Expression analysis of self-incompatibility-associated genes in non-heading Chinese cabbage.

In Brassicaceae, a self-incompatibility (SI) system mediates pollen-pistil interactions. Self-pollen could be recognized and rejected by incompatible pistils. Several components involved in the SI response have been determined, including S-locus receptor kinase (SRK), S-locus cysteine-rich protein/S-locus protein 11, and arm repeat-containing protein 1 (ARC1). However, the components involved in the SI system of Brassicaceae are not fully understood. Here, we detected expression patterns of 24 SI-related genes in non-heading Chinese cabbage (Brassica campestris ssp chinensis Makino) after compatible and incompatible pollination, and potential interaction relationships of these genes were predicted. SRK and ARC1 transcripts increased initially 0.25 h after incompatible pollination, while kinase-associated protein phosphatase had an expression pattern that was opposite that of SRK transcripts during self-pollination. Plant U-box 8 was not required in the SI response of non-heading Chinese cabbage. Our results showed that the SI signal of non-heading Chinese cabbage could occur within 0.25 h after self-pollination. The hypothetical interaction relationships indicated that plastid-lipid-associated protein and malate dehydrogenase could be negatively regulated by chaperonin 10, glutathione transferase, cytidylate kinase/uridylate kinase, and methionine synthase by indirect interactions. Our findings could be helpful to better understand potential roles of these components in the SI system of non-heading Chinese cabbage.

Dietary protective and risk factors for esophageal and stomach cancers in a low-epidemic area for stomach cancer in Jiangsu Province, China: comparison with those in a high-epidemic area.

Comparative epidemiological studies with ecological and case-control approaches in high- and low-epidemic areas of China have provided us with much evidence with regard to risk and benefit in the environment. To clarify how dietary factors are involved in esophageal and stomach cancer development, we performed a case-control study in a low-epidemic area, and compared the findings with those obtained earlier for a high-epidemic area for stomach cancer in the same Jiangsu Province, China. We recruited 199 and 187 cases with esophageal and stomach cancers, respectively, and 333 population-based common controls. Odds ratios (ORs) for esophageal and stomach cancers were calculated with adjustment for potential confounding factors, using an unconditional logistic model. Current and former smoking elevated the OR for esophageal cancer, along with high intake of pickled vegetables and broiled meat, while decreased ORs were observed for frequently consumed raw vegetables and garlic. With regard to stomach cancer, ORs were increased with frequent consumption of salty fish, leftover gruel, and broiled meat, and lowered by snap bean consumption. The present risk factors were common to the previously obtained results in the high-epidemic area, and similarly distributed in each general population. While more protective factors were observed in the high-epidemic area, their penetrance was much greater in the low-epidemic area. The present study thus suggests that frequent vegetable and garlic consumption contributes to low mortality rates for esophageal and stomach cancers in a low-epidemic area, counteracting similar exposure levels for risk factors as in the high-epidemic area.

Lateral approach without ligament release in total knee arthroplasty: new concepts in the surgical technique.

A lateral approach without ligament release was performed in 475 primary total knee arthroplasties (TKAs) in 344 patients and 50 revision TKAs in 39 patients. Deformities of the genu varum or valgum were corrected by accurate bone cut; no ligament releases were required other than to achieve adequate exposure. A lateral approach allowed both self-centering of the extensor mechanism and knee closure in complete flexion. Better range of motion was achieved. More than 90 degree active flexion usually occurred 3 days postoperatively. Postoperative roentgenograms showed all knees had good varus and valgus stability, which was sustained with time, except 1 with late genu recurvatum due to inadequate polyethylene thickness and the other with a broken tibial base plate. Complications such as disruption of patellar blood supply and knee instability, more frequently observed in the medial approach with ligament release, did not occur. The results suggest that this new technique is safe and may give better outcomes.

Factor of risk for hip fracture in normal Chinese men and women in Taiwan.

