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.

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.

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.

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.

Analysis of neogenesis in rabbit skeletal muscles after chronic traction.

After application of a modified Orthofix mini-extraskeletal fixator, the hind limb of New Zealand White rabbits was osteotomized and then slowly lengthened at a rate of 1 mm/day. After a 20 mm gain in length, the net weight and the length of muscular and tendinous portions were measured and histological examination was carried out in triceps surae muscles. Quantitative analysis showed a significant increase in the gained length of the muscular portion (28.05% to 30.65%). Histological studies of these lengthened muscles showed a generalized increase in cellularity with scanty inflammatory cell infiltration near the myotendinous junction. The increased cellularity is due to the presence of muscle precursor cells characterized by large, oval and pale-stained vesicular nuclei and two prominent nucleoli. The nuclei of these precursor cells were larger and more numerous near the myotendinous junction, and gradually changed into a flattened and more condensed form at a distance from the junction. Occasionally, chains of centrally-located nuclei of primitive myoblasts were also visible. It is concluded that traction neogenesis of the skeletal muscle during limb lengthening does exist and occurs mainly near the myotendinous junction.

Corticosteroid Reduces Blood Flow to Femoral Heads in Rabbits.

Avascular necrosis of the femoral head is one of the common problems in orthopedic practice in Taiwan. The subchondral bone loses its blood supply which weakens its biomechanical support. Steroid overuse is one of many possible etiologies in reducing blood flow to the femoral head. Laser Doppler velocimeter is a precise monitor of regional blood flow of bone which is expressed in perfusion units (PU). In the control group the rabbits were injected with normal saline and there were no statistical differences between blood flow to the right hip (39.26 +/- 5.64 PU) and left hip (38.58 +/- 4.35 PU). In group B a weekly injection of methylprednisolone into rabbits for 6 weeks demonstrated the reduction of blood flow of femoral head (24.74 +/- 3.13 PU) by the laser Doppler velocimeter. The flow decreased further (15.93 +/- 2.33 PU) by 12 weeks of steroid treatment. In group C after a weekly injection of steroid for 6 weeks the flow became 31.63 +/- 4.79 PU. The steroid was then discontinued for 3 weeks and the flow was 34.6 +/- 1.34 PU. In group D the blood flow was 25.89 +/- 4.01 PU after 6 weeks of steroid treatment and we stopped the steroid for 6 weeks, the blood flow became 29.86 +/- 2.59 PU. The merit of our experiment established a model of study in avascular necrosis of the femoral head in rabbits. Copyright 1994 S. Karger AG, Basel

Absorption of lidocaine following topical application in microvascular procedures on rabbits.

Fifty rabbits were used to investigate the absorption of lidocaine following its topical application to blood vessels. The lidocaine level in the blood was determined by gas chromatography and the enzyme immunoassay. Animals were divided into five groups according to anatomic site (femoral vs iliac) and according to whether vessels were intact or anastomosed. In the last group (E), a water-tight sleeve was placed on the anastomosed femoral artery so that the lidocaine contacted only a small segment of the artery. In each group, 0.4 and 1 ml of 10% lidocaine were used. Our results revealed that absorption of lidocaine from topical usage was rapid. The absorption peak occurred within 5-15 min. The serum concentration of lidocaine was significantly higher in groups with intact vessels than in those with anastomosed ones. The peak level of lidocaine in the serum occurred sooner in the iliac area than in the femoral area. Absorption in group E was very low due to only a small segment of the artery being immersed with lidocaine. The main absorption site of lidocaine was not through the vessel but through the perivascular area. Toxicity may develop clinically if a high concentration of lidocaine is applied on a vessel during microsurgery.

Inhibition of estradiol-induced early osteoarthritic changes by tamoxifen.

Previous studies on osteoarthritic changes induced by intraarticular injections of estradiol benzoate (EB) suggest estrogen as a risk factor in the development of knee osteoarthritis (OA). The present study observed the anti-arthritic effects of tamoxifen (TMX). Oophorectomized rabbits were subjected to intraarticular injections of vehicle control, EB, TMX, or EB/TMX for 3 weeks. The cartilage changes were assessed by light and scanning electron microscopic examination, enzyme histochemical analysis, and the amount of alcian blue stain binding to glycosaminoglycans. EB injections resulted in cell necrosis, chondrocyte clonings, and pittings, whereas the vehicle control, TMX, and EB/TMX-injected groups showed no histologic abnormalities. Histochemical analysis showed that the numbers of lactate dehydrogenase (LDH)-reactive chondrocytes in the EB-injected group were significantly reduced when compared to other groups (p less than 0.001). The injections of EB/TMX significantly reduced the chondrocyte numbers in the lateral superficial layer (p less than 0.05), compared with the vehicle injection. TMX-injected group revealed slight although insignificant decreases in chondrocyte numbers. The amount of alcian blue stains, representing the relative amount of proteoglycans, significantly decreased only in the superficial layer of the EB- and EB/TMX-injected groups (p less than 0.05). TMX, when concurrently injected with EB, antagonized the chondrodestructive effects of estradiol at the early stage of knee OA in rabbits. The results suggest the potential therapeutic use of TMX at the early stage of OA.

