI and T1WI in 200 patients with temporomandibular joint (TMJ) related pain. Other parameters studied were TMJ effusion, disk displacement categories, and cortical bone abnormalities. The detection rate and area of bone marrow edema by FS T2WI and T1WI were significantly greater than those assessed by conventional T2WI and T1WI. The correlation between bone marrow abnormalities on FS T2WI and T1WI and pain was significantly stronger than with conventional T2WI and T1WI. This study confirms that FS T2WI is useful for the detection of the "edema pattern" in the mandibular condylar associated with TMJ-related pain.

Detection and significance of the characteristic magnetic resonance signals of mandibular condyles in children.

OBJECTIVE: We sought to determine the magnetic resonance imaging (MRI) characteristics of mandibular condyles in still-growing children. In addition, we also evaluated the significance of the double-contour-like structure and the conversion from red to yellow marrow characteristic of this age. METHODS: The MRI characteristics of mandibular condyles were determined by means of fast spin-echo intermediate-weighted images in subjects 9 to 14 years old. In 1 subject who developed temporomandibular joint-related clinical symptoms 1 year later, MRI was re-performed at that time. RESULTS: With the use of MRI, a total of 17 double-contour-like structures were detected in 42 temporomandibular joints of 9- to 14-year-olds, but neither 50 healthy joints of youths nor adults. In terms of bone marrow signal changes, the turning point was found to be 11 years old. In 1 subject, the double-contour-like structures were not visible on the MR images obtained 1 year after the first examination. CONCLUSION: The double-contour-like structure and the periods of conversion from red to yellow marrow may be able to be used as part of the criteria for the staging of mandibular condyle development in children.

Inflammatory paradental cyst (IPC) in the mandibular premolar region in children.

OBJECTIVES: We investigated the occurrence of inflammatory paradental cysts (IPC) in the mandibular premolar, and demonstrated the points of difference with regard to diagnostic features between IPC and dentigerous cysts (DC). MATERIAL AND METHODS: We analyzed the radiographs and histology of 60 cases with a cystic lesion associated with inflammation in the mandibular premolar region based on diagnostic criteria as IPC. RESULTS: In 4 out of 60 cases, we diagnosed the 4 cysts as IPCs in the mandibular premolar region, and recognized that one form of IPC was similar to a mandibular infected buccal cyst. The other 56 non-IPC cases were diagnosed as DC. On the IPCs, the permanent tooth normally erupted in all 4 cases after treatment, but in one case, the IPC recurred. CONCLUSIONS: The present investigation suggested that we might have misdiagnosed IPCs in the mandibular premolar region as DC to date. It is important to consider the differences between IPC and DC with regard to the causes of recurrence during treatment of IPC.

Coactivation of Rac1 and Cdc42 at lamellipodia and membrane ruffles induced by epidermal growth factor.

A major function of Rho-family GTPases is to regulate the organization of the actin cytoskeleton; filopodia, lamellipodia, and stress fiber are regarded as typical phenotypes of the activated Cdc42, Rac, and Rho, respectively. Using probes based on fluorescent resonance energy transfer, we report on the spatiotemporal regulation of Rac1 and Cdc42 at lamellipodia and membrane ruffles. In epidermal growth factor (EGF)-stimulated Cos1 and A431 cells, both Rac1 and Cdc42 were activated diffusely at the plasma membrane, followed by lamellipodial protrusion and membrane ruffling. Although Rac1 activity subsided rapidly, Cdc42 activity was sustained at lamellipodia. A critical role of Cdc42 in these EGF-induced morphological changes was demonstrated as follows. First, phorbol 12-myristate 13-acetate, which activated Rac1 but not Cdc42, could not induce full-grown lamellipodia in Cos1 cells. Second, a GTPase-activating protein for Cdc42, KIAA1204/CdGAP, inhibited lamellipodial protrusion and membrane ruffling without interfering with Rac1 activation. Third, expression of the Cdc42-binding domain of N-WASP inhibited the EGF-induced morphological changes. Therefore, Rac1 and Cdc42 seem to synergistically induce lamellipodia and membrane ruffles in EGF-stimulated Cos1 cells and A431 cells.

Evaluation of calcified carotid artery atheromas detected by panoramic radiograph among 80-year-olds.

OBJECTIVE: To evaluate the incidence among 80-year-olds of calcified carotid artery atheromas (CCAAs) as detected on panoramic radiographs. The relationship between CCAAs and general and oral health was also evaluated. STUDY DESIGN: Six hundred and fifty-nine panoramic radiographs (262 males, 397 females), obtained from 80-year-old residents of Fukuoka Prefecture, Japan, were used for evaluation of CCAAs. RESULTS: Of 659 panoramic radiographs, 33 (5%) were noted to have CCAAs. These appeared as a radiopaque nodular mass or masses adjacent to or just below the intervertebral space between C3 and C4. CCAAs were found in 8 males and 25 females. There were marginally significant differences between males and females in CCAAs (P = 0.06). Seventy-four percent of CCAAs were detected in the right side. There appeared to be very little relationship between CCAAs and general and oral health. CONCLUSIONS: The results of this study gives further support to the idea of using panoramic radiographs to detect CCAAs. Therefore, we feel that panoramic radiographs should be evaluated not only for pathosis of the teeth and jaws, but also for other incidental findings, especially in the soft-tissue region of the neck. The findings from this study provide potentially life-saving information especially for those elderly people who are at risk for stroke.