We have investigated the age-related change in factor of risk (Phi) for the proximal femoral load during free fall in 548 females and 240 males aged 21-79 years. These individuals were divided into either young (age <50 years) or old group (age >/=50 years). Another 26 females with hip fractures were included for comparison. The bone mineral density (BMD) of proximal femoral neck was measured by a Norland XR-26 dual-energy X-ray absorptiometer (DXA). The estimated fracture load (L) of femoral neck was calculated from the BMD with the regression equation derived by Courtney et al. [2,3] and estimated fall force (F) by body weight and height according to the regression equation derived by Nakamura et al. [6] respectively. Phi was defined as the quotient of F/L. The results showed an age-related decrease of BMD (P < 0.001) in both genders corrected for weight and height. By multiple linear regression analysis, the F decreased significantly with aging corrected for BMD in old males (partial r = -0.255, P < 0.01) and increased with aging in all females (young, partial r=0.287, p < 0.001; old, partial r = 0.252, P < 0.001). L decreased significantly with aging corrected for height and weight in males (young, partial r = -0.401, P < 0.01; old, partial r = -0.178, P < 0.05) and females (young, partial r = -0. 168, P < 0.05; old, partial r = -0.459, P < 0.001). However Phi decreased with aging in young males (P < 0.01) and females (young: P < 0.001, old: P < 0.001). Phi increased in old women but not in old men, and was higher in old women compared with old men. The 26 patients with hip fractures had a significantly higher Phi value than 85 age-matched women. In conclusion, Phi may provide a comprehensive comparison of the risk of hip fracture in the elderly population.

Proximal femoral dimension in elderly Chinese women with hip fractures in Taiwan.

To investigate the relationship between proximal femoral geometry and the occurrence of hip fracture, we compared the geometry of contralateral normal hips of 120 elderly Chinese women with hip fractures, including 63 femoral neck fractures (group A) and 57 intertrochanteric fractures (group B) due to minor trauma, with that of 72 normal elderly Chinese women (group C). The mean ages for group A, B and C subjects were 77.3, 79.7 and 72.9 years, respectively. The femoral neck length (NL), neck width (NW), diameter of femoral head, femoral shaft width just below the lesser trochanter, and neck-shaft angle (theta;) were measured on the anteroposterior plain pelvic radiographs. The mean +/- SD of NL for group A was 50.4 +/- 3.3 mm; for group B, 50.6 +/- 3.1 mm; and for group C, 48.8 +/- 3.6 mm. Statistical analysis by ANOCOVA and regression showed that only NL of women with hip fractures was significantly longer than controls after correction for age, body height and weight (p <0.01). However, the difference in NL between group A and group B was not significant. By linear regression, the probability of fracture increased only with older age (p <0.001), longer NL (p <0.005) and lighter body weight (p <0.05). By logistic regression, each standard deviation increase in NL increased the risk of hip fracture (age-adjusted odds ratio 1.84; 95% CI, 1.11-3.06). The results confirm the relationship between proximal femoral geometry and the occurrence of hip fracture in elderly Chinese women in Taiwan.

Comparative study of lifestyles of residents in high and low risk areas for gastric cancer in Jiangsu Province, China; with special reference to allium vegetables.

There is a low risk area for gastric cancer in Jiangsu Province, China, where people frequently consume raw allium vegetables. As a first step epidemiological study to clarify the factors involved in the low incidence of gastric cancer, we conducted a comparative study of the ecological factors in a high risk area (HRA), Yangzhong, and a low risk area (LRA), Pizhou, using a questionnaire. Subjects were selected from the general population according to age and sex, and comprised 414 residents of the HRA and 425 residents of the LRA. Ecological factors were compared for the two areas by Cochran-Mantel-Haenszel method, age-adjusted. Smoking and drinking habits were found to be more common in the LRA. On the other hand, allium vegetables were consumed in the LRA much more frequently, with high consumption of raw vegetables fruit, tomatoes, kidney beans and soybean products. People who consumed garlic en masse 3 times or more per week were 82% of men and 75% of women in the LRA, and 1% of men and women in the HRA. The results of the survey suggest that frequent consumption of allium vegetables, in addition to other anticancer foods, may be a factor in low mortality for gastric cancer.

