Risk factors affecting hip fracture patterns in an elderly Korean patient population

Hip fracture in the elderly patient population, particularly the Korean patient cohort, is one of the most serious complications of osteoporosis and currently increasing alongside age. In this study, we attempted to identify various factors that could either indicate the risk for an intertrochanteric or femoral neck fracture in an osteoporotic Korean hip fracture patient cohort ≥ 65 years old. A retrospective analysis of 168 patients was performed for those who underwent surgical treatment for either an intertrochanteric or femoral neck fracture at Daegu Catholic University Medical Center from January 2013 to December 2015. Inclusion criteria included patients who sustained a intertrochanteric or femoral neck fracture between the designated time frame, ≥65 years old, and of Korean ethnicity. Differences between the T-score and Z-score regarding bone mineral density (BMD) and the relationship between BMD and subtype of the fracture for the intertrochanteric (n = 92) and femoral neck fracture (n = 76) groups were obtained. Demographical factors (age, sex, weight, height, and body mass index [BMI]) were analyzed as potential risk factors for intertrochanteric or femoral neck fractures using software. Of the total 168 patients, mean weight and BMI values were found to be lower in the intertrochanteric fracture group (P = .033) compared to the femoral neck fracture group (P = .044). Additionally, Z-scores for the intertrochanteric fracture group were lower in the trochanter (P = .030), intertrochanteric (P = .029), and Ward's triangle (P = .029) regions. Regarding the intertrochanteric fracture group, the A3 subgroup showed lower T-scores of the trochanteric region than the A1 fracture subgroup (P = .010). In an elderly Korean hip patient cohort, lower body weight, BMI, and BMD Z-scores are correlated with a higher incidence of intertrochanteric fractures when compared to femoral neck hip fractures.

Efficacy of skin preparation solutions in patients with total knee replacement: A randomized controlled trial

PURPOSE

Surgical site infection following total knee replacement is considered as one of the most severe postoperative complications. The presence of bacteria at the surgical site is the most important risk factor and therefore it is essential to prevent infection through appropriate preoperative skin preparation. The purpose of this study was to examine the presence and type of native bacteria on the incision site and to assess which skin preparation is most effective to sterilize those native bacteria.

METHODS

Scrub-and-paint 2 step method was used for standard preoperative skin preparation. 150 patients who underwent total knee replacement were grouped into 3 groups- Group 1 (povidone-iodine scrub-and-paint), Group 2 (chlorhexidine gluconate paint after povidone-iodine scrub), and Group 3 (povidone-iodine paint after chlorhexidine gluconate scrub). 150 specimens of post-preparation swabs were obtained and cultured. To analyze the native bacteria at the total knee replacement incision site, 88 additional swaps were performed before skin preparation and cultured.

RESULTS

The positive rate of bacterial culture after skin preparation was 5.3% (8/150). Positive rates of the groups were 12% (6/50) in group 1, 2% (1/50) in group, 2 and 2% (1/50) in group 3 and positive rates of bacterial culture after skin preparation in group 2 and group 3 were lower than in group 1 (p = 0.037). Among the 55 patients who had positive bacterial culture prior to skin preparation, 26.7% (4/15) in group 1, 5.6% (1/18) in group 2, and 4.5% (1/22) in group 3 were positive. Group 1 showed 7.64 times higher positive bacterial culture rate after skin preparation than group 3 (p = 0.084).

CONCLUSION

During skin preparation prior to total knee replacement surgery, chlorhexidine gluconate paint after povidone-iodine scrub or povidone-iodine paint after chlorhexidine gluconate scrub had a superior effect on sterilizing native bacteria compared to povidone-iodine scrub-and-paint method.

Factors affecting the need of postoperative blood transfusion in elderly patients with intertrochanteric hip fracture

INTRODUCTION

We investigated the risk factors that increased the frequency of blood transfusions in elderly patients with intertrochanteric hip fractures to determine blood transfusion risk before surgery and to take selective precautionary measures in the group at high risk for transfusion to ensure safe surgery.

MATERIALS AND METHODS

We retrospectively reviewed the electronic medical records of 203 patients who underwent surgical fixation of intertrochanteric hip fractures from January 2015 to December 2020. We hypothesized that patient sex, age, body mass index, preoperative hemoglobin, preoperative platelet count, glomerular filtration rate (GFR), preoperative albumin level, American Society of Anesthesiologist score, intraoperative blood loss, duration of surgery, method of anesthesia, and time from injury to surgery would affect the need for blood transfusion. Student's t-test, Chi-squared test, and the one-way analysis of variance test were used to determine whether differences between variables in the transfusion and non-transfusion groups were significant.

RESULTS

Unstable fractures (P = 0.002), general anesthesia (P = 0.028), lower preoperative hemoglobin levels (P < 0.001), and lower GFRs (P < 0.001) were identified as related to blood transfusions in univariate analysis. In multivariate logistic analysis, the need for allogeneic blood transfusion in unstable fractures was approximately 2.949 times higher than in stable fractures (P = 0.009). The risk in general anesthesia patients was about 2.953 times higher than in spinal anesthesia patients (P = 0.007). In addition, the need for allogeneic blood transfusion increased by about 1.293 times as preoperative hemoglobin levels decreased by 1 g/dL (P = 0.017) and increased by about 1.017 times as the GFR decreased by 1 mL/min/1.7m2 (P = 0.006).

CONCLUSION

Low preoperative hemoglobin levels, low GFRs, general anesthesia, and unstable fractures in elderly patients with intertrochanteric hip fractures increased the risk of blood transfusion.

Prolonged ileus in traumatic pelvic ring injury patients who underwent arterial angio-embolization: A retrospective study

Paralytic ileus occurs in up to 18% of the patients with pelvic bone fractures. The aim of this study is to determine if massive bleeding requiring arterial angio-embolization is related with the duration of ileus in patients with traumatic pelvic ring injuries. This retrospective study included 25 patients who underwent arterial angio-embolization for traumatic pelvic ring injuries. Data were collected from prospectively maintained databases of two independent hospitals. Demographic characteristics (such as age, sex, body mass index, and Charlson Comorbidity Index), cause of trauma, and severity of pelvic injuries were similar in the non-prolonged and prolonged ileus groups. As expected, the prolonged ileus group had a significantly longer duration of ileus than the non-prolonged ileus group (8.0 ± 4.2 days vs 1.2 ± 0.4 days, respectively; P < .001). The mortality rate was higher in the prolonged ileus group (20% vs 0%), but it was not significantly different (P = .13). Interestingly, the prolonged ileus group received significantly higher amounts of packed red blood cell transfusions (6.1 ± 2.1 units vs 3.8 ± 2.5 units; P = .02). The amount of packed red blood cell transfusions was associated with a greater risk of prolonged ileus development (P = .03, odds ratio = 2.04, 95% confidence interval = 1.08-3.88). This study supports the idea that the duration of the ileus is related with the amount of bleeding caused by the traumatic pelvic ring injury. In order to prevent further complications, conservative treatments of the ileus should be considered.

A Review of Sarcopenia Pathophysiology, Diagnosis, Treatment and Future Direction

Sarcopenia is a progressive and generalized loss of skeletal muscle mass and function. The prevalence of sarcopenia was reported to be up to 29% in older persons in the community healthcare setting. Sarcopenia diagnosis is confirmed by the presence of low muscle mass plus low muscle strength or low physical performance. Sarcopenia management options include non-pharmacological and pharmacological approaches. Non-pharmacological approaches include resistance exercise and adequate nutrition. Of the two, resistance exercise is the standard non-pharmacological treatment approach for sarcopenia with significant positive evidence. Some dietary approaches such as adequate intake of protein, vitamin D, antioxidant nutrients, and long-chain polyunsaturated fatty acid have been shown to have positive effects against sarcopenia. Currently, no specific drugs have been approved by the Food and Drug Administration for the treatment of sarcopenia. However, several agents, including growth hormone, anabolic or androgenic steroids, selective androgenic receptor modulators, protein anabolic agents, appetite stimulants, myostatin inhibitors, activating II receptor drugs, β-receptor blockers, angiotensin-converting enzyme inhibitors, and troponin activators, are recommended and have been shown to have variable efficacy. Future research should focus on sarcopenia biological pathway and improved diagnostic approaches such as biomarkers for early detection, development of consistently pre-eminent treatment methods for severe sarcopenia patients, and establishing sensitive measures for predicting sarcopenia treatment response.

The natural trends of C-reactive protein after hip arthroplasty for femoral neck fracture without infection

The aim of this study was to estimate the degree of normalization of C-reactive protein (CRP) at 2-weeks and 4-weeks after hip arthroplasty after femoral neck fracture. We also wished to determine whether the degree of CRP normalization differs after total hip arthroplasty (THA) compared to bipolar hemiarthroplasty (BH). We also wanted to analyze the patient factors that may influence CRP normalization.We conducted a retrospective study of 135 patients who had undergone THA (32 cases) or BH (103 cases) for femoral neck fracture by single surgeon from January 2015 to December 2019. We analyzed CRP levels during the preoperative period, the early postoperative period, the 2-week postoperative period, and the 4-week postoperative period.In THA, CRP was normalized in 4 patients (12.5%) and in 15 patients (46.9%) within 2-weeks and 4-weeks after surgery, respectively. In BH, CRP was normalized in 16 patients (15.5%) and in 52 patients (50.5%) within 2-weeks and 4-weeks after surgery, respectively. There were no statistical differences between THA and BH. Compared to women, men were 3.78 (95% confidence interval, 1.05-13.63) times less likely to have normalized CRP at 2-weeks after surgery (P = .042). Compared to women, men were 3.01 (95% confidence interval, 1.44-6.27) times less likely to have normalized CRP at 4-weeks after surgery (P = .003).Only 50% of patient's CRP level was normalized during 4-week postoperative period. In men, CRP levels were significantly higher than women in whole period. In the case of THA, the CRP level was higher only in early postoperative period compared to BH, and there was no difference since then.

