Pre-stimulation of CD81 expression by resting B cells increases proliferation following EBV infection, but the overexpression of CD81 induces the apoptosis of EBV-transformed B cells.

Hepatitis C virus (HCV) E2 protein binds to CD81, which is a component of the B cell co-stimulatory complex. The E2-CD81 interaction leads to B cell proliferation, protein tyrosine phosphorylation and to the hypermutation of immunoglobulin genes. Epidemiological studies have reported a high prevalence of B cell non-Hodgkin lymphoma (NHL) in HCV-positive patients, suggesting a potential association between HCV and Epstein-Barr virus (EBV) in the genesis of B lymphocyte proliferative disorders. In the present study, in order to investigate the association between EBV and HCV in B cells, we created an in vitro EBV-induced B cell transformation model. CD81 was gradually overexpressed during transformation by EBV. B cells isolated from HCV-positive patients grew more rapidly and clumped together earlier than B cells isolated from healthy donors following EBV infection. Pre-stimulation of CD81 expressed by resting B cells with anti-CD81 monoclonal antibody (mAb) or HCV E2 accelerated the generation of lymphoblastoid cell lines (LCLs) by EBV infection. These cells proliferated prominently through the early expression of interleukin-10 and intracellular latent membrane protein (LMP)-l. By contrast, the overexpression of CD81 on EBV-transformed B cells by anti-CD81 mAb or HCV E2 protein induced apoptosis through reactive oxygen species (ROS)-mediated mitochondrial dysfunction. These results suggest that the engagement of CD81 expressed by B cells has differential effects on B cell fate (proliferation or apoptosis) according to EBV infection and the expression level of CD81.

An efficient microvascular anastomosis training model based on chicken wings and simple instruments.

OBJECTIVE: The aim of this study is to introduce a microvascular training model based on use of materials that can be easily obtained from the daily surroundings. METHODS: Simple microinstruments and a medical school laboratory microscope were used for anastomosis training. Chicken blood vessels were used as a material for this study. A long segment of blood vessel from the proximal brachial artery to the distal radial artery was used for training. End-to-side anastomosis was practiced first, and the training continued with end-to-end anastomosis of the appropriate segments. RESULTS: The instruments used for setting up this model were simple and easy to use; therefore, the time required for preparation of the materials and dissection of the chicken wings was only approximately five to ten minutes. The characteristics of 20 chicken wings were analyzed. The length of the brachial artery to the radial artery was 8 - 10 cm. The average diameter of the brachial artery was 1.3 mm ± 0.2 mm and that of the radial artery was 1.0 mm ± 0.2 mm. Taking advantage of these characteristics, the proximal brachial artery was grafted to the radial artery for practice of end-to-side anastomosis. CONCLUSIONS: This study suggests an effective and feasible method for microvascular anastomosis training using chicken wing arteries and simple microinstruments. This model may simulate the conditions of a superficial temporal artery to middle cerebral artery anastomosis surgery.

Gamma Knife surgery for invasive pituitary macroadenoma.

OBJECT: Pituitary adenomas have been treated using a variety of modalities including resection, medication, fractionated radiotherapy, and stereotactic radiosurgery. The policy has been that all adenomas should first be treated with resection to reduce the volume of the tumor. The authors' study was conducted to determine the efficacy of using Gamma Knife surgery (GKS) for pituitary adenomas invading the cavernous sinus. METHODS: Of 397 patients with pituitary tumors who underwent GKS between October 1994 and October 2005, 68 patients had pituitary macroadenomas invading the cavernous sinus. Sixty-seven cases were available for follow up. The mean age of the patients in these cases was 42.8 years (range 14-73 years). The male/female ratio was 0.8:1. The mean adenoma volume was 9.3 cm3. A total of 24 patients had undergone craniotomies and resection, and 11 patients had undergone transsphenoidal surgery prior to GKS. The mean follow-up period was 32.8 months. Tumor control was defined as a decrease or no change in tumor volume after GKS. Endocrinological improvement was defined as a decline in hormone levels to below 50% of the pre-GKS level. Tumor control was achieved in 95.5% of the cases. Endocrinological improvement was achieved in 68% of 25 patients. One patient suffered hypopituitarism after GKS. CONCLUSIONS: Gamma Knife surgery is a safe and effective treatment for invasive pituitary macroadenoma with few complications.