Concentration of metal elements in the blood and urine in the patients with cementless total knee arthroplasty.

Titanium (Ti), cobalt (Co) and chromium (Cr) element concentrations in the whole blood and urine specimen in 40 patients with cementless total knee arthroplasty were determined by the electrothermal atomic absorption spectrophotometry. Their ages ranged from 55 to 78 years (mean, 65 years). Twenty of them had loosening of prosthesis and underwent revision surgery, including 4 subjects with Ti-6Al-4V alloy prosthesis and 16 subjects with Co-Cr-Mo alloy prosthesis. The other 20 patients had well-functioning stable prosthesis, including 5 subjects with Ti-6Al-4V alloy prosthesis and 15 subjects with Co-Cr-Mo alloy prosthesis. The mean duration of prostheses implantation in patients with loosened or well-functioning prostheses were 6.5 and 4.0 years, respectively. The control group consisted of 20 age-matched normal subjects who did not undergo any metal implant surgery. Analysis of variance showed that the metal element concentrations in the whole blood, either Co, Cr or Ti, was statistically higher in the patients with loosened prosthesis than the other two groups. However, the metal element concentrations in the urine did not show any difference. The linear regression analysis showed a moderate positive relationship between the metal element concentrations, either Co or Cr elements, in whole blood and urine only in the patients with loosened prostheses. In conclusion, elevated concentration of metal elements may indicate a loosening of prosthesis while the clinical significance of the metal element concentration in the urine needs further investigation.

Intramedullary versus extramedullary tibial alignment guides in total knee arthroplasty.

The intramedullary alignment guide is superior to the extramedullary guide for preparation of the femur in total knee arthroplasty. However, there is controversy over which guide is more appropriate for the tibial sector. We retrospectively compared the accuracy of the intramedullary and extramedullary guides for tibial cutting in patients undergoing total knee arthroplasty. Total knee arthroplasty was performed in 100 knees (68 patients) during a 2-year period. The intramedullary rod was used for preparation of the femur in all cases. For the tibia, each guide system was used in 50 knees. The intramedullary rod was not used in tibias with extreme deformity where the rod could not pass at least two-thirds of the way through the medullary canal. Standing anteroposterior radiographs of the hip to the ankle were taken before surgery and 2 to 6 months postoperatively. The angle formed by the intersection of the tibial mechanical axis and the undersurface of the tibial component (tibial component angle) was measured to check the accuracy of the tibial alignment system. We found no significant differences in the mechanical axis, tibiofemoral alignment, or the tibial component angle between the two groups. The proximal tibial cuts were within 2 degrees of the ideal (90 degrees) in 84% of knees treated with the intramedullary guide, and in 82% of those with the extramedullary guide (p > 0.1). These findings suggest that both guide systems can yield satisfactory alignment. If the tibia is not badly deformed, the intramedullary rod can produce tibial cuts as accurately as the extramedullary system.

Morphological changes induced by prostaglandin E in cultured rat osteoblasts.