Sympathetic predominance before tourniquet deflation is associated with a reduction in arterial blood pressure after tourniquet deflation during total knee arthroplasty

High dependency of arterial blood pressure (ABP) on enhanced sympathetic activity, which maintains vascular tone, leads to hypotension after hemodynamic insults that blunt the sympathetic activity. Therefore, we hypothesized that sympathovagal balance before tourniquet deflation (TD) determines the extent of a reduction in ABP after TD during total knee arthroplasty (TKA). Fifty-four hypertensive female patients undergoing TKA under spinal anesthesia were analyzed. The sympathovagal balance [low-to-high frequency ratio of heart rate variability (LF/HF)] before TD was defined as (LF/HF during 5 min before TD-preanesthetic LF/HF)/preanesthetic LF/HF (%). An increase in its value represents a shift in sympathovagal balance toward sympathetic predominance. The percent change in the mean ABP (MAP) after TD was defined as (minimum MAP during 10 min after TD-averaged MAP during 5 min before TD)/averaged MAP during 5 min before TD (%). Simple linear regression was performed to assess the correlation between the sympathovagal balance before TD and change in MAP after TD. The correlation was also assessed by multiple linear regression controlling for age, duration of tourniquet inflation, and spinal anesthesia-induced hypotension. Thirty-two minutes (on average) after tourniquet inflation, the MAP was decreased by 12.1 (-3.0 to 47.9) % [mean (range)] upon TD (P<0.001). The sympathovagal balance before TD was negatively proportional to the change in MAP after TD in both simple and multiple linear regression models (R2=0.323 and 0.340, P<0.001). A shift in sympathovagal balance toward sympathetic predominance before TD is associated with a decrease in ABP after TD.

The advantage of navigation for knee with lateral femoral bowing in total knee arthroplasty

PURPOSE

We have analyzed the surgical outcomes of primary total knee arthroplasty (TKA) using computer-assisted (CA) navigation in terms of postoperative coronal alignment depending on preoperative lateral femoral bowing.

METHODS

We conducted a retrospective study of patients who have undergone navigated primary TKA from January 2016 through January 2020. Two hundred and ninety-nine cases with lateral femoral bowing of 3° or less were assigned to group 1, 95 cases of lateral femoral bowing between 3° and 5° were assigned to group 2, and 89 cases with lateral femoral bowing of more than 5° were assigned to group 3. The postoperative mechanical hip-knee-ankle (mHKA) angle was measured from scanograms, which were taken 3 months after surgery. The appropriate range of coronal alignment was set as 0 ± 3°.

RESULTS

The number of outliers of mHKA occurred was 31 cases (10.4%) in group 1, 17 cases (17.9%) in group 2, and 17 cases (19.1%) in group 3. There was a significant correlation between the degree of lateral femoral bowing and the occurrence rate of mHKA outliers. Multiple variables logistic regression analysis showed occurrence rate of outliers in group 3 to be 2.04 times higher than group 1. After adjusting the patient's age, sex, body mass index, and preoperative HKA deformity, the occurrence rate of outliers in group 3 was still 1.96 times higher than group 1.

CONCLUSION

The benefit of CA navigation during TKA in obtaining coronal alignment within 0 ± 3° may be lessened when the preoperative lateral femoral bowing is severely advanced.

Results of primary THA using 36 mm femoral heads on first-generation highly cross-linked polyethylene in patients less than 60 years of age: Minimum 10-year follow-ups

PURPOSE

Long-term results of total hip arthroplasty (THA) using highly cross-linked polyethylene (HXLPE) and metal femoral head with more than 10 years of follow-up have already been reported. However, most studies included results with a head size of 28 mm that could affect wear rates. The aim of this study was to evaluate the results of 36-mm metallic femoral heads on first-generation HXLPE in patients less than 60 years of age with a minimum follow-up of 10 years.

METHODS

Retrospective analysis included 54 cases from 47 patients. The mean age at the time of surgery was 47.22 years and the mean follow-up period was 131.04 months. Porous-coated cementless acetabular cups (Trilolgy®; Zimmer Inc., Warsaw, Indiana, USA) and HXLPE acetabular liners (Longevity®; Zimmer Inc.) were used for all cases. Acetabular cup abduction angles, anteversion angles, and wear rates of liner were measured using polyWare pro 3D distal version 5.10.

RESULTS

The average modified Harris hip score at the final follow-up was 88.48 (range 80-96). Average Merle d'Aubigne and Postel score was 15.57 (range 14-18). There was no acetabular cup or femoral stem failing due to aseptic loosening. The average steady-state wear rate determined using radiographs taken at 1 year postoperatively and at the latest follow-up was 0.053 ± 0.025 mm/year. There were no statistically significant differences in liner wear rate with respect to age, variety of the femoral stem, or liner thickness.

CONCLUSION

Results of THA with 36-mm metallic femoral heads on first-generation HXLPE in patients less than 60 years of age were satisfactory.

Sleep Disturbance Strongly Related to the Development of Postoperative Delirium in Proximal Femoral Fracture Patients Aged 60 or Older

Purpose

Post-fracture sleeping disorders can lead to a deterioration of mental and physical health and delay recovery to pre-fracture status. Here, an analysis was conducted to determine if sleep disturbance is a risk factor for delirium in patients older than 60 years of age with surgically treated proximal femoral fractures.

Materials and Methods

This retrospective study included 316 patients with surgically treated proximal femoral fractures between January 2014 and December 2016; 33 patients were removed from analysis due to exclusion criteria. Confirmation of delirium was made by a neurologist upon consultation for cognitive impairment and sleeping disorders were confirmed by a doctor or nurse based on the Pittsburgh sleep quality index. Potential risk factors other than a sleep disorder (e.g., history of cognitive impairment, medical illness, preoperational levels of albumin and hemoglobin, transfusion) were also analyzed as variables for the development of delirium.

Results

The sensitivity and specificity of a sleeping disorder as a risk factor for the development of delirium were 0.75 and 0.76, respectively; the positive and negative predictive values were 0.64 and 0.93, respectively. A sleeping disorder was significantly related to the development of the delirium (odds ratio adjusted for age, sex and body mass index was 5.78, P<0.01). In those with a history of cognitive impairment, the adjusted odds ratio for the development of delirium was 6.03 (P<0.01).

Conclusion

Sleeping disorders occurring after a surgically repaired proximal femoral fracture in patients 60 years of age or older could be an independent predictive factor of delirium.

Preoperative Temporary Discontinuation of Aspirin Medication Does Not Increase the Allogeneic Transfusion Rate and Blood Loss in Primary Total Hip Arthroplasty

Purpose

This study aims to determine whether preoperative temporary discontinuation of aspirin (100 mg/d) use is a safe procedure does not increase blood loss and the need for transfusion after total hip arthroplasty (THA).

Materials and Methods

This study retrospectively reviewed 219 patients who underwent consecutive primary THA from January 2012 to December 2018. They were divided into the experimental group (42 cases) that discontinued aspirin intake 7 days before surgery and the control group (150 cases) that had no history of use of antiplatelet agents. To compare initial blood loss between the two groups, we analyzed the changes hemoglobin (Hb) levels and hematocrit values measured preoperatively and in lowest values measured during three days after surgery. In addition, transfusion rate was compared within the first two postoperative weeks between the two groups. A multiple logistic regression was performed to assess the association of transfusion with age, gender, use of antiplatelet agents, preoperative anesthetic risk, body weight and preoperative Hb.

Results

No statistically significant difference was found in the changes in lowest Hb level (P=0.30) and hematocrit value (P=0.14) measured preoperatively and for three days after surgery between the experimental group and the control group. There was no statistically significant association between transfusion and the use of antiplatelet agents, and preoperative Hb level was identified as a factor that affected the need for transfusion (odds ratio, 0.427; P=0.001).

Conclusion

Preoperative temporary discontinuation of aspirin use for 7 days before surgery did not increase initial blood loss after THA and the need for transfusion in the first two postoperative weeks compared to patients with no history of use of antiplatelet agents.

Effects of Dangguixu-san on acute lateral ankle sprain: study protocol for a randomized controlled trial

BACKGROUND

Ankle sprain is a common musculoskeletal injury. In Korean medicine, blood stasis is thought to be the main cause of pain and swelling in patients with ankle sprain. Dangguixu-san (DS), a herbal extract, is widely used in Korean medicine for the treatment of traumatic ecchymosis and pain by promoting blood circulation and relieving blood stasis. However, the effects of DS on ankle sprain have not been evaluated in a randomized clinical trial. Here, we describe the protocol for a randomized controlled trial that will evaluate the efficacy and safety of DS for the treatment of ankle sprain.

