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Biomedical subjects

K Kaneda

Publications and source records attributed to K Kaneda.

446 records · Page 25Linked to original sources
PubMedDate not supplied

Graft site morbidity with autogenous semitendinosus and gracilis tendons.

To distinguish between morbidity caused by harvesting semitendinosus and gracilis tendons and morbidity associated with anterior cruciate ligament reconstruction surgery, we performed a prospective randomized study using 65 patients who underwent anterior cruciate ligament reconstruction using these tendons. The patients underwent either contralateral (N = 34) or ipsilateral (N = 31) graft harvest. For the nonoperated knees in the ipsilateral harvest group, isometric and isokinetic strength of the quadriceps and hamstring muscles increased to approximately 120% of the preoperative value at 12 months after surgery. Compared with these knees, the tendon harvest did not affect quadriceps muscle strength at all. However, harvest did decrease hamstring muscles strength for 9 months after surgery. The graft harvest in the knees with anterior cruciate ligament reconstruction also did not significantly affect quadriceps muscle strength, but it did significantly decrease hamstring muscles strength only at 1 month. Activity-related soreness at the donor site was rarely restricting and resolved by 3 months. This study demonstrated that the semitendinosus and gracilis tendon graft is a reasonable choice to minimize the donor site morbidity in ligament reconstruction using autografts.

Activities of Daily Living↗
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Effects of resumption of loading on stress-shielded autografts after augmentation procedures. An experimental study.

An experiment was conducted to verify if resumption of loading (restressing) on autografts after augmentation procedures can recover the mechanical properties of the grafts that were deteriorated by complete stress shielding. One hundred ten Japanese White rabbits were used. After the patellar tendon in each right knee was frozen in situ, tension applied to the tendon was released for an interval in 80 rabbits. These 80 animals were divided into four groups of 20 rabbits. The patellar tendons in these groups were completely shielded from stress for 1, 2, 3, and 6 weeks, respectively. From each group, rabbits were sacrificed immediately before restressing (N = 5), and after 3 (N = 5), 6 (N = 5), and 12 (N = 5) weeks of restressing. The remaining 30 rabbits underwent sham operations. The results showed that complete stress shielding markedly decreased tensile strength of the patellar tendon. However, if restressing was applied within 3 weeks of complete stress shielding, the once-reduced strength gradually increased to the level of the sham-operated tendons by 12 weeks after the onset of restressing. Restressing applied after 6 weeks of complete stress shielding also increased the strength of the tendon; however, it reached only 65% the strength of the sham-operated tendons at 12 weeks after restressing. The timing to apply stress to grafts should be carefully determined for optimal recovery.

Animals↗
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Effects of initial graft tension on clinical outcome after anterior cruciate ligament reconstruction. Autogenous doubled hamstring tendons connected in series with polyester tapes.

We conducted a prospective, randomized, short-term study to clarify the effects of initial graft tension on clinical outcome after arthroscopically assisted anterior cruciate ligament reconstruction with autogenous doubled semitendinosus and gracilis tendons connected in series with polyester tapes. Seventy Japanese patients with chronic, "isolated" anterior cruciate ligament tears were entered in the study. The patients were randomly divided into three groups based on initial graft tension: Group 1 (20 N), Group 2 (40 N), or Group 3 (80 N). No statistical differences were noted among the three groups with regard to their background factors. The patients were observed for 2 years or more after surgery. Postoperatively, the average side-to-side difference in anterior laxity was 2.2 +/- 2.4 mm in Group 1, 1.4 +/- 1.8 mm in Group 2, and 0.6 +/- 1.7 mm in Group 3. Analysis of variance testing showed that the postoperative laxity in Group 3 was significantly less than that in Group 1. Spearman's rank-order correlation analysis also demonstrated significant correlation between the magnitude of initial graft tension and the magnitude of the postoperative laxity. This study demonstrates that relatively high initial tension (up to 80 N) reduces the postoperative anterior laxity of the knee joint after anterior cruciate ligament reconstruction using the doubled autogenous hamstring tendons connected in series with polyester tapes.

Adult↗
PubMedDate not supplied

Compensatory muscle activity in the posterior cruciate ligament-deficient knee during isokinetic knee motion.

