The location and nucleotide sequence of the 5S rRNA gene of bunt of wheat, Tilletia caries and T. controversa.
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Biomedical subjects
Publications and source records attributed to W K Kim.
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Total genomic DNA was isolated from three cereal stem rusts, Puccinia graminis f. sp. tritici, f. sp. secalis, f. sp. avenae, and two cereal leaf rusts, P. recondita f. sp. tritici and P. coronata f. sp. avenae, and analyzed for the presence of heterogeneity in the intergenic region of the ribosomal DNA repeat unit. A 1 kb region of the repeat unit between the 26s and the 5s rRNA genes (IGR-1) was amplified by PCR and was found to be heterogeneous within each isolate and variable in size between races and species. The PCR results were confirmed by Southern blot analysis of native DNA. In an isolate of race C36(48), heterogeneity appeared to be due to variable numbers of 0.1 kb subrepeats in IGR-1. Nine wheat stem rust strains representing nine different races produced a unique pattern of heterogeneity while two different isolates of one race were identical, as were five of another. This may provide a rapid method for race identification in wheat stem rust. Heterogeneity and polymorphism in rye stem rust, oat stem rust, wheat leaf rust, and oat crown rust, was less pronounced than in wheat stem rust. In the course of this work, the 5s rRNA gene was located and its position and orientation within the ribosomal repeat unit was established.
STUDY OBJECTIVE: To determine the extent to which increasing doses of exogenous testosterone (T) administered via Silastic implants can restore spermatogenesis and fertility to rats made azoospermic by active immunization against gonadotropin-releasing hormone (GnRH). DESIGN: Male rats were made azoospermic by active immunization against GnRH. Increasing doses of exogenously administered T (via Silastic implants) were administered for 8 weeks, and testicular sperm concentration and ability to impregnate female rats were evaluated. SETTING: Reproductive Endocrinology Laboratory, Department of Obstetrics and Gynecology, University of Colorado Health Sciences Center, Denver, Colorado. ANIMALS: Sexually mature male Sprague Dawley rats (SASCO, Omaha, NE). RESULTS: Suppression of gonadotropins and azoospermia was achieved by actively immunizing rats against GnRH. Testosterone was capable of restoring quantitatively complete spermatogenesis and fertility in GnRH-immunized azoospermic rats. This relationship was dose-dependent, as evidenced by the partial restoration of spermatogenesis and fertility observed in animals replaced with smaller T Silastic implants. CONCLUSION: Gonadotropin-releasing hormone immunization and T-filled Silastic implants may provide a model to study isolated gonadotropin deficiency and for the development of a reversible male contraceptive.
Soft-tissue alterations associated with radical degloving of the overlying soft tissues during extended open reduction and rigid internal fixation of facial fractures involving 51 orbits in 36 patients were studied. In all patients, the blepharoplasty skin muscle flap incision was employed in conjunction with, as necessary, a gingivobuccal sulcus and coronary incisions. Patients were evaluated between 6 and 20 months after surgery. Physical examination and standardized photographs were used for assessment. Ectropion developed in 2 lids (4%), and 10 lids (20%) had increased scleral show. Thirteen of the 51 lids (25%) revealed lateral canthal displacement; all 13 lids underwent canthal stripping. Cheek pad displacement developed in 8 patients (22%), all of whom had complete maxillary degloving without soft-tissue resuspension. No patient had frontal nerve palsy. Depression in the temporal area was noted in all patients in whom the temporalis was mobilized. Remote incisions and soft-tissue degloving used for extended open reduction and internal fixation are associated with morbidity that can be minimized by meticulous technique and soft-tissue repositioning at closure.
An efficient algorithm detecting the presence of a fetal QRS complex is presented. The proposed fetal QRS detection method computes the averaged magnitude of the difference between the fetal ECG signal and the reference signal to detect the fetal QRS event. The detected fetal QRS complexes are exponentially averaged to generate the template signal which can track the slowly varying shape of the fetal ECG signal. As an effort to obtain improved detection performances, two approaches of normalizing the fetal ECG signal and the template are considered.