METHODS/DESIGN

In this randomized, double-blinded, placebo-controlled, parallel-arm clinical trial with a 1:1 allocation ratio, participants (n = 48) with acute lateral ankle sprain (ALAS) that occurred within 72 h before enrollment will be randomly assigned to a DS (n = 24) or a placebo (n = 24) group. Both groups will receive acupuncture treatment once a day for 5 days a week (excluding Saturday and Sunday) and the trial medication (DS/placebo capsule) three times a day for seven consecutive days. The primary outcome measure will be pain relief evaluated using a Visual Analog Scale (VAS). Secondary outcome measures will include Foot and Ankle Outcome Scores (FAOS), edema, European Quality of Life Five-Dimension-Five-Level Scale (EQ-5D-5 L) scores, and the number of recurrent ankle sprains. VAS, FAOS, edema, and EQ-5D-5 L scores will be recorded before, at the end of, and at 4 weeks after treatment completion. EQ-5D-5 L scores will be additionally recorded at 26 weeks after treatment completion. The number of recurrent ankle sprains will be recorded at 4, 8, 12, and 26 weeks after treatment completion.

DISCUSSION

This study is expected to provide evidence regarding the efficacy, safety, and usefulness of DS for the treatment of ALAS.

TRIAL REGISTRATION

cris.nih.go.kr, registration number: KCT 0002374 . Registered on 11 July, 2017 and approved by the Ministry of Food and Drug Safety (registration number, 31244).

Relationship between Lateral Femoral Bowing and Varus Knee Deformity Based on Two-Dimensional Assessment of Side-to-Side Differences

Purpose

The objective was to evaluate the relationship between side-to-side differences of lateral femoral bowing and varus knee deformity based on two-dimensional (2D) assessment in unilateral total knee arthroplasty (TKA).

Materials and Methods

A total of 143 patients with varus knee osteoarthritis who underwent unilateral TKA were enrolled. We evaluated the side-to-side differences of the frontal lower limb alignment by assessing lateral femoral bowing, anatomical medial distal femoral angle, and anatomical medial proximal tibial angle (aMPTA).

Results

The average values of all anatomical indices were significantly different between the operated side and the non-operated side (p＜0.05). The side-to-side difference in hip knee ankle (HKA) angle had a statistically significant correlation with that in lateral femoral bowing (intraclass correlation coefficient, 0.259; p=0.002) and that in aMPTA. Linear regression analysis showed 0.199° of side-to-side difference in lateral femoral bowing was associated with 1° of side-to-side difference in bilateral HKA angle.

Conclusions

The side-to-side difference in lateral femoral bowing showed a tendency to increase in proportion to varus knee deformity based on 2D assessment in unilateral TKA patients.

The effects of Kinesiotape on acute lateral ankle sprain: study protocol for a randomized controlled trial

Background

Ankle sprains are some of the most frequent injuries of the musculoskeletal system. However, there is no substantive evidence supporting which treatment strategy is superior. Taping with Kinesiotape (KT) is a new method that is used as an alternative to the more established taping and bracing techniques used for the prophylaxis and treatment of ankle sprains. The aim of this study is to examine the efficacy of KT on ankle sprain by comparing acupuncture combined with KT (AcuKT) with acupuncture alone in patients with acute lateral ankle sprains.

Methods/design

This study is a prospective, multi-center (DongShin University Gwangju Oriental Hospital, DongShin University Mokpo Oriental Hospital, and KyungHee Korean Medicine Hospital), outcome assessor-blinded, randomized controlled clinical trial with a 1:1 allocation ratio. Participants (n = 60) with a lateral ankle sprain occurring within 1 week of the study will be randomly assigned to either an acupuncture group (n = 10 at each center (total n = 30)) or an AcuKT group (n = 10 at each center (total n = 30)). The acupuncture group will receive acupuncture treatment at ST36, ST41, BL60, BL62, KI3, KI6, GB39, and GB40 once per day, 5 days per week (excluding Saturday and Sunday) for 1 week. The AcuKT group will receive acupuncture treatment at ST36, ST41, BL60, BL62, KI3, KI6, GB39, and GB40 and the ankle meridian tendino-musculature and a figure-of-eight shape form of KT treatment once per day, 5 days per week (excluding Saturday and Sunday) for 1 week. The primary outcome will be pain evaluation assessed according to a Visual Analogue Scale (VAS), while Foot and Ankle Outcome Score (FAOS), edema, European Quality of Life Five Dimension-Five Level Scale (EQ-5D-5 L) score, and number of recurrent ankle sprains will be considered as secondary outcome measures. VAS, FAOS, and edema measurements will be performed at baseline (before intervention), 5 days after the first intervention (i.e., at the end of the intervention), and 4 weeks after the completion of intervention. EQ-5D-5 L measurements will be conducted at baseline, 5 days after the first intervention, 4 weeks after the completion of intervention, and 26 weeks after the completion of intervention. The number of recurrent ankle sprains will be determined at 4, 8, 12, and 26 weeks after the completion of the intervention.

Discussion

This study will provide data regarding the efficacy of KT for the treatment of acute lateral ankle sprain. The results may lead to insights into the usefulness of KT in the treatment of acute lateral ankle sprain.

Trial registration

cris.nih.go.kr, ID: KCT0002257. Registered on 27 February 2017, and approved by the Ministry of Food and Drug Safety (Medical Device Clinical Trial Plan Approval #737).

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2527-5) contains supplementary material, which is available to authorized users.

Results of Total Hip Arthroplasty with 36-mm Metallic Femoral Heads on 1st Generation Highly Cross Linked Polyethylene as a Bearing Surface in Less than Forty Year-old Patients: Minimum Ten-year Results

Purpose

We evaluated long-term clinical and radiographic results in patients underwent primary total hip arthroplasty (THA) using 36-mm metallic femoral head and 1st generation highly cross-linked polyethylene among patients aged 40 years and less, with minimum 10 years follow-up.

Materials and Methods

We retrospectively reviewed 20 hips underwent primary THA by one hip surgeon using 36-mm femoral head and 1st generation highly cross-linked polyethylene from 2004 to 2006. Mean follow up was 131.55 months. Clinical follow-ups included functional measurements. And we evaluated post operative complications, prosthesis loosening, failure, and osteolysis. For radiologic evaluations, together with position of acetabular cup at 6 weeks later of postoperation, we separately calculated the penentrations of femoral heads into polyethylene liners during postoperation and one year later check-ups, and during one year later check-ups and final check-ups. Polywear pro3D 5.10 software was used to measure penetrations of femoral head.

Results

Mean acetabular cup inclination and anteversion were 49.02° and 10.19°, respectively. Mean thickness of the polyethylene liner at 45° was 6.44 mm. There were no major complications such as implant loosening or osteolysis, and one case of dislocation occurred. Average modified Harris hip score at final follow-up was 91, and Merle d'Aubigne and Postel scores 15 were or over. Average femoral head penetration of bedding wear was 0.170±0.039 mm/year. Steady-state wear rates was 0.059±0.006 mm/year.

Conclusion

Results of THA with 36-mm metallic femoral heads on 1st generation highly cross linked as a bearing surface in less than 40 year-old patients were satisfactory.

Assessing the quality of reports about randomized controlled trials of scalp acupuncture combined with another treatment for stroke

BACKGROUND

This study was designed to assess the quality of reporting on randomized controlled trials (RCTs) of scalp acupuncture for the treatment of stroke.

METHODS

The following 8 databases were systematically investigated from their inception to December 2015: PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, National Institute of Informatics Scholarly and Academic Information Navigator, National Digital Science Library, Korean Traditional Knowledge Portal, and Korean Studies Information Service System. RCTs utilizing scalp acupuncture as an intervention for stroke were selected, and the quality of reports was assessed based on the Consolidated Standards of Reporting Trials 2010 statement (CONSORT) and Standards for Reporting Interventions in Controlled Trials of Acupuncture 2010 (STRICTA). For each study, the overall quality score (OQS) of 13 CONSORT items, a combined key methodological index score (MIS) of 5 CONSORT items, and the OQS of 17 STRICTA items were measured.

RESULTS

The original reports of 63 RCTs were ultimately obtained, and the median CONSORT OQS was 7 (minimum 2, maximum 11). Particularly, the items 'trial design', 'sample size', 'ancillary analyses', and 'harms' had a positive rate of less than 10%. The median MIS was 1 (minimum 0, maximum 5), with 'allocation concealment and implementation' and 'intent-to-treat analysis (ITT) analysis' having a positive rate of less than 10%. The median STRICTA OQS was 11 (minimum 6, maximum 14), and only the items 'sample size' and 'intent-to-treat analysis' were reported, with a positive rate of less than 10%. The mean CONSORT OQS increased by approximately 0.81 for each 5-year period in which manuscripts were published (95% confidence interval: 0.43 to 1.19; p < 0.001). No variable was significantly associated with MIS in the ordinal regression model.

