Agrobacterium tumefaciens induces cancerous growths called crown galls at wound sites on dicotyledonous plants. A large plasmid called T1 plasmid is responsible for virulence. Upon tumor induction, part of the plasmid, termed T-DNA, becomes integrated into plant genome and its genetic sequences are expressed. These properties allow T1 plasmids to be used as gene vectors in plants. Several in vitro methods for the transfer of T1 plasmid into plant cell have been developed. One of them is the treatment of bacterial spheroplasts and plant protoplasts mixture with polyethylene glycol that is generally used as fusogen in cell-to-cell fusion. Several workers investigated the interaction of bacterial spheroplasts with plant protoplasts in the presence of polyethylene glycol and suggested that the interaction is not fusion but endocytosis. In this report we observed the interaction of Agrobacterium tumefaciens spheroplasts with Nicotiana tabacum protoplasts by electron microscope. Agrobacterium tumefaciens spheroplasts with Nicotiana tabacum protoplasts were prepared and mixed in the presence of polyethylene glycol and high pH-high Ca²⁺ buffer. Then the interaction of the spheroplasts with the protoplasts was examined by transmission electron microscope. After the treatment of polyethylene glycol the spheroplasts adhered to the surface of the protoplasts and then they were engulfed by the protoplasts. After the high pH-high Ca²⁺ buffer treatment the engulfed spheroplasts lost their cell integrity. No fusion process was observed. Thus all these observation suggest that the introduction process of Agrobacterium tumefaciens spheroplasts into Nicotiana tabacum protoplasts with the aid of polyethylene glycol is endocytosis.
Agrobacterium tumefaciens* ; Agrobacterium* ; Endocytosis ; Genome, Plant ; In Vitro Techniques ; Plant Cells ; Plant Tumors ; Plants ; Plasmids ; Polyethylene Glycols ; Protoplasts* ; Spheroplasts* ; Tobacco* ; Virulence ; Wounds and Injuries

No abstract available.

Transient osteoporosis of the hip is a self-limited condition of uncertain etiology and pathogenesis that affects young and middle aged adults. Even its clinical features are similar to the features of osteonecrosis the prognosis and clinical end result are quite different. So differential diagnosis between the two is very important. We present a case of transient osteoporosis of the hip in middle aged man, which was completely reeovered after conservative treatment.
Adult ; Diagnosis, Differential ; Hip ; Humans ; Middle Aged ; Osteonecrosis ; Osteoporosis ; Prognosis

No abstract available.
Child* ; Glomerulonephritis* ; Humans

No abstract available.
Child* ; Heart Septal Defects, Ventricular* ; Humans

No abstract available.
Catheters* ; Heart Defects, Congenital*

The cumulative incidence of breast cancer in Korea is low, being about one-fifth of that in the United States. This low incidence has been mainly explained by environmental factors, and recently, however, racial variations in the disease-causing genes should also be considered. The BRCA1 is one of the common genes involved in early-onset breast cancer and/or ovarian cancer in the United States and Northern Europe. However, the involvement of BRCA1 in Korean'breast cancer patients are still unclear. We performed germline mutation screening of the BRCA1 gene by DNA single strand conformation polymorphism (SSCP) analysis. We examined 27 breast cancer patients who were diagnosed less than 35 years by age including two cases with family history of breast cancer. Our study showed no germline mutation at the exons 2, 11 and 20, which were known as the supreme susceptible regions of BRCA1 mutations. Even though our cases did not fulfilled the criteria of familial breast/ovarian cancer, the proprotion of families who inherit the mutated BRCA1 allele seems to be very small and might be negligible among Korean population. Therefore, it is considered that the BRCA1 itself cannot be a major susceptibility gene and the contributions of other genes might be important for the breast cancer.
Alleles ; Breast Neoplasms* ; Breast* ; DNA ; Europe ; Exons ; Genes, BRCA1 ; Germ-Line Mutation* ; Humans ; Incidence ; Korea ; Mass Screening ; Ovarian Neoplasms ; United States

