A questionnaire about radiation safety management of the draining-water system at nuclear medicine facilities

We conducted a questionnaire survey about radiation-safety management condition in Japanese nuclear medicine facilities to make materials of proposition for more reasonable management of medical radioactive waste. We distributed a questionnaire to institutions equipped with Nuclear Medicine facilities. Of 1,125 institutions, 642 institutes (52.8%) returned effective answers. The questionnaire covered the following areas: 1) scale of an institution, 2) presence of enforcement of radiotherapy, 3) system of a tank, 4) size and number of each tank, 5) a form of draining-water system, 6) a displacement in a radioactive rays management area, 7) a measurement method of the concentration of medical radioactive waste in draining water system, 8) planned and used quantity of radioisotopes for medical examination and treatment, 9) an average displacement of hospital for one month. In most institutions, a ratio of dose limitation of radioisotope in draining-water system was less than 1.0, defined as an upper limitation in ordinance. In 499 hospitals without facilities of hospitalization for unsealed radioisotope therapy, 473 hospitals reported that sum of ratios of dose limits in a draining-water system was less than 1.0. It was calculated by used dose of radioisotope and monthly displacement from hospital, on the premise that all used radioisotope entered in the general draining-water system. When a drainage including radioactivity from a controlled area join with that from other area before it flows out of a institution, it may be diluted and its radioactive concentration should be less than its upper limitation defined in the rule. Especially, in all institutions with a monthly displacement of more than 25,000 m3, the sum of ratio of the concentration of each radionuclide to the concentration limit dose calculated by used dose of radioisotope, indicated less than 1.0.     

Destructive Adsorption of Diazinon Pesticide by Activated Carbon Nanofibers Containing Al2O3 and MgO Nanoparticles

We report the destructive adsorption of Diazinon pesticide by porous webs of activated carbon nanofibers containing Al₂O₃ and MgO nanoparticles. The results show that, the presence of Al₂O₃ and MgO nanoparticles in the activated carbon nanofibers increases the amount of destructively adsorbed Diazinon pesticide by activated carbon nanofibers. Moreover, type, amount, and specific surface area of metal oxide nanoparticles affect the adsorption rate as well as the total destructively adsorbed Diazinon. Liquid chromatography proved the degradation of Diazinon by chemical reaction with Al₂O₃ and MgO nanoparticles. Liquid chromatography–mass spectrometry showed that the main product of reaction between Diazinon and the metal oxides is 2-isopropyl-6-methyl-4-pyrimidinol with less toxicity than Diazinon.     

Distribution of osteopontin and calprotectin as matrix protein in calcium-containing stone

We recently reported that osteopontin (OPN) and calprotectin (CPT) are present in the matrix of urinary calcium stones, and that OPN mRNA is expressed in the renal distal tubular cells. In the present study, we examined the immunohistochemical distributions of OPN and CPT in urinary stones. The stones used in this study were passed spontaneously from the upper urinary tract. One half of each of the stones was analyzed with an infrared spectrophotometer, and were shown to be comprised of calcium oxalate, calcium phosphate, uric acid and cystine. The other half of each stone was immersed in tetrasodium ethylenediamine-tetraacetate (EDTA) solution. The half-stones were embedded in paraffin and cut into 5-μm sections. The avidin-biotin-peroxidase complex technique was employed. A monoclonal antibody to human milk-derived OPN and a monoclonal antibody to human granulocyte-derived CPT were used as primary antibodies. The immunochemical study using the OPN and CPT antibodies showed positive staining of the matrix of the urinary calcium stones. The stones showed staining in two distinct zones: a core area was stained with randomly aggregated OPN and CPT, and peripheral layers were stained in concentric circles. On the basis of our observations, it is reasonable to presume that OPN and CPT play roles as the matrix in the structure of urinary calcium stones. Received: 24 February 1998 / Accepted: 28 January 1999     

Pathogenesis and treatment of chronic empyema

In chronic empyema (CE), thickened pleura, collapsed chest wall, and the accumulation of purulent fluid in the thoracic cavity are typical findings. Patients complaints of symptoms with bronchopleural fistula (BPF). On the other hand, there is another type of CE in which the pleural space expands progressively to shift the neighboring lungs, mediastinum, and diaphragm. This type of CE is considered to be chronic expanding hematoma (Reid et al.) occurring in the thoracic cavity. In the empyemic cavity, mycobacterial infection is found approximately in 20-30% of cases, pyogenic bacillus or fungus in about 40%, but the cavity is aseptic in other 30-40%. Although the fundamental treatment procedures include decortication and pleuropneumonectomy, the method of muscle or omental plombage to manage dead space or BPF are far superior functionally in intractable CE. Recently, the methods of plastic and reconstructive surgery have been used to utilize the muscle or omentum more effectively. The classic thoracoplasty procedure should not be undertaken unnecessarily to avoid additional deterioration of respiratory function. Additionally, it should be remembered that malignant lymphoma occurs frequently in the empyemic chest wall.     

