Search PubMed⌕ Search

Biomedical subjects

J Jung

Publications and source records attributed to J Jung.

At least 127 records · Page 7Linked to original sources
PubMed1994

Epithelial tumours induced by a herpesvirus oncogene in transgenic mice.

To investigate the role of herpesviral genes in tumourigenesis, transgenic mice were generated expressing STP-C, a transformation associated protein of the lymphoma inducing herpesvirus saimiri. Epithelial tumours developed in the salivary gland, pancreas, thymus and liver of transgenic mice within the first weeks of life. Thus, the target cells for tumour formation in the transgenic mice were surprisingly different from those of the herpesvirus from which the oncogene was derived. Our results identify STP-C as a herpesvirus oncogene sufficient for tumour induction without the cooperation of other viral gene products. Furthermore, the results demonstrate pleiotropic transforming capabilities of the STP-C oncogene and suggest that the specificity of lymphoma induction by the virus is determined by factors other than the oncogene itself.

Animals↗
PubMed1993

18q-mosaicism associated with Rett syndrome phenotype.

Rett syndrome consists of a characteristic progressive encephalopathy in females. The cause of this syndrome is unknown. We present a patient with 18q-mosaicism who, along with the characteristics of this autosomal deletion, also fulfills the clinical criteria for Rett syndrome. This may demonstrate heterogeneity within this as yet clinically defined syndrome. A thorough chromosomal analysis should be performed in suspected cases of Rett syndrome.

Adult↗
PubMed1993

Biodegradation of phenol: a comparative study with and without applying magnetic fields.

The objective of this work was to study the effect of magnetic fields on the rate of phenol biodegradation using immobilized activated sludge. A recirculation flow bioreactor employing immobilized bacterial beads was used with phenol as the substrate to study the biodegradation process. This study was conducted by applying separately the north pole and the south pole magnetic fields to the bioreactor. Rate of dissolved oxygen consumption, phenol concentration and extracellular protein concentration were the parameters monitored during the process. It was observed that by applying a magnetic south pole to the process, biodegradation in the form of biological oxidation was enhanced. A 30% increase in biodegradation rate was obtained by applying a magnetic south pole of strength of 0.45 Tesla to the bioreactor with immobilized microbial beads as compared to the control. Magnetic north pole irradiation inhibited this type of biooxidation. This process has potential for biological treatment of organic wastes.

Bacteria↗
PubMed1993

The relationship of worrying, coping, and symptoms among college men and women.

College students maintained a daily log of their worrying for 7 consecutive days, with three different subgroups starting on different days of the week. Patterns of the type and amount of worrying did not vary systematically over successive days. Multiple regression analyses showed a direct relationship between worrying level and amount of psychological symptoms, as measured by both the diary method and a single item self-rating. Avoidance coping was related to higher levels of physical and psychological symptoms, whereas problem solving was associated with fewer psychological symptoms for females. Men and women, for the most part, had similar relationships among the variables.

Adaptation, Psychological↗
PubMed1993

The efficacy of hydrophilic contact lens cleaning systems in removing protein deposits.

New, never-worn, individual hydrophilic contact lenses were incubated in an artificial tear solution (containing lysozyme, albumin, lactoferrin, and glycoprotein) for 24 hours at 37 degrees C with constant stirring. These lenses were then cleaned following the manufacturer's instructions with one of six commercial cleaning systems: AOSEPT, CONSEPT, Oxysept, ReNu, Opti-Free and thermal disinfection in conjunction with the Allergan Enzymatic Contact Lens Cleaner. The protein remaining on each lens after cleaning was removed and then quantified by the Bio-Rad Protein Assay. High resolution gel electrophoresis was used to assess the individual protein profile patterns. We found that only one-third to one-half of the protein deposited on a lens is removed by the above cleaning systems. Of the proteins in the artificial tear solution only lysozyme is removed by cleaning, while lactoferrin, albumin, and glycoprotein tend to remain on the lens. Since many of the complications experienced by contact lens wearers are thought to be related to protein deposits on their lenses, our results suggest the need for more effective contact lens cleaning solutions.

Albumins↗
PubMed1992

Iron-sulfur centers as endogenous blue light sensitizers in cells: a study with an artificial non-heme iron protein.

