The use of thrombomodulin to study epithelial cell differentiation in neoplastic and non-neoplastic oral lesions

Thrombomodulin (TM) is a glycoprotein originally isolated from rabbit lung vasculature and characterized as a natural endothelial anticoagulant. Thrombin binds to TM noncovalently with high affinity. Thrombin-TM complexes can activate protein C efficiently. Activated protein C inactivates factors Va and VIIIa and regulates the blood coagulation cascade. Thus TM converts thrombin from a procoagulant protease to an anticoagulant. TM is found on endothelial cells in veins, arteries and capillaries. Our previous study has shown that TM is also expressed on the cell surface of squamous epithelium. In the present study, we aimed to disclose differences in TM expression among normal, dysplastic, and malignant squamous epithelium in human oral mucosa by counting TM-positive cells in each lesion. TM was uniformly expressed in the spinous layer of normal human oral squamous epithelium. The number of TM-positive cells was not significantly different between normal epithelium, lichen planus and mild dysplasia. In contrast, in moderate and severe dysplasia and well-differentiated squamous cell carcinoma (SCC), there were significantly fewer positive cells compared with normal epithelium. In SCCs, the periphery and the central keratinized area of tumor islands were often negative. The proportion of TM-positive cells in poorly differentiated SCC was significantly lower than in well-differentiated SCC. These results indicate that TM may have diagnostic value in the histological examination of oral premalignant and malignant lesions.     

Sequence analysis of the genome of the unicellular cyanobacterium Synechocystis sp. strain PCC6803. I. Sequence features in the 1 Mb region from map positions 64% to 92% of the genome

The contiguous sequence of 1,003,450 bp spanning map positions 64% to 92% of the genome of Synechocystis sp. strain PCC6803 has been deduced. Computer analysis of the sequence predicts that this region contains at least 818 potential ORFs, in which 255 (31%) were either genes that had already been identified or their homologues, 84 (10%) were homologues to registered hypothetical genes, and 149 (18%) showed weak similarities to reported genes. The remaining 330 ORFs showed no apparent similarity to any reported genes or carried no significant protein motifs. The potential ORFs as a whole occupied 86% of the sequenced region, implying compact arrangement of genes in the genome. As to the structural RNA genes, one rRNA operon consisting of 5,028 bp and at least 11 species of tRNA genes were identified. It is noteworthy that 10 out of the 11 tRNA species showed significant sequence similarities to tRNAs reported in plant chloroplasts. As other notable unique sequences, three classes of IS-like elements each with characteristics typical of IS elements were identified, and a typical unit of WD(Trp-Asp)-repeats which have only been detected in the regulatory proteins of eukaryotes was identified within the large 5,079-bp ORF located at map position 69%.     

Delayed gastric emptying in a neonate, associated with a partial defect in the gastric smooth muscle

A girl born after 36 weeks' gestation had emesis 15 hours after birth. She required total parenteral nutrition (TPN) because of persistent gastric retention. When milk was given, the volume of gastric aspirate 3 hours after feeding often was greater than the volume given. Domperidon and erythromycin were ineffective. Upper gastrointestinal series showed slow gastric emptying but no abnormalities in the stomach. No stenosis or obstruction below pylorus was found. Endoscopy showed normal gastric mucosa. Manometry showed normal antroduodenal motility patterns. Transpyloric feeding, which started at age 73 days, was successful and enabled cessation of the TPN. Laparotomy at 119 days of age showed partial absence of the muscle and serosal layer in the anterior wall of the gastric body (1 x 4 cm). The mucosal layer was intact and partly adhered to the peritoneum and the left lobe of the liver. The defect was surgically corrected by plicating the place. The postoperative course was excellent, and oral feeding was fully established within 2 weeks. Although the cause of the partial muscle defect in the case is unclear, this case suggests that this rare condition can cause severe chronic gastric retention.     

Percutaneous renal cyst puncture with CO2 instillation therapy

Ultrasound-guided percutaneous puncture of renal cysts replaced by CO2 was performed on 9 renal cysts of 6 patients from May 1993 through September 1993. Puncture and aspiration of cysts was performed using a 5.5 Fr one-step fluid drain kit (pig tail stent) under ultrasonography inspection. Aspirated volume of cyst contents was 15-292ml (mean 115 ml), and the instilled CO2 volume was 15-150 ml (mean 73 ml). All patients were checked by CT scan. In one month, the reduction rate of cyst volume was 46-84% (mean 69%) and lumbago, their chief complaint, was improved in all patients. No complications were observed in patients treated by CO2 instillation. Although long-term followup is needed to draw a definite conclusion, this therapy may be useful for benign renal cystic lesions.     