In situ imaging of the autonomous intracellular Ca(2+) oscillations of osteoblasts and osteocytes in bone

Bone cells form a complex three-dimensional network consisting of osteoblasts and osteocytes embedded in a mineralized extracellular matrix. Ca(2+) acts as a ubiquitous secondary messenger in various physiological cellular processes and transduces numerous signals to the cell interior and between cells. However, the intracellular Ca(2+) dynamics of bone cells have not been evaluated in living bone. In the present study, we developed a novel ex-vivo live Ca(2+) imaging system that allows the dynamic intracellular Ca(2+) concentration ([Ca(2+)](i)) responses of intact chick calvaria explants to be observed without damaging the bone network. Our live imaging analysis revealed for the first time that both osteoblasts and osteocytes display repetitive and autonomic [Ca(2+)](i) oscillations ex vivo. Thapsigargin, an inhibitor of the endoplasmic reticulum that induces the emptying of intracellular Ca(2+) stores, abolished these [Ca(2+)](i) responses in both osteoblasts and osteocytes, indicating that Ca(2+) release from intracellular stores plays a key role in the [Ca(2+)](i) oscillations of these bone cells in intact bone explants. Another possible [Ca(2+)](i) transient system to be considered is gap junctional communication through which Ca(2+) and other messenger molecules move, at least in part, across cell-cell junctions; therefore, we also investigated the role of gap junctions in the maintenance of the autonomic [Ca(2+)](i) oscillations observed in the intact bone. Treatment with three distinct gap junction inhibitors, 18α-glycyrrhetinic acid, oleamide, and octanol, significantly reduced the proportion of responsive osteocytes, indicating that gap junctions are important for the maintenance of [Ca(2+)](i) oscillations in osteocytes, but less in osteoblasts. Taken together, we found that the bone cells in intact bone explants showed autonomous [Ca(2+)](i) oscillations that required the release of intracellular Ca(2+) stores. In addition, osteocytes specifically modulated these oscillations via cell-cell communication through gap junctions, which maintains the observed [Ca(2+)](i) oscillations of bone cells.     

Rotational acetabular osteotomy for osteonecrosis with collapse of the femoral head in young patients

BACKGROUND: While rotational acetabular osteotomy has been reported to be successful for the treatment of osteoarthritis of the dysplastic hip, little is known about its efficacy in the treatment of osteonecrosis of the femoral head. METHODS: We retrospectively reviewed the results for a consecutive series of twenty-one patients (twenty-five hips) who had undergone rotational acetabular osteotomy between 1995 and 2001 for the treatment of extensive osteonecrosis of the femoral head associated with collapse. All but two of the patients had a history of steroid therapy as part of a treatment regimen for various diseases. At the time of surgery, the mean age of the five men and sixteen women was 29.0 years. The mean duration of follow-up was forty-nine months. No patient was lost to follow-up. The lesions were classified according to the staging system described by Steinberg et al., and the extent of necrosis was measured with use of the criteria described by Kerboul et al. Clinical evaluation was performed with use of the scoring system of Merle d'Aubigne and Postel. Radiographic evaluation was performed with use of yearly serial anteroposterior and lateral plain radiographs. RESULTS: The mean Merle d'Aubigne and Postel score improved from 11.3 points preoperatively to 14.9 points at the time of the final follow-up (p < 0.001). The mean pain score improved from 3.0 to 5.6 points (p < 0.001). However, the mean mobility score was 5.3 points preoperatively but only 4.9 points postoperatively (p = 0.1). All of the osteotomy sites showed radiographic evidence of osseous union at the time of the latest follow-up. Collapse of the femoral head progressed in seven hips, but in six of these hips the change in the extent of collapse was <2 mm. CONCLUSIONS: In the present study of young patients with extensive osteonecrosis and collapse of the femoral head, rotational acetabular osteotomy was associated with symptomatic relief and absence of substantial collapse of the femoral head at the time of early to intermediate-term follow-up.     

