Dynamic hip joint stiffness in individuals with total hip arthroplasty: relationships between hip impairments and dynamics of the other joints

Background

Little is known about hip joint stiffness during walking (dynamic joint stiffness) and the effect of hip impairments on biomechanical alterations of other joints in patients with total hip arthroplasty.

Methods

Twenty-four patients (mean age 61.7 years) who underwent unilateral (n = 12) or bilateral total hip arthroplasty (n = 12) and healthy subjects (n = 12) were recruited. In addition to kinematic and kinetic variables, dynamic hip joint stiffness which was calculated as an angular coefficient of linear regression of the plot of the hip flexion moment vs. hip extension angle during the late stance of gait, was measured. Group differences were compared using one-way ANOVA and Tukey's post-hoc test, and relationships between primary hip impairments and secondary gait impairments were found using partial correlation coefficients adjusted for gait speed and stride length.

Findings

Dynamic hip joint stiffness was 47% higher on the side with the more pronounced limp in patients with bilateral arthroplasty than in healthy controls. In the same patients, increased dynamic hip joint stiffness was significantly associated especially with increased ankle plantarflexion moment on the ipsilateral side. In patients with unilateral arthroplasty, decreased hip power was significantly related to increased ankle plantarflexor power, only on the non-operated side.

Interpretation

We found that dynamic hip joint stiffness was an important factor in assessing relationships between hip impairments and dynamics in other joints, especially in patients with bilateral total hip arthroplasty. The effects of altering hip joint stiffness on gait biomechanics need to be explored.     

Phosphorylated and cleaved TDP‐43 in ALS,FTLD and other neurodegenerative disorders and in cellular models of TDP‐43 proteinopathy

Transactivation response (TAR) DNA‐binding protein of Mr 43 kDa (TDP‐43) is a major component of the tau‐negative and ubiquitin‐positive inclusions that characterize amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration which is now referred to as FTLD‐TDP. Concurrent TDP‐43 pathology has been reported in a variety of other neurodegenerative disorders such as Alzheimer's disease, forming a group of TDP‐43 proteinopathy. Accumulated TDP‐43 is characterized by phosphorylation and fragmentation. There is a close relationship between the pathological subtypes of FTLD‐TDP and the immunoblot pattern of the C‐terminal fragments of phosphorylated TDP‐43. These results suggest that proteolytic processing of accumulated TDP‐43 may play an important role for the pathological process. In cultured cells, transfected C‐terminal fragments of TDP‐43 are more prone to form aggregates than full‐length TDP‐43. Transfecting the C‐terminal fragment of TDP‐43 harboring pathogenic mutations of TDP‐43 gene identified in familial and sporadic ALS cases into cells enhanced the aggregate formation. Furthermore, we found that methylene blue and dimebon inhibit aggregation of TDP‐43 in these cellular models. Understanding the mechanism of phosphorylation and truncation of TDP‐43 and aggregate formation may be crucial for clarifying the pathogenesis of TDP‐43 proteinopathy and for developing useful therapeutics.     

Surgical outcome of video-assisted thoracic surgery for acute thoracic empyema using pulsed lavage irrigation

Purpose  

The essential points of video-assisted thoracic surgery (VATS) for acute thoracic empyema are the decortication of thickened pleura, resection of necrotic tissues and fibrin blocks, and drainage. Pulsed lavage irrigation, which is commonly used in orthopedic surgery as a method of sufficiently performing the technique, was used under a thoracoscope to study the efficacy of the treatment for acute thoracic empyema.     

Sinus node artery-preserving superior transseptal approach: a simple technique

With the use of the superior transseptal approach during mitral valve surgery, good exposure of the mitral valve can be achieved with simple traction sutures, which minimize the risk of deformation of the mitral valve. For this reason, we routinely perform mitral valvoplasty using the superior transseptal approach; however, we, occasionally encounter cases that develop postoperative atrial dysrhythmia. We have therefore, devised a very simple technique for preservation of the sinus node artery in the superior transseptal approach, which is effective for reducing the incidence of postoperative sinus node dysfunction. In this technique, during incision of the dome of the left atrium, the sinus node artery is carefully dissected and preserved.     

Frequent activation of mitogen-activated protein kinase relative to Akt in extrahepatic biliary tract cancer

Background Lack of effective adjuvant therapy against advanced extrahepatic biliary tract carcinoma (BTC) requires that new therapeutic methods, such as molecular targeted therapy, be developed. The mitogen-activated protein kinase (MAPK) and Akt signaling pathways, which activate cell proliferation and suppress apoptosis, respectively, may function as important targets for such therapies. The aim of this study was to examine the expression patterns of phosphorylated MAPK (p-MAPK) and phosphorylated Akt (p-Akt) proteins in BTC cell lines and clinical specimens. Methods Expression of p-MAPK and p-Akt proteins in four human BTC cell lines and in frozen sections of 20 advanced extrahepatic BTC specimens was analyzed by Western blotting. Thirty formalin-fixed BTC specimens were immunohistochemically stained for p-MAPK and p-Akt using labeled streptavidin–biotin conjugates. Results Expression of p-MAPK was observed in three of four (75%) BTC cell lines, whereas no expression of p-Akt was observed. Twenty-three of 30 formalin-fixed specimens stained positive for p-MAPK (77%), whereas only 47% stained positively for p-Akt. Expression of p-MAPK relative to that of p-Akt was also seen more frequently in the frozen specimens. Conclusions The results of this study suggest that MAPK is activated more frequently than Akt in extrahepatic biliary tract carcinoma.     

Role of salivary tumour necrosis factor alpha in HIV-positive patients with oral manifestations

In HIV-1-infected patients, oral manifestations such as recurrent apthous ulcers are often seen. A total of 29 HIV-infected patients were examined to determine salivary tumour necrosis factor alpha (TNFalpha) concentrations by enzyme-linked immunosorbent assay, the amount of HIV-1 RNA copy by Amplicor HIV-1 Monitor test, number of CD4 cells by flow cytometry and oral manifestations by oral examination. TNFalpha concentration was significantly correlated with the amount of HIV-1 RNA, however, not with the number of CD4 cells in HIV-1-infected patients. Further, patients with oral manifestations showed significantly higher concentrations of TNFalpha in saliva and HIV-1 RNA copies in serum than those without oral manifestations. Following recovery from oral ulcers, TNFalpha concentration was decreased by half to 20 times lower than the level of that during ulcer incidence. Our results suggest that salivary TNFalpha is a good indicator for oral manifestations and HIV RNA amounts in HIV-1-infected patients.     

Examination of types of exposure and management methods for nurses in interventional radiology

Although a large number of studies have been done on exposure to operators and doctors during interventional radiology(IVR), there have been very few reports on nurses. This study was carried out to clarify the situation regarding exposure for nurses, and provides examples of how to estimate and manage. We measured space dose-rate distributions with an ionization survey meter, and personal exposure dose by a small fluorescent grass dosimeter(Dose Ace). The experimental results disclosed that there tended to be two types of exposure depending on the task performed. Head and neck(collar level)were associated with the highest exposure dose, which was observed in nurses assisting operators. Alternatively, knees showed the highest exposure dose, which was observed in nurses observing and assisting the patient. When estimation of skin equivalent exposure at the knees is needed, it can be calculated by using the value measured at the collar level. Furthermore, in estimating exposure dose, the directional and energy characteristics of personal dosimeters should be considered adequate. For radiation management, a circular protective sheet can be placed around the patient's lower area and a protective screen near the patient's head, and basic and practical education can be given. We concluded that these are highly useful for the personal monitoring of nurses engaged in IVR.