CONCLUSION

The quality of reports on RCTs investigating scalp acupuncture treatment for stroke was moderate to low. Furthermore, reporting of some items was either insufficient or inadequate in the majority of studies. In order to improve and standardize the quality of RCTs investigating scalp acupuncture for stroke, CONSORT and STRICTA guidelines should be utilized more frequently.

Assessing the quality of reports about randomized controlled trials of scalp acupuncture treatment for vascular dementia

BACKGROUND

This study aimed to evaluate the quality of reports about randomized controlled trials (RCTs) of scalp acupuncture (SA) for the treatment of vascular dementia (VD).

METHOD

A systematic search of reports published through to December 2015 was performed in eight databases. The quality of RCTs that used SA as an intervention for VD was evaluated based on the 2010 Consolidated Standards for Reporting of Trials (CONSORT) and 2010 Standards for Reporting Interventions in Controlled Trials of Acupuncture (STRICTA) guidelines. Thirteen items from the CONSORT guideline were scored to give an overall quality score (OQS, range 0-13), and a combined key methodological index score (MIS) (range 0-5) of five key methodological items was measured. The OQS of 17 items from the STRICTA guideline (range 0-17) was also measured.

RESULTS

In total, 26 reports were evaluated. The median OQS based on the CONSORT guideline was 8 (minimum 5, maximum 11), and "trial design," "sample size," "ancillary analyses," and "harms" had a positive rate of less than 10%. The median MIS was 2 (minimum 0, maximum 5), with "allocation concealment and implementation," "blinding," and "intent-to-treat analysis" having a positive rate of less than 15%. The median OQS based on the STRICTA guideline was 12 (minimum 8, maximum 14), with "extent to which treatment was varied (1c)," "number of needle insertions per subject per session (2a)," and "setting and context of treatment (4b)" having a positive rate of less than 10%.

CONCLUSIONS

The overall quality of reports on RCTs of SA treatment for VD was moderate to low. The quality of methodological items was markedly lower than that of other items. The CONSORT and STRICTA guidelines should be used more frequently to standardize the quality of RCT reports of SA treatment for VD.

Scalp acupuncture and electromagnetic convergence stimulation for patients with cerebral infarction: study protocol for a randomized controlled trial

BACKGROUND

Scalp acupuncture (SA) and repetitive transcranial magnetic stimulation (rTMS) are effective for treating cerebral infarction. This study aims to examine the efficacy and safety of SA and electromagnetic convergence stimulation (SAEM-CS), which was developed through collaboration between conventional medical physicians and doctors who practice traditional Korean medicine. SAEM-CS was designed to improve function in patients with cerebral infarction, compared to the improvement after conventional stroke rehabilitation, SA, and rTMS therapeutic approaches.

METHODS/DESIGN

This study is a prospective, outcome assessor-blinded, randomized controlled clinical trial with a 1:1:1:1 allocation ratio. Participants with motion or sensory disabilities caused by a first-time cerebral infarction (n = 60) that had occurred within 1 month of the study onset will be randomly assigned to control, SA, rTMS, or SAEM-CS groups. All groups will receive two sessions of conventional rehabilitation treatment per day. The SA group will receive SA on the upper limb area of MS6 and MS7 (at the lesional hemisphere) for 20 min, the rTMS group will receive low-frequency rTMS (LF-rTMS) treatment on the hot spot of the M1 region (motor cortex at the contralesional hemisphere) for 20 min, and the SAEM-CS group will receive LF-rTMS over the contralesional M1 region hot spot while receiving simultaneous SA stimulation on the lesional upper limb area of MS6 and MS7 for 20 min. SA, rTMS, and SAEM-CS treatments will be conducted once/day, 5 days/week (excluding Saturdays and Sundays) for 3 weeks, for a total of 15 sessions. The primary outcome will be evaluated using the Fugl-Meyer Assessment, while other scales assessing cognitive function, activities of daily living, walking, quality of life, and stroke severity are considered secondary outcome measures. Outcome measurements will be conducted at baseline (before intervention), 3 weeks after the first intervention (end of intervention), and 4 weeks after intervention completion.

DISCUSSION

This study aims to explore the efficacy and safety of SAEM-CS on cerebral infarction. Collaborative research combined traditional Korean and conventional medicines, which can be useful in developing new treatment technologies.

TRIAL REGISTRATION

KCT0001768 . Registered on 14 January 2016.

Current Concepts of Using Large Femoral Heads in Total Hip Arthroplasty

Instability and dislocation after total hip arthroplasty are the most common causes of revisions and major complications for failure of inserted prostheses, leading to a reduction in quality of life. Because the use of artificial femoral head sizes smaller than patient's own size is the important cause for dislocation, the use of large femoral head have increased. Femoral head sizes greater than 32 mm offer multiple advantages in physical function and activity levels of patients by improving hip stability, decreasing dislocation rate and increasing range of motion. However, various concerns are encountered including wear debris generation at the trunnion-bore interface and increases in frictional torque and stress over the component-bone interface when using larger head sizes. So, the use of femoral head sizes less than 40 mm is recommended.

Results of Primary Total Hip Arthroplasty Using 36 mm Femoral Heads on 1st Generation Highly Cross Linked Polyethylene in Patients 50 Years and Less with Minimum Five Year Follow-up

Purpose

We evaluated the clinical and radiographic midterm results of primary total hip arthroplasty (THA) using a 36 mm diameter femoral head on 1st generation highly cross-linked polyethylene (HXLPE) in patients 50 years and less with minimum five year follow-up.

Materials and Methods

We retrospectively reviewed 31 patients (41 hips) aged 50 years and less underwent primary THA with a 36 mm diameter femoral head on HXLPE between 2004 and 2010. Clinical follow-ups included specific measurements like modified Harris hip scores (HHS) and Merle d'Aubigne and Postel score. For radiologic evaluations, together with position of acetabular cup at six weeks later of postoperation, we separately calculated the penentrations of femoral head into polyethylene liners during postoperation and one year later check-ups, and during one year later check-ups and final check-ups.

Results

There were no major complications except for one case of dislocation. Average modified HHS at final follow-up was 88 (81-98), and Merle d'Aubigne and Postel scores were more than 15. Mean acetabular cup inclination and anteversion were 45.81°(36.33°-54.91°) and 13.26°(6.72°-27.71°), respectively. Average femoral head penetration of steady-state wear rate determined using radiographs taken at one-year postoperatively and at latest follow-up was 0.042±0.001 mm/year.

Conclusion

Based on minimum 5 years clinical results, we think 36 mm metal head coupling with HXLPE as the good alternate articulation surface when planning THA for patients aged 50 years and less.

A Liner Breakage in Total Hip Arthroplasty after Using 1st Generation Highly Cross Linked Polyethylene Mated against 36-mm Metal Head: A Case Report

It has been known the highly cross linked polyethylene (HXLPE) has an advantage of improved wear rate. However, the alteration in mechanical properties such as decreased tensile yield and fatigue strength make concerns about fragility of HXLPE. We experienced a case of HXLPE breakage. But, this case of liner breakage happened although patient belonged to normal BMI and proper acetabular cup position so called "safe zone" on radiographs. So, we report this case with reference review.

Proximal Femoral Shortening after Operation with Compression Hip Screws for Intertrochanteric Fracture in Patients under the Age of 60 Years

Purpose

We aimed to quantify proximal femoral shortening after operation with compression hip screws for intertrochanteric fracture in patients under the age of 60 years.

Materials and Methods

We followed 37 consecutive patients with intertrochanteric fractures treated with compression hip screws from March 2005 to February 2014. We designated the aspect of the fracture, a defect of the postero-medial wall, a defect of the lateral wall, and the degree of reduction as four potentially important factors we assumed would strongly affect proximal femoral shortening. We quantified proximal femoral shortening and compared the effects of above factors. We divided femoral shortening into two plane vectors; femoral offset in the horizontal plane and leg length discrepancy in the vertical plane. We measured shortening separately during two periods: during operation and after weight bearing (called dynamic compression).

Results

After bone union, the average femoral offset shortening was 5.45 mm. Patient groups with anatomic reduction and intact postero-medial wall showed lower femoral offset shortening than the respective opposite groups. As to functional score using modified Harris hip score, low femoral offset shortening group showed more 2.35 scores than high groups. None of the factors significantly affected leg length shortening.

Conclusion

We found that a stable medial buttress is involved in lower femoral offset shortening. Thus, surgeons need to attempt to recover the defect of the medial wall and to reduce anatomically when operating intertrochanteric fractures with compression hip screws.

Suppression of creep-regime dynamics in epitaxial ferroelectric BiFeO3 films

Switching dynamics of ferroelectric materials are governed by the response of domain walls to applied electric field. In epitaxial ferroelectric films, thermally-activated ‘creep’ motion plays a significant role in domain wall dynamics, and accordingly, detailed understanding of the system’s switching properties requires that this creep motion be taken into account. Despite this importance, few studies have investigated creep motion in ferroelectric films under ac-driven force. Here, we explore ac hysteretic dynamics in epitaxial BiFeO₃ thin films, through ferroelectric hysteresis measurements, and stroboscopic piezoresponse force microscopy. We reveal that identically-fabricated BiFeO₃ films on SrRuO₃ or La_0.67Sr_0.33MnO₃ bottom electrodes exhibit markedly different switching behaviour, with BiFeO₃/SrRuO₃ presenting essentially creep-free dynamics. This unprecedented result arises from the distinctive spatial inhomogeneities of the internal fields, these being influenced by the bottom electrode’s surface morphology. Our findings further highlight the importance of controlling interface and defect characteristics, to engineer ferroelectric devices with optimised performance.

