Radiation tolerance of the cochlear nerve at the γ-knife in rabbits

Since the first treatment of acoustic neurinoma using the γ-knife by Leksell, a series of cases have been reported with good control rates. However, the most frequent complication is delayed hearing loss which occurs in more than 50% of patients. The purpose of this study was to define a safe dose by analyzing the radiosurgical dose-response relationship and histological effects on the normal cochlear nerve in rabbit. The rabbits had computed tomography (CT)-guided stereotactic radiosurgery on their cochlear nerves in the internal auditory canal with a 4 mm collimator focusing of a γ-unit. Maximum doses of 10, 20, 30, 40, 60, 80, 100, 200 and 500 Gy were administered. After the radiosurgery, auditory brain stem responses (ABR) and the behavior of the rabbits were evaluated periodically. At the conclusion, histological investigations were performed. No physiological or histological findings were observed from doses of 30 Gy or below during the 12 month period after the radiosurgery. A dose of 100 Gy caused a severe ABR threshold elevation, vestibular dysfunction and facial palsy. Necrosis and demyelination of nerves were observed pathologically. In this study, we determined that the safe dose to the normal cochlear nerve during radiosurgery was under 40 Gy in rabbits, and complications seemed to vary due to individual differences in radiation tolerance.     

Infantile hemangioendothelioma of the thymus with massive pleural effusion and Kasabach-Merritt syndrome: Histopathological, flow cytometrical analysis of the tumor

Infantile hemangioendothelioma of the thymus is a rare disease. We describe a patient who developed a large anterior mediastinal mass, severe thrombocytopenia and massive pleural effusion at 1 month of age. Glucocorticosteroid and irradiation therapy had no effect on either the tumor size or clinical symptoms and the tumor was resected subtotally. Three months after the subtotal resection, the remaining tumor had almost disappeared and the symptoms had resolved. The patient has now been well for 1 year after surgery without evidence of recurrence. The tumor tissue was characterized by prominent vascular endothelial proliferation intermixed with a normal thymic structure, producing a picture consistent with that of an infantile hemangioendothelioma in the thymus, lmmunohistochemically, the tumor cells showed positive staining for vimentin, factor VIII and CD34. The DNA stemline and proliferative activity were examined by flow cytometry, which revealed a diploid stemline with a low growth fraction. DNA content and cell cycle analyses of the tumor tissue may be useful for predicting the biological behavior of the tumor.     

Antisense RNA-mediated reduction of p53 induces malignant phenotype in nontumorigenic rat urothelial cells

p53 mutation is commonly associated with high-grade, high-stage human urothelial carcinomas. Recent studies suggest that p53 mutation in low- grade, low-stage bladder carcinomas may be correlated with the progression of the disease. In the present study, we used antisense RNA methodology in vitro to evaluate the significance of the loss of p53 function at an early stage of urinary bladder carcinogenesis. An immortalized nontumorigenic rat urothelial cell line (MYP3) that strongly expresses wild-type (WT) p53 was transfected with a plasmid (pcDL-SR alpha-296) containing a rat WT p53 cDNA in antisense orientation. The transfection resulted in a significant reduction in p53 mRNA expression and protein synthesis, in stimulation of anchorage- dependent growth, and in acquisition of anchorage-independent growth potential. Three such clones, when tested in athymic nude mice, all formed muscle-invasive, high-grade transitional cell carcinomas at s.c. injection sites. When cells were inoculated into an orthotopic site (urinary bladder), one of two antisense transfectants tested formed bulky tumors in the bladder in all seven nude mice and metastases to lungs in three of the seven mice. Analysis of these cells revealed a decrease in the expression of p21 (WAF1, sdi1, or CIP1) and retinoblastoma (Rb) gene product. Phosphorylation of Rb protein was not inhibited when the cells were starved. No significant difference was observed in the expression of p16 protein. In cell cycle analysis, all antisense transfectants tested escaped from G1 arrest by starvation. Furthermore, secretion of interleukin (IL)-6 into culture medium was increased significantly. Treatment with anti-IL-6 antibody suppressed anchorage-dependent growth. This study directly demonstrates that the loss of p53 function at an early stage of urothelial carcinogenesis may result in acquisition of a malignant phenotype by regulating IL-6 production as well as cell cycle related genes.      

