Radiopaque properties of polyetheretherketone crown at laboratory study.

OBJECTIVES: There have been no reports on the radiopaque properties of new polyetheretherketone (PEEK) crowns for locating crowns during accidental ingestion or aspiration and detection of secondary caries, which is essential information for clinical application. This study aimed to investigate whether the radiopaque properties of PEEK crowns could be used to identify the site of accidental ingestion or aspiration and detect secondary caries. METHODS: Four types of crowns were fabricated: three non-metal crowns (PEEK, hybrid resin, and zirconia) and one full metal cast crown (gold-silver-palladium alloy). Initially, the images for these crowns were compared using intraoral radiography, chest radiography, cone-beam computed tomography (CBCT), and multi-detector computed tomography (MDCT); computed tomography (CT) values were calculated. Subsequently, the images for the crowns placed on the secondary caries model with two artificial cavities were compared using intraoral radiography. RESULTS: The PEEK crowns displayed the lowest radiopaque properties on radiography and very few artifacts were observed on CBCT and MDCT. On the other hand, the CT values of the PEEK crowns were a little lower than those of the hybrid resin crowns and considerably lower than the zirconia and full metal cast crowns. The cavity could be detected in the PEEK crown-placed secondary caries model through intraoral radiography. CONCLUSIONS: This simulated study of radiopaque properties with four types of crowns suggested that a radiographic imaging system can be used to identify the site of accidental ingestion and aspiration of PEEK crowns and to detect secondary caries of the abutment tooth within a PEEK crown.

Gait bradykinesia: difficulty in switching posture/gait measured by the anatomical y-axis vector of the sole in Parkinson's disease.

This study in Parkinson's disease examined how spatiotemporal parameters in gait bradykinesia link to difficulty in terminating posture and initiating gait locomotion. 41 idiopathic Parkinson's disease patients and 15 age-matched healthy subjects participated in this study. After the patients fixated on a visual-fixation-target, gait was triggered by visual or vocal cue-stimulus. The LED instructed subjects to quickly achieve their own comfortable walking speed on a level floor. The posterior-anterior force of the y-axis vectors of sole relating to soleus and tibialis-anterior EMGs were examined. Step-gain was defined as the duration of the swing-phase relative that of the contralateral stance-phase. Dynamic-ratio was defined as the duration the fore-foot phase relative to that of the ipsilateral stance-phase as forward-oriented movement in each step. The pause in tonic soleus EMG was defined as the off-latency of posture (termination) and the onset of a tibialis-anterior EMG-burst as the on-latency of gait. In Parkinson's disease, soleus off-latencies were prolonged, whereas tibialis-anterior on-latencies were less prolonged. Unsynchronized off/on-latency differences correlated with spatiotemporal parameters of dynamic-ratios, step-gains, gait-initiation, and gait speed in gait bradykinesia. Delayed EMG off-latencies correlated with prolonged motor-latencies in gait bradykinesia as delayed initial backward body-shift. A delayed and deficient initial backward body-shift of y-axis vector was linked to each difficulty in terminating posture and initiating gait, changing to random gait akinesia. Gait bradykinesia in Parkinson's disease stemmed from unsynchronized off/on-latency EMG activities, linking to each difficulty in terminating posture and initiating gait synergic movement through an initial backward body-shift.

Gait bradykinesia in Parkinson's disease: a change in the motor program which controls the synergy of gait.

This study examined how gait bradykinesia is changed by the motor programming in Parkinson's disease. Thirty-five idiopathic Parkinson's disease patients and nine age-matched healthy subjects participated in this study. After the patients fixated on a visual-fixation target (conditioning-stimulus), the voluntary-gait was triggered by a visual on-stimulus. While the subject walked on a level floor, soleus, tibialis anterior EMG latencies, and the y-axis-vector of the sole-floor reaction force were examined. Three paradigms were used to distinguish between the off-/on-latencies. The gap-task: the visual-fixation target was turned off; 200 ms before the on-stimulus was engaged (resulting in a 200 ms-gap). EMG latency was not influenced by the visual-fixation target. The overlap-task: the on-stimulus was turned on during the visual-fixation target presentation (200 ms-overlap). The no-gap-task: the fixation target was turned off and the on-stimulus was turned on simultaneously. The onset of EMG pause following the tonic soleus EMG was defined as the off-latency of posture (termination). The onset of the tibialis anterior EMG burst was defined as the on-latency of gait (initiation). In the gap-task, the on-latency was unchanged in all of the subjects. In Parkinson's disease, the visual-fixation target prolonged both the off-/on-latencies in the overlap-task. In all tasks, the off-latency was prolonged and the off-/on-latencies were unsynchronized, which changed the synergic movement to a slow, short-step-gait. The synergy of gait was regulated by two independent sensory-motor programs of the off- and on-latency levels. In Parkinson's disease, the delayed gait initiation was due to the difficulty in terminating the sensory-motor program which controls the subject's fixation. The dynamic gait bradykinesia was involved in the difficulty (long off-latency) in terminating the motor program of the prior posture/movement.

