Branched-chain amino acids are linked with iron metabolism

Background

The branched-chain amino acids (BCAAs) valine, leucine and isoleucine are reported to influence erythropoiesis and the human iron status. Large study cohorts encompassing biomarkers of iron metabolism and BCAAs are still lacking.

Methods

We investigated potential interactions between blood concentrations of all three BCAAs valine, leucine and isoleucine and biomarkers of iron metabolism [i.e., hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), iron, transferrin, ferritin, transferrin saturation, soluble transferrin receptor (sTfR)] in 430 outpatients referred for a medical health check-up. Linear regression models were performed to assess possible associations between variables.

Results

All three BCAAs were positively correlated with Hb, ferritin and the sTfR (r-values: 0.145–0.382; P values: <0.001–0.003). The strongest correlation was observed between valine and Hb (r=0.382; P value <0.001). Linear regression models showed a statistically significant influence of all three BCAAs on Hb and ferritin (β-coefficients: 0.173–0.351; all P values: <0.001). Seventeen patients with anemia (4%) were found with significantly lower serum BCAA concentrations compared to 413 non-anemic individuals (P<0.05).

Conclusions

These data indicate a pathophysiological link between the three BCAAs valine, leucine and isoleucine and the human iron indicators Hb and ferritin. Further studies are needed to clarify the exact causal mechanisms of these findings.

[Pediatric resistance training: current issues and concerns]

The impact of a sedentary lifestyle during childhood and adolescence on pathological processes has become a major public health threat. Regular participation in a variety of physical activities during the pediatric years could reduce chronic disease and improve the quality of life of active participants. Although resistance training (RT) was once considered inappropriate for youth, there is a compelling body of evidence which demonstrate the safety and efficacy of RT for children and adolescents. In addition to increasing muscular strength, RT can result in favorable changes in body composition, bone mineral density and motor skill performance provided that the training program is well-designed and supervised by qualified professionals. Preseason conditioning programs which include RT have also been found to reduce sports-related injuries in young athletes. The purpose of this review is to evaluate the risks and benefits associated with youth RT and discuss program design considerations for promoting RT in school- and community-based programs as an on-going lifestyle choice.

Surface grafting of biocompatible phospholipid polymer MPC provides wear resistance of tibial polyethylene insert in artificial knee joints

OBJECTIVE

Aseptic loosening of artificial knee joints induced by wear particles from a tibial polyethylene (PE) insert is a serious problem limiting their longevity. This study investigated the effects of grafting with our original biocompatible phospholipid polymer 2-methacryloyloxyethyl phosphorylcholine (MPC) on the insert surface.

METHODS

The hydrophilicity of the PE surface was determined by the contact angle of a water droplet, and the friction torque was measured against a cobalt-chromium alloy component. The wear amount was compared among PE inserts with or without cross-linking and MPC grafting during 5x10(6) cycles of loading in a knee joint simulator. The surfaces of the insert and the wear particles in the lubricant were subjected to electron and laser microscopic analyses. The mechanical properties of the inserts were evaluated by the small punch test.

RESULTS

The MPC grafting increased hydrophilicity and decreased friction torque. In the simulator experiment, the wear of the tibial insert was significantly suppressed in the cross-linked PE (CLPE) insert, and even more dramatically decreased in the MPC-grafted CLPE insert, as compared to that in the non-cross-linked PE insert. Surface analyses confirmed the wear resistance by the cross-linking, and further by the MPC grafting. The particle size distribution was not affected by cross-linking or MPC grafting. The mechanical properties of the insert material remained unchanged during the loading regardless of the cross-linking or grafting.

CONCLUSION

Surface grafting with MPC polymer furnished the PE insert with wear resistance in an artificial knee joint through increased hydrophilicity and decreased friction torque.

Selection of highly osteogenic and chondrogenic cells from bone marrow stromal cells in biocompatible polymer-coated plates

To enrich the subpopulation that preserves self-renewal and multipotentiality from conventionally prepared bone marrow stromal cells (MSCs), we attempted to use 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer-coated plates that selected the MSCs with strong adhesion ability and evaluated the proliferation ability or osteogenic/chondrogenic potential of the MPC polymer-selected MSCs. The number of MSCs that were attached to the MPC polymer-coated plates decreased with an increase in the density of MPC unit (0-10%), whereas no significant difference in the proliferation ability was seen among these cells. The surface epitopes of CD29, CD44, CD105, and CD166, and not CD34 or CD45, were detectable in the cells of all MPC polymer-coated plates, implying that they belong to the MSC category. In the osteogenic and chondrogenic induction, the MSCs selected by the 2-5% MPC unit composition showed higher expression levels of osteoblastic and chondrocytic markers (COL1A1/ALP, or COL2A1/COL10A1/Sox9) at passage 2, compared with those of 0-1% or even 10% MPC unit composition, while the enhanced effects continued by passage 5. The selection based on the adequate cell adhesiveness by the MPC polymer-coated plates could improve the osteogenic and chondrogenic potential of MSCs, which would provide cell sources that can be used to treat the more severe and various bone/cartilage diseases.

Long-term results of rotational acetabular osteotomy in patients with slight narrowing of the joint space on preoperative radiographic findings

Between 1975 and 1984, we performed rotational acetabular osteotomy in 22 female patients with painful hip dysplasia. At the time of surgery, the patients were in their twenties, and radiographs showed slight narrowing of the joint space. Of these patients, 15 were followed-up for 15 to 22 years (average, 19.8 years) after surgery. The preoperative severity of coxarthrosis in all 15 hips was graded as stage II, according to the classification of coxarthrosis advocated by the Japanese Orthopaedic Association. All 15 patients available for follow-up had had no additional operations on the operated side during the follow-up period. At the time of follow-up, the patients were aged 41 to 48 years (average, 44.3 years). Of the 15 patients, 12 had little or no pain and 14 could walk for more than 30 min without a cane; the severity of coxarthrosis was graded stage I in 3 hips, stage II in 4 hips, stage III in 5 hips, and stage IV in 3 hips. We conclude that rotational acetabular osteotomy is efficacious for patients who have preoperative radiographic findings of slight narrowing of the joint space.

