Evaluation of effective energy using radiochromic film and a step-shaped aluminum filter.

Although the half-value layer (HVL) is one of the important parameters for quality assurance (QA) and quality control (QC), constant monitoring has not been performed because measurements using an ionization chamber (IC) are time-consuming and complicated. To solve these problems, a method using radiochromic film and step-shaped aluminum (Al) filters has been developed. To this end, GAFCHROMIC EBT2 dosimetry film (GAF-EBT2), which shows only slight energy dependency errors in comparison with GAFCHROMIC XR TYPE-R (GAF-R) and other radiochromic films, has been used. The measurement X-ray tube voltages were 120, 100, and 80 kV. GAF-EBT2 was scanned using a flat-bed scanner before and after exposure. To remove the non-uniformity error caused by image acquisition of the flat-bed scanner, the scanning image of the GAF-EBT2 before exposure was subtracted after exposure. HVL was evaluated using the density attenuation ratio. The effective energies obtained using HVLs of GAF-EBT2, GAF-R, and an IC dosimeter were compared. Effective energies with X-ray tube voltages of 120, 100, and 80 kV using GAF-EBT2 were 40.6, 36.0, and 32.9 keV, respectively. The difference ratios of the effective energies using GAF-EBT2 and the IC were 5.0%, 0.9%, and 2.7%, respectively. GAF-EBT2 and GAF-R proved to be capable of measuring effective energy with comparable precision. However, in HVL measurements of devices operating in the high-energy range (X-ray CT, radiotherapy machines, and so on), GAF-EBT2 was found to offer higher measurement precision than GAF-R, because it shows only a slight energy dependency.

Organization and structure of NADH-dependent glutamate synthase gene from rice plants.

Genomic clones for NADH-dependent glutamate synthase (NADH-GOGAT; EC 1.4.1.14) were obtained from a genomic library of rice (Oryza sativa L. cv. Sasanishki). A genomic clone (lambdaOS42, 14 kb) covered an entire structural gene and a 3.7 kb 5'-upstream region from the first methionine. Another clone (lambdaOS23, 14 kb) contained a 2.8 kb 3'-downstream region from the stop codon. A 7047 bp long clone (lambdaOSR51) consisting of full length cDNA for NADH-GOGAT was isolated from a cDNA library prepared using mRNA from roots of rice seedlings treated with 1 mM NH4Cl for 12 h. The presumed transcribed region (11.7 kb) consisted of 23 exons separated by 22 introns. Rice NADH-GOGAT is synthesized as a 2166 amino acid protein with a molecular mass of 236.7 kDa that includes a 99 amino acid presequence. DNA gel blot analysis suggested that NADH-GOGAT occurred as a single gene in rice. Primer extension experiments map the transcription start of NADH-GOGAT to identical positions. The 3. 7 kb 5'-upstream region was able to transiently express a reporter gene in cultured rice cells. Putative motifs related to the regulation of NADH-GOGAT gene expression were looked for within the 5'-upstream region by database.

Suppression of G1 arrest and enhancement of G2 arrest by inhibitors of poly(ADP-ribose) polymerase: possible involvement of poly(ADP-ribosyl)ation in cell cycle arrest following gamma-irradiation.

Low-dose gamma-irradiation of mouse embryonic fibroblast C3D2F1 3T3-a cells caused G1 arrest along with G2 arrest and inhibition of replicative DNA synthesis. When the cells were cultured in the presence of inhibitors of poly(ADP-ribose) polymerase [EC 2.4.2.30], such as 3-aminobenzamide, benzamide and luminol, G1 arrest of C3D2F1 3T3-a cells was suppressed and enhancement of G2 arrest was observed. In contrast, 3-aminobenzoic acid, a non-inhibitory analog of 3-aminobenzamide, did not suppress G1 arrest following gamma-irradiation. These results suggest that the poly(ADP-ribosyl)ation reaction is critical for the pathway of G1 arrest and is also involved in the pathway of G2 arrest.

[Clinico-statistical observation of patients referred from our hospital at the Department of Oral Surgery].