Therapeutic strategy for granulomatous lobular mastitis: a clinicopathological study of 12 patients.

Granulomatous lobular mastitis (GLM) is a rare inflammatory pseudotumor. No therapeutic modality for this disease has been established because of its rarity. The purpose of this study is to evaluate the treatment strategies of GLM. Twelve women who met the histological criteria for GLM were retrospectively studied. The clinical data and the presentation, histopathology, and management of the disease were analyzed by reviewing the patients' medical records. The diagnosis of GLM was confirmed histologically by core needle biopsy in 9 cases, by vacuum-assisted biopsy in 2 cases, and by excisional biopsy in 1 case. Ten patients received corticosteroid treatment and another two patients were treated with local excision or incision and drainage. The median initial dosage of corticosteroid (Prednisolone) was 30 mg/day (range: 15-60 mg/day), and the dosages were tapered according to improvement. The median duration of corticosteroid treatment was 5 months (range: 1-12 months). The median follow-up period was 22 months (range: 6-104 months), and no patient treated with corticosteroid demonstrated recurrence. However, patients treated with excision or incision and drainage had recurrences. These results suggest that steroid treatment may be the first choice in treatment strategies for GLM.

Effects of stroke-induced damage to swallow-related areas in the brain on swallowing mechanics of elderly patients.

AIM: Our objective was to determine the relationship between defective swallowing mechanics and the location of brain lesions in stroke patients. METHODS: We evaluated swallowing mechanics in 37 stroke patients and 10 age-matched control subjects by videofluoroscopy. Subjects were asked to swallow 10 successive 1.0-mL and three successive 2.5-mL boluses of barium suspension at intervals of approximately 15-30 s. We measured oral transit time, pharyngeal delay time and pharyngeal transit time. RESULTS: Patients could be divided into two groups based on the pharyngeal delay time for a 1.0-mL bolus swallow. One group showed little variation during successive swallowing tests, similar to the control group. In the other group pharyngeal delay times varied during successive trials often tending to increase with successive swallows. Magnetic resonance imaging studies of the brain revealed infarcts or hemorrhages in swallow-related areas in the latter group, while in the former group lesions were localized to areas unrelated to swallowing. CONCLUSION: Damage to swallow-related areas may reduce their sensitivity to incoming signals from the oral cavity thereby impairing preparations to generate motor command signals and compromising their ability to send sufficient voluntary descending command signals to activate the swallowing central pattern generator located in the medulla. This deficiency becomes more evident with successive swallows and manifests as impaired swallowing mechanics.

A case of intracystic papillary carcinoma accompanying widespread ductal carcinoma in situ.

A 39-year-old Japanese woman noticed a right breast tumor in July 2004. Mammography (MMG) demonstrated an oval tumor without calcification. Dynamic Magnetic Resonance Imaging (D-MRI) demonstrated a high-intensity mass on T2-weighted images, showing mild enhancement during the arterial phase and persistent enhancement during the arterial late phase. Core needle biopsy revealed papillary carcinoma suggestive of Intracystic Papillary Carcinoma (IPC). Auchincloss operation was performed following a partial mastectomy, as the surgical margin after partial mastectomy was positive for carcinoma. Histopathologic mapping of her right breast revealed wide and extensive intraductal spread of DCIS around the IPC. IPC was originally reported to be a localized non-invasive mammary carcinoma. But approximately, half of IPC cases are associated with invasive carcinoma or DCIS beyond the tumor. Careful selection of operative procedure is needed after localized non-invasive IPC or IPC associated with DCIS around the main tumor or invasive carcinoma is diagnosed.

