Osteosarcoma occurring in osteogenesis imperfecta

We describe a case history of a 24-year-old male with osteogenesis imperfecta (OI) who developed osteosarcoma of the left thigh. High-dose ifosfamide therapy caused marked tumor regression of multiple lung metastases. Immunohistochemically, the tumor cells were diffusely positive for the p53 protein. Mutation of the p53 gene was not detected by direct genomic sequencing of exons 4–8. The radiographic characteristics, including irregularly distributed osteolytic lesions and cortical discontinuity, should not be confused with hyperplastic callus formation, a benign process. A biopsy is critical to establish the differential diagnosis between osteosarcoma and common hyperplastic callus formation in OI; however, it must be applied with great care.     

Effects of MEK on kinetics ofn-hexane metabolites in serum

The neurotoxicity ofn-hexane is thought to be caused ultimately by 2,5-hexanedione (2,5-HD), one of then-hexane metabolites. The potentiation ofn-hexane neurotoxicity by co-exposure with MEK, therefore, is suspected to be related to kinetics of 2,5-HD in blood. To clarify the kinetics ofn-hexane metabolites in the mixed exposure ofn-hexane and MEK, rats were exposed to 2000 ppmn-hexane or a mixture of 2000 ppmn-hexane and 2000 ppm MEK, and the time courses of serumn-hexane metabolites were determined. 2,5-HD in serum increased until 2 h after the end of exposure, when serum 2,5-HD concentration reached a peak of 16.35 g/ml in then-hexane-alone group. In contrast, 2,5-HD in the mixed exposure group increased much more slowly during and after exposure than in then-hexane-alone group. It reached a peak of 2.12 g/ml at 8 h after the end of exposure. Serum MBK, a precursor of 2,5-HD in the co-exposure group, was about half in then-hexane-alone group during exposure. However, MBK decreased more slowly in the co-exposure group than in then-hexane-alone group after the end of the exposure. The results suggest that co-exposed MEK might inhibit oxidation ofn-hexane and decrease clearance ofn-hexane metabolites. Co-exposed MEK did not increase serum 2,5-HD, which was considered a main neurotoxic metabolite. Therefore the enhancement of neurotoxicity could not be attributed to increased serum 2,5-HD in the co-exposed group. The mechanism of enhancement of neurotoxicity ofn-hexane by MEK should be studied further.     

Effect of irradiation on transforming growth factor-β secretion by malignant glioma cells

Glioblastoma cells secrete transforming growth factor- (TGF-), whichhas a variety of immunosuppressive properties. We investigatedthe effect of irradiation TGF- secretion by malignantglioma cells. Three malignant glioma cell lines (T98G,A172, KG-1-C) were cultured and irradiated using 10and 50 Gy Linac radiation. After further culturefor 36 hours in serum-free culture medium, thesupernatants were collected. The TGF- activity in theculture supernatants was determined using a specific bioassay.The levels of the active form and totalTGF- in the supernatants from irradiated malignant gliomacells decreased compared to those from un-irradiated cells.However, since irradiation inhibited the growth of tumorcells, the amount of TGF- secretion per cellin irradiated cells tended to increase after irradiation.These results suggest that malignant glioma cells canstill secrete TGF- and activate latent TGF- evenafter large dose irradiation, despite the inhibition oftumor growth.     