The possible involvement of Fe-S clusters in photodynamic reactions as endogenous sensitizing chromophores in cells has been investigated, by using an artificial non-heme iron protein (ANHIP) derived from bovine serum albumin and ferredoxins isolated from spinach and a red marine algae. Ferredoxins and ANHIP, when exposed to visible light, generate singlet oxygen, as measured by the imidazole plus RNO method. Irradiation with intense blue light of the ANHIP-entrapped liposomes caused severe membrane-damage such as liposomal lysis and lipid peroxidation. In the presence of ANHIP, isocitrate dehydrogenase and fructose-1,6-diphosphatase were photoinactivated by blue light. However, all of these photosensitized reactions were significantly suppressed by a singlet oxygen (1O2) quencher, azide, but enhanced by a medium containing deuterium oxide. Further, the Fe-S proteins with the prosthetic groups destroyed did not initiate the blue light-induced reactions. In addition, the action spectrum for 1O2 generation from ANHIP was very similar to the visible absorption spectrum of Fe-S centers. The results obtained in this investigation appear consistent with the suggestion that Fe-S centers are involved in photosensitization in cells via a singlet oxygen mechanism.

Animals↗
PubMed1992

Malignant melanoma in 20-MHz B scan sonography.

In order to assess the value of 20-MHz sonography in the pre-operative diagnosis of malignant melanomas, 54 melanomas were examined. The pre-operative ultrasound scans were compared with corresponding histological sections from the excised tumours. A computer-aided measurement of the tumour thickness (sonometry) and the internal echo density (densitometry) was performed in the ultrasound scans. The melanomas appeared as largely echolucent zones. There was a significant correlation between the tumour thickness measured in the ultrasound scan and those measured in the histological sections (r = 0.938, p less than 0.001). As a rule the tumour thickness determined by sonometry were greater than the histometrically determined values. Subtumoral inflammatory infiltrate and other hypo-echoic structures in the region of the tumour are possible causes of the discrepancies. Some of those hypo-echoic structures can be identified and disregarded in B scan measurement. Even if a definite differential diagnosis is not possible on the basis of the ultrasound scan alone, 20-MHz sonography provides additional information which can be of use in surgical planning.

Adolescent↗
PubMed1991

PCR-based typing of DNA extracted from cigarette butts.

Limited genetic marker information can be obtained from saliva by typing by conventional serological means. Thus, the application of PCR-based DNA typing methods was investigated as a potential approach for typing genetic markers in saliva. DNA was isolated from 200 cigarettes smoked by 10 different individuals (20 cigarettes per individual) and from 3 cigarette butts recovered from 2 crime scenes (adjudicated cases) using a Chelex 100 extraction procedure. The amount of recovered human DNA was quantified by slot-blot analysis and ranged from approximately less than 2-160 ng DNA per cigarette butt for the 200 samples, and 8 ng, 50 ng, and 100 ng for the cigarette butts from the adjudicated cases. The DNA was successfully amplified by the polymerase chain reaction (PCR) for the HLA-DQ alpha locus (99 out of 100 samples) as well as for the variable number of tandem repeat (VNTR) locus D1S80 (99 out of 100 samples). Amplification and typing of DNA was successful on all samples recovered from the crime scenes. The results suggest that PCR-based typing of DNA offers a potential method for genetically characterizing traces of saliva on cigarette butts.

DNA↗
PubMed1990

Quantification of transformation efficiency using a new method for clonal growth and selection of axenic Dictyostelium cells.

A new method for clonal growth of Dictyostelium axenic amoebae has been developed. Cells are plated in growth medium containing 1% ultra-low gelling temperature agarose. Cells grow normally in the agarose and form colonies up to several millimeters in diameter. When the colonies have grown to a sufficient size, they begin multicellular development. Pseudoplasmodia are formed, migrate to the surface of the agar, and then undergo fruiting body formation. Cells can be removed from the soft agarose colonies with a toothpick or by picking spores from the fruiting bodies. This method should be useful for drug, auxotrophic, and temperature selections where clonal maintenance of axenic colonies is important. This method has been used in combination with a selection for resistance to G418 to isolate independent colonies following DNA-mediated transformation. Several parameters in the calcium phosphate and electroporation transformation protocols have been optimized and the transformation frequency quantified. Independent transformed colonies are obtained at a frequency of 1 in 10(4) to 1 in 10(5) cells when integrating plasmids are introduced using calcium phosphate coprecipitation. The frequency is about tenfold higher when extrachromosomal shuttle vectors are introduced into cells.

Agar↗