Prostaglandin E (PGE)-induced morphological changes of osteoblasts and its possible mechanisms were investigated in cultured calvaria and isolated osteoblasts from long bone fragments of neonatal rats. The control osteoblasts, either on the calvaria or isolated from the long bone fragments, were flat, polygonal in shape, and arranged in a monolayer under scanning electron microscopy (SEM) or phase contrast microscopy. Treatment with 1 mumol/L of prostaglandin E2 (PGE2, 2 h) caused these bone cells to contract a soma, whereas 10 and 100 mumol/L PGE2 (2 h) caused 18%-30% of the bone cells to elongate and expose the undersurface. Incubation of the cultured osteoblasts with PGE2 at different time periods showed a bell-shaped pattern with the optimal response at 2 h of incubation. A similar reaction can be induced by treatment with prostaglandin E1 (PGE1) or dibutyryl cyclic adenosine monophosphate (DBcAMP) in combination with 3-isobutyl-1-methylxanthine (IBMX). Furthermore, we assessed the percentage of responsive isolated bone cells to investigate interactions with other agents. The morphological changes induced by PGEs were inhibited by H-8, a protein kinase inhibitor. On the other hand, elevated intracellular calcium enhanced the PGE-induced morphological changes. Fluorescence labeling showed that PGEs caused the breakdown of the actin microfilaments, but spared the microtubules and vimentin filaments in the isolated osteoblast-like cells. These results suggest that the morphological changes of osteoblasts induced by PGEs may be related to the intracellular cAMP and calcium levels.

Immunohistochemical analysis of matrix proteolytic enzymes in the periprosthetic tissue in the patients with loosening prostheses.

Regional periprosthetic bone resorption plays an important role of prosthesis loosening. In order to study the possible mechanisms of loosening, we investigated the presence of matrix proteolytic enzymes in the periprosthetic tissue by immunohistochemical technique in 72 patients undergoing revision operation of loosened joint prosthesis, including 22 males and 50 females and aged from 19 to 88 years (mean, 61.7 years). Thirty-nine patients had a loosened hip prosthesis (18 males and 21 females) whereas 33 patients had a loosened knee prosthesis (4 males and 29 females). Tissue specimens collected during revision surgery underwent thin slide sections and H & E staining, and were observed under light microscopy and polarized-light microscopy. The results showed many macrophages, histiocytes, fibroblasts, as well as many phagocytosed metal debris and polyethylene debris in the periprosthetic tissues, suggesting an active bone resorption. Furthermore, we used immunohistochemical techniques to detect the distribution of matrix proteolytic enzymes in periprosthetic tissue, including lysosome enzymes (cathepsin B, cathepsin D and cathepsin G), and matrix metalloproteinase (MMPs, MMP-1, MMP-2, MMP-3). The immunostaining were classified as strong positivity, > 70% positive cells; moderate positivity, 20-70% positive cells; weak/negative, < 20% positive cells. The results showed that cathepsin B, cathepsin D and cathepsin G were found in most fibroblasts and macrophage-like cells, including multinuclear giant cells and epithelioid cells. MMPs were found in most fibroblasts and macrophage-like cells, as well as a scant amount in the extracellular matrix. These enzymes were also found in or around blood vessels, the endothelial cells in the richly vascularized tissue. All negative controls showed no staining. The results of immunoreactive staining ranged from 61.1% to 68.1% of strong to moderate positivity. Since these enzymes were related to the degradation of matrix protein, they may be related to the periprosthetic bone resorption. The further clinical significance needs further investigation.

Relation between histological intensity of transforming growth factor-beta isoforms in human osteosarcoma and the rate of lung metastasis.

Even though adjuvant chemotherapy has improved the 5-year survival rate of osteosarcoma patients, a significant percentage of patients eventually die from lung metastasis. Since transforming growth faCtor-beta (TGF-beta) has been demonstrated to be related to the tumor progression, we investigated the clinical implications of the presence of TGF-beta isoforms in 16 human osteosarcoma tissue. There were 10 males and 6 females with a mean age of 20.8 years of age (range, 8 to 57 years). Biopsied specimen before chemotherapy was fixed in 10% formalin, demineralized and followed by paraffin embedding. The locations of tumor included femur (10), tibia (3), humerus (1), fibula (1), and ilium (1). Histologic subtypes included osteoblastic (11), chondroblastic (2), and fibroblastic (3). All patients were followed for a minimum of 1 year (range 12 to 44 months) or to the development of lung metastasis. Five patients (31.3%) developed subsequent lung metastasis during the follow up. We used immunohistochemistry technique to investigate the presence of the TGF-beta isoforms in osteosarcoma tissue and its relationship to the subsequent pulmonary metastasis. The results showed the presence of one or more TGF-beta isoforms in tumor cells in osteosarcoma tissues (13 of 16, 81.3%) in all of the subtypes. However, minimal presence of TGF-beta isoforms was shown in the tumor bone matrix. The expression of TGF-beta1 or TGF-beta3 isoforms was associated with a higher rate of subsequent lung metastasis (p < 0.05, chi-square test). Further research is warranted to determine the utility of routine TGF-beta analysis in the clinical practice.