Use of a pericardial fat pad flap for preventing bronchopleural fistula: An experimental study focusing on the angiogenesis and cytokine production of the fat pad

An experimental study was conducted to determine whether pericardial fat tissue could induce neovascularization and produce cytokines related to tissue repair. Neovascularization was examined using chick chorioallantoic membranes. Pieces of pericardial fat tissue, omentum, and intercostal muscle were individually placed on a number of chorioallantoic membranes and neovascularization induced by each material was assayed 6 days after the implantation. The intensity of neovascularization was in the order of pericardial fat omentum > muscle. Cytokines, such as interleukin 1 (IL-1) and , tumor necrosis factor- (TNF), interferon- (IFN-), and interleukin 6 (IL-6) were assayed in a culture supernatant of pericardial fat tissue. The latter was obtained 24h after the addition of lipopolysaccharide (LPS) following various incubation times. All cytokines other than IFN are known to play a part in tissue repair, whereas IFN is negatively related to tissue repair because it inhibits fibroblast growth. The pericardial fat tissue incubated with LPS produced a certain amount of IL-1 on day 1, and TNF on days 1 and 8, whereafter these values decreased to an undetectable level. Irrespective of the addition of LPS, a large amount of IL-6 was observed in the supernatant of pericardial fat tissue and it was detectable until day 29. On the contrary, INF was not detected at any assay time. These observations suggest that a pericardial fat pad flap could possibly be beneficial in the prevention of bronchopleural fistula after pulmonary resection.     

Bone mineral density in patients with ossification of the posterior longitudinal ligament in the cervical spine

Bone mineral density (BMD) has not been clearly determined in patients with ossification of the posterior longitudinal ligament (OPLL) in the cervical spine. BMD in patients with OPLL was measured in the third vertebral body in the lateral projection and in the distal part of the radius in the anteroposterior projection using dual-energy X-ray absorptiometry (DXA). Patients with OPLL had significantly higher BMD than healthy controls in both the lumbar spine and radius. Observing BMD by gender and age group, high BMD was recognized especially in female patients over 60 years of age. Significantly increased BMD was observed in patients with ankylosing spinal hyperostosis (ASH) in addition to OPLL. These findings suggest that patients with OPLL may tend to develop systemic hyperostosis, leading to the pathological ectopic ossification observed in OPLL. Received: July 7, 1998 / Accepted: March 17, 1999     

Acute toxicity,percutaneous absorption and effects on hepatic mixed function oxidase activities of 2,4,4′-trichloro-2′-hydroxydiphenyl ether (Irgasan® DP300) and its chlorinated derivatives

Acute toxicity of 2,4,4-trichloro-2-hydroxydiphenyl ether (Irgasan^® DP300) (I) and its three chlorinated derivatives, 2,3,4,4-tetrachloro-2-hydroxydiphenyl ether (II), 2,4,4,5-tetrachloro-2-hydroxydiphenyl ether (III) and 2,3,4,4,5-pentachloro-2-hydroxydiphenyl ether (IV), in mice were examined by intraperitoneal injection. The LD₅₀ values of Irgasan DP300, II, III and IV were 1,090, 710, 650 and 430 mg/kg, respectively.The percutaneous absorptions of these tritiated compounds were also examined by the application on the backs of mice. The radioactivities in most tissues reached to the maximal levels at 12 h or 18 h after dosing, which corresponded to 11–76% of the maximal levels given by the oral administration (Kanetoshi et al. 1988a). These results show the high percutaneous absorbability of Irgasan DP300 and its chlorinated derivatives.The intraperitoneal administrations of III and IV to rats induced hepatic microsomal aminopyrine N-demethylase and aniline 4-hydroxylase activities similarly to phenobarbital. These chlorinated derivatives also increased cytochrome P-450 content, and the activities of aminopyrine N-demethylase and N-methylaniline N-demethylase in hepatic microsomes from mice. The extents of the increases were similar to those by phenobarbital and 3-methylcholanthrene.     