Rapid economic development resulted in urbanization of Korea, since 1960s. Seoul is the center of politics, finance, education and culture of Korea. Mostly young people have migrated to large cities, such as Seoul and Pusan. For instance, the population in Seoul city was 2.5 million in 1960 but increased to 10 million in 1990. Presently, total population of Seoul and Pusan, second largest city, composed of approximately 50% of whole national population. The economic distribution among urban people became extremely uneven creating a large gap between low and high income group. As a consequence, both under and over nutritional problems coexist. According to the national nutrition survey data, animal food, such as meat, fish and dairy products have been consumed about 6 times more, and cereal consumption was far less in higher income group. In terms of nutrients intake, 28% of total caloric intake comes from lipids and 15-17% of total caloric intake from protein. This was found in higher income group, while low income group consumed more than 80% of total caloric intake from carbohydrate. The trends of major causes of death in Korea have changed. The degenerative diseases, cerebral disorder, high blood pressure became leading cause of death in recent years. Malignant neoplasm and diabetes followed second leading cause of death in Korea. Undernutrition and nutritional insufficiencies, anemia and low growth rate continue to exist among low income group. According to the annual death rate by age group, the age between 34-54 was the highest in the world.(ABSTRACT TRUNCATED AT 250 WORDS)
The mechanism of the beneficial effect of immunotherapy for human reproductive wastage remains to be elucidated. Induction of blocking antibodies such as anti-HLA class II antibodies and anti-idiotypic antibodies was investigated as the mechanism of specific immunosuppression in pregnancy. We reported the changes in the mixed lymphocyte reaction (MLR), T-cell subsets, and generation of anti-idiotypic antibodies after immunotherapy compared to before immunotherapy. MLR was significantly (P less than 0.001) inhibited after the immunization. The mean inhibition rate was 50.2%, suggesting that MLR blocking antibodies were induced by immunotherapy. Binding of autoantibodies to alloactivated maternal lymphoblasts against the paternal lymphocytes was detected in postimmunization cases in two-color flow-cytometric experiments. This suggests that anti-idiotypic antibodies were induced by the immunotherapy. The percentage of cytotoxic T-cells was significantly decreased (P less than 0.05) and the percentage of suppressor T-cells was significantly increased (P less than 0.01) after the immunotherapy, suggesting that a cell-mediated immune response was induced by the immunotherapy.
The degree of attraction of Toxoplasma gondii to vertebrate cells varies with cell type and cell phase. Human promyelocytic leukemia cells, HL-60, were synchronized by double thymidine block method and co-cultured with Toxoplasma for 1 hr at each cell stage to investigate the cell cycle specific susceptibility of parasites to host cells. For 30 hr the average number of Toxoplasma that invaded was a little changed except at 3 hr from G1/S phase boundary which concurred with the peak point of DNA synthesis. At 3 hr which is a relatively short interval compared to whole S phase, modification of cells by parasitic invasion was most remarkable. The number of Toxoplasma that penetrated was increased to more than six times. The shape of the cells became sludgy and almost indiscernible by strong accessibility of parasites only for an hour of mid-S phase. The same fluctuation was also observed at the second peak of S phase but weakly. This suggests that there be surface molecules concerning with the attachment of Toxoplasma to the host cells, which is expressed at special point of S phase. Further studies on the specific protein or similar molecules related could be carried out using synchronized HL-60 cells.
Software which can be used to simulate stereotactic surgery on a personal computer was developed. Using the modified Todd-Wells frame coordinates, it can reconstruct a three-dimensional image of the brain structure and simulate the target trajectories before the operation. Also, it can calculate the volume of the target region and the distance between the target and certain points in arbitrary trajectory angles. Its optional mode can be used for simulation of conventional brain surgery for previewing deep-seated brain lesions in the operating position.
To assess the role of cAMP on the growth and proliferation of Toxoplasma in HL-60 cells we tested the effect of exogenous cAMP and cAMP analogues to the co-culture system of Toxoplasma and HL-60 cells. cAMP, dbcAMP, and br-cAMP stimulated the growth of Toxoplasma at a specific concentration, i.e., 10(0) mM, 10(0) mM, and 10(-1) mM, respectively. There were differences in growth induction kinetics and in the rate of promotion. These results were further verified by treating the co-culture with adenylate cyclase activator, pNHppG, cAMP phosphodiesterase activators, imidazole and A23187, and cAMP phosphodiesterase inhibitors, IBMX, compound 48/80, and theophylline, separately. When the cytosolic cAMP levels increased by the reagents mentioned above, Toxoplasma in the cytoplasm of HL-60 cells stimulated to proliferate more rapidly with concentration-dependent modes compared to the control, and vice versa. It is suggested that some mechanisms are activated by the high levels of cAMP in the cytoplasm, which result in the stimulation of Toxoplasma proliferation.
Comparison of the nucleotide sequence of the upstream c-myb exon UE3 with the sequences of a thymus c-myb cDNA and of a B-lymphoma c-myb cDNA suggested the existence of T- and B-cell-specific heterogeneity in the 5'-terminal region of the c-myb coding sequence. This possibility was investigated with T-cell-specific and B-cell-specific DNA probes in a Northern (RNA) blot analysis of mRNAs from different hematopoietic cell types and from chicken embryo fibroblasts. The hematopoietic tissues analyzed were bone marrow, bursa of Fabricius, and thymus from 1-day-old chicks, 13-day yolk sac, and spleen from 16-day embryos. At least three different c-myb mRNA species were found to have 5'-terminal heterogeneity that was specific for either B cells, T cells, or the other hematopoietic cells and chicken embryo fibroblasts. This lineage-specific heterogeneity in the c-myb transcript was found to be expressed in the bone marrow precursors of B and T cells before they migrated to their definitive differentiation sites. S1 nuclease protection analysis of the UE3 exon, part of which appeared to be coding sequences for thymic c-myb mRNA, revealed that this exon is utilized either in its entirety or partially in a cell-lineage-specific manner by all six tissues analyzed. Also, the 5'-terminal exon(s) present in the thymus cDNA was absent in c-myb mRNAs from the other cell types analyzed.