Simultaneous bilateral total knee arthroplasty in a single procedure.

Eighty-eight consecutive patients undergoing total knee arthroplasty (TKA) were reviewed retrospectively and divided into two groups. Group I (64 patients) had both knees replaced simultaneously by one team in a single procedure while Group II (24 patients) had 2 operations staged about 7 days apart. The blood loss, operative time, knee functional score, period of hospitalisation and complications were documented in order to compare the 2 groups. Performing simultaneous bilateral TKA (Group I) did not increase the incidence of operative or post-operative complications. Equally, the functional score and mean intra- and post-operative blood loss were not influenced. The operative time and duration of hospitalisation were significantly shorter in Group I than in Group II. On the basis of the results of this study, it appears that simultaneous bilateral TKA is beneficial.

Flexor tendon graft for late management of isolated rupture of the profundus tendon.

BACKGROUND: Late management options for the neglected flexor tendon injury include arthrodesis, tenodesis, tendon advancement, or tendon grafting. Although the clinical outcomes of single-stage and second-stage flexor tendon grafting are satisfactory, many controversies exist. The present study retrospectively reviewed the clinical outcomes of flexor tendon grafting for 15 patients with isolated profundus rupture. METHODS: Fifteen cases of isolated rupture of the flexor profundus tendon were treated by free tendon graft. The age of the patients ranged from 13 to 21 years (mean, 17.3 years). The time from injury to operation ranged from 4 to 14 weeks (mean, 8.3 weeks). All tendon grafts were passed through the intact superficialis tendon to repair the injured profundus tendon. These patient were followed up from 14 to 62 months after treatment mean, 31.3 months). RESULTS: All but one patient had less than 3.2 cm of flexion from fingertip to mid-palmar crease. Fourteen patients achieved active distal interphalangeal (DIP) joint flexion of more than 20 degrees. Four patients developed extension loss of the proximal interphalangeal (PIP) joint of more than 30 degrees after surgery. The mean active flexion after surgery was 33 degrees (range, 15-55 degrees) for DIP joints and 91.3 degrees (range, 80-100 degrees) for PIP joints. Three patients had combined extension loss of PIP and DIP joints of more than 40 degrees for the index and middle fingers. Twelve patients (80%) had satisfactory results, whereas treatment of the other 3 patients was considered unsuccessful. CONCLUSION: Flexor tendon graft can be used to reconstruct the isolated rupture of the profundus tendon and achieve satisfactory results for properly selected patients.

Risk of underestimation of the bone mineral density of proximal femur.