We performed electromyographic analyses in 12 patients with posterior cruciate ligament-deficient knees to compare electrical activity in the quadriceps, hamstring, and gastrocnemius muscles between the uninjured and involved limbs. Each patient performed concentric isokinetic knee motion at 30 and 60 deg/sec in both limbs separately. Torques in knee extension and flexion and surface electromyograms from the quadriceps, medial hamstring, and medial gastrocnemius muscles were simultaneously recorded. The uninjured limb served as a control for each patient. Before generation of flexion torque, the gastrocnemius muscle was electrically activated significantly earlier in posterior cruciate ligament-deficient knees than in uninjured knees at each velocity. However, we could not find any significant differences between the posterior cruciate ligament-deficient and uninjured knees in torque curves and electromyelograms of the quadriceps and hamstring muscles. This study suggests that early contraction of the gastrocnemius muscle may be a part of a compensatory mechanism in posterior cruciate ligament-deficient knees.

Adolescent↗
PubMedDate not supplied

Nonoperative treatment of osteochondritis dissecans of the humeral capitellum.

We examined 24 patients with osteochondritis dissecans of the humeral capitellum to determine the results of nonoperative treatment. The average age of the patients at the initial examination was 13.3 years (range, 11 to 16). All the patients were advised to stop heavy use of the elbow for 6 months. At the last examination, at a mean follow-up period of 5.2 years, 4 patients (17%) had no residual elbow pain, 7 (29%) had pain only with heavy activities, and 13 (54%) had pain with activities of daily living. Final radiographs were obtained for 15 lesions, of which 3 lesions were assessed as healed, 3 as improved, and 9 as not improved. Five of 11 lesions in the early stage and all 4 advanced lesions failed to show radiographic improvement. These results suggest that osteochondritis dissecans of the capitellum has only a slight tendency to heal, and that instability can cause failure of the lesion to heal.

Activities of Daily Living↗
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Autoimmune hemolytic anemia and myasthenia gravis.

A case of autoimmune hemolytic anemia associated with myasthenia gravis in a 33-year-old female is presented. The association of autoimmune hemolytic anemia and myasthenia gravis is a very rare event, with only eight cases reported. The known association of these two diseases is reviewed. To our knowledge, this is the first reported case in which autoimmune hemolytic anemia preceded systemic myasthenia gravis.

Adult↗
PubMedDate not supplied

Long-term results of multiple muscle transfer to reconstruct shoulder function in patients with birth palsy: eleven-year follow-up.

We evaluated the long-term clinical results of multiple muscle transfer for reconstruction of shoulder function in 10 patients with birth palsy. Multiple muscle transfer consists mainly of Harmon's deltoid shift, Ober's biceps muscle transfer, and Hoffer's latissimus dorsi muscle transfer. The follow-up ranged from 5 to 14 years with an average of 10.5 years. Two of the 10 patients showed no improvement, one due to severely atrophied latissimus dorsi muscle, and the other who had not received Hoffer's latissimus dorsi muscle transfer. Except for these two patients, an averaged flexion and external angles were 114 degrees and 25 degrees, respectively. Harmon's deltoid shift and Hoffer's latissimus dorsi muscle transfer for reconstruction of shoulder function in patients with birth palsy have proven to be a useful method in reconstructing and maintaining the function of active elevation and external rotation of the shoulder.

Child↗
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Successful treatment with concurrent chemoradiotherapy followed by surgery for a patient with thymic adenocarcinoma.

Most neoplasms arising from the thymic epithelium are considered to be 'thymomas', which are composed of cytologically benign, neoplastic epithelial cells and nonneoplastic lymphocytes. In contrast, thymic epithelial neoplasms displaying cytologically malignant features have recently been classified as thymic carcinomas of various types of histology. However, primary thymic adenocarcinoma is extremely rare and only four cases of it have been reported in the literature. We report a rare case of primary thymic adenocarcinoma of 4-year complete remission with concurrent chemoradiotherapy followed by surgery. A 61-year-old Japanese man was referred to us complaining of facial edema and general fatigue. Computed tomography scans revealed a huge mass in the anterior mediastinum obstructing the superior vena cava. He was diagnosed with thymic adenocarcinoma on needle biopsy. He was treated with induction chemoradiotherapy consisting of cisplatin, 5-FU and concurrent thoracic radiation, which yielded a partial response. He then underwent surgical resection of the remaining mass. However, pathologic examination of the resected mass revealed no malignant cells. The patient is doing well without symptoms or signs of relapse 53 months after diagnosis.

Adenocarcinoma↗
PubMedDate not supplied

Myelopathy due to ossification or calcification of the ligamentum flavum: radiologic and histologic evaluations.