Perforation of Surgical Gloves during Lower Extremity Fracture Surgery and Hip Joint Replacement Surgery

Purpose

To assess the frequencies and sites of surgical glove perforations in lower extremity fracture surgery and hip joint replacement (HJR) surgery. Additionally, we also studied the usefulness of an indicator system glove.

Materials and Methods

We assessed surgical glove perforations in 30 cases of lower extremity fracture surgery and 18 cases of HJR surgery conducted by one right handed 1st operator from April 2013 to July 2013. We assessed frequencies and sites of perforation in 152 gloves; 95 used in lower extremity fracture surgery and 57 used in HJR surgery. We studied the perforation rates and sites according to participants and operation types. Using the Biogel indicator system glove, which is well known as a fast indicator of glove perforation, we were also able to assess the time difference between operative participant detection of perforation and inspector nurse detection while observing in the operative field.

Results

There were 18 of 30 cases in lower extremity fracture surgeries and 12 of 18 cases in HJR surgeries which had more than one surgical glove perforation event. Of all 152 gloves used, perforation occurred in 15 of 57 gloves (26.3%) in HJR surgery and 23 of 95 gloves (24.2%) in lower extremity fracture surgery. Perforation occurred more frequently in operators than assistant doctors or scrub nurses. The most frequent perforation site was the second digit of the left hand. On average, the time difference between operative participant notice of perforation and inspector nurse notice of perforation was 20.6 seconds.

Conclusion

The perforation of surgical gloves happened in approximately one out of every four persons. Importantly, we noted a 37.0% prevalence of glove perforation in 1st operators. Considering that glove perforation is a critical factor responsible for intra-operative infection, surgeons must be conscious of the risk of surgical glove perforation and use double gloving regularly. Furthermore, indicator double gloving is recommended for fast detection of outer glove perforation.

Results of Primary Total Hip Arthroplasty with 36-mm Femoral Heads on Highly Cross-linked Polyethylene-Minimum Seven-years Follow-up

Purpose

We evaluate the clinical and radiographic midterm results of primary total hip arthroplasty (THA) using a 36 mm diameter femoral head on highly cross-linked polyethylene (minimum 7-year follow-up).

Materials and Methods

We retrospectively reviewed 73 patients (74 hips) that underwent primary THA with a 36 mm diameter femoral head on highly cross-linked polyethylene between July 2004 and February 2007. Clinical follow-ups included specific measurements like modified Harris hip scores (HHS) and Merle d'Aubigne and Postel score. For radiologic evaluations, together with position of acetabular cup at 6 weeks later of post-operation, we separately calculated the penentrations of femoral heads into polyethylene liners during post-operation and one year later check-ups, and during one year later check-ups and final check-ups.

Results

There were no complications except for one case of dislocation. Average modified HHS at final follow-up was 88±7.5 (range, 81-96), and Merle d'Aubigne and Postel scores were more than 15 (range, 15-18). Mean acetabular cup inclination and anteversion were 50.1°(range, 35°-58°) and 23.6°(range, 5°-38°), respectively. Average femoral head penetration during the first postoperative year was 0.071±0.034 mm/year, and steady-state wear rate determined using radiographs taken at one-year postoperatively and at latest follow-up was 0.051±0.022 mm/year. Average femoral head penetration during entire follow-ups was 0.058±0.013 mm/year.

Conclusion

Primary THA with a large diameter femoral head on highly cross-linked polyethylene was found to produce the results comparable to previous in vitro laboratory hip simulation studies. And we also find out good scores in terms of patient's functionality.

Is surgery necessary for femoral insufficiency fractures after long-term bisphosphonate therapy?

BACKGROUND

Prolonged use of bisphosphonates in patients with osteoporosis reportedly induces femoral insufficiency fractures. However, the natural course of these fractures and how to treat them remain unknown.

QUESTIONS/PURPOSES

We determined the rates of fracture displacement and subsequent operations of undisplaced insufficiency fractures of the femur in patients treated with prolonged bisphosphonate therapy.

PATIENTS AND METHODS

We retrospectively collected and reviewed the clinical course of 11 patients (14 fractures) who had been diagnosed as having an insufficiency fracture of the femur after prolonged use (mean, 4.5 years; range, 3-10 years) of bisphosphonate. All patients were women with a mean age of 68 years (range, 57-82 years). The fracture site was subtrochanteric in six and femoral shaft in eight. The minimum followup was 12 months (mean, 27 months; range, 12-60 months).

RESULTS

During the followup period, secondary displacement of the fracture occurred in five of the 14 fractures after a mean of 10 months (range, 1-19 months). Three fractures were treated with internal fixation using a compression hip screw and two with intramedullary nailing. Because five additional fractures were treated surgically owing to intractable pain, surgery was performed in 10 of 14 insufficiency fractures during the followup period. All 10 fractures healed during followup. The remaining four patients (four fractures) not undergoing any surgery had persistent pain.

CONCLUSIONS

Femoral insufficiency fractures after prolonged bisphosphonate therapy seldom healed spontaneously and most patients had surgery either for fracture displacement or persistent pain.

Morphology and adhesion of mesenchymal stem cells on PLLA, apatite and apatite/collagen surfaces

Biomimetic apatite/collagen composite coating, previously reported particularly with regard to its fabrication, characterization and interaction with osteoblast-like cells, has been investigated in this study to understand the response of human mesenchymal stem cells (hMSC) to such surface. PLLA films and PLLA films with apatite coating were compared with PLLA films with apatite/collagen composite coating. The hMSC morphology in response to such conditions was first observed using fluorescence microscopy. To further understand such cell-material interactions at a molecular level, integrin expression, actin assembly and vinculin-positive focal adhesion plaques were examined. Our results demonstrated that spreading of stem cells on the apatite/collagen composite surface was determined best among the three types of surfaces, followed by the apatite surface and then the PLLA control. Integrin expression on the apatite/collagen surface was higher than those on the apatite surface and PLLA surface. Immunostaining for vinculin and actin suggested that the composite coating on PLLA enhanced the formation of focal adhesion.

A predictive method for subsequent avascular necrosis of the femoral head (AVNFH) by observation of bleeding from the cannulated screw used for fixation of intracapsular femoral neck fractures

OBJECTIVES

To examine the validity of bleeding from the drill holes used for cannulated screw placement as a method for predicting any subsequent avascular necrosis of the femoral head (AVNFH) after the fixation of intracapsular femoral neck fractures.

DESIGN

Retrospective study.

SETTING

University hospital.

PARTICIPANTS

Forty-four patients (mean age, 51 years; range, 18-76 years) whose femoral neck fractures had been fixed with cannulated screws from March 1999 to January 2001 were enrolled in this study. The fractures were classified according to Garden and included 11 type I, 5 type II, 17 type III, and 11 type IV. The average delay between injury and surgery was 52 hours (< or =24 hours, 26; > or =24 hours, 18; range 7 to 504 hours). The follow-up period was more than 25 months (range, 25-57 months).

INTERVENTION

7.0 mm cannulated screws were used for fracture fixation. Three and 4 screws were used for fixation in 35 and 9 cases, respectively.

MAIN OUTCOME MEASUREMENTS

The presence or absence of blood drainage from the holes of the proximal cannulated screws was determined by an independent observer and defined as bleeding or no bleeding throughout a 5 minute observation period. According to those findings, patients were classified into 2 groups: the bleeding group (38 cases), and the nonbleeding group (6 cases). The validity of the relationship between the 2 groups and the development of AVNFH was evaluated according to the sensitivity, specificity, positive predictive value, and negative predictive value. A chi test was used for univariate analysis of the relationship between the related factors with the development of AVNFH.

RESULTS

The mean follow-up was 39 months (range, 25-57 months). AVNFH developed in 7 cases (16%). One patient of 38 in the bleeding group (2.6%) and all 6 patients in the nonbleeding group (100%) developed AVNFH. The sensitivity was 86%, specificity 100%, positive predictive value 100%, and negative predictive value 97%. Age (P < 0.734), sex (P < 0.587), the type of the fracture (P < 0.356), procedure interval (P < 0.398), the reduction status of the fracture site (P < 0.3849), the positions of the fixed screws (P < 0.2137), and the existence of osteoporosis (P < 0.4347) were not related to the development of AVNFH.

CONCLUSION

It seems that bleeding from the holes of proximal cannulated screws is a simple and accurate perfusion assessment technique for predicting the development of AVNFH after a femoral neck fracture. Given that assumption, primary arthroplasty might be an appropriate choice as a treatment method in a nonbleeding-group patient whose treatment choice is ambivalent or who might not be able to undergo additional surgery should he or she develop a subsequent AVNFH after internal fixation of femoral neck fracture.