Decreased bone mineral density (BMD) in the elderly increases the risk of hip fracture. Measurement of proximal femoral BMD can help us predict the risk of hip fracture, especially in the elderly. Since the BMD of proximal femur is usually measured on the unilateral side, we studied the risk of underestimation with measurement of unilateral proximal femur BMD in 266 normal Chinese women. In order to evaluate the effect of age, these subjects were divided into group A (18-59 years, n = 189) and group B (60-88 years, n = 77). BMDs of both proximal femurs were assessed with Norland 2600 dual photon absorptiometry. Using a cutoff T score of -1, the negative predictive value (NPV) in the entire group was 86.9% for femoral neck BMD and 85.7% for trochanter, and 82.2% for Ward's triangle: in group A, the NPV was 88.9% for femoral neck, 88.8% for trochanter, and 97.2% for Ward's triangle, but in group B, the NPV was 60.0% for femoral neck, 71.0% for trochanter, and 24.1% for Ward's triangle. The accuracy in the entire group was 86.1% for femoral neck, 84.2% for trochanter, and 86.3% for Ward's triangle: in group A the accuracy was 84.6% for femoral neck, 84.9% for trochanter, and 92.8% for Ward's triangle, but in group B, the accuracy was 89.6% for femoral neck, 81.7% for trochanter, and 90.0% for Ward's triangle. In general, NPV and accuracy increased at the expense of positive predictive value when the cutoff T score was changed to -2.5. This study suggested that measurement of unilateral proximal femur BMD was sufficient for screening the contralateral hip BMD in group A at a cutoff T score of -1. However, a T score of -2.5 was recommended for group B, and one should be careful in its application to Ward's triangle.

Triple innominate osteotomy and rotational acetabular osteotomy in the treatment of congenital hip dysplasia.

Congenital hip dysplasia is a developmental disease which predisposes patients to osteoarthritis of the hip. We compare the results and complications of triple innominate osteotomy and rotational acetabular osteotomy in the treatment of this disease. Between 1984 and 1992, 27 patients with 30 dysplastic hips received reconstructive procedures at National Taiwan University Hospital. Fourteen patients (16 hips) with a median age of 18 years were treated by triple innominate osteotomy. Nine of 16 hips had concomitant femoral osteotomy. Another 13 patients (14 hips) with a median age of 24 years were treated by rotational acetabular osteotomy. We compared the radiologic and functional results, complications and satisfaction of the patients in these two groups. Patients who underwent rotational osteotomy showed more correction in roof obliquity than patients who had triple innominate osteotomy. The functional results when evaluated by Harris scores, were better in patients who had triple innominate osteotomy than rotational osteotomy. Complications included one resubluxation of the hip in each group as well as one perforation of the hip joint and one pin break and nonunion at the osteotomy site in the rotational osteotomy group. Patients who had triple innominate osteotomy were more satisfied with the results. With proper selection of patients and accurate performance of the procedure, both triple innominate osteotomy and rotational osteotomy may be used effectively for the treatment of congenital hip dysplasia. However, in our study, patients who underwent rotational osteotomy had better anatomic correction, while those who underwent triple innominate osteotomy had better functional results.

Limb lengthening over an intramedullary nail. An animal study and clinical report.

With the goal of reducing the duration of external fixation in limb lengthening, the authors investigated the feasibility of limb lengthening over an intramedullary nail that could be statically locked when the desired length was achieved, permitting early removal of the external fixation device. In a preliminary study, 8 minigoats underwent 2.0-cm lengthening of the tibia by means of a uniplanar external fixator. Half of the goats had a reamed nail placed in the tibia at the initial surgery. By 10 weeks after lengthening, there no difference in radiographic, histologic, or biomechanical evidence of bone regeneration was found between the tibiae that were nailed and those that were not. In a following clinical series, 15 patients underwent tibial or femoral lengthening by means of a circular frame fixator with a reamed intramedullary nail in place. The postoperative course was uneventful except for 1 infection. The distraction gaps became ossified from 6 months to 1 year, and only 2 patients needed additional bone graftings. The joint function of the lengthened limb at last followup was good. Gradual limb lengthening with a reamed intramedullary nail in place is safe and effective and allows for early removal of the external fixation device.

Use of iliofemoral distraction in reducing high congenital dislocation of the hip before total hip arthroplasty.

The iliofemoral distraction with Wagner's apparatus was conducted in 20 adult patients with untreated unilateral congenital dislocation of the hip (Crowe group IV) before total hip arthroplasty. During the distraction period of 8 to 17 days, this technique had effectively reduced high dislocation of 4.5 cm (range, 3.5-5 cm). No pin-tract infection was encountered. Surgical difficulties in total hip arthroplasty for these patients were reduced. Potential problems, such as irreducibility, overshortening, nerve palsy, and displaced femoral fractures, were avoided. At an average follow-up period of 43 months (range, 25-63 months), all patients have excellent or good results, with an average Harris hip score of 94.3 (range, 84-100). Leg length was restored. The iliofemoral distraction is valuable prior to difficult total hip arthroplasty for high dislocation.

