Polarized osteoclasts put marks of tartrate-resistant acid phosphatase on dentin slices--a simple method for identifying polarized osteoclasts

Osteoclasts form ruffled borders and sealing zones toward bone surfaces to resorb bone. Sealing zones are defined as ringed structures of F-actin dots (actin rings). Polarized osteoclasts secrete protons to bone surfaces via vacuolar proton ATPase through ruffled borders. Catabolic enzymes such as tartrate-resistant acid phosphatase (TRAP) and cathepsin K are also secreted to bone surfaces. Here we show a simple method of identifying functional vestiges of polarized osteoclasts. Osteoclasts obtained from cocultures of mouse osteoblasts and bone marrow cells were cultured for 48 h on dentin slices. Cultures were then fixed and stained for TRAP to identify osteoclasts on the slices. Cells were removed from the slices with cotton swabs, and the slices subjected to TRAP and Mayer's hematoxylin staining. Small TRAP-positive spots (TRAP-marks) were detected in the resorption pits stained with Mayer's hematoxylin. Pitted areas were not always located in the places of osteoclasts, but osteoclasts existed on all TRAP-marks. A time course experiment showed that the number of TRAP-marks was maintained, while the number of resorption pits increased with the culture period. The position of actin rings formed in osteoclasts corresponded to that of TRAP-marks on dentin slices. Immunostaining of dentin slices showed that both cathepsin K and vacuolar proton ATPase were colocalized with the TRAP-marks. Treatment of osteoclast cultures with alendronate, a bisphosphonate, suppressed the formation of TRAP-marks and resorption pits without affecting the cell viability. Calcitonin induced the disappearance of both actin rings and TRAP-marks in osteoclast cultures. These results suggest that TRAP-marks are vestiges of proteins secreted by polarized osteoclasts.     

Increased levels of serum matrix metalloproteinase-3 in haemodialysis patients with dialysis-related amyloidosis

Background: It is recognized that matrix metalloproteinase‐3 (MMP‐3) is abundantly expressed in active rheumatoid synovium, and that serum level of MMP‐3 is a useful marker for diagnosis of rheumatoid arthritis and for evaluation of prognosis in joint destruction. Little is known about serum MMP‐3 levels in haemodialysis (HD) patients, and thus, the association between serum MMP‐3 and dialysis‐related amyloidosis (DRA) has yet to be elucidated. Methods: Serum levels of MMP‐3 were measured by enzyme immunoassay in 150 HD patients, 90 without DRA and 60 with DRA, before HD. Simple regression analysis was performed to investigate the relationship between serum level of MMP‐3 and clinical parameters, including age, HD duration, C‐reactive protein and β2 microglobulin (BMG). Results: Serum levels of MMP‐3 were significantly higher in HD patients with DRA than in HD patients without DRA (258.2 ± 118.1 vs 201.5 ± 98.4 pg/mL, P = 0.0017), and both levels were significantly higher than those of healthy subjects (45.6 ± 13.4 pg/mL, P < 0.0001). Serum MMP‐3 levels significantly correlated with serum levels of BMG (r = 0.197, P = 0.0164) and HD duration (r = 0.168, P = 0.0427). Moreover, serum MMP‐3 levels significantly correlated with serum BMG levels in HD patients without DRA (r = 0.341, P = 0.0012), but not in HD patients with DRA. Conclusion: Our results suggest that matrix metalloproteinase activity increases in HD patients, which may be associated with BMG and DRA.     

Bispectral index monitoring in fast track pediatric cardiac surgery

BACKGROUND: We evaluated the changes in the bispectral index (BIS) as a potential indicator of level of consciousness in infants and children undergoing fast track cardiac surgery. METHODS: Twenty-one children undergoing fast track cardiac surgery were recruited into this study. Anesthesia was maintained with inhaled sevoflurane and intravenous fentanyl 10 microg x kg(-1). Cardiopulmonary bypass (CPB) with mild hypothermia and an immediate tracheal extubation protocol were used. BIS was recorded throughout the operation. RESULTS: In average, BIS was kept almost under 70 with 0.5-3.0% of sevoflurane. During rewarming from mild hypothermia, BIS increased temporarily over 70 in about a half of children. We, therefore, treated them by increasing sevoflurane concentration. Nineteen children were extubated in the operating room, and two patients were extubated in ICU within three hours after surgery. CONCLUSIONS: BIS was kept within the level of adequate sedation during surgery. However, since the increase in BIS during the rewarming phase could reflect light anesthesia, caution should be taken around this phase.     

Contractile reserve of valvular heart diseases echocardiographically evaluated by epinephrine loading before and after cardiac surgery

In order to evaluate cardiac contractile reserve, echocardiographic studies were performed on 59 patients with acquired valvular heart disease and 13 patients with atrial septal defect. After epinephrine loading, the 59 patients were classified into three groups. In group I, echocardiographically-obtained left ventricular posterior wall excursion (PWE) remained below 10 mm after the administration of 2 microgram/min epinephrine. This group included patients with PWE below 10 mm after 1 microgram/min epinephrine loading but who could not endure the 2 microgram/min infusion because of significant adverse effects. In group II, PWE was less than 10 mm before the loading, but exceeded 10 mm after the administration of 1 or 2 microgram/min epinephrine loading. In group III, PWE exceeded 10 mm without stress. The conclusions derived from our data are as follows: The PWE and mean left ventricular posterior wall velocity (mPWV) obtained by echocardiography reflect the stroke volume derived from the thermodilution technique. It is possible to estimate the cardiac contractile force in patients who have a paradoxical motion of the interventricular septum, in the preoperative and even in the early postoperative periods. Patients whose PWE and mPWV are less than 10 mm and 35 mm/sec, respectively, after 2 microgram/min loading of epinephrine (group I), are likely to have severe cardiac failure after surgery. Inotropic stimulation is considered to be a very useful indicator for prediction of cardiac contractile reserve. Patients having decreased PWE, mPWV, mVcf and EF before surgery may have arrested recovery in both short- or long-term follow-up. However, surgical treatment is recommended for these patients with low cardiac function, because some improvement can be expected after surgery.     