Total 2,829 persons consisted of 1,019 general patients and 1,030 asthma-suspected patients who visited Kangnam St. Mary's Hospital and 780 general patients who visited Cheju Medical Center were examined for the antibody titers of Toxoplasma by indirect latex agglutination (ILA) test. Nineteen out of 1,019(1.86%) cases in general patients group, 11 out of 1,030(1.07%) cases in asthma patients group, and 45 out of 780(5.77%) cases in Cheju patients group showed positive ILA titers. Concerned with the age and ILA positive cases, general and asthma patients expressed more cases at thirties to sixties while Cheju patients showed high incidence at children and adolescents in addition to the above mentioned ages. Frequencies of ILA positive titers were highest in 1:32 and 1:64, and some cases showed 1:2,048 or higher titers.
Four females and a male nematode isolated from 2 patients who visited eye clinics in Seoul were identified as Thelazia callipaeda and their ultrastructures were observed by scanning electron microscopy (SEM). General features of the worms were slender and attenuated at both ends. Vaginal opening was located at 0.27 mm from the anterior end, and in front of the esophago-intestinal junction. In the body cuticle transverse striations varied characteristically through the body. The number of cuticular transverse striations was 400-650/mm at head portion, 250/mm at middle portion and 300-350/mm at tail portion. The SEM observation of the mouth part of the females showed 6 cord-like cuticular thickenings in hexagonal arrangement and an amphid was observed. A lateral line, a vaginal opening, a pair of phasmids, and an anus were identified in the body portion. A pair of papillae and 6 cord-like cuticular thickenings were on the mouth part of the male. It was difficult to observe structures at the tail of the male except wrinkle-like structures. Most of the larvae isolated from the uterus of a female worm were sheathed and thus cuticular striations were not seen. Others were un-sheathed and revealed cuticular striations. The oval membrane which encysted sheathed larvae was also observed. These are the 18th and 19th record of human thelaziasis in Korea as the literature are concerned.
The authors developed a computerized electroencephalography imaging system with an IBM PC AT. The EEG signals amplified with a 16 channel EEG machine were digitized at 51.2 Hz (512 samples per epoch). The shifted DC potential and 60Hz artificats were removed by a high pass filter and 60Hz notch filter. A window function consisting of a 10% cosine taper was obtained by weighting the points at either end of the epoch by a cosine bell. A fast Fourier transform was applied to every epoch and the power spectrum estimates were computed in 0.39 Hz steps. The activity estimates for the delta, theta, alpha and beta bands were computed by summimg adjacent values. The outline of the top-down maps was formed from a series of sagittal cuts, then 32 electrodes were placed on the map. A file was created which contained a table of weighting parameters for calculating the interpolated values for every point within the outline. Each weight was in inverse linear proportion to the distance of the pixel to the nearest four electrodes. The map was finally generated with computation of the spectral EEG in each pixel according to the weighting parameter. The functioning of this system was tested with a functional generator and a human subject.
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Sixteen proto-oncogenes which have generated retroviral oncogenes were tested for their expression in chicken leukemic cells induced by avian myeloblastosis virus (AMV) and five were found to be expressed (c-ets, c-fps, c-mht, c-myc, and c-rel). The size of the c-fps transcript (4.0 kb) was not in good agreement with the size (approximately 3.0 kb) previously reported but was uniform in the leukemic cells from 10 different chickens. The size of the other proto-oncogene transcripts appeared normal. The five expressed proto-oncogenes represent cellular genes involved in hematopoiesis. Interestingly the c-myb gene was not expressed in any of the leukemic cells despite its expression in the immature myeloid cells which are targets for AMV transformation. This could represent down regulation of c-myb by v-myb or a differentiation-related arrest of c-myb expression. The leukemic phenotype induced by v-myb may therefore become expressed at a stage of myeloid differentiation when c-myb expression is repressed.
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Signal-to-noise ratio and image resolution in an ultrasonic imaging system are compared for four kinds of excitation signals, namely, a single pulse, an unmodulated pseudo-random code, a modulated pseudo-random code and a deconvolved pseudo-random code, all for a given length and amplitude. It was predicted and found from measurements that the best S/N and resolution are obtainable with the deconvolved pseudo-random code.