Non-palpable and non-invasive ductal carcinoma with bloody nipple discharge successfully resected after cancer spread was accurately diagnosed with three-dimensional computed tomography and galactography.

A case of ductal carcinoma in situ (DCIS) that was treated by partial mastectomy is reported. The operation was performed after accurate estimation of cancer spread by three-dimensional computed tomography (3D-CT). The patient was a 39-year-old woman without a palpable lump who had a bloody nipple discharge. Ultrasonography showed distended mammary ducts with intraductal components. Fine needle aspiration cytology revealed ductal carcinoma. Galactography showed two subsegmental ducts and peripheral branches in the upper-inner quadrant of the right breast. 3D-CT depicted a well enhanced segmental-clumped lesion including two subsegments of a duct lobular system shown in galactograms. DCIS was diagnosed and partial mastectomy following the video assisted thoracoscopic surgery (VATS) marker insertion was performed, after cancer spread was accurately diagnosed by 3D-CT guidance. DCIS resected by minimally sufficient partial mastectomy with negative surgical margins was diagnosed histopathologically.

Posterior-anterior body weight shift during stance period studied by measuring sole-floor reaction forces during healthy and hemiplegic human walking.

Posterior-anterior body weight shift during stance phase of human overground locomotion was investigated by recording sole-floor reaction force from five anatomically discrete points with strain gauge transducers of 14 mm diameter attached firmly to the sole of bare foot. At first the subject was asked to walk straight on the laboratory floor at his/her preferred velocity. Then the subject was asked to walk curved path of about 1m radius. For kicking off the body at the end of stance phase, sole-floor reaction force from 3rd metatarsal was stronger than 1st metatarsal or 5th metatarsal during the straight walking, thus body weight shift is represented from heel to 3rd metatarsal line. When walking along a curved path, two types of strategies were recognized; a group of subjects walked leaning to inner leading foot during stance period as judged by stronger forces recorded from 5th metatarsal combined with stronger force from 1st metatarsal of outer trailing foot. Another group of subjects showed almost the same patterns either in the straight and curved walking, suggesting the subjects changed direction of the foot during the immediately previous swing phase to the tangent direction of the curve and placed the foot without leaning the body weight to either direction. Hemiplegic patients showed strikingly different distribution of sole-floor reaction forces from the five points; strongest forces were recorded from 3rd and 5th metatarsals combined with reduced reaction force from heel, therefore characteristic y-vector patterns were observed.

Treadmill walking and overground walking of human subjects compared by recording sole-floor reaction force.

In order to clarify differences of treadmill from overground locomotion, experiments were carried out on 10 volunteers (five males and five females). Sole-floor reaction force was recorded from five anatomically discrete points with strain gauge transducers of 14 mm diameter attached firmly to the sole of bare-foot. At first the subject was asked to walk on the laboratory floor at his/her preferred velocity. After the average velocity was obtained, the subject was asked to walk on the treadmill at the same velocity of average overground walking. Stance period at treadmill walking shortened to 93.3% (P < 0.01) of the value at overground walking. Coefficient of variation of stance period was significantly smaller at the treadmill walking than at overground walking. Strain gauge-floor contact times were shorter in the treadmill walking; heel 81.2%, first metatarsal 93.5%, third metatarsal 93.6%, fifth metatarsal 90.6% and at great toe 93.2% of overground locomotion. Cadence during treadmill locomotion was significantly larger than overground walking (106.6%, P < 0.05). These results show that when subjects walk on the treadmill and on laboratory floor at the identical speed, stance period shortened by 6.7% while cadence increased by 6.6% on the treadmill.

Medial-lateral balance during stance phase of straight and circular walking of human subjects.

Right and left balance during human locomotion has been estimated by the distance between locations of the sequential right and left heel-strikes, or step width. During the stance phase of human locomotion one leg maintains medial-lateral balance for the progression. We focused our attention on this point, and medial-lateral balance during straight-ahead and circular walking was investigated by recording sole-floor reaction force from five anatomically discrete points of human sole; calcaneus, 1st, 3rd, 5th metatarsals and great toe. Forces from these points were recorded during straight walking and circular walking. Medial-lateral balance was obtained by subtracting force at 5th metatarsal from force at 1st metatarsal (x-axis vector). The foot takes off the floor from medial balance in most steps, although in some steps the foot takes off from lateral balance at slower walking speed at 2 km/h or 4 km/h, showing variable patterns of x-axis vector. At faster walking speed at 6 km/h or 8 km/h body weight shifted to 1st metatarsal before taking off the floor. During circular walking body weight shift to 1st metatarsal in the outer foot, and to 5th metatarsal in the inner foot in most cases.

