Gene Therapy in Rats with a Lentiviral Vector Containing the Human Coagulation Factor IX Gene / 대한수혈학회지

BACKGROUND: Hemophilia B is an inheritable X-linked bleeding disorder that occurs as a consequence of genetic alterations within the factor IX (IX) gene. In the present study, pseudotyped HIV-I-derived lentiviral vectors expressing human IX (lentivirus-IX) were assessed for the ability to produce an active human IX in the animals transduced with lentivirus-IX. METHODS: The IX concentrations and activated partial thromboplastin times (aPTT) were measured from the supernatants of HeLa cells that were transduced with lentivirus-IX. In an animal study, we injected 1microgram of lentivirus-IX into the hind limbs of Sparague-Dawley (SD) rats. The IX concentrations were measured from the plasma of the vehicle injected rats and the plasma of the lentivirus-IX injected rats for 8 weeks. RESULTS: The in vitro expression of human IX was detected in a dose-dependent manner following the transduction of lentivirus-IX into the HeLa cells (control: 10+/-3 vs. 100 ng of lentivirus-IX: 1486+/-50 ng/mL, P<0.05). The aPTT also showed the tendency of dose-dependent decrease (control: 83.9+/-0.5 vs. 50 ng of lentivirus-IX: 80.1+/- 0.8 sec), but this was not statistically significant. In the animal experiment, the plasma IX concentration from the lentivirus-IX transduced rats (n=3) was significantly increased compared to the vehicle-injected rats (n=4) (5.9+/-3.9 vs. 46.4+/-20.6 ng/mL) at post-injection 1 week. CONCLUSION: This study demonstrated that in vivo delivery of lentiviral vectors expressing human IX to the muscle cells has the potential to be a therapeutic modality for hemophilia B.

Contamination of Acanthamoeba in Contact Lens Care System

Recently, the number of reports of Acanthamoeba keratitis has been increased apparently as a consequence of association with use of contact lenses, contaminated contact lens care system and high concern of ophthalmologist to Acanthamoeba keratitis. But, there were few epidemiologic studies of contamination of contact lens care system by Acanthamoeba and there was no report in Korea. We carried out a survey to demonstrate the contamination of contact lens care system by Acanthamoeba and bacteria and analysed the results according to the types of contact lenses and methods of disinfection. We examined the contact lens care system of 185 asymptomatic contact lens wearer for the contamination of Acanthamoeba and bacteria. The result showed a significant contamination of Acanthamoeba and bacteria. Twenty eight(15%) were contaminated with Acanthamoeba, eighteen(10%) were mixed with bacterial contamination and seventy four(40%) were contaminated with bacteria. There was no significant difference with sex and the result showed a lot of cocontamination with bacteria and amoeba and chemical disinfection showed a high Acanthamoeba contamination rate. Based on data from this and previous studies, the most of contact lens care system of contact lens wearer was contaminated with bacteria, amoeba and other microorganism. So, ophthalmologists should be concerned about Acanthamoeba contamination of contact lens care system.

Two Cases of Endogenous Endophthalmitis

Bacterial endophthalmitis remains an uncommon, but devastating complication of ocular surgery, trauma, and systemic infection. Most cases develop from an exegenous source and are introduced at the time of ocular surgery or penetrating trauma to the eye. Hematogenous spread of bacterial infection to the eye may also result in bacterial endophthalmitis. But, endogenous endophthalmitis caused by gram-negative bacteria in debilitated or immunocompromised patients and drug abusers has become well recognized in recent years. We report cases of endogenous Klebsiella pneumoniae endophthalmitis associatied with sepsis in a poor controlled diabetic patient and Streptocpccus pyogenes endophthalamitis associated with transurethral laser-induced prostatectomy of benign prostatic hypertrophy in a pneumonia patient.

Clinical Results of the Q-Switched Nd-YAG Laser Iridotomy

In order to evaluate the effect of Q-switched YAG laser iridotomy to the intraocular pressure, we performed the Q-switched Nd-YAG laser iridotomy in 39 eyes of 28 patients with angle closure glaucoma. Postoperative difference of the intraocular pressure was 27.5 +/- 27.0mmHg and the intraocular pressure was reduced. After 2 months, 12 eyes had needed one kind of anti-glaucomatous medication, 7 eyes had needed no medication, 6 eyes had needed two medications and 1 eye had needed three medications. Postoperative complications were iris bleeding(10 eyes), transient pressure rising(9 eyes), focal corneal opacities(2 eyes) and closure of iridotomy(2 eyes). These result shows that laser iridotomy should be considered in the management of angle closure glaucoma.