Latent period best predicts acetabular cup failure after total hip arthroplasties in radiated hips

We retrospectively analyzed the prognostic factors related to the failure of acetabular components after total hip arthroplasties in radiated hips. Eighteen hips from 12 patients who had primary arthroplasties were followed up for a mean of 58 months (range, 20-139 months). The patients' age, total radiation dose, latent period, presence of infection, and the type of the acetabular component were examined as possible predictors of failure using the Cox proportional hazard regression. Multivariate analyses showed that a longer latent period was the most important risk factor for failure, increasing 1.72 times when the latent period was greater than 1 year, after adjusting for other predictors. The latent period might be helpful for clinicians in choosing a treatment method for patients.

LEVEL OF EVIDENCE

Prognostic study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Cementless Metasul metal-on-metal total hip arthroplasty in patients less than fifty years old

BACKGROUND

Durable results of total hip arthroplasty have been difficult to achieve in young patients. We reviewed the intermediate-term clinical and radiographic results in a series of active, higher-demand patients who were less than fifty years old when they underwent cementless total hip arthroplasty with the use of the Metasul metal-on-metal articulation.

METHODS

Seventy total hip arthroplasties were performed in sixty-two patients who were younger than fifty years of age (average age, thirty-seven years). Two patients (two hips) had had a resection arthroplasty because of deep infection less than five years postoperatively and were excluded. Sixty patients (sixty-eight hips) were available for complete clinical and radiographic analysis after a mean duration of follow-up of seven years.

RESULTS

The mean preoperative Harris hip score of 49 points improved to 95 points at the time of final follow-up; fifty-six patients (93%) had an excellent result. No component was seen to be loose radiographically at the time of final follow-up. Only one focal area of pelvic osteolysis in one patient and two small focal areas of femoral osteolysis in another patient were identified. The hip with focal pelvic osteolysis underwent revision surgery with a liner change and bone-grafting of the osteolytic lesion around a stable component.

CONCLUSIONS

At a mean of seven years after arthroplasties with a Metasul metal-on-metal articulation, there was a low rate of osteolysis and aseptic loosening in this group of young patients. However, additional follow-up is necessary to determine any possible long-term deleterious effects associated with this metal-on-metal articulation.

Ultrastructure of the Z-organ and Parts of the Female Genital Tract in Xiphinema coxi coxi

Ultrastructure of the Z-organ and associated apophyses in Xiphinema coxi coxi was studied by transmission electron microscopy to determine their structural origin and relationship with other parts of the genital tract. The Z-organ of X. coxi coxi is oval-shaped, ca. 30 microm long and 16 microm wide. It is clearly distinguished from the other parts of the female genital tract by its thick muscular outer wall, epithelium-lined lumen, and 4-5 centrally located apophyses. Each apophysis is continuous with the epithelial lining of the Z-organ, suggesting that it originated from epithelium. The apophyses appear as thickened and densely folded masses forming numerous interlaced pores and (or) chambers containing mucous-like materials and electron-dense crystals. These apophyses are characteristic of a typical Z-organ; no globular structures characteristics of the pseudo-Z-organ were observed. The thickness of the muscular layer of the oviduct and uterus varied with position. The overall Z-organ ultrastructure of this study, including body wall and internal apophyses, was comparable to the typical Z-organ of X. ifacolum. This suggests that X. coxi coxi should be classified as a Xiphinema species that contains the typical Z-organ.

Integrin-dependent human macrophage migration induced by oscillatory electrical stimulation

Electrical stimulation has been used to promote wound healing. The mechanisms by which such stimulation could interact with biological systems to accelerate healing have not been elucidated. One potential mechanism could involve stimulation of macrophage migration to the site of a wound. Here we report that oscillatory electric fields induce human macrophage migration. Macrophages exposed to a 1 Hz, 2 V/cm field show an induced migration velocity of 5.2+/-0.4 x 10(-2) microm/min and a random motility coefficient of 4.8+/-1.4 x 10(-2) microm2/min on a glass substrate. Electric field exposure induces reorganization of microfilaments from ring-like structures at the cell periphery to podosomes that are confined to the contact sites between cell and substrate, suggesting that the cells are crawling on glass. Treatment of cells with monoclonal antibodies directed against beta2-integrins prior to field exposure prevents cell migration, indicating that integrin-dependent signaling pathways are involved. Electric fields cause macrophage migration on laminin or fibronectin coated substrates without inducing podosome formation or changes in cellular morphology. The migration velocity is not significantly altered but the random movement is suppressed, suggesting that cell movements on a laminin- or fibronectin-coated surface are not mediated by cell crawling. It is suggested that electric field-induced macrophage migration utilizes several modes of cell movement, including cell crawling and possibly cell rolling.

Mild spherocytosis and altered red cell ion transport in protein 4. 2-null mice

Protein 4.2 is a major component of the red blood cell (RBC) membrane skeleton. We used targeted mutagenesis in embryonic stem (ES) cells to elucidate protein 4.2 functions in vivo. Protein 4. 2-null (4.2(-/-)) mice have mild hereditary spherocytosis (HS). Scanning electron microscopy and ektacytometry confirm loss of membrane surface in 4.2(-/-) RBCs. The membrane skeleton architecture is intact, and the spectrin and ankyrin content of 4. 2(-/-) RBCs are normal. Band 3 and band 3-mediated anion transport are decreased. Protein 4.2(-/-) RBCs show altered cation content (increased K+/decreased Na+)resulting in dehydration. The passive Na+ permeability and the activities of the Na-K-2Cl and K-Cl cotransporters, the Na/H exchanger, and the Gardos channel in 4. 2(-/-) RBCs are significantly increased. Protein 4.2(-/-) RBCs demonstrate an abnormal regulation of cation transport by cell volume. Cell shrinkage induces a greater activation of Na/H exchange and Na-K-2Cl cotransport in 4.2(-/-) RBCs compared with controls. The increased passive Na+ permeability of 4.2(-/-) RBCs is also dependent on cell shrinkage. We conclude that protein 4.2 is important in the maintenance of normal surface area in RBCs and for normal RBC cation transport.

Transmembrane calcium influx induced by ac electric fields

Exogenous electric fields induce cellular responses including redistribution of integral membrane proteins, reorganization of microfilament structures, and changes in intracellular calcium ion concentration ([Ca2+]i). Although increases in [Ca2+]i caused by application of direct current electric fields have been documented, quantitative measurements of the effects of alternating current (ac) electric fields on [Ca2+]i are lacking and the Ca2+ pathways that mediate such effects remain to be identified. Using epifluorescence microscopy, we have examined in a model cell type the [Ca2+]i response to ac electric fields. Application of a 1 or 10 Hz electric field to human hepatoma (Hep3B) cells induces a fourfold increase in [Ca2+]i (from 50 nM to 200 nM) within 30 min of continuous field exposure. Depletion of Ca2+ in the extracellular medium prevents the electric field-induced increase in [Ca2+]i, suggesting that Ca2+ influx across the plasma membrane is responsible for the [Ca2+]i increase. Incubation of cells with the phospholipase C inhibitor U73122 does not inhibit ac electric field-induced increases in [Ca2+]i, suggesting that receptor-regulated release of intracellular Ca2+ is not important for this effect. Treatment of cells with either the stretch-activated cation channel inhibitor GdCl3 or the nonspecific calcium channel blocker CoCl2 partially inhibits the [Ca2+]i increase induced by ac electric fields, and concomitant treatment with both GdCl3 and CoCl2 completely inhibits the field-induced [Ca2+]i increase. Since neither Gd3+ nor Co2+ is efficiently transported across the plasma membrane, these data suggest that the increase in [Ca2+]i induced by ac electric fields depends entirely on Ca2+ influx from the extracellular medium.

Estradiol induces the calcium-dependent translocation of endothelial nitric oxide synthase

Although estrogen is known to stimulate nitric oxide synthesis in vascular endothelium, the molecular mechanisms responsible for this effect remain to be elucidated. Using quantitative immunofluorescence imaging approaches, we have investigated the effect of estradiol on the subcellular targeting of endothelial nitric oxide synthase (eNOS) in bovine aortic endothelial cells. In unstimulated endothelial cells, eNOS is predominantly localized at the cell membrane. Within 5 min after the addition of estradiol, most of the eNOS translocates from the membrane to intracellular sites close to the nucleus. On more prolonged exposure to estradiol, most of the eNOS returns to the membrane. This effect of estradiol is evident at a concentration of 1 pM, and a maximal estradiol effect is seen at a concentration of 1 nM. Neither progesterone nor testosterone has any effect on eNOS distribution. After estradiol addition, a transient rise in intracellular Ca2+ concentration precedes eNOS translocation. Both the Ca2+-mobilizing and eNOS-translocating effects of estradiol are completely blocked by the estrogen receptor antagonist ICI 182,780, and the intracellular Ca2+ chelator 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) prevents estradiol-induced eNOS translocation. Use of the nitric oxide-specific dye diaminofluorescein shows that estradiol treatment increases nitric oxide generation by endothelial cells; this response is blocked by ICI 182,780 and by the eNOS inhibitor Nomega-nitro-L-arginine. These results show that estradiol induces subcellular translocation of eNOS by a rapid, Ca2+-dependent, receptor-mediated mechanism, and they suggest a nongenomic role for estrogen in the modulation of NO-dependent vascular tone.