Linkage guide for rotational alignment during total knee arthroplasty

A linkage guide was devised for use in conjunction with knee arthroplasty instruments to achieve proper component rotation. The femoral component was rotationally aligned to the surgical epicondylar axis using one guide. The other guides were used after all bone surfaces were cut and soft tissue balancing was completed. A Kirschner wire was guided into the proximal tibial aspect parallel to the sagittal plane of the femoral component with the patella in its normal position and the knee in full extension. The wire was used as a reference to determine tibial component rotation. The relative rotational alignment of 21 knees in 19 patients who had undergone cruciate-retaining total knee arthroplasty utilizing this guide was assessed using the modified Eckhoff method. The results of radiographic analysis were compared with those in a control group of 25 knees where the guide was not employed. The external rotation of the femoral component relative to the tibial component was 1.3° ± 2.0° (mean ± SD) in the guided group and 1.1° ± 4.4° in the control group. The relative rotational angle was significantly more consistent using the guide. Implant malrotation can be reduced using our technique.     

Silent cerebral infarction in hemodialysis patients

BACKGROUND: Cerebrovascular diseases are very common in hemodialysis (HD) patients. Silent cerebral infarction (SCI) has not been investigated in HD patients although it may be a significant risk factor for cerebrovascular diseases. HYPOTHESIS: Chronic renal failure may be an independent risk factor for SCI and cerebrovascular diseases. METHODS: Cranial magnetic resonance imaging (MRI) was performed on 123 HD patients without symptomatic cerebrovascular disease and on 52 control subjects. We investigated the prevalence of SCI and performed cross-sectional study using multiple logistic analysis to assess the relationship between SCI and the risk factors. RESULTS: The prevalence of SCI was significantly higher in HD patients than in the healthy control group (60 patients (48.8%) vs. 5 patients (9.6%), chi(2) = 22.4, p < 0.0001). Multiple logistic regression analysis with all subjects showed that independent risk factors of SCI were chronic renal failure, hypertension, smoking and age (R(2) = 0.468, p < 0.0001). In only the HD patient group, age and smoking were shown to be independent risk factors of SCI (R(2) = 0.378, p < 0.0001) while HD duration and hypertension were not. CONCLUSIONS: The findings of the present study indicate that chronic renal failure maintained by hemodialysis increases the prevalence of SCI and that age and smoking habits are also significantly associated with SCI in HD patients.     

One and a half ventricle repair for Ebstein’s anomaly

The surgical strategy for patients having Ebstein’s anomaly and hypoplastic right ventricle is controversial. An 11-year-old boy patient having such condition, with estimated end-diastolic volume index of the atrialized and functional right ventricle being 70% of normally expected values, underwent biventricular repair. Immediately after the surgery, however, he developed right heart failure with the central venous pressure of 11 mmHg. He consequently underwent additional bidirectional cavopulmonary anastomosis, thereby converting the biventricular repair into one and a half ventricle repair. He recovered uneventfully and is doing well 2 years after the surgery.     

Findings of pelvic musculature and efficacy of laparoscopic muscle stimulator in laparoscopy-assisted anorectal pull-through for high imperforate anus

Background: Laparoscopic findings of levator muscle and the efficacy of laparoscopic muscle stimulator (LMS) in infants with high imperforate anus have not been reported. Methods: Twelve patients underwent laparoscopically assisted anorectoplasty for high imperforate anus. Following laparoscopic dissection of the distal rectum and division of the fistula, levator muscles in the pelvic floor were stimulated with a 5-mm-diameter LMS. Dilatation was done by inserting a guidewire and balloon catheter through the center of the levator muscle sling and muscle complex. Rectal pull-through and anastomosis between the rectum and anus were successfully completed. Results: LMS showed good contraction of levator muscles and enhanced accurate midline placement of pull-through rectum. LMS was particularly useful in observing weak muscles in infants with rectovesical fistula. Conclusions: Laparoscopy and LMS offer excellent visualization of the pelvic musculature and precise tract of rectal pull-through. Fecal continence will be assessed by long-term follow-up.     

"Spiral-cuff" technique for repair of anomalous left coronary artery from the pulmonary artery

We describe a new technique for coronary transfer in the repair of anomalous origin of the left coronary artery from the pulmonary artery. The left coronary artery is elongated with the native pulmonary artery wall to form a spiral-shaped coronary cuff to construct an unstretched new left coronary artery system from the ascending aorta. A postoperative angiographic scan showed good flow of the left coronary artery without any kinking or narrowing. This technique is considered useful when an anomalous coronary artery arises a long way from the ascending aorta.