Radiographic Characteristics of the Femoral Nutrient Artery Canals in Total Hip Arthroplasty using Cementless Femoral Stem.

Introduction: Accurate diagnosis of undisplaced periprosthetic femoral fracture (PFF) after hip arthroplasty is crucial, as overlooked PFF may affect its treatment and prognosis. The undisplaced PFF is often difficult to distinguish from radiolucent lines of nutrient artery canal (NAC) of the femur present on post-operative radiographs. We aimed to identify the radiographic features of NAC to distinguish them from PFFs. Materials and methods: In this retrospective radiological study, a total of 242 cases in 215 patients with hip arthroplasty were analysed using pre-operative and post-operative anteroposterior (AP) and translateral (TL) radiographs. Interobserver agreement of the measurements was assessed by two independent experienced orthopaedic surgeons. The kappa value ranged from 0.83 to 0.87, indicating strong agreement according to the Landis and Koch criteria. Results: The NACs were found pre-operatively in 94 (39.8%) cases on AP views and in 122 cases (50.4%) on TL views. The radiolucent lines were observed post-operatively in 42 (17.4%) on AP views and 122 (50.4%) on the TL views. three cases (1.2%) had a fracture around the stem that were detected on radiographs. One case with PFF presented simultaneously with NAC on the immediate post-operative radiographs. All patients were treated by conservative measures, and the radiolucent lines did not appear on follow-up radiographs. Conclusion: It is not easy to differentiate undisplaced PFFs that can occur after hip arthroplasty operation from NACs. However, accurate diagnosis is possible through careful observation and comparison of pre-operative and post-operative radiologic images.

Assessment of masticatory function in patients with non-sagittal occlusal discrepancies.

Non-sagittal occlusal discrepancies such as posterior cross-bite and anterior openbite are common types of malocclusion, but studies on masticatory function related to those malocclusions have been scarce. The aim of this study was to quantify the masticatory performance in patients with non-sagittal discrepancies compared to those with normal occlusion, using both objective and subjective measures. Maximum bite force and contact area using Dental Prescale(®) system as a static objective assessment, Mixing Ability Index (MAI) as a dynamic objective evaluation and food intake ability (FIA) as a subjective assessment were analysed from 21 people in normal occlusion (Group N) and 64 patients with posterior cross-bite (Group C), anterior openbite (Group O) or both (Group B). The differences of the maximum bite force, the contact area, the MAI and the FIA were compared, and their correlations were figured out. The non-sagittal malocclusion groups showed lower values in the maximum bite force, the contact area, the MAI and the FIA compared to those in the normal group (P < 0·0001). Compared to Group N, Groups C, O and B showed 61·5%, 42·1% and 40·1% of the maximum bite force, and 84%, 84% and 76% of hard food FIA, respectively. However, there were no significant differences among Groups C, O and B. The MAI showed higher correlation with the FIA (r = 0·38, P < 0·01), than with the maximum bite force and the contact area (both r = 0·24, P < 0·5). These results revealed that masticatory function in patients with non-sagittal discrepancies is significantly reduced both objectively and subjectively.

In vivo and in vitro demonstration of epithelial cell-induced myofibroblast differentiation of keratocytes and an inhibitory effect by amniotic membrane.

PURPOSE: To examine the role of epithelial cells in inducing the differentiation of keratocytes into myofibroblasts and to determine whether this effect may be inhibited by amniotic membrane matrix. METHODS: In vivo, a 9-mm diameter, partial-thickness corneal flap was created in 12 rabbit eyes (6 rabbits), which were equally subdivided into three groups. The first group was implanted with one layer of a 6-mm diameter human amniotic membrane, from which the epithelium had been removed by dispase. The second group received an implantation of dispase-treated amniotic membrane with cultured rabbit corneal epithelial cells. The third group received the same implantation as the second group except that the cultured corneal epithelial cells were sandwiched between two layers of membrane. All corneas were removed 2 weeks later and were subjected to Masson trichrome staining and immunofluorescence staining with monoclonal antibodies to alpha-smooth muscle (alpha-SM) actin for myofibroblasts and cytokeratins for epithelial cells. In vitro collagen gels impregnated with different types of human ocular surface fibroblasts were seeded with or without rabbit corneal epithelial cells before testing for gel contraction. RESULTS: Positive staining of alpha-SM actin was noted only in keratocytes adjacent to corneal epithelial cells at the incision site and those grown on the basement membrane side of the amniotic membrane. Negative staining was noted when epithelial cells were removed by dispase or when cultured corneal epithelial cells were sandwiched between two layers of membrane. Gel contraction by fibroblasts was significantly promoted when epithelial cells were seeded on the gel. In the latter situation, positive staining of alpha-SM actin was noted in fibroblasts subjacent to epithelial cells but not in those impregnated in the gel. CONCLUSION: Epithelial cells are capable of inducing the differentiation of adjacent fibroblasts into myofibroblasts; such an induction requires a close epithelial-mesenchymal contact. Amniotic membrane alone does not induce this effect and can help block such induction by epithelial cells.