Up-regulation of estrogen receptors in rabbit osteoarthritic cartilage.

The purpose of this study was to investigate the alteration of estrogen receptors in an early stage of estradiol-induced osteoarthritic knees. After 3 weeks of intraarticular injections of estradiol benzoate to both knees in ovariectomized rabbits, the articular cartilages of femoral condyle and tibial plateau were harvested and pooled separately in each rabbit. The cytosolic estradiol receptor was determined by hydroxylapatite-column assay. The receptor levels (fmol/mg protein) were determined by the analysis of specific 3H-labelled estradiol binding data. In the present study, the specific binding to 3H-estradiol in the femoral condyle cartilage of estradiol-treated rabbits was 1.7 fold of that in vehicle-treated rabbits. The difference between them was highly significant (p less than 0.01). On the other hand, estrogen receptors were nondetectable in the tibial plateau of either vehicle- or estradiol-treated rabbits. It appeared that the cytosolic estradiol receptor existed preferentially in the cartilage of the femoral condyle, rather than in that of the tibial plateau. Since a direct link of estrogen to the development of osteoarthritis in rabbit knees was demonstrated as early as 3 weeks, it is suggested that up-regulation of estrogen receptors in cartilage might initiate the osteoarthritic changes.

Osteoarthritis in women: its relationship to estrogen and current trends.

With our expanding knowledge of osteoarthritis (OA) over the years, our concept of this "aging" disease has been re-evaluated to that which is the opposite of traditional views. To clinicians and scientists, OA is no longer the inevitable disease of aging, as one conceptualizes gray hair. Epidemiological studies show a higher incidence of OA affecting polyarticular joints in women than age-matched men, particularly those over the age of 55. This discrepancy in sex difference in the OA incidence highlights the significance of sex hormones and their alterations in menopause. Evidence indicates that this alteration possibly occurs early in adult life and may well persist into menopause. As well, this hormonal perturbation is thought to be consequent to obesity in these women. Both in vivo and in vitro studies suggest that estrogen is chondrodestructive via the receptor-mediated mechanism. The finding of estrogen receptor in canine, rabbit, and human articular cartilage further confirms this hypothesis. Recent findings of elevated synovial estradiol level and higher estrogen receptor bindings in human osteoarthritic cartilage strongly suggest the importance of local uptake of estradiol (E2) and the possible up-regulation of estrogen receptors. Estrogen, like other hypothesized etiologies, is important in the development of OA in women.

Transplantation of preserved composite tendon allografts.

Composite flexor-tendon grafts (both tendons with sheath and pulleys intact) were performed in adult chickens comparing fresh autografts with allografts stored in 1:5,000 merthiolate under refrigeration for two months. The gross and microscopic findings were assessed one week to one year after transfer. The allografts were somewhat slower to heal but otherwise differed little from the autografts, and were readily accepted eventually with only minor adhesions between the grafted tendon and the sheath.

Contact areas and pressure distributions in the subtalar joint.

We investigated how foot position and ankle arthrodesis affect the contact characteristics of the subtalar joint. Nine fresh-frozen specimens of amputated lower legs were used. Pressure-sensitive films were inserted into the anterior and posterior articulation of the subtalar joint. The contact areas and pressure for various foot positions and under axial loads of 600, 1200, and 1800 N were determined based on the gray level of the digitized film. In neutral position and under a 600 N load, the maximum contact pressure in the subtalar joint was 5.13 +/- 1.16 MPa. The contact area (1.18 +/- 0.35 cm2) was only 12.7% of the whole subtalar articulation area (9.31 +/- 0.66 cm2), and the total force (348.5 +/- 41.7 N) transmitted via this contact area was about 58% of the applied load (600 N). Dorsiflexion of the foot increased the contact area and the force transmitted, but decreased the average contact pressure in the subtalar joint, while the reverse occurred in plantar flexion. Eversion increased the subtalar contact stress, whereas inversion up to 10 degrees decreased it. Ankle joint arthrodesis shifted the contact areas in the subtalar joint posteriorly in all inversion/eversion positions. Moreover, total force transmitted through the subtalar joint as well as the contact pressure increased.

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.

Emergency separation of omphaloischiopagus tetrapus conjoined twins in the newborn period.

This article reports an experience on subemergent separation of xyphoomphaloischiopagus tetrapus conjoined twins in the newborn period when survival of one of the twins was threatened by a severely malformed counterpart.

