Purification and kinetics of mouse liver fructose 6-phosphate, 2-kinase

The mouse liver fructose 6-phosphate, 2-kinase was purified by ultracentrifugation, polyethylene glycol precipitation, and subsequently by chromatography on DEAE-Sephadex, Blue-Sepharose and phasphocellulose columns. Gel filtration and SDS polyacrylamide electrophoresis showed that the enzyme has a molecular weight of 110,000 with two identical subunits. Mg2+ is essential for its activity. The activation of the enzyme by Mg2+ showed a positive cooperativity. The substrate saturation curve for fructose 6-phosphate was sigmoidal and for ATP was hyperbolic. The Km's for ATP increased with decrease in concentrations of fructose 6-phosphate indicating that the sequence for the substrates binding was in an ordered mechanism with respect to fructose 6-phosphate prior to ATP. An ionizable residue at the active site with pKa 9.5 was essential for the ATP binding and the pKa shifted to 9.8 after the binding of ATP.

[Familial gastro-intestinal adenomatosis]

Twenty-seven cases of familial gastro-intestinal adenomatosis are reported. There was no difference in pathology between 11 cases with familial involvement and 16 cases without. Juvenile, lymphoid as well as hyperplastic polyps coexisting with adenomas were found in a few cases. The risk of developing cancer in adenomas of 0.5 cm, 0.5-0.9 cm, 1.0-1.9 cm and 2.0 cm were 0%, 1.1%, 9% and 75%, respectively. Size seems to be the most critical and reliable indicator of malignant transformation. Proctectomy and colectomy of distal colon combined with removal of the adenomas equal to or larger than 1.0 cm through endoscope might be the better surgical intervention to avoid carcinomatous change. The term "familial polyposis coli" is suggested to be designated as "familial gastro-intestinal adenomatosis".

Mitochondrial DNA polymorphism in Chinese

Human mitochondrial DNA (mtDNA) restriction endonuclease fragment patterns were analyzed using placenta DNA isolated from 273 individuals representing four different nationalities, the Han, the Uygur, the Kazakh and the Hui populations. Thirty-eight fragment patterns (morphs) were observed with the enzyme ApaI, BamHI, EcoRI, HindIII, HinfI, HhaI, HapII, KpnI, Mbol, PstI, PvuII, SacI, ScaL and XhoI. Fourteen new morphs, including some only existing in individual racial and national populations were observed, which indicates that there is a significant difference in the distribution of mtDNA morphs among various national and racial populations. By comparison with the mtDNA sequences in primate species, some mtDNA ancestral morphs were found to be retained in Oriental population today. This result provided indirect evidence that Asia may be one of the human original sources. Genetic distances among four national populations computed and employed in construction of an average linkage tree suggested that the Uygur and the Kazakh populations combined to form a branch at first, then the Han and the Hui came together to form another one, and at last, these two branches converged into a stem. Again, it was found that the internal variation within the Uygur and the Kazakh populations was greater than that within the Han and the Hui populations. These results showed a relationship among the four different national populations in China based on the molecular level.

Propagation characteristics of guided waves in stratified metallic optical waveguides

An eigenvalue equation is derived for stratified metallic optical slab waveguides with any number of layers. The equation is solved using the numerical zoom analysis (NZA) method. The analysis is applied to various metallic optical slabs and the propagation characteristics of the guided waves are determined, which may be useful for optimizing the design parameters. It is found possible, with proper optimization, to design a polarizer having hundreds of decibels of extinction ratio at. the cost of a fraction of a decibel of insertion loss. Examples of optimizations with respect to wavelength, relative refractive indices, core/clad geometries, etc. are demonstrated for slabs with single or double metal layers. Guidelines for determining the metal film thickness have been formulated and tabulated for many useful metals.

Altered low density lipoprotein receptor regulation is associated with cholesteryl ester accumulation in Simian virus 40 transformed rodent fibroblast cell lines

Several SV40 transformed REF52 cell lines were found to accumulate 5 to 10 times more cholesteryl esters compared to their parent line REF52 when cultured in 10% serum. Under this culture condition, the cholesteryl ester to phospholipid ratio was 0.4:1 and 2.0:1 to 3.8:1 for normal and SV40 transformed cells, respectively. The mechanism underlying cholesteryl ester accumulation in SV40 transformed lines was investigated. We found that 1) the rate of the de novo cholesterol and cholesteryl ester synthesis was roughly equal in normal and transformed derivatives; 2) the accumulation of cholesteryl esters in the transformants would not occur when cultured in lipoprotein-deficient medium and reappeared upon their return to low density lipoprotein-containing medium; 3) the transformants expressed twice as many low density lipoprotein receptors and were less sensitive to LDL-induced receptor down regulation compared to their nontransformed counterparts. The results indicate that SV40 transformed lines exhibited an accelerated lipid uptake from the culture medium due to an altered regulation of low density lipoprotein receptor activity.