Automation of the synthesis of highly concentrated 188Re-MAG3 for intracoronary radiation therapy.

We have developed an efficient method and an automated synthetic system for the preparation of highly concentrated 188Re-MAG3. Routine production of 188Re-MAG3 for use in intracoronary radiation therapy was performed by compressed air driven semi-automated shielded system. 188Re-MAG3 was prepared with a commercial kit and reducing agents, purified and concentrated by C18 Sep-Pak cartridges to desired radioactivity and volume. Using this automated system, reproducible radiolabeling yields of 80-85% were obtained.

Increased numbers of Langerhans cell and expression of HLA-Dr antigen in the giant papilla of patients with giant papillary conjunctivitis.

A study of histopathologic changes, ultrastructure, and expression of the HLA-Dr antigen within the giant papillae of patients with giant papillary conjunctivitis was performed to determine whether cell-mediated immune response is related to this condition. Conjunctival giant papillae from ten patients with giant papillary conjunctivitis were examined by light and electron microscopy and by the indirect immunofluorescent staining method with HLA-Dr antibody. The infiltration of eosinophilic neutrophils and granules was most prominent, with the occasional infiltration of mast cells, as shown by light microscopy. The infiltration of activated fibroblasts and Langerhans cells was also observed. Cells expressing HLA-Dr antigen were also markedly increased, as shown by the immunofluorescent method. These findings suggest that delayed hypersensitivity may, along with the processes of antigen presentation by HLA-Dr-expressing (including Langerhans) cells, contribute to the pathogenesis of giant papillary conjunctivitis.

[Ratings of perceived exertion in a group of children while swimming at different temperatures].

The purpose of this study was to compare the Ratings of Perceived Exertion (RPE) in children while swimming at different temperatures. Five healthy male swimmers, aged 10 to 12, swam tethered using the breast stroke at 32 degrees C, 25 degrees C and 20 degrees C water temperature in a flume, and biked at 25 degrees C air temperature in contrast with swimming. In swimming, the resistance started at 1.0 kg and increased in 1.0 kg increments up to the point of exhaustion, and in bicycling, started at 0.5 kp with 60 rpm and increased in 0.5 kp increments, respectively. The subjects swam or biked for 5 min during each period, with a rest of 10 to 20 min until they had returned to their resting HR level. The last exercise intensity was for 5 min with the maximal weight the subjects could support. The last min of VO2 and 30 sec of HR were measured during each exercise period. The subjects gave their RPE assessment at the end of each exercise. The relationships between %VO2max and HR were linear with a high correlation coefficient (r = 0.995-0.998) in both water and air. However, the slope of the %VO2max-HR line tended to shift to the right in colder water. Increased VO2 of swimming in cold water was largely attributed to shivering. The RPE increased exponentially against %VO2max in both water and air and deviated more from linearity against HR. The RPE in 25 degrees C water was lowest at all submaximal swimming. At maximal swimming, however, the RPE in the four conditions were much the same. It seemed that the RPE responded differently from HR in varying water temperatures.

Contribution of differentiated ratings of perceived exertion to overall exertion in women while swimming.

The purpose of this study was to identify, using multiple regression analysis, the contribution of differentiated ratings of perceived exertion to overall exertion (RPEO) in women while swimming. Ten female subjects swam at submaximal and maximal intensities and the variables measured included oxygen uptake (VO2), heart rate (fc), ventilation (VE), breathing frequency, tidal volume, blood lactate concentration ([la-]b), RPEO, and four differentiated RPE. These four differentiated RPE were cardiac frequency rating (RPEC), respiratory frequency rating (RPER), arm rating (RPE(arm)), and leg rating (RPE(leg)). These variables used the following equation based on VO2 - R = a + c.(S-b)n, where R was the response to increasing exercise intensity (S) and a, b, and c were constants. The exponents (n) of fc, VE and [la-]b were approximately 1.0, 2.0 and 3.3, respectively. The estimated exponents of RPEO, RPEC, RPER, RPE(arm) and RPE(leg) were approximately 2.4, 2.3, 2.2, 2.5 and 2.5, respectively. There was a highly significant relationship between the four differentiated RPE and their associated physiological responses. The results of this study showed that these interrelationships were clearly delineated. As the percentage maximal oxygen uptake (% VO2max) increased, the major contributing factor to RPEO changed. The RPEC was found to be the main contributing factor from 20% to 45% VO2max, but ceased to contribute beyond 50% VO2max. Above 45% VO2max, RPE(arm) was the major influence, and RPER was the secondary influence from 66% to 96% VO2max. The RPE(leg) was the secondary contributing factor only from 27% to 35% VO2max. It was concluded that differentiated RPE contribution was dependent upon the intensity of exercise in women while swimming.