Symmetry of bone mineral density in the hips is not affected by age.

To assess the symmetry of bone mineral density (BMD) of the hips, we used dual photon absorptiometry (DPA) to asses BMD in 266 normal Chinese women in the bilateral femoral neck, trochanter and Ward's triangle regions. Linear regression analysis of the results showed excellent correlation between the hips. The correlation coefficients for the femoral neck, trochanter and Ward's triangle regions were 0.899, 0.892 and 0.935 respectively, and the standard errors of the estimate (S.E.E.) were 0.029, 0.027 and 0.022 g cm-2 respectively. Pooling the BMD data of corresponding regions (n = 532), the correlation coefficient was 0.813 for femoral neck versus trochanter, 0.889 for femoral neck versus Ward's triangle, and 0.833 for trochanter versus Ward's triangle. Further analysis showed mean correlation coefficients of 0.854 for elderly subjects (age > or = 65 years, n = 51) and 0.887 for younger subjects (age < 65 years, n = 215). In conclusion, assessment of left or right hip BMD may be used to represent the BMD of the contralateral hip and can reduce both the cost and radiation exposure during mass screening for osteoporosis.

Bone mineral density in Chinese elderly women with hip fracture.

In order to examine the status of osteoporosis of the patients with hip fracture, we assessed the bone mineral density (BMD) of the contralateral hip of 81 elderly females with hip fracture and compared those with 77 normal Chinese women. The age of fracture subjects was 73.5 +/- 6.6 years (mean +/- SD), and 69.2 +/- 6.9 years for the controls. All of these fractures were caused by minor trauma, such as falls from a standing position or slipping to the ground. The Norland 2600 dual-photon absorptiometer (DPA) was used to evaluate the BMD in the femoral neck, trochanter, and Ward's triangle areas. The BMD for the fracture subjects was significantly lower than those of the controls. By linear regression, the probability of fracture increased exponentially with age and low BMD. The mean BMD for femoral neck of the fracture subjects versus controls was 0.556 versus 0.624 g/cm2; for trochanter: 0.505 versus 0.566 g/cm2; for Ward's triangle: 0.432 versus 0.485 g/cm2. Both negative predictive value (NPV) and positive predictive value (PPV) were acceptable at the prevalence of hip fracture of 5% or 20% and at a cutoff point of 0.65 g/cm2. These data revealed that the degree of relative osteoporosis in the patients with hip fractures was more severe than that of controls.

Ultrastructural studies on myofibrillogenesis and neogenesis of skeletal muscles after prolonged traction in rabbits.

Little is known about the morphological response of muscle after long term traction. The purpose of this study was to investigate the morphological changes of skeletal muscle during limb lengthening. After application of mini-extraskeletal fixator, the hindlimb of New Zealand white rabbit was osteotomized and then slowly lengthened at the rate of 1 mm/day up to a 20 mm gain in length. The muscles of hindlimbs were perfused and dissected. Morphological studies were performed at electron microscopic level. Transmission electron microscopy revealed foci of microtrauma at the myotendinous junction. The distance between the muscle fibers and tendon parenchyma increased, with numerous primitive mesenchyme-like cells interposed within this gap. The cytoplasmic space of these cells was devoid of myofibril formation at the ends of stretched fibers. Within the satellite near the myotendinous junction myofilament production was observed in various gradations of maturation. It is concluded that myofibrillogenesis with traction neogenesis of skeletal muscle during limb lengthening does exist and occurs mainly near the myotendinous junction. The myotendinous junction in mature skeletal muscle actively participated in the process of limb lengthening.