[Application of monoclonal antibody OC 125 in gynecological oncology]

This study was undertaken to determine whether the measurement of CA125 could effect an early diagnosis and a method for monitoring the course of gynecologic tumors. CA 125 in serum of 195 patients, including 15 apparently healthy women; 39 benign gynecologic tumors; 2 borderline ovarian tumors; 139 malignancies were measured by CENTOCOR cancer antigen 125 kits. Diagnosis of all patients was confirmed by pathology. None of the healthy women; 10% of benign tumors; 78% of epithelial ovarian cancers; 31% of endometrial adenocarcinomas and one out of five adenocarcinoma of uterine cervix had CA 125 level over 65 U/ml. In addition, 23 cases of ovarian cancer were monitored serially up to 9 months. In more than 80% of these patients, CA 125 levels were correlated with the regression or progression of the disease. The significance of this assay for early diagnosis and monitoring the course of ovarian cancer is discussed. It is considered that CA 125 is a promising and useful antigenic marker for monitoring the course of ovarian cancers.

Response of spinach and kidney bean plants to nitrogen dioxide

Different responses of spinach and kidney bean plants to various concentrations of NO(2) in the light and in the dark were shown. Spinach is more resistant than NO(2) than kidney bean. It is not only due to its greater tolerance to NO(2)(-) accumulated in leaves, but also to its stronger ability to metabolize NO(2)(-). The injury of spinach induced by the exposure to high concentration NO(2) in the light was not caused by the accumulation of NO(2)(-), but concerned the large amount of accumulated NH(3). The primary causes of NH(3) accumulation were that the activity of nitrite reductase was not affected by the fumigation on the one hand, and the activities of glutamine synthetase and glutamate synthase were inhibited on the other.

Thalassemia in the Silk Road region of China

This paper summarizes data obtained during a screening program involving 11,563 persons from the Silk Road region in China. The mean incidence of thalassemia is 1.62% with an increase from east to west. The incidence in the Hui population (3.01%) is higher than in Kazaks (2.92%), and in Uygur (2.22%). The Han population also has a higher incidence (0.98%) than seen for other regions in Northern China. The thalassemias observed are classified into seven groups; beta-thalassemia accounts for 89.48% of the total, and alpha-thalassemia for 10.52%.

[Treatment of 63 advanced ovarian carcinomas]

62 patients with advanced epithelial ovarian adenocarcinoma (37 stage III, 4 stage IV and 22 recurrent lesions) were treated in our hospital from 1977 to 1981, 38 patients underwent surgery. 25 with inoperable tumor initially received preoperative chemotherapy (VCF protocol: vincristine + cyclophosphamide + fluorouracil chiefly) followed by surgery. The response rate of chemotherapy was 48%. Apart from 1 progressive tumor during chemotherapy, 24/25 were explored. There were 10/24 with residual tumor less than 2 cm in diameter, giving a resection rate of 41.7% as compared with the resection rate of 42.1% (16/38) in the operation group. It is shown that the preoperative chemotherapy improves the resection rate. 44 patients received postoperative chemotherapy and 12, radiotherapy combined with chemotherapy or radiotherapy only. The overall 2.3 and 5 year survival rates of these 63 patients were 39.7%, 31.7% and 23.8%. The 2 and 3 year survivals were 41.9% and 32.3% in 31 patients with postoperative chemotherapy using VCF protocol. The results indicate that VCF protocol is effective for advanced epithelial ovarian cancer, especially patients with residual tumor less than 2 cm in size. Chemotherapy with more than 3 courses has better effect.

Stability properties of oxymyoglobin from chicken gizzard smooth muscle

1. Oxymyoglobin (MbO2) was isolated directly from the smooth muscle of chicken gizzard and was examined for its spectral and stability properties. 2. When compared with sperm whale MbO2 as a reference, chicken gizzard MbO2 was found to be much more susceptible to autoxidation. Its pH-dependence was therefore analyzed in terms of an "acid-catalyzed three-state model". 3. The complete amino acid sequence of the myoglobin was also determined. Its hydropathy profile revealed that the region corresponding to the distal side of the heme iron appears to be less hydrophobic.

Cytogenetic monitoring of petrochemical workers

The frequencies of chromosomal aberrations and sister-chromatid exchanges (SCEs) in the peripheral blood lymphocytes of 360 persons, 180 workers in a petrochemical corporation and 180 appropriate controls, were studied. A significant increase in chromosomal aberrations and SCEs, compared to the control group, was observed in two sewage-treatment workshop workers; however, there were no significant differences between petrochemical workers from four workshops and a control group.

Cilia and ciliogenesis in endometrial adenocarcinomas. An ultrastructural analysis

Cilia in neoplastic cells were observed by electron microscopy in specimens from five of six consecutive patients with endometrial adenocarcinoma. Most cilia showed a range of defects, from misalignment and displacement of individual doublets to the absence of up to three peripheral doublets, the pattern varying from 9+2 to 6+2; the central pair of microtubules also was frequently missing. Single peripheral microtubules and displacement of the dynein arms were also observed. The high proportion of cilial defects in neoplastic cells (72%) compared with those in normal endometrium (26%), together with a broader spectrum of cilial abnormalities, suggests that the neoplastic state increases the number and range of cilial lesions.

Hemoglobinopathies in Xinjiang

The present report summarizes the results of a search for hemoglobinopathies in 142,171 persons in Xinjiang, the results of structural analyses of abnormal hemoglobins in 134 families, and the incidence and distribution of abnormal hemoglobins and the thalassemias in eight ethnic groups or nationalities.