The patients referred from our hospital at the Department of Oral Surgery, University of Tokyo, during the two years from January 1990 to December 1991 were analyzed statistically. The results were as follows: 1. Our subjects were 1,152 patients (24.2% of first-time patients), 540 males and 612 females. 2. Concerning age distribution, the majority was in their forties, fifties and sixties. 3. More patients were from internal medicine, ENT clinic, plastic surgery and cardiothoracic surgery. 4. On the number of patients categorized by disease at other departments, the largest number was cardiovascular disease. 5. On the number of patients categorized by disease at our department, the majority were dental diseases (dental caries, marginal periodontitis and missing teeth).

[Clinico-statistical observation of emergency patients at the Department of Oral Surgery].

Emergency patients at the Department of Oral Surgery, University of Tokyo, during the three years from January 1990 to December 1992 were analyzed statistically. The results were as follows: 1. The total number of emergency patients was 209 and tended to increase with the advance in years. 2. There were a few more males than females and most of the patients ages were in the twenties. 3. The disease causes were dental caries or periodontal disease in 95 (45.5%), trauma in 58 (27.8%), and inflammation in 32 patients (15.3%). 4. It is clear that a system of oral emergency treatment is necessary.

Non-covalent interaction between poly(ADP-ribose) and cellular proteins: an application of a poly(ADP-ribose)-western blotting method to detect poly(ADP-ribose) binding on protein-blotted filter.

We describe a sensitive method for the detection of interactions between poly(ADP-ribose) and proteins. Proteins were blotted onto nitrocellulose filters and incubated with 32P-labeled poly(ADP-ribose). Purified core histones and poly(ADP-ribose) polymerase were found to bind poly(ADP-ribose) polymer. Blots of HeLa cell protein extracts revealed a 48 kDa protein and several others of smaller than 35 kDa likewise bound the polymers even at high salt concentrations. Those proteins, along with a 69 kDa protein, also showed resistance to competitor DNA. Polymer binding of aforesaid HeLa extract proteins was restricted to polymers above 20 residues in length. Thus poly(ADP-ribose)-protein affinities were polymer-length dependent.

[Questionnaire about dental health in new university students].

A questionnaire about dental health was given to 6846 new students in the University of Tokyo. The results were as follows: 1. 5.3% of students had experienced periodontal diseases. The percentage of students with gingival bleeding was 20.7%. 2. Most of the students brushed their teeth 3 minutes at a time, 2 times a day. 3. 11.5% of the students had experienced orthodontic treatments. The percentage of female students was significantly higher than the percentage of male students. 4. 0.9% of the students had experienced TMJ disorders. TMJ symptoms were noted in 9.7%. 5. More than 90% of the students usually chewed on both sides of the mouth.

Effects of serine protease inhibitor FOY-305 and heparin on the growth of squamous cell carcinoma.

Effects of serine proteinase inhibitor FOY-305 and heparin on autochthonous skin carcinoma were examined using ddY female mice with single tumor induced by methylcholanthrene. FOY-305 given intraperitoneally for 9 consecutive weeks inhibited the growth of the pre-existing dermal tumors. Heparin alone was equally therapeutically effective. However, heparin induced severe mucocutaneous bleeding of the gastrointestinal mucosa. In contrast, the combined administration of FOY-305 and heparin suppressed tumor growth without any visible side effects. There was a significant increase in well differentiated cancer cells in mice treated with FOY-305 and heparin in combination, suggesting that co-administration of FOY-305 and heparin may be useful for the treatment of squamous cell carcinoma.

A new, rolled-sponge technique for transoral exposure of C1 and C2.

Instead of the general use of a catheter attached to the uvula or of catheters passed through the nasal cavity to the mouth for elevation of soft palate, the authors describe a new technique utilizing two rolled sponges producing maximum elevation of soft palate and good perioral cosmetic results for transoral exposure of C1 and C2.

[Clinical and pharmacokinetics studies of ceftriaxone upon 2g once daily administration in respiratory tract infections].