A New Indole Derivative Isolated from the Root of Tuber Fleeceflower

从何首乌（PolygonummultiflorumThunb.）的根中分离出11个化合物，根据光谱学分析分别鉴定为：大黄酚（chrysophanol，Ⅰ）、大黄素甲醚（physcione，Ⅱ）、大黄素（emodin，Ⅲ）、ω-羟基大黄素（citreorosein，Ⅳ）、大黄酚8－O-β-D-吡喃葡萄糖苷（chrysophanol8-O-β-D-glucopyranoside，Ⅴ）、大黄素甲醚8-O-β-D-吡喃葡萄糖苷（Physcione8-O-β-D-glucopyranoside，Ⅵ）、大黄素8-O-β-D-吡喃葡萄糖苷（emodin8-O-β-D-glucopyranoside，Ⅶ）、决明酮8-O-β-D-吡喃葡萄糖苷（torachrysone8-O-β-D-glucopyranoside,Ⅷ）、2，3，5，4′-四羟基芪2-O-β-D-吡喃葡萄糖苷（2，3，5，4′－tetrahydroxystilbene2-O-β-D-glucopyranoside，Ⅸ）、没食子酸甲基酯（methylgallate，Ⅹ）和吲哚-3－（L-α-氨基-α-羟基内酸）甲酯[Indole－3－（L－α－amino－α－hydroxypropionicacid）methylester]。其中，化合物Ⅺ为新的天然产物。上述蒽醌和萘类化合物以及芦荟大黄素（aloe－emodin，Ⅻ）、大黄酸（rhein，）、芦荟大黄素8－O-β-D-吡喃葡萄糖苷（aloe－emodin8－O-β-D－glucopyranoside，）、大黄酚8－O-β-D－（6′－O-丙酰基）吡喃葡萄糖苷（chrysophanol8-O-β-D-（6′－O－malonyl）glucopyra－     

Metabolism of 2 alpha-propoxy-1 alpha,25-dihydroxyvitamin D3 and 2 alpha-(3-hydroxypropoxy)-1 alpha,25-dihydroxyvitamin D3 by human CYP27A1 and CYP24A1.

Recently, we demonstrated that some A-ring-modified vitamin D3 analogs had unique biological activity. Of these analogs, 2alpha-propoxy-1alpha,25(OH)2D3 (C3O1) and 2alpha-(3-hydroxypropoxy)-1alpha,25(OH)2D3 (O2C3) were examined for metabolism by CYP27A1 and CYP24A1. Surprisingly, CYP27A1 catalyzed the conversion from C3O1 to O2C3, which has 3 times more affinity for vitamin D receptor than C3O1. Thus, the conversion from C3O1 to O2C3 by CYP27A1 is considered to be a metabolic activation process. Five metabolites were detected in the metabolism of C3O1 and O2C3 by human CYP24A1 including both C-23 and C-24 oxidation pathways. On the other hand, three metabolites of the C-24 oxidation pathway were detected in their metabolism by rat CYP24A1, indicating a species-based difference in the CYP24A1-dependent metabolism of C3O1 and O2C3 between humans and rats. Kinetic analysis revealed that the Km and kcat values of human CYP24A1 for O2C3 are, respectively, approximately 16 times more and 3 times less than those for 1alpha,25(OH)2D3. Thus, the catalytic efficiency, kcat/Km, of human CYP24A1 for O2C3 is only 2% of 1alpha,25(OH)2D3. These results and a high calcium effect of C3O1 and O2C3 in animal experiments using rats suggest that C3O1 and O2C3 are promising for clinical treatment of osteoporosis.     

DNA Fragmentation in Central Nervous System Vascular Malformations

Recent studies have shown that apoptosis plays an important role in vascular remodeling. We examined central nervous system vascular malformations for the presence of DNA fragmentation which is the evidence of apoptosis. We hypothesize that vascular remodeling through apoptosis may be responsible for recurrence or hemorrhage in these lesions. We examined the specimens of central nervous system vascular malformations by in situ end labeling (ISEL) of fragmented DNA. Moreover, we examined the expression of Caspase-3 which is apoptosis-related proteins in these lesions by immunohistochemistry. DNA fragmentation was observed in all 15 arteriovenous malformation (AVM) specimens. ISEL-positive cells were mainly distributed in the endothelium, media and perivascular tissue. In cavernous hemangioma (CH), DNA fragmentation was also observed in all 5 specimens. ISEL-positive cells were distributed in the endothelium, subendothelium and intercavernous matrix. Thirteen out of 15 AVM lesions stained positive for Caspase-3. Caspase-3 immunoreactivity was mainly distributed in the endothelium, media and perivascular tissue. This distribution was similar to that of ISEL positive cells. As for CHs, all 5 lesions stained positive for Caspase-3. Caspase-3 immunoreactivity was distributed in the endothelium, subendothelium and intercavernous matrix. Our findings indicate that apoptotic cell death and vascular remodeling play a role in the development and maintenance of vascular malformations.     