The clinical, radiologic, and histologic features of ossification and calcification of the ligamentum flavum were studied in 18 patients. Ossification (15 patients) usually occurred in the lower thoracic spine in men of various ages, while calcification (three patients) was found exclusively in the cervical region of older women. Histologic examinations of ossification showed mature lamellar bone associated with proliferated cartilage replacing the ligamentum flavum (endochondral ossification). This corresponded well with radiographic and computed tomographic (CT) appearances. In the cases with calcification of the ligamentum flavum, calcification within the degenerated ligamentous fibers was observed on histologic examination, and correlated well with an oval nodular density on radiographs and CT. The two conditions differ in clinical, radiologic, and histologic considerations. Pathomechanisms in the development of these lesions and clinical significance are also discussed.

Adult↗
PubMedDate not supplied

Flexion-relaxation phenomenon in the back muscles. A comparative study between healthy subjects and patients with chronic low back pain.

At a certain position of trunk flexion, there is a sudden onset of electrical silence in back muscles. This is called "flexion-relaxation (F-R) phenomenon." The goals of this study were (1) to evaluate the relationship between flexion angle and activity of back muscles during flexion movement and (2) to determine what the difference is between healthy subjects and patients with chronic low back pain (CLBP). Twenty-five healthy subjects (13 males and 12 females; average age, 28.3 yr) and 20 patients with CLBP (12 males and 8 females; average age, 34.1 yr) volunteered for this study. The subjects were asked to flex forward maximally from the erect position and to maintain full flexion, followed by returning to the initial upright position. Flexion angle of trunk and hip was measured during the examination. Electromyographic activity of erector spinae was also monitored simultaneously. F-R phenomenon was observed in all healthy subjects before reaching the maximum flexion. Electrical silence continued even after extending the trunk began. In contrast, no patients with CLBP demonstrated F-R phenomenon. A significant difference in muscular activities of erector spinae between the groups was obtained when returning to the erect position from the maximum flexion. Moreover, time lag between trunk and hip movement was much greater in patients than in healthy subjects. This study demonstrated that neuromuscular coordination between trunk and hip could be abnormal in patients with CLBP.

Adult↗
PubMedDate not supplied

Interleukin 12 augments the liver-associated immunity and reduces liver metastases.

BACKGROUND/AIMS: It has been reported recently that in vivo administration of interleukin-12 (IL-12) augments the cytotoxic activity of natural killer (NK)/T cells and shows a powerful anti-tumor activity. In this study, we evaluated that the IL-12 effect on liver-associated immunity and in vivo efficacy on the hepatic metastases in a rat model. MATERIALS AND METHODS: Varying amounts of mouse recombinant IL-12 were injected intraperitoneally for 5 days to adult male Fischer rats and hepatic sinusoidal lymphocytes (HSL) were collected. Purified HSL are spontaneously cytolytic to both conventional NK-sensitive target (YAC-1) and NK-resistant target (RCN-H4) tumor cells. RESULTS: IL-12 was found to increase the number of HSL and the cytolytic activity against these target cells in a dose-dependent fashion. Flow cytometric analysis showed that IL-12 caused an increase of CD8+ subpopulation in HSL and a double staining study revealed that the increased subpopulation was not CD3+8+ (cytotoxic T cell) fraction, but actually CD3-8+ (NK cell) fraction. Experimental liver metastases was markedly reduced in rats treated intraperitoneally with IL-12. CONCLUSION: These results demonstrate that IL-12 augments the cytolytic activity of HSL and suggests this cytokine as an attractive choice for liver metastases therapy.

Adjuvants, Immunologic↗
PubMedDate not supplied

Onset of ossification of the tarsal bones in congenital clubfoot.

Subjects of this study were 45 patients with 56 idiopathic congenital clubfeet (34 boys with 42 feet and 11 girls with 14 feet) who underwent successful conservative treatment. Radiologic examinations were performed at intervals of 3 months. In anteroposterior radiographs of bilateral feet, the period of appearance of the ossification center was observed for the first, second, and third cuneiform and the tarsal navicular. The ossification of the tarsal bones in the congenital clubfeet occurred later than that in the unaffected feet in boys. The difference between the clubfeet and the unaffected feet was particularly statistically significant for the tarsal navicular and the second cuneiform (p < 0.01). The tarsal naviculars, the first cuneiforms, and the second cuneiforms in clubfeet and in unaffected feet started to be ossified significantly earlier in girls than in boys. Ossification occurred out of order in three of 56 clubfeet and three of 34 unaffected feet.

Age of Onset↗