Membrane dynamics of the water transport protein aquaporin-1 in intact human red cells

Aquaporin-1 (AQP1) is the prototype integral membrane protein water channel. Although the three-dimensional structure and water transport function of the molecule have been described, the physical interactions between AQP1 and other membrane components have not been characterized. Using fluorescein isothiocyanate-anti-Co3 (FITC-anti-Co3), a reagent specific for an extracellular epitope on AQP1, the fluorescence photobleaching recovery (FPR) and fluorescence imaged microdeformation (FIMD) techniques were performed on intact human red cells. By FPR, the fractional mobility of fluorescently labeled AQP1 (F-alphaAQP1) in the undeformed red cell membrane is 66 +/- 10% and the average lateral diffusion coefficient is (3.1 +/- 0.5) x 10(-11) cm2/s. F-alphaAQP1 fractional mobility is not significantly affected by antibody-induced immobilization of the major integral proteins band 3 or glycophorin A, indicating that AQP1 does not exist as a complex with these proteins. FIMD uses pipette aspiration of individual red cells to create a constant but reversible skeletal density gradient. F-alphaAQP1 distribution, like that of lipid-anchored proteins, is not at equilibrium after microdeformation. Over time, approximately 50% of the aspirated F-alphaAQP1 molecules migrate toward the membrane portion that had been maximally dilated, the aspirated cap. Based on the kinetics of migration, the F-alphaAQP1 lateral diffusion coefficient in the membrane projection is estimated to be 6 x 10(-10) cm2/s. These results suggest that AQP1 lateral mobility is regulated in the unperturbed membrane by passive steric hindrance imposed by the spectrin-based membrane skeleton and/or by skeleton-linked membrane components, and that release of these constraints by dilatation of the skeleton allows AQP1 to diffuse much more rapidly in the plane of the membrane.

Regulation of band 3 rotational mobility by ankyrin in intact human red cells

Ankyrin mutations and combined spectrin and ankyrin deficiency are prominent features of red blood cells (RBCs) in patients with hereditary spherocytosis (HS). Band 3 is the most abundant integral protein in the human RBC membrane. Previous studies have shown that the lateral mobility, but not the rotational mobility, of band 3 is increased in RBCs from patients with severe autosomal recessive HS and selective spectrin deficiency. These observations are consistent with the steric hindrance model of lateral mobility restriction. Here we use the fluorescence photobleaching recovery and polarized fluorescence depletion techniques to measure the lateral and rotational mobility of band 3 in intact RBCs from six patients with HS, ankyrin mutations, and combined spectrin and ankyrin deficiency. As predicted by the steric hindrance model, the lateral diffusion rate of band 3 is greater in spectrin- and ankyrin-deficient RBCs than in control cells, and the magnitude of the increase correlates with the degree of spectrin deficiency. Unlike RBCs from patients with HS and selective spectrin deficiency, however, HS RBCs with ankyrin mutations exhibit a marked increase in band 3 rotational diffusion. The magnitude of the increase correlates inversely with the ankyrin/band 3 ratio and with the fraction of band 3 retained in the membrane skeleton following detergent extraction. These data suggest that ankyrin deficiency relaxes rotational constraints on the major (slowly rotating) population of band 3 molecules. Increases in band 3 rotation could be due to release of band 3 from low-affinity binding sites on ankyrin.

Receptor-regulated translocation of endothelial nitric-oxide synthase

The endothelial nitric-oxide synthase (eNOS) is activated by transient increases in intracellular Ca2+ elicited by stimulation of diverse receptors, including bradykinin B2 receptors on endothelial cells. eNOS and B2 receptors are targeted to specialized signal-transducing domains in the plasma membrane termed plasmalemmal caveolae. Targeting to caveolae facilitates eNOS activation following receptor stimulation, but in resting cells, eNOS is tonically inhibited by its interactions with caveolin, the scaffolding protein in caveolae. We used a quantitative approach exploiting immunofluorescence microscopy to investigate regulation of the subcellular distribution of eNOS in endothelial cells by bradykinin and Ca2+. In resting cells, most of the eNOS is localized at the cell membrane. However, within 5 min following addition of bradykinin, nearly all the eNOS translocates to structures in the cell cytosol; following more protracted incubations with bradykinin, most of the cytosolic enzyme subsequently translocates back to the cell membrane. The bradykinin-induced internalization of eNOS is completely abrogated by the intracellular Ca2+ chelator BAPTA; conversely, Ca2+-mobilizing drugs and agonists promote eNOS translocation. These results establish that eNOS targeting to the membrane is labile and is subject to receptor-regulated Ca2+-dependent reversible translocation, providing another point for regulation of NO-dependent signaling in the vascular endothelium.

Temporal synthesis of band 3 oligomers during terminal maturation of mouse erythroblasts. Dimers and tetramers exist in the membrane as preformed stable species

Band 3, the anion transport protein of the erythrocyte membrane, exists in the membrane as a mixture of dimers (B3D) and tetramers (B3T). The dimers are not linked to the skeleton and constitute the free mobile band 3 fraction. The tetramers are linked to the skeleton by their interaction with ankyrin. In this report we have examined the temporal synthesis and assembly of band 3 oligomers into the plasma membrane during red cell maturation. The oligomeric state of newly synthesized band 3 in early and late erythroblasts was analyzed by size-exclusion high-pressure liquid chromatography of band 3 extracts derived by mild extraction of plasma membranes with the nonionic detergent C12E8 (octaethylene glycol n-dodecyl monoether). This analysis revealed that at the early erythroblast stage, the newly synthesized band 3 is present predominantly as tetramers, whereas at the late stages of erythroid maturation, it is present exclusively as dimers. To examine whether the dimers and tetramers exist in the membrane as preformed stable species or whether they are interconvertible, the fate of band 3 species synthesized during erythroblast maturation was examined by pulse-chase analysis. We showed that the newly synthesized band 3 dimers and tetramers are stable and that there is no interconversion between these species in erythroblast membranes. Pulse-chase analysis followed by cellular fractionation showed that, in early erythroblasts, the newly synthesized band 3 tetramers are initially present in the microsomal fraction and later incorporated stably into the plasma membrane fraction. In contrast, in late erythroblasts the newly synthesized band 3 dimers move rapidly to the plasma membrane fraction but then recycle between the plasma membrane and microsomal fractions. Fluorescence photobleaching recovery studies showed that significant fractions of B3T and B3D are laterally mobile in early and late erythroblast plasma membranes, respectively, suggesting that many B3T-ankyrin complexes are unattached to the membrane skeleton in early erythroblasts and that the membrane skeleton has yet to become tightly organized in late erythroblasts. We postulate that in early erythroblasts, band 3 tetramers are transported through microsomes and stably incorporated into the plasma membrane. However, when ankyrin synthesis is downregulated in late erythroblasts, it appears that B3D are rapidly transported to the plasma membrane but then recycled between the plasma membrane and microsomal compartments. These observations may suggest novel roles for membrane skeletal proteins in stabilizing integral membrane protein oligomers at the plasma membrane and in regulating the endocytosis of such proteins.

Red cell membranes of ankyrin-deficient nb/nb mice lack band 3 tetramers but contain normal membrane skeletons

The role of ankyrin in the formation and stabilization of the spectrin-based skeletal meshwork and of band 3 oligomers was studied by characterizing, in nb/nb mouse red cells, the effect of ankyrin deficiency on skeletal ultrastructure, band 3-skeleton associations, and band 3 oligomeric states. Despite severe ankyrin deficiency, nb/nb mouse red cell skeletal components formed a relatively uniform two-dimensional hexagonal array of junctional complexes cross-linked by spectrin tetramers. Treatment of nb/nb ghosts with the nonionic detergent C12E8 (octaethylene glycol n-dodecyl monoether) resulted in nearly complete extraction of band 3. The extracted band 3 was present exclusively as band 3 dimers. Fluorescence photobleaching recovery and polarized fluorescence depletion measurements showed increases in the laterally (33% vs 10%) and rotationally (90% vs 76%) mobile fractions of band 3 in intact nb/nb compared to control red cells. The rotational correlation time of the major fraction of band 3 molecules was 10-fold shorter in nb/nb compared to control red cells, indicating a significant relaxation of rotational constraints in nb/nb cells. These data suggest that, although ankyrin plays a major role in strengthening the attachment of the skeleton to the membrane bilayer, ankyrin is not required for the formation of a stable two-dimensional spectrin-based skeleton. The absence of band 3 tetramers in the membrane of ankyrin-deficient red cells suggests that ankyrin is required for the formation of stable band 3 tetramers.

A multiparameter analysis of sickle erythrocytes in patients undergoing hydroxyurea therapy

During 24 weeks of hydroxyurea treatment, we monitored red blood cell (RBC) parameters in three patients with sickle cell disease, including F-cell and F-reticulocyte profiles, distributions of delay times for intracellular polymerization, sickle erythrocyte adherence to human umbilical vein endothelial cells in a laminar flow chamber, RBC phthalate density profiles, mean corpuscular hemoglobin concentration and cation content, reticulocyte mean corpuscular hemoglobin concentration, 1H-nuclear magnetic resonance transverse relaxation rates of packed RBCs, and plasma membrane lateral and rotational mobilities of band 3 and glycophorins. Hydroxyurea increases the fraction of cells with sufficiently long delay times to escape the microcirculation before polymerization begins. Furthermore, high pretreatment adherence to human umbilical vein endothelial cells of sickle RBCs decreased to normal after only 2 weeks of hydroxyurea treatment, preceding the increase in fetal hemoglobin levels. The lower adhesion of sickle RBCs to endothelium would facilitate escape from the microcirculation before polymerization begins. Hydroxyurea shifted several biochemical and biophysical parameters of sickle erythrocytes toward values observed with hemoglobin SC disease, suggesting that hydroxyurea moderates sickle cell disease toward the milder, but still clinically significant, hemoglobin SC disease. The 50% reduction in sickle crises documented in the Multicenter Study of Hydroxyurea in Sickle Cell Disease is consistent with this degree of erythrocyte improvement.