Combined intertrochanteric valgus and rotational acetabular osteotomy

Results are reported for combined intertrochanteric valgus and rotational acetabular osteotomies in 18 dysplastic hips (17 patients), involving two types of femoral head and neck deformities, after an average followup of 13 years (range, 8.9-22.6 years). The mean age of the patients at the time of surgery was 25 years (range, 11-36 years). Pain was the indication for surgery in all patients. The preoperative deformities were classified into two groups. Hips in Group I had an angular head and a normal or valgus neck. Hips in Group II had an ovoid head, a short neck in varus angulation, and relative overgrowth of the greater trochanter. There were seven hips (seven patients) in Group I, and 11 hips (10 patients) in Group II. The sum of the most recent pain score and gait score of Merle d'Aubigné (a full score of 12 points) was 11 to 12 points for seven of 11 hips of Group II, and 11 to 12 points for only one of the seven hips of Group I. For patients with hip pain in Group II, this operation fairly consistently relieves pain for at least an average of 13 years, but whether the rate of development of osteoarthrosis is retarded is not known.

Long-term results of rotational acetabular osteotomy in young patients with advanced osteoarthrosis of the hip

Between 1974 and 1987, we performed 38 rotational acetabular osteotomies to treat advanced coxarthrosis caused by acetabular dysplasia in 38 patients who were aged 40 years old or less at the time of surgery. Of these patients, 28 were followed-up for more than 10 years after surgery. The preoperative severity of coxarthrosis was graded as stage III in 21 hips and as stage IV in 7 hips, according to our modification of the classification of coxarthrosis advocated by the Japanese Orthopaedic Association. At the time of follow-up, 27 patients retained their own hip joints on the operated side 10 to 18 years (average, 13 years) after surgery, and the remaining patient had had a secondary total hip replacement 7 years after the surgery. Of the 27 patients who retained their own hip joints on the operated side, 20 had little or no pain and none suffered from severe pain in the operated hip; the severity of coxarthrosis was graded as stage II in 4 hips, as stage III in 9 hips, and as stage IV in 14 hips. We conclude that rotational acetabular osteotomy can be a useful procedure in young patients who have advanced coxarthrosis secondary to acetabular dysplasia.

Rotational acetabular osteotomy using biodegradable internal fixation

We used biodegradable poly-L-lactide screws in rotational acetabular osteotomy in 41 hips of 41 patients, and studied the complications after an average follow-up of 4.9 years (range 1.0-7.7 years). There were 39 females and 2 males, their average age at the time of the operation was 32 years (range 12-55 years). A small subcutaneous abscess appeared around the non-absorbable sutures in 2 patients after surgery. There was 1 case of thrombophlebitis and 1 of local dermatitis. The small subcutaneous abscess resolved after the removal of the suture material in the 2 cases, and the thrombophlebitis resolved with aspirin. The local dermatitis persisted but was cured by local steroid therapy over 5.8 years. The incidence of local dermatitis after the use of biodegradable implants should be further investigated.

Relationship between cranial base and maxillofacial morphology

The aims of this study were to investigate the relationships between the cranial base and maxillofacial morphology in Japanese crania, and to examine the differences between Class I and Class II samples. Data were obtained from 46 male Japanese crania from the collection of the Jikei University School of Medicine (Tokyo). The sample represents populations which would have lived during the last 100 years. A principal component analysis of linear and angular measurements showed that the anterior and posterior cranial base, and the cranial base angle were associated in different ways with different aspects of maxillofacial morphology. Variation in the anterior cranial base was associated with differences in facial height, lower facial height, bicondylar breadth, ramal height, and ramal width, while posterior cranial base length was correlated with bizygomatic breadth. The cranial base angle was negatively correlated with SNA (r = -0.46) and SNB (r = -0.59), and positively correlated with the palatal and occlusal plane angles. There were significant differences between Class I and Class II specimens in palatal width, SNA, ANB, and the palatal plane angle, but no significant difference in cranial base length or angle. The evidence suggested that cranial base shape and size was related to facial length, inclination of the maxilla, and both maxillary and mandibular prognathism.

Tweed triangle and soft-tissue consideration of Japanese with normal occlusion and good facial profile

A total of thirty-six Japanese adult subjects (consisting of eighteen men and eighteen women) with normal occlusion and harmonious facial features were subjected to cephalographic examination for the purpose of studying their soft tissues. Out of this group, twenty were selected and compared with twenty Class II, Division 1 and twenty Class III patients for the purpose of establishing an appropriate diagnostic guide for the Tweed triangle. These are our conclusions: 1. The Z angle of the Japanese subjects with normal occlusion was 69.70 degrees for the men and 71.75 degrees for the women. There is no significant difference between the sexes. 2. Although there are no significant differences between the sexes for the integumental and total chins, there is slight sexual difference for the upper lip measurement. 3. As compared to the subjects with normal occlusion, there is a significant difference for the Z angle of Class II, Division 1 and Class III patients. 4. In this study, the measurements of the Tweed triangle were FMA 27.28 degrees, IMPA 95.50 degrees, and FMIA 57.22 degrees. On the basis of this study and the reports of other Japanese investigators, we would like to suggest an FMIA of 57 degrees as being the most suitable basis for the diagnosis of Japanese patients, but this should be modified according to the FMA value.