Experimental study of the pathogenesis of acute acalculous cholecystitis: role of autonomic denervation

This study was undertaken to elucidate the role of autonomic denervation in the pathogenesis of acute acalculous cholecystitis. In Experiment I, the gallbladder was denervated by performing either celiac neurotomy (sympathetic denervation) or truncal vagotomy (parasympathetic denervation), or both, in dogs. In Experiment II, 45-min ischemia and 90-min reperfusion of the gallbladder with or without autonomic denervation were performed by simultaneously occluding the middle hepatic artery and superior mesenteric vein. Celiac neurotomy, and truncal vagotomy, or both, did not cause cholecystitis. Sympathetic denervation, however, decreased the amount of mucin in the gallbladder mucosa and parasympathetic denervation caused reduction of the tissue blood flow, as well as the accumulation of lipid peroxide and xanthine oxidase in the gallbladder mucosa. These changes were most remarkable 1-2 weeks after denervation and were alleviated 4 weeks after denervation. Ischemia-reperfusion 2 weeks after denervation caused more severe cholecystitis than ischemia-reperfusion alone. The most severe inflammation developed in animals that received both celiac neurotomy and truncal vagotomy. These results suggest that autonomic denervation alone does not induce acute cholecystitis, but that it plays an important role in the progression of the inflammatory process in ischemia-reperfusion injury.     

Life of Magnetic Electroless Co-P Thin Films

Effective life of electroless Co-P (2.5 wt%) thin films of about 100 nm in thickness was evaluated for both magnetic characteristics and corrosion. The Co-P films were grown on rigid Al substrates overcoated with nonmagnetic Ni-P thick films and were finally covered with electroplated Rh thin films of 120 nm - 180 nm in thickness. The life of the magnetic characteristics was defined as the time to reach 10% deviation from the initial values of Hc (coercive force), Br (remanence), and S (squareness of hysteresis loop). The life of the films for corrosion was defined as the induction period of corrosion. An increase of Hc was observed above 80°C for isothermal annealing, but Br and S were unchanged. The activation energy of the variation of Hc was approximately 0.7 eV below 144°C. The life of magnetic characteristics was estimated to be approximately 4.1 × 104 ? 2.3 × 105 hrs at 55°C corresponding to the allowable maximum temperature in field service. The life for corrosion was influenced by the quality of Rh films.     

D-lactic acid production by metabolically engineered Saccharomyces cerevisiae

Poly D-lactic acid is an important polymer because it improves the thermostability of poly L-lactic acid by the stereo complex formation. We constructed a metabolically engineered Saccharomyces cerevisiae that produces D-lactic acid efficiently. In this recombinant, the coding region of pyruvate decarboxylase 1 (PDC1) was completely deleted, and two copies of the D-lactate dehydrogenase (D-LDH) gene from Leuconostoc mesenteroides subsp. mesenteroides strain NBRC3426 were introduced into the genome. The D-lactate production reached 61.5 g/l, the amount of glucose being transformed into D-lactic acid being 61.2% under neutralizing conditions. Additionally, the yield of free D-lactic acid was also shown to be 53.0% under non-neutralizing conditions. It was confirmed that D-lactic acid of extremely high optical purity of 99.9% or higher. Our finding obtained the possibility of a new approach for pure d-lactic acid production without a neutralizing process compared with other techniques involving lactic acid bacteria and transgenic Escherichia coli.     

Magnetic field analysis of a squirrel cage induction motor considering rotor skew and higher harmonics in the secondary current

This paper describes a method to analyze harmonic magnetic fields of squirrel cage induction motors considering rotor skew and higher harmonics in the secondary current. The proposed method is based on a two‐dimensional finite element method. The rotor skew structure is expressed by multiple 2D finite element mesh models, produced in suitable axial positions, and the magnetic field in each mesh model is calculated by the revised secondary current taking into account the skew effect. The secondary currents, magnetic flux densities, and electromotive forces are calculated by the proposed method. Then the differences between a skewed rotor and a nonskewed rotor are discussed. From the comparison between the calculated and the experimental results, the proposed method is shown to be appropriate and useful for quantitative estimation of harmonic components of induction motors. © 1999 Scripta Technica, Electr Eng Jpn, 129(2): 98–109, 1999