Subjective and functional results after total gastrectomy: prospective study for longterm comparison of reconstruction procedures

Background: Many reconstruction procedures have been developed in efforts to resolve patients' complaints after total gastrectomy. However, there have been few reports of longterm comparisons between reconstruction procedures, especially with regard to the prevention of duodenal food passage. This study was undertaken to compare the longterm subjective and functional results among Roux-en-Y esophagojejunostomy (R-Y), R-Y with pouch (P-Y), and jejunal interposition with pouch (P-I) after total gastrectomy. Methods: Consecutive patients requiring curative total gastrectomy were enrolled in this prospective study by the envelope method. Results: Hospital stay was longer following a P-I than an R-Y or a P-Y. Over 50% of R-Y patients complained of heartburn, and 20% of R-Y patients showed dumping syndrome throughout the postoperative period, with this rate being significantly different from rates in the other two groups. P-Y patients complained of early satiety in the late postoperative period, while P-I patients complained of early satiety in the early postoperative period. The nutritional index in P-I patients was higher than those in patients with the other two procedures. Gastrointestinal and hepatobiliary dual scintigraphy (GHDS) showed that the rate of bile reflux with an R-Y was relatively high after surgery. Food reflux with a P-Y was increased (9.4% to 11.1%), but with a P-I food reflux was decreased at 3 years after surgery (13.3% to 9.9%). Patients with a P-Y had a faster recovery of body, weight in the early postoperative period; however, at 5 years after operation, body weight recovery with a P-I was greatest. Conclusion: Reconstruction should be performed with pouch formation after total gastrectomy with curative intent. Received: March 7, 2002 / Accepted: September 26, 2002 Acknowledgments This study was partly supported by the University of Tsukuba Research Project. Offprint requests to: S. Adachi     

Triggers of hair cell regeneration in the avian inner ear

We performed an in vitro study in order to determine possible triggers of hair cell regeneration in the chick basilar papilla following degeneration. We compared the response of sensory epithelium damaged by collagenase treatment with that damaged by acoustic trauma. The former exhibited no proliferative activity, but the latter did. The basilar papillae damaged by acoustic trauma could have proliferating activity in medium containing fetal bovine serum (FBS) or epidermal growth factor (EGF) but not in the medium without FBS or EGF. These findings indicate that regeneration of basilar papillae depends on the manner of cell death and that FBS or EGF is required for regeneration.     

Motor Innervation of the Guinea Pig Interarytenoid Muscle: Reinnervation Process Following Unilateral Denervation

The authors investigated the process of denervation and reinnervation of the interarytenoid (IA) muscle in the guinea pig using transmission electron microscopy and glycogen depletion technique after unilateral transection of the recurrent laryngeal nerve (RLN) and superior laryngeal nerve to clarify the innervation pattern of the unpaired IA muscle. Anastomosis between the bilateral arytenoid branches was confirmed in the belly of the IA muscle. Five weeks after transection, all of the IA muscle fibers appeared to have been reinnervated by the contralateral RLN. As the arytenoid branch of the RLN runs together with that of the contralateral RLN in a single intramuscular nerve funiculus, it is possible that collateral sprouting branches grow and extend into the adjacent denervated Schwann's sheaths. The authors conclude that the unpaired IA muscle, as a whole, receives specific motor nerve supply from the bilateral RLNs, although each muscle fiber is innervated unilaterally.     

Targeted Gene Transfer for Adenocarcinoma Using a Combination of Tumor-specific Antibody and Tissue-specific Promoter

We have developed a highly specific gene transfer method for adenocarcinoma using a monoclonal antibody against tumor-specific antigen coupled with a plasmid containing the carcinoembryonic antigen (CEA)-specific promoter. The chimeric CEA promoter (CC promoter), which contained an enhancer from the immediate early gene of cytomegalovirus and the CEA promoter, achieved 4- to 5-fold higher transgene expression in CEA-producing cells than the original CEA promoter while maintaining CEA specificity. Furthermore, a complex of a monoclonal antibody against Lewis Y antigen (LYA), the CC promoter-containing plasmid and cationic liposomes (DOTAP) achieved specific gene expression in CEA-producing and LYA-positive adenocarcinoma cell lines that was 200-fold more efficient than in CEA-non-producing and LYA-negative cell lines during a short in vitro incubation. This strategy may be applicable for clinical gene therapy.