Rectovaginal fistulas after rectal cancer surgery: Incidence and operative repair by gluteal-fold flap repair

BACKGROUND: We investigated the correlation between operative procedures for rectal carcinoma and postoperative rectovaginal fistulas (RVF), and treatment for RVF. METHODS: The medical records of 161 female patients with rectal carcinoma were examined retrospectively with respect to the cause, incidence, and methods of treatment for RVF occurring after rectal cancer operations, and to the outcomes of gluteal-fold flap repairs for RVF. RESULTS: Of the 161 patients, 16 developed RVF clinically. The incidence of RVF was significantly higher in patients who were anastomosed by the double stapling technique (DST) and had concomitant resection of the vaginal wall. No statistical difference was found between the established diverting ostomy group and the no-stoma group. Six patients recovered by the establishment of a diverting ostomy only. The gluteal-fold flap technique was performed for 5 patients. No RVF recurrences were noted in these 5 patients. CONCLUSIONS: The incidence of RVF was higher in the patients who were anastomosed by DST or had concomitant resection of the vaginal wall. Although some RVFs heal with only fecal diversion, for patients in whom RVF is caused by involvement of the vaginal wall in the circular staple or intersphincteric resection, good results are obtained with the gluteal-fold flap repair technique.     

Simultaneous bilateral percutaneous nephrolithotomy in children

In the paediatric section, two papers relating to the upper urinary tract are presented. The first, from Hungary, describes simultaneous bilateral percutaneous nephrolithotomy in 13 patients, where it was deemed feasible; this is the first such report. Authors from London report on unilateral nephrectomy in patients with nephrogenic hypertension, and found that it was successful in normalising blood pressure in patients with renal hypertension with a normal contralateral kidney. OBJECTIVE: To evaluate the efficacy of removing bilateral kidney stones simultaneously from children, in one session. PATIENTS AND METHODS: Thirteen patients (three girls and 10 boys, 26 kidneys; mean age 8 years, range 3-14) underwent simultaneous bilateral percutaneous nephrolithotomy (PCNL) in the same session, under general anaesthesia, starting with ureteric catheter insertion into both kidneys and using a 26 F adult nephroscope. The mean (range) stone diameter was 2 (1-3.5) cm. Three patients had staghorn stones in one of their kidneys. Ultrasonic disintegration was used; two patients had bilateral and two others unilateral endopylotomy, and one patient had percutaneous suprapubic cystolithotomy in the same session. The mean (range) operative duration was 65 (55-90) min. RESULTS: All patients were rendered stone-free; there was no severe bleeding or any other complication. On one side in one of the patients, a second session was needed because of residual stone. The nephrostomy tubes were removed 3 and 4 days after PCNL and the hospital stay was 6 (1-11) days. CONCLUSION: The advantages of simultaneous bilateral PCNL are reduced psychological stress, one cystoscopy and anaesthesia, less medication and a shorter hospital stay and convalescence, with considerable savings in cost. In experienced hands this method can be used not only in adults but also in children. To our knowledge this is the only report of this technique in children.     

Systematic laparoscopic left lateral segmentectomy of the liver for hepatocellular carcinoma

A systematic technique for the resection of hepatocellular carcinoma (HCC) prevents the dissemination of cancer cells through the portal vein of the remnant liver. We successfully performed a systematic laparoscopic left lateral segmentectomy in a 62-year-old man with HCC. The tumor was located in the left lateral segment of the liver, and measured approximately 4 cm in diameter. Since no other tumors were detected in the liver or in any distant organs, the patient was considered to be a candidate for surgery. A laparoscopic hepatic resection was selected as the procedure of choice. Prior to dissection of the liver parenchyma, the arteries and branches of the portal vein feeding the left lateral segment were divided and dissected, together with the branches of the biliary tree in the umbilical portion of the left pedicle of Glisson's capsule. The liver parenchyma was then dissected and the left hepatic vein divided and dissected, and transection of the left lateral segment was completed. The patient's postoperative course was uneventful and he was discharged on postoperative days 14. No evidence of recurrence has been noted in the 22 months after surgery (the time of this report). This less invasive surgery, taking into consideration the pathogenesis of HCC, may be a useful new approach in selected patients with this tumor. Received for publication on Sept. 1, 1997; accepted on Dec. 26, 1997