Endoscopic anterior cruciate ligament reconstruction using a computer-assisted fluoroscopic navigation system

Background During anterior cruciate ligament (ACL) reconstruction, placement of the reconstructed ligament affects the clinical results. To accomplish accurate and reproducible placement of the tibial bone tunnel, we employed a fluoroscopic navigation system for endoscopic ACL reconstruction. In this study, preciseness of the tibial tunnel placement was evaluated, and the advantages and disadvantages of this navigation system for endoscopic ACL reconstruction are discussed. Methods Altogether, 16 knees of 16 patients who had undergone ACL reconstruction using this system (navi group) were evaluated regarding the positioning of the tibial tunnel against Blumensaat's line using X-p and the route of the graft by magnetic resonance imaging (MRI). Another 16 knees of 16 patients who underwent endoscopic ACL reconstruction without the navigation system were the controls (control group). Results At the 1-year follow-up, maximally extended lateral knee X-p revealed that the anterior edge of the tibial tunnel and Blumensaat's line were almost aligned and that roof impingement was avoided; the T2-weighted MR images showed that the graft was placed close to and parallel to the intercondylar roof in all the knees of the navi group. The ratio of the distance between Blumensaat's line and the anterior edge of the tibial tunnel at the level of the tibial plateau to the anteroposterior width in fully extended true lateral radiographs was 2.7% ± 3.4% in the navi group and 8.4% ± 7.4% in the control group. Conclusions The computer-assisted fluoroscopic navigation system improves accuracy and decreases dispersion of the tibial tunnel placement against Blumensaat's line in single-bundle ACL reconstruction. This innovative device renders the reconstruction procedure more reliable, eliminating the problem of skeletal variation among patients. However, the function of this navigation system for femoral tunnel placement is insufficient at present. Further refinement of the system is necessary, and the method of application requires improvement.     

Adsorption of Human Recombinant Erythropoietin on Dialysis Membranes In Vitro

Abstract: The adsorptive characteristics of 5 dialysis membranes for recombinant human erythropoietin (EPO) were studied in vitro in a closed circuit system. For 120 min, EPO added with bovine serum was significantly adsorbed by polymethylmetacrylate (PMMA) and polyacry–lonitrile (PAN) membranes but not by Cuprophan, ethylene vinyl alcohol (EVAL), or polysulfone (PS) membranes. In addition the EPO adsorptive rate, as well as that of β₂–microglobulin (β₂–MG), was greater with a PMMA membrane than with a PAN membrane. EPO was not detected in the ultrafiltrate at 15 min with 5 membranes. These results indicate that EPO was eliminated by membrane adsorption only with some dialysis membranes.     

Determination of ion recombination loss by two-voltage method for pulsed radiation beams.

The ion recombination loss is one of the most important correction factors for dosimetry using ionization chamber especially for the measurement of high-intensity pulsed radiation beam. The two-voltage method has been used frequently for the correction of ion recombination loss. Several ways to approximate the method are presented. Comparisons were carried out to check the validity of the approximation. Using four ionization chambers of different types and shapes, measurements were made to obtain the optimal value of the ratio for the two voltages.     

Skip mediastinal nodal metastases in non-small cell lung cancer

Objective: To reveal the incidence and clinical significance of mediastinal nodal metastases without N1-station nodal metastases (‘skip-N2 metastases’) in non-small cell lung cancer (NSCLC). Methods: A total of 450 NSCLC patients who underwent tumor resection with a systemic mediastinal nodal dissection were retrospectively reviewed. p53 status and proliferative activity represented as proliferative index (PI) were also examined immunohistochemically. Results: Skip-N2 metastases were documented in 49 (13%) patients of all 450 patients; among 334 patients without N1-nodal involvement, 18% patients had skip-N2 metastases. The postoperative survival of skip-N2 patients was almost same as that for patients with metastases to both N1 and N2 nodes. Skip-N2 metastases were significantly more frequent in male patients and squamous cell carcinoma patients. In addition, the mean PI for tumor with skip-N2 metastases was significantly higher than that for any other pathologic nodal (pN)-status diseases. Combined with histologic type and PI, the incidences of skip-N2 metastases for adenocarcinoma showing lower PI were only 5% (7/137) of all patients and 7% (7/94) of patients without N1-nodal involvement. Conclusions: N1 nodal status is not a useful predictor of N2 nodal status in NSCLC, because skip-N2 metastases were documented in 18% patients showing no N1-nodal involvement. However, N1 node-guided dissection might be performed in patients with adenocarcinoma showing lower PI, because the incidence of skip-N2 metastases was extremely low.     