Screening of Carnation Cultivars for Resistance to Meloidogyne incognita

A total of 33 carnation cultivars cultured in Korea were screened for resistance to the southern root-knot nematode, Meloidogyne incognita. Carnations were tested by either inoculating with 5,000 eggs or by transplanting into a mixture of bedding medium and soil infested with an average of 435 second-stage juveniles/300 cm(3) soil. Cultivars, Desio, Castelaro, Kappa, Rara, Izu Pink, Target, and Antalia were highly resistant to M. incognita. Twelve cultivars were moderately resistant, and the remaining 14 cultivars were susceptible. These results were similar to those obtained when the cultivars were subjected to field populations of the condition on a carnation farm.

Reorganization of microfilament structure induced by ac electric fields

AC electric fields induce redistribution of integral membrane proteins. Cell-surface receptor redistribution does not consistently follow electric field lines and depends critically on the frequency of the applied ac electric fields, suggesting that mechanisms other than electroosmosis are involved. We hypothesized that cytoskeletal reorganization is responsible for electric field-induced cell-surface receptor redistribution, and used fluorescence video microscopy to study the reorganization of microfilaments in human hepatoma (Hep3B) cells exposed to low-frequency electric fields ranging in strength from 25 mV/cm to 20 V/cm (peak to peak). The frequency of the applied electric field was varied from 1 to 120 Hz and the field exposure duration from 1 to 60 min. In control cells, cytoplasmic microfilaments were aligned in the form of continuous parallel cables along the longitudinal axis of the cell. Exposure of cells to ac electric fields induced alterations in microfilament structure in a manner that depended on the frequency of the applied field. A 1 or 10 Hz ac field caused microfilament reorganization from continuous, aligned cable structures to discontinuous globular patches. In contrast, the structure of microfilaments in cells exposed to 20-120 Hz electric fields did not differ from that in control cells. The extent of microfilament reorganization increased nonlinearly with the electric field strength. The characteristic time for microfilament reorganization in cells exposed to a 1 Hz, 20 V/cm electric field was approximately 5 min. Applied ac electric fields could initiate signal transduction cascades, which in turn cause reorganization of cytoskeletal structures.

Molecular basis of altered red blood cell membrane properties in Southeast Asian ovalocytosis: role of the mutant band 3 protein in band 3 oligomerization and retention by the membrane skeleton

Southeast Asian ovalocytosis (SAO) is an asymptomatic trait characterized by rigid, poorly deformable red cells that resist invasion by several strains of malaria parasites. The underlying molecular genetic defect involves simple heterozygous state for a mutant band 3 protein, which contains a deletion of amino acids 400 through 408, linked with a Lys 56-to-Glu substitution (band 3-Memphis polymorphism). To elucidate the contribution of the mutant SAO band 3 protein to increased SAO red blood cell (RBC) rigidity, we examined the participation of the mutant SAO band 3 protein in increased band 3 attachment to the skeleton and band 3 oligomerization. We found first that SAO RBC skeletons retained more band 3 than normal cells and that this increased retention preferentially involved the mutant SAO band 3 protein. Second, SAO RBCs contained a higher percentage of band 3 oligomer-ankyrin complexes than normal cells, and these oligomers were preferentially enriched by the mutant SAO protein. At the ultrastructural level, the increased oligomer formation of SAO RBCs was reflected by stacking of band 3-containing intramembrane particles (IMP) into longitudinal strands. The IMP stacking was not reversed by treating SAO RBCs in alkaline pH (pH 11), which is known to weaken ankyrin-band 3 interactions, or by removing the cytoplasmic domain of band 3 from SAO membranes with trypsin. Finally, we found that band 3 protein in intact SAO RBCs exhibited a markedly decreased rotational mobility, presumably reflecting the increased oligomerization and the membrane skeletal association of the SAO band 3 protein. We propose that the mutant SAO band 3 has an increased propensity to form oligomers, which appear as longitudinal strands of IMP and exhibit increased association with membrane skeleton. This band 3 oligomerization underlies the increase in membrane rigidity by precluding membrane skeletal extension, which is necessary for membrane deformation.

Induced redistribution of cell surface receptors by alternating current electric fields

The molecular mechanisms that underlie the biological effects of low frequency sinusoidal electric fields may involve induced changes in the physical state of charged cell surface receptors. We have used intensified fluorescence video microscopy to study the redistribution of cell surface receptors, including transferrin receptors (TFR) and low density lipoprotein receptors (LDL-R), in response to externally applied alternating current electric fields in the 3 to 23 V/cm range (peak to peak). Redistribution of both TFR and LDL-R was prominent at frequencies of 1 and 10 Hz but negligible at frequencies of 60 and 120 Hz. Application of a 1 Hz, 23 V/cm field for 15 min caused a twofold change in local TFR surface density, whereas application of a 60 Hz, 23 V/cm field resulted in no significant TFR redistribution. The extent of TFR redistribution induced by a 1 Hz field changed by only 20% over the field strength range from 3.5 to 23 V/cm. AC field-induced cell surface receptor migration did not consistently follow electric field lines, suggesting that mechanisms more complex than classical electrophoresis and electroosmosis mediate receptor redistribution. Joule heating and plasma membrane calcium channel activation were shown not to be involved in the mechanism of receptor redistribution. Applied external electric fields may reorganize cytoskeletal and plasma membrane structures, providing pathways for cell surface receptors to migrate anharmonically.

Deoxygenation affects fluorescence photobleaching recovery measurements of red cell membrane protein lateral mobility

We have used the fluorescence photobleaching recovery technique to study the dependence on oxygen tension of the lateral mobility of fluorescently labeled band 3, the phospholipid analogue fluorescein phosphatidylethanolamine, and glycophorins in normal red blood cell membranes. Band 3 protein and sialic acid moieties on glycophorins were labeled specifically with eosin maleimide and fluorescein thiosemicarbazide, respectively. The band 3 diffusion rate increased from 1.7 x 10(-11) cm2 s-1 to 6.0 x 10(-11) cm2 s-1 as oxygen tension was decreased from 156 to 2 torr, and a further increase to 17 x 10(-11) cm2 s-1 occurred as oxygen tension was decreased from 2 to 0 torr. The fractional mobility of band 3 decreased from 58 to 32% as oxygen tension was decreased from 156 to 0 torr. The phospholipid diffusion coefficient remained constant as oxygen tension was decreased from 156 to 20 torr, but increased from 2.3 x 10(-9) cm2 s-1 to 7.1 x 10(-9) cm2 s-1 as oxygen tension was decreased from 20 to 0 torr. Neither the diffusion coefficient nor the fractional mobility of glycophorins changed significantly at low oxygen tension. Under non-bleaching excitation conditions, intensities of fluorescence emission were identical for oxygenated and deoxygenated eosin-labeled RBCs. Deoxygenated eosin-labeled RBCs required 160-fold greater laser intensities than did oxygenated RBCs to achieve comparable extents of photobleaching, however. Oxygen seems to act as a facilitator of fluorophore photobleaching and may thereby protect the fluorescently labeled red cell membrane from photodamage. Removal of oxygen may allow excited state fluorophores in close proximity to the plasma membrane to react with neighboring proteins or lipids during photobleaching. This effect has important implications for the ability of the fluorescence photobleaching recovery technique to report accurate lateral mobilities of cell membrane molecules under hypoxic conditions.

Duplication of 10 nucleotides in the erythroid band 3 (AE1) gene in a kindred with hereditary spherocytosis and band 3 protein deficiency (band 3PRAGUE)

We describe a duplication of 10 nucleotides (2,455-2,464) in the band 3 gene in a kindred with autosomal dominant hereditary spherocytosis and a partial deficiency of the band 3 protein that is reflected by decreased rate of transmembrane sulfate flux and decreased density of intramembrane particles. The mutant allele potentially encodes an abnormal band 3 protein with a 3.5-kD COOH-terminal truncation; however, we did not detect the mutant protein in the membrane of mature red blood cells. Since the mRNA levels for the mutant and normal alleles are similar and since the band 3 content is the same in the light and dense red cell fractions, we conclude that the mutant band 3 is either not inserted into the plasma membrane or lost from the membrane prior to the release of red blood cells into circulation. We further show that the decrease in band 3 content principally involves the dimeric laterally and rotationally mobile fraction of the band 3 protein, while the laterally immobile and rotationally restricted band 3 fraction is left essentially intact. We propose that the decreased density of intramembrane particles decreases the stability of the membrane lipid bilayer and causes release of lipid microvesicles that leads to surface area deficiency and spherocytosis.