Adeno-associated viral vector-mediated gene transfer of human blood coagulation factor IX into mouse liver

Recombinant adeno-associated virus vectors (AAV) were prepared in high titer (10(12) to 10(13) particles/mL) for the expression of human factor IX after in vivo transduction of murine hepatocytes. Injection of AAV-CMV-F.IX (expression from the human cytomegalovirus IE enhancer/promoter) into the portal vein of adult mice resulted in no detectable human factor IX in plasma, but in mice injected intravenously as newborns with the same vector, expression was initially 55 to 110 ng/mL. The expression in the liver was mostly transient, and plasma levels decreased to undetectable levels within 5 weeks. However, long-term expression of human F.IX was detected by immunofluorescence staining in 0.25% of hepatocytes 8 to 10 months postinjection. The loss of expression was likely caused by suppression of the CMV promoter, because polymerase chain reaction data showed no substantial loss of vector DNA in mouse liver. A second vector in which F.IX expression was controlled by the human EF1alpha promoter was constructed and injected into the portal vein of adult C57BL/6 mice at a dose of 6.3 x 10(10) particles. This resulted in therapeutic plasma levels (200 to 320 ng/mL) for a period of at least 6 months, whereas no human F.IX was detected in plasma of mice injected with AAV-CMV-F.IX. Doses of AAV-EF1alpha-F. IX of 2.7 x 10(11) particles resulted in plasma levels of 700 to 3, 200 ng/mL. Liver-derived expression of human F.IX from the AAV-EF1alpha-F.IX vector was confirmed by immunofluorescence staining. We conclude that recombinant AAV can efficiently transduce hepatocytes and direct stable expression of an F.IX transgene in mouse liver, but sustained expression is critically dependent on the choice of promoter.     

Patient attitudes toward rooming with persons with HIV infection

BACKGROUND: Early in the HIV epidemic, hospitals developed strict isolation policies for patients with HIV infection, some of which have not been revised. The objectives of this study were to examine patient attitudes about rooming with persons with various medical conditions, including HIV, and to assess their knowledge about the transmission of HIV. METHODS: One hundred four inpatients at a university hospital were surveyed by means of a structured interviewer-administered questionnaire. Patients were asked about preference for a single or double room, and about their objections to rooming with patients with HIV infection and other medical conditions. The questionnaire also examined subject's knowledge about the transmission of HIV. RESULTS: Of 104 inpatients surveyed, 55% objected to rooming with an HIV-seropositive patient. Patients who objected to rooming with an HIV-seropositive patient were also more likely to object to rooming with a disfigured patient (relative risk = 1.5; 95% CI, 1.1 to 2.2), or with a demented patient (relative risk = 1.7; 95% CI, 1.0 to 2.9). Also, patients who objected to rooming with an HIV-seropositive patient had greater misconceptions about the transmissibility of HIV infection. CONCLUSIONS: A significant proportion of patients reported an unwillingness to room with patients with HIV infection, but also had misconceptions about the transmissibility of HIV. Current rooming policies may perpetuate misconceptions about the possibility of causal transmission of HIV.     

Regulation of peripheral vascular tone in patients with heart failure: contribution of angiotensin II

This study evaluated the effects of stimulus repetition rate, phase, and frequency on the auditory brainstem response (ABR) in normal-hearing neonates and adults. In both neonates and adults, the results clearly showed large ABR wave V latency differences between condensation and rarefaction for low-frequency stimuli. Phase dependent latency effects are believed to be a result of the phase-sensitive low-frequency neurons. Increasing stimulus repetition rate produced greater wave V latency shift in neonates than in adults. The consequences of rate changes were independent of stimulus phase and frequency.