No abstract available.
Child* ; Humans ; Kidney Failure, Chronic*

Double outlet right ventricle, a complex of congenital cardiac anomalies in which both great arteries arise wholly or in large part from the morphologic right ventricle presents diverse clinical manifestations according to the morphological characteristics. Eighty cases with DORV were diagnosed and operated at Yonsei Cardiovascular Center from 1988 to 1992. The analysis of the morphological characteristics of this anomaly and comparative study of operative methods and mortality according to the morphological classification led to the following results: 1) The location of VSD varied to be subaortic in 40 cases, subpulmonic in 15, doubly committed in 6 and noncommitted in 19 cases. The great arteries were interrelated in D-malposition in 43 cases and L-malposition in 18 and 26 cases among above mentioned 61 cases revealed the side-by-side relationship. Ten of the cases showed normal position and the rest 9, A-malposition. 2) Pulmonary stenosis was found in 60 cases, and when associated with subpulmonic VSD, occurring less frequently. PDA and ASD secundum were associated in successional order and only 3 cases were verified to carry aortic arch anomalies such as coarctation and interruption, all with subpulmonic VSD. 3) Intraventricular tunnel repair was possible in every case associated with subaortic VSD and the postoperative prognosis was excellent. In comparison, most of the cases associated with other types of VSD in which only palliative surgery or various types of intraventricular repair were performed, the general outcome was poor. But total cavopulmonary connection, one of the physiological corrective methods, showing a better postoperative prognosis is being carefully considered for its broad adoptation in future. In conclusion, double outlet right ventricle, a pathophysiological complex of various anomalies, should be thoroughly evaluated for the morphological characteristics to decide the most appropriate types of operation and for consequent improvement of prognosis.
Aorta, Thoracic ; Arteries ; Classification ; Double Outlet Right Ventricle* ; Heart Ventricles ; Mortality ; Palliative Care ; Prognosis ; Pulmonary Valve Stenosis

To evaluate the diagnostic accuracy of two-dimensional echocardiogrphy(2-D echo) in ventricular septal defect, location and size of the defects, estimated right ventricular systolic pressure and associated cardiac anomaly were compared to the operative findings in 139 children operated for correction of ventricular septal defect at Severance Hospital from Jan. 1983 to June 1987. In addition, postoperative complications and mortality cases were anlysed. The following results were obtained; 1) Perimembranous defects were 82 cases(66.1%), subarterial infundibular defects 33 cases(26.6%), and muscular defect was found in only 1 case(0.8%). The accuracy of 2-D echo in localizing the defects was 84.2%. 2) In 79.2% of the patients, the defects were moderate to large in size, and actual size measured at operation was larger than that obtained by echocardography in general. 3) The estimated right ventricular systolic pressure was correlated(r=0.650) with that measured at the operating field. 4) Combined cardiac anomalies were patent ductus arteriosus(22 cases), atrial septal defect(3 cases), valvular pulmonic stenosis(2 cases) and interventricular septal aneurysm(2 cases). The sensitivity of 2-D echo in detecting these anomalies was 65.5% and the specificity was 96.4%. 5) Among 32 patients who had postoperative complications, in two thirds, there were pulmonary complication including lung atelectasis(16 cases), pleural effusion(5 cases)and pneumonia(5 cases). 6) Operative mortality was 2.9%(4 cases). The causes of death were low cardiac output state due to left ventricular myocardial failure in 3 patients and respiratory failure from asphyxia in one case. In conclusion, with close cooperation with cardiac surgeons, there will be few problems in diagnosing and operating patients with ventricular septal defect on the basis of two-dimensional echocardiographic findings without invasive procedures, such as cardiac catheterization, even with pulmonary hypertension, unless Eisenmenger syndrome is complicated.
Asphyxia ; Blood Pressure ; Cardiac Catheterization ; Cardiac Catheters ; Cardiac Output, Low ; Catheterization* ; Catheters* ; Cause of Death ; Child* ; Echocardiography* ; Eisenmenger Complex ; Heart Failure ; Heart Septal Defects, Ventricular* ; Humans ; Hypertension, Pulmonary ; Lung ; Mortality ; Postoperative Complications ; Respiratory Insufficiency ; Sensitivity and Specificity