Behavioral outcome including attention deficit hyperactivity disorder/hyperactivity disorder and minor neurological signs in perinatal high-risk newborns at 4−6 years of age with relation to risk factors

BACKGROUND: Diagnostic problems with the criteria of attention deficit hyperactivity disorder (ADHD) in the Diagnostic Statistical Manual, 4th edn, have been identified. The aim of this study was to clarify whether the minor neurological signs test (MNT) the authors had previously reported was a predictor for the criteria of ADHD or hyperactivity disorder (HD) in perinatal risk children at 4-6 years of age and what kind of risk factors related to MNT. METHODS: A total of 136 children discharged from neonatal intensive care units were examined at the age of 4-6 years by a developmental neuropediatrician using both MNT and diagnostic criteria of DSM-IV ADHD/ICD-10 (International Classification of Diseases, 10th edn) HD. SPSS base and professional were used for statistical analysis. RESULTS: On comparison of diagnostic criteria between ADHD (11.0%) and HD (27.5%), the incidence in the same subjects showed significant difference. MNT scores showed significant correlation with criteria of ADHD (P < 0.01) and HD (P < 0.05). Diagnostic validity of MNT for predicting ADHD was demonstrated with 78% sensitivity and 79% specificity. High positive rates on MNT did not show a significant difference between the very low birthweight (VLBW) and non-low birthweight (NLBW) groups. Behavioral outcome with relation to risk factors were analyzed using multiple regression analysis. Apgar 5 in the NLBW group and toxemia of pregnancy and small for gestational age (SGA) in VLBW group were highly correlated with behavioral outcome. CONCLUSIONS: Minor neurological signs test score was a significant predictor for criteria of ADHD and HD. High incidences of positive MNT were suspected in not only VLBW children but also NLBW children and Apgar 5 in NLBW children and toxemia of pregnancy and SGA in VLBW children influenced behavioral outcome.     

Transverse fundal uterine incision in a patient with placenta increta.

In cases with placenta accreta occurring on the previous cesarean scar, a longitudinal incision is generally appropriate. However, the placenta may prevent both a longitudinal and lower transverse incision. We report a case of placenta increta on the previous cesarean scar, and discuss the role of transverse fundal uterine incision.     

Potential role of vacuolar H-adenosine triphosphatase in neointimal formation in cultured human saphenous vein

OBJECTIVE: Vacuolar H(+)-adenosine triphosphatase plays a pivotal role in pH regulation and molecular transport across the vacuolar membranes and is involved in cell proliferation and transformation. In the present study, possible involvement of vacuolar H(+)-adenosine triphosphatase in neointimal formation was investigated in an organ culture model of human saphenous vein. Methods and results: Cultured saphenous vein segments developed neointimal formation and marked thickening of the media within 14 days. Neointimal formation and medial thickening were completely inhibited by 10 nmol/L bafilomycin A(1), a selective inhibitor of vacuolar H(+)-adenosine triphosphatase, although structurally related macrolide antibiotics FK-506 and erythromycin were without an effect. The neointimal cells were positive for alpha-smooth muscle actin and vimentin but negative for desmin, indicative of myofibroblasts. The emergence of myofibroblasts was inhibited, and endothelial cells were preserved in the saphenous vein segments treated with bafilomycin A(1). Uptake of bromodeoxyuridine, a proliferation marker, by myofibroblasts was abrogated in the saphenous vein segments treated with 10 nmol/L bafilomycin A(1). Detection of apoptotic cells by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling concomitant with identification of desmin-expressing smooth muscle cells demonstrated that neointimal myofibroblasts, but not medial smooth muscle cells, that expressed desmin underwent apoptosis by treatment with bafilomycin A(1). CONCLUSIONS: These results suggest that vacuolar H(+)-adenosine triphosphatase may be involved in myofibroblast growth that contributes to neointimal formation and medial thickening in cultured human saphenous vein. Increased sensitivity of myofibroblasts, but not endothelial cells, and differentiated smooth muscle cells to bafilomycin A(1) may have potential therapeutic implications in the treatment for vein graft disease.