Production of human hematopoietic survival and growth factor by a myeloid leukemia cell line (KPB-M15) and placenta as detected by a monoclonal antibody

Fifty-five hematopoietic cell lines, including 19 T-, 16 B-, 5 pre-B-, 5 non-T non-B-, 1 erythroid, and 9 myeloid-monocytoid cells, were screened for production of human hematopoietic survival and stem cell growth factor (SCGF) by enzyme immunoassay using anti-SCGF monoclonal antibody. The KPB-M15 myeloid cell line constitutionally secreted a considerable quantity of SCGF, while other T- or myeloid-monocytoid cell lines did not secrete SCGF. Other biomaterials investigated were fetal calf, horse, and human serum; granulocyte-macrophage colony-stimulating factor and erythropoietin preparations; human placental conditioned medium; lectin (phytohemagglutinin, concanavalin A, and pokeweed mitogen); and mixed leukocyte reaction-stimulated leukocyte-conditioned medium. SCGF was detected only in human placental conditioned medium. SCGF produced by the KPB-M15 cells was a protein with a molecular weight of 20,000. The molecule, highly purified by immunoadsorbent affinity chromatography, retained SCGF activity in vitro, e.g., erythroid burst-promoting activity and granulocyte-macrophage-colony potentiation. With the availability of purified SCGF, it is now possible to study in detail the mechanisms regulating hematopoietic stem cells.     

Hemorrhagic cystitis after bone marrow transplantation: importance of a thin sectioning technique on urinary sediments for diagnosis.

We used a thin-sectioning technique for the electron microscopic detection of viral particles within the cells of urinary sediments in three recipients who developed hemorrhagic cystitis after allogeneic bone marrow transplantation. Results of viral cultures of urine and electron microscopic (EM) observations on urinary sediments were consistent in only one recipient. In this recipient, EM observations revealed many viral particles within the cells of urinary sediments with diameter of about 80 nm corresponding to adenovirus, of which type 11 was produced in viral cultures. In one of the other two recipients many viral particles with a mean diameter of 41.6 nm corresponding to papovavirus were observed, but viral cultures using conventional cells were negative. Re-cultures using HEK cells produced polyomavirus BK. EM observation was a clue to the correct diagnosis. In the remaining recipient, no viral particles were observed within the cells of urinary sediments, suggesting the hemorrhagic cystitis to be of non-viral origin, despite a positive result of viral culture. These results suggest that a thin-sectioning technique on the cells of urinary sediments is important for the differential diagnosis between a viral-induced and non-viral hemorrhagic cystitis.     

Epidemiological characteristics of acute pulmonary thromboembolism in Japan.

AIM: In Japan, acute pulmonary thromboembolism (APTE) is still rare, but the number of patients with APTE has been steadily increasing. It is important for early diagnosis and early management of APTE to recognize epidemiological characteristics of this condition. METHODS: We investigated the epidemiological characteristics of 252 patients with APTE who were admitted to our institutions between 1975 and 2001. APTE was more prevalent in women that in men. It was observed the most in the age group between 50s to 70s, especially in women. Many patients had prolonged immobilization, recent major operation, obesity, or cancer, as risk factors for venous thromboembolism. One hundred and thirty-eight patients developed APTE in hospital; 60 patients were in Department of Internal Medicine, 28 in General Surgery, 15 in Orthopedics, 15 in Obstetrics and Gynecology, and 20 in other services. RESULTS: Among 58 patients with malignancy, 43% had cancers in digestive organs, 21% in gynecological, and 17% in urological. Among 61 patients who were examined for the presence of thrombophilia, 13 patients had inherited thrombophilia (8 protein C deficiency, 4 protein S deficiency, and 1 antithrombin III deficiency) 11 had antiphospholipid antibodies which indicated thrombophilia. Five out of the above 61 patients (8%) had no obvious risk factors including thrombophilia. CONCLUSION: The findings in our patients were almost the same as those in Western patients, except for some points. These results might be useful to establish a preventive approach for APTE in Japan.