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

Gougerost-Blum syndrome is a rare disease and characterized by lichenoid papules in association with purpuric lesions. So far as we know there has been no report of, in literatures, Gougerot-Blum syndrome with leukemia. We experienced a case of typical Gougerrot_Blum syndrome with acute myeloblastic leukemia in a 30 year-old female patient. This patient complained of rashes on whole body for 2 months, and frequent epistaxis and gum bleeding for 20 days. The skin revealed miliary to rice sized rusty colored lichenoid papules on whole body especially on legs and arms. Histopathologically the skin showed the picture of Gougerot-Blum syndrome. On peripheral blood examination and bone marrow aspiration myeloblastic leukemia was confirmed. The patient was treated with 6-mercaptopurine, cytoxan and prednisolone with slight improvement of skin lesions, but no improvement of leukumia itselt.
6-Mercaptopurine ; Adult ; Arm ; Bone Marrow ; Cyclophosphamide ; Epistaxis ; Exanthema ; Female ; Gingiva ; Granulocyte Precursor Cells ; Hemorrhage ; Humans ; Leg ; Leukemia* ; Leukemia, Myeloid, Acute ; Prednisolone ; Rare Diseases ; Skin

We report a case of para.psoriasis variegata in a 19 year-old male patient wha has brownish flat scaly papules that are confluent in a retiform pattern characterized by symmetrical distribution on trunk and upper extremities. A skin biopsy specimen showed hyperkeratosis, focaI parakeratosis, hyperpigmentation of basal cell layer, and a mild lymphocytic perivascular infiltrate. No evidence was found for a relationship to lymphoma.
Biopsy ; Humans ; Hyperpigmentation ; Lymphoma ; Male ; Parakeratosis ; Parapsoriasis* ; Skin ; Upper Extremity ; Young Adult

Six patients with twenty histologically proven neurilemmomas of the extremities were studied using magnetic resonance(MR) imaging. The size, number, signal intensity on spin-echo T1WI(TR 500-650ms/TE 14-25ms)and gradient -echo (TR 200-600ms/TE 14-20ms; flip angle 25-30)image, enhancement pattern, detectability of nerve of origin, nerve-lesion relationship, and presence of a capsule were analyzed. The masses ranged from 1 to 12cm in longitudinal diameter and originated from the median nerve, ulnar nerve, sciatic nerve, radial nerve, and tibial nerve. All the nerve tracts except for those of 5 lesions, which could not be detected due to their small diameter, were visualized as low intensity tubular structures. All visible nerve tracts were situated along the periphery of the lesion and this finding was considered to be specific for neurilemmona. All neurilemmomas were isointense with the surrounding muscle on spin-echo T1WI and hyperintense on gradient-echo image. After a GD-DTPA injection, all masses showed moderate or marked enhancement and more prominent inhomogeneity than that on nonenhanced scan. In 19 out of 20 lesions(95%), a low signal intensity capsule surrounding the masses could be seen. Four of the six patients showed multiple masses, which was unusual as neurilemmoma usually arises as a solitary mass. In conclusion, the MR findings, especially the eccentric location of the mass lesion from the nerve of origin and the presence of a capsule, were useful in making a diagnosis of neurilemmoma of the extremity and that multiple neurilemmomas were not uncommon.
Diagnosis ; Extremities* ; Gadolinium DTPA ; Humans ; Median Nerve ; Neurilemmoma* ; Radial Nerve ; Sciatic Nerve ; Tibial Nerve ; Ulnar Nerve

No abstract available.
Female ; Humans ; Insulin* ; Intercellular Signaling Peptides and Proteins*

No abstract available.
Spinal Cord Diseases* ; Spinal Cord*

No abstract available.
Ichthyosiform Erythroderma, Congenital*

No abstract available.

No abstract available.
Blood Donors* ; HIV* ; Humans ; Mass Screening*

No abstract available.