Glycocalyx production and adherence of Staphylococcus to biomaterials.

Glycocalyx is suggested to play an important role in the pathogenesis of biomaterial-centered infection. Using an accurate and sensitive method to quantify glycocalyx and bacterial adherence, we have demonstrated that the producer of the most glycocalyx also exhibited the highest adherence index, whereas low producers exhibited the least (p less than 0.01). Additionally, at various concentrations the high producer had the greater tendency to adhere and grow on stainless steel wires and tubes (p less than 0.001). The adherence index, referred as the ratio of tritiated thymidine uptake on wires to colony forming units (CFU), was also the highest in high producers. The adherence index increased as the glycocalyx index increased. It was suggested that glycocalyx production enhanced the adherence of Staphylococcus epidermidis to biomaterials and caused persistent and intractable infections. In short, the glycocalyx index and the adherence index can be reliable indices of biomaterial-centered infection.

Cushioning effect of heel cups.

Three types of heel cups, two rubber and one plastic, were evaluated in this study. The vertical forces under the heel were monitored using the Computer Dyno Graphy system in 16 normal subjects. Peak force reduction in walking and running after heel cup use was found for all three types of heel cups. The shock absorbency (peak force reduction as a ratio) of heel cups was better in walking (3.5 km h(-1)) than in running (10 km h(-1)). Pressure-sensitive film under the heel revealed that the pressure concentration at the location of calcaneal tuberosity could be smoothed out by the use of heel cups. When plastic heel cups were used, pedobarography showed that the contact area of the heel while standing decreased to 61% of that when barefoot. Roentgenographic study in six patients with heel pain syndrome showed that the thickness of the heel pad increased from 14.4 mm (SD 1.4 mm) to 17.0 mm (SD 1.2 mm) when plastic heel cups were used.

Failure sites and peak tensile forces of the composite triceps surae muscle by passive extension in the rabbit.

The triceps surae muscle-tendon unit of rabbit was tested by a passive extension technique. The effects of different stretch rates were evaluated. Functioning as a composite muscle-tendon unit, the triceps surae responded viscoelastically to the tensile loads. The sites of failure were consistent at the muscular portion near the musculotendinous junction. Failure occurred within 0.1-1.0 mm of the distal musculotendinous junction for the soleus muscle and within 5-10 mm proximal to the distal musculotendinous junction in the lateral head of gastrocnemius muscle. In the medial head of gastrocnemius muscle failure occurred within 15-30 mm proximal to the distal musculotendinous junction. There was a greater peak tensile force requirement and a greater energy absorption when tested with faster stretch rates. These results furnish evidence that the biomechanical property of composite musculotendinous unit is strain-rate dependent and behaves viscoelastically.

Bilateral severance of thumbs: report of two cases.

Management of hand injuries is a common practice but bilateral amputation of thumbs is very rare. We report on two cases of both thumbs amputated by a similar machine. In case 1, the man's left thumb was closed with a composite skin graft because the severance was through the middle of the nail. A wrap-around procedure was performed to reconstruct the right thumb which was infected after a primary V-Y advancement flap. The final results were acceptable. Replantation of detached thumbs, if possible, achieves the best functional recovery, which was well demonstrated in Case 2. Although the interphalangeal joints were arthrodesed, the patient was greatly satisfied with the results because of excellent appearance, adequate strength and nearly normal sensation. Prevention of bilateral thumb injuries is important. The paper-cutting machine on which these accidents occurred should be improved in order to prevent further similar catastrophes.

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.

The role of continuous passive motion following total knee arthroplasty.

A retrospective review of 25 knees with postoperative continuous passive motion (CPM) treatment following total knee arthroplasty (TKA) was compared with a control group of 25 knees without postoperative CPM. The diagnoses were similar in both groups, with osteoarthritis in 43 knees, traumatic arthritis in 2 knees, rheumatoid arthritis in 2 knees, osteonecrosis in one knee, and gouty arthritis in one knee. Average knee flexion at discharge was 93.2 degrees in the CPM group and 86.5 degrees in the control group (p less than 0.01). Eighty percent of the CPM group and 64% of the control group had achieved 90 degrees of flexion before hospital discharge. The time required to achieve 90 degrees of flexion after TKA averaged 9.6 days in the CPM group and 11 days in the control group (p less than 0.01). There was no significant difference in flexion at 3 months or at 1 year postoperatively between the two groups. The duration of hospitalization was not significantly different between the two groups. One knee in the CPM group and 3 knees in the control group required manipulation. Wound hemovac drainage and transfusion requirements were not significantly different. The number of pain medication was not significantly different between the two groups. The CPM made the TKA knee achieve motion earlier with fewer complications.