Clinical studies on ceftriaxone (CTRX) were conducted with 2 g once daily administration to respiratory tract infections. In addition, CTRX concentrations in serum, sputum and urine were determined. The results obtained are summarized as follows: 1. Clinical responses to CTRX in a total of 29 cases with respiratory tract infections were excellent in 7 cases, good in 13, fair in 8 and poor in 1 with a response rate of 69.0%. 2. CTRX concentrations in serum, sputum and urine (total and free body) were determined in 3 cases after intravenous drip infusion of 2g CTRX. Peak levels in sputum were 2.6 to 7.8 micrograms/ml, and CTRX maintained high sputum levels for 12 to 24 hours after administration.

[An operated case of Mycobacterium fortuitum infection with hemoptysis].

An operated case of M. fortuitum infection on the bronchiectatic lung was presented. A 68-year-old female had had hemoptysis due to bronchiectasis since she was 44 years of age. She had a history of pulmonary tuberculosis at the age of 58 and treated by anti-tuberculosis drugs for a year. She was referred to the National Sanatorium Hiroshima Hospital in March 1986 for surgical treatment, when M. fortuitum infection was found. Lobectomy of the right middle lobe, right S6 Segmentectomy and partial resection of right S2 were performed on December 1st 1986. After the operation, hemoptysis disappeared but M. fortuitum was still found in sputum. Chest X-ray examination revealed some new abnormal shadows. When radical surgical treatment for secondary M. fortuitum pulmonary infection is considered careful attention should be given to its indications including the extent of resection and the predicted post-operative pulmonary function.

Comparison of the radiosensitivity of interleukin-2 production between species, between tissues, and between young and old individuals.

The radiosensitivity of interleukin-2 (IL-2) production was assessed of (a) peripheral blood mononuclear cells (PBMC) of young humans, dogs, and mice (C57BL/6); (b) PBMC and splenic cells of young mice; and (c) PBMC of young and old humans and the splenic cells of young and old mice. The results indicate that (a) large differences in radiosensitivity exist between the PBMC of humans, dogs, and mice (e.g., the radiation doses which resulted in 37% remaining IL-2 activity (D37) of human, dog, and mouse PBMC were 3771, greater than 10,000, and 1398 rads, respectively); (b) only a small difference exists between the PBMC and splenic cells of mice; and (c) no difference exists between the PBMC of young and old humans and between splenic cells of young and old mice. Topological abnormalities, as judged by scanning electron microscopic analysis, could not be detected in dog PBMC after their exposure to 1800 rads, but could be detected in mouse PBMC after their exposure to 400 rads.

Differential effects of age on mitotically active and inactive bone marrow stem cells and splenic T cells in mice.

Young and old BALB/c mice and thymectomized young mice were subjected to continuous exposure of 6-thioguanine (6-TG), and the numbers of their bone marrow spleen colony-forming units (CFU-S) and in vitro culture colony-forming units (CFU-C) and the number and mitogen-induced proliferative activity of their splenic T cells were determined at various time intervals. The results indicated that (a) old mice have seven times more 6-TG-resistant (6-TGr) CFU-S than young mice, (b) the mitogen-induced proliferative activity of 6-TGr T cells is comparable to that of 6-TG-sensitive (6-TGs) T cells of both young and old mice, and (c) 6-TGr CFU-S and T cells are resistant to 6-TG because they are mitotically inactive and not because they are drug-resistant mutants.

A new method to create a philtrum in secondary cleft lip repairs.

We report an additional surgical method to form a philtrum in cleft lip cases. The key point of this new method is to release the skin tension of the upper lip, thus protecting against the disappearance of the newly-made philtrum. We have obtained better results with this method, in comparison with the other methods previously reported.

The length: breadth ratio of skin flaps on the trunk: two new long narrow flaps.

Our experience of skin flaps on the trunk is reviewed. A single-pedicle flap based on the sterno-clavicular region and a bipedicled longitudinal back flap have length: breadth ratios much in excess of random pattern flaps.