Visuomotor dependency on an initial fixation target involved in the disorder of visually-guided manual movement in Parkinson's disease.

Role of a central fixation target on the latencies of visually guided manual movement was analyzed on young healthy subjects, age-matched control subjects and patients with Parkinson's disease (Hoehn and Yahr stages II, III, and IV). Two paradigms were used: overlap paradigm where a central fixation target was lighted throughout the test, and gap paradigm where a central fixation target was turned off 200 ms before a peripheral target was lighted. The subject was first asked to fixate the central target then instructed to locate a peripheral target with a laser beam spot, operated with wrist flexion or extension as quickly as possible. Latencies of gap paradigm are always shorter than those of overlap task in all the groups. Latencies of both overlap and gap tasks prolonged from young to elder, from elder to PD II, from PD II to PD III and from PD III to PD IV. Also latencies were extremely prolonged in the overlap tasks and correlated with disease severity. Latencies in the gap tasks were less prolonged as compared with those in the overlap tasks. The visual fixation target prolonged the visuo-motor latency in association with severity of Parkinson's disease.

Analysis of human locomotion by recording sole-floor reaction forces from anatomically discrete points.

Sole-floor reaction forces were recorded from five anatomically discrete points to analyze characteristics of human locomotion. Strain gauge of 14 mm diameter were firmly attached to the sole of bare-foot for recording force changes from the following five points: (1) medial process of calcaneus, (2) head of 1st metatarsal, (3) head of 3rd metatarsal, (4) head of 5th metatarsal and (5) great toe. Fifteen healthy adults were asked to walk at 2, 4, 6 and 8 km/h and to run at 8 km/h on the treadmill. Sole-floor reaction forces from 1st to 5th metatarsals show reciprocal changes during stance phase, while force from 1st metatarsal is strong 5th metatarsal shows weak reaction and vice versa. This phenomenon may be an expression of locomotor program to maintain vertical stability of the body during stance phase. There was a linear relation between walking speeds and sum of force from the five points, although sum of forces from three metatarsals did not change significantly during the walking speeds, indicating mainly calcaneus and great toe contribute to increasing walking speed. During running the sum of force from the three metatarsals increased sharply, joining the other two points to increase thrust.

Progression of human body sway during successive walking studied by recording sole-floor reaction forces.

Strain gauge transducers were firmly attached to five points of the human sole: calcaneus, 1st, 3rd, and 5th metatarsals and great toe. Forces from these five points were recorded during treadmill walking at different speeds. With this method it is possible to obtain data of several dozen steps successively. Lateral-medial force change (x-vector) during progression was obtained from the 5th and 1st metatarsals and posterior-anterior force change (y-vector) was obtained from the calcaneus and 3rd metatarsal. Lateral balance and medial balance were differentiated in x-vector and rearfoot phase and forefoot phase were distinguished in y-vector. The percentage of the forefoot phase among the stance period shows a linear increase with speed of progression. It was concluded that the phase of body sway forward is regulated by walking speeds.

Mucocele-like tumor of the breast caused by ductal carcinoma in situ: a case report.

A mucocele-like tumor (MLT) of the breast caused by clinging and micropapillary carcinoma in situ is reported. The tumor was a smooth-contoured mass located near the nipple in the lower inner quadrant of the left breast. Ultrasonography showed a cystic tumor and distended ducts. An aspiration specimen contained abundant mucinous material and a small amount of epithelial cell components, but was insufficient for cytological diagnosis. An excisional biopsy specimen disclosed multiple cysts containing mucin with extravasation into the stroma. Additional pathologic diagnosis using consecutive microscopic sections demonstrated ductal carcinoma in situ. Subcutaneous mastectomy was subsequently performed. Histopathologic findings in the resected and biopsy specimens indicated a diagnosis of MLT caused by widely spreading clinging and micropapillary ductal carcinoma in situ. The ductal epithelium of the MLT in an open biopsy specimen must be carefully examined using consecutive microscopic sections to detect occult DCIS.